全文获取类型
收费全文 | 744篇 |
免费 | 39篇 |
国内免费 | 4篇 |
出版年
2024年 | 2篇 |
2023年 | 6篇 |
2022年 | 14篇 |
2021年 | 34篇 |
2020年 | 11篇 |
2019年 | 40篇 |
2018年 | 36篇 |
2017年 | 14篇 |
2016年 | 29篇 |
2015年 | 37篇 |
2014年 | 41篇 |
2013年 | 38篇 |
2012年 | 52篇 |
2011年 | 58篇 |
2010年 | 37篇 |
2009年 | 26篇 |
2008年 | 29篇 |
2007年 | 41篇 |
2006年 | 28篇 |
2005年 | 27篇 |
2004年 | 25篇 |
2003年 | 18篇 |
2002年 | 15篇 |
2001年 | 18篇 |
2000年 | 9篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 7篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 3篇 |
1971年 | 3篇 |
1966年 | 2篇 |
1962年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有787条查询结果,搜索用时 31 毫秒
621.
Sayed M. Habib Alferso C. Abrahams Mario R. Korte Robert Zietse Lisette L. de Vogel Walther H. Boer Amélie Dendooven Marian C. Clahsen-van Groningen Michiel G. H. Betjes 《PloS one》2015,10(4)
Background
Encapsulating peritoneal sclerosis (EPS) is a severe complication of peritoneal dialysis (PD). Previously, it has been shown that infiltrating CD4-positive T cells and M2 macrophages are associated with several fibrotic conditions. Therefore, the characteristics of the peritoneal cell infiltrate in EPS may be of interest to understand EPS pathogenesis. In this study, we aim to elucidate the composition of the peritoneal cell infiltrate in EPS patients and relate the findings to clinical outcome.Study Design, Setting, and Participants
We studied peritoneal membrane biopsies of 23 EPS patients and compared them to biopsies of 15 PD patients without EPS. The cellular infiltrate was characterized by immunohistochemistry to detect T cells(CD3-positive), CD4-positive (CD4+) and CD8-positive T cell subsets, B cells(CD20-positive), granulocytes(CD15-positive), macrophages(CD68-positive), M1(CD80-positive), and M2(CD163-positive) macrophages. Tissues were analysed using digital image analysis. Kaplan-Meier survival analysis was performed to investigate the survival in the different staining groups.Results
The cellular infiltrate in EPS biopsies was dominated by mononuclear cells. For both CD3 and CD68, the median percentage of area stained was higher in biopsies of EPS as opposed to non-EPS patients (p<0.001). EPS biopsies showed a higher percentage of area stained for CD4 (1.29%(0.61-3.20)) compared to CD8 (0.71%(0.46-1.01), p = 0.04), while in the non-EPS group these cells were almost equally represented (respectively 0.28%(0.05-0.83) versus 0.22%(0.17-0.43), p = 0.97). The percentage of area stained for both CD80 and CD163 was higher in EPS than in non-EPS biopsies (p<0.001), with CD163+ cells being the most abundant phenotype. Virtually no CD20-positive and CD15-positive cells were present in biopsies of a subgroup of EPS patients. No relation was found between the composition of the mononuclear cell infiltrate and clinical outcome.Conclusions
A characteristic mononuclear cell infiltrate consisting of CD4+ and CD163+ cells dominates the peritoneum of EPS patients. These findings suggest a role for both CD4+ T cells and M2 macrophages in the pathogenesis of EPS. 相似文献622.
Muqader Shah Hafsa Zaneb Saima Masood Rifat Ullah Khan Muhammad Mobashar Imad Khan Salahud Din Muhammad Shoaib Khan Habib Ur Rehman Antonella Tinelli 《Probiotics and antimicrobial proteins》2020,12(2):473-480
Two-hundred-eighty-day-old broiler chicks were divided into seven groups. The groups were designated as T1, thermoneutral zone; T2, heat stressed (HS); T3, 相似文献
623.
