999 resultados para 611.8


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Harnessing outgrowth endothelial cells (OECs) for vasoreparative therapy and tissue-engineering requires efficient ex-vivo expansion. How such expansion impacts on OEC function is largely unknown. In this study, we show that OECs become permanently cell-cycle arrested after ex-vivo expansion, which is associated with enlarged cell size, ß-galactosidase activity, DNA damage, tumour suppressor pathway activation and significant transcriptome changes. These senescence hallmarks were coupled with low telomerase activity and telomere shortening, indicating replicative senescence. OEC senescence limited their regenerative potential by impairing vasoreparative properties in-vitro and in-vivo. Integrated transcriptome-proteome analysis identified inflammatory signalling pathways as major mechanistic components of the OEC senescence programme. In particular, IL8 was an important facilitator of this senescence; depletion of IL8 in OECs significantly extended ex-vivo lifespan, delayed replicative senescence and enhanced function. While the ability to expand OEC numbers prior to autologous or allogeneic therapy remains a useful property, their replicative senescence and associated impairment of vasorepair needs to be considered. The current study also suggests that modulation of the senescence-associated secretory phenotype (SASP) could be used to optimise OEC therapy.

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Objectives
To determine whether excessive and often inappropriate or dangerous psychotropic drug dispensing to older adults is unique to care homes or is a continuation of community treatment.

Design
Population-based data-linkage study using prescription drug information.

Setting
Northern Ireland's national prescribing database and care home information from the national inspectorate.

Participants
Two hundred fifty thousand six hundred seventeen individuals aged 65 and older.

Measurements
Prescription information was extracted for all psychotropic drugs included in the British National Formulary (BNF) categories 4.1.1, 4.1.2, and 4.2.2 (hypnotics, anxiolytics, and antipsychotics) dispensed over the study period. Repeated cross-sectional analysis was used to monitor changes in psychotropic drug dispensing over time.

Results
Psychotropic drug use was higher in care homes than the community; 20.3% of those in care homes were dispensed an antipsychotic in January 2009, compared with 1.1% of those in the community. People who entered care had higher use of psychotropic medications before entry than those who did not enter care, but this increased sharply in the month of admission and continued to rise. Antipsychotic drug dispensing increased from 8.2% before entry to 18.6% after entering care (risk ratio (RR) = 2.26, 95% confidence interval (CI)=1.96–2.59) and hypnotic drug dispensing from 14.8% to 26.3% (RR=1.78, 95% CI=1.61–1.96).

Conclusion
A continuation of high use before entry cannot wholly explain the higher dispensing of psychotropic drugs to individuals in care homes. Although drug dispensing is high in older people in the community, it increases dramatically on entry to care. Routine medicine reviews are necessary in older people and are especially important during transitions of care.

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SU-8 epoxy-based negative photoresist has been extensively employed as a structural material for fabrication of numerous biological microelectro-mechanical systems (Bio-MEMS) or lab-on-a-chip (LOC) devices. However, SU-8 has a high autofluorescence level that limits sensitivity of microdevices that use fluorescence as the predominant detection workhorse. Here, we show that deposition of a thin gold nanoparticles layer onto the SU-8 surface significantly reduces the autofluorescence of the coated SU-8 surface by as much as 81% compared to bare SU-8. Furthermore, DNA probes can easily be immobilized on the Au surface with high thermal stability. These improvements enabled sensitive DNA detection by simple DNA hybridization down to 1 nM (a two orders of magnitude improvement) or by solid-phase PCR with sub-picomolar sensitivity. The approach is simple and easy to perform, making it suitable for various Bio-MEMs and LOC devices that use SU-8 as a structural material.

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This paper reports a surface modification of epoxy-based negative photoresist SU-8 for reducing its autofluorescence while enhancing its biofunctionality. By covalently depositing a thin layer of 20 nm Au nanoparticles (AuNPs) onto the SU-8 surface, we found that the AuNPs-coated SU-8 surface is much less fluorescent than the untreated SU-8. Moreover, DNA probes can easily be immobilized on the Au surface and are thermally stable over a wide range of temperature. These improvements will benefit bioanalytical applications such as DNA hybridization and solid-phase PCR (SP-PCR).

