bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of high substrate bias and hydrogen and nitrogen incorporation on density of states and field-emission threshold in tetrahedral amorphous carbon films
Authors: Panwar O. S. , Khan M. A. , Satyanarayana B. S. , Bhattacharyya R. , Mehta B. R. , Kumar S. , Ishpal
Published: March 2010

This article reports the influence of substrate bias during growth and of hydrogen and nitrogen incorporation on density of states [N (EF)] and field-emission threshold (Eturn-on) in tetrahedral amorphous carbon (ta-C) films, deposited using an S-bend filtered cathodic vacuum arc process. The variation in negative substrate bias from −20 to −200 V was found to initially lead to a small decrease in N (EF) and Eturn-on, and a small increase in the emission current density (J) at 12.5 V/μm in the case of as-grown ta-C films; beyond −200 V substrate bias there is a reversal in the trend. The values of N (EF)=1.3×1017 cm−3 eV−1, Eturn-on=8.3 V/μm, and J=6.19 mA/cm2 were observed at −200 V substrate bias. However at −300 V the properties were not very different from those at −200 V substrate bias and so with a view to use the higher energy, hydrogen and nitrogen incorporation studies were carried out in this condition. It was observed that there was further enhancement in properties with hydrogen and nitrogen incorporation. The best properties measured with in the range of hydrogen and nitrogen incorporation in the present study were N (EF)=8.0×1016 cm−3 eV−1, Eturn-on=7.6 V/μm, and J=23.7 mA/cm2, respectively.
Luminescent characteristics in blue-emitting Bi-activated multicomponent oxide phosphor thin films
Authors: Minami Tadatsugu , Miyata Toshihiro , Ishino Jun-ichi , Sahara Keiichi
Published: March 2010

The luminescent characteristics in developed blue-emitting Bi-activated multicomponent oxide phosphor thin films that are composed of various combinations of La2O3, Y2O3, and Gd2O3 as the host material are investigated; ((La2O3)1−X–(Gd2O3)X):Bi, (Gd2O3)1−Y–(Y2O3)Y):Bi, and ((Y2O3)1−Z–(La2O3)Z):Bi phosphor thin films were prepared on thick BaTiO3 ceramic sheets by either a conventional or a combinatorial rf magnetron sputtering deposition method using a powder target. The resulting phosphor thin films, which were prepared with various chemical compositions and postannealed above about 800 °C in an Ar gas atmosphere, all exhibited photoluminescent (PL) and electroluminescent (EL) emissions. However, the PL emission spectra observed from these phosphor thin films were considerably affected by the ultraviolet (UV) light used in the excitation. Intensive blue PL emissions were obtained in all of the phosphor thin films that were postannealed at 1050 °C and excited by an appropriate UV light. In comparison with the PL emission spectra, the EL emission spectra observed from thin-film electroluminescent (TFEL) devices fabricated using the Bi-activated multicomponent oxide phosphor thin films as the emitting layer exhibited a redshift of the emission band or an emergence of a new emission band accompanied by spectral broadening at longer wavelengths. In addition, high-luminance blue-green EL emissions were obtained in TFEL devices fabricated using the above phosphor thin films and driven by a sinusoidal wave ac voltage at 1 kHz.
Plasmacytoid Dendritic Cells Delineate Immunogenicity of Influenza Vaccine Subtypes
Authors: Koyama Shohei , Aoshi Taiki , Tanimoto Takeshi , Kumagai Yutaro , Kobiyama Kouji , Tougan Takahiro , Sakurai Kazuo , Coban Cevayir , Horii Toshihiro , Akira Shizuo , Ishii Ken J.
Published: March 2010

Rare, circulating dendritic cells differentially shape the immunogenicity mechanisms for protection against H1N1 influenza.
Giving Tumors the Silent Treatment
Authors: Alumkal Joshi
Published: March 2010

Systemic delivery of siRNA via nanoparticles selectively silences genes in cancer cells from patients with melanoma.
COMPLETE SAT-BASED MODEL CHECKING FOR CONTEXT-FREE PROCESSES
Authors: HUANG GENG-DIAN , WANG BOW-YAW
Published: March 2010

A complete SAT-based model checking algorithm for context-free processes is presented. We reduce proof search in local model checking to Boolean satisfiability. Bounded proof search can therefore be performed by SAT solvers. Moreover, the completeness of proof search is reduced to Boolean unsatisfiability and hence can be checked by SAT solvers. By encoding the local model checking algorithm in [13], SAT solvers are able to verify properties in the universal fragment of alternation-free µ-calculus formulae on context-free processes. Since software programs can be modeled by context-free processes, our result demonstrates that a purely SAT-based algorithm for software verification is indeed possible.
CONTINUOUS PETRI NETS: EXPRESSIVE POWER AND DECIDABILITY ISSUES
Authors: RECALDE LAURA , HADDAD SERGE , SILVA MANUEL
Published: March 2010

State explosion is a fundamental problem in the analysis and synthesis of discrete event systems. Continuous Petri nets can be seen as a relaxation of the corresponding discrete model. The expected gains are twofold: improvements in complexity and in decidability. In the case of autonomous nets we prove that liveness or deadlock-freeness remain decidable and can be checked more efficiently than in Petri nets. Then we introduce time in the model which now behaves as a dynamical system driven by differential equations and we study it w.r.t. expressiveness and decidability issues. On the one hand, we prove that this model is equivalent to timed differential Petri nets which are a slight extension of systems driven by linear differential equations (LDE). On the other hand, (contrary to the systems driven by LDEs) we show that continuous timed Petri nets are able to simulate Turing machines and thus that basic properties become undecidable.
ESTIMATING UNIVARIATE DISTRIBUTIONS VIA RELATIVE ENTROPY MINIMIZATION: CASE STUDIES ON FINANCIAL AND ECONOMIC DATA
Authors: FRIEDMAN CRAIG , ZHANG YANGYONG , HUANG JINGGANG
Published: March 2010

