@article{ConzenAlbannaWeissetal.2018,
  author    = {Conzen, Catharina and Albanna, Walid and Weiss, Miriam and K{\"u}rten, David and Vilser, Walthard and Kotliar, Konstantin and Z{\"a}ske, Charlotte and Clusmann, Hans and Schubert, Gerrit Alexander},
  title     = {Vasoconstriction and Impairment of Neurovascular Coupling after Subarachnoid Hemorrhage: a Descriptive Analysis of Retinal Changes},
  series = {Translational Stroke Research},
  journal   = {Translational Stroke Research},
  number    = {9},
  publisher = {Springer Nature},
  address   = {Cham},
  issn      = {1868-601X},
  doi       = {10.1007/s12975-017-0585-8},
  pages     = {284 -- 293},
  year      = {2018},
  abstract  = {Impaired cerebral autoregulation and neurovascular coupling (NVC) contribute to delayed cerebral ischemia after subarachnoid hemorrhage (SAH). Retinal vessel analysis (RVA) allows non-invasive assessment of vessel dimension and NVC hereby demonstrating a predictive value in the context of various neurovascular diseases. Using RVA as a translational approach, we aimed to assess the retinal vessels in patients with SAH. RVA was performed prospectively in 24 patients with acute SAH (group A: day 5-14), in 11 patients 3 months after ictus (group B: day 90 ± 35), and in 35 age-matched healthy controls (group C). Data was acquired using a Retinal Vessel Analyzer (Imedos Systems UG, Jena) for examination of retinal vessel dimension and NVC using flicker-light excitation. Diameter of retinal vessels—central retinal arteriolar and venular equivalent—was significantly reduced in the acute phase (p < 0.001) with gradual improvement in group B (p < 0.05). Arterial NVC of group A was significantly impaired with diminished dilatation (p < 0.001) and reduced area under the curve (p < 0.01) when compared to group C. Group B showed persistent prolonged latency of arterial dilation (p < 0.05). Venous NVC was significantly delayed after SAH compared to group C (A p < 0.001; B p < 0.05). To our knowledge, this is the first clinical study to document retinal vasoconstriction and impairment of NVC in patients with SAH. Using non-invasive RVA as a translational approach, characteristic patterns of compromise were detected for the arterial and venous compartment of the neurovascular unit in a time-dependent fashion. Recruitment will continue to facilitate a correlation analysis with clinical course and outcome.},
  language  = {en}
}
@inproceedings{IomdinaKiselevaKotliaretal.2020,
  author    = {Iomdina, Elena N. and Kiseleva, Anna A. and Kotliar, Konstantin and Luzhnov, Petr V.},
  title     = {Quantification of Choroidal Blood Flow Using the OCT-A System Based on Voxel Scan Processing},
  series = {2020 International Conference on Biomedical Innovations and Applications (BIA)},
  booktitle = {2020 International Conference on Biomedical Innovations and Applications (BIA)},
  isbn      = {978-1-7281-7073-2},
  doi       = {10.1109/BIA50171.2020.9244511},
  pages     = {41 -- 44},
  year      = {2020},
  language  = {en}
}
@article{NeumaierWeissVeldemanetal.2021,
  author    = {Neumaier, Felix and Weiss, Miriam and Veldeman, Michael and Kotliar, Konstantin and Wiesmann, Martin and Schulze-Steinen, Henna and H{\"o}llig, Anke and Clusmann, Hans and Schubert, Gerrit Alexander and Albanna, Walid},
  title     = {Changes in endogenous daytime melatonin levels after aneurysmal subarachnoid hemorrhage - preliminary findings from an observational cohort study},
  series = {Clinical Neurology and Neurosurgery},
  volume    = {208},
  journal   = {Clinical Neurology and Neurosurgery},
  number    = {Article No.: 106870},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0303-8467},
  doi       = {10.1016/j.clineuro.2021.106870},
  year      = {2021},
  abstract  = {Aneurysmal subarachnoid hemorrhage (aSAH) is associated with early and delayed brain injury due to several underlying and interrelated processes, which include inflammation, oxidative stress, endothelial, and neuronal apoptosis. Treatment with melatonin, a cytoprotective neurohormone with anti-inflammatory, anti-oxidant and anti-apoptotic effects, has been shown to attenuate early brain injury (EBI) and to prevent delayed cerebral vasospasm in experimental aSAH models. Less is known about the role of endogenous melatonin for aSAH outcome and how its production is altered by the pathophysiological cascades initiated during EBI. In the present observational study, we analyzed changes in melatonin levels during the first three weeks after aSAH.},
  language  = {en}
}
@article{KotliarOrtnerConradietal.2022,
  author    = {Kotliar, Konstantin and Ortner, Marion and Conradi, Anna and Hacker, Patricia and Hauser, Christine and G{\"u}nthner, Roman and Moser, Michaela and Muggenthaler, Claudia and Diehl-Schmid, Janine and Priller, Josef and Schmaderer, Christoph and Grimmer, Timo},
  title     = {Altered retinal cerebral vessel oscillation frequencies in Alzheimer's disease compatible with impaired amyloid clearance},
  series = {Neurobiology of Aging},
  volume    = {120},
  journal   = {Neurobiology of Aging},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0197-4580},
  doi       = {10.1016/j.neurobiolaging.2022.08.012},
  pages     = {117 -- 127},
  year      = {2022},
  abstract  = {Retinal vessels are similar to cerebral vessels in their structure and function. Moderately low oscillation frequencies of around 0.1 Hz have been reported as the driving force for paravascular drainage in gray matter in mice and are known as the frequencies of lymphatic vessels in humans. We aimed to elucidate whether retinal vessel oscillations are altered in Alzheimer's disease (AD) at the stage of dementia or mild cognitive impairment (MCI). Seventeen patients with mild-to-moderate dementia due to AD (ADD); 23 patients with MCI due to AD, and 18 cognitively healthy controls (HC) were examined using Dynamic Retinal Vessel Analyzer. Oscillatory temporal changes of retinal vessel diameters were evaluated using mathematical signal analysis. Especially at moderately low frequencies around 0.1 Hz, arterial oscillations in ADD and MCI significantly prevailed over HC oscillations and correlated with disease severity. The pronounced retinal arterial vasomotion at moderately low frequencies in the ADD and MCI groups would be compatible with the view of a compensatory upregulation of paravascular drainage in AD and strengthen the amyloid clearance hypothesis.},
  language  = {en}
}
@article{AttarMerkKotliaretal.2019,
  author    = {Attar, Mandana Hossein Zadeh and Merk, Hans F. and Kotliar, Konstantin and Wurpts, Gerda and R{\"o}seler, Stefani and Moll-Slodowy, Silke and Plange, Johann and Baron, Jens Malte and Balakirski, Galina},
  title     = {The CD63 basophil activation test as a diagnostic tool for assessing autoimmunity in patients with chronic spontaneous urticaria},
  series = {European Journal of Dermatology},
  volume    = {29},
  journal   = {European Journal of Dermatology},
  number    = {6},
  doi       = {10.1684/ejd.2019.3680},
  pages     = {614 -- 618},
  year      = {2019},
  language  = {en}
}
@article{SmithKotliarLammertynetal.2020,
  author    = {Smith, Wayne and Kotliar, Konstantin and Lammertyn, Leandi and Ramoshaba, Nthai E. and Vilser, Walthard and Huisman, Hugo W. and Schutte, Aletta E.},
  title     = {Retinal vessel caliber and caliber responses in true normotensive black and white adults: The African-PREDICT study},
  series = {Microvascular Research},
  volume    = {128},
  journal   = {Microvascular Research},
  number    = {Article 103937},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0026-2862},
  doi       = {10.1016/j.mvr.2019.103937},
  year      = {2020},
  abstract  = {Purpose Globally, a detrimental shift in cardiovascular disease risk factors and a higher mortality level are reported in some black populations. The retinal microvasculature provides early insight into the pathogenesis of systemic vascular diseases, but it is unclear whether retinal vessel calibers and acute retinal vessel functional responses differ between young healthy black and white adults. Methods We included 112 black and 143 white healthy normotensive adults (20-30 years). Retinal vessel calibers (central retinal artery and vein equivalent (CRAE and CRVE)) were calculated from retinal images and vessel caliber responses to flicker light induced provocation (FLIP) were determined. Additionally, ambulatory blood pressure (BP), anthropometry and blood samples were collected. Results The groups displayed similar 24 h BP profiles and anthropometry (all p > .24). Black participants demonstrated a smaller CRAE (158 ± 11 vs. 164 ± 11 MU, p < .001) compared to the white group, whereas CRVE was similar (p = .57). In response to FLIP, artery maximal dilation was greater in the black vs. white group (5.6 ± 2.1 vs. 3.3 ± 1.8\%; p < .001). Conclusions Already at a young age, healthy black adults showed narrower retinal arteries relative to the white population. Follow-up studies are underway to show if this will be related to increased risk for hypertension development. The reason for the larger vessel dilation responses to FLIP in the black population is unclear and warrants further investigation.},
