利用和频振动光谱探索蛋白质与多肽界面结构的最新研究进展

蛋白质和多肽的界面结构在各种生物过程和技术发展中发挥着重要作用。对这些结构的深入了解对于疾病诊断、药物输送和生物材料的研究至关重要.然而,这些体系的复杂性以及分析方法的局限性限制了其深入研究.尽管X射线晶体学和低温电子显微镜等先进技术在分析蛋白质结构方面做出了重大贡献,但对于实际条件下表面结合蛋白质结构的理解仍然有限,这也为该领域带来了挑战。和频振动光谱技术已经成为分析蛋白质界面分子结构的一种强有力的手段.本文简要介绍和频振动光谱学的基本原理,探讨其在相位测量方面的研究进展,并概述了近三年(2021~2023)的研究成果,展示了和频振动光谱在揭示多肽和蛋白质界面分子结构方面的潜力:本文为进一步利用和频振动光谱探索不同类型的多肽和蛋白质在界面上的结构和功能提供了有利的支持。

Dynamical Analysis of an SIS Epidemic Integrodifference Model

In order to analyze the impact of dispersal on disease transmission, we establish an SIS epidemic integrodifference model with a nonlinear incidence function. Firstly, the discrete-time SIS epidemic model is established and studied, including the existence and stability of equilibria, the existence of a flip bifurcation, and chaos. Secondly, the SIS epidemic integrodifference model is built based on the discrete-time SIS epidemic model with dispersal. The dynamic analysis of the model includes the existence and stability of equilibria, the existence of a traveling wave solution, and a minus-one bifurcation. Finally, the results suggest that dispersal causes the system to become more unstable and accelerates the spread of the disease when the equilibrium is unstable. Numerical examples are provided to demonstrate the theoretical results.

Finite-Time Sideslip Differentiator-Based LOS Guidance for Robust Path Following of Snake Robots

This paper presents a finite-time sideslip differentiator-based line-of-sight(LOS)guidance method for robust path following of snake robots.Firstly,finite-time stable sideslip differentiator and adaptive LOS guidance method are proposed to counteract sideslip drift caused by cross-track velocity.The proposed differentiator can accurately observe the cross-track error and sideslip angle for snake robots to avoid errors caused by calculating sideslip angle approximately.In our method,the designed piecewise auxiliary function guarantees the finite-time stability of position errors.Secondly,for the case of external disturbances and state constraints,a Barrier Lyapunov functionbased backstepping adaptive path following controller is presented to improve the robot’s robustness.The uniform ultimate boundedness of the closed-loop system is proved by analyzing stability.Additionally,a gait frequency adjustment-based virtual velocity control input is derived to achieve the exponential convergence of the tangential velocity.At last,the availability and superiority of this work are shown through simulation and experiment results.

Selective ischemic-hemisphere targeting Ginkgolide B liposomes with improved solubility and therapeutic efficacy for cerebral ischemia-reperfusion injury

Cerebral ischemia-reperfusion injury(CI/RI)remains the main cause of disability and death in stroke patients due to lack of effective therapeutic strategies.One of the main issues related to CI/RI treatment is the presence of the blood-brain barrier(BBB),which affects the intracerebral delivery of drugs.Ginkgolide B(GB),a major bioactive component in commercially available products of Ginkgo biloba,has been shown significance in CI/RI treatment by regulating inflammatory pathways,oxidative damage,and metabolic disturbance,and seems to be a candidate for stroke recovery.However,limited by its poor hydrophilicity and lipophilicity,the development of GB preparations with good solubility,stability,and the ability to cross the BBB remains a challenge.Herein,we propose a combinatorial strategy by conjugating GB with highly lipophilic docosahexaenoic acid(DHA)to obtain a covalent complex GB-DHA,which can not only enhance the pharmacological effect of GB,but can also be encapsulated in liposomes stably.The amount of finally constructed Lipo@GB-DHA targeting to ischemic hemisphere was validated 2.2 times that of free solution in middle cerebral artery occlusion(MCAO)rats.Compared to the marketed ginkgolide injection,Lipo@GB-DHA significantly reduced infarct volume with better neurobehavioral recovery in MCAO rats after being intravenously administered both at 2 h and 6 h post-reperfusion.Low levels of reactive oxygen species(ROS)and high neuron survival in vitro was maintained via Lipo@GB-DHA treatment,while microglia in the ischemic brain were polarized from the pro-inflammatory M1 phenotype to the tissue-repairing M2 phenotype,which modulate neuroinflammatory and angiogenesis.In addition,Lipo@GB-DHA inhibited neuronal apoptosis via regulating the apoptotic pathway and maintained homeostasis by activating the autophagy pathway.Thus,transforming GB into a lipophilic complex and loading it into liposomes provides a promising nanomedicine strategy with excellent CI/RI therapeutic efficacy and industrialization prospects.

