间伐套种对杉木人工林生长、干形形质和材种结构的影响

[目的]分析间伐套种措施对杉木林木生长形质性状、空间利用能力和林分产量的影响,明确林分经营方向,为杉木人工纯林改造提供科学依据。[方法]对安徽省青阳县23 a林龄的杉木人工林设置3种间伐强度(Ⅰ:47%;Ⅱ:56%;Ⅲ:65%),林下套种2种阔叶树浙江楠(Phoebe chekiangensis)和檫木(Sassa-fras tzumu),并以未间伐套种的杉木人工纯林为对照(CK:0%间伐,保留密度1740株·hm^(-2)),探究不同间伐与阔叶树套种处理对杉木人工林的影响,并通过主成分分析法综合评价间伐与阔叶树套种对杉木生长的影响。[结果](1)间伐与阔叶树套种促进了杉木生长,Ⅲ处理的胸径、树高、单木材积、用材出材率均为最大,分别比CK增加了32.07%、21.60%、83.33%、6.77%(P<0.05);但高径比和胸高形数、小条木、小径材、薪材和废材的出材率均低于CK,分别降低了8.64%、3.70%、90.88%、41.47%、54.50%、5.71%。(2)间伐与阔叶树套种改变了杉木的空间利用能力,冠幅、冠长、冠长率、冠形率、树冠表面积和树冠体积均显著高于CK(P<0.05),分别提高了12.16%~31.00%、55.58%~61.24%、30.00%~40.00%、16.11%~44.94%、67.17%~95.86%、84.74%~146.63%。(3)间伐套种处理可以有效改善杉木人工林的生长特征,各处理的综合得分由高到低依次为Ⅲ(1.186)>Ⅱ(1.092)>Ⅰ(0.671)>CK(-0.709)。[结论]杉木人工林经营若以快速提升杉木人工林生长特征为目的,本研究中Ⅲ处理(65%间伐+套种阔叶树)是最佳处理措施。

青冈栎次生林土壤活性有机碳对间伐强度的响应

[目的]探索不同间伐强度对青冈栎次生林土壤活性有机碳的响应。[方法]以湖南省天心阁林场青冈栎次生林为研究对象,于2018年设置4种间伐强度(对照:0%;弱度间伐:15%;中度间伐:30%;强度间伐:50%),探讨不同间伐强度下4种土壤活性有机碳(土壤微生物量碳、可溶性有机碳、颗粒有机碳和易氧化有机碳)含量变化及其在总有机碳中的分配比例。[结果](1)与对照样地相比,中度间伐和强度间伐显著提高了土壤总有机碳含量,弱度间伐降低了土壤总有机碳含量;(2)间伐提高了土壤微生物量碳的含量,降低了可溶性有机碳的含量,土壤颗粒有机碳和易氧化有机碳含量在不同间伐处理下的变化趋势与总有机碳一致;(3)不同间伐强度下土壤微生物量碳、可溶性有机碳、颗粒有机碳和易氧化有机碳的分配比例分别为:0.23%~0.54%、0.40%~0.78%、16.54%~47.30%和6.46%~14.29%,强度间伐显著提高了微生物量碳、颗粒有机碳和易氧化有机碳分配比例,降低了可溶性有机碳的分配比例,表明间伐提高了不稳定碳的比例,且颗粒有机碳对间伐处理更敏感;(4)相关性分析表明,土壤总有机碳与各活性有机碳组分间呈极显著正相关,且活性有机碳与土壤含水量和总氮含量呈正相关;土壤活性组分碳间转化依赖于总有机碳量的变化,且在一定的水分和氮素条件下易发生分解转变。[结论]不同间伐处理对土壤有机碳及其活性组分的含量有显著影响,强度间伐显著提高土壤有机碳及其活性组分的含量,加快土壤中的碳素循环。

3D deformation effect and optimal excavated design of surface mine

The three-dimensional (3D) deformation effect of the slope engineering underthe step-by-step excavation for the Antaibao surface mine was analyzed using the FLAG^3Dtechnique. An optimal excavated scheme with a relatively steeper slope angle of 47^(。) instead of 30^(。) was successfully implemented at the west wall in the geological section73200 of the mine area, where the 3D effect of the nonlinear large deformation of theslope was taken into account. Based on the above research conclusion, put forward thecountermeasures of shortening mining length, excavating by different regions, timely footbackfilling to protect the excavated slope, and monitoring and feedback adjustment bystudying the nonlinear effect. The results show that these countermeasures are effective incontrolling maximum deformation and increasing the stability of the slope.

