Current status of Bifurcation stent systems

ACoronary bifurcation lesions are frequently observed and remain a challenging patient population for successful treatment. Currently, the provisional approach of treatment is considered the first-line method of treatment. Many dedicated bifurcation stents and newer treatment approaches such as drug-coated balloons and bioresorbable scaffolds are also particularly attractive concepts. The aim of this article is to review the current treatment approaches for coronary bifurcation lesions, mainly the dedicated bifurcation stent systems while briefly covering the related topics of provisional and two-stent procedures of treatment and the current status of drug-coated balloons and bioresorbable scaffolds. This article highlights the critical trials involving these strategies. We searched PubMed, Google Scholar, Medline and ClinicalTrials.gov to identify all the relevant trials assessing the safety and efficacy of dedicated bifurcation stent systems, drug-coated balloons vs. other traditionally used coronary stents. A debate still prevails to treat coronary bifurcation lesions optimally. Provisional stenting strategy remains the gold standard for treating a majority of coronary bifurcation lesions, but the two-stent approach can be indicated for some lesions. More long-term follow-up trials are required to concretely define the role of newer treatment approaches such as dedicated bifurcation stents, drug-coated balloons, and bioresorbable scaffolds

THE RELATIONSHIP BETWEEN MEAN PLATELET VOLUME AND CORONARY COLLATERAL VESSELS IN PATIENTS WITH ACUTE CORONARY SYNDROMES

Background: Elevated mean platelet volume (MPV) has been proposed as a risk factor for coronary artery disease (CAD) and is associated with poor clinical outcomes in acute coronary syndrome (ACS). However, some studies have contradictory findings. Hence we aimed to evaluate the association of MPV with the presence of coronary collateral vessels (CCV) in patients with ACS. Objective: To find MPV value in ACS patients and to find the predictive value of MPV in the spectrum of CAD and to examine whether levels of MPV predict the presence of CCVs. Methods: A total of 180 patients with first ACS were included in the study. Mean platelet volume (MPV) was measured. All patients underwent coronary angiography to know disease severity and coronary collateral vessels (CCVs). The CCVs are graded according to the Rentrop scoring system and According to coronary angiography results, patients were divided into two groups as Group 1 (poor CCV) and Group 2 (good CCV). Results: The mean MPV was 10.74 ± 2 fl in poor collaterals group patients and 11.01 ±1.7 fl in good collaterals group (p-value 0.421). The presence of CCV was not significantly associated with high levels of MPV. MPV value did not show any prediction of the spectrum of coronary artery disease. Conclusion: MPV on admission was not associated with the development of CCV positively in patients with ACS. Also, it is not associated with the number of vessel involvements. KEYWORDS: Acute coronary syndrome, Coronary artery disease, Mean platelet volume, Coronary collateral vessels, Rentrop criteria

Observations and modeling of mixing processes in a fresh water reservoir - Valle de Bravo (Mexico)

Current understanding of small-scale physical processes, such as mixing, in tropical water bodies is lacking and observations are scarce at best. This study sheds more light on these processes through a combined observational-modeling approach. For this purpose, observations were made in Valle de Bravo's freshwater reservoir, about 100 km west of Mexico City and at an elevation of 1830 m above sea surface. Turbulence kinetic energy dissipation (TKED) rates were estimated by fitting a theoretical Batchelor spectrum to the temperature gradient spectrum. From similarity scaling of dissipation rates, it was found that in the surface layer, winds were the main driving force in generating turbulence during the day, while convective forces were responsible during the night. Bottom boundary layer (BBL) mixing was mainly driven by internal wave (first vertical and first horizontal mode) breaking at the bottom. Lognormality of turbulence dissipation rates is also discussed for surface, intermediate and bottom boundary layers. For our modeling efforts, a state-of-the-art one-dimensional turbulence model was used and forced with the observed surface meteorology to obtain simulated temperature and dissipation rate profiles. The model results were found to be in good agreement with the observations, though minor differences in dissipation rates were found in the vicinity of the thermocline and the BBL

