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   2303篇
  免费   137篇
  国内免费   17篇
耳鼻咽喉   13篇
儿科学   74篇
妇产科学   70篇
基础医学   284篇
口腔科学   42篇
临床医学   195篇
内科学   515篇
皮肤病学   39篇
神经病学   137篇
特种医学   73篇
外科学   375篇
综合类   48篇
预防医学   167篇
眼科学   79篇
药学   192篇
中国医学   5篇
肿瘤学   149篇
  2023年   12篇
  2022年   59篇
  2021年   93篇
  2020年   46篇
  2019年   74篇
  2018年   75篇
  2017年   54篇
  2016年   77篇
  2015年   48篇
  2014年   91篇
  2013年   127篇
  2012年   159篇
  2011年   164篇
  2010年   122篇
  2009年   116篇
  2008年   144篇
  2007年   134篇
  2006年   107篇
  2005年   95篇
  2004年   85篇
  2003年   77篇
  2002年   66篇
  2001年   29篇
  2000年   24篇
  1999年   14篇
  1998年   14篇
  1997年   13篇
  1996年   13篇
  1995年   15篇
  1994年   11篇
  1993年   12篇
  1992年   10篇
  1991年   14篇
  1990年   17篇
  1989年   19篇
  1988年   15篇
  1987年   15篇
  1986年   14篇
  1985年   15篇
  1983年   15篇
  1981年   9篇
  1980年   12篇
  1979年   15篇
  1978年   13篇
  1974年   11篇
  1973年   12篇
  1972年   10篇
  1971年   8篇
  1970年   10篇
  1966年   7篇
排序方式: 共有2457条查询结果,搜索用时 15 毫秒
1.
2.
HLA/Bf haplotypes were examined in a large three-generation Newfoundland family with a high incidence of Graves' disease. In that family Graves' disease was inherited in association with the haplotype HLA Aw24, Bw39 in some instances and with HLA B8-containing haplotypes in other instances. As all seven members of the family who suffered from Graves' disease were homozygous for the Bf S allele, the study for Bf was uninformative. However, the examination of other HLA/Bf haplotypes disclosed some interesting associations. One-hundred-and-five out of 168 HLA-A, -B, -Bf haplotypes were Bf S. Although numerically deviant, no unusual HLA B/Bf associations were observed. Bf F entered the family only once. A new finding is the association between HLA B27 and Bf S1; the haplotype entered the family once and was passed on to eight family members over three generations. Bf S1 was previously reported in association with HLA B12 or W21. None of these family members had ankylosing spondylitis. The Bf allele F1 entered the family three times, always in association with HLA B18.  相似文献   
3.
4.
The purpose of this study was to determine the influence of first-week nutrition intake on neonatal growth in moderate preterm (MP) infants. Data on neonatal morbidity and nutrition intake on day of life 7 (DoL7) were prospectively collected from 735 MP infants (320/7–346/7 weeks gestational age (GA)). Multivariable regression was used to assess the factors associated with extrauterine growth restriction (EUGR) defined as a decrease of more than 1 standard deviation (SD) in the weight z-score during hospitalization. Mean (SD) gestational age and birth weight were 33.2 (0.8) weeks and 2005 (369) g. The mean change in the weight z-score during hospitalization was −0.64 SD. A total of 138 infants (18.8%) had EUGR. Compared to adequate growth infants, EUGR infants received 15% and 35% lower total energy and protein intake respectively (p < 0.001) at DoL7. At DoL7, each increase of 10 kcal/kg/d and 1 g/kg/d of protein was associated with reduced odds of EUGR with an odds ratio of 0.73 (95% CI, 0.66–0.82; p < 0.001) and 0.54 (0.44–0.67; p < 0.001), respectively. Insufficient energy and protein intakes on DoL7 negatively affected neonatal growth of MP infants. Nutritional support should be optimized from birth onwards to improve neonatal weight growth.  相似文献   
5.
6.
