全文获取类型
收费全文 | 1659篇 |
免费 | 81篇 |
国内免费 | 1篇 |
出版年
2024年 | 6篇 |
2023年 | 22篇 |
2022年 | 38篇 |
2021年 | 84篇 |
2020年 | 44篇 |
2019年 | 42篇 |
2018年 | 62篇 |
2017年 | 49篇 |
2016年 | 61篇 |
2015年 | 73篇 |
2014年 | 88篇 |
2013年 | 151篇 |
2012年 | 135篇 |
2011年 | 122篇 |
2010年 | 68篇 |
2009年 | 60篇 |
2008年 | 76篇 |
2007年 | 71篇 |
2006年 | 58篇 |
2005年 | 51篇 |
2004年 | 54篇 |
2003年 | 48篇 |
2002年 | 37篇 |
2001年 | 12篇 |
2000年 | 12篇 |
1999年 | 17篇 |
1998年 | 9篇 |
1997年 | 11篇 |
1996年 | 14篇 |
1995年 | 7篇 |
1994年 | 14篇 |
1993年 | 11篇 |
1992年 | 9篇 |
1991年 | 7篇 |
1990年 | 9篇 |
1988年 | 8篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1985年 | 7篇 |
1984年 | 8篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1979年 | 6篇 |
1977年 | 5篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1971年 | 5篇 |
1970年 | 4篇 |
1969年 | 7篇 |
1966年 | 3篇 |
排序方式: 共有1741条查询结果,搜索用时 31 毫秒
181.
Ismail Thanseem Kumarasamy Thangaraj Gyaneshwer Chaubey Vijay Kumar Singh Lakkakula VKS Bhaskar B Mohan Reddy Alla G Reddy Lalji Singh 《BMC genetics》2006,7(1):1-11
Background
Past work on asthmatic African American families revealed a strong linkage peak with modest evidence of association on chromosome 11q. Here, we perform tests of association for asthma and a panel of 609 SNPs in African American subjects using a sliding window approach. While efficient in screening a region of dense genotyping, this approach does create some problems: high numbers of tests, assimilating thousands of results, and questions about setting priorities on regions with association signals.Results
We present a newly developed tool, Graphical Assessment of Sliding P-values or GrASP, which uses color display to indicate the width of the sliding windows, significance of individual tests, density of SNP coverage and location of known genes that simplifies some of these issues, and use it to identify regions of interest in these data.Conclusion
We demonstrate that GrASP makes it easier to visualize, summarize and prioritize regions of interest from sliding window haplotype analysis, based jointly on the p-value from all the tests from these windows and the building of haplotypes of significance in the region. Using this approach, five regions yielded strong evidence for linkage and association with asthma, including the prior peak linkage region. 相似文献182.
Demirayak S Beis R Karaburun AC Kayagil I Incesu Z Ucucu U 《Journal of enzyme inhibition and medicinal chemistry》2006,21(1):113-118
Some 1,5-diaryl-3-ethoxycarbonyl-2-methylpyrrole derivatives were obtained by reacting 1-aryl-3-ethoxycarbonylpent-1,4-diones and a suitable aniline derivative or sulfanilamide under Paal-Knorr pyrrole synthesis conditions. The cytotoxicity of the compounds was tested and all compounds, except for compound 2 h, showed a time-dependent increase in cytotoxic activity. Analgesic activities of the compounds were determined by using the tail-flick and tail-immersion methods; some of the compounds showed potent analgesic activity. 相似文献
183.
Naghmouchi K Hammami R Fliss I Teather R Baah J Drider D 《Archives of microbiology》2012,194(5):363-370
Recently, we isolated and reported the antagonism of Paenibacillus polymyxa JB05-01-1 (P. polymyxa JB05-01-1) against Gram-negative bacteria. Here, we provide more insights and attribute the abovementioned antagonism to
the production of colistins A and B, which were purified by Amberlite column exchange, C18 column hydrophobicity, superdex
75 16/60 gel filtration chromatography connected to fast protein liquid chromatography and identified by MALDI TOF/TOF, and
manual nanospray analysis. The amount of colistin A and colistin B recovered from 500 ml of culture supernatant was about
0.05 mg. The specific activity and the average recovery of the eluted substances were 5,120 AU/mg and 1.1%, respectively.
The minimal inhibitory concentrations of the purified colistins against Escherichia coli O157:H7 and Pseudomonas fluorescens LRC R73 were 0.13 and 0.62 μg/ml, respectively. 相似文献
184.
