荧光RNA及其生物传感技术研究进展

荧光RNA技术是一种新兴的RNA标记技术,可用于活细胞RNA的原位实时标记与成像,对于人们理解RNA的功能和调控机制发挥着至关重要的作用。基于荧光RNA的生物传感技术可用于活细胞内小分子代谢物以及蛋白质等靶标的实时动态检测,为生命科学基础研究以及生物医学传感技术开发提供极具价值的工具。本文对遗传编码的荧光RNA的发展历程、荧光RNA技术在活细胞RNA成像,以及基于荧光RNA的生物传感技术在活细胞代谢物检测等方面的应用进行了介绍和总结,并对该领域的发展现状和未来发展方向展开讨论和展望,以期为该技术的进一步发展和在相关领域的应用提供参考。

The first factor affecting dryland winter wheat grain yield under various mulching measures: Spike number

Water is the key factor limiting dryland wheat grain yield.Mulching affects crop yield and yield components by affecting soil moisture.Further research is needed to determine the relationships between yield components and soil moisture with yield,and to identify the most important factor affecting grain yield under various mulching measures.A long-term 9-yearifeld experiment in the Loess Plateau of Northwest China was carried out with three treatments:no mulch (CK),plastic mulch (M_(P)) and straw mulch (M_(S)).Yield factors and soil moisture were measured,and the relationships between them were explored by correlation analysis,structural equation modeling and significance analysis.The results showed that compared with CK,the average grain yields of M_(P) and M_(S) increased by 13.0and 10.6%,respectively.The average annual grain yield of the M_(P) treatment was 134 kg ha^(–1) higher than the M_(S) treatment.There were no significant differences in yield components among the three treatments (P<0.05).Soil water storage of the M_(S) treatment was greater than the M_(P) treatment,although the differences were not statistically signifiant.Soil water storage during the summer fallow period (SWSSF) and soil water storage before sowing (SWSS) of M_(S) were significantly higher than in CK,which increased by 38.5 and 13.6%,respectively.The relationship between M_(P) and CK was not statistically significant for SWSSF,but the SWSS in M_(P) was significantly higher than in CK.In terms of soil water storage after harvest (SWSH) and water consumption in the growth period(ET),there were no signi?cant differences among the three treatments.Based on the three analysis methods,we found that spike number and ET were positively correlated with grain yield.However,the relative importance of spike number to yield was the greatest in the M_(P )and M_(S) treatments,while that of ET was the greatest in CK.Suifcient SWSSF could indirectly increase spike number and ET in the three treatments.Based on these results,mulch can improve yield and soil water storage.The most important factor affecting the grain yield of dryland wheat was spike number under mulching,and ET with CK.These findings may help us to understand the main factors influencing dryland wheat grain yield under mulching conditions compared to CK.

Plastic mulch increases dryland wheat yield and water-use productivity,while straw mulch increases soil water storage

Amplifying drought stress and high precipitation variability impair dryland wheat production.These problems can potentially be minimized by using plastic mulch(PM)or straw mulch(SM).Therefore,wheat grain yield,soil water storage,soil temperature and water-use productivity of PM and SM treatments were compared with no mulch(CK)treatment on dryland wheat over a period of eight seasons.Compared to the CK treatment,PM and SM treatments on average significantly increased grain yield by 12.6 and 10.5%,respectively.Compared to the CK treatment,SM treatment significantly decreased soil daily temperature by 0.57,0.60 and 0.48℃ for the whole seasons,growing periods and summer fallow periods,respectively.In contrast,compared to the CK treatment,PM treatment increased soil daily temperature by 0.44,0.51 and 0.27℃ for the whole seasons,growing periods and summer fallow periods,respectively.Lower soil temperature under SM allowed greater soil water storage than under PM.Soil water storage pre-seeding was 17%greater under the SM than under the PM treatment.Soil water storage post-harvest was similar for the PM and SM treatments,but evapotranspiration was 4.5%higher in the SM than in the PM treatment.Consequently,water-use productivity was 6.6%greater under PM than under the SM treatment.Therefore,PM treatment increased dryland wheat yield and water-use productivity,while straw mulch increased soil water storage.

