Objective To investigate the changes in blood microbiota in patients with high altitude polycythemia(HAPC)and the correlation with the risk of HAPC.Methods A cross-sectional trial was carried out among 41 HAPC patients(HAPC group)and 41 healthy plateau individuals(control group)who took physical examination in the Health Management Department of No.953 Hospital of PLA Army in 2021.High-throughput sequencing technology was used to detect the V3-V4 variable region of the 16S ribosomal RNA(16S rRNA)gene in the blood smaples,and the composition and difference of the blood microbiota were compared and analyzed between the 2 groups.Results All the participants were male and Han people,and there were no significant differences in baseline data such as age,body mass index and plateau migration time between the 2 groups(P＞0.05).The α-diversity of blood microbiota in the HAPC group,including the Simpson index(0.931±0.005 vs 0.907±0.008,P＜0.05),Goods Coverage index(0.998±0.001 vs 0.997±0.001,P＜0.001)and Pielou index(0.597±0.011 vs 0.567±0.009,P＜0.05)were significantly higher than those in the control group.Meanwhile,obvious difference was observed in the β diversity between the 2 groups(P＜0.01).The relative abundance analysis of bacteria showed that Pelomonas(0.046±0.004 vs 0.033±0.003,P＜0.05),Azospirillum(0.046±0.006 vs 0.021±0.003,P＜0.01),Acidovorax(0.032± 0.003 vs 0.019±0.002,Azospirillum(0.046±0.006 vs 0.021±0.003,P＜0.01)and Acidovorax(0.032± 0.003 vs 0.019±0.002,P＜0.05)were statistically higher in the HAPC group than the control group.LEfSe analysis showed that the characteristic blood microbiota of the HAPC group were α-Proteobacteria,and those of control group were Trichospiridae.Conclusion Significant changes are found in diversity,relative abundance and characteristic bacteria of the blood microbiota between the HAPC patients and healthy people at the high altitude,which might be closely associated with the occurrence and development of HAPC.

Objective:To explore high-risk sexual behaviors of HIV/AIDS and related factors in young students in Guangzhou.Methods:A cross-sectional survey was conducted in 5 different types of Guangzhou colleges by convenience sampling with minimum number of classes per grade and 600 samples per school from September to November 2021. The R 4.2.2 software was used to consolidate databases. Simultaneously, a logistic regression model and a decision tree algorithm model, stratifying by whether sexual behaviors had occurred before, were constructed. In each layer, the prediction performance of the two models was evaluated through area under receiver operating characteristic and the confusion matrix, and then the model with high prediction performance was retained.Results:A total of 7 346 students were surveyed. The proportion of the respondents reporting sexual experience were 9.08% (667/7 346), in whom 26.24% (175/667) had risky sexual activity in the past year. The decision tree algorithm model performs well in predicting whether high-risk sexual behaviors have occurred in the past year. When the complexity parameter value is 0.018, and nsplit reaches 4, which means there are 5 leaf nodes in the model, the cross error of the tree will be the smallest. The first best grouping variable in the decision tree was whether to use condoms throughout the first sexual behavior. If condoms were used at their sexual debut, but homosexual practices have occurred in the past year, the probability of risky sexual behavior will increase. If homosexual practices have not occurred in the past year, but the age of sexual debut was below 18 years old while the period of HIV education was after high school, the probability of risk sexual behavior will also increase.Conclusions:AIDS-related risky behaviors of young students still deserved attention. The experience of sexual debut and whether AIDS-related health education has been received before the sexual debut were significant predictors for the occurrence of high-risk sexual behavior. The decision tree algorithm model has particular applicability for predicting and screening potential risk populations.

