全文获取类型
收费全文 | 461篇 |
免费 | 52篇 |
出版年
2021年 | 12篇 |
2020年 | 7篇 |
2019年 | 11篇 |
2018年 | 5篇 |
2017年 | 5篇 |
2016年 | 13篇 |
2015年 | 22篇 |
2014年 | 12篇 |
2013年 | 15篇 |
2012年 | 25篇 |
2011年 | 20篇 |
2010年 | 14篇 |
2009年 | 15篇 |
2008年 | 23篇 |
2007年 | 23篇 |
2006年 | 28篇 |
2005年 | 17篇 |
2004年 | 15篇 |
2003年 | 22篇 |
2002年 | 31篇 |
2001年 | 12篇 |
2000年 | 12篇 |
1999年 | 8篇 |
1998年 | 13篇 |
1996年 | 5篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 7篇 |
1991年 | 5篇 |
1990年 | 8篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1980年 | 4篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1973年 | 7篇 |
1972年 | 6篇 |
1971年 | 5篇 |
1969年 | 4篇 |
1968年 | 3篇 |
1965年 | 3篇 |
排序方式: 共有513条查询结果,搜索用时 31 毫秒
461.
Nitzan Soffer Marilyn E Brandt Adrienne MS Correa Tyler B Smith Rebecca Vega Thurber 《The ISME journal》2014,8(2):271-283
White plague (WP)-like diseases of tropical corals are implicated in reef decline worldwide, although their etiological cause is generally unknown. Studies thus far have focused on bacterial or eukaryotic pathogens as the source of these diseases; no studies have examined the role of viruses. Using a combination of transmission electron microscopy (TEM) and 454 pyrosequencing, we compared 24 viral metagenomes generated from Montastraea annularis corals showing signs of WP-like disease and/or bleaching, control conspecific corals, and adjacent seawater. TEM was used for visual inspection of diseased coral tissue. No bacteria were visually identified within diseased coral tissues, but viral particles and sequence similarities to eukaryotic circular Rep-encoding single-stranded DNA viruses and their associated satellites (SCSDVs) were abundant in WP diseased tissues. In contrast, sequence similarities to SCSDVs were not found in any healthy coral tissues, suggesting SCSDVs might have a role in WP disease. Furthermore, Herpesviridae gene signatures dominated healthy tissues, corroborating reports that herpes-like viruses infect all corals. Nucleocytoplasmic large DNA virus (NCLDV) sequences, similar to those recently identified in cultures of Symbiodinium (the algal symbionts of corals), were most common in bleached corals. This finding further implicates that these NCLDV viruses may have a role in bleaching, as suggested in previous studies. This study determined that a specific group of viruses is associated with diseased Caribbean corals and highlights the potential for viral disease in regional coral reef decline. 相似文献
462.
Production of the virus‐like particles of nipah virus matrix protein in Pichia pastoris as diagnostic reagents
下载免费PDF全文
![点击此处可从《Biotechnology progress》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Narcisse MS Joseph Kok Lian Ho Beng Ti Tey Chon Seng Tan Norazizah Shafee Wen Siang Tan 《Biotechnology progress》2016,32(4):1038-1045
The matrix (M) protein of Nipah virus (NiV) is a peripheral protein that plays a vital role in the envelopment of nucleocapsid protein and acts as a bridge between the viral surface and the nucleocapsid proteins. The M protein is also proven to play an important role in production of virus‐like particles (VLPs) and is essential for assembly and budding of NiV particles. The recombinant M protein produced in Escherichia coli assembled into VLPs in the absence of the viral surface proteins. However, the E. coli produced VLPs are smaller than the native virus particles. Therefore, the aims of this study were to produce NiV M protein in Pichia pastoris, to examine the structure of the VLPs formed, and to assess the potential of the VLPs as a diagnostic reagent. The M protein was successfully expressed in P. pastoris and was detected with anti‐myc antibody using Western blotting. The VLPs formed by the recombinant M protein were purified with sucrose density gradient ultracentrifugation, high‐performance liquid chromatography (HPLC), and Immobilized Metal Affinity Chromatography (IMAC). Immunogold staining and transmission electron microscopy confirmed that the M protein assembled into VLPs as large as 200 nm. ELISA revealed that the NiV M protein produced in P. pastoris reacted strongly with positive NiV sera demonstrating its potential as a diagnostic reagent. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1038–1045, 2016 相似文献
463.
I Meral M Esrefoglu KA Dar S Ustunova MS Aydin M Demirtas 《Biotechnic & histochemistry》2016,91(8):493-500
We investigated the effects of Nigella sativa on apoptosis and gamma-aminobutyric acid (GABAA) receptor density in cerebral cortical and hippocampal neurons in a pentylenetetrazol (PTZ)-induced kindling model in rats. The PTZ kindling model was produced by injecting PTZ in subconvulsive doses to rats on days 1, 3, 5, 8, 10, 12, 15, 17, 19, 22 and 24 of the study into animals of PTZ treated (PTZ) and PTZ + N. sativa treated (PTZ + NS) groups. Clonic and tonic seizures were induced by injecting a convulsive dose of PTZ on day 26 of the study. Rats in the PTZ + NS group were treated also with a 10 mg/kg methanolic extract of N. sativa 2 h before each PTZ injection. Rats in the control group were treated with 4 ml/kg saline. The number of neurons that expressed GABAA receptors in the hippocampus and cerebral cortex of rats in the PTZ and PTZ + NS groups increased significantly. There was no significant difference in the number of GABAA receptors between the PTZ and PTZ + NS groups. GABAA receptor density of the neurons in the cerebral cortex, but not hippocampus, was increased in PTZ group compared to controls. We observed a significant increase in the number of apoptotic neurons in the cerebral cortex of rats of both the PTZ and PTZ + NS groups compared to controls. We observed a significant decrease in the number of the apoptotic neurons in the cerebral cortex of rats in the PTZ + NS group compared to the PTZ group. N. sativa treatment ameliorated the PTZ induced neurodegeneration in the cerebral cortex as reflected by neuronal apoptosis and neuronal GABAA receptor frequency. 相似文献
464.
