全文获取类型
收费全文 | 148篇 |
免费 | 9篇 |
出版年
2023年 | 2篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 12篇 |
2014年 | 6篇 |
2013年 | 20篇 |
2012年 | 15篇 |
2011年 | 17篇 |
2010年 | 5篇 |
2009年 | 3篇 |
2008年 | 2篇 |
2007年 | 6篇 |
2006年 | 1篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1982年 | 2篇 |
排序方式: 共有157条查询结果,搜索用时 31 毫秒
41.
Hamid Badali Seyed Amir Yazdanparast Alexandro Bonifaz Bita Mousavi G. Sybren de Hoog Corné H. W. Klaassen Jacques F. Meis 《Mycopathologia》2013,175(5-6):505-513
Inter- and intraspecific genomic variability of 18 isolates of Veronaea botryosa originating from clinical and environmental sources was studied using amplified fragment length polymorphism (AFLP). The species was originally described from the environment, but several severe cases of disseminated infection in apparently healthy individuals have been reported worldwide. All tested strains of V. botryosa, identified on the basis of sequencing and phenotypic and physiological criteria prior to our study, were confirmed by AFLP analysis, yielding a clear separation of V. botryosa as a rather homogeneous group from related species. In vitro antifungal susceptibility testing resulted in MIC90s across all strains in increasing order posaconazole (0.25 μg/ml), itraconazole (1 μg/ml), voriconazole (4 μg/ml), terbinafine (4 μg/ml), caspofungin (8 μg/ml), anidulafungin (8 μg/ml), isavuconazole (16 μg/ml), amphotericin B (16 μg/ml), and fluconazole (32 μg/ml). Overall, the isolates showed a uniform pattern of low MICs of itraconazole and posaconazole, but high MICs for remaining agents. The echinocandins (caspofungin and anidulafungin) had no activity against V. botryosa. There was no statistically significant difference between susceptibilities of environmental (n = 11) and clinical (n = 7) isolates of V. botryosa (P > 0.05). 相似文献
42.
Stoats are significant predators of native fauna in New Zealand. They occur in many habitat types and consume a wide range of prey. The diet of stoats in the Tasman River, South Canterbury, was studied by analysis of scats and den contents. Analysis of 206 scats showed that stoats ate mainly lagomorphs, birds and invertebrates. Minor components included mice, lizards, fish and hedgehogs. Stoats ate more birds in spring than in autumn, and female stoats ate more invertebrates than did males. The contents of 219 dens collected in the same area at the same time provided further information. Birds and lagomorphs occurred at high frequency in dens, and other components were minor. Remains in dens were larger than in scats and allowed identification of many more prey items to species level. Den contents revealed a potentially substantial impact of stoats on threatened shorebirds locally; this impact was not detected by analysis of scats. 相似文献
43.
Abolfazl Dashtbani-Roozbehani Bita Bakhshi Mohammad Reza Pourshafie 《Current microbiology》2013,67(1):15-20
Sequence analysis of dnaE, hlyA, and asd housekeeping genes were used to determine the genetic relatedness of our collection of Vibrio cholerae isolated from patients and surface waters over a 5-year period in Iran. The results showed 41, 17, and 9 variable sites throughout the sequenced fragments of dnaE (837 bp), hlyA (495 bp), and asd (295 bp), respectively. The results from sequence typing showed that all our clinical isolates were grouped in the same cluster. Eleven genotypes were identified among the environmental isolates. One environmental isolate was found to be in close genetic relatedness with our clinical isolates. One V. cholerae isolate showed a single-locus variant in the dnaE. For each of the studied genetic loci 10, 7, and 7 sequence types were observed for dnaE, hlyA, and asd, respectively. Only asd sequence analysis could make the distinction between the classical and El Tor isolates which emphasizes on selection of housekeeping locus with better discrimination power for analysis of different groups of isolates. Overall, the results indicated that surface waters in Tehran are a pool of non-toxigenic V. cholerae strains which are rarely related to clinical toxigenic isolates. In addition, our results verified that housekeeping gene sequence analysis could be a suitable approach for determination of the relatedness between clinical and environmental V. cholerae isolates. 相似文献
44.
