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      • SCOPUSKCI등재

        Spatiotemporal variations and source apportionment of NOx, SO₂, and O₃ emissions around heavily industrial locality

        Meshari Al-Harbi,Abdulrahman Al-majed,Asma Abahussain 대한환경공학회 2020 Environmental Engineering Research Vol.25 No.2

        The main objective of this study is to estimate the levels of pollution to which the community is presently exposed and to model the regimes of local air quality. Diurnal, daily, and monthly variations of NO, NO₂, SO₂, and O₃ were thoroughly investigated in three areas; namely, residential, industrial, and terminal in Ras Al-Khafji. There is obvious diurnal variation in the concentration of these pollutants that clearly follows the diurnal variation of atmospheric temperature and main anthropogenic and industrial activities. Correlation analysis showed that meteorological conditions play a vital role in shaping the pattern and transportation of air pollutants and photochemical processes affecting O₃ formation and destruction. Bivariate polar plots, an effective graphical tool that utilizes air pollutant concentrations’ dependence on wind speed and wind direction, were used to identify prevailing emission sources. Non-buoyant ground-level sources like domestic heating and street transport emissions, various industrial stacks, and airport-related activities were considered dominant emission sources in observatory sites. This study offers valuable and detailed information on the status of air quality, which has considerable, quantifiable, and important public health benefits.

      • Leisure Time Physical Activity in Saudi Arabia: Prevalence, Pattern and Determining Factors

        Amin, Tarek Tawfik,Al Khoudair, Ali Salah,Al Harbi, Mohammad Abdulwahab,Al Ali, Ahmed Radi Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.1

        Background: Identification of reliable predictors of leisure time physical activity (LTPA) will enable healthcare providers to intervene and change the patterns of LTPA in the population to improve community health. Objectives: The objectives of this study were to determine prevalence and pattern of LTPA among adult Saudis aged 18-65 years, and to define the socio-demographic determinants that correlate with LTPA in Al-Hassa, Saudi Arabia. Subjects and Methods: A cross-sectional study of 2176 adult Saudis attending urban and rural primary health care centers were selected using a multistage proportionate sampling method. Participants were personally interviewed to gather information regarding socio-demographics, physical activity pattern using the Global Physical Activity Questionnaire (GPAQ). Physical activity (PA) in each domain was expressed in metabolic equivalents (METs). Results: The median total METs minutes/week for LTPA for both genders was 256, higher for men (636 METs minutes/week) compared to women (249METs minutes/week). Overall, only 19.8% of the total PA was derived from LTPA. Of the sampled population 50.0% reported doing no leisure activity. Using the cut off of 600 METs-minutes/day or 150 minutes of moderate intensity over 5 or more days/week, only 21.0% of the included sample were considered as being sufficiently active and 10.4% were in the high active category with beneficial health effects. Multivariate regression analysis showed that male, younger age (<35 years), absence of chronic disease conditions and moderate level of total PA were significant predictors for being active in the LTPA domain. Conclusion: The prevalence and intensity of LTPA among the included sample demonstrated low levels. Nearly 80% of the included sample population did not achieve the recommended LTPA level with beneficial health effects. Female gender, urban residence and associated chronic diseases correlated with a low LTPA.

      • KCI등재

        Design and Cost Analysis for a Fault-Tolerant Distributed Shared Memory System

        ( Al-harbi Fahad Jazi ),( Kangseok Kim ),( Jai-hoon Kim ) 한국인터넷정보학회 2016 인터넷정보학회논문지 Vol.17 No.4

        Algorithms implementing distributed shared memory (DSM) were developed for ensuring consistency. The performance of DSM algorithms is dependent on system and usage parameters. However, ensuring these algorithms to tolerate faults is a problem that needs to be researched. In this study, we proposed fault-tolerant scheme for DSM system and analyzed reliability and fault-tolerant overhead. Using our analysis, we can choose a proper algorithm for DSM on error prone environment.

