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   1528篇
  免费   103篇
  国内免费   6篇
耳鼻咽喉   11篇
儿科学   36篇
妇产科学   28篇
基础医学   201篇
口腔科学   34篇
临床医学   114篇
内科学   331篇
皮肤病学   119篇
神经病学   93篇
特种医学   86篇
外科学   133篇
综合类   12篇
预防医学   91篇
眼科学   23篇
药学   72篇
中国医学   2篇
肿瘤学   251篇
  2023年   15篇
  2022年   35篇
  2021年   74篇
  2020年   39篇
  2019年   48篇
  2018年   62篇
  2017年   41篇
  2016年   49篇
  2015年   42篇
  2014年   68篇
  2013年   68篇
  2012年   109篇
  2011年   113篇
  2010年   49篇
  2009年   38篇
  2008年   89篇
  2007年   92篇
  2006年   81篇
  2005年   57篇
  2004年   54篇
  2003年   44篇
  2002年   31篇
  2001年   26篇
  2000年   32篇
  1999年   32篇
  1998年   8篇
  1997年   4篇
  1996年   10篇
  1995年   6篇
  1994年   7篇
  1993年   6篇
  1992年   21篇
  1991年   15篇
  1990年   23篇
  1989年   25篇
  1988年   24篇
  1987年   9篇
  1986年   8篇
  1985年   14篇
  1984年   12篇
  1983年   5篇
  1981年   3篇
  1979年   5篇
  1978年   3篇
  1975年   7篇
  1974年   3篇
  1971年   3篇
  1970年   4篇
  1969年   6篇
  1967年   6篇
排序方式: 共有1637条查询结果,搜索用时 15 毫秒
1.
2.
3.
Post-thoracotomy wound pain in 11 patients who underwent thoracic operation was controlled by intercostal nerve block with alcohol and thoracic epidural anesthesia. The intercostal nerve block was performed just before the closure of the thoracotomy wound. Epidural anesthesia was employed from the 1st to 5th post operative day. This method alleviated post-thoracotomy pain and obviated postoperative pulmonary complication in all patients in early post operative periods. In late post operative periods after discharge, intercostal nerve block could maintain excellent analgesia in 9 of 11 patients, only 2 patients required analgesic drugs or re-block of the intercostal nerve. Thus, intercostal nerve block with alcohol is an effective and simple option to control recalcitrant post-thoracotomy wound pain in thoracic surgery.  相似文献   
4.
5.
We have previously reported that KU-2285, a 2-nitroimidazole with a fluorinated N1-substituent (-CH2-CF2CONH(CH2)nOH, n = 2), was a promising hypoxic cell radiosensitizer. In this study the pharmacokinetics of KU-2285 and its related compounds (n = 3 and n = 4) were compared with those of etanidazole (a 2-nitroimidazole with an N1-substituent of -CH2CONH(CH2)nOH, n = 2) and its related compounds (n = 3 and n = 4) to assess the effects of incorporation of a CF2 group. The lipophilicity of the fluorinated compounds was higher than that of etanidazole, as measured by the octanol/water partition coefficient. As the number of CH2 groups increased, the lipophilicity of the compounds in both the KU-2285 and etanidazole series increased. The brain tissue levels of the fluorinated compounds were as low as those of the etanidazole derivatives, while the biological half-lives of the fluorinated compounds in peripheral nervous tissues were shorter than those of related non-fluorinated compounds.  相似文献   
6.
BACKGROUND CONTEXT: There is no report in the literature of two-level disc herniation in the cervical and thoracic spine presenting with spastic paresis/paralysis exclusively in the bilateral lower extremities. PURPOSE: To identify the clinical characteristics of specific myelopathy resulting from C6-C7 disc herniation through a case with spastic paresis in the lower extremities without upper extremities symptoms due to separate disc herniation in the cervical and thoracic spine, which was surgically removed in two stages. STUDY DESIGN/SETTING: A case report. METHODS: A 48-year-old man developed a gait disturbance as well as weakness and numbness in the lower extremities. Thoracic magnetic resonance imaging (MRI) showed a T11-T12 disc herniation, which was removed under the surgical microscope through a minimally invasive posterior approach. He improved, but 2 months after surgery developed recurrent numbness and spasticity. On this occasion, no evidence of recurrence of the thoracic disc herniation could be identified, but cervical MRI demonstrated a compressed spinal cord at the C6-C7 level. The patient had no neurological findings in the upper extremities. The herniated disc at C6-C7 was removed under the surgical microscope with laminoplasty. RESULTS: The symptoms gradually improved after surgery. At the present time, 2 years and 9 months after the initial operation, the patient had a stable gait and was able to work. CONCLUSIONS: Our experience suggests that in the diagnosis of patients with spastic paresis and sensory disturbances in the lower extremities, spinal cord compression should be explored by imaging studies not only in the thoracic spine but also in the cervical spine, especially at the C6-C7 level, even if the symptoms and abnormal neurological findings are absent in the upper extremities.  相似文献   
7.
