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Showing papers by "King Saud University published in 2008"


Journal ArticleDOI
10 Jan 2008-BMJ
TL;DR: Routine long term implementation of some of the measures to interrupt or reduce the spread of respiratory viruses might be difficult, however, many simple and low cost interventions reduce the transmission of epidemic respiratory viruses.
Abstract: Objective To systematically review evidence for the effectiveness of physical interventions to interrupt or reduce the spread of respiratory viruses. Data extraction Search strategy of the Cochrane Library, Medline, OldMedline, Embase, and CINAHL, without language restriction, for any intervention to prevent transmissionofrespiratoryviruses(isolation,quarantine, social distancing, barriers, personal protection, and hygiene). Study designs were randomised trials, cohort studies, case-control studies, and controlled before and after studies. Data synthesis Of 2300 titles scanned 138 full papers were retrieved, including 49 papers of 51 studies. Study qualitywaspoorforthethreerandomisedcontrolledtrials and most of the cluster randomised controlled trials; the observational studies were of mixed quality. Heterogeneity precluded meta-analysis of most data except that from six case-control studies. The highest quality cluster randomised trials suggest that the spread of respiratory viruses into the community can be prevented by intervening with hygienic measures aimed at younger children. Meta-analysis of six case-control studies suggests that physical measures are highly effective in preventing the spread of SARS: handwashing more than 10 times daily (odds ratio 0.45, 95% confidence interval 0.36 to 0.57; number needed to treat =4, 95% confidence interval 3.65 to 5.52); wearing masks (0.32, 0.25 to 0.40; NNT=6, 4.54 to 8.03); wearing N95 masks (0.09, 0.03 to 0.30; NNT=3, 2.37 to 4.06); wearing gloves (0.43, 0.29 to 0.65; NNT=5, 4.15 to 15.41); wearing gowns (0.23, 0.14 to 0.37; NNT=5, 3.37 to 7.12); and handwashing, masks, gloves, and gowns combined (0.09, 0.02 to 0.35; NNT=3, 2.66 to 4.97). The incremental effect of adding virucidals or antiseptics to normal handwashing to decrease the spread of respiratory disease remains uncertain. The lack of proper evaluation of global measures such as screening at entry ports and social distancing prevent firm conclusions being drawn. Conclusion Routine long term implementation of some physical measures to interrupt or reduce the spread of

555 citations


Journal ArticleDOI
TL;DR: This article critically reviews the relevance of using different types of vesicles as a model for human skin in permeation enhancement studies, concentrating primarily on liposomes after briefly surveying older models.

531 citations


Journal ArticleDOI
TL;DR: Results indicate that the a2 subunit of the proton pump has an important role in Golgi function.
Abstract: We identified loss-of-function mutations in ATP6V0A2, encoding the a2 subunit of the V-type H+ ATPase, in several families with autosomal recessive cutis laxa type II or wrinkly skin syndrome. The mutations result in abnormal glycosylation of serum proteins (CDG-II) and cause an impairment of Golgi trafficking in fibroblasts from affected individuals. These results indicate that the a2 subunit of the proton pump has an important role in Golgi function.

