全文获取类型
收费全文 | 5866篇 |
免费 | 328篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 303篇 |
儿科学 | 68篇 |
妇产科学 | 65篇 |
基础医学 | 929篇 |
口腔科学 | 116篇 |
临床医学 | 325篇 |
内科学 | 1378篇 |
皮肤病学 | 70篇 |
神经病学 | 531篇 |
特种医学 | 185篇 |
外科学 | 767篇 |
综合类 | 60篇 |
预防医学 | 208篇 |
眼科学 | 52篇 |
药学 | 585篇 |
中国医学 | 17篇 |
肿瘤学 | 571篇 |
出版年
2023年 | 27篇 |
2022年 | 69篇 |
2021年 | 114篇 |
2020年 | 66篇 |
2019年 | 82篇 |
2018年 | 95篇 |
2017年 | 79篇 |
2016年 | 97篇 |
2015年 | 80篇 |
2014年 | 136篇 |
2013年 | 157篇 |
2012年 | 238篇 |
2011年 | 321篇 |
2010年 | 149篇 |
2009年 | 134篇 |
2008年 | 248篇 |
2007年 | 269篇 |
2006年 | 242篇 |
2005年 | 290篇 |
2004年 | 304篇 |
2003年 | 256篇 |
2002年 | 235篇 |
2001年 | 242篇 |
2000年 | 239篇 |
1999年 | 206篇 |
1998年 | 71篇 |
1997年 | 73篇 |
1996年 | 73篇 |
1995年 | 53篇 |
1994年 | 62篇 |
1993年 | 52篇 |
1992年 | 158篇 |
1991年 | 146篇 |
1990年 | 140篇 |
1989年 | 120篇 |
1988年 | 118篇 |
1987年 | 114篇 |
1986年 | 113篇 |
1985年 | 96篇 |
1984年 | 68篇 |
1983年 | 54篇 |
1982年 | 33篇 |
1981年 | 24篇 |
1980年 | 22篇 |
1979年 | 39篇 |
1978年 | 26篇 |
1977年 | 27篇 |
1974年 | 23篇 |
1973年 | 19篇 |
1971年 | 20篇 |
排序方式: 共有6230条查询结果,搜索用时 15 毫秒
21.
Ca2+ mobilization and phosphoinositide turnover were examined during phagocytosis of latex particles in cultured chick retinal pigment epithelial cells (RPE cells). Ca2+ influx into cells and Ca2+ efflux from the cells were enhanced by about 1.5-fold and 3-fold compared to control cells, respectively. A high content of Ca2+ in RPE cells has been reported. Therefore, the Ca2+ efflux observed here may be a reflection of Ca2+ release into cytosol from the intracellular storage site(s). In [3H] inositol-prelabeled RPE cells, addition of latex particles elicited decreases in phosphatidylinositol 4,5-bisphosphate and phosphatidylinositol with the concomitant formation of inositol phosphates including inositol trisphosphate, indicating the hydrolysis of phosphoinositides by phospholipase C. These results suggest that phosphoinositide turnover may be closely coupled with Ca2+ mobilization during phagocytosis in RPE cells. 相似文献
22.
The pharmacokinetic properties of lenampicillin (KBT-1585), a new ampicillin ester, were investigated in 41 healthy volunteers. The maximum concentration of ampicillin in serum after oral administration of 400 mg of lenampicillin was 6.5 micrograms/ml at 0.70 h, and that after a equimolar dosage of ampicillin was 2.9 micrograms/ml at 0.87 h. 相似文献
23.
Augmented production of granulocyte-macrophage colony-stimulating factor and alpha/beta interferon in mice inoculated with heat-killed Corynebacterium liquefaciens.
