Nano‐alumina modified epoxy based film adhesives

Epoxy based film adhesives were developed that contained nano‐sized alumina particles of different size and shape. These nano‐scale materials were incorporated at 5 and 10 weight percent into an adhesive formulation that was filmed on polyester random mat scrim. Films were applied to composite substrates for fracture testing and aluminum substrates for lap shear and peel testing. Scanning electron microscopy was used to characterize the surfaces of both the aluminum and composite specimens. Results from the bonded aluminum samples showed that in almost all cases the additives increased the peel and shear strength of the adhesives. Composite samples yielded results that were less clear, but still demonstrated that nano‐scale additives can increase the fracture toughness of a thermosetting adhesive.     

Changes in maximum oxygen uptake during prolonged training, overtraining, and detraining in horses

Thirteen standardbred horses were trained as follows: phase 1 (endurance training, 7 wk), phase 2 (high-intensity training, 9 wk), phase 3 (overload training, 18 wk), and phase 4 (detraining, 12 wk). In phase 3, the horses were divided into two groups: overload training (OLT) and control (C). The OLT group exercised at greater intensities, frequencies, and durations than group C. Overtraining occurred after 31 wk of training and was defined as a significant decrease in treadmill run time in response to a standardized exercise test. In the OLT group, there was a significant decrease in body weight (P < 0.05). From pretraining values of 117 +/- 2 (SE) ml.kg-1.min-1, maximal O2 uptake (VO2max) increased by 15% at the end of phase 1, and when signs of overtraining were first seen in the OLT group, VO2max was 29% higher (151 +/- 2 ml.kg-1.min-1 in both C and OLT groups) than pretraining values. There was no significant reduction in VO2max until after 6 wk detraining when VO2max was 137 +/- 2 ml.kg-1.min-1. By 12 wk detraining, mean VO2max was 134 +/- 2 ml.kg-1.min-1, still 15% above pretraining values. When overtraining developed, VO2max was not different between C and OLT groups, but maximal values for CO2 production (147 vs. 159 ml.kg-1.min-1) and respiratory exchange ratio (1.04 vs. 1.11) were lower in the OLT group. Overtraining was not associated with a decrease in VO2max and, after prolonged training, decreases in VO2max occurred slowly during detraining.     

Photoreactive analog of peptide FN-C/H-V from the carboxy-terminal heparin-binding domains of fibronectin supports endothelial cell adhesion and spreading on biomaterial surfaces

RF catheter ablation is a safe and extremely effective method of achieving complete A-V block in patients with difficult-to-control ventricular rates in atrial fibrillation. In selected patients, A-V junction ablation may improve exercise capacity and functional status while reducing the need for emergency care and hospitalization. Prospective, randomized studies are needed, however, to compare A-V junction ablation as a management strategy to pharmacologic therapy to control ventricular rate or to maintain sinus rhythm. Similarly, additional data are needed to assess methods of achieving A-V junction modification with the lowest risk for A-V block.     

Double dissociation between the involvement of the bed nucleus of the stria terminalis and the central nucleus of the amygdala in startle increases produced by conditioned versus unconditioned fear

The amplitude of the acoustic startle response is reliably enhanced when elicited in the presence of bright light (light-enhanced startle) or in the presence of cues previously paired with shock (fear-potentiated startle). Light-enhanced startle appears to reflect an unconditioned response to an anxiogenic stimulus, whereas fear-potentiated startle reflects a conditioned response to a fear-eliciting stimulus. We examine the involvement of the basolateral nucleus of the amygdala, the central nucleus of the amygdala, and the bed nucleus of the stria terminalis in both phenomena. Immediately before light-enhanced or fear-potentiated startle testing, rats received intracranial infusions of the AMPA receptor antagonist 2, 3-dihydroxy-6-nitro-7-sulphamoylbenzo(F)-quinoxaline (3 microg) or PBS. Infusions into the central nucleus of the amygdala blocked fear-potentiated but not light-enhanced startle, and infusions into the bed nucleus of the stria terminalis blocked light-enhanced but not fear-potentiated startle. Infusions into the basolateral amygdala disrupted both phenomena. These findings indicate that the neuroanatomical substrates of fear-potentiated and light-enhanced startle, and perhaps more generally of conditioned and unconditioned fear, may be anatomically dissociated.     

