The interfaces introduced in metals by heterostructural design play crucial roles in mechanical behaviors. Here the effect of gradient interfaces on mechanical behavior was investigated in a ...laminated Cu–30Zn sample composed of coarse-grained and ultrafine-grained layers. Tensile tests revealed a superior strength-ductility synergy with extraordinary strengthening and work hardening. By combining the measurements of height contour and strain distribution using digital image correlation, the development of strain gradient was detected in the near-interface zone during tension, which was caused by the mechanical incompatibilities across interfaces and the synergetic constraint between layers. The intensity of strain gradient in the near-interface zone increased with tensile strain, which was accommodated by the accumulation of geometrically necessary dislocations, thereby resulting in extra back stress and dislocation strengthening.
•Gradient interface in CG/UFG laminate leads to extra strengthening and hardening.•Gradient interface accommodates the strain incompatibility by accumulating strain gradient.•The development of 3D strain gradient around interface is quantitatively visualized.•GNDs accumulation around interface is theoretically derived and experimentally verified.•Gradient interface leads to extra dislocation and back stress strengthening.
A high performance Cu-Cr-Zr alloy with an ultimate tensile strength of 612 MPa, a uniform elongation of 5% and an electrical conductivity of 84.7% IACS was achieved by the severe rotary swaging and ...two-step peak-aging treatment. A perfect ultrafine grained microstructure with uniformly distributed nano-precipitates was identified to be responsible for the excellent properties of the studied alloy. The proposed method of rotary swaging in combination with the two-step aging treatment shows good potential for producing the high performance Cu-Cr-Zr alloy, which can not only fulfill the industrial requirement of strength and electrical conductivity, but also is suitable for mass production.
TOC: A composite gel polymer electrolyte based on hydroxyethyl cellulose (HEC) and poly (vinylidene fluoride) (PVDF) with sandwich-like architecture exhibiting high safety, good mechanical property ...is prepared and characterized.
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•A new composite HEC-PVDF gel polymer electrolyte with sandwich-like structure is prepared.•Its mechanical strength is largely improved compared with that of hydroxyethyl cellulose.•Its ionic conductivity and lithium ion transference number are greatly increased.•Li//LiFePO4 cell based this gel polymer electrolyte exhibits excellent performance.
A sandwich structure-like PVDF/HEC/PVDF polymer membrane is reported as host for matrix of gel polymer electrolytes for lithium ion batteries. The inner HEC (hydroxyethyl cellulose) layer is compact, and can avoid micro short-circuits. The producibility of the composite membrane is guaranteed due to the simple and efficient electro-spinning process for manufacturing the PVDF (poly(vinylidene fluoride)) layer and low-cost and eco-friendly HEC layer. This structure integrates the advantages of the HEC and PVDF, and it presents high uptake of liquid electrolyte (135.4%), excellent retention of liquid electrolyte, high ionic conductivity (0.88mScm−1 at ambient temperature), low activation energy for lithium movement (0.016eV), and high lithium ion transference number (t+=0.57), all properties are superior to those of the pure HEC membrane and commercial polyolefin separator (Celgard 2730). With the PVDF/HEC/PVDF gel polymer electrolyte as the electrolyte and separator, the assembled Li//LiFePO4 cell exhibits a notably high discharge capacity (140mAhg−1) over 140 cycles. The PVDF and HEC components are non-combustible, which is in sharp contrast with the combustible polymers for the commercial separators. These results show that this kind of sandwiched gel polymer electrolyte is promising for scale-up of lithium ion batteries especially those needing high safety and reliability.
Increasing evidence suggests a close association between early sexual maturation (SM) and obesity in girls and female adults. Earlier maturing girls are more likely to be obese than nonearly ...maturers. However, limited research has been conducted in boys.
To examine the influence of early SM on fatness in boys and compare it with girls, and to test the hypothesis that the associations differ by gender because of the differences in growth and SM patterns in boys and girls.
Cross-sectional study.
One thousand five hundred one girls and 1520 boys (aged 8-14 years) who participated in the Third National Health and Nutrition Examination Survey survey (1988-1994) and had complete anthropometry (weight, height, skinfold thickness) and SM data.
Based on each individual's age and SM status (Tanner stages: genitalia stages for boys and breast stages for girls), the subjects were classified as: 1) early maturers (those who reached a certain Tanner stage earlier than the median age for that stage), and 2) the others (average and later maturers). Overweight was defined as a body mass index (BMI) > or =85th percentile, and obesity > or =95th percentile. Logistic regression analysis was to test how early maturation affected the risks for overweight and obese. Using multiple linear regression models, the associations between fatness (BMI and skinfold thickness) and SM were systematically examined. Covariates including age, ethnicity, residence, family income, energy intake, and physical activity were adjusted.
