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   1199篇
  免费   98篇
  国内免费   4篇
耳鼻咽喉   6篇
儿科学   93篇
妇产科学   65篇
基础医学   124篇
口腔科学   30篇
临床医学   111篇
内科学   226篇
皮肤病学   55篇
神经病学   102篇
特种医学   31篇
外科学   102篇
综合类   12篇
一般理论   2篇
预防医学   63篇
眼科学   78篇
药学   112篇
中国医学   5篇
肿瘤学   84篇
  2024年   1篇
  2023年   23篇
  2022年   62篇
  2021年   72篇
  2020年   65篇
  2019年   76篇
  2018年   84篇
  2017年   60篇
  2016年   87篇
  2015年   55篇
  2014年   90篇
  2013年   91篇
  2012年   98篇
  2011年   100篇
  2010年   47篇
  2009年   45篇
  2008年   62篇
  2007年   62篇
  2006年   45篇
  2005年   27篇
  2004年   15篇
  2003年   9篇
  2002年   7篇
  2001年   2篇
  2000年   2篇
  1998年   1篇
  1994年   1篇
  1991年   2篇
  1989年   1篇
  1988年   6篇
  1987年   1篇
  1966年   1篇
  1962年   1篇
排序方式: 共有1301条查询结果,搜索用时 281 毫秒
81.
82.
83.
84.
Objective: To evaluate the thyroid hormone and cortisol levels in neonates with sepsis in relation to the final outcome. It was hypothesized that the hormonal level could act as some prognostic guideline.Methods: Forty nine neonates, aged 8–28 days, diagnosed as neonatal sepsis were selected for the study. Neonates below 8 days of age, 35 weeks of gestation and 2000 g of birth weight were excluded from the study. Twenty FT-AGA neonates beyond day 7 of life served as control for the study. The hormones were estimated by radioimmunoassay.Results: The neonates with sepsis had significantly higher mean serum cortisol and lower mean serum total T4 at admission as compared to healthy neonates. The mean serum total T3 level was also lower, but the difference was not statistically significant. The mean serum TSH levels were comparable in both groups. The levels normalised following recovery. Sixteen neonates succumbed to the disease process. The non-survivors had significantly lower mean total T3 and total T4 levels as compared to the survivors.Conclusion. The endocrinal abnormalities are of transient nature as a response to sepsis. Low total T3 and total T4 are the predictors of adverse outcome in neonates with sepsis.  相似文献   
85.
OBJECTIVES: Placental growth hormone (PGH) is a pregnancy-specific protein produced by syncytiotrophoblast and extravillous cytotrophoblast. No other cells have been reported to synthesize PGH Maternal. PGH Serum concentration increases with advancing gestational age, while quickly decreasing after delivery of the placenta. The biological properties of PGH include somatogenic, lactogenic, and lipolytic functions. The purpose of this study was to determine whether the maternal serum concentrations of PGH change in women with preeclampsia (PE), women with PE who deliver a small for gestational age neonate (PE + SGA), and those with SGA alone. STUDY DESIGN: This cross-sectional study included maternal serum from normal pregnant women (n = 61), patients with severe PE (n = 48), PE + SGA (n = 30), and SGA alone (n = 41). Fetal cord blood from uncomplicated pregnancies (n = 16) and PE (n = 16) was also analyzed. PGH concentrations were measured by ELISA. Non-parametric statistics were used for analysis. RESULTS: (1) Women with severe PE had a median serum concentration of PGH higher than normal pregnant women (PE: median 23,076 pg/mL (3473-94 256) vs. normal pregnancy: median 12 157 pg/mL (2617-34 016); p < 0.05), pregnant women who delivered an SGA neonate (SGA: median 10 206 pg/mL (1816-34 705); p < 0.05), as well as pregnant patients with PE and SGA (PE + SGA: median 11 027 pg/mL (1232-61 702); p < 0.05). (2) No significant differences were observed in the median maternal serum concentration of PGH among pregnant women with PE and SGA, SGA alone, and normal pregnancy (p > 0.05). (3) Compared to those of the control group, the median umbilical serum concentration of PGH was significantly higher in newborns of preeclamptic women (PE: median 356.1 pg/mL (72.6-20 946), normal pregnancy: median 128.5 pg/mL (21.6-255.9); p < 0.01). (4) PGH was detected in all samples of cord blood. CONCLUSIONS: (1) PE is associated with higher median concentrations of PGH in both the maternal and fetal circulation compared to normal pregnancy. (2) Patients with PE + SGA had lower maternal serum concentrations of PGH than preeclamptic patients without SGA. (3) Contrary to previous findings, PGH was detectable in the fetal circulation. The observations reported herein are novel and suggest that PGH may play a role in the mechanisms of disease in preeclampsia and fetal growth restriction.  相似文献   
86.
OBJECTIVE: Interferon (IFN)-gamma inducible protein, CXCL10/IP-10, is a member of the CXC chemokine family with pro-inflammatory and anti-angiogenic properties. This chemokine has been proposed to be a key link between inflammation and angiogenesis. The aim of this study was to determine whether preeclampsia and delivery of a small for gestational age (SGA) neonate are associated with changes in maternal serum concentration of CXCL10/IP-10. STUDY DESIGN: This cross-sectional study included patients in the following groups: (1) non-pregnant women (N = 49); (2) women with normal pregnancies (N = 89); (3) patients with preeclampsia (N = 100); and (4) patients who delivered an SGA neonate (N = 78). SGA was defined as birth weight below the 10th percentile. Maternal serum concentrations of CXCL10/IP-10 were measured by sensitive immunoassay. Non-parametric statistics were used for analysis. RESULTS: (1) Patients with normal pregnancies had a significantly higher median serum concentration of CXCL10/IP-10 than non-pregnant women (median 116.1 pg/mL, range 40.7-1314.3 vs. median 90.3 pg/mL, range 49.2-214.7, respectively; p = 0.002); (2) no significant correlation was found between maternal serum concentration of CXCL10/IP-10 and gestational age (between 19 and 38 weeks); (3) there were no differences in median serum CXCL10/IP-10 concentrations between patients who delivered an SGA neonate and those with normal pregnancies (median 122.4 pg/mL, range 37.3-693.5 vs. median 116.1 pg/mL, range 40.7-1314.3, respectively; p > 0.05); (4) patients with preeclampsia had a higher median serum concentration of CXCL10/IP-10 than normal pregnant women (median 156.4 pg/mL, range 47.4-645.9 vs. median 116.1 pg/mL, range 40.7-1314.3, respectively; p < 0.05); (5) patients with preeclampsia had a higher median concentration of CXCL10/IP-10 than those who delivered an SGA neonate (median 156.4 pg/mL, range 47.4-645.9 vs. median 122.4 pg/mL, range 37.3-693.5, respectively; p < 0.05). CONCLUSIONS: Patients with preeclampsia have significantly higher serum concentrations of CXCL10/IP-10 than both normal pregnant women and mothers who have SGA neonates. These results are likely to reflect an anti-angiogenic state as well as an enhanced systemic inflammatory response in patients with preeclampsia. Alternatively, since preeclampsia and SGA share several mechanisms of disease, it is possible that a higher concentration of this chemokine may contribute to the clinical presentation of preeclampsia in patients with a similar intrauterine insult.  相似文献   
87.
88.
89.
Mycetoma is a chronic granulomatous infection. Lower extremities are commonly involved. A 20-year-old male came with complaints of multiple sinuses on scalp, left eyelid swelling with a sinus and dystopia, since one year. On examination there was relative proptosis in left eye of 2 mm. Computed tomography scan showed soft tissue swelling of the pre-septal area of the left upper eyelid with orbital involvement. Magnetic resonance imaging showed increased left orbital volume and evident dystopia. Microbiology testing of the erosive scalp and lid lesions showed genus Nocardia, suggestive of actinomycetoma. This case is presented as it shows an unusual involvement of the orbit.  相似文献   
90.

