Work related injuries in Qatar: a framework for prevention and control

Work related injuries (WRIs) are a growing public health concern that remains under-recognized, inadequately addressed and largely unmeasured in low and middle-income countries (LMIC’s). However, even in high-income countries, such as those in Gulf Cooperating Council (GCC) like Qatar, there are challenges in assuring the health and safety of its labor population. Countries in the GCC have been rapidly developing as a result of the economic boom from the petrochemical industry during the early seventies. Economic prosperity has propelled the migration of workers from less developed countries to make up for the human resource deficiency to develop its infrastructure, service and hospitality industries. Although these countries have gradually made huge gains in health, economy and human development index, including improvements in life expectancy, education, and standard of living, there remains a high incidence of work-related injuries especially in jobs in the construction and petrochemical sector. Currently, there is scarcity of literature on work-related injuries, especially empirical studies documenting the burden, characteristics and risk factors of work injuries and the work injured population, which includes large numbers of migrant workers in many GCC countries. This paper will focus on the current understanding of WRIs in those countries and identify the gaps in current approaches to workplace injury prevention, outlining current status of WRI prevention efforts in Qatar, and propose a framework of concerted action by multi-sectoral engagement.     

Long-term effect of hand-arm vibration on thermotactile perception thresholds

Background

Occupational exposure to hand-transmitted vibration (HTV) is known to cause neurological symptoms such as numbness, reduced manual dexterity, grip strength and sensory perception. The purpose of this longitudinal study was to compare thermotactile perception thresholds for cold (TPT_C) and warmth (TPT_W) among vibration exposed manual workers and unexposed white collar workers during a follow-up period of 16 years to elucidate if long-term vibration exposure is related to a change in TPT over time.

Methods

The study group consisted of male workers at a production workshop at which some of them were exposed to HTV. They were investigated in 1992 and followed-up in 2008. All participants were physically examined and performed TPT bilaterally at the middle and distal phalanges of the second finger. Two different vibration exposure dosages were calculated for each individual, i.e. the individual cumulative lifetime dose (mh/s²) or a lifetime 8-h equivalent daily exposure (m/s²).

Results

A significant mean threshold difference was found for all subjects of about 4–5 °C and 1–2 °C in TPT_W and TPT_C, respectively, between follow-up and baseline. No significant mean difference in TPT_C between vibration exposed and non-exposed workers at each occasion could be stated to exist. For TPT_W a small but significant difference was found for the right index finger only. Age was strongly related to thermotactile perception threshold. The 8-h equivalent exposure level (A (8)) dropped from about 1.3 m/s² in 1992 to about 0.7 m/s² in 2008.

Conclusions

A lifetime 8-h equivalent daily exposure to hand-transmitted vibration less than 1.3 m/s² does not have a significant effect on thermotactile perception. Age, however, has a significant impact on the change of temperature perception thresholds why this covariate has to be considered when using TPT as a tool for health screening.

     

Development and validation of UPLC-PDA method for concurrent analysis of bergenin and menisdaurin in aerial parts of Flueggea virosa (Roxb. ex Willd.)

Bergenin and menisdaurin are biologically active components which are found in plant Flueggea virosa (Phyllanthaceae). Bergenin has pharmacological actions such as chemopreventive and antihepatotoxic while menisdaurin has an anti-viral activity which needs its evaluation by an analytical method (UPLC-PDA method) that can be applied to the quality control of pharmaceutical preparations. The developed UPLC-PDA method was applied for identification and quantification of standards bergenin and menisdaurin in the methanol extract of F. virosa (FVME). The analysis was carried out using Eclipse C18 (4.6?×?100?mm, 3.5?µm) UPLC column. The optimized chromatographic condition was achieved at 0.16?mL/min flow rate using gradient system with acetonitrile and water as mobile phase. Both biomarkers were measured at λ_max 235?nm in PDA detector at ambient temperature. The developed method furnished sharp and intense peaks of menisdaurin and bergenin at Rt?=?2.723 and 3.068?min, respectively along with r2?>?0.99 for both. The recoveries of bergenin and menisdaurin were found in the range of 99.37–101.49% and 98.20–100.08%, respectively. With other validation data, including precision, specificity, accuracy, and robustness, this method demonstrated excellent reliability and sensitivity. The separation parameters i.e. retention, separation, and resolution factors for resolved standards (bergenin and menisdaurin) were >1, which showed good separation. The quantity of bergenin and menisdaurin in the FVME sample was found as 15.16 and 3.28% w/w, respectively. The developed UPLC-PDA method could be conveniently adopted for the routine quality control analysis.     

