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   142篇
  免费   5篇
  国内免费   2篇
  2022年   3篇
  2021年   4篇
  2020年   4篇
  2019年   7篇
  2018年   4篇
  2017年   3篇
  2016年   3篇
  2015年   4篇
  2014年   9篇
  2013年   16篇
  2012年   21篇
  2011年   16篇
  2010年   6篇
  2009年   11篇
  2008年   5篇
  2007年   3篇
  2006年   7篇
  2005年   4篇
  2004年   8篇
  2003年   5篇
  2002年   1篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1974年   1篇
排序方式: 共有149条查询结果,搜索用时 31 毫秒
1.
2.
BackgroundTo date, the cause of inflammatory bowel disease (IBD) remains a mystery. A balance between cell proliferation and apoptosis maintains intestinal tissue homeostasis. Dissociation-induced myosin-actin contraction results in stem cell apoptosis. This study aiming to evaluate the influence of the myosin heavy chain 9 (MYH9) gene single nucleotide polymorphisms (SNPs) on inflammatory bowel disease.Subjectsand methods: The study carried on eighty patients with IBD and seventy controls. All participants subjected to history taking, thorough physical examination, colonoscopy and laboratory investigations. Genotyping performed for rs4821480 and rs3752462 by SNP assay real-time PCR methods.ResultsOn analyzing rs3752462 CT and TT genotypes were significantly more frequent in IBD patients as compared to controls with 4.6 fold increase in the risk of IBD. While on analyzing rs4821480, The TG and GG genotypes have significant increased distribution among the IBD patients as compared to the controls with 5.3 fold increase in the risk of IBD and higher prevalence of GG genotype in patients with low hemoglobin level and higher BMI.ConclusionThe rs3752462 T allele and rs4821480 G allele of MYH9 are associated with more susceptibility to IBD.  相似文献   
3.
4.

MicroRNAs (miRNAs) play important roles in liver pathologies and they are potential biomarkers for diagnosis of liver diseases progression. Changes in miRNA sera expression can be used as non-invasive biomarkers for hepatocellular carcinoma (HCC). The aim of the study was to identify the miRNome profiling of HCC and its diagnostic value in distinguishing HCC from healthy individuals. Expression profiles of miRNAs in serum samples of 20 HCC patients and 10 healthy controls were detected. Whole miRNome profiling was done using next generation sequencing. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic performance of the deregulated miRNAs for discriminating HCC cases from healthy controls. MiRNA 142 was highly expressed in HCC (P value?=?0.023) while miRNAs 191, 22, and 126 were higher in the controls (P value?=?0.005, 0.034, 0.010 respectively). We have identified 5 novel miRNAs and they were highly expressed in HCC than controls. Analysis of ROC curve demonstrated that these deregulated miRNAs can be used as a reliable biomarker for detection of HCC with high diagnostic accuracy (AUC?=?0.93). We have detected a panel of serum miRNAs that can be used as a reliable noninvasive screening biomarker of HCC. The study recommends further research to shed light on a possible role of the newly discovered novel miRNAs in HCC pathogenesis.

  相似文献   
5.
Seed sample of lentil collected from the Swabi district were treated with NaCl and KCl at 0.01, 0.1 and 1.0% (w/w). Seed-borne mycoflora was observed at 0, 20, 40, 60 and 80 day intervals. Seed treatment with both the salts was found to be effective against storage fungi; however, KCl was more efficient against storage mycoflora such as Aspergillus species when compared with NaCl. With the passage of time, the incidence of deep-seated fungi was observed in salt-treated seed samples while untreated seed sample showed heavy infestation by the species of Aspergillus. Seed viability also remained unaffected in storage, except in seeds heavily infested with seed-borne mycoflora. Aspergillus spp. were the main cause of seed rot. Surface sterilisation of seeds with 1% Na(OCl)2 reduced the fungal infestation of seeds. Among various concentrations of salts, 0.1% (w/w) of both salts were better in controlling seed-borne mycoflora.  相似文献   
6.
Dengue is the most important mosquito-borne viral disease. No specific treatment or vaccine is currently available; traditional vector control methods can rarely achieve adequate control. Recently, the RIDL (Release of Insect carrying Dominant Lethality) approach has been developed, based on the sterile insect technique, in which genetically engineered ‘sterile’ homozygous RIDL male insects are released to mate wild females; the offspring inherit a copy of the RIDL construct and die. A RIDL strain of the dengue mosquito, Aedes aegypti, OX513A, expresses a fluorescent marker gene for identification (DsRed2) and a protein (tTAV) that causes the offspring to die. We examined whether these proteins could adversely affect predators that may feed on the insect. Aedes aegypti is a peri-domestic mosquito that typically breeds in small, rain-water-filled containers and has no specific predators. Toxorhynchites larvae feed on small aquatic organisms and are easily reared in the laboratory where they can be fed exclusively on mosquito larvae. To evaluate the effect of a predator feeding on a diet of RIDL insects, OX513A Ae. aegypti larvae were fed to two different species of Toxorhynchites (Tx. splendens and Tx. amboinensis) and effects on life table parameters of all life stages were compared to being fed on wild type larvae. No significant negative effect was observed on any life table parameter studied; this outcome and the benign nature of the expressed proteins (tTAV and DsRed2) indicate that Ae. aegypti OX513A RIDL strain is unlikely to have any adverse effects on predators in the environment.  相似文献   
7.
