BACKGROUND:Clinical skin wound healing continues to be a significant concern,and tissue repair research has moved to the forefront with the development of biomaterials with immunomodulatory properties.Therefore,it is crucial to research wound dressings that have immunomodulatory properties. OBJECTIVE:To prepare chitosan hydrogels that have been modified by arginine with different configurations and assess their capacity to speed up wound healing in a rat animal model. METHODS:(1)In vitro trial:Chitosan modified by pure L-arginine,pure D-arginine,and L-arginine and D-arginine was synthesized by EDC/NHS system,which was then crosslinked with aldehyde-modified four-arm polyethylene glycol.Different chitosan-based hydrogels(CS-L,CS-D,and CS-DL)were finally formed via the Schiff base reaction.Three kinds of hydrogel extracts were co-cultured with fibroblasts respectively.Hydrogel cytocompatibility was assessed using the CCK-8 assay and live/dead staining.The effect of hydrogel on the migration capacity of fibroblasts was assessed by using a scratch test.Three kinds of hydrogels were incubated with rat erythrocyte suspension respectively to evaluate the hemocompatibility of the hydrogels.The hydrogel extract was co-cultured with RAW264.7 macrophages to test the hydrogels'capacity to enhance macrophage NO generation and polarize macrophage phenotype.(2)In vivo experiment:A total of 36 adult SD rats were divided into 4 groups with 9 rats in each group by the random number table method.Two full-layer skin defect wounds of 2 cm×2 cm were made on the back of each rat.Normal saline was added to the wounds of the control group,and corresponding hydrogel was added to the wounds of the CS-L,CS-D,and CS-DL groups,respectively,and then bandaged and fixed.The wound healing was observed regularly after operation.Hematoxylin-eosin staining was performed at 3,10,and 21 days after operation.The samples were collected 10 days after operation and M2 macrophage immunofluorescence staining was performed. RESULTS AND CONCLUSION:(1)In vitro experiments:Under scanning electron microscopy,the three kinds of hydrogels exhibited obvious interpenetrating network structures with pore sizes ranging from 70-200 μm.The three kinds of hydrogels have good swelling performance,degradation performance,self-healing performance,and suitable mechanical strength.The three kinds of hydrogels had good cytocompatibility and hemocompatibility and could promote the migration of fibroblasts.All three kinds of hydrogels had the ability to promote the polarization of macrophages,and CS-D hydrogels had the strongest ability to promote the polarization of macrophages.CS-L hydrogel could significantly promote the production of NO in macrophages.(2)In vivo experiment:3 and 10 days after operation,the wound healing rate in the CS-L and CS-D groups was higher than that in the control group(P<0.05).After 21 days,the wound healing rate of the three hydrogel groups was higher than that of the control group.Hematoxylin-eosin staining displayed that a large number of inflammatory cells were infiltrated in the wound tissue of rats in all groups,accompanied by neovessels and fibroblasts 3 days after operation.10 days after operation,there was still more inflammatory cell infiltration in the wound of the control group,and the inflammation of the other three groups was improved,especially the decrease of inflammatory cells in the CS-D group was more obvious.21 days after operation,the wound epithelium of each group was well repaired,and there was basically no inflammatory cell infiltration in the CS-L and CS-D groups,while there was still a small amount of inflammatory cell infiltration in the control group.Immunofluorescence staining revealed that the number of M2-type macrophages in the CS-D group was higher than that in the other three groups(P<0.05).(3)The results conclude that chitosan hydrogels modified by different configurations of arginine can promote wound healing through different mechanisms.

Objective:To study the effects of metformin on marginal bone resorption of implants in patients with type 2 diabetes melli-tus(T2DM)and exercise habit.Methods:63 cases with 73 implants were included.Among them,there were 41 cases(47 implants)without T2DM in group N,10 cases(13 implants)with T2DM and without exercise habit in group M,12 cases(12 implants)with T2DM and exercise habit in the MR group.The patients were followed up at 6 months,1 and 2 years after implantation.The marginal bone loss(MBL).Implantation success rate and peri-implantitis incidence rate were compared among the groups.Results:The bone resorption of the proximal and median margins of the long-term bone level of the implants in the N and MR groups were significantly lower than that in the M group(P=0.001 and P=0.000 5,respectively).The implant success rates of group N,MR and M were 95.74％,100％and 76.92％,respectively.The incidence of peri-implantitis of the three groups was 2.13％,0 and 15.38％,respec-tively.Conclusion:Metformin is more effective in the improvement of the long-term marginal bone resorption of implants,increase the success rate of implants,and reduce the incidence of peri-implantitis in patients with T2DM and exercise habit in the mandibular first molar area.

