bluuebunny/crossref_metadata_2025 huggingface dataset:
In Situ Electrokinetic Preconcentrator for Conductive Biofluids
Authors: Yang Kai , Wu Jie
Published: October 2010

To detect and identify biomolecules at its infectious dose, all sensors require a relatively long time — days or even weeks — for reliable results. This delay occurs because the collection of analyte molecules onto the sensing elements depends solely on the diffusion process of those agents to a sensor. This work seeks to enhance the transport process, and thereby significantly improve a sensor’s detection capability. This work investigates an in-situ, label-free nanoparticle (e.g. protein) preconcentrator based on a new AC electrothermal effect (ACET) that can operate even in a highly conductive solution for which current methods such as dielectrophoresis, electrophresis or electroosmosis won’t function effectively. The proposed AC electrokinetic preconcentrator is expected to significantly increase the nanoparticle counts, realizing sub-femto molar detection in real time.
Particle Migration by Optical Scattering Force in Microfluidic System With Light-Absorbing Liquid
Authors: Motosuke Masahiro , Shimakawa Jun , Honami Shinji
Published: October 2010

The optical force offers the promise of being applied as noninvasive manipulation tool for microscopic objects without physical contact. The optical scattering force is predominant in the light field with parallel or gently focused beam, while the gradient force in the tightly focused one. The optical approach using the scattering force for the microfluidic system has advantages over the electric or the other methods of particle control, such as no physical contact or no need for electrode fabrication. This paper reports experimental and theoretical investigations of the potential of optical scattering force for particle control technique in a microfluidic system with light-absorbing liquid. Light-absorption of liquid induces the change of liquid properties mainly in the viscosity, which means the decrease of viscous drag for suspended particles. In the experimental system, the light source to exert the optical force was a compact diode laser with the wavelength of 635 nm. The absorption of the beam was controlled by the concentration of dye substance in a buffer solution. Polystyrene particles with the diameter of 1.9 μm were suspended in the liquid flowing in the microchannel. The particle velocity field and fluid temperature distribution were measured by the image processing with the individual particle tracking and by the temperature-sensitive fluorescent dye dissolved in the fluid, respectively. When there is no absorption of the light in the liquid, the particle velocity is linearly increased with the increase of the laser power. The calculated optical force based on the ray optics agrees with this tendency. In the case of the light-absorbing liquid, the migration speed of the particle indicates the nonlinear increase as the laser power increases. This nonlinearity is attributed to temperature dependence of the viscosity of the liquid.
Effects of the Fractal Prefactor on the Optical Properties of Fractal Soot Aggregates
Authors: Liu Fengshan , Snelling David R. , Smallwood Gregory J.
Published: October 2010

The effects of prefactor on the optical properties of numerically generated fractal soot aggregates were investigated using the numerically exact generalized multi-sphere Mie-solution method (GMM) and the approximate Rayleigh-Debye-Gans (RDG) theory. The numerically generated fractal aggregates consist of 50 to 400 primary particles of 30 nm in diameter. The considered incident laser wavelength is 266 nm. Attention is paid to the effect of prefactor on the vertical-vertical differential scattering cross section, since such quantity has often been used to infer the fractal dimension and prefactor based on the RDG formulation. The fractal prefactor affects the optical properties of the numerically generated soot aggregates through its influence on the compactness of the structure. Using GMM to calculate the optical properties of the numerically generated aggregates results in a lower aggregate absorption cross section, but a higher total scattering cross section with increasing the prefactor. The difference between the RDG results and those of GMM is primarily caused by multiple scattering and such effect is found significant, especially for the higher value of prefactor considered. The fractal dimension derived from the GMM non-dimensional differential scattering cross section agrees well with the morphological value in the case of the lower prefactor of 1.3 considered; however, the derived fractal dimension is much higher than the morphological value for fractal soot aggregates with a prefactor of 2.3. The light scattering derived prefactor is in general lower than the morphological value, especially when the morphological prefactor is higher.
Thermal and Phase Change Characteristics of Self-Assembled PAO Nanoemulsion Fluids
Authors: Xu J. J. , Liu X. , Yang B. , Tran Thanh
Published: October 2010

The strategy of adding solid particles to fluids for improving thermal conductivity has been pursued for more than one century. Here, a novel concept of using liquid nanodroplets for enhancing thermal performance has been developed and demonstrated in polyalphaolefin (PAO) nanoemulsion fluids. The PAO nanoemulsion fluids are spontaneously generated by self-assembly, and are thermodynamically stable. Their thermophysical properties, including thermal conductivity and viscosity, and impact on convective heat transfer are investigated experimentally. The thermal conductivity enhancement in these fluids is found to be moderate, but increases rapidly with increasing temperature in the measured temperature range from 35 °C to 75 °C. A very remarkable increase in convective heat transfer coefficient occurs in the nanoemulsion fluids due to the explosive vaporization at the superheat limit (i.e., spinodal states). The fluid heat transfer could be augmented through the heat of vaporization (which intuitively raises the base fluid specific heat capacity) and the fluid mixing induced by the sound waves. The development of such phase-changeable nanoemulsion fluids would open a new direction for thermal fluids studies.
Adhesin-Specific Nanomechnical Cantilever Biosensors for Detection of Microorganisms
Authors: Tzeng Tzuen-Rong J. , Cheng Yunyan R. , Saeidpourazar Reza , Aphale Siddharth Sanjeev , Jalili Nader
Published: October 2010

