Continuous-fiber reinforced composites: A new generation

The mechanical and physical properties of aluminum-matrix composites reinforced with high-performance continuous alumina fibers are reviewed and compared with those of other structural materials. Continuous-fiber reinforced aluminum-matrix compositesoffer outstanding improvements in specific strength and specific stiffness over conventional alloys and particulate composites. Thelongitudinal tensile strength of an aluminum matrix reinforced with 55–65 vol.% alumina fibers is in the range ofl.4-1.9 GPa, the longitudinal Young's modulus is 220–240 GPa, and the density is 3.2-3.4 g/cm3. The mechanisms of strengthening and fracture under longitudinal, transverse, and shear loading are reviewed. Examples of applications are presented that are representative of the range of product forms being developed.     

Influence of inhaled nitric oxide on systemic flow and ventricular filling pressure in patients receiving mechanical circulatory assistance

BACKGROUND: In patients with left ventricular (LV) dysfunction, inhaled nitric oxide (NO) decreases pulmonary vascular resistance (PVR) but causes a potentially clinically significant increase in left atrial pressure (LAP). This has led to the suggestion that inhaled NO may reach the coronary circulation and have a negative inotropic effect. This study tested an alternative hypothesis that LAP increases because of volume shifts to the pulmonary venous compartment caused by NO-induced selective pulmonary vasodilation. METHODS AND RESULTS: The Thermo Cardiosystems Heartmate is an LV assist device (LVAD) that can be set (by controlling pump rate) to deliver fixed or variable systemic blood flow. Eight patients (between 1 and 11 days after LVAD implantation) were administered inhaled NO (20 and 40 ppm for 10 minutes), and LAP, systemic flow, and pulmonary arterial pressure were measured in both fixed and variable pump flow modes. In both modes, inhaled NO lowered PVR (by 25 +/- 6% in the fixed mode, P < .001, and by 21 +/- 5% in the variable mode, P < .003). With fixed pump flow, LAP rose from 12.5 +/- 1.2 to 15.1 +/- 1.4 mm Hg (P < .008). In the variable flow mode, LAP did not increase and the assist device output rose from 5.3 +/- 0.3 to 5.7 +/- 0.3 L/min (P < .008). CONCLUSIONS: A selective reduction in PVR by inhaled NO can increase LAP if systemic flow cannot increase. These data support the hypothesis that with LV failure, inhaled NO increases LAP by increasing pulmonary venous volume and demonstrate that inhaled NO has beneficial hemodynamic effects in LVAD patients.     

Cystic fibrosis: a system for assessing and predicting progression

Renal lymphoma has a broad spectrum of imaging manifestations. Typical patterns of renal lymphoma include multiple renal masses, solitary masses, diffuse infiltration, and invasion from contiguous retroperitoneal disease. Isolated perirenal disease is probably the most atypical form of renal lymphoma and has a variety of appearances, including small curvilinear densities and soft-tissue nodules or plaques. In general, the CT diagnosis of renal lymphoma is not difficult because most patients already have a known diagnosis of lymphoma. Nevertheless, it is important to be familiar with both the typical and the atypical manifestations of renal lymphoma because numerous disease processes, normal variants, and artifacts may potentially mimic renal lymphoma.     

Synergic action of aging and moisture on native and different grades of commercial gutta-percha (trans-polyisoprene)

The aim of this paper was to study the plasticizing effect of subjecting native/commercial gutta-percha samples to controlled levels of different humidities. It was expected that this study would provide the practicing endodontist with invaluable insight into the mechanical properties of commercial gutta-percha cones (i.e., retrievability, malleability, flexibility, and torsional and bending ability). The “conditioning” of the gutta-percha samples depended greatly on the percentage of compatible/incompatible substances. The mixtures of native gutta-percha with compatible (i.e., wax) showed greater elongation, tensile strength, and number of rotations, but lower deformation angle than the mixtures of native gutta-percha with incompatible substances (i.e., salts, metal oxides). The observed lower values for tensile strength and torsional strain, relative energy to break, and the Young's modulus and the higher values for elongation and number of rotations for wet samples compared to the dry ones were attributed to the plasticizing effect of gutta-percha due to the insertion of water molecules in the polymer chains. © 1993 John Wiley & Sons, Inc.     

Extraction of protein and solids from wheat bran

The influence of pH, time, temperature, cellulase treatment and washing conditions on the recovery of solids and protein from Australian wheat bran was investigated. Highest yields (83% of available protein, 72% of total solids) were achieved by extracting at pH 12 and washing with water at pH 7. However, acceptable yields could be obtained under near neutral conditions by extracting at pH 6.5 for 16 h followed by three washes at pH7. Under these conditions 72% of the protein and 55% of the total solids were extracted and greater stability of the vitamins thiamin, riboflavin and pyridoxine was expected. The use of cellulase in an attempt to disrupt the aleurone cell walls did not improve the recoveries of either protein or solids.     

Neuropapillitis in Beh?et disease. A case

The authors report the case of a 34 year old woman, who developed acute neuropapillitis, which appeared to be the first ophthalmologic manifestation of Beh?et's disease. One year later, this patient recurred with another neuro-ophthalmologic sign: a sixth nerve palsy.     

Cause and effect 3-D model for measuring performance in construction acceleration: A decision support system

Despite the constant improvements in the management of building projects, the authors express concerns about the difficulties in controlling progress with construction, despite the availability of quantifiable and non-quantifiable data. They believe that a decision support system would assist managers when confronted by the consequences of arising delays, and by the decision whether and how to accelerate the remaining construction activities. The system has the advantages of providing support when facing an ill-structured decision about accelerating progress when delays occur; it also helps as a predictive management tool for minimizing or avoiding delays and their consequential claims.     

Psychopathy and the DSM-IV criteria for antisocial personality disorder.

The Axis II Work Group of the Task Force on Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) has expressed concern that antisocial personality disorder (APD) criteria are too long and cumbersome and that they focus on antisocial behaviors rather than personality traits central to traditional conceptions of psychopathy and to international criteria. R. D. Hare et al describe an alternative to the approach taken in the DSM-III—Revised (DSM-III—R; American Psychiatric Association, 1987), namely, the revised Psychopathy Checklist. The authors also discuss the multisite APD field trials designed to evaluate and compare 4 criteria sets: the DSM-III—R criteria, a shortened list of these criteria, the criteria for dyssocial personality disorder from the 10th edition of the International Classification of Diseases (World Health Organization, 1990), and a 10-item criteria set for psychopathic personality disorder derived from the revised Psychopathy Checklist. (PsycINFO Database Record (c) 2010 APA, all rights reserved)