全文获取类型
收费全文 | 153篇 |
免费 | 6篇 |
出版年
2021年 | 3篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2016年 | 8篇 |
2015年 | 8篇 |
2014年 | 6篇 |
2013年 | 9篇 |
2012年 | 10篇 |
2011年 | 7篇 |
2010年 | 2篇 |
2009年 | 17篇 |
2008年 | 6篇 |
2007年 | 6篇 |
2006年 | 7篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1986年 | 3篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1974年 | 4篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1968年 | 2篇 |
排序方式: 共有159条查询结果,搜索用时 31 毫秒
81.
P Madeddu F Pala C Troffa P Pinna Parpaglia A Pazzola A Soro P Manunta G Tonolo M G Melis M P Demontis 《Bollettino della Società italiana di biologia sperimentale》1990,66(7):671-678
We studied the effect of nifedipine, a dihydropyridine calcium antagonist, on the hemodynamic changes induced by endothelin, in awake normotensive rats. Endothelin (0.07-1.40 nmol/kg, e.v.) caused an initial hypotensive effect, followed by long lasting hypertension. Renal blood flow was reduced immediately and still remained below basal levels, at 30 minutes after endothelin injection. Nifedipine (1 mg/kg, i.p.) significantly prevented the effect of endothelin on mean blood pressure and induced a right-ward shift in the dose response curve of renal hemodynamic changes induced by endothelin. We conclude that treatment with calcium antagonist could be very useful in all those conditions in which systemic and regional vasocostriction is provoked by endothelin. 相似文献
82.
Danielle M. Pala Denize D. de Carvalho Jos Carlos Pinto Geraldo L. SantAnna Jr. 《International biodeterioration & biodegradation》2006,58(3-4):254
A critical environmental impact of the petroleum industry is the spillage of oil and related products that causes severe soil contamination. Although biodegradation of petroleum hydrocarbons may be successfully conducted under controlled conditions, the bioremediation of large volumes of contaminated soils still presents some technical challenges, particularly when contamination occurs in soils of high clay content. The main objective of this work is to evaluate the bioremediation of petroleum-contaminated clay-soil by fixed bed experiments. They were conducted in agreement with the full factorial experimental design 23. The processes employed were shown to be highly effective in decontaminating the soil, achieving removal rates of around 80%. The model chosen to represent the bioremediation process provided satisfactory results. The values calculated by the model were consistent with the experimental results. 相似文献
83.
84.
Haplogroup effects and recombination of mitochondrial DNA: novel clues from the analysis of Leber hereditary optic neuropathy pedigrees
下载免费PDF全文
![点击此处可从《American journal of human genetics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Carelli V Achilli A Valentino ML Rengo C Semino O Pala M Olivieri A Mattiazzi M Pallotti F Carrara F Zeviani M Leuzzi V Carducci C Valle G Simionati B Mendieta L Salomao S Belfort R Sadun AA Torroni A 《American journal of human genetics》2006,78(4):564-574
The mitochondrial DNA (mtDNA) of 87 index cases with Leber hereditary optic neuropathy (LHON) sequentially diagnosed in Italy, including an extremely large Brazilian family of Italian maternal ancestry, was evaluated in detail. Only seven pairs and three triplets of identical haplotypes were observed, attesting that the large majority of the LHON mutations were due to independent mutational events. Assignment of the mutational events into haplogroups confirmed that J1 and J2 play a role in LHON expression but narrowed the association to the subclades J1c and J2b, thus suggesting that two specific combinations of amino acid changes in the cytochrome b are the cause of the mtDNA background effect and that this may occur at the level of the supercomplex formed by respiratory-chain complexes I and III. The families with identical haplotypes were genealogically reinvestigated, which led to the reconnection into extended pedigrees of three pairs of families, including the Brazilian family with its Italian counterpart. The sequencing of entire mtDNA samples from the reconnected families confirmed the genealogical reconstruction but showed that the Brazilian family was heteroplasmic at two control-region positions. The survey of the two sites in 12 of the Brazilian subjects revealed triplasmy in most cases, but there was no evidence of the tetraplasmy that would be expected in the case of mtDNA recombination. 相似文献
85.
CCN2 is necessary for adhesive responses to transforming growth factor-beta1 in embryonic fibroblasts 总被引:10,自引:0,他引:10
86.
87.
