bluuebunny/crossref_metadata_2025 huggingface dataset:
A General Chemical Route for the Synthesis of Capped Nanocrystalline Materials
Authors: Tzitzios V. , Georgakilas V. , Zafiropoulou I. , Boukos N. , Basina G. , Niarchos D. , Petridis D.
Published: June 2008

Noble metals, magnetic and semiconducting nanocrystalline materials have been synthesized via the thermolytic decomposition of inorganic metal salts, at high temperature, in commercial oleyl amine. The oleyl amine acts as high boiling point coordinating solvent, capping agent and, when
required, as reducing agent. The crystal structure and morphology of the nanostructured materials have been studied with powder X-ray analysis (XRD) and transmission electron microscopy (TEM). The particles are well dispersed in non polar solvents such as hexane, toluene and chloroform and
have uniform morphology.
High Molecular Weight Polyethylene Nanospheres: Synthesis Physical and Mechanical Properties
Authors: Paik Pradip , Kar Kamal K.
Published: June 2008

The high molecular weight (MW) polyethylene (PE) particles of particle size varied from macro to micron to nanometer were synthesized by Grignard reagent. The microscopy analysis (scanning electron microscope, SEM; transmission electron microscope, TEM; and atomic force microscope,
AFM) shows the spherical shape of PE particles. The effects of particle size, varies from macro to nanometer scale on crystal structure, crystallinity (χc), glass transition temperature (Tg), melting temperature (Tm), surface roughness
and mechanical properties were studied. Differential scanning calorimetry (DSC) experiments show that the nanoparticles of PE are highly crystalline (χc ≈ 72%). The crystal length of PE nanoparticles is found to be approximately 14 Å. Although the Gibbs-Thomson
equation is explained the depression of melting temperature (ΔTm) by 5 °C, the impervious results of Tg are still not fully understood. The low roughness value (2 Å) proves the presence of "atomic-scale-chain" folding at the surface of PE
nanoparticles. A novel protocol is developed, and the elastic modulus of individual nanospherical PE particles is computed from 'force-distance' mapping curves of AFM. Hemispherical tungsten (W) tip was fabricated from focused ion beam and used as an indenter to measure the mechanical properties.
It is found that the nano sized PE particles have higher elastic modulus (E = 1.2–1.4 GPa) compared to the bulk or macro sized PE (E = 0.6–0.7 GPa). The results corroborate the robustness of our experiments, since, the analogous results for macro sized particles match
well with the literature.
Effects of Feed Gas Composition and Catalyst Thickness on Carbon Nanotube and Nanofiber Synthesis by Plasma Enhanced Chemical Vapor Deposition
Authors: Garg R. K. , Kim S. S. , Hash D. B. , Gore J. P. , Fisher T. S.
Published: June 2008

Many engineering applications require carbon nanotubes with specific characteristics such as wall structure, chirality and alignment. However, precise control of nanotube properties grown to application specifications remains a significant challenge. Plasma-enhanced chemical vapor deposition
(PECVD) offers a variety of advantages in the synthesis of carbon nanotubes in that several important synthesis parameters can be controlled independently. This paper reports an experimental study of the effects of reacting gas composition (percentage methane in hydrogen) and catalyst film
thickness on carbon nanotube (CNT) growth and a computational study of gas-phase composition for the inlet conditions of experimentally observed carbon nanotube growth using different chemical reaction mechanisms. The simulations seek to explain the observed effects of reacting gas composition
and to identify the precursors for CNT formation. The experimental results indicate that gas-phase composition significantly affects the synthesized material, which is shown to be randomly aligned nanotube and nanofiber mats for relatively methane-rich inlet gas mixtures and non-tubular carbon
for methane-lean incoming mixtures. The simulation results suggest that inlet methane-hydrogen mixture coverts to an acetylene-methane-hydrogen mixture with minor amounts of ethylene, hydrogen atom, and methyl radical. Acetylene appears to be the indicator species for solid carbon formation.
The simulations also show that inlet methane-hydrogen mixture does not produce enough gas-phase precursors needed to form quality CNTs below 5% CH4 concentrations in the inlet stream.
Silver Nanoparticles/Montmorillonite Composites Prepared Using Nitrating Reagent at Water and Glycerol
Authors: Valášková Marta , Simha Martynková Gražyna , Lešková Jana , Čapková Pavla , Klemm Volker , Rafaja David
Published: June 2008

Three procedures (P) were applied to prepare silver nanoparticles on natural Ca-montmorillonite (MT). The intercalation of the montmorillonite with silver nitrate in aqueous solution (P1), the intercalation of the montmorillonite with silver nitrate in glycerol (P2) and the successive
combination of both P1 and P2methods resulted to P3 method. X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and Fourier Transform Infrared (FTIR) spectroscopy and the molecular modeling were employed to characterize silver nanoparticles and montmorillonite
nanocomposite. The P1 produced MT-1 composite with 2.3 wt% Ag and the partially collapsed layered structure. Nanoparticles of silver larger than 20 nm with a lot of planar defects were randomly distributed on the MT-1 surface; nanoparticles smaller than 20 nm were oriented to the montmorillonite
substrate. The MT-2 composite from P2 contained only 1 wt% of Ag. The molecular simulation model of MT-2 showed the interlayer space with the exchangeable cations and metallic silver atoms arrangement within the glycerol bilayer. The P3 produced composite MT-3 that contained 2.4 wt% Ag. The
nanoparticles > 20 nm size had a well-defined geometry, very small nanoparticles were amorphous. The modeled structure showed the exchangeable cations, Ag+ and Ag0 located close to the silicate layers and monolayer of glycerol molecules in the interlayer space.
Electrochemical Sensing of Sulphur Dioxide: A Comparison Using Dodecanethiol and Citrate Capped Gold Nanoclusters
Authors: Sathe Bhaskar R. , Risbud Mandar S. , Mulla Imtiaz S. , Pillai Vijayamohanan K.
Published: June 2008

