Endoscopic diagnosis and treatment of superficial nonampullary duodenal tumors

The diagnostic and treatment guidelines of superficial non-ampullary duodenal tumors have not been standardized due to their low prevalence.Previous reports suggested that a superficial adenocarcinoma(SAC) should be treated via local resection because of its low risk of lymph node metastasis,whereas a highgrade adenoma(HGA) should be resected because of its high risk of progression to adenocarcinoma.Therefore,pretreatment diagnosis of SAC or HGA is important to determine the appropriate treatment strategy.There are certain endoscopic features known to be associated with SAC or HGA,and current practice prioritizes the endoscopic and biopsy diagnosis of these conditions.Surgical treatment of these duodenal lesions is often related to high risk of morbidity,and therefore endoscopic resection has become increasingly common in recent years.Endoscopic mucosal resection(EMR) and endoscopic submucosal dissection(ESD) are the commonly performed endoscopic resection methods.EMR is preferred due to its lower risk of adverse events;however,it has a higher risk of recurrence than ESD.Recently,a new and safer endoscopic procedure that reduces adverse events from EMR or ESD has been reported.

Optimal Design of Multiple Stress Constant Accelerated Life Test Plan on Non-rectangle Test Region

For optimal design of constant stress accelerated life test（CSALT） with two-stress, if the stresses could not reach the highest levels simultaneously, the test region becomes non-rectangular. For optimal CSALT design on non-rectangle test region, the present method is only focused on non-rectangle test region with simple boundary, and the optimization algorithm is based on experience which can not ensure to obtain the optimal plan. In this paper, considering the linear-extreme value model and the optimization goal to minimize the variance of lifetime estimate under normal stress, the optimal design method of two-stress type-I censored CSALT plan on general non-rectangular test region is proposed. First, two properties of optimal test plans are proved and the relationship of all the optimal test plans is determined analytically. Then, on the basis of the two properties, the optimal problem is simplified and the optimal design method of two-stress CSALT plan on general non-rectangular test region is proposed. Finally, a numerical example is used to illustrate the feasibility and effectiveness of the method, The result shows that the proposed method could obtain the optimal test plan on non-rectangular test regions with arbitrary boundaries. This research provides the theory and method for two-stress optimal CSALT planning on non-rectangular test regions.

Laparoscopic and endoscopic co-operative surgery for nonampullary duodenal tumors

AIM To assess the safety and feasibility of laparoscopic and endoscopic co-operative surgery(LECS) for early nonampullary duodenal tumors.METHODS Twelve patients with a non-ampullary duodenal tumor underwent LECS at our hospital. One patient had two mucosal lesions in the duodenum. The indication for this procedure was the presence of duodenal tumors with a low risk for lymph node metastasis. In particular, the tumors included small(less than 10 mm) submucosal tumors(SMT) and epithelial mucosal tumors, such as mucosal cancers or large mucosal adenomas with malignant suspicion. The LECS procedures, such as full-thickness dissection for SMT and laparoscopic reinforcement after endoscopic submucosal dissection(ESD) for epithelial tumors, were performed for the 13 early duodenal lesions in 12 patients. Here we present the short-term outcomes and evaluate the safety and feasibility of this new technique.RESULTS Two SMT-like lesions and eleven superficial epithelial tumor-like lesions were observed. Seven and Six lesions were located in the second and third parts of the duodenum, respectively. All lesions were successfully resected en bloc. The defect in the duodenal wall was manually sutured after resection of the duodenal SMT. For epithelial duodenal tumors, the ulcer bed was laparoscopically reinforced via manual suturing after ESD. Intraoperative perforation occurred in two out of eleven epithelial tumor-like lesions during ESD; however, they were successfully laparoscopically repaired. The median operative time and intraoperative estimated blood loss were 322 min and 0 mL, respectively. Histological examination of the tumors revealed one adenoma with moderate atypia, ten adenocarcinomas, and two neuroendocrine tumors. No severe postoperative complications(Clavien-Dindo classification grade Ⅲ or higher) were reported in this series, but minor leakage secondary to pancreatic fistula occurred in one patient.CONCLUSION LECS can be a safe and minimally invasive treatment option for non-ampullary early duodenal tumors.

