[Association of single nucleotide polymorphisms of transcription factors with congenital heart diseases in the Chinese population: a Meta analysis].

OBJECTIVE: To study the association of single nucleotide polymorphisms (SNPs) of transcription factors (NKX2.5, GATA4, TBX5, and FOG2) with congenital heart disease (CHD) in the Chinese population. METHODS: PubMed, Google Scholar, CNKI, Wanfang Data, and Weipu Data were searched for articles on the association of SNPs of target genes with CHD in the Chinese population. If one locus was mentioned in at least two articles, the random or fixed effect model was used to perform a pooled analysis of study results and to calculate the pooled OR and its 95%CI. If a locus was mentioned in only one article, related data were extracted from this article to analyze the association between the SNPs of this locus and CHD. RESULTS: Twenty-three articles were included. The Meta analysis showed that there were significant differences between the CHD and control groups in the genotype and allele frequencies of GATA4 rs1139244 and rs867858 and the genotype frequency of GATA4 rs904018, while there were no significant differences in the SNPs of the other genetic loci between the two groups. The single-article analysis showed that there were significant differences between the two groups in the allele frequencies of NKX2.5 rs118026695/rs703752, GATA4 rs884662/rs12825/rs12458/rs3203358/rs4841588, and TBX5 rs6489956. There were no significant differences in the SNPs of FOG2 locus between the two groups. CONCLUSIONS: The SNPs of some loci in NKX2.5, GATA4, and TBX5 are associated with CHD in the Chinese population, but the association between the SNPs of FOG2 locus and the development of CHD has not been found yet.

Worldwide prevalence of adverse pregnancy outcomes associated with in vitro fertilization/intracytoplasmic sperm injection among multiple births: a systematic review and meta-analysis based on cohort studies.

PURPOSE: To perform a systematic review and meta-analysis of reported estimates of adverse pregnancy outcomes among multiple births conceived with in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI). METHODS: PubMed, Google Scholar, Cochrane Libraries and Chinese databases were searched through May 2016 for cohort studies assessing adverse pregnancy outcomes associated with IVF/ICSI multiple births. Random-effects meta-analyses were used to calculate pooled estimates of adverse pregnancy outcomes and, where appropriate, heterogeneity was explored in group-specific analyses. RESULTS: Sixty-four studies, with 60,210 IVF/ICSI multiple births and 146,737 spontaneously conceived multiple births, were selected for analysis. Among IVF/ICSI multiple births, the pooled estimates were 51.5% [95% confidence interval (CI): 48.7-54.3] for preterm birth, 12.1% (95% CI: 10.4-14.1) for very preterm birth, 49.8% (95% CI: 47.6-52.0) for low birth weight, 8.4% (95% CI: 7.1-9.9) for very low birth weight, 16.2% (95% CI: 12.9-20.1) for small for gestational age, 3.0% (95% CI: 2.5-3.7) for perinatal mortality and 4.7% (95% CI: 4.0-5.6) for congenital malformations. When the data were restricted to twins, the pooled estimates also showed a high prevalence of adverse outcomes. There was a similar prevalence of poor outcomes among multiple births conceived with IVF/ICSI and naturally (all P ≥ 0.0792). Significant differences in different continents, countries, and income groups were found. CONCLUSIONS: The IVF/ICSI multiple pregnancies have a high prevalence of adverse pregnancy outcomes. However, population-wide prospective adverse outcomes registries covering the entire world population for IVF/ICSI pregnancies are needed to determine the exact perinatal prevalence.

Worldwide prevalence of adverse pregnancy outcomes among singleton pregnancies after in vitro fertilization/intracytoplasmic sperm injection: a systematic review and meta-analysis.

