全文获取类型
收费全文 | 225210篇 |
免费 | 4675篇 |
国内免费 | 260篇 |
专业分类
耳鼻咽喉 | 1632篇 |
儿科学 | 8461篇 |
妇产科学 | 4335篇 |
基础医学 | 24128篇 |
口腔科学 | 2306篇 |
临床医学 | 17207篇 |
内科学 | 42088篇 |
皮肤病学 | 1816篇 |
神经病学 | 21957篇 |
特种医学 | 9899篇 |
外科学 | 32797篇 |
综合类 | 2600篇 |
现状与发展 | 1篇 |
一般理论 | 43篇 |
预防医学 | 22659篇 |
眼科学 | 3571篇 |
药学 | 13310篇 |
中国医学 | 759篇 |
肿瘤学 | 20576篇 |
出版年
2024年 | 67篇 |
2023年 | 618篇 |
2022年 | 1144篇 |
2021年 | 2428篇 |
2020年 | 1399篇 |
2019年 | 1797篇 |
2018年 | 23542篇 |
2017年 | 18644篇 |
2016年 | 20995篇 |
2015年 | 2751篇 |
2014年 | 3221篇 |
2013年 | 3804篇 |
2012年 | 11328篇 |
2011年 | 25244篇 |
2010年 | 20983篇 |
2009年 | 13396篇 |
2008年 | 22674篇 |
2007年 | 24828篇 |
2006年 | 3545篇 |
2005年 | 4884篇 |
2004年 | 5889篇 |
2003年 | 6574篇 |
2002年 | 4506篇 |
2001年 | 490篇 |
2000年 | 575篇 |
1999年 | 398篇 |
1998年 | 525篇 |
1997年 | 480篇 |
1996年 | 276篇 |
1995年 | 279篇 |
1994年 | 274篇 |
1993年 | 197篇 |
1992年 | 131篇 |
1991年 | 164篇 |
1990年 | 183篇 |
1989年 | 149篇 |
1988年 | 124篇 |
1987年 | 101篇 |
1986年 | 79篇 |
1985年 | 88篇 |
1984年 | 101篇 |
1983年 | 87篇 |
1982年 | 102篇 |
1981年 | 66篇 |
1980年 | 100篇 |
1978年 | 41篇 |
1938年 | 63篇 |
1934年 | 43篇 |
1932年 | 60篇 |
1930年 | 54篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
To examine the role that lipopolysaccharide (LPS)-like molecules from the filarial intracellular endobacteria Wolbachia might play in the development of filarial infections, a natural infection in the LPS-nonresponsive C3H/HeJ mouse strain was compared to that of the LPS-responsive C3H/HeN mouse strain. C3H/HeN mice have been shown to be susceptible to the rodent filarial nematode Litomosoides sigmodontis, with the development of adult worms including females containing mature microfilariae (first stage larvae) in the uterine tubes. However, free microfilariae are not detected. In this study the worm burden and worm length were not significantly different between the C3H/HeN and C3H/HeJ mice. However, the fertility of worms from CeH/HeJ mice was found to be higher than those from C3H/HeN mice. Significantly, mature microfilariae were found at the site of infection only in C3H/HeJ mice. These results indicate a role for TLR4 signaling in the immune response that inhibits worm embryogenesis and prevents the release of microfilariae or directly kills released microfilariae. 相似文献
952.
Background
Statistics is relevant to students and practitioners in medicine and health sciences and is increasingly taught as part of the medical curriculum. However, it is common for students to dislike and under-perform in statistics. We sought to address these issues by redesigning the way that statistics is taught. 相似文献953.