A mutation of the start codon in the X region of hepatitis B virus DNA in a patient with non-B,non-C chronic hepatitis

There are cases of hepatitis involving occult hepatitis B virus(HBV)infection in which,even though the HB surface antigen(HBsAg)is negative,HBV-DNA is detected by a polymerase chain reaction(PCR).We con-ducted a sequence analysis of the entire HBV region in a case of non-B non-C chronic hepatitis in a 46-yearold female.A diagnosis of non-B non-C chronic hepatitis was made.Although HBV markers,such as HBs antibody(anti-HBs),anti-HBc,HBeAg and anti-HBe,were negative,HBV-DNA was positive.Nested PCR was performed to amplify the precore region of HBV-DNA and all remaining regions by long nested PCR.Sequence analysis of the two obtained bands was conducted by direct sequencing.Compared with the control strains,the ATG(Methionine)start codon in the X region had mut ated to GTG(Valine).It is assumed that a mutation at the start codon in the X region may be the reason why HBV markers are negative in some cases of hepatitis that involve occult HBV infection.

Molecular Detection of Mutations within the Quinolone Resistance-Determining Regions in Non Typhoidal Salmonella Isolates from Malaysia

Introduction: The efficacy of chemotherapy in bacteraemia caused by non-typhoidal Salmonella (NTS) is compromised by antibiotic resistance. Objective: This study was undertaken to describe the mechanism of resistance among clinical NTS isolates. Materials & Methodology: Thirty of NTS were isolated from blood (n = 19), stool (n = 10) and bronchioalveolar lavage (BAL;n = 1) respectively. These isolates were tested for susceptibility testing by disc diffusion method against ampicillin, gentamicin, tetracycline, co-trimoxazole, nalidixic acid, ciprofloxacin and ceftriaxone. Epsilometer tests (E-test) for nalidixic acid and ciprofloxacin were performed for nalidixic acid resistant isolates by disc diffusion method. DNA sequencing was carried out on six of the nalidixic acid resistant Salmonella Enteritidis isolates to identify mutations within quinolones resistance determining regions (QRDR) of gyrA, gyrB, parC and parE genes. Results: Resistance rates of NTS isolates from blood, stool, and BAL were respectively 37%, 20% and 0% for ampicillin, 79%, 40% and 0% for tetracycline, 32%, 40% and 0% for co-trimoxazole, 37%, 10% and 100% for nalidixic acid. Eight isolates were resistant to nalidixic acid and had exhibited reduced susceptibility towards ciprofloxacin by E-test. Mutation within QRDR was detected in gyrA gene (n = 6;Asp 47 → His [3], Asp 51 → Asn [1], Asp 73 → Gly [1], and Gly 48 → Asp [1]) and double mutation was detected in parE gene (n = 3;Gly 48 → Asp [3], Glu 82 → Ser [3]). Out of six isolates, three isolates were found to have both gyrA and parE gene mutations. Conclusions: There was no mutation observed in gyrB and parC gene. Mutation in gyrA gene was sufficient to induce decreased susceptibility to ciprofloxacin. Variation in amino acid sequences are novel, while detection of other gene mutation was uncommon.

A Non-Monotone Trust Region Method with Non-Monotone Wolfe-Type Line Search Strategy for Unconstrained Optimization

In this paper, we propose and analyze a non-monotone trust region method with non-monotone line search strategy for unconstrained optimization problems. Unlike the traditional non-monotone trust region method, our algorithm utilizes non-monotone Wolfe line search to get the next point if a trial step is not adopted. Thus, it can reduce the number of solving sub-problems. Theoretical analysis shows that the new proposed method has a global convergence under some mild conditions.

A Non-Asymptotic Confidence Region with a Fixed Size for a Scalar Function Value: Applications in C-OTDR Monitoring Systems

In this paper we will investigate some non-asymptotic properties of the modified least squares estimates for the non-linear function f(λ*) by observations that nonlinearly depend on the parameter λ*. Non-asymptotic confidence regions with fixed sizes for the modified least squares estimate are used. The obtained confidence region is valid for a finite number of data points when the distributions of the observations are unknown. Asymptotically the suggested estimates represent usual estimates of the least squares. The paper presents the results of practical applications of the proposed method in C-OTDR monitoring systems.

