The action modes of an extracellular beta-1,3-glucanase isolated from Bacillus clausii NM-1 on beta-1,3-glucooligosaccharides

The mode of action of an extracellular -1,3-glucanase from Bacillus clausii NM-1 on beta-1,3-3glucooligosaccharides and their alditols was studied. The enzyme could not hydrolyze laminaribiose or laminaritriose. beta-1,3-Glucooligosaccharides higher than laminarihexaose were rapidly hydrolyzed, while laminaritetraose was slowly hydrolyzed. The k(cat)/K(m) ratios for a series of beta-1,3-glucooligosaccharides from laminaritetraose to laminariheptaose showed that the substrate binding site of the enzyme covered a wide range of beta-1,3-glucooligosaccharides having six glucose residues. The action pattern of the enzyme on the alditols corresponding to each laminarioligosaccharide suggested that the catalytic site of the enzyme existed between the third and fourth glucose residue from the non-reducing terminal. The value of k(cat)/K(m) also suggested that the sixth binding position contributed to the catalytic efficiency and stability.     

Mechanism of self-association and filament capping by flagellar HAP2

HAP2 forms a capping structure, which binds very tightly to the distal end of flagellar filaments and still allows insertion of flagellin subunits below the cap by an unknown mechanism. Terminal regions of HAP2 from Salmonella typhimurium were found to be quickly degraded by various proteases, indicating that HAP2 also possesses disordered terminal regions like other axial proteins of bacterial flagellum. Removal of these portions by trypsin results in a fragment of 40 kDa (HP40), which lacks 42 NH2-terminal and 51 COOH-terminal residues. HAP2 in solution readily associates into a decameric structure without any significant population of intermediate oligomeric forms. The HP40 fragments, however, do not form decamers, while they can assemble into pentamers, as revealed by chemical cross-linking and analytical ultracentrifugation. Decameric HAP2 also dissociates into pentamers and smaller oligomers upon a heat induced conformational transition around 36 degreesC. While the highly mobile terminal regions are immobilized in decameric HAP2 complexes, they are still largely disordered in the pentameric state. These results demonstrate that the intersubunit interactions within the pentamers are mainly through the HP40 portions, whereas the terminal regions are responsible for association of pentamers into decameric complexes. Several observations indicate that HAP2 performs its capping function as a pentamer. We suggest that binding of the pentameric HAP2 cap to the filament is mediated by the highly flexible terminal regions. Indeed, HP40 fragments are unable to cap the end of filaments, while removal of about 30 residues from both terminal regions of HAP2 results in a highly reduced capping ability. A model is presented to explain the molecular mechanism of capping, in which conformational entropy in the disordered terminal regions moderates the otherwise too tight HAP2-filament interactions to allow insertion of flagellin subunits below the cap.     

Carcinosarcoma of the esophagus: three cases with immunohistological examination

Carcinosarcoma of the esophagus is a rare malignant tumor with both carcinomatous and sarcomatous components. We present 3 cases of carcinosarcoma of the esophagus and discuss the histogenesis of the tumors. We performed immunohistochemical studies using various antibodies: anti-cytokeratin, anti-vimentin, anti-smooth muscle actin, anti-p53, and MIB 1 reacting with Ki-67 nuclear antigen.     

Direct coupling of VCSELs to plastic optical fibers using guideholes patterned in a thick photoresist

In this letter, we report a simple passive alignment method to couple plastic optical fibers (POFs) to vertical-cavity surface-emitting lasers (VCSELs) for use in parallel optical interconnects. Polymer guide holes were fabricated directly on the top of VCSELs by means of standard photolithography using SU-8 epoxy-based thick photoresist. Perfluorinated graded-index POFs were inserted and fixed in the guide holes to provide butt-coupled packaging modules. For a VCSEL of 15-μm diameter and a POF of 124-μm core diameter, coupling efficiencies were obtained between about 80% and 50%, depending on drive current. The standard deviation of the efficiency at a drive current of 10 mA was 5.9% for a 1 × 5 array     

Influence of nonverbal communication and rater proximity on impressions and decisions in simulated employment interviews.

