An intelligent prediction model of epidemic characters based on multi-feature

The epidemic characters of Omicron(e.g.large-scale transmission)are significantly different from the initial variants of COVID-19.The data generated by large-scale transmission is important to predict the trend of epidemic characters.However,the re-sults of current prediction models are inaccurate since they are not closely combined with the actual situation of Omicron transmission.In consequence,these inaccurate results have negative impacts on the process of the manufacturing and the service industry,for example,the production of masks and the recovery of the tourism industry.The authors have studied the epidemic characters in two ways,that is,investigation and prediction.First,a large amount of data is collected by utilising the Baidu index and conduct questionnaire survey concerning epidemic characters.Second,theβ-SEIDR model is established,where the population is classified as Susceptible,Exposed,Infected,Dead andβ-Recovered persons,to intelligently predict the epidemic characters of COVID-19.Note thatβ-Recovered persons denote that the Recovered persons may become Sus-ceptible persons with probabilityβ.The simulation results show that the model can accurately predict the epidemic characters.

Effect of Physical Intervention on Preventing Upper Limb Venous Thrombosis of Patients with PICC: A Systematic Review and Meta-Analysis of Randomized Trials

Objective: To evaluate the effect of physical methods on the prevention of venous thrombosis in patients with peripherally inserted central catheter (PICC). Methods: Randomized controlled trials meeting the inclusion and exclusion criteria were retrieved from the following databases: Cochrane library, Pubmed, EMbase, Web of science, Ovid, CBM, CNKI, Wanfang, VIP, then Review Manage (RevMan) 5.3 software was used for data analysis. Results: A total of 24 RCTs including 3496 patients were analyzed in the study. The results of meta-analysis showed that various forms of upper limb movements could effectively decrease the incidence of venous thrombosis in the patients with PICC [RR = 0.23, 95% CI (0.16, 0.33), P < 0.01], upper limb movements could effectively improve the mean blood flow velocity of basilic vein [MD = 1.65, 95% CI (1.19, 2.11), P < 0.01]. Conclusion: Upper limb movements can effectively decrease the incidence of phlebothrombosis and improve the mean flow velocity of basilic vein in the patients undergoing PICC. Other forms of physical prevention methods need to be further studied due to insufficient sample size.

Stability of Sanguinarine and Chelerythrine in Macleaya cordata (Willd.) R. Br.

[Objectives]To explore the stability of sanguinarine and chelerythrine in Macleaya cordata(Willd.)R.Br.[Methods]The solubility and stability of sanguinarine and chelerythrine in seven solvents were measured by HPLC.Besides,the effects of water quality,light source,oxidant,temperature,and pH on stability were investigated.[Results]The solubility and stability of sanguinarine and chelerythrine in methanol and ethanol are good;the stability of sanguinarine and chelerythrine in distilled water and rainwater is not affected by light and is very stable,but they are unstable in tap water whether they are protected from light or not;oxidants have a great influence on the stability of sanguinarine and chelerythrine;sanguinarine and chelerythrine are stable at room temperature lower than 54℃;sanguinarine is stable in pH 2.5-7.0,while chelerythrine is stable in pH 2.5-8.0.[Conclusions]The good stability of sanguinarine and chelerythrine under specific conditions shows that they have broad development prospects and value.

Eco-friendly glucose assisted structurally simplified high-efficiency tin-lead mixed perovskite solar cells

Achieving highly-efficient and stable perovskite solar cells(PSCs) with a simplified structure remains challenging, despite the tremendous potential for reducing preparation cost and facile processability by removing hole transport layer(HTL). In this work, eco-friendly glucose(Gl) as an interface modifier for HTL-free narrow bandgap tin-lead(Sn-Pb) PSCs is proposed. Gl not only enhances the wettability of the indium tin oxide to promote perovskite heterogeneous nucleation on substrate, but also realizes defect passivation by interacting with uncoordinated Pb^(2+) and Sn^(2+) in perovskite films. As a result, the quality of the perovskite films has been significantly improved, accompanied by reduced defects of bottom interface and optimized energy level structure of device, leading to an efficiency increase and a less nonradiative voltage loss of 0.102 V(for a bandgap of ~1.26 eV). Consequently, the optimized PSC delivers an unprecedented efficiency over 21% with high open-circuit voltage and enhanced stability, outperforming the control device. This work demonstrates a cost-effective approach to develop simplified structure high efficiency HTL-free Sn-Pb PSC.

