首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   216篇
  免费   10篇
  国内免费   2篇
  2023年   4篇
  2022年   7篇
  2021年   17篇
  2020年   15篇
  2019年   10篇
  2018年   18篇
  2017年   2篇
  2016年   12篇
  2015年   12篇
  2014年   14篇
  2013年   16篇
  2012年   14篇
  2011年   15篇
  2010年   9篇
  2009年   6篇
  2008年   8篇
  2007年   9篇
  2006年   11篇
  2005年   2篇
  2004年   3篇
  2003年   5篇
  2002年   5篇
  2001年   2篇
  1999年   3篇
  1993年   1篇
  1992年   2篇
  1991年   1篇
  1985年   1篇
  1979年   2篇
  1976年   1篇
  1969年   1篇
排序方式: 共有228条查询结果,搜索用时 15 毫秒
201.
Soilborne fungal phytopathogens cause significant losses in many economically important crops and vegetables. The only way to control these devastating pathogens is by using higher doses of fungicides which not only increase the cost of production but also cause significant damage to the environment. Therefore alternate control measures are always looked for. In the present study, an antagonistic strain was isolated from the soil of the pepper fields around the seashore of Jellanamdo, South Korea and identified as Paenibacillus ehimensis KWN38 based on 16S rRNA sequencing. The strain showed high antifungal activity against six tested fungal pathogens belonging to various taxonomic groups on dual culture plates. Furthermore, the strain produced volatile antimicrobial compounds which had strong fungal growth inhibitory effect. The strain also showed high chitinase, cellulase, glucanase and protease activities. The hyphal morphologies of Rhizoctonia solani AG-1 (IA), Fusarium oxysporum f.sp. lycopersici and Phytophthora capsici were significantly destroyed by the crude enzymes and butanol extract from the culture supernatant and the affected hyphae showed abnormal bending, tip curling, and irregular branching. Hence, Paenibacillus ehimensis KWN38 is considered as a potential biocontrol agent of the soil-borne fungi causing plant diseases which is an important perspective of the present study.  相似文献   
202.
In the present study, butachlor (5, 10, 20, 40 and 80 ppm) induced toxicity in Nostoc muscorum and their degradation was evaluated. The dose of butachlor dependent decreased in the cell survival and growth of N. muscorum was noticed. Scanning electron microscopy revealed the adverse impact on the cell size and shapes. Low concentrations of butachlor (10 and 20 ppm) induced the over expression of a polypeptides of 31.0 K Da and 42.7 K Da, respectively which could be responsible for developing resistance in the organism up to certain level. Further, the degradation product of butachlor as a result of metabolic activities of N. muscorum, identified by GC-MS analysis includes phenols and benzene dicarboxylic acid indicating the utilization of herbicide during active growth.  相似文献   
203.
Dysbalance in reactive oxygen/nitrogen species is involved in the pathogenesis of cerebral ischemia/reperfusion injury (IRI). Ginkgo biloba extract (Egb 761) pre-treatment was used to observe potential antioxidant/neuroprotective effect after global ischemia/reperfusion. Egb 761 significantly decreased the level of lipoperoxidation (LPO) in rat forebrain total membrane fraction (homogenate) induced by in vitro oxidative stress (Fe2++H2O2). In animals subjected to four-vessel global ischemia for 15 min and 2–24 h reperfusion the EGb pretreatment slightly decreased LPO in forebrain homogenate. However, as detected in EGb treated group, the LPO-induced lysine conjugates are attenuated in comparison to non-treated IRI animals. EGb significantly improved parameters which indicate forebrain protein oxidative damage after IRI. The intensity of tryptophane fluorescence was increased by the 18.2% comparing to non-treated IRI group and bityrosine fluorescence was significantly decreased in ischemic (21%) and 24 h reperfused (15.9%) group in comparison non-treated IRI group. In addition, the level of total free SH- groups in pre-treated animals was significantly higher comparing to non-treated animals. Our results indicate that extract of EGb 761 has potent antioxidant activity and could play a role to attenuate the IRI-induced oxidative protein modification and lipoperoxidation in the neuroprotective process.  相似文献   
204.
Separation and isolation of the two main compounds suaveolol and methyl suaveolate from leaves of chichinguaste (Hyptis suaveolens Poit., Lamiaceae) could be achieved by means of repeated column chromatography and repeated preparative thin layer chromatography. Their chemical structures were approved by MS, 1H NMR, 13C NMR and 2D-NMR experiments. The anti-inflammatory activity of the two compounds was tested for the first time as inhibition of croton oil-induced dermatitis of the mouse ear. Suaveolol and methyl suaveolate showed nearly the same dose-dependent topical anti-inflammatory activity, only two to three times lower than that of the reference drug indomethacin. The anti-inflammatory properties of these compounds could contribute to the antiphlogistic activity of extracts of Hyptis species and confirm the rational use of Hyptis suaveolens extracts in dermatological diseases.  相似文献   
205.
