bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutritional assessment of elderly Japanese nursing home residents of differing mobility using anthropometric measurements, biochemical indicators and food intake
Authors: Tajima Orie , Nagura Eiichi , Ishikawa‐Takata Kazuko , Furumoto Satoko , Ohta Toshiki
Published: April 2004

Background:  Awareness and evaluation of individual nutritional status are required for optimal support of the elderly population. A Japanese Anthropometric Reference Data ( JARD 2001) was established as a new gold standard, however, its utility for very frail elderly with differing mobility and the relationship with biochemical parameters and food intake remains unclear. The purpose of this study was to investigate the possible relationship between nutritional status and mobility deficits in Japanese nursing home residents, and to compare the ability of JARD 2001 to detect malnutrition with other indicators.

Methods:  In 130 Japanese nursing home residents (26 men, 104 women; mean age 82.2 ± 9.0 years), anthropometric measurements (body mass index, mid‐arm circumference, triceps skinfold thickness and calf circumference), serum markers (albumin, total protein, prealbumin, retinol binding protein, total cholesterol, HDL‐cholesterol, triglyceride, white blood cells, erythrocyte, hemoglobin and lymphocytes) and food intake were assessed. The nutritional indicators were compared among categories according to severity of mobility deficits, and the ability to detect malnutrition was examined in each parameter.

Results:  The bedridden elderly had significantly lower nutritional indicators, including anthropometric indexes, albumin, HDL‐cholesterol and food intake, compared with other elderly who can move with or without a wheelchair. When protein‐energy malnutrition was defined as below 1.2 g/kg/day protein intake, 36.7% of the residents were considered to have an intake deficiency. The JARD 2001 was better able to identify the deficiency than albumin level in the independent and the chair‐bound, while albumin could detect the malnourished subjects more sensitively than anthropometric measurements in the bedridden.

Conclusion:  Poor nutritional indicators could relate with mobility deficits among institutionalized Japanese frail elderly. The ability of indicators to detect malnutrition diverged with the severity of mobility deficits. The JARD 2001 criteria should be adopted for the elderly with at least an ability to move about by wheelchair, and appropriate anthropometric reference standards for very frail people must be reconsidered.
A cross‐sectional study of buccal cervical sensitivity in UK general dental practice and a summary review of prevalence studies
Authors: Rees JS , Addy M
Published: April 2004

Abstract: 

Aim:  The initial aim of this study was to establish the prevalence of dentine hypersensitivity (DH) in a cross‐sectional study of patients visiting general dental practitioners in the UK over a period of one calendar month.

Methods:  Eighteen dental practitioners examined 5477 patients over a period of one calendar month, and patients who were diagnosed with DH were questioned further about their occupation and smoking habits. The amount of buccal gingival recession associated with the sensitive teeth was also recorded, as was the presence of periodontal disease.

Results:  One hundred and fifty‐two patients were diagnosed as having DH, giving a prevalence figure of 2.8%. The commonest teeth affected were the first molars and premolars, and the commonest initiating factor was cold drinks. A tendency for a greater number of DH teeth was also found for patients with periodontal disease who also smoked. There was also a tendency for the patients with DH teeth to come from higher social groups.

Conclusion:  At the time of conducting this study, the European Federation of Periodontology had not recommended that sensitive teeth associated with periodontal disease and treatment be termed root sensitivity (RS). The title of this paper was therefore chosen to reflect this decision, and the data represent teeth both within and between subjects with DH and RS.
Smoking, periodontal disease and the role of the dental profession
Authors: Hilgers KK , Kinane DF
Published: April 2004

Abstract:  Epidemiological investigations support a firm relationship between smoking and periodontal disease. The likely benefits of smoking cessation programmes are considerable for periodontal disease, cancers and nearly all chronic systemic diseases. The mechanisms by which smoking may influence the development and progression of periodontal disease are as yet unclear, but may include changes in the vasculature, the immune and inflammatory systems, tissue oxygenation and the healing processes. Unfortunately, although dental professionals have more opportunities to encourage smokers to quit (most people visit their dentist more frequently than their doctor), dentists claim that they are not well informed on this subject. The purpose of this review is to describe the evidence for a link between smoking and periodontal disease, the possible pathology induced by smoking on the periodontal tissues and its impact on therapy, and to outline the smoking cessation techniques that are currently available.
Characteristics of patients with severe root resorption
Authors: Sameshima GT , Sinclair PM
Published: April 2004

Structured Abstract

Author – Sameshima GT, Sinclair PM

Objectives – The purpose of this study was to compare a group of patients in whom all four maxillary incisors were resorbed at least 20% with a matched group.

Materials and Methods – Retrospective, case–control. Root resorption was measured on pre‐ and post‐treatment periapical radiographs collected from 868 patients treated in private practices in southern California. Diagnostic and treatment factors were recorded, and vertical and horizontal apical movement calculated from cephalometric films. Root shape was assessed with a six‐object non‐parametric rating system. From this patient population, 25 patients were found who had >20% root resorption on all four maxillary incisors. A case control group without severe root resorption matched by sex, treating office, age at start, ethnicity, and duration of treatment was created with two controls for each severe case.

