首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2961篇
  免费   176篇
  国内免费   15篇
耳鼻咽喉   23篇
儿科学   112篇
妇产科学   22篇
基础医学   365篇
口腔科学   48篇
临床医学   228篇
内科学   761篇
皮肤病学   65篇
神经病学   149篇
特种医学   88篇
外科学   485篇
综合类   19篇
预防医学   76篇
眼科学   218篇
药学   249篇
中国医学   6篇
肿瘤学   238篇
  2023年   35篇
  2022年   43篇
  2021年   116篇
  2020年   62篇
  2019年   66篇
  2018年   94篇
  2017年   60篇
  2016年   60篇
  2015年   68篇
  2014年   98篇
  2013年   127篇
  2012年   146篇
  2011年   163篇
  2010年   83篇
  2009年   60篇
  2008年   89篇
  2007年   105篇
  2006年   116篇
  2005年   116篇
  2004年   108篇
  2003年   109篇
  2002年   86篇
  2001年   93篇
  2000年   115篇
  1999年   113篇
  1998年   31篇
  1997年   25篇
  1996年   27篇
  1995年   30篇
  1994年   25篇
  1993年   23篇
  1992年   74篇
  1991年   67篇
  1990年   78篇
  1989年   62篇
  1988年   50篇
  1987年   40篇
  1986年   32篇
  1985年   31篇
  1984年   32篇
  1983年   18篇
  1979年   20篇
  1978年   10篇
  1975年   14篇
  1974年   11篇
  1973年   10篇
  1972年   11篇
  1969年   15篇
  1968年   15篇
  1967年   14篇
排序方式: 共有3152条查询结果,搜索用时 31 毫秒
1.
2.
MK-0787 (Imipenem)/MK-0791 (Cilastatin sodium), a new compound of Thienamycin, was administered in treatment of 35 patients (36 cases) with chronic complicated UTI or for prevention of serious infections with much complicated factors. The patients were principally treated at a daily dose of 1 g for over 10 days. The efficacy rate of 26 patients who were evaluable in the early phase (4-7 days) was 88.5%, while it became up to 92.3% in the final phase judgment. As for clinical usefulness, the result was obtained to be as high as that of the clinical efficacy. In bacteriological study, 35 strains were clinically isolated including 7 strains of P. aeruginosa from UTI. All the strains disappeared with an eradication rate of 100% after treatment. Strains appearing after Imipenem/Cilastatin sodium treatment mainly consisted of fungi. Usefulness judgements tended to be greater in the final phase than in the early phase. As for side effects, vomiting was recorded in one case, in which the administration was discontinued. In laboratory findings there were 3 cases with elevated GPT, 2 cases with elevated GOT, one case with elevated gamma-GTP, one with thrombocytopenia, and one with eosinophilia each, but these abnormal values were slight and transient. In summary our clinical study showed that Imipenem/Cilastatin sodium was a very effective antibiotic in treatment on moderate or serious UTI or preventive use for infections in compromised hosts. Considering the features of this agent, it might be more effective and useful for clinical use in treatment on polymicrobial infections including stubborn organisms than any other antimicrobial compounds. Furthermore, it was safe and well tolerable in a long term treatment.  相似文献   
3.
4.
We herein report a rare case of portsite metastasis of gallbladder carcinoma which occurred after laparoscopic cholecystectomy. A 64-year-old man underwent laparoscopic cholecystectomy at another hospital for symptomatic cholecystolithiasis. The histological examination revealed an adenocarcinoma of the gallbladder infiltrating the entire wall. Despite the physician's advice the patient refused any additional treatment. Thirteen months after surgery he visited our hospital because of a palpable mass at the scar of the right trocar incision. The nodule was removed and histological examination confirmed metastasis from the gallbladder carcinoma.  相似文献   
5.
Prednisolone concentrations in cornea, aqueous humor, and vitreous humor and the residual amount in conjunctival tissue were assayed by high-performance liquid chromatography during a 14-hour period after subconjunctival injection of prednisolone sodium succinate in rabbits. Prednisolone was concentrated in the corneal epithelium and reached a peak within 5 min, whereas the peak level of prednisolone in stroma-endothelium was achieved 1 h after the injection. There was an apparent linear binding of prednisolone with the ocular tissue homogenates and fluids except for the vitreous humor. However, the protein binding of prednisolone with vitreous humor showed marked concentration dependency. A pharmacokinetic model involving a rapid conversion to prednisolone from its ester prodrug, first-order transfer to various tissues, and first-order elimination of unbound prednisolone from vitreous humor succeeded in predicting the observed concentration-time profiles of prednisolone in various ocular tissues and fluids after subconjunctival injection at three different doses: 0.1, 1.0, and 10.0 mg/kg. The present model predicted that absorption into precorneal area and epithelium and direct penetration into aqueous humor and vitreous humor are 1.7, 0.1, and 0.2% of the applied dose, respectively, and that almost the entire dose (98%) is absorbed into the systemic circulation, with a half-life of 38 min.  相似文献   
6.
