[Analysis of the correlation between peri-implant probing depth and radiographic bone level].

Objective: To evaluate the correlation between peri-implant probing depth (PPD) and radiographic bone level (rBL) in implants with peri-implantitis. Methods: From January 2019 to December 2022, 24 patients with 30 implants who suffered from peri-implantitis at the Department of Periodontology, Peking University School and Hospital of Stomatology were included in the present research. SPSS 26.0 software (IBM, U S A) was used to simple random sampling select 30 healthy implants from which with electronic examination records in Department of Periodontology, Peking University School and Hospital of Stomatology from January 2007 to June 2023 as the control group. On the premise of retaining the implant prosthesis, PPD (distance between pocket bottom and peri-implant soft tissue margin) was examined using a Williams periodontal probe with a light force (about 0.2 N), and a total of 4 sites were recorded for each implant. Periapical radiography and cone beam CT were applied to measure the rBL (distance between the reference point at the neck of the implant and the apical point of the bone defect) and the width of the bone defect (DW), and the type of the bone defect was recorded. The correlation and consistency between the diagnosis of PPD and rBL were analyzed. Results: PPD was significantly correlated with rBL in a total of 60 implants in 180 sites(r=0.64, P<0.001). The chi-square test showed an 8.15-fold increase in the detection rate of PD≥6 mm at sites with rBL≥1 mm (P<0.001). Multivariate logistic regression analysis showed that rBL was still statistically associated with PPD after adjustment for jaw position and examination position of implants. Take rBL <1 mm as reference, the odds ratios (OR) of 1 mm≤rBL<2 mm, 2 mm≤rBL<3 mm and rBL≥3 mm group with PPD were 6.23 (P=0.014), 2.77 (P=0.183) and 10.87 (P=0.001), respectively. Conclusions: There is a positive correlation between PPD and rBL in implants with peri-implantitis. PPD can be used as a clinical examination index to assist in estimating the level of peri-implant bone under the premise of retaining the prosthesis.

[Medicinal Characteristics of Shao Jiu in Compendium of Materia Medica].

Modern Bai Jiu(liquor) was called Shao Jiu in ancient times.By consulting ancient books, it was found that there was a distillation and preparation process of Shao Jiu before the Ming Dynasty, but due to its high toxicity, the scope of application was limited, and there were few records of its medicinal use.However many records of its medicinal use was found in the Compendium of Materia Medica(«¼).By comparing the medical books that recorded Shao Jiu in previous dynasties, it is found that the Compendium of Materia Medica comprehensively records the relevant cognition and application of the medicinal use of Shao Jiu for the first time. The book lists in detail the causes of the toxicity of Shao Jiu and the methods to avoid it, comprehensively expounds its characteristics, efficacy and indications, lists a variety of ways to use it, skillfully uses Shao Jiu to treat syphilis sores, and proposes that high-concentration Shao Jiu can be used as a solvent for medical liquor.The record of Shao Jiu in the Compendium of Materia Medica had a profound impact on the medical liquor of later generations.The use of Shao Jiu in the Qing Dynasty continued to expand, and the types of medicinal liquor were also constantly enriched. The record of Shao Jiu in the Compendium of Materia Medica can also provide a reference for the medicinal use of modern liquor.

[Etiological diagnostic methods and research progress of forest encephalitis].

Forest encephalitis is a natural focal disease transmitted through the bite of hard ticks, and its pathogen is the tick-borne encephalitis virus from the Flaviviridae family. The mortality rate of forest encephalitis is relatively high, making laboratory testing significant in diagnosing this disease. This article elaborates on the etiological diagnostic methods and recent research progress in forest encephalitis. Laboratory tests for forest encephalitis mainly include routine examinations, serological tests, virus isolation, and molecular biological testing. The detection of serum-specific IgM antibodies against the forest encephalitis virus is of great importance for early diagnosis, and specific IgG antibodies serve as a "gold standard" for differentiation from other diseases. Techniques such as enzyme-linked immunosorbent assay (ELISA) or indirect immunofluorescence assay for detecting specific IgM antibodies in serum and/or cerebrospinal fluid, the serum hemagglutination inhibition test or serum complement fixation test, and the double serum hemagglutination inhibition test or complement fixation test all contribute to the early diagnosis. The development of molecular testing methods is rapid, and techniques such as metabolomics, digital PCR, and matrix metalloproteinases are also applied in the early diagnosis of forest encephalitis.

