湿热环境下复合材料含孔层合板静力拉伸性能及工程估算模型

湿热环境下的复合材料结构件力学性能预测对其工程应用具有重要意义。文中针对复合材料层合板静力拉伸性能和强度预测问题,开展6种湿热环境下复合材料含孔层合板的静力拉伸试验,分析其结构失效响应及损伤表征。基于应力场强法建立湿热环境下复合材料含孔层合板工程估算模型,与有限元渐进损伤模型和试验结果进行对比,分析了湿热环境对含孔层合板力学性能和拉伸失效的影响。结果表明,工程估算模型预测结果与有限元及试验结果误差范围较小,可用于预测温度和吸湿率对含孔层合板拉伸失效强度的影响;相比于室温干态,75℃吸湿饱和态下试件拉伸失效强度下降了6.1%;25℃干态和75℃吸湿饱和态下含孔层合板0°铺层出现最为严重的纤维拉伸失效,90°铺层出现最为严重的基体拉伸失效,纤维拉伸失效和基体拉伸失效为层合板主要破坏模式;通过扫描电镜对75℃吸湿饱和态下层合板厚度方向微观形貌进行分析,发现试件0°方向纤维与树脂的脱粘程度加重且出现明显的裂痕,90°方向纤维分布较为齐整,但黏附的树脂较少。

ChatGPT教育应用的优化路径

研究ChatGPT教育应用对通用人工智能时代下的教育数字化转型具有重要意义。通过系统测试和文献研究等方法,首先厘清ChatGPT的技术路线、应用场景和发展历程;然后从重塑教育的底层逻辑、催生学校结构变革和重构教育生态三个层面,论述ChatGPT给教育带来的机遇,并从技术局限性、伦理道德、知识产权、数据安全、知识异化等角度来论述其教育应用面临的挑战;最后提出ChatGPT教育应用的优化路径。一是加强自主研发,完善顶层设计。加强人工智能技术研发是掌握数字主权的必然要求,也是解决数据安全问题的关键。二是开发应用指南,引导应用方式。加快提升教育中各类主体的人工智能能力素养和伦理素养,遵循“伦理先行”意识,强化自律自治,共同打造良性发展的人工智能教育应用生态。三是认清技术本质,回归育人本位。只有辨明技术本质,回归到育人的本质,才能在技术与人的双向耦合中,培育出新的自由全面发展的个体。四是明确各方责任,加强情感互动。在开发者、教师、学校、学生等组成的教育生态系统中,要明确各主体的角色、责任与义务,重视对学生情感、态度、价值观的塑造,构建积极、健康且充满活力的教学环境。

Ultrathin organic polymer with p-πconjugated structure for simultaneous photocatalytic disulfide bond generation and CO_(2)reduction

Combining photocatalytic organic reactions with CO_(2)reduction is an efficient solar energy utilization mode,but it is still limited by the organic species that can be matched and the low conversion.Herein,ultrathin organic polymer with p-πconjugated structure(TPP)was rationally designed and prepared,and showed a high yield of CO(15.2 mmol g^(-1))and conversion of SAS coupled products(100%),far exceeding the organic polymer with P=O structure.The enhanced photoredox activity of TPP is ascribed to the orbital interaction between the p-orbital on phosphorus and theπ-orbitals of aromatic,which can accelerate the photoinduced charge carrier separation and improve the CO_(2)adsorption capacity.TPP can also be used for the dehydrocoupling of various benzyl mercaptans to the corresponding SAS bond products.This work provides a new concept for the efficient synthesis of disulfide bonds combined with CO_(2)reduction in a photoreaction system.

Sn-doped BiOCl nanosheet with synergistic H^(+)/Zn^(2+)co-insertion for“rocking chair”zinc-ion battery

The development of insertion-type anodes is the key to designing“rocking chair”zinc-ion batteries.However,there is rare report on high mass loading anode with high performances.Here,{001}-oriented Bi OCl nanosheets with Sn doping are proposed as a promising insertion-type anode.The designs of cross-linked CNTs conductive network,{001}-oriented nanosheet,and Sn doping significantly enhance ion/electron transport,proved via experimental tests and theoretical calculations(density of states and diffusion barrier).The H^(+)/Zn^(2+)synergistic co-insertion mechanism is proved via ex situ XRD,Raman,XPS,and SEM tests.Accordingly,this optimized electrode delivers a high reversible capacity of 194 m A h g^(-1)at 0.1 A g^(-1)with a voltage of≈0.37 V and an impressive cyclability with 128 m A h g^(-1)over 2500 cycles at 1 A g^(-1).It also shows satisfactory performances at an ultrahigh mass loading of 10 mg cm^(-2).Moreover,the Sn-Bi OCl//MnO_(2)full cell displays a reversible capacity of 85 m A h g^(-1)at 0.2 A g^(-1)during cyclic test.