Inhibiting the death receptor 3(DR3)signaling pathway in group 3 innate lymphoid cells(ILC3s)pre-sents a promising approach for promoting mucosal repair in individuals with ulcerative colitis(UC).Paeoniflorin,a prominent component of Paeonia lactiflora Pall.,has demonstrated the ability to restore barrier function in UC mice,but the precise mechanism remains unclear.In this study,we aimed to delve into whether paeoniflorin may promote intestinal mucosal repair in chronic colitis by inhibiting DR3 signaling in ILC3s.C57BL/6 mice were subjected to random allocation into 7 distinct groups,namely the control group,the 2％dextran sodium sulfate(DSS)group,the paeoniflorin groups(25,50,and 100 mg/kg),the anti-tumor necrosis factor-like ligand 1A(anti-TL1A)antibody group,and the IgG group.We detected the expression of DR3 signaling pathway proteins and the proportion of ILC3s in the mouse colon using Western blot and flow cytometry,respectively.Meanwhile,DR3-overexpressing MNK-3 cells and 2％ DSS-induced Rag1-/-mice were used for verification.The results showed that paeoniflorin alleviated DSS-induced chronic colitis and repaired the intestinal mucosal barrier.Simultaneously,paeoniflorin inhibited the DR3 signaling pathway in ILC3s and regulated the content of cytokines(interleukin-17A,granulocyte-macrophage colony stimulating factor,and interleukin-22).Alternatively,paeoniflorin directly inhibited the DR3 signaling pathway in ILC3s to repair mucosal damage indepen-dently of the adaptive immune system.We additionally confirmed that paeoniflorin-conditioned me-dium(CM)restored the expression of tight junctions in Caco-2 cells via coculture.In conclusion,paeoniflorin ameliorates chronic colitis by enhancing the intestinal barrier in an ILC3-dependent manner,and its mechanism is associated with the inhibition of the DR3 signaling pathway.

Uncontrolled hypertension in the perioperative period may affect the hemodynamic stability of patients during surgery and thus affect the prognosis of patients.This increases the risk of other complications and death.For hypertensive patients undergoing surgery,it is necessary to weigh the pros and cons,and choose appropriate antihypertensive drugs to reduce the incidence of perioperative adverse events.There is no unified conclusion on perioperative blood pressure management in China.This paper systematically reviewed the perioperative blood pressure control objectives and drug use programs,including non-cardiac surgery,cardiac surgery,pregnancy,and pheochromocytoma.It provided a reference for the perioperative management of hypertensive patients.

High Altitude Military Hygiene is the professional core course of high-altitude medicine, which is significant to the cultivation of military medical talents urgently needed by plateau troops. Under the background of "golden course" construction and army curriculum reform, aiming at the problems such as outdated content of course materials, single teaching mode and insufficient capacity of practical courses, we actively explored the effective path of "golden course" construction, including the renovation of the curriculum-construction concept, the optimization and reorganization of the teaching content, the expansion of case teaching and equipment teaching methods, and the implementation of curriculum ideological and political education and examination reforms. The reform has further improved the learning effect of students and the level of curriculum construction, and also provided beneficial reference for the construction of similar courses in military colleges and universities.

Objective:To evaluate the value of radiomics based on contrast-enhanced spectral mammography (CESM) of internal and peripheral regions combined with clinical factors in predicting benign and malignant breast lesions of breast imaging reporting and data system category 4 (BI-RADS 4).Methods:A retrospective analysis was performed on the clinical and imaging data of patients with breast lesions who were treated in Yantai Yuhuangding Hospital (Center 1) Affiliated to Qingdao University from July 2017 to July 2020 and in Fudan University Cancer Hospital (Center 2) from June 2019 to July 2020. Center 1 included 835 patients, all female, aged 17-80 (49±12) years, divided into training set (667 cases) and test set (168 cases) according to the "train-test-split" function in Python software at a ratio of 8∶2; and 49 patients were included from Center 2 as external validation set, all female, aged 34-70 (51±8) years. The radiomics features were extracted from the intralesional region (ITR), the perilesional regions of 5, 10 mm (PTR 5 mm, PTR10 mm) and the intra-and perilesional regions of 5, 10 mm (IPTR 5 mm, IPTR 10 mm) and were selected by variance filtering, SelectKBest algorithm, and least absolute shrinkage and selection operator. Then five radiomics signatures were constructed including ITR signature, PTR 5 mm signature, PTR 10 mm signature, IPTR 5 mm signature, IPTR 10 mm signature. In the training set, univariable and multivariable logistic regressions were used to construct nomograms by selecting radiomics signatures and clinical factors with significant difference between benign and malignant BI-RADS type 4 breast lesions. The efficacy of nomogram in predicting benign and malignant BI-RADS 4 breast lesions was evaluated by the receiver operating characteristic curve and area under the curve (AUC). Decision curve and calibration curve were used to evaluate the net benefit and calibration capability of the nomogram.Results:The nomogram included ITR signature, PTR 5 mm signature, PTR 10 mm signature, IPTR 5 mm signature, age, and BI-RADS category 4 subclassification for differentiating malignant and benign BI-RADS category 4 breast lesions and obtained AUCs of 0.94, 0.92, and 0.95 in the training set, test set, and external validation set, respectively. The calibration curve showed good agreement between the predicted probabilities and actual results and the decision curve indicated a good net benefit of the nomogram for predicting malignant BI-RADS 4 lesions in the training set, test set, and external validation set.Conclusion:The nomogram constructed from the radiomics features of the internal and surrounding regions of CESM breast lesions combined with clinical factors is attributed to differentiate benign from malignant BI-RADS category 4 breast lesions.

