全文获取类型
收费全文 | 1044篇 |
免费 | 81篇 |
出版年
2023年 | 2篇 |
2022年 | 11篇 |
2021年 | 18篇 |
2020年 | 11篇 |
2019年 | 16篇 |
2018年 | 29篇 |
2017年 | 25篇 |
2016年 | 32篇 |
2015年 | 55篇 |
2014年 | 52篇 |
2013年 | 87篇 |
2012年 | 69篇 |
2011年 | 90篇 |
2010年 | 49篇 |
2009年 | 36篇 |
2008年 | 69篇 |
2007年 | 60篇 |
2006年 | 51篇 |
2005年 | 52篇 |
2004年 | 50篇 |
2003年 | 44篇 |
2002年 | 41篇 |
2001年 | 8篇 |
2000年 | 10篇 |
1999年 | 11篇 |
1998年 | 9篇 |
1997年 | 14篇 |
1996年 | 10篇 |
1995年 | 15篇 |
1994年 | 12篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 8篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 7篇 |
1984年 | 9篇 |
1983年 | 4篇 |
1982年 | 10篇 |
1981年 | 4篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1971年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有1125条查询结果,搜索用时 15 毫秒
121.
Cianci A Cicero AF Colacurci N Matarazzo MG De Leo V 《Gynecological endocrinology : the official journal of the International Society of Gynecological Endocrinology》2012,28(9):699-702
The aim of this study was to evaluate the efficacy of a food supplement combination based on isoflavones and berberine (ISB) in the treatment of menopausal symptoms and dyslipidaemia. Isoflavones are extracted from soy and absorbed in the body after being activated by lactobacillus. Berberine, extracted from the plant Berberis aristata, lowers plasma cholesterol and triglycerides (TG) by increasing low-density lipoprotein (LDL) receptors and reducing hepatic synthesis of TG. One hundred twenty women with a mean age of 54.8?±?0.6 years were enrolled and randomized to treatment with ISB (estromineral lipid [EL]?=?60 cases) or calcium and vitamin D(3) (CaD?=?60 cases). Menopausal symptoms, plasma cholesterol, and TG were evaluated at baseline, and after 4 and 12 weeks. EL treatment significantly lowered plasma total cholesterol (-13.5% ± 0.7 vs -0.2% ± 0.5), LDL cholesterol (-12.4% ± 1.5 vs + 0.8 % ± 0.7) and TG (-18.9% ± 2.5 vs -1.3% ± 1.2) and improved menopausal symptoms compared with CaD treatment. Safety parameters were unchanged during the study. The combination of berberine and isoflavones was effective in lowering cardiovascular (CV) risk factors in menopausal women with moderate dyslipidaemia and in improving their quality of life. 相似文献
122.
Casiraghi A Di Grigoli M Cilurzo F Gennari CG Rossoni G Minghetti P 《AAPS PharmSciTech》2012,13(1):247-253
The effect of a homologue series of nonionic surfactants, namely poly(ethylene glycol) (PEG) fatty acid esters, differing
in oxyethylene (PEG 8, PEG 12, and PEG 40) and fatty acid (stearate, mono and di-laurate, and mono and di-oleate) chain lengths,
on in vitro skin permeability of ketoprofen (KTP) vehicled in plasters was investigated. The drug diffusion through hairless mouse skin
as well as the effect of the surfactant type and strength was studied by Franz diffusion cells and ATR-FTIR spectroscopy.
The use of PEG stearate series revealed that the surfactant with the largest polar head, namely PEG 40, was ineffective in
enhancing the skin permeation of KTP, independently of the plaster concentrations. The effect of the hydrophobic chain was
investigated only by using the shortest oxyethylene chains. The experimental results revealed that the oxyethylene chain length
of surfactants appeared to be more influent than the alkyl chain. The prediction of the absorption enhancing capability of
these PEG derivatives appeared related to the vehicle other than the proper combination of the number of ethylene oxide groups
and alkyl groups. 相似文献
123.
Maurizio Callari Matteo Dugo Valeria Musella Edoardo Marchesi Giovanna Chiorino Maurizia Mello Grand Marco Alessandro Pierotti Maria Grazia Daidone Silvana Canevari Loris De Cecco 《PloS one》2012,7(9)
Background
Microarray technology applied to microRNA (miRNA) profiling is a promising tool in many research fields; nevertheless, independent studies characterizing the same pathology have often reported poorly overlapping results. miRNA analysis methods have only recently been systematically compared but only in few cases using clinical samples.Methodology/Principal Findings
We investigated the inter-platform reproducibility of four miRNA microarray platforms (Agilent, Exiqon, Illumina, and Miltenyi), comparing nine paired tumor/normal colon tissues. The most concordant and selected discordant miRNAs were further studied by quantitative RT-PCR. Globally, a poor overlap among differentially expressed miRNAs identified by each platform was found. Nevertheless, for eight miRNAs high agreement in differential expression among the four platforms and comparability to qRT-PCR was observed. Furthermore, most of the miRNA sets identified by each platform are coherently enriched in data from the other platforms and the great majority of colon cancer associated miRNA sets derived from the literature were validated in our data, independently from the platform. Computational integration of miRNA and gene expression profiles suggested that anti-correlated predicted target genes of differentially expressed miRNAs are commonly enriched in cancer-related pathways and in genes involved in glycolysis and nutrient transport.Conclusions
Technical and analytical challenges in measuring miRNAs still remain and further research is required in order to increase consistency between different microarray-based methodologies. However, a better inter-platform agreement was found by looking at miRNA sets instead of single miRNAs and through a miRNAs – gene expression integration approach. 相似文献124.
