Chitosan has natural abundance, unique bioactivity and attractive physicochemical properties. Recent years, the synthesis of chitosan-based metal nanomaterials has attracted increasing attention. The synthesis of metal nanoparticles utilizing biomolecular or organism offers a mild medium, and thus a greater degree of control over the nanoparticles produced, along with higher reproducibility. In particular, preparation of metal nanoparticles based on biomolecular or organism has its unique facility in integrating "minimum feature sizes" into labile biological components to an excellent synergy and bifunctional effect and consequently a more broad application. Herein, we review the new development of chitosan, chitosan-based synthesis of metal nanomaterials, and their application.
Catalysis ; Chitosan ; chemistry ; Metal Nanoparticles ; chemistry ; Oxidation-Reduction

The purpose of the study was to investigate the influencing factors of mortality rate in the bone marrow transplantation in mice. The recipient mice receiving whole-body irradiation of gamma-ray were infused with the same strain of bone marrow cells or the mixture of the bone marrow cells and splenocytes respectively. Experiments were carried out in four batches, with different strains of mice used, respectively. The manifestations and the appearance of graft-versus-host disease (GVHD) were observed, as well as the mortality rate within 35 d of the transplantation in the recipient mice. The mortality rate of the first group of recipient mice was the lowest, the mortality rate of the second group of recipient mice was the highest and the obvious GVHD performance was observed before death. In the third group, the mortality rate declined and there was statistical significance compared to that of the second group. The mortality rate of the fourth group of mice was higher than that of the third group, but still lower than that of the second group of mice and there is a statistical significance. This evidence suggested that mouse genetic purity, splenocytes, the ratio of the bone marrow cells and splenocytes and the week-old of the mouse could be the important influencing factors of the mortality rate in mouse bone marrow transplantation.
Animals ; Bone Marrow Transplantation ; adverse effects ; methods ; mortality ; Cell Transplantation ; Female ; Graft vs Host Disease ; immunology ; mortality ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred ICR ; Mice, Transgenic ; Spleen ; cytology ; Survival Rate ; Whole-Body Irradiation

Objective:To investigate the protective role of Yes-associated protein(YAP)in intestinal epithelial barrier injury.Methods:The intestinal epithelial barrier model was established by culturing human colorectal adenocarcinoma cell line Caco-2 cells, which were divided into four groups: control group, Caco-2 monolayers did not receive any treatment; recombinant human tumor necrosis factor-α(rhTNF-α)group, 100 μg/L of rhTNF-α was added to Caco-2 monolayers; vector+ rhTNF-α group, Caco-2 monolayers were first added with control plasmid pcDNA3.1-vector, and 100 μg/L rhTNF-α was added 24 hours later; YAP+ rhTNF-α group, Caco-2 cells with barrier construction were first added with pcDNA3.1-YAP, and 100 μg/L rhTNF-α was added 24 hours later.Realtime-PCR and Western blot were used to evaluate YAP mRNA and protein expression level.Epithelial permeability was assayed by trans-epithelial electrical resistance(TEER)and fluorescein isothiocyanate-dextran 40(FD-40 flu). Cellular distribution of F-actin was assayed by immunofluorescence staining.Results:Compared with control group[(607.3±29.3)Ω·cm 2], TEER of rhTNF-α group[(265.3±32.7)Ω·cm 2] decreased, while TEER of YAP+ rhTNF-α group[(387.0±18.7)Ω·cm 2]increased compared with rhTNF-α group, the differences were statistically significant( P<0.001). The FD-40 flux of rhTNF-α(22.7%±0.5%) group was higher than that of the control group(6.3%±0.9%), while the FD-40 flux of Yap + rhTNF-α group(12.2%±0.8%) was lower than that of rhTNF-α group, the differences were statistically significant( P<0.001). Immunofluorescence staining showed that compared with the control group, the cytoskeletal F-actin fiber dense spot decreased in rhTNF-α group, and some cells showed obvious trans-cellular stress fiber structure, while the peripheral actin band was clear in YAP+ rhTNF-α group, and the intracellular stress fiber decreased.YAP+ TNF-α group appeared as a clear, peripheral actin ribbon with a decrease in cytoplasmic stress fibres. Conclusion:YAP overexpression significantly inhibits TNF-α induced decline of TEER, and increases of FD-40 flux and F-actin rearrangement of Caco-2.YAP could ameliorate TNF-α induced intestinal epithelial barrier injury by regulating cytoskeleton F-actin.

