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Charged Particle in a Flat Box with Static Electromagnetic Field and Landau’s Levels

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Journal of Modern Physics 2020年第10期11卷 1731-1742页

作者： Gustavo V. López Jorge A. Lizarraga departamento de Física Universidad de Guadalajara Guadalajara México

We study the quantization of a charged particle motion without spin inside a flat box under a static electromagnetic field. Contrary to Landau’s solution with constant magnetic field transverse to the box and using Fourier transformation, we found a full solution for the wave function which is different from that one given by Landau, and this fact remains when static electric field is added. However, the Landau’s levels appear in all cases.

关键词： Landau’s Levels Quantum Hall Effect Flat Box

EEG Correlations during a Working Memory Task with Emotional Stimuli in Girls with Post-Traumatic Stress Disorder Secondary to Sexual Abuse

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Journal of Behavioral and Brain Science 2016年第12期6卷 509-529页

作者： Araceli Sanz-Martin Ivette Calderón-Zepeda Instituto de Neurociencias Universidad de Guadalajara Guadalajara Jalisco México

Survivors of Child Sexual Abuse (CSA) can develop Post-Traumatic Stress Disorder (PTSD), alterations in the prefrontal cortex, changes in electroencephalographic (EEG) activity, and lower performance on working memory tasks. The aim of this study was to characterize brain electrical correlations in girls with PTSD secondary to CSA during a working memory task based on recognizing emotional facial stimuli. Girls aged 8 - 16 years old were evaluated: 12 with PTSD secondary to CSA, and 12 healthy girls with no history of abuse. EEG activity during a working memory task with emotional stimuli was recorded, and the inter- and intra-hemispheric correlations that assessed the functional connectivity among different cortical regions were analyzed. The PTSD group showed lower performance than controls on the working memory task while watching happy faces, while the EEG of this group showed greater intrahemispheric correlation among frontal areas and between frontal and posterior cortical regions. Also, the PTSD group had lower interhemispheric correlations between posterior temporal areas. The higher intrahemispheric correlation in the PTSD group could indicate that those girls used more brain areas when performing the task, likely because it required greater effort. The lower inter-posterior temporal correlation could be attributed to a reduction of the corpus callosum.

关键词： Child Sexual Abuse PTSD Working Memory Emotional Stimuli EEG Correlation Early Stress

Differential Effect of Acute Stress on Visuospatial Working Memory and Sexual Motivation in Male Rats

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Journal of Behavioral and Brain Science 2015年第7期5卷 221-230页

作者： Marisela Hernández-González Enrique Hernández-Arteaga Mayra Linné Almanza-Sepúlveda Miguel ángel Guevara Instituto de Neurociencias Universidad de Guadalajara Guadalajara Jalisco México

Working memory is an executive function that is highly dependent on the functioning of the prefrontal cortex. Several studies using food or drink as rewards have demonstrated that rats are capable of performing tasks that involve working memory. Sexual behavior is another highly-rewarding, motivated behavior that has proven to be an efficient incentive in classical operant tasks. Considering that both sexual behavior and working memory are sensitive to the effects of stress, the aim of this study was to determine the effect of acute stress on visuospatial working memory during a sexually-motivated task (a nonmatching-to-sample task in a T-maze) in male rats. Thirty-two male Wistar rats were trained in the T-maze using sexual interaction (intromission and ejaculation) as a reinforcer during a 4-day training period (training sessions held every 4th day). On the basis of their performance, the rats were classified as good-learners (n = 12) and bad-learners (n = 20), and on the fifth day, 6 good-learners and 10 bad-learners were subjected to stress using the cold water immersion model (CWI, 15°C) for 15 minutes before they were evaluated in the T-maze. The remaining rats made up the control group (i.e., they performed the task without previous stress). Results showed that acute stress by CWI improved working memory in the bad-learners but did not affect the performance of the good-learners, although in both groups (good- and bad-learners) stress decreased the sexual motivation to perform the task. It is probable that the increased levels of corticosterone in the stress situation could activate glutamatergic transmission in the prefrontal cortex, thus facilitating working memory and, simultaneously, decreasing testosterone levels, which exerts a negative effect on sexual motivation in these male rats.

