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This experiment was conducted to determine if CLA could be transferred from sows to their offspring through the umbilical cord or milk. Eighteen pregnant Dalland sows of mixed parity were used in a completely randomized block design based on parity and BW. The sows were allotted to 1 of 3 groups and fed diets containing 0, 0.5, or 1.0% CLA during the last 50 d of gestation and throughout a 26-d lactation (n = 6). Umbilical cord blood was sampled at parturition. Colostrum and milk were collected from each sow on d 2 and 15 after farrowing. Samples of blood, backfat, and the LM were obtained from piglets at 2 and 26 d of age. Sow reproductive performance and piglet growth were not altered by CLA supplementation during the late gestation and lactation periods. The CLA supplementation of sow diets had an impact on the fatty acid profiles in colostrum and milk. Dietary CLA increased the concentrations of total SFA (linear and quadratic, P < 0.01), but reduced the total MUFA in the colostrum (linear and quadratic, P < 0.01). Although dietary CLA increased the concentrations of total SFA (quadratic, P < 0.01), it had no influence on total MUFA concentrations in the milk. In addition, feeding sows diets supplemented with CLA resulted in increases (linear and quadratic, P < 0.01) in the CLA content of plasma, backfat, and the LM in their offspring. However, trans-10, cis-12-18:2, rather than cis-9, trans-ll 18:2, was detected in the umbilical cord blood, which indicates that CLA may be transported from the sow to the fetus in an isomer-specific manner. Key words: conjugated linoleic acid, fatty acid profile, milk, piglet, plasma, transfer pattern doi: 10.2527/jas.2009-2354

We report that silver ion ([Ag.sup.+]) uptake is enhanced by 4-aminopyridine (4-AP), a well known voltage-sensitive potassium ion channel ([K.sub.v]) blocker. Both bacterial (Escherichia coli) and mammalian (3T3 fibroblast) cells were used as model systems. [Ag.sup.+] uptake was monitored with a scanning electrochemical microscope with an amperometric [Ag.sup.+] ion-selective electrode ([Ag.sup.+]-ISE) and the respiration rates of E. coli cells were measured by oxygen reduction at an ultramicroelectrode. The results showed that not only the amount but also the rate of silver uptake by the cells increased significantly when 4-AP was added to the solution. For fibroblasts, the [Ag.sup.+] uptake rate was 4.8 x [10.sup.7] ions per cell per sec without 4-AP compared with 1.0 x [10.sup.8] ions per cell per sec with 0.2 mM 4-AP. For E. coli cells, the uptake rate was 1.5 x 104 ions per cell per sec without 4-AP vs. 3.5 x [10.sup.4] ions per cell per sec with 0.5 mM 4-AP and 5.9 x [10.sup.4] ions per cell per sec with 1 mM 4-AP. Thus, 4-AP might be useful where silver is used as antimicrobial agent to speed its uptake. E. coli | scanning electrochemical microscope | silver ion

We report the use of a micropipet-supported ITIES (interface between two immiscible electrolyte solutions, also called a liquid/liquid (L/L) or water/oil (W/O) interface) as a scanning electrochemical microscopy (SECM) tip to detect silver ion and explore [Ag.sup.+] toxicity in living cells. A 1,2-dichloroethane solution containing a commercially available calixarene-based [Ag.sup.+] ionophore (IV) was injected into a micrometer-size glass pipet to construct an [Ag.sup.+]-selective SECM tip. The local [Ag.sup.+] concentration, down to the micromolar level, in the vicinity of living fibroblast cells, was monitored by SECM approach curves and through imaging of the uptake and efflux of [Ag.sup.+] by living fibroblast cells in real time. The results show that several stages of interaction between [Ag.sup.+] and fibroblast cells exist. Since a number of biological processes of cells are involved with non-redox-active ions, the work presented here provides a new way to explore cell metabolism, drug delivery, and toxicity assessment by SECM.

