Cement classification and characterization using Non-Invasive techniques.

Cement is one of the most widely used materials in the global construction industry, serving as an adhesive and binder in projects that require strength and durability. Additionally, cement production indicates a country's development and economic activity, with global production reaching approximately 4 billion tons annually. It is a fine powder composed mainly of lime, silica, iron oxide, and alumina.

[Disappearing bone disease of the shoulder (Gorham-Stout Syndrom)].

The spontaneous disappearance of a segment of bone in a short period without the existence of a tumoral disease that justifies it is an exceptional event. We report the case of an older adult in whom the upper epiphysis of the right humerus and part of the acromion disappeared in a period of 3 weeks in the absence of a malignant tumor. Bone biopsy revealed osteoclasts, lymphatic vessels, and blood vessels.

A new constraint to model background signals when processing chromatographic-spectral second-order data with multivariate curve resolution.

Background: the chemometric processing of second-order chromatographic-spectral data is usually carried out with the aid of multivariate curve resolution-alternating least-squares (MCR-ALS). When baseline contributions occur in the data, the background profile retrieved with MCR-ALS may show abnormal lumps or negative dips at the position of the remaining component peaks.

Results: The phenomenon is shown to be due to remaining rotational ambiguity in the obtained profiles, as confirmed by the estimation of the boundaries of the range of feasible bilinear profiles.

[Bacterial infections in COVID-19 patients hospitalized in intensive care unit].

In this brief communication, we retrospectively describe COVID-19 severe patient's characteristics in ICU, and report 37,6% of secondary bacterial infections, mainly with nosocomial respiratory infections and rarely from community source.

Rhino-orbito-cerebral mucormycosis in an acute lymphoblastic leukemia pediatric patient. Case report and review of literature.

Mucormycosis is a disease caused by opportunistic fungi of the order Mucorales that generally affects immunocompromised patients or those with underlying disease. It has a high mortality rate and is the third most common invasive fungal infection. The following is a case report of a 12-year-old pediatric patient diagnosed with B-cell acute lymphoblastic leukemia, who presented an aggressive infectious disease two months after beginning chemotherapy, which began in the right frontal and maxillary sinuses, with subsequent progression and extension, progressively deteriorating the patient's clinical status.

Perioperative chemotherapy in locally advanced gastric cancer in Chile: from evidence to daily practice.

Gastric cancer (GC) is a leading cause of cancer death in Chile. Although recommended in international guidelines since 2006, perioperative chemotherapy was not available to patients in the public health system in Chile until 2016. We conducted an observational study to assess the feasibility of this strategy in public hospitals in Chile (Observational Study of Perioperative Chemotherapy in Locally Advanced Gastric Cancer - PRECISO).

Identification of optimal therapeutic window for steroid use in severe alcohol-associated hepatitis: A worldwide study.

Background & Aims: Corticosteroids are the only effective therapy for severe alcohol-associated hepatitis (AH), defined by a model for end-stage liver disease (MELD) score >20. However, there are patients who may be too sick to benefit from therapy. Herein, we aimed to identify the range of MELD scores within which steroids are effective for AH.

[Acute hepatitis C. Report of seven cases].

Hepatitis C virus infection is a major global public health problem. Treatment with direct-acting antivirals is intended to eradicate the chronic form of this infection by 2030. Although uncommon, the acute form of presentation is increasingly recognized, especially in some high-risk populations, such as men who have sex with men without protection.

Interpretation of matrix chromatographic-spectral data modeling with parallel factor analysis 2 and multivariate curve resolution.

Parallel factor analysis 2 (PARAFAC2) is still being advocated for the processing of second-order chromatographic-spectral data, both for qualitative and quantitative applications. However, neither classical PARAFAC2 nor the newly developed flexible non-negative NN-PARAFAC2 version can adequately model these data in a general situation. In quantitative analysis, considerable bias may result in the estimation of analyte concentrations, due to the fact that both PARAFAC2 models apply an artificial constraint to the retrieved profiles, requiring constant cross-product, i.

