海上移动平台直升机甲板圆管支撑结构安全评估

圆管支撑结构是海上移动式平台直升机甲板设计的重要部分,由于海上恶劣的风浪环境,使结构整体受风载荷的影响较大.现有直升机甲板圆管支撑结构的安全评估内容主要集中于圆管的静强度分析,缺乏风振响应分析,文中以海洋石油163平台直升机甲板为例,研究圆管支撑结构的静力和动力载荷输入,通过有限元强度分析和理论经验公式计算对比静力、风载荷作用下直升机甲板圆管支撑结构的受力情况,考虑风振涡激效应的准静态分析,在此基础上提出了直升机甲板圆管支撑结构的安全评估方法,探究了风载荷对结构整体安全的影响.

西欧兔“碳循”世界

随着国家“双碳”战略的推进,作为“主角”的二氧化碳(CO_(2))逐渐被人们所关注。然而,大众对CO_(2)循环及碳减排等缺乏系统、深入的理解。本实验开发了一套碳循环实验,包含CO_(2)的性质、产生、转化及捕集,通过光合作用和化学吸收等分别模拟自然界与工业固碳减排过程,实现碳减排、碳中和。通过指示剂变色、喷泉及沉淀等多种形式展示CO_(2)的变化过程。实验原料多取自生活,操作简单;互动方案丰富,趣味性高,生动科普碳循环的化学原理,普及“双碳”知识,让低碳节能理念深入人心。

“双碳”相关实验开发——蛋壳源CaO的制备、表征及其碳捕集性能

碳捕集技术是实现“双碳”目标的重要途径。高温工业源CO_(2)的捕集更宜使用钙基吸收剂。本文立足“双碳”背景,将碳捕集前沿技术融入仪器分析实验课程,开发了蛋壳源CaO的制备、表征及其碳捕集性能的设计性综合实验。选择高钙废弃物鸡蛋壳为原料,采用醋酸处理得到醋酸钙,再经高温煅烧制备了具有较好碳捕集性能的CaO;利用EDTA配位滴定、扫描电子显微镜、X射线衍射、红外光谱、拉曼光谱和热重分析等多种分析手段,测试了CaO的纯度、形貌、结构及其对CO_(2)的捕集性能。本实验采用项目式教学方式,引导学生自行设计实验方案并进行实践和总结,不仅锻炼了学生综合运用专业知识解决实际问题的能力,而且培养了学生的科研素养和团队合作精神。

Overexpression of wild-type HRAS drives non-alcoholic steatohepatitis to hepatocellular carcinoma in mice

Hepatocellular carcinoma(HCC),a prevalent solid carcinoma of significant concern,is an aggressive and often fatal disease with increasing global incidence rates and poor therapeutic outcomes.The etiology and pathological progression of non-alcoholic steatohepatitis(NASH)-related HCC is multifactorial and multistage.However,no single animal model can accurately mimic the full NASH-related HCC pathological progression,posing considerable challenges to transition and mechanistic studies.Herein,a novel conditional inducible wild-type human HRAS overexpressed mouse model(HRAS-HCC)was established,demonstrating 100%morbidity and mortality within approximately one month under normal dietary and lifestyle conditions.Advanced symptoms of HCC such as ascites,thrombus,internal hemorrhage,jaundice,and lung metastasis were successfully replicated in mice.In-depth pathological features of NASH-related HCC were demonstrated by pathological staining,biochemical analyses,and typical marker gene detections.Combined murine anti-PD-1 and sorafenib treatment effectively prolonged mouse survival,further confirming the accuracy and reliability of the model.Based on protein-protein interaction(PPI)network and RNA sequencing analyses,we speculated that overexpression of HRAS may initiate the THBS1-COL4A3 axis to induce NASH with severe fibrosis,with subsequent progression to HCC.Collectively,our study successfully duplicated natural sequential progression in a single murine model over a very short period,providing an accurate and reliable preclinical tool for therapeutic evaluations targeting the NASH to HCC continuum.

A Survey on an Emerging Safety Challenge for Autonomous Vehicles:Safety of the Intended Functionality

As the complexity of autonomous vehicles(AVs)continues to increase and artificial intelligence algorithms are becoming increasingly ubiquitous,a novel safety concern known as the safety of the intended functionality(SOTIF)has emerged,presenting significant challenges to the widespread deployment of AVs.SOTIF focuses on issues arising from the functional insufficiencies of the AVs’intended functionality or its implementation,apart from conventional safety considerations.From the systems engineering standpoint,this study offers a comprehensive exploration of the SOTIF landscape by reviewing academic research,practical activities,challenges,and perspectives across the development,verification,validation,and operation phases.Academic research encompasses system-level SOTIF studies and algorithm-related SOTIF issues and solutions.Moreover,it encapsulates practical SOTIF activities undertaken by corporations,government entities,and academic institutions spanning international and Chinese contexts,focusing on the overarching methodologies and practices in different phases.Finally,the paper presents future challenges and outlook pertaining to the development,verification,validation,and operation phases,motivating stakeholders to address the remaining obstacles and challenges.