SimET: An open-source tool for estimating crop evapotranspiration and soil water balance for plants with multiple growth cycles

Accurate estimation of crop evapotranspiration(ETc) and soil water balance, which is vital for optimizing water management strategy in crop production, can be performed by simulation. But existing software has many deficiencies, including complex operation, limited scalability, lack of batch processing, and a single ETc model. Here we present simET, an open-source software package written in the R programming language. Many concepts involved in crop ETc simulation are condensed into functions in the package. It includes three widely used crop ETc models built on these functions: the single-crop coefficient,double-crop coefficient, and Shuttleworth–Wallace models, along with tools for preparing model data and comparing estimates. SimET supports ETc simulation in crops with repeated growth cycles such as alfalfa, a perennial forage crop that is cut multiple times annually.

青天葵黄酮F通过促进自噬减轻脂多糖诱导的大鼠急性肺损伤

目的:探讨青天葵黄酮F(NF)对脂多糖(LPS)诱导的急性肺损伤(ALI)大鼠的保护作用及其可能的作用靶点。方法:气管内注射LPS诱导大鼠ALI后,分别用高、中、低剂量(10.0、5.0、2.5 mg/kg)NF和3 mg/kg地塞米松(DEX)进行干预。采用苏木精—伊红染色(H&E染色)观察肺组织病理损伤;采用酶联免疫吸附法(ELISA)检测外周血和肺组织炎症因子;采用实时定量PCR法(RT-qPCR)检测组织中自噬通路相关基因mRNA的表达;采用Western blot和免疫组织化学法检测组织中自噬通路相关蛋白的表达;采用分子对接预测和模拟药物小分子与蛋白大分子间的结合。结果:NF可明显减轻大鼠肺组织的病理损伤,降低血清和肺组织中肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)和白细胞介素1β(IL-1β)水平,显著提高自噬相关基因5(ATG5)和Beclin 1(ATG6)的表达以及微管相关蛋白1轻链3β(LC3B)II与LC3B I的比值(均P<0.05)。结论:NF可通过促进自噬减轻LPS诱导的ALI,NF可能成为治疗ALI的一种潜在药物。

Application of atomic layer deposition in fabricating high-efficiency electrocatalysts

Electrocatalysis is a promising approach to clean energy conversion due to its high efficiency and low environmental pollution. Noble metal materials have been studied to show high activity toward electrocatalyltic reactions, although such applications remain restricted by the high cost and poor durability of the noble metals. By precisely adjusting the catalyst composition, size, and structure, electrocatalysts with excellent performance can be obtained. Atomic layer deposition(ALD) is a technique used to produce ultrathin films and ultrafine nanoparticles at the atomic level. It possesses unique advantages for the controllable design and synthesis of electrocatalysts. Furthermore, the homogenous composition and structure of the electrocatalysts prepared by ALD favor the exploration of structure-reactivity relationships and catalytic mechanisms. In this review, the mechanism, characteristics, and advantages of ALD in fabricating nanostructures are introduced first. Subsequently, the problems associated with existing electrocatalysts and a series of recently developed ALD strategies to enhance the activity and durability of electrocatalysts are presented. For example, the deposition of ultrafine Pt nanoparticles to increase the utilization and activity of Pt, fabrication of core–shell, overcoat, nanotrap, and other novel structures to protect the noble-metal nanoparticles and enhance the catalyst stability. In addition, ALD developments in synthesizing non-noble metallic electrocatalysts are summarized and discussed. Finally, based on the current studies, an outlook for the ALD application in the design and synthesis of electrocatalysts is presented.

