全文获取类型
收费全文 | 5097篇 |
免费 | 330篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 100篇 |
妇产科学 | 63篇 |
基础医学 | 780篇 |
口腔科学 | 43篇 |
临床医学 | 498篇 |
内科学 | 1269篇 |
皮肤病学 | 37篇 |
神经病学 | 507篇 |
特种医学 | 275篇 |
外科学 | 838篇 |
综合类 | 8篇 |
一般理论 | 6篇 |
预防医学 | 285篇 |
眼科学 | 38篇 |
药学 | 312篇 |
中国医学 | 2篇 |
肿瘤学 | 339篇 |
出版年
2023年 | 50篇 |
2022年 | 90篇 |
2021年 | 225篇 |
2020年 | 103篇 |
2019年 | 167篇 |
2018年 | 202篇 |
2017年 | 135篇 |
2016年 | 146篇 |
2015年 | 161篇 |
2014年 | 232篇 |
2013年 | 294篇 |
2012年 | 435篇 |
2011年 | 431篇 |
2010年 | 217篇 |
2009年 | 197篇 |
2008年 | 293篇 |
2007年 | 290篇 |
2006年 | 235篇 |
2005年 | 220篇 |
2004年 | 157篇 |
2003年 | 168篇 |
2002年 | 123篇 |
2001年 | 73篇 |
2000年 | 64篇 |
1999年 | 58篇 |
1998年 | 28篇 |
1997年 | 17篇 |
1996年 | 19篇 |
1995年 | 26篇 |
1994年 | 14篇 |
1993年 | 17篇 |
1992年 | 52篇 |
1991年 | 40篇 |
1990年 | 54篇 |
1989年 | 43篇 |
1988年 | 37篇 |
1987年 | 34篇 |
1986年 | 31篇 |
1985年 | 34篇 |
1984年 | 21篇 |
1983年 | 22篇 |
1980年 | 13篇 |
1979年 | 19篇 |
1978年 | 14篇 |
1977年 | 12篇 |
1976年 | 10篇 |
1975年 | 10篇 |
1974年 | 12篇 |
1968年 | 11篇 |
1967年 | 12篇 |
排序方式: 共有5443条查询结果,搜索用时 15 毫秒
21.
Gastrointestinal colonization and systemic dissemination by Candida albicans and Candida tropicalis in intact and immunocompromised mice.
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Gastrointestinal colonization and systemic dissemination by Candida albicans and Candida tropicalis were compared in intact and immunocompromised mice. Five-day-old CFW mice were inoculated by the oral-intragastric route with 1.0 x 10(7) CFU of two C. albicans and two C. tropicalis strains isolated from the blood of patients with acute leukemia and with C. albicans 4918 and its cerulenin-resistant mutant 4918-10. C. albicans and C. tropicalis spread to the lungs, liver, and kidneys within 30 min postinoculation, and organ CFU of the two species were comparable over the following 10 days. Close association of blastoconidia with the villous surface of the small intestine resulted in lysis of microvilli and then progressive invasion of villi. Blastoconidia within villi were surrounded by a conspicuous zone of clearing. Persistent colonization of the small and large intestines by C. albicans blood isolates and strains 4918 and 4918-10 was similar for 31 days after inoculation, but consistently exceeded that of C. tropicalis. In mice colonized with C. albicans, immunosuppression with cortisone acetate and cyclophosphamide on days 30 and 33 after inoculation increased stomach CFU 40- to 370-fold and intestinal CFU 30- to 80-fold. In contrast, persistent colonization by C. tropicalis was undetectable before immunosuppression and only became apparent after treatment. C. albicans disseminated more frequently and with higher organ CFU than C. tropicalis. Despite this fact, 20% of mice infected with C. tropicalis died, compared with 4% infected with C. albicans blood isolates. Indirect immunofluorescence revealed penetrative growth by Candida hyphae exclusively in the mucosa and submucosa of the stomach from immunosuppressed, persistently colonized mice. Taken together, the data indicate that C. tropicalis appears to be more virulent than C. albicans and that factors responsible for gastrointestinal colonization, systemic dissemination, and mortality in immunocompromised mice may not be identical. 相似文献
22.
