bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Chelating Ligands on Arsenic Uptake by Hydroponically Grown Rice Seedlings (Oryza sativa L.): A Preliminary Study
Authors: Rahman Mohammad Azizur , Hasegawa Hiroshi , Ueda Kazumasa , Maki Teruya , Rahman M. Mahfuzur
Published: June 2008

Ferric (oxyhydro‐)oxides (FeOx) precipitate in the rhizosphere at neutral or alkaline pH and are adsorbed on the plant root surfaces. Consequently, the higher binding affinity of arsenate to FeOx and the low iron phytoavailability of the precipitated FeOx make the phytoremediation of arsenic difficult. In the present study, the influence of chelating ligands on arsenic and iron uptake by hydroponically grown rice seedlings (Oryza sativa L.) was investigated. When chelating ligands were not treated to the growth medium, about 63 and 71% of the total arsenic and iron were distributed in the root extract (outer root surfaces) of rice, respectively. On the other hand, ethylenediaminetetraacetic acid (EDTA), ethylenediaminedisuccinic acid (EDDS) and hydroxyiminodisuccinic acid (HIDS) desorbed a significant amount of arsenic from FeOx of the outer root surfaces. Therefore, the uptake of arsenic and iron into the roots and their subsequent translocation to the shoots of the rice seedlings increased significantly. The order of increasing arsenic uptake by chelating ligands was HIDS > EDTA > EDDS. Methylglycinediacetic acid (MGDA) and iminodisuccinic acid (IDS) might not be effective in arsenic solubilization from FeOx. The results suggest that EDDS and HIDS would be a good and environmentally safe choice to accelerate arsenic phytoavailability in the phytoremediation process because of their biodegradability and would be a competent alternative to the widely used non‐biodegradable and environmentally persistent EDTA.
Developing a Green Process in a C9 Aromatic Resin Manufacturing Plant: Online Recycling of Calcium Fluoride Sludge
Authors: Huang Wu‐Jang , Lee Wen‐Ching
Published: June 2008

The calcium fluoride sludge generated from the termination process in a C9+ resin manufacturing plant in Taiwan usually contains high contents of reacted and unreacted monomers. Normally CaF2 sludge is treated by pyrolysis or incineration prior to being landfilled. This paper presents a plan outlining a method to develop a green process through reduction of waste by online recycling of CaF2 sludge. The ordinary CaF2 sludge is collected and activated by fresh lime for recycling and using as a terminator, as with 100% fresh lime. The results indicate that after activating CaF2 sludge with 10% fresh lime, the generated resin contains an unusual odor. However, this problem can be addressed by adding 20% fresh lime for activation. From an economic viewpoint, this method would result in a 40% reduction both in terms of the treatment cost and in the amount of CaF2 sludge generated.
Application of a Newly Synthesized Calixarene in Metal Ions Extraction
Authors: Hamid Shafida Abd. , Tarmizi Amirah Amalina Ahmad , Mohamad Ali Abdussalam Salhin , Saad Bahruddin
Published: June 2008

A new ligand, 25,27‐bis (3‐(4′‐biphenyl‐4‐hydroxy carboxylic acid) propoxy)‐26,28‐dihydroxy‐5,11,17‐tetra(tert‐butyl)calix[4]arene (CBiPh), a derivative of p‐tert‐butylcalix[4]arene (Cax) that was functionalized at the lower rim with biphenyl carboxylic acid has been synthesized. The compound was characterized by using NMR, FT‐IR, and elemental analysis. The 1H and 13C NMR studies indicate that this new macrocycle (CBiPh) preferably adopts a cone structure. Sorbent materials prepared by immobilizing the ligands into silica sol–gel matrix (referred to as calixarene immobilized with sorbent (Cax‐SG) and CBiPh immobilized with sorbent (CBiPh‐SG)) were studied for their competitive sorption characteristic of a mixture of twelve metal ions (Mg2+, Li+, Cd2+, Co2+, Pb2+, Ca2+, Ba2+, Rb+, Ag+, Cs+, Sr2+, and Hg2+). Under the adopted conditions, both sorbents exhibited highest selectivity toward Ag+ (70% for Cax‐SG and 85% CBiPh‐SG), followed by Hg2+ (60% for Cax‐SG and 65% CBiPh‐SG) while the other metal ions were negligibly extracted (< 20%).
Simultaneous Removal of NOx and SO2: A Promising Ag(II)/Ag(I) Based Mediated Electrochemical Oxidation System
Authors: Raju T. , Chung Sang Joon , Pillai K. Chandrasekara , Moon Il‐Shik
Published: June 2008

The present study is a first attempt towards utilizing a Ag(II)/Ag(I) based mediated electrochemical oxidation (MEO) system for the simultaneous clean‐up of NOx and SO2 gases in simulated flue gas‐air mixtures on a laboratory‐scale scrubber column integrated with an electrochemical reactor, and to rationalize the efficient application of the MEO process for flue gas abatement and pollution control. Experiments were carried out with individual gas components followed with the mixture, and the effect of input NO and input SO2 concentrations was examined on the NOx and SO2 removal efficiencies at 20°C. Complete oxidation of NO to NO2 with 100% NO removal efficiency and 80% NOx removal efficiency was achieved along with 100% SO2 removal efficiency, highlighting the potentially far greater efficiency of the Ag(II)/Ag(I) based MEO system in functionality and selectivity. Significant research work in this direction can be anticipated in the near future.
Efficient copackaging and cotransport yields postsynaptic colocalization of neuromodulators associated with synaptic plasticity
Authors: Lochner J.E. , Spangler E. , Chavarha M. , Jacobs C. , McAllister K. , Schuttner L.C. , Scalettar B.A.
Published: June 2008

