Drought, Low Nitrogen Stress, and Ultraviolet-B Radiation Effects on Growth, Development, and Physiology of Sweetpotato Cultivars during Early Season

Drought, ultraviolet-B (UV-B), and nitrogen stress are significant constraints for sweetpotato productivity. Their impact on plant growth and development can be acute, resulting in low productivity. Identifying phenotypes that govern stress tolerance in sweetpotatoes is highly desirable to develop elite cultivars with better yield. Ten sweetpotato cultivars were grown under nonstress (100% replacement of evapotranspiration (ET)), drought-stress (50% replacement of ET), UV-B (10 kJ), and low-nitrogen (20% LN) conditions. Various shoot and root morphological, physiological, and gas-exchange traits were measured at the early stage of the crop growth to assess its performance and association with the storage root number. All three stress factors caused significant changes in the physiological and root- and shoot-related traits. Drought stress reduced most shoot developmental traits (29%) to maintain root growth. UV-B stress increased the accumulation of plant pigments and decreased the photosynthetic rate. Low-nitrogen treatment decreased shoot growth (11%) and increased the root traits (18%). The highly stable and productive cultivars under all four treatments were identified using multitrait stability index analysis and weighted average of absolute scores (WAASB) analyses. Further, based on the total stress response indices, ‘Evangeline’, ‘O’Henry’, and ‘Beauregard B-14’ were identified as vigorous under drought; ‘Evangeline’, ‘Orleans’, and ‘Covington’ under UV-B; and ‘Bonita’, ‘Orleans’, and ‘Beauregard B-14’ cultivars showed greater tolerance to low nitrogen. The cultivars ‘Vardaman’ and ‘NC05-198’ recorded a low tolerance index across stress treatments. This information could help determine which plant phenotypes are desirable under stress treatment for better productivity. The cultivars identified as tolerant, sensitive, and well-adapted within and across stress treatments can be used as source materials for abiotic stress tolerance breeding programs.

The influences of radiation effects on DC/RF performances of Lg=22 nm gate-all-around nanosheet field-effect transistor

In this paper, we carried out detailed TCAD simulations to investigate the radiation effects, e.g., total ionizing dose (TID) and single-event effects (SEEs), on direct current (DC) and radio frequency (RF) characteristics of the gate-all-around (GAA) nanosheet field-effect transistor (FET). The simulation model used is composed of 7-layer stacked GAA nanosheet FET with Lg=22 nm, which was implemented in this study. The open current and the drain-induced barrier lowering of the device are ~ 3mA/μm and 47mV/V, respectively. The results indicate that the TID have little influence on the DC and RF characteristics when the transistor is working in an open state. During the SEEs simulation, we considered three incident directions for the high energy particle, including the lateral direction of the channels, the vertical direction of the channels and the top of the channels. The influence of the particle injecting along the lateral and vertical directions of the channels shows stronger relation with the distance from the incident point compared to the influence of the particle from the top. Besides, the general influence of the particle injecting along the lateral directions of the channels is higher than the other two directions. The total injected charge of the particle injecting along the lateral direction, along the vertical direction and from the top are 3 fC, 1.4 fC and 2.1 fC, respectively. As compared to the FinFET, the GAA nanosheet has superior RF performances and less sensitivity to TID effect. This work can provide a guideline for the GAA nanosheet devices in aerospace and avionic RF applications.

Radiation-Induced Alterations in Proliferation, Migration, and Adhesion in Lens Epithelial Cells and Implications for Cataract Development

The lens of the eye is one of the most radiosensitive tissues. Although the exact mechanism of radiation-induced cataract development remains unknown, altered proliferation, migration, and adhesion have been proposed as factors. Lens epithelial cells were exposed to X-rays (0.1–2 Gy) and radiation effects were examined after 12 h and 7 day. Proliferation was quantified using an MTT assay, migration was measured using a Boyden chamber and wound-healing assay, and adhesion was assessed on three extracellular matrices. Transcriptional changes were also examined using RT-qPCR for a panel of genes related to these processes. In general, a nonlinear radiation response was observed, with the greatest effects occurring at a dose of 0.25 Gy. At this dose, a reduction in proliferation occurred 12 h post irradiation (82.06 ± 2.66%), followed by an increase at 7 day (116.16 ± 3.64%). Cell migration was increased at 0.25 Gy, with rates 121.66 ± 6.49% and 232.78 ± 22.22% greater than controls at 12 h and 7 day respectively. Cell adhesion was consistently reduced above doses of 0.25 Gy. Transcriptional alterations were identified at these same doses in multiple genes related to proliferation, migration, and adhesion. Overall, this research began to elucidate the functional changes that occur in lens cells following radiation exposure, thereby providing a better mechanistic understanding of radiation-induced cataract development.

Public Control of Radiation Hazardous Facilities: Experience and Results

Independent public control of nuclear facilities is aimed at raising awareness of the general public about the effectiveness of measures to protect the environment from the radiation effects. The experience and the result of interaction between specialists of the Academy of Sciences and a higher school in organizing and conducting public control by instrumental methods of the territories for the location of radiation-hazardous facilities: uranium mining sites by underground leaching, the area of the Belarusian nuclear power plant in the pre-operational period, the area of the floating nuclear power plant "Akademik Lomonosov" and the publicly accessible territory of control area of the Mayak Production Association. Such a pooling of efforts allows for the formation of new ways of obtaining reliable information for any interested public. The results of special studies characterizing the radioecological situation in the surveyed territories are presented.

