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1.
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1560345

ABSTRACT

La cirugía de remodelación o reducción de la base alar, también conocida como aloplastía o alotomía, es un procedimiento orientado a modificar el ancho, la forma de las narinas y la base de la nariz. El objetivo de esta revisión es describir las indicaciones generales de una alotomía, sus consideraciones anatómicas y las técnicas quirúrgicas más frecuentemente utilizadas.


Alar base remodeling or reduction surgery, also known as alloplasty or allotomy, is a procedure aimed at modifying the width and shape of the nostrils and the base of the nose. The objective of this review is to describe the general indications for an allotomy, its anatomical considerations, and the most frequently used surgical techniques.

2.
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1560347

ABSTRACT

Introducción: El mareo postural perceptual persistente (MPPP) es una de las causas más frecuentes de vértigo crónico. Si bien, los pacientes con MPPP tienen alteraciones de la percepción espacial, se desconoce si presentan alteraciones en el miedo a las alturas. Para no exponer a pacientes con MPPP a ambientes reales con altura, nos propusimos utilizar la realidad virtual para estudiar el miedo a las alturas. Objetivo: Cuantificar el miedo a las alturas en pacientes con MPPP y controles mediante ambientes simulados con realidad virtual. Material y Método: Estudio transversal, prospectivo de casos y controles pareados por edad y sexo. Se reclutaron pacientes con MPPP del Servicio de Otorrinolaringología del Hospital Clínico de la Universidad de Chile entre los años 2020 y 2021. Se midió presencia subjetiva de miedo y taquicardia. Los escenarios se desarrollaron con el programa Blender 2.8 y Oculus Link para equipo Oculus Quest. Se utilizaron cinco escenarios a diferentes alturas (pisos 1, 3, 6, 12, 19). Resultados: Se reclutaron 20 sujetos (12 mujeres, 47 años en promedio), incluyendo 10 pacientes con MPPP y 10 controles sin síntomas vestibulares. Ningún sujeto del grupo control presentó miedo en los escenarios presentados, mientras que siete pacientes del grupo MPPP tuvieron miedo subjetivo a una altura menor a 40 metros virtuales (Fischer, p < 0,05). Conclusión: Los pacientes con MPPP presentan, con mayor frecuencia, miedo subjetivo a las alturas que los controles, pero se requiere de nuevos estudios para determinar si este miedo es específico de MPPP, o es general a otras causas de vértigo crónico.


Introduction: Persistent Postural Perceptual Dizziness (PPPD) is one of the most common causes of chronic vertigo. While patients with PPPD have spatial perception alterations, it is unknown whether they present alterations in fear of heights. To avoid exposing patients with PPPD to high places, we aimed to use virtual reality to quantify fear of heights. Aim: To quantify fear of heights in patients with PPPD and controls using simulated environments with virtual reality. Material and Method: A prospective cross-sectional study of age- and sex-matched case-control pairs. PPPD patients were recruited from the Otolaryngology Service of the Clinical Hospital of the University of Chile between 2020 and 2021. Presence of subjective fear and tachycardia were measured. The scenarios were developed using Blender 2.8 and Oculus Link for the Oculus Quest. Five scenarios at different heights (floors 1, 3, 6, 12, 19) were used. Results: Twenty subjects were recruited (12 women, average age of 47 years), including 10 PPPD patients and 10 controls without vestibular symptoms. None of the control group subjects presented fear in the presented scenarios, while seven patients in the PPPD group had subjective fear at a height lower than virtual 40 meters (Fischer, p < 0.05). Conclusion: Patients with PPPD present a greater proportion of subjective fear to heights than controls, but further studies are required to determine if this fear is specific to PPPD or is general to other causes of chronic vertigo.

