全文获取类型
收费全文 | 20670篇 |
免费 | 1384篇 |
国内免费 | 89篇 |
专业分类
耳鼻咽喉 | 258篇 |
儿科学 | 497篇 |
妇产科学 | 224篇 |
基础医学 | 2619篇 |
口腔科学 | 460篇 |
临床医学 | 2187篇 |
内科学 | 4534篇 |
皮肤病学 | 377篇 |
神经病学 | 1700篇 |
特种医学 | 1040篇 |
外国民族医学 | 1篇 |
外科学 | 3302篇 |
综合类 | 168篇 |
一般理论 | 6篇 |
预防医学 | 1113篇 |
眼科学 | 655篇 |
药学 | 1337篇 |
中国医学 | 40篇 |
肿瘤学 | 1625篇 |
出版年
2023年 | 122篇 |
2022年 | 257篇 |
2021年 | 499篇 |
2020年 | 293篇 |
2019年 | 435篇 |
2018年 | 557篇 |
2017年 | 372篇 |
2016年 | 464篇 |
2015年 | 550篇 |
2014年 | 677篇 |
2013年 | 804篇 |
2012年 | 1318篇 |
2011年 | 1317篇 |
2010年 | 776篇 |
2009年 | 645篇 |
2008年 | 1186篇 |
2007年 | 1159篇 |
2006年 | 1136篇 |
2005年 | 1031篇 |
2004年 | 934篇 |
2003年 | 886篇 |
2002年 | 791篇 |
2001年 | 472篇 |
2000年 | 433篇 |
1999年 | 445篇 |
1998年 | 206篇 |
1997年 | 181篇 |
1996年 | 145篇 |
1995年 | 126篇 |
1994年 | 128篇 |
1993年 | 104篇 |
1992年 | 271篇 |
1991年 | 266篇 |
1990年 | 269篇 |
1989年 | 267篇 |
1988年 | 250篇 |
1987年 | 200篇 |
1986年 | 184篇 |
1985年 | 236篇 |
1984年 | 176篇 |
1983年 | 124篇 |
1982年 | 97篇 |
1981年 | 82篇 |
1980年 | 99篇 |
1979年 | 143篇 |
1978年 | 100篇 |
1975年 | 75篇 |
1971年 | 75篇 |
1970年 | 69篇 |
1969年 | 67篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
41.
A 71-year-old man with left periorbital pain and diplopia was hospitalized for evaluation and treatment. He had a past history of untreated diabetes mellitus. Shortly after admission, the patient experienced rapid onset of visual loss in the left eye. MRI and CT showed a lesion expanding from the left orbital apex to the left pterygopalatine fossa. Invasive aspergillosis was diagnosed by open biopsy of intrasinus mucosa via the left maxillary sinus. The patient was treated with voriconazole, an antifungal agent, and marked improvements in left periorbital pain and eye movement were subsequently obtained, although visual acuity was not recovered. This is the first report documenting the clinical utility of voriconazole for sino-orbital invasive aspergillosis. 相似文献
42.
Yanfei L Ma Qingqiang Zeng David W Donley Louis-Georges Ste-Marie J Christopher Gallagher Gail P Dalsky Robert Marcus Erik Fink Eriksen 《Journal of bone and mineral research》2006,21(6):855-864
Transiliac bone biopsies were obtained from 55 women treated with teriparatide or placebo for 12-24 months. We report direct evidence that modeling bone formation at quiescent surfaces was present only in teriparatide-treated patients and bone formation at remodeling sites was higher with teriparatide than placebo. INTRODUCTION: Recombinant teriparatide [human PTH(1-34)], a bone formation agent for the treatment of osteoporosis when given once daily subcutaneously, increases biochemical markers of bone turnover and activation frequency in histomorphometry studies. MATERIALS AND METHODS: We studied the mechanisms underlying this bone-forming action of teriparatide at the basic multicellular unit by the appearance of cement lines, a method used to directly classify surfaces as modeling or remodeling osteons, and by the immunolocalization of IGF-I and IGF-II. Transiliac bone biopsies were obtained from 55 postmenopausal women treated with teriparatide 20 or 40 microg or placebo for 12-24 months (median, 19.8 months) in the Fracture Prevention Trial. RESULTS: A dose-dependent relationship was observed in modeling and mixed remodeling/modeling trabecular hemiosteons. Trabecular and endosteal hemiosteon mean wall thicknesses were significantly higher in both teriparatide groups than in placebo. There was a dose-dependent relationship in IGF-II immunoreactive staining at all bone envelopes studied. The greater local IGF-II presence after treatment with teriparatide may play a key role in stimulating bone formation. CONCLUSIONS: Direct evidence is presented that 12-24 months of teriparatide treatment induced modeling bone formation at quiescent surfaces and resulted in greater bone formation at remodeling sites, relative to placebo. 相似文献
43.
The cause and mechanism of post-carotid endarterectomy hypertension remains unknown. To determine the influence of the sympathetic and renin-angiotensin system, we measured cranial and peripheral plasma levels of catecholamine and renin in patients undergoing carotid endarterectomy. Baseline samples were drawn just before carotid clamping (sample I) and compared with study samples drawn immediately after clamp release (sample II), 2 to 6 hours after surgery (sample III), and then 18 to 24 hours after surgery (sample IV). The patients with post-carotid endarterectomy hypertension had an associated increase of cranial and peripheral norepinephrine levels in the postoperative hypertensive period whereas the patients without post-carotid endarterectomy hypertension did not. This association was most pronounced and statistically significant in cranial samples II (p = 0.032) and III (p = 0.005). Epinephrine and dopamine values did not correlate with post-carotid endarterectomy hypertension. Renin values were higher in cranial than in peripheral samples at time period 2 (p = 0.011), suggestive of a central nervous system Goldblatt phenomenon. However, the renin values did not correlate with post-carotid endarterectomy hypertension. We conclude that post-carotid endarterectomy hypertension is associated with elevated cranial norepinephrine levels, suggestive of a central nervous system sympathomimetic mechanism. Optimal prevention and treatment of this brief but frequently occurring hypertension should include a central-acting sympatholytic agent. 相似文献
44.