Recent data suggest that tissue plasminogen activator (tPA) influences long‐term plasticity at hippocampal synapses by converting plasminogen into plasmin, which then generates mature brain‐derived neurotrophic factor (mBDNF) from its precursor, proBDNF. Motivated by this hypothesis, we used fluorescent chimeras, expressed in hippocampal neurons, to elucidate (1) mechanisms underlying plasminogen secretion from hippocampal neurons, (2) if tPA, plasminogen, and proBDNF are copackaged and cotransported in hippocampal neurons, especially within dendritic spines, and (3) mechanisms mediating the transport of these neuromodulators to sites of release. We find that plasminogen chimeras traffic through the regulated secretory pathway of hippocampal neurons in dense‐core granules (DCGs) and that tPA, plasminogen, and proBDNF chimeras are extensively copackaged in DCGs throughout hippocampal neurons. We also find that 80% of spines that contain DCGs contain chimeras of these neuromodulators in the same DCG. Finally, we demonstrate, for the first time, that neuromodulators undergo cotransport along dendrites in rapidly mobile DCGs, indicating that neuromodulators can be efficiently recruited into active spines. These results support the hypothesis that tPA mediates synaptic activation of BDNF by demonstrating that tPA, plasminogen, and proBDNF colocalize in DCGs in spines, where these neuromodulators can undergo activity‐dependent release and then interact and/or mediate changes that influence synaptic efficacy. The results also raise the possibility that frequency‐dependent changes in extents of neuromodulator release from DCGs influence the direction of plasticity at hippocampal synapses by altering the relative proportions of two proteins, mBDNF and proBDNF, that exert opposing effects on synaptic efficacy. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008.
Libraries of Bidentate Phosphorus Ligands; Synthesis Strategies and Application in Catalysis (Eur. J. Inorg. Chem. 19/2008)
Authors: Goudriaan P. Elsbeth , van Leeuwen Piet W. N. M. , Birkholz Mandy‐Nicole , Reek Joost N. H.
Published: June 2008

The cover picture shows structures that represent three different ways of making phosphorus‐based ligand libraries: modular synthesis, solid‐phase synthesis and formation of ligands by assembly of smaller building blocks. These ligand libraries are important for the rapid identification of new catalysts for (asymmetric) conversions. In this Microreview on p. 2939 ff J. N. H. Reek et al. show examples that illustrate these strategies.
Bioactive Nitronaphthalenes from an Endophytic Fungus, Coniothyrium sp., and Their Chemical Synthesis
Authors: Krohn Karsten , Kouam Simeon F. , Cludius‐Brandt Stephan , Draeger Siegfried , Schulz Barbara
Published: June 2008

Four natural nitro metabolites, 1‐hydroxy‐5‐methoxy‐2‐nitronaphthalene (2), 1,5‐dimethoxy‐4‐nitronaphthalene (3), 1‐hydroxy‐5‐methoxy‐2,4‐dinitronaphthalene (4), and 1,5‐dimethoxy‐4,8‐dinitronaphthalene (5), known from chemical synthesis but new as natural products, were isolated together with two known compounds, 1‐hydroxy‐5‐methoxynaphthalene (1) and ergosterol (6) from an endophytic fungus, Coniothyrium sp. The structures of 1–6 were determined by spectroscopic methods including 1D and 2D NMR experiments and by mass spectrometric measurements. The structures of 1–4 were confirmed by chemical synthesis. The nitronaphthols showed considerable antibacterial, antifungal, and antialgal properties.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Broad Functionalization of Deep‐Cavity Cavitands by Directed ortho Metalation (Eur. J. Org. Chem. 19/2008)
Authors: Srinivasan Kannupal , Laughrey Zachary R. , Gibb Bruce C.
Published: June 2008

The cover picture shows a collection of china, pewter cups, mugs, and jugs. For these and other macroscale objects, it is easier to decorate their exterior rather than their interior surface. Not surprisingly, the same asymmetry is seen at the molecular scale; it is generally easier to decorate/functionalize a convex than a concave surface. One approach to endo functionalization of deep‐cavity cavitands is directed ortho metalation (DoM). In the paper by Srinivasan et al., on p. 3265 ff, it is shown that various electrophiles quench the lithiates formed according to DoM protocols. Reaction control leads to between one and five functional groups being introduced at the endo and exo positions of these hosts.
Simultaneous Determination of 4‐Chlorophenol and Oxalic Acid Using an Expanded Graphite‐Epoxy Composite Electrode
Authors: Manea Florica , Radovan Ciprian , Corb Ioana , Pop Aniela , Burtica Georgeta , Malchev Plamen , Picken Stephen , Schoonman Joop
Published: June 2008

