全文获取类型
收费全文 | 9447篇 |
免费 | 524篇 |
国内免费 | 95篇 |
专业分类
耳鼻咽喉 | 73篇 |
儿科学 | 204篇 |
妇产科学 | 74篇 |
基础医学 | 1079篇 |
口腔科学 | 158篇 |
临床医学 | 720篇 |
内科学 | 2729篇 |
皮肤病学 | 79篇 |
神经病学 | 550篇 |
特种医学 | 503篇 |
外科学 | 1706篇 |
综合类 | 49篇 |
预防医学 | 241篇 |
眼科学 | 105篇 |
药学 | 437篇 |
中国医学 | 7篇 |
肿瘤学 | 1352篇 |
出版年
2024年 | 13篇 |
2023年 | 157篇 |
2022年 | 290篇 |
2021年 | 458篇 |
2020年 | 222篇 |
2019年 | 276篇 |
2018年 | 375篇 |
2017年 | 254篇 |
2016年 | 276篇 |
2015年 | 252篇 |
2014年 | 365篇 |
2013年 | 379篇 |
2012年 | 676篇 |
2011年 | 703篇 |
2010年 | 389篇 |
2009年 | 316篇 |
2008年 | 558篇 |
2007年 | 539篇 |
2006年 | 525篇 |
2005年 | 518篇 |
2004年 | 475篇 |
2003年 | 474篇 |
2002年 | 416篇 |
2001年 | 89篇 |
2000年 | 84篇 |
1999年 | 108篇 |
1998年 | 110篇 |
1997年 | 104篇 |
1996年 | 82篇 |
1995年 | 57篇 |
1994年 | 58篇 |
1993年 | 55篇 |
1992年 | 47篇 |
1991年 | 63篇 |
1990年 | 39篇 |
1989年 | 23篇 |
1988年 | 23篇 |
1987年 | 22篇 |
1986年 | 28篇 |
1985年 | 15篇 |
1984年 | 13篇 |
1983年 | 13篇 |
1981年 | 11篇 |
1980年 | 8篇 |
1979年 | 8篇 |
1978年 | 9篇 |
1974年 | 11篇 |
1973年 | 11篇 |
1968年 | 11篇 |
1966年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
Maeda N Osuga K Higashihara H Tomoda K Mikami K Nakazawa T Nakamura H Tomiyama N 《Cardiovascular and interventional radiology》2012,35(1):82-89
Purpose
The purpose of this retrospective study was to investigate the efficacy of transarterial chemoembolization (TACE) using cisplatin as a second-line treatment for advanced hepatocellular carcinoma (HCC) unresponsive to TACE using epirubicin–Lipiodol emulsion at our institution. 相似文献63.
Demetrius M. Kokkinakis S. Clifford Schold Jr. Hiroki Hori Tsutomu Nobori 《Nutrition and cancer》2013,65(3):195-204
Depletion of plasma methionine is expected to inhibit or reverse growth of methionine‐dependent tumors; however, modulation of methionine and other sulfur amino acids is not a trivial task in experimental animals. l‐Methioninase from Pseudomonas putida at 1,000 U/kg causes acute reduction of plasma methionine by 80% in mice, but recovery occurs within 14 hours. Restriction of dietary choline and replacement of dietary methionine with homocystine results in 50% chronic reduction of plasma methionine. A >70% reduction can be accomplished with a diet deficient in methionine, homocystine, and choline, but ultimately this diet is lethal. Plasma methionine can be lowered to a steady state of <5 μM in mice with a combination of dietary restriction of methionine, homocysteine, and choline and synchronous treatments with intraperitoneal injections of 1,000 U/kg L‐methioninase and 25–50 mg/kg homocystine, each administered at 12‐hour intervals. Modulation of plasma methionine by this means causes no weight loss or pathologies in liver or pancreas, and it does not markedly alter levels of cysteine, homocysteine, or glutathione in plasma or in hepatic tissue. When this procedure is applied to athymic mice bearing human medulloblastoma (Daoy) tumors subcutaneously, tumor growth is inhibited. Methionine deprivation arrests mitosis by blocking the cell cycle in G2 and induces apoptosis. Tumor stasis was achieved in 100% of treated animals within 4 days of treatment, and regression was seen in one‐third of animals after a 10‐day period. These data strongly support the use of methionine‐depleting regimens for tumor treatments. 相似文献
64.