Large-scale CO(J=1-0)Observations toward the M120.1+3.0 Molecular Cloud:A Filament with a Chain of Starburst Clusters

We present large-scale(2°×2°)observations toward the molecular cloud M120.1+3.0,using ^(12)CO,^(13)CO and C^(18)O(J=1-0)data from the Purple Mountain Observatory 13.7 m millimeter telescope.The distance of the cloud is measured to be~1.1 kpc.Using the ^(13)CO data,we identify a main filament F1 and two sub-filaments F2 and F3 in the cloud,which together show a"hub-filament"structure.Filaments F1 and F2 are thermally supercritical.Furthermore,F1 displays clear localized systematic motions in the ^(13)CO position-velocity diagram,which could be explained by accretion along the filament.The mean estimated accretion rate is~132M_(⊙)Myr^(-1).Approximately 150 ^(13)CO clumps are identified in the cloud,of which 39 are gravitationally bound.Most of these virialized clumps are well distributed along the supercritical filaments F1 and F2.Based on the complementary infrared and optical data,we identify~186 young stellar objects in the observed area and extract five clusters within the dense ridge of F1.The calculated star formation rate(SFR)surface densities(∑_(SFR))in the clusters range from 1.4 to 2.5 M_(⊙)Myr^(-1)pc^(-2),with a mean value of~2.0M_(⊙)Myr^(-1)pc^(-2).We therefore regard them as mini-starburst cluster candidates.The comparison between ∑_(SFR) and column density N_(gas) along the skeleton of F1 suggests that star formation is closely related to the dense gas in the cloud.Along the main filament F1,five bipolar outflows are also found.All these results indicate intense star-forming activities in the M120.1+3.0 molecular cloud.

Ultrathin and Air-Stable Lithium Metal Anodes with Superlong Cycling Life in Ether/Ester-Based Electrolytes

Ultrathin and air-stable Li metal anodes hold great promise toward high-energy and high-safety Li metal batteries(LMBs).However,the application of LMBs is technically impeded by existing Li metal anodes with large thickness,high reactivity,and poor performance.Here,we developed a novel and scalable approach for the construction of a 10-μm-thick flexible and air-stable Li metal anode by conformally encapsulating Li within a multifunctional VN film.Specifically,the highly lithiophilic VN layer guides a uniform deposition of Li,while abundant and multilevel pores arising from assembly of ultrathin nanosheets enable a spatially confined immersion of metallic Li,thus ensuring an ultrathin and sandwiched Li anode.More impressively,the strong hydrophobicity of VN surface can effectively improve the stability of anode to humid air,whereas the highly conductive framework greatly boosts charge transfer dynamics and enhances Li utilization and high-rate capability.Benefiting from such fascinating features,the constructed Li-VN anode exhibits ultrastable cycling stability in both ether(2500 h)and carbonate(900 h)electrolytes,respectively.Moreover,even exposed to ambient air for 12 h,the anode still can retain~78%capacity,demonstrating excellent air-defendable capability.This work affords a promising strategy for fabricating high-performance,high-safety,and low-cost LMBs.

Genetic architecture of leaf morphology revealed by integrated trait module in Catalpa bungei

Leaves are crucial for maintaining plant growth and development via photosynthesis,and their function is simultaneously regulated by a suite of phenotypic traits.Although much is known about the genetic architecture of individual leaf traits,unraveling the genetic basis of complex leafmorphology remains a challenge.Based on the functional correlation and coordination ofmulti-traits,we divided 15 leaf morphological traits into three modules,comprising size(area,length,width,and perimeter),shape(leaf lobes,aspect ratio,circularity,rectangularity,and the relevant ratios),and color(red,green,and blue)for an ornamental tree species,Catalpa bungei.A total of 189 significant single-nucleotide polymorphisms were identified in the leaves of C.bungei:35,82,and 76 in the size,shape,and color modules,respectively.Four quantitative trait loci were common between the size and shape modules,which were closely related according to phenotype correlation,genetic mapping,and mRNA analysis.The color module was independent of them.Synergistic changes in the aspect ratio,leaf lobe,and circularity suggest that these traits could be the core indicators of the leaf shape module.The LAS and SRK genes,associated with leaf lobe and circularity,were found to function in plant defense mechanisms and the growth of leaves.The associations between the SRK and CRK2 genes and the leaf lobe and circularity traits were further verified by RT-qPCR.Our findings demonstrate the importance of integrating multi-trait modules to characterize leaf morphology and facilitate a holistic understanding of the genetic architecture of intraspecific leaf morphology diversity.