Anti-HBs Cellular Immune Response in Kidney Recipients before and 4 Months after Transplantation
下载免费PDF全文
![点击此处可从《Clinical and Vaccine Immunology : CVI》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Patricia Aguilar Edith Renoult Loraine Jarrosson Marie Nathalie Kolopp-Sarda Christine Prin Mathieu Gilbert C. Faure Mich
le Kessler Marie C. Bene Chantal Kohler Anne Kennel De March 《Clinical and Vaccine Immunology : CVI》2003,10(6):1117-1122
Patients with renal failure represent a population at risk for hepatitis B, since only 50 to 60% of them develop protective humoral responses after vaccination. As this could be due to an altered regulation of cellular immune responses, the objectives of the present study were to evaluate the proliferative abilities of lymphocytes from patients with chronic renal failure after stimulation in vitro with a mitogen (pokeweed mitogen [PWM]) or HBsAg. In order to differentiate between the immunodeficiency associated with renal failure and that due to immunosuppression posttransplantation, the same subjects were tested before and 4 months after kidney transplantation. The lymphoproliferation assay used was performed by flow cytometry, which is based on sequential analysis of the cell cycle and which allows analysis of cytokine production. Serologically, the group of 36 patients tested comprised 22% nonresponders, 30% poor responders, and 48% responders. Lymphocyte growth was observed for all patients after stimulation with PWM, indicating that these cells had the capacity to proliferate in vitro. The level of lymphoproliferation in response to PWM was significantly reduced after transplantation, yet both before and after transplantation, all serologic nonresponders developed cellular responses to at least two vaccines. No correlation between humoral and cellular responses was shown. Proliferating cells were lymphocytes, which mostly secreted interleukin 4 (IL-4) and IL-10 for the three serologic groups. This study suggests that even when repeated vaccination fails to induce significant antibody levels in patients with renal failure, specific HBs cellular responses develop, and these may prove to be efficient in protecting these patients against hepatitis B. 相似文献
23.
24.
25.
S Gerber D Larget-Piet J M Rozet D Bonneau M Mathieu V Der Kaloustian A Munnich J Kaplan 《Journal of medical genetics》1996,33(1):77-79
Usher syndrome type I (US1) is an autosomal recessive condition in which three different genes have been already localised (USH1A, USH1B, and USH1C on chromosomes 14q32, 11q13, and 11p15 respectively). The genetic heterogeneity of US1 has been confirmed in a previous study by linkage analysis of 20 French pedigrees. Here, we report the genetic exclusion of the three previously reported loci in two large multiplex families of Moroccan and Pakistani origin, suggesting the existence of at least a fourth locus in Usher syndrome type I. 相似文献
26.
27.
Cytosine methylation was studied at the level of the euchromatin/heterochromatin transition genomic region of the Arabidopsis chromosome 5 left arm. It has been shown using a monoclonal antibody against 5-methylcytosines that the density of DNA methylation
increases from the euchromatin towards the heterochromatin. YACs mapped along this region were characterized for their repeated
sequences content. Some of them, corresponding to euchromatin, euchromatin/heterochromatin border and heterochromatin regions,
were used as probes for a Southern blot analysis of methylation. This revealed that the degree of mCmCGG and GATmC methylation
increases significantly from the euchromatin towards the heterochromatin. Moreover, an analysis of cytosine methylation levels
(% of 5-methylcytosine) of different DNA fragments, inside the same genomic region, was performed using PCR and/or Southern
blot approaches. There is a gradual increase of methylation along the genomic region analyzed: CpG methylation in the euchromatic
fraction, CpG and CpNpG methylation at the euchromatin/heterochromatin transition and an additional asymmetrical methylation
in the repeated-heterochromatic fraction. The most methylated repeated family at CpG, CpNpG and asymmetrical sites is the
5S ribosomal DNA, highly methylated even though it is transcribed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
28.