65.
Effect of nitric oxide on the contractile function of rat reperfused skeletal muscle 总被引:1,自引:0,他引:1
Ikebe K Kato T Yamaga M Tsuchida T Irie H Oniki Y Takagi K 《The Journal of surgical research》2002,106(1):82-85
BACKGROUND: The involvement of nitric oxide (NO) in ischemia-reperfusion injury remains controversial and has been reported to be both beneficial and deleterious. The purpose of this study was to examine the contribution of NO and superoxide to skeletal muscle function using an ischemic revascularized hind limb model in rats. PATIENTS AND MATERIALS: Warm ischemia produced by vascular pedicle clamping was sustained for 3 h. The animals were divided into four groups according to the solution administrated: (1) saline, (2) N-methyl-L-arginine acetate (L-NMMA), (3) L-NMMA + N-(N-L-g-glutamyl-S-nitroso-l-cysteinyl)glycine (S-nitrosoglutathione), or (4) superoxide dismutase (SOD). Saline, L-NMMA, or L-NMMA + S-nitrosoglutathione was infused for the first 2 h of reperfusion. The SOD was administered as an intravenous bolus 5 min before the onset of reperfusion. Postischemic blood flow was measured by a Doppler flow meter. Muscle contractile function was determined after 24 h of reperfusion. RESULTS: Postischemic blood flow was significantly decreased by the L-NMMA infusion compared with that in the saline-treated group. No significant difference in postischemic blood flow was noted in the saline-, L-NMMA + S-nitrosoglutathione-, and SOD-treated groups. Contractile function of the gastrocnemius muscle in the L-NMMA-and SOD-treated groups, but not in the L-NMMA + S-nitrosoglutathione group, was significantly better than that in the saline-treated group. CONCLUSION: Limiting postischemic blood flow and SOD infusion are both beneficial in decreasing the ischemia-reperfusion injury of skeletal muscle. S-Nitrosoglutathione infusion following suppression of endogenous NO production does not reduce ischemia-reperfusion injury. 相似文献
66.
Although it has been reported that ketamine attenuates hypercapnia-induced cerebral vasodilation, the mechanism remains unknown. Because nitric oxide is involved in cerebral CO2 reactivity, we studied the effects of L-arginine and nitroglycerin on ketamine-mediated attenuation of vascular responses to hypercapnia. Under pentobarbital anesthesia, 16 rabbits underwent closed cranial window preparation. Hypercapnic challenges were repeated after IV saline, ketamine (10 mg/kg, followed by 20 mg x kg(-1) x h(-1)), or ketamine plus either L-arginine (150 mg/kg, followed by 100 mg x kg(-1) x h(-1); n = 8) or nitroglycerin (5 microg x kg(-1) x min(-1) infusion; n = 8). Ketamine reduced hypercapnia-induced cerebral vasodilation (1.27%/mm Hg +/- 0.45%/mm Hg [saline] versus 0.82%/mm Hg +/- 0.53%/mm Hg [ketamine]: P < 0.05), but L-arginine restored reactivity (1.28%/mm Hg +/- 0.73%/mm Hg: P < 0.05 versus ketamine), as did nitroglycerin (1.14%/mm Hg +/- 0.73%/mm Hg [saline] versus 0.56%/mm Hg +/- 0.63%/mm Hg [ketamine]: P < 0.05, and 1.15%/mm Hg +/- 0.74%/mm Hg [ketamine plus nitroglycerin]: P < 0.05 versus ketamine). This indicates that ketamine attenuates cerebral CO2 reactivity, at least in part, via suppression of nitric oxide-cyclic guanosine monophosphate mechanisms in the cerebral vasculature. IMPLICATIONS: The attenuation of cerebral vasodilation to hypercapnia seen under ketamine anesthesia is reversed by L-arginine or nitroglycerin infusion. 相似文献
67.
