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排序方式: 共有383条查询结果,搜索用时 109 毫秒
101.
Brett C. McWhinney Scott E. BriscoeJacobus P.J. Ungerer Carel J. Pretorius 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2010,878(28):2863-2869
We describe an ultra high performance liquid chromatography–tandem mass spectrometry (UHPLC MS/MS) method suitable for a routine laboratory to determine endogenous and exogenous glucocorticoids in plasma, plasma ultrafiltrate, urine and saliva in a single analytical run. After addition of a multi-analyte internal standard, a standardised sample preparation procedure with solid phase extraction followed, before injecting into a tandem mass spectrometer with positive mode electron spray ionisation and multiple reactant monitoring acquisition. The chromatography time was 3 min. The limit of quantitation for cortisol and cortisone in plasma was 3.75 nmol/L and linearity extended to 2000 nmol/L. The limit of quantitation for cortisol in plasma ultrafiltrate and saliva was 0.6 nmol/L. The limit of quantitation for 11-deoxycortisol and prednisolone was 5 nmol/L and for dexamethasone 1 nmol/L. The intra-assay CV was <5% and the inter-assay CV <10% for all analytes in all matrices. Comparison with an immuno-assay (IA) plasma cortisol method resulted in a regression equation of UHPLC = 0.79 × IA + 31.12 with R2 = 0.960 (p < 0.0001). Comparison with a high performance liquid chromatography (HPLC) cortisol method yielded a regression equation of UHPLC = 1.06 × HPLC + 9.82, R2 = 0.992 (p < 0.0001). The simultaneous measurement of endogenous and exogenous glucocorticoids contributed to patient care in cases with dexamethasone and metyrapone dynamic tests and unsuspected therapeutic glucocorticoid use. 相似文献
102.
Abstract Palladium catalyzed carboxyamidation at the 8-position of 8-bromoadenosine and 8-bromoguanosine nucleosides is a versatile reaction, which allows primary, secondary, heterocyclic, aromatic mine and amino acids to be incorporated into purine nucleosides. 相似文献
103.
104.
Cox MA Gomes B Palmer K Du K Wiekowski M Wilburn B Petro M Chou CC Desquitado C Schwarz M Lunn C Lundell D Narula SK Zavodny PJ Jenh CH 《Biochemical and biophysical research communications》2005,330(2):467-473
The human P2Y6 receptor (hP2Y6) is a member of the G protein-coupled pyrimidinergic P2 receptor family that responds specifically to the extracellular nucleotide uridine diphosphate (UDP). Recently, the hP2Y6 receptor has been reported to mediate monocyte IL-8 production in response to UDP or lipopolysaccharide (LPS), but the role of hP2Y6 in regulating other pro-inflammatory cytokines or mediators is largely unknown. We demonstrate here that UDP specifically induces soluble TNF-alpha and IL-8 production in a promonocytic U937 cell line stably transfected with hP2Y6. However, we did not detect IL-1alpha, IL-1beta, IL-6, IL-10, IL-18, and PGE2 in the conditioned media from the same cell line. These results distinguish UDP/P2Y6 signaling from LPS signaling. Interestingly, UDP induces the production of IL-8, but not TNF-alpha, in human astrocytoma 1321N1 cell lines stably transfected with hP2Y6. Therefore, the immune effect of UDP/P2Y6 signaling on the production of proinflammatory cytokines is selective and dependent on cell types. We further identify that UDP can also induce the production of proinflammatory chemokines MCP-1 and IP-10 in hP2Y6 transfected promonocytic U937 cell lines, but not astrocytoma 1321N1 cell lines stably transfected with hP2Y6. From the Taqman analysis, UDP stimulation significantly upregulates the mRNA levels of IL-8, IP-10, and IL-1beta, but not TNF-alpha. Taken together, these new findings expand the pro-inflammatory biology of UDP mediated by the P2Y6 receptor. 相似文献
105.