3.
Anal Chim Acta ; 1223: 340196, 2022 Aug 29.
Article in English | MEDLINE | ID: mdl-35999003

ABSTRACT

The standard method for estimating the chemical oxygen demand (COD) of water bodies uses dichromate as the main oxidant, a chemical agent whose use has been restricted in the European Union since 2017. This method is hazardous, time-consuming, and burdensome to adapt to on-site measurements. As an alternative and following the current trends of sustainable and green chemistry, a method using the less toxic reagent sodium persulfate as the oxidizing agent has been developed. In this method an excess of persulfate, activated through heating in an alkaline solution, oxidizes the chemically degradable organic fraction through a 2-step radical mechanism. The remaining persulfate is evaluated by chemiluminescence (CL) using luminol and a portable charge-coupled device (CCD) camera. The method provided quantitative recoveries and a sample throughput of >60 samples h-1. It was validated in river water samples by comparison of COD estimations with the standard dichromate method (R = 0.973, p < 0.05) and with a UV-Vis permanganate-based method (R = 0.9998, p < 0.05), the latter being also used for drinking waters. The proposed method is a sustainable and green alternative to the previous used methods. Overall, the method using activated persulfate is suitable for use as COD quantitation/screening tool in surface waters. Considering that its main components are portable, it can be ultimately adapted for in situ analysis at the point of need.


Subject(s)
Fresh Water , Luminol , Biological Oxygen Demand Analysis , Fresh Water/analysis , Oxidation-Reduction , Oxygen/analysis , Water/analysis
4.
Rev Gastroenterol Mex (Engl Ed) ; 87(3): 297-304, 2022.
Article in English | MEDLINE | ID: mdl-34794928

ABSTRACT

INTRODUCTION AND AIMS: Colonoscopy quality is measured by the degree in which the examination increases the likelihood of obtaining adequate results on health. Our aim was to develop an instrument for evaluating the quality of screening colonoscopies, taking into account the performance of endoscopists and endoscopy units. MATERIALS AND METHODS: Mixed methodology was employed. The first stage (qualitative) consisted of a Medline search, from which a group of experts developed the quality score items. The second stage (quantitative) utilized a modified Delphi technique to reach consensus (3 rounds). We evaluated the psychometric properties of the instrument (reliability and construct validity) in elective screening colonoscopies (in patients ≥ 50 years of age), performed within the January-April 2017 time frame. RESULTS: A final instrument with 8 items was produced: (1) the Boston Bowel Preparation Scale score; (2) cecal intubation rate; (3) colonoscopy withdrawal time; (4) image documentation; (5) adenoma detection rate; (6) endoscopic surveillance planning; (7) perforation rate, and (8) continuous improvement programs. The instrument was evaluated in 323 colonoscopies performed by 31 endoscopists and found to be one-dimensional and reliable (Cronbach's alpha 0.76). Performance was compared between endoscopists (center 1) and an expert endoscopist from another center (center 2): Boston Bowel Preparation Scale score 8.3 vs. 7.36 (P < .001), cecal intubation rate 93.5 vs. 96%, colonoscopy withdrawal time 14.8 vs. 8.4 min (P < .001), and adenoma detection rate 34 vs. 52.2% (P < .001), respectively. CONCLUSION: The Colonoscopy Quality Score is a reliable and valid instrument for evaluating screening colonoscopy quality. Its results could be adapted to the usual endoscopic report to adjust monitorization frequency post-colonoscopy.


Subject(s)
Adenoma , Colorectal Neoplasms , Adenoma/diagnosis , Cecum , Colonoscopy/methods , Colorectal Neoplasms/diagnosis , Humans , Psychometrics , Reproducibility of Results
5.
Article in English, Spanish | MEDLINE | ID: mdl-34312017

