Research Hotspot and Application Status of Immune Evasion Mechanism in Ovarian Cancer

Ovarian cancer is one of the three major malignant tumors in gynecology, with increasing incidence and mortality rates. Currently, the main treatment methods remain surgical intervention in combination with chemotherapy. However, due to its high recurrence rate and the risk of drug resistance, the overall prognosis is poor. Ovarian cancer has been identified as an immunegenic tumor, and in recent years, with the continued advancement of research into immune evasion mechanisms, immunotherapy has emerged as a groundbreaking treatment modality. This article will focus on the immune escape mechanisms and their application in ovarian cancer, providing a comprehensive overview of its current status and the challenges it faces.

Simulation on function mechanism of T1(Al_2CuLi) precipitate in localized corrosion of Al-Cu-Li alloys

To clarify the corrosion mechanism associated with the precipitate of T1(Al2CuLi)in Al-Li alloys,the simulated bulk precipitate of T1 was fabricated through melting and casting.Its electrochemical behavior and coupling behavior with α(Al)in 3.5% NaCl solution were investigated.Meanwhile,the simulated Al alloy containing T1 particle was prepared and its corrosion morphology was observed.The results show that there exists a dynamic conversion corrosion mechanism associated with the precipitate of T1.At the beginning,the precipitate of T1 is anodic to the alloy base and corrosion occurs on its surface.However,during its corrosion process,its potential moves to a positive direction with immersion time increasing,due to the preferential dissolution of Li and the enrichment of Cu.As a result,the corroded T1 becomes cathodic to the alloy base at a later stage,leading to the anodic dissolution and corrosion of the alloy base at its adjacent periphery.It is suggested that the localized corrosion associated with the precipitate of T1 in Al-Li alloys is caused by the alternate anodic dissolution of the T1 precipitate and the alloy base at its adjacent periphery.

Effect of Tumor Necrosis Factor-αon Resistin Expression in 3T3-L1 Adipocytes and Its Mechanism

Summary: In order to investigate the effect of tumor necrosis factor-α (TNFα) on resistin expression in 3T3-L1 adipocytes, and further explore its mechanisms, the differentiated 3T3-L1 adipocytes were incubated with 0, 1, 10, 100 ng/mL TNFα respectively for 24 h, and then the expression of resistin was determined. The differentiated 3T3-L1 adipocytes were incubated with 100 ng/mL TNFα for 3, 6, 24 h respectively, and then the expression of resistin mRNA was analyzed. 3T3-L1 adipocytes were induced to differentiate into mature adipocytes. The cells were randomly divided into 4 groups for culture. In the control group, no drugs were added. Cells of TNFα group were treated with 100 ng/mL TNFα. In Ro-31-8220 group, 5 μmol/L protein kinase C inhibitor Ro-31-8220 was added. With TNFα+Ro-31-8220 group, 100 ng/mL TNFα were added 1 h after the addition of 5 μmol/L Ro-31-8220. All adipocytes were cultured for 24 h. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were employed to detect the expression of resistin gene. Our results showed that resistin protein and mRNA in 3T3-L1 adipocytes were inhibited by TNFα at different concentrations (P<0.01), and the inhibitory effect increased with the concentration (P<0.01). At the same concentrations, the inhibitory effect increased with time (P<0.01). Ro-31-8220 could inhibit its expression and the inhibitive effect remained unchanged with addition of TNFα(P>0.05). It was concluded that TNFα could inhibit the expression of resistin in 3T3-L1 adipocytes. The mechanism may be that the expression of resistin is partly controlled by protein kinase C signal conduction pathway.

