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Sample records for nanoparticle diclusters bound

  1. Bounds on quantum confinement effects in metal nanoparticles

    Science.gov (United States)

    Blackman, G. Neal; Genov, Dentcho A.

    2018-03-01

    Quantum size effects on the permittivity of metal nanoparticles are investigated using the quantum box model. Explicit upper and lower bounds are derived for the permittivity and relaxation rates due to quantum confinement effects. These bounds are verified numerically, and the size dependence and frequency dependence of the empirical Drude size parameter is extracted from the model. Results suggest that the common practice of empirically modifying the dielectric function can lead to inaccurate predictions for highly uniform distributions of finite-sized particles.

  2. Building high-coverage monolayers of covalently bound magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Mackenzie G.; Teplyakov, Andrew V., E-mail: andrewt@udel.edu

    2016-12-01

    Graphical abstract: - Highlights: • A method for forming a layer of covalently bound nanoparticles is offered. • A nearly perfect monolayer of covalently bound magnetic nanoparticles was formed on gold. • Spectroscopic techniques confirmed covalent binding by the “click” reaction. • The influence of the functionalization scheme on surface coverage was investigated. - Abstract: This work presents an approach for producing a high-coverage single monolayer of magnetic nanoparticles using “click chemistry” between complementarily functionalized nanoparticles and a flat substrate. This method highlights essential aspects of the functionalization scheme for substrate surface and nanoparticles to produce exceptionally high surface coverage without sacrificing selectivity or control over the layer produced. The deposition of one single layer of magnetic particles without agglomeration, over a large area, with a nearly 100% coverage is confirmed by electron microscopy. Spectroscopic techniques, supplemented by computational predictions, are used to interrogate the chemistry of the attachment and to confirm covalent binding, rather than attachment through self-assembly or weak van der Waals bonding. Density functional theory calculations for the surface intermediate of this copper-catalyzed process provide mechanistic insight into the effects of the functionalization scheme on surface coverage. Based on this analysis, it appears that steric limitations of the intermediate structure affect nanoparticle coverage on a flat solid substrate; however, this can be overcome by designing a functionalization scheme in such a way that the copper-based intermediate is formed on the spherical nanoparticles instead. This observation can be carried over to other approaches for creating highly controlled single- or multilayered nanostructures of a wide range of materials to result in high coverage and possibly, conformal filling.

  3. Hybridization thermodynamics of DNA bound to gold nanoparticles

    International Nuclear Information System (INIS)

    Lang, Brian

    2010-01-01

    Isothermal Titration Calorimetry (ITC) was used to study the thermodynamics of hybridization on DNA-functionalized colloidal gold nanoparticles. When compared to the thermodynamics of hybridization of DNA that is free in solution, the differences in the values of the Gibbs free energy of reaction, Δ r G o , the enthalpy, Δ r H o , and entropy, Δ r S o , were small. The change in Δ r G o between the free and bound states was always positive but with statistical significance outside the 95% confidence interval, implying the free DNA is slightly more stable than when in the bound state. Additionally, ITC was also able to reveal information about the binding stoichiometry of the hybridization reactions on the DNA-functionalized gold nanoparticles, and indicates that there is a significant fraction of the DNA on gold nanoparticle surface that is unavailable for DNA hybridization. Furthermore, the fraction of available DNA is dependent on the spacer group on the DNA that is used to span the gold surface from that to the probe DNA.

  4. UV-Visible Spectroscopy-Based Quantification of Unlabeled DNA Bound to Gold Nanoparticles.

    Science.gov (United States)

    Baldock, Brandi L; Hutchison, James E

    2016-12-20

    DNA-functionalized gold nanoparticles have been increasingly applied as sensitive and selective analytical probes and biosensors. The DNA ligands bound to a nanoparticle dictate its reactivity, making it essential to know the type and number of DNA strands bound to the nanoparticle surface. Existing methods used to determine the number of DNA strands per gold nanoparticle (AuNP) require that the sequences be fluorophore-labeled, which may affect the DNA surface coverage and reactivity of the nanoparticle and/or require specialized equipment and other fluorophore-containing reagents. We report a UV-visible-based method to conveniently and inexpensively determine the number of DNA strands attached to AuNPs of different core sizes. When this method is used in tandem with a fluorescence dye assay, it is possible to determine the ratio of two unlabeled sequences of different lengths bound to AuNPs. Two sizes of citrate-stabilized AuNPs (5 and 12 nm) were functionalized with mixtures of short (5 base) and long (32 base) disulfide-terminated DNA sequences, and the ratios of sequences bound to the AuNPs were determined using the new method. The long DNA sequence was present as a lower proportion of the ligand shell than in the ligand exchange mixture, suggesting it had a lower propensity to bind the AuNPs than the short DNA sequence. The ratio of DNA sequences bound to the AuNPs was not the same for the large and small AuNPs, which suggests that the radius of curvature had a significant influence on the assembly of DNA strands onto the AuNPs.

  5. Substrate-bound tyrosinase electrode using gold nanoparticles anchored to pyrroloquinoline quinone for a pesticide biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, G.Y.; Kang, M.S.; Shim, J.; Moon, S.H. [Gwangju Inst. of Science and Technology (Korea, Republic of). Dept. of Environmental Science and Engineering

    2008-07-01

    Enzyme electrodes are now being considered for use in the detection of pesticides. However, the electrodes do not have the sensitivity to detect low concentration pesticides, and external substrates are needed to measure changes in enzyme activity. This study discussed a chemical species designed to mimic a substrate in the preparation of a tyrosinase (TYR) electrode for use without substrate standard solutions. Pyrroloquinolone quinone (PQQ) was integrated within the tyrosinase electrode and used as an assimilated substrate for measuring the pesticide. Gold (Au) nanoparticles were also used to detect low concentration pesticides. The TYR was immobilized on the PQQ-anchored Au nanoparticles by a covalent bond. The tethered PQQ was then reduced by obtaining 2-electrons from the electrode. The study showed that the substrate-bound enzyme electrode can be used to detect pesticide without a substrate standard solution through the immobilization of the enzyme and the substrate on the Au nanoparticles.

  6. Magnetic stents retain nanoparticle-bound antirestenotic drugs transported by lipid microbubbles.

    Science.gov (United States)

    Räthel, T; Mannell, H; Pircher, J; Gleich, B; Pohl, U; Krötz, F

    2012-05-01

    Coating coronary stents with antirestenotic drugs revolutionized interventional cardiology. We developed a system for post-hoc drug delivery to uncoated stents. We coupled rapamycin or a chemically similar fluorescent dye to superparamagnetic nanoparticles. The antiproliferative activity of rapamycin coupled to nanoparticles was confirmed in vitro in primary porcine vascular cells. The particles were then incorporated into lipid based microbubbles. Commercially available stents were made magnetizable by nickel plating and used to induce strong field gradients in order to capture magnetic microbubbles from flowing liquids when placed in an external magnetic field. Nanoparticle bound Rapamycin dose dependently inhibited cell proliferation in vitro. Magnetic microcbubbles carrying coated nanoparticles were caught by magnets placed external to a flow-through tube. Plating commercial stents with nickel resulted in increased deposition at stent struts and allowed for widely increased distance of external magnets. Deposition depended on circulation time and velocity and distance of magnets. Deposited microbubbles were destroyed by ultrasound and delivered their cargo to targeted sites. Drugs can be incorporated into nanoparticle loaded microbubbles and thus be delivered to magnetizable stents from circulating fluids by applying external magnetic fields. This technology could allow for post-hoc drug coating of already implanted vascular stents.

  7. "Cloud" assemblies: quantum dots form electrostatically bound dynamic nebulae around large gold nanoparticles.

    Science.gov (United States)

    Lilly, G Daniel; Lee, Jaebeom; Kotov, Nicholas A

    2010-10-14

    Dynamic self-assembled structures of nanoparticles can be produced using predominantly electrostatic interactions. Such assemblies were made from large, positively charged Au metal nanoparticles surrounded by an electrostatically bound cloud of smaller, negatively charged CdSe/ZnS or CdTe quantum dots. At low concentrations they are topologically similar to double electric layers of ions and corona-like assemblies linked by polymer chains. They can also be compared to the topological arrangement of some planetary systems in space. The great advantages of the cloud assemblies are (1) their highly dynamic nature compared to more rigid covalently bound assemblies, (2) simplicity of preparation, and (3) exceptional versatility in components and resulting optical properties. Photoluminescence intensity enhancement originating from quantum resonance between excitons and plasmons was observed for CdSe/ZnS quantum dots, although CdTe dots displayed emission quenching. To evaluate more attentively their dynamic behavior, emission data were collected for the cloud-assemblies with different ratios of the components and ionic strengths of the media. The emission of the system passes through a maximum for 80 QDs ∶ 1 Au NP as determined by the structure of the assemblies and light absorption conditions. Ionic strength dependence of luminescence intensity contradicts the predictions based on the Gouy-Chapman theory and osmotic pressure at high ionic strengths due to formation of larger chaotic colloidally stable assemblies. "Cloud" assemblies made from different nanoscale components can be used both for elucidation of most fundamental aspects of nanoparticle interactions, as well as for practical purposes in sensing and biology.

  8. Versatile gradients of chemistry, bound ligands and nanoparticles on alumina nanopore arrays

    International Nuclear Information System (INIS)

    Michelmore, Andrew; Poh, Zihan; Goreham, Renee V; Short, Robert D; Vasilev, Krasimir; Mierczynska, Agnieszka; Losic, Dusan

    2011-01-01

    Nanoporous alumina (PA) arrays produced by self-ordering growth, using electrochemical anodization, have been extensively explored for potential applications based upon the unique thermal, mechanical and structural properties, and high surface-to-volume ratio of these materials. However, the potential applications and functionality of these materials may be further extended by molecular-level engineering of the surface of the pore rims. In this paper we present a method for the generation of chemical gradients on the surface of PA arrays based upon plasma co-polymerization of two monomers. We further extend these chemical gradients, which are also gradients of surface charge, to those of bound ligands and number density gradients of nanoparticles. The latter represent a highly exotic new class of materials, comprising aligned PA, capped by gold nanoparticles around the rim of the pores. Gradients of chemistry, ligands and nanoparticles generated by our method retain the porous structure of the substrate, which is important in applications that take advantage of the inherent properties of these materials. This method can be readily extended to other porous materials.

  9. Versatile gradients of chemistry, bound ligands and nanoparticles on alumina nanopore arrays

    Energy Technology Data Exchange (ETDEWEB)

    Michelmore, Andrew; Poh, Zihan; Goreham, Renee V; Short, Robert D; Vasilev, Krasimir [Mawson Institute, University of South Australia, Mawson Lakes, SA 5095, Adelaide (Australia); Mierczynska, Agnieszka; Losic, Dusan, E-mail: Krasimir.vasilev@unisa.edu.au [Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA 5095, Adelaide (Australia)

    2011-10-14

    Nanoporous alumina (PA) arrays produced by self-ordering growth, using electrochemical anodization, have been extensively explored for potential applications based upon the unique thermal, mechanical and structural properties, and high surface-to-volume ratio of these materials. However, the potential applications and functionality of these materials may be further extended by molecular-level engineering of the surface of the pore rims. In this paper we present a method for the generation of chemical gradients on the surface of PA arrays based upon plasma co-polymerization of two monomers. We further extend these chemical gradients, which are also gradients of surface charge, to those of bound ligands and number density gradients of nanoparticles. The latter represent a highly exotic new class of materials, comprising aligned PA, capped by gold nanoparticles around the rim of the pores. Gradients of chemistry, ligands and nanoparticles generated by our method retain the porous structure of the substrate, which is important in applications that take advantage of the inherent properties of these materials. This method can be readily extended to other porous materials.

  10. Nanoparticle Albumin-Bound-Paclitaxel in the Treatment of Metastatic Urethral Adenocarcinoma: The Significance of Molecular Profiling and Targeted Therapy

    Directory of Open Access Journals (Sweden)

    Yasmin M. Abaza

    2014-01-01

    Full Text Available Primary urethral cancer is rare and accounts for only 0.003% of all malignancies arising from the female genitourinary tract. Due to the rarity of this disease, no consensus exists regarding the optimal therapeutic approach. Nanoparticle albumin-bound-paclitaxel has been shown to be effective in the treatment of a number of malignancies including metastatic breast, pancreatic, and bladder cancer. We present a 67-year-old woman with advanced metastatic urethral adenocarcinoma resistant to two lines of chemotherapy (ifosfamide/paclitaxel/cisplatin and irinotecan/5-fluorouracil/leucovorin that showed a dramatic response to nanoparticle albumin-bound-paclitaxel. This is the first case report to document the use and efficacy of nanoparticle albumin-bound-paclitaxel in the treatment of unresectable metastatic urethral cancer.

  11. Effect of pullulan nanoparticle surface charges on HSA complexation and drug release behavior of HSA-bound nanoparticles.

    Directory of Open Access Journals (Sweden)

    Xiaojun Tao

    Full Text Available Nanoparticle (NP compositions such as hydrophobicity and surface charge are vital to determine the presence and amount of human serum albumin (HSA binding. The HSA binding influences drug release, biocompatibility, biodistribution, and intercellular trafficking of nanoparticles (NPs. Here, we prepared 2 kinds of nanomaterials to investigate HSA binding and evaluated drug release of HSA-bound NPs. Polysaccharides (pullulan carboxyethylated to provide ionic derivatives were then conjugated to cholesterol groups to obtain cholesterol-modified carboxyethyl pullulan (CHCP. Cholesterol-modified pullulan (CHP conjugate was synthesized with a similar degree of substitution of cholesterol moiety to CHCP. CHCP formed self-aggregated NPs in aqueous solution with a spherical structure and zeta potential of -19.9 ± 0.23 mV, in contrast to -1.21 ± 0.12 mV of CHP NPs. NPs could quench albumin fluorescence intensity with maximum emission intensity gradually decreasing up to a plateau at 9 to 12 h. Binding constants were 1.12 × 10(5 M(-1 and 0.70 × 10(5 M(-1 to CHP and CHCP, respectively, as determined by Stern-Volmer analysis. The complexation between HSA and NPs was a gradual process driven by hydrophobic force and inhibited by NP surface charge and shell-core structure. HSA conformation was altered by NPs with reduction of α-helical content, depending on interaction time and particle surface charges. These NPs could represent a sustained release carrier for mitoxantrone in vitro, and the bound HSA assisted in enhancing sustained drug release.

  12. Particles size distribution effect on 3D packing of nanoparticles in to a bounded region

    International Nuclear Information System (INIS)

    Farzalipour Tabriz, M.; Salehpoor, P.; Esmaielzadeh Kandjani, A.; Vaezi, M. R.; Sadrnezhaad, S. K.

    2007-01-01

    In this paper, the effects of two different Particle Size Distributions on packing behavior of ideal rigid spherical nanoparticles using a novel packing model based on parallel algorithms have been reported. A mersenne twister algorithm was used to generate pseudo random numbers for the particles initial coordinates. Also, for this purpose a nano sized tetragonal confined container with a square floor (300 * 300 nm) were used in this work. The Andreasen and the Lognormal Particle Size Distributions were chosen to investigate the packing behavior in a 3D bounded region. The effects of particle numbers on packing behavior of these two Particle Size Distributions have been investigated. Also the reproducibility and the distribution of packing factor of these Particle Size Distributions were compared

  13. Nanoparticle albumin-bound paclitaxel: a novel Cremphor-EL-free formulation of paclitaxel.

    Science.gov (United States)

    Stinchcombe, Thomas E

    2007-08-01

    Standard formulation paclitaxel requires the use of solvents, such as Cremphor-EL, which contribute to some of the toxicities commonly associated with paclitaxel-based therapy. Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) is a novel solvent-free formulation of paclitaxel. The formulation is prepared by high-pressure homogenization of paclitaxel in the presence of serum albumin into a nanoparticle colloidal suspension. The human albumin-stabilized paclitaxel particles have an average size of 130 nm. Nab-paclitaxel has several practical advantages over Cremphor-EL-paclitaxel, including a shorter infusion time (30 min) and no need for premedications for hypersensitivity reactions. The nab-paclitaxel formulation eliminates the impact of Cremphor-EL on paclitaxel pharmacokinetics and utilizes the endogenous albumin transport mechanisms to concentrate nab-paclitaxel within the tumor. A recent Phase III trial compared nab- and Cremphor-EL-paclitaxel in patients with metastatic breast cancer. Patients treated with nab-paclitaxel experienced a higher response, longer time to tumor progression and, in patients receiving second-line or greater therapy, a longer median survival. Patients treated with nab-paclitaxel had a significantly lower rate of severe neutropenia and a higher rate of sensory neuropathy. The preclinical and clinical data indicate that the nab-paclitaxel formulation has significant advantages over Cremphor-EL-paclitaxel.

  14. Isatis tinctoria mediated synthesis of amphotericin B-bound silver nanoparticles with enhanced photoinduced antileishmanial activity: A novel green approach.

    Science.gov (United States)

    Ahmad, Aftab; Wei, Yun; Syed, Fatima; Khan, Shafiullah; Khan, Gul Majid; Tahir, Kamran; Khan, Arif Ullah; Raza, Muslim; Khan, Faheem Ullah; Yuan, Qiping

    2016-08-01

    After malaria, Leishmaniasis is the most prevalent infectious disease in terms of fatality and geographical distribution. The availability of a limited number of antileishmanial agents, emerging resistance to the available drugs, and the high cost of treatment complicate the treatment of leishmaniasis. To overcome these issues, critical research for new therapeutic agents with enhanced antileishmanial potential and low treatment cost is needed. In this contribution, we developed a green protocol to prepare biogenic silver nanoparticles (AgNPs) and amphotericin B-bound biogenic silver nanoparticles (AmB-AgNPs). Phytochemicals from the aqueous extract of Isatis tinctoria were used as reducing and capping agents to prepare silver nanoparticles. Amphotericin B was successfully adsorbed on the surface of biogenic silver nanoparticles. The prepared nanoparticles were characterized by various analytical techniques. UV-Visible spectroscopy was employed to detect the characteristic localized surface plasmon resonance peaks (LSPR) for the prepared nanoparticles. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) studies revealed the formation of spherical silver nanoparticles with an average particle size of 10-20nm. The cubic crystalline structure of the prepared nanoparticles was confirmed by X-ray diffraction (XRD) study. FTIR spectroscopic analysis revealed that plant polyphenolic compounds are mainly involved in metal reduction and capping. Under visible light irradiation, biogenic silver nanoparticles exhibited significant activity against Leishmania tropica with an IC50 value of 4.2μg/mL. The leishmanicidal activity of these nanoparticles was considerably enhanced by conjugation with amphotericin B (IC50=2.43μg/mL). In conclusion, the findings of this study reveal that adsorption of amphotericin B, an antileishmanial drug, to biogenic silver nanoparticles, could be a safe, more effective and economic alternative to the available

  15. Nanoparticle albumin-bound (nab-paclitaxel for the treatment of pancreas ductal adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Narayanan V

    2015-01-01

    Full Text Available Vignesh Narayanan,1 Colin D Weekes1,2 1Division of Medical Oncology, Department of Medicine, 2Developmental Therapeutics Program, University of Colorado Cancer Center, University of Colorado School of Medicine, Aurora, CO, USA Abstract: Pancreatic adenocarcinoma is a leading cause of cancer-related mortality worldwide, and surgical resection offers the only chance of cure. Since the majority of patients have unresectable disease at presentation, the emphasis has been on identifying effective chemotherapy regimens to prolong survival and control tumor burden. Gemcitabine has been the cornerstone of treatment ever since it was discovered to be an active agent in advanced pancreatic cancer nearly two decades ago, but the overall prognosis in patients with metastatic disease remains dismal. A dense fibrotic stroma around the tumor devoid of vasculature and the resultant hypoxic tumor microenvironment are implicated in the chemotherapy-resistant nature of this malignancy. In recent years, a growing body of literature has further elucidated several aspects of pancreatic tumor biology, such as its ability to utilize albumin from the peritumoral tissues to support its metabolic needs. High-pressure homogenization of paclitaxel with nanoparticle albumin results in the formation of soluble 130 nm complexes with albumin acting as the carrier for the otherwise hydrophobic paclitaxel. Once these complexes reach the tumor milieu, they act by depleting the tumor stroma. In addition, paclitaxel is also transported into the tumor cell along with albumin, where it then exerts its antineoplastic activity. Nanoparticle albumin-bound (nab-paclitaxel also increases gemcitabine levels inside the tumor cells by inhibiting cytidine deaminase, the enzyme that degrades gemcitabine. This review focuses on proposed mechanisms of efficacy of nab-paclitaxel in pancreatic cancer and discusses the preclinical and clinical studies of relevance. Keywords: pancreatic

  16. Penicillin-Bound Polyacrylate Nanoparticles: Restoring the Activity of β-Lactam Antibiotics Against MRSA

    OpenAIRE

    Turos, Edward; Reddy, G. Suresh Kumar; Greenhalgh, Kerriann; Ramaraju, Praveen; Abeylath, Sampath C.; Jang, Seyoung; Dickey, Sonja; Lim, Daniel V.

    2007-01-01

    This report describes the preparation of antibacterially-active emulsified polyacrylate nanoparticles in which a penicillin antibiotic is covalently conjugated onto the polymeric framework. These nanoparticles were prepared in water by emulsion polymerization of an acrylated penicillin analogue pre-dissolved in a 7:3 (w:w) mixture of butyl acrylate and styrene in the presence of sodium dodecyl sulfate (surfactant) and potassium persulfate (radical initiator). Dynamic light scattering analysis...

  17. Chemical exchange saturation transfer (CEST) properties of albumin-binding and gold nanoparticle-bound Eu (III) chelates

    Science.gov (United States)

    Melendez, Milleo Dalmacio

    CEST agents derived from paramagnetic complexes, commonly referred to as PARACEST agents represent a new class of MRI contrast agents that respond to biological information such as pH, temperature, redox, and metabolite levels. In this work, CEST properties of two novel PARACEST agents were investigated upon binding to human serum albumin (HSA) and conjugation to gold nanoparticles (Au NPs). CEST properties of [EuDOTA(O-Et-Tyr)4] -when bound to HSA was studied to address the effect of proteins on CEST. The interaction of this Eu3+ complex to HSA was investigated by performing fluorescent probe displacement studies and it was found to bind HSA at two different binding pockets, the normal warfarin and dansyl glycine binding sites. The lipophilic pendant arms and the negative charge of this complex contribute to the favorable protein binding. However, the CEST signal was reduced 2-fold upon binding to HSA. The exchangeable protons on HSA provide a large proton pool that can exchange with the bound H 2O, competing for the exchange between bulk and bound water. Au NPs coated with [EuDOTA(CAM)4]3+ were prepared using the Brust method and characterized by measuring the CEST properties. The water residence lifetime for the Au-Eu NP conjugates increased 2-fold compared to the free Eu3+ complex presumably, as a result of the formation of hindered structure between the particle and the Eu3+ complex. Sensitivity enhancement in CEST was achieved by slowing down water exchange and increasing the number of exchangeable groups on the agent using Au-Eu NP conjugates. The CEST properties of small molecule PARACEST agents were shown to vary depending on the platform used in assembling larger adducts.

  18. Covalently bound DNA on naked iron oxide nanoparticles: Intelligent colloidal nano-vector for cell transfection.

    Science.gov (United States)

    Magro, Massimiliano; Martinello, Tiziana; Bonaiuto, Emanuela; Gomiero, Chiara; Baratella, Davide; Zoppellaro, Giorgio; Cozza, Giorgio; Patruno, Marco; Zboril, Radek; Vianello, Fabio

    2017-11-01

    Conversely to common coated iron oxide nanoparticles, novel naked surface active maghemite nanoparticles (SAMNs) can covalently bind DNA. Plasmid (pDNA) harboring the coding gene for GFP was directly chemisorbed onto SAMNs, leading to a novel DNA nanovector (SAMN@pDNA). The spontaneous internalization of SAMN@pDNA into cells was compared with an extensively studied fluorescent SAMN derivative (SAMN@RITC). Moreover, the transfection efficiency of SAMN@pDNA was evaluated and explained by computational model. SAMN@pDNA was prepared and characterized by spectroscopic and computational methods, and molecular dynamic simulation. The size and hydrodynamic properties of SAMN@pDNA and SAMN@RITC were studied by electron transmission microscopy, light scattering and zeta-potential. The two nanomaterials were tested by confocal scanning microscopy on equine peripheral blood-derived mesenchymal stem cells (ePB-MSCs) and GFP expression by SAMN@pDNA was determined. Nanomaterials characterized by similar hydrodynamic properties were successfully internalized and stored into mesenchymal stem cells. Transfection by SAMN@pDNA occurred and GFP expression was higher than lipofectamine procedure, even in the absence of an external magnetic field. A computational model clarified that transfection efficiency can be ascribed to DNA availability inside cells. Direct covalent binding of DNA on naked magnetic nanoparticles led to an extremely robust gene delivery tool. Hydrodynamic and chemical-physical properties of SAMN@pDNA were responsible of the successful uptake by cells and of the efficiency of GFP gene transfection. SAMNs are characterized by colloidal stability, excellent cell uptake, persistence in the host cells, low toxicity and are proposed as novel intelligent DNA nanovectors for efficient cell transfection. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Surface-Bound Ligands Modulate Chemoselectivity and Activity of a Bimetallic Nanoparticle Catalyst

    KAUST Repository

    Vu, Khanh B.

    2015-04-03

    "Naked" metal nanoparticles (NPs) are thermodynamically and kinetically unstable in solution. Ligands, surfactants, or polymers, which adsorb at a particle\\'s surface, can be used to stabilize NPs; however, such a mode of stabilization is undesirable for catalytic applications because the adsorbates block the surface active sites. The catalytic activity and the stability of NPs are usually inversely correlated. Here, we describe an example of a bimetallic (PtFe) NP catalyst stabilized by carboxylate surface ligands that bind preferentially to one of the metals (Fe). NPs stabilized by fluorous ligands were found to be remarkably competent in catalyzing the hydrogenation of cinnamaldehyde; NPs stabilized by hydrocarbon ligands were significantly less active. The chain length of the fluorous ligands played a key role in determining the chemoselectivity of the FePt NP catalysts. (Chemical Presented). © 2015 American Chemical Society.

  20. Facile one-pot formulation of TRAIL-embedded paclitaxel-bound albumin nanoparticles for the treatment of pancreatic cancer.

    Science.gov (United States)

    Min, Sun Young; Byeon, Hyeong Jun; Lee, Changkyu; Seo, Jisoo; Lee, Eun Seong; Shin, Beom Soo; Choi, Han-Gon; Lee, Kang Choon; Youn, Yu Seok

    2015-10-15

    Nanoparticle albumin-bound (nab™) technology is an effective way of delivering hydrophobic chemotherapeutics. We developed a one-pot/one-step formulation of paclitaxel (PTX)-bound albumin nanoparticles with embedded tumor necrosis factor-related apoptosis-inducing ligand (TRAIL/PTX HSA-NP) for the treatment of pancreatic cancer. TRAIL/PTX HSA-NPs were fabricated using a high-pressure homogenizer at a TRAIL feeding ratio of 0.2%, 1.0%, and 2.0%. TRAIL/PTX HSA-NPs were spherical and became larger in size (170-230 nm) with increasing TRAIL amount (0.2-2.0%). The loading efficiencies of PTX were in the range of ∼86.4% and significantly low at 2.0% TRAIL (60.4%). Specifically, the inhibitory concentrations (IC50) of TRAIL (1.0 or 2.0%)/PTX HSA-NPs were >20-fold lower than that of plain PTX-HSA NP (0.032±0.06, 0.022±0.005, and 0.96±0.15 ng/ml, respectively) in pancreatic Mia Paca-2 cells. Considering TRAIL loading, bioactivity, and particle size, TRAIL(1.0%)/PTX HSA-NPs were determined as the optimal candidate for further studies. TRAIL(1.0%)/PTX HSA-NPs displayed substantially greater apoptotic activity than plain PTX HSA-NP in both FACS and TUNEL analysis. The loaded PTX and TRAIL were gradually released from the TRAIL(1.0%)/PTX HSA-NPs until ∼24 h, which is considered to be a sufficient time for delivery to the tumor tissue. TRAIL(1.0%)/PTX HSA-NP displayed markedly more antitumor efficacy than plain PTX HSA-NP in Mia Paca-2 cell-xenografted mice in terms of tumor volume (size) and weight (213.9 mm(3) and 0.18 g vs. 1126.8 mm(3) and 0.80 g, respectively). These improved in vitro and in vivo performances were due to the combined synergistic effects of PTX and TRAIL. We believe that this TRAIL/PTX HSA-NP would have potential as a novel apoptosis-based anticancer agent. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Nanoparticle albumin-bound paclitaxel combined with cisplatin as the first-line treatment for metastatic esophageal squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Shi Y

    2013-05-01

    Full Text Available Yan Shi, Rui Qin, Zhi-Kuan Wang, Guang-Hai DaiDepartment of Multimodality Therapy of Oncology, General Hospital of CPLA, Beijing, People's Republic of ChinaAbstract: Esophageal cancer is a major health hazard in many parts of the world and is often diagnosed late. The objective of this study was to explore the efficacy and safety of nanoparticle albumin-bound paclitaxel (Nab-PTX combined with cisplatin (DDP in patients with metastatic esophageal squamous cell carcinoma (ESCC. Patients with histologically confirmed ESCC were treated with Nab-PTX 250 mg/m2 and DDP 75 mg/m2 intravenously on day 1, every 21 days. Evaluation was performed after every two cycles of therapy and the therapy was continued until disease progression or unacceptable toxicity. From April 2010 to December 2012, 33 patients were enrolled. Ten patients had recurrent and metastatic tumors after surgery and 23 patients were diagnosed with unresectable metastatic disease. Patients received a median of four cycles of therapy (ranging from two to six cycles. Twenty patients achieved partial response and nine patients achieved stable disease; no complete response was observed. The objective response rate was 60.6% and the disease control rate was 87.9%. The median progression-free survival was 6.2 months (95% confidence interval: 4.0 to 8.4 months and the median overall survival was 15.5 months (95% CI: 7.6 to 23.4 months. Only four patients experienced grade 3 adverse events, including vomiting, neutropenia, and sensory neuropathy. The most common adverse events were nausea/vomiting (81.8%, neutropenia (63.6%, leucopenia (48.5%, anemia (24.2% and sensory neuropathy (24.2%. In conclusion, the combination of Nab-PTX and DDP is a highly effective and well-tolerated first-line treatment in metastatic ESCC.Keywords: esophageal squamous cell carcinoma, nanoparticle albumin-bound paclitaxel, chemotherapy, metastasis

  2. Nanoparticle albumin-bound paclitaxel as neoadjuvant chemotherapy of breast cancer: a systematic review and meta-analysis.

    Science.gov (United States)

    Zong, Yu; Wu, Jiayi; Shen, Kunwei

    2017-03-07

    The value of nanoparticle albumin-bound paclitaxel (nab-paclitaxel) in neoadjuvant systemic therapy for breast cancer remains uncertain. Both electronic databases and proceedings of oncologic meetings were included in systematic literature search. Pooled rates of pathological complete response (pCR), odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed-effect or random-effect model to determine the effect of neoadjuvant nab-paclitaxel. Twenty-one studies with 2357 patients were included, 3 of which were randomized clinical trials. The aggregate pCR(ypT0/is ypN0) rate was 32% (95% CI 25-38%) in unselected breast cancer patients and variated in different subtypes. Within randomized clinical trials, the probability of achieving pCR was significantly higher in the nab-paclitaxel group than in the conventional taxanes group (OR = 1.383, 95%CI 1.141-1.676, p = 0.001). For non-hematological toxic effect, any grade and grade 3-4 peripheral sensory neuropathy occurred more frequently with nab-paclitaxel compared to paclitaxel (any grade, OR = 2.090, 95%CI 1.016-4.302, p = 0.045; grade3-4, OR = 3.766, 95%CI 2.324-6.100, p < 0.001). Hypersensitivity was more common with paclitaxel than nab-paclitaxel at any grade and grade 3-4. nab-paclitaxel is an effective cytotoxic drug in neoadjuvant treatment of breast cancer, especially for aggressive tumors in terms of pCR. Exchange of nab-paclitaxel for conventional taxanes could significantly improve pCR rate with reasonable toxicities.

  3. Electron transfer dynamics of triphenylamine dyes bound to TiO2 nanoparticles from femtosecond stimulated Raman spectroscopy

    KAUST Repository

    Hoffman, David P.; Lee, Olivia P.; Millstone, Jill E.; Chen, Mark S.; Su, Timothy A.; Creelman, Mark; Frechet, Jean; Mathies, Richard A.

    2013-01-01

    Interfacial electron transfer between sensitizers and semiconducting nanoparticles is a crucial yet poorly understood process. To address this problem, we have used transient absorption (TA) and femtosecond stimulated Raman spectroscopy (FSRS

  4. A silica nanoparticle-based sensor for selective fluorescent detection of homocysteine via interaction differences between thiols and particle-surface-bound polymers

    International Nuclear Information System (INIS)

    Yu Changmin; Zeng Fang; Luo Ming; Wu Shuizhu

    2012-01-01

    Biothiols play crucial roles in maintaining biological systems; among them, homocysteine (Hcy) has received increasing attention since elevated levels of Hcy have been implicated as an independent risk factor for cardiovascular disease. Hence, the selective detection of this specific biothiol, which is a disease-associated biomarker, is very important. In this paper, we demonstrate a new mesoporous silica nanoparticle-based sensor for selective detection of homocysteine from biothiols and other common amino acids. In this fluorescent sensing system, an anthracene nitroolefin compound was placed inside the mesopores of mesoporous silica nanoparticles (MSNs) and used as a probe for thiols. The hydrophilic polyethylene glycol (PEG 5000) molecules were covalently bound to the MSN surface and used as a selective barrier for Hcy detection via different interactions between biothiols and the PEG polymer chains. The sensor can discriminate Hcy from the two low-molecular mass biothiols (GSH and Cys) and other common amino acids in totally aqueous media as well as in serum, with a detection limit of 0.1 μM. This strategy may offer an approach for designing other MSN-based sensing systems by using polymers as diffusion regulators in sensing assays for other analytes. (paper)

  5. Influence of the Debye length on the interaction of a small molecule-modified Au nanoparticle with a surface-bound bioreceptor.

    Science.gov (United States)

    Bukar, Natalia; Zhao, Sandy Shuo; Charbonneau, David M; Pelletier, Joelle N; Masson, Jean-Francois

    2014-05-18

    We report that a shorter Debye length and, as a consequence, decreased colloidal stability are required for the molecular interaction of folic acid-modified Au nanoparticles (Au NPs) to occur on a surface-bound receptor, human dihydrofolate reductase (hDHFR). The interaction measured using surface plasmon resonance (SPR) sensing was optimal in a phosphate buffer at pH 6 and ionic strength exceeding 300 mM. Under these conditions, the aggregation constant of the Au NPs was approximately 10(4) M(-1) s(-1) and the Debye length was below 1 nm, on the same length scale as the size of the folate anion (approximately 0.8 nm). Longer Debye lengths led to poorer SPR responses, revealing a reduced affinity of the folic acid-modified Au NPs for hDHFR. While high colloidal stability of Au NPs is desired in most applications, these conditions may hinder molecular interactions due to Debye lengths exceeding the size of the ligand and thus preventing close interactions with the surface-bound molecular receptor.

  6. Electron transfer dynamics of triphenylamine dyes bound to TiO2 nanoparticles from femtosecond stimulated Raman spectroscopy

    KAUST Repository

    Hoffman, David P.

    2013-04-11

    Interfacial electron transfer between sensitizers and semiconducting nanoparticles is a crucial yet poorly understood process. To address this problem, we have used transient absorption (TA) and femtosecond stimulated Raman spectroscopy (FSRS) to investigate the photoexcited dynamics of a series of triphenylamine-coumarin dye/TiO2 conjugates. The TA decay is multiexponential, spanning time scales from 100 fs to 100 ps, while the characteristic transient Raman spectrum of the radical cation decays biexponentially with a dominant ∼3 ps component. To explain these observations, we propose a model in which the decay of the TA is due to hot electrons migrating from surface trap states to the conduction band of TiO 2 while the decay of the Raman signature is due to internal conversion of the dye molecule. Furthermore, the S1 Raman spectrum of TPAC3, a dye wherein a vinyl group separates the triphenylamine and coumarin moieties, is similar to the S1 Raman spectrum of trans-stilbene; we conclude that their S1 potential energy surfaces and reactivity are also similar. This correlation suggests that dyes containing vinyl linkers undergo photoisomerization that competes with electron injection. © 2013 American Chemical Society.

  7. Safety and Efficacy of Low-dose Nanoparticle Albumin-bound Paclitaxel for HER2-negative Metastatic Breast Cancer.

    Science.gov (United States)

    Takashima, Tsutomu; Kawajiri, Hidemi; Nishimori, Takeo; Tei, Seika; Nishimura, Shigehiko; Yamagata, Shigehito; Tokunaga, Shinya; Mizuyama, Yoko; Sunami, Takeshi; Tezuka, Kenji; Ikeda, Katsumi; Ogawa, Yoshinari; Kashiwagi, Shinichiro; Noda, Satoru; Onoda, Naoyoshi; Ishikawa, Tetsuro; Kudoh, Shinzoh; Takada, Minoru; Hirakawa, Kosei; Ohira, Masaichi

    2018-01-01

    Nab-paclitaxel (nab-PTX) is an albumin-bound paclitaxel formulation. Although nab-PTX has shown superior efficacy compared to conventional paclitaxel (PTX) in metastatic breast cancer (MBC), chemotherapy-induced peripheral neuropathy (CIPN) was more frequently observed in nab-PTX. In this study, we aimed to estimate the feasibility of the nab-PTX 175 mg/m 2 /3weeks regimen. Patients having metastatic or inoperable HER2-negative breast cancer received 175 mg/m 2 of nab-PTX every three weeks. The primary endpoint was safety and the secondary endpoints were response and survival. Seventeen patients were enrolled with a median age of 64 years. Ten patients had estrogen receptor positive disease and seven had triple-negative disease. CIPN was observed in seven patients (41%) however, grade 3 CIPN was only seen in one patient (6%). Objective response rate was 41% and progression-free survival was 23 weeks. Nab-PTX 175 mg/m 2 /3wks regimen has a good safety profile and less frequent CIPN. This regimen can contribute to the strategy of MBC treatment. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  8. Improved anticancer effects of albumin-bound paclitaxel nanoparticle via augmentation of EPR effect and albumin-protein interactions using S-nitrosated human serum albumin dimer.

    Science.gov (United States)

    Kinoshita, Ryo; Ishima, Yu; Chuang, Victor T G; Nakamura, Hideaki; Fang, Jun; Watanabe, Hiroshi; Shimizu, Taro; Okuhira, Keiichiro; Ishida, Tatsuhiro; Maeda, Hiroshi; Otagiri, Masaki; Maruyama, Toru

    2017-09-01

    In the latest trend of anticancer chemotherapy research, there were many macromolecular anticancer drugs developed based on enhanced permeability and retention (EPR) effect, such as albumin bound paclitaxel nanoparticle (nab- PTX, also called Abraxane ® ). However, cancers with low vascular permeability posed a challenge for these EPR based therapeutic systems. Augmenting the intrinsic EPR effect with an intrinsic vascular modulator such as nitric oxide (NO) could be a promising strategy. S-nitrosated human serum albumin dimer (SNO-HSA Dimer) shown promising activity previously was evaluated for the synergistic effect when used as a pretreatment agent in nab-PTX therapy against various tumor models. In the high vascular permeability C26 murine colon cancer subcutaneous inoculation model, SNO-HSA Dimer enhanced tumor selectivity of nab-PTX, and attenuated myelosuppression. SNO-HSA Dimer also augmented the tumor growth inhibition of nab-PTX in low vascular permeability B16 murine melanoma subcutaneous inoculation model. Furthermore, nab-PTX therapy combined with SNO-HSA Dimer showed higher antitumor activity and improved survival rate of SUIT2 human pancreatic cancer orthotopic model. In conclusion, SNO-HSA Dimer could enhance the therapeutic effect of nab-PTX even in low vascular permeability or intractable pancreatic cancers. The possible underlying mechanisms of action of SNO-HSA Dimer were discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Reducing HAuCl4 by the C60 dianion: C60-directed self-assembly of gold nanoparticles into novel fullerene bound gold nanoassemblies

    International Nuclear Information System (INIS)

    Liu Wei; Gao Xiang

    2008-01-01

    The C 60 dianion is used to reduce tetrachloroauric acid (HAuCl 4 ) for the first time; three-dimensional C 60 bound gold (Au-C 60 ) nanoclusters are obtained from C 60 -directed self-assembly of gold nanoparticles due to the strong affinities of Au-C 60 and C 60 -C 60 . The process was monitored in situ by UV-vis-NIR spectroscopy. The resulting Au-C 60 nanoclusters were characterized using transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy-dispersive spectroscopy (EDS), x-ray powder diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and FT-IR and Raman spectroscopies. TEM demonstrates the formation of 3D nanonetwork aggregates, which are composed of discrete gold nanocores covered with a C 60 monolayer. The SAED and XRD patterns indicate that the gold nanocores inside the capped C 60 molecules belong to the face-centred cubic crystal structure, while the C 60 molecules are amorphous. The EDS and XPS measurements validate that the Au-C 60 nanoclusters contain only Au and C elements and Au 3+ is reduced to Au 0 . FT-IR spectroscopy shows the chemiadsorption of C 60 to the gold nanocores, while Raman spectroscopy demonstrates the electron transfer from the gold nanocores to the chemiadsorbed C 60 molecules. Au-C 60 nanoclusters embedded in tetraoctyl-n-ammonium bromide (TOAB) on glassy carbon electrodes (GCEs) have been fabricated and have shown stable and well-defined electrochemical responses in aqueous solution

  10. A Feasibility Study of Bevacizumab Plus Dose-Dense Doxorubicin–Cyclophosphamide (AC) Followed by Nanoparticle Albumin–Bound Paclitaxel in Early-Stage Breast Cancer

    Science.gov (United States)

    McArthur, Heather L.; Rugo, Hope; Nulsen, Benjamin; Hawks, Laura; Grothusen, Jill; Melisko, Michelle; Moasser, Mark; Paulson, Matthew; Traina, Tiffany; Patil, Sujata; Zhou, Qin; Steingart, Richard; Dang, Chau; Morrow, Monica; Cordeiro, Peter; Fornier, Monica; Park, John; Seidman, Andrew; Lake, Diana; Gilewski, Theresa; Theodoulou, Maria; Modi, Shanu; D’Andrea, Gabriella; Sklarin, Nancy; Robson, Mark; Moynahan, Mary Ellen; Sugarman, Steven; Sealey, Jane E.; Laragh, John H.; Merali, Carmen; Norton, Larry; Hudis, Clifford A.; Dickler, Maura N.

    2016-01-01

    Purpose Bevacizumab confers benefits in metastatic breast cancer but may be more effective as adjuvant therapy. We evaluated the cardiac safety of bevacizumab plus dose-dense doxorubicin–cyclophosphamide (ddAC)→nanoparticle albumin−bound (nab)-paclitaxel in human epidermal growth factor receptor 2 normal early-stage breast cancer. Experimental Design Eighty patients with normal left ventricular ejection fraction (LVEF) were enrolled. Bevacizumab was administered for 1 year, concurrently with ddAC→nab-paclitaxel then as a single agent. LVEF was evaluated at months 0, 2, 6, 9, and 18. This regimen was considered safe if fewer than three cardiac events or fewer than two deaths from left ventricular dysfunction occurred. Correlative studies of cardiac troponin (cTn) and plasma renin activity (PRA) were conducted. Results The median age was 48 years (range, 27−75 years), and baseline LVEF was 68% (53%−82%). After 39 months’ median follow-up (5−45 months): median LVEF was 68% (53%−80%) at 2 months (n=78), 64% (51%−77%) at 6 months (n=66), 63% (48%−77%) at 9 months (n=61), and 66% (42%−76%) at 18 months (n=54). One patient developed symptomatic LV dysfunction at month 15. Common toxicities necessitating treatment discontinuation were hypertension (HTN, 4%), wound-healing complications (4%), and asymptomatic LVEF declines (4%). Neither cTn nor PRA predicted CHF or HTN, respectively. Conclusions Bevacizumab with ddAC→nab-paclitaxel had a low rate of cardiac events; cTn and PRA levels are not predictive of CHF or HTN, respectively. The efficacy of bevacizumab as adjuvant treatment will be established in several ongoing phase III trials. PMID:21350003

  11. Design and development of a highly stable hydrogen peroxide biosensor on screen printed carbon electrode based on horseradish peroxidase bound with gold nanoparticles in the matrix of chitosan.

    Science.gov (United States)

    Tangkuaram, Tanin; Ponchio, Chatchai; Kangkasomboon, Thippayawadee; Katikawong, Panadda; Veerasai, Waret

    2007-04-15

    The design and development of a screen printed carbon electrode (SPCE) on a polyvinyl chloride substrate as a disposable sensor is described. Six configurations were designed on silk screen frames. The SPCEs were printed with four inks: silver ink as the conducting track, carbon ink as the working and counter electrodes, silver/silver chloride ink as the reference electrode and insulating ink as the insulator layer. Selection of the best configuration was done by comparing slopes from the calibration plots generated by the cyclic voltammograms at 10, 20 and 30 mM K(3)Fe(CN)(6) for each configuration. The electrodes with similar configurations gave similar slopes. The 5th configuration was the best electrode that gave the highest slope. Modifying the best SPCE configuration for use as a biosensor, horseradish peroxidase (HRP) was selected as a biomaterial bound with gold nanoparticles (AuNP) in the matrix of chitosan (HRP/AuNP/CHIT). Biosensors of HRP/SPCE, HRP/CHIT/SPCE and HRP/AuNP/CHIT/SPCE were used in the amperometric detection of H(2)O(2) in a solution of 0.1M citrate buffer, pH 6.5, by applying a potential of -0.4V at the working electrode. All the biosensors showed an immediate response to H(2)O(2). The effect of HRP/AuNP incorporated with CHIT (HRP/AuNP/CHIT/SPCE) yielded the highest performance. The amperometric response of HRP/AuNP/CHIT/SPCE retained over 95% of the initial current of the 1st day up to 30 days of storage at 4 degrees C. The biosensor showed a linear range of 0.01-11.3mM H(2)O(2), with a detection limit of 0.65 microM H(2)O(2) (S/N=3). The low detection limit, long storage life and wide linear range of this biosensor make it advantageous in many applications, including bioreactors and biosensors.

  12. Phase I/II dose-finding study of nanoparticle albumin-bound paclitaxel (nab®-Paclitaxel) plus Cisplatin as Treatment for Metastatic Nasopharyngeal Carcinoma.

    Science.gov (United States)

    Huang, Yan; Liang, Wenhua; Yang, Yunpeng; Zhao, Liping; Zhao, Hongyun; Wu, Xuan; Zhao, Yuanyuan; Zhang, Yang; Zhang, Li

    2016-07-13

    This phase I/II study aimed to determine the maximum tolerated dose (MTD) of nanoparticle albumin-bound paclitaxel (nab (®)-paclitaxel) plus cisplatin as treatment for metastatic nasopharyngeal carcinoma (NPC). Patients were enrolled into 1 of 3 dose cohorts, each with 21-day treatment cycles: 1) intravenous (IV) nab-paclitaxel 260 mg/m(2) on day 1; 2) IV nab-paclitaxel 140 mg/m(2) on days 1 and 8; 3) IV nab-paclitaxel 100 mg/m(2) on days 1, 8, and 15. All patients received IV cisplatin 75 mg/m(2) on day 1. Treatment continued for 4-6 cycles, or until progression or unacceptable toxicity. If more than one-third of the patients in a cohort experienced a dose-limiting toxicity (DLT), the dose used in the previous cohort would be designated the MTD. Secreted protein acidic and rich in cysteine (SPARC) expression was detected by immunohistochemistry staining. Sixty-nine patients were enrolled, of whom 64 and 67 were eligible for efficacy and safety analysis, respectively. Two DLTs occurred in cohort 1 (grade 4 febrile neutropenia, grade 3 myalgia), none occurred in cohort 2, and 2 occurred in cohort 3 (both grade 3 fatigue). The MTD was not reached. Partial responses were achieved by 42 patients, 15 had stable disease, and 7 had progressive disease, giving an overall response rate of 66 %. Median progression-free survival was 9 months (95 % CI, 6-12 months). Grade ≥ 3 adverse events were mainly hematologic. There was no significant difference between the 3 cohorts with respect to efficacy or safety. Biomarker analyses indicated that stromal, rather than tumoral, SPARC may predict the response to nab-paclitaxel in NPC. Our findings suggest that nab-paclitaxel plus cisplatin is a highly active regimen with moderate toxicity for the treatment of metastatic NPC, which warrants further investigation in a phase III study. ClinicalTrials.gov ID: NCT01735409 . The trial was registered on November 20th, 2012.

  13. Phase I/II dose-finding study of nanoparticle albumin-bound paclitaxel (nab®-Paclitaxel) plus Cisplatin as Treatment for Metastatic Nasopharyngeal Carcinoma

    International Nuclear Information System (INIS)

    Huang, Yan; Liang, Wenhua; Yang, Yunpeng; Zhao, Liping; Zhao, Hongyun; Wu, Xuan; Zhao, Yuanyuan; Zhang, Yang; Zhang, Li

    2016-01-01

    This phase I/II study aimed to determine the maximum tolerated dose (MTD) of nanoparticle albumin-bound paclitaxel (nab ® -paclitaxel) plus cisplatin as treatment for metastatic nasopharyngeal carcinoma (NPC). Patients were enrolled into 1 of 3 dose cohorts, each with 21-day treatment cycles: 1) intravenous (IV) nab-paclitaxel 260 mg/m 2 on day 1; 2) IV nab-paclitaxel 140 mg/m 2 on days 1 and 8; 3) IV nab-paclitaxel 100 mg/m 2 on days 1, 8, and 15. All patients received IV cisplatin 75 mg/m 2 on day 1. Treatment continued for 4–6 cycles, or until progression or unacceptable toxicity. If more than one-third of the patients in a cohort experienced a dose-limiting toxicity (DLT), the dose used in the previous cohort would be designated the MTD. Secreted protein acidic and rich in cysteine (SPARC) expression was detected by immunohistochemistry staining. Sixty-nine patients were enrolled, of whom 64 and 67 were eligible for efficacy and safety analysis, respectively. Two DLTs occurred in cohort 1 (grade 4 febrile neutropenia, grade 3 myalgia), none occurred in cohort 2, and 2 occurred in cohort 3 (both grade 3 fatigue). The MTD was not reached. Partial responses were achieved by 42 patients, 15 had stable disease, and 7 had progressive disease, giving an overall response rate of 66 %. Median progression-free survival was 9 months (95 % CI, 6–12 months). Grade ≥ 3 adverse events were mainly hematologic. There was no significant difference between the 3 cohorts with respect to efficacy or safety. Biomarker analyses indicated that stromal, rather than tumoral, SPARC may predict the response to nab-paclitaxel in NPC. Our findings suggest that nab-paclitaxel plus cisplatin is a highly active regimen with moderate toxicity for the treatment of metastatic NPC, which warrants further investigation in a phase III study. ClinicalTrials.gov ID: NCT01735409. The trial was registered on November 20th, 2012. The online version of this article (doi:10.1186/s12885

  14. Cost-Benefit Analysis of Nanoparticle Albumin-Bound Paclitaxel versus Solvent-Based Paclitaxel for the Treatment of Metastatic Breast Cancer in the United States

    Science.gov (United States)

    Vichansavakul, Kittaya

    Breast cancer is the second leading cause of death among women in the US. Although early detection and treatment help to increase survival rates, some unfortunate patients develop metastatic breast cancer that has no cure. Palliative treatment is the main objective in this group of patients in order to prolong life and reduce toxicities from interventions. In the advancement of treatment for metastatic breast cancer, solvent-based paclitaxel has been widely used. However, solvent-based paclitaxel often causes adverse reactions. Therefore, researchers have developed a new chemotherapy based on nanotechnology. One of these drugs is the Nanoparticle albumin-bound Paclitaxel. This nanodrug aims to increase therapeutic index by reducing adverse reactions from solvents and to improve efficacy of conventional cytotoxic chemotherapy. Breast cancer is a disease with high epidemiological and economic burden. The treatment of metastatic breast cancer has not only high direct costs but also high indirect costs. Breast cancer affects mass populations, especially women younger than 50 years of age. It relates to high indirect costs due to lost productivity and premature death because the majority of these patients are in the workforce. Because of the high cost of breast cancer therapies and short survival rates, the question is raised whether the costs and benefits are worth paying or not. Due to the rising costs in healthcare and new financing policies that have been developed to address this issue, economic evaluation is an important aspect of the development and use of any new interventions. To guide policy makers on how to allocate limited healthcare resources in the most efficient and effective manner, many economic evaluation methods can be used to measure the costs, benefits, and impacts of healthcare innovations. Currently, economic evaluation and health outcomes studies have focused greatly on cost-effectiveness and cost-utility analysis. However, the previous studies

  15. nanoparticles

    Science.gov (United States)

    Andreu-Cabedo, Patricia; Mondragon, Rosa; Hernandez, Leonor; Martinez-Cuenca, Raul; Cabedo, Luis; Julia, J. Enrique

    2014-10-01

    Thermal energy storage (TES) is extremely important in concentrated solar power (CSP) plants since it represents the main difference and advantage of CSP plants with respect to other renewable energy sources such as wind, photovoltaic, etc. CSP represents a low-carbon emission renewable source of energy, and TES allows CSP plants to have energy availability and dispatchability using available industrial technologies. Molten salts are used in CSP plants as a TES material because of their high operational temperature and stability of up to 500°C. Their main drawbacks are their relative poor thermal properties and energy storage density. A simple cost-effective way to improve thermal properties of fluids is to dope them with nanoparticles, thus obtaining the so-called salt-based nanofluids. In this work, solar salt used in CSP plants (60% NaNO3 + 40% KNO3) was doped with silica nanoparticles at different solid mass concentrations (from 0.5% to 2%). Specific heat was measured by means of differential scanning calorimetry (DSC). A maximum increase of 25.03% was found at an optimal concentration of 1 wt.% of nanoparticles. The size distribution of nanoparticle clusters present in the salt at each concentration was evaluated by means of scanning electron microscopy (SEM) and image processing, as well as by means of dynamic light scattering (DLS). The cluster size and the specific surface available depended on the solid content, and a relationship between the specific heat increment and the available particle surface area was obtained. It was proved that the mechanism involved in the specific heat increment is based on a surface phenomenon. Stability of samples was tested for several thermal cycles and thermogravimetric analysis at high temperature was carried out, the samples being stable.

  16. Enhancing intracellular taxane delivery: current role and perspectives of nanoparticle albumin-bound paclitaxel in the treatment of advanced breast cancer.

    Science.gov (United States)

    Guarneri, Valentina; Dieci, Maria Vittoria; Conte, Pierfranco

    2012-02-01

    Docetaxel and paclitaxel are among the most active agents for the treatment of breast cancer. These first-generation taxanes are extremely hydrophobic; therefore, solvents are needed for its parenteral administration. Albumin nanoparticle technology allows for the transportation of such hydrophobic drugs without the need of potentially toxic solvents. Nab-paclitaxel can be administered without premedication, in a shorter infusion time and without the need for a special infusion set. Moreover, this technology allows the selective delivery of larger amounts of anticancer drug to tumors, by exploiting endogenous albumin pathways. An overview of the albumin nanoparticle technology, from a clinical perspective, is reported in this paper. The preclinical and clinical development of nab-paclitaxel is reviewed, in the context of available therapies for advanced breast cancer, with a focus on safety data. Preclinical and clinical data on the prognostic and predictive role of SPARC (secreted protein, acidic and rich in cysteine) are also reported. Nab-paclitaxel is approved at present for the treatment of metastatic breast cancer, after the failure of first-line standard therapy, when anthracyclines are not indicated. Efficacy and safety data, along with a more convenient administration, confirm the potential for nab-paclitaxel to become a reference taxane in breast cancer treatment.

  17. Phase II Study of Neoadjuvant Anthracycline-Based Regimens Combined With Nanoparticle Albumin-Bound Paclitaxel and Trastuzumab for Human Epidermal Growth Factor Receptor 2-Positive Operable Breast Cancer.

