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This paper represents the first report of thermoplastic starch (scCO2TPS) and glutaraldehyde (GA) modified TPS resins (scCO2TPS100GAx), gelatinized and/or modified with the aid of supercritical carbon dioxide (scCO2). The melt flow rate, initial and retention values of tensile strength (σf) of TPS and GA-modified TPS prepared using scCO2 fluid were considerably higher than those of TPS and TPS100GAx materials prepared in the conventional way. After conditioning at 20 °C/50% RH for 56 days, the σf of properly prepared scCO2TPS100GA0.1 still remained at 17.5 MPa, which is around 3.5 times of that of the corresponding conditioned TPS100GA0.1. The moisture contents of conditioned scCO2TPS and scCO2TPS100GAx were considerably lower than those of the corresponding TPS and TPS100GAx aged for the same amounts of time. Conditioned scCO2TPS andscCO2TPS100GAx exhibited only Vh-type crystals with melting temperatures ~20°C lower than those of corresponding conditioned TPS and TPS100GAx. In comparison to TPS and TPS100GAx, more dissociated amylopectin chains with loosely hydrogen-bonded –OH groups and significantly less retrogradation was found for conditioned scCO2TPS and scCO2TPS100GAx.

Background Postoperative renal impairment (RI) is one of the most common complications in orthotopic liver transplantation (OLT), and it occurs in 17% to 95% of the patients who undergo the surgery. Methods We reviewed 394 consecutive patients who underwent OLT. On the basis of the preoperative renal function level (presence of renal failure (RF): SCr >1.5 mg/dL before OLT), the patients were divided into an RF group and a non-RF group. In each group, the patients were subdivided into 4 subgroups according to the type and dosage of the intra-operative use of HES (hydroxyethyl starch). The changing tendency of the SCr (serum creatinine) of each group and the ratio of the change in the SCr within the first postoperative week were compared. Results In total, 139 of 394 patients (35%) had RI within the first week after OLT (RI group); 104 patients (75%) in the RI group and 181 patients (71%) in the non-RI group required HES transfusions. The multivariate logistic regression analysis identified old age, a low pre-operative platelet level, and massive red blood cell transfusions as risk factors for the postoperative development of RI. The changing tendency of the SCr and the ratio of change in the SCr among the different HES subgroups showed no significant difference in the RF group or in the non-RF group. Conclusions Perioperative use of HES 200/0.5 or HES 130/0.4 has no significant effect on renal function in the first postoperative week in patients undergoing OLT.

Background and Purpose Smooth muscle transient receptor potential melastatin 4 (TRPM4) channels play a fundamental role in the development of the myogenic arterial constriction that is necessary for blood flow autoregulation. As TRPM4 channels are present throughout the vasculature, we investigated their potential role in non-myogenic resistance arteries using the TRPM4 inhibitor 9-phenanthrol.

This paper introduces the first comprehensive demonstration of new disruptive innovation technology comprising multiple Xilinx patent-pending innovations for highly cost effective and high performance Xilinx FPGA, which is so called stack silicon-less interconnect technology (SLIT) that provides the equivalent high-bandwidth connectivity and routing design-rule as stack silicon interconnect (SSI) technology at a cost-effective manner. We have successfully demonstrated the overall process integration and functions of our new SLIT-employed package using Virtex® -7 2000T FPGA product. Chip-to-Wafer stacking, wafer level flux cleaning, micro-bump underfilling, mold encapsulation are newly developed. Of all technology elements, both full silicon etching with high etch selectivity to dielectric/fast etch rate and wafer warpage management after full silicon etching are most crucial elements to realize the SLIT technology. In order to manage the wafer warpage after full Si removal, a couple of knobs are identified and employed such as top reinforcement layer, micro-bump underfill properties tuning, die thickness/die-to-die space/total thickness adjustments. It's also discussed in the paper how the wafer warpage behaves and how the wafer warpge is managed. New SLIT module shows excellent warpage characteristics of only −30 μm ~ −40 μm at room temperature for 25 mm × 31 mm in size and +20 μm ~ +25 μm at reflow temperature. Thermal simulation results shows that thermal resistance of new SLIT package is almost comparable to that of standard 2000T FCBGA package using TSV interposer with standard heat sink configuration and air wind condition. The reliability assessment is now under the study.

