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   522篇
  免费   34篇
  国内免费   6篇
耳鼻咽喉   3篇
儿科学   9篇
基础医学   55篇
口腔科学   8篇
临床医学   27篇
内科学   64篇
皮肤病学   2篇
神经病学   14篇
特种医学   235篇
外科学   40篇
综合类   7篇
预防医学   24篇
眼科学   3篇
药学   19篇
肿瘤学   52篇
  2023年   1篇
  2022年   4篇
  2021年   4篇
  2020年   3篇
  2019年   9篇
  2018年   12篇
  2017年   3篇
  2016年   6篇
  2015年   10篇
  2014年   11篇
  2013年   13篇
  2012年   20篇
  2011年   20篇
  2010年   9篇
  2009年   9篇
  2008年   18篇
  2007年   15篇
  2006年   12篇
  2005年   7篇
  2004年   10篇
  2002年   2篇
  2001年   5篇
  2000年   4篇
  1999年   5篇
  1998年   20篇
  1997年   21篇
  1996年   15篇
  1995年   13篇
  1994年   21篇
  1993年   17篇
  1992年   4篇
  1991年   2篇
  1990年   9篇
  1989年   24篇
  1988年   22篇
  1987年   26篇
  1986年   17篇
  1985年   21篇
  1984年   22篇
  1983年   14篇
  1982年   14篇
  1981年   19篇
  1980年   15篇
  1979年   4篇
  1978年   11篇
  1977年   6篇
  1976年   7篇
  1975年   5篇
  1974年   1篇
排序方式: 共有562条查询结果,搜索用时 15 毫秒
181.

OBJECTIVE:

Fenitrothion residue is found primarily in soil, water and food products and can lead to a variety of toxic effects on the immune, hepatobiliary and hematological systems. However, the effects of fenitrothion on the male reproductive system remain unclear. This study aimed to evaluate the effects of fenitrothion on the sperm and testes of male Sprague-Dawley rats.

METHODS:

A 20 mg/kg dose of fenitrothion was administered orally by gavages for 28 consecutive days. Blood sample was obtained by cardiac puncture and dissection of the testes and cauda epididymis was performed to obtain sperm. The effects of fenitrothion on the body and organ weight, biochemical and oxidative stress, sperm characteristics, histology and ultrastructural changes in the testes were evaluated.

RESULTS:

Fenitrothion significantly decreased the body weight gain and weight of the epididymis compared with the control group. Fenitrothion also decreased plasma cholinesterase activity compared with the control group. Fenitrothion altered the sperm characteristics, such as sperm concentration, sperm viability and normal sperm morphology, compared with the control group. Oxidative stress markers, such as malondialdehyde, protein carbonyl, total glutathione and glutathione S-transferase, were significantly increased and superoxide dismutase activity was significantly decreased in the fenitrothion-treated group compared with the control group. The histopathological and ultrastructural examination of the testes of the fenitrothion-treated group revealed alterations corresponding with the biochemical changes compared with the control group.

CONCLUSION:

A 20 mg/kg dose of fenitrothion caused deleterious effects on the sperm and testes of Sprague-Dawley rats.  相似文献   
182.
The value of adjuvant radiotherapy in triple‐negative breast cancer (TNBC) is currently debated. We assessed the association between adjuvant radiotherapy and survival in a large cohort of Asian women with TNBC. Women diagnosed with TNBC from 2006 to 2011 in five Asian centers (N = 1,138) were included. Survival between patients receiving mastectomy only, breast‐conserving therapy (BCT, lumpectomy and adjuvant radiotherapy) and mastectomy with radiotherapy were compared, and adjusted for demography, tumor characteristics and chemotherapy types. Median age at diagnosis was 53 years (range: 23–96 years). Median tumor size at diagnosis was 2.5 cm and most patients had lymph node‐negative disease. The majority of patients received adjuvant chemotherapy (n = 861, 76%) comprising predominantly anthracycline‐based regimes. In 775 women with T1‐2, N0‐1, M0 TNBCs, 5‐year relative survival ratio (RSR) was highest in patients undergoing mastectomy only (94.7%, 95% CI: 88.8–98.8%), followed by BCT (90.8%, 95% CI: 85.0–94.7%), and mastectomy with radiotherapy (82.3%, 95% CI: 73.4–88.1%). The adjusted risks of mortality between the three groups were not significantly different. In 363 patients with T3‐4, N2‐3, M0 TNBCs, BCT was associated with highest 5‐year RSR (94.1%, 95% CI: 81.3–99.4%), followed by mastectomy with radiotherapy (62.7%, 95% CI: 54.3–70.1%), and mastectomy only (58.6%, 95% CI: 43.5–71.6%). Following multivariable adjustment, BCT and mastectomy with radiotherapy remained significantly associated with lower mortality risk compared to mastectomy only. Overall, adjuvant radiotherapy was associated with higher survival in women aged <40 years, but not in older women. Adjuvant radiotherapy appears to be independently associated with a survival gain in locally advanced as well as in very young TNBC.  相似文献   
183.
184.
Normal trachea during forced expiration: dynamic CT measurements   总被引:5,自引:0,他引:5  
Stern  EJ; Graham  CM; Webb  WR; Gamsu  G 《Radiology》1993,187(1):27
  相似文献   
185.
186.
Three-dimensional US of the fetus. Work in progress   总被引:5,自引:0,他引:5  
  相似文献   
187.
Carpal avascular necrosis: MR imaging   总被引:1,自引:0,他引:1  
The authors evaluated the use of magnetic resonance (MR) imaging in diagnosis of avascular necrosis (AVN) of carpal bones by examining 21 patients with wrist pain and two healthy volunteers. MR images were compared with conventional radiographs in every case and with bone scintigrams in 18 cases. MR imaging was slightly less sensitive than bone scintigraphy in depicting AVN, but in patients who were imaged with long repetition time (TR)/long echo time (TE) sequences in addition to short TR/short TE sequences, MR imaging was found to be more specific. While the authors believe that bone scintigraphy remains the screening test of choice for patients with wrist pain and normal plain radiographs, MR imaging promises to add significant diagnostic information in cases in which bone scans are abnormal.  相似文献   
188.
Unusual artifact with mammography film   总被引:2,自引:0,他引:2  
  相似文献   
189.
190.
柱切换HPLC法测定血浆和尿中卡托普利浓度   总被引:2,自引:0,他引:2  
田维荣  高申  王世祥 《药学学报》1992,27(8):613-617
卡托普利先经衍生化形成具有紫外吸收的衍生物,然后用6%的高氯酸去蛋白,取上清液直接进样。以μBoundapak C18(37~50μm)作为预处理柱(5cm×O.5cm,ID),对样品进行自动浓缩净化处理,预处理流动相为0.2%醋酸溶液。分析柱(15cm×O.5cm,ID)固定相为YWG-C13,10μm,流动相为乙晴-水-醋酸(35:65:0.4)。UV 260nm检测。血浆和尿样测定的线性范围分别为20~1000ng/ml和10~200μg/ml,血浆中最低检测浓度约为10ng/ml。方法的平均回收率分别为103.2%(血浆)和99.5%(尿样),日内及日间变异均小于10%。  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