bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of the color of the substratum on the initiation of the probing behavior in Myzus persicae (Sulzer) and Macrosiphum euphorbiae (Thomas) (Homoptera: Aphididae)
Authors: Pelletier Yvan
Published: August 2008

Twenty-five colors were evaluated for their effect on the initiation of probing behavior in the green peach aphid, Myzus persicae (Sulzer), and the potato aphid, Macrosiphum euphorbiae (Thomas). The proportion of aphids of both species initiating probing behavior was maximum on green, yellow, or orange and lowest on purple, blue, white, or black. The time taken by individual aphids to begin probing was shorter for M. persicae than for M. euphorbiae but was essentially unaffected by colors. A larger proportion of both aphid species probed on the lower surface of potato (var. Kathadin) leaflet compared with the upper surface. The proportion of aphids initiating probing was the same on the lower surface of a potato leaf and on paper similar in color, indicating that the color of the substratum is determinant in the initiation of feeding for those aphids.
Aspects of jet propulsion in salps
Authors: Madin L. P.
Published: August 2008

Several morphological and functional characteristics that affect the jet propulsion of salps are described, based on observations of living animals in situ and in the laboratory. A velocity profile of water flowing through the salp and its feeding net is determined from video frames, and velocities of the jet efflux are related to forward movement of the animal. Analysis of the size and spacing of vortices in the jet trail indicates that the theoretical augmentation of thrust from a pulsed jet may indeed affect the locomotory efficiency of salps. The external morphology of several species of solitary-generation salps indicates selection for streamlining in most, and the architecture of the chains of aggregate-generation individuals has a significant effect on their locomotory capability. Calculated costs of locomotion for several salp species are lower than for all other jet-propelled organisms. Differing locomotory capabilities and their consequences may be one of the main characteristics that isolate species of salps.
Size-related hydrodynamic characteristics of the giant scallop, Placopecten magellanicus (Bivalvia: Pectinidae)
Authors: Dadswell Michael J. , Weihs Daniel
Published: August 2008

The giant scallop, Placopecten magellanicus (Gmelin, 1791), exhibits a three-stage life history: an early sedentary phase with byssal attachment (1–30 mm shell height), a motile phase (30–100 mm), and a later, sedentary phase, recessed in the bottom (100–160 mm). If hydrodynamics have an adaptive advantage, ontogeny of form and functional kinetics should reflect changes in life stage, and medium-sized Placopecten would be the best swimmers, with optimum hydrodynamic characteristics. Comparison of morphological characteristics of P. magellanicus in relation to size (5–160 mm) suggested that peak hydrodynamic efficiency for this species occurs between 40 and 80 mm shell height. Fineness, aspect ratio, wing loading, and potential power relationships were optimal in this range. Underwater video sequences of swimming Placopecten revealed that the angle of valve opening during sustained level flight averaged 9° per contraction and calculated jet volume expelled per unit weight peaked at 55 mm shell height. Swimming Placopecten between 30 and 100 mm exhibited a steep angle of attack only during takeoff and then swam level at velocities of 30–60 cm/s (4–9 body lengths/s), with associated Reynolds numbers of 0.6–7.2 × 104. Swimming speed, both absolute and adjusted for body length, was maximal between 50 and 70 mm shell height. Calculated Reynolds numbers increased for individuals between 30 and 70 mm but remained constant for those over 70 mm.
Marine Chemical Ecology: Chemical Signals and Cues Structure Marine Populations, Communities, and Ecosystems
Authors: Hay Mark E.
Published: August 2008

Chemical cues constitute much of the language of life in the sea. Our understanding of biotic interactions and their effects on marine ecosystems will advance more rapidly if this language is studied and understood. Here, I review how chemical cues regulate critical aspects of the behavior of marine organisms from bacteria to phytoplankton to benthic invertebrates and water column fishes. These chemically mediated interactions strongly affect population structure, community organization, and ecosystem function. Chemical cues determine foraging strategies, feeding choices, commensal associations, selection of mates and habitats, competitive interactions, and transfer of energy and nutrients within and among ecosystems. In numerous cases, the indirect effects of chemical signals on behavior have as much or more effect on community structure and function as the direct effects of consumers and pathogens. Chemical cues are critical for understanding marine systems, but their omnipresence and impact are inadequately recognized.
β2-Integrins contribute to skeletal muscle hypertrophy in mice
Authors: Marino Joseph S. , Tausch Brian J. , Dearth Christopher L. , Manacci Marc V. , McLoughlin Thomas J. , Rakyta Samuel J. , Linsenmayer Matthew P. , Pizza Francis X.
Published: August 2008

We tested the contribution of β2-integrins, which are important for normal function of neutrophils and macrophages, to skeletal muscle hypertrophy after mechanical loading. Using the synergist ablation model of hypertrophy and mice deficient in the common β-subunit of β2-integrins (CD18−/−), we found that overloaded muscles of wild-type mice had greater myofiber size, dry muscle mass, and total protein content compared with CD18−/− mice. The hypertrophy in wild-type mice was preceded by elevations in neutrophils, macrophages, satellite cell/myoblast proliferation (5′-bromo-2′-deoxyuridine- and desmin-positive cells), markers of muscle differentiation (MyoD1 and myogenin gene expression and formation and size of regenerating myofibers), signaling for protein synthesis [phosphorylation of Akt and 70-kDa ribosomal protein S6 kinase (p70S6k)], and reduced signaling for protein degradation (decreased gene expression of muscle atrophy F box/atrogin-1). The deficiency in β2-integrins, however, altered the accumulation profile of neutrophils and macrophages, disrupted the temporal profile of satellite cell/myoblast proliferation, reduced the markers of muscle differentiation, and impaired the p70S6k signaling, all of which could serve as mechanisms for the impaired hypertrophy in overloaded CD18−/− mice. In conclusion, our findings indicate that β2-integrins contribute to the hypertrophic response to muscle overload by temporally regulating satellite cells/myoblast proliferation and by enhancing muscle differentiation and p70S6k signaling.
Intact renal afferent arteriolar autoregulatory responsiveness in db/db mice
Authors: Park Sungmi , Bivona Benjamin J. , Feng Yumei , Lazartigues Eric , Harrison-Bernard Lisa M.
Published: August 2008

