Effect of Dispersions of Al2O3 on the Physical and Mechanical Properties of Pure Copper and Copper-Nickel Alloy

This paper illustrates the mechanical and physical properties of pure Cu and Cu-Ni (50-50 wt. %) alloy mixed with Al2O3 (1-4 wt. %) as micro-particles reinforcement materials. The attained composite alloy specimens\u27 characteristics were estimated such as microstructure, relative density, electrical and thermal conductivity, hardness, and compression yield stress properties to adjust the suitable optimum percentage of reinforcing material which has the best physical and mechanical properties with different main matrix materials whether pure Cu powder or Cu-Ni mechanical alloy. The micron-sized Al2O3 was added to enhance the mechanical and physical properties of the pure Cu and Cu-Ni alloy composites. The electrical and thermal conductivity for pure Cu alloy composites were improved compared to the copper-nickel alloy matrix composites material. The hardness and compression yield stress of pure copper has enhancement values and for Cu-Ni alloy composites have enhancement values and for Cu-Ni base composites, hardness and compression yield stress have improved with the most positive enhancement values

Adherence to Drug-Refill Is a Useful Early Warning Indicator of Virologic and Immunologic Failure among HIV Patients on First-Line ART in South Africa

Affordable strategies to prevent treatment failure on first-line regimens among HIV patients are essential for the long-term success of antiretroviral therapy (ART) in sub-Saharan Africa. WHO recommends using routinely collected data such as adherence to drug-refill visits as early warning indicators. We examined the association between adherence to drug-refill visits and long-term virologic and immunologic failure among non-nucleoside reverse transcriptase inhibitor (NNRTI) recipients in South Africa.In 2008, 456 patients on NNRTI-based ART for a median of 44 months (range 12-99 months; 1,510 person-years) were enrolled in a retrospective cohort study in Soweto. Charts were reviewed for clinical characteristics before and during ART. Multivariable logistic regression and Kaplan-Meier survival analysis assessed associations with virologic (two repeated VL>50 copies/ml) and immunologic failure (as defined by WHO).After a median of 15 months on ART, 19% (n = 88) and 19% (n = 87) had failed virologically and immunologically respectively. A cumulative adherence of <95% to drug-refill visits was significantly associated with both virologic and immunologic failure (p<0.01). In the final multivariable model, risk factors for virologic failure were incomplete adherence (OR 2.8, 95%CI 1.2-6.7), and previous exposure to single-dose nevirapine or any other antiretrovirals (adj. OR 2.1, 95%CI 1.2-3.9), adjusted for age and sex. In Kaplan-Meier analysis, the virologic failure rate by month 48 was 19% vs. 37% among adherent and non-adherent patients respectively (logrank p value = 0.02).One in five failed virologically after a median of 15 months on ART. Adherence to drug-refill visits works as an early warning indicator for both virologic and immunologic failure

Physiotherapeutic protocol and ZnO nanoparticles: a combined novel treatment program against bacterial pyomyositis

Myositis tropicans or pyomyositis is a muscle inflammation resulting from a bacterial infection of skeletal muscle (commonly caused by Staphylococcus aureus) that usually leads to hematogenous muscle seeding. The present study was designed to estimate the role of ZnO-NPs and a physiotherapeutic program in the management of induced biceps femoris atrophy in rats through histological, biochemical, and radiological examinations at different time intervals. At the beginning, several bacterial strains were evaluated through a proteolytic enzyme activity assay and the highest activity was recorded with the Staphylococcus aureus strain. ZnO-NPs were synthesized with the arc discharge method with an average size of 19.4 nm. The antibacterial activity of ZnO-NPs was investigated and it was revealed that the prepared ZnO-NPs showed a minimum inhibitory concentration of 8 µg/mL against the tested bacterium. The cytotoxicity of the prepared ZnO-NPs was tested in C2C12 myoblast cells, and it was elaborated that CC50 was 344.16 µg/mL. Biceps femoris pyomyositis was induced with a potent strain (Staphylococcus aureus); then, a physiotherapeutic program combined with the prepared ZnO-NPs treatment protocol was applied and evaluated. The combined program claimed antibacterial properties, preventing muscle atrophy, and resulted in the most comparable value of muscle mass

Kinetic investigation of hydroxide ion and DNA attack on some high spin iron (II) chelates Bearing ONO Donors amino acid Schiff bases