[Interpretation of the European Federation of Periodontology S3 level clinical practice guideline for prevention and treatment of peri-implant diseases].

The S3 level clinical practice guideline for the prevention and treatment of peri-implant diseases, developed by the European Federation of Periodontology, was published in June, 2023 (DOI: 10.1111/jcpe.13823), which culminated in the recommendations for implementation of various different interventions before, during and after implant placement/loading. Aim of the present article is to summarize and interpret the key points of this guideline and help clinicians understand this guideline better, in order to standardize the prevention and treatment of peri-implant diseases.

[Research on the association between the occurrence of spermarche and menarche and psychological distress among Chinese children and adolescents aged 9-18 years].

Objective: To analyze the association between the occurrence of spermarche and menarche and psychological distress among Chinese Han children and adolescents aged 9 to 18 years. Methods: Data were drawn from the 2019 Chinese National Survey on Students' Constitution and Health, and a total of 54 438 boys aged 11 to 18 years and 76 376 girls aged 9 to 18 years with psychological distress, spermarche/menarche records were included in the final analysis. The occurrence of spermarche/menarche was recorded by physicians, and psychological distress was classified according to the Kessler Psychological Distress Scale scores. The chi-square test was used to compare the difference between groups in the occurrence of spermarche/menarche, and the multinomial logistic regression model and stratification analysis was established to analyze the association between psychological distress and spermarche/menarche. Results: The incidence of spermarche/menarche in 2019 ranged from 6.3% to 96.5% for eight age groups of Chinese boys and 2.8% to 99.0% for ten age groups of girls. The rates of high psychological distress among boys and girls were 32.5% and 32.7%. Among boys aged 11 to 18 years, the rate of high psychological distress increased with age, with a trend test P<0.001, and the difference in the rate of high psychological distress between those who had and had not had their spermarche was not statistically significant in all age groups. Among girls aged 9 to 18 years, the rate of high psychological distress increased with age, with a trend P<0.001; the rate of high psychological distress was higher in the group with menarche at age 10 and 12 than in the group without menarche (all P<0.05). High psychological distress was positively correlated with spermarche among boys aged 13-15 years living in urban areas and hight level economic development areas (OR=1.11, 95%CI: 1.02-1.21;OR=1.18, 95%CI: 1.06-1.32). Overall, high psychological distress was positively correlated with menarche in girls aged 9-12 and 13-15 years (OR=1.33, 95%CI: 1.25-1.42; OR=1.22, 95%CI: 1.07-1.39). High psychological distress was positively correlated with menarche among girls aged 9-12 years living in different regions except for the Northeast region, in areas with different levels of economic development, and in urban and rural areas, in girls aged 13-15 years living in urban, central, and western regions, and in girls aged 16-18 years residing in the central region. Conclusions: This study found an association between the occurrence of spermarche/menarche and psychological distress among Chinese Han children and adolescents aged 9 to 18 years in 2019, which was particularly significant among girls aged 9 to 12 years and boys aged 13 to 15 years living in areas with higher levels of socioeconomic development.

[Prevalence of psychological distress among Chinese children and adolescents aged 9-18 years].

