Continuous phase quadrature phase shift keyed signaling techniquewith coding

A continuous phase quadrature phase shift keyed (CPQPSK) modulation technique is presented. This method utilizes a conventional QPSK modulator and a phase trajectory converter to approximate M=4, h=1/4 continuous phase signal and allows low cost, low complexity, and high rate (>1 Gbit/s) CPM modem implementation for bandwidth efficient transmission through nonlinear satellite channels. Using a communications analysis computer program it has been found that CPQPSK has 99 percent out-of-band power of 0.8R (MSK has 99 percent out-of-band power of 1.2 R where R is defined as bit rate), continuous phase trajectories, and nearly constant envelope amplitude. Simulation of realistic hardware designs indicate that the CPQPSK will require an Eb/No of 14 dB to achieve a bit error rate (BER) of 10^-6. Forward error correcting techniques using block codes with an overhead of 10 percent indicate that the Eb/No requirements can be reduced to 11.2 dB for 10^-6 BER     

Approach to the poisoned patient

Routine poison management involves the following: (1) stabilization, (2) toxidrome recognition, (3) decontamination, (4) antidote administration, (5) enhanced elimination of toxin, and (6) supportive care. Stabilization involves airway, ventilation, and circulation support. In the patient with altered mental status, oxygen, naloxone, glucose, and thiamine should be administered. Symptom complexes that relate to specific classifications of toxins are referred to as toxidromes. Emesis by means of syrup of ipecac is rarely used for in-hospital gastric decontamination. Activated charcoal is a useful adsorbent for gastric decontamination. Whole bowel irrigation is useful for iron, lead, and lithium poisoning and for the body packer phenomenon. Enhancement of elimination may involve multiple doses of activated charcoal, hemodialysis, or charcoal hemoperfusion.     

New use of Foley catheter for precise vesicourethral anastomosis during radical retropubic prostatectomy

PURPOSE: We describe a new method of using a Foley catheter to assist vesicourethral anastomosis during radical retropubic prostatectomy. MATERIALS AND METHODS: A total of 81 patients underwent radical retropubic prostatectomy with this technique. Followup ranged from 4 to 48 months. Peri-catheter urethrograms were performed at 3 weeks. Patients were evaluated specifically for bladder neck contracture, urinary continence and prolonged catheterization. RESULTS: Bladder neck contracture, occurred in 4.9% of the patients and 87.6% were completely continent of urine. Only 1 patient required extended postoperative catheterization. CONCLUSIONS: Use of a Foley catheter for vesicourethral anastomosis is consistent and simple, and provided good surgical results in our experience.     

Multiple solution conformations of the integrin-binding cyclic pentapeptide cyclo(-Ser-D-Leu-Asp-Val-Pro-). Analysis of the (phi, psi) space available to cyclic pentapeptides

The aqueous solution structure of the cyclic pentapeptide cyclo(-Ser-D-Leu-Asp-Val-Pro-) has been determined by two-dimensional 1H-NMR spectroscopy, combined with a conformational search and distance-geometry calculations. As many as five conformers in slow exchange were observed, and the rate of interconversion between components was measured from the build-up rates of exchange peaks. NMR data allowed the structures of the two predominant conformers to be determined. The major component (66%) contained a cis-proline as part of a type-VIa2 beta-turn encompassing residues Asp-Val-cis-Pro-Ser. The second component (16%) contained only trans-amide bonds, and a type-VIII beta-turn formed by residues Val-Pro-Ser-D-Leu. These structures are discussed in relation to the (phi, psi), space available to the cyclic pentapeptide, determined by a conformational search, and in relation to previously published cyclic-pentapeptide structures. The molecule exhibits activity in a scintillation-proximity assay for the inhibition of the interaction between the integrin very-late antigen-4 (VLA-4; alpha 4 beta 1) and vascular-cell-adhesion molecule-1 (VCAM-1). The structure/activity relationship of the LDV sequence is discussed and related to the recently published X-ray structure of VCAM-1. The relevance of the work to the design of anti-inflammatory drugs is discussed.     

Mass transfer across wind-sheared interfaces

A predictive analogy of turbulent mass transfer across wavy, sheared air-water interface, in deep water bodies is proposed. The theory is based on the formulation of a theoretical eddy diffusivity profile in the surface region, and it applies to the non-breaking wave regime. The predictions for a water-side friction velocity range of 0.5–6 cm/s are in excellent agreement with laboratory data from wind-wave facilities with an average error of 15.4%.     