The db/ db mouse is a genetic model of type 2 diabetes that exhibits progressive renal disease. Obesity, hyperglycemia, and albuminuria (822 ± 365 vs. 28 ± 8 μg/day) are evident in 18-wk-old db/ db compared with db/ m (lean littermate control) mice. Our goal was to determine the blood pressure (BP) phenotype of the db/ db mouse. Mean arterial BP measured in conscious mice by radiotelemetry was not different between db/ db ( n = 9) and db/ m ( n = 12) mice, averaging 113 ± 3 and 112 ± 2 mmHg, respectively. The circadian BP profile of db/ db mice was shifted to the left and exhibited a significant reduction in amplitude compared with db/ m mice. Heart rate (487 ± 9 vs. 542 ± 7 beats/min; P < 0.05) and locomotor activity were significantly reduced in db/ db compared with db/ m mice. We tested the hypothesis that intact afferent arteriole (AA) responsiveness to increases in renal artery pressure (RAP) and angiotensin (ANG) II sensitivity contributes to normal BP in this diabetic model. AA diameters of in vitro blood-perfused juxtamedullary nephrons of db/ db mice (15.7 ± 0.5 μm; n = 38) were significantly larger than those of db/ m mice (12.5 ± 0.4 μm; n = 37). AA responses to increases in RAP and ANG II were not different between kidneys of db/ db and db/ m mice. Significant AA vasoconstriction to 1 nM ANG II was observed in kidneys of db/ db mice (−11 ± 4%), while 10 nM ANG II decreased AA diameter in both groups [ db/ db, −20 ± 4%, ( n = 12); db/ m, −26 ± 4% ( n = 12)]. In summary, AA responses to increases in renal perfusion pressure and ANG II remain intact in db/ db mice. Diabetic renal disease occurs in db/ db mice independently of elevated BP.
Spatial Relationships of Visuomotor Transformations in the Superior Colliculus Map
Authors: Marino Robert A. , Rodgers C. Kip , Levy Ron , Munoz Douglas P.
Published: August 2008

The oculomotor system is well understood compared with other motor systems; however, we do not yet know the spatial details of sensory to motor transformations. This study addresses this issue by quantifying the spatial relationships between visual and motor responses in the superior colliculus (SC), a midbrain structure involved in the transformation of visual information into saccadic motor command signals. We collected extracellular single-unit recordings from 150 visual-motor (VM) and 28 motor (M) neurons in two monkeys trained to perform a nonpredictive visually guided saccade task to 110 possible target locations. Motor related discharge was greater than visual related discharge in 94% (141/150) of the VM neurons. Across the population of VM neurons, the mean locations of the peak visual and motor responses were spatially aligned. The visual response fields (RFs) were significantly smaller than and usually contained within the motor RFs. Converting RFs into the SC coordinate system significantly reduced any misalignment between peak visual and motor locations. RF size increased with increasing eccentricity in visual space but remained invariant on the SC map beyond 1 mm of the rostral pole. RF shape was significantly more symmetric in SC map coordinates compared with visual space coordinates. These results demonstrate that VM neurons specify the same location of a target stimulus in the visual field as the intended location of an upcoming saccade with minimal misalignment to downstream structures. The computational consequences of spatially transforming visual field coordinates to the SC map resulted in increased alignment and spatial symmetry during visual-sensory to saccadic-motor transformations.
Omega‐3 Fatty Acids and PPARγ in Cancer
Authors: Edwards Iris J. , O′Flaherty Joseph T.
Published: August 2008

Omega‐3 (or n‐3) polyunsaturated fatty acids (PUFAs) and their metabolites are natural ligands for peroxisome proliferator receptor activator (PPAR)γ and, due to the effects of PPARγ on cell proliferation, survival, and differentiation, are potential anticancer agents. Dietary intake of omega‐3 PUFAs has been associated with a reduced risk of certain cancers in human populations and in animal models. In vitro studies have shown that omega‐3 PUFAs inhibit cell proliferation and induce apoptosis in cancer cells through various pathways but one of which involves PPARγ activation. The differential activation of PPARγ and PPARγ‐regulated genes by specific dietary fatty acids may be central to their distinct roles in cancer. This review summarizes studies relating PUFAs to PPARγ and cancer and offers a new paradigm relating an n‐3 PUFA through PPARγ to the expression of the cell surface proteoglycan, syndecan‐1, and to the death of cancer cells.
Chemotherapy Administration during Pelvic Radiation for Cervical Cancer Patients Aged ≥ 55 Years in the SEER-Medicare Population
Authors: Kunos Charles , Gibbons Heidi , Simpkins Fiona , Waggoner Steven
Published: August 2008

