全文获取类型
收费全文 | 850篇 |
免费 | 160篇 |
国内免费 | 5篇 |
出版年
2023年 | 3篇 |
2022年 | 12篇 |
2021年 | 20篇 |
2020年 | 9篇 |
2019年 | 7篇 |
2018年 | 11篇 |
2017年 | 11篇 |
2016年 | 26篇 |
2015年 | 49篇 |
2014年 | 25篇 |
2013年 | 49篇 |
2012年 | 70篇 |
2011年 | 61篇 |
2010年 | 38篇 |
2009年 | 37篇 |
2008年 | 44篇 |
2007年 | 42篇 |
2006年 | 48篇 |
2005年 | 39篇 |
2004年 | 31篇 |
2003年 | 34篇 |
2002年 | 29篇 |
2001年 | 24篇 |
2000年 | 28篇 |
1999年 | 15篇 |
1998年 | 10篇 |
1997年 | 17篇 |
1996年 | 14篇 |
1995年 | 12篇 |
1994年 | 12篇 |
1993年 | 15篇 |
1992年 | 24篇 |
1991年 | 13篇 |
1990年 | 16篇 |
1989年 | 20篇 |
1988年 | 17篇 |
1987年 | 10篇 |
1986年 | 9篇 |
1985年 | 13篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1979年 | 8篇 |
1978年 | 3篇 |
1977年 | 6篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1973年 | 4篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1970年 | 2篇 |
排序方式: 共有1015条查询结果,搜索用时 250 毫秒
991.
992.
Mouna Haidar Monica Lam Berenice E. Chua Craig M. Smith Andrew L. Gundlach 《Neurochemical research》2016,41(3):481-491
Methamphetamine (METH) is a highly addictive psychostimulant, and cessation of use is associated with reduced monoamine signalling, and increased anxiety/depressive states. Neurons expressing the neuropeptide, relaxin-3 (RLN3), and its cognate receptor, RXFP3, constitute a putative ‘ascending arousal system’, which shares neuroanatomical and functional similarities with serotonin (5-HT)/dorsal raphe and noradrenaline (NA)/locus coeruleus monoamine systems. In light of possible synergistic roles of RLN3 and 5-HT/NA, endogenous RLN3/RXFP3 signalling may compensate for the temporary reduction in monoamine signalling associated with chronic METH withdrawal, which could alter the profile of ‘behavioural despair’, bodyweight reductions, and increases in anhedonia and anxiety-like behaviours observed following chronic METH administration. In studies to test this theory, Rln3 and Rxfp3 knockout (KO) mice and their wildtype (WT) littermates were injected once daily with saline or escalating doses of METH (2 mg/kg, i.p. on day 1, 4 mg/kg, i.p. on day 2 and 6 mg/kg, i.p. on day 3–10). WT and Rln3 and Rxfp3 KO mice displayed an equivalent sensitivity to behavioural despair (Porsolt swim) during the 2-day METH withdrawal and similar bodyweight reductions on day 3 of METH treatment. Furthermore, during a 3-week period after the cessation of chronic METH exposure, Rln3 KO, Rxfp3 KO and corresponding WT mice displayed similar behavioural responses in paradigms that measured anxiety (light/dark box, elevated plus maze), anhedonia (saccharin preference), and social interaction. These findings indicate that a whole-of-life deficiency in endogenous RLN3/RXFP3 signalling does not markedly alter behavioural sensitivity to chronic METH treatment or withdrawal, but leave open the possibility of a more significant interaction with global or localised manipulations of this peptide system in the adult brain. 相似文献
993.
Kia Joo Puan John Seng Hooi Low Terence Wee Kiat Tan Joseph Tien Seng Wee Eng Huat Tan Kam Weng Fong Eu Tiong Chua Chenggang Jin José-Luis Giner Craig T. Morita Christopher Hood Keng Goh Kam M. Hui 《Cancer immunology, immunotherapy : CII》2009,58(7):1095-1107
Introduction Human Vγ2Vδ2 T cells play important role in immunity to infection and cancer by monitoring self and foreign isoprenoid metabolites
with their γδ T cell antigen receptors. Like CD4 and CD8 αβ T cells, adult peripheral Vγ2Vδ2 T cells represent a pool of heterogeneous
cells with distinct functional capabilities.
Purpose The aim of this study was to characterize the phenotypes and functions of various Vγ2Vδ2 T cell subsets in patients with nasopharyngeal
carcinoma (NPC). We sought to develop a better understanding of the role of these cells during the course of disease and to
facilitate the development of immunotherapeutic strategies against NPC.
Results Although similar total percentages of peripheral blood Vγ2Vδ2 T cells were found in both NPC patients and normal donors, Vγ2Vδ2
T cells from NPC patients showed decreased cytotoxicity against tumor cells whereas Vγ2Vδ2 T cells from normal donors showed
potent cytotoxicity. To investigate further, we compared the phenotypic characteristics of Vγ2Vδ2 T cells from 96 patients
with NPC and 54 healthy controls. The fraction of late effector memory Vγ2Vδ2 T cells (TEM RA) was significantly increased in NPC patients with corresponding decreases in the fraction of early memory Vγ2Vδ2 T cells
(TCM) compared with those in healthy controls. Moreover, TEM RA and TCM Vγ2Vδ2 cells from NPC patients produced significantly less IFN-γ and TNF-α, potentially contributing to their impaired cytotoxicity.
