全文获取类型
收费全文 | 13966篇 |
免费 | 585篇 |
国内免费 | 68篇 |
专业分类
耳鼻咽喉 | 110篇 |
儿科学 | 290篇 |
妇产科学 | 197篇 |
基础医学 | 1867篇 |
口腔科学 | 341篇 |
临床医学 | 809篇 |
内科学 | 3524篇 |
皮肤病学 | 269篇 |
神经病学 | 1025篇 |
特种医学 | 716篇 |
外科学 | 2417篇 |
综合类 | 36篇 |
一般理论 | 1篇 |
预防医学 | 413篇 |
眼科学 | 186篇 |
药学 | 915篇 |
中国医学 | 22篇 |
肿瘤学 | 1481篇 |
出版年
2023年 | 58篇 |
2022年 | 114篇 |
2021年 | 227篇 |
2020年 | 108篇 |
2019年 | 141篇 |
2018年 | 202篇 |
2017年 | 162篇 |
2016年 | 227篇 |
2015年 | 245篇 |
2014年 | 336篇 |
2013年 | 399篇 |
2012年 | 678篇 |
2011年 | 711篇 |
2010年 | 379篇 |
2009年 | 392篇 |
2008年 | 708篇 |
2007年 | 793篇 |
2006年 | 742篇 |
2005年 | 857篇 |
2004年 | 846篇 |
2003年 | 800篇 |
2002年 | 748篇 |
2001年 | 360篇 |
2000年 | 324篇 |
1999年 | 321篇 |
1998年 | 243篇 |
1997年 | 199篇 |
1996年 | 197篇 |
1995年 | 164篇 |
1994年 | 170篇 |
1993年 | 133篇 |
1992年 | 233篇 |
1991年 | 232篇 |
1990年 | 230篇 |
1989年 | 208篇 |
1988年 | 197篇 |
1987年 | 177篇 |
1986年 | 170篇 |
1985年 | 137篇 |
1984年 | 134篇 |
1983年 | 99篇 |
1982年 | 68篇 |
1981年 | 72篇 |
1980年 | 65篇 |
1979年 | 67篇 |
1978年 | 61篇 |
1977年 | 51篇 |
1974年 | 40篇 |
1971年 | 41篇 |
1970年 | 43篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Joji Ishikawa Satoshi Hoshide Seiichi Shibasaki Yoshio Matsui Tomoyuki Kabutoya Kazuo Eguchi Shizukiyo Ishikawa Thomas G Pickering Kazuyuki Shimada Kazuomi Kario 《Hypertension research》2006,29(3):153-159
Morning blood pressure is reported to be more closely related to hypertensive organ damages such as left ventricular mass index, microalbuminuria and silent cerebral infarcts, than blood pressure at other times of the day. Morning blood pressure may play an important role in the pathogenesis of hypertensive target organ damage. Increased sympathetic nerve activity is reported to be one of the mechanisms of morning hypertension; however, there are no available data that show whether strict home blood pressure control, especially in the morning period, can reduce target organ damage. The Japan Morning Surge-1 (JMS-1) study includes hypertensive outpatients with elevated morning systolic blood pressure (>or=135 mmHg) as assessed by self-measured blood pressure monitoring at home. All enrolled patients are under stable antihypertensive medication status. Exclusion criteria are arrhythmia, chronic inflammatory disease, and taking alpha-blockers or beta-blockers. The target number of patients to be enrolled in the JMS-1 study is 600, and the aim is to evaluate differences in the markers of hypertensive target organ damage, such as brain natriuretic peptide and the urinary albumin excretion/creatinine ratio. All of the patients are randomized to an experimental group or a control group, with randomization to be carried out by telephone interviews with the patients' physicians. In the experimental group, patients begin taking additional antihypertensive medication just before going to bed. This consists of doxazosin 1 mg/day, which then is increased to 2 mg/day and 4 mg/day, with a beta-blocker added after a 1-month interval until the morning systolic blood pressure is controlled to less than 135 mmHg. Patients in the control group continue the treatment they are receiving at the enrollment for 6 months. Blood pressure levels, adverse effects, and hypertensive target organ damage before and after the study are evaluated. In the JMS-1 study, we will evaluate whether strict morning blood pressure control by sympathetic nervous system blockade using an alpha-blocker, doxazosin, and with the addition of a beta-blocker if needed, can reduce hypertensive target organ damage. 相似文献
32.