Results – There were no statistically significant differences found for extractions, use of Class II and finishing elastics, transverse treatments, overjet, overbite, vertical, tooth length, habits, and root shape. Higher estimated risk was found for abnormal root shape for both maxillary incisors, and tongue thrust. Horizontal apical displacement was not significantly different (p = 0.07) but severely resorbed incisors were retracted an average of one millimeter further.

Conclusions – Twenty‐five of 868 patients were found to have over 20% of all four of their maxillary incisors resorbed. This is <3% of the total patients. Matching this group by sex, ethnicity, office, treatment time, and age greatly reduced the number of factors that would differentiate these patients from 50 who did not get severe root resorption. We conclude that horizontal root displacement, tongue thrust, and abnormal root shape may have higher estimated risk but interoffice variability and treatment time cannot be underestimated.
Engineering of Superconductive Ceramics
Authors: Rokhvarger Anatoly E. , Chigirinsky Lubov A.
Published: April 2004

Recently awarded U.S. patents and proven in the lab, our versatile high temperature superconductor (HTS) ceramic nanotechnology utilizes a novel material formulation of nanosize HTS ceramic powder and of multi-purpose silicone polymer additive. Inexpensive ceramic-silicone processing (CSP) of superconductor wire and other adhesion substrate coated materials, electronics and various bulk materials resulted in electricity throughput of up to 500× copper wire throughput at significantly decreased operating voltage and energy losses. All HTS-CSP materials have the required mechanical properties and durability and can be conveyor manufactured in any size and shape, including continuous flexible multi-strand round wire and electronics.
Interfacial Bond Stress Relationship for Gullwing Solder Joints
Authors: Meekisho L. L. , Nelson-Owusu K.
Published: April 2004

Lead frame bond connections are susceptible to bond shear and peeling stress failure due to high thermomechanical loads resulting from the combined effects of thermal and vibration effects. Solder joint integrity has also been found to be highly dependent on the solder joint configuration, which, in turn, is determined by bond pad size, the alloy material, and the lead frame geometric details. This study considers the complete joint configuration in formulating the expression for bond stress. A new bond stress equation is proposed to predict the solder joint peeling stress at the interface between gullwing lead-frame and the solder layer. The proposed method considers the complete solder joint subjected to combined thermomechanical forces. Prior studies utilized symmetry conditions across the joint.
Optimum Gullwing Fillet Solder Joint Under Thermomechanical Forces
Authors: Meekisho L. L. , Nelson-Owusu K.
Published: April 2004

The final shape of a solidified solder fillet joint from a reflow process is determined by process parameters and the solder alloy’s physical properties, including surface tension, density, gravity, and wetting angles. This work investigates the influence of surface tension at the solder-atmosphere interface; gravitational effects on the solder, and the influence of wetting angles on the mechanical response of the solder joint when subjected to thermomechanical loads. The predicted optimum fillet shape with minimum fillet area corresponded to the case where the ratio of gravity-to-surface tension forces is almost zero, and wetting angles, θ1 and θ2 being 90 deg. Results from this study suggest that, the influence of gravity on the molten solder geometry is negligible and hence can be assumed to be inconsequential to solder joint reliability issues.
An Improved Analytical Model for Time-Dependent Shearing Deformation in Area-Array Interconnects
Authors: Shakya S. , Heinrich S. M. , Lee P. S.
Published: April 2004

An improved time-dependent analytical model is developed for predicting the maximum shearing displacement in an area-array electronic assembly under global thermal mismatch loading. The thermal loads are assumed to be uniform within the component and substrate, with both step-function and sinusoidal temperature histories being considered. The time-dependent effects in the array’s shear deformation are introduced in an approximate manner by modeling the interconnect material (solder) as a temperature-independent linear viscoelastic material. The viscoelastic constitutive law used for the solder is that of a three-parameter viscoelastic standard solid in distortion and an elastic solid in the hydrostatic mode. In the authors’ previous work the steady-state shear force in the joints was assumed to vary sinusoidally with a frequency-independent amplitude. This assumption has been relaxed in the present study, leading to improved accuracy. All results have been derived as closed-form correction factors to be applied to the easily calculated unconstrained shear displacement to obtain the maximum shear displacement. All the correction factors depend on prescribed geometric and material parameters of the component, substrate, and joints. The results have been presented in the form of dimensionless plots to aid in the analysis or design process, thereby providing convenient alternatives or supplements to time-consuming and expensive finite element analyses of entire assemblies.
Failure Analysis of Miniature Solder Specimen
Authors: Wei Y. , Chow C. L. , Fang H. E. , Neilsen M. K. , Lim T. J. , Lu W.
Published: April 2004

The effects of specimen geometry size on the behavior of 63Sn-37Pb solder are investigated both experimentally in the laboratory and analytically with finite-element simulations. The simulations are achieved by developing a constitutive model for solder which couples viscoplasticity with a unified damage theory. The unified damage theory is characterized by a damage surface in strain space which separates fatigue damage from inelastic damage. The damage evolution equations are derived within the framework of irreversible thermodynamics. A series of uniaxial tension, tensile creep, and strain-controlled fatigue experiments are performed to obtain material parameters for the solder damage model. The solder damage model is then implemented into a finite element code and used to simulate a uniaxial tension test on a miniature specimen and on a standard ASTM specimen (ASTM Standards, 1999, “Tension Testing of Metallic Materials,” ASTM E8-78). Predictions from these simulations are then compared with each other and with experimental results in order to examine microstructure size effects.
The Peeling Moment–A Key Rule for Delamination Resistance in I.C. Assemblies
Authors: Moore Thomas D. , Jarvis John L.
Published: April 2004

