全文获取类型
收费全文 | 151篇 |
免费 | 7篇 |
出版年
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 1篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 2篇 |
2013年 | 4篇 |
2012年 | 9篇 |
2011年 | 11篇 |
2010年 | 9篇 |
2009年 | 6篇 |
2008年 | 7篇 |
2007年 | 10篇 |
2006年 | 6篇 |
2005年 | 3篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 14篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1972年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有158条查询结果,搜索用时 31 毫秒
111.
112.
Susanne G. L. Quaak John B. A. G. Haanen Jos H. Beijnen Bastiaan Nuijen 《AAPS PharmSciTech》2010,11(1):344-350
Since plasmid DNA (pDNA) is unstable in solution, lyophilisation can be used to increase product shelf life. To prevent stress
on pDNA molecules during lyophilisation, cryo- and lyoprotectants have to be added to the formulation. This study assessed
the effect of disaccharides on naked pDNA stability after lyophilisation using accelerated stability studies. Naked pDNA was
lyophilised with sucrose, trehalose, maltose or lactose in an excipient/DNA w/w ratio of 20. To one part of the vials extra residual moisture was introduced by placing the vials half opened in a 25°C/60%
RH climate chamber, before placing all vials in climate chambers (25°C/60% RH and 40°C/75% RH) for stability studies. An ex vivo human skin model was used to assess the effect of disaccharides on transfection efficiency. Lyophilisation resulted in amorphous
cakes for all disaccharides with a residual water content of 0.8% w/w. Storage at 40°C/75% RH resulted in decreasing supercoiled (SC) purity levels (sucrose and trehalose maintained approximately
80% SC purity), but not in physical collapse. The addition of residual moisture (values between 7.5% and 10% w/w) resulted in rapid collapse except for trehalose and decreasing SC purity for all formulations. In a separate experiment
disaccharide formulation solutions show a slight but significant reduction (<3% with sucrose and maltose) in transfection
efficiency when compared to pDNA dissolved in water. We demonstrate that disaccharides, like sucrose and trehalose, are effective
lyoprotectants for naked pDNA. 相似文献
113.
Robert S. Jansen Hilde Rosing Wiete Kromdijk Rob ter Heine Jan HM Schellens Jos H. Beijnen 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2010,878(7-8):621-627
Emtricitabine (FTC) and tenofovir (TFV) are widely used antiviral agents that require intracellular phosphorylation to become active. This article describes the development and validation of an assay for the simultaneous quantification of FTC mono-, di- and triphosphate (FTC-MP, -DP and -TP), TFV and TFV mono- and diphosphate (TFV-MP and -DP) in peripheral blood mononuclear cells. Reference compounds and internal standards were obtained by thermal degradation of FTC-TP, TFV-DP, stable isotope-labeled TFV-DP and stable isotope-labeled cytosine triphosphate. Cells were lysed in methanol:water (70:30, v/v) and the extracted nucleotides were analyzed using weak anion-exchange chromatography coupled with tandem mass spectrometry. Calibration ranges in PBMC lysate from 0.727 to 36.4, 1.33 to 66.4 and 1.29 to 64.6 nM for FTC-MP, FTC-DP and FTC-TP and from 1.51 to 75.6, 1.54 to 77.2 and 2.54 to 127 nM for TFV, TFV-MP and TFV-DP, respectively, were validated. Accuracies were within ?10.3 and 16.7% deviation at the lower limit of quantification at which the coefficients of variation were less than 18.2%. At the other tested levels accuracies were within ?14.3 and 9.81% deviation and the coefficients of variation lower than 14.7%. The stability of the compounds was assessed under various analytically relevant conditions. The method was successfully applied to clinical samples. 相似文献
114.
G.P. Kaijser J.H. Beijnen E.L. Jeunink A. Bult H.J. Keizer J. de Kraker W.J.M. Underberg 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1993,614(2)
A derivatization high-performance liquid chromatographic method with ultraviolet detection to monitor the plasma concentration of chloroacetaldehyde, a neurotoxic metabolite of oxazaphosphorine drugs, is presented. To prevent the rapid degradation of chloroacetaldehyde, the plasma samples are stabilized with formaldehyde. The method is linear in the concentration range 1–250 nmol/ml. Blood samples from a patient who was treated with a ten-day continuous infusion of ifosfamide were assayed. The chloroacetaldehyde concentrations did not exceed 10 nmol/ml. 相似文献
115.
Bart A.W. Jacobs Dick Pluim Pia van der Laan Anna Tzani Jos H. Beijnen 《Nucleosides, nucleotides & nucleic acids》2013,32(8):436-454
AbstractThe enzyme thymidine phosphorylase (TP) is important for activation of capecitabine and 5-fluorouracil. Assessment of TP phenotype might be suitable for identification of patients at risk of fluoropyrimidine-induced toxicity. In this paper, we describe the development and validation an assay for TP activity in peripheral blood mononuclear cells (PBMCs). The assay was based on ex vivo conversion of the TP substrate thymidine to thymine. The amount of thymine formed was determined by high-performance liquid chromatography – ultraviolet detection (HPLC-UV) with 5-bromouracil as internal standard. Lymphocytes and monocytes were purified from isolated PBMCs to examine cell-specific TP activity. TP activity in PBMCs demonstrated Michaelis-Menten kinetics. The lower limit of quantification was 2.3?µg PBMC protein and assay linearity was demonstrated up to 22.7?µg PBMC protein. Within-day and between-day precisions were ≤9.2% and ≤6.0%, respectively. Adequate stability TP activity was demonstrated after long-term storage of PBMC dry pellets and lysates at ?80?°C. In monocytes, TP activity was approximately 3 times higher than in lymphocytes. Clinical applicability was demonstrated in samples that were collected from five cancer patients. A simple, precise and sensitive HPLC-UV assay for quantification of TP activity in PBMCs was developed that can be applied for clinical research. 相似文献
116.