Objective: To describe the prevalence of psychological distress and to analyze its influencing factors among Chinese children and adolescents aged 9-18 years in 2019. Methods: Data was from the 2019 Chinese National Survey on Students' Constitution and Health, and 148 892 children and adolescents were included. Psychological distress was measured using the Kessler Psychological Distress Scale (K10): scores ≤19 were defined as no psychological distress, scores between 20-24 were defined as mild psychological distress, scores between 25-29 were defined as moderate psychological distress, and scores ≥30 were defined as severe psychological distress (moderate to severe psychological distress were defined as high psychological distress). The ANOVA, t test, and χ2 test were used to compare the differences in K10 scores and high psychological distress rates among children and adolescents with different characteristics. The ANOVA and trend χ2 test were used to analyze the trends. Modified-Poisson regression models were used to determine influencing factors of high psychological distress. Results: The K10 scores for Chinese children and adolescents aged 9-18 years in 2019 was 21.5±9.2, and their rate of high psychological distress was 31.6%. The rates of high psychological distress among children and adolescents aged 9-12, 13-15, and 16-18 years were 22.3%, 35.9%, and 38.8%. K10 scores and rates of high psychological distress showed an increasing trend as age increased (trends test all P<0.001). K10 scores and rates of high psychological distress were higher among children and adolescents who were older, female, rural, in areas with medium to low GDP per capita level, and with lower parental education (all P<0.001). Multifactorial modified-Poisson regression analysis showed that children and adolescents aged 13-15 years, 16-18 years, female, rural, and in areas with low to moderate GDP per capita level were at higher risk of high psychological distress (all P<0.05), with aOR (95%CI) of 1.55 (1.52-1.58), 1.66 (1.63-1.69), 1.07 (1.05-1.09), 1.02 (1.01-1.04), 1.10 (1.07-1.12). Children and adolescents in areas with medium to high GDP per capita level, whose father had a secondary or high school degree, whose father had a college degree or above, whose mother had a secondary or high school degree, and whose mother had a college degree or above were at lower risk of high psychological distress (all P<0.05), with aOR (95%CI) of 0.96 (0.94-0.98), 0.92 (0.90-0.93), 0.84 (0.82-0.86), 0.95 (0.93-0.97), 0.86 (0.83-0.88). Conclusions: The prevalence of psychological distress was high among Chinese children and adolescents aged 9-18 years in 2019, which is a vital problem. Mental health interventions need to be implemented among children and adolescents that were older, girls, rural, live in areas with lower economic levels, and whose parents have a lower education level.

[Research on the association between the status of physical fitness and psychological distress among Chinese children and adolescents aged 13-18 years].

Objective: To describe the status of physical fitness of children and adolescents aged 13-18 years in China in 2019 and analyze its association with psychological distress. Methods: Data were drawn from the 2019 Chinese National Survey on Students' Constitution and Health, and 90 633 Han children and adolescents aged 13-18 years were included. Physical fitness was evaluated by "National Students Constitutional Health Standards" (2014 revised edition). Psychological distress was classified according to the scores of the Kessler Psychological Distress Scale: ≤19, 20-24, 25-29, and ≥30 scores indicated no, mild, moderate, and severe psychological distress, respectively, with moderate and severe psychological distress collectively referred to as high psychological distress. The χ2 test was used to compare the distribution differences between boys and girls, the Cochran-Armitage test was used to analyze the trend, and the multinomial logistic regression in the mixed effect model was established to analyze the association between physical fitness and psychological distress. Results: In 2019, the unqualified rate of physical fitness among children and adolescents aged 13-18 years in China was 17.2%, and the prevalence of excellent and good physical fitness was 18.2%, which was lower among boys (15.9%) than girls (20.5%) with a statistically significant difference (P<0.05). The excellent and good physical fitness rate showed a significantly decreasing trend with age (trend test P<0.05). The rate of high psychological distress among children and adolescents aged 13-18 years in China in 2019 was 39.3%, with boys (37.0%) having a lower prevalence than girls (41.6%), supported by a statistically significant difference (P<0.05), and a decreasing trend with the degree of physical fitness was observed both in boys and girls (trend test P<0.05). The multinomial logistic regression model showed that the prevalence of moderate (OR=0.83, 95%CI: 0.79-0.88, P<0.001) and severe (OR=0.81, 95%CI: 0.77-0.86, P<0.001) psychological distress were both lower in children and adolescents with excellent and good physical fitness. Conclusion: The status of physical fitness and psychological distress of Chinese children and adolescents aged 13-18 in 2019 was not optimistic, with physical fitness showing a significantly negative association with psychological distress.

[Cardiac progenitor cells-derived exosomes alleviate myocardial injury by regulating Treg cell differentiation through the mTOR pathway in mice with myocardial infarction].

