全文获取类型
收费全文 | 9152篇 |
免费 | 341篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 68篇 |
儿科学 | 89篇 |
妇产科学 | 186篇 |
基础医学 | 1043篇 |
口腔科学 | 170篇 |
临床医学 | 535篇 |
内科学 | 2303篇 |
皮肤病学 | 131篇 |
神经病学 | 863篇 |
特种医学 | 506篇 |
外科学 | 1641篇 |
综合类 | 39篇 |
一般理论 | 1篇 |
预防医学 | 249篇 |
眼科学 | 89篇 |
药学 | 642篇 |
中国医学 | 22篇 |
肿瘤学 | 961篇 |
出版年
2023年 | 59篇 |
2022年 | 113篇 |
2021年 | 195篇 |
2020年 | 82篇 |
2019年 | 116篇 |
2018年 | 139篇 |
2017年 | 108篇 |
2016年 | 143篇 |
2015年 | 131篇 |
2014年 | 229篇 |
2013年 | 262篇 |
2012年 | 444篇 |
2011年 | 474篇 |
2010年 | 304篇 |
2009年 | 232篇 |
2008年 | 414篇 |
2007年 | 526篇 |
2006年 | 508篇 |
2005年 | 489篇 |
2004年 | 484篇 |
2003年 | 486篇 |
2002年 | 529篇 |
2001年 | 241篇 |
2000年 | 277篇 |
1999年 | 262篇 |
1998年 | 164篇 |
1997年 | 128篇 |
1996年 | 126篇 |
1995年 | 88篇 |
1994年 | 86篇 |
1993年 | 59篇 |
1992年 | 164篇 |
1991年 | 154篇 |
1990年 | 143篇 |
1989年 | 135篇 |
1988年 | 133篇 |
1987年 | 111篇 |
1986年 | 105篇 |
1985年 | 105篇 |
1984年 | 61篇 |
1983年 | 53篇 |
1981年 | 31篇 |
1979年 | 57篇 |
1975年 | 34篇 |
1974年 | 26篇 |
1973年 | 27篇 |
1972年 | 34篇 |
1971年 | 26篇 |
1969年 | 34篇 |
1968年 | 28篇 |
排序方式: 共有9538条查询结果,搜索用时 15 毫秒
991.
Xu H Regino CA Bernardo M Koyama Y Kobayashi H Choyke PL Brechbiel MW 《Journal of medicinal chemistry》2007,50(14):3185-3193
Two different fourth-generation (G4) polyaminonamido dendrimer-based magnetic resonsance (MR) agents were prepared by a new synthetic approach wherein tert-butyl-protected forms of 2-(4-isothiocyanatobenzyl)-6-methyldiethylenetriamine pentaacetic acid (1B4M-DTPA), bearing either an isothiocyanate or a succinimidyl ester moiety, respectively, were conjugated to the primary amines of the dendrimer. Purification was facilitated using a solid phase, N-(2-aminoethyl)aminomethyl polystyrene. After Gd(III) incorporation, molar relaxivity measurements of both new dendrimer-based agents as compared to a G4 agent prepared by an aqueous chemistry route indicated no significant changes in relaxivity. Comparative MR imaging revealed equivalent enhancement of the vessels and organs such as the kidney and liver, although slightly different vascular clearance rates were observed. This general synthesis provides a procedure for preparation of dendrimer-based MR agents for clinical applications with higher yields and efficiency while enhancing versatility. The latter aspect is further demonstrated by preparation of a novel maleimide analog of 1B4M-DTPA from a key synthetic intermediate aniline derivative. 相似文献
992.
This article is an overview of the immunomodulatory effects of apheresis in renal diseases, especially primary and secondary
glomerulonephritis, and the clinical evidence for the efficacy of apheresis therapy. Permeability factor(s) derived from circulating
T cells are speculated to have a crucial role in the proteinuria of nephrotic syndrome (NS). Plasma exchange (PE); immunoadsorption
plasmapheresis (IAPP), using protein A sepharose cartridges; low-density lipoprotein apheresis; and lymphocytapheresis (LCAP)
have been used to remove such factors or pathogenic T cells. Other glomerular diseases induced by specific antibodies such
as anti-glomerular basement membrane antibodies, anti-neutrophil cytoplasmic antibodies, and immune-complexes have also been
treated with PE, double-filtration plasmapheresis, IAPP, and LCAP. Recommendations, based on the evidence from recent randomized
controlled studies, have been established in apheresis therapy for various glomerular diseases. 相似文献
993.
