Mixed 3D-2D Perovskite Flexible Films for the Direct Detection of 5 MeV Protons

This study reports on a novel, flexible, proton beam detector based on mixed 3D-2D perovskite films deposited by solution onto thin plastic foils. The 3D-2D mixture allows to obtain micrometer-thick and highly uniform films that constitute the detector's active layer. The devices demonstrate excellent flexibility with stable electric transport properties down to a bending radius of 3.1 mm. The detector is characterized under a 5 MeV proton beam with fluxes in the range [4.5 × 105 - 1.4 × 109 ] H+ cm-2 s-1 , exhibiting a stable response to repetitive irradiation cycles with sensitivity up to (290 ± 40) nC Gy-1 mm-3 and a limit of detection down to (72±2) µGy s-1 . The detector radiation tolerance is also assessed up to a total of 1.7 × 1012 protons impinging on the beam spot area, with a maximum variation of the detector's response of 14%.

Impact of hot environment on colostrum and milk composition

Under hot and warm environments productivity and reproduction efficiency of farm and wild animals are negatively affected. The negative effects of hot environments on animal health are responsible for the alteration of colostrum and milk production in term of quantity and quality. Colostrum and milk are nutrient-rich fluids secreted by the mammary gland of female mammals after giving birth and during growth and development of the young. Multiple factors influence the production and the composition of colostrum and milk, including species, breed, health status, feeding practices and environmental conditions. Colostrum and milk are not only a good source of macronutrients and micronutrients, but contains many biologically-active constituents. Colostrum and milk of various species differ widely in amounts and proportions of their principal constituents, especially comparing monogastric with ruminant animals because of the difference between their physiology and digestion. The interspecies variations in part reflect different adaptive strategies to environmental conditions and selective pressures of various species during the evolution. A limited number of studies documented the effects of hot condition on modification of colostrum and milk quality, in particular referred to nutrients and immunoglobulin composition, but no information are available on the effects of hot environment on nutraceutical properties and bioactive molecules content of colostrum and milk.

Insights on early response to acute heat shock of bovine mammary epithelial cells through a multimethod approach

Heat stress is a significant challenge in dairy cattle herds, affecting milk production and quality, and generating important changes at the cellular level. Most in vitro research on heat shock (HS) effects on dairy cow mammary cells was focused on medium-long-term effects. In recent years, Fourier transform-infrared (FT-IR) micro-spectroscopy has been increasingly used to study the effects of several external stresses on different cell lines, down to the level of single cellular components, such as DNA/RNA, lipids, and proteins. In this study, the possible changes at the biochemical and molecular level induced by acute (30 min-2 h) HS in bovine mammary epithelial (BME-UV1) cells were investigated. The cells were exposed to different temperatures, thermoneutral (TN, 37 °C) and HS (42 °C), and FT-IR spectra were acquired to analyse the effects of HS on biochemical characteristics of BME-UV1 cellular components (proteins, lipids, and DNA/RNA). Moreover, cell viability assay, reactive oxygen species production, and mRNA expression of heat shock proteins (HSPA1A, HSP90AA1, GRP78, GRP94) and antioxidant genes (SOD1, SOD2) by RT-qPCR were also analysed. The FT-IR results showed a change already at 30 min of HS exposure, in the content of long-chain fatty acids, which probably acted as a response to a modification of membrane fluidity in HS cells compared with TN cells. After 2 h of HS exposure, modification of DNA/RNA activity and accumulation of aggregated proteins was highlighted in HS cells. The gene expression analyses showed the overexpression of HSPA1A and HSP90AA1 starting from 30 min up to 2 h in HS cells compared with TN cells. At 2 h of HS exposure, also the overexpression of GRP94 was observed in HS cells. Acute HS did not affect cell viability, reactive oxygen species level, and SOD1 and SOD2 gene expression of BME-UV1 cells. According to the results obtained, cells initiate early defence mechanisms in case of acute HS and probably this efficient response capacity may be decisive for tolerance to heat stress of dairy cattle.