125.
Giannini G Brunetti T Battistuzzi G Alloatti D Quattrociocchi G Cima MG Merlini L Dallavalle S Cincinelli R Nannei R Vesci L Bucci F Foderà R Guglielmi MB Pisano C Cabri W 《Bioorganic & medicinal chemistry》2012,20(7):2405-2415
Adarotene belongs to the so-called class of atypical retinoids. The presence of the phenolic hydroxyl group on Adarotene structure allows a rapid O-glucuronidation as a major mechanism of elimination of the drug, favoring a fast excretion of its glucuronide metabolite in the urines. A series of ether, carbamate and ester derivatives was synthesized. All of them were studied and evaluated for their stability at different pH. The cytotoxic activity in vitro on NCI-H460 non-small cell lung carcinoma and A2780 ovarian tumor cell lines was also tested. A potential back-up of Adarotene has been selected to be evaluated in tumor models. 相似文献
126.
127.
Ye L Velasco A Fraser G Beach TG Sue L Osredkar T Libri V Spillantini MG Goedert M Lockhart A 《Journal of neurochemistry》2008,105(4):1428-1437
Amyloid containing deposits are a defining neuropathological feature of a wide range of dementias and movement disorders. The positron emission tomography tracer PIB (Pittsburgh Compound-B, 2-[4'-(methylamino)phenyl]-6-hydroxybenzothiazole) was developed to target senile plaques, an amyloid containing pathological hallmark of Alzheimer's disease, formed from the amyloid-beta peptide. Despite the fact that PIB was developed from the pan-amyloid staining dye thioflavin T, no detailed characterisation of its interaction with other amyloid structures has been reported. In this study, we demonstrate the presence of a high affinity binding site (K(d) approximately 4 nM) for benzothiazole derivatives, including [3H]-PIB, on alpha-synuclein (AS) filaments generated in vitro, and further characterise this binding site through the use of radioligand displacement assays employing 4-N-methylamino-4'-hydroxystilbene (SB13) (K(i) = 87 nM) and 2-(1-{6-[(2-fluoroethyl(methyl)amino]-2-naphthyl}ethylidene)malononitrile (FDDNP) (K(i) = 210 nM). Despite the presence of a high-affinity binding site on AS filaments, no discernible interaction of [3H]-PIB was detected with amygdala sections from Parkinson's disease cases containing frequent AS-immunoreactive Lewy bodies and related neurities. These findings suggest that the density and/or accessibility of AS binding sites in vivo are significantly less than those associated with amyloid-beta peptide lesions. Lewy bodies pathology is therefore unlikely to contribute significantly to the retention of PIB in positron emission tomography imaging studies. 相似文献
128.
Marchesi C Belicchi M Meregalli M Farini A Cattaneo A Parolini D Gavina M Porretti L D'Angelo MG Bresolin N Cossu G Torrente Y 《PloS one》2008,3(5):e2218
Background
Various prognostic serum and cellular markers have been identified for many diseases, such as cardiovascular diseases and tumor pathologies. Here we assessed whether the levels of certain stem cells may predict the progression of Duchenne muscular dystrophy (DMD).Methods and Findings
The levels of several subpopulations of circulating stem cells expressing the CD133 antigen were determined by flow cytometry in 70 DMD patients. The correlation between the levels and clinical status was assessed by statistical analysis. The median (±SD) age of the population was 10.66±3.81 (range 3 to 20 years). The levels of CD133+CXCR4+CD34- stem cells were significantly higher in DMD patients compared to healthy controls (mean±standard deviation: 17.38±1.38 vs. 11.0±1.70; P = 0.03) with a tendency towards decreased levels in older patients. Moreover, the levels of this subpopulation of cells correlated with the clinical condition. In a subgroup of 19 DMD patients after 24 months of follow-up, increased levels of CD133+CXCR4+CD34- cells was shown to be associated with a phenotype characterised by slower disease progression. The circulating CD133+CXCR4+CD34- cells in patients from different ages did not exhibit significant differences in their myogenic and endothelial in vitro differentiation capacity.Conclusions
Our results suggest that levels of CD133+CXCR4+CD34- could function as a new prognostic clinical marker for the progression of DMD. 相似文献129.
130.
de Koning-Ward TF Olivieri A Bertuccini L Hood A Silvestrini F Charvalias K Berzosa Díaz P Camarda G McElwain TF Papenfuss T Healer J Baldassarri L Crabb BS Alano P Ranford-Cartwright LC 《Molecular microbiology》2008,67(2):278-290
Osmiophilic bodies are membrane-bound vesicles, found predominantly in Plasmodium female gametocytes, that become progressively more abundant as the gametocyte reaches full maturity. These vesicles lie beneath the subpellicular membrane of the gametocyte, and the release of their contents into the parasitophorous vacuole has been postulated to aid in the escape of gametocytes from the erythrocyte after ingestion by the mosquito. Currently, the only protein known to be associated with osmiophilic bodies in Plasmodium falciparum is Pfg377, a gametocyte-specific protein expressed at the onset of osmiophilic body development. Here we show by targeted gene disruption that Pfg377 plays a fundamental role in the formation of these organelles, and that female gametocytes lacking the full complement of osmiophilic bodies are significantly less efficient both in vitro and in vivo in their emergence from the erythrocytes upon induction of gametogenesis, a process whose timing is critical for fertilization with the short-lived male gamete. This reduced efficiency of emergence explains the significant defect in oocyst formation in mosquitoes fed blood meals containing Pfg377-negative gametocytes, resulting in an almost complete blockade of infection. 相似文献