McWhinney C Wenham D Kanwal S Kalman V Hansen C Robishaw JD 《The Journal of biological chemistry》2000,275(3):2087-2097
Activation of alpha(1)-adrenergic receptors influences both the contractile activity and the growth potential of cardiac myocytes. However, the signaling pathways linking activation of specific alpha(1)-adrenergic receptor (AR) subtypes to these physiological responses remain controversial. In the present study, a molecular approach was used to identify conclusively the signaling pathways activated in response to the individual alpha(1A)- and alpha(1B)-AR subtypes in cardiac myocytes. For this purpose, a mutant alpha(1a)-AR subtype (alpha(1a)-S(290/293)-AR) was constructed based on analogy to the previously described constitutively active mutant alpha(1b)-AR subtype (alpha(1b)-S(288-294)-AR). The mutant alpha(1a)-S(290/293)-AR subtype displayed constitutive activity based on four criteria. To introduce the constitutively active alpha(1)-AR subtypes into cardiac myocytes, recombinant Sindbis viruses encoding either the alpha(1a)-S(290/293)-AR or alpha(1b)-S(288-294)-AR subtype were used to infect the whole cell population with >90% efficiency, thereby allowing the biochemical activities of the various signaling pathways to be measured. When expressed at comparable levels, the alpha(1a)-S(290/293)-AR subtype exhibited a significantly elevated basal level as well as agonist-stimulated level of inositol phosphate accumulation, coincident with activation of atrial natriuretic factor-luciferase gene expression. By contrast, the alpha(1b)-S(288-294)-AR subtype displayed a markedly increased serum response element-luciferase gene expression but no activation of atrial natriuretic factor-luciferase gene expression. Taken together, this study provides the first molecular evidence for coupling of the alpha(1a)-AR and the alpha(1b)-AR subtypes to different signaling pathways in cardiac myocytes. 相似文献
106.
Zhao H Li CC Pardo J Chu PC Liao CX Huang J Dong JG Zhou X Huang Q Huang B Bennett MK Molineaux SM Lu H Daniel-Issakani S Payan DG Masuda ES 《Journal of immunology (Baltimore, Md. : 1950)》2005,174(9):5288-5297
TRAC-1 (T cell RING (really interesting new gene) protein identified in activation screen) is a novel E3 ubiquitin ligase identified from a retroviral vector-based T cell surface activation marker screen. The C-terminal truncated TRAC-1 specifically inhibited anti-TCR-mediated CD69 up-regulation in Jurkat cells, a human T leukemic cell line. In this study, we show that TRAC-1 is a RING finger ubiquitin E3 ligase with highest expression in lymphoid tissues. Point mutations that disrupt the Zn(2+)-chelating ability of its amino-terminal RING finger domain abolished TRAC-1's ligase activity and the dominant inhibitory effect of C-terminal truncated TRAC-1 on TCR stimulation. The results of in vitro biochemical studies indicate that TRAC-1 can stimulate the formation of both K48- and K63-linked polyubiquitin chains and therefore could potentially activate both degradative and regulatory ubiquitin-dependent pathways. Antisense oligonucleotides to TRAC-1 specifically reduced TRAC-1 mRNA levels in Jurkat and primary T cells and inhibited their activation in response to TCR cross-linking. Collectively, these results indicate that the E3 ubiquitin ligase TRAC-1 functions as a positive regulator of T cell activation. 相似文献
107.
108.
Parveen Kaur Parmar Charlene C. Barina Sharon Low Kyaw Thura Tun Conrad Otterness Pue P. Mhote Saw Nay Htoo Saw Win Kyaw Nai Aye Lwin Cynthia Maung Naw Merry Moo Eh Kalu Shwe Oo Daniel Reh Nai Chay Mon Nakul Singh Ravi Goyal Adam K. Richards 《PloS one》2015,10(5)
BackgroundMyanmar transitioned to a nominally civilian parliamentary government in March 2011. Qualitative reports suggest that exposure to violence and displacement has declined while international assistance for health services has increased. An assessment of the impact of these changes on the health and human rights situation has not been published.ConclusionThis large survey of health and human rights demonstrates that two years after political transition, vulnerable populations of eastern Myanmar are less likely to experience human rights violations compared to previous surveys. However, access to health services remains constrained, and risk of disease and death remains higher than the country as a whole. Efforts to address these poor health indicators should prioritize support for populations that remain outside the scope of most formal government and donor programs. 相似文献
109.
