Prevalence of hepatocarcinoma-related hepatitis B virus mutants in patients in grey zone of treatment

BACKGROUND Antiviral treatment of patients with chronic hepatitis B(CHB)in the grey zone of treatment comands risk management in order to optimize the health outcome.In this sense,the identification of HBV mutants related with an increased risk of hepatocellular carcinoma(HCC)could be useful to identify subpopulations with potential indication of antiviral treatment.AIM To analyze the prevalence/persistence of hepatitis B virus(HBV)preS and basal core promoter(BCP)/precore/core variants associated to HCC development in CHB patients in the grey zone.METHODS Work was designed as a longitudinal retrospective study,including 106 plasma samples from 31 patients with CHB in the grey zone of treatment:Hepatitis B e antigen negative,HBV-DNA levels between 12-20000 IU/mL,normal or discordant transaminase levels during follow up and mild/moderate necroinflammatory activity in liver biopsy or Fibroscan(up to 9.5 kPa).Serum HBVDNA was tested using the Abbott Real Time HBV Assay and the BCP/precore/core and the hepatitis B surface antigen(HBsAg)coding regions were analyzed in positive samples by PCR/bulk-sequencing to identify the HCCrelated HBV mutants.RESULTS High-risk HCC related mutants were detected in 24(77%)patients:19(61%)in the BCP/precore/core,and 7(23%)in the HBsAg coding region(2 preS1 and 5 preS2 deletions).The prevalence of preS deletions was genotype-dependent:3/5(60%)patients with preS2 deletions and 1/2 with preS1 deletions were infected with the HBV-E genotype.Since HBV-E was the most prevalent in sub-Saharan patients,a correlation between preS deletions and ethnicity was also found:6/8(75%)sub-Saharan vs 1/19(5%)Caucasian patients had preS deletions(P=0.00016).Remarkably,this correlation was maintained in those patients infected with HBV-A,a minor genotype in sub-Saharan patients:2/2 patients infected with HBV-A from West Africa vs 0/6 of Caucasian origin had preS deletions.The HCC related variants were the major strains and persisted over time(up to 48 mo).Patients with preS deletions had a significant higher prevalence of F2 fibrosis stage than the negatives(57%vs 10%,P=0.0078).CONCLUSION HBV genetic analysis of selected populations,like sub-Saharans infected with HBV-E/A genotypes,will allow identification of subpopulations with risk of HCC development due to accumulation of high-risk HBV variants,thus commanding their increased clinical surveillance.

Experimental Study on Afforestation in the Engineering Treatment Areas in the Hydro-fluctuation Zone of the Three Gorges Reservoir:A Case Study on the Engineering Treatment Area in the Wuxi Section of the Daning River

Through the Betula nigra afforestation test in the engineering treatment area of the Wuxi Section of the Daning River in Chongqing,the feasibility of arbor vegetation restoration in the comprehensive management of the engineering treatment areas of the Three Gorges Reservoir was explored.The results showed that:(1)before the flooding in the project area,the survival rate of B.nigra seedlings was high,over 95%,and(2)in 2021,after a water storage period,affected by factors such as seedling specifications,flood and flooding time,the survival rate of the seedlings planted in 2020 was low,and the one-year-old seedlings were greatly competed by weeds and grew less.Two-year-old B.nigra seedlings were replanted in 2021,and the survival rate of the B.nigra seedlings was 100%in 2022.Two-year-old B.nigra seedlings have strong adaptability and have little impact on the stability of the engineering treatment area,and can be used as afforestation tree species in engineering treatment areas of hydro-fluctuation zones.

Influence of the Repeated Flooding on Growth and Development of Acorus calamus Vegetation in Water-level-fluctuation Zone of the Three Gorges Reservoir

