@article{SchoenrockMuckeltHastermannetal.2024,
  author    = {Schoenrock, Britt and Muckelt, Paul E. and Hastermann, Maria and Albracht, Kirsten and MacGregor, Robert and Martin, David and Gunga, Hans-Christian and Salanova, Michele and Stokes, Maria J. and Warner, Martin B. and Blottner, Dieter},
  title     = {Muscle stiffness indicating mission crew health in space},
  series = {Scientific Reports},
  volume    = {14},
  journal   = {Scientific Reports},
  number    = {Article number: 4196},
  publisher = {Springer Nature},
  address   = {London},
  issn      = {2045-2322},
  doi       = {10.1038/s41598-024-54759-6},
  pages     = {13 Seiten},
  year      = {2024},
  abstract  = {Muscle function is compromised by gravitational unloading in space affecting overall musculoskeletal health. Astronauts perform daily exercise programmes to mitigate these effects but knowing which muscles to target would optimise effectiveness. Accurate inflight assessment to inform exercise programmes is critical due to lack of technologies suitable for spaceflight. Changes in mechanical properties indicate muscle health status and can be measured rapidly and non-invasively using novel technology. A hand-held MyotonPRO device enabled monitoring of muscle health for the first time in spaceflight (> 180 days). Greater/maintained stiffness indicated countermeasures were effective. Tissue stiffness was preserved in the majority of muscles (neck, shoulder, back, thigh) but Tibialis Anterior (foot lever muscle) stiffness decreased inflight vs. preflight (p < 0.0001; mean difference 149 N/m) in all 12 crewmembers. The calf muscles showed opposing effects, Gastrocnemius increasing in stiffness Soleus decreasing. Selective stiffness decrements indicate lack of preservation despite daily inflight countermeasures. This calls for more targeted exercises for lower leg muscles with vital roles as ankle joint stabilizers and in gait. Muscle stiffness is a digital biomarker for risk monitoring during future planetary explorations (Moon, Mars), for healthcare management in challenging environments or clinical disorders in people on Earth, to enable effective tailored exercise programmes.},
  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{ZhenLiangStaatetal.2024,
  author    = {Zhen, Manghao and Liang, Yunpei and Staat, Manfred and Li, Quanqui and Li, Jianbo},
  title     = {Discontinuous fracture behaviors and constitutive model of sandstone specimens containing non-parallel prefabricated fissures under uniaxial compression},
  series = {Theoretical and Applied Fracture Mechanics},
  volume    = {131},
  journal   = {Theoretical and Applied Fracture Mechanics},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0167-8442},
  doi       = {10.1016/j.tafmec.2024.104373},
  pages     = {Artikel 104373},
  year      = {2024},
  abstract  = {The deformation and damage laws of non-homogeneous irregular structural planes in rocks are the basis for studying the stability of rock engineering. To investigate the damage characteristics of rock containing non-parallel fissures, uniaxial compression tests and numerical simulations were conducted on sandstone specimens containing three non-parallel fissures inclined at 0°, 45° and 90° in this study. The characteristics of crack initiation and crack evolution of fissures with different inclinations were analyzed. A constitutive model for the discontinuous fractures of fissured sandstone was proposed. The results show that the fracture behaviors of fissured sandstone specimens are discontinuous. The stress-strain curves are non-smooth and can be divided into nonlinear crack closure stage, linear elastic stage, plastic stage and brittle failure stage, of which the plastic stage contains discontinuous stress drops. During the uniaxial compression test, the middle or ends of 0° fissures were the first to crack compared to 45° and 90° fissures. The end with small distance between 0° and 45° fissures cracked first, and the end with large distance cracked later. After the final failure, 0° fissures in all specimens were fractured, while 45° and 90° fissures were not necessarily fractured. Numerical simulation results show that the concentration of compressive stress at the tips of 0°, 45° and 90° fissures, as well as the concentration of tensile stress on both sides, decreased with the increase of the inclination angle. A constitutive model for the discontinuous fractures of fissured sandstone specimens was derived by combining the logistic model and damage mechanic theory. This model can well describe the discontinuous drops of stress and agrees well with the whole processes of the stress-strain curves of the fissured sandstone specimens.},
