Double-Diffusive Natural Convection with Cross-Diffusion Effects in an Anisotropic Porous Enclosure Using ISPH Method

A study on heat and mass transfer behaviour on an anisotropic porous medium embedded in square cavity/annulus is conducted using Incompressibe Smoothed Particle Hydrodynamics (ISPH) method. In the case of square cavity, the left wall has hot temperature Th and mass Ch and the right wall has cool temperature Tc and mass Cc and both of the top and bottom walls are adiabatic. While in the case of square annulus, the inner surface wall is considered to have a cool temperature Tc and mass Cc while the outer surface is exposed to a hot temperature Th and mass Ch. The governing partial differential equations are transformed to non-dimensional governing equations and are solved using ISPH method. The results present the influences of the Dufour and Soret effects on the heat and mass transfer. The effects of various physical parameters such as Darcy parameter, permeability ratio, inclination angle of permeability and Rayleigh numbers on the temperature and concentration profiles together with the local Nusselt and Sherwood numbers are presented graphically. The results from the current ISPH method are well validated and have favorable comparisons with previously published results and solutions by the finite volume method

Concise Synthesis of Macrocycles by Multicomponent Reactions

A short reaction pathway was devised to synthesize a library of artificial 18-27-membered macrocycles. The five-step reaction sequence involves ring opening of a cyclic anhydride with a diamine, esterification, coupling with an amino acid isocyanide, saponification, and, finally, macro-ring closure using an Ugi or, alternatively, a Passerini multicomponent reaction. Three out of the five steps allow for the versatile introduction of linker elements, side chains, and substituents with aromatic, heteroaromatic, and aliphatic character. The versatile pathway is described for 15 different target macrocycles on a mmol scale. Artificial macrocycles have recently become of great interest due to their potential to bind to difficult post-genomic targets

Rapidly Progressive IgA Nephropathy in One of a Pair of Identical Twins

Introduction: IgA nephropathy (IgAN) is the most common cause of primary glomerulonephritis worldwide. It was considered a benign condition for many years but long term follow up showed that it might progress to end stage renal disease (ESRD). The cause of primary IgAN is unknown and no consistent genetic abnormalities that predict the development or progression of IgAN have been identified. A variety of observations suggest an as-sociation to an unknown environmental antigen, familial clustering, or infectious agent. The patient presented here is the first report of a child with IgAN in Sudan. Case report: a seven years old boy was referred to our center for further evaluation and management of sudden onset macroscopic hematuria and renal impairment. He was born after an uneventful pregnancy and breast fed. He developed normally and was healthy before this illness. He had eight siblings who were all healthy, including his identical twin brother. Physical examination and laboratory tests led to the diagnosis of IgAN. The patient was treated with peritoneal dialysis and pulses of methylprednisolone for three consecutive days. He showed a remarkable response and regained normal renal function. He was then kept on alternate day’s steroids, ACE inhibitors, and Azathioprine. The other twin is being closely monitored. Conclusion: This report provides an indirect support for the hypothesis that environmental factors play a role in the pathogenesis of IgAN. However, follow up of the currently healthy twin is necessary, since affection with the disease may be expressed at a later time. Key words: IgA nephropathy, identical twins, macroscopic hematuri

The Association between Prolonged Occupational Exposure to Paraphenylenediamine (Hair-dye) and Renal Impairment

Introduction: Paraphenylenediamine (PPD) is widely used in hair dyes and cosmetic skin application. PPD intoxication following oral ingestion could be an important cause of ARF in Sudan, Morocco and the Indian Subcontinent. Repeated and prolonged exposure to PPD may also be associated with Chronic Kidney Disease (CKD). Methods: This is a cross-sectional study that covered six conveniently-chosen hairdressing saloons in Khartoum, Sudan. Hairdressers with regular professional exposure to PPD were evaluated for the presence of renal impairment (serum creatinine ≥ 2 mg/dl) and other markers of kidney damage. Results: The study included seventy-two females with a mean age of 40±8 years and a median duration of exposure to PPD of 6 years. Renal impairment, proteinuria and hematuria were observed in 14%, 26.4% and 41.1% of hair dressers, respectively. Hypertension, skin changes and bronchospasm were found in 19.4%, 38.9% and 22% of participants, respectively. Using pure forms of PPD significantly increased the risk of having elevated serum creatinine (OR 5.9; P = 0.02) and proteinuria (OR 9.8; P = 0.002) compared to manufactured forms with lower concentrations. Each additional year of exposure to PPD significantly increased the risk of having elevated serum creatinine (OR 1.3; P = 0.01), proteinuria (OR 1.4; P = 0.001) and hematuria (OR 1.1; P = 0.04). Conclusion: In this group of hairdressers with regular exposure to PPD, we observed high prevalence of renal impairment, proteinuria and hematuria. These findings were significantly associated with the use of pure forms of PPD and longer duration of exposure. Keywords: Chronic Kidney Disease; Hair Dye; Occupational Hazard; Paraphenylenediamine; Nephrotoxicit

