Measurements of All-Particle Energy Spectrum and Mean Logarithmic Mass of Cosmic Rays from 0.3 to 30 PeV with LHAASO-KM2A.

We present the measurements of all-particle energy spectrum and mean logarithmic mass of cosmic rays in the energy range of 0.3-30 PeV using data collected from LHAASO-KM2A between September 2021 and December 2022, which is based on a nearly composition-independent energy reconstruction method, achieving unprecedented accuracy. Our analysis reveals the position of the knee at 3.67±0.05±0.15 PeV. Below the knee, the spectral index is found to be -2.7413±0.0004±0.0050, while above the knee, it is -3.128±0.005±0.027, with the sharpness of the transition measured with a statistical error of 2%. The mean logarithmic mass of cosmic rays is almost heavier than helium in the whole measured energy range. It decreases from 1.7 at 0.3 PeV to 1.3 at 3 PeV, representing a 24% decline following a power law with an index of -0.1200±0.0003±0.0341. This is equivalent to an increase in abundance of light components. Above the knee, the mean logarithmic mass exhibits a power law trend towards heavier components, which is reversal to the behavior observed in the all-particle energy spectrum. Additionally, the knee position and the change in power-law index are approximately the same. These findings suggest that the knee observed in the all-particle spectrum corresponds to the knee of the light component, rather than the medium-heavy components.

Stringent Tests of Lorentz Invariance Violation from LHAASO Observations of GRB 221009A.

On 9 October 2022, the Large High Altitude Air Shower Observatory (LHAASO) reported the observation of the very early TeV afterglow of the brightest-of-all-time gamma-ray burst 221009A, recording the highest photon statistics in the TeV band ever obtained from a gamma-ray burst. We use this unique observation to place stringent constraints on the energy dependence of the speed of light in vacuum, a manifestation of Lorentz invariance violation (LIV) predicted by some quantum gravity (QG) theories. Our results show that the 95% confidence level lower limits on the QG energy scales are E_{QG,1}>10 times the Planck energy E_{Pl} for the linear LIV effect, and E_{QG,2}>6×10^{-8}E_{Pl} for the quadratic LIV effect. Our limits on the quadratic LIV case improve previous best bounds by factors of 5-7.

Constraints on Ultraheavy Dark Matter Properties from Dwarf Spheroidal Galaxies with LHAASO Observations.

In this Letter we try to search for signals generated by ultraheavy dark matter at the Large High Altitude Air Shower Observatory (LHAASO) data. We look for possible γ rays by dark matter annihilation or decay from 16 dwarf spheroidal galaxies in the field of view of the LHAASO. Dwarf spheroidal galaxies are among the most promising targets for indirect detection of dark matter that have low fluxes of astrophysical γ-ray background while having large amount of dark matter. By analyzing more than 700 days of observational data at LHAASO, no significant dark matter signal from 1 TeV to 1 EeV is detected. Accordingly we derive the most stringent constraints on the ultraheavy dark matter annihilation cross section up to EeV. The constraints on the lifetime of dark matter in decay mode are also derived.

Clinical and ultrasound features of uterine perivascular epithelioid cell tumors: case series and literature review.