Ponnulakshmi Rajagopal Selvaraj Jayaraman Shazia Fathima JH Saravanan Radhakrishnan Patil Ashlesh Laxman Vijaya Prakash Krishnan Muthaiah Satyendra Chandra Tripathi TS Gugapriya Aaditya Madhusudan Tarnekar Gayatri Girish Muthiyan Vishwajit Ravindra Deshmukh Bharat Ramrao Sontakke Kirubhanand Chandrashekar 《Bioinformation》2021,17(11):928
117.
Chella Perumal Palanisamy Shazia Fathima JH Ramya Sekar Ponnulakshmi Rajagopal Selvaraj Jeyaraman 《Bioinformation》2021,17(7):705
It is of interest to document the inhibition of A2780 cell proliferation using Mollugo nudicaulis Lam.(M.nudicaulis) extract by MTT assay and by monitoring the CXCR4 and HER2 expression through RT-PCR analysis. Results shown that the n-hexane extract of M.nudicaulis have anticancer activity IC50 values of 32.46±0.92 µg/mL on A2780 cell lines. It is further found that the CXCR4 and HER2 mRNA and protein expression were significantly reduced in M.nudicaulis treated A2780 cell lines. Thus, the n-hexane extract of M.nudicaulis is a natural source of bioactive compounds as potential anticancer agents. 相似文献
118.
Inès J Goossens-Beumer Jan Oosting Wim E Corver Marjolein JFW Janssen Bart Janssen Wilbert van Workum Eliane CM Zeestraten Cornelis JH van de Velde Hans Morreau Peter JK Kuppen Tom van Wezel 《BMC genomics》2015,16(1)
Background
In rectal cancer, total mesorectal excision surgery combined with preoperative (chemo)radiotherapy reduces local recurrence rates but does not improve overall patient survival, a result that may be due to the harmful side effects and/or co-morbidity of preoperative treatment. New biomarkers are needed to facilitate identification of rectal cancer patients at high risk for local recurrent disease. This would allow for preoperative (chemo)radiotherapy to be restricted to high-risk patients, thereby reducing overtreatment and allowing personalized treatment protocols. We analyzed genome-wide DNA copy number (CN) and allelic alterations in 112 tumors from preoperatively untreated rectal cancer patients. Sixty-six patients with local and/or distant recurrent disease were compared to matched controls without recurrence. Results were validated in a second cohort of tumors from 95 matched rectal cancer patients. Additionally, we performed a meta-analysis that included 42 studies reporting on CN alterations in colorectal cancer and compared results to our own data.Results
The genomic profiles in our study were comparable to other rectal cancer studies. Results of the meta-analysis supported the hypothesis that colon cancer and rectal cancer may be distinct disease entities. In our discovery patient study cohort, allelic retention of chromosome 7 was significantly associated with local recurrent disease. Data from the validation cohort were supportive, albeit not statistically significant, of this finding.Conclusions
We showed that retention of heterozygosity on chromosome 7 may be associated with local recurrence in rectal cancer. Further research is warranted to elucidate the mechanisms and effect of retention of chromosome 7 on the development of local recurrent disease in rectal cancer.Electronic supplementary material
The online version of this article (doi:10.1186/s12864-015-1550-0) contains supplementary material, which is available to authorized users. 相似文献119.
Katharine M Hardy Tatiana A Yatskievych JH Konieczka Alexander S Bobbs Parker B Antin 《BMC developmental biology》2011,11(1):20
Background
FGF signalling regulates numerous aspects of early embryo development. During gastrulation in amniotes, epiblast cells undergo an epithelial to mesenchymal transition (EMT) in the primitive streak to form the mesoderm and endoderm. In mice lacking FGFR1, epiblast cells in the primitive streak fail to downregulate E-cadherin and undergo EMT, and cell migration is inhibited. This study investigated how FGF signalling regulates cell movement and gene expression in the primitive streak of chicken embryos. 相似文献120.
Sparidans RW Martens I Valkenburg-van Iersel LB den Hartigh J Schellens JH Beijnen JH 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2011,879(21):1851-1856
A bioanalytical assay for the new poly(ADP-ribose) polymerase-1 inhibitor olaparib in combination with melphalan was developed and validated. For the quantitative assay, human plasma samples were pre-treated on ice using protein precipitation with 2% (v/v) acetic acid in acetonitrile containing erlotinib and melphalan-d? as internal standards. The extract was diluted with water and injected into the chromatographic system. This system consisted of a sub-2 μm particle, trifunctional bonded octadecyl silica column with an isocratic elution using 0.01% (v/v) of formic acid in a mixture of water and methanol. The eluate was transferred into the electrospray interface with positive ionization and the analyte was detected in the selected reaction monitoring mode of a triple quadrupole mass spectrometer. The assay was validated in a 10-5000 ng/ml calibration range for both drugs. The lowest level of this range corresponded to the lower limit of quantification. Within day precisions were 3.0-9.3%, between day precisions 6.0-9.8% and accuracies were between 101 and 110% for the whole calibration range. After validation the assay was used to assess the pharmacokinetics of olaparib in a patient with metastatic breast carcinoma. In addition, systemic exposure of melphalan was monitored in patients subjected to isolated hepatic perfusion with this drug. Both applications show that the new assay can be applied for human pharmacokinetic studies for both drugs. 相似文献