    Science.gov (United States)

    Tanaka, Satoru; Iwamoto, Mitsuhiko; Kimura, Kosei; Matsunami, Nobuki; Morishima, Hirotaka; Yoshidome, Katsuhide; Nomura, Takashi; Morimoto, Takashi; Yamamoto, Daigo; Tsubota, Yu; Kobayashi, Toshihiro; Uchiyama, Kazuhisa

    2015-06-01

    We treated patients with operable human epidermal growth factor receptor 2-positive breast cancer with neoadjuvant anthracycline regimens followed by nanoparticle albumin-bound paclitaxel plus trastuzumab. Of the 44 patients, 49% achieved a pathologic complete response (pCR). The pCR rate was 36% and 71% in the patients with estrogen receptor-positive and -negative cancer, respectively. Neoadjuvant therapy using this combination appears to be effective and safe. Introduction: Neoadjuvant chemotherapy plus trastuzumab. Neoadjuvant chemotherapy plus trastuzumab results in a 30% to 50% pathologic complete response (pCR) rate in human epidermal growth factor receptor 2 (HER2)-positive breast cancer and has been associated with improved therapeutic outcomes. Thus, the pCR rate can be useful in evaluating novel agents in this patient population. Nanoparticle albumin-bound (nab)-paclitaxel (PTX) can reduce the toxicity of PTX while maintaining its efficacy. The present study evaluated the activity and safety of nab-PTX as a neoadjuvant treatment of HER2(+) breast cancer. We treated patients with stage I to IIIA breast cancer using neoadjuvant epirubicin/cyclophosphamide (EC) or 5-fluorouracil/epirubicin/cyclophosphamide every 3 weeks (q3w) for 4 cycles, followed by nab-PTX (260 mg/m(2)) plus trastuzumab q3w for 4 cycles. The primary endpoint was the pCR rate. The secondary endpoints included the clinical response rate, disease-free survival, pathologic response rate (defined as pCR or minimal residual invasive disease only in the breast), breast-conserving surgery rate, and safety. Forty-six patients were enrolled. One patient met the exclusion criteria because of the coexistence of another malignant disease; therefore, we evaluated 45 patients in the entire study. One patient experienced rapid disease progression during EC therapy, leaving 44 patients evaluable for nab-PTX treatment. Of the 45 patients, 49% achieved a pCR. The pCR rate was 36% and 71% in those with

  18. Weekly nanoparticle albumin bound-paclitaxel in combination with cisplatin versus weekly solvent-based paclitaxel plus cisplatin as first-line therapy in Chinese patients with advanced esophageal squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Wang HY

    2016-09-01

    Full Text Available Hai-ying Wang, Zhi-hua Yao, Hong Tang, Yan Zhao, Xiao-san Zhang, Shu-na Yao, Shu-jun Yang, Yan-yan Liu Department of Internal Medicine, Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou, Henan, People’s Republic of China Objective: More effective regimens for advanced esophageal squamous cell carcinoma (ESCC are urgently needed. Therefore, a retrospective study concerning the efficacy and safety of nanoparticle albumin-bound paclitaxel plus cisplatin (nab-TP versus solvent-based paclitaxel plus cisplatin (sb-TP as a first-line therapy was conducted in Chinese patients with advanced ESCC.Methods: From June 2009 to June 2015, 32 patients were treated with nab-paclitaxel (125 mg/m2 on the first and eighth days (30 minutes infusion and cisplatin (75 mg/m2 on the second day every 21 days (nab-TP arm. Also, 43 patients were treated with solvent-based paclitaxel (80 mg/m2 intravenously on the first and eighth days and the same dose of cisplatin (sb-TP arm. The two groups were compared in terms of objective response rate (ORR, disease control rate, progression-free survival (PFS, overall survival (OS, and safety profile. OS and PFS were estimated using Kaplan–Meier methods to determine associations between chemotherapy regimens and survival outcomes.Results: Nab-TP demonstrated a higher ORR (50% vs 30%; P=0.082 and disease control rate (81% vs 65%; P=0.124 than sb-TP. Median OS was similar for nab-TP and sb-TP (12.5 vs 10.7 months; P=0.269. However, nab-TP resulted in a longer median PFS (6.1 months [95% confidence interval: 5.3–6.9] than sb-TP (5.0 months [95% confidence interval: 4.4–5.6] (P=0.029. The most common adverse events included anemia, leukopenia, neutropenia, febrile neutropenia, and thrombocytopenia in both the groups and no statistically significant differences were observed between the groups. With statistically significant differences, significantly less grade ≥3 peripheral neuropathy

  19. Promoting neuroregeneration by applying dynamic magnetic fields to a novel nanomedicine: Superparamagnetic iron oxide (SPIO)-gold nanoparticles bounded with nerve growth factor (NGF).

    Science.gov (United States)

    Yuan, Muzhaozi; Wang, Ya; Qin, Yi-Xian

    2018-04-05

    Neuroregeneration imposes a significant challenge in neuroscience for treating neurodegenerative diseases. The objective of this study is to evaluate the hypothesis that the nerve growth factor (NGF) functionalized superparamagnetic iron oxide (SPIO)-gold (Au) nanomedicine can stimulate the neuron growth and differentiation under external magnetic fields (MFs), and dynamic MFs outperform their static counterparts. The SPIO-Au core-shell nanoparticles (NPs) (Diameter: 20.8 nm) possessed advantages such as uniform quasi-spherical shapes, narrow size distribution, excellent stabilities, and low toxicity (viability >96% for 5 days). NGF functionalization has enhanced the cellular uptake. The promotion of neuronal growth and orientation using NGF functionalized SPIO-Au NPs, driven by both the static and dynamic MFs, were revealed experimentally on PC-12 cells and theoretically on a cytoskeletal force model. More importantly, dynamic MFs via rotation performed better than the static ones, i.e., the cellular differentiation ratio increased 58%; the neurite length elongation increased 63%. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. A randomized phase II study of carboplatin with weekly or every-3-week nanoparticle albumin-bound paclitaxel (abraxane) in patients with extensive-stage small cell lung cancer.

    Science.gov (United States)

    Grilley-Olson, Juneko E; Keedy, Vicki L; Sandler, Alan; Moore, Dominic T; Socinski, Mark A; Stinchcombe, Thomas E

    2015-02-01

    Platinum plus etoposide is the standard therapy for extensive-stage small cell lung cancer (ES-SCLC) and is associated with significant myelosuppression. We hypothesized that the combination of carboplatin and nanoparticle albumin-bound paclitaxel (nab-paclitaxel) would be better tolerated. We investigated carboplatin with nab-paclitaxel on every-3-week and weekly schedules. This noncomparative randomized phase II trial used a two-stage design. The primary objective was objective response rate, and secondary objectives were progression-free survival, overall survival, and toxicity. Patients with ES-SCLC and an Eastern Cooperative Oncology Group performance status ≤2 and no prior chemotherapy were randomized in a 1:1 ratio to arm A (carboplatin area under the curve [AUC] of 6 on day 1 and nab-paclitaxel of 300 mg/m(2) on day 1 every 3 weeks) or arm B (carboplatin AUC of 6 on day 1 and nab-paclitaxel 100 mg/m(2) on days 1, 8, and 15 every 21 days). Response was assessed after every two cycles. Patients required frequent dose reductions, treatment delays, and omission of the weekly therapy. The trial was closed because of slow accrual. Carboplatin and nab-paclitaxel demonstrated activity in ES-SCLC but required frequent dose adjustments. ©AlphaMed Press; the data published online to support this summary is the property of the authors.

  1. Perceptron Mistake Bounds

    OpenAIRE

    Mohri, Mehryar; Rostamizadeh, Afshin

    2013-01-01

    We present a brief survey of existing mistake bounds and introduce novel bounds for the Perceptron or the kernel Perceptron algorithm. Our novel bounds generalize beyond standard margin-loss type bounds, allow for any convex and Lipschitz loss function, and admit a very simple proof.

  2. Circuit lower bounds in bounded arithmetics

    Czech Academy of Sciences Publication Activity Database

    Pich, Ján

    2015-01-01

    Roč. 166, č. 1 (2015), s. 29-45 ISSN 0168-0072 R&D Projects: GA AV ČR IAA100190902 Keywords : bounded arithmetic * circuit lower bounds Subject RIV: BA - General Mathematics Impact factor: 0.582, year: 2015 http://www.sciencedirect.com/science/article/pii/S0168007214000888

  3. Scattering by bound nucleons

    International Nuclear Information System (INIS)

    Tezuka, Hirokazu.

    1984-10-01

    Scattering of a particle by bound nucleons is discussed. Effects of nucleons that are bound in a nucleus are taken as a structure function. The way how to calculate the structure function is given. (author)

  4. Computation of Casimir interactions between arbitrary three-dimensional objects with arbitrary material properties

    International Nuclear Information System (INIS)

    Reid, M. T. Homer; White, Jacob; Johnson, Steven G.

    2011-01-01

    We extend a recently introduced method for computing Casimir forces between arbitrarily shaped metallic objects [M. T. H. Reid et al., Phys. Rev. Lett. 103 040401 (2009)] to allow treatment of objects with arbitrary material properties, including imperfect conductors, dielectrics, and magnetic materials. Our original method considered electric currents on the surfaces of the interacting objects; the extended method considers both electric and magnetic surface current distributions, and obtains the Casimir energy of a configuration of objects in terms of the interactions of these effective surface currents. Using this new technique, we present the first predictions of Casimir interactions in several experimentally relevant geometries that would be difficult to treat with any existing method. In particular, we investigate Casimir interactions between dielectric nanodisks embedded in a dielectric fluid; we identify the threshold surface-surface separation at which finite-size effects become relevant, and we map the rotational energy landscape of bound nanoparticle diclusters.

  5. Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) as second-line chemotherapy in HER2-negative, taxane-pretreated metastatic breast cancer patients: prospective evaluation of activity, safety, and quality of life.

    Science.gov (United States)

    Palumbo, Raffaella; Sottotetti, Federico; Trifirò, Giuseppe; Piazza, Elena; Ferzi, Antonella; Gambaro, Anna; Spinapolice, Elena Giulia; Pozzi, Emma; Tagliaferri, Barbara; Teragni, Cristina; Bernardo, Antonio

    2015-01-01

    A prospective, multicenter trial was undertaken to assess the activity, safety, and quality of life of nanoparticle albumin-bound paclitaxel (nab-paclitaxel) as second-line chemotherapy in HER2-negative, taxane-pretreated metastatic breast cancer (MBC). Fifty-two women with HER2-negative MBC who were candidates for second-line chemotherapy for the metastatic disease were enrolled and treated at three centers in Northern Italy. All patients had previously received taxane-based chemotherapy in the adjuvant or first-line metastatic setting. Single-agent nab-paclitaxel was given at the dose of 260 mg/m(2) as a 30-minute intravenous infusion on day 1 each treatment cycle, which lasted 3 weeks, in the outpatient setting. No steroid or antihistamine premedication was provided. Treatment was stopped for documented disease progression, unacceptable toxicity, or patient refusal. All of the enrolled patients were evaluable for the study endpoints. The objective response rate was 48% (95% CI, 31.5%-61.3%) and included complete responses from 13.5%. Disease stabilization was obtained in 19 patients and lasted >6 months in 15 of them; the overall clinical benefit rate was 77%. The median time to response was 70 days (range 52-86 days). The median progression-free survival time was 8.9 months (95% CI, 8.0-11.6 months, range 5-21+ months). The median overall survival point has not yet been reached. Toxicities were expected and manageable with good patient compliance and preserved quality of life in patients given long-term treatment. Our results showed that single-agent nab-paclitaxel 260 mg/m(2) every 3 weeks is an effective and well tolerated regimen as second-line chemotherapy in HER2-negative, taxane-pretreated MBC patients, and that it produced interesting values of objective response rate and progression-free survival without the concern of significant toxicity. Specifically, the present study shows that such a regimen is a valid therapeutic option for that 'difficult to

  6. Physical Uncertainty Bounds (PUB)

    Energy Technology Data Exchange (ETDEWEB)

    Vaughan, Diane Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Dean L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-03-19

    This paper introduces and motivates the need for a new methodology for determining upper bounds on the uncertainties in simulations of engineered systems due to limited fidelity in the composite continuum-level physics models needed to simulate the systems. We show that traditional uncertainty quantification methods provide, at best, a lower bound on this uncertainty. We propose to obtain bounds on the simulation uncertainties by first determining bounds on the physical quantities or processes relevant to system performance. By bounding these physics processes, as opposed to carrying out statistical analyses of the parameter sets of specific physics models or simply switching out the available physics models, one can obtain upper bounds on the uncertainties in simulated quantities of interest.

  7. Photon virtual bound state

    International Nuclear Information System (INIS)

    Inoue, J.; Ohtaka, K.

    2004-01-01

    We study virtual bound states in photonics, which are a vectorial extension of electron virtual bound states. The condition for these states is derived. It is found that the Mie resonant state which satisfies the condition that the size parameter is less than the angular momentum should be interpreted as a photon virtual bound state. In order to confirm the validity of the concept, we compare the photonic density of states, the width of which represents the lifetime of the photon virtual bound states, with numerical results

  8. The DMM Bound

    DEFF Research Database (Denmark)

    Emiris, Ioannis Z.; Mourrain, Bernard; Tsigaridas, Elias

    2010-01-01

    ) resultant by means of mixed volume, as well as recent advances on aggregate root bounds for univariate polynomials, and are applicable to arbitrary positive dimensional systems. We improve upon Canny's gap theorem [7] by a factor of O(dn-1), where d bounds the degree of the polynomials, and n is the number...... bound on the number of steps that subdivision-based algorithms perform in order to isolate all real roots of a polynomial system. This leads to the first complexity bound of Milne's algorithm [22] in 2D....

  9. Bounded Gaussian process regression

    DEFF Research Database (Denmark)

    Jensen, Bjørn Sand; Nielsen, Jens Brehm; Larsen, Jan

    2013-01-01

    We extend the Gaussian process (GP) framework for bounded regression by introducing two bounded likelihood functions that model the noise on the dependent variable explicitly. This is fundamentally different from the implicit noise assumption in the previously suggested warped GP framework. We...... with the proposed explicit noise-model extension....

  10. Bounded Intention Planning Revisited

    OpenAIRE

    Sievers Silvan; Wehrle Martin; Helmert Malte

    2014-01-01

    Bounded intention planning provides a pruning technique for optimal planning that has been proposed several years ago. In addition partial order reduction techniques based on stubborn sets have recently been investigated for this purpose. In this paper we revisit bounded intention planning in the view of stubborn sets.

  11. Bounding species distribution models

    Directory of Open Access Journals (Sweden)

    Thomas J. STOHLGREN, Catherine S. JARNEVICH, Wayne E. ESAIAS,Jeffrey T. MORISETTE

    2011-10-01

    Full Text Available Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for “clamping” model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART and maximum entropy (Maxent models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5: 642–647, 2011].

  12. Bounding Species Distribution Models

    Science.gov (United States)

    Stohlgren, Thomas J.; Jarnevich, Cahterine S.; Morisette, Jeffrey T.; Esaias, Wayne E.

    2011-01-01

    Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for "clamping" model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART) and maximum entropy (Maxent) models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5): 642-647, 2011].

  13. Organically bound tritium

    International Nuclear Information System (INIS)

    Diabate, S.; Strack, S.

    1993-01-01

    Tritium released into the environment may be incorporated into organic matter. Organically bound tritium in that case will show retention times in organisms that are considerably longer than those of tritiated water which has significant consequences on dose estimates. This article reviews the most important processes of organically bound tritium production and transport through food networks. Metabolic reactions in plant and animal organisms with tritiated water as a reaction partner are of great importance in this respect. The most important production process, in quantitative terms, is photosynthesis in green plants. The translocation of organically bound tritium from the leaves to edible parts of crop plants should be considered in models of organically bound tritium behavior. Organically bound tritium enters the human body on several pathways, either from the primary producers (vegetable food) or at a higher tropic level (animal food). Animal experiments have shown that the dose due to ingestion of organically bound tritium can be up to twice as high as a comparable intake of tritiated water in gaseous or liquid form. In the environment, organically bound tritium in plants and animals is often found to have higher specific tritium concentrations than tissue water. This is not due to some tritium enrichment effects but to the fact that no equilibrium conditions are reached under natural conditions. 66 refs

  14. Deeply bound pionic atom

    International Nuclear Information System (INIS)

    Toki, Hiroshi; Yamazaki, Toshimitsu

    1989-01-01

    The standard method of pionic atom formation does not produce deeply bound pionic atoms. A study is made on the properties of deeply bound pionic atom states by using the standard pion-nucleus optical potential. Another study is made to estimate the cross sections of the formation of ls pionic atom states by various methods. The pion-nucleus optical potential is determined by weakly bound pionic atom states and pion nucleus scattering. Although this potential may not be valid for deeply bound pionic atoms, it should provide some hint on binding energies and level widths of deeply bound states. The width of the ls state comes out to be 0.3 MeV and is well separated from the rest. The charge dependence of the ls state is investigated. The binding energies and the widths increase linearly with Z azbove a Z of 30. The report then discusses various methods to populate deeply bound pionic atoms. In particular, 'pion exchange' reactions are proposed. (n, pπ) reaction is discussed first. The cross section is calculated by assuming the in- and out-going nucleons on-shell and the produced pion in (n1) pionic atom states. Then, (n, dπ - ) cross sections are estimated. (p, 2 Heπ - ) reaction would have cross sections similar to the cross section of (n, dπ - ) reaction. In conclusion, it seems best to do (n, p) experiment on heavy nuclei for deeply bound pionic atom. (Nogami, K.)

  15. Bounded Rationality and Budgeting

    OpenAIRE

    Ibrahim, Mukdad

    2016-01-01

    This article discusses the theory of bounded rationality which had been introduced by Herbert Simon in the 1950s. Simon introduced the notion of bounded rationality stating that while decision-makers strive for rationality, they are limited by the effect of the environment, their information process capacity and by the constraints on their information storage and retrieval capabilities. Moreover, this article tries to specifically blend this notion into budgeting, using the foundations of inc...

  16. Virial Expansion Bounds

    Science.gov (United States)

    Tate, Stephen James

    2013-10-01

    In the 1960s, the technique of using cluster expansion bounds in order to achieve bounds on the virial expansion was developed by Lebowitz and Penrose (J. Math. Phys. 5:841, 1964) and Ruelle (Statistical Mechanics: Rigorous Results. Benjamin, Elmsford, 1969). This technique is generalised to more recent cluster expansion bounds by Poghosyan and Ueltschi (J. Math. Phys. 50:053509, 2009), which are related to the work of Procacci (J. Stat. Phys. 129:171, 2007) and the tree-graph identity, detailed by Brydges (Phénomènes Critiques, Systèmes Aléatoires, Théories de Jauge. Les Houches 1984, pp. 129-183, 1986). The bounds achieved by Lebowitz and Penrose can also be sharpened by doing the actual optimisation and achieving expressions in terms of the Lambert W-function. The different bound from the cluster expansion shows some improvements for bounds on the convergence of the virial expansion in the case of positive potentials, which are allowed to have a hard core.

  17. Bound and rebound states

    International Nuclear Information System (INIS)

    Orzalesi, C.A.

    1979-01-01

    In relativistic quantum theory, bound states generate forces in the crossed channel; such forces can affect the binding and self-consistent solutions should be sought for the bound-state problem. The author investigates how self-consistency can be achieved by successive approximations, in a simple scalar model and with successive relativistic eikonal approximations (EAs). Within the generalized ladder approximation, some exact properties of the resulting ''first generation'' bound states are discussed. The binding energies in this approximation are rather small even for rather large values of the primary coupling constant. The coupling of the constituent particles to the first-generation reggeon is determined by a suitable EA and a new generalized ladder amplitude is constructed with rungs given either by the primary gluons or by the first-generation reggeons. The resulting new (second-generation) bound states are found in a reggeized EA. The size of the corrections to the binding energies due to the rebinding effects is surprisingly large. The procedure is then iterated, so as to find - again in an EA - the third-generation bound states. The procedure is found to be self-consistent already at this stage: the third-generation bound states coincide with those of second generation, and no further rebinding takes place in the higher iterations of the approximation method. Features - good and bad - of the model are discussed, as well as the possible relevance of rebinding mechanisms in hadron dynamics. (author)

  18. Bounded Tamper Resilience

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Faust, Sebastian; Mukherjee, Pratyay

    2013-01-01

    Related key attacks (RKAs) are powerful cryptanalytic attacks where an adversary can change the secret key and observe the effect of such changes at the output. The state of the art in RKA security protects against an a-priori unbounded number of certain algebraic induced key relations, e.......g., affine functions or polynomials of bounded degree. In this work, we show that it is possible to go beyond the algebraic barrier and achieve security against arbitrary key relations, by restricting the number of tampering queries the adversary is allowed to ask for. The latter restriction is necessary......-protocols (including the Okamoto scheme, for instance) are secure even if the adversary can arbitrarily tamper with the prover’s state a bounded number of times and obtain some bounded amount of leakage. Interestingly, for the Okamoto scheme we can allow also independent tampering with the public parameters. We show...

  19. Massive Galileon positivity bounds

    Science.gov (United States)

    de Rham, Claudia; Melville, Scott; Tolley, Andrew J.; Zhou, Shuang-Yong

    2017-09-01

    The EFT coefficients in any gapped, scalar, Lorentz invariant field theory must satisfy positivity requirements if there is to exist a local, analytic Wilsonian UV completion. We apply these bounds to the tree level scattering amplitudes for a massive Galileon. The addition of a mass term, which does not spoil the non-renormalization theorem of the Galileon and preserves the Galileon symmetry at loop level, is necessary to satisfy the lowest order positivity bound. We further show that a careful choice of successively higher derivative corrections are necessary to satisfy the higher order positivity bounds. There is then no obstruction to a local UV completion from considerations of tree level 2-to-2 scattering alone. To demonstrate this we give an explicit example of such a UV completion.

  20. Bounded variation and around

    CERN Document Server

    Appell, Jürgen; Merentes Díaz, Nelson José

    2013-01-01

    This monographis a self-contained exposition of the definition and properties of functionsof bounded variation and their various generalizations; the analytical properties of nonlinear composition operators in spaces of such functions; applications to Fourier analysis, nonlinear integral equations, and boundary value problems. The book is written for non-specialists. Every chapter closes with a list of exercises and open problems.

  1. Life-time of the bound layer in nanocomposites

    Science.gov (United States)

    Zhao, Dan; Jestin, Jacques; Kumar, Sanat K.

    2015-03-01

    It is now well accepted that an effectively irreversibly adsorbed monolayer of polymer forms when a polymer melt is intimately mixed with nanoparticles, in the limit where their enthalpic interactions are favorable. This bound layer has been postulated as being a central player in many of the highly favorable properties that result from polymer based nanocomposite materials. We investigated well-defined nanocomposites formed with different combinations of deuterated and hydrogenated polymers (P2VP and PMMA) and silica nanoparticles. SANS, in conjunction with contrast variation, then provides a direct means of probing the structure of the bound layer as a core-shell and its exchange kinetics with bulk (unbound) chains with annealing time and temperature. SAXS directly provides information on the particle-particle partial structure factor and particle dispersion. Thermodynamic equilibrium of the bound layer is reached around one day at 150 °C while its exchange life time is ~ one hour at 180 °C.

  2. Maps of Bounded Rationality

    OpenAIRE

    Kahneman, Daniel

    2002-01-01

    The work cited by the Nobel committee was done jointly with the late Amos Tversky (1937-1996) during a long and unusually close collaboration. Together, we explored the psychology of intuitive beliefs and choices and examined their bounded rationality. This essay presents a current perspective on the three major topics of our joint work: heuristics of judgment, risky choice, and framing effects. In all three domains we studied intuitions - thoughts and preferences that come to mind quickly an...

  3. Bounded Satisfiability for PCTL

    OpenAIRE

    Bertrand, Nathalie; Fearnley, John; Schewe, Sven

    2012-01-01

    While model checking PCTL for Markov chains is decidable in polynomial-time, the decidability of PCTL satisfiability, as well as its finite model property, are long standing open problems. While general satisfiability is an intriguing challenge from a purely theoretical point of view, we argue that general solutions would not be of interest to practitioners: such solutions could be too big to be implementable or even infinite. Inspired by bounded synthesis techniques, we turn to the more appl...

  4. Surface chemistry of "unprotected" nanoparticles

    DEFF Research Database (Denmark)

    Schrader, Imke; Warneke, Jonas; Neumann, Sarah

    2015-01-01

    The preparation of colloidal nanoparticles in alkaline ethylene glycol is a powerful approach for the preparation of model catalysts and ligand-functionalized nanoparticles. For these systems the term "unprotected" nanoparticles has been established because no strongly binding stabilizers...... study. "Unprotected" Pt and Ru nanoparticles were characterized by NMR spectroscopy, which does not evidence the presence of any C-H containing species bound to the particle surface. Instead, the colloids were found to be covered by CO, as demonstrated by IR spectroscopy. However, analysis...

  5. Adsorbent catalytic nanoparticles and methods of using the same

    Energy Technology Data Exchange (ETDEWEB)

    Slowing, Igor Ivan; Kandel, Kapil

    2017-01-31

    The present invention provides an adsorbent catalytic nanoparticle including a mesoporous silica nanoparticle having at least one adsorbent functional group bound thereto. The adsorbent catalytic nanoparticle also includes at least one catalytic material. In various embodiments, the present invention provides methods of using and making the adsorbent catalytic nanoparticles. In some examples, the adsorbent catalytic nanoparticles can be used to selectively remove fatty acids from feedstocks for biodiesel, and to hydrotreat the separated fatty acids.

  6. Universal bounds on current fluctuations.

    Science.gov (United States)

    Pietzonka, Patrick; Barato, Andre C; Seifert, Udo

    2016-05-01

    For current fluctuations in nonequilibrium steady states of Markovian processes, we derive four different universal bounds valid beyond the Gaussian regime. Different variants of these bounds apply to either the entropy change or any individual current, e.g., the rate of substrate consumption in a chemical reaction or the electron current in an electronic device. The bounds vary with respect to their degree of universality and tightness. A universal parabolic bound on the generating function of an arbitrary current depends solely on the average entropy production. A second, stronger bound requires knowledge both of the thermodynamic forces that drive the system and of the topology of the network of states. These two bounds are conjectures based on extensive numerics. An exponential bound that depends only on the average entropy production and the average number of transitions per time is rigorously proved. This bound has no obvious relation to the parabolic bound but it is typically tighter further away from equilibrium. An asymptotic bound that depends on the specific transition rates and becomes tight for large fluctuations is also derived. This bound allows for the prediction of the asymptotic growth of the generating function. Even though our results are restricted to networks with a finite number of states, we show that the parabolic bound is also valid for three paradigmatic examples of driven diffusive systems for which the generating function can be calculated using the additivity principle. Our bounds provide a general class of constraints for nonequilibrium systems.

  7. A bound on chaos

    Energy Technology Data Exchange (ETDEWEB)

    Maldacena, Juan [School of Natural Sciences, Institute for Advanced Study,1 Einstein Drive, Princeton, NJ (United States); Shenker, Stephen H. [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University,382 Via Pueblo Mall, Stanford, CA (United States); Stanford, Douglas [School of Natural Sciences, Institute for Advanced Study,1 Einstein Drive, Princeton, NJ (United States)

    2016-08-17

    We conjecture a sharp bound on the rate of growth of chaos in thermal quantum systems with a large number of degrees of freedom. Chaos can be diagnosed using an out-of-time-order correlation function closely related to the commutator of operators separated in time. We conjecture that the influence of chaos on this correlator can develop no faster than exponentially, with Lyapunov exponent λ{sub L}≤2πk{sub B}T/ℏ. We give a precise mathematical argument, based on plausible physical assumptions, establishing this conjecture.

  8. Relativistic bound states

    International Nuclear Information System (INIS)

    Ritchie, Burke

    2006-01-01

    The Hamiltonian for Dirac's second-order equation depends nonlinearly on the potential V and the energy E. For this reason the magnetic contribution to the Hamiltonian for s-waves, which has a short range, is attractive for a repulsive Coulomb potential (V>0) and repulsive for an attractive Coulomb potential (V 2 . Usually solutions are found in the regime E=mc 2 +ε , where except for high Z, ε 2 . Here it is shown that for V>0 the attractive magnetic term and the linear repulsive term combine to support a bound state near E=0.5mc 2 corresponding to a binding energy E b =-ε =0.5mc 2

  9. Bounding approaches to system identification

    CERN Document Server

    Norton, John; Piet-Lahanier, Hélène; Walter, Éric

    1996-01-01

    In response to the growing interest in bounding error approaches, the editors of this volume offer the first collection of papers to describe advances in techniques and applications of bounding of the parameters, or state variables, of uncertain dynamical systems. Contributors explore the application of the bounding approach as an alternative to the probabilistic analysis of such systems, relating its importance to robust control-system design.

  10. Market access through bound tariffs

    DEFF Research Database (Denmark)

    Sala, Davide; Yalcin, Erdal; Schröder, Philipp

    2010-01-01

    on the risk that exporters face in destination markets. The present paper formalizes the underlying interaction of risk, fixed export costs and firms' market entry decisions based on techniques known from the real options literature; doing so we highlight the important role of bound tariffs at the extensive...... margin of trade. We find that bound tariffs are more effective with higher risk destination markets, that a large binding overhang may still command substantial market access, and that reductions in bound tariffs generate effective market access even when bound rates are above current and longterm...

  11. Market Access through Bound Tariffs

    DEFF Research Database (Denmark)

    Sala, Davide; Schröder, Philipp J.H.; Yalcin, Erdal

    on the risk that exporters face in destination markets. The present paper formalizes the underlying interaction of risk, fixed export costs and firms' market entry decisions based on techniques known from the real options literature; doing so we highlight the important role of bound tariffs at the extensive...... margin of trade. We find that bound tariffs are more effective with higher risk destination markets, that a large binding overhang may still command substantial market access, and that reductions in bound tariffs generate effective market access even when bound rates are above current and long...

  12. Quivers of Bound Path Algebras and Bound Path Coalgebras

    Directory of Open Access Journals (Sweden)

    Dr. Intan Muchtadi

    2010-09-01

    Full Text Available bras and coalgebras can be represented as quiver (directed graph, and from quiver we can construct algebras and coalgebras called path algebras and path coalgebras. In this paper we show that the quiver of a bound path coalgebra (resp. algebra is the dual quiver of its bound path algebra (resp. coalgebra.

  13. Bounds for Asian basket options

    Science.gov (United States)

    Deelstra, Griselda; Diallo, Ibrahima; Vanmaele, Michèle

    2008-09-01

    In this paper we propose pricing bounds for European-style discrete arithmetic Asian basket options in a Black and Scholes framework. We start from methods used for basket options and Asian options. First, we use the general approach for deriving upper and lower bounds for stop-loss premia of sums of non-independent random variables as in Kaas et al. [Upper and lower bounds for sums of random variables, Insurance Math. Econom. 27 (2000) 151-168] or Dhaene et al. [The concept of comonotonicity in actuarial science and finance: theory, Insurance Math. Econom. 31(1) (2002) 3-33]. We generalize the methods in Deelstra et al. [Pricing of arithmetic basket options by conditioning, Insurance Math. Econom. 34 (2004) 55-57] and Vanmaele et al. [Bounds for the price of discrete sampled arithmetic Asian options, J. Comput. Appl. Math. 185(1) (2006) 51-90]. Afterwards we show how to derive an analytical closed-form expression for a lower bound in the non-comonotonic case. Finally, we derive upper bounds for Asian basket options by applying techniques as in Thompson [Fast narrow bounds on the value of Asian options, Working Paper, University of Cambridge, 1999] and Lord [Partially exact and bounded approximations for arithmetic Asian options, J. Comput. Finance 10 (2) (2006) 1-52]. Numerical results are included and on the basis of our numerical tests, we explain which method we recommend depending on moneyness and time-to-maturity.

  14. Product differentiation under bounded rationality

    NARCIS (Netherlands)

    Vermeulen, B.; Poutré, La J.A.; Kok, de A.G.; Pyka, A.; Handa, H.; Ishibuchi, H.; Ong, Y.-S.; Tan, K.-C.

    2015-01-01

    We study product differentiation equilibria and dynamics on the Salop circle under bounded rationality. Due to bounded rationality, firms tend to agglomerate in pairs. Upon adding a second tier of component suppliers, downstream assemblers may escape pairwise horizontal agglomeration. Moreover, we

  15. Metabolism of organically bound tritium

    International Nuclear Information System (INIS)

    Travis, C.C.

    1984-01-01

    The classic methodology for estimating dose to man from environmental tritium ignores the fact that organically bound tritium in foodstuffs may be directly assimilated in the bound compartment of tissues without previous oxidation. We propose a four-compartment model consisting of a free body water compartment, two organic compartments, and a small, rapidly metabolizing compartment. The utility of this model lies in the ability to input organically bound tritium in foodstuffs directly into the organic compartments of the model. We found that organically bound tritium in foodstuffs can increase cumulative total body dose by a factor of 1.7 to 4.5 times the free body water dose alone, depending on the bound-to-loose ratio of tritium in the diet. Model predictions are compared with empirical measurements of tritium in human urine and tissue samples, and appear to be in close agreement. 10 references, 4 figures, 3 tables

  16. (BDMCA) Nanoparticles

    African Journals Online (AJOL)

    Erah

    Available online at http://www.tjpr.org. Research Article ... Methods: Nanoparticle formulations were fabricated by a double emulsion solvent evaporation technique using .... Characterization of BDMCA nanoparticles. The nanoparticle ...

  17. Curvature bound from gravitational catalysis

    Science.gov (United States)

    Gies, Holger; Martini, Riccardo

    2018-04-01

    We determine bounds on the curvature of local patches of spacetime from the requirement of intact long-range chiral symmetry. The bounds arise from a scale-dependent analysis of gravitational catalysis and its influence on the effective potential for the chiral order parameter, as induced by fermionic fluctuations on a curved spacetime with local hyperbolic properties. The bound is expressed in terms of the local curvature scalar measured in units of a gauge-invariant coarse-graining scale. We argue that any effective field theory of quantum gravity obeying this curvature bound is safe from chiral symmetry breaking through gravitational catalysis and thus compatible with the simultaneous existence of chiral fermions in the low-energy spectrum. With increasing number of dimensions, the curvature bound in terms of the hyperbolic scale parameter becomes stronger. Applying the curvature bound to the asymptotic safety scenario for quantum gravity in four spacetime dimensions translates into bounds on the matter content of particle physics models.

  18. Combining Alphas via Bounded Regression

    Directory of Open Access Journals (Sweden)

    Zura Kakushadze

    2015-11-01

    Full Text Available We give an explicit algorithm and source code for combining alpha streams via bounded regression. In practical applications, typically, there is insufficient history to compute a sample covariance matrix (SCM for a large number of alphas. To compute alpha allocation weights, one then resorts to (weighted regression over SCM principal components. Regression often produces alpha weights with insufficient diversification and/or skewed distribution against, e.g., turnover. This can be rectified by imposing bounds on alpha weights within the regression procedure. Bounded regression can also be applied to stock and other asset portfolio construction. We discuss illustrative examples.

  19. Improved Range Searching Lower Bounds

    DEFF Research Database (Denmark)

    Larsen, Kasper Green; Nguyen, Huy L.

    2012-01-01

    by constructing a hard input set and query set, and then invoking Chazelle and Rosenberg's [CGTA'96] general theorem on the complexity of navigation in the pointer machine. For the group model, we show that input sets and query sets that are hard for range reporting in the pointer machine (i.e. by Chazelle...... and Rosenberg's theorem), are also hard for dynamic range searching in the group model. This theorem allows us to reuse decades of research on range reporting lower bounds to immediately obtain a range of new group model lower bounds. Amongst others, this includes an improved lower bound for the fundamental...

  20. Bound states in string nets

    Science.gov (United States)

    Schulz, Marc Daniel; Dusuel, Sébastien; Vidal, Julien

    2016-11-01

    We discuss the emergence of bound states in the low-energy spectrum of the string-net Hamiltonian in the presence of a string tension. In the ladder geometry, we show that a single bound state arises either for a finite tension or in the zero-tension limit depending on the theory considered. In the latter case, we perturbatively compute the binding energy as a function of the total quantum dimension. We also address this issue in the honeycomb lattice where the number of bound states in the topological phase depends on the total quantum dimension. Finally, the internal structure of these bound states is analyzed in the zero-tension limit.

  1. On functions of bounded semivariation

    Czech Academy of Sciences Publication Activity Database

    Monteiro, Giselle Antunes

    2015-01-01

    Roč. 40, č. 2 (2015), s. 233-276 ISSN 0147-1937 Institutional support: RVO:67985840 Keywords : semivariation * functions of bounded variation * regulated functions Subject RIV: BA - General Mathematics http://projecteuclid.org/euclid.rae/1491271216

  2. Computational Lower Bounds Using Diagonalization

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 7. Computational Lower Bounds Using Diagonalization - Languages, Turing Machines and Complexity Classes. M V Panduranga Rao. General Article Volume 14 Issue 7 July 2009 pp 682-690 ...

  3. Enhanced electron capture by fast heavy di-clusters exciting solids

    International Nuclear Information System (INIS)

    Cooney, P.J.; Faibis, A.; Kanter, E.P.; Koenig, W.; Maor, D.; Zabransky, B.J.

    1985-01-01

    The authors have studied the dependence of the charge-state-distributions of heavy-ion fragments resulting from the foil-induced dissociation of 4.2-MeV N 2 + ions on the thickness of the carbon target foil. The results were compared to those distributions measured for impact of 2.1-MeV N + projectiles. Whereas the charge-state distributions for atomic ion impact are already equilibrated in the thinnest targets used (2 μg/cm 2 ), those measured for molecular ion impact are strongly dependent on the target thickness, even for the thickest targets (100 + g/cm 2 ). The distributions for molecular-ion impact show a marked shift towards lower charge states, evidencing an enhanced electron capture probability over the case of monatomic ion impact. A quantitative model was developed to explain this phenomenon

  4. Simulation bounds for system availability

    International Nuclear Information System (INIS)

    Tietjen, G.L.; Waller, R.A.

    1976-01-01

    System availability is a dominant factor in the practicality of nuclear power electrical generating plants. A proposed model for obtaining either lower bounds or interval estimates on availability uses observed data on ''n'' failure-to-repair cycles of the system to estimate the parameters in the time-to-failure and time-to-repair models. These estimates are then used in simulating failure/repair cycles of the system. The availability estimate is obtained for each of 5000 samples of ''n'' failure/repair cycles to form a distribution of estimates. Specific percentile points of those simulated distributions are selected as lower simulation bounds or simulation interval bounds for the system availability. The method is illustrated with operational data from two nuclear plants for which an exponential time-to-failure and a lognormal time-to-repair are assumed

  5. Relativistic bound state wave functions

    International Nuclear Information System (INIS)

    Micu, L.

    2005-01-01

    A particular method of writing the bound state wave functions in relativistic form is applied to the solutions of the Dirac equation with confining potentials in order to obtain a relativistic description of a quark antiquark bound system representing a given meson. Concerning the role of the effective constituent in the present approach we first observe that without this additional constituent we couldn't expand the bound state wave function in terms of products of free states. Indeed, we notice that if the wave function depends on the relative coordinates only, all the expansion coefficients would be infinite. Secondly we remark that the effective constituent enabled us to give a Lorentz covariant meaning to the potential energy of the bound system which is now seen as the 4th component of a 4-momentum. On the other side, by relating the effective constituent to the quantum fluctuations of the background field which generate the binding, we provided a justification for the existence of some spatial degrees of freedom accompanying the interaction potential. These ones, which are quite unusual in quantum mechanics, in our model are the natural consequence of the the independence of the quarks and can be seen as the effect of the imperfect cancellation of the vector momenta during the quantum fluctuations. Related with all these we remark that the adequate representation for the relativistic description of a bound system is the momentum representation, because of the transparent and easy way of writing the conservation laws and the transformation properties of the wave functions. The only condition to be fulfilled is to find a suitable way to take into account the potential energy of the bound system. A particular feature of the present approach is that the confining forces are due to a kind of glue where both quarks are embedded. This recalls other bound state models where the wave function is factorized in terms of constituent wave functions and the confinement is

  6. Four-quark bound states

    International Nuclear Information System (INIS)

    Zouzou, S.

    1986-01-01

    In the framework of simple non-relativistic potential models, we examine the system consisting of two quarks and two antiquarks with equal or unequal masses. We search for possible bound states below the threshold for the spontaneous dissociation into two mesons. We solve the four body problem by empirical or systematic variational methods and we include the virtual meson-meson components of the wave function. With standard two-body potentials, there is no proliferation of multiquarks. With unequal quark masses, we obtain however exotic (anti Qanti Qqq) bound states with a baryonic antidiquark-quark-quark structure very analogous to the heavy flavoured (Q'qq) baryons. (orig.)

  7. Bound entanglement and local realism

    International Nuclear Information System (INIS)

    Kaszlikowski, Dagomir; Zukowski, Marek; Gnacinski, Piotr

    2002-01-01

    We show using a numerical approach, which gives necessary and sufficient conditions for the existence of local realism, that the bound entangled state presented in Bennett et al. [Phys. Rev. Lett. 82, 5385 (1999)] admits a local and realistic description. We also find the lowest possible amount of some appropriate entangled state that must be ad-mixed to the bound entangled state so that the resulting density operator has no local and realistic description and as such can be useful in quantum communication and quantum computation

  8. Semiclassical bounds in magnetic bottles

    Czech Academy of Sciences Publication Activity Database

    Barseghyan, Diana; Exner, Pavel; Kovařík, H.; Weidl, T.

    2016-01-01

    Roč. 28, č. 1 (2016), s. 1650002 ISSN 0129-055X R&D Projects: GA ČR(CZ) GA14-06818S Institutional support: RVO:61389005 Keywords : magnetic Laplacian * discrete spectrum * eigenvalue bounds Subject RIV: BE - Theoretical Physics Impact factor: 1.426, year: 2016

  9. Positivity bounds for Sivers functions

    International Nuclear Information System (INIS)

    Kang Zhongbo; Soffer, Jacques

    2011-01-01

    We generalize a positivity constraint derived initially for parity-conserving processes to the parity-violating ones, and use it to derive non-trivial bounds on several Sivers functions, entering in the theoretical description of single spin asymmetry for various processes.

  10. Bound states of 'dressed' particles

    International Nuclear Information System (INIS)

    Shirokov, M.I.

    1994-01-01

    A new approach to the problem of bound states in relativistic quantum field theories is suggested. It uses the creation - destruction operators of 'dresses' particles which have been granted by Faddeev's (1963) 'dressing' formalism. Peculiarities of the proposed approach as compared to the known ones are discussed. 8 refs. (author)

  11. Quantum lower bound for sorting

    OpenAIRE

    Shi, Yaoyun

    2000-01-01

    We prove that \\Omega(n log(n)) comparisons are necessary for any quantum algorithm that sorts n numbers with high success probability and uses only comparisons. If no error is allowed, at least 0.110nlog_2(n) - 0.067n + O(1) comparisons must be made. The previous known lower bound is \\Omega(n).

  12. Unconditional lower bounds against advice

    NARCIS (Netherlands)

    Buhrman, H.; Fortnow, L.; Santhanam, R.

    2009-01-01

    We show several unconditional lower bounds for exponential time classes against polynomial time classes with advice, including: (1) For any constant c, NEXP not in P^{NP[n^c]} (2) For any constant c, MAEXP not in MA/n^c (3) BPEXP not in BPP/n^{o(1)}. It was previously unknown even whether NEXP in

  13. Thick electrodes including nanoparticles having electroactive materials and methods of making same

    Science.gov (United States)

    Xiao, Jie; Lu, Dongping; Liu, Jun; Zhang, Jiguang; Graff, Gordon L.

    2017-02-21

    Electrodes having nanostructure and/or utilizing nanoparticles of active materials and having high mass loadings of the active materials can be made to be physically robust and free of cracks and pinholes. The electrodes include nanoparticles having electroactive material, which nanoparticles are aggregated with carbon into larger secondary particles. The secondary particles can be bound with a binder to form the electrode.

  14. Binding energies of two deltas bound states

    International Nuclear Information System (INIS)

    Sato, Hiroshi; Saito, Koichi.

    1982-06-01

    Bound states of the two-deltas system are investigated by employing the realistic one boson exchange potential. It is found that there exist many bound states in each isospin channel and also found that the tensor interaction plays important role in producing these bound states. Relationship between these bound states and dibaryon resonances is discussed. (J.P.N.)

  15. A symmetric Roos bound for linear codes

    NARCIS (Netherlands)

    Duursma, I.M.; Pellikaan, G.R.

    2006-01-01

    The van Lint–Wilson AB-method yields a short proof of the Roos bound for the minimum distance of a cyclic code. We use the AB-method to obtain a different bound for the weights of a linear code. In contrast to the Roos bound, the role of the codes A and B in our bound is symmetric. We use the bound

  16. Computer simulation of bounded plasmas

    International Nuclear Information System (INIS)

    Lawson, W.S.

    1987-01-01

    The problems of simulating a one-dimensional bounded plasma system using particles in a gridded space are systematically explored and solutions to them are given. Such problems include the injection of particles at the boundaries, the solution of Poisson's equation, and the inclusion of an external circuit between the confining boundaries. A recently discovered artificial cooling effect is explained as being a side-effect of quiet injection, and its potential for causing serious but subtle errors in bounded simulation is noted. The methods described in the first part of the thesis are then applied to the simulation of an extension of the Pierce diode problem, specifically a Pierce diode modified by an external circuit between the electrodes. The results of these simulations agree to high accuracy with theory when a theory exists, and also show some interesting chaotic behavior in certain parameter regimes. The chaotic behavior is described in detail

  17. Bounded Rationality in Transposition Processes

    DEFF Research Database (Denmark)

    Vollaard, Hans; Martinsen, Dorte Sindbjerg

    2014-01-01

    Studies explaining the timeliness and correctness of the transposition of EU directives into national legislation have provided rather inconclusive findings. They do not offer a clear-cut prediction concerning the transposition of the patients’ rights directive, which is one of the first that con......Studies explaining the timeliness and correctness of the transposition of EU directives into national legislation have provided rather inconclusive findings. They do not offer a clear-cut prediction concerning the transposition of the patients’ rights directive, which is one of the first...... that concerns the organisation and financing of national healthcare systems. This article applies the perspective of bounded rationality to explain (irregularities in) the timely and correct transposition of EU directives. The cognitive and organisational constraints long posited by the bounded rationality...

  18. 78 FR 18326 - Agency Information Collection Activities; Comment Request; Upward Bound and Upward Bound Math...

    Science.gov (United States)

    2013-03-26

    ...; Comment Request; Upward Bound and Upward Bound Math Science Annual Performance Report AGENCY: The Office... considered public records. Title of Collection: Upward Bound and Upward Bound Math Science Annual Performance...) and Upward Bound Math and Science (UBMS) Programs. The Department is requesting a new APR because of...

  19. Spectrum of gluino bound states

    International Nuclear Information System (INIS)

    Chanowitz, M.; Sharpe, S.; California Univ., Berkeley

    1983-01-01

    Using the bag model to first order in αsub(s) we find that if light gluinos exist they will appear as constituents of electrically charged bound states which are stable against strong interaction decay. We review the present experimental constraints and conclude that light, long-lived charged hadrons containing gluinos might exist with lifetimes between 2x10 - 8 and 10 - 14 s. (orig.)

  20. Cyclotron transitions of bound ions

    Science.gov (United States)

    Bezchastnov, Victor G.; Pavlov, George G.

    2017-06-01

    A charged particle in a magnetic field possesses discrete energy levels associated with particle rotation around the field lines. The radiative transitions between these levels are the well-known cyclotron transitions. We show that a bound complex of particles with a nonzero net charge displays analogous transitions between the states of confined motion of the entire complex in the field. The latter bound-ion cyclotron transitions are affected by a coupling between the collective and internal motions of the complex and, as a result, differ from the transitions of a "reference" bare ion with the same mass and charge. We analyze the cyclotron transitions for complex ions by including the coupling within a rigorous quantum approach. Particular attention is paid to comparison of the transition energies and oscillator strengths to those of the bare ion. Selection rules based on integrals of collective motion are derived for the bound-ion cyclotron transitions analytically, and the perturbation and coupled-channel approaches are developed to study the transitions quantitatively. Representative examples are considered and discussed for positive and negative atomic and cluster ions.

  1. Labeling schemes for bounded degree graphs

    DEFF Research Database (Denmark)

    Adjiashvili, David; Rotbart, Noy Galil

    2014-01-01

    We investigate adjacency labeling schemes for graphs of bounded degree Δ = O(1). In particular, we present an optimal (up to an additive constant) log n + O(1) adjacency labeling scheme for bounded degree trees. The latter scheme is derived from a labeling scheme for bounded degree outerplanar...... graphs. Our results complement a similar bound recently obtained for bounded depth trees [Fraigniaud and Korman, SODA 2010], and may provide new insights for closing the long standing gap for adjacency in trees [Alstrup and Rauhe, FOCS 2002]. We also provide improved labeling schemes for bounded degree...

  2. Detection of magnetic nanoparticles with magnetoencephalography

    Energy Technology Data Exchange (ETDEWEB)

    Jia Wenyan [Department of Neurosurgery, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Xu, Guizhi [Department of Neurosurgery, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Department of Biomedical Engineering, Hebei University of Technology, Tianjin, 300130 (China); Sclabassi, Robert J. [Department of Neurosurgery, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Zhu Jiangang [Department of Electrical and Computer Engineering, Carnegie Melon University, Pittsburgh, PA 15213 (United States); Bagic, Anto [Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Sun Mingui [Department of Neurosurgery, University of Pittsburgh, Pittsburgh, PA 15260 (United States)], E-mail: mrsun@neuronet.pitt.edu

    2008-04-15

    Superconducting quantum interference devices (SQUIDs) have been widely utilized in biomedical applications due to their extremely high sensitivity to magnetic signals. The present study explores the feasibility of a new type of nanotechnology-based imaging method using standard clinical magnetoencephalographic (MEG) systems equipped with SQUID sensors. Previous studies have shown that biological targets labeled with non-toxic, magnetized nanoparticles can be imaged by measuring the magnetic field generated by these particles. In this work, we demonstrate that (1) the magnetic signals from certain nanoparticles can be detected without magnetization using standard clinical MEG, (2) for some types of nanoparticles, only bound particles produce detectable signals, and (3) the magnetic field of particles several hours after magnetization is significantly stronger than that of un-magnetized particles. These findings hold promise in facilitating the potential application of magnetic nanoparticles to in vivo tumor imaging. The minimum amount of nanoparticles that produce detectable signals is predicted by theoretical modeling and computer simulation.

  3. The algebras of bounded and essentially bounded Lebesgue measurable functions

    Directory of Open Access Journals (Sweden)

    Mortini Raymond

    2017-04-01

    Full Text Available Let X be a set in ℝn with positive Lebesgue measure. It is well known that the spectrum of the algebra L∞(X of (equivalence classes of essentially bounded, complex-valued, measurable functions on X is an extremely disconnected compact Hausdorff space.We show, by elementary methods, that the spectrum M of the algebra ℒb(X, ℂ of all bounded measurable functions on X is not extremely disconnected, though totally disconnected. Let ∆ = { δx : x ∈ X} be the set of point evaluations and let g be the Gelfand topology on M. Then (∆, g is homeomorphic to (X, Τdis,where Tdis is the discrete topology. Moreover, ∆ is a dense subset of the spectrum M of ℒb(X, ℂ. Finally, the hull h(I, (which is homeomorphic to M(L∞(X, of the ideal of all functions in ℒb(X, ℂ vanishing almost everywhere on X is a nowhere dense and extremely disconnected subset of the Corona M \\ ∆ of ℒb(X, ℂ.

  4. Voronoi Diagrams Without Bounding Boxes

    Science.gov (United States)

    Sang, E. T. K.

    2015-10-01

    We present a technique for presenting geographic data in Voronoi diagrams without having to specify a bounding box. The method restricts Voronoi cells to points within a user-defined distance of the data points. The mathematical foundation of the approach is presented as well. The cell clipping method is particularly useful for presenting geographic data that is spread in an irregular way over a map, as for example the Dutch dialect data displayed in Figure 2. The automatic generation of reasonable cell boundaries also makes redundant a frequently used solution to this problem that requires data owners to specify region boundaries, as in Goebl (2010) and Nerbonne et al (2011).

  5. Sensitivity analysis using probability bounding

    International Nuclear Information System (INIS)

    Ferson, Scott; Troy Tucker, W.

    2006-01-01

    Probability bounds analysis (PBA) provides analysts a convenient means to characterize the neighborhood of possible results that would be obtained from plausible alternative inputs in probabilistic calculations. We show the relationship between PBA and the methods of interval analysis and probabilistic uncertainty analysis from which it is jointly derived, and indicate how the method can be used to assess the quality of probabilistic models such as those developed in Monte Carlo simulations for risk analyses. We also illustrate how a sensitivity analysis can be conducted within a PBA by pinching inputs to precise distributions or real values

  6. Bounded Densities and Their Derivatives

    DEFF Research Database (Denmark)

    Kozine, Igor; Krymsky, V.

    2009-01-01

    This paper describes how one can compute interval-valued statistical measures given limited information about the underlying distribution. The particular focus is on a bounded derivative of a probability density function and its combination with other available statistical evidence for computing ...... quantities of interest. To be able to utilise the evidence about the derivative it is suggested to adapt the ‘conventional’ problem statement to variational calculus and the way to do so is demonstrated. A number of examples are given throughout the paper....

  7. Removal of bound metal fasteners

    Science.gov (United States)

    Kramer, R. F.

    1981-04-01

    This project explored the removal of bound metal fasteners through the use of ultrasonically assisted wrenches. Two wrenches were designed, fabricated and tested. Previous studies had indicated an increase in thread tension for a given torque application under the influence of ultrasonics. Based on this, the loosening of seized and corroded fasteners with the aid of ultrasonics was explored. Experimental data confirmed our prior analysis of the torque-tension relationship under the influence of ultrasonics; however, our progress did not satisfy the requirements necessary to loosen seized studs in a shipyard environment.

  8. Space mappings with bounded distortion

    CERN Document Server

    Reshetnyak, Yu G

    1989-01-01

    This book is intended for researchers and students concerned with questions in analysis and function theory. The author provides an exposition of the main results obtained in recent years by Soviet and other mathematicians in the theory of mappings with bounded distortion, an active direction in contemporary mathematics. The mathematical tools presented can be applied to a broad spectrum of problems that go beyond the context of the main topic of investigation. For a number of questions in the theory of partial differential equations and the theory of functions with generalized derivatives, this is the first time they have appeared in an internationally distributed monograph.

  9. Determining Normal-Distribution Tolerance Bounds Graphically

    Science.gov (United States)

    Mezzacappa, M. A.

    1983-01-01

    Graphical method requires calculations and table lookup. Distribution established from only three points: mean upper and lower confidence bounds and lower confidence bound of standard deviation. Method requires only few calculations with simple equations. Graphical procedure establishes best-fit line for measured data and bounds for selected confidence level and any distribution percentile.

  10. On semidefinite programming bounds for graph bandwidth

    NARCIS (Netherlands)

    de Klerk, E.; Nagy, M.; Sotirov, R.

    2013-01-01

    In this paper, we propose two new lower bounds on graph bandwidth and cyclic bandwidth based on semidefinite programming (SDP) relaxations of the quadratic assignment problem. We compare the new bounds with two other SDP bounds reported in [A. Blum, G. Konjevod, R. Ravi, and S. Vempala,

  11. Observational Bounds on Cosmic Doomsday

    Energy Technology Data Exchange (ETDEWEB)

    Shmakova, Marina

    2003-07-11

    Recently it was found, in a broad class of models, that the dark energy density may change its sign during the evolution of the universe. This may lead to a global collapse of the universe within the time t{sub c} {approx} 10{sup 10}-10{sup 11} years. Our goal is to find what bounds on the future lifetime of the universe can be placed by the next generation of cosmological observations. As an example, we investigate the simplest model of dark energy with a linear potential V({phi}) = V{sub 0}(1 + {alpha}{phi}). This model can describe the present stage of acceleration of the universe if {alpha} is small enough. However, eventually the field {phi} rolls down, V({phi}) becomes negative, and the universe collapses. The existing observational data indicate that the universe described by this model will collapse not earlier than t{sub c} {approx_equal} 10 billion years from the present moment. We show that the data from SNAP and Planck satellites may extend the bound on the ''doomsday'' time to tc 40 billion years at the 95% confidence level.

  12. Quantum bounds on Bell inequalities

    Science.gov (United States)

    Pál, Károly F.; Vértesi, Tamás

    2009-02-01

    We have determined the maximum quantum violation of 241 tight bipartite Bell inequalities with up to five two-outcome measurement settings per party by constructing the appropriate measurement operators in up to six-dimensional complex and eight-dimensional real-component Hilbert spaces using numerical optimization. Out of these inequalities 129 have been introduced here. In 43 cases higher-dimensional component spaces gave larger violation than qubits, and in three occasions the maximum was achieved with six-dimensional spaces. We have also calculated upper bounds on these Bell inequalities using a method proposed recently. For all but 20 inequalities the best solution found matched the upper bound. Surprisingly, the simplest inequality of the set examined, with only three measurement settings per party, was not among them, despite the high dimensionality of the Hilbert space considered. We also computed detection threshold efficiencies for the maximally entangled qubit pair. These could be lowered in several instances if degenerate measurements were also allowed.