We use minimum relative entropy (MRE) methods to estimate univariate probability density functions for a varied set of financial and economic variables, including S&P500 index returns, individual stock returns, power price returns and a number of housing-related economic variables. Some variables have fat tail distributions, others have finite support. Some variables have point masses in their distributions and others have multimodal distributions. We indicate specifically how the MRE approach can be tailored to the stylized facts of the variables that we consider and benchmark the MRE approach against alternative approaches. We find, for a number of variables, that the MRE approach outperforms the benchmark methods.
INFERENCE OF GENETIC NETWORKS USING LPMs: ASSESSMENT OF CONFIDENCE VALUES OF REGULATIONS
Authors: KIMURA SHUHEI , SHIRAISHI YUICHI , OKADA MARIKO
Published: March 2010

When we apply inference methods based on a set of differential equations into actual genetic network inference problems, we often end up with a large number of false-positive regulations. However, as we must check the inferred regulations through biochemical experiments, fewer false-positive regulations are preferable. In order to reduce the number of regulations checked, this study proposes a new method that assigns confidence values to all of the regulations contained in the target network. For this purpose, we combine a residual bootstrap method with the existing method, i.e. the inference method using linear programming machines (LPMs). Through numerical experiments on an artificial genetic network inference problem, we confirmed that most of the regulations with high confidence values are actually present in the target networks. We then used the proposed method to analyze the bacterial SOS DNA repair system, and succeeded in assigning reasonable confidence values to its regulations. Although this study combined the bootstrap method with the inference method using the LPMs, the proposed bootstrap approach could be combined with any method that has an ability to infer a genetic network from time-series of gene expression levels.
Bio-Enabled Synthesis of Metamaterials
Authors: DuFort Christopher C. , Dragnea Bogdan
Published: March 2010

Biological systems offer more than an inspiration for the spontaneous hierarchical organization of matter at length scales between 1 and 1000 nm. They also provide useful principles and molecular building blocks that have recently emerged with the proven ability to generate extended three-dimensional structures of hybrid biotic/abiotic components arranged with molecular precision. These principles and tools draw from the methods of molecular biology and modern biochemistry and are expected to provide unmatched flexibility in building supramolecular architectures, notably structures made of artificial atoms whose coupled responses to electromagnetic or elastic excitations have been predicted to yield astonishing properties unparalleled by any conventional materials. To illustrate the potential of merging bio-enabled organization with metamaterials synthesis, we provide here a succinct overview of the architectural constraints leading to metamaterial behavior together with examples of biological material assembly that are particularly promising to comply with these constraints.
From Artificial Atoms to Nanocrystal Molecules: Preparation and Properties of More Complex Nanostructures
Authors: Choi Charina L. , Alivisatos A. Paul
Published: March 2010

Quantum dots, which have found widespread use in fields such as biomedicine, photovoltaics, and electronics, are often called artificial atoms due to their size-dependent physical properties. Here this analogy is extended to consider artificial nanocrystal molecules, formed from well-defined groupings of plasmonically or electronically coupled single nanocrystals. Just as a hydrogen molecule has properties distinct from two uncoupled hydrogen atoms, a key feature of nanocrystal molecules is that they exhibit properties altered from those of the component nanoparticles due to coupling. The nature of the coupling between nanocrystal atoms and its response to vibrations and deformations of the nanocrystal molecule bonds are of particular interest. We discuss synthetic approaches, predicted and observed physical properties, and prospects and challenges toward this new class of materials.
The Diabatic Picture of Electron Transfer, Reaction Barriers, and Molecular Dynamics
Authors: Van Voorhis Troy , Kowalczyk Tim , Kaduk Benjamin , Wang Lee-Ping , Cheng Chiao-Lun , Wu Qin
Published: March 2010

Diabatic states have a long history in chemistry, beginning with early valence bond pictures of molecular bonding and extending through the construction of model potential energy surfaces to the modern proliferation of methods for computing these elusive states. In this review, we summarize the basic principles that define the diabatic basis and demonstrate how they can be applied in the specific context of constrained density functional theory. Using illustrative examples from electron transfer and chemical reactions, we show how the diabatic picture can be used to extract qualitative insight and quantitative predictions about energy landscapes. The review closes with a brief summary of the challenges and prospects for the further application of diabatic states in chemistry.
Enhanced Sampling of Nonequilibrium Steady States
Authors: Dickson Alex , Dinner Aaron R.
Published: March 2010

We review recent progress in methods for accelerating the convergence of simulations of nonequilibrium systems, specifically nonequilibrium umbrella sampling (NEUS) and forward flux sampling (FFS). These methods account for statistics of dynamical paths between interfaces to enforce sampling of low probability regions of phase space for computing steady-state averages, including transition rates, for systems driven arbitrarily far from equilibrium. Recent advances in NEUS allow for efficient sampling of complex systems by focusing sampling in the vicinity of a one-dimensional manifold (string) that connects regions of interest in phase space; this procedure can be extended to the case of two strings that describe the forward and backward transition ensembles separately, which is useful, as they do not, in general, coincide. We recast FFS in the framework of NEUS to facilitate comparison of the two methods. We conclude by discussing selected applications of interest.
On Walking in the Footprints of Giants
Authors: Jacox Marilyn E.
Published: March 2010