[ Objective] The research aimed to study influence of the repeated flooding on growth and development of A. calamus in water-level-fluc- tuation zone of the Three Gorges Reservoir. [ Method] A. calamus plants were exposed to water under the dark conditions respectively in Septem- ber 2009 and September 2010. Then, they were taken away from the water, and grew in natural conditions in the following March and April respec- tively （ marked as S1, S2, S1 and S2）. The plant number was conducted statistics respectively. On May 7, the leaf number was made statistics. Length, width and rapid light responding curve of the leaf were determined. [ Result] Repeated flooding restrained significantly plant germination un- der the dark condition. Plant number in S1 and S2 groups decreased by 38.9% and 33.3% respectively compared with the control. It also reduced survival rate of the plant. Plant number in S2 group decreased by 16.7% （P 〈 0.05） compared with that of S2 group when they were taken away from the water. Both of flooding promoted elongation of the leaves, restrained leaves to grow wider, and also restrained leaf formation of the plants except for S1 and S1 groups. Total leaf length of a plant decreased markedly after the second flooding which in S1 and S2 groups were 50.6% and 36.9% respectively less than that after the first flooding. Total leaf number of the plant in S1and S2 groups reduced significantly, and they were only 63.1% and 38.5% respectively of the control. Compared with the first flooding, total leaf length of a plant in the control increased signifi- cantly and decreased remarkably in S2 group after the second flooding. Furthermore, light response ability of the relative electronic transfer rate （rETR） in S1 group wasn＇t significantly different from the control, and rETRmax, in S2 group was significantly less than the control. Moreover, non- photochemical quenching （NPQ） decreased remarkably in S1 and S2 groups. It indicated that A. calamus had good restore ability of the light re- sponse, but restoring of its heat dissipation capacity was slower. [ Conclusion] Repeated flooding inhibited plant growth and population recovery of A. calamus under the dark condition.

乙型肝炎不确定期与灰区的再认识

慢性乙型肝炎病毒(hepatitis B virus,HBV)感染的防治依然任重而道远.即使我国新版指南扩大了抗病毒治疗适应证,依然有一定比例的HBV感染者不符合抗病毒治疗适应证,称之为不确定期或灰区(grey zone,GZ).但当前关于不确定期或GZ的解读与判断标准较为混乱,两者之间的联系与区别还不甚清晰,不同研究所指向的对象不尽相同.但无论如何认定不确定期或GZ,其目的是为了及时、准确判断慢性HBV感染的疾病进展与是否需要及时治疗.基于GZ对应于“治疗的适应证分类”和不确定期对应于“自然史分期”的理解,本文结合国内外的研究进展阐述对慢性HBV感染不确定期与GZ的再认识.GZ即为不治疗对象(不符合抗病毒治疗适应证),而不确定期仅为难以明确归于自然史分期(不符合自然史分期)的患者,GZ应包括不确定期,而不是等同关系.对应我国新版指南标准,属于GZ的不确定期患者,建议抗病毒治疗;对应欧洲肝病学会2017年指南标准,免疫控制期与属于GZ的不确定期患者,建议抗病毒治疗.

基于ANSYS的真空热处理炉的温度场分析

利用ANSYS Workbench软件分析了管式真空热处理炉炉膛内部温度场分布,通过模拟隔热层放置位置/厚度、工件盒厚度/材质、筛网厚度/材质对炉膛内部均温区范围及其平均温度的影响,获得了不同热处理炉隔热层、工件盒与筛网的设计参数;通过优选设计参数,可使均温区长度从240 mm提升至320 mm,提升了33.33%,平均温度从958.25℃提升至962.94℃。最后采用优化后的热处理炉结构参数对负载Nd2Fe14B试样的温度场进行了仿真。结果表明,Nd2Fe14B永磁体的均温区范围及平均温度得到了明显提升,磁体平均温度从959.07℃提高到963.06℃,且磁体的温度起伏明显趋于平稳,从±1.06℃优化至±0.21℃。

区域性开放性政策与企业污染排放——来自中国开发区设立的证据

以开发区设立为准自然实验,基于1998—2007年中国工业企业和污染排放数据库,考察区域性开放性政策对企业污染排放的影响。实证研究发现,开发区设立显著降低了企业污染排放强度,且该结论在经过平行趋势检验、安慰剂检验以及其他稳健性检验后仍然成立。作用机制检验结果表明,前端控制和末端处理是开发区设立促进企业污染排放强度下降的主要原因。其中,企业内前端控制主要源自重污染能源使用减少、清洁能源使用增加以及技术创新水平提高,企业内末端处理主要是由于开发区设立增强了企业污染处理能力、提高了企业污染处理率、增加了企业的污染处理量。异质性分析显示,对于高生产率企业或行业研发密集度较高的企业,开发区设立降低企业污染排放强度的效果更明显。

某电厂低压加热器管板与壳体T型焊接接头开裂失效分析

某电厂低压加热器服役5年后,管板和壳体的T型焊缝部位发生严重开裂;通过宏观检查、断口形貌分析、金相组织分析、能谱分析(EDS)、化学成分分析和硬度检测等检验检测,对焊缝开裂原因进行了分析。分析表明:由于焊接热影响区(HAZ)存在对碱应力腐蚀开裂敏感的淬硬马氏体组织,且焊接接头未进行消应力热处理,在碱性环境中,管板焊接热影响区发生了碱脆,支裂纹在焊缝中扩展穿透造成设备失效。对T型焊接接头失效的原因进行分析,对类似场合换热器设计、制造和使用具有借鉴意义。