A rice exocyst subunit gene SEC3A is required for anther dehiscence

Anther dehiscence controls optimal interaction between pollen and stigma,thereby determining the successful sexual reproduction.The regulators or mechanisms of this process remain elusive.Here,two CRISPR/Cas9 mutants of a rice exocyst subunit gene SEC3A,sec3a-1 and sec3a-2,showed anther indehiscence at anthesis and male sterility at maturity.Pollen viability and germination in the mutants were partly defective,whereas their female gametes undergone a normal development.Hybrid or self-pollinated seeds could be produced by artificial pollination,suggesting potential use of a weak sec3a mutant as a female line during hybrid breeding.SEC3A is widely expressed in various tissues,including anther walls.Further results showed an excessive IAA accumulation and no endothecium lignification in sec3a-1/2 anthers.Our findings suggest that SEC3A appears to regulate anther dehiscence by modulating auxin signaling,providing insights into regulation of anther dehiscence and function of exocyst in plants.

Light-modulated graphene-based φ_(0) Josephson junction and -φ_(0) to φ_(0) transition

We investigate the chiral edge states-induced Josephson current–phase relation in a graphene-based Josephson junction modulated by the off-resonant circularly polarized light and the staggered sublattice potential.By solving the Bogoliubov–de Gennes equation,a φ_(0) Josephson junction is induced in the coaction of the off-resonant circularly polarized light and the staggered sublattice potential,which arises from the fact that the center of-mass wave vector of Cooper pair becomes finite and the opposite center of-mass wave vector to compensate is lacking in the nonsuperconducting region.Interestingly,when the direction of polarization of light is changed,-φ_(0) to φ_(0) transition generates,which generalizes the concept of traditional 0–πtransition.Our findings provide a purely optical way to manipulate a phase-controllable Josephson device and guidelines for future experiments to confirm the presence of graphene-based φ_(0)Josephson junction.

Photocatalytic seawater splitting by 2D heterostructure of ZnIn_(2)S_(4)/WO_(3) decorated with plasmonic Au for hydrogen evolution under visible light

Photocatalytic H_(2) evolution from seawater splitting presents a promising approach to tackle the fossil energy crisis and mitigate carbon emission due to the abundant source of seawater and sunlight on the earth.However,the development of efficient photocatalysts for seawater splitting remains a formidable challenge.Herein,a 2D/2D ZnIn_(2)S_(4)/WO_(3)(ZIS/WO_(3))heterojunction nanostructure is fabricated to efficiently separate the photoinduced carriers by steering electron transfer from the conduction band minimum of WO_(3) to the valence band maximum of ZIS via constructing internal electric field.Subsequently,plasmonic Au nanoparticles(NPs)as a novel photosensitizer and a reduction cocatalyst are anchored on ZIS/WO_(3) surface to further enhance the optical absorption of ZIS/WO_(3) heterojunction and accelerate the catalytic conversion.The obtained Au/ZIS/WO_(3) photocatalyst exhibits an outstanding H_(2) evolution rate of 2610.6 or 3566.3μmol g^(-1)h~(-1)from seawater splitting under visible or full-spectrum light irradiation,respectively.These rates represent an impressive increase of approximately 7.3-and 6,6-fold compared to those of ZIS under the illumination of the same light source.The unique 2D/2D structure,internal electric field,and plasmonic metal modification together boost the photocatalytic H_(2) evolution rate of Au/ZIS/WO_(3),making it even comparable to H_(2) evolution from pure water splitting.The present work sheds light on the development of efficient photocatalysts for seawater splitting.