Abscisic acid (ABA) regulates plant responses to various environmental stresses. Oxidative cleavage of cis-epoxycarotenoids catalyzed by 9-cis-epoxycarotenoid dioxygenase (NCED) is the critical step in the biosynthesis of ABA in higher plants. Using a homologous cloning approach, a NCED-like gene (designated as TaNCED1) was isolated from wheat (Triticum aestivum). It contained an open reading frame of 1 848 bp and encodes a peptide of 615 amino acids. Multiple sequence alignments showed that TaNCED1 shared high identity with NCEDs from other plants. Phylogenetic analysis revealed that TaNCED1 was most closely related to a barley HvNCED1 gene. The predicted 3D structure of TaNCED1 showed high similarity with other homologues. Southern blot analysis indicated that TaNCED1 was a single copy in the genome of wheat. TaNCED1 was differentially expressed in various organs and the expression was up-regulated by low temperature, drought, NaCl, and ABA. Heterologous expression of TaNCED1 in tobacco (Nicotiana tabacum) significantly improved its drought tolerance. Under drought treatment, TaNCED1-overexpressing transgenic tobacco plants exhibited higher germination rate, higher relative water content, content of soluble sugars and of ABA when compared with the wild type plants.

An integrated nanoscale light-emitting diode is used as an electrically driven optical source for exciting two-dimensionally localized gap plasmon waveguides with a 0.016λ2 cross-sectional area. Electrically driven subwavelength optical nanocircuits for routing, splitting and directional coupling are demonstrated in compact and relatively low-loss gap plasmon waveguide structures.

Two experimental high silicon high carbon steels (with 5 and 24 ppm of boron separately) have been investigated for the development of superbainite structure. After austenitisation, the specimens were held respectively at three different isothermal transformation temperatures (150, 200, and 300°C) for a variety of time intervals. The microstructures were examined via optical metallography (with microhardness measurement) and transmission electron microscopy. It was found that after isothermal transformation at 200°C for 10 days, both steels produced a high volume fraction of sheaf structures with nanometre scaled bainitic ferrite subunits, which contributed to an ultrahigh microhardness, up to 675 HV. It was also found that adding 24 ppm of boron accelerated the bainitic transformation in the early stage of isothermal transformation at 200°C, but did not have a significant effect on reducing the finish transformation time. Both isothermal temperature of 150 and 300°C could not lead to the developm...

A near infrared reflective (NIR, nickel antimony titanium yellow rutile) pigment filler was incorporated into a polyethylene terephthalate (PET) matrix via a melt blending approach to increase the infrared reflection of PET and limit the thermal heat accumulation in light of environmental and energy conservation concerns. Two different types of surface modifiers, polyethylene glycol (PEG) and cetyltrimethylammonium bromide (CTAB), were used to modify the NIR surface, as NIR–PEG and NIR–CTAB fillers, to investigate the surface modification effect. Fourier transform infrared spectroscopy (FTIR), a Zetasizer, and electron spectroscopy for chemical analysis (ESCA) results suggested a successful adsorption of the organic modifiers onto the NIR surface. Thermogravimetric analysis indicated a higher adsorption degree for the CTAB modifier than the PEG modifier due to the electronic interaction between CTAB and NIR. The thermal crystallization temperature (Tc) for neat NIR-filled samples decreased with increasing...

The nano-scale local voids on Young's modulus and hardness of thin silicon and diamond films are studied. The molecular dynamics is employed to study the contact deformation and breakdown mechanics between atoms during the nano-indentation process. The worse mechanical properties are obtained when the sizes of void are increased or the locations of voids are closed to the film surface. Numerical results indicate that the proposed molecular dynamics model is feasible to illustrate the nano-indentation process. The results indicate that the existence of local voids may reduce the values of Young's modulus and hardness significantly.

Semiconductor companies have developed 2.5D IC integration technology, which applies a silicon interposer with Cu through silicon vias (Cu TSVs) as a platform for interconnecting and integrating heterogeneous chips horizontally and vertically as a transition approach to 3D IC. The existing Cu TSVs might make the silicon interposers more fragile, due to structural non-homogeneity and weak interface. Thus, the strength determination of silicon interposers becomes one of important issues for ensuring reliability of 2.5D packages. The purpose of this study is to determine the strength of silicon interposers using a point-load-on-elastic-foundation (PoEF) test, associated with an acoustic emission (AE) method of detecting local material cracks or delamination occurring during the test before the interposer breaking. The results indicate that there are some less-than-50 dB AE signals occurring before the interposer breaking, due to the micropad crush induced by the loading-pin contact. However, the interposer breaking is found to be controlled by the maximum tensile stresses located at the corner of C4 bump pad, instead of micropad crush or Cu TSV. This failure behavior has been validated by finite element simulation and further the strength of silicon interposer has been successfully determined by experimental data associated with a finite element analysis by taking into account Cu material nonlinear properties.

