Basis for low beam loss in the high-current APT linac

International Nuclear Information System (INIS)

Wangler, T.P.; Gray, E.R.; Krawczyk, F.L.; Kurennoy, S.S.; Lawrence, G.P.; Ryne, R.D.; Crandall, K.R.

1998-01-01

The present evidence that the APT proton linac design will meet its goal of low beam loss operation. The conclusion has three main bases: (1) extrapolation from the understanding of the performance of the 800-MeV LANSCE proton linac at Los Alamos, (2) the theoretical understanding of the dominant halo-forming mechanism in the APT accelerator from physics models and multiparticle simulations, and (3) the conservative approach and key principles underlying the design of the APT linac, which are aimed at minimizing beam halo and providing large apertures to reduce beam loss to a very low value

Testing APT Model upon a BVB Stocks’ Portfolio

Directory of Open Access Journals (Sweden)

Alexandra BONTAŞ

2011-01-01

Full Text Available Applying the Arbitrage Pricing Theory model (APT, there can be identified the major factors of influence for a BVB’ portfolio stocks' trend. There were taken into consideration two of the APT theory models, establishing influences upon portfolio's yield: given to macroeconomic environment and to some stochastic factors. The researchs results certify that, on the long term, what influences the stocks’ movement in the stock market is mostly the action of specific short-term factors, without general covering, like the ones that are classified in the research area of behavioral finance (investors’ preference towards risk and towards time.

Identifying APT Malware Domain Based on Mobile DNS Logging

Directory of Open Access Journals (Sweden)

Weina Niu

2017-01-01

Full Text Available Advanced Persistent Threat (APT is a serious threat against sensitive information. Current detection approaches are time-consuming since they detect APT attack by in-depth analysis of massive amounts of data after data breaches. Specifically, APT attackers make use of DNS to locate their command and control (C&C servers and victims’ machines. In this paper, we propose an efficient approach to detect APT malware C&C domain with high accuracy by analyzing DNS logs. We first extract 15 features from DNS logs of mobile devices. According to Alexa ranking and the VirusTotal’s judgement result, we give each domain a score. Then, we select the most normal domains by the score metric. Finally, we utilize our anomaly detection algorithm, called Global Abnormal Forest (GAF, to identify malware C&C domains. We conduct a performance analysis to demonstrate that our approach is more efficient than other existing works in terms of calculation efficiency and recognition accuracy. Compared with Local Outlier Factor (LOF, k-Nearest Neighbor (KNN, and Isolation Forest (iForest, our approach obtains more than 99% F-M and R for the detection of C&C domains. Our approach not only can reduce data volume that needs to be recorded and analyzed but also can be applicable to unsupervised learning.

Thermal analysis of the APT materials irradiation samples

International Nuclear Information System (INIS)

Maloy, S.A.; Willcutt, G.J.; James, M.R.; Teague, J.; Diebe, D.A.; Sommer, W.F.; Ferguson, P.D.

1998-01-01

The accelerator production of tritium (APT) project proposes to use a 1.7 GeV, 100 mA proton beam to produce neutrons from an Inconel 718 clad tungsten target. The neutrons are multiplied and moderated in a lead/water blanket before being captured in He 3 to form tritium. In this process, the materials in the target and blanket region are exposed to a wide range of different fluxes comprised of protons and neutrons with energies into the GeV range. To investigate the effect of irradiation on the mechanical properties of candidate APT materials (Inconel 718, 316L stainless steel, Al 6061-T6, Mod 9Cr-1Mo, 304L stainless steel and Al5052-0), the APT Engineering Design and Development group fielded an extensive materials irradiation using the LANSCE (Los Alamos Neutron Science Center) accelerator, which operates at an energy of 800 MeV and a current of 1 mA. The test set-up was designed to place mechanical test specimens in locations in and near the proton beam where the environment of proton and neutron fluxes and temperatures are prototypic to those expected in the APT target/blanket (50--170 C). After irradiating for about 3,600 hours, the maximum achieved proton fluence was 4--5 x 10 21 p/cm 2 for the materials in the center of the beam. To obtain relevant data on the change in the mechanical properties with fluence, it is essential to know the temperature at which the materials were irradiated. This paper explains the method of determining the specimen temperature and reports some specific examples

Potassium hydroxide: an alternative reagent to perform the modified apt test.

Science.gov (United States)

Chicaiza, Henry; Hellstrand, Karl; Lerer, Trudy; Smith, Sharon; Sylvester, Francisco

2014-09-01

We tested the performance of potassium hydroxide (KOH) in the modified Apt test under different experimental conditions using sodium hydroxide as a positive control. Like sodium hydroxide, KOH differentiated fresh fetal and adult blood stains on a cloth but not dried blood. KOH may be used to perform the Apt test at the bedside. Copyright © 2014 Elsevier Inc. All rights reserved.

Technical memorandum: instrumentation for APT and LTPP

CSIR Research Space (South Africa)

Steyn, WJvdM

2006-01-01

Full Text Available . In these phases, the parameters to be monitored on APT and LTPP sections have been identified, appropriate instruments and sensors for monitoring these parameters have been identified, and recommendations made regarding new developments, required upgrading...

APT and CEST Techniques for Clinical MRI

NARCIS (Netherlands)

Keupp, J.

2011-01-01

Chemical exchange saturation transfer (CEST) based in vivo detectionand quantification of endogenous macro-molecules (i.e., amide proton transfer, APT) or exogenous contrast agents is a highly sensitivemolecular MRI technique bearing a substantial clinical potential forexample in oncology or for

Superconducting cavities for the APT accelerator

International Nuclear Information System (INIS)

Krawczyk, F.L.; Gentzlinger, R.C.; Haynes, B.; Montoya, D.I.; Rusnak, B.; Shapiro, A.H.

1997-01-01

The design of an Accelerator Production of Tritium (APT) facility being investigated at Los Alamos includes a linear accelerator using superconducting rf-cavities for the acceleration of a high-current cw proton beam. For electron accelerators with particles moving at the speed of light (β ∼ 1.0), resonators with a rounded shape, consisting of ellipsoidal and cylindrical sections, are well established. They are referred to as elliptical cavities. For the APT-design, this shape has been adapted for much slower proton beams with β ranging from 0.60 to 0.94. This is a new energy range, in which resonators of an elliptical type have never been used before. Simulations with the well-proven electromagnetic modeling tools MAFIA and SUPERFISH were performed. The structures have been optimized for their rf and mechanical properties as well as for beam dynamics requirements. The TRAK-RF simulation code is used to investigate potential multipacting in these structures. All the simulations will be put to a final test in experiments performed on single cell cavities that have started in the structures laboratory

Miniaturization of the atmospheric laser communication APT system

Science.gov (United States)

Sun, Wei; Ai, Yong; Yang, Jinling; Huang, Haibo

2003-09-01

The paper presents a scheme of the miniaturization of APT system and the design of the system based on the investigation of status in quo. It deals with the infrared image of the other terminal's beacon from the Charge Coupled Device (CCD) by the Complex Programmable Logic Device (CPLD). The result of the transaction is delivered to Single Chip Microcomputer (SCM), which controls the micro-servomotor. Subsequently, the precision drive system drives the optical system that uses only one light axis for signal beam and beacon to finish the acquisition, pointing, and tracking of the communication terminals. The anlayses of the APT system's error indicate that the tracking error limits in 70uRad with the weight of the system lighter than 8-kilogram.

Medical Isotope Production With The Accelerator Production of Tritium (APT) Facility

International Nuclear Information System (INIS)

Buckner, M.; Cappiello, M.; Pitcher, E.; O'Brien, H.

1998-01-01

In order to meet US tritium needs to maintain the nuclear weapons deterrent, the Department of Energy (DOE) is pursuing a dual track program to provide a new tritium source. A record of decision is planned for late in 1998 to select either the Accelerator Production of Tritium (APT) or the Commercial Light Water Reactor (CLWR) as the technology for new tritium production in the next century. To support this decision, an APT Project was undertaken to develop an accelerator design capable of producing 3 kg of tritium per year by 2007 (START I requirements). The Los Alamos National Laboratory (LANL) was selected to lead this effort with Burns and Roe Enterprises, Inc. (BREI) / General Atomics (GA) as the prime contractor for design, construction, and commissioning of the facility. If chosen in the downselect, the facility will be built at the Savannah River Site (SRS) and operated by the SRS Maintenance and Operations (M ampersand O) contractor, the Westinghouse Savannah River Company (WSRC), with long-term technology support from LANL. These three organizations (LANL, BREI/GA, and WSRC) are working together under the direction of the APT National Project Office which reports directly to the DOE Office of Accelerator Production which has program authority and responsibility for the APT Project

Molecular layer deposition of APTES on silicon nanowire biosensors: Surface characterization, stability and pH response

International Nuclear Information System (INIS)

Liang, Yuchen; Huang, Jie; Zang, Pengyuan; Kim, Jiyoung; Hu, Walter

2014-01-01

Graphical abstract: - Abstract: We report the use of molecular layer deposition (MLD) for depositing 3-aminopropyltriethoxysilane (APTES) on a silicon dioxide surface. The APTES monolayer was characterized using spectroscopic ellipsometry, contact angle goniometry, and atomic force microscopy. Effects of reaction time of repeating pulses and simultaneous feeding of water vapor with APTES were tested. The results indicate that the synergistic effects of water vapor and reaction time are significant for the formation of a stable monolayer. Additionally, increasing the number of repeating pulses improved the APTES surface coverage but led to saturation after 10 pulses. In comparing MLD with solution-phase deposition, the APTES surface coverage and the surface quality were nearly equivalent. The hydrolytic stability of the resulting films was also studied. The results confirmed that the hydrolysis process was necessary for MLD to obtain stable surface chemistry. Furthermore, we compared the pH sensing results of Si nanowire field effect transistors (Si NWFETs) modified by both the MLD and solution methods. The highly repeatable pH sensing results reflected the stability of APTES monolayers. The results also showed an improved pH response of the sensor prepared by MLD compared to the one prepared by the solution treatment, which indicated higher surface coverage of APTES

Molecular layer deposition of APTES on silicon nanowire biosensors: Surface characterization, stability and pH response

Science.gov (United States)

Liang, Yuchen; Huang, Jie; Zang, Pengyuan; Kim, Jiyoung; Hu, Walter

2014-12-01

We report the use of molecular layer deposition (MLD) for depositing 3-aminopropyltriethoxysilane (APTES) on a silicon dioxide surface. The APTES monolayer was characterized using spectroscopic ellipsometry, contact angle goniometry, and atomic force microscopy. Effects of reaction time of repeating pulses and simultaneous feeding of water vapor with APTES were tested. The results indicate that the synergistic effects of water vapor and reaction time are significant for the formation of a stable monolayer. Additionally, increasing the number of repeating pulses improved the APTES surface coverage but led to saturation after 10 pulses. In comparing MLD with solution-phase deposition, the APTES surface coverage and the surface quality were nearly equivalent. The hydrolytic stability of the resulting films was also studied. The results confirmed that the hydrolysis process was necessary for MLD to obtain stable surface chemistry. Furthermore, we compared the pH sensing results of Si nanowire field effect transistors (Si NWFETs) modified by both the MLD and solution methods. The highly repeatable pH sensing results reflected the stability of APTES monolayers. The results also showed an improved pH response of the sensor prepared by MLD compared to the one prepared by the solution treatment, which indicated higher surface coverage of APTES.

Biomedical applications of SPION@APTES@PEG-folic acid@carboxylated quercetin nanodrug on various cancer cells

International Nuclear Information System (INIS)

Akal, Z.Ü.; Alpsoy, L.; Baykal, A.

2016-01-01

Highlights: • SPION has been synthesized via Reflux synthesis route. • SPION@APTES@FA-PEG@CQ nanodrug has super paramagnetic property. • SPION@APTES@FA-PEG@CQ nanodrug has cytotoxic, apoptotic and necrotic effects on HeLa and MCF-7 cells. • SPION@APTES@FA-PEG@CQ nanodrug can be potentially used for the delivery of quercetin to cervical and breast cancer cells. - Abstract: In this study, carboxylated quercetin (CQ) was conjugated to superparamagnetic iron oxide nanoparticles (SPIONs) which were modified by (3-aminopropyl) triethoxysilane (APTES), Folic acid (FA) and carboxylated Polyethylene glycol (PEG); (SPION@APTES@FA-PEG@CQ), nanodrug has been synthesized via polyol and accompanying by various chemical synthesis routes. The characterization of the final product was done via X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermal gravimetric analysis (TGA), Transmission electron spectroscopy (TEM) and Vibrating sample magnetometer (VSM). Its cytotoxic and apoptotic activities on over expressed folic acid receptor (FR + ) (MCF-7, HeLa) and none expressed folic acid receptor (FR-) (A549) cancer cell lines were determined by using MTT assay, Real-Time Cell Analysis, TUNEL assay, Annexin assay and RT-PCR analysis for Caspase3/7 respectively. SPION@APTES@FA-PEG@CQ nanodrug showed higher cytotoxicity against HeLa and MCF-7 cell lines as compared with A549 cell line. Moreover, SPION@APTES@FA-PEG@CQ nanodrug also caused higher apoptotic and necrotic effects in 100 μg/mL HeLa and MCF-7 cells than A549 cells. The findings showed that SPION@APTES@FA-PEG@CQ nanodrug has cytotoxic, apoptotic and necrotic effects on HeLa and MCF-7 which are FR over expressed cell lines and can be potentially used for the delivery of quercetin to cervical and breast cancer cells.

Biomedical applications of SPION@APTES@PEG-folic acid@carboxylated quercetin nanodrug on various cancer cells

Energy Technology Data Exchange (ETDEWEB)

Akal, Z.Ü., E-mail: zulker@fatih.edu.tr [Department of Biology, 34500 Büyükçekmece, Istanbul (Turkey); Alpsoy, L. [Department of Biology, 34500 Büyükçekmece, Istanbul (Turkey); Department of Medical Biology, 34500 Büyükçekmece, Istanbul (Turkey); Baykal, A. [Department of Chemistry, Fatih University, 34500 Büyükçekmece, Istanbul (Turkey)

2016-08-15

Highlights: • SPION has been synthesized via Reflux synthesis route. • SPION@APTES@FA-PEG@CQ nanodrug has super paramagnetic property. • SPION@APTES@FA-PEG@CQ nanodrug has cytotoxic, apoptotic and necrotic effects on HeLa and MCF-7 cells. • SPION@APTES@FA-PEG@CQ nanodrug can be potentially used for the delivery of quercetin to cervical and breast cancer cells. - Abstract: In this study, carboxylated quercetin (CQ) was conjugated to superparamagnetic iron oxide nanoparticles (SPIONs) which were modified by (3-aminopropyl) triethoxysilane (APTES), Folic acid (FA) and carboxylated Polyethylene glycol (PEG); (SPION@APTES@FA-PEG@CQ), nanodrug has been synthesized via polyol and accompanying by various chemical synthesis routes. The characterization of the final product was done via X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermal gravimetric analysis (TGA), Transmission electron spectroscopy (TEM) and Vibrating sample magnetometer (VSM). Its cytotoxic and apoptotic activities on over expressed folic acid receptor (FR + ) (MCF-7, HeLa) and none expressed folic acid receptor (FR-) (A549) cancer cell lines were determined by using MTT assay, Real-Time Cell Analysis, TUNEL assay, Annexin assay and RT-PCR analysis for Caspase3/7 respectively. SPION@APTES@FA-PEG@CQ nanodrug showed higher cytotoxicity against HeLa and MCF-7 cell lines as compared with A549 cell line. Moreover, SPION@APTES@FA-PEG@CQ nanodrug also caused higher apoptotic and necrotic effects in 100 μg/mL HeLa and MCF-7 cells than A549 cells. The findings showed that SPION@APTES@FA-PEG@CQ nanodrug has cytotoxic, apoptotic and necrotic effects on HeLa and MCF-7 which are FR over expressed cell lines and can be potentially used for the delivery of quercetin to cervical and breast cancer cells.

Investigation and Prediction of RF Window Performance in APT Accelerators

International Nuclear Information System (INIS)

Humphries, S. Jr.

1997-01-01

The work described in this report was performed between November 1996 and May 1997 in support of the APT (Accelerator Production of Tritium) Program at Los Alamos National Laboratory. The goal was to write and to test computer programs for charged particle orbits in RF fields. The well-documented programs were written in portable form and compiled for standard personal computers for easy distribution to LANL researchers. They will be used in several APT applications including the following. Minimization of multipactor effects in the moderate β superconducting linac cavities under design for the APT accelerator. Investigation of suppression techniques for electron multipactoring in high-power RF feedthroughs. Modeling of the response of electron detectors for the protection of high power RF vacuum windows. In the contract period two new codes, Trak-RF and WaveSim, were completed and several critical benchmark etests were carried out. Trak-RF numerically tracks charged particle orbits in combined electrostatic, magnetostatic and electromagnetic fields. WaveSim determines frequency-domain RF field solutions and provides a key input to Trak-RF. The two-dimensional programs handle planar or cylindrical geometries. They have several unique characteristics

APT/LEDA RFQ and support frame structural analysis

International Nuclear Information System (INIS)

Ellis, S.

1997-01-01

This report documents structural analysis of the Accelerator Production of Tritium Low Energy Demonstration Accelerator (APT/LEDA) Radio Frequency Quadrupole (RFQ) accelerator structure and its associated support frame. This work was conducted for the Department of Energy in support of the APT/LEDA. Structural analysis of the RFQ was performed to quantify stress levels and deflections due to both vacuum loading and gravity loading. This analysis also verified the proposed support scheme geometry and quantified interface loads. This analysis also determined the necessary stiffness and strength requirements of the RFQ support frame verifying the conceptual design geometry and allowing specification of individual frame elements. Complete structural analysis of the frame was completed subsequently. This report details structural analysis of the RFQ assembly with regard to gravity and vacuum loads only. Thermally induced stresses from the Radio Frequency (RF) surface resistance heating were not considered

Aptámeros: agentes diagnósticos y terapéuticos = Aptamers: diagnostic and therapeutic agents

Directory of Open Access Journals (Sweden)

Frank J Hernandez

2012-04-01

Full Text Available Los aptámeros son ácidos nucleicos de cadena sencilla, ADN o ARN, que reconocen una gran variedad de moléculas. Cada aptámero posee una estructura tridimensional particular que le permite unirse con afinidad y especificidad altas a la molécula diana. Los aptámeros tienen propiedades de reconocimiento equiparables a las de los anticuerpos; sin embargo, por la naturaleza de su composición tienen ventajas significativas en cuanto a su tamaño, producción y modificación. Estas características los hacen excelentes candidatos para el desarrollo de nuevas plataformas biotecnológicas. Se han identificado aptámeros con propiedades terapéuticas que han sido evaluados exitosamente en modelos animales; entre ellos, algunos se encuentran en fase clínica y uno ya fue aprobado para tratamiento por la FDA (Food and Drug Administration. Todos estos avances ocurridos durante las dos últimas décadas permiten anticipar el protagonismo que tendrán los aptámeros como agentes diagnósticos y terapéuticos en un futuro cercano.

Defining clusters in APT reconstructions of ODS steels.

Science.gov (United States)

Williams, Ceri A; Haley, Daniel; Marquis, Emmanuelle A; Smith, George D W; Moody, Michael P

2013-09-01

Oxide nanoclusters in a consolidated Fe-14Cr-2W-0.3Ti-0.3Y₂O₃ ODS steel and in the alloy powder after mechanical alloying (but before consolidation) are investigated by atom probe tomography (APT). The maximum separation method is a standard method to define and characterise clusters from within APT data, but this work shows that the extent of clustering between the two materials is sufficiently different that the nanoclusters in the mechanically alloyed powder and in the consolidated material cannot be compared directly using the same cluster selection parameters. As the cluster selection parameters influence the size and composition of the clusters significantly, a procedure to optimise the input parameters for the maximum separation method is proposed by sweeping the d(max) and N(min) parameter space. By applying this method of cluster parameter selection combined with a 'matrix correction' to account for trajectory aberrations, differences in the oxide nanoclusters can then be reliably quantified. Copyright © 2012 Elsevier B.V. All rights reserved.

APT, The Phase I tool for HST Cycle 12

Science.gov (United States)

Blacker, Brett S.; Bertch, Maria; Curtis, Gary; Douglas, Robert E., Jr.; Krueger, Anthony P.

2002-12-01

In the continuing effort to streamline our systems and improve service to the science community, the Space Telescope Science Institute (STScI) is developing and releasing, APT The Astronomer’s Proposal Tool as the new interface for Hubble Space Telescope (HST) Phase I and Phase II proposal submissions for HST Cycle 12. APT, was formerly called the Scientist’s Expert Assistant (SEA), which started as a prototype effort to try and bring state of the art technology, more visual tools and power into the hands of proposers so that they can optimize the scientific return of their programs as well as HST. Proposing for HST and other missions, consists of requesting observing time and/or archival research funding. This step is called Phase I, where the scientific merit of a proposal is considered by a community based peer-review process. Accepted proposals then proceed thru Phase II, where the observations are specified in sufficient detail to enable scheduling on the telescope. In this paper, we will present our concept and implementation plans for our Phase I development and submission tool, APT. More importantly, we will go behind the scenes and discuss why it’s important for the Science Policies Division (SPD) and other groups at the STScI to have a new submission tool and submission output products. This paper is an update of the status of the HST Phase I Proposal Processing System that was described in the published paper “A New Era for HST Phase I Development and Submission.”

Characterization of Botrytis cinerea isolates from chickpea: DNA ...

African Journals Online (AJOL)

Characterization of Botrytis cinerea isolates from chickpea: DNA polymorphisms, cultural, morphological and virulence characteristics. Suresh Pande, Mamta Sharma, G. Krishna Kishore, L. Shivram, U. Naga Mangala ...

The aptness of knowledge related metaphors: a research agenda

NARCIS (Netherlands)

Dr. Daan Andriessen

2010-01-01

Metaphors are common phenomena intellectual capital and knowledge management theories and practice. An important question to ask is: what are the ‗best‘ metaphors we can use in our theorizing on intellectual capital and knowledge management? This paper addresses the question of the aptness of

The Analysis of Income Per Capita Convergence on ASEAN Plus Three (APT) Countries

OpenAIRE

Fatiwetunusa, Any; Syamsurijal, Syamsurijal; Yuliana, Sa’adah

2017-01-01

The main objective of this study is to test the convergence of income per capita in APT countries through three models: absolute convergence, conditional convergence and sigma convergence. Regression analysis of panel data from 13 APT countries during the period of 2001-2014 is used to analysed to study problem. In absolute convergence model, the growth of real GDP per capita and initial real GDP are used as the variables, meanwhile, 8 variables such as the growth of real GPD per capita, init...

Modification of silicon nitride surfaces with GOPES and APTES for antibody immobilization: computational and experimental studies

International Nuclear Information System (INIS)

To, Thien Dien; Nguyen, Anh Tuan; Phan, Khoa Nhat Thanh; Truong, An Thu Thi; Doan, Tin Chanh Duc; Dang, Chien Mau

2015-01-01

Chemical modification of silicon nitride (SiN) surfaces by silanization has been widely studied especially with 3-(aminopropyl)triethoxysilane (APTES) and 3-(glycidyloxypropyl) dimethylethoxysilane (GOPES). However few reports performed the experimental and computational studies together. In this study, surface modification of SiN surfaces with GOPES and APTES covalently bound with glutaraldehyde (GTA) was investigated for antibody immobilization. The monoclonal anti-cytokeratin-FITC (MACF) antibody was immobilized on the modified SiN surfaces. The modified surfaces were characterized by water contact angle measurements, atomic force microscopy and fluorescence microscopy. The FITC-fluorescent label indicated the existence of MACF antibody on the SiN surfaces and the efficiency of the silanization reaction. Absorption of APTES and GOPES on the oxidized SiN surfaces was computationally modeled and calculated by Materials Studio software. The computational and experimental results showed that modification of the SiN surfaces with APTES and GTA was more effective than the modification with GOPES. (paper)

Evaluation of medical isotope production with the accelerator production of tritium (APT) facility

International Nuclear Information System (INIS)

Benjamin, R.W.; Frey, G.D.; McLean, D.C., Jr; Spicer, K.M.; Davis, S.E.; Baron, S.; Frysinger, J.R.; Blanpied, G.; Adcock, D.

1997-01-01

The accelerator production of tritium (APT) facility, with its high beam current and high beam energy, would be an ideal supplier of radioisotopes for medical research, imaging, and therapy. By-product radioisotopes will be produced in the APT window and target cooling systems and in the tungsten target through spallation, neutron, and proton interactions. High intensity proton fluxes are potentially available at three different energies for the production of proton- rich radioisotopes. Isotope production targets can be inserted into the blanket for production of neutron-rich isotopes. Currently, the major production sources of radioisotopes are either aging or abroad, or both. The use of radionuclides in nuclear medicine is growing and changing, both in terms of the number of nuclear medicine procedures being performed and in the rapidly expanding range of procedures and radioisotopes used. A large and varied demand is forecast, and the APT would be an ideal facility to satisfy that demand

Update on the methodology for Amtrak cost accounting Amtrak performance tracking (APT) : volume 2, appendices A-F.

Science.gov (United States)

2016-04-22

Each table below represents the list of Cost Centers associated with each APT Subfamily at the time the data for this report was gathered from APT in April 2016. The #701 Capital Family is not included as it does not have Cost Centers in a traditiona...

APT Blanket Detailed Bin Model Based on Initial Plate-Type Design -3D FLOWTRAN-TF Model

International Nuclear Information System (INIS)

Hamm, L.L.

1998-01-01

This report provides background information for a series of reports documenting accident scenario simulations for the Accelerator Production of Tritium (APT) blanket heat removal systems. The simulations were performed in support of the Preliminary Safety Analysis Report for the APT. This report gives a brief description of the FLOWTRAN-TF code which was used for detailed blanket bin modeling

Study of surface functionalization on IDE by using 3-aminopropyl triethoxysilane (APTES) for cervical cancer detection

Science.gov (United States)

Raqeema, S.; Hashim, U.; Azizah, N.

2016-07-01

This paper presented the study of surface functionalization on IDE by using 3-Aminopropyl triethoxysilane (APTES). The DNA nanochip based interdigitated (IDE) has been proposed to optimized the sensitivity of the device due to the cervical cancer detection. The DNA nanochip will be more efficient using surface modification of TiO2 nanoparticles with 3-Aminopropyl triethoxysilane (APTES). Furthermore, APTES gain the better functionalization of the adsorption mechanism on IDE. The combination of the DNA probe and the HPV target will produce more sensitivity and speed of the DNA nanochip due to their properties. The IDE has been characterized using current-voltage (IV) measurement. This functionalization of the surface would be applicable, sensitive, selective and low cost for cervical cancer detection.

RAMI modeling of selected balance of plant systems for the proposed Accelerator Production of Tritium (APT) project

International Nuclear Information System (INIS)

Radder, J.A.; Cramer, D.S.

1997-01-01

In order to meet Department of Energy (DOE) Defense Program requirements for tritium in the 2005-2007 time frame, new production capability must be made available. The Accelerator Production of Tritium (APT) Plant is being considered as an alternative to nuclear reactor production of tritium, which has been the preferred method in the past. The proposed APT plant will use a high-power proton accelerator to generate thermal neutrons that will be captured in 3 He to produce tritium (3H). It is expected that the APT Plant will be built and operated at the DOE's Savannah River Site (SRS) in Aiken, South Carolina. Discussion is focused on Reliability, Availability, Maintainability, and Inspectability (RAMI) modeling of recent conceptual designs for balance of plant (BOP) systems in the proposed APT Plant. In the conceptual designs for balance of plant (BOP) systems in the proposed APT Plant. In the conceptual design phase, system RAMI estimates are necessary to identify the best possible system alternative and to provide a valid picture of the cost effectiveness of the proposed system for comparison with other system alternatives. RAMI estimates in the phase must necessarily be based on generic data. The objective of the RAMI analyses at the conceptual design stage is to assist the designers in achieving an optimum design which balances the reliability and maintainability requirements among the subsystems and components

Synthesis, characterization and catalytic activity of CoFe{sub 2}O{sub 4}-APTES-Pd magnetic recyclable catalyst

Energy Technology Data Exchange (ETDEWEB)

Demirelli, M. [Department of Chemistry, Faculty of Arts and Sciences, Yıldız Teknik University Davutpaşa Campus, Esenler, İstanbul (Turkey); Department of Chemistry, Faculty of Arts and Sciences, Fatih University, B. Cekmece, İstanbul 34500 (Turkey); Karaoğlu, E., E-mail: ebubekirkaraoglu@gmail.com [Department of Chemistry, Faculty of Arts and Sciences, Fatih University, B. Cekmece, İstanbul 34500 (Turkey); Department of Medical Biochemistry, Faculty of Medicine, Sakarya University, Korucuk, Sakarya (Turkey); Baykal, A. [Department of Chemistry, Faculty of Arts and Sciences, Fatih University, B. Cekmece, İstanbul 34500 (Turkey); Sözeri, H.; Uysal, E. [TUBITAK-UME, National Metrology Institute, PO Box 54, 41470 Gebze, Kocaeli (Turkey)

2014-01-05

Highlights: • CoFe{sub 2}O{sub 4}-APTES-Pd (0) nanocomposite, as effective catalysts for reduction reactions. • It could be reused several times without significant loss in hydrogenation reaction. • So far, CoFe{sub 2}O{sub 4}-APTES-Pd (0) nanocomposite have not been synthesized. • CoFe{sub 2}O{sub 4}-APTES-Pd (0) nanocomposite was confirmed by XRD, FT-IR. • Pd containing nanoparticles embedded in organic surfactant observed by TEM. -- Abstract: A new magnetically recyclable catalyst, CoFe{sub 2}O{sub 4}-APTES-Pd(0) nanocomposite, as highly effective catalysts for reduction reactions in liquid phase was fabricated and characterized. The reduction of Pd{sup 2+} was accomplished with sodium borohydride (NaBH{sub 4}). The chemical characterization of the product was done with X-ray diffractometry, infrared spectroscopy, transmission electron microscopy, UV–Vis spectroscopy and inductively coupled plasma. It was found that the combination of CoFe{sub 2}O{sub 4} and 3-aminopropyltriethoxysilane (APTES) could give rise to structurally stable catalytic sites. Furthermore, the high magnetization CoFe{sub 2}O{sub 4}-APTES-Pd(0) catalyst can be recovered by magnet and reused for ten runs for hydrogenation reaction of 4-nitro aniline, 1,3 dinitro and cyclohexanone. The catalyst was easily isolated from the reaction mixture by a magnetic bar and reused at least 10 times without significant degradation in the activity which shows the indicative of a potential applications of these catalysts in industry.

Simulation of dynamic traffic loading based on accelerated pavement testing (APT)

CSIR Research Space (South Africa)

Steyn, WJvdM

2004-03-01

Full Text Available The objective of this paper is to introduce the latest Heavy Vehicle Simulator (HVS) technology as part of the South African Accelerated Pavement Testing (APT) efforts, its capabilities and expected impact on road pavement analysis....

Amide Proton Transfer (APT) MR imaging and Magnetization Transfer (MT) MR imaging of pediatric brain development

International Nuclear Information System (INIS)

Zhang, Hong; Kang, Huiying; Peng, Yun; Zhao, Xuna; Jiang, Shanshan; Zhang, Yi; Zhou, Jinyuan

2016-01-01

To quantify the brain maturation process during childhood using combined amide proton transfer (APT) and conventional magnetization transfer (MT) imaging at 3 Tesla. Eighty-two neurodevelopmentally normal children (44 males and 38 females; age range, 2-190 months) were imaged using an APT/MT imaging protocol with multiple saturation frequency offsets. The APT-weighted (APTW) and MT ratio (MTR) signals were quantitatively analyzed in multiple brain areas. Age-related changes in MTR and APTW were evaluated with a non-linear regression analysis. The APTW signals followed a decreasing exponential curve with age in all brain regions measured (R"2 = 0.7-0.8 for the corpus callosum, frontal and occipital white matter, and centrum semiovale). The most significant changes appeared within the first year. At maturation, larger decreases in APTW and lower APTW values were found in the white matter. On the contrary, the MTR signals followed an increasing exponential curve with age in the same brain regions measured, with the most significant changes appearing within the initial 2 years. There was an inverse correlation between the MTR and APTW signal intensities during brain maturation. Together with MT imaging, protein-based APT imaging can provide additional information in assessing brain myelination in the paediatric population. (orig.)

Amide Proton Transfer (APT) MR imaging and Magnetization Transfer (MT) MR imaging of pediatric brain development

Energy Technology Data Exchange (ETDEWEB)

Zhang, Hong; Kang, Huiying; Peng, Yun [Beijing Children' s Hospital, Capital Medical University, Imaging Center, Department of Radiology, Beijing (China); Zhao, Xuna [Philips Healthcare, Beijing (China); Jiang, Shanshan; Zhang, Yi; Zhou, Jinyuan [Johns Hopkins University, Division of MR Research, Department of Radiology, Baltimore, MD (United States)

2016-10-15

To quantify the brain maturation process during childhood using combined amide proton transfer (APT) and conventional magnetization transfer (MT) imaging at 3 Tesla. Eighty-two neurodevelopmentally normal children (44 males and 38 females; age range, 2-190 months) were imaged using an APT/MT imaging protocol with multiple saturation frequency offsets. The APT-weighted (APTW) and MT ratio (MTR) signals were quantitatively analyzed in multiple brain areas. Age-related changes in MTR and APTW were evaluated with a non-linear regression analysis. The APTW signals followed a decreasing exponential curve with age in all brain regions measured (R{sup 2} = 0.7-0.8 for the corpus callosum, frontal and occipital white matter, and centrum semiovale). The most significant changes appeared within the first year. At maturation, larger decreases in APTW and lower APTW values were found in the white matter. On the contrary, the MTR signals followed an increasing exponential curve with age in the same brain regions measured, with the most significant changes appearing within the initial 2 years. There was an inverse correlation between the MTR and APTW signal intensities during brain maturation. Together with MT imaging, protein-based APT imaging can provide additional information in assessing brain myelination in the paediatric population. (orig.)

First records of sponge-associated Actinomycetes from two coastal ...

African Journals Online (AJOL)

First records of sponge-associated Actinomycetes from two coastal sponges from Mauritius. Sandeep Shivram Beepat, Chandani Appadoo, Daniel Edgard Pierre Marie, Shamimtaz Bibi Sadally, Jose Pavao Mendes Paula, Kannan Sivakumar, Rashmi Ragothama Rao, Maryam Salah ...

APT cost scaling: Preliminary indications from a Parametric Costing Model (PCM)

International Nuclear Information System (INIS)

Krakowski, R.A.

1995-01-01

A Parametric Costing Model has been created and evaluate as a first step in quantitatively understanding important design options for the Accelerator Production of Tritium (APT) concept. This model couples key economic and technical elements of APT in a two-parameter search of beam energy and beam power that minimizes costs within a range of operating constraints. The costing and engineering depth of the Parametric Costing Model is minimal at the present open-quotes entry levelclose quotes, and is intended only to demonstrate a potential for a more-detailed, cost-based integrating design tool. After describing the present basis of the Parametric Costing Model and giving an example of a single parametric scaling run derived therefrom, the impacts of choices related to resistive versus superconducting accelerator structures and cost of electricity versus plant availability (open-quotes load curveclose quotes) are reported. Areas of further development and application are suggested

The Analysis of Income per Capita Convergence on ASEAN Plus Three (APT Countries

Directory of Open Access Journals (Sweden)

Any Fatiwetunusa

2017-09-01

Full Text Available The main objective of this study is to test the convergence of income per capita in APT countries through three models: absolute convergence, conditional convergence and sigma convergence. Regression analysis of panel data from 13 APT countries during the period of 2001-2014 is used to analysed to study problem. In absolute convergence model, the growth of real GDP per capita and initial real GDP are used as the variables, meanwhile, 8 variables such as the growth of real GPD per capita, initial real GDP per capita, labor force ratio, value added in agricultural sector, value added in industrial sector, terms of trade, foreign direct investment and internet users ratio are analyzed in conditional convergence model. According to the Solow model, the economies of the countries will converge in which the growth of income per capita of developing countries will be higher than those of developed countries. The economies will be convergent if the countries tend to move to a similar steady state resulting in smaller gap between the countries. Based on the results of absolute convergence and conditional convergence models, APT countries is converging with the rate of 2% and 2.2%. This is consistent with the results of sigma convergence model that shows a declining trend in the dispersion of real GDP per capita in APT regions. The growth of real GDP per capita is influenced by initial GDP per capita, labor force ratio, value added in agricultural sector, value added in industrial sector, terms of trade, foreign direct investment and internet users ratio. Developed countries such as Singapore, Brunei Darussalam and South Korea experience the impact of high real GDP per capita growth. On the contrary, Indonesia, Laos, Vietnam and The Phillipines undergo the impact of low GDP per capita growth.

Kinetics of (3-aminopropyl)triethoxylsilane (APTES) silanization of superparamagnetic iron oxide nanoparticles.

Science.gov (United States)

Liu, Yue; Li, Yueming; Li, Xue-Mei; He, Tao

2013-12-10

Silanization of magnetic ironoxide nanoparticles with (3-aminopropyl)triethoxylsilane (APTES) is reported. The kinetics of silanization toward saturation was investigated using different solvents including water, water/ethanol (1/1), and toluene/methanol (1/1) at different reaction temperature with different APTES loading. The nanoparticles were characterized by Fourier transform infrared spectroscopy, vibrating sample magnetometry, transmission electron microscopy, and thermal gravimetric analysis (TGA). Grafting density data based on TGA were used for the kinetic modeling. It is shown that initial silanization takes place very fast but the progress toward saturation is very slow, and the mechanism may involve adsorption, chemical sorption, and chemical diffusion processes. The highest equilibrium grafting density of 301 mg/g was yielded when using toluene/methanol mixture as the solvent at a reaction temperature of 70 °C.

A functional screen implicates microRNA-138-dependent regulation of the depalmitoylation enzyme APT1 in dendritic spine morphogenesis

DEFF Research Database (Denmark)

Siegel, Gabriele; Obernosterer, Gregor; Fiore, Roberto

2009-01-01

of acyl protein thioesterase 1 (APT1), an enzyme regulating the palmitoylation status of proteins that are known to function at the synapse, including the alpha(13) subunits of G proteins (Galpha(13)). RNA-interference-mediated knockdown of APT1 and the expression of membrane-localized Galpha(13) both...... suppress spine enlargement caused by inhibition of miR-138, suggesting that APT1-regulated depalmitoylation of Galpha(13) might be an important downstream event of miR-138 function. Our results uncover a previously unknown miRNA-dependent mechanism in neurons and demonstrate a previously unrecognized...

Corrosion measurements on apt prototypic materials in the Lansce high-power proton beam and applicability to other systems

International Nuclear Information System (INIS)

Lillard, R.S.; Gac, F.D.; James, M.R.; Maloy, S.A.; Paciotti, M.A.; Waters, L.S.; Willcutt, G.J.; Chandler, G.T.; Ferguson, P.D.

2003-01-01

The corrosion rates of several corrosion resistant materials behave in a similar manner even under the intense radiation of the LANSCE high-power beam. A second observation was made, showing that the corrosion rates saturated under high instantaneous radiation intensity in corrosion experiments conducted for the accelerator production of tritium (APT) programme. The LANSCE H + beam is not prototypic of the proposed APT production plant in several respects. The instantaneous proton flux in the APT production plant beam is about 10 times that of the LANSCE beam. The small transverse APT beam spot is rastered to spread the power density over the area of the target, and as the beam rasters, it creates a pulsed character to the beam at a specific location. In order to develop correlations that would enable extrapolation of the corrosion data to the proposed APT production plant, the experimental programme included measurements over a range of average beam currents, measurements at high and low instantaneous beam current, and measurements at various combinations of pulse width and repetition rate. The correlations that were developed are based on an approximately linear dependence of corrosion rate on average beam current (average radiation intensity) and the saturation effect observed at high instantaneous radiation intensity. For a given transverse beam profile and for the same average beam current, the correlations predict the highest corrosion rate in a do beam and the lowest corrosion rate in the lowest duty cycle beams. In the case of the APT extrapolation, the predicted corrosion rates were a factor of 5 lower than for a do beam depositing the same average power density. The measured corrosion rates and the formulated extrapolations are applicable to water-cooled targets and components in proton beams. (authors)

Scientific and engineering services for the LANCE/ER accelerator production of tritium (APT) project

International Nuclear Information System (INIS)

1994-01-01

The APT project office is conducting a preconceptual design study for an accelerator driven concept to produce tritium. The facility will require new technology in many areas, since the scale of this accelerator is significantly larger then any in operation to date. The facility is composed of four subsystems: accelerator, target ampersand blanket, balance of plant, and tritium purification system (TPS). New physics realms will be entered in order for the concept to be feasible; for example, extremely high energy levels of the entering protons that induce (multiplicative) spallation of the neutrons from the high Z target will occur. These are complex and require advance codes (MCNP) to predict the physics interactions and as well as deleterious material effects in the surrounding structures. Other issues include component cooling and complex thermal-hydraulics effects within the blanket and the beam open-quotes window.close quotes In order to support a DOE mandated fast ROD schedule, Los Alamos APT staff will be provided with senior, engineering technical support staff with direct APT technology experience and whom are open-quotes on siteclose quotes. This report contains resumes of the staff

Amide proton transfer (APT) imaging of brain tumors at 7 T : The role of tissue water T1 -Relaxation properties

NARCIS (Netherlands)

Khlebnikov, V; Polders, Daniel; Hendrikse, J; Robe, Pierre A.; Voormolen, Eduard H; Luijten, Peter R; Klomp, DWJ; Hoogduin, Hans

PURPOSE: To provide insight into the effect of water T1 relaxation (T1wat ) on amide proton transfer (APT) contrast in tumors. Three different metrics of APT contrast-magnetization transfer ratio (MTRRex ), relaxation-compensated MTRRex (AREX), and traditional asymmetry (MTRasym )-were compared in

Conceptual Design of an APT Reusable Spaceplane

Science.gov (United States)

Corpino, S.; Viola, N.

This paper concerns the conceptual design of an Aerial Propellant Transfer reusable spaceplane carried out during our PhD course under the supervision of prof. Chiesa. The new conceptual design methodology employed in order to develop the APT concept and the main characteristics of the spaceplane itself will be presented and discussed. The methodology for conceptual design has been worked out during the last three years. It was originally thought for atmospheric vehicle design but, thanks to its modular structure which makes it very flexible, it has been possible to convert it to space transportation systems design by adding and/or modifying a few modules. One of the major improvements has been for example the conception and development of the mission simulation and trajectory optimisation module. The methodology includes as main characteristics and innovations the latest techniques of geometric modelling and logistic, operational and cost aspects since the first stages of the project. Computer aided design techniques are used to obtain a better definition of the product at the end of the conceptual design phase and virtual reality concepts are employed to visualise three-dimensional installation and operational aspects, at least in part replacing full-scale mock- ups. The introduction of parametric three-dimensional CAD software integrated into the conceptual design methodology represents a great improvement because it allows to carry out different layouts and to assess them immediately. It is also possible to link the CAD system to a digital prototyping software which combines 3D visualisation and assembly analysis, useful to define the so-called Digital Mock-Up at Conceptual Level (DMUCL) which studies the integration between the on board systems, sized with simulation algorithms, and the airframe. DMUCL represents a very good means to integrate the conceptual design with a methodology turned towards dealing with Reliability, Availability, Maintainability and

Anti-prothrombin (aPT) and anti-phosphatidylserine/prothrombin (aPS/PT) antibodies and the risk of thrombosis in the antiphospholipid syndrome. A systematic review.

Science.gov (United States)

Sciascia, Savino; Sanna, Giovanni; Murru, Veronica; Roccatello, Dario; Khamashta, Munther A; Bertolaccini, Maria Laura

2014-02-01

Antibodies to prothrombin are detected by directly coating prothrombin on irradiated ELISA plates (aPT) or by using the phosphatidylserine/prothrombin complex as antigen (aPS/PT). Although these antibodies have both been associated with antiphospholipid syndrome (APS) and a correlation between the two assays have been reported, it seems that aPT and aPS/PT belong to different populations of autoantibodies. It was our objective to systematically review the available evidence on aPT and aPS/PT antibodies and the risk of thrombosis in APS. Medline-reports published between 1988 and 2013 investigating aPT and aPS/PT as a risk factor for thrombosis were included. Whenever possible, antibody isotype(s) and site of thrombosis were analysed. This systematic review is based on available data from more than 7,000 patients and controls from 38 studies analysing aPT and 10 aPS/PT. Antibodies to prothrombin (both aPT and aPS/PT) increased the risk of thrombosis (odds ratio [OR] 2.3; 95% confidence interval [CI] 1.72-3.5). aPS/PT seemed to represent a stronger risk factor for thrombosis, both arterial and/or venous than aPT (OR 5.11; 95%CI 4.2-6.3 and OR 1.82; 95%CI 1.44-2.75, respectively). In conclusion, routine measurement of aPS/PT (but not aPT) might be useful in establishing the thrombotic risk of patients with previous thrombosis and/or systemic lupus erythematosus. Their inclusion as laboratory criteria for the APS should be indisputably further explored.

Study of different 3-aminopropyl triethoxysilane (APTES) concentration on TiO2 particles based IDE for cervical cancer detection

Science.gov (United States)

Raqeema, S.; Hashim, U.; Azizah, N.; Nadzirah, Sh.; Arshad, M. K. Md; Ruslinda, A. R.; Gopinath, Subash C. B.

2017-03-01

HPV that also called Human Papillomaviruses is the major cause of the cervical cancer. HPV 16 and HPV 18 are the two types of HPV are the most HPV-associated cancers and responsible as a high-risk HPV. Cervical cancer taken about 70 percent of all cases due HPV infections. Cervical malignancy for the most part development on a lady's cervix and its was developed slowly as cancer disease. TiO2 particles give better performance and low cost of the biosensor. The used of 3-aminopropyl triethoxysilane (APTES) will be more efficient for DNA nanochip. APTES used as absorption reaction to immobilize organic biomolecules on the inorganic surface. Besides, APTES give better functionalization of the adsorption mechanism on IDE. The surface functionalized for immobilizing the DNA, which is the combination of the DNA probe and the HPV target produce high sensitivity andfast detection of the IDE. The Current-Voltage (IV) characteristic proved the sensitivity of the DNA nanochip increase as the concentration varied from 0% concentration to 24% of APTES concentration.

Development of a commissioning plan for the APT linac

International Nuclear Information System (INIS)

Funk, L.W.; Crandall, K.R.; Gilpatrick, J.D.; Gray, E.R.; Regan, A.H.; Rohlev, A.; Rybarcyk, L.J.; Wangler, T.P.

1998-01-01

The Accelerator Production of Tritium (APT) facility is based on a linac which incorporates both normal-conducting and superconducting RF technology and accelerates a 100-mA cw proton beam to an energy of 1,030 MeV or higher, depending on the desired production rate. Commissioning plans to achieve full power operation with minimum beam-induced activation of components have been evolving. This paper presents the main issues and the basic approaches that are now being discussed

Is Accelerated Partner Therapy (APT) a cost-effective alternative to routine patient referral partner notification in the UK? Preliminary cost-consequence analysis of an exploratory trial.

Science.gov (United States)

Roberts, Tracy E; Tsourapas, Angelos; Sutcliffe, Lorna; Cassell, Jackie; Estcourt, Claudia

2012-02-01

To undertake a cost-consequence analysis to assess two new models of partner notification (PN), known as Accelerated Partner Therapy (APT Hotline and APT Pharmacy), as compared with routine patient referral PN, for sex partners of people with chlamydia, gonorrhoea and non-gonococcal urethritis. Comparison of costs and outcomes alongside an exploratory trial involving two genitourinary medicine clinics and six community pharmacies. Index patients selected the PN method (APT Hotline, APT Pharmacy or routine PN) for their partners. Clinics and pharmacies recorded cost and resource use data including duration of consultation and uptake of treatment pack. Cost data were collected prospectively for two out of three interventions, and data were synthesised and compared in terms of effectiveness and costs. Routine PN had the lowest average cost per partner treated (approximately £46) compared with either APT Hotline (approximately £54) or APT Pharmacy (approximately £53) strategies. The cost-consequence analysis revealed that APT strategies were more costly but also more effective at treating partners compared to routine PN. The hotline strategy costs more than both the alternative PN strategies. If we accept that strategies which identify and treat partners the fastest are likely to be the most effective in reducing reinfection and onward transmission, then APT Hotline appears an effective PN strategy by treating the highest number of partners in the shortest duration. Whether the additional benefit is worth the additional cost cannot be determined in this preliminary analysis. These data will be useful for informing development of future randomised controlled trials of APT.

Can we improve partner notification rates through expedited partner therapy in the UK? Findings from an exploratory trial of Accelerated Partner Therapy (APT).

Science.gov (United States)

Estcourt, Claudia; Sutcliffe, Lorna; Cassell, Jackie; Mercer, Catherine H; Copas, Andrew; James, Laura; Low, Nicola; Horner, Patrick; Clarke, Michael; Symonds, Merle; Roberts, Tracy; Tsourapas, Angelos; Johnson, Anne M

2012-02-01

To develop two new models of expedited partner therapy for the UK, and evaluate them for feasibility, acceptability and preliminary outcome estimates to inform the design of a randomised controlled trial (RCT). Two models of expedited partner therapy (APTHotline and APTPharmacy), known as 'Accelerated Partner Therapy' (APT) were developed. A non-randomised comparative study was conducted of the two APT models and routine partner notification (PN), in which the index patient chose the PN option for his/her partner(s) in two contrasting clinics. The proportion of contactable partners treated when routine PN was chosen was 42/117 (36%) and was significantly higher if either APT option was chosen: APTHotline 80/135 (59%), p=0.003; APTPharmacy 29/44 (66%) p=0.001. However, partner treatment was often achieved through other routes. Although 40-60% of partners in APT groups returned urine samples for sexually transmitted infection (STI) testing, almost none accessed HIV and syphilis testing. APT options appear to facilitate faster treatment of sex partners than routine PN. Preferences and recruitment rates varied between sites, related to staff satisfaction with existing routine PN; approach to consent; and possibly, characteristics of local populations. Both methods of APT were feasible and acceptable to many patients and led to higher rates of partner treatment than routine PN. Preferences and recruitment rates varied greatly between settings, suggesting that organisational and cultural factors may have an important impact on the feasibility of an RCT and on outcomes. Mindful of these factors, it is proposed that APT should now be evaluated in a cluster RCT.

APTES Functionalized Iron Oxide-Silver Magnetic Hetero-Nanocomposites for Selective Capture and Rapid Removal of Salmonella enteritidis from Aqueous Solution

Science.gov (United States)

Trang, Vu Thi; Dinh, Ngo Xuan; Lan, Hoang; Tam, Le Thi; Huy, Tran Quang; Tuan, Pham Anh; Phan, Vu Ngoc; Le, Anh-Tuan

2018-02-01

Magnetic nanomaterials, as a promising platform for the fast and sensitive detection of bacterial pathogens, have attracted increasing interest from researchers in recent years. In this work, by utilizing a two-step synthetic technique consisting of co-precipitation and subsequent hydrothermal reaction, followed by functionalization steps with (3-aminopropyl)triethoxysilane (APTES) and the antibody against Salmonella enteritidis, antibody-conjugated Fe3O4-Ag@APTES hetero-nanocomposites were successfully prepared. Due to the specific antibody, the developed Fe3O4-Ag@APTES@SE-Ab conjugates are capable of selectively capturing S. enteritidis at a low concentration of about 101 CFU/mL. Moreover, the prepared magnetic conjugates also revealed that the S. enteritidis could be rapidly removed from water solution in 20 min by using an external magnetic field with a removal efficiency obtained of ˜ 91.36%. These results indicated that the Fe3O4-Ag@APTES@SE-Ab conjugates are promising for the rapid selective capture and removal of bacterial pathogens from aqueous environments, and can be used for improving the detection quality of pathogens in water samples using immunosensor-based diagnostic tests.

Development of a RAMI model for LANSCE and high power APT accelerators

International Nuclear Information System (INIS)

Tallerico, P.J.

1994-01-01

Assessment of the reliability, availability, maintainability and inspectability (RAMI) of all high power, high cost systems is important to justify and improve the cost effectiveness of these systems. For the very large (over 100 MW) accelerator systems associated with APT, a RAMI model is very valuable in guiding the design and allocation of resources. A RAMI model of an existing machine is also valuable, since machine improvement funds must be allocated to increase the availability by the largest amount. The authors have developed a RAMI model using the critical subsystems of the LANSCE accelerator and beam delivery complex as an example and to evaluate the effectiveness for estimating reliability and beam availability. LAMPF and LANSCE together provide most of the features required for the accelerator and beam delivery part of a high-power APT machine, but LANSCE is pulsed, rather than CW. This complex is capable of a 1-MW average power H - beam, and it is the most powerful proton accelerator in the US built to date

APT analyses of deuterium-loaded Fe/V multi-layered films

KAUST Repository

Gemma, R.

2009-04-01

Interaction of hydrogen with metallic multi-layered thin films remains as a hot topic in recent days Detailed knowledge on such chemically modulated systems is required if they are desired for application in hydrogen energy system as storage media. In this study, the deuterium concentration profile of Fe/V multi-layer was investigated by atom probe tomography (APT) at 60 and 30 K. It is firstly shown that deuterium-loaded sample can easily react with oxygen at the Pd capping layer on Fe/V and therefore, it is highly desired to avoid any oxygen exposure after D(2) loading before APT analysis. The analysis temperature also has an impact on D concentration profile. The result taken at 60 K shows clear traces of surface segregation of D atoms towards analysis surface. The observed diffusion profile of D allows us to estimate an apparent diffusion coefficient D. The calculated D at 60 K is in the order of 10(-17) cm(2)/s, deviating 6 orders of magnitude from an extrapolated value. This was interpreted with alloying, D-trapping at defects and effects of the large extension to which the extrapolation was done. A D concentration profile taken at 30 K shows nosegregation anymore and a homogeneous distribution at C(D) = 0.05(2) D/Me, which is in good accordance with that measured in the corresponding pressure-composition isotherm. (C) 2008 Elsevier B.V. All rights reserved.

APT analyses of deuterium-loaded Fe/V multi-layered films

KAUST Repository

Gemma, R.; Al-Kassab, Talaat; Kirchheim, R.; Pundt, A.

2009-01-01

Interaction of hydrogen with metallic multi-layered thin films remains as a hot topic in recent days Detailed knowledge on such chemically modulated systems is required if they are desired for application in hydrogen energy system as storage media. In this study, the deuterium concentration profile of Fe/V multi-layer was investigated by atom probe tomography (APT) at 60 and 30 K. It is firstly shown that deuterium-loaded sample can easily react with oxygen at the Pd capping layer on Fe/V and therefore, it is highly desired to avoid any oxygen exposure after D(2) loading before APT analysis. The analysis temperature also has an impact on D concentration profile. The result taken at 60 K shows clear traces of surface segregation of D atoms towards analysis surface. The observed diffusion profile of D allows us to estimate an apparent diffusion coefficient D. The calculated D at 60 K is in the order of 10(-17) cm(2)/s, deviating 6 orders of magnitude from an extrapolated value. This was interpreted with alloying, D-trapping at defects and effects of the large extension to which the extrapolation was done. A D concentration profile taken at 30 K shows nosegregation anymore and a homogeneous distribution at C(D) = 0.05(2) D/Me, which is in good accordance with that measured in the corresponding pressure-composition isotherm. (C) 2008 Elsevier B.V. All rights reserved.

Prevalence of antibodies to prothrombin in solid phase (aPT) and to phosphatidylserine-prothrombin complex (aPS/PT) in patients with and without lupus anticoagulant.

Science.gov (United States)

Bertolaccini, Maria Laura; Sciascia, Savino; Murru, Veronica; Garcia-Fernandez, Cesar; Sanna, Giovanni; Khamashta, Munther A

2013-02-01

Antibodies to prothrombin in solid phase (aPT) and those to phosphatidiyserine-prothrombin complex (aPS/PT) have been suggested to strongly correlate with the presence of lupus anticoagulant (LA). As their clinical diagnostic value and true relationship with the LA remains elusive, we designed this study to evaluate the prevalence and significance of aPT and aPS/PT in a large cohort of patients with and without LA. Samples from 257 patients were included. aPT and aPS/PT were tested by ELISA. LA was tested as per the current criteria from the ISTH Subcommittee on LA-Phospholipid-dependent antibodies. aPS/PT and aPT were found in 51% and 32% of LA-positive (LA+ve) patients and in 22% and 28% of LA-negative (LA-ve) patients, respectively. Thrombosis, particularly venous thrombosis was associated with IgG aPT in the LA+ve group (p=0.0006) and in the LA-ve group (p=0.017). Antibodies to phosphatidylserine-prothrombin, either IgG and IgM were associated with thrombosis in general (p=0.0003) in particularly with venous thrombosis in the LA+ve group (paPS/PT were independent risk factors for thrombosis and pregnancy loss. In conclusion, aPS/PT, but not aPT, are more frequently found in patients with LA. Their association with thrombosis seems to be independent of the presence of LA.

New tests to detect antiphospholipid antibodies: antiprothrombin (aPT) and anti-phosphatidylserine/prothrombin (aPS/PT) antibodies.