Cell domain-dependent changes in the glutamatergic and GABAergic drives during epileptogenesis in the rat CA1 region 总被引:2,自引:0,他引:2
Lynda El-Hassar Mathieu Milh Fabrice Wendling Nadine Ferrand Monique Esclapez Christophe Bernard 《The Journal of physiology》2007,578(1):193-211
An increased ratio of the glutamatergic drive to the overall glutamatergic/GABAergic drive characterizes the chronic stage of temporal lobe epilepsy (TLE), but it is unclear whether this modification is present during the latent period that often precedes the epileptic stage. Using the pilocarpine model of TLE in rats, we report that this ratio is decreased in hippocampal CA1 pyramidal cells during the early phase of the latent period (3–5 days post pilocarpine). It is, however, increased during the late phase of the latent period (7–10 days post pilocarpine), via cell domain-dependent alterations in synaptic current properties, concomitant with the occurrence of interictal-like activity in vivo . During the late latent period, the glutamatergic drive was increased in somata via an enhancement in EPSC decay time constant and in dendrites via an increase in EPSC frequency and amplitude. The GABAergic drive remained unchanged in the soma but was decreased in dendrites, since the drop off in IPSC frequency was more marked than the increase in IPSC kinetics. Theoretical considerations suggest that these modifications are sufficient to produce interictal-like activity. In epileptic animals, the ratio of the glutamatergic drive to the overall synaptic drive was not further modified, despite additional changes in synaptic current frequency and kinetics. These results show that the global changes to more glutamatergic and less GABAergic activities in the CA1 region precede the chronic stage of epilepsy, possibly facilitating the occurrence and/or the propagation of interictal activity. 相似文献
29.
Goullé JP Lhermitte M Bartholi M Boyer JC Capolaghi B Charlier C Danel V Desch G Feuillu A Flouvat B Mathieu D Nisse P Sadeg N Szymanowicz A;Groupe de travail pluridisciplinaire SFBC-SFTA-STC < Toxicologie et biologie clinique > 《Annales de biologie clinique》2003,61(4):421-433
The members of the joint group "Toxicology and Clinical Biology" of the French Society of Clinical Biology (SFBC), the French Society of Analytical Toxicology (SFTA), and the Society of Clinical Toxicology (STC), suggest guidelines to meet the requirements of clinical biologists who are not specialized in toxicology. Based on good laboratory practice they propose a number of guidelines. Three synthetic tables have been established. They are not only toxicity biomarkers and metabolic disorders associated with the main severe intoxications, but also clinical signs that are observed during these intoxications, finally biological sampling as a precautionary measure. The table also takes into account approximately fifty xenobiotics: main clinical signs emergency, identification or quantification of the suspected product, useful biological markers, therapeutic, quantitations necessary to take into consideration patient care, and poison antidotes, are described. Recommendations regarding medical and forensic techniques are also proposed by the group. It is also necessary to collect and store biological samples when the individual patients are in charge. These samples will be analyzed or not depending on the individual case history. 相似文献
30.
Decallonne B van Etten E Overbergh L Valckx D Bouillon R Mathieu C 《Journal of autoimmunity》2005,24(4):281-289
AIMS/HYPOTHESIS: Resistance of NOD thymocytes to apoptosis-inducing signals is restored by 1alpha,25-dihydroxyvitamin D3 (1alpha,25OH2D3), a therapy preventing diabetes in NOD mice. We studied whether modulation of thymocyte apoptosis is due to direct effects on thymic T lymphocytes or indirect effects via thymic dendritic cells, since both cell types constitute known targets for 1alpha,25OH2D3. METHODS AND RESULTS: Female NOD mice were treated with 1alpha,25OH2D3 (5microg/kg/2d) from 21 to 70 days. Vehicle-treated NOD and NOR mice served as controls. Analysis of thymic T lymphocytes from 1alpha,25OH2D3)-treated mice revealed a decrease in number of apoptosis-resistant CD4+CD8+ and CD4+CD8-HSA(high) T lymphocyte subsets, higher pro-apoptotic IL-2 and FasL, and lower anti-apoptotic Bclx-L mRNA expression levels. Thymic dendritic cells from 1alpha,25OH2D3-treated NOD mice had increased CD8alpha+FasL+ and CD80+/86+ expression compared to control NOD mice. In a syngeneic co-culture system of thymocytes and thymic dendritic cells, apoptosis levels were 20% higher only in co-cultures where both T cell- and dendritic cell-compartments originated from 1alpha,25OH2D3-treated mice. Activation-induced cell death-sensitivity in peripheral T lymphocytes was comparable to levels present in NOR mice, confirming better thymic selection in 1alpha,25OH2D3-treated mice. CONCLUSION/INTERPRETATION: We conclude that 1alpha,25OH2D3 needs both thymic T cell- and dendritic cell-compartments to exert its apoptosis-restorative effects in NOD thymocytes. 相似文献