bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ion-assisted pulsed laser deposition of cubic boron nitride films
Authors: Friedmann T. A. , Mirkarimi P. B. , Medlin D. L. , McCarty K. F. , Klaus E. J. , Boehme D. R. , Johnsen H. A. , Mills M. J. , Ottesen D. K. , Barbour J. C. 
Published: July 2002

Ion-assisted pulsed laser deposition has been used to produce films containing ≳85% sp3-bonded cubic boron nitride (c-BN). By ablating from a target of hexagonal boron nitride (h-BN), BN films have been deposited on heated (50–800 °C) Si(100) surfaces. The growing films are irradiated with ions from a broad beam ion source operated with Ar and N2 source gasses. Successful c-BN synthesis has been confirmed by Fourier transform infrared (FTIR) spectroscopy, high-resolution transmission electron microscopy (TEM), selected-area electron diffraction, electron energy-loss spectroscopy, and x-ray diffraction. The films are polycrystalline and show grain sizes up to 300 Å. In addition, Rutherford backscattering, elastic recoil detection, and Auger electron spectroscopies have been used to further characterize the samples. The effects of varying ion current density, substrate growth temperature, growth time, and ion energy have been investigated. It is found that stoichiometric films with a high c-BN percentage can be grown between 150 and 500 °C. Below ∼150 °C, the c-BN percentage drops dramatically, and the deposited film is completely resputtered at the current densities and ablation deposition rates used. As the deposition temperature rises above ∼500 °C the c-BN percentage also drops, but less dramatically than at low temperatures.
In addition, the IR-active c-BN mode narrows considerably as the deposition temperature increases, suggesting that the c-BN material has fewer defects or larger grain size. It is found that films with a high c-BN percentage are deposited only in a narrow window of ion/atom arrival values that are near unity at beam energies between 800 and 1200 eV. Below this window the deposited films have a low c-BN percentage, and above this window the deposited film is completely resputtered. Using FTIR analysis, it is found that the c-BN percentage in these samples is dependent upon growth time. The initial deposit is essentially all sp2-bonded material and sp3-bonded material forms above this layer. Consistently, cross-section TEM samples reveal this layer to consist of an amorphous BN layer (∼30 Å thick) directly on the Si substrate followed by highly oriented turbostratic BN (∼300 Å thick) and finally the c-BN layer. The h-BN/t-BN interfacial layer is oriented with the 002 basal planes perpendicular to the plane of the substrate. Importantly, the position of the c-BN IR phonon changes with growth time. Initially this mode appears near 1130 cm−1 and decreases with growth time to a constant value of 1085 cm−1. Since in bulk c-BN the IR mode appears at 1065 cm−1, a large compressive stress induced by the ion bombardment is suggested. Possible mechanisms are commented on for the conversion process to c-BN based upon the results.
Two-fluid Chapman–Enskog theory for binary gas mixtures
Authors: Fernandez de la Mora J. , Fernandez-Feria R. 
Published: July 2002