Microstructures and mechanical properties of as-extruded and heat treated Mg-6Zn-1Mn-4Sn-1.5Nd alloy

The microstructures and mechanical properties of Mg-6Zn-1Mn-4Sn-1.5Nd alloy subjected to extrusion and T5 treatment were investigated using optical microscopy（OM）, X-ray diffractometer（XRD）, scanning electron microscopy（SEM）, electron back scattered diffraction（EBSD）, transmission electron microscopy（TEM）, hardness tests and uniaxial tensile tests. The results showed that the as-cast alloy consisted of α（Mg）, Mn, Mg7Zn3, Mg2 Sn and Mg Sn Nd phases. Dynamic recrystallization has completed during the extrusion process and the average grain size was 7.2 μm. After T5 treatment, the strength increased obviously, the yield strength and ultimate tensile strength of as-extruded alloy were increased by 94 and 34 MPa, respectively. Microstructure characterization revealed that the improvement of strength was determined by the high number density of β′1 rods.

Optimum Seeking of Redundant Actuators for M-RCM 3-UPU Parallel Mechanism

The singularity problem brings troubles to the design and application for the parallel mechanism.Currently,redun-dant actuation is one of the useful methods to solve this singularity problem.However,faced to the numerous joints in a parallel mechanism,how to make a quantitative criterion of seeking the most efficient joints added actuators for letting the mechanism passes through singularity is a necessarily open issue.This paper focuses on a 2R1T 3-UPU(U for universal joint and P for prismatic joint)parallel mechanism(PM)with two rotational and one translational(2R1T)degrees of freedom(DOFs)and the ability of multiple remote centers of motion(M-RCM).The singularity analysis based on the indexes of motion/force transmissibility and constraint shows that this PM has transmission singular-ity,constraint singularity,mixed singularity and limb singularity.To solve these singular problems,the quantifiable redundancy transmission index(RTI)and the redundancy constraint index(RCI)are proposed for optimum seeking of redundant actuators for this PM.Then the appropriate redundant actuators are selected and the working scheme for redundant actuators near the corresponding singular configuration are given to help the PM passes through the singularity.This research proposes a quantitative criterion to optimum seeking of redundant actuators for the parallel mechanism to solve its singularity.

中国ETF期权Delta对冲收益的日夜特征研究

期权市场是现代金融市场的重要组成部分,研究期权市场Delta对冲收益的日夜特征,对于理解期权市场运行机制以及降低金融市场风险具有重要意义.本文使用我国2015年—2021年股票ETF期权数据,研究了期权Delta对冲收益的日夜特征.研究结果表明,总体上Delta对冲的隔夜收益为负、日内收益不显著;认购期权和认沽期权的Delta对冲收益具有非对称性,即认购期权日内为负、隔夜为正,而认沽期权恰好相反.即使替换为基于波动率和标的资产价格关系的对冲模型,非对称性异象仍然存在.这些发现不同于美国期权市场的Delta对冲收益日内为正、隔夜为负的特征.本文进一步探讨了可能的成因:从风险溢价看,波动率风险溢价可以解释总体上负的隔夜对冲收益,但是不能解释Delta对冲收益的非对称性;从模型误差看,模型误差与标的资产收益共同作用影响了Delta对冲收益;从交易制度看,T+1交易制度约束造成了标的资产日夜收益反转,进而导致了对冲收益的非对称性,并且T+1交易制度约束越强,对冲收益的非对称性越明显.本文将丰富我国期权市场Delta对冲效率、交易制度对金融市场影响的相关研究,有利于提高投资者的风险管理水平、增进监管者对市场行为的理解,从而推动中国多层次资本市场的高质量发展.

Theoretical Studies on the Mechanism of Photocycloaddition Reaction Between 6 Azauracil and Acetone

The mechanism of photocycloaddition reaction between 6-azauracll and acetone was studied by using semiemptrical SCFMO AMI method. It was found that this reaction is not a concerted one. The calculated results are as follows:(1) A T1 state exciplex is on the T1 state energy surface; (2) T exciplex as a reactant will proceed along the energy surface of T1 state to form a diradical intermediate. The energy barrier of this reaction step is 63. 6 kJ/mol; (3) The T1 state diradical intermediate happens to be close in energy to the ground state intermediate with a similar geometry. Such a situation turns out to be very favorable for an intersystem crossing (jump from the T, state to the ground state) ; (4) The final product will be formed from the ground S0 state intermediate via an energy barrier 88. 2 kJ/mol.

