Objective: To explore the relationship of physical activity (PA) and sedentary behavior (SB) with cardiorespiratory fitness (CRF) among middle schoold students in Tibet, so as to provide empirical references for improving the cardiorespiratory fitness and health levels of adolescents in Tibet. Methods: From August to December 2020, 1 225 junior and senior high school students were selected from 2 middle schools in Lhasa, Tibet Autonomous Region, using the stratified cluster random sampling method. Triaxial accelerometers were used to evaluate PA and SB behaviors, and the 20 meter shuttle run was employed to assess CRF among the middle school students. Isochronous substitution modeling was used to analyze the associations of SB, low intensity physical activity (LPA), and moderate vigorous physical activity (MVPA) with CRF, and the saturation threshold effect in the dose response relationship between MVPA and CRF was analyzed through restricted cubic spline and two stage linear regression. Results: After adjusting for covariates such as gender, body mass index and sleep quality score, isotemporal substitution analysis showed that among junior high school students aged 13-15, replacing 30 minutes of SB ( B =1.73) or LPA ( B =2.38) with MVPA were positively associated with CRF (both P <0.05). Among senior high school students aged 16-18, replacing SB ( B =0.99) or LPA ( B =1.38) with MVPA were also positively associated with CRF (both P <0.05). Restricted cubic spline and two piecewise linear regression analyses indicated that only middle school girls aged 13-18 exhibited a saturation threshold effect between MVPA and CRF (logarithmic likelihood ratio test=0.03), with the optimal CRF improvement observed at 60 minutes of MVPA per day ( B=0.13, P ＜ 0.01). Conclusions Reducing SB and LPA while increasing MVPA can improve CRF in Tibetan middle school students. To maximize CRF improvement, middle school girls should engage in at least 60 minutes of MVPA daily.

Objective: To explore the relationship between lifestyle and myopia and construct Nomogram model to predict myopia risk among primary school students in Tianjin, so as to provide a scientific basis for precision myopia prevention and control. Methods: From April to July of 2022, a census method was used to conduct vision testing and lifestyle related questionnaires among 373 180 primary school students in 15 districts of Tianjin. The relationship between lifestyle and myopia was analyzed by the multivariate Logistic regression, and a nomogram prediction model was constructed to predict myopia risk. Results: The detection rate of myopia among primary school students in Tianjin was 37.6%. The results of the multivariate Logistic regression showed that daily outdoor activity time of 1-2 h ( OR =0.94) and >2 h ( OR =0.84), time of using daily electronic devices of >2 h ( OR =1.03), daily paper materials reading and writing time of 1-2 h ( OR =1.02) and >2 h ( OR =1.09), weekly fresh vegetable intake of 2-6 times ( OR =0.93) and ≥7 times ( OR =0.88) were statistically correlated with myopia ( P <0.01). The Nomogram prediction model showed that the factors associated with myopia were grade, family history of myopia, gender, daily outdoor activity time, weekly frequency of fresh vegetable intake, daily paper materials reading and writing time, and time of using daily electronic devices time. Conclusions The lifestyle of primary school students in Tianjin is associated with myopia. The constructed nomogram model could provide a scientific basis for identifying key intervention populations for myopia prevention and taking targeted prevention and control measures.