The peeling stress near the free edge of a bimaterial beam under uniform temperature change creates a moment which causes both layers to have identical curvatures at the interface. A new formula from beam theory is given for this Peeling Moment. A beam with a negative Peeling Moment resists delamination at the free edge. A physical explanation for the moment is developed; the sign of the Peeling Moment is also the determinant of the location of the equivalent centroid of the bimaterial beam. This provides a valuable new rule for designing resistance to thermomechanical delamination of a bimaterial structure.
Controlled Fracture of Nonmetallic Thin Wafers Using a Laser Thermal Shock Method
Authors: Elperin T. , Rudin G.
Published: April 2004

We developed a theoretical model of a novel thermal laser shock method for separation of glass and glass-ceramic wafers into chips. The suggested model allowed us to determine the operating parameters of the device for wafer splitting. The investigated method involves two stages: 1) formation of a surface (blind) microcrack (or a grid of surface microcracks) using a double thermal shock method, and 2) splitting the cracked wafer into chips along the microcrack contour by applying small bending stresses. The emphasis was given to splitting of thin wafers with the thickness less than 1 mm. The latter process is more involved because of the undesirable spontaneous transition of a surface microcrack into a through crack.
Time Integration Algorithm for a Cyclic Damage Coupled Thermo-Viscoplasticity Model for 63Sn-37Pb Solder Applications
Authors: Yang Xianjie , Chow C. L. , Lau K. J.
Published: April 2004

In this paper, a semi-implicit time integration scheme has been developed for a damage-coupled constitutive model to characterize the mechanical behavior of 63Sn-37Pb solder material under thermo-mechanical fatigue (TMF) loading. The scheme is developed to provide an efficient numerical procedure of integration and iteration for calculating stress and other associated state variables within a strain-driven format. In particular, a novel Newton-Raphson iteration algorithm for the damage coupled constitutive material model involving von Mises viscoplastic potential function with nonlinear mixed hardening is formulated. An algorithmic tangent stiffness tensor is derived and the model is implemented numerically into a commercial finite element (FE) code ABAQUS through its user-defined material subroutine. Several numerical simulations are conducted for validation of the proposed algorithm.
Strategies for Workload Balancing in Cluster-based Image Databases
Authors: Drews F. , Ecker K. , Kao O. , Schomann S.
Published: April 2004

Systems for the archival and retrieval of images are used in many areas, for example medical applications or news agencies. The technique of dynamic image analysis and comparison enables a detailed search for important image elements such as persons and objects. But it also requires large computational resources. Therefore, we developed a cluster-based architecture for an efficient storage and comparison of archived images. The initially even, size-based distribution of images over the cluster nodes is distorted, when the user excludes images from further consideration by applying combined a-priori and dynamically extracted features. This creates the necessity of utilisation of workload balancing strategies, which consider the specific requirements of the image retrieval problem. For efficiently solving this problem we developed a formal problem specification and three strategies – LPTR, RBS and Simulated Annealing – for workload balancing. The reduction of the system response time due to successful load balancing is evaluated by series of experimental measurements.
SELF-STABILIZING MAXIMAL k-DEPENDENT SETS IN LINEAR TIME
Authors: GAIRING MARTIN , GODDARD WAYNE , HEDETNIEMI STEPHEN T. , JACOBS DAVID P.
Published: April 2004

In a graph or network G=(V,E), a set S⊆V is k-dependent if no node in S has more than k neighbors in S. We show that for each k≥0 there is a self-stabilizing algorithm that identifies a maximal k-dependent set, and stabilizes in O(kn) moves, where n is the number of nodes. An interesting by-product of our paper is the new result that in any graph there exists a set that is both maximal k-dependent and minimal (k+1)-dominating. The set selected by our algorithm, in fact, has this property.
AN INTEGRATED BPMS FRAMEWORK FOR AUTOMOTIVE PART DEVELOPMENT
Authors: CHOI BYOUNG K. , YOO SEOCK K.
Published: April 2004

In recent years, car makers are relying more heavily on global sourcing of supplies while automotive suppliers are going through a rapid global consolidation process, which requires automotive suppliers develop parts in shorter time at lower cost with higher quality. To meet these challenges, automotive suppliers need a well-established information system strategy together with a BPMS (business process management system) framework tailored to them. In this paper, a workflow-based BPMS framework for automotive part development is proposed together with an information system strategy. Component technologies for developing such a BPMS are available, but the gap is in methodologies for developing it. This paper aims to fill this gap.
DIFFERENT APPROACHES IN MULTIPLE-CRITERIA OPTIMIZATION USING THE TAGUCHI METHOD: A CASE STUDY IN A COLD HEADING PROCESS
Authors: MILANI A. S. , EL-LAHHAM C. , NEMES J. A.
Published: April 2004

