全文获取类型
收费全文 | 19936篇 |
免费 | 1401篇 |
国内免费 | 39篇 |
学科分类
医药卫生 | 21376篇 |
出版年
2023年 | 81篇 |
2022年 | 140篇 |
2021年 | 320篇 |
2020年 | 223篇 |
2019年 | 359篇 |
2018年 | 443篇 |
2017年 | 286篇 |
2016年 | 370篇 |
2015年 | 403篇 |
2014年 | 562篇 |
2013年 | 904篇 |
2012年 | 1316篇 |
2011年 | 1389篇 |
2010年 | 739篇 |
2009年 | 675篇 |
2008年 | 1316篇 |
2007年 | 1334篇 |
2006年 | 1308篇 |
2005年 | 1294篇 |
2004年 | 1202篇 |
2003年 | 1127篇 |
2002年 | 1151篇 |
2001年 | 316篇 |
2000年 | 304篇 |
1999年 | 319篇 |
1998年 | 298篇 |
1997年 | 199篇 |
1996年 | 211篇 |
1995年 | 156篇 |
1994年 | 141篇 |
1993年 | 147篇 |
1992年 | 185篇 |
1991年 | 192篇 |
1990年 | 202篇 |
1989年 | 153篇 |
1988年 | 144篇 |
1987年 | 130篇 |
1986年 | 126篇 |
1985年 | 134篇 |
1984年 | 138篇 |
1983年 | 97篇 |
1982年 | 97篇 |
1981年 | 80篇 |
1980年 | 69篇 |
1979年 | 55篇 |
1978年 | 58篇 |
1977年 | 54篇 |
1974年 | 44篇 |
1973年 | 39篇 |
1968年 | 36篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Phyllis Solomon Ph.D. Diane Evans M.S.S.A. Mary Anne Delaney M.D. 《Community mental health journal》1993,29(4):333-346
A majority of a cohort of 62 children and adolescents who had been hospitalized in a state psychiatric facility was found to have received less restrictive services such as outpatient mental health services prior to their index admission. Also, a number had been involved with the juvenile justice system and almost two-thirds had been placed out-of-home. Ninety percent had at least one prior psychiatric hospitalization. Just over half of the cohort received case management and individual counseling post release. About a third received family counseling, and a few received other types of services. At least a third were rehospitalized within a year of release. Although 90% of the cohort received some type of service post release, a higher proportion of non service receivers were rehospitalized than service receivers. Even those who received services had a high rate of rehospitalization. These findings raise questions as to the appropriateness of service provision during and following hospitalization.This study was funded by a grant from the Office of Program Evaluation and Research, Ohio Department of Mental Health. 相似文献
82.
W S Adamus U Jansen J C Schilling 《Methods and findings in experimental and clinical pharmacology》1989,11(1):57-62
1, 4, 12 and 24 micrograms SOM 1397 CL, a new beta 2-adrenergic bronchodilator, were administered by inhalation to 10 healthy volunteers in a double-blind, placebo-controlled, within-subject crossover study in order to assess circulatory, tremorogenic and biochemical effects. 1 microgram SOM 1397 CL did not cause any relevant changes in the measured parameters. After administration of 4 micrograms a slight but continuous increase in tremor amplitude and c-AMP was observed. The effects on hemodynamics and other laboratory values could be considered negligible. Overdoses of 12 and 24 micrograms resulted in a dose-dependent increase in systolic blood pressure, pulse rate, tremor amplitude, alpha-AMP and lactic acid, as well as in a decrease of diastolic blood pressure and potassium. These effects may be partly attributable to beta 2-receptor stimulation. The method described in this paper can be applied as a useful tool for determination of beta 2-adrenergic activity in healthy volunteers, independent of the conventional methods which are used to evaluate efficacy of bronchodilators by the degree of bronchial muscular relaxation. 相似文献
83.
The purpose of this pilot study was to determine the effects of the addition of coping skills training for obese multiethnic parents whose overweight children were attending a weight management program. At 6 months, parents in the experimental group had significantly lower body mass index (BMI) and body fat percentage (BFP) and higher numbers of pedometer steps compared with those in the control group. Parents in the experimental group also demonstrated significant improvement in interpersonal relationships, behavior control, and stress management compared with those in the control group. Children in the experimental group demonstrated trends toward decreased BMI and BFP and increased pedometer steps. 相似文献
84.
R. J. Wechsler Mark E. Schweitzer David Karasick Diane M. Deely William Morrison 《Skeletal radiology》1998,27(1):1-6
Since the degree of comminution, fracture alignment, and articular congruity of intra-articular calcaneal fractures are important
determinants in surgical treatment and patient prognosis, we review helical computed tomographic (CT) technique and features
for detecting and assessing the extent of acute calcaneal fractures. Helical CT can be used to classify these fractures and
facilitate the surgeon’s understanding of the anatomy and position of the fracture components in all orthogonal planes independently
of the patient’s condition, foot placement in the CT gantry, or other injuries. 相似文献
85.
