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   1377篇
  免费   107篇
  国内免费   5篇
耳鼻咽喉   16篇
儿科学   25篇
妇产科学   21篇
基础医学   211篇
口腔科学   54篇
临床医学   99篇
内科学   290篇
皮肤病学   161篇
神经病学   54篇
特种医学   44篇
外科学   171篇
综合类   5篇
预防医学   75篇
眼科学   40篇
药学   92篇
中国医学   2篇
肿瘤学   129篇
  2023年   17篇
  2022年   14篇
  2021年   36篇
  2020年   18篇
  2019年   35篇
  2018年   37篇
  2017年   32篇
  2016年   26篇
  2015年   44篇
  2014年   46篇
  2013年   59篇
  2012年   91篇
  2011年   102篇
  2010年   41篇
  2009年   61篇
  2008年   76篇
  2007年   78篇
  2006年   88篇
  2005年   92篇
  2004年   94篇
  2003年   75篇
  2002年   76篇
  2001年   18篇
  2000年   17篇
  1999年   15篇
  1998年   21篇
  1997年   15篇
  1996年   13篇
  1995年   11篇
  1994年   7篇
  1993年   8篇
  1992年   11篇
  1991年   5篇
  1990年   13篇
  1989年   13篇
  1988年   10篇
  1987年   14篇
  1986年   10篇
  1985年   11篇
  1984年   4篇
  1983年   3篇
  1982年   4篇
  1981年   8篇
  1980年   4篇
  1979年   3篇
  1976年   1篇
  1975年   5篇
  1974年   3篇
  1971年   1篇
  1967年   1篇
排序方式: 共有1489条查询结果,搜索用时 15 毫秒
1.
2.
3.
Eight patients underwent pouchmetry at 12 months after creation of the colonic continent urinary reservoir (CUR) for supravesical diversion. Pouchmetry revealed a volume-dependent tonic and phasic increase in pouch pressure in 3 patients who had undergone pouch construction using the partially detubularized right colon (Heineke-Mikulicz type closure after splitting the transverse and ascending colon at the antimesenteric border), whereas the volume-dependent phasic increase in pouch pressure was much less remarkable in 5 patients whose pouch was constructed using the totally detubularized right colon (Heineke-Mikulicz type closure after splitting the whole colonic segment including the cecum). The maximum pouch pressure at the pouch volume of 400 to 500 ml was significantly higher (p less than 0.05) in the partial detubularization group (46 +/- 6.0 cmH2O, mean +/- S.D.) than in the total detubularization group (12 +/- 1.6 cmH2O). In creation of the low-pressure pouch using the right colon, detubularization should extend to the whole portion of the isolated colonic segment.  相似文献   
4.
Objective: We assessed the current role of preoperative and intraoperative autologous blood donation in pediatric open-heart surgery. Methods: Group 1 consisted of 51 patients between 5 and 10 years old who underwent preoperative autologous blood donation. Group 2 consisted of 50 age-matched patients without preoperative donation as controls. Intraoperative donation was conducted in both groups prior to cardiopulmonary bypass. We evaluated perioperative blood cell count, blood loss, and the need for homologous blood products. Results: No serious complications occurred in preoperative or intraoperative donation. Total preoperative donation storage was 17.5±3.4 mL/kg. Intraoperative donation was 21.7 ±6.1 mL/kg in Group 1 and 12.8±4.0 mL/kg in Group 2 (p<0.001). On admission, serum hemoglobin was lower in Group 1 (12.2±1.0 g/dL versus 13.6±1.6 g/dL, p<0.001) but returned postoperatively to the preoperative value. It hovered at a depressed level in Group 2 (12.2±1.4 versus 10.2±1.1 g/dL, p<0.001). The homologous blood requirement was significantly less in Group 1 than in Group 2 (0% versus 10%, p<0.05). Postoperative platelet counts showed similar curves, and blood loss was not statistically significantly different between groups. Conclusion: Preoperative and intraoperative donations are safe and continue to contribute uniquely to blood conservation, providing important options in comprehensive blood conservation programs in current pediatric open-heart surgery.  相似文献   
5.
