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   25012篇
  免费   1224篇
  国内免费   204篇
耳鼻咽喉   231篇
儿科学   636篇
妇产科学   212篇
基础医学   3105篇
口腔科学   377篇
临床医学   1713篇
内科学   6858篇
皮肤病学   372篇
神经病学   1677篇
特种医学   1004篇
外科学   4418篇
综合类   118篇
预防医学   588篇
眼科学   342篇
药学   1632篇
中国医学   53篇
肿瘤学   3104篇
  2023年   186篇
  2022年   353篇
  2021年   639篇
  2020年   314篇
  2019年   497篇
  2018年   608篇
  2017年   471篇
  2016年   603篇
  2015年   637篇
  2014年   884篇
  2013年   989篇
  2012年   1595篇
  2011年   1771篇
  2010年   987篇
  2009年   845篇
  2008年   1459篇
  2007年   1636篇
  2006年   1629篇
  2005年   1631篇
  2004年   1572篇
  2003年   1506篇
  2002年   1495篇
  2001年   336篇
  2000年   246篇
  1999年   305篇
  1998年   346篇
  1997年   288篇
  1996年   265篇
  1995年   212篇
  1994年   195篇
  1993年   176篇
  1992年   170篇
  1991年   161篇
  1990年   138篇
  1989年   153篇
  1988年   117篇
  1987年   95篇
  1986年   112篇
  1985年   126篇
  1984年   78篇
  1983年   70篇
  1982年   54篇
  1981年   52篇
  1979年   50篇
  1978年   43篇
  1977年   33篇
  1975年   35篇
  1974年   34篇
  1973年   30篇
  1970年   29篇
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
51.
Palmar advancement flap with V-Y closure for thumb tip injuries   总被引:1,自引:0,他引:1  
The palmar advancement flap with V-Y closure was used in two patients with thumb tip injuries. This technique allows more distal advancement of the flap than does a conventional palmar advancement flap and does not require skin graft coverage.  相似文献   
52.
Primary extranodal malignant lymphoma frequently occurs in the gastrointestinal tract; however, it is rarely encountered in the rectum. We report herein the case of an 85-year-old man who underwent abdominoperineal resection for primary malignant lymphoma of the rectum, and 1 year later, developed hematemesis caused by gastric metastasis. To our knowledge this is the first case report of such distant metastasis developing from malignant lymphoma of the rectum.  相似文献   
53.
To investigate the responses of nasal vessels, divided into resistance and capacitance vessels, to a beta-receptor agonist in human, mucosal blood flow of the inferior turbinate and nasal airway resistance were measured when 1.5 mg terbutaline was applied topically. Mucosal blood flow was measured by the hydrogen clearance method just beneath the site where terbutaline in physiological saline (0.02 ml) was applied on an extremely localized area of the nasal mucosa. Nasal airway resistance of the ipsilateral and contralateral nasal cavities was measured separately by anterior rhinomanometry when terbutaline in normal saline (0.1 ml) was sprayed in the unilateral nasal cavity. Topical application of terbutaline elicited neither a significant increase of mucosal blood flow of the inferior turbinate nor an increase of nasal airway resistance. beta-Receptors seem not to be as densely distributed both in the resistance vessels and in the capacitance vessels as to cause vasodilatation by their activation in the nasal mucosa.  相似文献   
54.
Classification by position of dorsal root ganglia in the lumbosacral region   总被引:8,自引:0,他引:8  
M Hasue  J Kunogi  S Konno  S Kikuchi 《Spine》1989,14(11):1261-1264
In order to determine the incidence of the proximally placed L5 and S1 dorsal root ganglia, 144 patients with lumbosacral radiculopathy were investigated. All of the patients underwent nerve root infiltration for depicting the nerve root. Using some bony landmarks on the anteroposterior radiculogram, the dorsal root ganglia were classified into three types: intraspinal, intraforaminal, and extraforaminal. The intraspinal type was further subdivided into subarticular and sublaminar types. The intraspinal type is more common in the S1 than in the L5 root, regardless of age and sex. Although the proximally placed dorsal root ganglia may offer a locus minoris resistantiae for neural irritation and compression, its role for symptom production of radiculopathy should be further analyzed.  相似文献   
55.