A comparison of cyclic voltammograms of dodecanethiol (DDT) capped Au nanoclusters (5.0 ± 0.5 nm) and trisodium citrate (Cit) capped Au nanoclusters (∼10–15 nm) modified glassy carbon electrode shows a dramatic variation in the current when exposed to a small amount
of sulphur dioxide. This is explained using the electrocatalytic properties of Au nanoclusters towards the oxidation of SO2, thus facilitating the fabrication of electrochemical sensors for the detection of SO2. The intrinsic redox changes observed for gold nanocluster-modified
glassy carbon electrodes disappear on passing SO2, despite a dramatic current increase, which indeed scales up with the amount of dissolved SO2. Interestingly, a complete rejuvenation of the redox behavior of gold is also observed on subsequent removal of SO2
from the solution by passing pure nitrogen for 15 minutes. Further, these nanoclusters when characterized with X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) after SO2 passage reveal a variety of SO2 adsorption modes on gold
surface. XP spectra also showa shift of 1.03 eV towards higher binding energy indicating a strong adsorption of SO2 gas, while FTIR gives conclusive evidence for the interaction of SO2 with gold nanoparticles.
Nanoparticles-Based Phenol-Formaldehyde Hybrid Resins
Authors: Hernández-Padrón Genoveva , García-Garduño Margarita , Canseco Miguel A. , Castaño Víctor M.
Published: June 2008

The synthesis, characterization and corrosion properties of a novel material, produced by the reaction of silica nanoparticles with a functionalized Phenol-Formaldehyde Resin (PFR), are presented. Carboxylic groups were attached in situ to the PFR skeleton to produce a functionalized
resin (PFR-SA), which is then reacted with sol–gel-prepared silica nanoparticles, yielding a novel hybrid (organic/inorganic) material (PFR-SA-nanoSiO2). This hybrid material was characterized by FT-IR, FT-Raman, TGA, DSC, SEM and corrosion tests, whose results showed significant
improvement of the thermal properties in comparison with the PFR coating. In addition, the new material was efficient and durable against corrosion of metals, with the anticorrosive performance of PFR-SA and PFR-SA/nanoSiO2 coating films being superior to those of the original PFR
coating.
High Molecular Weight Polyethylene Nanospheres: Synthesis, Physical and Mechanical Properties—Second Harmonic Generation
Authors: Hsu C. J. , Chang L. W. , Miao S. Y. , Lue J. T.
Published: June 2008

The weak second harmonic light generating from carbon nanotubes are detected. The signal intensity closely related to the density of π-bonds attributed to the defects in the rolled graphene sheets, which is stimulated to have anharmonic oscillation as strongly affected by
the environment. The intensities of SHG are diminished in order of well-aligned multi-wall carbon nanotubes (MWCNTs), randomly-aligned MWCNTs, and then to single-wall CNTs.
Nanofibrous Glass Tailored with Apatite-Fibronectin Interface for Bone Cell Stimulation
Authors: Kim Hae-Won , Lee Hae-Hyoung , Knowles Jonathan C.
Published: June 2008

Exploring a material with smart and biomimetic interface has great potential in the biomaterials and tissue engineering field. This paper reports a novel nanofibrous bone matrix that was developed to retain a cell-stimulating and bone-mimetic biointerface. The bone mineral, apatite,
and the cell adhesive protein, fibronectin (FN), were hybridized on the interface of a bioactive glass nano-fibrous mesh, through the dissolution-and-reprecipitation process. The hybridized nanofibrous mesh showed significant improvement in the initial responses of the bone-derived cells.
It is believed that this biomimetic and cell-stimulating nanofibrous mesh can be used as a potential bone regeneration matrix.
Assessing the Density Functional Theory in the Hydrogen Storage Problem
Authors: Mpourmpakis Giannis , Froudakis George E.
Published: June 2008

A variety of high and low level ab-initio calculations have been performed to calculate hydrogen's physisorption binding energy on carbon nanotube's walls. This study focuses on the performance of several functionals on treating the H2-carbon nanotube interaction within
the Density Functional Theory. Our results show that the behavior of the exchange functional in the low density region plays an important role in describing this weak van der Waals type of interaction. By comparing the binding energy values obtained on each theoretical level and interpreting
the results in terms of %wt percentages of hydrogen storage using the Langmuir isotherms, we proposed possible ways to treat computationally the hydrogen storage problem within the DFT.
Photophysical and Photobiological Studies of a Silicon Tribenzonaphthoporphyrazinato Incorporated into Liposomes for Photodynamic Therapy Use
Authors: Simioni Andreza R. , Pelisson Marcelo M. M. , Beltrame Milton , Tedesco Antonio C.
Published: June 2008

