全文获取类型
收费全文 | 433篇 |
免费 | 18篇 |
国内免费 | 6篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 15篇 |
2021年 | 23篇 |
2020年 | 17篇 |
2019年 | 24篇 |
2018年 | 21篇 |
2017年 | 17篇 |
2016年 | 13篇 |
2015年 | 26篇 |
2014年 | 18篇 |
2013年 | 38篇 |
2012年 | 41篇 |
2011年 | 50篇 |
2010年 | 15篇 |
2009年 | 24篇 |
2008年 | 25篇 |
2007年 | 17篇 |
2006年 | 15篇 |
2005年 | 13篇 |
2004年 | 11篇 |
2003年 | 3篇 |
2002年 | 6篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1997年 | 2篇 |
1994年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1984年 | 2篇 |
1981年 | 1篇 |
1976年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有457条查询结果,搜索用时 15 毫秒
1.
Beneficial effects of n-hexane bark extract of Onosma echioides L. on diabetic peripheral neuropathy
Ambreen Shoaib Badruddeen Rakesh Kumar Dixit Magdah Ganash George Barreto Ghulam Md Ashraf Hefazat Hussain Siddiqui 《Journal of cellular biochemistry》2019,120(10):16524-16532
Onosma echioides Linn (Boraginaceae) is the most frequently used curative herb widely used for kidney obstruction, sciatic pain, and gout. The present study was designed to investigate the therapeutic effects of n-hexane bark extract of O. echioides (OE) L. root in vivo against Streptozotocin-induced diabetic neuropathy in SD rats. For in vivo activity, the experiment was categorized into five different groups (n = 5). Group-I was considered as nondiabetic/normal control (NC) treated with 0.5% carboxymethyl cellulose (CMC), Group II as diabetic control, Group-III, IV, and V served as diabetic treated with OE 50, OE 100, and pregabalin at a dose of 50, 100, and 10 mg/kg body weight, orally, respectively. Body weight, blood glucose, oral glucose tolerance test, behavioral studies (motor coordination test, thermal hyperalgesia, cold allodynia, locomotor activity, oxidative biomarkers (thio barbituric acid reactive substances [TBARS], superoxide dismutase [SOD], glutathione [GSH], and catalase), and histopathology of the sciatic nerve were performed. Treatment with OE showed a dose-dependent increase in neuroprotective activity by improving the myelination and decreasing the axonal swelling of nerve fibers. The verdicts of behavioral activities showed a remarkable effect on animals after the treatment of extract and standard drug pregabalin. In conclusion, our findings supported the traditional application of OE and explored its importance in the management of diabetic neuropathy. Additional clinical experiments may provide novel therapeutic drugs for diabetes and its complications. 相似文献
2.
Dieke Boezen Ghulam Ali Manli Wang Xi Wang Wopke van der Werf Just M. Vlak Mark P. Zwart 《PLoS genetics》2022,18(6)
Mutation rates are of key importance for understanding evolutionary processes and predicting their outcomes. Empirical mutation rate estimates are available for a number of RNA viruses, but few are available for DNA viruses, which tend to have larger genomes. Whilst some viruses have very high mutation rates, lower mutation rates are expected for viruses with large genomes to ensure genome integrity. Alphabaculoviruses are insect viruses with large genomes and often have high levels of polymorphism, suggesting high mutation rates despite evidence of proofreading activity by the replication machinery. Here, we report an empirical estimate of the mutation rate per base per strand copying (s/n/r) of Autographa californica multiple nucleopolyhedrovirus (AcMNPV). To avoid biases due to selection, we analyzed mutations that occurred in a stable, non-functional genomic insert after five serial passages in Spodoptera exigua larvae. Our results highlight that viral demography and the stringency of mutation calling affect mutation rate estimates, and that using a population genetic simulation model to make inferences can mitigate the impact of these processes on estimates of mutation rate. We estimated a mutation rate of μ = 1×10−7 s/n/r when applying the most stringent criteria for mutation calling, and estimates of up to μ = 5×10−7 s/n/r when relaxing these criteria. The rates at which different classes of mutations accumulate provide good evidence for neutrality of mutations occurring within the inserted region. We therefore present a robust approach for mutation rate estimation for viruses with stable genomes, and strong evidence of a much lower alphabaculovirus mutation rate than supposed based on the high levels of polymorphism observed. 相似文献
3.