      • Poster Session : PS 0415 ; Infectious Disease ; QuantiRERON-TB Gold In-Tube in the Prevalence of Latent Tuberculosis Infection among Healthy Saudi Population

        ( Jamal Al Wakeel ),( Ziyad Makoshi ),( Mohammed Al Ghonaim ),( Ali Al Harbi ),( Abdulkareem Al Suwaida ),( Farjah Algahtani ),( Mogbil Al Hedaithy ),( Sultan Almogairin ),( Sami Habiballa Abdullah ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

        Background: Mycobacterium tuberculosis infection is the result of large number of morbidity and mortality worldwide. Saudi Arabia has an incidence rate ranged between8.6 and 12.2/100,000. QuantiFERON-TB Gold in-tube is approved to detect latent tuberculosis infection and TB disease. We conduct this study to estimate the prevalence of latent Tuberculosis in healthy population in Saudi Arabia and detect the sensitivity, specifi city and positive and negative predictive values for QuantiFERON-TB Gold in-tube. Methods: A cross-sectional study of blood sampling for QuantiFERON-TB Gold intube testing took from healthy blood donor were recruited from blood bank at King Saud University (KSU) and volunteers from Riyadh region, with further contact and follow up for positive results for two years for activation of latent tuberculosis. The study supported by King Saud University and King Abdul-Aziz City for Science and Technology. Project number ARP-245-29. Results: The study consists of 563 participants, their mean age was 34.2±13.17 year, 292 (51.9 %) male and mean BMI was 27.5 ±5.53 kg/m2. 363 (65.6%) had a BCG scar, the contact to the TB patients represented by 33 (5.9%) and 7 (1.2%) had a previous TB infection. Positive result for QFT-GIT was found in 72 (12.8%) participants, 48 (69.6%) of them had a BCG scar, only 2 (2.8%) and 4 (5.6%) had history of previous TB and contact of TB patients, respectively. Our study showed sensitivity of 90.62% (75-98%) and specificity of 91.53% (89-94%) with a positive predictive value of 39.19% (28-51%) and negative predictive value of 99.39% (98-99.9%) Conclusions: In face of reduction of the limits of other technique, QFT-GIT is not a signifi cant in diagnosis of latent TB. However, it is signifi cant in ruling out the presence of disease.

      • KCI등재

        Fabrication of highly hydrophilic tubular type perlite membrane support

        Omar A. Al-Harbi,Cem ÖZGÜR,M. M Khan 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.4

        We fabricated and characterized a highly hydrophilic membrane support using only perlite as an ore without altering itschemical and physical properties. Tubular-type microfiltration supports were fabricated by an extrusion technique. Plasticperlite paste was obtained by adding organic additives and water. The extruded samples were carefully dried to prevent cracksduring the drying period of 6 days with a controlled drying temperature and humidity. Green bodies were sintered attemperatures of 1000 oC, 1025 oC, and 1050 oC for 1, 3, and 6 hours. Tubular membrane supports were characterized in termsof microstructure, porosity, pore size distribution and crystalline phases. Additionally, the hydrophilicity of the samples wasdetermined by a thin layer wicking (TLW) approach. The water contact angles of the samples sintered at 1025 oC for 3 hourswere determined to be 20 o, and the porosity and mean pore size of the sample were 23.54% and 13 µm, respectively. The cleanwater permeability of the sample was 10.677 L/h.m2bar. According to the results, the obtained sample functions well as a highlyhydrophilic membrane support, and it is also a good candidate for a filter used in macro- and microfiltration processes. Filtration tests indicated that the median particle size of the solids in waste water is 500 nm, with a turbidity of 100 NTU, andthe waste water can be cleaned by the newly fabricated perlite tubular ceramics up to a turbidity level of 0.35 NTU, whichis acceptable in various industries

      • Increased Hypermethylation of Glutathione S-Transferase P1, DNA-Binding Protein Inhibitor, Death Associated Protein Kinase and Paired Box Protein-5 Genes in Triple-Negative Breast Cancer Saudi Females

        Hafez, Mohamed M.,Al-Shabanah, Othman A.,Al-Rejaie, Salim S.,Al-Harbi, Naif O.,Hassan, Zeinab K.,Alsheikh, Abdulmalik,Theyab, Abdurrahman I. Al,Aldelemy, Meshan L.,Sayed-Ahmed, Mohamed M. Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.2

        Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer (BC) with higher metastatic rate and both local and systemic recurrence compared to non-TNBC. The generation of reactive oxygen species (ROS) secondary to oxidative stress is associated with DNA damage, chromosomal degradation and alterations of both hypermethylation and hypomethylation of DNA. This study concerns differential methylation of promoter regions in specific groups of genes in TNBC and non-TNBC Saudi females in an effort to understand whether epigenetic events might be involved in breast carcinogenesis, and whether they might be used as markers for Saudi BCs. Methylation of glutathione S-transferase P1 (GSTP1), T-cadherin (CDH13), Paired box protein 5 (PAX5), death associated protein kinase (DAPK), twist-related protein (TWIST), DNA-binding protein inhibitor (ID4), High In Normal-1 (HIN-1), cyclin-dependent kinase inhibitor 2A (p16), cyclin D2 and retinoic acid receptor-${\beta}$ ($RAR{\beta}1$) genes was analyzed by methylation specific polymerase chain reaction (MSP) in 200 archival formalin-fixed paraffin embedded BC tissues divided into 3 groups; benign breast tissues (20), TNBC (80) and non-TNBC (100). The relationships between methylation status, and clinical and pathological characteristics of patients and tumors were assessed. Higher frequencies of GSTP1, ID4, TWIST, DAPK, PAX5 and HIN-1 hypermethylation were found in TNBC than in non-TNBC. Hypermethylation of GSTP1, CDH13, ID4, DAPK, HIN-1 and PAX5 increased with tumor grade increasing. Other statistically significant correlations were identified with studied genes. Data from this study suggest that increased hypermethylation of GSTP1, ID4, TWIST, DAPK, PAX5 and HIN-1 genes in TNBC than in non-TNBC can act as useful biomarker for BCs in the Saudi population. The higher frequency of specific hypermethylated genes paralleling tumor grade, size and lymph node involvement suggests contributions to breast cancer initiation and progression.

      • KCI등재

        Negative thermal expansion in porous glass-ceramics based on Mg2Al2B2Si5O18 prepared from Saudi raw materials

        Samah S. Eldera,Reem Al-wafi,Omar A. Al-Harbi,Christian Rüssel,Esmat M. A. Hamzawy 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.11

        A porous glass-ceramic enjoyed very low and negative thermal expansion was prepared. A glass of the base molar composition, 2 MgO·2 Al 2 O 3 ·2 B 2 O 3 ·5 SiO 2 with the addition of 1.61 ma% TiO 2 , was melted from kaolin, magnesite, silica sand and boric acid. The composition is based on cordierite where 50 % Al 2 O 3 were replaced by an equimolar concentration of B 2 O 3 . The glass was crashed and powdered, subsequently plastified, uniaxially pressed and finally sintered at temperatures in the range from 1100 to 1300 °C. X-ray diffraction of sintered samples gave evidence of a cordierite like crystalline phase. Scanning electron microscopy and electron dispersive microanalysis of samples prepared at 1300 °C showed crystals with hexagonal shape doped by TiO 2 , B 2 O 3 and Fe 2 O 3 embedded in a glassy matrix. With increasing crystallization temperature, the porosity of the glass-ceramics increased from 8.99 % (at 1200 °C for 3 min) to 56.42 % (at 1300 °C for 3 min). This led to a decrease of the specimen density from 1.9880 to 1.1278 g/cm 3 whereas the skeletal density increased from 2.1303 g/cm 3 to 2.5878 g/cm 3 . The microhardnesses were in the 5.60 and 6.00 GPa range. The coefficient of thermal expansion was between -3.26 and -2.27x10 -6 K -1 from room temperature up to 300 o C and -0.45 and 1.89x10 -6 K -1 from room temperature up to 500 °C. For the first time, to the best of our knowledge, a porous cordierite glass-ceramic with negative thermal expansion is reported. The partial replacement of Al 2 O 3 by B 2 O 3 enables to apply lower melting temperature which is advantageous for the production process.

      • Teratoma Formation in Immunocompetent Mice After Syngeneic and Allogeneic Implantation of Germline Capable Mouse Embryonic Stem Cells

        Aldahmash, Abdullah,Atteya, Muhammad,Elsafadi, Mona,Al-Nbaheen, May,Al-Mubarak, Husain Adel,Vishnubalaji, Radhakrishnan,Al-Roalle, Ali,Al-Harbi, Suzan,Manikandan, Muthurangan,Matthaei, Klaus Ingo,Mahm Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10

        Background: Embryonic stem cells (ESCs) have the potential to form teratomas when implanted into immunodeficient mice, but data in immunocompetent mice are limited. We therefore investigated teratoma formation after implantation of three different mouse ESC (mESC) lines into immunocompetent mice. Materials and Methods: BALB/c mice were injected with three highly germline competent mESCs (129Sv, BALB/c and C57BL/6) subcutaneously or under the kidney capsule. After 4 weeks, mice were euthanized and examined histologically for teratoma development. The incidence, size and composition of teratomas were compared using Pearson Chi-square, t-test for dependent variables, one-way analysis of variance and the nonparametric Kruskal-Wallis analysis of variance and median test. Results: Teratomas developed from all three cell lines. The incidence of formation was significantly higher under the kidney capsule compared to subcutaneous site and occurred in both allogeneic and syngeneic mice. Overall, the size of teratoma was largest with the 129Sv cell line and under the kidney capsule. Diverse embryonic stem cell-derived tissues, belonging to the three embryonic germ layers, were encountered, reflecting the pluripotency of embryonic stem cells. Most commonly represented tissues were nervous tissue, keratinizing stratified squamous epithelium (ectoderm), smooth muscle, striated muscle, cartilage, bone (mesoderm), and glandular tissue in the form of gut- and respiratory-like epithelia (endoderm). Conclusions: ESCs can form teratomas in immunocompetent mice and, therefore, removal of undifferentiated ESC is a pre-requisite for a safe use of ESC in cell-based therapies. In addition the genetic relationship of the origin of the cell lines to the ability to transplant plays a major role.