  language  = {en}
}
@article{LiphardtFernandezGonzaloAlbrachtetal.2023,
  author    = {Liphardt, Anna-Maria and Fernandez-Gonzalo, Rodrigo and Albracht, Kirsten and Rittweger, J{\"o}rn and Vico, Laurence},
  title     = {Musculoskeletal research in human space flight - unmet needs for the success of crewed deep space exploration},
  series = {npj Microgravity},
  volume    = {9},
  journal   = {npj Microgravity},
  number    = {Article number: 9},
  publisher = {Springer Nature},
  issn      = {2373-8065},
  doi       = {10.1038/s41526-023-00258-3},
  pages     = {1 -- 9},
  year      = {2023},
  abstract  = {Based on the European Space Agency (ESA) Science in Space Environment (SciSpacE) community White Paper "Human Physiology - Musculoskeletal system", this perspective highlights unmet needs and suggests new avenues for future studies in musculoskeletal research to enable crewed exploration missions. The musculoskeletal system is essential for sustaining physical function and energy metabolism, and the maintenance of health during exploration missions, and consequently mission success, will be tightly linked to musculoskeletal function. Data collection from current space missions from pre-, during-, and post-flight periods would provide important information to understand and ultimately offset musculoskeletal alterations during long-term spaceflight. In addition, understanding the kinetics of the different components of the musculoskeletal system in parallel with a detailed description of the molecular mechanisms driving these alterations appears to be the best approach to address potential musculoskeletal problems that future exploratory-mission crew will face. These research efforts should be accompanied by technical advances in molecular and phenotypic monitoring tools to provide in-flight real-time feedback.},
  language  = {en}
}
@article{SavitskayaZhantlessovaKistaubayevaetal.2023,
  author    = {Savitskaya, Irina and Zhantlessova, Sirina and Kistaubayeva, Aida and Ignatova, Ludmila and Shokatayeva, Dina and Sinyavsky, Yuriy and Kushugulova, Almagul and Digel, Ilya},
  title     = {Prebiotic cellulose-pullulan matrix as a "vehicle" for probiotic biofilm delivery to the host large intestine},
  series = {Polymers},
  journal   = {Polymers},
  number    = {16(1)},
  publisher = {MDPI},
  address   = {Basel},
  doi       = {10.3390/polym16010030},
  pages     = {Artikel 30},
  year      = {2023},
  abstract  = {This study describes the development of a new combined polysaccharide-matrix-based technology for the immobilization of Lactobacillus rhamnosus GG (LGG) bacteria in biofilm form. The new composition allows for delivering the bacteria to the digestive tract in a manner that improves their robustness compared with planktonic cells and released biofilm cells. Granules consisting of a polysaccharide matrix with probiotic biofilms (PMPB) with high cell density (>9 log CFU/g) were obtained by immobilization in the optimized nutrient medium. Successful probiotic loading was confirmed by fluorescence microscopy and scanning electron microscopy. The developed prebiotic polysaccharide matrix significantly enhanced LGG viability under acidic (pH 2.0) and bile salt (0.3\%) stress conditions. Enzymatic extract of feces, mimicking colon fluid in terms of cellulase activity, was used to evaluate the intestinal release of probiotics. PMPB granules showed the ability to gradually release a large number of viable LGG cells in the model colon fluid. In vivo, the oral administration of PMPB granules in rats resulted in the successful release of probiotics in the colon environment. The biofilm-forming incubation method of immobilization on a complex polysaccharide matrix tested in this study has shown high efficacy and promising potential for the development of innovative biotechnologies.},
  language  = {en}
}
@article{HeieisBoeckerD'Angeloetal.2023,
  author    = {Heieis, Jule and B{\"o}cker, Jonas and D'Angelo, Olfa and Mittag, Uwe and Albracht, Kirsten and Sch{\"o}nau, Eckhard and Meyer, Andreas and Voigtmann, Thomas and Rittweger, J{\"o}rn},