Molecular cloning of enantioselective ester hydrolase from Bacillus pumilus DBRL-191 总被引:1,自引:0,他引:1
Rasool S Johri S Riyaz-ul-Hassan S Maqbool QU Verma V Koul S Taneja SC Qazi GN 《FEMS microbiology letters》2005,249(1):113-120
A gene from Bacillus pumilus expressed under its native promoter was cloned in Escherichia coli. Recombinant B. pumilus esterase (BPE) affects the kinetic resolution of racemic mixtures such as unsubstituted and substituted 1-(phenyl)ethanols (E approximately 33-103), ethyl 3-hydroxy-3-phenylpropanoate (E approximately 45-71), trans-4-fluorophenyl-3-hydroxymethyl-N-methylpiperidine (E approximately 10-13) and ethyl 2-hydroxy-4-phenylbutyrate (E approximately 7). The enzyme is composed of a 34-amino acid signal peptide and a 181-amino acid mature protein corresponding to a molecular weight of approximately 19.2kD and pI approximately 9.4. 3-D the structural model of the enzyme built by homology modelling using the atomic coordinates from the crystal structure of B. subtilis lipase (LipA) showed a compact minimal alpha/beta hydrolase fold. 相似文献
4.
Jianfan Sun Susan Rutherford Muhammad Saif Ullah Ikram Ullah Qaiser Javed Ghulam Rasool Muhammad Ajmal Ahmad Azeem Muhammad Junaid Nazir Daolin Du 《Journal of Plant Ecology》2022,15(3):610
生物入侵过程中的植物-土壤反馈:一种入侵植物的凋落物分解对其本地近缘植物的影响
植物入侵可通过正或负的植物-土壤反馈效应改变土壤的生物和非生物性质,从而影响入侵栖息地的土壤理化性质。许多入侵物种的凋落物分解可增加土壤养分,降低本地植物多样性,并导致进一步的植物入侵。关于入侵植物凋落物在不同土壤类型及深度分解及反馈效应的研究依然很少。本研究旨在明确入侵植物南美蟛蜞菊(Sphagneticola trilobata)凋落物在不同土壤类型和不同土壤深度条件下的分解情 况及其对本地近缘植物蟛蜞菊(S. calendulacea)生理生长的影响。将装有南美蟛蜞菊凋落物的尼龙袋加入到不同深度(即0、2、4 和6 cm)的砂土、营养土和粘土中,经6个月的分解后,回收凋落物袋并计算分解速率,随后在凋落物分解处理后的土壤中种植本地蟛蜞菊,并在生长期结束时测量其生理生态指标。研究结果表明,所有处理土壤类型中,凋落物在土壤深度为2和4 cm处分解后显著增加了土壤养分,而对本 地蟛蜞菊的叶片叶绿素、叶氮含量等生长指标表现为负效应。因此,入侵植物南美蟛蜞菊凋落物分解对土壤养分表现为正的反馈效应,而对本地植物蟛蜞菊的生长表现为负效应。我们的研究结果还表明,入侵植物的凋落物分解对土壤和本地物种的影响还因凋落物分解所在的土壤深度而显著不同。未来的研究应侧重于入侵栖息地中更多本地和入侵物种的植物-土壤反馈效应,以及更多土壤类型和土壤深度的入侵植物凋落物效应。 相似文献
5.
Mirani Abdul Aziz Teo Chee How Markhand Ghulam Sarwar Abul-Soad Adel Ahmed Harikrishna Jennifer Ann 《Plant Cell, Tissue and Organ Culture》2020,141(1):119-130
Plant Cell, Tissue and Organ Culture (PCTOC) - In vitro regeneration of date palm (Phoenix dactylifera L.) plants through somatic embryogenesis leads to the generation of somaclonal variants. The... 相似文献
6.
7.
Zahid H. Chohan Humayun Pervez A. Rauf Khalid M. Khan Ghulam M. Maharvi 《Journal of enzyme inhibition and medicinal chemistry》2013,28(2):161-168
A new series of antibacterial and antifungal triazine-derived mono- and di-substituted (symmetrical and unsymmetrical) Schiff-bases and their cobalt(II), copper(II), nickel(II) and zinc(II) metal complexes have been synthesized and characterized by their elemental analyses, molar conductances, magnetic moments and IR and electronic spectral measurements. IR spectra indicated the ligands to act as tridentate towards divalent metal ions via a trazine-N, the azomethine-N and, indole-NH and deprotonated-O of salicylaldehyde. The magnetic moments and electronic spectral data suggest octahedral geometry for the Co(II), Ni(II) and Zn(II)complexes and square-pyramid for Cu(II) complexes. NMR spectral data of the ligands and their diamagnetic zinc(II) complexes well-define their proposed structures/geometries. Elemental analyses data of the ligands and metal complexes agree with their proposed structures/geometries. The synthesized ligands, along with their metal complexes were screened for their antibacterial activity against Escherichia coli, Bacillus subtillis, Shigella flexneri, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi and for antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glaberata. The results of these studies show the metal complexes to be more antibacterial/antifungal against two or more species as compared to the uncomplexed Schiff-base ligands. 相似文献
8.