Considerable evidence has indicated that lectins (adhesins) on bacterial surfaces play an important role in the initiation of infection by mediating bacterial adherence to epithelial cell, especially in the gastrointestinal and urinary tracts. Many bacteria express adhesins on their surfaces in the form of specialized organelles that seek and bind to cognate receptors on the surface of mucosal cells. Some of these specific receptors have been reported and many of them are carbohydrates in nature. We have explored the use of specific carbohydrate receptors for the functionalization of nanoparticles and demonstrated their binding specificities and their ability to mediate aggregations of targeted bacteria. Based on these binding specificities, here we report the development of adhensin-specific nanomechanical cantilever (microcantilever) biosensors for the detection of their targeted microorganisms.
Effective Viscosity Measurement of CuO and ZnO Nanofluids
Authors: McCants Dale A. , Ali M. Yakut , Khan Jamil
Published: October 2010

Nanofluid has the promising potential for enhancing the heat transfer performance of conventional fluids. Several experimental and numerical attempts have been made earlier to investigate its important thermo physical properties like thermal conductivity and viscosity. The findings and results are quite disperse instead of reaching a definitive agreement. This paper presents effective viscosity measurements of CuO and ZnO nanofluids experimentally. A Brookfield viscometer model DV-I Prime with a CPE 40 cone has been used to determine the effective viscosity of nanofluids. The measurements have included the effect of volume concentration of nanoparticles and temperature. The experimental results are compared with several experimental and theoretical models available in the existing literature. From the obtained experimental results it can be concluded that the viscosity values of the above mentioned nanofluids has a tendency to increase with increase of nanoparticle concentration and follows a decreasing trend with an increase in temperature. Presented results can be used to define the above mentioned nanofluids within the experimental volume concentration range in CFD software package and hence to predict overall heat transfer performance using these nanofluids.
The Role of Ion Electrophoresis in Electroporation-Mediated Molecular Delivery
Authors: Li Jianbo , Lin Hao
Published: October 2010

Electroporation is a widely applied technique to deliver active molecules into the cellular compartment, to perform tasks such as gene therapy and directed stem cell differentiation, among many others. In this technique, an electric field transiently permeabilizes the cellular membrane to facilitate molecular exchange. While the permeabilization process is relatively well understood, the transport mechanisms for molecular delivery are still under debate. In this work, the role of ion electrophoresis in electroporation-mediated molecular delivery is investigated using numerical simulation. The Nernst-Planck equations for ionic transport in the extracellular and intracellular spaces are solved, respectively, and are coupled through a permeabilization model on the membrane. For the latter, an asymptotic Smoluchowski equation system is adopted, following the work of Krassowska and co-authors. The simulation is used to investigate the delivery of calcium ions into Chinese hamster ovary cells. The results indicate that ion electrophoresis is the dominant mode of transport in the delivery of small charged molecules. Furthermore, the achievable intracellular concentration is strongly influenced by the conductivity difference between the cytoplasm and the buffer, a phenomenon known as “field-amplified sample stacking”. The results agree qualitatively with the fluorescence measurements by Gabriel and Teissie´ (1999), and suggest a new possibility to simultaneously improve cell viability and efficiency in electroporation-mediated molecular delivery.
Measurement of the Volume Growth Rate of Single Budding Yeast
Authors: Sun Jiashu , Li Deyu , Stowers Chris , Boczko Erik
Published: October 2010

We report on measurements of the growth rate of single budding yeasts with two microfluidic devices. One device is a MOSFET-based microfluidic Coulter-type sensor, which amplifies nonlinearly the resistance modulation from the translocation of budding yeast through the sensing microchannel. By moving a budding yeast cell back and forth through the sensing channel and measuring the induced resistance pulse from the translocation of the budding yeast, the volume growth rate of a budding yeast cell can be measured over its whole cell cycle. The other microfluidic device is based on comparing the resistance of the sensing microchannel with that of a reference microchannel, which eliminates the signal drift from the electrical conductivity change of the culture media. The reference channel-based sensing scheme enables real-time measurements of the volume growth rate of a budding yeast cell sitting in the sensing microchannel over a whole cell cycle. Measurement results from both devices show that the volume growth of single budding yeast is of sigmoid shape with a slow growth rate both before the bud emergence and at the end of the cell cycle. The device could be used for other important applications such as sensing the response of kidney cells to their micro-environments.
Superhydrophobic Friction Reduction Microtextured Surfaces
Authors: Kim Tae Jin , Hidrovo Carlos H.
Published: October 2010