Yago Nieto Nigel Patton Timothy Hawkins Ruth Spearing Scott I Bearman Roy B Jones Elizabeth J Shpall Rachel Rabinovitch Chan Zeng Anna Barón Peter A McSweeney 《Biology of blood and marrow transplantation》2006,12(2):217-225
We evaluated tacrolimus/mycophenolate mofetil (MMF) for graft-versus-host disease (GVHD) prophylaxis after a nonmyeloablative stem cell transplantation (NST) from a matched sibling donor (MSD). Thirty-two patients (median age, 57 years) with advanced hematologic malignancies, who were poor candidates for a conventional myeloablative transplantation, received fludarabine (30 mg/m(2), day -4 to day -2), total-body irradiation (TBI) (200 cGy, day 0), infusion of donor peripheral blood progenitor cells (day 0), oral tacrolimus 0.06 mg/kg twice daily (from day 3), and oral MMF at 15 mg/kg twice daily (days 0-+27). Tacrolimus was tapered from day +100 to day +180 in those patients with indolent malignancies (n = 25), and from day +35 to day +56 in those with aggressive tumors (n = 7). Regimen toxicities and myelosuppression were mild, allowing 75% of patients to have entirely outpatient transplantations. One patient (3%) experienced a nonfatal graft rejection. Rates of grades II-IV and III-IV acute GVHD were 15.6% and 3%, respectively. Acute GVHD was diagnosed at median day +78 (range, days +31-+84). Extensive chronic GVHD was observed in 10 of 24 evaluable patients (41.6%) at a median onset of day +198 (range, days +128-+277), either spontaneously (n = 5) or elicited after tumor progression (n = 5). Five patients experienced transplantation-related mortality (TRM) (15.6%) from either acute GVHD-related multiorgan failure (MOF) (n = 3) or infectious complications (n = 2). At median follow-up of 19 months (range, 2-41 months), the overall survival, progression-free survival, and disease-free survival rates are 62.5%, 50%, and 40%, respectively. In conclusion, the use of tacrolimus/MMF after MSD NST is associated with encouraging rates of GVHD control. 相似文献
954.
Lehmann A Katayama S Harrison C Dhut S Kitamura K McDonald N Toda T 《Genes to cells : devoted to molecular & cellular mechanisms》2004,9(5):367-382
Skp1 is a central component of the E3 ubiquitin ligase SCF (Skp1-Cullin-1-F-box). It forms an adapter bridge between Cullin-1 and the substrate-determining component, the F-box protein. In order to establish the role of Skp1, a temperature sensitive (ts) screen was carried out using mutagenic PCR (polymerase chain reaction) and 9 independent ts mutants were isolated. Mapping the mutated residues on the 3-D structure of human Skp1 suggested that the mutants would be compromised in binding to F-box proteins but not Cullin-1 (Pcu1). In order to assess the binding properties of ts Skp1, 12 F-box proteins and Pcu1 were epitope-tagged, and co-immunoprecipitation performed. This systematic analysis showed that ts Skp1 retains binding to Pcu1. However, binding to three specific F-box proteins, essential Pof1, Pof3 involved in maintaining genome integrity, and nonessential Pof10, was reduced. skp1ts cells exhibit a G2 cell cycle delay, which is attributable to activation of the DNA damage checkpoint. Intriguingly, contrary to pof3 mutants, in which this checkpoint is required for survival, checkpoint abrogation in skp1(ts) suppresses a G2 delay and furthermore almost rescues the ts phenotype. The activation mechanism of the DNA damage checkpoint therefore differs between pof3Delta and skp1(ts), implicating a novel role for Skp1 in the checkpoint-signalling cascade. 相似文献
955.
956.
Philippe A. Puech Loïc Boussel Samir Belfkih Laurent Lemaitre Philippe Douek Régis Beuscart 《Journal of digital imaging》2007,20(2):122-130
DicomWorks is freeware software for reading and working on medical images [digital imaging and communication in medicine (DICOM)].
It was jointly developed by two research laboratories, with the feedback of more than 35,000 registered users throughout the
world who provided information to guide its development. We detail their occupations (50% radiologists, 20% engineers, 9%
medical physicists, 7% cardiologists, 6% neurologists, and 8% others), geographic origins, and main interests in the software.
The viewer’s interface is similar to that of a picture archiving and communication system viewing station. It provides basic
but efficient tools for opening DICOM images and reviewing and exporting them to teaching files or digital presentations.
E-mail, FTP, or DICOM protocols are supported for transmitting images through a local network or the Internet. Thanks to its
wide compatibility, a localized (15 languages) and user-friendly interface, and its opened architecture, DicomWorks helps
quick development of non proprietary, low-cost image review or teleradiology solutions in developed and emerging countries. 相似文献
957.
