bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wavelength of a Turing-type mechanism regulates the morphogenesis of meshwork patterns
Authors: Guo Shan , Sun Ming-zhu , Zhao Xin 
Published: March 2021

AbstractThe meshwork pattern is a significant pattern in the development of biological tissues and organs. It is necessary to explore the mathematical mechanism of meshwork pattern formation. In this paper, we found that the meshwork pattern is formed by four kinds of stalk behaviours: stalk extension, tip bifurcation, side branching and tip fusion. The Turing-type pattern underlying the meshwork pattern is a Turing spot pattern, which indicates that the Turing instability of the spot pattern promotes activator peak formation and then guides the formation of meshwork patterns. Then, we found that the Turing wavelength decreased in turn from tip bifurcation to side branching to tip fusion via statistical evaluation. Through the functional relationship between the Turing wavelength and model parameters ($$\upvarepsilon ,{ \rho }_{A}$$

ε
,

ρ
A

and $${\rho }_{H}$$

ρ
H

), we found that parameters $$\upvarepsilon $$
ε
and $${\rho }_{H}$$

ρ
H

had monotonic effects on the Turing wavelength and that parameter $${\rho }_{A}$$

ρ
A

had nonmonotonic effects. Furthermore, we performed simulations of local meshwork pattern formation under variable model parameter values. The simulation results verified the corresponding relationship between the Turing wavelength and stalk behaviours and the functional relationship between the Turing wavelength and model parameters. The simulation results showed that the Turing wavelength regulated the meshwork pattern and that the small Turing wavelength facilitated dense meshwork pattern formation. Our work provides novel insight into and understanding of the formation of meshwork patterns. We believe that studies associated with network morphogenesis can benefit from our work.
Biglycan expression and its function in human ligamentum flavum
Authors: Salimi Hamidullah , Suzuki Akinobu , Habibi Hasibullah , Orita Kumi , Hori Yusuke , Yabu Akito , Terai Hidetomi , Tamai Koji , Nakamura Hiroaki 
Published: March 2021

AbstractHypertrophy of the ligamentum flavum (LF) is a major cause of lumbar spinal stenosis (LSS), and the pathology involves disruption of elastic fibers, fibrosis with increased cellularity and collagens, and/or calcification. Previous studies have implicated the increased expression of the proteoglycan family in hypertrophied LF. Furthermore, the gene expression profile in a rabbit experimental model of LF hypertrophy revealed that biglycan (BGN) is upregulated in hypertrophied LF by mechanical stress. However, the expression and function of BGN in human LF has not been well elucidated. To investigate the involvement of BGN in the pathomechanism of human ligamentum hypertrophy, first we confirmed increased expression of BGN by immunohistochemistry in the extracellular matrix of hypertrophied LF of LSS patients compared to LF without hypertrophy. Experiments using primary cell cultures revealed that BGN promoted cell proliferation. Furthermore, BGN induces changes in cell morphology and promotes myofibroblastic differentiation and cell migration. These effects are observed for both cells from hypertrophied and non-hypertrophied LF. The present study revealed hyper-expression of BGN in hypertrophied LF and function of increased proteoglycan in LF cells. BGN may play a crucial role in the pathophysiology of LF hypertrophy through cell proliferation, myofibroblastic differentiation, and cell migration.
Exploration in the mechanism of fucosterol for the treatment of non-small cell lung cancer based on network pharmacology and molecular docking
Authors: Li Xiaoling , Lin Baixin , Lin Zhiping , Ma Yucui , Wang Qu , Zheng Yushi , Cui Liao , Luo Hui , Luo Lianxiang 
Published: March 2021

AbstractFucosterol, a sterol isolated from brown algae, has been demonstrated to have anti-cancer properties. However, the effects and underlying molecular mechanism of fucosterol on non-small cell lung cancer remain to be elucidated. In this study, the corresponding targets of fucosterol were obtained from PharmMapper, and NSCLC related targets were gathered from the GeneCards database, and the candidate targets of fucosterol-treated NSCLC were predicted. The mechanism of fucosterol against NSCLC was identified in DAVID6.8 by enrichment analysis of GO and KEGG, and protein–protein interaction data were collected from STRING database. The hub gene GRB2 was further screened out and verified by molecular docking. Moreover, the relationship of GRB2 expression and immune infiltrates were analyzed by the TIMER database. The results of network pharmacology suggest that fucosterol acts against candidate targets, such as MAPK1, EGFR, GRB2, IGF2, MAPK8, and SRC, which regulate biological processes including negative regulation of the apoptotic process, peptidyl-tyrosine phosphorylation, positive regulation of cell proliferation. The Raf/MEK/ERK signaling pathway initiated by GRB2 showed to be significant in treating NSCLC. In conclusion, our study indicates that fucosterol may suppress NSCLC progression by targeting GRB2 activated the Raf/MEK/ERK signaling pathway, which laying a theoretical foundation for further research and providing scientific support for the development of new drugs.
Localization accuracy of multiple magnets in a myokinetic control interface
Authors: Gherardini Marta , Clemente Francesco , Milici Stefano , Cipriani Christian 
Published: March 2021