Objective To explore the eye behaviors and myopia-related risk factors among primary and secondary school students in Tianjin,in order to carry out targeted eye health education and guidance.Methods A cross-sectional study was conducted.In December 2021,an eye health questionnaire was distributed to primary and secondary school students in Tianjin to investigate their eye habits;combined with the campus vision screening data in the second half of 2021,a multivariate logistic regression analysis model was constructed to explore the risk factors related to myopia.Re-sults A total of 821 459 questionnaires were collected,including 701 104 valid questionnaires.The usage time of electron-ic learning products and electronic entertainment products for primary school students was mostly less than 1 hour(ac-counting for 57.74％and 40.98％,respectively).The population of junior high school students who spend more than 2 hours using electronic learning products and electronic entertainment products(accounting for 26.61％and 35.05％,re-spectively)significantly increased compared to primary school students(accounting for 11.21％and 20.93％,respective-ly).Most senior high school students spend more than 2 hours daily using electronic devices for learning and entertainment purposes,as well as reading paper materials.51.59％of primary school students do not meet the standard for sleep dura-tion,while the rate of reaching the standard sleep duration of junior high and senior high school students was 60.09％and 64.99％,respectively.Most(55.74％)primary and secondary school students have an average outdoor activity duration of 1-2 hours daily.The results of multivariate logistic regression analysis showed that the risk of myopia in primary school students was correlated with the time spent using electronic products(including learning and entertainment),the time spent reading paper materials at a close range,outdoor activities,time to fall asleep,and sleep duration(all P＜0.05);the risk of myopia among junior high school students was related to the time spent using electronic entertainment products,reading paper materials at a close range,outdoor activities,and sleep duration(all P＜0.05);the risk of myopia among senior high school students was only related to the time spent reading paper materials at a close range and the duration of outdoor activities(both P＜0.05).Conclusion The proportion of primary school students,junior high school students and senior high school students in Tianjin who use electronic products for more than 2 hours is gradually increasing,and the rate of reaching the standard sleep duration is gradually increasing.The risk of myopia among these students is related to the time spent reading paper materials at a close range and outdoor activities.Science popularization should be carried out and management of eye behaviors should be strengthened in the whole society to reduce myopia rates in children and adolescents in China.

Objective:To investigate the factors affecting phenotypes in the patients of methylmalonic acidemia combined with homocysteinemia cblC type with MMACHC c. 609G>A homologous variant. Methods:A retrospective study on the clinical manifestations, complications, treatment, and outcome in 164patients of cblC type with MMACHC c. 609G>A homologous variant was conducted.The patients were diagnosed by biochemical and genetic analysisfrom January 1998 to December 2020. Results:Among the 164 patients, 2 cases were prenatally diagnosed and began treatment after birth. They are 3 and 12 years old with normal physical and mental development. Twenty-one cases were diagnosed by newborn screening. Among them, 15 cases had with normal development. They were treated fromthe age of two weeks at the asymptomatic period. Six cases began treatment aged 1 to 3 months after onset. Their development was delayed. One hundred and forty-one cases were clinically diagnosed. Their onset age ranges from a few minutes after birth to 6 years old. 110 cases had early-onset (78.0%). 31 cases had late-onset (22.0%). Five of them died. 24 patients lost to follow-up. Of the 141 clinically diagnosed patients, 130 (92.2%) with psychomotor retardation, 69 (48.9%) with epilepsy, 39 (27.7%) with anemia, 30 (21.3%) had visual impairment, 27 (19.1%) had hydrocephalus, 26 (18.4%) had feeding difficulties, 7 (5.0%) with liver damage, and 5 (3.5%) with metabolic syndrome. The frequency of hydrocephalus and seizures was significantly higher in the early-onset group. The urinary methylmalonic acid increased significantly in the patients with epilepsy. During the long-term follow-up, the level of plasma total homocysteine in the seizure-uncontrolled group was significantly higher than that in the seizure-controlled group, the difference had a statistical significance ( P<0.05). Conclusion:Most of the patients with MMACHC c. 609G>A homozygous variant had early-onset disease, with a high mortality and disability rate. If not treated in time, it will lead to neurological damage, resulting in epilepsy, mental retardation, hydrocephalus, and multiple organ damage. Pre-symptomatic diagnosis and treatment are crucial to prevent irreversible neurological damage. Neonatal screening and prenatal diagnosis are important to improve the outcome of the patients.

