全文获取类型
收费全文 | 495篇 |
免费 | 36篇 |
专业分类
531篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 20篇 |
2021年 | 31篇 |
2020年 | 27篇 |
2019年 | 51篇 |
2018年 | 31篇 |
2017年 | 22篇 |
2016年 | 35篇 |
2015年 | 34篇 |
2014年 | 35篇 |
2013年 | 49篇 |
2012年 | 40篇 |
2011年 | 35篇 |
2010年 | 23篇 |
2009年 | 20篇 |
2008年 | 8篇 |
2007年 | 16篇 |
2006年 | 13篇 |
2005年 | 7篇 |
2004年 | 11篇 |
2003年 | 5篇 |
2002年 | 2篇 |
2001年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1991年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有531条查询结果,搜索用时 0 毫秒
11.
12.
Inhibitory Effect of Hsa‐miR‐590‐5p on Cardiosphere‐derived Stem Cells Differentiation Through Downregulation of TGFB Signaling 下载免费PDF全文
13.
Elisabeth Le Bihan-Duval Javad Nadaf Cécile Berri Frédérique Pitel Beno?t Graulet Estelle Godet Sophie Y. Leroux Olivier Demeure Sandrine Lagarrigue Cécile Duby Larry A. Cogburn Catherine M. Beaumont Michel J. Duclos 《PloS one》2011,6(7)
Classical quantitative trait loci (QTL) analysis and gene expression QTL (eQTL) were combined to identify the causal gene (or QTG) underlying a highly significant QTL controlling the variation of breast meat color in a F2 cross between divergent high-growth (HG) and low-growth (LG) chicken lines. Within this meat quality QTL, BCMO1 (Accession number GenBank: ), encoding the β-carotene 15, 15′-monooxygenase, a key enzyme in the conversion of β-carotene into colorless retinal, was a good functional candidate. Analysis of the abundance of BCMO1 mRNA in breast muscle of the HG x LG F2 population allowed for the identification of a strong cis eQTL. Moreover, reevaluation of the color QTL taking BCMO1 mRNA levels as a covariate indicated that BCMO1 mRNA levels entirely explained the variations in meat color. Two fully-linked single nucleotide polymorphisms (SNP) located within the proximal promoter of BCMO1 gene were identified. Haplotype substitution resulted in a marked difference in BCMO1 promoter activity in vitro. The association study in the F2 population revealed a three-fold difference in BCMO1 expression leading to a difference of 1 standard deviation in yellow color between the homozygous birds at this haplotype. This difference in meat yellow color was fully consistent with the difference in carotenoid content (i.e. lutein and zeaxanthin) evidenced between the two alternative haplotypes. A significant association between the haplotype, the level of BCMO1 expression and the yellow color of the meat was also recovered in an unrelated commercial broiler population. The mutation could be of economic importance for poultry production by making possible a gene-assisted selection for color, a determining aspect of meat quality. Moreover, this natural genetic diversity constitutes a new model for the study of β-carotene metabolism which may act upon diverse biological processes as precursor of the vitamin A. AJ271386相似文献
14.
Sherafat MA Javan M Mozafari S Mirnajafi-Zadeh J Motamedi F 《Neurochemical research》2011,36(10):1887-1895
Multiple sclerosis (MS) is a demyelinating disease that affects the central nervous system. MS is the most common neurological
disorder in young adults with a greater incidence among females. Male gonadal hormones have a protective effect on neural
system development and myelin maturation. In this study, we investigate the effect of castration on lysolecithin-induced demyelination
and remyelination processes using visual evoked potentials, in addition to measuring the expressions of Olig2, MBP, Nogo-A
and GFAP mRNAs as oligodendrocyte or astrocyte markers; and histological assessments by myelin-specific staining. We observed
more expanded demyelination with delayed repair process in castrated rats. Expression levels of the aforementioned marker
genes confirmed histological and electrophysiological observations. Our results showed a pivotal role for endogenous male
hormones in the context of demyelinating insults. It may also account for the different prognosis of MS between male and female
genders and provide new insights for therapeutic treatments. 相似文献
15.
