184 research outputs found
Duplex surface treatment of steels by nitriding and chromizing
Duplex surface treatment, that is, chromizing and plasma nitriding (PN) of steels have attracted interest from industrial sectors because of its attractive properties and ability to apply on different types of steels. This paper aims to investigate duplex treatment on different types of steels at different treatment conditions. The improvements of the treated surfaces in terms of morphology and thickness, composition, surface hardness and roughness, as well as wear and friction of the engineered layer have been analysed. It was found that several layers of different thickness are formed due to duplex treatment which depends on the specimen’s carbon content and treatment temperature. Mainly carbides and nitrides of chromium and iron are formed, where the amount and composition of them are controlled by duplex treatment process parameters. These compounds enhance the hardness and wear resistance of the treated surface. The CrxN phase is the main contributor towards high microhardness of duplex-treated layers. In addition to high hardness, it also provides excellent wear resistance properties. The PN process reduces the coefficient of friction of chromized steels due to the lower friction coefficient of chromium nitride. However, the surface roughness of the treated surface increases due to the intrinsic properties of formed phases
Developments of rubber material wear in conveyer belt system
Regular degradation of rubbers contribute frequent maintenance of conveyer belt system. This paper investigates wear rate and mechanisms of rubber and associated influential parameters based on the information available in literature. Abrasion, fatigue and roll formation are dominate wear mechanisms that are influenced by load, sliding velocity, hardness and friction. Correlations among influential parameters and their effect on rubber wear was established in details. Archad's equation does not work for rubber wear but researchers have proposed equations similar to that. Adhesion wear forms roll in the smooth surface when tear strength of rubber is low. Wear caused by adhesion is abrasion when surface texture is harsh. Hysteresis enhances fatigue wear if the substrate asperities are round or blunt
Shariah and accounting principles for calculating the actual cost of lending services among Islamic banks: case of Malaysia
Shariah associations and bodies have permitted Islamic Banks to take the
actual cost of lending, that’s was due to the permissibility of differentiating between
the loan and the services accompanying its amortization, restriction and follow-up,
as these proceedings are not included in the principal of the loan. The Islamic banks
differed in applying the concept of actual cost based on a lump sum and a percentage.
The academies also differed in the methods of taking this cost, because the fee-based
services provided by Islamic banks may bring some legitimate issues related to
the imposition of fees or the actual cost. The research adopted the descriptive and
analytical approach and the quantitative method by studying the case of Malaysian
Islamic banks in accordance to the accounting principles and the related rules. The
research concluded that the total cost should be calculated by the application of the
following equation: Total cost (TC) = Penalty (P) + Compensation (C). In addition,
the total cost imposed for late payment must meet the following two conditions:
First, the total cost should not exceed the cost that the client bears in the traditional
bank, with the condition that the total cost of the penalty is not doubled on the late
installments or the due principal amount. Secondly, after calculating the total cost
imposed on the client for the late payment, the Islamic bank must submits a written
request to the Central Bank, explaining the justifications for imposing late payment
fees, the circumstances that led to the imposition of late payment fees, and attaching
working a plan after its approval by the Shariah Committee of the Islamic bank
Nutritional Habits and Weight Status among Jazan University Students: Eating Patterns and Healthy lifestyle Assessment
Objectives
The purposes of this study were to assess the prevalence of underweight, overweight, and obesity and to evaluate the nutritional habits, and related factors among the Students of Jazan University.
Methods
This cross-sectional study was carried out during the academic year 2014/2015 in Jazan University, Gizan, South West Saudi Arabia. A total of 436 students 19–25 y of age were examined. The questionnaires, including items on eating habits, lifestyle, and socio-demographic characteristics, were completed by the students. Data on weight, height were also collected. The data were analyzed using descriptive statistics and chi-square test. Differences were considered statistically significant at P. value < 0.05.
Results
The mean weight for males and females were 67.84 and 54.79 kg respectively, with significant differences between males and females (P. value <0.05). The mean BMI for all study participants was reported as 23.31 (kg/m²), also with significant difference between the males and females groups. About 45% of the students were of normal weight; the rate of obesity and underweight among students was very high (33.6% and 21.1% respectively), and their dietary habits were unhealthy. Regularity of meals was found only among (16.5% and 20.4%) males and females respectively. 83.3% of males and 95.1% of females reported eating snacks during the day.