Superhydrophobic surfaces are surfaces with fluid contact angles larger than 150°. Superhydrophobicity can be achieved by chemically modifying the surface or introducing texturing which increases the real or effective area of the surface. In this work we focus on the latter approach. If the texturing leads to a Cassie non-wetting state, the surface can also exhibit drag reduction characteristics. Thus, for the same energy input drag reducing surfaces lead to higher flow velocities or, conversely, in order to achieve the same flow rates and velocities, drag reducing surfaces require less energy input. In order to optimize the surface topography of the superhydrophobic surface, a stratified two-phase model of flow between flat plates was developed to simulate the friction reduction characteristics of the surface as a function of varying ‘fluid to gas’ ratios. The Stokes flow equation was used to derive velocity profiles with appropriate slip/no-slip conditions within the flow. Non-dimensional formulations were used to optimize the liquid flow rate as a function of the gas layer thickness. Based on these formulations, a pressure drop reduction of 72% is achieved when the air layer height to the total channel height is 7%. The results of the theoretical model were also compared against experimental measurements of microfluidic channels with different substrate surface topographies. Two different types of silicon substrates were used: one with flat plane topography and one with a micropillar array. The substrates were irreversibly bonded to PDMS (poly-dimethylsiloxane; Dow Corning) microfluidic channel replicas and were silanized to further enhance hydrophobicity. Flow was induced using a constant pressure source and the flow rate was measured using a high-precision scale. As expected, the experimental results deviated somewhat from the expected theoretical model due to the presence of the micropillar obstruction in the air layer. It was also observed that there was a certain ‘pillar-to-channel height’ ratio that minimized the pressure drop for a given flow rate.
Cooling Performance of Nanofluids in a Microchannel Heat Sink
Authors: Wang Y. , Chung S. J. , Leonard J. P. , Cho S. K. , Phuoc T. , Soong Y. , Chyu M. K.
Published: October 2010

This paper describes an experimental study on microchannel heat sink performance where ZnO nanoparticle suspended fluids are used as coolant. The microchannel heat sink has 65 parallel microchannels branched out from an inlet reservoir and then collected into an outlet reservoir. Its fabrication process is based on the standard photolithographic microfabrication technology. A main feature of the heat sink has an array of on-chip temperature sensors on the channel bottom surface along the channel. Thus, the channel wall temperatures are directly measured. Heat transfer coefficient for the nanofluid is measured and compared with that of DI water as reference. The experiments show that the heat transfer coefficient of the ZnO nanofluid is 13% higher than that of the base fluid at the Reynolds number of 3.8, although it is comparable with that of DI water at lower Re numbers. The experiments also show that the heat transfer coefficient as well as the Nusselt number increases as the Reynolds number increases.
A Piezoelectric Micropumping Device
Authors: Ali M. Yakut , Kuang Cuifang , Khan Jamil , Wang Guiren
Published: October 2010

A dynamic micropumping device has been developed, which is based on acoustic streaming generated by a piezoelectric microtransducer actuated in d31 mode without any check valve. Piezoelectric microtransducers immersed in liquid (water) are used as actuators due to some of their unique properties such as lower noise generation and ease of miniaturization. Quantitative results of maximum local velocity are presented for different tip configuration of the same actuator for comparison. In addition, this work also demonstrates the quantitative measures of the pumping performance such as the pressure head generated as a function of different relevant parameters such as applied electrical field, AC frequency and length of the actuator.
Transient Characteristics of Pool Boiling Heat Transfer in Nanofluids
Authors: Kwark Sang M. , Kumar Ratan , Moreno Gilberto , You Seung M.
Published: October 2010

This study shows the transient characteristics of the pool boiling curves using nanofluid as the boiling fluid. This time-dependency is in sharp contrast to a unique steady-state pool boiling curve that is typically obtained for a pure fluid. Past researches on nanofluids have provided several interesting information about the thermal characteristics for this potentially promising cooling fluid. Results from these studies have shown some extraordinary critical heat flux (CHF) values and thermal conductivity enhancement that is yet to be explained by existing theories and correlations. The nature of the pool boiling curve for a nanofluid is dependent on the nanoparticle concentration in the base fluid. Higher concentration nanofluids show a perceptible degradation in the boiling heat transfer coefficient but have exhibited an enhanced CHF value (up to ∼80%) when compared to the CHF value of the base fluid (water). Another key observation has been in the significant deposition of nanoparticles on the heater surface. This fouling of the heater surface by nanoparticles is widely viewed as a main contributor that modifies the pool boiling curve of the base liquid. The deposition of the nanoparticles on the heater surface is dynamic and this in turn makes the nanofluid pool boiling curve exhibit transient characteristics.
Wetting Properties of Patterned Silicon Microchannels With Tunable Surface Energy Using Layer-by-Layer Nano Self-Assembly
Authors: Zhang Tao , Cui Tianhong
Published: October 2010

