Prospects of the use of beta-carotene enriched food products in the prevention and therapy of radiation injuries]

Radio-protective effectiveness of short-term (19 and 4 h before, 4 and 24 h after irradiation), long-term (3 times/week during 30 days after irradiation) and delayed (1 or 2 days after irradiation) enrichment with crystallized beta-carotene, in single doses of 0.1, 1.0 or 5.0 mg was evaluated in experimental acute external gamma-irradiation (0.029 Gy/sec) within the range of absorbed doses 9--6 Gy. The results obtained have permitted the authors to recommend the ration enriched with carotinoid for prevention and therapy of acute radiation injuries.     

ILB®, a Low Molecular Weight Dextran Sulphate,Restores Glutamate Homeostasis,Amino Acid Metabolism and Neurocognitive Functions in a Rat Model of Severe Traumatic Brain Injury

In a previous study, we found that administration of ILB^®, a new low molecular weight dextran sulphate, significantly improved mitochondrial functions and energy metabolism, as well as decreased oxidative/nitrosative stress, of brain tissue of rats exposed to severe traumatic brain injury (sTBI), induced by the closed-head weight-drop model of diffused TBI. Using aliquots of deproteinized brain tissue of the same animals of this former study, we here determined the concentrations of 24 amino acids of control rats, untreated sTBI rats (sacrificed at 2 and 7 days post-injury) and sTBI rats receiving a subcutaneous ILB^® administration (at the dose levels of 1, 5 and 15 mg/kg b.w.) 30 min post-impact (sacrificed at 2 and 7 days post-injury). Additionally, in a different set of experiments, new groups of control rats, untreated sTBI rats and ILB^®-treated rats (administered 30 min after sTBI at the dose levels of 1 or 5 mg/kg b.w.) were studied for their neurocognitive functions (anxiety, locomotor capacities, short- and long-term memory) at 7 days after the induction of sTBI. Compared to untreated sTBI animals, ILB^® significantly decreased whole brain glutamate (normalizing the glutamate/glutamine ratio), glycine, serine and γ-aminobutyric acid. Furthermore, ILB^® administration restored arginine metabolism (preventing nitrosative stress), levels of amino acids involved in methylation reactions (methionine, L-cystathionine, S-adenosylhomocysteine), and N-acetylaspartate homeostasis. The macroscopic evidences of the beneficial effects on brain metabolism induced by ILB^® were the relevant improvement in neurocognitive functions of the group of animals treated with ILB^® 5 mg/kg b.w., compared to the marked cognitive decline measured in untreated sTBI animals. These results demonstrate that ILB^® administration 30 min after sTBI prevents glutamate excitotoxicity and normalizes levels of amino acids involved in crucial brain metabolic functions. The ameliorations of amino acid metabolism, mitochondrial functions and energy metabolism in ILB^®-treated rats exposed to sTBI produced significant improvement in neurocognitive functions, reinforcing the concept that ILB^® is a new effective therapeutic tool for the treatment of sTBI, worth being tested in the clinical setting.     

Localization-limited exciton oscillator strength in colloidal CdSe nanoplatelets revealed by the optically induced stark effect

2D materials are considered for applications that require strong light-matter interaction because of the apparently giant oscillator strength of the exciton tra...     

Intact and impaired mechanisms of action understanding in autism.

Typically developing children understand and predict others' behavior by extracting and processing relevant information such as the logic of their actions within the situational constraints and the intentions conveyed by their gaze direction and emotional expressions. Children with autism have difficulties understanding and predicting others' actions. With the use of eye tracking and behavioral measures, we investigated action understanding mechanisms used by 18 children with autism and a well-matched group of 18 typically developing children. Results showed that children with autism (a) consider situational constraints in order to understand the logic of an agent's action and (b) show typical usage of the agent's emotional expressions to infer his or her intentions. We found (c) subtle atypicalities in the way children with autism respond to an agent's direct gaze and (d) marked impairments in their ability to attend to and interpret referential cues such as a head turn for understanding an agent's intentions. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Light Controlled Biohybrid Microbots

Biohybrid microbots integrate biological actuators and sensors into synthetic chassis with the aim of providing the building blocks of next-generation micro-robotics. One of the main challenges is the development of self-assembled systems with consistent behavior and such that they can be controlled independently to perform complex tasks. Herein, it is shown that, using light-driven bacteria as propellers, 3D printed microbots can be steered by unbalancing light intensity over different microbot parts. An optimal feedback loop is designed in which a central computer projects onto each microbot a tailor-made light pattern, calculated from its position and orientation. In this way, multiple microbots can be independently guided through a series of spatially distributed checkpoints. By exploiting a natural light-driven proton pump, these bio-hybrid microbots are able to extract mechanical energy from light with such high efficiency that, in principle, hundreds of these systems can be controlled simultaneously with a total optical power of just a few milliwatts.     