Objective:To analyze the clinical features, genetic characteristics, treatment and follow-up results of patients with hydrocephalus caused by methylmalonic acidemia combined with homocysteinuria, and to discuss the optimal strategies for assessing and treating such patients.Methods:From January 1998 to December 2020, 76 patients with hydrocephalus due to methylmalonic acidemia combined with homocysteinuria in the Department of Pediatrics in 11 hospitals including Peking University First Hospital were diagnosed by biochemical, genetic analysis and brain imaging examination. The patients were divided into operation-group and non-operation-group according to whether they underwent ventriculoperitoneal shunt. The clinical features, laboratory examinations, genotype, and follow-up data were retrospectively analyzed. Data were compared between the two groups using rank sum test, and categorical data were compared using χ 2 test. Results:Among the 76 patients (51 male, 25 female), 5 were detected by newborn screening, while 71 were diagnosed after clinical onset, 68 cases (96%) had early-onset, 3 cases (4%) had late-onset. The most common clinical manifestations of 74 cases with complete data were psychomotor retardation in 74 cases (100%), visual impairment in 74 cases (100%), epilepsy in 44 cases (59%), anemia in 31 cases (42%), hypotonia or hypertonia in 21 cases (28%), feeding difficulties in 19 cases (26%) and disturbance of consciousness in 17 cases (23%). Genetic analysis was performed in 76 cases, all of whom had MMACHC gene variations, including 30 homozygous variations of MMACHC c.609G>A. The most common variations were c.609G>A (94, 62.7%), followed by c.658_660del (18, 12.0%), c.567dupT (9, 6.0%) and c.217C>T (8, 5.3%). Therapy including cobalamin intramuscular injection, L-carnitine and betaine were initiated immediately after diagnosis. A ventriculoperitoneal shunt operation was performed in 41 cases (operation group), and 31 patients improved after metabolic intervention (non-operation group). There was no significant difference in the age of onset, the age of diagnosis, the blood total homocysteine, methionine, and urinary methylmalonic acid concentration between the two groups (all P>0.05). The symptoms of psychomotor development, epilepsy, and visual impairments improved gradually after a long-term follow-up in the operation group. Conclusions:Hydrocephalus is a severe complication of methylmalonic acidemia combined with homocysteinuria. The most common clinical manifestations are psychomotor retardation, visual impairment, and epilepsy. It usually occurs in early-onset patients. Early diagnosis and etiological treatment are very important. Hydrocephalus may improve after metabolic intervention in some patients. For patients with severe ventricular dilatation, prompt surgical intervention can improve the prognosis.

Objective: Based on the MSM college students in Tianjin, this study aims to explore the demographic and behavioral characteristics of MSM with different sexual partners, and to provide evidence and information for intervention in combination with social networks. Methods: According to the source and access of seeking sexual partners, 546 MSM of Tianjin college students aged 18-24 in 2018 Jan. and 2019 Dec. were divided into internet-based MSM (396) and traditional MSM (150). Chi-square test and rank-sum test were used to compare the demographic information, sexual behavior characteristics, HIV prevention and testing awareness, and psychoactive substance use of the two MSMs, and Logistic regression was used to explore factors affecting college students use of the Internet for sexual partners. Results: Internet-based MSM has advantages in receiving HIV testing and safety consulting services, AIDS knowledge level, and peer education in the past year (P<0.05). The psychoactive substance use of the survey population reached more than 40%, and the awareness rates of pre-exposure prophylaxis and post-exposure prophylaxis were 32.98% and 55.32%, respectively. After multivariate Logistic regression analysis, MSM students who had received condom distribution, AIDS counseling and peer education (OR=2.16, 1.98, P<0.01) were more inclined to use the Internet for sexual partners. Conclusion Relevant departments can use the Internet to intervene in the prevention and control of MSM in colleges and universities in terms of AIDS-related knowledge, HIV testing, and mental substances.