ABSTRACT

INTRODUCTION AND AIMS: Colonoscopy quality is measured by the degree in which the examination increases the likelihood of obtaining adequate results on health. Our aim was to develop an instrument for evaluating the quality of screening colonoscopies, taking into account the performance of endoscopists and endoscopy units. MATERIALS AND METHODS: Mixed methodology was employed. The first stage (qualitative) consisted of a Medline search, from which a group of experts developed the quality score items. The second stage (quantitative) utilized a modified Delphi technique to reach consensus (3 rounds). We evaluated the psychometric properties of the instrument (reliability and construct validity) in elective screening colonoscopies (in patients≥50 years of age), performed within the January-April 2017 time frame. RESULTS: A final instrument with 8 items was produced: 1) the Boston Bowel Preparation Scale score; 2) cecal intubation rate; 3) colonoscopy withdrawal time; 4) image documentation; 5) adenoma detection rate; 6) endoscopic surveillance planning; 7) perforation rate, and 8) continuous improvement programs. The instrument was evaluated in 323 colonoscopies performed by 31 endoscopists and found to be one-dimensional and reliable (Cronbach's alpha 0.76). Performance was compared between endoscopists (center 1) and an expert endoscopist from another center (center 2): Boston Bowel Preparation Scale score 8.3 vs. 7.36 (P<.001), cecal intubation rate 93.5 vs. 96%, colonoscopy withdrawal time 14.8 vs. 8.4min (P<.001), and adenoma detection rate 34 vs. 52.2% (P<.001), respectively. CONCLUSION: The Colonoscopy Quality Score is a reliable and valid instrument for evaluating screening colonoscopy quality. Its results could be adapted to the usual endoscopic report to adjust monitorization frequency post-colonoscopy.

6.
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1389732

ABSTRACT

Resumen La enfermedad de Ménière (EM) es una conocida causa de vértigo crónico asociado a múltiples síntomas audiológicos fluctuantes (hipoacusia, tinnitus, plenitud aural). Su fisiopatología no es completamente comprendida, pero se ha relacionado al hidrops endolinfático (HE) como entidad principal. A la fecha, varios estudios electrofisiológicos han intentado posicionarse como pruebas diagnósticas definitivas, pero no lo han logrado, ya sea por dificultad técnica para realizarlos o por resultados inconsistentes en la literatura internacional. Pero cabe destacar que varios hallazgos son altamente sugerentes de enfermedad de Ménière como la presencia de una baja tasa de respuesta asociado al aumento del umbral de esta misma en los VEMPs (vestibular evoked myogenic potentials), tanto oculares como cervicales, o el aumento del cuociente entre el potencial de sumación/potencial de acción en la electrococleografía. A pesar de estas pruebas, hasta el día de hoy, el diagnóstico se sigue realizando en base a criterios clínicos consensuados internacionalmente, dado lo dificultosa que es la visualización directa del HE y falta de compresión de otros mecanismos fisiopatológicos de esta enfermedad. En las últimas décadas, ha habido avances prometedores en la detección de hidrops endolinfático con el uso de resonancia magnética, permitiendo la visualización de los espacios peri y endolinfáticos usando gadolinio como contraste. A su vez, esto ha permitido mejoría de las secuencias imagenológicas usadas, el desarrollo de varias nuevas técnicas de procesamiento de imágenes, conllevando que varias escalas o clasificaciones de HE hayan sido propuestas, las cuales serán revisadas en detalle en este trabajo.


Abstract Ménière's disease (MD) is a known cause of chronic vertigo, with multiple fluctuating audiological symptoms (hearing loss, tinnitus, aural fullness). The pathophysiology is not completely understood but has been attributed to endolymphatic hydrops (EH). There are many electrophysiological tests available, but none of them can be considered as the gold standard, either because of difficult technique or inconsistent results in the literature. Nonetheless, some findings are highly suggestive of MD, like the presence of a low response and high threshold in ocular and cervical VEMPs (vestibular evoked myogenic potentials), or the increased ratio between the amplitudes of summation potential and action potential in the electrocochleography. Despite the availability of these tests, the diagnosis of MD is still made clinically, following the diagnostic criteria establish by international consensus, due to the difficulty to visualize the EH and also the lack of full comprehension of other pathophysiological mechanisms. In the last decades, there have been promising advances in the detection of endolymphatic hydrops with magnetic resonance imaging, allowing the visualization of the perilymphatic and endolymphatic space using gadolinium as a contrast agent. At the same time, the imaging sequences have improved, new techniques for imaging processing have been developed, entailing that various classifications or graduation systems for EH have been proposed, which will be review in detail, in this paper.