Electrochemical, spectroscopic, and mass spectrometric (MS) methods were used to probe the interaction (complexation) of silver ions and zerovalent silver species with polyamidoamine generation 1 amine-terminated (PAMA-MG1N[H.sub.2]) and generation 2 hydroxy-terminated (PAMA-MG2OH) dendrimers (DDMs). Stability constants ([K.sup.+.sub.q]) and stoichiometries (q) (i.e., the number of silver ions complexed per DDM molecule) were determined from the voltammetric data, that is, shifts in potential and changes in peak or limiting current with addition of DDM. When the mole ratio of DDM to [Ag.sup.+] is [greater than or equal to] 1, [Ag.sup.+] binds with PAMAMG2OH to form a dominant 1:1 complex with a [K.sup.+.sub.1] value of 1.1 x [10.sup.7] [M.sup.-1]. Under similar conditions, [Ag.sup.+] binds with PAMAMG1N[H.sub.2], yielding a 1:1 complex with [K.sup.+.sub.1] = 4 x [10.sup.9] [M.sup.-1], which is consistent with the finding of the MS experiments. When the mole ratio is

The bipolar conductance, BICON, technique for the measurement of solution resistance, based on the application of microsecond current pulses, as originally described by Enke and co-workers for measurements with conventional electrodes, was extended for use with ultramicroelectrodes, with a focus on its application in scanning electrochemical microscopy (SECM). When the plateau time used to make the measurement lies within the BICON conditions, the solution conductance can be obtained directly from the output without the need for calibration curves. However, decreasing the size of the ultramicroelectrode decreases the range of values that satisfy these conditions, and one must resort to calibration curves to obtain solution conductance from the measured current, which was nevertheless found to be proportional to electrolyte concentration with electrodes as small as 5 [micro]m in diameter. BICON/SECM approach curves over insulating substrates followed SECM negative feedback theory and approach curves in the presence of low (micromolar) or no added electrolyte are possible once the background conductivity is taken into account. Approach curves to a conducting substrate at open circuit potential are influenced by the solution time constant (solution resistance at the electrode tip x electrode double layer capacitance), which is a function of the tip/substrate distance, as well as the substrate size.

Ohmic contacts to n-SiC, a semiconductor material, were studied.

A new study investigates the electrical properties of W contacts to p- and n-GaN.

The effects of C12/Ar and Ar plasma damage were examined using the reverse breakdown voltage and forward turn-on voltage of n- and p-GaN Schottky diodes.

Ti+, O+, Fe+ and Cr+ were found to produce defect levels when implanted in n- and p-type GaN.

The use of the scanning electrochemical microscope (SECM) to probe the kinetics of charge-transfer processes at bilayer lipid membranes (BLM) is presented. Analysis of the SECM tip response demonstrates that an unmodified BLM behaves as an insulator, whereas a BLM doped with iodine shows some positive feedback. The SECM technique thus allows one to probe processes at BLM and determine the kinetics of the charge-transfer process. The SECM can also be used to determine the shape of the BLM.

An analysis of the role of extended and point defects and key impurities such as C, O, and H, on the optical and electrical properties of GaN was conducted. The rapid development and commercialization of blue and green light-emitting diodes (LEDs) and the achievement of long-lifetime laser diodes was followed by realization of UV photodetectors and several different electronic devices. Continued rapid development in the areas of LEDs, laser diodes, microwave and digital electronic devices, UV detectors ad high voltage unipolar and bipolar devices is expected as an improved understanding of the defect and impurity issues in these materials evolve.

A study was conducted to analyze the ion transport characteristics of two gels made from polyacrylate and polyacrylamide using scanning electrochemical microscopy (SECM). A platinum microdisk was utilized as the SECM tip while a platinum wire was used as a quasi-reference electrode. Results indicated that the transient SECM response can be utilized to obtain the diffusion coefficient of a redox species from the critical transient time as a function of tip displacement.

Electrogenerated chemiluminescence (ECL) at a scanning electrochemical microscope (SECM) tip as the tip was moved in the vicinity of insulating and conductive substrates was studied either by ion annihilation or with a coreactant. The SECM/ECL approach curves (intensity vs tip-substrate distance, d) with both insulating and conducting substrates showed a decrease in ECL intensity with a decrease in d. Modes of operation that produced sufficiently intense and stable ECL for optical imaging are possible. The needed improvements for higher resolution and the potential application of this technique for the studies of the kinetics and mechanisms of coreactant ECL reactions are discussed.