      • SCISCIESCOPUS

        On the contributions of different micromechanisms for enhancement in the strength of TI-6Al-4V alloy upon B addition: A nanomechanical analysis

        Seok, M.Y.,Zhao, Y.,Lee, J.A.,Mohamed, R.M.,Al-Harbi, L.M.,Al-Ghamdi, M.S.,Singh, G.,Ramamurty, U.,Jang, J.i. Elsevier Sequoia 2016 Materials science & engineering Structural materia Vol.649 No.-

        <P>The addition of small amount of boron to Ti and it alloys refines the as-cast microstructure and enhances the mechanical properties. In this paper, we employ nanoindentation on each of the constituent phases in the microstructure and 'rule-of-mixture' type analysis to examine their relative contributions to the strength enhancement in a Ti-6Al-4V alloy modified with 0.3 wt% B. Our results indicate to two main contributors to the relatively higher flow strength of B-modified alloy vis-a-vis the base alloy: (a) strengthening of alpha phase due to the reduction in the effective slip length that occurs as a result of the microstructural refinement that occurs upon B addition, and (b) composite strengthening caused by the TiB whiskers present in the alloy. (C) 2015 Elsevier B.V. All rights reserved.</P>

      • <i>Commiphora molmol</i> Modulates Glutamate-Nitric Oxide-cGMP and Nrf2/ARE/HO-1 Pathways and Attenuates Oxidative Stress and Hematological Alterations in Hyperammonemic Rats

        Mahmoud, Ayman M.,Alqahtani, Sultan,Othman, Sarah I.,Germoush, Mousa O.,Hussein, Omnia E.,Al-Basher, Gadh,Khim, Jong Seong,Al-Qaraawi, Maha A.,Al-Harbi, Hanan M.,Fadel, Abdulmannan,Allam, Ahmed A. Hindawi 2017 Oxidative medicine and cellular longevity Vol.2017 No.-

        <P>Hyperammonemia is a serious complication of liver disease and may lead to encephalopathy and death. This study investigated the effects of <I>Commiphora molmol</I> resin on oxidative stress, inflammation, and hematological alterations in ammonium chloride- (NH<SUB>4</SUB>Cl-) induced hyperammonemic rats, with an emphasis on the glutamate-NO-cGMP and Nrf2/ARE/HO-1 signaling pathways. Rats received NH<SUB>4</SUB>Cl and <I>C. molmol</I> for 8 weeks. NH<SUB>4</SUB>Cl-induced rats showed significant increase in blood ammonia, liver function markers, and tumor necrosis factor-alpha (TNF-<I>α</I>). Concurrent supplementation of <I>C. molmol</I> significantly decreased circulating ammonia, liver function markers, and TNF-<I>α</I> in hyperammonemic rats. <I>C. molmol</I> suppressed lipid peroxidation and nitric oxide and enhanced the antioxidant defenses in the liver, kidney, and cerebrum of hyperammonemic rats. <I>C. molmol</I> significantly upregulated Nrf2 and HO-1 and decreased glutamine and nitric oxide synthase, soluble guanylate cyclase, and Na<SUP>+</SUP>/K<SUP>+</SUP>-ATPase expression in the cerebrum of NH<SUB>4</SUB>Cl-induced hyperammonemic rats. Hyperammonemia was also associated with hematological and coagulation system alterations. These alterations were reversed by <I>C. molmol</I>. Our findings demonstrated that <I>C. molmol</I> attenuates ammonia-induced liver injury, oxidative stress, inflammation, and hematological alterations. This study points to the modulatory effect of <I>C. molmol</I> on glutamate-NO-cGMP and Nrf2/ARE/HO-1 pathways in hyperammonemia. Therefore, <I>C. molmol</I> might be a promising protective agent against hyperammonemia.</P>

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