Science.gov (United States)

Sciascia, Savino; Khamashta, Munther A; Bertolaccini, Maria Laura

2014-05-01

Antiprothrombin antibodies have been proposed as potential new biomarkers for thrombosis and/or pregnancy morbidity in the setting of the antiphospholipid syndrome (APS). Antiprothrombin antibodies are commonly detected by ELISA, using prothrombin coated onto irradiated plates (aPT), or prothrombin in complex with phosphatidylserine (aPS/PT), as antigen. Although these antibodies can co-exist in the same patient, aPT and aPS/PT seem to belong to different populations of autoantibodies. Early research explored the role of antibodies to prothrombin as potential antigenic targets for the lupus anticoagulant (LA). To date their clinical significance is being investigated and their potential role in identifying patients at higher risk of developing thrombotic events or pregnancy morbidity is being probed.

Micah 1, an apt introduction to power talks

Directory of Open Access Journals (Sweden)

W.J. Wessels

1998-08-01

Full Text Available Power and the abuse of it, is often an integral part of discussions in any society. The prophets of the Old Testament felt strongly about this issue and often spoke out against the abuse of power and the suffering caused by it. Micah particularly addresses this issue in chapters 2 and 3. He blames the leaders in society, who should look out for the ordinary people, that they in particular are guilty of this transgression. In chapter 1 Micah proclaims Yahweh as the sovereign power who they should take note off. On the very basis of Yahweh's sovereign power he then proclaims oracles of judgment on the people of Judah. Micah 1 seems to form an apt introduction to the talks of the abuse of power in the society of Judah.

CNET and APT : a comparison of two methods for measuring mental representations underlying activity-travel choices

NARCIS (Netherlands)

Horeni, O.; Arentze, T.A.; Dellaert, B.G.C.; Timmermans, H.J.P.

2010-01-01

This paper presents and compares the potential of online versions of two interview techniques (APT and CNET) which have been developed for measuring mental representations underlying activity-travel choices. The comparison is based on the results of a first online survey administered in the

Adsorption of Pb(II) using silica gel composite from rice husk ash modified 3-aminopropyltriethoxysilane (APTES)-activated carbon from coconut shell

Science.gov (United States)

Yusmaniar, Purwanto, Agung; Putri, Elfriyana Awalita; Rosyidah, Dzakiyyatur

2017-03-01

Silica gel modified by 3-aminopropyltriethoxysilane (APTES) was synthesized from rice husk ash combined with activated carbon from coconut shell yielded the composite adsorbent. The composite was characterized by Fourier Transform Infra Red spectroscopy (FT-IR), Electron Dispersive X-Ray (EDX), Surface Area Analyzer (SAA) and adsorption test by Atomic Absorption Spectrometry (AAS). This composite adsorbent has been used moderately for the removal of lead ions from metal solutions and compared with silica gel modified APTES and activated carbon. The adsorption experiments of Pb -ions by adsorbents were performed at different pH and contact time with the same metal solutions concentration, volume solution, and adsorbent dosage. The optimum pH for the adsorption was found to be 5.0 and the equilibrium was achieved for Pb with 20 min of contact time. Pb ions adsorption by composite silica gel modified APTES-activated carbon followed by Langmuir isotherm model with qmax value of 46.9483 mg/g that proved an adsorbent mechanism consistent to the mechanism of monolayer formation.

Radiation protection system installation for the accelerator production of tritium/low energy demonstration accelerator project (APT/LEDA)

CERN Document Server

Wilmarth, J E; Tomei, T L

2000-01-01

The APT/LEDA personnel radiation protection system installation was accomplished using a flexible, modular proven system which satisfied regulatory orders, project design criteria, operational modes, and facility requirements. The goal of providing exclusion and safe access of personnel to areas where prompt radiation in the LEDA facility is produced was achieved with the installation of a DOE-approved Personnel Access Control System (PACS). To satisfy the facility configuration design, the PACS, a major component of the overall radiation safety system, conveniently provided five independent areas of personnel access control. Because of its flexibility and adaptability the Los-Alamos Neutron- Science-Center-(LANSCE)-designed Radiation Security System (RSS) was efficiently configured to provide the desired operational modes and satisfy the APT/LEDA project design criteria. The Backbone Beam Enable (BBE) system based on the LANSCE RSS provided the accelerator beam control functions with redundant, hardwired, ta...

High density gold nanoparticles immobilized on surface via plasma deposited APTES film for decomposing organic compounds in microchannels

Science.gov (United States)

Rao, Xi; Guyon, Cédric; Ognier, Stephanie; Da Silva, Bradley; Chu, Chenglin; Tatoulian, Michaël; Hassan, Ali Abou

2018-05-01

Immobilization of colloidal particles (e.g. gold nanoparticles (AuNps)) on the inner surface of micro-/nano- channels has received a great interest for catalysis. A novel catalytic ozonation setup using a gold-immobilized microchannel reactor was developed in this work. To anchor AuNps, (3-aminopropyl) triethoxysilane (APTES) with functional amine groups was deposited using plasma enhanced chemical vapor deposition (PECVD) process. The results clearly evidenced that PECVD processing exhibited relatively high efficiency for grafting amine groups and further immobilizing AuNPs. The catalytic activity of gold immobilized microchannel was evaluated by pyruvic acid ozonation. The decomposition rate calculated from High Performance Liquid Chromatography (HPLC) indicated a much better catalytic performance of gold in microchannel than that in batch. The results confirmed immobilizing gold nanoparticles on plasma deposited APTES for preparing catalytic microreactors is promising for the wastewater treatment in the future.

APT LLRF control system functionality and architecture

International Nuclear Information System (INIS)

Regan, A.H.; Rohlev, A.S.; Ziomek, C.D.

1996-01-01

The low-level RF (LLRF) control system for the Accelerator Production of Tritium (APT) will perform various functions. Foremost is the feedback control of the accelerating fields within the cavity in order to maintain field stability within ± 1% amplitude and 1 degree phase. The feedback control system requires a phase-stable RF reference subsystem signal to correctly phase each cavity. Also, instead of a single klystron RF source for individual accelerating cavities, multiple klystrons will drive a string of resonantly coupled cavities, based on input from a single LLRF feedback control system. To achieve maximum source efficiency, we will be employing single fast feedback controls around individual klystrons such that the gain and phase characteristics of each will be 'identical'. In addition, the resonance condition of the cavities is monitored and maintained. To quickly respond to RF shutdowns, and hence rapid accelerating cavity cool-down, due to RF fault conditions, drive frequency agility in the main feedback control subsystem will also be incorporated. Top level block diagrams will be presented and described as they will first be developed and demonstrated on the Low Energy Demonstrator Accelerator (LEDA). (author)

AptRank: an adaptive PageRank model for protein function prediction on   bi-relational graphs.

Science.gov (United States)

Jiang, Biaobin; Kloster, Kyle; Gleich, David F; Gribskov, Michael

2017-06-15

Diffusion-based network models are widely used for protein function prediction using protein network data and have been shown to outperform neighborhood-based and module-based methods. Recent studies have shown that integrating the hierarchical structure of the Gene Ontology (GO) data dramatically improves prediction accuracy. However, previous methods usually either used the GO hierarchy to refine the prediction results of multiple classifiers, or flattened the hierarchy into a function-function similarity kernel. No study has taken the GO hierarchy into account together with the protein network as a two-layer network model. We first construct a Bi-relational graph (Birg) model comprised of both protein-protein association and function-function hierarchical networks. We then propose two diffusion-based methods, BirgRank and AptRank, both of which use PageRank to diffuse information on this two-layer graph model. BirgRank is a direct application of traditional PageRank with fixed decay parameters. In contrast, AptRank utilizes an adaptive diffusion mechanism to improve the performance of BirgRank. We evaluate the ability of both methods to predict protein function on yeast, fly and human protein datasets, and compare with four previous methods: GeneMANIA, TMC, ProteinRank and clusDCA. We design four different validation strategies: missing function prediction, de novo function prediction, guided function prediction and newly discovered function prediction to comprehensively evaluate predictability of all six methods. We find that both BirgRank and AptRank outperform the previous methods, especially in missing function prediction when using only 10% of the data for training. The MATLAB code is available at https://github.rcac.purdue.edu/mgribsko/aptrank . gribskov@purdue.edu. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

Design of 250-MW CW RF system for APT

International Nuclear Information System (INIS)

Rees, D.

1997-01-01

The design for the RF systems for the APT (Accelerator Production of Tritium) proton linac will be presented. The linac produces a continuous beam power of 130 MW at 1300 MeV with the installed capability to produce up to a 170 MW beam at 1700 MeV. The linac is comprised of a 350 MHz RFQ to 7 MeV followed in sequence by a 700 MHz coupled-cavity drift tube linac, coupled-cavity linac, and superconducting (SC) linac to 1700 MeV. At the 1700 MeV, 100 mA level the linac requires 213 MW of continuous-wave (CW) RF power. This power will be supplied by klystrons with a nominal output power of 1.0 MW. 237 kystrons are required with all but three of these klystrons operating at 700 MHz. The klystron count includes redundancy provisions that will be described which allow the RF systems to meet an operational availability in excess of 95 percent. The approach to achieve this redundancy will be presented for both the normal conducting (NC) and SC accelerators. Because of the large amount of CW RF power required for the APT linac, efficiency is very important to minimize operating cost. Operation and the RF system design, including in-progress advanced technology developments which improve efficiency, will be discussed. RF system performance will also be predicted. Because of the simultaneous pressures to increase RF system reliability, reduce tunnel envelope, and minimize RF system cost, the design of the RF vacuum windows has become an important issue. The power from a klystron will be divided into four equal parts to minimize the stress on the RF vacuum windows. Even with this reduction, the RF power level at the window is at the upper boundary of the power levels employed at other CW accelerator facilities. The design of a 350 MHz, coaxial vacuum window will be presented as well as test results and high power conditioning profiles. The transmission of 950 kW, CW, power through this window has been demonstrated with only minimal high power conditioning

IN VITRO Cr(VI SPECIATION IN SYNTHETIC SALIVA AFTER RELEASING FROM ORTHODONTIC BRACKETS USING SILICA-APTES SEPARATION AND GF AAS DETERMINATION

Directory of Open Access Journals (Sweden)

Maciel S. Luz

Full Text Available A method for Cr(VI speciation in synthetic saliva after releasing from orthodontic brackets, using silica nanoparticles organofunctionalized with (3-aminopropyltriethoxysilane (APTES for Cr(III/Cr(VI separation and GF AAS determination is proposed. Under the optimized conditions, Cr(VI speciation was performed using 150 mg of silica organofunctionalized with 2.0% (v v-1 of APTES at pH 8. It was observed different sensitivity when calibrations of GF AAS were performed using Cr(III or Cr(VI as standard solutions. Consequently, calibrations using stoichiometric mixtures (Cr(III + Cr(VI were used for total Cr determination and calibration using Cr(VI was used only for the determination of this specie. The reliability of the proposed silica-APTES separation procedure and GF AAS determination was checked by addition of both species in synthetic saliva. Recoveries ranging from 97 to 110% were obtained. The repeatability, based on the relative standard deviation (RSD inter days was less than 6%. A corrosion test was carried out on 20 orthodontic brackets from two different models, after immersion in synthetic saliva (pH=6.0 at 37 °C with agitation (125 rpm for 24 h. It was observed that about 40% of the total chromium released from the analyzed orthodontic brackets was Cr(VI.

APT LLRF control system functionality and architecture

International Nuclear Information System (INIS)

Regan, A.H.; Rohlev, A.S.; Ziomek, C.D.

1996-01-01

1% amplitude and l degree phase. The feedback control system requires a phase-stable RF reference subsystem signal to correctly phase each cavity. Also, instead of a single klystron RF source for individual accelerating cavities, multiple klystrons will drive a string of resonantly coupled cavities, based on input from a single LLRF feedback control system. To achieve maximum source efficiency, we will be employing single fast feedback controls around individual klystrons such that the gain and phase characteristics of each will be ''identical.'' In addition, resonance control is performed by providing a proper drive signal to structure cooling water valves in order to keep the cavity resonant during operation. To quickly respond to RF shutdowns, and hence rapid accelerating cavity cool- down, due to RF fault conditions, drive frequency agility in the main feedback control subsystem will also be incorporated. Top level block diagrams will be presented and described for each of the aforementioned subsystems as they will first be developed and demonstrated on the Low Energy Demonstrator Accelerator (LEDA) The low-level RF (LLRF) control system for the Accelerator Production of Tritium (APT) will perform various functions. Foremost is the feedback control of the accelerating fields within the cavity in order to maintain field stability within

The RF system for the Accelerator Production of Tritium (APT) Low Energy Demonstration Accelerator (LEDA) at Los Alamos

International Nuclear Information System (INIS)

Lynch, M.T.; Rees, D.; Tallerico, P.; Regan, A.

1996-01-01

To develop and demonstrate the crucial front end of the APT accelerator and some of the critical components for APT, Los Alamos is building a CW proton accelerator (LEDA) to provide 100 mA at up to 40 MeV. LEDA will be installed where the SDI-sponsored Ground Test Accelerator was located. The first accelerating structure for LEDA is a 7-MeV RFQ operating at 350 MHz, followed by several stages of a coupled-cavity Drift Tube Linac (CCDTL) operating at 700 MHz. The first stage of LEDA will go to 12 MeV. Higher energies, up to 40 MeV, come later in the program. Three 1.2-MW CW RF systems will be used to power the RFQ. This paper describes the RF systems being assembled for LEDA, including the 350 and 700-MHz klystrons, the High Voltage Power Supplies, transmitters, RF transport, window/coupler assemblies, and controls. Some of the limitations imposed by the schedule and the building itself are addressed

The APT program plan: Providing an assured tritium production capability

International Nuclear Information System (INIS)

Lisowski, P.W.; Anderson, J.L.; Bishop, W.P.; Boggs, B.; Hall, K.

1996-01-01

Tritium is a radioactive hydrogen isotope used in all U.S. nuclear weapons. Because the half-life of tritium is short, 12.3 yr, it must be periodically replenished. To provide a new source, the U.S. Department of Energy (DOE) is sponsoring conceptual design and engineering development and demonstration activities for a plant that will use a high-power proton linear accelerator to produce tritium and will go on-line no later than 2007. The APT project is in the process of completing the conceptual design for a tritium production plant. In addition, there are several important areas under engineering development and demonstration that will ensure an efficient, cost-effective plant design and provide an adequate margin of tritium production. Information provided from this work will be used by the DOE in its 1998 choice of production technology implementation

Advanced buck converter power supply ABCPS for APT

International Nuclear Information System (INIS)

Street, R.; Overett, T.; Bowles, E.

1998-01-01

The United States Department of Energy (DOE) is planning to fabricate an Accelerator for the Production of Tritium (APT) at their Savannah River Site, to provide Tritium for national defense. The 1700 million electron volt (MeV) proton beam accelerator will be powered by radio frequency (RF) klystrons. A direct current (DC) power supply is required for each of the approximately two hundred and fifty 1-megawatt (MW) continuous wave klystrons in the RF power system. The requirements are that the power supply meet output performance specifications, provide fault protection for the klystron, have high efficiency, high reliability, good maintainability, and be readily manufacturable. As the power supplies are one of the largest cost elements in the accelerator, a technology review was made to determine the most economical approach to satisfy the requirements. A switch-mode power supply employing a buck-regulator was identified as being potentially the lowest cost approach. As the switch represents a certain development risk, a small-scale prototype has been constructed for evaluation, and has resulted in the decision to fabricate a full-scale prototype power supply. A description of the hardware will be presented

Beam dynamics design of the 211 MeV APT normal conducting linac

International Nuclear Information System (INIS)

Young, L.M.; Billen, J.H.; Takeda, H.; Wood, R.L.

1998-01-01

This paper describes the normal conducting linac design that is part of the Accelerator for Production of Tritium (APT) project. The new version of PARMILA designed this linac. This linac accepts the beam from the 6.7 MeV radio frequency quadrupole without a separate matching section. At about 10 MeV, it has a smooth transition in the length of period from 8βλ to 9βλ in quadrupole focusing lattice. This adjustment of the period was needed to provide sufficient space for the quadrupole focusing magnets and beam diagnostic equipment. The linac consists of the coupled cavity drift tube linac up to 97 MeV and coupled cavity linac above 97 MeV

Overview of the APT high-energy beam transport and beam expanders

International Nuclear Information System (INIS)

Shafer, R.E.; Blind, B.; Gray, E.R.

1997-01-01

The APT high energy beam transport (HEBT) and beam expanders convey the 1700-MeV, 100-mA cw proton beam from the linac to the tritium target/blanket assembly, or a tuning beam stop. The HEBT includes extensive beam diagnostics, collimators, and beam jitter correction, to monitor and control the 170-MW beam prior to expansion. A zero-degree beamline conveys the beam to the beam stop, and an achromatic bend conveys the beam to the tritium production target. Nonlinear beam expanders make use of higher-order multipole magnets and dithering dipoles to expand the beam to a uniform-density, 16-cm wide by 160-cm high rectangular profile on the tritium-production target. The overall optics design will be reviewed, and beam simulations will be presented

Characteristics of Polysilicon Wire Glucose Sensors with a Surface Modified by Silica Nanoparticles/γ-APTES Nanocomposite

Directory of Open Access Journals (Sweden)

Jheng-Jia Jhuang

2011-03-01

Full Text Available This report investigates the sensing characteristics of polysilicon wire (PSW glucose biosensors, including thickness characteristics and line-width effects on detection limits, linear range and interference immunity with membranes coated by micropipette/spin-coating and focus-ion-beam (FIB processed capillary atomic-force-microscopy (C-AFM tip scan/coating methods. The PSW surface was modified with a mixture of 3-aminopropyl-triethoxysilane (γ-APTES and polydimethylsiloxane (PDMS-treated hydrophobic fumed silica nanoparticles (NPs. We found that the thickness of the γ-APTES+NPs nonocomposite could be controlled well at about 22 nm with small relative standard deviation (RSD with repeated C-AFM tip scan/coatings. The detection limit increased and linear range decreased with the line width of the PSW through the tip-coating process. Interestingly, the interference immunity ability improves as the line width increases. For a 500 nm-wide PSW, the percentage changes of the channel current density changes (ΔJ caused by acetaminophen (AP can be kept below 3.5% at an ultra-high AP-to-glucose concentration ratio of 600:1. Simulation results showed that the line width dependence of interference immunity was strongly correlated with the channel electrical field of the PSW biosensor.

APT Blanket System Loss-of-Flow Accident (LOFA) Analysis Based on Initial Conceptual Design - Case 1: with Beam Shutdown and Active RHR

International Nuclear Information System (INIS)

Hamm, L.L.

1998-01-01

This report is one of a series of reports that document normal operation and accident simulations for the Accelerator Production of Tritium (APT) blanket heat removal system. These simulations were performed for the Preliminary Safety Analysis Report

Optimization and characterization of biomolecule immobilization on silicon substrates using (3-aminopropyl)triethoxysilane (APTES) and glutaraldehyde linker

International Nuclear Information System (INIS)

Gunda, Naga Siva Kumar; Singh, Minashree; Norman, Lana; Kaur, Kamaljit; Mitra, Sushanta K.

2014-01-01

In the present work, we developed and optimized a technique to produce a thin, stable silane layer on silicon substrate in a controlled environment using (3-aminopropyl)triethoxysilane (APTES). The effect of APTES concentration and silanization time on the formation of silane layer is studied using spectroscopic ellipsometry and Fourier transform infrared spectroscopy (FTIR). Biomolecules of interest are immobilized on optimized silane layer formed silicon substrates using glutaraldehyde linker. Surface analytical techniques such as ellipsometry, FTIR, contact angle measurement system, and atomic force microscopy are employed to characterize the bio-chemically modified silicon surfaces at each step of the biomolecule immobilization process. It is observed that a uniform, homogenous and highly dense layer of biomolecules are immobilized with optimized silane layer on the silicon substrate. The developed immobilization method is successfully implemented on different silicon substrates (flat and pillar). Also, different types of biomolecules such as anti-human IgG (rabbit monoclonal to human IgG), Listeria monocytogenes, myoglobin and dengue capture antibodies were successfully immobilized. Further, standard sandwich immunoassay (antibody–antigen–antibody) is employed on respective capture antibody coated silicon substrates. Fluorescence microscopy is used to detect the respective FITC tagged detection antibodies bound to the surface after immunoassay.

Optimization and characterization of biomolecule immobilization on silicon substrates using (3-aminopropyl)triethoxysilane (APTES) and glutaraldehyde linker

Energy Technology Data Exchange (ETDEWEB)

Gunda, Naga Siva Kumar [Department of Mechanical Engineering, University of Alberta, Edmonton, Canada T6G 2G8 (Canada); Singh, Minashree [Department of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada T6G 1C9 (Canada); Norman, Lana [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada T6G 2V4 (Canada); Kaur, Kamaljit [Department of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada T6G 1C9 (Canada); Mitra, Sushanta K., E-mail: sushanta.mitra@ualberta.ca [Department of Mechanical Engineering, University of Alberta, Edmonton, Canada T6G 2G8 (Canada)

2014-06-01

In the present work, we developed and optimized a technique to produce a thin, stable silane layer on silicon substrate in a controlled environment using (3-aminopropyl)triethoxysilane (APTES). The effect of APTES concentration and silanization time on the formation of silane layer is studied using spectroscopic ellipsometry and Fourier transform infrared spectroscopy (FTIR). Biomolecules of interest are immobilized on optimized silane layer formed silicon substrates using glutaraldehyde linker. Surface analytical techniques such as ellipsometry, FTIR, contact angle measurement system, and atomic force microscopy are employed to characterize the bio-chemically modified silicon surfaces at each step of the biomolecule immobilization process. It is observed that a uniform, homogenous and highly dense layer of biomolecules are immobilized with optimized silane layer on the silicon substrate. The developed immobilization method is successfully implemented on different silicon substrates (flat and pillar). Also, different types of biomolecules such as anti-human IgG (rabbit monoclonal to human IgG), Listeria monocytogenes, myoglobin and dengue capture antibodies were successfully immobilized. Further, standard sandwich immunoassay (antibody–antigen–antibody) is employed on respective capture antibody coated silicon substrates. Fluorescence microscopy is used to detect the respective FITC tagged detection antibodies bound to the surface after immunoassay.

The mediation as an apt tool for the prevention of crime as result of gender violence

OpenAIRE

Yaíma Águila Gutiérrez; Marileydis Pino Rosa

2017-01-01

Violence based in gender is an actual, social, historical and cultural matter. It affects to million persons around the world in the personal, familiar and social ambit. Violence based in gender could damage relationships and also could become in a crime. Mediation is an apt tool to use before the intervention of law for solving gender violence´s conflicts which could need the intervention of criminal law. Those reasons show that is necessary the prevention of gender violence so is important ...

Development of a raster electronics system for expanding the APT proton beam

Energy Technology Data Exchange (ETDEWEB)

Chapelle, S.; Hubbard, E.L.; Smith, T.L. [General Atomics, San Diego, CA (United States); Schulze, M.E.; Shafer, R.E. [General Atomics, Los Alamos, NM (United States)

1998-12-31

A 1700 MeV, 100 mA proton linear accelerator is being designed for Accelerator Production of Tritium (APT). A beam expansion system is required to uniformly irradiate a 19 x 190 cm tritium production target. This paper describes a beam expansion system consisting of eight ferrite dipole magnets to raster the beam in the x- and y-planes and also describes the salient features of the design of the electronics that are unique to the expander. Eight Insulated Gate Bipolar Transistor (IGBT)-based modulators drive the raster magnets with triangular current waveforms that are synchronized using phase-locked loops (PLLs) and voltage controlled crystal oscillators (VCXOs). Fault detection circuitry shuts down the beam before the target can be damaged by a failure of the raster system. Test data are presented for the prototype system.

The mediation as an apt tool for the prevention of crime as result of gender violence

Directory of Open Access Journals (Sweden)

Yaíma Águila Gutiérrez

2017-07-01

Full Text Available Violence based in gender is an actual, social, historical and cultural matter. It affects to million persons around the world in the personal, familiar and social ambit. Violence based in gender could damage relationships and also could become in a crime. Mediation is an apt tool to use before the intervention of law for solving gender violence´s conflicts which could need the intervention of criminal law. Those reasons show that is necessary the prevention of gender violence so is important the intervention of criminology.

Los Modelos CAPM y APT para la valuacion de empresas de Telecomunicaciones con parametros operativos

Directory of Open Access Journals (Sweden)

Saldaña, J.

2007-07-01

Full Text Available One of the most important research topics in the financial area during de the last years has been the capital assets appraisal or the appraise of shares. This seeks two determine the explanatory factor of the rate of return for a specific portfolio. The CAPM (Capital Asset Pricing Model and the APT (Arbitrage Pricing Theory, both capital asset evaluation models, are hereby presented. The main characteristics of both models are the essential assumptions for their for there development, their statement and the practical test on the telecommunications portfolio using operational, financial and macroeconomics variable, and carried on with the purpose to be compare with reality.

Revealed or hidden?: insights into ways of measuring mental representations online: A comparative study of APT and CNET applied to an online agent

NARCIS (Netherlands)

Horeni, O.; Arentze, T.A.; Dellaert, B.G.C.; Timmermans, H.J.P.

2010-01-01

This paper presents and compares newly developed interview techniques (APT and CNET) which were implemented and tested by an online agent in order to measure mental representations underlying activity-choices. The comparison is supported and completed by the results from a first online survey with

Thermal-hydraulic criteria for the APT tungsten neutron source design

International Nuclear Information System (INIS)

Pasamehmetoglu, K.

1998-03-01

This report presents the thermal-hydraulic design criteria (THDC) developed for the tungsten neutron source (TNS). The THDC are developed for the normal operations, operational transients, and design-basis accidents. The requirements of the safety analyses are incorporated into the design criteria, consistent with the integrated safety management and the safety-by-design philosophy implemented throughout the APT design process. The phenomenology limiting the thermal-hydraulic design and the confidence level requirements for each limit are discussed. The overall philosophy of the uncertainty analyses and the confidence level requirements also are presented. Different sets of criteria are developed for normal operations, operational transients, anticipated accidents, unlikely accidents, extremely unlikely accidents, and accidents during TNS replacement. In general, the philosophy is to use the strictest criteria for the high-frequency events. The criteria is relaxed as the event frequencies become smaller. The THDC must be considered as a guide for the design philosophy and not as a hard limit. When achievable, design margins greater than those required by the THDC must be used. However, if a specific event sequence cannot meet the THDC, expensive design changes are not necessary if the single event sequence results in sufficient margin to safety criteria and does not challenge the plant availability or investment protection considerations

Micah 7:8-20: An apt conclusion to the book of Micah

Directory of Open Access Journals (Sweden)

W J Wessels

2003-10-01

Full Text Available It is argued in this article that Micah 7:8-20 forms an apt conclusion to the book of Micah. As was the case with Micah 1, the concluding section also focusses on Yahweh and his dealings with the people of the earth. There is a universal tendency to be detected in this section as well. An important aspect to notice� is� the liturgical nature of chapters six and seven, especially 7:8-20. There is a vagueness, almost a timelessness, imbuing this section. This could be intended allowing later generations of believers to apply these words to� their� own� circumstances. With Micah 7:8-20 as the concluding section of the book, one is left with a sense of well-roundedness, of completeness. The collection of oracles attributed� to Micah in general has a sombre tone. For this very reason Micah� 7:8-20� seems� to� change� the mood. It breathes hope into a negative atmosphere of judgment. It ends with a strong emphasis on the power of Yahweh, the power of forgiveness.

Development of the SCRF Power Coupler for the APT Accelerator

Energy Technology Data Exchange (ETDEWEB)

Schmierer, E.N.; Lujan, R.E.; Rusnak, B.; Smith, B.; Haynes, W.B.; Gautier, C.; Waynert, J.A.; Krawczyk, F.; Gioia, J.

1999-03-01

The team responsible for the design of the Accelerator Production of Tritium (APT) superconducting (SC) radio frequency (RF) power coupler has developed two 700-MHz, helium gas-cooled power couplers. One has a fixed inner conductor and the other has an adjustable inner conductor (gamma prototype and alpha prototype). The power couplers will be performance tested in the near future. This paper discusses the mechanical design and fabrication techniques employed in the development of each power coupler. This includes material selection, copper coating, assembly sequences, and metal joining procedures, as well as the engineering analyses performed to determine the dynamic response of the inner conductors due to environmental excitations. A bellows is used in both prototype inner conductors in the area near the ceramic RF window, to compensate for thermal expansion and mechanical tolerance build-up. In addition, a bellows is used near the tip of the inner conductor of the alpha prototype for running the power coupler after it is installed on the accelerator. Extensive analytical work has been performed to determine the static loads transmitted by the bellows due to thermally induced expansion on the inner conductor and on the RF window. This paper also discusses this analysis, as well as the mechanical analysis performed to determine the final geometric shape of the bellows. Finally, a discussion of the electromagnetic analysis used to optimize the performance of the power couplers is included.

Chemotherapy-related amenorrhea after adjuvant paclitaxel-trastuzumab (APT trial).

Science.gov (United States)

Ruddy, Kathryn J; Guo, Hao; Barry, William; Dang, Chau T; Yardley, Denise A; Moy, Beverly; Marcom, P Kelly; Albain, Kathy S; Rugo, Hope S; Ellis, Matthew J; Shapira, Iuliana; Wolff, Antonio C; Carey, Lisa A; Overmoyer, Beth A; Hudis, Clifford; Krop, Ian E; Burstein, Harold J; Winer, Eric P; Partridge, Ann H; Tolaney, Sara M

2015-06-01

Chemotherapy-related amenorrhea (CRA) is associated with infertility and menopausal symptoms. Learning how frequently paclitaxel and trastuzumab cause amenorrhea is important. Most other adjuvant breast cancer therapies induce CRA in approximately 50 % of all premenopausal recipients [1]. 410 patients enrolled on the APT Trial, a single-arm phase 2 adjuvant study of 12 weeks of paclitaxel and trastuzumab followed by nine months of trastuzumab monotherapy. Eligible patients had ≤3 cm node-negative HER2 + breast cancers. Premenopausal enrollees were asked to complete menstrual surveys every 3-12 months for 72 months. Women who responded to at least one survey at least 15 months after chemotherapy initiation (and who did not undergo hysterectomy and/or bilateral oophorectomy or receive ovarian suppressing medications prior to 15 months) were included in this analysis. A participant was defined as having amenorrhea in follow-up if her self-reported last menstrual period at last follow-up was greater than 12 months prior to the survey. Among the 64 women in the evaluable population (median age at study entry 44 years, range 27-52 years), the median time between chemotherapy initiation and last menstrual survey was 51 months (range 16-79). 18 of 64 women (28 %, 95 % CI 18-41 %) were amenorrheic at that time point. Amenorrhea rates among premenopausal women treated with adjuvant paclitaxel and trastuzumab for early stage breast cancer appear lower than those seen historically with standard alkylator-based breast cancer regimens. Future studies are needed to understand the impact of this regimen on related issues of fertility and menopausal symptoms.

Microradiographic investigations on experimentally provoked structural alterations in hard tooth tissues after sealing with plastic material in places where caries is apt to develop

International Nuclear Information System (INIS)

Falten, E.

1981-01-01

The aim of the present investigation was, after sealing three areas in extracted human teeth: fissures, dental necksand approximate areas and subsequent exposure to experimentally produced cariogenous noxae, to establish possible alterations in the area of transition between sealed and unsealed dental enamal. This would provide a further decision-taking aid with regard to the question whether also the remaining parts where caries is apt to develop should be sealed. (orig./MG) [de

Surface modification of TiO2 nanotubes by grafting with APTS coupling agents

Science.gov (United States)

Phan Duong, Hong; Le, Minh Duc; Dao, Hung Cuong; Chen, Chia-Yun

2017-10-01

Titanium dioxide nanotubes (TNTs) have been considered the promising nanostructures employed for many practical applications such as biomedical, photonic and optoelectronic devices. Nevertheless, strong aggregation of TNTs within various aqueous media significantly hindered their practical utilizations and the capability of dispersing TNTs in the desired solvents are urgent to be improved. Therefore, in this study, the methodic investigations have been performed on the grafted modification of 3-aminopropyl triethoxysilane (APTS) on the surfaces of synthesized TNTs. A preliminary study was carried out to evaluate the influences of key parameters, including the concentrations of coupling agents, temperatures and the reaction durations, on the grafting efficiency of the aminosilane using Statistical design of experiments (DoE) methodology. TNTs with approximately 10-20 nm in diameter were prepared with the controlled hydrothermal treatment of commercialized P25 particles. The obtained products were revealed by the modern physicochemical systems including x-ray diffraction (XRD), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) analysis. The additions of silane agent, reaction temperature and time have been adjusted to reveal the influences of the grafting efficiency (from 2.5 to 7.8 wt %) by thermal gravimetric analysis (TGA). Analysis of Fourier transform infrared spectroscopy (FTIR) has confirmed the successful link of Ti-O-Si chemical bonds on the grafted TNTs.

Associated Particle Tagging (APT) in Magnetic Spectrometers

Energy Technology Data Exchange (ETDEWEB)

Jordan, David V.; Baciak, James E.; Stave, Sean C.; Chichester, David; Dale, Daniel; Kim, Yujong; Harmon, Frank

2012-10-16

Summary In Brief The Associated Particle Tagging (APT) project, a collaboration of Pacific Northwest National Laboratory (PNNL), Idaho National Laboratory (INL) and the Idaho State University (ISU)/Idaho Accelerator Center (IAC), has completed an exploratory study to assess the role of magnetic spectrometers as the linchpin technology in next-generation tagged-neutron and tagged-photon active interrogation (AI). The computational study considered two principle concepts: (1) the application of a solenoidal alpha-particle spectrometer to a next-generation, large-emittance neutron generator for use in the associated particle imaging technique, and (2) the application of tagged photon beams to the detection of fissile material via active interrogation. In both cases, a magnetic spectrometer momentum-analyzes charged particles (in the neutron case, alpha particles accompanying neutron generation in the D-T reaction; in the tagged photon case, post-bremsstrahlung electrons) to define kinematic properties of the relevant neutral interrogation probe particle (i.e. neutron or photon). The main conclusions of the study can be briefly summarized as follows: Neutron generator: • For the solenoidal spectrometer concept, magnetic field strengths of order 1 Tesla or greater are required to keep the transverse size of the spectrometer smaller than 1 meter. The notional magnetic spectrometer design evaluated in this feasibility study uses a 5-T magnetic field and a borehole radius of 18 cm. • The design shows a potential for 4.5 Sr tagged neutron solid angle, a factor of 4.5 larger than achievable with current API neutron-generator designs. • The potential angular resolution for such a tagged neutron beam can be less than 0.5o for modest Si-detector position resolution (3 mm). Further improvement in angular resolution can be made by using Si-detectors with better position resolution. • The report documents several features of a notional generator design incorporating the

Topical report on a preconceptual design for the Spallation-Induced Lithium Conversion (SILC) target for the accelerator production of tritium (APT)

International Nuclear Information System (INIS)

Van Tuyle, G.J.; Cokinos, D.M.; Czajkowski, C.; Franz, E.M.; Kroeger, P.; Todosow, M.; Youngblood, R.; Zucker, M.

1993-01-01

The preconceptual design of the APT Li-Al target system, also referred to as the Spallation-Induced Lithium Conversion (SILC), target system, is summarized in this report. The system has been designed to produce a ''3/8 Goal'' quantity of tritium using the 200-mA, 1.0 GeV proton beam emerging from the LANL-designed LINAC. The SILC target system consists of a beam expander, a heavy-water-cooled lead spallation neutron source assembly surrounded by light-water-cooled Li-Al blankets, a target window, heat removal systems, and related safety systems. The preconceptual design of each of these major components is described. Descriptions are also provided for the target fabrication, tritium extraction, and waste-steam processes. Performance characteristics are presented and discussed

Topical report on a preconceptual design for the Spallation-Induced Lithium Conversion (SILC) target for the accelerator production of tritium (APT)

Energy Technology Data Exchange (ETDEWEB)

Van Tuyle, G.J.; Cokinos, D.M.; Czajkowski, C.; Franz, E.M.; Kroeger, P.; Todosow, M.; Youngblood, R.; Zucker, M.

1993-09-30

The preconceptual design of the APT Li-Al target system, also referred to as the Spallation-Induced Lithium Conversion (SILC), target system, is summarized in this report. The system has been designed to produce a ``3/8 Goal`` quantity of tritium using the 200-mA, 1.0 GeV proton beam emerging from the LANL-designed LINAC. The SILC target system consists of a beam expander, a heavy-water-cooled lead spallation neutron source assembly surrounded by light-water-cooled Li-Al blankets, a target window, heat removal systems, and related safety systems. The preconceptual design of each of these major components is described. Descriptions are also provided for the target fabrication, tritium extraction, and waste-steam processes. Performance characteristics are presented and discussed.

First Characterization of the Ultra-Shielded Chamber in the Low-noise Underground Laboratory (LSBB) of Rustrel Pays d'Apt

CERN Document Server

Waysand, G; Bongiraud, J P; Collar, J I; Dolabdjian, C; Le Thiec, P; Thiec, Ph. Le

2000-01-01

In compliance with international agreements on nuclear weapons limitation, the French ground-based nuclear arsenal has been decommissioned in its totality. One of its former underground missile control centers, located in Rustrel, 60 km east of Avignon (Provence) has been converted into the ``Laboratoire Souterrain à Bas Bruit de Rustrel-Pays d'Apt'' (LSBB). The deepest experimental hall (500 m of calcite rock overburden) includes a 100 m$^{2}$ area of sturdy flooring suspended by and resting on shock absorbers, entirely enclosed in a 28 m-long, 8 m-diameter, 1 cm-thick steel Faraday cage. This results in an unparalleled combination of shielding against cosmic rays, acoustic, seismic and electromagnetic noise, which can be exploited for rare event searches using ultra low-temperature and superconducting detectors. The first characterization measurements in this unique civilian site are reported. http://www.gps.jussieu.fr/RUSTREL/rustrel.html

Functionalization of Fe3O4 NPs by Silanization: Use of Amine (APTES and Thiol (MPTMS Silanes and Their Physical Characterization

Directory of Open Access Journals (Sweden)

Silvia Villa

2016-10-01

Full Text Available In this paper the results concerning the synthesis of magnetite (Fe3O4 nanoparticles (NPs, their functionalization using silane derivatives, such as (3-Aminopropyltriethoxysilane (APTES and (3-mercaptopropyltrimethoxysilane (MPTMS, and their exhaustive morphological and physical characterization by field emission scanning electron microscopy (FE-SEM with energy dispersion X-ray spectrometer (EDX analysis, AC magnetic susceptibility, UV-VIS and IR spectroscopy, and thermogravimetric (TGA analyses are reported. Two different paths were adopted to achieve the desired functionalization: (1 the direct reaction between the functionalized organo-silane molecule and the surface of the magnetite nanoparticle; and (2 the use of an intermediate silica coating. Finally, the occurrence of both the functionalization with amino and thiol groups has been demonstrated by the reaction with ninhydrin and the capture of Au NPs, respectively.

Quantitative description of proton exchange processes between water and endogenous and exogenous agents for WEX, CEST, and APT experiments.

Science.gov (United States)

Zhou, Jinyuan; Wilson, David A; Sun, Phillip Zhe; Klaus, Judith A; Van Zijl, Peter C M

2004-05-01

The proton exchange processes between water and solutes containing exchangeable protons have recently become of interest for monitoring pH effects, detecting cellular mobile proteins and peptides, and enhancing the detection sensitivity of various low-concentration endogenous and exogenous species. In this work, the analytic expressions for water exchange (WEX) filter spectroscopy, chemical exchange-dependent saturation transfer (CEST), and amide proton transfer (APT) experiments are derived by the use of Bloch equations with exchange terms. The effects of the initial states for the system, the difference between a steady state and a saturation state, and the relative contributions of the forward and backward exchange processes are discussed. The theory, in combination with numerical calculations, provides a useful tool for designing experimental schemes and assessing magnetization transfer (MT) processes between water protons and solvent-exchangeable protons. As an example, the case of endogenous amide proton exchange in the rat brain at 4.7 T is analyzed in detail. Copyright 2004 Wiley-Liss, Inc.

Vaporization of mercury from molten lead droplets doped with mercury: Pb/Hg source term experiment for the APT/SILC target

International Nuclear Information System (INIS)

Tutu, N.K.; Greene, G.A.

1994-09-01

Experiments were performed to measure the fraction of mercury inventory released when droplets of molten lead, doped with a known concentration of mercury, fall through a controlled environment. The temperature of molten droplets ranged from 335 C to 346 C, and the concentration of mercury in the droplets ranged from 0.2 mass % to 1.0 mass %. The environment consisted of an air stream, at a temperature nominally equal to the melt temperature, and moving vertically upwards at a velocity of 10 cm/s. Direct observations and chemical analysis showed that no mercury was released from the molten droplets. Based upon the experimental results, it is concluded that no mercury vapor is likely to be released from the potentially molten source rod material in the APT-SILC Neutron Source Array to the confinement atmosphere during a postulated Large Break Loss Of Coolant Accident scenario leading to the melting of a fraction of the source rods

Study on usability of Fusarium oxysporum Schlecht.f.sp. tulipae Apt. metabolites for screening for basal rot resistance in tulip

Directory of Open Access Journals (Sweden)

Małgorzata Podwyszyńska

2013-12-01

Full Text Available The usefulness of fungus culture filtrates and fusaric acid as selecting agents for Fusarium resistance breeding in tulip was examined on in vitro cultures of shoots and embryonic calli of seven tulip genotypes differing in resistance to Fusarium oxysporum Schlecht. f. sp. tulipae Apt. (F.o.t. and four virulent F.o.t. isolates. Fusaric acid influenced the shoot growth of all cultivars tested in a similar way, irrespectively of their greenhouse resistance to basal rot. Also, the sensitivity of calli of the cultivars studied to fusaric acid did not correspond with their resistance to F.o.t. evaluated in the greenhouse screening. The phytotoxity of F.o.t. culture filtrates did not depend on their fusaric acid contents. There was a negative correlation between cultivar's resistance to F.o.t in greenhouse tests and the sensitivity of their shoots to fungus culture filtrates in in vitro tests. This indicates that defence mechanism against F.o.t. in tulip tissue may have a nature of hypersensitive response. Considering the results of our study, it may be concluded that the use of fusaric acid or fungus culture filtrates for the in vitro selection of somaclones resistant to F.o.t. in tulip is not feasible.

Astrometry, Radial Velocity, and Photometry: The HD 128311 System Remixed with Data from HST, HET, and APT

Science.gov (United States)

McArthur, Barbara. E.; Benedict, G. Fritz; Henry, Gregory W.; Hatzes, Artie; Cochran, William D.; Harrison, Tom E.; Johns-Krull, Chris; Nelan, Ed

2014-11-01

We have used high-cadence radial velocity measurements from the Hobby-Eberly Telescope with published velocities from the Lick 3 m Shane Telescope, combined with astrometric data from the Hubble Space Telescope (HST) Fine Guidance Sensors to refine the orbital parameters of the HD 128311 system, and determine an inclination of 55.°95 ± 14.°55 and true mass of 3.789 +0.924 -0.432 M JUP for HD 128311 c. The combined radial velocity data also reveal a short period signal which could indicate a third planet in the system with an Msin i of 0.133 ± 0.005 M JUP or stellar phenomena. Photometry from the T12 0.8 m automatic photometric telescope at the Fairborn Observatory and HST are used to determine a photometric period close to, but not within the errors of the radial velocity signal. We performed a cross-correlation bisector analysis of the radial velocity data to look for correlations with the photometric period and found none. Dynamical integrations of the proposed system show long-term stability with the new orbital parameters of over 10 million years. Our new orbital elements do not support the claims of HD 128311 b and c being in mean motion resonance. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Based on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen, and observations with T12 0.8 m automatic photoelectric telescope (APT) at Fairborn Observatory.

Removal of cadmium (II) from aqueous solution: A comparative study of raw attapulgite clay and a reusable waste–struvite/attapulgite obtained from nutrient-rich wastewater

Energy Technology Data Exchange (ETDEWEB)

Wang, Hao [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Wang, Xuejiang, E-mail: wangxj@tongji.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Ma, Jinxing, E-mail: jinxing.ma@unsw.edu.au [School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Xia, Peng; Zhao, Jianfu [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China)

2017-05-05

Highlights: • Both nutrient recovery and Cd(II) removal were achieved by MAP/APT. • The nutrient recovery process was used as a novel method of modification. • Compared with raw APT, MAP/APT enhanced Cd(II) adsorption capacity. • Cd(II) adsorption mechanisms from aqueous solution were extensively investigated. - Abstract: In this study, raw attapulgite (APT) and a novel adsorbent, struvite/attapulgite (MAP/APT) obtained from nutrient-rich wastewater treated by MgO modified APT, were applied as the absorbent for Cd(II) ion removal from aqueous solution. The two adsorbents were characterized by BET, SEM-EDS, XRD, FT-IR. Raw APT and MAP/APT separately presented the maximum Cd(II) adsorption capacities of 10.38 mg/g and 121.14 mg/g at pH of 5.45. The Cd(II) adsorption on raw APT and MAP/APT could be well fitted by Freundlich isotherm and Langmuir isotherm, respectively. Pseudo-second order equation was able to properly describe the kinetics of Cd(II) adsorption by raw APT and MAP/APT. The calculated thermodynamic parameters indicated that Cd(II) adsorption onto raw APT and MAP/APT were spontaneous and endothermic. An economic evaluation revealed that the treatment costs of the adsorption process by raw APT and MPA/APT were 0.013 $ per 1000 mg Cd and 0.004 $ per 1000 mg Cd, respectively.

End-to-End Deep Neural Networks and Transfer Learning for Automatic Analysis of Nation-State Malware

Directory of Open Access Journals (Sweden)

Ishai Rosenberg

2018-05-01

Full Text Available Malware allegedly developed by nation-states, also known as advanced persistent threats (APT, are becoming more common. The task of attributing an APT to a specific nation-state or classifying it to the correct APT family is challenging for several reasons. First, each nation-state has more than a single cyber unit that develops such malware, rendering traditional authorship attribution algorithms useless. Furthermore, the dataset of such available APTs is still extremely small. Finally, those APTs use state-of-the-art evasion techniques, making feature extraction challenging. In this paper, we use a deep neural network (DNN as a classifier for nation-state APT attribution. We record the dynamic behavior of the APT when run in a sandbox and use it as raw input for the neural network, allowing the DNN to learn high level feature abstractions of the APTs itself. We also use the same raw features for APT family classification. Finally, we use the feature abstractions learned by the APT family classifier to solve the attribution problem. Using a test set of 1000 Chinese and Russian developed APTs, we achieved an accuracy rate of 98.6%

Feasibility study of Anti-MUC1 aptamer use as vector target director of 1,10 phenantrolin for radiosensitization of breast cancer cells; Estudo da viabilidade do uso do aptâmero Anti-MUC1 como vetor alvo direcionador de 1,10 fenantrolina para radio sensibilização de células de câncer de mama

Energy Technology Data Exchange (ETDEWEB)

Alves, Laís Nascimento

2017-07-01

With the rising incidence of cancer and this disease as global public health dilemma, there is an alarming need of studying new cancer therapies. To achieve the development of efficient agents is essential to understand the fundamental mechanisms of carcinogenesis and tumor progression. Overexpression of proteins in malignant tissues, in contrast to expression of the proteins found in normal tissues of the same organ, is crucially important and of great interest for the characterization of potential tumor biomarkers. Following this premise, MUC1 glycoprotein was selected as a therapeutic target in a breast cancer model. In order to determine the viability of the aptA aptamer as radiosensitizers carrier, the toxic compound 1,10 phenanthroline, complexed with Fe(II) was intercalated in the aptamers. The dissociation constant was found at a value of Kd = 30 μM. The selective binding and internalization of the compound was demonstrated. Based on these data, the aptA can be used as carrying vector of molecules such as 1,10-phenanthroline. As a next stage, the evaluation of its in vitro potential as radiosensitizers with the use of ionizing radiation will be done. (author)

Stability Modification of SPR Silver Nano-Chips by Alkaline Condensation of Aminopropyltriethoxysilane

Directory of Open Access Journals (Sweden)

M. Ghorbanpour

2015-04-01

Full Text Available The Silver SPR chip was modified by alkaline-silane condensation with aminopropyltriethoxysilane (APTES in NaOH aqueous solution at different times. Silver sputtered slides coated with APTES were immersed in NaOH solution, enabling us to produce silver surfaces homogeneously covered with APTES. The surface properties of grafted APTES on sputtered silver surface as a occasion of time were studied using SPR analysis, AFM and contact angle measurement. The mechanical and chemical stability of samples was assayed by tape test and NaCl test. The answers show that hydrolysis and condensation of APTES are activated in alkaline solution and lead to formation of a protective APTES layer on the surface of silver. The morphology of APTES on silver surface is a function of coverage density that is altered by changing time. At short times (< 30 min, APTES molecules physically adsorb to the surface leads to weak protection. At higher condensation times, APTES molecules chemically bond to the surface and each other leads to better protection.

DNA aptamer functionalized gold nanostructures for molecular recognition and photothermal inactivation of methicillin-Resistant Staphylococcus aureus.

Science.gov (United States)

Ocsoy, Ismail; Yusufbeyoglu, Sadi; Yılmaz, Vedat; McLamore, Eric S; Ildız, Nilay; Ülgen, Ahmet

2017-11-01

In this work, we report the development of DNA aptamer-functionalized gold nanoparticles (Apt@Au NPs) and gold nanorods (Apt@Au NRs) for inactivation of Methicillin-resistant Staphylococcus aureus (MRSA) with targeted photothermal therapy (PTT). Although both Apt@Au NPs and Apt@Au NRs specifically bind to MRSA cells, Apt@Au NPs and Apt@Au NRs inactivated ∼5% and over 95% of the cells,respectively through PTT. This difference in inactivation was based on the relatively high longitudinal absorption of near-infrared (NIR) radiation and strong photothermal conversion capability for the Apt@Au NRs compared to the Apt@Au NPs. The Au NRs served as a nanoplatform for the loading of thiolated aptamer and also provided multivalent effects for increasing binding strength and affinity to MRSA. Our results indicate that the type of aptamer and the degree of multivalent effect(s) are important factors for MRSA inactivation efficiency in PTT. We show that the Apt@Au NRs are a very effective and promising nanosystem for specific cell recognition and in vitro PTT. Copyright © 2017 Elsevier B.V. All rights reserved.

Defending against the Advanced Persistent Threat: An Optimal Control Approach

Directory of Open Access Journals (Sweden)

Pengdeng Li

2018-01-01

Full Text Available The new cyberattack pattern of advanced persistent threat (APT has posed a serious threat to modern society. This paper addresses the APT defense problem, that is, the problem of how to effectively defend against an APT campaign. Based on a novel APT attack-defense model, the effectiveness of an APT defense strategy is quantified. Thereby, the APT defense problem is modeled as an optimal control problem, in which an optimal control stands for a most effective APT defense strategy. The existence of an optimal control is proved, and an optimality system is derived. Consequently, an optimal control can be figured out by solving the optimality system. Some examples of the optimal control are given. Finally, the influence of some factors on the effectiveness of an optimal control is examined through computer experiments. These findings help organizations to work out policies of defending against APTs.

Peroxotitanates for Biodelivery of Metals

Energy Technology Data Exchange (ETDEWEB)

Hobbs, David; Elvington, M.

2009-02-11

Metal-based drugs are largely undeveloped in pharmacology. One limiting factor is the systemic toxicity of metal-based compounds. A solid-phase, sequestratable delivery agent for local delivery of metals could reduce systemic toxicity, facilitating new drug development in this nascent area. Amorphous peroxotitanates (APT) are ion exchange materials with high affinity for several heavy metal ions, and have been proposed to deliver or sequester metal ions in biological contexts. In the current study, we tested a hypothesis that APT are able to deliver metals or metal compounds to cells. We exposed fibroblasts (L929) or monocytes (THP1) to metal-APT materials for 72 h in vitro, then measured cellular mitochondrial activity (SDH-MTT method) to assess the biological impact of the metal-APT materials vs. metals or APT alone. APT alone did not significantly affect cellular mitochondrial activity, but all metal-APT materials suppressed the mitochondrial activity of fibroblasts (by 30-65% of controls). The concentration of metal-APT materials required to suppress cellular mitochondrial activity was below that required for metals alone, suggesting that simple extracellular release of the metals from the metal-APT materials was not the primary mechanism of mitochondrial suppression. In contrast to fibroblasts, no metal-APT material had a measurable effect on THP1 monocyte mitochondrial activity, despite potent suppression by metals alone. This latter result suggested that 'biodelivery' by metal-APT materials may be cell type-specific. Therefore, it appears that APT are plausible solid phase delivery agents of metals or metal compounds to some types of cells for potential therapeutic effect.

Development of an activity-based probe for acyl-protein thioesterases

Science.gov (United States)

Garland, Megan; Schulze, Christopher J.; Foe, Ian T.; van der Linden, Wouter A.; Child, Matthew A.

2018-01-01

Protein palmitoylation is a dynamic post-translational modification (PTM) important for cellular functions such as protein stability, trafficking, localization, and protein-protein interactions. S-palmitoylation occurs via the addition of palmitate to cysteine residues via a thioester linkage, catalyzed by palmitoyl acyl transferases (PATs), with removal of the palmitate catalyzed by acyl protein thioesterases (APTs) and palmitoyl-protein thioesterases (PPTs). Tools that target the regulators of palmitoylation–PATs, APTs and PPTs–will improve understanding of this essential PTM. Here, we describe the synthesis and application of a cell-permeable activity-based probe (ABP) that targets APTs in intact mammalian cells and the parasite Toxoplasma gondii. Using a focused library of substituted chloroisocoumarins, we identified a probe scaffold with nanomolar affinity for human APTs (HsAPT1 and HsAPT2) and synthesized a fluorescent ABP, JCP174-BODIPY TMR (JCP174-BT). We use JCP174-BT to profile HsAPT activity in situ in mammalian cells, to detect an APT in T. gondii (TgPPT1). We show discordance between HsAPT activity levels and total protein concentration in some cell lines, indicating that total protein levels may not be representative of APT activity in complex systems, highlighting the utility of this probe. PMID:29364904

Surface functionalization of zirconium dioxide nano-adsorbents with 3-aminopropyl triethoxysilane and promoted adsorption activity for bovine serum albumin

International Nuclear Information System (INIS)

Liu, Gen; Wu, Chaochao; Zhang, Xia; Liu, Yufeng; Meng, Hao; Xu, Junli; Han, Yide; Xu, Xinxin; Xu, Yan

2016-01-01

Surface functionalization of zirconium dioxide (ZrO_2) nano-adsorbents was carried out by using 3-aminopropyl triethoxysilane (APTES) as the modifier. The addition amount of APTES was varied to determine the optimum modification extent, and the bulk ZrO_2 microparticles were also modified by APTES for comparison. Some means, such as TEM, XRD, FT-IR, XPS and TG-DSC were used to character these ZrO_2 particles. The results showed that the APTES molecules were chemically immobilized on the surface of ZrO_2 nanoparticles via Zr−O−Si bonds, and the nano-ZrO_2 samples showed larger special surface area. In the adsorption of bovine serum albumin (BSA), nano-ZrO_2 samples exhibited enhanced adsorption activity, and APTES modified nano-ZrO_2 with proper APTES content presented the best adsorption property. Under the same adsorption conditions, the equilibrium adsorption capacity of BSA on APTES-ZrO_2-2 was almost 2.3 times as that on pristine nano-ZrO_2 and 3.0 times as on bulk ZrO_2 microparticles. The increased adsorption capacity of APTES-ZrO_2 nano-adsorbents can be attributed to the chemical interaction between amino and carboxyl groups at APTES-ZrO_2/BSA interface. The pH-dependent experiments showed that the optimum pH value for the adsorption and desorption was 5.0 and 9.0, respectively, which suggested that the adsorption and release of BSA could be controlled simply by adjusting the solution pH condition. - Highlights: • APTES chemically immobilized on ZrO_2 nanoparticles via Zr−O−Si bond. • Enhanced adsorption capacity of BSA was observed on APTES-ZrO_2. • Chemical adsorption character of BSA on APTES-ZrO_2. • Adsorption/release of BSA on APTES-ZrO_2 accomplished by adjusting pH value.

Impedimetric Zika and Dengue Biosensor based on Functionalized Graphene Oxide Wrapped Silica Particles

Science.gov (United States)

Jin, Seon-Ah; Marinero, Ernesto E.; Stanciu, Lia A. Stanciu; Poudyal, Shishir; Kuhn, Richard J.

A composite of 3-Aminopropyltriethoxysilane (APTES) functionalized graphene oxide (APTES-GO) wrapped on SiO2 particles (SiO2@APTES-GO) was prepared via self-assembly. Transmission electron microscopy (TEM) and ATR-Fourier Transform Infrared spectroscopy (ATR-FTIR) confirmed wrapping of the SiO2 particles by the APTES-GO sheets. An impedimetric biosensor was constructed and used to sensitively detect Zika and dengue DNA and RNA via primer hybridization using different oligonucleotide sequences. The results demonstrate that the SiO2@APTES-GO electrode materials provide enhanced RNA detection sensitivity with selectivity and detection limit (1 femto-Molar), compared to both APTES-GO and APTES-SiO2. The three-dimensional structure, higher contact area, electrical properties and the ability for rapid hybridization offered by the SiO2@APTES-GO resulted in a successful design of a Zika and dengue biosensor with the lowest detection limit reported to date. We are in the process of developing a platform for multiple viral detection for point-of-care diagnostics for arthropode borne viral infectious diseases.

