松嫩平原羊草草地土壤-植物间铁的动态研究

羊草草地土壤-植物间营养元素Fe的动态研究结果表明,土壤中全铁和有效铁含量均较低,羊草中Fe含量比较丰富．在生长季各时期,全铁和有效铁含量在土壤剖面分布上从上向下呈下降趋势,有效铁与有机质含量呈显著正相关,而与pH值呈显著负相关．全铁各月平均含量变化在生长季呈“V”型曲线,7月含量最低;有效铁平均含量从5～8月与全铁相似,8月后则逐渐减少．羊草各器官及枯落物Fe含量有很大变化,总的趋势是根>根茎>叶>枯落物>茎;羊草叶、茎的Fe含量在生长季中为波动型下降曲线,根茎、根及枯落物的Fe含量在生长季中为“V”型曲线．A层土壤富集有效铁的能力稍强．土壤中Fe活性平均为0．640％。从5月至8月逐渐升高,8月后逐渐下降,10月份最低．地下部的Fe向地上部的转移强度为5～7月下降,8月升高,随后又下降．地上部Fe向枯落物的转移强度平均为105．0％,与地下部Fe向地上部转移强度呈显著负相关。     

Stool antigen assay to screen H. pylori infection and to assess the success of 3-Day and 7-Day eradication therapy in the patients with partial gastrectomy

Background. Even after partial gastrectomy, Helicobacter pylori may persist in the residual stomach but be less abundant in the bacterial load. H. pylori stool antigen is a reliable noninvasive tool to detect H. pylori infection in patients without gastrectomy. We thus test whether [ 1 ] the course of H. pylori eradication therapy could be diminished [ 2 ]; stool antigen can effectively detect H. pylori infection for the patients with gastrectomy. Methods. One hundred and eight patients who had undergone partial gastrectomy were enrolled to receive panendoscopy and provided stool samples for H. pylori stool antigen within 3 days after endoscopy. The H. pylori‐infected patients were then randomized to receive either a 3‐ or 7‐day triple therapy for H. pylori eradication. Six weeks later, to evaluate the success of H. pylori eradication, patients received a follow‐up endoscopy and again provided stool samples for H. pylori stool antigen. Results. Seventy out of 108 patients, proven to have H. pylori infection, were evenly randomized into 3‐day and 7‐day therapy groups. The H. pylori eradication rates were similar between the 3‐day and 7‐day triple therapy (90.9 vs. 93.8%, p > .05). Before therapy, the H. pylori stool antigen was 93% sensitive and 100% specific to detect H. pylori. After therapy, H. pylori stool antigen remain 100% sensitive and 88.3% specific to detect the failure of eradication therapy. Conclusion. H. pylori stool antigen is a highly reliable tool to screen H. pylori infection before therapy and to assess the success of eradication therapy in partial gastrectomy patients. To eradicate H. pylori infection for patients with partial gastrectomy, the duration of triple therapy can be shortened.     

Effects of matriconditioning on onion seed germination, seedling emergence and associated physical and metabolic events

The effect of matriconditioning, the physiological presowing seed technique, using Micro-Cel E on Allium cepa L. cv. Czerniakowska seed quality was studied. Several ratios of seeds, carrier, water and time of priming were tested. The most effective treatment for improving onion seed germination at most tested temperatures was priming to a ratio of 2 g seed:1 g Micro-Cel:3 g water for 5 days in light at 15 °C. Matriconditioning greatly improved the germination and emergence percentage, seedling fresh and dry weight and reduced electrolyte leakage compared to that of untreated seeds; this beneficial effect was especially evident at suboptimal temperatures. Matriconditioning improved the germinability of aged seeds, the effect being more pronounced in the more aged seeds. No significant differences in ethylene production by primed and non-primed seeds were observed in the absence of its precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), but its presence during imbibition caused an increase in ethylene production; an enhanced activity of in vivo ACC oxidase in Allium cepa matriconditioned seeds in comparison to untreated seeds, indicates that the endogenous level of ACC is a limiting factor of ethylene production. Likewise, the activity of ACC oxidase isolated from matriconditioned seeds was higher than that from untreated seeds. Higher endo--mannanase and total dehydrogenase activities were observed in primed air-dried seeds in comparing to non-primed seeds.     

