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Adolescence is an important phase of development during which youth experience dramatic neurobiological, cognitive, and psychosocial changes. Decades of research have demonstrated gender similarities and differences during adolescence. This chapter takes both a gender perspective and a sociocultural perspective to understand adolescent development. For each of the following seven areas of adolescent development, we summarize latest research findings on gender similarities and differences in diverse cultures (e.g., North America, Europe, Africa, and Asia). We then particularly focus on singleton adolescent girls’ and boys’ development under the One-Child Policy in China as a case in point of sociocultural influences on gendered development during adolescence. Future directions of both theoretical and methodological concerns are discussed.
A suite of Jurassic–Cretaceous migmatites was newly identified in the Liaodong Peninsula of the eastern North China Craton (NCC). Anatexis is commonly associated with crustal thickening. However, the newly identified migmatites were formed during strong lithospheric thinning accompanied by voluminous magmatism and intense deformation. Field investigations show that the migmatites are spatially associated with low-angle detachment faults. Numerous leucosomes occur either as isolated lenses or thin layers (dykes), parallel to or cross-cutting the foliation. Peritectic minerals such as titanite and sillimanite are distributed mainly along the boundaries of reactant minerals or are accumulated along the foliation. Most zircons show distinct core–rim structures, and the rims have low Th/U ratios (0.01–0.24). Zircon U–Pb dating results indicate that the protoliths of the migmatites were either the Late Triassic (224–221 Ma) diorites or metasedimentary rocks deposited sometime after c. 1857 Ma. The zircon overgrowth rims record crystallization ages of 173–161 Ma and 125 Ma, which represent the formation time of leucosomes. These ages are consistent with those reported magmatic events in the Liaodong Peninsula and surrounding areas. The leucosomes indicate a strong anatectic event during the Jurassic–Cretaceous period. Partial melting occurred through the breakdown of muscovite and biotite with the presence of water-rich fluid under a thermal anomaly regime. The possible mechanism that caused the 173–161 Ma and 125 Ma anatectic events was intimately related to the regional crustal extension during the lithospheric thinning of the NCC. Meanwhile, the newly generated melts further weakened the rigidity of the crust and enhanced the extension.
Data on average iodine requirements for the Chinese population are limited following implementation of long-term universal salt iodisation. We explored the minimum iodine requirements of young adults in China using a balance experiment and the ‘iodine overflow’ hypothesis proposed by our team. Sixty healthy young adults were enrolled to consume a sequential experimental diet containing low, medium and high levels of iodine (about 20, 40 and 60 μg/d, respectively). Each dose was consumed for 4 d, and daily iodine intake, excretion and retention were assessed. All participants were in negative iodine balance throughout the study. Iodine intake, excretion and retention differed among the three iodine levels (P < 0·01 for all groups). The zero-iodine balance derived from a random effect model indicated a mean iodine intake of 102 μg/d, but poor correlation coefficients between observed and predicted iodine excretion (r 0·538 for μg/d data) and retention (r 0·304 for μg/d data). As iodine intake increased from medium to high, all of the increased iodine was excreted (‘overflow’) through urine and faeces by males, and 89·5 % was excreted by females. Although the high iodine level (63·4 μg/d) might be adequate in males, the corresponding level of 61·6 μg/d in females did not meet optimal requirements. Our findings indicate that a daily iodine intake of approximately half the current recommended nutrient intake (120 μg/d) may satisfy the minimum iodine requirements of young male adults in China, while a similar level is insufficient for females based on the ‘iodine overflow’ hypothesis.
The link between schizophrenia and cigarette smoking has been well established through observational studies. However, the cause–effect relationship remains unclear.
We conducted Mendelian randomisation analyses to assess any causal relationship between genetic variants related to four smoking-related traits and the risk of schizophrenia.
We performed a two-sample Mendelian randomisation using summary statistics from genome-wide association studies (GWAS) of smoking-related traits and schizophrenia (7711 cases, 18 327 controls) in East Asian populations. Single nucleotide polymorphisms (SNPs) correlated with smoking behaviours (smoking initiation, smoking cessation, age at smoking initiation and quantity of smoking) were investigated in relation to schizophrenia using the inverse-variance weighted (IVW) method. Further sensitivity analyses, including Mendelian randomisation-Egger (MR-Egger), weighted median estimates and leave-one-out analysis, were used to test the consistency of the results.