350 citations


Journal ArticleDOI
TL;DR: The most frequent inheritance pattern among primary immunodeficiencies (PIDs) were long thought to be exclusively recessive traits as mentioned in this paper, with a few X-linked recessive (XR) diseases.
Abstract: Primary immunodeficiencies (PIDs) were long thought to be exclusively recessive traits — autosomal recessive (AR) in most cases, with a few X-linked recessive (XR) diseases. In recent years, autosomal dominant (AD), mitochondrial, polygenic, and even somatic PIDs have been described. However, AR remains the most frequent inheritance pattern among recently described PIDs. Some PIDs have been shown to be genetically heterogeneous. Mendelian susceptibility to mycobacterial diseases (MSMD) displays a high level of genetic heterogeneity. There are 6 MSMD-causing genes, including 1 X-linked gene (nuclear factor-κB–essential modulator [ NEMO ]) and 5 autosomal genes (IFN-γ receptor 1 [ IFNGR1 ], IFN-γ receptor 2 [ IFNGR2 ], signal transducer and activator of transcription 1 [ STAT1 ], IL-12 p40 subunit [ IL12P40 ], and IL-12 receptor β-subunit [ IL12RB1 ]). The X-linked trait is XR; STAT1 deficiency is AD; the IFNGR2, IL12P40 subunit, and IL12RB1 deficiencies are AR; and IFNGR1 deficiency may be AD or AR. Two of the AR traits ( IFNGR1 , IFNGR2 ) may be subdivided into complete and partial deficiencies, and 3 AR complete deficiencies ( IFNGR1 , IFNGR2 , IL12RB1 ) may be subdivided into disorders with and without cell surface expression. Finally, there are 2 types of AD STAT1 deficiency, depending on whether the mutation impairs phosphorylation or DNA binding. Thirteen genetic disorders conferring MSMD have been described, involving 1 XR, 3 AD (2 genes), and 9 AR traits (4 genes). However, no genetic etiology has yet been identified for about half of all patients with MSMD. We expect to identify new XR and AD causes of MSMD, but new AR etiologies of MSMD are also likely to be discovered. The investigation of children from areas in which consanguineous marriages are common will probably facilitate the description of many more AR traits.

231 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of cosurfactants on transdermal delivery of hydrocortisone (model drug) from eucalyptus oil microemulsion were investigated.

221 citations


Journal ArticleDOI
TL;DR: The data suggest a significant role of parental Consanguinity in CHD, however, a relationship between consanguinity and other genetic diseases could not be established.
Abstract: BACKGROUND AND OBJECTIVES: There is a high rate of consanguinity in Saudi Arabia; however, information on its relationship with genetic disorders is limited. The objective of this cross-sectional s...

201 citations


Journal ArticleDOI
15 Nov 2008-Spine
TL;DR: Prophylactic use of large doses of TA provides an effective, safe, and cheap method for reducing blood loss during and after spinal operations and will help in reducing not only transfusion related complications but also operative expenses.
Abstract: STUDY DESIGN This is a double blind randomized placebo controlled study, after obtaining approval of ethics committee in the hospital and informed written consent, 64 patients were randomized equally into 2 groups (tranexamic acid (TA) and placebo) OBJECTIVE To evaluate efficacy and safety of large doses of TA on blood loss during spinal operations SUMMARY OF BACKGROUND DATA Blood loss associated with spinal operations is a common potential cause of morbidity and often requires blood transfusion which subject patients to the known risks of blood transfusion including transmission of diseases TA is used routinely to reduce bleeding in cardiac, orthopaedic, and hepatic surgery, however, its use in neurosurgery is uncommon and only few studies reported the use of antifibrinolytic drugs in spine surgery METHODS Sixty-four consecutive patients undergoing spinal surgery with expected significant blood loss at King Khalid University Hospital between June 2005 and December 2006 were randomly assigned to 2 groups, TA and placebo Shortly after the induction of anesthesia, patients received either TA or placebo as a loading dose of 2 g (for adults) or 30 mg/kg (for children), followed immediately by continuous infusion of 100 mg/h (for adults) or 1 mg/kg/h (for children) during surgery and for 5 hours after the operation Outcome measures included total (ie, intraoperative and postoperative) blood loss, amount of blood transfusion, as well as postoperative hemoglobin, and hematocrite levels The data were analyzed by means of Statistical Package for the Social Science Version 120 The results were presented as mean +/- SD Independent Student t test was used to compare the 2 groups and differences were considered significant if the P-value was <005 RESULTS There were 39 males and 25 females, ranging in age from 4 to 86 years with a mean of 51 and median of 56 years Eighteen patients had multilevel anterior cervical discectomies with or without internal fixation, 22 patients had decompressive surgery (12 laminectomies and 10 intersegmental decompressions) for multiseg- ment spinal stenosis, 15 patients had laminectomy with posterior spinal fixation, and remaining 9 patients had laminectomy and excision of spinal tumor Statistical analysis showed no significant differences between the 2 study groups with regard to age, sex, weight, preoperative hemoglobin, and hematocrite levels, type of surgery, as well as operative time In contrast, patients who received TA had 49% reduction of blood loss (P < 0007) and required 80% less blood transfusion (P < 0008) than patients who received placebo The hospital stay was shorter in the TA group, but it did not achieve statistical significance There were no complications related to the use of large doses of TA in this study CONCLUSIONS Prophylactic use of large doses of TA provides an effective, safe, and cheap method for reducing blood loss during and after spinal operations Hence, TAmay help in reducing not only transfusion related complications but also operative expenses Considering the limited number of patients in this study, our results need, however, to be validated on a larger number of patients, probably in a multicenter study

