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   920篇
  免费   106篇
  国内免费   7篇
耳鼻咽喉   7篇
儿科学   62篇
妇产科学   9篇
基础医学   68篇
口腔科学   34篇
临床医学   104篇
内科学   203篇
皮肤病学   23篇
神经病学   41篇
特种医学   166篇
外科学   93篇
综合类   81篇
预防医学   31篇
眼科学   3篇
药学   72篇
  1篇
肿瘤学   35篇
  2021年   9篇
  2020年   9篇
  2019年   10篇
  2018年   19篇
  2017年   12篇
  2016年   18篇
  2015年   21篇
  2014年   24篇
  2013年   24篇
  2012年   16篇
  2011年   13篇
  2010年   27篇
  2009年   34篇
  2008年   21篇
  2007年   20篇
  2006年   37篇
  2005年   14篇
  2004年   25篇
  2003年   24篇
  2002年   17篇
  2001年   21篇
  2000年   16篇
  1999年   13篇
  1998年   31篇
  1997年   59篇
  1996年   47篇
  1995年   35篇
  1994年   41篇
  1993年   40篇
  1992年   24篇
  1991年   11篇
  1990年   19篇
  1989年   19篇
  1988年   24篇
  1987年   15篇
  1986年   7篇
  1985年   12篇
  1984年   15篇
  1983年   22篇
  1982年   21篇
  1981年   14篇
  1980年   14篇
  1979年   17篇
  1978年   12篇
  1977年   9篇
  1976年   18篇
  1975年   17篇
  1974年   9篇
  1973年   11篇
  1966年   4篇
排序方式: 共有1033条查询结果,搜索用时 15 毫秒
1.
2.
We report the results of administration of danazol after suspension of gonadotrophin-releasing hormone analogue (GnRHa) therapy for uterine myomas. A total of 21 women with uterine myomas was treated with 100 mg danazol for 6 months after GnRHa therapy. Uterine volume and endocrine status were monitored monthly by ultrasound and assay of plasma gonadotrophins, oestradiol and progesterone. The results show a rebound of uterine volume about 30% less than in controls at the end of danazol therapy. Menstrual cyclicity returned after 65 +/- 3 days in 16 subjects and five patients remained amenorrhoeic. Hormone assays confirmed renewed ovarian function in the women whose menstrual periods returned. Bone mineral content was substantially reduced during GnRHa treatment but improved significantly during danazol therapy even in the women who remained amenorrhoeic. These results show the utility of danazol in prolonging the therapeutic effects of GnRHa. The mechanism by which danazol inhibits rebound of uterine volume may be due to its antiprogesterone effects on uterine myomas.   相似文献   
3.
Study Objective . To determine the influence of treatment on the microbiologic outcome of funguria. Design . Retrospective case series. Setting . A 300-bed tertiary care teaching hospital in a large metropolitan area. Subjects . 141 hospitalized patients, 18 years of age or older, with at least one urine culture positive (≥ 102 cfu/ml) for fungi. Interventions . Retrospective review of medical records to determine the microbiologic outcome of funguria. Main Results . Funguria developed rapidly in individuals with known predisposing factors. Urinalysis did not routinely detect the presence of fungi or pyuria. Symptoms such as fever, dysuria, and frequency were generally absent. Funguria persisted whether it was due to Candida albicans or non-albicans species. There were no statistical differences in the microbiologic outcomes of treated and untreated funguria. Conclusions . Funguria is a rapidly developing, often benign and persistent process. Minimizing predisposing risks, such as removing indwelling urinary catheters, is beneficial in its management. Pharmacologic treatment of funguria due to C. albicans or non-albicans species does not influence the microbiologic outcome.  相似文献   
4.
5.
We report a patient with unilateral damage to the rostral part of the pulvinar who was impaired in localizing stimuli in the inferior visual field contralateral to the lesion and who made errors in the binding of shape and color in that quadrant. The findings demonstrate the importance of the pulvinar in spatial coding and provide support for the function of the thalamus in binding of features. They also provide evidence for a homology between the visual field maps of the inferior and lateral subdivisions of the pulvinar in monkeys and in humans, such that the inferior visual field is represented in the rostral part of the nucleus.  相似文献   
6.
