Synthesis and optical properties of polyvinylidene difluoride nanocomposites comprising MoO3/g-C3N4

The present study describes the optical properties for prepared polymer nanocomposites of PVDF at different content of MoO3/g-C3N4. The structural properties of polymer films were analysed via XRD, FTIR and ESEM techniques. The XRD diffraction patterns of PVDF with different concentrations of MoO3/g-C3N4 have two characteristic peaks at 2 θ = 18.4° and 20.3° where first peak was assigned to α-phase, while last peak was attributed to β-phase. The ESEM micrographs of PVDF-MoO3/g-C3N4 nanocomposites have shown smooth surface topography. According to the UV–visible absorption spectra, the UV absorption of PVDF was increased when adding MoO3/g-C3N4 nanoparticles where distinct peak was appeared in the UV region at 310 nm and its edges become more intense and moved towards higher wavelength after MoO3/g-C3N4 incorporation. The optical values of (Edir) and (Eind) energies have decreased with increasing the nanoparticle composites content. The optical band gap energy (Eopt) was decreasing from 5.66 eV to 4.56 eV as increasing the content of MoO3/g-C3N4. The refractive index (n) was increased with increasing the concentration of MoO3/g-C3N4 in nanocomposites samples, except for the sample with 0.25 wt%. The distinctive optical characteristics of PVDF-MoO3/g-C3N4 qualify such polymer nanocomposites for optoelectronic applications

Insight into possible therapeutic applications of Ephedra transitoria: in-vitro biological, toxicological activities and GC-MS analysis of aerial parts’ extract

Most Arab nations have arid regions where Ephedra transitoria, a plant, flourishes. It has a variety of medical benefits. It belongs to the Ephedraceae family. The plant's aerial portions were procured from the Hail region of Saudi Arabia, methanol was used to extract bioactive phytochemicals with variable solubility in an efficient manner, and the resulting extract was tested on several cancer cell lines. The extract's cytotoxic potential was measured by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay method against standard vinblastine sulfate and for each cell line, the pertinent half maximal inhibitory concentration values were calculated. Additional apoptosis assays were conducted. Also, the antioxidant activity of plant extract was examined using 2, 2-Diphenyl-1-picrylhydrazyl and [2, 2’-azinobis-(3-ethylbenzothiazoline-6-sulfonate)] methods compared to ascorbic acid standard. Also, antimicrobial effect of extract was evaluated on different gram positive and gram-negative bacteria by zone inhibition and minimum inhibitory concentration assay methods. GC-MS analysis was further applied to identify major bioactive substances. Extract showed good cytotoxic activity against both lung and liver cancer cells with relevant half maximal inhibitory concentration values comparable to those of standard. Extract resulted in S-phase arrest, primarily via inducing apoptosis mediated through activating caspase-3, Bax, and p53 proteins. Plant extract showed good antibacterial activities against S. aureus, E. coli and B. subtilis. Also, it showed high antioxidant activity with relevant half maximal inhibitory concentration values comparable to those of standard. Some bioactive compounds were separated and identified by GC-MS analysis such as; ephedrine and quercetin. ephedra transitoria extract possess high cytotoxic activity against lung and liver cancer cells via S-phase arrest mediated by activation of apoptotic proteins. It also possesses high antioxidant and antibacterial activities

The relationship between work readiness and perceived clinical competence among graduates transitioning into professional practice

Background: Nursing Residency Programs (NRPs) reportedly help close the disparities in job-related knowledge, expertise, and attitudes that affect new nurses, healthcare organizations, and care quality by offering instructions and resources for new graduate nurses. Aim: This study aims to explore the relationship between work readiness and perceived clinical competence among graduates attending the NRP as compared to nurse interns at one university hospital. Methods: This study employed a quantitative cross-sectional research design, recruiting 203 graduate nurses through a purposive sampling technique via electronic invitations. Results: The results of this study showed that graduates attending the NRP had higher scores at all levels of work readiness and clinical competence, with work readiness being found as a predictor of clinical competence. Conclusions: Healthcare organizations are responsible for exploring the transition to practice programs and their effectiveness in enhancing work readiness to increase the quality of care offered to patients and to prepare skillful new graduates for professional and safe practice

Vitamin D deficiency in Saudi Arabians: A reality or simply hype: A meta-analysis (2008-2015)

BACKGROUND AND OBJECTIVE: The objective of this systematic review was to determine from published data the prevalence of Vitamin D deficiency in the Saudi population. METHODS: An extensive and meticulous search was conducted for studies published in MEDLINE, EMBASE the Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews (2008”2015), and the Science Citation Index published data from the Annals of Saudi Medicine and Saudi Medical Journal with the key words: Vitamin D deficiency, insufficiency, and Saudi Arabians. The inclusion criterion was studies published during 2008 to 2015, and studies involving healthy individuals between the age of 18 and 80 years. Binary random- effect model was used to estimate pooled Vitamin D deficiency. Prevalence rates along with overall estimate were presented by forest plot. Heterogeneity test was used to assess the significance of heterogeneity among studies. RESULTS: The authors identified 26 potentially relevant articles, 16 of which met the inclusion criteria. A total of 20,787 patients were analyzed. Sixty-two percent (12,959) were females, and the rest were males. The overall Vitamin D deficiency was 63.5% (95% CI: 53.3, 73.7). CONCLUSIONS: The currently available literature on the Saudi Arabian population suggests that the Vitamin D deficiency is around 60% and not 100% as indicated in some studies. The relatively small number of studies on the population and the different modes of diagnostic methodology used make the issue of correct figures of Vitamin D deficiency contentious

