Combinatorial doping of TiO_2 with platinum (Pt), chromium (Cr), vanadium (V), and nickel (Ni) to achieve enhanced photocatalytic activity with visible light irradiation

Titanium dioxide (TiO_2) was doped with the combination of several metal ions including platinum (Pt), chromium (Cr), vanadium (V), and nickel (Ni). The doped TiO_2 materials were synthesized by standard sol-gel methods with doping levels of 0.1 to 0.5 at.%. The resulting materials were characterized by x-ray diffraction (XRD), BET surface-area measurement, scanning electron microscopy (SEM), and UV-vis diffuse reflectance spectroscopy (DRS). The visible light photocatalytic activity of the codoped samples was quantified by measuring the rate of the oxidation of iodide, the rate of degradation of methylene blue (MB), and the rate of oxidation of phenol in aqueous solutions at λ > 400 nm. 0.3 at.% Pt-Cr-TiO_2 and 0.3 at.% Cr-V-TiO_2 showed the highest visible light photocatalytic activity with respect to MB degradation and iodide oxidation, respectively. However, none of the codoped TiO_2 samples were found to have enhanced photocatalytic activity for phenol degradation when compared to their single-doped TiO_2 counterparts

Effects of Single Metal-Ion Doping on the Visible-Light Photoreactivity of TiO_2

Titanium dioxide (M-TiO_2), which was doped with 13 different metal ions (i.e., silver (Ag^+), rubidium (Rb^+), nickel (Ni^(2+)), cobalt (Co^(2+)), copper (Cu^(2+)), vanadium (V^(3+)), ruthenium (Ru^(3+)), iron (Fe^(3+)), osmium (Os^(3+)), yttrium (Y^(3+)), lanthanum (La^(3+)), platinum (Pt^(4+), Pt^(2+)), and chromium (Cr3+, Cr6+)) at doping levels ranging from 0.1 to 1.0 at. %, was synthesized by standard sol−gel methods and characterized by X-ray diffraction, BET surface area measurement, SEM, and UV−vis diffuse reflectance spectroscopy. Doping with Pt(IV/II), Cr(III), V(III), and Fe(III) resulted in a lower anatase to rutile phase transformation (A−R phase transformation) temperature for the resultant TiO_2 particles, while doping with Ru(III) inhibited the A−R phase transformation. Metal-ion doping also resulted in a red shift of the photophysical response of TiO_2 that was reflected in an extended absorption in the visible region between 400 and 700 nm. In contrast, doping with Ag(I), Rb(I), Y(III), and La(III) did not result in a red shift of the absorption spectrum of TiO_2. As confirmed by elemental composition analysis by energy dispersive X-ray spectroscopy, the latter group of ions was unable to be substituted for Ti(IV) in the crystalline matrix due to their incompatible ionic radii. The photocatalytic activities of doped TiO_2 samples were quantified in terms of the photobleaching of methylene blue, the oxidation of iodide (I^(−)), and the oxidative degradation of phenol in aqueous solution both under visible-light irradiation (λ > 400 nm) and under broader-band UV−vis irradiation (λ > 320 nm). Pt- and Cr-doped TiO_2, which had relatively high percentages of rutile in the particle phase, showed significantly enhanced visible-light photocatalytic activity for all three reaction classes

Improving the recording of clinical medicolegal findings in South Africa

Background. The accurate recording of findings in clinical medicolegal cases is important, yet the current J88 form used for this purpose in South Africa has been reported to have many flaws. In addition, there are reports of poor completion of the form, which could in part be due to its poor design and clarity.Objective. To describe the process that was undertaken to revise the current J88 form.Methods. A repetitive consultative process was used to revise the current J88 form and to obtain inputs from relevant government institutions.Results. A brief outline of the changes that have been made to the current J88 form and the reasons why these changes were proposed by national experts is provided.Conclusion. The revised J88 form will provide clearer guidance to healthcare providers on the completion of necessary information in an expedited fashion. It is hoped that the form will soon be approved by the necessary government institutions

Recovering of DNA evidence after rape

Objective. Sexual assault evidence collection kits (SAECKs) are used to collect evidence for DNA recovery after rape. The aim of this study was to assess the extent of completion of the kits by health care workers in 6 provinces of South Africa. Methods. A cross-sectional study was conducted to code SAECKs that were analysed at one forensic science laboratory in South Africa. Results. The findings from 204 SAECKs that were analysed are presented. The study found that none of the SAECKs complied fully with administrative quality requirements. Almost all of the specimens that were collected were analysed, except for pubic and head hair specimens that were rarely collected and analysed. A availability of all three genital swabs for forensic DNA analysis were found to be significant as this increased the chance of evidence recovery and obtaining a foreign forensic DNA profile. In 80% of cases, the DNA matched the suspect. Conclusions. The importance of administrative quality and the significance of collecting all three genital specimens should be emphasised in training programmes for health care workers. The study raises questions related to other aspects of sexual assault services and has implications regarding the overall quality of care that survivors receive

Unspoken victims: A national study of male rape incidents and police investigations in South Africa