  language  = {en}
}
@article{StreeseKotliarDeiserothetal.2020,
  author    = {Streese, Lukas and Kotliar, Konstantin and Deiseroth, Arne and Infanger, Denis and Gugleta, Konstantin and Schmaderer, Christoph and Hanssen, Henner},
  title     = {Retinal endothelial function in cardiovascular risk patients: A randomized controlled exercise trial},
  series = {Scandinavian Journal of Medicine and Science in Sports},
  volume    = {30},
  journal   = {Scandinavian Journal of Medicine and Science in Sports},
  number    = {2},
  publisher = {Wiley},
  address   = {Oxford},
  issn      = {1600-0838},
  doi       = {10.1111/sms.13560},
  pages     = {272 -- 280},
  year      = {2020},
  abstract  = {The aim of this study was to investigate, for the first time, the effects of high-intensity interval training (HIIT) on retinal microvascular endothelial function in cardiovascular (CV) risk patients. In the randomized controlled trial, middle-aged and previously sedentary patients with increased CV risk (aged 58 ± 6 years) with ≥ two CV risk factors were randomized into a 12-week HIIT (n = 33) or control group (CG, n = 36) with standard physical activity recommendations. A blinded examiner measured retinal endothelial function by flicker light-induced maximal arteriolar (ADmax) and venular (VDmax) dilatation as well as the area under the arteriolar (AFarea) and venular (VFarea) flicker curve using a retinal vessel analyzer. Standardized assessments of CV risk factors, cardiorespiratory fitness, and retinal endothelial function were performed before and after HIIT. HIIT reduced body mass index, fat mass, and low-density lipoprotein and increased muscle mass and peak oxygen uptake (VO2peak). Both ADmax (pre: 2.7 ± 2.1\%, post: 3.0 ± 2.2\%, P = .018) and AFarea (pre: 32.6 ± 28.4\%*s, post: 37.7 ± 30.6\%*s, P = .016) increased after HIIT compared with CG (ADmax, pre: 3.2 ± 1.8\%, post: 2.9 ± 1.8\%, P = .254; AFarea, pre: 41.6 ± 28.5\%*s, post: 37.8 ± 27.0\%*s, P = .186). Venular function remained unchanged after HIIT. There was a significant association between ∆-change VO2peak and ∆-changes ADmax and AFarea (P = .026, R² = 0.073; P = .019, R² = 0.081, respectively). 12-weeks of HIIT improved retinal endothelial function in middle-aged patients with increased CV risk independent of the reduction in classical CV risk factors. Exercise has the potential to reverse or at least postpone progression of small vessel disease in older adults with increased CV risk under standard medication. Dynamic retinal vessel analysis seems to be a sensitive tool to detect treatment effects of exercise interventions on retinal microvascular endothelial function in middle-aged individuals with increased CV risk.},
  language  = {en}
}
@article{HamouKotliarTanetal.2020,
  author    = {Hamou, Hussam Aldin and Kotliar, Konstantin and Tan, Sonny Kian and Weiß, Christel and Blume, Christian and Clusmann, Hans and Schubert, Gerrit Alexander and Albanna, Walid},
  title     = {Surgical nuances and placement of subgaleal drains for supratentorial procedures—a prospective analysis of efficacy and outcome in 150 craniotomies},
  series = {Acta Neurochirurgica},
  volume    = {2020},
  journal   = {Acta Neurochirurgica},
  number    = {162},
  publisher = {Springer Nature},
  address   = {Cham},
  issn      = {0942-0940},
  doi       = {10.1007/s00701-019-04196-6},
  pages     = {729 -- 736},
  year      = {2020},
  abstract  = {Background For supratentorial craniotomy, surgical access, and closure technique, including placement of subgaleal drains, may vary considerably. The influence of surgical nuances on postoperative complications such as cerebrospinal fluid leakage or impaired wound healing overall remains largely unclear. With this study, we are reporting our experiences and the impact of our clinical routines on outcome in a prospectively collected data set. Method We prospectively observed 150 consecutive patients undergoing supratentorial craniotomy and recorded technical variables (type/length of incision, size of craniotomy, technique of dural and skin closure, type of dressing, and placement of subgaleal drains). Outcome variables (subgaleal hematoma/CSF collection, periorbital edema, impairment of wound healing, infection, and need for operative revision) were recorded at time of discharge and at late follow-up. Results Early subgaleal fluid collection was observed in 36.7\% (2.8\% at the late follow-up), and impaired wound healing was recorded in 3.3\% of all cases, with an overall need for operative revision of 6.7\%. Neither usage of dural sealants, lack of watertight dural closure, and presence of subgaleal drains, nor type of skin closure or dressing influenced outcome. Curved incisions, larger craniotomy, and tumor size, however, were associated with an increase in early CSF or hematoma collection (p < 0.0001, p = 0.001, p < 0.01 resp.), and larger craniotomy size was associated with longer persistence of subgaleal fluid collections (p < 0.05). Conclusions Based on our setting, individual surgical nuances such as the type of dural closure and the use of subgaleal drains resulted in a comparable complication rate and outcome. Subgaleal fluid collections were frequently observed after supratentorial procedures, irrespective of the closing technique employed, and resolve spontaneously in the majority of cases without significant sequelae. Our results are limited due to the observational nature in our single-center study and need to be validated by supportive prospective randomized design.},
  language  = {en}
}
@article{NeumaierKotliarHaerenetal.2021,
  author    = {Neumaier, Felix and Kotliar, Konstantin and Haeren, Roel Hubert Louis and Temel, Yasin and L{\"u}ke, Jan Niklas and Seyam, Osama and Lindauer, Ute and Clusmann, Hans and Hescheler, J{\"u}rgen and Schubert, Gerrit Alexander and Schneider, Toni and Albanna, Walid},
  title     = {Retinal Vessel Responses to Flicker Stimulation Are Impaired in Ca v 2.3-Deficient Mice—An in- vivo Evaluation Using Retinal Vessel Analysis (RVA)},
  series = {Frontiers in Neurology},
  volume    = {12},
  journal   = {Frontiers in Neurology},
  publisher = {Frontiers},
  doi       = {10.3389/fneur.2021.659890},
  pages     = {1 -- 11},
  year      = {2021},
  language  = {en}
}
@article{AngermannGuenthnerHanssenetal.2022,
  author    = {Angermann, Susanne and G{\"u}nthner, Roman and Hanssen, Henner and Lorenz, Georg and Braunisch, Matthias C. and Steubl, Dominik and Matschkal, Julia and Kemmner, Stephan and Hausinger, Renate and Block, Zenonas and Haller, Bernhard and Heemann, Uwe and Kotliar, Konstantin and Grimmer, Timo and Schmaderer, Christoph},
  title     = {Cognitive impairment and microvascular function in end-stage renal disease},
  series = {International Journal of Methods in Psychiatric Research (MPR)},
  volume    = {31},
  journal   = {International Journal of Methods in Psychiatric Research (MPR)},
  number    = {2},
  publisher = {Wiley},
  issn      = {1049-8931 (Print)},
  doi       = {10.1002/mpr.1909},
  pages     = {1 -- 10},
  year      = {2022},
  abstract  = {Objective Hemodialysis patients show an approximately threefold higher prevalence of cognitive impairment compared to the age-matched general population. Impaired microcirculatory function is one of the assumed causes. Dynamic retinal vessel analysis is a quantitative method for measuring neurovascular coupling and microvascular endothelial function. We hypothesize that cognitive impairment is associated with altered microcirculation of retinal vessels. Methods 152 chronic hemodialysis patients underwent cognitive testing using the Montreal Cognitive Assessment. Retinal microcirculation was assessed by Dynamic Retinal Vessel Analysis, which carries out an examination recording retinal vessels' reaction to a flicker light stimulus under standardized conditions. Results In unadjusted as well as in adjusted linear regression analyses a significant association between the visuospatial executive function domain score of the Montreal Cognitive Assessment and the maximum arteriolar dilation as response of retinal arterioles to the flicker light stimulation was obtained. Conclusion This is the first study determining retinal microvascular function as surrogate for cerebral microvascular function and cognition in hemodialysis patients. The relationship between impairment in executive function and reduced arteriolar reaction to flicker light stimulation supports the involvement of cerebral small vessel disease as contributing factor for the development of cognitive impairment in this patient population and might be a target for noninvasive disease monitoring and therapeutic intervention.},
