bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiphoton excited fabricated nano and micro patterned extracellular matrix proteins direct cellular morphology
Authors: Pins George D. , Bush Katie A. , Cunningham Lawrence P. , Campagnola Paul J. 
Published: April 2006

AbstractWe use multiphoton excited (MPE) photochemistry to fabricate patterned extracellular matrices (ECM) and to investigate the morphology of human dermal fibroblasts adhered to the resulting photocrosslinked linear structures of fibronectin (FN), fibrinogen (FG), and bovine serum albumin (BSA). These proteins were chosen to systematically investigate the roles of topography and ECM biochemistry on cell spreading, as fibroblasts bind directly to both FN and FG at RGD sites through known integrins, whereas BSA provides no comparable ECM cues for cell binding. MPE crosslinked patterns are created from parallel linear structures 600 nm in width, 200 μm in length, and spaced by either 10 or 40 μm. Immunofluorescence staining of FN and FG was used to assay the functionality of crosslinked proteins. The metrics of orientation, elongation, and cell perimeter were used to quantitate the resulting cellular behavior on the crosslinked protein patterns. These parameters all reflect statistical differences for cells on BSA, relative to the similar statistical behavior on fibronectin and fibrinogen. Cells on the BSA patterns are constrained by physical guidance and orientation between linear structures. In contrast, cells adhered on both FN and FG had a greater propensity to spread across adjacent structures, indicating the importance of cell matrix interactions. Focal adhesion staining of cells adhered to the protein structures revealed similar trends. These findings are consistent with our hypothesis that these crosslinked matrix protein structures are expected to direct cell adhesion and spreading and that the topography and ECM cues lead to different forms of guidance. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Identification of candidate antigen in Whipple's disease using a serological proteomic approach
Authors: Kowalczewska Malgorzata , Fenollar Florence , Lafitte Daniel , Raoult Didier 
Published: April 2006

AbstractWhipple's disease (WD) is a chronic multisystemic infection, caused by Tropheryma whipplei, a Gram‐positive rod. Recently, a reliable method has been developed for cultivating T. whipplei in vitro. This together with the availability of complete genome sequence of T. whipplei prompted us to initiate proteome analysis of T. whipplei. The objective of the present study was to identify candidate proteins for serological diagnosis of WD. Immunoreactivities of sera collected from 18 patients with WD were compared with those of 24 control subjects who did not have WD. For this, we used 2‐DE, immunoblotting, and MS. In total, we identified 23 candidate antigenic proteins. These included a subset of six proteins, each of which was found significantly more frequently in cases as compared to their controls. The remaining 17 proteins were found exclusively in cases. The methods we used in the current study enabled us to identify candidate antigens that, in our view, might be useful for serological diagnosis of WD.
Retreatment with rabbit anti‐thymocyte globulin and ciclosporin for patients with relapsed or refractory severe aplastic anaemia
Authors: Scheinberg Phillip , Nunez Olga , Young Neal S. 
Published: April 2006

SummaryThe management of patients with severe aplastic anaemia (SAA) who do not have a matched sibling donor and fail a course of horse anti‐thymocyte globulin (h‐ATG)/ciclosporin (CsA) is uncertain. Repeated courses of ATG‐based immunosuppression are often employed; in children and increasingly in adults, alternative donor haematopoietic stem cell transplantation is an option. We analysed the success rate of retreatment with rabbit ATG (r‐ATG)/CsA in 43 patients treated at our institution in the last 5 years; 22 were refractory (20 adults; two children) to h‐ATG/CsA‐based regimens and 21 (17 adults; four children) had relapsed after h‐ATG/CsA‐based regimens. The overall response rate was 30% in patients who were refractory to h‐ATG and 65% in patients who had relapsed following h‐ATG. The 1000‐d survival in patients who responded to r‐ATG was 90% compared with 65% in non‐responders. Six patients developed a clonal haematological disorder; two were responders, two were non‐responders and in two the evolution occurred before the response could be assessed at 3 months following r‐ATG. Thirteen patients died; three were responders, six were non‐responders and four patients died prior to 3 months when response was assessed. In our study, the response rate in refractory patients was inferior to what has been previously reported.
Continuous Positive Airway Pressure Reduces Subjective Daytime Sleepiness in Patients with Mild to Moderate Alzheimer's Disease with Sleep Disordered Breathing
Authors: Chong Mei S. , Ayalon Liat , Marler Matthew , Loredo Jose S. , Corey‐Bloom Jody , Palmer Barton W. , Liu Lianqi , Ancoli‐Israel Sonia 
Published: April 2006

