165 research outputs found
The Effect of nano particles of TiO2-Al2O3 on the Mechanical properties of epoxy Hybrid nanocomposites
Preparation of epoxy/ TiO2 and epoxy/ Al2O3 nanocomposites is studed and investigated in this paper. The nano composites are processed by different nano fillers concentrations (0, 0.01, 0.02 ,0.03, 0.04 ,0.05 ,0.07 and 0.1 wt%). The particles sized of TiO2,Al2O3 are about 20–50 nm.Epoxy resin and nano composites containing different shape nano fillers of (TiO2:Al2O3 composites),are shear mixing with ratio 1 to 1,with different nano hybrid fillers concentrations( 0.025 ,0.0 5 ,0.15 ,0.2, and 0.25 wt%) to Preparation of epoxy/ TiO2- Al2O3 hybrid composites. The mechanical properties of nanocomposites such as bending ,wearing, and fatigue are investigated as mechanical properties
Prevalence, Comparison, and Determinants of Smoking among Young Schoolchildren in Kingdom of Saudi Arabia
BACKGROUND: Smoking is one of the most serious health issues among all age groups, particularly in children globally including the Gulf region. However, there are little data about the prevalence in public and private schools and determinants of smoking among adolescents in Saudi Arabia.
AIM: The purpose of this study was to estimate the prevalence, compare, and determine smoking habits among male children in public and private schools.
METHOD: This cross-sectional study was conducted in Dammam city, KSA. The data were collected from 866 male children studying in public and private schools. Sample was calculated through stratified random sampling. The modified “Global Youth Tobacco Survey (GYTS)” was used to collect information.
RESULTS: The total number of children recruited was 866 (223 from private and 643 from public schools). The mean age of children studied was 14.20 ± 1.03 years in both groups. The result shows that overall 27.8% of children tried to smoke cigarette both in public and private schools. The prevalence of smoking is higher in public schools’ children than in private schools (30% vs. 21%; p = 0.005). In addition, wrong perception of comfortable feeling after smoking, easy access to cigarettes, parent’s addiction, and smoking in front of children are the determining factors.
CONCLUSION: This study suggests that the prevalence of cigarettes smoking among children exists in considerable proportion. It is higher in public schools children. The health and education authorities should take urgent steps to encounter this major health issue
Two-stage PCR assay for detection of human brucellosis in endemic areas
BACKGROUND: Brucellosis is a common zoonosis that can cause a severe febrile illness in humans. It constitutes a persistent health problem in many developing countries around the world. It is one of the most frequently reported diseases in Saudi Arabia and incidence is particularly high in the Central region, and around the city of Riyadh. The aim of this study was to evaluate a two-stage PCR assay for detection of human brucellosis particularly in endemic areas. METHODS: A total of 101 serum samples were collected from patients with acute febrile illness (AFI) of unknown cause from two different locations in the Western region of Saudi Arabia. The first location (Northern) is characterized by a nomadic rural population while the second (Central) is a modern urban city. All samples were subjected to DNA extraction and Brucella genus-specific PCR amplification using B4/B5 primers of the bcsp31 gene. Positive B4/B5 samples were subjected to multiplex species-specific Brucella PCR amplification. RESULTS: In the Northern location, 81.9% of the AFI samples were confirmed Brucella positive, while all the samples collected from the Central region proved to be Brucella negative. Samples positive for Brucella were subjected to multiplex species-specific Brucella amplification. B. abortus was detected in 10% and B. melitensis in 8% of the samples, while the majority (82%) of samples showed both B. abortus and B. melitensis. As expected, B. suis was not detected in any of the samples. CONCLUSIONS: This study concluded that a two-stage PCR assay could be useful as a rapid diagnostic tool to allow the consideration of brucellosis as a possible cause of AFI, particularly in non-urban locations. It also recommends the collection of epidemiological data for such patients to obtain further information that may help in rapid diagnosis
Sensitivity, specificity of biochemical markers for early prediction of endothelial dysfunction in atherosclerotic obese subjects
Background: The obesity increased incidence of diabetes, hypertension and atherosclerosis and rate of morbidity and mortality. The main cause of atherosclerosis is endothelial dysfunction and formation of foam cells and macrophage that lead to unfavorable complications. This study evaluated specific biomarkers for endothelial dysfunction as sensitive indices for early predication of atherosclerosis in obese subjects.
Study Design: One hundred fifty male age and sex matching were included in the current study divided into three groups according to body mass index (BMI): Control (BMI ≤ 22), obese (BMI> 28) and obese with atherosclerosis (BMI> 28). Fasting serum was subjected for determination of adhesion molecules, sICAM-1, sVCAM-1, E-selectin, oxo-LDL and 8-iso-PGF2α by ELISA technique.
Results: Data obtained showed that, a significant elevation of serum inflammatory markers CRP, IL-6 and TNF-α and adhesion molecules sICAM-1 (p<0.001) with sensitivity 96%, sVCAM-1 (p <0.01) with sensitivity 92%, E-selectin (p<0.001) with sensitivity 94%, oxo-LDL (p <0.05) and 8-iso-PGF2α (p < 0.001) with sensitivity 97% in obese with atherosclerosis compared with obese and control.