Neopterin is a catabolic product of guanosine triphosphate, a purine nucleotide. Measuring neopterin concentrations in biological fluids such as urine provides information about cellular immune activation in humans under control of T helper cells. A high neopterin concentration in bodily fluids, including serum and urine, indicates cellular immunity activation, which is associated with oxidative stress. In this work, neopterin is the target molecule and imprinted onto poly(ethylene-co-vinyl alcohol) via solvent evaporation. The template molecules on the thin film are then removed, and the membrane is used as a sensing element for electrochemical urinalysis. Poly(ethylene-co-vinyl alcohol) containing 27 mol% ethylene had high imprinting effectiveness and may be integrated with the proposed portable biosensor. In random urine analysis, the cyclic voltammetry measurements of neopterin with an additional recovery method achieved >95% recovery for the neopterin concentration of 15 ng/mL.

Metallocene polyethylene (mPE)/silica nanocomposites were prepared via melt mixing. Two types of commercial fumed nanosilica, bare silica (A200) and organic modified silica (R974), were incorporated to improve the mechanical properties of the nanocomposites. Transmission electron microscopy, atomic force microscopy, and scanning electron microscopy revealed that the modified silica was dispersed slightly better within the mPE matrix. No distinct effects on the thermal behaviors of the fast-crystallizing mPE matrix were observed with variations in both the silica dosages and types. Thermal stability was enhanced through the addition of nanosilica, with or without surface treatment. The surface-modified silica system showed slightly higher tensile strength and Young's modulus compared with the bare silica system, as evidenced by a rheological study using a Cole-Cole plot to assess enhanced polymer matrix-dispersed silica interactions, especially for high dosages of organic modified silica. A limited increment in the dynamic storage modulus for modified silica cases, completely opposite of that observed for bare silica cases, was due to the low-aspect ratio of smaller agglomerates from highly dispersed organic modified silica within the mPE matrix. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers.

Magneto-impedance (MI) of a double-barrier MgO magnetic tunnel junction (DMTJ) is measured as a function of frequency (20 Hz–3 MHz) and DC bias (−1 to 1 V) under magnetic parallel and antiparallel states. A strong nonlinear effect is observed at all frequencies and the MI changes from positive to negative at the relaxation frequency ∼1/RC. A frequency–dc bias ( f – V ) “phase diagram” is mapped out to describe the combination effects of the magneto-impedance response. The decay of the tunnel magneto-resistance (TMR) and tunnel magneto-capacitance (TMC) at high voltage is sufficiently reduced by the double-MgO barrier. The V1 / 2 (the voltage that magnetic response drops to 1/2 of its maximum) of TMC reaches an average value of ∼1.35 V, which is larger than the V1 / 2 of TMR ∼0.95 V, suggesting that the response of TMC is more stable than TMR for high frequency application.

A coconut shell activated carbon precursor was modified by impregnation with phosphoric acid. The effects of the particle diameter of the impregnated activated carbons (IACs) on the thickness, pressure resistance, and face velocity of a chemical filter were investigated. Furthermore, volatile organic compounds (VOCs) adsorption experiments were carried out to determine the relationship between the removal efficiency and the chemical properties of the adsorbents. The effects of various parameters such as challenge gas concentration, saturated adsorption ratio, impregnation method and impregnant contents were investigated. The results showed that the effect of face velocity on pressure resistance is larger than that of the thickness, that 0.25 M phosphoric acid impregnation of activated carbon can raise VOC removal efficiency by 2–3% (toluene: from 95.8% to 98.1%, isopropanol: from 95.2 to 97.2%), and that the optimal impregnation time is around 1.5 h. A simple shaking impregnation method exhibited better performance than the ultrasonic method.

Photoluminescence spectroscopy has been employed in order to explore the optical emission properties of a single CuO nanowire, grown on a copper grid in static air by simple thermal oxidation method. As the diameter of the single tapered CuO nanowire decreases, the green emission of the nanowire gradually shifts towards the higher energy side. A steady blue shift of 20 nm of the photoluminescence (PL) peak has been attributed to nanosize effect. Higher surface to volume ratio and enhanced surface defects along the growth direction of the nanowire might be responsible for the observed PL behavior. In addition, crystallization process along the length of the nanowire during growth to form pure CuO structure from the precursor state may also have some role in observed shift in the PL peak.

A study of the influence of embedded circular hollow vascules on structural performance of a fibre-reinforced polymer (FRP) composite laminate is presented. Incorporating such vascules will lead to multi-functional composites by bestowing functions such as self-healing and active thermal management. However, the presence of off-axis vascules leads to localized disruption to the fibre architecture, i.e. resin-rich pockets, which are regarded as internal defects and may cause stress concentrations within the structure. Engineering approaches for creating these simple vascule geometries in conventional FRP laminates are proposed and demonstrated. This study includes development of a manufacturing method for forming vascules, microscopic characterization of their effect on the laminate, finite element (FE) analysis of crack initiation and failure under load, and validation of the FE results via mechanical testing observed using high-speed photography. The failure behaviour predicted by FE modelling is in good agreement with experimental results. The reduction in compressive strength owing to the embedding of circular vascules ranges from 13 to 70 per cent, which correlates with vascule dimension.