195 citations


Journal ArticleDOI
TL;DR: In this paper, the authors proposed neighbourhood sustainability criteria that mirror those used in sustainability analysis for higher level cities and towns, including consideration of the economic, the social, the technical and the environmental.

192 citations


Journal ArticleDOI
TL;DR: It is shown that C20orf7 is peripherally associated with the matrix face of the mitochondrial inner membrane and that silencing its expression with RNAi decreases complex I activity, and that mutations in C 20orf7 cause mitochondrial disease.
Abstract: Complex I (NADH:ubiquinone oxidoreductase) is the first and largest multimeric complex of the mitochondrial respiratory chain. Human complex I comprises seven subunits encoded by mitochondrial DNA and 38 nuclear-encoded subunits that are assembled together in a process that is only partially understood. To date, mutations causing complex I deficiency have been described in all 14 core subunits, five supernumerary subunits, and four assembly factors. We describe complex I deficiency caused by mutation of the putative complex I assembly factor C20orf7. A candidate region for a lethal neonatal form of complex I deficiency was identified by homozygosity mapping of an Egyptian family with one affected child and two affected pregnancies predicted by enzyme-based prenatal diagnosis. The region was confirmed by microcell-mediated chromosome transfer, and 11 candidate genes encoding potential mitochondrial proteins were sequenced. A homozygous missense mutation in C20orf7 segregated with disease in the family. We show that C20orf7 is peripherally associated with the matrix face of the mitochondrial inner membrane and that silencing its expression with RNAi decreases complex I activity. C20orf7 patient fibroblasts showed an almost complete absence of complex I holoenzyme and were defective at an early stage of complex I assembly, but in a manner distinct from the assembly defects caused by mutations in the assembly factor NDUFAF1. Our results indicate that C20orf7 is crucial in the assembly of complex I and that mutations in C20orf7 cause mitochondrial disease.

171 citations


Journal ArticleDOI
TL;DR: This paper adopts a recursive algorithm to solve the MSSI problem and a very effective dynamic programming algorithm to measure the similarity between the attributed nodes and agrees with many recent findings in psychology about the human perception of multiobject images.
Abstract: In this paper, a geometry-based image retrieval system is developed for multiobject images. We model both shape and topology of image objects using a structured representation called curvature tree (CT). The hierarchy of the CT reflects the inclusion relationships between the image objects. To facilitate shape-based matching, triangle-area representation (TAR) of each object is stored at the corresponding node in the CT. The similarity between two multiobject images is measured based on the maximum similarity subtree isomorphism (MSSI) between their CTs. For this purpose, we adopt a recursive algorithm to solve the MSSI problem and a very effective dynamic programming algorithm to measure the similarity between the attributed nodes. Our matching scheme agrees with many recent findings in psychology about the human perception of multiobject images. Experiments on a database of 13,500 real and synthesized medical images and the MPEG-7 CE-1 database of 1,400 shape images have shown the effectiveness of the proposed method.

160 citations


Journal ArticleDOI
TL;DR: In this article, the authors measured the infrared absorption spectra for pure TeO 2 glasses and doped with 10-wt% of different rare-earth oxides, La 2 O 3, CeO 2, Pr 2 O 4, Sm 2 O 5, Nd 2 O 6, and Yb 2 O 7.