OBJECTIVE: To investigate the effect of cardiac progenitor cells-derived exosomes (CPCs-Exo) on Treg differentiation in mice with myocardial infarction (MI). METHODS: Mouse models of MI established by ligation of the left anterior descending coronary artery (LAD) were treated with CPCs-Exos, and naive CD4+T cells were isolated from the spleen of the mice and divided into control group, CD4+T cell activation group (CD3+CD28), CPCs-Exos stimulation group (CD3+CD28+CPCs-Exos), mTOR activator group (CD3+CD28+CPCs-Exos+mTOR activator) and mTOR inhibitor group (CD3+CD28+CPCs-Exos+mTOR inhibitor). Western blotting was used to detect the expression levels of mTOR and p-mTOR in the treated cells. Flow cytometry was used to analyze the percentages of Treg and CD4+IL-10+T cells. The infarct size of the mice were measured with 2, 3, 5-triphenyltetrazole chloride (TTC) staining, and serum levels of LDH and CK-MB were detected using an automatic biochemical analyzer. RESULTS: Compared with the control group, the mouse models of MI showed significantly increased release of LDH (P<0.001) and CK-MB (P=0.0002) and increased percentages of Treg and CD4+IL-10+T cells. Treatment with CPC-Exos effectively reduced the MI area and lowered serum levels of LDH (P=0.003) and CK-MB (P=0.003) and the percentages of Tregs (P=0.001) and CD4+IL-10+T cells (P=0.004) in the MI mouse models. In the isolated CD4+T cells, CPCsExos treatment significantly up-regulated the percentages of Treg (P=0.01) and CD4+IL-10+ T cells (P=0.004) and increased the expression of mTOR (P=0.009) and p-mTOR (P=0.009), and these effects could be further enhanced by the mTOR activator but obviously attenuated by the mTOR inhibitor. CONCLUSION: CPCs-Exos promotes the differentiation of Treg in mice with MI by modulating the mTOR signaling pathway.

[Clinical implications of thrombolytic therapy for patients with acute intermediate-high risk pulmonary embolism in Tibet plateau, China].

At present, clinical studies and case reports of systemic thrombolytic therapy for patients with acute pulmonary embolism in Tibet Plateau are very rare. There is little understanding of the risk factors, clinical characteristics, and thrombolytic therapy for patients with acute pulmonary embolism at intermediate-high risk in Tibet Plateau. In this paper, we reported the data of 4 patients with acute intermediate-high risk pulmonary embolism treated with thrombolytic therapy in Lhasa People's Hospital. The demographic characteristics, clinical manifestations, treatment, and outcomes were analyzed. We summarized the clinical features and raised scientific issues. We aimed to provide basic data to improve the standardized diagnosis and treatment of acute pulmonary embolism in plateau, and to point out the direction of future clinical research in this field.

Machine learning dislocation density correlations and solute effects in Mg-based alloys.

Magnesium alloys, among the lightest structural materials, represent excellent candidates for lightweight applications. However, industrial applications remain limited due to relatively low strength and ductility. Solid solution alloying has been shown to enhance Mg ductility and formability at relatively low concentrations. Zn solutes are significantly cost effective and common. However, the intrinsic mechanisms by which the addition of solutes leads to ductility improvement remain controversial. Here, by using a high throughput analysis of intragranular characteristics through data science approaches, we study the evolution of dislocation density in polycrystalline Mg and also, Mg-Zn alloys. We apply machine learning techniques in comparing electron back-scatter diffraction (EBSD) images of the samples before/after alloying and before/after deformation to extract the strain history of individual grains, and to predict the dislocation density level after alloying and after deformation. Our results are promising given that moderate predictions (coefficient of determination [Formula: see text] ranging from 0.25 to 0.32) are achieved already with a relatively small dataset ([Formula: see text] 5000 sub-millimeter grains).

[Clinical and genetic characteristics of young patients with myeloproliferative neoplasms].