A multisegment structure of Co/Cu nanowires with tunable perpendicular anisotropy, associated with phase transformation, was fabricated. The mixed crystal structure, formed by doping nano grains of the hcp phase into the fcc phase in the cobalt structure, markedly improves the perpendicular anisotropy. Cobalt nano grains with the hcp phase with a preferred orientation, which were transformed from (100) to (002), by doping fcc nano grain with high preferred (111) orientation and additionally the effective magnetocrystalline energy density of mixed structure was increased, the perpendicular magnetic anisotropy can be enhanced and tunable. The magnetoresistance ratios along the parallel and perpendicular axes of nanowires are 23.4% and 7.2% respectively. This novel approach promises to be of strong interest for subsequent fabrication of phase-locked arrays of spin transfer nano-oscillators with increased output power for microwave applications.

Background The advanced glycation end products (AGEs) accumulate in joints of osteoarthritis patients. This study aimed to investigate the roles of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) pathways in AGE-mediated cartilage damage. Materials and methods Methylglyoxal-modified albumin was used as the source of AGE. Porcine and human chondrocytes were prepared from the joint cartilage of pigs and osteoarthritis patients. The activation of COX-2, iNOS, nuclear factor-kappaB (NF-κB), activator protein-1 (AP-1) and protein kinases was determined by Western blotting, kinase assay, electrophoretic mobility shift assay (EMSA) or transfection assay. Prostaglandin E2 (PGE2) and NO concentrations were determined by enzyme-linked immunosorbent assay (ELISA) and Griess reaction respectively. The enzymatic activity of COX was determined by measuring the conversion of arachidonic acid to PGE2. The release of sulphated glycosaminoglycan and the intensity of Safranin O staining were used to measure cartilage degradation. Results AGE potently induced COX-2-PGE2 and iNOS-NO activation in porcine and human chondrocytes. Meanwhile, the upstream molecules regulating COX-2/iNOS activation, such as AP-1, NF-κB, extracellular signal regulated protein kinase (ERK) and c-jun N-terminal kinase (JNK), were activated by AGE. Although AGE could not activate p38 directly, by measuring COX enzyme activity, the inhibition of p38 resulted in suppressing AGE-induced conversion of arachidonic acid to PGE2. Furthermore, successful blockage of either COX-2 or NOS activity significantly reduced AGE-mediated proteoglycan release and cartilage degradation. Conclusions This study highlights the significance of COX-2 and iNOS pathways in AGE-mediated OA pathogenesis and their potential as therapeutic targets that are beyond pain killing for OA treatment.

An inherent voltage occurs in cement paste, making the material an electret. Both poling (up to 225 V/m DC, causing long-range ion movement) during the 24 h setting and the use of sodium silicate liquid (which provides Na+ ions) as an admixture were found to increase the inherent voltage, in addition to making the voltage more stable and better controlled. Without poling and sodium silicate, the inherent voltage after curing varied in sign and magnitude in an uncontrolled fashion among specimens poured from the same mix; for the same specimen, it varied significantly with the curing time and asystematically during the first 10 days of curing and stabilised thereafter. With both sodium silicate and poling, the voltage was positive (same polarity as the poling voltage), decreased with time throughout curing, and levelled off at a voltage that increased with increasing sodium silicate content, with the highest value attained in the present study being 0·35 V. The time constant for depoling during curing ranged from 2 to 7 days in the initial depoling period (up to 11 days), and ranged from 74 to 150 days in the subsequent period.

Effects of nitrate ðNO � Þ, chloride (Cl � ), sulfate ðSO 2� 4 Þ, and acetate (Ac � )o n Cu 2+ adsorption and affinity of the adsorbed Cu 2+ were evaluated in two Fe and Al enriched variable charge soils from Southern China. The maximum adsorption of Cu 2+ (M, a parameter from the Langmuir isotherm model) in the presence of different anions decreased in the order Cl � > Ac � > NO � > SO 2� 4 for both soils. The clayey loamy soil (mixed siliceous thermic Typic Dystrochrept, TTD), developed on the Arenaceous rock, adsorbed less Cu 2+ than the clayey soil (kaolinitic thermic Plinthudults, KTP), derived from the Qua- ternary red earths, regardless of anion type present in the medium. The affinity of adsorbed Cu 2+ to both soils could be characterized by the Kd (distribution coefficient) values and successive extraction of the adsorbed Cu 2+ with 1-mol NH4Ac L � 1 . The log10Kd value was smaller for the TTD soil than for the KTP soil and decreased in the order of Cl � > NO � > SO 2� 4 > Ac concentrations, and the delta pH values at the highest Cu 2+ level were 0.5, 0.63, and 0.55 U for the TTD soil and 0.79, 0.84, and 0.93 U for the KTP soil, respectively for the three anions. The presence of Ac � had a minimal influence on the equilibrium solution pH because of the buffering nature of the NaAc/HAc medium which buffered the released protons. The effects of anions on Cu 2+ adsorption and affinity of the adsorbed Cu 2+ were dependent on anion types and were apparently related to the altered surface properties caused by anion adsorption and/or the formation of anion- Cu 2+ complexes.

