The universal strategy to synthesize efficient and cheap metal–free oxygen reduction reaction (ORR) catalysts is extremely urgent for the commercialization of fuel cells (FCs). This work luckily ...meets this by utilizing solo porogen (ZnCO32∙Zn(OH)23) to fabricate fluffy carbon with micro/meso/macropores from 15 kinds of daily biomass. The representative sample NMC–1 performs excellent four–electron ORR activity, delivers onset potential of 0.96 V, half–wave potential of 0.82 V, together with outstanding durability and poison resistance. The precursor can be extended to 15 kinds of biomass substantially confirms ZnCO32∙Zn(OH)23 as solo porogen is a vividly universal protocol to prepare hierarchical carbon as ORR catalysts from low–cost biomass, where the underlying formation mechanism may be based on the two-step decomposition of ZnCO32∙Zn(OH)23 involved in pyrolysis process. Such concise one–porogen method holds promising potential as general approach to synthesizing desirable ORR catalysts from widely available biomass. In addition, the ORR catalytic activity of as-prepared hierarchically porous carbon changes with the increase of the proportion of mesopore and macropore volume and the peak is obtained at 0.76. Therefore, the proportion of mesopore and macropore volume might be applied as one indicator to evaluate the ORR performance of metal-free carbon materials.
A universal approach, basic zinc carbonate as solo porogen with two pore-creating mechanisms, is provided to constantly fabricate fluffy carbon materials with micro-, meso- and macropores from 15 kinds of daily biomass even biowaste (such as carrot, long bean and ginkgo leaf, etc.). In addition, the ORR performance of these hierarchically porous carbon materials is entwined with the proportion of mesopore and macropore volume and the peak is obtained at 0.76. Herein, the proportion of mesopore and macropore volume might be applied as one indicator to reflect the structure–function relationship of metal-free carbon materials as ORR catalysts. The highlight of this universal strategy is both the cost-effective raw materials, which can be widely available in nature, and the powerful pore-creating mechanism, which is active for a variety of biomass. This work opens a general avenue for the synthesis of fluffy carbon materials as ORR catalysts from low-cost biomass, which is believed to be a promising protocol to positively drive fuel cells commercialization scale-up in terms of ORR catalyst. Display omitted
•Basic zinc carbonate as solo porogen with two pore-creating mechanisms can produce carbon with micro-/meso-/macropores.•This powerful pore-creating mechanism is active for a variety of biomass.•The carbon derived from biomass have similar morphology, pore types, pore size distribution and ORR catalytic activity.
Pore size distribution and specific surface area of carbon-based materials are extensively reported to play a key role in catalyzing oxygen reduction reaction (ORR). As far as pore size distribution ...is concerned, carbon materials with the same pore size ranges always show different ORR performances. Why? It is well accepted that there are two coordinates for pore size distribution, horizontal and vertical ones. The former is related to the pore size range and studied maturely, and the latter is closely related to the quantity of any kind of specific pores (including meso-/micro-/macro-pore) contributed to the pore volume or area, i.e., the variation of the vertical coordinate of pore size distribution is closely linked to the variation of the meso-/micro-/macro-pore volumes, which should make great contribution to the mass transfer and density of ORR active sites of carbon materials and never be reported. Herein, this work synthesizes a series of N, P co-doped micro/mesoporous carbon materials with tunable/unalterable/negligible meso-/micro-/macro-pore volumes to pioneer the relationship of the mesopore volume on behalf of the vertical coordinate of pore size distribution with the - mass transfer and ORR active site density of such metal-free heteroatom-doped porous carbon materials and investigate why and how to tailor the coordinates of pore size distribution to construct ORR-active carbon materials i.e., the mass transfer and density of ORR active site are improved via tailoring the vertical coordinate of pore size distribution. We also develop a universal pore-forming strategy for extensively synthesizing carbon materials with expected pore size range (horizontal coordinate) and mesopore volume (vertical coordinate) from widely available biomass in nature to guide the synthesis and selection of carbon-based ORR-active materials to meet the demands of high-performance ORR electrocatalysts.
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•This work pioneers the relationship of mesopore volume with ORR active site density of such metal-free heteroatom-doped porous carbon materials.•The ORR active site density could be improved by tailoring the vertical coordinate of pore size distribution.•A universal pore-forming strategy for extensively synthesizing carbon materials with expected porous structure is developed to meet the demands of high-performance ORR electrocatalysts.
Summary
Objective
This systematic examination and meta‐analysis examined the scope and variation of the worldwide double burden of diseases and identified related socio‐demographic factors.
Design
We ...searched PubMed for studies published in English from January 1, 2000, through September 28, 2016, that reported on double disease burden. Twenty‐nine studies from 18 high‐income, middle‐income and low‐income countries met inclusion criteria and provided 71 obesity–undernutrition ratios, which were included in meta‐regression analysis.
