用于治疗诊断学的手性无机纳米材料

无机手性纳米材料因其优越的手性光学活性和物理性能而被广泛关注,其中贵金属和半导体等手性材料的制备取得了重大进展。本文介绍了几种具有良好生物相容性和低细胞毒性的手性纳米材料,并重点介绍了它们的合成方法以及手性光学特性。此外,我们总结了手性纳米材料在一些常见疾病的诊断和治疗中的应用,如阿尔茨海默症(AD)、帕金森症(PD)、糖尿病甚至癌症等,无机手性的引入将为诊断和治疗这些疾病提供一种新的策略。

轻掺杂硅基神经电极的光噪声消减

硅基神经电极是记录神经细胞放电活动的一种实用工具。使用标准的集成电路加工技术,在宽度仅为70μm的单个硅基针上能排布上千个电极记录位点。光遗传学的发展使控制神经元活动更加精确,通过在给予光刺激的同时记录神经元的电活动,可以获取更丰富的脑活动信息。当使用黄光或蓝光刺激神经元时,光子的能量大于硅衬底的禁带宽度,价带电子被激发到导带,从而生成电子-空穴对。因此,在光刺激下使用硅基神经电极时,硅基板中的光生载流子将严重干扰电极的信噪比。为满足在光刺激同时记录电活动的应用需求,必须减少光对硅基神经电极的噪声干扰。传统的降噪方法是使用重掺杂硅作为衬底材料,通过增加杂质浓度来降低载流子寿命,从而降低硅电极的光学噪声。但是,重掺杂的硅衬底比轻掺杂的硅衬底具有更多的晶格缺陷,这使得硅基电极更加脆弱,并且该方法与标准的集成电路加工技术不兼容。通过分析在轻掺杂硅衬底上制造电极的光致噪声机理,我们发现由光激发产生的载流子的不均匀分布将使轻掺杂硅衬底极化。由光致极化引起的电势将影响在其上制造的电极。将轻掺杂硅衬底金属化和接地将有效降低极化电位。使用这种方法,由光诱发的噪声幅度将下降到原始值的0.87%。为了确保神经元的放电率,将光刺激脉冲频率选择为20 Hz。在1 mW·mm^(-2)的光照下,电极的背景噪声可控制在45μV以下,可以满足一般光遗传学应用的需求。经过上述方式改造后的轻掺杂硅衬底将满足光遗传学应用对神经探针的要求。与传统的通过重掺杂整个衬底降低光噪声方法不同,该方法与标准的集成电路加工技术兼容,为利用标准集成电路加工技术制备高密度、高通量硅电极提供了噪声消除方法。

State of China’s climate in 2021

2021年,中国气候暖湿特征明显,全国平均气温10.5℃,较常年偏高1.0℃,创下了1951年以来最高纪录;全国平均降水量672.1毫米,比常年偏多6.7%,其中北方地区平均降水量较常年偏多40.2%,为1961年以来第二多.汛期暴雨过程强度大,极端性显著,河南特大暴雨灾害影响重,黄河中下游流域秋汛明显;高温过程多,夏秋南方高温持续时间长;区域性,阶段性气象干旱明显,华南干旱影响较重;台风生成和登陆均偏少,“烟花”陆地滞留时间长,影响范围广;强对流天气强发,极端大风频发,局地致灾重;寒潮过程多,强度大,极端低温频现;沙尘天气出现早,强沙尘暴过程多.

积极主义刑法观下公共卫生事件中的刑法适用——围绕司法解释性文件的展开

针对新型冠状病毒性肺炎疫情的防控,作为司法解释性文件的2020年《关于依法惩治妨害新型冠状病毒感染肺炎疫情防控违法犯罪的意见》介入社会治理的维度更多,范围更广,呈现出应对社会新问题的活跃姿态。对于其内容是否有违刑法谦抑主义,应当在具体的刑法观下进行判断。从当前的发展趋势看,我国应当采取积极主义刑法观,实现适度而有效的犯罪化。同时,应始终将保护法益作为刑法的价值追求,避免陷入"新刑法工具主义"。鉴于此,突发公共卫生事件中对司法解释性文件的适用,应在强调保护公共安全、维护社会秩序的同时,遵守罪刑法定主义,避免对条文的不当扩张解释,并重视考量违法阻却事由及个案责任要素,以保障公民的个人权益。