Cyclodipeptide (CDP) composed of two amino acids is the simplest cyclic peptide. These two amino acids form a typical diketopiperazine (DKP) ring by linking each other with peptide bonds. This characteristic stable ring skeleton is the foundation of CDP to display extensive and excellent bioactivities, which is beneficial for CDPs' pharmaceutical research and development. The natural CDP products are well isolated from actinomycetes. These bacteria can synthesize DKP backbones with nonribosomal peptide synthetase (NRPS) or cyclodipeptide synthase (CDPS). Moreover, actinomycetes could produce a variety of CDPs through different enzymatic modification. The presence of these abundant and diversified catalysis indicates that actinomycetes are promising microbial resource for exploring CDPs. This review summarized the pathways for DKP backbones biosynthesis and their post-modification mechanism in actinomycetes. The aim of this review was to accelerate the genome mining of CDPs and their isolation, purification and structure identification, and to facilitate revealing the biosynthesis mechanism of novel CDPs as well as their synthetic biology design.
Actinobacteria/metabolism* ; Actinomyces/metabolism* ; Biological Products/metabolism* ; Bacteria/metabolism* ; Diketopiperazines/metabolism* ; Amino Acids

Objective:To investigate the effects and the possible mechanisms of Neiguan(PC6)and Gongsun(SP4)on the hypothalamic-pituitary-adrenal(HPA)axis in rats with functional dyspepsia(FD),thus to provide a theoretical basis for the clinical application of the Eight Confluent Points.Methods:Forty specific-pathogen-free Sprague-Dawley rats were divided into a blank group,a model group,an electroacupuncture(EA)group,and a Western medicine group by the random number table method,with 10 rats in each group.Rats in the blank group did not receive modeling or intervention.Rats in the other three groups were subjected to the FD with mood disorder model using the compound etiology modeling method.After the successful modeling,rats in the model group did not receive any interventions,rats in the Western medicine group received deanxit and mosaprid intervention,and those in the EA group received EA intervention on the ipsilateral Neiguan(PC6)and Gongsun(SP4)for 21 d.The sugar-water consumption rate was measured before the experiment and before and after interventions to assess the emotional status.The gastric emptying rate was measured after interventions to assess the gastrointestinal dynamics.The expression levels of hypothalamic corticotropin-releasing hormone(CRH),pituitary adrenocorticotropic hormone(ACTH),and adrenal corticosterone(CORT)were measured by enzyme-linked immunosorbent assay.Results:Compared with the blank group,the sugar-water consumption rate and the gastric emptying rate were decreased(P<0.01),and the hypothalamic CRH,pituitary ACTH,and adrenal CORT expression levels were increased(P<0.01)in the model group.Compared with the model group,the sugar-water consumption rate and the gastric emptying rate were significantly increased(P<0.01),while the expression levels of hypothalamic CRH,pituitary ACTH,and adrenal CORT were significantly decreased(P<0.01)in the EA group and the Western medicine group.The differences between the EA group and the Western medicine group were not statistically significant(P>0.05).Conclusion:The Eight Confluent Points Neiguan(PC6)and Gongsun(SP4)can improve the mood and gastrointestinal dynamics in FD rats,which may be achieved by down-regulating the hypothalamic CRH,pituitary ACTH,and adrenal CORT,as well as by correcting the HPA axis hyperfunction.