Journal ArticleDOI
TL;DR: This report is the first to show a pregnancy after preimplantation genetic screening using the aCGH technology, and will open the door for enrollment of more patients.
Abstract: Recurrent IVF failure, implantation failure and early embryo demise can be attributed to the high frequency of chromosomal aneuploidy observed in human embryos. Preimplantation genetic screening (PGS) using multiple displacement amplifications (MDA) and array comparative genomic hybridization (aCGH) was successfully performed on eight patients with a minimum of seven recurrent IVF failures with the aim of detecting aneuploidy and ameliorating pregnancy rate. A total of 41 embryos with eight or more cells were biopsied by taking two blastomeres from each embryo. The DNA from these blastomeres were amplified and analysed by aCGH technology. The aCGH results showed a complex panel of chromosomal abnormalities in 60% of the diagnosed embryos. Some abnormalities could not be detected by the seven-probe panel (13, 16, 18, 21, 22, X and Y) used in fluorescence in-situ hybridization. Six out of eight patients had embryos for transfer with five out of those six showing positive pregnancy tests. As far as is known, this report is the first to show a pregnancy after PGS using the aCGH technology. The pregnancy rate obtained here is encouraging and will open the door for enrolment of more patients.

Journal ArticleDOI
TL;DR: It is shown that, under appropriate conditions, the topology given by the nonbipartite Ramanujan graphs optimizes the convergence rate of this distributed algorithm.
Abstract: Let N decision-makers collaborate to reach a decision. We consider iterative distributed inference with local intersensor communication, which, under simplifying assumptions, is equivalent to distributed average consensus. We show that, under appropriate conditions, the topology given by the nonbipartite Ramanujan graphs optimizes the convergence rate of this distributed algorithm.

Journal ArticleDOI
01 Mar 2008-Brain
TL;DR: The large cohort of COLQ patients studied here enabled us to define additional clinical presentations associated with COLQ mutations that differ from the 'classical' phenotypes: several patients with disease onset at birth or in early infancy presented an unexpected, mild disease course without significant progression of weakness.
Abstract: Congenital myasthenic syndromes (CMS) are clinically and genetically heterogeneous inherited disorders characterized by impaired neuromuscular transmission. Mutations in the acetylcholinesterase (AChE) collagen-like tail subunit gene (COLQ) cause synaptic basal-lamina associated CMS with end-plate AChE deficiency. Here we present the clinical and molecular genetic findings of 22 COLQ-mutant CMS patients, carrying a total of 20 different COLQ mutations, 11 of them had not previously been reported. Typically, patients with esterase deficiency suffer from a severe, progressive weakness with onset at birth or in early infancy. In addition, patients with a late onset showing a mild course of disease are described. AChE inhibitor therapy, beneficial for other forms of CMS, is of no effect in cases of esterase deficiency. The large cohort of COLQ patients studied here enabled us to define additional clinical presentations associated with COLQ mutations that differ from the 'classical' phenotypes: several patients with disease onset at birth or in early infancy presented an unexpected, mild disease course without significant progression of weakness. Moreover, many patients had clinical features reminiscent of limb-girdle CMS with mutations in the recently discovered DOK7 gene, including sparing of eye movements and a predominantly proximal muscle weakness. There was no long-term objective benefit from esterase inhibitors treatment in COLQ patients. Surprisingly, a short-term beneficial effect was observed in four patients and a Tensilon test was positive in two. Treatment with ephedrine was efficient in all five cases where it was administered. The variability of phenotypes caused by COLQ mutations, the divergence from the previously published classical clinical features and an initial positive response to esterase inhibitors in some patients may obscure AChE deficiency as the molecular cause of the disease and delay the start of appropriate therapy. Moreover, overlap with other CMS subtypes and potentially absence of a repetitive compound muscle action potential should be considered in the diagnosis of COLQ-mutated patients.

