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   7476篇
  免费   314篇
  国内免费   33篇
耳鼻咽喉   77篇
儿科学   158篇
妇产科学   132篇
基础医学   951篇
口腔科学   176篇
临床医学   477篇
内科学   1868篇
皮肤病学   153篇
神经病学   927篇
特种医学   201篇
外科学   1126篇
综合类   23篇
预防医学   191篇
眼科学   180篇
药学   419篇
中国医学   10篇
肿瘤学   754篇
  2022年   50篇
  2021年   127篇
  2020年   80篇
  2019年   116篇
  2018年   144篇
  2017年   98篇
  2016年   99篇
  2015年   123篇
  2014年   184篇
  2013年   223篇
  2012年   341篇
  2011年   353篇
  2010年   205篇
  2009年   160篇
  2008年   291篇
  2007年   341篇
  2006年   298篇
  2005年   351篇
  2004年   287篇
  2003年   317篇
  2002年   289篇
  2001年   216篇
  2000年   252篇
  1999年   197篇
  1998年   82篇
  1997年   69篇
  1996年   55篇
  1995年   71篇
  1994年   71篇
  1993年   49篇
  1992年   179篇
  1991年   175篇
  1990年   153篇
  1989年   174篇
  1988年   153篇
  1987年   127篇
  1986年   117篇
  1985年   131篇
  1984年   104篇
  1983年   87篇
  1979年   79篇
  1978年   53篇
  1977年   57篇
  1976年   49篇
  1974年   51篇
  1973年   58篇
  1972年   53篇
  1970年   55篇
  1969年   56篇
  1968年   45篇
排序方式: 共有7823条查询结果,搜索用时 78 毫秒
111.
S M Chou  Y Mizuno 《Muscle & nerve》1986,9(5):455-464
The term "cytoplasmic body" or "spheroid body" myopathy refers to a heterogeneous group of familial or sporadic diseases characterized primarily by the presence of abundant spheroid or cytoplasmic bodies in the muscles. The morphogenesis of these inclusions remains unclear. This article describes the induction and evolution of spheroid cytoplasmic bodies (SCBs) in the rat plantaris muscle (PL) with local tetanus, which was induced in rats by the injection of a minute amount of tetanus toxin. In contrast to the tetanized soleus muscle (SOL), which developed core fibers (central cores, minicore, target fiber, targetoid fiber, and rods), the tetanized PL produced numerous SCBs with a predictable time course. They were induced in both type 1 and 2 fibers of PL, which is composed predominantly (95%) of type 2 fibers, in contrast to SOL (85% type 1 fibers). Factors inducing SCBs may include immobilization, shortening, intact innervation, and disuse atrophy.  相似文献   
112.
The purpose of this study was to examine how gold kiwifruit pericarp (pericarp is defined as the skin of the fruit) consumption and the timing thereof affect the postprandial blood glucose profile. The study was conducted on twelve healthy volunteers (six men and six women). According to our results, the simultaneous intake of gold kiwifruit with bread and the prior intake of gold kiwifruit evidently suppressed the postprandial blood glucose elevation compared with exclusive bread intake. There was no significant difference in postprandial blood glucose changes between the ingestion of gold kiwifruit pericarp and pulp and that of gold kiwifruit pulp only. The highest postprandial blood glucose elevation was suppressed by 27.6% and the area under the blood glucose elevation curve by 29.3%, even with the exclusive ingestion of gold kiwifruit pulp. We predicted that the ingestion of both the pericarp and pulp of gold kiwifruit would reduce the postprandial blood glucose elevation to a greater extent than that of gold kiwifruit pulp only; however, there was no significant difference between the two. These results indicate that gold kiwifruit consumption significantly suppresses the postprandial blood glucose elevation regardless of pericarp presence or absence and the timing of ingestion.  相似文献   
113.
Purpose

Intravesical bacillus Calmette–Guérin (BCG) is the standard of care for bladder carcinoma in situ (CIS). The response to BCG therapy against CIS is generally assessed by random bladder biopsy (RBB). In this study, we examined the necessity of routine RBB after BCG therapy.

Methods

We retrospectively identified 102 patients who were initially diagnosed with CIS with or without papillary tumor and received subsequent 6–8-week BCG therapy. Thereafter, all patients underwent voiding cytology analysis, cystoscopy, and RBB to evaluate the effects of BCG therapy. We evaluated the association between clinical parameters (voiding cytology and cystoscopy findings) and the final pathological results by RBB specimens.

Results

According to the pathological results of RBB, 30 (29%) patients had BCG-unresponsive disease (remaining urothelial carcinoma was confirmed pathologically) and 20 were diagnosed with CIS. Positive/suspicious voiding cytology and positive cystoscopy findings were well observed in patients who had BCG-unresponsive disease compared with their counterparts (p?=?0.116, and p?<?0.001, respectively). The sensitivity (Sen.), specificity (Spe.), positive predictive value (PPV), and negative predictive value (NPV) of voiding cytology were 50%, 68%, 39%, and 77%, respectively. The values for cystoscopy findings were as follows: Sen.: 87%, Spe.: 57%, PPV: 46%, and NPV: 91%. The values for their combination (having either of them) were as follows: Sen.: 100%, Spe.: 44%, PPV: 43%, and NPV: 100%.

Conclusion

RBB after BCG therapy for patients with negative voiding cytology and negative cystoscopy may be omitted because their risk of BCG-unresponsive disease is significantly low (NPV: 100%).