Our study evaluated whether 1999 National Cancer Institute (NCI) chemoradiation guidelines for cervical cancer impacted treatment of women ≥55 years. We identified 385 women ≥55 years (median, 72 years) diagnosed with stage II-IVA cervical cancer between January, 1998 and December, 2002 in the United States Surveillance, Epidemiology, and End Results (SEER)-Medicare registries. Chemoradiation frequency tables were constructed for age, race, community setting, socioeconomic status, and comorbidity index. Of 385 women, 166 (43%) received chemoradiation as primary treatment. Prior to the 1999 NCI clinical alert, 5/43 (12%) in 1998 and 24/54 (44%) in 1999 received chemoradiation. The chemoradiation proportion was 41% (36/87) in 2000, 48% (51/107) in 2001, and 53% (50/94) in 2002 (trend,P<.01). Women ≥71 years had significantly lower odds of chemoradiation (P=.04). While SEER-Medicare data indicated an increasing trend for chemoradiation after the 1999 NCI clinical alert, chemoradiation was less frequent in elderly women with cervical cancer.
Empirical Modeling of Layered Integrated Water Vapor Using Surface Mixing Ratio in Nigeria
Authors: Adeyemi B.
Published: August 2008

Using the available upper-air data for three stations in Nigeria (Lagos, a coastal station; Minna, an inland station; and Kano, a sub-Sahelian station), an intensive examination has been carried out on the linkage between surface mixing ratio rs and layered integrated water vapor W (g cm−2) over Nigeria. The goal was to identify the seasonal distribution of the parameter and to develop models that can best be used to estimate W from surface mixing ratio. To achieve these objectives, integrated water vapor at the low level (WL), midlevel (Wm), and upper level (Wu) and total column integrated water WT have been calculated using daily values of upper-air data spanning over a decade from the above three radiosonde stations. A relationship of the form W = αrs + β (where α and β are constants) has been established between W and rs using the analysis-of-variance (ANOVA) technique. Tests carried out on the models, using daily soundings made in 1990 for Lagos, 1983 for Minna, and 1991 for Kano, respectively, gave encouraging results as established by the use of Kolmogorov–Smirnov tests. Owing to the difference in the climatological patterns of precipitation among the different regions in Nigeria (i.e., southern, midland, and northern regions) as represented by the three stations, no single relationship was found to be suitable for the entire country of Nigeria. Earlier models, generally of the form W = αqb (where α and b are constants and q is specific humidity), were found to be less adequate over the stations.
Long-Term Free-Atmosphere Temperature Trends in China Derived from Homogenized In Situ Radiosonde Temperature Series
Authors: Guo Yanjun , Ding Yihui
Published: August 2008

In this paper, radiosonde temperature time series (RTT) from 1958 to 2005 collected by the 116-station Chinese radiosonde network are examined. Quality control and homogenization are used to obtain a reliable RTT. The homogenization results revealed significant discontinuities in the RTT. Analysis suggested that 70% data availability is the minimum data requirement (MDR) for these RTTs. A new dataset is built by meeting this MDR, which reduced the number of potential stations from 116 to 92. Analysis on this dataset reveals that warming trends in the troposphere and cooling trends in the stratosphere were weakened by reducing the stations. Averaged RTT trends for China were generally consistent with those of global scale, but with some discrepancies. During 1958–2005, averaged temperatures in China tended to decrease in the lower stratosphere and upper troposphere, in contrast to warming trends in the mid- and lower troposphere. The trends varied with two different subperiods. For 1958–78, cooling trends in the entire atmosphere were similar to trends at the global scale. For 1979–2005, warming occurred in the lower troposphere, with the amplitude of the warming tending to weaken with increases in altitude and shifting to a cooling trend above 400 hPa. Seasonal trend structures suggest that warming in the lower troposphere is attributable to temperature increases in December–February (DJF); cooling in the upper troposphere and stratosphere was found mainly in June–August (JJA). Unlike with results of a larger spatial scale, a robust cooling layer was found around 300 hPa.
Calculating Energy Flux in Internal Solitary Waves with an Application to Reflectance
Authors: Lamb Kevin G. , Nguyen Van T.
Published: August 2008

The energetics of internal solitary waves (ISWs) in continuous, quasi-two-layer stratifications are explored using fully nonlinear, nonhydrostatic numerical simulations. The kinetic energy of an internal solitary wave is always greater than the available potential energy, by as much as 30% for the stratifications considered. Because of different spatial distributions of the kinetic and available potential energy densities, however, the fluxes are quite different. The available potential energy flux is found to always exceed the kinetic energy flux, by as much as a factor of 5. The sizes of the various fluxes in the wave pseudoenergy (kinetic plus available potential energy) equation are compared, showing that, while the linear flux term (velocity–pressure perturbation) dominates the fluxes, the fluxes of available potential and kinetic energy are significant for large ISWs. Past work on estimating the reflectance (ratio of reflected to incident pseudoenergy flux) associated with internal solitary waves incident on a linearly sloping bottom in laboratory experiments and numerical simulations has incorrectly assumed that the available potential energy flux was equal to the kinetic energy flux. Hence, the sensitivity of reflectance estimates to the way the flux is calculated is investigated. For these low Reynolds number situations, it is found that a correct account of the available potential energy flux reduces the reflectance by as much as 0.1 when the pycnocline is close to the surface.
Nonlinear Advection Algorithms Applied to Interrelated Tracers: Errors and Implications for Modeling Aerosol–Cloud Interactions
Authors: Ovtchinnikov Mikhail , Easter Richard C.
Published: August 2008