OBJECTIVES: Studies have reported that 33% to 70% of patients with Alzheimer's disease (AD) have sleep‐disordered breathing (SDB). Continuous positive airway pressure (CPAP) treatment has been shown to reduce daytime sleepiness and improve health‐related quality of life in nondemented older people with SDB. The effect of therapeutic CPAP treatment on daytime sleepiness in patients with mild‐moderate AD with SDB was assessed.DESIGN: Randomized, double‐blind, placebo‐controlled trial.SETTING: Patients' home and the University of California San Diego, General Clinical Research Center, J. Christian Gillin Laboratory of Sleep and Chronobiology.PARTICIPANTS: Thirty‐nine community‐dwelling elderly patients with mild‐moderate probable AD with SDB.INTERVENTION: Patients were randomly assigned to receive 6 weeks of therapeutic CPAP or 3 weeks of sham CPAP followed by 3 weeks of therapeutic CPAP.MEASUREMENTS: Epworth Sleepiness Scale (ESS) was administered at baseline, 3 weeks, and 6 weeks. Changes in daytime sleepiness in subjects who received optimal therapeutic CPAP were compared with changes in the sham CPAP group.RESULTS: Within the therapeutic CPAP group, ESS scores were reduced from 8.89 during baseline to 6.56 after 3 weeks of treatment (P=.04) and to 5.53 after 6 weeks of treatment (P=.004). In the sham CPAP group, there was no significant difference after 3 weeks of sham CPAP but a significant decrease from 7.68 to 6.47 (P=.01) after 3 weeks of therapeutic CPAP.CONCLUSION: These data provide evidence of the effectiveness of CPAP in reducing subjective daytime sleepiness in patients with AD with SDB.
A New Parameterization of Cloud Droplet Activation Applicable to General Circulation Models
Authors: Ming Yi , Ramaswamy V. , Donner Leo J. , Phillips Vaughan T. J. 
Published: April 2006

Abstract
A new parameterization is proposed to link the droplet number concentration to the size distribution and chemical composition of aerosol and updraft velocity. Except for an empirical assumption of droplet growth, the parameterization is formulated almost entirely on first principles to allow for satisfactory performance under a variety of conditions. For a series of updraft velocity ranging from 0.03 to 10.0 m s−1, the droplet number concentrations predicted with the parameterization are in good agreement with the detailed parcel model simulations with an average error of −4 ± 26% (one standard deviation). The accuracy is comparable to or better than some existing parameterizations. The parameterization is able to account for the effects of droplet surface tension and mass accommodation coefficient on activation without adjusting the empirical parameter. These desirable attributes make the parameterization suitable for being used in the prognostic determination of the cloud droplet number concentration in general circulation models (GCMs).
Stochastic population processes in the theory of radiative transfer
Authors: Brockwell P. J. 
Published: April 2006

SummaryStarting from a characterization of radiative transfer in terms of a collision rate λ and a single-collision transition probability Ψ, we study the distribution of the generalized state ζ(t) of a radiation particle at time t conditional on a specified initial state at time t= 0. The generalized state is a vector consisting of the state ω(t) at time t and the states ω1, ω2, …, ωn of the particle immediately after the collisions it experiences in the time interval (0, t]. The variable ζ(t) takes values in a population space and can be studied conveniently with the aid of a certain generating functional G. The first-collision integral equation and the backward integro-differential equation for G are derived. Simultaneous consideration of the first-collision and last-collision equations lead to a generalized reciprocity principle for G. First-passage problems are also considered. Finally a number of illustrative examples are given.
Multivariate Poisson flows on Markov step processes
Authors: Beutler Frederick J. , Melamed Benjamin 
Published: April 2006