PURPOSE: The worldwide prevalence of adverse pregnancy outcomes (APOs) in singleton pregnancies after in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) is suggested to vary; however, a complete overview is missing. The aim of this review is to estimate the worldwide prevalence of APOs associated with IVF/ICSI singleton pregnancies. METHODS: PubMed, Google Scholar, Cochrane Libraries, and Chinese databases were searched for studies assessing APOs among IVF/ICSI singleton births through March 2016. The prevalence estimates were summarized and analyzed by meta-analysis. RESULTS: Fifty-two cohort studies, with 181,741 IVF/ICSI singleton births and 4,636,508 spontaneously conceived singleton births, were selected for analysis. Among IVF/ICSI singleton pregnancies, pooled estimates were 10.9% [95% confidence interval (CI) 10.0-11.8] for preterm birth, 2.4% (95% CI 1.9-3.0) for very preterm birth, 8.7% (95% CI 7.4-10.2) for low birth weight, 2.0% (95% CI 1.5-2.6) for very low birth weight, 7.1% (95% CI 5.5-9.2) for small for gestational age, 1.1% (95% CI 0.9-1.3) for perinatal mortality, and 5.7% (95% CI 4.7-6.9) for congenital malformations. The IVF/ICSI singleton pregnancies have higher prevalence of APOs compared with those conceived naturally (all P = 0.000). Significant differences in different continents, countries, income groups, and type of assisted conception were found. CONCLUSIONS: The IVF/ICSI singleton pregnancies are at a higher prevalence of adverse perinatal outcomes compared with those conceived naturally. Important geographical differences were found. Yet, population-wide prospective APO registries covering the entire world population for IVF/ICSI pregnancies are needed to determine the exact perinatal prevalence.

Single-dose intra-articular bupivacaine plus morphine versus bupivacaine alone after arthroscopic knee surgery: a meta-analysis of randomized controlled trials.

PURPOSE: The purpose of this meta-analysis was to compare the efficacy and safety of single-dose intra-articular bupivacaine plus morphine versus bupivacaine alone for pain management following arthroscopic knee surgery. METHOD: A comprehensive literature search was conducted to identify randomized controlled trials that used single-dose intra-articular bupivacaine plus morphine and bupivacaine alone for post-operative pain, using MEDLINE (1966-2014), Cochrane Library and EMBASE databases. The weighted mean difference (WMD), relative risk (RR) and their corresponding 95 % confidence intervals (CIs) were calculated using RevMan statistical software. RESULT: A total of twenty-nine trials (n = 1167) were included. The post-operative visual analog scale (VAS) pain score of the bupivacaine plus morphine group compared with the bupivacaine alone group was significantly lower (WMD -1.15, 95 % CI -1.67 to -0.63, p < 0.0001). As far as safety, there was no significant difference in side effects between the two groups (RR 1.10, 95 % CI 0.59-2.04, n.s.). Sensitivity analyses suggested that the results of these two primary outcomes were stable and reliable. However, the current evidence did not suggest a superior effect with respect to the time to first analgesic request (WMD 51.33, 95 % CI -110.99 to 213.65, n.s.) and the number of patients requiring supplementary analgesia (RR 1.13, 95 % CI 0.92-1.39, n.s.). CONCLUSIONS: On the basis of the currently available literature, this study is the first to suggest that single-dose intra-articular bupivacaine plus morphine was shown to be significantly better than bupivacaine alone at relieving post-operative pain after arthroscopic knee surgery without increasing the short-term side effects. Routine use of single-dose intra-articular bupivacaine plus morphine is an effective way for pain management after arthroscopic knee surgery. LEVEL OF EVIDENCE: II.

Association between serum selenium level and type 2 diabetes mellitus: a non-linear dose-response meta-analysis of observational studies.

BACKGROUND: The association between serum selenium levels and type 2 diabetes mellitus (T2DM) is controversial. We performed a systematic review and non-linear dose-response meta-analysis of observational studies to investigate the association in the present study. METHODS: A comprehensive literature search was conducted using MEDLINE and EMBASE databases. A pooled odds ratio (OR) and related 95 % confidence interval (95 % CI) for T2DM between the highest and lowest serum selenium categories, and a non-linear dose-response relationship between selenium and T2DM were estimated. RESULTS: A total of five studies (of 13,460 participants) were identified as meeting the inclusion criteria. The pooled OR indicated that there was a significantly higher prevalence of T2DM in the highest category of blood selenium compared with the lowest (OR = 1.63, 95 % CI: 1.04-2.56, P = 0.033). Moreover, a significant non-linear dose-response relationship was observed between serum selenium levels and T2DM (P < 0.001). Serum selenium levels were positively associated with T2DM in populations with relatively low serum selenium levels (<97.5 µg/l) and those with high serum selenium levels (>132.5 µg/l). CONCLUSIONS: The positive association between serum selenium levels and T2DM existed in populations with relatively low levels and high levels of serum selenium, indicating a likely U-shaped non-linear dose-response relationship between serum selenium and T2DM.