Properties of High-Performance Concretes made of Black Sand at High Temperature

To modify high-performance concrete (HPC) fireproofing properties, black sand (BS) was partially substituted as fine aggregate at various levels. This study aims at evaluating the BS reliability in improving HPC durability properties for various construction applications based on its unique heavy minerals. To achieve this, five HPC series blends were setup to substitute fine aggregate independently with BS. Substitution percentages ranged from 15 to 100% with consistent supplementary cementing materials (SCMs) proportion for each gathering. Tests were performed to assess compressive strength before and after fire exposure under various temperatures of 250, 500 and 750 °C at different curing age. Generally, blending FA with BS was better than using SF with BS. Utilizing BS in the range of 15 to 60% as fine aggregate with 10% FA improves HPC fire-insulating properties. Besides, Z1 SEM analysis observed homogenously and compacted HPC microstructure at 250 and 500 °C. Doi: 10.28991/cej-2021-03091634 Full Text: PD

Antimicrobial Activity and Some Physiochemical Properties of Pumpkin (Cucurbita pepo L.) Seed oil

Pumpkin and squash plants grow in warm, humid regions,  cannot withstand frost. Most of the pumpkin consumed in Sudan was grown in Kordufan (western sudan).The use of plants and their extracts as remedies for curing many diseases have stimulate studies for investigating the presence of effective antimicrobial substances in them The present study was investigating the physiochemical and the biological activity of the different solvent extracts of pumpkin (Cucurbita pepo) seed oil (hexane, ethanol, methanol, and water) against two fungi  (A. niger and P. italicum) and two bacteria (E.coli and Staph. aureus).The inhibition zone method  was used for bacterial tests and the mycelia weight method was used for the fungal study. The results of the physiochemical showed that the specific gravity of the oil was between 0.997–0.908. The Refractive index was between 1.46–1.470. The average iodine value was 117.97,  the free fatty acids was between 0.2 and 0.55. The peroxide value was in the normal range (5.92–9 and the average saponification value was about 188. The biological study showed that the fresh and the dry weights of mycelia were highly reduced, although the reduction was only statistically different at the higher concentrations (75-100%).The fresh weights for the higher concentrations were 1.65 and 1.0 and for the lower concentrations were 3.1 and 3.7 for both A. niger and P. italicum, respectively. The inhibition zone of growth of both bacteria was far greater than that of the control treatment. The results indicated that the pumpkin oil extracts are more effective against bacteria compared to fungi. The hexane extract  was giving a large  inhibition zone (about 26.5 mm diameter) while, the ethanol extract was giving a less inhibition zone (about 14.2.mm diameter). On the other hand both methanol and the aqueous extracts were giving very low inhibition zones (13.5 and 13.6 mm diameter, respectively). However, more physiochemical characterizations need to be done  and the antifungal and the antibacterial properties  should verified in any further  studies on the pumpkin seed oil

Effect of Changing Properties of Wythes in Precast Structural Sandwich Panels

This study investigates the effects of changing in the properties of face and core wythes in structural sandwich panels (with dimensions of 500 500 mm and 120 mm total height). Concrete face wythes of three grades (80, 70, 37) MPa, thicknesses of (25, 35, and 45) mm, and three types of core materials (high density foam, polyethylene foam, and palm bark) were used in the production of panels. Steel shear connectors were installed in the panels with angle of 45º. Three-point bending load test was carried out on all panels and results were compared with both of the theoretical extremes capacities of non- composite and fully-composite states and ANSYS software results. The degree of composite action (%) and the (strength/weight) ratio were the main parameters that judged the specimens. It was found that upgrading concrete increased overall strength of slabs especially in high strength concrete (80 MPa), however the use of lightweight concrete (70 MPa) caused high (strength/weight) ratio due to very lightweight. Results revealed that decreasing thickness of concrete face wythes had a positive effect on strength/weight ratio (although the ultimate loads decreased) that enhanced the performance of panels as lightweight structural panels. The optimum face wythe thickness is that of 2.5 cm and has high (strength/weight) ratio. It was noticed that adding polyethylene foam as a core material results in positive effect and high (strength/weight) ratio. Results revealed that high strength concrete (80 MPa) and light-weight concrete (37 MPa) are very successful in the production face wythes of precast light-weight sandwich panels that can obtain high (strength/weight) ratio and high percent of composite action