As a result of the increasing inefficiency in the transfer of energy in collisions between species with a decreasing ratio of molecular masses, the Knudsen number range of validity of the Chapman–Enskog (CE) theory for binary gas mixtures decreases linearly with the molecular mass ratio. To remedy the situation, a two-fluid CE theory uniformly valid in the molecular mass ratio is constructed here. The analysis extends previous two-fluid theories to allow for arbitrary potentials of intermolecular interaction and arbitrary mass ratios. The treatment differs from the CE formulation in that the mean velocities and temperatures of the two gases are not required to be identical to lowest order. To first order, the streaming terms of the Boltzmann equation are thus computed in terms of the derivatives of the two-fluid hydrodynamic quantities, rather than the mean mixture properties as in the CE theory. As a result, associated with the nonconservation of momentum and energy for each species alone, two new ‘‘driving forces’’ appear in the first-order integral equations. The amount of momentum and energy transferred per unit time between the species appear in the theory as free constants, which allow satisfying the constraint that all hydrodynamic information be contained within the lowest-order two-fluid Maxwellians. Simultaneously, this constraint fixes the rate of momentum and energy interchange in terms of the two-fluid hydrodynamic quantities and their gradients. The driving force d12 of the CE theory is directly related to the rate of interspecies momentum transfer, and the corresponding CE functions D1 and D2 appear here unmodified.
But the physical interpretation of d12 is very different in the two pictures. On the CE side there is only one momentum equation, while d12 provides constitutive information fixing the diffusion flux (velocity differences) in the mass conservation equation. Here, the similar constitutive information associated to d12 is used to couple two different momentum equations. Although the CE theory captures some of the two-velocity aspects of the problem, no CE analog exists with the functions E1 and E2 associated here with temperature differences, which now require solving new integral equations. Finally, the presence of two velocities and two temperatures leads to four coefficients of viscosity and of thermal conductivity for the two stress tensors and heat flux vectors. Also, two thermal diffusion factors enter now into the expression for d12. Although all these new coefficients arise as portions of the overall CE transport coefficients, their independent optimal determination requires new developments. The corresponding variational formulation is presented here and used to first order to obtain explicit expressions for all two-fluid transport coefficients by means of Sonine polynomials as trial functions.
My company or my career: managerial achievement and loyalty
Authors: Wajcman Judy , Martin Bill 
Published: July 2002

ABSTRACTThis article examines the objective and subjective aspects of managerial careers in six large firms that have experienced organizational restructuring. We begin by assessing the dominant models of change in career structures, particularly those which emphasize the ‘portfolio’ route to career success. Although elements of the bureaucratic career remain, we find some evidence of the shift predicted by these models amongst the younger generation of managers. However, it is striking that not all young managers are able to take advantage of the opportunities offered by the new career model. Indeed, cultural capital has an increasing impact on career achievement. Younger managers are responding by reorienting away from organizational loyalty towards a concern with individual career projects.
An Ordinal Scale for Transitive Reasoning by Means of a Deductive Strategy
Authors: Verweij Anton C. , Sijtsma Klaas , Koops Willem 
Published: July 2002

Transitivity tasks with either equality or inequality relations between three, four, or five objects were presented by means of a successive and a simultaneous presentation procedure to 124 third-grade primary schoolchildren. Equality tasks were easier than inequality tasks. Inequality tasks were more difficult when presented successively than simultaneously. Difficulty of equality tasks was not affected by presentation procedure. These findings were interpreted in terms of the Fuzzy Trace Theory. Successively presented inequality tasks induced more deductive reasoning strategies, and simultaneously presented tasks induced both positional and reductional strategies. As perceptual differences between objects increased, more visual strategies were used. These conclusions were used to construct a series of nine tasks geared at inducing transitive reasoning by means of a deductive strategy. Mokken scale analysis was used to construct an ordinal scale for transitive reasoning. Data were collected from 417 second- through fourth-grade primary school children. The scale score correlated highly with arithmetic skills and insight into the quantity concept. Possibilities for future transitivity research, supported by advanced psychometric methods, are discussed.
Pedagogy, information and communications technology and teachers' professional knowledge
Authors: Leach Jenny , Moon Bob 
Published: July 2002

ABSTRACTIn this article UK governmental policy imperatives to apply new forms of information and communications technology (ICT) to school improvement are explored, with particular reference to the National Curriculum for England and Wales. The analysis juxtaposes the piecemeal, random way in which ICT is used in National Curriculum programmes of study and schemes of work with the government rhetoric that requires coherent planning and integration of ICT within all aspects of teaching learning. The article argues that this contradiction within the policy process could be overcome if a stronger conceptualization of teachers' professional knowledge was embraced. An example of such a conceptualization is presented and this is exemplified by accounts of teachers' development of ICT within their pedagogic practice.
Implication of extracellular zinc exclusion by recombinant human calprotectin (MRP8 and MRP14) from target cells in its apoptosis‐inducing activity
Authors: Yui Satoru , Nakatani Yuichi , Hunter Michael J. , Chazin Walter J. , Yamazaki Masatoshi 
Published: July 2002

