410 research outputs found
Void growth in high strength aluminium alloy single crystals : a CPFEM based study
The author thankfully acknowledges the financial support of EPSRC funding (EP/L021714/1).Peer reviewedPostprin
OPTIMIZATION AT SERVICE VEHICLE ROUTING AND A CASE STUDY OF ISPARTA, TURKEY
A typical application area of vehicle routing problem (VRP) is School Bus Routing Problem. In this problem, mainly, it is aimed to minimize total service time, length, number of vehicles operating etc. and maximize the capacity utility etc. under some constraints such as allowable time etc. The aim of this study is to construct a method that helps to organize the travel plans of students residing in an area and to apply this method at a pilot school determined under some requirements. The results of the study suggested that there are differences in the sense of the distance, time, and number of stops on the route of the service vehicles while it can be said that there is equality only in capacity utility
A cost effectiveness analysis of salt reduction policies to reduce coronary heart disease in four Eastern Mediterranean countries.
BACKGROUND: Coronary Heart Disease (CHD) is rising in middle income countries. Population based strategies to reduce specific CHD risk factors have an important role to play in reducing overall CHD mortality. Reducing dietary salt consumption is a potentially cost-effective way to reduce CHD events. This paper presents an economic evaluation of population based salt reduction policies in Tunisia, Syria, Palestine and Turkey. METHODS AND FINDINGS: Three policies to reduce dietary salt intake were evaluated: a health promotion campaign, labelling of food packaging and mandatory reformulation of salt content in processed food. These were evaluated separately and in combination. Estimates of the effectiveness of salt reduction on blood pressure were based on a literature review. The reduction in mortality was estimated using the IMPACT CHD model specific to that country. Cumulative population health effects were quantified as life years gained (LYG) over a 10 year time frame. The costs of each policy were estimated using evidence from comparable policies and expert opinion including public sector costs and costs to the food industry. Health care costs associated with CHDs were estimated using standardized unit costs. The total cost of implementing each policy was compared against the current baseline (no policy). All costs were calculated using 2010 PPP exchange rates. In all four countries most policies were cost saving compared with the baseline. The combination of all three policies (reducing salt consumption by 30%) resulted in estimated cost savings of 39,000,000 and 31674 LYG in Syria; 1,3000,000,000 and 378439 LYG in Turkey. CONCLUSION: Decreasing dietary salt intake will reduce coronary heart disease deaths in the four countries. A comprehensive strategy of health education and food industry actions to label and reduce salt content would save both money and lives
Effects of Loading Conditions on Deformation Process in Indentation
Static indentation experiments are typically performed to characterize the mechanical properties of a material of interest by a rigid indenter of known geometry to various depths. In contrast, dynamic indentation of materials has not been fully studied. Evaluating material performance under dynamic loading conditions is a challenge and we demonstrate that various modelling schemes may be appropriate for different flavours of dynamic indentation. In order to compare underlying thermo-mechanics and deformation processes in a static and dynamic indentation process, indentation of a rigid indenter into a workpiece to a fixed chosen penetration is extensively studied. A nonlinear strain rate and temperature-sensitive material model is used to characterize the macroscopic response of a titanium-based beta-alloy to indentation
AN ALGORITHM TO DETECT THE RETINAL REGION OF INTEREST
Retina is one of the important layers of the eyes, which includes sensitive cells to colour and light and nerve fibers. Retina can be
displayed by using some medical devices such as fundus camera, ophthalmoscope. Hence, some lesions like microaneurysm,
haemorrhage, exudate with many diseases of the eye can be detected by looking at the images taken by devices. In computer vision
and biomedical areas, studies to detect lesions of the eyes automatically have been done for a long time. In order to make automated
detections, the concept of ROI may be utilized. ROI which stands for region of interest generally serves the purpose of focusing on
particular targets. The main concentration of this paper is the algorithm to automatically detect retinal region of interest belonging to
different retinal images on a software application. The algorithm consists of three stages such as pre-processing stage, detecting ROI
on processed images and overlapping between input image and obtained ROI of the image
Deformation Processes of Advanced Alloy in Indentation and Turning
A comparison of a dynamic indentation method with a quasi-static one is used to study evolution of penetration and a generated force in the indentation process. Turning (a machining process) and dynamic indentation techniques are expected to have similar ranges of strain, strain rate and stress values in the process zone of a workpiece in a case of similar kinematics and boundary conditions. Here, we study the underlying mechanics of these two techniques. Based on advanced finite-element models, similarities and differences between the indentation and turning processes are elucidated.This study demonstrates that some critical cutting parameters can be predicted from indentation process; however, noticeable differences in the underlying deformations do exist
The combined effect of prostaglandin administration and ram introduction in multiparous and nulliparous sheep in anestrous period on prolificacy
In the study it was aimed to investigate and compare the combined effectiveness of ram introduction (ram effect) and prostaglandin F2 alpha (PGF2α)
administration in multiparous and nulliparous Kangal White Karaman ewes during the out of breeding season. The ewes were first divided into two main
groups: non-lactating multiparous (Group M, n=104) and nulliparous (Group N, n=101). The multiparous and nulliparous animals were further divided in to two
subgroups. Group MRP (n=50 multiparous) and NRP (n=51 nulliparous) were injected with a single dose of PGF2α on the first day of ram introduction. And the
Group MR (n= 54) and NR (n= 50) served as controls with ram introduction but no PGF2α injection. In all of the groups, adult, purebred and fertile rams stayed with
the ewes for 45 days. The blood samples were collected at 3-day intervals for 18 days after ram introduction from subsets of ewes (n=17 per group) to monitor
the serum progesterone concentration. The total lambing ratios in multiparous and nulliparous animals were 72.1% (75/104) and 44.6% (45/101), respectively
(P<0.001). Among the PGF2α and non-PGF2α subgroups of multiparous and nulliparous ewes, the lowest lambing rate was observed in Group NR (36.0%). In
multiparous ewes (Groups MR and MRP), the mean progesterone level varied significantly among the days (P<0.001). In contrast, in Group NRP, the progesterone
levels varied significantly over the tested time course (P0.05). We concluded that being multiparous
contributes to the success of PGF2α administration in combination with ram introduction in the anestrous period in ewes. Furthermore, PGF2α administration
together with ram introduction positively affects the lambing rate in nulliparous ewes
Explaining the decline in coronary heart disease mortality in Turkey between 1995 and 2008.
