全文获取类型
收费全文 | 3683篇 |
免费 | 229篇 |
国内免费 | 121篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 32篇 |
妇产科学 | 227篇 |
基础医学 | 297篇 |
口腔科学 | 45篇 |
临床医学 | 174篇 |
内科学 | 193篇 |
皮肤病学 | 68篇 |
神经病学 | 195篇 |
特种医学 | 47篇 |
外科学 | 237篇 |
综合类 | 391篇 |
预防医学 | 290篇 |
眼科学 | 29篇 |
药学 | 1250篇 |
1篇 | |
中国医学 | 312篇 |
肿瘤学 | 236篇 |
出版年
2024年 | 7篇 |
2023年 | 28篇 |
2022年 | 55篇 |
2021年 | 74篇 |
2020年 | 71篇 |
2019年 | 72篇 |
2018年 | 106篇 |
2017年 | 99篇 |
2016年 | 84篇 |
2015年 | 96篇 |
2014年 | 217篇 |
2013年 | 299篇 |
2012年 | 155篇 |
2011年 | 213篇 |
2010年 | 163篇 |
2009年 | 160篇 |
2008年 | 174篇 |
2007年 | 197篇 |
2006年 | 165篇 |
2005年 | 153篇 |
2004年 | 138篇 |
2003年 | 112篇 |
2002年 | 110篇 |
2001年 | 77篇 |
2000年 | 79篇 |
1999年 | 61篇 |
1998年 | 49篇 |
1997年 | 61篇 |
1996年 | 51篇 |
1995年 | 54篇 |
1994年 | 57篇 |
1993年 | 50篇 |
1992年 | 51篇 |
1991年 | 46篇 |
1990年 | 36篇 |
1989年 | 33篇 |
1988年 | 35篇 |
1987年 | 38篇 |
1986年 | 30篇 |
1985年 | 56篇 |
1984年 | 38篇 |
1983年 | 24篇 |
1982年 | 39篇 |
1981年 | 24篇 |
1980年 | 19篇 |
1979年 | 19篇 |
1978年 | 20篇 |
1977年 | 16篇 |
1975年 | 7篇 |
1974年 | 6篇 |
排序方式: 共有4033条查询结果,搜索用时 31 毫秒
81.
目的:建立复方醋酸氯己定洗剂的含量测定方法.方法:采用高效液相色谱法,μBndapak-C18柱(5μm,250 mm×3.9 mm);流动相为乙腈-甲醇-水(21:37:42),每1000ml内含磷酸5ml,三氟乙酸1 ml,三乙胺调pH3.9~4.0;流速为1 ml·min-1;检测波长为230 nm.结果:醋酸氯己定和克霉唑分别在10~125μg·m1和2~25 μg·ml-1范围内线性关系良好;平均回收率分别为95.6%及96.5%(RSD 1.2%,1.5%).结论:本法色谱分离效率高,专属性好,同时测定两种成份,方法简便. 相似文献
82.
Fernando Tecles Asta Tvarijonaviciute Carlos De Torre José M. Carrillo Mónica Rubio Montserrat García 《Scandinavian journal of clinical and laboratory investigation》2016,76(4):324-330
Although saliva has esterase activity, this activity has not been characterized or studied in individuals subjected to physical stress. The aim of this report was to develop and validate an automated spectrophotometric assay for total esterase activity measurement in human saliva, as well as to study the contribution of different enzymes on this activity and its behaviour under physical stress in healthy subjects. The assay used 4-nitrophenyl acetate as substrate and was precise, accurate and provided low limits of detection and quantification. Inhibition with diisopropylfluorophosphate showed that cholinesterase, carboxylesterase and cholesterol esterase contributions not represented more than 20% of total esterase. Addition of standards of lipase and albumin to saliva samples showed that both proteins significantly contributed to esterase activity only when equal or higher than 11.6?IU/L and 250?μg/mL, respectively. Western blot analyses showed absence of paraoxonase-1 and high amount of carbonic anhydrase-VI. The high affinity of purified carbonic anhydrase-VI for the substrate supported a major contribution of this enzyme. Total esterase activity and alpha-amylase was measured in saliva samples from 12 healthy male students before and after participation in an indoor football match. The activity significantly increased after match and positively correlated with salivary alpha-amylase. This method could be used as a biomarker of physical stress in humans, with carbonic anhydrase-VI being the esterase that contributed more to the activity of the assay. 相似文献
83.
《Expert opinion on pharmacotherapy》2013,14(7):1225-1230
The first sign of developing multiple sclerosis is a clinically isolated syndrome that resembles a multiple sclerosis relapse. Objective/methods: The objective was to review the clinical trials of two medicines in clinically isolated syndromes (interferon β and glatiramer acetate) to determine whether they prevent progression to definite multiple sclerosis. In the BENEFIT trial, after 2 years, 45% of subjects in the placebo group developed clinically definite multiple sclerosis; the rate was lower in the interferon β-1b group. All subjects were then offered interferon β-1b, and the original interferon β-1b group became the early-treatment group and the placebo group became the delayed-treatment group. After 5 years, the number of subjects with clinical definite multiple sclerosis remained lower in the early-treatment than in the late-treatment group. In the PreCISe trial, after 2 years, the time for 25% of the subjects to convert to definite multiple sclerosis was prolonged in the glatiramer group. Interferon β-1b and glatiramer acetate slow the progression of clinically isolated syndromes to definite multiple sclerosis. However, it is not known whether this early treatment slows the progression to the physical disabilities experienced in multiple sclerosis. 相似文献
84.
