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   701篇
  免费   52篇
  国内免费   2篇
耳鼻咽喉   2篇
儿科学   128篇
妇产科学   57篇
基础医学   111篇
口腔科学   14篇
临床医学   51篇
内科学   100篇
皮肤病学   16篇
神经病学   10篇
特种医学   74篇
外科学   48篇
综合类   9篇
预防医学   19篇
眼科学   57篇
药学   22篇
肿瘤学   37篇
  2022年   2篇
  2021年   3篇
  2020年   6篇
  2019年   10篇
  2018年   14篇
  2017年   12篇
  2016年   13篇
  2015年   28篇
  2014年   42篇
  2013年   25篇
  2012年   37篇
  2011年   25篇
  2010年   19篇
  2009年   32篇
  2008年   29篇
  2007年   39篇
  2006年   51篇
  2005年   35篇
  2004年   24篇
  2003年   18篇
  2002年   24篇
  2001年   29篇
  2000年   16篇
  1999年   7篇
  1998年   22篇
  1997年   40篇
  1996年   30篇
  1995年   15篇
  1994年   25篇
  1993年   14篇
  1992年   8篇
  1991年   8篇
  1990年   4篇
  1989年   9篇
  1988年   6篇
  1987年   3篇
  1986年   3篇
  1985年   5篇
  1984年   2篇
  1983年   4篇
  1982年   3篇
  1981年   3篇
  1980年   6篇
  1976年   5篇
排序方式: 共有755条查询结果,搜索用时 46 毫秒
1.
2.
3.
Benign intracranial hypertension (BIH) is reported in three children from Australia and one from New Zealand, who were being treated with recombinant human growth hormone (rhGH). Three males and one female, aged between 10.5 and 14.2 y, developed intracranial hypertension within 2 weeks to 3 months of starting treatment. A national database, OZGROW, has been prospectively collecting data on all 3332 children treated with rhGH in Australia and New Zealand from January 1986 to 1996. The incidence of BIH in children treated with growth hormone (GH) is small, 1.2 per 1000 cases overall, but appears to be greater with biochemical GHD (<10IUml -1), i.e. 6.5/1000 (3 in 465 cases), relative risk 18.4, 95% confidence interval 1.9-176.1, than in all other children on the database. The incidence in patients with Turner's syndrome was 2.3/1000 (1 in 428 cases). No cases in patients with partial GHD (10–20 IUml -1) or chronic renal failure were identified. Possible causative mechanisms are discussed. The authors'practice is now to start GH replacement at less than the usual recommended dose of 14IUm-2 week-1 in those children considered to be at high risk of developing BIH. Ophthalmological evaluation is recommended for children before and during the first few months following commencement of rhGH therapy and is mandatory in the event of peripheral or facial oedema, persistent headaches, vomiting or visual symptoms. The absence of papilledema does not exclude the diagnosis.  相似文献   
4.
AIM OF THE STUDY: The umbilical polyp is a rare congenital lesion resulting from the persistence of omphalomesenteric duct (OMD) enteric mucosa at the umbilicus. Exploration of the abdomen to exclude the presence of associated OMD remnants is controversial. The aim of this study was to evaluate the need for peritoneal cavity exploration in children with umbilical polyp. METHODS: All umbilical lesions (n = 53) excised between 1995 and 2005 in a single institution were reviewed to identify patients with umbilical polyp (n = 13). This is characterised histologically by the presence of gastrointestinal mucosa. A follow-up study of patients with umbilical polyp was performed. Data are reported as median (range). RESULTS AND CONCLUSIONS: All 13 patients underwent excision of an umbilical polyp at a median age of 15.1 months (3.1 - 80.5). All presented with a discharging polyp (associated with bleeding in 9) which did not respond to topical silver nitrate. Median diameter of the lesions was 0.5 cm (0.2 - 1). Histology revealed the presence of small bowel mucosa in 11 (associated with pancreatic tissue in 1 and gastric mucosa in 1) and large bowel mucosa in 2. All patients underwent inspection and probing of the base of the polyp after its excision. In 6 patients an associated OMD anomaly was suspected and exploration of the peritoneal cavity was performed (mini-laparotomy in 5 and laparoscopy in 1). No OMD anomaly was found. The 7 children who did not undergo exploration of the abdominal cavity remain asymptomatic after 5.8 years (0.9 - 13.7) follow-up. An umbilical polyp can be present in the absence of other OMD anomalies. Exploration of the peritoneal cavity in children with an umbilical polyp does not seem to be necessary.  相似文献   
5.
The diagnosis of molar pregnancy is a continuing diagnostic problem for many practicing histopathologists who are required to examine specimens of products of conception, particularly since changes in gynecological management in recent years have resulted in uterine evacuation at earlier gestations. The aim of this review is to provide practical, up-to-date, diagnostically useful information regarding the histological diagnosis of molar disease in early pregnancy. Pathophysiological issues relevant to molar pregnancies, such as genetic abnormalities, will be briefly summarized, but nonhistopathological aspects of molar disease will not be covered in detail in this review.  相似文献   
6.
7.
8.
OBJECTIVE: The majority of partial (PHM) and complete (CHM) hydatidiform moles are diagnosed in early pregnancy. About half are identified as molar on ultrasonographic examination prior to evacuation. It is uncertain whether unsuspected cases represent an intrinsically different molar phenotype or are simply dependant on sonographer expertise. We measured a microscopic parameter, average villus diameter, of evacuated PHMs and CHMs to ascertain the cause of non-detection on ultrasound. METHODS: Fifty-four molar pregnancies were examined from the files of the Trophoblastic Disease Unit, in which results of an ultrasound examination prior to evacuation were known. In each, the average cross-sectional diameter of the largest 10 villi was recorded. Maximum villus diameters were compared between gestational age groups (<14 weeks and >or=14 weeks), and ultrasound detection groups (detected (d) and not detected (nd)). RESULTS: The average maximum villus diameter of the largest hydropic villi was significantly less in the first trimester for both PHMs and CHMs that were undetected by ultrasound examination compared to those identified as molar sonographically (P<0.001 and P<0.001, respectively). There was no significant difference in the maximum villus diameter between PHMs and CHMs that were not detected sonographically in the first trimester (P=0.44). Beyond 14 weeks of gestation, there was no significant difference between PHMs detected and undetected sonographically (P=0.88). CONCLUSION: The average diameter of the largest, most hydropic villi, is significantly greater in cases of PHMs and CHMs detected by ultrasound examination in the first trimester compared to that of those not detected sonographically, but beyond 14 weeks such differences are minimal. These findings suggest that, although sonographer expertise could potentially increase ultrasound detection rates somewhat for PHMs and CHMs, a significant proportion of cases demonstrate minimal hydropic change in the first trimester and are therefore likely to remain unidentifiable by ultrasound examination prior to evacuation, even with improved sonographer expertise.  相似文献   
9.
10.
Using a newly devised 50-channel photometer which records the opacity of growing bacterial cultures, it was shown that the time taken by cultures diluted 1/1000 in fresh broth to reach 50% of the opacity of a fully grown culture was inversely related to the concentration of organisms in the original culture. This relation was used to determine the numbers of survivors after exposure to benzylpenicillin and gentamicin alone and in combination. The procedure is commended as a labour-saving and potentially rapid method of obtaining comprehensive information on the bactericidal action and interaction of antibiotics.  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