6.
The diagnosis and choice of treatment for dermatophytoses are usually based on the result of microscopic observation of hyphal elements and culture. However, false negative cultures have sometimes been encountered and appropriate timing of discontinuation of treatment has not been formulated. In this study, we attempted the identification and viability assessment of dermatophytes based on the quantitative measurement of dermatophyte actin (ACT) mRNA. An internal fragment of the ACT, 725 to 762 bp, was isolated by PCR from the genomic DNA of dermatophytes and sequenced. ACT intron-based primers were dermatophyte species-specific and primer pairs crossing the intron were dermatophyte genus-specific. The LightCycler (LC) instrument, employing the two-step RT-PCR/fluorescent hybridization system, was used to quantify the actin mRNA (ACT) of dermatophytes. A 669 bp ACT cDNA fragment was used as a quantification standard. Several mg of samples were collected from skin scales or nail plates before and after the treatment using oral terbinafine. The results indicated that quantification of ACT mRNA correlated with the results of culture and KOH examination and that copy numbers of dermatophyte ACT mRNA per mg sample decreased with progression of the therapy. This method comprises a sensitive (1 fg), specific, rapid (< 4 h) and quantitative assessment of the viability and identification of dermatophytes in skin tissue.  相似文献   
7.
8.
The E4 open reading frame (ORF) of human papillomaviruses (HPVs) is transcribed in abundant mRNAs encoding an fusion gene during the productive infection, and the HPV 16 E7 ORF encodes an oncoprotein detectable in the cell lines derived from cervical carcinoma. We examined 421 human sera, which included 108 samples from the patients with cervical carcinoma, for the presence of IgG antibodies against the HPV 16 E4 and E7 proteins by enzyme-linked immunosorbent assay. Bacterially expressed fusion protein lac- and nonfusion protein E7 were purified and used as antigens. All of the 22 serum samples positive for anti-E7 antibody and the 11 out of 15 samples positive for anti- antibody were from the patients with cervical carcinoma, but only one sample was found to contain both anti- and anti-E7 antibodies. These findings show specific and independent association of these antibodies with cervical carcinoma.  相似文献   
9.
10.
Summary The characteristics of the non-adrenergic, noncholinergic inhibitory response of the rat stomach fundus to transmural nerve stimulation were compared with the relaxation induced by vasoactive intestinal polypeptide (VIP). Treatment with -chymotrypsin (5 U/ml) or VIP antiserum (1:200) significantly reduced the relaxation induced by transmural nerve stimulation at 30 Hz, indicating that the possible transmitter in the non-adrenergic, non-cholinergic nerves is a peptide and may be VIP or a closely related peptide. VIP was able to relax, fully and dose-dependently, the stomach fundus that had previously been constricted by treatment with 10–6 M serotonin, and the IC50 value for VIP was 2.4 × 10–9 M. VIP elevated levels of cyclic AMP in a dose-dependent manner and the EC50 value was 2.8 × 10–9 M in the presence of 10–6 M atropine and 10–6 M guanethidine. The stomach fundus was relaxed by transmural nerve stimulation (30 Hz, 50 mA) and transmural nerve stimulation also caused production of cyclic AMP in the rat stomach in the presence of atropine and guanethidine. The basal level of cyclic AMP in the stomach was 8.7 ± 0.26 pmole/mg protein. When transmural nerve stimulation was applied for 5 min, the contraction of the stomach, induced by 10–6 M serotonin, was inhibited by 54% in the presence of atropine and guanethidine and the level of cyclic AMP was increased to 13.0 ± 0.73 pmol/mg protein. Apamin inhibited the transmural nerve stimulation-induced relaxation and shifted the dose-response curve for VIP to the right. These results suggest that one of the putative neurotransmitter from non-adrenergic, non-cholinergic nerves in the rat stomach is VIP and that VIP-induced relaxation may be mediated by the production of cyclic AMP and by the opening of apamin-sensitive K+-channels.Send offprint requests to K. Kamata at the above address  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