中国城市碳排放绩效:动态分解、空间差异与影响因素

以非径向方向距离函数为框架,构造全要素碳排放绩效指数对中国2006—2019年城市碳排放治理绩效进行测度。在此基础上从经济含义、跨期动态变化、区域均衡等层面对全要素碳排放绩效指数进行多维分解,检验中国城市碳排放绩效的影响因素。结果表明:第一,样本期内全国城市平均全要素碳排放绩效指数总体呈波动上升态势,动态分解结果显示,中国各地的平均碳排放绩效水平不断改进,创新效应对其贡献逐年增大但赶超效应贡献不足;第二,空间分异方面,珠三角、长三角、粤闽浙沿海、长江中游等东部地区城市群不仅平均碳排放绩效水平普遍较高,且碳排放绩效的增长速度较快,中西部地区仅成渝城市群碳排放绩效表现较好,中原、京津冀等城市群近年来碳排放绩效的改善速度较快;第三,基尼系数测度及其分解显示,近年中国城市碳排放绩效指数的分异程度逐步加深,分异成因主要为城市群组间差异,城市群内部差异贡献度较低;第四,Lasso分析及双固定面板模型分析结果显示,经济发展水平、清洁能源使用、金融发展、绿色环保和科技支持能够有效改善城市层面的碳排放绩效,能源消耗强度和第二产业就业人员比重对碳排放绩效具有负面影响;最后,城市群因子探测结果显示,各城市群间的驱动因子存在一定差异。

旱区陆面非降水性水分研究进展和展望

随着全球气候变暖,自然生态系统和水资源压力不断增加,加剧了全球水资源的短缺。旱区非降水性水分(Non-precipitation Water,NPW),作为一种重要的水源,对旱区生态系统和陆面水分平衡具有显著影响。本文基于国内外非降水性水分研究现状,总结其在西北旱区的观测方法、变化特征、形成机制及对陆面水分平衡和作物的影响。在结合非降水性水分研究国际趋势的基础上,指出当前研究的不足和问题,以及未来研究的重点方向:揭示陆面非降水性水分的复杂形成机制,加强对不同气候区和下垫面非降水性水分的认知,建立专门的陆面非降水性水分观测系统,发展其在数值模式中的参数化,以及制定陆面非降水性水分开发利用的技术标准。

基于WEP-QTP模型的近65 a黄河源区径流演变分析

为研究黄河源区径流演变规律,以WEP-QTP(The Water and Energy transfer Processes in the Qinghai⁃Tibet Plateau)模型为基础构建基于水热耦合的黄河源区冻土水文模型。采用玛曲站2019—2021年冻融期逐日土壤温度及土壤液态含水率对模型进行验证,率定期及验证期决定系数(R2)均值为0.8左右,均方根误差(RMSE)均值分别为1.0℃及0.04左右;采用8个冻土监测点1971—2000年冻融期逐日冻土深度进行验证,决定系数(R2)均值为0.89,均方根误差(RMSE)均值为214.81 mm。模型模拟黄河源区1956—2020年逐月流量过程,效率系数(NSE)为0.8左右,相对误差(RE)为5%左右,表明模型能较好地模拟黄河源区径流过程。利用M-K趋势检验分析得到1956—2020年黄河源区径流呈不显著增加趋势,其变化趋势是降水与气温共同影响的结果。冻融期、非冻融期径流与全年趋势一致。降水增加、气候变暖及冻土退化使径流组分发生变化,地表径流及地下径流均呈增加趋势,但地下径流在全年及冻融期增加趋势更加显著。

表征与非表征视角下饮食地域刻板印象的验证与测量

饮食在地域之间不断交融,跨越国界、民族及社区,既成为一种表征的文化意义结构,也成为非表征的日常参与和实践,在表征与非表征视角下,饮食地域刻板印象的存在与具体内容值得探讨。为了厘清这一问题,本研究采用混合研究法对饮食地域刻板印象进行验证和测量。子研究1使用了问卷调查法检验外显层面的饮食地域刻板印象,子研究2采用语义启动的实验范式检验内隐层面的饮食地域刻板印象。研究发现,被试在内隐和外显层面均持有饮食地域刻板印象,主要包括主食偏好、口味偏好、份量偏好和具体菜品4个维度。本研究验证了饮食地域刻板印象具有外显和内隐、经验与情景并存的特征,这扩展了表征与非表征理论相结合的饮食社会文化地理知识。

数字技术赋能京津冀产业结构升级的效应研究

数字技术的应用与发展,是现阶段中国经济高质量发展的需要,是产业结构升级的重要技术支撑。以京津冀地区13市2011—2021年面板数据为基础,运用双固定效应模型、中介效应模型、门槛效应模型等多种计量方法对数字技术对产业结构升级的影响进行实证分析。研究结果表明,数字技术对产业结构升级具有促进效应;在地区异质性分析中发现数字技术与产业结构升级的关系在资源型与非资源型城市间尚未产生显著性差异。进一步分维度来看,数字技术对产业结构升级的促进作用主要源于数字技术应用;随着产业结构升级分位点位置的上升,数字技术对产业结构升级的促进效应呈现逐渐增强的特征,使京津冀地区存在数字鸿沟的风险。此外,数字技术对产业结构升级的影响具有经济发展水平的门槛特征,当经济发展水平不断跨过门槛值时,数字技术对产业结构升级的促进作用会增强;数字技术可以通过投资拉动和金融发展效率促进产业结构升级,而市场消费需求和人力资本结构高级化则在其影响中起到遮掩效应。

