A hydrophobic deep eutectic solvent-based microextraction for the determination of ultra-trace arsenic in foods by an electrothermal atomization atomic absorption spectrometry.

A hydrophobic deep eutectic solvent-based liquid-phase microextraction approach for the determination of ultra-trace arsenic (total) in foods by an electrothermal atomization atomic absorption spectrometry was developed. Various deep eutectic solvents based on tetraoctylammonium bromide and fatty acids (heptanoic, octanoic, nonanoic, decanoic acids) were studied as extraction solvents for preconcentration of arsenic (V) from mineralizates obtained after a microwave digestion of food samples. Phenomenon of ion-pairs formation between dihydroarsenate and precursor of deep eutectic solvent (tetraoctylammonium) and mass-transfer of the ion-pairs into deep eutectic solvent phase was presented for the first time.

Russian collection of vaccine strains: annotation, implementation and genomic analysis.

Over the past 10 years, immunization of cattle in Russia has been performed using vaccines from strains 82, 19 and 75/79. To prevent brucellosis in small ruminants, two vaccines have been used, from the strain REV-1 and the strain 19; note that twice as many animals have been immunized with the former vaccine than with the latter vaccine. The disadvantage of using these preparations is the formation of prolonged post-vaccination seropositivity, which is especially pronounced in animals after immunization with vaccines from strain 19 and strain REV-1.

Whole-genome sequencing of strains isolated in Russia.

Background And Aim: is a Gram-negative bacterium belonging to the family that can cause bovine histophilosis. may act as a commensal or opportunistic bacterial cattle pathogen. Comparing genomes of the pathogenic strain 2336 with the non-pathogenic preputial 129Pt isolate revealed some putative virulence factors.

An effervescence-assisted dispersive liquid-liquid microextraction based on three-component deep eutectic solvent for the determination of fluoroquinolones in foods.

An effervescence-assisted dispersive liquid-liquid microextraction approach using three-component deep eutectic solvent based on short-chain and medium-chain carboxylic acids and terpenoid was developed for the first time. The microextraction procedure was applied to the determination of fluoroquinolone antibiotics in foods (milk and shrimp samples) by high-performance liquid chromatography with fluorometric detection. In this microextraction procedure three-component deep eutectic solvent acted as a proton donor agent and an extractant.

A derivatization and microextraction procedure with organic phase solidification on a paper template: Spectrofluorometric determination of formaldehyde in milk.

A derivatization and air-assisted dispersive liquid-liquid microextraction procedure with organic phase solidification on a paper template was developed for the first time. The procedure was used for the spectrofluorometric determination of formaldehyde in milk samples. The Hantzsch reaction of formaldehyde with acetylacetone in the presence of ammonia to form a derivative (3,5-diacetyl-1,4-dihydrolutidine) was implemented for the microextraction and detection of analyte.

p-Dimethylaminobenzaldehyde-based chemosensor for on-site sensing of ammonia precursor in concrete.

A chemosensor for on-site sensing of ammonia precursor in concrete to avoid a problem of ammonia emission into the indoor space of concrete buildings was designed and implemented. It was found that aqueous extracts of concrete samples containing antifreeze additives and excreting ammonia were colored in the presence of p-dimethylaminobenzaldehyde. This phenomenon was used for the fast visual sensing of main ammonia precursor (urea) in concrete for the first time.

In-a-syringe surfactant-assisted dispersive liquid-liquid microextraction of polycyclic aromatic hydrocarbons in supramolecular solvent from tea infusion.

In this work, an automated surfactant-assisted dispersive liquid-liquid microextraction approach based on in-a-syringe concept was developed for the first time. The procedure assumed mixing aqueous sample phase and hydrophilic emulsion containing hexanoic acid and sodium hexanoate in a syringe of flow system. Sodium hexanoate acted as an emulsifier in dispersive liquid-liquid microextraction process and it was required for the formation of supramolecular solvent phase.

Learning From Controversy: Contemporary Surgical Management of Aortic Valve Endocarditis.

Aortic valve replacement is the commonest cardiac surgical operation performed worldwide for infective endocarditis (IE). Long-term durability and avoidance of infection relapse are goals of the procedure. However, no detailed guidelines on prosthesis selection and surgical strategies guided by the comprehensive evaluation of the extension of the infection and its microbiological characteristics, clinical profile of the patient, and risk of infection recurrence are currently available.