Nanostructured drug delivery systems (NDDS), such as liposomes, represent a growing area in biomedical research. These microheterogeneous media can be used in many biological systems to provide appropriate drug levels with a specific biodistribution. The photophysical properties of
a silicon derivative of tribenzonaphthoporphyrazinato (Si-tri-PcNc) incorporated into liposome were studied by steady-state techniques, time-resolved fluorescence and laser flash photolysis. All the spectroscopy measurements performed allowed us to conclude that Si-tri-PcNc in
liposome is a promising NDDS for PDT. The in vitro experiments with liposomal NDDS showed that the system is not cytotoxic in darkness, but exhibits a substantial phototoxicity at 1 μM of photosensitizer concentration and 10.0 J/cm2 of light. These conditions are
sufficient to kill about 80% of the cells.
ZnO Nanonails: Synthesis and Their Application as Glucose Biosensor
Authors: Umar Ahmad , Rahman M. M. , Kim S. H. , Hahn Y. B.
Published: June 2008

Well-crystallized zinc oxide nanonails were grown in a high density by thermal evaporation process and were used as supporting matrixes for glucose oxidase (GOx) immobilization to construct efficient glucose biosensor. The GOx attached to the surfaces of ZnO nanonails had more spatial
freedom in its orientation, which facilitated the direct electron transfer between the active sites of immobilized GOx and electrode surface. The fabricated biosensor showed a high sensitivity of 24.613 μA cm–2 mM–1 with a response time less than
10 s. Moreover, it shows a linear range from 0.1 to 7.1 mM with a correlation coefficient of R = 0.9937 and detection limit of 5 μM.
Synthesis and Structural Characterization of Mo-Ni-W Oxide Nanostructures
Authors: Paraguay-Delgado F. , Huirache-Acuña R. , Jose-Yacaman M. , Alonso-Nuñez G.
Published: June 2008

In this work, we report the synthesis and characterization of Mo-Ni-W oxides. The precursor was prepared from an aqueous solution of ammonium heptamolibdate, ammonium metatungstate, and nickel nitrate with an atomic ratio of 1:1:1 (Mo:W:Ni). The solution was then transferred to a Teflon-lined
stainless steel autoclave and heated to 200 °C and left at this temperature for 48 h. The resulting material was then washed and dried. The morphology and elemental composition were studied by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy,
and X-ray diffraction. The porosity was studied by the Brunauer, Emmett, and Teller method. The materials synthesized at 200 °C remained amorphous and had a specific surface area of 114 m2/g with pore size of 34 Å. The average length was 1 μm and the average
diameter was 60 nm. The crystalline phase of synthesized material corresponded to W0.4Mo0.6O3 and WO3. After annealing at 550 °C for two hours, the material was polycrystalline with a segregated structure of MoO3, WO3; NiMoO4
was observed. The sublimation of the molybdenum oxide was evident when annealed at 900 °C for two hours and finally two crystalline phases of material remained; roundish WO3 and elongated particles of NiWO4.
STM Study of Au Adsorption on Si(111)-7 × 7 Surface: Voltage and Temperature Dependence
Authors: Zhou Yinghui , Wu Qi-Hui , Kang Junyong
Published: June 2008

We presented the scanning tunneling microscopy (STM) results on the study of Au adsorption at Si(111)-7 × 7 reconstructed surface. The voltage-dependent STM measurements indicated that there are at least three kinds of Au clusters and two types of single Au atoms adsorption on
Si(111)-7 × 7 surface with Au coverage of about 0.2 monolayer. After the Au adsorbed Si surface was annealed at about 250 °C, the adsorbed Au clusters would diffuse into the Si substrate, and consequently create surface defects on the Si substrate. Sequentially annealed the sample
at about 500 °C, the diffused Au would emerge out again and form larger 3-dimension Au clusters at the Si surface.
Thickness Dependent Structural, Electronic, and Optical Properties of Ge Nanostructures
Authors: Tripathi S. , Brajpuriya R. , Sharma A. , Soni A. , Okram G. S. , Chaudhari S. M. , Shripathi T.
Published: June 2008

In the present paper, we have investigated structural, optical as well as electronic properties of electron beam evaporated Ge thin films having layer thicknesses ranging from ultra-thin (5 nm) to thick (200 nm). The Raman spectra show that all peaks are shifted towards lower wave number
as compared to their bulk counterparts and are considered as a signature of nanostructure formation and quantum confinement effect. The Raman line exhibits transformation from nanocrystalline to microcrystalline phase with a reduction in blue shift of peak position with increase in Ge film
thickness (>5 nm). Similarly, the optical absorption spectra corresponding to these films also show reduction in blue shift effect, although Ge 5 nm film shows the absorption behaviour quite different from higher thickness films. The corresponding band gap values obtained from absorption
measurements are much larger than bulk Ge and are mainly attributed to the effect of quantum confinement as expected for small size particles calculated from GIXRD patterns. AFM data in each case are correlated and discussed with structural as well as optical results to support the effect
of growth morphology on the above-mentioned observations. The results are further supported by photoelectron spectroscopy (PES), photoluminescence (PL) and resistivity measurements and are interpreted in terms of crystallinity and quantum confinement effect.
Nanocrystalline Diamond Films Grown in Nitrogen Rich Atmosphere: Structural and Field Emission Properties
Authors: Orlanducci S. , Fiori A. , Sessa V. , Tamburri E. , Toschi F. , Terranova M. L.
Published: June 2008

