CO2 Laser Photothermal Effects on Rats Skin Tissues

Spectroscopic and histological study of CO2 laser interaction with rats tissues were carried out. We detected for the first time the changes in optical absorption spectra of rat's tissues with selective CO2 laser optical densities ranging from 20.64 to 34.40W/cm2. The laser exposed tissues show higher absorbance in hemoglobin than that for the unexposed tissue. Using the same laser and same optical densities, the absorption spectra of fresh blood were measured. Much intense peaks of hemoglobin than that for the corresponding peaks for the tissue were detected. A scheme based on recent experimental findings is proposed for explanation of this novel phenomenon. The histological study shows thermal damage of blood vessels localized at the dermis layer. At high laser optical densities a vessel rupture with hemorrhage were occurred. The results indicate a pronounced modification of skin absorption properties by laser irradiation. Such an effect is due to thermally induced biophysical and biochemical processes inside the highly heterogeneous tissue structure. Keywords: CO2 laser, Photothermal effects, Hemoglobin absorption, Histolog

In vitro Anti-proliferative and Apoptotic Activities of Eurycoma longifolia Jack (Simaroubaceae) on HL-60 Cell Line

Purpose: To investigate the anti-proliferative, apoptotic and differentiating activities of Eurycoma longifolia root extracts on HL-60 leukemic cells.Methods: HL-60 cells were treated with different partially purified sub-fractions (F1 – F3) derived from the resin chromatography of the crude methanol root extract of E. longifolia roots, at different doses andtime points. The anti-proliferative activity of E. longifolia was assessed via cell counting and trypan blue exclusion. Apoptosis was evaluated via Annexin-V FITC/IP and Hoechst staining. Flow cytometry and Wright staining were used to assess its differentiation activities.Results: F1 showed unremarkable growth inhibition rate while F2 and F3 showed growth inhibitory effects with median inhibitory concentration (IC50) values of 15.2 and 28.6 ìg/ml, respectively. Treatment with F2 and F3 (100 ìg/ml) for 96 h increased cell death from 3.3 to 95.5 and 76.3 %,respectively. Treatment with F2 (50 ìg/ml) induced apoptosis by 14, 19.5 and 25 % after 24, 48 and 72 h, respectively. No differentiation activity was observed, as indicated by absence of myeloid maturation and a non-significant CD14 positivity (p > 0.05).Conclusion: E. longifolia extract (F2) showed promising anti-leukemic activity and can be a candidate for the development of a drug for the treatment of acute promyelocytic leukemia (APL).Keywords: Acute promyelocytic leukemia (APL), HL-60 cells, Eurycoma longifolia, Apoptosis, Antiproliferation, Differentiatio

The influence of technology readiness on information technology competencies and civil conflict environment

This study investigates the relationship between electricity consumption and real gross domestic product in Botswana (the world’s largest producer of diamonds). The study includes capital formation in a trivariate system for the period covering 1980-2008. Zivot and Andrews (1992) unit roots test; bound test for cointegration, and Granger causality test are employed.Unidirectional causality is found from electricity consumption to real gross domestic product is in line with study of Altinay and Karagol (2005) among others. The long run estimate reinforce the Granger causality tests by indicating that electricity consumption is positively associated with real gross domestic product in the long run. Further findings suggest unidirectional causality from capital formation to real gross domestic product. The implication is that Botswana- being a highly energy dependent country- will have the performance of its capital formation on the economy partly determined by adequate electricity

Design and Shape Optimization of Strain Gauge Load Cell for Axial Force Measurement for Test Benches

The load cell is an indispensable component of many engineering machinery and industrial automation for measuring and sensing force and torque. This paper describes the design and analysis of the strain gauge load cell, from the conceptional design stage to shape optimization (based on the finite element method (FEM) technique) and calibration, providing ample load capacity with low-cost material (aluminum 6061) and highly accurate force measurement. The amplifier circuit of the half Wheatstone bridge configuration with two strain gauges was implemented experimentally with an actual load cell prototype. The calibration test was conducted to evaluate the load cell characteristics and derive the governing equation for sensing the unknown load depending on the measured output voltage. The measured sensitivity of the load cell is approximately 15 mV/N and 446.8 µV/V at a maximum applied load of 30 kg. The findings are supported by FEM results and experiments with an acceptable percentage of errors, which revealed an overall error of 6% in the worst situation. Therefore, the proposed load cell meets the design considerations for axial force measurement for the laboratory test bench, which has a light weight of 20 g and a maximum axial force capacity of 300 N with good sensor characteristic

Underlying Primary Causes of Chronic Renal Failure: A Three-Year Study in Al-Thawra General Hospital, Sana'a, Yemen