OBJECTIVE: To describe the clinical and ultrasonographic features of uterine perivascular epithelioid cell tumor (PEComa) using standardized terminology. METHODS: This was a retrospective analysis of patients with uterine PEComa diagnosed and confirmed by pathology and immunohistochemistry at West China Second University Hospital, Sichuan University, Sichuan, China, between January 2010 and September 2023. The Morphological Uterus Sonographic Assessment (MUSA) consensus and the International Endometrial Tumor Analysis (IETA) consensus were utilized for the standardized description of the sonographic characteristics of uterine PEComa. We summarized the clinical and ultrasound features of uterine PEComa in cases from our center and those found in a review of the literature conducted using PubMed from 1 January 2013 to 30 September 2023 (inclusive). RESULTS: Five patients, aged 33-57 (median, 52) years, with a total of six uterine PEComa lesions were included in our cohort. All cases had complete ultrasonographic and pathological images. None of the patients had a history of tuberous sclerosis complex. Two patients had malignant PEComa (one patient had two lesions) and three had benign PEComa, originating from the cervix, myometrium or uterine cavity. Patients presented with symptoms including increased vaginal discharge, vaginal bleeding and pelvic or abdominal pain. The three patients with benign PEComa underwent total hysterectomy and bilateral adnexectomy, tumor excision and conservative management, respectively, while both malignant cases underwent total hysterectomy and bilateral adnexectomy followed by chemotherapy. Regular follow-up (from 6 to 24 months) revealed recurrence in one case. Two lesions were misdiagnosed as uterine fibroids, two as cervical cancer, one as metastatic cervical cancer (with myometrial invasion) and one was indeterminate. Ultrasound examination showed that most lesions displayed regular round or ovoid shape (66.7%), uniform echoes (66.7%) and hypoechogenicity (66.7%), with one (16.7%) malignant PEComa showing cystic areas and one (16.7%) benign PEComa showing punctate calcifications. All lesions lacked shadowing and the majority showed moderate to abundant vascularity (color score of 3-4, 83.3%). The color score was 2-4 in the periphery in 100% of cases and internally in 83.3% of cases. The three benign PEComas showed similar characteristics in vascular distribution, with scattered internal vessels and peripheral vessels exhibiting a circular pattern. The literature search identified 11 articles describing the ultrasonographic appearance of 18 cases of uterine PEComa, with similar characteristics to those in our cohort. CONCLUSIONS: The sonographic features of uterine PEComa include a uniform or non-uniform hypoechogenic mass, typically round or ovoid with regular margins, occasionally containing cystic areas or calcifications, lacking shadowing and often showing moderate to abundant vascularity. Although the preoperative ultrasound diagnosis of uterine PEComa remains challenging, particularly given the non-specific nature of the sonographic characteristics described here, dispersed intratumoral vessels and a peripheral circular vascular distribution may serve as diagnostic clues for uterine PEComa, but more cases are needed for confirmation. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Age effect on the shared etiology of glycemic traits and serum lipids: evidence from a Chinese twin study.

PURPOSE: Diabetes and dyslipidemia are among the most common chronic diseases with increasing global disease burdens, and they frequently occur together. The study aimed to investigate differences in the heritability of glycemic traits and serum lipid indicators and differences in overlapping genetic and environmental influences between them across age groups. METHODS: This study included 1189 twin pairs from the Chinese National Twin Registry and divided them into three groups: aged ≤ 40, 41-50, and > 50 years old. Univariate and bivariate structural equation models (SEMs) were conducted on glycemic indicators and serum lipid indicators, including blood glucose (GLU), glycated hemoglobin A1c (HbA1c), total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C), in the total sample and three age groups. RESULTS: All phenotypes showed moderate to high heritability (0.37-0.64). The heritability of HbA1c demonstrated a downward trend with age (HbA1c: 0.50-0.79), while others remained relatively stable (GLU: 0.55-0.62, TC: 0.58-0.66, TG: 0.50-0.63, LDL-C: 0.24-0.58, HDL-C: 0.31-0.57). The bivariate SEMs demonstrated that GLU and HbA1c were correlated with each serum lipid indicator (0.10-0.17), except HDL-C. Except for HbA1c and LDL-C, as well as HbA1c and HDL-C, differences in genetic correlations underlying glycemic traits and serum lipids between age groups were observed, with the youngest group showing a significantly higher genetic correlation than the oldest group. CONCLUSION: Across the whole adulthood, genetic influences were consistently important for GLU, TC, TG, LDL-C and HDL-C, and age may affect the shared genetic influences between glycemic traits and serum lipids. Further studies are needed to elucidate the role of age in the interactions of genes related to glycemic traits and serum lipids.

Association between workplace health promotion service utilisation and depressive symptoms among workers: a nationwide survey.