Identification and disruption of a plant shaker-like outward channel involved in K+ release into the xylem sap

SKOR, a K+ channel identified in Arabidopsis, displays the typical hydrophobic core of the Shaker channel superfamily, a cyclic nucleotide-binding domain, and an ankyrin domain. Expression in Xenopus oocytes identified SKOR as the first member of the Shaker family in plants to be endowed with outwardly rectifying properties. SKOR expression is localized in root stelar tissues. A knockout mutant shows both lower shoot K+ content and lower xylem sap K+ concentration, indicating that SKOR is involved in K+ release into the xylem sap toward the shoots. SKOR expression is strongly inhibited by the stress phytohormone abscisic acid, supporting the hypothesis that control of K+ translocation toward the shoots is part of the plant response to water stress.     

Postembryonic neurogenesis in the central nervous system of the tobacco hornworm, Manduca sexta. III. Spatial and temporal patterns of proliferation

Postembryonic neurogenesis leads to a dramatic increase in the number of functional neurons within the segmental ganglia of the moth, Manduca sexta. These adult-specific neurons are generated during larval life by segment-specific arrays of individually identifiable stem cells, or neuroblasts (Nbs). By the end of the feeding larval stage, each Nb has generated a discrete nest of progeny, which ranges in size from less than 10 to more than 70 progeny. The sizes of these identifiable nests of progeny vary in a segment-specific manner, with the thoracic nests containing a greater number of progeny compared with their homologues in the simpler abdominal ganglia. In order to describe those factors that influence the size of the post-embryonic neuronal lineages, we examined the spatial and temporal pattern of postembryonic neurogenesis in the segmental ganglia of Manduca. The rates at which the identifiable nests accumulated progeny were estimated by counting the number of progeny within the nests, using sectioned material isolated from animals at stages ranging from embryonic hatching until the end of the feeding larval stage. All of the postembryonic Nbs began to generate progeny at around the time of the molt to the third larval instar. Each nest added progeny at a rate that was a characteristic of its identity and segment of origin. Although all of the nests within the thorax continued to accumulate progeny throughout the feeding larval stage, several of the abdominal nests showed little or no growth following the molt to the fifth larval instar. The thymidine analog 5-bromo 2-deoxyuridine (5-BrdU) was used to estimate the mitotic rates of the identifiable Nbs. The number of labeled progeny within a nest 24 h after application of 5-BrdU ranged from a low of 1 to 2 to a high of 11 to 13 labeled cells. In some instances there was a good correlation between the estimated mitotic rate of an identified Nb and the rate of growth of its associated nest of progeny. However, several of the identifiable nests accumulated progeny at a slower rate than predicted based on the estimated mitotic rate of the Nb. Cell death appears to be responsible for slowing the growth of the nests during the feeding larval stage. We estimate that 10% to 70% of the neurons generated during the feeding larval stage degenerate within 24 h of their birth. The level of cell death observed within a nest was dependent on both its identity and its segment of origin.     

2-year clinical evaluation of a gallium restorative alloy

PURPOSE: To assess the clinical performance of 2-year old gallium alloy restorations. Parameters evaluated include: (1) fracture at the margins, (2) tarnish, (3) surface roughness, (4) tooth fracture, (5) fracture through the body of the restoration, and (6) any medical or dental conditions arising during the study. MATERIALS AND METHODS: Nine patients received 30 Class I restorations of Galloy gallium alloy. These were placed as conservatively as possible under a rubber dam. Fifteen of the preparations were lined with a Bis-GMA resin to seal the restoration from moisture. The other 15 preparations were sealed with Amalgambond. After placement of the gallium alloy, the exposed surfaces of all restorations were sealed with the Bis-GMA resin, and the occlusion was checked. The restorations were examined at 2 weeks, 3 months, 6 months, 1 year and 2 years. RESULTS: At the 2-year recall, all restorations were intact with the exception of one tooth fracture (cause unknown). Forty-five percent of the restorations exhibited tarnish and 60% had a rough surface. The fracture at the margins of these restorations was minimal, and no significant difference could be found between those using Amalgambond and those sealed with the resin system. No medical problems were reported by the patients, and postoperative sensitivity was minimal.