  title     = {Curvature of gastrocnemius muscle fascicles as function of muscle-tendon complex length and contraction in humans},
  series = {Physiological Reports},
  volume    = {11},
  journal   = {Physiological Reports},
  number    = {11},
  publisher = {Wiley},
  issn      = {2051-817X},
  doi       = {10.14814/phy2.15739},
  pages     = {e15739, Seite 1-11},
  year      = {2023},
  abstract  = {It has been shown that muscle fascicle curvature increases with increasing contraction level and decreasing muscle-tendon complex length. The analyses were done with limited examination windows concerning contraction level, muscle-tendon complex length, and/or intramuscular position of ultrasound imaging. With this study we aimed to investigate the correlation between fascicle arching and contraction, muscle-tendon complex length and their associated architectural parameters in gastrocnemius muscles to develop hypotheses concerning the fundamental mechanism of fascicle curving. Twelve participants were tested in five different positions (90°/105°*, 90°/90°*, 135°/90°*, 170°/90°*, and 170°/75°*; *knee/ankle angle). They performed isometric contractions at four different contraction levels (5\%, 25\%, 50\%, and 75\% of maximum voluntary contraction) in each position. Panoramic ultrasound images of gastrocnemius muscles were collected at rest and during constant contraction. Aponeuroses and fascicles were tracked in all ultrasound images and the parameters fascicle curvature, muscle-tendon complex strain, contraction level, pennation angle, fascicle length, fascicle strain, intramuscular position, sex and age group were analyzed by linear mixed effect models. Mean fascicle curvature of the medial gastrocnemius increased with contraction level (+5 m-1 from 0\% to 100\%; p = 0.006). Muscle-tendon complex length had no significant impact on mean fascicle curvature. Mean pennation angle (2.2 m-1 per 10°; p < 0.001), inverse mean fascicle length (20 m-1 per cm-1; p = 0.003), and mean fascicle strain (-0.07 m-1 per +10\%; p = 0.004) correlated with mean fascicle curvature. Evidence has also been found for intermuscular, intramuscular, and sex-specific intramuscular differences of fascicle curving. Pennation angle and the inverse fascicle length show the highest predictive capacities for fascicle curving. Due to the strong correlations between pennation angle and fascicle curvature and the intramuscular pattern of curving we suggest for future studies to examine correlations between fascicle curvature and intramuscular fluid pressure.},
  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{WaldvogelFreylerHelmetal.2023,
  author    = {Waldvogel, Janice and Freyler, Kathrin and Helm, Michael and Monti, Elena and St{\"a}udle, Benjamin and Gollhofer, Albert and Narici, Marco V. and Ritzmann, Ramona and Albracht, Kirsten},
  title     = {Changes in gravity affect neuromuscular control, biomechanics, and muscle-tendon mechanics in energy storage and dissipation tasks},
  series = {Journal of Applied Physiology},
  volume    = {134},
  journal   = {Journal of Applied Physiology},
  number    = {1},
  publisher = {American Physiological Society},
  address   = {Bethesda, Md.},
  issn      = {1522-1601 (Onlineausgabe)},
  doi       = {10.1152/japplphysiol.00279.2022},
  pages     = {190 -- 202},
  year      = {2023},
  abstract  = {This study evaluates neuromechanical control and muscle-tendon interaction during energy storage and dissipation tasks in hypergravity. During parabolic flights, while 17 subjects performed drop jumps (DJs) and drop landings (DLs), electromyography (EMG) of the lower limb muscles was combined with in vivo fascicle dynamics of the gastrocnemius medialis, two-dimensional (2D) kinematics, and kinetics to measure and analyze changes in energy management. Comparisons were made between movement modalities executed in hypergravity (1.8 G) and gravity on ground (1 G). In 1.8 G, ankle dorsiflexion, knee joint flexion, and vertical center of mass (COM) displacement are lower in DJs than in DLs; within each movement modality, joint flexion amplitudes and COM displacement demonstrate higher values in 1.8 G than in 1 G. Concomitantly, negative peak ankle joint power, vertical ground reaction forces, and leg stiffness are similar between both movement modalities (1.8 G). In DJs, EMG activity in 1.8 G is lower during the COM deceleration phase than in 1 G, thus impairing quasi-isometric fascicle behavior. In DLs, EMG activity before and during the COM deceleration phase is higher, and fascicles are stretched less in 1.8 G than in 1 G. Compared with the situation in 1 G, highly task-specific neuromuscular activity is diminished in 1.8 G, resulting in fascicle lengthening in both movement modalities. Specifically, in DJs, a high magnitude of neuromuscular activity is impaired, resulting in altered energy storage. In contrast, in DLs, linear stiffening of the system due to higher neuromuscular activity combined with lower fascicle stretch enhances the buffering function of the tendon, and thus the capacity to safely dissipate energy.},