Acid-activated and WO_x-loaded montmorillonite catalysts and their catalytic behaviors in glycerol dehydration

The use of H2SO4‐,HCl‐,H3PO4‐,and CH3COOH‐activated montmorillonite(Mt)and WOx/H3PO4‐activated Mt as catalysts for the gas‐phase dehydration of glycerol was investigated.The WOx/H3PO4‐activated Mt catalysts were prepared by an impregnation method using H3PO4‐activated Mt(Mt‐P)as the support.The catalysts were characterized using powder X‐ray diffraction,Fourier‐transform infrared spectroscopy,N2adsorption‐desorption,diffuse reflectance ultraviolet‐visible spectroscopy,temperature‐programmed desorption of NH3,and thermogravimetric analysis.The acid activation of Mt and WOx loaded on Mt‐P affected the strength and number of acid sites arising from H+exchange,the leaching of octahedral Al3+cations from Mt octahedral sheets,and the types of WOx(2.7≤x≤3)species(i.e.,isolated WO4/WO6‐containing clusters,two‐dimensional[WO6]polytungstates,or three‐dimensional WO3crystals).The strong acid sites were weakened,and the weak and medium acid sites were strengthened when the W loading on Mt‐P was12wt%(12%W/Mt‐P).The12%W/Mt‐P catalyst showed the highest catalytic activity.It gave a glycerol conversion of89.6%and an acrolein selectivity of81.8%at320°C.Coke deposition on the surface of the catalyst led to deactivation.

Root imaging from ground penetrating radar data by CPSO-OMP compressed sensing

As the amount of data produced by ground penetrating radar （GPR） for roots is large, the transmission and the storage of data consumes great resources. To alleviate this problem, we propose here a root imaging algorithm using chaotic particle swarm optimal （CPSO） compressed sensing based on GPR data according to the sparsity of root space. Radar data are decomposed, observed, measured and represented in sparse manner, so roots image can be reconstructed with limited data. Firstly, radar signal measurement and sparse representation are implemented, and the solution space is established by wavelet basis and Gauss random matrix; secondly, the matching function is considered as the fitness function, and the best fitness value is found by a PSO algorithm; then, a chaotic search was used to obtain the global optimal operator; finally, the root image is reconstructed by the optimal operators. A-scan data, B-scan data, and complex data from American GSSI GPR is used, respectively, in the experimental test. For B-scan data, the computation time was reduced 60 % and PSNR was improved 5.539 dB; for actual root data imaging, the reconstruction PSNR was 26.300 dB, and total computation time was only 67.210 s. The CPSO-OMP algorithm overcomes the problem of local optimum trapping and comprehensively enhances the precision during reconstruction.

N‐doped carbon modified Pt/CNTs synthesized by atomic layer deposition with enhanced activity and stability for methanol electrooxidation

A Pt/CNTs catalyst coated with N‐doped carbon（xNC‐Pt/CNTs） is synthesized by atomic layer dep‐osition（ALD） and applied in methanol electrooxidation reaction. Pt nanoparticles and polyimide（PI） are sequentially deposited on carbon nanotubes（CNTs） by ALD. After annealing at 600 °C in H2 atmosphere, the PI is carbonized to produce porous N‐doped carbon. Upon coating with a moder‐ately thick layer of N‐doped carbon, the optimized 50 NC‐Pt/CNTs show higher activity, better long‐term stability, and improved CO resistance towards methanol electrooxidation compared with Pt/CNTs and commercial Pt/C（20 wt%）. X‐ray photoelectron spectroscopy characterization result indicates that the Pt–CO bond is weakened after N‐doped carbon coating and CO adsorption on the Pt surface is weakened, leading to superior electrocatalytic performance.

Effect of moisture content on the ultrasonic acoustic properties of wood

We determined the ultrasonic velocity and en- ergy attenuation value of three tree species （basswood, elm, and fir） 1 per tree in different moisture content levels, using RSM-SY5 ultrasonic testing instrument, and analyzed the regularity of ultrasonic velocity and energy attenuation values with moisture content, respectively. The ultrasonic velocity of the three species decreased as moisture content increased, with the turning point at 32 % of moisture content. When the moisture content was more than 32 %, the growth curve of ultrasonic wave velocity was flattened. The moisture contents of all three species increased under the any point moisture content of 1-60 %. The differen- tiation degrees of energy attenuation value of three species were higher than the corresponding ultrasonic wave ve- locity, when the moisture content was less than 15 %. The differentiation degrees of the energy attenuation value of three species was higher than the corresponding ultrasonic velocity, when the moisture content was more than 15 %.

