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   1702篇
  免费   80篇
  国内免费   8篇
耳鼻咽喉   8篇
儿科学   28篇
妇产科学   26篇
基础医学   304篇
口腔科学   18篇
临床医学   156篇
内科学   244篇
皮肤病学   28篇
神经病学   174篇
特种医学   108篇
外科学   277篇
综合类   20篇
一般理论   1篇
预防医学   147篇
眼科学   29篇
药学   151篇
肿瘤学   71篇
  2022年   11篇
  2021年   14篇
  2020年   11篇
  2019年   26篇
  2018年   20篇
  2017年   14篇
  2016年   18篇
  2015年   32篇
  2014年   37篇
  2013年   53篇
  2012年   74篇
  2011年   123篇
  2010年   63篇
  2009年   53篇
  2008年   79篇
  2007年   98篇
  2006年   100篇
  2005年   94篇
  2004年   86篇
  2003年   89篇
  2002年   80篇
  2001年   29篇
  2000年   30篇
  1999年   31篇
  1998年   27篇
  1997年   25篇
  1996年   16篇
  1995年   20篇
  1994年   13篇
  1993年   23篇
  1992年   16篇
  1991年   14篇
  1990年   14篇
  1989年   14篇
  1987年   11篇
  1986年   12篇
  1985年   14篇
  1984年   12篇
  1982年   14篇
  1981年   10篇
  1980年   12篇
  1979年   17篇
  1978年   14篇
  1977年   21篇
  1976年   16篇
  1974年   11篇
  1973年   13篇
  1972年   14篇
  1970年   12篇
  1966年   10篇
排序方式: 共有1790条查询结果,搜索用时 187 毫秒
1.
2.
Therapeutic drug monitoring generally focuses on the plasma compartment only. Differentiation between the total plasma concentration and the free fraction (plasma water) has been described for a number of limited drugs. Besides the plasma compartment, blood has also a cellular fraction which has by far the largest theoretical surface and volume for drug transport. It is with anti-cancer drugs that major progress has been made in the study of partition between the largest cellular blood compartment, i.e., erythrocytes, and the plasma compartment. The aim of the present review is to detail the progress made in predicting what a drug does in the body, i.e., pharmacodynamics including toxicity and plasma and/or red blood cell concentration monitoring. Furthermore, techniques generally used in anti-cancer drug monitoring are highlighted. Data for complex Bayesian statistical approaches and population kinetics studies are beyond the scope of this review, since this is generally limited to the plasma compartment only.  相似文献   
3.
A number of novel pyridazinomorphinans have been synthesized by the inverse electron demand Diels-Alder reaction of various 3,6-disubstituted 1,2,4,5-tetrazines with enamines derived from dihydrocodeinone and with codeinone. Reduction of some of the pyridazinomorphinans did not furnish the expected pyrroloepoxymorphinans; in all cases investigated reductive cleavage of the epoxybridge was observed to yield dihydropyridazino- or pyrrolomorphinans. The structures of all new compounds were assigned by the spectral data, that of the cycloadduct of codeinone was additionally verified by X-ray crystallography. Compounds 5a, 8, 11a , and 16 have been evaluated for their affinity at μ and κ opioid receptors in radioligand binding assays. Their ability to inhibit [3H]DAMGO binding at μ and [3H]U 69.593 binding at κ receptors, respectively as compared to codeine has been found to be lower.  相似文献   
4.
