Sugarcane/soybean intercropping with reduced nitrogen addition enhances residue-derived labile soil organic carbon and microbial network complexity in the soil during straw decomposition

Sugarcane/soybean intercropping with reduced nitrogen addition is an important sustainable agricultural pattern that can alter soil ecological functions,thereby affecting straw decomposition in the soil.However,the mechanisms underlying changes in soil organic carbon(SOC)composition and microbial communities during straw decomposition under long-term intercropping with reduced nitrogen addition remain unclear.In this study,we conducted an in-situ microplot incubation experiment with^(13)C-labeled soybean straw residue addition in a two-factor(cropping pattern:sugarcane monoculture(MS)and sugarcane/soybean intercropping(SB);nitrogen addition levels:reduced nitrogen addition(N1)and conventional nitrogen addition(N2))long-term experimental field plot.The results showed that the SBN1 treatment significantly increased the residual particulate organic carbon(POC)and residual microbial biomass carbon(MBC)contents during straw decomposition,and the straw carbon in soil was mainly conserved as POC.Straw addition changed the structure and reduced the diversity of the soil microbial community,but microbial diversity gradually recovered with decomposition time.During straw decomposition,the intercropping pattern significantly increased the relative abundances of Firmicutes and Ascomycota.In addition,straw addition reduced microbial network complexity in the sugarcane/soybean intercropping pattern but increased it in the sugarcane monoculture pattern.Nevertheless,microbial network complexity remained higher in the SBN1 treatment than in the MSN1 treatment.In general,the SBN1 treatment significantly increased the diversity of microbial communities and the relative abundance of microorganisms associated with organic matter decomposition,and the changes in microbial communities were mainly driven by the residual labile SOC fractions.These findings suggest that more straw carbon can be sequestered in the soil under sugarcane/soybean intercropping with reduced nitrogen addition to maintain microbial diversity and contribute to the development of sustainable agriculture.

Climate capacity:the measurement for adaptation to climate change

This article proposed the concept of"climate capacity"as a way of measuring human's adaptiveness to climate change.This article also focused on the related concepts like ecological carrying capacity,water resources carrying capacity,land carrying capacity as well as population carrying capacity.The concept of climate capacity was articulated against a background of global climate and environmental change.Essentially,China's efforts to adapt to climate change was a matter of improving climate capacity,which is the ecosystem as well as the frequency,the intensity and the scale of human's social activities that the climatic resources of a particular geographic area were supposed to support.The climate capacity has two components.One is the natural climate capacity,which includes temperature,sunlight,precipitation,extreme climatic events,etc.The other is the derived climate capacity,which includes water resources,land resources,ecological systems,climatic risks,etc.The climate capacity can be developed or be transferred between regions by taking engineering,technology or regime-based adaptive measures.However,these adaptive measures must be implemented under the principle of economic rationalism,ecological integrity,climate protection,and social justice.It is expected that by combining the climate capacity and its threshold value with the assessment of climate change risks,we are able to predict the optimal population carrying capacity and the scale of socioeconomic development,and furthermore,provide policy support for the socioeconomic development strategy and adaptive planning.In the regions with high climate capacity,there is a symbiotic relationship between adaptation and socioeconomic development.But,in the regions with limited climate capacity,irrational development may further damage the environment.Taking the Yangtze River delta,a region with high climate capacity,and a region of Ningxia,a region with limited climate capacity,as illustrative examples,the authors of this article analyzed the policy implications of climate capacity and further made suggestions on the problems of capacitylimited adaptation and development-driven adaptation.This article argued that the concept of climate capacity can not only be used as an analytical instrument of climate change economics,but also it can provide research support for planning regional adaptation and development with climate change impact and risk assessments.

中国母婴营养健康研究队列与进展

生命早期1000天(母亲怀孕到幼儿2周岁)是膳食营养影响一生健康的关键窗口期,成年期疾病的预防应从生命早期开始.出生队列研究是探讨多种暴露因素与不良妊娠结局及出生缺陷的关系、生命早期暴露对终身健康影响的优选方法.中国母婴营养健康研究队列(China maternal and infant nutrition health cohort study, MINC)是国家母婴乳品健康工程技术研究中心启动的多地区健康母婴营养研究出生队列,重点研究早期膳食营养、喂养方式、生活习惯等与婴儿肠道菌群和近期、远期健康的相关性,探索成人非感染性疾病的早期营养干预预防措施,指导婴幼儿科学喂养.本文介绍了MINC背景、结构、研究目的及队列已入组人群、生物样本收集、母乳成分、肠道菌群等研究进展.

