Effects of renal sympathetic denervation on cardiac systolic function after myocardial infarction in rats

This study investigated the therapeutic effects of renal denervation on cardiac systolic function after myocardial infarction （MI） in rats and the mechanism involved. Fifty male SD rats were randomly assigned to the sham group （n = 15）, the MI group （n = 20）, and the MI plus renal denervation group （n = 15）. MI was established through thoracotomic ligation of the anterior descending artery. Renal denervation was achieved by laparotomic stripping of the renal arterial adventitial sympathetic nerve, approximately 3 mm from the abdominal aorta. Left ventricular function and hemodynamics were measured several weeks following MI. The left ventricular systolic function of the MI group was significantly reduced and the systolic blood pressure （SBP） remarkably declined. In rats with MI treated with renal denervation, the left ventricular ejection fraction （EF）, fractional shortening （FS） and SBP markedly improved compared with the MI group. However, heart rate and fibrosis decreased significantly. These findings suggest that renal denervation has therapeutic effects on post-MI cardiac dysfunction. These effects are associated with increased left ventricular ejection fraction （LVEF） and SBP, as well as reduced heart rate and fibrosis. This may represent a new approach to the treatment of post-MI remodeling and subsequent heart failure.

C_(6)H自由基B^(2)Π-X^(2)Π的O_(0)^(0)带光谱的Λ型双重分裂和寿命展宽

本文利用狭缝超声射流等离子体结合高灵敏腔衰荡光谱在18990 cm^(-1)附近研究了C6H碳链自由基B^(2)Π-X^(2)Π电子跃迀000带谱带的高分辨光谱.通过采用一套自研的窄线宽纳秒脉冲激光光源,首次在实验上观测到了该电子跃迁谱带的A型转动线分裂,获得了B^(2)Π态精确的A型双重分裂光谱常数p’=-1.16(9)×10^(-3)cm^(-1)和q’=-1.22(7)×10^(-4)cm^(-1),并更精确地确定了考虑A型分裂后修正的B、D、γ等光谱常数.基于谱线线形展宽,获得了B^(2)Π的能级寿命~100±20 ps,并分析了其可能的来源机理.

TiO_2/石墨烯纳米复合材料对UV固化水性聚氨酯的改性

通过溶胶-凝胶法制备了锐钛矿型的纳米TiO_2,用改进的Hummers法制备了氧化石墨烯,用水热法合成了纳米TiO_2/石墨烯复合材料。采用异佛尔酮二异氰酸酯和聚乙二醇1000为反应单体,二月桂酸二丁基锡为催化剂,二羟甲基丙酸作为扩链剂,并以甲基丙烯酸羟乙酯封端,成功制备出水性聚氨酯预聚体。将TiO_2/石墨烯复合材料引入UV固化聚氨酯体系,制备了含有不同质量分数复合材料的聚氨酯涂层。采用扫描电子显微镜、X射线粉末衍射、傅里叶变换红外光谱、紫外-可见分光光度计等手段对样品进行表征,分析了材料的形貌、组成、结构及光催化降解性能。结果表明,TiO_2/石墨烯复合材料改性水性聚氨酯涂料表现出了较好的光催化性能。280nm紫外光照射下24h之内对甲基橙降解率达到77.20%,而在可见光条件下复合材料对甲基橙降解率达到57.52%。经改性的聚氨酯涂层的各项力学性能有了不同程度的提高。

Combination of multi-focus Raman spectroscopy and compressive sensing for parallel monitoring of single-cell dynamics

To overcome the low efficiency of conventional confocal Raman spectroscopy,many efforts have been devoted to parallelizing the Raman excitation and acquisition,in which the scattering from multiple foci is projected onto different locations on a spectrometer's CCD,along either its vertical,horizontal dimension,or even both.While the latter projection scheme relieves the limitation on the row numbers of the CCD,the spectra of multiple foci are recorded in one spectral channel,resulting in spectral overlapping.Here,we developed a method under a com-pressive sensing framework to demultiplex the superimposed spectra of multiple cells during their dynamic processes.Unlike the previous methods which ignore the information connection be-tween the spectra of the cells recorded at different time,the proposed method utilizes a prior that a cell's spectra acquired at different time have the same sparsity structure in their principal components.Rather than independently demultiplexing the mixed spectra at the individual time intervals,the method demultiplexes the whole spectral sequence acquired continuously during the dynamic process.By penalizing the sparsity combined from all time intervals,the collaborative optimization of the inversion problem gave more accurate recovery results.The performances of the method were substantiated by a 1D Raman tweezers array,which monitored the germination of multiple bacterial spores.The method can be extended to the monitoring of many living cells randomly scattering on a coverslip,and has a potential to improve the throughput by a few orders.