A Markov step process Z equipped with a possibly non-denumerable state space X can model a variety of queueing, communication and computer networks. The analysis of such networks can be facilitated if certain traffic flows consist of mutually independent Poisson processes with respective deterministic intensities λi (t). Accordingly, we define the multivariate counting process N = (N1, N2, · ·· Nc) induced by Z; a count in Ni occurs whenever Z jumps from x (χ into a (possibly empty) target set . We study N through the infinitesimal operator Ã of the augmented Markov process W = (Z, N), and the integral relationship connecting Ã with the transition operator Tt of W. It is then shown that Ni depends on a non-negative function ri defined on χ; ri (x) may be interpreted as the expected rate of increase in Ni, given that Z is in state x.A multivariate N is Poisson (i.e., composed of mutually independent Poisson streams Ni) if and only if simultaneous jumps are impossible in a certain sense, and if the conditional expectation E[ri (Z(t) | 𝒩i] = E[ri (Z(t))] for i = 1, 2, ···, c and each t ≧ 0, where 𝒩i is the σ-algebra σ{N(s), s ≦ t}. Necessary and sufficient conditions are also specified that, for each s ≦ t, the variates [Ni(t)-Ni(s)] are mutually independent Poisson distributed; this involves a weakened version of E[ri(Z(v)) | N(v) – N(u)] = E [ri(Z(v))] for i = 1, 2, ···, c and all 0 ≦ u ≦ v.It is shown that the above criteria are automatically met by the more stringent classical requirement that N(t) and Z(t) be independent for each t ≧ 0.
An operator-analytic approach to the Jackson network
Authors: Massey William A. 
Published: April 2006

Operator methods are used in this paper to systematically analyze the behavior of the Jackson network. Here, we consider rarely treated issues such as the transient behavior, and arbitrary subnetworks of the total system. By deriving the equations that govern an arbitrary subnetwork, we can see how the mean and variance for the queue length of one node as well as the covariance for two nodes vary in time.We can estimate the transient behavior by deriving a stochastic upper bound for the joint distribution of the network in terms of a judicious choice of independent M/M/1 queue-length processes. The bound we derive is one that cannot be derived by a sample-path ordering of the two processes. Moreover, we can stochastically bound from below the process for the total number of customers in the network by an M/M/1 system also. These results allow us to approximate the network by the known transient distribution of the M/M/1 queue. The bounds are tight asymptotically for large-time behavior when every node exceeds heavy-traffic conditions.
Modelling and predicting urban atmospheric pollutants in the Aosta Valley region of Italy using a site‐optimised model
Authors: Dirks Kim N. , Nanni Alessandro , Dirks Vincent I. 
Published: April 2006

AbstractAn effective simple site‐optimised urban air pollution model for predicting CO, PM10, NO and NO2 concentrations is developed for the topographically complex region of the Aosta Valley in Italy. The good results suggest that such a model could be used to ‘downscale’ mesoscale‐forecasted surface conditions to give real‐time site‐specific pollution predictions. Copyright © 2006 Royal Meteorological Society
An improved regularization for time‐staggered discretization and its link to the semi‐implicit method
Authors: Wood Nigel , Staniforth Andrew , Reich Sebastian 
Published: April 2006

AbstractA regularized time‐staggered discretization of the shallow‐water equations has recently been proposed. Here, a new form of the regularization operator is presented. This form addresses a weakness in the original formulation so that now the discretization preserves the analytic forced response. Because the reformulation takes account of the forcing terms in the equations, if the unregularized equations are in balance, in the sense that ∇.(Du/Dt) vanishes, then the regularized equations maintain this balance. Copyright © 2006 Royal Meteorological Society
Design and Synthesis of Simple Macrocycles Active Against Vancomycin‐Resistant Enterococci (VRE)
Authors: Jia Yanxing , Ma Nianchun , Liu Zuosheng , Bois‐Choussy Michèle , Gonzalez‐Zamora Eduardo , Malabarba Adriano , Brunati Cristina , Zhu Jieping 
Published: April 2006

Abstract16‐membered meta,para‐cyclophanes mimicking the vancomycin binding pocket (D–O–E ring) were designed and synthesized. The structural key features of these biaryl ether containing macrocycles are (1) the presence of β‐amino‐α‐hydroxy acid or α,β‐diamino acid as the C‐terminal component of the cyclopeptide and (2) the presence of a hydrophobic chain or lipidated aminoglucose at the appropriate position. Cycloetherification by an intramolecular nucleophilic aromatic substitution reaction (SNAr) is used as the key step for the construction of the macrocycle. The atropselectivity of this ring‐closure reaction is found to be sensitive to the peptide backbone and chemoselective cyclization (phenol versus primary amine) is achievable. Glycosylation of phenol was realized with freshly prepared 3,4,6‐tri‐O‐acetyl‐2‐N‐lauroyl‐2‐amino‐2‐deoxy‐α‐D‐glucopyranosyl bromide under phase‐transfer conditions. Minimum inhibitory concentrations for all of the derivatives are measured by using a standard microdilution assay, and potent bioactivities against both sensitive and resistant strains are found for some of these compounds (MIC (minimum inhibitory concentration)=4 μg mL−1 against VRE). From these preliminary SAR studies, it was anticipated that both the presence of a hydrophobic substituent and an appropriate structure of the macrocycle were required for this series of compounds to be active against VRE.
Fast Fourier Continuous Cyclic Voltammetry at Gold Ultramicroelectrode in Flowing Solution for Determination of Ultra Trace Amounts of Penicillin G
Authors: Norouzi Parviz , Ganjali Mohammad Reza , Alizadeh Taher , Daneshgar Parandis 
Published: April 2006

