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   24687篇
  免费   1003篇
  国内免费   131篇
耳鼻咽喉   153篇
儿科学   593篇
妇产科学   398篇
基础医学   3029篇
口腔科学   684篇
临床医学   1706篇
内科学   6247篇
皮肤病学   434篇
神经病学   2169篇
特种医学   784篇
外科学   3834篇
综合类   135篇
一般理论   1篇
预防医学   637篇
眼科学   353篇
药学   1777篇
  2篇
中国医学   27篇
肿瘤学   2858篇
  2024年   158篇
  2023年   175篇
  2022年   301篇
  2021年   520篇
  2020年   311篇
  2019年   399篇
  2018年   499篇
  2017年   334篇
  2016年   414篇
  2015年   473篇
  2014年   557篇
  2013年   688篇
  2012年   1034篇
  2011年   1157篇
  2010年   655篇
  2009年   538篇
  2008年   979篇
  2007年   1140篇
  2006年   1037篇
  2005年   1087篇
  2004年   1008篇
  2003年   944篇
  2002年   994篇
  2001年   949篇
  2000年   926篇
  1999年   866篇
  1998年   308篇
  1997年   235篇
  1996年   282篇
  1995年   168篇
  1994年   160篇
  1993年   149篇
  1992年   539篇
  1991年   497篇
  1990年   521篇
  1989年   462篇
  1988年   438篇
  1987年   439篇
  1986年   380篇
  1985年   397篇
  1984年   283篇
  1983年   194篇
  1979年   217篇
  1978年   144篇
  1977年   145篇
  1971年   138篇
  1970年   135篇
  1969年   133篇
  1968年   141篇
  1967年   141篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
To clarify the mechanism of the origin of adenomyosis, we investigated the immunohistochemical distribution of collagen type III in the human endometrium and the adenomyosis throughout the menstrual cycle. 1) Collagen type III was localized in the stroma of normal endometrium and ectopic endometrium, and in the myometrium. No staining of collagen type III was observed in the endometrial gland. 2) The intensity of staining for collagen type III in the basal layer of normal endometrium was stronger than those in the functional layer. The staining in the proliferative phase was stronger than that in the secretory phase. 3) The intensity of staining of collagen type III in ectopic endometrium paralleled that in the basal layer of normal endometrium. 4) The intensity of staining of collagen type III in the myometrium did not change throughout the menstrual cycle. These results suggest that close similarities exist between stromal cells in normal endometrium and in ectopic endometrium from the viewpoint of the extracellular matrix.  相似文献   
32.
We were able to produce two highly reproducible experimental models (in the rabbit) that demonstrated a high degree of reflex bladder contractile activity. In one model, a somatovesical reflex was induced by touching or pinching the perineal area. This reflex may be organized through a neurogenic reflex at the spinal level. In another model, rhythmic bladder contractions were produced by distal urethral constriction in the absence of bladder distension. These rhythmic contractions were thought to be due to a supraspinal reflex. In both types of contractile reflexes, intravenous administration of hexamethonium inhibited the reflex contractile activity virtually completely, intravenous atropine inhibited over 90% of the induced contractile activity, thus suggesting that these contractions were mediated reflexly through cholinergic stimulation. These two models of reflex bladder contractions should be useful for the study of hyperreflexic bladders.  相似文献   
33.
An accurate and reproducible colorimetric assay was established to determine the concentration of basic fibroblast growth factor (bFGF) or bFGF-like activity in culture media and biological fluids. Fetal bovine heart endothelial cell line ATCC CRL 1395 was used as the bFGF-dependent cell line. The proliferation-stimulating activity of bFGF was determined by measuring the amount of formazan formed by the mitochondrial enzymes from a tetrazolium salt, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), instead of counting the viable cell numbers or measuring the incorporation of [3H]-thymidine. The addition of 250 ng/mL of heparin to the culture medium resulted in about a tenfold increase in the proliferation-stimulating activity of bFGF and allowed the detection of as low as 10 pg/mL of bFGF. Heparin also resulted in much smaller inter- and intraassay variations. The bFGF concentrations determined by this colorimetric assay correlated well with those determined by both the [3H]-thymidine incorporation assay using BALB/c 3T3 fibroblast cells (r = 0.998) and the cell number count assay (r = 0.996). This assay can be adapted to quantify bFGF or bFGF-like activity in tissue culture media and biological fluids such as plasma and organ extracts.  相似文献   
34.
35.