Radiotherapy or concurrent chemo-radiotherapy further increased the TEM RA Vγ2Vδ2 T cell population but did not correct the impaired production of IFN-γ and TNF-α observed for TEM RA Vγ2Vδ2 T cells.
Conclusion We have identified distinct alterations in the Vγ2Vδ2 T cell subsets of patients with NPC. Moreover, the overall cellular
effector function of γδ T cells is compromised in these patients. Our data suggest that the contribution of Vγ2Vδ2 T cells
to control NPC may depend on the activation state and differentiation of these cells.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
994.
995.
Chua Thia-Eng 《Hydrobiologia》1997,352(1-3):159-166
Coastal environmental management requires timely and appropriate policy, management and technological interventions to address
a host of interrelated environmental problems arising from unplanned and unregulated coastal developments. These interventions
can only be effective if they are based on sound scientific (including socioeconomic) information. Thus, science plays a significant
role in the environmental management of coastal and marine areas.
This paper highlights the essential components of environmental coastal management that require scientific interventions,
particularly in providing the scientific basis for policy interventions, and preventive and/or mitigating measures. The integration
and packaging of scientific information for management actions require an interdisciplinary effort to address identified management
problems. Scientific research should respond to management needs and make contributions to the better understanding of ecosystems
and their responses to human interventions. Scientific information urgently required for management includes an understanding
of interactions in coastal resource systems, identification, evaluation and prioritization of management issues, management
strategies and actions, and development of methodologies and tools for environmental management. Obstacles to management-oriented
research have also been identified to include defective perception among scientists, defective communication between scientists
and decision makers, intellectual and cultural arrogance, and inadequate technical and management capability at the local
level.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
996.
Yong Hoi-Sen Chua Kah-Ooi Song Sze-Looi Liew Yvonne Jing-Mei Eamsobhana Praphathip Chan Kok-Gan 《Molecular biology reports》2021,48(8):6047-6056
Molecular Biology Reports - Tephritid fruit flies of the genus Dacus are members of the tribe Dacini, subfamily Dacinae. There are some 274 species worldwide, distributed in Africa and the... 相似文献
997.
998.
Genetic variation due to heavy metal contamination has always been an interesting topic of study. Because of the numerous
contaminants being found in coastal and intertidal waters, there is always much discussion and argument as to which contaminant(s)
caused the variations in the genetic structures of biomonitors. This study used a Single Primer Amplification Reaction (SPAR)
technique, namely Random Amplified Polymorphic DNA (RAPD), to determine the genetic diversity of the populations of the green-lipped
mussel Perna viridis collected from a metal-contaminated site at Kg. Pasir Puteh and those from four relatively uncontaminated sites (reference
sites). Heavy metal levels (Cd, Cu, Pb, and Zn) were also measured in the soft tissues and byssus of the mussels from all
the sites. Cluster analyses employing UPGMA based on the RAPD markers grouped the populations into two major clusters; the
Bagan Tiang, Pantai Lido, Pontian, and Kg. Pasir Puteh populations were in one cluster, while the Sg. Belungkor population
clustered by itself. This indicated that the genetic diversity based on bands resulting from the use of all four RAPD primers
on P. viridis did not indicate its potential use as a biomarker of heavy metal pollution in coastal waters. However, based on a correlation
analysis between a particular metal and a band resulting from a specific RAPD primer revealed some significant (P < 0.01) correlations between the primers and the heavy metal concentrations in the byssus and soft tissues. Thus, the correlation
between a particular metal and the bands resulting from the use of a specific RAPD primer on P. viridis could be used as biomonitoring tool of heavy metal pollution.
The text was submitted by the authors in English. 相似文献
999.
Cryopreserved (CryoPA) and Glycerol-preserved (GPA) skin allografts are commonly used in the treatment of severe burn injuries. However, comparable data on their differences in clinical outcome is scarce. This retrospective review aims to study the effect of allograft viability on clinical outcomes. The records of 48 severe burn patients who either received CryoPA or GPA were reviewed. Key burn mortality determinants were used to match the 2 groups. Clinical outcomes such as mortality rate (MR) and the length of hospital stay (LOS) were obtained. A separate in vitro comparison included histological assessments and the use of tetrazolium reductase activity to compare tissue viability. Both groups showed a comparable profile in burn mortality determinants. Patients who received CryoPA had a lower MR of 25% compared to 34.8% (P?=?0.250) in the GPA group and a lower LOS of 39.2?C45.9?days (P?=?0.730), respectively. The histological structural integrity was found to be well preserved with both methods although CryoPA was confirmed to be the more viable product (P?<?0.05). The lower MR associated with CryoPA cannot be totally ignored. However, the mechanism through which viable skin allografts improves MR of severe burns patients remains to be elucidated. 相似文献
1000.
The determination of the physical map of human chromosome 11 will require more clones than are currently available. We have isolated an additional 1001 new markers in a bacteriophage vector from a somatic cell hybrid cell line that contains most of chromosome 11, except the middle of the short arm. These markers were localized to five different regions, 11p15-pter, 11p12-cen, 11q11-q14, 11q14-q23, and 11q23-qter, by a panel of previously characterized somatic cell hybrids. The region 11q11-14 harbors genes that have been shown to be important in breast cancer, B-cell lymphomas, centrocytic lymphomas, asthma, and multiple endocrine neoplasia, type 1 (MEN1). To determine the positions of the recombinant clones located there, we developed a new series of radiation-reduced somatic cell hybrids. These hybrids, together with those previously characterized, allowed us to map the 11q11-q14 markers into 11 separate segregation groups. 相似文献