Pannonibacter phragmitetus T1菌对Pb^(2+)的吸附特性

以pannonibacter phragmitetus T1菌作为生物吸附剂,研究细菌代谢活性、培养时间、溶液pH值、菌体用量、温度、吸附时间、初始金属浓度等因素对其吸附重金属Pb2+的影响,并进一步研究吸附机理。结果表明,培养12 h的灭活T1菌体在Pb2+浓度为150 mg/L、pH值为6、T1菌添加量为0.5 g/L、温度为30℃的条件下,对Pb2+的最大吸附量为68.35 mg/g;灭活T1菌对重金属Pb2+的吸附过程较快,90 min即达到吸附平衡,Pb2+的吸附符合Pseudo-second order模型和Langmuir等温吸附模型。结合红外光谱分析,灭活pannonibacter phragmitetus T1菌对Pb2+是表面吸附,羟基和酰胺基是与Pb2+络合反应的主要基团。

“T+1”交易制度下非线性证券价格动态模型及实证

考虑我国证券市场的"T+1"交易制度,构建了二维离散非线性证券价格动态模型,分析了模型中买卖者之间的异质转换速度、均值回归战略及传染效应对证券价格动态稳定性的影响,实证检验了我国证券市场的这3个主要因素.结果表明,买卖者之间的异质转化速度导致了均衡价格对于价值的偏离,并且随着传染效应的不断增大,价格呈现出复杂的运动轨迹而难以稳定.实证显示,中国投资者买卖观点转换概率只具有传染效应的价格发散机制而不具有均值回归的价格稳定机制,这是现阶段中国证券市场价格难以通过市场的自我调节达到价值的基本原因.

“T+0”和“T+1”制度下投资者交易风险对比

从投资者当日(T)投资所面临的交易风险出发,运用数据客观地对比分析了在“T+0”和“T +1”两种交易制度下带给投资者的交易风险,阐明在保护投资者利益方面两种交易制度的优劣性,通过数据分析,认为“T+1”交易制度并不能更好地保护下跌行情中从事股票交易的投资者利益．甚至,在上海证券市场上“T+1”交易制度下的交易令投资者不能及时纠正交易错误,导致投资者的交易风险有扩大趋势．其实,投资者面临的最大交易风险并不是“T+0”和“T+1”这两种交易制度所带来的,而是股票市场的下跌造成的．因此,如果综合考虑我国股票市场的未来发展以及两种交易制度带给投资者的交易风险,实施“T+0”交易制度是可行的．

试析中国证券市场T+1交易制度改革

中国证券市场曾经实行过T+0交易制度,由于存在过度投机T+0被取消,进而推出了T+1交易制度。2010年之后,股指期货等金融衍生产品的推出标志着中国证券改革正走向纵深,T+1交易制度已经不再适应中国资本市场的重大变化,特别是光大"8·16"乌龙事件中,机构利用股指期货和ETF变相T+0交易规避风险,市场的公平与效率亟待维护和提升。为此,本文提出在沪深300成分股中率先实行T+0制度的渐次改革原则及其三大理由。

T+1交易制度对中国股票市场的影响——来自长期折价率的证据

T+1交易制度通过影响投资者交易意愿、约束投资者交易行为影响证券资产的价格形成。文章分析了T+1交易制度对开盘时刻股票供需关系的影响,并利用双边界随机前沿模型从交易剩余的角度度量了T+1交易制度导致的长期折价率。研究发现:受T+1交易制度的影响,开盘时刻股票买方的议价能力高达60.03%,而卖方的议价能力仅为39.97%;T+1交易制度产生了较高的制度成本,平均每年导致隔夜收益折价11.91%,是促成负隔夜收益的制度性原因。本研究丰富和发展了对T+1交易制度的理论认识,对进一步完善中国股市交易制度(实施T+0)、提升市场定价效率等有重要启示。

CHK21100delC, I157T, IVS2 +IG >A, BRCA1 and BRCA2 Mutation Analysis in JF305: A Pancreatic Cancer Cell Line

