bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface modification of gold–carbon nanotube nanohybrids under the influence of near-infrared laser exposure
Authors: Schrand Amanda M. , Stacy Bradley M. , Hussain Saber M. , Fan Maomian , Speltz Jared , Payne Sarah , Dosser Larry
Published: May 2012

The development of multifunctional hybrid nanostructures that can be remotely activated is an attractive strategy for a diverse range of applications ranging from electronics, cancer therapeutics, and drug delivery platforms to sophisticated biosensors. In this study, the authors examined the systematic capture of biomolecular targets onto single-walled carbon nanotubes (SWNTs), site-specific labeling with gold nanoparticles (GNPs) of three different sizes (10, 30, 60 nm), and the subsequent effects upon exposure to 1064 nm near-infrared (NIR) laser irradiation. The authors demonstrate that the SWNT-GNP hybrids containing the smallest GNPs experience greater heating and subsequent GNP release upon NIR laser irradiation compared to SWNT surfaces modified with larger 60 nm GNPs. The authors hypothesize that the greater attachment efficiency of the smaller GNPs to the biomolecules allows increased heat transduction. Therefore, it is possible to physically modify the surface of hybrid nanostructures remotely via NIR laser irradiation. It is anticipated that targeted NIR strategies will benefit from the robustness of novel material combinations, such as SWNT-GNP hybrid nanostructures, as well as interchangeable biomolecular ligands.
Laboratory investigations of irradiated acetonitrile-containing ices on an interstellar dust analog
Authors: Abdulgalil Ali G. M. , Marchione Demian , Rosu-Finsen Alexander , Collings Mark P. , McCoustra Martin. R. S.
Published: May 2012

Reflection-absorption infrared spectroscopy is used to study the impact of low-energy electron irradiation of acetonitrile-containing ices, under conditions close to those in the dense star-forming regions in the interstellar medium. Both the incident electron energy and the surface coverage were varied. The experiments reveal that solid acetonitrile is desorbed from its ultrathin solid films with a cross section of the order of 10−17 cm2. Evidence is presented for a significantly larger desorption cross section for acetonitrile molecules at the water–ice interface, similar to that previously observed for the benzene–water system.
Highly efficient and long life metal–insulator–metal cathodes
Authors: Kusunoki Toshiaki , Suzuki Mutsumi , Sagawa Masakazu , Mikami Yoshiro , Nishimura Etsuko , Ikeda Mitsuharu , Hirano Tatsumi , Tsuji Kazutaka
Published: May 2012

The authors improved the emission efficiency and lifetime of metal–insulator–metal cathodes. The drift of the diode current was suppressed by using a thinner tunneling insulator and a lower diode voltage. The cathode with a 7.9-nm-thick tunneling insulator kept the diode current stable at 0.5 A/cm2 for more than 20 000 h, although the initial emission efficiency declined from 2% to less than 0.5%, and the emission current drift increased. The decreased emission efficiency could be enhanced to more than 3% by mixing CsHCO3 into an Au/Pt/Ir multilayer top electrode.
Influence of gamma irradiation on the C-V characteristics of the Al/SiNx/Si MIS capacitors
Authors: Tugay Evrin , Yilmaz Ercan , Turan Rasit
Published: May 2012

The authors studied effects of gamma radiation on the electrical properties of the MOS capacitor made on SiNx thin films with thickness of 100 nm deposited on p-type (100) silicon wafer using plasma-enhanced chemical vapor deposition method. The authors investigated the chemical bonds and their densities inside the films using Fourier transform infrared (FTIR) spectroscopy. The as-deposited and annealed samples with Al/SiNx/Si structure as metal–insulator–semiconductor (MIS) capacitors were exposed to a 60-Co gamma radiation source with a dose rate of 0.015 Gy/S. The authors performed capacitance-voltage measurements at frequencies 10, 100, and 1000 kHz before and after radiation exposure with doses of up to 40 Gy. It was found that before gamma irradiation compared with as-deposited sample, the annealed samples exhibit less negative flatband voltages (Vfb) shift. This indicates the relative reduction in positive charge in the SiNx:H samples. After gamma irradiation, for all samples a negative shift has been observed in Vfb, being more pronounced in the samples annealed at 700 °C. The more striking feature is that the amount of shift does not change by increasing radiation dose after first irradiation, in which we attributed what to the radiation hardening in Al/SiNx/Si MIS capacitors.
Fine Specificity of Plasmodium vivax Duffy Binding Protein Binding Engagement of the Duffy Antigen on Human Erythrocytes
Authors: Siddiqui Asim A. , Xainli Jia , Schloegel Jesse , Carias Lenore , Ntumngia Francis , Shoham Menachem , Casey Joanne L. , Foley Michael , Adams John H. , King Christopher L.
Published: May 2012

