Excellent Room-Temperature Thermoelectricity of 2D GeP3: Mexican-Hat-Shaped Band Dispersion and Ultralow Lattice Thermal Conductivity.

Although some atomically thin 2D semiconductors have been found to possess good thermoelectric performance due to the quantum confinement effect, most of their behaviors occur at a higher temperature. Searching for promising thermoelectric materials at room temperature is meaningful and challenging. Inspired by the finding of moderate band gap and high carrier mobility in monolayer GeP3, we investigated the thermoelectric properties by using semi-classical Boltzmann transport theory and first-principles calculations. The results show that the room-temperature lattice thermal conductivity of monolayer GeP3 is only 0.43 Wm-1K-1 because of the low group velocity and the strong anharmonic phonon scattering resulting from the disordered phonon vibrations with out-of-plane and in-plane directions. Simultaneously, the Mexican-hat-shaped dispersion and the orbital degeneracy of the valence bands result in a large p-type power factor. Combining this superior power factor with the ultralow lattice thermal conductivity, a high p-type thermoelectric figure of merit of 3.33 is achieved with a moderate carrier concentration at 300 K. The present work highlights the potential applications of 2D GeP3 as an excellent room-temperature thermoelectric material.

The calcium sensing receptor (CaSR) promotes Rab27B expression and activity to control secretion in breast cancer cells.

Chemotactic and angiogenic factors secreted within the tumor microenvironment eventually facilitate the metastatic dissemination of cancer cells. Calcium-sensing receptor (CaSR) activates secretory pathways in breast cancer cells via a mechanism driven by vesicular trafficking of this receptor. However, it remains to be elucidated how endosomal proteins in secretory vesicles are controlled by CaSR. In the present study, we demonstrate that CaSR promotes expression of Rab27B and activates this secretory small GTPase via PI3K, PKA, mTOR and MADD, a guanine nucleotide exchange factor, also known as DENN/Rab3GEP. Active Rab27B leads secretion of various cytokines and chemokines, including IL-6, IL-1ß, IL-8, IP-10 and RANTES. Expression of Rab27B is stimulated by CaSR in MDA-MB-231 and MCF-7 breast epithelial cancer cells, but not in non-cancerous MCF-10A cells. This regulatory mechanism also occurs in HeLa and PC3 cells. Our findings provide insightful information regarding how CaSR activates a Rab27B-dependent mechanism to control secretion of factors known to intervene in paracrine communication circuits within the tumor microenvironment.

Gastrostomía endoscópica percutánea asistida por laparoscopia: Reporte de caso / Laparoscopic-assisted percutaneous endoscopic gastrostomy: case report

La gastrostomía endoscópica percutánea (GEP) es la técnica de elección para instaurar una vía de alimentación en pacientes que requieren soporte nutricional especial por más de 4 semanas; sin embargo, por ser una intervención realizada de forma percutánea, la incapacidad para evidenciar transiluminación de la pared abdominal, así como la no obtención de convexidad con la dígito-presión son consideradas usualmente contraindicaciones para la realización del procedimiento. Se reporta un caso en el cual a pesar de presentarse una contraindicación para la realización de GEP, esta se hizo bajo guía laparoscópica, proporcionando así una alternativa mínimamente invasiva y evitando la realización de un procedimiento quirúrgico abierto.

Percutaneous endoscopic gastrostomy (PEG) is the choice technique to establish a feeding route for patients that requiring special nutritional support for more than 4 weeks; however, to be an intervention performed percutaneously, the inability to demonstrate transillumination of the abdominal wall and the failure to obtain convexity with the finger-pressure are usually considered contraindications for its realization. This report is about a case in which spite of a major contraindication for PEG, it was performed under laparoscopic guidance, thus providing a minimally invasive alternative, avoiding the realization of an open surgical procedure.

Tumores neuroendocrinos gastroenteropancreáticos / Gastroenteropancreatic neuroendocrine tumors (GEP-NETS)

Los tumores neuroendocrinos gastroenteropancreáticos son neoplasias raras distribuidas a lo largo del tubo digestivo y poseen características peculiares, como la captación de sales de plata, la expresión de marcadores de célula neuroendocrina y los gránulos secretorios de contenido hormonal. Según su tamaño, localización anatómica y la presencia de metástasis, estos tumores debutan con distintas características clínicas y pronóstico. El diagnóstico temprano, que requiere de un alto grado de sospecha y una confirmación con estudios especializados, resulta invaluable para tratar estas lesiones a tiempo y aumentar la sobrevida de los pacientes. El tratamiento quirúrgico es la herramienta de primera mano, y otras terapias médicas ayudan a mejorar los síntomas y la calidad de vida de aquellos pacientes con lesiones irresecables. En esta revisión, se tratan los aspectos más relevantes en cuanto a la clasificación, morfología, localización, diagnóstico y tratamiento de estas neoplasias gastrointestinales, y al final, se expone la única experiencia colombiana sobre la epidemiología y el manejo de los tumores neuroendocrinos.