Examined the influences of nonverbal communication and different methods of assessing a job applicant. 72 female Ss saw either an immediate or nonimmediate applicant while serving as an interviewer, observer, or television observer. (Immediacy was manipulated through several nonverbal channels of communication: eye contact, smiling, posture, interpersonal distance, and body orientation.) Both observers were yoked to the interviewer. Results clearly indicate that nonverbal communication had a significant effect on interview impressions and subsequent decisions. Further, several self-report measures suggest different degrees of involvement as a function of the rater's proximity. Implications for future research and novel interviewing techniques are discussed. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fel d 1 peptides: effect on skin tests and cytokine synthesis in cat-allergic human subjects

We tested peptide immunotherapy in cat-allergic humans, using a formation of two synthetic peptides, IPC-1 and IPC-2, each of which is 27 amino acids long and contains T cell-reactive regions of Fel d 1, the major cat allergen. In this exploratory, randomized, double-blind, parallel-group study, 42 subjects received s.c. injections of treatment peptides 250 micrograms or placebo weekly for four consecutive weeks. Changes in immediate- and late-phase skin test reactivity, and in antigen-driven cytokine synthesis were assessed. Epicutaneous (end-point titration) and intradermal tests were performed with cat extract (ALK SQ Cat Hair) containing Fel d 1, before the first injection, then 2, 6 and 24 weeks after the fourth and last injection of peptides or placebo. IL-4, IL-10 and IFN-gamma expression by circulating peripheral blood mononuclear cells (PBMC) in response to cat extract was measured using short-term bulk culture of PBMC and short-term limiting dilution analysis. Subjects who received peptide immunotherapy did not tolerate significantly more cat extract containing Fel d 1 in the skin tests 2, 6 or 24 weeks after the last injection than they did at baseline, and their late-phase responses did not decrease significantly compared to baseline. Substantial IL-4, IL-10 and IFN-gamma responses were observed following primary culture of cat antigen-stimulated PBMC; however, the intensity of cytokine synthesis and the IFN-gamma: IL-4 ratio were unchanged in peptide- and placebo-treated groups 6 and 24 weeks after the last injection. A few hours after the injections, subjects receiving peptides reported more allergic rhinitis and asthma symptoms and more pruritus than those receiving placebo. We conclude that under the conditions tested, peptide immunotherapy did not reduce immediate- or late-phase skin reactivity to cat extract containing Fel d 1 or modify cat antigen-specific cytokine production significantly.     

Surface-emitting device with embedded circular grating coupler for possible application to optoelectronic integrated devices

A surface-emitting device with an embedded circular grating coupler is developed. A uniform grating coupler with 0.4-/spl mu/m pitch and 0.15-/spl mu/m depth is fabricated by electron beam lithography and reactive ion etching. The grating is well embedded by an overgrown layer. It is shown that the lasing oscillation is successfully achieved up to the measured temperature of 196 K where the absorption loss at the grating coupler is well suppressed, and a stable single-longitudinal-mode oscillation is obtained.     

Distributed feedback surface-emitting laser with air/semiconductor gratings embedded by mass-transport assisted wafer fusion technique

We report on a distributed feedback InGaAsP MQW laser with air/semiconductor gratings embedded by wafer-fusion technique with the assistance of mass-transport phenomenon for the first time. The air/semiconductor gratings with 0.4-/spl mu/m period and 0.2-/spl mu/m depth are successfully fabricated inside the device, and a single longitudinal mode oscillation at about 1.28 /spl mu/m is demonstrated under pulsed condition at room temperature. The threshold current density is estimated to be about 1.4 kA/cm/sup 2/. It is also shown that the device has a surface-emitting function since it has a low loss multiquantum-well waveguide with grating output coupler.     

Semiconductor three-dimensional and two-dimensional photoniccrystals and devices

Semiconductor three-dimensional (3-D) and two-dimensional (2-D) photonic crystals and their effects on the control of photons are investigated for possible applications to optical chip and functional devices. First we review our approaches creating full 3-D photonic bandgap crystals at near-infrared wavelengths, and also functional devices based on 2-D photonic crystals where the focus is on surface-emitting-type channel-drop filtering devices utilizing single defects in 2-D photonic crystal slabs. Then, we describe the recent progress on 3- and 2-D crystals. On 3-D crystals, the effect of the introduction of a light emitter into the 3-D photonic crystal is investigated, and the design of a single defect cavity is performed. On the 2-D photonic crystals, the photonic states are investigated from the perspective of their polarization properties