Plasmodium vivax
invasion of human erythrocytes requires interaction of the
P. vivax
Duffy binding protein (PvDBP) with its host receptor, the Duffy antigen (Fy) on the erythrocyte surface. Consequently, PvDBP is a leading vaccine candidate. The binding domain of PvDBP lies in a cysteine-rich portion of the molecule called region II (PvDBPII). PvDBPII contains three distinct subdomains based upon intramolecular disulfide bonding patterns. Subdomain 2 (SD2) is highly polymorphic and is thought to contain many key residues for binding to Fy, while SD1 and SD3 are comparatively conserved and their role in Fy binding is not well understood. To examine the relative contributions of the different subdomains to binding to Fy and their abilities to elicit strain-transcending binding-inhibitory antibodies, we evaluated recombinant proteins from SD1+2, SD2, SD3, and SD3+, which includes 24 residues of SD2. All of the recombinant subdomains, except for SD2, bound variably to human erythrocytes, with constructs containing SD3 showing the best binding. Antisera raised in laboratory animals against SD3, SD3+, and SD2+3 inhibited the binding of full-length PvDBPII, which is strain transcending, whereas antisera generated to SD1+2 and SD2 failed to generate blocking antibodies. All of the murine monoclonal antibodies generated to full-length PvDBPII that had significant binding-inhibitory activity recognized only SD3. Thus, SD3 binds Fy and elicits blocking antibodies, indicating that it contains residues critical to Fy binding that could be the basis of a strain-transcending candidate vaccine against
P. vivax
.
Designing and delivering a hypnotherapy service for irritable bowel syndrome in primary care
Authors: Bremner Helen
Published: May 2012

Evidence-based guidelines recommend hypnotherapy as a treatment option for intractable irritable bowel syndrome (IBS). However, few National Health Service (NHS) hypnotherapy services are in place. We report the experiences and results from the only NHS-funded primary care service for IBS hypnotherapy in England (as identified by a telephone audit of 151 Primary Care Trusts (PCT) in England in February 2011). The service was delivered by a full-time nurse hypnotherapist, commissioned and funded by a PCT. In 18 months, 119 patients have been seen. Validated scoring tools showed improvement in quality of life and symptom severity scores, with improvement in all domains following therapy. This case study illustrates both the clinical effectiveness of hypnotherapy in the treatment of IBS delivered by a nurse hypnotherapist and some of the challenges faced when setting up this service. This paper summarises aspects of a model of care that could act as a template for service providers wishing to deliver hypnotherapy for IBS.
Gene–environment interactions in inflammatory bowel disease: microbiota and genes
Authors: Aldhous Marian C
Published: May 2012

A recent research workshop gave an update on the genetics of the inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis. This mini-review summarises the updates of the gene–environmental interactions, especially those outlining the contribution of the gut microbiota to the pathogenesis of IBD.
KNEADINGS, SYMBOLIC DYNAMICS AND PAINTING LORENZ CHAOS
Authors: BARRIO ROBERTO , SHILNIKOV ANDREY , SHILNIKOV LEONID
Published: May 2012

A new computational technique based on the symbolic description utilizing kneading invariants is proposed, and verified for explorations of dynamical and parametric chaos in a few exemplary systems with the Lorenz attractor. The technique allows for uncovering the stunning complexity and universality of bi-parametric structures and detects their organizing centers — codimension-two T-points and separating saddles in the kneading-based scans of the iconic Lorenz equation from hydrodynamics, a normal model from mathematics, and a laser model from nonlinear optics.
NEURONS ARE POISED NEAR THE EDGE OF CHAOS
Authors: CHUA LEON , SBITNEV VALERY , KIM HYONGSUK
Published: May 2012

This paper shows the action potential (spikes) generated from the Hodgkin–Huxley equations emerges near the edge of chaos consisting of a tiny subset of the locally active regime of the HH equations. The main result proves that the eigenvalues of the 4 × 4 Jacobian matrix associated with the mathematically intractable system of four nonlinear differential equations are identical to the zeros of a scalar complexity function from complexity theory. Moreover, we show the loci of a pair of complex-conjugate zeros migrate continuously as a function of an externally applied DC current excitation emulating the net synaptic excitation current input to the neuron. In particular, the pair of complex-conjugate zeros move from a subcritical Hopf bifurcation point at low excitation current to a super-critical Hopf bifurcation point at high excitation current. The spikes are generated as the excitation current approaches the vicinity of the edge of chaos, which leads to the onset of the subcritical Hopf bifurcation regime. It follows from this in-depth qualitative analysis that local activity is the origin of spikes.
DISPERSION RELATIONS OF A PERIODIC ARRAY OF FLUID-FILLED HOLES EMBEDDED IN AN ELASTIC SOLID
Authors: LI JIAN-BAO , WANG YUE-SHENG , ZHANG CHUANZENG
Published: May 2012

Dispersive properties of elastic waves in a periodic composite with an array of fluid-filled holes are studied in this paper. A finite element method taking into account of the fluid–solid interaction is developed to calculate the dispersion curves. The finite element formulation is presented for one unit cell by taking advantage of the periodicity of the structures and the Bloch theorem. After dividing the equations in the real and imaginary parts, the numerical computation is performed by using the standard finite element code ABAQUS. As numerical examples, some typical two- and three-dimensional systems with circular or spherical holes filled with air, water or mercury are considered in detail. The method can yield precise results with fast convergence for all cases from very low-density fluids to very high-density fluids.
THREE-DIMENSIONAL SOUND PROPAGATION MODELS USING THE PARABOLIC-EQUATION APPROXIMATION AND THE SPLIT-STEP FOURIER METHOD
Authors: LIN YING-TSONG , DUDA TIMOTHY F. , NEWHALL ARTHUR E.
Published: May 2012

The split-step Fourier method is used in three-dimensional parabolic-equation (PE) models to compute underwater sound propagation in one direction (i.e. forward). The method is implemented in both Cartesian (x, y, z) and cylindrical (r, θ, z) coordinate systems, with forward defined as along x and radial coordinate r, respectively. The Cartesian model has uniform resolution throughout the domain, and has errors that increase with azimuthal angle from the x axis. The cylindrical model has consistent validity in each azimuthal direction, but a fixed cylindrical grid of radials cannot produce uniform resolution. Two different methods to achieve more uniform resolution in the cylindrical PE model are presented. One of the methods is to increase the grid points in azimuth, as a function of r, according to nonaliased sampling theory. The other is to make use of a fixed arc-length grid. In addition, a point-source starter is derived for the three-dimensional Cartesian PE model. Results from idealized seamount and slope calculations are shown to compare and verify the performance of the three methods.
LIMITING PROPERTIES OF LÉVY PROCESSES IN SYMMETRIC SPACES OF NONCOMPACT TYPE
Authors: LIAO MING , WANG LONGMIN
Published: May 2012