OBJECTIVES: Workplace-related factors are associated with the risk of depression. Despite implementation of workplace health promotion (WHP) programmes in China to promote the physical and mental well-being of workers, the relationship between WHP and depression has received limited attention. This study investigated the association between WHP service utilisation and depressive symptoms among workers. STUDY DESIGN: This was a cross-sectional survey. METHODS: A researcher-designed questionnaire was used to collect information on socio-demographic and occupational characteristics, WHP service utilisation, and mental health status. The Lasso method was used for variable selection to achieve dimension reduction, and logistic regression was used to assess the association between WHP service utilisation and depressive symptoms. RESULTS: The analysis included 11,710 workers, of whom 17.0% had depressive symptoms. Lasso regression resulted in 6 of 18 WHP services showing significant negative associations with depressive symptoms, including occupational safety training, mental health services, health check-ups, sports activities, fitness rooms, and healthy canteens. The logistic regression results showed that, after adjusting for sociodemographic and occupational factors, utilisation of these six services was associated with a decreased likelihood of depressive symptoms. The adjusted odds ratio (aOR) was 0.84 (95% confidence interval [CI]: 0.73-0.96) for occupational safety training, aOR: 0.82 (95% CI: 0.68-0.99) for mental health services, aOR: 0.80 (95% CI: 0.71-0.90) for health check-ups, aOR: 0.68 (95% CI: 0.57-0.80) for sports activities, aOR: 0.59 (95% CI: 0.47-0.74) for fitness rooms and aOR: 0.72 (95% CI: 0.59-0.87) for healthy canteens. CONCLUSIONS: Utilisation of WHP services was associated with a lower prevalence of depressive symptoms. Implementation of WHP services and the provision of a supportive workplace environment should be prioritised to benefit the mental health of workers.

[The 504th case: Multiple lymph node enlargement, renal insufficiency, blindness, and white matter lesions of the brain].

A 65-year-old male patient was admitted for recurrent lymph node enlargement for 5 years and elevated creatinine for 6 months. This patient was diagnosed with angioimmunoblastic T-cell lymphoma 5 years ago and underwent multiple lines of anti-tumor therapy, including cytotoxic chemotherapy; epigenetic modifying drugs such as chidamide and azacitidine; the immunomodulator lenalidomide; and targeted therapy such as rituximab, a CD20-targeting antibody, and brentuximab vedotin, which targets CD30. Although the tumor was considered stable, multiple virus activation (including BK virus, JC virus, and cytomegalovirus) accompanied by the corresponding organ damage (polyomavirus nephropathy, cytomegalovirus retinitis, and progressive multifocal leukoencephalopathy) occurred during anti-tumor treatment. Anti-tumor therapy was suspended and ganciclovir was used. The serum viral load decreased and organ functions were stabilized. The purpose of this report was to raise clinicians' awareness of opportunistic virus reactivation during anti-tumor treatment.

[A nomogram prediction model for individualized prediction of the risk of covert (minimal) hepatic encephalopathy occurrence in patients with liver cirrhosis].

Objective: To construct an individualized nomogram prediction model for predicting the risk of the occurrence of covert hepatic encephalopathy (CHE) in patients with liver cirrhosis. Methods: 325 cases of liver cirrhosis admitted from January 2020 to December 2022 were selected as the study subjects. Patients were divided into training (n=213) and validation (n=112) sets using a cluster randomization method. The risk factors for CHE occurrence in patients with cirrhosis in the training set were analyzed by univariate and multivariate logistic regression. A prediction model related to the nomogram was established. Results: Independent risk factors for the occurrence of CHE in patients with cirrhosis were a history of hepatic encephalopathy, co-infection, gastrointestinal bleeding, severe ascites, prothrombin time ≥16 seconds, high total bilirubin, and high blood ammonia levels (P<0.05). Nomogram model validation results: The model had a net benefit for the training and validation sets, with C-indices of 0.830 (95%CI: 0.802-0.858) and 0.807 (95%CI: 0.877-0.837), respectively, within the range of 0-96%. The calibration curves of both sets were evenly close to the ideal curves. The AUCs for the ROC curves in both sets were 0.827 (95%CI: 0.796-0.858) and 0.811 (95%CI: 0.787-0.836), respectively. Conclusion: Patients with cirrhosis have many risk factors for CHE occurrence. The nomogram model constructed based on these risk factors possesses a good predictive value for assessing CHE occurrence in cirrhotic patients.

Measurement of Ultra-High-Energy Diffuse Gamma-Ray Emission of the Galactic Plane from 10 TeV to 1 PeV with LHAASO-KM2A.

The diffuse Galactic γ-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this Letter, we report the measurements of diffuse γ rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (15°10 TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of -2.99±0.04, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of ∼3 than the prediction. A similar spectrum with an index of -2.99±0.07 is found in the outer Galaxy region, and the absolute flux for 10≲E≲60 TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.