  language  = {en}
}
@article{KuchlerGuenthnerRibeiroetal.2023,
  author    = {Kuchler, Timon and G{\"u}nthner, Roman and Ribeiro, Andrea and Hausinger, Renate and Streese, Lukas and W{\"o}hnl, Anna and Kesseler, Veronika and Negele, Johanna and Assali, Tarek and Carbajo-Lozoya, Javier and Lech, Maciej and Adorjan, Kristina and Stubbe, Hans Christian and Hanssen, Henner and Kotliar, Konstantin and Haller, Berhard and Heemann, Uwe and Schmaderer, Christoph},
  title     = {Persistent endothelial dysfunction in post-COVID-19 syndrome and its associations with symptom severity and chronic inflammation},
  volume    = {26},
  publisher = {Springer Nature},
  address   = {Dordrecht},
  doi       = {10.1007/s10456-023-09885-6},
  pages     = {547 -- 563},
  year      = {2023},
  abstract  = {Background Post-COVID-19 syndrome (PCS) is a lingering disease with ongoing symptoms such as fatigue and cognitive impairment resulting in a high impact on the daily life of patients. Understanding the pathophysiology of PCS is a public health priority, as it still poses a diagnostic and treatment challenge for physicians. Methods In this prospective observational cohort study, we analyzed the retinal microcirculation using Retinal Vessel Analysis (RVA) in a cohort of patients with PCS and compared it to an age- and gender-matched healthy cohort (n = 41, matched out of n = 204). Measurements and main results PCS patients exhibit persistent endothelial dysfunction (ED), as indicated by significantly lower venular flicker-induced dilation (vFID; 3.42\% ± 1.77\% vs. 4.64\% ± 2.59\%; p = 0.02), narrower central retinal artery equivalent (CRAE; 178.1 [167.5-190.2] vs. 189.1 [179.4-197.2], p = 0.01) and lower arteriolar-venular ratio (AVR; (0.84 [0.8-0.9] vs. 0.88 [0.8-0.9], p = 0.007). When combining AVR and vFID, predicted scores reached good ability to discriminate groups (area under the curve: 0.75). Higher PCS severity scores correlated with lower AVR (R = - 0.37 p = 0.017). The association of microvascular changes with PCS severity were amplified in PCS patients exhibiting higher levels of inflammatory parameters. Conclusion Our results demonstrate that prolonged endothelial dysfunction is a hallmark of PCS, and impairments of the microcirculation seem to explain ongoing symptoms in patients. As potential therapies for PCS emerge, RVA parameters may become relevant as clinical biomarkers for diagnosis and therapy management.},
  language  = {en}
}
@article{AlbannaKotliarLuekeetal.2018,
  author    = {Albanna, Walid and Kotliar, Konstantin and L{\"u}ke, Jan Niklas and Alpdogan, Serdar and Conzen, Catharina and Lindauer, Ute and Clusmann, Hans and Hescheler, J{\"u}rgen and Vilser, Walthard and Schneider, Toni and Schubert, Gerrit Alexander},
  title     = {Non-invasive evaluation of neurovascular coupling in the murine retina by dynamic retinal vessel analysis},
  series = {Plos one},
  volume    = {13},
  journal   = {Plos one},
  number    = {10},
  publisher = {PLOS},
  address   = {San Francisco},
  doi       = {10.1371/journal.pone.0204689},
  pages     = {e0204689},
  year      = {2018},
  abstract  = {Background Impairment of neurovascular coupling (NVC) was recently reported in the context of subarachnoid hemorrhage and may correlate with disease severity and outcome. However, previous techniques to evaluate NVC required invasive procedures. Retinal vessels may represent an alternative option for non-invasive assessment of NVC. Methods A prototype of an adapted retinal vessel analyzer was used to assess retinal vessel diameter in mice. Dynamic vessel analysis (DVA) included an application of monochromatic flicker light impulses in predefined frequencies for evaluating NVC. All retinae were harvested after DVA and electroretinograms were performed. Results A total of 104 retinal scans were conducted in 21 male mice (90 scans). Quantitative arterial recordings were feasible only in a minority of animals, showing an emphasized reaction to flicker light impulses (8 mice; 14 scans). A characteristic venous response to flicker light, however, could observed in the majority of animals. Repeated measurements resulted in a significant decrease of baseline venous diameter (7 mice; 7 scans, p < 0.05). Ex-vivo electroretinograms, performed after in-vivo DVA, demonstrated a significant reduction of transretinal signaling in animals with repeated DVA (n = 6, p < 0.001). Conclusions To the best of our knowledge, this is the first non-invasive study assessing murine retinal vessel response to flicker light with characteristic changes in NVC. The imaging system can be used for basic research and enables the investigation of retinal vessel dimension and function in control mice and genetically modified animals.},
  language  = {en}
}
@article{AlbannaConzenWeissetal.2016,
  author    = {Albanna, W. and Conzen, C. and Weiss, M. and Clusmann, H. and Fuest, M. and Mueller, M. and Brockmann, M.A. and Vilser, W. and Schmidt-Trucks{\"a}ss, A. and Hoellig, A. and Seiz, M. and Thom{\´e}, C. and Kotliar, Konstantin and Schubert, G.A.},
  title     = {Retinal Vessel Analysis (RVA) in the context of subarachnoid hemorrhage: A proof of concept study},
  series = {PLoS ONE},
  volume    = {11},
  journal   = {PLoS ONE},
  number    = {7},
  publisher = {PLOS},
  address   = {San Francisco},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0158781},
  pages     = {13 Seiten},
  year      = {2016},
  abstract  = {Background Timely detection of impending delayed cerebral ischemia after subarachnoid hemorrhage (SAH) is essential to improve outcome, but poses a diagnostic challenge. Retinal vessels as an embryological part of the intracranial vasculature are easily accessible for analysis and may hold the key to a new and non-invasive monitoring technique. This investigation aims to determine the feasibility of standardized retinal vessel analysis (RVA) in the context of SAH. Methods In a prospective pilot study, we performed RVA in six patients awake and cooperative with SAH in the acute phase (day 2-14) and eight patients at the time of follow-up (mean 4.6±1.7months after SAH), and included 33 age-matched healthy controls. Data was acquired using a manoeuvrable Dynamic Vessel Analyzer (Imedos Systems UG, Jena) for examination of retinal vessel dimension and neurovascular coupling. Results Image quality was satisfactory in the majority of cases (93.3\%). In the acute phase after SAH, retinal arteries were significantly dilated when compared to the control group (124.2±4.3MU vs 110.9±11.4MU, p<0.01), a difference that persisted to a lesser extent in the later stage of the disease (122.7±17.2MU, p<0.05). Testing for neurovascular coupling showed a trend towards impaired primary vasodilation and secondary vasoconstriction (p = 0.08, p = 0.09 resp.) initially and partial recovery at the time of follow-up, indicating a relative improvement in a time-dependent fashion. Conclusion RVA is technically feasible in patients with SAH and can detect fluctuations in vessel diameter and autoregulation even in less severely affected patients. Preliminary data suggests potential for RVA as a new and non-invasive tool for advanced SAH monitoring, but clinical relevance and prognostic value will have to be determined in a larger cohort.},
  language  = {en}
}
@article{GarhoferBekBoehmetal.2010,
  author    = {Garhofer, Gerhard and Bek, Toke and Boehm, Andreas G. and Gherghel, Doina and Grundwald, Juan and Jeppesen, Peter and Kergoat, H{\´e}l{\`e}ne and Kotliar, Konstantin and Lanzl, Ines and Lovasik, John V. and Nagel, Edgar and Vilser, Walthard and Orgul, Selim and Schmetterer, Leopold},
  title     = {Use of the retinal vessel analyzer in ocular blood flow research},
  series = {Acta Ophthalmol},
  volume    = {88},
  journal   = {Acta Ophthalmol},
  number    = {7},
  publisher = {Wiley-Blackwell},
  address   = {Oxford},
  issn      = {1755-3768},
  doi       = {10.1111/j.1755-3768.2009.01587.x},