Environment-friendly synthesis of N-phenylpiperidine from aniline and 1,5-pentanediol overγ-Al_2O_3 catalyst

An efficient environment-friendly synthesis of N-phenylpiperidine was developed from aniline and 1,5-pentanediol over γ-Al2O3 catalyst under atmospheric pressure. The conversion of 1,5-pentanediol reached 97% and the selectivity for N-phenylpiperidine attained 94%. The structure of the catalyst was characterized by NH3-TPD and BET. The influences of calcination temperature of the catalyst and reaction temperature on activity and selectivity of the catalyst were investigated.

Origin and evolution of a new tetraploid mangrove species in an intertidal zone

Polyploidy is a major factor in the evolution of plants,yet we know little about the origin and evolution of polyploidy in intertidal species.This study aimed to identify the evolutionary transitions in three truemangrove species of the genus Acanthus distributed in the Indo-West Pacific region.For this purpose,we took an integrative approach that combined data on morphology,cytology,climatic niche,phylogeny,and biogeography of 493 samples from 42 geographic sites.Our results show that the Acanthus ilicifolius lineage distributed east of the Thai-Malay Peninsula possesses a tetraploid karyotype,which is morphologically distinct from that of the lineage on the west side.The haplotype networks and phylogenetic trees for the chloroplast genome and eight nuclear genes reveal that the tetraploid species has two sub-genomes,one each from A.ilicifolius and A.ebracteatus,the paternal and maternal parents,respectively.Population structure analysis also supports the hybrid speciation history of the new tetraploid species.The two sub-genomes of the tetraploid species diverged from their diploid progenitors during the Pleistocene.Environmental niche models revealed that the tetraploid species not only occupied the near-entire niche space of the diploids,but also expanded into novel environments.Our findings suggest that A.ilicifolius species distributed on the east side of the Thai-Malay Peninsula should be regarded as a new species,A.tetraploideus,which originated from hybridization between A.ilicifolius and A.ebracteatus,followed by chromosome doubling.This is the first report of a true-mangrove allopolyploid species that can reproduce sexually and clonally reproduction,which explains the long-term adaptive potential of the species.

Gut microbiota intervention attenuates thermogenesis in broilers exposed to high temperature through modulation of the hypothalamic 5‑HT pathway

Background Broilers have a robust metabolism and high body temperature,which make them less tolerant to hightemperature(HT)environments and more susceptible to challenges from elevated temperatures.Gut microbes,functioning as symbionts within the host,possess the capacity to significantly regulate the physiological functions and environmental adaptability of the host.This study aims to investigate the effects of gut microbial intervention on the body temperature and thermogenesis of broilers at different ambient temperatures,as well as the underlying mechanism involving the"gut-brain"axis.Methods Broilers were subjected to gut microbiota interference with or without antibiotics(control or ABX)starting at 1 day of age.At 21 day of age,they were divided into 4 groups and exposed to different environments for 7 d:The control and ABX groups at room temperature(RT,24±1℃,60%relative humidity(RH),24 h/d)and the control-HT and ABX-HT groups at high temperature(HT,32±1℃,60%RH,24 h/d).Results The results demonstrated that the antibiotic-induced gut microbiota intervention increased body weight and improved feed conversion in broiler chickens(P<0.05).Under HT conditions,the microbiota intervention reduced the rectal temperature of broiler chickens(P<0.05),inhibited the expression of avUCP and thermogenesisrelated genes in breast muscle and liver(P<0.05),and thus decreased thermogenesis capacity.Furthermore,the gut microbiota intervention blunted the hypothalamic‒pituitary‒adrenal axis and hypothalamic–pituitary–thyroid axis activation induced by HT conditions.By analyzing the cecal microbiota composition of control and ABX chickens maintained under HT conditions,we found that Alistipes was enriched in control chickens.In contrast,antibioticinduced gut microbiota intervention resulted in a decrease in the relative abundance of Alistipes(P<0.05).Moreover,this difference was accompanied by increased hypothalamic 5-hydroxytryptamine(5-HT)content and TPH2 expression(P<0.05).Conclusions These findings underscore the critical role of the gut microbiota in regulating broiler thermogenesis via the gut-brain axis and suggest that the hypothalamic 5-HT pathway may be a potential mechanism by which the gut microbiota affects thermoregulation in broilers.