Monotonicity constraints and gradient-preserving flux corrections employed by many advection algorithms used in atmospheric models make these algorithms nonlinear. Consequently, any relations among model variables transported separately are not necessarily preserved in such models. These errors cannot be revealed by traditional algorithm testing based on advection of a single tracer. New types of tests are developed and conducted to evaluate the monotonicity of a sum of several number mixing ratios advected independently of each other—as is the case, for example, in models using bin or sectional representations of aerosol or cloud particle size distributions. The tests show that when three tracers with an initially constant sum are advected separately in one-dimensional constant velocity flow, local errors in their sum can be on the order of 10%. When cloudlike interactions are allowed among the tracers in the idealized “cloud base” test, errors in the sum of three mixing ratios can reach 30%. Several approaches to eliminate the error are suggested, all based on advecting the sum as a separate variable and then using it to normalize the sum of the individual tracers’ mixing ratios or fluxes. A simple scalar normalization ensures the monotonicity of the total number mixing ratio and positive definiteness of the variables, but the monotonicity of individual tracers is no longer maintained. More involved flux normalization procedures are developed for the flux-based advection algorithms to maintain the monotonicity for individual scalars and their sum.
Management of the obese child — Application of NICE guidelines 2006
Authors: Matyka Krystyna A , Malik Shital
Published: August 2008

The increasing prevalence of overweight and obesity worldwide has prompted interest in the condition. Of particular concern is the increase of excess adiposity, often accompanied by reduced physical activity, in the young. In 2006 the National Institute for health and Clinical Excellence (NICE) published guidance on the identification, assessment and management of overweight and obesity in adults and children. Herein we aim to describe the approach to management of a severely obese child using the NICE guidelines and personal practice from a secondary care weight management clinic. Br J Diabetes Vasc Dis 2008; 8: 178—182
Mononuclear myeloid-derived “suppressor” cells express RAE-1 and activate natural killer cells
Authors: Nausch Norman , Galani Ioanna E. , Schlecker Eva , Cerwenka Adelheid
Published: August 2008

Myeloid-derived suppressor cells (MDSCs) accumulate in cancer patients and tumor-bearing mice and potently suppress T-cell activation. In this study, we investigated whether MDSCs regu-late natural killer (NK)–cell function. We discovered that mononuclear Gr-1+CD11b+F4/80+ MDSCs isolated from RMA-S tumor-bearing mice do not suppress, but activate NK cells to produce high amounts of IFN-γ. Gr-1+CD11b+F4/80+ MDSCs isolated from tumor-bearing mice, but not myeloid cells from naive mice, expressed the ligand for the activating receptor NKG2D, RAE-1. NK-cell activation by MDSCs depended partially on the interaction of NKG2D on NK cells with RAE-1 on MDSCs. NK cells eliminated Gr-1+CD11b+F4/80+ MDSCs in vitro and upon adoptive transfer in vivo. Finally, depletion of Gr-1+ cells that comprise MDSCs confirmed their protective role against the NK-sensitive RMA-S lymphoma in vivo. Our study reveals that MDSCs do not suppress all aspects of antitumor immune responses and defines a novel, unexpected activating role of MDSCs on NK cells. Thus, our results have great impact on the design of immune therapies against cancer aiming at the manipulation of MDSCs.
Effect of roflumilast on inflammatory cells in the lungs of cigarette smoke-exposed mice
Authors: Martorana Piero A , Lunghi Benedetta , Lucattelli Monica , De Cunto Giovanna , Beume Rolf , Lungarella Giuseppe
Published: August 2008

Background

We reported that roflumilast, a phosphodiesterase 4 inhibitor, given orally at 5 mg/kg to mice prevented the development of emphysema in a chronic model of cigarette smoke exposure, while at 1 mg/kg was ineffective. Here we investigated the effects of roflumilast on the volume density (VV) of the inflammatory cells present in the lungs after chronic cigarette smoke exposure.

Methods

Slides were obtained from blocks of the previous study and VV was assessed immunohistochemically and by point counting using a grid with 48 points, a 20× objective and a computer screen for a final magnification of 580×. Neutrophils were marked with myeloperoxidase antibody, macrophages with Mac-3, dendritic cells with fascin, B-lymphocytes with B220, CD4+ T-cells with CD4+ antibody, and CD8+T-cells with CD8-α. The significance of the differences was calculated using one-way analysis of variance.

Results

Chronic smoke exposure increased neutrophil VV by 97%, macrophage by 107%, dendritic cell by 217%, B-lymphocyte by 436%, CD4+ by 524%, and CD8+ by 417%. The higher dose of roflumilast prevented the increase in neutrophil VV by 78%, macrophage by 82%, dendritic cell by 48%, B-lymphocyte by 100%, CD4+ by 98% and CD8+ VV by 88%. The lower dose of roflumilast did not prevent the increase in neutrophil, macrophage and B-cell VV but prevented dendritic cells by 42%, CD4+ by 55%, and CD8+ by 91%.

Conclusion

These results indicate (i) chronic exposure to cigarette smoke in mice results in a significant recruitment into the lung of inflammatory cells of both the innate and adaptive immune system; (ii) roflumilast at the higher dose exerts a protective effect against the recruitment of all these cells and at the lower dose against the recruitment of dendritic cells and T-lymphocytes; (iii) these findings underline the role of innate immunity in the development of pulmonary emphysema and (iiii) support previous results indicating that the inflammatory cells of the adaptive immune system do not play a central role in the development of cigarette smoke induced emphysema in mice.
Role of neutrophil proteinase 3 and mast cell chymase in chemerin proteolytic regulation
Authors: Guillabert Aude , Wittamer Valérie , Bondue Benjamin , Godot Véronique , Imbault Virginie , Parmentier Marc , Communi David
Published: August 2008

