Facile one-pot synthesis of CuO nanospheres: Sensitive electrochemical determination of hydrazine in water effluents

Hydrazine (HZ) is massively used in several industrial applications. Adsorption of HZ through human skin creates carcinogenicity by disturbing the human organ system and thus, the quantification of HZ levels in environmental water samples is highly needed. The present work describes the short-term development of copper oxide nanospheres (CuO NS) by one-step wet chemical approach and their implementation on glassy carbon electrode (GCE) for the sensitive and selective quantification of the environmentally hazardous HZ. The CuO NS formation was identified by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and UV-visible spectroscopy. SEM images exhibited the uniform CuO NS with an average size of 85 nm. The linker-free CuO NS modified GCE offered high electrocatalytic activity against HZ determination by showing the linear range determination in the range of 0.5 to 500 µM, with the detection limit of 63 nM (S/N=3), and sensitivity of 894.28 µA mM-1 cm-2. Further, the developed HZ sensor displayed excellent repeatability and reproducibility and was successfully exploited for the determination of HZ in real environmental samples, implying that GCE/CuO-NS is a confident and low-cost electrochemical platform for HZ determination

A computational fluid dynamics study of combustion and emission performance in an annular combustor of a jet engine

This paper is a Computational Fluid Dynamics (CFD) study of the performance of a jet engine annular combustor that was subjected to various loading conditions. The aim is to comprehend the effect of various genuine working conditions on ignition and emission performance. The numerical models utilized for fuel ignition is the feasible k-ω model for turbulent stream, species transport (aviation fuel and air) with eddy-dissipation reaction modelling and pollution model for nitrogen oxides (NOX) emission. The results obtained confirm the findings described in the literature

Periodontal status among adult cigarette smokers using Miswak (Salvadora persica) for oral hygiene: A crosssectional study from Asir Region of Saudi Arabia

Purpose: To compare the periodontal status of exclusive users of Miswak (Salvadora persica) with that of exclusive toothbrush users among adult smokers of cigarettes in Saudi Arabia.Methods: This educational-institutional study included one hundred and fifty adult patients (age and socioeconomic status matched, SES) between the ages of 18 and 75, and were listed as the group I, II, and III, with 50 participants each (participants with no oral hygiene, toothbrush users and miswak users respectively). Oral hygiene habits, the number of cigarettes smoked, and time since the habit began. Periodontal and radiographic parameters were reported.Results: All parameters related to periodontium (plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD), gingival recession (Rec), clinical attachment level (CAL) and bone loss (BL)) showed that the analysed groups exhibited differences (p < 0.001). Least amount of BL (anterior and posterior) was found in toothbrush users and Miswak users, while least amount of attachment loss (both anterior and posterior) was recorded among Miswak users (p > 0.05). Positive association was found for GI (r = 0.753) and recession (r = 0.436, p < 0.001) in terms of the number of cigarettes smoked in group I, and anterior PPD (r = 0.388, p < 0.001) in group III for the duration of smoking. A negative correlation was found for BOP in group III (r = - 0.339, p < 0.05) in terms of frequency of tooth cleaning and GI (r = - 0.381) (p < 0.001) in group II, in terms of time taken attain oral hygiene.Conclusion: This study indicates less severe periodontal damage among adult current cigarette smokers in miswak users than in toothbrush users. Thus, there some potentials for miswak use for promotion of oral hygiene. Keywords: Periodontal status, Adult cigarette smokers, Miswak, Oral hygien

Investigate of the influence for multiple resistance welding currents in austerities nickel-chromium alloys on welded joints mechanical characteristics

