Preparation of ultra‐low‐density microcellular materials

Microcellular polymeric materials can be obtained by the polymerization of a high‐internal‐phase emulsion. These materials are good candidates as targets toward inertial confinement fusion. This application requires severe specifications, including a very low density and a small cell size. In this study, we examined the influence of parameters such as emulsification conditions, surfactant nature, and the presence of a porogen on the obtainment of those requirements. It was possible to obtain microcellular polymeric foams with apparent densities as low as 0.0126 g/cm³. However, it was difficult to obtain very low material density and still maintain a small average pore size. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2053–2063, 2005     

Smart cars, smart highways

Advanced electronics is being used to unclog the transportation network and allow private vehicles, trucks, buses and trains to move further faster. already a range of technologies and ideas have been explored, deployed, and tested as part of the Intelligent Vehicle Highway System programs in the United States and Japan, and in the Road Transport Informatics program in Europe. The authors describe how these latest electronics for automobiles and roadways herald far fewer traffic jams, greater safety, and perhaps even a decline in pollution     

Catch me if you can: are catechol- and indoleamine genes pleiotropic QTLs for common mental disorders?

The aim of this study was to determine the effect of a short-term ethinyl estradiol/levonorgestrel medication on blood flow in the uterine arteries in postmenopausal women in a prospective placebo-controlled double-blind study. Twenty-one healthy postmenopausal woman at least 2 years after menopause received 60 micrograms ethinyl estradiol (EE) for 14 days followed by 40 micrograms EE plus 125 micrograms levonorgestrel (LNG) for 12 days (total treatment period 26 days). Sonographically, uterine volume, endometrial thickness, and blood flow in the uterine arteries [as reflected by pulsatility (PI) and resistance indices (RI)] were measured. Uterine size increased from 44 to 80 mL (day 14, p < 0.001) and 87 mL (day 26, p = NS). Endometrium grew from 3 to 8 mm (day 14, p < 0.001) and 11 mm (day 26, p = NS). Uterine arterial PI fell from 2.76 to 1.37 (day 14, p < 0.001) and 1.34 (day 26, p = NS), whereas RI fell from 0.9 to 0.68 (day 14 and day 26, p < 0.001). In conclusion, short-term treatment with LNG does not antagonize the vascular effect of EE on the uterine arteries as reflected by PI and RI. This result might have clinical significance in the selection of the progestin used in hormonal replacement therapy.     

Determination of epithelial tissue scattering coefficient using confocal microscopy

Most models of light propagation through tissue assume the scattering properties of the various tissue layers are the same. The authors present evidence that the scattering coefficient of normal cervical epithelium is significantly lower than values previously reported for bulk epithelial tissue. They estimated the scattering coefficient of normal and precancerous cervical epithelium using measurements of the reflectance as a function of depth from confocal images. Reflectance measurements were taken from ex vivo cervical biopsies and fit to an exponential function based upon Beer's law attenuation. The mean scattering coefficients derived were 22 cm/sup -1/ for normal tissue and 69 cm/sup -1/ for precancerous tissue. These values are significantly lower than previously reported for bulk epithelial tissues and suggest that scattering of bulk tissue is dominated by the stroma. They also suggest that computational models to describe light propagation in epithelial tissue must incorporate different scattering coefficients for the epithelium and stroma. Further, the lower scattering of the epithelium suggests greater probing depths for fiber optic probes used by optical diagnostic devices which measure reflectance and fluorescence in epithelial tissue. The difference in scattering between normal and precancerous tissue is attributed to increased nuclear size, optical density, and chromatin texture. The scattering coefficients measured here are consistent with predictions of numerical solutions to Maxwell's equations for epithelial cell scattering.     

Effects of climatic and management factors on conception rate of dairy cattle in subtropical environment

Breeding records, representing 12,038 inseminations at Bassett's Dairy Farm (Monticello, FL), were analyzed to document effects of environmental and management factors on fertility of dairy cattle from January 1, 1975 to December 31, 1977. Conception rates of lactating cows decreased sharply when maximum air temperature on day after insemination exceeded 30 degrees C. In contrast, conception rates for heifers did not decline until 35 degrees C. Virgin heifers had higher conception rates for all services (50%) than lactating cows (34%) and suffered only slight depression of fertility during summer months. Heifers required 1.5 services per conception compared with 2.3 for lactating cows. Relationship between conception rate and rainfall on day after insemination was negative and curvilinear. Jerseys had higher conception rates (45%) than Holstein (39%) and Brown Swiss (41%). Services per conception were 1.7, 2.0, and 1.9. Substantial decreases of fertility were associated with advancing service number. Estrous status (standing; positive heat detection patch; mounting activity), inseminator, and year of service were related to variation of conception rate. Seasonal effects on fertility of lactating cows were marked. Thus, environmental management of the postpartum cow during hot summer months is warranted to maximize fertility.     