Objective:To establish the ultra high performance liquid chromatography (UPLC) fingerprints of Mume flos at different flowering stages; To provide reference for the quality research of Mume flos.Methods:The fingerprints of Mume flos were established by UPLC method, and the common peaks were identified by high performance liquid chromatography high resolution mass spectrometry (LC-MS). Chemometrics analysis was carried out with the fingerprints' common peak area of plum blossom at different flowering stages as a variable. Semiquantitative analysis of changes in flavonoids and phenolic acids in Mume flos at different flowering stages was conduct using peak area calculation method.Results:Totally 31 common peaks were identified in the fingerprints of plum blossom medicinal materials at different flowering stages and 9 components were identified. Clustering analysis (HCA) and principal component analysis (PCA) both classified plum blossom medicinal herbs at different flowering stages into three categories. Among them, there were significant differences between the groups at the bud stage, blooming period, and final flowering period, while the differences between the groups at blooming period and final flowering period were relatively small. The orthogonal partial least squares discriminant analysis (OPLS-DA) screened 16 different components with VIP>1.0. The contents of phenolic acids in different flowering stages were as follows: bud stage>blooming period>final flowering period, while the contents of flavonoids were as follows: blooming period>final flowering period>bud stage.Conclusions:This method is simple and reliable, and can provide reference for the quality evaluation of plum blossom medicinal materials at different flowering stages.

Family resilience refers to the positive response of families in the face of adversity in order to promote family recovery and maintain family function and structural stability.This paper combs the related researches on family resilience in the patients with malignant tumors at home and abroad,introduces the con-cept of family resilience,evaluation tools,research status quo and influencing factors,and provides the corre-sponding intervention strategy for family resilience in the patients with malignant tumors in order to provide reference for optimizing more comprehensive and more effective service of the managers or medical institu-tions.

Objective:To comprehensively evaluated the quality of Sargentodoxae Caulis from different habitats with a combination of indexes and characteristic chromatogram method from Chinese Pharmcopoeia (Edition 2020). Methods:The contents of water content, total ash, ethanolic extract, sulfur dioxide residue, heavy metals and harmful elements, total phenols, chlorogenic acid, salidroside and characteristic chromatogram of 17 batches of Sargentodoxae Caulis were determined. The quality of Sargentodoxae Caulis was comprehensively evaluated by combining chemical pattern recognition method. Results:The water content, total ash content, extracts, and content determination of 17 batches of Sargentodoxae Caulis from different habitats complyed with the provisions of the Chinese Pharmcopoeia (Edition 2020). There were differences in the contents of extracts, chlorogenic acid, and salidroside, among which the content of Anhui origin was higher. A total of 8 common peaks were identified from the 17 batches samples. Conclusion:Comprehensive evaluation of multiple indicators can demonstrate the quality of Sargentodoxae Caulis more correctly, and shows that the quality of Sargentodoxae Caulis from different habitats is different. The quality of Sargentodoxae Caulis from Anhui is better than that from other habitats.