We study the large time limiting properties of a Lévy process in a symmetric space of noncompact type, both pathwise and in terms of distribution.
A NEW APPROACH FOR ASSESSMENT OF PULSE WAVE VELOCITY AT RADIAL ARTERY IN YOUNG AND MIDDLE-AGED HEALTHY HUMANS
Authors: ZHANG YONG-LIANG , MA ZU-CHANG , LUNG CHI-WEN , SUN YI-NING , LI XIN-HUI
Published: May 2012

Pulse wave velocity (PWV), based on two-site measurement, is a well-known predictor of arterial stiffness. Interest focused increasingly on simplifying the PWV measurement results in attempts at determining it at a single site. We aimed to validate a new tonometric method (IIM-2010A) for assessment of PWV at radial artery in healthy subjects <65 years of age. PWV measurements were performed in 46 healthy adults (25 men and 21 women) aged 21–65 years (39.6 ± 15.5 years) using Complior device and IIM-2010A respectively. In a subgroup of 21 humans, the measurements were repeated after 1 week using IIM-2010A with the same protocol. There was a strong correlation between PWV obtained by IIM-2010A and PWV obtained by Complior, as well as between pulse transit time (PTT) measurements (r = 0.79 and r = 0.85, respectively, P < 0.01 for both). Although PTT was significantly lower measured by IIM-2010A, no significant difference was found in PWV. The mean difference of PWV with SD was -0.1 ± 1.2 m/s between two repeated measurements at intervals of 1 week. Bland–Altman's plot indicated no trend for the reproducibility of measurements to vary with their underlying mean value. Intraclass correlation coefficient (= 0.87) confirmed this excellent week-to-week reproducibility of PWV. The method provides a simple, easily-obtainable, and reproducible measurement of PWV in young and middle-aged subjects, and has potential to detect premature arterial aging for the management of primary prevention.
Electroluminescence and photoluminescence in porphyrin derived compounds in a new polymeric PVK:PBD host
Authors: Razavi Hossein , Mohajerani Ezzedin , Safari Naser , Shahroosvand Hashem , Khabbazi Amir
Published: May 2012

The electroluminescence (EL) and photoluminescence (PL) of five porphyrin compounds have been investigated. Each of the porphyrin derivations were doped with different concentrations in a PVK(polyvinyl carbazole):PBD(2-(4-biphenyl)-5-(4-t-butyl-phenyl)-1,3,4-oxadiazole) blend as the host. The effect of the porphyrin type on the variation of the peak wavelength, FWHM (wavelength peak of emission spectra), CIE (1931 color Space standard) Coordinate, I–V characteristics have been studied in the same host, and the PL and EL spectra for all porphyrins were compared. It has been shown that the electrical and optical properties of the fabricated device can be controlled by altering the structure and concentration of the dopant.
Porphyrin aggregates in the form of nanofibers and their unusual aggregation induced emission
Authors: Pandey Rakesh K. , Chitgupi U. , Lakshminarayanan V.
Published: May 2012

We present here the simple procedure for synthesizing elongated fibers like porphyrin aggregates. Usually whenever the aggregation in dye molecules takes place the emission always tends to quench. In this work we explore and discuss the unusual enhanced emission property of these aggregates. The nanofibers of porphyrin were characterized with the help of atomic force microscopy and UV-vis spectroscopy whereas photoluminescence spectroscopy was used to check their emission property.
In-situ Spectroscopic Ellipsometry of the Cu Deposition Process from Supercritical Fluids: Evidence of an Abnormal Surface Layer Formation
Authors: Sasaki Takuya , Tamegai Yukihiro , Ueno Takahiro , Watanabe Mitsuhiro , Jin Lianhua , Kondoh Eiichi
Published: May 2012

In this paper, we report in-situ spectroscopic ellipsometry of Cu deposition from supercritical carbon dioxide fluids. The motivations of this work were 1) to perform a detailed observation of Cu growth with precision optical metrology, 2) to study substrate dependence on Cu growth, particularly for Ru and TiN substrates in the present case, and 3) to demonstrate the possibility and usefulness of ellipsometry for diagnosing supercritical fluid processing. The Cu deposition was carried out through hydrogen reduction of a Cu β-diketonate precursor at 160–180 °C. During growth, a very large deviation of ellipsometric parameters (Ψ and Δ) from a single-layer model prediction was observed; this deviation was much larger than that expected from island formation which has been frequently reported in in-situ ellipsometric observation of the vapor growth of thin films. From model analyses, it was found that an abnormal dielectric layer having a high refractive index and a thickness of 10–50 nm is present on the growing Cu surface. The refractive index of this layer was (1.5–2) + (0.2–0.3)i; and from this, we concluded that this layer is the condensed precursor. The condensed layer develops prior to Cu nucleation. As for the substrate dependence on Cu growth, both layers develop faster on Ru than on TiN. This corresponds to the fact that chemisorption occurs more easily on Ru. The deposition kinetics under the presence of the condensed layer are also discussed.
Current Induced Grain Growth of Electroplated Copper Film
Authors: Razak Liyana , Yamaguchi Takamasa , Akahori Seishi , Hashimoto Hideki , Ueno Kazuyoshi
Published: May 2012