Objectives: To investigate the clinical and genetic features of young Chinese patients with myeloproliferative neoplasms (MPN). Methods: In this cross-sectional study, anonymous questionnaires were distributed to patients with MPN patients nationwide. The respondents were divided into 3 groups based on their age at diagnosis: young (≤40 years) , middle-aged (41-60 years) , and elderly (>60 years) . We compared the clinical and genetic characteristics of three groups of MPN patients. Results: 1727 assessable questionnaires were collected. There were 453 (26.2%) young respondents with MPNs, including 274 with essential thrombocythemia (ET) , 80 with polycythemia vera (PV) , and 99 with myelofibrosis. Among the young group, 178 (39.3%) were male, and the median age was 31 (18-40) years. In comparison to middle-aged and elderly respondents, young respondents with MPN were more likely to present with a higher proportion of unmarried status (all P<0.001) , a higher education level (all P<0.001) , less comorbidity (ies) , fewer medications (all P<0.001) , and low-risk stratification (all P<0.001) . Younger respondents experienced headache (ET, P<0.001; PV, P=0.007; MF, P=0.001) at diagnosis, had splenomegaly at diagnosis (PV, P<0.001) , and survey (ET, P=0.052; PV, P=0.063) . Younger respondents had fewer thrombotic events at diagnosis (ET, P<0.001; PV, P=0.011) and during the survey (ET, P<0.001; PV, P=0.003) . JAK2 mutations were found in fewer young people (ET, P<0.001; PV, P<0.001; MF, P=0.013) ; however, CALR mutations were found in more young people (ET, P<0.001; MF, P=0.015) . Furthermore, mutations in non-driver genes (ET, P=0.042; PV, P=0.043; MF, P=0.004) and high-molecular risk mutations (ET, P=0.024; PV, P=0.023; MF, P=0.001) were found in fewer young respondents. Conclusion: Compared with middle-aged and elderly patients, young patients with MPN had unique clinical and genetic characteristics.

Postoperative pulmonary complications in older patients undergoing elective surgery with a supraglottic airway device or tracheal intubation.

The two most commonly used airway management techniques during general anaesthesia are supraglottic airway devices and tracheal tubes. In older patients undergoing elective non-cardiothoracic surgery under general anaesthesia with positive pressure ventilation, we hypothesised that a composite measure of in-hospital postoperative pulmonary complications would be less frequent when a supraglottic airway device was used compared with a tracheal tube. We studied patients aged ≥ 70 years in 17 clinical centres. Patients were allocated randomly to airway management with a supraglottic airway device or a tracheal tube. Between August 2016 and April 2020, 2900 patients were studied, of whom 2751 were included in the primary analysis (1387 with supraglottic airway device and 1364 with a tracheal tube). Pre-operatively, 2431 (88.4%) patients were estimated to have a postoperative pulmonary complication risk index of 1-2. Postoperative pulmonary complications, mostly coughing, occurred in 270 of 1387 patients (19.5%) allocated to a supraglottic airway device and 342 of 1364 patients (25.1%) assigned to a tracheal tube (absolute difference -5.6% (95%CI -8.7 to -2.5), risk ratio 0.78 (95%CI 0.67-0.89); p < 0.001). Among otherwise healthy older patients undergoing elective surgery under general anaesthesia with intra-operative positive pressure ventilation of their lungs, there were fewer postoperative pulmonary complications when the airway was managed with a supraglottic airway device compared with a tracheal tube.

[Association of outdoor artificial light at night exposure with overweight and obesity among children and adolescents aged 9 to 18 years in China].