Surface functionalization of zirconium dioxide nano-adsorbents with 3-aminopropyl triethoxysilane and promoted adsorption activity for bovine serum albumin

Energy Technology Data Exchange (ETDEWEB)

Liu, Gen; Wu, Chaochao [Department of Chemistry, College of Sciences, Northeastern University, Shenyang 110819 (China); Zhang, Xia, E-mail: xzhang@mail.neu.edu.cn [Department of Chemistry, College of Sciences, Northeastern University, Shenyang 110819 (China); Liu, Yufeng, E-mail: liuyufeng@bjmu.edu.cn [College of Pharmacy, Liaoning University, Shenyang 110036 (China); Meng, Hao; Xu, Junli; Han, Yide; Xu, Xinxin; Xu, Yan [Department of Chemistry, College of Sciences, Northeastern University, Shenyang 110819 (China)

2016-06-15

Surface functionalization of zirconium dioxide (ZrO{sub 2}) nano-adsorbents was carried out by using 3-aminopropyl triethoxysilane (APTES) as the modifier. The addition amount of APTES was varied to determine the optimum modification extent, and the bulk ZrO{sub 2} microparticles were also modified by APTES for comparison. Some means, such as TEM, XRD, FT-IR, XPS and TG-DSC were used to character these ZrO{sub 2} particles. The results showed that the APTES molecules were chemically immobilized on the surface of ZrO{sub 2} nanoparticles via Zr−O−Si bonds, and the nano-ZrO{sub 2} samples showed larger special surface area. In the adsorption of bovine serum albumin (BSA), nano-ZrO{sub 2} samples exhibited enhanced adsorption activity, and APTES modified nano-ZrO{sub 2} with proper APTES content presented the best adsorption property. Under the same adsorption conditions, the equilibrium adsorption capacity of BSA on APTES-ZrO{sub 2}-2 was almost 2.3 times as that on pristine nano-ZrO{sub 2} and 3.0 times as on bulk ZrO{sub 2} microparticles. The increased adsorption capacity of APTES-ZrO{sub 2} nano-adsorbents can be attributed to the chemical interaction between amino and carboxyl groups at APTES-ZrO{sub 2}/BSA interface. The pH-dependent experiments showed that the optimum pH value for the adsorption and desorption was 5.0 and 9.0, respectively, which suggested that the adsorption and release of BSA could be controlled simply by adjusting the solution pH condition. - Highlights: • APTES chemically immobilized on ZrO{sub 2} nanoparticles via Zr−O−Si bond. • Enhanced adsorption capacity of BSA was observed on APTES-ZrO{sub 2}. • Chemical adsorption character of BSA on APTES-ZrO{sub 2}. • Adsorption/release of BSA on APTES-ZrO{sub 2} accomplished by adjusting pH value.

Amide proton transfer imaging to discriminate between low- and high-grade gliomas: added value to apparent diffusion coefficient and relative cerebral blood volume

Energy Technology Data Exchange (ETDEWEB)

Choi, Yoon Seong; Ahn, Sung Soo; Lee, Seung-Koo [Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, College of Medicine, Seoul (Korea, Republic of); Chang, Jong Hee; Kang, Seok-Gu [Yonsei University College of Medicine, Department of Neurosurgery, Seoul (Korea, Republic of); Kim, Se Hoon [Yonsei University College of Medicine, Department of Pathology, Seoul (Korea, Republic of); Zhou, Jinyuan [Johns Hopkins University School of Medicine, Division of MRI Research, Department of Radiology, Baltimore, MD (United States)

2017-08-15

To evaluate the added value of amide proton transfer (APT) imaging to the apparent diffusion coefficient (ADC) from diffusion tensor imaging (DTI) and the relative cerebral blood volume (rCBV) from perfusion magnetic resonance imaging (MRI) for discriminating between high- and low-grade gliomas. Forty-six consecutive adult patients with diffuse gliomas who underwent preoperative APT imaging, DTI and perfusion MRI were enrolled. APT signals were compared according to the World Health Organization grade. The diagnostic ability and added value of the APT signal to the ADC and rCBV for discriminating between low- and high-grade gliomas were evaluated using receiver operating characteristic (ROC) analyses and integrated discrimination improvement. The APT signal increased as the glioma grade increased. The discrimination abilities of the APT, ADC and rCBV values were not significantly different. Using both the APT signal and ADC significantly improved discrimination vs. the ADC alone (area under the ROC curve [AUC], 0.888 vs. 0.910; P = 0.007), whereas using both the APT signal and rCBV did not improve discrimination vs. the rCBV alone (AUC, 0.927 vs. 0.923; P = 0.222). APT imaging may be a useful imaging biomarker that adds value to the ADC for discriminating between low- and high-grade gliomas. (orig.)

Groundwater monitoring plan for the 300 Area process trenches

Energy Technology Data Exchange (ETDEWEB)

Lindberg, J.W.; Chou, C.J.; Johnson, V.G.

1995-05-23

This document describes the groundwater monitoring program for the Hanford Site 300 Area Process Trenches (300 APT). The 300 APT are a Resource Conservation and Recovery Act of 1976 (RCRA) regulated unit. The 300 APT are included in the Dangerous Waste Portion of the Resource Conservation and Recovery Act Permit for the Treatment, Storage, and Disposal of Dangerous Waste, Permit No. WA890008967, and are subject to final-status requirements for groundwater monitoring. This document describes a compliance monitoring program for groundwater in the uppermost aquifer system at the 300 APT. This plan describes the 300 APT monitoring network, constituent list, sampling schedule, statistical methods, and sampling and analysis protocols that will be employed for the 300 APT. This plan will be used to meet groundwater monitoring requirements from the time the 300 APT becomes part of the Permit and through the postclosure care period until certification of final closure.

Impedimetric Dengue Biosensor based on Functionalized Graphene Oxide Wrapped Silica Particles

International Nuclear Information System (INIS)

Jin, Seon-Ah; Poudyal, Shishir; Marinero, Ernesto E.; Kuhn, Richard J.; Stanciu, Lia A.

2016-01-01

Highlights: • 3D graphene oxide based material design. • Fabrication of a label-free dengue DNA and RNA impedimetric biosensor. • Design of a surface-based dengue sensor with good selectivity and detection limit. - Abstract: A composite of 3-Aminopropyltriethoxysilane (APTES) functionalized graphene oxide (APTES-GO) wrapped on SiO 2 particles (SiO 2 @APTES-GO) was prepared via self-assembly. Transmission electron microscopy (TEM) and ATR-Fourier Transform Infrared spectroscopy (ATR-FTIR) confirmed wrapping of the SiO 2 particles by the APTES-GO sheets. An impedimetric biosensor was constructed and used to sensitively detect dengue DNA and dengue RNA via primer hybridization using different oligonucleotide sequences. The results demonstrated that the SiO 2 @APTES-GO electrode material led to enhanced dengue RNA detection sensitivity with selectivity and detection limit (1 femto-Molar), compared to both APTES-GO and APTES-SiO 2 . The three-dimensional structure, higher contact area, electrical properties and the ability for rapid hybridization offered by the SiO 2 @APTES-GO led to the successful design of a dengue biosensor with the lowest detection limit reported to date.

Grading diffuse gliomas without intense contrast enhancement by amide proton transfer MR imaging: comparisons with diffusion- and perfusion-weighted imaging

Energy Technology Data Exchange (ETDEWEB)

Togao, Osamu; Hiwatashi, Akio; Yamashita, Koji; Kikuchi, Kazufumi; Honda, Hiroshi [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences, Fukuoka (Japan); Keupp, Jochen [Philips Research, Hamburg (Germany); Yoshimoto, Koji; Kuga, Daisuke; Iihara, Koji [Kyushu University, Department of Neurosurgery, Graduate School of Medical Sciences, Fukuoka (Japan); Yoneyama, Masami [Philips Electronics Japan, Tokyo (Japan); Suzuki, Satoshi O.; Iwaki, Toru [Kyushu University, Department of Neuropathology, Graduate School of Medical Sciences, Fukuoka (Japan); Takahashi, Masaya [Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX (United States)

2017-02-15

To investigate whether amide proton transfer (APT) MR imaging can differentiate high-grade gliomas (HGGs) from low-grade gliomas (LGGs) among gliomas without intense contrast enhancement (CE). This retrospective study evaluated 34 patients (22 males, 12 females; age 36.0 ± 11.3 years) including 20 with LGGs and 14 with HGGs, all scanned on a 3T MR scanner. Only tumours without intense CE were included. Two neuroradiologists independently performed histogram analyses to measure the 90th-percentile (APT{sub 90}) and mean (APT{sub mean}) of the tumours' APT signals. The apparent diffusion coefficient (ADC) and relative cerebral blood volume (rCBV) were also measured. The parameters were compared between the groups with Student's t-test. Diagnostic performance was evaluated with receiver operating characteristic (ROC) analysis. The APT{sub 90} (2.80 ± 0.59 % in LGGs, 3.72 ± 0.89 in HGGs, P = 0.001) and APT{sub mean} (1.87 ± 0.49 % in LGGs, 2.70 ± 0.58 in HGGs, P = 0.0001) were significantly larger in the HGGs compared to the LGGs. The ADC and rCBV values were not significantly different between the groups. Both the APT{sub 90} and APT{sub mean} showed medium diagnostic performance in this discrimination. APT imaging is useful in discriminating HGGs from LGGs among diffuse gliomas without intense CE. (orig.)

Anti-CEA aptamers labeled with 99mTc: encapsulation studies in long-circulating and pH-sensitive liposomes, biodistribution and imaging

International Nuclear Information System (INIS)

Leonel, M.F.V.; Andrade, A.S.R.; Oliveira, M.C.; Cardoso, V.N.; Barros, A.L.B.

2015-01-01

Colorectal cancer (CRC) is one of the leading cancers and the carcinoembryonic antigen (CEA) is a tumor marker widely used in diagnosis since it is overexpressed in tumor cells. Acid nucleic aptamers with high affinity and specificity for this antigen become promising molecules for CRC diagnosis by imaging. However, due to the action of nucleases in vivo, they have been investigated for association with liposomes, such as long-circulating and pH-sensitive liposomes (SPHL) that can be destabilized in the tumor region releasing aptamers and contributing to the CRC diagnosis by scintigraphy. In this work, SpHL containing DOPE, CHEMS and mPEG 2000 -DSPE were characterized by analyzing mean diameter, polydispersity index and zeta potential. The anti-CEA aptamers Apt3 and Apt3-Amino were labeled with technetium-99m and the encapsulation efficiency (EE) of 99m Tc-Apt3 in the SpHL by dehydration-rehydration (modified DRV) and freeze-thaw (FT) were analyzed, both in the presence of cryoprotectants. Biodistribution and scintigraphic images were performed at 1h and 4h post-injection of 99m Tc-Apt3-amino, 99m Tc-Apt3-SpHL or 99m Tc-Apt3-amino-SpHL complexes in Balb/c healthy mice. The SpHL dispersions were homogeneous. The radiolabeling yield with technetium-99m was over 90% for all complexes. By the dehydration-rehydration method, the SpHL increased over 200% after encapsulation procedure. By the freeze-thaw method, the SpHL size increased only 13.7%. Free 99m Tc-Apt3-amino showed to be cleared by renal via with high levels of radioactivity in the kidney and bladder, however, the 99m Tc-Apt3-SpHL and 99m Tc-Apt3-amino-SpHL clearly indicated high uptake by liver and spleen. The biodistribution of 99m Tc-Apt3-SpHL showed significant uptake of radioactivity by stomach and thyroid indicating less stability of the Apt3 radiolabelling in relation to Apt3-amino. (author)

Calibration of reconstruction parameters in atom probe tomography using a single crystallographic orientation

International Nuclear Information System (INIS)

Suram, Santosh K.; Rajan, Krishna

2013-01-01

The purpose of this work is to develop a methodology to estimate the APT reconstruction parameters when limited crystallographic information is available. Reliable spatial scaling of APT data currently requires identification of multiple crystallographic poles from the field desorption image for estimating the reconstruction parameters. This requirement limits the capacity of accurately reconstructing APT data for certain complex systems, such as highly alloyed systems and nanostructured materials wherein more than one pole is usually not observed within one grain. To overcome this limitation, we develop a quantitative methodology for calibrating the reconstruction parameters in an APT dataset by ensuring accurate inter-planar spacing and optimizing the curvature correction for the atomic planes corresponding to a single crystallographic orientation. We validate our approach on an aluminum dataset and further illustrate its capabilities by computing geometric reconstruction parameters for W and Al–Mg–Sc datasets. - Highlights: ► Quantitative approach is developed to accurately reconstruct APT data. ► Curvature of atomic planes in APT data is used to calibrate the reconstruction. ► APT reconstruction parameters are determined from a single crystallographic axis. ► Quantitative approach is demonstrated on W, Al and Al–Mg–Sc systems. ► Accurate APT reconstruction of complex materials is now possible

The mediating effects of childhood neglect on the association between schizotypal and autistic personality traits and depression in a non-clinical sample.

Science.gov (United States)

Liu, Jianbo; Gong, Jingbo; Nie, Guanghui; He, Yuqiong; Xiao, Bo; Shen, Yanmei; Luo, Xuerong

2017-10-25

Autistic personality traits (APT) and schizotypal personality traits (SPT) are associated with depression. However, mediating factors within these relationships have not yet been explored. Thus, the focus of the current study was to examine the effects of childhood neglect on the relationship between APT/SPT and depression. This cross-sectional study was conducted on first-year students (N = 2469) at Hunan University of Chinese Medicine and Hengyang Normal College (Changsha, China). Participants completed surveys on APT, SPT, childhood neglect, abuse and depression. Through correlational analyses, APT and SPT traits were positively correlated with childhood neglect and depression (p childhood maltreatment, emotional neglect (β = 0.112, p Childhood neglect did not account for the relationships between APT/SPT and depression. Further analysis found that childhood neglect mediated the relationship between SPT and depression but not APT and depression. Among types of childhood maltreatment, neglect was the strongest predicting factor for depression. Neglect did not account for the relationship between APT/SPT and depression but was a strong mediating factor between SPT and depression.

Outcome After Surgery for Acute Aortic Dissection

DEFF Research Database (Denmark)

Chemtob, Raphaelle Avigael; Møller-Sørensen, Hasse; Holmvang, Lene

2017-01-01

the use of antiplatelet therapy (APT) prior to AAD surgery and patient outcome, including indications according to the European Society of Cardiology's (ESC) recent guidelines. Design A retrospective, observational study. Setting A tertiary University Hospital, Rigshospitalet, Heart Centre, Copenhagen......, Denmark. Participants The study included 171 patients operated for AAD during 2010 to 2014. Interventions The independent relationship of preoperative APT was explored on 30-day mortality, intraoperative bleeding and perioperative transfusion requirements. Furthermore, the indications for APT were...... obtained. Measurements and Main Results Patients receiving APT (n = 73) did not have an increased 30-day mortality (29% v 20%, p = 0.18). However, APT increased intraoperative bleeding by 45% (p

Anti-CEA aptamers labeled with {sup 99m}Tc: encapsulation studies in long-circulating and pH-sensitive liposomes, biodistribution and imaging

Energy Technology Data Exchange (ETDEWEB)

Leonel, M.F.V.; Andrade, A.S.R. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Oliveira, M.C.; Cardoso, V.N.; Barros, A.L.B. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Faculdade de Farmacia

2015-07-01

Colorectal cancer (CRC) is one of the leading cancers and the carcinoembryonic antigen (CEA) is a tumor marker widely used in diagnosis since it is overexpressed in tumor cells. Acid nucleic aptamers with high affinity and specificity for this antigen become promising molecules for CRC diagnosis by imaging. However, due to the action of nucleases in vivo, they have been investigated for association with liposomes, such as long-circulating and pH-sensitive liposomes (SPHL) that can be destabilized in the tumor region releasing aptamers and contributing to the CRC diagnosis by scintigraphy. In this work, SpHL containing DOPE, CHEMS and mPEG{sub 2000}-DSPE were characterized by analyzing mean diameter, polydispersity index and zeta potential. The anti-CEA aptamers Apt3 and Apt3-Amino were labeled with technetium-99m and the encapsulation efficiency (EE) of {sup 99m}Tc-Apt3 in the SpHL by dehydration-rehydration (modified DRV) and freeze-thaw (FT) were analyzed, both in the presence of cryoprotectants. Biodistribution and scintigraphic images were performed at 1h and 4h post-injection of {sup 99m}Tc-Apt3-amino, {sup 99m}Tc-Apt3-SpHL or {sup 99m}Tc-Apt3-amino-SpHL complexes in Balb/c healthy mice. The SpHL dispersions were homogeneous. The radiolabeling yield with technetium-99m was over 90% for all complexes. By the dehydration-rehydration method, the SpHL increased over 200% after encapsulation procedure. By the freeze-thaw method, the SpHL size increased only 13.7%. Free {sup 99m}Tc-Apt3-amino showed to be cleared by renal via with high levels of radioactivity in the kidney and bladder, however, the {sup 99m}Tc-Apt3-SpHL and {sup 99m}Tc-Apt3-amino-SpHL clearly indicated high uptake by liver and spleen. The biodistribution of {sup 99m}Tc-Apt3-SpHL showed significant uptake of radioactivity by stomach and thyroid indicating less stability of the Apt3 radiolabelling in relation to Apt3-amino. (author)

Prior antiplatelet therapy and outcome following intracerebral hemorrhage: a systematic review

DEFF Research Database (Denmark)

Thompson, B B; Béjot, Y; Caso, V

2010-01-01

Antiplatelet therapy (APT) promotes bleeding; therefore, APT might worsen outcome in patients with intracerebral hemorrhage (ICH). We performed a systematic review and meta-analysis to address the hypothesis that pre-ICH APT use is associated with mortality and poor functional outcome following ICH....

Immunophenotyping of the cutaneous cellular infiltrate after atopy patch testing in cats with atopic dermatitis.

Science.gov (United States)

Roosje, P J; Thepen, T; Rutten, V P M G; van den Brom, W E; Bruijnzeel-Koomen, C A F M; Willemse, T

2004-10-01

Cats with spontaneously occurring atopic dermatitis have clinical and immunocytochemical characteristics compatible with these in humans with atopic dermatitis (AD). The atopy patch test (APT) has proven to be a valuable tool in elucidating the disease process in humans. Additionally, the APT is very specific and bypasses the problem of conflicting results due to differences in chronicity of lesions of AD patients. We adapted the APT for use in cats to explore the suitability of the APT as a tool to study the onset of allergic inflammation in cats with atopic dermatitis. APT were performed in AD cats (n = 6) and healthy cats (n = 10). All cats were patch tested with two allergens in three different dilutions and a diluent control. The allergens for the APT were selected from positive intradermal test and /or prick test results and consisted of: Dermatophagoides farinae, D. pteronyssinus, Tyrophagus putrescentiae, and a grass pollen mixture. APT were read after 10, 24 and 48 h, and punch biopsies for immunohistochemical evaluation were collected at these time points. Macroscopically positive APT reactions were observed in three out of six cats at 24 and/or 48 h with allergen concentrations of 25,000 and 100,000 NU/ml. Reactions were not observed at negative control sites and neither in control animals. A significantly increased number of IL-4+, CD4+, CD3+, MHC class II+ and CD1a+ cells was found in one AD cat with positive APT reactions. Five out of six AD cats had significantly increased IL-4+ T cell numbers at 24 and/or 48 h. Our data indicate that in cats, macroscopically positive patch test reactions can be induced, which have a cellular infiltrate similar to that in lesional skin. We found a high specificity and a macroscopically positive APT reaction in half of the cats, which is similar to what is seen in humans. Hence, the APT in cats might be a useful tool in studying the immunopathogenesis of feline atopic dermatitis.

The diagnostic accuracy of the atopy patch test in diagnosing hypersensitivity to cow's milk and hen's egg in unselected children with and without atopic dermatitis

DEFF Research Database (Denmark)

Osterballe, Morten; Andersen, Klaus E; Bindslev-Jensen, Carsten

2004-01-01

BACKGROUND: Previous studies have suggested that the atopy patch test (APT) may make oral challenge superfluous in diagnosing children with food hypersensitivity. OBJECTIVE: To investigate the clinical relevance of APT in predicting hypersensitivity to cow's milk and hen's egg in 486 unselected...... children 3 years of age. METHOD: The children were examined by APT, skin prick (SPT), histamine release (HR), and specific IgE followed by oral challenge when hypersensitivity to cow's milk or hen's egg was suspected. RESULTS: Food hypersensitivity confirmed by oral challenge was 1.6% to hen's egg and 0.......6% to cow's milk. No hypersensitivity to cow's milk or hen's egg was predicted by APT alone. CONCLUSION: APT could not predict food hypersensitivity not predicted by SPT, HR, or specific IgE. Thus, APT cannot be recommended in daily practice for the diagnosis of hypersensitivity to cow's milk and hen's egg...

Security Evaluation of the Cyber Networks under Advanced Persistent Threats

NARCIS (Netherlands)

Yang, L.; Li, Pengdeng; Yang, Xiaofan; Tang, Yuan Yan

2017-01-01

Advanced persistent threats (APTs) pose a grave threat to cyberspace, because they deactivate all the conventional cyber defense mechanisms. This paper addresses the issue of evaluating the security of the cyber networks under APTs. For this purpose, a dynamic model capturing the APT-based

Further evidence of close correspondence for alcohol demand decision making for hypothetical and incentivized rewards.

Science.gov (United States)

Amlung, Michael; MacKillop, James

2015-04-01

Alcohol purchase tasks (APTs) are increasingly being used to assess behavioral economic demand for alcohol. Prior studies utilizing APTs have typically assessed demand for hypothetical outcomes, making the extent to which these hypothetical measures reflect preferences when actual rewards are at stake an important empirical question. This study examined alcohol demand across hypothetical and incentivized APTs. Nineteen male heavy drinkers completed two APTs - one for hypothetical alcohol and another in which one randomly-selected outcome was provided. Participants were given an opportunity to consume the alcohol associated with their choice on the incentivized APT during a self-administration period in a simulated bar environment. Results indicated generally close correspondence between APT versions, though participants were more sensitive to increases in price and tended to consume more at low prices on the incentivized version. Estimated consumption on the incentivized APT was highly correlated with the amount of alcohol consumed in the laboratory (r=.87, pdecision-making when rewards are hypothetical vs. actually available. Implications for behavioral economic approaches to addictive behavior and directions for future research are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Construction of Index System Based on Advanced Persistent Threat

Directory of Open Access Journals (Sweden)

Lin Jia

2017-01-01

Full Text Available With the proliferation of advanced persistent threat (APT, APT attack effect evaluation is playing an increasingly important role in cyberspace. As one of the hot issues of network security, the evaluation to its attack effect can quantify the harm caused by APT. Then according to the evaluation results, we can derive specific measures to the network attack. At present, a lot of work has done in the network attack effect evaluation index system. However, a significant barrier to the development of APT attack effect evaluation is that the existing index system is either from the point of view of the network security situation, or for a single attack weapons to customize. In this paper, an evaluation index system is proposed through analysing the features of APT. Through this index system, we can not only quantify APT attack effect, but also visually observe the APT ability from various angles. Then, we use the analytic hierarchy process (AHP to model the evaluation process and calculate the weight of each indicator. Finally, the Ukrainian Power Outages is taken as an example to validate the proposed index system. The experimental results verify the effectiveness of the index system.

Aptamer-conjugated gold nanorod for photothermal ablation of epidermal growth factor receptor-overexpressed epithelial cancer

Science.gov (United States)

Choi, Jihye; Park, Yeonji; Choi, Eun Bi; Kim, Hyun-Ouk; Kim, Dong Joo; Hong, Yoochan; Ryu, Sung-Ho; Lee, Jung Hwan; Suh, Jin-Suck; Yang, Jaemoon; Huh, Yong-Min; Haam, Seungjoo

2014-05-01

Biomarker-specific photothermal nanoparticles that can efficiently sense markers that are overexpressed in distinguished adenocarcinomas have attracted much interest in an aspect of efficacy increase of cancer treatment. We demonstrated a promising prospect of a smart photothermal therapy agent employing anti-epidermal growth factor receptor aptamer (AptEGFR)-conjugated polyethylene glycol (PEG) layted gold nanorods (AptEGFR-PGNRs). The cetyltrimethylammonium bromide bilayer on GNRs was replaced with heterobifunctional PEG (COOH-PEG-SH) not only to serve as a biocompatible stabilizer and but also to conjugate Apt. Subsequently, to direct photothermal therapy agent toward epithelial cancer cells, the carboxylated PEGylated GNRs (PGNRs) were further functionalized with Apt using carbodiimide chemistry. Then, to assess the potential as biomarker-specific photothermal therapy agent of synthesized Apt-PGNRs, the optical properties, biocompatibility, colloidal stability, binding affinity, and epicellial cancer cell killing efficacy in vitro/in vivo under near-infrared laser irradiation were investigated. As a result, Apt-PGNRs exhibit excellent tumor targeting ability and feasibility of effective photothermal ablation cancer therapy.

Study on thermal, mechanical and adsorption properties of amine-functionalized MCM-41/PMMA and MCM-41/PS nanocomposites prepared by ultrasonic irradiation.

Science.gov (United States)

Mohammadnezhad, Gholamhossein; Abad, Saeed; Soltani, Roozbeh; Dinari, Mohammad

2017-11-01

In this study, two common industrial polymers, poly(methyl methacrylate) (PMMA) and polystyrene (PS), were incorporated into amine-functionalized MCM-41 mesoporous silica as reinforcement agents via an ultrasonic assisted method as a facile, fast, eco-friendly, and versatile synthetic tool. Amino functionalization of MCM-41 were performed by 3-aminopropyl triethoxysilane as a coupling agent and it is denoted as APTS-MCM-41. The obtained nanocomposites (NCs), APTS-MCM-41/PMMA and APTS-MCM-41/PS, were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning and transmission electron microscopies (SEM and TEM), and thermogravimetric analysis (TGA). Their mechanical properties were also probed via stress-strain curves and improved tensile properties were observed in the NCs relative to the neat polymers. Additionally, APTS-MCM-41/PMMA exhibited better mechanical properties than APTS-MCM-41/PS. Sorption studies were carried out on the two NCs and the effect of different process parameters, namely, pH, contact time, and initial Cd(II) concentration investigated in batch mode. Pseudo-second order and intraparticle diffusion models explain the Cd(II) kinetics more effectively for APTS-MCM-41/PMMA and APTS-MCM-41/PS, respectively. The adsorption isotherm data fitted well to Langmuir isotherm for both NCs and the maximum monolayer adsorption capacities were found to be 24.75mg/g and 10.42mg/g for APTS-MCM-41/PMMA and APTS-MCM-41/PS, respectively. The results demonstrate that the NCs show potential for use in adsorption of heavy metal ion such as Cd(II) from aqueous media. Copyright © 2017 Elsevier B.V. All rights reserved.

Epithelial cell adhesion molecule aptamer functionalized PLGA-lecithin-curcumin-PEG nanoparticles for targeted drug delivery to human colorectal adenocarcinoma cells

Science.gov (United States)

Li, Lei; Xiang, Dongxi; Shigdar, Sarah; Yang, Wenrong; Li, Qiong; Lin, Jia; Liu, Kexin; Duan, Wei

2014-01-01

To improve the efficacy of drug delivery, active targeted nanotechnology-based drug delivery systems are gaining considerable attention as they have the potential to reduce side effects, minimize toxicity, and improve efficacy of anticancer treatment. In this work CUR-NPs (curcumin-loaded lipid-polymer-lecithin hybrid nanoparticles) were synthesized and functionalized with ribonucleic acid (RNA) Aptamers (Apts) against epithelial cell adhesion molecule (EpCAM) for targeted delivery to colorectal adenocarcinoma cells. These CUR-encapsulated bioconjugates (Apt-CUR-NPs) were characterized for particle size, zeta potential, drug encapsulation, stability, and release. The in vitro specific cell binding, cellular uptake, and cytotoxicity of Apt-CUR-NPs were also studied. The Apt-CUR-NP bioconjugates exhibited increased binding to HT29 colon cancer cells and enhancement in cellular uptake when compared to CUR-NPs functionalized with a control Apt (P<0.01). Furthermore, a substantial improvement in cytotoxicity was achieved toward HT29 cells with Apt-CUR-NP bioconjugates. The encapsulation of CUR in Apt-CUR-NPs resulted in the increased bioavailability of delivered CUR over a period of 24 hours compared to that of free CUR in vivo. These results show that the EpCAM Apt-functionalized CUR-NPs enhance the targeting and drug delivery of CUR to colorectal cancer cells. Further development of CUR-encapsulated, nanosized carriers will lead to improved targeted delivery of novel chemotherapeutic agents to colorectal cancer cells. PMID:24591829

Is the Atopy Patch Test Reliable in the Evaluation of Food Allergy-Related Atopic Dermatitis?

Science.gov (United States)

Mansouri, Mahboubeh; Rafiee, Elham; Darougar, Sepideh; Mesdaghi, Mehrnaz; Chavoshzadeh, Zahra

2018-01-01

Aeroallergens and food allergens are found to be relevant in atopic dermatitis. The atopy patch test (APT) can help to detect food allergies in children with atopic dermatitis. This study evaluates if the APT is a valuable tool in the diagnostic workup of children with food allergy-related atopic dermatitis. 42 children between 6 months and 12 years of age were selected at the Mofid Children Hospital. Atopic dermatitis was diagnosed, and the severity of the disease was determined. At the test visit, the patients underwent a skin prick test (SPT), APT, and serum IgE level measurement for cow's milk, egg yolk, egg white, wheat, and soy. We found a sensitivity of 91.7%, a specificity of 72.7%, a positive predictive value (PPV) of 88%, a negative predictive value (NPV) of 80%, and an accuracy of 85.7% for APT performed for cow's milk. APT performed for egg yolk had a sensitivity and a NPV of 100%, while the same parameters obtained with egg white were 84.2 and 75%, respectively. The sensitivity, specificity, and NPV of the APT for wheat were 100, 75, and 100%, respectively. The sensitivity, PPV, and NPV of the APT for soy were 87.5, 70, and 87.5%, respectively. Our data demonstrate that the APT is a reliable diagnostic tool to evaluate suspected food allergy-related skin symptoms in childhood and infancy. © 2018 S. Karger AG, Basel.

Added value of amide proton transfer imaging to conventional and perfusion MR imaging for evaluating the treatment response of newly diagnosed glioblastoma

Energy Technology Data Exchange (ETDEWEB)

Park, Kye Jin; Kim, Ho Sung; Park, Ji Eun; Shim, Woo Hyun; Kim, Sang Joon [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Smith, Seth A. [Vanderbilt University Institute of Imaging Science, Vanderbilt University, Department of Radiology and Radiological Sciences, Nashville, TN (United States)

2016-12-15

To determine the added value of amide proton transfer (APT) imaging to conventional and perfusion MRI for differentiating tumour progression (TP) from the treatment-related effect (TE) in patients with post-treatment glioblastomas. Sixty-five consecutive patients with enlarging contrast-enhancing lesions following concurrent chemoradiotherapy were assessed using contrast-enhanced T1-weighted MRI (CE-T1WI), 90th percentile histogram parameters of normalized cerebral blood volume (nCBV90) and APT asymmetry value (APT90). Diagnostic performance was determined using the area under the receiver operating characteristic curve (AUC) and cross validations. There were statistically significant differences in the mean APT90 between the TP and the TE groups (3.87-4.01 % vs. 1.38-1.41 %; P <.001). Compared with CE-T1WI alone, the addition of APT90 to CE-T1WI significantly improved cross-validated AUC from 0.58-0.74 to 0.89-0.91 for differentiating TP from TE. The combination of CE-T1WI, nCBV90 and APT90 resulted in greater diagnostic accuracy for differentiating TP from TE than the combination of CE-T1WI and nCBV90 (cross-validated AUC, 0.95-0.97 vs. 0.84-0.91). The inter-reader agreement between the expert and trainee was excellent for the measurements of APT90 (intraclass correlation coefficient, 0.94). Adding APT imaging to conventional and perfusion MRI improves the diagnostic performance for differentiating TP from TE. (orig.)

The prevalence of positive reactions in the atopy patch test with aeroallergens and food allergens in subjects with atopic eczema: a European multicenter study.

Science.gov (United States)

Darsow, U; Laifaoui, J; Kerschenlohr, K; Wollenberg, A; Przybilla, B; Wüthrich, B; Borelli, S; Giusti, F; Seidenari, S; Drzimalla, K; Simon, D; Disch, R; Borelli, S; Devillers, A C A; Oranje, A P; De Raeve, L; Hachem, J-P; Dangoisse, C; Blondeel, A; Song, M; Breuer, K; Wulf, A; Werfel, T; Roul, S; Taieb, A; Bolhaar, S; Bruijnzeel-Koomen, C; Brönnimann, M; Braathen, L R; Didierlaurent, A; André, C; Ring, J

2004-12-01

The atopy patch test (APT) was proposed to evaluate IgE-mediated sensitizations in patients with atopic eczema (AE). The prevalence and agreement with clinical history and specific IgE (sIgE) of positive APT reactions was investigated in six European countries using a standardized method. A total of 314 patients with AE in remission were tested in 12 study centers on clinically uninvolved, non-abraded back skin with 200 index of reactivity (IR)/g of house dust mite Dermatophagoides pteronyssinus, cat dander, grass, and birch pollen allergen extracts with defined major allergen contents in petrolatum. Extracts of egg white, celery and wheat flour with defined protein content were also patch tested. APT values were evaluated at 24, 48, and 72 h according to the European Task Force on Atopic Dermatitis (ETFAD) guidelines. In addition, skin-prick test (SPT) and sIgE and a detailed history on allergen-induced eczema flares were obtained. Previous eczema flares, after contact with specific allergens, were reported in 1% (celery) to 34% (D. pteronyssinus) of patients. The frequency of clear-cut positive APT reactions ranged from 39% with D. pteronyssinus to 9% with celery. All ETFAD intensities occured after 48 and 72 h. Positive SPT (16-57%) and elevated sIgE (19-59%) results were more frequent. Clear-cut positive APT with all SPT and sIgE testing negative was seen in 7% of the patients, whereas a positive APT without SPT or sIgE for the respective allergen was seen in 17% of the patients. APT, SPT and sIgE results showed significant agreement with history for grass pollen and egg white (two-sided Pr > /Z/ atopic controls, no positive APT reaction was seen. Aeroallergens and food allergens are able to elicit eczematous skin reactions after epicutaneous application. As no gold standard for aeroallergen provocation in AE exists, the relevance of aeroallergens for AE flares may be evaluated by APT in addition to SPT and sIgE. The data may contribute to the international

Antiplatelet therapy at the time of coronary artery bypass grafting

DEFF Research Database (Denmark)

Kremke, Michael; Jensen, Mariann Tang; Bak, Mikkel

2013-01-01

OBJECTIVES: The purpose of this multicentre cohort study was to examine the relationship between antiplatelet therapy (APT) at the time of coronary artery bypass grafting (CABG) and postoperative bleeding complications, transfusion requirements and adverse cardiovascular events. METHODS: A matched...... Denmark Heart Registry. RESULTS: Of the 6350 patients enrolled, 1846 (29%) had been exposed to aspirin or clopidogrel within 5 days prior to CABG (the APT group). Matching with the remaining 4504 (71%) patients of the control group resulted in 1132 pairs of patients. Patients in the APT group had greater...... postoperative bleeding (OR: 2.08, 95% CI: 1.55-2.80). Overall, preoperative APT had no significant effect on postoperative 30-day mortality, incidence of myocardial infarction, stroke or need for dialysis. CONCLUSIONS: Preoperative APT is associated with increased bleeding and greater transfusion requirements...

Amine-functionalized, silver-exchanged zeolite NaY: Preparation, characterization and antibacterial activity

Energy Technology Data Exchange (ETDEWEB)

Hanim, Siti Aishah Mohd; Malek, Nik Ahmad Nizam Nik, E-mail: niknizam@fbb.utm.my; Ibrahim, Zaharah

2016-01-01

Graphical abstract: - Highlights: • Functionalization of Ag-exchanged zeolite NaY with 3-aminopropyltriethoxysilane APTES (ZSA) as antibacterial agent. • Antibacterial assay of ZSA was performed against Escherichia coli ATCC11229 and Staphylococcus aureus ATCC6538. • Functionalization of Ag-exchanged zeolite NaY with APTES significantly increased the antibacterial agent. • Different mechanisms of bacterial death were suggested for each bacteria type by the functionalized Ag-exchanged zeolite NaY. - Abstract: Amine-functionalized, silver-exchanged zeolite NaY (ZSA) were prepared with three different concentrations of 3-aminopropyltriethoxysilane (APTES) (0.01, 0.20 and 0.40 M) and four different concentrations of silver ions (25%, 50%, 100% and 200% from zeolite cation exchange capacity (CEC)). The samples were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX), surface area analysis, thermogravimetric analysis (TGA) and zeta potential (ZP) analysis. The FTIR results indicated that the zeolite was functionalized by APTES and that the intensity of the peaks corresponding to APTES increased as the concentration of APTES used was increased. The antibacterial activities of the silver-exchanged zeolite NaY (ZS) and ZSA were studied against Escherichia coli ATCC11229 and Staphylococcus aureus ATCC6538 using the disc diffusion technique (DDT) and minimum inhibitory concentration (MIC). The antibacterial activity of ZSA increased with the increase in APTES on ZS, and E. coli was more susceptible towards the sample compared to S. aureus. The FESEM micrographs of the bacteria after contact with the ZSA suggested different mechanisms of bacterial death for these two bacteria due to exposure to the studied sample. The functionalization of ZS with APTES improved the antibacterial activity of the silver-zeolite, depending on the concentration of silver

Aminopropyltriethoxysilane-mediated surface functionalization of hydroxyapatite nanoparticles: synthesis, characterization, and in vitro toxicity assay

Directory of Open Access Journals (Sweden)

Wang S

2011-12-01

Full Text Available Shige Wang1, Shihui Wen2, Mingwu Shen2, Rui Guo2, Xueyan Cao2, Jianhua Wang3, Xiangyang Shi1,2,41State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, 2College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, 3Department of Biochemistry and Molecular Cell Biology, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China; 4Centro de Química da Madeira, Universidade da Madeira, Campus da Penteada, Funchal, PortugalBackground: We report on aminopropyltriethoxysilane (APTS-mediated surface modification of nanohydroxyapatite with different surface functional groups for potential biomedical applications. In this study, nanohydroxyapatite covalently linked with APTS (n-HA-APTS was reacted with acetic anhydride or succinic anhydride to produce neutralized (n-HA-APTS.Ac or negatively charged (n-HA-APTS.SAH nanohydroxyapatite, respectively. Nanohydroxyapatite formed with amine, acetyl, and carboxyl groups was extensively characterized using Fourier transform infrared spectroscopy, transmission electron microscopy, 1H nuclear magnetic resonance spectroscopy, X-ray diffraction, inductively coupled plasma-atomic emission spectroscopy, and zeta potential measurements.Results: In vitro 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide colorimetric assay revealed that the slight toxicity of the amine-functionalized n-HA-APTS could be eliminated by post-functionalization of APTS amines to form acetyl and carboxyl groups. Blood compatibility assessment demonstrated that the negligible hemolytic activity of the pristine nanohydroxyapatite particles did not appreciably change after APTS-mediated surface functionalization.Conclusion: APTS-mediated functionalization of nanohydroxyapatite with different surface groups may be useful for further functionalization of nanohydroxyapatite with biologically active materials, thereby providing possibilities for a broad range of

Preparation and CO{sub 2} adsorption properties of aminopropyl-functionalized mesoporous silica microspheres

Energy Technology Data Exchange (ETDEWEB)

Araki, S.; Doi, H.; Sano, Y.; Tanaka, S.; Miyake, Y. [Hitachi Zosen Corp., Osaka (Japan). Technical Research Institute

2009-11-15

Aminopropyl-functionalized mesoporous silica microspheres (AF-MSM) were synthesized by a simple one-step modified Stober method. Dodecylamine (DDA) was used as the catalyst for the hydrolysis and condensation of the silica source and as the molecular template to prepare the ordered mesopores. The mesoporous silica surfaces were modified to aminopropyl groups by the co-condensation of tetraethoxysilane (TEOS) with 3-aminopropyltriethoxysilane (APTES), up to a maximum of 20 mol.% APTES content in the silica source. The particle size, Brunauer-Emmet-Teller (BET) specific surface area, and mesoporous regularity decreased with increasing APTES content. It is believed that this result is caused by a decreasing amount of DDA incorporated into AF-MSM with increasing APTES content. It was also confirmed that the spherical shape and the mesostructure were maintained even if 20 mol.% of APTES was added to the silica source. Moreover, AF-MSM was applied to the CO{sub 2} adsorbent. The breakthrough time of the CO{sub 2} and CO{sub 2} adsorption capacities increased with increasing APTES content. The adsorption capacity of CO{sub 2} for AF-MSM, prepared at 20 mol.% APTES, was 0.54 mmol g{sup -1}. Carbon dioxide adsorbed onto AF-MSM was completely desorbed by heating in a N{sub 2} purge at 423 K for 30 min.

Applying Amide Proton Transfer MR Imaging to Hybrid Brain PET/MR: Concordance with Gadolinium Enhancement and Added Value to [18F]FDG PET.

Science.gov (United States)

Sun, Hongzan; Xin, Jun; Zhou, Jinyuan; Lu, Zaiming; Guo, Qiyong

2018-06-01

The purpose of this study is to evaluate the diagnostic concordance and metric correlations of amide proton transfer (APT) imaging with gadolinium-enhanced magnetic resonance imaging (MRI) and 2-deoxy-2-[ 18 F-]fluoro-D-glucose ([ 18 F]FDG) positron emission tomography (PET), using hybrid brain PET/MRI. Twenty-one subjects underwent brain gadolinium-enhanced [ 18 F]FDG PET/MRI prospectively. Imaging accuracy was compared between unenhanced MRI, MRI with enhancement, APT-weighted (APTW) images, and PET based on six diagnostic criteria. Among tumors, the McNemar test was further used for concordance assessment between gadolinium-enhanced imaging, APT imaging, and [ 18 F]FDG PET. As well, the relation of metrics between APT imaging and PET was analyzed by the Pearson correlation analysis. APT imaging and gadolinium-enhanced MRI showed superior and similar diagnostic accuracy. APTW signal intensity and gadolinium enhancement were concordant in 19 tumors (100 %), while high [ 18 F]FDG avidity was shown in only 12 (63.2 %). For the metrics from APT imaging and PET, there was significant correlation for 13 hypermetabolic tumors (P PET in the evaluation of tumor metabolic activity during brain PET/MR studies.

APT target-blanket fabrication development

Energy Technology Data Exchange (ETDEWEB)

Fisher, D.L.

1997-06-13

Concepts for producing tritium in an accelerator were translated into hardware for engineering studies of tritium generation, heat transfer, and effects of proton-neutron flux on materials. Small-scale target- blanket assemblies were fabricated and material samples prepared for these performance tests. Blanket assemblies utilize composite aluminum-lead modules, the two primary materials of the blanket. Several approaches are being investigated to produce large-scale assemblies, developing fabrication and assembly methods for their commercial manufacture. Small-scale target-blanket assemblies, designed and fabricated at the Savannah River Site, were place in Los Alamos Neutron Science Center (LANSCE) for irradiation. They were subjected to neutron flux for nine months during 1996-97. Coincident with this test was the development of production methods for large- scale modules. Increasing module size presented challenges that required new methods to be developed for fabrication and assembly. After development, these methods were demonstrated by fabricating and assembling two production-scale modules.

An evaluation of the diagnostic value of different skin tests with egg in clinically egg-allergic children having atopic dermatitis

DEFF Research Database (Denmark)

Hansen, Tine K; Høst, Arne; Bindslev-Jensen, Carsten

2004-01-01

Skin testing is a common diagnostic procedure in food allergy, but the final diagnosis of food allergy is based on the clinical response to food challenge. We studied the value of the skin prick-prick test (SPT), skin application food test (SAFT) and atopy patch test (APT) with fresh egg extract......-allergic children were positive in SPT and 40-60% in APT. In APT and in SPT false-positive reactions to egg were observed. In this study comprising a small number of patients including control subjects, neither SAFT nor APT with fresh whole egg extract were able to increase the diagnostic accuracy in detecting egg...

Clinical performance of antibodies to prothrombin and thrombin in Chinese patients with antiphospholipid syndrome: potential interest in discriminating patients with thrombotic events and non-thrombotic events.

Science.gov (United States)

Zhang, Shulan; Wu, Ziyan; Li, Jing; Li, Ping; Chen, Si; Wen, Xiaoting; Li, Liubing; Zhang, Wen; Zhao, Jiuliang; Zhang, Fengchun; Li, Yongzhe

2017-04-01

A hallmark feature of antiphospholipid syndrome (APS) is the presence of a wide spectrum of antiphospholipid antibodies. In this study, we evaluated the clinical relevance of antibodies to prothrombin (PT) (aPT) and thrombin (aThr) in Chinese patients with APS. A total of 229 subjects were tested, including 86 patients with APS [35 patients with primary APS (PAPS), 51 patients with APS associated with other diseases (APSAOD)], 104 patients with non-APS diseases (disease controls), and 39 healthy controls. Serum IgG/IgM/IgA aPT and aThr were determined by ELISA. The levels of both IgG/IgM/IgA aPT and IgG/IgM/IgA aThr were significantly increased in patients with PAPS and APSAOD compared with patients with non-APS thrombosis and non-APS PRM, and HC. Both IgG aPT and IgG aThr exhibited promising diagnostic potentials for APS with sensitivities and specificities of 16.3 and 95.8% (IgG aPT), and 19.8 and 99.3% (IgG aThr), respectively. Importantly, both IgG aPT (OR 4.06; 95% CI 1.49-11.05) and IgG aThr (OR 4.49; 95% CI 1.62-12.45) were significantly correlated with arterial, but not venous, thrombotic events. Our findings highlighted that IgG aPT and IgG aThr could serve as promising biomarkers to identify patients at risk of arterial thrombosis in China.

Hybrid MR-PET of brain tumours using amino acid PET and chemical exchange saturation transfer MRI.

Science.gov (United States)

da Silva, N A; Lohmann, P; Fairney, J; Magill, A W; Oros Peusquens, A-M; Choi, C-H; Stirnberg, R; Stoffels, G; Galldiks, N; Golay, X; Langen, K-J; Jon Shah, N

2018-06-01

PET using radiolabelled amino acids has become a promising tool in the diagnostics of gliomas and brain metastasis. Current research is focused on the evaluation of amide proton transfer (APT) chemical exchange saturation transfer (CEST) MR imaging for brain tumour imaging. In this hybrid MR-PET study, brain tumours were compared using 3D data derived from APT-CEST MRI and amino acid PET using O-(2- 18 F-fluoroethyl)-L-tyrosine ( 18 F-FET). Eight patients with gliomas were investigated simultaneously with 18 F-FET PET and APT-CEST MRI using a 3-T MR-BrainPET scanner. CEST imaging was based on a steady-state approach using a B 1 average power of 1μT. B 0 field inhomogeneities were corrected a Prametric images of magnetisation transfer ratio asymmetry (MTR asym ) and differences to the extrapolated semi-solid magnetisation transfer reference method, APT# and nuclear Overhauser effect (NOE#), were calculated. Statistical analysis of the tumour-to-brain ratio of the CEST data was performed against PET data using the non-parametric Wilcoxon test. A tumour-to-brain ratio derived from APT# and 18 F-FET presented no significant differences, and no correlation was found between APT# and 18 F-FET PET data. The distance between local hot spot APT# and 18 F-FET were different (average 20 ± 13 mm, range 4-45 mm). For the first time, CEST images were compared with 18 F-FET in a simultaneous MR-PET measurement. Imaging findings derived from 18 F-FET PET and APT CEST MRI seem to provide different biological information. The validation of these imaging findings by histological confirmation is necessary, ideally using stereotactic biopsy.

A combination of positive dielectrophoresis driven on-line enrichment and aptamer-fluorescent silica nanoparticle label for rapid and sensitive detection of Staphylococcus aureus.

Science.gov (United States)

Shangguan, Jingfang; Li, Yuhong; He, Dinggeng; He, Xiaoxiao; Wang, Kemin; Zou, Zhen; Shi, Hui

2015-07-07

Staphylococcus aureus (S. aureus) is an important human pathogen that causes several diseases ranging from superficial skin infections to life-threatening diseases. Here, a method combining positive dielectrophoresis (pDEP) driven on-line enrichment and aptamer-fluorescent silica nanoparticle label has been developed for the rapid and sensitive detection of S. aureus in microfluidic channels. An aptamer, having high affinity to S. aureus, is used as the molecular recognition tool and immobilized onto chloropropyl functionalized fluorescent silica nanoparticles through a click chemistry approach to obtain S. aureus aptamer-nanoparticle bioconjugates (Apt(S.aureus)/FNPs). The pDEP driven on-line enrichment technology was used for accumulating the Apt(S.aureus)/FNP labeled S. aureus. After incubating with S. aureus, the mixture of Apt(S.aureus)/FNP labeled S. aureus and Apt(S.aureus)/FNPs was directly introduced into the pDEP-based microfluidic system. By applying an AC voltage in a pDEP frequency region, the Apt(S.aureus)/FNP labelled S. aureus moved to the electrodes and accumulated in the electrode gap, while the free Apt(S.aureus)/FNPs flowed away. The signal that came from the Apt(S.aureus)/FNP labelled S. aureus in the focused detection areas was then detected. Profiting from the specificity of aptamer, signal amplification of FNP label and pDEP on-line enrichment, this assay can detect as low as 93 and 270 cfu mL(-1)S. aureus in deionized water and spiked water samples, respectively, with higher sensitivities than our previously reported Apt(S.aureus)/FNP based flow cytometry. Moreover, without the need for separation and washing steps usually required for FNP label involved bioassays, the total assay time including sample pretreatment was within 2 h.

The Accurate Particle Tracer Code

OpenAIRE

Wang, Yulei; Liu, Jian; Qin, Hong; Yu, Zhi

2016-01-01

The Accurate Particle Tracer (APT) code is designed for large-scale particle simulations on dynamical systems. Based on a large variety of advanced geometric algorithms, APT possesses long-term numerical accuracy and stability, which are critical for solving multi-scale and non-linear problems. Under the well-designed integrated and modularized framework, APT serves as a universal platform for researchers from different fields, such as plasma physics, accelerator physics, space science, fusio...

Protocol for the establishment and operation of LTPP sections

CSIR Research Space (South Africa)

Jones, DJ

2004-03-01

Full Text Available and responsibilities • Site location and establishment • Data collection • Reporting criteria A set of data capture forms is provided. Keywords: Long term pavement performance, LTPP, APT, HVS Proposals for implementation: None... of pavement performance models used in pavement management systems. It is also recognized that the link between accelerated pavement testing (APT) and in- service pavement performance is through LTPP studies. While APT can, and does, provide significant...

Cancer cell-selective, clathrin-mediated endocytosis of aptamer decorated nanoparticles

Science.gov (United States)

Engelberg, Shira; Modrejewski, Julia; Walter, Johanna G.; Livney, Yoav D.; Assaraf, Yehuda G.

2018-01-01

Lung cancer is the leading cause of cancer mortality worldwide, resulting in 88% deaths of all diagnosed patients. Hence, novel therapeutic modalities are urgently needed. Single-stranded oligonucleotide-based aptamers (APTs) are excellent ligands for tumor cell targeting. However, the molecular mechanisms underlying their internalization into living cells have been poorly studied. Towards the application of APTs for active drug targeting to cancer cells, we herein studied the mechanism underlying S15-APT internalization into human non-small cell lung cancer A549 cells. We thus delineated the mode of entry of a model nanomedical system based on quantum dots (QDs) decorated with S15-APTs as a selective targeting moiety for uptake by A549 cells. These APT-decorated QDs displayed selective binding to, and internalization by target A549 cells, but not by normal human bronchial epithelial BEAS2B, cervical carcinoma (HeLa) and colon adenocarcinoma CaCo-2 cells, hence demonstrating high specificity. Flow cytometric analysis revealed a remarkably low dissociation constant of S15-APTs-decorated QDs to A549 cells (Kd = 13.1 ± 1.6 nM). Through the systematic application of a series of established inhibitors of known mechanisms of endocytosis, we show that the uptake of S15-APTs proceeds via a classical clathrin-dependent receptor-mediated endocytosis. This cancer cell-selective mode of entry could possibly be used in the future to evade plasma membrane-localized multidrug resistance efflux pumps, thereby overcoming an important mechanism of cancer multidrug resistance. PMID:29765515

Empirical evidence for stability of the 405-kiloyear Jupiter-Venus eccentricity cycle over hundreds of millions of years.

Science.gov (United States)

Kent, Dennis V; Olsen, Paul E; Rasmussen, Cornelia; Lepre, Christopher; Mundil, Roland; Irmis, Randall B; Gehrels, George E; Giesler, Dominique; Geissman, John W; Parker, William G

2018-06-12

The Newark-Hartford astrochronostratigraphic polarity timescale (APTS) was developed using a theoretically constant 405-kiloyear eccentricity cycle linked to gravitational interactions with Jupiter-Venus as a tuning target and provides a major timing calibration for about 30 million years of Late Triassic and earliest Jurassic time. While the 405-ky cycle is both unimodal and the most metronomic of the major orbital cycles thought to pace Earth's climate in numerical solutions, there has been little empirical confirmation of that behavior, especially back before the limits of orbital solutions at about 50 million years before present. Moreover, the APTS is anchored only at its younger end by U-Pb zircon dates at 201.6 million years before present and could even be missing a number of 405-ky cycles. To test the validity of the dangling APTS and orbital periodicities, we recovered a diagnostic magnetic polarity sequence in the volcaniclastic-bearing Chinle Formation in a scientific drill core from Petrified Forest National Park (Arizona) that provides an unambiguous correlation to the APTS. New high precision U-Pb detrital zircon dates from the core are indistinguishable from ages predicted by the APTS back to 215 million years before present. The agreement shows that the APTS is continuous and supports a stable 405-kiloyear cycle well beyond theoretical solutions. The validated Newark-Hartford APTS can be used as a robust framework to help differentiate provinciality from global temporal patterns in the ecological rise of early dinosaurs in the Late Triassic, amongst other problems.

Non-IgE-related diagnostic methods (LST, patch test).

Science.gov (United States)

Matsumoto, Kenji

2015-01-01

Although most food allergy patients have immediate-type reactions, some have delayed-type reactions. Unlike for the detection of food-specific IgE antibody in immediate-type (IgE-mediated) food allergies, only a few tests are currently available to aid in the diagnosis of delayed-type (non-IgE-mediated) food allergies. This chapter summarizes our current understanding of one in vitro test and one in vivo test for non-IgE-mediated food allergies: the lymphocyte stimulation test (LST) and the atopy patch test (APT). Although the LST is not yet standardized, a food protein-specific LST might be a useful tool for diagnosing delayed-type food allergies, and especially those manifesting with gastrointestinal symptoms but not skin symptoms. Various remaining issues - including basophil contamination of the peripheral blood mononuclear cell fraction and lipopolysaccharide contamination of food antigen preparations - are also discussed. The APT uses an epicutaneous patch technique to occlusively apply food antigens to the skin to induce inflammatory reactions at the patch application site. Because the APT shows modest sensitivity and specificity, the clinical benefit of the APT in the diagnosis of food allergies in patients with atopic dermatitis is limited. A position paper on the APT issued by the European Academy of Allergy and Clinical Immunology/Global Allergy and Asthma European Network in 2006 is briefly summarized, and several recent APT-related topics, including APT use for the diagnosis of food protein-induced enterocolitis syndrome, are discussed. © 2015 S. Karger AG, Basel.

Amide proton transfer imaging in clinics: Basic concepts and current and future use in brain tumors and stoke

Energy Technology Data Exchange (ETDEWEB)

Park, Ji Eun [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Jahng, Geon Ho [Dept. of Radiology, Kyung Hee University Hospital at Gangdong, College of Medicine, Kyung Hee University, Seoul (Korea, Republic of); Jeong, Ha Kyu [Philips Korea, Seoul (Korea, Republic of)

2016-12-15

Amide proton transfer (APT) imaging is gaining attention as a relatively new in vivo molecular imaging technique that has higher sensitivity and spatial resolution than magnetic resonance spectroscopy imaging. APT imaging is a subset of the chemical exchange saturation transfer mechanism, which can offer unique image contrast by selectively saturating protons in target molecules that get exchanged with protons in bulk water. In this review, we describe the basic concepts of APT imaging, particularly with regard to the benefit in clinics from the current literature. Clinical applications of APT imaging are described from two perspectives: in the diagnosis and monitoring of the treatment response in brain glioma by reflecting endogenous mobile proteins and peptides, and in the potential for stroke imaging with respect to tissue acidity.