7.
Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm).  相似文献   
8.
The authors report the clinical and laboratory findings of a patient who had severe immune hemolytic anemia due to hydrochlorothiazide (HCTZ). In this case, the HCTZ antibody reacted not only with other thiazide and thiazide-like drugs, but also with a chemically unrelated diuretic, ethacrynic acid. These results indicate that HCTZ antibody activity is not restricted solely to the thiazides and imply that therapy with any of the reactive drugs would be contraindicated for this patient. The serologic screening for drug reactivity may be useful for selecting alternative therapy for patients with drug-induced immune hemolytic anemia.  相似文献   
9.
The incidence of emergent resistance and clinical factors affecting its development were evaluated by retrospective review of 173 studies encompassing over 14,000 patients. Eight antibiotic classes and 225 individual treatment regimens were evaluated. Emergent resistance occurred among 4.0% of all organisms and 5.6% of all infections treated. It appeared to be significantly more frequent with penicillin and aminoglycoside monotherapy, with significantly lower rates associated with imipenem-cilastatin, aztreonam, and combination therapy. Clinical failure also appeared to be significantly more likely to occur after emergence of resistance among organisms treated with fluoroquinolones or aminoglycosides. Infections associated with higher resistance rates were cystic fibrosis, osteomyelitis, and lower respiratory tract infections. Resistance was most common in patients in intensive care units or receiving mechanical ventilation. It was also significantly frequent among studies performed in university or teaching hospitals. Organisms associated with high resistance rates were Pseudomonas aeruginosa, Serratia, Enterobacter, and Acinetobacter sp. Factors such as infection type, underlying diseases, type of institution, and specific pathogens warrant consideration when examining emergent resistance.  相似文献   
10.
Fiala  ES; Sohn  OS; Li  H; El-Bayoumy  K; Sodum  RS 《Carcinogenesis》1997,18(9):1809-1815
We observed that pretreatment of male F344 rats with benzyl selenocyanate, a versatile organoselenium chemopreventive agent in several animal model systems, decreases the levels of DNA and RNA modifications produced in the liver by the hepatocarcinogen 2- nitropropane. To clarify the mechanisms involved, we pretreated male F344 rats with either benzyl selenocyanate, its sulfur analog benzyl thiocyanate, phenobarbital or cobalt protoporphyrin IX; the latter is a depletor of P450. We then determined (1) the ability of liver microsomes to denitrify 2-nitropropane, (2) effects on 2-nitropropane- induced liver DNA and RNA modifications and (3) amount of nitrate excreted in rat urine following administration of the carcinogen. Pretreatment with benzyl selenocyanate or phenobarbital increased the denitrification activity of liver microsomes by 217 and 765%, respectively, increased liver P4502B1 by 31- and 435-fold, respectively, decreased the levels of 2-nitropropane-induced modifications in liver DNA (29-70% and 17-30%, respectively) and RNA (67-85% and 30-50%, respectively), and increased the 24-h urinary excretion of nitrate by 157 and 209%, respectively. Pretreatment with benzyl thiocyanate had no significant effect on any of these parameters. Pretreatment with cobalt protoporphyrin IX decreased liver P4502B 1 by 87%, decreased the denitrification activity of liver microsomes by 76%, decreased the 24 h urinary excretion of nitrate by 88.5%, but increased the extent of 2-nitropropane-induced liver nucleic acid modifications by 17-67%. These results indicate that the metabolic sequence from 2-nitropropane to the reactive species causing DNA and RNA modifications does not involve the removal of the nitro group. Moreover, they suggest that benzyl selenocyanate inhibits 2-NP-induced liver nucleic acid modifications in part by increasing its detoxication through induction of denitrification, although it is evident that other mechanisms must also be involved.   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