Preparation of Activated Carbon Based on Straw and Its Adsorption on Sunset Yellow

The removal effect of sunset yellow by the activated carbon prepared by modified straw was studied, and the effects of adsorption temperature, adsorption time, adsorption capacity, solution salinity and solution pH on the removal effect of sunset yellow were analyzed. After being soaked in acid and alkali, the stalks and leaves of the straw were carbonized and modified at 200-700 ℃. The results show that the adsorption effect of the leaves soaked in alkali was the best when the carbonization temperature was 700 ℃. As the adsorption temperature was 30-40 ℃, the adsorption effect of sunset yellow was the best. With the increase of adsorption time, the removal rate of sunset yellow first increased, then decreased, and finally rose again. The first critical point was about 30 min. When the dosage of activated carbon was 0.7 g, the adsorption effect of 50 ml of sunset yellow solution was the best. The optimal solution salinity was 60%. pH had a small effect on the adsorption of sunset yellow, showing a fluctuating trend.

Tetrafunctional Cu2S thin layers on Cu2O nanowires for efficient photoelectrochemical water splitting

Photoelectrochemical （PEC） water splitting by photocathodes based on p-type semiconductors is a promising process for direct and efficient hydrogen generation. The identification of ideal photocathode materials with a high photoconversion efficiency and long-term stability is still a significant challenge. Herein, we propose a new photocathode consisting of Cu2S-coated Cu2O nanowires （NWs） supported on a three-dimensional porous copper foam. The Cu2S thin layer is generated in situ on the surface of the Cu2O NWs and has four functions： （1） sensitizer, with a band gap of 1.2 eV, for extending the range of optical absorption into the near-infrared region; （2） electron trapper, with appropriate energy level alignment to Cu2O, for achieving effective electron transfer and trapping; （3） electrocatalyst, with excellent electrocatalytic activity for the hydrogen evolution reaction; and （4） protector, preventing direct contact between Cu2O and the electrolyte in order to significantly increase the stability. A photocathode based on the tetrafunctional Cu2S-coated Cu2O NWs exhibits significantly enhanced PEC performance and remarkably improved long-term stability under illumination. The present strategy, based on the in situ generation of multifunctional layers, opens a new avenue for the rational design of photocathodes for PEC water reduction.

Dual-functional hydrogen-bonded organic frameworks for aniline and ultraviolet sensitive detection

A novel hydrogen-bonded organic frameworks(HOFs)FJU-200 has been constructed from N,N’-bis(5-isophthalic acid)naphthalimide(H_(4)L).FJU-200 has a good dual-function of aniline and ultraviolet detection.FJU-200 is the first case of HOF with dual sensing of visual color changes and photoluminescence quenching for aniline detection,and the detection limit of aniline can reach5.5 x 10^(-4)mol/L.Under ultraviolet FJU-200 will rapidly change from light yellow to rustic brown,which makes it possible to use FJU-200 to achieve minute-level ultraviolet detection.Moreover,for more convenient use,FJU-200 test papers are prepared.Using them,convenient and fast aniline or ultraviolet detection can be realized.The single-crystal X-ray structures show that compared with the original FJU-200,both PhNH_(2)@FJU-200 and UV-FJU-200 have larger pore sizes,and the dihedral angles of the H_(2)L^(2-)in framework has been changed.

破译pH值和金属离子编程的家蚕纺丝机制

Silk is one of the toughest fibrous materials known despite spun at ambient temperature and pressure with water as a solvent.It is a great challenge to reproduce high-performance artificial fibers comparable to natural silk by bionic for the incomplete understanding of silkworm spinning in vivo.Here,we found that amphipol and digitonin stabilized the structure of natural silk fibroin(NSF)by a large-scale screening in vitro,and then studied the close-to-native ultrastructure and hierarchical assembly of NSF in the silk gland lumen.Our study showed that NSF formed reversible flexible nanofibrils mainly composed of random coils with a sedimentation coefficient of 5.8 S and a diameter of about 4 nm,rather than a micellar or rod-like structure assembled by the aggregation of globular NSF molecules.Metal ions were required for NSF nanofibril formation.The successive p H decrease from posterior silk gland(PSG)to anterior silk gland(ASG)resulted in a gradual increase in NSF hydrophobicity,thus inducing the sol-gelation transition of NSF nanofibrils.NSF nanofibrils were randomly dispersed from PSG to ASG-1,and self-assembled into anisotropic herringbone patterns at ASG-2 near the spinneret ready for silkworm spinning.Our findings reveal the controlled self-assembly mechanism of the multi-scale hierarchical architecture of NSF from nanofibrils to herringbone patterns programmed by metal ions and p H gradient,which provides novel insights into the spinning mechanism of silk-secreting animals and bioinspired design of high-performance fibers.