The wettability of patterned silicon microchannels with tunable surface free energy through coating hydrophilic TiO2 nanoparticles using layer-by-layer (LbL) nano self-assembly technique is presented in this paper. Wettability of microchannels is tested by measuring the contact angle of a water droplet on the substrate. The capillary rise rate is tested by measuring the front location of liquid on the silicon microchannel surface laid on a 45 degree inclined platform. It is found that the silicon microchannels with tunable surface free energy have super-hydrophilic wettability, and demonstrate powerful capillary. For the silicon microchannels 200 μm wide, the liquid front can move up 40 mm in approximately 3 second. Fourier transformed infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) reveal the generation of -OH radicals after coating TiO2 nanoparticals, verifying that the -OH radicals have a strong effect on the hydrophilicity. The super-hydrophilic patterned microchannels suggest potential applications to microfluidic systems and heat diffusion systems based on liquid surface tension.
Opto-Chemical Ring Resonator Sensor Based on Morphology Dependent Resonances for Detecting Gas Odorant
Authors: Rahman Anisur
Published: October 2010

In recent years, optical fiber technology are emerged as the most popular technology for its unique characteristics, such as free of electromagnetic interference, high precision, etc. A novel Opto-Chemical Ring Resonator (OCRR) has been presented for detecting gas odorant. The sensor is designed based on Morphology Dependent Resonances (MDR) which follows Maxwell’s electromagnetic equations. In this paper, we have presented a novel technique to integrate chemical science and optical technology by using OCRR. Optical resonances of electromagnetic wave propagations in dielectric micro-ring resonator have been developed based on asymptotic approach. The developed expression for size parameter for transverse electric wave is very simple and can be used to characterize the resonances in dielectric micro-ring resonator. Parametric studies based on developed asymptotic expression have been presented to determine the resonance frequency at particular chemical composition. Resonance frequencies will be shifted as surrounding chemical composition changes as odorant changes, i.e., MDR frequencies trapped inside the dielectric ring resonator are influenced by chemical composition of the odorant, and the OCRR sensor is designed based on this principle. Finite element simulation is used to predict the performance of the sensor and found encouraging results for odorant sensing. Parametric studies show that present study will help to develop novel OCRR sensors for micro/nano technology and biomedical applications.
Microfabricated Thermal Gradient Separator Device
Authors: Saputra  , Geelhoed P. F. , Goosen J. F. L. , Lindken R. , Westerweel J. , van Keulen F.
Published: October 2010

The design and fabrication of a microfabricated fluidic device for particle thermophoresis is presented. The ability of the device to concentrate particles by generating a huge thermal gradient is demonstrated. In contrast to other microfluidics devices which use electrokinetics or pressure driven flow, in this device no external force acts on the particles. The separator device has been fabricated in a standard silicon substrate, consisting of a 20 μm deep channel and a 600 nm thick aluminum heater integrated into the device. The device is able to create a thermal gradient of approximately 104 Km−1. To maintain a thermal gradient over a long period, special attention had to be given to the design of the integrated heater and thermal insulation of the channel. In order to deposit the aluminum heater on the side wall of a micro channel, a silicon substrate was wet etched in KOH solution, forming sloping sidewalls. The temperature difference was measured using a thermocouple mounted on the two sides of the channel walls, showing about 2 K temperature difference. Experimental studies have been conducted in order to study the motion of particles in response to the thermal gradient. Particle motions are recorded before and after turning on the heater. Using polystyrene latex particles suspended in de-ionized water, it is shown that 90% of particles are concentrated on the cold side of the channel after 300 seconds using only 1W of electrical power. Apart from its applicability to particle suspensions, this device also has a great potential for DNA molecule concentration and separation in bio-chemical analysis.
Tritium, oxygen-18, and deuterium diffusion at the Confederation Road landfill site, Sarnia, Ontario, Canada
Authors: Yanful Ernest K. , Quigley Robert M.
Published: October 2010

The isotopes 3H (tritium), 18O (oxygen-18), and 2H (deuterium), which appear to have been concentrated in the leachate at the Confederation Road landfill site, Sarnia, Ontario, Canada, are shown to have migrated into the underlying natural clay barrier by molecular diffusion. The theoretical best-fits to the observed concentration profiles, using the error function solution to the transient diffusion equation (analogous to Fick's second law), give diffusion coefficients of 13 × 10−6, 13 × 10−6, and 8.5 × 10−6 cm2/s for 18O, 2H, and 3H, respectively. Field concentration profiles for Cl− and Na+ are also presented for comparison. Diffusion coefficients obtained for Cl− and Na+ were 6.4 × 10−6 and 3.3 × 10−6 cm2/s, respectively. Tritium and chloride appear to have migrated a similar distance of ~2.0 m from the clay–waste interface, compared with only 1.2 m for Na+, which has probably been retarded by adsorption onto clay exchange sites. Oxygen-18 and deuterium appear to have migrated the furthest at ~2.3 m.The 3H profile indicates that post-1953 rainwater entered the landfill site, probably mostly in 1967 when the landfill trench was excavated. High δ18O and δ2H values, especially near the clay–waste interface, suggest mixing of 1967 rainwater with an isotopically enriched water, probably produced in the landfill either directly from enriched organic wastes such as leaves or by biodegradation processes. Key words: diffusion, landfill leachate, oxygen-18, tritium, clay barrier, chloride.
Determination of the fracture toughness of a saturated soft rock
Authors: Haberfield C. M. , Johnston I. W.
Published: October 2010

