Effects of dipyridamole in spontaneously hypertensive rabbits with diffuse chronic cerebral ischemia

The effect of intravenous dipyridamole (0.7 mg/kg) on cerebral blood flow (CBF), mean arterial blood pressure (MABP), heart rate, respiration rate, cerebral electrical activity, arterial blood gases, pH, and glucose was investigated in 14 normotensive and 14 stroke-prone spontaneously hypertensive anesthetized rabbits. CBF was measured by hydrogen and heat clearance. In both groups, MABP decreased (normotensive: -24 mm Hg, hypertensive: -47 mm Hg; ANOVA: P < 0.0001) and CBF increased (normotensive: +59 ml/100 g/min, hypertensive: +72 ml/100 g/min; ANOVA: P < 0.0002). CBF returned to the initial level 21 min later in hypertensive than in normotensive rabbits. Changes in other parameters were insignificant. In additional experiments, 30 mg/kg theophylline entirely prevented the cerebral vasodilator and systemic hypotensive effects of dipyridamole in both normotensive and hypertensive rabbits. We conclude that, in stroke-prone spontaneously hypertensive rabbits, the longer-lasting and larger CBF increase in response to dipyridamole may be attributed to reversible functional changes in the cerebral vasculature resulting from hypertension.     

Verformungsvorgänge bei erosiver Beanspruchung und ihre Beeinflussung durch korrosive Medien

Deformation processes by erosive treatment and influences of corrosive media As a result of our solid impact experiments on steel increased wear was established, if aqueous media are added to the particle stream. Because of the absence of any corrosion mark on the worn surfaces in SEM topography changed deformation behaviour was supposed as the cause of the enhanced material loss. This paper deals with a survey of the deformation mechanisms of the erosive surface damage. Environmental influences of deformation processes are discussed by experimental results and by a literature review.     

A model for high temperature growth of CdTe by metal organic chemical vapor deposition

A simple kinetic model for the metallorganic chemical vapor deposition (MOCVD) growth of binary epilayers, denoted byAB, is presented. The model yields the growth rate as a function of the gas-phase concentrations of the constituents, in various limiting cases. The model is corroborated with experimental results obtained by the MOCVD growth of CdTe at 480° C. The transition temperature between the surface-reaction and the gasphase mass-transfer control region is shifted to higher temperature with reduced reactor pressure and increased total flow velocity.     

Effect of electronic ANR and conventional hearing protectors on vehicle backup alarm detection in noise

An experiment was conducted wherein masked thresholds (using ascending method of limits) for a backup alarm were obtained in pink and red noise at 85 and 100 dBA for 12 participants immersed in a probability monitoring task and wearing a conventional passive hearing protection device (HPD, an earmuff or a foam earplug), an active noise reduction (ANR) headset, or no HPD at all (only in 85 dBA noise). Results revealed statistically significant between-HPD differences in red noise (from 2.3 to 3.1 dB) and in the 100-dBA noise level (from 2.6 to 4.3 dB). An additional finding, which corroborates other studies using different protocols, was that masked thresholds in 85-dBA noise were significantly lower (from 3.2 to 4.4 dB) for the occluded conditions (wearing an HPD) than for the open-ear (unoccluded) condition. This result refutes the belief among many normal-hearing workers that the use of HPDs in relatively low levels of noise compromises their ability to hear necessary workplace sounds. Actual or potential applications of this research include (a) the selection of appropriate HPDs for low-frequency-biased noise exposures wherein signal detection is important and (b) gaining insight into the appropriateness of ANR-based HPDs for certain industrial noise environments.     

Static and dynamic removal rates of a new hydrodynamic polishing tool

A new tool for hydrodynamic radial polishing, HyDra, allows for the local polishing of optical surfaces with a controllable wear rate. The results of the removal rate for different polisher types and sizes, applied air pressures for slurry expulsion, and tool height with respect to the working surface, are reported. We present a numerical analysis of the volumetric removal rate for the dynamic experiments as well as a comparison with a similar technique.     

2004 update--180-day exclusivity under the Hatch-Waxman amendments to the federal Food, Drug, and Cosmetic Act

This article updates the author's previously published article on the topic, provides some insight into recent events in this area of the law, and specifies a few minor items that were noted incorrectly in the earlier work.     

Microwave breast imaging: 3-D forward scattering simulation

Active microwave imaging (MWI) is emerging as a promising technique for the detection of biomedical anomalies such as breast cancer because of the high electrical contrasts between malignant tumors and normal tissue. Previously, we have developed fast two-dimensional forward and inverse scattering algorithms for MWI systems. In this paper, we report the full three-dimensional (3-D) forward scattering simulation in order to account for 3-D effects and to provide a fast solver in future 3-D nonlinear inverse scattering methods. The 3-D fast forward method is based on the stabilized biconjugate-gradient fast Fourier transform (BCGS-FFT) algorithm. The method has been validated for various MWI measurement scenarios. Using this fast simulation method, we demonstrate the importance of accounting for 3-D effects in MWI, and we compare numerical results with the measurements from an experimental prototype.     

Inhibition of IgE production by epsilon (epsilon) chain-specific antisense oligonucleotides (AOs) studied on human myeloma cell line U266 and peripheral blood mononuclear cells of a patient with hypereosinophilia

The study aimed to establish if there was any relationship between the blood group of the human host and schistosomiasis prevalence, intensity, incidence and related organ pathology. Urine and stool specimens were collected from the 735 school children attending a rural school in Zimbabwe to determine the Schistosoma haematobium and S. mansoni infection status of the children. The parasitology results were used to calculate prevalence and intensity of schistosomiasis infection. All the children, irrespective of infection status, were examined for signs of organ damage using ultrasonography before those that were infected were treated using a single dose of praziquantel. A blood specimen was taken from each child for blood group determination. Exactly 1 year later, parasitology was repeated to allow calculation of annual incidence of schistosomiasis infection. Of the children studied, 212 (28.8%) were of blood group 'A', 156 (21.2%) were of blood group 'B' while 367 (49.9%) belonged to blood group 'O'. The prevalence of S. haematobium was 59.6% (n = 438) while that of S. mansoni was 15.60% (n = 115). S. haematobium infection was detected among 129 (60.8%) children belonging to blood group 'A': 225 (61.30%) of blood group 'O' and 84 (53. 80%) of those belonging to blood group 'B'. S. mansoni infection was detected among 65 (30.70%) blood group 'A' children while 37 (10.10%) blood group 'O' and 13 (8.30%) blood group 'B' children were infected. Intensity, annual incidence of S. haematobium infection and related organ pathology was significantly higher among children of blood group 'A' and lowest among blood group 'O' children (P < 0.01, F-value = 6.13). Similarly, S. Mansoni intensity and incidence of infection and related liver lesions were highest among children of blood group 'A' (P < 0.005, F-value = 11.45).