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991.
液相色谱-串联质谱法测定比格犬血浆中淫羊藿苷元   总被引:1,自引:0,他引:1       下载免费PDF全文
目的:建立了测定比格犬血浆中淫羊藿苷元浓度的液相色谱-串联质谱法(LC-MS/MS)。方法:血浆样品经酶水解,用液-液萃取法,以乙酸乙酯提取后,以乙腈-5%乙酸(70∶30)为流动相,用Zorbax C8柱分离,流速为0.6 mL.min-1,通过电喷雾离子化四极杆串联质谱,以多反应监测方式(MRM)进行检测。用于定量分析的离子分别为m/z369/313(淫羊藿苷元)和m/z331/315(麦黄酮,内标)。结果:淫羊藿苷元在比格犬血浆浓度测定方法的线性范围为2.5~250 ng.mL-1;日内、日间精密度(RSD)均小于13.3%,准确度(RE)在±5.5%之内。在临床前药动学研究中,应用此法测试了比格犬口服给药后的血药浓度。结论:本方法灵敏度高、专属性强,适合于淫羊藿苷元的临床前药动学研究。  相似文献   
992.
Azaspiracids are a family of lipophilic polyether marine biotoxins that have caused a number of human intoxication incidents in Europe since 1995 following the consumption by consumers of intoxicated shellfish (Mytilus edulis). These azaspiracids have now been identified in mussels (Mytilus chilensis) and scallops (Argopecten purpuratus) from two Chilean locations. This is the first report of the occurrence of azaspiracid toxins in these species (Mytilus chilensis and Argopecten purpuratus) from Chile. The areas studied were Bahía Inglesa (III Region, 27° SL) and Chiloé Archipelago, both important scallop and mussels farming areas. Separation of azaspiracid (AZA1), azaspiracid isomer (AZA6) and its analogues, 8-methylazaspiracid (AZA2) and 22-demethylazaspiracid (AZA3), was achieved using reversed-phase LC and toxins were identified using a turbo electrospray ionisation (ESI) source, to a triple quadrupole mass spectrometer.In mussels, AZA1 was the predominant toxin in mussel hepatopancreas with AZA2, AZA3 and AZA6 present in approximate equivalent amounts in the remaining tissues, 20-30% of the AZA1 level. AZA2 predominated in the scallop samples with the toxin almost entirely present in the hepatopancreas (digestive gland). AZA1 was only observed in some of the scallop samples and was present at 12-15% of the AZA2 levels.Whilst the levels of AZAs in Chilean samples are below the EU regulatory limit of 160 μg/kg, it is significant that this toxin is present in Pacific Ocean species. Consequently measures should be taken by regulatory authorities to implement regular seafood monitoring to ensure safety of harvested product.  相似文献   
993.
Mango is one of the important tropical fruits in the world. As it is a seasonal fruit, it is processed for various products. During its processing, peel is one of the major byproducts, which is being wasted. Bioactive conserves were extracted using 80% acetone from peels of raw and ripe mango fruits and subjected to acid hydrolysis. The prominent phenolic compounds identified by HPLC were protocatechuic acid, gentisic acid and gallic acid. The phenolic acid derivatives present in acetone extracts of raw and ripe peels were tentatively identified by LC–MS. Gallic acid, syringic acid, mangiferin, ellagic acid, gentisyl-protocatechuic acid, quercetin were the phenolic compounds identified in both raw and ripe peels, while raw peel showed the presence of glycosylated iriflophenone and maclurin derivatives also. β-Carotene was the major carotenoid followed by violaxanthin and lutein. Thus, both raw and ripe mango peel extracts have different phenolic compounds and carotenoids, which will have various pharmaceutical applications.  相似文献   
994.
1. A simple and sensitive liquid chromatography–tandem mass spectrometry (LC‐MS‐MS) method for quantifying trimetazidine in human plasma was developed and validated. Sample preparation was based on deproteinating with acetonitrile. 2. Chromatography was performed on a C18 analytical column (5 μm; 150 × 2.1 mm i.d.) and the retention times for trimetazidine and cetirizine (used as the internal standard) were 1.8 and 3.0 min, respectively. The ionization was optimized using an electrospray ionization source and enhanced selectivity was achieved using tandem mass spectrometry. The calibration curve ranged from 0.1 to 200 ng/mL. The inter‐day precision, accuracy and the relative standard deviation (RSD) were all < 15%. The analyte was shown to be stable over the time‐scale of the entire procedure. 3. The robustness of the method was demonstrated by the good reproducibility of the results obtained during the analysis of clinical samples.  相似文献   
995.
Contamination of shellfish from the Portuguese coast with diarrhetic shellfish poisoning (DSP) toxins is a recurrent event, with most of the commercial bivalves contaminated with high percentages of esters of okadaic acid (OA) and dinophysistoxin‐2 (DTX2). This report describes the quantification of DSP toxins in unhydrolysed and hydrolysed extracts of several cockle and mussel samples naturally contaminated and the evaluation of their cytotoxicity profiles in V79 cells. The quantification of the acyl esters in the shellfish samples involved the cleavage of the ester bond through alkaline hydrolysis and the release of the parent toxins OA and DTX2. Unhydrolysed and hydrolysed extracts were then analyzed by liquid chromatography (LC) coupled with mass spectrometry (MS) for the detection and quantification of DSP toxins. The cytotoxicity of the analysed extracts was evaluated using the MTT reduction assay and compared with the cytotoxicity presented by different concentrations of OA standard (1–100 nm ). OA exhibited marked cytotoxic effects and decreased cell viability in a dose dependent mode, with an IC50 of 27 nm . The cytotoxicity pattern of unhydrolysed extracts was clearly dependent on the concentration of free toxins. Moreover, the cytotoxicity of the esterified toxins present was revealed after their conversion into free toxins by alkaline hydrolysis. For the hydrolysed extracts of cockles and mussels, the cytotoxicity presented was mainly related to the concentration of OA and DTX2. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
996.
液质联用研究CHO-K1细胞对巴氯酚的摄取   总被引:1,自引:0,他引:1  
目的:通过细胞摄取巴氯酚的体外药动学研究及液质联用定量检测方法的建立,为确定巴氯酚更合理的给药途径和跨越血脑屏障的机制研究提供依据。方法:利用CHO-K1细胞摄取药物的细胞生物学实验方法结合液质联用检测技术,以细胞/介质(cell/medium,C/M)比值为指标进行CHO-K1细胞摄取巴氯酚体外药动学研究,并进行方法学考察。本实验选取的摄取时间点分别为30s,1,5,30,60min。结果:液质联用定量方法灵敏度高,重复性好。在0~30min区间内,细胞摄取巴氯酚的量随时间几乎呈线性增加,30min时的C/M值达到最高为9.74(n=4),基本达到饱和状态,30~60min区间,细胞摄取巴氯酚的量几乎不再随时间发生变化。结论:为深入研究巴氯酚跨越血脑屏障的机制并确定实际应用的给药途径提供数据基础和参考依据。定量方法简便快捷,灵敏度高,重复性好,可广泛应用于细胞摄取微量药物的检测研究中,具实用价值。  相似文献   
997.
目的:建立快速测定人尿中帕洛诺司琼浓度的高效液相色谱串联质谱电喷雾检测法(LC-ESI-MS/MS)。方法:以AgilentTCC18柱(4.6mm×150mm,5μm)为色谱柱;流动相为乙腈-0.04mol.L-1甲酸铵水溶液(含0.04%甲酸)(69∶31),流速0.6mL·min-1;柱温25℃;醋酸乙酯-二氯甲烷(4∶1)为提取剂。样品经电喷雾离子源正离子化后,样品通过三重四级杆串联质谱仪,采用选择反应监测(SRM)对帕洛诺司琼(m/z297.2→82.2)和内标地西泮(m/z285.1→154.0)测定。结果:帕洛诺司琼高(80μg.L-1)、中(50μg.L-1)、低(5μg.L-1)3个浓度的平均回收率RSD均小于15%;线性范围为2.5~100μg.L-1,回归方程为F=27.135ρ-0.0582,r=0.9999(n=6),权重系数为1/ρ,分析方法的最低定量限为2.5μg.L-1。结论:该方法灵敏、准确、简单、快速,可用于帕洛诺司琼临床尿药浓度监测和药动学研究。  相似文献   
998.
999.

