全文获取类型
收费全文 | 31103篇 |
免费 | 2062篇 |
国内免费 | 196篇 |
专业分类
耳鼻咽喉 | 423篇 |
儿科学 | 583篇 |
妇产科学 | 577篇 |
基础医学 | 4133篇 |
口腔科学 | 799篇 |
临床医学 | 2662篇 |
内科学 | 6646篇 |
皮肤病学 | 776篇 |
神经病学 | 2152篇 |
特种医学 | 2112篇 |
外科学 | 4470篇 |
综合类 | 846篇 |
现状与发展 | 1篇 |
一般理论 | 15篇 |
预防医学 | 1625篇 |
眼科学 | 865篇 |
药学 | 2129篇 |
1篇 | |
中国医学 | 178篇 |
肿瘤学 | 2368篇 |
出版年
2023年 | 309篇 |
2022年 | 663篇 |
2021年 | 1140篇 |
2020年 | 672篇 |
2019年 | 825篇 |
2018年 | 1047篇 |
2017年 | 716篇 |
2016年 | 906篇 |
2015年 | 1151篇 |
2014年 | 1394篇 |
2013年 | 1494篇 |
2012年 | 2350篇 |
2011年 | 2266篇 |
2010年 | 1351篇 |
2009年 | 1175篇 |
2008年 | 1689篇 |
2007年 | 1676篇 |
2006年 | 1645篇 |
2005年 | 1588篇 |
2004年 | 1260篇 |
2003年 | 1048篇 |
2002年 | 918篇 |
2001年 | 644篇 |
2000年 | 622篇 |
1999年 | 518篇 |
1998年 | 223篇 |
1997年 | 204篇 |
1996年 | 143篇 |
1995年 | 139篇 |
1994年 | 143篇 |
1993年 | 112篇 |
1992年 | 210篇 |
1991年 | 231篇 |
1990年 | 211篇 |
1989年 | 177篇 |
1988年 | 162篇 |
1987年 | 192篇 |
1986年 | 145篇 |
1985年 | 142篇 |
1984年 | 115篇 |
1983年 | 97篇 |
1982年 | 64篇 |
1981年 | 61篇 |
1980年 | 58篇 |
1979年 | 89篇 |
1978年 | 60篇 |
1977年 | 66篇 |
1975年 | 62篇 |
1974年 | 69篇 |
1971年 | 55篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
Lim DJ Rubenstein AE Evans DG Jacks T Seizinger BG Baser ME Beebe D Brackmann DE Chiocca EA Fehon RG Giovannini M Glazer R Gusella JF Gutmann DH Korf B Lieberman F Martuza R McClatchey AI Parry DM Pulst SM Ramesh V Ramsey WJ Ratner N Rutkowski JL Ruttledge M Weinstein DE 《Journal of neurogenetics》2000,14(2):63-106
152.
153.
Recurrent self-limited fungemia caused by Yarrowia lipolytica in a patient with acute myelogenous leukemia
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Yarrowia lipolytica is a weakly pathogenic yeast that is rarely isolated from the blood. We observed transient recurrent catheter-related fungemia attributable to this organism in a leukemic patient. The fungemia and accompanying fever subsided spontaneously. The data suggest that it might be possible to withhold specific treatment for Y. lipolytica fungemia even in an immunocompromised patient. 相似文献
154.
Thomas Hoffman Anil K. Tripathi Young Lim Lee Elaine F. Lizzio Ezio Bonvini 《Inflammation》1992,16(6):571-585
Human monocytes released superoxide anion, prostaglandin E2, leukotriene B4, IL-1, and TNF when exposed to plastic surfaces coated with murine anti-CD3 monoclonal antibody, OKT 3. Stimulation of mediator release by OKT 3 was dependent on the amount of antibody immobilized onto wells of plastic tissue culture plates. Soluble antibody or antibody adsorbed to monocytes and reacted with an aggregating (cross-linking) second antibody failed to induce mediator release. Monocytes armed with OKT 3 formed rosettes with T cells in a fashion indistinguishable from that seen between monocytes and T cells sensitized with OKT 3. Monocytes with adsorbed OKT 3 antibodies released IL-1 and TNF- when exposed to unsensitized T cells, although increased superoxide release could not be detected. OKT 4a, a murine IgG2a antibody that reacts with a different T cell epitope (CD4), failed to induce cytokine release from monocytes when cross-linked by T cells or a CD4+ T cell line, even in the presence of IL-2 or IFN-. These data indicate that certain antibodies bound to Fc receptors (FcR) of monocytes may trigger monocyte function when reacting with cells bearing the appropriate target antigens. FcR-mediated signaling resulting in mediator release may be involved in initiating or regulating the immune response. Furthermore, systemically administered monoclonal antibodies may induce inflammatory responses and their attendant symptomatologies via their interaction with FcR-bearing inflammatory cells. 相似文献
155.