Cine club

CERN Multimedia

Cine club

2017-01-01

Wednesday 18 January 2017 at 20:00 CERN Council Chamber 35 Up Directed by Michael Apted UK, 1991, 123 minutes Director Michael Apted revisits the same group of British-born adults after a seven-year wait. The subjects are interviewed as to the changes that have occurred in their lives during the last seven years. Original version English; French subtitles Wednesday 25 January 2017 at 20:00 CERN Council Chamber 56 Up Directed by Michael Apted, Paul Almond UK, 2012, 144 minutes Director Michael Apted revisits the same group of British-born adults after a seven-year wait. The subjects are interviewed as to the changes that have occurred in their lives during the last seven years. Original version English; French subtitles Save

Economics of All-Polyethylene Versus Metal-Backed Tibial Prosthesis Designs.

Science.gov (United States)

Chambers, Monique C; El-Othmani, Mouhanad M; Sayeed, Zain; Anoushiravani, Afshin; Schnur, Anne-Kathrin; Mihalko, William M; Saleh, Khaled J

2016-05-01

With the large number of total knee arthroplasties being performed and expectations that these numbers will be on the rise over the coming decades, efforts to provide cost-efficient care are of greater interest. The preferred design of knee arthroplasty implants has changed over time, with the original all-polyethylene tibial (APT) design being replaced by metal-backed tibial (MBT) components, as well as more recent considerations of newer APT designs. Modern APT components have been shown to have similar or superior outcomes than MBT components. Despite their limitations, APT components can be used to reduce the economic burden to the provider, medical institution, and health care system as a whole. There is a paucity of evidence-based literature directly comparing the cost associated with APT and MBT components. The purpose of this report is to review the literature to assess the available data regarding direct and indirect costs of both designs so that orthopedic surgeons can account for economic differences in everyday practice. [Orthopedics. 2016; 39(3):S61-S66.]. Copyright 2016, SLACK Incorporated.

Promotion of tribological and hydrophobic properties of a coating on TPE substrates by atmospheric plasma-polymerization

Science.gov (United States)

Sainz-García, Elisa; Alba-Elías, Fernando; Múgica-Vidal, Rodolfo; Pantoja-Ruiz, Mariola

2016-05-01

Thermoplastic elastomers (TPE) are used in the automotive sealing industry with the objective of producing anti-friction and hydrophobic components. At present, the anti-friction property is achieved by the electrostatic flocking, which sometimes produces an irregular coating. Therefore, this paper's objective is the promotion of adhesion of an anti-friction (based on the silane aminopropyltriethoxysilane-APTES-) and hydrophobic (based on the fluorinated precursor 1-perfluorohexene-PFH-) coating by the adhesion promoter, APTES. Different mixtures of APTES and PFH have been applied to a TPE substrate by an Atmospheric Pressure Plasma Jet (APPJ) system with Dielectric Barrier Discharge (DBD) in order to determine the optimal mixture of precursors. The main difficulty in this work lies in the hydrophilic character of APTES and the low adhesion of the fluorinated coatings. The sample coated with a mixture of 50% APTES and 50% PFH (A50P50) was found to be the best one to satisfy both properties at the same time, despite not having the highest dynamic water contact angle (WCA) or the lowest friction coefficient.

300 Area Process Trenches Modified Closure/Postclosure Plan

International Nuclear Information System (INIS)

1997-09-01

This chapter provides a brief summary of the contents of each chapter of this plan for the closure of the 300 Area Process Trenches (300 APT) treatment, storage, and/or disposal unit. It also provides background information for this unit and discusses how its closure will be integrated with the remedial action for the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 300- FF-1 Operable Unit. The 300 APT is located within the 300 Area of the Hanford Site. This area contained reactor fuel fabrication facilities and research and development laboratories. The 300 APT was constructed and began operations in 1975 as the 316-5 Process Trenches. Effluent was discharged to the trenches by way of the 300 Area process sewer system, which has been the sole source of effluent for the 300 APT. The 316-5 Process Trenches gained Resource Conservation and Recovery Act of 1976 (RCRA) interim status as the 300 APT TSD unit on November 11, 1985. The unit has been administratively closed to discharges of dangerous waste since 1985

MLDS: Multi-Layer Defense System for Preventing Advanced Persistent Threats

Directory of Open Access Journals (Sweden)

Daesung Moon

2014-12-01

Full Text Available Here we report on the issue of Advanced Persistent Threats (APT, which use malware for the purpose of leaking the data of large corporations and government agencies. APT attacks target systems continuously by utilizing intelligent and complex technologies. To overthrow the elaborate security network of target systems, it conducts an attack after undergoing a pre-reconnaissance phase. An APT attack causes financial loss, information leakage, etc. They can easily bypass the antivirus system of a target system. In this paper, we propose a Multi-Layer Defense System (MLDS that can defend against APT. This system applies a reinforced defense system by collecting and analyzing log information and various information from devices, by installing the agent on the network appliance, server and end-user. It also discusses how to detect an APT attack when one cannot block the initial intrusion while continuing to conduct other activities. Thus, this system is able to minimize the possibility of initial intrusion and damages of the system by promptly responding through rapid detection of an attack when the target system is attacked.

Amide proton transfer imaging for differentiation of benign and atypical meningiomas

Energy Technology Data Exchange (ETDEWEB)

Joo, Bio [The Armed Forces Capital Hospital, Department of Radiology, Seongnam, Gyeonggi-do (Korea, Republic of); Han, Kyunghwa; Choi, Yoon Seong; Lee, Seung-Koo [Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, College of Medicine, Seoul (Korea, Republic of); Ahn, Sung Soo [Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, College of Medicine, Seoul (Korea, Republic of); Yonsei University, Department of Radiology, College of Medicine, Seoul (Korea, Republic of); Chang, Jong Hee; Kang, Seok-Gu [Yonsei University College of Medicine, Department of Neurosurgery, Seoul (Korea, Republic of); Kim, Se Hoon [Yonsei University College of Medicine, Department of Pathology, Seoul (Korea, Republic of); Zhou, Jinyuan [Johns Hopkins University School of Medicine, Division of MRI Research, Department of Radiology, Baltimore, MD (United States)

2018-01-15

To investigate the difference in amide proton transfer (APT)-weighted signals between benign and atypical meningiomas and determine the value of APT imaging for differentiating the two. Fifty-seven patients with pathologically diagnosed meningiomas (benign, 44; atypical, 13), who underwent preoperative MRI with APT imaging between December 2014 and August 2016 were included. We compared normalised magnetisation transfer ratio asymmetry (nMTR{sub asym}) values between benign and atypical meningiomas on APT-weighted images. Conventional MRI features were qualitatively assessed. Both imaging features were evaluated by multivariable logistic regression analysis. The discriminative value of MRI with and without nMTR{sub asym} was evaluated. The nMTR{sub asym} of atypical meningiomas was significantly greater than that of benign meningiomas (2.46% vs. 1.67%; P < 0.001). In conventional MR images, benign and atypical meningiomas exhibited significant differences in maximum tumour diameter, non-skull base location, and heterogeneous enhancement. On multivariable logistic regression analysis, high nMTR{sub asym} was an independent predictor of atypical meningiomas (adjusted OR, 11.227; P = 0.014). The diagnostic performance of MRI improved with nMTR{sub asym} for predicting atypical meningiomas. Atypical meningiomas exhibited significantly higher APT-weighted signal intensities than benign meningiomas. The discriminative value of conventional MRI improved significantly when combined with APT imaging for diagnosis of atypical meningioma. (orig.)

Comparison of intraocular pressure measured by non-contact air puff versus Goldmann applanation tonometers in gas-filled vitrectomized eyes.

Science.gov (United States)

Patikulsila, Direk; Taweemankongsab, Srisuda; Ngamtipakorn, Supob

2003-05-01

To compare intraocular pressure (IOP) measured by two different instruments, air puff tonometer (APT) versus Goldmann applanation tonometer (GAT), in gas-filled vitrectomized eyes. Three-month, prospective, comparative trial. Thirty-eight patients (38 eyes), who underwent a pars plana vitrectomy (PPV) with gas injection, were enrolled in the study. The IOP was measured by an APT, followed by GAT within 10 minutes by two different, masked investigators. IOPs were measured by two methods and then were compared. Overall, there was a high correlation between both measurements (r = 0.908, p 0.05). By a subgroup analysis of 17 eyes with IOP measured by a GAT of 21 mmHg or less, the APT readings (15.28 +/- 4.81) and GAT readings (14.47 +/- 3.89) were not significantly different (p > 0.05). Of 21 eyes, with IOP measured by a GAT of 22 mmHg or more, the APT readings (26.88 +/- 8.81) were significantly lower than those obtained by the GAT (29.62 +/- 7.69) (p < 0.05). In gas-filled vitrectomized eyes, IOP measurements obtained by an APT correlated well with those obtained by GAT, especially when the IOP was within normal range. However, in eyes with elevated IOP, the APT significantly underestimated the IOP measurement when compared to the gold standard, GAT.

Surface functionalization of magnetite nanoparticle: A new approach using condensation of alkoxysilanes

Science.gov (United States)

Rodriguez, A. F. R.; Costa, T. P.; Bini, R. A.; Faria, F. S. E. D. V.; Azevedo, R. B.; Jafelicci, M.; Coaquira, J. A. H.; Martínez, M. A. R.; Mantilla, J. C.; Marques, R. F. C.; Morais, P. C.

2017-09-01

In this study we report on successful production of two samples (BR15 and BR16) comprising magnetite (Fe3O4) nanoparticles ( 10 nm) surface-functionalized via hydrolysis and condensation of alkoxysilane agents, namely 3-aminopropyl-trimethoxisilane (APTS) and N-propyl-trimethoxisilane (NPTS). The as-produced samples were characterized using transmission electron microscopy (TEM), x-ray diffraction (XRD), magnetization measurements (5 K and 300 K hysteresis cycles and zero field-cooled/field-cooled measurements), and Mössbauer spectroscopy (77 and 297 K). The Mössbauer data supported the model picture of a core-shell magnetite-based system. This material system shows shell properties influenced by the surface-coating design, either APTS-coated (BR15) or APTS+NPTS-coated (sample BR16). Analyses of the Mössbauer spectra indicates that the APTS-coated sample presents Fe(III)-rich core and Fe(II)-rich shell with strong hyperfine field; whereas, the APTS+NPTS-coated sample leads to a mixture of two main nanostructures, one essentially surface-terminated with APTS whereas the other surface-terminated with NPTS, both presenting weak hyperfine fields compared with the single surface-coated sample. Magnetization measurements support the core-shell picture built from the analyses of the Mössbauer data. Our findings emphasize the capability of the Mössbauer spectroscopy in assessing subtle differences in surface-functionalized iron-based core-shell nanostructures.

Role of atopy patch test for diagnosis of food allergy-related gastrointestinal symptoms in children.

Science.gov (United States)

Boonyaviwat, Onsuree; Pacharn, Punchama; Jirapongsananuruk, Orathai; Vichyanond, Pakit; Visitsunthorn, Nualanong

2015-12-01

Double-blind, placebo-controlled food challenge is the gold standard for diagnosing food allergy. However, it is a time-consuming procedure and requires onsite medical supervision and resuscitating medicines and devices on hand. The objective of this study was to compare the atopy patch test (APT) with the oral food challenge test (OFC) in children with suspected food allergy-related gastrointestinal (GI) symptoms. A prospective self-controlled study enrolled children with a history of suspected food allergy-related GI symptoms. Skin prick test (SPT) and APT using lyophilized and commercial allergen extracts for cow's milk, egg, wheat, soy, and shrimp were evaluated, and OFC was performed. Thirty-nine patients (25 boys, median age 2.4 yrs) with 76 events of suspected food allergy-related GI symptoms were enrolled. SPT was positive in 11/76 events (14.5%). Sensitivity, specificity, predictive values, and likelihood ratio were calculated related to the food challenge outcome. Of 41 OFC, 30 (73.2%) were positive. APT using lyophilized allergen extracts yielded high sensitivity (80%) and high positive predictive value (85.7%). APT using commercial allergen extracts yielded low sensitivity (30%) but high specificity (90%). The negative predictive value of APT using lyophilized and commercial allergen extracts was 53.8% and 32.2%, respectively. All cases with positive APT using lyophilized allergen extracts together with positive SPT also had positive OFC. In contrast to commercial extracts, APT with lyophilized allergen extracts is reliable, safe, and maybe useful for the diagnosis of suspected food allergy-related GI symptoms in children. OFC is still needed in most of the cases. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

DETERMINATION OF AGRICULTURAL POTENTIAL BY GEO SPATIAL MODELING AND MULTI CRITERIA ANALYSIS FOR “BALSAS MEZCALA” WATERSHED

Directory of Open Access Journals (Sweden)

Anastacio Espejel-García

2015-07-01

Full Text Available The use of geographic information systems (GIS facilitates the modeling of specific information allowing faster, lower costs and accuracy for the planning of the agricultural activities for large territories. The objective for this paper was to use GIS as a support for the approach of the land use potential for the “Balsas Mezcala” watershed; for this purpose the multi criteria analysis was used, that allows to consider decision make issues with multiples objectives and considering the following criteria: geo-pedological (geomorphology and soil, climatology (thermal models and rainfall and the edapho-climatological requirements of the crops, the “Balsas Mezcala” hydrological region was chosen as the study area; through cartographic material the area was delimited and climate information was obtained from weather stations, geographic information and the data bases was collected from many different government agencies (INEGI, SEMARNAT, CONABIO, CONAGUA, IMTA, such information was processed in the ArcGIS software version 10.2.2, to obtained the geodatabases and geo spatial matrix which served as a cartographic input for the multi criteria analysis. The result of this investigation is a system that from geo spatial matrix and vectorial data originates raster dataset, same that were submitted to a modeling process with geo statistical algorithms, with that from a structure language, identify the potential zones with the highest aptness level, through the variable attributes that assign a weighted value using the methodology proposed by the United States Department of Agriculture (USDA in 1971 and taken by Food and Agriculture Organization of the United Nations (FAO for case studies since 1977 as an Agro-ecological Zoning System (AEZ. The result of the modeling of the soil aptness level in the watershed are 4 classes with 6 levels of aptness (very apt, apt, moderately apt, little apt, very little apt, unapt: Lands with irrigation potential

Acid-catalyzed reductive amination of aldoses with 8-aminopyrene-1,3,6-trisulfonate.

Science.gov (United States)

Evangelista, R A; Guttman, A; Chen, F T

1996-02-01

The reductive amination of monosaccharides with 8-aminopyrene-1,3,6-trisulfonate (APTS) in seven different organic acids including the commonly used acetic acid was investigated by capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection. The correlation between the yields of the saccharide-APTS adducts and pKa of the organic acid catalyst is consistent with general acid catalysis of the rate-determining step of the reductive amination reaction. Derivatization in the presence of organic acids of higher strength than acetic acid produced substantially higher yields of APTS-sugar adducts, an effect which is more pronounced for N-acetylamino sugars. Optimum yields were obtained using citric acid as a catalyst. Conversion of a few nanomoles of neutral saccharides to the APTS derivatives is achieved at 75 degrees C in less than 60 min.

Performance assessment of two whole-lake acoustic positional telemetry systems - is reality mining of free-ranging aquatic animals technologically possible?

DEFF Research Database (Denmark)

Baktoft, Henrik; Zajicek, Petr; Klefoth, Thomas

2015-01-01

Acoustic positional telemetry systems (APTs) represent a novel approach to study the behaviour of free ranging aquatic animals in the wild at unprecedented detail. System manufactures promise remarkably high temporal and spatial resolution. However, the performance of APTs has rarely been...... rigorously tested at the level of entire ecosystems. Moreover, the effect of habitat structure on system performance has only been poorly documented. Two APTs were deployed to cover two small lakes and a series of standardized stationary tests were conducted to assess system performance. Furthermore...... for stationary transmitters due to accumulation of small tracking errors, moving transmitters can result in both over-and underestimation of distances depending on circumstances. Both deployed APTs were capable of providing high resolution positional data at the scale of entire lakes and are suitable systems...

Amine-modified magnetic iron oxide nanoparticle as a promising carrier for application in bio self-healing concrete.

Science.gov (United States)

Seifan, Mostafa; Ebrahiminezhad, Alireza; Ghasemi, Younes; Samani, Ali Khajeh; Berenjian, Aydin

2018-01-01

Self-healing mechanisms are a promising solution to address the concrete cracking issue. Among the investigated self-healing strategies, the biotechnological approach is distinguished itself by inducing the most compatible material with concrete composition. In this method, the potent bacteria and nutrients are incorporated into the concrete matrix. Once cracking occurs, the bacteria will be activated, and the induced CaCO 3 crystals will seal the concrete cracks. However, the effectiveness of a bio self-healing concrete strictly depends on the viability of bacteria. Therefore, it is required to protect the bacteria from the resulted shear forces caused by mixing and drying shrinkage of concrete. Due to the positive effects on mechanical properties and the high compatibility of metallic nanoparticles with concrete composition, for the first time, we propose 3-aminopropyltriethoxy silane-coated iron oxide nanoparticles (APTES-coated IONs) as a biocompatible carrier for Bacillus species. This study was aimed to investigate the effect of APTES-coated IONs on the bacterial viability and CaCO 3 yield for future application in the concrete structures. The APTES-coated IONs were successfully synthesized and characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results show that the presence of 100 μg/mL APTES-coated IONs could increase the bacterial viability. It was also found that the CaCO 3 -specific yield was significantly affected in the presence of APTES-coated IONs. The highest CaCO 3 -specific yield was achieved when the cells were decorated with 50 μg/mL of APTES-coated IONs. This study provides new insights for the application of APTES-coated IONs in designing bio self-healing strategies.

Adaptive pacing, cognitive behaviour therapy, graded exercise, and specialist medical care for chronic fatigue syndrome: a cost-effectiveness analysis.

Directory of Open Access Journals (Sweden)

Paul McCrone

Full Text Available The PACE trial compared the effectiveness of adding adaptive pacing therapy (APT, cognitive behaviour therapy (CBT, or graded exercise therapy (GET, to specialist medical care (SMC for patients with chronic fatigue syndrome. This paper reports the relative cost-effectiveness of these treatments in terms of quality adjusted life years (QALYs and improvements in fatigue and physical function.Resource use was measured and costs calculated. Healthcare and societal costs (healthcare plus lost production and unpaid informal care were combined with QALYs gained, and changes in fatigue and disability; incremental cost-effectiveness ratios (ICERs were computed.SMC patients had significantly lower healthcare costs than those receiving APT, CBT and GET. If society is willing to value a QALY at £30,000 there is a 62.7% likelihood that CBT is the most cost-effective therapy, a 26.8% likelihood that GET is most cost effective, 2.6% that APT is most cost-effective and 7.9% that SMC alone is most cost-effective. Compared to SMC alone, the incremental healthcare cost per QALY was £18,374 for CBT, £23,615 for GET and £55,235 for APT. From a societal perspective CBT has a 59.5% likelihood of being the most cost-effective, GET 34.8%, APT 0.2% and SMC alone 5.5%. CBT and GET dominated SMC, while APT had a cost per QALY of £127,047. ICERs using reductions in fatigue and disability as outcomes largely mirrored these findings.Comparing the four treatments using a health care perspective, CBT had the greatest probability of being the most cost-effective followed by GET. APT had a lower probability of being the most cost-effective option than SMC alone. The relative cost-effectiveness was even greater from a societal perspective as additional cost savings due to reduced need for informal care were likely.

Validity of the alcohol purchase task: a meta-analysis.

Science.gov (United States)

Kiselica, Andrew M; Webber, Troy A; Bornovalova, Marina A

2016-05-01

Behavioral economists assess alcohol consumption as a function of unit price. This method allows construction of demand curves and demand indices, which are thought to provide precise numerical estimates of risk for alcohol problems. One of the more commonly used behavioral economic measures is the Alcohol Purchase Task (APT). Although the APT has shown promise as a measure of risk for alcohol problems, the construct validity and incremental utility of the APT remain unclear. This paper presents a meta-analysis of the APT literature. Sixteen studies were included in the meta-analysis. Studies were gathered via searches of the PsycInfo, PubMed, Web of Science and EconLit research databases. Random-effects meta-analyses with inverse variance weighting were used to calculate summary effect sizes for each demand index-drinking outcome relationship. Moderation of these effects by drinking status (regular versus heavy drinkers) was examined. Additionally, tests of the incremental utility of the APT indices in predicting drinking problems above and beyond measuring alcohol consumption were performed. The APT indices were correlated in the expected directions with drinking outcomes, although many effects were small in size. These effects were typically not moderated by the drinking status of the samples. Additionally, the intensity metric demonstrated incremental utility in predicting alcohol use disorder symptoms beyond measuring drinking. The Alcohol Purchase Task appears to have good construct validity, but limited incremental utility in estimating risk for alcohol problems. © 2015 Society for the Study of Addiction.

Atom probe tomography simulations and density functional theory calculations of bonding energies in Cu3Au

KAUST Repository

Boll, Torben; Zhu, Zhiyong; Al-Kassab, Talaat; Schwingenschlö gl, Udo

2012-01-01

In this article the Cu-Au binding energy in Cu3Au is determined by comparing experimental atom probe tomography (APT) results to simulations. The resulting bonding energy is supported by density functional theory calculations. The APT simulations

Physicochemical characteristics and sorption capacities of heavy metal ions of activated carbons derived by activation with different alkyl phosphate triesters

Science.gov (United States)

Wang, Jing; Liu, Hai; Yang, Shaokun; Zhang, Jian; Zhang, Chenglu; Wu, Haiming

2014-10-01

Five alkyl phosphate triesters (APTEs), including trimethyl phosphate (TMP), triethyl phosphate (TEP), triisopropyl phosphate (TPP), tributyl phosphate (TBP) and trioctyl phosphate (TOP), were used as activating agents for preparing activated carbons (AC-APTEs) with high surface acidity and metal ion sorption capacity. N2 adsorption/desorption isotherms, surface morphologies, elemental compositions, results of Boehm's titration and sorption capacities of heavy metal ions of the carbons were investigated. AC-APTEs contained much more acidic groups and exhibited much less surface area (phosphoric acid activation. For the AC-APTEs, AC-TOP had the highest surface area (488 m2/g), AC-TMP showed the highest yield (41.1%), and AC-TBP possessed the highest acidic groups (2.695 mmol/g), oxygen content (47.0%) and metal ion sorption capacities (40.1 mg/g for Ni(II) and 53.5 mg/g for Cd(II)). For the carbons, AC-APTEs showed much larger Ni(II) and Cd(II) sorption capacities than AC-PPA, except AC-TPP. The differences of the carbons in the physicochemical and sorption properties suggested surface chemistry of the carbons was the main factor influencing their sorption capacities whereas the pore structure played a secondary role.

Carrier collection losses in interface passivated amorphous silicon thin-film solar cells

International Nuclear Information System (INIS)

Neumüller, A.; Sergeev, O.; Vehse, M.; Agert, C.; Bereznev, S.; Volobujeva, O.; Ewert, M.; Falta, J.

2016-01-01

In silicon thin-film solar cells the interface between the i- and p-layer is the most critical. In the case of back diffusion of photogenerated minority carriers to the i/p-interface, recombination occurs mainly on the defect states at the interface. To suppress this effect and to reduce recombination losses, hydrogen plasma treatment (HPT) is usually applied. As an alternative to using state of the art HPT we apply an argon plasma treatment (APT) before the p-layer deposition in n-i-p solar cells. To study the effect of APT, several investigations were applied to compare the results with HPT and no plasma treatment at the interface. Carrier collection losses in resulting solar cells were examined with spectral response measurements with and without bias voltage. To investigate single layers, surface photovoltage and X-ray photoelectron spectroscopy (XPS) measurements were conducted. The results with APT at the i/p-interface show a beneficial contribution to the carrier collection compared with HPT and no plasma treatment. Therefore, it can be concluded that APT reduces the recombination centers at the interface. Further, we demonstrate that carrier collection losses of thin-film solar cells are significantly lower with APT.

Carrier collection losses in interface passivated amorphous silicon thin-film solar cells

Energy Technology Data Exchange (ETDEWEB)

Neumüller, A., E-mail: alex.neumueller@next-energy.de; Sergeev, O.; Vehse, M.; Agert, C. [NEXT ENERGY EWE Research Centre for Energy Technology at the University of Oldenburg, Carl-von-Ossietzky-Straße 15, 26129 Oldenburg (Germany); Bereznev, S.; Volobujeva, O. [Department of Materials Science, Tallinn University of Technology, Ehitajate Tee 5, Tallinn 19086 (Estonia); Ewert, M.; Falta, J. [Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen (Germany); MAPEX Center for Materials and Processes, University of Bremen, 28359 Bremen (Germany)

2016-07-25

In silicon thin-film solar cells the interface between the i- and p-layer is the most critical. In the case of back diffusion of photogenerated minority carriers to the i/p-interface, recombination occurs mainly on the defect states at the interface. To suppress this effect and to reduce recombination losses, hydrogen plasma treatment (HPT) is usually applied. As an alternative to using state of the art HPT we apply an argon plasma treatment (APT) before the p-layer deposition in n-i-p solar cells. To study the effect of APT, several investigations were applied to compare the results with HPT and no plasma treatment at the interface. Carrier collection losses in resulting solar cells were examined with spectral response measurements with and without bias voltage. To investigate single layers, surface photovoltage and X-ray photoelectron spectroscopy (XPS) measurements were conducted. The results with APT at the i/p-interface show a beneficial contribution to the carrier collection compared with HPT and no plasma treatment. Therefore, it can be concluded that APT reduces the recombination centers at the interface. Further, we demonstrate that carrier collection losses of thin-film solar cells are significantly lower with APT.

Protecting ICS Systems Within the Energy Sector from Cyber Attacks

Science.gov (United States)

Barnes, Shaquille

Advance persistent threat (APT) groups are continuing to attack the energy sector through cyberspace, which poses a risk to our society, national security, and economy. Industrial control systems (ICSs) are not designed to handle cyber-attacks, which is why asset owners need to implement the correct proactive and reactive measures to mitigate the risk to their ICS environments. The Industrial Control Systems Cyber Emergency Response Team (ICS-CERT) responded to 290 incidents for fiscal year 2016, where 59 of those incidents came from the Energy Sector. APT groups know how vulnerable energy sector ICS systems are and the destruction they can cause when they go offline such as loss of production, loss of life, and economic impact. Defending against APT groups requires more than just passive controls such as firewalls and antivirus solutions. Asset owners should implement a combination of best practices and active defense in their environment to defend against APT groups. Cyber-attacks against critical infrastructure will become more complex and harder to detect and respond to with traditional security controls. The purpose of this paper was to provide asset owners with the correct security controls and methodologies to help defend against APT groups.

An application of artificial intelligence to automatic telescopes

Science.gov (United States)

Swanson, Keith; Drummond, Mark; Bresina, John

1992-01-01

Automatic Photoelectric Telescopes (APT's) allow an astronomer to be removed form the telescope site in both time and space. APT's 'execute' an observation program (a set of observation requests) expressed in an ASCII-based language (ATIS) and collect observation results expressed in this same language. The observation program is currently constructed by a Principal Astronomer from the requests of multiple users; the execution is currently controlled by a simple heuristic dispatch scheduler. Research aimed at improving the use of APT's is being carried out by the Entropy Reduction Engine (ERE) project at NASA Ames. The overall goal of the ERE project is the study and construction of systems that integrate planning, scheduling, and control. This paper discusses the application of some ERE technical results to the improvement of both the scheduling and the operation of APT's.

Improved uniformity in high-performance organic photovoltaics enabled by (3-aminopropyl)triethoxysilane cathode functionalization.

Science.gov (United States)

Luck, Kyle A; Shastry, Tejas A; Loser, Stephen; Ogien, Gabriel; Marks, Tobin J; Hersam, Mark C

2013-12-28

Organic photovoltaics have the potential to serve as lightweight, low-cost, mechanically flexible solar cells. However, losses in efficiency as laboratory cells are scaled up to the module level have to date impeded large scale deployment. Here, we report that a 3-aminopropyltriethoxysilane (APTES) cathode interfacial treatment significantly enhances performance reproducibility in inverted high-efficiency PTB7:PC71BM organic photovoltaic cells, as demonstrated by the fabrication of 100 APTES-treated devices versus 100 untreated controls. The APTES-treated devices achieve a power conversion efficiency of 8.08 ± 0.12% with histogram skewness of -0.291, whereas the untreated controls achieve 7.80 ± 0.26% with histogram skewness of -1.86. By substantially suppressing the interfacial origins of underperforming cells, the APTES treatment offers a pathway for fabricating large-area modules with high spatial performance uniformity.

Nanometer-scale isotope analysis of bulk diamond by atom probe tomography

NARCIS (Netherlands)

Schirhagl, R.; Raatz, N.; Meijer, J.; Markham, M.; Gerstl, S. S. A.; Degen, C. L.

2015-01-01

Atom-probe tomography (APT) combines field emission of atoms with mass spectrometry to reconstruct three-dimensional tomograms of materials with atomic resolution and isotope specificity. Despite significant recent progress in APT technology, application to wide-bandgap materials with strong

Calibration of full-scale accelerated pavement testing data using long-term pavement performance data

CSIR Research Space (South Africa)

VdM Steyn, WJ

2012-09-01

Full Text Available Accelerated Pavement Testing (APT) has always been conducted with the objective of improving the understanding of real pavements under real traffic and environmental conditions. While APT provides an accelerated view of some of the major structural...

Advanced public transportation systems : evaluation guidelines

Science.gov (United States)

1994-01-01

The Federal Transit Administration has developed the Advanced Public Transportation Systems (APTS) Program which is an integral part of the overall U.S. DOT Intelligent Vehicle Highway Systems (IVHS) effort. A major aim of the APTS Program is to prom...

Exposure Control for Operations and Maintenance at the Accelerator Production of Tritium

International Nuclear Information System (INIS)

McGuire, D.H.

1998-09-01

The APT will be designed and operated to support continuous tritium production. Tritium is an essential ingredient in U.S. nuclear weapons. The APT will be designed and staffed to support continuous production of tritium by trained, qualified, and certified personnel

Astronomical tuning and magnetostratigraphy of the Upper Triassic Xujiahe Formation of South China and Newark Supergroup of North America: Implications for the Late Triassic time scale

Science.gov (United States)

Li, Mingsong; Zhang, Yang; Huang, Chunju; Ogg, James; Hinnov, Linda; Wang, Yongdong; Zou, Zhuoyan; Li, Liqin

2017-10-01

The time scale of the Late Triassic Epoch has a divergence of age models, especially for the durations of competing definitions for its Rhaetian Stage (uppermost Triassic). The astrochronology derived from relative depth of lacustrine-bearing clastic successions and astronomically tuned geomagnetic polarity time scale (APTS) of the Newark Supergroup of eastern North America provides a basis for the Late Triassic time scale. However, the Newark APTS has been challenged regarding its age scale and completeness; therefore an independent astronomical-tuned magnetic polarity zonation is required to verify the upper Newark APTS reference scale. We compiled a 6.5 million year (myr) APTS with magnetic stratigraphy from four sections of the lacustrine-fluvial, dinosaur-track-bearing Xujiahe Formation in the Sichuan Basin of South China that also has dating from detrital zircons and regional biostratigraphy. Variations in natural gamma-ray and magnetic susceptibility that reflect variable continental weathering in the source regions of the Xujiahe Formation are paced by Milankovitch cycles, especially the 100-kyr short eccentricity and 405-kyr long eccentricity. The cycle-tuned magnetostratigraphy of the Xujiahe Formation is compared directly via the magnetic-polarity zones to the depth ranks of the Newark Supergroup that are indicative of relative depths of lacustrine facies. The Sichuan APTS indicates that there is no significant hiatus between the sedimentary succession and the basalt flows at the top of the Newark Supergroup. The Sichuan APTS is compatible with the magnetostratigraphy from the candidate Global Boundary Stratotype Section and Point (GSSP) for the Norian-Rhaetian boundary interval at the Pignola-Abriola of South Italy, but does not extend downward to the proposed GSSP in Austria associated with the longer Rhaetian option. The earliest dinosaur tracks in China are from the middle of this Xujiahe Formation, therefore are implied to be middle Rhaetian in age

Astrochronology and magnetostratigraphy of the Xujiahe Formation of South China and Newark Supergroup of North America: implications for the Late Triassic time scale

Science.gov (United States)

Li, M.; Zhang, Y.; Huang, C.; Ogg, J. G.; Hinnov, L.; Wang, Y.; Zou, Z.; Li, L.; Grasby, S. E.; Zhong, Y.; Huang, K.

2017-12-01

The astrochronology derived from lacustrine clastic successions tied to the geomagnetic polarity time scale of the Newark Supergroup of eastern North America, known as the Newark APTS provides a basis for the Late Triassic time scale. However, the Newark APTS has been challenged regarding its age scale and completeness; therefore an independent astronomically tuned magnetic polarity zonation is required to verify the upper Newark APTS reference scale. We have compiled a 6.5 million year (myr) APTS with magnetic stratigraphy from four sections of the lacustrine-fluvial, dinosaur-track-bearing Xujiahe Formation in the Sichuan Basin of South China that has dating from detrital zircons and regional biostratigraphy. Variations in natural gamma-ray and magnetic susceptibility that reflect variable continental weathering in the source regions of the Xujiahe Formation are paced by Milankovitch cycles, especially the 100-kyr short eccentricity and 405-kyr long eccentricity. The cycle-tuned magnetostratigraphy of the Xujiahe Formation is compared directly via the magnetic-polarity zones to the depth ranks of the Newark Supergroup that are indicative of relative depositional depths of lacustrine facies. The Sichuan APTS indicates that there is no significant hiatus between the sedimentary succession and the basalt flows at the top of the Newark Supergroup. The Sichuan APTS is compatible with the magnetostratigraphy from the candidate Global Boundary Stratotype Section and Point (GSSP) for the Norian-Rhaetian boundary interval at the Pignola-Abriola section of South Italy, but does not extend downward to the proposed GSSP in Austria associated with the longer Rhaetian option. The earliest dinosaur tracks in China are from the middle of the Xujiahe Formation, therefore are implied to be middle Rhaetian in age. The Sichuan APTS helps to resolve the controversy about the completeness and reliability of the Newark APTS, and can be used in the future to verify if isotopic

Epithelial cell adhesion molecule aptamer functionalized PLGA-lecithin-curcumin-PEG nanoparticles for targeted drug delivery to human colorectal adenocarcinoma cells

Directory of Open Access Journals (Sweden)

Li L

2014-02-01

Full Text Available Lei Li,1,* Dongxi Xiang,2,* Sarah Shigdar,2 Wenrong Yang,3 Qiong Li,2 Jia Lin,4 Kexin Liu,1 Wei Duan2 1College of Pharmacy, Dalian Medical University, Dalian, People's Republic of China; 2School of Medicine, Faculty of Health, Deakin University, Waurn Ponds, VIC, Australia; 3School of Life and Environmental Sciences, Faculty of Science, Engineering and Built Environment, Deakin University, Waurn Ponds, VIC, Australia; 4Department of Biochemistry and Molecular Biology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, People's Republic of China *These authors contributed equally to this work Abstract: To improve the efficacy of drug delivery, active targeted nanotechnology-based drug delivery systems are gaining considerable attention as they have the potential to reduce side effects, minimize toxicity, and improve efficacy of anticancer treatment. In this work CUR-NPs (curcumin-loaded lipid-polymer-lecithin hybrid nanoparticles were synthesized and functionalized with ribonucleic acid (RNA Aptamers (Apts against epithelial cell adhesion molecule (EpCAM for targeted delivery to colorectal adenocarcinoma cells. These CUR-encapsulated bioconjugates (Apt-CUR-NPs were characterized for particle size, zeta potential, drug encapsulation, stability, and release. The in vitro specific cell binding, cellular uptake, and cytotoxicity of Apt-CUR-NPs were also studied. The Apt-CUR-NP bioconjugates exhibited increased binding to HT29 colon cancer cells and enhancement in cellular uptake when compared to CUR-NPs functionalized with a control Apt (P<0.01. Furthermore, a substantial improvement in cytotoxicity was achieved toward HT29 cells with Apt-CUR-NP bioconjugates. The encapsulation of CUR in Apt-CUR-NPs resulted in the increased bioavailability of delivered CUR over a period of 24 hours compared to that of free CUR in vivo. These results show that the EpCAM Apt-functionalized CUR-NPs enhance the targeting and drug

Eco-friendly one-pot synthesis of highly dispersible functionalized graphene nanosheets with free amino groups

International Nuclear Information System (INIS)

Liu Zhiting; Duan Xuezhi; Qian Gang; Zhou Xinggui; Yuan Weikang

2013-01-01

An eco-friendly, facile and scalable hydrothermal approach, in which the reduction and functionalization of graphite oxide (GO) are completed in one pot, is proposed for the synthesis of monolayer 3-aminopropyltriethoxysilane (APTES)-functionalized graphenes (A-FGs). Atomic force microscopy, transmission electron microscopy and x-ray diffraction analyses indicate that the as-synthesized A-FGs consist of only one or a few layered graphenes, while x-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis reveal that APTES is bonded to graphene by the dehydration reaction between the Si–OH (produced by APTES hydration) and the –OH on the GO surface. As a result, free amino groups are left on the A-FGs. Moreover, A-FGs are highly dispersible in dimethylsulfoxide, APTES and ethylene glycol, and their solubilities are up to 0.89, 4.03 and 0.90 mg ml −1 , respectively. (paper)

Optimized monolayer grafting of 3-aminopropyltriethoxysilane onto amorphous, anatase and rutile TiO 2

Science.gov (United States)

Song, Yan-Yan; Hildebrand, Helga; Schmuki, Patrik

2010-02-01

Experimental conditions were studied for optimized attachment of 3-aminopropyltriethoxysilane (APTES) onto amorphous, anatase and rutile titanium dioxide (TiO 2) surfaces. The attachment process and extent was characterized using X-ray photoelectron spectroscopy (XPS). In particular, the effect of attachment time, silane concentration, reaction temperature and the TiO 2 crystalline structure on the growth kinetics of the silane layers was studied. The measurements reveal that typically monolayers are more dense on amorphous than on crystalline TiO 2. The results show that critical experimental conditions exist where APTES attachment to the TiO 2 surface changes from a monolayer to a multilayer growth mode. The obtained results and parameters to produce optimized APTES layers are of a high practical relevance as APTES attachment often constitutes the initial step for organic modification of TiO 2 surface with biorelevant molecules such as proteins, enzymes or growth factors.

The Characteristics of Fibres within Coppiced and Non-Coppiced Rosewood (Pterocarpus erinaceus Poir. and their Aptness for Wood - and Paper - Based Products

Directory of Open Access Journals (Sweden)

Frederick ANTHONIO

2017-06-01

Full Text Available Rosewood (Pterocarpus erinaceus is highly priced for furniture, flooring and cabinetry for its rich hue and durability. Its coppiced wood augments the timber for regular supply and sustainable utilization. Fibre morphology from macerated slivers within its coppiced and non-coppiced stems and their utilization potential were assessed. Derived ratios for the fibres were also calculated. The axial positions (butt, middle, crown affected the fibre dimensions. Fibre length was greater for coppiced trees [i.e., 1663±11, 1488±5, 1511±10µm (for sapwood and 1498±10, 1486±9, 1394±4µm (for heartwood] than the non-coppiced [i.e., 1240±7, 1013±5, 1137±5µm (sapwood and 1094±8, 1002±2, 1041±9µm (heartwood]. In all, those for sapwoods were greater than heartwoods’. Significant differences (P˂0.05 existed between fibre lengths from the coppiced (1394±4-1663±11µm and non-coppiced trees (1002±2-1240±7µm. Fibre diameters for coppiced sapwood and heartwood were 23±1, 20±1, 22±0.8µm and 21.5±0.3, 20.7±0.5, 21.3±2µm and noncoppiced recorded 21±0.6, 20.7±0.3, 20.6±0.1µm and 21±0, 21±0.4, 21±0.8µm respectively. Their respective double wall thicknesses were 8.4±0.2, 7.2±0.2, 9.4±1µm and 8.2±0.2, 9±0.3, 9.1±0.4µm for coppiced wood, and 9.1±1, 7.8±0.1, 8.1±0.3µm and 8.5±0.3, 8±0.4, 8±1 for non-coppiced. Thus, radial stem position also influenced fibre morphology. The fibre indices [i.e., Runkel Ratio, Slenderness Ratio and Flexibility Coefficient for coppiced wood (0.6±0.06-0.85±0.06, 68±4-77±6, 56±4-64±2 respectively and non-coppiced (0.64±0.12-0.8±0, 49±1-58±4, 57±3-62±2 respectively] indicate the timber’s aptness for pulp and paper. Besides, the Wood Industry could exploit the fibre characteristics of coppiced wood also for engineering of fibre-based products and structural applications.

Control and Prevention of Ice Formation on the Surface of an Aluminum Alloy

DEFF Research Database (Denmark)

Rahimi, Maral

modified with (3-aminopropyl) triethoxy silane (APTES) exhibited longer freezing delays as compared to both more hydrophilic and more hydrophobic substrates. This is attributed to a particular surface chemistry of the APTES modification that prevents ice formation at the interface of the substrate due...

Theater for Peace: Reflections on the Amani People´s Theater Model

DEFF Research Database (Denmark)

Awino, Okech; Owiso, Michael

2018-01-01

approaches, as utilized by Amani People´s Theater (APT) in Kenya are traced to provide the practicum perspective. APT is an organization that employs multi-arts approaches to peacebuilding since 1994. The organization implemented an intervention dubbed ``Building Sustainable Structures for Peace`` from 2007...

Linear accelerator for production of tritium: Physics design challenges

Energy Technology Data Exchange (ETDEWEB)

Wangler, T.P.; Lawrence, G.P.; Bhatia, T.S.; Billen, J.H.; Chan, K.C.D.; Garnett, R.W.; Guy, F.W.; Liska, D.; Nath, S.; Neuschaefer, G.; Shubaly, M.

1990-01-01

In the summer of 1989, a collaboration between Los Alamos National Laboratory and Brookhaven National Laboratory conducted a study to establish a reference design of a facility for accelerator production of tritium (APT). The APT concept is that of a neutron-spallation source, which is based on the use of high-energy protons to bombard lead nuclei, resulting in the production of large quantities of neutrons. Neutrons from the lead are captured by lithium to produce tritium. This paper describes the design of a 1.6-GeV, 250-mA proton cw linear accelerator for APT.

A sonochemical approach to the direct surface functionalization of superparamagnetic iron oxide nanoparticles with (3-aminopropyl)triethoxysilane.

Science.gov (United States)

Sodipo, Bashiru Kayode; Aziz, Azlan Abdul

2014-01-01

We report a sonochemical method of functionalizing superparamagnetic iron oxide nanoparticles (SPION) with (3-aminopropyl)triethoxysilane (APTES). Mechanical stirring, localized hot spots and other unique conditions generated by an acoustic cavitation (sonochemical) process were found to induce a rapid silanization reaction between SPION and APTES. FTIR, XPS and XRD measurements were used to demonstrate the grafting of APTES on SPION. Compared to what was reported in literature, the results showed that the silanization reaction time was greatly minimized. More importantly, the product displayed superparamagnetic behaviour at room temperature with a more than 20% higher saturation magnetization.

Machine Tool Software

Science.gov (United States)

1988-01-01

A NASA-developed software package has played a part in technical education of students who major in Mechanical Engineering Technology at William Rainey Harper College. Professor Hack has been using (APT) Automatically Programmed Tool Software since 1969 in his CAD/CAM Computer Aided Design and Manufacturing curriculum. Professor Hack teaches the use of APT programming languages for control of metal cutting machines. Machine tool instructions are geometry definitions written in APT Language to constitute a "part program." The part program is processed by the machine tool. CAD/CAM students go from writing a program to cutting steel in the course of a semester.

Defending Against Advanced Persistent Threats Using Game-Theory.

Science.gov (United States)

Rass, Stefan; König, Sandra; Schauer, Stefan

2017-01-01

Advanced persistent threats (APT) combine a variety of different attack forms ranging from social engineering to technical exploits. The diversity and usual stealthiness of APT turns them into a central problem of contemporary practical system security, since information on attacks, the current system status or the attacker's incentives is often vague, uncertain and in many cases even unavailable. Game theory is a natural approach to model the conflict between the attacker and the defender, and this work investigates a generalized class of matrix games as a risk mitigation tool for an advanced persistent threat (APT) defense. Unlike standard game and decision theory, our model is tailored to capture and handle the full uncertainty that is immanent to APTs, such as disagreement among qualitative expert risk assessments, unknown adversarial incentives and uncertainty about the current system state (in terms of how deeply the attacker may have penetrated into the system's protective shells already). Practically, game-theoretic APT models can be derived straightforwardly from topological vulnerability analysis, together with risk assessments as they are done in common risk management standards like the ISO 31000 family. Theoretically, these models come with different properties than classical game theoretic models, whose technical solution presented in this work may be of independent interest.

Influence of the surface free energy of silane-coupled mica substrate on the fixing and straightening of DNA

International Nuclear Information System (INIS)

Sasou, Megumi; Sugiyama, Shigeru; Ishida, Takao; Ohtani, Toshio; Miyake, Koji

2009-01-01

Methyltrimethoxysilane (MTMS)-coupled mica substrate is reportedly suitable for fixing and straightening of DNA, but 3-aminopropyltriethoxysilane (APTES)-coupled mica substrate has been found less suitable. On MTMS-coupled mica substrate, the straightness of fixed DNA was sufficient, and the adsorption of contaminants was not observed using fluorescence microscopy and atomic force microscopy. For the APTES-coupled mica substrate, however, aggregated or curved DNA and adsorption of contaminants were observed. To clarify the surface factors that are responsible for this suitability, we analyzed the surface free energies of these substrates using the extended Fowkes theory. In each of the surface free energy components, the dispersion force component in the MTMS-coupled mica substrate was lower than that in the APTES-coupled mica substrate. The ratio of the polar force component on the MTMS-coupled mica substrate was about one order of magnitude on the APTES-coupled mica substrate. In addition, the ratio of the hydrogen-bonding force component for the MTMS-coupled mica substrate was about two times larger than that of the APTES-coupled mica substrate. These results suggest that the polar force and hydrogen-bonding force components are important factors for the fixation and straightening of DNA and that the dispersion force components influence the production and adsorption of contaminants.

Development of silane grafted ZnO core shell nanoparticles loaded diglycidyl epoxy nanocomposites film for antimicrobial applications.

Science.gov (United States)

Suresh, S; Saravanan, P; Jayamoorthy, K; Ananda Kumar, S; Karthikeyan, S

2016-07-01

In this article a series of epoxy nanocomposites film were developed using amine functionalized (ZnO-APTES) core shell nanoparticles as the dispersed phase and a commercially available epoxy resin as the matrix phase. The functional group of the samples was characterized using FT-IR spectra. The most prominent peaks of epoxy resin were found in bare epoxy and in all the functionalized ZnO dispersed epoxy nanocomposites (ZnO-APTES-DGEBA). The XRD analysis of all the samples exhibits considerable shift in 2θ, intensity and d-spacing values but the best and optimum concentration is found to be 3% ZnO-APTES core shell nanoparticles loaded epoxy nanocomposites supported by FT-IR results. From TGA measurements, 100wt% residue is obtained in bare ZnO nanoparticles whereas in ZnO core shell nanoparticles grafted DGEBA residue percentages are 37, 41, 45, 46 and 52% for 0, 1, 3, 5 and 7% ZnO-APTES-DGEBA respectively, which is confirmed with ICP-OES analysis. From antimicrobial activity test, it was notable that antimicrobial activity of 7% ZnO-APTES core shell nanoparticles loaded epoxy nanocomposite film has best inhibition zone effect against all pathogens under study. Copyright © 2016 Elsevier B.V. All rights reserved.

Encapsulation method for atom probe tomography analysis of nanoparticles

International Nuclear Information System (INIS)

Larson, D.J.; Giddings, A.D.; Wu, Y.; Verheijen, M.A.; Prosa, T.J.; Roozeboom, F.; Rice, K.P.; Kessels, W.M.M.; Geiser, B.P.; Kelly, T.F.

2015-01-01

Open-space nanomaterials are a widespread class of technologically important materials that are generally incompatible with analysis by atom probe tomography (APT) due to issues with specimen preparation, field evaporation and data reconstruction. The feasibility of encapsulating such non-compact matter in a matrix to enable APT measurements is investigated using nanoparticles as an example. Simulations of field evaporation of a void, and the resulting artifacts in ion trajectory, underpin the requirement that no voids remain after encapsulation. The approach is demonstrated by encapsulating Pt nanoparticles in an ZnO:Al matrix created by atomic layer deposition, a growth technique which offers very high surface coverage and conformality. APT measurements of the Pt nanoparticles are correlated with transmission electron microscopy images and numerical simulations in order to evaluate the accuracy of the APT reconstruction. - Highlights: • Pt nanoparticles were analyzed using atom probe tomography and TEM. • The particles were prepared by encapsulation using atomic layer deposition. • Simulation of field evaporation near a void results in aberrations in ion trajectories. • Apparent differences between TEM and APT analyses are reconciled through simulation of field evaporation from a low-field matrix containing high-field NPs; ion trajectory aberrations are shown to lead to an apparent mixing of the matrix into the NPs.

78 FR 36232 - Announcement of Funding Awards; Service Coordinators in Multifamily Housing Program, Fiscal Year...

Science.gov (United States)

2013-06-17

.......... Chase Manor Chase Manor.... 55-75 Norman Norwich 50 245,565 Associates. Road. CT....... Southern... St. The Green 2412 Franklin Washington 100 124,177 Paul Housing Valley Apts. St Ne. Inc. FL... Apts. MA....... Taunton Green Taunton Green.. 31 School St... Taunton 75 237,008 Associates. MA...

Lessons Learned from Field Operational Test of Integrated Network Management in Amsterdam

NARCIS (Netherlands)

Hoogendoorn, S.P.; van Kooten, J; Adams, R

2016-01-01

The Amsterdam Practical Trial (APT) is a multiyear program initiated by the Dutch Ministry of Transport and the Environment and is carried out in close cooperation by Rijkswaterstaat, the City of Amsterdam, the Province of North Holland, and the Amsterdam Metropolitan Region. The APT aims to

Covalently Immobilised Cytochrome C Imaged by In Situ Scanning Tunnelling Microscopy

DEFF Research Database (Denmark)

Andersen, Jens Enevold Thaulov; Olesen, Klaus G.; Danilov, Alexey I.

1997-01-01

In situ scanning tunnelling microscopy (STM) imaging of cytochrome c (cyt c) on polycrystalline Pt surfaces and on Au(lll) was achieved first by covalent immobilisation of 3-aminopropyltriethoxysilane (3-APTS) brought to react with oxide present on the Pt surfaces. Covalently bound 3-APTS forms...

First-principles investigation on the composition of Ni-Si precipitates formed in irradiated stainless steels

Science.gov (United States)

Chen, Dongyue; Murakami, Kenta; Dohi, Kenji; Nishida, Kenji; Ohnuma, Toshiharu; Soneda, Naoki; Li, Zhengcao; Liu, Li; Sekimura, Naoto

2017-10-01

Recent atom probe tomography (APT) study has revealed the complicated nature of Ni-Si precipitates in irradiated stainless steels. Although Ni3Si γ‧ phase has been confirmed under transmission electron microscopy (TEM), the Ni/Si ratio of the precipitates detected by APT is smaller than its theoretical value 3. An interpretation of the APT results is provided in this work by considering the lattice defects in the Ni3Si γ‧ phase. Using first principles calculations, Si substitutions on Ni sites were found to be the most thermodynamically stable among all the single defects considered here. Although two such substitutional defects are repulsive to each other, the repulsion decreases quickly as their separation distance grows. By keeping a large enough distance between each other, multiple Si substitutions can appear at high densities in the γ‧ phase, which can be one important contributor to the small Ni/Si atom ratio in Ni-Si precipitates observed by APT.

High-Resolution Characterization of UMo Alloy Microstructure

Energy Technology Data Exchange (ETDEWEB)

Devaraj, Arun [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kovarik, Libor [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jana, Saumyadeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Manandhar, Sandeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Arey, Bruce W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-11-30

This report highlights the capabilities and procedure for high-resolution characterization of UMo fuels in PNNL. Uranium-molybdenum (UMo) fuel processing steps, from casting to forming final fuel, directly affect the microstructure of the fuel, which in turn dictates the in-reactor performance of the fuel under irradiation. In order to understand the influence of processing on UMo microstructure, microstructure characterization techniques are necessary. Higher-resolution characterization techniques like transmission electron microscopy (TEM) and atom probe tomography (APT) are needed to interrogate the details of the microstructure. The findings from TEM and APT are also directly beneficial for developing predictive multiscale modeling tools that can predict the microstructure as a function of process parameters. This report provides background on focused-ion-beam–based TEM and APT sample preparation, TEM and APT analysis procedures, and the unique information achievable through such advanced characterization capabilities for UMo fuels, from a fuel fabrication capability viewpoint.

Indium clustering in a-plane InGaN quantum wells as evidenced by atom probe tomography

International Nuclear Information System (INIS)

Tang, Fengzai; Zhu, Tongtong; Oehler, Fabrice; Fu, Wai Yuen; Griffiths, James T.; Massabuau, Fabien C.-P.; Kappers, Menno J.; Oliver, Rachel A.; Martin, Tomas L.; Bagot, Paul A. J.; Moody, Michael P.

2015-01-01

Atom probe tomography (APT) has been used to characterize the distribution of In atoms within non-polar a-plane InGaN quantum wells (QWs) grown on a GaN pseudo-substrate produced using epitaxial lateral overgrowth. Application of the focused ion beam microscope enabled APT needles to be prepared from the low defect density regions of the grown sample. A complementary analysis was also undertaken on QWs having comparable In contents grown on polar c-plane sample pseudo-substrates. Both frequency distribution and modified nearest neighbor analyses indicate a statistically non-randomized In distribution in the a-plane QWs, but a random distribution in the c-plane QWs. This work not only provides insights into the structure of non-polar a-plane QWs but also shows that APT is capable of detecting as-grown nanoscale clustering in InGaN and thus validates the reliability of earlier APT analyses of the In distribution in c-plane InGaN QWs which show no such clustering

Indium clustering in a-plane InGaN quantum wells as evidenced by atom probe tomography

Energy Technology Data Exchange (ETDEWEB)

Tang, Fengzai; Zhu, Tongtong; Oehler, Fabrice; Fu, Wai Yuen; Griffiths, James T.; Massabuau, Fabien C.-P.; Kappers, Menno J.; Oliver, Rachel A., E-mail: rao28@cam.ac.uk [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Martin, Tomas L.; Bagot, Paul A. J.; Moody, Michael P., E-mail: michael.moody@materials.ox.ac.uk [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom)

2015-02-16

Atom probe tomography (APT) has been used to characterize the distribution of In atoms within non-polar a-plane InGaN quantum wells (QWs) grown on a GaN pseudo-substrate produced using epitaxial lateral overgrowth. Application of the focused ion beam microscope enabled APT needles to be prepared from the low defect density regions of the grown sample. A complementary analysis was also undertaken on QWs having comparable In contents grown on polar c-plane sample pseudo-substrates. Both frequency distribution and modified nearest neighbor analyses indicate a statistically non-randomized In distribution in the a-plane QWs, but a random distribution in the c-plane QWs. This work not only provides insights into the structure of non-polar a-plane QWs but also shows that APT is capable of detecting as-grown nanoscale clustering in InGaN and thus validates the reliability of earlier APT analyses of the In distribution in c-plane InGaN QWs which show no such clustering.

Probing the nanostructural evolution of age-hardenable Al alloys with atom-probe tomography

International Nuclear Information System (INIS)

Biswas, Aniruddha

2010-01-01

Atom Probe Tomographic (APT) Microscope is a lens-less point-projection 3-D analytical microscope that has the unique capability of (i) three-dimensional imaging at the atomic scale and (ii) compositional analysis with sub-nanometre spatial resolution and single-atom sensitivity. Modern 3-D APT microscope offers the highest the spatial resolution among all the available analytical techniques. It can simultaneously achieve a spatial resolution better than 0.3 nm in all three directions of a three-dimensional analysis-volume. As a result, 3-D APT microscopy, especially as practiced by the high speed, large field of view instruments is the most appropriate tool for studying nano-scale precipitates and their heterophase interfaces. This talk will introduce the technique, discuss its brief historical background and use examples from age-hardenable Al-alloys. The results include a detailed APT study of the compositional evolution of the nano-scale precipitates: θ and Q present in commercial age hardenable aluminium alloy, W319

Controlling the Nanoscale Patterning of AuNPs on Silicon Surfaces

Directory of Open Access Journals (Sweden)

Chris J. Allender

2013-03-01

Full Text Available This study evaluates the effectiveness of vapour-phase deposition for creating sub-monolayer coverage of aminopropyl triethoxysilane (APTES on silicon in order to exert control over subsequent gold nanoparticle deposition. Surface coverage was evaluated indirectly by observing the extent to which gold nanoparticles (AuNPs deposited onto the modified silicon surface. By varying the distance of the silicon wafer from the APTES source and concentration of APTES in the evaporating media, control over subsequent gold nanoparticle deposition was achievable to an extent. Fine control over AuNP deposition (AuNPs/μm2 however, was best achieved by adjusting the ionic concentration of the AuNP-depositing solution. Furthermore it was demonstrated that although APTES was fully removed from the silicon surface following four hours incubation in water, the gold nanoparticle-amino surface complex was stable under the same conditions. Atomic force microscopy (AFM and X-ray photoelectron spectroscopy (XPS were used to study these affects.