Real life engineering problems usually require the satisfaction of different, potentially conflicting criteria. Design optimization, on the other hand, based on the conventional Taguchi method cannot accommodate more than one response. However, by the use of the overall evaluation criterion approach, the method can be applied to multiple-criteria optimization problems. This paper presents the use of different utility function methods as well as a multiple attribute decision-making model in the multiple-criteria optimization of a cold heading process. Different aspects of each method are discussed and compared.
POWERTRAIN MACHINING FEATURE IDENTIFICATION
Authors: PARK SANGCHUL
Published: April 2004

Presented in this paper is a procedure to identify machining features of powertrain components. Machining feature recognition is one of the most important steps for machining process planning. In the case of powertrain components, the first step is to compare a machined model (finished part model) and the corresponding rough part model to identify the volume which should be removed from the rough part model. In regard to the comparison, the most intuitive idea is to use a 3D BOOLEAN operation. Although this approach looks fine, it might not take advantage of the inherent attributes of powertrain component machining. This paper focuses on two important attributes of powertrain machining: (1) a machined model and the corresponding rough part model are very similar and have many identical faces and (2) a rough part model always contains the machined model. Based on these two attributes, we develop an efficient procedure for identifying powertrain machining features. Since the proposed procedure employs well-known 2D geometric algorithms instead of 3D BOOLEAN operations, it is very efficient and robust.
VISUAL INFORMATION ACQUISITION IN VERTEBRATE RETINA
Authors: YANG SIMON X.
Published: April 2004

In this paper, visual information acquisition in vertebrate retina is investigated using a novel neural network model. The neural network is based on the neural anatomy and function of retinal neurons in tiger salamander and mudpuppy. All the main types of retinal neurons are modeled, and their response characteristics are studied. The objective is to model the information acquisition in vertebrate retina with a simple yet effective neural network architecture. The model predictions on the main characteristics of retinal neurons are in agreement with the neurophysiological data. This study not only offers insight into the biological strategy and mechanism on the early visual information acquisition in vertebrate retina, but also has potential industrial applications such as VLSI chip design for efficient visual and movement sensors.
MICRO CAPILLARY ARRAY ELECTROPHORESIS CHIP BY MOVING MASK LIGA TECHNOLOGY
Authors: YOU HUI , SHINOHARA SHOUJI , ENAMI KENNICHI , SHIBATA SHINSUKE , TABATA OSAMU , SHIRAISHI HARUKI , UEDA MASANORI , BABA YOSHINOBU
Published: April 2004

The concept and the fabrication process of a micro capillary array electrophoresis (μ-CAE) for DNA analysis were stated. The chip was mainly made of plastic and fabricated by the innovatory LIGA technology which included moving mask deep X-ray lithography, electroplating and hot embossing, and assembled by an adhesive bonding, in which the adhesive layer solidified and formed firm bond under UV exposure. The micro channel array with high aspect ratio is the key part, whose wall should have a slight inclination to ensure the demoulding. It was demonstrated that moving mask deep X-ray lithography (M2DXL) technology could successfully control the inclination and enabled to integrate micro optical components such as micro lens into the chip, which improved detection performance greatly. The fabrication process was experimented and some initial prototype chips have been obtained. Fluidic test and electrophoresis test with laser-induced fluorescence detection has been done on the prototype. The results confirm that the μ-CAE by moving mask LIGA process is realizable and it has great potential in high-throughput, which may lead to ultra-fast DNA analysis.
INFORMATION ACQUISITION IN STEREO VISION: FROM DISPARITY MAP TO SCENE DESCRIPTION
Authors: WANG ZENG-FU
Published: April 2004

This paper addresses the problem of stereo vision from a new viewpoint. The problems of both depth determination and scene segmentation are considered as a whole. Based on the facts from psychophysical observations, we propose a multi-layered representation model for stereo vision and show that the problems of both depth determination and image segmentation can be solved simultaneously. The constraints and algorithms for formulating the model are described. A mechanism of interaction between depth perception and surface completion is used to integrate imperfect disparity data and image data to get the correct solution about depth maps of a scene. The experimental results show that the model is a useful as well as an effective one.
Culture and Aggression—From Context to Coercion
Authors: Bond Michael Harris
Published: April 2004

This article is an attempt to study the neglected linkages between culture and aggression. It does so by conceptualizing culture as a set of affordances and constraints that channel the expression of coercive means of social control by self and others. All cultural systems represent solutions to the problems associated with distributing desired material and social resources among its group members while maintaining social order and harmony. Norms are developed surrounding the exercise of mutual influence in the process of resource allocation, favoring some and marginalizing others. Violations of these norms by resource competitors are conceptualized as “aggressive” behaviors and stimulate a process of justified counterattack, escalating the violence. The current data from both societal-level and individual-level studies are examined and integrated in light of this organizing framework, and future studies are proposed to explore the interface between culture and aggression more productively.
A Look-Ahead Dispatching Method for Automated Guided Vehicles in Automated Port Container Terminals
Authors: Kim Kap Hwan , Bae Jong Wook
Published: April 2004

