Role of Zeolite Structural Properties toward Iodine Capture: A Head-to-head Evaluation of Framework Type and Chemical Composition.

This study evaluated zeolite-based sorbents for iodine gas [I2(g)] capture. Based on the framework structures and porosities, five zeolites, including two faujasite (FAU), one ZSM-5 (MFI), one mesoMFI, one ZSM-22 (TON), as well as two mesoporous materials, were evaluated for I2(g) capture at room temperature and 150 °C in an iodine-saturated environment. From these preliminary studies, the three best-performing zeolites were ion-exchanged with Ag+ and evaluated for I2(g) capture under similar conditions. Energy-dispersive X-ray spectroscopy data suggest that Ag-FAU frameworks were the materials with the highest capacity for I2(g) in this study, showing ∼3× higher adsorption compared to Ag-mordenite (Ag-MOR) at room temperature, but X-ray diffraction measurements show that the faujasite structure collapsed during the adsorption studies because of dealumination. The Ag-MFI zeolites are decent sorbents in real-life applications, showing both good sorption capacities and higher stability. In-depth analyses and characterizations, including synchrotron X-ray absorption spectroscopy, revealed the influence of structural and chemical properties of zeolites on the performance for iodine adsorption from the gas phase.

Reproduction of melting behavior for vitrified hillforts based on amphibolite, granite, and basalt lithologies.

European Bronze and Iron Age vitrified hillforts have been known since the 1700s, but archaeological interpretations regarding their function and use are still debated. We carried out a series of experiments to constrain conditions that led to the vitrification of the inner wall rocks in the hillfort at Broborg, Sweden. Potential source rocks were collected locally and heat treated in the laboratory, varying maximum temperature, cooling rate, and starting particle size. Crystalline and amorphous phases were quantified using X-ray diffraction both in situ, during heating and cooling, and ex situ, after heating and quenching. Textures, phases, and glass compositions obtained were compared with those for rock samples from the vitrified part of the wall, as well as with equilibrium crystallization calculations. 'Dark glass' and its associated minerals formed from amphibolite or dolerite rocks melted at 1000-1200 °C under reducing atmosphere then slow cooled. 'Clear glass' formed from non-equilibrium partial melting of feldspar in granitoid rocks. This study aids archaeological forensic investigation of vitrified hillforts and interpretation of source rock material by mapping mineralogical changes and glass production under various heating conditions.

Venous System Interventions for Device Implantation.

Subclavian obstruction is common after lead implantation and the need to add or replace a lead is increasing. Subclavian venoplasty (SV) is a safe and effective option for venous occlusion. Peripheral venography overestimates the severity of the obstruction. A wire can usually be advanced into the central circulation for SV. Compared with dilators, SV improves the quality of venous access, providing unrestricted catheter manipulation for His bundle pacing and left ventricular lead implantation. SV preserves venous access and reduces lead burden. SV can easily be added to the implanting physicians lead management options.

Inflammation, Obesity and the Metabolic Syndrome. Implications in Hispanics.

We report clinical and molecular mechanisms relating the process of inflammation involved in the progression of obesity and the metabolic syndrome, emphasizing the cardiovascular problems developed in Hispanic populations. Namely, the incidence, component characteristics and complications of obesity and metabolic syndrome in island Puerto Ricans are described and evidence is presented supporting the fact that the metabolic syndrome may be milder in Puerto Rico than in the mainland United States because it is characterized by less aggressive coronary artery disease and a relatively normal lipid profile. Moreover, data supports the fact that increased serum cholesterol levels produce less myocardial infarctions in Puerto Rico than in mainland Hispanics and Caucasians. In addition, the incidence of ventricular tachycardia, a complication caused by remodeling and ischemia of the heart, may be lower in Puerto Rico than in the United States, although the prevalence of the metabolic syndrome is higher in the island. On the other hand, there is evidence of a rising epidemic of obesity and vascular inflammation in Puerto Rico that suggests that cardiovascular morbidity and mortality in the island will continue to increase in the future decades.

Coronary levels of angiotensin-II and endothelin-I in diabetic patients with and without coronary artery disease.

Two groups of patients were studied to find out the levels of angiotensin-II and endothelin-I in the coronary and peripheral circulation. Group A consisted of eight patients with diabetes mellitus type 2 and coronary artery disease; and Group B with diabetes mellitus without coronary artery disease. Significant differences were found between Group A and B in the levels of both peptides peripherally and intracoronary. This shows the importance of these peptides in the origin of coronary artery disease and progression of the disease in diabetics with coronary artery disease.

Non-Invasive Therapy of Peripheral Arterial Disease.