  13. Capacity Bounds for Parallel Optical Wireless Channels

    KAUST Repository

    Chaaban, Anas; Rezki, Zouheir; Alouini, Mohamed-Slim

    2016-01-01

    A system consisting of parallel optical wireless channels with a total average intensity constraint is studied. Capacity upper and lower bounds for this system are derived. Under perfect channel-state information at the transmitter (CSIT), the bounds have to be optimized with respect to the power allocation over the parallel channels. The optimization of the lower bound is non-convex, however, the KKT conditions can be used to find a list of possible solutions one of which is optimal. The optimal solution can then be found by an exhaustive search algorithm, which is computationally expensive. To overcome this, we propose low-complexity power allocation algorithms which are nearly optimal. The optimized capacity lower bound nearly coincides with the capacity at high SNR. Without CSIT, our capacity bounds lead to upper and lower bounds on the outage probability. The outage probability bounds meet at high SNR. The system with average and peak intensity constraints is also discussed.

  14. VORONOI DIAGRAMS WITHOUT BOUNDING BOXES

    Directory of Open Access Journals (Sweden)

    E. T. K. Sang

    2015-10-01

    Full Text Available We present a technique for presenting geographic data in Voronoi diagrams without having to specify a bounding box. The method restricts Voronoi cells to points within a user-defined distance of the data points. The mathematical foundation of the approach is presented as well. The cell clipping method is particularly useful for presenting geographic data that is spread in an irregular way over a map, as for example the Dutch dialect data displayed in Figure 2. The automatic generation of reasonable cell boundaries also makes redundant a frequently used solution to this problem that requires data owners to specify region boundaries, as in Goebl (2010 and Nerbonne et al (2011.

  15. Spectral computations for bounded operators

    CERN Document Server

    Ahues, Mario; Limaye, Balmohan

    2001-01-01

    Exact eigenvalues, eigenvectors, and principal vectors of operators with infinite dimensional ranges can rarely be found. Therefore, one must approximate such operators by finite rank operators, then solve the original eigenvalue problem approximately. Serving as both an outstanding text for graduate students and as a source of current results for research scientists, Spectral Computations for Bounded Operators addresses the issue of solving eigenvalue problems for operators on infinite dimensional spaces. From a review of classical spectral theory through concrete approximation techniques to finite dimensional situations that can be implemented on a computer, this volume illustrates the marriage of pure and applied mathematics. It contains a variety of recent developments, including a new type of approximation that encompasses a variety of approximation methods but is simple to verify in practice. It also suggests a new stopping criterion for the QR Method and outlines advances in both the iterative refineme...

  16. (BDMCA) Nanoparticles

    African Journals Online (AJOL)

    Methods: Nanoparticle formulations were fabricated by a double emulsion solvent evaporation technique using polycaprolactone as the polymer. The nanoparticles were characterised for drug content, particles size, in vitro drug release and the drug-polymer interaction. The in vivo properties of the formulations in male ...

  17. Intermetallic nanoparticles

    Science.gov (United States)

    Singh, Dileep; Yusufoglu, Yusuf; Timofeeva, Elena; Routbort, Jules

    2015-07-14

    A process for preparing intermetallic nanoparticles of two or more metals is provided. In particular, the process includes the steps: a) dispersing nanoparticles of a first metal in a solvent to prepare a first metal solution, b) forming a reaction mixture with the first metal solution and a reducing agent, c) heating the reaction mixture to a reaction temperature; and d) adding a second metal solution containing a salt of a second metal to the reaction mixture. During this process, intermetallic nanoparticles, which contain a compound with the first and second metals are formed. The intermetallic nanoparticles with uniform size and a narrow size distribution is also provided. An electrochemical device such as a battery with the intermetallic nanoparticles is also provided.

  18. Gold Nanoparticle Labels Amplify Ellipsometric Signals

    Science.gov (United States)

    Venkatasubbarao, Srivatsa

    2008-01-01

    The ellipsometric method reported in the immediately preceding article was developed in conjunction with a method of using gold nanoparticles as labels on biomolecules that one seeks to detect. The purpose of the labeling is to exploit the optical properties of the gold nanoparticles in order to amplify the measurable ellipsometric effects and thereby to enable ultrasensitive detection of the labeled biomolecules without need to develop more-complex ellipsometric instrumentation. The colorimetric, polarization, light-scattering, and other optical properties of nanoparticles depend on their sizes and shapes. In the present method, these size-and-shape-dependent properties are used to magnify the polarization of scattered light and the diattenuation and retardance of signals derived from ellipsometry. The size-and-shape-dependent optical properties of the nanoparticles make it possible to interrogate the nanoparticles by use of light of various wavelengths, as appropriate, to optimally detect particles of a specific type at high sensitivity. Hence, by incorporating gold nanoparticles bound to biomolecules as primary or secondary labels, the performance of ellipsometry as a means of detecting the biomolecules can be improved. The use of gold nanoparticles as labels in ellipsometry has been found to afford sensitivity that equals or exceeds the sensitivity achieved by use of fluorescence-based methods. Potential applications for ellipsometric detection of gold nanoparticle-labeled biomolecules include monitoring molecules of interest in biological samples, in-vitro diagnostics, process monitoring, general environmental monitoring, and detection of biohazards.

  19. Determination of nanoparticle surface coatings and nanoparticle purity using microscale thermogravimetric analysis.

    Science.gov (United States)

    Mansfield, Elisabeth; Tyner, Katherine M; Poling, Christopher M; Blacklock, Jenifer L

    2014-02-04

    The use of nanoparticles in some applications (i.e., nanomedical, nanofiltration, or nanoelectronic) requires small samples with well-known purities and composition. In addition, when nanoparticles are introduced into complex environments (e.g., biological fluids), the particles may become coated with matter, such as proteins or lipid layers. Many of today's analytical techniques are not able to address small-scale samples of nanoparticles to determine purity and the presence of surface coatings. Through the use of an elevated-temperature quartz crystal microbalance (QCM) method we call microscale thermogravimetric analysis, or μ-TGA, the nanoparticle purity, as well as the presence of any surface coatings of nanomaterials, can be measured. Microscale thermogravimetric analysis is used to determine the presence and amount of surface-bound ligand coverage on gold nanoparticles and confirm the presence of a poly(ethylene glycol) coating on SiO2 nanoparticles. Results are compared to traditional analytical techniques to demonstrate reproducibility and validity of μ-TGA for determining the presence of nanoparticle surface coatings. Carbon nanotube samples are also analyzed and compared to conventional TGA. The results demonstrate μ-TGA is a valid method for quantitative determination of the coatings on nanoparticles, and in some cases, can provide purity and compositional data of the nanoparticles themselves.

  20. Instanton bound states in ABJM theory

    Energy Technology Data Exchange (ETDEWEB)

    Hatsuda, Yasuyuki [DESY Hamburg (Germany). Theory Group; Tokyo Institute of Technology (Japan). Dept. of Physics; Moriyama, Sanefumi [Nagoya Univ. (Japan). Kobayashi Maskawa Inst. and Graduate School of Mathematics; Okuyama, Kazumi [Shinshu Univ., Matsumoto, Nagano (Japan). Dept. of Physics

    2013-06-15

    The partition function of the ABJM theory receives non-perturbative corrections due to instanton effects. We study these non-perturbative corrections, including bound states of worldsheet instantons and membrane instantons, in the Fermi-gas approach. We require that the total non-perturbative correction should be always finite for arbitrary Chern-Simons level. This finiteness is realized quite non-trivially because each bound state contribution naively diverges at some levels. The poles of each contribution should be canceled out in total. We use this pole cancellation mechanism to find unknown bound state corrections from known ones. We conjecture a general expression of the bound state contribution. Summing up all the bound state contributions, we find that the effect of bound states is simply incorporated into the worldsheet instanton correction by a redefinition of the chemical potential in the Fermi-gas system. Analytic expressions of the 3- and 4-membrane instanton corrections are also proposed.

  1. Bounded elements in Locally C*-algebras

    International Nuclear Information System (INIS)

    El Harti, Rachid

    2001-09-01

    In order to get more useful information about Locally C*-algebras, we introduce in this paper the notion of bounded elements. First, we study the connection between bounded elements and spectrally bounded elements. Some structural results of Locally C*-algebras are established in Theorems 1 , 2 and 3. As an immediate consequence of Theorem 3, we give a characterization of the connected component of the identity in the group of unitary elements for a Locally C*-algebra. (author)

  2. Fuzzy upper bounds and their applications

    Energy Technology Data Exchange (ETDEWEB)

    Soleimani-damaneh, M. [Department of Mathematics, Faculty of Mathematical Science and Computer Engineering, Teacher Training University, 599 Taleghani Avenue, Tehran 15618 (Iran, Islamic Republic of)], E-mail: soleimani_d@yahoo.com

    2008-04-15

    This paper considers the concept of fuzzy upper bounds and provides some relevant applications. Considering a fuzzy DEA model, the existence of a fuzzy upper bound for the objective function of the model is shown and an effective approach to solve that model is introduced. Some dual interpretations are provided, which are useful for practical purposes. Applications of the concept of fuzzy upper bounds in two physical problems are pointed out.

  3. Bounded cohomology of discrete groups

    CERN Document Server

    Frigerio, Roberto

    2017-01-01

    The author manages a near perfect equilibrium between necessary technicalities (always well motivated) and geometric intuition, leading the readers from the first simple definition to the most striking applications of the theory in 13 very pleasant chapters. This book can serve as an ideal textbook for a graduate topics course on the subject and become the much-needed standard reference on Gromov's beautiful theory. -Michelle Bucher The theory of bounded cohomology, introduced by Gromov in the late 1980s, has had powerful applications in geometric group theory and the geometry and topology of manifolds, and has been the topic of active research continuing to this day. This monograph provides a unified, self-contained introduction to the theory and its applications, making it accessible to a student who has completed a first course in algebraic topology and manifold theory. The book can be used as a source for research projects for master's students, as a thorough introduction to the field for graduate student...

  4. Some Improved Nonperturbative Bounds for Fermionic Expansions

    Energy Technology Data Exchange (ETDEWEB)

    Lohmann, Martin, E-mail: marlohmann@gmail.com [Universita di Roma Tre, Dipartimento di Matematica (Italy)

    2016-06-15

    We reconsider the Gram-Hadamard bound as it is used in constructive quantum field theory and many body physics to prove convergence of Fermionic perturbative expansions. Our approach uses a recursion for the amplitudes of the expansion, discovered in a model problem by Djokic (2013). It explains the standard way to bound the expansion from a new point of view, and for some of the amplitudes provides new bounds, which avoid the use of Fourier transform, and are therefore superior to the standard bounds for models like the cold interacting Fermi gas.

  5. (shell) nanoparticles

    Indian Academy of Sciences (India)

    the quasistatic approximation shows good agreement with the Mie theory results. .... medium, respectively, and f = (rcore/rshell)1/3 is the fraction of the total particle ..... [27] Michael Quinten, Optical properties of nanoparticle systems: Mie and ...

  6. Variational lower bound on the scattering length

    International Nuclear Information System (INIS)

    Rosenberg, L.; Spruch, L.

    1975-01-01

    The scattering length A characterizes the zero-energy scattering of one system by another. It was shown some time ago that a variational upper bound on A could be obtained using methods, of the Rayleigh-Ritz type, which are commonly employed to obtain upper bounds on energy eigenvalues. Here we formulate a method for obtaining a variational lower bound on A. Once again the essential idea is to express the scattering length as a variational estimate plus an error term and then to reduce the problem of bounding the error term to one involving bounds on energy eigenvalues. In particular, the variational lower bound on A is rigorously established provided a certin modified Hamiltonian can be shown to have no discrete states lying below the level of the continuum threshold. It is unfortunately true that necessary conditions for the existence of bound states are not available for multiparticle systems in general. However, in the case of positron-atom scattering the adiabatic approximation can be introduced as an (essentially) solvable comparison problem to rigorously establish the nonexistence of bound states of the modified Hamiltonian. It has recently been shown how the validity of the variational upper bound on A can be maintained when the target ground-state wave function is imprecisely known. Similar methods can be used to maintain the variational lower bound on A. Since the bound is variational, the error in the calculated scattering length will be of second order in the error in the wave function. The use of the adiabatic approximation in the present context places no limitation in principle on the accuracy achievable

  7. Incorporating functionalized polyethylene glycol lipids into reprecipitated conjugated polymer nanoparticles for bioconjugation and targeted labeling of cells

    Science.gov (United States)

    Kandel, Prakash K.; Fernando, Lawrence P.; Ackroyd, P. Christine; Christensen, Kenneth A.

    2011-03-01

    We report a simple and rapid method to prepare extremely bright, functionalized, stable, and biocompatible conjugated polymer nanoparticles incorporating functionalized polyethylene glycol (PEG) lipids by reprecipitation. These nanoparticles retain the fundamental spectroscopic properties of conjugated polymer nanoparticles prepared without PEG lipid, but demonstrate greater hydrophilicity and quantum yield compared to unmodified conjugated polymer nanoparticles. The sizes of these nanoparticles, as determined by TEM, were 21-26 nm. Notably, these nanoparticles were prepared with several PEG lipid functional end groups, including biotin and carboxy moieties that can be easily conjugated to biomolecules. We have demonstrated the availability of these end groups for functionalization using the interaction of biotin PEG lipid conjugated polymer nanoparticles with streptavidin. Biotinylated PEG lipid conjugated polymer nanoparticles bound streptavidin-linked magnetic beads, while carboxy and methoxy PEG lipid modified nanoparticles did not. Similarly, biotinylated PEG lipid conjugated polymer nanoparticles bound streptavidin-coated glass slides and could be visualized as diffraction-limited spots, while nanoparticles without PEG lipid or with non-biotin PEG lipid end groups were not bound. To demonstrate that nanoparticle functionalization could be used for targeted labelling of specific cellular proteins, biotinylated PEG lipid conjugated polymer nanoparticles were bound to biotinylated anti-CD16/32 antibodies on J774A.1 cell surface receptors, using streptavidin as a linker. This work represents the first demonstration of targeted delivery of conjugated polymer nanoparticles and demonstrates the utility of these new nanoparticles for fluorescence based imaging and sensing.We report a simple and rapid method to prepare extremely bright, functionalized, stable, and biocompatible conjugated polymer nanoparticles incorporating functionalized polyethylene glycol (PEG

  8. Stacked spheres and lower bound theorem

    Indian Academy of Sciences (India)

    BASUDEB DATTA

    2011-11-20

    Nov 20, 2011 ... Preliminaries. Lower bound theorem. On going work. Definitions. An n-simplex is a convex hull of n + 1 affinely independent points. (called vertices) in some Euclidean space R. N . Stacked spheres and lower bound theorem. Basudeb Datta. Indian Institute of Science. 2 / 27 ...

  9. A strongly quasiconvex PAC-Bayesian bound

    DEFF Research Database (Denmark)

    Thiemann, Niklas; Igel, Christian; Wintenberger, Olivier

    2017-01-01

    We propose a new PAC-Bayesian bound and a way of constructing a hypothesis space, so that the bound is convex in the posterior distribution and also convex in a trade-off parameter between empirical performance of the posterior distribution and its complexity. The complexity is measured by the Ku...

  10. On the range of completely bounded maps

    Directory of Open Access Journals (Sweden)

    Richard I. Loebl

    1978-01-01

    Full Text Available It is shown that if every bounded linear map from a C*-algebra α to a von Neumann algebra β is completely bounded, then either α is finite-dimensional or β⫅⊗Mn, where is a commutative von Neumann algebra and Mn is the algebra of n×n complex matrices.

  11. Bounds in the location-allocation problem

    DEFF Research Database (Denmark)

    Juel, Henrik

    1981-01-01

    Develops a family of stronger lower bounds on the objective function value of the location-allocation problem. Solution methods proposed to solve problems in location-allocation; Efforts to develop a more efficient bound solution procedure; Determination of the locations of the sources....

  12. Experimental evidence for bounds on quantum correlations.

    Science.gov (United States)

    Bovino, F A; Castagnoli, G; Degiovanni, I P; Castelletto, S

    2004-02-13

    We implemented the experiment proposed by Cabello in the preceding Letter to test the bounds of quantum correlation. As expected from the theory we found that, for certain choices of local observables, Tsirelson's bound of the Clauser-Horne-Shimony-Holt inequality (2 x square root of 2) is not reached by any quantum states.

  13. Exponential Lower Bounds For Policy Iteration

    OpenAIRE

    Fearnley, John

    2010-01-01

    We study policy iteration for infinite-horizon Markov decision processes. It has recently been shown policy iteration style algorithms have exponential lower bounds in a two player game setting. We extend these lower bounds to Markov decision processes with the total reward and average-reward optimality criteria.

  14. Conductivity bound from dirty black holes

    Energy Technology Data Exchange (ETDEWEB)

    Bitaghsir Fadafan, Kazem, E-mail: bitaghsir@shahroodut.ac.ir

    2016-11-10

    We propose a lower bound of the dc electrical conductivity in strongly disordered, strongly interacting quantum field theories using holography. We study linear response of black holes with broken translational symmetry in Einstein–Maxwell-dilaton theories of gravity. Using the generalized Stokes equations at the horizon, we derive the lower bound of the electrical conductivity for the dual two dimensional disordered field theory.

  15. No-arbitrage bounds for financial scenarios

    DEFF Research Database (Denmark)

    Geyer, Alois; Hanke, Michael; Weissensteiner, Alex

    2014-01-01

    We derive no-arbitrage bounds for expected excess returns to generate scenarios used in financial applications. The bounds allow to distinguish three regions: one where arbitrage opportunities will never exist, a second where arbitrage may be present, and a third, where arbitrage opportunities...

  16. SHARP ENTRYWISE PERTURBATION BOUNDS FOR MARKOV CHAINS.

    Science.gov (United States)

    Thiede, Erik; VAN Koten, Brian; Weare, Jonathan

    For many Markov chains of practical interest, the invariant distribution is extremely sensitive to perturbations of some entries of the transition matrix, but insensitive to others; we give an example of such a chain, motivated by a problem in computational statistical physics. We have derived perturbation bounds on the relative error of the invariant distribution that reveal these variations in sensitivity. Our bounds are sharp, we do not impose any structural assumptions on the transition matrix or on the perturbation, and computing the bounds has the same complexity as computing the invariant distribution or computing other bounds in the literature. Moreover, our bounds have a simple interpretation in terms of hitting times, which can be used to draw intuitive but rigorous conclusions about the sensitivity of a chain to various types of perturbations.

  17. New bounds on isotropic Lorentz violation

    International Nuclear Information System (INIS)

    Carone, Christopher D.; Sher, Marc; Vanderhaeghen, Marc

    2006-01-01

    Violations of Lorentz invariance that appear via operators of dimension four or less are completely parametrized in the Standard Model Extension (SME). In the pure photonic sector of the SME, there are 19 dimensionless, Lorentz-violating parameters. Eighteen of these have experimental upper bounds ranging between 10 -11 and 10 -32 ; the remaining parameter, k-tilde tr , is isotropic and has a much weaker bound of order 10 -4 . In this Brief Report, we point out that k-tilde tr gives a significant contribution to the anomalous magnetic moment of the electron and find a new upper bound of order 10 -8 . With reasonable assumptions, we further show that this bound may be improved to 10 -14 by considering the renormalization of other Lorentz-violating parameters that are more tightly constrained. Using similar renormalization arguments, we also estimate bounds on Lorentz-violating parameters in the pure gluonic sector of QCD

  18. Covariant entropy bound and loop quantum cosmology

    International Nuclear Information System (INIS)

    Ashtekar, Abhay; Wilson-Ewing, Edward

    2008-01-01

    We examine Bousso's covariant entropy bound conjecture in the context of radiation filled, spatially flat, Friedmann-Robertson-Walker models. The bound is violated near the big bang. However, the hope has been that quantum gravity effects would intervene and protect it. Loop quantum cosmology provides a near ideal setting for investigating this issue. For, on the one hand, quantum geometry effects resolve the singularity and, on the other hand, the wave function is sharply peaked at a quantum corrected but smooth geometry, which can supply the structure needed to test the bound. We find that the bound is respected. We suggest that the bound need not be an essential ingredient for a quantum gravity theory but may emerge from it under suitable circumstances.

  19. Continuous bounded cohomology of locally compact groups

    CERN Document Server

    2001-01-01

    Recent research has repeatedly led to connections between important rigidity questions and bounded cohomology. However, the latter has remained by and large intractable. This monograph introduces the functorial study of the continuous bounded cohomology for topological groups, with coefficients in Banach modules. The powerful techniques of this more general theory have successfully solved a number of the original problems in bounded cohomology. As applications, one obtains, in particular, rigidity results for actions on the circle, for representations on complex hyperbolic spaces and on Teichmüller spaces. A special effort has been made to provide detailed proofs or references in quite some generality.

  20. Positivity bounds on double parton distributions

    International Nuclear Information System (INIS)

    Diehl, Markus; Kasemets, Tomas

    2013-03-01

    Double hard scattering in proton-proton collisions is described in terms of double parton distributions. We derive bounds on these distributions that follow from their interpretation as probability densities, taking into account all possible spin correlations between two partons in an unpolarized proton. These bounds constrain the size of the polarized distributions and can for instance be used to set upper limits on the effects of spin correlations in double hard scattering. We show that the bounds are stable under leading-order DGLAP evolution to higher scales.

  1. Remarks on Bousso's covariant entropy bound

    CERN Document Server

    Mayo, A E

    2002-01-01

    Bousso's covariant entropy bound is put to the test in the context of a non-singular cosmological solution of general relativity found by Bekenstein. Although the model complies with every assumption made in Bousso's original conjecture, the entropy bound is violated due to the occurrence of negative energy density associated with the interaction of some the matter components in the model. We demonstrate how this property allows for the test model to 'elude' a proof of Bousso's conjecture which was given recently by Flanagan, Marolf and Wald. This corroborates the view that the covariant entropy bound should be applied only to stable systems for which every matter component carries positive energy density.

  2. The bound state problem and quark confinement

    International Nuclear Information System (INIS)

    Chaichian, M.; Demichev, A.P.; Nelipa, N.F.

    1980-01-01

    A quantum field-theoretic model in which quark is confined is considered. System of equations for the Green functions of colour singlet and octet bound states is obtained. The method is based on the nonperturbative Schwinger-Dyson equations with the use of Slavnov-Taylor identities. It is shown that in the framework of the model if there exist singlet, then also exist octet bound states of the quark-antiquark system. Thus in general, confinement of free quarks does not mean absence of their coloured bound states. (author)

  3. Quasi-bound states in continuum

    International Nuclear Information System (INIS)

    Nakamura, Hiroaki; Hatano, Naomichi; Garmon, Sterling; Petrosky, Tomio

    2007-08-01

    We report the prediction of quasi-bound states (resonant states with very long lifetimes) that occur in the eigenvalue continuum of propagating states for a wide region of parameter space. These quasi-bound states are generated in a quantum wire with two channels and an adatom, when the energy bands of the two channels overlap. A would-be bound state that lays just below the upper energy band is slightly destabilized by the lower energy band and thereby becomes a resonant state with a very long lifetime (a second QBIC lays above the lower energy band). (author)

  4. Biopolymeric nanoparticles

    International Nuclear Information System (INIS)

    Sundar, Sushmitha; Kundu, Joydip; Kundu, Subhas C

    2010-01-01

    This review on nanoparticles highlights the various biopolymers (proteins and polysaccharides) which have recently revolutionized the world of biocompatible and degradable natural biological materials. The methods of their fabrication, including emulsification, desolvation, coacervation and electrospray drying are described. The characterization of different parameters for a given nanoparticle, such as particle size, surface charge, morphology, stability, structure, cellular uptake, cytotoxicity, drug loading and drug release, is outlined together with the relevant measurement techniques. Applications in the fields of medicine and biotechnology are discussed along with a promising future scope. (topical review)

  5. Tight Bounds for Distributed Functional Monitoring

    DEFF Research Database (Denmark)

    Woodruff, David P.; Zhang, Qin

    2011-01-01

    $, our bound resolves their main open question. Our lower bounds are based on new direct sum theorems for approximate majority, and yield significant improvements to problems in the data stream model, improving the bound for estimating $F_p, p > 2,$ in $t$ passes from $\\tilde{\\Omega}(n^{1-2/p}/(\\eps^{2/p......} t))$ to $\\tilde{\\Omega}(n^{1-2/p}/(\\eps^{4/p} t))$, giving the first bound for estimating $F_0$ in $t$ passes of $\\Omega(1/(\\eps^2 t))$ bits of space that does not use the gap-hamming problem, and showing a distribution for the gap-hamming problem with high external information cost or super...

  6. Redshift-space limits of bound structures

    NARCIS (Netherlands)

    Duenner, Rolando; Reisenegger, Andreas; Meza, Andres; Araya, Pablo A.; Quintana, Hernan

    2007-01-01

    An exponentially expanding Universe, possibly governed by a cosmological constant, forces gravitationally bound structures to become more and more isolated, eventually becoming causally disconnected from each other and forming so-called 'island universes'. This new scenario reformulates the question

  7. Error Bounds: Necessary and Sufficient Conditions

    Czech Academy of Sciences Publication Activity Database

    Outrata, Jiří; Kruger, A.Y.; Fabian, Marián; Henrion, R.

    2010-01-01

    Roč. 18, č. 2 (2010), s. 121-149 ISSN 1877-0533 R&D Projects: GA AV ČR IAA100750802 Institutional research plan: CEZ:AV0Z10750506; CEZ:AV0Z10190503 Keywords : Error bounds * Calmness * Subdifferential * Slope Subject RIV: BA - General Mathematics Impact factor: 0.333, year: 2010 http://library.utia.cas.cz/separaty/2010/MTR/outrata-error bounds necessary and sufficient conditions.pdf

  8. Malabsorption of protein bound vitamin B12.

    OpenAIRE

    Dawson, D W; Sawers, A H; Sharma, R K

    1984-01-01

    Patients with subnormal serum vitamin B12 concentrations were tested for absorption of protein bound vitamin B12 and compared with controls. Absorption of the protein bound vitamin appeared to decrease with increasing age in healthy subjects. Differences between the result of this test and the result of the Schilling test in patients who had undergone gastric surgery were confirmed; such differences were also seen in some patients who had iron deficiency anaemia, an excessive alcohol intake, ...

  9. New Spectral Features from Bound Dark Matter

    DEFF Research Database (Denmark)

    Catena, Riccardo; Kouvaris, Chris

    2016-01-01

    We demonstrate that dark matter particles gravitationally bound to the Earth can induce a characteristic nuclear recoil signal at low energies in direct detection experiments. The new spectral feature we predict can provide the ultimate smoking gun for dark matter discovery for experiments...... with positive signal but unclear background. The new feature is universal, in that the ratio of bound over halo dark matter event rates at detectors is independent of the dark matter-nucleon cross section....

  10. Automatic bounding estimation in modified NLMS algorithm

    International Nuclear Information System (INIS)

    Shahtalebi, K.; Doost-Hoseini, A.M.

    2002-01-01

    Modified Normalized Least Mean Square algorithm, which is a sign form of Nlm based on set-membership (S M) theory in the class of optimal bounding ellipsoid (OBE) algorithms, requires a priori knowledge of error bounds that is unknown in most applications. In a special but popular case of measurement noise, a simple algorithm has been proposed. With some simulation examples the performance of algorithm is compared with Modified Normalized Least Mean Square

  11. Absolute Lower Bound on the Bounce Action

    Science.gov (United States)

    Sato, Ryosuke; Takimoto, Masahiro

    2018-03-01

    The decay rate of a false vacuum is determined by the minimal action solution of the tunneling field: bounce. In this Letter, we focus on models with scalar fields which have a canonical kinetic term in N (>2 ) dimensional Euclidean space, and derive an absolute lower bound on the bounce action. In the case of four-dimensional space, we show the bounce action is generically larger than 24 /λcr, where λcr≡max [-4 V (ϕ )/|ϕ |4] with the false vacuum being at ϕ =0 and V (0 )=0 . We derive this bound on the bounce action without solving the equation of motion explicitly. Our bound is derived by a quite simple discussion, and it provides useful information even if it is difficult to obtain the explicit form of the bounce solution. Our bound offers a sufficient condition for the stability of a false vacuum, and it is useful as a quick check on the vacuum stability for given models. Our bound can be applied to a broad class of scalar potential with any number of scalar fields. We also discuss a necessary condition for the bounce action taking a value close to this lower bound.

  12. Generalized surface tension bounds in vacuum decay

    Science.gov (United States)

    Masoumi, Ali; Paban, Sonia; Weinberg, Erick J.

    2018-02-01

    Coleman and De Luccia (CDL) showed that gravitational effects can prevent the decay by bubble nucleation of a Minkowski or AdS false vacuum. In their thin-wall approximation this happens whenever the surface tension in the bubble wall exceeds an upper bound proportional to the difference of the square roots of the true and false vacuum energy densities. Recently it was shown that there is another type of thin-wall regime that differs from that of CDL in that the radius of curvature grows substantially as one moves through the wall. Not only does the CDL derivation of the bound fail in this case, but also its very formulation becomes ambiguous because the surface tension is not well defined. We propose a definition of the surface tension and show that it obeys a bound similar in form to that of the CDL case. We then show that both thin-wall bounds are special cases of a more general bound that is satisfied for all bounce solutions with Minkowski or AdS false vacua. We discuss the limit where the parameters of the theory attain critical values and the bound is saturated. The bounce solution then disappears and a static planar domain wall solution appears in its stead. The scalar field potential then is of the form expected in supergravity, but this is only guaranteed along the trajectory in field space traced out by the bounce.

  13. Synthesis and characterization of carboxylic acid functionalized silicon nanoparticles

    Science.gov (United States)

    Shaner, Ted V.

    environment of the silicon surface of the nanoparticles. Modeling of the silicon nanoparticles and theoretical XANES spectra were also accomplished through the use of the FEFF9 software package. Results validate the infrared spectra results of more oxygen bound to the surfaces of larger silicon nanoparticles and less oxygen bound to smaller silicon nanoparticles. The photoluminescence was shown to greatly increase in yield after photoassisted exciton mediated hydrosilation. This has led to an increase of the luminescence yield of over an order of magnitude.

  14. Robust Nanoparticles

    Science.gov (United States)

    2015-01-21

    avenues for creating flexible conducting and semiconducting materials in a variety of simple or complex geometries. B. Conducting nanoparticle...coated with poly(MPC-co-DHLA) proved stable against challenging conditions, and resisted cyanide ion digestion. Au NRs coated with poly(MPC-co-DHLA

  15. Drug loaded magnetic nanoparticles for cancer therapy

    International Nuclear Information System (INIS)

    Jurgons, R; Seliger, C; Hilpert, A; Trahms, L; Odenbach, S; Alexiou, C

    2006-01-01

    Magnetic nanoparticles have been investigated for biomedical applications for more than 30 years. In medicine they are used for several approaches such as magnetic cell separation or magnetic resonance imaging (MRI). The development of biocompatible nanosized drug delivery systems for specific targeting of therapeutics is the focus of medical research, especially for the treatment of cancer and diseases of the vascular system. In an experimental cancer model, we performed targeted drug delivery and used magnetic iron oxide nanoparticles, bound to a chemotherapeutic agent, which were attracted to an experimental tumour in rabbits by an external magnetic field (magnetic drug targeting). Complete tumour remission could be achieved. An important advantage of these carriers is the possibility for detecting these nanoparticles after treatment with common imaging techniques (i.e. x-ray-tomography, magnetorelaxometry, magnetic resonance imaging), which can be correlated to histology

  16. DNA binding and aggregation by carbon nanoparticles

    International Nuclear Information System (INIS)

    An, Hongjie; Liu, Qingdai; Ji, Qiaoli; Jin, Bo

    2010-01-01

    Significant environmental and health risks due to the increasing applications of engineered nanoparticles in medical and industrial activities have been concerned by many communities. The interactions between nanomaterials and genomes have been poorly studied so far. This study examined interactions of DNA with carbon nanoparticles (CNP) using atomic force microscopy (AFM). We experimentally assessed how CNP affect DNA molecule and bacterial growth of Escherichia coli. We found that CNP were bound to the DNA molecules during the DNA replication in vivo. The results revealed that the interaction of DNA with CNP resulted in DNA molecule binding and aggregation both in vivo and in vitro in a dose-dependent manner, and consequently inhabiting the E. coli growth. While this was a preliminary study, our results showed that this nanoparticle may have a significant impact on genomic activities.

  17. Upper bounds on superpartner masses from upper bounds on the Higgs boson mass.

    Science.gov (United States)

    Cabrera, M E; Casas, J A; Delgado, A

    2012-01-13

    The LHC is putting bounds on the Higgs boson mass. In this Letter we use those bounds to constrain the minimal supersymmetric standard model (MSSM) parameter space using the fact that, in supersymmetry, the Higgs mass is a function of the masses of sparticles, and therefore an upper bound on the Higgs mass translates into an upper bound for the masses for superpartners. We show that, although current bounds do not constrain the MSSM parameter space from above, once the Higgs mass bound improves big regions of this parameter space will be excluded, putting upper bounds on supersymmetry (SUSY) masses. On the other hand, for the case of split-SUSY we show that, for moderate or large tanβ, the present bounds on the Higgs mass imply that the common mass for scalars cannot be greater than 10(11)  GeV. We show how these bounds will evolve as LHC continues to improve the limits on the Higgs mass.

  18. Bounds on poloidal kinetic energy in plane layer convection

    Science.gov (United States)

    Tilgner, A.

    2017-12-01

    A numerical method is presented that conveniently computes upper bounds on heat transport and poloidal energy in plane layer convection for infinite and finite Prandtl numbers. The bounds obtained for the heat transport coincide with earlier results. These bounds imply upper bounds for the poloidal energy, which follow directly from the definitions of dissipation and energy. The same constraints used for computing upper bounds on the heat transport lead to improved bounds for the poloidal energy.

  19. Bounds for nonlinear composites via iterated homogenization

    Science.gov (United States)

    Ponte Castañeda, P.

    2012-09-01

    Improved estimates of the Hashin-Shtrikman-Willis type are generated for the class of nonlinear composites consisting of two well-ordered, isotropic phases distributed randomly with prescribed two-point correlations, as determined by the H-measure of the microstructure. For this purpose, a novel strategy for generating bounds has been developed utilizing iterated homogenization. The general idea is to make use of bounds that may be available for composite materials in the limit when the concentration of one of the phases (say phase 1) is small. It then follows from the theory of iterated homogenization that it is possible, under certain conditions, to obtain bounds for more general values of the concentration, by gradually adding small amounts of phase 1 in incremental fashion, and sequentially using the available dilute-concentration estimate, up to the final (finite) value of the concentration (of phase 1). Such an approach can also be useful when available bounds are expected to be tighter for certain ranges of the phase volume fractions. This is the case, for example, for the "linear comparison" bounds for porous viscoplastic materials, which are known to be comparatively tighter for large values of the porosity. In this case, the new bounds obtained by the above-mentioned "iterated" procedure can be shown to be much improved relative to the earlier "linear comparison" bounds, especially at low values of the porosity and high triaxialities. Consistent with the way in which they have been derived, the new estimates are, strictly, bounds only for the class of multi-scale, nonlinear composites consisting of two well-ordered, isotropic phases that are distributed with prescribed H-measure at each stage in the incremental process. However, given the facts that the H-measure of the sequential microstructures is conserved (so that the final microstructures can be shown to have the same H-measure), and that H-measures are insensitive to length scales, it is conjectured

  20. Thermalization Time Bounds for Pauli Stabilizer Hamiltonians

    Science.gov (United States)

    Temme, Kristan

    2017-03-01

    We prove a general lower bound to the spectral gap of the Davies generator for Hamiltonians that can be written as the sum of commuting Pauli operators. These Hamiltonians, defined on the Hilbert space of N-qubits, serve as one of the most frequently considered candidates for a self-correcting quantum memory. A spectral gap bound on the Davies generator establishes an upper limit on the life time of such a quantum memory and can be used to estimate the time until the system relaxes to thermal equilibrium when brought into contact with a thermal heat bath. The bound can be shown to behave as {λ ≥ O(N^{-1} exp(-2β overline{ɛ}))}, where {overline{ɛ}} is a generalization of the well known energy barrier for logical operators. Particularly in the low temperature regime we expect this bound to provide the correct asymptotic scaling of the gap with the system size up to a factor of N -1. Furthermore, we discuss conditions and provide scenarios where this factor can be removed and a constant lower bound can be proven.

  1. Universal bounds in even-spin CFTs

    Energy Technology Data Exchange (ETDEWEB)

    Qualls, Joshua D. [Department of Physics, National Taiwan University,Taipei, Taiwan (China)

    2015-12-01

    We prove using invariance under the modular S− and ST−transformations that every unitary two-dimensional conformal field theory (CFT) having only even-spin primary operators (with no extended chiral algebra and with right- and left-central charges c,c̃>1) contains a primary operator with dimension Δ{sub 1} satisfying 0<Δ{sub 1}<((c+c̃)/24)+0.09280…. After deriving both analytical and numerical bounds, we discuss how to extend our methods to bound higher conformal dimensions before deriving lower and upper bounds on the number of primary operators in a given energy range. Using the AdS{sub 3}/CFT{sub 2} dictionary, the bound on Δ{sub 1} proves the lightest massive excitation in appropriate theories of 3D matter and gravity with cosmological constant Λ<0 can be no heavier than 1/8G{sub N}+O(√(−Λ)); the bounds on the number of operators are related via AdS/CFT to the entropy of states in the dual gravitational theory. In the flat-space approximation, the limiting mass is exactly that of the lightest BTZ black hole.

  2. Nanoparticle size and production efficiency are affected by the presence of fatty acids during albumin nanoparticle fabrication.

    Directory of Open Access Journals (Sweden)

    Christian C Luebbert

    Full Text Available We have previously identified extensive glycation, bound fatty acids and increased quantities of protein aggregates in commercially available recombinant HSA (rHSA expressed in Oryza sativa (Asian rice (OsrHSA when compared to rHSA from other expression systems. We propose these differences may alter some attributes of nanoparticles fabricated with OsrHSA, as studies have associated greater quantities of aggregates with increased nanoparticle diameters. To determine if this is the case, nanoparticles were fabricated with OsrHSA from various suppliers using ethanol desolvation and subsequent glutaraldehyde cross-linking. All nanoparticles fabricated with OsrHSA showed larger diameters of approximately 20 to 90nm than particles fabricated with either defatted bovine serum albumin (DF-BSA (100.9 ± 2.8nm or human plasma albumin (pHSA (112.0 ± 4.0nm. It was hypothesized that the larger nanoparticle diameters were due to the presence of bound fatty acids and this was confirmed through defatting OsrHSA prior to particle fabrication which yielded particles with diameters similar to those fabricated with pHSA. For additional conformation, DF-BSA was incubated with dodecanoic acid prior to desolvation yielding particles with significantly larger diameters. Further studies showed the increased nanoparticle diameters were due to the bound fatty acids modulating electrostatic interactions between albumin nanoparticles during the desolvation and not changes in protein structure, stability or generation of additional albumin oligomers. Finally the presence of dodecanoic acid was shown to improve doxorubicin loading efficiency onto preformed albumin nanoparticles.

  3. Yukawa Bound States and Their LHC Phenomenology

    Directory of Open Access Journals (Sweden)

    Enkhbat Tsedenbaljir

    2013-01-01

    Full Text Available We present the current status on the possible bound states of extra generation quarks. These include phenomenology and search strategy at the LHC. If chiral fourth-generation quarks do exist their strong Yukawa couplings, implied by current experimental lower bound on their masses, may lead to formation of bound states. Due to nearly degenerate 4G masses suggested by Precision Electroweak Test one can employ “heavy isospin” symmetry to classify possible spectrum. Among these states, the color-octet isosinglet vector ω 8 is the easiest to be produced at the LHC. The discovery potential and corresponding decay channels are covered in this paper. With possible light Higgs at ~125 GeV two-Higgs doublet version is briefly discussed.

  4. Bounded Gaps between Products of Special Primes

    Directory of Open Access Journals (Sweden)

    Ping Ngai Chung

    2014-03-01

    Full Text Available In their breakthrough paper in 2006, Goldston, Graham, Pintz and Yıldırım proved several results about bounded gaps between products of two distinct primes. Frank Thorne expanded on this result, proving bounded gaps in the set of square-free numbers with r prime factors for any r ≥ 2, all of which are in a given set of primes. His results yield applications to the divisibility of class numbers and the triviality of ranks of elliptic curves. In this paper, we relax the condition on the number of prime factors and prove an analogous result using a modified approach. We then revisit Thorne’s applications and give a better bound in each case.

  5. Braneworld black holes and entropy bounds

    Directory of Open Access Journals (Sweden)

    Y. Heydarzade

    2018-01-01

    Full Text Available The Bousso's D-bound entropy for the various possible black hole solutions on a 4-dimensional brane is checked. It is found that the D-bound entropy here is apparently different from that of obtained for the 4-dimensional black hole solutions. This difference is interpreted as the extra loss of information, associated to the extra dimension, when an extra-dimensional black hole is moved outward the observer's cosmological horizon. Also, it is discussed that N-bound entropy is hold for the possible solutions here. Finally, by adopting the recent Bohr-like approach to black hole quantum physics for the excited black holes, the obtained results are written also in terms of the black hole excited states.

  6. Energy conditions bounds and supernovae data

    International Nuclear Information System (INIS)

    Lima, M.P.; Vitenti, S.D.P.; Reboucas, M.J.

    2008-01-01

    The energy conditions play an important role in the description of some important properties of the Universe, including the current accelerating expansion phase and the possible recent phase of super-acceleration. In a recent work we have provided a detailed study of the energy conditions for the recent past by deriving bounds from energy conditions and by making the confrontation of the bounds with supernovae data. Here, we extend and update these results in two different ways. First, by carrying out a new statistical analysis for q(z) estimates needed for the confrontation between the bounds and supernovae data. Second, by providing a new picture of the energy conditions fulfillment and violation in the light of the recently compiled Union set of 307 type Ia supernovae and by using two different statistical approaches

  7. Bound water in Kevlar 49 fibers

    International Nuclear Information System (INIS)

    Garza, R.G.; Pruneda, C.O.; Morgan, R.J.

    1981-01-01

    From elemental analyses, thermogravimetric-mass spectroscopy studies and re-evaluation of previous water diffusion studies in Kevlar 49 fibers it is concluded that these fibers can contain two types of sorbed moisture. The fibers can absorb up to approx. 6 wt % loosely bound water with an activation energy for outgassing by desorption of 6 kcal/mole. This loosely bound water is a direct result of the presence of Na 2 SO 4 impurities and the perturbations they induce on the packing of the rod-like poly (p-phenylene terephthalamide) macromolecules. Kevlar 49 fibers also inherently contain up to 30 wt % additional water which is tightly bound within the crystal lattice. This water exhibits an activation energy for outgassing by diffusion of approx. 40 kcal/mole and is only evolved from the fiber in significant quantities at t > 350 0 C over a period of hours

  8. Cosmological implications of Dark Matter bound states

    Energy Technology Data Exchange (ETDEWEB)

    Mitridate, Andrea [Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126, Pisa (Italy); Redi, Michele; Smirnov, Juri [INFN, Sezione di Firenze, and Dipartimento di Fisica e Astronomia, Università di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino (Italy); Strumia, Alessandro, E-mail: andrea.mitridate@gmail.com, E-mail: michele.redi@fi.infn.it, E-mail: juri.smirnov@mpi-hd.mpg.de, E-mail: alessandro.strumia@cern.ch [Dipartimento di Fisica dell' Università di Pisa and INFN, Pisa (Italy)

    2017-05-01

    We present generic formulæ for computing how Sommerfeld corrections together with bound-state formation affects the thermal abundance of Dark Matter with non-abelian gauge interactions. We consider DM as a fermion 3plet (wino) or 5plet under SU(2) {sub L} . In the latter case bound states raise to 11.5 TeV the DM mass required to reproduce the cosmological DM abundance and give indirect detection signals such as (for this mass) a dominant γ-line around 70 GeV. Furthermore, we consider DM co-annihilating with a colored particle, such as a squark or a gluino, finding that bound state effects are especially relevant in the latter case.

  9. Determination of Non-Transferrin Bound Iron, Transferrin Bound Iron, Drug Bound Iron and Total Iron in Serum in a Rats after IV Administration of Sodium Ferric Gluconate Complex by Simple Ultrafiltration Inductively Coupled Plasma Mass Spectrometric Detection

    Directory of Open Access Journals (Sweden)

    Murali K. Matta

    2018-02-01

    Full Text Available A rapid, sensitive and specific ultrafiltration inductively-coupled plasma mass spectrometry method was developed and validated for the quantification of non-transferrin bound iron (NTBI, transferrin bound iron (TBI, drug bound iron (DI and total iron (TI in the same rat serum sample after intravenous (IV administration of iron gluconate nanoparticles in sucrose solution (Ferrlecit®. Ultrafiltration with a 30 kDa molecular cut-off filter was used for sample cleanup. Different elution solvents were used to separate each form of iron from sample serum. Isolated fractions were subjected to inductively-coupled mass spectrometric analysis after microwave digestion in 4% nitric acid. The reproducibility of the method was evaluated by precision and accuracy. The calibration curve demonstrated linearity from 5–500 ng/mL with a regression (r2 of more than 0.998. This method was effectively implemented to quantify rat pharmacokinetic study samples after intravenous administration of Ferrlecit®. The method was successfully applied to a pharmacokinetic (PK study of Ferrlecit in rats. The colloidal iron followed first order kinetics with half-life of 2.2 h and reached background or pre-dose levels after 12 h post-dosing. The drug shown a clearance of 0.31 mL/min/kg and volume of distribution of 0.05 L/kg. 19.4 ± 2.4 mL/h/kg.

  10. Comparison of Lasserre's Measure-based Bounds for Polynomial Optimization to Bounds Obtained by Simulated Annealing

    NARCIS (Netherlands)

    de Klerk, Etienne; Laurent, Monique

    We consider the problem of minimizing a continuous function f over a compact set K. We compare the hierarchy of upper bounds proposed by Lasserre in [SIAM J. Optim. 21(3) (2011), pp. 864-885] to bounds that may be obtained from simulated annealing. We show that, when f is a polynomial and K a convex

  11. Career Development and Personal Functioning Differences between Work-Bound and Non-Work Bound Students

    Science.gov (United States)

    Creed, Peter A.; Patton, Wendy; Hood, Michelle

    2010-01-01

    We surveyed 506 Australian high school students on career development (exploration, planning, job-knowledge, decision-making, indecision), personal functioning (well-being, self-esteem, life satisfaction, school satisfaction) and control variables (parent education, school achievement), and tested differences among work-bound, college-bound and…

  12. A note on BPS vortex bound states

    Directory of Open Access Journals (Sweden)

    A. Alonso-Izquierdo

    2016-02-01

    Full Text Available In this note we investigate bound states, where scalar and vector bosons are trapped by BPS vortices in the Abelian Higgs model with a critical ratio of the couplings. A class of internal modes of fluctuation around cylindrically symmetric BPS vortices is characterized mathematically, analyzing the spectrum of the second-order fluctuation operator when the Higgs and vector boson masses are equal. A few of these bound states with low values of quantized magnetic flux are described fully, and their main properties are discussed.

  13. A note on BPS vortex bound states

    Energy Technology Data Exchange (ETDEWEB)

    Alonso-Izquierdo, A., E-mail: alonsoiz@usal.es [Departamento de Matematica Aplicada, Universidad de Salamanca (Spain); Garcia Fuertes, W., E-mail: wifredo@uniovi.es [Departamento de Fisica, Universidad de Oviedo (Spain); Mateos Guilarte, J., E-mail: guilarte@usal.es [Departamento de Fisica Fundamental, Universidad de Salamanca (Spain)

    2016-02-10

    In this note we investigate bound states, where scalar and vector bosons are trapped by BPS vortices in the Abelian Higgs model with a critical ratio of the couplings. A class of internal modes of fluctuation around cylindrically symmetric BPS vortices is characterized mathematically, analyzing the spectrum of the second-order fluctuation operator when the Higgs and vector boson masses are equal. A few of these bound states with low values of quantized magnetic flux are described fully, and their main properties are discussed.

  14. [Membrane-bound cytokine and feedforward regulation].

    Science.gov (United States)

    Wu, Ke-Fu; Zheng, Guo-Guang; Ma, Xiao-Tong; Song, Yu-Hua

    2013-10-01

    Feedback and feedforward widely exist in life system, both of them are the basic processes of control system. While the concept of feedback has been widely used in life science, feedforward regulation was systematically studied in neurophysiology, awaiting further evidence and mechanism in molecular biology and cell biology. The authors put forward a hypothesis about the feedforward regulation of membrane bound macrophage colony stimulation factor (mM-CSF) on the basis of their previous work. This hypothesis might provide a new direction for the study on the biological effects of mM-CSF on leukemia and solid tumors, and contribute to the study on other membrane bound cytokines.

  15. The covariant entropy bound in gravitational collapse

    International Nuclear Information System (INIS)

    Gao, Sijie; Lemos, Jose P. S.

    2004-01-01

    We study the covariant entropy bound in the context of gravitational collapse. First, we discuss critically the heuristic arguments advanced by Bousso. Then we solve the problem through an exact model: a Tolman-Bondi dust shell collapsing into a Schwarzschild black hole. After the collapse, a new black hole with a larger mass is formed. The horizon, L, of the old black hole then terminates at the singularity. We show that the entropy crossing L does not exceed a quarter of the area of the old horizon. Therefore, the covariant entropy bound is satisfied in this process. (author)

  16. Bound states in curved quantum waveguides

    International Nuclear Information System (INIS)

    Exner, P.; Seba, P.

    1987-01-01

    We study free quantum particle living on a curved planar strip Ω of a fixed width d with Dirichlet boundary conditions. It can serve as a model for electrons in thin films on a cylindrical-type substrate, or in a curved quantum wire. Assuming that the boundary of Ω is infinitely smooth and its curvature decays fast enough at infinity, we prove that a bound state with energy below the first transversal mode exists for all sufficiently small d. A lower bound on the critical width is obtained using the Birman-Schwinger technique. (orig.)

  17. Lower Bounds for External Memory Dictionaries

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Fagerberg, Rolf

    2003-01-01

    We study trade-offs between the update time and the query time for comparison based external memory dictionaries. The main contributions of this paper are two lower bound trade offs between the I/O complexity of member queries and insertions: If N < M insertions perform at most δ · N/B I/Os, then......We study trade-offs between the update time and the query time for comparison based external memory dictionaries. The main contributions of this paper are two lower bound trade offs between the I/O complexity of member queries and insertions: If N

  18. Finding Maximal Pairs with Bounded Gap

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Lyngsø, Rune B.; Pedersen, Christian N. S.

    1999-01-01

    . In this paper we present methods for finding all maximal pairs under various constraints on the gap. In a string of length n we can find all maximal pairs with gap in an upper and lower bounded interval in time O(n log n+z) where z is the number of reported pairs. If the upper bound is removed the time reduces...... to O(n+z). Since a tandem repeat is a pair where the gap is zero, our methods can be seen as a generalization of finding tandem repeats. The running time of our methods equals the running time of well known methods for finding tandem repeats....

  19. Bound constrained quadratic programming via piecewise

    DEFF Research Database (Denmark)

    Madsen, Kaj; Nielsen, Hans Bruun; Pinar, M. C.

    1999-01-01

    of a symmetric, positive definite matrix, and is solved by Newton iteration with line search. The paper describes the algorithm and its implementation including estimation of lambda/sub 1/ , how to get a good starting point for the iteration, and up- and downdating of Cholesky factorization. Results of extensive......We consider the strictly convex quadratic programming problem with bounded variables. A dual problem is derived using Lagrange duality. The dual problem is the minimization of an unconstrained, piecewise quadratic function. It involves a lower bound of lambda/sub 1/ , the smallest eigenvalue...

  20. Quantum Kolmogorov complexity and bounded quantum memory

    International Nuclear Information System (INIS)

    Miyadera, Takayuki

    2011-01-01

    The effect of bounded quantum memory in a primitive information protocol has been examined using the quantum Kolmogorov complexity as a measure of information. We employed a toy two-party protocol in which Bob, by using a bounded quantum memory and an unbounded classical memory, estimates a message that was encoded in qubits by Alice in one of the bases X or Z. Our theorem gave a nontrivial effect of the memory boundedness. In addition, a generalization of the uncertainty principle in the presence of quantum memory has been obtained.

  1. Models of bounded rationality under certainty

    NARCIS (Netherlands)

    Rasouli, S.; Timmermans, H.J.P.; Rasouli, S.; Timmermans, H.J.P.

    2015-01-01

    Purpose This chapter reviews models of decision-making and choice under conditions of certainty. It allows readers to position the contribution of the other chapters in this book in the historical development of the topic area. Theory Bounded rationality is defined in terms of a strategy to simplify

  2. Sobolev spaces on bounded symmetric domains

    Czech Academy of Sciences Publication Activity Database

    Engliš, Miroslav

    Roč. 60, č. 12 ( 2015 ), s. 1712-1726 ISSN 1747-6933 Institutional support: RVO:67985840 Keywords : bounded symmetric domain * Sobolev space * Bergman space Subject RIV: BA - General Mathematics Impact factor: 0.466, year: 2015 http://www.tandfonline.com/doi/abs/10.1080/17476933. 2015 .1043910

  3. Properties of Excitons Bound to Ionized Donors

    DEFF Research Database (Denmark)

    Skettrup, Torben; Suffczynski, M.; Gorzkowski, W.

    1971-01-01

    Binding energies, interparticle distances, oscillator strengths, and exchange corrections are calculated for the three-particle complex corresponding to an exciton bound to an ionized donor. The results are given as functions of the mass ratio of the electron and hole. Binding of the complex is o...

  4. Bogomol'nyi bounds for cosmic strings

    International Nuclear Information System (INIS)

    Comtet, A.; Gibbons, G.W.; Cambridge Univ.

    1987-09-01

    We establish Bogomol'nyi inequalities for the deficit angle of some cylindrically symmetric asymptotically local flat (CALF) spacetimes containing cosmic strings. These results prove the stability against arbitrary cylindrical deformations of those configurations which saturate the bound. Such configurations satisfy first order equations which can, in some cases, be solved exactly

  5. Bounding the bias of contrastive divergence learning

    DEFF Research Database (Denmark)

    Fischer, Anja; Igel, Christian

    2011-01-01

    Optimization based on k-step contrastive divergence (CD) has become a common way to train restricted Boltzmann machines (RBMs). The k-step CD is a biased estimator of the log-likelihood gradient relying on Gibbs sampling. We derive a new upper bound for this bias. Its magnitude depends on k...

  6. Bound States in the Mirror TBA

    NARCIS (Netherlands)

    Arutyunov, G.E.; Frolov, S.; van Tongeren, S.J.

    2012-01-01

    The spectrum of the light-cone AdS_5 \\times S^5 superstring contains states composed of particles with complex momenta including in particular those which turn into bound states in the decompactification limit. We propose the mirror TBA description for these states. We focus on a three-particle

  7. Harmonic maps of the bounded symmetric domains

    International Nuclear Information System (INIS)

    Xin, Y.L.

    1994-06-01

    A shrinking property of harmonic maps into R IV (2) is proved which is used to classify complete spacelike surfaces of the parallel mean curvature in R 4 2 with a reasonable condition on the Gauss image. Liouville-type theorems of harmonic maps from the higher dimensional bounded symmetric domains are also established. (author). 25 refs

  8. Scattering theory methods for bound state problems

    International Nuclear Information System (INIS)

    Raphael, R.B.; Tobocman, W.

    1978-01-01

    For the analysis of the properties of a bound state system one may use in place of the Schroedinger equation the Lippmann-Schwinger (LS) equation for the wave function or the LS equation for the reactance operator. Use of the LS equation for the reactance operator constrains the solution to have correct asymptotic behaviour, so this approach would appear to be desirable when the bound state wave function is to be used to calculate particle transfer form factors. The Schroedinger equation based N-level analysis of the s-wave bound states of a square well is compared to the ones based on the LS equation. It is found that the LS equation methods work better than the Schroedinger equation method. The method that uses the LS equation for the wave function gives the best results for the wave functions while the method that uses the LS equation for the reactance operator gives the best results for the binding energies. The accuracy of the reactance operator based method is remarkably insensitive to changes in the oscillator constant used for the harmonic oscillator function basis set. It is also remarkably insensitive to the number of nodes in the bound state wave function. (Auth.)

  9. Lower bounds on scintillation detector timing performance

    International Nuclear Information System (INIS)

    Clinthorne, N.H.; Rogers, W.L.; Hero, A.O. III.; Petrick, N.A.

