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。

Effects of dietary valine supplementation during late gestation on the reproductive performance and mammary gland development of gilts

Background:Mammary gland development during late gestation in gilts is a major factor that alters the composition of colostrum and growth performance of piglets.Plasma valine is taken up and metabolized extensively by the mammary gland;however,the effects of valine on mammary gland development during late gestation are still unclear.Thirty primiparous gilts were divided into three treatment groups(n=10)and received one of the three diets starting on day 75 of gestation until the day of farrowing.The total dietary valine to lysine ratio of the three diets was 0.63(LV),0.73(MV),and 0.93(HV),respectively.Results:Dietary valine supplementation during late gestation did not affect(P>0.05)the litter size and weight at farrowing;however,the piglet weight and average daily gain at weaning were linearly increased(P<0.05)as the dietary valine increased.The highest piglet weight at weaning was observed when the gilts were provided the HV diet.Dietary valine supplementation linearly elevated(P<0.05)protein,fat and solids-not-fat and some free amino acids content in colostrum.The concentration of prolactin in plasma of gilts was linearly increased in response to valine supplementation at days 1 and 10 of lactation(P<0.05).Furthermore,with increasing dietary valine allowance,a linear increase(P<0.05)was observed in the area of the lumen of alveolus and the content of DNA,RNA,and total protein in the mammary tissues at day 1 of lactation.Moreover,the protein expression of cyclin D1,p-mTOR,p-S6,and p-4EBP1 was also linearly increased(P<0.05)in the mammary tissue at day 1 of lactation.However,no difference(P>0.05)was observed in the indices related to mammary development and the mTOR signaling pathway at day 21 of lactation.Conclusion:The results revealed that increasing the total dietary valine to lysine ratio to 0.93 during late gestation significantly enhances the piglet weight and average daily gain at weaning probably due to improved development of mammary gland.

Design of Thomson scattering diagnostic system on linear magnetized plasma device

In addition to the magnetic confinement fusion plasma,Thomson scattering has been applied to measure electron density and temperature of low-temperature plasmas.Based on a linear magnetized plasma device,a set of Thomson scattering diagnostic system is designed to diagnose the plasma with n_(e)=10^(18)–10^(19)m^(-3)and T_(e)=2–5eV.Due to low plasma temperature and density,this diagnostic system needs high spectral resolution and collection efficiency to meet the requirements of electron velocity distribution function measurements.Through the bench test,it is confirmed that the spectral resolution reaches 0.01 nm,and theoretical collection efficiency is high enough to obtain a Thomson scattering spectrum by 1000 accumulations.

The Marketization of Land-related Indicators Based on the Practice in Anhui Province

Under the background of the new urbanization,this paper performs an empirical analysis of requisition-compensation balance indicators in Chuzhou City,and points out the problems in the land transaction.At the national level,it is necessary to introduce the measures to regulate the market transactions of requisition-compensation balance indicators as soon as possible,put safeguarding the interests of the majority of farmers in the first place during market transactions,and establish the a unified market platform for the transaction of land-related indicators,so as to boost the urban construction,promote the integration of urban and rural areas,and speed up the new urbanization process.

Dynamic modulated single-photon routing

The dynamic control of single-photon scattering in a pair of one-dimensional waveguides mediated by a time-modulated atom-cavity system is investigated.Two cases,where the waveguides are coupled symmetrically or asymmetrically to the atom-cavity system,are discussed in detail.The results show that such time-modulated atom-cavity configuration can behave as a dynamical tunable directional single-photon router.The photons with different frequencies can dynamically be routed from the incident waveguide into any ports of the other with a 100%probability via adjusting the modulated amplitude or phases of the time-modulated atom-cavity coupling strengths,associate with the help of the asymmetrical waveguide-cavity couplings.Furthermore,the influence of dissipation on the routing capability is investigated.It is shown that the present single-photon router is robust against the dissipative process of the system,especially the atomic dissipation.These results are expected to be applicable in quantum information processing and design quantum devices with dynamical modulation.