Process induced micro-scale evolutions can greatly influence the strength and resilience of a high temperature ceramic and intermetallic component. A micromechanical study, based on a unit cell approach, is carried out in the present work to investigate these evolutions during compaction of titanium aluminide multi-phase intermetallics at elevated temperatures. The quasi-coupled unit cell analysis can provide an avenue for investigating scalability and migratability of laboratory results to full scale productions with perturbed material compositions. Effects of various macro-scale process design considerations (e.g., tooling stiffness, spatial distribution of thermal fields) on micro-scale evolutions are investigated in detail. It has been observed that a more economic (and usually more flexible) container increases the likelihood of microcrack nucleations, while spatially non-uniform intra-particle thermal fields can be utilized to alleviate processing induced micro-cracks in the final compacted product. Possibilities for process design modifications are also discussed.

The extension of molecular beam epitaxy toward gallium oxide (Ga2O3) molecules deposition allows the production of Ga2O3-GaAs interfaces with excellent photochemical stability and electronic interface properties. The thermodynamical stability is up to at least 800 degrees celsius. The interfaces have a midgap interface state density in the 10 to the 10th power/square-cm e/V range. Charge trapping in the oxide is the main trapping mechanism. Interface analysis of electrical and optoelectronic data allows evaluation of the interfaces' electric properties.

Electrochemical measurements on single molecules of [(trimethylammonio)methyl]ferrocene ultramicrotips insulated at the tip with Apiezon wax. Rapid heterogeneous electron transfer reactions at the electrodes produced a current of approximately 0.6 pA/molecule. Analyses revealed that fluctuations in the tip current are influenced by cell geometry and nature of the substrate.

Reinhard Guckenberger and his co-workers[1] describe the use of a scanning tunneling microscope (STM) with high current sensitivity to image DNA on a mica surface in humid air. Because the [...]

An output power of 850 mW is obtained using an optimized microwave power AlGaAs/InGaAs pseudomorphic high electron mobility transistor, fabricated by dry etch single gate recess. At X-band, there is 50% more efficiency when operated at a CW and almost in class A condition. The device also gives good DC and high RF working. The design, working and results of the device are given.

The electrochemical behavior of a single molecule can be observed by trapping a small volume of a dilute solution of the electroactive species between an ultramicroelectrode tip with a diameter of ~15 nanometers and a conductive substrate. A scanning electrochemical microscope was used to adjust the tip-substrate distance (~10 nanometers), and the oxidation of [(trimethylammonio)methyl] ferrocene ([Cp.sub.2]FeTM[A.sup.+]) to [Cp.sub.2]FeTM[A.sup.2+] was carried out. The response was stochastic, and anodic current peaks were observed as the molecule moved into and out of the electrode-substrate gap. Similar experiments were performed with a solution containing two redox species, ferrocene carboxylate ([Cp.sub.2]FeCO[O.sup.-]) and [Os(bpy).sub.3.sup.2+] (bpy is 2,2'-bipyridyl)., A number of techniques have been used in recent years to detect single molecules or ions in different environments. These include the detection of ions that are confined in vacuum [...]

Ion milling rates of III-V nitrides have been measured as a function of Ar(+) ion beam. Ion channeling, AES and SEM enable the analysis of the influence of nitride surfaces. Ion milling rates for these samples are smaller than those of GaAs and InP. Ion milling has no influence on the surface morphology of the nitride. All these nitrides exhibit more back-scattering for Ar(+) energies up to 500 eV.

Implant isolation schemes, specifically used for dense and greatly doped III-V devices such as quantum well lasers and heterojunction bipolar transistors (HBT) generate extended defects, situated particularly at areas of strain. Diffusion of keV H+, MeV O+ and F+ ions is analyzed. MeV O+ ions are used for isolating strained quantum well lasers which work at 0.98 micrometers and keV H+ and F+ ions are used for isolating GaAs/AlGaAs HBTs.

