On‐the‐Spot Immobilization of Quantum Dots,Graphene Oxide,and Proteins via Hydrophobins

Class I hydrophobin Vmh2, a peculiar surface active and versatile fungal protein, is known to self‐assemble into chemically stable amphiphilic films, to be able to change wettability of surfaces, and to strongly adsorb other proteins. Herein, a fast, highly homogeneous and efficient glass functionalization by spontaneous self‐assembling of Vmh2 at liquid–solid interfaces is achieved (in 2 min). The Vmh2‐coated glass slides are proven to immobilize not only proteins but also nanomaterials such as graphene oxide (GO) and quantum dots (QDs). As models, bovine serum albumin labeled with Alexa 555 fluorophore, anti‐immunoglobulin G antibodies, and cadmium telluride QDs are patterned in a microarray fashion in order to demonstrate functionality, reproducibility, and versatility of the proposed substrate. Additionally, a GO layer is effectively and homogeneously self‐assembled onto the studied functionalized surface. This approach offers a quick and simple alternative to immobilize nanomaterials and proteins, which is appealing for new bioanalytical and nanobioenabled applications.     

Adenocarcinoma of the gastric cardia

Although adenocarcinoma of the stomach has decreased in incidence over the past several decades, cancer of the gastric cardia has increased rapidly over this time frame. There are several differences between adenocarcinoma of the cardia and distal stomach with respect to epidemiology, risk factors, and prognosis. In addition, recent data raise questions with regard to possible associations of cardia cancer with Barrett's esophagus, intestinal metaplasia of the cardia, and Helicobacter pylori. This article will review the current literature with regard to this important tumor and explore these potential disease associations.     

Reduction kinetics of Fe<Subscript>2</Subscript>MoO<Subscript>4</Subscript> fine powder by hydrogen in a fluidized bed

Iron molybdate (Fe₂MoO₄) powders with an average particle size of 100 μm were reduced by hydrogen using a fluidized-bed batch reactor in the temperature range of 923 to 1173 K. The extent of the reaction was followed as a function of time by gas chromatography. The fluidizing-gas velocity was set at about 1.5 times the minimum fluidization velocity. The ratio of the height of the static bed to its diameter is about 1. Under the prevailing experimental conditions, it was found that the chemical reaction was the rate-controlling factor. The activation energy for this process was 158±17 kJ/mol. The crystal size of the Fe₂Mo powder produced at lower temperatures was in the nanometer range, indicating the possibility of mass production of alloys and intermetallics in the nanorange, using a fluidized bed.     

HIV training and perceived competence among doctoral students in psychology.

A training-needs assessment was conducted at California School of Professional Psychology, Berkeley/Alameda, on students' beliefs about clinical competence, past training in HIV issues, and future training needs at the school. They perceived themselves to be somewhat competent in providing clinical services to HIV patients and members of groups at high risk for HIV. A modest correlation was found between the students' total HIV training and perceived competence, but none was found between the multicultural emphasis in HIV education and their perceived competence. These findings suggest an ethical dilemma surrounding inadequately trained psychologists providing services to multicultural populations. Ethical issues concerning training standards and criteria for clinical competency are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A protein required for secretion of cholera toxin through the outer membrane of Vibrio cholerae

Calcitonin, the serum calcium-lowering hormone, has been used in the treatment of hypercalcemia of malignancy and postmenopausal osteoporosis in humans for several years without any adverse effects. Recent studies in rats have indicated that calcitonin may be associated with morphologic effects on the pituitary. A large study was performed on 2 strains of rats, Sprague-Dawley (SD) and Fischer-344 (F-344), with 2 types of calcitonin, salmon-derived (sCT) and porcine-derived (pCT) calcitonin to evaluate possible effects on the pituitary. Sixteen groups of 42 male and 42 female SD or F-344 rats were given 0 (vehicle control), 1.25, 5.0, or 80.0 IU/kg/day of sCT or pCT, once daily, subcutaneously, for 1 yr. An increased incidence of adenomas of the adenohypophysis was observed in male SD rats at all dose levels of sCT, female SD rats given 80 IU/kg/day of sCT, male SD rats at the high dose level of pCT, and male F-344 rats at the high dose level of sCT. Also, an increased incidence of total proliferative lesions, due mostly to an increased incidence of focal hyperplasia of the pars distalis, occurred in female F-344 rats given the high dose of sCT. These pituitary proliferations were histologically similar to those that occur spontaneously, and the incidences observed were comparable to those that could occur in rats on 2-yr or lifetime studies, indicating that the injection of calcitonin had decreased the latency period.     

A multiple-switch high-voltage DC-DC converter

Series connection of power devices has evolved into a mature technique and is widely applied in HV DC power systems. Static and dynamic voltage balance is ensured by shunting individual devices with dissipative snubbers. The snubber losses become pronounced for increased operating frequencies and adversely affect power density. Capacitive snubbers do not exhibit these disadvantages, but they require a zero-voltage switching mode. Super-resonant power converters facilitate the principle of zero-voltage switching. A high-voltage DC-DC power converter with multiple series-connected devices is proposed. It allows the application of nondissipating snubbers to assist the voltage sharing between the multiple series-connected devices and lowers turnoff losses. Simulation results obtained with a circuit simulator are validated in an experimental power converter operating with two series-connected devices. The behavior of the series connection is examined for MOSFETs and IGBTs by both experimental work with a 2 kW prototype and computer simulation. Applications can be found in traction and heavy industry, where the soft-switching power converter is directly powered from a high-voltage source