The associated SNPs for the four smoking behaviours were not significantly associated with schizophrenia status. Pleiotropy did not inappropriately affect the results.
Cigarette smoking is a complex behaviour in people with schizophrenia. Understanding factors underlying the observed association remains important; however, our findings do not support a causal role of smoking in influencing risk of schizophrenia.
To determine which set of BMI cut-offs is the most appropriate to define child and adolescent obesity in urban China.
A cross-sectional study was carried out between 1 November and 31 December in 2017.
Community Healthcare Center in Minhang District, Shanghai, China.
A total of 12 426 children and adolescents aged 7–17 years were selected by cluster random sampling. Bioelectrical impedance analysis was the gold standard to measure body composition.
Comparisons of three sets of BMI cut-offs by sensitivity and κ value revealed that the Working Group on Obesity in China (WGOC) (sensitivity 39·9–84·0 %; κ 0·51–0·79) and WHO (sensitivity 25·5–74·5 %; κ 0·35–0·78) cut-offs were not superior to the International Obesity Task Force (IOTF) (sensitivity 47·9–92·4 %; κ 0·58–0·85) cut-offs across all subgroups. The WGOC and WHO cut-offs yielded higher misclassification rates, in the worst case, categorising 11·2 % of girls with high adiposity as normal and 44·4 % of them as overweight, while the IOTF cut-offs categorised 2·3 % as normal and 30·7 % as overweight. Individuals who were classified by the IOTF cut-offs as overweight had the lowest ratios of high adiposity (4·2–41·6 %) than by the BMI cut-offs for each subgroup. Among pubertal girls, none of the BMI-based cut-offs indicated excellent agreement with body fat percentage, and κ value of the WHO cut-offs (0·35 (95 % CI 0·29, 0·41)) was lower than the other two sets of BMI cut-offs (all P < 0·001).
The IOTF cut-offs for Asian should be recommended for child obesity screening in urban China. Pubertal individuals need a more accurate indicator of obesity screening.
The gut microbiota is directly influenced by dietary components, and it plays critical roles in chronic diseases. Excessive consumption of trans-fatty acids (TFA) is associated with obesity induced by alterations in gut microbiota, but the links between obesity and gut microbiota remain unclear. Therefore, studies examining the impact of TFA on intestinal microflora are essential. In our study, we performed 16S ribosomal RNA gene sequencing on faecal samples from Sprague–Dawley rats fed a basal diet (control (CON) group), high-fat (HF) diet (diet-induced obesity (DIO) group) or TFA diets (1 % TFA group and 8 % TFA group) for 8 weeks to investigate the effects of TFA/HF diets on obesity and gut microbiota composition. We found that the TFA/HF diets significantly induced obesity and changes in blood and brain physiological parameters of the rats. The relative abundance of the phyla Firmicutes and Bacteroidetes was inversely altered in the three test groups compared with the CON group. Proteobacteria increased slightly in the DIO, 1 % TFA and 8 % TFA groups. The genus Bacteroides increased in the DIO and 1 % TFA groups, but Muribaculaceae decreased in all experimental groups compared with the CON group. Moreover, significant differences were observed among clusters of orthologous group functional categories of the four dietary groups. Our observations suggested that the TFA/HF diets induced obesity and dysfunction of gut microbiota. Gut dysbiosis might mediate the obesity effects of TFA/HF diets.
To investigate the association of folic acid (FA) supplementation with birth weight, the risk of small for gestational age (SGA) and low birth weight (LBW) in singleton and twin pregnancy.
A population-based cross-sectional survey.
Twenty counties and ten districts in Shaanxi Province of northwestern China, 2013.
28 174 pregnant women with their infants, covering 27 818 single live births and 356 twin live births.
The prevalence of FA supplementation in singletons and twins was 63·9 and 66·3 %. The mean birth weight was 3267 (sd 459·1) g, 2525 (sd 534·0) g and 2494 (sd 539·5) g; the prevalence of SGA was 14·3, 51·4 and 53·4 %; the prevalence of LBW was 3·4, 42·4 and 46·6 % among singleton, twin A and twin B, respectively. Compared with non-users, women with FA supplementation were (β 17·3, 95 % CI 6·1, 28·4; β 166·3, 95 % CI 69·1, 263·5) associated with increased birth weight, lower risk of SGA (OR 0·85, 95 % CI 0·80, 0·92; OR 0·45, 95 % CI 0·30, 0·68) and LBW (OR 0·82, 95 % CI 0·71, 0·95; OR 0·50, 95 % CI 0·33, 0·75) in singletons and twins, and more prominent effects in twins. Moreover, there were significant interactions between FA supplementation and plurality on birth weight, SGA and LBW.
