Clinical outcome and prognostic factors of T4N0M0 colon cancer after R0 resection:A retrospective study

BACKGROUND Paradoxically,patients with T4N0M0(stage II,no lymph node metastasis)colon cancer have a worse prognosis than those with T2N1-2M0(stage III).However,no previous report has addressed this issue.AIM To screen prognostic risk factors for T4N0M0 colon cancer and construct a prognostic nomogram model for these patients.METHODS Two hundred patients with T4N0M0 colon cancer were treated at Tianjin Medical University General Hospital between January 2017 and December 2021,of which 112 patients were assigned to the training cohort,and the remaining 88 patients were assigned to the validation cohort.Differences between the training and validation groups were analyzed.The training cohort was subjected to multi-variate analysis to select prognostic risk factors for T4N0M0 colon cancer,followed by the construction of a nomogram model.RESULTS The 3-year overall survival(OS)rates were 86.2%and 74.4%for the training and validation cohorts,respectively.Enterostomy(P=0.000),T stage(P=0.001),right hemicolon(P=0.025),irregular review(P=0.040),and carbohydrate antigen 199(CA199)(P=0.011)were independent risk factors of OS in patients with T4N0M0 colon cancer.A nomogram model with good concordance and accuracy was constructed.CONCLUSION Enterostomy,T stage,right hemicolon,irregular review,and CA199 were independent risk factors for OS in patients with T4N0M0 colon cancer.The nomogram model exhibited good agreement and accuracy.

Comparative efficacy and safety between endoscopic submucosal dissection,surgery and definitive chemoradiotherapy in patients with cT1N0M0 esophageal cancer

BACKGROUND Endoscopic submucosal dissection(ESD)and surgical resection are the standard of care for cT1N0M0 esophageal cancer(EC),whereas definitive chemoradiotherapy(d-CRT)is a treatment option.Nevertheless,the comparative efficiency and safety of ESD,surgery and d-CRT for cT1N0M0 EC remain unclear.AIM To compare the efficiency and safety of ESD,surgery and d-CRT for cT1N0M0 EC.METHODS We retrospectively analyzed the hospitalized data of a total of 472 consecutive patients with cT1N0M0 EC treated at Sun Yat-sen University Cancer center between 2017-2019 and followed up until October 30th,2022.We analyzed demographic,medical recorded,histopathologic characteristics,imaging and endoscopic,and follow-up data.The Kaplan-Meier method and Cox proportional hazards modeling were used to analyze the difference of survival outcome by treatments.Inverse probability of treatment weighting(IPTW)was used to minimize potential confounding factors.RESULTS We retrospectively analyzed patients who underwent ESD(n=99)or surgery(n=220)or d-CRT(n=16)at the Sun Yat-sen University Cancer Center from 2017 to 2019.The median follow-up time for the ESD group,the surgery group,and the d-CRT group was 42.0 mo(95%CI:35.0-60.2),45.0 mo(95%CI:34.0-61.75)and 32.5 mo(95%CI:28.3-40.0),respectively.After adjusting for background factors using IPTW,the highest 3-year overall survival(OS)rate and 3-year recurrence-free survival(RFS)rate were observed in the ESD group(3-year OS:99.7% and 94.7% and 79.1%;and 3-year RFS:98.3%,87.4% and 79.1%,in the ESD,surgical,and d-CRT groups,respectively).There was no difference of severe complications occurring between the three groups(P≥0.05).Multivariate analysis showed that treatment method,histology and depth of infiltration were independently associated with OS and RFS.CONCLUSION For cT1N0M0 EC,ESD had better long-term survival and lower hospitalization costs than those who underwent d-CRT and surgery,with a similar rate of severe complications occurring.

具有多级适应性休假和Min(N,V)-策略的Geo=G=1排队系统分析

本文研究具有多级适应性休假和Min(N,V)-策略的Geo/G/1排队系统,运用更新过程理论,全概率分解技术和z-变换工具,分析在时刻点n^(+)的队长瞬态概率分布的z-变换表达式.此外,基于瞬态分析,使用洛必达法则得到系统在时刻点n+的队长稳态分布的递推表达式,然后给出稳态队长分布的概率母函数以及平均稳态队长的表达式.接着,探讨在不同时刻点n^(-)、n和外部观察点的稳态概率分布.最后,在建立费用结构模型下,由更新报酬过程理论获得系统长期运行单位时间内所产生的成本期望费用的表达式,并通过数值实例讨论最优控制策略N^(*)以及当连续休假次数为正整数J时的二维最优控制策略(N^(*),J^(*)).

