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   646篇
  免费   33篇
  国内免费   23篇
耳鼻咽喉   2篇
儿科学   36篇
妇产科学   1篇
基础医学   37篇
口腔科学   10篇
临床医学   42篇
内科学   142篇
皮肤病学   8篇
神经病学   5篇
特种医学   121篇
外科学   42篇
综合类   30篇
预防医学   10篇
眼科学   27篇
药学   38篇
肿瘤学   151篇
  2023年   1篇
  2022年   1篇
  2021年   2篇
  2020年   3篇
  2019年   4篇
  2018年   8篇
  2017年   3篇
  2016年   8篇
  2015年   12篇
  2014年   11篇
  2013年   15篇
  2012年   13篇
  2011年   13篇
  2010年   12篇
  2009年   15篇
  2008年   25篇
  2007年   31篇
  2006年   27篇
  2005年   15篇
  2004年   20篇
  2003年   11篇
  2002年   13篇
  2001年   21篇
  2000年   14篇
  1999年   20篇
  1998年   34篇
  1997年   22篇
  1996年   26篇
  1995年   24篇
  1994年   21篇
  1993年   22篇
  1992年   22篇
  1991年   11篇
  1990年   24篇
  1989年   12篇
  1988年   14篇
  1987年   12篇
  1986年   20篇
  1985年   25篇
  1984年   15篇
  1983年   12篇
  1982年   11篇
  1981年   14篇
  1980年   13篇
  1979年   9篇
  1978年   6篇
  1977年   7篇
  1976年   6篇
  1975年   2篇
排序方式: 共有702条查询结果,搜索用时 0 毫秒
41.

Background

Phaconit or ultra micro incision phacoemulsification cataract surgery involves phacoemulsification through a 0.9 millimetre sleeveless phaco tip and irrigating chopper followed by implantation of a rollable intraocular lens. The procedure leads to negligible astigmatism and faster visual recovery as compared to phacoemulsification with a foldable intraocular lens.

Methods

This prospective study analysed 80 cases of sub millimetre phaconit surgery with implantation of rollable intraocular lenses(IOL) in 40 cases and acrylic foldable IOL in the remaining 40 cases. Evaluation of efficacy and adaptability of procedure, equipment settings, operative constraints, postoperative complications, keratometric and topographic evaluation of induced astigmatism with visual outcome and patient''s rehabilitation were studied.

Results

The intraoperative complications were surge/ chamber collapse in 16 (20%), iris chaffing in one and corneal burns in two cases. All cases had an induced astigmatism of less than or equal to ± 0.25 D in four to six weeks after rollable IOL and ± 0.5 D to ± 0.75 D after acrylic IOL implantation. All patients had best-corrected visual acuity of 6/6 by third post operative day.

Conclusion

Phaconit with rollable IOL is a perfect blend of surgical skill, application of technology and ultra thin IOL.Key Words: Phaconit, Ultra micro phaco, Submillimetre incision, Rollable IOL implantation  相似文献   
42.
Breast infection and breast sepsis secondary to Pseudomonas aeruginosa is uncommon. We report two cases of pseudomonal breast infection leading to septic shock and abscess formation in women with non-responding breast infection. The management of breast infection is broad-spectrum antibiotics and ultrasound with aspiration of any collection. To treat breast infection effectively, the causative organism must be isolated to enable appropriate antibiotic therapy.  相似文献   
43.
Tumor vascular signals in renal masses: detection with Doppler US   总被引:3,自引:0,他引:3  
Ramos  IM; Taylor  KJ; Kier  R; Burns  PN; Snower  DP; Carter  D 《Radiology》1988,168(3):633-637
The vascularity of 49 renal masses (26 malignant and 23 benign lesions) was investigated with duplex Doppler ultrasound. Doppler signals obtained at the margins of renal masses were defined as "tumor signals" when the Doppler-shifted frequency of the lesion exceeded the frequency shift in the ipsilateral main renal artery. These exceeded 2.5 kHz with a 3-MHz insonating frequency. Among the 26 renal masses that subsequently proved to be malignant, tumor signals were obtained in 15 of 18 (83%) untreated renal cell carcinomas, in three of four Wilms tumors, and in two patients with metastases to the kidney, but not in the one patient with lymphoma. None of the 23 benign renal masses demonstrated tumor signals. Tumor vascularity in malignant lesions gives rise to abnormal, high-velocity, Doppler-shifted signals that can help in the differential diagnosis of renal masses.  相似文献   
44.
45.

Objectives

The aims of this study were (1) to compare the accuracy of the detection of approximal enamel caries lesions using three intraoral storage phosphor plate digital systems and one conventional film-based radiographic system; and (2) to determine whether there is a correlation between the histological and radiographic measurements of enamel caries.