[Discrepancy between behavioral-indicated and perceived candidacy for HIV pre-exposure prophylaxis among men who have sex with men in Chengdu, China].

OBJECTIVE: To explore the discrepancy between behavioral-indicated candidacy and perceived candidacy (behavioral-perceived gap) and its associated factors of human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP) among men who have sex with men (MSM), so as to identify the focus population of PrEP interventions and to design and implement targeted interventions. METHODS: We recruited a sample of 622 HIV-negative MSM who were regular clients of a community-based organization located in Chengdu, China, from November to December 2021. A cross-sectional questionnaire was used to collect the participants' information on social demographics, PrEP-related knowledge and cognitions, and risk behaviors. In this study, behaviorally eligible for PrEP was defined as performing at least one type of high-risk behavior in the past six months, including inconsistent condom use, sex with an HIV-positive partner, confirmed sexual transmitted infections (STI) diagnosis, substance use, and post-exposure prophylaxis (PEP) experience. Logistic regression models were fitted, and multivariate analyses were adjusted for social demographics. RESULTS: Among the 622 eligible participants, 52.6% (327/622) were classified as behaviorally eligible for PrEP. Only 37.9% (124/327) of the participants perceived themselves as appropriate candidates for PrEP and 62.1% (203/207) had discrepancy between behavioral-indicated and perceived candidacy. 85.9% (281/327) had heard of PrEP, and 14.2% (40/281) accessed PrEP information through health care providers. Of the 327 participants eligible for behavior-indicated PrEP use, about half (47.1%) knew how to obtain PrEP medication and 33.0% had a professional PrEP counseling experience. The majority (93.3%) had no or few friends using PrEP. 54.1% scored eight or above in PrEP knowledge level. 66.7% reported having two or more sexual partners in the past six months. After adjusting for age and recruitment channel, we found six factors that were associated with perceived candidacy for PrEP, including PEP use [adjusted odds ratio (ORA)=2.20; 95% confidence interval (CI): 1.33-3.63], PrEP availability (ORA=1.69; 95%CI: 1.06-2.68), a greater number of PrEP-using friends (ORA=4.92; 95%CI: 1.77-13.65), PrEP know-ledge (ORA=2.21; 95%CI: 1.38-3.56), multiple sexual partnership (ORA=1.77; 95%CI: 1.07-2.94), and perceiving a higher risk of HIV infection (ORA=4.02; 95%CI: 1.73-9.32). Substance use during sex and PrEP information channel were not statistically associated with this beha-vioral-perceived gap. CONCLUSION: We observed a high discrepancy between behavioral-indicated and perceived candidacy for PrEP among Chengdu MSM in China. Future PrEP implementation efforts should be made in skills training in assessing HIV infection risk, increasing PrEP knowledge, providing professional PrEP counselling, and fostering PrEP support environment.

[An investigation on the nutritional status and support of in-patients with common variable immunodeficiency].

The study aimed to reveal for the first time the clinical characteristics, nutritional and metabolic status and support of hospitalized patients with common variant immunodeficiency disease (CVID), and provide reference to improve the long-term nutritional management for such patients. This is a retrospective cross-sectional study. Through searching the electronic medical record system of Peking Union Medical College Hospital, the study included 33 consecutive in-patients with CVID diagnosed in Jan 2016 to Jun 2021, with the male to female ratio of 16∶17. All their medical data, nutritional assessment and intervention retrospectively summarized and analyzed. Data with normal distribution were described using (x¯±s), and analyzed with independent sample t-test. Data with non-normal distribution were compared with non-parametric test. The results showed that the median onset-age of the included patients was 22 (10.0,36.5) years old, and the median duration was 9.0 (2.0,16.0) years. All patients had recurrent infections involving various systems (33/33), with development of autoimmune diseases (8/33) and lymphoproliferative disease or malignancy (9/33) in some cases among them. The nutritional risk screening 2002 (NRS 2002) scores revealed that 85.19% of adults had an NRS 2002≥3 points, and 33.33% of children had a BMI-for-age z score<-2. Weight loss occurred in 66.67% of patients (22/33), while 87.88% (29/33), 69.70% (23/33) and 81.82% (27/33) of patients respectively had anemia, hypoalbuminemia and decreased prealbumin. Among 22 patients with micronutrients status evaluated, 77.27% (17/22), 22.73% (5/22) and 31.82% (7/22) of patients respectively had lowered serum iron, folate deficiency and vitamin B12 insufficiency. Six patients underwent 25-OH-VD3 measurement, and were all testified to have vitamin D deficiency. Among all patients with nutritional risk, 56.00% of them underwent nutritional support: oral nutritional supplements (14 cases), enteral feeding (4 cases) and parenteral nutrition (5 cases). In conclusion, the condition of malnutrition was prevalent in patients with CVID, but was under-recognized and undertreated to some degree.