Although the literature provides a reasonable range of information concerning the fracture toughness of relatively hard rocks, there is virtually no data for saturated soft rocks of uniaxial compressive strengths less than about 10 MPa. To gain some insight into the plane strain fracture toughness of such a soft rock for use in the numerical modelling of crack propagation during pressuremeter testing, a large number of laboratory tests were conducted. The material used in these tests was a synthetic soft rock that modelled soft mudstone rocks reasonably accurately. This paper describes the test techniques adopted and the results obtained. The variation of fracture toughness with loading rate and with size and shape of the test specimens is presented and discussed. On the basis of these results, guidelines are suggested for the determination of plane strain fracture toughness of a soft rock. Key words: fracture mechanics, fracture toughness, laboratory testing, soft rock, weak rock.
Laboratory investigations on the lime stabilization of sensitive clays: shear strength development
Authors: Locat Jacques , Bérubé Marc-André , Choquette Marc
Published: October 2010

A laboratory investigation on the quicklime stabilization of sensitive clays has shown that, even at a water content above the liquid limit, significant strength increase can be obtained if enough time and lime are provided. The understanding of strength development is based on the recognition of physical bridging between soil particles, as in a cementation process. The physical and mechanical significance of lime stabilization is described by means of conceptual models. The better the mixing, the better the dispersion and the diffusion of lime and, consequently, the stabilization process. It has been found that the relationship between water content and strength, at a given time, follows a power law that makes possible the establishment of laboratory charts for lime stabilization of such clays. Key words: quicklime stabilization, sensitive clays, cementation, cohesion, shear strength, microstructure, conceptual model, laboratory charts.
Seismic response and design for structures located on soft clay sites
Authors: Heidebrecht A. C. , Henderson P. , Naumoski N. , Pappin J. W.
Published: October 2010

Results are presented for 3 soft clay sites forming part of a larger response study of 11 soil sites subjected to earthquakes of varying intensity and frequency content. The results are presented in the form of spectral ratios (surface to rock), base shear coefficients, and foundation factors. They indicate that large amplifications can be expected at structural periods close to the site period. Comparisons are made with the National Building Code of Canada (NBCC) 1990 provisions for base shear coefficients and foundation factors. These show that the NBCC provisions are adequate when the excitation is low or medium period in nature. For high-period excitation of low intensity, high amplifications that exceed the code provisions are produced. Key words: seismic, design, clay, soft, site, response, spectra, amplification, base, shear.
A statistical evaluation of some engineering properties of eastern Canadian clays
Authors: Windisch Étienne J. , Yong Raymond N.
Published: October 2010

Statistics for data collected on eastern Canadian clays (Champlain, Goldthwait, Tyrrell, and Laflamme marine clays and Barlow–Ojibway lacustrine clays) are computed and analyzed. These clays are divided into three groups: eastern Canadian marine clays, Champlain clays (as an important part of the first group), and Barlow–Ojibway lacustrine clays. The analysis reveals significant differences between eastern Canadian clays and Scandinavian clays. Some relationships proposed in the literature and based on plasticity index, liquidity index, and plastic limit are found to be inapplicable to eastern Canadian clays. On the basis of a proposed method for estimating the undrained shear strength of normally consolidated eastern Canadian marine clays, the overconsolidation ratio is found to be equal to the ratio of the in situ undrained shear strength to the estimated normally consolidated undrained shear strength. Key words: undrained shear strength, plasticity index, liquidity index, plastic limit, statistical evaluation, over-consolidation ratio, lacustrian clays.
RESISTANCE IN SUPERCONDUCTORS
Authors: Halperin Bertrand I. , Refael Gil , Demler Eugene
Published: October 2010

In this pedagogical review, we discuss how electrical resistance can arise in superconductors. Starting with the idea of the superconducting order parameter as a condensate wave function, we introduce vortices as topological excitations with quantized phase winding, and we show how phase slips occur when vortices cross the sample. Superconductors exhibit non-zero electrical resistance under circumstances where phase slips occur at a finite rate. For one-dimensional superconductors or Josephson junctions, phase slips can occur at isolated points in space-time. Phase slip rates may be controlled by thermal activation over a free-energy barrier, or in some circumstances, at low temperatures, by quantum tunneling through a barrier. We present an overview of several phenomena involving vortices that have direct implications for the electrical resistance of superconductors, including the Berezinskii–Kosterlitz–Thouless transition for vortex-proliferation in thin films, and the effects of vortex pinning in bulk type II superconductors on the nonlinear resistivity of these materials in an applied magnetic field. We discuss how quantum fluctuations can cause phase slips and review the non-trivial role of dissipation on such fluctuations. We present a basic picture of the superconductor-to-insulator quantum phase transitions in films, wires, and Josephson junctions. We point out related problems in superfluid helium films and systems of ultra-cold trapped atoms. While our emphasis is on theoretical concepts, we also briefly describe experimental results, and we underline some of the open questions.
SUPERCONDUCTOR-INSULATOR TRANSITIONS
Authors: Goldman A. M.
Published: October 2010