Effect of toroidal mode coupling on explosive dynamics of m/n=3/1 double tearing mode

The CLT code was used to quantitatively study the impact of toroidal mode coupling on the explosive dynamics of the m/n=3/1 double tearing mode.The focus of this study was on explosive reconnection processes,in which the energy bursts and the main mode no longer dominates when the separation between two rational surfaces is relatively large in the medium range.The development of higher m and n modes is facilitated by a relatively large separation between two rational surfaces,a small q_(min)(the minimum value of the safety factor),or low resistivity.The relationships between the higher m and n mode development,explosive reconnection rate,and position exchange of 3/1 islands are summarized for the first time.Separation plays a more important role than q_(min)in enhancing the development of higher m and n modes.At a relatively large separation,the good development of higher m and n modes greatly reduces the reconnection rate and suppresses the development of the main mode,resulting in the main mode not being able to develop sufficiently large to generate the position changes of 3/1 islands.

Effect of(Cr,V)_(2)(C,N)on the Microstructure and Mechanical Properties of WC-10Co Cemented Carbides

WC-10Co cemented carbides with finer WC and narrower grain size distributions are produced by using(Cr,V)_(2)(C,N)as grain growth inhibitors.As a result,with the increase of(Cr_(0.9),V_(0.1))_(2)(C,N)and(V_(0.9),Cr_(0.1))_(2)(C,N),the grains size of WC and mean free path of Co phase decrease,and adjacency of WC increases.Refinement and homogenization of grains enhance the transverse rupture strength(TRS)and the hardness.Meanwhile,the deflection and bridging of cracks keep the fracture toughness at a respectable level.The WC-10Co-0.6(Cr_(0.9),V_(0.1))_(2)(C,N)-0.025(V_(0.9),Cr_(0.1))_(2)(C,N)cemented carbides exhibit excellent comprehensive mechanical properties with the TRS of 4602.6 MPa,hardness of 1835 kg/mm^(2),and fracture toughness of 10.39 MPa·m^(1/2),respectively.However,the large pores are caused by excess N larger than 0.03 wt%and deteriorates the mechanical properties.We provide a new approach to WC-Co cemented carbides preparation with a narrow grain size distribution by adding novel grain growth inhibitors.

Comparative Study of the Physicochemical Quality of the Waters of the Méné River (Sassandra Watershed, Ivory Coast) in the Dry Season and in the Rainy Season

The study carried out on the waters of the Méné River led to an overall assessment of its water quality during the dry season and the rainy season. The analysis focused on eight (8) water samples taken from the river during a period of dry season (January-February) and a period of rainy season (June and September). The various physicochemical parameters were measured according to Afnor standardized methods. The readings of temperature, turbidity, pH and conductivity made it possible to account for the disturbances occurring in water quality. A temporal variation correlated with the seasons (dry or rainy) is noted. Turbidity depends on the concentration of suspended solids (SS) in the water and drained particles and therefore on the seasons. Just like the temperature, the conductivity changes with the season. The waters of the Méné River are generally acidic. The results obtained show that there is a low level of pollution by chlorides, phosphates, nitrites and nitrates. A slight pollution of the waters of Méné in organic matter (chemical oxygen demand values are less than 25 mg∙L−1 during dry season and 32.33 ± 4.73 mg∙L−1 during rainy season) was observed. The concentrations of metallic trace elements such as iron, manganese and aluminum indicate significant pollution of these waters by these elements. Overall, the waters of the Méné River are of satisfactory quality because all the physicochemical parameters analyzed have values below standards during the dry season as well as during the rainy season with the exception of COD and a few metallic trace elements.

(m,n)-coherent Rings and FP(m,n)-projective Modules

In this paper,we introduce the notions of_((m,n))-coherent rings and FP_((m,n))-projective modules for nonnegative integers m,n.We prove that(FP_((m,n))-Proj,(FPn-id)_(≤m))is a complete cotorsion pair for any m,n≥0 and it is hereditary if and only if the ring R is a left n-coherent ring for all m≥0 and n≥1.Moreover,we study the existence of FP_((m,n))-Proj covers and envelopes and obtain that if FP_((m,n))-Proj is closed under pure quotients,then FP_((m,n))-Proj is covering for any n≥2.As applications,we obtain that every R-module has an epic FP_((m,n))-Proj-envelope if and only if the left FP_((m,n))-global dimension of R is at most 1 and FP_((m,n))-Proj is closed under direct products.