Bita Naseri 《Journal of Phytopathology》2013,161(11-12):814-822
The associations of Rhizoctonia root rot (RRR) with a number of agronomic and yield variables were characterized at different growth stages in 122 commercial bean fields in Zanjan, Iran. A lower RRR incidence was detected in red beans compared with white beans. RRR incidence was greater in drought‐exposed fields compared with drought‐free fields. RRR incidence was higher following frequent irrigations at 2‐ to 3‐day intervals than at 4‐ to 9‐day intervals. The highest RRR incidence was associated with the densest category of plant populations and with the deepest plantings at 10–22 cm. Beans grown following alfalfa, bean and maize had a lower disease than rotations with potato. RRR incidence was greater in fields that received 50–500 kg/ha of urea compared with nonfertilized fields. RRR‐affected fields were recognized with a closer irrigation, earlier and deeper planting, denser weed population and lower yields than RRR‐free fields. According to loadings for second principal component, planting density and depth, urea usage and weed density corresponded with RRR incidence. Findings extend our understanding of RRR epidemics in diverse bean cropping systems. 相似文献
45.
Molecular and craniological analysis of leopard,Panthera pardus (Carnivora: Felidae) in Iran: support for a monophyletic clade in Western Asia 下载免费PDF全文
46.
The frequency and distribution of thiopurine S-methyltransferase alleles in south Iranian population
Moini M Ghaderi F Sagheb MM Tavasolli AR Azarpira N Darai M Geramizadeh B 《Molecular biology reports》2012,39(4):4581-4587
Thiopurine methyltransferase (TPMT) catalyzes the S-methylation of thiopurine drugs such as 6-mercaptopurine, 6-thioguanine,
and azathiopurine. Variability in TPMT activity is mainly due to genetic polymorphism. The frequency of the four allelic variants
of the TPMT gene, TPMT*2 (G238C), TPMT*3A (G460A and A719G), TPMT*3B (G460A) and TPMT*3C (A719G) were determined in an Iranian
population from south of Iran (n = 500), using polymerase chain reaction (PCR)-RFLP and allele-specific PCR-based assays. Four hundred seventy four persons
(94.8%) were homozygous for the wild type allele (TPMT*1/*1) and twenty five people were TPMT*1/*3C (5%). One patient was found to be heterozygous in terms TPMT*1 and *2 alleles
with genotype of TPMT*1/*2 (0.2%). None of the participants had both defective alleles. The TPMT*3C and *2 were the only variant
alleles observed in this population. The total frequency of variant alleles was 2.6% and the wild type allele frequency was
97.4%. The TPMT*3B and *3A alleles were not detected. Distributions of TPMT genotype and allele frequency in Iranian populations
are different from the genetic profile found among Caucasian or Asian populations. Our findings also revealed inter-ethnic
differences in TPMT frequencies between different parts of Iran. This view may help clinicians to choose an appropriate strategy
for thiopurine drugs and reduce adverse drug reactions such as bone marrow suppression. 相似文献
47.
CD28, cytotoxic T-lymphocyte associated antigen 4 (CTLA4), inducible costimulator (ICOS) and programmed cell death 1 are closely-linked genes located on chromosome 2q and encode co-stimulatory molecules, which are T-cell activity regulators. The principal assignment of T-cell mediated immune response in allograft rejection is an interesting topic of multiple studies. Although the variation in these genes may influence the graft survival and the amount of immunosuppression needed, the studies so far have been restricted solely to the CTLA4 gene. In 145 patients who underwent liver allograft transplantation, 10 single nucleotide polymorphisms of CD28, CTLA4, ICOS, and PD.1 genes were defined. To distinguish the polymorphisms of all 10 SNPs, PCR-RFLP method was used and according to the standard criteria, acute rejection episodes were determined. CTLA4-1661, AA genotype was significantly more frequent in the patients with acute rejection and AG genotype was significantly more frequent in the patients without rejection. Frequencies of CTLA4+49 AG A allele and CTLA4-1661AG A allele were significantly higher than those of CTLA4+49 AG and CTLA4-1661AG, G allele in the patients with acute rejection. ICOS+693, GG genotype and G allele were significantly less frequent in the patients with acute rejection and CD28 CT genotype was significantly more in patients with acute rejection. The present results demonstrate that potentially functional genetic variation in T-cell co-stimulatory molecules including ICOS, CTLA4 and CD28 can influence liver transplant outcome. 相似文献
48.