Objective:To investigate the risk perception for risky behavior of HIV/AIDS infection among young students and to analyze the related influencing factors.Methods:A cross-sectional survey was conducted in 5 different types of Guangzhou colleges from September to November 2021, in which convenience sampling and a minimum number of classes per grade and 600 samples per school were used according to the national unity program. Disordered multi-classification logistic regression was used to construct a risk perception model and analyze influencing factors in different risk perception levels.Results:A total of 7 346 young students were surveyed, and most rated themselves at low risk of HIV/AIDS infections (90.58%, 6 654/7 346). A total of 89.10% (6 545/7 346) of subjects' perception of their HIV/AIDS infection risk was consistent with their risk behavior, while 10.90% (801/7 346) was inconsistent. Among those inconsistent subjects, 19.10% (153/801) showed underestimating their risk , while 80.90% (648/801) seen overestimating their risk. Disordered multi-classification logistic regression analysis showed that, after controlling for other factors, compared with the non-sexual group, respondents whose first sex age under 18 had a higher rate of underestimating their risk of infection ( OR=129.39, 95% CI: 73.28-228.48), as well as a higher rate of overestimated their risk of infection ( OR=1.76, 95% CI: 1.04-2.99). First sexual intercourse at age 18 or older was a risk factor for underestimating risk ( OR=70.56, 95% CI: 42.72-116.53), but was not statistically associated with overestimating risk. Being female, other school type, non-heterosexual orientation, and self-rated HIV-related knowledge as fair or no knowledge were risk factors for overestimating risk but were not statistically associated with underestimating risk. Conclusions:Overall, young students in universities of Guangzhou have a good risk perception of HIV/AIDS infection. Individual factors, education factors and sexual experience will influence students' risk perception of HIV/AIDS infection. Raising the awareness rate of HIV/AIDS knowledge and delaying the age of first sexual intercourse will improve the risk perception ability of young students.

Objective To investigate the diagnostic accuracy of FibroScan-AST (FAST) score in patients with high-risk nonalcoholic steatohepatitis (NASH) with a nonalcoholic fatty liver disease (NAFLD) activity score of ≥4 and significant liver fibrosis (F ≥2), along with comparison with other serological models. Methods A total of 84 consecutively admitted patients hospitalized in Ruijin Hospital from January 2015 to December 2020 and biopsy-confirmed NAFLD/NASH were included in this study, and FibroScan (liver stiffness measurement and controlled attenuation parameter) and blood biochemical tests were performed at one week before and after liver biopsy. A Kruskal-Wallis H analysis of variance was used for comparison between multiple groups, and Spearman's correlation coefficient was used to analyze the correlation between variables. The receiver operating characteristic (ROC) curve was plotted with pathological results as the "gold standard", and the area under the ROC curve (AUC) was calculated. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and classification accuracy were calculated based on the cut-off values determined by previous studies. In subgroup analysis, the patients were divided into subgroups based on different clinical indices to evaluate the diagnostic accuracy of each model, which was expressed as AUC (95% confidence interval [ CI ]). Results Among the 84 patients, 43 had high-risk NASH. The FAST score was 0.54(0.04-0.93) for all patients, and the FAST score for liver fibrosis stages F0-F4 was 0.26(0.06-0.73), 0.48(0.04-0.82), 0.61(0.13-0.75), 0.64(0.09-0.93), and 0.82(0.75-0.89), respectively, with a significant difference between stages ( H =23.360, P < 0.001). FAST score was positively correlated with liver fibrosis stage ( r =0.491, P < 0.001). NAFLD fibrosis score (NFS), fibrosis-4 (FIB-4), and aspartate aminotransferase-to-platelet ratio index were positively correlated with liver fibrosis stage ( r =0.230, 0.346, and 0.281, all P < 0.05), with a weaker correlation than FAST score. FAST score had an AUC of 0.725 (95% CI : 0.617-0.834, P < 0.001) in evaluating high-risk NASH. According to the low cut-off value determined by previous studies, FAST score ≤0.35 excluded high-risk NASH in 21 patients (25%) with an NPV of 71%; according to the high cut-off value, FAST score ≥0.67 helped to make a confirmed diagnosis of high-risk NASH in 19 patients (22.6%) with a PPV of 74%. NFS and FIB-4 had an AUC of 0.633(95% CI : 0.513-0.753) and 0.686(95% CI : 0.570-0.803), respectively, in the diagnosis of high-risk NASH ( P < 0.05). Conclusion FAST score can accurately determine the presence or absence of high-risk NASH in NAFLD patients with or without metabolic risk factors, and selection of appropriate cut-off values can help some patients avoid liver biopsy.