33.
胫骨前肌疲劳时比目鱼肌诱发肌电图H波的变化及其机制探讨 总被引:5,自引:0,他引:5
为了解主动肌疲劳时拮抗肌脊髓运动神经元兴奋性变化的规律 ,本研究采用踝关节背屈运动形式 ,对胫骨前肌 (主动肌 )疲劳状态下的比目鱼肌 (拮抗肌 )诱发肌电图H波成分进行了观察。并以压迫阻断胫骨前肌Ⅰa类神经纤维传导的方法 ,对比目鱼肌H波变化机制进行了分析探讨。结果发现 :(1)胫骨前肌疲劳后 ,比目鱼肌H波明显受到抑制 ,与安静时比较呈非常显著性差异 ;(2 )胫骨前肌Ⅰa类神经纤维传导被阻断后 ,比目鱼肌H波的抑制现象没有解除。表明 ,胫骨前肌疲劳时比目鱼肌H波被抑制的原因 ,可能是由于主动肌内的代谢产物激活了Ⅲ·Ⅳ类神经纤维的感受器 ,Ⅲ·Ⅳ类神经纤维的传入冲动增加 ,使Ⅰa抑制性中间神经元被激活 ,导致拮抗肌脊髓运动神经元的兴奋性受到了抑制 相似文献
34.
A 68-year-old man noticed weakness in both legs, which worsened rapidly with additional urinary disturbance. At the time of admission, a neurological examination revealed spastic paraplegia. Sensation was intact. Magnetic resonance imaging (MRI) did not show any lesions in the spinal cord. Thereafter, sensory disturbance under Th5 level and weakness in both hands developed gradually. Seven months after the onset, he noticed pain of the right upper arm. MRI showed an epidural mass at the level between the lower cervical and the upper thoracic spine. Histological examination of the epidural mass revealed Ki-1 lymphoma. In this case, the diagnosis was difficult, because lymphoma did not present epidural mass in the early stage. We speculate that spinal epidural lymphoma might disturb venous circulation and cause myelopathy in this patient. 相似文献
35.
Hayato Inoue Keiichi Iwabuchi Sadahito Kuwao Kiyoshi Kasai Masayuki Furuhata Toru Kameya 《Pathology international》1992,42(10):760-765
A case of inflammatory pseudosarcoma of the urinary bladder in a 35 year-old Japanese male is presented. This benign lesion can easily be mistaken for spindle cell sarcoma since it consists of rhabdomyoblast like elongated strap cells showing infiltrative growth, and whether it is benign or malignant is difficult to determine by microscopic examination. In this case, spindle cell proliferation extended among bundles of the superficial muscle layer. However, no abnormal mitoses, severe nuclear atypia or cellular pleomorphism could be seen, thus indicating inflammatory pseudosarcoma. Although the lesion was not completely resected, no recurrent disease has been clinically observed for two years following transurethral resection. Urologists and surgical pathologists must be able to detect this lesion in order to avoid unnecessary surgical procedures. Acta Pathol Jpn 42: 760 765,1992. 相似文献
36.
Eichi Itadera Yoshimasa Miyake Yoichi Nakatsuka Hirofumi Akazawa Shigeru Mitani Kiyoshi Aoki 《Journal of orthopaedic science》1996,1(4):252-258
We report satisfactory results with a new operative treatment, conducted via an extensive anterolateral approach, involving
360 degree circumferential capsulotomy, for residual subluxation in congenital dislocation of the hip (CDH). Long-term radiographic
results of this procedure (group A) were compared retrospectively with the results of partial capsulotomy (group B), which
preserved the posteroinferior joint capsule. The mean center edge angle in group A (22.5°) was greater than that in group
B (16.0°). Satisfactory results were achieved in 11 of 15 hips (73%) (Severin class I or II) in group A, and in 5 of 12 hips
(42%) in group B. These results suggest that whole circumferential capsulotomy can remove obstacles to complete reduction,
and that acetabular development can be expected in hips reduced by the procedure, without the performance of innominate osteotomy.