State of China’s Climate in 2020

2020年,全国平均气温10.25°C,较常年偏高0.7°C;全国平均降水量694.8毫米,比常年偏多10.3%.总体上涝重于旱,夏季南方地区发生1998年以来最严重汛情,暴雨洪涝灾害重;干旱呈区域性阶段性特征,灾害损失偏轻;春夏季节转换早,高温出现早,极端性强,夏季南方高温持续时间长;登陆台风偏少,影响时段和地域集中;冷空气影响范围广,局地降温幅度大.与近十年平均值相比,气象灾害造成的农作物受灾面积和死亡失踪人口明显偏少,直接经济损失略偏多.

Current status of gene therapy for motor neuron disease

OBJECTIVE： Although the etiology and pathogenesis of motor neuron disease is still unknown, there are many hypotheses on motor neuron mitochondrion, cytoskeleton structure and functional injuries. Thus, gene therapy of motor neuron disease has become a hot topic to apply in viral vectors, gene delivery and basic gene techniques. DATA SOURCES： The related articles published between January 2000 and October 2006 were searched in Medline database and ISI database by computer using the keywords ＂motor neuron disease, gene therapy＂, and the language is limited to English, Meanwhile, the related references of review were also searched by handiwork.STUDY SELECTION ： Original articles and referred articles in review were chosen after first hearing, then the full text which had new ideas were found, and when refer to the similar study in the recent years were considered first. DATA EXTRACTION ： Among the 92 related articles, 40 ones were accepted, and 52 were excluded because of repetitive study or reviews. DATA SYNTHESIS ： The viral vectors of gene therapy for motor neuron disease include adenoviral, adeno-associated viral vectors, herpes simplex virus type 1 vectors and lentiviral vectors. The delivery of them can be achieved by direct injection into the brain, or by remote delivery after injection vectors into muscle or peripheral nerves, or by ex vivo gene transfer. The viral vectors of gene therapy for motor neuron disease have been successfully developed, but the gene delivery of them is hampered by some difficulties. The RNA interference and neuroprotection are the main technologies for gene-based therapy in motor neuron disease. CONCLUSION ： The RNA interference for motor neuron disease has succeeded in animal models, and the neuroprotection also does. But, there are still a lot of questions for gene therapy in the clinical treatment of motor neuron disease.

Study on Pharmacological Effects of Peikun Pills

[Objectives]To explore the effects of Peikun Pill on blood pressure of healthy adult male rats.[Methods]The duodenum of anesthetized rats was given different doses of Peikun Pills,normal saline was used as a blank control group,and captopril was used as a positive western medicine control group.The systolic blood pressure,diastolic blood pressure,mean blood pressure and pulse pressure difference(systolic blood pressure-diastolic blood pressure),and heart rate were measured,myocardial tension time index was calculated,and statistical processing was performed.[Results]Peikun Pills have a significant pressure boosting effect,but have no effect on the myocardial tension time index.Captopril has the effects of lowering blood pressure,slowing down the heart rate and reducing the myocardial tension time index,and significantly increasing the pulse pressure difference.[Conclusions]Peikun Pills can increase blood pressure of rats.Peikun Pills are suitable for women with hypotension accompanied by anemia.However,patients with hypertension are prohibited to use.

Correlation of icing events with meteorological variables,and two statistical models to discriminate freezing days

In this paper, the characteristics of meteorological variables are statistically correlated with icing events （i.e., glaze and rime） in China, using daily observations of air temperature, relative humidity, wind speed, and weather phenomena from 700 stations in China from 1954 to 2008. The weather conditions most favorable for icing events are investigated and two statistical models are developed to discriminate potential freezing days. Low air temperature, high relative humidity, and low wind speed are shown to be important conditions for occurrence of icing events; also, the favorable daily mean air temperature is shown to have a decreasing trend from north to south in China, while the favorable relative humidity and wind speed varies little across the country. The statistical model developed with the daily mean temperature combined with precipitation, fog, and mist weather phenomena proved to be well able to determine the possible occurrence of freezing days. The accuracy of model outputs is well above 60% for northwestem Yun- nan, Guizhou, northern Guangxi, southern Hunan, and southern Jiangxi, among other regions where icing events are more fre- quent, and the average false alarms are few. Using observations or forecast products of conventional meteorological variables, this model has high performance and is practical and applicable for early warning and monitoring of icing events.