Smad4、Caveolin-1在肺腺癌中的表达及与预后的关系

目的探讨Smad4、Caveolin-1蛋白在肺腺癌中的表达,分析它们与临床病理因素间的关系及对预后的影响,为分子诊断、预后评估及临床治疗积累数据。方法采用免疫组织化学SP法分别检测130例肺腺癌及癌周正常肺组织中Smad4、Caveolin-1蛋白的表达。结果(1)Smad4、Caveolin-1蛋白在癌周正常肺组织中的表达率分别为90.77%、96.15%,显著高于癌组织中66.15%、41.54%,差异有统计学意义(P<0.05)。(2)腺癌组织中Smad4、Caveolin-1蛋白的表达均与患者性别、年龄、肿块发生部位、有无吸烟及肿块大小无关(P均>0.05),但是与有无淋巴结转移、肿瘤分化程度及TNM分期相关(P均<0.05)。(3)Smad4、Caveolin-1两蛋白在腺癌组织中的表达呈正相关(P<0.05)。(4)Smad4阳性表达组的术后生存时间显著高于阴性表达组,差异有统计学意义(P<0.05),与之相反Caveolin-1阴性表达组的术后生存时间显著高于阳性表达组,差异有统计学意义(P<0.05)。结论Smad4、Caveolin-1蛋白的表达缺失或升高,促进了肿瘤的侵袭性生长和临床进展,提示预后不良,可作为肺腺癌潜在的分子诊断和预后评价指标。

穿越采空区场地的高铁线路优化分析

以穿越煤矿采空区某高铁线路为研究对象,经过对采空区场地现场勘查、物探测试、钻探验证,确定煤矿采空区的边界范围。基于采空区地表PS-InSAR沉降分析、采空区场地剩余变形预测分析以及技术经济比较,对拟选用的3个线路方案进行优化,确定出最终选线方案,并提出建议和措施,为类似工程实践提供借鉴和参考。

巨厚砂砾岩储层X形水力裂缝的形成——以中国渤海湾盆地储层为例

中国渤海湾盆地致密砂砾岩储层广泛发育,它们通常为深埋巨厚储层,其有效开发需依赖水力压裂技术。为了研究砂砾岩储层水力裂缝的扩展特征,首先,探究了此地砂砾岩储层的地质条件,包括地层纵向分布规律和岩性特征;然后,通过地面微地震系统对该地区盐222区块几口井的压裂过程进行了监测。结果表明,目标井大多数地层压裂后均形成了X形水力裂缝。本文将储层形成X形水力裂缝的主要原因归于(1)储层非均质性和(2)两条近距离同向扩展的水力裂缝的应力阴影效应,并通过数值模拟等方法对其进行了详细分析和验证。本文的研究成果和结论可为巨厚砂砾岩储层水力裂缝扩展特征的深入研究提供参考依据。

Dysfunction of endothelial NO system originated from homocysteine-induced aberrant methylation pattern in promoter region of DDAH2 gene

Background Hyperhomocysteinemia （HHcy）-mediated dysfunction of endothelial NO system is an important mechanism for atherosclerotic pathogenesis. Dimethylarginine dimethylaminohydrolase （DDAH） is the key enzyme for degrading asymmetric dimethylarginine （ADMA）, which is an endogenous inhibitor of endothelial nitric oxide （NO） synthase （eNOS）. This study was designed to investigate whether the dysfunction of endothelial NO system originates from HHcy-mediated aberrant methylation modification in promotor region of DDAH2 gene. Methods Human umbilical vein endothelial cells （HUVECs） were cultured to the third generation and treated with homocysteine （Hcy） at different concentrations （0, 10, 30, 100, and 300 μmol/L） for 72 hours. The methylation pattern in promoter region CpG island of DDAH2 gene was analyzed by nested methylation-specific PCR （nMSP）. The mRNA expression of eNOS gene and DDAH2 gene was detected by semi-quantitative RT-PCR. The activity of DDAH2 and eNOS in cells, and the concentrations of ADMA and NO in culture medium were assayed respectively. Results Mild increased concentration of Hcy （10 and 30 μmol/L） induced hypomethylation, while high concentration of Hcy （100 and 300 μmol/L） induced hypermethylation in the promoter CpG island of DDAH2 gene. The mRNA expression of DDAH2 increased in mild enhanced concentration of Hcy, and decreased in high concentration of Hcy correspondingly. The inhibition of DDAH2 activity, the increase of ADMA concentration, the reduction of eNOS activity and the decrease of NO production were all consistently relevant to the alteration of Hcy concentration. Conclusion The increased concentration of Hcy induced aberrant methylation pattern in promotor region of DDAH2 gene and the successive alterations in DDAH/ADMA/NOS/NO pathway, which showed highly relevant and dose-effect relationship. The results suggested that the dysfunction of endothelial NO system induced by HHcy could be partially originated from Hcy-mediated aberrant methylation in DDAH2 gene.