Mosquito melanization involves hydroxylation of tyrosine to dopa, which then is oxidized to dopaquinone by phenoloxidase, or decarboxylated to dopamine by dopa decarboxlase (DDC). An Armigeres subalbatus cDNA encoding DDC was cloned and real-time PCR analysis revealed increased transcripts in blood-fed and microfilariae (mf)-inoculated mosquitoes. A double subgenomic Sindbis virus was used to silence DDC and assess its role in melanization of mf. DDC transcription and activity were significantly decreased in silenced mosquitoes, as was the degree of mf melanization 48 h postinoculation; however, melanization increased after 72 and 96 h, demonstrating that DDC influences the rate of melanization. DDC-silenced mosquitoes also exhibit high mortality, over-feeding and abnormal movement, consistent with an involvement of DDC in neurotransmission.

We report on the preparation and characterization of the variation of B′-site transition metal in Sr 2 CrMO 6 (M=Mo, W) with double perovskites structure. The magnetic susceptibility shows that Sr 2 CrMoO 6 and Sr 2 CrWO 6 are antiferromagnets with T N =40 and 30 K at H =1 T, respectively. In addition, a large magnetoresistance ratio (MR) of ∼38% ( H =3 T) at 5 K was observed in the Sr 2 CrWO 6 compound. However, the Sr 2 CrMoO 6 compound does not show any significant MR even at high fields (MR∼4%; H =3 T and 5 K). The measured O K-edge X-ray absorption is in agreement with the calculated O p -density of states for both compounds.

Haemoglobin, methaemoglobin, blood nitrite concentration and acid-base balance were measured in European eel Anguilla anguilla following exposure to 0 (control), 0.142, 0.356, 0.751 and 1.549 mM nitrite in fresh water for 24h. Blood GOT (glutamate oxaloacetate transaminase) and GPT (glutamate pyruvate transaminase) activities and whole animal ammonia-N and urea-N excretions were also measured. Blood nitrite, methaemoglobin, PO 2 (oxygen partial pressure), GOT, and whole animal ammonia-N excretion and urea-N excretion increased directly with increasing ambient nitrite concentrations, whereas blood pH, PCO 2 , and HCO - 3 were inversely related to ambient nitrite concentration. An accumulation of nitrite in the blood of A. anguilla following 24 h exposure to elevated ambient nitrite as low as 0.751 mM increased its blood methaemoglobin, PO 2 , GOT and nitrogen excretion, but decreased its PCO 2 (carbon dioxide partial Dressure), HCO - 3 and functional haemoglobin.

An electron conductive BaTiO3 crystal without shallow traps is desirable for photorefractive applications. For this report, a nominally undoped BaTi03 crystal was grown by the top-seeded solution method, then cut into several pieces, and these pieces were systematically reduced. By investigating the absorption spectra, the light-induced absorption changes, the two-beam coupling gain and the dark-conductivity, we found that the sample reduced at 10−12 atm oxygen partial pressures to be electron conductive and the shallow traps to be inactive.

Single-phase La 1.2 (Sr 1.4 Ca 0.4 )Mn 2 O 7 has been synthesized from the aqueous solution of metal nitrates and citric acid by the sol–gel technique. Small particle size with high homogeneity of the powder was obtained. The valence of Mn is determined to be 3.45±0.05 by chemical titration. The MR ratio [ ρ − ρ ( H )]/ ρ ( H ), is 115% (102 K, 1.5 T) for the composition prepared by the citrate route, and is nearly three times larger than that of the sample prepared by solid state reaction.

The strong thermal hysteresis of thermoelectric power (TEP) in Pr0.5(Sr, Ca)0.5MnO3 is observed. A simple estimation shows that the electrostatic energy between Mn3+/Mn4+ alone cannot account for the large shift of Tco with changing A size. Based on our experimental evidence, we attribute the distinct features exhibited in the thermal hysteresis to the manifestation of the underlying competition between the delocalization and localization effects assisted respectively by the double exchange interaction and the charge ordering. The observed features include the following: (1) the A-size effect can depress Tco by as much as 70 K for Pr0.5Sr0.5-xCaxMnO3; (2) large thermal hysteresis of resistivity and TEP are exhibited in Pr0.5Sr0.5-xCaxMnO3; (3) for x = 0.3 and 0.4, the thermal hysteresis is larger than those of x = 0.1 and 0.5 and (4) magnetic field induces a large shift in Tco.