非小细胞肺癌组织中miR-363-3p、SOX4 mRNA表达及对上皮间质转化进程的影响

目的探讨非小细胞肺癌组织中微小RNA-363-3p(miR-363-3p)、性别决定区Y框蛋白4(SOX4)表达及对上皮间质转化(EMT)进程的影响。方法收集行手术切除的84例非小细胞肺癌患者的癌及其癌旁组织。采用实时荧光定量聚合酶链反应检测癌及癌旁组织miR-363-3p、SOX4 mRNA表达,免疫组化SP法检测癌及癌旁组织中E-cadherin、Vimentin表达。比较不同病理特征患者癌组织中miR-363-3p、SOX4 mRNA表达,采用Spearman秩相关分析癌组织miR-363-3p、SOX4 mRNA表达与E-cadherin、Vimentin相关性。使用相对超危险度比(RERI)、归因比(AP)、交互作用指数(SI)分析miR-363-3p、SOX4参与EMT进程的交互作用。结果癌组织中miR-363-3p表达低于癌旁组织,SOX4 mRNA表达高于癌旁组织(P均<0.05);癌组织中miR-363-3p、SOX4 mRNA表达与性别、年龄、吸烟史、肿瘤最大径无关(P均>0.05),与分化程度、TNM分期有关(P均<0.05);癌组织E-cadherin阳性表达率低于癌旁组织,Vimentin阳性表达率高于癌旁组织(P均<0.05);癌组织miR-363-3p与E-cadherin表达呈正相关(r=0.491,P<0.05),与Vimentin表达呈负相关(r=-0.506,P<0.05);癌组织SOX4 mRNA与E-cadherin表达呈负相关(r=-0.527,P<0.05),与Vimentin表达呈正相关(r=0.463,P<0.05)。癌组织miR-363-3p、SOX4对EMT进程存在负向交互作用(RERI=29.639,AP=70.91,SI=3.656)。结论非小细胞肺癌组织中miR-363-3p、SOX4异常表达与EMT有关,且二者对EMT进程存在负向交互作用。

基于PDA模型的中国水资源消耗及其政策影响因素研究

利用中国2011—2020年31个省(自治区、直辖市)三大产业面板数据,基于生产理论分解方法,选取多层级共同前沿DEA模型中的非径向距离函数,对中国水资源消耗及其政策影响因素进行了分析。结果表明,西部地区正逐渐成为中国第二大水资源消耗区域,且中国水资源消耗从“一二三”向“一三二”的产业用水态势转变;在提出的新分解因素中,产业结构调整、区域均衡发展和市场化改革分别有助于减少西、中、东部地区的水资源消耗;在所有的分解因素中,技术效率对减少水资源消耗的贡献最为突出。提出了加快产业结构调整、提高产业数字化和绿色化对水资源利用的正向影响等政策建议。

对外直接投资对中国区域经济韧性影响研究

对外直接投资(OFDI)是影响中国区域经济韧性的重要因素。基于2005—2019年省级面板数据,运用非空间面板模型、空间面板模型和中介效应模型实证分析了OFDI对中国区域经济韧性的影响及作用机制。研究表明:OFDI总体上促进了中国区域经济韧性的提升,该结论在一系列稳健性检验后依然成立;OFDI对邻近地区经济韧性的提升具有溢出效应。中介机制检验发现,OFDI能通过人力资本和技术创新机制间接提升中国区域经济韧性。空间异质性分析表明,OFDI促进东部地区和中西部地区经济韧性的提升,且对东部地区经济韧性的推动作用高于中西部地区;时间异质性分析表明,金融危机抵抗期OFDI对中国区域经济韧性的提升具有抑制作用,而在金融危机恢复期和转型期具有促进作用。

云南小碗红糖非遗品牌发展路径研究

随着农业的发展,农产品品牌化对推进乡村振兴和农业农村现代化发挥着重要作用。本文以云南省巧家县红糖产业为研究对象,通过实地调研和网络调研相结合的方法,总结巧家县红糖产业发展的机遇与优势,发现巧家县小碗红糖品牌发展存在品牌价值缺位、产品附加值不高、发展合力不足、培育机制不完善等问题。为此,提出丰富品牌多元要素、优化生产质量标准、壮大本土经营主体、明晰品牌培育机制等策略,为巧家小碗红糖品牌建设进一步完善提供建议与参考。