To study the potential of electric current stress in enhancing the grain growth of electroplated copper (Cu) films, the behavior of Cu grain growth at different additive concentrations with current stress applied was investigated. It was found that the lower poly(ethylene glycol) (PEG) concentration alone slightly enhanced the grain growth, but the higher sulfopropyl sulfonate (SPS) concentration was favored in assisting larger grain growth in the current induced grain growth. The effect of current density and temperature on the current induced grain growth have also been studied, and it was found that current stress with a high current density and at a high temperature promotes a larger grain size and anisotropic grain growth along the current direction.
Barrier Integrity of Electroless Diffusion Barriers and Organosilane Monolayer against Copper Diffusion under Bias Temperature Stress
Authors: Mitsumori Akiyoshi , Fujishima Shota , Ueno Kazuyoshi
Published: May 2012

Barrier integrity of electroless NiB and CoWP/NiB thin layers against copper (Cu) diffusion was evaluated by time-dependent dielectric breakdown (TDDB) under bias temperature stress (BTS) using metal oxide semiconductor (MOS) test structures. The BTS tests were carried out also for an approximately 2.2-nm-thick organosilane monolayer (OSML), which has been used as the underlayer of the electroless barrier layers (EBLs). It was found that the barrier integrity of the EBLs was NiB 40 nm > NiB 10 nm > CoWP/NiB 40 nm = CoWP/NiB 10 nm in this order. The field acceleration parameter of the TDDB lifetime was almost the same for all EBLs. Initial failures and wide lifetime distributions were observed for CoWP/NiB when the NiB catalyst layer for CoWP was not thick enough, which is considered to be due to the large surface roughness. In addition, the OSML was found to have some barrier properties. Although the reliability of OSML was inferior to electroless NiB and CoWP/NiB barrier layers, it is considered that the barrier integrity of the EBLs was partially supported by the OSML.
Thermal Transient Response and Its Modeling for Joule Heating in Cu/Low-κ Interconnects Under Pulsed Current
Authors: Yokogawa Shinji , Tsuchiya Hideaki , Shimizu Tatsuo
Published: May 2012

We propose a thermal transient response due to Joule heating and its modeling in Cu/low-κ interconnects. By incorporating a shape parameter on the model, the observed thermal response is more accurately represented compared to the conventional exponential function model. The effective thermal time constant in multilayered Cu/low-κ interconnects is experimentally investigated on the basis of the transient thermal response.
Effects of Atmosphere and Ultraviolet Light Irradiation on Chemical Mechanical Polishing Characteristics of SiC Wafers
Authors: Ohnishi Osamu , Doi Toshiro , Kurokawa Syuhei , Yamazaki Tsutomu , Uneda Michio , Yin Tao , Koshiyama Isamu , Ichikawa Koichiro , Aida Hideo
Published: May 2012

To establish a high-efficiency and high-quality polishing process by controlling the workpiece environment, a prototype chemical mechanical polishing (CMP) machine that can perform double-side CMP simultaneously in a sealed pressure chamber was developed. Using this new machine, polishing experiments on single crystalline silicon carbide (SiC) wafers were carried out. The results showed that applying a highly pressurized O2 gas and ultraviolet light irradiation were effective in SiC CMP.
Ambulatory Arterial Stiffness Index Is Higher in Hypertensive Patients with Chronic Kidney Disease
Authors: Gismondi Ronaldo Altenburg , Neves Mario Fritsch , Oigman Wille , Bregman Rachel
Published: May 2012

Ambulatory arterial stiffness index (AASI) is a parameter obtained from ambulatory blood pressure monitoring (ABPM) that correlates with clinical endpoints. The aim of this study was to compare AASI in nondiabetic hypertensive patients with and without chronic kidney disease (CKD). Subjects with systemic arterial hypertension (SAH,n=30) with normal renal function, aged 40 to 75 years, were compared to hypertensive patients with CKD (n=30) presenting estimated glomerular filtration rate (eGFR) <60 mL/min by MDRD formula. ABPM was carried out in all patients. In CKD group, eGFR was 35.3 ± 2.8 ml/min. The mean 24-hour systolic and diastolic blood pressure (BP) was similar in both groups. AASI was significantly higher in CKD group (0.45±0.03versus0.37±0.02,P<0.05), positively correlated to age (r=0.38,P<0.01) and pulse pressure (r=0.43,P<0.01) and negatively correlated to nocturnal BP fall (r=-0.28,P=0.03). These findings indicate the presence of stiffer vessels in CKD hypertensive patients.
Eucalyptus Biodiesel as an Alternative to Diesel Fuel: Preparation and Tests on DI Diesel Engine
Authors: Tarabet Lyes , Loubar Khaled , Lounici Mohand Said , Hanchi Samir , Tazerout Mohand
Published: May 2012