Early SM was positively associated with overweight and obesity in girls, but the associations were reverse for boys. The prevalence of overweight in early maturers versus the others was 22.6% versus 31.6% in boys and 34.4% versus 23.2% in girls; the figures for obesity were 6.7% versus 14.8% and 15.6% versus 8.1%, respectively. Odd ratios and 95% confidence intervals for obesity were 0.4 (0.2, 0.8) for boys and 2.0 (1.1, 3.5) for girls, and covariates were adjusted. Most significant differences in overweight and obesity among ethnic groups disappeared after controlling for SM. Fatness (BMI and skinfold thickness) was associated with SM stages and with early maturation in boys and girls, but the associations were in opposite directions. Compared with their counterparts, early maturing boys were thinner, whereas early maturing girls were fatter.
Obesity is associated with sexual maturation in both boys and girls, but the association differs. There is positive association in girls, but a negative one in boys. Maturation status should be taken into consideration when assessing child and adolescent obesity.
Background Obesity has become a worldwide epidemic. Recently WHO acknowledged an urgent need to examine child obesity across countries using a standardized international standard. Studies in adults ...find obesity and socioeconomic factors (SES) factors are correlated, but results are inconsistent for children. Using an international standard, we examined the prevalence of obesity and compared the associations between SES factors and obesity across countries. Methods Data for children aged 6–18 from nationwide surveys in the US (NHANES III, 1988–1994), China (1993), and Russia (1992) were used. We used the recently updated US NCHS body mass index (BMI = wt/ht2) reference to define obesity (BMI ≥95th percentile) and overweight (85th≤BMI<95th percentile). The WHO recommends an early version of the NCHS reference for international use. We conducted logistic analyses to examine the relationship between SES and obesity. Results The prevalence of obesity and overweight was 11.1% and 14.3%, respectively, in the US, 6.0% and 10.0% in Russia, and 3.6% and 3.4% in China. The relationship between obesity and SES varied across countries. Higher SES subjects were more likely to be obese in China and Russia, but in the US low-SES groups were at a higher risk. Obesity was more prevalent in urban areas in China but in rural areas in Russia. Conclusions Child obesity is becoming a public health problem worldwide, but the prevalence of obesity varies remarkably across countries with different socioeconomic development levels. Different SES groups are at different risks, and the relationship between obesity and SES varies across countries.
•ADHD occurs in 5.9 % of youth and 2.5 % of adults.•Most cases of ADHD are caused by the combined effects of many genetic and environmental risks.•There are small differences in the brain between ...people with and without ADHD.•Untreated ADHD can lead to many adverse outcomes.•ADHD costs society hundreds of billions of dollars each year, worldwide.
Misconceptions about ADHD stigmatize affected people, reduce credibility of providers, and prevent/delay treatment. To challenge misconceptions, we curated findings with strong evidence base.
We reviewed studies with more than 2000 participants or meta-analyses from five or more studies or 2000 or more participants. We excluded meta-analyses that did not assess publication bias, except for meta-analyses of prevalence. For network meta-analyses we required comparison adjusted funnel plots. We excluded treatment studies with waiting-list or treatment as usual controls. From this literature, we extracted evidence-based assertions about the disorder.
We generated 208 empirically supported statements about ADHD. The status of the included statements as empirically supported is approved by 80 authors from 27 countries and 6 continents. The contents of the manuscript are endorsed by 366 people who have read this document and agree with its contents.
Many findings in ADHD are supported by meta-analysis. These allow for firm statements about the nature, course, outcome causes, and treatments for disorders that are useful for reducing misconceptions and stigma.
To improve the clinical outcome of adoptive NK cell therapy in patients with solid tumors, NK cells need to persist within the tumor microenvironment (TME) in which the abundance of ROS could dampen ...antitumor immune responses. In the present study, we demonstrated that IL-15-primed NK cells acquired resistance against oxidative stress through the thioredoxin system activated by mTOR. Mechanistically, the activation of thioredoxin showed dependence on localization of thioredoxin-interacting protein. We show that NK cells residing in the tumor core expressed higher thiol densities that could aid in protecting other lymphocytes against ROS within the TME. Furthermore, the prognostic value of IL15 and the NK cell gene signature in tumors may be influenced by tobacco smoking history in patients with non-small-cell lung cancer (NSCLC). Collectively, the levels of reducing antioxidants in NK cells may not only predict better tumor penetrance but potentially even the immune therapy response.