OBJECTIVE: To analyze the association between outdoor artificial light-at-night (ALAN) exposure and overweight and obesity among children and adolescents aged 9 to 18 years in China. METHODS: Using follow-up data of 5 540 children and adolescents aged 9 to 18 years conducted from November 2019 to November 2020 in eight provinces of China, latitude and longitude were determined based on school addresses, and the mean monthly average nighttime irradiance at the location of 116 schools was extracted by the nearest neighbor method to obtain the mean outdoor ALAN exposure [unit: nW/(cm2·sr)] for each school. Four indicators of overweight and obesity outcomes were included: Baseline overweight and obesity, persistent overweight and obesity, overweight and obesity progression and overweight and obesity incidence. Mixed effects Logistic regression was used to explore the association between ALAN exposure levels (divided into quintiles Q1-Q5) and baseline overweight and obesity, persistent overweight and obesity, overweight and obesity progression and overweight and obesity incidence. In addition, a natural cubic spline function was used to explore the exposure response association between ALAN exposure (a continuous variable) and the outcomes. RESULTS: The prevalence of baseline overweight and obesity, persistent overweight and obesity, overweight and obesity progression and overweight and obesity incidence among the children and adolescents in this study were 21.6%, 16.3%, 2.9% and 12.8%, respectively. The OR value for the association between ALAN exposure and baseline overweight and obesity was statistically significant when ALAN exposure levels reached Q4 or Q5, 1.90 (95%CI: 1.26-2.86) and 1.77 (95%CI: 1.11-2.83), respectively, compared with the children and adolescents in the Q1 group of ALAN exposure. Similar to the results for baseline overweight and obesity, the OR values for the association with persistent overweight and obesity were 1.89 (95%CI: 1.20-2.99) and 1.82 (95%CI: 1.08-3.06) when ALAN exposure levels reached Q4 or Q5, respectively, but none of the OR values for the association between ALAN and overweight and obesity progression and overweight and obesity incidence were statistically significant. Fitting a natural cubic spline function showed a non-linear trend between ALAN exposure and persistent overweight and obesity. CONCLUSION: There is a positive association between ALAN exposure and overweight and obesity in children and adolescents, and the promotion of overweight obesity in children and adolescents by ALAN tends to have a cumulative effect rather than an immediate effect. In the future, while focusing on the common risk factors for overweight and obesity in children and adolescents, there is a need to improve the overweight and obesity-causing nighttime light exposure environment.

[Application and research progress of autologous soft tissue substitute materials in gingival augmentation of natural teeth].

Subepithelial connective tissue or free gingival grafts are often used in traditional mucogingival surgery to treat gingival recession and keratinized gingival insufficiency. However, due to the disadvantages of autologous soft tissue grafts, such as the preparation of the second surgical site, the limited amount of tissue in the donor site, and postoperative discomfort for patients, the research on autologous soft tissue substitute materials has attracted extensive attention. A variety of donor-substitute materials from different sources are currently used in membranous gingival surgeries, including platelet-rich fibrin, acellular dermal matrix, xenogeneic collagen matrix, etc. This paper reviews the research progress and application of several different types of substitute materials in soft tissue augmentation for natural teeth, providing a reference for the application of autologous soft tissue substitutes in clinical gingival augmentation surgery.

[Trend of age of menarche among Chinese Han girls aged 9 to 18 years from 2010 to 2019].

Objective: To analyze the trends of the age of menarche among Chinese Han girls aged 9 to 18 years from 2010 to 2019. Methods: Data were extracted from the Chinese National Surveys on Students' Constitution and Health in 2010, 2014 and 2019. A total of 253 037 Han girls aged 9 to 18 years with complete data on menarche were selected in this study. They were asked one-on-one about their menstrual status, age and residence information. The median age of menarche was estimated by probability regression. U tests were used to compare the difference in median age at menarche in different years. Results: The median age at menarche (95%CI) among Chinese Han girls was 12.47 (12.09-12.83) years in 2010, 12.17 (11.95-12.38) years in 2014 and 12.05 (10.82-13.08) years in 2019, respectively. Compared with that in 2010, the median age at menarche in 2019 decreased by 0.42 years (U=-77.27, P<0.001). The annual average changes were -0.076 years from 2010 to 2014 (U=-57.19, P<0.001) and -0.023 years from 2014 to 2019 (U=-21.41, P<0.001), respectively. The average annual changes in urban areas in the periods of 2010 to 2014 and 2014 to 2019 were -0.071 years and 0.006 years, respectively, while those in rural areas were -0.082 years and -0.053 years, respectively. The average annual changes in the regions of north, northeast, east, south central, southwest and northwest were -0.064, -0.099, -0.091, -0.080, -0.096 and -0.041 years in the period of 2010 to 2014 and 0.001, -0.040, -0.002, -0.005, -0.043 and -0.081 years in the period of 2014 to 2019. Conclusion: The age of menarche among Chinese Han girls aged 9 to 18 years shows an advanced trend from 2010 to 2019, and the trends in urban and rural areas and different regions have different characteristics.

[Perceived exercise benefits and barriers and their association with physical activity time in Chinese Han children and adolescents aged 9 to 18 years].