Chemerin is a potent chemotactic factor that was identified recently as the ligand of ChemR23, a G protein-coupled receptor expressed by mononuclear phagocytes, dendritic cells (DCs), and NK cells. Chemerin is synthesized as a secreted precursor, prochemerin, which is poorly active on ChemR23. However, prochemerin can be converted rapidly into a full ChemR23 agonist by proteolytic removal of a carboxy-terminal peptide. This maturation step is mediated by the neutrophil-derived serine proteases elastase and cathepsin G. In the present work, we have investigated proteolytic events that negatively control chemerin activity. We demonstrate here that neutrophil-derived proteinase 3 (PR3) and mast cell (MC) chymase are involved in the generation of specific chemerin variants, which are inactive, as they do not induce calcium release or DC chemotaxis. Mass spectrometry analysis showed that PR3 specifically converts prochemerin into a chemerin form, lacking the last eight carboxy-terminal amino acids, and is inactive on ChemR23. Whereas PR3 had no effect on bioactive chemerin, MC chymase was shown to abolish chemerin activity by the removal of additional amino acids from its C-terminus. This effect was shown to be specific to bioactive chemerin (chemerin-157 and to a lesser extent, chemerin-156), as MC chymase does not use prochemerin as a substrate. These mechanisms, leading to the production of inactive variants of chemerin, starting from the precursor or the active variants, highlight the complex interplay of proteases regulating the bioactivity of this novel mediator during early innate immune responses.
The First International Symposium on Cultic Studies, Shenzhen, China
Authors: Cowan Douglas E. , Moore Rebecca
Published: August 2008

This article describes the First International Symposium on Cultic Studies, sponsored by the Institute of World Religions of the Chinese Academy of Social Sciences in Beijing. Two North American participants narrate their encounter with Chinese scholars, whose views about new religions diverge markedly from those in the West. The symposium revealed the various attempts by which "cults" are defined and understood by Asian scholars, and demonstrated a concern for protecting individuals from harm and for maintaining a stable society. Taking primarily a psychological rather than a sociological perspective, many conference participants focused on individual pathologies and charismatic leaders, although there were notable exceptions. The symposium revealed an openness to listen and to engage in dialogue by all participants that promises profitable exchanges in the future.
Combustion synthesis of ultrafine tungsten carbide powder
Authors: Won H.I. , Nersisyan H.H. , Won C.W.
Published: August 2008

The synthesis of ultrafine tungsten carbide (WC) powder has been investigated from a WO3 + Mg + C mixture via combustion technique. The values of combustion parameters were estimated over the Mg concentration range 3 to 16 mol. Fast increasing tendency of the WC/W2C phase ratio from Mg concentration has been found in the final products. Phase pure WC was prepared with more than 10 mol Mg, and a small amount of ammonium carbonate (or urea) was blended with the WO3+ C mixture. The effects of the combustion conditions on product morphology and composition were evaluated using scanning electron microscopy and x-ray diffraction analysis. The results of the investigation indicate that carbon-containing compounds significantly enhance the combustion synthesis process; leading to higher conversion efficiencies and phase pure WC formation at 1500–1550 °C. The crystalline particles of WC showed a narrow distribution in particle size, with a mean diameter around 200 nm. The results are discussed in the context of gas-phase and solid-phase transport models.
Temperature dependence of mechanical properties in ultrathin Au films with and without passivation
Authors: Gruber Patric A. , Olliges Sven , Arzt Eduard , Spolenak Ralph
Published: August 2008

Temperature and film thickness are expected to have an influence on the mechanical properties of thin films. However, mechanical testing of ultrathin metallic films at elevated temperatures is difficult, and few experiments have been conducted to date. Here, we present a systematic study of the mechanical properties of 80–500-nm-thick polycrystalline Au films with and without SiNx passivation layers in the temperature range from 123 to 473 K. The films were tested by a novel synchrotron-based tensile testing technique. Pure Au films showed strong temperature dependence above 373 K, which may be explained by diffusional creep. In contrast, passivated samples appeared to deform by thermally activated dislocation glide. The observed activation energies for both mechanisms are considerably lower than those for the bulk material, indicating that concomitant stress relaxation mechanisms are more pronounced in the thin film geometry.
Indentation fracture of low-dielectric constant films: Part II. Indentation fracture mechanics model
Authors: Morris Dylan J. , Cook Robert F.
Published: August 2008

Part I [D.J. Morris and R.F. Cook,J. Mater. Res.23,2429 (2008)] of this two-part work explored the instrumented indentation and fracture phenomena of compliant, low-dielectric constant (low-κ) films on silicon substrates. The effect of film thickness and probe acuity on the fracture response, as well as the apparent connection of this response to the perceived elastic modulus, were demonstrated. These results motivate the creation of a fracture model that incorporates all of these variables here in Part II. Indentation wedging is identified as the mechanism that drives radial fracture, and a correction is introduced that adjusts the wedging strength of the probe for the attenuating influence of the relatively stiff substrate. An estimate of the film fracture toughness can be made if there is an independent measurement of the film stress; if not, a critical film thickness for channel-cracking under the influence of film stress may be estimated.
Amorphous to anatase transformation in atomic layer deposited titania thin films induced by hydrothermal treatment at 120 °C
Authors: Zhang Zhaoming , Triani Gerry , Fan Liang-Jen
Published: August 2008

