中印数字服务贸易国际竞争力比较研究

随着新一轮产业革命的兴起,数字经济强势崛起,数字服务贸易在中国对外贸易总额中所占的比例不断增加。为进一步明确中国数字服务贸易的长短板,挖掘新的增长潜力,文章基于中国和印度两国数字服务进出口数据,构建TC指数和RCA指数,对比分析两国数字服务贸易发展情况,为此提出提升中国数字服务贸易国际竞争力的相关措施。

Dietary Enteromorpha polysaccharide-Zn supplementation regulates amino acid and fatty acid metabolism by improving the antioxidant activity in chicken

Background:Enteromorpha prolifera(E.prolifera)polysaccharide has become a promising feed additive with a variety of physiological activities,such as anti-oxidant,anti-cancer,anti-diabetic,immunomodulatory,hypolipidemic,and cation chelating ability.However,whether Enteromorpha polysaccharide-trace element complex supplementation regulates amino acid and fatty acid metabolism in chicken is largely unknown.This study was conducted to investigate the effects of E.prolifera polysaccharide(EP)-Zn supplementation on growth performance,amino acid,and fatty acid metabolism in chicken.Methods:A total of 184 one-day-old Ross-308 broiler chickens were randomly divided into two treatment groups with 8 replicates,12 chickens per replicate,and fed either the basal diet(control group)or basal diet plus E.prolifera polysaccharide-Zinc(400 mg EP-Zn/kg diet).Results:Dietary EP-Zn supplementation significantly increased(P<0.05)the body weight,average daily gain,muscle antioxidant activity,serum HDL level,and reduced serum TG and LDL concentration.In addition,dietary EPZn supplementation could modulate ileal amino acid digestibility and upregulate the mRNA expression of amino acid transporter genes in the jejunum,ileum,breast muscle,and liver tissues(P<0.05).Compared with the control group,breast meat from chickens fed EP-Zn had higher(P<0.05)Pro and Asp content,and lower(P<0.05)Val,Phe,Gly,and Cys free amino acid content.Furthermore,EP-Zn supplementation upregulated(P<0.05)the mRNA expressions of mTOR and anti-oxidant related genes,while down-regulated protein degradation related genes in the breast muscle.Breast meat from EP-Zn supplemented group had significantly lower(P<0.05)proportions ofΣn-3 PUFA,and a higher percentage ofΣn-6 PUFA and the ratio of n-6/n-3 PUFA.Besides,EP-Zn supplementation regulated lipid metabolism by inhibiting the gene expression of key enzymes involved in the fatty acid synthesis and activating genes that participated in fatty acid oxidation in the liver tissue.Conclusions:It is concluded that EP-Zn complex supplementation regulates apparent ileal amino acid digestibility,enhances amino acid metabolism,and decreases oxidative stress-associated protein breakdown,thereby improving the growth performance.Furthermore,it promotes fatty acid oxidation and restrains fat synthesis through modulating lipid metabolism-related gene expression.

Reversible transformation between terrace and step sites of Pt nanoparticles on titanium under CO and O_(2) environments

Understanding the dynamic evolution of active sites of supported metal catalysts during catalysis is fundamentally important for improving its performance,which attracts tremendous research interests in the past decades.There are two main surficial structures for metal catalysts:terrace sites and step sites,which exhibit catalytic activity discrepancy during catalysis.Herein,by using in situ transmission electron microscopy and in situ Fourier transform infrared spectroscopy(FTIR),the transformation between surface terrace and step sites of Pt-TiO_(2) catalysts was studied under CO and O_(2) environments.We found that the{111}step sites tend to form at{111}terrace under O_(2) environment,while these step sites prefer to transform into terrace under CO environment at elevated temperature.Meanwhile,quantitative ratios of terrace/step sites were obtained by in situ FTIR.It was found that this transformation between terrace sites and step sites was reversible during gas treatment cycling of CO and O_(2).The selective adsorption of O_(2) and CO species at different sites,which stabilized the step/terrace sites,was found to serve as the driving force for active sites transition by density functional theory calculations.Inspired by the in situ results,an enhanced catalytic activity of Pt-TiO_(2) catalysts was successfully achieved through tuning surface-active sites by gas treatments.

Hepatic lipid metabolism is affected by a daily 3-meal pattern with varying dietary crude protein with a pig model

The present study was conducted to evaluate the effects of 3 meals administered daily with varying dietary crude protein(CP)contents on hepatic lipid metabolism with a pig model.Pigs were divided into3 groups according to the following feeding patterns:feeding a basal CP diet 3 times daily(3 C);feeding a high CP diet for breakfast,the basal CP diet for lunch,and a low CP diet for dinner(HCL);and feeding the low CP diet for breakfast,the basal CP diet for lunch,and the high protein diet for dinner(LCH).Three groups took equivalent diet per meal ensuring that every pig was fed with similar dietary formulae daily.Results showed that HCL feeding pattern reduced the relative kidney weight(P<0.05),and LCH feeding pattern increased the relative liver weight of pigs(P<0.05)when compared with those in the 3 C group.Plasma urea nitrogen(P<0.01)and lipase(P<0.05)decreased in the HCL group but increased in the LCH group.Both HCL and LCH feeding patterns reduced plasma triglycerides(P<0.01),non-esterified fatty acids(NEFA)(P<0.01),and hepatic crude fat(0.05<P<0.10)of pigs.Real-time quantitative PCR(RTqPCR)results showed that dynamic feeding patterns down-regulated(P<0.05)the mRNA level of lipid metabolism related genes,including adipose triglyceride lipase(ATGL),acetyl-CoA carboxylase(ACCa),liver X receptor(LXRα)in the liver,and negatively regulate elements of circadian clock,including period 1(Perl),period 2(Per2),cryptochrome(Cry2),which in turn,upregulated(P<0.05)the protein expression of positive regulate element brain and muscle Arnt-like 1(BMAL1)when compared with 3 C group.Overall,our findings suggested that dynamic feeding patterns may affect hepatic lipid metabolism via regulation of the circadian clock.