关键词： Stress Working Memory Sexual Behavior

Prefrontal-Parietal Correlation during Performance of a Visuospatial Working Memory Task in Children, Adolescents and Young Adults

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Journal of Behavioral and Brain Science 2015年第10期5卷 448-457页

作者： Miguel Angel Guevara Jorge Carlos Hevia-Orozco Araceli Sanz-Martin Lucía Ester Rizo-Martínez Marisela Hernández-González Mayra Linné Almanza-Sepúlveda Instituto de Neurociencias CUCBA Universidad de Guadalajara Guadalajara México

development of the prefrontal cortex and its connectivity with different cortical areas has strong implications for the improvement of working memory. The aim of this research was to characterize the interhemispheric (INTER) prefrontal and hemispheric (INTRA) frontopolar-dorsolateral prefrontal and dorsolateral prefrontal-parietal correlation (r) in children, adolescents and adults during performance of a visuospatial working memory task (VSWM). INTERr and INTRAr of 36 different aged male participants (11 - 13, 18 - 20 and 26 - 30 years old) were calculated during performance of the Corsi Block-Tapping task, which assessed VSWM. On this task, children showed lower correct responses than adolescents and adults. Adults also showed lower total execution times than children and adolescents, with a more efficient performance. On the EEGs, the older groups showed both higher interfrontal correlations and left and right prefronto-parietal correlations than children. According to our results, the progressive efficiency in VSWM is related to differences in EEG patterns among children, adolescents and adults.

关键词： Corsi Block-Tapping Task EEG Correlations development Visuospatial Working Memory

Ninety-day readmissions after inpatient cholecystectomy: A 5-year analysis

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World Journal of Gastroenterology 2017年第16期23卷 2972-2977页

作者： Alba Manuel-Vázquez Raquel Latorre-Fragua Carmen Ramiro-Pérez Aylhin López-Marcano Farah Al-Shwely Roberto de la Plaza-Llamas JoséManuel Ramia department of General and Digestive Surgery University Hospital of Guadalajara19002 GuadalajaraSpain

AIM To determine the incidence of readmission after cholecystectomy using 90 d as a time limit. METHODS We retrospectively reviewed all patients undergoing cholecystectomy at the General Surgery and Digestive System Service of the University Hospital of guadalajara, Spain. We included all patients undergoing cholecystectomy for biliary pathology who were readmitted to hospital within 90 d. We considered readmission to any hospital service as cholecystectomyrelated complications. We excluded ambulatory cholecystectomy, cholecystectomy combined with other procedures, oncologic disease active at the time of cholecystectomy, finding of malignancy in the resection specimen, and scheduled re-admissions for other unrelated pathologies. RESULTS We analyzed 1423 patients. There were 71 readmissions in the 90 d after discharge, with a readmission rate of4.99%. Sixty-four point seven nine percent occurred after elective surgery(cholelithiasis or vesicular polyps) and 35.21% after emergency surgery(acute cholecystitis or acute pancreatitis). Surgical non-biliary causes were the most frequent reasons for readmission, representing 46.48%; among them, intra-abdominal abscesses were the most common. In second place were non-surgical reasons, at 29.58%, and finally, surgical biliary reasons, at 23.94%. Regarding time for readmission, almost 50% of patients were readmitted in the first week and most second readmissions occurred during the second month. Redefining the readmissions rate to 90 d resulted in an increase in re-hospitalization, from 3.51% at 30 d to 4.99% at 90 d. CONCLUSION The use of 30-d cutoff point may underestimate the incidence of complications. The current tendency is to use 90 d as a limit to measure complications associated with any surgical procedure.

