RESUMEN
Pentoxifylline (PTX), a non-selective phosphodiesterase inhibitor, has demonstrated protective effects against lung injury in animal models. Given the significance of pulmonary toxicity resulting from paraquat (PQ) exposure, the present investigation was designed to explore the impact of PTX on PQ-induced pulmonary oxidative impairment in male mice.Following preliminary studies, thirty-six mice were divided into six groups. Group 1 received normal saline, group 2 received a single dose of PQ (20 mg/kg; i.p.), and group 3 received PTX (100 mg/kg/day; i.p.). Additionally, treatment groups 4-6 were received various doses of PTX (25, 50, and 100 mg/kg/day; respectively) one hour after a single dose of PQ. After 72 hours, the animals were sacrificed, and lung tissue was collected.PQ administration caused a significant decrease in hematocrit and an increase in blood potassium levels. Moreover, a notable increase was found in the lipid peroxidation (LPO), nitric oxide (NO), and myeloperoxidase (MPO) levels, along with a notable decrease in total thiol (TTM) and total antioxidant capacity (TAC) contents, catalase (CAT) and superoxide dismutase (SOD) enzymes activity in lung tissue. PTX demonstrated the ability to improve hematocrit levels; enhance SOD activity and TTM content; and decrease MPO activity, LPO and NO levels in PQ-induced pulmonary toxicity. Furthermore, these findings were well-correlated with the observed lung histopathological changes.In conclusion, our results suggest that the high dose of PTX may ameliorate lung injury by improving the oxidant/antioxidant balance in animals exposed to PQ.
Asunto(s)
Antioxidantes , Peroxidación de Lípido , Pulmón , Paraquat , Pentoxifilina , Superóxido Dismutasa , Animales , Pentoxifilina/farmacología , Pentoxifilina/uso terapéutico , Paraquat/toxicidad , Ratones , Masculino , Pulmón/efectos de los fármacos , Pulmón/patología , Pulmón/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Antioxidantes/farmacología , Superóxido Dismutasa/metabolismo , Estrés Oxidativo/efectos de los fármacos , Catalasa/metabolismo , Inhibidores de Fosfodiesterasa/farmacología , Inhibidores de Fosfodiesterasa/uso terapéutico , Óxido Nítrico/metabolismo , Peroxidasa/metabolismo , Lesión Pulmonar/inducido químicamente , Lesión Pulmonar/tratamiento farmacológico , Hidrolasas Diéster Fosfóricas/metabolismoRESUMEN
OBJECTIVE: Reports regarding experienced teacher burnout in public schools are becoming a concerning issue. Although several therapeutic interventions have been proposed to alleviate burnout symptoms, CBT programs appear to be more practical with large effects on burnout. However, there is limited research investigating the effects of an adapted group-based CBT program on teacher burnout. METHODS: The Maslach Burnout Inventory-Educators Survey was administered to 201 teachers working in public schools in Iran. Initial analyses indicated burnout symptoms in 66 teachers, who were randomly assigned to either a CBT treatment program or a waitlist group. The treatment group attended an adapted group therapy program with various therapeutic coping strategies, cognitive restructuring techniques, and applied relaxation training to facilitate cognitive and behavior change. Multilevel modeling was used to estimate treatment effects on teachers' burnout symptoms. RESULTS: The results indicated the positive effects of the treatment program in improving teachers' emotional exhaustion, depersonalization, and reduced personal accomplishment, which remained significantly elevated at a 6-month follow-up of the intervention. However, treatment effects and improvements in outcome measures were larger for novice teachers. Accordingly, teaching experience moderated the relationship between the group conditions and burnout levels. CONCLUSIONS: The findings from the study suggest this culturally-adapted CBT intervention may contribute to overcoming occupational stressors and reducing teachers' burnout, which is critically important for sustaining the workforce.
