全文获取类型
收费全文 | 461篇 |
免费 | 47篇 |
出版年
2023年 | 3篇 |
2022年 | 13篇 |
2021年 | 18篇 |
2020年 | 12篇 |
2019年 | 8篇 |
2018年 | 25篇 |
2017年 | 16篇 |
2016年 | 24篇 |
2015年 | 27篇 |
2014年 | 28篇 |
2013年 | 33篇 |
2012年 | 40篇 |
2011年 | 44篇 |
2010年 | 31篇 |
2009年 | 19篇 |
2008年 | 22篇 |
2007年 | 22篇 |
2006年 | 12篇 |
2005年 | 15篇 |
2004年 | 10篇 |
2003年 | 12篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 7篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 7篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1966年 | 1篇 |
1916年 | 1篇 |
排序方式: 共有508条查询结果,搜索用时 46 毫秒
41.
A single dose of S‐ketamine induces long‐term antidepressant effects and decreases oxidative stress in adulthood rats following maternal deprivation
下载免费PDF全文
![点击此处可从《Developmental neurobiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Gislaine Z. Réus Anelise S. Carlessi Stephanie E. Titus Helena M. Abelaira Zuleide M. Ignácio Jaine R. da Luz Beatriz I. Matias Livia Bruchchen Drielly Florentino Andriele Vieira Fabricia Petronilho João Quevedo 《Developmental neurobiology》2015,75(11):1268-1281
Ketamine, an antagonist of N‐methyl‐d ‐aspartate receptors, has produced rapid antidepressant effects in patients with depression, as well as in animal models. However, the extent and duration of the antidepressant effect over longer periods of time has not been considered. This study evaluated the effects of single dose of ketamine on behavior and oxidative stress, which is related to depression, in the brains of adult rats subjected to maternal deprivation. Deprived and nondeprived Wistar rats were divided into four groups nondeprived + saline; nondeprived + S‐ketamine (15 mg/kg); deprived + saline; deprived + S‐ketamine (15 mg/kg). A single dose of ketamine or saline was administrated during the adult phase, and 14 days later depressive‐like behavior was assessed. In addition, lipid damage, protein damage, and antioxidant enzyme activities were evaluated in the rat brain. Maternal deprivation induces a depressive‐like behavior, as verified by an increase in immobility and anhedonic behavior. However, a single dose of ketamine was able to reverse these alterations, showing long‐term antidepressant effects. The brains of maternally deprived rats had an increase in protein oxidative damage and lipid peroxidation, but administration of a single dose of ketamine reversed this damage. The activities of antioxidant enzymes superoxide dismutase and catalase were reduced in the deprived rat brains. However, ketamine was also able to reverse these changes. In conclusion, these findings indicate that a single dose of ketamine is able to induce long‐term antidepressant effects and protect against neural damage caused by oxidative stress in adulthood rats following maternal deprivation. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 75: 1268–1281, 2015 相似文献
42.
Pablo Suárez Cleusa Yoshiko Nagamachi Cecilia Lanzone Matias Maximiliano Malleret Patricia Caroline Mary O’Brien Malcolm Andrew Ferguson-Smith Julio Cesar Pieczarka 《PloS one》2015,10(12)
Sigmodontinae rodents represent one of the most diverse and complex components of the mammalian fauna of South America. Among them most species belongs to Oryzomyini and Akodontini tribes. The highly specific diversification observed in both tribes is characterized by diploid complements, which vary from 2n = 10 to 86. Given this diversity, a consistent hypothesis about the origin and evolution of chromosomes depends on the correct establishment of synteny analyzed in a suitable phylogenetic framework. The chromosome painting technique has been particularly useful for identifying chromosomal synteny. In order to extend our knowledge of the homeological relationships between Akodontini and Oryzomyini species, we analyzed the species Akodon montensis (2n = 24) and Thaptomys nigrita (2n = 52) both from the tribe Akodontini, with chromosome probes of Hylaeamys megacephalus (2n = 54) of the tribe Oryzomyini. The results indicate that at least 12 of the 26 autosomes of H. megacephalus show conserved synteny in A. montensis and 14 in T. nigrita. The karyotype of Akodon montensis, as well as some species of the Akodon cursor species group, results from many chromosomal fusions and therefore the syntenic associations observed probably represent synapomorphies. Our finding of a set of such associations revealed by H. megacephalus chromosome probes (6/21; 3/25; 11/16/17; and, 14/19) provides phylogenetic information for both tribes. An extension of these observations to other members of Akodontini and Oryzomyini tribes should improve our knowledge about chromosome evolution in both these groups. 相似文献
43.