Nowadays, the increasing oil consumption throughout the world induces crucial economical, security, and environmental problems. As a result, intensive researches are undertaken to find appropriate substitution to fossil fuels. In view of the large amount of eucalyptus trees present in arid areas, we focus in this study on the investigation of using eucalyptus biodiesel as fuel in diesel engine. Eucalyptus oil is converted by transesterification into biodiesel. Eucalyptus biodiesel characterization shows that the physicochemical properties are comparable to those of diesel fuel. In the second phase, a single cylinder air-cooled, DI diesel engine was used to test neat eucalyptus biodiesel and its blends with diesel fuel in various ratios (75, 50, and 25 by v%) at several engine loads. The engine combustion parameters such as peak pressure, rate of pressure rise, and heat release rate are determined. Performances and exhaust emissions are also evaluated at all operating conditions. Results show that neat eucalyptus biodiesel and its blends present significant improvements of carbon monoxide, unburned hydrocarbon, and particulates emissions especially at high loads with equivalent performances to those of diesel fuel. However, the NOx emissions are slightly increased when the biodiesel content is increased in the blend.
Some Properties of a Generalized Class of Analytic Functions Related with Janowski Functions
Authors: Arif M. , Noor K. I. , Raza M. , Haq W.
Published: May 2012

We define a class [A, B, α, ρ] of analytic functions by using Janowski’s functions which generalizes a number of classes studied earlier such as the class of strongly close‐to‐convex functions. Some properties of this class, including arc length, coefficient problems, and a distortion result, are investigated. We also discuss the growth of Hankel determinant problem.
Causal Information Approach to Partial Conditioning in Multivariate Data Sets
Authors: Marinazzo D. , Pellicoro M. , Stramaglia S.
Published: May 2012

When evaluating causal influence from one time series to another in a multivariate data set it is necessary to take into account the conditioning effect of the other variables. In the presence of many variables and possibly of a reduced number of samples, full conditioning can lead to computational and numerical problems. In this paper, we address the problem of partial conditioning to a limited subset of variables, in the framework of information theory. The proposed approach is tested on simulated data sets and on an example of intracranial EEG recording from an epileptic subject. We show that, in many instances, conditioning on a small number of variables, chosen as the most informative ones for the driver node, leads to results very close to those obtained with a fully multivariate analysis and even better in the presence of a small number of samples. This is particularly relevant when the pattern of causalities is sparse.
Probabilistic Approach to System Reliability of Mechanism with Correlated Failure Models
Authors: Huang Xianzhen , Zhang Yimin
Published: May 2012

In this paper, based on the kinematic accuracy theory and matrix‐based system reliability analysis method, a practical method for system reliability analysis of the kinematic performance of planar linkages with correlated failure modes is proposed. The Taylor series expansion is utilized to derive a general expression of the kinematic performance errors caused by random variables. A proper limit state function (performance function) for reliability analysis of the kinematic performance of planar linkages is established. Through the reliability theory and the linear programming method the upper and lower bounds of the system reliability of planar linkages are provided. In the course of system reliability analysis, the correlation of different failure modes is considered. Finally, the practicality, efficiency, and accuracy of the proposed method are shown by a numerical example.
Effects of PPARγLigands on Leukemia
Authors: Tabe Yoko , Konopleva Marina , Andreeff Michael , Ohsaka Akimichi
Published: May 2012

Peroxisome proliferator-activated receptors (PPARs) and retinoic acid receptors (RARs), members of the nuclear receptor superfamily, are transcription factors that regulate a variety of important cellular functions. PPARs form heterodimers retinoid X receptor (RXR), an obligate heterodimeric partner for other nuclear receptors. Several novel links between retinoid metabolism and PPAR responses have been identified, and activation of PPAR/RXR expression has been shown to increase response to retinoids. PPARγhas emerged as a key regulator of cell growth and survival, whose activity is modulated by a number of synthetic and natural ligands. While clinical trials in cancer patients with thiazolidinediones (TZD) have been disappointing, novel structurally different PPARγligands, including triterpenoids, have entered clinical arena as therapeutic agents for epithelial and hematopoietic malignancies. Here we shall review the antitumor advances of PPARγ, alone and in combination with RARαligands in control of cell proliferation, differentiation, and apoptosis and their potential therapeutic applications in hematological malignancies.
, -Dimethylphenylalanine : A Useful Aromatic Amino Acid Surrogate for Tyr or Phe Residue in Opioid Peptides
Authors: Sasaki Yusuke , Ambo Akihiro
Published: May 2012

Two aromatic amino acids, Tyr1 and Phe3 or Phe4, are important structural elements in opioid peptides because they interact with opioid receptors. The usefulness of an artificial amino acid residue ,-dimethylphenylalanine (Dmp) was investigated as an aromatic amino acid surrogate for several opioid peptides, including enkephalin, dermorphin, deltorphin, endomorphin, dynorphin A, and nociceptin peptides. In most peptides, substitutions of Phe3 by a Dmp residue produced analogs with improved receptor-binding affinity and selectivity, while the same substitution of Phe4 induced markedly reduced receptor affinity and selectivity. Interestingly, replacement of Tyr1 by Dmp produced analogs with unexpectedly high affinity or produced only a slight drop in receptor affinity and bioactivity for most peptides. Thus, Dmp is also a useful surrogate for the N-terminal Tyr residue in opioid peptides despite the lack of a phenolic hydroxyl group, which is considered necessary for opioid activity. The Dmp1-substituted analogs are superior to ,-dimethyltyrosine (Dmt)1-substituted analogs for high receptor selectivity since the latter generally have poor receptor selectivity. Thus, Dmp is very useful as an aromatic amino acid surrogate in opioid peptides and may be useful for developing other novel peptide mimetics with high receptor specificity.
Alterations of the Erythrocyte Membrane during Sepsis
Authors: Serroukh Yasmina , Djebara Sarah , Lelubre Christophe , Zouaoui Boudjeltia Karim , Biston Patrick , Piagnerelli Michael
Published: May 2012