  pages     = {717 -- 722},
  year      = {2010},
  abstract  = {The present article describes a standard instrument for the continuous online determination of retinal vessel diameters, the commercially available retinal vessel analyzer. This report is intended to provide informed guidelines for measuring ocular blood flow with this system. The report describes the principles underlying the method and the instruments currently available, and discusses clinical protocol and the specific parameters measured by the system. Unresolved questions and the possible limitations of the technique are also discussed.},
  language  = {en}
}
@article{PresslerEsefeldScherretal.2010,
  author    = {Pressler, Axel and Esefeld, Katrin and Scherr, Johannes and Ali, Mohammad and Hanssen, Henner and Kotliar, Konstantin and Lanzl, Ines and Halle, Martin and Kaemmerer, Harald and Schmidt-Trucks{\"a}ss, Arno and Hager, Alfred},
  title     = {Structural alterations of retinal arterioles in adults late after repair of aortic isthmic coarctation},
  series = {The American Journal of Cardiology},
  volume    = {105},
  journal   = {The American Journal of Cardiology},
  number    = {5},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0002-9149},
  doi       = {10.1016/j.amjcard.2009.10.070},
  pages     = {740 -- 744},
  year      = {2010},
  abstract  = {Patients after coarctation repair still have an increased risk of cardiovascular or cerebrovascular events. This has been explained by the persisting hypertension and alterations in the peripheral vessels. However, involvement of the central vessels such as the retinal arteries is virtually unknown. A total of 34 patients after coarctation repair (22 men and 12 women; 23 to 58 years old, age range 0 to 32 years at surgical repair) and 34 nonhypertensive controls underwent structural and functional retinal vessel analysis. Using structural analysis, the vessel diameters were measured. Using functional analysis, the endothelium-dependent vessel dilation in response to flicker light stimulation was assessed. In the patients after coarctation repair, the retinal arteriolar diameter was significantly reduced compared to that of the controls (median 182 μm, first to third quartile 171 to 197; vs 197 μm, first to third quartile 193 to 206; p <0.001). These findings were independent of the peripheral blood pressure and age at intervention. No differences were found for venules. The functional analysis findings were not different between the patients and controls (maximum dilation 3.5\%, first to third quartile 2.1\% to 4.5\% vs 3.6\%, first to third quartile 2.2\% to 4.3\%; p = 0.81), indicating preserved autoregulative mechanisms. In conclusion, the retinal artery diameter is reduced in patients after coarctation repair, independent of their current blood pressure level and age at intervention. As a structural marker of chronic vessel damage associated with past, current, or future hypertension, retinal arteriolar narrowing has been linked to stroke incidence. These results indicate an involvement of cerebral microcirculation in aortic coarctation, despite timely repair, and might contribute to explain the increased rate of cerebrovascular events in such patients.},
  language  = {en}
}
@article{KotliarNagelVilseretal.2010,
  author    = {Kotliar, Konstantin and Nagel, Edgar and Vilser, Walthard and Seidova, Seid-Fatima and Lanzl, Ines},
  title     = {Microstructural alterations of retinal arterial blood column along the vessel axis in systemic hypertension},
  series = {Investigative Ophthalmology \& Visual Science, IOVS},
  volume    = {51},
  journal   = {Investigative Ophthalmology \& Visual Science, IOVS},
  number    = {4},
  publisher = {ARVO},
  address   = {Rockville, Md.},
  issn      = {0146-0404},
  doi       = {10.1167/iovs.09-3649},
  pages     = {2165 -- 2172},
  year      = {2010},
  abstract  = {Purpose: Image analysis by the retinal vessel analyzer (RVA) observes retinal vessels in their dynamic state online noninvasively along a chosen vessel segment. It has been found that high-frequency diameter changes in the retinal artery blood column along the vessel increase significantly in anamnestically healthy volunteers with increasing age and in patients with glaucoma during vascular dilation. This study was undertaken to investigate whether longitudinal sections of the retinal artery blood column are altered in systemic hypertension. Methods: Retinal arteries of 15 untreated patients with essential arterial hypertension (age, 50.9 ± 11.9 years) and of 15 age-matched anamnestically healthy volunteers were examined by RVA. After baseline assessment, a monochromatic luminance flicker (530-600 nm; 12.5 Hz; 20 s) was applied to evoke retinal vasodilation. Differences in amplitude and frequency of spatial artery blood column diameter change along segments (longitudinal arterial profiles) of 1 mm in length were measured and analyzed using Fourier transformation. Results: In the control group, average reduced power spectra (ARPS) of longitudinal arterial profiles did not differ when arteries changed from constriction to dilation. In the systemic hypertension group, ARPS during constriction, baseline, and restoration were identical and differed from ARPS during dilation (P < 0.05). Longitudinal arterial profiles in both groups showed significant dissimilitude at baseline and restoration (P < 0.05). Conclusions: The retinal artery blood column demonstrates microstructural alterations in systemic hypertension and is less irregular along the vessel axis during vessel dilation. These microstructural changes may be an indication of alterations in vessel wall rigidity, vascular endothelial function, and smooth muscle cells in this disease, leading to impaired perfusion and regulation.},
  language  = {en}
}
@book{DigelZhubanovaAkimbekov2012,
  author    = {Digel, Ilya and Zhubanova, Azhar Ahmetovna and Akimbekov, Nuraly Shardarbekovich},
  title     = {Visual Virology},
  address   = {Almaty},
  isbn      = {978-601-247-298-1},
  pages     = {144 S. : zahlr. Ill.},
  year      = {2012},
  language  = {en}
}
@article{Digel2011,
  author    = {Digel, Ilya},
  title     = {Primary thermosensory events in cells},
  series = {Transient receptor potential channels / Md. Shahidul Islam, ed.},
  journal   = {Transient receptor potential channels / Md. Shahidul Islam, ed.},
  publisher = {Springer},
  address   = {Dordrecht [u.a.]},
  isbn      = {978-94-007-0264-6},
  pages     = {451 -- 468},
  year      = {2011},
  language  = {en}
}
@article{Digel2008,
  author    = {Digel, Ilya},
  title     = {Controlling microbial adhesion : a surface engineering approach},
  series = {Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.)},
  journal   = {Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.)},
  publisher = {Springer},
  address   = {Berlin [u.a.]},
  isbn      = {978-3-540-75408-4},
  pages     = {601 -- 625},
  year      = {2008},
  language  = {en}
}
@article{DigelKurulganDemirciLinderetal.2007,
  author    = {Digel, Ilya and Kurulgan Demirci, Eylem and Linder, Peter and Kayser, Peter},
  title     = {Decrease in extracellular collagen crosslinking after NMR magnetic field application in skin fibroblasts},
  series = {Medical and Biological Engineering and Computing. 45 (2007), H. 1},
  journal   = {Medical and Biological Engineering and Computing. 45 (2007), H. 1},
  isbn      = {1741-0444},
  pages     = {91 -- 97},
  year      = {2007},
  language  = {en}
}
@article{DigelMaggakisKelemenZerlinetal.2006,
  author    = {Digel, Ilya and Maggakis-Kelemen, Christina and Zerlin, Kay and Linder, Peter},
  title     = {Body temperature-related structural transitions of monotremal and human hemoglobin},
  series = {Biophysical Journal. 91 (2006), H. 8},
  journal   = {Biophysical Journal. 91 (2006), H. 8},
  isbn      = {1542-0086},
  pages     = {3014 -- 3021},
  year      = {2006},
  language  = {en}
}
@article{BogoyavlenskiyBerezinOgnevaetal.1999,
  author    = {Bogoyavlenskiy, A. P. and Berezin, V. E. and Ogneva, A. V. and Tolmacheva, V. P. and Digel, Ilya and Khudyakova, S. S.},
  title     = {Immunostimulating activity of a saponin-containing extract of Saponaria officinalis},
  series = {Voprosy virusologii},
  volume    = {44},
  journal   = {Voprosy virusologii},
  number    = {5},
  issn      = {0507-4088},
  pages     = {229 -- 232},
  year      = {1999},
  language  = {en}
}
@incollection{DigelMansurovBiisenbaevetal.2012,
  author    = {Digel, Ilya and Mansurov, Zulkhair and Biisenbaev, Makhmut and Savitskaya, Irina and Kistaubaeva, Aida and Akimbekov, Nuraly and Zhubanova, Azhar},
