Photon-Counting Detector CT: Key Points Radiologists Should Know

Esquivel Andrea,Ferrero Andrea,Mileto Achille,Baffour Francis,Horst Kelly,Rajiah Prabhakar Shantha,Inoue Akitoshi,Leng Shuai,McCollough Cynthia,Fletcher Joel G. 대한영상의학회 2022 Korean Journal of Radiology Vol.23 No.9

Photon-counting detector (PCD) CT is a new CT technology utilizing a direct conversion X-ray detector, where incident X-ray photon energies are directly recorded as electronical signals. The design of the photon-counting detector itself facilitates improvements in spatial resolution (via smaller detector pixel design) and iodine signal (via count weighting) while still permitting multi-energy imaging. PCD-CT can eliminate electronic noise and reduce artifacts due to the use of energy thresholds. Improved dose efficiency is important for low dose CT and pediatric imaging. The ultra-high spatial resolution of PCD-CT design permits lower dose scanning for all body regions and is particularly helpful in identifying important imaging findings in thoracic and musculoskeletal CT. Improved iodine signal may be helpful for low contrast tasks in abdominal imaging. Virtual monoenergetic images and material classification will assist with numerous diagnostic tasks in abdominal, musculoskeletal, and cardiovascular imaging. Dual-source PCD-CT permits multi-energy CT images of the heart and coronary arteries at high temporal resolution. In this special review article, we review the clinical benefits of this technology across a wide variety of radiological subspecialties.

Statistics of velocity centroids: effects of density–velocity correlations and non-Gaussianity

Esquivel, A.,Lazarian, A.,Horibe, S.,Cho, J.,Ossenkopf, V.,Stutzki, J. Blackwell Publishing Ltd 2007 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.381 No.4

<P>ABSTRACT</P><P>We continue with our previous work on statistics of velocity centroids, to retrieve information about the scaling properties of an underlying turbulent velocity field from spectroscopic observations. We use synthetic data sets with extreme effects of velocity–density correlations that we create artificially, which also have a non-Gaussian distribution of fluctuations. We confirm that centroids can be used to obtain the scaling properties of the turbulent velocity when the ratio of the density dispersion to the mean density is less than unity, regardless of velocity–density correlations and non-Gaussianity. It was found that extreme velocity–density correlations can distort the statistics of velocity centroids, impeding the recovery of the turbulent velocity spectral index from centroids. We show that such correlations introduce high-order moments to the maps of centroids, which we disregarded in previous work, but that they are only important when the density dispersion is large in comparison with the mean density. It was also found that non-Gaussian velocity and/or density distort the statistics of centroids too, but to a lower degree than extreme cross-correlations.</P>

Characterization of aged male BALB/ccenp mice as a model of dementia

Nashelly Esquivel,Yenela García,Bestraida Lores,Marivy Gutiérrez,Claudio Rodríguez 한국실험동물학회 2020 Laboratory Animal Research Vol.36 No.1

Dementia is defined as cognitive impairment in more than one cognitive area and leads to an abnormal degree of impairment in the ability to remember past events. Among mice models of dementia the most used strains are SAMP8 and C57BL/6. There is no reference to characterizing a model of dementia in naturally aged mice of the BALB/c strain, or to the minimum age at which these animals can be used. The aim of this study was the characterization of aged male BALB/ccenp mice as a model of dementia from the evaluation of behavioural, pathological and biochemical markers. One hundred and twenty mice were used and 10 of these were analysed from 8 to 9 months of age, and every 4 months, in a comparative way to young control animals from 4 to 5 months. At the age of 12–13 months there was cognitive impairment in the animals from the Y-maze and object recognition tests and this impairment was maintained at 16–17 months of age. An increase in oxidative damage to proteins in the brains of aged animals was also found in relation to young animals; as well as a decrease in the concentration of triglycerides. At the age of 16–17 months, a significant decrease in the size of the thymus and brain was obtained. We consider that it’s a very useful option to use animals 12–13 months of age where there are symptoms of cognitive deficiency, histopathological and biochemical elements characteristic of dementia.