Nonreciprocal single-photon scattering mediated by a drivenΛ-type three-level giant atom

A waveguide-QED with giant atoms,which is capable of accessing various limits of a small one,provides a new paradigm to study photon scatterings.Thus,how to achieve nonreciprocal photon transmissions via such a giant atom setup is highly desirable.In this study,the nonreciprocal single-photon scattering characteristics of a double-drivenΛ-type three-level giant atom,where one of the transition couples to a 1D waveguide at two separate points,and the other is driven by two coherent driving fields,are investigated.It is found that a frequency-tunable single-photon diode with an ideal contrast ratio can be achieved by properly manipulating the local coupling phases between the giant atom and the waveguide,the accumulation phase between the two waveguide coupling points,the Rabi frequencies and phase difference of the two driven fields.Compared to the previous single driving schemes,on the one hand,the presence of the second driving field can provide more tunable parameters to manipulate the nonreciprocal single-photon scattering behavior.On the other hand,here perfect nonreciprocal transmission for photons with arbitrary frequencies is achievable by tuning the driving phases while the two driving fields keep on turning,which provides an alternative way to control the nonreciprocal single-photon scattering.Furthermore,the results reveal that both the location and width of each optimal nonreciprocal transmission window is also sensitive to the driving detuning,and a single-photon diode with wide or narrow bandwidth can be realized based on demand.These results may be beneficial for designing nonreciprocal single-photon devices based on a double-driven giant atom setup.

Ryanodine受体的功能结构和调节因子

Ryanodine受体(ryanodine receptor,Ry R)是位于细胞内内质网/肌浆网膜上的钙离子释放通道蛋白。Ry R是由四个足状结构的亚单位组成的同源四聚体,每个亚单位大于550 k Da,四聚体的总分子量超过2 MDa,是迄今发现的内质网/肌浆网膜上最大的离子通道。哺乳动物有三种类型的Ry R,其中Ry R1主要分布在骨骼肌中,Ry R2首先发现于心肌,Ry R3主要在脑中有较多分布。Ry R钙离子释放通道在肌肉收缩、突触传递、激素分泌、蛋白折叠和程控性凋亡以及坏死等一系列以细胞功能为基础的生理过程中起着极其重要的作用,因而近些年在医学生物学和药学应用上都有极大的进展。该文就Ry R在机体中的分布、功能结构和调节因子等进行了介绍,其蛋白调节因子二氢吡啶受体(dihydropyridine receptor,DHPR)、钙调蛋白(Calmodulin)、隐钙素(calsequestrin)、FKBP(FK506-binding protein)家族蛋白和小分子调节因子咖啡因、离子等都是Ry R复合体行使细胞生理功能必不可少的因素。

干细胞再生生物学研究及临床应用的道德伦理问题探讨

干细胞具有分化为人类个体中250余种细胞的特性,该特性使再生生物学成为当今生命科学研究中最受瞩目的领域。美国和欧洲国家对干细胞研究的监管十分严格,其中一个重要原因是干细胞研究应用的道德伦理尚没有明确的界定。本文就以下几个问题进行讨论:干细胞科学研究中的伦理道德问题,干细胞再生生物学应用前景引发的科研道德问题;克隆人类胚胎以解决器官移植的材料短缺,人类干细胞来源和"生命废料"是否具有生存权等干细胞临床应用的伦理学问题;制定的国际伦理准则或法则应该对未来干细胞成果引发的伦理问题有所预见。应尽快厘清干细胞研究、临床应用与伦理道德之间的关系,加快建立相应法律法规,保证干细胞再生生物学研究在世界范围内造福人类健康。

医学分子生物学CRISPR基因编辑与社会法规的进步与完善

利用CRISPR基因技术体系进行精密编辑,标志着人类攻克遗传疾病在理论上已进入新阶段,临床应用已有了实质性的突破,对促进人类健康和社会的和谐具有重大意义。本文对该技术在临床的应用、社会影响、西方国家对该技术社会伦理道德的界定和法律法规的发展,以及CRISPR精密编辑技术对科研与社会伦理道德范畴的精细化进行了探讨。CRISPR在生殖生物学领域的应用,将导致生物医学领域发生社会发展的重大变革。CRISPR精准基因编辑和干细胞技术的巨大科研前景和商业价值,可能会带来一系列的问题。CRISPR基因精密编辑在生物医学中的应用对社会、对各级医疗机构、医学院校和研究机构均有重要的影响,卫生主管部门应借鉴国际上相关做法,制定科学研究伦理道德的相关政策法规,使中国在医学分子生物学领域作出应有的贡献。