  title     = {Heterogeneous Composites on the Basis of Microbial Cells and Nanostructured Carbonized Sorbents},
  series = {Composites and Their Applications},
  booktitle = {Composites and Their Applications},
  editor    = {Hu, Ning},
  publisher = {Intech},
  address   = {London},
  isbn      = {978-953-51-0706-4},
  doi       = {10.5772/47796},
  pages     = {249 -- 272},
  year      = {2012},
  abstract  = {The fact that microorganisms prefer to grow on liquid/solid phase surfaces rather than in the surrounding aqueous phase was noticed long time ago [1]. Virtually any surface - animal, mineral, or vegetable - is a subject for microbial colonization and subsequent biofilm formation. It would be adequate to name just a few notorious examples on microbial colonization of contact lenses, ship hulls, petroleum pipelines, rocks in streams and all kinds of biomedical implants. The propensity of microorganisms to become surface-bound is so profound and ubiquitous that it vindicates the advantages for attached forms over their free-ranging counterparts [2]. Indeed, from ecological and evolutionary standpoints, for many microorganisms the surface-bound state means dwelling in nutritionally favorable, non-hostile environments [3]. Therefore, in most of natural and artificial ecosystems surface-associated microorganisms vastly outnumber organisms in suspension and often organize into complex communities with features that differ dramatically from those of free cells [4].},
  language  = {en}
}
@book{Digel1998,
  author    = {Digel, Ilya},
  title     = {Enhancement of microbial adhesion onto solid surfaces using transition metals and water-soluble polymers : academic PhD dissertation in microbiology, Division of Applied Microbiology, Department of Microbiology, Biology Faculty, Kazakh National State University, Almaty, Kazakhstan / Ilya Digel},
  address   = {Almaty},
  year      = {1998},
  language  = {en}
}
@article{MansurovJandosovKerimkulovaetal.2014,
  author    = {Mansurov, Z. A. and Jandosov, J. M. and Kerimkulova, A. R. and Azat, S. and Zhubanova, A. A. and Digel, Ilya and Savistkaya, I. S. and Akimbekov, N. S. and Kistaubaeva, A. S.},
  title     = {Nanostructured carbon materials for biomedical use},
  series = {Eurasian chemico-technological journal : quarterly journal of the International Higher Education Academy of Sciences},
  volume    = {15 (2013)},
  journal   = {Eurasian chemico-technological journal : quarterly journal of the International Higher Education Academy of Sciences},
  number    = {3},
  publisher = {Institute of Combustion Problems},
  address   = {Almaty},
  issn      = {1562-3920},
  doi       = {10.18321/ectj224},
  pages     = {209 -- 217},
  year      = {2014},
  abstract  = {One of the priority trends of carbon nanotechnology is creation of nanocomposite systems. Such carbon nanostructured composites were produced using - raw materials based on the products of agricultural waste, such as grape stones, apricot stones, rice husk. These products have a - wide spectrum of application and can be obtained in large quantities. The Institute of Combustion Problems has carried out the work on synthesis of the nanostructured carbon sorbents for multiple applications including the field of biomedicine. The article presents the data on the synthesis and physico-chemical properties of carbonaceous sorbents using physicochemical methods of investigation: separation and purification of biomolecules; isolation of phytohormone - fusicoccin; adsorbent INGO-1 in the form of an adsorption column for blood detoxification, oral (entero) sorbent - INGO-2; the study of efferent and probiotic properties and sorption activity in regard to the lipopolysaccharide (LPS), new biocomposites - based on carbonized rice husk (CRH) and cellular microorganisms; the use of CRH in wound treatment. A new material for blood detoxication (INGO-1) has been obtained. Adsorption of p-cresyl sulfate and indoxyl sulfate has shown that active carbon adsorbent can remove clinically significant level of p-cresyl sulfate and indoxyl sulfate from human plasma. Enterosorbent INGO-2 possesses high adsorption activity in relation to Gram-negative bacteria and their endotoxins. INGO-2 slows down the growth of conditionally pathogenic microorganisms, without having a negative effect on bifido and lactobacteria. The use of enterosorbent INGO-2 for sorption therapy may provide a solution to a complex problem - detoxication of the digestive tract and normalization of the intestinal micro ecology. The immobilized probiotic called "Riso-lact" was registered at the Ministry of Health of the Republic of Kazakhstan as a biologically active food additive. The developed technology is patented and provides production of the medicine in the form of freeze-dried biomass immobilized in vials.},
  language  = {en}
}
@article{TuraliyevaYeshibaevDigeletal.2014,
  author    = {Turaliyeva, M. and Yeshibaev, A. and Digel, Ilya and Elibayeva, G. and Sydykova, A. and Uspabayeva, A. and Dosybayeva, G. and Zhylysbayeva, A. and Lakhanova, K.},
  title     = {Molecular-genetic identification of emerged novel invasive pathogens of Asiatic Elm Ulmus pumila L},
  series = {Life science journal},
  volume    = {11},
  journal   = {Life science journal},
  number    = {Spec. iss. 5s},
  publisher = {Marsland Press},
  address   = {New York},
  issn      = {1097-8135},
  doi       = {10.7537/marslsj1105s14.33},
  pages     = {171 -- 175},
  year      = {2014},
  abstract  = {The dwarf elm Ulmus pumila L. (Ulmaceae) is one of indigenous species of flora in Kazakhstan and forms a basis of dendroflora in virtually all settlements of the region. In the past decade, multiple outbreaks of previously unknown diseases of the small-leaved elm have been registered. In our study, by the molecular-genetic analysis it was found that the pathogens responsible for the outbreaks are microfungi belonging to the genus Fusarium - F. solani and F. oxysporum. The nucleotide sequences (ITS regions) isolated from the diseased trees showed very high similarity with the GenBank control numbers EU625403.1 and FJ478128.1 (100.0 and 99.0 \% respectively). Oncoming research will focus on the search of natural microbial antagonists of the discovered phytopathogens.},
  language  = {en}
}
@inproceedings{SchneiderAlHakimKayseretal.2017,
  author    = {Schneider, Oliver and Al Hakim, Taher and Kayser, Peter and Digel, Ilya},
  title     = {Development and trials of a test chamber for ultrasound-assisted sampling of living cells from solid surfaces},
  series = {2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West},
  booktitle = {2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West},
  editor    = {Erni, Daniel and Fischerauer, Alice and Himmel, J{\"o}rg and Seeger, Thomas and Thelen, Klaus},
  publisher = {Universit{\"a}t Duisburg-Essen},
  address   = {Duisburg},
  organization    = {MedTech Symposium},
  isbn      = {978-3-9814801-9-1},
  doi       = {10.17185/duepublico/43984},
  pages     = {96 -- 97},
  year      = {2017},
  language  = {en}
}
@inproceedings{KuhlenDigel2017,
  author    = {Kuhlen, Max and Digel, Ilya},
  title     = {Fluorescence signatures and detection limits of ubiquitous terrestrial bio-compounds},
  series = {2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West},
  booktitle = {2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West},
  editor    = {Erni, Daniel and Fischerauer, Alice and Himmel, J{\"o}rg and Seeger, Thomas and Thelen, Klaus},
  publisher = {Universit{\"a}t Duisburg-Essen},
  address   = {Duisburg},
  organization    = {MedTech Symposium},
  isbn      = {978-3-9814801-9-1},
  doi       = {10.17185/duepublico/43984},
  pages     = {102 -- 103},
  year      = {2017},
  language  = {en}
}
@inproceedings{deHondePorstDigel2017,
  author    = {de Honde, Lukas and Porst, Dariusz and Digel, Ilya},
  title     = {A randomized, observational thermographic study of the neck region before and after a physiotherapeutic intervention},
  series = {2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West},
  booktitle = {2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West},
  editor    = {Fischerauer, Alice},
  publisher = {Universit{\"a}t Duisburg-Essen},
  address   = {Duisburg},
  organization    = {MedTech Symposium},
  isbn      = {978-3-9814801-9-1},
  doi       = {10.17185/duepublico/43984},
  pages     = {122 -- 123},
  year      = {2017},
  language  = {en}
}
@incollection{DigelAkimbekovKistaubayevaetal.2018,
  author    = {Digel, Ilya and Akimbekov, Nuraly Sh. and Kistaubayeva, Aida and Zhubanova, Azhar A.},