Photoluminescence and photothermal conversion in boric acid derived carbon dots for targeted microbial theranostics

Theranostic carbon dots(CDs)have attracted widespread attention recently due to their tunable optical properties and diverse bioactivities.Beyond fluorescent imaging application,the photothermal property endows CDs with the potential for microbial inactivation.However,realization of the effective conversion between fluorescence and heat in one CD system has rarely been reported.Herein,we provide a simple strategy for targeted microbial theranostics based on 4-carboxyphenylboronic acid-derived CDs(PCBA-CDs)which possess concentration-dependent photoluminescence/photothermal features.At lower concentrations,PCBA-CDs show bright and stable fluorescent signals ranging from blue to green.The fluorescence intensity gradually decreases with increasing concentration,while on the contrary,the photothermal effect of PCBA-CDs ascends progressively due to the rearrangement of electronic transitions in aggregated CDs.PCBA-CDs also demonstrate high affinity to the polysaccharide structures on the surface of microbe which allows rapid microbial fluorescence imaging as well as specific photothermal ablation of pathogens in skin wounds using PCBA-CDs at lower and higher concentrations,respectively.This study supplies a facile nanotheranostic strategy for just-in-time microbial management using bioactive CDs.

基于红外相机的不可个体识别动物种群密度估算方法

种群密度估计对野生动物的保护和管理至关重要,也是动物生态学和保护生物学备受关注的研究热点,但对大中型兽类种群数量的准确估算一直面临挑战。红外相机是哺乳动物调查中普遍采用的工具,也是克服这一挑战的一种经济有效的方法。目前国际上已有多种方法采用红外相机数据估算不可个体识别动物的种群密度,但相关技术在我国的应用案例较少,本文旨在为国内研究者应用红外相机数据估算动物种群密度提供参考。首先,我们介绍了随机相遇模型(randomencounter model,REM)、随机相遇与停留时间(random encounter and staying time,REST)模型、相机前停留时间(time in front of the camera,TIFC)模型以及红外相机距离取样(cameratrapdistancesampling,CTDS)这四种模型的基本原理和假设;其次,描述了这些模型在野外调查中的技术要点,并给出数据处理与分析的建议;最后,总结了每个模型的数据需求、优点和缺点。虽然我国目前拥有估算种群密度的大量红外相机数据源,但有很多物种的数量尚未知晓,也没有一种方法对所有红外相机数据都是最优的,所以我们建议研究者在了解所研究动物类群的生活史和生态需求基础上,根据模型假设确定合理的采样和分析方案,扩大这些方法的应用,为我国重要物种的保护和保护地建设提供科学指导。

鸟类迁徙对图们江下游湿地声景时间格局的影响

声景生态学是一个相对较新和快速发展的研究领域,被动声学监测技术和声学指数已经成为研究湿地鸟类和声景多样性的重要方法。本研究评价了鸟类迁徙对中国东北图们江流域下游湿地声景日、月和季节变化的影响。我们从2020年11月至2021年12月在图们江下游敬信湿地设置10个采样点,获得91,988条时长5min的有效音频,计算了声音复杂度指数(acoustic complexity index,ACI)、生物声学指数(bioacoustic index,BIO)、声音均匀度指数(acoustic evenness index,AEI)和标准化声景差异指数(normalized difference soundscape index,NDSI)以及1–11 k Hz频段的功率谱密度(power spectral density,PSD)。结果表明,声学指数对鸟类迁徙活动敏感,其中2个迁徙期声景(2–4月和10–11月)都以1–2k Hz雁类白天的叫声为主,NDSI显著降低,1–2k Hz的PSD显著升高,但雁类向北迁徙时几个声学指数变化更为敏感,有效地捕获了迁徙峰值,表明不同季节鸟类迁徙模式存在差异。非迁徙期声景由夏候鸟、蛙类和昆虫发声为主,4种声学指数和PSD随月份呈现不同的动态特征,反映了声景的多样性和复杂性,其中5–7月声景以2–11 k Hz的夏候鸟鸣唱(呈现显著高的黎明和鸣行为)和2–3 k Hz的蛙类鸣叫为主,8–9月声景以2–3 k Hz、4–5 k Hz和6–10 k Hz频段的夜间昆虫鸣叫为主,12月至次年1月仅记录到少量的鸟类发声活动。综上所述,图们江下游湿地声景呈现明显的日和月变化规律,多种声学指数联合使用可以有效地监测迁徙鸟类物候的变化,特别是追踪春季雁类向北迁徙的时间和规模。随着全球气候变暖,我们的结果强调声景监测与声学指数的应用可成为监测迁徙鸟类群落对气候变化响应的有效方法。