Peripheral arterial disease (PAD) is a significant cause of morbidity and mortality worldwide. Lifestyle changes, like the cessation of the use of tobacco as well as a modification of dietary and exercise habits, can be the most cost-effective interventions in patients with PAD. Smocking cessation is the most important intervention, since it increases survival in these patients. Antiplatelet therapy is an essential component in the treatment of peripheral arterial disease (PAD) of the lower extremities. In addition to delaying arterial obstructive progression, these agents are most usefull in reducing adverse cardiovascular events such as non-fatal myocardial infarction (MI), stroke and vascular death. Mainstay of treatment continues to be aspirin monotherapy (75-325mg daily). Current treatment for lower extremity PAD is directed towards the relief of symptoms and improvement in QoL. The two agents which have consistently been found to be most efficient in achieving these goals are cilostazol and naftidrofuryl oxalate. Naftidrofuryl oxalate may emerge as the most efficient and cost-effective treatment for symptom relief.

Obesity and premature coronary artery disease with myocardial infarction in Puerto Rican young adults.

A cross-sectional study examined adults aged 21 to 35 years who underwent left cardiac catheterization in the Cardiovascular Center for Puerto Rico and the Caribbean during 2008-2012 due to myocardial infarction. Demographic characteristics, clinical risk factors, and the extent of CAD were documented. Chi-square statistic or Fisher's exact test was used to compare the distribution of demographic, clinical, and lifestyle characteristics across CAD extent. Polytomous logistic regression models were fitted to estimate the prevalence odds ratios (POR) with 95% confidence intervals (Cl) for non-obstructive and obstructive coronary disease (OCD) compared with normal coronary anatomy. Statistical analyses were performed using Stata 11.0. Sixty-three (n = 63) adults were evaluated (81% were men). The mean age was 31 ± 4 years. The most frequent clinical risk factors were history of tobacco use, hyper tension, and dyslipidemia. Obesity was present in 45.9% of subjects and OCD was present in 52.38% of subjects. Obesity and family history of CAD were significantly associated with OCD when adjusted by age. Obese patients had 5.94 times the possibility of having OCD than normal weight patients. Obesity was the most important treatable predictor of premature obstructive CAD in our young adult population.

Effect of bubbles and silica dissolution on melter feed rheology during conversion to glass.

Nuclear-waste melter feeds are slurry mixtures of wastes with glass-forming and glass-modifying additives (unless prefabricated frits are used), which are converted to molten glass in a continuous electrical glass-melting furnace. The feeds gradually become continuous glass-forming melts. Initially, the melts contain dissolving refractory feed constituents that are suspended together with numerous gas bubbles. Eventually, the bubbles escape, and the melts homogenize and equilibrate. Knowledge of various physicochemical properties of the reacting melter feed is crucial for understanding the feed-to-glass conversion that occurs during melting. We studied the melter feed viscosity during heating and correlated it with the volume fractions of dissolving quartz (SiO2) particles and the gas phase. The measurements were performed with a rotating spindle rheometer on the melter feed heated at 5 K/min, starting at several different temperatures. The effects of undissolved quartz particles, gas bubbles, and compositional inhomogeneity on the melter feed viscosity were determined by fitting a linear relationship between the logarithm of viscosity and the volume fractions of suspended phases.

Ethnicity and genetics are more important than diabetes mellitus and hypertension in producing cardiovascular events in patients with the metabolic syndrome: emphasis in the Puerto Rico population.

Metabolic syndrome is a cluster of risk factors for cardiovascular disease that affects an estimated 50 million Americans. The present article reviews the metabolic syndrome with respect to its definition, epidemiology, pathophysiology and management. A primary focus in research has been to elucidate the processes determined to cause insulin resistance, the fundamental mechanism underlying the metabolic syndrome. Namely, the incidence, component characteristics and complications of the metabolic syndrome in the island of Puerto Rico are described alongside the fact that the metabolic syndrome may be milder in Puerto Rico than in the mainland United States because it is characterized by less aggressive coronary disease and a relatively normal lipid profile. This suggests that the cardiovascular complications are more influenced by genetics and culture than diabetes mellitus and hypertension.

Metabolic syndrome among Puerto Ricans and other Hispanic populations.

Metabolic syndrome is a cluster of risk factors for cardiovascular disease that affects an estimated 50 million Americans. The present article reviews this syndrome with respect to its definition, epidemiology, pathophysiology, and management. A primary focus in research has been to elucidate the processes that have been determined to cause insulin resistance, the fundamental mechanism underlying metabolic syndrome; these processes are reviewed here along with the interplay of the syndrome with the renin-angiotensin system, circadian rhythm, and atherosclerosis. Lifestyle changes promoting exercise and a healthy diet can reduce the incidence and prevent the progression of metabolic syndrome; however, refractory cases may warrant drug therapy. Recent emphasis has been placed on targeting obesity and insulin resistance as new therapeutic modalities are developed. In this manuscript, the incidence, component characteristics, and complications of metabolic syndrome in island-living Puerto Ricans and other Hispanic populations are described. The fact that island patients suffering from the syndrome tend to have less aggressive coronary disease and relatively normal lipid profile compared to their stateside counterparts is also discussed.