Hydrothermal treatment has been applied successfully to convert amorphous titania films to crystalline anatase at 120 °C, a temperature compatible with most polymeric substrates. The amorphous films were deposited at 80 °C using atomic layer deposition (ALD). The crystallinity of the films was monitored by x-ray absorption near edge structure (XANES), and the film composition was determined by x-ray photoelectron spectroscopy (XPS). The effect of precursor chemistry and substrate material was investigated. It was found that titania films produced from Ti isopropoxide are easier to crystallize than those from Ti tetrachloride as the Ti precursor. The amorphous to crystalline transformation can be achieved more readily with films deposited on Si than polycarbonate substrates. The effect of a “seed” layer on the amorphous to crystalline transformation was also studied. Preformed anatase crystallites between the Si substrate and the amorphous film were shown to accelerate the crystallization process. The possible mechanisms responsible for the phase transformation are discussed.
Morphology, mechanical, and thermal properties of aramid/layered silicate nanocomposite materials
Authors: Zulfiqar Sonia , Sarwar Muhammad Ilyas , Lieberwirth Ingo , Ahmad Zahoor
Published: August 2008

Aramid-based nanocomposites were prepared by solution intercalation techniques using p-aminobenzoic acid-modified montmorillonite. Polyamide was synthesized by reacting 4,4′-oxydianiline with isophthaloyl chloride in dimethyl acetamide. To create chemical interactions between the two phases for better dispersion of organoclay, aramid chains were selectively amine end-capped. The influence of organically modified clay on the morphology was investigated by x-ray diffraction (XRD), polarized optical microscopy (POM), and transmission electron microscopy (TEM). Mechanical, thermal, and water uptake measurements were carried out to further verify other physical properties of the nanocomposites. Tensile strength, modulus, elongation at break, and toughness were improved relative to pure polymer with the addition of 6 wt% organoclay. Thermal-decomposition temperatures of the nanocomposites were in the range 300–450 °C. Water uptake of neat aramid film was rather high (5.7%) and decreased with augmenting organoclay. DSC exhibited increase in the glass transition temperature (118 °C) up to addition of 16 wt% of organoclay.
Investigation of nitrogen-doped TiO2 thin films grown by reactive pulsed laser deposition
Authors: Sauthier G. , György E. , Figueras A.
Published: August 2008

Nitrogen-doped titanium dioxide (TiO2) thin films were synthesized on glass substrates by reactive pulsed laser deposition technique (PLD). A frequency quadrupled Nd:YAG (λ = 266 nm, τFWHM ≅ 5 ns, ν = 10 Hz) laser source was used for the irradiations of TiO2 targets. The experiments were performed in controlled reactive atmosphere consisting of mixtures of oxygen and nitrogen gases. We demonstrated that there exists the possibility for the accurate control of the nitrogen incorporation through the growth parameters, i.e., the nitrogen partial pressure in the reaction enclosure. The substitutional nitrogen doping of the anatase phase TiO2 thin films allows for the continuous shift of the optical absorption edge towards the visible spectral range. When a threshold value of the nitrogen dopant level is surpassed the crystallization structure of the TiO2 anatase phase thin films changes, and the onset of a stable titanium-oxinitride phase formation takes place.
Nanoindentation hardness, Young’s modulus, and creep behavior of organic–inorganic silica-based sol-gel thin films on copper
Authors: Latella Bruno A. , Gan Bee K. , Barbé Christophe J. , Cassidy David J.
Published: August 2008

In this study, the mechanical properties and creep behavior of hybrid sol-gel silica-based coatings on copper substrates were investigated. Sol-gel processing was used to synthesize the organically modified silanes using mixtures of tetraethoxysilane and vinyltrimethoxysilane or glycidoxypropyltrimethoxysilane precursors. The mechanical and creep properties of the coatings were assessed using nanoindentation. The link between film structure and creep behavior from nanoindentation experiments was examined, and simple mechanical models were used to extract Young’s modulus and viscosity from fits to creep data. It is shown that the creep response of the coatings was influenced dramatically by the chain length and amount of organic substituent.
Characteristics of bacterial and viral contamination of urban waters: a case study in Xi'an, China
Authors: Zhang C. M. , Wang X. C. , Liu Y. J. , Xue X. P.
Published: August 2008

In order to gain knowledge on the presences of bacteria and viruses in urban waters, the authors started a long-term study on the microbiological quality of urban lakes and rivers in Xi'an, China. In the current study, enteroviruses were chosen as typical viruses and RT-nested PCR was conducted for their detection. Universal primers were designed for simultaneous detection of poliovirus, coxsackievirus, and enterovirus 71 which are the most frequently encountered enteroviruses in China. The RT-nested PCR protocol established in this study showed high sensitivity and specificity. The detection limit was equivalent to 0.038 CCID50 per litre by applying a modified adsorption-elution concentration method. No cross-reactivity was observed using the genome of pathogenic bacteria as of PCR template. The occurrence of enteroviruses was compared with fecal coliform count in a 6-month period from July to December 2006 for the urban waters. As a result, it was noticed that the presence of enteroviruses might not relate to the fecal coliform count so much. Statistical analysis also indicated that there was no significant correlation between the presence of enteroviruses and that of total bacteria, total coliform, and fecal coliform.
Identifying common traits among Australian irrigators using cluster analysis
Authors: Kuehne G. , Bjornlund H. , Cheers B.
Published: August 2008