Results
All high‐income countries had a much higher prevalence of obesity than undernutrition (i.e. all the obesity/undernutrition ratios >1); 55% of the ratios in lower middle‐income and low‐income countries were <1, but only 28% in upper middle‐income countries. Meta‐analysis showed a pooled obesity–undernutrition ratio of 4.3 (95% CI = 3.1–5.5), which varied by country income level, subjects' age and over time. The average ratio was higher in high‐income rather than that in lower middle‐income and low‐income countries (β SE = 10.8 2.6), in adults versus children (7.1 2.2) and in data collected since 2000 versus before 2000 (5.2 1.5; all P values < 0.05).
Conclusions
There are considerable differences in the obesity versus undernutrition ratios and in their prevalence by country income level, age groups and over time, which may be a consequence of the cumulative exposure to an obesogenic environment.
Summary
Viral diseases severely affect crop yield and quality, thereby threatening global food security. Genetic improvement of plant virus resistance is essential for sustainable agriculture. In the ...last decades, several modern technologies were applied in plant antiviral engineering. Here we summarized breakthroughs of the two major antiviral strategies, RNA silencing and genome editing. RNA silencing strategy has been used in antiviral breeding for more than thirty years, and many crops engineered to stably express small RNAs targeting various viruses have been approved for commercial release. Genome editing technology has emerged in the past decade, especially CRISPR/Cas, which provides new methods for genetic improvement of plant virus resistance and accelerates resistance breeding. Finally, we discuss the potential of these technologies for breeding crops, and the challenges and solutions they may face in the future.
Summary
Recently, CRISPR‐Cas (clustered, regularly interspaced short palindromic repeats–CRISPR‐associated proteins) system has been used to produce plants resistant to DNA virus infections. However, ...there is no RNA virus control method in plants that uses CRISPR‐Cas system to target the viral genome directly. Here, we reprogrammed the CRISPR‐Cas9 system from Francisella novicida to confer molecular immunity against RNA viruses in Nicotiana benthamiana and Arabidopsis plants. Plants expressing FnCas9 and sgRNA specific for the cucumber mosaic virus (CMV) or tobacco mosaic virus (TMV) exhibited significantly attenuated virus infection symptoms and reduced viral RNA accumulation. Furthermore, in the transgenic virus‐targeting plants, the resistance was inheritable and the progenies showed significantly less virus accumulation. These data reveal that the CRISPR/Cas9 system can be used to produce plant that stable resistant to RNA viruses, thereby broadening the use of such technology for virus control in agricultural field.
China has seen rapid increase in obesity and hypertension prevalence and fast food consumption over the past decade. We examined status and risk factors for Western- and Chinese fast food consumption ...and their associations with health outcomes in Chinese children, and examined how maternal factors were associated with child health outcomes.
Data of 1626 students aged 7-16 (11.6 ± 2.0) years and their parents in four mega-cities across China (Beijing, Shanghai, Nanjing, and Xi'an) were collected in the 2015 baseline survey of the Childhood Obesity Study in China Mega-cities. Weight, height, waist circumference, and blood pressure were measured. Food intake was assessed using questionnaire. Mixed models were used to examine the associations.
Among the children, 11.1% were obese, 19.7% were centrally obese, and 9.0% had hypertension. Obesity prevalence was much higher in boys than in girls (15.2% vs. 6.9% and 27.4% vs. 11.7%, respectively, both P < 0.001). About half (51.9% and 43.6%) of children consumed Western and Chinese fast food, respectively, over the past 3 months. Compared to those with college or above maternal education level, those with elementary school or below maternal education level were 49% more likely to consume Western fast food (odds ratio OR and 95% confidence interval CI: 1.49 1.10-2.03). Chinese fast food consumption rate increased by 12% with each year of increase in child's age (OR and 95% CI: 1.12 1.02-1.23). No significant associations between fast food consumption and health outcomes were detected. Adjusting for Western fast food consumption, children with lower maternal education were 71% and 43% more likely to have obesity and central obesity (ORs and 95% CIs: 1.71 1.12-2.61 and 1.43 1.00-2.03, respectively), and maternal body mass index was positively associated with child obesity, central obesity, and hypertension (ORs and 95% CIs: 1.11 1.06-1.17, 1.12 1.07-1.17, and 1.09 1.03-1.15, respectively). Results were similar when Chinese fast food consumption was adjusted for.
The prevalence of fast food consumption, obesity and hypertension is high among children in major cities in China. Maternal factors affect child outcomes.
Evidence was limited on trajectory of body mass index (BMI) through adulthood and its association with hypertension. We aimed to evaluate their association by sex in large-scale study. Data were ...obtained from the China Health and Nutrition Survey (CHNS) from 1991 to 2015. Latent class trajectory analysis (LCTA) was used to capture BMI change trajectories. Hazard risks (HRs) were estimated from Cox proportion hazard regression. Among 14,262 participants (mean age, 38.8; 47.8% men), 5138 hypertension occurred (2687 men and 2451 women) occurred during a mean follow-up 9.6 years. Four body mass trajectory groups were identified as BMI loss, stable, moderate and substantial gain. Appropriately half of participants (48.0%) followed 1 of the 2 BMI gain trajectories, where BMI increased at least 3 kg/m
overtime. Compared with participants with stable BMI, those gaining BMI substantially had higher risk of hypertension by 65% (HR 1.65, 95% CI 1.45-1.86) in male and 83% (HR 1.83, 95% CI 1.58-2.12) in female. The HRs in BMI loss patterns were 0.74 (0.62-0.89) in men and 0.87 (0.75-1.00) in women. Our findings imply that majority of Chinese adults transited up to a higher BMI level during follow-up. Avoiding excessive weight gain and maintaining stable weight might be important for hypertension prevention.
