Effect of Accelerated Weathering on the Thermal, Tensile, and Morphological Characteristics of Polypropylene/Date Nanofiller Composites.

The aging of polypropylene (PP) composites reinforced with date palm nanofiber (DNF) was investigated in this study in order to predict their long-term performance. To produce composites, date palm nanofibers in the range of 1-5 wt% loading were dry-melt-blended with polypropylene. These biocomposites were then subjected to UV exposure (Xenon arch source) for accelerated weathering for 250 and 500 h according to a standard method. The change in thermal properties before and after accelerated weathering was investigated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). TGA analysis shows that the maximum degradation temperature for sample at 1 wt% loading was 382.7 °C, which slightly decreased to 379.9 °C after 250 h and to 367.7 °C after 500 h of weathering. DSC analysis also revealed lower crystallinity of the same samples after exposure to accelerated weathering. Mechanical properties were also studied to identify the damage induced by accelerated weathering. The tensile strength of the highest loading (5 wt%) of the sample was found to occur at 34.83 MPa, which was slightly lowered to 31.64 after 500 h treatment. A minimal decrease in tensile strength, deterioration, and weathering-induced oxidation indicates the excellent stability of these composites. Therefore, our study provides insight into the aging behavior of such composites, which may be useful in dry conditions, as well as nonstructural automotive and other parts for which minimum tensile strength (~25 MPa) is specified.

Evaluation of the Effect of Recycled Polypropylene as Fine Aggregate Replacement on the Strength Performance and Chloride Penetration of Mortars.

Nowadays, the re-use and recycling of industrial wastes to reduce the environmental impact and landfill problems are the main concerns of researchers. Plastics are one of the main waste materials worldwide, with considerable impacts on health and environmental conditions. Recycling plastic wastes in the concrete industry is one of the adopted ways to reduce such impact and increase the economic recyclability of plastics. In this study, the utilization of recycled polypropylene (rPP) as a fine aggregate in the preparation of cement mortars was evaluated. The river sand was replaced with 10, 20, 30, 40, and 50%, volumes of rPP. The results showed that the inclusion of rPP reduced the mortar's workability and fresh density. Fresh density dropped from 11% to 35% as the rPP content increased. Furthermore, the compressive strength at early and late age was significantly influenced by the rPP content. At 28 days of curing age, the results showed that the inclusion of 50% of rPP in the mortar matrix led to a drop in the compression strength from 40 MPa to 10 MPa. A similar trend of results was obtained for the flexural (from 8.3 MPa to 2.9 MPa) and tensile strengths (from 3.4 MPa to 1.21 MPa). The chloride ion penetration went through a maximum of 5000 Coulombs between 10% and 50 % of rPP. Therefore, it can be concluded that the use of 10% of rPP as a river sand replacement can achieve acceptable strength (25 MPa) for several applications in the construction industry.

Facile Synthesis of Hydrophilic Homo-Polyacrylamides via Cu(0)-Mediated Reversible Deactivation Radical Polymerization.

In this work, copper-mediated reversible deactivation radical polymerization (RDRP) of homo-polyacrylamides was conducted in aqueous solutions at 0.0 °C. Various degrees of polymerization (DP = 20, 40, 60, and 80) of well-defined water-soluble homopolymers were targeted. In the absence of any significant undesirable side reactions, the dispersity of polydiethylacrylamide (PDEA) and polydimethylacrylamide (PDMA) was narrow under controlled polymerization conditions. To accelerate the polymerization rate, disproportionation of copper bromide in the presence of a suitable ligand was performed prior to polymerization. Full conversion of the monomer was confirmed by nuclear magnetic resonance (NMR) analysis. Additionally, the linear evolution of the polymeric chains was established by narrow molecular weight distributions (MWDs). The values of theoretical and experimental number average molecular weights (Mn) were calculated, revealing a good matching and robustness of the system. The effect of decreasing the reaction temperature on the rate of polymerization was also investigated. At temperatures lower than 0.0 °C, the controlled polymerization and the rate of the process were not affected.

Effects of Nanoclay on Mechanical and Dynamic Mechanical Properties of Bamboo/Kenaf Reinforced Epoxy Hybrid Composites.