Immobilization of streptavidin on 4H-SiC for biosensor development

International Nuclear Information System (INIS)

Williams, Elissa H.; Davydov, Albert V.; Motayed, Abhishek; Sundaresan, Siddarth G.; Bocchini, Peter; Richter, Lee J.; Stan, Gheorghe; Steffens, Kristen; Zangmeister, Rebecca; Schreifels, John A.; Rao, Mulpuri V.

2012-01-01

A sequential layer formation chemistry is demonstrated for the functionalization of silicon carbide (SiC) appropriate to biosensing applications. (0 0 0 1) 4H-SiC was functionalized with 3-aminopropyltriethoxysilane (APTES) and subsequently biotinylated for the selective immobilization of streptavidin. Atomic force microscopy, X-ray photoelectron spectroscopy, ellipsometry, fluorescence microscopy, and contact angle measurements were utilized to determine the structure, thickness, wettability, and reactivity of the resulting surface after each functionalization step. Optimization of the APTES layer was found to be critical to the success of the subsequent steps; multilayer, polymeric films resulted in irreproducible behavior. It was shown that there was significant non-specific (electrostatic) binding of streptavidin to APTES functionalized SiC, thus revealing the importance of a uniform biotinylation step prior to streptavidin attachment. The experimental results demonstrate that the APTES functionalized and biotinylated SiC surface has the potential to be employed as a biosensing platform for the selective detection of streptavidin molecules.

Estatus ponderal y aptitud cardiorrespiratoria en escolares de la región central del Perú

Directory of Open Access Journals (Sweden)

Alcibíades Bustamante

Full Text Available Objetivos. Determinar la frecuencia del sobrepeso y obesidad, en función a los niveles de aptitud cardiorrespiratoria (AptCR en escolares de cuatro distritos de la región central del Perú, y analizar la asociación entre estas variables. Materiales y métodos. El peso, altura y la AptCR fueron evaluados en 7841 escolares que residen en cuatro distritos ubicados en la costa, sierra y selva de la región central del Perú. El sobrepeso y la obesidad fueron clasificados según los criterios propuestos por Cole. La AptCR fue evaluada mediante la prueba de correr/caminar de doce minutos de la batería de la American Alliance for Health, Recreation and Dance. Se utilizó el ANOVA y la regresión logística para examinar las diferencias de las medias y asociaciones entre estas variables. Resultados. Escolares de ambos sexos presentan frecuencias semejantes de sobrepeso y obesidad (20,9% en mujeres y 20,1% en varones. Residentes en la costa (Barranco manifiestan elevadas frecuencias de sobrepeso y obesidad (37,8%. La edad, el sexo, área geográfica y la AptCR fueron predictores significativos para el sobrepeso y la obesidad. Escolares que viven en Barranco tienen cinco veces más probabilidades de ser obesos (OR=4,67; IC95%: 3,55-6,14; los que residen en la sierra (Junín tienen una menor probabilidad de ser obesos (OR=0,03; IC95%: 0,01-0,20; y quienes muestran una baja AptCR tienen una mayor probabilidad de ser obesos (OR=11 ,82; IC95%: 7,25-19,27, en comparación con aquellos con alta AptCR. Conclusiones. Los escolares que residen en Barranco presentan frecuencias de sobrepeso y obesidad elevados. Una baja AptCR está asociada al desarrollo del sobrepeso y la obesidad

Guided mass spectrum labelling in atom probe tomography

International Nuclear Information System (INIS)

Haley, D.; Choi, P.; Raabe, D.

2015-01-01

Atom probe tomography (APT) is a valuable near-atomic scale imaging technique, which yields mass spectrographic data. Experimental correctness can often pivot on the identification of peaks within a dataset, this is a manual process where subjectivity and errors can arise. The limitations of manual procedures complicate APT experiments for the operator and furthermore are a barrier to technique standardisation. In this work we explore the capabilities of computer-guided ranging to aid identification and analysis of mass spectra. We propose a fully robust algorithm for enumeration of the possible identities of detected peak positions, which assists labelling. Furthermore, a simple ranking scheme is developed to allow for evaluation of the likelihood of each possible identity being the likely assignment from the enumerated set. We demonstrate a simple, yet complete work-chain that allows for the conversion of mass-spectra to fully identified APT spectra, with the goal of minimising identification errors, and the inter-operator variance within APT experiments. This work chain is compared to current procedures via experimental trials with different APT operators, to determine the relative effectiveness and precision of the two approaches. It is found that there is little loss of precision (and occasionally gain) when participants are given computer assistance. We find that in either case, inter-operator precision for ranging varies between 0 and 2 “significant figures” (2σ confidence in the first n digits of the reported value) when reporting compositions. Intra-operator precision is weakly tested and found to vary between 1 and 3 significant figures, depending upon species composition levels. Finally it is suggested that inconsistencies in inter-operator peak labelling may be the largest source of scatter when reporting composition data in APT. - Highlights: • Demonstration of a complete, but simple, automation chain for APT spectra analysis. • Algorithm for

Guided mass spectrum labelling in atom probe tomography

Energy Technology Data Exchange (ETDEWEB)

Haley, D., E-mail: daniel.haley@materials.ox.ac.uk [Max-Planck-Institut für Eisenforschung, Max-Plack Straße 1, Düsseldorf (Germany); Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Choi, P.; Raabe, D. [Max-Planck-Institut für Eisenforschung, Max-Plack Straße 1, Düsseldorf (Germany)

2015-12-15

Atom probe tomography (APT) is a valuable near-atomic scale imaging technique, which yields mass spectrographic data. Experimental correctness can often pivot on the identification of peaks within a dataset, this is a manual process where subjectivity and errors can arise. The limitations of manual procedures complicate APT experiments for the operator and furthermore are a barrier to technique standardisation. In this work we explore the capabilities of computer-guided ranging to aid identification and analysis of mass spectra. We propose a fully robust algorithm for enumeration of the possible identities of detected peak positions, which assists labelling. Furthermore, a simple ranking scheme is developed to allow for evaluation of the likelihood of each possible identity being the likely assignment from the enumerated set. We demonstrate a simple, yet complete work-chain that allows for the conversion of mass-spectra to fully identified APT spectra, with the goal of minimising identification errors, and the inter-operator variance within APT experiments. This work chain is compared to current procedures via experimental trials with different APT operators, to determine the relative effectiveness and precision of the two approaches. It is found that there is little loss of precision (and occasionally gain) when participants are given computer assistance. We find that in either case, inter-operator precision for ranging varies between 0 and 2 “significant figures” (2σ confidence in the first n digits of the reported value) when reporting compositions. Intra-operator precision is weakly tested and found to vary between 1 and 3 significant figures, depending upon species composition levels. Finally it is suggested that inconsistencies in inter-operator peak labelling may be the largest source of scatter when reporting composition data in APT. - Highlights: • Demonstration of a complete, but simple, automation chain for APT spectra analysis. • Algorithm for

Journal of Biosciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Biosciences. Shree Kumar Apte. Articles written in Journal of Biosciences. Volume 29 Issue 2 June 2004 pp 153-161 Articles. A novel potassium deficiency-induced stimulon in Anabaena torulosa · Anuradha Alahari Shree Kumar Apte · More Details Abstract Fulltext PDF. Potassium deficiency ...

Both antiplatelet and anticoagulant therapy may favorably affect outcome in patients with advanced heart failure. A retrospective analysis of the PRIME-II trial

NARCIS (Netherlands)

de Boer, RA; Hillege, HL; Tjeerdsma, G; Verheugt, FWA; van Veldhuisen, DJ

2005-01-01

Introduction: Current guidelines of chronic heart failure (CHF) do not recommend the use of oral anticoagulants (OAC) or antiptatelet therapy (APT). We performed a post-hoc analysis to evaluate the effect of the use of anti-thrombotic therapy with APT and OAC. Patients and methods: We examined 427

Amide proton transfer imaging of high intensity focused ultrasound-treated tumor tissue

NARCIS (Netherlands)

Hectors, S.J.C.G.; Jacobs, I.; Strijkers, G.J.; Nicolay, K.

2014-01-01

Purpose: In this study, the suitability of amide proton transfer (APT) imaging as a biomarker for the characterization of high intensity focused ultrasound (HIFU)-treated tumor tissue was assessed. Methods: APT imaging was performed on tumor-bearing mice before (n=15), directly after (n=15) and at 3

Amide Proton Transfer Imaging of High Intensity Focused Ultrasound-Treated Tumor Tissue

NARCIS (Netherlands)

Hectors, Stefanie J. C. G.; Jacobs, Igor; Strijkers, Gustav J.; Nicolay, Klaas

2014-01-01

PurposeIn this study, the suitability of amide proton transfer (APT) imaging as a biomarker for the characterization of high intensity focused ultrasound (HIFU)-treated tumor tissue was assessed. MethodsAPT imaging was performed on tumor-bearing mice before (n=15), directly after (n=15) and at 3

Factors affecting production of an antilisterial bacteriocin by Carnobacterium piscicola strain A9b in laboratory media and model fish systems

DEFF Research Database (Denmark)

Himelbloom, B.; Nilsson, Lilian; Gram, Lone

2001-01-01

in APT broth when a low inoculum level (0.001%) was used. In contrast, inoculum level did not influence bacteriocin production in BHI and MRS7 without glucose. Bacteriocin production in APT was induced by the presence of an extracellular compound present in the sterile, filtered, cell- free supernatant...

Both antiplatelet and anticoagulant therapy may favorably affect outcome in patients with advanced heart failure. A retrospective analysis of the PRIME-II trial.

NARCIS (Netherlands)

Boer, R.A. de; Hillege, H.L.; Tjeerdsma, G.; Verheugt, F.W.A.; Veldhuisen, D.J. van

2005-01-01

INTRODUCTION: Current guidelines of chronic heart failure (CHF) do not recommend the use of oral anticoagulants (OAC) or antiplatelet therapy (APT). We performed a post-hoc analysis to evaluate the effect of the use of anti-thrombotic therapy with APT and OAC. PATIENTS AND METHODS: We examined 427

The Discovery of HD 37605c and a Dispositive Null Detection of Transits of HD 37605b

DEFF Research Database (Denmark)

Xuesong Wang, Sharon; Wright, Jason T.; Cochran, William

2012-01-01

the predicted ephemeris, we performed a transit search for HD 37605b with the photometric data taken by the T12 0.8-m Automatic Photoelectric Telescope (APT) and the Microvariability and Oscillations of Stars (MOST) satellite. Though the APT photometry did not capture the transit window, it characterized...

Superparamagnetic bead interactions with functionalized surfaces characterized by an immunomicroarray

DEFF Research Database (Denmark)

Skottrup, Peter Durand; Hansen, Mikkel Fougt; Moresco, Jacob Lange

2010-01-01

optimized Polyethylene glycol-based surfaces with different end groups on the anchor molecule, 2,4,6-trichloro-1,3,5-triazine (TsT), were synthesized and compared with the standard (3-aminopropyl)triethoxysilane (APTS)/glutaraldehyde chemistry APTS/glutaraldehyde, directly linked TsT and bare H2O2-activated...

R1 correction in amide proton transfer imaging: indication of the influence of transcytolemmal water exchange on CEST measurements.

Science.gov (United States)

Li, Hua; Li, Ke; Zhang, Xiao-Yong; Jiang, Xiaoyu; Zu, Zhongliang; Zaiss, Moritz; Gochberg, Daniel F; Gore, John C; Xu, Junzhong

2015-12-01

Amide proton transfer (APT) imaging may potentially detect mobile proteins/peptides non-invasively in vivo, but its specificity may be reduced by contamination from other confounding effects such as asymmetry of non-specific magnetization transfer (MT) effects and spin-lattice relaxation with rate R1 (=1/T1). Previously reported spillover, MT and R1 correction methods were based on a two-pool model, in which the existence of multiple water compartments with heterogeneous relaxation properties in real tissues was ignored. Such simple models may not adequately represent real tissues, and thus such corrections may be unreliable. The current study investigated the effectiveness and accuracy of correcting for R1 in APT imaging via simulations and in vivo experiments using tumor-bearing rats subjected to serial injections of Gd-DTPA that produced different tissue R1 values in regions of blood-brain-barrier breakdown. The results suggest that conventional measurements of APT contrast (such as APT* and MTRasym ) may be significantly contaminated by R1 variations, while the R1 -corrected metric AREX* was found to be relatively unaffected by R1 changes over a broad range (0.4-1 Hz). Our results confirm the importance of correcting for spin-lattice relaxation effects in quantitative APT imaging, and demonstrate the reliability of using the observed tissue R1 for corrections to obtain more specific and accurate measurements of APT contrast in vivo. The results also indicate that, due to relatively fast transcytolemmal water exchange, the influence of intra- and extracellular water compartments on CEST measurements with seconds long saturation time may be ignored in tumors. Copyright © 2015 John Wiley & Sons, Ltd.

Towards quantitative three-dimensional characterisation of InAs quantum dots

DEFF Research Database (Denmark)

Kadkhodazadeh, Shima; Semenova, Elizaveta; Kuznetsova, Nadezda

2011-01-01

the applicability of both high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) tomography and atom probe tomography (APT) to the study of surface and buried InAs/InGaAsP QDs grown by metal organic vapour phase epitaxy (MOVPE). Electron tomography was carried out in an FEI Titan TEM...... to their suitability for electron tomography, these specimens can be used for APT, for which needle-shaped specimens with sharp tips (narrower than 100 nm) are required. Our ongoing experiments involve the application of both HAADF STEM tomography and APT to the same QD, in order to better understand its morphology...

Teoría de precios de arbitraje. Evidencia empírica para Colombia a través de redes neuronales

Directory of Open Access Journals (Sweden)

Charle Londoño

2011-07-01

Full Text Available Esta investigación utiliza una red neuronal multicapa para relacionar el Índice General de Bolsa de Valores de Colombia (IGBC con fundamentales macroeconómicos y variables financieras. Proponemos dos modelos: un modelo APT (fundamentales macroeconómicos y un modelo APT modificado (fundamentales macroeconómicos + indicador de las bolsas del mundo; de acuerdo a nuestro análisis el APT tradicional se ajusta mejor para predecir el mercado de valores Colombiano. Los resultados confirman que las redes neuronales artificiales (ANN son más efectivas que los modelos estadísticos tradicionales por su capacidad explicativa y precisión.

Development and Validation of a New RP-HPLC Method for the ...

African Journals Online (AJOL)

Erah

cytotoxic chemotherapeutic agents, such as cisplatin, via central actions. Animal and human positron emission tomography (PET) studies with APT have shown that it crosses the blood brain barrier and occupies brain NK 1 receptors [2]. Animal and human studies show that APT augments the antiemetic activity of the 5-HT3.

Adsorption of C.I. Reactive Red 228 and Congo Red dye from aqueous solution by amino-functionalized Fe3O4 particles: kinetics, equilibrium, and thermodynamics.

Science.gov (United States)

Yan, Ting-guo; Wang, Li-Juan

2014-01-01

A magnetic adsorbent was synthesized by γ-aminopropyltriethoxysilane (APTES) modification of Fe(3)O(4) particles using a two-step process. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and vibration sample magnetometry were used to characterize the obtained magnetic adsorbent. EDS and XPS showed that APTES polymer was successfully introduced onto the as-prepared Fe(3)O(4)/APTES particle surfaces. The saturation magnetization of the magnetic adsorbent was around 65 emu g(-1), which indicated that the dye can be removed fast and efficiently from aqueous solution with an external magnetic field. The maximum adsorption capacities of Fe(3)O(4)/APTES for C.I. Reactive Red 228 (RR 228) and Congo Red (CR) were 51.4 and 118.8 mg g(-1), respectively. The adsorption of C.I. Reactive Red 228 (RR 228) and Congo Red (CR) on Fe(3)O(4)/APTES particles corresponded well to the Langmuir model and the Freundlich model, respectively. The adsorption processes for RR 228 and CR followed the pseudo-second-order model. The Boyd's film-diffusion model showed that film diffusion also played a major role in the studied adsorption processes for both dyes. Thermodynamic study indicated that both of the adsorption processes of the two dyes are spontaneous exothermic.

Targeted inhibition of αvβ3 integrin with an RNA aptamer impairs endothelial cell growth and survival

International Nuclear Information System (INIS)

Mi Jing; Zhang Xiuwu; Giangrande, Paloma H.; McNamara, James O.; Nimjee, Shahid M.; Sarraf-Yazdi, Shiva; Sullenger, Bruce A.; Clary, Bryan M.

2005-01-01

αvβ3 integrin is a crucial factor involved in a variety of physiological processes, such as cell growth and migration, tumor invasion and metastasis, angiogenesis, and wound healing. αvβ3 integrin exerts its effect by regulating endothelial cell (EC) migration, proliferation, and survival. Inhibiting the function of αvβ3 integrin, therefore, represents a potential anti-cancer, anti-thrombotic, and anti-inflammatory strategy. In this study, we tested an RNA aptamer, Apt-αvβ3 that binds recombinant αvβ3 integrin, for its ability to bind endogenous αvβ3 integrin on the surface of cells in culture and to subsequently affect cellular response. Our data illustrate that Apt-αvβ3 binds αvβ3 integrin expressed on the surface of live HUVECs. This interaction significantly decreases both basal and PDGF-induced cell proliferation as well as inhibition of cell adhesion. Apt-αvβ3 can also reduce PDGF-stimulated tube formation and increase HUVEC apoptosis through inhibition of FAK phosphorylation pathway. Our results demonstrate that by binding to its target, Apt-αvβ3 can efficiently inhibit human EC proliferation and survival, resulting in reduced angiogenesis. It predicts that Apt-αvβ3 could become useful in both tumor imaging and the treatment of tumor growth, atherosclerosis, thrombosis, and inflammation

Techniques for intense-proton-beam profile measurements

International Nuclear Information System (INIS)

Gilpatrick, J.D.

1998-01-01

In a collaborative effort with industry and several national laboratories, the Accelerator Production of Tritium (APT) facility and the Spallation Neutron Source (SNS) linac are presently being designed and developed at Los Alamos National Laboratory (LANL). The APT facility is planned to accelerate a 100-mA H + cw beam to 1.7 GeV and the SNS linac is planned to accelerate a 1- to 4-mA-average, H - , pulsed-beam to 1 GeV. With typical rms beam widths of 1- to 3-mm throughout much of these accelerators, the maximum average-power densities of these beams are expected to be approximately 30- and 1-MW-per-square millimeter, respectively. Such power densities are too large to use standard interceptive techniques typically used for acquisition of beam profile information. This paper summarizes the specific requirements for the beam profile measurements to be used in the APT, SNS, and the Low Energy Development Accelerator (LEDA)--a facility to verify the operation of the first 20-MeV section of APT. This paper also discusses the variety of profile measurement choices discussed at a recent high-average-current beam profile workshop held in Santa Fe, NM, and will present the present state of the design for the beam profile measurements planned for APT, SNS, and LEDA

Advanced Pediatric Brain Imaging Research and Training Program

Science.gov (United States)

2012-10-01

contrast, diffusion-weighted techniques, and MR spectroscopy (single voxel, multivoxel, PEPSI ). Mechanisms of recovery include application of the...key methods to build academic portfolios, understand the APT process and market their academic advancement Faculty Development: 103...APT process and market their academic advancement Faculty Development: 104 Leadership Faculty Development: Enhancing Team Effectiveness

Twenty-four-Hour Measurement of Intraocular Pressure in Guinea Pigs (Cavia porcellus).

Science.gov (United States)

Ansari-Mood, Maneli; Mehdi-Rajaei, Seyed; Sadjadi, Reza; Selk-Ghaffari, Masoud; Williams, David L

2016-01-01

The objective of this study was to measure intraocular pressure (IOP) in intact, healthy guinea pigs (15 male, 15 female) every 2 h for a 24-h period. First, IOP was measured by using rebound tonometry (RBT). After a 1-min rest period, 0.5% proparacaine ophthalmic solution, a topical anesthetic, was applied to both eyes; 4 min after anesthetic instillation, IOP was measured by using applanation tonometry (APT). The IOP was lower during the light period (0700 to 1900) than during the dark phase (2000 to 0600). The lowest IOP by both RBT and APT (3.68 and 13.37 mm Hg, respectively) occurred at 0700, whereas maximal IOP occurred at 2300 for RBT (8.12 mm Hg) but at 2100 for APT (20.62 mm Hg). No significant differences in IOP between the left and right eyes or between RBT and APT were noted. In addition, daily variations in the IOP of guinea pigs seem to be independent of sex and body weight. The results of this study may be beneficial in the diagnosis and observation of glaucoma in guinea pigs.

Streamlining Appointment, Promotion, and Tenure Procedures to Promote Early-Career Faculty Success.

Science.gov (United States)

Smith, Shannon B; Hollerbach, Ann; Donato, Annemarie Sipkes; Edlund, Barbara J; Atz, Teresa; Kelechi, Teresa J

2016-01-01

A critical component of the progression of a successful academic career is being promoted in rank. Early-career faculty are required to have an understanding of appointment, promotion, and tenure (APT) guidelines, but many factors often impede this understanding, thwarting a smooth and planned promotion pathway for professional advancement. This article outlines the steps taken by an APT committee to improve the promotion process from instructor to assistant professor. Six sigma's DMAIC improvement model was selected as the guiding operational framework to remove variation in the promotion process. After faculty handbook revisions were made, several checklists developed, and a process review rubric was implemented; recently promoted faculty were surveyed on satisfaction with the process. Faculty opinions captured in the survey suggest increased transparency in the process and perceived support offered by the APT committee. Positive outcomes include a strengthened faculty support framework, streamlined promotion processes, and improved faculty satisfaction. Changes to the APT processes resulted in an unambiguous and standardized pathway for successful promotion. Copyright © 2016 Elsevier Inc. All rights reserved.

Modified surface of titanium dioxide nanoparticles-based biosensor for DNA detection

Science.gov (United States)

Nadzirah, Sh.; Hashim, U.; Rusop, M.

2018-05-01

A new technique was used to develop a simple and selective picoammeter DNA biosensor for identification of E. coli O157:H7. This biosensor was fabricated from titanium dioxide nanoparticles that was synthesized by sol-gel method and spin-coated on silicon dioxide substrate via spinner. 3-Aminopropyl triethoxy silane (APTES) was used to modify the surface of TiO2. Simple surface modification approach has been applied; which is single dropping of APTES onto the TiO2 nanoparticles surface. Carboxyl modified probe DNA has been bind onto the surface of APTES/TiO2 without any amplifier element. Electrical signal has been used as the indicator to differentiate each step (surface modification of TiO2 and probe DNA immobilization). The I-V measurements indicate extremely low current (pico-ampere) flow through the device which is 2.8138E-10 A for pure TiO2 nanoparticles, 2.8124E-10 A after APTES modification and 3.5949E-10 A after probe DNA immobilization.

Aggressive pituitary tumours and carcinomas: two sides of the same coin?

Science.gov (United States)

Trouillas, Jacqueline; Burman, Pia; McCormack, Ann; Petersenn, Stephan; Popovic, Vera; Dekkers, Olaf; Raverot, Gerald

2018-06-01

The European Society of Endocrinology (ESE) survey reported on the largest cohort of 125 aggressive pituitary tumours (APT) and 40 pituitary carcinomas (PC). Whilst the survey focused on treatment effectiveness, all pathological data were not explored in detail. Here, we comment on some interesting pathological findings, notably the difference between APT and PC. © 2018 European Society of Endocrinology.

Oxygen uptake and body composition after aquatic physical training in women with fibromyalgia: a randomized controlled trial.

Science.gov (United States)

Andrade, Carolina P; Zamunér, Antonio R; Forti, Meire; França, Thalita F; Tamburús, Nayara Y; Silva, Ester

2017-10-01

Aquatic physical training (APT) has been strongly recommended to improve symptoms in fibromyalgia syndrome (FMS). However, its effects on body composition and whether lean body mass (LBM) directly influences the aerobic functional capacity of this population are still not clear. To investigate whether APT can help improve body composition and increase the aerobic functional capacity in women with FMS, and whether oxygen uptake (VO2) related to LBM can better quantify the functional capacity of this population. Randomized controlled trial. The Federal University of São Carlos, São Paulo, Brazil. Fifty-four women with FMS were randomly assigned to trained group (TG, N.=27) or control group (CG, N.=27). All women underwent cardiopulmonary exercise test (CPET) to assess oxygen consumption at ventilatory anaerobic threshold (VAT) and at peak exercise, and also to assess body composition. The TG was submitted to APT program, held twice a week for 16 weeks. The exercise intensity was adapted throughout the sessions in order to keep heart rate and ratings of perceived exertion achieved at VAT. After APT, body composition was not significantly different between groups (TG and CG). In VAT only TG showed increased VO2 related to LBM, since in peak CPET, VO2 in absolute units, VO2 related to total body mass (TBM), VO2 related to LBM and power showed significant differences. Significant difference between VO2 related to TBM and VO2 related to baseline LBM and after 16 weeks of follow-up, both in VAT as in peak CPET in both groups. Significant difference between VO2 related to TBM and VO2 related to LBM at VAT and at peak CPET in both groups at baseline and after 16 weeks of follow-up was observed. APT with standardized intensities did not cause significant changes in body composition, but was effective in promoting increased VO2 at peak CPET in women with FMS. However, VO2 related to LBM more accurately reflected changes in aerobic functional capacity at VAT level after to

Aptamer-conjugated PEGylated quantum dots targeting epidermal growth factor receptor variant III for fluorescence imaging of glioma.

Science.gov (United States)

Tang, Jiaze; Huang, Ning; Zhang, Xiang; Zhou, Tao; Tan, Ying; Pi, Jiangli; Pi, Li; Cheng, Si; Zheng, Huzhi; Cheng, Yuan

2017-01-01

The extent of resection is a significant prognostic factor in glioma patients. However, the maximum safe resection level is difficult to determine due to the inherent infiltrative character of tumors. Recently, fluorescence-guided surgery has emerged as a new technique that allows safe resection of glioma. In this study, we constructed a new kind of quantum dot (QD)-labeled aptamer (QD-Apt) nanoprobe by conjugating aptamer 32 (A32) to the QDs surface, which can specially bind to the tumors. A32 is a single-stranded DNA capable of binding to the epidermal growth factor receptor variant III (EGFRvIII) specially distributed on the surface of glioma cells. To detect the expression of EGFRvIII in human brain tissues, 120 specimens, including 110 glioma tissues and 10 normal brain tissues, were examined by immunohistochemistry, and the results showed that the rate of positive expression of EGFRvIII in the glioma tissues was 41.82%, and 0.00% in normal brain tissues. Besides, the physiochemical properties of QD-Apt nanoparticles (NPs) were thoroughly characterized. Biocompatibility of the NPs was evaluated, and the results suggested that the QD-Apt was nontoxic in vivo and vitro. Furthermore, the use of the QD-Apt in labeling glioma cell lines and human brain glioma tissues, and target gliomas in situ was also investigated. We found that not only could QD-Apt specially bind to the U87-EGFRvIII glioma cells but also bind to human glioma tissues in vitro. Fluorescence imaging in vivo with orthotopic glioma model mice bearing U87-EGFRvIII showed that QD-Apt could penetrate the blood-brain barrier and then selectively accumulate in the tumors through binding to EGFRvIII, and consequently, generate a strong fluorescence, which contributed to the margins of gliomas that were visualized clearly, and thus, help the surgeons realize the maximum safe resection of glioma. In addition, QD-Apt can also be applied in preoperative diagnosis and postoperative examination of glioma

Contact Dermatitis Associated With Skin Cleansers: Retrospective Analysis of North American Contact Dermatitis Group Data 2000-2014.

Science.gov (United States)

Warshaw, Erin M; Goodier, Molly C; DeKoven, Joel G; Maibach, Howard I; Taylor, James S; Sasseville, Denis; Belsito, Donald V; Fowler, Joseph F; Fransway, Anthony F; DeLeo, Vincent A; Marks, James G; Pratt, Melanie D; Mathias, Toby; Zirwas, Matthew J; Zug, Kathryn A

There is limited information regarding contact dermatitis (CD) associated with skin cleansers (SCs). The aim of the study was to evaluate the prevalence of allergic patch test (APT) reactions and irritant CD (ICD) associated with SCs. A retrospective cross-sectional analysis was performed using North American Contact Dermatitis Group data, 2000-2014. Of 32,945 tested patients, 1069 (3.24%) had either APT reaction or ICD associated with SCs. Of these, 692 (64.7%) had APT reaction only, 350 (32.7%) had ICD only, and 27 (2.5%) had both. Individuals with APT reaction and/or ICD were more likely to have occupationally related skin disease (relative risk [RR] = 3.8 [95% confidence interval {CI} = 3.3-4.5] for APT reaction and 10.0 [95% CI = 8.2-12.2] for ICD, respectively, P dermatitis (RR = 1.3 [95% CI = 1.1-1.6], P ≤ 0.001). Irritant CD was strongly associated with hand dermatitis (RR = 6.2 [95% CI = 5.2-7.3], P < 0.0001). More than 50 allergens were associated with SCs including quaternium-15 (11.2%), cocamidopropyl betaine (9.5%), methylchloroisothiazolinone/methylisothiazolinone (8.4%), coconut diethanolamide (7.9%), fragrance mix I (7.7%), Myroxylon pereirae (5.9%), 4-chloro-3,5-xylenol (5.8%), amidoamine (5.5%), and formaldehyde (4.4%). Many allergens, especially preservatives and surfactants, were associated with SCs. Most cases involved the hands and were occupationally related.

Development of electrochemical immunosensors based on different serum antibody immobilization methods for detection of Japanese encephalitis virus

International Nuclear Information System (INIS)

Tran, Quang Huy; Hanh Nguyen, Thi Hong; Phan, Thi Nga; Mai, Anh Tuan; Nguyen, Thi Thuy; Vu, Quang Khue

2012-01-01

This paper describes the development of electrochemical immunosensors based on human serum antibodies with different immobilization methods for detection of Japanese encephalitis virus (JEV). Human serum containing anti-JEV antibodies was used to immobilize onto the surface of silanized interdigitated electrodes by four methods: direct adsorption (APTES-serum), covalent binding with a cross linker of glutaraldehyde (APTES-GA-serum), covalent binding with a cross linker of glutaraldehyde combined with anti-human IgG (APTES-GA-anti-HIgG-serum) and covalent binding with a cross linker of glutaraldehyde combined with a bioaffinity of protein A (APTES-GA-PrA-serum). Atomic force microscopy was used to verify surface characteristics of the interdigitated electrodes before and after treatment with serum antibodies. The output signal of the immunosensors was measured by the change of conductivity resulting from the specific binding of JEV antigens and serum antibodies immobilized on the electrodes, with the help of horseradish peroxidase (HRP)-labeled secondary antibody against JEV. The results showed that the APTES-GA-PrA-serum method provided the highest signal of the electrochemical immunosensor for detection of JEV antigens, with the linear range from 25 ng ml −1 to 1 μg ml −1 , and the limit of detection was about 10 ng ml −1 . This study shows a potential development of novel electrochemical immunosensors applied for virus detection in clinical samples in case of possible outbreaks

APT 3He target/blanket. Topical report

International Nuclear Information System (INIS)

1995-03-01

The 3 He target/blanket (T/B) preconceptual design for the 3/8-Goal facility is based on a 1000-MeV, 200-mA accelerator to produce a high-intensity proton beam that is expanded and then strikes one of two T/B modules. Each module consists of a centralized neutron source made of tungsten and lead, a proton beam backstop region made of zirconium and lead, and a moderator made of D 2 O. Helium-3 gas is circulated through the neutron source region and the blanket to create tritium through neutron capture. The gas is continually processed to extract the tritium with an online separation process

APT characterization of high nickel RPV steels

International Nuclear Information System (INIS)

Miller, M.K.; Russell, K.F

2004-01-01

Full text: The microstructures of several high nickel content pressure vessel steels have been characterized by atom probe tomography. The purposes of this study were to investigate the influence of high nickel levels on the response to neutron irradiation of high and low copper pressure vessel steels and to establish whether any additional phases were present after neutron irradiation. The nickel levels in these steels were at least twice that typically found in Western pressure vessel steels. Two different types of pressure vessel steels with low and high copper contents were selected for this study. The first set of alloys was low copper (∼0.05% Cu) base (15Ch2NMFAA) and weld (12Ch2N2MAA) materials used in a VVER-1000 reactor. The composition of the lower nickel VVER-1000 base material was Fe- 0.17 wt% C, 0.30% Si, 0.46% Mn, 2.2% Cr, 1.26% Ni, 0.05% Cu, 0.01% S, 0.008% P, 0.10% V and 0.50% Mo. The composition of the higher nickel VVER-1000 weld material was Fe- 0.06 wt % C, 0.33% Si, 0.80% Mn, 1.8% Cr, 1.78% Ni, 0.07% Cu, 0.009% S, 0.005% P, and 0.63% Mo. The VVER-1000 steels were irradiated in the HSSI Program's irradiation facilities at the University of Michigan, Ford Nuclear Reactor at a temperature of 288 o C for 2,137 h at an average flux of 7.08 x 10 11 cm 2 s -1 for a fluence of 5.45 x 10 18 n cm -2 (E >1 MeV) and for 5,340 h at an average flux of 4.33 x 10 11 cm -2 s -1 for a fluence of 8.32 x 10 1 28 n cm -2 (E >1 MeV). Therefore, the total fluence was 1.38 x 10 19 n cm -2 (E >1 MeV). The second type of pressure vessel steel was a high copper (0.20% Cu) weld from the Palisades reactor. The average composition of the Palisades weld was Fe- 0.11 wt% C, 0.18% Si, 1.27% Mn, 0.04% Cr, 1.20% Ni, 0.20% Cu, 0.017% S, 0.014% P, 0.003% V and 0.55% Mn. The Palisades weld, designated weldment 'B' from weld heat 34B009, was irradiated at a temperature of 288 o C and a flux of ∼7 x 10 11 cm -2 s -1 to a fast fluence of 1.4 x 10 19 n cm -2 (E >1 MeV). These three alloys were characterized with the Oak Ridge National Laboratory local electrode atom probe. Atom probe tomography revealed nickel-, manganese-, and silicon-enriched precipitates in both the VVER 1000 base and weld materials after neutron irradiation. A high number density of copper-, nickel-, manganese-, silicon- and phosphorus-enriched precipitates were observed in the Palisades weld after neutron irradiation. Atom probe tomography also revealed high levels of phosphorus segregation to the dislocations in all three materials. Full details of the differences in the size, number density and composition of the precipitates in the three materials will be presented. (author)

APT: Action localization Proposals from dense Trajectories

NARCIS (Netherlands)

van Gemert, J.C.; Jain, M.; Gati, E.; Snoek, C.G.M.; Xie, X.; Jones, M.W.; Tam, G.K.L.

2015-01-01

This paper is on action localization in video with the aid of spatio-temporal proposals. To alleviate the computational expensive video segmentation step of existing proposals, we propose bypassing the segmentations completely by generating proposals directly from the dense trajectories used to

Using crowdsourcing to examine behavioral economic measures of alcohol value and proportionate alcohol reinforcement.

Science.gov (United States)

Morris, Vanessa; Amlung, Michael; Kaplan, Brent A; Reed, Derek D; Petker, Tashia; MacKillop, James

2017-08-01

Online crowdsourcing websites such as Amazon's Mechanical Turk (MTurk) are increasingly being used in addictions research. However, there is a relative paucity of such research examining the validity of administering behavioral economic alcohol-related measures, via an online crowdsourcing platform. This study sought to validate an alcohol purchase task (APT) for assessing demand and a questionnaire measure of proportionate alcohol reinforcement, using an online sample of participants recruited via MTurk. Participants (N = 865, 59% female) were recruited via MTurk to complete the APT, proportionate alcohol reinforcement questionnaire, Alcohol Use Disorders Identification Test (AUDIT), and demographics. Responses on the APT were highly systematic (crowdsourcing websites for investigating behavioral economic determinants of alcohol misuse. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Atom probe tomography simulations and density functional theory calculations of bonding energies in Cu3Au

KAUST Repository

Boll, Torben

2012-10-01

In this article the Cu-Au binding energy in Cu3Au is determined by comparing experimental atom probe tomography (APT) results to simulations. The resulting bonding energy is supported by density functional theory calculations. The APT simulations are based on the Müller-Schottky equation, which is modified to include different atomic neighborhoods and their characteristic bonds. The local environment is considered up to the fifth next nearest neighbors. To compare the experimental with simulated APT data, the AtomVicinity algorithm, which provides statistical information about the positions of the neighboring atoms, is applied. The quality of this information is influenced by the field evaporation behavior of the different species, which is connected to the bonding energies. © Microscopy Society of America 2012.

The accurate particle tracer code

Science.gov (United States)

Wang, Yulei; Liu, Jian; Qin, Hong; Yu, Zhi; Yao, Yicun

2017-11-01

The Accurate Particle Tracer (APT) code is designed for systematic large-scale applications of geometric algorithms for particle dynamical simulations. Based on a large variety of advanced geometric algorithms, APT possesses long-term numerical accuracy and stability, which are critical for solving multi-scale and nonlinear problems. To provide a flexible and convenient I/O interface, the libraries of Lua and Hdf5 are used. Following a three-step procedure, users can efficiently extend the libraries of electromagnetic configurations, external non-electromagnetic forces, particle pushers, and initialization approaches by use of the extendible module. APT has been used in simulations of key physical problems, such as runaway electrons in tokamaks and energetic particles in Van Allen belt. As an important realization, the APT-SW version has been successfully distributed on the world's fastest computer, the Sunway TaihuLight supercomputer, by supporting master-slave architecture of Sunway many-core processors. Based on large-scale simulations of a runaway beam under parameters of the ITER tokamak, it is revealed that the magnetic ripple field can disperse the pitch-angle distribution significantly and improve the confinement of energetic runaway beam on the same time.

A saxitoxin-binding aptamer with higher affinity and inhibitory activity optimized by rational site-directed mutagenesis and truncation.

Science.gov (United States)

Zheng, X; Hu, B; Gao, S X; Liu, D J; Sun, M J; Jiao, B H; Wang, L H

2015-07-01

Saxitoxin (STX), a member of the family of paralytic shellfish poisoning toxins, poses toxicological and ecotoxicological risks. To develop an analytical recognition element for STX, a DNA aptamer (APT(STX1)) was previously discovered via an iterative process known as Systematic Evolution of Ligands by Exponential Enrichment (SELEX) by Handy et al. Our study focused on generating an improved aptamer based on APT(STX1) through rational site-directed mutation and truncation. In this study, we generated the aptamer, M-30f, with a 30-fold higher affinity for STX compared with APT(STX1). The Kd value for M-30f was 133 nM, which was calculated by Bio-Layer Interferometry. After optimization, we detected and compared the interaction of STX with aptamers (APT(STX1) or M-30f) through several techniques (ELISA, cell bioassay, and mouse bioassay). Both aptamers' STX-binding ability was demonstrated in all three methods. Moreover, M-30f performs better than its parent sequence with higher suppressive activity against STX. As a molecular recognition element, M-30f has good prospects for practical application. Copyright © 2015 Elsevier Ltd. All rights reserved.

Characterization of grain boundaries in Cu(In,Ga)Se{sub 2} by atom probe tomography

Energy Technology Data Exchange (ETDEWEB)

Schwarz, Torsten; Cojocaru-Miredin, Oana; Choi, Pyuck-Pa; Raabe, Dierk [Max-Planck Institute for Iron Research GmbH, Duesseldorf (Germany); Wuerz, Roland [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany)

2012-07-01

Solar cells based on the compound semiconductor Cu(In,Ga)Se{sub 2} (CIGS) as absorber material exhibit the highest efficiency among all thin-film solar cells. This is surprising high in view of the polycrystalline defect-rich structure of the CIGS absorber films. The high efficiency has been commonly ascribed to the diffusion of alkali metal atoms from the soda-lime glass substrate into the CIGS layer, which can render the grain boundaries (GB) electrically inactive. However, the exact mechanisms of how these impurities enhance the cell efficiency are yet to be clarified. As a step towards a better understanding of CIGS solar cells, we have analyzed the composition of solar-grade CIGS layers at the atomic-scale by using pulsed laser Atom Probe Tomography (APT). To perform APT analyses on selected GBs site-specific sample preparation was carried out using the Focused Ion Beam lift-out technique. In addition, Electron Back Scattered Diffraction was performed to characterize the structure and misorientation of selected GBs. Using APT, segregation of impurities at the GBs was directly observed. APT data of various types of GBs are presented and discussed with respect to the possible effects on the cell efficiency.

Atom probe tomography of Ni-base superalloys Allvac 718Plus and Alloy 718

Energy Technology Data Exchange (ETDEWEB)

Viskari, L., E-mail: viskari@chalmers.se [Chalmers University of Technology, Gothenburg (Sweden); Stiller, K. [Chalmers University of Technology, Gothenburg (Sweden)

2011-05-15

Atom probe tomography (APT) allows near atomic scale compositional- and morphological studies of, e.g. matrix, precipitates and interfaces in a wide range of materials. In this work two Ni-base superalloys with similar compositions, Alloy 718 and its derivative Allvac 718Plus, are subject for investigation with special emphasis on the latter alloy. The structural and chemical nuances of these alloys are important for their properties. Of special interest are grain boundaries as their structure and chemistry are important for the materials' ability to resist rapid environmentally induced crack propagation. APT has proved to be suitable for analyses of these types of alloys using voltage pulsed APT. However, for investigations of specimens containing grain boundaries and other interfaces the risk for early specimen fracture is high. Analyses using laser pulsing impose lower electrical field on the specimen thereby significantly increasing the success rate of investigations. Here, the effect of laser pulsing was studied and the derived appropriate acquisition parameters were then applied for microstructural studies, from which initial results are shown. Furthermore, the influence of the higher evaporation field experienced by the hardening {gamma}' Ni{sub 3}(Al,Nb) precipitates on the obtained results is discussed. -- Research highlights: {yields} Laser pulsed APT is shown to be a good method for analysis of Ni-based superalloys. {yields} The evaporation field is shown to be different for different phases which affects reconstructions. {yields} B and P are shown to segregate to grain boundaries. {yields} Initial results of {delta}-phase analysed by APT are shown.

Heavy vehicle simulator operations: protocol for instrumentation, data collection and data storage - 2nd draft

CSIR Research Space (South Africa)

Jones, DJ

2002-09-01

Full Text Available The instrumentation used is discussed under the relevant sections. Keywords: Accelerated pavement testing (APT), Heavy Vehicle Simulator (HVS) Proposals for implementation: Follow protocol in all future HVS testing. Update as required... future HVS testing. The protocol discusses staffing, site selection and establishment, and data collection, analysis and storage. 1.2. Accelerated Pavement Testing Accelerated Pavement Testing (APT) can be described as a controlled application...

The Harvard Automated Phone Task: new performance-based activities of daily living tests for early Alzheimer's disease.

Science.gov (United States)

Marshall, Gad A; Dekhtyar, Maria; Bruno, Jonathan M; Jethwani, Kamal; Amariglio, Rebecca E; Johnson, Keith A; Sperling, Reisa A; Rentz, Dorene M

2015-12-01

Impairment in activities of daily living is a major burden for Alzheimer's disease dementia patients and caregivers. Multiple subjective scales and a few performance-based instruments have been validated and proven to be reliable in measuring instrumental activities of daily living in Alzheimer's disease dementia but less so in amnestic mild cognitive impairment and preclinical Alzheimer's disease. To validate the Harvard Automated Phone Task, a new performance-based activities of daily living test for early Alzheimer's disease, which assesses high level tasks that challenge seniors in daily life. In a cross-sectional study, the Harvard Automated Phone Task was associated with demographics and cognitive measures through univariate and multivariate analyses; ability to discriminate across diagnostic groups was assessed; test-retest reliability with the same and alternate versions was assessed in a subset of participants; and the relationship with regional cortical thickness was assessed in a subset of participants. Academic clinical research center. One hundred and eighty two participants were recruited from the community (127 clinically normal elderly and 45 young normal participants) and memory disorders clinics at Brigham and Women's Hospital and Massachusetts General Hospital (10 participants with mild cognitive impairment). As part of the Harvard Automated Phone Task, participants navigated an interactive voice response system to refill a prescription (APT-Script), select a new primary care physician (APT-PCP), and make a bank account transfer and payment (APT-Bank). The 3 tasks were scored based on time, errors, and repetitions from which composite z-scores were derived, as well as a separate report of correct completion of the task. We found that the Harvard Automated Phone Task discriminated well between diagnostic groups (APT-Script: p=0.002; APT-PCP: pHarvard Automated Phone Task and executive function (APT-PCP: pHarvard Automated Phone Task, which

The Harvard Automated Phone Task: new performance-based activities of daily living tests for early Alzheimer’s disease

Science.gov (United States)

Marshall, Gad A.; Dekhtyar, Maria; Bruno, Jonathan M.; Jethwani, Kamal; Amariglio, Rebecca E.; Johnson, Keith A.; Sperling, Reisa A.; Rentz, Dorene M.

2015-01-01

Background Impairment in activities of daily living is a major burden for Alzheimer’s disease dementia patients and caregivers. Multiple subjective scales and a few performance-based instruments have been validated and proven to be reliable in measuring instrumental activities of daily living in Alzheimer’s disease dementia but less so in amnestic mild cognitive impairment and preclinical Alzheimer’s disease. Objective To validate the Harvard Automated Phone Task, a new performance-based activities of daily living test for early Alzheimer’s disease, which assesses high level tasks that challenge seniors in daily life. Design In a cross-sectional study, the Harvard Automated Phone Task was associated with demographics and cognitive measures through univariate and multivariate analyses; ability to discriminate across diagnostic groups was assessed; test-retest reliability with the same and alternate versions was assessed in a subset of participants; and the relationship with regional cortical thickness was assessed in a subset of participants. Setting Academic clinical research center. Participants One hundred and eighty two participants were recruited from the community (127 clinically normal elderly and 45 young normal participants) and memory disorders clinics at Brigham and Women’s Hospital and Massachusetts General Hospital (10 participants with mild cognitive impairment). Measurements As part of the Harvard Automated Phone Task, participants navigated an interactive voice response system to refill a prescription (APT-Script), select a new primary care physician (APT-PCP), and make a bank account transfer and payment (APT-Bank). The 3 tasks were scored based on time, errors, and repetitions from which composite z-scores were derived, as well as a separate report of correct completion of the task. Results We found that the Harvard Automated Phone Task discriminated well between diagnostic groups (APT-Script: p=0.002; APT-PCP: pHarvard Automated Phone

Double targeting and aptamer-assisted controlled release delivery of epirubicin to cancer cells by aptamers-based dendrimer in vitro and in vivo.

Science.gov (United States)

Taghdisi, Seyed Mohammad; Danesh, Noor Mohammad; Ramezani, Mohammad; Lavaee, Parirokh; Jalalian, Seyed Hamid; Robati, Rezvan Yazdian; Abnous, Khalil

2016-05-01

Clinical use of epirubicin (Epi) in the treatment of cancer has been limited, due to its cardiotoxicity. Targeted delivery of chemotherapeutic agents could increase their efficacy and reduce their off-target effects. High drug loading and excellent stability of DNA dendrimers make these DNA nanostructures unique candidates for biological applications. In this study a modified and promoted dendrimer using three kinds of aptamers (MUC1, AS1411 and ATP aptamers) was designed for targeted delivery of Epi and its efficacy was evaluated in target cells including MCF-7 cells (breast cancer cell) and C26 cells (murine colon carcinoma cell). Aptamers (Apts)-Dendrimer-Epi complex formation was analyzed by fluorometric analysis and gel retardation assay. Release profiles of Epi from the designed complex were assessed at pHs 5.4 and 7.4. For MTT assay (cytotoxic study) MCF-7 and C26 cells (target cells) and CHO cells (Chinese hamster ovary cell, nontarget) were treated with Epi, Apts-Dendrimer-Epi complex and Apts-Dendrimer conjugate. Internalization was evaluated using flow cytometry analysis. Finally, the developed complex was used for inhibition of tumor growth in vivo. 25μM Epi was efficiently intercalated to 1μM dendrimer. Epi was released from the Apts-Dendrimer-Epi complex in a pH-sensitive manner (more release at pH 5.5). The results of flow cytometry analysis indicated that the designed complex was efficiently internalized into target cells, but not into control cells. The internalization data were confirmed by the results of MTT assay. Apts-Dendrimer-Epi complex had less cytotoxicity in CHO cells compared to Epi alone. The complex had more cytotoxicity in C26 and MCF-7 cells compared to Epi alone. Moreover, the Apts-Dendrimer-Epi complex could efficiently prohibit tumor growth in vivo. In conclusion, the designed targeted drug delivery system inherited characteristics of pH-dependent drug release, high drug loading and tumor targeting in vitro and in vivo

Atom-probe for FinFET dopant characterization

Energy Technology Data Exchange (ETDEWEB)

Kambham, A.K., E-mail: kambham@imec.be [K.U.Leuven, Instituut voor Kern-en Stralings fysika, Celestijnenlaan 200D, B-3001, Leuven (Belgium); IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Mody, J.; Gilbert, M.; Koelling, S.; Vandervorst, W. [K.U.Leuven, Instituut voor Kern-en Stralings fysika, Celestijnenlaan 200D, B-3001, Leuven (Belgium); IMEC, Kapeldreef 75, B-3001 Leuven (Belgium)

2011-05-15

With the continuous shrinking of transistors and advent of new transistor architectures to keep in pace with Moore's law and ITRS goals, there is a rising interest in multigate 3D-devices like FinFETs where the channel is surrounded by gates on multiple surfaces. The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions of the device. As a result there is a need for new metrology approach/technique to characterize quantitatively the dopant distribution in these devices with nanometer precision in 3D. In recent years, atom probe tomography (APT) has shown its ability to analyze semiconductor and thin insulator materials effectively with sub-nm resolution in 3D. In this paper we will discuss the methodology used to study FinFET-based structures using APT. Whereas challenges and solutions for sample preparation linked to the limited fin dimensions already have been reported before, we report here an approach to prepare fin structures for APT, which based on their processing history (trenches filled with Si) are in principle invisible in FIB and SEM. Hence alternative solutions in locating and positioning them on the APT-tip are presented. We also report on the use of the atom probe results on FinFETs to understand the role of different dopant implantation angles (10{sup o} and 45{sup o}) when attempting conformal doping of FinFETs and provide a quantitative comparison with alternative approaches such as 1D secondary ion mass spectrometry (SIMS) and theoretical model values. -- Research highlights: {yields} This paper provides the information on how to characterize the FinFET devices using atom probe tomography (APT). {yields} Importance of this work is to assess the performance of these devices at different processing conditions by extracting the compositional profiles. {yields} The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions

Atom-probe for FinFET dopant characterization

International Nuclear Information System (INIS)

Kambham, A.K.; Mody, J.; Gilbert, M.; Koelling, S.; Vandervorst, W.

2011-01-01

With the continuous shrinking of transistors and advent of new transistor architectures to keep in pace with Moore's law and ITRS goals, there is a rising interest in multigate 3D-devices like FinFETs where the channel is surrounded by gates on multiple surfaces. The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions of the device. As a result there is a need for new metrology approach/technique to characterize quantitatively the dopant distribution in these devices with nanometer precision in 3D. In recent years, atom probe tomography (APT) has shown its ability to analyze semiconductor and thin insulator materials effectively with sub-nm resolution in 3D. In this paper we will discuss the methodology used to study FinFET-based structures using APT. Whereas challenges and solutions for sample preparation linked to the limited fin dimensions already have been reported before, we report here an approach to prepare fin structures for APT, which based on their processing history (trenches filled with Si) are in principle invisible in FIB and SEM. Hence alternative solutions in locating and positioning them on the APT-tip are presented. We also report on the use of the atom probe results on FinFETs to understand the role of different dopant implantation angles (10 o and 45 o ) when attempting conformal doping of FinFETs and provide a quantitative comparison with alternative approaches such as 1D secondary ion mass spectrometry (SIMS) and theoretical model values. -- Research highlights: → This paper provides the information on how to characterize the FinFET devices using atom probe tomography (APT). → Importance of this work is to assess the performance of these devices at different processing conditions by extracting the compositional profiles. → The performance of these devices depends on the dimensions and the spatial distribution of dopants in source/drain regions. → In this publication we

Transparent and flexible conducting hybrid film combined with 3-Aminopropyltriethoxysilane-coated polymer and graphene

International Nuclear Information System (INIS)

Jung, Daesung; Ko, Yong-Hun; Cho, Jumi; Adhikari, Prashanta Dhoj; Lee, Su Il; Kim, Yooseok; Song, Wooseok; Jung, Min Wook; Jang, Sung Won; Lee, Seung Youb; An, Ki-Seok; Park, Chong-Yun

2015-01-01

A simple approach to fabricate graphene hybrid film consisted of Graphene/3-aminopropyltriethoxysilane (APTES)/polyethylene terephthalate (PET) is presented, using self-assembled monolayers (SAMs) for enhancement of conductivity. The SAMs of APTES was prepared on ultraviolet-ozone (UVO)-irradiated PET films via wet chemical technique. The density of APTES was saturated after UV treatment time of 1 h for PET films; the carrier density and the optical transmittance were 9.3 × 10 12 /cm 2 and 82% for pristine graphene and 1.16 × 10 13 /cm 2 and 86% for graphene hybrid films, respectively, and experienced at inflection point at 30 min in UV treatment time. This behavior can be explained by surface morphology transition due to coalescence or clustering of mobile and low-molecular-weight oxidized components of PET.

Efficiency of sugarcane bagasse-based sorbents for oil removal from engine washing wastewater.

Science.gov (United States)

Guilharduci, Viviane Vasques da Silva; Martelli, Patrícia Benedini; Gorgulho, Honória de Fátima

2017-01-01

This work evaluates the efficiency of sugarcane bagasse-based sorbents in the sorption of oil from engine washing wastewater. The sorbents were obtained from sugarcane bagasse in the natural form (SB-N) and modified with either acetic anhydride (SB-Acet) or 3-aminopropyltriethoxysilane (SB-APTS). The results showed that the sorption capacity of these materials decreased in the following order: SB-APTS > SB-N > SB-Acet. The superior oil sorption capacity observed for SB-APTS was attributed to the polar amino end groups in the silane structure, which acted to increase the hydrophilic character of the fibers. However, all the sorbents obtained in this study were able to clean a real sample of wastewater from engine washing, leading to significant reductions in suspended matter, sediment, anionic surfactants, and turbidity.

Analysing improvements to on-street public transport systems: a mesoscopic model approach

DEFF Research Database (Denmark)

Ingvardson, Jesper Bláfoss; Kornerup Jensen, Jonas; Nielsen, Otto Anker

2017-01-01

and other advanced public transport systems (APTS), the attractiveness of such systems depends heavily on their implementation. In the early planning stage it is advantageous to deploy simple and transparent models to evaluate possible ways of implementation. For this purpose, the present study develops...... headway time regularity and running time variability, i.e. taking into account waiting time and in-vehicle time. The approach was applied on a case study by assessing the effects of implementing segregated infrastructure and APTS elements, individually and in combination. The results showed...... that the reliability of on-street public transport operations mainly depends on APTS elements, and especially holding strategies, whereas pure infrastructure improvements induced travel time reductions. The results further suggested that synergy effects can be obtained by planning on-street public transport coherently...

Multivariate statistical analysis of atom probe tomography data

International Nuclear Information System (INIS)

Parish, Chad M.; Miller, Michael K.

2010-01-01

The application of spectrum imaging multivariate statistical analysis methods, specifically principal component analysis (PCA), to atom probe tomography (APT) data has been investigated. The mathematical method of analysis is described and the results for two example datasets are analyzed and presented. The first dataset is from the analysis of a PM 2000 Fe-Cr-Al-Ti steel containing two different ultrafine precipitate populations. PCA properly describes the matrix and precipitate phases in a simple and intuitive manner. A second APT example is from the analysis of an irradiated reactor pressure vessel steel. Fine, nm-scale Cu-enriched precipitates having a core-shell structure were identified and qualitatively described by PCA. Advantages, disadvantages, and future prospects for implementing these data analysis methodologies for APT datasets, particularly with regard to quantitative analysis, are also discussed.

Antibodies to phosphatidylserine/prothrombin complex as an additional diagnostic marker of APS?

Science.gov (United States)

Žigon, P; Čučnik, S; Ambrožič, A; Sodin Šemrl, S; Kveder, T; Božič, B

2012-06-01

Antiprothrombin antibodies can be measured by ELISA using either a prothrombin/phosphatidylserine complex (aPS/PT) or prothrombin alone (aPT) as antigen. We aimed to compare the clinical features of autoimmune patients with avidity of aPS/PT and determine the diagnostic efficiency of aPS/PT and aPT for assessing antiphospholipid syndrome (APS). aPS/PT were of low (n = 9), heterogeneous (n = 31) and high (n = 8) avidity out of 48 cases. None of the samples with low avidity were positive in aPT ELISA. Among patients with heterogeneous or high avidity aPS/PT, there was a significantly greater number of patients with APS as compared to patients with low avidity (38/39 vs. 7/9; p < 0.05). No SLE patients had high avidity antiprothrombin antibodies.