Membrane oxidation assay--a novel lipoxygenase-based evaluation of membrane oxidizability

A membrane oxidation assay is presented which uses isolated erythrocyte membranes ("ghosts") and lipoxygenase as a selective catalyst for the transfer of oxygen to cis - cis -1,4-pentadiene-moieties. The latter are, for instance, present in linoleic and arachidonic acids, both of which are integral parts of membranes. These non-conjugated double bonds represent energetically favorable sites for oxidative attack and therefore, may be rearranged and partially consumed during oxidative stress. Consequently, the measurement of oxygen consumption in the course of the lipoxygenase-mediated oxidation provides a tool for the quick and reliable determination of such double bonds. Significant inter-individual differences have been noted in 11 subjects, which also correlate to the total radical antioxidant parameter (TRAP) values obtained. This assay will be helpful in the assessment of oxidizable structures in erythrocyte membranes that may be diminished as a consequence of oxidative damage suffered by an individual. In conclusion, a simple and rapid assay for the assessment of the oxidizability of erythrocyte membranes is presented complementing the TRAP assay for plasma antioxidative status.     

Fluorescence imaging with two-photon evanescent wave excitation

We demonstrate broad-field, non-scanning, two-photon excitation fluorescence (2PEF) close to a glass/cell interface by total internal reflection of a femtosecond-pulsed infrared laser beam. We exploit the quadratic intensity dependence of 2PEF to provide non-linear evanescent wave (EW) excitation in a well-defined sample volume and to eliminate scattered background excitation. A simple model is shown to describe the resulting 2PEF intensity and to predict the effective excitation volume in terms of easily measurable beam, objective and interface properties. We demonstrate non-linear evanescent wave excitation at 860 nm of acridine orange-labelled secretory granules in live chromaffin cells, and excitation at 900 nm of TRITC-phalloidin-actin/GPI-GFP double-labelled fibroblasts. The confined excitation volume and the possibility of simultaneous multi-colour excitation of several fluorophores make EW 2PEF particularly advantageous for quantitative microscopy, imaging biochemistry inside live cells, or biosensing and screening applications in miniature high-density multi-well plates.Abbreviations 1PEF one-photon excited fluorescence - 2PEF two-photon excited fluorescence - APD avalanche photo diode - CHO Chinese hamster ovary - DMEM Dulbecco's modified Eagle's medium - EGFP enhanced green fluorescent protein - EW evanescent wave - FCS fetal calf serum - GPI glycosylphosphatidylinositol - TIR total internal reflectionThis paper is dedicated to the memory of Prof. Horst Harreis (1940–2002)     

Tracking chromaffin granules on their way through the actin cortex

Quantitative time-lapse evanescent-wave imaging of individual fluorescently labelled chromaffin granules was used for kinetic analysis of granule trafficking through a ∼300-nm (1/e²) optical section beneath the plasma membrane. The mean squared displacement (MSD) was used to estimate the three-dimensional diffusion coefficient (D ⁽³⁾). We calculated the granules' speed, frame-to-frame displacement and direction and their autocorrelation to identify different stages of approach to the membrane. D ⁽³⁾ was about 10,000 times lower than expected for free diffusion. Granules located ∼60 nm beneath the plasma membrane moved on random tracks (D ⁽³⁾≈10⁻¹⁰ cm² s⁻¹) with several reversals in direction before they approached their docking site at angles larger than 45^∘. Docking was observed as a loss of vesicle mobility by two orders of magnitude within <100 ms. For longer observation times the MSD saturated, as if the granules' movement was confined to a volume only slightly larger than the granule. Rarely, the local random motion was superimposed with a directed movement in a plane beneath the membrane. Stimulation of exocytosis selectively depleted the immobile, near-membrane granule population and caused a recruitment of distant granules to sites at the plasma membrane. Their absolute mobility levels were not significantly altered. Application of latrunculin or jasplakinolide to change F-actin polymerisation caused a change in D ⁽³⁾ of the mobile granule population as well as a reduction of the rate of release, suggesting that granule mobility is constrained by the filamentous actin meshwork and that stimulation-dependent changes in actin viscosity propel granules through the actin cortex. Received: 18 November 1999 / Revised version: 26 January 2000 / Accepted: 2 February 2000     

Contamination of a dredged material disposal site La Rochelle Bay,France .The use of the acetylcholinesterase activity of Mytilus edulis L. as a biomarker of pesticides: the need for a critical approach

