全文获取类型
收费全文 | 555篇 |
免费 | 32篇 |
国内免费 | 4篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 19篇 |
2021年 | 17篇 |
2020年 | 15篇 |
2019年 | 20篇 |
2018年 | 27篇 |
2017年 | 16篇 |
2016年 | 34篇 |
2015年 | 41篇 |
2014年 | 39篇 |
2013年 | 26篇 |
2012年 | 38篇 |
2011年 | 39篇 |
2010年 | 25篇 |
2009年 | 20篇 |
2008年 | 30篇 |
2007年 | 27篇 |
2006年 | 18篇 |
2005年 | 19篇 |
2004年 | 17篇 |
2003年 | 16篇 |
2002年 | 11篇 |
2001年 | 9篇 |
2000年 | 7篇 |
1999年 | 3篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1983年 | 8篇 |
1981年 | 1篇 |
1978年 | 4篇 |
1977年 | 1篇 |
1975年 | 2篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1970年 | 1篇 |
1966年 | 2篇 |
排序方式: 共有591条查询结果,搜索用时 31 毫秒
21.
Luiz Claudio Pereira Ribeiro Cassia Cristina Alves Gon?alves Carla Maria Sena Andrade Slater Silvia Maia Farias de Carvalho Marzia Puccioni-Sohler 《Memórias do Instituto Oswaldo Cruz》2013,108(6):730-734
Intrathecal synthesis of human T-lymphotropic virus type 1 (HTLV-1) antibodies
(Abs) represents conclusive evidence of a specific immune response in the
central nervous system of HTLV-1 associated myelopathy/tropical spastic
paraparesis (HAM/TSP) patients. Western blotting (WB) for HTLV Abs in serum is a
confirmatory test for HTLV-1 infection. The aim of this study was to standardise
the Western blot to demonstrate the intrathecal pattern of Abs against HTLV-1
proteins in HAM/TSP patients. Paired cerebrospinal fluid (CSF) and serum samples
were selected from 20 patients with definite HAM/TSP, 19 HTLV-1 seronegative
patients and two HTLV-1 patients without definite HAM/TSP. The presence of
reactive bands of greater intensity in the CSF compared to serum (or bands in
only the CSF) indicated the intrathecal synthesis of anti-HTLV-1 Abs. All
definite HAM/TSP patients presented with an intrathecal synthesis of anti-HTLV-1
Abs; these Abs were not detected in the control patients. The most frequent
intrathecal targets of anti-HTLV-1 Abs were GD21, rgp46-I and p24 and, to a
lesser extent, p19, p26, p28, p32, p36, p53 gp21 and gp46. The intrathecal
immune response against env (GD21 and rgp46-I) and
gag (p24) proteins represents the most important humoral
pattern in HAM/TSP. This response may be used as a diagnostic marker,
considering the frequent association of intrathecal anti-HTLV-1 Ab synthesis
with HAM/TSP and the pathogenesis of this neurological disease. 相似文献
22.
23.
Daniel M. de Brito Vinicius Maracaja-Coutinho Savio T. de Farias Leonardo V. Batista Thaís G. do Rêgo 《PloS one》2016,11(1)
Genomic Islands (GIs) are regions of bacterial genomes that are acquired from other organisms by the phenomenon of horizontal transfer. These regions are often responsible for many important acquired adaptations of the bacteria, with great impact on their evolution and behavior. Nevertheless, these adaptations are usually associated with pathogenicity, antibiotic resistance, degradation and metabolism. Identification of such regions is of medical and industrial interest. For this reason, different approaches for genomic islands prediction have been proposed. However, none of them are capable of predicting precisely the complete repertory of GIs in a genome. The difficulties arise due to the changes in performance of different algorithms in the face of the variety of nucleotide distribution in different species. In this paper, we present a novel method to predict GIs that is built upon mean shift clustering algorithm. It does not require any information regarding the number of clusters, and the bandwidth parameter is automatically calculated based on a heuristic approach. The method was implemented in a new user-friendly tool named MSGIP—Mean Shift Genomic Island Predictor. Genomes of bacteria with GIs discussed in other papers were used to evaluate the proposed method. The application of this tool revealed the same GIs predicted by other methods and also different novel unpredicted islands. A detailed investigation of the different features related to typical GI elements inserted in these new regions confirmed its effectiveness. Stand-alone and user-friendly versions for this new methodology are available at http://msgip.integrativebioinformatics.me. 相似文献
24.