This article tells of a lifelong fascination with light, a messenger bearing information from realms ranging from the galactic to the submicroscopic. Personal interactions have shaped and informed this life journey. Accounts of some of the most important of these are related. Infrared and electronic spectra have been obtained, often for the first time, for many small free radicals and molecular ions—short-lived reaction intermediates in most chemical processes. The infrared spectrum of a molecule tells how its atoms vibrate with respect to one another and is as characteristic of the molecule as a fingerprint is of a person. Analysis of this spectrum provides sometimes surprising information about the structure and chemical bonding of the molecule in its lowest-energy electronic state. The electronic spectrum provides information on the molecule in more highly excited electronic states, in which its structure or reaction pattern may change or it may decompose.
Complex Fluids: Probing Mechanical Properties of Biological Systems with Optical Tweezers
Authors: Ou-Yang H. Daniel , Wei Ming-Tzo
Published: March 2010

The mechanical properties of cells are crucial for cell sensing and reaction to mechanical environments. This review describes the basic principles of optical tweezers and their use as force sensors for studying the mechanical properties of biological systems. It covers experiments of four groups of biological systems arranged by increasing complexity: (a) packaging DNA into viral capsids by bacteriophage portal motors and the dynamical stiffness of DNA upon protein binding, (b) actin-coated giant vesicles and the myosin-II embedded actin polymer network, (c) suspension cells, and (d) adhesion cells. These examples demonstrate how optical tweezers have been used to improve the understanding of the mechanical properties of biological systems at subcellular and molecular levels.
Subcellular Dynamics and Protein Conformation Fluctuations Measured by Fourier Imaging Correlation Spectroscopy
Authors: Senning Eric N. , Marcus Andrew H.
Published: March 2010

Novel high signal-to-noise spectroscopic experiments that probe the dynamics of microscopic objects have the potential to reveal complex intracellular biochemical mechanisms, or the slow relaxations of soft matter systems. This article reviews the implementation of Fourier imaging correlation spectroscopy (FICS), a phase-selective approach to fluorescence fluctuation spectroscopy that employs a unique route to elevate signal levels while acquiring detailed information about molecular coordinate trajectories. The review demonstrates the broad applicability of FICS by discussing two recent studies. The dynamics of Saccharomyces cerevisiae yeast mitochondria are characterized with FICS and provide detailed information about the influence of specific cytoskeletal elements on the movement of this organelle. In another set of experiments, polarization-modulated FICS captures conformational dynamics and molecular translational dynamics of the fluorescent protein DsRed, and analyses by four-point correlation and joint distribution functions of the corresponding data reveal statistically meaningful pathways of DsRed switching between different optical conformations.
Biological Cluster Mass Spectrometry
Authors: Winograd Nicholas , Garrison Barbara J.
Published: March 2010

This article reviews the new physics and new applications of secondary ion mass spectrometry using cluster ion probes. These probes, particularly C60, exhibit enhanced molecular desorption with improved sensitivity owing to the unique nature of the energy-deposition process. In addition, these projectiles are capable of eroding molecular solids while retaining the molecular specificity of mass spectrometry. When the beams are microfocused to a spot on the sample, bioimaging experiments in two and three dimensions are feasible. We describe emerging theoretical models that allow the energy-deposition process to be understood on an atomic and molecular basis. Moreover, experiments on model systems are described that allow protocols for imaging on biological materials to be implemented. Finally, we present recent applications of imaging to biological tissue and single cells to illustrate the future directions of this methodology.
Dynamics on the Way to Forming Glass: Bubbles in Space-Time
Authors: Chandler David , Garrahan Juan P.
Published: March 2010

We review a theoretical perspective of the dynamics of glass-forming liquids and the glass transition, a perspective developed during this past decade based on the structure of trajectory space. This structure emerges from spatial correlations of dynamics that appear in disordered systems as they approach nonergodic or jammed states. It is characterized in terms of dynamical heterogeneity, facilitation, and excitation lines. These features are associated with a newly discovered class of nonequilibrium phase transitions. Equilibrium properties have little, if anything, to do with it. The broken symmetries of these transitions are obscure or absent in spatial structures, but they are vivid in space-time (i.e., trajectory space). In our view, the glass transition is an example of this class of transitions. The basic ideas and principles we review were originally developed through the analysis of idealized and abstract models. Nevertheless, the central ideas are easily illustrated with reference to molecular dynamics of more realistic atomistic models, and we use that illustrative approach here.
Statistical Mechanical Concepts in Immunology
Authors: Chakraborty Arup K. , Košmrlj Andrej
Published: March 2010

Higher organisms, such as humans, have an adaptive immune system that usually enables them to successfully combat diverse (and evolving) microbial pathogens. The adaptive immune system is not preprogrammed to respond to prescribed pathogens. Yet it mounts pathogen-specific responses against diverse microbes and establishes memory of past infections (the basis of vaccination). Although major advances have been made in understanding pertinent molecular and cellular phenomena, the mechanistic principles that govern many aspects of an immune response are not known. We illustrate how complementary approaches from the physical and life sciences can help confront this challenge. Specifically, we describe work that brings together statistical mechanics and cell biology to shed light on how key molecular/cellular components of the adaptive immune system are selected to enable pathogen-specific responses. We hope these examples encourage physical chemists to work at this crossroad of disciplines where fundamental discoveries with implications for human health might be made.
Dietary iron restriction or iron chelation protects from diabetes and loss of β-cell function in the obese (ob/ob lep−/−) mouse
Authors: Cooksey Robert C. , Jones Deborah , Gabrielsen Scott , Huang Jingyu , Simcox Judith A. , Luo Bai , Soesanto Yudi , Rienhoff Hugh , Dale Abel E. , McClain Donald A.
Published: March 2010