Erythrocytes have been long considered as “dead” cells with transport of oxygen (O2) as their only function. However, the ability of red blood cells (RBCs) to modulate the microcirculation is now recognized as an important additional function. This capacity is regulated by a key element in the rheologic process: the RBC membrane. This membrane is a complex unit with multiple interactions between the extracellular and intracellular compartments: blood stream, endothelium, and other blood cells on the one hand, and the intracytoplasmic compartment with possible rapid adaptation of erythrocyte metabolism on the other. In this paper, we review the alterations in the erythrocyte membrane observed in critically ill patients and the influence of these alterations on the microcirculatory abnormalities observed in such patients. An understanding of the mechanisms of RBC rheologic alterations in sepsis and their effects on blood flow and on oxygen transport may be important to help reduce morbidity and mortality from severe sepsis.
River Cetaceans and Habitat Change: Generalist Resilience or Specialist Vulnerability?
Authors: Smith Brian D. , Reeves Randall R.
Published: May 2012

River dolphins are among the world’s most threatened mammals, and indeed the baiji (Lipotes vexillifer), a species endemic to China's Yangtze River, is likely extinct. Exploitation for products such as meat, oil, and skins has been a lesser feature in the population histories of river dolphins compared to most large mammals. Habitat factors are therefore of particular interest and concern. In this paper we attempt to describe the population-level responses of river dolphins to habitat transformation. We find circumstantial but compelling evidence supporting the view that, at a local scale, river dolphins are opportunists (generalists) capable of adapting to a wide range of habitat conditions while, at a river basin scale, they are more appropriately viewed as vulnerable specialists. The same evidence implies that the distributional responses of river dolphins to basinwide ecological change can be informative about their extinction risk, while their local behaviour patterns may provide important insights about critical ecological attributes. Empirical studies are needed on the ecology of river cetaceans, both to inform conservation efforts on behalf of these threatened animals and to help address broader concerns related to biodiversity conservation and the sustainability of human use in several of the world's largest river systems.
Microstereolithography of Three-Dimensional Polymeric Springs for Vibration Energy Harvesting
Authors: Baker Evan , Reissman Timothy , Zhou Fan , Wang Chen , Lynch Kevin , Sun Cheng
Published: May 2012

The inefficiency in converting low frequency vibration (6~240 Hz) to electrical energy remains a key issue for miniaturized vibration energy harvesting devices. To address this subject, this paper reports on the novel, three-dimensional micro-fabrication of spring elements within such devices, in order to achieve resonances and maximum energy conversion within these common frequencies. The process, known as projection microstereolithography, is exploited to fabricate polymer-based springs direct from computer-aided designs using digital masks and ultraviolet-curable resins. Using this process, a micro-spring structure is fabricated consisting of a two-by-two array of three-dimensional, constant-pitch helical coils made from 1,6-hexanediol diacrylate. Integrating the spring structure into an electromagnetic device, with a magnetic load mass of 1.236 grams, the resonance is measured at 61 Hz, which is within 2% of the theoretical model. The device provides a maximum normalized power output of 9.14 μW/G (G=9.81 ms−2) and an open circuit normalized voltage output of 621 mV/G. To the best of the authors knowledge, notable features of this work include the lowest Young’s modulus (530 MPa), density (1.011 g/cm3), and “largest feature size” (3.4 mm) for a spring element in a vibration energy harvesting device with sub-100 Hz resonance.
Exogenous High-Mobility Group Box 1 Protein Injection Improves Cardiac Function after Myocardial Infarction: Involvement of Wnt Signaling Activation
Authors: Zhou Xiaoya , Hu Xiaorong , Xie Jing , Xu Changwu , Xu Weipan , Jiang Hong
Published: May 2012

Exogenous high-mobility group box 1 protein (HMGB1) injection could prevent left ventricular remodeling and enhance left ventricular function during myocardial infarction (MI). However, the mechanism remains unclear. This paper was to investigate in the mechanism of cardioprotection of HMGB1 during MI in rats. Anesthetized male rats were treated once with HMGB1 (200 ng) 4 h after MI and then executed after 7 and 28 days, respectively. Cardiac function, collagen deposition, and dishevelled-1 andβ-catenin protein expression were measured. After MI 7 days or 28 days, the left ventricular ejection fraction (LVEF) was significantly decreased compared to that of sham-operated control group (P<0.05). However, the LVEF HMGB1-treated groups were significantly higher compared to those of the MI group in both 7 days and 28 days (P<0.05). The collagen volume fraction was significantly reduced in the HMGB1-treated group in infarcted border zone. HMGB1 could activate the expression of dishevelled-1 andβ-catenin proteins (P<0.05). Our study suggested that exogenous high-mobility group box 1 protein injection improves cardiac function after MI, which may be involved in Wnt/β-catenin signaling activation.
Stroma Targeting Nuclear Imaging and Radiopharmaceuticals
Authors: Shetty Dinesh , Jeong Jae-Min , Shim Hyunsuk
Published: May 2012

Malignant transformation of tumor accompanies profound changes in the normal neighboring tissue, called tumor stroma. The tumor stroma provides an environment favoring local tumor growth, invasion, and metastatic spreading. Nuclear imaging (PET/SPECT) measures biochemical and physiologic functions in the human body. In oncology, PET/SPECT is particularly useful for differentiating tumors from postsurgical changes or radiation necrosis, distinguishing benign from malignant lesions, identifying the optimal site for biopsy, staging cancers, and monitoring the response to therapy. Indeed, PET/SPECT is a powerful, proven diagnostic imaging modality that displays information unobtainable through other anatomical imaging, such as CT or MRI. When combined with coregistered CT data, [18F]fluorodeoxyglucose ([18F]FDG)-PET is particularly useful. However, [18F]FDG is not a target-specific PET tracer. This paper will review the tumor microenvironment targeting oncologic imaging such as angiogenesis, invasion, hypoxia, growth, and homing, and also therapeutic radiopharmaceuticals to provide a roadmap for additional applications of tumor imaging and therapy.
Complications, Reoperations, and Nutrient Deficiencies Two Years after Sleeve Gastrectomy
Authors: Pech Nicole , Meyer Frank , Lippert Hans , Manger Thomas , Stroh Christine
Published: May 2012