    1990-01-01

    Fundamental method-independent limits on the timing performance of scintillation detectors are useful for identifying regimes in which either present timing methods are nearly optimal or where a considerable performance gain might be realized using better pulse processing techniques. Several types of lower bounds on mean-squared timing error (MSE) performance have been developed and applied to scintillation detectors. The simple Cramer-Rao (CR) bound can be useful in determining the limiting MSE for scintillators having a relatively high rate of photon problction such as BaF 2 and NaI(Tl); however, it tends to overestimate the achievalbe performance for scintillators with lower rates such as BGO. For this reason, alternative bounds have been developed using rate-distortion theory or by assuming that the conversion of energy to scintillation light must pass through excited states which have exponential lifetime densities. The bounds are functions of the mean scintillation pulse shape, the scintillation intensity, and photodetector characteristics; they are simple to evaluate and can be used to conveniently assess the limiting timing performance of scintillation detectors. (orig.)

  10. Efficiency gains, bounds, and risk in finance

    NARCIS (Netherlands)

    Sarisoy, Cisil

    2015-01-01

    This thesis consists of three chapters. The first chapter analyzes efficiency gains in the estimation of expected returns based on asset pricing models and examines the economic implications of such gains in portfolio allocation exercises. The second chapter provides nonparametric efficiency bounds

  11. Book Selection, Collection Development, and Bounded Rationality.

    Science.gov (United States)

    Schwartz, Charles A.

    1989-01-01

    Reviews previously proposed schemes of classical rationality in book selection, describes new approaches to rational choice behavior, and presents a model of book selection based on bounded rationality in a garbage can decision process. The role of tacit knowledge and symbolic content in the selection process are also discussed. (102 references)…

  12. Monotonicity and bounds on Bessel functions

    Directory of Open Access Journals (Sweden)

    Larry Landau

    2000-07-01

    Full Text Available survey my recent results on monotonicity with respect to order of general Bessel functions, which follow from a new identity and lead to best possible uniform bounds. Application may be made to the "spreading of the wave packet" for a free quantum particle on a lattice and to estimates for perturbative expansions.

  13. Collisional properties of weakly bound heteronuclear dimers

    NARCIS (Netherlands)

    Marcelis, B.; Kokkelmans, S.J.J.M.F.; Shlyapnikov, G.V.; Petrov, D.S.

    2008-01-01

    We consider collisional properties of weakly bound heteronuclear molecules (dimers) formed in a two-species mixture of atoms with a large mass difference. We focus on dimers containing light fermionic atoms as they manifest collisional stability due to an effective dimer-dimer repulsion originating

  14. Bounded Rationality of Generalized Abstract Fuzzy Economies

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2014-01-01

    Full Text Available By using a nonlinear scalarization technique, the bounded rationality model M for generalized abstract fuzzy economies in finite continuous spaces is established. Furthermore, by using the model M, some new theorems for structural stability and robustness to (λ,ϵ-equilibria of generalized abstract fuzzy economies are proved.

  15. Bounded Rationality in Individual Decision Making

    OpenAIRE

    Camerer, Colin F.

    1998-01-01

    The main objectives of this paper are: (i) To give a pithy, opinionated summary of what has been learned about bounded rationality in individual decision making from experiments in economics and psychology (drawing on my 1995 Handbook of Experimental Economics chapter); and (ii) mention some promising new directions for research which would be included if that chapter were written today.

  16. Differential plasma protein binding to metal oxide nanoparticles

    International Nuclear Information System (INIS)

    Deng, Zhou J; Mortimer, Gysell; Minchin, Rodney F; Schiller, Tara; Musumeci, Anthony; Martin, Darren

    2009-01-01

    Nanoparticles rapidly interact with the proteins present in biological fluids, such as blood. The proteins that are adsorbed onto the surface potentially dictate the biokinetics of the nanomaterials and their fate in vivo. Using nanoparticles with different sizes and surface characteristics, studies have reported the effects of physicochemical properties on the composition of adsorbed plasma proteins. However, to date, few studies have been conducted focusing on the nanoparticles that are commonly exposed to the general public, such as the metal oxides. Using previously established ultracentrifugation approaches, two-dimensional gel electrophoresis and mass spectrometry, the current study investigated the binding of human plasma proteins to commercially available titanium dioxide, silicon dioxide and zinc oxide nanoparticles. We found that, despite these particles having similar surface charges in buffer, they bound different plasma proteins. For TiO 2 , the shape of the nanoparticles was also an important determinant of protein binding. Agglomeration in water was observed for all of the nanoparticles and both TiO 2 and ZnO further agglomerated in biological media. This led to an increase in the amount and number of different proteins bound to these nanoparticles. Proteins with important biological functions were identified, including immunoglobulins, lipoproteins, acute-phase proteins and proteins involved in complement pathways and coagulation. These results provide important insights into which human plasma proteins bind to particular metal oxide nanoparticles. Because protein absorption to nanoparticles may determine their interaction with cells and tissues in vivo, understanding how and why plasma proteins are adsorbed to these particles may be important for understanding their biological responses.

  17. Sharp Bounds for Symmetric and Asymmetric Diophantine Approximation

    Institute of Scientific and Technical Information of China (English)

    Cornelis KRAAIKAMP; Ionica SMEETS

    2011-01-01

    In 2004,Tong found bounds for the approximation quality of a regular continued fraction convergent to a rational number,expressed in bounds for both the previous and next approximation.The authors sharpen his results with a geometric method and give both sharp upper and lower bounds.The asymptotic frequencies that these bounds occur are also calculated.

  18. Bounds on fluid permeability for viscous flow through porous media

    International Nuclear Information System (INIS)

    Berryman, J.G.

    1985-01-01

    General properties of variational bounds on Darcy's constant for slow viscous flow through porous media are studied. The bounds are also evaluated numerically for the penetrable sphere model. The bound of Doi depending on two-point correlations and the analytical bound of Weissberg and Prager give comparable results in the low density limit but the analytical bound is superior for higher densities. Prager's bound depending on three-point correlation functions is worse than the analytical bound at low densities but better (although comparable to it) at high densities. A procedure for methodically improving Prager's three point bound is presented. By introducing a Gaussian trial function, the three-point bound is improved by an order of magnitude for moderate values of porosity. The new bounds are comparable in magnitude to the Kozeny--Carman empirical relation for porous materials

  19. Upper bounds for reversible circuits based on Young subgroups

    DEFF Research Database (Denmark)

    Abdessaied, Nabila; Soeken, Mathias; Thomsen, Michael Kirkedal

    2014-01-01

    We present tighter upper bounds on the number of Toffoli gates needed in reversible circuits. Both multiple controlled Toffoli gates and mixed polarity Toffoli gates have been considered for this purpose. The calculation of the bounds is based on a synthesis approach based on Young subgroups...... that results in circuits using a more generalized gate library. Starting from an upper bound for this library we derive new bounds which improve the existing bound by around 77%....

  20. Synthesis and characterization of titania-based monodisperse fluorescent europium nanoparticles for biolabeling

    International Nuclear Information System (INIS)

    Tan Mingqian; Wang Guilan; Ye Zhiqiang; Yuan Jingli

    2006-01-01

    Inorganic-organic hybrid titania-based nanoparticles covalently bound to a fluorescent Eu 3+ chelate of 4,4'-bis(1'',1'',1'',2'',2'',3'',3''-heptafluoro-4'',6''-hexanedion-6''-yl) chlorosulfo-o-terphenyl (BHHCT-Eu 3+ ) were synthesized by a sol-gel technique. A conjugate of BHHCT with 3-[2-(2-aminoethylamino) ethylamino]propyl-trimethoxysilane (APTS) was used as a precursor for the nanoparticle preparation and monodisperse nanoparticles consisting of titania network and silica sub-network covalently bound to the Eu 3+ chelate were prepared by the copolymerization of APTS-BHHCT conjugate, titanium tetraisopropoxide (TTIP) and free APTS in EuCl 3 water-alcohol solution. The effects of reaction conditions on size and fluorescence lifetime of the nanoparticles were investigated. The characterizations by transmission electron microscopy and fluorometric methods indicate that the nanoparticles are near spherical and strongly fluorescent having a fluorescence quantum yield of 11.6% and a long fluorescence lifetime of ∼0.4 ms. The direct-introduced amino groups on the nanoparticle's surface by using free APTS in nanoparticle preparation facilitated the biolabeling process of the nanoparticles. The nanoparticle-labeled streptavidin (SA) was prepared and used in a sandwich-type time-resolved fluoroimmunoassay (TR-FIA) of human prostate-specific antigen (PSA) by using a 96-well microtiter plate as the solid phase carrier. The method gives a detection limit of 66 pg/ml for the PSA assay

  1. Analysis of SiO2 nanoparticles binding proteins in rat blood and brain homogenate

    Directory of Open Access Journals (Sweden)

    Shim KH

    2014-12-01

    Full Text Available Kyu Hwan Shim,1 John Hulme,1 Eun Ho Maeng,2 Meyoung-Kon Kim,3 Seong Soo A An1 1Department of Bionano Technology, Gachon Medical Research Institute, Gachon University, Sungnam-si, 2Department of Analysis, KTR, Kimpo, Gyeonggi-do, 3Department of Biochemistry and Molecular Biology, Korea University Medical School and College, Seoul, South Korea Abstract: A multitude of nanoparticles, such as titanium oxide (TiO2, zinc oxide, aluminum oxide, gold oxide, silver oxide, iron oxide, and silica oxide, are found in many chemical, cosmetic, pharmaceutical, and electronic products. Recently, SiO2 nanoparticles were shown to have an inert toxicity profile and no association with an irreversible toxicological change in animal models. Hence, exposure to SiO2 nanoparticles is on the increase. SiO2 nanoparticles are routinely used in numerous materials, from strengthening filler for concrete and other construction composites, to nontoxic platforms for biomedical application, such as drug delivery and theragnostics. On the other hand, recent in vitro experiments indicated that SiO2 nanoparticles were cytotoxic. Therefore, we investigated these nanoparticles to identify potentially toxic pathways by analyzing the adsorbed protein corona on the surface of SiO2 nanoparticles in the blood and brain of the rat. Four types of SiO2 nanoparticles were chosen for investigation, and the protein corona of each type was analyzed using liquid chromatography-tandem mass spectrometry technology. In total, 115 and 48 plasma proteins from the rat were identified as being bound to negatively charged 20 nm and 100 nm SiO2 nanoparticles, respectively, and 50 and 36 proteins were found for 20 nm and 100 nm arginine-coated SiO2 nanoparticles, respectively. Higher numbers of proteins were adsorbed onto the 20 nm sized SiO2 nanoparticles than onto the 100 nm sized nanoparticles regardless of charge. When proteins were compared between the two charges, higher numbers of proteins were

  2. Optima and bounds for irreversible thermodynamic processes

    International Nuclear Information System (INIS)

    Hoffmann, K.H.

    1990-01-01

    In this paper bounds and optima for irreversible thermodynamic processes and their application in different fields are discussed. The tools of finite time thermodynamics are presented and especially optimal control theory is introduced. These methods are applied to heat engines, including models of the Diesel engine and a light-driven engine. Further bounds for irreversible processes are introduced, discussing work deficiency and its relation to thermodynamic length. Moreover the problem of dissipation in systems composed of several subsystems is studied. Finally, the methods of finite time thermodynamics are applied to thermodynamic processes described on a more microscopic level. The process used as an example is simulated annealing. It is shown how optimal control theory is applied to find the optimal cooling schedule for this important stochastic optimization method

  3. Bounded excursion stable gravastars and black holes

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, P [Instituto de Fisica, Universidade Federal Fluminense, Avenida Litoranea, s/n, Boa Viagem 24210-340, Niteroi, RJ (Brazil); Miguelote, A Y; Chan, R [Coordenacao de Astronomia e Astrofisica, Observatorio Nacional, Rua General Jose Cristino, 77, Sao Cristovao 20921-400, Rio de Janeiro, RJ (Brazil); Da Silva, M F; Wang, Anzhong [Departamento de Fisica Teorica, Instituto de Fisica, Universidade do Estado do Rio de Janeiro, Rua Sao Francisco Xavier 524, Maracana 20550-900, Rio de Janeiro-RJ (Brazil); Santos, N O, E-mail: pedrosennarocha@gmail.com, E-mail: yasuda@on.br, E-mail: chan@on.br, E-mail: mfasnic@gmail.com, E-mail: N.O.Santos@qmul.ac.uk, E-mail: anzhong_wang@baylor.edu [LERMA/CNRS-FRE 2460, Universite Pierre et Marie Curie, ERGA, Boite 142, 4 Place Jussieu, 75005 Paris Cedex 05 (France)

    2008-06-15

    Dynamical models of prototype gravastars were constructed in order to study their stability. The models are the Visser-Wiltshire three-layer gravastars, in which an infinitely thin spherical shell of stiff fluid divides the whole spacetime into two regions, where the internal region is de Sitter, and the external one is Schwarzschild. It is found that in some cases the models represent the 'bounded excursion' stable gravastars, where the thin shell is oscillating between two finite radii, while in other cases they collapse until the formation of black holes occurs. In the phase space, the region for the 'bounded excursion' gravastars is very small in comparison to that of black holes, but not empty. Therefore, although the possibility of the existence of gravastars cannot be excluded from such dynamical models, our results indicate that, even if gravastars do indeed exist, that does not exclude the possibility of the existence of black holes.

  4. Optimal Bounds in Parametric LTL Games

    Directory of Open Access Journals (Sweden)

    Martin Zimmermann

    2011-06-01

    Full Text Available We consider graph games of infinite duration with winning conditions in parameterized linear temporal logic, where the temporal operators are equipped with variables for time bounds. In model checking such specifications were introduced as "PLTL" by Alur et al. and (in a different version called "PROMPT-LTL" by Kupferman et al.. We present an algorithm to determine optimal variable valuations that allow a player to win a game. Furthermore, we show how to determine whether a player wins a game with respect to some, infinitely many, or all valuations. All our algorithms run in doubly-exponential time; so, adding bounded temporal operators does not increase the complexity compared to solving plain LTL games.

  5. Asymptotic Sharpness of Bounds on Hypertrees

    Directory of Open Access Journals (Sweden)

    Lin Yi

    2017-08-01

    Full Text Available The hypertree can be defined in many different ways. Katona and Szabó introduced a new, natural definition of hypertrees in uniform hypergraphs and investigated bounds on the number of edges of the hypertrees. They showed that a k-uniform hypertree on n vertices has at most (nk−1$\\left( {\\matrix{n \\cr {k - 1} } } \\right$ edges and they conjectured that the upper bound is asymptotically sharp. Recently, Szabó verified that the conjecture holds by recursively constructing an infinite sequence of k-uniform hypertrees and making complicated analyses for it. In this note we give a short proof of the conjecture by directly constructing a sequence of k-uniform k-hypertrees.

  6. A holographic bound for D3-brane

    Energy Technology Data Exchange (ETDEWEB)

    Momeni, Davood; Myrzakul, Aizhan; Myrzakulov, Ratbay [Eurasian National University, Eurasian International Center for Theoretical Physics, Astana (Kazakhstan); Eurasian National University, Department of General Theoretical Physics, Astana (Kazakhstan); Faizal, Mir [University of British Columbia-Okanagan, Irving K. Barber School of Arts and Sciences, Kelowna, BC (Canada); University of Lethbridge, Department of Physics and Astronomy, Lethbridge, AB (Canada); Bahamonde, Sebastian [University College London, Department of Mathematics, London (United Kingdom)

    2017-06-15

    In this paper, we will regularize the holographic entanglement entropy, holographic complexity and fidelity susceptibility for a configuration of D3-branes. We will also study the regularization of the holographic complexity from the action for a configuration of D3-branes. It will be demonstrated that for a spherical shell of D3-branes the regularized holographic complexity is always greater than or equal to the regularized fidelity susceptibility. Furthermore, we will also demonstrate that the regularized holographic complexity is related to the regularized holographic entanglement entropy for this system. Thus, we will obtain a holographic bound involving regularized holographic complexity, regularized holographic entanglement entropy and regularized fidelity susceptibility of a configuration of D3-brane. We will also discuss a bound for regularized holographic complexity from action, for a D3-brane configuration. (orig.)

  7. Bound states in weakly disordered spin ladders

    Energy Technology Data Exchange (ETDEWEB)

    Arlego, M. [Departamento de Fisica, Universidad Nacional de La Plata, CC 67 (1900) La Plata (Argentina)]. E-mail: arlego@venus.fisica.unlp.edu.ar; Brenig, W. [Institut fuer Theoretische Physik, Technische Universitaet Braunschweig (Germany); Cabra, D.C. [Laboratoire de Physique Theorique, Universite Louis Pasteur Strasbourg (France); Heidrich-Meisner, F. [Institut fuer Theoretische Physik, Technische Universitaet Braunschweig (Germany); Honecker, A. [Institut fuer Theoretische Physik, Technische Universitaet Braunschweig (Germany); Rossini, G. [Departamento de Fisica, Universidad Nacional de La Plata, CC 67 (1900) La Plata (Argentina)

    2005-04-30

    We study the appearance of bound states in the spin gap of spin-12 ladders induced by weak bond disorder. Starting from the strong-coupling limit, i.e., the limit of weakly coupled dimers, we perform a projection on the single-triplet subspace and derive the position of bound states for the single impurity problem of one modified coupling as well as for small impurity clusters. The case of a finite concentration of impurities is treated with the coherent-potential approximation (CPA) in the strong-coupling limit and compared with numerical results. Further, we analyze the details in the structure of the density of states and relate their origin to the influence of impurity clusters.

  8. Entanglement detection with bounded reference frames

    International Nuclear Information System (INIS)

    Costa, Fabio; Brukner, Caslav; Harrigan, Nicholas; Rudolph, Terry

    2009-01-01

    Quantum experiments usually assume the existence of perfect, classical reference frames (RFs), which allow for the specification of measurement settings (e.g. orientation of the Stern-Gerlach magnet in spin measurements) with arbitrary precision. If the RFs are 'bounded' (i.e. quantum systems themselves, having a finite number of degrees of freedom), only limited precision can be attained. Using spin coherent states as bounded RFs, we have found the minimum size needed for them to violate local realism for entangled spin systems. For composite systems of spin 1/2 particles, RFs of very small size are sufficient for the violation; however, to see this violation for macroscopic entangled spins, the size of the RF must be at least quadratically larger than that of the spins. The unavailability of such RFs gives a possible explanation for the non-observance of violation of local realism in everyday experience.

  9. A proof of the conformal collider bounds

    Energy Technology Data Exchange (ETDEWEB)

    Hofman, Diego M. [Institute for Theoretical Physics, University of Amsterdam, Science Park 904, Postbus 94485, 1090 GL, Amsterdam (Netherlands); Li, Daliang [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Meltzer, David [Department of Physics, Yale University, New Haven, CT 06511 (United States); Poland, David [Department of Physics, Yale University, New Haven, CT 06511 (United States); School of Natural Sciences, Institute for Advanced Study, Princeton, NJ 08540 (United States); Rejon-Barrera, Fernando [Institute for Theoretical Physics, University of Amsterdam, Science Park 904, Postbus 94485, 1090 GL, Amsterdam (Netherlands)

    2016-06-20

    In this paper, we prove that the “conformal collider bounds” originally proposed in http://dx.doi.org/10.1088/1126-6708/2008/05/012 hold for any unitary parity-preserving conformal field theory (CFT) with a unique stress tensor in dimensions d≥3. In particular this implies that the ratio of central charges for a unitary 4d CFT lies in the interval (31/18)≥(a/c)≥(1/3). For superconformal theories this is further reduced to (3/2)≥(a/c)≥(1/2). The proof relies only on CFT first principles — in particular, bootstrap methods — and thus constitutes the first complete field theory proof of these bounds. We further elaborate on similar bounds for non-conserved currents and relate them to results obtained recently from deep inelastic scattering.

  10. Efficiency bounds for nonequilibrium heat engines

    International Nuclear Information System (INIS)

    Mehta, Pankaj; Polkovnikov, Anatoli

    2013-01-01

    We analyze the efficiency of thermal engines (either quantum or classical) working with a single heat reservoir like an atmosphere. The engine first gets an energy intake, which can be done in an arbitrary nonequilibrium way e.g. combustion of fuel. Then the engine performs the work and returns to the initial state. We distinguish two general classes of engines where the working body first equilibrates within itself and then performs the work (ergodic engine) or when it performs the work before equilibrating (non-ergodic engine). We show that in both cases the second law of thermodynamics limits their efficiency. For ergodic engines we find a rigorous upper bound for the efficiency, which is strictly smaller than the equivalent Carnot efficiency. I.e. the Carnot efficiency can be never achieved in single reservoir heat engines. For non-ergodic engines the efficiency can be higher and can exceed the equilibrium Carnot bound. By extending the fundamental thermodynamic relation to nonequilibrium processes, we find a rigorous thermodynamic bound for the efficiency of both ergodic and non-ergodic engines and show that it is given by the relative entropy of the nonequilibrium and initial equilibrium distributions. These results suggest a new general strategy for designing more efficient engines. We illustrate our ideas by using simple examples. -- Highlights: ► Derived efficiency bounds for heat engines working with a single reservoir. ► Analyzed both ergodic and non-ergodic engines. ► Showed that non-ergodic engines can be more efficient. ► Extended fundamental thermodynamic relation to arbitrary nonequilibrium processes

  11. Recent advances in bound state quantum electrodynamics

    International Nuclear Information System (INIS)

    Brodsky, S.J.; Lepage, G.P.

    1977-06-01

    Recent developments are reviewed in four areas of computational quantum electrodynamics: a new relativistic two-body formalism equal in rigor to the Bethe-Salpeter formalism but with strong calculational advantages is discussed; recent work on the computation of the decay rate of bound systems (positronium in particular) is presented; limits on possible composite structure of leptons are discussed; a new multidimensional integration program ('VEGAS') suitable for higher order calculations is presented

  12. Bounding probabilistic safety assessment probabilities by reality

    International Nuclear Information System (INIS)

    Fragola, J.R.; Shooman, M.L.

    1991-01-01

    The investigation of the failure in systems where failure is a rare event makes the continual comparisons between the developed probabilities and empirical evidence difficult. The comparison of the predictions of rare event risk assessments with historical reality is essential to prevent probabilistic safety assessment (PSA) predictions from drifting into fantasy. One approach to performing such comparisons is to search out and assign probabilities to natural events which, while extremely rare, have a basis in the history of natural phenomena or human activities. For example the Segovian aqueduct and some of the Roman fortresses in Spain have existed for several millennia and in many cases show no physical signs of earthquake damage. This evidence could be used to bound the probability of earthquakes above a certain magnitude to less than 10 -3 per year. On the other hand, there is evidence that some repetitive actions can be performed with extremely low historical probabilities when operators are properly trained and motivated, and sufficient warning indicators are provided. The point is not that low probability estimates are impossible, but continual reassessment of the analysis assumptions, and a bounding of the analysis predictions by historical reality. This paper reviews the probabilistic predictions of PSA in this light, attempts to develop, in a general way, the limits which can be historically established and the consequent bounds that these limits place upon the predictions, and illustrates the methodology used in computing such limits. Further, the paper discusses the use of empirical evidence and the requirement for disciplined systematic approaches within the bounds of reality and the associated impact on PSA probabilistic estimates

  13. Multipartite secret key distillation and bound entanglement

    International Nuclear Information System (INIS)

    Augusiak, Remigiusz; Horodecki, Pawel

    2009-01-01

    Recently it has been shown that quantum cryptography beyond pure entanglement distillation is possible and a paradigm for the associated protocols has been established. Here we systematically generalize the whole paradigm to the multipartite scenario. We provide constructions of new classes of multipartite bound entangled states, i.e., those with underlying twisted Greenberger-Horne-Zeilinger (GHZ) structure and nonzero distillable cryptographic key. We quantitatively estimate the key from below with the help of the privacy squeezing technique.

  14. Closed form bound-state perturbation theory

    Directory of Open Access Journals (Sweden)

    Ollie J. Rose

    1980-01-01

    Full Text Available The perturbed Schrödinger eigenvalue problem for bound states is cast into integral form using Green's Functions. A systematic algorithm is developed and applied to the resulting equation giving rise to approximate solutions expressed as functions of the given perturbation parameter. As a by-product, convergence radii for the traditional Rayleigh-Schrödinger and Brillouin-Wigner perturbation theories emerge in a natural way.

  15. Exact BPS bound for noncommutative baby Skyrmions

    International Nuclear Information System (INIS)

    Domrin, Andrei; Lechtenfeld, Olaf; Linares, Román; Maceda, Marco

    2013-01-01

    The noncommutative baby Skyrme model is a Moyal deformation of the two-dimensional sigma model plus a Skyrme term, with a group-valued or Grassmannian target. Exact abelian solitonic solutions have been identified analytically in this model, with a singular commutative limit. Inside any given Grassmannian, we establish a BPS bound for the energy functional, which is saturated by these baby Skyrmions. This asserts their stability for unit charge, as we also test in second-order perturbation theory

  16. The organically bound tritium: an analyst vision

    International Nuclear Information System (INIS)

    Ansoborlo, E.; Baglan, N.

    2009-01-01

    The authors report the work of a work group on tritium analysis. They recall the different physical forms of tritium: gas (HT, hydrogen-tritium), water vapour (HTO or tritiated water) or methane (CH3T), but also in organic compounds (OBT, organically bound tritium) which are either exchangeable or non-exchangeable. They evoke measurement techniques and methods, notably to determine the tritium volume activity. They discuss the possibilities to analyse and distinguish exchangeable and non-exchangeable OBTs

  17. New approach to calculate bound state eigenvalues

    International Nuclear Information System (INIS)

    Gerck, E.; Gallas, J.A.C.

    1983-01-01

    A method of solving the radial Schrodinger equation for bound states is discussed. The method is based on a new piecewise representation of the second derivative operator on a set of functions that obey the boundary conditions. This representation is trivially diagonalised and leads to closed form expressions of the type E sub(n)=E(ab+b+c/n+...) for the eigenvalues. Examples are given for the power-law and logarithmic potentials. (Author) [pt

  18. A sorting network in bounded arithmetic

    Czech Academy of Sciences Publication Activity Database

    Jeřábek, Emil

    2011-01-01

    Roč. 162, č. 4 (2011), s. 341-355 ISSN 0168-0072 R&D Projects: GA AV ČR IAA1019401; GA MŠk(CZ) 1M0545 Institutional research plan: CEZ:AV0Z10190503 Keywords : bounded arithmetic * sorting network * proof complexity * monotone sequent calculus Subject RIV: BA - General Mathematics Impact factor: 0.450, year: 2011 http://www.sciencedirect.com/science/article/pii/S0168007210001272

  19. Heterogeneity, Bounded Rationality and Market Dysfunctionality

    OpenAIRE

    Xue-Zhong He; Lei Shi

    2008-01-01

    As the main building blocks of the modern finance theory, homogeneity and rational expectation have faced difficulty in explaining many market anomalies, stylized factors, and market inefficiency in empirical studies. As a result, heterogeneity and bounded rationality have been used as an alterative paradigm of asset price dynamics and this paradigm has been widely recognized recently in both academic and financial market practitioners. Within the framework of Chiarella, Dieci and He (2006a, ...

  20. Kinetic simulation on collisional bounded plasma

    International Nuclear Information System (INIS)

    Zhu, S.P.; Sato, Tetsuya; Tomita, Yukihiro; Hatori, Tadatsugu

    1998-01-01

    A self-consistent kinetic simulation model on collisional bounded plasma is presented. The electric field is given by solving Poisson equation and collisions among particles (including charged particles and neutral particles) are included. The excitation and ionization of neutral particle, and recombination are also contained in the present model. The formation of potential structure near a boundary for a discharge system was used as an application of this model. (author)

  1. Analysis of the organically bound tritium

    International Nuclear Information System (INIS)

    Baglan, N.; Alanic, G.

    2011-01-01

    In environmental samples, tritium is very often combined with the fraction of bulk water accumulated in the sample but also in the form of organically bound tritium. When the tritium is organically bound, 2 forms can coexist: the exchangeable fraction and the non-exchangeable fraction. The analysis of the different forms of tritium present in the sample is necessary to assess the sanitary hazards due to tritium. The total tritium is obtained from the analysis of the water released when the fresh sample is burnt while the organically bound tritium is obtained from the analysis of the water released when the dry extract of the sample is burnt. The measurement of the exchangeable fraction and the non-exchangeable fraction requires an additional stage of labile exchange. The exchangeable fraction is determined from the analysis of the water released during the labile exchange and the non-exchangeable fraction is determined from the water released during the combustion of the dry extract of the labile exchange

  2. Search for quasi bound η mesons

    International Nuclear Information System (INIS)

    Machner, H

    2015-01-01

    The search for a quasi bound η meson in atomic nuclei is reviewed. This tentative state is studied theoretically as well as experimentally. The theory starts from elastic η nucleon scattering which is derived from production data within some models. From this interaction the η nucleus interaction is derived. Model calculations predict binding energies and widths of the quasi bound state. Another method is to derive the η nucleus interaction from excitation functions of η production experiments. The s wave interaction is extracted from such data via final state interaction (FSI) theorem. We give the derivation of s wave amplitudes in partial wave expansion and in helicity amplitudes and their relation to observables. Different experiments extracting the FSI are discussed as are production experiments. So far only three experiments give evidence for the existence of the quasi bound state: a pion double charge exchange experiment, an effective mass measurement, and a transfer reaction at recoil free kinematics with observation of the decay of the state. (topical review)

  3. Lower bounds for the minimum distance of algebraic geometry codes

    DEFF Research Database (Denmark)

    Beelen, Peter

    , such as the Goppa bound, the Feng-Rao bound and the Kirfel-Pellikaan bound. I will finish my talk by giving several examples. Especially for two-point codes, the generalized order bound is fairly easy to compute. As an illustration, I will indicate how a lower bound can be obtained for the minimum distance of some...... description of these codes in terms of order domains has been found. In my talk I will indicate how one can use the ideas behind the order bound to obtain a lower bound for the minimum distance of any AG-code. After this I will compare this generalized order bound with other known lower bounds...

  4. Silver nanoparticles delivery system based on natural rubber latex membranes

    International Nuclear Information System (INIS)

    Guidelli, Éder José; Kinoshita, Angela; Ramos, Ana Paula; Baffa, Oswaldo

    2013-01-01

    The search for new materials for biomedical applications is extremely important. Here, we present results on the performance of a silver nanoparticles delivery system using natural rubber latex (NRL) as the polymeric matrix. Our aim was to obtain an optimized wound dressing by combining materials with potential healing action. The synthesis of silver nanoparticles and their characterization by UV–Vis spectroscopy, transmission electron microscopy, zeta potential, dynamic light scattering, and Fourier transform infrared spectroscopy (FTIR) are depicted. The NRL membranes are good matrix for silver nanoparticles and allow for their gradual release. The release of 30 nm silver nanoparticles by the NRL membranes depends on their mass percentage in NRL membranes. The total concentration of AgNP released by the NRL membranes was calculated. The AgNP attached to the cis-isoprene molecules in the NRL matrix remain attached to the membrane (∼0.1 % w/w). So, only the AgNP bound to the non-rubber molecules are released. FTIR spectra suggest that non-rubber molecules, like aminoacids and proteins, associated with the serum fraction of the NRL may be attached to the surfaces of the released nanoparticles, thereby increasing the release of such molecules. The released silver nanoparticles are sterically stabilized, more stable and well dispersed. Because the serum fraction of the NRL is responsible for the angiogenic properties of the matrix, the silver nanoparticles could increment the angiogenic properties of NRL. This biomaterial has desirable properties for the fabrication of a wound dressing with potential healing action, since it combines the angiogenic and antibacterial properties of the silver nanoparticles with the increased angiogenic properties of the NRL.Graphical AbstractThe AgNP attached to the cis-isoprene molecules remain in the NRL matrix and only the AgNP bound to the non-rubber molecules (NRL serum fraction) are released. The released AgNP are sterically

  5. Silver nanoparticles delivery system based on natural rubber latex membranes

    Energy Technology Data Exchange (ETDEWEB)

    Guidelli, Eder Jose, E-mail: ederguidelli@gmail.com [Universidade de Sao Paulo/FFCLRP-DF (Brazil); Kinoshita, Angela [Universidade do Sagrado Coracao (Brazil); Ramos, Ana Paula [Universidade de Sao Paulo/FFCLRP-DQ (Brazil); Baffa, Oswaldo [Universidade de Sao Paulo/FFCLRP-DF (Brazil)

    2013-04-15

    The search for new materials for biomedical applications is extremely important. Here, we present results on the performance of a silver nanoparticles delivery system using natural rubber latex (NRL) as the polymeric matrix. Our aim was to obtain an optimized wound dressing by combining materials with potential healing action. The synthesis of silver nanoparticles and their characterization by UV-Vis spectroscopy, transmission electron microscopy, zeta potential, dynamic light scattering, and Fourier transform infrared spectroscopy (FTIR) are depicted. The NRL membranes are good matrix for silver nanoparticles and allow for their gradual release. The release of 30 nm silver nanoparticles by the NRL membranes depends on their mass percentage in NRL membranes. The total concentration of AgNP released by the NRL membranes was calculated. The AgNP attached to the cis-isoprene molecules in the NRL matrix remain attached to the membrane ({approx}0.1 % w/w). So, only the AgNP bound to the non-rubber molecules are released. FTIR spectra suggest that non-rubber molecules, like aminoacids and proteins, associated with the serum fraction of the NRL may be attached to the surfaces of the released nanoparticles, thereby increasing the release of such molecules. The released silver nanoparticles are sterically stabilized, more stable and well dispersed. Because the serum fraction of the NRL is responsible for the angiogenic properties of the matrix, the silver nanoparticles could increment the angiogenic properties of NRL. This biomaterial has desirable properties for the fabrication of a wound dressing with potential healing action, since it combines the angiogenic and antibacterial properties of the silver nanoparticles with the increased angiogenic properties of the NRL.Graphical AbstractThe AgNP attached to the cis-isoprene molecules remain in the NRL matrix and only the AgNP bound to the non-rubber molecules (NRL serum fraction) are released. The released AgNP are

  6. Two-dimensional gold nanoparticle arrays. A platform for molecular optoelectronics

    Energy Technology Data Exchange (ETDEWEB)

    Mangold, Markus Andreas

    2011-11-15

    In my research, I study the optoelectronic properties of two-dimensional, hexagonal gold nanoparticle arrays formed by self-assembly. When the nanoparticle arrays are embedded in a matrix of alkane thiols, the photoresponse is dominated by a bolometric conductance increase. At room temperature, I observe a strong enhancement of the bolometric photoconductance when the surface plasmon resonance of the nanoparticles is excited. At cryogenic temperatures, the bolometric conductance enhancement leads to a redistribution of the potential landscape which dominates the optoelectronic response of the nanoparticle arrays. When optically active oligo(phenylene vinylene) (OPV) molecules are covalently bound to the nanoparticles, an increased photoconductance due to the resonant excitation of the OPV is observed. The results suggest that the charge carriers, which are resonantly excited in the OPV molecules, directly contribute to the current flow through the nanoparticle arrays. Thus, the conductance of OPV in its excited state is measured in the presented experiments. (orig.)

  7. Highly stable, protein capped gold nanoparticles as effective drug delivery vehicles for amino-glycosidic antibiotics

    International Nuclear Information System (INIS)

    Rastogi, Lori; Kora, Aruna Jyothi; Arunachalam, J.

    2012-01-01

    A method for the production of highly stable gold nanoparticles (Au NP) was optimized using sodium borohydride as reducing agent and bovine serum albumin as capping agent. The synthesized nanoparticles were characterized using UV–visible spectroscopy, transmission electron microscopy, X‐ray diffraction (XRD) and dynamic light scattering techniques. The formation of gold nanoparticles was confirmed from the appearance of pink colour and an absorption maximum at 532 nm. These protein capped nanoparticles exhibited excellent stability towards pH modification and electrolyte addition. The produced nanoparticles were found to be spherical in shape, nearly monodispersed and with an average particle size of 7.8 ± 1.7 nm. Crystalline nature of the nanoparticles in face centered cubic structure is confirmed from the selected‐area electron diffraction and XRD patterns. The nanoparticles were functionalized with various amino-glycosidic antibiotics for utilizing them as drug delivery vehicles. Using Fourier transform infrared spectroscopy, the possible functional groups of antibiotics bound to the nanoparticle surface have been examined. These drug loaded nanoparticle solutions were tested for their antibacterial activity against Gram-negative and Gram-positive bacterial strains, by well diffusion assay. The antibiotic conjugated Au NP exhibited enhanced antibacterial activity, compared to pure antibiotic at the same concentration. Being protein capped and highly stable, these gold nanoparticles can act as effective carriers for drugs and might have considerable applications in the field of infection prevention and therapeutics. - Highlights: ► Method for NaBH 4 reduced and BSA capped gold nanoparticle was standardized. ► Nanoparticles were spherical and nearly monodispersed with a size of 7.8 nm. ► Nanoparticles are extremely stable towards pH modification and electrolyte addition. ► Antibiotic conjugated nanoparticles exhibited enhanced antibacterial activity

  8. Glucan Particles for Macrophage Targeted Delivery of Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ernesto R. Soto

    2012-01-01

    Full Text Available Glucan particles (GPs are hollow, porous 2–4 μm microspheres derived from the cell walls of Baker's yeast (Saccharomyces cerevisiae. The 1,3-β-glucan outer shell provides for receptor-mediated uptake by phagocytic cells expressing β-glucan receptors. GPs have been used for macrophage-targeted delivery of soluble payloads (DNA, siRNA, protein, and small molecules encapsulated inside the hollow GPs via core polyplex and layer-by-layer (LbL synthetic strategies. In this communication, we report the incorporation of nanoparticles as cores inside GPs (GP-NP or electrostatically bound to the surface of chemically derivatized GPs (NP-GP. GP nanoparticle formulations benefit from the drug encapsulation properties of NPs and the macrophage-targeting properties of GPs. GP nanoparticle formulations were synthesized using fluorescent anionic polystyrene nanoparticles allowing visualization and quantitation of NP binding and encapsulation. Mesoporous silica nanoparticles (MSNs containing the chemotherapeutic doxorubicin (Dox were bound to cationic GPs. Dox-MSN-GPs efficiently delivered Dox into GP phagocytic cells resulting in enhanced Dox-mediated growth arrest.

  9. OPRA capacity bounds for selection diversity over generalized fading channels

    KAUST Repository

    Hanif, Muhammad Fainan; Yang, Hongchuan; Alouini, Mohamed-Slim

    2014-01-01

    , lower and upper bounds on OPRA capacity for selection diversity scheme are presented. These bounds hold for variety of fading channels including log-normal and generalized Gamma distributed models and have very simple analytic expressions for easy

  10. Unexpected strong attraction in the presence of continuum bound state

    International Nuclear Information System (INIS)

    Delfino, A.; Frederico, T.

    1992-06-01

    The result of few-particle ground-state calculation employing a two-particle non-local potential supporting a continuum bound state in addition to a negative-energy bound state has occasionally revealed unexpected large attraction in producing a very strongly bound ground state. In the presence of the continuum bound state the difference of phase shift between zero and infinite energies has an extra jump of φ as in the presence of an additional bound state. The wave function of the continuum bound state is identical with that of a strongly bound negative-energy state, which leads us to postulate a pseudo bound state in the two-particle system in order to explain the unexpected attraction. The role of the Pauli forbidden states is expected to be similar to these pseudo states. (author)

  11. Bounded Perturbation Regularization for Linear Least Squares Estimation

    KAUST Repository

    Ballal, Tarig; Suliman, Mohamed Abdalla Elhag; Al-Naffouri, Tareq Y.

    2017-01-01

    This paper addresses the problem of selecting the regularization parameter for linear least-squares estimation. We propose a new technique called bounded perturbation regularization (BPR). In the proposed BPR method, a perturbation with a bounded

  12. Bound values for Hall conductivity of heterogeneous medium under ...

    Indian Academy of Sciences (India)

    - ditions in inhomogeneous medium has been studied. It is shown that bound values for. Hall conductivity differ from bound values for metallic conductivity. This is due to the unusual character of current percolation under quantum Hall effect ...

  13. Bound states of Θ+ in nuclei

    International Nuclear Information System (INIS)

    Oset, E.; Cabrera, D.; Li, Q.B.; Magas, V.K.; Vicente Vacas, M.J.

    2005-01-01

    We study the binding energy and the width of the Θ + in nuclei, associated to the KN and KπN components. The first one leads to negligible contributions while the second one leads to a sizeable attraction, enough to bind the Θ + in nuclei. Pauli blocking and binding effects on the KN decay reduce considerably the Θ + decay width in nuclei and medium effects associated to the KπN component also lead to a very small width, as a consequence of which one finds separation between the bound levels considerably larger than the width of the states

  14. Fermionic bound states in distinct kinklike backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, Paraiba (Brazil); Mohammadi, A. [Universidade Federal de Campina Grande, Departamento de Fisica, Caixa Postal 10071, Campina Grande, Paraiba (Brazil)

    2017-04-15

    This work deals with fermions in the background of distinct localized structures in the two-dimensional spacetime. Although the structures have a similar topological character, which is responsible for the appearance of fractionally charged excitations, we want to investigate how the geometric deformations that appear in the localized structures contribute to the change in the physical properties of the fermionic bound states. We investigate the two-kink and compact kinklike backgrounds, and we consider two distinct boson-fermion interactions, one motivated by supersymmetry and the other described by the standard Yukawa coupling. (orig.)

  15. Quarks as quasiparticles of bound states

    International Nuclear Information System (INIS)

    Tyapkin, A.A.

    1977-01-01

    Interpretation of quarks as strongly bound subsystems of the baryon structure, being in various states with integer the quantum numbers Q and B, is considered. Three original quark states, distinguished by Q, B, and J, are unambiguously determined from the condition that the quarks have the corresponding fractional quantum numbers while the integer quantum numbers for the whole system are known. With this in view the new quantum number ''colour'' is interpreted as a quantity, specifying the appearance of the subsystems in various eigen-states. Basing on the generalized Sakata model, the self-consistency of change of the colour states in the three-quark system is explained

  16. Magnetic moment of a bound electron

    CERN Document Server

    Czarnecki, Andrzej; Mondejar, Jorge; Piclum, Jan H

    2010-01-01

    Theoretical predictions underlying determinations of the fine structure constant alpha and the electron-to-proton mass ratio m_e/m_p are reviewed, with the emphasis on the bound electron magnetic anomaly g-2. The theory of the interaction of hydrogen-like ions with a magnetic field is discussed. The status of efforts aimed at the determination of O(alpha (Z alpha)^5) and O(alpha^2 (Z alpha)^5) corrections to the g factor is presented. The reevaluation of analogous corrections to the Lamb shift and the hyperfine splitting is summarized.

  17. Andreev bound states. Some quasiclassical reflections

    International Nuclear Information System (INIS)

    Lin, Y.; Leggett, A. J.

    2014-01-01

    We discuss a very simple and essentially exactly solvable model problem which illustrates some nice features of Andreev bound states, namely, the trapping of a single Bogoliubov quasiparticle in a neutral s-wave BCS superfluid by a wide and shallow Zeeman trap. In the quasiclassical limit, the ground state is a doublet with a splitting which is proportional to the exponentially small amplitude for “normal” reflection by the edges of the trap. We comment briefly on a prima facie paradox concerning the continuity equation and conjecture a resolution to it

  18. Andreev bound states. Some quasiclassical reflections

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Y., E-mail: yiriolin@illinois.edu; Leggett, A. J. [University of Illinois at Urhana-Champaign, Dept. of Physics (United States)

    2014-12-15

    We discuss a very simple and essentially exactly solvable model problem which illustrates some nice features of Andreev bound states, namely, the trapping of a single Bogoliubov quasiparticle in a neutral s-wave BCS superfluid by a wide and shallow Zeeman trap. In the quasiclassical limit, the ground state is a doublet with a splitting which is proportional to the exponentially small amplitude for “normal” reflection by the edges of the trap. We comment briefly on a prima facie paradox concerning the continuity equation and conjecture a resolution to it.

  19. Uniformly bounded representations of the Lorentz groups

    International Nuclear Information System (INIS)

    Brega, A.O.

    1982-01-01

    For the Lorentz group G = SO/sub e/(n + 1, 1)(ngreater than or equal to 2) the author constructs a family of uniformly bounded representations by means of analytically continuing a certain normalization of the unitary principal series. The method the author uses relies on an analysis of various operators under a Mellin transform and extends earlier work of E.N. Wilson. In a series of papers Kunze and Stein initiated the theory of uniformly bounded representations of semisimple Lie groups; the starting point is the unitary principal series T(sigma,s) obtained in a certain subgroup M of G and a purely imaginary number s. From there Kunze and Stein constructed families of representations R(sigma,s) depending analytically on a parameter s in a domain D of C containing the imaginary axis which are unitarily equilvalent to T(sigma,s) for s contained in the set of imaginary numbers and whose operator norms are uniformly bounded for each s in D. In the case of the Lorentz groups SO/sub e/(n + 1, 1)(ngreater than or equal to2) and the trivial representation 1 of M, E.N. Wilson obtained such a family R(1,s) for the domain D = [s contained in the set of C: absolute value Re(s) Vertical Bar2]. For this domain D and for any representation sigma of M the author provides a family R(sigma,s) of uniformly bounded representations analytically continuing T(sigma,s), thereby generalizing Wilson's work. The author has also investigated certain symmetry properties of the representations R(sigma,s) under the action of the Weyl group. The trivial representation is Weyl group invariant and the family R(1,s) obtained by Wilson satisfies R(1,s) = R(1,-s) reflecting this. Obtained was the analogous result R(sigma,s) = R(sigma,-s) for some well known representations sigma that are Weyl group invariant. This involves the explicit computation of certain constants arising in the Fourier transforms of intertwining operators

  20. BOUND PERIODICAL HOLDINGS BATTELLE - NORTHWEST LIBRARY

    Energy Technology Data Exchange (ETDEWEB)

    None

    1967-05-01

    This report lists the bound periodicals in the Technical Library at the Pacific Northwest Laboratory, operated by Battelle Memorial Institute. It was prepared from a computer program and is arranged in two parts. Part one is an alphabetical list of journals by title; part two is an arrangement of the journals by subject. The list headings are self-explanatory, with the exception of the title code, which is necessary in the machine processing. The listing is complete through June, 1966 and updates an earlier publication issued in March, 1965.

  1. Total-variation regularization with bound constraints

    International Nuclear Information System (INIS)

    Chartrand, Rick; Wohlberg, Brendt

    2009-01-01

    We present a new algorithm for bound-constrained total-variation (TV) regularization that in comparison with its predecessors is simple, fast, and flexible. We use a splitting approach to decouple TV minimization from enforcing the constraints. Consequently, existing TV solvers can be employed with minimal alteration. This also makes the approach straightforward to generalize to any situation where TV can be applied. We consider deblurring of images with Gaussian or salt-and-pepper noise, as well as Abel inversion of radiographs with Poisson noise. We incorporate previous iterative reweighting algorithms to solve the TV portion.

  2. Bound Alternative Direction Optimization for Image Deblurring

    Directory of Open Access Journals (Sweden)

    Xiangrong Zeng

    2014-01-01

    the ℓp regularizer by a novel majorizer and then, based on a variable splitting, to reformulate the bound unconstrained problem into a constrained one, which is then addressed via an augmented Lagrangian method. The proposed algorithm actually combines the reweighted ℓ1 minimization method and the alternating direction method of multiples (ADMM such that it succeeds in extending the application of ADMM to ℓp minimization problems. The conducted experimental studies demonstrate the superiority of the proposed algorithm for the synthesis ℓp minimization over the state-of-the-art algorithms for the synthesis ℓ1 minimization on image deblurring.

  3. O3 Nanoparticles

    KAUST Repository

    Wang, Juan; Li, Yangyang; Deng, Lin; Wei, Nini; Weng, Yakui; Dong, Shuai; Qi, Dianpeng; Qiu, Jun; Chen, Xiaodong; Wu, Tao

    2016-01-01

    Ti2O3 nanoparticles with high performance of photothermal conversion are demonstrated for the first time. Benefiting from the nanosize and narrow-bandgap features, the Ti2O3 nanoparticles possess strong light absorption and nearly 100% internal

  4. Lower bound on inconclusive probability of unambiguous discrimination

    International Nuclear Information System (INIS)

    Feng Yuan; Zhang Shengyu; Duan Runyao; Ying Mingsheng

    2002-01-01

    We derive a lower bound on the inconclusive probability of unambiguous discrimination among n linearly independent quantum states by using the constraint of no signaling. It improves the bound presented in the paper of Zhang, Feng, Sun, and Ying [Phys. Rev. A 64, 062103 (2001)], and when the optimal discrimination can be reached, these two bounds coincide with each other. An alternative method of constructing an appropriate measurement to prove the lower bound is also presented

  5. Nanoparticle layer deposition for highly controlled multilayer formation based on high-coverage monolayers of nanoparticles

    International Nuclear Information System (INIS)

    Liu, Yue; Williams, Mackenzie G.; Miller, Timothy J.; Teplyakov, Andrew V.

    2016-01-01

    This paper establishes a strategy for chemical deposition of functionalized nanoparticles onto solid substrates in a layer-by-layer process based on self-limiting surface chemical reactions leading to complete monolayer formation within the multilayer system without any additional intermediate layers — nanoparticle layer deposition (NPLD). This approach is fundamentally different from previously established traditional layer-by-layer deposition techniques and is conceptually more similar to well-known atomic and molecular layer deposition processes. The NPLD approach uses efficient chemical functionalization of the solid substrate material and complementary functionalization of nanoparticles to produce a nearly 100% coverage of these nanoparticles with the use of “click chemistry”. Following this initial deposition, a second complete monolayer of nanoparticles is deposited using a copper-catalyzed “click reaction” with the azide-terminated silica nanoparticles of a different size. This layer-by-layer growth is demonstrated to produce stable covalently-bound multilayers of nearly perfect structure over macroscopic solid substrates. The formation of stable covalent bonds is confirmed spectroscopically and the stability of the multilayers produced is tested by sonication in a variety of common solvents. The 1-, 2- and 3-layer structures are interrogated by electron microscopy and atomic force microscopy and the thickness of the multilayers formed is fully consistent with that expected for highly efficient monolayer formation with each cycle of growth. This approach can be extended to include a variety of materials deposited in a predesigned sequence on different substrates with a highly conformal filling. - Highlights: • We investigate the formation of high-coverage monolayers of nanoparticles. • We use “click chemistry” to form these monolayers. • We form multiple layers based on the same strategy. • We confirm the formation of covalent bonds

  6. Thermodynamic Upper Bound on Broadband Light Coupling with Photonic Structures

    KAUST Repository

    Yu, Zongfu; Raman, Aaswath; Fan, Shanhui

    2012-01-01

    to an upper bound dictated by the second law of thermodynamics. Such bound limits how efficient light can be coupled to any photonic structure. As one example of application, we use this upper bound to derive the limit of light absorption in broadband solar

  7. Bounds on the capacity of constrained two-dimensional codes

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Justesen, Jørn

    2000-01-01

    Bounds on the capacity of constrained two-dimensional (2-D) codes are presented. The bounds of Calkin and Wilf apply to first-order symmetric constraints. The bounds are generalized in a weaker form to higher order and nonsymmetric constraints. Results are given for constraints specified by run-l...

  8. Bounded Rationality, Retaliation, and the Spread of Urban Violence

    Science.gov (United States)

    Jacobs, Bruce A.; Wright, Richard

    2010-01-01

    Drawing from in-depth interviews with 52 active street criminals, this article examines the grounded theoretic implications of bounded rationality for retaliatory street violence. The bounds on rationality that this article explores are anger, uncertainty, and time pressure. These bounds create imperfections in the retaliatory decision-making…

  9. Bounded dust-acoustic waves in a cylindrically bounded collisional dusty plasma with dust charge variation

    International Nuclear Information System (INIS)

    Wei Nanxia; Xue Jukui

    2006-01-01

    Taking into account the boundary, particle collisions, and dust charging effects, dust-acoustic waves in a uniform cylindrically bounded dusty plasma is investigated analytically, and the dispersion relation for the dust-acoustic wave is obtained. The effects of boundary, dust charge variation, particle collision, and dust size on the dust-acoustic wave are discussed in detail. Due to the bounded cylindrical boundary effects, the radial wave number is discrete, i.e., the spectrum is discrete. It is shown that the discrete spectrum, the adiabatic dust charge variation, dust grain size, and the particle collision have significant effects on the dust-acoustic wave

  10. O3 Nanoparticles

    KAUST Repository

    Wang, Juan

    2016-11-16

    Ti2O3 nanoparticles with high performance of photothermal conversion are demonstrated for the first time. Benefiting from the nanosize and narrow-bandgap features, the Ti2O3 nanoparticles possess strong light absorption and nearly 100% internal solar–thermal conversion efficiency. Furthermore, Ti2O3 nanoparticle-based thin film shows potential use in seawater desalination and purification.

  11. Analytic quantum bounds on Bell inequalities

    International Nuclear Information System (INIS)

    Filipp, S.; Svozil, K.

    2005-01-01

    Full text: Can realism be combined with the quantum world? An important tool to investigate in this question are Bell's inequalities and violations thereof - they represent a cornerstone of our present understanding of quantum mechanics and therefore the description of nature. Here we present a simple algebraic method to calculate violations for any measurement arrangements that are maximal in the sense that quantum mechanics does not allow a stronger violation. Having two or more polarization analyzers available and a source producing photon-pairs in arbitrary polarization states Bell-type inequalities tell us which probabilities for measuring the polarization in particular directions are viable in a deterministic theory. Quantum mechanics does not obey these rules, but yields a violation of these inequalities. The questions is to what extent the inequalities are violated. Making use of a min-max principle analytical expressions can be found for the 'fine structure' of the maximal violations of arbitrary Bell-like inequalities, i. e. the upper bound reachable by any state when the analyzers measure in given directions. Knowing these bounds is useful for experimental tests of the validity of quantum mechanics and can serve as a prerequisite to answer the even more pressing question, why no stronger violation has been observed until now. (author)

  12. Electromagnetic structure of a bound nucleon

    International Nuclear Information System (INIS)

    Nogami, Y.

    1977-01-01

    The effect of binding on the electromagnetic (e.m.) structure of a nucleon in a nucleus is examined by means of a model consisting of a single nucleon which is bound in a harmonic oscillator potential and also coupled to the pion field through the Chew-Low interaction. The 'two-pion contribution' to the e.m. structure is considered. This is the part which is probably most susceptible to the binding effect. By the binding effect it is meant the one which arises because the nucleon wave functions, in the intermediate state as well as in the initial and final states, are distorted by the potential in which the nucleon is bound. This may be compared to a similar correction to the impulse approximation for pion-nucleus scattering. Unlike the latter which is likely to be quite appreciable, the binding correction to the e.m. structure of the nucleon is found to be negligibly small. The so-called quenching effect due to the Pauli principle when there are other nucleons is also discussed [pt

  13. Dynamic bounds coupled with Monte Carlo simulations

    Energy Technology Data Exchange (ETDEWEB)

    Rajabalinejad, M., E-mail: M.Rajabalinejad@tudelft.n [Faculty of Civil Engineering, Delft University of Technology, Delft (Netherlands); Meester, L.E. [Delft Institute of Applied Mathematics, Delft University of Technology, Delft (Netherlands); Gelder, P.H.A.J.M. van; Vrijling, J.K. [Faculty of Civil Engineering, Delft University of Technology, Delft (Netherlands)

    2011-02-15

    For the reliability analysis of engineering structures a variety of methods is known, of which Monte Carlo (MC) simulation is widely considered to be among the most robust and most generally applicable. To reduce simulation cost of the MC method, variance reduction methods are applied. This paper describes a method to reduce the simulation cost even further, while retaining the accuracy of Monte Carlo, by taking into account widely present monotonicity. For models exhibiting monotonic (decreasing or increasing) behavior, dynamic bounds (DB) are defined, which in a coupled Monte Carlo simulation are updated dynamically, resulting in a failure probability estimate, as well as a strict (non-probabilistic) upper and lower bounds. Accurate results are obtained at a much lower cost than an equivalent ordinary Monte Carlo simulation. In a two-dimensional and a four-dimensional numerical example, the cost reduction factors are 130 and 9, respectively, where the relative error is smaller than 5%. At higher accuracy levels, this factor increases, though this effect is expected to be smaller with increasing dimension. To show the application of DB method to real world problems, it is applied to a complex finite element model of a flood wall in New Orleans.

  14. More loosely bound hadron molecules at CDF?

    CERN Document Server

    Bignamini, C; Piccinini, F; Polosa, A D; Riquer, V; Sabelli, C

    2010-01-01

    In a recent paper we have proposed a method to estimate the prompt production cross section of X(3872) at the Tevatron assuming that this particle is a loosely bound molecule of a D and a D*bar meson. Under this hypothesis we find that it is impossible to explain the high prompt production cross section found by CDF at sigma(X(3872)) \\sim 30-70 nb as our theoretical prediction is about 300 times smaller than the measured one. Following our work, Artoisenet and Braaten, have suggested that final state interactions in the DD*bar system might be so strong to push the result we obtained for the cross section up to the experimental value. Relying on their conclusions we show that the production of another very narrow loosely bound molecule, the X_s=D_s D_s*bar, could be similarly enhanced. X_s should then be detectable at CDF with a mass of 4080 MeV and a prompt production cross section of sigma(X_s) \\sim 1-3 nb.