Iron overload can cause insulin deficiency, but in some cases this may be insufficient to result in diabetes. We hypothesized that the protective effects of decreased iron would be more significant with increased β-cell demand and stress. Therefore, we treated the ob/ob mouse model of type 2 diabetes with an iron-restricted diet (35 mg/kg iron) or with an oral iron chelator. Control mice were fed normal chow containing 500 mg/kg iron. Neither treatment resulted in iron deficiency or anemia. The low-iron diet significantly ameliorated diabetes in the mice. The effect was long lasting and reversible. Ob/ob mice on the low-iron diet exhibited significant increases in insulin sensitivity and β-cell function, consistent with the phenotype in mouse models of hereditary iron overload. The effects were not accounted for by changes in weight or feeding behavior. Treatment with iron chelation had a more dramatic effect, allowing the ob/ob mice to maintain normal glucose tolerance for at least 10.5 wk despite no effect on weight. Although dietary iron restriction preserved β-cell function in ob/ob mice fed a high-fat diet, the effects on overall glucose levels were less apparent due to a loss of the beneficial effects of iron on insulin sensitivity. Beneficial effects of iron restriction were minimal in wild-type mice on normal chow but were apparent in mice on high-fat diets. We conclude that, even at “normal” levels, iron exerts detrimental effects on β-cell function that are reversible with dietary restriction or pharmacotherapy.
Sustained hypercapnia induces cerebral microvascular degeneration in the immature brain through induction of nitrative stress
Authors: Honoré Jean-Claude , Kooli Amna , Hou Xin , Hamel David , Rivera José Carlos , Picard Émilie , Hardy Pierre , Tremblay Sophie , Varma Daya R. , Jankov Robert P. , Mancini Joseph A. , Balazy Michael , Chemtob Sylvain
Published: March 2010

Hypercapnia is regularly observed in chronic lung disease, such as bronchopulmonary dysplasia in preterm infants. Hypercapnia results in increased nitric oxide synthase activity and in vitro formation of nitrates. Neural vasculature of the immature subject is particularly sensitive to nitrative stress. We investigated whether exposure to clinically relevant sustained high CO2 causes microvascular degeneration in the newborn brain by inducing nitrative stress, and whether this microvascular degeneration has an impact on brain growth. Newborn rat pups were exposed to 10% CO2 as inspired gas (PaCO2 = 60–70 mmHg) starting within 24 h of birth until postnatal day 7 (P7). Brains were notably collected at different time points to measure vascular density, determine brain cortical nitrite/nitrate, and trans-arachidonic acids (TAAs; products of nitration) levels as effectors of vessel damage. Chronic exposure of rat pups to high CO2 (PaCO2 ≈ 65 mmHg) induced a 20% loss in cerebrovascular density at P3 and a 15% decrease in brain mass at P7; at P30, brain mass remained lower in CO2-exposed animals. Within 24 h of exposure to CO2, brain eNOS expression and production of nitrite/nitrate doubled, lipid nitration products (TAAs) increased, and protein nitration (3-nitrotyrosine immunoreactivity) was also coincidently augmented on brain microvessels (lectin positive). Intracerebroventricular injection of TAAs (10 μM) replicated cerebrovascular degeneration. Treatment of rat pups with NOS inhibitor (l-Nω-nitroarginine methyl ester) or a peroxynitrite decomposition catalyst (FeTPPS) prevented hypercapnia-induced microvascular degeneration and preserved brain mass. Cytotoxic effects of high CO2 were reproduced in vitro /ex vivo on cultured endothelial cells and sprouting microvessels. In summary, hypercapnia at values frequently observed in preterm infants with chronic lung disease results in increased nitrative stress, which leads to cerebral cortical microvascular degeneration and curtails brain growth.
Effect of ACE2 and angiotensin-(1–7) in a mouse model of early chronic kidney disease
Authors: Dilauro Marc , Zimpelmann Joseph , Robertson Susan J. , Genest Dominique , Burns Kevin D.
Published: March 2010

Angiotensin-converting enzyme 2 (ACE2) is expressed at high levels in the kidney and converts angiotensin II (ANG II) to ANG-(1–7). We studied the effects of ACE2 inhibition and ANG-(1–7) in the ⅚ nephrectomy (⅚ Nx) mouse model of chronic kidney disease (CKD). Male FVB mice underwent sham surgery (Sham) or ⅚ Nx and were administered either vehicle, the ACE2 inhibitor MLN-4760 (MLN), the AT1 receptor antagonist losartan, MLN plus losartan, or ANG-(1–7) for 4 wk. In ⅚ Nx mice with or without MLN, kidney cortical ACE2 protein expression was significantly decreased at 4 wk, compared with Sham. Inhibition of ACE2 caused a decrease in renal cortical ACE2 activity. Kidney cortical ACE expression and activity did not differ between groups of mice. In ⅚ Nx mice treated with MLN, kidney levels of ANG II were significantly increased, compared with Sham. ⅚ Nx induced a mild but insignificant increase in blood pressure (BP), a 50% reduction in FITC-inulin clearance, and a significant increase in urinary albumin excretion. ACE2 inhibition in ⅚ Nx mice did not affect BP or FITC-inulin clearance but significantly increased albuminuria compared with ⅚ Nx alone, an effect reversed by losartan. Treatment of ⅚ Nx mice with ANG-(1–7) increased kidney and plasma levels of ANG-(1–7) but did not alter BP, FITC-inulin clearance, or urinary albumin excretion, and it increased relative mesangial area. These data indicate that kidney ACE2 is downregulated in the early period after ⅚ Nx. Inhibition of ACE2 in ⅚ Nx mice increases albuminuria via an AT1 receptor-dependent mechanism, independent of BP. In contrast, ANG-(1–7) does not affect albuminuria after ⅚ Nx. We propose that endogenous ACE2 is renoprotective in CKD.
Expression of Neuronal Nitric Oxide Synthase in Rabbit Carotid Body Glomus Cells Regulates Large-Conductance Ca2+-Activated Potassium Currents
Authors: Li Yu-Long , Zheng Hong , Ding Yanfeng , Schultz Harold D.
Published: March 2010