49.
Aims
Considering the key role played by the apolipoprotein E (Apo E) gene in the regulation of lipid metabolism and obesity, the current study has evaluate the association between abdominal obesity and Apo E gene polymorphism in a population of Tehran.Materials and methods
A cross-sectional study was performed on 345 men and 498 women, aged 19–86 years, selected from among participants of the Tehran Lipid and Glucose Study. The RFLP-PCR technique was employed to investigate polymorphism in the gene fragments. Based on the national survey of risk factors for non-communicable diseases of Iran, waist circumference (WC) cut off was set at 89 cm for men and 91 cm for women. The risk effect of obesity related variables and lipid profiles in two groups of WC were examined by logistic regression. For body mass index (BMI), waist to hip ratio (WHR), high-density lipoprotein-cholesterol (HDL-C), triglyceride (TG), fasting blood sugar (FBS), total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), and blood pressure (BP), the standard risk cut-offs were applied.Results
Frequencies of E2, E3, and E4 alleles were 9.7, 73, and 14.6%, respectively. The presence of the E3 allele was significantly associated with higher TG level in subjects with high WC, while, the presence of E4 allele decreased the plasma HDL-C (E2:52.1 ± 13.1 vs., E3:48.9 ± 11.2 vs., E4:44.6 ± 10.6 mg/dl, p < 0.05), HDL-C2 (E2:20.4 ± 9.2 vs., E3:19.1 ± 8.8 vs., E4:16.3 ± 7.9 mg/dl, p < 0.05), and HDL-C3 (E2:32.1 ± 7.4 vs., E3:30.3 ± 6.2 vs., E4:28.3 ± 6.1 mg/dl, p < 0.05) in normal WC subjects. The presence of the E3 carrier increased the risk of having higher plasma TG, compared with the E2 carrier (95% CI OR = 1.91, 1.02–3.57; p = 0.04).Conclusion
According to the results of this study, the E3 carrier, caused an approximately 90% increase in the levels of TG in the group with abdominal obesity. 相似文献50.
Our understanding of how value-related information is encoded in the ventral tegmental area (VTA) is based mainly on the responses of individual putative dopamine neurons. In contrast to cortical areas, the nature of coordinated interactions between groups of VTA neurons during motivated behavior is largely unknown. These interactions can strongly affect information processing, highlighting the importance of investigating network level activity. We recorded the activity of multiple single units and local field potentials (LFP) in the VTA during a task in which rats learned to associate novel stimuli with different outcomes. We found that coordinated activity of VTA units with either putative dopamine or GABA waveforms was influenced differently by rewarding versus aversive outcomes. Specifically, after learning, stimuli paired with a rewarding outcome increased the correlation in activity levels between unit pairs whereas stimuli paired with an aversive outcome decreased the correlation. Paired single unit responses also became more redundant after learning. These response patterns flexibly tracked the reversal of contingencies, suggesting that learning is associated with changing correlations and enhanced functional connectivity between VTA neurons. Analysis of LFP recorded simultaneously with unit activity showed an increase in the power of theta oscillations when stimuli predicted reward but not an aversive outcome. With learning, a higher proportion of putative GABA units were phase locked to the theta oscillations than putative dopamine units. These patterns also adapted when task contingencies were changed. Taken together, these data demonstrate that VTA neurons organize flexibly as functional networks to support appetitive and aversive learning. 相似文献