Antenatal depression among pregnant mothers in Afghanistan: a cross-sectional study

Background: Approximately one in five pregnant women experience antenatal depression globally. The purpose of the present study was to estimate the prevalence of antenatal depression and explore its relationship between various demographic variables, recent sexual engagement, and recent adverse life events among pregnant Afghan women. Methods: A cross-sectional survey study was carried out between January, 2023 and April 2023 among 460 women aged 15–45 years who were recruited using convenience sampling from Herat province (Afghanistan). Logistic regression models were utilized to explore the relationship between antenatal depression and socio-demographic characteristics among the participants. Results: The prevalence of antenatal depression symptoms was 78.5%. Multiple regression analysis indicated that antenatal depression was significantly associated with (i) being aged 30–45 years (AOR: 4.216, 95% CI: 1.868–9.515, p = .001), (ii) being of low economic status (AOR:2.102, 95% CI: 1.051–4.202, p = .036), (iii) not being employed (AOR: 2.445, 95% CI:1.189–5.025, p = .015), (iv) not having had sex during the past seven days (AOR: 2.335, 95% CI: 1.427–3.822, p = .001), and (v) not experiencing a traumatic event during the past month (AOR:0.263, 95% CI: 0.139–0.495, p < .001). Conclusion: The present study provides insight into the factors associated with the high prevalence of antenatal depression among pregnant Afghan women (e.g., demographic variables, recent adverse life events, and recent sexual engagement). It highlights the urgency of addressing antenatal depression in Afghanistan and provides a foundation for future research and interventions aimed at improving the mental health and well-being of pregnant women in the Afghan context

Carbon nanotube band structure effect on carbon nanotube field effect transistor

The band structure of a carbon nanotube (CNT) near to the minimum band energy is parabolic. However it is not parabolic in other parts of the band energy. In the parabolic part, based on the confinement effect, we present an analytical model that captures the essence of the physical processes relevant to the operation of a carbon nanotube field effect transistor (CNTFET). The model covers seamlessly the whole range of transport from drift-diffusion to ballistic. It has been clarified that the intrinsic speed of CNTs is governed by the transit time of electrons. Although the transit time is more dependent on the saturation velocity than on the weak-field mobility, the feature of high-electron mobility is beneficial in the sense that the drift velocity is always maintained closer to the saturation velocity, at least at the drain end of the transistor where the electric field is necessarily high and controls the saturation current. The results obtained are applied to the modeling of the current-voltage characteristics of a CNTFET. The channel-length modulation is shown to arise from the drain velocity becoming closer to the ultimate saturation velocity as the drain voltage is increased