Ice‐Assisted Synthesis of Black Phosphorus Nanosheets as a Metal‐Free Photocatalyst: 2D/2D Heterostructure for Broadband H2 Evolution

A 2D/2D heterojunction of black phosphorous (BP)/graphitic carbon nitride (g‐C₃N₄) is designed and synthesized for photocatalytic H₂ evolution. The ice‐assisted exfoliation method developed herein for preparing BP nanosheets from bulk BP, leads to high yield of few‐layer BP nanosheets (≈6 layers on average) with large lateral size at reduced duration and power for liquid exfoliation. The combination of BP with g‐C₃N₄ protects BP from oxidation and contributes to enhanced activity both under λ > 420 nm and λ > 475 nm light irradiation and to long‐term stability. The H₂ production rate of BP/g‐C₃N₄ (384.17 µmol g^?1 h^?1) is comparable to, and even surpasses that of the previously reported, precious metal‐loaded photocatalyst under λ > 420 nm light. The efficient charge transfer between BP and g‐C₃N₄ (likely due to formed N? P bonds) and broadened photon absorption (supported both experimentally and theoretically) contribute to the excellent photocatalytic performance. The possible mechanisms of H₂ evolution under various forms of light irradiation is unveiled. This work presents a novel, facile method to prepare 2D nanomaterials and provides a successful paradigm for the design of metal‐free photocatalysts with improved charge‐carrier dynamics for renewable energy conversion.     

BETaaS: A Platform for Development and Execution of Machine-to-Machine Applications in the Internet of Things

Wireless Personal Communications - The integration of everyday objects into the Internet represents the foundation of the forthcoming Internet of Things (IoT). Smart objects will be the building...     

Hybrid Photonic Nanostructures by In Vivo Incorporation of an Organic Fluorophore into Diatom Algae

Biotechnological processes harnessing living organisms' metabolism are low‐cost routes to nanostructured materials for applications in photonics, electronics, and nanomedicine. In the pursuit of photonic biohybrids, diatoms microalgae are attractive given the properties of the porous micro‐to‐nanoscale structures of the biosilica shells (frustules) they produce. The investigations have focused on in vivo incorporation of tailored molecular fluorophores into the frustules of Thalassiosira weissflogii diatoms, using a procedure that paves the way for easy biotechnological production of photonic nanostructures. The procedure ensures uniform staining of shells in the treated culture and permits the resulting biohybrid photonic nanostructures to be isolated with no damage to the dye and periodic biosilica network. Significantly, this approach ensures that light emission from the dye embedded in the isolated biohybrid silica is modulated by the silica's nanostructure, whereas no modulation of photoluminescence is observed upon grafting the fluorophore onto frustules by an in vitro approach based on surface chemistry. These results pave the way to the possibility of easy production of photonic nanostructures with tunable properties by simple feeding the diatoms algae with tailored photoactive molecules.     

Junction leakage current degradation under high temperature reverse-bias stress induced by band-defect-band tunnelling in power VDMOS

A deep analysis of the intrinsic junction and surface currents in power vertically diffused MOS devices with sub-micrometer channel length and thin gate oxide has been carried on after a typical reliability high temperature reverse bias (HTRB) stress. A reference set of gated diodes has also been examined in order to better understand the onset and evolution of post-stress leakage degradation. A comparison among complete MOSs, single body diodes and enriched diodes allows to highlight the role played by the point defectivity both at gate interface and in the bulk silicon close to the junction surface. We found that the typical interface defects involved in the leakage degradation are shallow traps and can be de-populated simply by a thermally activated mechanism. More specifically, the main degradation mechanism relies to band-defect-band tunneling localized at the surface drain/body junction where an intrinsic n-i-p region evolves due to a bird’s beak lateral profile of the body diffusion. We have demonstrated that the most important contribution to the activation of the precursor defect sites is given by the transverse electrical field that develops just below the SiO₂/Si interface within the n-i-p region during the stress.