Objective:To evaluate the effect of electroacupuncture (EA) on programmed cell death ligand-1 (PD-L1)/programmed cell death receptor-1 (PD-1)/Src-homology region two domain-containing phosphatase-1 (SHP-1) signaling pathway in the dorsal root ganglia (DRG) of rats with acute postoperative pain.Methods:Thirty-nine SPF male Sprague-Dawley rats, weighing 220-250 g, aged 6-8 weeks, were divided into 3 groups ( n=13 each) using a random number table method: control group (group C), abdominal surgery group (group S) and abdominal surgery+ EA group (group S+ EA). Group S and group S+ EA underwent abdominal surgery under isoflurane anesthesia. In S+ EA group, both Zusanli and Sanyinjiao acupoints were selected and stimulated for 30 min with a frequency of 10 Hz continuous wave and a current of 1 mA starting from the end of operation and 2 h after operation. Seven rats were selected from each group for measurement of the mechanical paw withdrawal threshold (MWT), abdominal contraction threshold (ACT), thermal paw withdrawal latency (TWL) and cold paw withdrawal latency (CWL) at 1 day before developing the model (T 0) and 3, 5, 7, 9, 11 and 24 h after developing the model (T 1-6). Six rats in each group were sacrificed at 5 h after the model was prepared, and T 12-L 4 DRG was removed for determination of the expression of interleukin-6 (IL-6), PD-L1, PD-1 and SHP-1 (by Western blot) and expression of PD-L1 in various neurons (by immunofluorescence). Results:There was no significant difference in TWL and CWL between the three groups at different time points ( P>0.05). Compared with group C, MWT at T 1-5 and ACT at T 1-6 were significantly decreased, and the expression of IL-6 in DRG was up-regulated, and the expression of PD-L1, PD-1 and SHP-1 in DRG was down-regulated in group S ( P<0.05). Compared with group S, MWT and ACT were significantly increased at T 1, 2, the expression of IL-6 in DRG was down-regulated, and the expression of PD-L1, PD-1 and SHP-1 in DRG was up-regulated in group S+ EA ( P<0.05). The results of immunofluorescence showed that PD-L1 was expressed on both small diameter neurons (CGRP + neurons and IB4 + neurons) and large diameter neurons (NF200 + neurons) and mainly on CGRP + neurons and IB4 + neurons. There was no significant difference in the expression of PD-L1 in various DRG neurons among the three groups ( P>0.05). Conclusions:The mechanism by which EA relieves acute postoperative pain may be related to activation of the PD-L1/PD-1-SHP-1 signaling pathway in the DRG of rats.

Natural extracellular vesicles (EVs) play important roles in many life processes such as in the intermolecular transfer of substances and genetic information exchanges. Investigating the origins and working mechanisms of natural EVs may provide an understanding of life activities, especially regarding the occurrence and development of diseases. Additionally, due to their vesicular structure, EVs (in small molecules, nucleic acids, proteins, etc.) could act as efficient drug-delivery carriers. Herein, we describe the sources and biological functions of various EVs, summarize the roles of EVs in disease diagnosis and treatment, and review the application of EVs as drug-delivery carriers. We also assess the challenges and perspectives of EVs in biomedical applications.

During the epidemic of coronavirus disease 2019 (COVID-19), the infection of the elderly population will bring great challenges to clinical diagnosis and treatment, outcome and management.Combined with the characteristics of anesthesia and the pathophysiological characteristics of COVID-19 on lung function impairment in elderly patients, Chinese Society of Anesthesiology formulated the " Recommendations for anesthesia management and infection control in elderly patients with COVID-19″. This recommendation expounds preoperative visit and infection control, anesthesia management protocol, anesthesia monitoring, anesthesia induction/endotracheal intubation, anesthesia maintenance and infection control, intraoperative lung protection strategy, anti-stress and anti-inflammatory management, hemodynamic optimization, infection control during emergence from anesthesia, and postoperative analgesia in elderly patients with COVID-19, and provides the reference for the safe and effective implementation of anesthesia management in elderly patients during the prevention and control of COVID-19 epidemic.