Real Time Flow Control System for Precise Gas Feed in COIL

This paper reports development of a real time flow control system for precise, controlled and uniform gas feed to a flowing medium Chemical Oxygen Iodine Laser (COIL). The optimal operation of this prominent laser depends upon the desired supply of gas constituents such as nitrogen (N2), chlorine (Cl2) and iodine (I2) to achieve adequately mixed laser gas. The laser also demands real time variation of flow rates during gas constituent transitions in order to maintain stabilized pressures in critical subsystems. Diluent nitrogen utilized for singlet oxygen transport is termed as primary buffer gas and that for iodine transport is termed as secondary buffer gas (with main and bypass components). Also, nitrogen in precise flows is used for mirror blowing, nozzle curtain, cavity bleed and diffuser startup. A compact hybrid data acquisition system (Hybrid DAS) for precise flow control using LabVIEW 2014 platform has been developed. The supported flow ranges may vary from few mmole.s-1 to few hundred mmole.s-1. The estimated relative uncertainty in the largest gas component i.e. primary buffer gas feed is nearly 0.7%. The implementation of in-operation variation using flow ramp enables swift stabilization of singlet oxygen generator pressures critical for successful COIL operation. The performance of Hybrid DAS is at par with fully wired DAS providing the crucial benefit of remote field operation at distances of nearly 80m in line of sight and 35m with obstacle

Viability, Development, and Reliability Assessment of Coupled Coastal Forecasting Systems

Real-time wave forecasts are critical to a variety of coastal and offshore opera- tions. NOAA’s global wave forecasts, at present, do not extend into many coastal regions of interest. Even after more than two decades of the historical Exxon Valdez disaster, Cook Inlet (CI) and Prince William Sound (PWS) are regions that suffer from a lack of accurate wave forecast information. This dissertation develops high- resolution integrated wave forecasting schemes for these regions in order to meet the critical requirements associated with shipping, commercial and sport fishing vessel safety, and oil spill response. This dissertation also performs a detailed qualitative and quantitative assessment of the impact of various forcing functions on wave pre- dictions, and develops maps showing extreme variations in significant wave heights (SWHs). For instance, it is found that the SWH could vary by as much as 1 m in the northern CI region in the presence of currents (hence justifying the need for integration of the wave model with a circulation model). Such maps can be useful for several engineering operations, and could also serve as guidance tool as to what can be expected in certain regions. Aside from the system development, the issue of forecast reliability is also addressed for PWS region in the context of the associated uncertainty which confronts the manager of engineering operations or other planners. For this purpose, high-resolution 36-h daily forecasts of SWHs are compared with measurements from buoys and satellites for about a year. The results show that 70% of the peak SWHs in the range 5-8 m were predicted with an accuracy of 15% or less for a forecast lead time of 9 h. On average, results indicate 70% or greater likelihood of the prediction falling within a tolerance of ±(1*RMSE) for all lead times. This analysis could not be performed for CI due to lack of data sources

A Cost Effective Alternative To Credit Rating Specifically For Smes In India

Journalist Thomas Friedman once said, “There are two superpowers in the world today. There’s the United States and there is Moody’s bond rating services. The US can destroy by dropping bombs and Moody’s can destroy you by downgrading your bonds. Rating agencies play a key role in the infrastructure of modern financial system. The origins of Credit Rating can be traced to the 1840s, following the financial crisis of 1837, Louis Tappan established the first mercantile credit agency in New York in 1841. The agency rated the ability of merchants to pay their financial obligations. It was subsequently acquired by Robert Dun and its first rating guide was published in 1859. Another similar agency was setup by John Bradsheet in 1849, which published a rating book in 1857. 0These two agencies were merged together to form Dun and Bradsheet, in 1933, which became the owner of Moody’s investor service in 1962