7.
Mar Pollut Bull ; 142: 206-215, 2019 May.
Article in English | MEDLINE | ID: mdl-31232296

ABSTRACT

Sampling, cost-effective analysis, diagnosis of sources of pollution and assessment of potential toxicological effects were included in the case study. Marine sediments collected from 24 points along the eastern Mediterranean coast of Spain (Comunitat Valenciana region) in 2010, 2011, 2012 and 2015 have been analysed for polycyclic aromatic hydrocarbons. Fluoranthene, pyrene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene were the most found. An analysis of the relative abundance of selected PAHs revealed that petrogenic and mixed petrogenic/pyrogenic sources are predominant in the area. The total concentrations of the target compounds ranged from 14.7 to 615.3 ng/g dry weight. The effects range-low (ERL) guideline values were used to assess potential toxicological effects. Rarely adverse biological effects can be expected in the tested area. The level of pollution by PAHs in the area can be considered low, although occasionally high values can be found, particularly in areas with high population or ship traffic.


Subject(s)
Geologic Sediments/analysis , Polycyclic Aromatic Hydrocarbons/analysis , Water Pollutants, Chemical/analysis , Environmental Monitoring , Spain
8.
Anal Chim Acta ; 1045: 23-41, 2019 Jan 03.
Article in English | MEDLINE | ID: mdl-30454572

ABSTRACT

This tutorial aims at providing guidelines for analyzing metallic nanoparticles (NPs) and their dispersions by using methods based on miniaturized liquid chromatography with diode array detection (MinLC-DAD) and coupled on-line to in-tube solid-phase microextraction (IT-SPME). Some practical advice and considerations are given for obtaining reliable results. In addition, this work outlines the potential applications that set these methodologies apart from microscopy-related techniques, dynamic light scattering, single particle ICP-MS, capillary electrophoresis, field-flow fractionation and other chromatographic configurations, which are discussed and mainly seek to accomplish size estimation and NP separation, speciation analysis and quantification of mainly AgNPs and AuNPs. MinLC-DAD has the potential to estimate the NP concentration and from it the average size of unknown samples by calibrating with a single standard, as well as studying potentially non-spherical particles and stability-related properties of their dispersions. While keeping the signal dependency with concentration and increasing the method sensitivity, IT-SPME-MinLC-DAD goes further allowing for the assessment of the dispersant effect and ultimately changes in the nanoparticle surroundings that range from modifications of the hydrodynamic diameter to the exposure to different reagents and matrices. The methodology can still be improved by either exploring newer IT-SPME adsorbents or by assaying new system configurations. Taking into account that this technique gives complementary information in relation to other techniques discussed here, this tutorial serves as a guide for analyzing metallic NPs towards a better understanding of the particle behavior under different scenarios.

9.
Sci Total Environ ; 630: 1226-1236, 2018 Jul 15.
Article in English | MEDLINE | ID: mdl-29554744

ABSTRACT

The capacity of different soils to capture silver nanoparticles (AgNPs) by measuring changes of an AgNP intrinsic property such as the plasmon for the first time, was studied. In-tube solid-phase microextraction (IT-SPME) coupled on-line to capillary liquid chromatography (CapLC) with diode array detection (DAD) was employed for measuring the interactions between soil and in-contact AgNP dispersions. Its achieved LOD 9 pM assures quantitative retention measurements and selectivity for soil lixiviation was suitable. Electronic microscopy was employed for corroborating the entrapped Ag into the soils. Capture % of AgNPs was calculated in compost (>99%), mountain (>99%), orchard (15±1%) and urban (48±1%) soils. Also, the relation between some soil characteristics: solid organic matter (SOM), composition, pH, redox potential (Eh), electrical conductivity (EC) and size, and the retention of these metallic nanoparticles was studied. The results have also been estimated after sieving and the capture % of AgNPs was similar in the resulting fractions. AgNP adsorption on a given soil is mainly affected by its organic matter content for studied soils with higher SOM amounts (23-62%). However, for the soils with lower SOM amounts (4.6-8.3%) the role of HAs could prevent AgNP deposition onto soils. The proposed methodology can be utilized for quickly assessing the potential of a given soil considering its properties for capturing these nanoparticles, which can come at handy for their administration, characterization or remediation.