以金属有机骨架为源制备单原子电催化剂用于能量转换的最新进展

化石燃料的过度使用导致了严重的环境问题,因此,迫切需要人们对能源生产和储存方式进行变革.电催化在清洁能源转换中发挥着重要的作用,是推动可持续能源生产技术不断发展的重要驱动力.单原子催化剂(SACs)因具有独特的物理和化学性质而表现较高的电催化活性,因而成为研究热点.通过调控金属单原子的配位环境,可以有效调节SACs的几何和电子结构,进而优化电催化效率.金属有机骨架(MOFs)具有孔结构丰富、表面积大和配体可调节等结构特性,因此在制备SACs方面表现出巨大潜力.本文旨在总结以MOFs为前驱体制备SACs的最新进展,深入探讨单原子空间分布、配位结构和电子结构等局部配位环境对电催化活性的影响.此外,对密度泛函理论在研究SACs电催化反应中的应用进行了讨论和分析.本文系统地介绍了以MOFs为前驱体制备SACs的合成策略、表征方法、电催化应用和反应机理的研究进展,并对其未来的发展进行了展望.首先,概述了以MOFs为原料制备SACs的多种策略,分析了各自的优缺点及改进方向.然后,介绍了SACs的结构表征及电催化反应机理的原位表征技术,剖析了现有技术面临的挑战.再后,重点介绍了一些经典的制备SACs案例,对以MOFs为源制备的SACs在电催化析氢反应、析氧反应、氧还原反应、CO_(2)还原反应及氮还原消除等的应用进行了系统总结,并简要回顾了其在光催化、热催化、酶催化方向的应用.最后,探讨了SACs面临的挑战及解决方案:(1)目前采用的以MOFs为源制备SACs方法存在能耗高、污染环境等问题,应开发出环保可持续的合成方法以降低生产成本,并将其对环境的影响降到最低.(2)应利用原子水平控制技术制备双原子或三原子多功能电催化剂,并根据SACs的应用场景调整其配位结构,以优化性能.(3)需研发更先进的测试仪器,解决测试结果区域化、效率低、测试与实际结果存在偏差以及测试成本较高等问题.(4)基于SACs的结构特性,结合先进的测试仪器与理论计算,深入探究反应机理,为新一代电催化剂的设计提供指导.(5)随着信息技术的多维、多样和复杂化发展,可以借助机器学习,设计和开发新型SACs,推动电催化领域的持续创新.综上,本文系统地介绍了以MOFs为材料制备SACs的优势、设计原理、表征手段,并对SACs在电催化应用方面的研究进展与面临的挑战进行了总结,希望能为SACs相关方面的研究提供有价值的参考和借鉴.

Dykstra’s Algorithm for the Optimal Approximate Symmetric Positive Semidefinite Solution of a Class of Matrix Equations

Dykstra’s alternating projection algorithm was proposed to treat the problem of finding the projection of a given point onto the intersection of some closed convex sets. In this paper, we first apply Dykstra’s alternating projection algorithm to compute the optimal approximate symmetric positive semidefinite solution of the matrix equations AXB = E, CXD = F. If we choose the initial iterative matrix X0 = 0, the least Frobenius norm symmetric positive semidefinite solution of these matrix equations is obtained. A numerical example shows that the new algorithm is feasible and effective.

数控铣床磁流变减振装置及半主动模糊控制

机床振动是影响零件加工质量的主要原因,为此本文研制了可用于数控铣床的磁流变减振装置。本文在结构设计的基础上,并利用模糊控制算法对减振装置进行了基于磁流变阻尼减振器的机床系统控制研究,得出了较为满意的实验结果并作了相应的分析,验证了磁流变减振系统及算法的可行性。

新时代青年提升自我管理能力的路径探析

站在新发展阶段的新时代青年,需要担负起时代赋予的重任,青年们要对自己的目标、思想、心理和行为等等表象进行自我管理,自己把自己组织起来,管理自己、约束自己、激励自己,敢于斗争、善于斗争,最终实现自我奋斗目标。中国共产党第十九届六中全会审议通过了《中共中央关于党的百年奋斗重大成就和历史经验的决议》(以下简称《决议》),在其中汇总了党的百年奋斗重大成就和历史经验。《决议》用十个“坚持”概括了宝贵的历史经验,其中第八条明确指出:“坚持敢于斗争,是党和人民不可战胜的强大精神力量。”作为新时代的青年,认真学习贯彻落实《决议》中敢于斗争、善于斗争的精神,对于青年提升自我管理能力,加强青年的理想信念、坚持实践与理论的结合、培养青年吃苦耐劳的作风,以及提高自身修养有着重要的意义。