Background: Calprotectin is a calcium‐binding and zinc‐binding protein complex that is abundant in the cytosol of neutrophils. This factor is composed of 8 and 14 kDa subunits, which have also been termed migration inhibitory factor‐related proteins MRP8 and MRP14. We previously reported that rat calprotectin purified from inflammatory neutrophils induces apoptosis of various tumor cells or normal fibroblasts in a zinc‐reversible manner.Aim: The present study was undertaken to elucidate which subunit is responsible for the apoptosis‐inducing activity, and to explore the mechanism of zinc‐reversible apoptosis induction.Methods: The apoptosis‐inducing activity of recombinant human MRP8 (rhMRP8) and recombinant human MRP14 (rhMRP14) was examined against EL‐4 lymphoma cells in vitro. To determine whether zinc deprivation by calprotectin was essential for the cytotoxicity, the activity of calprotectin was tested under conditions where physical contact between the factor and the cells was precluded by a low molecular weight cut‐off dialysis membrane.Results: The cytotoxicity of rhMRP14 against EL‐4 cells was first detected at 10 μM in a standard medium, whereas rhMRP8 caused only marginal cytotoxicity at 40 μM. A mixture of both proteins showed higher specific activity (onset of cytotoxicity at 5 μM). When the cells were cultured in divalent cation‐depleted medium, each dose‐response curve was shifted to about a four‐fold lower concentration range. Calprotectin was found to induce cell death even when the complex and the target cells were separated by dialysis membrane. A membrane‐impermeable zinc chelator, diethylenetriamine pentaacetic acid (DTPA), also induced target cell apoptosis in a similar time‐course as calprotectin. Moreover, the activities of calprotectin and DTPA were completely inhibited by the presence of zinc ions.Conclusion: These data indicate that calprotectin has higher specific activity to induce apoptosis than the individual subunits, and that the mechanism is exclusion of zinc from target cells.
Neuropharmacology and therapeutic potential of cannabinoids
Authors: Pertwee Roger G. 
Published: July 2002

AbstractMammalian tissues contain at least two types of cannabinoid receptor, CB 1, found mainly on neurones and CB 2, found mainly in immune cells. Endogenous ligands for these receptors have also been identified. These endocannabinoids and their receptors constitute the endogenous cannabinoid system. Two cannabinoid receptor agonists, Δ9‐tetrahydrocannabinol and nabilone, are used clinically as anti‐emetics or to boost appetite. Additional therapeutic uses of cannabinoids may include the suppression of some multiple sclerosis and spinal injury symptoms, the management of pain, bronchial asthma and glaucoma, and the prevention of neurotoxicity. There are also potential clinical applications for CB 1 receptor antagonists, in the management of acute schizophrenia and cognitive/memory dysfunctions and as appetite suppressants. Future research is likely to be directed at characterizing the endogenous cannabinoid system more completely, at obtaining more conclusive clinical data about cannabinoids with regard to both beneficial and adverse effects, at developing improved cannabinoid formulations and modes of administration for use in the clinic and at devising clinical strategies for separating out the sought‐after effects of CB 1 receptor agonists from their psychotropic and other unwanted effects.
Responses of Neurons in Macaque Area V4 During Memory-guided Visual Search
Authors: Chelazzi Leonardo , Miller Earl K. , Duncan John , Desimone Robert 
Published: July 2002