An expanded graphite‐epoxy composite electrode (EG‐Epoxy) was employed for the simultaneous determination of 4‐chlorophenol (4‐CP) and oxalic acid (OA) by using cyclic voltammetry (CV), chronoamperometry (CA), and differential pulse voltammetry (DPV). The results indicated that OA could be determined in the presence of the same concentrations of 4‐CP within the concentration range of 0.1 mM to 0.5 mM with a relative standard deviation (RSD) smaller than 5%. Electrode fouling occurred during CA for 4‐CP concentrations larger than 0.5 mM. The DPV method was used for the simultaneous determination of 4‐CP and OA before and after electrochemical oxidation by chronopotentiometry under galvanostatic conditions (j=0.04 mA cm−2, t=2 h) of a tap water sample spiked with 0.19 mM 4‐CP and 0.1 M Na2SO4.
The semicircular canal system and locomotion: The case of extinct lemuroids and lorisoids
Authors: Walker Alan , Ryan Timothy M. , Silcox Mary T. , Simons Elwyn L. , Spoor Fred
Published: June 2008

Paleontologists reconstruct the locomotor and postural behavior of extinct species by analogy with living forms and biomechanical analyses. In rare cases, behavioral evidence such as footprints can be used to confirm fossil‐based reconstructions for predominantly terrestrial orders of mammals. For instance, the chalicothere prints from Laetoli show that these perissodactyls supported their body weight on the metacarpals, as previously reconstructed.1 Unfortunately, primates are mostly arboreal and rarely leave footprints. The cercopithecid and hominin prints at Laetoli are a rare exception. We have recently shown that the semicircular canal system can be used to test and augment locomotor reconstructions based on postcranial material or to provide first estimations of locomotor behavior for taxa not known from the postcranium. Using a sample of modern primates, we have been able to demonstrate that the radii of curvature of the semicircular canals are significantly correlated with both body mass and agility of locomotion.2 This paper reviews those results and examines the relationship between semicircular canal morphology and other evidence in efforts to reconstruct locomotor behavior in subfossil lemurs from the Holocene of Madagascar and fossil lorisoids from the Miocene of Africa.
Controlled delivery of paclitaxel from stent coatings using novel styrene maleic anhydride copolymer formulations
Authors: Richard Robert , Schwarz Marlene , Chan Ken , Teigen Nikolai , Boden Mark
Published: June 2008

The controlled release of paclitaxel (PTx) from stent coatings comprising an elastomeric polymer blended with a styrene maleic anhydride (SMA) copolymer is described. The coated stents were characterized for morphology by scanning electron microscopy (SEM) and atomic force microscopy (AFM), and for drug release using high‐performance liquid chromatography (HPLC). Differential scanning calorimetry (DSC) was used to measure the extent of interaction between the PTx and polymers in the formulation. Coronary stents were coated with blends of poly(b‐styrene‐b‐isobutylene‐b‐styrene) (SIBS) and SMA containing 7% or 14% maleic anhydride (MA) by weight. SEM examination of the stents showed that the coating did not crack or delaminate either before or after stent expansion. Examination of the coating surface via AFM after elution of the drug indicated that PTx resides primarily in the SMA phase and provided information about the mechanism of PTx release. The addition of SMA altered the release profile of PTx from the base elastomer coatings. In addition, the presence of the SMA enabled tunable release of PTx from the elastomeric stent coatings, while preserving mechanical properties. Thermal analysis reveled no shift in the glass transition temperatures for any of the polymers at all drug loadings studied, indicating that the PTx is not miscible with any component of the polymer blend. An in vivo evaluation indicated that biocompatibility and vascular response results for SMA/SIBS‐coated stents (without PTx) are similar to results for SIBS‐only‐coated and bare stainless steel control stents when implanted in the non‐injured coronary arteries of common swine for 30 and 90 days. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Biological response to micron‐ and nanometer‐sized particles known as potential wear products from artificial hip joints: Part II: Reaction of murine macrophages to corundum particles of different size distributions
Authors: Kranz I. , Gonzalez J. B. , Dörfel I. , Gemeinert M. , Griepentrog M. , Klaffke D. , Knabe C. , Österle W. , Gross U.
Published: June 2008

Macrophages play a pivotal role in tissue reaction and immune response. They recognize, phagocytose particles and generate cytokines to influence local cellular reactions. Friction and wear of implant components usually generates microparticles (MP) in a size range of 1–10 μm and nanoparticles (NP) in the range of 10–1000 nm. To investigate the possible impact of MP or NP on cellular reactions, we exposed murine macrophages (RAW264.7) to corundum MP and NP. The same mass was used in both NP and MP cell culture solutions, i.e. there were more NP than MP per identical volumes of culture solution. After 4, 24, 48, 72, and 96 h aliquots of cell culture supernatants were tested for different cytokines, growth factors and nitric oxide. Macrophages were stained with MGG (May‐Grünwald Giemsa), counted and morphologically characterized by scanning electron microscopy and transmission electron microscopy. Particles were attached to cell surfaces and phagocytosed within cells. Cells stimulated with particles or lipopolysaccharides for positive controls showed surface modifications indicating enhanced function. Although only marginal differences between negative controls and particle‐stimulated cells were observed in respect to cytokine production, exposure to corundum particles led to a decrease in the number of vital macrophages and to an increase in the number of giant cells. Corundum NP formed micron‐sized aggregates in the cell culture medium and led to the production of more giant cells than MP. Sodiumdodecylsulfate polyacrylamide gel electrophoresis of the cell culture medium with particles proved the adsorption of proteins to particles. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Discrete calcium phosphate nanocrystalline deposition enhances osteoconduction on titanium‐based implant surfaces
Authors: Mendes Vanessa C. , Moineddin Rahim , Davies John E.
Published: June 2008