JF305 is a highly prolific pancreatic cancer cell line that originated from a Chinese patient. The cell line bears a functional HR double strand DNA repair mechanism but very responsive to PARP treatment a phenomenon clearly suggesting presence of an anomaly in the mechanism. Brca1, Brca2 and CHK2 proteins are very important constituents of the HR mechanism whose respective gene coding mutations are strongly associated with several cancers and are widely exploited in anticancer chemotherapy. In this current study, the BRCA1, BRCA2 gene mutation status in JF305 was determined together with the presence of 3 widely reported cancer linked CHK2 founder mutations (1100delC, I157T, IVS2 +IG > A). CHK21100delC genotype was determined using allele specific PCR, while the PCR-RFLP assay was used for I157T, IVS2 +IG > A analysis. PCR and direct sequencing were used for assessing the BRCA1 and BRCA2 gene. Results revealed that JF305 is CHK21100delC heterozygous mutant, CHK2I157T and CHK2IVS2 +IG > A wild type. Furthermore, it was observed that JF305 lacked BRCA1 and BRCA2 gene mutations. The mutation status identification of CHK2 and BRCA1/2 in JF305 provides a major milestone towards elucidating the properties of the cell line which subsequently promises to be an excellent model for evaluating the role of parp inhibitors in pancreatic cancer chemotherapy most especially in the respective cancer cell lines without BRCA1 and BRCA2 gene mutations.

地黄饮通过调控JAK1/STAT3信号通路治疗特应性皮炎小鼠的作用机制

目的:探讨地黄饮对2,4-二硝基氯苯(DNCB)诱导的特应性皮炎(AD)模型小鼠的作用及潜在机制。方法:通过DNCB反复刺激小鼠背部皮肤建立小鼠AD模型,造模成功后,随机分为模型组、润燥组(0.78 g·kg^(-1))、地黄饮高、中、低剂量组(40.30、20.15、10.08 g·kg^(-1)),每组12只,空白组12只,共72只。给药组按剂量灌胃给予相应药液,空白组和模型组灌胃给予同体积纯净水,1次/d,连续给药2周后观察小鼠皮损及搔抓次数;取小鼠背部皮损进行苏木素-伊红(HE)染色和甲苯胺蓝染色观察病理情况;酶联免疫吸附测定法(ELISA)检测小鼠血清免疫球蛋白E(IgE)、白细胞介素-4(IL-4)、白细胞介素-6(IL-6)、干扰素-γ(IFN-γ)含量;实时荧光定量聚合酶链式反应(Real-time-PCR)检测皮损组织中IFN-γ、IL-4、IL-6、Janus激酶1(JAK1)、转录激活因子3(STAT3)mRNA的表达水平;蛋白免疫印迹法(Western blot)检测皮损组织JAK1、磷酸化(p)-JAK1、STAT3、p-STAT3蛋白的表达。结果:与空白组比较,模型组小鼠背部皮肤可见大量结痂、干燥、糜烂、肥厚伴搔抓,皮损组织可见表皮增生,伴角化过度和角化不全,棘层肥厚伴水肿,真皮层可见大量肥大细胞浸润,部分处于脱颗粒状态,小鼠血清中IgE、IL-4、IL-6、IFN-γ含量显著升高(P<0.01),皮损组织中p-JAK1、STAT3、p-STAT3蛋白表达水平及IL-4、IL-6、IFN-γ、JAK1、STAT3 mRNA表达显著升高(P<0.01);与模型组比较,各给药组小鼠背部皮肤仅见少量干燥、脱屑,细胞水肿减轻,炎性浸润明显减轻,肥大细胞浸润数明显降低,小鼠血清中IgE、IL-4、IL-6、IFN-γ均有不同程度降低(P<0.05,P<0.01),皮损组织中p-JAK1、STAT3、p-STAT3蛋白表达水平及IL-4、IL-6、IFN-γ、JAK1、STAT3 mRNA表达明显降低,其中以地黄饮高剂量组效果最佳(P<0.01)。结论:地黄饮能改善AD小鼠的皮损及瘙痒症状,其作用机制可能与干预JAK1/STAT3信号通路有效调节辅助性T细胞(Th)1/Th2轴上的细胞因子,影响皮肤屏障功能有关。