The effects of 10 commercial canola, Brassica napus L., cultivars widely grown in Iran--'SLM(046),' 'Opera,' 'Okapi,' 'RGS(003),' 'Modena,' 'Sarigol,' 'Zarfam,' 'Licord,' 'Hayula(420),' and 'Talaye'--on the demographic parameters of diamondback moth, Plutella xylostella L. (Lepidoptera-Plutellidae), were determined. The experiments were conducted in a growth chamber at 25 +/- 1 degrees C, 65 +/- 2% RH, and a photoperiod of 16:8 (L:D) h. The comparison of intrinsic rate of natural increase (r(m)), net reproductive rate (R0), and the survival rate of adult stage of P. xylostella on 10 canola cultivars suggested that this pest performed best on SLM(046). The r(m) value of P. xylostella ranged between 0.241 on RGS(003) and 0.304 on SLM(046). The R0, finite rate of increase (lambda), mean generation time (T), and doubling time (DT) values of P. xylostella on SLM(046) were 52, 1.35, 13.4, and 2.35 and on RGS(003) were 31, 1.27, 14.4, and 2.94, respectively. The Weibull model adequately described the shape of the survivorship curve of adult P. xylostella from life-table data. A significant fit was obtained with the Weibull model for P. xylostella in all experimental canola cultivars. As a result, SLM(046), Opera, and Hayula(420) were the most suitable hosts and had least negative impact on life-history statistics of the pest. 相似文献
16.
Sadegh Nouripour-Sisakht Ali Rezaei-Matehkolaei Mahdi Abastabar Mohammad Javad Najafzadeh Kazuo Satoh Bahram Ahmadi Leila Hosseinpour 《Mycopathologia》2013,176(1-2):157-160
Misidentifying with Microsporum gypseum has for a long time been accounted for less prevalence of the geophilic species, Microsporum fulvum in human dermatophytosis. We describe a new case of infection with the species in an Iranian young man. Direct examination of skin scrapings revealed a tinea corporis, and morphological study of the recovered isolate from the culture resulted in the identification of M. gypseum. However, PCR amplification of ITS1-5.8S rDNA-ITS2 region and subsequent ITS-RFLP and sequencing were indicative of M. fulvum as the true causative agent. To recognize M. fulvum in human infections and to validate the morphologically distinguished isolates of M. gypseum, the genetic-based identification is strongly recommended. 相似文献
17.
Kobra Omidfar Fatemeh Sadat Amjad Zanjani Arghavan Golbaz Hagh Maedeh Darziani Azizi Seyed Javad Rasouli Susan Kashanian 《Molecular biology reports》2013,40(12):6737-6745
Epidermal growth factor receptor (EGFR) is deemed to be one of the main molecular targets for diagnosis and treatment of cancer. It has been identified that EGFR involves in pathogenesis of some forms of human cancers. Monoclonal antibodies targeting EGFR could control the tumor cell growth, proliferation, and apoptosis by suppressing the signal transduction pathways. Nanobodies can be regarded as the smallest intact antigen binding fragments, derived from heavy chain-only antibodies existing in camelids. Here, we describe the identification of an EGFR-specific nanobody, referred to as OA-cb6, obtained from immunized camel with a cell line expressing high levels of EGFR. Utilizing flow cytometry (FACS) and blotting methods, we demonstrated that OA-cb6 nanobody binds specifically to EGFR expressing on the surface of A431 cells. In addition, OA-cb6 nanobody potently causes the inhibition of EGFR over expression, cell growth and proliferation. The antibody fragments can probably be regarded as worthwhile binding block for further rational design of anti-cancer therapy. 相似文献
18.