Investigate the chronic neurotoxic effects of diquat 总被引:1,自引:0,他引:1
Karuppagounder SS Ahuja M Buabeid M Parameshwaran K Abdel-Rehman E Suppiramaniam V Dhanasekaran M 《Neurochemical research》2012,37(5):1102-1111
Chronic exposure to agricultural chemicals (pesticides/herbicides) has been shown to induce neurotoxic effects or results
in accumulation of various toxic metabolic by-products. These substances have the relevant ability to cause or increase the
risk for neurodegeneration. Diquat is an herbicide that has been extensively used in the United States of America and other
parts of the world. Diquat is constantly released into the environment during its use as a contact herbicide. Diquat structurally
resembles 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP) and paraquat. Rotenone, paraquat, maneb and MPTP reproduce features
of movement disorders in experimental animal models. Based on the structural similarity to other neurotoxins, chronic exposure
of diquat can induce behavioral and neurochemical alterations associated with dopaminergic neurotoxicity. However, in the
present study, diquat unlike other neurotoxins (rotenone, 6-hydroxydopamine, MPTP, paraquat and maneb) did not induce dopamine
depletion in the mouse striatum. Although, notable exacerbation in motor impairment (swimming score, akinesia and open field)
were evident that may be due to the decreased dopamine turnover and mild nigrostriatal neurodegeneration. These data indicate
that, despite the apparent structural similarity to other dopaminergic neurotoxins, diquat did not exert severe deleterious
effects on dopamine neurons in a manner that is unique to rotenone and MPTP. 相似文献
185.
Isolation, characterization and virulence of the culturable bacteria from entire tissues of larval Ostrinia nubilalis (Hübner) (Lepidoptera: Pyralidae) were studied to obtain new microbes for biological control. A total of 16 bacteria were isolated from living and dead larvae collected from different maize fields in the Eastern Black Sea Region of Turkey. The bacterial microbiota of O. nubilalis were identified as Pseudomonas aeruginosa (On1), Brevundimonas aurantiaca (On2), Chryseobacterium formosense (On3), Acinetobacter sp. (On4), Microbacterium thalassium (On5), Bacillus megaterium (On6), Serratia sp. (On7), Ochrobactrum sp. (On8), Variovorax paradoxus (On9), Corynebacterium glutamicum (On10), Paenibacillus sp. (On11), Alcaligenes faecalis (On12), Microbacterium testaceum (On13), Leucobacter sp. (On14), Leucobacter sp. (On15) and Serratia marcescens (On16) based on their morphological and biochemical characteristics. A partial sequence of the 16S rRNA gene was also determined to confirm strain identification. The highest insecticidal activities were obtained from P. aeruginosa On1 (80%), Serratia sp. On7 (60%), V. paradoxus On9 (50%) and S. marcescens On16 (50%) against larvae 14 days after treatment (p < 0.05). Also, the highest activity from previously isolated Bacillus species was observed from Bacillus thuringiensis subsp. tenebrionis Xd3 with 80% mortality within the same period (p < 0.05). Our results indicate that P. aeruginosa On1, Serratia sp. On7, V. paradoxus On9, S. marcescens On16 and B. thuringiensis subsp. tenebrionis Xd3 show potential for biocontrol of O. nubilalis. 相似文献
186.
Salmah Ismail Teow Chong Teoh Choong Yong Ung Saad Musbah Alasil Rahmat Omar 《Biologia》2012,67(6):1031-1037
Paenibacillus spp. are Gram-positive, facultatively aerobic, bacilli-shaped endospore-forming bacteria. They have been detected in a variety of environments, such as soil, water, forage, insect larvae, and even clinical samples. The strain 139SI (GenBank accession No.: JF825470.1) from three strains of Paenibacillus isolates investigated here was chosen as the type strain of the proposed novel species. The other two similar strain isolates investigated were 140SI (JF825471.1) and 141SI (JQ734548.1). These strains were identified as members of the genus Paenibacillus on the basis of phenotypic characteristics, phylogenetic analysis and 16S rRNA G+C content. Surprisingly, these strains exhibited a strong hemolytic activity on 5% sheep blood agar. Their crude extracts also showed positive growth-promoting activities in colon cancer and Vero cell lines. To our knowledge, this is the first Paenibacillus with hemolytic and growth-promoting activities reported, and the name Paenibacillus hemolyticus for this novel species is proposed. The capability of this novel species in hemolytic and cell growth activities suggests its potential in both clinical and pharmacological implications. 相似文献
187.
S100P dissociates myosin IIA filaments and focal adhesion sites to reduce cell adhesion and enhance cell migration 总被引:1,自引:0,他引:1
Du M Wang G Ismail TM Gross S Fernig DG Barraclough R Rudland PS 《The Journal of biological chemistry》2012,287(19):15330-15344
S100 proteins promote cancer cell migration and metastasis. To investigate their roles in the process of migration we have constructed inducible systems for S100P in rat mammary and human HeLa cells that show a linear relationship between its intracellular levels and cell migration. S100P, like S100A4, differentially interacts with the isoforms of nonmuscle myosin II (NMIIA, K(d) = 0.5 μM; IIB, K(d) = 8 μM; IIC, K(d) = 1.0 μM). Accordingly, S100P dissociates NMIIA and IIC filaments but not IIB in vitro. NMIIA knockdown increases migration in non-induced cells and there is no further increase upon induction of S100P, whereas NMIIB knockdown reduces cell migration whether or not S100P is induced. NMIIC knockdown does not affect S100P-enhanced cell migration. Further study shows that NMIIA physically interacts with S100P in living cells. In the cytoplasm, S100P occurs in discrete nodules along NMIIA-containing filaments. Induction of S100P causes more peripheral distribution of NMIIA filaments. This change is paralleled by a significant drop in vinculin-containing, actin-terminating focal adhesion sites (FAS) per cell. The induction of S100P, consequently, causes significant reduction in cellular adhesion. Addition of a focal adhesion kinase (FAK) inhibitor reduces disassembly of FAS and thereby suppresses S100P-enhanced cell migration. In conclusion, this work has demonstrated a mechanism whereby the S100P-induced dissociation of NMIIA filaments leads to a weakening of FAS, reduced cell adhesion, and enhanced cell migration, the first major step in the metastatic cascade. 相似文献
188.