  language  = {en}
}
@article{DigelAkimbekovRogachevetal.2023,
  author    = {Digel, Ilya and Akimbekov, Nuraly and Rogachev, Evgeniy and Pogorelova, Natalia},
  title     = {Bacterial cellulose produced by Medusomyces gisevii on glucose and sucrose: biosynthesis and structural properties},
  series = {Cellulose},
  journal   = {Cellulose},
  publisher = {Springer Science + Business Media},
  address   = {Dordrecht},
  issn      = {1572-882X (Online)},
  doi       = {10.1007/s10570-023-05592-z},
  pages     = {15 Seiten},
  year      = {2023},
  abstract  = {In this work, the effects of carbon sources and culture media on the production and structural properties of bacterial cellulose (BC) synthesized by Medusomyces gisevii have been studied. The culture medium was composed of different initial concentrations of glucose or sucrose dissolved in 0.4\% extract of plain green tea. Parameters of the culture media (titratable acidity, substrate conversion degree etc.) were monitored daily for 20 days of cultivation. The BC pellicles produced on different carbon sources were characterized in terms of biomass yield, crystallinity and morphology by field emission scanning electron microscopy (FE-SEM), atomic force microscopy and X-ray diffraction. Our results showed that Medusomyces gisevii had higher BC yields in media with sugar concentrations close to 10 g L-1 after a 18-20 days incubation period. Glucose in general lead to a higher BC yield (173 g L-1) compared to sucrose (163.5 g L-1). The BC crystallinity degree and surface roughness were higher in the samples synthetized from sucrose. Obtained FE-SEM micrographs show that the BC pellicles synthesized in the sucrose media contained densely packed tangles of cellulose fibrils whereas the BC produced in the glucose media displayed rather linear geometry of the BC fibrils without noticeable aggregates.},
  language  = {en}
}
@article{AlnemerKotliarNeuhausetal.2023,
  author    = {Alnemer, Momin Sami Mohammad and Kotliar, Konstantin and Neuhaus, Valentin and Pape, Hans-Christoph and Ciritsis, Bernhard D.},
  title     = {Cost-effectiveness analysis of surgical proximal femur fracture prevention in elderly: a Markov cohort simulation model},
  series = {Cost Effectiveness and Resource Allocation},
  journal   = {Cost Effectiveness and Resource Allocation},
  number    = {21, Article number: 77},
  publisher = {Springer Nature},
  issn      = {1478-7547},
  doi       = {10.1186/s12962-023-00482-4},
  pages     = {12 Seiten},
  year      = {2023},
  abstract  = {Background Hip fractures are a common and costly health problem, resulting in significant morbidity and mortality, as well as high costs for healthcare systems, especially for the elderly. Implementing surgical preventive strategies has the potential to improve the quality of life and reduce the burden on healthcare resources, particularly in the long term. However, there are currently limited guidelines for standardizing hip fracture prophylaxis practices. Methods This study used a cost-effectiveness analysis with a finite-state Markov model and cohort simulation to evaluate the primary and secondary surgical prevention of hip fractures in the elderly. Patients aged 60 to 90 years were simulated in two different models (A and B) to assess prevention at different levels. Model A assumed prophylaxis was performed during the fracture operation on the contralateral side, while Model B included individuals with high fracture risk factors. Costs were obtained from the Centers for Medicare \& Medicaid Services, and transition probabilities and health state utilities were derived from available literature. The baseline assumption was a 10\% reduction in fracture risk after prophylaxis. A sensitivity analysis was also conducted to assess the reliability and variability of