Guidelines for Developing and Reporting Machine Learning Predictive Models in Biomedical Research: A Multidisciplinary View.

BACKGROUND: As more and more researchers are turning to big data for new opportunities of biomedical discoveries, machine learning models, as the backbone of big data analysis, are mentioned more often in biomedical journals. However, owing to the inherent complexity of machine learning methods, they are prone to misuse. Because of the flexibility in specifying machine learning models, the results are often insufficiently reported in research articles, hindering reliable assessment of model validity and consistent interpretation of model outputs. OBJECTIVE: To attain a set of guidelines on the use of machine learning predictive models within clinical settings to make sure the models are correctly applied and sufficiently reported so that true discoveries can be distinguished from random coincidence. METHODS: A multidisciplinary panel of machine learning experts, clinicians, and traditional statisticians were interviewed, using an iterative process in accordance with the Delphi method. RESULTS: The process produced a set of guidelines that consists of (1) a list of reporting items to be included in a research article and (2) a set of practical sequential steps for developing predictive models. CONCLUSIONS: A set of guidelines was generated to enable correct application of machine learning models and consistent reporting of model specifications and results in biomedical research. We believe that such guidelines will accelerate the adoption of big data analysis, particularly with machine learning methods, in the biomedical research community.

Single-dose intra-articular ropivacaine after arthroscopic knee surgery decreases post-operative pain without increasing side effects: a systematic review and meta-analysis.

PURPOSE: The purpose of this study was to appraise the efficacy and safety of single-dose intra-articular ropivacaine administered for pain relief after arthroscopic knee surgery. METHODS: PubMed, Embase, and Cochrane Library databases were searched in October 2014 to identify randomized controlled trials of single-dose intra-articular ropivacaine for post-operative pain relief. Post-operative pain intensity, the amount of rescue analgesia required, and side effects including local anaesthetic toxicity were assessed. The relative risk (RR), the weighted mean difference (WMD), and their corresponding 95 % confidence intervals (CIs) were calculated. RESULTS: Eight randomized controlled trials were included in the analysis. Statistically significant differences in the visual analogue scale for pain intensity value were observed during the immediate post-operative period (WMD -10.35, 95 % CI -17.12 to -3.59, p = 0.003) and the early post-operative period (WMD -11.90, 95 % CI -18.12 to -5.69, p = 0.0002), but not during the late post-operative period (WMD -2.89, 95 % CI -7.46 to 1.68, n.s.). There was no significant difference in the amount of rescue analgesia required (RR 0.76, 95 % CI 0.52-1.11, n.s.). Only two trials reported the incidence of drug-related side effects (including nausea and vomiting): the incidence in the ropivacaine groups was no higher than that in the control groups. Only one trial assessed local anaesthetic toxicity as an outcome, but it was not detected. CONCLUSIONS: Single-dose intra-articular ropivacaine administered at the end of arthroscopic knee surgery provides effective pain relief in the immediate and early post-operative periods without increasing short-term side effects.

A semi-supervised tensor regression model for siRNA efficacy prediction.

BACKGROUND: Short interfering RNAs (siRNAs) can knockdown target genes and thus have an immense impact on biology and pharmacy research. The key question of which siRNAs have high knockdown ability in siRNA research remains challenging as current known results are still far from expectation. RESULTS: This work aims to develop a generic framework to enhance siRNA knockdown efficacy prediction. The key idea is first to enrich siRNA sequences by incorporating them with rules found for designing effective siRNAs and representing them as enriched matrices, then to employ the bilinear tensor regression to predict knockdown efficacy of those matrices. Experiments show that the proposed method achieves better results than existing models in most cases. CONCLUSIONS: Our model not only provides a suitable siRNA representation but also can predict siRNA efficacy more accurate and stable than most of state-of-the-art models. Source codes are freely available on the web at: http://www.jaist.ac.jp/\~bao/BiLTR/ .

The association between dietary selenium intake and diabetes: a cross-sectional study among middle-aged and older adults.

