Ar assisted carbidization of TiO2 (1 1 0) supported Mo nanoparticles by decomposition of C2H4

Ar⁺ assisted carbidization of Mo nanoparticles supported on TiO₂ (1 1 0) is studied by scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). In order to activate the diffusion of carbon into the bulk of Mo nanoparticles we applied Ar ions (1 keV) during the exposure of C₂H₄. XPS exhibited that the decomposition of C₂H₄ at 850 K accompanied by ion bombardment results in an almost complete carbidization of nanocrystalline Mo while this treatment performed without ion bombardment results only in the carbidization of the particle surface. The modification of the crystallinity of the Mo-carbide particles was deduced from STM measurements.     

The “root” experiment of the “cervantes” spanish soyuz mission: Cell proliferation and nucleolar activity alterations in arabidopsis roots germinated in real or simulated microgravity

In an experiment conducted in the “Cervantes” Spanish Soyuz Mission, a 10-day flight to the International Space Station, Arabidopsis seeds were germinated, seedlings grew for 4 days at 22ºC, and they were fixed in flight with paraformaldehyde. A ground 1 g control experiment was replicated, and an additional experiment in simulated microgravity, using a Random Positioning Machine, was performed in the same conditions. Structural, morphometric and immunocytochemical data were compared. Glutaraldehyde-fixed seedlings similarly grown in the Space Shuttle (STS-84 Mission) were also used for ultrastructural and morphometric studies. Seedlings grown for 4 days in real or simulated weightlessness showed a longer size than the ground 1 g control. Root meristematic cells showed an enhanced proliferating rate, but ribosome biogenesis was reduced, as inferred from the nucleolar size and from the levels of the nucleolar protein nucleolin. This could be the consequence of the acceleration of the cell cycle, with shortening of its phases. Weightlessness induces stress in the plant, influencing cellular processes decisive for development and morphogenesis. This stress may endanger the plant and would require the action of compensating specialized defence mechanisms.     

A combined optical–wireless indoor communication system

This new combined optical–wireless indoor communication system provides an economic and flexible approach for local area networks mainly in large buildings or in a group of several buildings. The radiation from the radio base stations of mobile networks cannot penetrate into large buildings completely. That problem is more serious at higher frequencies. The present approach offers a good solution to this problem. In this approach the wireless communication serves small picocells which are interconnected by an optical backbone. The performance of the system is enhanced by assigning a specific radio frequency for each picocell which enables the transmission of the wireless channels without altering their modulation formats. This method allows for a simple, and low-cost indoor communication system.     

Comparison of deposition models for a TEOS LPCVD process

We present a comparison of models describing the pyrolytic deposition of SiO₂ with a low pressure chemical vapor deposition process. In order to meet industrial simulation requirements, e.g. accuracy and fast delivery of results, we present an overview of established and new models, their use within TCAD applications, and their best results which have been obtained by calibrations according to SEM measurements.     

Two-mode state reconstruction using photon chopping

Abstract

The reconstruction of the complete quantum state of a pure-state two-mode field is shown to be possible by the photon-chopping method, that is, by spreading the signal with balanced multiports over an array of detectors and by measuring coincidences. In particular, correlations between the two modes can be detected with high efficiency.     

Synthetic and Biological Studies of Sesquiterpene Polygodial: Activity of 9‐Epipolygodial against Drug‐Resistant Cancer Cells

Polygodial, a terpenoid dialdehyde isolated from Polygonum hydropiper L., is a known agonist of the transient receptor potential vanilloid 1 (TRPV1). In this investigation a series of polygodial analogues were prepared and investigated for TRPV1‐agonist and anticancer activities. These experiments led to the identification of 9‐epipolygodial, which has antiproliferative potency significantly exceeding that of polygodial. 9‐Epipolygodial was found to maintain potency against apoptosis‐resistant cancer cells as well as those displaying the multidrug‐resistant (MDR) phenotype. In addition, the chemical feasibility for the previously proposed mechanism of action of polygodial, involving the formation of a Paal–Knorr pyrrole with a lysine residue on the target protein, was demonstrated by the synthesis of a stable polygodial pyrrole derivative. These studies reveal rich chemical and biological properties associated with polygodial and its direct derivatives. These compounds should inspire further work in this area aimed at the development of new pharmacological agents, or the exploration of novel mechanisms of covalent modification of biological molecules with natural products.     

Effects of nicotine deprivation on alcohol-related information processing and drinking behavior.

This study examined the influence of smoking cues and nicotine deprivation on responses to alcohol among hazardous drinkers. Fifty-six daily smoking, hazardous drinkers were exposed to either smoking cues or control cues after either 6 hr of nicotine deprivation or no deprivation. Urges to drink alcohol, alcohol-related cognitive processing, and alcohol consumption were assessed after cue exposure. Results indicated that nicotine deprivation increased urges to drink, the accessibility of alcohol outcome expectancies, and the volume of alcohol consumed. There was little influence of the smoking cue manipulation on these processes. Implications for understanding the mechanisms underlying alcohol–tobacco interactions are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Glial-Neuronal Interactions in Pathogenesis and Treatment of Spinal Cord Injury

Traumatic spinal cord injury (SCI) elicits an acute inflammatory response which comprises numerous cell populations. It is driven by the immediate response of macrophages and microglia, which triggers activation of genes responsible for the dysregulated microenvironment within the lesion site and in the spinal cord parenchyma immediately adjacent to the lesion. Recently published data indicate that microglia induces astrocyte activation and determines the fate of astrocytes. Conversely, astrocytes have the potency to trigger microglial activation and control their cellular functions. Here we review current information about the release of diverse signaling molecules (pro-inflammatory vs. anti-inflammatory) in individual cell phenotypes (microglia, astrocytes, blood inflammatory cells) in acute and subacute SCI stages, and how they contribute to delayed neuronal death in the surrounding spinal cord tissue which is spared and functional but reactive. In addition, temporal correlation in progressive degeneration of neurons and astrocytes and their functional interactions after SCI are discussed. Finally, the review highlights the time-dependent transformation of reactive microglia and astrocytes into their neuroprotective phenotypes (M2a, M2c and A2) which are crucial for spontaneous post-SCI locomotor recovery. We also provide suggestions on how to modulate the inflammation and discuss key therapeutic approaches leading to better functional outcome after SCI.