An investigation of the effect of high pressure on the structure of siliceous zeolite Y

The IR spectra of siliceous zeolite Y were measured as a function of external pressure. The results indicate that the siliceous zeolite Y undergoes pressure-induced amorphization. This phase transformation seems to be driven by the severe distortion of double six-membered rings joining the adjacent sodalite cages to form the zeolitic lattice. Unlike hydrated zeolite NaY and structurally related zeolite NaA, the amorphization is irreversible due to the lack of hydrated charge balancing cations.     

Antibody library selection by the {beta}-lactamase protein fragment complementation assay

Protein fragment complementation assay (PCA) is based on the interaction between two protein partners (e.g. target antigen and antibody), which are genetically fused to the two halves of a dissected marker protein. Binding of the two partners reassembles the marker protein and hence reconstitutes its activity. In this work we have developed the first application of beta-lactamase-based PCA for the isolation of single chain Fv fragments (scFvs) binding to the human receptor RON from a na?ve library. Specific scFvs with the ability to immunoprecipitate could be isolated after a single round of PCA selection from an scFv repertoire previously pre-selected by phage display. Furthermore, the PCA was used to successfully map the epitopes recognized by the selected scFvs by screening them against a small library of random RON fragments.     

Building the boundaries of a science: First representations of Italian social psychology between 1875 and 1954.

The present study embraces the critical traditions of “New History” and of social representations theory articulated with the mainstream historiographical tradition of a bibliometric approach. The historical analysis deals with the early representations of Italian social psychology articulated and disseminated by some of the main Italian scientific-cultural and philosophical journals. We examined seven journals published between 1875 and 1954, and gathered 2,030 texts dealing with the various forms of social and collective psychology. We have applied a grid of content analysis whose data have been transcribed to a numerical file. At the same time, we have created a textual file containing the titles of the contributions as well as the names of the authors and scholars reviewed. The two files have been processed by SPAD-T for a correspondence analysis in which both lexical data and category variables have been considered as active variables. Through the scree-test, two factors that explain 18.90% of the variance have been singled out. Their combination has produced a factorial plan able to highlight three distinct areas differently characterized from journals and years. The results are also discussed with regard to the contextual historical frame. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Aging behavior of Y-TZP with bioglass addition and its impact on the flexural strength and osteoblastic cell response

Y-TZP containing Ca₂P₂O₇ are promising bioceramics with potential applications in dental implants and dentistry. These ceramics were developed by the introduction of a refractory sol-gel derived CaO-P₂O₅-SiO₂ bioglass into Y-TZP; Ca₂P₂O₇, and ZrSiO₄ phases were formed in situ after sintering. The aging process of Y-TZP with different glass additions was studied. The effect of glass addition on the flexural strength and osteoblastic cell response of non-aged and aged Y-TZP was investigated. Y-TZP exhibited the most pronounced tetragonal (t) to monoclinic (m) transformation of zirconia (ZrO₂) during aging; the addition of glass contents between 5 and 20 vol% improved the aging resistant of Y-TZP. Y-TZP flexural strength markedly decreased with increasing aging time; in contrast, the ceramics with glass did not alter their flexural strength upon aging. An increase in the Ca₂P₂O₇ content with increasing glass up to 10 vol%, promoted both the cell viability and the osteogenic differentiation of UMR-106 cells on non-aged and aged samples. The high micro-roughness of Y-TZP with 20 vol% glass after aging, limited the proliferation and the osteogenic potential of the cultures. Y-TZP with 10 vol% glass had the best combination of properties in terms of flexural strength and osteoblast cell response.     