Optical technological innovations enable us to visualize cellular nuclei endoscopically. Herein is described a protocol design for a multicenter study for the ex vivo evaluation of endocytoscopy. The present study was performed by the Endoscopy Forum Japan study group.  相似文献   
36.
A case of quadricuspid aortic valve with aortic regurgitation   总被引:2,自引:0,他引:2  
A 67-year-old man with grade 3 aortic valve regurgitation was found to have a quadricuspid aortic valve. The aortic valve consisted of 1 large, 2 intermediate and 1 small sized cusp. An accessory cusp located between the right and noncoronary cusps, and shaped like a hammock which sling by the fibrous strings originating from the both commissures to the aortic wall. Aortic valve replacement was successfully performed with a 23 mm St. Jude Medical prosthetic valve, and the patient is asymptomatic five months post-operatively. Histological examination of the resected cusps showed fibrous thickening and no rheumatic valvulitis or infective endocarditis.  相似文献   
37.
Previously, we demonstrated that the inductive properties of bone morphogenetic protein (BMP) highly depend on the nature of the carrier material used for implantation. In this paper, we show that administration of BMP incorporated in a fibrous collagen membrane can help to regenerate periodontal ligament and cementum both in cat canines and in monkey molars. The partially purified bovine BMP was combined with one or two layers of a fibrous collagen membrane. Although the single layer approach showed partial regeneration of periodontal defects, it also quite often led to ankylosis. The double layer technique in artificially prepared class III furcation defects in monkey molars gave favorable results. After 12 wk, not only the alveolar process but also the periodontal ligament and cementum had regenerated along the entire treated dentin surface. Collagen fibers were arranged more or less perpendicular to the surface of the new cementum. Ankylosis was not seen. It is concluded that the double-layer approach is superior to the single-layer technique in regenerating cementum.  相似文献   
38.
In a patient who had undergone construction of a continent ileal pouch we successfully repaired an incontinent ileal tube by infolding it in an imbricated portion of the ileal pouch wall. For 2 years postoperatively the patient has been urine continent and has catheterized the pouch easily. We believe this infolding technique is useful for reconstructing the continent mechanism in patients with incompetent ileal valves.  相似文献   
39.
A 33-year-old man with a 6-month history of rhinitis and bronchial asthma was referred to our hospital with polyarthralgia, severe anemia, hypoxemia, mononeuropathy multiplex, and renal insufficiency with hematuria. Marked eosinophilia was observed in his sputum, peripheral blood, and bronchoalveolar lavage fluid (BALF). In addition, his sputum contained many hemosiderin-laden macrophages, indicative of pulmonary hemorrhage. His chest roentgenogram on admission showed diffuse ground grass appearance. High resolution computed tomography (HRCT) demonstrated diffuse high density areas throughout the lung fields and characteristic irregularity and enlargement of the peripheral pulmonary arteries. His general condition rapidly deteriorated, but dramatically improved with oral steroid administration, and his major symptoms disappeared within a few days. Examination of the biopsied lung tissue revealed unequivocal evidence of pulmonary angitis with marked eosinophilic infiltration and perivascular granulomas. Bone marrow biopsy showed hyperplasia of eosinophilic leukocytes in contrast to the low cellularity. Suppression of erythroid hemopoiesis was thought to be the primary cause for his rapidly progressive anemia. Serum anti-GBM antibody titer returned to within the normal range soon after the initiation of steroid therapy.  相似文献   
40.
Case 1: A 48-year-old male with stage 4 penile cancer is reported. We used peplomycin (PEP) and cisplatinum (CDDP) for preoperative chemotherapy. Chemotherapy was effective. Radical surgery with bilateral inguinal lymphadenectomy was done and skin defect was covered with a skin flap. Case 2: A 61-year-old male with stage 4 penile cancer underwent radical surgery after modified MBD therapy with methotrexate (MTX), PEP and CDDP. Emasculation with skin resection and inguinal and pelvic lymphadenectomy were performed. The skin defect was deep and wide. It was covered with a glacilis myocutaneous skin flap. Distal end of the flap became necrotic. It was covered with tensor fascia lata myocutaneous flap. Seventeen patients with penile cancer were treated between 1972 and 1990 at Mie University Hospital. Nine patients were in stage 1, 4 stage 2, 1 stage 3, 3 stage 4. Treatment consisted of surgery (3), surgery+chemotherapy (10), surgery+chemotherapy+irradiation (2), chemotherapy+irradiation (1), and surgery+irradiation(1). Cancer death was observed in 2 cases (stage 2), 2 patients died of other diseases, 10 are alive, and 3 patients were lost to follow up.  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