Conclusion: The levels of serum adhesion molecules contributed in the pathogenesis of endothelial dysfunction can be used as sensitive biomarkers for early prediction of atherosclerosis in obese subjects.
Keywords: Obesity; atherosclerosis; endothelial dysfunction
RSM Analysis for Optimum Content of Graphene Nanoplatelets for 3D-Printed Clay Strength
This study applies Response Surface Methodologies (RSM) methods to maximize 3D-Printed clay mechanical properties. Mixes containing different Graphene Nanoplatelets (GNPs) contents were printed and tested in compression and flexure. The Central Composite Design method was used by coding the mixes fabrication method, i.e. moulding and printing, and GNPs content as variables. The analysis showed that the mixes containing low GNPs content of 0.1 wt.% attained higher compressive and flexural strengths than those containing a higher content of 0.2 and 0.3 wt.%. The results also highlighted that GNPs' efficiency was better observed in the printed samples other than the moulded ones, indicating that the printing process contributed to a better and uniform dispersion of GNPs in the clay matrix. RSM analysis confirmed that the maximum flexural strength response could be obtained using a GNPs content of 0.1 wt.%. Furthermore, the desirability analysis showed that a maximum predicted flexural and compressive strength improvements of 21% and 36 % compared to the control mixes could be obtained, respectively. In summary, this study proposed the importance of using Nanofilaments in 3D printing activities to achieve the desired elements' mechanical properties
Theileria lestoquardi in Sudan is highly diverse and genetically distinct from that in Oman
Malignant ovine theileriosis is a severe tick-borne protozoan disease of sheep and other small ruminants which is widespread in sub-Saharan Africa and the Middle East. The disease is of considerable economic importance in Sudan as the export of livestock provides a major contribution to the gross domestic product of this country. Molecular surveys have demonstrated a high prevalence of sub-clinical infections of Theileria lestoquardi, the causative agent, among small ruminants. No information is currently available on the extent of genetic diversity and genetic exchange among parasites in different areas of the country. The present study used a panel of T. lestoquardi specific micro- and mini-satellite genetic markers to assess diversity of parasites in Sudan (Africa) and compared it to that of the parasite population in Oman (Asia). A moderate level of genetic diversity was observed among parasites in Sudan, similar to that previously documented among parasites in Oman. However, a higher level of mixed-genotype infection was identified in Sudanese animals compared to Omani animals, consistent with a higher rate of tick transmission. In addition, the T. lestoquardi genotypes detected in these two countries form genetically distinct groups. The results of this work highlight the need for analysis of T. lestoquardi populations in other endemic areas in the region to inform on novel approaches for controlling malignant theileriosis
Performance of UMTS/WLAN Integration at Hot-Spot Locations Using OPNET
Due to the many benefits provided by both the third-generation (3G) mobile networks and the IEEE 802.11 wireless local area networks (WLANs), it is desirable to integrate both types of networks. While studies specifying generic integration architectures are abundant, there are little or no studies that are dedicated for applications performance over such heterogeneous networks. Using simulations, this paper evaluates the performance of two 3G/WLAN integration schemes: loose and open coupling, together with two mobility management schemes: Mobile IP and mobile stream control transmission protocol (mSCTP) for an airport as a typical example of a hot-spot location. In addition, the evaluation is carried out for a wide range of application mixes consisting of FTP, HTTP and multimedia. Utilizing OPNET as the simulation platform and incorporating the required protocols to support our implementation of the Mobile IP and mSCTP, we generate a large matrix of performance figures for the 4 network configurations under all applications mixes considered. The results summarized in this paper indicate that integration methods considered have little impact on the application mixes studied in terms of delay but show that FTP and HTTP throughput is better with loose coupling scheme. Further, quantifying the handoff delay between the 3G and WLAN networks, the results indicate that a loose-couple integration solution together with Mobile IP provides the best performance
Ultrasonographic and biochemical assessments as early prediction of polycystic ovarian syndrome in obese women
Backgroud: Polycystic ovary syndrome (PCOS) is considered as a common
cause of hormonal disturbance and obesity. The diagnosis of PCOS was
done by different methods including clinical signs as anovulation,
hyperandrogenism, biochemical markers and ultrasounographic
investigation. This study investigated comparative outcomes of
ultrasonographic and biochemical markers for early prediction of PCOS
in obese women. Subjects and methods: Seventy-five patients were
clinically diagnosed with obese, PCOS and obese with PCOS and
twenty-five normal age matched subjects were enrolled as control.
Abdominal and transvaginal ultrasonographic for assessment of ovarian
properties. In addition, BMI, serum free testosterone,
dehydroepiandrosterone (DHEA), insulin, glycosylated hemoglobin (HbA1c)
and LDL-c levels were evaluated. Results: In obese patients with PCOs
(20%) ovaries revealed normal appearance in morphology while the rest
(80%) showed PCOs in the form of cysts of 2\u20138 mm in diameter
peripherally arranged around stroma. A significant elevation of free
testosterone, DHEA and insulin in obese with or without PCOS compared
with obese group (p<0.001). A positive correlation with hormonal
abnormalities of increased HA1c, LDL-c, free testosterone, DHEA and
insulin compared with obese only. Conclusion: According to our study
findings, ovarian morphology combined with biochemical markers is more
reliable for early prediction and diagnosis of PCOS for interpretation
and management
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