To reduce delay in ship operations in automated container terminals, it is important to make different types of container handling equipment to operate harmoniously during this operation. Delivery operations by automated guided vehicles (AGVs) play an important role for synchronizing operations of container cranes with yard cranes. This study discusses how to dispatch AGVs by utilizing information about locations and times of future delivery tasks. A mixed-integer programming model is provided for assigning optimal delivery tasks to AGVs. A heuristic algorithm is suggested for overcoming the excessive computational time needed for solving the mathematical model. Objective values and computational times of the heuristic algorithm are compared with those of the optimizing method. To test performances of the heuristic algorithm, a simulation study is performed by considering the uncertainties of various operation times and the number of future delivery tasks for looking ahead. Also, the performance of the heuristic algorithm is compared with those of other dispatching rules.
A Graphic Nomogram for Warfarin Dosage Adjustment
Authors: Dalere Gloriann M. , Coleman Robert W. , Lum Bert L.
Published: April 2004

We assessed the ability of a graphic nomogram to adjust steady‐state warfarin dosages and to predict international normalized ratios (INR) after a dosage change, compared with an anticoagulation clinic pharmacist and a Bayesian regression computer program. Study subjects were 108 men and 3 women receiving warfarin anticoagulation. In all patients the median absolute errors in predicted INR values for the nomogram, computer program, and pharmacist were 0.33, 0.46, and 0.48, respectively. The nomogram was significantly more precise than both other methods (p=0.036). In a subset of 50 patients who required dosage reductions, the median absolute INR prediction errors for the nomogram, computer program, and pharmacist were 0.35, 0.54, and 0.48 respectively. The nomogram was significantly more precise than the pharmacist (p=0.005) and computer (p=0.002). The ability to provide more precise dosage reductions of warfarin may be of clinical importance in light of current recommendations for higher‐intensity warfarin therapy and maintenance of higher INR values. Prospective validation of the performance of this nomogram in a routine clinical setting is warranted.
Synthesis of Nitro‐Substituted Polyfunctional Biphenyls by Negishi Cross‐Coupling of o‐Nitroarylzinc Reagents
Authors: Sapountzis Ioannis , Dube Henry , Knochel Paul
Published: April 2004

The iodine‐magnesium exchange reaction allows the preparation of polyfunctional arylmagnesium species bearing a nitro group in the ortho‐position. After transmetalation to the corresponding arylzinc compound, these organometallics undergo a palladium‐catalyzed Negishi cross‐coupling with various aryl iodides to provide polyfunctional biphenyls bearing nitro groups in moderate to good yields.
Calbindin‐immunoreactive neurones in the ovine rumen
Authors: Pfannkuche Helga , Schellhorn Corinna , Schemann Michael , Gäbel Gotthold
Published: April 2004

In small laboratory animals, such as guinea pigs, immunoreactivity for the calcium‐binding protein calbindin (CALB) can be used to distinguish functionally different classes of myenteric neurones. The rumen of sheep is a highly specialized gastrointestinal region, and the control of its functions requires specific intrinsic innervation patterns. The aim of this study was to neurochemically identify and characterize CALB‐positive myenteric neurones of the ovine rumen. Therefore, we performed quadruple immunohistochemistry against CALB, substance P (SP), vasoactive intestinal peptide (VIP), and nitric oxide synthase (NOS) using whole‐mount preparations of the ruminal myenteric plexus. On average, 3 ± 2 and 1 ± 0.4 myenteric neurones/ganglion were CALB‐immunoreactive in suckling lambs and adult sheep, respectively. These neurones had Dogiel type‐I morphology. Most of them (89.2% ± 8.7% and 71.7% ±44.8% in suckling lambs and adult sheep, respectively) did not colocalize any of the other antigenes. Since it has been shown in previous studies that ruminal myenteric neurones are immunoreactive for either choline acetyltransferase (ChAT) or NOS, we defined neurones which were CALB‐positive and NOS‐negative as CALB/ChAT. The other CALB‐positive neurones were encoded CALB/NOS/±VIP (10.3% ± 9.3% and 26.7% ± 46.2% in suckling lambs and adult sheep, respectively) or CALB/ChAT/SP (0.5% ± 1.0% and 1.7% ± 1.9% in suckling lambs and adult sheep, respectively). We used cryostat sections of the ruminal wall to analyze the projections of the CALB‐positive neurones. CALB‐immunoreactive somata were exclusively located within the myenteric plexus. CALB‐immunoreactive nerve fibers were found primarily in the lamina propria of the ruminal papillae. We conclude that CALB‐positive myenteric neurones within the ovine rumen project to the epithelium; however, their functional role remains to be investigated. Anat Rec Part A 278A:528–532, 2004. © 2004 Wiley‐Liss, Inc.
Partitioning of model toxins to hydrophobically terminated DAB dendrimers
Authors: King M. , Duan X. , Sheardown H.
Published: April 2004