Lung adeno-squamous carcinoma modeling using oncogenic KRAS activation in human embryonic stem cell-derived alveolar organoids

Mutant KRAs is a common driver in lung cancer.Nevertheless,the occurrence of human lung cancer and its subsequent development after activation of oncogenic KRAS in epithelial cells remain poorly understood.Organoids are embedded in three-dimensional Matrigel in which tissue-derived human adult stem cells can efficiently grow for a long time,maintaining genetic and phenotypic stability."But until now,the use of organoids to simulate human non-small cell lung cancer has not been reported.

马铃薯Y病毒RPA-CRISPR/Cas12a检测技术体系的建立与应用

植物病毒病是制约农作物安全生产的重要因素,病毒检测能够发现病毒并确定病毒的种类,是病害监测预警和防控的关键。该研究以马铃薯Y病毒(PVY)为检测对象,建立了基于RPA-CRISPR/Cas12a的检测体系。结果表明,(1)CRISPR/Cas12a检测体系内Cas12a及各组分为检测顺利进行所必要;(2)crRNA的靶点位置对Cas12a蛋白活性有较大影响,当crRNA的靶点包含部分PAM位点序列时,反应效率最高;(3)RPA-CRISPR/Cas12a检测模板的最低限度为3×10^(2)copies·μL^(-1),灵敏度高于PCR及qPCR检测法;(4)RPA-CRISPR/Cas12a检测体系与核酸粗提及逆转录反应联合,可在非实验室环境下进行PVY检测,整个过程耗时约60分钟。该研究建立了基于RPA-CRISPR/Cas12a的PVY检测技术体系,为在非实验室条件下实时快速检测植物病毒提供了一种有效方法。

Suppression of Jasmonic Acid-Mediated Defense by Viral-Inducible MicroRNA319 Facilitates Virus Infection in Rice

MicroRNAs （miRNAs） are pivotal modulators of plant development and host-virus interactions. However, the roles and action modes of specific miRNAs involved in viral infection and host susceptibility remain largely unclear. In this study, we show that Rice ragged stunt virus （RRSV） infection caused increased accumulation of miR319 but decreased expression of miR319-regulated TCP （TEOSINTE BRANCHED/ CYCLOIDEA/PCF） genes, especially TCP21, in rice plants. Transgenic rice plants overexpressing miP,319 or downregulating TCP21 exhibited disease-like phenotypes and showed significantly higher susceptibility to RRSV in comparison with the wild-type plants. In contrast, only mild disease symptoms were observed in RRSV-infected lines overexpressing TCP21 and especially in the transgenic plants overexpressing miR319- resistant TCP21. Both RRSV infection and overexpression of miR319 caused the decreased endogenous jasmonic acid （JA） levels along with downregulated expression of JA biosynthesis and signaling-related genes in rice. However, treatment of rice plants with methyl jasmonate alleviated disease symptoms caused by RRSV and reduced virus accumulation. Taken together, our results suggest that the induction of miR319 by RRSV infection in rice suppresses JA-mediated defense to facilitate virus infection and symp- tom development.

红色长余辉材料的研究进展

长余辉材料具有诱人的应用前景.然而在三基色长余辉材料中,相对于蓝色和绿色,红色长余辉材料的发光强度和余辉时间还远远不能满足实际应用的需要.因此,探索和研究新型的红色长余辉材料具有重要的理论和实际意义.本综述总结了红色长余辉材料的余辉机理、合成方法、发光中心类型和应用,讨论了红色长余辉材料研究和应用中存在的问题,并对红色长余辉材料发展前景进行了展望.

Context-Aware Social Media User Sentiment Analysis

The user-generated social media messages usually contain considerable multimodal content.Such messages are usually short and lack explicit sentiment words.However,we can understand the sentiment associated with such messages by analyzing the context,which is essential to improve the sentiment analysis performance.Unfortunately,majority of the existing studies consider the impact of contextual information based on a single data model.In this study,we propose a novel model for performing context-aware user sentiment analysis.This model involves the semantic correlation of different modalities and the effects of tweet context information.Based on our experimental results obtained using the Twitter dataset,our approach is observed to outperform the other existing methods in analysing user sentiment.