BACKGROUND: Selenium is an important trace element for human health. Although numerous epidemiological and interventional studies have examined the association between selenium and diabetes, their findings have been inconclusive. Moreover, no research has specifically focused on the association between dietary selenium and diabetes in the Asian population. The objective of this study was to evaluate the relationship between dietary selenium and diabetes in middle-aged and elderly Chinese adults. METHODS: A cross-sectional study including 5,423 subjects was carried out. The basic characteristics, biochemical test results, and dietary intake were collected from each subject for analysis. The adjusted odds ratio (OR) and the corresponding 95% confidence interval (CI) were used to determine the relationship between dietary selenium intake and diabetes through logistic regression. RESULTS: The prevalence of diabetes in the study population was 9.7%, and the average level of dietary selenium intake was 43.51 µg/day. The multivariate adjusted OR was 1.52 (95% CI: 1.01 to 2.28, P = 0.04) for the highest quartile of dietary selenium intake in comparison with the lowest quartile. There was a significant positive association between dietary selenium intake and diabetes (P for trend = 0.03). CONCLUSION: There was a significant positive correlation between dietary selenium intake and the prevalence of diabetes.

Binding properties of palmatine to DNA: spectroscopic and molecular modeling investigations.

Palmatine, an isoquinoline alkaloid, is an important medicinal herbal extract with diverse pharmacological and biological properties. In this work, spectroscopic and molecular modeling approaches were employed to reveal the interaction between palmatine and DNA isolated from herring sperm. The absorption spectra and iodide quenching results indicated that groove binding was the main binding mode of palmatine to DNA. Fluorescence studies indicated that the binding constant (K) of palmatine and DNA was ~ 10(4)L·mol(-1). The associated thermodynamic parameters, ΔG, ΔH, and ΔS, indicated that hydrogen bonds and van der Waals forces played major roles in the interaction. The effects of chemical denaturant, thermal denaturation and pH on the interaction were investigated and provided further support for the groove binding mode. In addition to experimental approaches, molecular modeling was conducted to verify binding pattern of palmatine-DNA.

Risk factors for congenital syphilis and adverse pregnancy outcomes in offspring of women with syphilis in Shenzhen, China: a prospective nested case-control study.

BACKGROUND: Despite existence of a highly effective intervention, maternal syphilis still causes substantial perinatal morbidity and mortality, even in China, where antenatal health services are strong. This study sought to address personal, programmatic, and other risk factors for congenital syphilis (CS) and adverse pregnancy outcomes (APOs) among pregnant women in Shenzhen, China. METHODS: Pregnant women attending antenatal services were offered serologic tests, and those diagnosed as having syphilis were recruited from April 2007 to October 2012. In a nested case-control study for the pregnancy outcomes of syphilis-infected women, we assessed risk factors comparing infants born with CS (group II) and with any APOs (group III) to infants without CS or APOs (group I). RESULTS: During the 66-month study period, we screened 279,334 pregnant women and identified 838 (0.3%; 95% confidence interval, 0.28%-0.32%) women infected with syphilis. Among infants born to syphilitic mothers, 8.2% (34/417) were diagnosed as having CS and 24.7% (103/417) were diagnosed as having APOs. Compared with group I, maternal baseline titers of nontreponemal antibodies (adjusted odds ratio [aOR], 2.13), stage of syphilis (aOR, 21.56), length of time between the end of the first treatment to childbirth (aOR, 11.93), gestational week at treatment (aOR, 2.63), and fathers' cocaine use (aOR, 15.44) and syphilis infection status (aORpositive vs. negative, 5.84; aORunknown vs. negative, 5.55) were positively associated with CS, but prenatal care (aOR, 0.11) and complete treatment (aOR, 0.20) were negatively associated with CS. Maternal age (aOR, 1.43), marriage (aOR, 2.41), history of cocaine use (aOR, 3.79) and ectopic pregnancy (aOR, 5.91), baseline titers of nontreponemal antibodies (aOR, 1.30), stage of syphilis (aOR, 8.89), length of time between the end of the first treatment to childbirth (aOR, 2.52), gestational week at treatment (aOR, 1.78), and fathers' syphilis infection status (aORunknown vs. negative, 2.02) were also positively associated with APOs, but maternal history of syphilis (aOR, 0.44), prenatal care (aOR, 0.29), and complete treatment (aOR, 0.25) were negatively associated with APOs, CONCLUSIONS: Syphilis was an important cause of pregnancy loss and infant disability, particularly among women who did not receive prenatal care or had late or inadequate treatment. These study results can inform antenatal programs on the importance of early syphilis testing and prompt and appropriate treatment. Some strategies targeted at other risk factors areas may be helpful.

Computational study on ice growth inhibition of Antarctic bacterium antifreeze protein using coarse grained simulation.