We sought to assess the ability of nanotopographically complex titanium surfaces to accelerate osteoconduction. For this, 130 miniature bone ingrowth chambers (called “T plants”), fabricated from either commercially pure titanium (cpTi) or titanium alloy (Ti6Al4V or Ti64), with microtopographically complex surfaces were used in the study, of which 50 were further modified by the discrete crystalline deposition (DCD) of calcium phosphate (CAP) nanoparticles that superimposed a nanotopographic complexity on each implant surface. Thus, four experimental groups were generated (cpTi, cpTi‐DCD, Ti64, and Ti64‐DCD), and the Tplants were implanted bilaterally in the femora of Wistar rats for 9 days. After harvesting, the femora were trimmed, and multiple‐mounted samples were embedded in PMMA. The blocks produced were ground and block faces observed by back‐scattering electron imaging (BSEI) at different planes through the chambers. Osteoconduction was assessed, as a function of bone‐implant contact, on a total of 1087 BSEI micrographs and submitted to rigorous statistical analyses. Our results showed both the important effects of anatomic location on bone ingrowth and the significant increase in osteoconduction (p < 0.001) as a function of the enhanced surface nanotopography obtained by the CAP nanocrystals. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Gelatin nanofibrous membrane fabricated by electrospinning of aqueous gelatin solution for guided tissue regeneration
Authors: Zhang Shen , Huang Yaqin , Yang Xiaoping , Mei Fang , Ma Qi , Chen Guoqiang , Ryu Seungkon , Deng Xuliang
Published: June 2008

The electrospinning of gelatin aqueous solution was successfully carried out by elevating the spinning temperature. The effects of spinning temperature and solution concentration were investigated on the morphology of gelatin nanofibers in the current study. To improve the stability and mechanical properties in moist state, the gelatin nanofibrous membrane was chemically crosslinked by 1‐ethyl‐3‐dimethyl‐aminopropyl carbodiimide hydrochloride and N‐hydroxyl succinimide. The concentration of crosslinker was optimized by measuring the swelling degree and weight loss. Nanofibrous structure of the membrane was retained after lyophilization, although the fibers were curled and conglutinated. Tensile test revealed that the hydrated membrane becomes pliable and provides predetermined mechanical properties. Periodontal ligament cells cultured on the membrane in vitro exhibited good cell attachment, growth, and proliferation. Gelatin nanofibrous membrane can be one of promising biomaterials for the regeneration of damaged periodontal tissues. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Cytotoxic action mode of a novel porphyrin derivative isolated from harmful red tide dinoflagellate Heterocapsa circularisquama
Authors: Kim Daekyung , Miyazaki Yousuke , Nakashima Takuji , Iwashita Takashi , Fujita Tsuyoshi , Yamaguchi Kenichi , Choi Kwang‐Sik , Oda Tatsuya
Published: June 2008

Heterocapsa circularisquama is known to cause lethal effect on bivalves, but toxic effect on fish has not been reported yet. Recently, we have found that H. circularisquama has potent light‐dependent hemolytic toxins. Based on the chemical structural analysis, one of the hemolytic toxins named H2‐a was found to be a novel porphyrin derivative with similar structure to pyropheophorbide a methyl ester (PME), a well‐known photoactive hemolytic agent (Miyazaki et al., Aquatic Toxicol. 2005;73:382‐‐393). To clarify the cytotoxic action mode of H2‐a, we examined the effects of H2‐a on HeLa cells in comparison with PME. The cytotoxicities of both reagents were strictly light dependent, and no significant cytotoxic effects including cellular morphological changes were induced without light illumination. The dose response curves revealed that H2‐a showed stronger cytotoxicity to HeLa cells than PME. Fluorescence microscopic observation suggested that H2‐a tends to accumulate in the plasma membrane, whereas PME seems to distribute entire cytoplasm. Although PME induced typical apoptotic nuclear morphological changes and DNA fragmentation in HeLa cells, no such apoptosis‐inducing ability of H2‐a was observed. Among the radical scavengers, histidine significantly inhibited the cytotoxic activity of H2‐a, suggesting the involvement of singlet oxygen in the cytotoxicity. These results suggest that the cytotoxic mechanism of H2‐a is necrotic rather than apoptosis differing from PME, even though these are structurally quite similar to each other. The relatively high affinity of H2‐a to the plasma membrane might result in the potent and quick cytotoxicity without induction of apoptotic signal transduction. © 2008 Wiley Periodicals, Inc. J Biochem Mol Toxicol 22:158–165, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20216
Channa punctata brain metallothionein is a potent scavenger of superoxide radicals and prevents hydroxyl radical‐induced in vitro DNA damage
Authors: Atif Fahim , Kaur Manpreet , Ansari Rizwan A. , Raisuddin Sheikh
Published: June 2008

Mammalian brain metallothioneins (MTs) have been shown to scavenge free radicals. However, a similar role for fish brain MT has not been established yet. Previously, we have reported that MT from the liver of a freshwater fish, Channa punctata Bloch, had free‐radical‐scavenging activity in vitro. In this study, we report on the induction of MT in brain and other tissues of C. punctata treated with a low concentration of zinc chloride. We partially purified MT (Zn‐MT)‐rich fraction from the brain and studied its free‐radical‐scavenging and DNA damage attenuating effects. Zinc exposure showed significant MT induction in brain, gill, kidney, and liver. C. punctata brain MT efficiently scavenged superoxide radicals and also attenuated hydroxyl radical‐mediated DNA damage. These findings suggest that fish brain MT has a free‐radical‐scavenging activity, and its expression may be regulated in response to stress and chemical exposure. C. punctata has been identified as a potent biomarker fish species. It is suggested that this fish species may be a good model for the study of MTs with regard to their regulatory and biomarker functions. © 2008 Wiley Periodicals, Inc. J Biochem Mol Toxicol 22:202–208, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20230
Possible impacts of anthropogenic and natural aerosols on Australian climate: a review
Authors: Rotstayn Leon D. , Keywood Melita D. , Forgan Bruce W. , Gabric Albert J. , Galbally Ian E. , Gras John L. , Luhar Ashok K. , McTainsh Grant H. , Mitchell Ross M. , Young Stuart A.
Published: June 2008