Current work aims to study the mechanical and dynamical mechanical properties of non-woven bamboo (B)/woven kenaf (K)/epoxy (E) hybrid composites filled with nanoclay. The nanoclay-filled BK/E hybrid composites were prepared by dispersing 1 wt.% nanoclay (organically-modified montmorillonite (MMT; OMMT), montmorillonite (MMT), and halloysite nanotube (HNT)) with high shear speed homogenizer followed by hand lay-up fabrication technique. The effect of adding nanoclay on the tensile, flexural, and impact properties of the hybrid nanocomposites were studied. Fractography of tensile-fractured sample of hybrid composites was studied by field emission scanning electron microscope. The dynamic mechanical analyzer was used to study the viscoelastic properties of the hybrid nanocomposites. BK/E-OMMT exhibit enhanced mechanical properties compared to the other hybrid nanocomposites, with tensile, flexural, and impact strength values of 55.82 MPa, 105 MPa, and 65.68 J/m, respectively. Statistical analysis and grouping information were performed by one-way ANOVA (analysis of variance) and Tukey method, and it corroborates that the mechanical properties of the nanoclay-filled hybrid nanocomposites are statistically significant. The storage modulus of the hybrid nanocomposites was improved by 98.4%, 41.5%, and 21.7% with the addition of OMMT, MMT, and HNT, respectively. Morphology of the tensile fracture BK/E-OMMT composites shows that lesser voids, microcracks and fibers pull out due to strong fiber-matrix adhesion compared to other hybrid composites. Hence, the OMMT-filled BK/E hybrid nanocomposites can be utilized for load-bearing structure applications, such as floor panels and seatbacks, whereby lightweight and high strength are the main requirements.

ABC-Type Triblock Copolyacrylamides via Copper-Mediated Reversible Deactivation Radical Polymerization.

The aqueous Cu(0)-mediated reversible deactivation radical polymerization (RDRP) of triblock copolymers with two block sequences at 0.0 °C is reported herein. Well-defined triblock copolymers initiated from PHEAA or PDMA, containing (A) 2-hydroxyethyl acrylamide (HEAA), (B) N-isopropylacrylamide (NIPAM) and (C) N, N-dimethylacrylamide (DMA), were synthesized. The ultrafast one-pot synthesis of sequence-controlled triblock copolymers via iterative sequential monomer addition after full conversion, without any purification steps throughout the monomer additions, was performed. The narrow dispersities of the triblock copolymers proved the high degree of end-group fidelity of the starting macroinitiator and the absence of any significant undesirable side reactions. Controlled chain length and extremely narrow molecular weight distributions (dispersity ~1.10) were achieved, and quantitative conversion was attained in as little as 52 min. The full disproportionation of CuBr in the presence of Me6TREN in water prior to both monomer and initiator addition was crucially exploited to produce a well-defined ABC-type triblock copolymer. In addition, the undesirable side reaction that could influence the living nature of the system was investigated. The ability to incorporate several functional monomers without affecting the living nature of the polymerization proves the versatility of this approach.

Characterization of Microcrystalline Cellulose Isolated from Conocarpus Fiber.

Conocarpus fiber is an abundantly available and sustainable cellulosic biomass. With its richness in cellulose content, it is potentially used for manufacturing microcrystalline cellulose (MCC), a cellulose derivative product with versatile industrial applications. In this work, different samples of bleached fiber (CPBLH), alkali-treated fiber (CPAKL), and acid-treated fiber (CPMCC) were produced from Conocarpus through integrated chemical process of bleaching, alkaline cooking, and acid hydrolysis, respectively. Characterizations of samples were carried out with Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), Fourier Transform Infrared-Ray (FTIR), X-ray Diffraction (XRD), Thermogravimetric (TGA), and Differential Scanning Calorimetry (DSC). From morphology study, the bundle fiber feature of CPBLH disintegrated into micro-size fibrils of CPMCC, showing the amorphous compounds were substantially removed through chemical depolymerization. Meanwhile, the elemental analysis also proved that the traces of impurities such as cations and anions were successfully eliminated from CPMCC. The CPMCC also gave a considerably high yield of 27%, which endowed it with great sustainability in acting as alternative biomass for MCC production. Physicochemical analysis revealed the existence of crystalline cellulose domain in CPMCC had contributed it 75.7% crystallinity. In thermal analysis, CPMCC had stable decomposition behavior comparing to CPBLH and CPAKL fibers. Therefore, Conocarpus fiber could be a promising candidate for extracting MCC with excellent properties in the future.