The present study suggests the association of periconceptional 0·4 mg/d FA supplementation with increased birth weight and reduced risk of SGA and LBW in both singletons and twins, and this association may be more prominent in twins.
Identifying risk factors and mortality of individuals with Alzheimer’s disease (AD) could have important implications for the clinical management of AD.
This pilot study aimed to examine the overall mortality of AD patients over a 10-year surveillance period in Shanghai, China. This study is an extension of our previous investigation on mortality of neurodegenerative diseases.
One hundred and thirty-two AD patients recruited from the memory clinics of two hospitals in Shanghai in 2007 were followed up until December 31, 2017 or death, representing a follow-up period of up to 10 years. Overall standardized mortality ratios (SMRs) were calculated, and predictors for survival at recruitment were estimated.
Sixty-seven patients had died by December 31, 2017, and the SMR at 10 years of follow-up was 1.225 (95% confidence interval 0.944–1.563). Employing Cox’s proportional hazard modeling, lower Mini-Mental State Examination score, and comorbid diabetes predicted poor survival in this cohort.
This pilot study suggests a similar survival trend of patients with AD compared to the general population in Shanghai urban region. Poor cognitive status and comorbid diabetes had a negative impact on the survival of AD patients.
Synaptotagmin 1 (Syt1) is an abundant and important presynaptic vesicle protein that binds Ca2+ for the regulation of synaptic vesicle exocytosis. Our previous study reported its localization and function on spindle assembly in mouse oocyte meiotic maturation. The present study was designed to investigate the function of Syt1 during mouse oocyte activation and subsequent cortical granule exocytosis (CGE) using confocal microscopy, morpholinol-based knockdown and time-lapse live cell imaging. By employing live cell imaging, we first studied the dynamic process of CGE and calculated the time interval between [Ca2+]i rise and CGE after oocyte activation. We further showed that Syt1 was co-localized to cortical granules (CGs) at the oocyte cortex. After oocyte activation with SrCl2, the Syt1 distribution pattern was altered significantly, similar to the changes seen for the CGs. Knockdown of Syt1 inhibited [Ca2+]i oscillations, disrupted the F-actin distribution pattern and delayed the time of cortical reaction. In summary, as a synaptic vesicle protein and calcium sensor for exocytosis, Syt1 acts as an essential regulator in mouse oocyte activation events including the generation of Ca2+ signals and CGE.
A series of xLiMn0.5Fe0.5PO4–yLi3V2(PO4)3/C (x:y= 4:1, 3:1, 2:1, 1:1, 1:2, and 1:3) composite cathode materials for lithium-ion batteries are successfully prepared by the rheological phase reaction method. The structures, morphologies, and electrochemical properties of these composite materials are studied. The results indicate that xLiMn0.5Fe0.5PO4–yLi3V2(PO4)3/C composites are composed of LiMn0.5Fe0.5PO4 and Li3V2(PO4)3 phases and mutual doping exists. The initial discharge capacities, initial Coulombic efficiencies, and capacity retentions of composites increase but then decline with the increase of Li3V2(PO4)3 content. All the composites show higher capacity retentions than LiMn0.5Fe0.5PO4/C and Li3V2(PO4)3/C single phases except LMFP–3LVP/C. The composite material of x:y= 1:1 exhibits remarkably superior electrochemical performance than the single phases and other composites both in discharge capacity and cycle performance, delivering the initial discharge capacity of 148.2 mA h/g (2.0–4.5 V) and 170.1 mA h/g (2.0–4.8 V) at 0.1 C. And the corresponding capacity retentions are 98.0 and 90.4% after 100 cycles, respectively.