Background. The aim of this study was to investigate patient outcomes and nutritional deficiencies following sleeve gastrectomy (SG) during a follow-up of two years.Methods. Over a period of 56 months, all consecutive patients who underwent SG were documented in this prospective, single-center, observational study. The study endpoints included operative time, complication rates, nutritional deficiencies and percentage of excess weight loss (%EWL).Results. From September 26, 2005 to May 28, 2009, 82 patients (female : male = 48 : 34) with a mean age of 43.3 years (range: 22–64) and a preoperative BMI of 52.5 kg/m² (range: 36.8–77.0) underwent SG. Major complications were observed in 9.8% of the patients, with 1 death. During follow up 51.2% of patients were supplemented with iron, 36.6% with zinc, 37.8% with calcium, 26.8% with vitamin D, 46.3% with vitamin B12 and 41.5% with folic acid. %EWL was 54.3, 65.3 and 62.6% after 6, 12 and 24 months.Conclusion. SG as a single step procedure is an effective bariatric intervention. Nutritional deficiencies after SG can be detected by routine nutritional screening. Our results show that Vitamin B12 supplementation should suggest routinely after SG.
Piezoelectric Energy Harvesting Devices: An Alternative Energy Source for Wireless Sensors
Authors: Nechibvute Action , Chawanda Albert , Luhanga Pearson
Published: May 2012

The recent advances in ultralow power device integration, communication electronics, and microelectromechanical systems (MEMS) technology have fuelled the emerging technology of wireless sensor networks (WSNs). The spatial distributed nature of WSNs often requires that batteries power the individual sensor nodes. One of the major limitations on performance and lifetime of WSNs is the limited capacity of these finite power sources, which must be manually replaced when they are depleted. Moreover, the embedded nature of some of the sensors and hazardous sensing environment make battery replacement very difficult and costly. The process of harnessing and converting ambient energy sources into usable electrical energy is called energy harvesting. Energy harvesting raises the possibility of self-powered systems which are ubiquitous and truly autonomous, and without human intervention for energy replenishment. Among the ambient energy sources such as solar energy, heat, and wind, mechanical vibrations are an attractive ambient source mainly because they are widely available and are ideal for the use of piezoelectric materials, which have the ability to convert mechanical strain energy into electrical energy. This paper presents a concise review of piezoelectric microgenerators and nanogenerators as a renewable energy resource to power wireless sensors.
The Use of Statistical Tests to Calibrate the Black-Scholes Asset Dynamics Model Applied to Pricing Options with Uncertain Volatility
Authors: Fatone Lorella , Mariani Francesca , Recchioni Maria Cristina , Zirilli Francesco
Published: May 2012

A new method for calibrating the Black-Scholes asset price dynamics model is proposed. The data used to test the calibration problem included observations of asset prices over a finite set of (known) equispaced discrete time values. Statistical tests were used to estimate the statistical significance of the two parameters of the Black-Scholes model: the volatility and the drift. The effects of these estimates on the option pricing problem were investigated. In particular, the pricing of an option with uncertain volatility in the Black-Scholes framework was revisited, and a statistical significance was associated with the price intervals determined using the Black-Scholes-Barenblatt equations. Numerical experiments involving synthetic and real data were presented. The real data considered were the daily closing values of the S&P500 index and the associated European call and put option prices in the year 2005. The method proposed here for calibrating the Black-Scholes dynamics model could be extended to other science and engineering models that may be expressed in terms of stochastic dynamical systems.
Microstructure and Mechanical Properties of Heterogeneous Ceramic‐Polymer Composite Using Interpenetrating Network
Authors: Kim Eun-Hee , Jung Yeon-Gil , Jo Chang-Yong
Published: May 2012

Prepolymer, which can be polymerized by a photo, has been infiltrated into a porous
ceramic to improve the addition effect of polymer into the ceramic, as a function of the
functionality of prepolymer. It induces the increase in the mechanical properties of the
ceramic. The porous alumina (Al2O3) and the polyurethane acrylate (PUA)
with a network structure by photo‐polymerization were used as the matrix and
infiltration materials, respectively. The porous Al2O3 matrix without the polymer shows lower values in fracture strength than the composites, since the stress is transmitted more quickly via
propagation of cracks from intrinsic defects in the porous matrix. However, in the case
of composites, the distribution of stress between heterophases results in the improved
mechanical properties. In addition, the mechanical properties of composites, such as
elastic modulus and fracture strength, are enhanced with increasing the functionality of
prepolymer attributed to the crosslinking density of polymer.
Fetal Longitudinal Myocardial Function Assessment by Anatomic M-Mode
Authors: Germanakis Ioannis , Pepes Spyridon , Sifakis Stavros , Gardiner Helena
Published: May 2012