Summary Healing of an experimental bony defect in the rat's tibia was studied with an immunofluorescent technique to clarify when and where substance P (SP) and calcitonin gene-related peptide (CGRP) would develop. The normal tibia showed a few SP- and CGRP-immunofluorescent nerve fibres. In the experimental tibia, the number of these fibres increased on the 6th day after operation, reached a peak of proliferation on the 15th day and reverted to normal after the 24th day. The changes were associated with the development and decay of callus tissue suggesting that harmful stimuli from the injured site in a bone could be mediated by sensory nerves throughout the repair period. Most of the SP- and CGRP-immunofluorescence was seen near the vessels, frequently in the same nerve fibres. The SP- and CGRP-immunofluorescent nerves seemed to take part jointly in callus formation through the enhancement of local blood flow.
Résumé Le procesus de guérison d'une perte de substance osseuse expérimentale a été étudié sur le tibia du rat par immunofluorescence afin de déterminer quand et où la substance P (SP) et la calcitonine peptide d'origine génique (CGRP) se développeraient. Le tibia normal ne montre qu'un petit nombre de fibres nerveuses immunofluorescentes SP et CGRP. Dans le tibia d'expérimentation, les fibres nerveuses immunofluorescentes SP et CGRP augmentent en nombre à partir du 6ème jour, atteignent leur maximum de prolifération le 15ème jour et reviennent à l'état normal après le 24ème jour post-opératoire. Ces modifications sont étroitement associées au développement et à la disparition du cal, suggérant ainsi que les stimuli nocifs provenant de la lésion osseuse pourraient être inactivés par les nerfs sensitifs durant la période de réparation. En outre, la plus grande partie de l'immunofluorescence SP et CGRP a été observée à proximité des vaisseaux, souvent dans les mêmes fibres nerveuses. Il semble que les nerfs immunofluorescents SP et CGRP participent conjointement à la formation du cal en augmentant la vascularisation locale.
  相似文献   
7.
Chymase is known to generate angiotensin II in the vascular wall. In this study we investigated a novel role for chymase other than angiotensin II production in vascular proliferation after balloon injury. Chymase promoted the migration of vascular smooth muscle cells in the matrix-coated invasion chambers and activated promatrix metalloproteinase-2 obtained from the culture medium of vascular smooth muscle cells. Two weeks after balloon injury, significant neointimal formation was found in dog carotid arteries. After injury, active matrix metalloproteinase-2 was increased in parallel with the augmentation of chymase activity that was seen in the proliferating region of the vascular wall. The oral administration of NK3201 (1 mg/kg per day), a chymase inhibitor, prevented neointimal formation and significantly suppressed both active matrix metalloproteinase-2 and chymase activities 2 weeks after injury. These results suggest that chymase inhibitors can prevent the development of intimal hyperplasia via the inhibition of matrix metalloproteinase-2 activation in balloon-injured arteries.  相似文献   
8.
Endoscopic placement of metal stents are used widely for patients with esophageal obstruction and fistula due to progressive esophageal cancer, but cause high rate of severe complications associated with the immediate causes of death. To determine severe complications caused by stents, we studied clinical data and autopsy of six patients who had been treated with stents for inoperable progressive esophageal cancer. Occording to the clinical records only two patients had severe complications due to stents. But at autopsy, three patients had massive hemorrhage in the stent placement, one patient had mediastinitis, and one patient were in imminent danger of perforation whose stent had been incorporated into the adventitia of the wall. More severe complications were revealed than those expected clinically. Endoscopic placement of metal stents have a great deal for the improvement of quality of life. But we should carefully decide the indication because endoscopic placement of metal stents could cause severe complications associated with the immediate causes of death.  相似文献   
9.
We conducted a noninvasive near-infrared spectroscopy (NIRS) study using the game of rock, paper, scissors (RPS) as a simple neurocognitive task for the prefrontal cortex (PFC) in 15 healthy volunteers. We employed an opposite “to lose” RPS task coupled with a normal “to win” RPS task, since the former requires inhibition of behavior, one of the most important functions of the prefrontal cortex. During the NIRS examination, subjects had to present one of the three RPS hands in response to hands displayed randomly on a computer screen every 1.5 s, and were required to show hands that lose to the computer, or that beat the computer. We measured the relative concentrations of oxyhemoglobin (oxy-Hb) using the prefrontal probes of the NIRS system during the tasks. The increases in oxy-Hb during the “to win” RPS task were small, but were quite large and laterally dominant during the “to lose” RPS task. The difference between the two tasks might have been due to the participants’ cognitive conflict with losing on the RPS. We conclude that losing is better than winning on the RPS as a sensitive indicator in the NIRS examination of PFC.  相似文献   
10.
We used morphological, biochemical and immunohistochemical methods to assess the response of Müller cells after experimental lensectomy-vitrectomy in rabbits. We observed widened intercellular spaces between the Müller cells and nerve fibers of ganglion cells, and increased electron opacity in the Müller cells of eyes injected with silicone oil. No apparent morphological changes were detected in the Müller cells of air-injected eyes. The specific and total activities of Müller cell-marker enzymes (glucose 6-phosphatase and glutamine synthetase) showed an initial increase, followed by a decrease. Glial fibrillary acidic protein immunoreactivity was not found in the Müller cells of the normal rabbit retina but was exhibited after surgery. Our results showed that markers of Müller cells associated with glycogenolysis and/or gluconeogenesis, glutamate-glutamine cycle and cytoskeletal protein metabolism were affected by the experimental lensectomy-vitrectomy.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号