Development and microstructure characterization of BG110E high-strength expansion pipe

The BG110E high-strength expansion pipe was developed using medium manganese steel and subjected to a two-phase zone heat treatment process.Mechanical properties and microstructure analysis results have proven that the BG110E expansion pipe exhibits uniform elongation of more than 19%.Moreover,after undergoing expan-sion deformation,its strength,toughness,and plasticity are found to meet the stringent requirements of the P110 pipe.The microstructure of this high-strength expansion pipe,which has a strength of 110 ksi(1 ksi=6.895 MPa),consists of tempered martensite,ferrite,retained austenite,and granular bainite.The propotion of retained austenite reaches up to 12%,ensuring high plasticity and the occurrence of the transformation-induced plasticity effect during the deformation process.Consequently,it enhances the coordinated deformation ability between different phases,which significantly improves the internal yield pressure of the BG110E high-strength expansion pipe in turn.

近端不良锚定区Stanford B型主动脉夹层介入治疗方式的研究进展

近端不良锚定区Stanford B型主动脉夹层介入治疗方式主要包括弓上分支动脉重建和非弓上分支动脉重建技术。弓上分支动脉重建技术相对于非弓上分支动脉重建技术有较低的不良事件发生率。弓上分支动脉重建介入治疗方式有多种,不同的介入治疗方式对胸主动脉腔内修复术疗效亦产生不同的影响。本文就不同介入治疗方式进行综述分析,为了更深入地分析和总结不同介入治疗方式对近端不良锚定区Stanford B型主动脉夹层的优、劣势和临床效果,以便为临床手术决策提供可行的参考依据。

直连绳索取心钻杆分区热处理技术研究

为了提高绳索取心钻杆的性能,对直连绳索取心钻杆的受力情况、结构特点以及传统处理工艺进行分析,提出了分区热处理的工艺。通过对两端进行热加工处理,使钻杆中间管体区域和两端热处理螺纹区域性能出现差异,提高两端综合强度的同时改善螺纹部分的受力状态,可使钻杆柱既具有高强度又兼具柔性,大幅提高钻杆机械性能以及耐磨性。其中调质硬度HRC33~38能在保证管体延伸率与正火、回火基本一致的情况下,强度提高37.7%,硬度提高40%,抗冲击性提高46.7%。调质硬度HRC38~42时,材料的耐磨性提高9.1%。更适合全液压钻机施工及深孔钻进,为钻探施工提供了钻机、钻杆配套性的优选方案。

近距离煤层群联合开采火区“三位一体”治理技术

针对近距离煤层群开采期间的自然发火防治难题,以新维煤矿2110、3108工作面断层区域火点处置为例,通过实验研究与现场实践相结合的手段,开展隐蔽火点的探测与综合治理技术研究。3号煤层自然发火模拟实验结果表明:CO、C_(2)H_(4)体积分数与煤温呈二次函数关系,可用于煤层自然发火预测预报;氧气体积分数的降低可以有效抑制煤自燃氧化进程,氧气体积分数为7%时最为明显,因此将其设为3号煤层自然发火的临界氧气体积分数。通过自燃隐患分析结合钻孔探查划定了3110轨道巷以西长80 m、宽10 m的F9断层区域为自然发火隐患区域,并提出以注浆降温为先导,以注胶堵漏为核心,以注氮阻爆为手段的液-胶-气“三位一体”的火区治理思路,累计向隐患区域注浆180 t、注胶504 m^(3),2110工作面采空区注氮流量保持在810 m^(3)/h,实现了火区的有效治理,保障了2个工作面的顺利启封与安全回采。

基于回转下沉量的导水裂隙带发育高度预测

导水裂隙带发育高度是煤矿顶板防治水的重要参数。通过分析采动覆岩破坏过程,将裂隙带内岩层失稳破坏划分为产生垂向裂隙、形成砌体结构和回转失稳3个阶段;建立了岩层产生垂向裂隙及回转下沉的力学模型,在此基础上,提出了分析岩石产生垂向裂隙与回转失稳的最大下沉量来判断岩层破坏情况,回转下沉量值处于这2个阶段之间的岩层形成稳定的砌体结构,得出了计算导水裂隙带高度的新方法。以营盘壕2201工作面为例,采用理论方法和数值模拟对导水裂隙带高度进行预测,通过与现场实测数据的对比,理论计算(123.3 m)和数值模拟结果 (132 m)与实测数据(115.5 m)接近,验证了所提方法的合理性。