Background

The AAST recently developed an emergency general surgery (EGS) disease grading system to measure anatomic severity. We aimed to validate this grading system for acute pancreatitis and compare cross sectional imaging-based AAST EGS grade and compare with several clinical prediction models. We hypothesize that increased AAST EGS grade would be associated with important physiological and clinical outcomes and is comparable to other severity grading methods.

Methods

Single institution retrospective review of adult patients admitted with acute pancreatitis during 10/2014–1/2016 was performed. Patients without imaging were excluded. Imaging, operative, and pathological AAST grades were assigned by two reviewers. Summary and univariate analyses were performed. AUROC analysis was performed comparing AAST EGS grade with other severity scoring systems.

Results

There were 297 patients with a mean (±SD) age of 55?±?17 years; 60% were male. Gallstone pancreatitis was the most common etiology (28%). The overall complication, mortality, and ICU admission rates were 51, 1.3, and 25%, respectively. The AAST EGS imaging grade was comparable to other severity scoring systems that required multifactorial data for readmission, mortality, and length of stay.

Conclusions

The AAST EGS grade for acute pancreatitis demonstrates initial validity; patients with increasing AAST EGS grade demonstrated longer hospital and ICU stays, and increased rates of readmission. AAST EGS grades assigned using cross sectional imaging findings were comparable to other severity scoring systems. Further studies should determine the generalizability of the AAST system.Level of Evidence: IVStudy Type: Single institutional retrospective review
  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