  15. Generalized bounds for convex multistage stochastic programs

    CERN Document Server

    Künzi, H; Fandel, G; Trockel, W; Basile, A; Drexl, A; Dawid, H; Inderfurth, K; Kürsten, W; Schittko, U

    2005-01-01

    This work was completed during my tenure as a scientific assistant and d- toral student at the Institute for Operations Research at the University of St. Gallen. During that time, I was involved in several industry projects in the field of power management, on the occasion of which I was repeatedly c- fronted with complex decision problems under uncertainty. Although usually hard to solve, I quickly learned to appreciate the benefit of stochastic progr- ming models and developed a strong interest in their theoretical properties. Motivated both by practical questions and theoretical concerns, I became p- ticularly interested in the art of finding tight bounds on the optimal value of a given model. The present work attempts to make a contribution to this important branch of stochastic optimization theory. In particular, it aims at extending some classical bounding methods to broader problem classes of practical relevance. This book was accepted as a doctoral thesis by the University of St. Gallen in June 2004.1...

  16. Phenomenological bounds in inclusive neutrino interactions

    International Nuclear Information System (INIS)

    Aubrecht, G.J. II; Takasugi, E.; Tanaka, K.

    1975-01-01

    Using expressions for the ν and anti ν charged and neutral current cross sections and the electroproduction structure function integral and positivity requirements of the sea contribution, bounds are obtained on sigma/sup anti nu N//sigma/sup anti nu N/, and sigma/sup anti nu N//sub nc//sigma/sup nu N//sub nc/ in the standard model. A bound on sigma/sup anti nu N//sigma/sup nu N/ obtained with a V + A term anti p'γ/sub mu/(1-γ 5 )n is used to rule out such a term in the current. A plot of sigma/sup nu N//sub nc/ + sigma/sup anti nu N//sub nc/ versus sigma/sup nu N//sub nc/ - sigma/sup anti nu N//sub nc/ is introduced to analyze the neutral current data. A new relation connecting moments of y and y distributions at a particular point y/sub n/ for ν and anti ν interactions is found. The results do not depend on the neutral current data

  17. Search for a bound K− pp system

    Directory of Open Access Journals (Sweden)

    Camerini P.

    2010-04-01

    Full Text Available Data from the K− absorption reaction on 6,7Li, 9Be, 13C and 16O have recently been collected by FINUDA at the DAΦNE φ-factory (Laboratori Nazionali di Frascati-INFN, following an earlier lower statitics run on 12C and some other targets. FINUDA is a high acceptance magnetic spectrometer which performed a wide range of studies by detecting the charged particles and neutrons exiting the targets after the absorption event. In this paper it is discussed about the study of the A(K− , Λp reaction in the context of the search for deeply bound $ar{K}$ - nuclear states. The observation of a bump in the Λp invariant mass distribution is discussed in terms of a possible signature of a deeply bound K− pp kaonic cluster as well as of more conventional physics. An overview of the experimental situation in this field will be given.

  18. Albumin nanoparticles targeted with Apo E enter the CNS by transcytosis and are delivered to neurones.

    Science.gov (United States)

    Zensi, Anja; Begley, David; Pontikis, Charles; Legros, Celine; Mihoreanu, Larisa; Wagner, Sylvia; Büchel, Claudia; von Briesen, Hagen; Kreuter, Jörg

    2009-07-01

    The blood-brain barrier (BBB) represents a considerable obstacle to brain entry of the majority of drugs and thus severely restricts the therapy of many serious CNS diseases including brain tumours, brain HIV, Alzheimer and other neurodegenerative diseases. The use of nanoparticles coated with polysorbate 80 or with attached apolipoprotein E has enabled the delivery of drugs across the BBB. However, the mechanism of this enhanced transport is still not fully understood. In this present study, human serum albumin nanoparticles, with covalently bound apolipoprotein E (Apo E) as a targetor as well as without apolipoprotein E, were manufactured and injected intravenously into SV 129 mice. The animals were sacrificed after 15 and 30 min, and their brains were examined by transmission electron microscopy. Only the nanoparticles with covalently bound apolipoprotein E were detected in brain capillary endothelial cells and neurones, whereas no uptake into the brain was detectable with nanoparticles without apolipoprotein E. We have also demonstrated uptake of the albumin/ApoE nanoparticles into mouse endothelial (b.End3) cells in vitro and their intracellular localisation. These findings indicate that nanoparticles with covalently bound apolipoprotein E are taken up into the cerebral endothelium by an endocytic mechanism followed by transcytosis into brain parenchyma.

  19. Reducing Conservatism of Analytic Transient Response Bounds via Shaping Filters

    Science.gov (United States)

    Kwan, Aiyueh; Bedrossian, Nazareth; Jan, Jiann-Woei; Grigoriadis, Karolos; Hua, Tuyen (Technical Monitor)

    1999-01-01

    Recent results show that the peak transient response of a linear system to bounded energy inputs can be computed using the energy-to-peak gain of the system. However, analytically computed peak response bound can be conservative for a class of class bounded energy signals, specifically pulse trains generated from jet firings encountered in space vehicles. In this paper, shaping filters are proposed as a Methodology to reduce the conservatism of peak response analytic bounds. This Methodology was applied to a realistic Space Station assembly operation subject to jet firings. The results indicate that shaping filters indeed reduce the predicted peak response bounds.

  20. Degenerate quantum codes and the quantum Hamming bound

    International Nuclear Information System (INIS)

    Sarvepalli, Pradeep; Klappenecker, Andreas

    2010-01-01

    The parameters of a nondegenerate quantum code must obey the Hamming bound. An important open problem in quantum coding theory is whether the parameters of a degenerate quantum code can violate this bound for nondegenerate quantum codes. In this article we show that Calderbank-Shor-Steane (CSS) codes, over a prime power alphabet q≥5, cannot beat the quantum Hamming bound. We prove a quantum version of the Griesmer bound for the CSS codes, which allows us to strengthen the Rains' bound that an [[n,k,d

  1. Study of Mesoporous Silica Nanoparticles' (MSNs) intracellular trafficking and their application as drug delivery vehicles

    Science.gov (United States)

    Yanes, Rolando Eduardo

    Mesoporous silica nanoparticles (MSNs) are attractive drug delivery vehicle candidates due to their biocompatibility, stability, high surface area and efficient cellular uptake. In this dissertation, I discuss three aspects of MSNs' cellular behavior. First, MSNs are targeted to primary and metastatic cancer cell lines, then their exocytosis from cancer cells is studied, and finally they are used to recover intracellular proteins. Targeting of MSNs to primary cancer cells is achieved by conjugating transferrin on the surface of the mesoporous framework, which resulted in enhancement of nanoparticle uptake and drug delivery efficacy in cells that overexpress the transferrin receptor. Similarly, RGD peptides are used to target metastatic cancer cell lines that over-express integrin alphanubeta3. A circular RGD peptide is bound to the surface of MSNs and the endocytosis and cell killing efficacy of camptothecin loaded nanoparticles is significantly improved in cells that express the target receptor. Besides targeting, I studied the ultimate fate of phosphonate coated mesoporous silica nanoparticles inside cells. I discovered that the nanoparticles are exocytosed from cells through lysosomal exocytosis. The nanoparticles are exocytosed in intact form and the time that they remain inside the cells is affected by the surface properties of the nanoparticles and the type of cells. Cells that have a high rate of lysosomal exocytosis excrete the nanoparticles rapidly, which makes them more resistant to drug loaded nanoparticles because the amount of drug that is released inside the cell is limited. When the exocytosis of MSNs is inhibited, the cell killing efficacy of nanoparticles loaded with camptothecin is enhanced. The discovery that MSNs are exocytosed by cells led to a study to determine if proteins could be recovered from the exocytosed nanoparticles. The procedure to isolate exocytosed zinc-doped iron core MSNs and identify the proteins bound to them was developed

  2. Tight bounds on computing error-correcting codes by bounded-depth circuits with arbitrary gates

    Czech Academy of Sciences Publication Activity Database

    Gál, A.; Hansen, A. K.; Koucký, Michal; Pudlák, Pavel; Viola, E.

    2013-01-01

    Roč. 59, č. 10 (2013), s. 6611-6627 ISSN 0018-9448 R&D Projects: GA AV ČR IAA100190902 Institutional support: RVO:67985840 Keywords : bounded-depth circuits * error-correcting codes * hashing Subject RIV: BA - General Mathematics Impact factor: 2.650, year: 2013 http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6578188

  3. Tight bounds on computing error-correcting codes by bounded-depth circuits with arbitrary gates

    Czech Academy of Sciences Publication Activity Database

    Gál, A.; Hansen, A. K.; Koucký, Michal; Pudlák, Pavel; Viola, E.

    2013-01-01

    Roč. 59, č. 10 (2013), s. 6611-6627 ISSN 0018-9448 R&D Projects: GA AV ČR IAA100190902 Institutional support: RVO:67985840 Keywords : bounded-depth circuits * error -correcting codes * hashing Subject RIV: BA - General Mathematics Impact factor: 2.650, year: 2013 http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6578188

  4. Structure and dynamics of weakly bound complexes

    International Nuclear Information System (INIS)

    Skouteris, D.

    1998-01-01

    The present thesis deals with the spectroscopic and theoretical investigation of weakly bound complexes involving a methane molecule. Studies of these Van der Waals complexes can give valuable information on the relevant intermolecular dynamics and promote the understanding of the interactions between molecules (which can ultimately lead to chemical reactions). Especially interesting are complexes involving molecules of high symmetry (e.g. tetrahedral, such as methane) because of the unusual effects arising from it (selection rules, nuclear Spin statistical weights etc.). The infrared spectrum of the Van der Waals complex between a CH 4 and a N 2 O molecule has been recorded and most of it has been assigned in the region of the N - O stretch (approximately 2225.0 cm -1 ). Despite the fact that this is really a weakly bound complex, it is nevertheless rigid enough so that the standard model for asymmetric top spectra can be applied to it with the usual quantum numbers. From the value of the inertial defect, it turns out that the methane unit is locked in a rigid configuration within the complex rather than freely rotating. The intermolecular distance as well as the tilting angle of the N 2 O linear unit are determined from the rotational constants. The complex itself turns out to have a T - shaped configuration. The infrared spectrum of the Ar - CH 4 complex at the ν 4 (bending) band of methane is also assigned. This is different from the previous one in that the methane unit rotates almost freely Within the complex. As a result, the quantum numbers used to classify rovibrational energy levels include these of the free unit. The concept of 'overall symmetry' is made use of to rationalise selection rules in various sub-bands of the spectrum. Moreover, new terms in the potential anisotropy Hamiltonian are calculated through the use of the overall symmetry concept. These are termed 'mixed anisotropy' terms since they involve both rotational and vibrational degrees of

  5. Helioscope bounds on hidden sector photons

    International Nuclear Information System (INIS)

    Redondo, J.

    2008-01-01

    The flux of hypothetical ''hidden photons'' from the Sun is computed under the assumption that they interact with normal matter only through kinetic mixing with the ordinary standard model photon. Requiring that the exotic luminosity is smaller than the standard photon luminosity provides limits for the mixing parameter down to χ -14 , depending on the hidden photon mass. Furthermore, it is pointed point out that helioscopes looking for solar axions are also sensitive to hidden photons. The recent results of the CAST collaboration are used to further constrain the mixing parameter χ at low masses (m γ' <1 eV) where the luminosity bound is weaker. In this regime the solar hidden photon ux has a sizable contribution of longitudinally polarized hidden photons of low energy which are invisible for current helioscopes. (orig.)

  6. Frenetic Bounds on the Entropy Production

    Science.gov (United States)

    Maes, Christian

    2017-10-01

    We give a systematic derivation of positive lower bounds for the expected entropy production (EP) rate in classical statistical mechanical systems obeying a dynamical large deviation principle. The logic is the same for the return to thermodynamic equilibrium as it is for steady nonequilibria working under the condition of local detailed balance. We recover there recently studied "uncertainty" relations for the EP, appearing in studies about the effectiveness of mesoscopic machines. In general our refinement of the positivity of the expected EP rate is obtained in terms of a positive and even function of the expected current(s) which measures the dynamical activity in the system, a time-symmetric estimate of the changes in the system's configuration. Also underdamped diffusions can be included in the analysis.

  7. Bounded rational choice behaviour: applications in transport

    DEFF Research Database (Denmark)

    Jensen, Anders Fjendbo

    2016-01-01

    Even though the theory of rational behaviour has been challenged for almost 100 years, the dominant approach within the field of transport has been based upon the assumptions of neoclassical economics that we live in a world of rational decision makers who always have perfect knowledge and aim...... rational choice behaviour focuses on how the latter approach can be seriously taken into account within transport applications. As the editors discuss in the introduction, a true optimal choice can only be made if an individual has full and perfect information of all relevant attributes in his/her choice...... set. An individual is said to demonstrate bounded rational behaviour if he/she does not systematically consider all attributes deemed relevant for the decision problem at hand, does not consider all choice options and/or does not choose the best choice alternative. Such simplified representation...

  8. Diffraction scattering of strongly bound system

    International Nuclear Information System (INIS)

    Kuzmichev, V.E.

    1982-04-01

    The scattering of a hadron on a strongly bound system of two hadrons (dihadron) is considered in the high-energy limit for the relative hadron-dihadron motion. The dihadron scatterer motion and the internal interaction are included in our consideration. It is shown that only small values of the internal transfer momentum of dihadron particles bring the principal contribution to the three-particle propagator in eikonal approximation. On the basis of the exact analytical solution of the integral equation for the total Green function the scattering amplitude is derived. It is shown that the scattering amplitude contains only single, double, and triple scattering terms. The three new terms to the Glauber formula for the total cross section are obtained. These terms decrease both the true total hadron-hadron cross section and the screening correction. (orig.)

  9. Transient response in granular bounded heap flows

    Science.gov (United States)

    Xiao, Hongyi; Ottino, Julio M.; Lueptow, Richard M.; Umbanhowar, Paul B.

    2017-11-01

    Heap formation, a canonical granular flow, is common in industry and is also found in nature. Here, we study the transition between steady flow states in quasi-2D bounded heaps by suddenly changing the feed rate from one fixed value to another. During the transition, in both experiments and discrete element method simulations, an additional wedge of flowing particles propagates over the rising free surface. The downstream edge of the wedge - the wedge front - moves downstream with velocity inversely proportional to the square root of time. An additional longer duration transient process continues after the wedge front reaches the downstream wall. The transient flux profile during the entire transition is well modeled by a diffusion-like equation derived from local mass balance and a local linear relation between the flux and the surface slope. Scalings for the transient kinematics during the flow transitions are developed based on the flux profiles. Funded by NSF Grant CBET-1511450.

  10. Similarity problems and completely bounded maps

    CERN Document Server

    Pisier, Gilles

    2001-01-01

    These notes revolve around three similarity problems, appearing in three different contexts, but all dealing with the space B(H) of all bounded operators on a complex Hilbert space H. The first one deals with group representations, the second one with C* -algebras and the third one with the disc algebra. We describe them in detail in the introduction which follows. This volume is devoted to the background necessary to understand these three problems, to the solutions that are known in some special cases and to numerous related concepts, results, counterexamples or extensions which their investigation has generated. While the three problems seem different, it is possible to place them in a common framework using the key concept of "complete boundedness", which we present in detail. Using this notion, the three problems can all be formulated as asking whether "boundedness" implies "complete boundedness" for linear maps satisfying certain additional algebraic identities. Two chapters have been added on the HALMO...

  11. 'Critical' behaviour of weakly bound systems

    International Nuclear Information System (INIS)

    Lassaut, M.; Lombard, R.J.; Bulboaca, I.

    1995-11-01

    The class of 3-dimensional finite range or similar potentials λW(r) is discussed, depending on a strength constant λ. The behaviour of the eigenvalue E as function of λ-λ c is studied, where λ c is the critical value at the transition from 0 → 1 bound state. For the l=0 case, E α (λ-λ c ) 2 was found, whereas the relationship is linear for l≥1. Treating l as a continuous parameter in the radial Schroedinger equation, the evolution of the power-law between l=0 and l=1 is given. Besides spherically symmetric scalar potentials, the case of a repulsive scalar potential combined with a spin-orbit component of the Thomas form is also discussed. (author)

  12. Entanglement negativity bounds for fermionic Gaussian states

    Science.gov (United States)

    Eisert, Jens; Eisler, Viktor; Zimborás, Zoltán

    2018-04-01

    The entanglement negativity is a versatile measure of entanglement that has numerous applications in quantum information and in condensed matter theory. It can not only efficiently be computed in the Hilbert space dimension, but for noninteracting bosonic systems, one can compute the negativity efficiently in the number of modes. However, such an efficient computation does not carry over to the fermionic realm, the ultimate reason for this being that the partial transpose of a fermionic Gaussian state is no longer Gaussian. To provide a remedy for this state of affairs, in this work, we introduce efficiently computable and rigorous upper and lower bounds to the negativity, making use of techniques of semidefinite programming, building upon the Lagrangian formulation of fermionic linear optics, and exploiting suitable products of Gaussian operators. We discuss examples in quantum many-body theory and hint at applications in the study of topological properties at finite temperature.

  13. Dilation volumes of sets of bounded perimeter

    DEFF Research Database (Denmark)

    Kiderlen, Markus; Rataj, Jan

    , this derivative coincides up to sign with the directional derivative of the covariogram of A in direction u. By known results for the covariogram, this derivative can therefore be expressed by the cosine transform of the surface area measure of A. We extend this result to sets Q that are at most countable and use...... it to determine the derivative of the contact distribution function of a stationary random closed set at zero. A variant for uncountable Q is given, too. The proofs are based on approximation of the characteristic function of A by smooth functions of bounded variation and showing corresponding formulas for them....

  14. Hyperquarks and bosonic preon bound states

    International Nuclear Information System (INIS)

    Schmid, Michael L.; Buchmann, Alfons J.

    2009-01-01

    In a model in which leptons, quarks, and the recently introduced hyperquarks are built up from two fundamental spin-(1/2) preons, the standard model weak gauge bosons emerge as preon bound states. In addition, the model predicts a host of new composite gauge bosons, in particular, those responsible for hyperquark and proton decay. Their presence entails a left-right symmetric extension of the standard model weak interactions and a scheme for a partial and grand unification of nongravitational interactions based on, respectively, the effective gauge groups SU(6) P and SU(9) G . This leads to a prediction of the Weinberg angle at low energies in good agreement with experiment. Furthermore, using evolution equations for the effective coupling strengths, we calculate the partial and grand unification scales, the hyperquark mass scale, as well as the mass and decay rate of the lightest hyperhadron.

  15. Factorization Procedure for Harmonically Bound Brownian Particle

    International Nuclear Information System (INIS)

    Omolo, JK.

    2006-01-01

    The method of factorization to solve the problem of the one-dimensional harmonically bound Brownian particle was applied. Assuming the the rapidily fluctuating random force is Gaussian and has an infinitely short correlation time, explicit expressions for the position-position,velocity-velocity, and the position-velocity correlation functions, which are also use to write down appropriate distribution functions were used. The correlation and distribution functions for the complex quantity (amplititude) which provides the expressions for the position and velocity of the particle are calculated. Finally, Fokker-Planck equations for the joint probability distribution functions for the amplititude and it's complex conjugate as well as for the position and velocity of the particle are obtained. (author)

  16. Lower complexity bounds for lifted inference

    DEFF Research Database (Denmark)

    Jaeger, Manfred

    2015-01-01

    instances of the model. Numerous approaches for such “lifted inference” techniques have been proposed. While it has been demonstrated that these techniques will lead to significantly more efficient inference on some specific models, there are only very recent and still quite restricted results that show...... the feasibility of lifted inference on certain syntactically defined classes of models. Lower complexity bounds that imply some limitations for the feasibility of lifted inference on more expressive model classes were established earlier in Jaeger (2000; Jaeger, M. 2000. On the complexity of inference about...... that under the assumption that NETIME≠ETIME, there is no polynomial lifted inference algorithm for knowledge bases of weighted, quantifier-, and function-free formulas. Further strengthening earlier results, this is also shown to hold for approximate inference and for knowledge bases not containing...

  17. Surface-bound states in nanodiamonds

    Science.gov (United States)

    Han, Peng; Antonov, Denis; Wrachtrup, Jörg; Bester, Gabriel

    2017-05-01

    We show via ab initio calculations and an electrostatic model that the notoriously low, but positive, electron affinity of bulk diamond becomes negative for hydrogen passivated nanodiamonds and argue that this peculiar situation (type-II offset with a vacuum level at nearly midgap) and the three further conditions: (i) a surface dipole with positive charge on the outside layer, (ii) a spherical symmetry, and (iii) a dielectric mismatch at the surface, results in the emergence of a peculiar type of surface state localized just outside the nanodiamond. These states are referred to as "surface-bound states" and have consequently a strong environmental sensitivity. These type of states should exist in any nanostructure with negative electron affinity. We further quantify the band offsets of different type of nanostructures as well as the exciton binding energy and contrast the results with results for "conventional" silicon quantum dots.

  18. Volume Stability of Bitumen Bound Building Blocks

    Directory of Open Access Journals (Sweden)

    Thanaya I.N.A.

    2010-01-01

    Full Text Available This paper covers results of laboratory investigations on the volume stability of masonry units incorporating waste materials bound with bitumen (Bitublocks, due to moisture adsorption, thermal exposure and vacuum saturation. The materials used were steel slag, crushed glass, coal fly ash, and 50 pen bitumen. The samples were produced in hot mix method, compacted, then exposed to moist and temperature. It was found that moisture adsorption from the environment caused the Bitublock to expand. The samples with less intense curing regime experienced lower expansion and became stable faster, and vice versa. Under thermal condition (at 70°C, the samples with less intense curing regime underwent higher expansion, and vice versa. They were also highly reversible. Their volume stability was found unique under water exposure. The expansion on first vacuum saturation cycle was irreversible, then largely reversible on the following cycles.

  19. Resignation syndrome: Catatonia? Culture-bound?

    Directory of Open Access Journals (Sweden)

    Karl eSallin

    2016-01-01

    Full Text Available Resignation syndrome (RS designates a long-standing disorder predominately affecting psychologically traumatised children and adolescents in the midst of a strenuous and lengthy migration process. Typically a depressive onset is followed by gradual withdrawal progressing via stupor into a state that prompts tube feeding and is characterised by failure to respond even to painful stimuli. The patient is seemingly unconscious. Recovery ensues within months to years and is claimed to be dependent on the restoration of hope to the family.Descriptions of disorders resembling RS can be found in the literature and the condition is unlikely novel. Nevertheless, the magnitude and geographical distribution stand out. Several hundred cases have been reported exclusively in Sweden in the past decade prompting the Swedish National Board of Health and Welfare to recognise RS as a separate diagnostic entity. The currently prevailing stress hypothesis fails to account for the regional distribution and contributes little to treatment. Consequently, a re-evaluation of diagnostics and treatment is required. Psychogenic catatonia is proposed to supply the best fit with the clinical presentation. Treatment response, altered brain metabolism or preserved awareness would support this hypothesis.Epidemiological data suggests culture-bound beliefs and expectations to generate and direct symptom expression and we argue that culture-bound psychogenesis can accommodate the endemic distribution.Last, we review recent models of predictive coding indicating how expectation processes are crucially involved in the placebo and nocebo effect, delusions and conversion disorders. Building on this theoretical framework we propose a neurobiological model of RS in which the impact of overwhelming negative expectations are directly causative of the down-regulation of higher order and lower order behavioural systems in particularly vulnerable individuals.

  20. Models for light QCD bound states

    International Nuclear Information System (INIS)

    LaCourse, D.P.

    1992-01-01

    After a brief overview of Regge, tower, and heavy-quark experimental data, this thesis examines two massless wave equations relevant to quark bound states. We establish general conditions on the Lorentz scalar and Lorentz vector potentials which yield arbitrary leading Regge trajectories for the case of circular classical motion. A semi-classical approximation which includes radial motion reproduces remarkably well the exact solutions. Conditions for tower structure are examined, and found to be incompatible with conditions which give a Nambu stringlike Regge slope. The author then proposes a generalization of the usual potential model of quark bound states in which the confining flux tube is a dynamical object carrying both angular momentum and energy. The Q bar Q-string system with spinless quarks is quantized using an implicit operator technique and the resulting relativistic wave equation is solved. For heavy quarks the usual Schroedinger valence-quark model is recovered. The Regge slope with light quarks agree with the classical rotating-string result and is significantly larger and the effects of short-range forces are also considered. A relativistic generalization of the quantized flux tube model predicts the glueball ground state mass to be √3/α' ≅ 1.9 GeV where α' is the normal Regge slope. The groundstate as well as excited levels like considerably above the expectations of previous models and also above various proposed experimental candidates. The glueball Regge slope is only about three-eighths that for valence quark hadrons. A semi-classical calculation of the Regge slope is in good agreement with a numerically exact value

  1. Coherent structures in wall-bounded turbulence

    Science.gov (United States)

    Jiménez, Javier

    2018-05-01

    This article discusses the description of wall-bounded turbulence as a deterministic high-dimensional dynamical system of interacting coherent structures, defined as eddies with enough internal dynamics to behave relatively autonomously from any remaining incoherent part of the flow. The guiding principle is that randomness is not a property, but a methodological choice of what to ignore in the flow, and that a complete understanding of turbulence, including the possibility of control, requires that it be kept to a minimum. After briefly reviewing the underlying low-order statistics of flows at moderate Reynolds numbers, the article examines what two-point statistics imply for the decomposition of the flow into individual eddies. Intense eddies are examined next, including their temporal evolution, and shown to satisfy many of the properties required for coherence. In particular, it is shown that coherent structures larger than the Corrsin scale are a natural consequence of the shear. In wall-bounded turbulence, they can be classified into coherent dispersive waves and transient bursts. The former are found in the viscous layer near the wall and as very-large structures spanning the boundary layer thickness. Although they are shear-driven, these waves have enough internal structure to maintain a uniform advection velocity. Conversely, bursts exist at all scales, are characteristic of the logarithmic layer, and interact almost linearly with the shear. While the waves require a wall to determine their length scale, the bursts are essentially independent from it. The article concludes with a brief review of our present theoretical understanding of turbulent structures, and with a list of open problems and future perspectives.

  2. De-alloyed platinum nanoparticles

    Science.gov (United States)

    Strasser, Peter [Houston, TX; Koh, Shirlaine [Houston, TX; Mani, Prasanna [Houston, TX; Ratndeep, Srivastava [Houston, TX

    2011-08-09

    A method of producing de-alloyed nanoparticles. In an embodiment, the method comprises admixing metal precursors, freeze-drying, annealing, and de-alloying the nanoparticles in situ. Further, in an embodiment de-alloyed nanoparticle formed by the method, wherein the nanoparticle further comprises a core-shell arrangement. The nanoparticle is suitable for electrocatalytic processes and devices.

  3. Quantum dot nanoparticle conjugation, characterization, and applications in neuroscience

    Science.gov (United States)

    Pathak, Smita

    Quantum dot are semiconducting nanoparticles that have been used for decades in a variety of applications such as solar cells, LEDs and medical imaging. Their use in the last area, however, has been extremely limited despite their potential as revolutionary new biological labeling tools. Quantum dots are much brighter and more stable than conventional fluorophores, making them optimal for high resolution imaging and long term studies. Prior work in this area involves synthesizing and chemically conjugating quantum dots to molecules of interest in-house. However this method is both time consuming and prone to human error. Additionally, non-specific binding and nanoparticle aggregation currently prevent researchers from utilizing this system to its fullest capacity. Another critical issue that has not been addressed is determining the number of ligands bound to nanoparticles, which is crucial for proper interpretation of results. In this work, methods to label fixed cells using two types of chemically modified quantum dots are studied. Reproducible non-specific artifact labeling is consistently demonstrated if antibody-quantum dot conditions are less than optimal. In order to explain this, antibodies bound to quantum dots were characterized and quantified. While other groups have qualitatively characterized antibody functionalized quantum dots using TEM, AFM, UV spectroscopy and gel electrophoresis, and in some cases have reported calculated estimates of the putative number of total antibodies bound to quantum dots, no quantitative experimental results had been reported prior to this work. The chemical functionalization and characterization of quantum dot nanocrystals achieved in this work elucidates binding mechanisms of ligands to nanoparticles and allows researchers to not only translate our tools to studies in their own areas of interest but also derive quantitative results from these studies. This research brings ease of use and increased reliability to

  4. An Effective Delivery System of Sitagliptin Using Optimized Mucoadhesive Nanoparticles

    Directory of Open Access Journals (Sweden)

    Afzal Haq Asif

    2018-05-01

    Full Text Available Sitagliptin (MK-0431, is a potent oral hypoglycemic drug that is used for treating type 2 diabetes mellitus. However, the short half-life of sitagliptin requires patients to take a high dose of 50 mg twice per day, and the fraction of sitagliptin reversibly bound to plasma proteins is as low as 38%. In addition, it was reported that approximately 79% of sitagliptin is excreted unchanged in the urine for elimination without metabolism. Thus, a better delivery system is needed to improve the benefits of sitagliptin in patients. The drug content and percentage yield were found to be 73 ± 2% and 92 ± 2%, respectively. The optimized sitagliptin nanoparticle sizes were between 350–950 nm, and the surfaces were smooth and nearly spherical in shape. In addition, the optimized sitagliptin nanoparticles have an indicated excellent bioadhesion property of (6.1 ± 0.5 h. The swelling of the nanoparticles is 168 ± 15%. The pattern of sitagliptin release from the mucoadhesive nanoparticles follows the Korsmeyer-Peppas model. More importantly, the extended sitagliptin retention time, of up to 12 h in the gastrointestinal tract, suggests that the optimized mucoadhesive nanoparticle formulation is more efficient, and has a greater potential to be used for oral delivery compared to the conventional sitagliptin administration in the drug solution. This is the first developed delivery system using the optimized mucoadhesive nanoparticles to enhance the effectiveness of sitagliptin.

  5. Study of dithiol monolayer as the interface for controlled deposition of gold nanoparticles

    International Nuclear Information System (INIS)

    Cichomski, M.; Tomaszewska, E.; Kosla, K.; Kozlowski, W.; Kowalczyk, P.J.; Grobelny, J.

    2011-01-01

    Self-assembled monolayer of dithiol molecules, deposited on polycrystalline Au (111), prepared at room atmosphere, was studied using scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). Dithiols were used as interface, which chemically bonds to the deposited gold nanoparticles through strong covalent bonds. The size and size distribution of the deposited nanoparticles were measured using dynamic light scattering (DLS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The AFM results showed that nanoparticles are immobilized and stable during scanning procedure and do not contaminate the AFM tip. The size of monodisperse nanoparticles obtained from the DLS measurements is slightly higher than that obtained from the AFM and SEM measurements. This is due to the fact that the DLS measures the hydrodynamic radius, dependent on the protective chemical layer on nanoparticles. - Research Highlights: → Dithiols molecules create chemically bounded layers on a Au (111) surface. → Gold nanoparticles can be chemically bounded to a self-assembled monolayer. → Nanoparticles are stable during AFM probe interactions.

  6. Can Nano-Particle Melt below the Melting Temperature of Its Free Surface Partner?

    International Nuclear Information System (INIS)

    Sui Xiao-Hong; Qin Shao-Jing; Wang Zong-Guo; Kang Kai; Wang Chui-Lin

    2015-01-01

    The phonon thermal contribution to the melting temperature of nano-particles is inspected. The discrete summation of phonon states and its corresponding integration form as an approximation for a nano-particle or for a bulk system have been analyzed. The discrete phonon energy levels of pure size effect and the wave-vector shifts of boundary conditions are investigated in detail. Unlike in macroscopic thermodynamics, the integration volume of zero-mode of phonon for a nano-particle is not zero, and it plays an important role in pure size effect and boundary condition effect. We find that a nano-particle will have a rising melting temperature due to purely finite size effect; a lower melting temperature bound exists for a nano-particle in various environments, and the melting temperature of a nano-particle with free boundary condition reaches this lower bound. We suggest an easy procedure to estimation the melting temperature, in which the zero-mode contribution will be excluded, and only several bulk quantities will be used as input. We would like to emphasize that the quantum effect of discrete energy levels in nano-particles, which is not present in early thermodynamic studies on finite size corrections to melting temperature in small systems, should be included in future researches. (condensed matter: structural, mechanical, and thermal properties)

  7. Nanoparticle mediated micromotor motion

    Science.gov (United States)

    Liu, Mei; Liu, Limei; Gao, Wenlong; Su, Miaoda; Ge, Ya; Shi, Lili; Zhang, Hui; Dong, Bin; Li, Christopher Y.

    2015-03-01

    In this paper, we report the utilization of nanoparticles to mediate the motion of a polymer single crystal catalytic micromotor. Micromotors have been fabricated by directly self-assembling functional nanoparticles (platinum and iron oxide nanoparticles) onto one or both sides of two-dimensional polymer single crystals. We show that the moving velocity of these micromotors in fluids can be readily tuned by controlling the nanoparticles' surface wettability and catalytic activity. A 3 times velocity increase has been achieved for a hydrophobic micromotor as opposed to the hydrophilic ones. Furthermore, we demonstrate that the catalytic activity of platinum nanoparticles inside the micromotor can be enhanced by their synergetic interactions with iron oxide nanoparticles and an electric field. Both strategies lead to dramatically increased moving velocities, with the highest value reaching ~200 μm s-1. By decreasing the nanoparticles' surface wettability and increasing their catalytic activity, a maximum of a ~10-fold increase in the moving speed of the nanoparticle based micromotor can be achieved. Our results demonstrate the advantages of using nanoparticles in micromotor systems.In this paper, we report the utilization of nanoparticles to mediate the motion of a polymer single crystal catalytic micromotor. Micromotors have been fabricated by directly self-assembling functional nanoparticles (platinum and iron oxide nanoparticles) onto one or both sides of two-dimensional polymer single crystals. We show that the moving velocity of these micromotors in fluids can be readily tuned by controlling the nanoparticles' surface wettability and catalytic activity. A 3 times velocity increase has been achieved for a hydrophobic micromotor as opposed to the hydrophilic ones. Furthermore, we demonstrate that the catalytic activity of platinum nanoparticles inside the micromotor can be enhanced by their synergetic interactions with iron oxide nanoparticles and an electric

  8. Recent Advances in the Application of Magnetic Nanoparticles as a Support for Homogeneous Catalysts

    Science.gov (United States)

    Govan, Joseph; Gun’ko, Yurii K.

    2014-01-01

    Magnetic nanoparticles are a highly valuable substrate for the attachment of homogeneous inorganic and organic containing catalysts. This review deals with the very recent main advances in the development of various nanocatalytic systems by the immobilisation of homogeneous catalysts onto magnetic nanoparticles. We discuss magnetic core shell nanostructures (e.g., silica or polymer coated magnetic nanoparticles) as substrates for catalyst immobilisation. Then we consider magnetic nanoparticles bound to inorganic catalytic mesoporous structures as well as metal organic frameworks. Binding of catalytically active small organic molecules and polymers are also reviewed. After that we briefly deliberate on the binding of enzymes to magnetic nanocomposites and the corresponding enzymatic catalysis. Finally, we draw conclusions and present a future outlook for the further development of new catalytic systems which are immobilised onto magnetic nanoparticles. PMID:28344220

  9. Electron spin resonance spectroscopy for immunoassay using iron oxide nanoparticles as probe.

    Science.gov (United States)

    Jiang, Jia; Tian, Sizhu; Wang, Kun; Wang, Yang; Zang, Shuang; Yu, Aimin; Zhang, Ziwei

    2018-02-01

    With the help of iron oxide nanoparticles, electron spin resonance spectroscopy (ESR) was applied to immunoassay. Iron oxide nanoparticles were used as the ESR probe in order to achieve an amplification of the signal resulting from the large amount of Fe 3+ ion enclosed in each nanoparticle. Rabbit IgG was used as antigen to test this method. Polyclonal antibody of rabbit IgG was used as antibody to detect the antigen. Iron oxide nanoparticle with a diameter of either 10 or 30 nm was labeled to the antibody, and Fe 3+ in the nanoparticle was probed for ESR signal. The sepharose beads were used as solid phase to which rabbit IgG was conjugated. The nanoparticle-labeled antibody was first added in the sample containing antigen, and the antigen-conjugated sepharose beads were then added into the sample. The nanoparticle-labeled antibody bound to the antigen on sepharose beads was separated from the sample by centrifugation and measured. We found that the detection ranges of the antigen obtained with nanoparticles of different sizes were different because the amount of antibody on nanoparticles of 10 nm was about one order of magnitude higher than that on nanoparticles of 30 nm. When 10 nm nanoparticle was used as probe, the upper limit of detection was 40.00 μg mL -1 , and the analytical sensitivity was 1.81 μg mL -1 . When 30 nm nanoparticle was used, the upper limit of detection was 3.00 μg mL -1 , and the sensitivity was 0.014 and 0.13 μg mL -1 depending on the ratio of nanoparticle to antibody. Graphical abstract Schematic diagram of procedure and ESR spectra.

  10. A nanoparticle in plasma

    International Nuclear Information System (INIS)

    Martynenko, Yu. V.; Nagel', M. Yu.; Orlov, M. A.

    2009-01-01

    Charge and energy fluxes onto a nanoparticle under conditions typical of laboratory plasmas are investigated theoretically. Here, by a nanoparticle is meant a grain the size of which is much smaller than both the electron Larmor radius and Debye length and the thermionic emission from which is not limited by the space charge. Under conditions at which thermionic emission plays an important role, the electric potential and temperature T p of a nanoparticle are determined by solving a self-consistent set of equations describing the balance of energy and charge fluxes onto the nanoparticle. It is shown that, when the degree of plasma ionization exceeds a critical level, the potential of the nanoparticle and the energy flux onto it increase with increasing nanoparticle temperature, so that, starting from a certain temperature, the nanoparticle potential becomes positive. The critical degree of ionization starting from which the potential of a nanoparticle is always positive is determined as a function of the plasma density and electron temperature. The nanoparticle temperature T p corresponding to the equilibrium state of a positively charged nanoparticle is found as a function of the electron density for different electron temperatures.

  11. The neural basis of bounded rational behavior

    Directory of Open Access Journals (Sweden)

    Coricelli, Giorgio

    2012-03-01

    Full Text Available Bounded rational behaviour is commonly observed in experimental games and in real life situations. Neuroeconomics can help to understand the mental processing underlying bounded rationality and out-of-equilibrium behaviour. Here we report results from recent studies on the neural basis of limited steps of reasoning in a competitive setting —the beauty contest game. We use functional magnetic resonance imaging (fMRI to study the neural correlates of human mental processes in strategic games. We apply a cognitive hierarchy model to classify subject’s choices in the experimental game according to the degree of strategic reasoning so that we can identify the neural substrates of different levels of strategizing. We found a correlation between levels of strategic reasoning and activity in a neural network related to mentalizing, i.e. the ability to think about other’s thoughts and mental states. Moreover, brain data showed how complex cognitive processes subserve the higher level of reasoning about others. We describe how a cognitive hierarchy model fits both behavioural and brain data.

    La racionalidad limitada es un fenómeno observado de manera frecuente tanto en juegos experimentales como en situaciones cotidianas. La Neuroeconomía puede mejorar la comprensión de los procesos mentales que caracterizan la racionalidad limitada; en paralelo nos puede ayudar a comprender comportamientos que violan el equilibrio. Nuestro trabajo presenta resultados recientes sobre la bases neuronales del razonamiento estratégico (y sus límite en juegos competitivos —como el juego del “beauty contest”. Estudiamos las bases neuronales del comportamiento estratégico en juegos con interacción entre sujetos usando resonancia magnética funcional (fMRI. Las decisiones de los participantes se clasifican acorde al grado de razonamiento estratégico: el llamado modelo de Jerarquías Cognitivas. Los resultados muestran una correlación entre niveles de

  12. Tight bounds on computing error-correcting codes by bounded-depth circuits with arbitrary gates

    DEFF Research Database (Denmark)

    Gal, A.; Hansen, Kristoffer Arnsfelt; Koucky, Michal

    2013-01-01

    We bound the minimum number w of wires needed to compute any (asymptotically good) error-correcting code C:{0,1}Ω(n)→{0,1}n with minimum distance Ω(n), using unbounded fan-in circuits of depth d with arbitrary gates. Our main results are: 1) if d=2, then w=Θ(n (lgn/lglgn)2); 2) if d=3, then w...

  13. Tight bounds on computing error-correcting codes by bounded-depth circuits with arbitrary gates

    DEFF Research Database (Denmark)

    Gál, Anna; Hansen, Kristoffer Arnsfelt; Koucký, Michal

    2012-01-01

    We bound the minimum number w of wires needed to compute any (asymptotically good) error-correcting code C:{0,1}Ω(n) -> {0,1}n with minimum distance Ω(n), using unbounded fan-in circuits of depth d with arbitrary gates. Our main results are: (1) If d=2 then w = Θ(n ({log n/ log log n})2). (2) If d...

  14. Persistence-Based Branch Misprediction Bounds for WCET Analysis

    DEFF Research Database (Denmark)

    Puffitsch, Wolfgang

    2015-01-01

    Branch prediction is an important feature of pipelined processors to achieve high performance. However, it can lead to overly pessimistic worst-case execution time (WCET) bounds when being modeled too conservatively. This paper presents bounds on the number of branch mispredictions for local...... dynamic branch predictors. To handle interferences between branch instructions we use the notion of persistence, a concept that is also found in cache analyses. The bounds apply to branches in general, not only to branches that close a loop. Furthermore, the bounds can be easily integrated into integer...... linear programming formulations of the WCET problem. An evaluation on a number of benchmarks shows that with these bounds, dynamic branch prediction does not necessarily lead to higher WCET bounds than static prediction schemes....

  15. Architecture-independent power bound for vibration energy harvesters

    International Nuclear Information System (INIS)

    Halvorsen, E; Le, C P; Mitcheson, P D; Yeatman, E M

    2013-01-01

    The maximum output power of energy harvesters driven by harmonic vibrations is well known for a range of specific harvester architectures. An architecture-independent bound based on the mechanical input-power also exists and gives a strict limit on achievable power with one mechanical degree of freedom, but is a least upper bound only for lossless devices. We report a new theoretical bound on the output power of vibration energy harvesters that includes parasitic, linear mechanical damping while still being architecture independent. This bound greatly improves the previous bound at moderate force amplitudes and is compared to the performance of established harvester architectures which are shown to agree with it in limiting cases. The bound is a hard limit on achievable power with one mechanical degree of freedom and can not be circumvented by transducer or power-electronic-interface design

  16. Sharp bounds for periodic solutions of Lipschitzian differential equations

    International Nuclear Information System (INIS)

    Zevin, A A

    2009-01-01

    A general system of Lipschitzian differential equations, containing simultaneously terms without delay and with arbitrary constant and time-varying delays, is considered. For the autonomous case, a lower bound for the period of nonconstant periodic solutions, expressed in the respective supremum Lipschitz constants, is found. For nonautonomous periodic equations, explicit upper bounds for the amplitudes and maximum derivatives of periodic solutions are obtained. For all n ≥ 2, the bounds do not depend on n and, in general, are different from that for n = 1. All the bounds are sharp; they are attained in linear differential equations with piece-wise constant deviating arguments. A relation between the obtained bounds and the sharp bounds in other metrics is established

  17. ``Carbon Credits'' for Resource-Bounded Computations Using Amortised Analysis

    Science.gov (United States)

    Jost, Steffen; Loidl, Hans-Wolfgang; Hammond, Kevin; Scaife, Norman; Hofmann, Martin

    Bounding resource usage is important for a number of areas, notably real-time embedded systems and safety-critical systems. In this paper, we present a fully automatic static type-based analysis for inferring upper bounds on resource usage for programs involving general algebraic datatypes and full recursion. Our method can easily be used to bound any countable resource, without needing to revisit proofs. We apply the analysis to the important metrics of worst-case execution time, stack- and heap-space usage. Our results from several realistic embedded control applications demonstrate good matches between our inferred bounds and measured worst-case costs for heap and stack usage. For time usage we infer good bounds for one application. Where we obtain less tight bounds, this is due to the use of software floating-point libraries.

  18. Lying for the Greater Good: Bounded Rationality in a Team

    OpenAIRE

    Oktay Sürücü

    2014-01-01

    This paper is concerned with the interaction between fully and boundedly rational agents in situations where their interests are perfectly aligned. The cognitive limitations of the boundedly rational agent do not allow him to fully understand the market conditions and lead him to take non-optimal decisions in some situations. Using categorization to model bounded rationality, we show that the fully rational agent can nudge, i.e., he can manipulate the information he sends and decrease the exp...

  19. Upper bounds on minimum cardinality of exact and approximate reducts

    KAUST Repository

    Chikalov, Igor

    2010-01-01

    In the paper, we consider the notions of exact and approximate decision reducts for binary decision tables. We present upper bounds on minimum cardinality of exact and approximate reducts depending on the number of rows (objects) in the decision table. We show that the bound for exact reducts is unimprovable in the general case, and the bound for approximate reducts is almost unimprovable in the general case. © 2010 Springer-Verlag Berlin Heidelberg.

  20. Entropic Lower Bound for Distinguishability of Quantum States

    Directory of Open Access Journals (Sweden)

    Seungho Yang

    2015-01-01

    Full Text Available For a system randomly prepared in a number of quantum states, we present a lower bound for the distinguishability of the quantum states, that is, the success probability of determining the states in the form of entropy. When the states are all pure, acquiring the entropic lower bound requires only the density operator and the number of the possible states. This entropic bound shows a relation between the von Neumann entropy and the distinguishability.

  1. Uniform Bounds for Black--Scholes Implied Volatility

    OpenAIRE

    Tehranchi, Michael Rummine

    2016-01-01

    In this note, Black--Scholes implied volatility is expressed in terms of various optimization problems. From these representations, upper and lower bounds are derived which hold uniformly across moneyness and call price. Various symmetries of the Black--Scholes formula are exploited to derive new bounds from old. These bounds are used to reprove asymptotic formulas for implied volatility at extreme strikes and/or maturities. the Society for Industrial and Applied Mathematics 10.1137/14095248X

  2. Uniform bounds for Black--Scholes implied volatility

    OpenAIRE

    Tehranchi, Michael R.

    2015-01-01

    In this note, Black--Scholes implied volatility is expressed in terms of various optimisation problems. From these representations, upper and lower bounds are derived which hold uniformly across moneyness and call price. Various symmetries of the Black--Scholes formula are exploited to derive new bounds from old. These bounds are used to reprove asymptotic formulae for implied volatility at extreme strikes and/or maturities.

  3. On an extension of the space of bounded deformations

    Czech Academy of Sciences Publication Activity Database

    Kružík, Martin; Zimmer, J.

    2012-01-01

    Roč. 31, č. 1 (2012), s. 75-91 ISSN 0232-2064 R&D Projects: GA AV ČR IAA100750802 Institutional research plan: CEZ:AV0Z10750506 Keywords : Bounded sequences of symmetrised gradients * bounded deformation Subject RIV: BA - General Mathematics Impact factor: 0.620, year: 2012 http://library.utia.cas.cz/separaty/2012/MTR/kruzik-on an extension of the space of bounded deformations.pdf

  4. Multifunctional nanoparticles: Analytical prospects

    International Nuclear Information System (INIS)

    Dios, Alejandro Simon de; Diaz-Garcia, Marta Elena

    2010-01-01

    Multifunctional nanoparticles are among the most exciting nanomaterials with promising applications in analytical chemistry. These applications include (bio)sensing, (bio)assays, catalysis and separations. Although most of these applications are based on the magnetic, optical and electrochemical properties of multifunctional nanoparticles, other aspects such as the synergistic effect of the functional groups and the amplification effect associated with the nanoscale dimension have also been observed. Considering not only the nature of the raw material but also the shape, there is a huge variety of nanoparticles. In this review only magnetic, quantum dots, gold nanoparticles, carbon and inorganic nanotubes as well as silica, titania and gadolinium oxide nanoparticles are addressed. This review presents a narrative summary on the use of multifuncional nanoparticles for analytical applications, along with a discussion on some critical challenges existing in the field and possible solutions that have been or are being developed to overcome these challenges.

  5. Nanoparticles and direct immunosuppression

    Science.gov (United States)

    Ngobili, Terrika A

    2016-01-01

    Targeting the immune system with nanomaterials is an intensely active area of research. Specifically, the capability to induce immunosuppression is a promising complement for drug delivery and regenerative medicine therapies. Many novel strategies for immunosuppression rely on nanoparticles as delivery vehicles for small-molecule immunosuppressive compounds. As a consequence, efforts in understanding the mechanisms in which nanoparticles directly interact with the immune system have been overshadowed. The immunological activity of nanoparticles is dependent on the physiochemical properties of the nanoparticles and its subsequent cellular internalization. As the underlying factors for these reactions are elucidated, more nanoparticles may be engineered and evaluated for inducing immunosuppression and complementing immunosuppressive drugs. This review will briefly summarize the state-of-the-art and developments in understanding how nanoparticles induce immunosuppressive responses, compare the inherent properties of nanomaterials which induce these immunological reactions, and comment on the potential for using nanomaterials to modulate and control the immune system. PMID:27229901

  6. General bounds in Hybrid Natural Inflation

    Science.gov (United States)

    Germán, Gabriel; Herrera-Aguilar, Alfredo; Hidalgo, Juan Carlos; Sussman, Roberto A.; Tapia, José

    2017-12-01

    Recently we have studied in great detail a model of Hybrid Natural Inflation (HNI) by constructing two simple effective field theories. These two versions of the model allow inflationary energy scales as small as the electroweak scale in one of them or as large as the Grand Unification scale in the other, therefore covering the whole range of possible energy scales. In any case the inflationary sector of the model is of the form V(phi)=V0 (1+a cos(phi/f)) where 0waterfall field. One interesting characteristic of this model is that the slow-roll parameter epsilon(phi) is a non-monotonic function of phi presenting a maximum close to the inflection point of the potential. Because the scalar spectrum Script Ps(k) of density fluctuations when written in terms of the potential is inversely proportional to epsilon(phi) we find that Script Ps(k) presents a minimum at phimin. The origin of the HNI potential can be traced to a symmetry breaking phenomenon occurring at some energy scale f which gives rise to a (massless) Goldstone boson. Non-perturbative physics at some temperature Tmodels is not common. We use this property of HNI to determine bounds for the inflationary energy scale Δ and for the tensor-to-scalar ratio r.

  7. Probabilistic error bounds for reduced order modeling

    Energy Technology Data Exchange (ETDEWEB)

    Abdo, M.G.; Wang, C.; Abdel-Khalik, H.S., E-mail: abdo@purdue.edu, E-mail: wang1730@purdue.edu, E-mail: abdelkhalik@purdue.edu [Purdue Univ., School of Nuclear Engineering, West Lafayette, IN (United States)

    2015-07-01

    Reduced order modeling has proven to be an effective tool when repeated execution of reactor analysis codes is required. ROM operates on the assumption that the intrinsic dimensionality of the associated reactor physics models is sufficiently small when compared to the nominal dimensionality of the input and output data streams. By employing a truncation technique with roots in linear algebra matrix decomposition theory, ROM effectively discards all components of the input and output data that have negligible impact on reactor attributes of interest. This manuscript introduces a mathematical approach to quantify the errors resulting from the discarded ROM components. As supported by numerical experiments, the introduced analysis proves that the contribution of the discarded components could be upper-bounded with an overwhelmingly high probability. The reverse of this statement implies that the ROM algorithm can self-adapt to determine the level of the reduction needed such that the maximum resulting reduction error is below a given tolerance limit that is set by the user. (author)

  8. Tensor squeezed limits and the Higuchi bound

    Energy Technology Data Exchange (ETDEWEB)

    Bordin, Lorenzo [SISSA, via Bonomea 265, 34136, Trieste (Italy); Creminelli, Paolo [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151, Trieste (Italy); Mirbabayi, Mehrdad [Institute for Advanced Study, Princeton, NJ 08540 (United States); Noreña, Jorge, E-mail: lbordin@sissa.it, E-mail: creminel@ictp.it, E-mail: mehrdadm@ias.edu, E-mail: jorge.norena@pucv.cl [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Curauma, Valparaíso (Chile)

    2016-09-01

    We point out that tensor consistency relations—i.e. the behavior of primordial correlation functions in the limit a tensor mode has a small momentum—are more universal than scalar consistency relations. They hold in the presence of multiple scalar fields and as long as anisotropies are diluted exponentially fast. When de Sitter isometries are approximately respected during inflation this is guaranteed by the Higuchi bound, which forbids the existence of light particles with spin: de Sitter space can support scalar hair but no curly hair. We discuss two indirect ways to look for the violation of tensor consistency relations in observations, as a signature of models in which inflation is not a strong isotropic attractor, such as solid inflation: (a) graviton exchange contribution to the scalar four-point function; (b) quadrupolar anisotropy of the scalar power spectrum due to super-horizon tensor modes. This anisotropy has a well-defined statistics which can be distinguished from cases in which the background has a privileged direction.

  9. Decision theory with resource-bounded agents.

    Science.gov (United States)

    Halpern, Joseph Y; Pass, Rafael; Seeman, Lior

    2014-04-01

    There have been two major lines of research aimed at capturing resource-bounded players in game theory. The first, initiated by Rubinstein (), charges an agent for doing costly computation; the second, initiated by Neyman (), does not charge for computation, but limits the computation that agents can do, typically by modeling agents as finite automata. We review recent work on applying both approaches in the context of decision theory. For the first approach, we take the objects of choice in a decision problem to be Turing machines, and charge players for the "complexity" of the Turing machine chosen (e.g., its running time). This approach can be used to explain well-known phenomena like first-impression-matters biases (i.e., people tend to put more weight on evidence they hear early on) and belief polarization (two people with different prior beliefs, hearing the same evidence, can end up with diametrically opposed conclusions) as the outcomes of quite rational decisions. For the second approach, we model people as finite automata, and provide a simple algorithm that, on a problem that captures a number of settings of interest, provably performs optimally as the number of states in the automaton increases. Copyright © 2014 Cognitive Science Society, Inc.

  10. Boudot's Range-Bounded Commitment Scheme Revisited

    Science.gov (United States)

    Cao, Zhengjun; Liu, Lihua

    Checking whether a committed integer lies in a specific interval has many cryptographic applications. In Eurocrypt'98, Chan et al. proposed an instantiation (CFT Proof). Based on CFT, Boudot presented a popular range-bounded commitment scheme in Eurocrypt'2000. Both CFT Proof and Boudot Proof are based on the encryption E(x, r)=g^xh^r mod n, where n is an RSA modulus whose factorization is unknown by the prover. They did not use a single base as usual. Thus an increase in cost occurs. In this paper, we show that it suffices to adopt a single base. The cost of the modified Boudot Proof is about half of that of the original scheme. Moreover, the key restriction in the original scheme, i.e., both the discrete logarithm of g in base h and the discrete logarithm of h in base g are unknown by the prover, which is a potential menace to the Boudot Proof, is definitely removed.

  11. Dynamics of water bound to crystalline cellulose

    Energy Technology Data Exchange (ETDEWEB)

    O’Neill, Hugh; Pingali, Sai Venkatesh; Petridis, Loukas; He, Junhong; Mamontov, Eugene; Hong, Liang; Urban, Volker; Evans, Barbara; Langan, Paul; Smith, Jeremy C.; Davison, Brian H.

    2017-09-19

    Interactions of water with cellulose are of both fundamental and technological importance. Here, we characterize the properties of water associated with cellulose using deuterium labeling, neutron scattering and molecular dynamics simulation. Quasi-elastic neutron scattering provided quantitative details about the dynamical relaxation processes that occur and was supported by structural characterization using small-angle neutron scattering and X-ray diffraction. We can unambiguously detect two populations of water associated with cellulose. The first is “non-freezing bound” water that gradually becomes mobile with increasing temperature and can be related to surface water. The second population is consistent with confined water that abruptly becomes mobile at ~260 K, and can be attributed to water that accumulates in the narrow spaces between the microfibrils. Quantitative analysis of the QENS data showed that, at 250 K, the water diffusion coefficient was 0.85 ± 0.04 × 10-10 m2sec-1 and increased to 1.77 ± 0.09 × 10-10 m2sec-1 at 265 K. MD simulations are in excellent agreement with the experiments and support the interpretation that water associated with cellulose exists in two dynamical populations. Our results provide clarity to previous work investigating the states of bound water and provide a new approach for probing water interactions with lignocellulose materials.

  12. Bounding the Higgs boson width through interferometry.

    Science.gov (United States)

    Dixon, Lance J; Li, Ye

    2013-09-13

    We study the change in the diphoton-invariant-mass distribution for Higgs boson decays to two photons, due to interference between the Higgs resonance in gluon fusion and the continuum background amplitude for gg→γγ. Previously, the apparent Higgs mass was found to shift by around 100 MeV in the standard model in the leading-order approximation, which may potentially be experimentally observable. We compute the next-to-leading-order QCD corrections to the apparent mass shift, which reduce it by about 40%. The apparent mass shift may provide a way to measure, or at least bound, the Higgs boson width at the Large Hadron Collider through "interferometry." We investigate how the shift depends on the Higgs width, in a model that maintains constant Higgs boson signal yields. At Higgs widths above 30 MeV, the mass shift is over 200 MeV and increases with the square root of the width. The apparent mass shift could be measured by comparing with the ZZ* channel, where the shift is much smaller. It might be possible to measure the shift more accurately by exploiting its strong dependence on the Higgs transverse momentum.