The criteria for clinical evaluation of the efficacy of antimicrobial agents on prostatitis were proposed. Nomenclatural definition, specifications of patients and criteria were as follows. Acute prostatitis: Target infection is acute bacterial prostatitis with no underlying condition in urinary tract. The findings of swelling and tenderness of prostate by rectal examination are essential. The patients are between 16 and 69 years old. They have fever greater than 37 degrees C and pain on micturition. Microscopic examination reveals white blood cells (WBCs) in VB1 or VB2 before treatment greater than or equal to 10 cells/hpf. Viable bacteria in VB1 or VB2 before treatment are greater than or equal to 10(4) bacteria/ml. Period of treatment is for 7 days. To evaluate clinical efficacy, 3 days after administration, changes of symptoms (fever and pain on micturition) are recorded. Seven days after administration, changes of symptoms, microscopic examinations and number of bacteria are recorded. The overall clinical efficacy is graded as "excellent", "moderate" or "poor" by combining changes in the above 3 parameters. Chronic prostatitis: Target infection is chronic bacterial prostatitis with no underlying condition in urinary tract. The patients are between 16 and 69 years old. Microscopic examination reveals WBC in EPS or VB3 before treatment greater than or equal to 10 cells/hpf. Viable bacteria before treatment are greater than or equal to 10(3)/ml (GNR) or greater than or equal to 10(4)/ml (GPC). Treatment period is for 14 days. To evaluate clinical efficacy, after 14 days of administration, changes of symptoms, microscopic examinations and number of bacteria are recorded. The overall clinical efficacy is graded as "excellent", "moderate", or "poor" by combining the changes in the 2 parameters, microscopic examination and number of bacteria.  相似文献   
8.
The purpose of this study was to compare the MR characteristics of renal cell carcinomas against histologic findings and to assess the correlations among signal intensity, tumor enhancement, and pathologic findings. Fifty-four patients (56 lesions) were examined by MR imaging and then underwent partial or radical nephrectomy. The pathologic diagnosis of all lesions was renal cell carcinoma. All MR examinations were performed as dynamic studies using the same 1.5-T scanner. MR characteristics were compared against pathologic findings after resection, and the correlations among signal intensity, tumor enhancement, and pathologic findings were then assessed. A significant correlation was observed between tumor grade and tumor enhancement, with G3 lesions tending to show little enhancement. Regardless of the histologic classification, G3 tumors were found to contain highly heterotypic cancer cells and very few vessels by histopathologic examination. No significant correlations were noted between the other MR characteristics and pathologic findings. Renal cell carcinomas showing little enhancement tend to be highly malignant lesions based on the pathologic findings. Special consideration is required for these tumors with regard to the selection of surgical intervention and follow-up observation.  相似文献   
9.
Chemical shift MRI is widely used for identifying adenomas, but it is not a perfect method. We determined whether combined dynamic MRI methods can lead to improved diagnostic accuracy. Fifty-seven adrenal masses were examined by chemical shift and dynamic MR imaging using 2 MR systems. The masses included 38 adenomas and 19 non-adenomas. In chemical shift MRI studies, the signal intensity index (SI) was calculated, and the lesions classified into 5 types in the dynamic MRI studies. Of the 38 adenomas studied, 37 had an SI greater than 0. In the dynamic MRI, 34 of 38 adenomas showed a benign pattern (type 1). If the SI for the adenomas in the chemical shift MRI was considered to be greater than 0, the positive predictive value was 0.9, and the negative predictive value was 0.94 and kappa = 0.79. If type 1 was considered to indicate adenomas in the dynamic MRI, the corresponding values were 0.94, 0.81 and kappa = 0.77 respectively. The results obtained when the 2 methods were combined were 1, 0.95 and kappa = 0.96 respectively. The chemical shift MRI was found to be useful for identifying adenomas in most cases. If the adrenal mass had a low SI (0 < SI < 5), dynamic MRI was also found to be helpful for making a differential diagnosis.  相似文献   
10.
To investigate the mechanism of the long-lasting efficacy of chimeric monoclonal anti-TNF antibody (cA2) therapy for rheumatoid arthritis (RA), eight patients with refractory RA were treated with a single infusion of cA2 and the changes in circulating cytokines (IL-1, IL-6, TNF, and IL-10), soluble cytokine receptors (TNF-RI, RII, and sIL-6R) and peripheral white blood cell (WBC) subset counts were followed up long-term (12 weeks) after cA2 therapy in them. Significant clinical responses (>20% improvement according to Paulus' criteria) were observed just after cA2 infusion and lasted more than 4 weeks in all patients, as reported elsewhere. Moreover, five of the eight patients showed prolonged clinical responses (>12 weeks). The elevated serum IL-6 and sTNF-RI (or RII) levels before treatment rapidly decreased after treatment. The serum IL-10 levels also significantly elevated before treatment. The elevations of serum IL-10 levels were augmented after treatment and stayed higher than the baseline in four patients with prolonged clinical responses. No significant TNF, IL-1 and -, or sIL-6R were detected in the sera of the patients before treatment and during the whole study period. On the other hand, peripheral lymphocytes as well as total WBC and neutrophils increased for 4 weeks after treatment. However, thereafter, only the lymphocyte count decreased gradually and stayed below the baseline long-term (12 weeks). FACS analysis revealed the predominance of T lymphocytes in the decrease in lymphocyte counts. These results suggest that the augmentation of IL-10 production and the decrease in T cells might partly contribute to the long-lasting efficacy of cA2 treatment in RA.  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