Dipole formation at metal/PTCDA interfaces: Role of the Charge Neutrality Level

The formation of a metal/PTCDA (3, 4, 9, 10-perylenetetracarboxylic dianhydride) interface barrier is analyzed using weak-chemisorption theory. The electronic structure of the uncoupled PTCDA molecule and of the metal surface is calculated. Then, the induced density of interface states is obtained as a function of these two electronic structures and the interaction between both systems. This induced density of states is found to be large enough (even if the metal/PTCDA interaction is weak) for the definition of a Charge Neutrality Level for PTCDA, located 2.45 eV above the highest occupied molecular orbital. We conclude that the metal/PTCDA interface molecular level alignment is due to the electrostatic dipole created by the charge transfer between the two solids.Comment: 6 page

CAUSAS DE EXCLUSÃO DE DOADORES VIVOS DE RIM NO SERVIÇO DE TRANSPLANTE DE UM HOSPITAL DE TERCEIRO NÍVEL NO NOROESTE DO MÉXICO

Objective: To identify the causes for exclusion of living kidney donors at a third-level hospital in northwestern Mexico. Materials and methods: An observational, cross-sectional, descriptive and retrospective study, in which the medicalrecords of candidates for living kidney donation were evaluated from January 1, 2019 to December 31, 2021. Results: Out of the 30 selected records, only 6.6 % (2) were chosen as donors, i.e., the rejection rate of the potential candidates was 93.3 % (28). The average age was 40.7 years; when divided into age groups, it was observed that 7.44 % were ≤ 39 years, 5.31 % were ≥ 50 years and 4.25 % were in the 40–49 age range. The main pathologies that caused therejection of living donors were chronic diseases such as unknown renal disease, obesity, diabetes mellitus, systemic hypertension and heart diseases, which accounted for 60.7 %. The desire to donate was more frequent among blood relatives than non-blood relatives. In the case of blood relatives, i.e., siblings, parents, children, uncles, aunts, etc., 64.2 % were rejected, while 34.7 % of non-blood relatives, including spouses and friends, were rejected.Conclusions: Based on the body mass index (BMI), the results showed that overweight and obesity were the main causes of exclusion, a situation that is consistent with the Mexican epidemiological profile. The number of living donors at ourcenter has been reduced because most of the population is not healthy and has obesity, which affects the willingness to be a candidate for living kidney donation.Objetivo: Identificar las causas de exclusión de los donantes renales vivos en un centro hospitalario de tercer nivel en el noroeste de México.Materiales y métodos: Estudio de tipo observacional, transversal, descriptivo, retrospectivo. Se realizó la evaluación de los expedientes clínicos de los candidatos vivos para donación renal, que abarcó el periodo comprendido entre el 1 de enero de 2019 y el 31 de diciembre de 2021. Resultados: De los 30 expedientes seleccionados, solo se eligieron 2 (6,6 %) donadores, es decir, existió un índice de rechazo de 28 (93,3 %) de los potenciales candidatos. La edad promedio fue de 40,7 años; al dividirlos en grupos de edad, se observó que el 7,44 % fueron ≤39 años; el 5,31 %, ≥50 años; y el 4,25 %, de 40 a 49 años. Dentro de las principales patologías que originaron el rechazo del donador vivo se encuentran las enfermedades crónicas, como afección renal desconocida, obesidad, diabetes mellitus, hipertensión arterial sistémica y cardiopatías, que representaron el 60,7 %. El deseo de donares más frecuente entre consanguíneos que en no consanguíneos. En el caso de los consanguíneos, es decir, hermanos, padres, hijos, tíos, etc., el 64,2 % fue rechazado; en los no consanguíneos, el 34,7 %, que incluía a esposos y amigos. Conclusiones: Los resultados obtenidos sobre el índice de masa corporal (IMC) mostraron que el sobrepeso y laobesidad fueron las principales causas de exclusión, circunstancia que es particular en nuestro país respecto a su perfil epidemiológico. La cantidad de donantes vivos en nuestro centro se redujo porque la mayor parte de la población no es sana, padece obesidad y ello repercute al momento de presentarse como candidato a donante.Resumo Objetivo: Identificar as causas de exclusão de doadores vivos de rim. Material e métodos: Estudo observacional, transversal, descritivo, retrospectivo, no qual é realizada a análise dos prontuários de possíveis doadores de rim no período de 1º de janeiro de 2019 a 31 de dezembro de 2021. Identificar diagnósticos que excluam uma pessoa como doador. Resultados: Dos 30 arquivos selecionados, apenas 2 (6,6%) foram escolhidos como doadores, ou seja, houve uma taxa de rejeição de 28 (93,3%). Os principais motivos de rejeição foram doenças crônicas, indicando 60,7% em que se encontraram doença renal desconhecida, obesidade, diabetes mellitus, hipertensão arterial sistêmica e cardiopatia. Conclusão: Os resultados obtidos no índice de massa corporal (IMC) mostraram o sobrepeso e a obesidade como uma das principais causas de exclusão com 21,4%, informação semelhante à de Lapasia et al., que descreve a obesidade como a principal causa de rejeição representando quase 40% dos doadores. Ezzaki et al, também a descrevem como causa de exclusão

Fuzzy Networked Control Systems Design Considering Scheduling Restrictions

Nowadays network control systems present a common approximation when connectivity is the issue to be solved based on time delays coupling from external factors. However, this approach tends to be complex in terms of time delays. Therefore, it is necessary to study the behavior of the delays as well as the integration into differential equations of these bounded delays. The related time delays needs to be known a priory but from a dynamic real-time behavior. To do so, the use of priority dynamic Priority exchange scheduling is performed. The objective of this paper is to show a way to tackle multiple time delays that are bounded and the dynamic response from real-time scheduling approximation. The related control law is designed considering fuzzy logic approximation for nonlinear time delays coupling, where the main advantage is the integration of this behavior through extended state space representation keeping certain linear and bounded behavior and leading to a stable situation during events presentation by guaranteeing stability through Lyapunov