the results. Results With a 10\% fracture risk reduction, model A costs between \$8,850 and \$46,940 per quality-adjusted life-year (\$/QALY). Additionally, it proved most cost-effective in the age range between 61 and 81 years. The sensitivity analysis established that a reduction of ≥ 2.8\% is needed for prophylaxis to be definitely cost-effective. The cost-effectiveness at the secondary prevention level was most sensitive to the cost of the contralateral side's prophylaxis, the patient's age, and fracture treatment cost. For high-risk patients with no fracture history, the cost-effectiveness of a preventive strategy depends on their risk profile. In the baseline analysis, the incremental cost-effectiveness ratio at the primary prevention level varied between \$11,000/QALY and \$74,000/QALY, which is below the defined willingness to pay threshold. Conclusion Due to the high cost of hip fracture treatment and its increased morbidity, surgical prophylaxis strategies have demonstrated that they can significantly relieve the healthcare system. Various key assumptions facilitated the modeling, allowing for adequate room for uncertainty. Further research is needed to evaluate health-state-associated risks.},
  language  = {en}
}
@article{WerfelGuenthnerHapfelmeieretal.2022,
  author    = {Werfel, Stanislas and G{\"u}nthner, Roman and Hapfelmeier, Alexander and Hanssen, Henner and Kotliar, Konstantin and Heemann, Uwe and Schmaderer, Christoph},
  title     = {Identification of cardiovascular high-risk groups from dynamic retinal vessel signals using untargeted machine learning},
  series = {Cardiovascular Research},
  volume    = {118},
  journal   = {Cardiovascular Research},
  number    = {2},
  editor    = {Guzik, Tomasz J.},
  publisher = {Oxford University Press},
  address   = {Oxford},
  issn      = {0008-6363},
  doi       = {10.1093/cvr/cvab040},
  pages     = {612 -- 621},
  year      = {2022},
  abstract  = {Dynamic retinal vessel analysis (DVA) provides a non-invasive way to assess microvascular function in patients and potentially to improve predictions of individual cardiovascular (CV) risk. The aim of our study was to use untargeted machine learning on DVA in order to improve CV mortality prediction and identify corresponding response alterations.},
  language  = {en}
}
@article{HeinEubanksLingametal.2022,
  author    = {Hein, Andreas M. and Eubanks, T. Marshall and Lingam, Manasvi and Hibberd, Adam and Fries, Dan and Schneider, Jean and Kervella, Pierre and Kennedy, Robert and Perakis, Nikolaos and Dachwald, Bernd},
  title     = {Interstellar now! Missions to explore nearby interstellar objects},
  series = {Advances in Space Research},
  volume    = {69},
  journal   = {Advances in Space Research},
  number    = {1},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0273-1177},
  doi       = {10.1016/j.asr.2021.06.052},
  pages     = {402 -- 414},
  year      = {2022},
  abstract  = {The recently discovered first hyperbolic objects passing through the Solar System, 1I/'Oumuamua and 2I/Borisov, have raised the question about near term missions to Interstellar Objects. In situ spacecraft exploration of these objects will allow the direct determination of both their structure and their chemical and isotopic composition, enabling an entirely new way of studying small bodies from outside our solar system. In this paper, we map various Interstellar Object classes to mission types, demonstrating that missions to a range of Interstellar Object classes are feasible, using existing or near-term technology. We describe flyby, rendezvous and sample return missions to interstellar objects, showing various ways to explore these bodies characterizing their surface, dynamics, structure and composition. Their direct exploration will constrain their formation and history, situating them within the dynamical and chemical evolution of the Galaxy. These mission types also provide the opportunity to explore solar system bodies and perform measurements in the far outer solar system.},
  language  = {en}
}
@article{MalinowskiFournierHorbachetal.2022,
  author    = {Malinowski, Daniel and Fournier, Yvan and Horbach, Andreas and Frick, Michael and Magliani, Mirko and Kalverkamp, Sebastian and Hildinger, Martin and Spillner, Jan and Behbahani, Mehdi and Hima, Flutura},
  title     = {Computational fluid dynamics analysis of endoluminal aortic perfusion},
  series = {Perfusion},
