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   6999篇
  免费   516篇
  国内免费   24篇
耳鼻咽喉   122篇
儿科学   414篇
妇产科学   169篇
基础医学   1045篇
口腔科学   81篇
临床医学   501篇
内科学   1521篇
皮肤病学   212篇
神经病学   287篇
特种医学   183篇
外科学   692篇
综合类   325篇
一般理论   1篇
预防医学   487篇
眼科学   174篇
药学   649篇
中国医学   37篇
肿瘤学   639篇
  2023年   40篇
  2021年   190篇
  2020年   106篇
  2019年   117篇
  2018年   144篇
  2017年   118篇
  2016年   166篇
  2015年   193篇
  2014年   243篇
  2013年   310篇
  2012年   446篇
  2011年   424篇
  2010年   279篇
  2009年   256篇
  2008年   354篇
  2007年   316篇
  2006年   287篇
  2005年   271篇
  2004年   241篇
  2003年   234篇
  2002年   205篇
  2001年   198篇
  2000年   182篇
  1999年   149篇
  1998年   92篇
  1997年   73篇
  1996年   69篇
  1995年   60篇
  1994年   71篇
  1993年   70篇
  1992年   110篇
  1991年   99篇
  1990年   96篇
  1989年   83篇
  1988年   92篇
  1987年   84篇
  1986年   79篇
  1985年   75篇
  1984年   48篇
  1983年   49篇
  1981年   38篇
  1980年   39篇
  1979年   54篇
  1978年   45篇
  1976年   49篇
  1975年   40篇
  1974年   46篇
  1972年   52篇
  1971年   37篇
  1970年   37篇
排序方式: 共有7539条查询结果,搜索用时 43 毫秒
1.
2.
OBJECTIVE: Nocturnal enuresis is a common pediatric problem, the etiology of which is unclear. In recent years, various studies have been published stating that children with nocturnal enuresis exhibit growth and skeletal maturation retardation. METHODS: In this cross-sectional study, we included 27 patients (16 boys, 11 girls) between the ages of 6 and 14 years who had presented with primary nocturnal enuresis (PNE) complaints. We included in the evaluation 19 healthy subjects (12 boys, 7 girls), who were the siblings of the children with PNE, as the control group. RESULTS: The patients in both groups were similar in chronological age, bone age, height and weight, with no significant difference between groups (P>0.05). CONCLUSION: The two groups in our study consisted of the same genetic background. Thus, our results were found to be different from the previous studies. We have concluded that there is no direct relationship between enuresis nocturnal and skeletal maturation.  相似文献   
3.
Out of 36511 patients attending the ENT OHD of R. G,. Aur Medical Callege & Hospital. Kolkata, in one year 0.08% patients were found tuning naspharyngeal mass. 30 cases of nasopharyngeal mass were studied. The peak incidence of nasopharyngeal mass was in the age group between II to 20 years (40%). The incidence in males (73%) was more than females(27%). The maximum ineldence was found among students (74%). Commonest ntuopharyngeal nuns teas antrochoanal polyp (30%). Next commlon masses were adenoids (23%)Juvenile angwfibroma(20%) and nasophartngeal carcinoma (13%). Nasal obstruction was the main presenting symptom(83%) followed by epistaxis (40%).  相似文献   
4.
5.
After the interaction of estrogen with the ligand binding domain (LBD) of mouse estrogen receptor‐α (mERα) and hormone‐responsive elements of target genes, many nuclear proteins are recruited to regulate the expression of specific genes. Because it is not known which brain proteins interact with LBD or whether these proteins vary with age and sex, we used pull‐down assay and far Western blotting to detect five nuclear proteins of 160, 140, 87, 60, and 46 kD in the mouse brain. These interacting proteins were identified as PELP1, RIP140, PGC1α, BAF60, and ADA3, respectively. The level of PELP1, RIP140, PGC1α, and BAF60 decreased drastically in old compared with adult male mice, whereas the ADA3 level showed no significant change. PELP1, PGC1α, and BAF60 levels were lower in old male compared with female mice. Thus we report the identification and interaction of five nuclear proteins with mERα‐LBD, indicating their role in estrogen signaling and brain functions during aging. © 2009 Wiley‐Liss, Inc.  相似文献   
6.
7.
A 27-month longitudinal study of 140 Bangladeshi mothers living in three tea gardens examined the effect of maternal factors (mother's age, number of live births, birth interval, and mother's work status) and sex of the infant on the duration and bout frequency of breastfeeding over 8-hr daytime periods. Prolonged breastfeeding of the infant was observed, but there was a sharp decline in duration of breastfeeding over the first 6 months, followed by a more gradual diminution thereafter. The feeding bouts showed a different pattern, with a more gradual decline over time. Housewives consistently showed a greater duration and bout frequency than women in paid employment as tea-pluckers. Over the first 6 months, primigravid mothers breastfed more frequently, but not thereafter. Older mothers (>35 years of age) breastfed with higher frequency during the first 2 months, but thereafter, the bout frequency decreased with increasing age of the infant. Over the 27-month study, maternal work status was the main factor associated with the duration and frequency of breastfeeding, with significantly higher frequency and duration among housewives. However, in the first 6 months after birth, there was very little difference in frequency or duration of breastfeeding between tea-workers and housewives, indicating that working mothers probably adjusted their time to breastfeed their infants before going, or after coming back, from work.  相似文献   
8.
Sixteen patients receiving percutaneous endoscopic gastrostomy (PEG) feeding following a period of nasogastric (NG) feeding were investigated to assess acceptance and identify problems by means of a questionnaire. PEG was considered to be superior to NG feeding in terms of tolerance and cosmetic acceptance by 81% and 88% of participants respectively ( P < 0.001). Pain was an infrequent problem. Interruptions to feeding were consideed to be more common with NG feeding by 50% of participants; 38% considered interruptions equally common with both PEG and NG, and 12% considered interruptions more common with PEG feeding ( P = NS). The time for care was equivalent for both methods. Seventy-five percent considered PEG to have made a valuable contribution to enteral feeding. Leakage was however considered to be more frequent in PEG feeding by 81% of participants (compared to 12% who considered leakage to be more common with NG feeding; P < 0.001) and leakage was more frequent at die junctions in the catheter rather than from the stoma. Thirty-one percent of patients with PEG had needed systemic antibiotics for stomal infections. All patients with both PEG and NG feeding needed professional help. Sixty-two percent needed professional help more frequently with PEG than with NG feeding (compared to 19% who considered that the NG tube needed professional help more frequently; P <0.05). We conclude that leakage and infections are major problems in PEG enteral feeding.  相似文献   
9.
10.
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