Effect of a Resuscitation Strategy Targeting Peripheral Perfusion Status vs Serum Lactate Levels on 28-Day Mortality Among Patients With Septic Shock: The ANDROMEDA-SHOCK Randomized Clinical Trial.

Importance: Abnormal peripheral perfusion after septic shock resuscitation has been associated with organ dysfunction and mortality. The potential role of the clinical assessment of peripheral perfusion as a target during resuscitation in early septic shock has not been established.

Objective: To determine if a peripheral perfusion-targeted resuscitation during early septic shock in adults is more effective than a lactate level-targeted resuscitation for reducing mortality.

Excitation-emission fluorescence-kinetic third-order/four-way data: Determination of bisphenol A and nonylphenol in food-contact plastics.

The endocrine disrupting chemicals bisphenol A (BPA) and 4-nonylphenol (NP) were simultaneously quantified through third-order/four-way calibration. Excitation-emission fluorescence matrix-kinetic (EEFM-K) third-order data were generated by measuring the EEFMs of these priority xenoestrogens as a function of reaction time during their Fenton degradation. Third-order/four-way calibration notably improves the sensitivity of the method and provides the required selectivity for quantifying analytes with critically overlapped fluorescence signals.

Multivariate curve resolution strategy for non-quadrilinear type 4 third-order/four way liquid chromatography-excitation-emission fluorescence matrix data.

For the first time, a third-order/four-way system having instrumental modes depending on each other was experimentally generated and it was successfully resolved. Non-quadrilinear type 4 data, constituted by liquid chromatographic elution times (LC) and excitation-emission fluorescence matrices (EEFMs), were on-line measured using conventional equipment. Thus, third-order/four-way data, valuable for giving rise to highly sensitive and selective methods, were obtained minimizing significantly the experimental work and time, in comparison with the reported strategies for the acquisition of LC-EEFM data.

On-line generation of third-order liquid chromatography-excitation-emission fluorescence matrix data. Quantitation of heavy-polycyclic aromatic hydrocarbons.

For the first time, third-order liquid chromatography with excitation-emission fluorescence matrix detection (LC-EEFM) data were generated on-line and chemometrically processed for the simultaneous quantitation of the heavy-polycyclic aromatic hydrocarbons fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, and dibenz[a,h]anthracene. The applied experimental strategy is very simple, and is based on the reduction of the linear flow rate by fitting a larger diameter connecting-tube between the column outlet and the fluorimetric detector. In this way, EEFMs were successfully recorded on-line, without involving a large total analysis time.

Multivariate curve resolution applied to kinetic-spectroscopic data matrices: Dye determination in foods by means of enzymatic oxidation.

In this work, the combination of chemometric techniques with kinetic-spectroscopic data allowed quantifying two dyes (tartrazine and carminic acid) in complex matrices as mustard, ketchup, asparagus soup powder, pumpkin soup powder, plum jam and orange-strawberry juice. Quantitative analysis was performed without the use of tedious sample pretreatment, due to the achievement of the second-order advantage. The results obtained showed an improvement in simplicity, speed and cost with respect to usual separation techniques, allowing to properly quantifying these dyes obtaining limits of detection below 0.

Excitation-emission fluorescence-kinetic data obtained by Fenton degradation. Determination of heavy-polycyclic aromatic hydrocarbons by four-way parallel factor analysis.

For the first time, a simple and environmentally friendly third-order/four-way calibration was applied for the simultaneous determination of five heavy-polycyclic aromatic hydrocarbons (PAHs) in interfering environments. The kinetic evolution of the Fenton degradation of benzo[a]pyrene, dibenz[a,h]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene and benz[a]anthracene was followed by recording full excitation-emission fluorescence matrices (EEFMs) of the samples at different reaction times, obtaining third-order EEFM-kinetic (EEFM-K) data. The sensitivity of the method was increased by carrying out the reaction in the presence of methyl-β-cyclodextrin.