Valeria Castelletto Ian W. Hamley Teck Lim Matias B. De Tullio Eduardo M. Castaño 《Journal of peptide science》2010,16(9):443-450
We study the complex formation of a peptide βAβAKLVFF, previously developed by our group, with Aβ(1–42) in aqueous solution. Circular dichroism spectroscopy is used to probe the interactions between βAβAKLVFF and Aβ(1–42), and to study the secondary structure of the species in solution. Thioflavin T fluorescence spectroscopy shows that the population of fibers is higher in βAβAKLVFF/Aβ(1–42) mixtures compared to pure Aβ(1–42) solutions. TEM and cryo‐TEM demonstrate that co‐incubation of βAβAKLVFF with Aβ(1–42) causes the formation of extended dense networks of branched fibrils, very different from the straight fibrils observed for Aβ(1–42) alone. Neurotoxicity assays show that although βAβAKLVFF alters the fibrillization of Aβ(1–42), it does not decrease the neurotoxicity, which suggests that toxic oligomeric Aβ(1–42) species are still present in the βAβAKLVFF/Aβ(1–42) mixtures. Our results show that our designed peptide binds to Aβ(1–42) and changes the amyloid fibril morphology. This is shown to not necessarily translate into reduced toxicity. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
44.
Matias Pasquali Hedvig Komjati David Lee Rosemary Bayles 《Journal of Phytopathology》2010,158(10):708-711
Wheat stripe rust, caused by the fungal pathogen Puccinia striiformis f.sp. tritici (PST), is a major disease of wheat in temperate‐cold climates. The identification of new markers would ease the procedure for evaluating the ongoing pathogen evolution. Twelve single pustule isolates were generated from samples of PST obtained in UK during 1987–2001. They were evaluated for their pathogenic behaviour on a set of differential cultivars and were analysed by sequence‐related amplified polymorphisms (SRAP) technique, to identify polymorphisms useful to evaluate variability among isolates. This is the first report of the application of SRAP technique to Uredinales order. 相似文献
45.
The diet and breeding ecology of Yellow-legged Gulls (Larus michahellis atlantis) were studied on Selvagem Grande, North Atlantic in the nesting season of 2007. We collected and analyzed 715 pellets from
adults. The most frequent prey were White-faced Storm-petrels (Pelagodroma marina; present on 40.8% of all pellets) and the endemic land snails (Theba macandrewiana; present on 36.5% of all pellets). Other birds, namely Cory’s Shearwaters (Calonectris diomedea), Macaronesian Shearwaters (Puffinus assimilis), Bulwer’s Petrels (Bulweria bulwerii), and Band-rumped Storm-petrels (Oceanodroma castro) were relatively less frequent, but overall, seabirds were present in ca. 50% of all pellets, representing an estimated 60.4%
of all mass consumed by gulls. We estimate that the contribution of seabirds to the overall caloric balance accounted for
82.5% of all energy consumed. The number of gull pairs breeding on Selvagem Grande was 12 on 2005 and 2007. Breeding success
was low (0.92 and 0.25 juveniles per breeding pair, respectively). Using a simple bioenergetics model, we estimate the breeding
gull population to have the potential to consume approximately 4,847 adult/sub-adult seabirds in 3.5 months in order to meet
its energetic requirements. The importance of the estimated predation levels is discussed and some management actions are
suggested. 相似文献
46.