Trabajo Precario y Vulnerabilidad Social de las Mujeres en la Periferia de la Zona Metropolitana de Guadalajara, México

Rangel Esquivel Jose Manuel,Villanueva Perez Nancy 부산외국어대학교 중남미지역원 2011 이베로아메리카 Vol.13 No.2

This study is derived from qualitative research during the period 2007-2009 in an urban marginalized sector at the periphery of the Guadalajara Metropolitan Area (GMA). The poverty conditions for women and their households make the work one of the main resources to confront and cover the most basic needs. The impact of global processes of crisis and economic restructuration, as well as labor flexibility trends over the operation of labor markets (Garcia y Oliveira 1994, 1998; Oliveira y Ariza 1998, 2000, 2001) have been highlighted in its precariousness, situations that have affected the conditions of work for women. From a multidimensional perspective, it is analyzed the diverse types and forms of precarious work for women, as well as the social vulnerability in which they inhabit; this framework proposed by Caroline(1996) allows to visualize the three levels in which it increases or decreases when the units of analysis are based on the individual, the household and the community. The leads to a holistic comprehension of the scenarios in which vulnerability acquires relevant overtones in order to deepen on the different dynamics and processes in which feminine work is immerse. In this sense, with an approximation of the social actors situated in this precarious stage, it is considered from the standpoint of Rocio(2003, 150), that “the study of subjectivity cannot be ignored when seeking to understand changing and dynamic processes of the phenomena of social vulnerability and the roll that plays the access of work in the struggle for survival”. Hence that the deep interviews with a biographical approach realized to women of urban sector contribute to the construction of the meanings the practices around feminine work.

Pectin from Passion Fruit Fiber and Its Modification by Pectinmethylesterase

Contreras-Esquivel, Juan Carlos,Aguilar, Cristobal N.,Montanez, Julio C.,Brandelli, Adriano,Espinoza-Perez, Judith D.,Renard, Catherine M.G.C. The Korean Society of Food Science and Nutrition 2010 Preventive Nutrition and Food Science Vol.15 No.1

Passion fruit fiber pectin gels represent a new alternative pectin source with potential for food and non-food applications on a commercial scale. Pectic polysaccharides were extracted from passion fruit (Passiflora edulis) fiber using citric acid as a clean catalyst and autoclaved for 20 to 60 min at $121^{\circ}C$. The best condition of pectin yield with the highest molecular weight was obtained with 1.0% of citric acid (250 mg/g dry passion fruit fiber pectin) for 20 min of autoclaving. Spectroscopic analyses by Fourier transform infrared, enzymatic degradation reactions, and ion-exchange chromatography assays showed that passion fruit pectin extracted for 20 min was homogeneous high methoxylated pectin (70%). Gel permeation analysis confirmed that the pectin extract obtained by autoclaving by 20 min showed higher molecular weights than those autoclaved for 40 and 60 min. Passion fruit pectin extracted for 20 min was enzymatically modified with fungal pectinmethylesterase to create restructured gels. Short autoclave treatment (20 min) with citric acid as extractant resulted in a significant increase of gel strength, improving pectin extraction in terms of functionality. The treatment of solubilized material (pectic polysaccharides) in the presence of insoluble material (cellulose and hemicellulose) with pectinmethylesterase and calcium led to the creation of a stiffer passion fruit fiber pectin gel, while syneresis was not observed.

Enzymatic Extraction of Lemon Pectin by Endo-Polygalacturonase from Aspergillus niger

Juan C. Contreras-Esquivel,Claudio E. Voget,Carolina E. Vita,J.D. Espinoza-Perez,Catherine M.G.C. Renard 한국식품과학회 2006 Food Science and Biotechnology Vol.15 No.2

Pectin from Passion Fruit Fiber and Its Modification by Pectinmethylesterase

Juan Carlos Contreras-Esquivel,Cristobal N. Aguilar,Julio C. Montanez,Adriano Brandelli,Judith D. Espinoza-Perez,Catherine M.G.C. Renard 한국식품영양과학회 2010 Preventive Nutrition and Food Science Vol.15 No.1