Objective: To analyze the perceived exercise benefits and barriers and their association with physical activity time in Chinese Han children and adolescents aged 9-18 years. Methods: Data were extracted from the 2019 Chinese National Survey on Students' Constitution and Health and a total of 163 656 children and adolescents aged 9-18 years in Han ethnic group were included in the analysis. Mann-Whitney U test and Kruskal-Wallis test were used to compare the perceived exercise benefits score, perceived exercise barriers score and perceived exercise benefits to barriers ratio in the children and adolescents with different demographic characteristics and physical activity time. The differences in physical activity time in subgroups were compared with χ2 tests. log-binomial regression model was used to evaluate the association between physical activity time and perceived exercise benefits and barriers. Results: The M (Q1,Q3) of the perceived exercise benefits score, perceived exercise barriers score, and perceived exercise benefits to barriers ratio in the children and adolescents were 4.11 (3.78, 4.78), 2.70 (2.10, 3.20) and 1.55 (1.22, 2.07), respectively. Children and adolescents living in urban area, boys, those at younger age and those with physical activity time ≥1 hour had higher perceived exercise benefits score and perceived exercise benefits to barriers ratio, but lower perceived exercise barriers score (all P<0.001). The prevalence of physical activity time ≥1 hour was 41.4% in the children and adolescents. In the log-binomial model with two variables of perceived exercise benefits score and perceived exercise barriers score, for each 1-point increase in the perceived exercise benefits, the possibility of physical activity time ≥1 hour increased by 11% (OR=1.11, 95%CI: 1.10-1.12), and for each 1-point increase in the perceived exercise barriers, the possibility of physical activity time ≥1 hour decreased by 15% (OR=0.85, 95%CI: 0.84-0.85). In the log-binomial model with variable of perceived exercise benefits to barriers ratio, for each 1-point increase in the perceived exercise benefits to barriers ratio, the possibility of physical activity time ≥1 hour increased by 12% (OR=1.12, 95%CI: 1.11-1.12). Conclusion: The perceived exercise benefits and barriers are significantly associated with physical activity time in children and adolescents in China.

[Comparison of leadless pacemaker and conventional pacemaker for quality of life improvement in patients with bradyarrhythmias].

Objective: To compare the improvement in quality of life (QoL) after implantation of leadless pacemakers (L-PM) with that of conventional pacemakers (C-PM) in patients with slow-onset arrhythmias. Methods: A total of 112 patients who received pacemaker implantation for the first time at Beijing Anzhen Hospital from January 2020 to July 2021 were selected, including 50 leadless pacemakers (L-PM) and 62 conventional pacemakers (C-PM). Clinical baseline data were collected, pacemaker-related complications and SF-36 scores were recorded and followed up at 1, 3, and 12 months post-operatively; SF-36 questionnaires and additional questionnaires were completed to compare the quality of life of the 2 groups; and factors associated with the change in QoL from baseline to 1, 3 and 12 months post-operatively were analyzed using multiple linear regression models. Results: The age of the 112 patients was (70.3±10.5) years, and 69 patients (61.6%) were male. The age of patients with L-PM and C-PM was (75.8±8.5) years and (67.5±10.4) years, respectively (P=0.004). In the L-PM group, 50 patients completed 1-, 3-, and 12-month follow-up. In the C-PM group, 62 patients completed the 1-month and 3-month follow-up, and 60 completed the 12-month follow-up. The C-PM group had a higher incidence of discomfort in the surgical area, impact of daily activities for the discomfort in the surgical area, and concern about heart or overall condition than the L-PM group on the additional questionnaire (all P values<0.05). After adjusting for age and SF-36 scores at baseline, at 12th month of follow-up, patients implanted with C-PM had lower values for quality of life PF, RP, SF, RE, and MH scores compared to patients implanted with L-PM, with beta values (95%CI) of -24.500 (-30.010--18.981), -27.118 (-32.997--21.239), -8.085 (-12.536--3.633), -4.839 (-9.437--0.241), -12.430 (-18.558--6.301), respectively (all P values<0.05). Conclusions: L-PM is associated with better QoL in slow arrhythmias patients, and patients who received L-PM reported less activity limitations due to surgical discomfort and less emotional distress.

[Trends of age of menarche among Chinese Han girls aged 9 to 18 years from 2010 to 2019].

