全文获取类型
收费全文 | 1829篇 |
免费 | 81篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 126篇 |
妇产科学 | 248篇 |
基础医学 | 221篇 |
口腔科学 | 30篇 |
临床医学 | 160篇 |
内科学 | 371篇 |
皮肤病学 | 19篇 |
神经病学 | 163篇 |
特种医学 | 49篇 |
外科学 | 189篇 |
综合类 | 7篇 |
预防医学 | 88篇 |
眼科学 | 41篇 |
药学 | 76篇 |
2篇 | |
肿瘤学 | 81篇 |
出版年
2024年 | 10篇 |
2023年 | 22篇 |
2022年 | 26篇 |
2021年 | 56篇 |
2020年 | 42篇 |
2019年 | 60篇 |
2018年 | 58篇 |
2017年 | 44篇 |
2016年 | 63篇 |
2015年 | 53篇 |
2014年 | 88篇 |
2013年 | 91篇 |
2012年 | 144篇 |
2011年 | 128篇 |
2010年 | 85篇 |
2009年 | 73篇 |
2008年 | 126篇 |
2007年 | 104篇 |
2006年 | 133篇 |
2005年 | 99篇 |
2004年 | 101篇 |
2003年 | 68篇 |
2002年 | 71篇 |
2001年 | 14篇 |
2000年 | 13篇 |
1999年 | 7篇 |
1998年 | 10篇 |
1997年 | 8篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 6篇 |
1993年 | 7篇 |
1992年 | 6篇 |
1991年 | 9篇 |
1990年 | 7篇 |
1989年 | 3篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 10篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 3篇 |
1972年 | 2篇 |
1967年 | 2篇 |
1960年 | 1篇 |
排序方式: 共有1912条查询结果,搜索用时 15 毫秒
21.
Valeria Feinshtein Zvi Ben-Zvi Eyal Sheiner Alaa Amash Boaz Sheizaf Gershon Holcberg 《Archives of gynecology and obstetrics》2010,281(3):387-392
Background
One of the most important hormones synthesized by the placenta during pregnancy is progesterone. The regulating mechanisms of progesterone synthesis and the mechanism responsible for the spontaneous onset of labor in women are still not fully understood. Progesterone is thought to have been involved in human parturition. The objective of this study was to compare the levels of progesterone in the human placentas, at the end of the gestation (37–41 weeks) in vaginal versus cesarean deliveries, and to evaluate the pattern of progesterone accumulation, instantly following its synthesis by the human placenta at the end of the pregnancy. 相似文献22.
Maya Margalit Eyal Attias Drorit Attias Deborah Elstein Ari Zimran Yaacov Matzner 《International journal of laboratory hematology》2001,23(4):243-247
The application of ozone is widely practised as a form of alternative medicine, particularly in Germany and Eastern Europe. Ozone major autohemotherapy (the return of a small amount of a patient’s blood to the circulation after ex vivo exposure to ozone) has been reported to have a therapeutic effect in various pathological conditions, including ischemic, infectious, autoimmune and neoplastic disorders. Ozone has an effect on the expression of cytokines, adhesion molecules and acute phase reactants, which are responsible in part for the respiratory inflammatory response observed after exposure to this gas. The purpose of the present study was to investigate the effect of ozone administration ex vivo, at a concentration commonly used in major autohemotherapy, on peripheral blood neutrophil function in vitro. Blood drawn from healthy volunteers was studied for neutrophil adhesion, chemotaxis and O?2 production before and after exposure to 30 μg/ml ozone. There was no significant difference in adhesion and chemotaxis of neutrophils exposed to ozone versus unexposed cells. O?2 production was minimally decreased (20.3 ± 5.0 vs. 22.1 ± 5.5 nmol/106 cells/10 min, respectively; P=0.01), a reduction of no clinical significance. This study confirms that major autohemotherapy with ozone is safe as far as neutrophil function is concerned. Combined with previous data, it seems that well‐designed clinical trials to assess the efficacy of major autohemotherapy would pose no danger to blood cell populations, and should be encouraged. 相似文献
23.