基于改进COF-YOLO v8n的油茶果静态与动态检测计数方法

针对自然环境下油茶果存在严重遮挡、近景色、小目标等现象,使用YOLO网络存在检测精度低、漏检现象严重等问题,提出对YOLO v8n网络进行改进。首先使用MPDIOU作为YOLO v8n的损失函数,有效解决因为果实重叠导致的漏检问题;其次调整网络,向其中加入小目标检测层,使网络能够关注小目标油茶以及被树叶遮挡的油茶;最后使用SCConv作为特征提取网络,既能兼顾检测精度又能兼顾检测速度。改进COF-YOLO v8n网络精确率、召回率、平均精度均值分别达到97.7%、97%、99%,比未改进的YOLO v8n分别提高3.2、4.8、2.4个百分点,其中严重遮挡情况下油茶检测精确率、召回率、平均精度均值分别达到95.9%、95%、98.5%,分别比YOLO v8n提高4.0、9.1、4.6个百分点。因此改进后COF-YOLO v8n网络能够明显提高油茶在严重遮挡、近景色、小目标均存在情况下的识别精度,减小油茶的漏检。此外,模型能够实现动、静态输入条件下油茶果计数。动态计数借鉴DeepSORT算法的多目标跟踪思想,将改进后COF-YOLO v8n的识别输出作为DeepSORT的输入,实现油茶果实的追踪计数。所得改进模型具有很好的鲁棒性,且模型简单可以嵌入到边缘设备中,不仅可用于指导自动化采收,还可用于果园产量估计,为果园物流分配提供可靠借鉴。

基于改进YOLO v5n的舍养绵羊行为识别方法

日常行为是家畜健康状况的重要体现,在传统的行为识别方法中,通常需要人工或者依赖工具对家畜进行观察。为解决以上问题,基于YOLO v5n模型,提出了一种高效的绵羊行为识别方法,利用目标识别算法从羊圈斜上方的视频序列中识别舍养绵羊的进食、躺卧以及站立行为。首先用摄像头采集养殖场中羊群的日常行为图像,构建绵羊行为数据集;其次在YOLO v5n的主干特征提取网络中引入SE注意力机制,增强全局信息交互能力和表达能力,提高检测性能;采用GIoU损失函数,减少训练模型时的计算开销并提升模型收敛速度;最后,在Backbone主干网络中引入GhostConv卷积,有效地减少了模型计算量和参数量。实验结果表明,本研究提出的GS-YOLO v5n目标检测方法参数量仅为1.52×10^(6),相较于原始模型YOLO v5n减少15%;浮点运算量为3.3×10^(9),相较于原始模型减少30%;且平均精度均值达到95.8%,相比于原始模型提高4.6个百分点。改进后模型与当前主流的YOLO系列目标检测模型相比,在大幅减少模型计算量和参数量的同时,检测精度均有较高提升。在边缘设备上进行部署,达到了实时检测要求,可准确快速地对绵羊进行定位并检测。

TGEV的sM、M和N基因克隆及特征分析

参照GenBank中收录的TGEVsM、M和N基因序列各设计1对特异引物,经RTPCR扩增获得了TS株的相应基因片段,分别约为346、932和1217bp,其大小与预计的目的片段相符。与其他毒株的相应基因相比较,并经剪接后,TS株的sM、M和N基因全长分别为248、789和1149bp,各编码82个、262个和382个氨基酸;TS株与Purdue株、TFI株和961933株的sM基因核苷酸序列同源性分别为95.2%、92.7%和90.2%;推导氨基酸的同源性分别为95.9%、97.2%、98.8%;与Purdue株、TFI株、TGEVH株和961933株的M基因核苷酸序列同源性分别为95.2%、98.0%、99.6%和95.0%;推导氨基酸的同源性分别为97.0%、97.3%、98.5%、93.5%;与Purdue株、TFI株、FS722/70株、Korea株、TO14株、TGEVH株和961933株的N基因核苷酸序列同源性分别为98.1%、97.7%、99.0%、98.3%、99.2%、99.0%和95.9%,推导氨基酸的同源性分别为97.9%、98.4%、99.0%、97.7%、99.5%、96.2%、96.6%。并对TS株基因间的保守序列和sM、M和N基因及其编码的相应氨基酸的结构特征进行了分析,发现sM和N基因在TGEV中保守;并提示在我国不仅存在有2个不同亚基因型的TGEV,而且我国的TGEV可能是输入性的。

9Cr-1 Mo-V-Nb-N钢管的热处理工艺的优化

采用单因素比较试验法和正交试验法对 9Cr 1Mo V Nb N钢厚壁无缝钢管热处理工艺参数进行了优化研究 ,通过 16个力学性能指标的多指标综合量化评估法得到了优化的热处理工艺参数。结果表明 ,优化工艺的正火温度为 10 5 5℃± 15℃ ,回火温度 76 5℃± 15℃。

因子von Neumann代数上的非线性(m,n)导子

设m和n是任意固定的非零整数,且(m+n)(m-n)≠0,M是一个因子von Neumann代数,δ是M上的一个映射(没有可加性或连续性假设).用矩阵分块方法证明了:若对任意的A,B∈M,有mδ(AB)+nδ(BA)=mδ(A)B+mAδ(B)+nδ(B)A+nBδ(A),则δ是一个可加导子.