Doped SnO2 Nanomaterials for E-Nose Based Electrochemical Sensing of Biomarkers of Lung Cancer.

Lung cancer detection includes detection of a pattern formed by multiple volatile organic compounds. An individual material has limited selectivity and hence requires tailoring to improve the selectivity and sensing properties. An electronic nose (e-nose) is a concept/device that can help in achieving selectivity and specificity for multiple volatile organic compounds at the same time by using an array of sensors. In this paper, Co and Ni doping in tin oxide was used to investigate as a sensor material for e-nose development. These were synthesized using a sol-gel method and were characterized for structural, morphological, and elemental assessment using X-ray diffraction, field emission scanning electron microscopy, and Fourier transform infrared spectroscopy, which indicated the formation of the composite nanomaterial of SnO2. These synthesized materials were then used as a working electrode in the form of a screen-printed electrode to determine 1-propanol and isopropyl alcohol (IPA) sensing characteristics. Electrochemical characterization was done by cyclic voltammetry (CV) and electrochemical impedance spectroscopy. In the case of CV studies, well-defined and distinct redox peaks are observed at different potential values indicating the changes due to the dopants. Ni doping in SnO2 shows the highest sensitivity of 2.99 µA/ppb for isopropyl alcohol and 3.11 for 1-propanol, within the detection range. Furthermore, Co-SnO2 shows selectivity for IPA, while Ni-SnO2 is selective to 1-propanol against all other volatile compounds analyzed.

Thymolipoma Association with Myasthenia Gravis: Case Report.

BACKGROUND Thymolipoma, which was described initially by Hall in 1949, is an uncommon benign thymic tumor that represents around 9% of all thymic tumors. The incidence of thymolipoma is around 0.12 out of 100 000 cases per year, with a higher incidence in the younger age population. Thymolipoma incidence has been linked to different autoimmune diseases, including myasthenia gravis, in half of the reported cases. There are 34 reported cases in the literatures documenting such a relationship between thymolipoma and myasthenia gravis. The exact pathogenesis is unclear. However, some genetic findings revealed the presence of myoid cells, which might play a vital role in this association. CASE REPORT A 56-years-old female known to have myasthenia gravis presented to the Emergency Department with acute congestive heart failure, atrial fibrillation, and stroke secondary to infected vegetation from the mitral valve. The patient underwent a semi-urgent mitral valve replacement surgery treating her cardiac presentation along with an extended thymectomy to control her myasthenia gravis disease. The final histopathological assessment of the removed thymus revealed a thymolipoma pathology. CONCLUSIONS The possibility of thymolipoma as an anterior mediastinal mass should be kept in mind when dealing with an older age group of myasthenia gravis patients on steroids. Concomitant heart surgery and thymectomy are feasible, and extended thymectomy is the treatment of choice for thymolipoma in myasthenia gravis patients with a better complete remission rate after resection. However, further comparative studies are needed for a more reliable conclusion of the postoperative myasthenia gravis response after resection.

Characterization of Date Palm Fiber-Reinforced Different Polypropylene Matrices.

In this study, the effect of different polypropylene (PP) matrices (homopolymer (HPP), impact copolymer (ICP), and recycled polypropylene (rPP)) on the mechanical, morphological, and thermal properties of date palm fiber (DPF)-reinforced PP composites was investigated. The DPFs were treated with an alkali solution, and composites were fabricated with different DPF loadings (5, 10, and 15 wt %) and lengths (less than 2 mm and 8-12 mm). It was found that the tensile properties of the DPF/ICP and DPF/rPP composites were similar to those of the DPF/HPP composites. The addition of fiber to the matrix reduced its tensile strength but increased the modulus. The alkali treatment improved the compatibility between the fibers and the matrix by removing hemicellulose and other impurities. Fourier transform infrared spectroscopy confirmed hemicellulose removal. The morphology of the alkali-treated fractured tensile specimen revealed improved adhesion and less fiber pull out. Differential scanning calorimetry revealed that the alkali treatment enhanced the crystallinity index. Thermogravimetric analysis showed that the addition of DPFs into the PP matrix reduced the thermal stability of the composite. However, the thermal stability of the treated fiber-reinforced rPP and ICP composites was similar to that of the DPF/HPP composite. Hence, rPP can be used as an alternative to HPP with DPFs.