An antifouling catechol/chitosan-modified polyvinylidene fluoride membrane for sustainable oil-in-water emulsions separation

Low-pressure membrane filtrations are considered as effective technologies for sustainable oil/water separation.However,conventional membranes usually suffer from severe pore clogging and surface fouling,and thus,novel membranes with superior wettability and antifouling features are urgently required.Herein,we report a facile green approach for the development of an underwater superoleophobic microfiltration membrane via one-step oxidant-induced ultrafast co-deposition of naturally available catechol/chitosan on a porous polyvinylidene fluoride(PVDF)substrate.Membrane morphology and surface chemistry were studied using a series of characterization techniques.The as-prepared membrane retained the original pore structure due to the ultrathin and uniform catechol/chitosan coating.It exhibited ultrahigh pure water permeability and robust chemical stability under harsh pH conditions.Moreover,the catechol/chitosan hydrophilic coating on the membrane surface acting as an energetic barrier for oil droplets could minimize oil adhesion on the surface,which endowed the membrane with remarkable antifouling property and reusability in a cyclic oil-in-water(O/W)emulsion separation.The modified membrane exhibited a competitive flux of~428 L/(m^(2)·h·bar)after three filtration cycles,which was 70%higher than that of the pristine PVDF membrane.These results suggest that the novel underwatersuperoleophobic membrane can potentially be used for sustainable O/W emulsions separation,and the proposed green facile modification approach can also be applied to other water-remediation materials considering its low cost and simplicity.

Production of very-high-amylose cassava by post-transcriptional silencing of branching enzyme genes

High amylose starch can be produced by plants deficient in the function of branching enzymes(BEs).Here we report the production of transgenic cassava(Manihot esculenta Crantz)with starches containing up to 50%amylose due to the constitutive expression of hair-pin ds RNAs targeting the BE1 or BE2 genes.All BE1-RNAi plant lines(BE1i)and BE2-RNAi plant lines(BE2i)were grown up in the field,but with reduced total biomass production.Considerably high amylose content in the storage roots of BE2i plant lines was achieved.Storage starch granules of BE1i and BE2i plants had similar morphology as wild type(WT),however,the size of BE1i starch granules were bigger than that of WT.Comparisons of amylograms and thermograms of all three sources of storage starches revealed dramatic changes to the pasting properties and a higher melting temperature for BE2i starches.Glucan chain length distribution analysis showed a slight increase in chains of DP>36 in BE1i lines and a dramatic increase in glucan chains between DP 10-20 and DP>40 in BE2i lines.Furthermore,BE2i starches displayed a B-type X-ray diffraction pattern instead of the A-type pattern found in BE1i and WT starches.Therefore,cassava BE1 and BE2 function differently in storage root starch biosynthesis.

CgVeA, a light signaling responsive regulator, is involved in regulation of chaetoglobosin A biosynthesis and conidia development in Chaetomium globosum

Cytochalasans,with diverse structures and pharmacological activities,are a class of compounds containing isoindolinone moieties fused to the tricyclic or tetracyclic ring system.Chaetoglobosin A(cheA),mainly produced by Chaetomium globosum,is the most abundant cytochalasan.However,limited understanding of transcriptional regulation of morphological development and cheA biosynthesis in C.globosum has hindered cheA application in agriculture and biomedical field.This study examined the regulatory role of CgVeA gene in C.globosum.CgVeA had significant effect on secondary metabolites production in C.globosum,similar to that reported in other filamentous fungi.Inactivation of CgVeA caused an obvious decrease in cheA production from 51.32 to 19.76 mg/L under dark conditions.In contrast,CgVeA overexpression resulted in a dramatic increase in cheA production,reaching 206.59 mg/L under light conditions,which was higher than that noted under dark condition.The RT-qPCR results confirmed that CgVeA,as a light responsive regulator,positively regulated cheA biosynthesis by controlling the expression of core genes of the cheA biosynthetic gene cluster and other relevant regulators.Electrophoretic mobility shift assays proved that CgVeA directly regulated LaeA,cheR,and p450,and indirectly regulated PKS.Moreover,CgVeA had a significant effect on the regulation of asexual spores production.When compared with wild-type C.globosum,CgVeA-silenced and CgVeA overexpression mutants presented remarkable differences in sporulation,irrespective of light or dark condition.Besides,CgVeA expression was speculated to negatively regulate spore formation.These findings illustrated the regulatory mechanism of a hypothetical global regulator,CgVeA,in C.globosum,suggesting its potential application in industrial-scale cheA biosynthesis.

