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   2715篇
  免费   182篇
  国内免费   44篇
耳鼻咽喉   29篇
儿科学   76篇
妇产科学   33篇
基础医学   321篇
口腔科学   60篇
临床医学   186篇
内科学   775篇
皮肤病学   30篇
神经病学   204篇
特种医学   136篇
外科学   500篇
综合类   10篇
预防医学   62篇
眼科学   66篇
药学   128篇
中国医学   6篇
肿瘤学   319篇
  2024年   7篇
  2023年   41篇
  2022年   69篇
  2021年   131篇
  2020年   67篇
  2019年   82篇
  2018年   85篇
  2017年   80篇
  2016年   76篇
  2015年   102篇
  2014年   91篇
  2013年   115篇
  2012年   198篇
  2011年   170篇
  2010年   97篇
  2009年   88篇
  2008年   139篇
  2007年   154篇
  2006年   124篇
  2005年   127篇
  2004年   112篇
  2003年   91篇
  2002年   99篇
  2001年   46篇
  2000年   46篇
  1999年   47篇
  1998年   41篇
  1997年   27篇
  1996年   36篇
  1995年   23篇
  1994年   22篇
  1993年   17篇
  1992年   31篇
  1991年   32篇
  1990年   19篇
  1989年   21篇
  1988年   15篇
  1987年   14篇
  1986年   19篇
  1985年   12篇
  1984年   11篇
  1983年   11篇
  1982年   8篇
  1981年   10篇
  1980年   10篇
  1979年   12篇
  1975年   7篇
  1972年   7篇
  1969年   6篇
  1967年   7篇
排序方式: 共有2941条查询结果,搜索用时 15 毫秒
61.
Graefe's Archive for Clinical and Experimental Ophthalmology - To clarify the prevalence of secondary glaucoma (SG) and its speed of progression in patients with herpes simplex virus...  相似文献   
62.
63.
64.

Background

Erythropoiesis-stimulating agents (ESAs) are standard therapy for chronic kidney disease (CKD) patients with renal anemia. However, few studies have compared the effects of different ESAs on anemia in identical pre-dialysis CKD patients.

Methods

Seventy-nine patients who switched from epoetin beta to darbepoetin alfa (Group 1), and 82 patients who switched from darbepoetin alfa to epoetin beta pegol (Group 2) were enrolled in this study. Clinical and laboratory parameters were assessed for 6 months before and after switching ESAs. The prevalence of adverse events, the dose conversion ratio of ESAs, and the frequency of ESA administration were also analyzed.

Results

Analysis of variance showed that switching ESAs did not significantly change hemoglobin levels for the study duration in both groups (mean hemoglobin 10.3–10.5 g/dL in Group 1 and 10.4–10.7 g/dL in Group 2). Estimated glomerular filtration rate, blood pressure, transferrin saturation, ferritin, and albumin remained constant in both groups. The prevalence of adverse effects was quite low (0–3.8 %) during both 6-month study periods. The mean dose conversion ratio for epoetin beta:darbepoetin alfa was 163.7 units:1 μg and for darbepoetin alfa:epoetin beta pegol was 1.08 μg:1 μg. The intervals of ESA administration significantly differed (epoetin beta pegol > darbepoetin alfa > epoetin beta).

