Methodological approach for mineralogical characterization of tailings from a Cu(Au,Ag) skarn type deposit using QEMSCAN (Quantitative Evaluation of Minerals by Scanning Electron Microscopy)

Skarn type deposits are important potential resources for Cu, Au, and Ag as well as other strategic metals, which require accurate characterization of the mineralogy, texture and grade for successful processing and environmental management. The mineralogy of these deposits and of the resulting tailings has traditionally been examined using transmitted light microscopy, cathodoluminescence, X-ray diffraction, scanning electron microscopy, and electron probe microanalysis. In the present study, the Quantitative Evaluation of Minerals by Scanning Electron Microscopy (QEMSCAN (R)) technology was applied to rapidly acquire spatially resolved mineralogical data from tailings associated with a Cu(Au,Ag) skarn type deposit. The resulting modal and textural data provided relevant additional information on the distribution of the ore minerals, including detail on the trace minerals, grain size distributions, and mineral associations. The following benefits of detailed mineralogical knowledge from this study can be pointed out it improves the lithotyping of these complex deposit types and will benefit their ore processing strategies; it allows inferences to be made about the environmental behavior of the tailings, namely the acid mine drainage potential; it provides data about deportment of penalty and toxic elements, which are specifically As, Te, and Sb. Thus, particular applications of QEMSCAN include assessments of the acid consumption of the mineral assemblages (mainly assured due to calcite and dolomite) and of the abundance, distribution and mobility of potentially toxic elements, such as As

Detrimental Effect Of Fungal 60-kda Heat Shock Protein On Experimental Paracoccidioides Brasiliensis Infection

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The genus Paracoccidioides comprises species of dimorphic fungi that cause paracocci-dioidomycosis (PCM), a systemic disease prevalent in Latin America. Here, we investigated whether administration of native 60-kDa heat shock protein of P. brasiliensis (nPbHsp60) or its recombinant counterpart (rPbHsp60) affected the course of experimental PCM. Mice were subcutaneously injected with nPbHsp60 or rPbHsp60 emulsified in complete's Freund Adjuvant (CFA) at three weeks after intravenous injection of P. brasiliensis yeasts. Infected control mice were injected with CFA or isotonic saline solution alone. Thirty days after the nPbHsp60 or rPbHsp60 administration, mice showed remarkably increased fungal load, tissue inflammation, and granulomas in the lungs, liver, and spleen compared with control mice. Further, rPbHsp60 treatment (i) decreased the known protective effect of CFA against PCM and (ii) increased the concentrations of IL-17, TNF-alpha, IL-12, IFN-gamma, IL-4, IL-10, and TGF-beta in the lungs. Together, our results indicated that PbHsp60 induced a harmful immune response, exacerbated inflammation, and promoted fungal dissemination. Therefore, we propose that PbHsp60 contributes to the fungal pathogenesis.119Fundacao de Amparo a Pesquisa do Estado de Sao Paulo [2009/14777-1, 2013/12278-3, 2009/03235-3, 2012/08552-0]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Enhanced three-phase shunt active power filter interfacing a renewable and an energy storage system

This paper presents an enhanced three-phase shunt active power filter (SAPF) that, besides its inherent functionalities of power quality problems compensation, also allows the interface of a renewable energy source (RES, namely solar photovoltaic – PV panels) and an energy storage system (ESS, namely batteries) through its dc-link. On the power grid-side, a three-phase four-wire voltage-source ac-dc converter is connected with the power grid, operating as an SAPF, whereas the RES-interface and the ESS-interface are made through a three-port multilevel dc-dc converter connected to the dc-link of the SAPF. Besides, to compensate power quality problems related to currents, the SAPF also permits the controllability of the bidirectional power exchanged between the power grid and the dc interfaces, i.e., the RES and the ESS. The operation principle of the whole system, as well as the detailed control algorithms, are described in the paper. A validation was performed through computer simulations, where it is possible to analyze the different operation modes of the enhanced SAPF interfacing a RES and an ESS through the dc-link.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020. This work has been supported by the FCT Project newERA4GRIDs PTDC/EEI-EEE/30283/2017. Tiago J. C. Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by FCT

Surface engineering of silica nanoparticles for oral insulin delivery: characterization and cell toxicity studies

The present work aimed at studying the interaction between insulin and SiNP surfaced with mucoadhesive polymers (chitosan, sodium alginate or polyethylene glycol) and the evaluation of their biocompatibility with HepG2 and Caco-2 cell lines, which mimic in vivo the target of insulin-loaded nanoparticles upon oral administration. Thus, a systematic physicochemical study of the surface-modified insulin-silica nanoparticles (Ins-SiNP) using mucoadhesive polymers has been described. The surfacing of nanoparticle involved the coating of silica nanoparticles (SiNP) with different mucoadhesive polymers, to achieve high contact between the systems and the gut mucosa to enhance the oral insulin bioavailability. SiNP were prepared by a modified Stöber method at room temperature via hydrolysis and condensation of tetraethyl orthosilicate (TEOS). Interaction between insulin and nanoparticles was assessed by differential scanning calorimetry (DSC), X-ray and Fourier-transform infrared (FTIR) studies. The high efficiency of nanoparticles' coating resulted in more stable system. FTIR spectra of insulin-loaded nanoparticles showed amide absorption bands which are characteristic of α-helix content. In general, all developed nanoparticles demonstrated high biocompatible, at the tested concentrations (50-500 μg/mL), revealing no or low toxicity in the two human cancer cell lines (HepG2 and Caco-2). In conclusion, the developed insulin-loaded SiNP surfaced with mucoadhesive polymers demonstrated its added value for oral administration of proteins