Objectives:To summarize the clinical and genetic characteristics of the patients with isolated methylmalonic acidemia and investigate the strategies for the diagnosis, treatment and prevention.Methods:Three hundred and fourteen patients (180 males, 134 females) with isolated methylmalonic acidemia were ascertained from 26 provinces or cities across the mainland of China during January 1998 to March 2020. Genetic analysis was performed by Sanger sequencing, gene panel sequencing, whole exome sequencing, multiplex ligation-dependent probe amplification or quantitative PCR. According to the age of onset, the patients were divided to early-onset group (≤12 months of age) and the late-onset group (>12 months of age). They were treated by cobalamin, L-carnitine and (or) special diet and symptomatic treatment. Statistical analysis was done using Chi-square test.Results:Fifty-eight of 314 (18.5%) patients were detected by Newborn screening using liquid chromatography tandem mass spectrometry. Five cases (1.6%) had a postmortem diagnosis. Two hundred and fifty-one patients (79.9%) were clinically diagnosed with an age of onset ranged from 3 hours after birth to 18 years. One hundred and fifty-nine patients (71.0%) belonged to early-onset groups, 65 patients (29.0%) belonged to the late-onset group. The most common symptoms were metabolic crises, psychomotor retardation, epilepsy, anemia and multiple organ damage. Metabolic acidosis and anemia were more common in early-onset patients than that in late-onset patients (20.8%(33/159) vs. 9.2% (6/65), 34.6% (55/159) vs. 16.9% (11/165), χ 2=4.261, 6.930, P=0.039, 0.008). Genetic tests were performed for 236 patients (75.2%), 96.2%(227/236) had molecular confirmation. One hundred and twenty-seven variants were identified in seven genes (MMUT, MMAA, MMAB, MMADHC, SUCLG1, SUCLA2, and MCEE), of which 49 were novel. The mut type, caused by the deficiency of methylmalonyl-CoA mutase, was the most common ( n=211, 93%) cause of this condition. c.729_730insTT, c.1106G>A and c.914T>C were the three most frequent mutations in MMUT gene. The frequency of c.914T>C in early-onset patients was significantly higher than that in late-onset patients (8.3% (18/216) vs. 1.6% (1/64), χ 2=3.859, P=0.037). Metabolic crisis was more frequent in mut type than the other types (72.6% (114/157) vs. 3/13, χ 2=13.729, P=0.001),developmental delay and hypotonia were less frequent in mut type (38.2% (60/157) vs. 9/13, 25.5% (40/157) vs. 8/13, χ 2=4.789, 7.705, P=0.030, 0.006). Of the 58 patients identified by newborn screening, 44 patients (75.9%) who were treated from asymptomatic phase developed normally whereas 14 patients (24.1%) who received treatment after developing symptoms exhibited varying degrees of psychomotor retardation. Conclusions:The characteristics of phenotypes and genotypes among Chinese patients with isolated methylmalonic acidemia were analyzed. Expanded the mutation spectrum of the associated genes. Because of the complex clinical manifestations and severe early onset of isolated methylmalonic acidemia, Newborn screening is crucial for early diagnosis and improvement of prognosis. MMUT gene is recommended for carrier screening as an effort to move the test earlier as a part of the primary prevention of birth defects.

Objectives: To propose a novel clinical classification system of gallbladder cancer, and to investigate the differences of clinicopathological characteristics and prognosis based on patients who underwent radical resection with different types of gallbladder cancer. Methods: The clinical data of 1 059 patients with gallbladder cancer underwent radical resection in 12 institutions in China from January 2013 to December 2017 were retrospectively collected and analyzed.There were 389 males and 670 females, aged (62.0±10.5)years(range:22-88 years).According to the location of tumor and the mode of invasion,the tumors were divided into peritoneal type, hepatic type, hepatic hilum type and mixed type, the surgical procedures were divided into regional radical resection and extended radical resection.The correlation between different types and T stage, N stage, vascular invasion, neural invasion, median survival time and surgical procedures were analyzed.Rates were compared by χ² test, survival analysis was carried by Kaplan-Meier and Log-rank test. Results: Regional radical resection was performed in 940 cases,including 81 cases in T1 stage,859 cases in T2-T4 stage,119 cases underwent extended radical resection;R0 resection was achieved in 990 cases(93.5%).The overall median survival time was 28 months.There were 81 patients in Tis-T1 stage and 978 patients in T2-T4 stage.The classification of gallbladder cancer in patients with T2-T4 stage: 345 cases(35.3%)of peritoneal type, 331 cases(33.8%) of hepatic type, 122 cases(12.5%) of hepatic hilum type and 180 cases(18.4%) of mixed type.T stage(χ²=288.60,P<0.01),N stage(χ²=68.10, P<0.01), vascular invasion(χ²=128.70, P<0.01)and neural invasion(χ²=54.30, P<0.01)were significantly correlated with the classification.The median survival time of peritoneal type,hepatic type,hepatic hilum type and mixed type was 48 months,21 months,16 months and 11 months,respectively(χ²=80.60,P<0.01).There was no significant difference in median survival time between regional radical resection and extended radical resection in the peritoneal type,hepatic type,hepatic hilum type and mixed type(all P>0.05). Conclusion With application of new clinical classification, different types of gallbladder cancer are proved to be correlated with TNM stage, malignant biological behavior and prognosis, which will facilitate us in preoperative evaluation,surgical planning and prognosis evaluation.