Passion fruit fiber pectin gels represent a new alternative pectin source with potential for food and non-food applications on a commercial scale. Pectic polysaccharides were extracted from passion fruit (Passiflora edulis) fiber using citric acid as a clean catalyst and autoclaved for 20 to 60 min at 121℃. The best condition of pectin yield with the highest molecular weight was obtained with 1.0% of citric acid (250 ㎎/g dry passion fruit fiber pectin) for 20 min of autoclaving. Spectroscopic analyses by Fourier transform infrared, enzymatic degradation reactions, and ion-exchange chromatography assays showed that passion fruit pectin extracted for 20 min was homogeneous high methoxylated pectin (70%). Gel permeation analysis confirmed that the pectin extract obtained by autoclaving by 20 min showed higher molecular weights than those autoclaved for 40 and 60 min. Passion fruit pectin extracted for 20 min was enzymatically modified with fungal pectinmethylesterase to create restructured gels. Short autoclave treatment (20 min) with citric acid as extractant resulted in a significant increase of gel strength, improving pectin extraction in terms of functionality. The treatment of solubilized material (pectic polysaccharides) in the presence of insoluble material (cellulose and hemicellulose) with pectinmethylesterase and calcium led to the creation of a stiffer passion fruit fiber pectin gel, while syneresis was not observed.

Pectolytic Enzymes of the Industrial Fungus Aspergillus kawachii

Carolina Elena Vita,Juan Carlos Contreras Esquivel,Claudio Enrique Voget 한국식품과학회 2009 Food Science and Biotechnology Vol.18 No.6

Aspergillus kawachii extracellular pectinases were screened in liquid cultures with different carbon sources. The fungus grown on citrus pectin or lemon pomace produced at least one of these inducible pectinases: acidic polygalacturonase, pectin lyase, pectin methylesterase, α-L-arabinofuranosidase, α-1,5-endoarabinase, β-D-galactosidase/exogalactanase, and β-1,4-endogalactanase. The lemon-pomace filtrates also contained significant α-L-rhamnosidase and β-D-fucosidase activities. Most of the screened pectinases were active at pH 2.0-2.5, indicating that the A. kawachii enzymes were acidophilic. Under the culture conditions employed we could not detect enzymatic degradation of soybean rhamnogalacturonan. The A. kawachii pectinase-production-related regulatory phenomena of induction-repression resemble those described for other Aspergillus sp.

ALCANCES Y RETOS DE LOS PROGRAMAS DE POLÍTICA PÚBLICA EN SALUD PARA LA DISCAPACIDAD AUDITIVA

Nancy Fabiola Moreno Zavala,José Manuel Rangel Esquivel Institute of Iberoamerican Studies Pusan Universit 2012 International Journal of Latin American Studies Vol.2 No.2

Abstract. This paper presents the evolution the public policy on the health attention of hearing impaired people in Mexico has had. A socio-historical reconstruction has been made from those policies in which the backlog generated from its society integration within the field of the laws, plans and programs of social development is stated. Likewise, there is a mention of the findings detected from the execution of a social action project focused on that group; those findings set the basis for further proposals or lines of investigation. As a conclusion, there are given guidelines to link the public policy proposals with the challenges for the social action with that specific population. Palabras clave: Política pública, discapacidad auditiva, salud, intervención, bienestar social. Key words: Public policy, auditory disability, health, intervention, social welfare. Ⅰ. Introducción. Resumen. En este trabajo se presenta la evolución que ha tenido la política pública en materia de atención a la salud de las personas con discapacidad auditiva en México. Se hace una reconstrucción socio-histórica de dichas políticas, en las cuales se pone de manifiesto el rezago generado con respecto a su integración a la sociedad dentro del marco de las leyes, artículos, planes y programas de desarrollo social. Asimismo, se hace mención de los hallazgos detectados a partir de la implementación de un proyecto de intervención social enfocado a este grupo poblacional, lo cual sienta las bases para el planteamiento de propuestas y líneas de investigación a futuro. Finalmente, se presenta a manera de conclusión, algunas directrices que articulan las propuestas de política pública con los retos para la intervención social con grupos de población con discapacidad auditiva.

Differences in Fungal Enzyme Productivity in Submerged and Solid State Cultures

Cristobal Noe Aguilar,Juan Carlos Contreras-Esquivel,Raul Rodriguez,Lilia Arely Prado,Octavio Loera 한국식품과학회 2004 Food Science and Biotechnology Vol.13 No.1