Glaucocalyxin A （GLA） is a natural diterpenoid extracted from Isodon amethystoides belonging to Labiatae. Modern pharmacological research has shown that GLA has anti-inflammatory， anti-tumor， anti-fibrotic， osteoporosis-ameliorating， and cardiovascular system-protecting activities and good biosafety. However， the low content in plants， poor solubility， high metabolic rate， and low bioavailability limit the application of GLA. To address these issues， researchers have studied the total synthesis， structural modification， and nanomedicine development of GLA. By reviewing the available studies about GLA in the past five years， we summarize the research progress in the total synthesis， pharmacological activities and mechanisms， and in vivo metabolic transformation， aiming to provide a theoretical basis for clarifying the specific mechanisms underlying the pharmacological activities of GLA and for further research， development， and clinical applications of GLA.

【Objective】 To explore the effects of perceived risk of COVID-19 of college students on their anxiety and depression, as well as the roles of attention to negative information and perceived social support, so as to provide theoretical basis for colleges and universities to formulate corresponding intervention measures. 【Methods】 By the convenience sampling method, totally 1 404 college students from Shaanxi and Henan provinces were investigated online by using General Information Questionnaire, Perceived Risk of COVID-19 Pandemic Scale, Attention to Negative Information Scale, Patient Health Questionnaire, Generalized Anxiety Disorder and Perceived Social Support Scale. SPSS 20.0 was used for data analysis, Pearson correlation method was used to explore the correlation between variables. The mediating effect of attention to negative information and the moderating effect of perceived social support were analyzed by PROCESS. 【Results】 The scores of anxiety and depression of the 1 404 college students included in the study were 4.03±4.48 and 6.21±5.41, respectively. The detection rate of anxiety symptom was 29.9%, and that of depression symptom was 44.4%. The risk perception of COVID-19 epidemic of the college students was positively correlated with attention to negative information (r=0.373, P<0.001), anxiety (r=0.227, P<0.001), and depression (r=0.226, P<0.001). Anxiety (r=0.553, P<0.001) and depression (r=0.497, P<0.001) were positively correlated with attention to negative information, while perceived social support was negatively correlated with the risk perception of the COVID-19 (r=-0.154, P<0.001), attention to negative information (r=-0.259, P<0.001), anxiety (r=-0.321, P<0.001) and depression (r=-0.278, P<0.001). The risk perception of COVID-19 affected the anxiety and depression of the students mainly through the mediating effect of attention to negative information. The total effect of risk perception of COVID-19 and anxiety was 0.227, and the mediating effect accounted for 80.18% of the total effect. The total effect of risk perception of COVID-19 and depression was 0.228, and the mediating effect accounted for 90.35% of the total effect. Perceived social support played a moderating role in the last half of this mediating model. 【Conclusion】 Risk perception of COVID-19 indirectly affects the occurrence of anxiety and depression in college students through attention to negative information, and perceived social support plays a moderating role in this mediating model. The findings suggest that when a risk event occurs, colleges and universities should pay attention to guiding students to adjust their attentional bias to external information, and give students enough care and support to improve their mental health.

【Objective】 To explore the relationship between chronic comorbidity and the physical and mental health of relatives of elderly people during the nursing home confinement, and to analyze the mediating effects of perceived stress and intolerance of uncertainty in this context. 【Methods】 A total of 568 family members of elderly people in nine elderly institutions in Shaanxi Province were selected. The survey included the short version of the Perceived Stress Scale, Intolerance of Uncertainty Scale, and The World Health Organization-5 Well-being Index. The data were analyzed with Stata for correlation and mediation effects. 【Results】 ① The comorbidities of chronic diseases was positively correlated with the perceived stress (r=0.16, P<0.001) and intolerance of uncertainty (r=0.11, P=0.006) of the family members, but negatively correlated with the physical and mental health of the family members (r=-0.13, P=0.002). ② The mediating effect of perceived stress between chronic disease co-morbidity and physical and mental health of family members in older adults was -0.023, accounting for 18.8% of the total effect; the mediating effect of intolerance of uncertainty between chronic disease co-morbidity and physical and mental health of family members in older adults was -0.041, accounting for 33.5% of the total effect. 【Conclusion】 During closed management in a nursing facility, the physical and mental health of family members of older adults with chronic co-morbidities is poorer than that of family members of non-chronic co-morbidities. And it can lead to a decline in physical and mental health of family members through increased perceived stress and intolerance of uncertainty.