大环内酯类抗生素微生物降解的研究进展

大环内酯类抗生素是一类以大环内酯为母核的广谱抗生素。近些年,由于人们对其不规范的生产和使用,抗生素污染成为了重要的环境问题。大量研究表明,微生物降解是现阶段处理抗生素污染的最理想方法。为进一步推动大环内酯类抗生素生物降解的研究,文中概述了大环内酯类抗生素的环境污染现状、微生物降解菌株、降解酶、降解途径和降解大环内酯类抗生素的微生物处理方法,并对大环内酯类抗生素生物降解亟待解决的瓶颈问题进行了讨论,以期为微生物降解后续研究提供参考。

人工智能的伦理关切与治理路径

人工智能技术在全球范围内的快速迭代,显著提升了人类福祉,同时也催生了诸如操纵、“黑箱”、歧视、隐私、责任困境等伦理问题。人工智能伦理作为科技伦理的一部分,成为全球科技发展与治理的前沿议题。它的核心价值可以提炼为:自主决定、安全可靠、透明公开、隐私保护、公平公正、责任担当。我国作为人工智能产业大国,近年来对人工智能伦理的重视也已上升到国家层面。当前以及未来的人工智能伦理治理,应在我国人工智能发展规划下,以六大核心价值为方向构建人工智能的伦理治理体系:一方面,完善人工智能的“硬”约束,即在法律意义上约束和规范人工智能活动;另一方面,建立人工智能治理的“软”约束,包括确认人工智能的风险及其治理的目标机制、方案等不具有法律约束的倡议,推动技术进步更好地服务于人类社会。

硝基咪唑杂环药物化学研究进展

硝基咪唑是一类特殊结构的杂环,五元芳香杂环咪唑与硝基的共缀使其衍生物呈现广泛的应用潜力,在药物、人工诊断剂与人工探针等相关领域研究异常活跃,尤其是在医药方面作为人工合成的化学药物已在临床中广泛用于抗癌、抗菌、抗寄生虫等,备受关注.本文结合本课题组相关研究,参考国内外近期文献,系统地综述了硝基咪唑类化合物在药物化学领域的研究与应用,包括抗肿瘤、抗细菌、抗真菌、抗寄生虫、抗结核、抗高血压以及作为人工诊断剂与病理探针、超分子基体等领域的当前现状,展望了其未来可能的发展趋势.希望该评述能为硝基咪唑类杂环化合物的多用途开发提供有益的指导.

First small-molecule PROTACs for G protein-coupled receptors:inducing α1A-adrenergic receptor degradation

Proteolysis targeting chimeras(PROTACs)are dual-functional hybrid molecules that can selectively recruit an E3 ubiquitin ligase to a target protein to direct the protein into the ubiquitinproteasome system(UPS),thereby selectively reducing the target protein level by the ubiquitinproteasome pathway.Nowadays,small-molecule PROTACs are gaining popularity as tools to desrade pathogenic protein.Herein,we present the first small-molecule PROTACs that can induce the alA-adrenergic receptor(α1 A-AR)degradation,which is also the first small-molecule PROTACs for G proteincoupled receptors(GPCRs)to our knowledge.These degradation inducers were developed through conjugation of knownα1-adrenergic receptors(α1-ARs)inhibitor prazosin and cereblon(CRBN)ligand pomalidomide through the different linkers.The representative compound 9 c is proved to inhibit the proliferation of PC-3 cells and result in tumor growth regression,which highlighted the potential of our study as a new therapeutic strategy for prostate cancer.