Asunto(s)
Agotamiento Profesional , Terapia Cognitivo-Conductual , Humanos , Agotamiento Profesional/diagnóstico , Agotamiento Profesional/psicología , Encuestas y Cuestionarios , Emociones , IránRESUMEN
BACKGROUND AND OBJECTIVES: As a well-known phenomenon with significant social, biological, and psychological impacts, burnout syndrome has been viewed and treated from different therapeutic perspectives. However, few studies have evaluated interventions to prevent and alleviate teacher burnout. DESIGN: This study comprised a randomized controlled trial (RCT) of a group-based cognitive-behavioral therapy (CBT) program for teacher burnout, with assessments at pre-treatment, post-treatment, and 6-month follow-up. METHODS: The Maslach Burnout Inventory-Educators Survey (MBI-ES) was administered to 242 English language teachers with diverse professional profiles in Iran. Of these, 62 teachers with burnout symptoms were randomly assigned to either a group-based eight-week CBT treatment program or a waiting list control condition. RESULTS: The results of a series of mixed factorial ANOVAs demonstrated significantly greater improvements for the treatment compared to the control condition on the total score and three subscales of the MBI-ES (teachers' emotional exhaustion, depersonalization, and reduced personal accomplishment) at post-treatment, with treatment effects maintained at 6-month follow-up. CONCLUSIONS: This CBT intervention has promise for supporting teachers in stressful occupational conditions and reducing their burnout.
Asunto(s)
Agotamiento Profesional , Terapia Cognitivo-Conductual , Psicoterapia de Grupo , Humanos , Agotamiento Profesional/prevención & control , Encuestas y Cuestionarios , Terapia Cognitivo-Conductual/métodos , CogniciónRESUMEN
As the frontline of our education system, teachers endure greater job-related stress than other professionals, even under the best of circumstances. While they were already exposed to certain stressors affecting their emotional health, the pandemic outbreak introduced new challenges putting teachers at risk of experiencing higher rates of emotional distress. This longitudinal study aimed to identify changes in teaching stressors and teachers' coping strategies in the period before the pandemic to the immediate outbreaks of COVID-19 in Fall 2020. In addition, we examined the correlation of teachers' coping approaches with stress, anxiety, and depression to understand if coping strategies correlate and predict such emotional distress. To this end, 376 English as a foreign language (EFL) teachers in Iran in the first wave and 351 in the second wave completed a battery of validated inventories capturing their emotional distress, teaching stressors, and coping approaches. The mean scores of the stressors and coping strategies across two waves indicated significant shifts toward using functional coping strategies upon experiencing new demands. Furthermore, we found that novice teachers experienced higher rates of stress and anxiety, which were positively associated with dysfunctional coping strategies. The results of the stepwise regression analysis with (dys)functional coping strategies indicated that coping mechanisms significantly account for 25% of variances in stress, anxiety, and depression. The implications of the study regarding promoting teacher mental health through identifying the risk factors associated with dysfunctional coping strategies have been discussed.
RESUMEN
Dysfunctional workplace behavior (DWB) is a prevalent phenomenon in schools, which has adverse consequences for teachers and students. In addition to the known negative implications, little is known about the mechanism through which DWB functions. The purpose of this study was to explore the effects of DWB on teacher emotional exhaustion (EE) and understand whether perceived social support (PSS) moderates the mediating effect that anxiety has on the relationship between DWB and EE. A battery of measurement tools was administered to 249 English as a foreign language (EFL) teachers in Iran. Moderated mediation regressions were used to analyze survey data. Results indicated that anxiety mediated the relationship between DWB and EE. Additionally, it was found that PSS moderated the direct relationship between DWB and anxiety; and the indirect relationship between DWB and EE. DWB was more strongly associated with an increased incidence of anxiety and EE in teachers with low levels of PSS. Results highlight the need to understand the intervening factors and sources of EE to actively identify, assess, and control teachers' behavioral and mental health risk factors. Given the significant role of emotions in teacher well-being, it is imperative to develop effective interventions (e.g., promoting PSS and positive workplace behaviors) in order to optimize teachers' emotional and behavioral health.