Research Progress in Surface and Marine Gravimetry

Gravity field is the most basic physical field generated by the material properties of the Earth system.It reflects the spatial distribution,movement and change of materials determined by the interaction and dynamic process inside the Earth.Over the years,a variety of technical means have been used to detect the Earth’s gravity field and supported numerous studies on the global change,resource detection,geological structure movement,water resources change and other related fields of research.Here is part of the progress in surface and marine gravimetry obtained by Chinese geodesy scientists from 2019 to 2023 from the following aspects,including:①Continuous gravity network in Chinese mainland;②Application of superconducting gravity measurement;③Network adjustment for continental-scale gravity survey campaign and data quality control;④Regional time-variable gravity field and its application;⑤Research progress on novel technologies for gravity inversion;⑥Research progress on marine gravity field determination;⑦Application research on marine gravity field.

Discussion on the Main Reasons for a Large Number of Père David s Deer ( Elaphurus davidianus ) with Abnormal Antler Shedding

[Objectives]This study was conducted to find out the causes of abnormal antler shedding in Père David s deer(Elaphurus davidianus).[Methods]Abnormally-shed antlers were compared with normally-shed antlers in terms of light condition,antler development and bone nutritional status during the abnormal shedding season in the growth area of Père David s deer.[Results]Abnormally-shed antlers had no significant differences in the development of shed antlers,or even in the overall composition of antlers,from those of normal Père David s deer.[Conclusions]Insufficient light was the main cause of abnormal antler shedding in Père David s deer.

关于畜牧兽医专业群人才需求与专业改革的调研报告

2019年新年伊始,国务院就颁布了“国家职业教育改革实施方案(国发〔2019〕4号)”,自此中国职业教育将驶入内涵建设的快车道。紧接着国家启动实施中国特色高水平高等职业学校和骨干专业(群)建设计划,这表明专业群建设将是形成高职院校核心竞争力的关键。

Heterogeneous expectations,IPO Underpricing and issuing mechanism

Background:Compared with the fixed-price mechanism,the bookbuilding mechanism has not changed the Chinese IPO high underpricing.How to develop scientific and reasonable IPO pricing,and reduce the high IPO underpricing has become a major challenge for China's securities market.Methods:In this paper,using behavioral finance theory and game theory,we build the Initial public offering(IPO)pricing and underpricing models with investors’heterogeneity based on different issuing mechanisms and provide a comparative analysis.Results:Firstly,our models show that IPO underpricing will not be eliminated by using either fixed-price or bookbuilding mechanisms,but when the investors’heterogeneity expectation is the same,lower IPO underpricing can be obtained by the issuing of bookbuilding compared with that of fixed price.Secondly,the IPO underpricing may be larger than that under fixed price if the heterogeneity of investors under bookbuilding is larger than that under fixed price.Thirdly,the numerical analysis results provide strong support for our model.Conclusions:These findings further explains the cause of the high IPO underpricing long-standing in China.

Determination of Inorganic Anions and Melamine in Fertilizers by Ion Chromatography

A chromatographic analysis method for determining inorganic anions and melamine in fertilizers was established using ion chromatography(IC).The fertilizer samples were extracted by ultrasonic method with 7 g/L trichloroacetic acid solution and centrifuged.The supernatant is purified by a solid phase extraction column.Then,the anions in the solution were purified using SH-AP-1(250 mm×4.0 mm)as a separation column,and measured by a suppressed conductivity detector;the melamine in the solution was separated using SH-CC-4(200 mm×4.0 mm)as a separation column and detected by a UV detector.The results show that the mass concentration of anions had a linear relationship with its peak area within a certain range,the linear correlation coefficient r of the standard curve was greater than 0.999,the recovery rate of spiked samples was 93.4%-104.4%,and the relative standard deviation(RSD)of the measured value(n=6)was less than 4%.Thus,this method is widely suitable for detection of anions and cations in a variety of fertilizer samples.

Research on Interactive Learning and Teaching based on Computer Network

This paper analyzes the basic interactivity connotation of network teaching from the interactive definition, function, types and level etc., and established the interaction quality evaluation index system from the four angles between student and media, the course content, teacher and peer interaction. Similarly, network instruction interaction also needs to carry on the design from the perspective of instructional design, and take full advantage of the Internet, and finally achieved good network interaction effect. Practice shows that, research on network interactive strategy significance.