Objectives
To conduct a meta-analysis to quantify the real-world incidence of in-hospital or 30-day death or myocardial infarction (MI), and angiographically-confirmed ST-related treatment costs.Background
The short-term clinical and economic consequences of coronary stent thrombosis (ST) are thought to be significant.Methods
We searched MEDLINE, Embase and Scopus from January 2000-July 2012 to identify observational/registry studies that evaluated a cohort of ≥25 patients experiencing angiographically-confirmed thrombosis of a drug-eluting or bare-metal stent, required the use of dual-antiplatelet therapy for guideline-recommended durations, and reported incidences of in-hospital or 30-day death or MI and/or ST-related treatment costs. Incidences and costs from each study were pooled using random-effects meta-analysis.Results
Twenty-three studies were included. Of the 13 studies reporting in-hospital outcomes, 12 (N=8,832 STs) reported mortality data, with the pooled incidence rate estimated to be 7.9%, 95%CI=5.4%-11.3%, I2=86%. Ten studies (N=1,294 STs) reported 30-day death, with a pooled incidence of 11.6%, 95%CI=8.8%-15.1%, I2=55%. Patients experiencing early ST (within 30-days of implant) had higher in-hospital and 30-day mortality than those experiencing very-late ST (interaction p<0.04 for both). Stent type had no significant effect on in-hospital or 30-day mortality. In the 5 studies (N=542 STs) and 3 studies (N=180 STs) reporting in-hospital and 30-day MI, respectively, the pooled incidence rates were 6.1%, 95%CI=2.1%-16.2%, I2=88% and 9.5%, 95%CI=3.8%-22.0%, I2=65%. One study reported costs associated with ST, estimating the median/patient cost of hospitalization to treat early ST at $11,134 (in 2000US$).Conclusions
Regardless of stent type used, the short-term consequences of coronary ST appear significant. 相似文献9.
Ahmed M. Abu El-Asrar Ghulam Mohammad Mohd. Imtiaz Nawaz Mohammad Mairaj Siddiquei Kathleen Van den Eynde Ahmed Mousa Gert De Hertogh Ghislain Opdenakker 《PloS one》2013,8(12)
To investigate which matrix metalloproteinases (MMPs) are more likely to be involved in the angiogenic process in proliferative diabetic retinopathy (PDR), we measured the levels of MMPs in the vitreous fluid from patients with PDR and controls and correlated these levels with the levels of vascular endothelial growth factor (VEGF). Vitreous samples from 32 PDR and 24 nondiabetic patients were studied by mosaic multiplex MMPs enzyme-linked immunosorbent assay (ELISA), single ELISA, Western blot and zymography analysis. Epiretinal membranes from 11 patients with PDR were studied by immunohistochemistry. MMP-8 and MMP-13 were not detected. ELISA, Western blot and gelatin ymography assays revealed significant increases in the expression levels of MMP-1, MMP-7, MMP-9 and VEGF in vitreous samples from PDR patients compared to nondiabetic controls, whereas MMP-2 and MMP-3 were not upregulated in vitreous samples from PDR patients. Significant correlations existed between ELISA and zymography assays for the quantitation of MMP-2 (r=0.407; p=0.039) and MMP-9 (r=0.711; p<0.001). Significant correlations were observed between levels of VEGF and levels of MMP-1 (r=0.845; P<0.001) and MMP-9 (r=0.775; p<0.001), and between levels of MMP-1 and MMP-9 (r=0.857; p<0.001). In epiretinal membranes, cytoplasmic immunoreactivity for MMP-9 was present in vascular endothelial cells and stromal monocytes/macrophages and neutrophils. Our findings suggest that among the MMPs measured, MMP-1 and MMP-9 may contribute to the angiogenic switch in PDR. 相似文献
10.
Ghulam Hussain Florent Schmitt Alexandre Henriques Thiebault Lequeu Frederique Rene Fran?oise Bindler Sylvie Dirrig-Grosch Hugues Oudart Lavinia Palamiuc Marie-Helene Metz-Boutigue Luc Dupuis Eric Marchioni Jose-Luis Gonzalez De Aguilar Jean-Philippe Loeffler 《PloS one》2013,8(6)
The progressive deterioration of the neuromuscular axis is typically observed in degenerative conditions of the lower motor neurons, such as amyotrophic lateral sclerosis (ALS). Neurodegeneration in this disease is associated with systemic metabolic perturbations, including hypermetabolism and dyslipidemia. Our previous gene profiling studies on ALS muscle revealed down-regulation of delta-9 desaturase, or SCD1, which is the rate-limiting enzyme in the synthesis of monounsaturated fatty acids. Interestingly, knocking out SCD1 gene is known to induce hypermetabolism and stimulate fatty acid beta-oxidation. Here we investigated whether SCD1 deficiency can affect muscle function and its restoration in response to injury. The genetic ablation of SCD1 was not detrimental per se to muscle function. On the contrary, muscles in SCD1 knockout mice shifted toward a more oxidative metabolism, and enhanced the expression of synaptic genes. Repressing SCD1 expression or reducing SCD-dependent enzymatic activity accelerated the recovery of muscle function after inducing sciatic nerve crush. Overall, these findings provide evidence for a new role of SCD1 in modulating the restorative potential of skeletal muscles. 相似文献