Room-temperature chlorine gas sensor based on CdSnO_(3) synthesized by hydrothermal process

The perovskite-structure CdSnO_(3) was obtained by calcinating CdSnO_(3)·3H_(2)O precursor at 550℃,which was synthesized by hydrothermal process at 170℃for 16 h.The phase and microstructure of the obtained CdSnO_(3) powders were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM)and transmission electron microscopy(TEM).The CdSnO_(3) powders exhibit uniformly cubic structure with side length of about 100 nm.The effects of working temperature and concentration of detected gas on the gas response were studied.The selectivity of chlorine gas against other gases and response-recovery time of the sensor were also investigated.The results reveal that the CdSnO_(3) gas sensor has enhanced sensing properties to 1-10 ppm chlorine gas at room temperature;the value of gas response can reach 1338.9 to 5 ppm chlorine gas.Moreover,the sensor shows good selectivity and quick response behavior(23 s)to chlorine gas,indicating its application in detecting chlorine gas at room temperature in the future.

A Runge Kutta Discontinuous Galerkin Method for Lagrangian Compressible Euler Equations in Two-Dimensions

This paper presents a new Lagrangian type scheme for solving the Euler equations of compressible gas dynamics.In this new scheme the system of equations is discretized by Runge-Kutta Discontinuous Galerkin(RKDG)method,and the mesh moves with the fluid flow.The scheme is conservative for the mass,momentum and total energy and maintains second-order accuracy.The scheme avoids solving the geometrical part and has free parameters.Results of some numerical tests are presented to demonstrate the accuracy and the non-oscillatory property of the scheme.

Elemene sensitizes pancreatic cancer cells to bortezomib by enhancing proteasome inhibition via molecular patch mechanism

Dear Editor,Pancreatic cancer*is one of the deadliest cancers,with an overall 5-year survival rate of less than 10%unchanged over the last 40 years.Approximately 80-85%of patients are diagnosed as advanced stage,which are not eligible for curative surgery.1 Therapeutic options for advanced pancreatic cancer patients are still chemotherapy drugs with limited outcomes to improve patient survival and life quality.

Investigation of multilayer domains in large-scale CVD monolayer graphene by optical imaging

CVD graphene is a promising candidate for optoelectronic applications due to its high quality and high yield.However,multi-layer domains could inevitably form at the nucleation centers during the growth.Here,we propose an optical imaging technique to precisely identify the multilayer domains and also the ratio of their coverage in large-scale CVD monolayer graphene.We have also shown that the stacking disorder in twisted bilayer graphene as well as the impurities on the graphene surface could be distinguished by optical imaging.Finally,we investigated the effects of bilayer domains on the optical and electrical properties of CVD graphene,and found that the carrier mobility of CVD graphene is seriously limited by scattering from bilayer domains.Our results could be useful for guiding future optoelectronic applications of large-scale CVD graphene.

The poly(ADP-ribosyl)ation of BRD4 mediated by PARP1 promoted pathological cardiac hypertrophy

The bromodomain and extraterminal(BET)family member BRD4 is pivotal in the pathogenesis of cardiac hypertrophy.BRD4 induces hypertrophic gene expression by binding to the acetylated chromatin,facilitating the phosphorylation of RNA polymerases II(Pol II)and leading to transcription elongation.The present study identified a novel post-translational modification of BRD4:poly(ADPribosyl)ation(PARylation),that was mediated by poly(ADP-ribose)polymerase-1(PARP1)in cardiac hypertrophy.BRD4 silencing or BET inhibitors JQ1 and MS417 prevented cardiac hypertrophic responses induced by isoproterenol(ISO),whereas overexpression of BRD4 promoted cardiac hypertrophy,confirming the critical role of BRD4 in pathological cardiac hypertrophy.PARP1 was activated in ISOinduced cardiac hypertrophy and facilitated the development of cardiac hypertrophy.BRD4 was involved in the prohypertrophic effect of PARP1,as implied by the observations that BRD4 inhibition or silencing reversed PARP1-induced hypertrophic responses,and that BRD4 overexpression suppressed the antihypertrophic effect of PARP1 inhibitors.Interactions of BRD4 and PARP1 were observed by coimmunoprecipitation and immunofluorescence.PARylation of BRD4 induced by PARP1 was investigated by PARylation assays.In response to hypertrophic stimuli like ISO,PARylation level of BRD4 was elevated,along with enhanced interactions between BRD4 and PARP1.By investigating the PARylation of truncation mutants of BRD4,the C-terminal domain(CTD)was identified as the PARylation modification sites of BRD4.PARylation of BRD4 facilitated its binding to the transcription start sites(TSS)of hypertrophic genes,resulting in enhanced phosphorylation of RNA Pol II and transcription activation of hypertrophic genes.The present findings suggest that strategies targeting inhibition of PARP1-BRD4 might have therapeutic potential for pathological cardiac hypertrophy.