Background. Few studies have assessed the association between hypertension and risk of detailed causes of death. We investigated the association between hypertension and all-cause mortality and 67 ...causes of death in a large cohort. Methods. Multivariable Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for self-reported hypertension vs. no hypertension and mortality. Adults aged ≥18 years (n=213798) were recruited in 1997-2004 and followed through December 31, 2006. Results. During 5.81 years of follow-up, 11254 deaths occurred. Self-reported hypertension vs. no hypertension was associated with increased risk of all-cause mortality (HR=1.25, 95% CI: 1.19-1.31) and mortality from septicemia (HR =1.66, 1.06-2.59), other infectious parasitic diseases (HR=2.67, 1.09-6.51), diabetes mellitus (HR=1.97, 1.45-2.67), circulatory disease (HR=1.49, 1.37-1.61), hypertensive heart disease (HR=3.23, 2.00-5.20), ischemic heart disease (HR=1.35, 1.23-1.49), acute myocardial infarction (HR=1.50, 1.27-1.77), other chronic ischemic heart diseases (HR=1.35, 1.17-1.56), all other forms of heart disease (HR=1.51, 1.21-1.89), primary hypertension and renal disease (HR=3.11, 1.82-5.30), cerebrovascular disease (HR=1.64, 1.37-1.97), other circulatory system diseases (HR=1.71, 1.09-2.69), other chronic lower respiratory diseases (HR=1.39, 1.12-1.73), other chronic liver disease (HR=1.89, 1.06-3.37), renal failure (HR=1.91, 1.33-2.74), motor vehicle accidents (HR=1.60, 1.07-2.37), and all other diseases (HR =1.30, 1.10-1.54), but with lower risk of uterine cancer (HR=0.37, 95% CI: 0.15-0.90) and Alzheimer’s disease (HR=0.65, 95% CI: 0.47-0.92). Conclusion. Hypertension was associated with increased risk of all-cause mortality and 17 out of 67 causes of death, with most of these being circulatory disease outcomes, however, some of the remaining associations are unlikely to be causal. Further studies are needed to clarify associations with less common causes of death and potential causality across outcomes.
Energy saving and efficient drying model play important role in the extraction of high quality Chinese medicinal materials. In this work, the gastrodia elata was subjected to hot air drying of ...revealing the drying characteristics with the medicinal indicator of gastrodin ingredient. The multiple drying variables of drying temperature, air velocity, slice thickness and relative humidity were taken into account. Based on the experimental results, an optimized multi-variable model was established to predict the characteristics of drying the sliced gastrodia elata with hot air. The experimental results show that the optimal model of the Page model enables to predict the water loss process of the sliced gastrodia elata under multiple drying variables. The optimal drying variables were determined based on the maximum gastrodin content, of which the temperature was 60 °C, air velocity was 3.5 m/s, slice thickness was 0.4 cm and relative humidity was 25 %. Meanwhile, the drying quality was improved efficiently. The effective diffusion coefficient of gastrodia elata in the hot air drying ranged from 2.254 × 10−9 m2/s to 3.241 × 10−8 m2/s, and the dry activation energy was 34.16 kJ/mol.
•A multi-variable model for the drying behavior of the gastrodia elata with hot air was established.•The effects of drying variables on the characteristics of gastrodia elata were tested and analyzed.•The change of the effective medicinal ingredient of gastrodin in the drying process was revealed.•The optimal drying variables were determined to obtain the maximum gastrodin content.
Objective: To study the secular trends in the disparity of obesity across socioeconomic status (SES) groups among U.S. adults.
Research Methods and Procedures: We used national representative data ...collected in the National Health and Nutrition Examination Surveys conducted in 1971 to 1974, 1976 to 1980, 1988 to 1994, and 1999 to 2000 from 28, 543 adults 20 to 60 years old. Obesity was defined based on BMI calculated using measured weight and height. Trends in the relationship between obesity and education levels were analyzed controlling for age, gender, and ethnicity.
Results: The disparity in obesity across SES (less than high school, high school, and college or above to indicate low, medium, and high SES, respectively) has decreased over the past 3 decades. In National Health and Nutrition Examination Surveys I (1971 to 1974), there was as much as a 50% relative difference in the obesity prevalence across the three groups, but by 1999 to 2000, it decreased to 14%. This trend was more pronounced in women. The trends of diminishing disparities in obesity were also revealed by our logistic and linear regression analyses. The odds ratio converged to 1 from the 1970s to 2000. In most sociodemographic groups, the relationship between BMI and SES (coefficients) has been weakened over time.
Discussion: The association between SES and obesity has been weakened over the past 3 decades, when the prevalence of obesity increased dramatically. There are considerable variations in the changes in the associations across gender and ethnic groups. Our findings suggest that individual characteristics are not likely the main cause of the current obesity epidemic in the U.S., whereas social‐environmental factors play an important role. Strategies for obesity prevention and management should target all SES groups from a societal perspective.
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