V-M/TiO_2(M=Cu、Cr、Ce、Mn、Mo)催化燃烧含氯有机废气

以TiO2为载体,采用浸渍法制备V-M/TiO2(M=Cu、Cr、Ce、Mn、Mo)双金属氧化物催化剂,考察其催化燃烧氯苯、二氯甲烷等含氯有机废气(CVOCs)的性能,并通过XRD、BET、H2-TPR和NH3-TPD对催化剂进行了表征.结果表明,V-Mo/TiO2催化剂比表面积最大,催化剂表面活性组分的高分散性和良好的酸性分布使得V-Mo/TiO2能够在260oC将氯苯完全转化为CO2和HCl.而V-Mn/TiO2则具有丰富的活性氧,可显著提高催化剂深度氧化二氯甲烷的能力,在380℃时二氯甲烷即可完全燃烧,并且反应对CO2有着很高的选择性.

590MPa级热轧V-N高强车轮钢组织性能控制

对一种低成本V-N微合金化钢进行了控轧控冷实验,探讨了相变机理与析出行为,并系统地研究了其综合力学性能.结果表明,显微组织为多边形铁素体、粒状贝氏体及少量的针状铁素体,纳米尺度V(C,N)析出质点弥散地分布于铁素体或贝氏体铁素体基体内部.抗拉强度615MPa实验钢具有优良的断后延伸率,冷弯性能合格,扩孔率达到95%,满足轮辐用钢的加工要求,低温冲击性能良好.细晶强化、位错强化、析出强化、相变强化为主要强化机制.

基于改进YOLO v8n模型的散养蛋鸡个体行为识别方法与差异分析

家禽行为与其生理状态密切相关,可利用行为数据对家禽健康状况进行评估。统计个体行为数据需要进行蛋鸡行为识别和个体身份识别,针对行为识别过程中,蛋鸡体型小、聚集遮挡,养殖环境光照变化等因素导致的蛋鸡有效特征表达不足,个体行为识别效果不理想问题,基于YOLO v8n网络构建行为识别模型,同时融合ODConv、GhostBottleneck、GAM注意力和Inner-IoU结构,通过减少图像特征丢失,放大全局交互信息,融合跨阶段特征,增强特征提取及泛化能力对模型进行改进,提升了蛋鸡采食、饮水、站立、整理羽毛、俯身搜索5种行为的识别精度。同时基于YOLO v8n模型构建了个体身份识别网络,并通过引入MobileNetV3模块对个体身份识别网络模型进行优化,提升了个体行为数据统计效率。试验结果表明,优化后行为识别模型对采食、饮水、站立、整理羽毛、俯身搜索行为识别平均精度(AP)分别达到94.4%、93.0%、90.7%、91.7%、86.9%,平均精度均值(mAP)达到91.4%,与YOLO v5n、YOLO v6n、YOLO v7-tiny、YOLO v8n相比,平均精度均值(mAP)分别提高4.8、4.1、5.5、3.5个百分点;个体身份识别模型参数量和运算量与YOLO v8n模型相比,减少1.965 1×10^(6)和6.1×10^(9)。通过分析蛋鸡行为数据发现,行为数据与温度及蛋鸡个体本身有关,温度降低时,采食、站立次数增加,饮水次数减少,整理羽毛、俯身搜索次数几乎无变化,相同温度下,不同蛋鸡个体的行为数据差异较大,且差异值与蛋鸡体型有关。试验结果为依据行为数据评判蛋鸡健康状况、养殖场精准养殖及蛋鸡个体优选奠定了基础。

国产9Cr-1Mo-V-Nb-N钢的静力强塑性研究

对国产9Cr-1Mo-V-Nb-N钢厚壁管试制品与进口住友P91钢管在供货状态下进行了比较研究,测试了2者的化学成分及静力拉伸强塑性,分析了其间存在的差异。结果表明,国产试制品质量有明显提高,但钢中杂质元素的控制与住友钢管有一定差距,静力强塑性指标仍偏低,质量均匀性也有待提高。