  相似文献   
114.
115.
116.
BackgroundMany factors have been reported to affect postoperative range of knee flexion after total knee arthroplasty (TKA); however, no study has reported the impact of preoperative range of motion of the hip to the postoperative flexion angle of the knee thus far.MethodsOf 38 consecutive patients who underwent posterior-stabilized TKA, we assessed 21 patients after excluding 17 patients who met exclusion criteria. The range of motion of the knee and the hip, age, body-mass index, serum albumin level, HbA1c, Kellgren–Lawrence grade, knee extension strength and radiological femorotibial angle as well as postoperative knee flexion angle at three months were evaluated. The preoperative data and the knee flexion angle at three months after TKA were compared using Spearman''s rank correlation coefficient.ResultsKnee flexion angle at three months after TKA was positively correlated with preoperative flexion (ρ = 0.616, p = 0.007) and external rotation angle (ρ = 0.576, p = 0.012) of the hip as well as preoperative knee flexion angle (ρ = 0.797, p = 0.001). There were no correlations between postoperative knee flexion angle and other preoperative data.ConclusionsPatients with restricted flexion and/or external rotation of the hip may have contractures of Gluteus maximus, Gluteus medius and Tensor fasciae latae, which can cause hypertension of iliotibial tract. It may cause decreased internal rotation of the tibia when the knee is flexed, which affects postoperative knee flexion angle, thus limited flexion and/or external rotation of the hip might restrict knee flexion angle following TKA.  相似文献   
117.
Retinoblastomas exhibit a unique form of differentiation to produce cell elements similar to those seen in a photoreceptor cell. An ultrastructural study was performed on 29 cases of retinoblastoma to further clarify the cytologic characteristics of the tumor cells. The age of the retinoblastomas averaged 17.1 months and the tumor cells showing photo-receptor differentiation were demonstrated in 10 cases (35%). The findings were especially notable in retinoblastomas with Flexner-Wintersteiner rosette formation (seven cases, 28%). Similar photoreceptor differentiation was also evident in solid cell clusters without rosette formation (four cases, 14%). The presence of photoreceptor elements was assumed to be significantly frequent both in Flexner-Wintersteiner rosettes and in the solid cell clusters. The cell cytoplasm also showed proliferation of long mitochondria and microtubules, reflecting photoreceptor differentiation. The hereditary-type retinoblastoma showed more advanced cell differentiation than the non-hereditary type. Photoreceptor differentiated retinoblastoma showed rather indolent growth compared with the undifferentiated type, and the former can expect a curative treatment by operation. These observations provide additional findings of the biological nature of retinoblastomas.  相似文献   
118.
Isolated avulsion fractures of the lesser tuberosity are extremely rare. A 24-year-old woman fell on her back as her arm was forcibly extended and adducted. Radiographs revealed a small fragment of bone beneath the glenoid. Axillary radiography showed the bone fragment and a bone defect of the lesser tuberosity. Computed tomography scan clearly demonstrated those findings. Surgery was performed 3 weeks after the occurrence of the injury. The bone fragment was reduced and fixed by means of two screws. After 3 weeks, light exercise was started. At follow-up 7 months later she had no complaints. Most reported cases involved sudden contraction of the subscapularis tendon. This type of fracture is sometimes misdiagnosed; computed tomography scan is useful for diagnosis. Previously reported cases have similarly demonstrated a good outcome after surgery, except in cases involving children.  相似文献   
119.
Numerous clinical classification systems have been developed for patients with ruptured intracranial aneurysms. However, most systems do not take age into account and are less reliable in elderly than in younger patients in terms of indications for early surgery and predicting the clinical outcome. The authors have studied this problem using our clinical classification system and, present here the results of 38 elderly patients (greater than or equal to 65 years of age) who underwent neck clipping and implementation of continuous ventricular drainage within 3 days of aneurysm rupture. The clinical outcome at 1 year after onset was considered "good" if the patient was able to function independently and "poor" if he or she was partially or fully dependent or had died. The preoperative level of consciousness was not significantly correlated with the outcome according to Spearman's nonparametric statistical analysis. Age, however, was a significant factor: the incidence of poor outcome was significantly higher in patients over age of 70 years than in those between 65 and 70 (p less than 0.05). Postoperative complications, which were previously found to be significantly related to the outcome in elderly patients, were significantly more common in patients who had a history of cardiac, pulmonary, hepatic, and/or renal disease than in those without such a history (p less than 0.005). The authors found that the prognostic accuracy of clinical classification systems, based on preoperative level of consciousness, is improved in geriatric cases if one point is added for patients over age of 70 years or those with a history of systemic diseases. Additional relevant factors included computed tomographic findings and pre-existing cerebral dysfunction.  相似文献   
120.
Summary Monoclonal antibody (MCA) G-22 is directed against a human glioma-associated surface antigen. Its availability for the radioimmunodetection of human glioma was analyzed by utilizing the xenografts in athymic mice. Nude mice with subcutaneous grafts of U251-MG or U251-SP glioma received intravenous administration of 123I or 131I labeled F(ab)2 fragment or whole immunoglobulin. Results of radioimaging revealed that 123I-labeled antibody was better than the 131I-labeled. It was also noted that administration of 123I-labeled F(ab)2 fragment of G-22 MCA enabled the imaging of human glioma xenografts weighing 80–650 mg after 48 hours. When biodistribution of 123I MCA was compared between G-22 and control antibodies, the percentages of dose/g in tumors were 5.228–1.799 at 30 hours and 4.112–1.132 at 48 hours with G-22 and they were 4.164–1.248 and 0.314–0.142 with control. The tumor/blood ratio until 72 hours after injection was constantly above 1 with G-22 and less than 1 with control antibody. These results indicate the potential usefulness of G-22 MCA for the radioimmunodetection of human gliomas.  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