Age-related changes of the redox state of glutathione in plasma

Glutathione （GSH） is the principal non-protein thiol responsible for maintaining intracellular redox status and protecting cells against oxidative/ nitrosative stresses. In the biological system, some GSH is bound to proteins, and others exist freely, including the reduced glutathione and oxidized glutathione （GSSG）. Generally it is in a steady redox state for GSH/GSSG couple to participate in a variety of physiological functions. Earlier studies showed that chemically induced oxidative stress in vivo in rats resulted in increased GSSG and decreased GSH/GSSG ratio. The impairment of the glutathione homeostasis represents an indicator of tissue oxidative stresss status in human subjects.

Elevated peroxidative glutathione redox status in atherosclerotic patients with increased thickness of carotid intima media

Background Atherosclerosis is a chronic inflammatory disease. Accumulated evidences suggest a deep involvement of oxidative damage in the development of atherosclerosis, but little is discussed over the relationship between plasma glutathione redox status as the most important intrinsic antioxidant defensive mechanism and the atherosclerosis. Methods A total of 132 patients suspected with atherosclerosis were assigned to three groups by high frequency ultrasonic examination of the carotid artery. With the thickness of intima of the carotid artery as an index of degree of atherosclerosis progression, 56 were included in plaque-forming group （A）, 42 in carotid artery intima-thickening group （B）, and 34 in normal carotid artery intima-thickness group （C）. All patients were subjected to the measurement of plasma glutathione （GSH） （reduced form GSH and oxidized form GSSG）, nicotinamide adenine dinucleotide phosphate （NADP） （reduced form NADPH and oxidized form NADP^＋）, oxidized low density lipoprotein （oxLDL）, and malondialdehyde （MDA） The GSH/GSSG and NADPH/NADP^＋ redox potentials were calculated according to the Nernst equation, and their correlation with intima thickness and oxLDL was analyzed. Results With the thickening of artery intima （from group C to A）, GSH concentration and the ratio of GSH/GSSG gradually reduced, and GSSG and GSH/GSSG redox potential gradually increased （more positive） （P 〈0.05）. The NADPH and NADPH/NADP^＋ redox status also showed similar but milder changes. The products of oxidative stress oxLDL and MDA increased significantly along with the thickening of artery intima （P 〈0.05）. The analysis of the relationship between GSH/GSSG redox potential, intima thickness, and oxLDL showed positive correlations （P 〈0.05）. The plasma GSH/GSSG redox status was positively correlated with the intima thickness of the carotid artery and the oxidized injury of LDL. The redox status shifted to oxidizing direction along with the intima thickening and plaque-forming. Conclusion Elevated peroxidative glutathione redox status was deeply implicated in atherosclerosis progressing, and it may be a sensitive and reliable index for monitoring oxidative status in atherosclerosis.

髋部骨折病例特征及术后转归情况

目的探究髋部骨折病例特征及术后转归情况。方法以2017年1月1日至2020年12月31日哈尔滨市某医院诊治的髋部骨折患者为研究对象,收集髋部骨折患者的基本信息及临床资料并进行出院后1年的随访跟踪调查。采用描述性分析方法对患者特征及术后1年病死情况进行分析,并采用单、多因素分析方法对术后1年病死影响因素进行分析。结果本研究共纳入2342例髋部骨折患者资料进行分析,其中2017年485例(20.71%),2018年582例(24.85%),2019年628例(26.81%),2020年647例(27.63%),收治病例数呈逐年上升趋势。男女性别比例为1∶1.53;年龄33~90岁,其中以70~79岁年龄段占比最高(26.35%);骨折类型以股骨颈骨折占比较高(48.96%),其次为股骨转子间骨折(45.99%),股骨头骨折占比最低(5.04%);发病人数最多的季节为冬季(27.67%)。4年间不同年龄、治疗方法、辅助中药治疗患者分布差异有统计学意义(P<0.05或P<0.01),4年间不同性别、骨折类型、内科合并症、发病季节患者分布差异无统计学意义(均P>0.05)。完成髋部骨折患者出院后1年随访共2331例,1年病死率为2.66%(62/2331)。多因素分析结果显示,年龄增长(OR=2.063)、非手术治疗(OR=1.730)、白蛋白水平<35 g/L(OR=2.048)及有内科合并症(OR=2.330)是髋部骨折患者出院后1年病死的危险因素。结论髋部骨折病例多见于女性、≥60岁人群,股骨颈骨折是常见类型,多在冬季发病,且不同特征的患者临床转归存在明显差异。