AbstractMagnetic localizers have been widely investigated in the biomedical field, especially for intra-body applications, because they don’t require a free line-of-sight between the implanted magnets and the magnetic field sensors. However, while researchers have focused on narrow and specific aspects of the localization problem, no one has comprehensively searched for general design rules for accurately localizing multiple magnetic objectives. In this study, we sought to systematically analyse the effects of remanent magnetization, number of sensors, and geometrical configuration (i.e. distance among magnets—Linter-MM—and between magnets and sensors—LMM-sensor) on the accuracy of the localizer in order to unveil the basic principles of the localization problem. Specifically, through simulations validated with a physical system, we observed that the accuracy of the localization was mainly affected by a specific angle ($$\theta$$
θ
= tan−1(Linter-MM / LMM-sensor)), descriptive of the system geometry. In particular, while tracking nine magnets, errors below ~ 1 mm (10% of the length of the simulated trajectory) and around 9° were obtained if θ ≥  ~ 31°. The latter proved a general rule across all tested conditions, also when the number of magnets was doubled. Our results are interesting for a whole range of biomedical engineering applications exploiting multiple-magnets tracking, such as human–machine interfaces, capsule endoscopy, ventriculostomy interventions, and endovascular catheter navigation.
Absence of X-chromosome dosage compensation in the primordial germ cells of Drosophila embryos
Authors: Ota Ryoma , Hayashi Makoto , Morita Shumpei , Miura Hiroki , Kobayashi Satoru 
Published: March 2021

AbstractDosage compensation is a mechanism that equalizes sex chromosome gene expression between the sexes. In Drosophila, individuals with two X chromosomes (XX) become female, whereas males have one X chromosome (XY). In males, dosage compensation of the X chromosome in the soma is achieved by five proteins and two non-coding RNAs, which assemble into the male-specific lethal (MSL) complex to upregulate X-linked genes twofold. By contrast, it remains unclear whether dosage compensation occurs in the germline. To address this issue, we performed transcriptome analysis of male and female primordial germ cells (PGCs). We found that the expression levels of X-linked genes were approximately twofold higher in female PGCs than in male PGCs. Acetylation of lysine residue 16 on histone H4 (H4K16ac), which is catalyzed by the MSL complex, was undetectable in these cells. In male PGCs, hyperactivation of X-linked genes and H4K16ac were induced by overexpression of the essential components of the MSL complex, which were expressed at very low levels in PGCs. Together, these findings indicate that failure of MSL complex formation results in the absence of X-chromosome dosage compensation in male PGCs.
Frequency-dependent interactions determine outcome of competition between two breast cancer cell lines
Authors: Freischel Audrey R. , Damaghi Mehdi , Cunningham Jessica J. , Ibrahim-Hashim Arig , Gillies Robert J. , Gatenby Robert A. , Brown Joel S. 
Published: March 2021