Abstract
In a typical scene with many different objects, attentional mechanisms are needed to select relevant objects for visual processing and control over behavior. To test the role of area V4 in the selection of objects based on non-spatial features, we recorded from V4 neurons in the monkey, using a visual search paradigm. A cue stimulus was presented at the center of gaze, followed by a blank delay period. After the delay, a two-stimulus array was presented extrafoveally, and the monkey was rewarded for detecting the target stimulus matching the cue. The array was composed of one ‘good’ stimulus (effective in driving the cell when presented alone) and one ‘poor’ stimulus (ineffective in driving the cell when presented alone). When the choice array was presented in the receptive field (RF) of the neuron, many cells showed suppressive interactions between the stimuli as well as strong attention effects. Within 150–200 ms of array onset, responses to the array were determined by the target stimulus. If the target was the good stimulus, the response to the array became equal to the response to the good stimulus presented alone. If the target was the poor stimulus, the response approached the response to that stimulus presented alone. Thus the influence of the nontarget stimulus was filtered out. These effects were reduced or eliminated when the poor stimulus was located outside the RF and, therefore, no longer competing for the cell's response. Overall, the results support a ‘biased competition’ model of attention, according to which objects in the visual field compete for representation in the cortex, and this competition is biased in favor of the behaviorally relevant object.
Differential expression of thymosin β‐10 by early passage and senescent vascular endothelium is modulated by VPF/VEGF: evidence for senescent endothelial cells in vivo at sites of atherosclerosis
Authors: VASILE ELIZA , TOMITA YASUHIKO , BROWN LAWRENCE F. , KOCHER OLIVIER , DVORAK HAROLD F. 
Published: July 2002

ABSTRACTVPF/VEGF acts selectively on the vascular endothelium to enhance permeability, induce cell migration and division, and delay replicative senescence. To understand the changes in gene expression during endothelial senescence, we investigated genes that were differentially expressed in early vs. late passage (senescent) human dermal endothelial cells (HDMEC) using cDNA array hybridization. Early passage HDMEC cultured with or without VPF/VEGF overexpressed 9 and underexpressed 6 genes in comparison with their senescent counterparts. Thymosin β‐10 expression was modulated by VPF/VEGF and was strikingly down‐regulated in senescent EC. The β‐thymosins are actin G‐sequestering peptides that regulate actin dynamics and are overexpressed in neoplastic transformation. We have also identified senescent EC in the human aorta at sites overlying atherosclerotic plaques. These EC expressed senescence‐associated neutral β‐galactosidase and, in contrast to adventitial microvessel endothelium, exhibited weak staining for thymosin β‐10. ISH performed on human malignant tumors revealed strong thymosin β‐10 expression in tumor blood vessels. This is the first report that Tβ‐10 expression is significantly reduced in senescent EC, that VPF/VEGF modulates thymosin β‐10 expression, and that EC can become senescent in vivo. The reduced expression of thymosin β‐10 may contribute to the senescent phenotype by reducing EC plasticity and thus impairing their response to migratory stimuli.—Vasile, E., Tomita, Y., Brown, L. F., Kocher, O., Dvorak, H. F. Differential expression of thymosin Β‐10 by early passage and senescent vascular endothelium is modulated by VPF/VEGF: evidence for senescent endothelial cells in vivo at sites of atherosclerosis. FASEB J. 15, 458‐466 (2001)
Coordinated expression in chronically unconscious persons
Authors:   The American Association for Research into Nervous and Mental Diseases, Plum F. , Schiff N. , Ribary U. , Llinás R. 
Published: July 2002