Tani S Suetsua F Mizuno J Uchikado H Nagashima H Akiyama M Isoshima A Ohashi H Hirano Y Abe T 《Neurologia medico-chirurgica》2010,50(12):1132-1136
Many commercially available hydroxyapatite (HA) spacers for cervical laminoplasty have been introduced but have disadvantages such as lack of plasticity, easy cracking, and occasional difficulty in fixation by sutures. Here we present the short-term results of a newly designed titanium spacer (Laminoplasty Basket) in open-door cervical laminoplasty, and evaluated clinically and radiologically. The titanium box-shaped spacer with two arms for fixation was easily inserted and fixed into the laminoplasty space with 4-mm or 5-mm length screws after the posterior cervical arch was repositioned for the canal expansion. Twenty-one patients with cervical myelopathy due to spondylosis or ossification of the longitudinal ligament or developmental narrow canal observed for more than 6 months postoperatively were enrolled in this study. The neurological condition of these patients improved from 9.4 points on the Japanese Orthopaedic Association scale preoperatively to 13.5 points at 6 months after surgery. Postoperative radiological evaluation showed no laminar closure or implant failure and cervical spine curvature was maintained. These results seemed to have no significant difference compared with those using HA spacers. This titanium spacer is a potential substitute for conventional HA or other similar devices in cervical laminoplasty. 相似文献
68.
Sudo T Murakami Y Uemura K Hayashidani Y Hashimoto Y Ohge H Sueda T 《World journal of surgery》2007,31(11):2230-2235
Background Preoperative biliary drainage (PBD) is associated with bacterial contamination of bile, but the effects of PBD on morbidity
after pancreatoduodenectomy remain controversial. The aim of this study was to characterize bile contamination to develop
successful specific antibiotic prophylactic strategies for pancreatoduodenectomy.
Methods Ninety-one consecutive patients who underwent pancreatoduodenectomy for periampullary tumor were prospectively evaluated.
Prophylactic antibiotics were selected based on preoperative bile cultures. Bile cultures and postoperative complications
were compared in 46 patients who underwent PBD (drainage group) versus 45 patients who did not (nondrainage group).
Results The incidence of positive bile cultures was higher in the drainage group (78%) than in the nondrainage group (36%) (P < 0.001). In the drainage group, positive bile cultures were frequently polymicrobial (61%) and demonstrated resistance to
several antibiotics, including cefazolin (83%), cefmetazole (72%), and cefpirome (64%). Overall morbidity (30% and 22%) and
infectious morbidity (13% and 11%) did not differ significantly between the drainage and nondrainage groups, respectively.
Conclusions PBD had a notable influence on bile microbial contamination, including a higher rate of antibiotic resistance. Therefore,
specific antibiotic prophylaxis based on bile culture is required for preventing infectious complications in pancreatoduodenectomy
patients who undergo PBD. 相似文献
69.
Shimamura N Matchett G Solaroglu I Tsubokawa T Ohkuma H Zhang J 《Journal of neuroscience research》2006,84(8):1837-1847
Ischemic stroke is a major cause of morbidity and mortality in industrialized nations. We tested the effect of postischemic treatment of cyclo-RGDfV (cRGDfV), a selective inhibitor of integrin alphavbeta3, in the middle cerebral artery occlusion (MCAO) model of ischemic stroke in rats. Rats were randomly divided into three groups: sham operation (n = 13), MCAO with no treatment (n = 18), and MCAO with cRGDfV treatment (n = 28). Focal ischemia was induced with the suture occlusion method for 2 hr, and treatment was given 1 hr after reperfusion (3 hr after ischemia). All animals were sacrificed 24 hr after reperfusion. Assessment included neurological scores, infarction volumes, brain water content, Evans blue exudation, IgG exudation, histology, immunohistochemistry, and Western blotting. Treatment with cRGDfV ameliorated neurological deficits, reduced brain edema, and reduced exudation of Evans blue dye and IgG, but failed to reduce infarction volumes. Western blotting showed a reduction in phosphorylation of one subset of vascular endothelial growth factor (VEGF) receptors in the cRGDfV treatment group. Western blotting also demonstrated a significant reduction of fibrinogen in the cRGDfV treatment group. We conclude that poststroke treatment with cRGDfV reduces blood-brain barrier breakdown in focal ischemia, possibly through inhibition of VEGF-mediated vascular breakdown. 相似文献
70.