Ataxia telangiectasia-mutated-Rad3-related DNA damage checkpoint signaling pathway triggered by hepatitis B virus infection

AIM： To explore whether acute cellular DNA damage response is induced upon hepatitis B virus （HBV） infection and the effects of the HBV infection. METHODS： We incubated HL7702 hepatocytes with HBV-positive serum, mimicking a natural HBV infection process. We used immunoblotting to evaluate protein expression levels in HBV-infected cells or in non-infected cells; immunofluorescence to show ATR foci ands Chkl phosphorylation foci formation; flow cytometry to analyze the cell cycle and apoptosis; ultraviolet （UV） radiation and ionizing radiation （IR）-treated cells to mimic DNA damage; and Trypan blue staining to count the viable cells. RESULTS： We found that HBV infection induced an increased steady state of ATR protein and increased phosphorylation of multiple downstream targets including Chkl, p53 and H2AX. In contrast to ATR and its target, the phosphorylated form of ATM at Ser-1981 and its downstream substrate Chk2 phosphorylation at Thr-68 did not visibly increase upon infection. However, the level of Mre11 and p21 were reduced beginning at 0.5 h aEer HBV-positive serum addition. Also, HBV infection led to transient cell cycle arrest in the S and the G2 phases without accompanying increasedapoptosis. Research on cell survival changes upon radiation following HBV infection showed that survival of UV-treated host cells was greatly increased by HBV infection, owing to the reduced apoptosis. Meanwhile, survival of IR-treated host cells was reduced by HBV infection. CONCLUSION： HBV infection activates ATR DNA damage response to replication stress and abrogates the checkpoint signaling controlled by DNA damage response.

Primary cilia in corneal development and disease

As a transparent avascular tissue located at the front of the eyeball, the cornea is an important barrier to external damage. Both epithelial and endothelial cells of the cornea harbor primary cilia, which sense changes in the external environment and regulate intracellular signaling pathways. Accumulating evidence suggests that the primary cilium regulates corneal development in several ways, including participation in corneal epithelial stratification and maintenance of corneal endothelial cell morphology.In addition, the primary cilium has been implicated in the pathogenesis of several corneal diseases. In this review, we discuss recent findings that demonstrate the critical role of the primary cilium in corneal development. We also discuss the link between ciliary dysfunction and corneal diseases, which suggests that the primary cilium could be targeted to treat these diseases.

沥青路面就地热再生技术在武黄高速公路养护工程中的应用与反思

为减少公路沥青路面养护工作中沥青废料的产生,循环利用沥青路面材料,武黄高速公路使用沥青就地热再生技术对路面进行了养护。经过5年的观测,试验路段总体情况良好,不足之处可通过优化方案设计、控制施工质量进行解决。

Model-free Adaptive Control for Spacecraft Attitude

A model-free adaptive control method is proposed for the spacecrafts whose dynamical parameters change over time and cannot be acquired accurately. The algorithm is based on full form dynamic linearization.A dimension reduction matrix is introduced to construct an augmented system with the same dimension input and output. The design of the controller depends on the system input and output data rather than the knowledge of the controlled plant. The numerical simulation results show that the improved controller can deal with different models with the same set of controller parameters,and the controller performance is better than that of PD controller for the time-varying system with disturbance.

玄武岩纤维改性沥青胶浆流变性能研究

玄武岩纤维与沥青、矿粉共同构成沥青胶浆,胶浆的性能能够直接影响沥青混凝土材料的性能。因此,研究分析玄武岩纤维对纤维沥青胶浆性能的作用效果十分必要。为了考察玄武岩纤维、沥青材料之间的相互作用机理,分别采用动态剪切流变试验、低温弯曲流变试验来评价不同玄武岩纤维掺量的沥青胶浆高、低温性能,研究结果认为,玄武岩纤维增强了沥青混合料的整体性,对沥青胶浆的总体性能有较好的改善作用。本文研究结果可为沥青路面工程中玄武岩纤维沥青胶浆性能相关研究工作提供技术支撑。

What＇s Wrong with the Chinese Cyber Market？ -A Discussion on Trust

Given the booming of internet usage in its domain, Chinese on-line shopping business is not growing proportionately. The absence of a market mechanism based on trust among suppliers and customers is to blame, although other factors as well holding the responsibility. Beginning with an introduction to the theory of ＂lemons＂, this paper reviews the status quo of trust in the Chinese cyber market, from the perspective of legislation, regulation and institution. It also prescribes several possible micro-solutions.