In fish of the Squalius alburnoides complex, hybridisation and polyploidy have affected sex ratios, resulting in strong correlations between sex and genotype. The preponderance of females among triploids and the occurrence of an all male lineage among diploids seem to imply that sex ratio deviations should have a strong genetic basis. Until now, no information has been gathered regarding the molecular basis of sex determination in this intricate hybrid system. Thus, putative regulatory elements of the cascade that potentially are involved in sex determination in S. alburnoides have to be investigated. Being reported to have an important role in teleost sex determination, and more particularly in male gonad development, the anti-Müllerian hormone, amh was a good initial candidate. Here we report the isolation, cloning and characterization of the amh ortholog in S. alburnoides and the ancestral species S. pyrenaicus. In adult S. alburnoides and S. pyrenaicus of both sexes, amh shows a gonad specific expression pattern, restricted to the Sertoli cell lineage in testis and to granulosa cells in ovaries. During development, it plays an early role in male gonad differentiation in S. alburnoides. Overall the observed patterns are similar to what has been reported in other teleost species. This suggests a conserved role of amh and implies that its expression dynamics cannot be directly responsible for the sex ratio deviations reported in S. alburnoides. It is possible that a conjunction of other factors could be contributing for sex ratio imbalance. The present results constitute the starting point in the characterization of the S. alburnoides sex determination cascade, a process that we expect to shed some light on the molecular basis of sex distribution, within the context of hybrid system evolution. 相似文献
88.
Shazia Parveen Abdul Hamid Wani Athar Ali Ganie Shaukat Ahmad Pala Riyaz Ahmad Mir 《Archives Of Phytopathology And Plant Protection》2013,46(3):279-284
The inhibitory activity of five plant extracts viz. Artemisia absinthium L., Rumex obtusifolius L., Taraxacum officinale Weber ex Wiggers, Plantago lanceolata L. and Malva sylvestris L. were evaluated against the mycelial growth of three fungi Alternaria alternata (Fr.) Keissler, Penicillium expansum Link ex Thom. and Mucor piriformis Fisher that cause rot diseases in fruits and vegetables resulting in low yield and quality of fruits and vegetables. Results revealed that all the concentrations of plant extracts brought about significant inhibition in the mycelial growth of these pathogenic fungi. However, the highest concentration caused maximum inhibition in the mycelial growth followed by lower concentrations of plant extracts. The extract of A. absinthium leaves at highest concentration (S) proved highly effective in inhibiting the mycelial growth of all these pathogenic fungi followed by other plant extracts. These plants thus may have potential as the new natural fungicide for management of fungal rot diseases. 相似文献
89.
Eduardo AVF Ramalho Jo?o LQ Silva-Filho Marina FS Cartaxo Carmelita BL Cavalcanti Moacyr JBM Rêgo Maria BM Oliveira Eduardo IC Beltr?o 《Biological research》2014,47(1)
Background
BRCA protein interacts with at least 13 different proteins that have been implicated with cancer susceptibility and loss of BRCA function is correlated to sensitivity to DNA crosslinking agents in preclinical models.Results
BRCA2 methylation frequency was 44%, p53 Pro22 allele frequency was 32% and heterozygous frequency of Arg/Pro72 genotype was 60% which could be associated as risk factor for metastasis (p = 0.046 OR = 4.190). Regarding to polymorphism of codon 249 the frequency of Arg249 allele presented 82% which was considered not statistically significant.Conclusions
There was not statistical significance to BRCA2 promoter methylation with any parameters chosen. However, our findings suggest that patients who present heterozygous genotype at codon 72 of p53 gene may have a major susceptibility to any type of metastasis and this could serve as potential auxiliary biomarker for poor prognosis. 相似文献90.
Annelies Stevaert Roberto Dallocchio Alessandro Dessì Nicolino Pala Dominga Rogolino Mario Sechi Lieve Naesens 《Journal of virology》2013,87(19):10524-10538
The influenza virus PA endonuclease, which cleaves capped host pre-mRNAs to initiate synthesis of viral mRNA, is a prime target for antiviral therapy. The diketo acid compound L-742,001 was previously identified as a potent inhibitor of the influenza virus endonuclease reaction, but information on its precise binding mode to PA or potential resistance profile is limited. Computer-assisted docking of L-742,001 into the crystal structure of inhibitor-free N-terminal PA (PA-Nter) indicated a binding orientation distinct from that seen in a recent crystallographic study with L-742,001-bound PA-Nter (R. M. DuBois et al., PLoS Pathog. 8:e1002830, 2012). A comprehensive mutational analysis was performed to determine which amino acid changes within the catalytic center of PA or its surrounding hydrophobic pockets alter the antiviral sensitivity to L-742,001 in cell culture. Marked (up to 20-fold) resistance to L-742,001 was observed for the H41A, I120T, and G81F/V/T mutant forms of PA. Two- to 3-fold resistance was seen for the T20A, L42T, and V122T mutants, and the R124Q and Y130A mutants were 3-fold more sensitive to L-742,001. Several mutations situated at noncatalytic sites in PA had no or only marginal impact on the enzymatic functionality of viral ribonucleoprotein complexes reconstituted in cell culture, consistent with the less conserved nature of these PA residues. Our data provide relevant insights into the binding mode of L-742,001 in the PA endonuclease active site. In addition, we predict some potential resistance sites that should be taken into account during optimization of PA endonuclease inhibitors toward tight binding in any of the hydrophobic pockets surrounding the catalytic center of the enzyme. 相似文献