  13. Photochemistry of triarylmethane dyes bound to proteins

    Science.gov (United States)

    Indig, Guilherme L.

    1996-04-01

    Triarylmethanes represent a class of cationic dyes whose potential as photosensitizers for use in photodynamic therapy of neoplastic diseases has never been comprehensively evaluated. Here, the laser-induced photodecomposition of three triarylmethane dyes, crystal violet, ethyl violet, and malachite green, non-covalently bound to bovine serum albumin (a model biological target) was investigated. Upon laser excitation at 532 nm, the bleaching of the corresponding dye-protein molecular complexes follows spectroscopic patterns that suggest the formation of reduced forms of the dyes as major reaction photoproducts. That implies that an electron or hydrogen atom transfer from the protein to the dye's moiety within the guest-host complex is the first step of the photobleaching process. Since the availability of dissolved molecular oxygen was not identified as a limiting factor for the phototransformations to occur, these dyes can be seen as potential phototherapeutic agents for use in hypoxic areas of tumors. These triarylmethane dyes strongly absorb at relatively long wavelengths (absorption maximum around 600 nm; (epsilon) max approximately equals 105 M-1 cm-1), and only minor changes in their absorption characteristics are observed upon binding to the protein. However the binding event leads to a remarkable increase in their fluorescence quantum yield and photoreactivity.

  14. Phenomenology of wall-bounded Newtonian turbulence.

    Science.gov (United States)

    L'vov, Victor S; Pomyalov, Anna; Procaccia, Itamar; Zilitinkevich, Sergej S

    2006-01-01

    We construct a simple analytic model for wall-bounded turbulence, containing only four adjustable parameters. Two of these parameters are responsible for the viscous dissipation of the components of the Reynolds stress tensor. The other two parameters control the nonlinear relaxation of these objects. The model offers an analytic description of the profiles of the mean velocity and the correlation functions of velocity fluctuations in the entire boundary region, from the viscous sublayer, through the buffer layer, and further into the log-law turbulent region. In particular, the model predicts a very simple distribution of the turbulent kinetic energy in the log-law region between the velocity components: the streamwise component contains a half of the total energy whereas the wall-normal and cross-stream components contain a quarter each. In addition, the model predicts a very simple relation between the von Kármán slope k and the turbulent velocity in the log-law region v+ (in wall units): v+=6k. These predictions are in excellent agreement with direct numerical simulation data and with recent laboratory experiments.

  15. Organically bound tritium analysis in environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Baglan, N. [CEA/DAM/DIF, Arpajon (France); Kim, S.B. [AECL, Chalk River Laboratories, Chalk River, ON (Canada); Cossonnet, C. [IRSN/PRP-ENV/STEME/LMRE, Orsay (France); Croudace, I.W.; Warwick, P.E. [GAU-Radioanalytical, University of Southampton, Southampton (United Kingdom); Fournier, M. [IRSN/DG/DMQ, Fontenay-aux-Roses (France); Galeriu, D. [IFIN-HH, Horia-Hulubei, Inst. Phys. and Nucl. Eng., Bucharest (Romania); Momoshima, N. [Kyushu University, Radioisotope Ctr., Fukuoka (Japan); Ansoborlo, E. [CEA/DEN/DRCP/CETAMA, Bagnols-sur-Ceze (France)

    2015-03-15

    Organically bound tritium (OBT) has become of increased interest within the last decade, with a focus on its behaviour and also its analysis, which are important to assess tritium distribution in the environment. In contrast, there are no certified reference materials and no standard analytical method through the international organization related to OBT. In order to resolve this issue, an OBT international working group was created in May 2012. Over 20 labs from around the world participated and submitted their results for the first intercomparison exercise results on potato (Sep 2013). The samples, specially-prepared potatoes, were provided in March 2013 to each participant. Technical information and results from this first exercise are discussed here for all the labs which have realised the five replicates necessary to allow a reliable statistical treatment. The results are encouraging as the increased number of participating labs did not degrade the observed dispersion of the results for a similar activity level. Therefore, the results do not seem to depend on the analytical procedure used. From this work an optimised procedure can start to be developed to deal with OBT analysis and will guide subsequent planned OBT trials by the international group.

  16. Revisiting cosmological bounds on sterile neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Vincent, Aaron C. [Institute for Particle Physics Phenomenology (IPPP), Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Martínez, Enrique Fernández [Departamento and Instituto de Física Teórica (IFT), UAM/CSIC, Universidad Autonoma de Madrid, C/ Nicolás Cabrera 13-15, E-28049 Cantoblanco, Madrid (Spain); Hernández, Pilar; Mena, Olga [Instituto de Física Corpuscular (IFIC), CSIC-Universitat de València, Apartado de Correos 22085, E-46071 Valencia (Spain); Lattanzi, Massimiliano, E-mail: aaron.vincent@durham.ac.uk, E-mail: enrique.fernandez-martinez@uam.es, E-mail: m.pilar.hernandez@uv.es, E-mail: omena@ific.uv.es, E-mail: lattanzi@fe.infn.it [Dipartimento di Fisica e Science della Terra, Università di Ferrara and INFN, sezione di Ferrara, Polo Scientifico e Tecnologico, Edificio C Via Saragat, 1, I-44122 Ferrara (Italy)

    2015-04-01

    We employ state-of-the art cosmological observables including supernova surveys and BAO information to provide constraints on the mass and mixing angle of a non-resonantly produced sterile neutrino species, showing that cosmology can effectively rule out sterile neutrinos which decay between BBN and the present day. The decoupling of an additional heavy neutrino species can modify the time dependence of the Universe's expansion between BBN and recombination and, in extreme cases, lead to an additional matter-dominated period; while this could naively lead to a younger Universe with a larger Hubble parameter, it could later be compensated by the extra radiation expected in the form of neutrinos from sterile decay. However, recombination-era observables including the Cosmic Microwave Background (CMB), the shift parameter R{sub CMB} and the sound horizon r{sub s} from Baryon Acoustic Oscillations (BAO) severely constrain this scenario. We self-consistently include the full time-evolution of the coupled sterile neutrino and standard model sectors in an MCMC, showing that if decay occurs after BBN, the sterile neutrino is essentially bounded by the constraint sin{sup 2}θ ∼< 0.026 (m{sub s}/eV){sup −2}.

  17. Nonlinear delay monopoly with bounded rationality

    International Nuclear Information System (INIS)

    Matsumoto, Akio; Szidarovszky, Ferenc

    2012-01-01

    The purpose of this paper is to study the dynamics of a monopolistic firm in a continuous-time framework. The firm is assumed to be boundedly rational and to experience time delays in obtaining and implementing information on output. The dynamic adjustment process is based on the gradient of the expected profit. The paper is divided into three parts: we examine delay effects on dynamics caused by one-time delay and two-time delays in the first two parts. Global dynamics and analytical results on local dynamics are numerically confirmed in the third part. Four main results are demonstrated. First, the stability switch from stability to instability occurs only once in the case of a single delay. Second, the alternation of stability and instability can continue if two time delays are involved. Third, the occurence of Hopf bifurcation is analytically shown if stability is lost. Finally, in a bifurcation process, there are a period-doubling cascade to chaos and a period-halving cascade to the equilibrium point in the case of two time delays if the difference between the two delays is large.

  18. NITRO MUSK BOUND TO CARP HEMOGLOBIN ...

    Science.gov (United States)

    Nitroaromatic compounds including synthetic nitro musks are important raw materials and intermediates in the synthesis of explosives, dyes, and pesticides, pharmaceutical and personal care-products (PPCPs). The nitro musks such as musk xylene (MX) and musk ketone (MK) are extensively used as fragrance ingredients in PPCPs and other commercial toiletries. Identification and quantification of a bound 4-amino-MX (4-AMX) metabolite as well as a 2- amino-MK (2-AMK) metabolite were carried out by gas chromatography-mass spectrometry' (GC/MS), with selected ion monitoring (SIM) in both the electron ionization (ElMS) and electron capture (EC) negative ion chemical ionization (NICIMS) modes. Detection of 4-AMX and 2-AMK occurred after the cysteine adducts in carp hemoglobin, derived from the nitroso metabolites, were released by alkaline hydrolysis. The released metabolites were extracted into n-hexane. The extract was preconcentrated by evaporation, and analyzed by GC-SIM-MS. A comparison between the El and EC approaches was made. EC NICIMS detected both metabolites whereas only 4-AMX was detected by ElMS. The EC NICIMS approach exhibited fewer matrix responses and provided a lower detection limit. Quantitation in both approaches was based on internal standard and a calibration plot. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Q

  19. On the Hopping Efficiency of Nanoparticles in the Electron Transfer across Self‐Assembled Monolayers

    DEFF Research Database (Denmark)

    Liu, Feng; Khan, Kamran; Liang, Jing‐Hong

    2013-01-01

    Redox reactions of solvated molecular species at gold‐electrode surfaces modified by electrochemically inactive self‐assembled molecular monolayers (SAMs) are found to be activated by introducing Au nanoparticles (NPs) covalently bound to the SAM to form a reactive Au–alkanedithiol–NP–molecule hy...

  20. Charged boson bound states in the kerr-newman metric

    International Nuclear Information System (INIS)

    Li Yuanjie; Zhang Duanming

    1986-01-01

    Charged boson bound states in Kerr-Newman metric are discussed. It is found that massless boson cannot be attracted by Kerr-Newman black hole to form bound states. For the massive boson, the condition of the nonbound states when 0 2 - Q 2 and both the condition and wave functions of the bound states when a = √M 2 - Q 2 are obtained. The energy mode of the bound states is single, E = (m√M 2 - Q 2 + eQM)/(2M 2 - Q 2 ). When Q = 0 or e = 0, the conclusion is in agreement with that of Zhang Shiwei and Su Rukeng

  1. On the Applicability of Lower Bounds for Solving Rectilinear

    DEFF Research Database (Denmark)

    Clausen, Jens; Karisch, Stefan E.; Perregaard, M.

    1998-01-01

    . Recently, lower bounds based on decomposition were proposed for the so called rectilinear QAP that proved to be the strongest for a large class of problem instances. We investigate the strength of these bounds when applied not only at the root node of a search tree but as the bound function used......The quadratic assignment problem (QAP) belongs to the hard core of NP-hard optimization problems. After almost forty years of research only relatively small instances can be solved to optimality. The reason is that the quality of the lower bounds available for exact methods is not sufficient...

  2. Upper bounds on quantum uncertainty products and complexity measures

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero, Angel; Sanchez-Moreno, Pablo; Dehesa, Jesus S. [Department of Atomic, Molecular and Nuclear Physics, University of Granada, Granada (Spain); Department of Applied Mathematics, University of Granada, Granada (Spain) and Institute Carlos I for Computational and Theoretical Physics, University of Granada, Granada (Spain); Department of Atomic, Molecular and Nuclear Physics, University of Granada, Granada (Spain); Institute Carlos I for Computational and Theoretical Physics, University of Granada, Granada (Spain)

    2011-10-15

    The position-momentum Shannon and Renyi uncertainty products of general quantum systems are shown to be bounded not only from below (through the known uncertainty relations), but also from above in terms of the Heisenberg-Kennard product . Moreover, the Cramer-Rao, Fisher-Shannon, and Lopez-Ruiz, Mancini, and Calbet shape measures of complexity (whose lower bounds have been recently found) are also bounded from above. The improvement of these bounds for systems subject to spherically symmetric potentials is also explicitly given. Finally, applications to hydrogenic and oscillator-like systems are done.

  3. Twisting, supercoiling and stretching in protein bound DNA

    Science.gov (United States)

    Lam, Pui-Man; Zhen, Yi

    2018-04-01

    We have calculated theoretical results for the torque and slope of the twisted DNA, with various proteins bound on it, using the Neukirch-Marko model, in the regime where plectonemes exist. We found that the torque in the protein bound DNA decreases compared to that in the bare DNA. This is caused by the decrease in the free energy g(f) , and hence the smaller persistence lengths, in the case of protein bound DNA. We hope our results will encourage experimental investigations of supercoiling in protein bound DNA, which can provide further tests of the Neukirch-Marko model.

  4. Generalized Hofmann quantum process fidelity bounds for quantum filters

    Science.gov (United States)

    Sedlák, Michal; Fiurášek, Jaromír

    2016-04-01

    We propose and investigate bounds on the quantum process fidelity of quantum filters, i.e., probabilistic quantum operations represented by a single Kraus operator K . These bounds generalize the Hofmann bounds on the quantum process fidelity of unitary operations [H. F. Hofmann, Phys. Rev. Lett. 94, 160504 (2005), 10.1103/PhysRevLett.94.160504] and are based on probing the quantum filter with pure states forming two mutually unbiased bases. Determination of these bounds therefore requires far fewer measurements than full quantum process tomography. We find that it is particularly suitable to construct one of the probe bases from the right eigenstates of K , because in this case the bounds are tight in the sense that if the actual filter coincides with the ideal one, then both the lower and the upper bounds are equal to 1. We theoretically investigate the application of these bounds to a two-qubit optical quantum filter formed by the interference of two photons on a partially polarizing beam splitter. For an experimentally convenient choice of factorized input states and measurements we study the tightness of the bounds. We show that more stringent bounds can be obtained by more sophisticated processing of the data using convex optimization and we compare our methods for different choices of the input probe states.

  5. Bound entangled states violate a nonsymmetric local uncertainty relation

    International Nuclear Information System (INIS)

    Hofmann, Holger F.

    2003-01-01

    As a consequence of having a positive partial transpose, bound entangled states lack many of the properties otherwise associated with entanglement. It is therefore interesting to identify properties that distinguish bound entangled states from separable states. In this paper, it is shown that some bound entangled states violate a nonsymmetric class of local uncertainty relations [H. F. Hofmann and S. Takeuchi, Phys. Rev. A 68, 032103 (2003)]. This result indicates that the asymmetry of nonclassical correlations may be a characteristic feature of bound entanglement

  6. Classical Physics and the Bounds of Quantum Correlations.

    Science.gov (United States)

    Frustaglia, Diego; Baltanás, José P; Velázquez-Ahumada, María C; Fernández-Prieto, Armando; Lujambio, Aintzane; Losada, Vicente; Freire, Manuel J; Cabello, Adán

    2016-06-24

    A unifying principle explaining the numerical bounds of quantum correlations remains elusive, despite the efforts devoted to identifying it. Here, we show that these bounds are indeed not exclusive to quantum theory: for any abstract correlation scenario with compatible measurements, models based on classical waves produce probability distributions indistinguishable from those of quantum theory and, therefore, share the same bounds. We demonstrate this finding by implementing classical microwaves that propagate along meter-size transmission-line circuits and reproduce the probabilities of three emblematic quantum experiments. Our results show that the "quantum" bounds would also occur in a classical universe without quanta. The implications of this observation are discussed.

  7. Photophysics of aggregated 9-methylthiacarbocyanine bound to polyanions

    Science.gov (United States)

    Chibisov, Alexander K.; Görner, Helmut

    2002-05-01

    The photophysical properties of 3,3 '-diethyl-9-methylthiacarbocyanine (DTC) were studied in the presence of polystyrene sulfonate (PSS), polyacrylic acid (PAA) and polymethacrylic acid (PMA). The absorption spectra reflect a monomer/dimer equilibrium in neat aqueous solution and a shift towards bound H-aggregates, bound dimers and bound monomers on increasing the ratio of polyanion residue to dye concentrations ( r). These equilibria also determine the photodeactivation modes of DTC. The fluorescence intensity is reduced, when dimers and aggregates are present and strongly enhanced for low dye loading ( r=10 4). In contrast, the quantum yield of intersystem crossing is enhanced for bound dimers ( r=10 3).

  8. Nanoparticle albumin-bound (nab)-paclitaxel for the treatment of pancreas ductal adenocarcinoma

    OpenAIRE

    Weekes, Colin; Narayanan,Vignesh

    2015-01-01

    Vignesh Narayanan,1 Colin D Weekes1,2 1Division of Medical Oncology, Department of Medicine, 2Developmental Therapeutics Program, University of Colorado Cancer Center, University of Colorado School of Medicine, Aurora, CO, USA Abstract: Pancreatic adenocarcinoma is a leading cause of cancer-related mortality worldwide, and surgical resection offers the only chance of cure. Since the majority of patients have unresectable disease at presentation, the emphasis has been on identifying effective...

  9. [How safe are nanoparticles?].

    Science.gov (United States)

    Lademann, J; Meinke, M; Sterry, W; Patzelt, A

    2009-04-01

    Nanoparticles are experiencing an increasing application in dermatology and cosmetics. In both application areas, the requirements of nanoparticles are in most cases widely different. As a component of sunscreens, the nanoparticles are supposed to remain on the skin surface or in the upper most layers of the stratum corneum to protect the skin against UV-radiation of the sun. Whereas, on the other hand, when particulate substances are used as carrier systems for drugs, they have to cross the skin barrier to reach the target sites within the living tissue. We discuss the perspectives and risks of the topical application of nanoparticles.

  10. DETERMINATION OF A BOUND MUSK XYLENE ...

    Science.gov (United States)

    Musk xylene (MX) is widely used as a fragrance ingredient in commercial toiletries. Identification and quantification of a bound 4-amino-MX (AMX) metabolite was carried out by gas chromatography-mass spectrometry (GC/MS), with selected ion monitoring (SIM). Detection of AMX occurred after the cysteine adducts in carp hemoglobin, derived from the nitroso metabolite, were released by alkaline hydrolysis. The released AMX metabolite was extracted into n-hexane. The extract was preconcentrated by evaporation, and analyzed by GC-SIM-MS. The concentration of AMX metabolite was found to range from 6.0 to 30.6 ng/g in the carp Hb, collected from the Las Vegas Wash and Lake Mead, Nevada areas. The presence of an AMX metabolite in the carp Hb was confirmed when similar mass spectral features and the same retention time of the AMX metabolite were obtained for both standard AMX and carp Hb extract solutions. In the non-hydrolyzed and reagent blank extracts, the AMX metabolite was not detected. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers,

  11. Structure Biology of Membrane Bound Enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Dax [Johns Hopkins Univ., Baltimore, MD (United States). School of Medicine. Dept. of Physiology

    2016-11-30

    The overall goal of the proposed research is to understand the membrane-associated active processes catalyzed by an alkane $\\square$-hydroxylase (AlkB) from eubacterium Pseudomonase oleovorans. AlkB performs oxygenation of unactivated hydrocarbons found in crude oils. The enzymatic reaction involves energy-demanding steps in the membrane with the uses of structurally unknown metal active sites featuring a diiron [FeFe] center. At present, a critical barrier to understanding the membrane-associated reaction mechanism is the lack of structural information. The structural biology efforts have been challenged by technical difficulties commonly encountered in crystallization and structural determination of membrane proteins. The specific aims of the current budget cycle are to crystalize AlkB and initiate X-ray analysis to set the stage for structural determination. The long-term goals of our structural biology efforts are to provide an atomic description of AlkB structure, and to uncover the mechanisms of selective modification of hydrocarbons. The structural information will help elucidating how the unactivated C-H bonds of saturated hydrocarbons are oxidized to initiate biodegradation and biotransformation processes. The knowledge gained will be fundamental to biotechnological applications to biofuel transformation of non-edible oil feedstock. Renewable biodiesel is a promising energy carry that can be used to reduce fossil fuel dependency. The proposed research capitalizes on prior BES-supported efforts on over-expression and purification of AlkB to explore the inner workings of a bioenergy-relevant membrane-bound enzyme.

  12. Mechanism of the reduction of hexavalent chromium by organo-montmorillonite supported iron nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Pingxiao, E-mail: pppxwu@scut.edu.cn [College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006 (China); Li, Shuzhen [School of Chemical and Environmental Engineering, Wuyi University, Jiangmen, Guangdong Province 529020 (China); Ju, Liting [College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006 (China); Zhu, Nengwu [College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006 (China); The Key Laboratory of Environmental Protection and Eco-Remediation of Guangdong Regular Higher Education Institutions (China); Wu, Jinhua; Li, Ping [College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006 (China); Dang, Zhi [College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006 (China); The Key Laboratory of Environmental Protection and Eco-Remediation of Guangdong Regular Higher Education Institutions (China)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Organo-montmorillonite supported iron nanoparticles were found to be more efficient in the removal of Cr(VI) than unsupported iron nanoparticles. Black-Right-Pointing-Pointer The iron nanoparticles were accommodated by the sectional structure of the clay minerals which were helpful to protect the nanoparticles from aggregating. Black-Right-Pointing-Pointer XPS and XANES provided some direct information about the reduction mechanisms. Black-Right-Pointing-Pointer The structure of the supported iron nanoparticles was stable in the reaction with Cr(VI). - Abstract: Iron nanoparticles exhibit greater reactivity than micro-sized Fe{sup 0}, and they impart advantages for groundwater remediation. In this paper, supported iron nanoparticles were synthesized to further enhance the speed and efficiency of remediation. Natural montmorillonite and organo-montmorillonite were chosen as supporting materials. The capacity of supported iron nanoparticles was evaluated, compared to unsupported iron nanoparticles, for the reduction of aqueous Cr(VI). The reduction of Cr(VI) was much greater with organo-montmorillonite supported iron nanoparticles and fitted the pseudo-second order equation better. With a dose at 0.47 g/L, a total removal capacity of 106 mg Cr/g Fe{sup 0} was obtained. Other factors that affect the efficiency of Cr(VI) removal, such as pH values, the initial Cr(VI) concentration and storage time of nanoparticles were investigated. X-ray photoelectron spectrometry (XPS) and X-ray absorption near edge structure (XANES) were used to figure out the mechanism of the removal of Cr(VI). XPS indicated that the Cr(VI) bound to the particle surface was completely reduced to Cr(III) under a range of conditions. XANES confirmed that the Cr(VI) reacted with iron nanoparticles was completely reduced to Cr(III).

  13. Mechanism of the reduction of hexavalent chromium by organo-montmorillonite supported iron nanoparticles

    International Nuclear Information System (INIS)

    Wu, Pingxiao; Li, Shuzhen; Ju, Liting; Zhu, Nengwu; Wu, Jinhua; Li, Ping; Dang, Zhi

    2012-01-01

    Highlights: ► Organo-montmorillonite supported iron nanoparticles were found to be more efficient in the removal of Cr(VI) than unsupported iron nanoparticles. ► The iron nanoparticles were accommodated by the sectional structure of the clay minerals which were helpful to protect the nanoparticles from aggregating. ► XPS and XANES provided some direct information about the reduction mechanisms. ► The structure of the supported iron nanoparticles was stable in the reaction with Cr(VI). - Abstract: Iron nanoparticles exhibit greater reactivity than micro-sized Fe 0 , and they impart advantages for groundwater remediation. In this paper, supported iron nanoparticles were synthesized to further enhance the speed and efficiency of remediation. Natural montmorillonite and organo-montmorillonite were chosen as supporting materials. The capacity of supported iron nanoparticles was evaluated, compared to unsupported iron nanoparticles, for the reduction of aqueous Cr(VI). The reduction of Cr(VI) was much greater with organo-montmorillonite supported iron nanoparticles and fitted the pseudo-second order equation better. With a dose at 0.47 g/L, a total removal capacity of 106 mg Cr/g Fe 0 was obtained. Other factors that affect the efficiency of Cr(VI) removal, such as pH values, the initial Cr(VI) concentration and storage time of nanoparticles were investigated. X-ray photoelectron spectrometry (XPS) and X-ray absorption near edge structure (XANES) were used to figure out the mechanism of the removal of Cr(VI). XPS indicated that the Cr(VI) bound to the particle surface was completely reduced to Cr(III) under a range of conditions. XANES confirmed that the Cr(VI) reacted with iron nanoparticles was completely reduced to Cr(III).

  14. One-Dimensional Brownian Motion of Charged Nanoparticles along Microtubules: A Model System for Weak Binding Interactions

    OpenAIRE

    Minoura, Itsushi; Katayama, Eisaku; Sekimoto, Ken; Muto, Etsuko

    2010-01-01

    Various proteins are known to exhibit one-dimensional Brownian motion along charged rodlike polymers, such as microtubules (MTs), actin, and DNA. The electrostatic interaction between the proteins and the rodlike polymers appears to be crucial for one-dimensional Brownian motion, although the underlying mechanism has not been fully clarified. We examined the interactions of positively-charged nanoparticles composed of polyacrylamide gels with MTs. These hydrophilic nanoparticles bound to MTs ...

  15. Encapsulation of gold nanoparticles into self-assembling protein nanoparticles

    OpenAIRE

    Yang Yongkun; Burkhard Peter

    2012-01-01

    Abstract Background Gold nanoparticles are useful tools for biological applications due to their attractive physical and chemical properties. Their applications can be further expanded when they are functionalized with biological molecules. The biological molecules not only provide the interfaces for interactions between nanoparticles and biological environment, but also contribute their biological functions to the nanoparticles. Therefore, we used self-assembling protein nanoparticles (SAPNs...

  16. Dark-matter bound states from Feynman diagrams

    NARCIS (Netherlands)

    Petraki, K.; Postma, M.; Wiechers, M.

    2015-01-01

    If dark matter couples directly to a light force mediator, then it may form bound states in the early universe and in the non-relativistic environment of haloes today. In this work, we establish a field-theoretic framework for the computation of bound-state formation cross-sections, de-excitation

  17. Bounds on the Effect of Progressive Structural Degradation

    DEFF Research Database (Denmark)

    Achtziger, Wolfgang; Bendsøe, Martin P; Taylor, John E.

    1997-01-01

    Problem formulations are presented for the evaluation of upper and lower bounds on the effect of progressive structural degradation. For the purposes of this study, degradation effect is measured by an increase in global structural compliance (flexibility). Thus the stated bounds are given simply...

  18. Models and Techniques for Proving Data Structure Lower Bounds

    DEFF Research Database (Denmark)

    Larsen, Kasper Green

    In this dissertation, we present a number of new techniques and tools for proving lower bounds on the operational time of data structures. These techniques provide new lines of attack for proving lower bounds in both the cell probe model, the group model, the pointer machine model and the I...... bound of tutq = (lgd􀀀1 n). For ball range searching, we get a lower bound of tutq = (n1􀀀1=d). The highest previous lower bound proved in the group model does not exceed ((lg n= lg lg n)2) on the maximum of tu and tq. Finally, we present a new technique for proving lower bounds....../O-model. In all cases, we push the frontiers further by proving lower bounds higher than what could possibly be proved using previously known techniques. For the cell probe model, our results have the following consequences: The rst (lg n) query time lower bound for linear space static data structures...

  19. Bounds for Tail Probabilities of the Sample Variance

    Directory of Open Access Journals (Sweden)

    Van Zuijlen M

    2009-01-01

    Full Text Available We provide bounds for tail probabilities of the sample variance. The bounds are expressed in terms of Hoeffding functions and are the sharpest known. They are designed having in mind applications in auditing as well as in processing data related to environment.

  20. Entropy Bounds for Constrained Two-Dimensional Fields

    DEFF Research Database (Denmark)

    Forchhammer, Søren Otto; Justesen, Jørn

    1999-01-01

    The maximum entropy and thereby the capacity of 2-D fields given by certain constraints on configurations are considered. Upper and lower bounds are derived.......The maximum entropy and thereby the capacity of 2-D fields given by certain constraints on configurations are considered. Upper and lower bounds are derived....

  1. Optimal Two Parameter Bounds for the Seiffert Mean

    Directory of Open Access Journals (Sweden)

    Hui Sun

    2013-01-01

    Full Text Available We obtain sharp bounds for the Seiffert mean in terms of a two parameter family of means. Our results generalize and extend the recent bounds presented in the Journal of Inequalities and Applications (2012 and Abstract and Applied Analysis (2012.

  2. The question of an upper bound on entropy

    International Nuclear Information System (INIS)

    Qadir, A.

    1982-08-01

    We discuss the possibility, and significance, of an upper bound on entropy in the light of the arguments of Bekenstein and Unruh and Wald. We obtain a stricter bound than Bekenstein does, and point out some limitations with regard to its significance. (author)

  3. Bounds on the Effect of Progressive Structural Degradation

    DEFF Research Database (Denmark)

    Achtziger, W.; Bendsøe, Martin P; Taylor, John E.

    1998-01-01

    Problem formulations are presented for the evaluation of upper and lower bounds on the effect of progressive structural degradation. For the purposes of this study, degradation effect is measured by an increase in global structural compliance (flexibility). Thus the slated bounds are given simply...

  4. Bounds of Certain Dynamic Inequalities on Time Scales

    Directory of Open Access Journals (Sweden)

    Deepak B. Pachpatte

    2014-10-01

    Full Text Available In this paper we study explicit bounds of certain dynamic integral inequalities on time scales. These estimates give the bounds on unknown functions which can be used in studying the qualitative aspects of certain dynamic equations. Using these inequalities we prove the uniqueness of some partial integro-differential equations on time scales.

  5. Dielectric structures with bound modes for microcavity lasers

    NARCIS (Netherlands)

    Visser, P.M.; Allaart, K.; Lenstra, D.

    2002-01-01

    Cavity modes of dielectric microsphcres and vertical cavity surface emitting lasers, in spite of their high Q, are never exactly bound, but have a finite width due to leakage at the borders. We propose types of microstructures that sustain three-dimensionally bound modes of the radiation field when

  6. Solving the minimum flow problem with interval bounds and flows

    Indian Academy of Sciences (India)

    ... with crisp data. In this paper, the idea of Ghiyasvand was extended for solving the minimum flow problem with interval-valued lower, upper bounds and flows. This problem can be solved using two minimum flow problems with crisp data. Then, this result is extended to networks with fuzzy lower, upper bounds and flows.

  7. A tail bound for read-k families of functions

    Czech Academy of Sciences Publication Activity Database

    Gavinsky, Dmitry; Lovett, S.; Saks, M.; Srinivasan, S.

    2015-01-01

    Roč. 47, č. 1 (2015), s. 99-108 ISSN 1042-9832 Institutional support: RVO:67985840 Keywords : tail bound * deviation bound * random variables Subject RIV: BA - General Mathematics Impact factor: 1.011, year: 2015 http://onlinelibrary.wiley.com/doi/10.1002/ rsa .20532/abstract

  8. Bounds on charged lepton mixing with exotic charged leptons Ф

    Indian Academy of Sciences (India)

    imposing the constraints that the amplitude should not exceed the perturbative unitarity limit at high energy (. Ф. × = A), we obtain bounds on light heavy charged lepton mixing parameter sin. 2. (2 a. L) where a. L is the mixing angle of the ordinary charged lepton with its exotic partner. For A = 1 TeV, no bound is obtained on ...

  9. Holographic bounds on the UV cutoff scale in inflationary cosmology

    DEFF Research Database (Denmark)

    Keski-Vakkuri, Esko; Sloth, Martin Snoager

    2003-01-01

    We discuss how holographic bounds can be applied to the quantum fluctuations of the inflaton. In general the holographic principle will lead to a bound on the UV cutoff scale of the effective theory of inflation, but it will depend on the coarse-graining prescription involved in calculating...

  10. Supergravity and upper bound on scale of supersymmetry breaking

    International Nuclear Information System (INIS)

    Kim, J.E.; Nishino, H.

    1983-09-01

    In locally supersymmetric grand unified models we show rather a model independent upper bound 3x10 11 GeV for the scale of supersymmetry breaking, which is derived by considering SU(2)xU(1) breaking at electro-weak mass scale. This bound necessarily implies the existence of new particles (superpartners) below 10 4 GeV. (author)

  11. A Partitioning and Bounded Variable Algorithm for Linear Programming

    Science.gov (United States)

    Sheskin, Theodore J.

    2006-01-01

    An interesting new partitioning and bounded variable algorithm (PBVA) is proposed for solving linear programming problems. The PBVA is a variant of the simplex algorithm which uses a modified form of the simplex method followed by the dual simplex method for bounded variables. In contrast to the two-phase method and the big M method, the PBVA does…

  12. The linear programming bound for binary linear codes

    NARCIS (Netherlands)

    Brouwer, A.E.

    1993-01-01

    Combining Delsarte's (1973) linear programming bound with the information that certain weights cannot occur, new upper bounds for dmin (n,k), the maximum possible minimum distance of a binary linear code with given word length n and dimension k, are derived.

  13. Monetary and fiscal policy under bounded rationality and heterogeneous expectations

    NARCIS (Netherlands)

    Lustenhouwer, J.E.

    2017-01-01

    The goal of this thesis is to use plausible and intuitive models of bounded rationality to give new insights in monetary and fiscal policy. Particular focus is put on the zero lower bound on the nominal interest rate, forward guidance, and fiscal consolidations. The thesis considers different forms

  14. Towards an abstract parallel branch and bound machine

    NARCIS (Netherlands)

    A. de Bruin (Arie); G.A.P. Kindervater (Gerard); H.W.J.M. Trienekens

    1995-01-01

    textabstractMany (parallel) branch and bound algorithms look very different from each other at first glance. They exploit, however, the same underlying computational model. This phenomenon can be used to define branch and bound algorithms in terms of a set of basic rules that are applied in a

  15. A geometric bound on F-term inflation

    NARCIS (Netherlands)

    Borghese, Andrea; Roest, Diederik; Zavala, Ivonne

    We discuss a general bound on the possibility to realise inflation in any minimal supergravity with F-terms. The derivation crucially depends on the sGoldstini, the scalar field directions that are singled out by spontaneous supersymmetry breaking. The resulting bound involves both slow-roll

  16. Relativistic bound states: a mass formula for vector mesons

    International Nuclear Information System (INIS)

    Richard, J.L.; Sorba, P.

    1975-07-01

    In the framework of a relativistic description of two particles bound states, a mass formula for vector mesons considered as quark-antiquark systems bound by harmonic oscillator like forces is proposed. Results in good agreement with experimental values are obtained [fr

  17. A tail bound for read-k families of functions

    Czech Academy of Sciences Publication Activity Database

    Gavinsky, Dmitry; Lovett, S.; Saks, M.; Srinivasan, S.

    2015-01-01

    Roč. 47, č. 1 (2015), s. 99-108 ISSN 1042-9832 Institutional support: RVO:67985840 Keywords : tail bound * deviation bound * random variables Subject RIV: BA - General Mathematics Impact factor: 1.011, year: 2015 http://onlinelibrary.wiley.com/doi/10.1002/rsa.20532/abstract

  18. Extrinsic Isoperimetric Analysis on Submanifolds with Curvatures bounded from below

    DEFF Research Database (Denmark)

    Markvorsen, Steen; Palmer, Vicente

    2010-01-01

    and on the radial part of the intrinsic unit normals at the boundaries of the extrinsic spheres, respectively. In the same vein we also establish lower bounds on the mean exit time for Brownian motions in the extrinsic balls, i.e. lower bounds for the time it takes (on average) for Brownian particles to diffuse......We obtain upper bounds for the isoperimetric quotients of extrinsic balls of submanifolds in ambient spaces which have a lower bound on their radial sectional curvatures. The submanifolds are themselves only assumed to have lower bounds on the radial part of the mean curvature vector field...... within the extrinsic ball from a given starting point before they hit the boundary of the extrinsic ball. In those cases, where we may extend our analysis to hold all the way to infinity, we apply a capacity comparison technique to obtain a sufficient condition for the submanifolds to be parabolic, i...

  19. Amos-type bounds for modified Bessel function ratios☆

    Science.gov (United States)

    Hornik, Kurt; Grün, Bettina

    2013-01-01

    We systematically investigate lower and upper bounds for the modified Bessel function ratio Rν=Iν+1/Iν by functions of the form Gα,β(t)=t/(α+t2+β2) in case Rν is positive for all t>0, or equivalently, where ν≥−1 or ν is a negative integer. For ν≥−1, we give an explicit description of the set of lower bounds and show that it has a greatest element. We also characterize the set of upper bounds and its minimal elements. If ν≥−1/2, the minimal elements are tangent to Rν in exactly one point 0≤t≤∞, and have Rν as their lower envelope. We also provide a new family of explicitly computable upper bounds. Finally, if ν is a negative integer, we explicitly describe the sets of lower and upper bounds, and give their greatest and least elements, respectively. PMID:24926105

  20. Amos-type bounds for modified Bessel function ratios.

    Science.gov (United States)

    Hornik, Kurt; Grün, Bettina

    2013-12-01

    We systematically investigate lower and upper bounds for the modified Bessel function ratio [Formula: see text] by functions of the form [Formula: see text] in case [Formula: see text] is positive for all [Formula: see text], or equivalently, where [Formula: see text] or [Formula: see text] is a negative integer. For [Formula: see text], we give an explicit description of the set of lower bounds and show that it has a greatest element. We also characterize the set of upper bounds and its minimal elements. If [Formula: see text], the minimal elements are tangent to [Formula: see text] in exactly one point [Formula: see text], and have [Formula: see text] as their lower envelope. We also provide a new family of explicitly computable upper bounds. Finally, if [Formula: see text] is a negative integer, we explicitly describe the sets of lower and upper bounds, and give their greatest and least elements, respectively.

  1. Lower Bounds to the Reliabilities of Factor Score Estimators.

    Science.gov (United States)

    Hessen, David J

    2016-10-06

    Under the general common factor model, the reliabilities of factor score estimators might be of more interest than the reliability of the total score (the unweighted sum of item scores). In this paper, lower bounds to the reliabilities of Thurstone's factor score estimators, Bartlett's factor score estimators, and McDonald's factor score estimators are derived and conditions are given under which these lower bounds are equal. The relative performance of the derived lower bounds is studied using classic example data sets. The results show that estimates of the lower bounds to the reliabilities of Thurstone's factor score estimators are greater than or equal to the estimates of the lower bounds to the reliabilities of Bartlett's and McDonald's factor score estimators.

  2. Proximity effect tunneling into virtual bound state alloys

    International Nuclear Information System (INIS)

    Tang, I.M.; Roongkkeadsakoon, S.

    1984-01-01

    The effects of a narrow virtual bound state formed by transition metal impurities dissolved in the normal layer of a superconducting proximity effect sandwich are studied. Using standard renormalization techniques, we obtain the changes in the transition temperatures and the jumps in the specific heat at T/sub c/ as a function of the thickness of the normal layer, of the widths of the virtual bound states, and of the impurity concentrations. It is seen that narrow virtual bound states lead to decrease in the transition temperatures, while broad virtual bound states do not. It if further seen that the narrow virtual bound state causes the reduced specific heat jump at T/sub c/ to deviate from the BCS behavior expected of the pure sandwich

  3. Viscosity bound violation in holographic solids and the viscoelastic response

    Energy Technology Data Exchange (ETDEWEB)

    Alberte, Lasma [Abdus Salam International Centre for Theoretical Physics (ICTP),Strada Costiera 11, 34151, Trieste (Italy); Baggioli, Matteo [Institut de Física d’Altes Energies (IFAE),The Barcelona Institute of Science and Technology (BIST),Campus UAB, 08193 Bellaterra, Barcelona (Spain); Department of Physics, Institute for Condensed Matter Theory, University of Illinois,1110 W. Green Street, Urbana, IL 61801 (United States); Pujolàs, Oriol [Institut de Física d’Altes Energies (IFAE),The Barcelona Institute of Science and Technology (BIST),Campus UAB, 08193 Bellaterra, Barcelona (Spain)

    2016-07-14

    We argue that the Kovtun-Son-Starinets (KSS) lower bound on the viscosity to entropy density ratio holds in fluid systems but is violated in solid materials with a non-zero shear elastic modulus. We construct explicit examples of this by applying the standard gauge/gravity duality methods to massive gravity and show that the KSS bound is clearly violated in black brane solutions whenever the massive gravity theories are of solid type. We argue that the physical reason for the bound violation relies on the viscoelastic nature of the mechanical response in these materials. We speculate on whether any real-world materials can violate the bound and discuss a possible generalization of the bound that involves the ratio of the shear elastic modulus to the pressure.

  4. Viscosity bound violation in holographic solids and the viscoelastic response

    International Nuclear Information System (INIS)

    Alberte, Lasma; Baggioli, Matteo; Pujolàs, Oriol

    2016-01-01

    We argue that the Kovtun-Son-Starinets (KSS) lower bound on the viscosity to entropy density ratio holds in fluid systems but is violated in solid materials with a non-zero shear elastic modulus. We construct explicit examples of this by applying the standard gauge/gravity duality methods to massive gravity and show that the KSS bound is clearly violated in black brane solutions whenever the massive gravity theories are of solid type. We argue that the physical reason for the bound violation relies on the viscoelastic nature of the mechanical response in these materials. We speculate on whether any real-world materials can violate the bound and discuss a possible generalization of the bound that involves the ratio of the shear elastic modulus to the pressure.

  5. Bounds and estimates for the linearly perturbed eigenvalue problem

    International Nuclear Information System (INIS)

    Raddatz, W.D.

    1983-01-01

    This thesis considers the problem of bounding and estimating the discrete portion of the spectrum of a linearly perturbed self-adjoint operator, M(x). It is supposed that one knows an incomplete set of data consisting in the first few coefficients of the Taylor series expansions of one or more of the eigenvalues of M(x) about x = 0. The foundations of the variational study of eigen-values are first presented. These are then used to construct the best possible upper bounds and estimates using various sets of given information. Lower bounds are obtained by estimating the error in the upper bounds. The extension of these bounds and estimates to the eigenvalues of the doubly-perturbed operator M(x,y) is discussed. The results presented have numerous practical application in the physical sciences, including problems in atomic physics and the theory of vibrations of acoustical and mechanical systems

  6. Evacuation of Bed-bound Patients-STEPS Simulations

    DEFF Research Database (Denmark)

    Madsen, Anne; Dederichs, Anne Simone

    2016-01-01

    Fires in hospitals occur, and evacuation of bed-bound patients might be necessary in case of emergency. The current study concerns the evacuation of bed-bound patients from a fire section in a hospital using hospital porters. The simulations are performed using the STEPS program. The aim...... of the study is to investigate the evacuation time of bed-bound hospital patients using different walking speeds from the literature, and the influence of the number of hospital porters on the total evacuation times of bed-bound patients. Different scenarios were carried out with varying staff......-to-patient ratios that simulate the horizontal evacuation of 40 bed-bound patients into a different fire section. It was found that the staff-to-patient-ratio affects the total evacuation times. However, the total evacuation times do not decrease linearly and a saturation effect is seen at a staff-to-patient ratio...

  7. Quantum engine efficiency bound beyond the second law of thermodynamics.

    Science.gov (United States)

    Niedenzu, Wolfgang; Mukherjee, Victor; Ghosh, Arnab; Kofman, Abraham G; Kurizki, Gershon

    2018-01-11

    According to the second law, the efficiency of cyclic heat engines is limited by the Carnot bound that is attained by engines that operate between two thermal baths under the reversibility condition whereby the total entropy does not increase. Quantum engines operating between a thermal and a squeezed-thermal bath have been shown to surpass this bound. Yet, their maximum efficiency cannot be determined by the reversibility condition, which may yield an unachievable efficiency bound above unity. Here we identify the fraction of the exchanged energy between a quantum system and a bath that necessarily causes an entropy change and derive an inequality for this change. This inequality reveals an efficiency bound for quantum engines energised by a non-thermal bath. This bound does not imply reversibility, unless the two baths are thermal. It cannot be solely deduced from the laws of thermodynamics.

  8. Biosynthesis of silver nanoparticles

    African Journals Online (AJOL)

    SIMBU

    2013-05-22

    May 22, 2013 ... accomplish a better control over the size and shape distributions of the nanoparticles, product harvesting, and recovery are ... stabilization of various nanoparticles by physical and che- .... colonies on Luria Bertani (LB) medium at 37°C up to 108- ..... Crude latex was obtained by cutting the green stems of J.

  9. Optical properties of nanoparticles

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    At the NBI I am involved in projects relating to optical properties of metallic nanoparticles in particular with respect to plasmonic heating with direct applications to photothermal cancer therapy. For this purpose we have developed heating assays that can be used to measure the heating of any...... nanoscopic heat source like an irradiated nanoparticle...

  10. Interaction of ZnS nanoparticles with flavins and glucose oxidase: A fluorimetric investigation

    International Nuclear Information System (INIS)

    Chatterjee, Anindita; Priyam, Amiya; Ghosh, Debasmita; Mondal, Somrita; Bhattacharya, Subhash C.; Saha, Abhijit

    2012-01-01

    Interactions of luminescence, water soluble ZnS nanoparticles (NPs) with flavins and glucose oxidase have been thoroughly investigated through optical spectroscopy. The photoluminescence of ZnS nanoparticles was quenched severely (∼60%) by riboflavin while other flavins such as flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) show quenching to different extents under analogous conditions. However, interestingly no effect in luminescence intensity of ZnS NPs was observed with protein bound flavins such as in glucose oxidase. Fluorescence lifetime measurement confirmed the quenching to be static in nature. Scavenging of photo-generated electron of ZnS nanoparticles by the flavin molecules may be attributed to the decrease in luminescence intensity. Quenching of ZnS nanoparticles with flavins follows the linear Stern–Volmer plot. The Stern–Volmer constants decreased in the following order: K S−V (Riboflavin)> K S−V (FAD)> K S−V (FMN). This interaction study could generate useful protocol for the fluorimetric determination of riboflavin (vitamin B 2 ) content and also riboflavin status in biological systems. - Highlights: ► Unique interaction specificity of ZnS nanoparticles with flavins has been explored. ► Unlike protein-bound flavin, fluorescence of free flavins was quenched by ZnS nanoparticles. ► FMN and FAD show quenching to different extents under analogous conditions. ► Fluorescence lifetime measurement confirmed the quenching to be static in nature. ► This study is useful for probing riboflavin in biological systems.

  11. Single Nanoparticle Plasmonic Sensors

    Directory of Open Access Journals (Sweden)

    Manish Sriram

    2015-10-01

    Full Text Available The adoption of plasmonic nanomaterials in optical sensors, coupled with the advances in detection techniques, has opened the way for biosensing with single plasmonic particles. Single nanoparticle sensors offer the potential to analyse biochemical interactions at a single-molecule level, thereby allowing us to capture even more information than ensemble measurements. We introduce the concepts behind single nanoparticle sensing and how the localised surface plasmon resonances of these nanoparticles are dependent upon their materials, shape and size. Then we outline the different synthetic approaches, like citrate reduction, seed-mediated and seedless growth, that enable the synthesis of gold and silver nanospheres, nanorods, nanostars, nanoprisms and other nanostructures with tunable sizes. Further, we go into the aspects related to purification and functionalisation of nanoparticles, prior to the fabrication of sensing surfaces. Finally, the recent developments in single nanoparticle detection, spectroscopy and sensing applications are discussed.

  12. Energy breathing of nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Dynich, Raman A., E-mail: dynich@solo.by [Institute of Social Educational Technologies (Belarus)

    2015-06-15

    The paper considers the energy exchange process of the electromagnetic wave with a spherical metal nanoparticle. Based on the account of the temporal dependencies of electric and magnetic fields, the author presents an analytical dependence of the energy flow passing through the spherical surface. It is shown that the electromagnetic energy, localized in metal nanoparticles, is not a stationary value and periodically varies with time. A consequence of the energy nonstationarity is a nonradiating exit of the electromagnetic energy out of the nanoparticle. During the time equal to the period of wave oscillations, the electromagnetic energy is penetrating twice into the particle and quits it twice. The particle warms up because of the difference in the incoming and outgoing energies. Such “energy breathing” is presented for spherical Ag and Au nanoparticles with radii of 10 and 33 nm, respectively. Calculations were conducted for these nanoparticles embedded into the cell cytoplasm near the frequencies of their surface plasmon resonances.

  13. Magnetic interactions between nanoparticles

    DEFF Research Database (Denmark)

    Mørup, Steen; Hansen, Mikkel Fougt; Frandsen, Cathrine

    2010-01-01

    We present a short overview of the influence of inter-particle interactions on the properties of magnetic nanoparticles. Strong magnetic dipole interactions between ferromagnetic or ferrimagnetic particles, that would be superparamagnetic if isolated, can result in a collective state...... of nanoparticles. This collective state has many similarities to spin-glasses. In samples of aggregated magnetic nanoparticles, exchange interactions are often important and this can also lead to a strong suppression of superparamagnetic relaxation. The temperature dependence of the order parameter in samples...... of strongly interacting hematite nanoparticles or goethite grains is well described by a simple mean field model. Exchange interactions between nanoparticles with different orientations of the easy axes can also result in a rotation of the sub-lattice magnetization directions....

  14. Magnetic nanoparticles in magnetic resonance imaging and diagnostics.

    Science.gov (United States)

    Rümenapp, Christine; Gleich, Bernhard; Haase, Axel

    2012-05-01

    Magnetic nanoparticles are useful as contrast agents for magnetic resonance imaging (MRI). Paramagnetic contrast agents have been used for a long time, but more recently superparamagnetic iron oxide nanoparticles (SPIOs) have been discovered to influence MRI contrast as well. In contrast to paramagnetic contrast agents, SPIOs can be functionalized and size-tailored in order to adapt to various kinds of soft tissues. Although both types of contrast agents have a inducible magnetization, their mechanisms of influence on spin-spin and spin-lattice relaxation of protons are different. A special emphasis on the basic magnetism of nanoparticles and their structures as well as on the principle of nuclear magnetic resonance is made. Examples of different contrast-enhanced magnetic resonance images are given. The potential use of magnetic nanoparticles as diagnostic tracers is explored. Additionally, SPIOs can be used in diagnostic magnetic resonance, since the spin relaxation time of water protons differs, whether magnetic nanoparticles are bound to a target or not.

  15. Biological Mechanism of Silver Nanoparticle Toxicity

    Science.gov (United States)

    Armstrong, Najealicka Nicole

    Silver nanoparticles (AgNPs), like almost all nanoparticles, are potentially toxic beyond a certain concentration because the survival of the organism is compromised due to scores of pathophysiological abnormalities above that concentration. However, the mechanism of AgNP toxicity remains undetermined. Instead of applying a toxic dose, these investigations were attempted to monitor the effects of AgNPs at a non-lethal concentration on wild type Drosophila melanogaster by exposing them to nanoparticles throughout their development. All adult flies raised in AgNP doped food indicated that of not more than 50 mg/L had no negative influence on median survival; however, these flies appeared uniformly lighter in body color due to the loss of melanin pigments in their cuticle. Additionally, fertility and vertical movement ability were compromised after AgNP feeding. The determination of the amount of free ionic silver (Ag+) indicated that the observed biological effects had resulted from the AgNPs and not from Ag+. Biochemical analysis suggests that the activity of copper dependent enzymes, namely tyrosinase and Cu-Zn superoxide dismutase, were decreased significantly following the consumption of AgNPs, despite the constant level of copper present in the tissue. Furthermore, copper supplementation restored the loss of AgNP induced demelanization, and the reduction of functional Ctr1 in Ctr1 heterozygous mutants caused the flies to be resistant to demelanization. Consequently, these studies proposed a mechanism whereby consumption of excess AgNPs in association with membrane bound copper transporter proteins cause sequestration of copper, thus creating a condition that resembles copper starvation. This model also explained the cuticular demelanization effect resulting from AgNP since tyrosinase activity is essential for melanin biosynthesis. Finally, these investigations demonstrated that Drosophila, an established genetic model system, can be well utilized for further

  16. Functional Magnetic Nanoparticles

    Science.gov (United States)

    Gass, James

    Nanoparticle system research and characterization is the focal point of this research and dissertation. In the research presented here, magnetite, cobalt, and ferrite nanoparticle systems have been explored in regard to their magnetocaloric effect (MCE) properties, as well as for use in polymer composites. Both areas of study have potential applications across a wide variety of interdisciplinary fields. Magnetite nanoparticles have been successfully dispersed in a polymer. The surface chemistry of the magnetic nanoparticle proves critical to obtaining a homogenous and well separated high density dispersion in PMMA. Theoretical studies found in the literature have indicated that surface interface energy is a critical component in dispersion. Oleic acid is used to alter the surface of magnetite nanoparticles and successfully achieve good dispersion in a PMMA thin film. Polypyrrole is then coated onto the PMMA composite layer. The bilayer is characterized using cross-sectional TEM, cross-sectional SEM, magnetic characterization, and low frequency conductivity. The results show that the superparmagnetic properties of the as synthesized particles are maintained in the composite. With further study of the properties of these nanoparticles for real and functional uses, MCE is studied on a variety of magnetic nanoparticle systems. Magnetite, manganese zinc ferrite, and cobalt ferrite systems show significant broadening of the MCE and the ability to tune the peak temperature of MCE by varying the size of the nanoparticles. Four distinct systems are studied including cobalt, cobalt core silver shell nanoparticles, nickel ferrite, and ball milled zinc ferrite. The results demonstrate the importance of surface characteristics on MCE. Surface spin disorder appears to have a large influence on the low temperature magnetic and magnetocalorie characteristics of these nanoparticle systems.

  17. Green synthesis of gold and silver nanoparticles using Hibiscus rosa sinensis

    Science.gov (United States)

    Philip, Daizy

    2010-03-01

    Biological synthesis of gold and silver nanoparticles of various shapes using the leaf extract of Hibiscus rosa sinensis is reported. This is a simple, cost-effective, stable for long time and reproducible aqueous room temperature synthesis method to obtain a self-assembly of Au and Ag nanoparticles. The size and shape of Au nanoparticles are modulated by varying the ratio of metal salt and extract in the reaction medium. Variation of pH of the reaction medium gives silver nanoparticles of different shapes. The nanoparticles obtained are characterized by UV-vis, transmission electron microscopy (TEM), X-ray diffraction (XRD) and FTIR spectroscopy. Crystalline nature of the nanoparticles in the fcc structure are confirmed by the peaks in the XRD pattern corresponding to (1 1 1), (2 0 0), (2 2 0) and (3 1 1) planes, bright circular spots in the selected area electron diffraction (SAED) and clear lattice fringes in the high-resolution TEM image. From FTIR spectra it is found that the Au nanoparticles are bound to amine groups and the Ag nanoparticles to carboxylate ion groups.

  18. Aluminum stimulates uptake of non-transferrin bound iron and transferrin bound iron in human glial cells

    International Nuclear Information System (INIS)

    Kim, Yongbae; Olivi, Luisa; Cheong, Jae Hoon; Maertens, Alex; Bressler, Joseph P.

    2007-01-01

    Aluminum and other trivalent metals were shown to stimulate uptake of transferrin bound iron and nontransferrin bound iron in erytholeukemia and hepatoma cells. Because of the association between aluminum and Alzheimer's Disease, and findings of higher levels of iron in Alzheimer's disease brains, the effects of aluminum on iron homeostasis were examined in a human glial cell line. Aluminum stimulated dose- and time-dependent uptake of nontransferrin bound iron and iron bound to transferrin. A transporter was likely involved in the uptake of nontransferrin iron because uptake reached saturation, was temperature-dependent, and attenuated by inhibitors of protein synthesis. Interestingly, the effects of aluminum were not blocked by inhibitors of RNA synthesis. Aluminum also decreased the amount of iron bound to ferritin though it did not affect levels of divalent metal transporter 1. These results suggest that aluminum disrupts iron homeostasis in Brain by several mechanisms including the transferrin receptor, a nontransferrin iron transporter, and ferritin

  19. Microemulsion Synthesis of Nanoparticles

    Directory of Open Access Journals (Sweden)

    Gotić, M.