Syndrome of partial aniridia, cerebellar ataxia, and mental retardation--Gillespie syndrome 总被引:2,自引:0,他引:2
Here we describe a 5-year-old girl with Gillespie syndrome of cerebellar ataxia, partial aniridia, and mental retardation. The Gillespie syndrome probably is an autosomal recessive trait. 相似文献
156.
Amanita virosa induced toxic hepatitis: report of three cases 总被引:1,自引:0,他引:1
We report here three cases of Amanita virosa induced toxic hepatitis. Two of the three cases recovered but the other died 10 days after mushroom ingestion. Since the mortality of Amanita mushroom induced toxic hepatitis is very high, prompt diagnosis and aggressive therapeutic measures should be initiated as soon as possible. Our cases showed that the initial serum aminotransferase levels might not predict the clinical outcome of the patient, but that the prothrombin time (PT) seemed to be a more useful prognostic marker. Close monitoring of aminotransferase levels and PT as well as appropriate therapy are recommended. All three cases showed signs of proteinuria and we were able to characterize mixed tubular and glomerular type proteinuria at 3 or 4 days after ingestion in two cases. Among the previously reported Korean cases of suspected Amanita induced toxic hepatitis, most species could not be identified except for four cases of Amanita virosa. No cases of Amanita phalloides induced toxic hepatitis have been identified in Korea so far. 相似文献
157.
Perturbation and proinflammatory type activation of V delta 1(+) gamma delta T cells in African children with Plasmodium falciparum malaria
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)
Hviid L Kurtzhals JA Adabayeri V Loizon S Kemp K Goka BQ Lim A Mercereau-Puijalon O Akanmori BD Behr C 《Infection and immunity》2001,69(5):3190-3196
gamma delta T cells have variously been implicated in the protection against, and the pathogenesis of, malaria, but few studies have examined the gamma delta T-cell response to malaria in African children, who suffer the large majority of malaria-associated morbidity and mortality. This is unfortunate, since available data suggest that simple extrapolation of conclusions drawn from studies of nonimmune adults ex vivo and in vitro is not always possible. Here we show that both the frequencies and the absolute numbers of gamma delta T cells are transiently increased following treatment of Plasmodium falciparum malaria in Ghanaian children and they can constitute 30 to 50% of all T cells shortly after initiation of antimalarial chemotherapy. The bulk of the gamma delta T cells involved in this perturbation expressed V delta 1 and had a highly activated phenotype. Analysis of the T-cell receptors (TCR) of the V delta 1(+) cell population at the peak of their increase showed that all expressed V gamma chains were used, and CDR3 length polymorphism indicated that the expanded V delta 1 population was highly polyclonal. A very high proportion of the V delta 1(+) T cells produced gamma interferon, while fewer V delta 1(+) cells than the average proportion of all CD3(+) cells produced tumor necrosis factor alpha. No interleukin 10 production was detected among TCR-gamma delta(+) cells in general or V delta 1(+) cells in particular. Taken together, our data point to an immunoregulatory role of the expanded V delta 1(+) T-cell population in this group of semi-immune P. falciparum malaria patients. 相似文献
158.
