Lixiviation of a silver ore by the Russell process

The purpose of this investigation was to determine by a series of experiments, the action of the Russell solution on a particular ore; and to determine the best size to crush to, the strength of the solution to use, the temperature most suited, and the length of time for best extraction, and finally to come to a conclusion whether or not the ore was suited to this Process --page 1

A Teaching Innovation on Poverty for Interprofessional Students: Cost of Poverty Experience Simulation

INTRODUCTION Cost of Poverty Experience (COPE) simulation is an innovative teaching methodology to demonstrate the obstacles and challenges of poverty that contribute to those risks. The aim of the study was to evaluate the change in attitudes regarding people living in poverty among interprofessional health science students. METHODS Medicine, nursing, pharmacy and rehabilitation therapy students in the 2018 Interprofessional Education class (N=100) were enrolled. Interprofessional student teams were assigned family roles, given limited resources and simulated poverty challenges such as unemployment, childcare concerns, limited access to healthy food, and incarceration. A pre- and post-simulation survey measured changes in participants’ poverty awareness consisting of three domains - identifying barriers to poverty, confidence in one’s ability to address poverty, and likelihood to engage in behaviors to address poverty. The post survey also included questions on insights gained and recognition of organizational systems that perpetuate poverty. Statistical analysis including descriptive statistics and paired t-tests were conducted in SPSS-v23. RESULTS The confidence in ability domain that included understanding obstacles, identifying key issues and having impact showed a significant difference between pre-test (M=8.63, SD= 1.71) and post-test (M=9.31, SD=1.90). However, no significant change was reported for identifying barriers and likelihood to engage in behaviors to address poverty. Additionally, in post-survey, more than 90% students reported increased mindfulness of poverty, self-reflection, and recognize that organizational systems create and perpetuate poverty. CONCLUSION Poverty immersive simulation experience is an essential education tool, as it motivates critical self-reflection and improves one’s confidence to engage in addressing poverty

Specific Surface

Surface area largely determines many physical and chemical properties of materials. Physical adsorption of molecules, heat loss or gain resulting from that adsorption, swelling and shrinking, and many other physical and chemical processes are closely related to surface area. Surface or exposed area is also closely related to and often the controlling factor in many biological processes. Soils vary widely in their reactive surface because of differences in mineralogical and organic composition and in their particle-size distribution. Water retention and movement, cation exchange capacity, and pesticide adsorption are closely related to the specific surface (defined as the surface area per unit mass of soil). Specific surface is usually expressed in square meters per gram (m2/g)

Mixed magnesium-aluminiun hydroxides. I. Preparation and characterization of compounds formed in dialysed systems

RESP-576

Aflatoxin Toxicity Reduction in Feed by Enhanced Binding to Surface-Modified Clay Additives

Animal feeding studies have demonstrated that clay additives, such as bentonites, can bind aflatoxins in ingested feed and reduce or eliminate the toxicity. Bentonite deposits are found throughout the world and mostly consist of expandable smectite minerals, such as montmorillonite. The surfaces of smectite minerals can be treated with organic compounds to create surface-modified clays that more readily bind some contaminants than the untreated clay. Montmorillonites treated with organic cations, such as hexadecyltrimethylammonium (HDTMA) and phenyltrimethylammonium (PTMA), more effectively remove organic contaminants, such as benzene and toluene, from water than untreated clay. Similarly, montmorillonite treated with PTMA (Kd = 24,100) retained more aflatoxin B1 (AfB1) from aqueous corn flour than untreated montmorillonite (Kd = 944). Feed additives that reduced aflatoxin toxicity in animal feeding studies adsorbed more AfB1 from aqueous corn flour than feed additives that were less effective. The organic cations HDTMA and PTMA are considered toxic and would not be suitable for clay additives used in feed or food, but other non-toxic or nutrient compounds can be used to prepare surface-modified clays. Montmorillonite (SWy) treated with choline (Kd = 13,800) and carnitine (Kd = 3960) adsorbed much more AfB1 from aqueous corn flour than the untreated clay (Kd = 944). A choline-treated clay prepared from a reduced-charge, high-charge montmorillonite (Kd = 20,100) adsorbed more AfB1 than the choline-treated high-charge montmorillonite (Kd = 1340) or the untreated montmorillonite (Kd = 293). Surface-modified clay additives prepared using low-charge smectites and nutrient or non-toxic organic compounds might be used to more effectively bind aflatoxins in contaminated feed or food and prevent toxicity