AbstractTumors are highly dynamic ecosystems in which diverse cancer cell subpopulations compete for space and resources. These complex, often non-linear interactions govern continuous spatial and temporal changes in the size and phenotypic properties of these subpopulations. Because intra-tumoral blood flow is often chaotic, competition for resources may be a critical selection factor in progression and prognosis. Here, we quantify resource competition using 3D spheroid cultures with MDA-MB-231 and MCF-7 breast cancer cells. We hypothesized that MCF-7 cells, which primarily rely on efficient aerobic glucose metabolism, would dominate the population under normal pH and low glucose conditions; and MDA-MB-231 cells, which exhibit high levels of glycolytic metabolism, would dominate under low pH and high glucose conditions. In spheroids with single populations, MCF-7 cells exhibited equal or superior intrinsic growth rates (density-independent measure of success) and carrying capacities (density-dependent measure of success) when compared to MDA-MB-231 cells under all pH and nutrient conditions. Despite these advantages, when grown together, MCF-7 cells do not always outcompete MDA-MB-231 cells. MDA-MB-231 cells outcompete MCF-7 cells in low glucose conditions and coexistence is achieved in low pH conditions. Under all conditions, MDA-MB-231 has a stronger competitive effect (frequency-dependent interaction) on MCF-7 cells than vice-versa. This, and the inability of growth rate or carrying capacity when grown individually to predict the outcome of competition, suggests a reliance on frequency-dependent interactions and the need for competition assays. We frame these results in a game-theoretic (frequency-dependent) model of cancer cell interactions and conclude that competition assays can demonstrate critical density-independent, density-dependent and frequency-dependent interactions that likely contribute to in vivo outcomes.
The histone replacement gene His4r is involved in heat stress induced chromatin rearrangement
Authors: Faragó Anikó , Ürmösi Adél , Farkas Anita , Bodai László 
Published: March 2021

AbstractHis4r is the only known variant of histone H4 in Drosophila. It is encoded by the His4r single-copy gene that is located outside of the histone gene cluster and expressed in a different pattern than H4, although the encoded polypeptides are identical. We generated a null mutant (His4rΔ42) which is homozygous viable and fertile without any apparent morphological defects. Heterozygous His4rΔ42 is a mild suppressor of position-effect variegation, suggesting that His4r has a role in the formation or maintenance of condensed chromatin. Under standard conditions loss of His4r has a modest effect on gene expression. Upon heat-stress the induction of the Heat shock protein (HSP) genes Hsp27 and Hsp68 is stronger in His4rΔ42 mutants with concordantly increased survival rate. Analysis of chromatin accessibility after heat shock at a Hsp27 regulatory region showed less condensed chromatin in the absence of His4r while there was no difference at the gene body. Interestingly, preconditioning before heat shock led to increased chromatin accessibility, HSP gene transcription and survival rate in control flies while it did not cause notable changes in His4rΔ42. Thus, our results suggest that His4r might play a role in fine tuning chromatin structure at inducible gene promoters upon environmental stress conditions.
Cerebral functional networks during sleep in young and older individuals
Authors: Daneault Véronique , Orban Pierre , Martin Nicolas , Dansereau Christian , Godbout Jonathan , Pouliot Philippe , Dickinson Philip , Gosselin Nadia , Vandewalle Gilles , Maquet Pierre , Lina Jean-Marc , Doyon Julien , Bellec Pierre , Carrier Julie 
Published: March 2021

AbstractEven though sleep modification is a hallmark of the aging process, age-related changes in functional connectivity using functional Magnetic Resonance Imaging (fMRI) during sleep, remain unknown. Here, we combined electroencephalography and fMRI to examine functional connectivity differences between wakefulness and light sleep stages (N1 and N2 stages) in 16 young (23.1 ± 3.3y; 7 women), and 14 older individuals (59.6 ± 5.7y; 8 women). Results revealed extended, distributed (inter-between) and local (intra-within) decreases in network connectivity during sleep both in young and older individuals. However, compared to the young participants, older individuals showed lower decreases in connectivity or even increases in connectivity between thalamus/basal ganglia and several cerebral regions as well as between frontal regions of various networks. These findings reflect a reduced ability of the older brain to disconnect during sleep that may impede optimal disengagement for loss of responsiveness, enhanced lighter and fragmented sleep, and contribute to age effects on sleep-dependent brain plasticity.
Betweenness centrality for temporal multiplexes
Authors: Zaoli Silvia , Mazzarisi Piero , Lillo Fabrizio 
Published: March 2021

AbstractBetweenness centrality quantifies the importance of a vertex for the information flow in a network. The standard betweenness centrality applies to static single-layer networks, but many real world networks are both dynamic and made of several layers. We propose a definition of betweenness centrality for temporal multiplexes. This definition accounts for the topological and temporal structure and for the duration of paths in the determination of the shortest paths. We propose an algorithm to compute the new metric using a mapping to a static graph. We apply the metric to a dataset of $$\sim 20$$

∼
20

k European flights and compare the results with those obtained with static or single-layer metrics. The differences in the airports rankings highlight the importance of considering the temporal multiplex structure and an appropriate distance metric.
Repair of segmental bone defect using tissue engineered heterogeneous deproteinized bone doped with lithium
Authors: Li Jun , Wang Wenzhao , Li Mingxin , Liu Lei 
Published: March 2021