  volume    = {0},
  journal   = {Perfusion},
  number    = {0},
  publisher = {Sage},
  address   = {London},
  issn      = {1477-111X},
  doi       = {10.1177/02676591221099809},
  pages     = {1 -- 8},
  year      = {2022},
  abstract  = {Introduction: In peripheral percutaneous (VA) extracorporeal membrane oxygenation (ECMO) procedures the femoral arteries perfusion route has inherent disadvantages regarding poor upper body perfusion due to watershed. With the advent of new long flexible cannulas an advancement of the tip up to the ascending aorta has become feasible. To investigate the impact of such long endoluminal cannulas on upper body perfusion, a Computational Fluid Dynamics (CFD) study was performed considering different support levels and three cannula positions. Methods: An idealized literature-based- and a real patient proximal aortic geometry including an endoluminal cannula were constructed. The blood flow was considered continuous. Oxygen saturation was set to 80\% for the blood coming from the heart and to 100\% for the blood leaving the cannula. 50\% and 90\% venoarterial support levels from the total blood flow rate of 6 l/min were investigated for three different positions of the cannula in the aortic arch. Results: For both geometries, the placement of the cannula in the ascending aorta led to a superior oxygenation of all aortic blood vessels except for the left coronary artery. Cannula placements at the aortic arch and descending aorta could support supra-aortic arteries, but not the coronary arteries. All positions were able to support all branches with saturated blood at 90\% flow volume. Conclusions: In accordance with clinical observations CFD analysis reveals, that retrograde advancement of a long endoluminal cannula can considerably improve the oxygenation of the upper body and lead to oxygen saturation distributions similar to those of a central cannulation.},
  language  = {en}
}
@article{LenzKahmannBehbahanietal.2022,
  author    = {Lenz, Maximilian and Kahmann, Stephanie Lucina and Behbahani, Mehdi and Pennig, Lenhard and Hackl, Michael and Leschinger, Tim and M{\"u}ller, Lars Peter and Wegmann, Kilian},
  title     = {Influence of rotator cuff preload on fracture configuration in proximal humerus fractures: a proof of concept for fracture simulation},
  series = {Archives of Orthopaedic and Trauma Surgery},
  journal   = {Archives of Orthopaedic and Trauma Surgery},
  publisher = {Springer},
  address   = {Berlin, Heidelberg},
  issn      = {1434-3916},
  doi       = {10.1007/s00402-022-04471-9},
  year      = {2022},
  abstract  = {Introduction In regard of surgical training, the reproducible simulation of life-like proximal humerus fractures in human cadaveric specimens is desirable. The aim of the present study was to develop a technique that allows simulation of realistic proximal humerus fractures and to analyse the influence of rotator cuff preload on the generated lesions in regards of fracture configuration. Materials and methods Ten cadaveric specimens (6 left, 4 right) were fractured using a custom-made drop-test bench, in two groups. Five specimens were fractured without rotator cuff preload, while the other five were fractured with the tendons of the rotator cuff preloaded with 2 kg each. The humeral shaft and the shortened scapula were potted. The humerus was positioned at 90° of abduction and 10° of internal rotation to simulate a fall on the elevated arm. In two specimens of each group, the emergence of the fractures was documented with high-speed video imaging. Pre-fracture radiographs were taken to evaluate the deltoid-tuberosity index as a measure of bone density. Post-fracture X-rays and CT scans were performed to define the exact fracture configurations. Neer's classification was used to analyse the fractures. Results In all ten cadaveric specimens life-like proximal humerus fractures were achieved. Two III-part and three IV-part fractures resulted in each group. The preloading of the rotator cuff muscles had no further influence on the fracture configuration. High-speed videos of the fracture simulation revealed identical fracture mechanisms for both groups. We observed a two-step fracture mechanism, with initial impaction of the head segment against the glenoid followed by fracturing of the head and the tuberosities and then with further impaction of the shaft against the acromion, which lead to separation of the tuberosities. Conclusion A high energetic axial impulse can reliably induce realistic proximal humerus fractures in cadaveric specimens. The preload of the rotator cuff muscles had no influence on initial fracture configuration. Therefore, fracture simulation in the proximal humerus is less elaborate. Using the presented technique, pre-fractured specimens are available for real-life surgical education.},