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)
T Yoshida T Hotta K Shimokata M Ichihara K Isobe I Nakashima 《Infection and immunity》1991,59(3):1032-1036
We demonstrated that heat-killed Corynebacterium liquefaciens bacteria, as a known potent host immune activity modulator, stimulate spleen cells to produce granulocyte-macrophage (GM) colony-stimulating factor (CSF) and another CSF with similar activity, as well as alpha/beta interferon, when injected intravenously into mice. Alpha/beta interferon was shown to be produced by C. liquefaciens-activated plastic-G-10 column-adherent cells (A cells) in a thymus-independent manner. In contrast, augmented production of GM-CSF required the action of C. liquefaciens-activated T lymphocytes that collaborated with normal A cells. Non-T spleen cells from C. liquefaciens-stimulated athymic mice, however, produced an alternative CSF that partially replaced GM-CSF. Correspondingly, the numbers of GM-producing CFU developing in cultures of spleen cells from C. liquefaciens-treated euthymic or athymic mice were 10 to 30 times higher than those in cultures of spleen cells from untreated mice. These results suggest that gram-positive rods such as C. liquefaciens activate T and A cells for production of multiple cytokines and that potential cooperative actions of these cytokines underlie the known immunomodulatory action of coryneforms. 相似文献
24.
Kenji Nakashima M.D. Kazuro Takahashi M.D. 《Psychiatry and clinical neurosciences》1988,42(2):297-306
Abstract: The distribution of somatosensory evoked potentials (SEPs) after stimulation of the median nerve at the wrist was examined in 10 normal subjects using isopotential maps. The latencies of continuous negative and positive peaks were measured in each lead. The differences of the potentials at these latencies were measured in all the leads and the isopotential maps were constructed. The distribution of P0–NI was all similar. The latencies of P0 were almost the same in all the leads at about 13 msec. The distribution of NI-PI-NII was divided into three types—N16–P20–N28 localized in the frontal region, N17–P22–N30 localized in the central region and N19–P25–N33 distributed in the parieto-occipito-temporal regions. The distributions of NII-PII and PII-NIII were all similar, with high amplitudes in the central region. The latencies of PII and NIII were almost the same in all the leads at about 45 msec and 68 msec. 相似文献
25.
Arrhythmogenic right ventricular dysplasia/cardiomyopathy assessed with 64-slice computed tomography
Nishiyama Kei; Tadamura Eiji; Kanao Eitaro; Shizuta Satoshi; Furukawa Yutaka; Nakagawa Yoshihisa; Kimura Takeshi; Kita Toru 《European heart journal》2006,27(22):2666
A 69-year-old man was admitted to hospital because of sustainedventricular tachycardia with right bundle branch block morphology.After abolition of ventricular tachycardia, an electrocardiogramshowed atrial fibrillation, complete right bundle 相似文献
26.
27.
Shinji Nakashima Masayuki Morikawa Kanshi Komatsu Akihiro Matsuura Noriyuki Sato Tomio Abe 《The Journal of heart and lung transplantation》2005,24(4):462-469
OBJECTIVE: NKH477 was recently identified as a water-soluble forskolin derivative and was reported to prolong survival of murine cardiac allografts. However, the mechanism of the efficacy is not clear in vivo. The aim of this study was to investigate the immunosuppressive effects of NKH477 on acute lung allograft rejection in the rat model and its mechanism of action in vivo. METHODS: Left lungs were transplanted orthotopically from Brown-Norway donors to Lewis recipients. Recipient rats were untreated or treated daily with different doses of NKH477. Grafts were excised on Day 3 or Day 5 to determine histopathological rejection and expressions of interleukin (IL)-2, IL-4, IL-10, and interferon (IFN)-gamma by enzyme-linked immunosorbent assay. The cytokine expression at Day 3 or Day 5 was also evaluated in recipient spleens by immunohistochemistry. Furthermore, mesenteric lymph node cells from recipients at Day 5 were cultured alone or stimulated with donor antigens for 72 hours to determine cell proliferation by means of thymidine incorporation. RESULTS: NKH477 significantly extended allograft survival time in a dose-dependent manner and reduced histopathological rejection. Treatment with NKH477 inhibited IFN-gamma and IL-10 expression, whereas expression of these cytokines were markedly upregulated in the untreated allografts. Expression of IL-2 and IL-10 also increased in the spleen of untreated allorecipients. NKH477 suppressed expression of both cytokines in the spleen. In addition, lymphocyte proliferation was inhibited in NKH477-treated recipients as compared with untreated recipients. CONCLUSION: These results suggest that NKH477 exerts an antiproliferative effect on lymphocytes in vivo with an altered cytokine profile in rat recipients of lung allografts. 相似文献
28.