PURPOSE: Accuracy of measurement of low hemoglobin concentrations using the HemoCue, a B-hemoglobin photometer (HemoCue AB, Angelholm, Sweden) may exhibit significant variability. Infusion of hemoglobin-based oxygen carriers (HBOC) results in low concentrations of plasma hemoglobin. Our study assessed B-hemoglobin photometer measurement accuracy of three HBOC: (hemoglobin glutamer-200 (bovine; Oxyglobin, Biopure Corp., Cambridge, MA, USA); hemoglobin glutamer-250 (bovine; Hemopure, Biopure Corp, Cambridge, MA, USA), and hemoglobin-raffimer, (human; Hemolink, Hemosol, Inc., Toronto, Ontario, Canada). METHODS: In the laboratory, 45 split canine plasma samples were mixed with hemoglobin glutamer-200 (8.13, 16.25, 32.5 g x L(-1) concentrations), 45 samples were mixed with hemoglobin glutamer-250 (8.13, 16.25, 32.5 g x L(-1) concentrations), 45 with hemoglobin-raffimer (12.5, 25.0, 50.0 g x L(-1) concentrations), and measured. Plasma samples without HBOC served as control. Hemoglobin concentration was determined by a laboratory analyzer (Coulter Corporation, Hiafeah, FL, USA) and B-hemoglobin photometer (HemoCue, Angelholm, Sweden). Two independent technicians performed blinded sample measurements and randomly tested each sample five times. Results were analyzed according to Bland and Altman analysis. RESULTS: B-hemoglobin photometer demonstrated high repeatability for all three HBOCs. Repeatability coefficients were 0.37 g x L(-1) and 0.48 g x L(-1) for hemoglobin glutamer-200, 0.39 g x L(-1) and 0.4 g x L(-1) for hemoglobin glutamer-250 and 1.07 g x L(-1) and 0.85 g x L(-1) for hemoglobin-raffimer. An acceptable agreement was found between the B-hemoglobin photometer and the laboratory analyzer for all three HBOCs tested. CONCLUSION: The B-hemoglobin photometer accurately determined the concentration of three HBOC solutions dissolved in canine plasma.  相似文献   
5.
Urinary dysfunction is very common in idiopathic Parkinson's disease (PD) and manifests primarily with symptoms of overactive bladder (OAB). Affection of central serotonergic systems has been suggested to play a role in OAB. The objective of this study was to evaluate whether in PD patients with OAB symptoms a specific alteration of the brainstem raphe (BR), which contains serotonergic neurons, can be detected with transcranial sonography (TCS). Of 116 PD patients enrolled, 19 had PD-related OAB symptoms (OAB+) unlike remaining 97 patients (OAB−). Patients were examined by a sonographer blinded to the clinical data. Reduced echogenicity of BR was found in 12 (63%) OAB+ patients but only in 18 (19%) of 93 assessable OAB− patients (Mann–Whitney U -test, P  < 0.001). In OAB+ patients, lower raphe echogenicity score was associated with longer duration of OAB symptoms ( anova , P  = 0.033). Other TCS findings such as echogenicity of substantia nigra, thalami, lenticular and caudate nuclei, and widths of third and lateral ventricles did not differ between OAB+ and OAB− patients. TCS findings suggest a pathogenetic role of BR in OAB related to PD. Alterations may reflect disturbance of its central serotonergic system.  相似文献   
6.
The internal anatomy of the median nerve in the region of the elbow has been studied by microdissection in 20 cadavers. Gross branching patterns were studied in an additional 14 cadavers. There are four major branches or branch groups: I to pronator teres, II to flexor carpi radialis, flexor digitorum superficialis, and palmaris longus; III to the anterior interosseous nerve; and IV to flexor digitorum superficialis. Three of these could be traced proximally within the main trunk of the median nerve, the average being I-10 cm; III-7.5 cm; IV-2 cm. This information should have clinical applications in repair and grafting of the median nerve near the elbow and in understanding clinical nerve compression sydromes.  相似文献   
7.
8.
9.
Azulenes as Dienophiles in the [4+2]-Cycloaddition with Inverse Electron Demand, a Supplement [4+2] Cycloadditions of azulene ( 2 ) und 1-Nitroazulene ( 14 ) with the extremely electron-deficient, s-cis-fixed diazadiene system of 3,6-bis(trifluoromethyl)-1,2,4,5-tetrazine ( 1 ) are described. In addition to earlier findings 1 reacts with 2 probably in a two step [4+2] cycloaddition via 8 and 10 to yield the benzo[f]phthalazine 5a , via 8 and 9 to furnish the azuleno[d]pyridazine 3 and the azine 4 . The reaction of 1 with 1-Nitroazulene ( 14 ) leads to the azuleno[d]pyridazines 3 and 19 in low yield.  相似文献   
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