The reactivity of few novel high spin Fe(II) complexes of Schiff base ligands derived from 2-hydroxynaphthaldehyde and some variety of amino acids with OH- ion has been examined in aqueous mixture at temperature in the range 10–40 Co. Based on the kinetic investigations, the rate law and a plausible mechanism were proposed and discussed. The general rate equation was suggested as follows: rate = kobs [Complex], where kobs.= k1 + k2 [OH-]. Base catalyzed hydrolysis kinetics measurements imply pseudo-first order doubly stage rates due the presence of merand fac-isomers. The observed rate constants kobs are correlated the effect of substituent R in the structure of the ligands. From the effect of temperature on the rate; various thermodynamic parameters have been evaluated. The evaluated rate constants and activation parameters are in a good agreement with the stability constants of the investigated complexes

Bridging the gap between molecular and elemental mass spectrometry: Higher energy collisional dissociation (HCD) revealing elemental information

Molecular mass spectrometry has been applied to simultaneously obtain molecular and elemental information from metal-containing species. Energy tuning of the higher-energy collision dissociation (HCD) fragmentation cell allows the controlled production of typical peptide fragments or elemental reporter ions informing about the metallic content of the analyzed species. Different instrumental configurations and fragmentation techniques have been tested, and the efficiency extracting the elemental information has been compared. HCD fragmentation operating at very high energy led to the best results. Platinum, lanthanides, and iodine reporter ions from peptides interacting with cisplatin, peptides labeled with lanthanides-MeCAT-IA, and iodinated peptides, respectively, were obtained. The possibility to produce abundant molecular and elemental ions in the same analysis simplifies the correlation between both signals and open pathways in metallomics studies enabling the specific tracking of metal-containing species. The proposed approach has been successfully applied to in solution standards and complex samples. Moreover, interesting preliminary MALDI-imaging experiments have been performed showing similar metal distribution compared to laser ablation (LA)-ICPMS

Optimizing the gamma-ray shielding behaviors for polypropylene using lead oxide: A detailed examination

In the current study, the PbO compound was used in order to optimize the gamma-ray shielding properties of the polypropylene polymers. A series of polypropylene doped PbO were performed using various PbO concentrations varied between 0 and 50 wt%. The experimental measurement for the density of the fabricated sample showed that the samples' density varied between 0.902 ± 0.004 and 1.645 ± 0.007 g/cm3, raising the PbO doping concentration between 0 wt% and 50 wt%. Furthermore, the scanning electron microscope was utilized to illustrate the distribution and morphology of the fabricated polypropylene doped PbO concentrations. The gamma-ray shielding capacity of the fabricated polypropylene doped PbO was examined and evaluated experimentally using a sodium iodide scintillation detector and different point sources in the gamma-ray energy interval between 0.059 and 1.408 MeV. The experimental results were affirmed via the Geant4 code, which depended on the Monte Carlo simulation. The difference recorded between the experimental and Geant4 calculations for the fabricated samples shielding properties was lies in between ±4%. The recorded linear attenuation coefficient at gamma-ray energy of 0.244 MeV varied between 0.1148 and 0.5837 cm-1, raising the PbO doping concentration between 0 wt% and 50 wt%. Moreover, the half-value thickness decreased with increasing the PbO doping ratio. © 2022 The Author(s)

Correlation of the GC-MS-based metabolite profile of Momordica charantia fruit and its antioxidant activity

Momordica charantia or bitter melon (Cucurbitaceae) is a widely consumed edible fruit with strong antioxidant properties. Due to these properties, it has been commercialised by the natural product industries as a coadjutant in the treatment of various ailments attributable to the deleterious effects of oxidants. The present work aimed to evaluate the antioxidant activity of M. charantia fruit extracts made with different compositions of ethanol:water, and to identify the metabolites that are responsible for this activity. To this end, the fruit samples were extracted using six different concentrations of ethanol in water (0, 20, 40, 60, 80, and 100%). Gas chromatography-mass spectrometry (GC-MS) and multivariate data analysis (MVDA) were used to identify significant antioxidants. The 80% ethanol:water extract showed the most significant (p < 0.05) antioxidant activity when tested with the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) antioxidant assays. The multivariate data analysis revealed that the metabolites related to this antioxidant activity were gentiobiose, glucose, galactonic acid, palmitic acid, galactose, mannose, and fructose

Perforated carcinoma of the caecum presenting as necrotising fasciitis of the abdominal wall, the key to early diagnosis and management

BACKGROUND: Necrotising Fasciitis is a life threatening soft tissue infection which requires aggressive, early surgical management. CASE PRESENTATION: We present a rare case of a retroperitoneal perforation of a carcinoma of the caecum presenting as a necrotising fasciitis of the anterior abdominal wall. CONCLUSION: This case highlights the importance of early aggressive debridement to healthy tissue limits, the consideration of a rare underlying cause, and the scope for plastic surgical reconstruction in order that aggressive initial surgery can be adequately performed