RESUMO
The current study presents the electronic and magnetic properties of monolayer ZrSe2nanoribbons. The impact of various point defects in the form of Zr or Se vacancies, and their combinations, on the nanoribbon electronic and magnetic properties are investigated using density functional theory calculations in hydrogen-terminated zigzag and armchair ZrSe2nanoribbons. Although pristine ZrSe2is non-magnetic, all the defective ZrSe2structures exhibit ferromagnetic behavior. Our calculated results also show that the Zr and Se vacancy defects alter the total spin magnetic moment with D6Se,leading to a significant amount of 6.34µB in the zigzag nanoribbon, while the largest magnetic moment of 5.52µB is induced by D2Se-2in the armchair structure, with the spin density predominantly distributed around the Zr atoms near the defect sites. Further, the impact of defects on the performance of the ZrSe2nanoribbon-based devices is investigated. Our carrier transport calculations reveal spin-polarized current-voltage characteristics for both the zigzag and armchair devices, revealing negative differential resistance (NDR) feature. Moreover, the current level in the zigzag-based nanoribbon devices is â¼10 times higher than the armchair devices, while the peak-to-valley ratio is more pronounced in the armchair-based nanoribbon devices. It is also noted that defects increase the current level in the zigzag devices while they lead to multiple NDR peaks with rather negligible change in the current level in the armchair devices. Our results on the defective ZrSe2structures, as opposed to the pristine ones that are previously studied, provide insight into ZrSe2material and device properties as a promising nanomaterial for spintronics applications and can be considered as practical guidance to experimental work.
RESUMO
BACKGROUND: Irritable bowel syndrome refers to a subgroup of disorders of gut-brain interaction associated with stress-related symptoms, but gastrointestinal infection can also be considered the leading risk factor. It is well reported that coronavirus disease 2019 can also result in gastroenteritis. Therefore, this study aimed to evaluate the incidence of post-infectious irritable bowel syndrome and stressful status among coronavirus disease 2019 patients. METHODS: This cross-sectional study was conducted on adults with coronavirus disease 2019 referred to the Infectious Disease Clinic in Iran from November 2020 to February 2021. Patients who met all eligibility criteria were included in the study. The data were collected using a demographic questionnaire, Rome IV criteria questionnaire, and Hospital Anxiety and Depression Scale. RESULTS: Totally, the data obtained from 233 eligible patients (136 women, 97 men; mean age 38.41) 11.52 (years) were collected and analyzed, and 53.2% of the cases had a moderate coronavirus disease 2019. The analysis showed that 27 (11.6%) patients suffered from irritable bowel syndrome symptoms based on Rome IV criteria after the recovery from the infection. Also, Hospital Anxiety and Depression Scale-based symptoms of depression and anxiety that occurred with coronavirus disease 2019 were reported in 27.4% and 36.9%, respectively. CONCLUSION: Our finding illustrated that irritable bowel syndrome symptoms based on Rome IV could occur in post-infected coronavirus disease 2019 patients. Also, Hospital Anxiety and Depression Scale-based symptoms of depression and anxiety were more common in females and coronavirus disease 2019 infected patients with clinical symptoms including cough, shortness of breath, and sore throat.