Assessment of sensing fire fighters uniforms for physiological parameter measurement in harsh environment

In the last few years, much effort has been devoted to the development of wearable sensing systems able to monitor physiological, behavioral, and environmental parameters. Less has been done on the accurate testing and assessment of this instrumentation, especially when considering devices thought to be used in harsh environments by subjects or operators performing intense physical activities. This paper presents methodology and results of the evaluation of wearable physiological sensors under these conditions. The methodology has been applied to a specific textile-based prototype, aimed at the real-time monitoring of rescuers in emergency contexts, which has been developed within a European funded project called ProeTEX. Wearable sensor measurements have been compared with the ones of suitable gold standards through Bland-Altman statistical analysis; tests were realized in controlled environments simulating typical intervention conditions, with temperatures ranging from 20?°C to 45?°C and subjects performing mild to very intense activities. This evaluation methodology demonstrated to be effective for the definition of the limits of use of wearable sensors. Furthermore, the ProeTEX prototype demonstrated to be reliable, since it produced negligible errors when used for up to 1 h in normal environmental temperature (20?°C and 35?°C) and up to 30 min in harsher environment (45?°C).     

A Spectrophotometric Apparatus with Laser Sources for Measurements of Fast Transient Signals

Abstract

A double beam spectrophotometric apparatus, based on laser light sources and on photodiode detectors, was built in order to perform accurate measurements of small concentration changes as those produced in chemical relaxation experiments. Relaxation techniques, where small and fastly decaying signals have to be monitored, call for high analytical sensitivity. To improve this figure of merit, the choice of a laser source proved to be particularly advantageous, since the very high light intensity, providing a remarkable reduction of the shot noise, allows signals of good quality to be obtained without amplification problems.

The measured noise was found to be close to the calculated noise, which represents the theoretical lower limiting value. Under the best conditions the signal-to-noise ratio was improved by a factor 40 with respect to a commercial apparatus equipped with conventional light source, monochromator and photomultipliers. It is shown that the circumstances where the use of the present apparatus is specially suitable are those where the dynamic techniques become superior to the static methods in the determination of thermodynamic parameters of reacting systems.     

Factors influencing incidence and extension of metachronous liver metastases of colorectal adenocarcinoma. A multivariate analysis

BACKGROUND/AIM: Three hundred and eighty-seven patients surgically treated for colorectal adenocarcinoma were assessed by a multivariate analysis and the factors influencing incidence and extension of metachronous liver metastases studied. METHODOLOGY: A series of 387 patients which had been surgically treated for colorectal adenocarcinoma between January 1980 to December 1990 and followed-up over a minimum of a 5-year period was retrospectively studied. RESULTS: The most reliable prognostic markers are represented by tumor site (p < 0.05) and, more specifically, by wall infiltration (p < 0.01) and metastatic lymph-nodes (p < 0.05). The only independent variable with a significant impact on stage of metachronous liver metastases was proved to be the depth of wall infiltration (p < 0.05). CONCLUSION: This study confirms the reliability of some indicators of primary tumor in influencing incidence, but not extension, of metachronous liver metastases and this is the main problem when it comes to using prognostic factors in order to modulate the intervals of postoperative follow-up according to risk category.     

Novel Glass‐Ceramic Composition as Sealant for SOFCs

This work deals with the design, the characterization, and testing of a novel glass‐ceramic to be used as sealant for planar solid oxide fuel cells and its compatibility with Mn_1.5Co_1.5O₄‐coated Crofer22APU. Thermal, sintering, and crystallization behavior and thermo mechanical properties of the sealant are reviewed and discussed, indicating therefore that these compositions can be deposited at 850°C and provide an excellent compatibility with both the Mn_1.5Co_1.5O₄‐coated Crofer22APU and the anode‐supported electrolyte. In particular, Mn_1.5Co_1.5O₄‐coated Crofer22APU/sealant/anode‐supported‐electrolyte joined samples have been submitted to thermal tests (in air atmosphere) from RT to 800°C (SOFC operating temperature) up to 500 h. No interactions, cracks formation, or failure were observed at the Mn_1.5Co_1.5O₄‐coated Crofer22APU/sealant interface and between the glass‐ceramic and the anode‐supported‐electrolyte after 500 h of thermal tests in air atmosphere.