Impacts of COVID-19 crisis and some related factors on the mental health of 37150 Vietnamese students: a cross-sectional online study.

BACKGROUND: University students are vulnerable to changes due to COVID-19 pandemic. Although warning has been made about the impact of this crisis on students' mental health, there are barely any sufficient study. This work investigated how the pandemic affected the mental health of students at the Vietnam National University of Ho Chi Minh City (VNU-HCMC) and efficiency of available mental health supportive methods. METHODS: An online survey was conducted among students at Vietnam National University of Ho Chi Minh City (VNU-HCMC) from October 18, 2021, to October 25, 2021. Microsoft Excel 16.51 (Microsoft, USA) and R language, Epi packages 2.44 and 4.1.1 (rdrr.io) were used for data analysis. RESULTS: Thirty-seven thousand one hundred fifty students participated in the survey, including 48.4% female and 51.6% male. Online learning pressure was mainly recorded (65.1%). Many students suffered from sleeping disorders (56.2%). Some reported being victims of abuse (5.9%). Female students expressed a significantly higher level of distress than males, particularly the feeling of ambiguity about the purpose of life (p-value < 0.0001, OR: 0.94, 95% CI: [0.95-0.98]). Third-year students suffered higher stress levels than others, especially in online learning (68.8%, p-value < 0.05). Mental health statuses among students of different lockdown status regions were not significantly different. Therefore, lockdown status did not affect the stress levels of students which suggested that poor mental health outcomes seemed to root in the suspension of everyday university life rather than the prohibition of going out. CONCLUSIONS: During COVID-19, students experienced lots of stress and mental problems. These findings underscore the importance of academic and innovative activities, bringing attention to the needs of interactive study and extra-curricular activities.

Optimal Nitrogen Incorporation in Nickel Silicide for Thermally Stable Contact Formation.

Nickel silicide (NiSi) is commonly used as a contact material for metal junctions but the poor thermal instability of NiSi above 600 °C has limited the further scaling down of devices and the implementation of novel schemes, such as monolithic 3-dimensional integration. This paper suggests a process to improve the thermal stability of NiSi through nitrogen incorporation during the silicidation process. The optimal level of nitrogen incorporation in NiSi reduced the nickel diffusion rate and enhanced the thermal stability by preventing the formation of a nickel disilicide phase. On the other hand, a higher level of N incorporation led to Ni3N formation, which impeded the complete transformation to NiSi. Therefore, it is essential to incorporate the optimal content of N. In this study, NiSi with 3.9% N incorporation showed superior electrical characteristics, such as the sheet resistance, junction leakage, and stable Schottky barrier height, even after high-temperature post silicidation annealing at 600 °C for 30 min.

Formation techniques for upper active channel in monolithic 3D integration: an overview.

The concept of three-dimensional stacking of device layers has attracted significant attention with the increasing difficulty in scaling down devices. Monolithic 3D (M3D) integration provides a notable benefit in achieving a higher connection density between upper and lower device layers than through-via-silicon. Nevertheless, the practical implementation of M3D integration into commercial production faces several technological challenges. Developing an upper active channel layer for device fabrication is the primary challenge in M3D integration. The difficulty arises from the thermal budget limitation for the upper channel process because a high thermal budget process may degrade the device layers below. This paper provides an overview of the potential technologies for forming active channel layers in the upper device layers of M3D integration, particularly for complementary metal-oxide-semiconductor devices and digital circuits. Techniques are for polysilicon, single crystal silicon, and alternative channels, which can solve the temperature issue for the top layer process.

Impact of Pt grain size on ferroelectric properties of zirconium hafnium oxide by chemical solution deposition.

The effects of the grain size of Pt bottom electrodes on the ferroelectricity of hafnium zirconium oxide (HZO) were studied in terms of the orthorhombic phase transformation. HZO thin films were deposited by chemical solution deposition on the Pt bottom electrodes with various grain sizes which had been deposited by direct current sputtering. All the samples were crystallized by rapid thermal annealing at 700 °C to allow a phase transformation. The crystallographic phases were determined by grazing incidence X-ray diffraction, which showed that the bottom electrode with smaller Pt grains resulted in a larger orthorhombic phase composition in the HZO film. As a result, capacitors with smaller Pt grains for the bottom electrode showed greater ferroelectric polarization. The smaller grains produced larger in-plane stress which led to more orthorhombic phase transformation and higher ferroelectric polarization.

Double-gate thin film transistor with suspended-gate applicable to tactile force sensor.

This paper presents a straightforward, low-cost, and effective integration process for the fabrication of membrane gate thin film transistors (TFTs) with an air gap. The membrane gate TFT with an air gap can be used as the highly sensitive tactile force sensor. The suspended membrane gate with an air gap as the insulator layer is formed by multiple photolithography steps and photoresist sacrificial layers. The viscosity of the photoresist and the spin speed was used to modify the thickness of the air gap during the coating process. The tactile force was measured by monitoring the drain current of the TFT as the force changed the thickness of the air gap. The sensitivity of the devices was enhanced by an optimal gate size and low Young's modulus of the gate material. This simple process has the potential for the production of small, versatile, and highly sensitive sensors.

Serological diagnosis of leprosy in patients in vietnam by enzyme-linked immunosorbent assay with Mycobacterium leprae-derived major membrane protein II.

A serological diagnostic test using phenolic glycolipid-I (PGL-I) developed in the 1980s is commercially available, but the method is still inefficient in detecting all forms of leprosy. Therefore, more-specific and -reliable serological methods have been sought. We have characterized major membrane protein II (MMP-II) as a candidate protein for a new serological antigen. In this study, we evaluated the effectiveness of the enzyme-linked immunosorbent assay (ELISA) using the MMP-II antigen (MMP-II ELISA) for detecting antibodies in leprosy patients and patients' contacts in the mid-region of Vietnam and compared to the results to those for the PGL-I method (PGL-I ELISA). The results showed that 85% of multibacillary patients and 48% of paucibacillary patients were positive by MMP-II ELISA. Comparison between the serological tests showed that positivity rates for leprosy patients were higher with MMP-II ELISA than with PGL-I ELISA. Household contacts (HHCs) showed low positivity rates, but medical staff members showed comparatively high positivity rates, with MMP-II ELISA. Furthermore, monitoring of results for leprosy patients and HHCs showed that MMP-II is a better index marker than PGL-I. Overall, the epidemiological study conducted in Vietnam suggests that serological testing with MMP-II would be beneficial in detecting leprosy.