医学分子生物学CRISPR基因编辑与疾病医疗的社会变革

利用CRISPR(规律成簇间隔短回文重复序列)技术体系进行基因精密编辑,从基因分子医学层面对疾病进行高效治疗已成为现代医学研究的重要方向,并在临床应用上将有重要的突破。本文论述其近期临床医学研究对社会的相关影响,对CRISPR基因精密编辑的知识产权归属问题进行了分析。以哈佛大学“精准基因修饰干细胞计划”为题探讨了该技术体系在人类遗传性疾病治疗中的应用,在器官移植上的成功将对社会产生重要的影响。CRISPR技术上的正负向高通量筛选,成功地捕获到黑素瘤的药物维罗非尼耐受敏感的关键基因,为解决这一问题打下了重要的基础。CRISPR基因精密编辑的应用已成为生物医学发展的趋势,分析其对人类健康的影响,有助于掌控这一历史性变革技术,为人类社会发展做出重要贡献。

CLE14 functions as a "brake signal" to suppress age-dependent and stress-induced leaf senescence by promoting JUB1-mediated ROS scavenging in Arabidopsis

Leaf senescence is an important developmental process in the plant life cycle and has a significant impact on agriculture.When facing harsh environmental conditions,monocarpic plants often initiate early leaf senes-cence as an adaptive mechanism to ensure a complete life cycle.Upon initiation,the senescence process is fine-tuned through the coordination of both positive and negative regulators.Here,we report that the small secreted peptide CLAVATA3/ESR-RELATED 14(CLE14)functions in the suppression of leaf senescence by regulating ROS homeostasis in Arabidopsis.Expression of the CLE14-encoding gene in leaves was signifi-cantly induced by age,high salinity,abscisic acid(ABA),salicylic acid,and jasmonic acid.CLE14 knockout plants displayed accelerated progression of both natural and salinity-induced leaf senescence,whereas increased CLE14 expression or treatments with synthetic CLE14 peptides delayed senescence.CLE14 pep-tide treatments also delayed ABA-induced senescence in detached leaves.Further analysis showed that over-expression of CLE14 led to reduced.ROS levels in leaves,where higher expression of ROS scavenging genes was detected.Moreover,CLE14 signaling resulted in transcriptional activation of JUB1,a NAC family tran-scription factor previously identified as a negative regulator of senescence.Notably,the delay of leaf senes-cence,reduction in H202 level,and activation of ROS scavenging genes by CLE14 peptides were dependent on JUB1.Collectively,these results suggest that the small peptide CLE14 serves as a novel"brake signal"to regulate age-dependent and stress-induced leaf senescence through JUB1-mediated ROS scavenging.

Microcavity top-emission perovskite light-emitting diodes

Light-emitting diodes(LEDs)based on perovskites show great potential in lighting and display applications.However,although perovskite films with high photoluminescence quantum efficiencies are commonly achieved,the efficiencies of perovskite LEDs are largely limited by the low light out-coupling efficiency.Here,we show that high-efficiency perovskite LEDs with a high external quantum efficiency of 20.2% and an ultrahigh radiant exitance up to 114.9mWcm^(−2) can be achieved by employing the microcavity effect to enhance light extraction.The enhanced microcavity effect and light outcoupling efficiency are confirmed by the study of angle-dependent emission profiles.Our results show that both the optical and electrical properties of the device need to be optimized to achieve high-performance perovskite LEDs.

Dietary energy intake affects fetal survival and development during early and middle pregnancy in Large White and Meishan gilts