Antarctic bacterium antifreeze proteins (AFPs) protect and support the survival of cold-adapted organisms by binding and inhibiting the growth of ice crystals. The mechanism of the anti-freezing process in a water environment at low temperature of Antarctic bacterium AFPs remains unclear. In this research, we study the effects of Antarctic bacterium AFPs by coarse grained simulations solution at a temperature range from 262 to 273 K. The results indicated that Antarctic bacterium AFPs were fully active in temperatures greater than 265 K. Additionally, the specific temperature ranges at which the water molecules become completely frozen, partially frozen, and not frozen were identified.

Data mining for materials design: a computational study of single molecule magnet.

We develop a method that combines data mining and first principles calculation to guide the designing of distorted cubane Mn(4+)Mn3(3+) single molecule magnets. The essential idea of the method is a process consisting of sparse regressions and cross-validation for analyzing calculated data of the materials. The method allows us to demonstrate that the exchange coupling between Mn(4+) and Mn(3+) ions can be predicted from the electronegativities of constituent ligands and the structural features of the molecule by a linear regression model with high accuracy. The relations between the structural features and magnetic properties of the materials are quantitatively and consistently evaluated and presented by a graph. We also discuss the properties of the materials and guide the material design basing on the obtained results.

Single-dose intra-articular bupivacaine after knee arthroscopic surgery: a meta-analysis of randomized placebo-controlled studies.

PURPOSE: The purpose of this meta-analysis was to examine the efficacy and safety of single-dose intra-articular bupivacaine in the management of pain after knee arthroscopic surgery. METHOD: The comprehensive literature search, using MEDLINE, the Cochrane Central Register of Controlled Trials, and Embase databases, was conducted to identify randomized controlled trials that used single-dose intra-articular bupivacaine for postoperative pain. The relative risk (RR), weighted mean difference (WMD), and their corresponding 95 % confidence intervals (CIs) were calculated using RevMan(®) statistical software. RESULT: Twenty-three studies (n = 1287) were included (647 subjects in bupivacaine group and 640 subjects in the control group). Statistically significant differences were observed in the VAS values (WMD -1.1; 95 % CI -1.7 to -0.5), number of patients requiring supplementary analgesia (RR 0.83; 95 % CI 0.74-0.94), and time to first analgesic request (WMD 129.3; 95 % CI 15.4-243.1) among the bupivacaine group when compared to the control group. However, short-term side effects had no significant difference between these two groups (RR 0.73; 95 % CI 0.44-1.24). CONCLUSIONS: On the basis of the currently available literature, single-dose intra-articular bupivacaine was shown to be significantly better than placebo at relieving pain after knee arthroscopic surgery. More high-quality randomized controlled trials with long follow-up are highly required for examining the safety of single-dose intra-articular bupivacaine. Besides, routine use of single-dose intra-articular bupivacaine is still an effective way for pain management after knee arthroscopic surgery.

The influence of the tibial plateau slopes on injury of the anterior cruciate ligament: a meta-analysis.

PURPOSE: The purpose of this meta-analysis was (1) to examine the effect of the tibial plateau slopes (medial and lateral) on anterior cruciate ligament (ACL) injury and (2) to investigate gender differences between ACL-injured subjects and gender-matched controls. METHODS: The PubMed database was searched through to 1 November 2011 to identify studies that met pre-stated inclusion criteria. Reference lists of retrieved articles were also reviewed. Two authors independently extracted information on the designs of the studies, the characteristics of the study participants, exposure and outcome assessments, and control for potential confounding factors. A meta-analysis was conducted, and either a fixed- or a random-effects model was used to calculate the overall weighted mean difference (WMD). RESULTS: Twelve studies (n = 1,871: 923 patients in the ACL-injured group and 938 patients in the control group) were included. The medial tibial plateau slope in the ACL group ranged from 1.8° ± 3.7° to 12.1° ± 3.3° while it ranged from 2.9° ± 2.8° to 9.5° ± 3° among the controls. The lateral tibial plateau slope in the ACL ranged from 1.8° ± 3.2° to 11.5° ± 3.5° and 0.3° ± 3.6° to 9° ± 4° in the control group. Statistically significant increased angles were observed in ACL-injured group compared to control group for medial tibial plateau slope (WMD, 1.1°; 95 % confidence interval, 0.5°-1.7°) and lateral tibial plateau slope (WMD, 1.8°; 95 % confidence interval, 1.3°-2.3°). Sensitivity analysis and subgroup analysis proved this to be a reliable result. CONCLUSIONS: The current meta-analysis suggests that both, increased medial and lateral tibial plateau slopes, are associated with increased susceptibility to ACL injury regardless of gender. In addition, this study indicates a stronger evidence for lateral tibial plateau slope to be associated with ACL injury compared with medial tibial plateau slope due to the larger increased angle value and on the basis of consistency among the included studies.