Journal Article
TL;DR: An Arabic translation of the Dundee Ready Education Environment Measure (DREEM) inventory was used to assess the educational environment at the College of Medicine in King Saud University, Riyadh to find that scores for first year students were significantly higher than the others.
Abstract: We used an Arabic translation (revised in our college) of the Dundee Ready Education Environment Measure (DREEM) inventory to assess the educational environment at the College of Medicine in King Saud University, Riyadh. Over 500 questionnaires were distributed and 222 were analysed. Scores were: 45.0% overall; 40.7% for students' perception of learning, 48.2% for perception of teachers, 46.3% for academic self-perception, 44.4% for perception of atmosphere, and 46.1% for social self-perception. Scores for first year students were significantly higher than the others. Scores for pre-clinical students were also significantly higher than those of students in clinical years. Sex was not a statistically significant variable.

Journal ArticleDOI
TL;DR: Cies prevalence and severity are very high in the study population, and most children have posterior tooth caries, and early measures such as fissure sealants, topical fluoride applications, and dietary fluoride supplements are needed to prevent caries of deciduous molars in high caries populations.
Abstract: AIM To determine caries prevalence, severity, and pattern in preschool children of Riyadh, Saudi Arabia. METHODS AND MATERIALS A total of 789 randomly selected preschool children, 379 (48%) male and 410 (52%) female, with mean age of 4.7 (SD 0.5) years were examined for dental caries using World Health Organization (WHO) diagnostic criteria. RESULTS The overall caries prevalence among the sample was 74.8%. The mean decayed, missing, and filled (dmft) score was 6.1 (SD 3.9) with a decay component of 4.66, a missing component of 0.54, and a filled component of 0.92. There was no significant difference (p>.05) in caries prevalence and severity in relation to gender of the children. However, the caries prevalence and severity were significantly higher (p<.05) among children from government preschools as compared to those from private preschools. Among the posterior teeth, mandibular second molars (54.3%), and among anterior teeth, maxillary central incisors (27.9%) had the highest caries prevalence. Among the molars, caries prevalence was generally high in lower molars while among the anterior teeth, upper teeth generally had a higher caries prevalence. The majority of the children (50.3%) had both posterior and anterior tooth caries, 42.2% had posterior tooth caries only, while very few (7.5%) children had only anterior tooth caries. CONCLUSION Caries prevalence and severity are very high in the study population, and most children have posterior tooth caries. CLINICAL SIGNIFICANCE Early measures such as fissure sealants, topical fluoride applications (as early as safely possible), and dietary fluoride supplements (where indicated) are needed to prevent caries of deciduous molars in high caries populations.

Journal ArticleDOI
TL;DR: Findings validate the use of Black seed in gastropathies induced by necrotizing agents and suggest the anti-ulcer effect of NS is possibly prostaglandin-mediated and/or through its antioxidant and anti-secretory activities.
Abstract: Background/Aim: Previous studies on Black seed or Black Cumin Nigella sativa (NS) have reported a large number of pharmacological activities including its anti-ulcer potential. These studies employed either fixed oil, volatile oil components or different solvent extracts. In folkloric practices, NS seeds are taken as such, in the form of coarse dry powder or the powdered seeds are mixed with water. This study examines the effect of NS aqueous suspension on experimentally induced gastric ulcers and basal gastric secretion in rats to rationalize its use by herbal and Unani medicine practitioners. Materials and Methods: The study was conducted at the Medicinal, Aromatic and Poisonous Plants Research Center, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia. Acute gastric ulceration was produced by various noxious chemicals (80% ethanol, 0.2 M NaOH, 25% NaCl and indomethacin) in Wistar albino rats. Anti-secretory studies were undertaken in a separate group of rats. Gastric wall mucus contents and non-protein sulfhydryl concentration were estimated, and gastric tissue was examined histopathologically. Results: An aqueous suspension of Black seed significantly prevented gastric ulcer formation induced by necrotizing agents. It also significantly ameliorated the ulcer severity and basal gastric acid secretion in pylorus-ligated Shay rats. Moreover, the suspension significantly replenished the ethanol-induced depleted gastric wall mucus content levels and gastric mucosal non-protein sulfhydryl concentration. The anti-ulcer effect was further confirmed histopathologically. Conclusion: These findings validate the use of Black seed in gastropathies induced by necrotizing agents. The anti-ulcer effect of NS is possibly prostaglandin-mediated and/or through its antioxidant and anti-secretory activities.