Our previous studies show that a decrease in endogenous nitric oxide (NO) is involved in the blunted outward K+ currents in carotid body (CB) glomus cells from chronic heart failure (CHF) rabbits. In the present study, we measured the effects of the neuronal nitric oxide synthase (nNOS) transgene on the K+ currents in CB glomus cells from pacing-induced CHF rabbits. Using single-cell real-time RT-PCR and immunofluorescent techniques, we found that nNOS mRNA and protein are expressed in the rabbit CB glomus cells and CHF decreased the expression of nNOS mRNA and protein in CB glomus cells. After 3 days of an adenoviral nNOS (Ad.nNOS) gene transfection, the expression of nNOS protein was increased to the level found in sham CB glomus cells. In whole cell patch-clamp experiments, Ad.nNOS markedly reversed the attenuated K+ currents in CB glomus cells from CHF rabbits. The specific nNOS inhibitor (S-methyl-l-thiocitrulline [SMTC]) and large-conductance Ca2+-activated K+ (BK) channel blocker (iberiotoxin) fully abolished the effect of Ad.nNOS on the K+ currents in the CB glomus cells from CHF rabbits. However, neither CHF nor Ad.nNOS altered the protein expression of BK channel α-subunit. These results suggest that a decrease of NO induced by an attenuated nNOS activity lowers the activation of the BK channels but not the protein expression of the BK channel α-subunit in the CB glomus cells during CHF.
Onecut-2 knockout mice fail to thrive during early postnatal period and have altered patterns of gene expression in small intestine
Authors: Dusing Mary R. , Maier Elizabeth A. , Aronow Bruce J. , Wiginton Dan A.
Published: March 2010

Ablation of the mouse genes for Onecut-2 and Onecut-3 was reported previously, but characterization of the resulting knockout mice was focused on in utero development, principally embryonic development of liver and pancreas. Here we examined postnatal development of these Onecut knockout mice, especially the critical period before weaning. Onecut-3 knockout mice develop normally during this period. However, Onecut-2 knockout mice fail to thrive, lagging behind their littermates in size and weight. By postnatal day (d)19, they are consistently 25–30% smaller. Onecut-2 knockout mice also have a much higher level of mortality before weaning, with only ∼70% survival. Interestingly, Onecut-2 knockout mice that are heterozygous for the Onecut-3 knockout allele are diminished even further in their ability to thrive. They are ∼50–60% as large as their normal-sized littermates at d19, and less than half of these mice survive to weaning. As reported previously, the Onecut-2/Onecut-3 double knockout is a perinatal lethal. Microarray technology was used to determine the effect of Onecut-2 ablation on gene expression in duodenum, whose epithelium has among the highest levels of Onecut-2. A subset of intestinally expressed genes showed dramatically altered patterns of expression. Many of these genes encode proteins associated with the epithelial membrane, including many involved in transport and metabolism. Previously, we reported that Onecut-2 was critical to temporal regulation of the adenosine deaminase gene in duodenum. Many of the genes with altered patterns of expression in Onecut-2 knockout mouse duodenum displayed changes in the timing of gene expression.
Use of Cone Beam Computed Tomography in Endodontics
Authors: Scarfe William C. , Levin Martin D. , Gane David , Farman Allan G.
Published: March 2010

Cone Beam Computed Tomography (CBCT) is a diagnostic imaging modality that provides high-quality, accurate three-dimensional (3D) representations of the osseous elements of the maxillofacial skeleton. CBCT systems are available that provide small field of view images at low dose with sufficient spatial resolution for applications in endodontic diagnosis, treatment guidance, and posttreatment evaluation. This article provides a literature review and pictorial demonstration of CBCT as an imaging adjunct for endodontics.
Note on the Numerical Solutions of the General Matrix ConvolutionEquations by Using the Iterative Methods and Box Convolution Product
Authors: Kılıçman Adem , Al zhour Zeyad
Published: March 2010

We define the so‐called box convolution product and study their properties in order to present the approximate solutions for the general coupled matrix convolution equations by using iterative methods. Furthermore, we prove that these solutions consistently converge to the exact solutions and independent of the initial value.
Molecular Profiling of Endometrial Malignancies
Authors: Samarnthai Norasate , Hall Kevin , Yeh I-Tien
Published: March 2010