Prisoners of Image : Ethnic and Gender Stereotypes

Five essayists address imagery created by white Westerners which enforce discriminatory stereotypes and condones racism. Statements by some of the 12 exhibiting artists whose work denounces such stereotypes. Notes on contributors. 4 bibl. ref

Inhalable, Spray-Dried Terbinafine Microparticles for Management of Pulmonary Fungal Infections: Optimization of the Excipient Composition and Selection of an Inhalation Device

Terbinafine is a broad-spectrum antifungal agent with therapeutic potential against pulmonary aspergillosis. The main aim of the current study was to investigate the potential of l-leucine, alone and in combination with mannitol, to improve the performance of spray-dried terbinafine microparticles for inhalation. The study also aimed to investigate the potential of the low resistance Cyclohaler® and the high resistance Handihaler® as inhalation devices for spray-dried microparticles. To this end, eight powder inhalation formulations of terbinafine were prepared by nano spray drying via a factorial experimental design. The formulations were evaluated in vitro for their potential to deliver the antifungal drug to the lungs using the Cyclohaler® and the Handihaler®. Leucine was superior as an excipient to mannitol and to mixtures of leucine and mannitol. Using leucine as an excipient resulted in formulations with fine particle fractions of up to 60.84 ± 0.67% w/w and particle mass median aerodynamic diameters of down to 1.90 ± 0.20 μm, whereas using mannitol as an excipient resulted in formulations with fine particle fractions of up to 18.75 ± 3.46% w/w and particle mass median aerodynamic diameters of down to 6.79 ± 0.82 μm. When leucine was used as an excipient, using 50% w/w rather than 25% w/w ethanol in water as a spray solvent enhanced the dispersibility of the particles, with a mean absolute increase in the formulation fine particle fraction of 9.57% w/w (95% confidence interval = 6.40–12.73% w/w). This was potentially underlain by enrichment of the particle surfaces with leucine. The Cyclohaler® outperformed the Handihaler® as an inhalation device for the developed formulations, with a mean absolute increase in the fine particle fraction of 9.17% w/w (95% confidence interval = 8.17–10.16% w/w)

Preparation and Optical Properties of PVDF-CaFe₂O₄ Polymer Nanocomposite Films

In this work, a synthesis technique for highly homogeneous PVDF-CaFe2O4 polymer films direct from solution was developed. The structural characterizations were conducted using XRD, FTIR, and ESEM experimental techniques. The XRD characteristic peaks of CaFe2O4 nanoparticles revealed a polycrystalline structure. The average crystallite size for CaFe2O4 was calculated to be 17.0 nm. ESEM micrographs of PVDF nanocomposites containing 0.0, 0.25, 0.75, and 1.0 wt% of CaFe2O4 showed smooth surface topography. The direct Edir and indirect Eind band gap energies for the PVDF-CaFe2O4 nanocomposites were decreased with the additions of 0.0–1.0 wt% CaFe2O4. In addition, the refractive index (n0) increased from 3.38 to 10.36, and energy gaps (Eg) decreased from 5.50 to 4.95 eV. The nonlinear refractive index (n2) for the PVDF-CaFe2O4 nanocomposites was improved with the addition of CaFe2O4 nanoparticles, exceeding those reported in the literature for PVC, PVA, and PMMA nanocomposites. Therefore, the PVDF-CaFe2O4 nanocomposites are expected to take the lead in optoelectronic applications because of their unusual optical properties

Assessment of urothelial cells atypical changes among petroleum station workers in Saudi Arabia

The aim of the present study was to assess atypical changes in urothelial cells among petroleum station workers. This is a case control study, investigating 300 participants by cytological methods. Of the 300 participants, 150 were cases (exposed to petroleum products) and 150 were controls (non-exposed). Full voided urine was obtained and was cytologically assessed. Cytological atypia was identified in nine (6%) out of the 150 cases and could not be identified in 141/150 (94%) of the cases, whereas, in the control group, cytological atypia was recognized in four (2.7%) of the 150 controls and could not be identified in 146/150 (97.3%). The risk associated with petroleum product exposure, the odds ratio (OR), and 95% confidence interval (CI) was 2.33 (0.7015–7.7378), P = 0.1673. Exposure of petroleum station workers to petroleum products increases the risk of urothelial atypical changes, which may progress to precancerous and cancerous changes