7例生物潜能未定非典型神经纤维瘤的临床病理学特征

目的:探讨生物潜能未定非典型神经纤维瘤(atypical neurofibromatous neoplasm of uncertain biologic potential,ANNUBP)的临床病理特征、免疫表型、分子遗传学改变。方法:分析2014年12月至2020年8月收集于北京大学国际医院病理诊断为非典型或富于细胞性神经纤维瘤14例患者的临床资料,其中7例具有ANNUBP的特征,光镜观察肿瘤细胞形态、免疫表型特征、并进行总结。结果:ANNUBP中男性5例,女性2例,年龄14~44岁(平均年龄27岁,中位年龄27岁);6例位于腹膜后,1例位于头颈部,最大径4.5~21.5 cm,平均11.0 cm,界限较清。镜下肿瘤细胞可见细胞异型性、丰富密集、失去神经纤维瘤结构和/或核分裂像增加(>1/50 HPF和<3/10 HPF);其中4例多次复发,2例进展为恶性外周神经鞘膜瘤(malignant peripheral nerve sheath tumor,MPNST),1例无瘤生存,复发率85.71%(6/7),恶变率28.57%(2/7);S-100、SOX-10、H3K27Me3在7例中均弥漫强表达,1例CD34染色显示网状结构消失,Ki-67增殖指数<2%~5%。结论:ANNUBP是具有较高复发率和恶变率的肿瘤,术后应结予相应的辅助治疗,并密切随访,同时也应避免过度治疗;结合免疫组织化学,有助于其诊断和鉴别诊断。

Forecast of Consumption and Emission of HFC-134a Used in the Mobile Air-conditioner Sector in China

HFC-134a is the most important alternative to CFC-12 used in the mobile air-conditioner sector in China. The con- sumption of HFC-134a has been increasing rapidly in recent years. It becomes the most consumed HFC in the sector. Selecting 2005 as the base line year, future consumption and emission amounts of HFC-134a are estimated through an analysis of a combined scenario： 1） replacement by non-HFC-134a blends, 2） good practice in servicing, 3） technology promotion, and 4） government policies on control of HFC-134a emissions. The analysis shows that HFC-134a consumption and emissions will continue to increase in the next 10 years. The projected HFC-134a consumption will approach 20,150 t and 34,875 t in 2010 and 2015 respectively, while the estimated emission amounts will reach 16,065 t and 30,186 t （i.e., 21 Mt CO2-eq and 39 Mt CO2-eq emissions） correspondingly. Compared with the business-as-usual scenario, the expected emission reductions in 2010 and 2015 will range between 6.7 Mt CO2-eq and 13.0 Mt CO2-eq.

Teacher Expectations for Student Learning in the Classroom

This paper is a discussion of the issues about teacher expectations for students＇ learning in the classroom. The discussion mainly focuses on such topics as the types of expectation effects, the sources of teacher expectations and the communication of teacher expectations. It is concluded that teacher expectations do play an important role in classroom teaching and learning, and therefore some suggestions are made for the peer teachers.

Anorectal Pharmacodynamics and In Vitro Drug Release of Clerodendrum bungei Steud.Extract Gel

[Objectives]To determine the optimal preparation technology of Clerodendrum bungei Steud.extract gel by orthogonal test and gel quality test method in General Rule 0114 of Chinese Pharmacopoeia(Volume IV,2020 Edition),and to study its anorectal pharmacodynamics and drug release in vitro.[Methods]Carbomer 940,propylene glycol and absolute ethyl alcohol were selected as the main factors,and the preparation technology of C.bungei Steud.extract gel was optimized by orthogonal test.The mouse model of ulcerative hemorrhoids was established with glacial acetic acid(HAC)and compared with Ma Yinglong musk hemorrhoids ointment.The recovery of trauma was compared between the two groups.At the same time,porcine small intestine was used as semi-permeable membrane to make diffusion cell to simulate anal environment,and the drug release in vitro was studied.[Results]The C.bungei Steud.extract gel was smooth in appearance and good in stability.It could effectively treat anal ulcer in mice and release quickly in vitro.[Conclusions]The formula is reasonable,and the effect of animal experiment is remarkable,which can provide a new treatment plan for ulcerative hemorrhoids.

Investigation on the Growth and Development of Muscle Fibers in Black Goat Lambs

[Objectives]This study was conducted to analyze and study the growth and development of muscle fibers at different stages,so as to provide a theoretical basis for subsequent research on developmental biology and nutritional regulation.[Methods]The body weights of black goat lambs in groups at different month age(0-6 months old)were recorded,and the diameter,area and number of muscle fibers were measured by tissue section and hematoxylin-eosin staining.The curves of body weight and muscle fiber growth and development of black goat lambs were drawn.[Results]The black goat lambs maintained a high absolute growth intensity of 2.95-4.35 kg/30 d throughout the rearing cycle,and the body weight continued to increase significantly,while the relative growth coefficient decreased from 93.05%at the age of 30 d to 13.83%at the age of 180 d.The diameter and area of muscle fibers in black goat lambs showed obvious"three-stage"growth and development characteristics,and showed different trends of gender advantages in different stages.[Conclusions]This study will help to further optimize the key supporting technologies for production and promote the diversified and comprehensive development of the mutton sheep industry in Sichuan Province.

