Assessment of differences in morphological and physiological leaf lodging characteristics between two cultivars of Hippeastrum rutilum

Background Environmental lodging stress, which is a result of numerous factors, is characterized by uncertainty. However, several studies related to lodging in cereal crops have reported that lodging in the Hippeastrum rutilum environment is very rare. Hippeastrum rutilum is a garden flower with high ornamental value and abundant germplasm resources. Under past cultivation practices, it was found that the plant types of ‘Red Lion’, with red flowers, and ‘Apple Blossom’, with pink flowers, are quite different. The leaves of ‘Red Lion’ are upright, while the leaves of ‘Apple Blossom’ show lodging, which seriously affects its ornamental value. The aims of this study were to compare the differences between the two varieties with leaf lodging and upright leaves according to morphological and physiological attributes. In this study, karyotype analysis and phenotypic morphological and physiological characteristics were compared to explore the differences between the two plant types. Results The karyotype analysis of the two cultivars showed that their chromosome types were both tetraploid plants. The results showed that the lignin content in the leaves of ‘Red Lion’ was high, the cross-sectional structure of the leaf vascular bundle was more stable, and the chlorophyll content was high. In addition, significantly less energy was transferred to the electron transport chain (ETR) during the photoreaction. Similarly, the results regarding the maximum photosynthetic rate (Fv/Fm), nonphotochemical quenching (NPQ) and effective quantum yield of photosystem II photochemistry (△F/Fm′) all indicated that the photosynthetic capacity of “Red Lion” was greater than that of “Apple Blossom”, which was affected by leaf lodging. The size of the leaves was significantly smaller, and the leaf sag angle, leaf width, and leaf tip angle presented significantly lower values in ‘Red Lion’ than in ‘Apple Blossom’, which exhibits leaf sag. The difference in these factors may be the reason for the different phenotypes of the two cultivars. Conclusion The results of this study proved that lodging affects the photosynthetic capacity of Hippeastrum rutilum and revealed some indexes that might be related to leaf lodging, laying a theoretical foundation for cultivating and improving new varieties.

Preparedness of Frontline Doctors in Jordan Healthcare Facilities to COVID-19 Outbreak

The number of COVID-19 (Coronavirus Disease of 2019) cases in Jordan is rising rapidly. A serious threat to the healthcare system appears on the horizon. Our study aims to evaluate preparedness of Jordanian frontline doctors to the worsening scenario. It has a questionnaire-based cross-sectional structure. The questionnaire was designed to evaluate preparedness according to knowledge about virus transmission and protective measures, adherence to protection guidelines, and psychological impacts affecting doctors. Institutional factors affecting doctors’ readiness like adopting approach protocols and making protection equipment available were investigated; 308 doctors from different healthcare facilities participated (response rate: 53.9%). Approximately 25% of doctors (n = 77) previously took care of COVID-19 patients, and 173 (56.2%) have institutional COVID-19 approach protocols. Only 57 doctors (18.5%) reported all PPE (Personal Protective Equipment) available. The self-reported score of preparedness to deal with COVID-19 patients was 4.9 ± 2.4. Doctors having institutional protocols for dealing with COVID-19 cases and those with sustained availability of PPE reported higher scores of preparedness (5.5 ± 2.3 and 6.2 ± 2.1 with p < 0.001, respectively). Correlations with knowledge score, adherence to PPE score, and psychological impacts were investigated. The study revealed multiple challenges and insufficiencies that can affect frontline doctors’ preparedness. Policy makers are urged to take these findings into consideration and to act promptly.

Study of a SiC Trench MOSFET Edge-Termination Structure with a Bottom Protection Well for a High Breakdown Voltage

A novel edge-termination structure for a SiC trench metal–oxide semiconductor field-effect transistor (MOSFET) power device is proposed. The key feature of the proposed structure is a periodically formed SiC trench with a bottom protection well (BPW) implantation region. The trench can be filled with oxide or gate materials. Indeed, it has almost the same cross-sectional structure as the active region of a SiC trench MOSFET. Therefore, there is little or no additional process loads. A conventional floating field ring (FFR) structure utilizes the spreading of the electric field in the periodically depleted surface region formed between a heavily doped equipotential region. On the other hand, in the trenched ring structure, an additional quasi-equipotential region is provided by the BPW region, which enables deeper and wider field-spreading profiles, and less field crowding at the edge region. The two-dimensional Technology Computer Aided Design (2D-TCAD) simulation results show that the proposed trenched ring-edge termination structures have an improved breakdown voltage compared to the conventional floating field ring structure.

Effects of Cr, W, and Mo on the High Temperature Oxidation of Ni-Based Superalloys

The oxidation behavior of Ni–9.5Co–(8~12)Cr–(2.5~5.5)Mo–(4~8)W–3Al–5Ti–3Ta–0.1C–0.01B alloys was investigated at 850 °C and 1000 °C The mass change, the phase of oxides, and the cross-sectional structure of specimens were analyzed after cyclic oxidation tests. The oxide scale was composed mainly of Cr2O3 and NiCr2O4, but NiO, TiO2, and CrTaO4 were also found. Al2O3 was formed beneath the Cr oxide layer. The Cr oxide layer and internal Al oxide acted as barriers to oxidation at 850 °C, while Al oxide was predominantly protective at 1000 °C. Cr increased the mass gain after oxidation test at both temperatures. Mo increased the oxidation rate at 850 °C but decreased the oxidation rate at 1000 °C. W slightly increased the mass gain at 850 °C but did not produce a significant effect at 1000 °C. The effects of Cr, Mo, W, and the temperature were discussed as well as the volatilization of oxides, the valence number of elements, and diffusion retardation.