Predisposing factors for erectile dysfunction and response to treatment in younger males: Are they different from those of older men? An observational-comparative study

We aimed to correlate the predisposing demographic and clinical factors for erectile dysfunction (ED) in young men and treatment response in these men with data from older men. The patients were divided into two groups: <40 years (group I, n = 58) and ≥40 years (group II, n = 73). ED was evaluated with the International Index of Erectile Function-5 (IIEF-5) questionnaire, and Beck's Depression Inventory (BDI) questionnaire was used to evaluate mood status. The number of patients with morning rigidity and normal libido was higher in group I (70.7% vs. 16.4%, p = .039 and 72% vs. 37%, p = .047). The increase in scores other than IIEF-Orgasmic Function and Sexual Desire domain scores after treatment was higher in the first group (p = .029, p = .035 and p < .001 respectively). In multivariate analysis, the factors predicting the low IIEF-Erectile Function domain score in young men were testosterone level and BDI score (p = .026 and p = .034). Although psychogenic factors contribute significantly to the aetiology of ED, hormone profile is more preserved in young men than in older men.     

Synthesis of water soluble copper(II) complexes: crystal structures,DNA binding,oxidative DNA cleavage,and in vitro anticancer studies

Two ternary copper(II) complexes of dl-threonine and polypyridyl ligands with formula of [Cu(Thr)(Byp)Cl]·H₂O (1) and [Cu(Thr)(Phen)H₂O]Cl·2H₂O (2) were synthesized. The complexes were characterized by spectral (NMR, FT-IR, and UV–Vis), CHN elemental analysis and have been structurally elucidated by X-ray crystallography. Both of the complexes formed slightly distorted square-pyramidal coordination geometry. The electronic absorption spectra of the complexes showed a very low intensity d–d electronic band in the range of 610–620 nm in Tris–HCl/NaCl (5:5 mM) pH 7.2 buffer solution. The DNA binding interaction with calf-thymus DNA (CT-DNA) was investigated by electronic absorption spectral titration and viscosity measurements. The results revealed that the phenanthroline complex (2) interact with CT-DNA through intercalation while bipyridyl complex (1) through the groove binding mode. The calculated intrinsic binding constant (K _b) of (1) and (2) were 0.5 and 4.4 × 10⁵ M^?1, respectively. Both the complexes were found to promote efficient DNA cleavage activities at low concentration in the presence of H₂O₂. The results showed that (2) has the highest DNA binding and nuclease activity. Furthermore, both the complexes were tested against human colon cancer (HCT 116) and breast cancer (MCF-7) cell lines and showed a dose-dependent antiproliferation effect.     

Lower vitamin D level is associated with poor coronary collateral circulation

Objectives. Vitamin D regulates calcium and bone homeostasis, and parathyroid hormone (PTH) secretion. Cross-sectional associations between lower vitamin D levels and cardiovascular diseases have been reported, but the relationship between vitamin D levels and collateral arteries in stable coronary artery disease (CAD) has not been reported before. Design. Two hundred and fourteen patients with above 95% stenosis in at least one epicardial coronary artery were consecutively recruited after coronary angiography (CAG) during the winter season. The coronary collateral circulation (CCC) was graded using Rentrop classification. Poor CCC group included patients with Rentrop Grade 0–1 CCC and control group included patients with Rentrop Grade 2–3 CCC. Vitamin D and PTH levels were measured on the day of CAG. Results. In the poor CCC group, vitamin D levels were lower (34 ± 25 pmol/L vs. 49 ± 33 pmol/L; p = 0.01) and the prevalence of vitamin D deficiency (< 37 pmol/L) was higher (67% vs. 43%; p = 0.01) compared to the controls. PTH levels, calcium, and phosphate levels were not significantly different between the groups. Female gender, lower HDL cholesterol, and lower vitamin D levels were independently correlated with poor CCC in the study population. Conclusion. Lower vitamin D levels may be associated with poor collateral development in patients with stable CAD.     

Effect of Silicon Nitride and Graphene Nanoplatelets on the Properties of Aluminum Metal Matrix Composites

This research work aims at investigating the influence of a fixed content of silicon nitride (Si₃N₄) and varied contents of graphene nanoplatelets (GNPs) on the physical (density, structural, morphological) and mechanical properties (microhardness, nanoindentation) of Al-Si₃N₄-GNPs composites. The composites were fabricated by a microwave-assisted powder metallurgy route. The Si₃N₄ concentration was fixed at (5 wt.%) in Al-Si₃N₄-GNPs composites while the GNPs concentration was varied between (0 wt.%) to (1.5 wt.%) with an increment of (0.5 wt.%). The structural analysis indicates the formation of phase pure materials with high crystallinity. The microstructural analysis confirmed the presence of the Si₃N₄ and GNPs showing enhanced agglomeration with the increasing amount of GNPs. Moreover, the surface roughness of the synthesized composites increases with an increasing amount of GNPs reaching its maximum value (RMS = 65.32 nm) at 1.5 wt.% of GNPs. The Al-Si₃N₄-GNPs composites exhibit improved microhardness and promising load-indentation behavior during nanoindentation when compared to pure aluminum (Al). Moreover, Al-Si₃N₄-GNPs composites demonstrate higher values of compressive yield strength (CYS) and ultimate compressive strength (UCS) when compared to pure Al despite showing a declining trend with an increasing amount of GNPs in the matrix. Finally, a shear mode of fracture is prevalent in Al-Si₃N₄-GNPs composites under compression loading.