Pars plana vitrectomy for retinal detachment using perfluoro-n-octane as intraoperative tamponade:a multicenter,randomized,non-inferiority trial

AIM:To evaluate the efficacy and safety of perfluoro-n-octane(PFO)for ophthalmic surgery versus F-Octane as an intraoperative tamponade in pars plana vitrectomy(PPV)in management of retinal detachment.METHODS:This multicenter,prospective,randomized,double-masked,parallel-controlled,non-inferiority trial was conducted in three ophthalmology clinical centers in China.Patients with retinal detachment,who were eligible for PPV were consecutively enrolled.Participants were assigned to PFO for ophthalmic surgery or F-Octane for intraocular tamponade in a 1:1 ratio.Best-corrected visual acuity(BCVA),intraocular pressure(IOP)measurement,and dilated fundus examination were performed preoperatively and at 1,7±1,28±3d postoperatively.The primary outcome was complete retinal reattachment rate at postoperative day one.The non-inferiority margin was set at 9.8%.The secondary outcomes included intraoperative retinal reattachment rate,and mean changes in IOP and BCVA from baseline to 1,7±1,28±3d postoperatively,respectively.Safety analyses were presented for all randomly assigned participates in this study.RESULTS:Totally 124 eligible patients completed the study between Mar.14,2016 and Jun.7,2017.Sixty of them were randomly assigned to the PFO for ophthalmic surgery group,and 64 were assigned to the F-Octane group.Baseline characteristics were comparable between the two groups.Both groups achieved 100%retinal reattachment at postoperative day one(difference 0,95%CI:-6.21%to 5.75%,P=1).The pre-defined noninferiority criterion was met.No significant difference was observed in intraoperative retinal reattachment rate(difference 1.77%,P=0.61),mean changes in IOP(difference 0.36,-0.09,2.22 mm Hg at 1,7±1,28±3d postoperatively,with all P>0.05)and BCVA(difference 0.04,-0.02,0.06 logMAR at 1,7±1,28±3d postoperatively,all P>0.05)between the two groups.No apparent adverse events related to the utilization of PFO were reported.CONCLUSION:In patients with retinal detachment undergoing PPV,PFO for ophthalmic surgery is non-inferior to F-Octane as an intraocular tamponade,and both are safe and well-tolerated.

Single-cell transcriptome sequencing reveals the mechanism regulating rice plumule development

Seed plumules comprise multiple developing tissues and are key sites for above-ground plant organ morphogenesis.Here,the spatial expression of genes in developing rice seed plumules was characterized by single-cell transcriptome sequencing in Zhongjiazao 17,a popular Chinese indica rice cultivar.Of 15 cell clusters,13 were assigned to cell types using marker genes and cluster-specific genes.Marker genes of multiple cell types were expressed in several clusters,suggesting a complex developmental system.Some genes for signaling by phytohormones such as abscisic acid were highly expressed in specific clusters.Various cis-elements in the promoters of genes specifically expressed in cell clusters were calculated,and some key hormone-related motifs were frequent in certain clusters.Spatial expression patterns of genes involved in rapid seed germination,seedling growth,and development were identified.These findings enhanced our understanding of cellular diversity and specialization within plumules of rice,a monocotyledonous model crop.

A polygalacturonase gene OsPG1 modulates water homeostasis in rice

A dynamic plant architecture is the basis of plant adaptation to changing environments.Although many genes regulating leaf rolling have been identified,genes directly associated with water homeostasis are largely unknown.Here,we isolated a rice mutant,dynamic leaf rolling 1(dlr1),characterized by‘leaf unfolding in the morning-leaf rolling at noon-leaf unfolding in the evening’during a sunny day.Water content was decreased in rolled leaves and water sprayed on leaves caused reopening,indicating that in vivo water deficiency induced the leaf rolling.Map-based cloning and expression tests demonstrated that an A1400G single base mutation in Oryza sativa Polygalacturonase 1(OsPG1)/PHOTO-SENSITIVE LEAF ROLLING 1(PSL1)was responsible for the dynamic leaf rolling phenotype in the dlr1 mutant.OsPG1 encodes a polygalacturonase,one of the main enzymes that degrade demethylesterified homogalacturonans in plant cell walls.OsPG1 was constitutively expressed in various tissues and was enriched in stomata.Mutants of the OsPG1 gene exhibited defects in stomatal closure and decreased stomatal density,leading to reduced transpiration and excessive water loss under specific conditions,but had normal root development.Further analysis revealed that mutation of OsPG1 led to reduced pectinase activity in the leaves and increased demethylesterified homogalacturonans in guard cells.Our findings reveal a mechanism by which OsPG1 modulates water homeostasis to control dynamic leaf rolling,providing insights for plants to adapt to environmental variation.

Editorial for the Special Issue on Safety for Intelligent and Connected Vehicles

Intelligent and connected vehicles(ICVs)are confronted with critically complex traffic scenarios and safety challenges that have attracted increasing attention from academia and industry.The intelligent safety of ICVs involves several technologies and requires the common efforts of researchers and engineers,including the safety of the intended functionality(SOTIF),the safety of artificial intelligence,the intricacies of cybersecurity,and ethical dilemmas.Ensuring the intelligent safety of ICVs presents substantial chal-lenges in both research and commercialization,particularly SOTIF,which refers to the absence of unreasonable risk owing to hazards resulting from functional insufficiencies of the intended functiona-lity or reasonably foreseeable misuse by person.Because of the limited scene coverage ability of training samples and the practical application conditions without boundary restrictions,it is very dif-ficult to find the functional insufficiency of the intended function-ality and overcome it under dynamic unknown scenarios,which is also the source of SOTIF.