Background. The burden of sexual violence has been well described in children of both sexes and in women, but there is minimal literature on adult male rape victims. Studies of adult male rape victims have mainly been conducted among incarcerated males or military personnel, and in high-income countries.Objectives. To describe the epidemiology, occurrence and reporting of rape cases involving male victims, both child (<18 years old) and adult, in South Africa (SA).Methods. The study consisted of a nationally representative sample of case dockets maintained by the SA Police Service of rape incidents reported in 2012. A retrospective review of the dockets provided sociodemographic information on the victim and suspect, the circumstances of the rape and the medicolegal services provided to the victim. Data on male victims were analysed using Stata 13 to test for significant differences between child and adult male victims.Results. The study comprised 209 male victims, including 120 (57.4%) children and 89 (42.6%) adults. The findings showed that there were significant differences in the occurrence and reporting of rape of male victims by age. Adult males experienced more violent rapes, perpetrators were more likely to be armed and often humiliated the victim, and rapes were more likely to occur in institutional settings. Adult males reported incidents of rape earlier and therefore had visible non-genital injuries during the medical examination. In contrast, more child rapes involved known perpetrators, occurred in a home and perpetrators were more likely to act kindly to the victim after the incident. This parallels the patterns in rape circumstances seen in female adult and child victims.Conclusions. While there is political commitment to understanding sexual violence against women as a societal problem, work on such violence against men lags behind and is little understood. Rape of males needs to be acknowledged, and their vulnerabilities to sexual abuse and rape need to be addressed. Prevention efforts to end violence against women and girls, especially in relation to children, can be used to address violence against men and boys

Educational Attainment, Teaching Experience, Professional Development and Self-Efficacy as Predictors of Chemistry Content Knowledge: Implication for the Development of a National Promotion Examination

This study examined teachers’ content knowledge (CK) in chemistry and its relationship to teachers’ chemistry background, teaching experience, involvement in professional development and self-efficacy It was further investigated which variables predicted the level of content knowledge (CK) of one hundred public secondary chemistry teachers. The data shows that the majority of science teachers have low level of CK in Chemistry. Teaching experience, professional development, chemistry background, and selfefficacy were significantly related to the CK of teachers. Teachers\u27 professional development and self-efficacy predicted the CK of teachers

ISSUES IN MEDICINE: Recommendations to improve the National Development Plan for Health

In November 2011, a draft National Development Plan (NDP) was released that addresses two of South Africa’s major challenges: poverty and inequity. Health and economic development are interdependent, presenting an important opportunity through the NDP to integrate health within goals of broader socioeconomic development. Reviewing the NDP identified gaps based on evidence and the epidemiological risk profile of South Africa. Recommendations to improve the NDP and to deal withpoverty and inequity should focus on prevention and addressing the social determinants of health, including: (i) a multisectoral approach to establish a comprehensive early childhood development programme; (ii) fiscal and legislative policies to bolster efforts to reduce the burden of  non-communicable diseases; (iii) promoting and maintaining a healthy workforce; and (iv) promoting a culture of evidence-based priority setting.Achieving the goal of ‘a long and healthy life for all South Africans’ will require healthy public policies, well-functioning institutional and physical infrastructure, social solidarity, and an active and conscientious civil society

Medico-Legal Findings, Legal Case Progression, and Outcomes in South African Rape Cases: Retrospective Review

Rachel Jewkes and colleagues examine the processing of rape cases by South African police and courts and show an association between documentation of ano-genital injuries, trials commencing, and convictions in rape cases

Development and evaluation of gellan gum/silk fibroin/chondroitin sulfate ternary injectable hydrogel for cartilage tissue engineering

Hydrogel is in the spotlight as a useful biomaterial in the field of drug delivery and tissue engineering due to its similar biological properties to a native extracellular matrix (ECM). Herein, we proposed a ternary hydrogel of gellan gum (GG), silk fibroin (SF), and chondroitin sulfate (CS) as a biomaterial for cartilage tissue engineering. The hydrogels were fabricated with a facile combination of the physical and chemical crosslinking method. The purpose of this study was to find the proper content of SF and GG for the ternary matrix and confirm the applicability of the hydrogel in vitro and in vivo. The chemical and mechanical properties were measured to confirm the suitability of the hydrogel for cartilage tissue engineering. The biocompatibility of the hydrogels was investigated by analyzing the cell morphology, adhesion, proliferation, migration, and growth of articular chondrocytes-laden hydrogels. The results showed that the higher proportion of GG enhanced the mechanical properties of the hydrogel but the groups with over 0.75% of GG exhibited gelling temperatures over 40 °C, which was a harsh condition for cell encapsulation. The 0.3% GG/3.7% SF/CS and 0.5% GG/3.5% SF/CS hydrogels were chosen for the in vitro study. The cells that were encapsulated in the hydrogels did not show any abnormalities and exhibited low cytotoxicity. The biochemical properties and gene expression of the encapsulated cells exhibited positive cell growth and expression of cartilage-specific ECM and genes in the 0.5% GG/3.5% SF/CS hydrogel. Overall, the study of the GG/SF/CS ternary hydrogel with an appropriate content showed that the combination of GG, SF, and CS can synergistically promote articular cartilage defect repair and has considerable potential for application as a biomaterial in cartilage tissue engineering.This research was supported by the International Research and Development Program of the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (NRF-2017K1A3A7A03089427) and by the bilateral cooperation Program of the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (NRF-2019K2A9A1A06098563)

The Ursinus Weekly, November 6, 1975

Lloyd joins German Dept. • Parking problems • AAUP speaker discusses Union • Student apprehended • Psych Club news • State of the Union • Hot flicks in Philly • Gurzynski hits century mark • Bearettes tie W. C. • Widener wallops whazoo\u27s woefuls! • Phila. Sixers\u27 hoopla • Here and there • El Espanol vivahttps://digitalcommons.ursinus.edu/weekly/1045/thumbnail.jp