Mitral regurgitation: lessons learned from COAPT and MITRA-Fr.

Recent studies about percutaneous treatment of secondary mitral regurgitation (MR) underlined the importance of left ventricular geometry and features of mitral valve as determinants of procedural and long-term success. Guideline-directed medical therapy (GDMT), transcatheter mitral valve treatment (TMVT) and surgical procedures (mitral valve replacement, mitral valve repair at level of the annulus or subvalvular apparatus) have been extensively evaluated but not adequately compared in current clinical studies. A detailed analysis of the results of the study about transcatheter mitral valve repair would allow to evaluate the safety and effectiveness of such procedure and would provide potential indications for improving the quality of percutaneous and surgical repair in patients with moderate-to-severe secondary MR.

Mitral regurgitation after transcatheter aortic valve replacement.

Unlabelled: Patients undergoing transcatheter aortic valve replacement (TAVR) might have an associated significant MR that can potentially lead to left ventricular (LV) failure after procedure. Considering the specific alterations in the mitral valve in TAVR scenario and the widespread use of TAVR in recent years, it appears important to know and understand the anatomical, functional and clinical implications to develop adequate strategies for the future. Patients with severe mitral regurgitation (MR) have been generally excluded from randomized clinical trials, making poor the impact that associated MR can have on clinical outcomes after TAVR.

Are the dynamic changes of the aortic root determinant for thrombosis or leaflet degeneration after transcatheter aortic valve replacement?

The role of the aortic root is to convert the accumulated elastic energy during systole into kinetic flow energy during diastole, in order to improve blood distribution in the coronary tree. Therefore, the sinuses of Valsalva of the aortic root are not predisposed to accept any bulky material, especially in case of uncrushed solid calcific agglomerates. This concept underlines the differences between surgical aortic valve replacement, in which decalcification is a main part of the procedure, and transcatheter aortic valve replacement (TAVR).

The Radial Artery for Coronary Bypass Grafting: The Fifth Decade.

Background: In 1989, we reported the use of the radial artery as a second target conduit for coronary artery bypass grafting. However, underpowered randomized trials have reported differences in clinical outcomes between the radial artery and other grafts. As we approach 50 years of experience with radial artery grafting, we reviewed the literature to determine the second-best target vessel for coronary operations.

A simple and highly-available microextraction of benzoic and sorbic acids in beverages and soy sauce samples for high performance liquid chromatography with ultraviolet detection.

A simple and highly-available air-assisted dispersive liquid-liquid microextraction procedure with organic phase solidification (AA-DLLME-OPS) was developed as new approach for pretreatment of complex sample matrix. Menthol was investigated as novel extractant for the AA-DLLME-OPS. In this procedure, a cloudy solution of fine molten menthol droplets is formed when a mixture of molten menthol and aqueous sample is rapidly aspirated into a dispenser and injected into an extraction vial.

FeO-based composite magnetic nanoparticles for volatile compound sorption in the gas phase: determination of selenium(iv).

In this study, Fe3O4-based composite magnetic nanoparticles were found to separate volatile compounds directly in the gas phase for the first time. The phenomenon of H2Se sorption on the magnetic nanoparticles was studied in detail and applied for separation and preconcentration. The developed approach was applied for the determination of selenium in dietary supplement samples after microwave digestion by ETA-AAS as a proof-of-concept example.

Flow analysis with chemiluminescence detection: Recent advances and applications.

This article highlights the most important developments in flow analysis with chemiluminescence (CL) detection, describing different flow systems that are compatible with CL detection, detector designs, commonly applied CL reactions and approaches to sample treatment. Recent applications of flow analysis with CL detection (focusing on outputs published since 2010) are also presented. Applications are classified by sample matrix, covering foods and beverages, environmental matrices, pharmaceuticals and biological fluids.

An evaporation-assisted dispersive liquid-liquid microextraction technique as a simple tool for high performance liquid chromatography tandem-mass spectrometry determination of insecticides in wine.