中国股市T+1交易制度会增加日内波动吗?——基于隔夜日内反转视角的分析

T+1交易制度限制卖出权利造成股票折价。本文利用期权分解出T+1折价对收益率的边际影响,指出其引致隔夜日内反转的补偿效应,进而使得日内波动加剧。T+1折价越大,补偿效应越强,日内波动越大。利用高频数据的实证分析结果表明,T+1交易制度会引发补偿效应、造成日内波动增加,T+1折价越大日内波动越大,且在牛熊市下、控制隔夜新闻和投资者情绪后依然稳健;在卖空约束更强、异质信念更强、振幅更大时,上述关系更显著。

中国-中东欧国家林产品贸易影响因素PEST分析

自2012年4月中国-中东欧国家合作机制(简称“17+1合作机制”)建立以来,中国与中东欧17国经贸往来发展迅速,林产品贸易量也不断增长。本文首先总结了中东欧17国森林资源禀赋与林业产业,梳理了中国与中东欧17国林业贸易发展的历程。在此基础上采用PEST方法对影响中国-中东欧17国林产品贸易的外部环境因素进行分析,并提出进一步推动中国-中东欧国家林产品贸易发展的建议。

T+0交易制度的计算实验研究

利用计算实验方法考察T+0交易制度对市场质量的影响.实验结果表明,无论是在正常还是异常波动的市场中,相对于T+1,T+0制度降低了日内波动性、增加了日内流动性和定价效率,因而改善了市场质量.这是由于在T+1制度下,投资者买入股票后,如果当天的市场价格发生较大波动或其预测价格发生了变化,投资者无法进行日内卖出,只能把需要当天卖出的订单累积到下一天早盘集中卖出,从而导致市场价格发生大的波动,如果由此又触发其他投资者的止损点,会导致市场进一步下跌并加大市场波动.T+0制度则避免了上述问题,使得基本价值波动能够在日内消化,同时活跃的日内交易又改善了流动性,从而提高了市场质量.

套利限制对股票错误定价的影响研究

本文从形成套利限制的基础要素出发,将套利限制划分为交易成本、交易风险和交易约束,研究了不同维度套利限制对股票错误定价的影响。结果显示:在对错误定价具有正向影响的各细分维度套利限制中,交易约束起主导作用;股价高估情形下,交易约束对错误定价的影响起主导作用,交易成本则具有负向影响;低估情形下,交易成本起主导作用,各细分维度套利限制与错误定价的相关关系与高估情形相反,呈现显著的非对称关系;各细分维度套利限制通过改变投资者买卖行为导致了这一现象。本文首次探究了不同维度套利限制对错误定价的影响,并将T+1交易制度引发的套利限制纳入研究范围,为套利活动和我国资本市场基础制度改革提供相关建议。

“T+1”交易制度和中国权证市场溢价

本文中,我们探讨了中国股票市场上一项独特的交易限制:"T+1"交易制度。这一制度要求股票购买者至少到第二天才能将股票卖出。而中国的权证市场则服从"T+0"的交易制度,即购买者可以随时将权证卖出。我们证明"T+1"制度会降低股票市场流动性,使股票的价格中存在低流动性折价。我们还证明股票流动性和相应权证的溢价之间存在着负相关的关系。最后,基于文中的实证结果,我们给出了一些政策上的建议。

T+1交易制度下的资产定价模型研究——基于隔夜收益率视角

本文通过对T+1交易制度下交易行为的理论分析以及对A股市场收益的实证检验,发现隔夜收益率与T+1交易制度之间有着密切的联系。在T+1交易制度下,中国沪深A股市场整体隔夜收益率为负的现象十分稳定、显著,并且低隔夜收益率的股票在未来往往会带来更高的收益;在FamaFrench三因子模型基础上,建立的由市场投资组合、规模因子和隔夜收益率因子组成的三因子模型对于中国A股市场收益的解释力更优。