rADSC-loaded tubular units composed of multilayer electrospun membranes promoted bone regeneration of critical-sized skull defects

Adipose-derived stem cells(ADSCs)have considerable potential for bone regeneration.However,their performance is limited by a lack of scaffolds that adequately mimic the hierarchical structure of bone to promote proliferation and osteogenic differentiation of ADSCs.In this study,nanofiber membranes composed of polycaprolactone,poly(lactide-co-glycolide),and hydroxyapatite(HAp)were prepared via electrospinning,and the membranes curled after responding to temperature stimuli in an aqueous solution.Transmission electron microscopy and scanning electron microscopy observations indicated that needle-like HAp nanoparticles with an average diameter of 57±39 nm and a length–diameter ratio of 7.4±1.56 were entrapped in the nanofiber matrix and did not affect the surface morphology of fibers.After cutting and deformation,the nanofibers changed from straight to bent,and the diameters increased;they were 1105±200 nm for BPLG85-H and 1120±199 nm for BPLG80-H.Additionally,tubular units with a single layer(BPLG-H(1.5))or multiple layers(BPLG-H(3.5))were obtained by controlling the initial shape and size of the membranes.rADSCs on the concave surface of BPLG-H(3.5)proliferated faster and exhibited better osteogenic activity than those on the convex side of BPLG-H(3.5)and both surfaces of BPLG-H(1.5),which was correlated with the higher expressions of vascular endothelial growth factor and bone morphogenetic protein 2.Additionally,rADSCs on both units maintained osteogenic activity after storage at-80◦C for 20 d.In rat skull defect(diameter of 8 mm)models,rADSC-loaded BPLG-H(3.5)units fixed using gelatin hydrogel(ADSC@BHM)exhibited 84.1±6.6%BV/TV after implantation for 12 weeks,which was 155.6%higher than that of the Blank group.H&E and Masson’s staining results demonstrated that there was more bone regeneration at the defect center of ADSC@BHM than in the BHM and Blank groups.In conclusion,rADSC-loaded BPLG-H(3.5)with an osteon-mimic structure provides a potential strategy to repair bone defects.

Hepatitis C Virus Infection Downregulates the Ligands of the Activating Receptor NKG2D

Natural killer （NK） cells are a major component of the host innate immune defense against various pathogens. Several viruses, including hepatitis C virus （HCV）, have developed strategies to evade the NK-cell response. In our study, we found HCV infection could trigger DNA damage response by both ataxia telangiectasia mutated （ATM） and ATM- and Rad3-related （ATR） pathways. Recent reports had revealed that NKG2D ligands （NK cell- activating ligands） were upregulated when a major DNA damage checkpoint pathway was activated. However, here we found that DNA damage response was activated but NKG2D ligands were downregulated upon HCV infection. Further studies showed that the protease NS3/4A of HCV which had been shown relation with immune invasion contributed to the reduced expression of NKG2D ligands. These findings provide a novel insight into the mechanisms evolved by HCV to escape from the NK cell response. Cellular ＆ Molecular Immunology. 2008;5（6）： 475-478.

The tumor suppressor CYLD controls epithelial morphogenesis and homeostasis by regulating mitotic spindle behavior and adherens junction assembly

Epithelial morphogenesis and homeostasis are essential for animal development and tissue regeneration, and epithelial disorganization is associated with developmental disorders and tumorigenesis. However, the molecular mechanisms that contribute to the morphogenesis and homeostasis of the epithelium remain elusive. Herein, we report a novel role for the cylindromatosis （CYLD） tumor suppressor in these events. Our results show that CYLD depletion disrupts epithelial organization in both Drosophila egg chambers and mouse skin and intestinal epithelia. Microscopic analysis of proliferating cells in mouse epithelial tissues and cultured organoids reveals that loss of CYLD synergizes with tumor-promoting agents to cause the misorientation of the mitotic spindle. Mechanistic studies show that CYLD accu- mulates at the cell cortex in epithelial tissues and cultured ceils, where it promotes the formation of epithelial adherens junctions through the modulation of microtuhule dynamics. These data suggest that CYLD controls epithelial morphogenesis and homeostasis by modulating the assembly of adherens junctions and ensuring proper orientation of the mitotic spindle. Our findings thus provide novel insight into the role of CYLD in development, tissue homeostasis, and tumorigenesis.