Objective: To analyze the trends of the age of menarche among Chinese Han girls aged 9 to 18 years from 2010 to 2019. Methods: Data were extracted from the Chinese National Surveys on Students' Constitution and Health in 2010, 2014 and 2019. A total of 253 037 Han girls aged 9 to 18 years with complete data on menarche were selected in this study. They were asked one-on-one about their menstrual status, age and residence information. The median age of menarche was estimated by probability regression. U tests were used to compare the difference in median age at menarche in different years. Results: The median age at menarche (95%CI) among Chinese Han girls was 12.47 (12.09-12.83) years in 2010, 12.17 (11.95-12.38) years in 2014 and 12.05 (10.82-13.08) years in 2019, respectively. Compared with that in 2010, the median age at menarche in 2019 decreased by 0.42 years (U=-77.27, P<0.001). The annual average changes were-0.076 years from 2010 to 2014 (U=-57.19, P<0.001) and-0.023 years from 2014 to 2019 (U=-21.41, P<0.001), respectively. The average annual changes in urban areas in the periods of 2010 to 2014 and 2014 to 2019 were-0.071 years and 0.006 years, respectively, while those in rural areas were-0.082 years and-0.053 years, respectively. The average annual changes in the regions of north, northeast, east, south central, southwest and northwest were-0.064, -0.099, -0.091, -0.080, -0.096 and-0.041 years in the period of 2010 to 2014 and 0.001, -0.040, -0.002, -0.005, -0.043 and-0.081 years in the period of 2014 to 2019. Conclusion: The age of menarche among Chinese Han girls aged 9 to 18 years shows an advanced trend from 2010 to 2019, and the trends in urban and rural areas and different regions have different characteristics.

[Prevalence trend of high normal blood pressure and elevated blood pressure in Chinese Han children and adolescents aged 7-17 years from 2010 to 2019].

Objective: To investigate the prevalence trend of high normal blood pressure and elevated blood pressure in children and adolescents aged 7 to 17 years in China from 2010 to 2019. Methods: Students aged 7-17 years were selected from the Chinese National Survey on Students' Constitution and Health from 2010 to 2019. High normal blood pressure and elevated blood pressure were determined according to the "Reference of screening for elevated blood pressure among children and adolescents aged 7-18 years" (WS/T 610-2018). The Chi-square test was performed to determine whether there was a difference in the prevalence of high normal blood pressure and elevated blood pressure by gender, residence and age group. Results: In 2019, the prevalence of high normal blood pressure in children and adolescents aged 7-17 years was 15.3% (29 855/195 625), which was higher in boys (20.2%, 19 779/97 847) and rural areas (15.4%, 15 066/97 567) than that in girls (10.3%, 10 076/97 778) and urban areas (15.1%, 14 789/98 058), respectively (all P<0.05). The prevalence of elevated blood pressure was 13.0% (25 377/195 625), which was higher in girls (13.2%, 12 925/97 778) and rural areas (14.1%, 13 753/97 567) than that in boys (12.7%, 12 452/97 847) and urban areas (11.9%, 11 624/98 058) (all P<0.05). From 2010 to 2019, the prevalence of high normal blood pressure showed an increasing trend, with an annual average growth rate from 1.14% to 3.18%. The overall prevalence of elevated blood pressure also showed an increasing trend from 2010 to 2019 but decreased in 2014. The annual average growth rate of elevated blood pressure was-1.07% from 2010 to 2014 and 9.33% from 2014 to 2019. About 17 provinces had an increasing trend in the prevalence of elevated blood pressure from 2010 to 2014, and 22 provinces with an increasing trend from 2014 to 2019. There were obvious regional differences in the annual average growth rate of the prevalence of high normal blood pressure and elevated blood pressure. The regions with the highest annual average growth rate of the prevalence of high normal blood pressure were the Northeast (5.47%) from 2010 to 2014 and the Western region (5.21%) from 2014 to 2019. For elevated blood pressure, the Northeast had the highest annual average growth rate from 2010 to 2014 (12.35%), while the Central (15.79%) and Western (12.87%) had the highest growth rate from 2014 to 2019. Conclusion: From 2010 to 2019, the prevalence of high normal blood pressure and elevated blood pressure in Chinese Han children and adolescents aged 7 to 17 shows an increasing trend, with regional disparities.