A review is presented of the aerosol–climate interaction with specific focus on the Australian region. The uncertainties associated with this interaction are much larger than those associated with greenhouse gases or other forcing agents, and are currently a major obstacle in climate‐change research. However, new research suggests that aerosol effects are of comparable importance to greenhouse gases as a driver of recent climate trends in the Southern Hemisphere, including Australia. A significant new result from climate modelling is that anthropogenic aerosol over Asia affects meridional temperature gradients and atmospheric circulation, and may have caused an increase in rainfall over north‐western Australia. Global ocean circulation provides another mechanism whereby aerosol changes in the Northern Hemisphere can affect climate in the Southern Hemisphere, suggesting an urgent need for further targeted studies using coupled ocean‐atmosphere global climate models. To better model climate variability and climate change in the Australian region, more research is needed into the sources of aerosol and their precursors, their atmospheric distributions and transformations, and how to incorporate these processes robustly in global climate models (GCMs). The following priorities are suggested for further research in Australia linking aerosol observations and modelling: natural aerosol over the Southern Ocean, tropical biomass‐burning aerosol in Indonesia and Australia, secondary organic aerosol (SOA) from volatile organic compounds (VOCs), wind‐blown dust and modulation of rainfall by anthropogenic aerosol. Copyright © 2008 Royal Meteorological Society
An assessment of relationships between the Australian subtropical ridge, rainfall variability, and high‐latitude circulation patterns
Authors: Williams Allyson A. J. , Stone Roger C.
Published: June 2008

The monthly anomaly of the latitude of the subtropical ridge over eastern Australia (L) is a major regulator of synoptic‐scale influences on Australia's climate. Three datasets have been used to calculate L: observed Australia coastal mean sea level pressure (MSLP), Hadley and NCEP Reanalysis datasets. The choice of datasets used in this study appears to strongly influence results. Changes in the Southern Hemisphere Hadley cell and meridional circulation changes are associated with changes in L and it is shown that (1) L has statistically and physically significant relationships with seasonal rainfall in Australia; (2) the Antarctic Oscillation Index (AOI) has statistically significant relationships with Australian seasonal rainfall; and (3) L and Southern Annular Mode (SAM) are significantly related. Longer‐term latitudinal shifts in L are also discussed. Copyright © 2008 Royal Meteorological Society
Simple sample transfer technique by internally expanded desorptive flow for needle trap devices
Authors: Eom In‐Yong , Pawliszyn Janusz
Published: June 2008

Needle trap devices (NTDs) are improving in simplicity and usefulness for sampling volatile organic compounds (VOCs) since their first introduction in early 2000s. Three different sample transfer methods have been reported for NTDs to date. All methods use thermal desorption and simultaneously provide desorptive flow to transfer desorbed VOCs into a GC separation column. For NTDs having ‘side holes’, GC carrier gas enters a ‘side hole’ and passes through sorbent particles to carry desorbed VOCs, while for NTD not having a ‘side hole’, clean air as desorptive flow can be provided through a needle head by a air tight syringe to sweep out desorbed VOCs or water vapor has been reported recently to be used as desorptive flow. We report here a new simple sample transfer technique for NTDs, in which no side holes and an external desorptive flow are required. When an NTD enriched by a mixture of benzene, toluene, ethylbenzene, and xylene (BTEX) or n‐alkane mixture (C6–C15) is exposed to the hot zone of GC injector, the expanding air above the packed sorbent transfers the desorbed compounds from the sorbent to the GC column. This internal air expansion results in clean and sharp desorption profiles for BTEX and n‐alkane mixture with no carryover. The effect of desorption temperature, desorption time, and overhead volumes was studied. Decane having vapor pressure of ∼︁1 Torr at 20°C showed ∼︁1% carryover at the moderate thermal desorption condition (0.5 min at 250°C).
The use of an improved atmospheric correction algorithm for removing atmospheric effects from remotely sensed images using an atmosphere–surface simulation and meteorological data
Authors: Hadjimitsis D. G. , Clayton C. R. I.
Published: June 2008

Unless effective corrections can be applied, satellite remote sensing data will remain modified by the absorption and scattering effects of the atmosphere through which the electromagnetic radiation must pass, between the Sun, the ground and the sensor. The true reflectance of the land will not be recoverable, and multi‐temporal datasets will not be comparable as a result of the variability of the atmosphere. This article presents a method of removing atmospheric effects from satellite remote sensing images for low‐reflectance areas, such as water, where the atmosphere accounts for the majority of the at‐satellite measured radiance in the visible bands. The method uses visibility observations to select a reference image for the area of interest. The reflectance of the dark target is calculated after atmospheric correction from the reference image, and is used in conjunction with Turner and Spencer's atmosphere–surface simulation (Turner and Spencer, 1972) and Forster's method (Forster, 1984), to correct the remainder of the images. The method is applied to three large water treatment reservoirs to the west of London. Copyright © 2008 Royal Meteorological Society
Erratum: Automatic calibration method for phased arrays with arbitrary aperture shape
Authors: Son Seong Ho , Jeon Soon Ik , Hwang Woonbong
Published: June 2008