We have studied the shear strength, with regards to 302 “austenitic stainless steel spot welds”. It is undeniable that the current for a welding within resistance spot welding development (RSW) shows a very important character. Nevertheless, these effects of this item are popular so it has been considered widely all through literature works. Our aim in this work is to show the effect of heat treatment on different joints welded at multiple currents. The experimental results demonstrate about a tensile shear strength that could be increased together along with the increasing in refer to current. Annealing treatment increases escorted by tensile shear strength as a size of grain reforms, in addition the remaining stresses removed. Refinement of grain serves to be an operative practice for a strength improvement. With that, the tensile; shear strength could be increased through having the annealed temperature of treatment reached; 750 C°. Regardless, at 850 C°, the tensile shear strength decreases

Effect of Newtonian and non-Newtonian flow in subject specific carotid artery

Advances in the numerical simulation techniques has immensely helped in the demonstrating the importance of blood flow through elastic arteries and evaluating the disease progression and flow dynamics of cardiovascular diseases such as atherosclerosis. The present work deals with a case study of a patient diagnosed with partial narrowing of entire cervical segment of Internal Carotid Artery (ICA), while Common Carotid Artery (CCA) and External Carotid Artery (ECA) appears to be normal. Subject specific 3D carotid bifurcation CAD model is generated based on CT-angio scan data using MIMICS-14.0 and numerical analysis is performed using Computational Fluid Dynamics (CFD) in ANSYS-CFX-14.0. Pulsatile blood flow through the subject-specific artery is investigated to study the influence of rheology on the haemodynamics in the blood flow. The simulation results obtained through Carreau-Yasuda and Newtonian models are investigated. Flow behaviour observed during peak systole exhibits significant difference in the spatial parameters between both the Newtonian and nonNewtonians models. The comparison of local shear stress magnitude in CCA, ICA and ECA demonstrates that WSS is highly influenced by the shear thinning property of blood. This variation is also observed artery branches with reduced lumen diameter, lumen narrowing due to stenosis and in the bifurcation zone

Effect of postural changes on normal and stenosed common carotid artery using FSI

Gravity associated with postural changes has a strong bearing on haemodynamics of blood flow in arteries. Its effect on stenosed cases has not been widely investigated. In the present study, variation observed in blood flow during postural changes is investigated for different conditions like standing, sleeping and head-down position. A fluid structure interaction study is carried out for idealized normal and 75 % eccentric and concentric stenosed common carotid normal artery. The results clearly indicate the effects of altered gravity on flow conditions. It was found to be very significant during head-down position and demonstrated very high arterial blood pressure in stenosed common carotid when compared with normal carotid

Periodontal Treatment Practice and Referral Profile of General Dentists – A Cross-sectional Questionnaire Survey

BACKGROUND: Because of medical advancement, the mean age of the general population is increasing gradually. This increase in the mean age of patients has led to its implications on oral health. Hence, it is logical to assume an increase in the figure of referrals to specialists and the complexity of treatments provided. AIM: The aim of the survey was to assess the current status of periodontal treatment provided, awareness of referral profile, and criteria taken into consideration for the referral to the periodontist by general dentists. MATERIALS AND METHODS: This cross-sectional questionnaire study was conducted among 318 general dentists. The relevant work related to the status of periodontal procedures provided by dentists and their referral relationships were studied. The questionnaire consisting of six questions was designed. Descriptive statistics, including frequency distributions and measures of central tendency and Chi-square test, were used. RESULTS: The study showed that majority of the general dentists do non-surgical procedures by their own. However, around 85% of respondents did not provide surgical periodontal treatment by themselves. About 25% of the responding general dentists thought that they had inadequate education and experience in the field of periodontics which was a major reason for the referral to specialists. CONCLUSION: It was concluded that the general dentists are comfortable in carrying out the non-surgical procedures, but they had some reservations about the periodontal surgical procedures. Inadequate experience and facilities were the major reasons for the referral to periodontists. More of this type of study should be conducted to know the basic level of periodontal practices carried out among the general dentists and about the referral to the specialists

Influence of blood pressure and rheology on oscillatory shear index and wall shear stress in the carotid artery