A compact multichannel Superheated Superconducting Grain detector (SSG) has been irradiated by the T9 beam (mostly composed by high energy electrons) of the SPS machine at CERN. The SSG detector consists of a set of cylindrical suspensions of tin grains with various filling factors, all of them parallel to the beam line and kept in an 3 He – 4 He single-dilution chamber. Transitions to the normal state of the grains were detected with a GaAs high electron mobility field effect transistor (HEMFET) preamplifier cooled to 4.2 K. We present a preliminary analysis of the results obtained with beam energies from 1 to 14 GeV and a 33–37 μm size distribution of the grains.

The effect of doping Cr in the Mn site of the La1.2Sr1.8Mn2O7 system has been studied. Addition of Cr modifies the transport and magnetic properties of the parent phase. With increasing Cr, the insulator-metal transition observed in the parent phase is suppressed and insulating behaviour is induced. In the range of doping studied (25%), the compositions show ferromagnetic behaviour with the Curie temperature decreasing with increasing Cr. The unit cell volume also shows a decrease. However, the magnetoresistance ratio is not significantly affected. We compare these results with an earlier study of doping Cr in the three-dimensional LaMnO3 structure, where it was seen that the ferromagnetic and magnetoresistance characteristics are sensitive to Cr doping. The results of the present study suggest that the layered manganates are more accommodative to doping compared to the three-dimensional perovskites.

The magnetic properties and thermal evolution of Tb 0.85 Na 0.15 MnO 3-y have been studied by neutron-diffraction experiments. By comparison with the TbMnO 3 sample, the results show not only small lattice parameters but also a reduction in correlation length (ξ). This is strongly correlated to the induced oxygen vacancies in Tb 0.85 Na 0.15 MnO 3-y [y≈0.15(2)].

In this work, we study the preparation and properties of bio-compatible magnetic nanoparticles for immunoassay and DNA detection. The magnetite (Fe3O4) nanoparticles were prepared by a chemical co-precipitation method and dextran was selected as the surfactant to suspend the nanoparticles. Suspended particles associated with avidin followed by biotin were qualitatively analyzed by enzyme-linked immunosorbent assay (ELISA) method. We found further the ethylenediamine blocked activated residual groups efficiently, hence enhancing the attachment of biotin for probing the avidin.

Utilization of polyhydroxylated C 60 in a condensation reaction with diisocyanated oligo(tetramethylene oxide) led to the successful fabrication of elastomeric poly(urethane-ether) networks. These polymer networks exhibit interesting thermal behavior at low temperatures, improved tensile strength and elongation at ambient temperatures, and enhanced thermal mechanical stability at high temperatures. Design of conducting elastomers was made by carrying out an in situ polymerization of conductive polymer precursors in an interpenetrating fashion at the near-surface of polyhydroxylated C 60 -hypercrosslinked elastomers. Results demonstrated that elastomers with an appreciable conductivity while retaining desirable elastic properties of the network can be achieved. The room-temperature conductivity of polyaniline interpenetrated (IPN) conducting elastomer was found to be 2.0 Scm -1 . The tensile strength and elongation at break of one conductive IPN elastomer was found to be 20 MPa and 480%, respectively. Interestingly, the strain dependent conductivity of these conducting elastomers was found to increase progressively above 200% of elongation. These results demonstrated, for the first instance, conductivity measurements of organic conducting elastomers at an elongation length of higher than 300%, showing a r.t. conductivity of >4.0 SCm -1 .

A processing technique for fabrication of conductive elastomers was demonstrated involving in situ polymerization of aniline at the near-surface region of the fullerenol crosslinked poly(urethane-ether) networks. The synthetic chemistry led to a thin layer (roughly 20 μm in thickness) of conductive polyanilines interpenetrated inside the elastomer matrix. This IPN network exhibited an appreciable conductivity along the doped polyaniline layer without deteriorating much the elasticity and tensile strength of the parent supporting elastomer. As a result, its r.t. conductivity was found to be 2.6 Scm−1 which increased to 5.4 Scm−1 at 430% elongation of the polymer film. The data represented the strain-dependent electronic properties of conducting elastomers, showing an increase of conductivity even after the elastomer being stretched above a length as much as 500% of its original size.