Zhang X Wang B O'Callaghan P Hjertström E Jia J Gong F Zcharia E Nilsson LN Lannfelt L Vlodavsky I Lindahl U Li JP 《Acta neuropathologica》2012,124(4):465-478
Neuroinflammation is typically observed in neurodegenerative diseases such as Alzheimer's disease, as well as after traumatic injury and pathogen infection. Resident immune cells, microglia and astrocytes, are activated and joined by blood-borne monocytes that traverse the blood-brain barrier and convert into activated macrophages. The activated cells express various cytokines, chemokines and proteolytic enzymes. To study the role of heparan sulfate proteoglycans in neuroinflammation, we employed a transgenic mouse overexpressing heparanase, an endoglucuronidase that specifically degrades heparan sulfate side chains. Neuroinflammation was induced by systemic challenge with lipopolysaccharide, or by localized cerebral microinjection of aggregated amyloid-β peptide, implicated in Alzheimer's disease. Lipopolysaccharide-treated control mice showed massive activation of resident microglia as well as recruitment of monocyte-derived macrophages into the brain parenchyma. Microinjection of aggregated amyloid-β elicited a similar inflammatory response, albeit restricted to the injection site, which led to dispersion and clearance of the amyloid. In the heparanase-overexpressing mice, all aspects of immune cell recruitment and activation were significantly attenuated in both inflammation models, as was amyloid dispersion. Accordingly, an in vitro blood-brain barrier model constructed from heparanase-overexpressing cerebral vascular cells showed impaired transmigration of monocytes compared to a corresponding assembly of control cells. Our data indicate that intact heparan sulfate chains are required at multiple sites to mediate neuroinflammatory responses, and further point to heparanase as a modulator of this process, with potential implications for Alzheimer's disease. 相似文献
24.
25.
Tsimerman G Roguin A Bachar A Melamed E Brenner B Aharon A 《Thrombosis and haemostasis》2011,106(2):310-321
Type 2 diabetes mellitus (T2DM) is associated with increased coagulability and vascular complications. Circulating microparticles (MPs) are involved in thrombosis, inflammation, and angiogenesis. However, the role of MPs in T2DM vascular complications is unclear. We characterised the cell origin and pro-coagulant profiles of MPs obtained from 41 healthy controls and 123 T2DM patients with coronary artery disease, retinopathy and foot ulcers. The effects of MPs on endothelial cell coagulability and tube formation were evaluated. Patients with severe diabetic foot ulcers expressed the highest levels of MPs originated from platelet and endothelial cells and negatively-charged phospholipid-bearing MPs. MP coagulability, calculated from MP tissue factor (TF) and TF pathway inhibitor (TFPI) ratio, was low in healthy controls and in diabetic retinopathy patients (<0.7) but high in patients with coronary artery disease and foot ulcers (>1.8, p≥0.002). MPs of all T2DM patients induced a more than two-fold increase in endothelial cell TF (antigen and gene expression) but did not affect TFPI levels. Tube networks were longest and most stable in endothelial cells that were incubated with MPs of healthy controls, whereas no tube formation occurred in MPs of diabetic patients with coronary artery disease. MPs of diabetic retinopathy and diabetic foot ulcer patients induced branched tube networks that were unstable and collapsed over time. This study demonstrates that MP characteristics are related to the specific type of vascular complications and may serve as a bio-marker for the pro- coagulant state and vascular pathology in patients with T2DM. 相似文献
26.
Barak Y Shamir E Zemishlani H Mirecki I Toren P Weizman R 《Progress in neuro-psychopharmacology & biological psychiatry》2002,26(6):1199-1202
OBJECTIVE: Most of the data supporting the use of atypical antipsychotics (AA) is based on studies in young adult patients. The present study is an open-label naturalistic follow-up study of olanzapine treatment vs. haloperidol for elderly chronic schizophrenia patients. MEHTOD: 20 patients (mean age 72.7+/-5.9 years, mean disease duration 33.1+/-12.0 years) who met the DSM-IV criteria for schizophrenia were randomly assigned to olanzapine (n=10) or haloperidol (n=10) treatment during acute exacerbation. Primary outcome measure was rating on the Clinical Global Impression (CGI) scale and the Positive and Negative Symptom Scale (PANSS). RESULTS: Between-group differences were computed using analysis of covariance. PANSS Total score decreased from 84 at baseline to 65 after treatment with olanzapine while decreased only from 79 to 74 with haloperidol treatment (F= 6.66, P=.02). PANSS Negative subscale decreased from 19 at baseline to 15 with olanzapine treatment while increased (deteriorated) from 18 to 20 with haloperidol treatment (F=23.37, P=.0003). CGI decreased from baseline with both olanzapine and haloperidol treatments (1.1 vs. 0.4) but the decrease in the olanzapine group was significantly greater (F=4.63, P=.05). Mean weight increased in both groups but without statistical difference between groups. CONCLUSIONS: In elderly chronic schizophrenia patients, olanzapine treatment is superior to haloperidol in reducing negative symptoms as well as less induction of extrapyramidal symptoms (EPS). 相似文献
27.