10.
Rev. chil. cir ; 69(3): 268-272, jun. 2017.
Article in Spanish | LILACS | ID: biblio-844372

ABSTRACT

Introducción: Se estima que del total de los cánceres, el 5-10% tendría una base genética. Actualmente es posible identificar a los individuos con predisposición genética en algunos cánceres como manera de intervenir precozmente en el desarrollo de esta enfermedad. Objetivos: Evaluar la utilidad de la cirugía profiláctica en el cáncer medular de tiroides hereditario. Material y métodos: Este trabajo es una revisión de literatura de diferentes estudios extraídos de bibliotecas electrónicas como Scientific Electronic Library Online (SciELO), MedLine-PubMed y UpToDate, mediante la construcción de preguntas clínicas y términos MeSH enfocados principalmente en la búsqueda específica de información sobre el cáncer medular de tiroides hereditario. Resultados: Los estudios revisados demuestran que la tiroidectomía profiláctica con resección linfática cervical representa el único tratamiento eficaz en el caso del cáncer medular de tiroides hereditario. Conclusiones: La cirugía profiláctica ha demostrado una importante disminución del riesgo de cáncer de tiroides y se considera una conducta de rigor en portadores del gen RET en el cáncer medular de tiroides.


Introduction: Approximately 5-10% of global cancer has a genetic base. Nowadays it is possible to identify those who have a genetic predisposition for some cancers, so they can be treated in short term. Objectives: Evaluate how useful is prophylactic surgery on hereditary Medullary Thyroid Cancer. Materials and methods: This investigation is a literature review of different research papers from electronic databases such as Scientific Electronic Library Online (SciELO), MedLine-PubMed and UpToDate. The research was made with clinical queries and MeSH terms, specially focused on hereditary Medullary Thyroid Cancer. Results: This research shows that prophylactic Thyroidectomy with cervical lymph node resection is the only effective and curative treatment for hereditary Medullary Thyroid Cancer. Conclusions: Prophylactic surgery has proof an important role decreasing the risk on Hereditary Thyroid cancer Syndrome and in RET carriers surgery is considered a must.


Subject(s)
Humans , Carcinoma, Medullary/congenital , Carcinoma, Medullary/surgery , Thyroid Neoplasms/surgery , Thyroidectomy/methods , Carcinoma, Medullary/prevention & control , Prophylactic Surgical Procedures , Thyroid Neoplasms/prevention & control
11.
Rev. chil. cir ; 68(6): 462-466, dic. 2016.
Article in Spanish | LILACS | ID: biblio-830103

ABSTRACT

Introducción: Se estima que del total de los cánceres, el 5-10% tendría una base genética. Actualmente es posible identificar a los individuos con predisposición genética a desarrollar cáncer de mama, una manera de intervenir precozmente en el desarrollo de esta enfermedad. Objetivos: Evaluar la utilidad de la cirugía profiláctica en el síndrome de cáncer hereditario de mama. Material y métodos: Este trabajo es una revisión de literatura de diferentes estudios extraídos de bibliotecas electrónicas como Scientific Electronic Library Online (SciELO), MedLine-PubMed y UpToDate, mediante la construcción de preguntas clínicas y términos MeSH enfocados principalmente en la búsqueda específica de información del síndrome de cáncer hereditario de mama. Resultados: Los estudios revisados demuestran que la mastectomía bilateral profiláctica (MBP) disminuye en un 90% el riesgo de desarrollar cáncer de mama en las mujeres portadoras de BRCA1 o BRCA2. En cuanto a la salpingooferectomía (SO), reduciría entre un 50-56% el riesgo de cáncer de mama dependiendo de la mutación a la que se asocie. Conclusiones: La cirugía profiláctica ha demostrado importante disminución del riesgo de cáncer de mama, por lo que su uso es recomendado al hallazgo de las mutaciones BRCA1 y BRCA2.