Journal ArticleDOI
TL;DR: Views towards information disclosure were midway between those of the USA and Japan, and decisions regarding life prolonging therapy and assisted suicide were not influenced to a great extent by wishes of the patient or family, but more likely by religious beliefs.
Abstract: Objectives: to assess physicians’ and patients’ views in Saudi Arabia (KSA) towards involving the patient versus the family in the process of diagnosis disclosure and decision-making, and to compare them with views from the USA and Japan. Design: A self-completion questionnaire (used previously to study these issues in Japan and the USA) was translated to Arabic and validated. Participants: Physicians (n = 321) from different specialties and ranks and patients (n = 264) in a hospital or attending outpatient clinics from 6 different regions in KSA. Results: In the case of a patient with incurable cancer, 67% of doctors and 51% of patients indicated that they would inform the patient in preference to the family of the diagnosis (p = 0.001). Assuming the family already knew, 56% of doctors and 49% of patients would tell the patient even if family objected (p NS). However, in the case of HIV infection, 59% of physicians and 81% of patients would inform the family about HIV status without the patient’s consent (p = 0.001). With regards to withholding ventilatory support, about 50% of doctors and over 60% of patients supported the use of mechanical ventilation in a patient with advanced cancer, regardless of the wishes of the patient or the family. Finally, the majority of doctors and patients (>85%) were against assisted suicide. Conclusions: Although there was more recognition for a patient’s autonomy amongst physicians, most patients preferred a family centred model of care. Views towards information disclosure were midway between those of the USA and Japan. Distinctively, however, decisions regarding life prolonging therapy and assisted suicide were not influenced to a great extent by wishes of the patient or family, but more likely by religious beliefs.

Book ChapterDOI
09 Jul 2008
TL;DR: A barcode-based system to help the visually impaired and blind people identify objects in the environment using QR codes affixed to an object and scanned using a camera phone equipped with QR reader software is introduced.
Abstract: In this paper a barcode-based system to help the visually impaired and blind people identify objects in the environment is introduced. The system is based on the idea of utilizing QR codes (two-dimensional barcode) affixed to an object and scanned using a camera phone equipped with QR reader software. The reader decodes the barcode to a URL and directs the phone's browser to fetch an audio file from the Web that contains a verbal description of the object. Our proposed system is expected to be useful in real-time interaction with different environments and to further illustrate the potential of our work, two scenarios are presented.

Journal ArticleDOI
TL;DR: This study shows the excellent efficacy of the HBV vaccination program in Saudi Arabia 18 years after its launch, and based on this study and others, a booster dose for the adult population appears to be unnecessary.

Journal ArticleDOI
TL;DR: In this paper, the effects of fin conductivity ratio, Darcy number, and Rayleigh number on the average Nusselt number for fin made of porous material when attached to the inner cylinder of the annulus between two concentric cylinders.
Abstract: Purpose – The aim is to study the effects of fin conductivity ratio, Darcy number, and Rayleigh number on the average Nusselt number for fins made of porous material when attached to the inner cylinder of the annulus between two concentric cylinders. The paper also aims to compare the results with those obtained using solid fins over a range of Rayleigh numbers.Design/methodology/approach – The Darcy‐Brinkman equations were used to model the fluid flow inside the porous media and the Boussinesq approximation was used to model the buoyancy effect. The energy equation is also solved to find the temperature distribution in the domain of interest. The model equations are solved numerically using a finite volume code.Findings – Porous fins provided higher heat transfer rates than solid fins for similar configurations. This enhancement in heat transfer reached 75 per cent at Ra=5 × 104 and Da=2.5 × 10−2. It is also found that unlike solid fins the rate of heat transfer from the cylinder equipped with porous fin...