Nanoporous Polymeric Grating-Based Biosensors

KAUST Repository

Gao, Tieyu; Hsiao, Vincent; Zheng, Yue Bing; Huang, Tony Jun

2012-01-01

We demonstrate the utilization of an interferometrically created nanoporous polymeric gratings as a platform for biosensing applications. Aminopropyltriethoxysilane (APTES)-functionalized nanoporous polymeric gratings was fabricated by combining holographic interference patterning and APTES-functionalization of pre-polymer syrup. The successful detection of multiple biomolecules indicates that the biofunctionalized nanoporous polymeric gratings can act as biosensing platforms which are label-free, inexpensive, and applicable as high-throughput assays. Copyright © 2010 by ASME.

Accelerator production of tritium pollution prevention design assessment

International Nuclear Information System (INIS)

Reynolds, R.; Nowacki, P.; Sheetz, S.O.; Lanik, P.

1997-01-01

This Pollution Prevention Design Assessment (PPDA) provides data for cost-benefit analysis of the potential environmental impact of the APT, is an integral part of pollution prevention/waste minimization, and is required by DOE for any activity generating radioactive, hazardous, and mixed wastes. It will also better position the APT to meet future requirements, since it is anticipated that regulatory and other requirements will continue to become more restrictive and demanding

Nanoporous Polymeric Grating-Based Biosensors

KAUST Repository

Gao, Tieyu

2012-05-02

We demonstrate the utilization of an interferometrically created nanoporous polymeric gratings as a platform for biosensing applications. Aminopropyltriethoxysilane (APTES)-functionalized nanoporous polymeric gratings was fabricated by combining holographic interference patterning and APTES-functionalization of pre-polymer syrup. The successful detection of multiple biomolecules indicates that the biofunctionalized nanoporous polymeric gratings can act as biosensing platforms which are label-free, inexpensive, and applicable as high-throughput assays. Copyright © 2010 by ASME.

Accelerator production of tritium pollution prevention design assessment

Energy Technology Data Exchange (ETDEWEB)

Reynolds, R.; Nowacki, P.; Sheetz, S.O. [Westinghouse Savannah River Co., Aiken, SC (United States); Lanik, P. [Burns and Roe Engineering Inc. (United States)

1997-09-18

This Pollution Prevention Design Assessment (PPDA) provides data for cost-benefit analysis of the potential environmental impact of the APT, is an integral part of pollution prevention/waste minimization, and is required by DOE for any activity generating radioactive, hazardous, and mixed wastes. It will also better position the APT to meet future requirements, since it is anticipated that regulatory and other requirements will continue to become more restrictive and demanding.

Analytic perturbation theory in analyzing some QCD observables

International Nuclear Information System (INIS)

Shirkov, D.V.

2001-01-01

The paper is devoted to application of recently devised ghost-free Analytic Perturbation Theory (APT) for analysis of some QCD observables. We start with the discussion of the main problem of the perturbative QCD - ghost singularities and with the resume of this trouble solution within the APT. By a few examples in the various energy and momentum transfer regions (with the flavor number f = 3, 4 and 5) we demonstrate the effect of improved convergence of the APT modified perturbative QCD expansion. Our first observation is that in the APT analysis the three-loop contribution (of an order of α s 3 ) is as a rule numerically inessential. This raises hope for practical solving the well-known problem of asymptotic nature of common QFT perturbation series. The second conclusion is that a common perturbative analysis of time-like events with the big π 2 term in the π 2 coefficient is not adequate at s ≤ 2 GeV 2 . In particular, this relates to τ decay. Then, for the 'high' (f = 5) region it is shown that the common two-loop (NLO, NLLA) perturbation approximation widely used there (at 10 GeV ≤ √s ≤ 170 GeV) for analysis of shape/events data contains a systematic negative error of a 1 - 2 per cent level for the extracted α bar s (2) values. Our physical conclusion is that the α bar s (M Z 2 ) value averaged over the f = 5 data s (M Z 2 )> APT; f= 5 ≅ 0.124 appreciably differs from the currently accepted 'world average' (= 0.118)

2018 Canadian Cardiovascular Society/Canadian Association of Interventional Cardiology Focused Update of the Guidelines for the Use of Antiplatelet Therapy.

Science.gov (United States)

Mehta, Shamir R; Bainey, Kevin R; Cantor, Warren J; Lordkipanidzé, Marie; Marquis-Gravel, Guillaume; Robinson, Simon D; Sibbald, Matthew; So, Derek Y; Wong, Graham C; Abunassar, Joseph G; Ackman, Margaret L; Bell, Alan D; Cartier, Raymond; Douketis, James D; Lawler, Patrick R; McMurtry, Michael S; Udell, Jacob A; van Diepen, Sean; Verma, Subodh; Mancini, G B John; Cairns, John A; Tanguay, Jean-François

2018-03-01

Antiplatelet therapy (APT) has become an important tool in the treatment and prevention of atherosclerotic events, particularly those associated with coronary artery disease. A large evidence base has evolved regarding the relationship between APT prescription in various clinical contexts and risk/benefit relationships. The Guidelines Committee of the Canadian Cardiovascular Society and Canadian Association of Interventional Cardiology publishes regular updates of its recommendations, taking into consideration the most recent clinical evidence. The present update to the 2011 and 2013 Canadian Cardiovascular Society APT guidelines incorporates new evidence on how to optimize APT use, particularly in situations in which few to no data were previously available. The recommendations update focuses on the following primary topics: (1) the duration of dual APT (DAPT) in patients who undergo percutaneous coronary intervention (PCI) for acute coronary syndrome and non-acute coronary syndrome indications; (2) management of DAPT in patients who undergo noncardiac surgery; (3) management of DAPT in patients who undergo elective and semiurgent coronary artery bypass graft surgery; (4) when and how to switch between different oral antiplatelet therapies; and (5) management of antiplatelet and anticoagulant therapy in patients who undergo PCI. For PCI patients, we specifically analyze the particular considerations in patients with atrial fibrillation, mechanical or bioprosthetic valves (including transcatheter aortic valve replacement), venous thromboembolic disease, and established left ventricular thrombus or possible left ventricular thrombus with reduced ejection fraction after ST-segment elevation myocardial infarction. In addition to specific recommendations, we provide values and preferences and practical tips to aid the practicing clinician in the day to day use of these important agents. Copyright © 2018. Published by Elsevier Inc.

Systematic Review and Meta-Analysis: Is Pre-Injury Antiplatelet Therapy Associated with Traumatic Intracranial Hemorrhage?

Science.gov (United States)

van den Brand, Crispijn L; Tolido, Tanya; Rambach, Anna H; Hunink, Myriam G M; Patka, Peter; Jellema, Korné

2017-01-01

The objective of this systematic review and meta-analysis is to evaluate whether the pre-injury use of antiplatelet therapy (APT) is associated with increased risk of traumatic intracranial hemorrhage (tICH) on CT scan. PubMed, Medline, Embase, Cochrane Central, reference lists, and national guidelines on traumatic brain injury were used as data sources. Eligible studies were cohort studies and case-control studies that assessed the relationship between APT and tICH. Studies without control group were not included. The primary outcome of interest was tICH on CT. Two reviewers independently selected studies, assessed methodological quality, and extracted outcome data. This search resulted in 10 eligible studies with 20,247 patients with head injury that were included in the meta-analysis. The use of APT in patients with head injury was associated with significant increased risk of tICH compared with control (odds ratio [OR] 1.87, 95% confidence interval [CI]1.27-2.74). There was significant heterogeneity in the studies (I 2 84%), although almost all showed an association between APT use and tICH. This association could not be established for patients receiving aspirin monotherapy. When considering only patients with mild traumatic brain injury (mTBI), the OR is 2.72 (95% CI 1.92-3.85). The results were robust to sensitivity analysis on study quality. In summary, APT in patients with head injury is associated with increased risk of tICH; this association is most relevant in patients with mTBI. Whether this association is the result of a causal relationship and whether this relationship also exists for patients receiving aspirin monotherapy cannot be established with the current review and meta-analysis.

INITIAL VALIDATION OF THE ASSESSMENT OF PARENTING TOOL: A TASK- AND DOMAIN-LEVEL MEASURE OF PARENTING SELF-EFFICACY FOR PARENTS OF INFANTS FROM BIRTH TO 24 MONTHS OF AGE.

Science.gov (United States)

Moran, Tracy E; Polanin, Joshua R; Evenson, Amber L; Troutman, Beth R; Franklin, Christina L

2016-05-01

Parenting self-efficacy (PSE) includes parents' self-perceptions regarding their capabilities in performing the numerous and changing tasks associated with parenting a specific child (i.e., domain-specific PSE) as well as their self-perceptions in the parenting role overall (i.e., domain-general PSE). Prior literature has demonstrated PSE's relations with numerous constructs significant to mental health and the parent-infant relationship. Prior measures of PSE have been limited by focusing on only domain-specific or domain-general PSE, ignoring the importance of infant development to PSE, and other psychometric limitations. This article presents sound psychometric data for a new measure of PSE, the Assessment of Parenting Tool (APT). The APT includes task-level items on the Domain-Specific subscale (APT-DS) for each age-referenced version of the measure as well as a domain-general subscale that taps overall PSE within the first 24 months' postpartum. Initial construct validity of the measure is established, particularly for parents of infants aged 3 months and older. A stable, three-factor structure for the domain-general subscale includes "coping with being a parent," "attuned parenting," and "self-perceived model parenting." Future directions for the APT, including a revised checklist format for the domain-specific subscale, are included. © 2016 Michigan Association for Infant Mental Health.

Ordering and site occupancy of D03 ordered Fe3Al-5 at%Cr evaluated by means of atom probe tomography

International Nuclear Information System (INIS)

Rademacher, Thomas; Al-Kassab, Talaat; Deges, Johannes; Kirchheim, Reiner

2011-01-01

Addition of ternary elements to the D0 3 ordered Fe 3 Al intermetallic phase is a general approach to optimise its mechanical properties. To understand the physical influences of such additions the determination of the probability of site occupancies of these additions on the lattice site and ordering parameters is of high interest. Some common experimental techniques such as X-ray diffraction or Atom Location by Channelling Enhanced Microanalysis (ALCHEMI) are usually applied to explore this interplay. Unfortunately, certain published results are partly inconsistent, imprecise or even contradictory. In this study, these aspects are evaluated systematically by atom probe tomography (APT) and a special data analysis method. Additionally, to account for possible field evaporation effects that can falsify the estimation of site occupancy and induce misinterpretations, APT evaporation sequences were also simulated. As a result, chromium occupies most frequently the next nearest neighbour sites of Al atoms and local ordering parameters could be achieved. -- Research highlights: → APT measurements of Fe 3 Al-Cr are systematically analysed to study ordering. → APT measurements are simulated using EAM to calculate binding energies. → Cr occupies next nearest neighbour sites of aluminium with at least 83% ordering. → Aluminium ordering is at least 92%

The Unpredictable Effect of Changing Cardiac Output on Hypoxemia after Acute Pulmonary Thromboembolism

Directory of Open Access Journals (Sweden)

John Y. C. Tsang

2008-01-01

Full Text Available Previous studies reported that the degree of hypoxemia following acute pulmonary thromboembolism (APTE was highly variable and that its mechanism was mainly due to the creation of many high and low ventilation/perfusion (V/Q units, as a result of the heterogeneous regional blood flow (Q caused by embolic obstruction. We studied the effect of changing cardiac output (Q t on gas exchange after APTE in 5 embolized piglets (23 ± 3 Kg, using Dobutamine intermittently at approximately 20 μg/kg/min for 120 minutes. The distribution of ventilation (V and perfusion (Q at various times was mapped using fluorescent microspheres in 941 ± 60 lung regions. After APTE, increase in Q t by Dobutamine improved venous oxygen tension (PvO 2 but arterial PaO 2 did not change consistently. On the other hand, cluster analysis showed that the V/Q ratio of most lung regions was lowered due to increases in Q at the same time. We concluded that the effect of changing cardiac output on gas exchange following APTE was affected by the simultaneous and varying balance between the changing V/Q mismatch and the concomitantly changing PvO 2 , which might explain the unpredictability of PaO 2 in the clinical setting.

Three-dimensional atomic mapping of hydrogenated polymorphous silicon solar cells

Energy Technology Data Exchange (ETDEWEB)

Chen, Wanghua, E-mail: wanghua.chen@polytechnique.edu; Roca i Cabarrocas, Pere [LPICM, CNRS, Ecole Polytechnique, Université Paris-Saclay, 91128 Palaiseau (France); Pareige, Philippe [GPM, CNRS, Université et INSA de Rouen, Normandie Université, 76801 Saint Etienne du Rouvray (France)

2016-06-20

Hydrogenated polymorphous silicon (pm-Si:H) is a nanostructured material consisting of silicon nanocrystals embedded in an amorphous silicon matrix. Its use as the intrinsic layer in thin film p-i-n solar cells has led to good cell properties in terms of stability and efficiency. Here, we have been able to assess directly the concentration and distribution of nanocrystals and impurities (dopants) in p-i-n solar cells, by using femtosecond laser-assisted atom probe tomography (APT). An effective sample preparation method for APT characterization is developed. Based on the difference in atomic density between hydrogenated amorphous and crystalline silicon, we are able to distinguish the nanocrystals from the amorphous matrix by using APT. Moreover, thanks to the three-dimensional reconstruction, we demonstrate that Si nanocrystals are homogeneously distributed in the entire intrinsic layer of the solar cell. The influence of the process pressure on the incorporation of nanocrystals and their distribution is also investigated. Thanks to APT we could determine crystalline fractions as low as 4.2% in the pm-Si:H films, which is very difficult to determine by standard techniques, such as X-ray diffraction, Raman spectroscopy, and spectroscopic ellipsometry. Moreover, we also demonstrate a sharp p/i interface in our solar cells.

PENERAPAN MODEL ARBITRAGE PRICING THEORY DENGAN PENDEKATAN VECTOR AUTOREGRESSION DALAM MENGESTIMASI EXPECTED RETURN SAHAM (Studi Kasus: Saham-Saham Kompas100 Periode 2010-2013

Directory of Open Access Journals (Sweden)

VIAN RISKA AYUNING TYAS

2014-01-01

Full Text Available The Arbitrage Pricing Theory (APT is an alternative model to estimate the price of securities based of arbitrage concept. In APT, the returns of securities are affected by several factors. This research is aimed to estimate the expected returns of securities using APT model and Vector Autoregressive model. There are ten stocks incorporated in Kompas100 index and four macroeconomic variables, these are inflation, exchange rates, the amountof circulate money (JUB, and theinterest rateof Bank Indonesia(SBI are applied in this research. The first step in using VAR is to test the stationary of the data using colerogram and the results indicate that all data are stationary. The second step is to select the optimal lag based on the smallest value of AIC. The Granger causality test shows that the LPKR stock is affected by the inflation and the exchange rate while the nine other stocks do not show the existence of the expected causality. The results of causality test are then estimated by the VAR models in order to obtain expected returnof macroeconomic factors. The expected return of macroeconomic factors obtained is used in the APT model, then the expected return stock LPKR is calculated. It shows that the expected return of LPKR is 3,340%

PENERAPAN MODEL ARBITRAGE PRICING THEORY DENGAN PENDEKATAN VECTOR AUTOREGRESSION DALAM MENGESTIMASI EXPECTED RETURN SAHAM (Studi Kasus: Saham-Saham Kompas100 Periode 2010-2013

Directory of Open Access Journals (Sweden)

VIAN RISKA AYUNING TYAS

2014-08-01

Full Text Available The Arbitrage Pricing Theory (APT is an alternative model to estimate the price of securities based of arbitrage concept. In APT, the returns of securities are affected by several factors. This research is aimed to estimate the expected returns of securities using APT model and Vector Autoregressive model. There are ten stocks incorporated in Kompas100 index and four macroeconomic variables, these are inflation, exchange rates, the amountof circulate money (JUB, and theinterest rateof Bank Indonesia(SBI are applied in this research. The first step in using VAR is to test the stationary of the data using colerogram and the results indicate that all data are stationary. The second step is to select the optimal lag based on the smallest value of AIC. The Granger causality test shows that the LPKR stock is affected by the inflation and the exchange rate while the nine other stocks do not show the existence of the expected causality. The results of causality test are then estimated by the VAR models in order to obtain expected returnof macroeconomic factors. The expected return of macroeconomic factors obtained is used in the APT model, then the expected return stock LPKR is calculated. It shows that the expected return of LPKR is 3,340%

Elimination of reactive blue 4 from aqueous solutions using 3-aminopropyl triethoxysilane modified chitosan beads.

Science.gov (United States)

Vakili, Mohammadtaghi; Rafatullah, Mohd; Salamatinia, Babak; Ibrahim, Mahamad Hakimi; Abdullah, Ahmad Zuhairi

2015-11-05

The adsorption behavior of chitosan (CS) beads modified with 3-aminopropyl triethoxysilane (APTES) for the removal of reactive blue 4 (RB4) in batch studies has been investigated. The effects of modification conditions, such as the APTES concentration, temperature and reaction time on RB4 removal, were studied. The adsorbent prepared at a concentration of 2 wt% APTES for 8h at 50 °C was the most effective one for RB4 adsorption. The adsorption capacity of modified CS beads (433.77 mg/g) was 1.37 times higher than that of unmodified CS beads (317.23 mg/g). The isotherm data are adequately described by a Freundlich model, and the kinetic study revealed that the pseudo-second-order rate model was in better agreement with the experimental data. The negative values of the thermodynamic parameters, including ΔG° (-2.28 and -4.70 kJ/mol at 30 ± 2 °C), ΔH° (-172.18 and -43.82 kJ/mol) and ΔS° (-560.71 and -129.08 J/mol K) for CS beads and APTES modified beads, respectively, suggest that RB4 adsorption is a spontaneous and exothermic process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ultra-sensitive detection of ibuprofen (IBP) by electrochemical aptasensor using the dendrimer-quantum dot (Den-QD) bioconjugate as an immobilization platform with special features

Energy Technology Data Exchange (ETDEWEB)

Roushani, Mahmoud, E-mail: m.roushani@ilam.ac.ir; Shahdost-fard, Faezeh

2017-06-01

This study describes a high-performance electrochemical aptasensor which is employed to detect Ibuprofen (IBP) as a painkiller drug by using a novel platform as an integrated sensing interface. In order to make the aptasensor, the Den-QD bioconjugate was immobilized on the surface of a GC electrode and followed the Apt was incubated on this surface. The incubation of the IBP on the aptasensor surface and the formation of the Apt/IBP complex, led to a hindered electron transfer reaction on the sensing surface, which decreased the peak current of the redox probe. Under the optimum condition, the assay had two dynamic ranges with a detection limit down to 333 fM. The developed aptasensor reliably detects IBP in a real sample. Our results demonstrated that the proposed strategy has many advantages and the Den-QD bioconjugate may become a promising nanocomposite for the electrochemical sensing applications. - Highlights: • Fabrication of an ultrasensitive electrochemical nanotool based on target-including conformational switching of an Apt. • The covalent attachment of a 5'-NH2-3'-AgNPs terminated Apt on the surface of a GCE electrode with CdTe QDs. • The use of CdTe QDs as a platform and the elimination of antibodies or enzymes are the advantages of this aptasensor.

A Promising Combo Gene Delivery System Developed from (3-Aminopropyl)triethoxysilane-Modified Iron Oxide Nanoparticles and Cationic Polymers

Science.gov (United States)

Zhang, Zubin; Song, Lina; Dong, Jinlai; Guo, Dawei; Du, Xiaolin; Cao, Biyin; Zhang, Yu; Gu, Ning; Mao, Xinliang

2013-05-01

(3-Aminopropyl)triethoxysilane-modified iron oxide nanoparticles (APTES-IONPs) have been evaluated for various biomedical applications, including medical imaging and drug delivery. Cationic polymers (CPs) such as Lipofectamine and TurboFect are widely used for research in gene delivery, but their toxicity and low in vivo efficiency limited their further application. In the present study, we synthesized water-soluble APTES-IONPs and developed a combo gene delivery system based on APTES-IONPs and CPs. This system significantly increased gene-binding capacity, protected genes from degradation, and improved gene transfection efficiency for DNA and siRNA in both adherent and suspension cells. Because of its great biocompatibility, high gene-carrying ability, and very low cytotoxicity, this combo gene delivery system will be expected for a wide application, and it might provide a new method for gene therapy.

A Promising Combo Gene Delivery System Developed from (3-Aminopropyl)triethoxysilane-Modified Iron Oxide Nanoparticles and Cationic Polymers

International Nuclear Information System (INIS)

Zhang Zubin; Song Lina; Dong Jinlai; Guo Dawei; Du Xiaolin; Cao Biyin; Zhang Yu; Gu Ning; Mao Xinliang

2013-01-01

(3-Aminopropyl)triethoxysilane-modified iron oxide nanoparticles (APTES-IONPs) have been evaluated for various biomedical applications, including medical imaging and drug delivery. Cationic polymers (CPs) such as Lipofectamine and TurboFect are widely used for research in gene delivery, but their toxicity and low in vivo efficiency limited their further application. In the present study, we synthesized water-soluble APTES-IONPs and developed a combo gene delivery system based on APTES-IONPs and CPs. This system significantly increased gene-binding capacity, protected genes from degradation, and improved gene transfection efficiency for DNA and siRNA in both adherent and suspension cells. Because of its great biocompatibility, high gene-carrying ability, and very low cytotoxicity, this combo gene delivery system will be expected for a wide application, and it might provide a new method for gene therapy.

Synthetic Analysis about Single-Criterion and Multi-Criterion Financial Assets Portfolio

Directory of Open Access Journals (Sweden)

Leonardo Badea

2006-06-01

Full Text Available This paper as a synthetic analyzis based on the Markowitz and Sharpe models deals with the problem of portfolio trying to determine both the optimum proportion of titles and the influence of a considered macroeconomic factor over their level of efficiency and risk. The improvement of these models was made through the introduction of a new model, the APT model (Arbitrage Price Theory, as a development of the uni-factorial CAPM model, in other words, the above-mentioned model only constitutes a particular form of the APT model trying to establish a relationship between the individual efficiency of a title from the portfolio and several macroeconomic factors. Also, this model involves the identification of macroeconomic factors influencing the profitability of the titles and the determination of the influence of these factors individually, through the application of the APT model.

Synthetic Analysis about Single-Criterion and Multi-Criterion Financial Assets Portfolio

Directory of Open Access Journals (Sweden)

Leonardo Badea

2006-08-01

Full Text Available This paper as a synthetic analyzis based on the Markowitz and Sharpe models deals with the problem of portfolio trying to determine both the optimum proportion of titles and the influence of a considered macroeconomic factor over their level of efficiency and risk. The improvement of these models was made through the introduction of a new model, the APT model (Arbitrage Price Theory, as a development of the uni-factorial CAPM model, in other words, the above-mentioned model only constitutes a particular form of the APT model trying to establish a relationship between the individual efficiency of a title from the portfolio and several macroeconomic factors. Also, this model involves the identification of macroeconomic factors influencing the profitability of the titles and the determination of the influence of these factors individually, through the application of the APT model.

Automatic Photoelectric Telescope Service

International Nuclear Information System (INIS)

Genet, R.M.; Boyd, L.J.; Kissell, K.E.; Crawford, D.L.; Hall, D.S.; BDM Corp., McLean, VA; Kitt Peak National Observatory, Tucson, AZ; Dyer Observatory, Nashville, TN)

1987-01-01

Automatic observatories have the potential of gathering sizable amounts of high-quality astronomical data at low cost. The Automatic Photoelectric Telescope Service (APT Service) has realized this potential and is routinely making photometric observations of a large number of variable stars. However, without observers to provide on-site monitoring, it was necessary to incorporate special quality checks into the operation of the APT Service at its multiple automatic telescope installation on Mount Hopkins. 18 references

STRUCTURAL DESIGN CRITERIA FOR TARGET/BLANKET SYSTEM COMPONENT MATERIALS FOR THE ACCELERATOR PRODUCTION OF TRITIUM PROJECT

Energy Technology Data Exchange (ETDEWEB)

W. JOHNSON; R. RYDER; P. RITTENHOUSE

2001-01-01

The design of target/blanket system components for the Accelerator Production of Tritium (APT) plant is dependent on the development of materials properties data specified by the designer. These data are needed to verify that component designs are adequate. The adequacy of the data will be related to safety, performance, and economic considerations, and to other requirements that may be deemed necessary by customers and regulatory bodies. The data required may already be in existence, as in the open technical literature, or may need to be generated, as is often the case for the design of new systems operating under relatively unique conditions. The designers' starting point for design data needs is generally some form of design criteria used in conjunction with a specified set of loading conditions and associated performance requirements. Most criteria are aimed at verifying the structural adequacy of the component, and often take the form of national or international standards such as the ASME Boiler and Pressure Vessel Code (ASME B and PV Code) or the French Nuclear Structural Requirements (RCC-MR). Whether or not there are specific design data needs associated with the use of these design criteria will largely depend on the uniqueness of the conditions of operation of the component. A component designed in accordance with the ASME B and PV Code, where no unusual environmental conditions exist, will utilize well-documented, statistically-evaluated developed in conjunction with the Code, and will not be likely to have any design data needs. On the other hand, a component to be designed to operate under unique APT conditions, is likely to have significant design data needs. Such a component is also likely to require special design criteria for verification of its structural adequacy, specifically accounting for changes in materials properties which may occur during exposure in the service environment. In such a situation it is common for the design criteria

Preparation of crosslinked polysiloxane/SiO2 nanocomposite via in-situ condensation and its surface modification on cotton fabrics

Science.gov (United States)

Hao, Lifen; Gao, Tingting; Xu, Wei; Wang, Xuechuan; Yang, Shuqin; Liu, Xiangguo

2016-05-01

Novel crosslinked polysiloxane/SiO2 nanocomposite (CLPS-SiO2) was successfully prepared via the in-situ condensation reaction of silica sols and crosslinked polysiloxane with end-capped triethoxysilane in solvent, which was firstly fabricated through the modification of our previously developed crosslinked polysiloxane with end-capped epoxy groups using aminopropyltriethoxysilane (APTES) and noted as APTES-CLPS. Chemical structures and thermal properties of the as-prepared resultants were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectra (1H/13C NMR) and thermogravimetric analysis (TGA). CLPS-SiO2 was applied as surface modification agent to treat cotton fabrics. Film morphologies and surface properties were examined with scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), contact angle measurements, and other instruments. FTIR and NMR confirmed structure of the products. CLPS-SiO2 showed better thermal stability than APTES-CLPS due to anchor of the nanosilica. APTES-CLPS could deposit a smooth film on cotton fiber surface. Besides, CLPS-SiO2 also coated the fibers with many nano-scaled tubercles beneath this smooth film by SEM. However, the APTES-CLPS film and the CLPS-SiO2 film on silicon-wafer were never homogeneous and had a few low or high peaks. The root mean square roughness (Rq) of APTES-CLPS film reached to 0.441 nm in 2 × 2 μm2 scanning field and at 5 nm data scale. Owing to the incorporation of nanosilica, that of CLPS-SiO2 film continuously increased and could attain 4.528 nm in 2 × 2 μm2 scanning field and at 20 nm data scale. XPS analysis further demonstrates that there was a CLPS-SiO2 film covered on the cotton surface and the silyl groups had the tendency to enrich at the film-air interface. In addition, hydrophobicity of the CLPS-SiO2 treated fabric would be enhanced with augment of the amount of nanocomposite. Water contact angle of this

The Effect of Improved Crosslink Density on the Properties of Waterborne Polyurethanes Using Sol-Gel Process

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Ryul; Park, Jin Hwan [Pukyong National University, Busan (Korea, Republic of)

2016-12-15

Water-based systems are dominating the coating market because of worldwide VOCs regulations. Research is focusing especially on waterborne polyurethane (WPU) because of its unique mechanical and chemical properties. However, commercial WPU consists of linear thermoplastic polymers with polar groups on the main chain, which do not perform as well as solvent-borne PU in a two-pack system. In this study, APTES were used as a chain crosslink agent to overcome commercial WPU's limited performance. WPUs synthesized by using a sol-gel process were evaluated with FT-IR, particle analysis, TGA, tensile tests, pull-off tests, SEM, and EIS. The results showed that WPUs with added APTES had better thermal stability, mechanical properties, and water resistance than did WPUs without added APTES. Consequently, the sol-gel process increased the crosslink density of WPUs and modified the WPU's own properties.

Three dimensional atom probe study of Ni-base alloy/low alloy steel dissimilar metal weld interfaces

International Nuclear Information System (INIS)

Choi, Kyoung Joon; Shin, Sang Hun; Kim, Jong Jin; Jung, Ju Ang; Kim, Ji Hyun

2012-01-01

Three dimensional atom probe tomography (3D APT) is applied to characterize the dissimilar metal joint which was welded between the Ni-based alloy, Alloy 690 and the low alloy steel, A533 Gr. B, with Alloy 152 filler metal. While there is some difficulty in preparing the specimen for the analysis, the 3D APT has a truly quantitative analytical capability to characterize nanometer scale particles in metallic materials, thus its application to the microstructural analysis in multicomponent metallic materials provides critical information on the mechanism of nanoscale microstructural evolution. In this study, the procedure for 3D APT specimen preparation was established, and those for dissimilar metal weld interface were prepared near the fusion boundary by a focused ion beam. The result of the analysis in this study showed the precipitation of chromium carbides near the fusion boundary between A533 Gr. B and Alloy 152.

Three dimensional atom probe study of Ni-base alloy/low alloy steel dissimilar metal weld interfaces

Energy Technology Data Exchange (ETDEWEB)

Choi, Kyoung Joon; Shin, Sang Hun; Kim, Jong Jin; Jung, Ju Ang; Kim, Ji Hyun [Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

2012-08-15

Three dimensional atom probe tomography (3D APT) is applied to characterize the dissimilar metal joint which was welded between the Ni-based alloy, Alloy 690 and the low alloy steel, A533 Gr. B, with Alloy 152 filler metal. While there is some difficulty in preparing the specimen for the analysis, the 3D APT has a truly quantitative analytical capability to characterize nanometer scale particles in metallic materials, thus its application to the microstructural analysis in multicomponent metallic materials provides critical information on the mechanism of nanoscale microstructural evolution. In this study, the procedure for 3D APT specimen preparation was established, and those for dissimilar metal weld interface were prepared near the fusion boundary by a focused ion beam. The result of the analysis in this study showed the precipitation of chromium carbides near the fusion boundary between A533 Gr. B and Alloy 152.

The Prediction Performance of Asset Pricing Models and Their Capability of Capturing the Effects of Economic Crises: The Case of Istanbul Stock Exchange

Directory of Open Access Journals (Sweden)

Erol Muzır

2010-09-01

Full Text Available This paper is prepared to test the common opinion that the multifactor asset pricing models produce superior predictions as compared to the single factor models and to evaluate the performance of Arbitrage Pricing Theory (APT and Capital Asset Pricing Model (CAPM. For this purpose, the monthly return data from January 1996 and December 2004 of the stocks of 45 firms listed at Istanbul Stock Exchange were used. Our factor analysis results show that 68,3 % of the return variation can be explained by five factors. Although the APT model has generated a low coefficient of determination, 28,3 %, it proves to be more competent in explaining stock return changes when compared to CAPM which has an inferior explanation power, 5,4 %. Furthermore, we have observed that APT is more robust also in capturing the effects of any economic crisis on return variations.

Effect of gas temperature on flow rate characteristics of an averaging pitot tube type flow meter

Energy Technology Data Exchange (ETDEWEB)

Yeo, Seung Hwa; Lee, Su Ryong; Lee, Choong Hoon [Seoul National University of Science and Technology, Seoul (Korea, Republic of)

2015-01-15

The flow rate characteristics passing through an averaging Pitot tube (APT) while constantly controlling the flow temperature were studied through experiments and CFD simulations. At controlled temperatures of 25, 50, 75, and 100 .deg .C, the flow characteristics, in this case the upstream, downstream and static pressure at the APT flow meter probe, were measured as the flow rate was increased. The flow rate through the APT flow meter was represented using the H-parameter (hydraulic height) obtained by a combination of the differential pressure and the air density measured at the APT flow meter probe. Four types of H-parameters were defined depending on the specific combination. The flow rate and the upstream, downstream and static pressures measured at the APT flow meter while changing the H-parameters were simulated by means of CFD. The flow rate curves showed different features depending on which type of H-parameter was used. When using the constant air density value in a standard state to calculate the H-parameters, the flow rate increased linearly with the H-parameter and the slope of the flow rate curve according to the H-parameter increased as the controlled target air temperature was increased. When using different air density levels corresponding to each target air temperature to calculate the H-parameter, the slope of the flow rate curve according to the H-parameter was constant and the flow rate curve could be represented by a single line. The CFD simulation results were in good agreement with the experimental results. The CFD simulations were performed while increasing the air temperature to 1200 K. The CFD simulation results for high air temperatures were similar to those at the low temperature ranging from 25 to 100 .deg. C.

Effect of gas temperature on flow rate characteristics of an averaging pitot tube type flow meter

International Nuclear Information System (INIS)

Yeo, Seung Hwa; Lee, Su Ryong; Lee, Choong Hoon

2015-01-01

The flow rate characteristics passing through an averaging Pitot tube (APT) while constantly controlling the flow temperature were studied through experiments and CFD simulations. At controlled temperatures of 25, 50, 75, and 100 .deg .C, the flow characteristics, in this case the upstream, downstream and static pressure at the APT flow meter probe, were measured as the flow rate was increased. The flow rate through the APT flow meter was represented using the H-parameter (hydraulic height) obtained by a combination of the differential pressure and the air density measured at the APT flow meter probe. Four types of H-parameters were defined depending on the specific combination. The flow rate and the upstream, downstream and static pressures measured at the APT flow meter while changing the H-parameters were simulated by means of CFD. The flow rate curves showed different features depending on which type of H-parameter was used. When using the constant air density value in a standard state to calculate the H-parameters, the flow rate increased linearly with the H-parameter and the slope of the flow rate curve according to the H-parameter increased as the controlled target air temperature was increased. When using different air density levels corresponding to each target air temperature to calculate the H-parameter, the slope of the flow rate curve according to the H-parameter was constant and the flow rate curve could be represented by a single line. The CFD simulation results were in good agreement with the experimental results. The CFD simulations were performed while increasing the air temperature to 1200 K. The CFD simulation results for high air temperatures were similar to those at the low temperature ranging from 25 to 100 .deg. C.

Adding silver and copper to hydrogen peroxide and peracetic acid in the disinfection of an advanced primary treatment effluent.

Science.gov (United States)

Orta De Velásquez, M T; Yáñez-Noguez, I; Jiménez-Cisneros, B; Luna Pabello, V M

2008-11-01

This paper evaluates the efficacy of hydrogen peroxide (HP) and peracetic acid (PAA) in the disinfection of an Advanced Primary Treatment (APT) effluent, and how said disinfection capacities can be enhanced by combining the oxidants with copper (Cu2+) and silver (Ag). The treatment sequence consisted of APT (adding chemicals to water to remove suspended solids by coagulation and flocculation), followed by disinfection with various doses of HP, HP+Cu2+, HP+Ag, PAA and PAA+Ag. Microbiological quality was determined by monitoring concentrations of fecal coliforms (FC), pathogenic bacteria (PB) and helminth eggs (HE) throughout the sequence. The results revealed that APT effluent still contains very high levels of bacteria as the treatment only removes 1-2 log of FC and PB, but the reduction in the number of viable helminth eggs was 83%. Subsequent disinfection stages demonstrated that both HP+Cu2+ and HP+Ag have a marked disinfection capacity for bacteria (3.9 and 3.4 log-inactivation, respectively). Peracetic acid on its own was already extremely efficient at disinfecting for bacteria, and the effect was enhanced when combining PAA with silver (PAA+Ag). The best result for HE removal was achieved by combining PAA with silver (PAA+Ag) at doses of 20 + 2.0 mg l(-1), respectively. The study concluded that the PAA+Ag and HP+Ag combinations were good alternatives for APT effluent disinfection, because the disinfected effluents met the standards in NOM-001-SEMARNAT-1996, Mexico's regulation governing the microbiological quality required in treated wastewater destined for unrestricted reuse in agricultural irrigation (disinfection treatments with a primary method such as APT, therefore, offers an effective and practical way of reducing the health risks normally associated with the reuse of wastewaters.

Amide Proton Transfer Magnetic Resonance Imaging of Alzheimer′s Disease at 3.0 Tesla: A Preliminary Study

Directory of Open Access Journals (Sweden)

Rui Wang

2015-01-01

Full Text Available Background: Amide proton transfer (APT imaging has recently emerged as an important contrast mechanism for magnetic resonance imaging (MRI in the field of molecular and cellular imaging. The aim of this study was to evaluate the feasibility of APT imaging to detect cerebral abnormality in patients with Alzheimer′s disease (AD at 3.0 Tesla. Methods: Twenty AD patients (9 men and 11 women; age range, 67-83 years and 20 age-matched normal controls (11 men and 9 women; age range, 63-82 years underwent APT and traditional MRI examination on a 3.0 Tesla MRI system. The magnetic resonance ratio asymmetry (MTR asym values at 3.5 ppm of bilateral hippocampi (Hc, temporal white matter regions, occipital white matter regions, and cerebral peduncles were measured on oblique axial APT images. MTR asym (3.5 ppm values of the cerebral structures between AD patients and control subjects were compared with independent samples t-test. Controlling for age, partial correlation analysis was used to investigate the associations between mini-mental state examination (MMSE and the various MRI measures among AD patients. Results: Compared with normal controls, MTR asym (3.5 ppm values of bilateral Hc were significantly increased in AD patients (right 1.24% ± 0.21% vs. 0.83% ± 0.19%, left 1.18% ± 0.18% vs. 0.80%± 0.17%, t = 3.039, 3.328, P = 0.004, 0.002, respectively. MTR asym (3.5 ppm values of bilateral Hc were significantly negatively correlated with MMSE (right r = −0.559, P = 0.013; left r = −0.461, P = 0.047. Conclusions: Increased MTR asym (3.5 ppm values of bilateral Hc in AD patients and its strong correlations with MMSE suggest that APT imaging could potentially provide imaging biomarkers for the noninvasive molecular diagnosis of AD.

Quantitative atom probe analysis of nanostructure containing clusters and precipitates with multiple length scales

International Nuclear Information System (INIS)

Marceau, R.K.W.; Stephenson, L.T.; Hutchinson, C.R.; Ringer, S.P.

2011-01-01

A model Al-3Cu-(0.05 Sn) (wt%) alloy containing a bimodal distribution of relatively shear-resistant θ' precipitates and shearable GP zones is considered in this study. It has recently been shown that the addition of the GP zones to such microstructures can lead to significant increases in strength without a decrease in the uniform elongation. In this study, atom probe tomography (APT) has been used to quantitatively characterise the evolution of the GP zones and the solute distribution in the bimodal microstructure as a function of applied plastic strain. Recent nuclear magnetic resonance (NMR) analysis has clearly shown strain-induced dissolution of the GP zones, which is supported by the current APT data with additional spatial information. There is significant repartitioning of Cu from the GP zones into the solid solution during deformation. A new approach for cluster finding in APT data has been used to quantitatively characterise the evolution of the sizes and shapes of the Cu containing features in the solid solution solute as a function of applied strain. -- Research highlights: → A new approach for cluster finding in atom probe tomography (APT) data has been used to quantitatively characterise the evolution of the sizes and shapes of the Cu containing features with multiple length scales. → In this study, a model Al-3Cu-(0.05 Sn) (wt%) alloy containing a bimodal distribution of relatively shear-resistant θ' precipitates and shearable GP zones is considered. → APT has been used to quantitatively characterise the evolution of the GP zones and the solute distribution in the bimodal microstructure as a function of applied plastic strain. → It is clearly shown that there is strain-induced dissolution of the GP zones with significant repartitioning of Cu from the GP zones into the solid solution during deformation.

Amino-functionalized surface modification of polyacrylonitrile hollow fiber-supported polydimethylsiloxane membranes

Energy Technology Data Exchange (ETDEWEB)

Hu, Leiqing; Cheng, Jun, E-mail: juncheng@zju.edu.cn; Li, Yannan; Liu, Jianzhong; Zhou, Junhu; Cen, Kefa

2017-08-15

Highlights: • Amino group was introduced to improve surface polarity of PDMS membrane. • The water contact angle of PDMS membrane decreased after the modification. • The concentration of N atom on surface of PDMS membrane reached up to ∼6%. • The density of PDMS membrane decreased while the swelling degree increased. • CO{sub 2} permeability increased while selectivity decreased after the modification. - Abstract: This study aimed to improve surface polarity of polydimethylsiloxane (PDMS) membranes and provide surface active sites which were easy to react with other chemicals. 3-Aminopropyltriethoxysilane (APTES) containing an amino group was introduced into a PDMS membrane by crosslinking to prepare polyacrylonitrile hollow fiber-supported PDMS membranes with an amino-functionalized surface. Fourier transform infrared and X-ray photoelectron spectroscopic analyses proved the existence of APTES and its amino group in the PDMS membrane. The concentration of N atoms on the PDMS membrane surface reached ∼6% when the mass ratio of APTES/PDMS oligomer in the PDMS coating solution was increased to 4/3. The water contact angle decreased from ∼114° to ∼87.5°, indicating the improved surface polarization of the PDMS membrane. The density and swelling degree of the PDMS membrane decreased and increased, respectively, with increasing APTES content in PDMS. This phenomenon increased CO{sub 2} permeability and decreased CO{sub 2}/H{sub 2} selectivity, CO{sub 2}/CH{sub 4} selectivity, and CO{sub 2}/N{sub 2} selectivity. When the mass ratio of APTES/PDMS oligomer was increased from 0 to 4/3, the CO{sub 2} permeation rate of the hollow fiber-supported PDMS membranes initially decreased from ∼2370 GPU to ∼860 GPU and then increased to ∼2000 GPU due to the change in coating solution viscosity.

Interactive visualization of APT data at full fidelity

International Nuclear Information System (INIS)

Bryden, Aaron; Broderick, Scott; Suram, Santosh K.; Kaluskar, Kaustubh; LeSar, Richard; Rajan, Krishna

2013-01-01

Understanding the impact of noise and incomplete data is a critical need for using atom probe tomography effectively. Although many tools and techniques have been developed to address this problem, visualization of the raw data remains an important part of this process. In this paper, we present two contributions to the visualization of data acquired through atom probe tomography. First, we describe the application of a rendering technique, ray-cast spherical impostors, that enables the interactive rendering of large numbers (as large as 10 million plus) of pixel perfect, lit spheres representing individual atoms. This technique is made possible by the use of a consumer-level graphics processing unit (GPU), and it yields an order of magnitude improvement both in render quality and speed over techniques previously used to render spherical glyphs in this domain. Second, we present an interactive tool that allows the user to mask, filter, and colorize the data in real time to help them understand and visualize a precise subset and properties of the raw data. We demonstrate the effectiveness of our tool through benchmarks and an example that shows how the ability to interactively render large numbers of spheres, combined with the use of filters and masks, leads to improved understanding of the three-dimensional (3D) and incomplete nature of atom probe data. This improvement arises from the ability of lit spheres to more effectively show the 3D position and the local spatial distribution of individual atoms than what is possible with point or isosurface renderings. The techniques described in this paper serve to introduce new rendering and interaction techniques that have only recently become practical as well as new ways of interactively exploring the raw data. - Highlights: ► Application of spherical impostor rendering to atom probe data visualization. ► Presented an interactive tool for visualizing atom probe tomography data. ► Presented a comparison of rendering performance of our tool with commercial tools. ► An example of how our tool can be used to understand atom probe tomography data

Apt strain measurement technique for impulsive loading applications

International Nuclear Information System (INIS)

Nanda, Soumya Ranjan; Kulkarni, Vinayak; Sahoo, Niranjan

2017-01-01

The necessity of precise measurement of strain time history for impulsive loading applications has been addressed in the present investigation. Finite element modeling is initially carried out for a hemispherical test model and stress bar assembly to arrive at an appropriate location for strain measurement. In dynamic calibration experiments, strain measurements are performed using two wire and three wire quarter bride arrangements along with half bridge circuit. Usefulness of these arrangements has been verified by analyzing strain signals in time and frequency domains. Comparison of recovered force time histories proved that the half bridge circuit is the most suitable for such applications. Actual shock tube testing of the instrumented hemispherical test model confirmed the applicability of half bridge circuit for short duration strain measurements. (technical note)

Science opportunities at high power accelerators like APT

International Nuclear Information System (INIS)

Browne, J.C.

1996-01-01

This paper presents applications of high power RF proton linear accelerators to several fields. Radioisotope production is an area in which linacs have already provided new isotopes for use in medical and industrial applications. A new type of spallation neutron source, called a long-pulse spallation source (LPSS), is discussed for application to neutron scattering and to the production and use of ultra-cold neutrons (UCN). The concept of an accelerator-driven, transmutation of nuclear waste system, based on high power RF linac technology, is presented along with its impact on spent nuclear fuels

Bridging the gap between APT results and practices

CSIR Research Space (South Africa)

Kleyn, EG

1999-04-01

Full Text Available This paper describes the managerial approach and the process developed by the CSIR and the road authorities in managing the HVS projects and implementing the findings.The paper concludes with diagrammatic representation of the interactive process...

APT {sup 3}He target/blanket. Topical report

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-03-01

The {sup 3}He target/blanket (T/B) preconceptual design for the 3/8-Goal facility is based on a 1000-MeV, 200-mA accelerator to produce a high-intensity proton beam that is expanded and then strikes one of two T/B modules. Each module consists of a centralized neutron source made of tungsten and lead, a proton beam backstop region made of zirconium and lead, and a moderator made of D{sub 2}O. Helium-3 gas is circulated through the neutron source region and the blanket to create tritium through neutron capture. The gas is continually processed to extract the tritium with an online separation process.

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

Comparative Study of Electroless Copper Film on Different Self-Assembled Monolayers Modified ABS Substrate

Directory of Open Access Journals (Sweden)

Jiushuai Xu

2014-04-01

Full Text Available Copper films were grown on (3-Mercaptopropyltrimethoxysilane (MPTMS, (3-Aminopropyltriethoxysilane (APTES and 6-(3-(triethoxysilylpropylamino-1,3,5- triazine-2,4-dithiol monosodium (TES self-assembled monolayers (SAMs modified acrylonitrile-butadiene-styrene (ABS substrate via electroless copper plating. The copper films were examined using scanning electron microscopy (SEM and X-ray diffraction (XRD. Their individual deposition rate and contact angle were also investigated to compare the properties of SAMs and electroless copper films. The results indicated that the formation of copper nuclei on the TES-SAMs modified ABS substrate was faster than those on the MPTMS-SAMs and APTES-SAMs modified ABS substrate. SEM images revealed that the copper film on TES-SAM modified ABS substrate was smooth and uniform, and the density of copper nuclei was much higher. Compared with that of TES-SAMs modified resin, the coverage of copper nuclei on MPTMS and APTES modified ABS substrate was very limited and the copper particle size was too big. The adhesion property test demonstrated that all the SAMs enhanced the interfacial interaction between copper plating and ABS substrate. XRD analysis showed that the copper film deposited on SAM-modified ABS substrate had a structure with Cu(111 preferred orientation, and the copper film deposited on TES-SAMs modified ABS substrate is better than that deposited on MPTMS-SAMs or APTES-SAMs modified ABS resins in electromigrtion resistance.

An overview of tritium production

International Nuclear Information System (INIS)

He Kaihui; Huang Jinghua; Feng Kaiming

2002-01-01

The characteristics of three types of proposed tritium production facilities, fissile type, accelerator production tritium (APT), and fusion type, are presented. The fissile reactors, especially commercial light water reactor, use comparatively mature technology and are designed to meet current safety and environmental guidelines. Conversely, APT shows many advantages except its rather high cost, while fusion reactors appear to offer improved safety and environmental impact, in particular, tritium production based on the fusion-based neutron source. However, its cost keeps unknown

Tankering Fuel: A Cost Saving Initiative

Science.gov (United States)

2011-05-01

2.41075 RIO DE JANEIRO IAP SBGL OS 3.1867 Riyadh Mil Apt Saudi A OERY OS 2.5587 Riyadh Mil Apt Saudi A OERY OS 2.5396 ROANOKE RGNLWOODRUM FLD KROA...US NGB NORTHCOM Davis Monthan AFB KDMA AF Arizona US ACC NORTHCOM Davision Army Airfield ARMY Virginia US IMCOM NORTHCOM Des Moines ANG KDSM AF...Carolina US NULL NORTHCOM MCAS New River NAVY North Carolina US NULL NORTHCOM MCAS Yuma KYUM NAVY Arizona US NULL NORTHCOM MCB 29 Palms NAVY

Communication, stereotypes and dignity: the inadequacy of the liberal case against censorship

OpenAIRE

Lucas, Peter

2011-01-01

J. S. Mill’s case against censorship rests on a conception of relevant communications as truth apt. If the communication is true, everyone benefits from the opportunity to exchange error for truth. If it is false, we benefit from the livelier impression truth makes when it collides with error. This classical liberal model is not however adequate for today’s world. In particular, it is inadequate for dealing with the problem of stereotyping. Much contemporary communication is not truth apt. Ad...

Nanosecond Neutron Analysis for the search of the lost Leonardo’s masterpiece, the Battle of Anghiari

Science.gov (United States)

Kuznetsov, A. V.; Gorshkov, I. Yu.; Evsenin, A. V.; Osetrov, O. I.; Vakhtin, D. N.; Cosentino, A.; Seracini, M.

2009-12-01

Between 1505 and 1506 Leonardo Da Vinci painted his masterpiece, the Battle of Anghiari, in Palazzo Vecchio's Hall of 500 in Florence. The unfinished mural remained visible until 1563, when architect Giorgio Vasari undertook a renovation of the Hall and all traces of the Battle of Anghiari were lost. However, scholarly interpretation and scientific evidence suggest that the mural could be on the eastern wall, hidden behind a brick wall built in 1563 by Vasari. This paper discusses the possibility of using NNA/APT (Nanosecond Neutron Analysis/Associated Particle Technique) to establish the presence of the masterpiece by identifying behind the Vasari's wall chemical elements from the gesso preparation layer of the mural and possibly from its pigments. This paper reports on the experiments run with a simple NNA/APT system and the Monte Carlo simulations that have been carried out in order to outline the experimental setup of an advanced NNA/APT able to detect and locate the tiny amount of gesso and pigments.

Nanosecond Neutron Analysis for the search of the lost Leonardo's masterpiece, the Battle of Anghiari

International Nuclear Information System (INIS)

Kuznetsov, A.V.; Gorshkov, I.Yu.; Evsenin, A.V.; Osetrov, O.I.; Vakhtin, D.N.; Cosentino, A.; Seracini, M.

2009-01-01

Between 1505 and 1506 Leonardo Da Vinci painted his masterpiece, the Battle of Anghiari, in Palazzo Vecchio's Hall of 500 in Florence. The unfinished mural remained visible until 1563, when architect Giorgio Vasari undertook a renovation of the Hall and all traces of the Battle of Anghiari were lost. However, scholarly interpretation and scientific evidence suggest that the mural could be on the eastern wall, hidden behind a brick wall built in 1563 by Vasari. This paper discusses the possibility of using NNA/APT (Nanosecond Neutron Analysis/Associated Particle Technique) to establish the presence of the masterpiece by identifying behind the Vasari's wall chemical elements from the gesso preparation layer of the mural and possibly from its pigments. This paper reports on the experiments run with a simple NNA/APT system and the Monte Carlo simulations that have been carried out in order to outline the experimental setup of an advanced NNA/APT able to detect and locate the tiny amount of gesso and pigments.

Carboxylic acid functionalization of halloysite nanotubes for sustained release of diphenhydramine hydrochloride

Energy Technology Data Exchange (ETDEWEB)

Zargarian, S. Sh.; Haddadi-Asl, V., E-mail: haddadi@aut.ac.ir; Hematpour, H. [Amirkabir University of Technology, Department of Polymer Engineering and Color Technology (Iran, Islamic Republic of)

2015-05-15

Halloysite nanotubes (HNT) (cylindrical shape with external diameter and length in the range of 30–80 nm and 0.2–1 µm, respectively) were functionalized with 3-aminopropyltriethoxysilane (APTES) from hydroxyl groups by a coupling reaction. Subsequently, maleic anhydride was attached to the APTES moieties to yield carboxylic acid-functionalized HNT. Loading and subsequent release of a model drug molecule diphenhydramine hydrochloride (DPH) on modified and unmodified nanotubes were investigated. Morphology of HNT was studied by electron microscopy. Successful attachment of APTES and carboxylic acid groups to halloysite and drug loading were evaluated by Fourier transform infrared spectroscopy. The amount of surface modification and drug adsorption capacity were calculated via thermogravimetric analysis. The ordered crystal structure of loaded drug was evaluated by X-ray diffraction. UV–Visible spectrophotometer was used to study drug release from modified and unmodified samples. Carboxylated halloysite exhibits higher loading capacity and prolonged release of DPH as compared to that of the natural halloysite.

Cine club

CERN Multimedia

Cine club

2016-01-01

Wednesday 14 December 2016 at 20:00 CERN Council Chamber Flags of Our Fathers Directed by Clint Eastwood USA, 2006, 135 minutes The life stories of the six men who raised the flag at The Battle of Iwo Jima, a turning point in WWII. Original version English; French subtitles Wednesday 11 January 2017 at 20:00 CERN Council Chamber Seven Up! Directed by Paul Almond UK, 1964, 39 minutes A group of seven-year-old British children from widely ranging backgrounds are interviewed about a range of subjects. Director Michael Apted plans to reinterview them at seven-year intervals to determine how their lives and attitudes have changed.   21 Up Directed by Michael Apted UK, 1977, 100 minutes Director Michael Apted revisits the same group of British-born adults after a seven-year wait. The subjects are interviewed as to the changes that have occurred in their lives during the last seven years. Original version English; French subtitles

Self-assembled gold nanoparticles modified ITO electrodes: The monolayer binder molecule effect

Energy Technology Data Exchange (ETDEWEB)

Ballarin, Barbara; Cassani, Maria Cristina; Scavetta, Erika; Tonelli, Domenica [Dipartimento di Chimica Fisica ed Inorganica, Universita di Bologna, V.le Risorgimento 4, 40136 Bologna, INSTM, UdR Bologna (Italy)

2008-11-15

The fabrication of gold attached organosilane-coated indium tin oxide Au{sub NPs}-MPTMS/ITO and Au{sub NPs}-APTES/ITO electrodes [MPTMS 3-(mercaptopropyl)-trimethoxysilane, APTES = 3-(aminopropyl)-triethoxysilane, ITO = indium tin oxide] was carried out making use of a well-known two-step procedure and the role played by the -SH and -NH{sub 2} functional groups in the two electrodes has been examined and compared using different techniques. Information about particle coverage and inter-particle spacing has been obtained using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) whereas, bulk surface properties have been probed with UV-vis spectroscopy, CV and electrochemical impedance spectroscopy (EIS). The catalytic activity of the two electrodes has been evaluated studying the electrooxidation of methanol in alkaline conditions. The results obtained show that the NH{sub 2} functionality in the APTES binder molecule favours the formation of isle-like Au nanoparticle aggregates that lead to both a higher electron transfer and electrocatalytic activity. (author)

Silane surface modification effects on the electromagnetic properties of phosphatized iron-based SMCs

Science.gov (United States)

Fan, Liang-Fang; Hsiang, Hsing-I.; Hung, Jia-Jing

2018-03-01

It is difficult to achieve homogeneous phosphatized iron powder dispersion in organic resins during the preparation of soft magnetic composites (SMCs). Inhomogeneous iron powder mixing in organic resins generally leads to the formation of micro-structural defects in SMCs and hence causes the magnetic properties to become worse. Phosphatized iron powder dispersion in organic resins can be improved by coating the phosphatized iron powder surfaces with a coupling agent. This study investigated the (3-aminopropyl) triethoxysilane (APTES) surface modification effects on the electromagnetic properties of phosphatized iron-based soft magnetic composites (SMCs). The results showed that the phosphatized iron powder surface can be modified using APTES to improve the phosphatized iron powder and epoxy resin compatibility and hence enhance phosphate iron powder epoxy mixing. The tensile strength, initial permeability, rated current under DC-bias superposition and magnetic loss in SMCs prepared using phosphatized iron powders can be effectively improved using APTES surface modification, which provides a promising candidate for power chip inductor applications.

An amperometric uric acid biosensor based on Bis[sulfosuccinimidyl] suberate crosslinker/3-aminopropyltriethoxysilane surface modified ITO glass electrode

International Nuclear Information System (INIS)

Ahuja, Tarushee; Rajesh; Kumar, Devendra; Tanwar, Vinod Kumar; Sharma, Vikash; Singh, Nahar; Biradar, Ashok M.

2010-01-01

A label free, amperometric uric acid biosensor is described by immobilizing enzyme uricase through a self assembled monolayer (SAM) of 3-aminopropyltriethoxysilane (APTES) using a crosslinker, Bis[sulfosuccinimidyl]suberate (BS 3 ) on an indium-tin-oxide (ITO) coated glass plate. The biosensor (uricase/BS 3 /APTES/ITO) was characterized by, scanning electron microscopy (SEM), atomic force microscopy (AFM) and electrochemical techniques. Chronoamperometric response was measured as a function of uric acid concentration in aqueous solution (pH 7.4). The biosensor shows a linear response over a concentration range of 0.05 to 0.58 mM with a sensitivity of 39.35 μA mM -1 . The response time is 50 s reaching to a 95% steady state current value and about 90% of enzyme activity is retained for about 7 weeks. These results indicate an efficient binding of enzyme with the crosslinker over the surface of APTES modified ITO glass plates, which leads to an improved sensitivity and shelf life of the biosensor.