The field emission behaviour of a series of nanocrystalline N-doped diamond films has been investigated and interpreted on the basis of the structural and compositional characteristics of the layers. The diamond films, formed by crystallites with grain size in the range 20–100
nm were produced from CH4/H2 mixtures using a HF-CVD apparatus. Nitrogen was added to the gaseous reactants in form of both N2 and of Urea. Micro-Raman spectroscopy and cathodoluminescence have been used to define the structure of the deposits on a nanometric
scale. The field emission measurements have been carried out under a pressure of 10–6 mbar using a sphere-to-plane anode-cathode configuration. The characteristics of the emission from the various nanodiamond samples and from different regions of the same sample are discussed
in terms of field threshold, current density, current stability.
Optical Response of Ag-Au Bimetallic Nanoparticles to Electron Storage in Aqueous Medium
Authors: Tunc Ilknur , Osman Guvenc Haci , Sezen Hikmet , Suzer Sefik , Correa-Duarte Miguel A. , Liz-Marzán Luis M.
Published: June 2008

Composition and structure dependence of the shift in the position of the surface plasmon resonance band upon introduction of NaBH4 to aqueous solutions of gold and silver nanoparticles are presented. Silver and gold nanoalloys in different compositions were prepared by co-reduction
of the corresponding salt mixtures using sodium citrate as the reducing agent. After addition of NaBH4 to the resultant nanoalloys, the maximum of their surface plasmon resonance band, ranging between that of pure silver (ca. 400 nm) and of pure gold (ca. 530 nm), is blue-shifted
as a result of electron storage on the particles. The extent of this blue shift increases non-linearly with the mole fraction of silver in the nanoparticle, parallel to the trends reported previously for both the frequency and the extinction coefficient of the plasmon band shifts. Gold(core)@silver(shell)
nanoparticles were prepared by sequential reduction of gold and silver, where addition of NaBH4 results in relatively large spectral shift in the plasmon resonance band when compared with the nanoalloys having a similar overall composition. The origin of the large plasmon band shift
in the core–shell is related with a higher silver surface concentration on these particles. Hence, the chemical nature of the nanoparticle emerges as the dominating factor contributing to the extent of the spectral shift as a result of electron storage in bimetallic systems.
Dependence of Exchange Coupling on Interfacial Conditions in SmCo5/Co System: A First-Principles Study
Authors: Wu Dangxin , Zhang Qiming , Liu Ping J. , Sabirianov Renat F.
Published: June 2008

We have performed first-principles calculations to study the interfacial exchange coupling in a SmCo5/Co multilayer model system. The hard phase hcp SmCo5 and the soft phase hcp Co (or Co1–xFex) stacking along
(101-0) direction are structurally well matched. The atomic structure, including the alignment and the separation between layers, were optimized first. Then the non-collinear magnetic structures were calculated to explore the exchange coupling dependence on the variation of the
atomic composition across the interface. We found that the inter-phase exchange coupling strength is strongly dependent on the interface condition between the hard and soft phase by comparing the exchange coupling strengths in different interface conditions. The findings were further confirmed
by the calculated site-to-site exchange parameters across the interface.
Magnetostatic Interactions and Coercivities of Ferromagnetic Soft Nanowires in Uniform Length Arrays
Authors: Béron F. , Clime L. , Ciureanu M. , Ménard D. , Cochrane R. W. , Yelon A.
Published: June 2008

First-order reversal curve diagrams have been used to investigate magnetostatic interactions and average coercivity of individual wires in soft ferromagnetic uniform length nanowire arrays. We present a method for identifying these physical parameters on the out-of-plane first-order
reversal curve diagrams: the position of the irreversible part on the critical axis is a good approximation to the average value of the nanowire coercivity and the maximum interaction field is equal to the interaction field at saturation. Their dependence upon material (CoFeB and Ni) and nanowire
length are presented. The magnetostatic interactions increase linearly with length, in agreement with a model developed previously. The global array coercivity, obtained from magnetization curves, is generally lower than the apparent average coercivity for individual nanowires. This coercivity
reduction increases linearly with the magnetostatic interactions. The general shape of the out-of-plane first-order reversal curve diagrams is compared with those obtained from a theoretical moving Preisach model.
Size Dependent Interactions of Nanoparticles with Lung Surfactant Model Systems and the Significant Impact on Surface Potential
Authors: Ku Tabitha , Gill Simardeep , Löbenberg Raimar , Azarmi Shirzad , Roa Wilson , Prenner Elmar J.
Published: June 2008

The relationship between a model pulmonary surfactant system and various sized nanoparticles was investigated in this study. Diplamitoylphosphatidylcholine (DPPC) is the main lipid constituent of lung surfactant and has the ability to reach very high surface pressures (around 70 mN/m)
upon compression. Due to these properties it was used as a model to simulate the lung surfactant film in vitro. The first objective of this study was to investigate the relationship between DPPC and various sized nanoparticles within the subphase through surface pressure—area
isotherms. The second objective was to measure the surface potential of the different preparations (conducted on a mini-Langmuir trough) and to determine if an optimal nanoparticle size exists possessing a greater affinity for the DPPC film compared to other sizes. The results from the pressure
area isotherms indicate that the interaction between DPPC and the nanoparticles is stable and that the 235 nm particles may represent an optimal size. Furthermore, the results from the surface potential experiments confirm that an interaction of the nanoparticles with the monolayer exists
as indicated by surface-pressure area isotherms. Any even moderate interaction between nanoparticles and lung surfactant film might reduce or increase the surface potential of the surfactant film, and this might impact the deposition of the nanoparticles or other ligands which may be positively
or negatively charged drugs within the surfactant film. Thus changes in surface potential due to nanoparticle interactions have to be taken into account for future drug targeting studies using nano-sized drug carriers.
Composition Controlled Synthesis and Raman Analysis of Ge-Rich SixGe1–x Nanowires
Authors: Meduri P. , Sumanasekera G. U. , Chen Z. , Sunkara M. K.
Published: June 2008

