NMR study of organic ligands at the AZO nanoparticle surface

Ligands provide physicochemical functionality to colloidal nanoparticles (NPs). Used during synthesis to control nucleation and growth, they end up as a monolayer covering the NP surface and stabilizing the NP colloidal suspension [1]. After synthesis, they can be exchanged by others to change the properties of the suspension or to improve certain characteristics [2]. In the last few years NMR techniques have been developed that can give a molecular view on the NPs from the ligands’ point of view, both in a qualitative and quantitative way. Using this ‘NMR toolbox’ different NPs and ligands have already been investigated [2-5]. In current research, two new types of NP materials are being investigated: Aluminium-Zinc-Oxide NPs (AZO-NPs) surrounded with oleic acid ligands, and Cupper-Indium-Gallium-Sulfide NPs (CIGS) surrounded by non-hydrogen containing tin-sulfide ligands. Preliminary results of these studies will be presented

Supporting information for National, regional, and worldwide estimates of low birthweight rates in 2015, with trends from 2000: a systematic analysis

Data produced by the World Health Organization, UNICEF, LSHTM and Johns Hopkins University to estimate national low birthweight (LBW) and numbers for 195 countries. LBW data was collated through a systematic review of national routine/registration systems, nationally representative surveys, and other data sources, and subsequently modelled using restricted maximum likelihood estimation with country-level random effects. Data includes a list of 1447 rate data points used as an input to the modelled estimates, yearly national-level covariates for each of the 195 countries studied from 2000 to 2015, and information on estimated low birthweight rates from 2000 to 2015 for 148 countries with data. Stata code used to generate these estimates is provided

Photocatalytic Performance of Undoped and Al-Doped ZnO Nanoparticles in the Degradation of Rhodamine B under UV-Visible Light:The Role of Defects and Morphology

Quasi-spherical undoped ZnO and Al-doped ZnO nanoparticles with different aluminum content, ranging from 0.5 to 5 at% of Al with respect to Zn, were synthesized. These nanoparticles were evaluated as photocatalysts in the photodegradation of the Rhodamine B (RhB) dye aqueous solution under UV-visible light irradiation. The undoped ZnO nanopowder annealed at 400 °C resulted in the highest degradation efficiency of ca. 81% after 4 h under green light irradiation (525 nm), in the presence of 5 mg of catalyst. The samples were characterized using ICP-OES, PXRD, TEM, FT-IR, 27Al-MAS NMR, UV-Vis and steady-state PL. The effect of Al-doping on the phase structure, shape and particle size was also investigated. Additional information arose from the annealed nanomaterials under dynamic N2 at different temperatures (400 and 550 °C). The position of aluminum in the ZnO lattice was identified by means of 27Al-MAS NMR. FT-IR gave further information about the type of tetrahedral sites occupied by aluminum. Photoluminescence showed that the insertion of dopant increases the oxygen vacancies reducing the peroxide-like species responsible for photocatalysis. The annealing temperature helps increase the number of red-emitting centers up to 400 °C, while at 550 °C, the photocatalytic performance drops due to the aggregation tendency

Theory and practice of microlensing lightcurves around fold singularities

Among all galactic microlensing events, those involving a passage of the observed source star over the caustic created by a binary lens are particularly useful in providing information about stellar atmospheres, the dynamics of stellar populations in our own and neighbouring galaxies, and the statistical properties of stellar and sub-stellar binaries. This paper presents a comprehensive guide for modelling and interpreting the lightcurves obtained in events involving fold-caustic crossings. A new general, consistent, and optimal choice of parameters provides a deep understanding of the involved features, avoids numerical difficulties and minimizes correlations between model parameters. While the photometric data of a microlensing event around a caustic crossing itself do not provide constraints on the characteristics of the underlying binary lens and does not allow predictions of the behaviour of other regions of the lightcurve, vital constraints can be obtained in an efficient way if these are combined with a few simple characteristics of data outside the caustic crossings. A corresponding algorithm containing some improvements over an earlier approach which takes into account multi-site observations is presented and discussed in detail together with the arising parameter constraints paying special attention to the role of source and background fluxes.Comment: 19 pages with 7 EPS figures embedded, LaTeX2e using mn2e.cls. Final version, tables clarifying meaning and constraints on parameters added. This is a preprint of an Article accepted for publication in Monthly Notices of the Royal Astronomical Society, (C) 2004 The Royal Astronomical Societ

A generalised finite difference scheme based on compact integrated radial basis function for flow in heterogeneous soils

In the present paper, we develop a generalised finite difference approach based on compact integrated radial basis function (CIRBF) stencils for solving highly nonlinear Richards equation governing fluid movement in heterogeneous soils. The proposed CIRBF scheme enjoys a high level of accuracy and a fast convergence rate with grid refinement owing to the combination of the integrated RBF approximation and compact approximation where the spatial derivatives are discretised in terms of the information of neighbouring nodes in a stencil. The CIRBF method is first verified through the solution of ordinary differential equations, 2-D Poisson equations and a Taylor-Green vortex. Numerical comparisons show that the CIRBF method outperforms some other methods in the literature. The CIRBF method in conjunction with a rational function transformation method and an adaptive time-stepping scheme is then applied to simulate 1-D and 2-D soil infiltrations effectively. The proposed solutions are more accurate and converge faster than those of the finite different method employed with a second-order central difference scheme. Additionally, the present scheme also takes less time to achieve target accuracy in comparison with the 1D-IRBF and HOC schemes

Dihydrolipoic Acid Induces Cytotoxicity in Mouse Blastocysts through Apoptosis Processes