Molecular profiling of endometrial neoplasms reveals genetic changes in endometrial carcinomas that support the dualistic model, in which type I carcinomas are estrogen‐dependent, low grade lesions and type II carcinomas are nonestrogen dependent and high grade. The molecular changes in type I endometrial carcinomas include mutations in PTEN, PIK3CA, KRAS, and β‐catenin, along with microsatellite instability, whereas type II endometrial carcinomas are characterized by genetic alterations in p53, HER2/neu, p16, and E‐cadherin. For endometrial neoplasms with a malignant mesenchymal component, C-MYC mutations and loss of heterozygosity are frequently seen in carcinosarcomas, and a fusion gene, JAZF1/JJAZ1, is distinctive for endometrial stromal sarcoma. In addition, p53 mutations may play an important role in tumorigenesis of undifferentiated endometrial sarcoma. These molecular changes can help in the diagnosis of endometrial neoplasms, as well as form the basis of molecular targeted therapy.
DNA Vaccines: Developing New Strategies against Cancer
Authors: Fioretti Daniela , Iurescia Sandra , Fazio Vito Michele , Rinaldi Monica
Published: March 2010

Due to their rapid and widespread development, DNA vaccines have entered into a variety of human clinical trials for vaccines against various diseases including cancer. Evidence that DNA vaccines are well tolerated and have an excellent safety profile proved to be of advantage as many clinical trials combines the first phase with the second, saving both time and money. It is clear from the results obtained in clinical trials that such DNA vaccines require much improvement in antigen expression and delivery methods to make them sufficiently effective in the clinic. Similarly, it is clear that additional strategies are required to activate effective immunity against poorly immunogenic tumor antigens. Engineering vaccine design for manipulating antigen presentation and processing pathways is one of the most important aspects that can be easily handled in the DNA vaccine technology. Several approaches have been investigated including DNA vaccine engineering, co-delivery of immunomodulatory molecules, safe routes of administration, prime-boost regimen and strategies to break the immunosuppressive networks mechanisms adopted by malignant cells to prevent immune cell function. Combined or single strategies to enhance the efficacy and immunogenicity of DNA vaccines are applied in completed and ongoing clinical trials, where the safety and tolerability of the DNA platform are substantiated. In this review on DNA vaccines, salient aspects on this topic going from basic research to the clinic are evaluated. Some representative DNA cancer vaccine studies are also discussed.
A Path to the Stars: The Evolution of the Species
Authors: Vitali Fabrizio , Chincarini Guido , Zannoni Mario , Covino Stefano , Molinari Emilio , Benetti Stefano , Bonoli Carlotta , Bortoletto Favio , Cascone Enrico , Cosentino Rosario , D′Alessio Francesco , D′Avanzo Paolo , De Caprio Vincenzo , Della Valle Massimo , Fernandez-Soto Alberto , Fugazza Dino , Giro Enrico , Magrin Demetrio , Malaspina Giuseppe , Mankiewicz Lech , Margutti Raffaella , Mazzoleni Ruben , Nicastro Luciano , Riva Alberto , Riva Marco , Salvaterra Ruben , Spanò Paolo , Sperandio Monica , Stefanon Mauro , Tosti Gino , Testa Vincenzo
Published: March 2010

During the last years, a number of telescopes have been dedicated to the followup of the GRBs. But after the Swift launch, the average observed intensity of the GRBs showed to be lower than thought before. Our experience with the robotic 60 cm REM telescope confirmed this evidence, with a large number of lost GRBs. Then, we proposed to study the feasibility of a 4 m fast pointing class telescope, equipped with a multichannel imagers, from Visible to Near Infrared.
In this paper, we present the main result of the feasibility study we performed so far.
Best Possible Inequalities between Generalized Logarithmic Mean and Classical Means
Authors: Chu Yu-Ming , Long Bo-Yong
Published: March 2010

We answer the question: for α, β, γ ∈ (0,1) with α + β + γ = 1, what are the greatest value p and the least value q, such that the double inequality Lp(a, b) < Aα(a, b)Gβ(a, b)Hγ(a, b) < Lq(a, b) holds for all a, b > 0 with a ≠ b? Here Lp(a, b), A(a, b), G(a, b), and H(a, b) denote the generalized logarithmic, arithmetic, geometric, and harmonic means of two positive numbers a and b, respectively.
Effective and Steady Differentiation of a Clonal Derivative of P19CL6 Embryonal Carcinoma Cell Line into Beating Cardiomyocytes
Authors: Mueller Itsuki , Kobayashi Ryosuke , Nakajima Takayuki , Ishii Maki , Ogawa Kazushige
Published: March 2010

The P19CL6 cell line is a useful model to study cardiac differentiation in vitro. However, large variations were noticed in the differentiation rates among previous reports as well as our individual experiments. To overcome the unstable differentiation, we established P19CL6-A1, a new clonal derivative of P19CL6 that could differentiate into cardiomyocytes more efficiently and stably than the parent using the double stimulation with 5-Aza and DMSO based on the previous report. We also introduced a new software, Visorhythm, that can analyze the temporal variations in the beating rhythms and can chart correlograms displaying the oscillated rhythms. Using P19CL6-A1-derived cardiomyocytes and the software, we demonstrated that the correlograms could clearly display the enhancement of beating rates by cardiotonic reagents. These indicate that a combination of P19CL6-A1 and Visorhythm is a useful tool that can provide invaluable assistance in inotropic drug discovery, drug screening, and toxicity testing.
Long‐Term Damped Dynamics of the Extensible Suspension Bridge
Authors: Bochicchio Ivana , Giorgi Claudio , Vuk Elena
Published: March 2010