Masaki Y Yamazaki M Okawa A Aramomi M Hashimoto M Koda M Mochizuki M Moriya H 《Journal of spinal disorders & techniques》2007,20(1):7-13
OBJECTIVE: We compared the surgical outcome of anterior decompression with spinal fusion (ASF) with the surgical outcome of laminoplasty for patients with cervical myelopathy due to ossification of the posterior longitudinal ligament. METHODS: The study group comprised 19 ASF patients (A-group) and 40 laminoplasty patients (P-group) treated from 1993 to 2002 with 1 year or longer follow-up. The Japanese Orthopedic Association scoring system was used to evaluate cervical myelopathy, and the recovery rate calculated 1 year after surgery. RESULTS: The mean recovery rate was 68.4% in the A-group and 52.5% in the P-group (P<0.05). Fifteen patients had a recovery rate less than 40%: 2 in the A-group and 13 in the P-group. One P-group patient and none of the A-group patients developed postoperative aggravation of their neurologic status. The P-group was divided into 2 subgroups: a good outcome group comprising patients whose recovery rate was 40% or higher (n=27) and a poor outcome group comprising patients whose recovery rate was less than 40% (n=13). The mean age at surgery was 59.9 years in the good outcome group and 68.0 years in the poor outcome group (P<0.05). The mean range of intervertebral mobility at maximum cord compression level before surgery was 6.9 degrees in the good outcome group and 10 degrees in the poor outcome group (P<0.05). CONCLUSIONS: These results demonstrated that the surgical outcome of ASF was superior to the surgical outcome of laminoplasty. Elderly patients treated with laminoplasty showed an especially poor surgical outcome. We suggest that hypermobility of vertebrae at the cord compression level is a risk factor for poor surgical outcome after laminoplasty. Based on these results, we recommend that ASF should be the first choice of treatment for patients with significant ossification of the posterior longitudinal ligament and a hypermobile cervical spine. When laminoplasty is used for such cases, the addition of posterior instrumented fusion would be desirable for stabilizing the spine and decreasing damage to the spinal cord. 相似文献
994.
Endo S Tsubochi H Nakano T Koyama S Sohara Y 《General thoracic and cardiovascular surgery》2007,55(8):328-330
Chronic diaphragmatic hernia is a rare entity and requires surgical intervention when it is diagnosed. We report three patients
with chronic diaphragmatic hernia that followed a diagnosis of diaphragmatic abnormality with no previous chest injury. Operative
findings suggested a diaphragmatic defect in a congenitally weak area. All patients were satisfied with the resolution of
their preoperative discomfort and their improved respiratory function after repair using Marlex mesh sheets via thoracotomy
and laparotomy. Chronic diaphragmatic hernia should be considered even in patients who had no previous chest injury. 相似文献
995.
Optical probes that yield high target-to-background ratios are necessary to detect microfoci of cancer that would otherwise escape detection with white light imaging. Target-specific activation of the optical signal at tumor foci is one mechanism by which high target and low background signal can be achieved. Here, we describe a two-step activation process in which the tumors are first pretargeted with a nonfluorescent biotinylated monoclonal antibody [cetuximab (Erbitux) targeting human epidermal growth factor receptor type 1 (HER1)]. Following this, a second agent, neutravidin-BODIPY-FL fluorescent conjugate, is given and binds to the previously targeted antibody, resulting in an approximately 10-fold amplification of the optical fluorescence signal, leading to high tumor-to-background ratios. Spectral fluorescence imaging was done in a mouse model of peritoneal metastasis using a HER1-overexpressing cell line (A431) after pretargeting with biotinylated cetuximab and 3 h after administration of neutravidin-conjugated BODIPY-FL. Both aggregated tumors as well as small cancer implants were clearly visualized in vivo. For lesions approximately 0.8 mm or greater in diameter, the spectral fluorescence imaging had a sensitivity of 96% (178 of 185) and a specificity of 98% (188 of 191). This two-step activation paradigm (pretargeting followed by neutravidin-biotin binding with an attached activatable fluorophore) could be useful in tumor-specific molecular imaging of various targets to guide surgical resections. 相似文献
996.