Objective:To explore the effect of key amino acid mutations of 3D protein in enterovirus 71 on viral proliferation, and infer the mechanism of mutation affecting viral proliferation according to the tertiary structure model of 3D protein.Methods:The proliferation characteristics of the mutant strain that was constructed by site-directed mutagenesis and reverse genetics using the pMD19T-SDLY107-EGFP constructed from the fatal strain SDLY107 as a template were measured. Meanwhile the tertiary structure of the 3D protein was predicted, and then the possible mechanism of the mutation affecting the proliferation ability of the virus was speculated according to the functional characteristics of the domain of the 3D protein.Results:Two mutant viruses, eGFP-EV-A71 (S37N) and eGFP-EV-A71 (R142K), were successfully constructed by double enzyme digestion and viral gene sequencing. The proliferation rate of the two mutant strains in RD cells was significantly lower than that of the parent strains. The 3D protein tertiary structure prediction model showed that the 3D protein consisted of three domains: "Finger" , "thumb" and "Palm" , constituting a cupped right-handed structure. S37N and R142K are located in the "thumb" domain and " finger" domain, respectively. The "thumb" and "finger" domains have important effects on the activity of 3D polymerase and the stability of protein.Conclusions:Mutations at S37N and R142K sites of EV71 3D protein decrease the replication ability of EV71, and these two mutations may affect the proliferation of EV71 virus by changing the 3D protein polymerase activity and the interactions between multiple domains.

Objective:To construct and rescue enhanced green fluorescent protein(EGFP)-labeled EGFP-EV-A71 recombinant virus.Methods:pMD19T-SDLY107 full-length plasmid was used as a template, and 2A protease recognition sequence was added to the 5′end of the structural protein VP4. EGFP gene was amplified using the pEGFP-N1 plasmid as a template and inserted into the above-mentioned recombinant plasmid. RD cells were transfected to rescue the recombinant virus EGFP-EV-A71 after enzymatic digestion and in vitro transcription. The cell culture infectious dose 50% endpoint (CCID 50) was determined. Real-time fluorescent quantitative PCR (qRT-PCR) was used to detect the virus replication level at different time points, and the virus replication curve was drawn to compare the replication ability of the recombinant virus and the parent virus. Lactate dehydrogenase (LDH) and cell proliferation (CCK-8) experiments were used to determine the cell injury rate and survival rate of infected cells, respectively. Results:Recombinant EV-A71 infectious cDNA clones containing specific restriction sites and EGFP were successfully constructed. Typical cytopathic effect and green fluorescence was observed. The qRT-PCR replication curve showed that the recombinant virus had similar replication kinetics to the parent virus.Conclusions:EGFP-labeled enterovirus type 71 recombinant virus EGFP-EV-A71 was successfully rescued.

Objective:To study the basic characteristics and gene evolution of M segment of fever and thrombocytopenia syndrome virus (SFTSV)in China.Methods:The full sequence of M fragment of SFTSV strain isolated in China before June 25, 2020 was obtained from GenBank. The BioEdit software was used for multi-sequence alignment and MEGA5.0 software was used to construct the phylogenetic tree to compare the homology of SFTSV, which came from different types and sources.Results:M fragments of 203 SFTSV isolated in China was collected from GenBank database.. Among them, 185 strains were isolated from humans (91.1%), 11 strains were isolated from ticks(5.4%), and 5 strains were isolated from goat, mice and hedgehog (3.5%). Phylogenetic tree analysis showed that C2 genotype was dominant in China, accounting for 42.4% of total. The nucleotide sequence and amino acid sequence homology were 96.4%~100.0%, 94.5%~100.0%, respectively. The homology of human and animal isolates was very high. The nucleotide sequence and amino acid sequence homology were 92.5%~100.0% and 92.0%~100.0%, respectively.Conclusions:Phylogenetic tree analysis of SFTSV isolates in China based on the M fragment showed that C2 genotype was dominant, and there are multiple types of co-circulation. By comparing M and S-segment-based phylogenetic tree, it suggests that SFTSV may potential undergo adaptive conversion from C-type to J-type.