Originally published Microwave Opt Technol Lett 50:1590–1592, 2008. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2481, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23627
Printed omnidirectional access‐point antenna for 2.4/5‐GHz WLAN operation
Authors: Su Saou‐Wen , Chou Jui‐Hung
Published: June 2008

A new design of the printed omnidirectional antenna for applications in 2.4/5‐GHz dual‐WLAN‐band access points is proposed. The antenna consists of a conventional collinear antenna for 2.4 GHz operation and two U stubs for 5 GHz operation. The two U stubs are located near the points where the maximum currents at about 5.5 GHz occurring on the strips of the collinear antenna and arranged back‐to‐back in the same phase for achieving better antenna gain. Detailed analyses of the U stub on the impedance matching over the 5 GH band is presented. A prototype with good omnidirectional radiation across the 2.4/5‐GHz WLAN bands is demonstrated. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2403–2407, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23629
A 5‐GHz fully integrated low‐power wide‐tuning‐range CMOS LC VCO
Authors: Chen Chang‐Zhi , Fang Hao‐Yu , Lin Yo‐Sheng , Chen Chi‐Chen
Published: June 2008

A 5‐GHz‐band monolithic LC differential voltage‐controlled oscillator (VCO) with low‐power consumption and wide‐tuning‐range was designed and implemented using a standard 0.18‐μm CMOS technology. Low‐power consumption is achieved by maximizing the equivalent parallel resistance of the LC tank, while wide‐tuning‐range is achieved by minimizing the summed parasitic capacitance of the differential inductor and the cross‐coupled PMOS transistors pair. The LC VCO achieves a wide‐tuning‐range of 14.1% (from 4.95 to 5.7 GHz) with a low‐power dissipation of 1.5 mW. The measured phase noise is −111.1 dBc/Hz at 1‐MHz offset. The corresponding figure‐of‐merit (FOM′) of the VCO is −166.8 dBc/Hz, which is comparable with, or even better than, those of the reported state‐of‐the‐art CMOS LC VCOs in 5‐GHz‐band. The chip area is only 630 × 730 μm2excluding the test pads. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2320–2332, 2008; Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.23638
A Sierpinski fractal‐based dual‐mode bandpass filter
Authors: Weng Min‐Hang , Lee Der‐Sun , Yang Ru‐Yuan , Wu Hung‐Wei , Liu Chia‐Ling
Published: June 2008

In this letter, we propose a new microstrip dual mode bandpass filter (BPF) using a 3rd order Sierpinski fractal‐based resonator (SFR). The different order SFRs are generated from the conventional square patch by using an iterative Sierpinski generator method. In this article, a 3rd order SFR is used to design a high performance dual mode BPF due to its miniaturized property. By adding a perturbation element at the corner of the SFR, the dual mode frequency response can be found. A miniature and low insertion dual‐mode BPF centered at 2.4 GHz using the proposed 3rd SFR is designed, fabricated, and characterized to verify the design concept. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2287–2289, 2008; Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.23641
Post‐CMOS compatibly micromachined high‐performance on‐chip air‐core solenoidal inductors
Authors: Gu Lei , Wu Zhengzheng , Li Xinxin
Published: June 2008

This article reports on‐chip micromachined solenoidal inductors with high radio‐frequency (RF) performance. The RF components can be either used in multi‐GHz telecommunication modules with a system in package scheme or monolithically integrated in RFICs with a post‐CMOS integration method. A trench SiO2‐refilling technique is used to shape the silicon cavity for accommodating the embedded inductor, and to mesh the substrate beneath the pads to suppress the substrate‐loss at the pads. Without de‐embedding needed, the tested inductors with 2.5–7 nH inductances achieve 33 to 13.5 peak‐Q factors at 11–3 GHz and self‐resonance frequencies of 18.0–7.5 GHz, respectively. Moreover, the inductors with the trench technique feature a high uniformity in RF‐performances, thereby, showing a promise for practical product applications. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2442–2446, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23646
Active‐inductor‐capacitor tank Colpitts injection‐locked frequency divider
Authors: Jang S.‐L. , Liu C.‐C.
Published: June 2008

This article presents a wide‐locking range injection‐locked frequency divider (ILFD), using a tunable active inductor (TAI), which is used to extend the locking range and to reduce die area. The CMOS ILFD is based on a new Colpitts voltage‐controlled oscillator (CVCO) with TAI‐C tank and was fabricated in the 0.18‐μm 1P6M CMOS technology. The ILFD is performed by adding injection MOSFETs between the differential outputs of the CVCO. At the supply voltage of 1.9 V, the free‐running ILFD tuning range is from 2.25 GHz to 1.26 GHz, whereas the tuning bias of active inductor is tuned from 0.88 V to 1.04 V. At the incident power of 0 dBm, the operation‐locking range is from the incident frequency 1.25–5.85 GHz. The phase noise of the ILFD can track with the injection source. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2376–2379, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23650
A transceiver module for automotive radar sensors using W‐band monolithic microwave‐integrated circuit one‐chip set
Authors: Kang Dong Min , Hong Ju Yeon , Yoon Hyung Sup , Lee Kyung Ho , Choi Ik Guen
Published: June 2008