Introduction: Approximately 5-10% of global cancer has a genetic base. Nowadays it is possible to identify those who have a genetic predisposition for breast cancer, so they can be treated in short term. Objectives: Evaluate how useful is prophylactic surgery on Hereditary Breast cancer Syndrome. Materials and methods: This investigation is a literature review of different research papers from electronic databases such as Scientific Electronic Library Online (SciELO), MedLine-PubMed and UpToDate. The research was made with clinical queries and MeSH terms, specially focused on Hereditary Breast cancer Syndrome. Results: This research shows that prophylactic bilateral mastectomy (PBM) decreases 90% risk of developing breast cancer in BRCA1 and BRCA2 carriers. On the other hand, Salpyngo-oophoferectomy (SO) technique decreases around 53% chances of breast cancer, depending on the associated mutation. Conclusion: Prophylactic surgery has shown an important role decreasing the risk on Hereditary Breast cancer Syndrome. So on, in cases of BRCA1 and BRCA2 carriers we suggest to perform prophylactic surgery.


Subject(s)
Humans , Female , Breast Neoplasms/genetics , Breast Neoplasms/prevention & control , Breast Neoplasms/surgery , Genetic Predisposition to Disease , Prophylactic Surgical Procedures/methods
12.
J Chromatogr A ; 1432: 17-25, 2016 Feb 05.
Article in English | MEDLINE | ID: mdl-26795277

ABSTRACT

Following the present trends in miniaturization, a methodology that combines on-line In-Tube Solid-Phase Microextraction (IT-SPME) with Liquid Nanochromatography (nano-LC) and UV-vis diode array detection (DAD) was developed. This coupling was achieved by using two interconnected valves (i.e. conventional and micro-automatic valves) in the system of injection. As for IT-SPME, different materials, containing in some cases nanostructures or nanoparticles and in other cases polymeric adsorbent phases immobilized on capillary columns, were tested in order to improve extraction efficiencies of organic compounds; diclofenac was selected as the target analyte. Additionally, the transfer time of the sample between the two injection valves, as well as the lengths and the internal diameters of the capillary columns, was optimized. Under the selected conditions, the resulting IT-SPME-nano-LC-DAD method showed great potential to become a powerful analytical tool as it was successfully applied to the determination of diclofenac in pharmaceutical and water samples. For comparison purposes, IT-SPME coupled to Capillary Liquid Chromatography (Cap-LC) was used. The extraction yield of diclofenac reached near 80%, a high value for techniques that involve IT-SPME. Good accuracy (recoveries near 100%) and precision (4% RSD) were obtained.


Subject(s)
Chromatography, Liquid/methods , Nanostructures , Solid Phase Microextraction/instrumentation , Adsorption , Solid Phase Microextraction/methods
13.
Anal Bioanal Chem ; 406(8): 2211-5, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24105458

ABSTRACT

This work demonstrates the application of silica supported Fe3O4 nanoparticles as sorbent phase for magnetic solid-phase extraction (MSPE) and magnetic on-line in-tube solid-phase microextraction (Magnetic-IT-SPME) combined with capillary liquid chromatography-diode array detection (CapLC-DAD) to determine organophosphorous compounds (OPs) at trace level. In MSPE, magnetism is used as separation tool while in Magnetic-IT-SPME, the application of an external magnetic field gave rise to a significant improvement of the adsorption of OPs on the sorbent phase. Extraction efficiency, analysis time, reproducibility and sensitivity have been compared. This work showed that Magnetic-IT-SPME can be extended to OPs with successful results in terms of simplicity, speed, extraction efficiency and limit of detection. Finally, wastewater samples were analysed to determine OPs at nanograms per litre.