[Evolution and regional differences in the supportive environment for influenza vaccination among the elderly population in China].

Seasonal influenza leads to a significant disease burden, and older people infected with influenza are susceptible to various complications. Influenza immunization can prevent infection effectively and significantly reduce the risk of complications and severe cases. Creating a supportive environment for vaccination is crucial in advancing the influenza vaccination rate among the elderly population. In China, the present environment for supporting influenza vaccinations among the elderly is primarily comprised of policies for free vaccination and expense reimbursement, which exhibit noteworthy regional variations across cities and regions. This study systematically analyses the supportive environment and regional disparities associated with influenza vaccination among the elderly in China. It aims to comprehend the opportunities for influenza prevention and control resulting from the current background of influenza vaccination and to identify potential health inequality challenges caused by regional differences. The findings should inform the introduction of relevant national policies and programs to protect the health and well-being of the elderly population.

[China guideline for the screening and early detection of prostate cancer (2022, Beijing)].

Prostate cancer (PC) is one of the malignant tumors of the genitourinary system that occurs more often in elderly men. Screening, early diagnosis, and treatment of the PC high risk population are essential to improve the cure rate of PC. The development of the guideline for PC screening and early detection in line with epidemic characteristics of PC in China will greatly promote the homogeneity and quality of PC screening. This guideline was commissioned by the Bureau of Disease Control and Prevention of the National Health Commission. The National Cancer Center of China initiated and convened a working group comprising multidisciplinary experts. This guideline strictly followed the World Health Organization Handbook for Guideline Development and combined the most up-to-date evidence of PC screening, China's national conditions, and practical experience in cancer screening. A total of fifteen detailed evidence-based recommendations were provided with respect to the screening population, technology, procedure management, and quality control in the process of PC screening. This guideline aimed to standardize the practice of PC screening and improve the effectiveness and efficiency of PC prevention and control in China.

[Cardiometabolic disease patterns among elderly patients with colorectal cancer in China].

Objective: To explore the distribution patterns of cardiometabolic diseases (CMD) in elderly patients with colorectal cancer, and provide a reference for the prevention and treatment of cardiovascular metabolic diseases in these patients. Methods: Clinical data of 3 894 elderly patients with colorectal cancer from January 2008 to March 2018 admitted in the Chinese PLA General Hospital were recruited and the incidence rate of CMD was retrospectively analyzed. The influence factors of elderly patients with colorectal cancer combined with CMD were analyzed by multivariate Logistic regression model. Results: The morbidity rate of CMD in elderly patients with colorectal cancer is 33.4% (1 301/3 894), among them, the morbidity rate of the male was 31.9% (768/2 409), and that of the female was 35.9% (533/1 485). There was not significant difference between these two sex (P=0.074). The morbidity rates of CMD in patients of 65-74 years, 75-84 years and ≥85 years were 30.6% (754/2 462), 37.0% (479/1 294) and 49.3% (68/138), respectively, with significant differences (P<0.001). Multiple Logistic regression analysis revealed that female (OR=1.213, 95%CI: 1.056-1.394), age (75-84 years group: OR=1.344, 95%CI: 1.164-1.552; ≥85 years group: OR=2.345, 95%CI: 1.651-3.331) and body mass index (BMI 18.5-24.9 kg/m(2) group: OR=1.319, 95%CI: 1.065-1.638; ≥25 kg/m(2) group: OR=2.041, 95%CI: 1.627-2.561) were independent risk factors for elderly colorectal cancer patients with CMD. Conclusion: The morbidity rate of CMD in elderly patients with colorectal cancer increases with age and it is urgent to strengthen multidisciplinary cooperation and develop reasonable treatment plans to extend the survival and life quality of these patients.

