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   132篇
  免费   5篇
  国内免费   7篇
儿科学   8篇
妇产科学   4篇
基础医学   16篇
口腔科学   1篇
临床医学   33篇
内科学   22篇
皮肤病学   7篇
神经病学   7篇
特种医学   18篇
外科学   4篇
综合类   3篇
预防医学   3篇
眼科学   1篇
药学   11篇
肿瘤学   6篇
  2021年   1篇
  2018年   3篇
  2017年   1篇
  2016年   1篇
  2015年   4篇
  2014年   2篇
  2013年   4篇
  2012年   1篇
  2011年   3篇
  2010年   5篇
  2009年   10篇
  2008年   13篇
  2007年   7篇
  2006年   1篇
  2005年   3篇
  2003年   2篇
  2002年   1篇
  2001年   3篇
  2000年   2篇
  1999年   2篇
  1998年   7篇
  1997年   10篇
  1996年   5篇
  1995年   4篇
  1994年   3篇
  1993年   6篇
  1992年   3篇
  1990年   4篇
  1989年   2篇
  1988年   7篇
  1987年   5篇
  1985年   3篇
  1984年   2篇
  1983年   1篇
  1981年   1篇
  1978年   2篇
  1977年   1篇
  1975年   5篇
  1974年   2篇
  1973年   1篇
  1941年   1篇
排序方式: 共有144条查询结果,搜索用时 0 毫秒
31.
The choice of a contrast agent for pulmonary angiography has important implications for patient comfort, image quality, and perhaps the safety of the procedure, particularly for "high-risk" patients. In a prospective study the nonionic, low-osmolality agent iopamidol eliminated the problem of image degradation due to coughing, and patients showed excellent tolerance for it. However, pressure measurements obtained within 3-5 minutes of injection of iopamidol and diatrizoate sodium meglumine 76% showed no significant difference in the hemodynamic effects of the two contrast agents, either for normotensive or for pulmonary hypertensive patients. Contrary to a common presumption, pulmonary hypertension by itself did not appear to increase the risk of pulmonary angiography. The theoretic presumption of greater hemodynamic stability with low-osmolality contrast agents was not clinically evident in this trial with iopamidol. At present, enhanced patient comfort and improved image quality remain the only confirmed bases for choosing this contrast agent for pulmonary angiography.  相似文献   
32.

Introduction

Reoperative parathyroidectomy is required when there is persistent or recurrent hyperparathyroidism following the initial surgery (at least 5% of parathyroidectomies nationally). By convention, ‘persistent disease’ is defined as the situation where the patient has not been cured by the first operation. The term ‘recurrent hyperparathyroidism’ is used when the patient was confirmed to be biochemically cured for six months from the first operation but has hyperparathyroidism after this date. Reoperative surgery is associated with higher rates of postoperative complications as well as a greater rate of failure to cure. The aim of our study was to review our departmental experience of reoperative parathyroidectomy, with a view to identify patterns of disease persistence and recurrence.

Methods

Using a departmental database, patients were identified who had undergone reoperative parathyroidectomy between 2006 and 2014. All the pre, intra and postoperative information was documented including the operative note so as to record the location of the abnormal parathyroid gland found at reoperation.

Results

Almost two-thirds (63%) of patients had negative, equivocal or discordant conventional imaging so secondary investigative tools were required frequently. The majority of abnormal glands were found in eutopic locations. The most common locations for ectopic glands were intrathyroidal, mediastinal and intrathymic. A third (33%) of the patients had multigland disease and over a quarter (28%) had coexisting thyroid disease.