A single aspect of the toxic impact of a dredged material disposal site located near a mussel-farming zone was followed for eight months. Acetylcholinesterase activity (AChE) of Mytilus edulis was investigated as a biomarker for possible contamination by neurotoxic compounds (carbamates and/or organophosphorous pesticides). Our observations showed that the enzymatic activities (including AChE) of these harbour mussels were decreased in sites directly and indirectly influenced (according to hydrodynamic conditions) by the dumping of dredged sediments, suggesting possible contamination by pesticides. The strong correlations observed between AChE activity and growth parameters (length and weight) seems to show, however, that the enzyme activity is also indirectly controlled through growth restriction, which may imply limitation of the development of the nervous system in juveniles. The concentration of total proteins, as well as the spawning process also seem to disturb the assessment of AChE activity. These field observations clearly indicate that the use of this enzyme activity as a biomarker should proceed with caution. For example, the seasonal variability of such activity should be taken into account in a biomonitoring programme.     

腹腔镜与开腹全系膜切除术治疗118 例直肠癌疗效研究

目的：探讨开腹与腹腔镜全系膜切除术(TME)治疗直肠癌的疗效及安全性。方法：选择本院收治的直肠癌患者118 例,随机 分为对照组和观察组,各为59 例。对照组行开腹直肠全系膜切除术,观察组行腔镜直肠全系膜切除根治术。比较两组术中效果、 淋巴结清扫效果、术后肠道功能恢复、手术风险和随访结果。结果：两组手术时间和淋巴结清扫数目无显著差异(P>0.05);观察组 切口长度和术中出血量显著少于对照组(P<0.05),肛门排气、肠胃功能恢复和总住院时间均显著短于对照组(P<0.05);观察组总并 发症率为5.08%,显著低于对照16.95%(P<0.05);观察组保肛率达到81.36%,显著高于对照组66.10%(P<0.05);两组2 年复发率和 转移率间差异无统计学意义(P>0.05)。结论：腹腔镜直肠癌TME 创伤小,根治率高,术后恢复快,并发症少,远期疗效与开腹手术 相近,综合疗效优于开腹根治术。     

全髋关节置换术与双极人工股骨头置换术治疗老年股骨颈骨折的临床疗效

目的：探讨全髋关节置换术（THA）与双极人工股骨头置换术（BHA）治疗老年股骨颈骨折的临床疗效。方法：选择2013 年7 月-2015 年3 月我院收治的老年股骨颈骨折患者90 例,根据手术方法不同将患者分为全髋关节置换组（THA 组）和双极人工股 骨头置换组（BHA 组）,每组45 例。观察并比较两组患者的手术时间、术中出血量、住院时间、术后并发症的发生率及手术效果。结 果：两组患者的手术时间、术中出血量及住院时间比较,差异无统计学意义（P>0.05）;THA 组并发症的发生率明显低于BHA 组, 差异具有统计学意义（P<0.05）;术后1 年,两组手术优良率比较,差异无统计学意义（P>0.05）;术后两年及三年,THA 组手术优良 率明显高于BHA 组,差异具有统计学意义（P<0.05）。结论：THA和BHA 治疗老年股骨颈骨折均具有良好的临床疗效,但THA具 有更好的远期疗效,而且术后并发症的发生率较低。     

人工全髋关节置换治疗成人髋关节发育不良并骨性关节炎的临床分析

目的:探讨人工全髋关节置换治疗成人髋关节发育不良并骨性关节炎的临床疗效。方法:对2009年7月至2012年7月入住我院的60例成人髋关节发育不良并骨性关节炎患者行人工全髋关节置换术治疗。分析治疗优良率、手术前后不同Crowe分型Harris评分、手术前后行走及疼痛情况、手术前后生活质量。结果:1根据Harris评分,本组治疗优良率91.67%(55/60);2术后各Crowe分型患者Harris评分均显著高于术前,差异均具有统计学意义(P<0.05);3本组术前自行行走及辅助行走例数分别为23及37例,术后分别为39例及21例;术前疼痛情况:无、轻、中及重度疼痛例数分别为1例、6例、22例及31例,术后分别为18例、28例、12及2例,手术前后行走情况及疼痛情况差异均具有统计学意义(P<0.05);4根据SF-36生活质量评价标准,术后生活质量评分为(142.16±10.32)分,显著高于术前(115.24±7.34)分,差异具有统计学意义(P<0.05)。结论:人工全髋关节置换治疗成人髋关节发育不良并骨性关节炎的临床疗效显著,术后患者髋关节功能及生活质量明显改善,应在临床上加以推广。