Superconductor-insulator transitions, especially in thin films, can provide the simplest examples of the continuous quantum phase transition paradigm. Quantum phase transitions differ from thermal phase transitions in that they occur at zero temperature when the ground state of a system is changed in response to a variation of an external parameter of the Hamiltonian. In the example of the superconductor-insulator transition, this control parameter could be the parallel or perpendicular magnetic field, disorder, or charge density. Quantum phase transitions are studied through measurements at nonzero temperature of physical behaviors influenced by the quantum fluctuations associated with the transition. This review will focus on experimental aspects of superconductor-insulator transition in disordered films that are effectively two-dimensional. In particular, the evidence for quantum critical behavior in the various types of transitions will be presented. The various theoretical scenarios for the transitions will also be discussed along with the extent to which they are supported by experiment. Open questions relating to the nature of the very puzzling insulating regime and whether there are many different types of superconductor-insulator transitions will be presented. Although this research area is more than 20 years old, rather central issues are not resolved.
THE EVOLUTION OF HIGH-TEMPERATURE SUPERCONDUCTIVITY: THEORY PERSPECTIVE
Authors: Abrahams Elihu
Published: October 2010

Theoretical developments concerning the high transition temperature cuprate superconductors are reviewed.
BEST CONSTANTS IN NORMS OF RETARDED WICK PRODUCTS
Authors: STAN AUREL I.
Published: October 2010

We find the best constant c(m, n, r), such that the inequality: [Formula: see text] holds for all polynomials f and g of degree at most m and n, respectively, where X is a normally distributed random vector, ⋄r denotes the r-retarded Wick product and ‖⋅‖ the L2-norm.
ALIGNMENT AND DEFORMATION OF LIPID BILAYER DOMAINS IN VESICLES ADHERING TO MICROSTRUCTURED SUBSTRATES
Authors: STÖGBAUER T. , HENNIG M. , RÄDLER J. O.
Published: October 2010

In heterogeneous lipid membranes, the lateral organization is coupled to local curvature as the membrane bending energies depend on composition. We investigate phase-separated vesicles of ternary lipid composition in contact with structured surfaces, where the distinct elastic properties of the Lo and Ld phases come into play. We show that fused silica substrates with microstructured grooves induce sorting, alignment and deformation of Lo domains in adhering vesicles. The same phenomenon is observed on flat, chemically modified substrates with alternating stripes of rough and smooth regions. In both cases it is the Lo phase which accumulates over the smooth substrate and membrane-spanned groove regions respectively. Deformation of Lo domains occurs when domain diameters grow beyond the width of the microstructured stripes. Domain alignment was also observed in binary membranes featuring gel and fluid phase coexistence showing the generic character of domain sorting on microstructured surfaces.
A COMPREHENSIVE TISSUE PROPERTIES DATABASE PROVIDED FOR THE THERMAL ASSESSMENT OF A HUMAN AT REST
Authors: MCINTOSH ROBERT L. , ANDERSON VITAS
Published: October 2010

Accurate numerical calculation of the thermal profile in humans requires reliable estimates of the following five tissue properties: specific heat capacity (c), thermal conductivity (k), blood perfusion rates (m), metabolic heat production (A0), and density (ρ). A sixth property, water content (w, as a %), can also be used to estimate c and k. To date, researchers have used various and inconsistent estimates of these parameters, which hinders comparison of the corresponding results. In an effort to standardize and improve the accuracy of these parameters for future studies, we have documented over 150 key papers and books and developed a database of the six thermal properties listed above for 43 human tissues. For each tissue and each property the following were obtained: the average value, the number of source values, the minimum and maximum of source values, and the reference for each source value. A key premise for the development of the database was to only use references that provided the original measurements. This database is offered for use by the biological thermal modeling community to help improve the accuracy and consistency of thermal modeling results.
Changing Patterns of H6 Influenza Viruses in Hong Kong Poultry Markets
Authors: Ozaki Hiroichi , Guan Yi , Peiris Malik , Webster Robert , Webby Richard
Published: October 2010