Journal ArticleDOI
TL;DR: The standard values for French-Canadian children provided by Demirjian vary slightly for application to Saudi children, and both boys and girls in age groups nine to 14 years showed advanced dental age compared to their chronological age which was found to be statistically significant.
Abstract: Aim The aim of this study was to assess the dental age in Saudi children aged 8.5 to 17 years using the Demirjian method. Methods and materials Four hundred ninety panoramic radiographs of boys and girls were reviewed retrospectively. All children were placed in the age group closest to their chronological age. The dental age was scored on all seven left mandibular teeth by one examiner. Results Both boys and girls in age groups nine to 14 years showed advanced dental age compared to their chronological age which was found to be statistically significant except in age groups nine and 13 years. Saudi boys were 0.3 years and Saudi girls 0.4 years ahead, on average, of French-Canadian children as analyzed by the Demirjian method. Conclusion The standard values for French-Canadian children provided by Demirjian vary slightly for application to Saudi children. As a result, new graphs and tables were produced to convert these maturity scores, calculated by the Demirjian method, to the dental age for Saudi children.

Journal ArticleDOI
TL;DR: There is a high prevalence of Am use in the Riyadh region and the most important determinant of AM use was the perceived failure of medical treatment, which should alert decision makers to look at the difficult accessibility to the health system.
Abstract: centers using a specially designed questionnaire. RESULTS: Of 1408 individuals participating in the study, 39% were men. The mean (±SD) age for the study pop- - ulation was 35.5 (±13.9) years. Sixty-eight percent of the respondents had used AM during the last 12 months. The Holy Quran as a therapy was the most frequently used AM (50.3%), followed by honey (40.1%), black seed (39.2%) and myrrh (35.4%). The health belief model was found to be the most important determinant of AM use. Factors independently associated with AM use included perceived failure of medical treatment, the perceived success of AM, a preference for natural materials, and long appointment intervals to see physicians. CONCLUSIONS AND RECOMMENDATIONS: There is a high prevalence of AM use in the Riyadh region and the most important determinant of AM use was the perceived failure of medical treatment. The study results call for intensive health education campaigns in the media addressing wrong beliefs regarding AM and modern medicine. The popularity of AM in this community should alert decision makers to look at the difficult acces- - sibility to the health system.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the microstructure evolution in 1050 aluminum processed by equal channel angle pressing using Route BC and up to 16 passes, and found that the cell size gradually decreased with number of passes and attained an average value of about 0.6μm in the face plane (normal to the extrusion direction), and 0.85μm on the flow plane (parallel to the extrusion direction).
Abstract: Variation of mechanical properties and microstructure evolution in 1050 aluminum processed by equal channel angle pressing are investigated using Route BC and up to 16 passes. Micro hardness and compression testing were used to evaluate mechanical properties, whereas electron back scattered diffraction (EBSD) was used to document the variation of cell size and misorientation angle with number of passes. The hardness and yield strength exhibited an instant increase by a factor of about 2.75 and 2.96, respectively, compared to the annealed state, after only the first pass. It was found that the cell size gradually decreased with number of passes and attained an average value of about 0.6 μm in the face plane (normal to the extrusion direction), and 0.85 μm in the flow plane (parallel to the extrusion direction) after the sixteenth pass. The average misorientation angle evolved in both the face and flow planes ended up to about 27° and 26°, respectively.

Journal ArticleDOI
TL;DR: In this article, the suitability and performance of the AMF hybrid process for boron removal from seawater and/or RO first stage permeate was explored, and the results showed that the hybrid process performed well.