β-Receptor blocker enhances the anabolic effect of PTH after osteoporotic fracture

The autonomic nervous system plays a crucial role in regulating bone metabolism,with sympathetic activation stimulating bone resorption and inhibiting bone formation.We found that fractures lead to increased sympathetic tone,enhanced osteoclast resorption,decreased osteoblast formation,and thus hastened systemic bone loss in ovariectomized(OVX)mice.However,the combined administration of parathyroid hormone(PTH)and theβ-receptor blocker propranolol dramatically promoted systemic bone formation and osteoporotic fracture healing in OVX mice.The effect of this treatment is superior to that of treatment with PTH or propranolol alone.In vitro,the sympathetic neurotransmitter norepinephrine(NE)suppressed PTH-induced osteoblast differentiation and mineralization,which was rescued by propranolol.Moreover,NE decreased the PTH-induced expression of Runx2 but enhanced the expression of Rankl and the effect of PTH-stimulated osteoblasts on osteoclastic differentiation,whereas these effects were reversed by propranolol.Furthermore,PTH increased the expression of the circadian clock gene Bmal1,which was inhibited by NE-βAR signaling.Bmal1 knockdown blocked the rescue effect of propranolol on the NE-induced decrease in PTHstimulated osteoblast differentiation.Taken together,these results suggest that propranolol enhances the anabolic effect of PTH in preventing systemic bone loss following osteoporotic fracture by blocking the negative effects of sympathetic signaling on PTH anabolism.

Extracorporeal membrane oxygenation versus cardiopulmonary bypass during transcatheter aortic valve implantation: a meta-analysis of survival benefits

Since its approval by the Food and Drug Administration in 2011,transcatheter aortic valve implantation(TAVI)has rapidly evolved to become the preferred ultimate intervention for high-and intermediate-risk patients with severe symptomatic aortic stenosis.[1]This is due to its non-open-heart,minimally invasive and off-pump advantages.[1]Nevertheless,as a result of the frequent frailty and comorbidity profiles of patients undergoing TAVI,such as advanced cardiac dysfunction and extensive coronary artery disease,or technically difficult anatomy for the procedure itself,[2-4]it is common for these patients to experience critical circulatory collapse perioperatively.These factors are linked to elevated mortality rates,necessitating suitable mechanical circulatory support(MCS)to reverse the disastrous situations.[5]

Survey on the Demand for Elderly Care Services of Community Residents in Beijing and Analysis of Influencing Factors

Objective: To investigate the current situation of the demand for geriatric care services of community residents in Beijing and analyze the influencing factors to provide a reference basis for meeting the demand for diversified and professional geriatric care services. Methods: A self-made questionnaire was used to randomly survey 1558 elderly individuals at community health service centers in 8 urban districts where elderly care centers were planned to be built. The influencing factors of the different characteristics of elderly care service needs from three aspects were analyzed using a dichotomous logistic regression model: predisposing, enabling, and, need factors. Results: 69.7% of the elderly required home care services, 22.8% wanted to get care services at elderly care centers, 15.9% wanted to get care services at nursing homes, 12.3% required community care services, and 7.4% didn’t know where to access care services. 68.5% of the elderly required care services for disabilities/semi-disabilities, 58.0% for dementia, 54.7% for common diseases, 34.9% for rehabilitation training, 33.0% for plumbing care, and 7.5% for hospice care. At the same time, there were urban- rural differences in the demand for elderly care services, with suburban elderly having a higher demand for care services than those living in urban areas (P < 0.05). The elderly’s demand for care services was mainly related to age, place of residence, and gender in the causative factors, mode of residence and physical condition among able factors, and mode of care services and care needs among need factors (P < 0.05). Conclusion: The demand for elderly care services was differentiated by factors including place of residence, age, and gender. It is crucial to accurately match the demand for elderly care services, innovate the mode of elderly care services, and improve the service quality to improve the elderly health service system.