Until 2001, H6N1 influenza viruses in the Hong Kong bird markets were represented by a single stable A/teal/Hong Kong/W312/97-like lineage. Beginning in 2001, despite a reduction in overall prevalence, an increase was observed in the number of H6 viruses isolated from chickens and other hosts. To assess any changes in H6 viruses, we characterized 18 H6 viruses isolated in the Hong Kong bird markets from 2001 to 2003. Experimental data showed that the 2003 H6 viruses had similar infectivity for chickens as did A/teal/HK/W312/97, and they were unable to transmit. Although all hemagglutinin genes were closely related to A/teal/HK/W312/97, 7 isolates were reassortant viruses containing similar gene segments of co-circulating H9N2 or H5N1 viruses. The receptor specificity was different from that of A/teal/Hong Kong/W312/97. Interestingly, similar observations have been documented in H9N2 viruses in Hong Kong. This evolution strongly suggests that some change in the ecology of influenza in the region selected for these changes. Taken together, these findings suggest that the H6 influenza viruses isolated in the Hong Kong markets are not well adapted to chickens and that the likely continued source of these viruses are other “minor” poultry species in which they are undergoing genetic and biologic evolution.
No-Needle Jet Intradermal Aminolevulinic Acid Photodynamic Therapy for Recurrent Nodular Basal Cell Carcinoma of the Nose: A Case Report
Authors: Barolet Daniel , Boucher Annie
Published: October 2010

Photodynamic therapy (PDT) with aminolevulinic acid (ALA) to treat nodular basal cell carcinoma (BCC) has been shown to be beneficial. The success rate of ALA-PDT in the treatment of nodular BCC is dependent on optimal penetration of the photosensitizing agent and subsequent PpIX production. To enhance topical delivery of drugs intradermally, a needleless jet injection (NLJI), which employs a high-speed jet to puncture the skin without the side effects of needles, was used in one patient with recurrent BCC of the nose. Photoactivation was then performed using red light emitting diode [CW@ λ630 nm, irradiance 50 mW/cm2, total fluence 51 J/cm2] for 17 minutes. Excellent cosmesis was obtained. Aside from mild crusting present for six days, no other adverse signs were noted. Clinically, there was no recurrent lesion up two years postintervention. Additional studies in larger samples of subjects are needed to further evaluate this promising technique.
Introduction of Human Papillomavirus Vaccination in Belgium, Luxembourg and the Netherlands
Authors: Arbyn M. , Simoens C. , Van Damme P. , Scharpantgen A. , Meijer C.J.L.M. , Beutels P.
Published: October 2010

Aims: To document progress with human papillomavirus (HPV) vaccine introduction in three closely related European countries, one with organized (the Netherlands) and two with opportunistic cervical cancer screening (Belgium and Luxembourg). Methods: Experts involved in cervical cancer screening and national immunization programs from the three countries were contacted to provide information on the decision-making process concerning the introduction of HPV vaccine. Sales statistics were obtained from Intercontinental Marketing Services. Results: Advisory boards in all three countries advised organized HPV vaccination of girls of 12 years with variable catch-up policies. In Belgium, the national health authority partially reimburses the HPV vaccine for girls of 12–15 years (recently extended until 18 years). In Luxembourg, 12-year-old girls are invited for free vaccination, but the HPV vaccine is also free of charge for female adolescents of 13–17 years. The number of vaccines reimbursed in Belgium in December 2007 to May 2008 corresponds with the amount required to fully vaccinate 29% of the female population aged 12–15 years. In Luxembourg, between March and November 2008, the immunization program delivered a quantity of HPV vaccines which theoretically covered 29% of females aged 12–17 years. In the Netherlands, nationwide HPV vaccination of girls of 12 years will start in September 2009. The sales of HPV vaccines (all ages combined) were by far the lowest in the Netherlands. Conclusion: Up to the end of 2008, HPV vaccination efforts reached less than a third of the target population in Belgium and Luxembourg. If the latest trend continues, the current policy is expected to reach to most half of the target population. Well-planned introduction of vaccination combined with an organized screening program and active surveillance are crucial for the program to achieve and monitor its desired aims. Such surveillance should include linkage between vaccination, screening and cancer registries.
Why Consider Human Papillomavirus Vaccination in Older Women?
Authors: Poppe W.A. , Simon P.H. , De Ridder M.R.
Published: October 2010

Preventive human papillomavirus (HPV) L1 vaccines are safe and efficient to prevent infection and lesions of vaccine- specific HPV types in women from 15 to 26 years, but also in older age groups. Clearly, public health funds are to be spent to organize programs for vaccination of young adolescents. Immunobridging studies and clinical trials have shown that HPV vaccines generate significantly higher plasma antibodies than following natural infections in women up to 55 years and prevent up to 90.5% (95% CI 73.7–97.5) vaccine-specific HPV infections and lesions in women aged 24–45 years who are HPV DNA-negative at the time of vaccination. However, data from clinical trials with HPV L1 vaccines in older women (older than 25 years) are still scarce compared to the amount of evidence from trials in women younger than 26 years. Information from large population-based studies indicates that older women remain at risk of infection by high-risk HPV and the risk of persistent high-risk HPV infection is significantly higher than in young women, leading to a higher risk of progressing disease and carcinoma. The natural history of HPV infection remains enigmatic as we do not know if the immune mechanisms that clear the HPV infection offer prolonged protection. On the contrary, some data indicate that seroconversion after a natural infection only partially protects against re-infection. Given the large proportions of adult men and women that change sexual partners, the protective effects of HPV L1 vaccines may offer an extra benefit against HPV-related genital diseases within a much shorter time period than after vaccination of prepubertal adolescents.
Management of Aerobic Vaginitis
Authors: Tempera Gianna , Furneri Pio Maria
Published: October 2010

