3,059 research outputs found
Ultrathin and nanostructured ZnO-based films for fluorescence biosensing applications
The fluorescence-based sensing capability of ultrathin ZnO-SiO(2) nanoplatforms, deposited by an integrated approach of colloidal lithography and metal organic chemical vapor deposition, has been investigated upon adsorption of fluorescein-labeled albumin, used as model analyte biomolecule. The protein immobilization process after spontaneous adsorption/desorption significantly enhances the green emission of the different ZnO-based films, as evidenced by scanning confocal microscopy, corresponding to a comparable protein coverage detected by X-ray photoelectron spectroscopy. Moreover, experiments of fluorescence recovery after photobleaching evidence that the protein lateral diffusion at the biointerface is affected by the chemical and/or topographical patterning of hybrid ZnO-SiO(2) surfaces. The used approach is very promising for biomolecular detection applications of these ZnO-SiO(2) nanoplatforms, by simple sizing of the 2D vs. 3D patterning design, which in turn is accomplished by the fine tuning of the integrated colloidal lithography-chemical vapor deposition processes. (C) 2011 Elsevier Inc. All rights reserved
Integration of Metal Organic Chemical Vapour Deposition and Wet Chemical Techniques to Obtain Highly Ordered Porous ZnO Nanoplatforms
Large-area, highly ordered ZnO micropores-arrays consisting of ZnO nanotubes delimited by ZnO nanorods have been successfully fabricated and tested for protein sensing applications. ZnO seed layers have been deposited by Metal Organic Chemical Vapour Deposition and readily patterned by Colloidal Lithography to attain ZnO nanorods growth at selective sites by Chemical Bath Deposition. The used synthetic approach has been proven effective for the easy assembly of ZnO nanoplatforms into high-density arrays. Both patterned and unpatterned ZnO nanorods have been morphologically and compositionally characterised and, thus, tested for model studies of protein mobility at the interface. The patterned layers, having a higher contribution of surface polar moieties than the corresponding unpatterned surfaces, exhibit a reduced lateral diffusion of the adsorbed protein. This evidence is related to the intrinsic porous nature of the ZnO hemispherical arrays characterised by a nanotube-nanorod hybrid networks. The present study gives a great impetus to the fabrication of tunable ZnO nanoplatforms having multiple morphologies and exceptionally high surface areas suitable for application in sensing devices
Mechanical Systems: Symmetry and Reduction
Reduction theory is concerned with mechanical systems with symmetries. It constructs a
lower dimensional reduced space in which associated conservation laws are taken out and
symmetries are \factored out" and studies the relation between the dynamics of the given
system with the dynamics on the reduced space. This subject is important in many areas,
such as stability of relative equilibria, geometric phases and integrable systems
Colloidal lithography and Metal-Organic Chemical Vapor Deposition process integration to fabricate ZnO nanohole arrays
A complete set up of optimal process conditions for an effective colloidal lithography/catalyst assisted MOCVD process integration is presented. It mainly focuses on the determination of the deposition temperature threshold for ZnO Metal-Organic Chemical Vapour Deposition (MOCVD) as well as the concentration of metal-organic silver (Ag) catalyst. Indeed, the optimization of such process parameters allows to tailor the ZnO film morphology in order to make the colloidal lithography/catalyst assisted MOCVD approach a valuable bottom up method to fabricate bi-dimensional ordered ZnO nanohole arrays. (C) 2010 Elsevier B.V. All rights reserved
Gas leakage and HV test procedure for the INFN Muon MWPCs
The Muon MWPCs produced by INFN laboratories are subject to gas leakage and HV tests before the installation on the LHCb experiment. The test procedure and the software tools developed are described in this paper
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AIDS-Related Services and Training in Outpatient Mental Health Care Agencies in New York
Directors of 471 outpatient mental health settings in New York State (82.1 percent of 574 settings located in counties with intermediate to high AIDS case rates) completed a survey about HIV and AIDS services, training needs, and barriers to care. Most of the sites served one to ten persons with HIV infection annually and had staff members who were trained in providing at least one HIV-related service. Nonetheless, 84 percent of the respondents reported