Client needs and satisfaction in an HIV facility

Health care evaluation serves the purpose of monitoring the quality of health care provided by Health Care Providers (HCP), so that health care services can be provided most effectively and efficiently. Patient satisfaction studies are widely used to assess the quality of outpatient care. A client satisfaction study was conducted at an HIV health care facility in Sydney, Australia during 2007-2008. There were three objectives: 1.) To validate a questionnaire for future determination of client satisfaction in HIV health care facilities. 2.) To identify the levels of satisfaction of clients, and investigate any dissatisfaction and unmet needs towards HIV health care. 3.) To provide recommendations for improving client satisfaction levels in HIV health care. This research used a mixed method approach and consisted of two phases. The first phase was a quantitative survey conducted with 166 clients (both HIV positive and negative) at Albion Street Centre (ASC) using a newly-devised questionnaire. Clients were asked to answer demographic questions, rate their levels of satisfaction with each aspect and each HCP category, and provide suggestions for improvement. Quantitative statistical analysis was conducted to obtain a general view of client satisfaction levels. Dissatisfaction and unmet needs of clients were then investigated in-depth in the second phase of the research through qualitative face-to-face semi-structured interviews. Twenty-two clients (both HIV positive and negative) at ASC were interviewed individually and asked about their attitudes, perceptions, and experiences towards their HCP and the HIV health care services received. Thematic analysis was used to categorise and interpret the qualitative data. More than 90% of the clients were satisfied with most of the aspects covered in the survey, with a mean overall satisfaction score of 84 out of 100. Clients were most iii satisfied with the “technical quality” and “interpersonal manner” of the HCP, and were least satisfied with “waiting time” and “availability of HCP”. The HCP category with which the clients has the highest level of satisfaction was “nurses” (86%), followed by “psychologists” (84%), then “doctors” (83%). Clients who were HIV negative, had a full time job, visited ASC less frequently, or did not possess any type of Health Care Card were more satisfied with the services overall. No common dissatisfaction or unmet needs towards HIV health care service were identified. “Technical quality of HCP” and “the relationship with HCP” were the two most important determinants of client satisfaction, which outweighed the inconvenience contributed by the poor availability of HCP and the location of ASC. The maintenance of “confidentiality/privacy” was shown to be fundamental in HIV health care facilities. The multi-disciplinary nature of ASC increased the degree of convenience and satisfaction level among clients. Suggestions for improvement in client satisfaction levels include increasing the attractiveness of the physical environment and the variety of educational reading materials in the waiting area; introducing beverages, and encouraging clients to be involved in their treatment decisions. Health care administrative staff in particular are reminded not to neglect the importance of the availability of HCP, accessibility, and physical environment when establishing a new HIV health care facility. The mixed method approach (quantitative survey and qualitative interviews) proved beneficial. It increased the validity of the findings by assessing client satisfaction levels using more than one method. This enabled clarification of ambiguities noted in the initial survey through probes used in the interviews, and also allowed investigation of the determinants of client satisfaction through understanding their experiences in HIV health care. Future client satisfaction studies would benefit from using this approach

Quantitative and Qualitative Characteristics of the Loin of Grazing Lambs From Different Production Systems

The international sheep market is supplied mainly from New Zealand and Australia, where there are advanced production systems and marketing organisations, and where the product is exported mainly in the form of carcasses and cuts. In Brazil, the farmers should aim to produce a younger animal, with an adequate fat level at an optimum stage of muscle development, in order to gain market share The proportions of muscle, bone and fat largely determine the value of the carcass, and the breed and age of animal, in addition to other factors such as feeding systems, cause variation in the proportions (Purchas et al., 1991). Grazing systems may be considered in Brazil due to reduced production costs. Measuring M. longissimus (the loin muscle) traits is a way of evaluating carcass quality because this muscle is one of the most important commercial cuts and represents total carcass characteristics. The objective of this study was to determine qualitative and quantitative characteristics of the loin of lambs on different production systems

Nanostructure of cellulose microfibrils in spruce wood

The structure of cellulose microfibrils in wood is not known in detail, despite the abundance of cellulose in woody biomass and its importance for biology, energy, and engineering. The structure of the microfibrils of spruce wood cellulose was investigated using a range of spectroscopic methods coupled to small-angle neutron and wide-angle X-ray scattering. The scattering data were consistent with 24-chain microfibrils and favored a “rectangular” model with both hydrophobic and hydrophilic surfaces exposed. Disorder in chain packing and hydrogen bonding was shown to increase outwards from the microfibril center. The extent of disorder blurred the distinction between the I alpha and I beta allomorphs. Chains at the surface were distinct in conformation, with high levels of conformational disorder at C-6, less intramolecular hydrogen bonding and more outward-directed hydrogen bonding. Axial disorder could be explained in terms of twisting of the microfibrils, with implications for their biosynthesis