离子液体电沉积

离子液体具有电化学窗口宽,热稳定性良好和结构性能可调等独特的物理化学性质,是一种有着广阔应用前景的电沉积介质.本文介绍了离子液体电沉积的发展历程、典型的离子液体电沉积体系结构组成及其中的重要科学问题,并综述了近15年来离子液体电沉积的研究进展.本文详细介绍了五种不同类型离子液体中金属/合金的电沉积过程,包括卤素金属酸盐型离子液体、空气和水稳定型离子液体、低共熔溶剂、含金属阳离子型离子液体和质子型离子液体,并且系统概述了调节因素如沉积条件(电流密度、沉积模式、沉积时间、温度)和电解质成分(阴离子、阳离子、金属盐、添加剂、水分)对于沉积物形貌、组成、微观结构和性质的影响规律.之后,重点介绍了离子液体在半导体电沉积中的研究进展.最后,指出了目前离子液体电沉积在基础理论和技术研究中面临的挑战,并展望了其未来在电子信息领域的发展前景.

Corrigendum to “Remodeling tumor immunosuppressive microenvironment via a novel bioactive nanovaccines potentiates the efficacy of cancer immunotherapy” [Bioactive Mater. 16 107-119]

The authors regret that the published version of the above article contained two errors which were not identified during the proofing stage.Also,Figure 2A and 6C have been replaced.The authors apologize for these errors and state that these corrections do not change the scientific conclusions of the article in any way.

Triassic integrative stratigraphy and timescale of China

The Triassic rocks are widespread in China, and both marine and terrestrial strata are well developed. The Triassic stratigraphic architecture of China is very complex in both spatial variation of the so-called "South Marine and North Continental", i.e. the southern areas of China occupied mostly by marine facies while the northern China by terrestrial facies during the Triassic Period, and temporal transition of the "Lower Marine and Upper Continental", i.e. the lower part of the Triassic System composed mainly of marine facies and the upper part of terrestrial strata especially in South China. Although the Global Stratotype Section and Point(GSSP) of the Permian-Triassic boundary is located in South China, the Triassic of China except for some marine Lower-Middle Triassic depositions shows significantly local characteristics and is hardly correlated with the global chronostratigraphic chart. Consequently, the Triassic of China contains not only the international research hotspots but also difficult points in stratigraphic study. This paper aims to present a brief review of the Triassic in China, including chronostratigraphy, biostratigraphy, magnetostratigraphy and chemostratigraphy, and summarize an integrated Triassic stratigraphic framework of China. Accordingly, a stratigraphic correlation is proposed for the lithostratigraphic sequences among the three tectono-paleogeographic stratigraphic regions. The comprehensive study indicates that ammonoids are the classic index fossils in Triassic biostratigraphy but conodonts are more advantageous in the study and definition of the Triassic chronostratigraphic boundaries. China still has the potential to optimize the GSSPs of the Induan-Olenekian boundary and Olenekian-Anisian boundary. The correlation of the Permian-Triassic boundary between marine and terrestrial facies might be achieved with the help of the Permian-Triassic "transitional bed" and its related biotic and environmental events in association with the biostratigraphic study of conchostracan, vertebrate and plant fossils. In addition, the carbon isotopes have been proved to be one of the powerful methods in marine Triassic stratigraphic study, whereas the oxygen and strontium isotopes may be additional important bridges to establish the correlation between the marine and terrestrial strata, but as yet lacking of relevant studies in terrestrial strata. Considering the most stratigraphic intervals of the Triassic and the terrestrial Triassic in China are difficult to be correlated to the global chart, the proposed Chinese(regional) Triassic chronostratigraphic chart of marine and terrestrial stages would be of importance to the study of Chinese Triassic stratigraphy and related aspects, but the stages must be conceptually in line with international standards and studied as soon as possible in order to finalize the definition.

Influence of the source’s energy fluctuation on computational ghost imaging and effective correction approaches

We investigate the influence of the source’s energy fluctuation on both computational ghost imaging and computational ghost imaging via sparsity constraint,and if the reconstruction quality will decrease with the increase of the source’s energy fluctuation.In order to overcome the problem of image degradation,a correction approach against the source’s energy fluctuation is proposed by recording the source’s fluctuation with a monitor before modulation and correcting the echo signal or the intensity of computed reference light field with the data recorded by the monitor.Both the numerical simulation and experimental results demonstrate that computational ghost imaging via sparsity constraint can be enhanced by correcting the echo signal or the intensity of computed reference light field,while only correcting the echo signal is valid for computational ghost imaging.

