Mixed-dimensional coupling in finite element models

In many finite element analysis models it would be desirable to combine reduced- or lower-dimensional element types with higher-dimensional element types in a single model. In order to achieve compatibility of displacements and stress equilibrium at the junction or interface between the differing element types, it is important in such cases to integrate into the analysis some scheme for coupling the element types. A novel and effective scheme for establishing compatibility and equilibrium at the dimensional interface is described and its merits and capabilities are demonstrated. Copyright (C) 2000 John Wiley & Sons, Ltd.

An Innovative Model for the Provision of Practice Learning Opportunities in Family and Child Care: Newry Student Unit, Southern Health and Social Care Trust.

This article describes the work of Newry Student Unit which operates in the Southern Health and Social Care Trust. The background to the unit is outlined and its development is discussed in the context of practice learning provision in Northern Ireland. The operation of the unit in providing Family and Child Care practice learning opportunities (PLOs) for student social workers is outlined and findings from evaluation questionnaires completed by students, college tutors and team leaders are presented. The paper highlights both the advantages and disadvantages of this model of PLO provision and concludes that it is a valuable resource for practice learning. Proposals for the development of the unit are discussed and it is suggested that the model has the potential be replicated in other areas of Northern Ireland.

Extravascular lung water indexed to predicted body weight is a novel predictor of intensive care unit mortality in patients with acute lung injury

Objectives: Acute lung injury and the acute respiratory distress syndrome are characterized by noncardiogenic pulmonary edema, which can be assessed by measurement of extravascular lung water. Traditionally, extravascular lung water has been indexed to actual body weight (mL/kg). Because lung size is dependent on height rather than weight, we hypothesized indexing to predicted body weight may be a better predictor of mortality in acute lung injury/acute respiratory distress syndrome.

Routine delirium monitoring in a UK critical care unit

Introduction Delirium in the intensive care unit (ICU) is associated with increased morbidity and mortality. Using an assessment tool has been shown to improve the ability of clinicians in the ICU to detect delirium. The confusion assessment method for the ICU (CAM-ICU) is a validated delirium-screening tool for critically ill intubated patients. The aim of this project was to establish the feasibility of routine delirium screening using the CAM-ICU and to identify the incidence of delirium in a UK critical care unit.

Nonlinear frequency coupling in dual radio-frequency driven atmospheric pressure plasmas

Plasma ionization, and associated mode transitions, in dual radio-frequency driven atmospheric pressure plasmas are governed through nonlinear frequency coupling in the dynamics of the plasma boundary sheath. Ionization in low-power mode is determined by the nonlinear coupling of electron heating and the momentary local plasma density. Ionization in high-power mode is driven by electron avalanches during phases of transient high electric fields within the boundary sheath. The transition between these distinctly different modes is controlled by the total voltage of both frequency components.

Palladium-mediated reductive coupling, a stereoselective approach to the 8-dehydropumiliotoxin skeleton

Reductive cyclisation of ail E-vinyl bromide with ail allylic acetate proceeds under palladium catalysis 10 give the 8-dehydropumiliotoxin skeleton, a potential advanced precursor to 8-deoxypumiliotoxin alkaloids. Control of the stereochemistry of the E-vinyl bromide precursor is achieved readily using the Kogen or Bruckner bromophosphonate reagents and the reductive cyclisation proceeds with retention of the vinyl bromide stereochemistry. The mechanism for the cyclisation involves an in situ conversion of the allylic acetate to ail allyl stannane followed by ail intramolecular Stille-type coupling.

Multi component coupling reactions of N-acetyl-2-azetine

N-Acetyl-2-azetine undergoes Lewis acid catalysed formal [4+2]-cycloaddition with imines derived from aromatic amines to initially give an approximately 1: 1 mixture of exo-endo-diastereoisomeric 1-(2a,3,4,8b-tetrahydro-2H-1,4-diaza-cyclobuta[a]naphthalen-1-yl)-ethanone cycloadducts which were detected by proton NMR spectroscopy. These products, which were too unstable to isolate, and characterise, reacted further with aromatic amines to give 2,3,4-trisubstituted tetrahydroquinolines in good to excellent yield, predominantly as a single diastereoisomer, with the minor diastereoisomer converting to the major diastereoisomer on silica. The cycloaddition was irreversible and a mechanism is presented for the formation of the major diastereoisomer from the mixture of diastereoisomeric intermediates. A range of conditions is described for converting the 2,3,4-trisubsitituted tetrahydroquinolines into 2,3-disubstituted quinolines.

Three component coupling reactions of N-acetyl-2-azetine-rapid stereoselective entry to 2,3,4-trisubstituted tetrahydroquinolines

N-Acetyl-2-azetine undergoes Lewis acid catalysed [4 + 2]-cycloaddition with imines derived from aromatic amines and gave a 1:1 mixture of exo-endo diastereoisomeric azetidine cycloadducts which reacted further with aromatic amine, to give 2,3,4-trisubsitituted tetrahydroquinolines in good to excellent yield, predominantly as one diastereoisomer.