Subject(s)
Organophosphorus Compounds/chemistry , Silicon Dioxide/chemistry , Solid Phase Extraction/methods , Solid Phase Microextraction/methods , Water Pollutants, Chemical/chemistry , Magnetite Nanoparticles , Organophosphorus Compounds/isolation & purification , Solid Phase Extraction/instrumentation , Solid Phase Microextraction/instrumentation , Wastewater/chemistry , Water Pollutants, Chemical/isolation & purification
14.
Nanomaterials (Basel) ; 4(2): 242-255, 2014 Apr 02.
Article in English | MEDLINE | ID: mdl-28344221

ABSTRACT

The use of magnetic nanomaterials for analytical applications has increased in the recent years. In particular, magnetic nanomaterials have shown great potential as adsorbent phase in several extraction procedures due to the significant advantages over the conventional methods. In the present work, the influence of magnetic forces over the extraction efficiency of triazines using superparamagnetic silica nanoparticles (NPs) in magnetic in tube solid phase microextraction (Magnetic-IT-SPME) coupled to CapLC has been evaluated. Atrazine, terbutylazine and simazine has been selected as target analytes. The superparamagnetic silica nanomaterial (SiO2-Fe3O4) deposited onto the surface of a capillary column gave rise to a magnetic extraction phase for IT-SPME that provided a enhancemment of the extraction efficiency for triazines. This improvement is based on two phenomena, the superparamegnetic behavior of Fe3O4 NPs and the diamagnetic repulsions that take place in a microfluidic device such a capillary column. A systematic study of analytes adsorption and desorption was conducted as function of the magnetic field and the relationship with triazines magnetic susceptibility. The positive influence of magnetism on the extraction procedure was demonstrated. The analytical characteristics of the optimized procedure were established and the method was applied to the determination of the target analytes in water samples with satisfactory results. When coupling Magnetic-IT-SPME with CapLC, improved adsorption efficiencies (60%-63%) were achieved compared with conventional adsorption materials (0.8%-3%).

15.
Anal Chem ; 85(21): 10013-6, 2013 Nov 05.
Article in English | MEDLINE | ID: mdl-24131247

ABSTRACT

Silver ions (Ag(+)) can be quantified in situ in the presence of AgNPs by using a colorimetric sensing probe (3,3',5,5'-tetramethylbenzidine). Interestingly, it also enables detection of the Ag(+) adsorbed on the AgNP surface. This is relevant to design new methods to make AgNPs while ensuring the total reduction of Ag(+).

16.
J Chromatogr A ; 1263: 43-50, 2012 Nov 09.
Article in English | MEDLINE | ID: mdl-23040974

ABSTRACT

This study shows that ultrasonic assisted extraction is a good practise for removing impurities from sorbents used for matrix-solid phase dispersion (MSPD). A previous washing of the sorbent with an organic solvent or mixture of solvents eliminates part of the interferences, but this treatment is not enough for the quantification of PAHs at ng/g levels. It is demonstrated that the determination of traces of polycyclic aromatic hydrocarbons (PAHs) in solid samples processed by matrix-solid phase dispersion (MSPD) may be severely affected by the presence of sorbent impurities. Different extraction solvents and sonication conditions have been tested, and on the basis of the results obtained a new approach is presented for cleaning sorbents typically used in MSPD such C(18), silica or Florisil. The utility of the described approach has been illustrated by analysing by liquid chromatography and fluorescence detection different marine sediments.


Subject(s)
Geologic Sediments/chemistry , Polycyclic Compounds/analysis , Seawater/chemistry , Ultrasonics , Water Pollutants, Chemical/analysis , Adsorption
17.
Arch Latinoam Nutr ; 45(1): 63-6, 1995 Mar.
Article in Spanish | MEDLINE | ID: mdl-8729255

ABSTRACT

An instant dessert powder, pudding type was developed to be consumed at lunch or dinner time. The dessert was designed to be prepared in skim milk and meets the nutritional needs of elderly people. The dessert contains modified starch, carragenine, vegetal fat, sacharose. Each serving has been enriched with 30% of the daily vitamin requirement advised for adults over 51 years old. The optimized process was carried out according to the Karlsruhe test. Each serving consists of 22g powder prepared in proportion of 18% in skim milk. The optimized dessert powder was controlled by means of physical, chemical and microbiological analyses. The sensory quality was determined in the ready to eat product and the acceptability level was measured in a group of people selected according to the characteristics of the target population. The dessert powder contains 1.1% protein, 5.2% fats, 89.76% carbohidrates, and provides 409 Kcal/100g. Both the sensory and microbiological quality were good and the level of acceptance reached 98%.