The maximum quantum yield of photosystem II (as reflected by variable to maximum chlorophyll a fluorescence, Fv/Fm) is regarded as one of the most important photosynthetic parameters. The genetic basis underlying natural variation in Fv/Fm, which shows low level of variations in plants under non‐stress conditions, is not easy to be exploited using the conventional gene cloning approaches. Thus, in order to answer this question, we have followed another strategy: we used genome‐wide association study (GWAS) and transgenic analysis in a rice mini‐core collection. We report here that four single‐nucleotide polymorphisms, located in the promoter region of β‐glucosidase 5 (BGlu‐5), are associated with observed variation in Fv/Fm. Indeed, our transgenic analysis showed a good correlation between BGlu‐5 and Fv/Fm. Thus, our work demonstrates the feasibility of using GWAS to study natural variation in Fv/Fm, suggesting that cis‐element polymorphism, affecting the BGlu‐5 expression level, may, indirectly, contribute to Fv/Fm variation in rice through the gibberellin signaling pathway. Further research is needed to understand the mechanism of our novel observation.  相似文献   
8.
Hamdani  Saber  Khan  Naveed  Perveen  Shahnaz  Qu  Mingnan  Jiang  Jianjun  Govindjee  Zhu  Xin-Guang 《Photosynthesis research》2019,139(1-3):107-121
Photosynthesis Research - Non-photochemical quenching (NPQ) of the excited state of chlorophyll a is a major photoprotective mechanism plants utilize to survive under high light. Here, we report...  相似文献   
9.
Fragile histidine trail (FHIT) is a tumor suppressor in response to DNA damage which has been deleted in various tumors. However, the signaling mechanisms and interactions of FHIT with regard to apoptotic proteins including p53 and p38 in the DNA damage-induced apoptosis are not well described. In the present study, we used etoposide-induced DNA damage in MCF-7 as a model to address these crosstalks. The time course study showed that the expression of FHIT, p53, and p38MAPK started after 1 hour following etoposide treatment. FHIT overexpression led to increase p53 expression, p38 activation, and augmented apoptosis following etoposide-induced DNA damage compared to wild-type cells. However, FHIT knockdown blocked p53 expression, delayed p38 activation, and completely inhibited etoposide-induced apoptosis. Inhibition of p38 activity prevented induction of p53, FHIT, and apoptosis in this model. Thus, activation of p38 upon etoposide treatment leads to increase in FHIT and p53 expression. In p53 knockdown MCF-7, the FHIT induction was hampered but p38 activation was induced in lower doses of etoposide. In p53 knockdown cells, inhibition of p38 induced FHIT expression and apoptosis. Our data demonstrated that the exposure of MCF-7 cells to etoposide increases apoptosis through a mechanism involving the activation of the p38-FHIT-p53 pathway. Moreover, our findings suggest signaling interaction for these pathways may represent a promising therapy for breast cancer.  相似文献   
10.
The locomotor activity rhythm of the media workers of the ant species Camponotus compressus was monitored under constant conditions of the laboratory to understand the role of circadian clocks in social organization. The locomotor activity rhythm of most ants entrained to a 24 h light/dark (12:12 h; LD) cycle and free-ran under constant darkness (DD) with circadian periodicities. Under entrained conditions about 75% of media workers displayed nocturnal activity patterns, and the rest showed diurnal activity patterns. In free-running conditions these ants displayed three types of activity patterns (turn-around). The free-running period (τ) of the locomotor activity rhythm of some ants (10 out of 21) showed period lengthening, and those of a few (6 out of 21) showed period shortening, whereas the locomotor activity rhythm of the rest of the ants (5 out of 21) underwent large phase shifts. Interestingly, the pre-turn-around τ of those ants that showed nocturnal activity patterns during earlier LD entrainment was shorter than 24 h, which became greater than 24 h after 6-9 days of free-run in DD. On the other hand, the pre-turn-around τ of those ants, which exhibited diurnal patterns during earlier LD entrainment, was greater than 24 h, which became shorter than 24 h after 6-9 days of free-run in DD. The patterns of activity under LD cycles and the turn-around of activity patterns in DD regime suggest that these ants are shift workers in their respective colonies, and they probably use their circadian clocks for this purpose. Circadian plasticity thus appears to be a general strategy of the media workers of the ant species C. compressus to cope with the challenges arising due to their roles in the colony constantly exposed to a fluctuating environment.  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