AbstractIn this work, for the first time a fast continuous cyclic voltammetry was used as a highly sensitive detection method for Penicillin G in a flow‐injection system. A special computer‐based numerical calculation method (using Fast Fourier Transformation) is introduced here for enhancing the analyte signal and noise reduction. During the measurements, the potential waveform (consists of potential steps for cleaning, stripping and potential ramp) was continuously applied on an Au disk microelectrode (with a radius 12.5 μm in radius). The stripping time was less than 200 ms. Effects of rest potential, sweep rate, and delay time on the sensitivity of the method were investigated. The limit of detection of the method was 1.0 × 10−11 M. The detection limit of the method is 660 times lower than the most sensitive reported method. The relative standard deviation of the method at 1.0×10−7 M of Penicillin G was 2.7% for 10 runs.
Silver(I)‐Selective PVC Membrane Potentiometric Sensor Based on a Recently Synthesized Calix[4]arene
Authors: Demirel Ayça , Doğan Alev , Akkuş Gülderen , Yılmaz Mustafa , Kılıç Esma 
Published: April 2006

AbstractA new PVC membrane potentiometric sensor for Ag(I) ion based on a recently synthesized calix[4]arene compound of 5,11,17,23‐tetra‐tert‐butyl‐25,27‐dihydroxy‐calix[4]arene‐thiacrown‐4 is developed. The electrode exhibits a Nernstian response for Ag(I) ions over a wide concentration range (1.0×10−2−1.0×10−6 M) with a slope of 53.8±1.6 mV per decade. It has a relatively fast response time (5–10 s) and can be used for at least 2 months without any considerable divergence in potentials. The proposed electrode shows high selectivity towards Ag+ ions over Pb2+, Cd2+, Co2+, Zn2+, Cu2+, Ni2+, Sr2+, Mg2+, Ca2+, Li+, K+, Na+, NH4+ ions and can be used in a pH range of 2–6. Only interference of Hg2+ is found. It is successfully used as an indicator electrode in potentiometric titration of a mixture of chloride, bromide and iodide ions.
An instrumented scaffold can monitor loading in the knee joint
Authors: Szivek J. A. , Bliss C. L. , Geffre C. P. , Margolis D. S. , DeYoung D. W. , Ruth J. T. , Schnepp A. B. , Tellis B. C. , Vaidyanathan R. K. 
Published: April 2006

AbstractNo technique has been consistently successful in the repair of large focal defects in cartilage, particularly in older patients. Tissue‐engineered cartilage grown on synthetic scaffolds with appropriate mechanical properties will provide an implant, which could be used to treat this problem. A means of monitoring loads and pressures acting on cartilage, at the defect site, will provide information needed to understand integration and survival of engineered tissues. It will also provide a means of evaluating rehabilitation protocols. A “sensate” scaffold with calibrated strain sensors attached to its surface, combined with a subminiature radio transmitter, was developed and utilized to measure loads and pressures during gait. In an animal study utilizing six dogs, peak loads of 120N and peak pressures of 11 MPa were measured during relaxed gait. Ingrowth into the scaffold characterized after 6 months in vivo indicated that it was well anchored and bone formation was continuing. Cartilage tissue formation was noted at the edges of the defect at the joint–scaffold interfaces. This suggested that native cartilage integration in future formulations of this scaffold configured with engineered cartilage will be a possibility. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Three‐stage contingent screening for Down syndrome
Authors: Wright Dave , Bradbury Ian , Cuckle Howard , Gardosi Jason , Tonks Ann , Standing Sue , Benn Peter 
Published: April 2006