    2013-11-01

    Full Text Available Nanoparticles and nanomaterials have wide applications in electronics, physics, material design, being also utilized as sensors, catalysts, and more and more in biomedicine. Microemulsions are an exceptionally suitable medium for the synthesis of nanoparticles due to their thermodynamical stability, great solubility of both polar and nonpolar components, as well as their ability to control the size, dispersity and shape of the particles. This review presents microemulsion techniques for the synthesis of inorganic nanoparticles. It takes place in water-in-oil microemulsions by mixing one microemulsion with a cationic precursor, and the other with a precipitating or reducing agent, or by direct addition of reducing agents or gas (O2, NH3 ili CO2 into microemul sion (Fig. 1. Metal nanoparticles are used as catalysts, sensors, ferrofluids etc. They are produced by reducing the metal cation with a suitable reducing agent. In a similar way, one can prepare nanoparticles of alloys from the metal salts, provided that the metals are mutually soluble. The microemulsion technique is also suitable for depositing nanoparticles onto various surfaces. Highly active catalysts made from nanoparticles of Pt, Pd, Rh and other noble metals may be obtained in this way. Metal oxides and hydroxides may be prepared by hydrolysis or precipitation in the water core of microemulsion. Precipitation can be initiated by adding the base or precipitating agent into the microemulsion with water solution of metal ions. Similarly, nanoparticles may be prepared of sulphides, halogenides, cyanides, carbonates, sulphates and other insoluble metal salts. To prevent oxidation of nanoparticles, especially Fe, the particles are coated with inert metals, oxides, various polymers etc. Coating may provide additional functionality; e.g. coating with gold allows subsequent functionalization with organic compounds containing sulphur, due to the strong Au–S bond. Polymer coatings decrease

  20. Albumin nanoparticles with synergistic antitumor efficacy against metastatic lung cancers.

    Science.gov (United States)

    Kim, Bomi; Seo, Bohyung; Park, Sanghyun; Lee, Changkyu; Kim, Jong Oh; Oh, Kyung Taek; Lee, Eun Seong; Choi, Han-Gon; Youn, Yu Seok

    2017-10-01

    Albumin nanoparticles are well-known as effective drug carriers used to deliver hydrophobic chemotherapeutic agents. Albumin nanoparticles encapsulating curcumin and doxorubicin were fabricated using slightly modified nanoparticle albumin-bound (nab™) technology, and the synergistic effects of these two drugs were examined. Albumin nanoparticles encapsulating curcumin, doxorubicin, and both curcumin and doxorubicin were prepared using a high pressure homogenizer. The sizes of albumin nanoparticles were ∼130nm, which was considered to be suitable for the EPR (enhanced permeability and retention) effect. Albumin nanoparticles gradually released drugs over a period of 24h without burst effect. To confirm the synergistic effect of two drugs, in vitro cytotoxicity assay was performed using B16F10 melanoma cells. The cytotoxic effect on B16F10 melanoma cells was highest when co-treated with both curcumin and doxorubicin compared to single treatment of either curcumin and doxorubicin. The combined index calculated by medium-effect equation was 0.6069, indicating a synergistic effect. Results of confocal laser scanning microscopy and fluorescence-activated cell sorting corresponded to results from an in vitro cytotoxicity assay, indicating synergistic cytotoxicity induced by both drugs. A C57BL/6 mouse model induced by B16F10 lung metastasis was used to study in vivo therapeutic effects. When curcumin and doxorubicin were simultaneously treated, the metastatic melanoma mass in the lungs macroscopically decreased compared to curcumin or doxorubicin alone. Albumin nanoparticles encapsulating two anticancer drugs were shown to have an effective therapeutic result and would be an excellent way to treat resistant lung cancers. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. On the Feng-Rao bound for generalized hamming weights

    DEFF Research Database (Denmark)

    Geil, Hans Olav; Thommesen, Christian

    2006-01-01

    The Feng-Rao bound gives good estimates of the minimum distance of a large class of codes. In this work we are concerned with the problem of how to extend the Feng-Rao bound so that it deals with all the generalized Hamming weights. The problem was solved by Heijnen and Pellikaan in [7] for a large...... family of codes that includes the duals of one-point geometric Goppa codes and the q-ary Reed-Muller codes, but not the Feng-Rao improved such ones. We show that Heijnen and Pellikaan's results holds for the more general class of codes for which the traditional Feng-Rao bound can be applied. We also...... establish the connection to the Shibuya-Sakaniwa bound for generalized Hamming weights ([15], [16], [17], [18], [19] and [20]). More precisely we show that the Shibuya-Sakaniwa bound is a consequence of the extended Feng-Rao bound. In particular the extended Feng-Rao bound gives always at least as good...

  2. On the Feng-Rao bound for generalized Hamming weights

    DEFF Research Database (Denmark)

    Geil, Olav; Thommesen, Christian

    2005-01-01

    The Feng-Rao bound gives good estimates of the minimum distance of a large class of codes. In this work we are concerned with the problem of how to extend the Feng-Rao bound so that it deals with all the generalized Hamming weights. The problem was solved by Heijnen and Pellikaan in [7] for a large...... family of codes that includes the duals of one-point geometric Goppa codes and the q-ary Reed-Muller codes, but not the Feng-Rao improved such ones. We show that Heijnen and Pellikaan’s results holds for the more general class of codes for which the traditional Feng-Rao bound can be applied. We also...... establish the connection to the Shibuya-Sakaniwa bound for generalized Hamming weights ([15], [16], [17], [18], [19] and [20]). More precisely we show that the Shibuya-Sakaniwa bound is a consequence of the extended Feng-Rao bound. In particular the extended Feng-Rao bound gives always at least as good...

  3. Two-phonon bound states in imperfect crystals

    International Nuclear Information System (INIS)

    Behera, S.N.; Samsur, Sk.

    1980-01-01

    The question of the occurrence of two-phonon bound states in imperfect crystals is investigated. It is shown that the anharmonicity mediated two-phonon bound state which is present in perfect crystals gets modified due to the presence of impurities. Moreover, the possibility of the occurrence of a purely impurity mediated two-phonon bound state is demonstrated. The bound state frequencies are calculated using the simple Einstein oscillator model for the host phonons. The two-phonon density of states for the imperfect crystal thus obtained has peaks at the combination and difference frequencies of two host phonons besides the peaks at the bound state frequencies. For a perfect crystal the theory predicts a single peak at the two-phonon bound state frequency in conformity with experimental observations and other theoretical calculations. Experimental data on the two-phonon infrared absorption and Raman scattering from mixed crystals of Gasub(1-c)Alsub(c)P and Gesub(1-c)Sisub(c) are analysed to provide evidence in support of impurity-mediated two-phonon bound states. The relevance of the zero frequency (difference spectrum) peak to the central peak, observed in structural phase transitions, is conjectured. (author)

  4. Lying for the Greater Good: Bounded Rationality in a Team

    Directory of Open Access Journals (Sweden)

    Oktay Sürücü

    2014-10-01

    Full Text Available This paper is concerned with the interaction between fully and boundedly rational agents in situations where their interests are perfectly aligned. The cognitive limitations of the boundedly rational agent do not allow him to fully understand the market conditions and lead him to take non-optimal decisions in some situations. Using categorization to model bounded rationality, we show that the fully rational agent can nudge, i.e., he can manipulate the information he sends and decrease the expected loss caused by the boundedly rational agent. Assuming different types for the boundedly rational agent, who differ only in the categories used, we show that the fully rational agent may learn the type of the boundedly rational agent along their interaction. Using this additional information, the outcome can be improved and the amount of manipulated information can be decreased. Furthermore, as the length of the interaction increases the probability that the fully rational agent learns the type of the boundedly rational agent grows

  5. Encapsulation of gold nanoparticles into self-assembling protein nanoparticles

    Directory of Open Access Journals (Sweden)

    Yang Yongkun

    2012-10-01

    Full Text Available Abstract Background Gold nanoparticles are useful tools for biological applications due to their attractive physical and chemical properties. Their applications can be further expanded when they are functionalized with biological molecules. The biological molecules not only provide the interfaces for interactions between nanoparticles and biological environment, but also contribute their biological functions to the nanoparticles. Therefore, we used self-assembling protein nanoparticles (SAPNs to encapsulate gold nanoparticles. The protein nanoparticles are formed upon self-assembly of a protein chain that is composed of a pentameric coiled-coil domain at the N-terminus and trimeric coiled-coil domain at the C-terminus. The self-assembling protein nanoparticles form a central cavity of about 10 nm in size, which is ideal for the encapsulation of gold nanoparticles with similar sizes. Results We have used SAPNs to encapsulate several commercially available gold nanoparticles. The hydrodynamic size and the surface coating of gold nanoparticles are two important factors influencing successful encapsulation by the SAPNs. Gold nanoparticles with a hydrodynamic size of less than 15 nm can successfully be encapsulated. Gold nanoparticles with citrate coating appear to have stronger interactions with the proteins, which can interfere with the formation of regular protein nanoparticles. Upon encapsulation gold nanoparticles with polymer coating interfere less strongly with the ability of the SAPNs to assemble into nanoparticles. Although the central cavity of the SAPNs carries an overall charge, the electrostatic interaction appears to be less critical for the efficient encapsulation of gold nanoparticles into the protein nanoparticles. Conclusions The SAPNs can be used to encapsulate gold nanoparticles. The SAPNs can be further functionalized by engineering functional peptides or proteins to either their N- or C-termini. Therefore encapsulation of gold

  6. Synthesis and characterization of thiolated pectin stabilized gold coated magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Arora, Varun, E-mail: varun.arora3986@gmail.com [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, Sector 16-C, Dwarka, New Delhi 110078 (India); Sood, Ankur, E-mail: ankursood02@gmail.com [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, Sector 16-C, Dwarka, New Delhi 110078 (India); Shah, Jyoti, E-mail: shah.jyoti1@gmail.com [National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India); Kotnala, R.K., E-mail: rkkotnala@nplindia.org [National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India); Jain, Tapan K., E-mail: tapankjain@gmail.com [University School of Basic and Applied Sciences, Guru Gobind Singh Indraprastha University, Sector 16-C, Dwarka, New Delhi 110078 (India)

    2016-04-15

    Core–shell nanoparticles, magnetic core and gold shell, were synthesized by reduction of gold chloride on the surface of magnetic nanoparticles; using tyrosine as a reducing agent. The formation of gold shell on magnetic nanoparticles was confirmed by X-ray diffraction (XRD) and UV-Visible spectroscopy. The core–shell nanoparticles (CSn) were conjugated with thiolated pectin to form a stable aqueous dispersion. The hydrodynamic size of thiolated pectin stabilized core–shell nanoparticles (TP-CSn) measured by Dynamic light scattering (DLS) was 160.5 nm with a poly dispersity index (PDI) of 0.302, whereas the mean particle size of TP-CSn calculated by high resolution transmission electron microscopy (HRTEM) was 10.8 ± 2.7 nm. The value of zeta potential for TP-CSn was −13.6 mV. There was a decrease in the value of saturation magnetization upon formation of the gold shell on magnetic nanoparticles. The amount of thiolated pectin bound to the surface of core–shell nanoparticles, calculated using Thermogravimetric analysis (TGA), was 6% of sample weight. - Highlights: • Use of side group of tyrosine (phenol) as a pH dependent reducing agent to synthesize gold coated magnetic nanoparticles. • Successful coating of gold shell on magnetic nanoparticles core. • Synthesis of thiolated pectin and stabilization of aqueous dispersion of core–shell nanoparticles with thiolated pectin. • The superparamagnetic behaviour of magnetic nanoparticles is retained after shell formation.

  7. Simplified Drift Analysis for Proving Lower Bounds in Evolutionary Computation

    DEFF Research Database (Denmark)

    Oliveto, Pietro S.; Witt, Carsten

    2011-01-01

    Drift analysis is a powerful tool used to bound the optimization time of evolutionary algorithms (EAs). Various previous works apply a drift theorem going back to Hajek in order to show exponential lower bounds on the optimization time of EAs. However, this drift theorem is tedious to read...... and to apply since it requires two bounds on the moment-generating (exponential) function of the drift. A recent work identifies a specialization of this drift theorem that is much easier to apply. Nevertheless, it is not as simple and not as general as possible. The present paper picks up Hajek’s line...

  8. Upper bound on the radii of black-hole photonspheres

    International Nuclear Information System (INIS)

    Hod, Shahar

    2013-01-01

    One of the most remarkable predictions of the general theory of relativity is the existence of black-hole “photonspheres”, compact null hypersurfaces on which massless particles can orbit the central black hole. We prove that every spherically-symmetric asymptotically flat black-hole spacetime is characterized by a photonsphere whose radius is bounded from above by r γ ⩽3M, where M is the total ADM mass of the black-hole spacetime. It is shown that hairy black-hole configurations conform to this upper bound. In particular, the null circular geodesic of the (bald) Schwarzschild black-hole spacetime saturates the bound

  9. Thermodynamic Upper Bound on Broadband Light Coupling with Photonic Structures

    KAUST Repository

    Yu, Zongfu

    2012-10-01

    The coupling between free space radiation and optical media critically influences the performance of optical devices. We show that, for any given photonic structure, the sum of the external coupling rates for all its optical modes are subject to an upper bound dictated by the second law of thermodynamics. Such bound limits how efficient light can be coupled to any photonic structure. As one example of application, we use this upper bound to derive the limit of light absorption in broadband solar absorbers. © 2012 American Physical Society.

  10. Bounds on the pomeron intercept from accelerator data

    International Nuclear Information System (INIS)

    Luna, E.G.S.; Menon, M.J.

    2002-01-01

    Taking into account the discrepancies in the pp and p-bar p total cross section data at √8 = 1.8 TeV, we estimate upper and lower bounds for the soft pomeron intercept. We make use of the Donnachie-Landshoff parameterization for the total cross section and derivative analyticity relations in order to calculate the ρ parameter. Individual and global fits to these quantities and tests with the subtraction constant allow to infer α IP (0) = 1.092 as upper bound and α IP (0) = 1.077 as lower bound. (author)

  11. Bounded-Angle Iterative Decoding of LDPC Codes

    Science.gov (United States)

    Dolinar, Samuel; Andrews, Kenneth; Pollara, Fabrizio; Divsalar, Dariush

    2009-01-01

    Bounded-angle iterative decoding is a modified version of conventional iterative decoding, conceived as a means of reducing undetected-error rates for short low-density parity-check (LDPC) codes. For a given code, bounded-angle iterative decoding can be implemented by means of a simple modification of the decoder algorithm, without redesigning the code. Bounded-angle iterative decoding is based on a representation of received words and code words as vectors in an n-dimensional Euclidean space (where n is an integer).

  12. OPRA capacity bounds for selection diversity over generalized fading channels

    KAUST Repository

    Hanif, Muhammad Fainan

    2014-05-01

    Channel side information at the transmitter can increase the average capacity by enabling optimal power and rate adaptation. The resulting optimal power and rate adaptation (OPRA) capacity rarely has a closed-form analytic expression. In this paper, lower and upper bounds on OPRA capacity for selection diversity scheme are presented. These bounds hold for variety of fading channels including log-normal and generalized Gamma distributed models and have very simple analytic expressions for easy evaluation even for kth best path selection. Some selected numerical results show that the newly proposed bounds closely approximate the actual OPRA capacity. © 2014 IEEE.

  13. Finite energy bounds for $\\piN$ scattering

    CERN Document Server

    Grassberger, P; Schwela, D

    1974-01-01

    Upper bounds on energy averaged pi N cross sections are given. Using low energy data and data from pi N backward scattering and NN to pi pi annihilation, it is found that sigma /sub tot/bounds are based on assumptions similar to those underlying Froissart's bound and are equal to it asymptotically. However, at finite but large energies, they increase much slower than what might have been anticipated on purely numerological grounds. Related problems in pp and Kp scattering are also discussed. (25 refs) .

  14. Inequalities and bounds for nucleon-nucleon scattering

    International Nuclear Information System (INIS)

    Ramandurai, K.S.

    1979-08-01

    The objective of this work is to derive model-independent inequalities and bounds for nucleon-nucleon elastic scattering amplitudes based on well-established theoretical principles and symmetries. Two classes of methods are used: algebraic and variational. In the algebraic part, the author derives inequalities and bounds for NN amplitudes and observables using their mutual relations and x symmetries. In the variational part, he employs Lagrange's method of undetermined multipliers to evaluate the bounds. He tests the predictions of a sample of proposed phase shifts at three different energies using the results obtained

  15. Electronically cloaked nanoparticles

    Science.gov (United States)

    Shen, Wenqing

    The concept of electronic cloaking is to design objects invisible to conduction electrons. The approach of electronic cloaking has been recently suggested to design invisible nanoparticle dopants with electronic scattering cross section smaller than 1% of the physical cross section (pi a2), and therefore to enhance the carrier mobility of bulk materials. The proposed nanoparticles have core-shell structures. The dopants are incorporated inside the core, while the shell layer serves both as a spacer to separate the charge carriers from their parent atoms and as a cloaking shell to minimize the scattering cross section of the electrons from the ionized nanoparticles. Thermoelectric materials are usually highly doped to have enough carrier density. Using invisible dopants could achieve larger thermoelectric power factors by enhancing the electronic mobility. Core-shell nanoparticles show an advantage over one-layer nanoparticles, which are proposed in three-dimensional modulation doping. However designing such nanoparticles is not easy as there are too many parameters to be considered. This thesis first shows an approach to design hollow nanoparticles by applying constrains on variables. In the second part, a simple mapping approach is introduced where one can identify possible core-shell particles by comparing the dimensionless parameters of chosen materials with provided maps. In both parts of this work, several designs with realistic materials were made and proven to achieve electronic cloaking. Improvement in the thermoelectric power factor compared to the traditional impurity doping method was demonstrated in several cases.

  16. Bound-bound transitions in the emission spectra of Ba+-He excimer

    Science.gov (United States)

    Moroshkin, P.; Kono, K.

    2016-05-01

    We present an experimental and theoretical study of the emission and absorption spectra of the Ba+ ions and Ba+*He excimer quasimolecules in the cryogenic Ba-He plasma. We observe several spectral features in the emission spectrum, which we assign to the electronic transitions between bound states of the excimer correlating to the 6 2P3 /2 and 5 2D3 /2 ,5 /2 states of Ba+. The resulting Ba+(5 2DJ) He is a metastable electronically excited complex with orbital angular momentum L =2 , thus expanding the family of known metal-helium quasimolecules. It might be suitable for high-resolution spectroscopic studies and for the search for new polyatomic exciplex structures.

  17. Liposome encapsulation of fluorescent nanoparticles: Quantum dots and silica nanoparticles

    International Nuclear Information System (INIS)

    Chen, C.-S.; Yao Jie; Durst, Richard A.

    2006-01-01

    Quantum dots (QDs) and silica nanoparticles (SNs) are relatively new classes of fluorescent probes that overcome the limitations encountered by organic fluorophores in bioassay and biological imaging applications. We encapsulated QDs and SNs in liposomes and separated nanoparticle-loaded liposomes from unencapsulated nanoparticles by size exclusion chromatography. Fluorescence correlation spectroscopy was used to measure the average number of nanoparticles inside each liposome. Results indicated that nanoparticle-loaded liposomes were formed and separated from unencapsulated nanoparticles by using a Sepharose gel. As expected, fluorescence self-quenching of nanoparticles inside liposomes was not observed. Each liposome encapsulated an average of three QDs. These studies demonstrated that nanoparticles could be successfully encapsulated into liposomes and provided a methodology to quantify the number of nanoparticles inside each liposome by fluorescence correlation spectroscopy

  18. Gas Phase Nanoparticle Synthesis

    Science.gov (United States)

    Granqvist, Claes; Kish, Laszlo; Marlow, William

    This book deals with gas-phase nanoparticle synthesis and is intended for researchers and research students in nanomaterials science and engineering, condensed matter physics and chemistry, and aerosol science. Gas-phase nanoparticle synthesis is instrumental to nanotechnology - a field in current focus that raises hopes for environmentally benign, resource-lean manufacturing. Nanoparticles can be produced by many physical, chemical, and even biological routes. Gas-phase synthesis is particularly interesting since one can achieve accurate manufacturing control and hence industrial viability.

  19. Resonant halide perovskite nanoparticles

    Science.gov (United States)

    Tiguntseva, Ekaterina Y.; Ishteev, Arthur R.; Komissarenko, Filipp E.; Zuev, Dmitry A.; Ushakova, Elena V.; Milichko, Valentin A.; Nesterov-Mueller, Alexander; Makarov, Sergey V.; Zakhidov, Anvar A.

    2017-09-01

    The hybrid halide perovskites is a prospective material for fabrication of cost-effective optical devices. Unique perovskites properties are used for solar cells and different photonic applications. Recently, perovskite-based nanophotonics has emerged. Here, we consider perovskite like a high-refractive index dielectric material, which can be considered to be a basis for nanoparticles fabrication with Mie resonances. As a result, we fabricate and study resonant perovskite nanoparticles with different sizes. We reveal, that spherical nanoparticles show enhanced photoluminescence signal. The achieved results lay a cornerstone in the field of novel types of organic-inorganic nanophotonics devices with optical properties improved by Mie resonances.

  20. Assembling RNA Nanoparticles.

    Science.gov (United States)

    Xiao, Shou-Jun

    2017-01-01

    RNA nanoparticles are designed and self-assembled according to noncanonical interactions of naturally conserved RNA motifs and/or canonical Watson-Crick base-pairing interactions, which have potential applications in gene therapy and nanomedicine. These artificially engineered nanoparticles are mainly synthesized from in vitro transcribed RNAs, purified by denaturing and native polyacrylamide gel electrophoresis (PAGE), and characterized with native PAGE, AFM, and TEM technologies. The protocols of in vitro transcription, denaturing and native PAGE, and RNA nanoparticle self-assembly are described in detail.

  1. Analytical detection and biological assay of antileukemic drug using gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Selvaraj, V. [Department of Chemical Engineering, Alagappa College of Technology, Anna University, Chennai 600025 (India)]. E-mail: rajselva_77@yahoo.co.in; Alagar, M. [Department of Chemical Engineering, Alagappa College of Technology, Anna University, Chennai 600025 (India)]. E-mail: mkalagar@yahoo.com; Hamerton, I. [Chemistry Division, School of Biomedical and Molecular Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2006-11-12

    Gold nanoparticles are reported and evaluated as probes for the detection of anticancer drug 6-mercaptopurine (6-MP). The nature of binding between 6-MP and the gold nanoparticles via complexation is investigated using ultraviolet-visible spectrum, cyclic voltammetry, transmission electron microscopy, fluorescence and Fourier transform infrared (FT-IR) spectroscopy. The bound antileukemic drug is fluorescent and the quenching property of gold nanoparticles could be exploited for biological investigations. The 6-MP-colloidal gold complex is observed to have appreciable antibacterial and antifungal activity against Micrococcus luteus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Aspergillus fumigatus, and Aspergillus niger. The experimental studies suggest that gold nanoparticles have the potential to be used as effective carriers for anticancer drugs.

  2. Antibacterial surfaces by adsorptive binding of polyvinyl-sulphonate-stabilized silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Vasilev, Krasimir; Sah, Vasu R; Goreham, Renee V; Short, Robert D [Mawson Institute, University of South Australia, Mawson Lakes Campus, Mawson Lakes, Adelaide, SA 5095 (Australia); Ndi, Chi; Griesser, Hans J, E-mail: Krasimir.vasilev@unisa.edu.au [Ian Wark Research Institute, University of South Australia, Mawson Lakes, Adelaide, SA 5095 (Australia)

    2010-05-28

    This paper presents a novel and facile method for the generation of efficient antibacterial coatings which can be applied to practically any type of substrate. Silver nanoparticles were stabilized with an adsorbed surface layer of polyvinyl sulphonate (PVS). This steric layer provided excellent colloidal stability, preventing aggregation over periods of months. PVS-coated silver nanoparticles were bound onto amine-containing surfaces, here produced by deposition of an allylamine plasma polymer thin film onto various substrates. SEM imaging showed no aggregation upon surface binding of the nanoparticles; they were well dispersed on amine surfaces. Such nanoparticle-coated surfaces were found to be effective in preventing attachment of Staphylococcus epidermidis bacteria and also in preventing biofilm formation. Combined with the ability of plasma polymerization to apply the thin polymeric binding layer onto a wide range of materials, this method appears promising for the fabrication of a wide range of infection-resistant biomedical devices.

  3. Chitosan-Coated Magnetic Nanoparticles with Low Chitosan Content Prepared in One-Step

    Directory of Open Access Journals (Sweden)

    Yolanda Osuna

    2012-01-01

    Full Text Available Chitosan-coated magnetic nanoparticles (CMNP were obtained at 50°C in a one-step method comprising coprecipitation in the presence of low chitosan content. CMNP showed high magnetization and superparamagnetism. They were composed of a core of 9.5 nm in average diameter and a very thin chitosan layer in accordance with electron microscopy measurements. The results from Fourier transform infrared spectrometry demonstrated that CMNP were obtained and those from thermogravimetric analysis allowed to determine that they were composed of 95 wt% of magnetic nanoparticles and 5 wt% of chitosan. 67% efficacy in the Pb+2 removal test indicated that only 60% of amino groups on CMNP surface bound to Pb, probably due to some degree of nanoparticle flocculation during the redispersion. The very low weight ratio chitosan to magnetic nanoparticles obtained in this study, 0.053, and the high yield of the precipitation reactions (≈97% are noticeable.

  4. Effect of surface charge on the cellular uptake of fluorescent magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kralj, Slavko, E-mail: slavko.kralj@ijs.si [Jozef Stefan Institute, Department for Materials Synthesis (Slovenia); Rojnik, Matija [University of Ljubljana, Faculty of Pharmacy (Slovenia); Romih, Rok [University of Ljubljana, Faculty of Medicine, Institute of Cell Biology (Slovenia); Jagodic, Marko [Institute of Mathematics, Physics and Mechanics (Slovenia); Kos, Janko [University of Ljubljana, Faculty of Pharmacy (Slovenia); Makovec, Darko [Jozef Stefan Institute, Department for Materials Synthesis (Slovenia)

    2012-10-15

    We report on the nanoparticle uptake into MCF10A neoT and PC-3 cells using flow cytometry, confocal microscopy, SQUID magnetometry, and transmission electron microscopy. The aim was to evaluate the influence of the nanoparticles' surface charge on the uptake efficiency. The surface of the superparamagnetic, silica-coated, maghemite nanoparticles was modified using amino functionalization for the positive surface charge (CNPs), and carboxyl functionalization for the negative surface charge (ANPs). The CNPs and ANPs exhibited no significant cytotoxicity in concentrations up to 500 {mu}g/cm{sup 3} in 24 h. The CNPs, bound to a plasma membrane, were intensely phagocytosed, while the ANPs entered cells through fluid-phase endocytosis in a lower internalization degree. The ANPs and CNPs were shown to be co-localized with a specific lysosomal marker, thus confirming their presence in lysosomes. We showed that tailoring the surface charge of the nanoparticles has a great impact on their internalization.

  5. P2-16: Dual-Bound Model and the Role of Time Bound in Perceptual Decision Making

    Directory of Open Access Journals (Sweden)

    Daeseob Lim

    2012-10-01

    Full Text Available The diffusion model (DM encapsulates the dynamics of perceptual decision within a ‘diffusion field’ that is defined by a basis with sensory-evidence (SE and time vectors. At the core of the DM, it assumes that a decision is not made until an evidence particle drifts in the diffusion field and eventually hits one of the two pre-fixed bounds defined in the SE axis. This assumption dictates when and which choice is made by referring to when and which bound will be hit by the evidence particle. What if urgency pressures the decision system to make a choice even when the evidence particle has yet hit the SE bound? Previous modeling attempts at coping with time pressure, despite differences in detail, all manipulated the coordinate of SE bounds. Here, we offer a novel solution by adopting another bound on the time axis. This ‘dual-bound’ model (DBM posits that decisions can also be made when the evidence particle hits a time bound, which is determined on a trial-by-trial basis by a ‘perceived time interval’ – how long the system can stay in the ‘diffusion’ field. The classic single-bound model (SBM exhibited systematic errors in predicting both the reaction time distributions and the time-varying bias in choice. Those errors were not corrected by previously proposed variants of the SBM until the time bound was introduced. The validity of the DBM was further supported by the strong across-individual correlation between observed precision of interval timing and the predicted trial-by-trial variability of the time bound.

  6. Synthesis and Characterization of Fe3O4 Magnetic Nanoparticles Coated with Carboxymethyl Chitosan Grafted Sodium Methacrylate

    Directory of Open Access Journals (Sweden)

    S. Asgari

    2014-01-01

    Full Text Available N-sodium acrylate-O-carboxymethyl chitosan [CMCH-g-PAA(Na] bound Fe3O4 nanoparticles were developed as a novel magnetic nanoparticles with an ionic structure that can be potentially used in many fields. CMCH-g-PAA (Na was obtained by grafting of sodium polyacrylate on O-carboxymethyl chitosan, which is an amphiphilic polyelectrolyte with the biocompatibility and biodegradability properties. According to the great interest for improving the stability of Fe3O4 nanoparticles, CMCH-g-PAA (Na was used as a stabilizer to prepare a well dispersed suspension of magnetic nanoparticle According to the results,the presence of CMCH-g-PAA(Na could eliminate agglomeration of magnetic nanoparticles without destroying the superparamagnetic  properties

  7. Circumvention of Parker's bound on galactic magnetic monopoles

    International Nuclear Information System (INIS)

    Dicus, D.A.; Teplitz, V.L.; Maryland Univ., College Park

    1983-01-01

    There is a possibility that a magnetic monopole has been observed. The monopole density implied by the observation appears to violate bounds on the density of such particles derived from the total mass density of the Universe and from the existence of galactic magnetic fields. It is shown that the observation is not inconsistent with these bounds if the monopoles and antimonopoles are bound into positronium like states with principal quantum n high enough so that the Earth's magnetic field will break them apart, but small enough so that the weaker galactic magnetic field will not. A range of values for n are determined and show that lifetimes for such bound states are longer than the current age of the Universe. (author)

  8. An upper bound on Q-star masses

    International Nuclear Information System (INIS)

    Hochron, D.R.; Selipsky, S.B.

    1992-06-01

    Q-stars (the gravitational generalization of Q-balls, strongly bound bulk matter that an appear in field theories of strongly interacting hadrons) are the only known impact objects consistent with the known bulk structure of nuclei and chiral symmetry that evade the Rhoades-Ruffini upper bound of 3.2M circle-dot . Generic bounds are quite weak: M Q-star circle-dot . If, however, we assume that the 1.558 ms pulsar is a Q-star, equilibrium. A stability criteria of rotating fluids place a much stronger upper bound of M c ≤ 5.3M circle-dot on such models under certain special assumptions. This has important implications for heavy compact objects such as Cygnus X-1

  9. Kodiak: An Implementation Framework for Branch and Bound Algorithms

    Science.gov (United States)

    Smith, Andrew P.; Munoz, Cesar A.; Narkawicz, Anthony J.; Markevicius, Mantas

    2015-01-01

    Recursive branch and bound algorithms are often used to refine and isolate solutions to several classes of global optimization problems. A rigorous computation framework for the solution of systems of equations and inequalities involving nonlinear real arithmetic over hyper-rectangular variable and parameter domains is presented. It is derived from a generic branch and bound algorithm that has been formally verified, and utilizes self-validating enclosure methods, namely interval arithmetic and, for polynomials and rational functions, Bernstein expansion. Since bounds computed by these enclosure methods are sound, this approach may be used reliably in software verification tools. Advantage is taken of the partial derivatives of the constraint functions involved in the system, firstly to reduce the branching factor by the use of bisection heuristics and secondly to permit the computation of bifurcation sets for systems of ordinary differential equations. The associated software development, Kodiak, is presented, along with examples of three different branch and bound problem types it implements.

  10. Comparing two reliability upper bounds for multistate systems

    International Nuclear Information System (INIS)

    Meng, Fan C.

    2005-01-01

    The path-cut reliability bound due to Esary and Proschan [J. Am. Stat. Assoc. 65 (1970) 329] and the minimax reliability bound due to Barlow and Proschan [Statistical Theory of Reliability and Life Testing: Probability Models, 1981] for binary systems have been generalized to multistate systems by Block and Savits [J. Appl. Probab. 19 (1982) 391]. Some comparison results concerning the two multistate lower bounds for various types of multistate systems are given by Meng [Probab. Eng. Inform. Sci. 16 (2002) 485]. In this note we compare the two multistate upper bounds and present results which generalize some previous ones obtained by Maymin [J. Stat. Plan. Inference 16 (1987) 337] for binary systems. Examples are given to illustrate our results

  11. Work extraction from quantum systems with bounded fluctuations in work

    Science.gov (United States)

    Richens, Jonathan G.; Masanes, Lluis

    2016-11-01

    In the standard framework of thermodynamics, work is a random variable whose average is bounded by the change in free energy of the system. This average work is calculated without regard for the size of its fluctuations. Here we show that for some processes, such as reversible cooling, the fluctuations in work diverge. Realistic thermal machines may be unable to cope with arbitrarily large fluctuations. Hence, it is important to understand how thermodynamic efficiency rates are modified by bounding fluctuations. We quantify the work content and work of formation of arbitrary finite dimensional quantum states when the fluctuations in work are bounded by a given amount c. By varying c we interpolate between the standard and minimum free energies. We derive fundamental trade-offs between the magnitude of work and its fluctuations. As one application of these results, we derive the corrected Carnot efficiency of a qubit heat engine with bounded fluctuations.

  12. An explicit local uniform large deviation bound for Brownian bridges

    NARCIS (Netherlands)

    Wittich, O.

    2005-01-01

    By comparing curve length in a manifold and a standard sphere, we prove a local uniform bound for the exponent in the Large Deviation formula that describes the concentration of Brownian bridges to geodesics.

  13. Effect of Bound Entanglement on the Convertibility of Pure States

    International Nuclear Information System (INIS)

    Ishizaka, Satoshi

    2004-01-01

    I show that bound entanglement strongly influences the quantum entanglement processing of pure states: If N distant parties share appropriate bound entangled states with positive partial transpose, all N-partite pure entangled states become inter-convertible by stochastic local operations and classical communication (SLOCC) at the single copy level. This implies that the Schmidt rank of a bipartite pure entangled state can be increased, and that two incomparable tripartite entanglement of the GHZ and W type can be inter-converted by the assistance of bound entanglement. Further, I propose the simplest experimental scheme for the demonstration of the corresponding bound-entanglement-assisted SLOCC. This scheme does not need quantum gates and is feasible for the current experimental technology of linear optics

  14. APS Beyond Positivity Bounds and the Fate of Massive Gravity

    CERN Document Server

    Bellazzini, Brando; Serra, Javi; Sgarlata, Francesco

    2018-04-18

    We constrain effective field theories by going beyond the familiar positivity bounds that follow from unitarity, analyticity, and crossing symmetry of the scattering amplitudes. As interesting examples, we discuss the implications of the bounds for the Galileon and ghost-free massive gravity. The combination of our theoretical bounds with the experimental constraints on the graviton mass implies that the latter is either ruled out or unable to describe gravitational phenomena, let alone to consistently implement the Vainshtein mechanism, down to the relevant scales of fifth-force experiments, where general relativity has been successfully tested. We also show that the Galileon theory must contain symmetry-breaking terms that are at most one-loop suppressed compared to the symmetry-preserving ones. We comment as well on other interesting applications of our bounds.

  15. Ensemble of classifiers based network intrusion detection system performance bound

    CSIR Research Space (South Africa)

    Mkuzangwe, Nenekazi NP

    2017-11-01

    Full Text Available This paper provides a performance bound of a network intrusion detection system (NIDS) that uses an ensemble of classifiers. Currently researchers rely on implementing the ensemble of classifiers based NIDS before they can determine the performance...

  16. Sampling and identification of gaseous and particle bounded air pollutants

    International Nuclear Information System (INIS)

    Kettrup, A.

    1993-01-01

    Air pollutants are gaseous, components of aerosols or particle bounded. Sampling, sample preparation, identification and quantification of compounds depend from kind and chemical composition of the air pollutants. Quality assurance of analytical data must be guaranted. (orig.) [de

  17. Deeply bound pionic states and modifications of hadrons

    International Nuclear Information System (INIS)

    Hirenzaki, S.

    2000-01-01

    We have studied the structure and formation of mesic atoms and mesic nuclei theoretically. The latest results on the deeply bound pionic atoms, the kaonic atoms and the sigma states are reported. (author)

  18. Capacity bounds for parallel IM-DD optical wireless channels

    KAUST Repository

    Chaaban, Anas; Rezki, Zouheir; Alouini, Mohamed-Slim

    2016-01-01

    A system consisting of parallel intensity-modulation direct-detection optical wireless channels with a total average intensity constraint is studied. Capacity upper and lower bounds for this system are derived. If channel-state information is available at the transmitter, the bounds have to be optimized with respect to intensity allocation over the parallel channels. The optimization of the lower bound is non-convex, however, the Karush-Kuhn-Tucker conditions can be used to find a list of possible solutions one of which is optimal. The optimal solution can then be found by an exhaustive search algorithm, which is computationally expensive. To overcome this, we propose a low-complexity intensity allocation algorithm which is nearly optimal. The optimized capacity lower bound coincides with the capacity at high signal-to-noise ratio. © 2016 IEEE.

  19. Bounded solutions for fuzzy differential and integral equations

    Energy Technology Data Exchange (ETDEWEB)

    Nieto, Juan J. [Departamento de Analisis Matematico Facultad de Matematicas Universidad de Santiago de Compostela, 15782 (Spain)] e-mail: amnieto@usc.es; Rodriguez-Lopez, Rosana [Departamento de Analisis Matematico Facultad de Matematicas Universidad de Santiago de Compostela, 15782 (Spain)] e-mail: amrosana@usc.es

    2006-03-01

    We find sufficient conditions for the boundness of every solution of first-order fuzzy differential equations as well as certain fuzzy integral equations. Our results are based on several theorems concerning crisp differential and integral inequalities.

  20. Bounds on the moment of inertia of nonrotating neutron stars

    International Nuclear Information System (INIS)

    Sabbadini, A.G.; Hartle, J.B.

    1977-01-01

    Upper and lower bounds are placed on the moments of inertia of relativistic, spherical, perfect fluid neutron stars assuming that the pressure p and density p are positive and that (dp/drho) is positive. Bounds are obtained (a) for the moment of inertia of a star with given mass and radius, (b) for the moment of inertia of neutron stars for which the equation of state is known below a given density rho/sub omicron/and (c) for the mass-moment of inertia relation for stars whose equation of state is known below a given density rho/sub omicron/The bounds are optimum ones in the sense that there always exists a configuration consistent with the assumptions having a moment of inertia equal to that of the bound. The implications of the results for the maximum mass of slowly rotating neutron stars are discussed

  1. Determination of total, and bound Se in sera by INAA

    International Nuclear Information System (INIS)

    Spate, V.L.; Mason, M.M.; Reams, C.L.; Baskett, C.K.; Morris, J.S.; Mills, D.S.

    1994-01-01

    The comparison between the total selenium in serum ('total Se') with that which is apparently bound to high molecular weight (> 12.000 D) species, presumably proteins ('bound Se') was reported. Nine hundred seventy seven (977) serum samples arising out of a population-based epidemiological study were prepared in duplicate for the determination of 'total Se' by pipeting directly into irradiation vials; and separate duplicate aliquots were dialyzed against DI water for the determination of 'bound Se'. All samples were analyzed by neutron activation analysis via 77m Se (17.4s) A small dialyzable Se component (∼ 6%) ('free Se'), defined as the difference between the 'total Se' minus the 'bound Se', was identified. (author) 2 refs.; 3 figs.; 5 tabs

  2. Capacity bounds for parallel IM-DD optical wireless channels

    KAUST Repository

    Chaaban, Anas

    2016-07-26

    A system consisting of parallel intensity-modulation direct-detection optical wireless channels with a total average intensity constraint is studied. Capacity upper and lower bounds for this system are derived. If channel-state information is available at the transmitter, the bounds have to be optimized with respect to intensity allocation over the parallel channels. The optimization of the lower bound is non-convex, however, the Karush-Kuhn-Tucker conditions can be used to find a list of possible solutions one of which is optimal. The optimal solution can then be found by an exhaustive search algorithm, which is computationally expensive. To overcome this, we propose a low-complexity intensity allocation algorithm which is nearly optimal. The optimized capacity lower bound coincides with the capacity at high signal-to-noise ratio. © 2016 IEEE.

  3. Lower bounds on Q of some dipole shapes

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.

    2016-01-01

    The lower bound on the radiation Q of an arbitrary electrically small antenna shape can be determined by finding the optimal electric current density on the exterior surface of the shape, such that the Q of this current radiating in free space is minimized, and then augmenting it with a magnetic...... current density cancelling the fields inside the shape's surface. The Q of these coupled electric and magnetic currents radiating in free space is the lower bound on Q for the given shape. The approach is exemplified and its general applicability is substantiated by computing the lower bounds...... of spherically capped dipoles and comparing the results to the known bounds of a sphere and a thin cylinder....

  4. Possible circumvention of Parker's bound on galactic magnetic monopoles

    International Nuclear Information System (INIS)

    Dicus, D.A.; Teplitz, V.L.

    1983-04-01

    There is a possibility that a magnetic monople has observed. The monopole density implied by the observation appears to violate bounds on the density of such particles derived from the total mass density of the universe and from the existence of galactic magnetic fields. We show that the observation is not inconsistent with these bounds if the monopoles and antimonopoles are bound into positronium - like states with principal quantum n high enough so that the earth's magnetic field will break them apart, but small enough so that the weaker galactic mangetic field will not. We determine a range of values for n and show that lifetimes for such bound states are longer than the current age of the universe

  5. Inequalities Involving Upper Bounds for Certain Matrix Operators

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences; Volume 116; Issue 3. Inequalities Involving Upper Bounds for Certain Matrix Operators. R Lashkaripour D Foroutannia. Volume ... Keywords. Inequality; norm; summability matrix; Hausdorff matrix; Hilbert matrix; weighted sequence space; Lorentz sequence space.

  6. Quantifying Bounded Rationality: Managerial Behaviour and the Smith Predictor

    OpenAIRE

    Riddalls, C.E.; Bennett, S.

    2001-01-01

    The concept of bounded rationality in decision making and research on its relegation to aggregate system dynamics is examined. By recasting one such example of a dynamic system, the Beer Game, as a Smith predictor control system is derived. A stability analysis is then employed to support the and qualify the assertion that the level of bounded rationality can adversely affect the aggregate dynamic behaviour of such supply chains. The analytical basis of these calculations enables the qualific...

  7. Application of Beyond Bound Decoding for High Speed Optical Communications

    DEFF Research Database (Denmark)

    Li, Bomin; Larsen, Knud J.; Vegas Olmos, Juan José

    2013-01-01

    This paper studies the application of beyond bound decoding method for high speed optical communications. This hard-decision decoding method outperforms traditional minimum distance decoding method, with a total net coding gain of 10.36 dB.......This paper studies the application of beyond bound decoding method for high speed optical communications. This hard-decision decoding method outperforms traditional minimum distance decoding method, with a total net coding gain of 10.36 dB....

  8. An upper bound for the proton temperature anisotrophy

    International Nuclear Information System (INIS)

    Gary, S.P.

    1994-01-01

    This tutorial describes recent research concerning the upper bound on the hot proton temperature anisotropy imposed by wave-particle scattering due to enhanced fluctuations from the electromagnetic proton cyclotron anisotropy instability. This upper bound, which has been observed in both the magnetosheath and the outer magnetosphere, represents a limited closure relation for the equations of anisotropic magnetohydrodynamics. Such a closure relation has the potential to improve the predictive capability of large-scale anisotropic models of the magnetosphere

  9. Consensus of Heterogeneous Multiagent Systems with Arbitrarily Bounded Communication Delay

    Directory of Open Access Journals (Sweden)

    Xue Li

    2017-01-01

    Full Text Available This paper focuses on the consensus problem of high-order heterogeneous multiagent systems with arbitrarily bounded communication delays. Through the method of nonnegative matrices, we get a sufficient consensus condition for the systems with dynamically changing topology. The results of this paper show, even when there are arbitrarily bounded communication delays in the systems, all agents can reach a consensus no matter whether there are spanning trees for the corresponding communication graphs at any time.

  10. Probabilistic Lower Bounds for Approximation by Shallow Perceptron Networks

    Czech Academy of Sciences Publication Activity Database

    Kůrková, Věra; Sanguineti, M.

    2017-01-01

    Roč. 91, July (2017), s. 34-41 ISSN 0893-6080 R&D Projects: GA ČR GA15-18108S Institutional support: RVO:67985807 Keywords : shallow networks * perceptrons * model complexity * lower bounds on approximation rates * Chernoff-Hoeffding bounds Subject RIV: IN - Informatics, Computer Science OBOR OECD: Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8) Impact factor: 5.287, year: 2016

  11. Exchange interaction in scattering on the bound state

    International Nuclear Information System (INIS)

    Arkhipov, A.A.; Savrin, V.I.

    1975-01-01

    In the framework of the one-time formulation of three-body problem in quantum field theory, the problem of scattering on the bound state is considered for the case when one of the incident particles is identical to one of the particles of the target. It is shown that due to the identical nature of these particles the exchange interaction takes place which can be connected with the mechanism of scattering on the bound state with the rearrangement

  12. Can the Σ-nn system be bound?

    International Nuclear Information System (INIS)

    Stadler, A.; Gibson, B.F.

    1994-01-01

    Motivated by the Σ-hypernuclear states reported in (K - ,π ± ) experiments, we have explored the possibility that there exists a particle-stable Σ - nn bound state. For the Juelich A hyperon-nucleon, realistic-force model, our calculations yield little reason to expect a positive-parity bound state or resonance in either the J=1/2 or the J=3/2 channels

  13. Parity lifetime of bound states in a proximitized semiconductor nanowire

    DEFF Research Database (Denmark)

    Higginbotham, Andrew Patrick; Albrecht, Sven Marian; Kirsanskas, Gediminas

    2015-01-01

    Quasiparticle excitations can compromise the performance of superconducting devices, causing high frequency dissipation, decoherence in Josephson qubits, and braiding errors in proposed Majorana-based topological quantum computers. Quasiparticle dynamics have been studied in detail in metallic...... superconductor layer, yielding an isolated, proximitized nanowire segment. We identify Andreev-like bound states in the semiconductor via bias spectroscopy, determine the characteristic temperatures and magnetic fields for quasiparticle excitations, and extract a parity lifetime (poisoning time) of the bound...

  14. Computing variational bounds for flow through random aggregates of Spheres

    International Nuclear Information System (INIS)

    Berryman, J.G.

    1983-01-01

    Known formulas for variational bounds on Darcy's constant for slow flow through porous media depend on two-point and three-poiint spatial correlation functions. Certain bounds due to Prager and Doi depending only a two-point correlation functions have been calculated for the first time for random aggregates of spheres with packing fractions (eta) up to eta = 0.64. Three radial distribution functions for hard spheres were tested for eta up to 0.49: (1) the uniform distribution or ''well-stirred approximation,'' (2) the Percus Yevick approximation, and (3) the semi-empirical distribution of Verlet and Weis. The empirical radial distribution functions of Benett andd Finney were used for packing fractions near the random-close-packing limit (eta/sub RCP/dapprox.0.64). An accurate multidimensional Monte Carlo integration method (VEGAS) developed by Lepage was used to compute the required two-point correlation functions. The results show that Doi's bounds are preferred for eta>0.10 while Prager's bounds are preferred for eta>0.10. The ''upper bounds'' computed using the well-stirred approximation actually become negative (which is physically impossible) as eta increases, indicating the very limited value of this approximation. The other two choices of radial distribution function give reasonable results for eta up to 0.49. However, these bounds do not decrease with eta as fast as expected for large eta. It is concluded that variational bounds dependent on three-point correlation functions are required to obtain more accurate bounds on Darcy's constant for large eta

  15. Observations of bound and unbound states of Ce−

    International Nuclear Information System (INIS)

    Walter, C W; Li, Y-G; Matyas, D J; Alton, R M; Lou, S E; III, R L Field; Gibson, N D; Hanstorp, D

    2012-01-01

    The negative ion of cerium has been investigated with tunable infrared laser photodetachment spectroscopy over selected photon energy ranges between 0.56 − 0.70 eV. The spectrum reveals several sharp peaks due to negative ion resonances and possible bound-bound transitions in Ce − . The newly observed transitions, together with our previous measurements, provide insight into the rich near-threshold spectrum of this lanthanide negative ion.

  16. A lower bound on the mass of dark matter particles

    International Nuclear Information System (INIS)

    Boyarsky, Alexey; Ruchayskiy, Oleg; Iakubovskyi, Dmytro

    2009-01-01

    We discuss the bounds on the mass of Dark Matter (DM) particles, coming from the analysis of DM phase-space distribution in dwarf spheroidal galaxies (dSphs). After reviewing the existing approaches, we choose two methods to derive such a bound. The first one depends on the information about the current phase space distribution of DM particles only, while the second one uses both the initial and final distributions. We discuss the recent data on dSphs as well as astronomical uncertainties in relevant parameters. As an application, we present lower bounds on the mass of DM particles, coming from various dSphs, using both methods. The model-independent bound holds for any type of fermionic DM. Stronger, model-dependent bounds are quoted for several DM models (thermal relics, non-resonantly and resonantly produced sterile neutrinos, etc.). The latter bounds rely on the assumption that baryonic feedback cannot significantly increase the maximum of a distribution function of DM particles. For the scenario in which all the DM is made of sterile neutrinos produced via non-resonant mixing with the active neutrinos (NRP) this gives m NRP > 1.7 keV. Combining these results in their most conservative form with the X-ray bounds of DM decay lines, we conclude that the NRP scenario remains allowed in a very narrow parameter window only. This conclusion is independent of the results of the Lyman-α analysis. The DM model in which sterile neutrinos are resonantly produced in the presence of lepton asymmetry remains viable. Within the minimal neutrino extension of the Standard Model (the νMSM), both mass and the mixing angle of the DM sterile neutrino are bounded from above and below, which suggests the possibility for its experimental search

  17. Buneman instability and Pierce instability in a collisionless bounded plasma

    International Nuclear Information System (INIS)

    Iizuka, Satoru; Saeki, Koichi; Sato, Noriyoshi; Hatta, Yoshisuke

    1983-01-01

    A systematic experiment is performed on the Buneman instability and the Pierce instability in a bounded plasma consisting of beam electrons and stationary ions. Current fluctuations are confirmed to be induced by the Buneman instability. On the other hand, the Pierce instability gives rise to a current limitation. The phenomena are well explained by Mikhailovskii's theory taking account of ion motion in a bounded plasma. (author)

  18. Upper Bounds for Ruin Probability with Stochastic Investment Return

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lihong

    2005-01-01

    Risk models with stochastic investment return are widely held in practice, as well as in more challenging research fields. Risk theory is mainly concerned with ruin probability, and a tight bound for ruin probability is the best for practical use. This paper presents a discrete time risk model with stochastic investment return. Conditional expectation properties and martingale inequalities are used to obtain both exponential and non-exponential upper bounds for the ruin probability.

  19. Infinite Horizon Discrete Time Control Problems for Bounded Processes

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available We establish Pontryagin Maximum Principles in the strong form for infinite horizon optimal control problems for bounded processes, for systems governed by difference equations. Results due to Ioffe and Tihomirov are among the tools used to prove our theorems. We write necessary conditions with weakened hypotheses of concavity and without invertibility, and we provide new results on the adjoint variable. We show links between bounded problems and nonbounded ones. We also give sufficient conditions of optimality.

  20. Quantum Bound to Chaos and the Semiclassical Limit

    Science.gov (United States)

    Kurchan, Jorge

    2018-06-01

    We discuss the quantum bound on chaos in the context of the free propagation of a particle in an arbitrarily curved surface at low temperatures. The semiclassical calculation of the Lyapunov exponent can be performed in much the same way as the corresponding one for the `Loschmidt echo'. The bound appears here as the impossibility to scatter a wave, by effect of the curvature, over characteristic lengths smaller than the deBroglie wavelength.

  1. Temperature bounds in a model of laminar flames

    International Nuclear Information System (INIS)

    Kirane, M.; Badraoui, S.

    1994-06-01

    We consider reaction-diffusion equations coupling temperature and mass fraction in one-step-reaction model of combustion in R N . Uniform temperature bounds are derived when the Lewis number is less than one. This result completes the case of Lewis number greater than one studied by J.D. Avrin and M. Kirane ''Temperature growth and temperature bounds in special cases of combustion models'' (to appear in Applicable Analysis). (author). 5 refs

  2. Improved Rosen's conditions on bound states of Schroedinger operators

    International Nuclear Information System (INIS)

    Exner, P.

    1984-01-01

    We derive a necessary condition on a Schroedinger operator H=-Δ+V on Lsup(2)(Rsup(d)), d>=3 to have a bound state below a given energy epsilon, and a lower bound to the ground-state energy of H. These conditions are expressed in terms of the potential V alone, and generalize the recent results of Rosen to the dimensions d>3 and to the potentials that are not necessarily rapidly decreasing. Some examples are given

  3. A Lagrangian lower bound for the container transshipment problem at a railway hub for a fast branch-and-bound algorithm

    OpenAIRE

    M Barketau; H Kopfer; E Pesch

    2013-01-01

    In this paper, we consider the container transshipment problem at a railway hub. A simple lower bound known for this problem will be improved by a new Lagrangian relaxation lower bound. Computational tests show that this lower bound outperforms the simple one and decreases substantially the run time of the branch-and-bound algorithm.

  4. Intravenously administered gold nanoparticles pass through the blood-retinal barrier depending on the particle size, and induce no retinal toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Hun; Kim, Jin Hyoung; Yu, Young Suk [Department of Ophthalmology, Seoul National University College of Medicine and Seoul Artificial Eye Center, Clinical Research Institute, Seoul National University Hospital, Seoul 151744 (Korea, Republic of); Kim, Kyu-Won [NeuroVascular Coordination Research Center, College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 151742 (Korea, Republic of); Kim, Myung Hun, E-mail: hunin315@paran.com, E-mail: ysyu@snu.ac.kr [Department of Chemistry, Yonsei University, 134 Shinchon-dong, Seodaemun-ku, Seoul 120749 (Korea, Republic of)

    2009-12-16

    The retina maintains homeostasis through the blood-retinal barrier (BRB). Although it is ideal to deliver the drug to the retina via systemic administration, it is still challenging due to the BRB strictly regulating permeation from blood to the retina. Herein, we demonstrated that intravenously administered gold nanoparticles could pass through the BRB and are distributed in all retinal layers without cytotoxicity. After intravenous injection of gold nanoparticles into C57BL/6 mice, 100 nm nanoparticles were not detected in the retina whereas 20 nm nanoparticles passed through the BRB and were distributed in all retinal layers. 20 nm nanoparticles in the retina were observed in neurons (75 {+-} 5%), endothelial cells (17 {+-} 6%) and peri-endothelial glial cells (8 {+-} 3%), where nanoparticles were bound on the membrane. In the retina, cells containing nanoparticles did not show any structural abnormality and increase of cell death compared to cells without nanoparticles. Gold nanoparticles never affected the viability of retinal endothelial cells, astrocytes and retinoblastoma cells. Furthermore, gold nanoparticles never led to any change in expression of representative biological molecules including zonula occludens-1 and glut-1 in retinal endothelial cells, neurofilaments in differentiated retinoblastoma cells and glial fibrillary acidic protein in astrocytes. Therefore, our data suggests that small gold nanoparticles (20 nm) could be an alternative for drug delivery across the BRB, which could be safely applied in vivo.

  5. One-pot synthesis of biocompatible boronic acid-functionalized poly(methyl methacrylate) nanoparticles at sub-100 nm scale for glucose sensing

    Energy Technology Data Exchange (ETDEWEB)

    Sakalak, Huseyin [Selcuk University, Metallurgy and Materials Engineering (Turkey); Ulasan, Mehmet; Yavuz, Emine [Selcuk University, Advanced Technology Research and Application Center (Turkey); Camli, Sevket Tolga, E-mail: tolgacamli@gmail.com [Biyotez Machinery Chemistry R& D Co. Ltd. (Turkey); Yavuz, Mustafa Selman, E-mail: selmanyavuz@selcuk.edu.tr [Selcuk University, Metallurgy and Materials Engineering (Turkey)

    2014-12-15

    Poly(methyl methacrylate) nanoparticles containing 4-vinylphenyl boronic acid were synthesized in one pot by surfactant-free emulsion polymerization. The nanoparticles were characterized by scanning electron microscopy and dynamic light scattering. Boron content in the nanoparticles was confirmed by electron-dispersive X-ray spectroscopy. In polymerization process, several co-monomer ratios were studied in order to obtain optimum nanoparticle size. Average hydrodynamic diameter and polydispersity index of nanoparticles versus variation of acetone percentage in the solvent mixture and total monomer concentration were investigated. The effect of boronic acid concentration in the monomer mixture on nanoparticle size and size distribution was also reported. Without further functionalization to the nanoparticles, the catechol dye, alizarin red S, was bound to boronic acid-containing nanoparticles. These nanoparticles behave as a nanosensor by which glucose or fructose can be easily detected. Dye-containing nanoparticles were undertaken displacement reaction by glucose or fructose. The glucose or fructose content was also monitored by UV–Visible spectrophotometer. Furthermore, cytotoxicity studies of boronic acid-carrying poly(methyl methacrylate) nanoparticles were carried out in 3T3 cells, which showed no toxicity effect on the cells.