85.
With the goal of developing soluble epoxide hydrolase (sEH) inhibitors with novel chemical structures, the sEH inhibitory activities of 30 natural compounds were evaluated using both a fluorescent substrate, 3-phenyl-cyano(6-methoxy-2-naphthalenyl)methyl ester- 2-oxiraneacetic acid, and a physiological substrate, 14,15-epoxyeicosatrienoic acid. To evaluate the selectivity of sEH inhibition, the inhibition of microsomal epoxide hydrolase (mEH), which plays a critical role in detoxification of toxic epoxides, was determined using human liver microsomes. Honokiol and β-amyrin acetate, isolated from Magnolia officinalis and Acer mandshuricum, respectively, displayed strong inhibition of sEH activity, with respective IC50 values of 0.57 μM and 3.4 μM determined using the fluorescent substrate, and 1.7 μM and 6.1 μM determined using 14,15-epoxyeicosatrienoic acid. mEH activity was decreased to 49% or 61% of control activity by 25 μM honokiol or β-amyrin acetate, respectively. These results suggest that β-amyrin acetate and honokiol exhibit sEH inhibitory activity, although their sEH selectivity should be improved. 相似文献
86.
BackgroundAbiraterone (ABI) is a major oral agent for the treatment of metastatic castration-resistant prostate cancer (mCRPC) patients but its systemic exposure is subject to a large inter-individual variability. We aimed to explore the relationship between ABI trough plasma concentration and prostate-specific antigen (PSA) response in mCRPC patients and to identify the critical determinants for its activity.Patients and methodsThis is a monocentric prospective observational study in mCRPC patients treated with ABI. The plasmatic concentration of ABI at steady state was measured using liquid chromatography with fluorescence detection. The primary objective was to study the relationship between mean ABI plasma exposure (ABI Cmin) and 3-month PSA response.ResultsFrom 2012 to 2016, 61 mCRPC patients were eligible for pharmacokinetic/pharmacodynamic assessment. Thirty-eight patients experienced PSA response (62%, [confidence interval {CI} 95% 50–78]). In univariate analysis, ABI Cmin was 1.5-fold higher in responders: 12.0 ng/mL (CI 95% 9.4–15.6) versus 8.0 ng/mL (CI 95% 5.8–11.6; P = 0.0015). In multivariate analysis, only ABI Cmin was independently associated with PSA response (odds ratio = 1.12 [CI 95% 1.01–1.25], P = 0.004). By receiver operating characteristic analysis, the optimal threshold for ABI Cmin was 8.4 ng/mL. Progression-free survival (PFS) was significantly higher in patients with ABI Cmin above 8.4 ng/mL (hazard ratio 0.55, [CI 95% 0.31–0.99], 12.2 [CI 95% 9.2–19.5] versus 7.4 [CI 95% 5.5–14.7] months otherwise, P = 0.044).ConclusionsWe showed that ABI trough concentration correlates with PSA response and PFS. Moreover, we could determine a cut-off value of plasmatic concentration for PSA response. Altogether, ABI concentration monitoring appears as a new approach to improve clinical outcome in mCPRC patients. 相似文献
87.
The objective of this work was to develop uniformly distributed poly(ethylene glycol) grafted poly(lactide-co-glycolide) (PEG-PLGA) nanoparticles of mean size range ~100–200 nm using ethyl acetate as the solvent. In the multiple emulsion solvent evaporation method a high pressure microfluidization process was adopted to produce the W/O/W multiple emulsion. Non-toxic ethyl acetate was used to solubilize PEG-PLGA. The mean size of nanoparticles obtained was less than 180 nm. The particle size and size distribution were dependent on the microfluidization conditions applied. Mean particle size steadily increased from 121 nm at three passes to 172 nm at 20 passes of the microfluidizer, indicating that over-processing may be detrimental to PEG-PLGA nanoparticles prepared using this technique. There was no significant alteration of the PEG-PLGA matrix, as evidenced from the differential scanning calorimetric studies. 相似文献
88.
Progestin‐primed ovarian stimulation with or without clomiphene citrate supplementation in normal ovulatory women undergoing in vitro fertilization/intracytoplasmic sperm injection: A prospective randomized controlled trial
下载免费PDF全文
![点击此处可从《Clinical endocrinology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
89.
90.
《Journal of drug targeting》2013,21(6):487-492
AbstractThe effects of concentration, amperage and duration on the antidiuretic response induced by iontophoretic delivery of desmopressin acetate (DDAVP) were examined using a diabetes insipidus model in rats. A higher current density brought about a larger and longer antidiuretic response. Prolonged iontophoretic duration caused an overdose. Repeated short iontophoretic treatments with lower current density maintained a constant response with a short lag time and a rapid disappearance of pharmacological response immediately after cessation of the final treatment. This type of iontophoresis substantially reduced the inter-subject variability of response as compared to the response using an intranasal route of administration. 相似文献