  title     = {Microbial Sampling from Dry Surfaces: Current Challenges and Solutions},
  series = {Biological, Physical and Technical Basics of Cell Engineering},
  booktitle = {Biological, Physical and Technical Basics of Cell Engineering},
  editor    = {Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l and Zhubanova, Azhar A. and Digel, Ilya},
  publisher = {Springer},
  address   = {Singapore},
  isbn      = {978-981-10-7904-7},
  doi       = {10.1007/978-981-10-7904-7_19},
  pages     = {421 -- 456},
  year      = {2018},
  abstract  = {Sampling of dry surfaces for microorganisms is a main component of microbiological safety and is of critical importance in many fields including epidemiology, astrobiology as well as numerous branches of medical and food manufacturing. Aspects of biofilm formation, analysis and removal in aqueous solutions have been thoroughly discussed in literature. In contrast, microbial communities on air-exposed (dry) surfaces have received significantly less attention. Diverse surface sampling methods have been developed in order to address various surfaces and microbial groups, but they notoriously show poor repeatability, low recovery rates and suffer from lack of mutual consistency. Quantitative sampling for viable microorganisms represents a particular challenge, especially on porous and irregular surfaces. Therefore, it is essential to examine in depth the factors involved in microorganisms' recovery efficiency and accuracy depending on the sampling technique used. Microbial colonization, retention and community composition on different dry surfaces are very complex and rely on numerous physicochemical and biological factors. This study is devoted to analyze and review the (a) physical phenomena and intermolecular forces relevant for microbiological surface sampling; (b) challenges and problems faced by existing sampling methods for viable microorganisms and (c) current directions of engineering and research aimed at improvement of quality and efficiency of microbiological surface sampling.},
  language  = {en}
}
@inproceedings{AzarDigel2019,
  author    = {Azar, Fouad and Digel, Ilya},
  title     = {Utilization of fluorescence spectroscopy and neural networks in clinical analysis},
  series = {3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH Aachen},
  booktitle = {3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH Aachen},
  editor    = {Staat, Manfred and Erni, Daniel},
  publisher = {Universit{\"a}t Duisburg-Essen},
  address   = {Duisburg},
  organization    = {MedTech Symposium},
  isbn      = {978-3-940402-22-6},
  doi       = {10.17185/duepublico/48750},
  pages     = {40 -- 41},
  year      = {2019},
  abstract  = {Fluorescence topography of human urine in combination with learning algorithms can provide a variant pattern recognition method in analytical clinical chemistry and, eventually, diagnosis.},
  language  = {en}
}
@article{SavitskayaKistaubayevaIgnatovaetal.2019,
  author    = {Savitskaya, I.S. and Kistaubayeva, A.S. and Ignatova, L.V. and Digel, Ilya},
  title     = {Antimicrobial and wound healing properties of a bacterial cellulose based material containing B. subtilis cells},
  series = {Heliyon},
  volume    = {5},
  journal   = {Heliyon},
  number    = {10},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {2405-8440},
  doi       = {10.1016/j.heliyon.2019.e02592},
  pages     = {Artikelnummer e02592},
  year      = {2019},
  language  = {en}
}
@article{AkimbekovDigelTastambeketal.2013,
  author    = {Akimbekov, N. S. and Digel, Ilya and Tastambek, K. T. and Zhubanova, A. A.},
  title     = {Biocompatibility of carbonized rice husk with a rat heart cells line H9c2},
  series = {Experimental Biology},
  volume    = {59},
  journal   = {Experimental Biology},
  number    = {3/1},
  issn      = {1563-0218},
  pages     = {23 -- 25},
  year      = {2013},
  language  = {en}
}
@article{AkimbekovDigelSavitkayaetal.2013,
  author    = {Akimbekov, N.Sh. and Digel, Ilya and Savitkaya, I.S. and Zhubanova, A.A. and Tastambek, K.T.},
  title     = {Investigations of LPS endotoxin elimination in the flowing column conditions with the sorbent on the basis of carbonized rice husk},
  series = {KazNU Bulletin. Biology series},
  volume    = {57},
  journal   = {KazNU Bulletin. Biology series},
  number    = {1},
  issn      = {1563-0218},
  pages     = {124 -- 127},
  year      = {2013},
  language  = {en}
}
@article{AimenovaDigelEshibaev2016,
  author    = {Aimenova, Zh. E. and Digel, Ilya and Eshibaev, А. А.},
  title     = {Dynamics of accumulation of lagochirzin in Lagochilus setulosus phytomass during the growing season and also features of its cultivation in the conditions of a typical sierozem},
  series = {KazNU Bulletin. Biology series},
  volume    = {69},
  journal   = {KazNU Bulletin. Biology series},
  number    = {4},
  publisher = {Al-Farabi Kazakh National University},
  address   = {Almaty},
  issn      = {1563-0218},
  pages     = {4 -- 11},
  year      = {2016},
  abstract  = {L.setulosus is offered for creation of biopreparation «Setulin», possesing he- mostatic action, the basic reactant of biopreparation is diterpen - lagochirzin. Results under the maintenance and dynamics of diterpen lagochirzin accumula- tion in various parts of L.setulosus are presented: in roots, stalks, leaves, flowers and calyx lobes during the growing season, and also results on conditions of cultivation L.setulosus in the conditions of a typical sierozem are resulted. From the obtained data is visible, that the given species of a plant is endemic. It is established, that dynamics of accumulation of lagochirzin in phytomass accrues from the beginning to the middle of the growing season. The chemical analysis of L.setulosus on a localization of lagochirzin in various organs of a plant, has shown, that the greatest quantity of lagochirzin collects in calyx lobes of the plants. Also it is established, that L.setulosus can be cultivated in the conditions of the typical sierozem, a mineral food is necessary for the given species of plants of Lagochilus genus, except nitric fertilizers. Comparative studying of wild-growing and cultural forms of L.setulosus has shown, that in the cultivated phytomass of plants the maintenance of lagochirzin on 17-20 \% higher than in the wild-growing species.},
  language  = {en}
}
@article{DigelWehlitzKayseretal.2018,
  author    = {Digel, Ilya and Wehlitz, V. and Kayser, Peter and Figiel-Lange, A. and Bassam, R. and Rundstedt, F. von},
  title     = {Suspension depletion approach for exemption of infected Solanum jasminoides cells from pospiviroids},
  series = {Plant Pathology},
  volume    = {67},
  journal   = {Plant Pathology},
  number    = {2},
  publisher = {Wiley},
  address   = {Oxford},
  issn      = {1365-3059},
  doi       = {10.1111/ppa.12750},
  pages     = {358 -- 365},
  year      = {2018},
  abstract  = {Despite numerous studies, viroid elimination from infected plants remains a very challenging task. This study introduces for the first time a novel 'suspension depletion' approach for exemption of Solanum jasminoides plants from viroids. The proposed method implies initial establishment of suspension cultures of the infected plant cells. The suspended cells were then physically treated (mild thermotherapy, 33 °C), which presumably delayed the replication of the viroid. The viroid concentration in the treated biomass was monitored weekly using pospiviroid-specific PCR. After 10-12 weeks of continuous treatment, a sufficient decrease in viroid concentration was observed such that the infection became undetectable by PCR. The treated single cells then gave rise to microcolonies on a solid culture medium and the obtained viroid-negative clones were further promoted to regenerate into viroid-free plants. Three years of accumulated experimental data suggests feasibility, broad applicability, and good efficacy of the proposed approach.},
  language  = {en}
}
@article{MansurovDigelBiisenbaevetal.2012,
  author    = {Mansurov, Z. and Digel, Ilya and Biisenbaev, M. and Savistkaya, I. and Kistaubaeva, A. and Akimbekov, N. and Zhubanova, A.},
  title     = {Bio-composite material on the basis of carbonized rice husk in biomedicine and environmental applications},
  series = {Eurasian Chemico-Technological Journal},
  volume    = {14},
  journal   = {Eurasian Chemico-Technological Journal},
  number    = {2},
  publisher = {Institute of Combustion Problems},
  address   = {Almaty},
  issn      = {2522-4867},
  doi       = {10.18321/ectj105},
  pages     = {115 -- 131},
  year      = {2012},
  language  = {en}
