Silicon nanowire synthesis by a vapor-liquid-solid approach

Synthesis of silicon nanowires is studied by using a vapor-liquid-solid growth technique. Silicon tetrachloride reduction with hydrogen in the gas phase is used with gold serving as catalyst to facilitate growth. Only a narrow set of conditions of SiCl4 concentration and temperature yield straight nanowires. High concentrations and temperatures generally result in particulates, catalyst coverage and deactivation, and coatinglike materials.     

The Austria-Czech Republic co-operation in the field of radiation-emergency preparedness

An overview on the long-term information exchange and co-operation between Austria and the Czech Republic in the field of radiation emergency preparedness and evaluation of radiological consequences of NPP accidents is provided. Initiated by the 'Melk Protocol' between the Czech and Austrian governments in December 2000 and its follow-up activities, the information exchange and co-operation between the Czech Republic and Austria in the field of radiation-emergency preparedness have been extended. Among others, a Working Group to compare radiological consequences of Beyond Design Basis Accident with a detailed inter-comparison program concerning atmospheric dispersion models, dose assessment methods and counter- measures was established. Based on this experience, an area for future co-operation in the field of emergency preparedness and information exchange between the Czech Republic and Austria is discussed.     

Synthesis and application of fluorescent ras proteins for live-cell imaging

Semisynthetic Ras proteins are efficient probes for cell-biology experiments. With a Bodipy FL fluorophore introduced at an appropriate site on the Ras peptide by solid-phase synthesis, the resulting Ras chimera is processed by the cellular machinery and the intracellular localization of the protein can then be visualized by means of confocal laser fluorescence microscopy at relatively low concentrations. The absence of a large N-terminal protein tag overcomes possible interferences in the interaction with cellular partner proteins. The fluorescence emission from Bodipy FL is continuous and disappears only after irreversible bleaching. These characteristics make Ras proteins with nonprotein fluorophores suitable for biophysical analysis. The easy accessibility of the lipopeptide moiety by chemical synthesis opens up numerous options for further biological investigations.     

Inhibitors of the epidermal growth factor receptor in apple juice extract

The polyphenol-rich extract of a consumer-relevant apple juice blend was found to potently inhibit the growth of the human colon cancer cell line HT29 in vitro. The epidermal growth factor receptor (EGFR) and its subsequent signaling cascade play an important role in the regulation of cell proliferation in HT29 cells. The protein tyrosine kinase activity of an EGFR preparation was effectively inhibited by the polyphenol-rich apple juice extract. Treatment of intact cells with this extract resulted in the suppression of the subsequent mitogen-activated protein kinase cascade. Amongst the so far identified apple juice constituents, the proanthocyanidins B1 and B2 as well as quercetin-3-glc (isoquercitrin) and quercetin-3-gal (hyperoside) were found to possess substantial EGFR-inhibitory properties. However, as to be expected from the final concentration of these potential EGFR inhibitors in the original polyphenol-rich extract, a synthetic mixture of the apple juice constituents identified and available so far, including both proanthocyanidins and the quercetin glycosides, showed only marginal inhibitory effects on the EGFR. These results permit the assumption that yet unknown constituents contribute substantially to the potent EGFR-inhibitory properties of polyphenol-rich apple juice extract. In summary, the polyphenol composition of apple juice possesses promising growth-inhibitory properties, affecting proliferation-associated signaling cascades in colon tumor cells.     

Characterization of ultrashort pulse formation in passivelymode-locked fiber lasers

Pulse formation in an all-solid-state passively mode-locked neodymium glass fiber laser is investigated by employing characterization techniques in the time, optical, and radio-frequency domains. The pulses are generated by a combination of passive amplitude modulation arising from nonlinear polarization evolution and passive frequency modulation due to quasi-soliton-like pulse shaping. Several distinct operation modes for ultrashort pulse generation are described and pulses as short as 38 fs are directly generated in the cavity     

Development and implementation of a perioperative autologous service program

Several months after we initiated our PAS program, the AABB scrutinized our policy and procedure manual. At the same time, the JCAHO conducted an inspection of our blood bank and its standards. Both reviews were positive, which provided all of us involved in the PAS program with a tremendous sense of accomplishment. Each PAS team member played a significant role in the development and implementation of our PAS program. Thanks to the energy, enthusiasm, and support of perioperative nurses, surgeons, and hospital administrators, our PAS program has evolved into a high quality, efficient alternative to homologous blood transfusions in the perioperative setting.     

The importance of political devolution for professional psychology.

Recent years have witnessed a major transformation in public policy that has significant ramifications for health care professions. Through a process known as devolution, the federal government has shifted major amounts of money and decision-making authority to state governments. In health care, this shift places resources closer to the local levels, where practitioners have opportunities to influence their use. Varying perspectives on devolution are presented by 4 experts in state and local government to suggest some possible ways that professional psychology can become more involved in this process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of a social companion on the ultrasonic vocalizations and contact responses of 3-day-old rat pups.

Rat pups that are isolated in a novel environment emit ultrasonic calls. Vocalization in 3-day-old pups has been thought to be predominantly under thermal control (J. T. Allin and E. M. Banks, 1971). By the 2nd wk of life, ultrasonic vocalizations are reduced when pups are tested in the company of a single anesthetized littermate (S. E. Carden and M. A. Hofer, 1990; Hofer and H. Shair, 1978). In the present study, it was demonstrated that the vocalization rate of 3-day-old pups is also decreased when an anesthetized littermate is present in the isolation chamber. To determine whether this quieting was a function of the body heat of the companion, in a 2nd experiment, the axillary temperature of the companion was lowered until it was the same as the ambient temperature of the test chamber, 22°C. In the presence of a cool companion, ultrasonic vocalizations were also reduced. For the last experiment, a textured plastic surrogate was substituted for the littermate. Calls were not diminished in the presence of the surrogate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spectroscopic studies of the chemical properties of thin metal films on poly(ether imide)

X-ray photoelectron spectroscopy studies were conducted on thin films of copper and nichrome (80:20 Ni:Cr) on neat poly(ether imide) (PEI) substrates. Evaporated copper thin films reacted mildly with PEI and formed metal carbides and oxides at the copper - PEI interface. In contrast, the chromium component of the nichrome alloy reacted strongly with PEI to generate a distribution of chromium oxides, nitrides, and carbides. However, the nickel component of nichrome exhibited little reactivity with the resin. Differences in the reactivities of metal thin films on PEI can be correlated to the heats of formation of the corresponding metal carbides, oxides, and nitrides. This information provides key insights into metals for use as adhesion promoters on printed circuit boards and molded circuits containing PEI.