EDTA-2Na和醋酸铜对Cu2S薄膜水热原位合成及光催化性能的影响

本文以硫脲为硫源采用水热法在铜片表面原位制备出Cu2S薄膜材料,采用XRD、SEM以及ABIOS表面光度仪等多种表征手段,分别考察了表面活性剂EDTA-2Na和醋酸铜对Cu2S薄膜晶体结构、形貌及表面粗糙度的影响,并进一步研究了不同条件下所得薄膜的光催化性能。结果表明,醋酸铜能够抑制Cu2S晶体树枝状生长,在降低薄膜表面粗糙度的同时也降低了薄膜的密实性;醋酸铜和表面活性剂共同作用能够在一定程度上提高晶体的致密性;只加入表面活性剂EDTA-2Na所获得的薄膜的光催化性能最好,对亚甲基蓝在80 min的光催化降解效率可达92.8%,主要是由于薄膜表面Cu2S分布均一、颗粒尺寸较小导致。

Union Resolution Performance of Frequency Modulation Parameter Based on RWT for LFM Signals

Union resolution performance of FM (frequency modulation) parameter based on Radon-Wigner transform (RWT) for multi-component LFM (linear frequency modulation) signals is studied. Firstly, the RWT output expression is offered, and the independent resolution performances of initial frequency and chirp rate are analyzed. Secondly, the RWT output approximate analytic expression is given based on quadratic Taylor's series expansion, and the contour property is analyzed. Contour can be used to picture the union resolution performance of FM parameter, and 2-D resolution performance is studied based on approximate analytic expression, and the union resolution expression of FM parameter and resolution ellipse are offered. The simulation results validate the union resolution expression, and show that the union resolution can improve the resolution performance of multi-component LFM signals, contrasted with absolute resolution performance. The paper can help the study of LFM parameter estimation and resolution performance.

水稻突变体pe-1对弱光胁迫的响应机制

以γ射线诱变籼稻双科早(Oryza sativa subsp.indica cv.‘Shuangkezao’)获得的早熟鲜绿突变体pe-1为实验材料,在三叶期和分蘖期进行弱光胁迫,探讨pe-1与野生型在形态特征、非生物胁迫相关酶活性及其调控基因表达量、叶绿素含量、叶绿体合成与降解及光形态建成相关基因表达对弱光响应的差异。结果表明,与野生型相比,弱光胁迫后,pe-1叶片黄化程度显著降低,株高和叶面积显著增加;三叶期和分蘖期的叶片中不同叶绿素含量变化不同。此外,pe-1叶绿素含量增加,且其抗氧化应激反应相关酶过氧化氢酶(CAT)和过氧化物酶(POD)的活性及相关基因的表达量均高于野生型,表明在弱光胁迫下pe-1活性氧清除能力增强,适应能力更强。pe-1的光形态建成相关基因表达量高于野生型,表明弱光处理下pe-1的光接收能力更强。综上,pe-1突变体具有抵御弱光胁迫的潜力,该结果有助于耐弱光水稻品种的选育。

Recent progress of in situ/operando characterization techniques for electrocatalytic energy conversion reaction

Catalysts can significantly promote the reaction dynamics and are therefore considered crucial components for achieving high electrochemical energy conversion efficiency.However,the active sites of the catalysts,particularly for nano-level and atomic-level catalysts commonly undergo reconstruction under practical applications.Therefore,obtaining an in-depth and systematic understanding on the real active sites through in situ/operando characterization techniques is a prerequisite for establishing the structureperformance relationship and guiding the future design of more efficient electrocatalysts.Herein,we summarize the recent progress of in situ/operando characterization techniques for identifying the nature of active sites of electrocatalysts when used in electrocatalytic energy conversion reaction.Specifically,our focus lies in the fundamental principles of various in situ/operando characterization techniques,with particular emphasis on their applications for electrocatalytic reactions.Beyond that,the challenges and perspective insights are also added in the final section to highlight the future direction of this important field.