Epidemiological data for Toxoplasma gondii regarding malignancy have gained increasing attention; however, the information about T. gondii infection among children with malignant lymphoma (ML) in China is unclear. Therefore, 314 children with lymphoma and 314 healthy children, age- and gender-matched, were recruited to estimate the seroprevalence of T. gondii in the participants and identify the risk factors of infection. Blood samples from all participants were collected and examined for T. gondii IgG and IgM antibodies using ELISA. The results showed that the overall seroprevalence of T. gondii antibodies (including IgG and/or IgM) in ML patients and healthy controls was 19.8% and 9.9%, respectively. Contact with the cats, consumption of oysters and history of chemotherapy were estimated to be the risk factors for T. gondii infection in children with lymphoma by multivariable logistic regression analysis, whereas in healthy children, contact with cats and consumption of oysters were the risk factors. Moreover, among various histological types of lymphoma, individuals with NK/T-cell lymphoma, B-small lymphocytic lymphoma, marginal zone B-lymphoma and Hodgkin's lymphoma had a higher seroprevalence than healthy controls (P < 0.05). These findings indicated the high prevalence of T. gondii infection in children with lymphoma, and hence, efforts should be performed to evaluate the effect of the infection further in lymphoma patients.
A magnetic dipole quasi-Yagi antenna based on a dielectric resonator (DR) is proposed in this letter. The dominate TE1δ1 mode of the rectangular DR is used as a magnetic dipole which can be differentially fed by the coplanar strip line (CPS). Thanks to the DR employment, the proposed antenna has several advantages such as compact size and flexible design which means the 3-D dimensions of the DR can be easily adjusted to cater for various applications. Meanwhile, the gain of the proposed DR quasi-Yagi antenna is higher than that of traditional electric dipole counterparts. Furthermore, since the DR driver is horizontally polarized, both the metal strip and DR can be used as a director for enhancing the end-fire gain. To verify the design concept, a prototype operating at the X-band is fabricated and measured. Good agreement between the simulated and measured results can be observed.
Polypropylene plastic (PP) was chosen as additives for the preparation of activated carbon (AC), considering that PP promotes pore formation during the preparation of AC. When the addition ratio of PP was 20%, AC having a maximum specific surface area of 1916.1 m2/g was prepared. Fourier transform–infrared spectroscopy (FT-IR) analysis exhibited the types of functional groups on the surface of AC, such as–OH, C=O, C–C, and –CH. The SEM analysis revealed the formation of disordered pores over the AC. Furthermore, iodine value of the AC is 1460 mg/g. Additionally, adsorption test revealed the AC is suitable for adsorbing methylene blue (MB). The adsorption equilibrium data of MB onto AC were most suitable for Redlich–Peterson model. The maximum adsorption capacity of the single layer was 476.88 mg/g, indicating that AC has high adsorption capacity. The kinetic data fitted well with the pseudo-second-order model.
Echinococcus granulosus sensu stricto (s.s.), Echinococcus multilocularis and Echinococcus canadensis are the common causes of human echinococcosis in China. An accurate species identification tool for human echinococcosis is needed as the treatments and prognosis are different among species. The present work demonstrates a method for the simultaneous detection of these three Echinococcus species based on multiplex polymerase chain reaction (mPCR). Specific primers of this mPCR were designed based on the mitochondrial genes and determined by extensive tests. The method can successfully detect either separated or mixed target species, and generate expected amplicons of distinct size for each species. Sensitivity of the method was tested by serially diluted DNA, showing a detection threshold as less as 0.32 pg for both E. granulosus s.s. and E. canadensis, and 1.6 pg for E. multilocularis. Specificity assessed against 18 other parasites was found to be 100% except weakly cross-react with E. shiquicus. The assay was additionally applied to 69 echinococcosis patients and 38 healthy persons, confirming the high reliability of the method. Thus, the mPCR described here has high application potential for clinical identification purposes, and can further provide a useful tool for evaluation of serology and imaging method.
The relationship between serum Mg and blood cell counts in Chinese adult diabetes or central obesity was assessed by investigating 8163 subjects with China Health and Nutrition Survey (mean age 59⋅6 years, 54⋅9 % men). Participants were classified according to blood Mg (below 0⋅65 mmol/l, or 0⋅66–0⋅94 mmol/l or above 0⋅95 mmol/l), type 2 diabetes (yes/no) and central obesity (yes/no). Leucocytes, erythrocytes, platelets (PLT), Hb and glycated Hb (HbA1c) were determined using standardised methods and conditions. HbAc1, leucocytes and PLT were significantly higher among subjects with central obesity than without central obesity (P < 0⋅05). A significant increase for Hb, erythrocytes, PLT, but not leucocytes, across progressive Mg groups was observed in subjects without diabetes (P < 0⋅05). Hb, erythrocytes and HbAc1 were significantly higher among subjects with higher Mg than in subjects with lower Mg with diabetes (P < 0⋅05). Central obesity disturbed the positive association between PLT count and serum Mg. Type 2 diabetes caused metabolism disorder in serum Mg, blood sugar and blood cell count. Hb, erythrocytes and PLT, but not leucocytes, are positively correlated with serum Mg, but this association is somehow disturbed by type 2 diabetes or central obesity.