Here, we report the synthesis of SixGe1–x nanowires with x values ranging from 0 to 0.5 using bulk nucleation and growth from larger Ga droplets. Room temperature Raman spectroscopy is shown to determine the composition of the as-synthesized
SixGe1–x nanowires. Analysis of peak intensities observed for Ge (near 300 cm–1) and the Si-Ge alloy (near 400 cm–1) allowed accurate estimation of composition compared to that based on the absolute peak positions.
The results showed that the fraction of Ge in the resulting SixGe1–x alloy nanowires is controlled by the vapor phase composition of Ge.
Squeeze Casting of Ni Coated SiC Particle Reinforced Al Based Composite
Authors: Tekmen C. , Cocen U.
Published: June 2008

An investigation was carried out on the production of electroless Ni coated 20vol% SiC particle reinforced composite by squeeze casting. The morphology of the coating, microstructural, interfacial, and mechanical properties of the composite were characterized by using an optical microscope, image analyzer, scanning electron microscope (SEM), energy dispersion spectrometer (EDS), and X-ray diffractometer (XRD). The evaluation of microstructure shows that the matrix phase exhibits a pore-free and dentritic structure, and particle segregation. Interfacial examinations indicate that electroless nickel coating has not degraded during the fabrication process and prevent the formation of Al4C3.
Thermal Expansion Behaviors of ZnAl2O4-Coated Aluminum Borate Whiskers Reinforced Aluminum Composites
Authors: Yue H.Y. , Wang L.D. , Fei W.D.
Published: June 2008

Pure aluminum composites reinforced by ZnAl2O4-coated aluminum borate whiskers were fabricated by a squeezing cast technique. Interfacial microstructures of the composites were observed using a transmission electron microscope (TEM). Thermal expansion behaviors of the composites were investigated in the range from 50 to 400°C. Effects of heat-treatment and thermal cycling on the thermal expansion behaviors of the composite were also investigated. The results show that the coefficient of thermal expansion (CTE) of the composites significantly decreases with the coating contents increasing. The average CTE of the composites further decreases after heat-treatment or thermal cycling.
Arrested Contact
Authors: Woldoff Rachael A. , Washington Heather M.
Published: June 2008

Becoming a father is a major benchmark in adulthood. Good parenting means being engaged, nurturing, and helpful, goals that are often shattered for fathers in contact with the criminal justice system. The relationship between this contact and fathering disproportionately affects the lives of unmarried fathers and non-Whites. The authors use Fragile Families survey data to explore fathers' engagement with their children. They extend research on crime and fathering by examining the effects of a range of contacts on the father—child relationship, and examining racial-ethnic differences in such contacts' effects on father engagement. They provide clear evidence that non-Whites are less engaged with their children on average, as are booked or incarcerated fathers. The negative effect of incarceration on engagement is worse for Blacks than Whites and Latinos, and the effect of being booked is worse for Blacks than Whites. The findings have implications for efforts to reintegrate fathers after incarceration.
The Jail and the Community
Authors: Applegate Brandon K. , Sitren Alicia H.
Published: June 2008

Most of the available research on jails focuses on large institutions, located in urban areas. In this study we empirically consider whether this emphasis shortchanges our understanding of jails by comparing 2,638 rural and urban jails on four dimensions: jail size and use, inmate characteristics, staff characteristics, and inmate services. Our results reveal several important cleavages between rural and urban jails. Based on our findings and a conception of jails as influenced in meaningful ways by their social, political, and organizational contexts, we suggest avenues for future research on local incarceration.
The Program Assessment Rating Tool and the Government Performance and Results Act
Authors: Gueorguieva Vassia , Accius Jean , Apaza Carmen , Bennett Lamar , Brownley Clinton , Cronin Shea , Preechyanud Panote
Published: June 2008

This article looks at the Government Performance and Results Act (GPRA) and the Program Assessment Rating Tool (PART) and how they assess seven programs. It establishes that the PART does not adequately consider different program types and has characteristics that create a disconnection between this tool and the GPRA: It does not enter into dialogue with the GPRA regarding the choice of performance indicators; it evaluates programs through criteria that conflict with the programs' statutes or intent and penalizes programs for the degree of explicitness in their authorizing statutes; it uses standardized measures that sometimes overlook the intent of statutes or the discretionary nature of implementation; it employs a different level of analysis from the GPRA; it places a contradictory emphasis on the relationship between programs with similar goals; and it emphasizes different external factors influencing program performance. The article concludes with recommendations on how to improve the PART.
The Relation of Power and Well-Being in Korean Adults
Authors: Tae Sook Kim  , Kim Chungnam , Kyung Min Park  , Yeong Sook Park  , Byoung Sook Lee
Published: June 2008

