Analysis of aperture-coupled microstrip antenna using thesegmentation method

The authors present an original analysis of an aperture-coupled microstrip antenna. The theory is based on the segmentation method, which considers the patch as a multiport network whose impedance matrix is deduced from a hybrid matrix, and the use of analytical expressions of the cavity admittance at the slot centre. The theory is presented for the first time, and the theoretical results are in good agreement with previous published measurements     

Estimation of the angle between ultrasound beam and blood velocitythrough correlation functions

Correlation functions, calculated on the ultrasonic echoes scattered by blood, provide a rich harvest of information concerning the local speed, which has often been underestimated; in particular, blood flow measurement usually yields only the longitudinal component of the velocity, even if significant information about the speed direction can be extracted. In this paper it is shown how correlation functions, calculated on the dependency of both time and space displacements, allow us to evaluate the angle Θ between ultrasound beam and blood flow; when straight vessels are considered, this single parameter, combined with the longitudinal velocity profile, permits the complete hemodynamic characterization. The underlying theory is developed and preliminary experimental results are presented     

Nonclassical Experimental Design Applied in the Optimization of a Placebo Granulate Formulation in High-Shear Mixer

The optimization of wet granulation in a 10-liter high-shear mixer was investigated using a nonclassical experimental mixture design. Hydroxypropylmethylcellulose, lactose, cornstarch, and microcrystalline cellulose were used as excipients of the granulate, while polyvinylpyrrolidone was used as binder. Besides the minimization of the number of experiments, the strategy applied takes into account the cost of each experiment. The introduction of such a modification allowed us to select an experimental matrix giving enough information with a relatively low number of experiments and at a minimum cost.     

Characterisation of aperture coupled microstrip patch antenna withthick ground plane

The feasibility of using a thick ground plane with an aperture coupled microstrip patch antenna while maintaining reasonable antenna performance is demonstrated using moment method and reciprocity analyses in the spectral domain. The thick ground plane, which may serve as a heatsink for active MMIC circuitry, or as a mechanical support for thin substrates, is particularly advantageous in millimetre wave phased array applications. It is found that the effect of ground plane thickness is to reduce the level of coupling from the feed line to the patch     

Reconfigurable FSS response from two layers of slotted dipolearrays

Two layer frequency selective surfaces (FSS) comprised of aperture elements on a single dielectric substrate are used to produce extremely narrow and angularly stable passband transmission responses. Experimental results are compared with predictions to verify a computer model which is based on solving a pair of coupled aperture integral equations. Reductions in bandwidth of up to a factor of seven have been achieved     

β-glucosidase Activity in Juice-Processing Enzymes Based on Anthocyanin Analysis

A screening procedure utilizing boysenberry juice as a substrate, which combined HPLC and spectrophotometric analyses, was used to measure β-glucosidase activity of enzyme preparations used for juice processing. Enzyme preparations (n = 26) were evaluated at two dosage rates. At the mean recommended dosage, one preparation produced a decrease in total monomeric anthocyanin and cyanidin-3-glucoside, relative to a control, indicating β-glucosidase activity. At 0.1% dosage, 4 enzymes produced a significant decrease in cyanidin-3-sophoroside and 2 enzymes caused an increase in cyanidin-3-rutinoside, indicating β-1,2-glucosidase activity. Such activity in juice processing enzymes was much lower and less prevalent than found previously for β-galactosidase. Botrytis cinerea also degraded anthocyanins in boysenberry juice.     

Consumer knowledge of foodborne microbial hazards and food-handling practices.

A national telephone survey was conducted of 1,620 randomly selected U.S. residents who spoke English, were at least 18 years old, and resided in households with kitchen facilities. Respondents were interviewed about their recognition of foodborne pathogens, foods at risk for transmitting infection, knowledge of safe food handling, and food-handling practices. One-third of the respondents who prepared meals reported unsafe food hygiene practices: e.g., they did not wash hands or take precautions to prevent cross-contamination from raw meat. Unsafe practices were reported more often by men, adults 18 to 29 years of age, and occasional food preparers than by women, persons 30 years old or older, and frequent food preparers. Respondents who identified a food vehicle for Salmonella spp. were more likely to report washing their hands and cleaning cutting boards after preparing raw meat and poultry. The results raise concerns about consumer food-handling practices. The influence of food safety training, food-handling experience, and age on food-handling practices should be studied further. Awareness of a food vehicle for Salmonella spp., for example, may indicate knowledge of the etiology of foodborne disease that promotes safe food handling. Understanding the factors associated with safe food handling will assist in development of effective safe-food instruction programs.     