Objective: To estimate the underlying primary diseases of chronic renal failure (CRF) among patients attending Al-Thawra General Hospital, Sana'a, and Yemen.Methods: This was a cross-sectional, hospital-based study of 566 patients diagnosed with chronic kidney diseases (CKD). It studied the cases attending Al-Thawra General Hospital over a three‐year period from January 2013 to December 2015.Results: Out of 566 patients, 339 (59.9%) were males. The mean age of the patients at diagnosis of CKD was 39.51 years, most of whom (36.6%) were of the age group of 21–35 years. Hypertension was the most frequent cause (43.2%) of CRF, followed by different infectious diseases such as malaria, schistosomiasis and bacterial infections (19%) and obstructive nephropathy (17.9%). On the other hand, CRF of unknown etiology represented 15.2% of cases. Other causes of CRF diabetic nephropathy (9.7%), effect of antibiotics and analgesics (7.0%), ischemic heart disease (4.8%, polycystic kidney disease (3.5%) and congenital anomalies (3.4%). The least common causes were autoimmune diseases, bleeding, traumatic accidents and chronic diarrhea, being responsible for 2.2%, 1.8%, 0.9% and 0.4% of CRF cases, respectively.Conclusions: The majority of CKD cases in our study were males aged between 21 and 35 years old. In addition, most cases of CKD are due to hypertension, followed by infections and obstructive nephropathy. Application of future prevention and control measures are highly recommended to reduce the burden of CRF in Yemen for early detection and proper management of its underlying primary conditions/diseases

Digital verification and authentication system for test certificates (DVASTC-COVID-19)

Coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus. The Covid-19 pandemic is a social and an economic crisis just as much as it is a health crisis – its repercussions, severe and far-reaching, are being felt across the world. The COVID-19 negative certificate or test results now becomes very important document for a lot of activities such as air travelling. A lot of cases had been published in the world about fake and change COVID-19 certificates/test results, especially in the airports. The certificates should be provided to permit travelling and immigration. Several approaches may be used to falsify the COVID-19 documents. For example, documents may be copied using copying machines, remade using word processing software or scanned, digitally modified and finally printed

Additive manufacturing of Ti-alloy: Thermal analysis and assessment of properties

In this study, 3D printing of Ti6Al4V alloy is realized and the characteristics of the printed layer are examined. The morphological structures and metallurgical changes in the printed layer are assessed. Temperature and stress fields are simulated in line with the experimental conditions. Since the air gaps are present in between the loose alloy powders prior to the printing, the effective properties incorporating the air fraction are determined and the effective properties are used in the simulations. Thermal conductivity of the loose alloy powders with the presence of air gaps is determined by incorporating the virtual experimental technique. It is found that the printed layer is free from micro-cracks and large scale asperities; however, some small pores sites are observed because of the release of air around the loose powders during the printing. Microhardness of the printed surface is higher in the top surface of the printed layer than that of as-received solid alloy. In addition, the friction coefficient of the printed surface remains lower than that of the conventionally produced solid surface. The columnar structures are formed in the mid-section of the printed layer and slanted grains are developed in the region of the top and the bottom surface of the printed layer.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The authors acknowledge the financial support of King Fahd University of Petroleum and Minerals (KFUPM) in Saudi Arabia, Gazi University and TAI (SAYP Project DDKIG1) in Turkey and King Abdullah City for Atomic and Renewable Energy (K.A.CARE) to accomplish this work

Laser Vaporization of Mouth Lesions, an Overview

Lasers are utilized in dentistry as a therapeutic tool or as an auxiliary tool. The major purpose of employing lasers in dentistry is to overcome the difficulties that are currently observed in traditional dental treatment treatments. The laser is used in hard tissue applications such as caries prevention, bleaching, restorative removal and curing, cavity preparation, dentinal hypersensitivity, growth modulation, and diagnostics, whereas soft tissue applications include wound healing, removal of hyperplastic tissue to uncover impacted or partially erupted teeth, photodynamic therapy for malignancies, and photo-stimulation of herpetic lesions. Lasers' capacity to perform minimally invasive operations with minimum patient discomfort has proven effective in the patient delivery system in dentistry practice. The availability of lasers with various wavelengths has produced a surgical panacea, and laser technology has replaced traditional surgical techniques in many oral surgical operations

Orthodontic treatment needs in the western region of Saudi Arabia: a research report

BACKGROUND: Evaluation of self perceived and actual need for orthodontic treatment helps in planning orthodontic services and estimating the required resources and man power. In the present study, the perceptive need as evaluated by patients and the actual need to orthodontic treatment, as assessed by orthodontists, were evaluated at two types of dental practices in the city of Jeddah using the Index of Orthodontic Treatment Need (IOTN). METHODS: A consecutive sample of 743 adults seeking orthodontic treatment at two different types of dental practices in Jeddah; King Abdulaziz University, Faculty of Dentistry (KAAU) (Free treatment) and two private dental polyclinics (PDP) (Paid treatment), was examined for orthodontic treatment need using the dental health component (DHC) of the IOTN. The self-perceived need for orthodontic treatment was also determined using the aesthetic component (AC) of the IOTN. The IOTN score and the incidence of each variable were calculated statistically. AC and DHC categories were compared using the Chi-Square and a correlation between them was assessed using Spearman's correlation test. AC and DHC were also compared between the two types of dental practices using the Chi-Square. RESULTS: The results revealed that among the 743 patients studied, 60.6% expressed no or slight need for treatment, 23.3% expressed moderate to borderline need and only16.1% thought they needed orthodontic treatment. Comparing these estimates to professional judgments, only 15.2% conformed to little or no need for treatment, 13.2% were assessed as in borderline need and 71.6% were assessed as in need for treatment (p < 0.001). Spearman's correlation test proved no correlation (r = -.045) between the two components. Comparing the AC and the DHC between the KAAU group and PDP group showed significant differences between the two groups (p < 0.001). CONCLUSION: Patient's perception to orthodontic treatment does not always correlate with professional assessment. The IOTN is a valid screening tool that should be used in orthodontic clinics for better services especially, in health centers that provide free treatment