The researchers examined the relation of power and well-being in a sample of 881 men and women living in South Korea. Rogers' science of unitary human beings, Barrett's theory of power, and Gueldner's theoretical perspective of well-being served as the theoretical rationale. The hypothesis was supported by a significant positive correlation between power and well-being (r = .52, p < .001). Reliabilities by Cronbach's alpha were .96 for the Power as Knowing Participation in Change Tool and .84 for the Well-Being Picture Scale. Well-being can be facilitated by enhancing person's power as knowing participation in change.
The Ethics of Human Dignity: A Nursing Theoretical Perspective
Authors: Milton Constance L.
Published: June 2008

The concept of human dignity is a term commonly used in professional codes and standards for biomedical healthcare disciplines and professional nursing practice. What is the definition of this ethical concept? This column offers a unique definition from a nursing disciplinary perspective. Common straight thinking or ethical questions emerging with the application of the concept in practice are offered along with a discussion of misunderstandings regarding the use of the concept in nursing practice and in professional healthcare arenas.
Nursing Time: Research, Practice, and Theory Dimensions
Authors: Reed Pamela G.
Published: June 2008

Perspectives on time are relevant to knowledge development and professional practice within a discipline. Two scholars present their work on time as related to their programs of nursing research, theory development, and professional practice.
The Role of Relationship Attributions in Relationship Satisfaction Among Cohabiting Gay Men
Authors: Houts Carrie R. , Horne Sharon G.
Published: June 2008

Relationship attributions, how a spouse explains his or her partner's behavior, were examined using a sample of cohabiting gay males (N = 175) in relationships of at least 6 months. The psychometric properties of the most commonly used attribution measure were investigated with this new population and found to be adequate through confirmatory and exploratory factor analyses. Analyses from heterosexual married couples regarding the association between relationship satisfaction, attributions, and negative affectivity were replicated in this sample using structural equation modeling. The findings from the gay male sample differed from what has been found in previous research with heterosexual couples; neither relationship attributions of causality or responsibility were strongly linked to relationship satisfaction. Counseling implications and directions for future research are discussed.
The United States and International Water Policy
Authors: Conca Ken
Published: June 2008

This article examines the role of the United States in international institutions and practices for governing water. Water is a critical global challenge of environmental protection and human security. Water is also characteristic of a set of “translocal” environmental issues for which international institution building has emerged along several different fronts: development assistance initiatives, efforts to manage ongoing controversies over water privatization and large dams, the campaign to recognize water as a human right, and a framework convention on cooperation in internationally shared river basins. U.S. engagement across these initiatives reveals several patterns: the fragmented nature of U.S. policies on water, a systematic tilt toward framing water as a market commodity rather than as a human right, the late arrival of U.S. nongovernmental organizations to several important domains of global water politics, and some notable gaps between U.S. policies, at home and abroad, and evolving international concepts of best practice.
Health Behavior and Academic Achievement Among Adolescents: The Relative Contribution of Dietary Habits, Physical Activity, Body Mass Index, and Self-Esteem
Authors: Logi Kristjánsson Álfgeir , Dóra Sigfúsdóttir Inga , Allegrante John P.
Published: June 2008

This study tested a structural equation model to estimate the relationship between health behaviors, body mass index (BMI), and self-esteem and the academic achievement of adolescents. The authors analyzed survey data from the 2000 study of Youth in Iceland , a population-based, cross-sectional sample of 6,346 adolescents in Iceland. The model demonstrated good fit with chi-square of 2685 ( n = 5,810, df = 180), p < .001, Comparative Fit Index value of .94, and a root mean square error of approximation of .049. Lower BMI, physical activity, and good dietary habits were all associated with higher academic achievement; however, health behavior was positively and robustly associated with greater self-esteem. Self-esteem was positively influenced both through physical activity (β = .16) and the consumption of fruits and vegetables (β = .14). In contrast, poor dietary habits negatively influenced self-esteem and academic achievement, and self-esteem was negatively influenced by increasing levels of BMI (β = —.05).
The Design of Member Review
Authors: Locke Karen , Ramakrishna Velamuri S.
Published: June 2008

Noting various forces prompting qualitative researchers to incorporate some form of member review into their studies, this article aims to help researchers anticipate and develop their own considered strategies for designing and executing this process. Drawing on existing discussions of member review in the sociological and anthropological literature, the article develops a framework that suggests different ways in which member reviews might be designed and executed, it outlines the types of challenges researchers may anticipate during execution of the designs and highlights the positive and negative influences that creating the opportunity for such challenges can have on the research. A dissertation-based case study illustrates how challenges to the research arising from execution of a particular member review design unfolded in practice and forms the basis for considering how researchers might respond when research participants take exception to what we write.
Psychological Ownership Theory: An Exploratory Application in the Restaurant Industry
Authors: Asatryan Vahagn S. , Oh Haemoon
Published: June 2008