Conclusions

Epoetin beta, darbepoetin alfa, and epoetin beta pegol are effective and well-tolerated agents for managing anemia in Japanese pre-dialysis CKD patients. The intervals of ESA administration to maintain a patient’s target hemoglobin were longer in the order of epoetin beta pegol > darbepoetin alfa > epoetin beta.  相似文献   
65.
Esophagus - This study investigated potential determinants of reflux perception in patients with non-erosive reflux disease (NERD) who had reflux-related symptoms on potassium-competitive acid...  相似文献   
66.
Esophagus - There is no consensus on the relationship between saliva secretion and non-erosive reflux disease (NERD). In this study, saliva secretion and salivary epidermal growth factor (EGF) in...  相似文献   
67.
Esophagus - Salivary secretion in patients with proton-pump inhibitor (PPI)-resistant severe reflux esophagitis has not been examined. In this study, saliva secretion and salivary epidermal growth...  相似文献   
68.
BACKGROUND: Takotsubo cardiomyopathy is triggered by emotional or physical stress especially in post-menopausal women. A reduction in estrogen levels following menopause might underlie the high incidence of takotsubo cardiomyopathy. METHODS AND RESULTS: The left ventricular contraction between ovariectomized rats (OVX) and OVX with estrogen supplementation (OVX + E) while subjected to immobilization stress (IMO) was compared. The IMO in combination with general anesthesia impaired the left ventricular contraction in both OVX and OVX + E. Estrogen supplementation tended to improve the IMO-induced cardiac dysfunction and significantly attenuated the increase of blood pressure and heart rate. To understand the protective mechanism of estrogen, the expression of c-fos mRNA, a marker of cellular activation was compared. The mRNA expression of cardioprotective substances in the heart was also investigated. In the OVX + E, the levels of c-fos mRNA were significantly decreased in the paraventricular hypothalamic nucleus, adrenal gland and left ventricle, suggesting that an increase of estrogen attenuates the emotional stress-induced hypothalamo-sympatho-adrenal outflow from the central nervous system to the target organs. An expression of heat shock protein 70 and atrial natriuretic peptide was significantly augmented in the OVX + E. CONCLUSIONS: These data suggest that estrogen supplementation partially prevents emotional stress-induced cardiovascular responses both by indirect action on the nervous system and by direct action on the heart.  相似文献   
69.
ObjectiveFibrotic changes in the vocal fold mucosa have been observed in patients with vocal fold scarring, aged vocal fold, and sulcus vocalis, which often lead to severe voice disorders. Previous research suggests that the basic fibroblast growth factor (b FGF) improves variations in vocal fold properties [1,2]. Although clinical studies on b FGF treatments have been conducted [3,4,5], these studies only demonstrated the efficacy of this drug over a short period. The present study is the first to investigate the long-term efficacy of b FGF treatment.Methodsb FGF injections were performed in six patients from January of 2016 to December of 2017 at our institution. Patient follow-up continued for at least two years after the last injection. Three patients had vocal fold scarring, two had aged vocal fold atrophy, and one patient had sulcus vocalis. Each vocal fold was injected with 10 µg of b FGF four times. Voice and stroboscopic examinations were performed after surgery (at one month, three months, six months, one year, two years). Fundamental frequency, maximum phonation time (MPT), mean flow rate (MFR), amplitude perturbation quotient (APQ), pitch perturbation quotient (PPQ), and noise-to-harmonic ratio (NHR), and voice handicap index-10 (VHI-10) were examined and compared statistically between the pretreatment time and at each posttreatment time point.ResultsThe speaking F0 had an obvious decreasing tendency, with significant differences suggesting the increase in volume in the vocal folds. Aerodynamic parameters also showed small improvements. The most remarkable improvement was observed in the acoustic parameters, indicating that the treatment could improve the vocal fold to make vibrations symmetrically and regularly for a long period. Achievement of symmetry and regularity on vocal fold vibrations suggested the property changes had happened in the vocal folds. Consequently, the score of VHI-10 had improved, indicating high patient satisfaction with this treatment.Conclusionb FGF injections could be a reliable treatment option for diseases that deteriorate the property of vocal fold.  相似文献   
70.
The purpose of this study was to analyze passive motion of the para- and retropharyngeal space (PRS) during swallowing using dynamic magnetic resonance imaging (MRI). We conducted a preliminary study involving 30 healthy volunteers who underwent dynamic MRI. Consecutive MRI axial images were obtained by examining the plane parallel to the hard palate at the level of the anterior inferior corner of C2. Anterior displacement of the posterior pharyngeal wall (PPW) was measured as a motion index of pharyngeal contraction. The displacement and internal angle of the bilateral external and internal carotid arteries (ECA and ICA) and the bilateral centroids of the PRS area, as well as the increase in PRS area, were calculated at rest and at maximum pharyngeal contraction. In most participants, the bilateral ECA, ICA, and centroids were anterointernally displaced by pharyngeal contraction. The normalized ECA displacement (r = 0.64, r 2 = 0.41), normalized ICA displacement (r = 0.60, r 2 = 0.37), and normalized centroid displacement (r = 0.43, r 2 = 0.19) were more than moderately positively correlated with the normalized PPW displacement. The normalized PRS area increase (r = 0.35, r 2 = 0.12) was weakly positively correlated with the normalized PPW displacement. These results revealed that PRS area increased as the ECA and ICA were drawn anterointernally via its passive motion by pharyngeal contraction.  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