RESUMEN
The outbreak of the COVID-19 pandemic has resulted in many emotional consequences for teachers, including feelings of isolation, loneliness, and hopelessness. However, evidence on the prevalence of hopelessness and the associated factors in teachers during the pandemic is limited. The purpose of this research was to examine the prevalence of hopelessness in public school teachers and identify risk factors associated with it. A sample of 168 teachers aged 25-49 years participated in the study by completing the Socio-Demographic Questionnaire, the Beck Hopelessness Scale (BHS), and the Multi-Dimensional Scale of Perceived Social Support (MSPSS). The results revealed a moderate level of experienced hopelessness in teachers. Hopelessness prevalence was also significantly different across teacher gender (males = 79%), age groups (>40 = 77%), socioeconomic status (poor socioeconomic status = 70%), educational level (high school teachers = 79%), professional experience (experienced teachers = 82%), and perceived social support (low perceived social support = 79%). The results of a logistic regression analysis confirmed the effects of these demographic and occupational attributes on hopelessness by explaining ~71% of the variance in hopelessness feelings. Higher odds ratios were associated with age, socioeconomic status, and perceived social support, signifying the prominence of these factors in predicting hopelessness. The study contributes to identifying and screening teachers at risk of hopelessness in public schools and recommends promoting collegial/superior support as well as a positive school climate as the protective factors against hopelessness.
RESUMEN
Vacuum breakdown is one of the main limitations to the operating accelerating gradient in radio frequency linear accelerators. Recent studies of copper cavities have been shown that harder copper conditions more quickly and can reach higher accelerating gradients than soft copper cavities. Exploiting this advantage requires the development of assembly methods that do not involve the copper-softening high-temperature heating cycles that are used in for example bonding and brazing. A shrink-fit method, which was already implemented successfully in the operation the IPM linac, is proposed for the construction high-gradient test S-band standing wave structure operating at 2998.5 MHz. The three cells cavity is designed to have a maximum gradient in the middle cell that is twice that of the adjacent cells. Mechanical considerations relating to the shrink-fit construction method have been performed using Ansys. To validate the simulations and ensure the feasibility of construction by shrink-fit method, a sample cavity was constructed and cold tests was performed.
RESUMEN
Our aim was to report techniques and our experience in One-stage angioplasty and stenting of ostium of left common carotid and left internal carotid arteries in an octogenarian man with transient ischemic attack, who was completely recovered from neurologic insults short time after the procedure. An 81-year-old man presented with a transient ischemic attack. Neurologic examination showed left side transient visual obscuration or amaurosis fugax and right hemiparesis. Carotid duplex imaging revealed an 80% stenosis of the left internal carotid artery (LICA) and 95 % of the ostium of left common carotid artery (left CCA). Immediate brain MRI wasn't possible. Angioplasty and stenting of both lesions (left CCA and LICA ) was performed successfully without complications in one session. Stenting of common carotid artery ostial lesion and internal carotid artery (due to significant lesion) in one session could be done even in acute neurologic phase and also in very old patients, provided that, considering technical ways for neuroprotection and avoidance of other complications.
Asunto(s)
Angioplastia/métodos , Estenosis Carotídea/cirugía , Ataque Isquémico Transitorio/cirugía , Stents , Anciano de 80 o más Años , Arteria Carótida Común , Arteria Carótida Interna , Humanos , MasculinoRESUMEN
An electron accelerator, ILU-14, with current of 10 mA and 100 kW in power has been considered as one of the options for neutron source in Boron Neutron Capture Therapy (BNCT). The final design of neutron target has been obtained using MCNPX to optimize the neutron production. Tungsten in strip shape and D2O in cylindrical form have been proposed as the photon converter and the photoneutron target, respectively. In addition calculation of heat deposition in the photon target design has been considered to ensure mechanical stability of target. The results show that about 8.37×10(12) photoneutron/s with average energy of 615 keV can be produced by this neutron source design. In addition, using an appropriate beam shaping assembly an epithermal neutron flux of the order of 1.24×10(8) cm(-2) s(-1) can be obtained for BNCT applications.