Thermo-oxidative stability and flammability properties of bamboo/kenaf/nanoclay/epoxy hybrid nanocomposites.

In this study, three types of nanoclay [halloysite nanotube (HNT), montmorillonite (MMT) and organically modified MMT (OMMT)] were incorporated into bamboo/kenaf (B/K) reinforced epoxy hybrid composites to compare their thermo-oxidative (TOD) stability and flammability properties. B/K (50 : 50) hybrid nanocomposites were fabricated by adding 1% loading (by weight) nanoclay through a hand lay-up technique. Wide angle X-ray scattering (WAXS) and field emission scanning electron microscopy (FESEM) were used to study the morphology of the nanoclay-epoxy mixture. The TOD stability of the hybrid nanocomposites was studied with a thermogravimetry analyzer (TGA) under oxygen atmosphere. The flammability properties were evaluated using the Underwriters Laboratories 94 horizontal burning test (UL-94HB), limiting oxygen index (LOI), cone calorimetry and smoke density test. The morphological study reveals that MMT/epoxy and HNT/epoxy are highly agglomerated while OMMT/epoxy reveals a more uniform distribution morphology. The obtained results reveal that B/K/HNT shows better TOD stability below 300 °C, but B/K/MMT and B/K/OMMT show high residue content and decomposition temperatures above 300 °C. The flame retardancy of the hybrid nanocomposites improved with the loading of all types of nanoclay, but B/K/OMMT shows higher flame retardancy than B/K/MMT and B/K/HNT hybrid nanocomposites. Hybrid nanocomposites show improvement in flame properties in terms of peak heat release rate (pHRR), total heat release, fire growth rate index (FIGRA) and maximum average rate of heat emission (MARHE) and smoke growth rate index (SMOGRA) indicators. The findings from this work can be utilized to prepare high-performance fire retardant natural fiber reinforced epoxy hybrid composites for automotive and construction applications to save human lives.

Reduced graphene/nanostructured cobalt oxide nanocomposite for enhanced electrochemical performance of supercapacitor applications.

We demonstrate the preparation of nanostructures cobalt oxide/reduced graphene oxide (Co3O4/rGO) nanocomposites by a simple one-step cost-effective hydrothermal technique for possible electrode materials in supercapacitor application. The X-ray diffraction patterns were employed to confirm the nanocomposite crystal system of Co3O4/rGO by demonstrating the existence of normal cubic spinel structure of Co3O4 in the matrix of Co3O4/rGO nanocomposite. FTIR and FT-Raman studies manifested the structural behaviour and quality of prepared Co3O4/rGO nanocomposite. The optical properties of the nanocomposite Co3O4/rGO have been investigated by UV absorption spectra. The SEM/TEM images showed that the Co3O4 nanoparticles in the Co3O4/rGO nanocomposites were covered over the surface of the rGO sheets. The electrical properties were analyzed in terms of real and imaginary permittivity, dielectric loss and AC conductivity. The electrocatalytic activities of synthesized Co3O4/rGO nanocomposites were determined by cyclic voltammetry and charge-discharge cycle to evaluate the supercapacitive performance. The specific capacitance of 754 Fg-1 was recorded for Co3O4/rGO nanocomposite based electrode in three electrode cell system. The electrode material exhibited an acceptable capability and excellent long-term cyclic stability by maintaining 96% after 1000 continuous cycles. These results showed that the prepared sample could be an ideal candidate for high-energy application as electrode materials. The synthesized Co3O4/rGO nanocomposite is a versatile material and can be used in various application such as fuel cells, electrochemical sensors, gas sensors, solar cells, and photocatalysis.

Evaluation of Mechanical, Physical, and Morphological Properties of Epoxy Composites Reinforced with Different Date Palm Fillers.