This experiment was designed to determine the effects of variations in dietary energy intake on reproductive performance and gene expression of luteal and endometrium tissues in Large White(LW)and Meishan(MS) gilts during early and middle pregnancy. After insemination, 32 LW gilts were assigned to high and low(HE_Land LE_L, 14.23 and 12.56 MJ DE/kg, respectively) diet treatment groups,while 32 MS gilts were allocated to HE_M and LE_M(12.56 and 10.88 MJ DE/kg) groups. Gilts were slaughtered on days 35, 55 and 90 of gestation. The fetal survival and luteal progesterone(P_4) concentration in the HE_Lgroup were higher on day 35 but lower on day 90 of gestation compared with the LE_L group(P < 0.05) for LW gilts. However, fetal survival and luteal P_4 concentration on day 35 of gestation were greater(P < 0.05) in the LE_M group than in the HE_M group for MS gilts, but no significant difference in mid-gestation was showed. The fetal weights of both breeds were higher for the high energy diets compared with the respective control group on day 90 of gestation(P < 0.05). In addition,the m RNA levels of P_4 synthesis-related proteins had correlated with luteal P_4 concentration in both breeds. Further, endometrial levels of uteroferrin(ACP5), retinol-binding protein 4(RBP_4) and secreted phosphoprotein 1(SPP1) m RNA were upregulated in the HE_Lgroup on day 35 of gestation but ACP5 and SPP1 were downregulated on day 55 of gestation compared with the LE_Lgroup(P < 0.05) for LW gilts. In MS gilts, diet only affected the expression of SPP1(P < 0.05). Our results revealed the differential sensitivity of LW and MS breeds to variations in dietary energy intake. For LW gilts, the HE_Lgroup improved fetal survival on day 35 but a sustained high energy diet decreased fetal survival on day 90 of gestation. The differences in dietary energy intake did not influence fetal survival on day 90 of gestation but the higher energy diet did increase fetal weight in the MS breed compared with the lower energy intake diet. These results may be due to differential luteal secretion activity and endometrium gene expression in these two breeds.

同性婚姻立法机理:同性情感发展的自然性和社会性分析

同性情感的发育起源和遗传机制,以及发展的自然性和社会性,是美国联邦政府公布法案对同性情感实施法律保护的重要证据,同性婚姻合法化成为人类婚姻认知理念的历史性进步。本文探讨同性情感的社会学和生物科学史的自然性,阐述生物学进展在该历史进程中起到的重要作用:第一,同性情感社会认同的发展过程是一个漫长的社会历史过程,探讨该历程的特性对认清历史的过程和现实的合理性具有重要意义;第二,在动物界同性趋向与环境密切相关,对人类同性情感行为学中性别趋向是否有类似机理存在,可能有一定借鉴价值;第三,2016年发现性别起源的古菌嵌入学说也为性别的产生提供了崭新的研究途径,为认识同性情感的起源和社会现实提供了更加令人信服的自然性证据;第四,染色体性别决定学说相关的Xq28同性恋基因可能是生物性别决定的重要因子,经典生物学与现代生物学的有机结合使我们对同性情感的生物学基础有了更进一步的认识。

干细胞再生生物学研究悖论及相关法律问题探讨

干细胞可分化为构成人体的250余种细胞,这一特性为彻底攻克人类疾病带来了极大的希望,然而,现阶段也存在大量亟待解决的问题。干细胞基础研究结果应用于临床试验还有许多问题没有解决,仍然需要包括动物实验等中间试验在内的数据积累。干细胞应用前期的临床试验面临的科研人员职业道德的挑战、科学实验立论不够严谨、急功近利的虚假研究报道等问题必须坚决杜绝,在此基础上才能加快干细胞再生生物学从基础及临床试验走向临床应用的步伐。中国干细胞临床应用相关的法律法规必须借鉴发达国家的经验,组建至少包括法律界资深学者、医学伦理学专家、再生生物学领域的一线科研工作者和政治政策的制定者在内的干细胞应用相关法律委员会,颁布符合国情的法律。

The formation of perovskite multiple quantum well structures for high performance light-emitting diodes

Recent works showed that high efficient perovskite light-emitting diodes can be achieved from solution-processed,self-organized multiple quantum wells(MQWs)with an energy cascade.We investigate how the mixing of QWs with different band gaps can affect the perovskite LED device performance.We find that the annealing process can significantly affect the constitution of the MQWs films,where the dominant phase can evolve from large band gap QWs to small band gap QWs.The optimal constitution for LED application lies in a transition point of small-n QWs dominant phase to large-n QWs dominant phase,when the MQW film presents highest photoluminescence while still remains uniform film morphology.

Carbon performance evaluation model from the perspective of circular economy~The case of Chinese thermal power enterprise

Carbon emission reduction is the only way to alleviate environmental problems,such as global warming.Effective evaluation of carbon performance can help enterprises to carry out energy saving and emission reduction activities to a certain extent and promote sustainable development.This paper constructs a carbon performance evaluation index system that includes the four dimensions of carbon resource(energy)input,cycle,output,and carbon management by incorporating the principles of circular economy and the theory of resource value circulation from the perspective of the flow trajectory of carbon-containing resources in the circulation of enterprises combined with the production characteristics of thermoelectric enterprises.Subsequently,combined with the case study,this paper discusses the scientific and practical nature of the system and provides another way of thinking for carbon performance evaluation of micro-enterprises in other industries.This paper expands the application boundary of matter-element model and supplements the literature of carbon performance,which has certain theoretical and practical significance.