The influence of the intercondylar notch dimensions on injury of the anterior cruciate ligament: a meta-analysis.

PURPOSE: The aim of this meta-analysis was to examine the effect of the intercondylar notch dimensions, intercondylar notch width index (NWI) and intercondylar notch width (NW), separately in anterior cruciate ligament (ACL) injury. METHODS: The PubMed and Wanfang database were searched through until 1 November 2011 to identify studies that met pre-stated inclusion criteria. Reference lists of retrieved articles were also reviewed. Two authors independently extracted information on the designs of the studies, the characteristics of the study participants, exposure and outcome assessments and control for potential confounding factors. Either a fixed- or a random-effects model was used to calculate the overall weighted mean difference (WMD). RESULTS: Sixteen studies (n = 4,291) were included (1,222 subjects in ACL-injured group and 3,069 subjects in the control group). Statistically significant differences were observed in the NWI (WMD, -0.02; 95 % confidence interval, -0.04 to -0.01), and in the NW (WMD, -2.15; 95 % confidence interval, -3.09 to -1.21) among the ACL-injured group when compared to the control group. CONCLUSION: The meta-analysis findings concluded that narrow intercondylar notch dimensions were associated with the risk of ACL injury. A lower NWI or NW stenosis predisposes an individual to ACL injury. Further original studies should include more anatomical risk factors that could be associated with the risk of ACL injury.

[Current situation and cause analysis of physical activity in Chinese primary and middle school students in 2010].

OBJECTIVE: To analyze the characteristics of physical activity in Chinese primary and middle school students, and to provide scientific basis for school physical education and health work. METHODS: The data were collected from 166 812 Han primary school pupils above grade 4, junior and senior middle school students who participated in 2010 National Physical Fitness and Health Surveillance in 30 provinces (excluding autonomous regions, municipalities). RESULTS: Nationwide in 2010, 22.7% of the students had been physically active doing any kind of physical activity for a total of at least 60 minutes per day, the prevalence rates of the 9 to 13, 13 to 16, 16 to 19 age groups were 32.7%, 20.7% and 12.5%, respectively (P<0.01). The prevalence of having been physically active for a total of at least 60 minutes per day was higher among the Eastern Region's students than the Western Region's students in the different age groups (P<0.05), of whom 61.8% reported that they sweated and felt a little bit tired in physical education, 68.6% thought that they liked their physical education, 72.4% were willing to take part in extracurricular physical activities organized by their school, and 46.4% were willing to participate in the long distance running exercise. "Fear of fatigue or/and hardship" was the most important reason why the students did not actively participate in physical activities and long-distance running exercise among both the boys and girls in the different age groups. CONCLUSION: The prevalence of having been physically active for a total of at least 60 minutes per day in Chinese students is still low, and there is an obvious difference in the different groups. In the future, not only should the students' physical exercise time and intensity be further guaranteed, but also their awareness strengthened and their habits of physical exercise cultured.

[Analysis of current situation of physical activity and influencing factors in Chinese primary and middle school students in 2010].