Radical resection is an effective therapeutic method to increase the survival rate of patients with gallbladder cancer (GBC). In addition to the surgical approach, the relationships between various ...clinicopathologic factors and the outcome of patients with GBC remain controversial.
Clinical and laboratory examination characteristics, pathological and surgical data, and post-operative survival time of 338 patients with advanced GBC who received treatment at the First Affiliated Hospital of Xi'an Jiaotong University, China from January 2008 to December 2012 were analyzed retrospectively. Factors influencing the prognosis of GBC after surgery were analyzed by univariate and multivariate analysis.
The overall survival rates for curative resection patients were significantly greater than those for non-curative resection patients (1-,3-,5-year survival rate and mean-survival time: 59.0%, 47.3%, 44.3% and 22.0 months vs. 12.7%, 8.3%, 7.7% and 3.0 months) (P < 0.001). For the curative resection patients, positive margin, lymph node metastasis, poorly pathological differentiation and the presence of ascites were all independent risk factors for poor prognosis. For patients with T3 stage, neither segmentectomy of IVb and V nor common bile duct resection improved the prognosis (P = 0.867 and P = 0.948). For patients with T4 stage, aggressive curative resection improved the prognosis (P = 0.007).
An advanced T stage does not preclude curative resection. Positive margin, lymph node metastasis, poorly pathological differentiation and the presence of ascites are all independent risk factors for poor prognosis in the curative intent resection patients. The range of liver resection and whether common bile duct resection is performed do not influence the prognosis as long as R0 resection is achieved.
The relationship between lifestyles and multimorbidity is well established, but previous studies have often neglected the role of spatial heterogeneity. Thus, this study is the first to explore this ...association in Chinese adults from a spatial perspective using a geographically weighted logistic regression (GWLR) model and describe the geographical characteristics across different regions. According to 2018 China Health and Retirement Longitudinal Study (CHARLS) database, a total of 7101 subjects were finally included, with 124 prefecture-level administrative regions in China. Non-spatial and GWLR model were used for analysis, and gender stratification analysis was also performed. Data were visualized through ArcGIS 10.7. The results showed that a total prevalence of approximately 5.13% of multimorbidity, and among participants with multimorbidity, the separate prevalence of hypertension, diabetes or high blood sugar, heart disease, and stroke were 4.45%, 2.32%, 3.02%, and 1.41%, respectively. The GWLR model indicated that current (OR: 1.202-1.220) and former smokers (OR: 1.168-1.206) may be important risk factors for multimorbidity in adults, especially in north and west among male. Past drinkers (OR: 1.233-1.240), especially in eastern China, contribute to the development of the multimorbidity in men but not in women. Vigorous-intensity activities (OR: 0.761-0.799) were negatively associated with multimorbidity in the west, with no gender difference. Depression (OR: 1.266-1.293) appeared to increase the risk for multimorbidity, with the weakest effects in central China and no gender difference. There was an interaction between light activities and gender (P = 0.024). The prevalence of multimorbidity differed across various areas of the province. The role of geographical variations in lifestyles and multimorbidity may provide valuable information for developing site-specific intervention strategies.
To evaluate the prevalence and determinants of metabolic syndrome (MetS) among adults in a rural area of Northwest China.
A population-based cross-sectional study was conducted in 2010 among adults ...aged 18 to 80 years in rural areas of Hanzhong, in Northwest China. Interview, physical and clinical examinations, and fasting blood glucose and lipid measurements were completed for 2990 adults. The definitions of MetS proposed by the Third Report of the National Cholesterol Education Program Expert Panel (Adults Treatment Panel III, ATP III) and the International Diabetes Federation (IDF), and the modified ATP III definition for Asian population were used and compared. Proportions were adjusted for age and sex.
The prevalence of MetS was 7.9%, 10.8% and 15.1% according to ATP III, IDF and modified ATP III criteria, respectively. Agreement between ATP III and IDF criteria and that between ATP III and modified ATP III criteria were moderate (Kappa = 0.52 and 0.64, respectively), whereas agreement between IDF and modified ATP III criteria was good (Kappa = 0.83). The prevalence of MetS increased with age, and was higher in women than in men (10.4% versus 5.4%, 13.6% versus 8.1% and 17.4% versus 12.8%, according to ATP III, IDF and modified ATP III criteria, respectively). The most common MetS component was high blood pressure. Having family history of hypertension, lack of physical activity, high economical level, overweight and obesity were positively associated with MetS.
MetS is prevalent among rural adults in Northwest China and high blood pressure is the most common MetS component. Prevention and treatment of hypertension and MetS should be a public health priority to reduce cardiovascular diseases in rural areas of Northwest China. More attention should be given to the elderly, women, people with family history of hypertension and obese people who are at high risk of MetS.
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