}
@article{SavitskayaKistaubayevaDigeletal.2017,
  author    = {Savitskaya, I. S. and Kistaubayeva, A. S. and Digel, Ilya and Shokatayeva, D. H.},
  title     = {Physicochemical and Antibacterial Properties of Composite Films Based on Bacterial Cellulose and Chitosan for Wound Dressing Materials},
  series = {Eurasian Chemico-Technological Journal},
  volume    = {19},
  journal   = {Eurasian Chemico-Technological Journal},
  number    = {3},
  issn      = {2522-4867},
  doi       = {10.18321/ectj670},
  pages     = {255 -- 264},
  year      = {2017},
  language  = {en}
}
@article{AkimbekovDigelO’Herasetal.2015,
  author    = {Akimbekov, N.Sh. and Digel, Ilya and O'Heras, C. and Tastambek, K.T. and Savitskaya, I.S. and Ualyeva, P.S. and Mansurov, Z.A. and Zhubanova, A.A.},
  title     = {Adsorption of bacterial lipopol ysaccharides on carbonized ri ce husks obtained in the batch experiments},
  series = {KazNU Bulletin. Biology series},
  volume    = {60},
  journal   = {KazNU Bulletin. Biology series},
  number    = {No 1/2},
  issn      = {1563-0218},
  pages     = {144 -- 148},
  year      = {2015},
  language  = {en}
}
@inproceedings{SavitskayaKistaubayevaAkimbekovetal.2013,
  author    = {Savitskaya, Irina S. and Kistaubayeva, Aida S. and Akimbekov, Nuraly S. and Digel, Ilya and Zhubanova, Azhar A.},
  title     = {Performance of Bio-Composite Carbonized Materials in Probiotic Applications},
  series = {World Academy of Science, Engineering and Technology International Journal of Biotechnology and Bioengineering},
  volume    = {7},
  booktitle = {World Academy of Science, Engineering and Technology International Journal of Biotechnology and Bioengineering},
  number    = {7},
  pages     = {685 -- 689},
  year      = {2013},
  language  = {en}
}
@article{AkimbekovDigelOHerasetal.2014,
  author    = {Akimbekov, N.Sh. and Digel, Ilya and O´Heras, C. and Tastambek, K.T. and Savitskaya, I.S. and Ualyeva, P.S. and Mansurov, Z.A. and Zhubanova, A.A.},
  title     = {Adsorption of bacterial lipopolysaccharides on carbonized rice husks obtained in the batch experiments},
  series = {Experimental Biology},
  volume    = {60},
  journal   = {Experimental Biology},
  number    = {1/2},
  publisher = {Al-Farabi Kazakh National University},
  address   = {Almaty},
  issn      = {1563-0218},
  pages     = {144 -- 148},
  year      = {2014},
  abstract  = {The scope of this study is the measurement of endotoxin adsorption rate for carbonized rice husk. It showed good adsorption properties for LPS. During the batch experiments, several techniques were used and optimized for improving the material's adsorption behavior. Also, with the results obtained it was possible to differentiate the materials according to their adsorption capacity and kinetic characteristics.},
  language  = {en}
}
@article{AkimbekovDigelZhubanova2013,
  author    = {Akimbekov, N. Sh. and Digel, Ilya and Zhubanova, A. A.},
  title     = {Investigation the Influence of Carbonized Material Based On Rice Husk on Viability and Migration of Fibroblasts in T3B3 Cell Culture},
  series = {KazNU Bulletin. Biology series},
  volume    = {59},
  journal   = {KazNU Bulletin. Biology series},
  number    = {3/1},
  issn      = {1563-0218},
  pages     = {20 -- 23},
  year      = {2013},
  language  = {en}
}
@article{TurlybekulyPogrebnjakSukhodubetal.2019,
  author    = {Turlybekuly, Amanzhol and Pogrebnjak, Alexander and Sukhodub, L. F. and Sukhodub, Liudmyla B. and Kistaubayeva, A. S. and Savitskaya, Irina and Shokatayeva, D. H. and Bondar, Oleksandr V. and Shaimardanov, Z. K. and Plotnikov, Sergey V. and Shaimardanova, B. H. and Digel, Ilya},
  title     = {Synthesis, characterization, in vitro biocompatibility and antibacterial properties study of nanocomposite materials based on hydroxyapatite-biphasic ZnO micro- and nanoparticles embedded in Alginate matrix},
  series = {Materials Science and Engineering C},
  volume    = {104},
  journal   = {Materials Science and Engineering C},
  number    = {Article number 109965},
  publisher = {Elsevier},
  address   = {Amsterdam},
  doi       = {10.1016/j.msec.2019.109965},
  year      = {2019},
  language  = {en}
}
@article{AkimbekovDigelSherelkhanetal.2020,
  author    = {Akimbekov, Nuraly S. and Digel, Ilya and Sherelkhan, Dinara K. and Lutfor, Afzalunnessa B. and Razzaque, Mohammed S.},
  title     = {Vitamin D and the Host-Gut Microbiome: A Brief Overview},
  series = {Acta Histochemica et Cytochemica},
  volume    = {53},
  journal   = {Acta Histochemica et Cytochemica},
  number    = {3},
  publisher = {Japan Society of Histochemistry and Cytochemistry},
  address   = {Osaka},
  issn      = {1347-5800},
  doi       = {10.1267/ahc.20011},
  pages     = {33 -- 42},
  year      = {2020},
  abstract  = {There is a growing body of evidence for the effects of vitamin D on intestinal host-microbiome interactions related to gut dysbiosis and bowel inflammation. This brief review highlights the potential links between vitamin D and gut health, emphasizing the role of vitamin D in microbiological and immunological mechanisms of inflammatory bowel diseases. A comprehensive literature search was carried out in PubMed and Google Scholar using combinations of keywords "vitamin D," "intestines," "gut microflora," "bowel inflammation". Only articles published in English and related to the study topic are included in the review. We discuss how vitamin D (a) modulates intestinal microbiome function, (b) controls antimicrobial peptide expression, and (c) has a protective effect on epithelial barriers in the gut mucosa. Vitamin D and its nuclear receptor (VDR) regulate intestinal barrier integrity, and control innate and adaptive immunity in the gut. Metabolites from the gut microbiota may also regulate expression of VDR, while vitamin D may influence the gut microbiota and exert anti-inflammatory and immune-modulating effects. The underlying mechanism of vitamin D in the pathogenesis of bowel diseases is not fully understood, but maintaining an optimal vitamin D status appears to be beneficial for gut health. Future studies will shed light on the molecular mechanisms through which vitamin D and VDR interactions affect intestinal mucosal immunity, pathogen invasion, symbiont colonization, and antimicrobial peptide expression.},
  language  = {en}
}
@article{AkimbekovQiaoDigeletal.2020,
  author    = {Akimbekov, Nuraly and Qiao, Xiaohui and Digel, Ilya and Abdieva, Gulzhamal and Ualieva, Perizat and Zhubanova, Azhar},
  title     = {The effect of leonardite-derived amendments on soil microbiome structure and potato yield},
  series = {Agriculture},
  volume    = {10},
  journal   = {Agriculture},
  number    = {Art. 147},
  publisher = {MDPI},
  address   = {Basel},
  doi       = {10.3390/agriculture10050147},
  pages     = {1 -- 17},
  year      = {2020},
  abstract  = {Humic substances originating from various organic matters can ameliorate soil properties, stimulate plant growth, and improve nutrient uptake. Due to the low calorific heating value, leonardite is rather unsuitable as fuel. However, it may serve as a potential source of humic substances. This study was aimed at characterizing the leonardite-based soil amendments and examining the effect of their application on the soil microbial community, as well as on potato growth and tuber yield. A high yield (71.1\%) of humic acid (LHA) from leonardite has been demonstrated. Parental leonardite (PL) and LHA were applied to soil prior to potato cultivation. The 16S rRNA sequencing of soil samples revealed distinct relationships between microbial community composition and the application of leonardite-based soil amendments. Potato tubers were planted in pots in greenhouse conditions. The tubers were harvested at the mature stage for the determination of growth and yield parameters. The results demonstrated that the LHA treatments had a significant effect on increasing potato growth (54.9\%) and tuber yield (66.4\%) when compared to the control. The findings highlight the importance of amending leonardite-based humic products for maintaining the biogeochemical stability of soils, for keeping their healthy microbial community structure, and for increasing the agronomic productivity of potato plants.},
  language  = {en}
}
@article{ZhantlessovaSavitskayaKistaubayevaetal.2022,
  author    = {Zhantlessova, Sirina and Savitskaya, Irina and Kistaubayeva, Aida and Ignatova, Ludmila and Talipova, Aizhan and Pogrebnjak, Alexander and Digel, Ilya},
  title     = {Advanced "Green" prebiotic composite of bacterial cellulose/pullulan based on synthetic biology-powered microbial coculture strategy},