This work is focused on the doubly nonlinear equation , whose solutions represent the bending motion of an extensible, elastic bridge suspended by continuously distributed cables which are flexible and elastic with stiffness k2. When the ends are pinned, long‐term dynamics is scrutinized for arbitrary values of axial load p and stiffness k2. For a general external source f, we prove the existence of bounded absorbing sets. When f is time‐independent, the related semigroup of solutions is shown to possess the global attractor of optimal regularity and its characterization is given in terms of the steady states of the problem.
On Nonlinear Boundary Value Problems for Functional Difference Equations with p‐Laplacian
Authors: Wan Yong , Liu Yuji
Published: March 2010

Sufficient conditions for the existence of solutions of nonlinear boundary value
problems for higher‐order functional difference equations with p‐Laplacian are established by making of continuation theorems.
We allow f to be at most linear, superlinear, or sublinear in obtained results.
Inhibition of Toll-Like Receptor 2-Mediated Interleukin-8 Production in Cystic Fibrosis Airway Epithelial Cells via theα7-Nicotinic Acetylcholine Receptor
Authors: Greene Catherine M. , Ramsay Hugh , Wells Robert J. , O'Neill Shane J. , McElvaney Noel G.
Published: March 2010

Cystic Fibrosis (CF) is an inherited disorder characterised by chronic inflammation of the airways. The lung manifestations of CF include colonization withPseudomonas aeruginosaandStaphylococcus aureusleading to neutrophil-dominated airway inflammation and tissue damage. Inflammation in the CF lung is initiated by microbial components which activate the innate immune response via Toll-like receptors (TLRs), increasing airway epithelial cell production of proinflammatory mediators such as the neutrophil chemokine interleukin-8 (IL-8). Thus modulation of TLR function represents a therapeutic approach for CF. Nicotine is a naturally occurring plant alkaloid. Although it is negatively associated with cigarette smoking and cardiovascular damage, nicotine also has anti-inflammatory properties. Here we investigate the inhibitory capacity of nicotine against TLR2- and TLR4-induced IL-8 production by CFTE29o- airway epithelial cells, determine the role ofα7-nAChR (nicotinic acetylcholine receptor) in these events, and provide data to support the potential use of safe nicotine analogues as anti-inflammatories for CF.
Measuring Fine-Scale White-Tailed Deer Movements and Environmental Influences Using GPS Collars
Authors: Webb Stephen L. , Gee Kenneth L. , Strickland Bronson K. , Demarais Stephen , DeYoung Randy W.
Published: March 2010

Few studies have documented fine-scale movements of ungulate species, including white-tailed deer(Odocoileus virginianus), despite the advent of global positioning system (GPS) technology incorporated into tracking devices. We collected fine-scale temporal location estimates (i.e., 15 min/relocation attempt) from 17 female and 15 male white-tailed deer over 7 years and 3 seasons in Oklahoma, USA. Our objectives were to document fine-scale movements of females and males and determine effects of reproductive phase, moon phase, and short-term weather patterns on movements. Female and male movements were primarily crepuscular. Male total daily movements were 20% greater during rut () than postrut (). Female daily movements were greatest during postparturition (), followed by parturition (), and preparturition (). We found moon phase had no effect on daily, nocturnal, and diurnal deer movements and fine-scale temporal weather conditions had an inconsistent influence on deer movement patterns within season. Our data suggest that hourly and daily variation in weather events have minimal impact on movements of white-tailed deer in southern latitudes. Instead, routine crepuscular movements, presumed to maximize thermoregulation and minimize predation risk, appear to be the most important factors influencing movements.
Variational Principles for Multiwalled Carbon Nanotubes Undergoing Vibrations Based on Nonlocal Timoshenko Beam Theory
Authors: Kucuk Ismail , Sadek Ibrahim S. , Adali Sarp
Published: March 2010

Variational principles are derived for multiwalled carbon nanotubes undergoing linear vibrations using the semi‐inverse method with the governing equations based on nonlocal Timoshenko beam theory which takes small scale effects and shear deformation into account. Physical models based on the nonlocal theory approximate the nanoscale phenomenon more accurately than the local theories by taking small scale phenomenon into account. Variational formulation is used to derive the natural and geometric boundary conditions which give a set of coupled boundary conditions in the case of free boundaries which become uncoupled in the case of the local theory. Hamilton′s principle applicable to this case is also given.
Evaluation of In Vitro Activity of Essential Oils againstTrypanosoma brucei bruceiandTrypanosoma evansi
Authors: Habila Nathan , Agbaji Abel S. , Ladan Zakari , Bello Isaac A. , Haruna Emmanuel , Dakare Monday A. , Atolagbe Taofiq O.
Published: March 2010

Essential oils (EOs) fromCymbopogon citratus(CC),Eucalyptus citriodora(EC),Eucalyptus camaldulensis(ED), andCitrus sinensis(CS) were obtained by hydrodistillation process. The EOs were evaluated in vitro for activity againstTrypanosoma brucei brucei(Tbb) andTrypanosoma evansi(T. evansi). The EOs were found to possess antitrypanosomal activity in vitro in a dose-dependent pattern in a short period of time. The drop in number of parasite over time was achieved doses of 0.4 g/ml, 0.2 g/mL, and 0.1 g/mL for all the EOs. The concentration of 0.4 g/mL CC was more potent at 3 minutes and 2 minutes for Tbb andT. evansi, respectively. The GC-MS analysis of the EOs revealed presence of Cyclobutane (96.09%) in CS, 6-octenal (77.11%) in EC, Eucalyptol (75%) in ED, and Citral (38.32%) in CC among several other organic compounds. The results are discussed in relation to trypanosome chemotherapy.
Brain Activation by Peptide Pro-Leu-Gly- (MIF-1)
Authors: Khan Reas S. , Yu Chuanhui , Kastin Abba J. , He Yi , Ehrensing Rudolph H. , Hsuchou Hung , Stone Kirsten Prufer , Pan Weihong
Published: March 2010