α-Lipoic acid (LA) is a thiol with antioxidant properties that protects against oxidative stress-induced apoptosis. LA is absorbed from the diet, taken up by cells and tissues, and subsequently reduced to dihydrolipoic acid (DHLA). In view of the recent application of DHLA as a hydrophilic nanomaterial preparation, determination of its biosafety profile is essential. In the current study, we examined the cytotoxic effects of DHLA on mouse embryos at the blastocyst stage, subsequent embryonic attachment and outgrowth in vitro, in vivo implantation by embryo transfer, and early embryonic development in an animal model. Blastocysts treated with 50 μM DHLA exhibited significantly increased apoptosis and a corresponding decrease in total cell number. Notably, the implantation success rates of blastocysts pretreated with DHLA were lower than that of their control counterparts. Moreover, in vitro treatment with 50 μM DHLA was associated with increased resorption of post-implantation embryos and decreased fetal weight. Data obtained using an in vivo mouse model further disclosed that consumption of drinking water containing 100 μM DHLA led to decreased early embryo development, specifically, inhibition of development to the blastocyst stage. However, it appears that concentrations of DHLA lower than 50 μM do not exert a hazardous effect on embryonic development. Our results collectively indicate that in vitro and in vivo exposure to concentrations of DHLA higher than 50 μM DHLA induces apoptosis and retards early pre- and post-implantation development, and support the potential of DHLA to induce embryonic cytotoxicity

Lack of correlation between Ki-67 labelling index and tumor size of anterior pituitary adenomas

AIMS AND BACKGROUND: The Ki-67 is a nuclear antigen detected by the monoclonal antibody MIB-1 and its Labeling Index (LI) is considered a marker of normal and abnormal cell proliferation. Pituitary adenomas are generally well differentiated neoplasms, even if in about one third of cases they are invasive of surrounding tissues. The aim of this study is to evaluate the correlation between Ki-67 labelling index and tumor size of pituitary adenomas extimated by means CT and MRI and confirmed at operation. METHODS: Using the monoclonal antibody MIB-1, we evaluated the expression of Ki-67 in 121 anterior pituitary adenomas consecutively operated on in a 48-month period. RESULTS: In relation to neuroradiological (CT and MRI) and surgically verified tumor size, we identified 24 microadenomas, 27 intrasellar macroadenomas, 34 intra-suprasellar macroadenomas, and 36 intra-supra-parasellar macroadenomas. The adenomas were non-infiltrating (76 cases) and infiltrating (45 cases) adenomas. The wall of the cavernous sinus (CS) was infiltrated in 18 cases. Forty-eight adenomas were non-functioning and 73 functioning. The overall mean ± SD Ki-67 LI was 2.72 ± 2.49% (median 1.6). It was 2.59 ± 1.81 in microadenomas, 2.63 ± 3.45 in intrasellar macroadenomas, 1.91 ± 2.11 in intra-suprasellar macroadenomas, and 3.29 ± 5.45 in intra-supra-parasellar macroadenomas (p = 0.27). It was 3.73 ± 5.13% in infiltrating and 2.03 ± 2.41% in non-infiltrating adenomas (p = 0.02), and 5.61 ± 7.19% in CS-infiltrating versus 2.09 ± 2.37% in CS-non-infiltrating adenomas (p = 0.0005). CONCLUSIONS: Our preliminary results seem to exclude significative correlations between Ki-67 LI and tumor size of anterior pituitary adenomas, even if this index can be considered a useful marker in the determination of the infiltrative behaviour of these tumors

Disinfection of football protective equipment using chlorine dioxide produced by the ICA TriNova system

<p>Abstract</p> <p>Backround</p> <p>Community-associated methicillin-resistant <it>Staphylococcus aureus </it>outbreaks have occurred in individuals engaged in athletic activities such as wrestling and football. Potential disease reduction interventions include the reduction or elimination of bacteria on common use items such as equipment. Chlorine dioxide has a long history of use as a disinfectant. The purpose of this investigation was to evaluate the ability of novel portable chlorine dioxide generation devices to eliminate bacteria contamination of helmets and pads used by individuals engaged in football.</p> <p>Methods</p> <p>In field studies, the number of bacteria associated with heavily used football helmets and shoulder pads was determined before and after overnight treatment with chlorine dioxide gas. Bacteria were recovered using cotton swabs and plated onto trypticase soy agar plates. In laboratory studies, <it>Staphylococcus aureus </it>was applied directly to pads. The penetration of bacteria into the pads was determined by inoculating agar plates with portions of the pads taken from the different layers of padding. The ability to eliminate bacteria on the pad surface and underlying foam layers after treatment with chlorine dioxide was also determined.</p> <p>Results</p> <p>Rates of recovery of bacteria after treatment clearly demonstrated that chlorine dioxide significantly (p < 0.001) reduce and eliminated bacteria found on the surface of pads. For example, the soft surface of shoulder pads from a university averaged 2.7 × 10³recoverable bacteria colonies before chlorine dioxide treatment and 1.3 × 10²recoverable colonies after treatment. In addition, the gas was capable of penetrating the mesh surface layer and killing bacteria in the underlying foam pad layers. Here, 7 × 10³to 4.5 × 10³laboratory applied <it>S. aureus </it>colonies were recovered from underlying layers before treatment and 0 colonies were present after treatment. Both naturally occurring bacteria and <it>S. aureus </it>were susceptible to the treatment process.</p> <p>Conclusion</p> <p>Results of this study have shown that chlorine dioxide can easily and safely be used to eliminate bacteria contamination of protective pads used by football players. This could serve to reduce exposure to potential pathogens such as the methicillin-resistant <it>Staphylococcus aureus </it>among this group of individuals.</p