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This article describes a practical demonstration of a complete full-duplex “amplitude shift keying (ASK)” retrodirective radio frequency identification (RFID) transceiver array.The interrogator incorporates a “retrodirective array (RDA)” with a dual-conversion phase conjugating architecture in order to achieve better performance than is possible with conventional RFID solutions. Here mixers phase conjugate the incoming signal and a carrier recovery circuit recovers incoming angle of arrival phase information of an encoded amplitude shift keyed signal. The resulting interrogator provides a receiver sensitivity level of -109 dBm. A four element square patch RDA gives a 3 dB automatic beam steering angle of acceptance of ±45°. When compared to an RFID system operating by conventional (non-retrodirective) means retrodirective action leads to improved range extension of up to 16 times at ±45°. Operator pointing accuracy requirements are also reduced due to automatic retrodirective self-pointing. These features significantly enhance deployment opportunities requiring long range low equivalent isotropic radiation power (EIRP) and/or RFID tagging of moving platforms. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:160–164, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27258

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Malone, C. and S. Stoddart, Papers of the British School at Rome, 1992. 60: p. 1-69.

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Epithelia play important immunological roles at a variety of mucosal sites. We examined NFkappaB activity in control and TNF-alpha treated bovine mammary epithelial monolayers (BME-UV cells). A region of the bovine IL-8 (bIL-8) promoter was sequenced and a putative kappaB consensus sequence was identified bioinformatically. We used this sequence to analyse nuclear extracts for IL-8 specific NFkappaB activity. As a surrogate marker of NFkappaB activation, we investigated IL-8 release in two models. Firstly in BME-UV monolayers, IL-8 release in the presence of pro- and anti-inflammatory agents was determined by enzyme-linked immunosorbent assay (ELISA). Secondly, we measured IL-8 secretion from a novel model of intact mucosal sheets of bovine teat sinus. IL-8 release into bathing solutions was assessed following treatment with pro- and anti-inflammatory agents. TNF-alpha enhanced NFkappaB activity in bovine mammary epithelial monolayers. p65 NFkappaB homodimer was identified in both control and TNF-alpha treated cells. Novel sequencing of the bovine IL-8 promoter identified a putative kappaB consensus sequence, which specifically bound TNF-alpha inducible p50/p65 heterodimer. TNF-alpha induced primarily serosal IL-8 release in the cell culture model. Pre-treatment with anti-TNF or dexamethasone inhibited TNF-alpha induced IL-8 release. High dose interleukin-1beta (IL-1beta) induced IL-8 release, however significantly less potently than TNF-alpha. Bovine mammary mucosal tissue released high basal levels of IL-8 which were unaffected by TNF-alpha or IL-1beta but inhibited by both dexamethasone and anti-TNF. These data support a role for TNF-alpha in activation of NFkappaB and release of IL-8 from bovine mammary epithelial cells.

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Failure to efficiently induce apoptosis contributes to cisplatin resistance in non-small-cell lung cancer (NSCLC). Although BCL-2-associated X protein (BAX) and BCL-2 antagonist killer (BAK) are critical regulators of the mitochondrial apoptosis pathway, their requirement has not been robustly established in relation to cisplatin. Here, we show that cisplatin can efficiently bypass mitochondrial apoptosis block caused by loss of BAX and BAK, via activation of the extrinsic death receptor pathway in some model cell lines. Apoptosis resistance following cisplatin can only be observed when both extrinsic and intrinsic pathways are blocked, consistent with redundancy between mitochondrial and death receptor pathways in cisplatin-induced apoptosis. In H460 NSCLC cells, caspase-8 cleavage was shown to be induced by cisplatin and is dependent on death receptor 4, death receptor 5, Fas-associated protein with death domain, acid sphingomyelinase and ceramide synthesis. In contrast, cisplatin-resistant cells fail to activate caspase-8 via this pathway despite conserving sensitivity to death ligand-driven activation. Accordingly, caspase-8 activation block acquired during cisplatin resistance, can be bypassed by death receptor agonism. © 2012 Macmillan Publishers Limited

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The increased complexity and interconnectivity of Supervisory Control and Data Acquisition (SCADA) systems in the Smart Grid has exposed them to a wide range of cyber-security issues, and there are a multitude of potential access points for cyber attackers. This paper presents a SCADA-specific cyber-security test-bed which contains SCADA software and communication infrastructure. This test-bed is used to investigate an Address Resolution Protocol (ARP) spoofing based man-in-the-middle attack. Finally, the paper proposes a future work plan which focuses on applying intrusion detection and prevention technology to address cyber-security issues in SCADA systems.