The cloned gene, Xa21, confers resistance to multiple Xanthomonas oryzae pv. oryzae isolates in transgenic plants

The cloned rice gene, Xa21, confers resistance to multiple pathogen isolates of Xanthomonas oryzae pv. oryzae in transgenic plants. The resistance phenotype was stably transmitted to T1 progeny and inherited as a single locus. The T1 progeny were tested for resistance to 32 X. oryzae pv. oryzae isolates from eight countries. Both the engineered line and the donor line showed resistance to 29 isolates and susceptibility to three isolates. The identical resistance spectrum of both lines indicates that the presence of a single member of a multigene family, Xa21, is sufficient to confer multi-isolate resistance. The results presented here have important implications for engineering disease resistance in crop plants.     

Automated 3-D registration of MR and CT images of the head

This paper discusses the application of voxel similarity measures in the automated registration of clinically acquired MR and CT data of the head. We describe a novel single-start multi-resolution approach to the optimization of these measures, and the issues involved in applying this to data having a range of different fields of view and sampling resolution. We compare four proposed measures of voxel similarity using the same optimization scheme when presented with 10 pairs of images with a range of initial misregistrations. The registration estimates are compared with those provided by manual point-based registration and evaluated by visual inspection to give an assessment of the robustness and accuracy of the different measures. One full-volume CT image set is used to investigate the performance of each measure when used to align truncated images from different regions in the head. The soft tissue correlation and mutual information measures were found to provide the most robust measures of misregistration, providing results comparable to or better than those from manual point-based registration for all but the most truncated image volumes.     

Impact of aging on gastrointestinal mucosal immunity

More than two million tympanotomy tubes are placed annually in the United States, making this operation the most common performed on children. This article provides an overview of the applications of tympanotomy tubes for the treatment for otitis media in childhood. The indications for tube placement are discussed; a visual guide for managing children with tympanostomy tubes is presented; an approach to dealing with tube complications is outlined; and guidelines for referral to a pediatric otolaryngologist are suggested.     

Monitored outpatient management of mild gestational hypertension remote from term in teenage pregnancies

OBJECTIVE: Our purpose was to compare maternal and perinatal outcomes of teenage and adult pregnancies with mild gestational hypertension remote from term managed with an outpatient program. STUDY DESIGN: A matched cohort design was used. Maternal and perinatal outcomes of 60 teenage pregnancies with mild gestational hypertension remote from term were compared with 120 adult controls 20 to 42 years old. The groups were matched for race, gestational age, and proteinuria status at enrollment. All were monitored on an outpatient basis with four times daily automated blood pressure measurement and daily assessment of weight, proteinuria, and fetal movement. RESULTS: The mean gestational age at enrollment was 33.5 +/- 2.6 weeks for both groups (range 27 to 36 weeks). Only 60% of teenagers had a high school degree or equivalent compared with 76% of adults (p = 0.024). The teenagers were more likely than the adults to be of single marital status (75% vs 13%, p = 0.015). The mean gestational age at delivery (37.0 +/- 2.0 vs 37.0 +/- 2.2 weeks), mean pregnancy prolongation (23.5 +/- 19.0 vs 24.5 +/- 17.4 days), and mean birth weights (2915 +/- 669 vs 2879 +/- 678 gm) were not statistically different between the teenagers and adults (all p > 0.05). There were no stillbirths, neonatal deaths, or cases of eclampsia in either group. CONCLUSIONS: In spite of a study population characterized by limited education, single marital status, and young age at enrollment, monitored outpatient management of mild gestational hypertension remote from term in teenage pregnancies is associated with maternal and perinatal outcomes similar to those observed in adults.