Remodeling tumor immunosuppressive microenvironment via a novel bioactive nanovaccines potentiates the efficacy of cancer immunotherapy

The clinical outcomes of cancer nanovaccine have been largely impeded owing to the low antigen-specific T cell response rate and acquired resistance caused by the immunosuppressive tumor microenvironment(TME).Here,we reported a tumor acidity-responsive nanovaccine to remodel the immunosuppressive TME and expand the recruitment of tumor infiltrating lymphocytes(TILs)using hybrid micelles(HM),which encapsulated colony stimulating factor 1 receptor(CSF1-R)inhibitor BLZ-945 and indoleamine 2,3-dioxygenase(IDO)inhibitor NLG-919 in its core and displayed a model antigen ovalbumin(OVA)on its surface(denoted as BN@HM-OVA).The bioactive nanovaccine is coated with a polyethylene glycol(PEG)shell for extending nanoparticle circulation.The shell can be shed in response to the weakly acidic tumor microenvironment.The decrease in size and the increase in positive charge may cause the deep tumor penetration of drugs.We demonstrated that the bioactive nanovaccine dramatically enhance antigen presentation by dendritic cells(DCs)and drugs transportation into M1-like tumor-associated macrophages(TAMs)and tumor cells via size reduction and increasing positive charge caused by the weakly acidic TME.Such bioactive nanovaccine could remodel the immunosuppressive TME into an effector T cells favorable environment,leading to tumor growth inhibition in prophylactic and therapeutic E.G7-OVA tumor models.Furthermore,combining the bioactive nanovaccine with simultaneous anti-PD-1 antibody treatment leads to a long-term tumor inhibition,based on the optimal timing and sequence of PD-1 blockade against T cell receptor.This research provides a new strategy for the development of efficient cancer immunotherapy.

Precision Surgery for Placenta Previa Complicated with Placenta Percreta

Objectives:To investigate whether a precise circular resection of the uterine tissue at the placental attachment part is effective in cases with placenta previa complicated with placenta percreta (PPWPP).Methods:Patients diagnosed with PPWPP were assessed for pregnancy termination at 34-36 weeks of gestation.During the operation,we performed circular resection of the uterine tissue at the placental attachment part.Then the characteristics of the operation and the follow-ups were recorded.Results:During the operation,the vital signs were stable.The mean intraoperative blood loss,packed red blood cells units transfusion,fresh frozen plasma transfusion,and operation time were 2140 mL,6 U,440 mL,and 179.8 minutes,respectively.There was no bowel,ureter,or bladder injury.And there was no patient transferred to the ICU after operation.The mean postoperative blood loss was 458.6mL.There was no fever,infection,intestinal obstruction,or other complications after operation during the hospitalization.The shape and the blood flow of the uterus were normal.After the patients were discharged,one had developed cesarean scar diverticulum.The mean lochia duration was 30 days.The menstrual cycle and volume were as before.The shape and the blood flow of the uterus and the ovarian were normal.Conclusions:The circular resection following end-to-end anastomosis is an effective precision surgical approach for PPWPP.It can achieve the purpose of hemostasis while maximizing the protection of organ function and reducing surgical trauma.

Systems analysis of the“weights”of Bcl-2 and Mcl-1 in mitochondrial apoptosis pathway establishes a predictor for best drug combination ratio

Background:Inhibitors of B-cell CLL/Iymphoma 2(Bcl-2)family proteins have shown hope as antitumor drugs.While the notion that it is efficient to coordinate,balance,and neutralize both arms of the anti-apoptotic Bcl-2 family has been validated in many cancer cells,the weights of the two arms contributing to apoptosis inhibition have not been explored.This study analyzed the best combination ratio for different Bcl-2 selective inhibitors.Methods:We used a previously established mathematical model to study the weights of Bcl-2(representing both Bcl-2 and BcI-xL in this study)and myeloid cell leukemia-1(Mcl-1).Correlation and single-parameter sensitivity analysis were used to find the major molecular determinants for Bcl-2 and Mcl-1 dependency,as well as their weights.Biological experiments were used to verify the mathematical model.Results:Bcl-2 protein level and Mcl-1 protein level,production,and degradation rates were the major molecular determinants for Bcl-2 and Mcl-1 dependency.The model gained agreement with the experimental assays for ABT-737/A-1210477 and ABT-737/compound 5 combination effect in MCF-7 and MDA-MB-231.Two sets of equations composed of Bcl-2 and Mcl-1 levels were obtained to predict the best combination ratio for Bcl-2 inhibitors with Mcl-1 inhibitors that stabilize and downregulate Mcl-1,respectively.Conclusions:The two sets of equations can be used as tools to bypass time-consuming and laborious experimental screening to predict the best drug combination ratio for treatment.