水稻叶绿素含量QTL定位与候选基因表达分析

水稻(Oryza sativa)是我国主要粮食作物之一。提高水稻叶片叶绿素含量,进而提高其光合作用效率是实现高产稳产的重要途径之一。该研究以父系籼稻品种华占(HZ)、母系粳稻品种热研2号(Nekken2)及其构建的120个重组自交系(RILs)为实验材料,在分蘖期和成熟期分别对亲本及其后代剑叶的叶绿素含量(SPAD值)进行测定,同时基于已构建的高密度遗传连锁图谱进行QTL定位。结果共挖掘到20个与叶绿素含量相关的QTLs(分蘖期7个,成熟期13个),LOD值最高达4.77。利用qRT-PCR方法检测QTL区间内与叶绿素含量相关的候选基因的表达,发现LOC_Os06g11780、LOC_Os06g12360、LOC_Os06g39716、LOC_Os08g42610、LOC_Os02g18500、LOC_Os03g21240、LOC_Os03g21400、LOC_Os03g21780、LOC_Os03g30950及LOC_Os03g40550基因的表达量在双亲间差异显著。结合基因表达量及亲本叶绿素表型数据,推测LOC_Os06g11780、LOC_Os06g12360和LOC_Os08g42610的高表达极大地提高了水稻叶绿素含量,进而有效提高植物光合产能。研究结果为筛选和培育高光能利用效率的水稻新品种提供了有利的遗传资源,并为揭示水稻叶绿素含量的动态变化规律及分子调控机制奠定了重要基础。

Epidemic Characteristics,High-Risk Areas and Space-Time Clusters of Human Brucellosis—China,2020-2021

Introduction:Analyze the recent epidemiological and temporal-spatial characteristics of human brucellosis in China and provide information for adjusting strategies for brucellosis control.Methods:Human brucellosis data were obtained from the National Notifiable Disease Reporting System(NNDRS).A geographical information system(GIS)was used to visualize high-risk areas with annual incidence based on county(district)polygons.The space-time scan statistic(STSS)was applied to detect the space-time clusters of human brucellosis.Results:A total of 69,767 cases were reported from 2,083 counties in the mainland of China in 2021,a 47.7%increase from 2020(47,425).About 95.5%of the total cases were centralized in northern China and 31.8%in Inner Mongolia(IM).The number of counties with an incidence exceeding 100 per 100,000 was 34 in 2020 and 65 in 2021.From 2020 to 2021,24 space-time clusters were detected.The two primary clusters were located northeast of IM,including 109 counties.The secondary clusters affected 208 counties in 2020 and spread to 297 counties in 2021,the majority of which were located in the middle of IM,exhibiting a trend spreading west from IM to neighboring provincial-level administrative divisions(PLADs).Conclusions:From 2020 to 2021,the incidence of human brucellosis nationwide was exponential,demonstrating distinct spatiotemporal characteristics.Space-time clusters were located in IM and neighboring areas.Therefore,considerable efforts are required to curb this momentum.

Annealed microstructure dependent corrosion behavior of Ti-6Al-3Nb-2Zr-1Mo alloy

Corrosion resistance of titanium(Ti)alloys is closely connected with their microstructure which can be adjusted and controlled via different annealing schemes.Herein,we systematically investigate the specific effects of annealing on the corrosion performance of Ti-6 Al-3 Nb-2 Zr-1 Mo(Ti80)alloy in 3.5 wt.%NaCl and 5 M HCl solutions,respectively,based on open circuit potential(OCP),potentiodynamic polarization,electrochemical impedance spectroscopy(EIS),static immersion tests and surface analysis.Results indicate that increasing annealing tempe rature endows Ti80 alloy with a higher volume fraction ofβphase and finerαphase,which in turn improves its corrosion resistance.Surface characterization demonstrates thatβphase is more resistant to corrosion thanαphase owing to a higher content of Nb,Mo,and Zr in the former;additionally,the decreased thickness of a phase alleviates segregation of elements to further restrain the micro-galvanic couple effects betweenαandβphases.Meanwhile,the influential mechanisms of environmental conditions on corrosion of Ti80 alloy are discussed in detail.As the formation of a highly compact and stable oxide film on surface,annealed Ti80 alloys exhibit a low corrosion current density(10^(-6)A/cm^(2))and high polarization impedance(10^(6)Ω·cm^(2))in 3.5 wt.%NaCl solution.However,they suffer severe corrosion in 5 M HCl solution,resulting from the breakdown of native oxide films(the conversion of TiO_(2)to aqueous Ti^(3+)),active dissolution of substrate Ti to aqueous Ti^(3+)and existence of micro-galvanic couple effects.Those findings could provide new insights to designing Ti alloys with high-corrosion resistance through microstructural optimization.