The clinically described ‘persistent vegetative state’ (PVS), consists of wakefulness unaccompanied by any evidence of the subject's awareness of self or environment. Past studies from our own and other laboratories have used positron emission tomography (PET) to study brain metabolism in approximately 20 such patients during wakeful periods. All those efforts identified global cerebral glucose metabolism at or below levels encountered during deep barbiturate anaesthesia. Nevertheless, the clinical literature includes rare reports of relatively isolated cognitive functions expressed by PVS patients late in their course. The observation raises the question of whether such activity reflects awareness or unconscious automatic behaviour. We employed magnetometry (MEG), PET scanning, MR imaging and 24–hour EEG recordings to evaluate three patients clinically vegetative between six months and 20 years after onset.
Neither meticulous clinical examinations nor 24–hour EEG and video monitoring provided any hint of cognitive interaction in any subject. Nevertheless, patient 1 uttered single words once every 48 hours or more; patient 2 frequently expressed coordinated, non–purposeful, non–dystonic movements in arms and/or legs; and, patient 3 expressed strong emotional negativity without motor responses to noxious stimuli with occasional quieting in response to prosodic stimuli.
All patients had whole–brain averaged global metabolism levels below 50% of normal. Patient 1, however, demonstrated preserved islands of increased metabolism in the posterior frontal and posterior temporal lobes, as well as MEG activations of Heschl's gyrus all located in the left hemisphere. In patient 2, selected increased metabolism was confined to the frontal poles and related subcortical structures. MRI in patient 3 demonstrated severe, bilateral post–traumatic cerebral atrophy. PET metabolism was diffusely reduced to 40% of normal but MEG evoked potentials indicated early and late sensory processing with abnormal later evoked components.
The correlation of fragmentary behaviour with preserved metabolic and physiologic activity in cortical and subcortical regions known to support specific modular functions is novel. The finding demonstrates the capacity of severely damaged brains to partially express surviving modular functions without evidence of integrative processes that would be necessary to produce consciousness. These data represent a baseline against which less severely damaged brains may be assessed and ultimately tested the recovery of conscious expression.
We conclude that the mere expression of isolated neuropsychologic activity by isolated modules is insufficient to generate consciousness in overwhelmingly damaged brains.
Room‐Temperature Colossal Elastocaloric Effects in Three‐Dimensional Graphene Architectures: An Atomistic Study
Authors: Zhao Zhiqiang , Guo Wanlin , Zhang Zhuhua 
Published: June 2022

AbstractSolid‐state cooling exploits the thermal response of caloric materials when subjected to external physical fields and represents a promising alternative to conventional refrigeration technologies. However, existing caloric materials are often limited by relatively small caloric response and hysteresis issues rooted in first‐order structural transitions. Here, colossal and reversible elastocaloric effects near room temperature in superelastic graphene architectures are predicted by thermodynamic analysis and atomistic calculations. The estimated adiabatic temperature change can reach a value of 155 K under a compressive stress of 0.7 GPa in a wide temperature range of around 300 K, yielding outstanding elastocaloric strength and efficiency. More unique is that both cooling and warming can be realized in the materials by applying tensile and compressive strains to host conventional and inverse elastocaloric effects, respectively, with almost no fatigue behavior and hysteresis effect. Such unprecedented elastocaloric performance results from a strain‐induced large change in configurational entropy in the graphene architectures. These effects are potentially extendable to other superelastic nanomaterials and hence suggest new material settings for developing high‐performance solid‐state refrigerants.
Stretchable Non‐Enzymatic Fuel Cell‐Based Sensor Patch Integrated with Thread‐Embedded Microfluidics for Self‐Powered Wearable Glucose Monitoring
Authors: Bae Chan Wool , Chinnamani Mottour Vinayagam , Lee Eung Hyuk , Lee Nae‐Eung 
Published: June 2022

AbstractWearable sensor patches for continuous or intermittent monitoring of biomolecules from body fluids are highly desired as a stretchable integrated platform conformable and attachable to the human body. However, realizing such integrated sensor patches is very challenging because of the difficulty of achieving full stretchability, controlling transport of the body fluid, and minimizing power consumption. In this study, a stretchable and self‐powered microfluidic‐integrated sensor patch comprising a stretchable non‐enzymatic fuel cell‐based sweat glucose sensor and a stretchable cotton thread‐embedded microfluidic device is demonstrated. To endow the fuel cell‐based glucose sensor with stretchability, the anode and cathode electrodes with catalytic nanoporous Au (NPG) and NPG coated with Pt nanoparticles (PtNPs@NPG), respectively, are formed on an omnidirectionally stretchable substrate with a three‐dimensional micropattern that can effectively absorb the stress generated during deformation. In addition, a stretchable microfluidic device made by embedding cotton thread into a polydimethylsiloxane (PDMS) channel for powerless constant absorption and sweat flow is integrated into the fuel cell structure. The fully stretchable microfluidic‐integrated self‐powered sensor patch demonstrates excellent continuous monitoring of the sweat glucose concentration.