Objective:To investigate the changes in liver function and peripheral regulatory lymphocytes before and after treatment in patients with occupational medicamentosa-like dermatitis due to trichloroethylene (OMDT) .Methods:In December 2019, 16 patients with OMDT (8 patients with erythema multiforme and 8 with erythema multiforme major) who were admitted from February 2017 to February 2019 were enrolled as subjects. Liver function parameters and percentages of peripheral regulatory lymphocytes were measured before and after treatment, and the changes in liver function and peripheral regulatory T and B lymphocytes and their correlation were analyzed.Results:Before treatment, compared with the healthy control group, the experimental group had significantly higher levels of alanine aminotransferase (ALT) , aspartate aminotransferase (AST) , total bilirubin (TBIL) , direct bilirubin (DBIL) and gamma-glutamyl transpeptidase (GGT) and significantly lower levels of total protein (TP) , albumin (ALB) and cholinesterase (CHE) ( P<0.05) . Compared with the healthy control group, the experimental group had significantly lower percentages of lymphocytes, CD4 + T cells, CD4 +CD25 + Tregs, CD19 +CD24 +CD27 + Bregs and CD4 +/CD8 + ratio, as well as a significantly higher percentage of CD8 + T cells ( P<0.05) . Before treatment, the levels of ALT, AST, GGT and DBIL were negatively correlated with the percentages of CD4 +CD25 + Tregs, CD19 +CD24 +CD27 + Bregs, CD4 + T cells and CD4 +/CD8 + ratio ( r=-0.386 to -0.809, P<0.05) and was positively correlated with the percentage of CD8 + T cells (except DBIL) ( r=0.503-0.568, P<0.05) . The levels of TP and ALB were positively correlated with the percentages of CD4 +CD25 + Tregs, CD19 +CD24 +CD27 +Bregs and CD4 + T cells ( r= 0.351-0.784, P<0.05) , ALB was negatively correlated with the percentage of CD8 + T cells ( r=-0.315, P<0.05) . CHE was positively correlated with the percentages of CD4 +CD25 + Tregs, CD19 +CD24 +CD27 +Bregs and CD4 +/CD8 + ratio ( r=0.390-0.527, P<0.05) . Conclusion:Immune dysfunction is observed in patients with OMDT, which may be caused by the imbalance of regulatory lymphocytes. And liver injury may be associated with the increase of CD8 + T cells and the reductions of percentages of CD4 + T cells, CD4 +CD25 + Tregs, CD19 +CD24 +CD27 +Bregs and CD4 +/CD8 + ratio.

Objective:To investigate the changes in liver function and peripheral regulatory lymphocytes before and after treatment in patients with occupational medicamentosa-like dermatitis due to trichloroethylene (OMDT) .Methods:In December 2019, 16 patients with OMDT (8 patients with erythema multiforme and 8 with erythema multiforme major) who were admitted from February 2017 to February 2019 were enrolled as subjects. Liver function parameters and percentages of peripheral regulatory lymphocytes were measured before and after treatment, and the changes in liver function and peripheral regulatory T and B lymphocytes and their correlation were analyzed.Results:Before treatment, compared with the healthy control group, the experimental group had significantly higher levels of alanine aminotransferase (ALT) , aspartate aminotransferase (AST) , total bilirubin (TBIL) , direct bilirubin (DBIL) and gamma-glutamyl transpeptidase (GGT) and significantly lower levels of total protein (TP) , albumin (ALB) and cholinesterase (CHE) ( P<0.05) . Compared with the healthy control group, the experimental group had significantly lower percentages of lymphocytes, CD4 + T cells, CD4 +CD25 + Tregs, CD19 +CD24 +CD27 + Bregs and CD4 +/CD8 + ratio, as well as a significantly higher percentage of CD8 + T cells ( P<0.05) . Before treatment, the levels of ALT, AST, GGT and DBIL were negatively correlated with the percentages of CD4 +CD25 + Tregs, CD19 +CD24 +CD27 + Bregs, CD4 + T cells and CD4 +/CD8 + ratio ( r=-0.386 to -0.809, P<0.05) and was positively correlated with the percentage of CD8 + T cells (except DBIL) ( r=0.503-0.568, P<0.05) . The levels of TP and ALB were positively correlated with the percentages of CD4 +CD25 + Tregs, CD19 +CD24 +CD27 +Bregs and CD4 + T cells ( r= 0.351-0.784, P<0.05) , ALB was negatively correlated with the percentage of CD8 + T cells ( r=-0.315, P<0.05) . CHE was positively correlated with the percentages of CD4 +CD25 + Tregs, CD19 +CD24 +CD27 +Bregs and CD4 +/CD8 + ratio ( r=0.390-0.527, P<0.05) . Conclusion:Immune dysfunction is observed in patients with OMDT, which may be caused by the imbalance of regulatory lymphocytes. And liver injury may be associated with the increase of CD8 + T cells and the reductions of percentages of CD4 + T cells, CD4 +CD25 + Tregs, CD19 +CD24 +CD27 +Bregs and CD4 +/CD8 + ratio.