Epidemiological Characteristics of Human Brucellosis-China,2016−2019

Introduction:Brucellosis is an important zoonotic infectious disease with its main mode of transmission from livestock to humans.The study analyzed epidemiological characteristics of human brucellosis from 2016 to 2019 in China,aiming to understand progress of the National Program of Brucellosis Prevention and Control.Methods:The research obtained data on human brucellosis cases reported through China’s National Notifiable Disease Reporting System(NNDRS)from January 1,2016 to December 31,2019 and described brucellosis epidemiological patterns by region,seasonality,age,sex,and occupation.Results:The number of cases reported nationwide in China decreased from 47,139(3.4/100,000)in 2016 to 37,947(2.7/100,000)in 2018,and then increased to 44,036(3.2/100,000)in 2019,with an average annual incidence of 3.0/100,000 during the four study years.Brucellosis in Xinjiang declined from 35.6/100,000 in 2016 to 16.3/100,000 in 2019-an average annual decrease of 22.9%.Brucellosis in Inner Mongolia increased from 23.8/100,000 in 2016 to 54.4/100,000 in 2019-an average increase of 31.8%per year and accounting for 22%of all reported cases.Northern China reported 95.2%of cases during this period and still had an incidence of 7.2/100,000 and 87.0%of counties being affected by brucellosis in 2019.In this region in 2019,males aged 45-64 years old had an incidence of over 15.9/100,000,compared with over 7.0/100,000 among females aged 45-64 years old.Conclusions:Although there was progress in prevention and control of human brucellosis in some provincial-level administrative divisions(PLADs)in 2016 through 2019,progress was limited nationwide and there was an overall resurgence of brucellosis in 2019.The resurgence was primarily in Inner Mongolia.An One Health approach should be strengthened to ensure successful and sustainable brucellosis prevention and control in China.

OShnscc:a novel user-friendly online survival analysis tool for head and neck squamous cell carcinoma based on RNA expression profiles and long-term survival information

Head and neck squamous cell carcinoma(HNSCC),as the most common type(>90%)of head and neck cancer,includes various epithelial malignancies that arise in the nasal cavity,oral cavity,pharynx,and larynx.In 2020,approximately 878000 new cases and 444000 deaths linked to HNSCC occurred worldwide(Sung et al.,2021).Due to the associated frequent recurrence and metastasis.

A universal strategy for the synthesis of porous twodimensional transition metal oxide nanosheets based on chemical topology transformation

Two-dimensional(2D)transition metal oxides(TMOs)have attracted much attention for various applications,owing to the abundance of active sites,rapid ion transmission speed,and short carrier migration distance.However,the current preparation strategies are usually limited to producing intrinsically layered compounds or sacrificing template.Here,we report a universal strategy for preparing ultrathin porous 2D TMO nanosheets by chemical topological transformation of the corresponding transition metal selenides.We observed that the as-prepared 2D TMO nanosheets not only perfectly inherit the transition metal selenides’2D topological structure,but also possess numerous pore structures formed as a way to release the structural stress associated with lattice growth.As a proof of concept,ultrathin porous WO_(3),Mo O_(3),and Co_(3)O_(4) nanosheets were successfully prepared based on the in-situ oxidation of the corresponding ultrathin WSe_(2),MoSe_(2),and Co_(0.85)Se,respectively.The outstanding sensing properties and photodetector performance displayed by the as-prepared porous 2D WO_(3) nanosheets further indicate the promising prospects of topology transformation for the preparation of porous 2D TMO nanosheets.