Methods

160 approximal surfaces were radiographed under standardized conditions using three storage phosphor stimulable systems (DenOptix and Digora FMX with white and blue plates), and one film system (Insight film). 17 observers scored the images for the presence and depth of caries using a 4-point scale. The presence of caries was validated histologically (gold standard). Two-way analysis of variance was used to test the differences in sensitivity, specificity and overall accuracy (TP + TN). The data from the radiographic and histological measurements were statistically analysed by Spearman’s rank correlation coefficient.

Results

Two-way analysis of variance and the post hoc t-test demonstrated that Digora (white plate) had higher specificity and overall accuracy values than DenOptix (P = 0.021); there was no statistically significant difference among the other imaging modalities (P > 0.05). There was no significant correlation between the histological depth measurements and the radiographic measurements from Digora (blue plate) (P = 0.43), Digora (white plate) (P = 0.15), DenOptix (P = 0.17) and Insight film (P = 0.06).

Conclusions

The results suggest that (1) the performance of the three storage phosphor image plate systems was similar to that of the Insight film for detection of approximal enamel caries, and (2) the increase in histological depth of enamel caries was not significantly correlated with radiographic measurements.  相似文献   
46.
The optics of eccentric photo refraction are analysed. The variation of photo refractive lunula area with refractive error, pupil size, flash eccentricity and camera aperture were calculated using a model eye. Measurements from photographs of paraxial (eccentric) photo refraction of model eyes show that a good agreement exists between theory and experiment over a range of refractive errors from — 10 D to +10 D. Calculations were also made for a standard reduced eye. The optimal set-up for measuring refractive error accurately over a wide range of refractive states is discussed, as are the problems which arise from non-central fixation.  相似文献   
47.
Phase II trial of mitomycin in malignant mesothelioma   总被引:1,自引:0,他引:1  
  相似文献   
48.
We investigated the bronchodilator dose-response to nebulized albuterol and the dose of albuterol which produces maximal bronchodilation in the acutely ill, hospitalized asthmatic. Consecutively admitted patients from the emergency room in status asthmaticus who fulfilled the inclusion criteria (age <41 years old and <12 pack-years of smoking) were studied. Albuterol was administered by nebulizer (Puritan-Bennett Raindrop) in repeated 2.5-mg treatments up to a total dose of 10 mg and the bronchodilator response was measured by a computerized spirometer. Twenty-two patients were studied. Baseline spirometry showed a (mean +/- SE) forced expiratory volume in 1 sec (FEV1) of 1.26 +/- 0.14 L (42 +/- 4.0% predicted), which increased significantly (p < 0.05) during albuterol titration to a maximum FEV1 of 1.70 +/- 0.19 L (57 +/- 5% of predicted). After cumulative doses of 2.5, 5.0, 7.5, and 10.0 mg of nebulized albuterol, 27%, 45%, 72%, and 77% of patients, respectively, attained maximum bronchodilation. The remaining 23% of patients did not respond to doses up to 10 mg of albuterol. The maximum FEV1 response to albuterol did not correlate with the initial severity of airflow obstruction (r = 0.36, p > 0.05). Pulse rate and arterial oxygen saturation were not significantly affected by nebulized albuterol up to a total dose of 10 mg. No arrhythmias were noted. In summary, most hospitalized asthmatics (72%) required a cumulative dose of 7.5 mg of nebulized albuterol to achieve maximum bronchodilation and a large fraction (50%) required higher albuterol doses than the standard 2.5 mg. The bronchodilatory response to nebulized albuterol varied widely among patients in status asthmaticus and could not be predicted from the initial severity of airflow obstruction. Because side effects were minimal, it would be reasonable to use 7.5 mg of nebulized albuterol as initial therapy. Alternatively, dose-response titration with albuterol would be advantageous.  相似文献   
49.
50.
To determine the frequency and prognostic importance of pretreatment clinical characteristics in patients currently undergoing treatment for stage III non-small-cell lung cancer (NSCLC), data were collected on 378 patients receiving high-dose (120 mg/m2) cisplatin plus vinca alkaloid combination chemotherapy regimens since 1978. Variables analyzed included age, sex, weight loss, performance status, histologic subtype, presence of extrathoracic metastases, number of metastatic organ sites, presence of liver, bone, or brain involvement, prior radiation or surgery, and serum lactate dehydrogenase (LDH). The effect of a major response to chemotherapy on survival was also investigated. Using multivariable analyses, the following were found to be associated with outcome: initial performance status, with patients having a performance status of 80% to 100% having an increased major objective response rate and survival; bone metastases, which were adversely predictive of response rate and survival; elevated serum LDH and male sex, both of which were associated with shortened survival and remission duration; and the presence of two or more extrathoracic metastatic organ sites, which was associated with shorter survival. When major objective response with chemotherapy was included in a conditional multivariable analysis, it was strongly associated with longer median survival. Information from this analysis may be useful when comparing the response data of completed studies in similar patients, in designing future trials, and in the selection of cisplatin plus vinca alkaloid therapy for individual patients with advanced NSCLC.  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