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   423篇
  免费   8篇
儿科学   60篇
基础医学   25篇
口腔科学   8篇
临床医学   59篇
内科学   102篇
皮肤病学   8篇
神经病学   31篇
外科学   74篇
综合类   2篇
预防医学   1篇
药学   30篇
肿瘤学   31篇
  2016年   3篇
  2015年   7篇
  2014年   2篇
  2013年   10篇
  2012年   7篇
  2011年   3篇
  2010年   13篇
  2009年   9篇
  2008年   3篇
  2007年   6篇
  2006年   34篇
  2005年   14篇
  2004年   13篇
  2003年   14篇
  2002年   8篇
  2001年   7篇
  2000年   3篇
  1999年   10篇
  1998年   33篇
  1997年   29篇
  1996年   36篇
  1995年   42篇
  1994年   23篇
  1993年   12篇
  1992年   13篇
  1991年   8篇
  1990年   2篇
  1989年   5篇
  1988年   4篇
  1986年   6篇
  1985年   5篇
  1984年   4篇
  1983年   2篇
  1982年   5篇
  1981年   6篇
  1980年   5篇
  1979年   3篇
  1975年   1篇
  1973年   1篇
  1972年   1篇
  1969年   1篇
  1968年   2篇
  1967年   1篇
  1962年   1篇
  1961年   1篇
  1960年   1篇
  1957年   1篇
  1956年   1篇
  1955年   3篇
  1954年   3篇
排序方式: 共有431条查询结果,搜索用时 15 毫秒
61.
PURPOSE: The incidence of prostate cancer, benign prostatic enlargement and serum level of prostate-specific antigen (PSA) increase with patient age. Intermediate elevation of PSA in elderly populations is apt to be considered insignificant. We evaluated the impact of PSA and prostate volume on the presence of non-palpable prostate cancer in elderly men with an intermediate level of PSA. MATERIALS AND METHODS: Clinical records of 154 men 70 years or older, with non-cancerous digital rectal examination findings and with serum PSA levels of 2.0-10.0 ng/mL, who underwent initial 6- to 10-core transrectal prostate biopsy, were reviewed for prostate volume, number of biopsy cores, PSA and associated parameters. Stepwise logistic regression and receiver operating characteristic (ROC) models were used to determine the impacts of the parameters on the biopsy results. RESULTS: Overall cancer detection rate was 40/154 or 26.0%. Prostate-specific antigen showed no significant association with the presence of prostate cancer (P = 0.59, Mann-Whitney U-test), while prostate volume did (P < 0.0001). On stepwise logistic regression analysis, prostate volume (P = 0.024, 95% CI 1.008-1.116) and biopsy core density (P = 0.017, 95% CI 4.76-7.12 x 10(6)) were independently associated with a cancer diagnosis, whereas PSA density was not an independent factor for a positive biopsy result. The area under the ROC curve for prostate volume was significantly superior to that of PSA (0.802 vs. 0.529; P = 0.012). CONCLUSIONS: In men 70 years or older with gray zone PSA, prostate cancer patients are equally distributed over any PSA range. Although PSA has less impact on cancer presence than mere prostate volume, prostate cancer would be detected in a substantial proportion of older patients with PSA levels of 2.0-10.0 ng/mL.  相似文献   
62.
Time-course of plasma concentration of unchanged drug of the dopamine DA1-receptor agonist (–)-(S)-4-(3,4-dihydroxyphenyl)-7,8-dihydroxy-1,2,3,4-tetrahydroisoquinoline hydrochloride hydrate (YM435), and its effects on blood pressure and renal blood flow were investigated in anaesthetized dogs. Continuous intravenous infusion of YM435 (0.1–3 μg kg? min?) rapidly increased renal blood flow and lowered blood pressure in a dose-dependent manner. These effects remained generally stable throughout the infusion period. Following the start of infusion, plasma concentration of unchanged drug also rose rapidly and dose-dependently and remained virtually constant throughout the infusion period. A significant correlation was observed between log YM435 plasma concentration and the increase in renal blood flow (r = 0.93, P < 0.0001) and between the former and the reduction in blood pressure (r = 0.93, p < 0.0001). The present results indicate that YM435 produces renal vasodilatation and lowering of blood pressure in a dose-dependent manner and with rapid onset following continuous intravenous infusion, and that these effects are generally stable throughout the period of infusion. These haemodynamic effects of YM435 were in good agreement with the time-course of plasma concentration of unchanged drug.  相似文献   
63.
Antibody to p40tax (anti-p40tax) in serum specimens obtained sequentially from a human T cell lymphotropic virus type I carrier population of mothers and children were assayed. The prevalences of anti-p40tax at the initial sampling were 88% (7/8) in children and 55% (16/29) in mothers. Two of the seven positive children lost their anti-p40tax during the investigation period, resulting in a final prevalence of 63% (5/8) in children. However, anti-p40tax status was constant in all the 22 mothers with multiple serum samples (15 remained positive and seven remained negative). A decline in the absorbance value of EIA for anti-p40tax was observed in seven of the 15 anti-p40tax positive mothers. This decline may result in the disappearance of anti-p40tax in some of them.  相似文献   
64.