New plasmonic materials with tunable properties are in great need for nanophotonics and metamaterials applications. Here we present two-dimensional layered, metal chalcogenides as tunable metamaterials that feature both dielectric photonic and plasmonic modes across a wide spectral range from the infrared to ultraviolet. The anisotropic layered structure allows intercalation of organic molecules and metal atoms at the van der Waals gap of the host chalcogenide, presenting a chemical route to create heterostructures with molecular and atomic precision for photonic and plasmonic applications. This marks a departure from a lithographic method to create metamaterials. Monochromated electron energy-loss spectroscopy in a scanning transmission electron microscope was used to first establish the presence of the dielectric photonic and plasmonic modes in M2E3 (M = Bi, Sb; E = Se, Te) nanoplates and to observe marked changes in these modes after chemical intercalation. We show that these modal properties can also be tuned effectively by more conventional methods such as thickness control and alloy composition of the nanoplates.

The condensation of H2O on ice multilayers on Ru(001) was studied using both molecular beam and optical interference techniques as a function of surface temperature. From the beam reflection technique, the H2O sticking coefficient, S, was determined to be S = 0.99 ± 0.03 at temperatures between 85 and 150 K and was independent of incident angle (0−70°) and beam energy (1−40 kcal/mol). The condensation coefficient, α, was dependent on both the incident H2O flux and the desorption H2O flux at the various surface temperatures. The magnitude of α varied continuously from unity at T < 130 K to zero at higher temperatures. The optical interference experiments yielded condensation coefficients and sticking coefficients of α = S = 0.97 ± 0.10 at temperatures from 97 to 145 K where the H2O desorption flux was negligible with respect to the incident flux. The optical interference measurements monitored the ice film thickness versus H2O exposure time and were dependent on the refractive index, n, and the density, ρ,...

We report observation of near-infrared photoluminescence from free-standing, vertically aligned germanium nanowires grown on a (111)-oriented silicon substrate. The energy of the photoluminescence peak is very close to that of the bulk crystalline germanium direct band gap. The intensity shows an approximately quadratic dependence on excitation laser power and decreases with decreasing temperature. The peak position exhibits a redshift with increasing laser power due to laser-induced heating of the wires. These observations indicate that the photoluminescence originates from the direct band-gap recombination in the germanium nanowires.

We demonstrate electroluminescence (EL) from light-emitting diodes (LEDs) on highly strained germanium (Ge) membranes. Electrical measurements show an on-off ratio increase of one order of magnitude in membrane LEDs compared to bulk. The EL spectrum from the 0.76% strained Ge LED shows a 100nm redshift of the center wavelength. We also discuss the implications for highly efficient Ge lasers.

Chitosan/clay (nano)composites were prepared by using a special quaternary ammonium intercalating agent coupled with a silanol group to facilitate the organic clay formation. Exfoliated clay in the chitosan matrix was attained at the higher intercalant dosages through X-ray diffraction (XRD) and transmission electron microscope (TEM) analyses. Optical transmittance for the (nano)composites increased slightly with increasing the amount of intercalants in the clays. In light of the hydrophobic component on the intercalant and the effective clay content, the interfacial interaction between chitosan and modified clay may not be strong enough to render higher mechanical properties, even though the partially exfoliated clays were achieved to provide high interfacial area for the dispersed phase and the matrix. An optimum Young’s modulus was thus found for (nano)composites using modified clay at a medium dosage of intercalant, which resulted from the balance of the dispersion status and interfacial interaction. This outcome indicated high dispersion of modified clay may not guarantee high mechanical properties of (nano)composites. The antimicrobial property of chitosan against Escherichia coli (E. coli) increased further with the addition of modified clays, in which the intercalant exhibiting the antimicrobial function. The modified clay at an optimum dosage of modifier to balance the mechanical properties and antimicrobial property was attained.

This work presents a novel method to introduce a sustainable biaxial tensile strain larger than 1% in a thin Ge membrane using a stressor layer integrated on a Si substrate. Raman spectroscopy confirms 1.13% strain and photoluminescence shows a direct band gap reduction of 100meV with enhanced light emission efficiency. Simulation results predict that a combination of 1.1% strain and heavy n(+) doping reduces the required injected carrier density for population inversion by over a factor of 60. We also present the first highly strained Ge photodetector, showing an excellent responsivity well beyond 1.6um.

We demonstrate room-temperature electroluminescence (EL) from light-emitting diodes (LED) on highly strained germanium (Ge) membranes. An external stressor technique was employed to introduce a 0.76% bi-axial tensile strain in the active region of a vertical PN junction. Electrical measurements show an on-off ratio increase of one order of magnitude in membrane LEDs compared to bulk. The EL spectrum from the 0.76% strained Ge LED shows a 100nm redshift of the center wavelength because of the strain-induced direct band gap reduction. Finally, using tight-binding and FDTD simulations, we discuss the implications for highly efficient Ge lasers., Comment: 4 Pages, 5 figures

α-Haloformylarylhydrazine hydrohalides 1 were prepared through ring opening of 3-aryl-4-halosydnones 7 with hydrohalic acids in EtOAc in moderate yields. Reactions between compounds 1 and primary alcohols gave alkyl 1-arylhydrazinecarboxylates 12 and 14, important intermediates in syntheses of antiinflammatory drugs. Compounds 16,4-aryl-2-(arylhydrazin-1-y1)-1,3,4-oxadiazolin-5-ones, and compounds 18, 1,4-diaryl-1,4-dihydro-1,2,4,5-tetrazine-3,6(2H,5H)-diones, were synthesized by self-dimerization of compounds 1. Compounds 18 were also converted to compounds 17 via intramolecular rearrangement. Structural elucidation and verification of the reaction mechanisms are presented.