Objective: The present study aimed to investigate the effect of seasonal variation on neurotransmitter release in the hippocampus of normal rats and rats with pineal excision. Methods: Two time points, the summer and winter solstice, which are the longest and shortest days of the year, respectively, were selected. Male Sprague-Dawley rats that underwent a sham operation without pineal excision were included as a control group. The concentrations of 5-hydroxytryptamine (5-HT) and γ-aminobutyric acid (GABA) were determined by radioimmunoassays and enzyme-linked immunosorbent assays, respectively. Results: In the winter, the 5-HT and GABA levels in normal rats exhibited a significant difference compared with those in the operation group (P < .01). A difference was also noted in GABA levels be-tween the normal group and the sham operation group (P<.05). The concentrations of 5-HT and GABA in the hippocampal tissues of the normal group exhibited a seasonal rhythm consisting of elevation during the summer and reduction during the winter (P < .01), while the GABA levels in the sham operation group exhibited a significant difference, with elevation during the summer and reduction during the winter (P<.01). In the operation group, GABA showed the same trend (P<.01). Conclusion: The seasonal rhythm of neurotransmitter secretion by the hippocampus (5-HT and GABA) consisted of elevation during the summer and reduction during the winter. During the winter, the pineal gland exhibited a reverse regulatory effect on the secretion of 5-HT and GABA in the hippocampus, and it exhibited seasonal selectivity with regard to the regulation of 5-HT.

Objective To observe the influence of N-myc downstream-regulated gene 2 (NDRG2) on the growth and invasive ability of human colon cancer cell line SW620,and to explore its mechanism.Methods pcDNA3.1-NDRG2 and siRNA-NDRG2 were transfected transiently respectively into SW620 by Lipofectamine TM 2000,untreated cells as the control group.Western blotting was used to investigate the expression of NDRG2 and matrix metalloproteinase-2 (MMP-2).Matrigel invasion assay was used to study the invasive abilities of SW620 cells in all groups.The growth curve was determined through 3-(4,5-dimethyl-2-thiazoly)-2,5-diphenyl-2H-tetrazolium bromide method.Result After transfecting pcDNA3.1-NDRG2 into the SW620 cells,the protein level of NDRG2 increased and the expression of MMP-2 declined markedly.After transfecting siRNA-NDRG2 into the SW620 cells,the protein level of NDRG2 declined and the expression of MMP-2 increased markedly.In addition,compared with the control group (75.80 ± 4.82),the numbers of transmembrane cells in pcDNA3.1 group (56.20 ± 7.40) and in siRNA group (94.20 ± 9.23) were significantly different (t =13.102,P =0.000;t =11.820,P =0.000).The growth curve showed that:compared with the control group (0.67 ±0.01),the absorbance of the fifth day after transfection in pcDNA3.1 group (0.46 ±0.01) and in siRNA group (0.91 ± 0.02) were different significantly (t =9.561,P =0.000;t =10.922,P =0.000).Conclusion NDRG2 can reduce the invasion and proliferation ability of colon cancer cell SW620,and its mechanism may be related to the down-regulation of MMP-2 expression.

AIM:To study the protective effect of aqueous extract of 2-branched and 3-branched velvet antler on cisplatin (CDDP)-induced nephrotoxicity in mice .METHODS:The mouse model of renal injury was induced by intra-gastric administration of CDDP at the dose of 15 mg/kg.After treatment, kidney index (KI), serum creatinine (SCr), blood urea nitrogen (BUN), the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the content of malondialdehyde ( MDA) in the kidney were determined .The renal pathological changes were observed with HE staining.RESULTS:Aqueous extract of velvet antler at the tested dose markedly decreased BUN , SCr and the content of MDA, and elevated the activity of SOD and GSH-Px in the mice pretreated with CDDP ( P<0.05) .The pathological chan-ges of the renal tissues were improved obviously , and the injury of the epithelial cells of renal tubules was mitigated .The effect of the aqueous extract of 2-branched velvet antler on renal function and cisplatin-induced nephrotoxicity was better than that of 3-branched one at the same concentration .CONCLUSION: The aqueous extract of 2-branched and 3-branched velvet antler has a certain protective effect on cisplatin-induced nephrotoxicity , which may be associated with in-creasing the anti-oxidative capability of mouse renal tissue .

The aim of this study was to establish the methods to identify crystal form of dasatinib in tablets.X-ray powder diffraction(XRPD)and solid-state nuclear magnetic resonance(ssNMR)were used to analyze the crystal form of dasatinib in Sprycel? tablets and Yinishu? tablets.The results showed that monohydrate and anhydrate were identified in Sprycel? and Yinishu? tablets respectively;with no detectable anhydrate in Sprycel? tablets and no detectable monohydrate in Yinishu? tablets.The results of XRPD and ssNMR were consistent;and could be both applied in the crystal form identification of dasatinib in tablets.