The present study deals with the fabrication of epoxy composites reinforced with 50 wt% of date palm leaf sheath (G), palm tree trunk (L), fruit bunch stalk (AA), and leaf stalk (A) as filler by the hand lay-up technique. The developed composites were characterized and compared in terms of mechanical, physical and morphological properties. Mechanical tests revealed that the addition of AA improves tensile (20.60-40.12 MPa), impact strength (45.71-99.45 J/m), flexural strength (32.11-110.16 MPa) and density (1.13-1.90 g/cm3). The water absorption and thickness swelling values observed in this study were higher for AA/epoxy composite, revealing its higher cellulosic content, compared to the other composite materials. The examination of fiber pull-out, matrix cracks, and fiber dislocations in the microstructure and fractured surface morphology of the developed materials confirmed the trends for mechanical properties. Overall, from results analysis it can be concluded that reinforcing epoxy matrix with AA filler effectively improves the properties of the developed composite materials. Thus, date palm fruit bunch stalk filler might be considered as a sustainable and green promising reinforcing material similarly to other natural fibers and can be used for diverse commercial, structural, and nonstructural applications requiring high mechanical resistance.

Characterization of natural fiber obtained from different parts of date palm tree (Phoenix dactylifera L.).

The current study is motivated by the strict environmental regulations regarding the utilization and consumption of ecofriendly materials. In this context, the aim of this study has been to prepare and characterize different date palm tree (Phoenix dactylifera L.) fibers processed through the conventional water retting method. The chemical, elemental, crystallinity, thermal and morphological characterization of trunk (DPTRF), leaf stalk (DPLST), sheath or leaf sheath (DPLSH) and fruit bunch stalk (DPFBS) fibers was carried out. Chemical analysis revealed that the four types of date palm fibers display noteworthy differences in the content of cellulose, hemicellulose and lignin. Also, the amount of calcium is relatively high in all the date palm fibers; besides this, DPTRF exhibited 69.2% crystallinity, which is lower than that of DPLSH with 72.4% crystallinity. Moreover, DPLST and DPFBS fibers are more thermally stable (higher thermal degradation temperature) than DPTRF and DPLSH samples. Morphological analysis revealed that the fracture surface of DPFBS was relatively rougher, which would probably lead to increased bonding strength with polymers in composites. Overall, we conclude that DPFBS would be promising alternative sustainable and biomass material for the isolation of respective cellulose nanofibers and cellulose nanocrystals as potential reinforcement in polymer composites.

Rapid Solar-Light Driven Superior Photocatalytic Degradation of Methylene Blue Using MoS2-ZnO Heterostructure Nanorods Photocatalyst.

Herein, MoS2-ZnO heterostructure nanorods were hydrothermally synthesized and characterized in detail using several compositional, optical, and morphological techniques. The comprehensive characterizations show that the synthesized MoS2/ZnO heterostructure nanorods were composed of wurtzite hexagonal phase of ZnO and rhombohedral phase of MoS2. The synthesized MoS2/ZnO heterostructure nanorods were used as a potent photocatalyst for the decomposition of methylene blue (MB) dye under natural sunlight. The prepared MoS2/ZnO heterostructure nanorods exhibited ~97% removal of MB in the reaction time of 20 min with the catalyst amount of 0.15 g/L. The kinetic study revealed that the photocatalytic removal of MB was found to be in accordance with pseudo first-order reaction kinetics with an obtained rate constant of 0.16262 min-1. The tremendous photocatalytic performance of MoS2-ZnO heterostructure nanorods could be accredited to an effective charge transportation and inhibition in the recombination of photo-excited charge carriers at an interfacial heterojunction. The contribution of active species towards the decomposition of MB using MoS2-ZnO heterostructure nanorods was confirmed from scavenger study and terephthalic acid fluorescence technique.

Job satisfaction among physiotherapists in Saudi Arabia: does the leadership style matter?