Khajeh Kosar Aminfar Habib Masuda Yoshihiro Mohammadpourfard Mousa 《Journal of molecular modeling》2020,26(5):1-15
The mechanism of C-H bond activation of ethane was catalyzed by palladium halide cations (PdX+ (X = F, Cl, Br, H, and CH3)), which was investigated using density functional theory (DFT) at B3LYP level. The reaction mechanism was taken into account in triplet and singlet spin state potential energy surfaces. For PdF+, PdCl+, and PdBr+, the high spin states were the ground states, whereas the ground states were the low spin states in PdH+ and PdCH3+. The reaction of PdF+, PdCl+, and PdBr+ with ethane occurred via a typical “two-state reactivity” mechanism. In contrast, for PdH+ and PdCH3+, the overall reaction performed on the ground state PESs in a spin-conserving manner. The crossing points between two potential energy surfaces were observed and effectively decreased the activation barrier in PdX+/C2H6 (X = F, Cl, and Br). The minimum energy crossing points (MECP) were obtained used the algorithm in Harvey method. The natural valence electron configuration calculations were analyzed by natural bond orbital. The distribution and contribution of the front molecular orbital of the initial complexes could be further understand by the density of states. The feature of the bonding evolution in the main pathways was studied using topological analysis including localized orbital locator and atoms in molecules. 相似文献
624.
Baghban Roghayyeh Ghasemali Samaneh Farajnia Safar Hoseinpoor Reyhaneh Andarzi Sahar Zakariazadeh Mostafa Zarredar Habib 《International journal of peptide research and therapeutics》2021,27(4):2245-2256
International Journal of Peptide Research and Therapeutics - The vascular endothelial growth factor (VEGF) signaling pathway has a crucial role in regulating tumor angiogenesis. VEGF-A shows... 相似文献
625.
Habib Ul Hassan Qadeer Mohammad Ali Naveed Ahmad Zubia Masood Md. Yeamin Hossain Karim Gabol Wali Khan Muneer Hussain Amjad Ali Mohammad Attaullah Mustafa Kamal 《Saudi Journal of Biological Sciences》2021,28(2):1324-1330
One of the essential factors to be addressed in the development of aquaculture is the feeding regime. This study was investigated to assess the effects of feeding rate on growth performance, feed utilization, chemical body composition survival rate, cannibalism and morphological indices of Asian Seabass, Lates calcarifer. Intended for the trial, one hundred forty sea bass individuals with an average weight 5.47 ± 0.11 g were randomly distributed in 4 concrete tanks (914 cm × 183 cm 122 cm) each; length × width × depth) and volume 18,399 L, for total 68 days. The fishes were fed with a pelleted diet containing 46% crude protein for different feeding groups designated as (T1, T2, T3 and T4). The feed was supplied with a rate of (T1) 3%, (T2) 4%, (T3) 6%, and (T4) 9% of fish biomass per day and feeding frequency were maintained three times per day to all the groups. At the end of the trial water physicochemical parameters was in acceptable range for Asian sea bass growth. The average daily weight gain (g), weight gain (g) and specific growth rate (%) was significantly higher (p < 0.05) in T3 and T4 as compared to T1 and T2 group. The poorest feed conversion ratio was recorded in T1 group with 3% biomass per day. The cannibalism rate was significantly (p < 0.05) higher in T1 (3%) compared to T3 and T4 treatment. The morphological indices, condition factors (CF), viscerosomatic index and hepatosomatic index (HSI) was significantly higher in T4 group as compared to other treatments. The protein, moisture and ash contents of the whole biomass of the Asian sea bass were not significantly influenced by feeding rate. The fat levels in the fish bodies increased significantly (p < 0.05) with increasing feeding ratio. The phenomenal regression indicates that 6.5% feeding rate per day is optimum for best growth performance, survival and minimum cannibalism rate for Asian sea bass in captivity. The outcome of the finding will help in promotion for not only the coastal aquaculture in Pakistan abut also elsewhere. 相似文献
626.
In multipredator systems, group sizes of social carnivores are shaped by the asymmetric intraguild interactions. Subordinate social carnivores experience low recruitment rates as an outcome of predation pressure. In South and Southeast Asia, the Tiger (Panthera tigris), Dhole (Cuon alpinus), and Leopard (Panthera pardus) form a widely distributed sympatric guild of large carnivores, wherein tigers are the apex predators followed by dhole and leopard. In this study, we attempted to understand the variation in pack size of a social carnivore, the dhole, at two neighboring sites in the Central Indian landscape. We further evaluated local‐scale patterns of variation in pack size at a larger scale by doing a distribution‐wide assessment across the dhole ranging countries. At the local scale, we found an inverse relationship between the density of tiger and pack size of dhole while accounting for variability in resources and habitat heterogeneity. Larger dhole packs (16.8 ± 3.1) were observed at the site where the tiger density was low (0.46/100 km2), whereas a smaller pack size (6.4 ± 1.3) was observed in the site with high tiger density (5.36/100 km2). Our results for the distribution‐wide assessment were concordant with local‐scale results, showing a negative association of pack size with the tiger densities (effect size −0.77) and a positive association with the prey abundance (effect size 0.64). The study advances our understanding to answer the age‐old question of “what drives the pack size of social predators in a multipredator system?” This study also highlights the importance of understanding demographic responses of subordinate predator for varying competitor densities, often helpful in making informed decisions for conservation and management strategies such as population recovery and translocation of species. 相似文献
627.