Bezerra GA Oliveira TM Moreno FB de Souza EP da Rocha BA Benevides RG Delatorre P de Azevedo WF Cavada BS 《Journal of structural biology》2007,160(2):168-176
Plant lectins, especially those purified from species of the Leguminosae family, represent the best studied group of carbohydrate-binding proteins. The legume lectins from Diocleinae subtribe are highly similar proteins that present significant differences in the potency/efficacy of their biological activities. The structural studies of the interactions between lectins and sugars may clarify the origin of the distinct biological activities observed in this high similar class of proteins. In this way, this work presents a crystallographic study of the ConM and CGL (agglutinins from Canavalia maritima and Canavalia gladiata, respectively) in the following complexes: ConM/CGL:Man(alpha1-2)Man(alpha1-O)Me, ConM/CGL:Man(alpha1-3)Man(alpha1-O)Me and ConM/CGL:Man(alpha1-4)Man(alpha1-O)Me, which crystallized in different conditions and space group from the native proteins. The structures were solved by molecular replacement, presenting satisfactory values for R(factor) and R(free). Comparisons between ConM, CGL and ConA (Canavalia ensiformis lectin) binding mode with the dimannosides in subject, presented different interactions patterns, which may account for a structural explanation of the distincts biological properties observed in the lectins of Diocleinae subtribe. 相似文献
47.
M. Arménia Carrondo Isabel Bento Pedro M. Matias Peter F. Lindley 《Journal of biological inorganic chemistry》2007,12(4):429-442
The interaction of dioxygen with iron plays a key role in many important biological processes, such as dioxygen transport
in the bloodstream and the reduction of dioxygen by iron in respiration. However, the catalytic mechanisms employed, for example
in ligand oxidation, are not fully understood at the current time despite intensive biochemical, spectroscopic and structural
studies. This review outlines the structural evidence obtained by X-ray crystallographic methods for the nature of the interactions
between dioxygen and the metal in iron-containing proteins. Proteins involved in iron transport or electron transfer are not
included. 相似文献
48.
49.
Stefano Perni Kurt C. Marsden Matias Escobar Stephen Hollingworth Stephen M. Baylor Clara Franzini-Armstrong 《The Journal of general physiology》2015,145(3):173-184
The ryanodine receptor (RyR)1 isoform of the sarcoplasmic reticulum (SR) Ca2+ release channel is an essential component of all skeletal muscle fibers. RyR1s are detectable as “junctional feet” (JF) in the gap between the SR and the plasmalemma or T-tubules, and they are required for excitation–contraction (EC) coupling and differentiation. A second isoform, RyR3, does not sustain EC coupling and differentiation in the absence of RyR1 and is expressed at highly variable levels. Anatomically, RyR3 expression correlates with the presence of parajunctional feet (PJF), which are located on the sides of the SR junctional cisternae in an arrangement found only in fibers expressing RyR3. In frog muscle fibers, the presence of RyR3 and PJF correlates with the occurrence of Ca2+ sparks, which are elementary SR Ca2+ release events of the EC coupling machinery. Here, we explored the structural and functional roles of RyR3 by injecting zebrafish (Danio rerio) one-cell stage embryos with a morpholino designed to specifically silence RyR3 expression. In zebrafish larvae at 72 h postfertilization, fast-twitch fibers from wild-type (WT) tail muscles had abundant PJF. Silencing resulted in a drop of the PJF/JF ratio, from 0.79 in WT fibers to 0.03 in the morphants. The frequency with which Ca2+ sparks were detected dropped correspondingly, from 0.083 to 0.001 sarcomere−1 s−1. The few Ca2+ sparks detected in morphant fibers were smaller in amplitude, duration, and spatial extent compared with those in WT fibers. Despite the almost complete disappearance of PJF and Ca2+ sparks in morphant fibers, these fibers looked structurally normal and the swimming behavior of the larvae was not affected. This paper provides important evidence that RyR3 is the main constituent of the PJF and is the main contributor to the SR Ca2+ flux underlying Ca2+ sparks detected in fully differentiated frog and fish fibers. 相似文献
50.