BACKGROUND: Research has shown high rates of stress and dissatisfaction among allied health professionals, including physiotherapists, having an adverse impact on workforce retention rates. This study aimed to examine the job satisfaction and influential factors among physiotherapists working in private and government hospitals of Saudi Arabia with a focus on leadership style. METHODS: This was a cross-sectional observational study conducted among sixty-nine licensed physical therapists working in various health care settings in Riyadh. The Job Satisfaction Survey questionnaire was used to measure job satisfaction, and the Multifactor Leadership Questionnaire was used to measure perceptions of leadership style. Other data including demographic and work-related information were collected. Chi-square and Pearson's correlation analysis were used to establish correlation among the variables. RESULTS: The respondents from government and private hospitals showed non-significant differences (p > 0.05) among them on job satisfaction score, which was considered "ambivalent". Some of the respondents "slightly disagreed" in terms of pay, promotion, fringe benefits, contingent reward, operating conditions, and communication; however, rest of them "slightly agreed" for immediate supervision, co-workers, and the nature of work. Job satisfaction correlated significantly with female gender (p < 0.05) and musculoskeletal subspecialty of physiotherapy (p < 0.05) however, correlated non-significantly with leadership style (p > 0.05). CONCLUSIONS: All the physiotherapists, whether working in government or private hospitals, were neither fully satisfied nor fully dissatisfied with their jobs. Female physiotherapists from musculoskeletal subspecialty of physiotherapy were more satisfied than male physiotherapists from other subspecialty of physiotherapy. Of course, leadership style does matter in the job satisfaction among physiotherapists in the kingdom of Saudi Arabia.

Porous Polyethylene Coated with Functionalized Hydroxyapatite Particles as a Bone Reconstruction Material.

In this study, porous polyethylene scaffolds were examined as bone substitutes in vitro and in vivo in critical-sized calvarial bone defects in transgenic Sprague-Dawley rats. A microscopic examination revealed that the pores appeared to be interconnected across the material, making them suitable for cell growth. The creep recovery behavior of porous polyethylene at different loads indicated that the creep strain had two main portions. In both portions, strain increased with increased applied load and temperature. In terms of the thermographic behavior of the material, remarkable changes in melting temperature and heat fusion were revealed with increased the heating rates. The tensile strength results showed that the material was sensitive to the strain rate and that there was adequate mechanical strength to support cell growth. The in vitro cell culture results showed that human bone marrow mesenchymal stem cells attached to the porous polyethylene scaffold. Calcium sulfate-hydroxyapatite (CS-HA) coating of the scaffold not only improved attachment but also increased the proliferation of human bone marrow mesenchymal stem cells. In vivo, histological analysis showed that the study groups had active bone remodeling at the border of the defect. Bone regeneration at the border was also evident, which confirmed that the polyethylene acted as an osteoconductive bone graft. Furthermore, bone formation inside the pores of the coated polyethylene was also noted, which would enhance the process of osteointegration.

Isolation and characterization of microcrystalline cellulose from roselle fibers.

In this study, microcrystalline cellulose (MCC) was extracted from roselle fiber through acid hydrolysis treatment and its properties were compared with those of commercially available MCC. The physicochemical and morphological characteristics, elemental composition, size distribution, crystallinity and thermal properties of the obtained MCC were analyzed in this work. Fourier transform infrared spectroscopy (FTIR) analysis provided clear evidence that the characteristic peak of lignin was absent in the spectrum of the MCC prepared from roselle fiber. Rough surface and slight aggregation of MCC were observed by scanning electron microscopy (SEM). Energy dispersive X-ray (EDX) analysis showed that pure MCC with small quantities of residues and impurities was obtained, with a similar elemental composition to that of commercial MCC. A mean diameter of approximately 44.28µm was measured for MCC by using a particle size analyzer (PSA). X-ray diffraction (XRD) showed the crystallinity increased from 63% in roselle pulp to 78% in roselle MCC, the latter having a slightly higher crystallinity than that of commercial MCC (74%). TGA and DSC results indicated that the roselle MCC had better thermal stability than the roselle pulp, whereas it had poorer thermal stability in comparison with commercial MCC. Thus, the isolated MCC from roselle fibers will be going to use as reinforcing element in green composites and may be a precursor for future roselle derived nanocellulose, and thus a promising subject in nanocomposite research.

Incidence and prevalence of systemic lupus erythematosus among the native Arab population in UAE.