In Australia there is a growing awareness that the over-allocation of water entitlements to irrigators needs to be reduced so that environmental flow allocations can be increased. This means that some water will need to be acquired from irrigators and returned to the environment. Most current water reform policies assume that irrigators are solely motivated by profit and will be willing sellers of water, but this might be an untenable approach. Authorities will need to consider new ways of encouraging the participation of irrigators in water reform. The main aim of this research was to identify the non-commercial influences acting on irrigators' behaviour, especially the influence of the values that they hold toward family, land, water, community and lifestyle. The study also aimed to investigate whether it is possible to group irrigators according to these values and then use the groupings to describe how these might affect their willingness to participate in environmental reforms. We clustered the irrigators into three groups with differing orientations; (i) Investors [25%]—profit oriented, (ii) Lifestylers [25%]–lifestyle oriented, (iii) Providers [50%]–family-succession oriented. This research indicates that when designing policy instruments to acquire water for environmental purposes policy-makers should pay more attention to the factors influencing irrigators' decision making, especially non-commercial factors.
Treatment of a landfill leachate containing compounds of pharmaceutical origin
Authors: Matošić M. , Terzić S. , Korajlija Jakopović H. , Mijatović I. , Ahel M.
Published: August 2008

Paper reports the results of landfill leachate treatment with membrane bioreactor, nanofiltration and ozonation. Investigated leachate encompasses a number of specific compounds of pharmaceutical origin, including a suite of by-products deriving from the production of vitamin C and propyphenazone. Low biodegradability was observed in MBR (16%) for propyphenazone, while the removal of intermediates from the vitamin C-synthesis was moderate, reaching 30% for diacetone sorbose (DAS) and 69% for diacetone alpha-keto-gulonic acid (DAG). Ozonation almost completely removed propyphenazone but failed to significantly oxidise intermediates from the vitamin C-synthesis. Nanofiltration of the leachate succeeded to remove 99% of DAG and 79% of propyphenazone which made it the most efficient among techniques used.
Enhanced Inhibitory Effect of Ultra-Fine Granules of Red Ginseng on LPS-induced Cytokine Expression in the Monocyte-Derived Macrophage THP-1 Cells
Authors: Lee Hyoung-Cheol , Vinodhkumar Radhakrishnan , Yoon Jang W. , Park Seong-Kyu , Lee Chang-Won , Kim Hong-Yeoul
Published: August 2008

Red ginseng is one of the most popular traditional medicines in Korea because its soluble hot-water extract is known to be very effective on enhancing immunity as well as inhibiting inflammation. Recently, we developed a new technique, called the HACgearshift system, which can pulverize red ginseng into the ultra-fine granules ranging from 0.2 to 7.0 μm in size. In this study, the soluble hot-water extract of those ultra-fine granules of red ginseng (URG) was investigated and compared to that of the normal-sized granules of red ginseng (RG). The high pressure liquid chromatographic analyses of the soluble hot-water extracts of both URG and RG revealed that URG had about 2-fold higher amounts of the ginsenosides, the biologically active components in red ginseng, than RG did. Using quantitative RT-PCR, cytokine profiling against the Escherichia coli lipopolysaccharide (LPS) in the monocyte-derived macrophage THP-1 cells demonstrated that the URG-treated cells showed a significant reduction in cytokine expression than the RG-treated ones. Transcription expression of the LPS-induced cytokines such as TNF-α, IL-1β, IL-6, IL-8, IL-10, and TGF-β was significantly inhibited by URG compared to RG. These results suggest that some biologically active and soluble components in red ginseng can be more effectively extracted from URG than RG by standard hot-water extraction.
Extraction and Separation of Volatile and Fixed Oils from Berries of Laurus nobilis L. by Supercritical CO2
Authors: Marzouki Hanen , Piras Alessandra , Marongiu Bruno , Rosa Antonella , Dessì M. Assunta
Published: August 2008

Isolation of volatile and fixed oils from dried berries of Laurus nobilis L. from Tunisia have been obtained by supercritical fractioned extraction with carbon dioxide. Extraction experiments were carried out at a temperature of 40 °C and pressures of 90 and 250 bar. The extraction step performed at 90 bar produced a volatile fraction mainly composed of (E)-β-ocimene (20.9%), 1,8-cineole (8.8%), α-pinene (8.0%), β-longipinene (7.1%), linalool acetate (4.5%), cadinene (4.7%), β-pinene (4.2%), α-terpinyl acetate (3.8%) and α-bulnesene (3.5%). The oil yield in this step of the process was 0.9 % by weight charged. The last extraction step at 250 bar produced an odorless liquid fraction, in which a very small percentage of fragrance compounds was found, whereas triacylglycerols were dominant. The yield of this step was 15.0 % by weight. The most represented fatty acids of the whole berry fixed oil were 12:0 (27.6%), 18:1 n-9 (27.1%), 18:2 n-6 (21.4%), and 16:0 (17,1%), with the 18:1 n-9 and 18:2 n-6 unsaturated fatty acids in particular averaging 329 μg/mg of oil.
Oligomerization of Indole Derivatives with Incorporation of Thiols
Authors: Mutulis Felikss , Gogoll Adolf , Mutule Ilze , Yahorava Sviatlana , Yahorau Aleh , Liepinsh Edvards , Wikberg Jarl
Published: August 2008