Aim: To evaluate the feasibility of offline anatomic M-mode (AMM) to study fetal atrioventricular annulus long-axis displacement (LAD) and compare its performance against real-time conventional M-mode (MM). Material and Methods: Paired AMM and MM LAD studies were recorded prospectively in 54 fetuses, and performance was compared. Insonation angles were less than 30° in all but 4 cases. The overall feasibility of AMM was tested in a composite total sample of 91 normal singleton pregnancies (median gestational age 23+6 weeks, range 12–36). AMM LAD was measured by placement of a virtual M-mode line on digitally stored raw data of fetal 4-chamber video loops. We studied annulus LAD at the lateral mitral (left ventricle; LV), proximal mitral (intraventricular septum; IVS), and lateral tricuspid (right ventricle; RV) myocardial segments. We compared LAD and its regression with gestational age measured using both methods in paired studies and AMM in the whole cohort. Results: Annulus LAD was measured using AMM, in all cases and segments, irrespective of cardiac axis alignment to the ultrasound beam. Good correlation existed between AMM and MM (RV r = 0.901, LV r = 0.899, IVS r = 0.815, p < 0.001). AMM recorded higher LAD values than MM in RV [mean 6.17 (SD 1.46) vs. 5.82 (SD 1.74) mm, p = 0.002] and LV [mean 4.18 (SD 1.11) vs. 3.98 (SD 1.12), p = 0.007]. Both methods showed LAD in RV > LV > IVS and a significant gestational increase in LAD values in all segments (p < 0.001) Conclusions: AMM permits offline evaluation of fetal longitudinal myocardial function in routinely obtained 2D fetal heart images with similar values to conventional MM in paired studies recorded <30°.
Comparison of PR Intervals Determined by Fetal Magnetocardiography and Pulsed Doppler Echocardiography
Authors: Kato Yoshiaki , Takahashi-Igari Miho , Inaba Takeshi , Sumazaki Ryo , Horigome Hitoshi
Published: May 2012

Objective: In clinical practice, measurement of mechanical PR interval (mPR) with pulsed Doppler echocardiography is a standard method used to estimate the atrioventricular conduction time in the fetus. However, fetal echocardiography does not directly reflect the electrical properties of the heart. Technological advances in fetal magnetocardiography (fMCG) have allowed recording of the electrical PR interval (ePR) with high time resolution. The aim of this study was to clarify the differences between ePR and mPR. Methods: The study subjects were 295 normal human fetuses (gestational age, range 20.4–41.4 weeks) who underwent fMCG, and 135 of them underwent fetal echocardiography 15–90 min before or after fMCG. The ePR was measured using the fMCG, and the mPR was determined by two pulsed Doppler methods, simultaneous recording of the left ventricular inward and outward flow (LV in/out) (n = 135) and superior vena cava and ascending aorta (SVC/aAo) (n = 84). Results: The ePR showed a significant, but weak, positive correlation with gestational age (r = 0.162, p = 0.0053). The mPR was significantly longer than the ePR (p < 0.0001), with mean differences of 14.6% (95% limits of agreement –10.7, 39.9) for the LV in/out method and 14.7% (95% limits of agreement –8.6, 38.0) for the SVC/aAo method. Conclusion: Our results point to the risk of overestimation of the atrioventricular conduction time when the mPR is used, and the need for careful interpretation of PR prolongation determined by mPR.
A Three-Dimensional Model of Thoughts: Insight into Depression
Authors: Desseilles Martin , Chang Trina , Piguet Camille , Bertschy Gilles , Dayer Alexandre G.
Published: May 2012

Thought processing and mood regulation are closely linked, but existing classifications of mood disorders fail to recognize the complex interplay between these two clinical dimensions. Furthermore, existing classifications fail to account for the possibility that depression might be associated with an increased frequency of self-referential thoughts that could in some circumstances be related to creativity processes. Based on recent evidence from clinical phenomenology, experimental psychology and affective neuroscience, we propose a novel comprehensive theoretical framework that incorporates thought processing and emotional valence. This new taxonomy provides insights into the clinical understanding of the spectrum of mood disorders and accounts for the possibility of increased creativity in altered mood states.
Study of the Correlation of Imipenem Resistance with Efflux Pumps AdeABC, AdeIJK, AdeDE and AbeM in Clinical Isolates of Acinetobacter baumannii
Authors: Hou Pan Fei , Chen Xiao Ying , Yan Gang Feng , Wang Ya Ping , Ying Chun Mei
Published: May 2012

Background: To investigate the role of efflux pumps AdeABC, AdeIJK, AdeDE and AbeM in reduced susceptibility to imipenem in clinical isolates of Acinetobacter baumannii. Methods: Susceptibility testing was conducted by the agar dilution method. The presence and expression of pump genes were analyzed by conventional PCR and real-time RT-PCR, respectively. Results: Most antibiotics, including carbapenem, aminoglycosides, fluoroquinolones and cephalosporins showed high minimum inhibitory concentration (MIC) values in imipenem-resistant A. baumannii (IRAB). After exposure to the efflux pump inhibitor Phe-Arg-β-naphthylamide, a 4- to 32-fold reduction of imipenem MICs was observed in 33 (66%) isolates of IRAB, while no significant decrease occurred in imipenem-susceptible A. baumannii (ISAB). The majority of IRAB isolates (>80%) were found to be positive for adeB, adeR, adeS, adeJ and abeM. Positive adeE was discovered in 6 isolates of IRAB and coexisted with adeB. Approximate 4-, 3- and 11-fold increases in adeB, adeJ and abeM expression were observed, respectively, in IRAB compared to those in ISAB. Conclusions: A variety of efflux pump systems, including AdeABC, AdeIJK and AbeM, seem to play important roles in the resistance to imipenem of A. baumannii. Moreover, this is the first time that adeE has been found to coexist with adeB in a small number of isolates of A. baumannii.