A 70‐year‐old man was admitted to Ueno Municipal Hospital, Ueno, Japan, for evaluation of abdominal distension. Computed tomography showed a 1 × 1 cm cyst at the pancreas tail. Endoscopic retrograde pancreatography (ERP) showed a normal pancreatic duct after the first gentle injection and an enhanced cyst at the pancreas tail. Extravasation of the contrast medium occurred from the pancreatic duct to the superior‐dorsal extrapancreas at the same time of the next low‐pressure manual injection. Computed tomography showed extravasation of the contrast medium from the pancreas cyst to the retroperitoneal space after ERP. It was considered that the cyst wall weakness, in addition to slight elevated pancreatic duct pressure, caused the disruption of the cyst wall.  相似文献   
65.
BACKGROUND: We retrospectively analysed the outcomes of conservative management of Peyronie's disease and determined the factors predicting successful outcome. METHODS: The study involved 31 patients with Peyronie's disease who were treated at our institute between 1985 and 2003. We assessed the efficacy of vitamin E for the improvement of the symptoms, and the factors which contributed to successful outcome with conservative management using multivariate analysis. RESULTS: There was no statistically significant difference in the relief rate between the vitamin E and no-medication groups. The overall estimated relief rate was 67.5% at 2 years from presentation. The multivariate analysis revealed plaque size to be the only significant factor predicting the relief from all symptoms in patients with conservative management. The rate was 100% in patients having a plaque size of 20 mm or smaller and 20.0% in those having a size of larger than 20 mm (P=0.005). CONCLUSIONS: We could not confirm the benefit of vitamin E for Peyronie's disease. Plaque size was the only significant factor predicting the relief from all symptoms. Patients with larger plaque might fail to respond to the conservative management.  相似文献   
66.
A case of a 53-year-old male with development of myosarcomaat the site of thorotrast injection is described. Thorotrastwas injected 29 years ago for the preoperative angiographicexamination of brain injury when there was an accidental extravasationof the contrast medium. Recently, a firm tumor was detected in the left side of theneck but without causing any disturbance to swallowing or breathing.Biopsy examination revealed myosarcoma with deposition of thorotrastin the surrounding tissue. Roentgenographic examination of theabdomen also showed deposition of thorotrast in the spleen andupper abdominal lymph nodes.  相似文献   
67.
Although the prime importance in treatment of head and neckcancer is eradication of tumors, due attention should be paidto the conservation of many important structures and functionsin the region. Just to mention a few of these important humanfunctions, there are phonation, digestion and facial expression.Simple surgical procedures specialized by otolaryngologistsare no longer satisfactory. Recently, radiotherapy of head and neck cancer has developedto a superlative degree and chemotherapy to a practical degreealthough much still remains to be satisfied. Our aim was toorganize an interdisciplinary group of specialists in surgery,radiotherapy and regional chemotherapy into a composite attackforce. We aimed at most effective treatment with the least ofside effects. Since 1961, our combined approach to cancer of the head andneck in close collaboration with radiotherapists has yieldedmuch improved results. This has led to an increasing numberof patients with satisfactory rehabilitation.
  1. 1. Cancer of the maxilla: Even in the advanced cases combinedsurgery, radiotherapy and regional chemotherapy has led to thepreservation of important structures and functions. Many patientsare now allowed to return to social life and to their previousjobs.
  2. 2. Cancer of the nasopharynx: Radiotherapy is the firstchoice.When the effect is less satisfactory, chemotherapy anda window-operationof the palate are performed.
  3. 3. Tumorsof the tonsils: The majority of patients suffer fromthe reticulumcell sarcoma. Radiotherapy is the first choice.
  4. 4. Cancerof the larynx: A full dose of radiotherapy is thefirst choice.Partial resections are done when indicated.
  5. 5. Cancer of thetongue, hypopharynx and esophagus: Radiotherapyis the firstchoice in the majority of cases. Some need plasticsurgery.
  相似文献   
68.
Autologous marrow was collected from patients with acute leukemiaduring their first remission, and cryopreserved. In relapse,four of the patients were treated with remission-induction chemotherapymore intensive than the previous treatment, followed by infusionof the cryopreserved autologous marrow. Autologous marrow infusioncaused relatively rapid hematological recovery from the bonemarrow depression induced by high-dose chemotherapy. All fourpatients achieved a second complete remission, but with no maintenancetherapy leukemic relapses were observed in three of them. Onepatient survived without leukemic relapse for 19 months, 13months longer than the previous remission period. Another effectof autoinfusion was reduction in blood products required duringthe bone marrow depression. These observations suggest thatcryopreserved autologous marrow may retain its hemopoietic activityand autologous marrow infusion may be effective in providingearly recovery or rescue from bone marrow failure.  相似文献   
69.
Gene therapy is defined as the treatment of diseases by the transfer of genes into patients. Clinical trials of gene therapy became feasible as a result of the development of retroviral mediated gene transfer techniques. The first trial was begun in September 1990 at the National Institutes of Health when a four year old girl was treated for adenosine deaminase deficiency. Currently, more than 500 patients are being treated by this innovative therapeutic strategy. In the present review article, the basic concepts and present status of human gene therapy are summarized.  相似文献   
70.
Stem bromelain was cleaved with cyanogen bromide, and the products were fractionated with and without prior maleylation and sulfitolysis. The fragments that corresponded to the carboxyl-terminal half of the molecule were isolated and nearly completely sequenced. This portion of the enzyme molecule contained one disulfide linkage. A specific cleavage at the amino peptide bonds of that cystine residue by reduction, modification into S-cyano derivatives and exposure to alkali gave important information of the amino terminal sequence. By combining the present data with the previously known partial sequence of the parent molecule, 101 amino acid residues were aligned down to the carboxyl terminus and compared with those of papain. The sequence homology between carboxyl-terminal halves of these two thiol proteases of plant origin was found to be 34.7%.  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