印染集聚提升园区废水集中处理设施设计与运行

浙江某印染集聚提升园区废水集中处理设施建设规模30000 m^(3)/d,针对园区废水特点,采用主体工艺为“调节池+冷却系统+反应初沉池+厌氧水解池+A/O生化池+二沉池+高效沉淀池”的组合工艺对其进行处理。运行结果表明,该工艺稳定高效,当进水平均COD、BOD5、总锑分别为1370、360、1.17 mg/L时,处理后出水平均COD、BOD5、总锑分别降至88、7.4、0.049 mg/L,对应去除率分别达到94%、98%、96%,出水符合《纺织染整工业水污染物排放标准》(GB 4287—2012)表2间接排放要求。工程采用了混凝药剂强化的初沉工艺,实现了有效的废水碳捕集,间接对外输出能源,有利于减少碳排放,其主要处理单元采用集约化组合及深池型设计,节省占地,可为占地受限型废水处理厂的建设提供参考。

全地下式污水处理厂除臭系统设计探讨

随着全地下污水厂的兴起,全地下污水厂具有全封闭性的特点,对全地下污水处理厂进行除臭显得尤为重要。结合上海嘉定南翔污水处理厂除臭系统的设计,分别从全地下污水处理厂除臭分区划分、除臭工艺选择、生物滤池原理、设计参数选取及计算方式、除臭风管布置等几个方面进行介绍,以期为同类型的全地下污水处理厂提供设计参考案例。其中重点分析了全地下污水厂中除臭分区的划分方式、除臭工艺的选择和设计计算。上海嘉定南翔污水厂进行生物除臭的总风量为96000 m^(3)/h,离子除臭风量为11000 m^(3)/h。

陡坡区加筋土挡墙基底不良地质处理

以黑山南北高速公路项目中的一段隧道间陡坡区加筋土挡墙支挡路基为例,对挡墙基底不良地质情况及可能产生的路基侧向滑移风险进行描述,并就拟采用的四种处理方案进行比选,对其优劣势和经济性进行探讨,为后续类似项目可能出现的情况提供经验。

莲花瑶乡隧道断层破碎带初期支护变形成因及治理措施

桂钟高速公路莲花瑶乡隧道围岩为风化砂岩,节理裂隙极发育,岩质软,岩体破碎,地质条件极差。施工过程中多次出现溜渣、掌子面塌方、初期支护变形、地表开裂等问题,工程进度及施工安全受均到严重影响及挑战。以该隧道为依托,研究探讨了断层破碎带坍塌机理、监控量测、初期支护加固、初期支护变形临时加固及开挖工法等处治措施。

采煤工作面过断层破碎带的治理技术实践

在煤矿井工开采中,需在矿井下布置采煤工作面,采煤工作面遇断层破碎带区域往往顶板比较破碎,对煤矿开采工作造成影响,且会因顶板坍塌引发安全事故,对采煤工作人员生命安全造成危害。针对采煤工作面顶板围岩控制的问题,研究选取大同煤矿22103采煤工作面,围绕采煤工作面过断层破碎带治理技术进行分析探讨,基于注浆加固技术机理与新型注浆材料的性能,实现对采煤工作面顶板围岩的有效控制,使采煤工作面能够安全快速通过断层破碎带,为煤矿开采工作合理、规范地开展提供科学依据与参考。

隧道拱顶塌腔处理及防治方法分析

介绍省道S207线闽浙界至寿宁下党段公路工程杨溪头2号隧道工程拱顶塌腔处理的施工实践,针对隧道围岩节理裂隙发育状况及不良地质水文情况引发的拱顶塌腔,着重分析拱顶塌腔发生原因、拱顶塌腔防治办法,以及塌腔处理的系列针对性举措等,并结合地质超前预报、围岩监控量测等手段,实时动态分析围岩支护,跟踪支护效果,以有效预防隧道塌方。

固溶时效对6061铝合金焊接接头组织和性能的影响

采用脉冲钨极氩弧焊工艺对6 mm厚的6061-T6铝合金板进行焊接试验,对焊态接头和焊后进行530℃×6 h固溶+180℃×3 h人工时效处理的接头组织及性能进行分析。结果表明,焊态接头热影响区的强度显著降低,显微硬度最低为48 HV;固溶时效处理可强化焊接接头,热影响区显微硬度达到80 HV以上。拉伸断口形貌均为韧性断裂特征,与焊态接头相比,固溶时效处理后接头断口的韧窝要浅且细小,塑性变差。固溶时效处理改善了接头热影响区强化相的组织形态,由平衡相β-Mg 2Si转变成与基体保持共格或半共格的β″相或β′相,使其机械性能得以恢复。