Modelling the Geometry of the Repeat Unit Cell of Three-Dimensional Weave Architectures,

The three-dimensional (3D) weaving process offers the ability to tailor the mechanical properties via design of the weave architecture. One repeat of the 3D woven fabric is represented by the unit cell. The model accepts basic weaver and material manufacturer data as inputs in order to calculate the geometric characteristics of the 3D woven unit cell. The specific weave architecture manufactured and subsequently modelled had an angle interlock type binding configuration. The modelled result was shown to have a close approximation compared to the experimentally measured values and highlighted the importance of the representation of the binder tow path.

Synthesis of the alkaloids hopromine, hoprominol and hopromalinol, using transamidation methods.

Synthesis of the unsym. Homalium alkaloids hopromine (I, R = H, R1 = pentyl), hoprominol (I, R = OH, R1 = pentyl) and hopramalinol (I, R = OH, R1 = Ph), in diastereoisomeric mixt. form, is reported. The component eight-membered azalactams are first prepd. N-(3-halogenopropyl)-4-pentyl- and 4-heptylazetidin-2-ones are aminated and ring expanded in liq. ammonia to give, after reductive methylation, the corresponding 4-alkyl-5-methyl-1,5-diazacyclooctan-2-ones. Synthesis of the 4-(2-hydroxyheptyl)-5-methyl-1,5-diazacyclooctan-2-one required for hoprominol and hopromalinol is carried out via 4-allyl ?-lactam ring expansion to the eight-membered 4-allylazalactam, followed by methylation, epoxidn. and epoxide opening with lithium dibutylcuprate. A similar epoxidn.-cuprate sequence was carried out on the epoxypropyl ?-lactam, as its N-tert-butyldimethylsilyl deriv., and led to a convenient copper-catalyzed N- to O-migration of the protection; this migration is examd. Alkylation gave O-tert-butyldimethylsilyl-protected N-(3-chloropropyl)-4-(2-hydroxyheptyl)azetidin-2-one which could be aminated and transamidated in excellent yield, to give, after methylation, a superior sequence to the required eight-membered hydroxy azalactam. Although satisfactory for attachment of the first azalactam unit, a dibromobutane coupling system proved unreactive for the second. Couplings with unmethylated, methylated, and benzyloxycabronyl-protected azalactams were examd. using (E)-1,4-dibromobutene and (Z)-1,4-dichlorobutene as the bridging unit. Employing the latter, coupling the first N-methylated azalactam with potassium bis(trimethylsilyl)amide as the base, and then the second with bis(trimethylsilyl)amide-sodium hydride as the base system, provided a satisfactory synthetic outcome. Hydrogenation under acidic conditions gave the unsym. structures hopromine, hoprominol and hopromalinol, as well as the more simple and sym. alkaloid, homaline.

Morphological Expression of KIT Positive Interstitial Cells of Cajal in Human Bladder

PURPOSE: We investigated the 3-dimensional morphological arrangement of KIT positive interstitial cells of Cajal in the human bladder and explored their structural interactions with neighboring cells.MATERIALS AND METHODS: Human bladder biopsy samples were prepared for immunohistochemistry/confocal or transmission electron microscopy.RESULTS: Whole mount, flat sheet preparations labeled with anti-KIT (Merck, Darmstadt, Germany) contained several immunopositive interstitial cell of Cajal populations. A network of stellate interstitial cells of Cajal in the lamina propria made structural connections with a cholinergic nerve plexus. Vimentin positive cells of several morphologies were present in the lamina propria, presumably including fibroblasts, interstitial cells of Cajal and other cells of mesenchymal origin. Microvessels were abundant in this region and branched, elongated KIT positive interstitial cells of Cajal were found discretely along the vessel axis with each perivascular interstitial cell of Cajal associated with at least 6 vascular smooth muscle cells. Detrusor interstitial cells of Cajal were spindle-shaped, branched cells tracking the smooth muscle bundles, closely associated with smooth muscle cells and vesicular acetylcholine transferase nerves. Rounded, nonbranched KIT positive cells were more numerous in the lamina propria than in the detrusor and were immunopositive for anti-mast cell tryptase. Transmission electron microscopy revealed cells with the ultrastructural characteristics of interstitial cells of Cajal throughout the human bladder wall.CONCLUSIONS: The human bladder contains a network of KIT positive interstitial cells of Cajal in the lamina propria, which make frequent connections with a cholinergic nerve plexus. Novel perivascular interstitial cells of Cajal were discovered close to vascular smooth muscle cells, suggesting interstitial cells of Cajal-vascular coupling in the bladder. KIT positive detrusor interstitial cells of Cajal tracked smooth muscle bundles and were associated with nerves, perhaps showing a functional tri-unit controlling bladder contractility.

Amplitude and Phase Controlled Reflectarray Element Based on an Impedance Transformation Unit

An architecture to simultaneously affect both amplitude and phase control from a reflectarray element using an impedance transformation unit is demonstrated. It is shown that a wide range of control is possible from a single element, removing the conventional necessity for variable sized elements across an array in order to form a desired reflectarray far-field pattern. Parallel plate waveguide measurements for a 2.2 GHz prototype element validate the phase and amplitude variation available from the element. It is demonstrated that there is sufficient control of the element's reflection response to allow Dolph-Tschebyscheff weighting coefficients for major-lobe to side-lobe ratios of up to 36 dB to be implemented.