Barrier formation at organic interfaces in a Cu(100)-benzenethiolate-pentacene heterostructure

The energy level alignment at the metal-organic and organic-organic interfaces of the Cu(100)/benzenethiolate/pentacene heterostructure is studied by photoemission spectroscopy and discussed theoretically using a model that includes, in a consistent way, charge transfer, Pauli repulsion, intrinsic molecular dipoles, and interface screening as a function of coverage. Despite the different nature of the two interfaces, our model provides a unified explanation for the work-function changes at both junctions and enables us to determine the benzenethiolate orientation as a function of coverage

Barrier formation at metal/organic interfaces: dipole formation and the Charge Neutrality Level

The barrier formation for metal/organic semiconductor interfaces is analyzed within the Induced Density of Interface States (IDIS) model. Using weak chemisorption theory, we calculate the induced density of states in the organic energy gap and show that it is high enough to control the barrier formation. We calculate the Charge Neutrality Levels of several organic molecules (PTCDA, PTCBI and CBP) and the interface Fermi level for their contact with a Au(111) surface. We find an excellent agreement with the experimental evidence and conclude that the barrier formation is due to the charge transfer between the metal and the states induced in the organic energy gap.Comment: 7 pages, Proceedings of ICFSI-9, Madrid, Spain (September 2003), special issue of Applied Surface Science (in press

Relación entre la cantidad de ARN total hepático y algunos parámetros sanguíneos en la diabetes mellitus experimental

La diabetes mellitus (DM) ha sido asociada con alteraciones de expresión génica en tejidos sensibles a la insulina. El objetivo de este estudio fue determinar la cantidad de ARN total en células hepáticas y su relación con ciertos parámetros sanguíneos vinculados directa o indirectamente con la DM. Se utilizaron ratones adultos NMRI de sexo hembra, distribuidas en tres grupos (0; 15 y 30 días post–inducción). A los grupos de 15 y 30 días se les administró ip 40 mg/kg de estreptozotocina durante 5 días. A todos los grupos se les efectuaron determinaciones sanguíneas de glucosa, proteínas totales, triglicéridos y hemoglobina. Semanalmente se determinaron en forma cualitativa pH, glucosa y cuerposcetónicos en orina. Todos los animales se sacrificaron bajo ligera eterización y en hígadose determinaron ARN total y proteínas totales. Se encontró un aumento significativo en losniveles de glucosa en los animales de 15 y 30 días post–inducción, en comparación al grupo0 días. El ARN total aumentó significativamente a los 15 días post–inducción, mientras quea los 30 días los animales presentaron una disminución marcada incluso por debajo de los niveles encontrados al día 0. Al correlacionar el ARN total hepático con los parámetros sanguíneos, se observó que a medida que aumentaban los valores de ARN, se incrementaban los de glucosa (r= 0,60; p< 0,01). Se concluye que en la DM experimental se modifica la expresión génica hepática, cambio que guarda relación con los niveles de glucosa sanguínea

An implicit unsteady hydraulic solver for suspended cuttings transport in managed pressure wells

We present a simulation tool for transient events in complex hydraulic networks. The code includes modelling of the transport of suspended cuttings in near-vertical wells. An unstructured finite volume formulation with implicit time integration has been chosen. The unconditional stability of the integrator makes the method suitable for the simulation of transient events over a wide range of characteristic timescales. It handles both very fast transients (e.g. fluid hammer events) and the long-term evolution of the well (e.g. hole cleaning operations). The software has been developed to address the need of the oil industry for a robust and efficient predictive tool allowing effective well control in managed pressure drilling operations. The physical modelling follows the standard practices accepted by the industry (e.g. mud rheology computations). The mathematical foundation of the algorithm is described followed by validation cases that illustrate its capabilities and accuracy. Finally, a practical industrial application example is provided to demonstrate the real-world performance of the software.Peer ReviewedPostprint (author's final draft

Osmotic stress tolerance in forage oat varieties (Avena Sativa L.) based on osmotic potential trials

Received: April 1st, 2022 ; Accepted: December 12th, 2022 ; Published: February 7th, 2023 ; Correspondence: [email protected]; [email protected] oats (Avena sativa L.) are globally important for milk and meat production, and, to a lesser extent, for the human diet. In Mexico, oats are a strategic crop, occupying the fourth place in cultivated area, only after maize for grain, bean, and sorghum for grain. Droughts are the main problem for oat production in Mexico. This study evaluated the germination and seedling growth of several oat varieties in response to drought stress simulated by PEG-6000 treatments of different osmotic pressure in order to identify drought-resistant genotypes. The Teporaca genotype was the most outstanding in the three levels of OP compared to its control with 0.0 of Osmotic Potential (OP). The Teporaca genotype showed the largest root length and the lowest diminishment of root length under osmotic stress conditions. This genotype also had the largest shoot length in the three osmotic stress levels. Regarding root fresh weight, Babicora stands out with 98.5% and Teporaca with 43% in the most severe level. Teporaca, Menonita, and Babicora showed the outstanding root dry weights of 346.5%, 327.2%, and 251.2%, respectively. These varieties had higher root dry weight than their own controls in water in the most severe level of OP. In conclusion, the Teporaca, Menonita, and Karma genotypes showed the highest osmotic stress tolerance and could be used as sources of favorable alleles to improve oat drought tolerance