BACKGROUND: Coronary heart disease (CHD) mortality rates have been decreasing in Turkey since the early 1990s. Our study aimed to determine how much of the CHD mortality decrease in Turkey between 1995 and 2008 could be attributed to temporal trends in major risk factors and how much to advances in medical and surgical treatments.
METHODS: The validated IMPACT CHD mortality model was used to combine and analyse data on uptake and effectiveness of CHD treatments and risk factor trends in Turkey in adults aged 35-84 years between 1995 and 2008.Data sources were identified, searched and appraised on population, mortality and major CHD risk factors for adults those aged 35-84 years. Official statistics, electronic databases, national registers, surveys and published trials were screened from 1995 onwards.
RESULTS: Between 1995 and 2008, coronary heart disease mortality rates in Turkey decreased by 34% in men and 28% in women 35 years and over. This resulted in 35,720 fewer deaths in 2008.Approximately 47% of this mortality decrease was attributed to treatments in individuals (including approximately 16% to secondary prevention, 3% angina treatments, 9% to heart failure treatments, 5% to initial treatments of acute myocardial infarction, and 5% to hypertension treatments) and approximately 42% was attributable to population risk factor reductions (notably blood pressure 29%; smoking 27%; and cholesterol 1%). Adverse trends were seen for obesity and diabetes (potentially increasing mortality by approximately 11% and 14% respectively). The model explained almost 90% of the mortality fall.
CONCLUSION: Reduction in major cardiovascular risk factors explained approximately 42% and improvements in medical and surgical treatments explained some 47% of the CHD mortality fall. These findings emphasize the complimentary value of primary prevention and evidence-based medical treatments in controlling coronary heart disease
Microfluidic-assisted ZIF-silk-polydopamine nanoparticles as promising drug carriers for breast cancer therapy
Metal–organic frameworks (MOFs) are heralded as potential nanoplatforms for biomedical applications. Zeolitic imidazolate framework-8 (ZIF-8), as one of the most well known MOFs, has been widely applied as a drug delivery carrier for cancer therapy. However, the application of ZIF-8 nanoparticles as a therapeutic agent has been hindered by the challenge of how to control the release behaviour of anti-cancer zinc ions to cancer cells. In this paper, we designed microfluidic-assisted core-shell ZIF-8 nanoparticles modified with silk fibroin (SF) and polydopamine (PDA) for sustained release of zinc ions and curcumin (CUR) and tested these in vitro in various human breast cancer cells. We report that microfluidic rapid mixing is an efficient method to precisely control the proportion of ZIF-8, SF, PDA, and CUR in the nanoparticles by simply adjusting total flow rates (from 1 to 50 mL/min) and flow rate ratios. Owing to sufficient and rapid mixing during microfluidic-assisted nanoprecipitation, our designer CUR@ZIF-SF-PDA nanoparticles had a desired particle size of 170 nm with a narrow size distribution (PDI: 0.08), which is much smaller than nanoparticles produced using traditional magnetic stirrer mixing method (over 1000 nm). Moreover, a properly coated SF layer successfully enhanced the capability of ZIF-8 as a reservoir of zinc ions. Meanwhile, the self-etching reaction between ZIF-8 and PDA naturally induced a pH-responsive release of zinc ions and CUR to a therapeutic level in the MDA-MB-231, SK-BR-3, and MCF-7 breast cancer cell lines, resulting in a high cellular uptake efficiency, cytotoxicity, and cell cycle arrest. More importantly, the high biocompatibility of designed CUR@ZIF-SF-PDA nanoparticles remained low in cytotoxicity on AD-293 non-cancer cells. We demonstrate the potential of prepared CUR@ZIF-SF-PDA nanoparticles as promising carriers for the controlled release of CUR and zinc ions in breast cancer therapy
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