Aerobic vaginitis is a new nonclassifiable pathology that is neither specific vaginitis nor bacterial vaginosis. The diversity of this microbiological peculiarity could also explain several therapeutic failures when patients were treated for infections identified as bacterial vaginosis. The diagnosis ‘aerobic vaginitis’ is essentially based on microscopic examinations using a phase-contrast microscope (at ×400 magnification). The therapeutic choice for ‘aerobic vaginitis’ should take into consideration an antibiotic characterized by an intrinsic activity against the majority of bacteria of fecal origin, bactericidal effect and poor/absent interference with the vaginal microbiota. Regarding the therapy for aerobic vaginitis when antimicrobial agents are prescribed, not only the antimicrobial spectrum but also the presumed ecological disturbance on the anaerobic and aerobic vaginal and rectal microbiota should be taken into a consideration. Because of their very low impact on the vaginal microbiota, kanamycin or quinolones are to be considered a good choice for therapy.
Gardnerella Biofilm Involves Females and Males and Is Transmitted Sexually
Authors: Swidsinski Alexander , Doerffel Yvonne , Loening-Baucke Vera , Swidsinski Sonja , Verstraelen Hans , Vaneechoutte Mario , Lemm Vesna , Schilling Johannes , Mendling Werner
Published: October 2010

Objective: To study the incidence and distribution of adherent Gardnerella vaginalis. Methods: Bacteria adherent to desquamated epithelial cells in the urine were detected using fluorescence in situ hybridization (FISH). Urine from patients with bacterial vaginosis (BV, n = 20), their partners (n = 10) and different control populations (n = 344) including pregnant women and their partners, randomly selected populations of hospitalized man, women and children as also healthy controls was investigated. Results:Gardnerella was found in two different forms: cohesive and dispersed. In the cohesive form, Gardnerella were attached to the epithelial cells in groups of highly concentrated bacteria. In the dispersed form, solitary Gardnerella were intermixed with other bacterial groups. Cohesive Gardnerella was present in all patients with proven BV and their partners, in 7% of men and 13% of women hospitalized for reasons other than BV, in 16% of pregnant women and 12% of their male partners, and in none of the healthy laboratory staff or children. In sexual partners, occurrence of cohesive Gardnerella was clearly linked. Dispersed Gardnerella were found in 10–18% of randomly selected females, 3–4% of males and 10% of children and not sexually linked. In daily longitudinal investigations over 4 weeks no transition between cohesive and dispersed Gardnerella and vice versa was observed. Transmission of a cohesive Gardnerella strain could be followed retrospectively over 15 years using molecular genetic methods. Conclusions: Cohesive Gardnerella biofilm is a distinct, clearly definable entity which involves both genders and is sexually transmitted. The correct name distinguishing it from symptom-defined conditions like BV should be gardnerellosis and for the bacterium Gardnerella genitalis.
Effect of Lyophilized Lactobacilli and 0.03 mg Estriol (Gynoflor®) on Vaginitis and Vaginosis with Disrupted Vaginal Microflora: A Multicenter, Randomized, Single-Blind, Active-Controlled Pilot Study
Authors: Donders G.G.G. , Van Bulck B. , Van de Walle P. , Kaiser R.R. , Pohlig G. , Gonser S. , Graf F.
Published: October 2010

Objectives: To evaluate the efficacy of lyophilized lactobacilli in combination with 0.03 mg estriol when compared to metronidazole in the treatment of bacterial vaginal infections. Setting: Multicenter, randomized, single-blind, active-controlled pilot study in 3 independent gynecological practices in Belgium. Methods: Forty-six, 18- to 50-year-old premenopausal women with a disrupted vaginal flora due to a bacterial vaginal infection (bacterial vaginosis, aerobic vaginitis) were included, provided that fresh phase-contrast microscopy of the vaginal fluid showed lactobacillary flora grade 2B or 3. Patients were given a blinded box with either 12 vaginal tablets of Gynoflor® (study medication) or 6 vaginal suppositories containing 500 mg metronidazole (control medication). Eight efficacy variables were studied to assess the status of the vaginal flora at entry, 3–7 days (control 1), 4–6 (control 2) weeks and 4 months after the end of therapy. Results: At control 1, the combined variables equally improved in the lactobacilli group as in the metronidazole group. At control 2, the lactobacillus preparation showed slightly inferior results when compared to metronidazole. At 4 months, this analysis could not be performed due to low numbers, but analysis of recurrence rate and extra medication needed was not different between both groups. Conclusion: Lyophilized lactobacilli in combination with low-dose estriol are equivalent to metronidazole in the short-term treatment of bacterial vaginal infections, but have less effect after 1 month. Further studies are required to evaluate the long-term efficacy of lactobacilli when applied repeatedly.