Nakabayashi H Nakashima M Hara M Toyonaga S Yamada SM Park KC Shimizu K 《Cancer letters》2007,246(1-2):182-189
RCAS1, one of the tumor cell surface antigens, is strongly expressed in aggressive tumors. RCAS1 suppresses the in vitro growth of immune effector cells. We investigated the expression of RCAS1 in 57 gliomas using immunohistochemistry. Furthermore, we examined the association of the RCAS1 expression with the infiltration of tumor infiltrating lymphocyte (TIL). RCAS1 overexpression was significantly correlated with high histological grade and poor prognosis. Reduced infiltration and increased apoptosis of TILs was observed in RCAS1-positive regions. Apoptotsis of TILs appeared to be induced by RCAS1. RCAS1 expression in gliomas may play roles in tumor progression and tumor immune escape. 相似文献
997.
Curcumin inhibits the formation of capillary-like tubes by rat lymphatic endothelial cells 总被引:2,自引:0,他引:2
The natural pigments curcumin and berberine have been shown to exhibit a variety of pharmacologic effects including anti-inflammatory, anti-cancer, and anti-metastatic properties. Here, we investigated the anti-lymphangiogenic effect with an in vitro tube-forming model using conditionally immortalized lymphatic endothelial TR-LE cells, a newly established cell line originating from the thoracic duct of a transgenic rat expressing the temperature-sensitive SV40 large T-antigen. Curcumin, but not berberine, exhibited a dose-dependent inhibition of the formation of capillary-like tubes by TR-LE cells without affecting cell viability and adhesion to Matrigel. To address the molecular mechanisms involved, we performed experiments with specific inhibitors against putative targets of curcumin, including IkappaB kinase (IKK), epidermal growth factor receptor (EGFR), phosphatidylinositol-3 kinase (PI3K)/Akt, and matrix metalloproteinases (MMPs). While the IKK-2 inhibitor VI and EGFR tyrosine kinase inhibitors gefitinib and PD153035 had no effect, both the PI3K inhibitor LY294002 and the MMP inhibitor GM6001 shortened the tubes by approximately 50%. Western blot analysis and gelatin zymography revealed that curcumin, but not berberine, has an inhibitory effect on the phosphorylation of Akt and enzymatic activity of MMP-2 in TR-LE cells. These results suggest that curcumin exerts its inhibitory effect on lymphangiogenesis partly through Akt and MMP-2. 相似文献
998.
999.
Ayano Fukushima Yoshiko Ichimura Shoko Obata Misaki Kinoshita‐Ise Yumi Fujio Mitsuhiro Takeno Izumi Konohana 《The Journal of dermatology》2017,44(7):830-835
Thymoma‐associated multi‐organ autoimmunity disease (TAMA) is a rare paraneoplastic disorder, clinicopathologically similar to graft‐versus‐host disease (GVHD). Many reported cases follow a difficult course; half of them die from serious infectious diseases subsequent to immunosuppression induced by chemotherapy for unresectable thymoma, or intensive therapies including systemic steroids for complicating autoimmune diseases and GVHD‐like symptoms. We report a patient whose skin symptoms were improved subsequently to total thymectomy. The patient also presented with hypogammaglobulinemia, which led to the diagnosis of complicated Good syndrome. Taking account of her immunodeficient condition, antibiotics and i.v. immunoglobulin were administrated promptly on onset of bacterial pneumonia, which was successfully treated. According to a review of the published work, treatments with systemic steroids for skin symptoms have limited effects and may contribute to serious infection. Our case indicates that successful treatment of thymoma itself may lead to the amelioration of the disease. The management priority should be given to the treatment of thymoma and the control of subsequent immune abnormality other than GVHD‐like erythroderma. 相似文献
1000.
Akira Kado Yukiko Inoue Kyoji Moriya Takeya Tsutsumi Kazuhiko Ikeuchi Kazuya Okushin Hiroshi Yotsuyanagi Kazuhiko Koike Mitsuhiro Fujishiro 《Hepatology research》2023,53(6):497-510