A 77‐GHz transceiver module has been developed for automotive radar sensors by using an monolithic microwave integrated circuit (MMIC) one‐chip set. An MMIC one‐chip set consists of a transmitter, an eight‐stage low noise amplifier and a mixer. The chip set was fabricated using a 0.15‐μm gate‐length InGaAs/InAlAs/GaAs metamorphic high‐electron mobility transistor (mHEMT) process based on a four‐inch substrate. The transceiver module's total size, including the 38.25 GHz VCO, 76.5 GHz transmitter, 76.5 GHz receiver, 78 GHz LO circuit, IF and BB circuit, and bias circuit, is 80 × 95 × 23 mm3. This MMIC transceiver module is suitable for the 77‐GHz automotive radar sensors and related applications in a W‐band. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2371–2376, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23651
Elastic constant measurement for standard and photosensitive single mode optical fibres
Authors: Antunes P. , Lima Hugo , Monteiro Jorge , André P. S.
Published: June 2008

In this work we determine the elastic constant, the Young modulus, and the strain limit of commercial optical fibers. The fiber rupture limit in standard and Boron codoped photosensitive optical fibers, usually used in FBG‐based sensors, is also quantified. The estimation of such values is extremely relevant, providing useful experimental values to be used in the design and modeling of the sensors. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2467–2469, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23660
A 0.18‐μm 3.1–4.8 GHz CMOS wideband LNA for UWB system
Authors: Jeong Moo I. , Lee Jung N. , Lee Chang S.
Published: June 2008

We have proposed a 3.1–4.8 GHz CMOS wideband low noise amplifier (LNA) for ultra wideband system. The LNA is fabricated with the 0.18‐μm 1P6M standard CMOS process. Measurement of the CMOS LNA was performed using RF probe station. From 3.1 to 4.8 GHz, the wideband LNA exhibits a noise figure of 3.3–3.7 dB, a gain of 12.8–13.9 dB, and an input/output return loss higher then 9.4/7.3 dB. The input IP3 (IIP3) at 4.1 GHz is +1.25 dBm, and consumes 16.5 mW of power. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2368–2371, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23664
Small size low noise amplifier with suppressed noise from gate resistance
Authors: Song Ickhyun , Jhon Hee‐Sauk , Jung Hakchul , Koo Minsuk , Shin Hyungcheol
Published: June 2008

In this article, design and characterization results of a fully integrated 5.8 GHz low noise amplifier (LNA) using 0.13‐μm CMOS technology are presented. Commonly adopted inductive source degeneration for input impedance matching is eliminated to achieve smaller chip area while providing reasonable 50‐Ω matching. Also by adding a capacitor between the gate and the source of the input transistor, a noise source from the gate resistance is partly suppressed. The layout of the designed LNA occupies total area of 0.68 mm2 and the results show forward power gain (S21) of 12.7 dB and noise figure of 3.9 dB while consuming 6.85 mW from 1.2‐V DC supply. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2300–2304, 2008; Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.23702
Mechanical properties of natural fibers/polyamides composites
Authors: de Arcaya Patricia Alvarez , Retegi Aloña , Arbelaiz Aitor , Kenny José María , Mondragon Iñaki
Published: June 2008

The aim of this investigation has been to use high performance thermoplastic matrices such as polyamides instead of the commonly used polyolefins to develop natural fiber composites for substituting glass fibers without renouncing to their mechanical properties. For this purpose, different natural fibers such as flax, jute, pure cellulose, and wood pulps have been melt compounded with different polyamides to analyze the effect of fiber content on mechanical properties. Fibers have not been treated as polyamides are less hydrophobic than polyolefins. Thermal behavior of the different fibers was determined by thermogravimetry to know the boundary for processing at high temperatures, since the melting points of the polyamides are much higher than those of polyolefins and this could lead to a higher degradation of the natural fibers. Rheological parameters were deduced by measuring torque values during the mixing process. Flexural and tensile modulus and strength of composites were analyzed, finding an increase in the mechanical properties compared with the unreinforced matrix that turns natural fibers into a considerable reinforcement offering a wealth of possibilities for industrial applications. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Functionalization of nanoclays with ionic liquids for polypropylene composites
Authors: Ha Jin Uk , Xanthos Marino
Published: June 2008

Cationic nanoclays were treated by ion exchange with various ionic liquids (ILs) containing cations and anions of different structure and/or molecular weight in order to investigate the effects of the IL structure and cation chain length on extent of clay dispersion, intercalation, and thermal stability. The modified clays containing imidazolium‐, pyridinium‐, and phosphonium‐based cations were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and X‐ray diffraction. Although the thermal stability of pure ILs was mostly controlled by the type of the anion present, high temperature thermal stability of the modified clays, at the IL cation loadings achieved in this work, was not significantly dependent on type, structure, or size of the cation. The latter parameters, however, were of significant importance in controlling degree of dispersion of the nanoclays during melt compounding with polypropylene (PP). Basal spacing increased proportionally to the size and type of the intercalated cations and showed little change in the PP composites. Although commercial organoclays were shown to be less thermally stable than IL modified clays, they exhibited larger basal spacing and better dispersion characteristics in the polyolefin matrix; however, they increased to the same extent the thermal stability of the PP matrix as the phosphonium modified clays. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Low profile unsaturated polyester resin–clay nanocomposite properties
Authors: Beheshty Mohammad Hosain , Vafayan Mehdy , Poorabdollah Mehdi
Published: June 2008