465.
Rostène W 《Journal de la Société de Biologie》2006,200(3):245-250
Paul Bert worked with Claude Bernard, one of the leading physiologists of the 19th century. In his laboratory at the Collège de France in Paris, Paul Bert carried out fascinating experiments in particular on respiratory processes, leading him to publish "La pression barométrique" in 1878. In this book are recalled his discovery of oxygen pressure decrease with altitude, divers diseases, the improved safety protocols in hyperbaric conditions, and the first development of gas anaesthetics for surgery. He was the third President of the Société de Biologie. Paul Bert was also a politician with strong convictions. Minister of Education under Gambetta's short term government, he initiated the fight for social equality and secular education and became one of the most prestigious figures of the developing socialist party. He received many distinctions and was given a state funeral. 相似文献
466.
A model diagram layout extension for SBML 总被引:1,自引:0,他引:1
467.
Experimental high-throughput studies of protein-protein interactions are beginning to provide enough data for comprehensive computational studies. Today, about ten large data sets, each with thousands of interacting pairs, coarsely sample the interactions in fly, human, worm, and yeast. Another about 55,000 pairs of interacting proteins have been identified by more careful, detailed biochemical experiments. Most interactions are experimentally observed in prokaryotes and simple eukaryotes; very few interactions are observed in higher eukaryotes such as mammals. It is commonly assumed that pathways in mammals can be inferred through homology to model organisms, e.g. the experimental observation that two yeast proteins interact is transferred to infer that the two corresponding proteins in human also interact. Two pairs for which the interaction is conserved are often described as interologs. The goal of this investigation was a large-scale comprehensive analysis of such inferences, i.e. of the evolutionary conservation of interologs. Here, we introduced a novel score for measuring the overlap between protein-protein interaction data sets. This measure appeared to reflect the overall quality of the data and was the basis for our two surprising results from our large-scale analysis. Firstly, homology-based inferences of physical protein-protein interactions appeared far less successful than expected. In fact, such inferences were accurate only for extremely high levels of sequence similarity. Secondly, and most surprisingly, the identification of interacting partners through sequence similarity was significantly more reliable for protein pairs within the same organism than for pairs between species. Our analysis underlined that the discrepancies between different datasets are large, even when using the same type of experiment on the same organism. This reality considerably constrains the power of homology-based transfer of interactions. In particular, the experimental probing of interactions in distant model organisms has to be undertaken with some caution. More comprehensive images of protein-protein networks will require the combination of many high-throughput methods, including in silico inferences and predictions. http://www.rostlab.org/results/2006/ppi_homology/ 相似文献
468.
469.
Sherif M Amr Ashraf N Moharram Kamal MS Abdel-Meguid 《Journal of brachial plexus and peripheral nerve injury》2006,1(1):1-12
Objective
The effect of end-to-side neurotization of partially regenerated recipient nerves on improving motor power in late obstetric brachial plexus lesions, so-called nerve augmentation, was investigated.Methods
Eight cases aged 3 – 7 years were operated upon and followed up for 4 years (C5,6 rupture C7,8T1 avulsion: 5; C5,6,7,8 rupture T1 avulsion:1; C5,6,8T1 rupture C7 avulsion:1; C5,6,7 ruptureC8 T1 compression: one 3 year presentation after former neurotization at 3 months). Grade 1–3 muscles were neurotized. Grade0 muscles were neurotized, if the electromyogram showed scattered motor unit action potentials on voluntary contraction without interference pattern. Donor nerves included: the phrenic, accessory, descending and ascending loops of the ansa cervicalis, 3rd and 4th intercostals and contralateral C7.Results
Superior proximal to distal regeneration was observed firstly. Differential regeneration of muscles supplied by the same nerve was observed secondly (superior supraspinatus to infraspinatus regeneration). Differential regeneration of antagonistic muscles was observed thirdly (superior biceps to triceps and pronator teres to supinator recovery). Differential regeneration of fibres within the same muscle was observed fourthly (superior anterior and middle to posterior deltoid regeneration). Differential regeneration of muscles having different preoperative motor powers was noted fifthly; improvement to Grade 3 or more occurred more in Grade2 than in Grade0 or Grade1 muscles. Improvements of cocontractions and of shoulder, forearm and wrist deformities were noted sixthly. The shoulder, elbow and hand scores improved in 4 cases.Limitations
The sample size is small. Controls are necessary to rule out any natural improvement of the lesion. There is intra- and interobserver variability in testing muscle power and cocontractions.Conclusion
Nerve augmentation improves cocontractions and muscle power in the biceps, pectoral muscles, supraspinatus, anterior and lateral deltoids, triceps and in Grade2 or more forearm muscles. As it is less expected to improve infraspinatus power, it should be associated with a humeral derotation osteotomy and tendon transfer. Function to non improving Grade 0 or 1 forearm muscles should be restored by muscle transplantation.Level of evidence
Level IV, prospective case series. 相似文献470.