A C-terminal region of the Saccharomyces cerevisiae transcription factor ADR1 plays an important role in the regulation of peroxisome proliferation by fatty acids

We examined the hypoxic tolerance phenomenon in vitro. Brief exposure to hypoxia induced the production of basic fibroblast growth factor (bFGF) mRNA and protein in rat cortical neurons and protected them from hypoxic injury. Cortical neurons were cultured from 18th-day rat embryos in a serum-free medium and subjected to brief (4 h) and/or prolonged (24 h) hypoxia. Neuronal damage was assessed by quantifying lactate dehydrogenase (LDH) activity in the medium. After brief hypoxia, LDH release was identical to that of the controls, whereas prolonged hypoxia caused a significant increase in LDH release, indicating neuronal death. However, if brief hypoxia was applied 2 days prior to the prolonged hypoxia, no increase in LDH release was observed. The bFGF mRNA expression was assessed with Northern blot and protein immunoreactivity with Western blot analysis. The brief period of hypoxia caused a 2.5-fold increase in bFGF mRNA and considerable bFGF protein expression 1 day later, but prolonged hypoxia caused increase in the expression of bFGF mRNA at 2 days and no protein expression until 3 days after the start of the hypoxia. When cells were subjected to prolonged hypoxia 2 days after brief hypoxia, however, no increase in bFGF mRNA was observed, while bFGF protein was expressed continuously. We also observed that exogenously applied bFGF reduced neuronal injury produced by prolonged hypoxia. The results obtained with this model suggest that brief hypoxia induces bFGF protein and thus tolerance to subsequent lethal hypoxia. Basic FGF might play a role as a tolerance-associated factor in this process. Thus, an in vitro model is useful for assessing the response of cortical neurons to hypoxic stress and for researching new factors related to ischemic tolerance.     

Monitoring cancer antigen 125 in serum of ovarian cancer patients after administration of 131I-labeled F(ab')2 fragments of OC125 antibody

We evaluated the effect of repeated administration of OC125 F(ab')2 fragments on cancer antigen (CA) 125 determination in 210 serum samples from 30 patients. We found falsely high CA 125 concentrations in 142 (68%) samples, using a homologous CA 125 enzyme immunoassay (EIA) with OC125 antibodies. The Truquant OV2 method, which involves two other murine antibodies, and the IMx CA 125 method, which uses sheep antibodies as capture antibodies, resulted in only slightly increased (false-positive) values in some samples with exceptionally high CA 125 EIA values. We measured falsely low CA 125 values in 37 (18%) samples with the Truquant OV2 method. Interferences could be eliminated by removal of serum IgG. Our results suggest that interferences are to some extent caused by anti-idiotypic IgG induced by OC125 administration. Assays involving nonmurine anti-CA 125 antibodies as capture antibodies seem to be most suited for CA 125 determination after OC125 treatment, but in every case an apparent increase of CA 125 after OC125 infusion should be validated.     

Liver fibrosis

Surfactant abnormalities may contribute to the impairment of gas exchange observed in Pneumocystis carinii pneumonia. Analysis of rat bronchoalveolar lavage (BAL) lipid extracts from normal controls, steroid controls, trimethaprim-sulfamethoxazole (TMP-SMX) controls, TMP-SMX/P. carinii pneumonia controls, and P. carinii pneumonia animals reveal similar total phospholipid and total protein levels. However, there was a marked reduction in phosphatidylglycerol (PG) from the BAL of P. carinii pneumonia rats as compared with control animals, with a decrease from 4.91 +/- 1.29 nmol/mg protein to 0.46 +/- 0.57 nmol/mg protein (p<0.05) and a decrease, as a percent of total phospholipids, from 7.7% +/- 0.88% to 0.91% +/- 0.59% (p<0.001). Furthermore, in vitro surface activities of BAL lipid extracts from control and P. carinii pneumonia rats revealed minimum surface tension increases from 9.38 +/- 1.71 mN/m in controls to 16.36 +/- 0.83 mN/m in P. carinii pneumonia rats (p<0.05) and likewise maximum surface tension increases from 22.14 +/- 4.34 mN/m to 38.57 +/- 2.07 mN/m (p<0.01). Of interest, the surface activity of PG-deficient P. carinii pneumonia BAL lipid extracts is completely restored to that of normal controls by the addition of exogenous PG. These findings suggest that a functionally abnormal surfactant occurs in P. carinii pneumonia and that this may account, in part, for the impairment of gas exchange observed in this disorder.