Desiccation-tolerant plants are able to withstand dehydration and resume normal metabolic functions upon rehydration. These plants can be dehydrated until their cytoplasm enters a ‘glassy state’ in which molecular mobility is severely reduced. In desiccation-tolerant seeds, longevity can be enhanced by drying and lowering storage temperature. In these conditions, they still deteriorate slowly, but it is not known if deteriorative processes include enzyme activity. The storage stability of photosynthetic organisms is less studied, and no reports are available on the glassy state in photosynthetic tissues. Here, the desiccation-tolerant moss Syntrichia ruralis was dehydrated at either 75% or <5% relative humidity, resulting in slow (SD) or rapid desiccation (RD), respectively, and different residual water content of the desiccated tissues. The molecular mobility within dry mosses was assessed through dynamic mechanical thermal analysis, showing that at room temperature only rapidly desiccated samples entered the glassy state, whereas slowly desiccated samples were in a ‘rubbery’ state. Violaxanthin cycle activity, accumulation of plastoglobules, and reorganization of thylakoids were observed upon SD, but not upon RD. Violaxanthin cycle activity critically depends on the activity of violaxanthin de-epoxidase (VDE). Hence, it is proposed that enzymatic activity occurred in the rubbery state (after SD), and that in the glassy state (after RD) no VDE activity was possible. Furthermore, evidence is provided that zeaxanthin has some role in recovery apparently independent of its role in non-photochemical quenching of chlorophyll fluorescence.
Part distortion is a critical issue during Additive Manufacturing (AM) of metallic parts since it prevents this technology from being implemented at industrial level. To this regard, distortion prediction even from design stage has become crucial. Actually, numerical modelling methodologies play an important role here. Different modelling approaches have been developed but one of the most computationally efficient methodology to predict distortion is the so called inherent strain method. In this work an empirical methodology to determine inherent strains is presented. This is the input data in simplified Finite Element (FE) models in order to predict distortion and residual stress fields. These inherent strains are calculated considering layer lumping strategies that might be adopted in the numerical model as well. The procedure has been developed and validated using the wellknown twin-cantilever beam structure. Ti-6Al-4V beams have been manufactured by LPBF technology following different scanning strategies. Distortion after support removal has been measured in order to be compared against numerical results. The methodology has been applied at coupon level giving accurate results and providing a preliminary validation.
Cadmium (Cd), an environmental pollutant, has been shown to be highly toxic to both humans and animals. Its widespread industrial use has led to its accumulation in the environment. Cd has been shown to target multiple organs following acute intoxication, causing nephrotoxicity, immunotoxicity, osteotoxicity, and reproductive toxicity. Cd can cross the placental barrier and cause a wide range of defects during fetal development. The current study was aimed to assess the effect of Cd on the female reproductive system. Female rats were exposed to Cd [50/200 ppm] from embryonic day 9 to 21 through drinking water. Serum steroid hormone concentrations, hematological parameters, antioxidant enzyme levels, and ovarian histopathology were described. Water consumption, gravid uterine/body weight decreased in both the doses of Cd-treated dams. The hematological parameters analyzed in rat pups showed a significant reduction in both doses of Cd studied, while hemoglobin showed a significant reduction in 200 ppm Cd treatment alone. MCHC levels did not show any variation in 50 ppm Cd treatment, while 200 ppm Cd treatment significantly increased. Specific activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, and serum testosterone, estradiol, and progesterone were significantly decreased. The levels of hydrogen peroxide and lipid peroxidation were increased in 50 and 200 ppm Cd-treated rats. These changes were accompanied with disrupted ovarian histoarchitecture, an extended estrous cycle, and delayed pubertal onset in Cd-treated rats. The data generated from the present study suggest that gestational Cd treatment induces ovarian toxicity and reproductive dysfunction through increased oxidative stress.
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