Effects of different concentrations of tetrakis--3,5-diisopropylsalicylatodiaquodicopper(II) (Cu(II)2(3,5-DIPS)4(H2O)2) on the reduced status of glutathione (GSH), the major nonprotein thiol in tissues, were investigated using freshly isolated hepatocytes. Cu(II)2(3,5-DIPS)4 below 100 M did not have any significant effects on either the GSH content or viability of the hepatocytes, but at 150–250 M it decreased both parameters after 1 h of incubation. The decrease in cellular GSH was not followed by an increase in the oxidized form of GSH (GSSG) in the cell suspension. The addition of deferoxamine with Cu(II)2(3,5-DIPS)4 to the hepatocyte suspension prevented depletion in GSH content and loss of cell viability by Cu(II)2(3,5-DIPS)4. Both GSH depletion and loss of cell viability were found to be Cu(II)2(3,5-DIPS)4 dose dependent. From these results, it appears that Cu(II)2(3,5-DIPS)4 penetrated the cell membrane and acted by decreasing the GSH level by forming a copper-glutathione complex.  相似文献   
7.
Implications: We report a case of a patient who developed membranous tracheal disruption after severe vomiting. He subsequently required urgent colectomy for toxic megacolon under general anesthesia. With this challenging situation, we were able to successfully conduct general anesthesia in the presence of tracheal laceration, pneumothorax, and pneumomediastinum.  相似文献   
8.
Migraine is a neurological disorder characterized by severe headaches, visual aversions, auditory, and olfactory disorders, accompanied by nausea and vomiting. Zolmitriptan (ZMT®) is a potent 5HT1B/1D serotonin receptor agonist frequently used for the treatment of migraine. It has erratic absorption from the gastrointestinal tract (GIT), but its oral bioavailability is low (40–45%) due to the hepatic metabolism. This makes it an ideal candidate for oral fast dissolving formulations. Hence, the current study was undertaken to design and develop oral fast-dissolving films (OFDFs) containing ZMT for migraine treatment. The OFDFs were formulated by the solvent casting method (SCM) using Pullulan (PU) and maltodextrin (MDX) as film-forming agents and propylene glycol (PG) as a plasticizer. The strategy was designed using Box–Behnken experimental design considering the proportion of PU:MDX and percentage of PG as independent variables. The effectiveness of the OFDF’s was measured based on the following responses: drug release at five min, disintegration time (D-time), and tensile strength (TS). The influence of formulation factors, including percent elongation (%E), thickness, water content, moisture absorption, and folding endurance on ZMT-OFDFs, were also studied. The results showed a successful fabrication of stable ZMT-OFDFs, with surface uniformity and amorphous shape of ZMT in fabricated films. The optimized formulation showed a remarkable rapid dissolution, over 90% within the first 5 min, a fast D-time of 18 s, and excellent mechanical characteristics. Improved maximum plasma concentration (C max) and area under the curve (AUC 0–t) in animals (rats) treated with ZMT-OFDFs compared to those treated with an intra-gastric (i-g) suspension of ZMT were also observed. Copolymer OFDFs with ZMT is an exciting proposition with great potential for the treatment of migraine headache. This study offers a promising strategy for developing ZMT-OFDFs using SCM. ZMT-OFDFs showed remarkable rapid dissolution and fast D-time, which might endeavor ZMT-OFDFs as an auspicious alternative approach to improve patient compliance and shorten the onset time of ZMT in migraine treatment.  相似文献   
9.
10.
This investigation was conducted to evaluate the effect of deferasirox on selenium toxicity in male rat organs. After 50 days of selenium administration, all the rats showed toxicity symptoms. After poisoning, deferasirox was given orally to rats during 10 days. The results show that toxicity symptoms were unexpectedly increased. The new symptoms of toxicity after deferasirox administration were including loss of body hairs, yellowish discoloration of hair, weakness, brown spot on their skin, enlargement of the spleen and shrinking of sex organs. Selenium and iron concentrations were determined by GFAAS and FAAS, respectively. The results indicate the poisoned rats with selenium that received deferasirox as a drug, shown serious symptoms such as exacerbate toxicity, reduction in iron concentration, anemia and even death after a few days of deferasirox administration.  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