Dendrimers are attractive in biological and biomedical applications due to the similarity in their molecular size to biologically relevant molecules and the large number of chain ends available functionalization. In the current work, we examined the potential of diamino butane (DAB) dendrimers functionalized with long alkyl chains as partitioning agents for hydrophobic toxins for use as a prefiltering stage in a bioartiticial liver. DAB dendrimers of various generations that had been previously fully modified with palmitoyl chloride were obtained. A study of the kinetics of partitioning of acetylsalicylic acid (ASA) suggested that while significant toxin removal occurred in 30 s, although a slight time dependent increase in removal was noted up to 60 minutes. The partitioning of 6 hydrophobic toxins from aqueous solution to the modified dendrimers in 30 minutes was examined. The results demonstrated that a number of factors, including the pKa of the toxin, its octanol water partitioning coefficient and molecular size contributed to the level of toxin removal. Toxin removal on a molar basis increased with increasing dendrimer generation for all toxins, with the modified G5 dendrimers partitioning 50–100 toxin molecules in most cases. Dendrimer modification with C4 alkyl chains rather than Cl5 chains significantly decreased toxin removal, although chains longer than C10 seemed to partition equal amounts of toxins. The results of the study demonstrate that water‐soluble dendrimers modified with hydrophobic end groups may be useful for the removal of toxins from the blood in a prereaction step for a bioartificial liver, but that a better understanding of the molecular mechanisms of removal may be necessary before it is possible to predict the levels of toxin removal. © 2004 Wiley Periodicals, Inc.
Organic Spin Clusters: Annelated Macrocyclic Polyarylmethyl Polyradicals and a Polymer with Very High Spin S=6–18
Authors: Rajca Andrzej , Wongsriratanakul Jirawat , Rajca Suchada , Cerny Ronald L.
Published: April 2004

Synthesis and magnetic studies of annelated macrocyclic polyradicals and a related high‐spin polymer with macrocyclic repeat units are described. Polyarylmethyl polyether precursors to the polyradicals and the related polymer are prepared by using Negishi cross‐coupling of difunctionalized calix[4]arene‐based macrocycles. The three lowest homologues, with high degree of monodispersity, are tetradecaether (14‐ether) 3‐(OCH3)14, octacosaether (28‐ether) 4‐(OCH3)28, and dotetracontaether (42‐ether) 5‐(OCH3)42, in which 2, 4, and 6 calix[4]arene‐based macrocycles are annelated to the center macrocycle, respectively. The evidence for their annelated structures (ladder connectivities) is based upon FAB‐MS and the 1H NMR based end‐group analysis. The absolute masses (4–12 kDa) were determined by FAB‐MS and GPC/MALS. Small angle neutron scattering (SANS) provides the radii of gyration of 1.7, 2.0, and 3.2 nm for 4‐(OCH3)28, 5‐(OCH3)42, and polymer 6‐(OCH3)n, respectively. The corresponding polyarylmethyl polyradicals 3 and 4, and polymer 6 possess average values of S≈6–7, S≈10, and S≈18, respectively, as determined by SQUID magnetometry and numerical fits to linear combinations of Brillouin functions. The quantitative values of magnetization at saturation and of magnetic susceptibilities indicate that about 40–60 % of unpaired electrons are present at low temperatures (T=1.8–5 K). For polyradical 3, the variable temperature magnetic data are fit to the Heisenberg Hamiltonian based model. The variable magnetic field data at low temperatures are also fit to a percolation‐based model for organic spin cluster, with random distribution of chemical defects, and ferromagnetic versus antiferromagnetic couplings, providing quantitative agreement between the experiment and the theory. For polyradical 3 (with S≈6–7), annealing at room temperature for 0.5 h leads to a polyradical with S≈5.
CD8α‐ and Langerin‐negative dendritic cells, but not Langerhans cells, act as principal antigen‐presenting cells in leishmaniasis
Authors: Ritter Uwe , Meißner Anja , Scheidig Christina , Körner Heinrich
Published: April 2004

In the early phase of leishmaniasis three types of potential antigen‐presenting cells, including epidermal Langerhans cells (LC), dermal dendritic cells (DC) and inflammatory DC, are localizedat the site of infection. Therefore, it has been a central question which cell type is responsible for the initiation of a protective immune response. In the early stage of an anti‐Leishmania immune response, detectable Leishmania major antigen was localized in the paracortex of the draining lymph nodes (LN). Characterization of antigen‐positive cells showed that L. major co‐localized with DC of a CD11c+ CD8α– Langerin– phenotype. To determine the area of antigen uptake, dermis or epidermis, and to further define the type of antigen‐transporting cells, L. major was inoculated subcutaneously and concurrently LC were mobilized with fluorescein isothiocyanate (FITC). After 3 days, DC carrying L. major antigenwere always FITC–, indicating a dermal and not an epidermal origin. Moreover, addition of L. major antigen to ex vivo isolated CD8α– and CD8α+ DC fromthe draining LN of L. major‐infected C57BL/6 mice demonstrated that both DC subpopulations were able to stimulate antigen‐specific T cell proliferation in vitro. Without addition of exogenous antigen only the CD8α– Langerin– DC were capable of stimulating antigen‐specific T cell proliferation. Thus, we demonstrate that CD8α– Langerin– DC and not LC are the basis of the protective immune response to intracellular L. major parasites in vivo.
Ultra‐sensitive class I tetramer analysis reveals previously undetectable populations of antiviral CD8+ T cells
Authors: Barnes Eleanor , Ward Scott M. , Kasprowicz Victoria O. , Dusheiko Geoffrey , Klenerman Paul , Lucas Michaela
Published: April 2004