Passive Super-Low Frequency electromagnetic prospecting technique

The Super-Low Frequency （SLF） electromag- netic prospecting technique, adopted as a non-imaging remote sensing tool for depth sounding, is systematically proposed for subsurface geological survey. In this paper, we propose and theoretically illustrate natural source magnetic amplitudes as SLF responses for the first step. In order to directly calculate multi-dimensional theoretical SLF responses, modeling algorithms were developed and evaluated using the finite difference method. The theore- tical results of three-dimensional （3-D） models show that the average normalized SLF magnetic amplitude responses were numerically stable and appropriate for practical interpretation. To explore the depth resolution, three-layer models were configured. The modeling results prove that the SLF technique is more sensitive to conductive objective layers than high resistive ones, with the SLF responses of conductive objective layers obviously show- ing uprising amplitudes in the low frequency range. Afterwards, we proposed an improved Frequency-Depth transformation based on Bostick inversion to realize the depth sounding by empirically adjusting two parameters. The SLF technique has already been successfully applied in geothermal exploration and coalbed methane （CBM） reservoir interpretation, which demonstrates that the proposed methodology is effective in revealing low resistive distributions. Furthermore, it siginificantly contributes to reservoir identification with electromagnetic radiation anomaly extraction. Meanwhile, the SLF inter- pretation results are in accordance with dynamic production status of CBM reservoirs, which means it could provide an economical, convenient and promising method for exploring and monitoring subsurface geo-objects.

A non-structural protein encoded by Rice Dwarf Virus targets to the nucleus and chloroplast and inhibits local RNA silencing

RNA silencing is a potent antiviral mechanism in plants and animals. As a counter-defense, many viruses studied to date encode one or more viral suppressors of RNA silencing(VSR). In the latter case, how different VSRs encoded by a virus function in silencing remains to be fully understood. We previously showed that the nonstructural protein Pns10 of a Phytoreovirus, Rice dwarf virus(RDV), functions as a VSR. Here we present evidence that another nonstructural protein, Pns11, also functions as a VSR. While Pns10 was localized in the cytoplasm, Pns11 was localized both in the nucleus and chloroplasts. Pns11 has two bipartite nuclear localization signals(NLSs), which were required for nuclear as well as chloroplastic localization. The NLSs were also required for the silencing activities of Pns11. This is the first report that multiple VSRs encoded by a virus are localized in different subcellular compartments, and that a viral protein can be targeted to both the nucleus and chloroplast. These findings may have broad significance in studying the subcellular targeting of VSRs and other viral proteins in viral-host interactions.

Semiconductor loss calculation of DC-DC modular multilevel converter for HVDC interconnections

DC-DC modular multilevel converter(DC-DC MMC)is an attractive candidate for high-voltage DC(HVDC)interconnections since it can provide the required voltage matching,galvanic isolation and flexible power control abilities.The semiconductor loss of such a DC-DC MMC is a major concern for both system evaluation and parameter design.However,it cannot be measured directly since it is out of the precision range of the high-voltage measuring equipment,and thus,mathematical analysis is considered as a feasible alternative.This paper proposes an accurate off-line loss calculation method for DC-DC MMC modulated by fundamental frequency modulation.Based on the characteristics of the modulation,the switching moments along with the instantaneous voltage and current can be calculated exactly,and the conduction loss and switching loss of each submodule can be expressed in a mathematical way.The calculation results are compared with the simulation results from a comprehensive switched model and show good accuracy performance within a relative error of±2%under different operating conditions.

Study of the System of the Witness Appearing in Court:From the Perspective of Criminal Proceedings

It is of great significance for witnesses to appear in court in criminal cases so as to safeguard the right of confrontation of the defendant and achieve judicial justice.However,the witnesses in criminal cases refuse to appear in court and only give written testimony,and this has become a long‑standing problem in the judicial practice of China.To solve this problem,the Criminal Procedure Law of China,amended and improved the system of the witness appearing in court in 2012.Nevertheless,if the underlying problems in the judicial system of China are not settled,the system of the witness appearing in court in criminal cases still cannot turn into practicable measures.