In hexane solution, the decomposition of (1,1,6,6-tetrafluoro-3,4-di-t-butyl-1, 6-disila-2,4-hexadiene)ruthenium (II) tetracarbonyl 2, led to formation of compound (η4-1,1-difluoro-3,4-di-t-butyl-sila-2,4-cyclopentadiene)ruthenium(O)tricarbonyl 3 and monomeric SiF2 that added to cyclic diene compound 1,1,2,2-tetrafluoro-4,5-di-t-butyl-disila-3, 5-cyclohexadiene 1, to form bicyclic compound 4. SiF2 was for the first time generated at such a low temperature and trapped with a conjugated diene.

Liver antioxidant defense and detoxification enzymes in murine AIDS-infected mice fed cereal based-diet or purified diet were studied with 32 C57BL/6 female mice in a 2×2×2 (diet × virus × period) treatment design. The mice were divided into two groups and fed Purina mice chow or a liquid diet. One week later, half of the mice in each diet group were injected intraperitoneally with LPBM5 murine retrovirus (MAIDS) stock. Two and 4 weeks after infection, half of the mice in each of the 4 treatment groups were killed, and the livers were excised for biochemical analysis. The results showed that MAIDS virus infection significantly decreased activities of glutathione peroxidase (GP) at 2 weeks postinfection in the liquid diet group, superoxide dismutase (SOD) at both periods in the liquid diet group, and glutathione-S-transferase (GST) toward 1,2-dichloro-4-nitrobenzene (DCNB) at both periods in both diet groups when compared to the control groups. MAIDS virus infection did not affect reduced glutathione (GSH) levels, or activities of catalase and glutathione reductase (GR). GSH levels and activities of catalase and GSTs were significantly lower in the mice fed the liquid diet than in those fed mice chow. Virus-mediated decline in antioxidant defense and detoxification capability of MAIDS infected mice may contribute to further development of the disease. The results suggest that chow diet provides a higher antioxidant defense capability than the liquid diet.

We have investigated the crystal structure and magnetic properties of the new series of ordered double perovskite oxides (Sr 2− x Ca x )FeMoO 6 (0⩽ x ⩽1.0). A monotonous decrease of the lattice constants ( a and c ) has been found with increasing x . Such an effect may also give rise to a distorted structure with Fe–O–Mo angle changing from 180° for x =0 to 162° for x =1.0. The magnetization increases from x =0 to 0.5 and then slightly decreases from x =0.5 to 1.0. Such complex magnetic behavior is strongly correlated to the chemical size effect (corresponding to the internal pressure) in the title compounds.

A novel method to introduce more than 0.6% biaxial tensile strain and achieve a 60meV direct band gap reduction in epitaxially grown germanium is demonstrated. Possible applications include high efficiency germanium lasers on silicon substrates.

Barium zirconium phosphate (BaZr4P6O24), a member of a new family of low-thermal-expansion materials known as NZP, was synthesized by the solution sol-gel method, and sintered ceramics were prepared at 1100–1600 °C. The effect of sintering parameters such as time and temperature on the microstructure and phase composition was studied. BaZr4P6O24 is known to possess anisotropy in its axial thermal expansions, which usually causes microcracking in the sintered bodies when cooled. The microcracking activity of the sintered samples was examined by acoustic emission measurements.

GaN and InGaN layers were grown on annealed 20 and 50nm Al2O3/ZnO substrates by metalorganic chemical vapor deposition (MOCVD). GaN was only observed by high resolution x-ray diffraction (HRXRD) on 20 nm Al2O3/ZnO substrates. Room temperature photoluminescence (RT-PL) showed the red shift of the GaN near band-edge emission, which might be from oxygen incorporation forming a shallow donor-related level in GaN. HRXRD measurements revealed that (0002) InGaN layers were also successfully grown on 20nm Al2O3/ZnO substrates. In addition, thick InGaN layers (∼200-300nm) were successfully grown on Al2O3/ZnO and bare ZnO substrates. These results are significant as previous studies showed decomposition of the layer at InGaN thicknesses of 100nm or less.