[The 498th case: rash, fever and hematuria].

A 50-year-old man was admitted to the Department of Rheumatology at Peking Union Medical College Hospital with rash for 6 months, and fever and hematuria for 5 months. The main clinical manifestations included fever, fatigue, purpura, hematuria and thrombocytopenia. He was positive for antinuclear antibody (ANA), anti-neutrophil cytoplasmic antibodies (ANCA) and rheumatoid factor (RF), and had low complement levels. Initial blood culture, echocardiography and chest CT showed no signs of infection. Diagnosis of connective tissue disease was made initially. His disease improved under treatment with glucocorticoids and immunosuppressive agents, but relapsed when glucocorticoids were tapered. After admission, the diagnosis was reconsidered, and infective endocarditis was finally diagnosed with repeated positive blood cultures and vegetations detected by transesophageal echocardiography. Amoxicillin and clavulanate potassium were initiated, and surgery was performed. His symptoms finally recovered gradually.

[Clinical features and influencing factors of long-term prognosis in patients with tuberculous meningitis].

Objective: To investigate the clinical features and influencing factors of long-term prognosis of tuberculous meningitis(TBM), and to provide a recommendation for treatment and early intervention of TBM. Methods: Clinical data of TBM patients were retrospectively collected at Peking Union Medical College Hospital from January 2014 to December 2021. Patients who were followed-up more than one year were divided into two groups according to modified Rankin Scale (mRS). Risk factors associated with long-term prognosis were analyze by conditional logistic stepwise regression. Results: A total of 60 subjects were enrolled including 33 (55%) males and 27 (45%) females with age 15-79 (44.5±19.8) years. There were 30 cases (50%) complicated with encephalitis, 21 cases (35%) with miliary tuberculosis. The diagnosis was microbiologically confirmed in 22 patients (36.7%), including 5 cases (22.7%, 5/22) by acid-fast staining, 8 cases (36.4%, 8/22) by Mycobacterium tuberculosis (MTB) culture, and 20 cases (90.9%, 20/22) by molecular biology. The median follow-up period was 52(43, 66 ) months in 55 cases surviving more than one year. Among them, 40 cases (72.7%) were in favorable group (mRS 0-2) and 15 cases (27.3%) were in unfavorable group (mRS 3-6) with poor prognosis. The mortality rate was 20% (11/55). Elderly (OR=1.06, P=0.048 ) , hyponatremia(OR=0.81,P=0.020), high protein level in cerebrospinal fluid (CSF) (OR=3.32,P=0.033), cerebral infarction(OR=10.50,P=0.040) and hydrocephalus(OR=8.51,P=0.049) were associated with poor prognosis in TBM patients. Conclusions: The mortality rate is high in patients with TBM. Molecular biology tests improves the sensitivity and shorten the diagnosis time of TBM. Elderly, hyponatremia, high protein level in CSF, cerebral infarction and hydrocephalus are independent risk factors of long-term survival in TBM patients.

[Perspectives on recent monkeypox outbreak in non-endemic areas].

Monkeypox is a rare infectious disease caused by the monkeypox virus, which used to occur endemically in central and western Africa. As of 25th May, a total of 219 recently confirmed cases of monkeypox have been reported from 19 non-endemic countries. This outbreak unusually takes place in non-endemic areas for monkeypox virus and has exhibited features of high risk of human-to-human transmission. Onset of multiple human monkeypox cases may be related to the decreased level of herd cross-immunity after the cessation of smallpox vaccination. Moreover, behavioral patterns in specific populations may account for the human-to-human transmission in this outbreak. Currently, possibility of global epidemic of monkeypox is extremely low, but China should be cautious about risks of importation of monkeypox cases. The key to prevention and control is to establish a surveillance system to identify suspicious cases and close contacts as soon as possible.

[Overweight and obesity status and its associated factors among primary and secondary school students in China rural middle and western regions].