Si+ and Be+ ions, implanted into InGaAsP grown lattice, matched to InP by molecular beam epitaxy, are experimented upon to determine the electrical activation characteristics as a function of ion dose, annealing time and annealing temperature. For both Si and Be ions, maximum doping concentrations were obtained with the electrical activation energies of 0.58 and 0.39 electron volts. High resistance layers for isolation is produced by multiple energy implant of F or H ions. The maximum sheet resistance for the InGAsP is determined for F implants by annealing at 450 degrees centigrade. Electron cyclotron resonance CH4/H2/Ar discharges at low direct (dc) basis is used in the determination of the smooth, anisotropic dry etching of the InGaASp.

The use of tri-isobutylgallium (TIBG) and tri-isopropylgallium (TIPG) for enhancing the metalorganic molecular beam epitaxial growth of InGaP was investigated. The result showed that the incorporation rate of carbon decreased as the temperature increased. The measured lattice constant varied linearly with the flow. The band gap varied discontinuously with the lattice constant.

A study was conducted on the effectivity of using mega electronvolt (MeV) O+ ion implantation for isolation of GaAs/AlGaAs heterojunction bipolar transistors (HBTs). High sheet resistances were observed in the GaAs epitaxial layers. The presence of a residual conductivity was attributed to hopping processes with small activation energies. The study shows that MeV can effectively produce HBTs with optimal direct current properties. MeV application also proved to be clear due to the thick layer stuctures involved.

High quality Pnp heterojunction bipolar transistors can be obtained through the use of carbon: aluminum gallium arsenic and tin doping from tetraethylin during metalorganic molecular beam epitaxy growth. Large area devices with gains of 45 at a base doping level of 1.5 x 10 (super 9) cm (super -3) were demonstrated. The slight doping levels were obtained with carbon and tin reducing the parasitic resistances in the transistor.

A single-energy, MeV implant isolation method for thick II-V semiconductor device structures is presented. The process greatly simplifies conventional keV implant isolation, which uses ten separate ion energies in isolating HBT structures. Damage profile is constant over the primary part of the ions range. The damage usually found with the MeV ions end of range can be kept secure in the underlying substrate.

MOST MICROSCOPES OPERATE ON THE BASIS OF THE interaction of electromagnetic radiation with a sample to produce a two-dimensional (2-D) image. The appearance of the image is based on the [...]

A study measured minority electron diffusion length in p-type, Sb-doped ZnO as a function of temperature using the electron beam induced current technique. Irradiation with a low energy (5kV0 electron beam resulted in an increase of diffusion length with a similar activation energy (219 plusmn 8 meV).

The current-potential curve at a 2.8-nanometer-radius electrode immersed in a solution containing micromolar concentrations of a redox couple, [(trimethylammonio)methyl] ferrocene (Cp.sub.2][FeTMA.sup.2+], shows discrete steps (a coulomb staircase) representing single electron-transfer events. Discrete potential steps are also found in the current-time curve as the electrode potential relaxes back to equilibrium after a coulostatic potential step., We describe electrochemical current-potential (i-V) curves at nanometer-size electrodes that are characterized by stepwise changes in current (rather than the usual smooth curves found at larger electrodes). These represent single [...]

The morphology of ultrathin AlN/GaN high electron mobility transistors without or with TiAlNiAu Ohmic contacts is examined by using transmission electron microscopy and associated analytical methods. The contact inclusion (CI) density has increased with increasing annealing temperature but the lowest specific contact resistivity is obtained for structures annealed at 850 [degree]C and the AlN layers have remained intact in dislocation-free areas of all samples.

The electrochemical detection of single iridium oxide nanoparticle (Ir[O.sub.x] NP) collisions on a NaB[H.sub.4]-treated Pt ultramicroelectrode (UME) is described. The observed current is very sensitive to the material and surface state of the measuring electrode, a NaB[H.sub.4]-treated Pt UME is significant for obtaining reproducible results.

An extremely small, conically shaped Pt microelectrode tip (with a radius of 30 nanometers) and the precise positioning capabilities of the scanning electrochemical microscope were used to penetrate a thin [...]