Carboxylic acid functionalization of halloysite nanotubes for sustained release of diphenhydramine hydrochloride

International Nuclear Information System (INIS)

Zargarian, S. Sh.; Haddadi-Asl, V.; Hematpour, H.

2015-01-01

Halloysite nanotubes (HNT) (cylindrical shape with external diameter and length in the range of 30–80 nm and 0.2–1 µm, respectively) were functionalized with 3-aminopropyltriethoxysilane (APTES) from hydroxyl groups by a coupling reaction. Subsequently, maleic anhydride was attached to the APTES moieties to yield carboxylic acid-functionalized HNT. Loading and subsequent release of a model drug molecule diphenhydramine hydrochloride (DPH) on modified and unmodified nanotubes were investigated. Morphology of HNT was studied by electron microscopy. Successful attachment of APTES and carboxylic acid groups to halloysite and drug loading were evaluated by Fourier transform infrared spectroscopy. The amount of surface modification and drug adsorption capacity were calculated via thermogravimetric analysis. The ordered crystal structure of loaded drug was evaluated by X-ray diffraction. UV–Visible spectrophotometer was used to study drug release from modified and unmodified samples. Carboxylated halloysite exhibits higher loading capacity and prolonged release of DPH as compared to that of the natural halloysite

NANOBIOCATALYTIC SYSTEMS BASED ON LIPASE-Fe3O4 AND CONVENTIONAL SYSTEMS FOR ISONIAZID SYNTHESIS: A COMPARATIVE STUDY

Directory of Open Access Journals (Sweden)

V. M. Costa

Full Text Available Abstract Superparamagnetic nanomaterials have attracted interest in many areas due to the high saturation magnetization and surface area. For enzyme immobilization, these properties favor the enzyme-support contact during the immobilization reaction and easy separation from the reaction mixture by use of low-cost magnetic processes. Iron oxide magnetic nanoparticles (Fe3O4, MNPs, produced by the co-precipitation method, functionalized with 3-aminopropyltriethoxysilane (APTES and glutaraldehyde (GLU, were evaluated as a solid support for Candida antarctica lipase B (CALB immobilization. The nanomagnetic derivative (11nm obtained after CALB immobilization (MNPs/APTES/GLU/CALB was evaluated as biocatalyst in isoniazide (INH synthesis using ethyl isonicotinate (INE and hydrazine hydrate (HID as substrates, in 1,4-dioxane. The results showed that MNPs/APTES/CALB had a similar performance when compared to a commercial enzyme Novozym 435, showing significant advantages over other biocatalysts, such as Rhizhomucor miehei lipase (RML and CALB immobilized on non-conventional, low-cost, chitosan-based supports.

Understanding Atom Probe Tomography of Oxide-Supported Metal Nanoparticles by Correlation with Atomic-Resolution Electron Microscopy and Field Evaporation Simulation.

Science.gov (United States)

Devaraj, Arun; Colby, Robert; Vurpillot, François; Thevuthasan, Suntharampillai

2014-04-17

Oxide-supported metal nanoparticles are widely used in heterogeneous catalysis. The increasingly detailed design of such catalysts necessitates three-dimensional characterization with high spatial resolution and elemental selectivity. Laser-assisted atom probe tomography (APT) is uniquely suited to the task but faces challenges with the evaporation of metal/insulator systems. Correlation of APT with aberration-corrected scanning transmission electron microscopy (STEM), for Au nanoparticles embedded in MgO, reveals preferential evaporation of the MgO and an inaccurate assessment of nanoparticle composition. Finite element field evaporation modeling is used to illustrate the evolution of the evaporation front. Nanoparticle composition is most accurately predicted when the MgO is treated as having a locally variable evaporation field, indicating the importance of considering laser-oxide interactions and the evaporation of various molecular oxide ions. These results demonstrate the viability of APT for analysis of oxide-supported metal nanoparticles, highlighting the need for developing a theoretical framework for the evaporation of heterogeneous materials.

BUILDING BLOCKS: ENMESHING TECHNOLOGY AND CREATIVITY WITH ARTISTIC PEDAGOGICAL TECHNOLOGIES

Directory of Open Access Journals (Sweden)

Katherine J.JANZEN

2017-01-01

Full Text Available Using the analogy of children’s building blocks, the reader is guided through the results of a research study that explored the use of three Artistic Pedagogical Technologies (APTs. ‘Building blocks’ was the major theme that emerged from the data. Sub-themes included developing community, enhancing creativity, and risk taking. The discourse of the paper centers on how selected APTs stimulate interaction, create social presence, and help develop community in the online post-secondary classroom. Additional findings are discussed and implications are presented.

Comparing models of offensive cyber operations

CSIR Research Space (South Africa)

Grant, T

2012-03-01

Full Text Available Group Fallback only No Damballa, 2008 Crime Case studies Lone No No Owens et al, 2009 Warfare Literature Group Yes Yes Croom, 2010 Crime (APT) Case studies Group No No Dreijer, 2011 Warfare Previous models and case studies Group Yes No Van... be needed by a geographically or functionally distributed group of attackers. While some of the models describe the installation of a backdoor or an advanced persistent threat (APT), none of them describe the behaviour involved in returning to a...

Expert knowledge and data analysis for detecting advanced persistent threats

Directory of Open Access Journals (Sweden)

Moya Juan Ramón

2017-08-01

Full Text Available Critical Infrastructures in public administration would be compromised by Advanced Persistent Threats (APT which today constitute one of the most sophisticated ways of stealing information. This paper presents an effective, learning based tool that uses inductive techniques to analyze the information provided by firewall log files in an IT infrastructure, and detect suspicious activity in order to mark it as a potential APT. The experiments have been accomplished mixing real and synthetic data traffic to represent different proportions of normal and anomalous activity.

Research and application of nanotechnology in transportation

CSIR Research Space (South Africa)

Steyn, WJvdM

2008-07-01

Full Text Available OF TEMPERATURE CONDITIONS ON APT OF HMA MIXES Final date: 3 June 2008 4 081 words 5 Figures 1 Table WJvdM STEYN CSIR Built Environment / Department of Civil Engineering, Tshwane University of Technology PO Box 395 / Private Bag X680 Pretoria... it to Accelerated Pavement Testing (APT) to ensure that correct inferences are drawn from the response of the layer during testing. A further complication in the behavior is the effect of temperature on the loading conditions of the test, specifically through...

Modification of polyelectrolyte microcapsules into a container for the low molecular weight compounds

Science.gov (United States)

Goryacheva, O. A.; Gao, H.; Sukhorukov, G. B.

2018-04-01

Polyelectrolyte microcapsules are one of the most successful developments in the direction of target drug delivery. Nevertheless, to encapsulate low molecular weight compounds and to deliver the targeted drugs it is necessary to modify the surface of the microcapsules. Silica nanostructures obtained as result of hydrolysis of (3-Aminopropyl)- triethoxysilane (APTES) were used for the modification of the microcapsules. This material shows no toxic effect on cells and is capable of biodegradation. Amino-groups in the structure of APTES make it possible for further direct bioconjugation.

Hydrophobicity attainment and wear resistance enhancement on glass substrates by atmospheric plasma-polymerization of mixtures of an aminosilane and a fluorocarbon

Energy Technology Data Exchange (ETDEWEB)

Múgica-Vidal, Rodolfo, E-mail: rodolfo.mugica@alum.unirioja.es [Department of Mechanical Engineering, University of La Rioja, c/ Luis de Ulloa 20, 26004, Logroño, La Rioja (Spain); Alba-Elías, Fernando, E-mail: fernando.alba@unirioja.es [Department of Mechanical Engineering, University of La Rioja, c/ Luis de Ulloa 20, 26004, Logroño, La Rioja (Spain); Sainz-García, Elisa, E-mail: elisa.sainzg@unirioja.es [Department of Mechanical Engineering, University of La Rioja, c/ Luis de Ulloa 20, 26004, Logroño, La Rioja (Spain); Pantoja-Ruiz, Mariola, E-mail: mpruiz@ing.uc3m.es [Materials Science and Engineering Department, IAAB, Materials Performance Group, University Carlos III of Madrid, Av. Universidad 30, 28911, Leganés, Madrid (Spain)

2015-08-30

Graphical abstract: - Highlights: • APTES and PFH were used to coat glass by non-thermal atmospheric jet plasma. • A mixture of 75% of APTES and 25% PFH produced the best sample of this work. • Hydrophobicity was achieved by changes in surface morphology and chemistry. • Wear resistance was enhanced by the formation of siloxane groups. - Abstract: Mixtures of different proportions of two liquid precursors were subjected to plasma-polymerization by a non-thermal atmospheric jet plasma system in a search for a coating that achieves a hydrophobic character on a glass substrate and enhances its wear resistance. 1-Perfluorohexene (PFH) was chosen as a low-surface-energy precursor to promote a hydrophobic character. Aminopropyltriethoxysilane (APTES) was chosen for its contribution to the improvement of wear resistance by the formation of siloxane bonds. The objective of this work was to determine which of the precursors’ mixtures that were tested provides the coating with the most balanced enhancement of both hydrophobicity and wear resistance, given that coatings deposited with fluorocarbon-based precursors such as PFH are usually low in resistance to wear and coatings deposited with APTES are generally hydrophilic. The coatings obtained were analyzed by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Fourier Transform Infra-Red (FTIR) spectroscopy, X-ray Photoelectron Spectroscopy (XPS), static Water Contact Angle (WCA) measurements, tribological ball-on-disc tests and contact profilometry. A relationship between the achievement of a hydrophobic character and the modifications to roughness and surface morphology and the incorporation of fluorocarbon groups in the surface chemistry was observed. Also, it was seen that the wear resistance was influenced by the SiOSi content of the coatings. In turn, the SiOSi content appears to be directly related to the percentage of APTES used in the mixture of precursors. The best conjunction of

Assessment of MRI Parameters as Imaging Biomarkers for Radiation Necrosis in the Rat Brain

Energy Technology Data Exchange (ETDEWEB)

Wang Silun [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Tryggestad, Erik [Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Zhou Tingting [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Armour, Michael [Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Wen Zhibo [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong (China); Fu Dexue [Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Ford, Eric [Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Zijl, Peter C.M. van [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland (United States); Zhou Jinyuan, E-mail: jzhou@mri.jhu.edu [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland (United States)

2012-07-01

Purpose: Radiation necrosis is a major complication of radiation therapy. We explore the features of radiation-induced brain necrosis in the rat, using multiple MRI approaches, including T{sub 1}, T{sub 2}, apparent diffusion constant (ADC), cerebral blood flow (CBF), magnetization transfer ratio (MTR), and amide proton transfer (APT) of endogenous mobile proteins and peptides. Methods and Materials: Adult rats (Fischer 344; n = 15) were irradiated with a single, well-collimated X-ray beam (40 Gy; 10 Multiplication-Sign 10 mm{sup 2}) in the left brain hemisphere. MRI was acquired on a 4.7-T animal scanner at {approx}25 weeks' postradiation. The MRI signals of necrotic cores and perinecrotic regions were assessed with a one-way analysis of variance. Histological evaluation was accomplished with hematoxylin and eosin staining. Results: ADC and CBF MRI could separate perinecrotic and contralateral normal brain tissue (p < 0.01 and < 0.05, respectively), whereas T{sub 1}, T{sub 2}, MTR, and APT could not. MRI signal intensities were significantly lower in the necrotic core than in normal brain for CBF (p < 0.001) and APT (p < 0.01) and insignificantly higher or lower for T{sub 1}, T{sub 2}, MTR, and ADC. Histological results demonstrated coagulative necrosis within the necrotic core and reactive astrogliosis and vascular damage within the perinecrotic region. Conclusion: ADC and CBF are promising imaging biomarkers for identifying perinecrotic regions, whereas CBF and APT are promising for identifying necrotic cores.

Development of a New Aprepitant Liquisolid Formulation with the Aid of Artificial Neural Networks and Genetic Programming.

Science.gov (United States)

Barmpalexis, Panagiotis; Grypioti, Agni; Eleftheriadis, Georgios K; Fatouros, Dimitris G

2018-02-01

In the present study, liquisolid formulations were developed for improving dissolution profile of aprepitant (APT) in a solid dosage form. Experimental studies were complemented with artificial neural networks and genetic programming. Specifically, the type and concentration of liquid vehicle was evaluated through saturation-solubility studies, while the effect of the amount of viscosity increasing agent (HPMC), the type of wetting (Soluplus® vs. PVP) and solubilizing (Poloxamer®407 vs. Kolliphor®ELP) agents, and the ratio of solid coating (microcrystalline cellulose) to carrier (colloidal silicon dioxide) were evaluated based on in vitro drug release studies. The optimum liquisolid formulation exhibited improved dissolution characteristics compared to the marketed product Emend®. X-ray diffraction (XRD), scanning electron microscopy (SEM) and a novel method combining particle size analysis by dynamic light scattering (DLS) and HPLC, revealed that the increase in dissolution rate of APT in the optimum liquisolid formulation was due to the formation of stable APT nanocrystals. Differential scanning calorimetry (DSC) and attenuated total reflection FTIR spectroscopy (ATR-FTIR) revealed the presence of intermolecular interactions between APT and liquisolid formulation excipients. Multilinear regression analysis (MLR), artificial neural networks (ANNs), and genetic programming (GP) were used to correlate several formulation variables with dissolution profile parameters (Y 15min and Y 30min ) using a full factorial experimental design. Results showed increased correlation efficacy for ANNs and GP (RMSE of 0.151 and 0.273, respectively) compared to MLR (RMSE = 0.413).

GETDB: 112112 [GETDB

Lifescience Database Archive (English)

Full Text Available 112112 Link to Original y[*] w[*]; P{GawB}NP0256 / CyO, P{UAS-lacZ.UW14}UW14 59F1 ;... -; 59F4 Link to DGRC Genome Viewer: 112112 CG30184 apt 256 2 FlyBase Insertion: P{GawB}NP0256 NP line. Rece... Request - a small # of cells no gfp signal weak, mg - - - - - - - - Show 112112 DGRC Number 112112...Site 59F1 ; -; 59F4 Map Viewer Link to DGRC Genome Viewer: 112112 Related Genes CG30184 apt Original Number

Neuroscience is Bad

DEFF Research Database (Denmark)

Presskorn-Thygesen, Thomas

The title is telling: I will argue first that ‘traditional’ cognitive neuroscience is conceptually flawed and secondly – as an open question – inquire whether theories of brain plasticity are scientifically more sound and more apt to enter into collaboration with the social sciences. The ascripti......The title is telling: I will argue first that ‘traditional’ cognitive neuroscience is conceptually flawed and secondly – as an open question – inquire whether theories of brain plasticity are scientifically more sound and more apt to enter into collaboration with the social sciences...

In-situ analysis of redistribution of carbon and nitrogen during tempering of low interstitial martensitic stainless steel

DEFF Research Database (Denmark)

Niessen, F.; Villa, M.; Danoix, F.

2018-01-01

The redistribution of C and N during tempering of X4CrNiMo16-5-1 martensitic stainless steel containing 0.034 wt% C and 0.032 wt% N was studied using in-situ synchrotron X-ray diffraction (XRD) and atom probe tomography (APT). The unit cell volume of martensite decreased continuously during...... tempering. APT showed that this volume decrease is accounted entirely for by segregation of the interstitial atoms, implying that in low interstitial martensitic stainless steel stress relaxation only contributes negligibly to changes in the martensite unit cell volume....

Special issue of Higher-Order and Symbolic Computation

DEFF Research Database (Denmark)

Danvy, Olivier

, they should have a large range of applicability for a large class of specifications or programs. Only general ideas could become the basis for an automatic system for program development. Bob’s APTS system is indeed the incarnation of most of the techniques he proposed (cf. Leonard and Heitmeyer...... specification, expressed in SCR notation, into C. Two translation strategies are discussed in the paper. Both were implemented using Bob Paige’s APTS programtransformation system. “Computational Divided Differencing and Divided-Difference Arithmetics” uses an approach conceptually similar to the Computational...

Comparison of tritium production facilities

International Nuclear Information System (INIS)

He Kaihui; Huang Jinhua

2002-01-01

Detailed investigation and research on the source of tritium, tritium production facilities and their comparison are presented based on the basic information about tritium. The characteristics of three types of proposed tritium production facilities, i.e., fissile type, accelerator production tritium (APT) and fusion type, are presented. APT shows many advantages except its rather high cost; fusion reactors appear to offer improved safety and environmental impacts, in particular, tritium production based on the fusion-based neutron source costs much lower and directly helps the development of fusion energy source

Aperture Photometry Tool

Science.gov (United States)

Laher, Russ R.; Gorjian, Varoujan; Rebull, Luisa M.; Masci, Frank J.; Fowler, John W.; Helou, George; Kulkarni, Shrinivas R.; Law, Nicholas M.

2012-07-01

Aperture Photometry Tool (APT) is software for astronomers and students interested in manually exploring the photometric qualities of astronomical images. It is a graphical user interface (GUI) designed to allow the image data associated with aperture photometry calculations for point and extended sources to be visualized and, therefore, more effectively analyzed. The finely tuned layout of the GUI, along with judicious use of color-coding and alerting, is intended to give maximal user utility and convenience. Simply mouse-clicking on a source in the displayed image will instantly draw a circular or elliptical aperture and sky annulus around the source and will compute the source intensity and its uncertainty, along with several commonly used measures of the local sky background and its variability. The results are displayed and can be optionally saved to an aperture-photometry-table file and plotted on graphs in various ways using functions available in the software. APT is geared toward processing sources in a small number of images and is not suitable for bulk processing a large number of images, unlike other aperture photometry packages (e.g., SExtractor). However, APT does have a convenient source-list tool that enables calculations for a large number of detections in a given image. The source-list tool can be run either in automatic mode to generate an aperture photometry table quickly or in manual mode to permit inspection and adjustment of the calculation for each individual detection. APT displays a variety of useful graphs with just the push of a button, including image histogram, x and y aperture slices, source scatter plot, sky scatter plot, sky histogram, radial profile, curve of growth, and aperture-photometry-table scatter plots and histograms. APT has many functions for customizing the calculations, including outlier rejection, pixel “picking” and “zapping,” and a selection of source and sky models. The radial-profile-interpolation source

The physical mechanism on the threshold voltage temperature stability improvement for GaN HEMTs with pre-fluorination argon treatment

Energy Technology Data Exchange (ETDEWEB)

Wang, Yun-Hsiang [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 119260 (Singapore); A*STAR Institute of Microelectronics, Singapore 117685 (Singapore); Liang, Yung C., E-mail: chii@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 119260 (Singapore); National University of Singapore (Suzhou) Research Institute, Suzhou 215123 (China); Samudra, Ganesh S. [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 119260 (Singapore); Huang, Chih-Fang [Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Kuo, Wei-Hung [Industrial Technology Research Institute, Chutung 31040, Taiwan (China); Lo, Guo-Qiang [A*STAR Institute of Microelectronics, Singapore 117685 (Singapore)

2016-06-06

In this paper, a normally-off AlGaN/GaN MIS-HEMT with improved threshold voltage (V{sub TH}) thermal stability is reported with investigations on its physical mechanism. The normally-off operation of the device is achieved from novel short argon plasma treatment (APT) prior to the fluorine plasma treatment (FPT) on Al{sub 2}O{sub 3} gate dielectrics. For the MIS-HEMT with FPT only, its V{sub TH} drops from 4.2 V at room temperature to 0.5 V at 200 °C. Alternatively, for the device with APT-then-FPT process, its V{sub TH} can retain at 2.5 V at 200 °C due to the increased amount of deep-level traps that do not emit electrons at 200 °C. This thermally stable V{sub TH} makes this device suitable for high power applications. The depth profile of the F atoms in Al{sub 2}O{sub 3}, measured by the secondary ion mass spectroscopy, reveals a significant increase in the F concentration when APT is conducted prior to FPT. The X-ray photoelectron spectroscopy (XPS) analysis on the plasma-treated Al{sub 2}O{sub 3} surfaces observes higher composition of Al-F bonds if APT was applied before FPT. The enhanced breaking of Al-O bonds due to Ar bombardment assisted in the increased incorporation of F radicals at the surface during the subsequent FPT process. The Schrödinger equation of Al{sub 2}O{sub x}F{sub y} cells, with the same Al-F compositions as obtained from XPS, was solved by Gaussian 09 molecular simulations to extract electron state distribution as a function of energy. The simulation results show creation of the deeper trap states in the Al{sub 2}O{sub 3} bandgap when APT is used before FPT. Finally, the trap distribution extracted from the simulations is verified by the gate-stress experimental characterization to confirm the physical mechanism described.

Covalent attachment of aptamer onto nanocomposite as a high performance electrochemical sensing platform: Fabrication of an ultra-sensitive ibuprofen electrochemical aptasensor

Energy Technology Data Exchange (ETDEWEB)

Roushani, Mahmoud, E-mail: mahmoudroushani@yahoo.com; Shahdost-fard, Faezeh

2016-11-01

In the present study, we report a selective electrochemical aptasensor for the ultrasensitive detection of an anti-inflammatory drug, ibuprofen (IBP). The proposed system was achieved by the modification of a glassy carbon electrode (GCE) with multiwalled carbon nanotubes/ionic liquid/chitosan (MWCNTs/IL/Chit) nanocomposite and the covalent immobilization of the IBP specific aptamer (Apt) onto the modified electrode surface followed by methylene blue (MB) intercalated onto the Apt as the electrochemical redox marker. Upon the incubation of the IBP as a target in the proposed aptasensor, the peak current of MB decreases due to the formation of the Apt-IBP complex and the displacement of MB from the immobilized Apt onto the modified electrode surface. The nanocomposite not only increases the electrode surface area and accelerate the electron transfer kinetics but also it provides a highly stable matrix to enhance the loading amount of the Apt DNA sequence. Through differential pulse voltammetry (DPV) experiments, it was found that the proposed aptasensor could detect the IBP with a linear range (70 pM up to 6 μM) and the detection limit (LOD) as low as 20 pM. The results showed that the aptasensor had good sensitivity, stability, reproducibility, and specificity to detect the IBP. The proposed aptasensor was successfully applied for measuring the IBP concentration in real samples. Based on our experiments we can say that the present method proposes new horizons for the development of other aptasensors for diagnostic application in biosensing. - Highlights: • An electrochemical aptasensor is developed for ultrasensitive detection of IBP. • The aptasensor is made by covalent immobilization of aptamer on a modified GCE. • A nanocomposite as a modifier provides a specific surface with high conductivity. • This nanocomposite leads to a high density of the DNA sequence on the GCE surface. • This method proposes new horizons for development other aptasensors for

Combination treatment of r-tPA and an optimized human apyrase reduces mortality rate and hemorrhagic transformation 6h after ischemic stroke in aged female rats.

Science.gov (United States)

Tan, Zhenjun; Li, Xinlan; Turner, Ryan C; Logsdon, Aric F; Lucke-Wold, Brandon; DiPasquale, Kenneth; Jeong, Soon Soeg; Chen, Ridong; Huber, Jason D; Rosen, Charles L

2014-09-05

Recombinant tissue plasminogen activator (r-tPA) is the only FDA-approved drug treatment for ischemic stroke and must be used within 4.5h. Thrombolytic treatment with r-tPA has deleterious effects on the neurovascular unit that substantially increases the risk of intracerebral hemorrhage if administered too late. These therapeutic shortcomings necessitate additional investigation into agents that can extend the therapeutic window for safe use of thrombolytics. In this study, combination of r-tPA and APT102, a novel form of human apyrase/ADPase, was investigated in a clinically-relevant aged-female rat embolic ischemic stroke model. We propose that successfully extending the therapeutic window of r-tPA administration would represent a significant advance in the treatment of ischemic stroke due to a significant increase in the number of patients eligible for treatment. Results of our study showed significantly reduced mortality from 47% with r-tPA alone to 16% with co-administration of APT102 and r-tPA. Co-administration decreased cortical (47 ± 5% vs. 29 ± 5%), striatal (50 ± 2%, vs. 40 ± 3%) and total (48 ± 3%vs. 33 ± 4%) hemispheric infarct volume compared to r-tPA alone. APT102 improved neurological outcome (8.9±0.6, vs. 6.8 ± 0.8) and decreased hemoglobin extravasation in cortical tissue (1.9 ± 0.1mg/dl vs. 1.4 ± 0.1mg/dl) striatal tissue (2.1 ± 0.3mg/dl vs. 1.4 ± 0.1mg/dl) and whole brain tissue (2.0 ± 0.2mg/dl vs. 1.4 ± 0.1mg/dl). These data suggest that APT102 can safely extend the therapeutic window for r-tPA mediated reperfusion to 6h following experimental stroke without increased hemorrhagic transformation. APT102 offers to be a viable adjunct therapeutic option to increase the number of clinical patients eligible for thrombolytic treatment after ischemic stroke. Copyright © 2014 Elsevier B.V. All rights reserved.

Covalent attachment of aptamer onto nanocomposite as a high performance electrochemical sensing platform: Fabrication of an ultra-sensitive ibuprofen electrochemical aptasensor

International Nuclear Information System (INIS)

Roushani, Mahmoud; Shahdost-fard, Faezeh

2016-01-01

In the present study, we report a selective electrochemical aptasensor for the ultrasensitive detection of an anti-inflammatory drug, ibuprofen (IBP). The proposed system was achieved by the modification of a glassy carbon electrode (GCE) with multiwalled carbon nanotubes/ionic liquid/chitosan (MWCNTs/IL/Chit) nanocomposite and the covalent immobilization of the IBP specific aptamer (Apt) onto the modified electrode surface followed by methylene blue (MB) intercalated onto the Apt as the electrochemical redox marker. Upon the incubation of the IBP as a target in the proposed aptasensor, the peak current of MB decreases due to the formation of the Apt-IBP complex and the displacement of MB from the immobilized Apt onto the modified electrode surface. The nanocomposite not only increases the electrode surface area and accelerate the electron transfer kinetics but also it provides a highly stable matrix to enhance the loading amount of the Apt DNA sequence. Through differential pulse voltammetry (DPV) experiments, it was found that the proposed aptasensor could detect the IBP with a linear range (70 pM up to 6 μM) and the detection limit (LOD) as low as 20 pM. The results showed that the aptasensor had good sensitivity, stability, reproducibility, and specificity to detect the IBP. The proposed aptasensor was successfully applied for measuring the IBP concentration in real samples. Based on our experiments we can say that the present method proposes new horizons for the development of other aptasensors for diagnostic application in biosensing. - Highlights: • An electrochemical aptasensor is developed for ultrasensitive detection of IBP. • The aptasensor is made by covalent immobilization of aptamer on a modified GCE. • A nanocomposite as a modifier provides a specific surface with high conductivity. • This nanocomposite leads to a high density of the DNA sequence on the GCE surface. • This method proposes new horizons for development other aptasensors for

Improved mechanical properties of hydroxyapatite whisker-reinforced poly(L-lactic acid) scaffold by surface modification of hydroxyapatite.

Science.gov (United States)

Fang, Zhou; Feng, Qingling

2014-02-01

To improve the mechanical properties of porous hydroxyapatite/poly(L-lactic acid) (HA/PLLA) composites, HA whiskers with high crystallinity and high aspect ratio were synthesized. HA whiskers were modified with γ-aminopropyltriethoxysilane (APTES) to improve the interface between HA whiskers and PLLA. The composite scaffold consists of a porous PLLA matrix with HA whiskers distributed homogeneously. The morphology and the distributions of pore sizes of PLLA scaffold was not influenced by introducing HA whiskers, while the mechanical properties were improved. Both the compressive strength and compressive modulus were increased with the weight ratio of APTES-modified HA whiskers up to 30 wt.%, but only up to 15 wt.% for non-modified HA whiskers. With more than 15 wt.% HA whiskers, the mechanical properties of HA/PLLA scaffold were better improved with APTES-modified HA whiskers than non-modified. The HA whisker/PLLA scaffold with high porosity and improved mechanical properties is attractive in the application of tissue engineering. Copyright © 2013 Elsevier B.V. All rights reserved.

The acid perfusion test in gastroesophageal reflux disease

International Nuclear Information System (INIS)

Kaul, B.; Petersen, H.; Grette, K.; Myrvold, H.E.

1986-01-01

An acid perfusion test, isotope scanning, endoscopy, and esophageal biopsy were performed in 101 patients with symptoms strongly suggestive of gastroesophageal reflux (GER) disease. A positive acid perfusion test within 30 min (APT) and within 5 min (TAPT) was found in 70.2% and 37.6% of the patients, respectively. A positive APT was found significantly more often in patients with than without endoscopic esophagitis, whereas a positive TAPT was found significantly more often in patients with severe symptoms than in patients with moderate symptoms, and in a significantly higher proportion of patients with than without GER by scintigraphy. Neither the APT nor the TAPT showed any dependency on the presence of histologic esophagitis. Most (97%) patients with a negative acid perfusion test, in addition to typical symptoms, also presented with scintigraphic, endoscopic, or histologic evidence of GER disease. Although it shows that the acid perfusion test, particularly when early positive, may serve as a weak predictor of the severity of GER disease, the present study gives little support to the test's clinical usefulness

Solution-Processable transparent conducting electrodes via the self-assembly of silver nanowires for organic photovoltaic devices.

Science.gov (United States)

Tugba Camic, B; Jeong Shin, Hee; Hasan Aslan, M; Basarir, Fevzihan; Choi, Hyosung

2018-02-15

Solution-processed transparent conducting electrodes (TCEs) were fabricated via the self-assembly deposition of silver nanowires (Ag NWs). Glass substrates modified with (3-aminopropyl)triethoxysilane (APTES) and (3-mercaptopropyl)trimethoxysilane (MPTES) were coated with Ag NWs for various deposition times, leading to three different Ag NWs samples (APTES-Ag NWs (PVP), MPTES-Ag NWs (PVP), and APTES-Ag NWs (COOH)). Controlling the deposition time produced Ag NWs monolayer thin films with different optical transmittance and sheet resistance. Post-annealing treatment improved their electrical conductivity. The Ag NWs films were successfully characterized using UV-Vis spectroscopy, field emission scanning electron microscopy, optical microscopy and four-point probe. Three Ag NWs films exhibited low sheet resistance of 4-19Ω/sq and high optical transmittance of 65-81% (at 550nm), which are comparable to those of commercial ITO electrode. We fabricated an organic photovoltaic device by using Ag NWs as the anode instead of ITO electrode, and optimized device with Ag NWs exhibited power conversion efficiency of 1.72%. Copyright © 2017 Elsevier Inc. All rights reserved.

Nanosecond Neutron Analysis for the search of the lost Leonardo's masterpiece, the Battle of Anghiari

Energy Technology Data Exchange (ETDEWEB)

Kuznetsov, A.V.; Gorshkov, I.Yu.; Evsenin, A.V.; Osetrov, O.I.; Vakhtin, D.N. [Applied Science and Technology Center (APSTEC Ltd.), Office 213, Gzhatskaya, 27, Saint-Petersburg 195220 (Russian Federation); Cosentino, A., E-mail: tonycosentino@yahoo.i [CISA3, Center of Interdisciplinary Science for Art, Architecture and Archaeology, University of California, San Diego, 9500 Gilman Dr. La Jolla, CA 92093-0436 (United States); Seracini, M. [CISA3, Center of Interdisciplinary Science for Art, Architecture and Archaeology, University of California, San Diego, 9500 Gilman Dr. La Jolla, CA 92093-0436 (United States)

2009-12-15

Between 1505 and 1506 Leonardo Da Vinci painted his masterpiece, the Battle of Anghiari, in Palazzo Vecchio's Hall of 500 in Florence. The unfinished mural remained visible until 1563, when architect Giorgio Vasari undertook a renovation of the Hall and all traces of the Battle of Anghiari were lost. However, scholarly interpretation and scientific evidence suggest that the mural could be on the eastern wall, hidden behind a brick wall built in 1563 by Vasari. This paper discusses the possibility of using NNA/APT (Nanosecond Neutron Analysis/Associated Particle Technique) to establish the presence of the masterpiece by identifying behind the Vasari's wall chemical elements from the gesso preparation layer of the mural and possibly from its pigments. This paper reports on the experiments run with a simple NNA/APT system and the Monte Carlo simulations that have been carried out in order to outline the experimental setup of an advanced NNA/APT able to detect and locate the tiny amount of gesso and pigments.

300 Area Process Trenches Postclosure Plan

International Nuclear Information System (INIS)

Badden, J.W.

1998-05-01

The 300 Area Process Trenches (300 APT) certified closure under a modified closure option and in compliance with Condition II.K.3 oft he Hartford Facility Dangerous Waste Permit (Penit) (Ecology 1994). Modified closure has been determined to be the appropriate closure option for this unit due to groundwater that remains contaminated from past operations at the 300 APT. Corrective actions required for dangerous waste constituents remaining in groundwater will occur pursuant to the 300 APT Resource Conservation and Recovery Act (RCRA) Final Status Facility Ground Water Monitoring Plan, the Hanford Site Wide Dangerous Waste Permit, and in conjunction with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) remedial actions at the 300-FF-5 Groundwater Operable Unit (OU) pursuant to the Record of Decision (ROD) (EPA 1996). This postclosure plan identifies the modified closure actions required at the unit under postclosure care. It contains a description of the unit, past closure actions, and postclosure care requirements subject to compliance under the Permit (condition II.K.3)

Gold atomic cluster mediated electrochemical aptasensor for the detection of lipopolysaccharide.

Science.gov (United States)

Posha, Biyas; Nambiar, Sindhu R; Sandhyarani, N

2018-03-15

We have constructed an aptamer immobilized gold atomic cluster mediated, ultrasensitive electrochemical biosensor (Apt/AuAC/Au) for LPS detection without any additional signal amplification strategy. The aptamer self-assemble onto the gold atomic clusters makes Apt/AuAC/Au an excellent platform for the LPS detection. Differential pulse voltammetry and EIS were used for the quantitative LPS detection. The Apt/AuAC/Au sensor offers an ultrasensitive and selective detection of LPS down to 7.94 × 10 -21 M level with a wide dynamic range from 0.01 attomolar to 1pM. The sensor exhibited excellent selectivity and stability. The real sample analysis was performed by spiking the diluted insulin sample with various concentration of LPS and obtained recovery within 2% error value. The sensor is found to be more sensitive than most of the literature reports. The simple and easy way of construction of this sensor provides an efficient and promising detection of an even trace amount of LPS. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of Radiation-Induced Clustering using Atom Probe Tomography in Nuclear Structural Materials

Energy Technology Data Exchange (ETDEWEB)

Lee, Gyeong Geun; Lim, Sang Yeob; Chang, Kun Ok; Ha, Jin Hyung; Kwon, Jun Hyun [KAERI, Daejeon (Korea, Republic of)

2016-05-15

The degradations include the change in mechanical properties, which are related to the microstructure evolution caused by irradiation. The most widely used tool for the imaging irradiated microstructure is transmission electron microscopy (TEM). The composition of irradiation defects can be analyzed using X-ray spectroscopy (EDS) equipped in the TEM. However, composition characterization of the nano-sized irradiation defects in the matrix is limited due to the beam broadening of TEM and the overlapping of the probed volume during EDS analysis. Recently, Atom probe tomography (APT) has been introduced to the characterization of irradiation defects. APT provides sub-nano scale position of atoms and the chemical composition of a selected volume. SS316 irradiated with Fe ions at above 300 .deg. C caused significant clustering and segregation of Si and Ni at defect sinks. The neutron irradiated low alloy steel showed similar clustering of Ni and Si. The approach of using APT was demonstrated to be well suited for discovering the structure of irradiation defects and performing quantitative analysis in nuclear materials irradiated at high temperature.

New immobilisation protocol for the template used in solid-phase synthesis of MIP nanoparticles

Science.gov (United States)

Chen, Lu; Muhammad, Turghun; Yakup, Burabiye; Piletsky, Sergey A.

2017-06-01

As a novel imprinting method, solid-phase synthesis has proven to be a promising approach to prepare polymer nanoparticles with specific recognition sites for a template molecule. In this method, imprinted polymer nanoparticles were synthesized using template immobilized on a solid support. Herein, preparation of immobilized templates on quartz chips through homogeneous route was reported as an efficient alternative strategy to heterogeneous one. The template molecule indole-3-butyric acid (IBA) was reacted with 3-aminopropyltriethoxysilane (APTES) to produce silylated template (IBA-APTES), and it was characterized by IR, 1H NMR and GC-MS. Then, the silylated template molecule was grafted onto the activated surfaces of quartz chip to prepare immobilized template (SiO2@IBA-APTES). The immobilization was confirmed by contact angle, XPS, UV and fluorescence measurement. Immobilization protocol has shown good reproducibility and stability of the immobilized template. MIP nanoparticles were prepared with high selectivity toward the molecule immobilized onto the solid surface. This provides a new approach for the development of molecularly imprinted nanoparticles.

Pulsed-voltage atom probe tomography of low conductivity and insulator materials by application of ultrathin metallic coating on nanoscale specimen geometry.

Science.gov (United States)

Adineh, Vahid R; Marceau, Ross K W; Chen, Yu; Si, Kae J; Velkov, Tony; Cheng, Wenlong; Li, Jian; Fu, Jing

2017-10-01

We present a novel approach for analysis of low-conductivity and insulating materials with conventional pulsed-voltage atom probe tomography (APT), by incorporating an ultrathin metallic coating on focused ion beam prepared needle-shaped specimens. Finite element electrostatic simulations of coated atom probe specimens were performed, which suggest remarkable improvement in uniform voltage distribution and subsequent field evaporation of the insulated samples with a metallic coating of approximately 10nm thickness. Using design of experiment technique, an experimental investigation was performed to study physical vapor deposition coating of needle specimens with end tip radii less than 100nm. The final geometries of the coated APT specimens were characterized with high-resolution scanning electron microscopy and transmission electron microscopy, and an empirical model was proposed to determine the optimal coating thickness for a given specimen size. The optimal coating strategy was applied to APT specimens of resin embedded Au nanospheres. Results demonstrate that the optimal coating strategy allows unique pulsed-voltage atom probe analysis and 3D imaging of biological and insulated samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Near-field photochemical and radiation-induced chemical fabrication of nanopatterns of a self-assembled silane monolayer

Directory of Open Access Journals (Sweden)

Ulrich C. Fischer

2014-09-01

Full Text Available A general concept for parallel near-field photochemical and radiation-induced chemical processes for the fabrication of nanopatterns of a self-assembled monolayer (SAM of (3-aminopropyltriethoxysilane (APTES is explored with three different processes: 1 a near-field photochemical process by photochemical bleaching of a monomolecular layer of dye molecules chemically bound to an APTES SAM, 2 a chemical process induced by oxygen plasma etching as well as 3 a combined near-field UV-photochemical and ozone-induced chemical process, which is applied directly to an APTES SAM. All approaches employ a sandwich configuration of the surface-supported SAM, and a lithographic mask in form of gold nanostructures fabricated through colloidal sphere lithography (CL, which is either exposed to visible light, oxygen plasma or an UV–ozone atmosphere. The gold mask has the function to inhibit the photochemical reactions by highly localized near-field interactions between metal mask and SAM and to inhibit the radiation-induced chemical reactions by casting a highly localized shadow. The removal of the gold mask reveals the SAM nanopattern.

Synthesis of strongly fluorescent carbon quantum dots modified with polyamidoamine and a triethoxysilane as quenchable fluorescent probes for mercury(II)

International Nuclear Information System (INIS)

Tang, Wenjie; Wang, Yan; Wang, Panpan; Di, Junwei; Wu, Ying; Yang, Jianping

2016-01-01

This article reports on the synthesis of water dispersible carbon quantum dots (CDs) by a one-step hydrothermal method using polyamidoamine (PAMAM) and (3-aminopropyl)triethoxysilane (APTES) as a platform and passivant. The resulting CDs are highly uniform and finely dispersed. The synergistic effect between PAMAM and APTES on the surface of the CDs results in a fluorescence that is much brighter than that of CDs modified with either APTES or PAMAM only. The fluorescence of the co-modified CDs is quenched by Hg(II) ions at fairly low concentrations. Under the optimum conditions, the intensity of quenched fluorescence drops with Hg(II) concentration in the range from 0.2 nM to 10 μM, and the detection limit is 87 fM. The effect of potentially interfering cations on the fluorescence revealed a high selectivity for Hg 2+ . The fluorescent probe was applied to the determination of Hg(II) in (spiked) waters and milk and gave recoveries between 95.6 and 107 %, with relative standard deviation between 4.4 and 6.0 %. (author)

Progress report on the accelerator production of tritium materials irradiation program

International Nuclear Information System (INIS)

Maloy, S.A.; Sommer, W.F.; Brown, R.D.; Roberts, J.E.

1997-01-01

The Accelerator Production of Tritium (APT) project is developing an accelerator and a spoliation neutron source capable of producing tritium through neutron capture on He-3. A high atomic weight target is used to produce neutrons that are then multiplied and moderated in a blanket prior to capture. Materials used in the target and blanket region of an APT facility will be subjected to several different and mixed particle radiation environments; high energy protons (1-2 GeV), protons in the 20 MeV range, high energy neutrons, and low energy neutrons, depending on position in the target and blanket. Flux levels exceed 10 14 /cm 2 s in some areas. The APT project is sponsoring an irradiation damage effects program that will generate the first data-base for materials exposed to high energy particles typical of spallation neutron sources. The program includes a number of candidate materials in small specimen and model component form and uses the Los Alamos Spallation Radiation Effects Facility (LASREF) at the 800 MeV, Los Alamos Neutron Science Center (LANSCE) accelerator

Functionalized vertically aligned ZnO nanorods for application in electrolyte-insulator-semiconductor based pH sensors and label-free immuno-sensors

International Nuclear Information System (INIS)

Kumar, Narendra; Senapati, Sujata; Kumar, Jitendra; Panda, Siddhartha; Kumar, Satyendra

2016-01-01

Vertically aligned ZnO nanorods were grown on a SiO 2 /Si surface by optimization of the temperature and atmosphere for annealing of the seed. The seed layer annealed at 500 °C in vacuum provided well separated and uniform seeds which also provided the best condition to get densely packed, uniformly distributed, and vertically aligned nanorods. These nanorods grown on the substrates were used to fabricate electrolyte-insulator-semiconductor (EIS) devices for pH sensing. Etching of ZnO at acidic pH prevents the direct use of nanorods for pH sensing. Therefore, the nanorods functionalised with 3-aminopropyltriethoxysilane (APTES) were utilized for pH sensing and showed the pH sensitivity of 50.1 mV/pH. APTES is also known to be used as a linker to immobilize biomolecules (such as antibodies). The EIS device with APTES functionalized nanorods was used for the label free detection of prostate-specific antigen (PSA). Finally, voltage shifts of 23 mV and 35 mV were observed with PSA concentrations of 1 ng/ml and 100 ng/ml, respectively. (paper)

Acid perfusion test in gastroesophageal reflux disease

Energy Technology Data Exchange (ETDEWEB)

Kaul, B.; Petersen, H.; Grette, K.; Myrvold, H.E.

1986-01-01

An acid perfusion test, isotope scanning, endoscopy, and esophageal biopsy were performed in 101 patients with symptoms strongly suggestive of gastroesophageal reflux (GER) disease. A positive acid perfusion test within 30 min (APT) and within 5 min (TAPT) was found in 70.2% and 37.6% of the patients, respectively. A positive APT was found significantly more often in patients with than without endoscopic esophagitis, whereas a positive TAPT was found significantly more often in patients with severe symptoms than in patients with moderate symptoms, and in a significantly higher proportion of patients with than without GER by scintigraphy. Neither the APT nor the TAPT showed any dependency on the presence of histologic esophagitis. Most (97%) patients with a negative acid perfusion test, in addition to typical symptoms, also presented with scintigraphic, endoscopic, or histologic evidence of GER disease. Although it shows that the acid perfusion test, particularly when early positive, may serve as a weak predictor of the severity of GER disease, the present study gives little support to the test's clinical usefulness.

Aptamer-conjugated PEGylated quantum dots targeting epidermal growth factor receptor variant III for fluorescence imaging of glioma

Directory of Open Access Journals (Sweden)

Tang J

2017-05-01

Full Text Available Jiaze Tang,1 Ning Huang,1 Xiang Zhang,1,2 Tao Zhou,3 Ying Tan,1,4 Jiangli Pi,5 Li Pi,1 Si Cheng,6 Huzhi Zheng,5 Yuan Cheng1 1Department of Neurosurgery, The Second Affiliated Hospital of Chongqing Medical University, 2Chongqing Key Laboratory of Ultrasound Molecular Imaging, Institute of Ultrasound Imaging, 3Chongqing Key Laboratory of Biochemistry and Molecular Pharmacology, 4Institute of Life Sciences, Chongqing Medical University, 5Key Laboratory on Luminescent and Real-Time Analytical Chemistry, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, 6Department of Orthopaedics, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China Abstract: The extent of resection is a significant prognostic factor in glioma patients. However, the maximum safe resection level is difficult to determine due to the inherent infiltrative character of tumors. Recently, fluorescence-guided surgery has emerged as a new technique that allows safe resection of glioma. In this study, we constructed a new kind of quantum dot (QD-labeled aptamer (QD-Apt nanoprobe by conjugating aptamer 32 (A32 to the QDs surface, which can specially bind to the tumors. A32 is a single-stranded DNA capable of binding to the epidermal growth factor receptor variant III (EGFRvIII specially distributed on the surface of glioma cells. To detect the expression of EGFRvIII in human brain tissues, 120 specimens, including 110 glioma tissues and 10 normal brain tissues, were examined by immunohistochemistry, and the results showed that the rate of positive expression of EGFRvIII in the glioma tissues was 41.82%, and 0.00% in normal brain tissues. Besides, the physiochemical properties of QD-Apt nanoparticles (NPs were thoroughly characterized. Biocompatibility of the NPs was evaluated, and the results suggested that the QD-Apt was nontoxic in vivo and vitro. Furthermore, the use of the QD-Apt in labeling

Non-enzymolytic adenosine barcode-mediated dual signal amplification strategy for ultrasensitive protein detection using LC-MS/MS.

Science.gov (United States)

Yang, Wen; Li, Tengfei; Shu, Chang; Ji, Shunli; Wang, Lei; Wang, Yan; Li, Duo; Mtalimanja, Michael; Sun, Luning; Ding, Li

2018-05-10

A method is described for the determination of proteins with LC-MS/MS enabled by a small molecule (adenosine) barcode and based on a double-recognition sandwich structure. The coagulation protein thrombin was chosen as the model analyte. Magnetic nanoparticles were functionalized with aptamer29 (MNP/apt29) and used to capture thrombin from the samples. MNP/apt29 forms a sandwich with functionalized gold nanoparticles modified with (a) aptamer15 acting as thrombin-recognizing element and (b) a large number of adenosine as mass barcodes. The sandwich formed (MNP/apt29-thrombin-apt15/AuNP/adenosine) can ben magnetically separated from the sample. Mass barcodes are subsequently released from the sandwiched structure for further analysis by adding 11-mercaptoundecanoic acid. Adenosine is then detected by LC-MS/MS as it reflects the level of thrombin with impressively amplified signal. Numerous adenosines introduced into the sandwich proportional to the target concentration further amplify the signal. Under optimized conditions, the response is linearly proportional to the thrombin concentration in the range of 0.02 nM to 10 nM, with a detection limit of 9 fM. The application of this method to the determination of thrombin in spiked plasma samples gave recoveries that ranged from 92.3% to 104.7%. Graphical abstract Schematic representation of a method for the determination of thrombin with LC-MS/MS. The method is based on a double-recognition sandwiched structure. With LC-MS/MS, mass barcodes (adenosine) are detected to quantify thrombin, which amplifies the detection signal impressively.

Carbon/Attapulgite Composites as Recycled Palm Oil-Decoloring and Dye Adsorbents

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Guangyan Tian

2018-01-01

Full Text Available Activated clay minerals have been widely used in the edible oil refining industry for decolorization of crude oil by adsorption, and so far many methods have been used to improve their decolorization efficiency. Herein, we successfully prepared a series of carbon/attapulgite (C/APT composite adsorbents by a one-step in-situ carbonization process with natural starch (St as the carbon source. It has been revealed that the adsorbent had better decolorization efficiency for crude palm oil than acid-activated APT. However, more than a million tons of decolorized waste is produced every year in the oil-refining industry, which was often treated as solid waste and has not yet been reutilized effectively. In order to explore a viable method to recycle and reuse the decolorant, the waste decolorant was further prepared into new C/APT adsorbents for the removal of dyes from wastewater, and then the dyes adsorbed on the adsorbent were used as the carbon sources to produce new C/APT adsorbents by a cyclic carbonization process. The results showed that the adsorbents prepared from the decolorized waste could remove more than 99.5% of the methylene blue (MB, methyl violet (MV, and malachite green (MG dyes from the simulated wastewater with the dye concentration of 200 mg/L, and the C/APT–Re adsorbent consecutively regenerated five times using the adsorbed dyes as a carbon source still exhibit good adsorption efficiency for dyes. As a whole, this process opens a new avenue to develop efficient decolorants of palm oil and achieves recyclable utilization of decolored waste.

Effect of compliance during periodontal maintenance therapy on levels of bacteria associated with periodontitis: A 6-year prospective study.

Science.gov (United States)

Costa, Fernando Oliveira; Vieira, Thaís Riberal; Cortelli, Sheila Cavalca; Cota, Luís Otávio Miranda; Costa, José Eustáquio; Aguiar, Maria Cássia Ferreira; Cortelli, José Roberto

2018-05-01

It is well established that regular compliance during periodontal maintenance therapy (PMT) maintains the stability of periodontal clinical parameters obtained after active periodontal therapy (APT). However, compliance during PMT has not yet been related to subgingival bacterial levels. Thus, this study followed individuals in PMT over 6 years and longitudinally evaluated the effects of compliance on periodontitis-associated bacterial levels and its relation to periodontal status. From a 6-year prospective cohort study with 212 individuals in PMT, 91 were determined to be eligible. From this total, 28 regular compliers (RC) were randomly selected and matched for age and sex with 28 irregular compliers (IC). Complete periodontal examination and microbiological samples were obtained 5 times: T1 (prior to APT), T2 (after APT), T3 (2 years), T4 (4 years), and T5 (6 years). Total bacteria counts and levels of Actinomyces naeslundii, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola were evaluated through quantitative polymerase chain reaction. RC had less tooth loss and better clinical and microbiological conditions over time when compared with IC. IC had higher total bacterial counts and higher levels of T. denticola. Moreover, among IC, total bacterial counts were positively associated with plaque index and bleeding on probing, while levels of A. naeslundii, T. forsythia, and T. denticola were negatively associated with clinical attachment loss (4 to 5 mm) among RC. Compliance positively influenced subgingival microbiota and contributed to stability of periodontal clinical status. Regular visits during PMT sustained microbiological benefits provided by APT over a 6-year period. © 2018 American Academy of Periodontology.

Aminopropyl-Silica Hybrid Particles as Supports for Humic Acids Immobilization

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Mónika Sándor

2016-01-01

Full Text Available A series of aminopropyl-functionalized silica nanoparticles were prepared through a basic two step sol-gel process in water. Prior to being aminopropyl-functionalized, silica particles with an average diameter of 549 nm were prepared from tetraethyl orthosilicate (TEOS, using a Stöber method. In a second step, aminopropyl-silica particles were prepared by silanization with 3-aminopropyltriethoxysilane (APTES, added drop by drop to the sol-gel mixture. The synthesized amino-functionalized silica particles are intended to be used as supports for immobilization of humic acids (HA, through electrostatic bonds. Furthermore, by inserting beside APTES, unhydrolysable mono-, di- or trifunctional alkylsilanes (methyltriethoxy silane (MeTES, trimethylethoxysilane (Me3ES, diethoxydimethylsilane (Me2DES and 1,2-bis(triethoxysilylethane (BETES onto silica particles surface, the spacing of the free amino groups was intended in order to facilitate their interaction with HA large molecules. Two sorts of HA were used for evaluating the immobilization capacity of the novel aminosilane supports. The results proved the efficient functionalization of silica nanoparticles with amino groups and showed that the immobilization of the two tested types of humic acid substances was well achieved for all the TEOS/APTES = 20/1 (molar ratio silica hybrids having or not having the amino functions spaced by alkyl groups. It was shown that the density of aminopropyl functions is low enough at this low APTES fraction and do not require a further spacing by alkyl groups. Moreover, all the hybrids having negative zeta potential values exhibited low interaction with HA molecules.

Attosecond pulse trains from long laser-gas interaction targets

International Nuclear Information System (INIS)

Hauri, C.P.; Lopez-Martens, R.; Varju, K.; Ruchon, T.; Gustafsson, E.; L'Huillier, A.

2006-01-01

Complete test of publication follows. Many experiments in attosecond physics require high XUV photon flux as well as a clean attosecond pulse train (APT) temporal structure. Temporal characterization of high-order harmonic generation (HHG) in long interaction targets is thus of high interest. HHG being a very inefficient process, a large effort has been made to increase the amount of XUV photons emitted per infrared laser pulse. Besides quasi phase-matching in a modulated capillary, loose driving laser focusing conditions and subsequent self-channeling have shown to significantly increase the conversion efficiency. We characterized the temporal structure of APTs generated during the self-channeling of an intense IR driving laser pulse. Our first results indicate, however, that the temporal structure of the APT generated during the HHG process might be affected by quantum path interference and spectral phase distortion due to the self-channeling process itself. In particular, our measurements show that the relative spectral phase between consecutive harmonics can strongly vary depending on the target length and the position of the laser focus with respect to the target. In general for short gas targets, no clean APT structure can be expected since the individual attosecond pulses carry significant chirp. For longer targets, however, we observe a flattening of the harmonic spectral phase, resulting in near-transform-limited attosecond pulse trains. A complete analysis of the process is complex and involves detailed knowledge of the spatial and temporal evolution of the self-channeling driver laser pulse throughout the gas target.

Accelerated pavement testing of thin RCC over soil cement pavements

Directory of Open Access Journals (Sweden)

Zhong Wu

2016-05-01

Full Text Available Three full-scale roller compacted concrete (RCC pavement sections built over a soil cement base were tested under accelerated pavement testing (APT. The RCC thicknesses varied from 102 mm (4 in. to 152 mm (6 in. and to 203 mm (8 in., respectively. A bi-directional loading device with a dual-tire load assembly was used for this experiment. Each test section was instrumented with multiple pressure cells and strain gages. The objective was to evaluate the structural performance and load carrying capacity of thin RCC-surfaced pavements under accelerated loading. The APT results generally indicated that all three RCC pavement sections tested in this study possessed very high load carrying capacity; an estimated pavement life in terms of equivalent single axle load (ESAL for the thinnest RCC section (i.e., RCC thickness of 102 mm evaluated was approximately 19.2 million. It was observed that a fatigue failure would be the primary pavement distress type for a thin RCC pavement under trafficking. Specifically, the development of fatigue cracking was found to originate from a longitudinal crack at the edge or in the center of a tire print, then extended and propagated, and eventually merged with cracks of other directions. Instrumentation results were used to characterize the fatigue damage under different load magnitudes. Finally, based on the APT performance of this experiment, two fatigue models for predicting the fatigue life of thin RCC pavements were developed. Keywords: Roller compacted concrete, APT, Pavement performance, Non-destructive testing, Fatigue analysis

A quantum dot-aptamer beacon using a DNA intercalating dye as the FRET reporter: application to label-free thrombin detection.

Science.gov (United States)

Chi, Chun-Wei; Lao, Yeh-Hsing; Li, Yi-Shan; Chen, Lin-Chi

2011-03-15

A new quantum dot (QD)-aptamer (apt) beacon that acts by folding-induced dissociation of a DNA intercalating dye, BOBO-3(B), is demonstrated with label-free thrombin detection. The beacon, denoted as QD-apt:B, is constructed by (1) coupling of a single-stranded thrombin aptamer to Qdot 565 via EDC/Sulfo-NHS chemistry and (2) staining the duplex regions of the aptamer on QD with excess BOBO-3 before thrombin binding. When mixing a thrombin sample with QD-apt:B, BOBO-3 is competed away from the beacon due to target-induced aptamer folding, which then causes a decrease in QD fluorescence resonance energy transfer (FRET)-mediated BOBO-3 emission and achieves thrombin quantitation. In this work, the effects of Mg(2+), coupling time, and aptamer type on the beacon's performances are investigated and discussed thoroughly with various methods, including transmission electron microscopy (TEM), dynamic light scattering (DLS), and two-color differential gel electrophoresis. Using the best aptamer beacon (HTQ37), we attain highly specific and wide-range detection (from nM to μM) of thrombin in buffer, and the beacon can sense nM-range thrombin in 15% diluted serum. Compared to the reported QD aptamer assays, our method is advantageous from the aspect of using a simple sensory unit design without losing the detection sensitivity. Therefore, we consider the QD-apt:B beacon a potential alternative to immuno-reagents and an effective tool to study nucleic acid folding on QD as well. Copyright © 2011 Elsevier B.V. All rights reserved.