Atherosclerosis is a localized complication dependent on both the rheology and the arterial response to blood pressure. Fluid–structure interaction (FSI) study can be effectively used to understand the local haemodynamics and study the development and progression of atherosclerosis. Although numerical investigations of atherosclerosis are well documented, research on the influence of blood pressure as a result of the response to physio–social factors like anxiety, mental stress, and exercise is scarce. In this work, a three-dimensional (3D) Fluid–Structure Interaction (FSI) study was carried out for normal and stenosed patient-specific carotid artery models. Haemodynamic parameters such as Wall Shear Stress (WSS) and Oscillatory Shear Index (OSI) are evaluated for normal and hypertension conditions. The Carreau–Yasuda blood viscosity model was used in the FSI simulations, and the results are compared with the Newtonian model. The results reveal that high blood pressure increases the peripheral resistance, thereby reducing the WSS. Higher OSI occurs in the region with high flow recirculation. Variation of WSS due to changes in blood pressure and blood viscosity is important in understanding the haemodynamics of carotid arteries. This study demonstrates the potential of FSI to understand the causes of atherosclerosis due to altered blood pressures

Influence of Adiposity-Related Genetic Markers in a Population of Saudi Arabians Where Other Variables Influencing Obesity May Be Reduced

Large scale studies in Europeans have clearly identified common polymorphism affecting BMI and obesity. We undertook a genotype study to examine the impact of variants, known to influence obesity, in a sample from the Saudi Arabian population, notable for its profound combination of low mean physical activity indices and high energy intake. Anthropometry measures and genotypes were obtained for 367 Saudis, taken from King Saud University and Biomarker Screening Project in Riyadh (Riyadh Cohort). We observed large effect sizes with obesity for rs10767664 (BDNF) (OR = 1.923, P=0.00072) and rs3751812 (FTO) (OR = 1.523, P=0.016) in our sample and, using weighted genetic risk scores, we found strong evidence of a cumulative effect using 11 SNPs taken predominantly from loci principally affecting appetite (OR = 2.57, P=0.00092). We used conditional analyses to discern which of our three highly correlated FTO SNPs were responsible for the observed signal, although we were unable to determine with confidence which best marked the causal site. Our analysis indicates that markers located in loci known to influence fat mass through increased appetite affect obesity in Saudi Arabians to an extent possibly greater than in Europeans. Larger scale studies will be necessary to obtain a precise comparison

The Association Between FokI Vitamin D Receptor Polymorphisms With Metabolic Syndrome Among Pregnant Arab Women

Metabolic syndrome (MetS) is a serious health condition that is becoming extremely threatening in Saudi Arabia. The link between vitamin D receptor (VDR) gene polymorphisms and maternal MetS has been observed in several ethnic groups, but is yet to be clarified in the Arabian population. This study aims to investigate the relationship between the FokI VDR genotype and the risk of MetS and its components in pregnant Saudi women. A cross-sectional study was conducted using 368 pregnant Saudi women on first trimester screened for MetS (44 with MetS and 324 without MetS). Measurements included anthropometrics, glycemic and lipid profile and 25(OH)D. TaqMan genotyping assay was used to determine Fokl VDR genotype of participants. Vitamin D deficiency (25(OH)D <50nmol/l) was seen in 85% of the participants. An estimated 12% of participants had MetS. In the MetS group, the FokI VDR genotyping frequencies for FF, Ff, and ff genotypes were 50%, 36.4% and 13.6%, respectively. In controls, the frequencies were 62.7%, 31.4% and 5.9%, respectively. No significant association between the individual MetS components and FokI VDR genotypes were observed. Nevertheless, carriers of the ff allele had a significant risk for full maternal MetS [Odds Ratio 4.2 (95% Confidence Interval 1.4-12.2; adjusted p=0.009). The study suggests that the ff FokI VDR genotype is a genetic marker of maternal MetS in pregnant Arabian women. Prospective studies that include neonatal outcomes may confirm present findings