Amoli MM Amiri P Alborzi A Larijani B Saba S Tavakkoly-Bazzaz J 《Molecular biology reports》2012,39(9):8595-8599
To assess the expression of vascular endothelium growth factor (VEGF) mRNA in unstimulated peripheral blood mononuclear cells of patients with and without coronary artery disease (CAD). We also studied whether the functional VEGF -2,578C/A polymorphism may influence the level of VEGF mRNA expression in individuals undergoing coronary angiography because chest pain. We assessed 50 consecutive patients with angiographically confirmed CAD (CAD+). Also, 50 consecutive individuals with normal coronary studies were included in the study for comparison. VEGF mRNA expression was examined using quantitative real-time PCR and genotyping for VEGF -2,578C/A was performed using ARMS-PCR technique. VEGF mRNA expression was significantly decreased in CAD+ patients when compared to CAD- individuals (p = 0.01). The frequency of VEGF -2578 allele C and genotype CC was increased in CAD+ patients. In this regard, homozygosity for the CC genotype was more commonly observed in CAD+ (30 %) than in those without CAD disease (18 %). However, the difference was slightly out of the range of significance (p = 0.1). In addition, a trend for reduction in the expression of VEGF mRNA was observed when patients carrying the VEGF -2,578AA genotype were compared with those VEGF -2,578AC heterozygous or those homozygous for the VEGF -2,578CC genotype. VEGF gene expression is decreased in individuals with CAD+ disease. The VEGF -2,578C/A polymorphism may influences the expression of VEGF. 相似文献
19.
Alamtaj Samsami Dehaghani Khatere Shahriary Mohammad Amin Kashef Sirous Naeimi Mohammad Javad Fattahi Zahra Mojtahedi Abbas Ghaderi 《Molecular biology reports》2009,36(8):2393-2397
IL-18, initially defined as a potent inducer of IFN- γ production, is a systemic, multifunctional cytokine with both pro-cancerous
and anti-cancer activities. The contribution of the IL-18 promoter polymorphisms at positions −607 (C/A) and −137 (G/C) to
cancer development has been reported. We sought to examine IL-18 serum level and its polymorphisms in Iranian women with ovarian
cancer. Single nucleotide polymorphisms (SNPs) at positions −607 (C/A) and −137 (G/C) were analyzed by allele-specific polymerase
chain reaction in 85 women with ovarian cancer and 158 healthy controls. IL-18 serum level was determined using ELISA method.
No significant association was found between the allele, genotype, and haplotype distributions of the SNPs and ovarian cancer.
Mean IL-18 serum level was significantly higher in patients than in controls (P = 0.008). Comparing IL-18 serum levels with genotypes at positions −607 and −137 revealed no significant difference. No association
was also found between IL-18 levels and the disease stage. In conclusion, our results indicate that IL-18 promoter polymorphisms
at positions −607 (C/A) and −137 (G/C) appear not to confer susceptibility to ovarian cancer in Iranian population; however,
IL-18 serum level increases in ovarian cancer patients. 相似文献
20.
Hassan Mehrad-Majd Javad Akhtari Monir-Sadat Haerian Yalda Ravanshad 《Journal of cellular physiology》2019,234(4):4206-4216
PANDAR (promoter of CDKN1A antisense DNA damage activated RNA) has been shown to be aberrantly expressed in many types of cancer. Considering conflicting data, the current study was aimed to assess its potential role as a prognostic marker in malignant tumors. A comprehensive literature search of PubMed, Medline, and Web of Science was performed to identify all eligible studies describing the use of PANDAR as a prognostic factor for different types of cancer. Data related to overall survival (OS) and clinicopathologic features were collected and analyzed. The pooled hazard ratio (HR) and odds radio (OR) with a 95% confidence interval (CI) were used to estimate associations. Ten original studies containing 1,231 patients were included. The results showed that in patients with cancer, high PANDAR expression is correlated with lymph node metastasis (LNM; OR = 2.57; 95% CI, 1.76–3.81; p < 0.001), tumor stage (OR = 2.90; 95% CI, 1.25–6.75; p = 0.013), and tumor size (OR = 1.79; 95% CI, 1.11–2.91; p = 0.018). However, sensitivity analysis further demonstrated a significant association between high PANDAR expression and OS, both in multivariate and univariate analysis models (pooled HR 2.01; 95% CI, 1.17–3.44 and pooled HR 2.62; 95% CI, 1.98–3.47, respectively), after omitting one study. These results suggested that PANDAR expression might be indicative of advanced disease and poor prognosis in patients with cancer. Further studies are necessary to determine the value of this risk stratification biomarker in clinical management of patients with cancer. 相似文献