45.
K Yamashita K Shigematsu T Maeda Y Ishida M Niwa M Ozaki 《Nihon yakurigaku zasshi. Folia pharmacologica Japonica》1989,93(1):7-15
The antihypertensive effect of bopindolol, a long-acting beta-adrenoceptor blocking agent, was investigated in stroke-prone spontaneously hypertensive rats (SHRSP). One group received tap water during the period of 8 to 32 weeks of age. The average dose of bopindolol administered was calculated from water intake to be approximately 1.4 mg/kg/day. The lowering effect in blood pressure of bopindolol was apparent at the age of 14 weeks, and this continued up to the end of the experiment. Bopindolol significantly reduced the heart rate. Plasma levels of urea nitrogen (BUN), triglyceride, and phospholipid of SHRSP treated with bopindolol were lower than those of the control SHRSP. One of the 8 control SHRSP died, and no rats treated with bopindolol died during the experiment. The histopathological study revealed that three of the control SHRSP had cerebral apoplexy, whereas there was no evidence of cerebral apoplexy in the treated SHRSP. Chronic treatment of bopindolol clearly alleviated myocardial fibrosis and hypertrophic changes in the left ventricular wall of the heart. Decreases in the incidence of proliferative arteritis and malignant nephrosclerosis in the kidney and necrotizing arteritis of the mesenteric arteries were observed in SHRSP treated with bopindolol. The data presented indicate that bopindolol is a powerful antihypertensive agent. 相似文献
46.
47.
Invasion of the skull base by carcinomas: histopathologically evidenced findings with CT and MRI 总被引:3,自引:0,他引:3
Haruhiko Ishida Mitsuhiro Mohri Mutsuo Amatsu 《European archives of oto-rhino-laryngology》2002,259(10):535-539
The depth and extent of the invasion of the skull base by a tumor are the most critical information for successful en bloc resection of the tumor. The only means available for the evaluation of these factors are CT or MRI images. In order to clarify the ability of these imaging modes to delineate the invasion of the skull base, preoperative images of ten patients who underwent en bloc resection of skull base tumors at Kobe University Hospital were compared with the histopathological findings of the resected specimens. CT proved to be superior to MRI for evaluating bone destruction of the skull base. On the other hand, MRI provided more useful information about intracranial invasion than CT. As a hypertrophic linear shadow on Gd-enhanced MRI represented dural invasion or thickened dura mater adjacent to the tumor, this technique should be taken into consideration to determine the dural resection. We concluded that preoperative evaluation of the depth of skull base invasion by both CT and Gd-enhanced MRI is essential for planning complete tumor resection. 相似文献
48.
The preoperative diagnosis of diffuse heterotopic submucosal cystic malformation of the stomach is very difficult to make with upper gastrointestinal (GI) series or endoscopy. We report a case of submucosal cysts associated with an early gastric carcinoma in which ultrasonography (US) and endoscopic ultrasonography (EUS) were very useful in the preoperative diagnosis. 相似文献
49.
Marjolein C. H. van der Meulen Robert Marcus Laura K. Bachrach Dennis R. Carter 《Journal of orthopaedic research》1997,15(3):473-476
We have developed an analytical model of long bone cross-sectional ontogeny in which appositional growth of the diaphysis is primarily driven by mechanical stimuli associated with increasing body mass during growth and development. In this study, our goal was to compare theoretical predictions of femoral diaphyseal structure from this model with measurements of femoral bone mineral and geometry by dual energy x-ray absorptiometry. Measurements of mid-diaphyseal femoral geometry and structure were made previously in 101 Caucasian adolescents and young adults 9–26 years of age. The data on measured bone mineral content and calculated section modulus were compared with the results of our analytical model of cross-sectional development of the human femur over the same age range. Both bone mineral content and section modulus showed good correspondence with experimental measurements when the relationships with age and body mass were examined. Strong linear relationships were evident for both parameters when examined as a function of body mass. 相似文献
50.
S Yoshii T Fuzii T Saitoh R Yamamoto N Ishida Y Hosoi M Tahara 《Nihon Hinyōkika Gakkai zasshi. The japanese journal of urology》1992,83(3):374-382
Thirty-five patients with benign prostatic hyperplasia (age range: 45-88 years; average: 67.5 years) underwent local thermotherapy with prostathermer. Clinical therapeutic effect was evaluated in 30 of the 35 patients: 2 patients interrupting from therapy and 3 receiving pretherapeutic indwelling catheters were not included. A total of 6 treatments (2 per week) were performed, each lasting for 60 minutes. As for subjective improvement, improvement of nocturia was noted in 70.0% of all patients and sense of residual urine in 70.7%. Post-therapeutic nocturnal and daytime decreases in urination frequency were statistically significant (p less than 0.01). Objective improvement in residual urine volume occurred in 19 of the 30 cases, and elevation in uroflowmetric maximal flow rate following therapy was statistically significant (p less than 0.05). Among complications ascribable to catheter insertion were urethral bleeding (3 cases), epididymitis (1 case) and pyuria (1 case). Therapeutic result based primarily on subjective symptoms and partly on objective findings was fairly good in 17 cases (about 57%), and slightly good in 25 cases (about 83%). In conclusion, this therapy seems to be useful in the treatment of benign prostatic hyperplasia. 相似文献