Ma C Fan R Ahmad H Shi Q Comin-Anduix B Chodon T Koya RC Liu CC Kwong GA Radu CG Ribas A Heath JR 《Nature medicine》2011,17(6):738-743
Cellular immunity has an inherent high level of functional heterogeneity. Capturing the full spectrum of these functions requires analysis of large numbers of effector molecules from single cells. We report a microfluidic platform designed for highly multiplexed (more than ten proteins), reliable, sample-efficient (~1 × 10(4) cells) and quantitative measurements of secreted proteins from single cells. We validated the platform by assessment of multiple inflammatory cytokines from lipopolysaccharide (LPS)-stimulated human macrophages and comparison to standard immunotechnologies. We applied the platform toward the ex vivo quantification of T cell polyfunctional diversity via the simultaneous measurement of a dozen effector molecules secreted from tumor antigen-specific cytotoxic T lymphocytes (CTLs) that were actively responding to tumor and compared against a cohort of healthy donor controls. We observed profound, yet focused, functional heterogeneity in active tumor antigen-specific CTLs, with the major functional phenotypes quantitatively identified. The platform represents a new and informative tool for immune monitoring and clinical assessment. 相似文献
628.
Mustapha Gorai Mustapha Ennajeh Habib Khemira Mohamed Neffati 《Acta Physiologiae Plantarum》2011,33(3):963-971
The aim of this study was to investigate the effects of NaCl-salinity on the physiological attributes in common reed, Phragmites australis (Cav.) Trin. ex Steudel. Plants grew optimally under salinity treatment with standard nutrient solution without added salt
and at NaCl concentrations up to 100 mM. Applied for 21 days, NaCl-salinity (300 and 500 mM) caused a significant reduction
in growth allocation of all different tissues of P. australis. Shoot growth of reed plants displayed a highly significant correlation with plant–water relations and photosynthetic parameters.
The net photosynthetic rate and stomatal conductance of reed plants treated with NaCl-salinity at varying osmotic potential
(ψπ) of nutrient solutions were positively correlated, and the former variable also had a strong positive relationship with transpiration
rate. Leaf water potential and ψπ followed similar trends and declined significantly as ψπ of watering solutions was lowered. The increase in total inorganic nutrients resulting from increased Na+ and Cl− in all tissues and K+, Ca2+ and Mg2+ concentrations were maintained even at the most extreme salt concentration. Common reed exhibited high K+/Na+ and Ca2+/Na+ selectivity ratios over a wide range of salinities under NaCl-salinity. These findings suggest that reed plants were able
to adapt well to high salinities by lowering their leaf ψπ and the adjustment of osmotically active solutes in the leaves. 相似文献
629.
Basit S Lee K Habib R Chen L Umm-e-Kalsoom Santos-Cortez RL Azeem Z Andrade P Ansar M Ahmad W Leal SM 《Human genetics》2011,129(4):379-385
DFNB89 is a novel autosomal recessive nonsyndromic hearing impairment (ARNSHI) locus that was mapped to 16q21-q23.2. Linkage to the region was established by carrying out genome-wide linkage scans in two unrelated, consanguineous Pakistani families segregating ARNSHI. The maximum multipoint LOD score is 9.7 for both families and for each family, a significant maximum LOD score of 6.0 and 3.7 were obtained. The 3-unit support interval and the region of homozygosity for the two families extend from rs717293 (chr16: 62.1?Mb) to rs728929 (chr16: 78.2?Mb) and contain 16.1?Mb of sequence. A total of 146 genes are within the DFNB89 interval. Eight candidate genes, CALB2, CDH1, CDH3, CDH11, HAS3, NOB1, PLEKHG4 and SMPD3, were sequenced, but no potentially causal variants were discovered. DFNB89 is the second ARNSHI locus mapped to chromosome 16. 相似文献
630.