Yuji Katayama Naoki Minato Masayuki Sakaguchi Atsushi Nakashima Kazuhiro Hisajima 《Annals of thoracic and cardiovascular surgery》2005,11(6):419-423
Pseudoaneurysm is an uncommon and serious complication of infective endocarditis (IE). It is often fatal because of its rapid progress, high rates of rupture and recurrence, and worsening effects on the systemic condition. We report the rare case of a patient who developed a pseudoaneurysm of the sinus of Valsalva two months after emergency aortic valve replacement for active IE. At the previous operation, we had directly closed a small fistulous hole in the non-coronary sinus of Valsalva using two mattress sutures with autologous pericardial pledgets, because the tissue surrounding the hole did not appear to be infected on visual inspection. A pseudoaneurysm developed from this portion due to detachment of sutures. If the fistula had been completely resected during the first surgery instead of performing a simple closure, the pseudoaneurysm of the sinus of Valsalva would not have formed. However, the primary aim of the first emergency surgery was to spare the life of a critically ill patient. In the second surgery, the pseudoaneurysm was completely resected with the aortic wall--including the non-coronary sinus of Valsalva and the communicating hole. Then, patch plasty of the non-Valsalva sinus was successfully performed. 相似文献
29.
Keiko Imamura Kenji Wada Kenichi Yasui Kazuhiro Nakaso Yasuhiro Watanabe Hisanori Kowa Kenji Nakashima 《Clinical neurology》2004,44(7):446-449
A 61-year-old man had been treated for malignant fibrous histiocytoma with the pulmonary and the lymph node metastasis in the department of orthopedics in our hospital. He was admitted to our department because of an acute onset of conscious disturbance and non-fluent aphasia. Diffusion-weighted imaging (DWI) showed high signal intensity areas in the bilateral cerebella, thalami and posterior lobes. T2WI did not show any mass effects. Enhanced CT did not reveal any enhanced lesion. He was diagnosed as having cerebral embolism, and his conscious disturbance was improved after medication. Eight weeks later, he presented dysphagia, dysarthria, and ataxia in his extremities. DWI showed multiple lesions of low signal intensity located at the identical place where had showed high signal intensity in the initial DWI. T2WI showed high signal intensity area with mass effect. It was indicated that cerebral metastasis might grow after tumorgenic embolism. This is a rare case that tumor emboluses were developed to the metastatic brain tumors. 相似文献
30.
Toshiaki Nakashima Fuminori Goda Jinge Jiang Toshihide Shima Harold M. Swartz 《Magnetic resonance in medicine》1995,34(6):888-892
The partial pressure of oxygen (pO2) of the liver in vivo in unanesthetized mice was determined using electron paramagnetic resonance (EPR) oximetry with India ink. The EPR spectra were obtained using a low-frequency (1.2 GHz) EPR spectrometer with a loop gap cavity resonator. The line width of the India ink used in this experiment was reversibly broadened by oxygen and was particularly sensitive to pO2 below 30 torr. After the administration of India ink into the tail vein, the India ink particles were taken up mainly by Kupffer cells in the liver and in part by phagocytes in the spleen. The pO2 measured in the normal liver was about 14 torr and was constant for the 2-week experimental period. The pO2 decreased when measured at 1, 2, and 6 days after treatment with a hepatotoxin (carbon tetrachloride (CCI4)); within 2 weeks, it returned almost to the initial level. Measurements by EPR at sacrifice of controls and CCI4-treated mice indicated that more than 90% of the India ink went to the liver; the spleen contained 4.7% of total amount in control mice and 8.8% in CCI4-treated mice when measured 2 weeks after the treatment. These data indicate the usefulness of India ink for measuring the pO2 of the liver in vivo and that the pO2 in the Kupffer cells is decreased when the liver is damaged by CCI4. 相似文献