Hybrid Data Acquisition and Analysis System for Flowing Medium Lasers

The medium gas lasers involves in-situ generation of the lasing medium, hence are associated with several complex processes including mixing of pumping and lasing species, energy exchange between the species, heat generation during reaction and its influence on the flow domain to list a few. Thus, the characterisation of lasing medium, condition of operation of individual critical subsystems and corresponding phenomenon thereof is essential in real time. It is here that a customised data acquisition and analysis system (DAAS) plays a key role. The paper dwells on the realisation of a customised hybrid DAAS with a master-slave architecture, which is portable and provides remote system operation. The noteworthy aspects of the developed DAAS include capability to handle close to 150 channels [64 analog input, 64 digital output, 5 analog output and 17 digital input] simultaneously with varied sampling rates requirement ranging from 100 samples/s to 200 k samples/s, modularity in design enabling scalability. Further, the efficacy of the developed DAAS has been tested by conducting several real time experiments with an existing chemical oxygen iodine laser source with a mass flow rate of 2.3 moles.s-1 both from close ranges and at line of sight remote distances of up to 80 m and nearly 35 m with obstacles

Data Acquisition System for Chemical Iodine Generation Suitable for Flowing Medium Chemical Oxygen Iodine Laser

Development of infrared flowing medium lasers needs to be envisaged in a manner that practical aspects such as system compactness, short readiness time, low system size, weight and power are met to make them field deployable. In this context, the critical aspect of in-situ production of lasing species (Iodine) in Chemical Oxygen Iodine Lasers (COIL), one of the most potent flowing medium lasers, has been investigated. The paper dwells on chemical generation of iodine and its precise flow and parameter control by implementing a customised Data Acquisition System (DAS). Iodine is generated in a chemical reaction of Cuprous Iodide (CuI) with chlorine. This is achieved by precisely controlled flow of chlorine diluted with a carrier gas (N2 ) in a ratio of 1:2. DAS includes regulated gas feed, accurate thermal stabilisation, relevant diagnostics and implementation of necessary safety interlocks in a real time operation scenario for establishing the system efficacy and scalability. The studies have demonstrated chemically generated iodine flow rate of ~ 1.2 mmol.s-1 for Cl2 flow rate of ~3 mmol.s-1 all measured in real time using the developed DAS with a conversion efficiency of 80%. Developed I2 supply system has potential to deliver iodine on demand with required flow rates, measurement uncertainty of ~ 4.5 percent and advantages of smaller specific weight and size with reduced system readiness time and electrical power supply using DAS system with adequate safety interlocks

Hyperuricemia as a risk factor for increase severity of coronary vessel occlusion disease: a cross-sectional study in North Indian population

Background: Cardiovascular disease (CVD) is the most common cause of death worldwide. The present study was conducted to study uric acid as a potential biomarker in predicting the severity of CVD in terms of vessel involvement.Methods: A cross-sectional study, conducted at Rajiv Gandhi Super Speciality Hospital, Tahirpur, Delhi. A total of 52 consecutive male and female patients age between 30 to 70 years was included in this study. Written informed consent was obtained from all the enrolled patients. Automated analysers were used for the analysis of blood glucose, lipid profile and serum uric acid level. IBM SPSS Statistics (Version 20.0, IBM SPSS, IL, USA) was used for the statistical analyses.Results: In this study, a total of 52 consecutive patients were divided into three groups; single-vessel disease (n=19), double vessel disease (n=19) and triple vessel disease (n=14). Biochemical profile of all the groups was calculated. A group of triple vessel disease patients showing higher amount (164±42 mg/dl) of cholesterol level as compared to the other two groups (157±34 mg/dl). The mean level of serum uric acid levels significantly differed and its mean levels increases as the severity of vessel diseases increases. The receiver operating characteristic curve shows the uric level has 71% sensitivity and 52.5% specificity for detecting the severity of coronary vessel disease.Conclusions: This study demonstrated an increased serum uric acid levels were associated with increased severity of vessel disease, and serum uric acid is an independent risk factor for coronary artery disease