Application of a generalized additive mixed model in time series study of dairy cow behavior under hot summer conditions

This study investigated the pattern of 6 behavioral parameters in Holstein dairy cows under heat stress (HS) conditions using a generalized additive mixed model (GAMM) statistical approach, while also evaluating the effectiveness of a commercial electrolyte, osmolyte, and antioxidant blend in mitigating HS-induced adverse effects. The trial was conducted during a severe Italian summer on 84 multiparous dairy cows in the Central Italy, divided into 4 balanced groups (2 treated and 2 control) of 21 cows each. All animals received the same diet, and the treatment groups were supplemented with 3,150 g/d of the additive. Behavioral parameters, namely low activity (LA), medium activity (MA), high activity (HA), rumination time (RUM), eating time (ET), and heavy breathing (OH), were monitored using neck collar sensors. Generalized additive mixed models were used to analyze trajectory changes of these parameters over time and climatic conditions. Results indicated significant variations in only one activity parameter, with treated cows showing increased MA with rising temperature-humidity index (THI). Eating time declined with increasing HS, particularly in the treated group, suggesting potential HS relief. Rumination time decreased with increasing HS levels but increased also with milk yield and lactation stage. As expected, heavy breathing significantly increased with THI, especially beyond THI 80, and was influenced by milk yield and lactation stage but not by the treatment. The use of GAMM enhanced visualization and understanding of severe climatic conditions' effects on behavioral parameters.

Effects of milk extracellular vesicles from Holstein Friesian and Brown Swiss heat-stressed dairy cows on bovine mammary epithelial cells

The increase in ambient temperature is responsible for a behavioral, physiological, and metabolic responses known as heat stress, which affects dairy cows' general well-being, health, reproduction, and productivity. Focusing on the functioning of the mammary gland, attention has been recently paid to a new method of cell-cell communication mediated by extracellular vesicles, which with their cargo can affect the target cells' phenotypic traits, behavior, and biological functions. This study investigated whether the small extracellular vesicles (sEV) isolated from milk of heat-stressed Holstein Friesian (H) and Brown Swiss (B) cows affect the cellular response of a bovine mammary epithelial cell line (BME-UV1). To this purpose, 8 mid lactation cows, 4 of each breed fed the same diet and kept in the same barn, which experienced the same hyperthermia during a natural heat wave, were chosen to collect 2 milk different samples: under thermoneutrality (TN, d1) and under heat stress (HS, d 8) conditions. The sEV were isolated from skim milk samples through differential centrifugations, characterized for size and concentration by nanoparticle tracking analysis. Integrity of the milk sEV membranes was evaluated by transmission electron microscopy and presence of EV markers through western blotting. Then BME-UV1 cells were incubated for 24 h with different pooled milk sEVs (H-TN, H-HS, B-TN, B-HS). Cell viability and apoptosis assay, reactive oxygen species production, and mRNA expression of heat shock proteins and antioxidant genes by reverse transcription and real time PCR were determined. In vivo results showed an increase in rectal temperature and respiration rate, a reduction in milk yield both for H and B dairy cows, with a lowest decrease observed in B cows compared with H cows. In vitro results of BME-UV1 cells treated with milk sEV H-HS and B-HS showed an alteration of the cell viability and metabolic activity, by reducing or increasing reactive oxygen species accumulation, and suppressing or increasing the expression of stress-associated genes thereby modulating the response of BME-UV1 according to the animals' thermal condition and the breed. These findings indicated that the small vesicles of Brown milk triggered cellular defense against heat stress, supporting the Brown Swiss breed's thermotolerance.

Real-Time Radiation Beam Monitoring by Flexible Perovskite Thin Film Arrays

Real-time and in-line transversal monitoring of ionizing radiation beams is a crucial task for several applications which span from medical treatments to particle accelerators in high energy physics. Here a flexible and large area device based on 2D hybrid perovskite thin films (phenylethylammonium lead bromide), fabricated onto a thin flexible polyimide substrate, able to map the transversal beam profile of high energy radiation beams is reported. The performance of this novel tool is here compared with the one offered by standard commercial large-area technology, namely radiochromic sheets. The great potential of this class of devices is demonstrated by successfully mapping in real-time a 5 MeV proton beam at fluxes between 108 and 1010 H+ s-1 cm-2, confirming the capability to operate in a radiation-harsh environment without output signal saturation issues. The versatility and scalability of here proposed detecting system are demonstrated by the development of a multipixel array able to map in real-time a 40 kVp X-ray beam spot (dose rate 8 mGy s-1). Perovskite thin film-based detectors are thus assessed as a very promising class of thin, flexible devices for real-time, in-line, large-area, conformable, reusable, transparent, and low-cost transversal beam monitoring of different ionizing radiation.