Anlotinib in combination with Envolizumab plus Etoposide for the treatment of EX-SCLC:a case report

Background:Small cell lung cancer(SCLC)is an aggressive malignant tumor with strong immunosuppressive effects,characterized by rapid doubling time and poor prognosis.Currently,effective therapeutic options are urgently needed for Extensive-stage small-cell lung Cancer.Case description:In the present case,a combination therapy of anlotinib,envolizumab,and etoposide was administered to treat an 80-year-old female patient with extensive-stage SCLC accompanied by mediastinal lymph node and bone metastasis.After two cycles of treatment,the tumor lesions in the right lungs decreased from 5.04*3.44 cm to 1.65*1.42 cm.As of now,no significant mass is seen there and no serious adverse reactions in this patient.Until September 2023,she has survived for 18 months with no disease progression.Conclusions:Research shows that Alectinib,in combination with evolocumab plus etoposide,could be an original,viable therapeutic option for the treatment option of patients with extensive-stage SCLC.

基于一流课程建设的分析化学实验教学改革与实践

分析化学是化学的四大基础课程之一,通常包含化学分析和仪器分析两门课程。我校自1983年建系以来即面向化学类专业开设了与理论课程向对应的分析化学(含仪器分析)实验课程。面向目前我校的化学和应用化学专业的学生,我们以精选教学内容、设计渐进式课程和采用多维度教学模式为主要改革方向,建设分析化学(含仪器分析)实验一流本科课程。

石墨烯的绿色制备、表征及典型应用综合型实验

石墨烯具有优异的光电性能,在“碳中和”相关技术领域有巨大的应用潜力。最近,我们开发了一种采用过硫酸钾为磨剂机械化学制备边缘羟基化石墨烯的绿色新方法,产物兼具石墨烯本征性能佳和水中分散性好的特点;制备过程不需要使用有机溶剂,能耗低,产生的废弃物量少且无毒。本文将该科研成果转化,设计了一个石墨烯的制备、表征及应用的综合型实验,利用多种仪器分析方法研究石墨烯的结构及光电性能,并与文献报道的研究结果进行了对比分析,不仅锻炼了学生综合运用知识解决实际问题的能力,而且有助于激发学生的创新思维,培养“绿色化学”意识。

基于微雨雷达的降水参数反演和粒子相态识别

本文基于微雨雷达原始的后向散射信号,采用一种新的功率谱处理算法(RaProM算法),在功率谱计算、噪声去除、退模糊等处理的基础上计算了雷达基本参量,并反演了液态降水参数,例如雷达反射率因子、雨强等,并对粒子相态进行识别。RaProM算法综合考虑粒子下落速度、等效雷达反射率因子、不同相态粒子的尺度特征以及是零度层亮带位置等信息,可识别的粒子相态包括雪、毛毛雨、雨、冰雹以及混合相态。选取了三个山东地区较为典型的个例对RaProM反演算法进行验证,即2021年7月2日典型层状云降水个例、2019年12月25日雨雪转换个例以及2018年3月4日零度层高度逐渐降低的降水个例。结果显示:粒子识别方法应用于典型层状云降水,垂直方向上不同相态粒子的分层较为明显,过冷层里的固态降水雪花、零度层附近冰水转换区的混合相态降水以及零度层以下的液态降水符合现有认识,验证了反演算法以及粒子识别算法的有效性。将结果进一步在雨雪转换降水相态识别中和零度层高度的检测,该反演算法均能得到较好应用,与同址同步观测的微波辐射计、云雷达、二维视频雨滴谱仪等观测结论一致。另外,与微雨雷达标准反演算法对比,RaProM算法的优势是没有粒子相态的原始假设,且考虑降水粒子向上的速度,反演结果与微波辐射计、云雷达在垂直结构上有较高的一致性。与地面激光雨滴谱仪观测数据对比显示,也有效提升了微雨雷达对雨滴谱和雨强的反演能力。

Neural stem cell-derived exosome as a nano-sized carrier for BDNF delivery to a rat model of ischemic stroke

Our previo us study demonstrated the potential therapeutic role of human neural stem cell-derived exosomes(hNSC-Exo)in ischemic stroke.Here,we loaded brain-derived neurotrophic factor(BDNF)into exosomes derived from NSCs to construct engineered exosomes(BDNF-hNSC-Exo)and compared their effects with those of hNSC-Exo on ischemic stroke both in vitro and in vivo.In a model of H_(2)O_(2)-induced oxidative stress in NSCs,BDNF-hNSC-Exo markedly enhanced cell survival.In a rat middle cerebral arte ry occlusion model,BDNF-hNSC-Exo not only inhibited the activation of microglia,but also promoted the differentiation of endogenous NSCs into neurons.These results suggest that BDNF can improve the function of NSC-derived exosomes in the treatment of ischemic stro ke.Our research may support the clinical use of other neurotrophic factors for central nervous system diseases.