氮含量和TMCP对微合金V-N钢显微组织和力学性能的影响

研究了含氮量和第三代热机械加工工艺(TMCP)参数对低碳微合金V-N钢力学性能和显微组织的影响。对系列超高氮和超低碳含量的微合金V-N钢进行了不同工艺的控制轧制,对轧后试样进行了力学性能测试、显微组织观察以及晶粒大小的测定。结果表明,试验钢中氮含量的增加及终轧温度的降低均可使晶粒细化,强度相应提高,但钢中N含量过高显著损害塑性。试验钢高温变形奥氏体中析出微细VN粒子,该粒子诱导轧后冷却期间γ→α相变初期晶内铁素体的生成,产生细晶强化,是V-N微合金钢的重要强化机制之一。

SARS-CoV毒株E、M、N和S基因分子变异研究

目的通过对SARS-CoV毒株基因序列的变异分析,揭示SARS-CoV毒株出现和流行与基因进化的关系。方法对广东地区SARS-CoV毒株进行序列分析,其余毒株序列从GenBank检索,采用DNAstar5.0软件,对检索的SARS-CoV的E、M、N、S基因核苷酸序列进行比对和分析;并结合临床资料对变异毒株进行流行病学分析。结果以果子狸冠状病毒(SZ-3)为基准,102株人类毒株中,6株毒株E基因的4个氨基酸发生置换,两株毒株发生缺失变异;果子狸毒株M基因的第5位丝氨酸置换为人类毒株甘氨酸并减少1个糖蛋白位点,此外M基因有38株毒株发生8个氨基酸置换变异;6株毒株N基因发生氨基酸置换,3株毒株发生缺失变异;人类毒株S基因中9个氨基酸全部发生变异并增加1个糖蛋白位点,与果子狸毒株不同比例占0.72%(9/1255);部分毒株中S基因的27个氨基酸在发生置换变异,7株毒株发生缺失变异。结论冠状病毒S基因中9个氨基酸置换和1个糖蛋白位点影响,可能导致人类SARS-CoV毒株出现和SARS流行;SARS流行持续和传播扩大与S基因进化变异相一致。所以认为,SARS-CoV毒株S基因变异可能在SARS出现和流行中发挥极其重要的作用。

Nb含量对W3Mo2Cr4V(Nb)高速钢组织和力学性能的影响

研究了0～1.5％Nb对25 kg真空感应炉冶炼的W3M02Cr4V钢(％:0.8～1.1C、3.8～4.1Cr、2.9～3.2W、1.8～2.1Mo、1.0～1.3V)组织和力学性能的影响。试验结果表明:随着Nb含量提高,铸态组织中铌碳化物增多;淬火奥氏体晶粒变细;1180℃淬火时,1.2％～1.5％Nb钢比≤0.1％Nb钢HRC值提高了6.0;二次硬化能力和红硬性也得到了提高;使钢在较高淬火温度下的机械性能得到改善。

Photochemical Efficiency of PSⅡ and Membrane Lipid Peroxidation in Leaves of indica and japonica Rice (Oryza sativa) Under Chilling Temperature and Strong Light Stress Conditions

Relationships between fluorescence parameters and membrane lipid peroxidation in leaves of indica and japonica rice (Oryza sativa L.) during later growth stage were studied under chilling temperature and strong light stress conditions. Results showed that D1 protein contents of PSⅡ in photosynthetic apparatus dropped, the generation of antheraxanthin (A) and zeaxanthin (Z) of xanthophyll cycle were inhibited partly, PSⅡ photochemical efficiency (F v/F m)and non-photochemical quenching (q N) were also decreased obviously. In addition, endogenous active oxygen scavenger—superoxide dismutase (SOD) reduced, superoxide anion radical (O -· 2) and malondialdehyde (MDA) accumulated, as a result, photooxidation of leaves occurred under chilling temperature and strong light stress conditions. Obvious differences in the changes of the above mentioned physiological parameters between indica and japonica rice were observed. Experiments in leaves treated with inhibitors under chilling temperature and strong light conditions showed that indica rice was more sensitive to chilling temperature with strong light and subjected to photooxidation more than japonica rice. Notable positive correlation between D1 protein contents and F v/F m or (A+Z)/(A+Z+V), and a marked negative correlation between F v/F m and MDA contents were obtained by regression analysis in indica and japonica rice during chilling temperature and strong light conditions. According to the facts mentioned above, it was inferred that PSⅡ photochemical efficiency(F v/F m) was the key index to forecast for the prediction of photooxidation under stress circumstances and the physiological basis were the synthetic capacity of D1 protein and the protection of xanthophyll cycle.