A series of N1-nicotinoyl-3- (4'-hydroxy-3'-methyl phenyl)-5-(substituted phenyl)-2-pyrazolines were synthesized by the reaction between isoniazid (INH) and chalcones and were tested for their antimycobacterial activity in vitro against Mycobacterium tuberculosis H37Rv (MTB) and INH-resistant M. tuberculosis (INHR-MTB) using the agar dilution method. Among the synthesized compounds, compound (i) N1-nicotinyl-3-(4'-hydroxy-3'-methyl phenyl)-5-(1'-chlorophenyl)-2-pyrazoline was found to be the most active agent against MTB and INHR-MTB, with minimum inhibitory concentration of 0.26 microm. When compared to INH-compound i was found to be 2.8- and 43.7-fold more active against MTB and INHR-MTB, respectively.  相似文献   
206.
Dependence of plasma total homocysteine (tHcy) and DNA damage profiles on melanodialdehyde (MDA), oxidative stress, liver function tests (LFT), and lipids was studied in non-obese and obese subjects in the Pakistani population. Development of obesity is influenced by both genetic, biochemical and environmental factors. Plasma homocysteine (Hcy) and DNA damage profiles play a pivotal role in its progression. We studied 160 obesity patients and 160 lean subjects. Leukocytes were evaluated for DNA damage by comet assay and blood plasma for biochemical properties using commercial kits. Plasma Hcy level and DNA damage were strongly correlated with triglycerides (P < 0.000), LDL-cholesterol (P < 0.001), systolic blood pressure (P < 0.001), cholesterol (P < 0.004), MDA (P < 0.004) and total oxygen stress (P < 0.004) in obese individuals. Both Hyc and DNA damage were negatively associated with total anti-oxidant response and globulin. Both Hcy profile and DNA damage may have a role in the endothelium damage even in the normal range and are related to triglycerides, ALT, MDA, TOS, HDL- and LDL-cholesterol in the Pakistani population.  相似文献   
207.
BackgroundGlioblastoma multiforme (GBM) is among the most aggressive cancers with a poor prognosis in spite of a plethora of established diagnostic and prognostic biomarkers and treatment modalities. Therefore, the current goal is the detection of novel biomarkers, possibly detectable in the blood of GBM patients that may enable an early diagnosis and are potential therapeutic targets, leading to more efficient interventions.ResultsWe identified 19 miRNAs with significantly different plasma levels in GBM patients, compared to the healthy individuals group with the difference limited by a factor of 2. Additionally, 11 viral miRNAs were found differentially expressed in plasma of GBM patients and 24 miRNA levels significantly correlated with the patients’ survival. Moreover, the overlap between the group of candidate miRNAs for diagnostic biomarkers and the group of miRNAs associated with survival, consisted of ten miRNAs, showing both diagnostic and prognostic potential. Among them, hsa miR 592 and hsa miR 514a 3p have not been previously described in GBM and represent novel candidates for selective biomarkers. The possible signalling, induced by the revealed miRNAs is discussed, including those of viral origin, and in particular those related to the impaired immune response in the progression of GBM.ConclusionThe GBM burden is reflected in the alteration of the plasma miRNAs pattern, including viral miRNAs, representing the potential for future clinical application. Therefore proposed biomarker candidate miRNAs should be validated in a larger study of an independent cohort of patients.  相似文献   
208.
Root-knot nematodes (RKNs) have been shown to be challenging and persistent pests of economic crops worldwide. Among RKNs, Meloidogyne javanica is particularly important, as it rapidly spreads and has a diverse host range. Measuring its damaging threshold level will help us to develop management strategies for adequate plant protection against nematodes. In our study, we observed the relationship between a linear series of 12 initial population densities (Pi) of M. javanica, i.e., 0, 0.125, 0.25, 0.5, 1, 2, 4, 8, 16, 32, 64, and 128 second-staged juveniles (J2s) g-1 soil, and fenugreek cv. UM202 growth parameters were investigated using a Seinhorst model. A Seinhorst model was fitted to shoot length and dry weight data for fenugreek plants. A positive correlation was found between J2s inoculum levels and percent reductions in growth parameters. The 1.3 J2s of M. javanica g-1 soil were found to damage threshold levels with respect to shoot length and shoot dry weight of fenugreek plants. The minimum relative values (m) for shoot length and shoot dry weight were 0.15 and 0.17, respectively, at Pi =128 J2s g-1 soil. The maximum nematode reproduction rate (Pf /Pi) was 31.6 at an initial population density (Pi) of 2 J2s g-1 soil.  相似文献   
209.
210.
Journal of Plant Growth Regulation - Meta-topolin (mT), a benzyladenine analog [N 6-(3-hydroxybenzylamino) purine] is a highly active cytokinin. The present study evaluates the efficiency of two...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号