The Properties of Elasticity, Thermology, and Anisotropy in Pd-Based Alloys

This work is devoted to investigate the elasticity, anisotropy, plastic properties, and thermal conductivity of PdSnYb, PdSn2Yb and Heusler alloy Pd2SnYb via employing the first-principles. The magnetic properties of Pd2SnYb, PdSnYb and PdSn2Yb are obtained by the geometry optimization combining with spin polarization. And the stability of these three kinds of materials is ensured by comparing with the enthalpy of formation and binding energy. The Fermi energy has same trend with stability. The details of bulk and Young’s modulus are demonstrated in 3D plots, embodied the elastic anisotropies of PdSnYb, PdSn2Yb, and Pd2SnYb. The calculations of plastic properties are also anisotropic. And the minimum thermal conductivities are small enough for these three materials to be used as thermal barrier coatings.

Amide proton transfer imaging of Alzheimer's disease and Parkinson's disease

Amide proton transfer (APT) magnetic resonance imaging (MRI) is an important molecularimaging technique at the protein level in tissue. Neurodegenerative diseases have a highlikelihood of causing abnormal protein accumulation in the brain, which can be detectedby APT MRI. This article briefly introduces the principles and image processing technologyof APT MRI, and reviews the current state of research on Alzheimer's disease and Parkinson's disease using this technique. Early applications of this approach in these twoneurodegenerative diseases are encouraging, which also suggests continued technicaldevelopment and larger clinical trials to gauge the value of this technique.

Alloy as advanced catalysts for electrocatalysis:From materials design to applications

With the deep integration of electrochemical research with energy,environment,catalysis,and other fields,more and more new electrochemical catalytic reactions have entered our research field.Alloy catalysts have recently emerged as a new type of nanomaterial due to the rapid development of kinetic controlled synthesis technology.These materials offer several advantages over monometallic catalysts,including larger element combinations,complex geometries,bifunctional sites,and reduced use of precious metals.This paper provides a review of alloy electrocatalysts that are designed and prepared specifically for electrocatalytic applications.The use of alloy materials in electrocatalyst design is also discussed,highlighting their widespread application in this field.First,various synthesis methods and synthesis mechanisms are systematically summarized.Following that,by correlating the properties of materials with the structure,relevant strategies toward advanced alloy electrocatalysts including composition regulation,size,morphology,surface engineering,defect engineering,interface engineering and strain engineering are classified.In addition,the important electrocatalytic applications and mechanisms of alloy electrocatalysts are described and summarized.Finally,the current challenges and prospects regarding the development of alloy nanomaterials are proposed.This review serves as a springboard from a fundamental understanding of alloy structural dynamics to design and various applications of electrocatalysts,particularly in energy and environmental sustainability.

Safety,immunogenicity,and preliminary efficacy of a randomized clinical trial ofomicron XBB.1.5-containing bivalent mRNA vaccine

Periodically updating coronavirus disease 19(COVID-19)vaccines that offer broad-spectrum protection is needed giventhe strong immune evasion by the circulating omicron sublineages.The effectiveness of prototype and BA.4/5-containing bivalent mRNA vaccines is reduced when XBB subvariants predominate.We initiated an observer-blinded,threearms study in 376 patients in Chinese individuals aged from 18 to 55 years old who had previously received three dosesCOVID-19 vaccine.Immunogenicity in terms of neutralizing antibodies elicited by a 30-mg dose of XBB.1.5-containingbivalent vaccine(RQ3027),a 30-mg dose of BA.2/BA.5-Alpha/Beta bivalent vaccine(RQ3025)and their precedent 30-mg Alpha/Beta(combined mutations)monovalent mRNA vaccine(RQ3013)and safety are primary and secondary endpoints,respectively.We recorded prescribed COVID-19 cases to explore the preliminary efficacy of three vaccines.RQ3027 and RQ3025 boosters elicited superior neutralizing antibodies(NAbs)against XBB.1.5,XBB.1.16,XBB.1.9.1,and JN.1 compared to RQ3013 at day 14 in participants without SARS-CoV-2 infection.All study vaccines were welltolerated without serious adverse reactions identified.The incidence rates per 1000 person-years of COVID-19 casesduring the 2nd-19th week after randomization were lowest in RQ3027.Overall,our data show that XBB.1.5-containingbivalent booster generated superior immunogenicity and better protection against newer severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variants compared to BA.2/BA.5-containing bivalent and Alpha/Beta monovalentwith no new safety concerns.