This exploratory study conceptualizes psychological ownership (PO)—a state in which individuals feel as though the target of ownership is theirs—and investigates how customers form PO toward a company. Considering the PO is a new concept to hospitality research, the study develops and empirically validates a conceptual model of PO and a PO measurement scale in the context of the restaurant industry. The model incorporates fundamental human relationship variables, such as sense of belonging, identification, and perceived control, as the antecedents of PO. The model also relates PO to several practically important consequences, such as relationship intentions, word-of-mouth communications, competitive resistance, and willingness to pay. The results generally support the proposed mediating role of PO between the antecedents and consequences, consistent with the initial conceptualizations. This study discusses the potential that PO may play in enhancing loyalty and relationship marketing research in the hospitality and tourism industry.
Family Responsibilities Among Latina College Students From Immigrant Families
Authors: Sy Susan R. , Romero Jessica
Published: June 2008

The purpose of this study was to examine different types of family responsibilities among Latina college students and how these responsibilities affect their college experiences. Semi-structured interviews were conducted with 20 first- and second-generation Latina women, aged 18 to 29. Results point to three key emergent themes regarding the role of family responsibility, which are discussed in the context of Latina students' college adjustment and retention.
Sphingosine-1-phosphate promotes lymphangiogenesis by stimulating S1P1/Gi/PLC/Ca2+ signaling pathways
Authors: Yoon Chang Min , Hong Bok Sil , Moon Hyung Geun , Lim Seyoung , Suh Pann-Ghill , Kim Yoon-Keun , Chae Chi-Bom , Gho Yong Song
Published: June 2008

The lymphatic system plays pivotal roles in mediating tissue fluid homeostasis and immunity, and excessive lymphatic vessel formation is implicated in many pathological conditions, which include inflammation and tumor metastasis. However, the molecular mechanisms that regulate lymphatic vessel formation remain poorly characterized. Sphingosine-1-phosphate (S1P) is a potent bioactive lipid that is implicated in a variety of biologic processes such as inflammatory responses and angiogenesis. Here, we first report that S1P acts as a lymphangiogenic mediator. S1P induced migration, capillary-like tube formation, and intracellular Ca2+ mobilization, but not proliferation, in human lymphatic endothelial cells (HLECs) in vitro. Moreover, a Matrigel plug assay demonstrated that S1P promoted the outgrowth of new lymphatic vessels in vivo. HLECs expressed S1P1 and S1P3, and both RNA interference–mediated down-regulation of S1P1 and an S1P1 antagonist significantly blocked S1P-mediated lymphangiogenesis. Furthermore, pertussis toxin, U73122, and BAPTA-AM efficiently blocked S1P-induced in vitro lymphangiogenesis and intracellular Ca2+ mobilization of HLECs, indicating that S1P promotes lymphangiogenesis by stimulating S1P1/Gi/phospholipase C/Ca2+ signaling pathways. Our results suggest that S1P is the first lymphangiogenic bioactive lipid to be identified, and that S1P and its receptors might serve as new therapeutic targets against inflammatory diseases and lymphatic metastasis in tumors.
Leukocyte trafficking in a mouse model for leukocyte adhesion deficiency II/congenital disorder of glycosylation IIc
Authors: Yakubenia Sviatlana , Frommhold David , Schölch Dirk , Hellbusch Christina C. , Körner Christian , Petri Björn , Jones Claire , Ipe Ute , Bixel M. Gabriele , Krempien Robert , Sperandio Markus , Wild Martin K.
Published: June 2008

Leukocyte adhesion deficiency II (LAD II), also known as congenital disorder of glycosylation IIc (CDG-IIc), is a human disease in which a defective GDP-fucose transporter (SLC35C1) causes developmental defects and an immunodeficiency that is based on the lack of fucosylated selectin ligands. Since the study of in vivo leukocyte trafficking in patients with LAD II is experimentally limited, we analyzed this process in mice deficient for Slc35c1. We found that E-, L-, and P-selectin–dependent leukocyte rolling in cremaster muscle venules was virtually absent. This was accompanied by a strong but not complete decrease in firm leukocyte adhesion. Moreover, neutrophil migration to the inflamed peritoneum was strongly reduced by 89%. Previous reports showed surprisingly normal lymphocyte functions in LAD II, which indicated sufficient lymphocyte trafficking to secondary lymphoid organs. We now found that while lymphocyte homing to lymph nodes was reduced to 1% to 2% in Slc35c1−/− mice, trafficking to the spleen was completely normal. In accordance with this, we found a defect in the humoral response to a T cell–dependent antigen in lymph nodes but not in the spleen. Taken together, Slc35c1−/− mice show strongly defective leukocyte trafficking but normal lymphocyte homing to the spleen, which may explain normal lymphocyte functions in LAD II.
Vorinostat inhibits STAT6-mediated TH2 cytokine and TARC production and induces cell death in Hodgkin lymphoma cell lines
Authors: Buglio Daniela , Georgakis Georgios V. , Hanabuchi Shino , Arima Kazuhiko , Khaskhely Noor M. , Liu Yong-Jun , Younes Anas
Published: June 2008