Objective: To analyze the overweight and obesity status of students in the national pilot counties of the Nutrition Improvement Program for Rural Compulsory Education Students in 2019 and its associated factors. Methods: In 2019, a multi-stage cluster random sampling method was used to select about 40 students from each grade in primary and secondary schools in China's central and western regions where the Nutrition Improvement Program for Rural Compulsory Education Students was implemented. The height and weight of the children were measured using height or weight scales. The school questionnaire and county questionnaire were used to investigate the associated factors. A Chi-square test was used for comparison between groups. The logistic regression analysis was used to analyze the associated factors. Results: In 2019, the prevalence of overweight and obesity among rural primary and secondary school students aged 6-15 years in central and western China 2019 was 11.5%. It was higher for boys (13.1%) than that for girls (9.8%), higher in central (14.3%) than that in the west (9.9%) and higher for elementary school students (12.4%) than that for secondary school students (9.5%, all P<0.001). The logistic regression showed that boys (OR=1.388), primary school students (OR=1.271), students without other dietary subsidies(OR=1.037), schools in rural areas (OR=1.133), schools with enterprise-based feeding mode (OR=1.043), schools without the provision of lunch (OR=1.143), schools without the provision of dinner (OR=1.122), and schools without providing drinking water (OR=1.015) were positively associated with overweight and obesity among students (P<0.05). Schools with snack shops (OR=0.952) were negatively associated with overweight and obesity among students (P<0.001). Conclusion: A certain proportion of primary and secondary school students in rural areas of central and western China are overweight and obese. The prevalence is not only related to children's gender, school section and county area but also related to school meals, whether schools provide drinking water and other factors.

[Exploration on teaching reform of cancer epidemiology course].

This study aims to explore optimized teaching mode of cancer epidemiology for undergraduates, and provide scientific ideas and basis for improving teaching quality. Non-randomized concurrent control study was used. Undergraduates, enrolled in 2018, from the department of preventive medicine in A and B medical universities were selected as research objects. Traditional teaching mode was used for cancer epidemiology course in A medical university, and innovative teaching mode named "one core, four dimensions" was adopted in B medical university. After the course, questionnaire method was used to investigate self-cognition of students, teaching satisfaction and class preparation time of teachers in B Medical University. The post-class test method was used to compare the students' grades of cancer epidemiology in the two universities. The results indicated that among the 58 students of B medical university, 94.83% (55/58) students were familiar with common types of epidemiological studies and 86.21% (50/58) mastered the evaluation indicators of screening research. Among the nine teaching faculties from B medical university, seven reported that the new teaching plan helped students to learn frontier knowledge of cancer epidemiology, and eight reported the new teaching model was conducive to the interaction between teachers and students. The text score of students in B medical university was 50.34±4.90, significantly higher than that in A medical university (46.21±4.91, t=5.20, P<0.001). The optimized teaching mode of cancer epidemiology is highly praised by students and teachers, which has the potential to improve students' grasp of cancer epidemiology, the ability to combine theory with practice, and the teaching effect of cancer epidemiology.

[Status and related factors on the drinking behavior among primary and secondary students in China rural middle and western regions in 2019].

Objective: To analyze the daily drinking behavior and related factors of primary and middle school students in the Nutrition Improvement Program for Rural Compulsory Education Students (NIPRCES) pilot regions. Methods: Multi-stage stratified random cluster sampling method was used to select one to three national pilot counties in 22 provinces in central and western China where the NIPRCES was implemented in 2019. According to different feeding patterns, two primary schools and two middle schools were selected as key monitoring schools. One or two classes were selected from grade 3 to grade 9. The student questionnaire was used to collect the basic information and daily drinking behavior. Taking whether the drinking water ≥5 cups every day as the dependent variable, multivariate logistic regression model was used to analyze the related factors of drinking behavior among students. Results: A total of 27 374 students were included. On average, primary and middle school students in the regions where NIPRCES was implemented had 3.9 cups of water every day. Logistic regression model showed that boys (OR=1.230, P<0.001), primary school students (OR=1.379, P<0.001), father worked outside the home (OR=1.169, P<0.001), both parents worked outside the home (OR=1.228, P<0.001), non-resident students (OR=1.142, P<0.001), the school in the village (OR=1.638, P<0.001) or township (OR=1.358, P<0.001), school feeding (OR=1.252, P<0.001), the school building with flush toilets (OR=1.384, P<0.001) and the central regions (OR=1.300, P<0.001) students were more likely to drink ≥5 cups water every day. Conclusion: The water consumption of primary and middle school students in the pilot regions of NIPRCES is low, and their drinking behaviors are affected by many factors.