Unsaturated polyester (UP)/organically modified clay (OMC) nanocomposites were prepared by multistep simultaneous mixing of UP oligomer chain, styrene (St) monomer, and OMC. X‐ray diffraction, transmission electron microscopy, dynamic mechanical thermal analysis, and scanning electron microscopy data were in support of the formation of a partially intercalated nanocomposite. The glass transition temperatures of the nanocomposites revealed that the crosslinking reaction occurred homogeneously inside and outside of the OMC galleries. Adding 3 wt% OMC improved the flextural and storage modulus of UP by 31.5% and 30.2%, respectively. The Izod impact strength of UP was also improved by 51.7% at 1 wt% of OMC loading. Similar results were obtained for low‐profile UP/St/OMC nanocomposites. Resin shrinkage data measured by inhouse constructed apparatus showed that, at an OMC content of 3 wt%, the UP/St/OMC/low profile additive (LPA) system cannot provide superior volume shrinkage control. But, it is found that the use of nanoscale reinforcement in the UP systems is able to restore flextural and storage moduli loss when using LPAs. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Is the failing heart out of fuel or a worn engine running rich? A study of mitochondria in old spontaneously hypertensive rats
Authors: Jüllig Mia , Hickey Anthony J. R. , Chai Chau C. , Skea Gretchen L. , Middleditch Martin J. , Costa Silvana , Choong Soon Y. , Philips Anthony R. J. , Cooper Garth J. S.
Published: June 2008

Hypertension now affects about 600 million people worldwide and is a leading cause of death in the Western world. The spontaneously hypertensive rat (SHR), provides a useful model to investigate hypertensive heart failure (HF). The SHR model replicates the clinical progression of hypertension in humans, wherein early development of hypertension is followed by a long stable period of compensated cardiac hypertrophy that slowly progresses to HF. Although the hypertensive failing heart generally shows increased substrate preference towards glucose and impaired mitochondrial function, the cause‐and‐effect relationship between these characteristics is incompletely understood. To explore these pathogenic processes, we compared cardiac mitochondrial proteomes of 20‐month‐old SHR and Wistar‐Kyoto controls by iTRAQ™‐labelling combined with multidimensional LC/MS/MS. Of 137 high‐scoring proteins identified, 79 differed between groups. Changes were apparent in several metabolic pathways, chaperone and antioxidant systems, and multiple subunits of the oxidative phosphorylation complexes were increased (complexes I, III and IV) or decreased (complexes II and V) in SHR heart mitochondria. Respiration assays on skinned fibres and isolated mitochondria showed markedly lower respiratory capacity on succinate. Enzyme activity assays often also showed mismatches between increased protein expression and activities suggesting elevated protein expression may be compensatory in the face of pathological stress.
Proteomic analysis of an imatinib‐resistant K562 cell line highlights opposing roles of heat shock cognate 70 and heat shock 70 proteins in resistance
Authors: Pocaly Marion , Lagarde Valérie , Etienne Gabriel , Dupouy Maryse , Lapaillerie Delphine , Claverol Stéphane , Vilain Sébastien , Bonneu Marc , Turcq Béatrice , Mahon François‐Xavier , Pasquet Jean‐Max
Published: June 2008

Understanding the molecular basis of resistance to imatinib, a tyrosine kinase inhibitor used as front‐line therapy in chronic myeloid leukemia, remains a challenge for successful treatment. In an attempt to identify new mechanisms of resistance, we performed a comparative proteomic analysis of an imatinib‐resistant cell line generated from the erythroblastic cell line K562 (K562‐r) for which no known mechanism of resistance has been detected. Bidimensional gel electrophoresis was carried out to compare the protein expression pattern of imatinib‐sensitive and of imatinib‐resistant K562 cells. Among the 400 matched spots on five pairs of gels, only 14 spots had a significantly increased or decreased expression leading to the identification of 24 proteins identified as scaffold proteins, metabolic enzymes, DNA translation and maturation, and chaperon proteins. Among the chaperon family, only Hsp70 and Hsc70 are overexpressed in K562‐r, results confirmed by Western blotting. We recently reported the participation of Hsp70 overexpression in imatinib resistance whereas a role for Hsc70 has yet to be determined. Hsc70 is not involved in imatinib resistance as the inhibition of its expression by siRNA does not restore sensitivity to imatinib. In contrast, the induced decreased expression of Hsc70 was accompanied by a greater overexpression of Hsp70. This proteomic study therefore suggests opposing roles of Hsp70 and Hsc70 in imatinib resistance.
Polymerization and nanocomposites properties of multifunctional methylmethacrylate POSS
Authors: Liu Ying‐Ling , Tseng Min‐Chi , Fangchiang Meng‐Han
Published: June 2008

Thermally induced polymerization of multifunctional methylmethacrylate POSS (MMA‐POSS) was studied in this work for preparation of polymer/POSS nanocomposites. The polymerization of MMA‐POSS could be promoted with benzoyl peroxide (BPO). Self‐assembly of POSS into a layer‐by‐layer structure in the MMA‐POSS polymer (TP‐MMA‐POSS) is observed with a transmission electron microscopy. An ultra‐low‐k value of about 1.85 is measured with TP‐MMA‐POSS. In addition, polyimide‐POSS nanocomposites are also prepared. These nanocomposites demonstrate good homogeneity and enhanced mechanical properties. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5157–5166, 2008