AbstractObjectiveTo demonstrate the potential value of three‐stage sequential screening for Down syndrome.MethodsProtocols were considered in which maternal serum pregnancy associated plasma protein‐A (PAPP‐A) and free β‐human chorionic gonadotropin (hCG) measurements were taken on all women in the first trimester. Those women with very low Down syndrome risks were screened negative at that stage and nuchal translucency (NT) was measured on the remainder and the risk reassessed. Those with very low risk were then screened negative and those with very high risk were offered early diagnostic testing. Those with intermediate risks received second‐trimester maternal serum α‐fetoprotein, free β‐hCG, unconjugated estriol and inhibin‐A. Risk was then reassessed and those with high risk were offered diagnosis. Detection rates and false‐positive rates were estimated by multivariate Gaussian modelling using Monte‐Carlo simulation.ResultsThe modelling suggests that, with full adherence to a three‐stage policy, overall detection rates of nearly 90% and false‐positive rates below 2.0% can be achieved. Approximately two‐thirds of pregnancies are screened on the basis of first‐trimester biochemistry alone, five out of six women complete their screening in the first trimester, and the first‐trimester detection rate is over 60%.ConclusionThree‐stage contingent sequential screening is potentially highly effective for Down syndrome screening. The acceptability of this protocol and its performance in practice, should be tested in prospective studies. Copyright © 2006 John Wiley & Sons, Ltd.
Theoretical and experimental studies of anisotropic shrinkage in injection moldings of semicrystalline polymers
Authors: Kwon Keehae , Isayev A.I. , Kim K.H. , van Sweden C. 
Published: April 2006

AbstractA novel approach to predict anisotropic shrinkage of semicrystalline polymers in injection moldings was proposed using flow‐induced crystallization, frozen‐in molecular orientation, elastic recovery, and PVT equation of state. The anisotropic thermal expansion and compressibility affected by the frozen‐in orientation function and the elastic recovery that was not frozen during moldings were introduced to obtain the in‐plane anisotropic shrinkages. The frozen‐in orientation function was calculated from amorphous and crystalline contributions. The amorphous contribution was based on the frozen‐in and intrinsic amorphous birefringence, whereas the crystalline contribution was based on the crystalline orientation function, which was determined from the elastic recovery and intrinsic crystalline birefringence. To model the elastic recovery and frozen‐in stresses related to birefringence during molding process, a nonlinear viscoelastic constitutive equation was used with temperature‐ and crystallinity‐dependent viscosity and relaxation time. Occurrence of the flow‐induced crystallization was introduced through the elevation of melting temperature affected by entropy production during flow of the viscoelastic melt. Kinetics of the crystallization was modeled using Nakamura and Hoffman‐Lauritzen equations with the rate constant affected by the elevated melting temperature. Numerous injection molding runs on polypropylene of various molecular weights were carried out by varying the packing time, flow rate, melt temperature, and mold temperature. The anisotropic shrinkage of the moldings was measured. Comparison of the experimental and simulated results indicated a good predictive capability of the proposed approach. POLYM. ENG. SCI., 46:712–728, 2006. © 2006 Society of Plastics Engineers
Vesicular catalysis of the decarboxylation of 6‐nitrobenzisoxazole‐3‐carboxylate. The effects of sugars, long‐tailed sugars, cholesterol and alcohol additives
Authors: Jongejan Mahthild G. M. , Klijn Jaap E. , Engberts Jan. B. F. N. 
Published: April 2006

AbstractThe effects of the addition of sugars, long‐tailed n‐alkyl pyranosides, n‐alkyl glycerol ethers and n‐alcohols on the properties of di‐n‐hexadecyldimethylammonium bromide (DHAB) vesicles have been studied. Properties that were examined include the stability, morphology, phase of the tails, and catalytic rate acceleration of the unimolecular decarboxylation of the 6‐nitrobenzisoxazole‐3‐carboxylate anion (6‐NBIC). The kinetic data were analyzed on the basis of the pseudophase model and show a rate acceleration of a factor of about 1000 relative to the reaction in water. Upon addition of most additives an inhibiting effect on the decarboxylation reaction of 6‐NBIC is observed relative to the reaction in vesicles without any additive. The largest inhibition was observed in the case of cholesterol. Contrastingly, n‐dodecyl‐β‐maltoside (in the spherical vesicle region) and trehalose accelerate the reaction. The activation parameters show that the most significant contribution to the Gibbs energy of activation is the enthalpic factor, with a partly compensating entropic contribution. Copyright © 2006 John Wiley & Sons, Ltd.