AbstractLithium have been shown to play an important role in improving the osteogenic properties of biomaterials. This study aims to explore the osteogenic improvement effect of tissue engineered heterogeneous deproteinized bone (HDPB) doped with lithium, and evaluate their effectiveness in the healing of bone defects. Bone marrow mesenchymal stem cells (BMSCs) were co-cultured with different concentration of lithium chloride. Cell proliferation in each group was analyzed by 3-(4, 5-dimetyl-2-thiazoly-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay. BMSCs were then co-cultured in osteogenic induction medium with different concentration of lithium chloride, and the expression of related mRNA was detected. The role of lithium in promoting BMSCs osteogenic differentiation and inhibiting BMSCs lipogenic differentiation was also investigated. Biomechanical properties of the tibia were evaluated at 8 weeks after operation. The tibial specimens of each group were collected at 4 and 8 weeks after surgery for histological examination and histological analysis. Micro-computed tomography (CT) scanning and 3D reconstruction were performed at 8 weeks. The results demonstrate that lithium can induce the osteogenic differentiation inhibit of adipogenic differentiation of BMSCs by regulating the Wnt signaling pathway. The histological evaluation further certified that average bone formation area in the group of tissue engineered HDPB doped with lithium was also significantly better than that of HDPB alone group. Based on the above evaluation, tissue engineered HDPB doped with lithium can effectively promote the regeneration of segmental bone defect, which can be used as a tissue engineering scaffold for clinical trials.
Marine cyanobacterium Spirulina maxima as an alternate to the animal cell culture medium supplement
Authors: Jeong Younsik , Choi Woon-Yong , Park Areumi , Lee Yeon-Ji , Lee Youngdeuk , Park Gun-Hoo , Lee Su-Jin , Lee Won-Kyu , Ryu Yong-Kyun , Kang Do-Hyung 
Published: March 2021

AbstractSerum is a stable medium supplement for in vitro cell culture. Live cells are used in stem cell research, drug toxicity and safety testing, disease diagnosis and prevention, and development of antibiotics, drugs, and vaccines. However, use of serum in culture involves concerns such as an ethical debate regarding the collection process, lack of standardized ingredients, and high cost. Herein, therefore, we evaluated the possibility of using edible cyanobacterium (Spirulina maxima), which is a nutrient-rich, sustainable, and ethically acceptable source, as a novel substitute for fetal bovine serum (FBS). H460 cells were cultured to the 10th generation by adding a mixture of spirulina animal cell culture solution (SACCS) and FBS to the culture medium. Cell morphology and viability, cell cycle, apoptosis, proteomes, and transcriptomes were assessed. We observed that SACCS had better growth-promoting capabilities than FBS. Cell proliferation was promoted even when FBS was replaced by 50–70% SACCS; there was no significant difference in cell shape or viability. There were only slight differences in the cell cycle, apoptosis, proteomes, and transcriptomes of the cells grown in presence of SACCS. Therefore, SACCS has the potential to be an effective, low-cost, and eco-friendly alternative to FBS in in vitro culture.
Differential effect of anesthetics on mucociliary clearance in vivo in mice
Authors: Feldman Kyle S. , Kim Eunwon , Czachowski Michael J. , Wu Yijen , Lo Cecilia W. , Zahid Maliha 
Published: March 2021

AbstractRespiratory mucociliary clearance (MCC) is a key defense mechanism that functions to entrap and transport inhaled pollutants, particulates, and pathogens away from the lungs. Previous work has identified a number of anesthetics to have cilia depressive effects in vitro. Wild-type C57BL/6 J mice received intra-tracheal installation of 99mTc-Sulfur colloid, and were imaged using a dual-modality SPECT/CT system at 0 and 6 h to measure baseline MCC (n = 8). Mice were challenged for one hour with inhalational 1.5% isoflurane, or intraperitoneal ketamine (100 mg/kg)/xylazine (20 mg/kg), ketamine (0.5 mg/kg)/dexmedetomidine (50 mg/kg), fentanyl (0.2 mg/kg)/1.5% isoflurane, propofol (120 mg/Kg), or fentanyl/midazolam/dexmedetomidine (0.025 mg/kg/2.5 mg/kg/0.25 mg/kg) prior to MCC assessment. The baseline MCC was 6.4%, and was significantly reduced to 3.7% (p = 0.04) and 3.0% (p = 0.01) by ketamine/xylazine and ketamine/dexmedetomidine challenge respectively. Importantly, combinations of drugs containing fentanyl, and propofol in isolation did not significantly depress MCC. Although no change in cilia length or percent ciliation was expected, we tried to correlate ex-vivo tracheal cilia ciliary beat frequency and cilia-generated flow velocities with MCC and found no correlation. Our results indicate that anesthetics containing ketamine (ketamine/xylazine and ketamine/dexmedetomidine) significantly depress MCC, while combinations containing fentanyl (fentanyl/isoflurane, fentanyl/midazolam/dexmedetomidine) and propofol do not. Our method for assessing MCC is reproducible and has utility for studying the effects of other drug combinations.
Code-free deep learning for multi-modality medical image classification
Authors: Korot Edward , Guan Zeyu , Ferraz Daniel , Wagner Siegfried K. , Zhang Gongyu , Liu Xiaoxuan , Faes Livia , Pontikos Nikolas , Finlayson Samuel G. , Khalid Hagar , Moraes Gabriella , Balaskas Konstantinos , Denniston Alastair K. , Keane Pearse A. 
Published: March 2021