Therapeutic alternatives for the treatment of type 1 hepatorenal syndrome: A Delphi technique-based consensus.

Aim: To propose several alternatives treatment of type 1 hepatorenal syndrome (HRS-1) what is the most severe expression of circulatory dysfunction on patients with portal hypertension.

Methods: A group of eleven gastroenterologists and nephrologists performed a structured analysis of available literature. Each expert was designated to review and answer a question.

Enantiomeric analysis of overlapped chromatographic profiles in the presence of interferences. Determination of ibuprofen in a pharmaceutical formulation containing homatropine.

In this work, we studied the combination of chemometric methods with chromatographic separations as a strategy applied to the analysis of enantiomers when complete enantioseparation is difficult or requires long analysis times and, in addition, the target signals have interference from the matrix. We present the determination of ibuprofen enantiomers in pharmaceutical formulations containing homatropine as interference by chiral HPLC-DAD detection in combination with partial least-squares algorithms. The method has been applied to samples containing enantiomeric ratios from 95:5 to 99.

[Grupo Colaborativo de Resistencia Bacteriana, Chile: recommendations 2014 towards the control of bacteria resistance].

Five issues were reviewed in depth at the 2014 annual meeting of Colaborative Group Against Bacterial Resistance and the antecedents and conclusions are detailed in this document. I.- News in CLSI 2014: the difficulties and implications on its implementation at the local level were reviewed and recommendations were set.

Scope of partial least-squares regression applied to the enantiomeric composition determination of ketoprofen from strongly overlapped chromatographic profiles.

Valuable quantitative information could be obtained from strongly overlapped chromatographic profiles of two enantiomers by using proper chemometric methods. Complete separation profiles where the peaks are fully resolved are difficult to achieve in chiral separation methods, and this becomes a particularly severe problem in case that the analyst needs to measure the chiral purity, i.e.

Management of nonalcoholic fatty liver disease: an evidence-based clinical practice review.

Aim: To build a consensus among Chilean specialists on the appropriate management of patients with nonalcoholic fatty liver disease (NAFLD) in clinical practice.

Methods: NAFLD has now reached epidemic proportions worldwide. The optimal treatment for NAFLD has not been established due to a lack of evidence-based recommendations.

Recent applications of first- and second-order multivariate calibration to analytical chemistry.

This report reviews recent literature on the application of multivariate calibration techniques to both first- and second-order data, aimed at the analytical determination of analytes of interest or sample properties in a variety of industrial, pharmaceutical, food, and environmental samples, including examples of process control. The most used data processing tools are briefly described, with emphasis on the advantages that can be obtained by applying specific combinations of multivariate data and algorithms. The main focus is on works devoted to first-order data (i.

Determination of five pesticides in juice, fruit and vegetable samples by means of liquid chromatography combined with multivariate curve resolution.

The aim of this work was to quantify five commonly used pesticides (propoxur, carbaryl, carbendazim, thiabendazole and fuberidazole) in real samples as: tomato, orange juice, grapefruit juice, lemon and tangerine. The method used for the determination of these analytes in the complex matrices was high-performance liquid chromatography with diode array detection. In order to work under isocratic conditions and to complete each run in less than 10 min, the analysis was carried out applying multivariate curve resolution coupled to alternating least-squares (MCR-ALS).

Envelope analysis of the airflow signal to improve polysomnographic assessment of sleep disordered breathing.

Study Objectives: Given the detailed respiratory waveform signal provided by the nasal cannula in polysomnographic (PSG) studies, to quantify sleep breathing disturbances by extracting a continuous variable based on the coefficient of variation of the envelope of that signal.

Design: Application of an algorithm for envelope analysis to standard nasal cannula signal from actual polysomnographic studies.

Setting: PSG recordings from a sleep disorders center were analyzed by an algorithm developed on the Igor scientific data analysis software.