Reporting Adverse Reactions of Skin Whitening Products in Wad- Medani Dermatology Hospital, Sudan

Background: There is growing concern about skin whitening both worldwide and in Sudan where there is no specific reporting system for the adverse reactions to whitening products. Objective: To identify adverse reactions associated with whitening products use through implementing an adverse reactions reporting system at the dermatology hospital in Wad -Medani, Sudan. Methods: A cross sectional study of patients presenting at the dermatology hospital in Wad-Medani, with adverse reactions (ARs) associated with the use of whitening products was done between October 2017 and September 2018.ARs reporting forms (containing socio-demographic characteristics, whitening products details and the detected ARs) were filled by the doctors attending both referral and out-patient clinics. Results: The study included 1000 patients aged 15- 48 years old, 98.5% of which were females. About 58% of patients had skin type VI, 32% skin type V and 10% skin type IV. More than 80% of the population used Hydroquinone and/or Clobetasol propionate or unlabeled mixtures of several whitening products bought from street vendors. Most patients (52%) used these products for more than 6 months. Acne, inflammation, ochronosis, hyperpigmentation, bacterial and fungal infections were the most reported ARs. The latter occurring in more than 42% of included patients. More than 68% of reported ARs were classified as severe by the treating doctors. Conclusion: Serious ARs of whitening products are prevalent and urgent measures are needed to address their irrational use. Vigilance ARs reporting systems are applicable and feasible which was evident since whitening products ARs reporting was continued even after the study was completed. The development and implementation of these systems should be adopted and encouraged by health authorities

Childhood Steroid Sensitive Nephrotic Syndrome: Characteristics and Predictors of Relapses; A study at a Single Center in Khartoum

Background: Childhood steroid-sensitive nephrotic syndrome (SSNS) usually has a favorable outcome in spite of its relapsing course. The objective of the authors was to study the demographic and clinical characteristics, outcome and risk factors for relapses in children with SSNS at a single center in Khartoum, Sudan. Material and Methods: In this cross-sectional, facility-based study, the authors retrospectively reviewed all the records of children with SSNS, followed at the Pediatric Renal Unit, Soba University Hospital, Khartoum between 2001 and 2014. SSRNS was defined as the remission of proteinuria within 4–6 weeks of corticosteroids. Relapse is therecurrence of proteinuria after remission; frequent if ≥ 2 within initial six months or ≥ 4 within one year, and steroid dependence if 2 during therapy or within 14 days after stopping it. Results: 330 children (males 220; 66.7%) with SSNS were studied with a mean age of 5.2 ± 3.5 years of whom 42.4% aged 1–5 years. At the presentation, hypertension was detected in 31.8% and hematuria in 19.1%. Serum cholesterol was elevated in all patients (mean 347.34 ± 117.87 mg/dl) and serum creatinine in 7.27% (mean 1.4 ± 0.35 mg/dl). Renal histology showed mesangioproliferative glomerulonephritis (MesPGN) in 57.5%, minimal change disease (MCD) in 35.5%, and focal segmental glomerulosclerosis (FSGS) and IgM nephropathy in 3.5% each. During the course of the illness, 10.3% achieved long-term remission, 89.7% relapsed— of whom 52.3% had frequent relapsing/steroid-dependent (FR/SD) course and 37.7% had infrequent relapses. Risk of frequent relapses were age of onset and low/moderate socioeconomic status (P = 0.015 and 0.019, respectively). Infectionswere recorded in 71.8%, but not significantly associated with the risk of frequent relapses (P > 0.05). Conclusions: The majority children with SSNS at this single center in Khartoum had a relapsing course with the majority being FR or SD. Predictors of frequent relapses were young age at onset and low socioeconomic status

‘Atypical Ugi’ tetrazoles

Amino acid-derived isocyano amides together with TMSN3, oxocomponents and 1° or 2° amines are common substrates in the Ugi tetrazole reaction. We surprisingly found that combining these substrates gives two different constitutional isomeric Ugi products A and B. A is the expected classical Ugi product whereas B is an isomeric product ('atypical Ugi') of the same molecular weight with the tetrazole heterocycle migrated to a different position. We synthesized, separated and characterized 22 different isomorphic examples of the two constitutional isomers of the Ugi reaction to unambiguously prove the formation of A and B. Mechanistic studies resulted in a proposed mechanism for the concomitant formation of A and B