Conclusions

Persistent hyperparathyroidism represents a challenging patient subgroup for which access to all radiological modalities and intraoperative parathyroid hormone monitoring are required. Patient selection for reintervention is a key determinant in the reoperation cure rate.  相似文献   
33.
Oritavancin is a recently approved lipoglycopeptide antimicrobial agent with activity against Gram-positive pathogens. Its extended serum elimination half-life and concentration-dependent killing enable single-dose treatment of acute bacterial skin and skin structure infections. At the time of regulatory approval, new agents, including oritavancin, are not offered in the most widely used susceptibility testing devices and therefore may require application of surrogate testing using a related antimicrobial to infer susceptibility. To evaluate vancomycin as a predictive susceptibility marker for oritavancin, 26,993 recent Gram-positive organisms from U.S. and European hospitals were tested using reference MIC methods. Organisms included Staphylococcus aureus, coagulase-negative staphylococci (CoNS), beta-hemolytic streptococci (BHS), viridans group streptococci (VGS), and enterococci (ENT). These five major pathogen groups were analyzed by comparing results with FDA-approved susceptible breakpoints for both drugs, as well as those suggested by epidemiological cutoff values and supported by pharmacokinetic/pharmacodynamic analyses. Vancomycin susceptibility was highly accurate (98.1 to 100.0%) as a surrogate for oritavancin susceptibility among the indicated pathogen species. Furthermore, direct MIC comparisons showed high oritavancin potencies, with vancomycin/oritavancin MIC90 results of 1/0.06, 2/0.06, 0.5/0.12,1/0.06, and >16/0.06 μg/ml for S. aureus, CoNS, BHS, VGS, and ENT, respectively. In conclusion, vancomycin demonstrated acceptable accuracy as a surrogate marker for predicting oritavancin susceptibility when tested against the indicated pathogens. In contrast, 93.3% of vancomycin-nonsusceptible enterococci had oritavancin MIC values of ≤0.12 μg/ml, indicating a poor predictive value of vancomycin for oritavancin resistance against these organisms. Until commercial oritavancin susceptibility testing devices are readily available, isolates that when tested show vancomycin susceptibility can be inferred to be susceptible to oritavancin by using FDA-approved breakpoints.  相似文献   
34.
The current nursing shortage, now referred to as a 'global crisis', is having a widespread impact on health systems around the world. In view of the international nursing shortage, the retention and matriculation of nursing students who gain entry to nursing programs is a vital facet of nursing education that has broad ramifications. Although enrollment in higher institutions in the United States has increased in the last two decades; graduation rates have not increased at the same rate. Yet the impact of pregnancy on the progression and matriculation of what remains a female dominated nursing student population in her child bearing years has not been adequately addressed. This exploratory study used grounded theory methodology to identify and describe the decision-making processes and coping of African American nursing students who become pregnant. Five interrelated themes emerged from the data. Participants reported inconsistent use of contraceptives but experienced discovery of the pregnancy as highly traumatic. Participants also described the decision to keep the pregnancy as conflict-ridden and difficult as a result of family values and religious beliefs and ultimately driven by maternal support. Maternal and faculty support was central to successful coping and matriculation while in nursing school. With the changing profile of the nursing student, it is important for educational institutions to become more pregnancy friendly in their endeavors to retain and matriculate nursing students.  相似文献   
35.
36.
Mutagenesis by the human bladder carcinogen 4-aminobiphenyl (ABP) was studied in single-stranded DNA from a bacteriophage M13 cloning vector. In comparison to ABP lesions in double-stranded DNA, lesions in single- stranded DNA were approximately 70-fold more mutagenic and 50-fold more genotoxic. Sequencing analysis of ABP-induced mutations in the lacZ gene revealed exclusively base-pair substitutions, with over 80% of the mutations occurring at G sites; the G at position 6310 accounted for 25% of the observed mutations. Among the sequence changes at G sites, G- ->T transversions predominated, followed by G-->C transversions and G-- >A transitions. In order to further elucidate the mutagenic mechanism of ABP, an oligonucleotide containing the major DNA adduct, N- (deoxyguanosin-8-yl)-4-aminobiphenyl (dG(8-ABP)), was situated within the PstI site of a single-stranded M13 genome. After in vivo replication of the adduct containing ABP-modified and control (unadducted) genomes, the mutational frequency and mutational specificity of the dG(8-ABP) lesion were determined. The targeted mutational efficiency was approximately 0.01%, and the primary mutation observed was the G-->C transversion. Thus dG(8-ABP), albeit weakly mutagenic at the PstI site, can contribute to the mutational spectrum of ABP lesions.   相似文献   
37.
38.
39.
首次测定确立高催乳血症必需避免过度的静脉穿刺压力,理想的情况是醒后或饭后致少1h来测试.  相似文献   
40.
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