Epigenetic changes have been implicated in silencing several B-cell genes in Hodgkin and Reed-Sternberg cells (HRS) of Hodgkin lymphoma (HL), and this mechanism has been proposed to promote HRS survival and escape from immunosurveillance. However, the molecular and functional consequences of histone deacetylase (HDAC) inhibition in HL have not been previously described. In this study, we report that the HDAC inhibitor vorinostat induced p21 expression and decreased Bcl-xL levels causing cell-cycle arrest and apoptosis. Furthermore, vorinostat inhibited STAT6 phosphorylation and decreased its mRNA levels in a dose- and time-dependent manner, which was associated with a decrease in the expression and secretion of Thymus and Activation-Regulated Chemokine (TARC/CCL17) and interleukin (IL)–5 and an increase in IP-10 levels. Moreover, vorino-stat inhibited TARC secretion by dendritic cells that were activated by the thymic stromal lymphopoietin (TSLP). Collectively, these data suggest that pharmacologic HDAC inhibition in HL may induce favorable antitumor activity by a direct antiproliferative effect on HRS cells, and possibly by an immune mediated effect by altering cytokine and chemokines secretion in the microenvironment.
The C-type lectin surface receptor DCIR acts as a new attachment factor for HIV-1 in dendritic cells and contributes to trans- and cis-infection pathways
Authors: Lambert Alexandra A. , Gilbert Caroline , Richard Manon , Beaulieu André D. , Tremblay Michel J.
Published: June 2008

The dynamic interplay between dendritic cells (DCs) and human immunodeficiency virus type-1 (HIV-1) is thought to result in viral dissemination and evasion of antiviral immunity. Although initial observations suggested that the C-type lectin receptor (CLR) DC-SIGN was responsible for the trans-infection function of the virus, subsequent studies demonstrated that trans-infection of CD4+ T cells with HIV-1 can also occur through DC-SIGN–independent mechanisms. We demonstrate that a cell surface molecule designated DCIR (for DCimmunoreceptor), a member of a recently described family of DC-expressing CLRs, can participate in the capture of HIV-1 and promote infection in trans and in cis of autologous CD4+ T cells from human immature monocyte-derived DCs. The contribution of DCIR to these processes was revealed using DCIR-specific siRNAs and a polyclonal antibody specific for the carbohydrate recognition domain of DCIR. Data from transfection experiments indicated that DCIR acts as a ligand for HIV-1 and is involved in events leading to productive virus infection. Finally, we show that the neck domain of DCIR is important for the DCIR-mediated effect on virus binding and infection. These results point to a possible role for DCIR in HIV-1 pathogenesis by supporting the productive infection of DCs and promoting virus propagation.
Inhibition of TLR3 and TLR4 function and expression in human dendritic cells by helminth parasites
Authors: Semnani Roshanak Tolouei , Venugopal Priyanka Goel , Leifer Cynthia A. , Mostböck Sven , Sabzevari Helen , Nutman Thomas B.
Published: June 2008

Patent lymphatic filariasis is characterized by antigen-specific T-cell unresponsiveness with diminished IFN-γ and IL-2 production and defects in dendritic cell (DC) function. Because Toll-like receptors (TLRs) play an important role in pathogen recognition and TLR expression is diminished on B and T cells of filaria-infected individuals, we examined the effect of live microfilariae (mf) on expression and function of TLRs in human DCs. We show that mf-exposed monocyte-derived human DCs (mhDCs) demonstrate marked diminution of TLR3 and TLR4 mRNA expression compared with mf-unexposed mhDCs that translated into loss of function in response to appropriate TLR ligands. Exposure to mf significantly down-regulated production of IFN-α, MIP-1α, IL-12p70, and IL-1α following activation with poly I:C, and of IL-12p40 following activation with poly I:C or LPS. mRNA expression of MyD88, the adaptor molecule involved in TLR4 signaling, was significantly diminished in mhDCs after exposure to mf. Moreover, mf interfered with NF-κB activation (particularly p65 and p50) following stimulation with poly I:C or LPS. These data suggest that mf interfere with mhDC function by altering TLR expression and interfering with both MyD88-dependent signaling and a pathway that ultimately diminishes NF-κB activity. This down-regulated NF-κB activity impairs mhDC-produced cytokines needed for full T-cell activation.
Characterization of Bacillus anthracis arginase: effects of pH, temperature, and cell viability on metal preference
Authors: Viator Ryan J , Rest Richard F , Hildebrandt Ellen , McGee David J
Published: June 2008

Background

Arginase (RocF) hydrolyzes L-arginine to L-ornithine and urea. While previously characterized arginases have an alkaline pH optimum and require activation with manganese, arginase from Helicobacter pylori is optimally active with cobalt at pH 6. The arginase from Bacillus anthracis is not well characterized; therefore, this arginase was investigated by a variety of strategies and the enzyme was purified.

Results

The rocF gene from B. anthracis was cloned and expressed in E. coli and compared with E. coli expressing H. pylori rocF. In the native organisms B. anthracis arginase was up to 1,000 times more active than H. pylori arginase and displayed remarkable activity in the absence of exogenous metals, although manganese, cobalt, and nickel all improved activity. Optimal B. anthracis arginase activity occurred with nickel at an alkaline pH. Either B. anthracis arginase expressed in E. coli or purified B. anthracis RocF showed similar findings. The B. anthracis arginase expressed in E. coli shifted its metal preference from Ni > Co > Mn when assayed at pH 6 to Ni > Mn > Co at pH 9. Using a viable cell arginase assay, B. anthracis arginase increased dramatically when the cells were grown with manganese, even at final concentrations of <1 μM, whereas B. anthracis grown with cobalt or nickel (≥500 μM) showed no such increase, suggesting existence of a high affinity and specificity manganese transporter.

Conclusion

Unlike other eubacterial arginases, B. anthracis arginase displays unusual metal promiscuity. The unique properties of B. anthracis arginase may allow utilization of a specific metal, depending on the in vivo niches occupied by this organism.