  6. Intravenously administered gold nanoparticles pass through the blood-retinal barrier depending on the particle size, and induce no retinal toxicity

    International Nuclear Information System (INIS)

    Kim, Jeong Hun; Kim, Jin Hyoung; Yu, Young Suk; Kim, Kyu-Won; Kim, Myung Hun

    2009-01-01

    The retina maintains homeostasis through the blood-retinal barrier (BRB). Although it is ideal to deliver the drug to the retina via systemic administration, it is still challenging due to the BRB strictly regulating permeation from blood to the retina. Herein, we demonstrated that intravenously administered gold nanoparticles could pass through the BRB and are distributed in all retinal layers without cytotoxicity. After intravenous injection of gold nanoparticles into C57BL/6 mice, 100 nm nanoparticles were not detected in the retina whereas 20 nm nanoparticles passed through the BRB and were distributed in all retinal layers. 20 nm nanoparticles in the retina were observed in neurons (75 ± 5%), endothelial cells (17 ± 6%) and peri-endothelial glial cells (8 ± 3%), where nanoparticles were bound on the membrane. In the retina, cells containing nanoparticles did not show any structural abnormality and increase of cell death compared to cells without nanoparticles. Gold nanoparticles never affected the viability of retinal endothelial cells, astrocytes and retinoblastoma cells. Furthermore, gold nanoparticles never led to any change in expression of representative biological molecules including zonula occludens-1 and glut-1 in retinal endothelial cells, neurofilaments in differentiated retinoblastoma cells and glial fibrillary acidic protein in astrocytes. Therefore, our data suggests that small gold nanoparticles (20 nm) could be an alternative for drug delivery across the BRB, which could be safely applied in vivo.

  7. One-pot synthesis of biocompatible boronic acid-functionalized poly(methyl methacrylate) nanoparticles at sub-100 nm scale for glucose sensing

    International Nuclear Information System (INIS)

    Sakalak, Huseyin; Ulasan, Mehmet; Yavuz, Emine; Camli, Sevket Tolga; Yavuz, Mustafa Selman

    2014-01-01

    Poly(methyl methacrylate) nanoparticles containing 4-vinylphenyl boronic acid were synthesized in one pot by surfactant-free emulsion polymerization. The nanoparticles were characterized by scanning electron microscopy and dynamic light scattering. Boron content in the nanoparticles was confirmed by electron-dispersive X-ray spectroscopy. In polymerization process, several co-monomer ratios were studied in order to obtain optimum nanoparticle size. Average hydrodynamic diameter and polydispersity index of nanoparticles versus variation of acetone percentage in the solvent mixture and total monomer concentration were investigated. The effect of boronic acid concentration in the monomer mixture on nanoparticle size and size distribution was also reported. Without further functionalization to the nanoparticles, the catechol dye, alizarin red S, was bound to boronic acid-containing nanoparticles. These nanoparticles behave as a nanosensor by which glucose or fructose can be easily detected. Dye-containing nanoparticles were undertaken displacement reaction by glucose or fructose. The glucose or fructose content was also monitored by UV–Visible spectrophotometer. Furthermore, cytotoxicity studies of boronic acid-carrying poly(methyl methacrylate) nanoparticles were carried out in 3T3 cells, which showed no toxicity effect on the cells

  8. Nanoparticle based-immunotherapy against allergy.

    Science.gov (United States)

    Gamazo, Carlos; Gastaminza, Gabriel; Ferrer, Marta; Sanz, María L; Irache, Juan M

    2014-01-01

    Allergic diseases are one of the most prevalent diseases, reaching epidemic proportions in developed countries. An allergic reaction occurs after contact with an environmental protein, such as inhalants allergens (pollen, animal dander, house dust mites), or food proteins. This response is known as part of the type 2 immunity that is counterbalanced by Type 1 immunity and Tregs. Widely used allergen-specific immunotherapy (IT) is a long term treatment to induce such switch from Th2 to Th1 response. However, conventional IT requires multiple allergen injections over a long period of time and is not free of risk of producing allergic reactions. As a consequence, new safer and faster immunotherapeutic methods are required. This review deals with allergen IT using nanoparticles as allergen delivery system that will allow a different way of administration, reduce dose and diminish allergen exposure to IgE bound to mast cells or basophils.

  9. 21 CFR 862.1640 - Protein-bound iodine test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Protein-bound iodine test system. 862.1640 Section... Systems § 862.1640 Protein-bound iodine test system. (a) Identification. A protein-bound iodine test system is a device intended to measure protein-bound iodine in serum. Measurements of protein-bound...

  10. Chloroplast protein synthesis: thylakoid bound polysomes synthesize thylakoid proteins

    International Nuclear Information System (INIS)

    Hurewitz, J.; Jagendorf, A.T.

    1986-01-01

    Previous work indicated more polysomes bound to pea thylakoids in light than in the dark, in vivo. With isolated intact chloroplasts incubated in darkness, 24 to 74% more RNA was thylakoid-bound at pH 8.3 than at pH 7. Thus the major effect of light in vivo may be due to higher stroma pH. In isolated pea chloroplasts, initiation inhibitors (pactamycin and kanamycin) decreased the extent of RNA binding, and elongation inhibitors (lincomycin and streptomycin) increased it. Thus translation initiation and termination probably control the cycling of bound ribosomes. While only 3 to 6% of total RNA is in bound polysomes the incorporation of 3 H-Leu into thylakoids was proportional to the amount of this bound RNA. When Micrococcal nuclease-treated thylakoids were added to labeled runoff translation products of stroma ribosomes, less than 1% of the label adhered to the added membranes; but 37% of the labeled products made by thylakoid polysomes were bound. These data support the concept that stroma ribosomes are recruited into thylakoid proteins

  11. Dynamic Garment Simulation based on Hybrid Bounding Volume Hierarchy

    Directory of Open Access Journals (Sweden)

    Zhu Dongyong

    2016-12-01

    Full Text Available In order to solve the computing speed and efficiency problem of existing dynamic clothing simulation, this paper presents a dynamic garment simulation based on a hybrid bounding volume hierarchy. It firstly uses MCASG graph theory to do the primary segmentation for a given three-dimensional human body model. And then it applies K-means cluster to do the secondary segmentation to collect the human body’s upper arms, lower arms, upper legs, lower legs, trunk, hip and woman’s chest as the elementary units of dynamic clothing simulation. According to different shapes of these elementary units, it chooses the closest and most efficient hybrid bounding box to specify these units, such as cylinder bounding box and elliptic cylinder bounding box. During the process of constructing these bounding boxes, it uses the least squares method and slices of the human body to get the related parameters. This approach makes it possible to use the least amount of bounding boxes to create close collision detection regions for the appearance of the human body. A spring-mass model based on a triangular mesh of the clothing model is finally constructed for dynamic simulation. The simulation result shows the feasibility and superiority of the method described.

  12. Cosmological stability bound in massive gravity and bigravity

    International Nuclear Information System (INIS)

    Fasiello, Matteo; Tolley, Andrew J.

    2013-01-01

    We give a simple derivation of a cosmological bound on the graviton mass for spatially flat FRW solutions in massive gravity with an FRW reference metric and for bigravity theories. This bound comes from the requirement that the kinetic term of the helicity zero mode of the graviton is positive definite. The bound is dependent only on the parameters in the massive gravity potential and the Hubble expansion rate for the two metrics. We derive the decoupling limit of bigravity and FRW massive gravity, and use this to give an independent derivation of the cosmological bound. We recover our previous results that the tension between satisfying the Friedmann equation and the cosmological bound is sufficient to rule out all observationally relevant FRW solutions for massive gravity with an FRW reference metric. In contrast, in bigravity this tension is resolved due to different nature of the Vainshtein mechanism. We find that in bigravity theories there exists an FRW solution with late-time self-acceleration for which the kinetic terms for the helicity-2, helicity-1 and helicity-0 are generically nonzero and positive making this a compelling candidate for a model of cosmic acceleration. We confirm that the generalized bound is saturated for the candidate partially massless (bi)gravity theories but the existence of helicity-1/helicity-0 interactions implies the absence of the conjectured partially massless symmetry for both massive gravity and bigravity

  13. Microscopic observation of magnon bound states and their dynamics.

    Science.gov (United States)

    Fukuhara, Takeshi; Schauß, Peter; Endres, Manuel; Hild, Sebastian; Cheneau, Marc; Bloch, Immanuel; Gross, Christian

    2013-10-03

    The existence of bound states of elementary spin waves (magnons) in one-dimensional quantum magnets was predicted almost 80 years ago. Identifying signatures of magnon bound states has so far remained the subject of intense theoretical research, and their detection has proved challenging for experiments. Ultracold atoms offer an ideal setting in which to find such bound states by tracking the spin dynamics with single-spin and single-site resolution following a local excitation. Here we use in situ correlation measurements to observe two-magnon bound states directly in a one-dimensional Heisenberg spin chain comprising ultracold bosonic atoms in an optical lattice. We observe the quantum dynamics of free and bound magnon states through time-resolved measurements of two spin impurities. The increased effective mass of the compound magnon state results in slower spin dynamics as compared to single-magnon excitations. We also determine the decay time of bound magnons, which is probably limited by scattering on thermal fluctuations in the system. Our results provide a new way of studying fundamental properties of quantum magnets and, more generally, properties of interacting impurities in quantum many-body systems.

  14. Effects of QCD bound states on dark matter relic abundance

    Energy Technology Data Exchange (ETDEWEB)

    Liew, Seng Pei [Department of Physics, The University of Tokyo,Bunkyo-ku, Tokyo 113-0033 (Japan); Luo, Feng [Kavli IPMU (WPI), UTIAS, The University of Tokyo,Kashiwa, Chiba 277-8583 (Japan)

    2017-02-17

    We study scenarios where there exists an exotic massive particle charged under QCD in the early Universe. We calculate the formation and dissociation rates of bound states formed by pairs of these particles, and apply the results in dark matter (DM) coannihilation scenarios, including also the Sommerfeld effect. We find that on top of the Sommerfeld enhancement, bound-state effects can further significantly increase the largest possible DM masses which can give the observed DM relic abundance, by ∼30–100% with respect to values obtained by considering the Sommerfeld effect only, for the color triplet or octet exotic particles we consider. In particular, it indicates that the Bino DM mass in the right-handed stop-Bino coannihilation scenario in the Minimal Supersymmetric extension of the Standard Model (MSSM) can reach ∼2.5 TeV, even though the potential between the stop and antistop prior to forming a bound state is repulsive. We also apply the bound-state effects in the calculations of relic abundance of long-lived or metastable massive colored particles, and discuss the implications on the BBN constraints and the abundance of a super-weakly interacting DM. The corrections for the bound-state effect when the exotic massive colored particles also carry electric charges, and the collider bounds are also discussed.

  15. Bound on viscosity and the generalized second law of thermodynamics

    International Nuclear Information System (INIS)

    Fouxon, Itzhak; Betschart, Gerold; Bekenstein, Jacob D.

    2008-01-01

    We describe a new paradox for ideal fluids. It arises in the accretion of an ideal fluid onto a black hole, where, under suitable boundary conditions, the flow can violate the generalized second law of thermodynamics. The paradox indicates that there is in fact a lower bound to the correlation length of any real fluid, the value of which is determined by the thermodynamic properties of that fluid. We observe that the universal bound on entropy, itself suggested by the generalized second law, puts a lower bound on the correlation length of any fluid in terms of its specific entropy. With the help of a new, efficient estimate for the viscosity of liquids, we argue that this also means that viscosity is bounded from below in a way reminiscent of the conjectured Kovtun-Son-Starinets lower bound on the ratio of viscosity to entropy density. We conclude that much light may be shed on the Kovtun-Son-Starinets bound by suitable arguments based on the generalized second law

  16. Functionalized diamond nanoparticles

    KAUST Repository

    Beaujuge, Pierre M.; El Tall, Omar; Raja, Inam U.

    2014-01-01

    A diamond nanoparticle can be functionalized with a substituted dienophile under ambient conditions, and in the absence of catalysts or additional reagents. The functionalization is thought to proceed through an addition reaction.

  17. Functionalized diamond nanoparticles

    KAUST Repository

    Beaujuge, Pierre M.

    2014-10-21

    A diamond nanoparticle can be functionalized with a substituted dienophile under ambient conditions, and in the absence of catalysts or additional reagents. The functionalization is thought to proceed through an addition reaction.

  18. Supercooled smectic nanoparticles

    DEFF Research Database (Denmark)

    Kuntsche, Judith; Koch, Michel H J; Fahr, Alfred

    2009-01-01

    Cholesteryl nonanoate (CN), myristate (CM), palmitate (CP) and oleate (CO) alone or in combination were evaluated as matrix lipids for the preparation of supercooled smectic nanoparticles with a high stability against recrystallization during storage. The phase behavior of the cholesterol esters......, laser diffraction combined with polarizing intensity differential scattering, DSC and SAXS. The morphology of selected formulations was studied by freeze-fracture electron microscopy. All smectic nanoparticles with a mixed cholesterol ester matrix were stable against recrystallization when stored...... at room temperature. Nanoparticles with a pure CN and mixed CM/CN matrix with a high fraction of CN (60% of the whole lipid matrix) could even be stored at 4 degrees C for at least 18 months without any recrystallization. As smectic nanoparticles are studied especially with regard to parenteral...

  19. Repairing Nanoparticle Surface Defects

    NARCIS (Netherlands)

    Marino, Emanuele; Kodger, Thomas E.; Crisp, R.W.; Timmerman, Dolf; MacArthur, Katherine E.; Heggen, Marc; Schall, Peter

    2017-01-01

    Solar devices based on semiconductor nanoparticles require the use of conductive ligands; however, replacing the native, insulating ligands with conductive metal chalcogenide complexes introduces structural defects within the crystalline nanostructure that act as traps for charge carriers. We

  20. Metallic Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    A. Hernando

    2005-01-01

    Full Text Available In this paper, we reviewed some relevant aspects of the magnetic properties of metallic nanoparticles with small size (below 4 nm, covering the size effects in nanoparticles of magnetic materials, as well as the appearance of magnetism at the nanoscale in materials that are nonferromagnetic in bulk. These results are distributed along the text that has been organized around three important items: fundamental magnetic properties, different fabrication procedures, and characterization techniques. A general introduction and some experimental results recently obtained in Pd and Au nanoparticles have also been included. Finally, the more promising applications of magnetic nanoparticles in biomedicine are indicated. Special care was taken to complete the literature available on the subject.

  1. Cryochemistry of Metal Nanoparticles

    International Nuclear Information System (INIS)

    Sergeev, Gleb B.

    2003-01-01

    The interaction of metal atoms, clusters and nanoparticles with different organic and inorganic substances were studied at low temperature (10-40K). Combination of matrix isolation technique and preparative cryochemistry was applied for the investigation of activity and selectivity of metal particles of different size. Encapsulation of metal nanoparticles in polymers was studied. The metal-polymer films thus obtained exhibited satisfactory sensitivity to ammonia

  2. Cryochemistry of Metal Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sergeev, Gleb B. [Moscow State University, Laboratory of Low Temperature Chemistry, Chemistry Department (Russian Federation)], E-mail: gbs@kinet.chem.msu.ru

    2003-12-15

    The interaction of metal atoms, clusters and nanoparticles with different organic and inorganic substances were studied at low temperature (10-40K). Combination of matrix isolation technique and preparative cryochemistry was applied for the investigation of activity and selectivity of metal particles of different size. Encapsulation of metal nanoparticles in polymers was studied. The metal-polymer films thus obtained exhibited satisfactory sensitivity to ammonia.

  3. Cryochemistry of Metal Nanoparticles

    Science.gov (United States)

    Sergeev, Gleb B.

    2003-12-01

    The interaction of metal atoms, clusters and nanoparticles with different organic and inorganic substances were studied at low temperature (10-40K). Combination of matrix isolation technique and preparative cryochemistry was applied for the investigation of activity and selectivity of metal particles of different size. Encapsulation of metal nanoparticles in polymers was studied. The metal-polymer films thus obtained exhibited satisfactory sensitivity to ammonia.

  4. Biomimetic magnetic nanoparticles

    OpenAIRE

    Klem, Michael T.; Young, Mark; Douglas, Trevor

    2005-01-01

    Magnetic nanoparticles are of considerable interest because of their potential use in high-density memory devices, spintronics, and applications in diagnostic medicine. The conditions for synthesis of these materials are often complicated by their high reaction temperatures, costly reagents, and post-processing requirements. Practical applications of magnetic nanoparticles will require the development of alternate synthetic strategies that can overcome these impediments. Biomimetic approaches...

  5. Nanolubricant: magnetic nanoparticle based

    Science.gov (United States)

    Trivedi, Kinjal; Parekh, Kinnari; Upadhyay, Ramesh V.

    2017-11-01

    In the present study magnetic nanoparticles of Fe3O4 having average particle diameter, 11.7 nm were synthesized using chemical coprecipitation technique and dispersed in alpha olefin hydrocarbon synthetic lubricating oil. The solid weight fraction of magnetic nanoparticles in the lubricating oil was varied from 0 wt% to 10 wt%. The tribological properties were studied using four-ball tester. The results demonstrate that the coefficient of friction and wear scar diameter reduces by 45% and 30%, respectively at an optimal value, i.e. 4 wt% of magnetic nanoparticles concentration. The surface characterization of worn surface was carried out using a scanning electron microscope, and energy dispersive spectroscopy. These results implied that rolling mechanism is responsible to reduce coefficient of friction while magnetic nanoparticles act as the spacer between the asperities and reduces the wear scar diameter. The surface roughness of the worn surface studied using an atomic force microscope shows a reduction in surface roughness by a factor of four when magnetic nanoparticles are used as an additive. The positive response of magnetic nanoparticles in a lubricating oil, shows the potential replacement of conventional lubricating oil.

  6. Protein trapping of nanoparticles

    International Nuclear Information System (INIS)

    Ang, Joo C.; Lin, Jack M.; Yaron, Peter N.; White, John W.

    2009-01-01

    Full text: We have observed the formation of protein-nanoparticle complexes at the air-water interfaces from three different methods of presenting the nanoparticles to proteins. The structures formed resemble the 'protein-nanoparticle corona' proposed by Lynch et al. [1-3) in relation to a possible route for nanoparticle entry into living cells. To do this, the methods of x-ray and neutron reflectivity (with isotopic contrast variation between the protein and nanoparticles) have been used to study the structures formed at the air-water interface of l 3 - casein presented to silica nanoparticle dispersions. Whilst the silica dispersions showed no observable reflectivity, strong signals appear in the reflectivity when protein is present. Drop-wise spreading of a small amount of protein at the air-silica sol interface and presentation of the silica sol to an isolated monomolecular protein film (made by the 'flow-trough' method [4]) gave an immediate signal. Mixing the components in solution only produces a slow response but in all cases a similar structure is formed. The different responses are interpreted in structural and stoichiometric ways.

  7. Targeted drug delivery with polymers and magnetic nanoparticles: covalent and noncovalent approaches, release control, and clinical studies

    Czech Academy of Sciences Publication Activity Database

    Ulbrich, Karel; Holá, K.; Šubr, Vladimír; Bakandritsos, A.; Tuček, J.; Zbořil, R.

    2016-01-01

    Roč. 116, č. 9 (2016), s. 5338-5431 ISSN 0009-2665 R&D Projects: GA ČR(CZ) GAP301/12/1254 Institutional support: RVO:61389013 Keywords : iron-oxide nanoparticles * cell lung-cancer * copolymer-bound doxorubicin Subject RIV: CD - Macromolecular Chemistry Impact factor: 47.928, year: 2016

  8. Biogenic Nanoparticles from Schwanniomyces occidentalis NCIM 3459: Mechanistic Aspects and Catalytic Applications.

    Science.gov (United States)

    Mohite, Pallavi; Apte, Mugdha; Kumar, Ameeta Ravi; Zinjarde, Smita

    2016-06-01

    When cells of Schwanniomyces occidentalis NCIM 3459 were incubated with 1 mM tetrachloroauric acid (HAuCl4) or silver nitrate (AgNO3), cell-associated nanoparticles were obtained. Their presence was confirmed by scanning electron microscope observations. The cell-free supernatant (CFS) of the yeast mediated the synthesis of gold nanoparticles. On account of the difficulties associated with the use of cell-bound nanoparticles, further work was restricted to extracellular nanoparticles. It was hypothesized that the CFS contained thermostable biomolecule(s) that mediated metal reduction reactions. Extraction of the CFS with chloroform/methanol (2:1) and subsequent separation by preparative thin layer chromatography led to the activity-guided purification of a glycolipid. The glycolipid was hydrolyzed and the glycone (glucose) and aglycone components (palmitic acid and oleic acid) were identified by gas chromatography-mass spectrometry. The purified glycolipid mediated the synthesis of gold and silver nanoparticles that were characterized by using an X-ray diffractometer and transmission electron microscope (TEM). The extracellular nanoparticles displayed catalytic activities and reduced 4-nitroaniline to benzene-1,4-diamine. This paper thus highlights nanoparticle synthesis by a hitherto unreported yeast culture, identifies the biomolecules involved in the process, and describes a potential application of the nanostructures.

  9. Covalent Immobilization of Bacillus licheniformis γ-Glutamyl Transpeptidase on Aldehyde-Functionalized Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Meng-Chun Chi

    2013-02-01

    Full Text Available This work presents the synthesis and use of surface-modified iron oxide nanoparticles for the covalent immobilization of Bacillus licheniformis γ-glutamyl transpeptidase (BlGGT. Magnetic nanoparticles were prepared by an alkaline solution of divalent and trivalent iron ions, and they were subsequently treated with 3-aminopropyltriethoxysilane (APES to obtain the aminosilane-coated nanoparticles. The functional group on the particle surface and the amino group of BlGGT was then cross-linked using glutaraldehyde as the coupling reagent. The loading capacity of the prepared nanoparticles for BlGGT was 34.2 mg/g support, corresponding to 52.4% recovery of the initial activity. Monographs of transmission electron microscopy revealed that the synthesized nanoparticles had a mean diameter of 15.1 ± 3.7 nm, and the covalent cross-linking of the enzyme did not significantly change their particle size. Fourier transform infrared spectroscopy confirmed the immobilization of BlGGT on the magnetic nanoparticles. The chemical and kinetic behaviors of immobilized BlGGT are mostly consistent with those of the free enzyme. The immobilized enzyme could be recycled ten times with 36.2% retention of the initial activity and had a comparable stability respective to free enzyme during the storage period of 30 days. Collectively, the straightforward synthesis of aldehyde-functionalized nanoparticles and the efficiency of enzyme immobilization offer wide perspectives for the practical use of surface-bound BlGGT.

  10. Self-oriented nanoparticles for site-selective immunoglobulin G recognition via epitope imprinting approach.

    Science.gov (United States)

    Çorman, Mehmet Emin; Armutcu, Canan; Uzun, Lokman; Say, Rıdvan; Denizli, Adil

    2014-11-01

    Molecular imprinting is a polymerization technique that provides synthetic analogs for template molecules. Molecularly imprinted polymers (MIPs) have gained much attention due to their unique properties such as selectivity and specificity for target molecules. In this study, we focused on the development of polymeric materials with molecular recognition ability, so molecular imprinting was combined with miniemulsion polymerization to synthesize self-orienting nanoparticles through the use of an epitope imprinting approach. Thus, L-lysine imprinted nanoparticles (LMIP) were synthesized via miniemulsion polymerization technique. Immunoglobulin G (IgG) was then bound to the cavities that specifically formed for L-lysine molecules that are typically found at the C-terminus of the Fc region of antibody molecules. The resulting nanoparticles makes it possible to minimize the nonspecific interaction between monomer and template molecules. In addition, the orientation of the entire IgG molecule was controlled, and random imprinting of the IgG was prevented. The optimum conditions were determined for IgG recognition using the imprinted nanoparticles. The selectivity of the nanoparticles against IgG molecules was also evaluated using albumin and hemoglobin as competitor molecules. In order to show the self-orientation capability of imprinted nanoparticles, human serum albumin (HSA) adsorption onto both the plain nanoparticles and immobilized nanoparticles by anti-human serum albumin antibody (anti-HSA antibody) was also carried out. Due to anti-HSA antibody immobilization on the imprinted nanoparticles, the adsorption capability of nanoparticles against HSA molecules vigorously enhanced. It is proved that the oriented immobilization of antibodies was appropriately succeeded. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Feasibility of MR imaging in evaluating breast cancer lymphangiogenesis using Polyethylene glycol-GoldMag nanoparticles

    International Nuclear Information System (INIS)

    Yang, H.; Zou, L.G.; Zhang, S.; Gong, M.F.; Zhang, D.; Qi, Y.Y.; Zhou, S.W.; Diao, X.W.

    2013-01-01

    Aim: To investigate the feasibility of evaluating tumour lymphangiogenesis using magnetic resonance imaging (MRI) in vivo. Materials and methods: Water-soluble polyethylene glycol (PEG)-GoldMag nanoparticles were obtained by combining GoldMag with PEG. The PEG-GoldMag nanoparticles were bound to anti-podoplanin antibody (PodAb) to construct PEG-GoldMag-pod molecular probes targeting lymphatic endothelial cells (LECs). The characteristics of the PEG-GoldMag-pod nanoparticles were tested. Using these nanoparticles, tumour lymphangiogenesis was evaluated using MRI in vitro and in vivo. Results: The average size of PEG-GoldMag nanoparticles was about 66.8 nm, and the nanoparticles were stably dispersed in the liquid phase for at least 15 days. After incubation for 24 h at different iron concentrations ranging from 5–45 μg/ml, the LECs were labelled with PEG-GoldMag-pod nanoparticles, in particular the breast cancer LECs. Dose-dependence was observed in the labelling efficiencies and MRI images of the labelled cells. In vitro, the labelling efficiencies and MRI images showed that the nanoparticles could detect podoplanin expression in LECs. In induced rat models of breast cancer, PEG-GoldMag-pod nanoparticles combined with lymphatic vessels were significantly detectable at MRI 60 min after nanoparticle administration, the signal intensity was negatively correlated with the lymphatic vessel density of breast cancer (r = −0.864, P = 0.000). Conclusions: The present study proves the feasibility of evaluating tumour lymphangiogenesis with MRI in vivo

  12. The need to study of bounding accident in reprocessing plant

    International Nuclear Information System (INIS)

    Segawa, Satoshi; Fujita, Kunio

    2013-01-01

    There is a clear consensus that the severe accident corresponds to the core damage accident for power reactors. On the other hand, for FCFs, there is no clear consensus on what is the accident to assess the safety in the region of beyond design basis, or what is the accident which has very low probability but large consequence. The need to examine a bounding consequence of each type of accident is explained to advance the rationality of safety management and regulation and, as a result, to reinforce the safety of a reprocessing plant. The likelihood of occurrence of an accident causing a bounding consequence should correspond to that of a severe accident at a nuclear power plant. The bounding consequence will be derived using the deterministic method and sound engineering judgment supplemented by the probabilistic method. Once an agreement on such a concept is reached among regulators, operators and related experts it will help to provide a solid basis to ensure the safety of a reprocessing plant independent of that of a nuclear power plant. In this paper, we show a preliminary risk profile of RRP calculated by QSA (Quantitative Safety Assessment) which JNFL developed. The profile shows that bounding consequences of various accidents in a range of occurrence frequency corresponding to a severe accident at a nuclear power plant. And we find that the bounding consequence of high-level liquid waste boiling is the largest among all in this range. Therefore, the risk of this event is shown in this paper as an example. To build a common consensus about bounding accidents among concerned parties will encourage regulatory body to introduce such an idea for more effective regulation with scientific rationality. Additionally the study of bounding accidents can contribute to substantial development for accident management strategy as reprocessing operators. (authors)

  13. Tunable Optical Properties of Metal Nanoparticle Sol-Gel Composites

    Science.gov (United States)

    Smith, David D.; Snow, Lanee A.; Sibille, Laurent; Ignont, Erica

    2001-01-01

    We demonstrate that the linear and non-linear optical properties of sol-gels containing metal nanoparticles are highly tunable with porosity. Moreover, we extend the technique of immersion spectroscopy to inhomogeneous hosts, such as aerogels, and determine rigorous bounds for the average fractional composition of each component, i.e., the porosity of the aerogel, or equivalently, for these materials, the catalytic dispersion. Sol-gels containing noble metal nanoparticles were fabricated and a significant blue-shift in the surface plasmon resonance (SPR) was observed upon formation of an aerogel, as a result of the decrease in the dielectric constant of the matrix upon supercritical extraction of the solvent. However, as a result of chemical interface damping and aggregation this blue-shift does not strictly obey standard effective medium theories. Mitigation of these complications is achieved by avoiding the use of alcohol and by annealing the samples in a reducing atmosphere.

  14. Charging and Heating Dynamics of Nanoparticles in Nonthermal Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Kortshagen, Uwe R.

    2014-08-15

    The focus of this award was to understand the interactions of nanometer-sized particles with ionized gases, also called plasmas. Plasmas are widely used in the fabrication of electronic circuits such as microprocessors and memory devices, in plasma display panels, as well as in medical applications. Recently, these ionized gases are finding applications in the synthesis of advanced nanomaterials with novel properties, which are based on nanometer-sized particulate (nanoparticles) building blocks. As these nanoparticles grow in the plasma environment, they interact with the plasmas species such as electrons and ions which critically determines the nanoparticle properties. The University of Minnesota researchers conducting this project performed numerical simulations and developed analytical models that described the interaction of plasma-bound nanoparticles with the plasma ions. The plasma ions bombard the nanoparticle surface with substantial energy, which can result in the rearrangement of the nanoparticles’ atoms, giving them often desirable structures at the atomic scale. Being able to tune the ion energies allows to control the properties of nanoparticles produced in order to tailor their attributes for certain applications. For instance, when used in high efficiency light emitting devices, nanoparticles produced under high fluxes of highly energetic ions may show superior light emission to particles produced under low fluxes of less energetic ions. The analytical models developed by the University of Minnesota researchers enable the research community to easily determine the energy of ions bombarding the nanoparticles. The researchers extensively tested the validity of the analytical models by comparing them to sophisticated computer simulations based on stochastic particle modeling, also called Monte Carlo modeling, which simulated the motion of hundreds of thousands of ions and their interaction with the nanoparticle surfaces. Beyond the scientific

  15. Direct hierarchical assembly of nanoparticles

    Science.gov (United States)

    Xu, Ting; Zhao, Yue; Thorkelsson, Kari

    2014-07-22

    The present invention provides hierarchical assemblies of a block copolymer, a bifunctional linking compound and a nanoparticle. The block copolymers form one micro-domain and the nanoparticles another micro-domain.

  16. Synthesis of platinum nanoparticles using dried Anacardium occidentale leaf and its catalytic and thermal applications.

    Science.gov (United States)

    Sheny, D S; Philip, Daizy; Mathew, Joseph

    2013-10-01

    An environment friendly approach for the synthesis of Pt nanoparticles (NPs) using dried leaf powder of Anacardium occidentale is reported. The formation of Pt NPs is monitored using UV-Vis spectrophotometer. FTIR spectra reveal that proteins are bound to Pt nanoparticles. TEM images show irregular rod shaped particles which are crystalline. The quantity of leaf powder plays a vital role in determining the size of particles. Synthesized NPs exhibit good catalytic activity in the reduction of aromatic nitrocompound. The effective thermal conductivity of synthesized Pt/water nanofluid has been measured and found to be enhanced to a good extent. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Binding assays with streptavidin-functionalized superparamagnetic nanoparticles and biotinylated analytes using fluxgate magnetorelaxometry

    International Nuclear Information System (INIS)

    Heim, Erik; Ludwig, Frank; Schilling, Meinhard

    2009-01-01

    Binding assays based on the magnetorelaxation of superparamagnetic nanoparticles as markers are presented utilizing a differential fluxgate system. As ligand and receptor, streptavidin and biotin, respectively, are used. Superparamagnetic nanoparticles are functionalized with streptavidin and bound to two types of biotinylated analytes: agarose beads and bovine serum (BSA) proteins. The size difference of the two analytes causes a different progress of the reaction. As a consequence, the analysis of the relaxation signal is carried out dissimilarly for the two analytes. In addition, we studied the reaction kinetics of the two kinds of analytes with the fluxgate system.

  18. On the role of Fe ions on magnetic properties of doped TiO2 nanoparticles

    Science.gov (United States)

    Tolea, F.; Grecu, M. N.; Kuncser, V.; Constantinescu, S. Gr.; Ghica, D.

    2015-04-01

    The role of iron doping on magnetic properties of hydrothermal anatase TiO2:57Fe (0-1 at. %) nanoparticles is investigated by combining superconducting quantum interference device magnetometry with Mössbauer and electron paramagnetic resonance techniques. The results on both as-prepared and thermally treated samples in reduced air atmosphere reveal complexity of magnetic interactions, in connection to certain iron ion electron configurations and defects (oxygen vacancies, F-center, and Ti3+ ions). The distribution of iron ions is predominantly at nanoparticle surface layers. Formation of weak ferromagnetic domains up to 380 K is mainly related to defects, supporting the bound magnetic polaron model.

  19. Effect of fullerenol surface chemistry on nanoparticle binding-induced protein misfolding

    Science.gov (United States)

    Radic, Slaven; Nedumpully-Govindan, Praveen; Chen, Ran; Salonen, Emppu; Brown, Jared M.; Ke, Pu Chun; Ding, Feng

    2014-06-01

    Fullerene and its derivatives with different surface chemistry have great potential in biomedical applications. Accordingly, it is important to delineate the impact of these carbon-based nanoparticles on protein structure, dynamics, and subsequently function. Here, we focused on the effect of hydroxylation -- a common strategy for solubilizing and functionalizing fullerene -- on protein-nanoparticle interactions using a model protein, ubiquitin. We applied a set of complementary computational modeling methods, including docking and molecular dynamics simulations with both explicit and implicit solvent, to illustrate the impact of hydroxylated fullerenes on the structure and dynamics of ubiquitin. We found that all derivatives bound to the model protein. Specifically, the more hydrophilic nanoparticles with a higher number of hydroxyl groups bound to the surface of the protein via hydrogen bonds, which stabilized the protein without inducing large conformational changes in the protein structure. In contrast, fullerene derivatives with a smaller number of hydroxyl groups buried their hydrophobic surface inside the protein, thereby causing protein denaturation. Overall, our results revealed a distinct role of surface chemistry on nanoparticle-protein binding and binding-induced protein misfolding.Fullerene and its derivatives with different surface chemistry have great potential in biomedical applications. Accordingly, it is important to delineate the impact of these carbon-based nanoparticles on protein structure, dynamics, and subsequently function. Here, we focused on the effect of hydroxylation -- a common strategy for solubilizing and functionalizing fullerene -- on protein-nanoparticle interactions using a model protein, ubiquitin. We applied a set of complementary computational modeling methods, including docking and molecular dynamics simulations with both explicit and implicit solvent, to illustrate the impact of hydroxylated fullerenes on the structure and

  20. Polyelectrolyte-modified cowpea mosaic virus for the synthesis of gold nanoparticles.

    Science.gov (United States)

    Aljabali, Alaa A A; Evans, David J

    2014-01-01

    Polyelectrolyte surface-modified cowpea mosaic virus (CPMV) can be used for the templated synthesis of narrowly dispersed gold nanoparticles. Cationic polyelectrolyte, poly(allylamine) hydrochloride, is electrostatically bound to the external surface of the virus capsid. The polyelectrolyte-coated CPMV promotes adsorption of aqueous gold hydroxide anionic species, prepared from gold(III) chloride and potassium carbonate, that are easily reduced to form CPMV-templated gold nanoparticles. The process is simple and environmentally benign using only water as solvent at ambient temperature.

  1. Lanthanide-based NMR: a tool to investigate component distribution in mixed-monolayer-protected nanoparticles.

    Science.gov (United States)

    Guarino, Gaetano; Rastrelli, Federico; Scrimin, Paolo; Mancin, Fabrizio

    2012-05-02

    Gd(3+) ions, once bound to the monolayer of organic molecules coating the surface of gold nanoparticles, produce a paramagnetic relaxation enhancement (PRE) that broadens and eventually cancels the signals of the nuclear spins located nearby (within 1.6 nm distance). In the case of nanoparticles coated with mixed monolayers, the signals arising from the different coating molecules experience different PRE, depending on their distance from the binding site. As a consequence, observation of the signal broadening patterns provides direct information on the monolayer organization. © 2012 American Chemical Society

  2. Detection of Salmonella typhi utilizing bioconjugated fluorescent polymeric nanoparticles

    International Nuclear Information System (INIS)

    Jain, Swati; Chattopadhyay, Sruti; Jackeray, Richa; Abid, Zainul; Singh, Harpal

    2016-01-01

    Present work demonstrates effective utilization of functionalized polymeric fluorescent nanoparticles as biosensing probe for the detection of Salmonella typhi bacteria on modified polycarbonate (PC) filters in about 3 h. Antibody modified-PC membranes were incubated with contaminated bacterial water for selective capturing which were detected by synthesized novel bioconjugate probe. Core–shell architecture of polymeric nanoparticles endows them with aqueous stabilization and keto-enolic functionalities making them usable for covalently linking S. typhi antibodies without any crosslinker or activator. Bradford analysis revealed that one nanoparticle has an average of 3.51 × 10"−"1"9 g or 21 × 10"4 bound S. typhi Ab molecules. Analysis of the regions of interest (ROI) in fluorescent micrographs of modified fluoroimmunoassay showed higher detection sensitivity of 5 × 10"2 cells/mL due to signal amplification unlike conventional naked dye FITC-Ab conjugate. Fluorescence of pyrene dye remained same on immobilization of biomolecules and nanoparticles showed stable fluorescent intensity under prolong exposure to laser owing to protective polymeric layer allowing accurate identification of bacteria. Surface-functionalized PC matrix and fluorescent label NPs permit covalent interactions among biomolecules enhancing signal acquisitions showing higher detection efficiency as compared to conventional microtiter plate-based system. Our novel immunoassay has the potential to be explored as rapid detection method for identifying S. typhi contaminations in water.Graphical Abstract

  3. Detection of Salmonella typhi utilizing bioconjugated fluorescent polymeric nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Swati, E-mail: swatijain.iitd@gmail.com; Chattopadhyay, Sruti, E-mail: sruticiitd@gmail.com; Jackeray, Richa; Abid, Zainul; Singh, Harpal, E-mail: harpal2000@yahoo.com [Centre for Biomedical Engineering, Indian Institute of Technology-Delhi (India)

    2016-05-15

    Present work demonstrates effective utilization of functionalized polymeric fluorescent nanoparticles as biosensing probe for the detection of Salmonella typhi bacteria on modified polycarbonate (PC) filters in about 3 h. Antibody modified-PC membranes were incubated with contaminated bacterial water for selective capturing which were detected by synthesized novel bioconjugate probe. Core–shell architecture of polymeric nanoparticles endows them with aqueous stabilization and keto-enolic functionalities making them usable for covalently linking S. typhi antibodies without any crosslinker or activator. Bradford analysis revealed that one nanoparticle has an average of 3.51 × 10{sup −19} g or 21 × 10{sup 4} bound S. typhi Ab molecules. Analysis of the regions of interest (ROI) in fluorescent micrographs of modified fluoroimmunoassay showed higher detection sensitivity of 5 × 10{sup 2} cells/mL due to signal amplification unlike conventional naked dye FITC-Ab conjugate. Fluorescence of pyrene dye remained same on immobilization of biomolecules and nanoparticles showed stable fluorescent intensity under prolong exposure to laser owing to protective polymeric layer allowing accurate identification of bacteria. Surface-functionalized PC matrix and fluorescent label NPs permit covalent interactions among biomolecules enhancing signal acquisitions showing higher detection efficiency as compared to conventional microtiter plate-based system. Our novel immunoassay has the potential to be explored as rapid detection method for identifying S. typhi contaminations in water.Graphical Abstract.

  4. Resistance of soil-bound prions to rumen digestion.

    Directory of Open Access Journals (Sweden)

    Samuel E Saunders

    Full Text Available Before prion uptake and infection can occur in the lower gastrointestinal system, ingested prions are subjected to anaerobic digestion in the rumen of cervids and bovids. The susceptibility of soil-bound prions to rumen digestion has not been evaluated previously. In this study, prions from infectious brain homogenates as well as prions bound to a range of soils and soil minerals were subjected to in vitro rumen digestion, and changes in PrP levels were measured via western blot. Binding to clay appeared to protect noninfectious hamster PrP(c from complete digestion, while both unbound and soil-bound infectious PrP(Sc proved highly resistant to rumen digestion. In addition, no change in intracerebral incubation period was observed following active rumen digestion of unbound hamster HY TME prions and HY TME prions bound to a silty clay loam soil. These results demonstrate that both unbound and soil-bound prions readily survive rumen digestion without a reduction in infectivity, further supporting the potential for soil-mediated transmission of chronic wasting disease (CWD and scrapie in the environment.

  5. Research on culture-bound syndromes: new directions.

    Science.gov (United States)

    Guarnaccia, P J; Rogler, L H

    1999-09-01

    The unprecedented inclusion of culture-bound syndromes in DSM-IV provides the opportunity for highlighting the need to study such syndromes and the occasion for developing a research agenda to study them. The growing ethnic and cultural diversity of the U.S. population presents a challenge to the mental health field to develop truly cross-cultural approaches to mental health research and services. In this article, the authors provide a critique of previous analyses of the relationship between culture-bound syndromes and psychiatric diagnoses. They highlight the problems in previous classificatory exercises, which tend to focus on subsuming the culture-bound syndromes into psychiatric categories and fail to fully investigate these syndromes on their own terms. A detailed research program based on four key questions is presented both to understand culture-bound syndromes within their cultural context and to analyze the relationship between these syndromes and psychiatric disorders. Results of over a decade of research on ataques de nervios, a Latino-Caribbean cultural syndrome, are used to illustrate this research program. The four questions focus on the nature of the phenomenon, the social-cultural location of sufferers, the relationship of culture-bound syndromes to psychiatric disorders, and the social and psychiatric history of the syndrome in the life course of the sufferer.

  6. Information theoretic bounds for compressed sensing in SAR imaging

    International Nuclear Information System (INIS)

    Jingxiong, Zhang; Ke, Yang; Jianzhong, Guo

    2014-01-01

    Compressed sensing (CS) is a new framework for sampling and reconstructing sparse signals from measurements significantly fewer than those prescribed by Nyquist rate in the Shannon sampling theorem. This new strategy, applied in various application areas including synthetic aperture radar (SAR), relies on two principles: sparsity, which is related to the signals of interest, and incoherence, which refers to the sensing modality. An important question in CS-based SAR system design concerns sampling rate necessary and sufficient for exact or approximate recovery of sparse signals. In the literature, bounds of measurements (or sampling rate) in CS have been proposed from the perspective of information theory. However, these information-theoretic bounds need to be reviewed and, if necessary, validated for CS-based SAR imaging, as there are various assumptions made in the derivations of lower and upper bounds on sub-Nyquist sampling rates, which may not hold true in CS-based SAR imaging. In this paper, information-theoretic bounds of sampling rate will be analyzed. For this, the SAR measurement system is modeled as an information channel, with channel capacity and rate-distortion characteristics evaluated to enable the determination of sampling rates required for recovery of sparse scenes. Experiments based on simulated data will be undertaken to test the theoretic bounds against empirical results about sampling rates required to achieve certain detection error probabilities

  7. Class-specific Error Bounds for Ensemble Classifiers

    Energy Technology Data Exchange (ETDEWEB)

    Prenger, R; Lemmond, T; Varshney, K; Chen, B; Hanley, W

    2009-10-06

    The generalization error, or probability of misclassification, of ensemble classifiers has been shown to be bounded above by a function of the mean correlation between the constituent (i.e., base) classifiers and their average strength. This bound suggests that increasing the strength and/or decreasing the correlation of an ensemble's base classifiers may yield improved performance under the assumption of equal error costs. However, this and other existing bounds do not directly address application spaces in which error costs are inherently unequal. For applications involving binary classification, Receiver Operating Characteristic (ROC) curves, performance curves that explicitly trade off false alarms and missed detections, are often utilized to support decision making. To address performance optimization in this context, we have developed a lower bound for the entire ROC curve that can be expressed in terms of the class-specific strength and correlation of the base classifiers. We present empirical analyses demonstrating the efficacy of these bounds in predicting relative classifier performance. In addition, we specify performance regions of the ROC curve that are naturally delineated by the class-specific strengths of the base classifiers and show that each of these regions can be associated with a unique set of guidelines for performance optimization of binary classifiers within unequal error cost regimes.

  8. Bionic Control of Cheetah Bounding with a Segmented Spine.

    Science.gov (United States)

    Wang, Chunlei; Wang, Shigang

    2016-01-01

    A cheetah model is built to mimic real cheetah and its mechanical and dimensional parameters are derived from the real cheetah. In particular, two joints in spine and four joints in a leg are used to realize the motion of segmented spine and segmented legs which are the key properties of the cheetah bounding. For actuating and stabilizing the bounding gait of cheetah, we present a bioinspired controller based on the state-machine. The controller mainly mimics the function of the cerebellum to plan the locomotion and keep the body balance. The haptic sensor and proprioception system are used to detect the trigger of the phase transition. Besides, the vestibular modulation could perceive the pitching angle of the trunk. At last, the cerebellum acts as the CPU to operate the information from the biological sensors. In addition, the calculated results are transmitted to the low-level controller to actuate and stabilize the cheetah bounding. Moreover, the delay feedback control method is employed to plan the motion of the leg joints to stabilize the pitching motion of trunk with the stability criterion. Finally, the cyclic cheetah bounding with biological properties is realized. Meanwhile, the stability and dynamic properties of the cheetah bounding gait are analyzed elaborately.

  9. A gauged baby Skyrme model and a novel BPS bound

    International Nuclear Information System (INIS)

    Adam, C; Naya, C; Sanchez-Guillen, J; Wereszczynski, A

    2013-01-01

    The baby Skyrme model is a well-known nonlinear field theory supporting topological solitons in two space dimensions. Its action functional consist of a potential term, a kinetic term quadratic in derivatives (the 'nonlinear sigma model term') and the Skyrme term quartic in first derivatives. The limiting case of vanishing sigma model term (the so-called BPS baby Skyrme model) is known to support exact soliton solutions saturating a BPS bound which exists for this model. Further, the BPS model has infinitely many symmetries and conservation laws. Recently it was found that the gauged version of the BPS baby Skyrme model with gauge group U(1) and the usual Maxwell term, too, has a BPS bound and BPS solutions saturating this bound. This BPS bound is determined by a superpotential which has to obey a superpotential equation, in close analogy to the situation in supergravity. Further, the BPS bound and the corresponding BPS solitons only may exist for potentials such that the superpotential equation has a global solution. We also briefly describe some properties of soliton solutions.

  10. Bounding the space of holographic CFTs with chaos

    Energy Technology Data Exchange (ETDEWEB)

    Perlmutter, Eric [Department of Physics, Princeton University,Jadwin Hall, Princeton, NJ 08544 (United States)

    2016-10-13

    Thermal states of quantum systems with many degrees of freedom are subject to a bound on the rate of onset of chaos, including a bound on the Lyapunov exponent, λ{sub L}≤2π/β. We harness this bound to constrain the space of putative holographic CFTs and their would-be dual theories of AdS gravity. First, by studying out-of-time-order four-point functions, we discuss how λ{sub L}=2π/β in ordinary two-dimensional holographic CFTs is related to properties of the OPE at strong coupling. We then rule out the existence of unitary, sparse two-dimensional CFTs with large central charge and a set of higher spin currents of bounded spin; this implies the inconsistency of weakly coupled AdS{sub 3} higher spin gravities without infinite towers of gauge fields, such as the SL(N) theories. This fits naturally with the structure of higher-dimensional gravity, where finite towers of higher spin fields lead to acausality. On the other hand, unitary CFTs with classical W{sub ∞}[λ] symmetry, dual to 3D Vasiliev or hs[λ] higher spin gravities, do not violate the chaos bound, instead exhibiting no chaos: λ{sub L}=0. Independently, we show that such theories violate unitarity for |λ|>2. These results encourage a tensionless string theory interpretation of the 3D Vasiliev theory.

  11. Reply to ''Limitation on numerical bounds on transition probabilities''

    International Nuclear Information System (INIS)

    Storm, D.

    1975-01-01

    It is demonstrated that a good share of the error Shakeshaft attributes to the failure to account for ionization in customary impact-parameter calculations for proton--hydrogen-atom scattering amplitudes really results from the inadequacy of the traveling hydrogenic basis set to account for the dynamic polarization of the hydrogen atom by the moving proton. The lower limit for the first-order bound can be reduced by using hydrogenlike basis functions that allow for this polarization. Bounds on the cross sections obtained by using the bound Δ 1 need not be infinite. The inclusion of time-dependent adjustable parameters in the basis functions provides a method for modifying the projection of the deviation vector or error term in the Schroedinger equation in the continuum. The exploratory work of Storm and Rapp appears to offer hope that reasonably accurate bounds on at least the 1s charge-exchange amplitudes and cross sections can be obtained by employing only square-integrable basis functions that contain time-dependent variable parameters. However, if it is necessary to account for the flux in the ionization channels, it is shown that an account could be made without the bound becoming infinite

  12. Resistance of Soil-Bound Prions to Rumen Digestion

    Science.gov (United States)

    Saunders, Samuel E.; Bartelt-Hunt, Shannon L.; Bartz, Jason C.

    2012-01-01

    Before prion uptake and infection can occur in the lower gastrointestinal system, ingested prions are subjected to anaerobic digestion in the rumen of cervids and bovids. The susceptibility of soil-bound prions to rumen digestion has not been evaluated previously. In this study, prions from infectious brain homogenates as well as prions bound to a range of soils and soil minerals were subjected to in vitro rumen digestion, and changes in PrP levels were measured via western blot. Binding to clay appeared to protect noninfectious hamster PrPc from complete digestion, while both unbound and soil-bound infectious PrPSc proved highly resistant to rumen digestion. In addition, no change in intracerebral incubation period was observed following active rumen digestion of unbound hamster HY TME prions and HY TME prions bound to a silty clay loam soil. These results demonstrate that both unbound and soil-bound prions readily survive rumen digestion without a reduction in infectivity, further supporting the potential for soil-mediated transmission of chronic wasting disease (CWD) and scrapie in the environment. PMID:22937149

  13. Analysis of a convenient information bound for general quantum channels

    International Nuclear Information System (INIS)

    O'Loan, C J

    2007-01-01

    Open questions from Sarovar and Milburn (2006 J. Phys. A: Math. Gen. 39 8487) are answered. Sarovar and Milburn derived a convenient upper bound for the Fisher information of a one-parameter quantum channel. They showed that for quasi-classical models their bound is achievable and they gave a necessary and sufficient condition for positive operator-valued measures (POVMs) attaining this bound. They asked (i) whether their bound is attainable more generally (ii) whether explicit expressions for optimal POVMs can be derived from the attainability condition. We show that the symmetric logarithmic derivative (SLD) quantum information is less than or equal to the SM bound, i.e., H(θ) ≤ C Y (θ) and we find conditions for equality. As the Fisher information is less than or equal to the SLD quantum information, i.e., F M (θ) ≤ H(θ), we can deduce when equality holds in F M (θ) ≤ C Y (θ). Equality does not hold for all channels. As a consequence, the attainability condition cannot be used to test for optimal POVMs for all channels. These results are extended to multi-parameter channels

  14. Information-Theoretic Bounded Rationality and ε-Optimality

    Directory of Open Access Journals (Sweden)

    Daniel A. Braun

    2014-08-01

    Full Text Available Bounded rationality concerns the study of decision makers with limited information processing resources. Previously, the free energy difference functional has been suggested to model bounded rational decision making, as it provides a natural trade-off between an energy or utility function that is to be optimized and information processing costs that are measured by entropic search costs. The main question of this article is how the information-theoretic free energy model relates to simple ε-optimality models of bounded rational decision making, where the decision maker is satisfied with any action in an ε-neighborhood of the optimal utility. We find that the stochastic policies that optimize the free energy trade-off comply with the notion of ε-optimality. Moreover, this optimality criterion even holds when the environment is adversarial. We conclude that the study of bounded rationality based on ε-optimality criteria that abstract away from the particulars of the information processing constraints is compatible with the information-theoretic free energy model of bounded rationality.

  15. Bionic Control of Cheetah Bounding with a Segmented Spine

    Directory of Open Access Journals (Sweden)

    Chunlei Wang

    2016-01-01

    Full Text Available A cheetah model is built to mimic real cheetah and its mechanical and dimensional parameters are derived from the real cheetah. In particular, two joints in spine and four joints in a leg are used to realize the motion of segmented spine and segmented legs which are the key properties of the cheetah bounding. For actuating and stabilizing the bounding gait of cheetah, we present a bioinspired controller based on the state-machine. The controller mainly mimics the function of the cerebellum to plan the locomotion and keep the body balance. The haptic sensor and proprioception system are used to detect the trigger of the phase transition. Besides, the vestibular modulation could perceive the pitching angle of the trunk. At last, the cerebellum acts as the CPU to operate the information from the biological sensors. In addition, the calculated results are transmitted to the low-level controller to actuate and stabilize the cheetah bounding. Moreover, the delay feedback control method is employed to plan the motion of the leg joints to stabilize the pitching motion of trunk with the stability criterion. Finally, the cyclic cheetah bounding with biological properties is realized. Meanwhile, the stability and dynamic properties of the cheetah bounding gait are analyzed elaborately.

  16. On Landauer's Principle and Bound for Infinite Systems

    Science.gov (United States)

    Longo, Roberto

    2018-04-01

    Landauer's principle provides a link between Shannon's information entropy and Clausius' thermodynamical entropy. Here we set up a basic formula for the incremental free energy of a quantum channel, possibly relative to infinite systems, naturally arising by an Operator Algebraic point of view. By the Tomita-Takesaki modular theory, we can indeed describe a canonical evolution associated with a quantum channel state transfer. Such evolution is implemented both by a modular Hamiltonian and a physical Hamiltonian, the latter being determined by its functoriality properties. This allows us to make an intrinsic analysis, extending our QFT index formula, but without any a priori given dynamics; the associated incremental free energy is related to the logarithm of the Jones index and is thus quantised. This leads to a general lower bound for the incremental free energy of an irreversible quantum channel which is half of the Landauer bound, and to further bounds corresponding to the discrete series of the Jones index. In the finite dimensional context, or in the case of DHR charges in QFT, where the dimension is a positive integer, our lower bound agrees with Landauer's bound.

  17. Polymeric gel nanoparticle pH sensors for intracellular measurements

    OpenAIRE

    Almdal, Kristoffer; Andresen, Thomas Lars; Benjaminsen, Rikke Vicki; Christensen, Nynne Meyn; Henriksen, Jonas Rosager; Sun, Honghao

    2011-01-01

    Precise measurements of pH in cells and intracellular compartments are of importance to both the fundamental understanding of metabolism and to the development of drugs that are released from the endosomes-lysome pathway. We have developed polymer gel nanoparticles as carriers of covalently bound fluorophores for ratiometric measurements of pH. One pH insensitive fluorophore serves as a reference while one or more pH sensitive fluorophores serve to give the desired pH dependence of the output...

  18. Glyconanobiotics: Novel carbohydrated nanoparticle antibiotics for MRSA and Bacillus anthracis

    OpenAIRE

    Abeylath, Sampath C.; Turos, Edward; Dickey, Sonja; Limb, Daniel V.

    2007-01-01

    This report describes the synthesis and evaluation of glycosylated polyacrylate nanoparticles that have covalently-bound antibiotics within their framework. The requisite glycosylated drug monomers were prepared from one of three known antibiotics, an N-sec-butylthio β-lactam, ciprofloxacin, and a penicillin, by acylation with 3-O-acryloyl-1,2-O-isopropylidene-5,6 bis((chlorosuccinyl)oxy)-D-glucofuranose (7) or 6-O-acetyl-3-O-acryloyl-1,2-O-isopropylidene-5-(chlorosuccinyl)oxy-α-D-glucofurano...

  19. Lactobacillusassisted synthesis of titanium nanoparticles

    Directory of Open Access Journals (Sweden)

    Jha Anal

    2007-01-01

    Full Text Available AbstractAn eco-friendlylactobacillussp. (microbe assisted synthesis of titanium nanoparticles is reported. The synthesis is performed at room temperature. X-ray and transmission electron microscopy analyses are performed to ascertain the formation of Ti nanoparticles. Individual nanoparticles as well as a number of aggregates almost spherical in shape having a size of 40–60 nm are found.

  20. Gold Nanoparticle Microwave Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Krantz, Kelsie E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Christian, Jonathan H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Coopersmith, Kaitlin [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Washington, II, Aaron L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Murph, Simona H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-07-27

    At the nanometer scale, numerous compounds display different properties than those found in bulk material that can prove useful in areas such as medicinal chemistry. Gold nanoparticles, for example, display promise in newly developed hyperthermia therapies for cancer treatment. Currently, gold nanoparticle synthesis is performed via the hot injection technique which has large variability in final particle size and a longer reaction time. One underdeveloped area by which these particles could be produced is through microwave synthesis. To initiate heating, microwaves agitate polar molecules creating a vibration that gives off the heat energy needed. Previous studies have used microwaves for gold nanoparticle synthesis; however, polar solvents were used that partially absorbed incident microwaves, leading to partial thermal heating of the sample rather than taking full advantage of the microwave to solely heat the gold nanoparticle precursors in a non-polar solution. Through this project, microwaves were utilized as the sole heat source, and non-polar solvents were used to explore the effects of microwave heating only as pertains to the precursor material. Our findings show that the use of non-polar solvents allows for more rapid heating as compared to polar solvents, and a reduction in reaction time from 10 minutes to 1 minute; this maximizes the efficiency of the reaction, and allows for reproducibility in the size/shape of the fabricated nanoparticles.