Research Application of Patient-Reported Outcomes in Assessing the Nutritional Status of Patients with Gastrointestinal Tumors

Objective:To investigate and analyze the changes of nutritional status in patients undergoing postoperative adjuvant chemotherapy for gastrointestinal tumors based on patient-reported outcomes.Methods:From July 2020 to March 2021,60 patients with gastrointestinal tumor who received adjuvant chemotherapy for the first time after surgery under the oncology department of a third-level,first-class hospital in Shaanxi Province were recruited by convenience sampling.The patient-reported nutritional evaluation outcomes within 24 hours after admission and during the fourth chemotherapy cycle incorporated nutritional risk screening 2002(NRS2002),Functional Assessment of Anorexia/Cachexia Therapy(FAACT),psychological pain screening,Generalized Anxiety Disorder Assessment(GAD-7),Patient Health Questionnaire-9(PHQ-9)to screen for depression,dietary self-assessment,health index scale(EQ-5D),and nutrition supervisor overall assessment scale.Results:The self-reported nutritional evaluation outcomes by adjuvant chemotherapy patients showed an upward trend along with their chemotherapy cycle.Their PG-SGA score,FAACT score,psychological pain score,and EQ-5D score during the fourth cycle were better than those during the first chemotherapy cycle(p<0.05)・Conclusion:Based on the patient・reported nutritional evaluation outcomes,the nutritional status and quality of life of patients with gastrointestinal tumors during chemotherapy did not worsen.Medical staff should timely evaluate the nutritional status of patients with gastrointestinal tumors during chemotherapy and implement reasonable nutritional intervention to improve the quality of life of patients.In the future,patient-reported outcomes should be considered for integration into clinical practice in order to facilitate patient participation in decision-making and improve their medical experience.

水相中银催化硝基化合物还原制备胺

芳胺是重要的基础化学品,被广泛应用于材料、药物化学等领域.发展新型、高效的催化合成策略制备芳香伯胺具有重要的科学研究意义.本文以商业易得的芳香硝基化合物为原料、廉价的三氟甲磺酸银为催化剂前体、苯硅烷为还原剂,在水相且温和条件下,实现了硝基的高选择性还原.该体系具有较好的兼容性,后处理操作简单,避免了氢气及高压釜设备,为芳香伯胺的制备提供了新的思路.机理研究表明,原位生成的银氢为活性物种,将硝基芳烃转化成为相应的芳香亚硝基化合物,中间体为偶氮苯及氢化偶氮苯.

Reversing cancer immunoediting phases with a tumor-activated and optically reinforced immunoscaffold

In situ vaccine(ISV)is a promising immunotherapeutic tactic due to its complete tumoral antigenic repertoire.However,its efficiency is limited by extrinsic inevitable immunosuppression and intrinsic immunogenicity scarcity.To break this plight,a tumor-activated and optically reinforced immunoscaffold(TURN)is exploited to trigger cancer immunoediting phases regression,thus levering potent systemic antitumor immune responses.Upon response to tumoral reactive oxygen species,TURN will first release RGX-104 to attenuate excessive immunosuppressive cells and cytokines,and thus immunosuppression falls and immunogenicity rises.Subsequently,intermittent laser irradiation-activated photothermal agents(PL)trigger abundant tumor antigens exposure,which causes immunogenicity springs and preliminary infiltration of T cells.Finally,CD137 agonists from TURN further promotes the proliferation,function,and survival of T cells for durable antitumor effects.Therefore,cancer immunoediting phases reverse and systemic antitumor immune responses occur.TURN achieves over 90%tumor growth inhibition in both primary and secondary tumor lesions,induces potent systemic immune responses,and triggers superior long-term immune memory in vivo.Taken together,TURN provides a prospective sight for ISV from the perspective of immunoediting phases.

Concise Synthesis of Lactococcus garvieae Lipoteichoic Acids Through an Additive-Modulated Preactivation Protocol and the Immunological Studies

Lipoteichoic acids(LTAs)are macroamphiphiles composed of alditol,lipid,phosphate,and carbohydrate units.Due to their inherent complexity,it is a severe challenge to access LTAs with structural integrity from natural sources for biological or immunological evaluation.Here,we describe the first total synthesis of Lactococcus garvieae LTA(type II LTA),containing five distinct 1,2-cis gluco/galactopyranosidic linkages,via a novel additive-modulated O-glycosyl trichloroacetimidate preactivation glycosidation strategy.This strategy features(1)high glycosidation yields and excellent 1,2-cis stereoselectivities independent of the donor anomeric configuration,(2)common and inexpensive reagents as promoters and additives,(3)application to standard glycosyl imidate donors without resorting to participating protection,and(4)general application to reactive and less reactive glycosyl acceptors.Thus,via the precise stereocontrolled construction of three galactopyranosidic and two glucopyranosidic bonds on a multigram scale,a series of structurally well-defined LTA molecules were successfully assembled.Immunological evaluation of these type II synthetic LTAs showed a structure–activity relationship in the stimulation of a proinflammatory response.