Subject(s)
Diet , Food, Fortified/analysis , Nutritional Requirements , Vitamins/administration & dosage , Aged , Humans , Nutritive Value
18.
Horiz. enferm ; 6(1): 42-5, mar. 1995.
Article in Spanish | LILACS, BDENF - Nursing | ID: lil-172932

ABSTRACT

El artículo que se presenta a continuación describe el Programa de Mejoramiento de la Calidad de Atención que se implementará en el Hospital Clínico de la Pontificia Universidad Católica de Chile; a partir del presente año. Se destaca en este programa la aplicación de metodologías utilizadas en Europa, especialmente en España como son: el modelo europeo de calidad Iso 9000; y los Métodos Serqual y de Pactos


Subject(s)
Humans , Total Quality Management/methods , Quality of Health Care , Strategic Planning
19.
Arch. latinoam. nutr ; 45(1): 63-6, mar. 1995. tab
Article in Spanish | LILACS | ID: lil-234674

ABSTRACT

Se desarrolló un postre instantáneo en polvo, que al ser reconstituído en la leche descremada, permitió obtener un postre tipo budín, el cual está destinado al módulo almuerzo-cena de los adultos mayores. El producto en polvo está elaborado a partir de sacarosa, almidón modificado, grasa vegetal y carragenina; además, cada porción está enriquecida con un 30 por ciento del requerimiento diario de vitaminas recomendado para adultos mayores de 51 años. El postre fue optimizado a través del análisis sensorial con el Test de valoración de calidad por parámetros de Karlshe. La porción indivisual de budín quedó constituída por 22 gramos de polvo reconstituídos al 18 por ciento en leche descremada. El producto en polvo optimizado fue evaluado a través de análisis físicos, químicos y microbiológicos; además, se estudió la calidad sensorial del postre y su aceptabilidad en personas que pertenecen a este grupo etáreo. Se encontró un aporte de 1.1 por ciento de proteínas, 5.2 por ciento de lípidos y 89 por ciento de carbohidratos en el producto en polvo, con un valor calórico correspondiente a 409 Kcal/100g. Tanto la calidad microbiológica como sensorial fue excelente y obtuvo una aceptación del 98 por ciento


Subject(s)
Humans , Male , Female , Pregnancy , Adolescent , Adult , Food Microbiology , Lipids/administration & dosage , Milk/classification , Sucrose/administration & dosage , Vitamins/administration & dosage
20.
Rev Chil Obstet Ginecol ; 60(1): 6-10; discussion 10-1, 1995.
Article in Spanish | MEDLINE | ID: mdl-8525039

ABSTRACT

The objective of our study was prospectively compare the effect in the rate of cesarean section of active labor management and of traditional labor management in primiparas with physiological term pregnancy. From september 1, 1993 to may 31, 1994, 145 primiparas with physiological term pregnancy were randomly assigned to one group of active labor management (study group, n = 75) and to one group of traditional labor management (control group, n = 70). Cesarean section rate was 9.3% in the study group and 20% in the control group (p < 0.05). There was no increase in fetal morbidity or mortality. Active labor management can reduce cesarean section rate in primiparas with physiological term pregnancy.


Subject(s)
Cesarean Section , Labor, Obstetric , Parity , Adult , Amnion/surgery , Dystocia/therapy , Female , Fetal Monitoring , Humans , Labor, Induced , Natural Childbirth , Pregnancy , Prospective Studies
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