Search results for "total"

Effect of the conversion of mangroves into shrimp farms on carbon stock in the sediment along the southern Red Sea coast, Saudi Arabia

2019

The conservation of coastal ecosystems and specially mangroves ‘‘blue carbon’’ is receiving more attention as consequence of their recognition as high ecosystem carbon stocks and for the fact that these areas are undergoing land conversion. The aim of the present study is to evaluate the impact of land use changes due to conversion of mangroves to shrimp farms on the bulk density (SBD), organic carbon (SOC) concentration, and SOC stock in the sediments along the southern Saudi Arabian Red Sea coast. Shrimp farms and mangrove locations showed significant (P < 0.001) differences in SBD with high mean values in the sediments of shrimp farms. Shrimp farms and mangrove locations showed significa…

Recanalization of Totally Occluded Coronary Vessels by Percutaneous Transluminal Coronary Angioplasty

1986

Since its introduction in 1977, percutaneous transluminal coronary angioplasty (PTCA) has become an effective approach for treatment of patients with single-vessel disease [1–3, 5]. Treatment of double- and multiple-vessel disease has also been attempted [5, 6]. In patients with angina pectoris total occlusion of coronary vessels is found, and PTCA has also been used in an attempt to restore coronary blood flow in such patients [8, 10]. Even main stem occlusions have been recanalized [11]. In patients with total occlusion of coronary vessels, collateral flow is sufficient to maintain cardiac function at rest but not during exercise [12–14]. Therefore, PTCA seems to be an ideal method for re…

Dificultad en el tratamiento del hipertiroidismo por amiodarona: Presentación de un caso

2007

La amiodarona puede alterar la función tiroidea en un 15-20% de los pacientes que la toman, dando lugar a hipotiroidismo o hipertiroidismo. La sobrecarga de yodo y la toxicidad directa sobre el tiroides inducida por amiodarona pueden provocar hipertiroidismo. Describimos un caso de tirotoxicosis grave por amiodarona que se diagnosticó buscando la causa que descompensó la cardiopatía de base del paciente, condicionando ésta el pronóstico y el manejo terapéutico. El tratamiento precisó un estrecho seguimiento y se basó en dosis elevadas de propiltiouracilo y dexametasona que no controlaron las consecuencias del hipertiroidismo a nivel cardiaco necesitando la tiroidectomia total. Creemos, con …

Friedel-Crafts Alkylation of Arenes in Total Synthesis

2015

High efficiency of Pt2+ - CeO2 novel thin film catalyst as anode for proton exchange membrane fuel cells

2016

Abstract The elevated price of Pt limits the large-scale implementation of commercial proton exchange membrane fuel cells, which effectively convert chemical energy into electricity. In order to increase the cost-efficiency in proton-exchange membrane fuel cells, we have designed a family of novel anode catalysts consisting of thin films of ceria with low Pt loadings sputtered on a nanostructured carbon support. Remarkably, only such small amounts of Pt are necessary for achieving power density values comparable to the reference commercial catalysts, which results in excellent specific activities of our samples. By combining photoelectron spectroscopy and catalytic performance analysis, we …

Channel Tracking Guidewire and Technique for Retrograde Approach

2020

Evaluation of the collateral circulation is critical for determining the feasibility of the retrograde approach. When assessing collateral channels it is of paramount importance to take time and review the previous angiogram carefully, for multiple potential collateral pathways, as the predominant collateral may change over time prior to the procedure. Careful review of collaterals prior to the procedure can reduce contrast and radiation dose as well as the duration of the procedure.Retrograde access to the distal vessel can be achieved via septal collaterals, epicardial collaterals (atrial channel), or (patent or occluded) coronary bypass grafts. Generally septals are used more often 65–70…

ChemInform Abstract: Organocatalytic Approach to Benzofused Nitrogen-Containing Heterocycles: Enantioselective Total Synthesis of (+)-Angustureine.

2009

Atmospheric compensation in Fourier transform infrared (FT-IR) spectra of clinical samples.

2013

A new method is proposed for the elimination of the spectral contribution of two atmospheric gases (CO2 and H2O) in Fourier transform infrared (FT-IR) spectra of clinical samples. The algorithm is based on the measurement of reference spectra of H2O followed by an automatic calculation of the spectral contribution of the above-mentioned gases to the sample spectra. Then this contribution is compensated by spectral subtraction. Attenuated total reflectance FT-IR spectra of serum and urine samples in the presence of atmospheric gases were corrected and compared with spectra obtained with an N2 purge. Visual inspection of the spectra as well as calculated noise levels confirmed that the metho…

Electrosynthesis of Poly(alanine)-Like Peptides in Concentrated Alanine Based Electrolytes, Characterization Coupled to DFT Study and Application to …

2014

The anodic oxidation of concentrated l-alanine on smooth electrodes such as platinum and glassy carbon electrodes was studied. Contrary to the previous studies performed up to now with diluted l-alanine, the electrochemical process generated here results in a completely different situation. The oxidation on smooth platinum was carried out by electrochemical quartz crystal microbalance (EQCM) coupled to cyclic voltammetry technique. The effects of concentration, scan rate, and pH (zwitterion at pH = 6 and alkaline media at pH = 13) on potential values were examined. Glassy carbon and smooth gold electrodes showed the same behavior as on smooth platinum electrode. Spectroscopic analysis such …

Sicilian bottled natural waters: Major and trace inorganic components

2013

Sixteen bottled waters of various Sicilian brands, 11 natural mineral waters and five normal drinking waters, were analyzed for major and trace inorganic components by ion chromatography (IC) and inductively coupled plasma-mass spectrometry (ICP-MS), respectively. The bottled waters represent a variety of water types with significantly different compositions in terms of salinity, major components and trace elements. Chemically, they range from Ca–HCO3 and Ca–SO4 to Na–HCO3 types. Total dissolved solids ranges from 54 to 433 mg/L, total hardness from 25 to 238 mg/L CaCO3, and measured Na content from 5.7 to 57 mg/L. According to total dissolved ions, all the bottled waters were classified as…