Conclusion
The results of this study suggest that the prevalence of overweight and obesity were very high among the studied students. The study showed the need for health education programs on nutritional education in universities in order to increase awareness of students towards healthy eating and lifestyle.
 
Dietary intake of benzo(a)pyrene and risk of esophageal cancer in north of Iran
One etiologic factor for high incidence of esophageal squamous cell carcinoma (ESCC) in Golestan (Northeastern Iran) might be exposure to polycyclic aromatic hydrocarbons. We examined whether food and water are major sources of benzo(a)pyrene (BaP) exposure in this population. We used a dietary questionnaire to assess the daily intake of staple food (rice and bread) and water in 3 groups: 40 ESCC Golestan cases, 40 healthy subjects from the same area, and 40 healthy subjects from a low-risk area in Southern Iran. We measured, by high-performance liquid chromatography combined with fluorescence detection, the BaP concentration of bread, rice, and water in samples obtained from these 3 groups and calculated the daily intake of BaP. Mean BaP concentration of staple foods and water was similar and within standard levels in both areas, but the daily intake of BaP was higher in controls from the high-risk area than in controls from the low-risk area (91.4 vs. 70.6 ng/day, P < 0.01). In the multivariate regression analysis, having ESCC had no independent effect on BaP, whereas residence in the low-risk area was associated with a significant decrease in total BaP intake. Polycyclic aromatic hydrocarbons might, along with other risk factors, contribute to the high risk of ESCC in Golestan. Copyright © 2008, Taylor & Francis Group, LLC
The roles of HOXD10 in the development and progression of head and neck squamous cell carcinoma (HNSCC).
Background:
HOX gene expression is altered in many cancers; previous microarray revealed changes in HOX gene expression in head and neck squamous cell carcinoma (HNSCC), particularly HOXD10.
Methods:
HOXD10 expression was assessed by qPCR and immunoblotting in vitro and by immunohistochemistry (IHC) in tissues. Low-expressing cells were stably transfected with HOXD10 and the phenotype assessed with MTS, migration and adhesion assays and compared with the effects of siRNA knockdown in high-HOXD10-expressing cells. Novel HOXD10 targets were identified using expression microarrays, confirmed by reporter assay, and validated in tissues using IHC.
Results:
HOXD10 expression was low in NOKs, high in most primary tumour cells, and low in lymph node metastasis cells, a pattern confirmed using IHC in tissues. Overexpression of HOXD10 decreased cell invasion but increased proliferation, adhesion and migration, with knockdown causing reciprocal effects. There was no consistent effect on apoptosis. Microarray analysis identified several putative HOXD10-responsive genes, including angiomotin (AMOT-p80) and miR-146a. These were confirmed as HOXD10 targets by reporter assay. Manipulation of AMOT-p80 expression resulted in phenotypic changes similar to those on manipulation of HOXD10 expression.
Conclusions:
HOXD10 expression varies by stage of disease and produces differential effects: high expression giving cancer cells a proliferative and migratory advantage, and low expression may support invasion/metastasis, in part, by modulating AMOT-p80 levels
The association between different blood group systems and susceptibility to COVID-19: a single center cross-sectional study from Saudi Arabia
Background: Since the beginning of COVID-19 pandemic, many associated factors have been investigated to clarify the susceptibility and severity among the affected individuals. Biological markers can play an important role in identification of individual susceptibility to such pandemic. Growing evidence suggest the influence of different blood group systems on susceptibility to COVID-19 virus, with a particular blood type conferring selection advantage.
Objectives: The study aimed to determine the association of ABO, Rhesus (D) and P1 blood groups with COVID-19 susceptibility in Taif city, Western Saudi Arabia.
Methods: ABO, D and P1 blood antigens were determined in 104 blood samples of COVID-19 patients versus 100 control samples using either automated immunohematology analyser or test tube method. Statistical differences between patients and control samples were calculated based on p-value where results of ≤ 0.05 were considered significant.
Results: O+ve blood group constituted the predominant type among the studied samples. Determination of P1 antigen showed significant association where Anti-P1 was positive in 76.9% of patients compared to 61.0% of controls with a P value of 0.01 conferring the susceptibility of P1+ve patients to COVID-19.