28.
Eyal Reinstein Katia Orvin Einav Tayeb‐Fligelman Hadas Stiebel‐Kalish Shay Tzur Allen L. Pimienta Lily Bazak Tuvia Bengal Lior Cohen Dan D. Gaton Concetta Bormans Meytal Landau Ran Kornowski Mordechai Shohat Doron M. Behar 《Human mutation》2015,36(4):439-442
We describe a Bedouin family with a novel autosomal recessive syndrome characterized by dilated cardiomyopathy and septo‐optic dysplasia. Genetic analysis revealed a homozygous missense mutation in TAX1BP3, which encodes a small PDZ domain containing protein implicated in regulation of the Wnt/β‐catenin signaling pathway, as the causative mutation. The mutation affects a conserved residue located at the core of TAX1BP3 binding pocket and is predicted to impair the nature of a crucial hydrophobic patch, thereby interrupting the structure and stability of the protein, and its ability to interact with other proteins. TAX1BP3 is highly expressed in heart and brain and consistent with the clinical findings observed in our patients; a knockdown of TAX1BP3 causes elongation defects, enlarged pericard, and enlarged head structures in zebrafish embryos. Thus, we describe a new genetic disorder that expands the monogenic cardiomyopathy disease spectrum and suggests that TAX1BP3 is essential for heart and brain development. 相似文献
29.
Anat Klein Hila Schwartz Orit Sagi‐Assif Tsipi Meshel Sivan Izraely Shlomit Ben Menachem Roman Bengaiev Amir Ben‐Shmuel Clara Nahmias Pierre‐Olivier Couraud Isaac P Witz Neta Erez 《The Journal of pathology》2015,236(1):116-127
Melanoma is the leading cause of skin cancer mortality. The major cause of melanoma mortality is metastasis to distant organs, frequently to the brain. The microenvironment plays a critical role in tumourigenesis and metastasis. In order to treat or prevent metastasis, the interactions of disseminated tumour cells with the microenvironment at the metastatic organ have to be elucidated. However, the role of brain stromal cells in facilitating metastatic growth is poorly understood. Astrocytes are glial cells that function in repair and scarring of the brain following injury, in part via mediating neuroinflammation, but the role of astrocytes in melanoma brain metastasis is largely unresolved. Here we show that astrocytes can be reprogrammed by human brain‐metastasizing melanoma cells to express pro‐inflammatory factors, including the cytokine IL‐23, which was highly expressed by metastases‐associated astrocytes in vivo. Moreover, we show that the interactions between astrocytes and melanoma cells are reciprocal: paracrine signalling from astrocytes up‐regulates the secretion of the matrix metalloproteinase MMP2 and enhances the invasiveness of brain‐metastasizing melanoma cells. IL‐23 was sufficient to increase melanoma cell invasion, and neutralizing antibodies to IL‐23 could block this enhanced migration, implying a functional role for astrocyte‐derived IL‐23 in facilitating the progression of melanoma brain metastasis. Knocking down the expression of MMP2 in melanoma cells resulted in inhibition of IL‐23‐induced invasiveness. Thus, our study demonstrates that bidirectional signalling between melanoma cells and astrocytes results in the formation of a pro‐inflammatory milieu in the brain, and in functional enhancement of the metastatic potential of disseminated melanoma cells. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. 相似文献
30.
Liat Apel-Sarid Amalia Levy Gershon Holcberg Eyal Sheiner 《Archives of gynecology and obstetrics》2010,282(5):487-492