  language  = {en}
}
@article{ChloeMalyaranCraveiroetal.2022,
  author    = {Chlo{\´e}, Radermacher and Malyaran, Hanna and Craveiro, Rogerio Bastos and Peglow, Sarah and Behbahani, Mehdi and Pufe, Thomas and Wolf, Michael and Neuss, Sabine},
  title     = {Mechanical loading on cementoblasts: a mini review},
  series = {Osteologie},
  volume    = {31},
  journal   = {Osteologie},
  number    = {2},
  publisher = {Thieme},
  address   = {Stuttgart},
  issn      = {1019-1291},
  doi       = {10.1055/a-1826-0777},
  pages     = {111 -- 118},
  year      = {2022},
  abstract  = {Orthodontic treatments are concomitant with mechanical forces and thereby cause teeth movements. The applied forces are transmitted to the tooth root and the periodontal ligaments which is compressed on one side and tensed up on the other side. Indeed, strong forces can lead to tooth root resorption and the crown-to-tooth ratio is reduced with the potential for significant clinical impact. The cementum, which covers the tooth root, is a thin mineralized tissue of the periodontium that connects the periodontal ligament with the tooth and is build up by cementoblasts. The impact of tension and compression on these cells is investigated in several in vivo and in vitro studies demonstrating differences in protein expression and signaling pathways. In summary, osteogenic marker changes indicate that cyclic tensile forces support whereas static tension inhibits cementogenesis. Furthermore, cementogenesis experiences the same protein expression changes in static conditions as static tension, but cyclic compression leads to the exact opposite of cyclic tension. Consistent with marker expression changes, the singaling pathways of Wnt/ß-catenin and RANKL/OPG show that tissue compression leads to cementum degradation and tension forces to cementogenesis. However, the cementum, and in particular its cementoblasts, remain a research area which should be explored in more detail to understand the underlying mechanism of bone resorption and remodeling after orthodontic treatments.},
  language  = {en}
}
@article{UysalCreutzFiratetal.2022,
  author    = {Uysal, Karya and Creutz, Till and Firat, Ipek Seda and Artmann, Gerhard and Teusch, Nicole and Temiz Artmann, Ayseg{\"u}l},
  title     = {Bio-functionalized ultra-thin, large-area and waterproof silicone membranes for biomechanical cellular loading and compliance experiments},
  series = {Polymers},
  volume    = {14},
  journal   = {Polymers},
  number    = {11},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2073-4360},
  pages     = {2213},
  year      = {2022},
  abstract  = {Biocompatibility, flexibility and durability make polydimethylsiloxane (PDMS) membranes top candidates in biomedical applications. CellDrum technology uses large area, <10 µm thin membranes as mechanical stress sensors of thin cell layers. For this to be successful, the properties (thickness, temperature, dust, wrinkles, etc.) must be precisely controlled. The following parameters of membrane fabrication by means of the Floating-on-Water (FoW) method were investigated: (1) PDMS volume, (2) ambient temperature, (3) membrane deflection and (4) membrane mechanical compliance. Significant differences were found between all PDMS volumes and thicknesses tested (p < 0.01). They also differed from the calculated values. At room temperatures between 22 and 26 °C, significant differences in average thickness values were found, as well as a continuous decrease in thicknesses within a 4 °C temperature elevation. No correlation was found between the membrane thickness groups (between 3-4 µm) in terms of deflection and compliance. We successfully present a fabrication method for thin bio-functionalized membranes in conjunction with a four-step quality management system. The results highlight the importance of tight regulation of production parameters through quality control. The use of membranes described here could also become the basis for material testing on thin, viscous layers such as polymers, dyes and adhesives, which goes far beyond biological applications.},