unmet needs for training. The likelihood of providing certain services was significantly increased in sites that were in urban locations, primarily served clients with comorbid alcohol or other drug use disorders, lacked funds for providing condoms, had staff members who were trained in HIV and AIDS services, identified particular HIV training needs, believed clients needed condoms, and viewed HIV-related services as very important
Neuroprotective Effect of a Nutritional Supplement Containing Spearmint Extract, Forskolin, Homotaurine and Group B Vitamins in a Mouse Model of Transient Ocular Hypertension
Glaucoma is one of the most common sight-threatening eye disorders and one of the main causes of irreversible blindness worldwide. The current therapies focusing on reducing intraocular pressure (IOP) are often insufficient to prevent the progression of the disease, so the therapeutic management of glaucoma remains a challenge. The aim of this study was to evaluate the neuroprotective, IOP-lowering independent effects of a nutritional supplement containing forskolin, homotaurine, spearmint extract and vitamins of the B group in a model of acute glaucoma developed in mice. Glaucoma was induced in adult wild-type C57BL/6J mice by transient elevation of IOP. The dietary supplement, branded as Gangliomix® (125 mg/kg/day), was administered by oral gavage for 17 days and ocular hypertension was induced on the 10th day of treatment. A histological analysis of the retinas was performed and RGC survival was evaluated with fluorogold labeling and Brn3a immunostaining on wholemount and retinal sections. Expression of alpha-spectrin, caspase-3, PARP-1 and GFAP was studied with western blotting or immunofluorescence. A significant increase in RGC survival was reported in the retina of mice treated with the dietary supplement as compared to vehicle-treated animals. The observed neuroprotection was associated with a calpain activity decrease, reduction in caspase-3 and PARP-1 activation, and prevention of GFAP upregulation. These effects were independent from the hypotensive effects of the supplement. Altogether, our data suggest that the dietary supplementation with forskolin, homotaurine, spearmint extract and vitamins of the B group supports RGC survival and may offer beneficial effects in glaucoma patients in combination with the currently used IOP-lowering therapy
Culture-based antibiotic susceptibility testing for Helicobacter pylori infection: a systematic review
Background Primary antibiotic resistance in Helicobacter pylori (H. pylori) strains is increasing worldwide, affecting therapy success. The use of therapies tailored on susceptibility pre-testing at culture has been proposed, but data are still conflicting. Method We performed a systematic review to evaluate the role of a culture-based therapeutic approach for H. pylori treatment, taking into account the sensitivity of culture and the success rates achieved with tailored therapies in different therapeutic steps. Results We analyzed data from 51 studies. Overall, H. pylori strains were isolated in 80.7% of 7889 patients, the success rates being 78.1%, 77.5%, 86.3% and 86.6%, before first-, second-, third-line or more therapies, respectively. In comparative studies, the infection was cured in 89.9% of 2052 patients treated with tailored therapies, and in 77.6% of 2516 patients receiving empiric therapy (P<0.001). However, in the subanalysis, the tailored approach achieved optimal eradication rates (>90%) only when it was applied before first-and second-line therapies, but not before third-line or more attempts (<80%). Moreover, no significant difference emerged between the 2 approaches when data from only the most recent (last 5 years) studies were considered, as well as in those performed in Western populations. Conclusions The attempt to achieve antibiotic susceptibility testing before treatment failed in 20% of infected patients managed in dedicated laboratories. Culture-tailored therapies administered after 2 or more therapies achieved suboptimal eradication rates. The role of bacterial culture in patients whose therapeutic management failed to eradicate H. pylori probably needs to be corroborated by further data
A 3D velocity model for earthquake location in Campi Flegrei area: application to the 1982-84 uplift event
The uplift crisis of the 1982-1984 in the Campi Flegrei area underlined
the importance of seismic surveillance for this volcanic caldera. One of the
key elements for an effective seismic network is to make use of a reliable velocity
model for earthquake location.
In the present work we will discuss criteria for the construction and validation
of a new 3D P-wave velocity model for earthquake location in the Campi
Flegrei area built from the integration of two high-resolution 3D tomographic
images of the region.
The model is used for locating a group of earthquakes from the uplift event of
the 1982-1984
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