194 research outputs found

    The Differentiation Balance of Bone Marrow Mesenchymal Stem Cells Is Crucial to Hematopoiesis.

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    Bone marrow mesenchymal stem cells (BMSCs), the important component and regulator of bone marrow microenvironment, give rise to hematopoietic-supporting stromal cells and form hematopoietic niches for hematopoietic stem cells (HSCs). However, how BMSC differentiation affects hematopoiesis is poorly understood. In this review, we focus on the role of BMSC differentiation in hematopoiesis. We discussed the role of BMSCs and their progeny in hematopoiesis. We also examine the mechanisms that cause differentiation bias of BMSCs in stress conditions including aging, irradiation, and chemotherapy. Moreover, the differentiation balance of BMSCs is crucial to hematopoiesis. We highlight the negative effects of differentiation bias of BMSCs on hematopoietic recovery after bone marrow transplantation. Keeping the differentiation balance of BMSCs is critical for hematopoietic recovery. This review summarises current understanding about how BMSC differentiation affects hematopoiesis and its potential application in improving hematopoietic recovery after bone marrow transplantation

    Molecular insights into structural and dynamic properties of water molecules in calcium silicate hydrate nanopores: The roles of pore size and temperature

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    Calcium silicate hydrate is the primary hydration product of Portland cement and plays a crucial role in determining the strength of cement-based materials. The structural and dynamic properties of water molecules within calcium silicate hydrate nanopores have significant implications for the mechanical and durability performance of these materials. However, the influences of pore size and temperature on the properties of water molecules have not been fully explored. In this work, using molecular dynamics simulations and theoretical analysis, the evolution and mechanisms of the structural and dynamic properties of water molecules in different scenarios with various pore sizes and temperatures are systematically investigated. It is shown that the diffusion coefficients of water molecules increase with both pore size and temperature. Moreover, water molecules have a tendency to adsorb onto calcium silicate hydrate substrates, forming a distinct layered structure. As a result, the water molecules near the surfaces of calcium silicate hydrate substrates exhibit limited mobility, leading to smaller diffusion coefficients compared to those in other regions. Additionally, the distinctions in properties between water molecules and Ca2+ ions are elucidated and the underlying mechanisms behind these differences are also unveiled. The results and findings in this work deepen the understanding of structural and dynamic properties of water molecules within calcium silicate hydrate nanopores, providing valuable insights for improving the mechanical and durability performance of cement-based materials.Document Type:Ā Original articleCited as: Liu, S., A, H., Tang, S., Kai, M., Yang, Z. Molecular insights into structural and dynamic properties of water molecules in Calcium silicate hydrate nanopores: The roles of pore size and temperature. Capillarity, 2023, 8(2): 23-33. https://doi.org/10.46690/capi.2023.08.0

    LightBTSeg: A lightweight breast tumor segmentation model using ultrasound images via dual-path joint knowledge distillation

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    The accurate segmentation of breast tumors is an important prerequisite for lesion detection, which has significant clinical value for breast tumor research. The mainstream deep learning-based methods have achieved a breakthrough. However, these high-performance segmentation methods are formidable to implement in clinical scenarios since they always embrace high computation complexity, massive parameters, slow inference speed, and huge memory consumption. To tackle this problem, we propose LightBTSeg, a dual-path joint knowledge distillation framework, for lightweight breast tumor segmentation. Concretely, we design a double-teacher model to represent the fine-grained feature of breast ultrasound according to different semantic feature realignments of benign and malignant breast tumors. Specifically, we leverage the bottleneck architecture to reconstruct the original Attention U-Net. It is regarded as a lightweight student model named Simplified U-Net. Then, the prior knowledge of benign and malignant categories is utilized to design the teacher network combined dual-path joint knowledge distillation, which distills the knowledge from cumbersome benign and malignant teachers to a lightweight student model. Extensive experiments conducted on breast ultrasound images (Dataset BUSI) and Breast Ultrasound Dataset B (Dataset B) datasets demonstrate that LightBTSeg outperforms various counterparts.Comment: 7 pages, 7 figures, conferenc

    Promoting college studentsā€™ systems thinking in asynchronous discussions: Encouraging students initiating questions

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    IntroductionSystems thinking is one of the most important thinking skills for medical students. Most of the studies focused on designing technological-rich learning environments which usually take several weeks or months to implement. However, the occurring of COVID-19 health crisis does not allow extensive period of time to implement classroom interventions. How to support studentsā€™ systems thinking in fully online environments remains an issue. This study examines if encouraging students initiating questions on asynchronous discussion forum supports their systems thinking development.MethodsTwenty-two junior students participated in this study. We compared if and how students developed systems thinking when they were encouraged asking questions in asynchronous discussion forums in one unit with another unit in which traditional method was used. Multiple analytical methods were applied in this study, including, social network analysis, epistemic network analysis, inferential statistical analysis and qualitative analysis.ResultsQuantitative results showed that all students improved systems thinking compared with traditional teaching unit among which leader students improved most. Further analysis on studentsā€™ discussion posts suggested leader students asked high systems thinking level questions and provided high level responses. Epistemic network analysis unpacked how leader, regular and peripheral students engaged in initiating questions and providing responses differently.DiscussionThis study provides methodological and practical contributions. Methodologically, this study extends prior methods of applying network analysis beyond its original preservice teacher training contexts; practically, this study provides strategies to practitioners to support studentsā€™ asynchronous forum discussions

    Photochemical characteristics of diclofenac and its photodegradation of inclusion complexes with Ī²-cyclodextrins

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    Diclofenac is one of most frequently detected compounds in the water cycle. In this work, the effect of initial concentration, liquid inclusion complexes with Ī²-Cyclodextrins (Ī²-CDs) on the photodegradation of diclofenac were studied. Six phototransformation products were detected by HPLC chromatograms. UV-absorption spectra of diclofenac and phototransformation products were determined. One of the phototransformation products was identified. The degradation followed pseudo-first-order kinetics. The experiment showed that irradiation of diclofenac in the presence of Ī²-CDs increase photodegradation rate and determined the optimal molar ratio of diclofenac to Ī²-CDs as 1:2. The reduced photohaemolytic activity of diclofenac in the presence of Ī²-CDs may be attributed to the sequestering and stabilizing of the radical intermediates and /or photoproducts by complexation

    The effects of tai chi on markers of atherosclerosis, lower-limb physical function, and cognitive ability in adults aged over 60: A randomized controlled trial

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    Ā© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Objective: The purpose of this study was to investigate the effects of Tai Chi (TC) on arterial stiffness, physical function of lower-limb, and cognitive ability in adults aged over 60. Methods: This study was a prospective and randomized 12-week intervention trial with three repeated measurements (baseline, 6, and 12 weeks). Sixty healthy adults who met the inclusion criteria were randomly allocated into three training conditions (TC-24, TC-42, and TC-56) matched by gender, with 20 participants (10 males, 10 females) in each of the three groups. We measured the following health outcomes, including markers of atherosclerosis, physical function (leg power, and static and dynamic balance) of lower-limb, and cognitive ability. Results: When all three TC groups (p \u3c 0.05) have showed significant improvements on these outcomes but overall cognitive ability at 6 or 12 weeks training period, TC-56 appears to have superior effects on arterial stiffness and static/dynamic balance in the present study. Conclusions: Study results of the present study add to growing body of evidence regarding therapeutic TC for health promotion and disease prevention in aging population. Future studies should further determine whether TC-42 and TC-56 are beneficial for other non-Chinese populations, with rigorous research design and follow-up assessment
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