A 36-year-old man was admitted to a hospital with complaints of fever, polyarthralgia and dyspnea. Erythema was observed on his face, extensor surface of the fingers and extremities, and a chest X-ray revealed massive bilateral pleural effusion. He had no sign of myopathy at this point. Pleural fluid was proved to be exudative and contained extremely high levels of hyaluronic acid. He was also complicated with interstitial pneumonitis and was given a pulse therapy with methyl prednisolone followed by daily administration of 55 mg prednisolone (PSL). Twenty days after the commencement of the therapy, pleural effusion decreased but muscle weakness gradually appeared, accompanied by elevation of myogenic enzymes. Myogenic changes on electromyogram, and irregularity of the muscle fibers with slight inflammatory cell infiltrates in a biopsy specimen were demonstrated. He was transferred to our hospital, and a diagnosis of dermatomyositis was made. Later, pleural effusion waxed and waned depending on the dosage of PSL, but no other causative disorder was demonstrated by extensive examinations. This case indicates that the pleuritis could be one of the vasculitic manifestations of dermatomyositis.  相似文献   
56.
Ethylnitrosourea (ENU) is a simple alkylating agent. It induces gene mutations in fetal primordial germ cells (PGCs), and a high incidence of congenital malformations is also found in the offspring of male mice treated with ENU at the embryonic stage. It is also reported that decreases in the fertility rate and weights of the testis and ovary were found in the offspring from dams treated with ENU. In this study, we analyzed the occurrence of apoptotic cell death and the expression of p53 protein which is thought to play an important role in the DNA damage-induced apoptosis after administration of ENU to pregnant rats on day 13 of gestation to obtain a clue for clarifying the toxic effect of ENU on PGCs. Apoptotic cells increased in PGCs in fetal gonads from 3 h after treatment. The number of apoptotic PGCs peaked at 6 h and gradually decreased towards 24 h after treatment. On the other hand, p53-positive PGCs increased from I h after treatment, prior to the induction of apoptosis. The number of p53-positive PGCs peaked at 3 h and returned to the control level at 24 h after treatment. These results suggest that ENU induces apoptosis in rat fetal PGCs immediately after its administration to dams and excess cell death by apoptosis may have a close relation to the later occurrence of decreases in the fertility rate and gonadal weight. Moreover, a possible involvement of p53 is suggested in the ENU-induced apoptosis in PGCs.  相似文献   
57.
To clarify the role of serotonin in cerebral ischemia, we examined the effects of selective serotonin reuptake inhibitors, citalopram and clomipramine, on ischemic neuronal damage in the gerbil. Pretreatment with citalopram (40 mg/kg i.p.) and clomipramine (20 mg/kg i.p.) protected against neuronal destruction of hippocampal CA1 pyramidal cells following 5 min of forebrain ischemia. Furthermore, microdialysis assays showed that a striking increase in extracellular excitatory amino acid levels during ischemia was significantly inhibited by pretreatment with citalopram and clomipramine. However, citalopram (40 mg/kg i.p.) did not alter the extracellular amino acid concentrations in normal gerbils. Thus, serotonin reuptake inhibitors have a protective effect against ischemic neuronal damage. Furthermore, the present result suggests that the protective effect is mediated through prevention of the accumulation of extracellular excitatory amino acids during and after ischemia.  相似文献   
58.
Forty-nine pathologically proven gallbladder lesions were evaluated in 45 patients using dynamic MRI with a spoiled gradient pulse sequence (SPGR), to access the ability of this technique to differentiate benign from malignant gallbladder lesions. The studies were reviewed retrospectively. Signal intensity of the lesions were measured. Twenty-one malignant and 28 benign lesions were classified into three categories: polypoid, diffuse wall thickening, and exophytic. Early and delayed enhancement patterns were evaluated. For the polypoid masses, malignant lesions (n = 9) demonstrated early and prolonged enhancements, whereas benign lesions (n = 14) had early enhancement with subsequent washout (P < .05). For diffuse gallbladder wall thickening, malignant lesions (n = 6) demonstrated early and prolonged enhancement and benign lesions (n = 14) showed relatively slow, prolonged enhancement (P < .05). The exophytic masses (n = 6) all were malignant and demonstrated early and prolonged enhancement. Dynamic MRI can help differentiate benign from malignant gallbladder lesions.  相似文献   
59.
60.
Five latissimus dorsi musculocutaneous flaps (LD flap) were used for reconstruction with prostheses after resection of tumors between 1984 and 1991 in our hospital. Bony structures were reconstructed with prostheses and in three cases autoclaved autobone grafts were also needed. The prostheses and adjacent grafts were then wrapped by the LD flaps. Tumor sites included one humerus, two thighs, and two knees. All but one case healed primarily. The sole case of infection was successfully treated with debridement and irrigation. Due to the LD flaps' plentiful blood supply, we believe infection of the prosthetics can be avoided and good clinical results can be achieved using the flap with autoclaved autograft prosthetic composite reconstruction. © 1994 Wiley-Liss, Inc.  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