Strategies for improving extraction capacity through preorganization structure:A novel 5,6-bicyclicmalonamide extractant(THPPD)

Rational design of extractant structure to improve the extraction and separation capacity of rare earth elements(REEs)is a long-standing challenge.Herein,a new strategy was proposed to improve the stability of the chelating structure formed by malonamide and REEs.The stability of the chelating structure is greatly improved by using a double-ring framework structure which makes the two carbonyl groups of malonamide unable to rotate freely and both of them point to the metal ion position.Three benzyl groups were used to construct the hydrophobicity of the extractant and the organic shell of the extracted species.Tribenzylhexahydro-pyrrolo-pyridine-dione(THPPD)was designed and synthesized.The structure reduces the energy consumed by rotating carbonyl group in the coordination with metal ions and then improves the extraction ability of extractant.The crystal structure was preorganized as expected,with the two carbonyls pointing in a favorable coordination direction to the structural complement of the metal ion.The extraction behaviors of REEs with THPPD in a nitric acid medium were studied.Compared with N,N’-dibenzyl-N,N’-dimethylmalonamide(DBDM-MA)with a chain structure,the extraction capacity of THPPD is 360 times higher than that of DBDM-MA at 5.0 mol/L sodium nitrate.Furthermore,the binding energy and Gibbs free energy were investigated by density functional theory(DFT)in conjunction with the B3LYP.The theoretical results show that THPPD has more effective interaction with Pr(NO_(3))3 than DBDM-MA.The construction of chelating groups conformation is a worthy direction to improve the coordination ability and even selectivity of extractant.

磁压榨吻合技术治疗结直肠吻合及重建中的应用分析

回顾磁压榨吻合技术(magnetic compression anastomosis,MCA)治疗不同原因、不同类型肠道狭窄/闭锁实现肠道再通的案例,对MCA在结直肠吻合及重建中的临床应用进行分析探讨。4例患者2019年5月—2022年8月在西安交通大学第一附属医院及西北妇女儿童医院行结直肠MCA再通治疗。患者手术过程均顺利,实现肠道吻合再通,磁环排出时间为7~15 d,术后复查肠镜或造影提示吻合口完好。MCA可用于治疗不同原因、不同类型的结直肠狭窄及闭锁,也可用于辅助结直肠手术肠吻合。

Science with the 2.5-meter Wide Field Survey Telescope(WFST)

The Wide Field Survey Telescope(WFST) is a dedicated photometric surveying facility being built jointly by University of Science and Technology of China(USTC) and the Purple Mountain Observatory(PMO). It is equipped with a 2.5-meter diameter primary mirror, an active optics system, and a mosaic CCD camera with 0.73 gigapixels on the primary focal plane for highquality image capture over a 6.5-square-degree field of view. The installation of WFST near the summit of Saishiteng mountain in the Lenghu region is scheduled in summer of 2023, and the operation is planned to start three months later. WFST will scan the northern sky in four optical bands(u, g, r and i) at cadences from hourly/daily in the deep high-cadence survey(DHS) program, to semi-weekly in the wide field survey(WFS) program. During a photometric night, a nominal 30 s exposure in the WFS program will reach a depth of 22.27, 23.32, 22.84, and 22.31(AB magnitudes) in these four bands, respectively, allowing for the detection of a tremendous amount of transients in the low-z universe and a systematic investigation of the variability of Galactic and extragalactic objects. In the DHS program, intranight 90 s exposures as deep as 23(u) and 24 mag(g), in combination with target of opportunity follow-ups, will provide a unique opportunity to explore energetic transients in demand for high sensitivities, including the electromagnetic counterparts of gravitational wave events, supernovae within a few hours of their explosions,tidal disruption events and fast, luminous optical transients even beyond redshift of unity. In addition, the final 6-year co-added images, anticipated to reach g■25.8 mag in WFS or 1.5 mags deeper in DHS, will be of fundamental importance to general Galactic and extragalactic science. The highly uniform legacy surveys of WFST will serve as an indispensable complement to those of the Vera C. Rubin Observatory's Legacy Survey of Space and Time(LSST) that monitors the southern sky.