Temperature‑Regulating Phase Change Fiber Scaffold Toward Mild Photothermal–Chemotherapy

Photothermal therapy(PTT)is a treatment that increases the temperature of tumors to 42–48℃,or even higher for tumor ablation.PTT has sparked a lot of attention due to its ability to induce apoptosis or increase sensitivity to chemotherapy.Excessive heat not only kills the tumor cells,but also damages the surrounding healthy tissue,reducing therapeutic accuracy and increasing the possible side effects.Herein,a phase change fiber(PCF)scaffold serving as a thermal trigger in mild photothermal–chemo tumor therapy is developed to regulate temperature and control drug release.These prepared PCFs,comprised of hollow carbon fibers(HCFs)loaded with lauric acid as a phase change material(PCM),can effectively store and release any excess heat generated by irradiating with a near-infrared(NIR)laser through the reversible solid–liquid transition process of the PCM.With this feature,the optimal PTT temperature of implanted PCF-based composite scaffolds was identified for tumor therapy with minimal normal tissue damage.In addition,controlled release of chemotherapeutic drugs and heat shock protein(HSP)inhibitors from the PCF-based composite scaffolds have been shown to improve the efficacy of mild PTT.The developed PCF-based scaffold sheds light on the development of a new generation of therapeutic scaffolds for thermal therapy.

Changes of gut microbiome and metabolome in the AOM/DSS mouse model of colorectal cancer with FLASH radiation

Objective:To investigate the differences in small intestinal toxicity and taxonomic composition,diversity,and functional pathways of gut microbiome and metabolome after different radiotherapies in mouse colorectal cancer(CRC)model.Methods:Azoxymethane/dextran sodium sulfate(AOM/DSS)-induced mouse CRC model was treated with single pulse FLASH-RT(dose rate 100 Gy/s)or CONV-RT(dose rate 2 Gy/min)at whole abdomen.At 12 d after radiotherapy,sections of small intestinal tract tissue were dissected for hematoxylin and eosin(HE)staining and the fresh feces were collected for 16S ribosomal RNA(rRNA)microbiome sequencing and liquid chromatography and mass spectrometry(LC-MS)metabolomics sequencing to assess changes in the gut microbiota and metabolites.Microbial high-throughput 16S rRNA data was analyzed with QIIME2 and LEfSe softwares.ProteoWizard,XCMS and Ropls softwares were used for LC-MS analysis.Results:HE staining showed that FLASH-RT maintained small intestinal integrity and reduced the radiotherapyinduced injury.Sequencing analysis of gut fecal microbiome showed that phylum Bacteroidetes and genera Prevotella and Lactobacillus of microbial community were increased after FLASH-RT.Metabolomics sequencing analysis revealed that the metabolites after FLASH-RT were enriched in amino acid metabolism,while cholesterol metabolism was top enriched after CONV-RT.Conclusions:FLASH-RT significantly mitigates the small intestine tissue damage compared with CONV-RT.FLASHRT and CONV-RT have different impact on gut microbiota and its metabolites.Our results provide a theoretical basis for the early evaluation,prediction and individualized treatment of the irradiation effect after novel FLASHRT on tumors through the evaluation of intestinal microbiota and metabolites.

Titanium-promoted Intramolecular Photoenolization/Diels-Alder Reaction to Construct Polycyclic Terpenoids: Formal Synthesis of Mycoleptodiscin A

Summary of main observation and conclusion A titanium-promoted intramolecular photoenolization/Diels-Alder (PEDA) reaction was developed to construct the core skeleton of aromatic polycyclic terpenoids bearing an all-carbon quaternary center on the benzylic position. Titanium(Ⅳ) isopropoxide [Ti(Oi-Pr)4] plays a key role during the photo cycloaddition, which may help to accelerate the in teraction between dienophile and the stereo-hi ndered diene species as well as control the diastereoselectivity. This photolysis provides a new solution for the stereospecific formation core structures of aromatic abietane diterpenoids and sesquiterpenoids, which have multiple functional groups for the further transformations. As a synthetic application, it was successfully used in the synthesis of indolosesquiterpenoid mycoleptodiscin A.