  series = {Polymers},
  volume    = {14},
  journal   = {Polymers},
  number    = {15},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2073-4360},
  doi       = {10.3390/polym14153224},
  pages     = {Artikel 3224},
  year      = {2022},
  abstract  = {Bacterial cellulose (BC) is a biopolymer produced by different microorganisms, but in biotechnological practice, Komagataeibacter xylinus is used. The micro- and nanofibrillar structure of BC, which forms many different-sized pores, creates prerequisites for the introduction of other polymers into it, including those synthesized by other microorganisms. The study aims to develop a cocultivation system of BC and prebiotic producers to obtain BC-based composite material with prebiotic activity. In this study, pullulan (PUL) was found to stimulate the growth of the probiotic strain Lactobacillus rhamnosus GG better than the other microbial polysaccharides gellan and xanthan. BC/PUL biocomposite with prebiotic properties was obtained by cocultivation of Komagataeibacter xylinus and Aureobasidium pullulans, BC and PUL producers respectively, on molasses medium. The inclusion of PUL in BC is proved gravimetrically by scanning electron microscopy and by Fourier transformed infrared spectroscopy. Cocultivation demonstrated a composite effect on the aggregation and binding of BC fibers, which led to a significant improvement in mechanical properties. The developed approach for "grafting" of prebiotic activity on BC allows preparation of environmentally friendly composites of better quality.},
  language  = {en}
}
@article{PogorelovaRogachevAkimbekovetal.2024,
  author    = {Pogorelova, Natalia and Rogachev, Evgeniy and Akimbekov, Nuraly and Digel, Ilya},
  title     = {Effect of dehydration method on the micro- and nanomorphological properties of bacterial cellulose produced by Medusomyces gisevii on different substrates},
  series = {Journal of materials science},
  volume    = {2024},
  journal   = {Journal of materials science},
  publisher = {Springer Science + Business Media},
  address   = {Dordrecht},
  issn      = {1573-4803 (Online)},
  doi       = {10.1007/s10853-024-09596-3},
  pages     = {13 Seiten},
  year      = {2024},
  abstract  = {Many important properties of bacterial cellulose (BC), such as moisture absorption capacity, elasticity and tensile strength, largely depend on its structure. This paper presents a study on the effect of the drying method on BC films produced by Medusomyces gisevii using two different procedures: room temperature drying (RT, (24 ± 2 °C, humidity 65 ± 1\%, dried until a constant weight was reached) and freeze-drying (FD, treated at - 75 °C for 48 h). BC was synthesized using one of two different carbon sources—either glucose or sucrose. Structural differences in the obtained BC films were evaluated using atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray diffraction. Macroscopically, the RT samples appeared semi-transparent and smooth, whereas the FD group exhibited an opaque white color and sponge-like structure. SEM examination showed denser packing of fibrils in FD samples while RT-samples displayed smaller average fiber diameter, lower surface roughness and less porosity. AFM confirmed the SEM observations and showed that the FD material exhibited a more branched structure and a higher surface roughness. The samples cultivated in a glucose-containing nutrient medium, generally displayed a straight and ordered shape of fibrils compared to the sucrose-derived BC, characterized by a rougher and wavier structure. The BC films dried under different conditions showed distinctly different crystallinity degrees, whereas the carbon source in the culture medium was found to have a relatively small effect on the BC crystallinity.},
  language  = {en}
}
@article{AkimbekovDigelAbdievaetal.2021,
  author    = {Akimbekov, Nuraly and Digel, Ilya and Abdieva, Gulzhamal and Ualieva, Perizat and Tastambek, Kuanysh},
  title     = {Lignite biosolubilization and bioconversion by Bacillus sp.: the collation of analytical data},
  series = {Biofuels},
  volume    = {12},
  journal   = {Biofuels},
  number    = {3},
  publisher = {Taylor \& Francis},
  address   = {London},
  issn      = {1759-7277},
  pages     = {247 -- 258},
  year      = {2021},
  abstract  = {The vast metabolic potential of microbes in brown coal (lignite) processing and utilization can greatly contribute to innovative approaches to sustainable production of high-value products from coal. In this study, the multi-faceted and complex coal biosolubilization process by Bacillus sp. RKB 7 isolate from the Kazakhstan coal-mining soil is reported, and the derived products are characterized. Lignite solubilization tests performed for surface and suspension cultures testify to the formation of numerous soluble lignite-derived substances. Almost 24\% of crude lignite (5\% w/v) was solubilized within 14 days under slightly alkaline conditions (pH 8.2). FTIR analysis revealed various functional groups in the obtained biosolubilization products. Analyses of the lignite-derived humic products by UV-Vis and fluorescence spectrometry as well as elemental analysis yielded compatible results indicating the emerging products had a lower molecular weight and degree of aromaticity. Furthermore, XRD and SEM analyses were used to evaluate the biosolubilization processes from mineralogical and microscopic points of view. The findings not only contribute to a deeper understanding of microbe-mineral interactions in coal environments, but also contribute to knowledge of coal biosolubilization and bioconversion with regard to sustainable production of humic substances. The detailed and comprehensive analyses demonstrate the huge biotechnological potential of Bacillus sp. for agricultural productivity and environmental health.},
  language  = {en}
}
@article{DigelKernGeenenetal.2020,
  author    = {Digel, Ilya and Kern, Inna and Geenen, Eva-Maria and Akimbekov, Nuraly},
  title     = {Dental plaque removal by ultrasonic toothbrushes},
  series = {dentistry journal},
  volume    = {8},
  journal   = {dentistry journal},
  number    = {28},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2304-6767},
  doi       = {10.3390/dj8010028},
  pages     = {1 -- 13},
  year      = {2020},
  abstract  = {With the variety of toothbrushes on the market, the question arises, which toothbrush is best suited to maintain oral health? This thematic review focuses first on plaque formation mechanisms and then on the plaque removal effectiveness of ultrasonic toothbrushes and their potential in preventing oral diseases like periodontitis, gingivitis, and caries. We overviewed the physical effects that occurred during brushing and tried to address the question of whether ultrasonic toothbrushes effectively reduced the microbial burden by increasing the hydrodynamic forces. The results of published studies show that electric toothbrushes, which combine ultrasonic and sonic (or acoustic and mechanic) actions, may have the most promising effect on good oral health. Existing ultrasonic/sonic toothbrush models do not significantly differ regarding the removal of dental biofilm and the reduction of gingival inflammation compared with other electrically powered toothbrushes, whereas the manual toothbrushes show a lower effectiveness.},
  language  = {en}
}
@incollection{AkimbekovDigelRazzaque2022,
  author    = {Akimbekov, Nuraly S. and Digel, Ilya and Razzaque, Mohammed S.},
  title     = {Role of vitamins in maintaining structure and function of intestinal microbiome},
  series = {Comprehensive Gut Microbiota},
  booktitle = {Comprehensive Gut Microbiota},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {978-0-12-822036-8},
  doi       = {10.1016/B978-0-12-819265-8.00043-7},
  pages     = {320 -- 334},
  year      = {2022},
  abstract  = {The recent advances in microbiology have shed light on understanding the role of vitamins beyond the nutritional range. Vitamins are critical in contributing to healthy biodiversity and maintaining the proper function of gut microbiota. The sharing of vitamins among bacterial populations promotes stability in community composition and diversity; however, this balance becomes disturbed in various pathologies. Here, we overview and analyze the ability of different vitamins to selectively and specifically induce changes in the intestinal microbial community. Some schemes and regularities become visible, which may provide new insights and avenues for therapeutic management and functional optimization of the gut microbiota.},
  language  = {en}
}