A sample pre-treatment technique based on evaporation-assisted dispersive liquid-liquid microextraction (EVA-DLLME), followed by HPLC-MS/MS has been developed for the determination of organophosphate insecticides (malathion, diazinon, phosalone) in wine samples. The procedure includes the addition of mixture of organic solvents (with density higher than water), consisting of the extraction (low density) and volatile (high density) solvents, to aqueous sample followed by heating of the mixture obtained, what promotes the volatile solvent evaporation and moving extraction solvent droplets from down to top of the aqueous sample and, as a consequence, microextraction of target analytes. To initiate the evaporation process an initiator is required.

Switchable hydrophilicity solvent membrane-based microextraction: HPLC-FLD determination of fluoroquinolones in shrimps.

A switchable hydrophilicity solvent membrane-based microextraction (SHS-MME) strategy for simple and highly-available sample pretreatment of complex matrices has been proposed. The SHS-MME procedure based on extraction of target analytes from an aqueous sample into a porous hydrophobic membrane impregnated with a switchable hydrophilicity solvent (SHS) followed by SHS ionization and back-extraction of the analytes in alkaline acceptor solution. The medium-chain fatty acids were investigated as SHS for the SHS-MME of fluoroquinolones (fleroxacin, lomefloxacin, norfloxacin and ofloxacin).

On-line in-syringe sugaring-out liquid-liquid extraction coupled with HPLC-MS/MS for the determination of pesticides in fruit and berry juices.

A fully automated method for the determination of pesticides (malathion, diazinon, imidacloprid and triadimefon) in fruit and berry juices has been developed. In the current study, the on-line in-syringe sugaring-out liquid-liquid extraction was successfully combined with a HPLC-MS/MS system for the first time. The procedure assumes the liquid-liquid extraction of analytes in water-miscible organic solvent acetonitrile followed by phase separation using glucose as sugaring-out reagent.

A dispersive liquid-liquid microextraction using a switchable polarity dispersive solvent. Automated HPLC-FLD determination of ofloxacin in chicken meat.

In this article, dispersive liquid-liquid microextraction (DLLME), based on the use of so-called switchable polarity dispersive solvent (SPDS) for microextraction, is presented for the first time. The new extraction technique makes use of a mixture of extraction solvent (dichloromethane) and the SPDS (acrylic acid). This mixture is injected into the aqueous sample solution, which was previously fortified with the alkaline agent (NaOH).

Flow Analysis: A Novel Approach For Classification.

We suggest a novel approach for classification of flow analysis methods according to the conditions under which the mass transfer processes and chemical reactions take place in the flow mode: dispersion-convection flow methods and forced-convection flow methods. The first group includes continuous flow analysis, flow injection analysis, all injection analysis, sequential injection analysis, sequential injection chromatography, cross injection analysis, multi-commutated flow analysis, multi-syringe flow injection analysis, multi-pumping flow systems, loop flow analysis, and simultaneous injection effective mixing flow analysis. The second group includes segmented flow analysis, zone fluidics, flow batch analysis, sequential injection analysis with a mixing chamber, stepwise injection analysis, and multi-commutated stepwise injection analysis.

A gas-diffusion flow injection method coupled with online solid-liquid extraction for the determination of ammonium in solid samples.

A simple, rapid and reliable gas-diffusion flow injection (GD-FI) method for ammonium determination in building materials has been developed. It is based on leaching ammonium from a ground solid sample into an alkaline solution with subsequent ammonia gas generation. Ammonia is then transported in a nitrogen stream to the GD cell of the FI system where it is absorbed into its acceptor solution containing a mixture of the acid-base indicators cresol red and thymol blue.

Automated procedure for determination of ammonia in concrete with headspace single-drop micro-extraction by stepwise injection spectrophotometric analysis.

A novel automatic stepwise injection headspace single-drop micro-extraction system is proposed as a versatile approach for automated determination of volatile compounds. The system application is demonstrated for ammonia determination in concrete samples. An ammonia gas was produced from ammonium ions and extracted on-line into 5 μL 0.

Risk factors for intimate partner violence against women in St. Petersburg, Russia.

This exploratory study examines which risk factors are associated with intimate partner violence against women in St. Petersburg, Russia. Women attending two crisis centers and a birthing house constituted the study sample.