OBJECTIVE: To analyze carbapenemases genotype of imipenem-resistant Gram-negative bacilli in intensive care unit (ICU) of 3 third grade class A hospitals from Qingdao area, so as to provide reference for drug-resistant bacteria infection prevention and treatment in clinic. METHODS: From Jan. 2013 to Jun. 2016, each 60 strains of imipenem-resistant Klebsiella pneumoniae (IRKP), imipenem-resistant Pseudomonas aeruginosa (IRPA) and imipenem-resistant Acinetobacter baumanii (IRAB) were collected from 3 third grade class A hospitals from Qingdao area. Drug sensitivity test was performed by using Kirby-Bauer method. Phenotypes of carbapenemases were determined by Carba NP trial. PCR was applied to amplify carbapenemase gene; Sanger seqnencing method was adopted for bi-directional sequencing; Blast comparison with GenBank database was conducted. RESULTS: Three kinds of imipenem-resistant Gram-negative bacilli showed high drug resistance to majority commonly used antibiotics as piperacillin, cefazolin, imipenem and cilastatin sodium, gentamicin, etc., but were sensitive to polymyxin B (resistance rate of 0). Among 180 drug-resistant strains, there were 52 strains of class A carbapenems, 13 strains of class B carbapenems and 39 strains of class D carbapenems; the detection rates of them were 28. 89％, 7. 22％ and 21. 67％, respectively. There were 52 strains of KPC-2 gene (IRKP), 4 strains of IMP-1 gene (IRPA), 8 strains of VIM-2 gene (7 strains of IRPA, 1 strain of IRAB), 39 strains of OXA-23 gene (IRAB); the detection rates of them were 28. 89％, 2. 22％, 4. 44％, 21. 67％; all strains were not detected 1MP-2, VIM-1, NDM-1, OXA-24, OXA-58 genes. Results of Blast comparison showed that above detected genes were absolutely homology with the corresponding genes in GenBank database. CONCLUSIONS: Drug resistance of imipenem-resistant Gram-negative bacilli in ICU of 3 third grade class A hospitals is serious in this region, which are nearly no-sensitive to most of commonly used antibiotics in clinic. Main genotypes included KPC-2 (K. pneumoniae), OXA-23 (A. baumanii) and IMP-1 and VIM-2 (P. aeruginosa).

Objective To design a novel electronic device for measuring the pressure in the cuff of the artificial airway; and to study the advantage of this device on continuous and intermittent cuff pressure monitoring. Methods ① a portable electronic device for cuff pressure measurement was invented, which could turn pressure signal into electrical signal through a pressure transducer. Meantime, it was possible to avoid pressure leak from the joint and the inside of the apparatus by modified Luer taper and sophisticated design. If the cuff pressure was out of the normal range, the apparatus could release a sound and light alarm. ② Six traditional mechanical manometers were used to determine the cuff pressure in 6 tracheal tubes. The cuff pressure was maintain at 30 cmH2O (1 cmH2O =0.098 kPa) by the manometer first, and repeated every 30 seconds for 4 times. ③ Study of continuous cuff pressure monitoring: We used a random number generator to randomize 6 tracheal tubes, 6 mechanical manometers and 6 our products by number 1-6, which has the same number of a group. Every group was further randomized into two balanced groups, one group used the mechanical manometer first, and the other used our product first. The baseline pressure was 30 cmH2O, measurement was performed every 4 hours for 6 times. Results When traditional mechanical manometer was used for cuff pressure monitoring, cuff pressure was decreased by an average of 2.9 cmH2O for each measurement (F = 728.2, P = 0.000). In study of continually monitoring, at each monitoring point, the pressure measured by electronic manometer was higher than the mechanical manometer. All the pressures measured by mechanical manometer were dropped below 20 cmH2O at 8th hour, and there was no pressure decrease below 20 cmH2O measured by electronic manometer in 24 hours by contrast. In study of intermittent monitoring, the same result was found. The pressure was dropped significantly with time when measured by mechanical manometer (F = 61.795, P = 0.000), the drops below 20 cmH2O began at 8th hour; but when measured by electronic manometer, all the value stayed unchanged around the baseline in 24 hours (F = 0.511, P = 0.796). Conclusions Compared with traditional mechanical manometer, cuff pressures monitored by our novel electronic manometer were steadier in both continuous and intermittent monitoring. The device is compact and convenient, and can provide a good solution for continuously monitor of the tracheal cuff pressure.