A major breakthrough in cellular immunology has been the development of HLA class I tetramers to analyze CD8+ T cell responses. However, in many situations, including persistent virusinfection, specific T cell responses are rarely detected using this technology. This raises the question of whether such responses are ‘deleted’ (or ‘exhausted’) or present below the conventional detection limit for class I tetramer staining. In particular, persistent hepatitis C virus (HCV) infection is characterized by very weak or apparently absent specific CD8+ T cell responses, even though they are readily detectable in acute disease. Therefore, we assessed the use of anti‐PE‐labeled magnetic beads to enrich tetramer‐positive HCV‐specific T cells and identify previously undetectable populations. Using the enrichment technique, HCV‐specific T cells could be detected in the majority of infected individuals, whereas these responses were not detected using conventional tetramer staining (8/15 vs. 1/15; p=0.01). Magnetic enrichment could reliably detect very rare HCV‐specific responses at frequencies of >0.0011% of CD8+ T cells (∼1/million PBMC), and phenotypic analysis of these rare populations was possible. Therefore, this direct ex vivo technique revealed the persistence of very low frequencies of virus‐specific CD8+ T cells during chronic virus infection and is readily transferable to the study of other viral, self‐ or tumor‐specific T cells.
Involvement of filamentous actin in setting the threshold for degranulation in mast cells
Authors: Tolarová Helena , Dráberová Lubica , Heneberg Petr , Dráber Petr
Published: April 2004

Previous studies using cytochalasins and latrunculin B, inhibitors of actin polymerization, showed that filamentous (F)‐actin had a negative regulatory role in Fcϵ receptor I (FcϵRI) signaling. How F‐actin is involved in regulating the activation of mast cells is unknown. In this study we investigated the role of F‐actin in mast cell activation induced by aggregation of the glycosylphosphatidylinositol (GPI)‐anchored proteins Thy‐1 and TEC‐21, and compared it to activation via FcϵRI. Pretreatment of rat basophilic leukemia cells with latrunculin B inhibited the Thy‐1‐induced actin polymerization and elevated the Thy‐1‐mediated secretory and calcium responses. Inhibition of actin polymerization followed by Thy‐1 aggregation resulted in an increased tyrosine phosphorylation of Syk, phospholipase Cγ (PLCγ), Gab2 and linker for activation of T cells (LAT) adapters, and some other signaling molecules. Enzymatic activities of phosphatidylinositol 3‐kinase, PLCγ, and phosphatase SHP‐2 were also up‐regulated, but tyrosine phosphorylation of ezrin was inhibited. Similar changes were observed in FcϵRI‐activated cells. Significant changes in intracellular distribution, tyrosine phosphorylation, and/or enzymatic activities of signaling molecules occurred in latrunculin‐pretreated cells before cell triggering. The combined data suggest that actin polymerization is critical for setting the thresholds for mast cell signaling via aggregation of both FcϵRI and GPI‐anchored proteins.
Recognition of HLA‐A3 and HLA‐A11 by KIR3DL2 is peptide‐specific
Authors: Hansasuta Pokrath , Dong Tao , Thananchai Hathairat , Weekes Michael , Willberg Christian , Aldemir Hatice , Rowland‐Jones Sarah , Braud Veronique M.
Published: April 2004

The recognition of MHC class I molecules by killer cell immunoglobulin‐like receptors (KIR) is central to the control of NK cell function and can also modulate the CTL activation threshold. Among KIR receptors, KIR3DL2 is thought to interact with HLA‐A3 and ‐A11, although direct evidence has been lacking. In this study, we show that HLA‐A3 and ‐A11 tetramers specifically bind to KIR3DL2*001 transfectants and that this recognition is peptide‐specific. Single amino acid substitutions in the nonamer peptide underline a critical role for residue 8 in recognition of KIR3DL2. However, the role of this interaction in vivo still remains to be established.
Flammability of oil‐based painted gypsum wallboard subjected to fire heat fluxes
Authors: Mowrer Frederick W.
Published: April 2004

The flammability of painted gypsum wallboard (GWB) exposed to fire heat fluxes is investigated. GWB samples coated with multiple layers of alkyd/oil‐based paint are subjected to constant incident heat fluxes of 35, 50 and 75 kW/m2 in the Cone Calorimeter for periods of 5, 10 and 15 min. A number of coats of alkyd/oil‐based interior semi‐gloss enamel paint, including 1, 2, 4, 6 and 8 coats, are applied over a single coat of oil‐based primer to the exposed surface of 16 mm (5/8 in.) thick type X GWB. Unpainted type X GWB is also evaluated under the same exposure conditions. The potential for upward flame spread based on the Cone Calorimeter results is evaluated. The occurrence of paint ‘blistering’ is observed to have a significant effect on the time to ignition and consequently on the potential for upward flame spread. Further work is needed to evaluate the conditions under which ‘blistering’ will occur and its effects on the potential for surface flame spread on painted gypsum wallboard. Copyright © 2004 John Wiley & Sons, Ltd.
A theory for flame extinction based on flame temperature
Authors: Quintiere J. G. , Rangwala A. S.
Published: April 2004

The extinction and suppression of diffusion flames is examined theoretically. The effects of oxygen reduction and external heat flux are examined compared to data in the literature. An application of extinction in compartment fires is also examined. The theory developed is based on a critical flame temperature, and that theory includes transient effects and the addition of water as well. Copyright © 2004 John Wiley & Sons, Ltd.
Stability of lightweight structural sandwich panels exposed to fire
Authors: Cooke Gordon M. E.
Published: April 2004

Sandwich panels comprising thin flat metal faces and a lightweight structural core are increasingly used as walls and ceilings in buildings where their long‐span capabilities, high thermal insulation, clean design, rapid installation and low maintenance often make them the preferred choice of designers and building owners.