Excisional biopsy and radiotherapy for management of an olfactory neuroblastoma in an axolotl (Ambystoma mexicanum)

CASE DESCRIPTION A 4-year-old sexually intact male leucistic axolotl (Ambystoma mexicanum) was presented with a 2-week history of dysrexia and difficulty swallowing. CLINICAL FINDINGS Physical examination revealed a 1-cm-diameter intraoral mass on the rostral aspect of the palate and swelling of the left nasal fossa. Local invasion into the left nasal fossa was suspected during oral examination. The lesion was marginally excised, and an incompletely excised olfactory neuroblastoma was diagnosed histologically. Five weeks later, physical examination revealed persistent erythema, delayed healing of the rostral portion of the palate, and a mild facial deformity associated with a white mass in the nasal cavity. TREATMENT AND OUTCOME 6 weeks after excision, adjuvant electron (6-MeV) beam radiotherapy was initiated for treatment of the incompletely excised olfactory neuroblastoma and likely presence of a recurrent mass. The protocol consisted of 4 weekly fractions of 8 Gy each (total, 32 Gy) with the axolotl under anesthesia. No acute adverse radiation effects were noted following radiotherapy. The oral erythema resolved after the third session. No recurrence was observed 2 months after treatment, and the owners reported no abnormal signs at home. The axolotl died 3.5 months after radiotherapy was completed (8 months after marginal excision of the tumor) secondary to an environmental management failure. Postmortem histologic evaluation showed no evidence of neoplasia. CLINICAL RELEVANCE In axolotls, olfactory neuroblastoma should be considered in the differential diagnosis of intraoral palatal masses. This report describes the first application of radiotherapy for treatment of an olfactory neuroblastoma in an axolotl.

Synchrotron FTIR Microspectroscopy Investigations on Biochemical Changes Occurring in Human Cells Exposed to Proton Beams

Fourier transform infrared microspectroscopy using a synchrotron radiation source (SR-μFTIR) has great potential in the study of the ionizing radiation effects of human cells by analyzing the biochemical changes occurring in cell components. SR-μFTIR spectroscopy has been usefully employed in recent years in some seminal work devoted to shedding light on processes occurring in cells treated by hadron therapy, that is, radiotherapy with charged heavy particles (mainly protons and carbon ions), which is gaining popularity as a cancer treatment modality. These studies are particularly useful for increasing the effectiveness of radiotherapy cancer treatments with charged particles that can offer significant progress in the treatment of deep-seated and/or radioresistant tumors. In this paper, we present a concise revision of these studies together with the basic principles of μFTIR spectroscopy and a brief presentation of the main characteristics of infrared SR sources. From the analysis of the literature regarding the SR-μFTIR spectroscopy investigation on human cells exposed to proton beams, it is clearly shown that changes in DNA, protein, and lipid cell components are evident. In addition, this review points out that the potential offered by SR-μFTIR in investigating the effects induced by charged particle irradiation have not been completely explored. This is a crucial point for the continued improvement of hadron therapy strategies.

CHARGE DISTRIBUTION IN THE AlO - SiO SYSTEM EXPOSED TO IONIZING RADIATION

Полупроводниковые МДП (металл - диэлектрик - полупроводник) структуры являются ключевыми элементами современной электронной техники, в том числе устройств работающих в условиях воздействия проникающих излучений. Одним из возможных подходов к уменьшению радиационных эффектов в МДП структурах является использование диэлектриков, которые уменьшают генерацию и накопление избыточного пространственного заряда в объеме диэлектрика. В работе исследована система диэлектриков AlO - SiO. Исследование показывает пригодность использования МДП структур, на основе системы диэлектриков, для формирования приборов с высокой радиационной стойкостью. Нанесение слоя AlO поверх слоя SiO улучшает рабочие характеристики МДП структур за счет повышения однородности параметров. Основной эффект влияния слоя AlO на параметры структур заключается в уменьшении механических напряжений на границе SiO-подложка. Захват ловушками электронов в AlO, компенсирует заряд захваченных дырок в AlO, и снижает паразитный ток через AlO. Metal-insulator-semiconductor (MIS) structures are key elements of modern electronic technology, including devices operating under conditions of exposure to penetrating radiation. One of the possible approaches to reducing radiation effects in MIS structures is the use of dielectrics, which reduce the generation and accumulation of excess space charge in the bulk of the dielectric. We investigated the system of dielectrics AlO - SiO. The study shows the suitability of using MIS structures based on a system of dielectrics for formation of devices with high radiation resistance. Applying a AlO layer on top of the SiO layer improves the performance of MIS structures by increasing the uniformity of parameters. The main effect of the influence of the AlO layer on the parameters of the structures is to reduce the mechanical stresses at the interface SiO -substrate. The trapping of electrons in AlO, compensates for the charge of the trapped holes in SiO, and reduces the parasitic current through AlO.