We believe that our technique is a useful alternative for the treatment of residual subluxation in CDH. 相似文献
37.
Mary Steidl Matsui Isabella Illarda Nianci Wang Vincent A. DeLeo 《Experimental dermatology》1993,2(6):247-256
Abstract Several lines of evidence implicate protein kinase C (PKC) in the development of basal cell and squamous cell carcinomas, tumors which originate from epidermal keratinocytes. To examine PKC in a model relevant to human skin, we exposed normal human epidermal keratinocytes (NHEK) in serum-free media to a variety of PKC agonists and antagonists. NHEK PKC activity increased up to 10-fold within the 1st hour of exposure to tetradecanoyl phorbol acetate (TPA), and gradually returned to control values within 72 h. TPA-induced PKC activity was enhanced by pretreatment of cultures with protein and RNA synthesis inhibitors. TPA-induced growth arrest and differentiation was antagonized by staurosporine. Down-regulation by bryostatin pretreatment blocked TPA-stimulated differentiation. Our overall conclusion is that activation of PKC in cultured human keratinocytes is required for differentiation. These results are crucial to the analysis of compounds suspected of promoting or inhibiting epidermal tumors. 相似文献
38.
Hiroshi Uno Yoshihiro Izawa Kiyoshi Sagara Tamotsu Koyama Tokutaro Makita Chia-Yuan Hsu-Chang Mitsugi Sugiyama 《Journal of bone and mineral metabolism》1990,8(1):10-16
The effect of 1α-hydroxyvitamin D3 (1α(OH)D3) on the metabolic bone disorders developed in gastrectomized rats were investigated biochemically and histomorphologically.
1α(OH)D3 was suspended in 0.2 % Triton-X-100 aqueous solution after dissolving in a very small amount of ethanol, was given orally
to the rats for 10 weeks. The sham operated animals and the gastrectomy control animals received the vehicle alone. Gastrectomy
was followed by the development of the metabolic bone disorders after 10 weeks of observation. This was characterized by reduction
in ash content of the femur and histologically by a disappearance of the trabecular bone in tibial metaphysis. Decrease Ca
absorption from the intestines was demonstrated by a radiotracer technique. Biochemical studies showed significant decreases
in serum 25(OH)D concentration in gastrectomized rats. These findings suggest that gastrectomy partially impairs intestinal
absorption of calcium and results in a negative calcium balance, which may contribute to the development of bone metabolic
disorders in rats. The administration of 1α(OH)D3 increased dose-dependently serum calcium and Ca absorption from the intestine and prevented the development of bone metabolic
disorders histomorphologically. 相似文献
39.
Kiyoshi Uchide Hirohisa Ueno Noboru Takizawa Yasunori Okada 《Journal of bone and mineral research》2003,18(2):381-382
Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) were measured in a mild case of dyssegmental dysplasia. X-ray pictures of a female baby born vaginally at 39 weeks of gestation showed short, bent, dumbbell-shaped long bones of the limbs and profound dyssegmental ossification in the spine, findings characteristic of dyssegmental dysplasia. When the levels of MMP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2 were measured, the levels of MMP-2 and TIMP-1 were significantly reduced. This case might provide a clue to disclose the etiology of dyssegmental dysplasia. 相似文献
40.
Y Watanabe H Kanayama K Kato T Kanbe H Matsui S Mitani M Yoshino Y Nishiyama M Kanzaki 《Nihon Kyōbu Shikkan Gakkai zasshi》1991,29(10):1311-1316
A 56-year-old man was admitted to our hospital with right chest pain. Chest X-ray, CT scan and MRI revealed a chest wall tumor and enlarged mediastinal lymph nodes. Percutaneous lung biopsy was performed, and the pathological diagnosis of pleomorphic rhabdomyosarcoma was obtained. The only significant abnormal laboratory finding was elevation of serum NSE (24.5 ng/ml). Although chemotherapy (VAC-ADM) and radiation therapy were performed, the patient died about 7 months after admission. To our knowledge, only 17 cases of chest wall rhabdomyosarcoma have been reported in Japan. 相似文献