地方环境对流动人口回流意愿的非线性影响——基于流入地与户籍地的比较分析

基于2017年流动人口动态监测调查数据,以流动人口回流意愿为响应变量,以流入地和户籍地的地方环境、个人及家庭因素为解释变量,引入机器学习领域的梯度提升决策树模型,重点探究不同地区地方环境对流动人口回流意愿的非线性影响及阈值效应。研究发现:①户籍地和流入地的地方环境对流动人口回流意愿的总体贡献率达44.1%,是影响回流意愿的重要因素,且两地贡献率大致相当。②地方环境因素与回流意愿间的非线性与线性关系并存。其中,医疗卫生资源、基础教育资源、空气污染状况等因素对回流意愿具有明显的非线性影响,而经济增长、气温条件则以线性影响为主。研究揭示了中国国内城-乡人口回流的特殊性与复杂性,有助于深化新时期人口迁移研究,并为地方人口政策制定提供科学借鉴。

校园欺凌与攻击性行为对青少年非自杀性自伤的双重影响:一项横断面研究

目的探讨青少年非自杀性自伤(non-suidical self-injury,NSSI)的发生和发展机制,关注校园欺凌和攻击性行为与青少年NSSI之间的关联,以期为预防和干预这一问题提供理论依据和实践建议。方法采用横断面研究设计,研究对象为15987位中国辽宁、上海和江西三个省的初高中学生,代表了不同的社会、经济和文化背景。通过问卷调查法收集数据,并运用相关分析、回归分析和结构方程模型等统计方法进行分析,以揭示各变量间的关系及相互作用。结果校园欺凌与NSSI呈正向关系(非标准化系数=0.420,标准化系数=0.247,Z=18.123,P<0.001),欺凌程度越高,自伤风险也越高。攻击性行为与NSSI之间同样存在正向关系(非标准化系数=0.230,标准化系数=0.201,Z=14.301,P<0.001),攻击性行为越强烈,自伤风险也越高。校园欺凌对攻击性行为的影响显著(非标准化系数=1.052,标准化系数=0.708,Z=75.223,P<0.001),欺凌程度越高,攻击性行为也越严重。结构方程模型结果表明,模型在解释校园欺凌、攻击性行为与青少年NSSI关系方面具有较好的拟合效果。结论研究发现,校园欺凌和攻击性行为对青少年NSSI具有显著影响,且青少年的欺凌和攻击性行为存在地区差异。预防和干预措施应综合学校、家庭和社会力量,加强师生间沟通,提高教师对问题行为的识别和干预能力,增进家长对青少年心理健康的关注,以降低青少年NSSI风险。

卸载状态下非均质圆形寒区隧道围岩弹塑性统一解

以统一强度理论作为卸载状态下寒区隧道冻结围岩屈服准则,综合考虑围岩非均质特性和中间主应力效应对冻结围岩强度影响,建立寒区隧道应力位移弹塑性力学模型,联合各区域边界条件,计算获得冻结围岩均质与非均质状态下,弹性解、塑性统一解以及塑性区半径的隐式方程,分别对其应力位移场讨论分析。研究表明:考虑冻结围岩的非均质特性,塑性区环向应力峰值增大40%,塑性区范围相对减少40.4%,内壁位移减少9.3%,弹性极限承载力提高41%,塑性极限承载力提高14%,影响显著。中间主应力效应能充分发挥非均质冻结围岩承载潜能,计算得到的承载力明显增大,塑性半径明显减小。所得结果可为寒区隧道开挖支护设计以及数值模拟,提供理论指导。

SOX9及其增强子在哺乳动物性别决定中的研究进展

性别决定指的是胚胎发育早期,在转录因子的精确调控下,具有双重分化潜能的性腺向睾丸(雄性)或卵巢(雌性)方向转变的过程。SOX9(SRY-boxtranscription factor9)是哺乳动物发育过程中的多功能转录因子,在性别决定及随后的雄性生殖器官发育中发挥关键作用。近年来相关研究表明,SOX9上游的多个增强子也在性别决定过程中扮演着重要的角色。本文主要对SOX9及其与性腺发育相关的增强子在性别决定中的研究进展进行了综述,以期加深人们对SOX9在性别决定中调控作用机制的认识,为加快动物性别控制技术研究提供理论参考。