Salem ML Al-Khami AA El-Nagaar SA Zidan AA Al-Sharkawi IM Marcela Díaz-Montero C Cole DJ 《Cellular immunology》2012,276(1-2):67-74
Recently, we showed that post cyclophosphamide (CTX) microenvironment benefits the function of transferred T cells. Analysis of the kinetics of cellular recovery after CTX treatment showed that a single 4 mg/mouse CTX treatment decreased the absolute number of leukocytes in the peripheral blood (PBL) at days 3-15, and in the spleen and bone marrow (BM) at days 3-6. The absolute numbers of CD11c(+)CD11b(-) and CD11c(+)CD11b(+) dendritic cells (DCs), CD11b(+) and Ly6G(+) myeloid cells, T and B cells, CD4(+)CD25(+) T regulatory (T(reg)) cells, and NK1.1(+) cells also decreased. The cell numbers returned to control levels during the recovery phase. The absolute numbers of B cells remained low for 3 weeks. The numbers of DCs increased in PBL and spleen at day 9 but returned to control levels at day 15. These data indicate that CTX alters the cellular microenvironment in kinetics that might be precisely targeted to benefit the host. 相似文献
189.
Many genes associated with familial Parkinson's disease contribute to mitochondrial morphology and function. Some of these genes, for example, Pink1 and Parkin, are part of a common pathway. The presenilin-associated rhomboid-like (PARL) gene was recently linked to familial Parkinson's disease. The PARL gene product is found in the inner mitochondrial membrane and cleaves the optic atrophy 1 protein, involved in mitochondrial morphology and apoptosis. In Drosophila, the PARL-related rhomboid-7 gene acts upstream of pink1 and parkin. However, such a genetic relationship is still unknown in vertebrates. Here, we show that the zebrafish genome comprises two parl paralogs: parla and parlb. Morpholino-mediated loss of parla and/or parlb function resulted in mild neurodegeneration, as evidenced by a lower density of dopaminergic neurons. Patterning of dopaminergic neurons was also perturbed in the ventral diencephalon. Morphants exhibited extensive cell death throughout the entire body as well as increased larval mortality. The morphant phenotype could be rescued by injection of human PARL mRNA, but not catalytically inactive PARL, suggesting functional conservation between the human and zebrafish proteins. More importantly, the zebrafish pink1 mRNA as well as the human PINK1 mRNA, but not kinase-dead nor Parkinson's disease-linked mutant PINK1 mRNA, also rescued the morphant phenotype, providing evidence that Parl genes may function upstream of Pink1, as part of a conserved pathway in vertebrates. 相似文献
190.
Shahrizad Yusof Ahmad Ismail Tomoko Koito Masato Kinoshita Koji Inoue 《Environmental Biology of Fishes》2012,93(1):43-49
Among ricefishes of the genus Oryzias, the Javanese medaka (O. javanicus) and the Indian medaka (O. dancena) are highly adaptable to seawater. Although wide distribution of the two species in the brackish waters of South and South-East
Asia has been reported, their habitat preference remains unknown. We surveyed 12 sites in five estuarial areas of the west
coast of Peninsular Malaysia from Kuala Gula to Tanjung Piai. Both species were found in all five areas, suggesting their
distribution throughout the west coast of Peninsular Malaysia. This is the southernmost-recorded appearance of O. dancena, to the best of our knowledge. However, the habitats of the two species were essentially separated: of the 12 surveyed sites,
the species were found in co-existence at only two sites, and one or the other species was found alone at the remaining 10
sites. We compared temperature, salinity, pH, and dissolved oxygen (DO) at the sampling sites and found that the habitat of
O. javanicus is with higher salinity and DO. The salinity and DO at the sites of co-existence are near the lowest values found at the
O. javanicus-only sites, and the highest values at the O. dancena-only sites. These results suggest that O. javanicus and O. dancena habitats are essentially separated; the former prefers hyperosmotic conditions while the latter prefers hypoosmotic conditions,
and the latter may be more tolerant of hypoxia. The two sites of co-existence are points of contact between the species’ separate
distribution areas. 相似文献