The fire performance of sandwich panels can be excellent if the correct core material is used and, importantly, if the metal facings are adequately restrained. For example, fire resistance in excess of 2 h can be easily achieved using panels with sheet steel faces and a non‐combustible rock wool core.

Where sandwich panels are used in cold stores there is the potential problem of cold‐bridging between the facings wherever there is a metallic through‐fixing, and this has led to designs which work well in normal conditions but allow panels to collapse very early when exposed to fire because the facings are not tied back to the supporting structure. Such collapse is a fire hazard to fire‐fighters as proven in the 1993 fire in the Sun Valley poultry factory in Hereford, United Kingdom in which two firemen lost their lives.

The paper describes what can happen if panel facings are not mechanically restrained with steel fastenings. It then introduces a fire safety engineering method for assessing the stability of ceiling sandwich panels exposed to fire. The method assumes that the ends of panels are restrained and the panel behaves as a catenary after delamination. The paper quantifies the variation of catenary force as fire develops and takes account of the initial beneficial sag which is present at the time of delamination. The method is currently being considered in the work of European committee CEN TC 127 on the development of rules for extended applications for construction products. Copyright © 2004 John Wiley & Sons, Ltd.
Fire resistance of structural components protecting escape routes
Authors: Thomas Geoff , Lloydd Delwyn
Published: April 2004

Generally, fire resistant structures are expected to survive a fire in an adjoining compartment. Some structures, such as floors, may be designed to provide time for the occupants to escape from compartments other than the one where the fire occurs. In the fire compartment smoke development governs the time available for egress. A common misconception is that the fire resistance rating (FRR), the time an assembly will survive in a test furnace, is the time available to escape. In small compartments such as those in residential accommodation their FRR is significantly longer than the times the assemblies would survive in real compartment fires. Some fire engineering designs for retrofitted accommodation buildings use FRR times for light timber frame walls and floors as the available egress time, which is unconservative.

The method of time equivalence can provide a prediction of the FRR required to survive a compartment burnout. The ratio of the total burning time of the fire to the time equivalent for the compartment and fuel load can be used to provide an estimate of the time taken for an assembly of given fire resistance to fail by multiplying the FRR by the ratio. Although this method is shown to be non‐conservative when a computer model of light timber frame wall assemblies is run using both realistic time‐temperature curves and the ISO‐834 standard fire test time‐temperature curve, it is more conservative than assuming that an assembly will last as long in a compartment fire as predicted by the FRR. Copyright © 2004 John Wiley & Sons, Ltd.
Bending and membrane action in concrete slabs
Authors: Gillie Martin , Usmani Asif , Rotter Michael
Published: April 2004

It has become apparent from the series of fire tests carried out at Cardington, UK that the response of steel‐concrete composite structures in fire conditions is largely governed by the behaviour of the reinforced concrete floor slabs. This paper obtains a detailed understanding of the strength of heated concrete floor slabs when subject to the combined bending and membrane forces that typically result from restrained thermal expansion. To analyse such slabs the computer program FEAST is used. Initially the behaviour of the floor slab in the Cardington frame under pure bending and pure membrane forces is described and explained. The paper then explores the effect that interaction between bending and membrane behaviour has on the strength of the slab when it is uniformly heated, heated with a linear thermal gradient and heated with the non‐linear thermal gradient observed during the Cardington tests. Finally, the effects of varying the area and location of the reinforcement in the slab are analysed. Copyright © 2004 John Wiley & Sons, Ltd.
Structural behaviour of an open car park under real fire scenarios
Authors: Zhao Bin , Kruppa Joël
Published: April 2004

During two successive European research projects involving CTICM (France), ARBED (Luxembourg) and TNO (Netherlands), several fire tests were performed on cars and on a real car park made of steel columns and steel beams connected to composite slabs. Although there has been a drastic increase of combustible product in cars, the experimental results have given convincing evidence that fire protection of the steel structure is not necessary to obtain overall stability.

Parallel to the above experimental investigations, numerical analysis was also performed in which the fire development, the heating of the structure and structural behaviour during the fire were studied with different numerical models. However, the present paper focuses mainly on the modelling of structural behaviour. It shows that the global structural behaviour (composite floor and steel column) subjected to localized heating from cars may be very accurately predicted by 3D modelling in which the lateral buckling of the steel beam, the membrane and diaphragm effects of the floor are taken into account.

In addition, the results of a parametric study are presented in which it is shown that the use of 3D modelling in the analysis leads to the possibility of building open car parks with more economical steel and concrete composite structures. Copyright © 2004 John Wiley & Sons, Ltd.