Effects of soluble flavin on heterogeneous electron transfer between surface exposed bacterial cytochromes and iron oxides

Dissimilatory iron-reducing bacteria can utilize insoluble Fe(Mn)-oxides as a terminal electron acceptor under anaerobic conditions. For Shewanella species specifically, multiple evidences suggest that iron reduction is associated with the secretion of flavin mononucleotide (FMN) and riboflavin. However, the exact mechanism of flavin involvement is unclear; while some indicate that flavins mediate electron transfer (Marsili et al., 2008), others point to flavin serving as cofactors to outer membrane proteins (Okamoto et al., 2013). In this work, we used methyl viologen (MV•+)-encapsulated, porin-cytochrome complex (MtrCAB) embedded liposomes (MELs) as a synthetic model of the Shewanella outer membrane to investigate the proposed mediating behavior of microbially produced flavins. The reduction kinetics of goethite, hematite nand lepidocrocite (200 μM) by MELs ([MV•+] ~ 42 μM and MtrABC ≤ 1 nM) were determined in the presence FMN at pH 7.0 in N2 atmosphere by monitoring the concentrations of MV•+ and FMN through their characteristic UV-visible absorption spectra. Experiments were performed where i) FMN and Fe(III)-oxide were mixed and then reacted with the reduced MELs and ii) FMN was reacted with the reduced MELs followed by addition of Fe(III)-oxide. The redox reactions proceeded in two steps: a fast step that was completed in a few seconds, and a slower one lasting over 400 seconds. For all three Fe(III)-oxides, the initial reaction rate in the presence of a low concentration of FMN (≤ 1 μM) was at least a factor of five faster than those with MELs alone, and orders of magnitude faster than those by FMNH2, suggesting that FMN may serve as a co-factor that enhances electron transfer from outer-membrane c-cytochromes to nFe(III)-oxides. The rate and extent of the initial reaction followed the order of lepidocrocite > hematite > goethite, the same as their reduction potentials, implying thermodynamic control on reaction rate. For LEP, with the highest reduction potential among the three Fe(III)-oxides, its reduction by FMNH2 completed in less than 10 minutes, suggesting that FMN is capable of mediating electron transfer to LEP. At higher FMN concentrations (> 1 μM), the reaction rates for both steps decreased and varied inversely with FMN concentration, indicating that FMN inhibited the MEL to Fe(III)-oxide electron transfer reaction under these conditions. The implications of the observed kinetic behaviors to flavin-mediated Fe(III) oxide reduction in natural environments are discussed

Chumnguh Thleum: Understanding Liver Illness and Hepatitis B Among Cambodian Immigrants

Cambodian immigrants are over 25 times more likely to have evidence of chronic hepatitis B infection than the general US population. Carriers of HBV are over 100 times more likely to develop liver cancer than non-carriers. Liver cancer incidence is the second leading cancer for Cambodian men and the sixth for Cambodian women. Despite this, this underserved population has received very little attention from health disparities researchers. Culturally and linguistically appropriate interventions are necessary to increase hepatitis B knowledge, serologic testing, and vaccination among Cambodian Americans. Eight group interviews were held with Cambodian American men (48) and women (49). Focus group discussion revealed unanticipated information about sociocultural influences on participants’ understanding about hepatitis B transmission, disease course, and prevention and treatment informed by humoral theories underlying Khmer medicine, by biomedicine, and by migration experiences. Our findings reveal the value of qualitative exploration to providing cultural context to biomedical information—a formula for effective health promotion and practice