OBJECTIVE To provide referen ce for improving the application of health technology assessment （HTA） in decision-making for health insurance drugs in China. METHODS The application of HTA in decision-making for health insurance drugs in Britain ，France，Germany and Sweden were sorted out and analyzed from two aspects ：the establishment of HTA institutions and the process of HTA. The suggestions for improvement were put forward ，combined with the implementation of HTA in China. RESULTS & CONCLUSIONS Britain，France，Germany and Sweden have set up special HTA institutions ，which perform their respective duties and cooperate closely. During the implementation of HTA ，the above four countries have set different value assessment criteria to screen drugs with “high cost performance ”，all stakeholders actively participate ，make the evaluation results and decisions public ，set up objection handling links ，open a rapid evaluation channel to improve the accessibility of drugs ，and re-evaluate the drugs included in the reimbursement list to ensure the sustainability of medical insurance. It is suggested that China should combine the national conditions ，strengthen the cooperation of HTA institutions ，focus on talent training and comprehensive value assessment criteria ， promote stakeholder ’s participation ， improve the transparency of decision-making，and improve the implementation procedures of HTA in China.

Objective Taking three-dimensional (3D) motion capture system (MoCap) as the gold standard, a deep learning fusion model based on bi-lateral long short-term memory (BiLSTM) recurrent neural network and linear regression algorithm was developed to reduce system error of the Kinect sensor in lower limb kinematics measurement. Methods Ten healthy male college students were recruited for gait analysis. The 3D coordinates of the reflective markers and the lower limb joint centers were simultaneously collected using the MoCap system and the Kinect V2 sensor, respectively. The joint angles of lower limbs were calculated using the Cleveland clinic kinematic model and the Kinect kinematic model, respectively. The dataset was constructed using the MoCap system as the target and the angles via the Kinect system as the input. A BiLSTM network and a linear regression model for all lower limb angles were developed to obtain the refined angles. A leave-one subject-out cross-validation method was employed to study the performance of the models. The coefficient of multiple correlations (CMC) and root mean square error (RMSE) were used to investigate the similarity and the mean deviation between the joint angle waveforms via the MoCap and the Kinect system. ResultsIn comparison with the linear regression algorithm, the BiLSTM had better performance in the aspect of dealing highly nonlinear regression problems, especially for hip flexion/extension, hip adduction/abduction, and ankle dorsi/plantar flexion angles. The deep learning refined model significantly reduced the system error of Kinect. The mean RMSEs for all joint angles were mainly smaller than 10°, and the RMSEs of the hip joint were smaller than 5°. The joint angle waveforms presented very good similarity with the golden standard. The CMCs of joint angles were greater than 0.7 except for hip rotation angle. Conclusions The markerless gait analysis system based on deep learning fusion model developed in this study can accurately assess lower limb kinematics, joint mobility, walking functions, and has good prospect to be applied in clinical and home rehabilitation.

Indolylarylsulfones (IASs) are classical HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) with a unique scaffold and possess potent antiviral activity. To address the high cytotoxicity and improve safety profiles of IASs, we introduced various sulfonamide groups linked by alkyl diamine chain to explore the entrance channel of non-nucleoside inhibitors binding pocket. 48 compounds were designed and synthesized to evaluate their anti-HIV-1 activities and reverse transcriptase inhibition activities. Especially, compound R₁₀L₄ was endowed with significant inhibitory activity towards wild-type HIV-1 (EC_50(WT) = 0.007 μmol/L, SI = 30,930) as well as a panel of single-mutant strains exemplified by L100I (EC₅₀ = 0.017 μmol/L, SI = 13,055), E138K (EC₅₀ = 0.017 μmol/L, SI = 13,123) and Y181C (EC₅₀ = 0.045 μmol/L, SI = 4753) which were superior to Nevirapine and Etravirine. Notably, R₁₀L₄ was characterized with significantly reduced cytotoxicity (CC₅₀ = 216.51 μmol/L) and showed no remarkable in vivo toxic effects (acute and subacute toxicity). Moreover, the computer-based docking study was also employed to characterize the binding mode between R₁₀L₄ and HIV-1 RT. Additionally, R₁₀L₄ presented an acceptable pharmacokinetic profile. Collectively, these results deliver precious insights for next optimization and indicate that the sulfonamide IAS derivatives are promising NNRTIs for further development.

The main protease (M^pro) of SARS-CoV-2 is an attractive target in anti-COVID-19 therapy for its high conservation and major role in the virus life cycle. The covalent M^pro inhibitor nirmatrelvir (in combination with ritonavir, a pharmacokinetic enhancer) and the non-covalent inhibitor ensitrelvir have shown efficacy in clinical trials and have been approved for therapeutic use. Effective antiviral drugs are needed to fight the pandemic, while non-covalent M^pro inhibitors could be promising alternatives due to their high selectivity and favorable druggability. Numerous non-covalent M^pro inhibitors with desirable properties have been developed based on available crystal structures of M^pro. In this article, we describe medicinal chemistry strategies applied for the discovery and optimization of non-covalent M^pro inhibitors, followed by a general overview and critical analysis of the available information. Prospective viewpoints and insights into current strategies for the development of non-covalent M^pro inhibitors are also discussed.