OBJECTIVE: To find out the current situation of physical activity and its influencing factors among Chinese primary and middle school students. METHODS: A total of 166 812 students aged 9 - 18 finished the questionnaires of physical activities and lifestyle behaviors who were selected from "2010 National Physical Fitness and Health Surveillance". The subjects were sampled by stratified cluster sampling method in 30 provinces (autonomous regions, municipalities) except Tibet. The physical activity for a total of at least 60 minutes per day, attitudes on physical activity, parents' supports toward physical activity of children, development of school physical education, the schoolwork burden and sedentary lifestyle were all analyzed. Logistic regression was used to analyze the association between the physical activity for a total of at least 60 minutes per day and individual, family, school and sedentary behavior. RESULTS: A total of 22.7% (37 867/166 757) of primary and middle school students aged 9 - 18 had been physically active doing any kind of physical activity for a total of 60 minutes or more per day, the prevalence was higher among male (25.4%, 21 086/83 159) than female (20.1%, 16 781/83 598) students (P < 0.05). In the 9 - 12 age group, the prevalence was higher among urban (37.6%, 5 980/15 912) than rural (32.0%, 4 917/15 375) students (P < 0.05), but in the 16 - 18 age group, the case was opposite. The prevalence of doing physical activity for a total of 60 minutes or more per day among students who liked physical education (23.7%, 11 866/50 073), were willing to participate in the extracurricular sports activities (23.2%, 13 460/57 907), and were willing to participate long running exercise (26.9%, 9 185/34 153) was higher than those who dislike physical education (15.9%, 589/3705), were not willing to participate in the extracurricular sports activities (15.9%, 567/3565), and were not willing to participate long running exercise (12.1%, 2 246/18 493), respectively. The prevalence was higher among students whose parents supported their physical activity (20.4%, 15 148/74 312) than those students without parents' support (17.5%, 1626/9270) (P < 0.05). And the prevalence was higher among students whose parents often took part in the physical activity (22.7%, 12 864/56 769) than those students whose parents did not (14.6%, 3 906/26 780) (P < 0.05). Logistic regression analysis (adjusted sex, age and urban or not) demonstrated that variables associated with physical activity for a total of 60 minutes or more per day were the initiative will on the physical activity and parental physical activity (OR: 1.478, 95%CI: 1.398 - 1.562). The students without adequate physical education class in school were less likely to do physical activity for a total of 60 minutes or more per day than those who with adequate physical education class in school (OR: 0.536, 95%CI: 0.523 - 0.550), and the students in the school with the phenomenon of "crowding out" or "no" physical education were less likely to do physical activity for a total of 60 minutes or more per day than those whose school without these with phenomenon (OR: 0.712, 95%CI: 0.666 - 0.761). The heavy homework burden (OR: 0.926, 95%CI: 0.899 - 0.953) and long homework time (OR: 0.879, 95%CI: 0.853 - 0.906) were reversely related to the physical activity. CONCLUSION: The prevalence of having been physically active for a total of 60 minutes per day in Chinese students is still low. The strong initiative will on the physical activity, parental physical activity, and better school sports atmosphere are good for students to carry out physical activity, and the students with the heavy homework burden and long homework time are less likely to take part in the physical activity.

Improving sentiment analysis on clinical narratives by exploiting UMLS semantic types.

Sentiments associated with assessments and observations recorded in a clinical narrative can often indicate a patient's health status. To perform sentiment analysis on clinical narratives, domain-specific knowledge concerning meanings of medical terms is required. In this study, semantic types in the Unified Medical Language System (UMLS) are exploited to improve lexicon-based sentiment classification methods. For sentiment classification using SentiWordNet, the overall accuracy is improved from 0.582 to 0.710 by using logistic regression to determine appropriate polarity scores for UMLS 'Disorders' semantic types. For sentiment classification using a trained lexicon, when disorder terms in a training set are replaced with their semantic types, classification accuracies are improved on some data segments containing specific semantic types. To select an appropriate classification method for a given data segment, classifier combination is proposed. Using classifier combination, classification accuracies are improved on most data segments, with the overall accuracy of 0.882 being obtained.

Sequence-dependent histone variant positioning signatures.

BACKGROUND: Nucleosome, the fundamental unit of chromatin, is formed by wrapping nearly 147bp of DNA around an octamer of histone proteins. This histone core has many variants that are different from each other by their biochemical compositions as well as biological functions. Although the deposition of histone variants onto chromatin has been implicated in many important biological processes, such as transcription and replication, the mechanisms of how they are deposited on target sites are still obscure. RESULTS: By analyzing genomic sequences of nucleosomes bearing different histone variants from human, including H2A.Z, H3.3 and both (H3.3/H2A.Z, so-called double variant histones), we found that genomic sequence contributes in part to determining target sites for different histone variants. Moreover, dinucleotides CA/TG are remarkably important in distinguishing target sites of H2A.Z-only nucleosomes with those of H3.3-containing (both H3.3-only and double variant) nucleosomes. CONCLUSIONS: There exists a DNA-related mechanism regulating the deposition of different histone variants onto chromatin and biological outcomes thereof. This provides additional insights into epigenetic regulatory mechanisms of many important cellular processes.