The thermal and chemical stability of potential dielectrics for GaN-based devices in a GaN metal organic chemical vapor deposition (MOCVD) environment is examined and their suitability as a gate dielectric and as a regrowth mask for the selective area growth of GaN is discussed. The results have shown that the [Sc.sub.2][O.sub.3] films dissolved into MgO during annealing and that a ScN film has not formed on the surface.

The electrogenerated chemiluminescence (ECL) emission is obtained from a prepared suspension of graphene oxide nanoparticles (NPs) and an electrochemically oxidized graphite layer on highly oriented pyrolytic graphite (HOPG). The ECL of the individual graphene oxide NPs is probed by using a coreactant at relatively high concentration.

Electrochemical method is used to screen the metal nanoparticle (MNP) sizes in a liquid solution and also provide a platform for studying the kinetics of electrocatalysis at single MNPs. It is shown that the current flows when the MNPs switch on an electrocatalytic reaction at their surfaces at a potential where the detector electrode has shown negligibly small electrochemical activity.

The progress in developing AlGaN/GaN high electron mobility transistor (HEMT) structures for biological sensor applications is discussed. The studies have shown that when the gate region of the piezoelectric structures is functionalized with appropriate receptors, they are capable of sensitive detection of a range of biomolecules of interest in medical diagnosis.

Single molecule spectroelectrochemistry (SMS-EC) is used for studying the electrogenerated chemiluminescence (ECL) of nanoparticles (NPs) of a conjugated polymer, such as poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT), which is used in solar cells and organic light emitting diodes (OLEDs). The studies have shown that due to high sensitivity, low background, and high spatial and high temporal resolution of ECL, it is useful as a sensitive analytical method.

A new class of electrogenerated chemiluminescence (ECL) system is developed by using Ru-LC single crystalline nanobelts fabricated by a simple reprecipitation method. The constructed nanobelts showed an enhanced fluorescence emission and relatively strong ECL that can find potential analytical applications.

The transport properties of as-deposited and rapid thermal annealed phosphorus-doped ZnO films grown by pulsed laser deposition are analyzed. The properties of these films are used for extrapolating the behavior of the phosphorus dopant in the process-dependent creation of effective acceptor states.

A new technique, single-molecule spectroelelctrochemistry (SMS-EC), is used to study the electrochemical oxidation of the conjugated polymer poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT) at an indium tin oxide (ITO) electrode. The results have revealed both excited singlet state and ground state oxidation and have also shown that the latter process occurs with a narrow distribution of single-molecule half-wave potential values.

The performance of AlGaN/GaN heterostructure field-effect transistors (HFETs) with either uncapped surfaces or with low-temperature (LT) GaN or SiO2 or SiN(sub x) as gate insulators is reported. The result is consistent with the insulator layers providing passivation of surface states that cause the depletion of the channel layer.

The electrochemical oxidation of guanosine (Gs) and the application of scanning electrochemical microscopy (SECM) in a nanogap configuration to detect and measure the lifetime of the Gs radical cation Gs(super .+) are reported. It is concluded that the SECM in a G/C nanogap configuration is proved to be useful technique for observing short-lived electrogenerated intermediates of Gs.

The synthesis, structure, and optical properties of one-dimensional heteroepitaxial cored (Zn, Mg) O semiconductor nanowires grown by a catalyst-driven molecular beam epitaxy technique are discussed. The temperature-dependent photoluminescence shows a slight blueshift in the near band edge peak, which is attributed to a few percent Mg doping in the nanoscale ZnO core.

The electrical properties of self-assembled monolayers (SAMs) on a gold surface is explored, to address the relation between the conductane of a molecule and its electronic structure. The rectifying behavior of the electric conduction of a fresh SAM, of these molecules is explained.

Studies done on the effects of hydrogen on the electrical and optical properties of p-GaN are presented. Results indicate that hydrogen diffusion appears to be strong function of the hydrogen concentration incorporated into the material during growth.

The effects of hydrogen plasma treatment on high quality bulk n-ZnO crystals subjected at 200degree C are studied. The result is partial due to the surface damage caused by plasma exposure.