Background and objectives There is a paucity of information about the epidemiology of systemic lupus erythematosus (SLE) amongst Arabs. The objective of this study was to determine the incidence and prevalence of SLE among the native Arab population of United Arab Emirates (UAE). Methods Patients with SLE were identified from three sources: medical records of two local tertiary hospitals (four years; 2009 to 2012), laboratory requests for serum double stranded deoxyribonucleic acid and serum anti-nuclear antibody and confirmed histopathologic diagnosis of SLE (skin and kidney biopsy specimens). All the patients identified with SLE met the criteria of the American College of Rheumatology. Incidence and prevalence were calculated using the state records of the UAE native population as the denominator. The age-adjusted incidence was calculated by direct standardization using the World Health Organization world standard population 2000-2025. Results Sixteen new cases (13 females and three males) fulfilled the American College of Rheumatology SLE criteria. The mean (±SD) age at time of diagnosis was 28.6 ± 12.4 years. The crude incidence ratio (per 100,000 population) was 3.5, 1.1, 2.1 and 2.1 in years 2009, 2010, 2011, 2012, respectively. The age-standardized incidence per 100,000 population for the four years was 8.6 (95% confidence interval 4.2-15.9). The age-standardized prevalence of SLE among the native population according to the 2012 population consensus was 103/100,000 population (95% confidence interval 84.5-124.4). Conclusion The age-adjusted incidence and prevalence among UAE Arabs is higher than has been reported among most other Caucasian populations. Furthermore, the prevalence of SLE in UAE seems much higher than other similar Arab countries in the Gulf region.

Gestational diabetes mellitus prevalence: Effect of the laboratory analytical variation.

AIMS: To highlight the effect of laboratory analytic variation, assessed by glucose (a) total analytic laboratory error (TAEL) present in one index laboratory and (b) total recommended allowable error (TAEa) universally applicable to all laboratories, on the prevalence of gestational diabetes mellitus (GDM). METHODS: 2337 pregnant women underwent a 75-g oral glucose tolerance test (OGTT) for universal GDM screening. Since the true value of every laboratory result fluctuates within a range, the glucose TAEL and TAEa were used to define a lower and an upper diagnostic threshold (95% confidence interval, CI) for the three glucose OGTT cut-offs of the criteria of the American Diabetes Association, ADA (2003); the Canadian Diabetes Association, CDA (2013) and the International Association of Diabetes and Pregnancy Study Groups, IADPSG (2010). RESULTS: For the ADA, CDA and IADPSG criteria, respectively, the GDM prevalence [95% CI, (glucose TAEL) (glucose TAEa)] was 13.3% [(8.0-21.8) (6.3-25.9)], 30% [(17.3-53.1) (14.3-61.3)] and 45.3% [(27.0-71.0) (22.3-79.2)]. Using the lower and higher assigned OGTT glucose thresholds for TAEL, respectively, among the different criteria, either 200 (8.6%)-601 (25.7%) additional or 122 (5.2%)-426 (18.3%) fewer women would be identified with GDM (p<0.0001). CONCLUSIONS: Independent of the diagnostic criteria, any reported GDM prevalence can potentially vary between one half to two times even for laboratories meeting recommended quality specifications. To avoid misclassifying women with GDM substantially, individual laboratories can significantly reduce this disparity by improving analytic performance. All physicians must ensure that their laboratory meets acceptable quality standards for optimal patient care.

Gestational diabetes: differences between the current international diagnostic criteria and implications of switching to IADPSG.

AIMS: To highlight the differences between eight international expert panel diagnostic criteria (either current or outdated but in use) for the diagnosis of gestational diabetes mellitus (GDM) and implications of switching to the International Association of Diabetes in Pregnancy Study Groups (IADPSG) criterion. METHODS: 2337 pregnant women underwent a 75-g oral glucose tolerance test as part of a universal screening protocol. The GDM prevalence and number of women classified differently were compared between the criteria of the American Diabetes Association (2003); Australasian Diabetes in Pregnancy Society (1998); the Canadian Diabetes Association, CDA (2003 & 2013); the European Association for the Study of Diabetes (1996); IADPSG (2010); the New Zealand Society for the Study of Diabetes (2004) and the World Health Organization (1999). RESULTS: The prevalence varied from 9.2% to 45.3% with the different criteria. The IADPSG compared a) best with CDA 2013 [356(15.2%) women classified differently, (kappa, k=68.3%)] and b) worst with CDA 2003 [843 (36.1%) women classified differently, (k=21.8%)]; p<0.001.Switching to IADPSG from the original criteria would increase the prevalence 1.5-4.9 times. CONCLUSIONS: In 2015, the various international guidelines for GDM continue to show major discrepancies in the prevalence and the women classified dissimilarly. A consensus on a single global guideline would be a giant leap forward.