The anabolic action of intermittent parathyroid hormone on cortical bone depends partly on its ability to induce nitric oxide‐mediated vasorelaxation in BALB/c mice
下载免费PDF全文
![点击此处可从《Cell biochemistry and function》网站下载免费的PDF全文](/ch/ext_images/free.gif)
S Gohin A Carriero C Chenu AA Pitsillides TR Arnett M Marenzana 《Cell biochemistry and function》2016,34(2):52-62
There is strong evidence that vasodilatory nitric oxide (NO) donors have anabolic effects on bone in humans. Parathyroid hormone (PTH), the only osteoanabolic drug currently approved, is also a vasodilator. We investigated whether the NO synthase inhibitor L‐NAME might alter the effect of PTH on bone by blocking its vasodilatory effect. BALB/c mice received 28 daily injections of PTH[1–34] (80 µg/kg/day) or L‐NAME (30 mg/kg/day), alone or in combination. Hindlimb blood perfusion was measured by laser Doppler imaging. Bone architecture, turnover and mechanical properties in the femur were analysed respectively by micro‐CT, histomorphometry and three‐point bending. PTH increased hindlimb blood flow by >30% within 10 min of injection (P < 0.001). Co‐treatment with L‐NAME blocked the action of PTH on blood flow, whereas L‐NAME alone had no effect. PTH treatment increased femoral cortical bone volume and formation rate by 20% and 110%, respectively (P < 0.001). PTH had no effect on trabecular bone volume in the femoral metaphysis although trabecular thickness and number were increased and decreased by 25%, respectively. Co‐treatment with L‐NAME restricted the PTH‐stimulated increase in cortical bone formation but had no clear‐cut effects in trabecular bone. Co‐treatment with L‐NAME did not affect the mechanical strength in femurs induced by iPTH. These results suggest that NO‐mediated vasorelaxation plays partly a role in the anabolic action of PTH on cortical bone. © 2016 The Authors. Cell Biochemistry and Function published by John Wiley & Sons, Ltd. 相似文献
25.
26.
AA Smith 《Biotechnic & histochemistry》2016,91(6):396-400
One can determine the best dilution of a primary antibody for immunohistochemistry that uses horseradish peroxidase conjugated to a secondary antibody by testing increasing concentrations sequentially on the same tissue section. When the same tissue section is incubated repeatedly with increasing concentrations of primary antibodies to epithelial membrane antigen, smooth muscle α-actin, or vimentin using alkaline phosphatase conjugated to a secondary antibody as the reporter, the best staining was obtained with a less concentrated primary antibody than was optimal for a single staining test. The best concentration of primary antibody for single run staining using an alkaline phosphatase reporting system is usually four times the best concentration for staining with multiple runs. The optimal concentration can be determined by denaturing the residual alkaline phosphatase and extracting residual stain by incubating the section in 4:1 diglyme:phosphate buffered saline for 20 min at 80o C between tests of primary antibody concentrations. I tested the method for four chromogens from one supplier and one chromogen from a different supplier. 相似文献
27.
Reinaldo Farias Paiva de Lucena Elcida de Lima Araújo Ulysses Paulino de Albuquerque 《Economic botany》2007,61(4):347-361
This study investigated the use of woody plants by a rural community in an area of dry land Caatinga vegetation in northeastern Brazil. Information was obtained concerning this woody species with a diameter that is equal to or greater than 3 centimeters (cm) at soil level surveyed in 100 sample plots totaling 1 hectare (ha). The following question is the hypothesis we tested. Is a plant’s relative importance (as measured by its use value) related to its “apparency,” as measured by its abundance and ecological dominance? “Apparency” explains the use value of plants in four categories: medicinal, construction, fuel, and technology. The most important uses of woody plants are related to harvesting for energy and construction purposes. 相似文献
28.
Diogo Vieira Tibery Leandro Ambrósio Campos Caroline Barbosa Farias Mourão Steve Peigneur Andréa Cruz e Carvalho Jan Tytgat Elisabeth Ferroni Schwartz 《生物化学与生物物理学报:生物膜》2019,1861(1):142-150
To1, previously named Tc49b, is a peptide neurotoxin isolated from venom of the scorpion Tityus obscurus that is responsible for lethal human poisoning cases in the Brazilian Amazonian region. Previously, To1 was shown to be lethal to mice and to change Na+ permeation in cerebellum granular neurons from rat brain. In addition, To1 did not affect Shaker B K+ channels. Based on sequence similarities, To1 was described as a β-toxin. In the present work, To1 was purified from T. obscurus venom and submitted to an electrophysiological characterization in human and invertebrate NaV channels. The analysis of the electrophysiological experiments reveal that To1 enhances the open probability at more negative potentials of human NaV 1.3 and 1.6, of the insect channel BgNaV1 and of arachnid VdNaV1 channel. In addition, To1 reduces the peak of Na+ currents in some of the NaVs tested. These results support the classification of the To1 as a β-toxin. A structure and functional comparison to other β-toxins that share sequence similarity to To1 is also presented. 相似文献
29.
30.
Stela Lima Farias Miranda Jennifer Toledo Damasceno Marcelo Faveri Luciene Figueiredo Helio Doyle da Silva Severino Matias de Alencar Alencar 《Biofouling》2019,35(3):308-319
This study investigated the antimicrobial effects of the ethanolic extract of Brazilian red propolis (BRP) on multispecies biofilms. A seven-day-old subgingival biofilm with 32 species was grown in a Calgary device. Biofilms were treated with BRP (1,600, 800, 400 and 200?μg ml?1) twice a day for 1?min, starting from day 3. Chlorhexidine (0.12%) and dilution-vehicle were used as positive and negative controls, respectively. On day 7, metabolic activity and the microbial composition of the biofilms by DNA-DNA hybridization were determined. The viability data were analyzed by one-way ANOVA followed by Tukey’s post hoc, whereas the microbial composition data were transformed via BOX-COX and analyzed using Dunnett’s post hoc. BRP (1,600?μg ml?1) decreased biofilm metabolic activity by 45%, with no significant difference from chlorhexidine-treated samples. BRP (1,600?μg ml?1) and chlorhexidine significantly reduced levels of 14 bacterial species compared to the vehicle control. Taken together, BRP showed promising antimicrobial properties which may be useful in periodontal disease control. 相似文献