Ian Mcgowan Ross D. Cranston Kathryn Duffill Aaron Siegel Jarret C. Engstrom Alexyi Nikiforov Cindy Jacobson Khaja K. Rehman Julie Elliott Elena Khanukhova Kaleab Abebe Christine Mauck Hans M. L. Spiegel Charlene S. Dezzutti Lisa C. Rohan Mark A. Marzinke Hiwot Hiruy Craig W. Hendrix Nicola Richardson-Harman Peter A. Anton 《PloS one》2015,10(5)
Objectives
The CHARM-01 study characterized the safety, acceptability, pharmacokinetics (PK), and pharmacodynamics (PD) of three tenofovir (TFV) gels for rectal application. The vaginal formulation (VF) gel was previously used in the CAPRISA 004 and VOICE vaginal microbicide Phase 2B trials and the RMP-02/MTN-006 Phase 1 rectal safety study. The reduced glycerin VF (RGVF) gel was used in the MTN-007 Phase 1 rectal microbicide trial and is currently being evaluated in the MTN-017 Phase 2 rectal microbicide trial. A third rectal specific formulation (RF) gel was also evaluated in the CHARM-01 study.Methods
Participants received 4 mL of the three TFV gels in a blinded, crossover design: seven daily doses of RGVF, seven daily doses of RF, and six daily doses of placebo followed by one dose of VF, in a randomized sequence. Safety, acceptability, compartmental PK, and explant PD were monitored throughout the trial.Results
All three gels were found to be safe and acceptable. RF and RGVF PK were not significantly different. Median mucosal mononuclear cell (MMC) TFV-DP trended toward higher values for RF compared to RGVF (1136 and 320 fmol/106 cells respectively). Use of each gel in vivo was associated with significant inhibition of ex vivo colorectal tissue HIV infection. There was also a significant negative correlation between the tissue levels of TFV, tissue TFV-DP, MMC TFV-DP, rectal fluid TFV, and explant HIV-1 infection.Conclusions
All three formulations were found to be safe and acceptable. However, the safety profile of the VF gel was only based on exposure to one dose whereas participants received seven doses of the RGVF and RF gels. There was a trend towards higher tissue MMC levels of TFV-DP associated with use of the RF gel. Use of all gels was associated with significant inhibition of ex vivo tissue HIV infection.Trial Registration
ClinicalTrials.gov NCT01575405 相似文献110.
Microbubble‐mediated sonoporation for highly efficient transfection of recalcitrant human B‐ cell lines
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Charlene Li Ling Yong Dave Siak‐Wei Ow Tandiono Tandiono Lisa Li Mei Heng Ken Kwok‐Keung Chan Claus‐Dieter Ohl Evert Klaseboer Siew‐Wan Ohl Andre Boon‐Hwa Choo 《Biotechnology journal》2014,9(8):1081-1087
Sonoporation has not been widely explored as a strategy for the transfection of heterologous genes into notoriously difficult‐to‐transfect mammalian cell lines such as B cells. This technology utilizes ultrasound to create transient pores in the cell membrane, thus allowing the uptake of extraneous DNA into eukaryotic and prokaryotic cells, which is further enhanced by cationic microbubbles. This study investigates the use of sonoporation to deliver a plasmid encoding green fluorescent protein (GFP) into three human B‐cell lines (Ramos, Raji, Daudi). A higher transfection efficiency (TE) of >42% was achieved using sonoporation compared with <3% TE using the conventional lipofectamine method for Ramos cells. Upon further antibiotic selection of the transfected population for two weeks, we successfully enriched a stable population of GFP‐positive Ramos cells (>70%). Using the same strategy, Raji and Daudi B cells were also successfully transfected and enriched to 67 and 99% GFP‐positive cells, respectively. Here, we present sonoporation as a feasible non‐viral strategy for stable and highly efficient heterologous transfection of recalcitrant B‐cell lines. This is the first demonstration of a non‐viral method yielding transfection efficiencies significantly higher (42%) than the best reported values of electroporation (30%) for Ramos B‐cell lines. 相似文献