Percutaneous transjejunal biliary intervention: 10-year experience with access via Roux-en-Y loops

Ancylostoma duodenale is still the dominant hookworm species in the Mediterranean area, India, China and Japan. In the present study, biopsied materials were taken from the small intestine of 30 patients infected only with A. duodenale and 12 cross matched controls. The results showed some pathological changes in severely infected cases. However, normal or insignificant changes were seen in the enzymatic activity of the intestinal mucosa.     

Acute erythroleukemia: evaluation of 48 cases with reference to classification, cell proliferation, cytogenetics, and prognosis

We evaluated 48 archival cases of acute erythroleukemia and divided them into 3 groups: M6a, corresponding to the traditional French-American-British M6 category; M6b, which is pure erythroleukemia; and M6c, in which myeloblasts and pronormoblasts each account for more than 30% of cells by the French-American-British exclusion criteria. No significant differences were noted among the subtypes for ratio of males to females; age; or exposure to toxins, alcohol, or both. However, compared with the patients in the M6a group, patients in the M6b and M6c groups demonstrated a statistically significant increase in cytogenetic aberrations, proliferation markers (proliferating cell nuclear antigen and Ki67), and ringed (type III) sideroblasts. Marked survival differences were noted between the M6a (30.1 +/- 29.5 months) and M6b (3.15 +/- 4.2 months) groups, with patients in the M6c group demonstrating an intermediate prognosis (10.5 +/- 12.7 months). Chemotherapeutic regimens induced remission in all treated patients in the M6a and M6c groups but did not appear to affect the M6b group. However, the patients in the M6c group remained in remission for a significantly shorter period of time than did patients in the M6a group. Overall, survival appeared to depend on the ratio of pronormoblasts to myeloblasts at diagnosis and demonstrated a rapid decline with increasing pronormoblast and decreasing myeloblast counts. We must, therefore, devise chemotherapeutic regimens that target both blastic components of this disease.     

Coding techniques for process plant VDU formats

The results of a literature survey of human performance and coding techniques are presented. Recommendations are given for the application of coding techniques to the design of VDU formats (screen layouts) in a process plant context. The coding techniques considered are colour, brightness, inverse video, flash, size and shape. The recommendations discuss the relative merits of the different techniques for presenting plant information, and the practical problems of applying a particular code. Some suggestions are given for further work.     

The mechanical properties and microstructures of copper and brass joints soldered with eutectic tin-bismuth solder

The mechanical properties and microstructures ofcopper and brass soldered with eutectic tin-bismuth solder have been determined and the joints examined using metallographic techniques. Joints made with copper were stronger than those made with brass. At the copper/solder interface a uniform layer 2m thick of Cu_5.2Sn₅ was formed and at the brass/solder interface a uniform layer 2 m thick of (Cu, Zn)_2.9Sn and an irregular layer 2 to 5m thick of (Cu, Zn)_5.7Sn₅ were formed. Copper joints fractured etthocopper/solder interface and brass joints fractured in the internmetalic layer. Copper joints soldered with eutectic Sn-Bi were stronger than copper joints soldered with eutectic Sn-Pb and the reverse was true for brass joints. Results are also given for the effect of thermal shock on copper and brass joints soldered with Sn-Bi and Sn-Pb solders, and also for We fatigue and creep behaviour of joints soldered with eutectic Sn-Bi solder.     

Non-insulin dependent diabetes mellitus in Psammomys obesus is independent of changes in tissue fatty acid composition

Recently it has been postulated that membrane fatty acid composition may be involved in the pathogenesis of insulin resistance and non-insulin dependent diabetes mellitus (NIDDM). The aim of this study was to determine whether alterations in tissue phospholipid (PL) fatty acids are present in hyperglycemic and hyperinsulinemic Psammomys obesus. On a native diet of salt bush, P. obesus (Israeli sand rat) remains lean and free of diabetes; however, when placed on a normal laboratory chow, a significant proportion of these animals develops a number of metabolic disorders associated with NIDDM, providing an ideal animal model of obesity and NIDDM. Four groups of mature P. obesus were studied: group A; normoglycemic and normoinsulinemic; group B: normoglycemic and hyperinsulinemic; group C: hyperglycemic and hyperinsulinemic; and group D: hyperglycemic hypoinsulinemic. In liver and red gastrocnemius muscle, there were no significant differences between groups, A, B, and in fatty acid composition of PL. Minor differences in individual fatty acids were demonstrated in group D animals (increased liver 20∶4n-6 and increased muscle 22∶5n-3); however, the unsaturation indices in liver and muscle were not significantly different between any of the groups. In considering that the minor changes in group D animals were not demonstrated in hyperinsulinemic group B animals or hyperglycemic, hyperinsulinemic group C animals, it is likely that the differences in group D animals were secondary to the more severe disturbances in glucose homeostasis and hypoinsulinemia present in these animals. The results of this study suggest that in this rodent diabetic model significant disturbances in glucose homeostasis and hyperinsulinemia may develop independently of changes in tissue fatty acid composition.