Ira D. Zinner DDS MSD Stanley A. Small DDS † Curtis E. Jansen DDS ‡ Francis V. Panno DDS § 《Journal of prosthodontics》1996,5(3):158-165
Problems that can occur when single implants are utilized to restore first molar teeth include the frequent loosening of screws, as well as screws and/or implant breakage. These may result from torquing and rotational movements of the prosthesis during masticatory and parafunctional mandibular movements. When sufficient bone and mesio-distal restorative space is present, the placement of two implants should be considered. 相似文献
86.
High-capacity in vitro assessment of anti-hepatitis B virus compound selectivity by a virion-specific polymerase chain reaction assay. 总被引:9,自引:6,他引:3 下载免费PDF全文
An integrated assessment system specific for hepatitis B virus (HBV) Dane particle DNA was developed to examine the activity of potential anti-HBV compounds in chronic HBV-producing HepG2-derived 2.2.15 cells. Cell culture, immunoaffinity purification, polymerase chain reaction, and hybrid-capture detection were performed in the microtiter format to facilitate increased throughput by automation. The high sensitivity afforded by the assay provided quantitative detection of less than 0.5 fg of extracellular HBV DNA from 25 microliters of cell culture supernatants, and drug-induced reductions in HBV titers greater than 100-fold were easily measured. Fluorometric determination of total cellular DNA from the same 96-well proliferating cell cultures allowed simultaneous evaluation of inhibition of cell growth, thus providing the ability to assess the overall selectivities of candidate compounds in a single experiment. The potent activities of three anti-HBV compounds, the (+) and (-) enantiomers of cis-5-fluoro-1-[2-(hydroxymethyl)-1,3-oxythiolane-5-yl]cytosine (FTC) and D-carbocyclic-2'-deoxyguanosine (CDG), were confirmed by this method. (-)-FTC was more active than its (+) enantiomer (50% inhibitory concentrations, 0.033 +/- 0.006 and 0.723 +/- 0.160 microM [standard error of the mean; SEM], respectively), while both enantiomers demonstrated a lack of cytotoxicity at 200 microM. CDG was more potent (50% inhibitory concentration, 0.0063 +/- 0.0007 microM [SEM]) but was also significantly more toxic, inhibiting cell growth by 50% at 32 +/- 6 microM (SEM). These results demonstrate the usefulness of this immunoaffinity-based, quantitative polymerase chain reaction system as a high-capacity in vitro tool for assessment of anti-HBV compound selectivity. 相似文献
87.
Rosenberg Leonard S. Hostetler Cheryl K. Wagenknecht Dietmar M. Aunet Diane A. 《Pharmaceutical research》1988,5(8):514-517
Esmolol hydrochloride degrades in aqueous solutions by the hydrolysis of a labile aliphatic carboxy-ester group. The products are methanol and ASL-8123. The resulting aliphatic carboxylic acid moiety (ASL-8123) has a pK of 4.80, which is within 1 pH unit of the pH of the formulation. ASL-8123 therefore acts as a secondary buffer and minimizes the change in pH due to degradation. Equations are presented to calculate the change in the pH when the primary degradation product acts as a secondary buffer. This information can be used in the development of a parenteral product to predict, a priori, the concentration of buffer necessary for optimal pH maintenance. This knowledge can reduce the number of formulation screens required to determine the necessary buffer capacity for optimal drug stability. 相似文献
88.
89.
90.
M. H. de Vries F. A. M. Redegeld A. Sj. Koster J. Noordhoek J. G. de Haan R. P. J. Oude Elferink P. L. M. Jansen 《Naunyn-Schmiedeberg's archives of pharmacology》1989,340(5):588-592
Summary Recently, a mutant rat strain was described with a genetic defect for the biliary excretion of organic anions (TR– rats). To determine the possible heterogeneity of the transport systems in liver, intestine and kidney we investigated the transport of the anion 1-naphthol--d-glucuronide (1-NG) in isolated vascularly perfused organ preparations of the rat liver, intestine and kidney of both Wistar rats and TR– rats. 1-NG was administered as such (liver and kidney experiments) or formed intracellularly from 1-naphthol (1-N) (liver and gut experiments). Independent of the type of exposure to 1-NG, the biliary excretion was considerably impaired in TR– rats. In the intestine the total appearance and the vascular/luminal distribution pattern of 1-NG were not significantly different from the values in control rats. Furthermore, no significant disturbance was found with respect to the renal clearance of 1-NG in the TR– rat when compared with the Wistar rat. Thus, the genetic defect in the TR– rat is restricted to an impaired hepatobiliary excretion of 1-NG and does not affect the excretory systems of the intestine and kidney. These results suggest that the excretion of 1-NG by the liver, intestine and kidney involves distinct organ-specific transport systems. 相似文献