  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{TopcuMadabhushiStaat2022,
  author    = {Top{\c{c}}u, Murat and Madabhushi, Gopal S.P. and Staat, Manfred},
  title     = {A generalized shear-lag theory for elastic stress transfer between matrix and fibres having a variable radius},
  series = {International Journal of Solids and Structures},
  volume    = {239-240},
  journal   = {International Journal of Solids and Structures},
  number    = {Art. No. 111464},
  publisher = {Elsevier},
  address   = {New York, NY},
  issn      = {0020-7683},
  doi       = {10.1016/j.ijsolstr.2022.111464},
  year      = {2022},
  abstract  = {A generalized shear-lag theory for fibres with variable radius is developed to analyse elastic fibre/matrix stress transfer. The theory accounts for the reinforcement of biological composites, such as soft tissue and bone tissue, as well as for the reinforcement of technical composite materials, such as fibre-reinforced polymers (FRP). The original shear-lag theory proposed by Cox in 1952 is generalized for fibres with variable radius and with symmetric and asymmetric ends. Analytical solutions are derived for the distribution of axial and interfacial shear stress in cylindrical and elliptical fibres, as well as conical and paraboloidal fibres with asymmetric ends. Additionally, the distribution of axial and interfacial shear stress for conical and paraboloidal fibres with symmetric ends are numerically predicted. The results are compared with solutions from axisymmetric finite element models. A parameter study is performed, to investigate the suitability of alternative fibre geometries for use in FRP.},
  language  = {en}
}
@article{MandekarHollandThielenetal.2022,
  author    = {Mandekar, Swati and Holland, Abigail and Thielen, Moritz and Behbahani, Mehdi and Melnykowycz, Mark},
  title     = {Advancing towards Ubiquitous EEG, Correlation of In-Ear EEG with Forehead EEG},
  series = {Sensors},
  volume    = {22},
  journal   = {Sensors},
  number    = {4},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1424-8220},
  doi       = {10.3390/s22041568},
  pages     = {1 -- 19},
  year      = {2022},
  abstract  = {Wearable EEG has gained popularity in recent years driven by promising uses outside of clinics and research. The ubiquitous application of continuous EEG requires unobtrusive form-factors that are easily acceptable by the end-users. In this progression, wearable EEG systems have been moving from full scalp to forehead and recently to the ear. The aim of this study is to demonstrate that emerging ear-EEG provides similar impedance and signal properties as established forehead EEG. EEG data using eyes-open and closed alpha paradigm were acquired from ten healthy subjects using generic earpieces fitted with three custom-made electrodes and a forehead electrode (at Fpx) after impedance analysis. Inter-subject variability in in-ear electrode impedance ranged from 20 kΩ to 25 kΩ at 10 Hz. Signal quality was comparable with an SNR of 6 for in-ear and 8 for forehead electrodes. Alpha attenuation was significant during the eyes-open condition in all in-ear electrodes, and it followed the structure of power spectral density plots of forehead electrodes, with the Pearson correlation coefficient of 0.92 between in-ear locations ELE (Left Ear Superior) and ERE (Right Ear Superior) and forehead locations, Fp1 and Fp2, respectively. The results indicate that in-ear EEG is an unobtrusive alternative in terms of impedance, signal properties and information content to established forehead EEG.},
  language  = {en}
}
@article{DefosseKleinschmidtSchmutzetal.2022,
  author    = {Defosse, Jerome and Kleinschmidt, Joris and Schmutz, Axel and Loop, Torsten and Staat, Manfred and Gatzweiler, Karl-Heinz and Wappler, Frank and Schieren, Mark},
  title     = {Dental strain on maxillary incisors during tracheal intubation with double-lumen tubes and different laryngoscopy techniques - a blinded manikin study},
  series = {Journal of Cardiothoracic and Vascular Anesthesia},
  volume    = {36},
  journal   = {Journal of Cardiothoracic and Vascular Anesthesia},
  number    = {8, Part B},
  publisher = {Elsevier},
  address   = {New York, NY},
  issn      = {1053-0770},
  doi       = {10.1053/j.jvca.2022.02.017},
  pages     = {3021 -- 3027},
  year      = {2022},
  language  = {en}
}