Annexin A2 (ANXA2) is reported to be associated with cancer development. To investigate the roles ANXA2 plays during the development of cancer, the RNAi method was used to inhibit the ANXA2 expression in caco2 (human colorectal cancer cell line) and SMMC7721 (human hepatocarcinoma cell line) cells. The results showed that when the expression of ANXA2 was efficiently inhibited, the growth and motility of both cell lines were significantly decreased, and the development of the motility relevant microstructures, such as pseudopodia, filopodia, and the polymerization of microfilaments and microtubules were obviously inhibited. The cancer cell apoptosis was enhanced without obvious significance. The possible regulating pathway in the process was also predicted and discussed. Our results suggested that ANXA2 plays important roles in maintaining the malignancy of colorectal and hepatic cancer by enhancing the cell proliferation, motility, and development of the motility associated microstructures of cancer cells based on a possible complicated signal pathway.
Hand, foot, and mouth disease (HFMD) is a common infectious disease caused by a group of viruses. The causative viruses have changed over time, and there is a need for a more effective protective vaccine. In this study, we investigated the profiles of human enteroviruses that caused HFMD outbreaks in Nanjing in 2015, with the goal of guiding the future prevention and treatment of HFMD.
Specimens were collected from 1097 patients admitted to our hospital and diagnosed with HFMD. Enteroviruses in the specimens were identified by real-time polymerase chain reaction and epidemiological patterns were analyzed with the clinical data.
Among the 1097 clinically diagnosed HFMD cases, 916 cases were confirmed by laboratory tests. The results showed that the main infectious virus was coxsackievirus A6 (CVA6) (41.75%), followed by enterovirus 71 (EV71) (27.48%), coxsackievirus A16 (7.43%), coxsackievirus A10 (6.84%), and others (16.51%). Further investigation indicated that CVA6 caused mild cases of HFMD, while EV71 caused severe cases. More enterovirus positive cases were reported from rural areas than from urban areas.
CA6 and EV71 were the chief pathogenic viruses of HFMD cases in the present study. Schools, childcare centers, and families from rural areas should be the major targets for prevention and awareness of HFMD. This study will provide information useful in the prevention and management of HFMD and the development of relevant vaccines for HFMD in the future. (Disaster Med Public Health Preparedness. 2019;13:740–744).
Cerebrovascular disease is the most common cause of death in China, and the incidence of ischemic stroke (240 per 100,000 people) is higher than that of hemorrhagic stroke (82 per 100,000 people). More than 80 percent of strokes can be prevented by early control of risk factors. Therefore, identifying and managing high-risk groups is a top priority in preventing stroke. The CHA2DS2-VASc score is a key prediction tool for stratifying stroke risk in individuals with atrial fibrillation (AF) as follows: zero score is low risk; one is intermediate risk; and two is high risk. The present study was undertaken to evaluate the accuracy of the CHA2DS2-VASc scoring system for stratifying ischemic stroke risk in the non-AF population.
We searched PubMed, EMBASE, and the Cochrane Library in June 2018 for relevant diagnostic studies. Study selection, data extraction, and quality assessment (using the QUADAS-2 criteria) were performed independently by two authors. Methodological variation across the selected studies precluded meta-analysis, so the results were synthesized narratively.
Seven prospective studies involving 50,652 patients (6,760 with ischemic stroke) were included. The treatment threshold ranged from two to four across the studies. Three studies reported diagnostic accuracy at a threshold of two, with a sensitivity above 0.8 and a specificity ranging from 0.32 to 0.68. The diagnostic odds ratio was greater than two (seven studies). The two studies using a treatment threshold of four reported a sensitivity of 0.59 to 0.76 and a specificity of 0.43 to 0.69. One study used a threshold of three, with a sensitivity of 0.79 and a specificity of 0.39.
The CHA2DS2-VASc score may be used to predict ischemic stroke in the non-atrial fibrillation population. Treatment thresholds greater than two provide more optimal diagnostic accuracy, although the predictive performance of the CHA2DS2-VASc score may be better in patients with chronic obstructive pulmonary disease but not AF.