Background

Vitamin D status (VDS) has been linked to mortality and incident acute myocardial infarction (AMI) in healthy cohorts. Associations with recurrent adverse cardiovascular events in those with cardiovascular disease are less clear. Our objective was to assess the prevalence and prognostic impact of VDS on patients presenting with AMI.

Methods

We measured plasma 25-(OH)D3 and 25-(OH)D2 using isotope dilution tandem mass spectrometry, in 1259 AMI patients (908 men, mean age 65.7 ± 12.8 years). The primary endpoint was major adverse events (MACE), a composite of death (n = 141), heart failure hospitalisation (n = 111) and recurrent AMI (n = 147) over median follow-up of 550 days (range 131–1095). Secondary endpoints were fatal and non-fatal MACE.

Results

Almost 74% of the patients were vitamin D deficient (< 20 ng/ml 25-(OH)D). Plasma 25-(OH)D existed mainly as 25-(OH)D3 which varied with month of recruitment. Multivariable survival Cox regression models stratified by recruitment month (adjusted for age, gender, past history of AMI/angina, hypertension, diabetes, hypercholesterolaemia, ECG ST change, Killip class, eGFR, smoking, plasma NTproBNP), showed 25-(OH)D3 quartile as an independent predictor of MACE(P < 0.001) and non-fatal MACE(P < 0.01), but not death. Using the lowest 25-(OH)D3 quartile(< 7.3 ng/ml) as reference for MACE prediction, the 2nd, 3rd and 4th quartiles showed significantly lower hazard ratios (HR 0.59(P < 0.002), 0.58(P < 0.001), and 0.59(P < 0.003) respectively). For non-fatal MACE prediction, the 2nd, 3rd and 4th 25-(OH)D3 quartiles were all significantly different from the lowest reference quartile (HR 0.69(P < 0.05), 0.54(P < 0.003) and 0.59(P < 0.014) respectively).

Conclusions

VDS is prognostic for MACE (predominantly non-fatal MACE) post-AMI, with approximate 40% risk reduction for 25-(OH)D3 levels above 7.3 ng/ml.  相似文献   
1000.
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