Two molecules of indole derivative, e.g. indole-5-carboxylic acid, reacted with one molecule of thiol, e.g. 1,2-ethanedithiol, in the presence of trifluoroacetic acid to yield adducts such as 3-[2-(2-amino-5-carboxyphenyl)-1-(2-mercaptoethylthio)ethyl]-1Hindole-5-carboxylic acid. Parallel formation of dimers, such as 2,3-dihydro-1H,1'H-2,3'-biindole-5,5'-dicarboxylic acid and trimers, such as 3,3'-[2-(2-amino-5-carboxyphenyl) ethane-1,1-diyl]bis(1H-indole-5-carboxylic acid) of the indole derivatives was also observed. Reaction of a mixture of indole and indole-5-carboxylic acid with 2-phenylethanethiol proceeded in a regioselective way, affording 3-[2-(2-aminophenyl)-1-(phenethylthio)ethyl]-1H-indole-5-carboxylic acid. An additional product of this reaction was 3-[2-(2-aminophenyl)-1-(phenethylthio)ethyl]-2,3-dihydro-1H,1'H-2,3'-biindole-5'-carboxylic acid, which upon standing in DMSO-d6 solution gave 3-[2-(2-aminophenyl)-1-(phenethylthio)ethyl]-1H,1'H-2,3'-biindole-5'-carboxylic acid. Structures of all compounds were elucidated by NMR, and a mechanism for their formation was suggested.
Efficacy of the Oral Fluorouracil Pro-drug Capecitabine in Cancer Treatment: a Review
Authors: Koukourakis Georgios V. , Kouloulias Vassilios , Koukourakis Michael J. , Zacharias Georgios A. , Zabatis Haralabos , Kouvaris John
Published: August 2008

Capecitabine (Xeloda®) was developed as a pro-drug of fluorouracil (FU), with the aim of improving tolerability and intratumor drug concentrations through its tumorspecific conversion to the active drug. The purpose of this paper is to review the available information on capecitabine, focusing on its clinical effectiveness against various carcinomas. Identification of all eligible English trails was made by searching the PubMed and Cochrane databases from 1980 to 2007. Search terms included capecitabine, Xeloda and cancer treatment. Nowadays, FDA has approved the use of capecitabine as a first line therapy in patients with metastatic colorectal cancer when single-agent fluoropyrimidine is preferred. The drug is also approved for use as a single agent in metastatic breast cancer patients who are resistant to both anthracycline and paclitaxel-based regimens or when further anthracycline treatment is contraindicated. It is also approved in combination with docetaxel after failure of prior anthracycline-based chemotherapy. In patients with prostate, pancreatic, renal cell and ovarian carcinomas, capecitabine as a single-agent or in combination with other drugs has also shown benefits. Improved tolerability and comparable efficacy, compared with the intravenous FU/LV combination, in addition to its oral administration, make capecitabine an attractive option for the treatment of several types of carcinomas.
A New 3-Benzylchroman Derivative from Sappan Lignum (Caesalpinia sappan)
Authors: Fu Lin-chun , Huang Xin-an , Lai Zhen-yuan , Hu Ying-jie , Liu Hong-jiao , Cai Xiao-ling
Published: August 2008

3'-Deoxy-4-O-methylepisappanol, a new 3-benzylchroman derivative, was isolated from Sappan Lignum, together with thirteen known chemical compounds identified as protosappanin A, sappanchalcone, sappanone B, palmitic acid, (+)-(8S,8'S)-bisdihydrosiringenin, brazilein, 3-deoxysappanchalcone, (+)-lyoniresinol, 3-deoxysappanone B, protosappanin B, isoprotosappanin B, 3'-O-methylbrazilin and brazilin, respectively. Among these known compounds, this is the first time that (+)-(8S,8'S)-bisdihydrosiringenin was obtained from the family Caesalpiniaceae.
Wireless and Powerless Sensing Node System Developed for Monitoring Motors
Authors: Lee Dasheng
Published: August 2008

Reliability and maintainability of tooling systems can be improved through condition monitoring of motors. However, it is difficult to deploy sensor nodes due to the harsh environment of industrial plants. Sensor cables are easily damaged, which renders the monitoring system deployed to assure the machine’s reliability itself unreliable. A wireless and powerless sensing node integrated with a MEMS (Micro Electro-Mechanical System) sensor, a signal processor, a communication module, and a self-powered generator was developed in this study for implementation of an easily mounted network sensor for monitoring motors. A specially designed communication module transmits a sequence of electromagnetic (EM) pulses in response to the sensor signals. The EM pulses can penetrate through the machine’s metal case and delivers signals from the sensor inside the motor to the external data acquisition center. By using induction power, which is generated by the motor’s shaft rotation, the sensor node is self-sustaining; therefore, no power line is required. A monitoring system, equipped with novel sensing nodes, was constructed to test its performance. The test results illustrate that, the novel sensing node developed in this study can effectively enhance the reliability of the motor monitoring system and it is expected to be a valuable technology, which will be available to the plant for implementation in a reliable motor management program.
Silicon Wafer-Based Platinum Microelectrode Array Biosensor for Near Real-Time Measurement of Glutamate in Vivo
Authors: Wassum Kate M. , Tolosa Vanessa M. , Wang Jianjun , Walker Eric , Monbouquette Harold G. , Maidment Nigel T.
Published: August 2008

Using Micro-Electro-Mechanical-Systems (MEMS) technologies, we have developed silicon wafer-based platinum microelectrode arrays (MEAs) modified with glutamate oxidase (GluOx) for electroenzymatic detection of glutamate in vivo. These MEAs were designed to have optimal spatial resolution for in vivo recordings. Selective detection of glutamate in the presence of the electroactive interferents, dopamine and ascorbic acid, was attained by deposition of polypyrrole and Nafion. The sensors responded to glutamate with a limit of detection under 1μM and a sub-1-second response time in solution. In addition to extensive in vitro characterization, the utility of these MEA glutamate biosensors was also established in vivo. In the anesthetized rat, these MEA glutamate biosensors were used for detection of cortically-evoked glutamate release in the ventral striatum. The MEA biosensors also were applied to the detection of stress-induced glutamate release in the dorsal striatum of the freely-moving rat.