Conclusion: Although our study showed no significant association between ABO and D, and susceptibility to COVID-19, there was a significant association between P1+ve and COVID-19. P1+ve participants were 2.131 times more associated with the risk of COVID-19 infection than those with Anti P1-ve. Thus, P1 antigen can be used as a biological marker for identification of individuals susceptibility to COVID-19. It is strongly advised that such individuals should consider extra protective measures.Further studies on other contributing factors should also be considered for more scientific clarity.
Keywords: ABO Blood group; Rh(D); P1 antigen, COVID-19
Blue biotechnology: Computational screening of sarcophyton cembranoid diterpenes for SARS-CoV-2 main protease inhibition
The coronavirus pandemic has affected more than 150 million people, while over 3.25 million people have died from the coronavirus disease 2019 (COVID-19). As there are no established therapies for COVID-19 treatment, drugs that inhibit viral replication are a promising target; specifically, the main protease (Mpro) that process CoV-encoded polyproteins serves as an Achilles heel for assembly of replication-transcription machinery as well as down-stream viral replication. In the search for potential antiviral drugs that target Mpro, a series of cembranoid diterpenes from the biologically active soft-coral genus Sarcophyton have been examined as SARS-CoV-2 Mpro inhibitors. Over 360 metabolites from the genus were screened using molecular docking calculations. Promising diterpenes were further characterized by molecular dynamics (MD) simulations based on molecular mechanics-generalized Born surface area (MM-GBSA) binding energy calculations. According to in silico calculations, five cembranoid diterpenes manifested adequate binding affinities as Mpro inhibitors with ΔGbinding \u3c -33.0 kcal/mol. Binding energy and structural analyses of the most potent Sarcophyton inhibitor, bislatumlide A (340), was compared to darunavir, an HIV protease inhibitor that has been recently subjected to clinical-trial as an anti-COVID-19 drug. In silico analysis indicates that 340 has a higher binding affinity against Mpro than darunavir with ΔGbinding values of -43.8 and -34.8 kcal/mol, respectively throughout 100 ns MD simulations. Drug-likeness calculations revealed robust bioavailability and protein-protein interactions were identified for 340; biochemical signaling genes included ACE, MAPK14 and ESR1 as identified based on a STRING database. Pathway enrichment analysis combined with reactome mining revealed that 340 has the capability to re-modulate the p38 MAPK pathway hijacked by SARS-CoV-2 and antagonize injurious effects. These findings justify further in vivo and in vitro testing of 340 as an antiviral agent against SARS-CoV-2
Extremely High Tp53 Mutation Load in Esophageal Squamous Cell Carcinoma in Golestan Province, Iran
Background: Golestan Province in northeastern Iran has one of the highest incidences of esophageal squamous cell carcinoma (ESCC) in the world with rates over 50 per 100,000 person-years in both sexes. We have analyzed TP53 mutation patterns in tumors from this high-risk geographic area in search of clues to the mutagenic processes involved in causing ESCC. Methodology/Principal Findings: Biopsies of 119 confirmed ESCC tumor tissue from subjects enrolled in a case-control study conducted in Golestan Province were analyzed by direct sequencing of TP53 exons 2 through 11. Immunohistochemical staining for p53 was carried out using two monoclonal antibodies, DO7 and 1801. A total of 120 TP53 mutations were detected in 107/119 cases (89.9), including 11 patients with double or triple mutations. The mutation pattern was heterogeneous with infrequent mutations at common TP53 "hotspots" but frequent transversions potentially attributable to environmental carcinogens forming bulky DNA adducts, including 40 at bases known as site of mutagenesis by polycyclic aromatic hydrocarbons (PAHs). Mutations showed different patterns according to the reported temperature of tea consumption, but no variation was observed in relation to ethnicity, tobacco or opium use, and alcoholic beverage consumption or urban versus rural residence. Conclusion/Significance: ESCC tumors in people from Golestan Province show the highest rate of TP53 mutations ever reported in any cancer anywhere. The heterogeneous mutation pattern is highly suggestive of a causative role for multiple environmental carcinogens, including PAHs. The temperature and composition of tea may also influence mutagenesis
- …