Reduction of morbidity and mortality rates for neonatal group B streptococcal disease through early diagnosis and chemoprophylaxis. 总被引:9,自引:7,他引:9
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Pregnant women, part of the term service population at Orlando Regional Medical Center, were screened for group B streptococci (GBS), using Lim Group B Strep Broth (GIBCO Laboratories, Madison, Wis.) and the Phadebact Strep B Test (Pharmacia Diagnostics, Piscataway, N.J.). Of the 803 women screened, 173 were confirmed as colonized with GBS at the time of admission in labor. Eighty of these women were treated with ampicillin at least 6 h prior to delivery. The remaining 93 women received no ampicillin. None of the infants born to the treated women was colonized with GBS at surface culture sites. Forty-three of the infants born to untreated women were colonized. Rapid identification of GBS colonization in women, combined with ampicillin chemoprophylaxis, significantly reduced vertical transmission of GBS. 相似文献
159.
alpha(v)beta(3) Integrin in central nervous system tumors 总被引:1,自引:0,他引:1
Lim M Guccione S Haddix T Sims L Cheshier S Chu P Vogel H Harsh G 《Human pathology》2005,36(6):665-669
alpha(v)beta(3) Is an integrin specifically expressed in endothelial cells of newly forming blood vessels. Integrin-mediated angiogenesis is hypothesized to play a central role in the development and the progression of central nervous system neoplasms. Accordingly, it is considered a potential target for antiangiogenic therapy. In the current study, we compare the expression of alpha(v)beta(3) in ependymomas, oligodendrogliomas, pilocytic astrocytomas, medulloblastomas, and vestibular schwannomas (acoustic neuromas). Samples of 5 tumors of each of the 5 tumor types were harvested surgically and frozen. After the pathological diagnosis was confirmed, immunohistochemistry was performed using an anti- alpha(v)beta(3) monoclonal antibody (LM609). The expression of alpha(v)beta(3) was assessed using a 4-tiered (0-3) grading scheme reflecting the percentage of positively staining vessels. All vestibular schwannomas demonstrated strong (grade 3) alpha(v)beta(3) expression. The expression was uniformly prominent in Antoni B regions of the tumors. Of 5 ependymomas, 4 demonstrated uniformly strong alpha(v)beta(3). Oligodendrogliomas, medulloblastomas, and pilocytic astrocytomas demonstrated more variable alpha(v)beta(3). alpha(v)beta(3) may contribute significantly to angiogenesis in vestibular schwannomas and ependymomas. Despite the high vascular density of oligodendrogliomas, pilocytic astrocytomas, and medulloblastomas, these tumors had variable moderate alpha(v)beta(3) expression. This discrepancy suggests temporal and/or regional variability in the angiogenesis in these types of tumor. This study provides the first demonstration of alpha(v)beta(3) expression in vestibular schwannomas, medulloblastomas, and pilocytic astrocytomas. 相似文献
160.
Comparison of nasopharyngeal flocked swabs and aspirates for rapid diagnosis of respiratory viruses in children. 总被引:3,自引:0,他引:3
BACKGROUND: The quality of clinical specimens is a crucial determinant for virological diagnosis. OBJECTIVES: We compared the viral diagnostic yield for influenza A and respiratory syncytial virus (RSV) from the recently developed nasopharyngeal flocked swabs (NPFS) with nasopharyngeal aspirates (NPA) collected in parallel from 196 hospitalized children with acute respiratory infection during the peak period of influenza A and RSV activity in Hong Kong. Specimens were tested by RT-PCR for influenza A and RSV and viral load determined. They were also tested by direct immunofluorescence (DIF) for influenza A and B, RSV, parainfluenza types 1-3 and adenovirus. RESULTS: Both NPA and NPFS had excellent sensitivity (100%) for detecting influenza A by RT-PCR but NPA was slightly more sensitive than NPFS for detecting RSV by both RT-PCR (100% vs. 92.3%) and DIF (87.2% vs. 84.6%) and for detecting influenza A by DIF (90.2% vs. 82.9%). Viral load for influenza A in NPA and NPFS was not significantly different but that for RSV was higher in NPA. CONCLUSION: NPA remains the optimal specimen for diagnosis of respiratory infections by RT-PCR and DIF. However, collection of NPFS is easier to perform in an out-patient setting, was more acceptable to parents and less likely to generate aerosols than NPA engendering potentially less infection control hazard. 相似文献