Gastroenteropancreatic neuroendocrine tumors (GEP-NETS) are rare neoplasms which can occur anywhere in the gastrointestinal tract. Their particular characteristics include uptake of silver salts, neuroendocrine cell marker expression and hormonal secretory granules. Depending on their size, anatomical location and upon whether or not metastasis has occurred, these tumors can show different clinical patterns and have different prognoses. Early diagnosis is essential for treating these lesions and improving the patients’ prognoses, but it requires a high degree of suspicion and confirmation by special testing. Surgical treatment is the first choice, but other medical therapy can be helpful for patients who have unresectable disease. This review presents the most relevant aspects of classification, morphology, methods of locating tumors, diagnosis and treatment of GEP-NETS. It presents only the Colombian experience in the epidemiology and management of these tumors.

Células endócrinas do sistema gastroenteropancreático: conceitos, distribuição, secreções, ação e controle / Endocrine cells of the gastroenteropancreatic system: concepts, distribution, secretions, action and regulation / Células endocrinas del sistema gastroenteropancreático: conceptos, distribución, secreciones, accion y regulación

Os sistemas nervoso e endócrino estão integrados para controlar os eventos motores e secretores, envolvidos no processo de digestão e absorção dos nutrientes no trato gastrointestinal (TGI). Nesta revisão, foi enfocado o sistema gastroenteropancreático (GEP), como um sistema endócrino difuso, constituído por células endócrinas dispersas ao longo do epitélio de revestimento do trato gastrointestinal e no pâncreas. Sobre esse sistema foram abordados conceitos e formas de classificação, distribuição das células endócrinas ao longo do TGI, principais tipos de secreção dessas células e sua ação sobre os eventos da digestão, além de alguns processos regulatórios que controlam tal secreção.(AU)

The nervous and endocrine systems are integrated to control the motor and secretor events which are involved in the digestion and absorption process of the nutrients in the gastrointestinal tract (GIT). In this revision the gastroenteropancreatic (GEP) system was focused as a diffuse endocrine system constituted by endocrine cells dispersed along the epithelial lining of the gastrointestinal tract and in the pancreas. On this system, concepts and forms of classifi cation were discussed, as well as the distribution of the endocrine cells along the GIT, main types of secretion of these cells and their action on the events of the digestion, besides some regulatory processes which control such secretion.(AU)

Los sistemas nervioso y endocrino interactúan para el control de la motilidad y la secreción involucradas en los proceso de digestión y absorción de los nutrientes en el tracto gastrointestinal (TGI). Esta revisión fue enfocada en el sistema gastroenteropancreatico (GEP), el cual se caracteriza por ser un sistema endocrino difuso formado por células endocrinas dispersas a lo largo del epitelio de revestimiento del TGI y en el páncreas. Sobre este sistema fueron abordados conceptos y formas de la clasifi cación, así como la distribución de las células endocrinas a lo largo de TGI, principales tipos de secreción de éstas células y su acción sobre los eventos de la digestión, además de algunos procesos reguladores que controlan esa secreción.(AU)

Células endócrinas do sistema gastroenteropancreático: conceitos, distribuição, secreções, ação e controle / Endocrine cells of the gastroenteropancreatic system: concepts, distribution, secretions, action and regulation / Células endocrinas del sistema gastroenteropancreástica:conceptos, distribuición, secreciones, acción y regulación

RESUMO: Os sistemas nervoso e endócrino estão integrados para controlar os eventos motores e secretores, envolvidos no processo de digestão e absorção dos nutrientes no trato gastrointestinal (TGI). Nesta revisão, foi enfocado o sistema gastroenteropancreático (GEP), como um sistema endócrino difuso, constituído por células endócrinas dispersas ao longo do epitélio de revestimento do trato gastrointestinal e no pâncreas.Sobre esse sistema foram abordados conceitos e formas de classifi cação, distribuição das células endócrinas ao longo do TGI, principais tipos de secreção dessas células e sua ação sobre os eventos da digestão, além de alguns processos regulatórios que controlam tal secreção

RESUMEN: Los sistemas nervioso y endocrino interactúan para el control de la motilidad y la secreción involucradas en los proceso de digestión y absorción de los nutrientes en el tracto gastrointestinal (TGI). Esta revisión fue enfocada en el sistema gastroenteropancreatico (GEP), el cual se caracteriza por ser un sistema endocrino difuso formado por células endocrinas dispersas a lo largo del epitelio de revestimiento del TGI y en el páncreas. Sobre este sistema fueron abordados conceptos y formas de laclasifi cación, así como la distribución de las células endocrinas a lo largo de TGI, principales tipos de secreción de éstas células y su acción sobre los eventos de la digestión, además de algunos procesos reguladores que controlan esa secreción.

ABSTRACT: The nervous and endocrine systems are integrated to control the motor and secretor events which are involved in the digestion and absorption process of the nutrients in the gastrointestinal tract (GIT). In this revision the gastroenteropancreatic (GEP) system was focused as a diffuse endocrine system constituted by endocrine cells dispersed along the epithelial lining of the gastrointestinal tract and in the pancreas. On this system, concepts and forms of classifi cation were discussed, as well as the distribution of the endocrine cells along the GIT, main types of secretion of these cells and their action on the events of the digestion, besides some regulatory processes which control such secretion