AbstractA number of large technology companies have created code-free cloud-based platforms that allow researchers and clinicians without coding experience to create deep learning algorithms. In this study, we comprehensively analyse the performance and featureset of six platforms, using four representative cross-sectional and en-face medical imaging datasets to create image classification models. The mean (s.d.) F1 scores across platforms for all model–dataset pairs were as follows: Amazon, 93.9 (5.4); Apple, 72.0 (13.6); Clarifai, 74.2 (7.1); Google, 92.0 (5.4); MedicMind, 90.7 (9.6); Microsoft, 88.6 (5.3). The platforms demonstrated uniformly higher classification performance with the optical coherence tomography modality. Potential use cases given proper validation include research dataset curation, mobile ‘edge models’ for regions without internet access, and baseline models against which to compare and iterate bespoke deep learning approaches.
Hybrid access and adaptive duty cycle clustering protocol for ultra‐low power wireless sensor networks
Authors: Al‐Sulaifanie Adnan Ismail , Al‐Sulaifanie Bayez Khorsheed 
Published: March 2021

AbstractThis paper investigates many drawbacks and limitations of current clustering algorithms designed for wireless sensor networks. These limitations include high resource requirements, significant overhead, tight synchronization requirements, and TDMA limitations. A new clustering algorithm called hybrid access and an adaptive duty cycle clustering (HADC) protocol is introduced, aiming to address the previous limitations. HADC protocol is based on several concepts, including static clusters, adaptive duty cycling, hybrid scheme channel access, minimum node's functionality, and pseudo synchronization. The resulting network's important features are energy efficiency, robustness, low latency, scalability, and self‐healing. The functionality of HADC is validated by both simulation and laboratory experiments. Simulation results show significant improvement of HADC over the well‐known LEACH protocol in terms of energy, latency, and packet delivery ratio. The experiment results show that the node's lifetime with two 3000 mAh batteries and transmitting four packets per minute is about 16 years. The lifetime of the cluster head supported by the same energy sources ranges from 110 to 472 days. HADC is the first clustering algorithm designed for sporadic and low rate WSN applications to the best of authors' knowledge.
Das Tablet als Standard in der Klinik – mobile digitale Patientenakten und mobiler Workflow
Authors: Lohmann Rüdiger , Schrage Talitha , Rußow Gabriele 
Published: March 2021

ZusammenfassungDie Digitalisierung hat auch in der Medizin zunehmenden Einzug gefunden. Eine Vielzahl an digitalen Patientenakten sind auf dem Markt verfügbar, unter anderem auch App-basierte Lösungen auf handelsüblichen Tablet-Computern. Der Tablet-Computer eignet sich dank hoher Leistungsfähigkeit und guter Mobilität besonders um eine digitale mobile Patientenakte zu realisieren. Die Etablierung dieser Tablets in den klinischen Alltag stellt Voraussetzungen an Technik, Datenschutz, Hygiene, Mitarbeiter und die erweiterte Infrastruktur; ermöglicht jedoch eine Erleichterung der interdisziplinären und interprofessionellen Kommunikation, eine sicherere Dokumentation und eine optimierte Patientenversorgung. Auf die essenziellen Schritte und Voraussetzungen, sowie die Vor- und Nachteile zur Umsetzung der Tablets in den klinischen Alltag wird in diesem Artikel anhand der App Checkpad MED eingegangen.