关键词： Cholecystectomy 90-d Hospital readmission Readmission rate Cholelithiasis

One Dimensional Relativistic Free Particle in a Quadratic Dissipative Medium

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Journal of Modern Physics 2015年第2期6卷 121-125页

作者： G. V. López G. C. Montes J. G. T. Zanudo departamento de Fsica Universidad de Guadalajara Guadalajara México

The deduction of a constant of motion, a Lagrangian, and a Hamiltonian for relativistic particle moving in a dissipative medium characterized by a force which depends on the square of the velocity of the particle is done. It is shown that while the trajectories in the space (x,v), defined by the constant of motion, look as one might expected, the trajectories in the space (x,p), defined by the Hamiltonian, have an odd behavior.

关键词： Lagrangian Hamiltonian Constant of Motion Dissipation Relativistic

Generalization of the Force Approach to Radiation Reaction

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Journal of Applied Mathematics and Physics 2017年第3期5卷 569-573页

作者： Gustavo V. López departamento de Física Universidad de Guadalajara Guadalajara Mexico

A new approach to radiation reaction for the correction of the linear and circular motion of a charged particle takes into account the emission of electromagnetic radiation due to its acceleration. This new formulation was based on expressing the radiation reaction force in terms of the external force rather than the acceleration of the charge. In this paper, a generalization of the radiation reaction force in terms of the external force approach is formulated for any arbitrary motion of the charged particle. This generalization includes the linear and circular acceleration cases previously investigated.

关键词： Synchrotron Radiation Radiation Reaction Force Relativistic Charged Particle

EEG Correlations during WCST Performance in Female Adolescents with Sexual Abuse-Related Post-Traumatic Stress Disorder

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Journal of Behavioral and Brain Science 2015年第7期5卷 239-250页

作者： Lucía Ester Rizo-Martínez Araceli Sanz-Martin Miguel ángel Guevara Marisela Hernández-González Olga Inozemtseva Francisco Abelardo Robles-Aguirre Instituto de Neurociencias CUCBA Universidad de Guadalajara Guadalajara México Centro Universitario del Norte Universidad de Guadalajara Colotlán México

Child sexual abuse (CSA) survivors can present post-traumatic stress disorder (PTSD) and alterations in EEG activity and cognition. The aim of this study was to evaluate EEG correlations in female adolescents with CSA-related PTSD during performance of the Wisconsin Card-Sorting Test (WSCT). Inter- and intrahemispheric EEG correlations (INTERr and INTRAr) of those subjects were calculated at rest and during performance of WCST. On this task, the PTSD group obtained higher scores than the control group for the number of correct responses and failure to maintain set. In the between-groups comparisons, the PTSD group presented a higher INTERr between frontal areas in the gamma and slow bands, as well as a higher correlation in the delta band at Fp1-F3;however, this group presented a lower INTRAr between Fp1-P3 and Fp2-P4 in the theta and alpha1 bands. In the comparison between conditions, the PTSD group presented an increased correlation during execution of the WCST, mainly in the gamma band, while the control group showed a decrease of INTRAr in the slow bands. Results are discussed with respect to the influence of CSA- related PTSD on the development of cognition and functional connectivity in the brain.

关键词： Child Sexual Abuse Post-Traumatic Stress Disorder EEG Correlation WCST Adolescents

Characteristics of Toxic Waste from Nine Casting Industries According to Mexican Standards:Prospective Study of West Mexico

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Journal of Geoscience and Environment Protection 2017年第3期5卷 43-49页

作者： Walter Ramírez-Meda José de Jesús Bernal-Casillas Luis Alberto López-Tejeda Gilberto íniguez-Covarrubias departamento de Ingeniería de Proyectos Universidad de GuadalajaraCUCEIGuadalajaraMéxico

This research analyzed nine casting industries located in western Mexico and their waste streams, including slags, sand, dust and sludge. All of these are considered dangerous by Mexican Legislation due to their concentrations of heavy metals. Analytical results show that lead is the main problem in these wastes. Field sampling showed that these industries do not have any protocol for waste handling and storage.

关键词： Dangerous Waste Metal Casting Slag Sand Mexican Legislation TCLP