过表达MtVP1对马铃薯表型及糖代谢的影响

I型H^(+)-PPase参与糖异生和蔗糖分解代谢,利用不同的糖(蔗糖、葡萄糖和果糖)饲喂拟南芥(Arabidopsis thaliana)Ⅰ型H^(+)-PPase基因不同类型的突变体,产生的表型不一致,因此,推测Ⅰ型H^(+)-PPase可能存在其它影响糖代谢的机制。为进一步明确该酶对糖代谢的影响,以过表达MtVP1的马铃薯(Solanum tuberosum)渭薯4号为研究对象,观察不同培养条件下的表型,监测糖含量变化,并利用转录组测序分析转录谱。结果表明,过表达MtVP1马铃薯表现出红色茎、紫色花和表皮毛更发达,单株块茎数减少,块茎变大,块茎皱缩速度加快;转基因马铃薯块茎中淀粉、葡萄糖和果糖含量显著下降,芽中葡萄糖和果糖含量也显著下降。果糖饲喂导致转基因马铃薯花青素含量显著降低;转基因马铃薯体内果糖-1,6-二磷酸酶和果糖-2,6-二磷酸酶基因表达上调3–7倍。研究结果为进一步从糖代谢角度探究Ⅰ型H^(+)-PPase的生理功能提供参考。

Dual-network hydrogel based on ionic nano-reservoir for gastric perforation sealing

In recent years,remarkable progress has been made in the research of injectable hydrogel for internal tissue healing.However,the therapeutic outcome is usually limited when the hydrogel is used for the treatment of gastric perforation due to the high acidic gastric juice and violent deformation of the gastric wall.Regarding these challenges,we proposed an ionic nano-reservoir(INR)-based dual-network hydrogel,which has excellent adhesion and mechanical properties,and can be easily applied to the perforation site to block the perforation while promoting tissue repairing.The results showed that the first network made of polyacrylamide had cross-linked on the stomach tissue within 5 s under blue light,and enhanced the adhesion performance through mechanical interlock.The nano-hydroxyapatite acted as ionic INR,which can gradually release Ca^(2+) under acid environments to form the second network with sodium alginate and inhibit the swelling of hydrogel in gastric juice.Meanwhile,the adhesion was further enhanced through amide covalent bonds at the hydrogel-tissue interface with the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide(EDC/NHS).The dual network hydrogels obtained by the INR strategy could be employed as a potential therapeutic option for gastric perforation and other similar biomedical prolems.

Conjugated polymer nanoparticles as fluorescence switch for selective cell imaging

Fluorescence switch plays a vital role in bioelectronics and bioimaging.Herein,we presented a new kind of facile electrostatic complex nanoparticles(ECNs)for fluorescence switching in cells and marking of individual cell.The ECNs were prepared by mixing positively charged poly(6-(2-(thiophen-3-yl)ethoxy)hexyl trimethylammonium bromide)(PT)and negatively charged diarylethene sodium salt(DAECOONa).DAE-COONa is a photoswitchable molecule which can be transformed between the ring-closed fo rm and ring-open form under the irradiation of UV or visible light.The closed-form of DAE-COONa can efficie ntly quench the fluorescence of PT through intermolecular energy transfer,while the open form of DAE-COONa does not influence the emission of PT.Thus,the fluorescence of ECNs can be modulated by light irradiation,and the ECNs with good fluorescence switching performance have been employed for fluorescence imaging and individual cell lighting up process successfully.We demonstrate that the electrostatic complex strategy provides a facile method to construct fluorescence switch fo r selective cell marking and imaging applications.

Enzyme activity and phosphate uptake in the small intestine of Sprague Dawley rats improved by supplementation of infant formula with prebiotics

This study was to identify the effects of prebiotics supplemented in infant formula on enzyme activity and phosphate uptake in the small intestine of Sprague Dawley(SD) rats. Forty-eight healthy SD rats at15 days old(a week before weaning) with similar weight were randomly divided into 3 groups: A(control group), B, C, with 16 rats per group. Rats in groups A, B, C were fed a standard infant formula, the standard infant formula supplemented with oligosaccharides, and the standard infant formula supplemented with polysaccharides, respectively. The feeding test was conducted for 28 d. Compared with group A, the results showed the following: 1) the activities of sucrose and lactase in the small intestine were significantly increased in SD rats of group C(P < 0.05); 2) the relative expressions of lactase gene in the anterior and posterior segments of the small intestine were significantly increased by 1.68 and 2.26 in SD rats of group C(P < 0.05), and the relative expression of Mgam gene in the posterior segment of the small intestine was significantly increased by 0.99 in SD rats of group C(P < 0.05); 3) the relative expressions of Na/Pi-IIb gene in the anterior and posterior segments of the small intestine were significantly increased by 1.85 and 2.28 in SD rats of group C(P < 0.05). These results indicate that the supplementation of infant formula with prebiotics can promote enzyme activity in the small intestine by increasing the relative expression of enzyme gene or by decreasing intestinal injury, and can increase the relative expression of Na/Pi-IIb gene. The effect of polysaccharides is better than that of oligosaccharides.

Metabonomic study of the biochemical profiles of heterozygous myostatin knockout swine

Myostatin is a transforming growth factor-beta family member that normally acts to limit skeletal muscle growth. Myostatin gene (MSTN) knockout (KO) mice show possible effects for the prevention or treatment of metabolic disorders such as obesity and type 2 diabetes. We applied chromatography and mass spectrometry based metabonomics to assess system-wide metabolic response of heterozygous MSTN KO (MSTN+/-) swine. Most of the metabolic data for MSTN+/- swine were similar to the data for wild type (WT) control swine. There were, however, metabolic changes related to fatty acid metabolism, glucose utilization, lipid metabolism, as well as BCAA catabolism caused by monoallelic MSTN depletion. The statistical analyses suggested that: (1) most metabolic changes were not significant in MSTN+/- swine compared to WT swine; (2) only a few metabolic properties were significantly different between KO and WT swine, especially for lipid metabolism. Significantly, these minor changes were most evident in female KO swine and suggested differences in gender sensitivity to myostatin.