Journal ArticleDOI
TL;DR: In this paper, the effect of different variables, such as, concentration of Pb, mass of NB, pH, time, NB washing and heat treatment and temperature, was investigated.
Abstract: Lead (Pb) is one of the major environmental pollutants. Adsorption appears to be the most widely used for the removal of heavy metals. The aim of this work is to investigate the adsorption potential of commercial natural bentonite (NB) in the removal of Pb (II) ions from aqueous solution. The effect of different variables, such as, concentration of Pb, mass of NB, pH, time, NB washing and heat treatment and temperature was investigated. The bentonite sample under the heat and washed treatment are labeled as CB and WB respectively. The adsorption experiments were carried out using batch process. The equilibrium time for Pb (II) adsorption on NB was 5 min, the processes conforming to second order kinetics. NB had a much higher adsorption capacity for Pb (II) with the Langmuir monolayer capacity (qm) of 107, 110 and 120 mg g− 1 at 293, 313 and 333 K respectively compared to others adsorbents. Thermodynamic parameters such as ΔH°, ΔS° and ΔG° were calculated. The adsorption process was found to be endothermic and spontaneous. The enthalpy change for Pb (II) by NB adsorption has been estimated as 33 kJ mol−1, indicating that the adsorption of Pb (II) by NB corresponds to a physical reaction. The adsorption capacity of washed bentonite WB was very high compared to NB and CB Key word: Adsorption, clay minerals, bentonite, lead, wastewater treatment

Journal ArticleDOI
TL;DR: In this paper, the authors presented a thermal-comfort chart where indoor air temperatures are selected inside the summer and winter comfort-zones, as a function of relative humidity, in a manner to provide the highest comfort-level while maximizing energy savings.

Journal ArticleDOI
TL;DR: In this paper, the authors examined the possibility that a certain class of neutrino mass matrices, namely, those with two independent vanishing minors in the flavor basis, regardless of being invertible or not, is sufficient to describe current data.
Abstract: We examine the possibility that a certain class of neutrino mass matrices, namely, those with two independent vanishing minors in the flavor basis, regardless of being invertible or not, is sufficient to describe current data. We compute generic formulas for the ratios of the neutrino masses and for the Majorana phases. We find that seven textures with two vanishing minors can accommodate the experimental data. We present an estimate of the mass matrix for these patterns. All of the possible textures can be dynamically generated through the seesaw mechanism augmented with a discrete Abelian symmetry.

Journal ArticleDOI
TL;DR: In this article, two commercial nanofiltration (NF) membranes, viz., Desal-HL and NF 700 MWCO were investigated experimentally using neutral and charged solutes, viz, glucose, sodium chloride and magnesium chloride.

Journal ArticleDOI
TL;DR: Clinicians need to be aware of these differences when assessing women for the possibility of OSA as they may be symptomatic at a lower AHI and have significant comorbid conditions that can be adversely affected if their OSA was not timely managed.
Abstract: Obstructive sleep apnea (OSA) remains under-recognized in women possibly due to differences in clinical presentation, difference in tolerance to symptoms, and rate of usage and referral to sleep services. No reports have addressed OSA in women in the Middle Eastern (Arab) population. Therefore, we conducted this study to assess the differences in demographics, clinical presentation, and polysomnographic (PSG) findings between Saudi women and men diagnosed to have (OSA). The study group comprised 191 consecutive Saudi women and 193 consecutive men who were referred to the Sleep Disorders Centre and were found by in-laboratory PSG to have OSA. Demographic and clinical data were obtained by personal interviews. Women were significantly older than men (53.9 and 43.0 years, respectively; p < 0.001). Similarly, their body mass index was significantly higher than men (p < 0.001). Insomnia was more common among women (39.8%) compared to men (25.9%; p = 0.005). Other sleep symptoms including witnessed apnea, and excessive daytime sleepiness did not show any statistical difference between the two groups. Women were more likely than men to be diagnosed with hypothyroidism, diabetes, hypertension, cardiac disease, and asthma. Apnea-hypopnea index (AHI) was statistically higher in men compared to women; however, most of apnea/hypopnea events in women occurred during rapid eye movement sleep, and the mean duration of hypopnea and apnea was significantly lower in women (p = 0.004). Sleep efficiency was lower in women (71.5% vs. 77.7%) in men (p < 0.001). The desaturation index was higher in men (p = 0.01), but no difference was found in lowest SaO2 or time with SaO2 less than 90%. The present study showed important clinical and PSG differences between Saudi women and men with OSA. Clinicians need to be aware of these differences when assessing women for the possibility of OSA as they may be symptomatic at a lower AHI and have significant comorbid conditions that can be adversely affected if their OSA was not timely managed.