Bettina H Clausen Kate L Lambertsen Alicia A Babcock Thomas H Holm Frederik Dagnaes-Hansen Bente Finsen 《Journal of neuroinflammation》2008,5(1):46
Background
Interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) are expressed by microglia and infiltrating macrophages following ischemic stroke. Whereas IL-1β is primarily neurotoxic in ischemic stroke, TNF-α may have neurotoxic and/or neuroprotective effects. We investigated whether IL-1β and TNF-α are synthesized by overlapping or segregated populations of cells after ischemic stroke in mice. 相似文献958.
Plasmids containing the inosine monophosphate dehydrogenase gene CaIMH3 from Candida albicans strain ATCC 32354 transform their host to resistance against mycophenolic acid (MPA). The transformants maintain the plasmids at a high copy number (20–40 per cell) and express the CaIMH3 gene at very high levels relative to untransformed controls. The plasmid copy number can be controlled by the concentration of MPA in the media. The transformation procedure is reproducible and the efficiency of transformation is high, up to 15,000 per microgram. Unrearranged plasmids are readily recovered by transforming total DNA from transformants back into Escherichia coli. C. albicans genes cloned into the plasmid are expressed at elevated levels relative to untransformed controls. A derivative vector containing the CaMAL2 promoter and termination sequences expresses the CaERG11 ORF at high levels and confers moderate resistance to fluconazole. These shuttle vectors should facilitate global genomics approaches in C. albicans that have been hampered by its diploid genome. 相似文献
959.
Millar M 《Journal of behavioral medicine》2005,28(5):425-432
This study examined the impact of perceived stress on responses to messages that encouraged the performance of health promotion
and disease detection behaviors. It was hypothesized that increases in perceived stress would be associated with decreased
processing of messages encouraging disease detection behaviors, and that increases in perceived stress would not effect the
processing of messages encouraging health promotion behaviors. To test these hypotheses participants completed a perceived
stress measure and then read a message that encouraged the performance of either a health promotion or a disease detection
behavior. Then the participants were asked to indicate their agreement with the message and to attempt to recall the message.
The results indicated that participants experiencing higher levels of perceived stress spent less time reading and recalled
less of the messages about detection behaviors than of the messages about promotion behaviors. When participants were experiencing
lower levels of perceived stress these differences disappeared.
相似文献
相似文献
960.
Józef Dulak Agnieszka Loboda Agnieszka Jazwa Anna Zagorska Jacob D?rler Hannes Alber Wolfgang Dichtl Franz Weidinger Matthias Frick Alicja Jozkowicz 《Endothelium》2005,12(5-6):233-241
The pleiotropic effects of statins, inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, have been recently extended to the modulation of angiogenesis. Here, to get more insight into the statins action, the authors have investigated the effect of atorvastatin on the expression of several angiogenic and inflammatory genes in human umbilical endothelial cells (HUVECs). Atorvastatin was proangiogenic at the dose of 10 nM, and antiangiogenic at the concentrations of 1 to 10 micro M. Moreover, these higher concentrations inhibited also the proliferation of HUVECs induced by vascular endothelial growth factor (VEGF). Lower doses of atorvastatin did not influence endothelial cell proliferation. Importantly, atorvastatin at the micromolar concentrations diminished the production of interleukin (IL)-8, a proinflammatory and proangiogenic chemokine, and inhibited the synthesis of urokinase plasminogen activator (uPA), a potent proinflammatory mediator. However, it decreased also the expression of plasminogen activator inhibitor-1 (PAI-1) and thrombospondin-1 (TSP-1), the inhibitors of angiogenesis. Atorvastatin stimulated the expression of angiopoietin (Ang)-2 and moderately enhanced the expression of endothelial nitric oxide synthase (eNOS), whereas heme oxygenase-1 (HO-1) was not significantly affected. In conclusion, the present findings points to other angiogenesis-related effects of atorvastatin, which may be of relevance to the beneficial influence of statins in cardiovascular system. 相似文献