MIF-1 (Pro-Leu-Gly-) is a tripeptide for which the therapeutic potential in Parkinson's disease and depression has been indicated by many studies. However, the cellular mechanisms of action of MIF-1 are not yet clear. Here, we show the specific brain regions responsive to MIF-1 treatment by c-Fos mapping, and determine the kinetics of cellular signaling by western blotting of pERK, pSTAT3, and c-Fos in cultured neurons. The immunoreactivity of c-Fos was increased 4 hours after MIF-1 treatment in brain regions critically involved in the regulation of mood, anxiety, depression, and memory. The number of cells activated was greater after peripheral treatment (intravenous delivery) than after intracerebroventricular injection. In cultured SH-SY5Y neuronal cells, c-Fos was induced time- and dose-dependently. The activation of cellular c-Fos was preceded by a transient increase of mitogen-activated protein kinase pERK but a reduction of phosphorylated Signal Transducer and Activator of Transcription (pSTAT3) initially. We conclude that MIF-1 can modulate multiple cellular signals including pERK, and pSTAT3 to activate c-Fos. The cellular activation in specific brain regions illustrates the biochemical and neuroanatomical basis underlying the therapeutic effect of MIF-1 in Parkinson's disease and depression.
Approximated Stiffness Coefficients in Rotor Systems Supported by Bearings with Clearance
Authors: Karlberg Magnus
Published: March 2010

Many kinds of rotating machinery are supported by bearings with clearance, which are further clamped in a supporting structure. When designing such machinery it is important to be able to predict dynamics and hence valid models are needed. Due to gravity, the shaft often vibrates close to a static equilibrium position leading to a possibility to linearise the equation of motion. Although several studies on bearings with clearance exist, there are still no reports on how such clearances affects the stiffness coefficients close to a static equilibrium position. Therefore, analytical expressions for such approximated pedestal stiffness coefficients have been derived in this paper. By using such approximated pedestals in simple rotordynamical models, it was found that the eigenfrequencies decrease significantly with clearance. It is further shown that the approximated pedestal stiffness coefficients only will be valid for vibrations close to the static equilibrium position.
Improvement of Radiation-Mediated Immunosuppression of Human NSCLC Tumour Xenografts in a Nude Rat Model
Authors: Tokalov Sergey V. , Enghardt Wolfgang , Abolmaali Nasreddin
Published: March 2010

Human tumour xenografts in a nude rat model have consistently been used as an essential part of preclinical studies for anticancer drugs activity in human. Commonly, these animals receive whole body irradiation to assure immunosuppression. But whole body dose delivery might be inhomogeneous and the resulting incomplete bone marrow depletion may modify tumour behaviour. To improve irradiation-mediated immunosuppression of human non-small cell lung cancer (NSCLC) xenografts in a nude rat model irradiation (2 + 2 Gy) from opposite sides of animals has been performed using a conventional X-ray tube. The described modification of whole body irradiation improves growth properties of human NSCLC xenografts in a nude rat model. The design of the whole body irradiation mediated immunosuppression described here for NSCLC xenografts may be useful for research applications involving other types of human tumours.
Absorption, Distribution, Excretion, and Pharmacokinetics ofC-Pyronaridine Tetraphosphate in Male and Female Sprague-Dawley Rats
Authors: Park Sang Hyun , Pradeep Kannampalli
Published: March 2010

The main objective of this investigation was to determine the absorption, distribution, excretion, and pharmacokinetics of the antimalarial drug pyronaridine tetraphosphate (PNDP) in Sprague-Dawley rats. Following oral administration of a single dose (10 mg/Kg) ofC-PNDP, it was observed that the drug was readily absorbed from the small intestine within 1 hour following oral administration and was widely distributed in most of the tissues investigated as determined from the observed radioactivity in the tissues. The peak value of the drug in the blood was reached at around 8 hours postadministration, and radioactivity was detected in most of the tissues from 4 hours onwards.C-PNDP showed a poor permeability across the blood-brain barrier, and the absorption, distribution, and excretion ofC-PNDP were found to be gender-independent as both male and female rats showed a similar pattern of radioactivity. Excretion of the drug was predominantly through the urine with a peak excretion post 24 hours of administration. A small amount of the drug was also excreted in the feces and also in the breath. It was found that theCmax, AUC (0-inf), andTmaxvalues were similar to those observed in the Phase II clinical trials of pyronaridine/artesunate (Pyramax) conducted in Uganda.
Effects of Variations in Salt-Spray Conditions on the Corrosion Mechanisms of an AE44 Magnesium Alloy
Authors: Martin Holly J. , Horstemeyer M. F. , Wang Paul T.
Published: March 2010

The understanding of how corrosion affects magnesium alloys is of utmost importance as the automotive and aerospace industries have become interested in the use of these lightweight alloys. However, the standardized salt-spray test does not produce adequate corrosion results when compared with field data, due to the lack of multiple exposure environments. This research explored four test combinations through three sets of cycles to determine how the corrosion mechanisms of pitting, intergranular corrosion, and general corrosion were affected by the environment. Of the four test combinations, Humidity-Drying was the least corrosive, while the most corrosive test condition was Salt Spray-Humidity-Drying. The differences in corrosivity of the test conditions are due to the various reactions needed to cause corrosion, including the presence of chloride ions to cause pit nucleation, the presence of humidity to cause galvanic corrosion, and the drying phase which trapped chloride ions beneath the corrosion by-products.