Impact of dynamic specimen shape evolution on the atom probe tomography results of doped epitaxial oxide multilayers: Comparison of experiment and simulation

Energy Technology Data Exchange (ETDEWEB)

Madaan, Nitesh; Nandasiri, Manjula; Devaraj, Arun, E-mail: arun.devaraj@pnnl.gov [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 3335 Innovation Boulevard, Richland, Washington 99354 (United States); Bao, Jie [Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99354 (United States); Xu, Zhijie [Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99354 (United States); Thevuthasan, Suntharampillai [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 3335 Innovation Boulevard, Richland, Washington 99354 (United States); Qatar Environment and Energy Research Institute, Qatar Foundation, PO Box 5825, Doha (Qatar)

2015-08-31

The experimental atom probe tomography (APT) results from two different specimen orientations (top-down and sideways) of a high oxygen ion conducting Samaria-doped-ceria/Scandia-stabilized-zirconia multilayer thin film solid oxide fuel cell electrolyte was compared with level-set method based field evaporation simulations for the same specimen orientations. This experiment-simulation comparison explains the dynamic specimen shape evolution and ion trajectory aberrations that can induce density artifacts in final reconstruction, leading to inaccurate estimation of interfacial intermixing. This study highlights the importance of comparing experimental results with field evaporation simulations when using APT to study oxide heterostructure interfaces.

Caracteristicas de crescimento de uma linhagem selvagem de Streptococcus thermophilus, sua adesão em superficie de aço inoxidavel e comportamento frente a detergencia e sanificação

OpenAIRE

Ana Lourdes Neves Gandara

1995-01-01

Resumo: Microrganismo selvagem isolado de leite pasteurizado, obtido de processo contínuo de pasteurização HTST com 4 h de operação foi identificado como Streptococcus thermophilus, formando a maior densidade celular em caldo M11 a 45°C em 6h. O número de células viáveis desse microrganismo foi avaliado em meios de cultura PCA, APT, MRS e Ml1 sendo os meios M11 e MRS os que permitiram melhor crescimento. Menores contagens do microrganismo foram observadas no meio APT em relação aos meios ante...

Statsansattes ansættelsesforhold før og efter omdannelsen af en statsvirksomhed til statsejet aktieselskab

DEFF Research Database (Denmark)

Postelmans, Erik

2009-01-01

will be apt to rule against the civil servant. Another law that protects civil servants and other state employees against among other things, dismissals, is the Danish Public Administration Act. No ‘decision’ concerning an individual can be made without them having had the possibility to be heard...... of the responsibility labour Unions have in advising their members should not be underestimated. This is verified by the fact that courts are not apt to dismiss agreements that have been negotiated with the labour unions. From these cases it must be assumed that the unions act in a professional, impartial manner when...

Low-temperature poly(oxymethylene) direct bonding via self-assembled monolayer

Science.gov (United States)

Fu, Weixin; Ma, Bo; Kuwae, Hiroyuki; Shoji, Shuichi; Mizuno, Jun

2018-02-01

A direct bonding of poly(oxymethylene) (POM) was feasible at 100 °C by using self-assembled monolayer (SAM) as a surface modification method. (3-aminopropyl)triethoxysilane (APTES) and (3-glycidyloxypropyl)trimethoxysilane (GOPTS) were used in our work. X-ray photoelectron spectroscopy showed that both APTES and GOPTS modified the POM surface successfully. Bonding strength evaluation revealed that surface modification was affected by pretreatment (VUV/O3) process time. In addition, the bonding condition with highest strength had an average strength of 372 kPa. This technology is expected to be used in packaging for micro-/nano-electromechanical systems, such as biomedical devices.

Cooked meat products made of coarsely ground pork: the main bacterial strains of bacterial flora, their heat resistance and effect on spoilage

Directory of Open Access Journals (Sweden)

Esko Petäjä

1993-09-01

Full Text Available This study was conducted to investigate the bacterial flora of the surface layer and the core of meat products made of coarsely ground pork at the moment of spoilage when stored at 7°C or 4°C. The dominating strains were isolated, their heat resistance was studied in APT-broth, on APT-agar and in coarsely ground cured pork, and their growth after heating and effect on spoilage were followed in coarsely ground cured pork. The first signs of spoilage appeared in the surface layer of the products. The strains were coccoid lactic acid bacteria with counts ranging from 3,5 to 7.8 log cfu (colony forming units/g. They survived only accidentally after heating for 15 minutes at 72°C in APT-broth. The core of the products contained only coccoid lactic acid bacteria or only pseudomonads or both as the main bacterial strains. The counts ranged from 2.6 to 6.0 log cfu/g. Most of the strains isolated from the core survived after heating for 30 minutes at 72°C in APT-broth in at least three tests out of six. The most noticeable result of the study was the occurence of heat-resistant pseudomonads in the core. It must be pointed out that all pseudomonads found survived after heating for 60 minutes at 72°C in APT-broth, and often after heating for 15 minutes at 72°C in coarsely ground cured pork (core 72°C. The cfu number of the two most heat-resistant streptococcus strains decreased only 1 log unit over 15 minutes at 72°C in coarsely ground cured pork. The numbers of inoculated pseudomonads decreased but those of streptococci rose by a maximum of 1 log unit when the experimental porks were kept at 4°C after heating. This indicates that streptococci and pseudomonads probably do not constitute a serious spoilage factor in cooked meat products, but spoilage is generally effected by bacteria which have contaminated the surface layer of the products after heat treatment.

Risk of Porphyromonas gingivalis recolonization during the early period of periodontal maintenance in initially severe periodontitis sites.

Science.gov (United States)

Fujise, Osamu; Miura, Mayumi; Hamachi, Takafumi; Maeda, Katsumasa

2006-08-01

Porphyromonas gingivalis is considered a critical pathogen of periodontal diseases including recurrent periodontitis. The profound effects of active periodontal treatment (APT) on P. gingivalis elimination were previously demonstrated and revealed that the subsequent P. gingivalis-free or -suppressed status seems to be maintained during early periodontal maintenance (PMT). The aim of the present study was to show the occurrence of microbial recolonization during this early PMT period. In total, 128 sites from 11 generalized chronic periodontitis patients and one generalized aggressive periodontitis patient underwent clinical and microbiologic examination at baseline (Exam-I), after APT (Exam-II), and in PMT (Exam-III). Exam-III was carried out an average of 4.5 +/- 3.5 months after Exam-II. Detection and quantification of putative pathogens were performed using a polymerase chain reaction-based method. The PMT used was effective in maintaining the clinical conditions improved by APT. However, in microbiological examinations, Exam-III showed higher detection frequency and levels of P. gingivalis than Exam-II. This suggests that a P. gingivalis recolonization started in the early PMT period. P. gingivalis-increased sites then showed significantly more severe signs of periodontitis in Exam-I than P. gingivalis-stable sites (bleeding on probing frequency: 76.7% versus 56.5%; suppuration frequency: 41.9% versus 12.9%). On the other hand, in Exam-II, no significant differences of clinical parameters were noted between P. gingivalis-increased and -stable sites. Severe periodontitis sites before APT seemed to place them at risk of P. gingivalis recolonization in the early PMT period, and this microbial restoration could be a cause of recurrent periodontitis.

Developing an environmental compliance program for accelerator production of tritium

International Nuclear Information System (INIS)

Reynolds, R.W.; Roberts, J.S.; Dyer, K.W.; Shedrow, C.B.; Sheetz, S.O.; England, J.L.

1998-01-01

This paper addresses the development of an environmental program for a large proposed federal project currently in the preliminary design phase, namely, the accelerator production of tritium (APT) for the US Department of Energy (DOE). This project is complicated not only by its size ($3.5 to $4.5 billion) but also by its technical complexity and one-of-a-kind nature. This is further complicated by the fact that government projects are driven by budgets subject to public pressures and annual Congressional fiscal considerations, whereas private companies are driven by profits. The measure of success for a federal project such as the APT is based on level of public support, not profits. Finally, there are not too many equivalent environmental programs that could be used as models, and benchmarking is nearly impossible. Forming an environmental program during the conceptual design phase of this large federal project included the formation of a core environmental working group (EWG). The group has membership from all major project organizations with a charter formally recognized by the project director. The envelope for traditional environmental work for the APT project has been stretched to include teaming with management in the establishment of project goals and direction. The APT EWG was set up organizationally to include several subgroups or teams that do the real work of assessing, establishing the regulatory framework, and then developing a compliance program. Setting aside the organizational difficulties of selecting the right team leads and members, each team was tasked with developing a charter, plan, and schedule. Since then, each team has developed an appropriate level of supporting documentation to address its particular issues and requirements

Transistorized pulse amplifiers (A.I.T.); Amplificateurs d'impulsions a transistors (A.I.T.)

Energy Technology Data Exchange (ETDEWEB)

Feyt, J; Couly, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-07-01

The two amplifiers whose design and operation are described in this report have been studied for neutron detection units used in piles. They are designed to allow an important reduction of the volume and of the weight of the detector and its amplifier, and to simplify the operation of the detection assembly. To these characteristics can be added the mechanical and electrical robustness and the very reduced micro-phony. The first transistorized amplifier (AIT.1) is simple, very robust, and can be used for radioprotection installations. The second (AIT.4) has a better performance and makes it possible to replace the APT.2 in most of its applications (it has even been used satisfactorily in an apparatus where the micro-phony and the sensitivity to interference of the APT.2 made this latter unusable). (author) [French] Les deux amplificateurs dont ce rapport decrit la conception et le fonctionnement ont ete etudies pour les ensembles de detection des neutrons aupres des piles. Ils ont ete concus pour permettre une reduction importante du volume et du poids du detecteur et de son amplificateur, et pour simplifier le fonctionnement de l'ensemble de detection. A ces caracteristiques s'ajoutent une grande robustesse mecanique et electrique et une microphonie quasi nulle. Le premier amplificateur a transistors (AIT.1) simple, tres robuste, convient pour les installations de radioprotection. Le deuxieme (AIT.4) de performances plus elevees permet de remplacer l'APT.2 dans la plupart de ses applications (il a meme ete utilise avec satisfaction dans un montage ou la microphonie et la sensibilite aux parasites de l'APT.2 rendaient celui-ci inutilisable). (auteur)

Robust aptamer–polydopamine-functionalized M-PLGA–TPGS nanoparticles for targeted delivery of docetaxel and enhanced cervical cancer therapy

Directory of Open Access Journals (Sweden)

Xu GJ

2016-06-01

Full Text Available Guojun Xu,1–3,* Xinghua Yu,2,* Jinxie Zhang,1,2,* Yingchao Sheng,4 Gan Liu,2 Wei Tao,1,2 Lin Mei1,2 1School of Life Sciences, Tsinghua University, Beijing, 2Graduate School at Shenzhen, Tsinghua University, Shenzhen, 3School of Materials Science and Engineering, Tsinghua University, Beijing, 4Department of Orthopedic Surgery, Changshu Hospital of TCM, Changshu, People’s Republic of China *These authors contributed equally to this work Abstract: One limitation of current biodegradable polymeric nanoparticles (NPs is the contradiction between functional modification and maintaining formerly excellent bioproperties with simple procedures. Here, we reported a robust aptamer–polydopamine-functionalized mannitol-functionalized poly(lactide-co-glycolide (M-PLGA–D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS nanoformulation (Apt-pD-NPs for the delivery of docetaxel (DTX with enhanced cervical cancer therapy effects. The novel DTX-loaded Apt-pD-NPs possess satisfactory advantages: 1 increased drug loading content and encapsulation efficiency induced by star-shaped copolymer M-PLGA–TPGS; 2 significant active targeting effect caused by conjugated AS1411 aptamers; and 3 excellent long-term compatibility by incorporation of TPGS. Therefore, with simple preparation procedures and excellent bioproperties, the new functionalized Apt-pD-NPs could maximally increase the local effective drug concentration on tumor sites, achieving enhanced treatment effectiveness and minimizing side effects. In a word, the robust DTX-loaded Apt-pD-NPs could be used as potential nanotherapeutics for cervical cancer treatment, and the aptamer–polydopamine modification strategy could be a promising method for active targeting of cancer therapy with simple procedures. Keywords: dopamine, AS1411 aptamer, active targeting, polymeric NPs, enhanced cervical chemotherapy

Technological Competitiveness of Ukraine under Conditions of a New Industrial Revolution and Development of Convergent Technologies

Directory of Open Access Journals (Sweden)

Matyushenko Igor Yu.

2016-02-01

Full Text Available The article considers the problem of increasing the technological competitiveness of Ukrainian enterprises under conditions of a new industrial revolution through the development and introduction of advanced converged technologies. The classification of industrial revolutions, namely, industrial, technological, information and Industry 4.0, is presented, and it has been determined that the key factor of the latter is cyber physical systems for introduction of the client-oriented “Internet of Things”. It has been justified that the formation of Industry 4.0 in developed countries will occur through advanced production technologies (APT, which main characteristics are technological substitution, automation, customization, localization and economic efficiency. It has been found that in 2020 the main priority APT will be: systems of production process control; multidimensional modeling of complex products; intelligent production systems and robotics; systems of creation and transformation (growing of material objects and 3D-printing; materials effective in creating perspective actuating devices (compositional and those that exhibit their properties in small-size structures. It has been proved that the recovery of Ukraine’s industry is not possible on the old industrial base, and the creation of a new industry based on APT of Industry 4.0 is possible in the following areas: ICT (primarily in the field of software development; new composite materials with specified properties; industrial nanobiotechnologies (biomedicine and pharmacy, new agricultural technologies; mathematical modeling for creation of intelligent production systems; space research and development (in particular, development of the first stages of heavy missiles. The necessity of elaborating state programs of competitiveness development on the basis of APT, foresight research oftechnology priorities, promoting high-tech exports in Ukraine has been substantiated.

A novel reduced graphene oxide/molybdenum disulfide/polyaniline nanocomposite-based electrochemical aptasensor for detection of aflatoxin B1.

Science.gov (United States)

Geleta, Girma Selale; Zhao, Zhen; Wang, Zhenxin

2018-03-26

In this study, we developed a novel reduced graphene oxide/molybdenum disulfide/polyaniline@gold nanoparticles-based electrochemical aptasensor (termed as RGO/MoS2/PANI@AuNPs/Apt) for detection of aflatoxin B1 (AFB1). The RGO/MoS2/PANI nanocomposites were synthesized and characterized by multiple techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), infrared spectroscopy (FTIR), UV-visible spectroscopy, and X-ray photoelectron spectroscopy (XPS). A glassy carbon electrode (GCE) was then modified by the RGO/MoS2/PANI nanocomposites, coated with a chitosan (Cs) film, and followed by AuNPs attachment for immobilizing the AFB1 aptamers. In the presence of AFB1, the AFB1 binding-induced conformation change of the immobilized aptamer on the electrode surface results in the reduction of the electron transfer from a [Fe(CN)6]3-/4- redox couple in the solution to the GCE surface. Therefore, the aptamer-AFB1 binding event can be easily monitored by the peak current change of the RGO/MoS2/PANI@AuNPs/Apt through differential pulse voltammetry (DPV) measurement. Under the optimized conditions, the as-developed RGO/MoS2/PANI@AuNPs/Apt exhibits a wide linear range from 0.01 fg mL-1 to 1.0 fg mL-1 and a remarkably low detection limit (3σ) of 0.002 fg mL-1. The aptasensor also has good reproducibility as well as shows high selectivity against other fungal toxins, such as OTA and FB1. Moreover, the practicability of the RGO/MoS2/PANI@AuNPs/Apt was demonstrated by the analysis of AFB1 in the spiked wine samples.

Protein patterning on polycrystalline silicon-germanium via standard UV lithography for bioMEMS applications

Energy Technology Data Exchange (ETDEWEB)

Lenci, S., E-mail: silvia.lenci@gmail.com [Dipartimento di Ingegneria dell' Informazione, University of Pisa, Via G. Caruso 16, I-56122 Pisa (Italy); imec, Kapeldreef 75, Leuven B-3001 (Belgium); Tedeschi, L.; Domenici, C.; Lande, C. [Istituto di Fisiologia Clinica, CNR, via G. Moruzzi 1, Pisa I-56124 (Italy); Nannini, A.; Pennelli, G.; Pieri, F. [Dipartimento di Ingegneria dell' Informazione, University of Pisa, Via G. Caruso 16, I-56122 Pisa (Italy); Severi, S. [imec, Kapeldreef 75, Leuven B-3001 (Belgium)

2010-10-12

Polycrystalline silicon-germanium (poly-SiGe) is a promising structural material for the post-processing of micro electro-mechanical systems (MEMS) on top of complementary metal-oxide-semiconductor (CMOS) substrates. Combining MEMS and CMOS allows for the development of high-performance devices. We present for the first time selective protein immobilization on top of poly-SiGe surfaces, an enabling technique for the development of novel poly-SiGe based MEMS biosensors. Active regions made of 3-aminopropyl-triethoxysilane (APTES) were defined using silane deposition onto photoresist patterns followed by lift-off in organic solvents. Subsequently, proteins were covalently bound on the created APTES patterns. Fluorescein-labeled human serum albumin (HSA) was used to verify the immobilization procedure while the binding capability of the protein layer was tested by an antigen-labeled antibody pair. Inspection by fluorescence microscopy showed protein immobilization inside the desired bioactive areas and low non-specific adsorption outside the APTES pattern. Furthermore, the quality of the silane patches was investigated by treatment with 30 nm-diameter gold nanoparticles and scanning electron microscope observation. The developed technique is therefore a promising first step towards the realization of poly-SiGe based biosensors.

Comparative and complementary characterization of precipitate microstructures in Al-Mg-Si(-Li) alloys by transmission electron microscopy, energy dispersive X-ray spectroscopy and atom probe tomography

Energy Technology Data Exchange (ETDEWEB)

Koshino, Yuki [Department of Mechanical Engineering and Materials Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501 (Japan); Kozuka, Masaya [Materials Research Laboratory, Kobe Steel, Ltd., 1-5-5 Takatsukadai, Nishi-ku, Kobe 651-2271 (Japan); Hirosawa, Shoichi, E-mail: hirosawa@ynu.ac.jp [Department of Mechanical Engineering and Materials Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501 (Japan); Aruga, Yasuhiro [Materials Research Laboratory, Kobe Steel, Ltd., 1-5-5 Takatsukadai, Nishi-ku, Kobe 651-2271 (Japan)

2015-02-15

Highlights: • Microalloying addition of Li enhances the age-hardening response of Al-Mg-Si alloys. • Size and number density of nanoclusters or precipitates are increased by Li addition. • Mg and Si contents within the aggregates are inversely decreased by Li addition. • Microalloying Li accelerates heterogeneous nucleation of such Mg-Si aggregates. - Abstract: In this study, comparative and complementary characterization of precipitate microstructures by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and atom probe tomography (APT) has been performed for Al-0.55 wt%Mg-0.89 wt%Si(-0.043 wt%Li) alloys aged at 433 K for 1.2 ks (under aging) and 36 ks (peak aging). Quantitative estimation of nanometer-scale clusters (nanoclusters) and β″ precipitates by TEM and APT revealed that microalloying addition of Li increases the size and number density of these Mg-Si aggregates, resulting in the enhanced age-hardening response. Positive evidence by APT for the segregation of Li suggests that heterogeneous nucleation of such Mg-Si aggregates with the aid of Li is attributed to the modified precipitate microstructures and thus improved mechanical strength of this alloy system.

Effective NH2-grafting on attapulgite surfaces for adsorption of reactive dyes

International Nuclear Information System (INIS)

Xue, Ailian; Zhou, Shouyong; Zhao, Yijiang; Lu, Xiaoping; Han, Pingfang

2011-01-01

Highlights: → We prepared a new amine functionalized adsorbent derived from clay-based material. → Attapulgite surface was modified with 3-aminopropyltriethoxysilane. → Some modification parameters affecting the adsorption potential were investigated. → Enhance the attapulgite adsorptive capacity for reactive dyes from aqueous solutions. - Abstract: The amine moiety has an important function in many applications, including, adsorption, catalysis, electrochemistry, chromatography, and nanocomposite materials. We developed an effective adsorbent for aqueous reactive dye removal by modifying attapulgite with an amino-terminated organosilicon (3-aminopropyltriethoxysilane, APTES). Surface properties of the APTES-modified attapulgite were characterized by the Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption-desorption. We evaluated the impact of solvent, APTES concentration, water volume, reaction time, and temperature on the surface modification. NH 2 -attapulgite was used to remove reactive dyes in aqueous solution and showed very high adsorption rates of 99.32%, 99.67%, and 96.42% for Reactive Red 3BS, Reactive Blue KE-R and Reactive Black GR, respectively. These powerful dye removal effects were attributed to strong electrostatic interactions between reactive dyes and the grafted NH 2 groups.

Application of Delaunay tessellation for the characterization of solute-rich clusters in atom probe tomography

International Nuclear Information System (INIS)

Lefebvre, W.; Philippe, T.; Vurpillot, F.

2011-01-01

This work presents an original method for cluster selection in Atom Probe Tomography designed to be applied to large datasets. It is based on the calculation of the Delaunay tessellation generated by the distribution of atoms of a selected element. It requires a single input parameter from the user. Furthermore, no prior knowledge of the material is needed. The sensitivity of the proposed Delaunay cluster selection is demonstrated by its application on simulated APT datasets. A strong advantage of the proposed methodology is that it is reinforced by the availability of an analytical model for the distribution of Delaunay cells circumspheres, which is used to control the accuracy of the cluster selection procedure. Another advantage of the Delaunay cluster selection is the direct calculation of a sharp envelope for each identified cluster or precipitate, which leads to the more appropriate morphology of the objects as they are reconstructed in the APT dataset. -- Research Highligthts: →Original method for cluster selection in Atom Probe Tomography. →Delaunay tessellation generated by the distribution of solute atoms. →Direct calculation of a sharp envelope for each identified cluster or precipitate. →Delaunay cluster selection demonstrated by its application on simulated APT datasets.

Polydopamine-Functionalized CA-(PCL-ran-PLA) Nanoparticles for Target Delivery of Docetaxel and Chemo-photothermal Therapy of Breast Cancer

Science.gov (United States)

Kong, Na; Deng, Mei; Sun, Xiu-Na; Chen, Yi-Ding; Sui, Xin-Bing

2018-01-01

Current limitations of cancer therapy include the lack of effective strategy for target delivery of chemotherapeutic drugs, and the difficulty of achieving significant efficacy by single treatment. Herein, we reported a synergistic chemo-photothermal strategy based on aptamer (Apt)-polydopamine (pD) functionalized CA-(PCL-ran-PLA) nanoparticles (NPs) for effective delivery of docetaxel (DTX) and enhanced therapeutic effect. The developed DTX-loaded Apt-pD-CA-(PCL-ran-PLA) NPs achieved promising advantages, such as (i) improved drug loading content (LC) and encapsulation efficiency (EE) initiated by star-shaped copolymer CA-(PCL-ran-PLA); (ii) effective target delivery of drugs to tumor sites by incorporating AS1411 aptamers; (iii) significant therapeutic efficacy caused by synergistic chemo-photothermal treatment. In addition, the pD coating strategy with simple procedures could address the contradiction between targeting modification and maintaining formerly excellent bio-properties. Therefore, with excellent bio-properties and simple preparation procedures, the DTX-loaded Apt-pD-CA-(PCL-ran-PLA) NPs effectively increased the local drug concentration in tumor sites, minimized side effects, and significantly eliminated tumors, indicating the promising application of these NPs for cancer therapy. PMID:29527167

STS-37 crewmembers test CETA hand cart during training session in JSC's WETF

Science.gov (United States)

1989-01-01

STS-37 Atlantis, Orbiter Vehicle (OV) 104, Mission Specialist (MS) Jerry L. Ross and MS Jerome Apt test crew and equipment translation aid (CETA) manual hand over hand cart during underwater session in JSC's Weightless Environment Training Facility (WETF) Bldg 29. Wearing an extravehicular mobility unit (EMU), Ross pulls the CETA manual cart along the rail while Apt holds onto the back of the cart. The test will determine how difficult it is to maneuver cargo in such a manner when it is done in space on STS-37. The goal is to find the best method for astronauts to move around the exterior of Space Station Freedom (SSF).

The diagnosis of food allergy

DEFF Research Database (Denmark)

Soares-Weiser, K; Takwoingi, Y; Panesar, S S

2014-01-01

BACKGROUND: We investigated the accuracy of tests used to diagnose food allergy. METHODS: Skin prick tests (SPT), specific-IgE (sIgE), component-resolved diagnosis and the atopy patch test (APT) were compared with the reference standard of double-blind placebo-controlled food challenge. Seven......, the pooled sensitivities were 53% (95% CI 33-72), 88% (95 % CI 76-94), and 87% (95% CI 75-94), and specificities were 88% (95% CI 76-95), 68% (95% CI 56-77), and 48% (95% CI 36-59) for APT, SPT, and sIgE, respectively. For egg, pooled sensitivities were 92% (95% CI 80-97) and 93% (95% CI 82...

Hydrogen peroxide biosensor based on titanium oxide

Science.gov (United States)

Halim, Nur Hamidah Abdul; Heng, Lee Yook; Hashim, Uda

2015-09-01

In this work, a biosensor utilizing modified titania, TiO2 particles using aminopropyl-triethoxy-silane, (APTS) for developing hydrogen peroxide biosensor is presented. The surface of Ti-APTS particles is used as a support for hemoglobin immobilization via covalent bonding. The performance of the biosensor is determined by differential pulse voltammetry. The linear response was observed at the reduction current of redox mediator probe [FeCN6]3-/4- at potential between 0.22 V to 0.24 V. The preliminary result for electrochemistry study on this modified electrode is reported. The preliminary linear range is obtained from 1×10-2 M to 1×10-8 M.

Preparation of crosslinked polysiloxane/SiO{sub 2} nanocomposite via in-situ condensation and its surface modification on cotton fabrics

Energy Technology Data Exchange (ETDEWEB)

Hao, Lifen, E-mail: haolifen@sust.edu.cn [College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi' an, Shaanxi 710021 (China); Zibo Dahuanjiu Polygrace Tannery Group Co. Ltd., Zibo, Shandong 256400 (China); Gao, Tingting [College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi' an, Shaanxi 710021 (China); Xu, Wei [College of Resource and Environment, Shaanxi University of Science and Technology, Xi' an, Shaanxi 710021 (China); Zibo Dahuanjiu Polygrace Tannery Group Co. Ltd., Zibo, Shandong 256400 (China); Wang, Xuechuan [College of Resource and Environment, Shaanxi University of Science and Technology, Xi' an, Shaanxi 710021 (China); Yang, Shuqin; Liu, Xiangguo [Zibo Dahuanjiu Polygrace Tannery Group Co. Ltd., Zibo, Shandong 256400 (China)

2016-05-15

Highlights: • We used a two-step method to fabricate novel crosslinked polysiloxane/SiO{sub 2} nanocomposite (CLPS-SiO{sub 2}). • Superhydrophobic surface on cotton fiber can be conveniently constructed by CLPS-SiO{sub 2}. • Color and softness of the CLPS-SiO{sub 2} treated fabric would not be influenced at all. • The CLPS-SiO{sub 2} treated fabric possessed good washing durability. - Abstract: Novel crosslinked polysiloxane/SiO{sub 2} nanocomposite (CLPS-SiO{sub 2}) was successfully prepared via the in-situ condensation reaction of silica sols and crosslinked polysiloxane with end-capped triethoxysilane in solvent, which was firstly fabricated through the modification of our previously developed crosslinked polysiloxane with end-capped epoxy groups using aminopropyltriethoxysilane (APTES) and noted as APTES-CLPS. Chemical structures and thermal properties of the as-prepared resultants were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectra ({sup 1}H/{sup 13}C NMR) and thermogravimetric analysis (TGA). CLPS-SiO{sub 2} was applied as surface modification agent to treat cotton fabrics. Film morphologies and surface properties were examined with scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), contact angle measurements, and other instruments. FTIR and NMR confirmed structure of the products. CLPS-SiO{sub 2} showed better thermal stability than APTES-CLPS due to anchor of the nanosilica. APTES-CLPS could deposit a smooth film on cotton fiber surface. Besides, CLPS-SiO{sub 2} also coated the fibers with many nano-scaled tubercles beneath this smooth film by SEM. However, the APTES-CLPS film and the CLPS-SiO{sub 2} film on silicon-wafer were never homogeneous and had a few low or high peaks. The root mean square roughness (Rq) of APTES-CLPS film reached to 0.441 nm in 2 × 2 μm{sup 2} scanning field and at 5 nm data scale. Owing to the incorporation of

Calorimetric measurement of afterheat in target materials for the accelerator production of tritium

International Nuclear Information System (INIS)

Perry, R.B.

1994-01-01

The estimate of afterheat in a spallation target of lead (Pb) or tungsten (W), by calorimetry, is the purpose of this experiment in support of the Accelerator Production of Tritium (APT). Such measurements are needed to confirm code calculations, these being the only practical way of gaining this type of information in a form suitable to aid the design of the APT machine. Knowledge of the magnitude and duration of afterheat resulting from decay of activation products produced by proton bombardment of the target is necessary to quantify APT safety assumptions, to design target cooling and safety systems, and to reduce technical risk. Direct calorimetric measurement of the afterheat for the appropriate incident proton energies is more reliable than the available alternative, which is indirect, based on data from gamma-ray spectroscopy measurements. The basic concept, a direct measurement of decay afterheat which bypasses the laborious classical way of determining this quantity, has been demonstrated to work. The gamma-ray energy given off by the decay products produced in the activation of lead or tungsten with high-energy protons apparently does represent a significant fraction of the total decay energy. A calorimeter designed for measurement of isotopes decaying by alpha emission must be modified to reduce energy lost with escaping gamma rays. Replacement of the aluminum liner with a tungsten liner in the SSC measurement chamber resulted in a 270% increase in measured heat, proving that the energy loss in the earlier (1992) measurements was significant. Gamma-ray measurements are needed to confirm the gamma-ray absorption calculations for the calorimeter to determine the correction for loss of heat due to transmission of high-energy gamma rays through the calorimeter walls. The experiments at BLIP have shown that calorimetry can be a useful tool in measuring the afterheat in APT target materials

Developing and testing accelerated partner therapy for partner notification for people with genital Chlamydia trachomatis diagnosed in primary care: a pilot randomised controlled trial.

Science.gov (United States)

Estcourt, Claudia S; Sutcliffe, Lorna J; Copas, Andrew; Mercer, Catherine H; Roberts, Tracy E; Jackson, Louise J; Symonds, Merle; Tickle, Laura; Muniina, Pamela; Rait, Greta; Johnson, Anne M; Aderogba, Kazeem; Creighton, Sarah; Cassell, Jackie A

2015-12-01

Accelerated partner therapy (APT) is a promising partner notification (PN) intervention in specialist sexual health clinic attenders. To address its applicability in primary care, we undertook a pilot randomised controlled trial (RCT) of two APT models in community settings. Three-arm pilot RCT of two adjunct APT interventions: APTHotline (telephone assessment of partner(s) plus standard PN) and APTPharmacy (community pharmacist assessment of partner(s) plus routine PN), versus standard PN alone (patient referral). Index patients were women diagnosed with genital chlamydia in 12 general practices and three community contraception and sexual health (CASH) services in London and south coast of England, randomised between 1 September 2011 and 31 July 2013. 199 women described 339 male partners, of whom 313 were reported by the index as contactable. The proportions of contactable partners considered treated within 6 weeks of index diagnosis were APTHotline 39/111 (35%), APTPharmacy 46/100 (46%), standard patient referral 46/102 (45%). Among treated partners, 8/39 (21%) in APTHotline arm were treated via hotline and 14/46 (30%) in APTPharmacy arm were treated via pharmacy. The two novel primary care APT models were acceptable, feasible, compliant with regulations and capable of achieving acceptable outcomes within a pilot RCT but intervention uptake was low. Although addition of these interventions to standard PN did not result in a difference between arms, overall PN uptake was higher than previously reported in similar settings, probably as a result of introducing a formal evaluation. Recruitment to an individually randomised trial proved challenging and full evaluation will likely require service-level randomisation. Registered UK Clinical Research Network Study Portfolio id number 10123. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Development of an aptamer-based concentration method for the detection of Trypanosoma cruzi in blood.

Directory of Open Access Journals (Sweden)

Rana Nagarkatti

Full Text Available Trypanosoma cruzi, a blood-borne parasite, is the etiological agent of Chagas disease. T. cruzi trypomastigotes, the infectious life cycle stage, can be detected in blood of infected individuals using PCR-based methods. However, soon after a natural infection, or during the chronic phase of Chagas disease, the number of parasites in blood may be very low and thus difficult to detect by PCR. To facilitate PCR-based detection methods, a parasite concentration approach was explored. A whole cell SELEX strategy was utilized to develop serum stable RNA aptamers that bind to live T. cruzi trypomastigotes. These aptamers bound to the parasite with high affinities (8-25 nM range. The highest affinity aptamer, Apt68, also demonstrated high specificity as it did not interact with the insect stage epimastigotes of T. cruzi nor with other related trypanosomatid parasites, L. donovani and T. brucei, suggesting that the target of Apt68 was expressed only on T. cruzi trypomastigotes. Biotinylated Apt68, immobilized on a solid phase, was able to capture live parasites. These captured parasites were visible microscopically, as large motile aggregates, formed when the aptamer coated paramagnetic beads bound to the surface of the trypomastigotes. Additionally, Apt68 was also able to capture and aggregate trypomastigotes from several isolates of the two major genotypes of the parasite. Using a magnet, these parasite-bead aggregates could be purified from parasite-spiked whole blood samples, even at concentrations as low as 5 parasites in 15 ml of whole blood, as detected by a real-time PCR assay. Our results show that aptamers can be used as pathogen specific ligands to capture and facilitate PCR-based detection of T. cruzi in blood.

Application of spectral hole burning to the study of in vitro cellular systems

Energy Technology Data Exchange (ETDEWEB)

Milanovich, Nebojsa [Iowa State Univ., Ames, IA (United States)

1999-11-08

Chapter 1 of this thesis describes the various stages of tumor development and a multitude of diagnostic techniques used to detect cancer. Chapter 2 gives an overview of the aspects of hole burning spectroscopy important for its application to the study of cellular systems. Chapter 3 gives general descriptions of cellular organelles, structures, and physical properties that can serve as possible markers for the differentiation of normal and cancerous cells. Also described in Chapter 3 are the principles of cryobiology important for low temperature spectroscopy of cells, characterization of MCF-10F (normal) and MCF-7 (cancer) cells lines which will serve as model systems, and cellular characteristics of aluminum phthalocyanine tetrasulfonate (APT), which was used as the test probe. Chapters 4 and 5 are previously published papers by the author pertaining to the results obtained from the application of hole burning to the study of cellular systems. Chapter 4 presents the first results obtained by spectral hole burning of cellular systems and Chapter 5 gives results for the differentiation of MCF-10F and MCF-7 cells stained with APT by an external applied electric (Stark) field. A general conclusion is presented in Chapter 6. Appendices A and B provide additional characterization of the cell/probe model systems. Appendix A describes the uptake and subcellular distribution of APT in MCF-10F and MCF-7 cells and Appendix B compares the hole burning characteristics of APT in cells when the cells are in suspension and when they are examined while adhering to a glass coverslip. Appendix C presents preliminary results for a novel probe molecule, referred to as a molecular thumbtack, designed by the authors for use in future hole burning applications to cellular systems.

Antiplatelet therapy is not a safer alternative to oral anticoagulants, even in older hospital-discharged patients with atrial fibrillation

Directory of Open Access Journals (Sweden)

Mario Bo

2016-10-01

Full Text Available Although oral anticoagulant therapy (OAT is recommended for patients with atrial fibrillation (AF, it is widely underused among older patients, who are frequently prescribed antiplatelet therapy (APT instead. We assessed mortality and incidence of ischemic and hemorrhagic events according to prescription of OAT or APT in older medical in-patients with AF discharged from hospital. Stroke and bleeding risk were evaluated using the CHA2DS2-VASC (Congestive heart failure/ left ventricular dysfunction, Hypertension, Aged ≥75 years, Diabetes Mellitus, Stroke/transient ischemic attack/systemic embolism, Vascular Disease, Aged 65-74 years, Sex Category and HAS-BLED (Hypertension, Abnormal renal/liver function, Stroke, Bleeding history or predisposition, Labile international normalized ratio, Elderly, Drugs/alcohol concomitantly scores. Comorbidity, cognitive status and functional autonomy were assessed using standardized scales. Association of OAT and APT with overall mortality, ischemic stroke and bleeding events was evaluated through multivariate analysis and propensity score matching. During a mean follow-up period of 11 months 384 of the 962 patients discharged (mean age 82.9±6.6 years, 59.1% female died (39.9%, 66 had an ischemic stroke and 49 experienced a major bleeding event. Compared with APT, OAT was associated with reduced overall mortality after multivariate analysis [odds ratio (OR 0.62, confidence interval (CI: 0.46-0.83] and after propensity score matched analysis (OR 0.65, CI: 0.52-0.82, P=0.0004, with a not significant reduced incidence of total and fatal ischemic stroke, and without increase in total, intracranial, major and fatal bleedings. In a sample of older AF patients with poor health status, OAT was associated with reduced mortality, without evidence of a significant increase in major or fatal bleedings.

Export of reactive nitrogen from coal-fired power plants in the U.S.: Estimates from a plume-in-grid modeling study - article no. D04308

Energy Technology Data Exchange (ETDEWEB)

Vijayaraghavan, K.; Zhang, Y.; Seigneur, C.; Karamchandani, P.; Snell, H.E.

2009-02-15

The export of reactive nitrogen (nitrogen oxides and their oxidation products, collectively referred to as NOy) from coal-fired power plants in the U.S. to the rest of the world could have a significant global contribution to ozone. Traditional Eulerian gridded air quality models cannot characterize accurately the chemistry and transport of plumes from elevated point sources such as power plant stacks. A state-of-the-science plume-in-grid (PinG) air quality model, a reactive plume model embedded in an Eulerian gridded model, is used to estimate the export of NOy from 25 large coal-fired power plants in the U. S. (in terms of NOx and SO{sub 2} emissions) in July 2001 to the global atmosphere. The PinG model used is the Community Multiscale Air Quality Model with Advanced Plume Treatment (CMAQ-APT). A benchmark simulation with only the gridded model, CMAQ, is also conducted for comparison purposes. The simulations with and without advanced plume treatment show differences in the calculated export of NOy from the 25 plants considered reflecting the effect of using a detailed and explicit treatment of plume transport and chemistry. The advanced plume treatment results in 31% greater simulated export of NOy compared to the purely grid-based modeling approach. The export efficiency of NOy (the fraction of NOy emitted that is exported) is predicted to be 21% without APT and 27% with APT. When considering only export through the eastern boundary across the Atlantic, CMAQ-APT predicts that the export efficiency is 24% and that 2% of NOy is exported as NOx, 49% as inorganic nitrate, and 25% as PAN. These results are in reasonably good agreement with an analysis reported in the literature of aircraft measurements over the North Atlantic.

Ground receiving station (GRS) of UMS - receiving and processing the electromagnetic wave data from satellite

International Nuclear Information System (INIS)

Mohammad Syahmi Nordin; Fauziah Abdul Aziz

2007-01-01

The low resolution Automatic Picture Transmission (APT) data from the National Oceanic and Atmospheric Administration (NOAA) polar-orbiting satellites Advanced Very High Resolution Radiometer (AVHRR) is being received and recorded in real-time mode at ground receiving station in School of Science and Technology, Universiti Malaysia Sabah. The system is suitable for the developing and undeveloped countries in south and Southeast Asia and is said to be acceptable for engineering, agricultural, climatological and environmental applications. The system comprises a personal computer attached with a small APT receiver. The data transmission between the ground receiving station and NOAA satellites is using the electromagnetic wave. The relation for receiving and processing the electromagnetic wave in the transmission will be discussed. (Author)

Luminescent Properties of Surface Functionalized BaTiO₃ Embedded in Poly(methyl methacrylate).

Science.gov (United States)

Requena, Sebastian; Lacoul, Srijan; Strzhemechny, Yuri M

2014-01-16

As-received BaTiO₃ nanopowders of average grain sizes 50 nm and 100 nm were functionalized by (3-aminopropyl)triethoxysilane (APTES) and mixed with poly(methyl methacrylate)/toluene solution. The nanocomposite solution was spin coated on Si substrates to form thin films. The photoluminescence spectrum of the pure powder was composed of a bandgap emission at 3.0 eV and multiple bands centered about 2.5 eV. Surface functionalization of the BaTiO₃ powder via APTES increases overall luminescence at room temperature while only enhancing bandgap emission at low-temperature. Polymer coating of the functionalized nanoparticles significantly enhances bandgap emissions while decreasing emissions associated with near-surface lattice distortions at 2.5 eV.

Characterizing amide proton transfer imaging in haemorrhage brain lesions using 3T MRI

Energy Technology Data Exchange (ETDEWEB)

Jeong, Ha-Kyu [Philips Korea, Seoul (Korea, Republic of); Korea Basic Science Institute, Chungcheongbuk-do (Korea, Republic of); Han, Kyunghwa [Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, Seodaemun-gu, Seoul (Korea, Republic of); Yonsei University College of Medicine, Yonsei Biomedical Research Institute, Seoul (Korea, Republic of); Zhou, Jinyuan [Johns Hopkins University School of Medicine, Division of MRI Research, Department of Radiology, Baltimore, MD (United States); Zhao, Yansong [Philips Healthcare, MR Clinical Science, Cleveland, OH (United States); Choi, Yoon Seong; Lee, Seung-Koo; Ahn, Sung Soo [Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, Seodaemun-gu, Seoul (Korea, Republic of)

2017-04-15

The aim of this study was to characterize amide proton transfer (APT)-weighted signals in acute and subacute haemorrhage brain lesions of various underlying aetiologies. Twenty-three patients with symptomatic haemorrhage brain lesions including tumorous (n = 16) and non-tumorous lesions (n = 7) were evaluated. APT imaging was performed and analyzed with magnetization transfer ratio asymmetry (MTR{sub asym}). Regions of interest were defined as the enhancing portion (when present), acute or subacute haemorrhage, and normal-appearing white matter based on anatomical MRI. MTR{sub asym} values were compared among groups and components using a linear mixed model. MTR{sub asym} values were 3.68 % in acute haemorrhage, 1.6 % in subacute haemorrhage, 2.65 % in the enhancing portion, and 0.38 % in normal white matter. According to the linear mixed model, the distribution of MTR{sub asym} values among components was not significantly different between tumour and non-tumour groups. MTR{sub asym} in acute haemorrhage was significantly higher than those in the other regions regardless of underlying pathology. Acute haemorrhages showed high MTR{sub asym} regardless of the underlying pathology, whereas subacute haemorrhages showed lower MTR{sub asym} than acute haemorrhages. These results can aid in the interpretation of APT imaging in haemorrhage brain lesions. (orig.)

A dual-color flow cytometry protocol for the simultaneous detection of Vibrio parahaemolyticus and Salmonella typhimurium using aptamer conjugated quantum dots as labels

Energy Technology Data Exchange (ETDEWEB)

Duan, Nuo; Wu, Shijia [State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122 (China); Yu, Ye [Zhangjiagang Entry-Exit Inspection and Quarantine Bureau, Zhangjiangang 215600 (China); Ma, Xiaoyuan; Xia, Yu; Chen, Xiujuan; Huang, Yukun [State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122 (China); Wang, Zhouping, E-mail: wangzp@jiangnan.edu.cn [State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122 (China)

2013-12-04

Graphical abstract: -- Highlights: •Two bacteria were simultaneously detected using QD-apt as labels by flow cytometry. •QD-apt were used for recognition and fluorescence detection of two bacteria. •The method was applied successfully for bacteria detection in real samples. -- Abstract: A sensitive, specific method for the collection and detection of pathogenic bacteria was demonstrated using quantum dots (QDs) as a fluorescence marker coupled with aptamers as the molecular recognition element by flow cytometry. The aptamer sequences were selected using a bacterium-based SELEX strategy in our laboratory for Vibrio parahaemolyticus and Salmonella typhimurium that, when applied in this method, allows for the specific recognition of the bacteria from complex mixtures including shrimp samples. Aptamer-modified QDs (QD-apt) were employed to selectively capture and simultaneously detect the target bacteria with high sensitivity using the fluorescence of the labeled QDs. The signal intensity is amplified due to the high photostability of QDs nanoparticles, resulting in improved sensitivity over methods using individual dye-labeled probes. This proposed method is promising for the sensitive detection of other pathogenic bacteria in food stuff if suitable aptamers are chosen. The method may also provide another potential platform for the application of aptamer-conjugated QDs in flow cytometry.

Improved adhesion of Ag NPs to the polyethylene terephthalate surface via atmospheric plasma treatment and surface functionalization

Energy Technology Data Exchange (ETDEWEB)

Shen, Tao [Faculty of Materials Science and Engineering, Kunming University of Science and Technology, 253 Xuefu Rd, Kunming, Yunnan, 650093 (China); Liu, Yong [Faculty of Materials Science and Engineering, Kunming University of Science and Technology, 253 Xuefu Rd, Kunming, Yunnan, 650093 (China); Solmont Technology Wuxi Co., Ltd. 228 Linghu Blvd. Tianan Tech Park, A1-602, Xinwu District, Wuxi, Jiangsu 214135 (China); Zhu, Yan, E-mail: zhuyan@kmust.edu.cn [Faculty of Materials Science and Engineering, Kunming University of Science and Technology, 253 Xuefu Rd, Kunming, Yunnan, 650093 (China); Yang, De-Quan, E-mail: dequan.yang@gmail.com [Faculty of Materials Science and Engineering, Kunming University of Science and Technology, 253 Xuefu Rd, Kunming, Yunnan, 650093 (China); Solmont Technology Wuxi Co., Ltd. 228 Linghu Blvd. Tianan Tech Park, A1-602, Xinwu District, Wuxi, Jiangsu 214135 (China); Sacher, Edward [Regroupement Québécois de Matériaux de Pointe, Department of Engineering Physics, École Polytechnique de Montréal, Case Postale 6079, succursale Centre-Ville, Montréal, Québec H3C 3A7 (Canada)

2017-07-31

Highlights: • A two-step process has been developed to enhance the adhesion of immobilized Ag NPs to the PET surface. • The method is simple, easy to use and low-cost for mass production. • The increased density of active sites (−OH, −CH=O and COOH) at the PET surface, after plasma treatment, permits increased reaction with 3-aminopropyltriethoxysilane (APTES). • The presence of APTES with high surface density permits −NH{sub 2}-Ag complex formation, increasing the adhesion of the Ag NPs. - Abstract: Ag nanoparticles (NPs) have been widely applied, as important antibacterial materials, on textile and polymer surfaces. However, their adhesion to nonreactive polymer surfaces is generally too weak for many applications. Here, we propose a two-step process, atmospheric plasma treatment followed by a surface chemical modification process, which enhances their adhesion to polyethylene terephthalate (PET) surfaces. We found that, compared to either plasma treatments or surface chemical functionalizations, alone, this combination greatly enhanced their adhesion. The plasma treatment resulted in an increase of active sites (−OH, −CH=O and COOH) at the PET surface, permitting increased bonding to 3-aminopropyltriethoxysilane (APTES), whose −NH{sub 2} groups were then able to form a bonding complex with the Ag NPs.

Attosecond Coherent Control of the Photo-Dissociation of Oxygen Molecules

Science.gov (United States)

Sturm, Felix; Ray, Dipanwita; Wright, Travis; Shivaram, Niranjan; Bocharova, Irina; Slaughter, Daniel; Ranitovic, Predrag; Belkacem, Ali; Weber, Thorsten

2016-05-01

Attosecond Coherent Control has emerged in recent years as a technique to manipulate the absorption and ionization in atoms as well as the dissociation of molecules on an attosecond time scale. Single attosecond pulses and attosecond pulse trains (APTs) can coherently excite multiple electronic states. The electronic and nuclear wave packets can then be coupled with a second pulse forming multiple interfering quantum pathways. We have built a high flux extreme ultraviolet (XUV) light source delivering APTs based on HHG that allows to selectively excite neutral and ion states in molecules. Our beamline provides spectral selectivity and attosecond interferometric control of the pulses. In the study presented here, we use APTs, generated by High Harmonic Generation in a high flux extreme ultraviolet light source, to ionize highly excited states of oxygen molecules. We identify the ionization/dissociation pathways revealing vibrational structure with ultra-high resolution ion 3D-momentum imaging spectroscopy. Furthermore, we introduce a delay between IR pulses and XUV/IR pulses to constructively or destructively interfere the ionization and dissociation pathways, thus, enabling the manipulation of both the O2+and the O+ ion yields with attosecond precision. Supported by DOE under Contract No. DE-AC02-05CH11231.

Photorefractive keratectomy in the management of postradial keratotomy hyperopia and astigmatism

Directory of Open Access Journals (Sweden)

Mohammad Ghoreishi

2017-01-01

Full Text Available Background: The aim of this study is to evaluate the results of photorefractive keratectomy (PRK in the management of postoperative hyperopia and astigmatism in patients with history of radial keratotomy (RK. Materials and Methods: This prospective nonrandomized noncomparative interventional case series enrolled consecutive eyes treated with PRK after RK. In cases, in which (1 wavefront (WF scan was undetectable during primary examinations; and/or, (2 WF data were not transferable to the excimer laser device, patients were treated with the tissue-saving (TS mode. Patients with detectable/transferable WF were assigned to WF-guided advanced personalized treatment (APT. Results: Thirty-two and 47 eyes were managed by APT and TS modes, respectively. Pooled analysis of both APT and TS groups showed improvement in uncorrected distant visual acuity and corrected distant visual acuity. The amount of sphere, cylinder, corneal cylinder, spherical equivalent, defocus equivalent, and total aberration showed improvement as well. Conclusion: PRK seems to bring favorable outcome and safety profile in the management of post-RK hyperopia and astigmatism. It is crucial for practitioners to warn their patients about the fact that they may still have progressive refractive instability regardless of their choice on the laser method of vision correction.

A dual-color flow cytometry protocol for the simultaneous detection of Vibrio parahaemolyticus and Salmonella typhimurium using aptamer conjugated quantum dots as labels

International Nuclear Information System (INIS)

Duan, Nuo; Wu, Shijia; Yu, Ye; Ma, Xiaoyuan; Xia, Yu; Chen, Xiujuan; Huang, Yukun; Wang, Zhouping

2013-01-01

Graphical abstract: -- Highlights: •Two bacteria were simultaneously detected using QD-apt as labels by flow cytometry. •QD-apt were used for recognition and fluorescence detection of two bacteria. •The method was applied successfully for bacteria detection in real samples. -- Abstract: A sensitive, specific method for the collection and detection of pathogenic bacteria was demonstrated using quantum dots (QDs) as a fluorescence marker coupled with aptamers as the molecular recognition element by flow cytometry. The aptamer sequences were selected using a bacterium-based SELEX strategy in our laboratory for Vibrio parahaemolyticus and Salmonella typhimurium that, when applied in this method, allows for the specific recognition of the bacteria from complex mixtures including shrimp samples. Aptamer-modified QDs (QD-apt) were employed to selectively capture and simultaneously detect the target bacteria with high sensitivity using the fluorescence of the labeled QDs. The signal intensity is amplified due to the high photostability of QDs nanoparticles, resulting in improved sensitivity over methods using individual dye-labeled probes. This proposed method is promising for the sensitive detection of other pathogenic bacteria in food stuff if suitable aptamers are chosen. The method may also provide another potential platform for the application of aptamer-conjugated QDs in flow cytometry

Barriers and Facilitators of Partner Treatment of Chlamydia: A Qualitative Investigation with Prescribers and Community Pharmacists

Directory of Open Access Journals (Sweden)

Helen Wood

2018-02-01

Full Text Available Chlamydia trachomatis is the most frequently-notified sexually transmitted infection in Australia. Effective and timely partner treatment of chlamydia is essential to reduce overall prevalence and the burden of infection. Currently in most of Australia, the only avenue for partner treatment of chlamydia (“standard partner therapy” is a tedious, and often inconvenient, process. The barriers and facilitators of standard partner therapy, and newer models of accelerated partner therapy (APT, need to be identified in the Australian setting. Additionally, the potential role of community pharmacists need to be explored. Semi-structured interview guides for two key stakeholder groups (prescribers and pharmacists were developed and piloted. Eleven prescribers (general practitioners, sexual health clinicians and nurse practitioners and twelve pharmacists practicing in the Perth metropolitan region were interviewed. Key reported barriers to standard partner therapy were lack of or delayed chlamydia testing. Key facilitators included ability to test and educate sexual partner. Key barriers for APT included prescribers’ legal responsibility and potential for medication-related adverse effects. Healthcare provider consultation and chlamydia testing were seen as potential facilitators of APT. Pharmacists were receptive to the idea of expanding their role in chlamydia treatment, however, barriers to privacy must be overcome in order to be acceptable to prescribers and pharmacists.

Synergistic effects of iodine and silver ions co-implanted in 6H-SiC

Science.gov (United States)

Kuhudzai, R. J.; Malherbe, J. B.; Hlatshwayo, T. T.; van der Berg, N. G.; Devaraj, A.; Zhu, Z.; Nandasiri, M.

2015-12-01

Motivated by the aim of understanding the release of fission products through the SiC coating of fuel kernels in modern high temperature nuclear reactors, a fundamental investigation is conducted to understand the synergistic effects of implanted silver (Ag) and iodine (I) in 6H-SiC. The implantation of the individual species, as well as the co-implantation of 360 keV ions of I and Ag at room temperature in 6H-SiC and their subsequent annealing behaviour has been investigated by Secondary Ion Mass Spectrometry (SIMS), Atom Probe Tomography (APT) and X-ray Photoelectron Spectroscopy (XPS). SIMS and APT measurements indicated the presence of Ag in the co-implanted samples after annealing at 1500 °C for 30 h in sharp contrast to the samples implanted with Ag only. In samples implanted with Ag only, complete loss of the implanted Ag was observed. However, for I only implanted samples, some iodine was retained. APT of annealed co-implanted 6H-SiC showed clear spatial association of Ag and I clusters in SiC, which can be attributed to the observed I assisted retention of Ag after annealing. Such detailed studies will be necessary to identify the fundamental mechanism of fission products migration through SiC coatings.

Impact of Petrophysical Properties on Hydraulic Fracturing and Development in Tight Volcanic Gas Reservoirs

Directory of Open Access Journals (Sweden)

Yinghao Shen

2017-01-01

Full Text Available The volcanic reservoir is an important kind of unconventional reservoir. The aqueous phase trapping (APT appears because of fracturing fluids filtration. However, APT can be autoremoved for some wells after certain shut-in time. But there is significant distinction for different reservoirs. Experiments were performed to study the petrophysical properties of a volcanic reservoir and the spontaneous imbibition is monitored by nuclear magnetic resonance (NMR and pulse-decay permeability. Results showed that natural cracks appear in the samples as well as high irreducible water saturation. There is a quick decrease of rock permeability once the rock contacts water. The pores filled during spontaneous imbibition are mainly the nanopores from NMR spectra. Full understanding of the mineralogical effect and sample heterogeneity benefits the selection of segments to fracturing. The fast flow-back scheme is applicable in this reservoir to minimize the damage. Because lots of water imbibed into the nanopores, the main flow channels become larger, which are beneficial to the permeability recovery after flow-back of hydraulic fracturing. This is helpful in understanding the APT autoremoval after certain shut-in time. Also, Keeping the appropriate production differential pressure is very important in achieving the long term efficient development of volcanic gas reservoirs.

Attention Process Training-3 to improve reading comprehension in mild aphasia: A single-case experimental design study.

Science.gov (United States)

Lee, Jaime B; Sohlberg, McKay Moore; Harn, Beth; Horner, Robert; Cherney, Leora R

2018-06-04

People with aphasia frequently present with nonlinguistic deficits, in addition to their compromised language abilities, which may contribute to their problems with reading comprehension. Treatment of attention, working memory and executive control may improve reading comprehension in individuals with aphasia, particularly those with mild reading problems. This single-case experimental design study evaluated the efficacy of Attention Process Training-3, an intervention combining direct attention training and metacognitive facilitation, for improving reading comprehension in individuals with mild aphasia. A multiple baseline design across six participants was used to evaluate treatment effects. The primary outcome measure was a maze reading task. Cognitive measures were administered pre- and post-treatment. Visual inspection of graphed maze reading performance data indicated a basic effect between APT-3 and improved maze reading for three of the six participants. Quantitative analyses, using Tau-U, corroborated findings identified through visual analysis. The overall effect size was significant (Tau = .48, p = .01). Results suggest that APT-3 has the potential to improve reading in individuals with aphasia, but that it may be more efficacious under certain conditions. Treatment and participant variables, including intensity of treatment and metacognitive strategy usage, are discussed as potential influences on participants' responsiveness to APT-3.

Molecular imprinting at walls of silica nanotubes for TNT recognition.

Science.gov (United States)

Xie, Chenggen; Liu, Bianhua; Wang, Zhenyang; Gao, Daming; Guan, Guijian; Zhang, Zhongping

2008-01-15

This paper reports the molecular imprinting at the walls of highly uniform silica nanotubes for the recognition of 2,4,6-trinitrotoluene (TNT). It has been demonstrated that TNT templates were efficiently imprinted into the matrix of silica through the strong acid-base pairing interaction between TNT and 3-aminopropyltriethoxysilane (APTS). TNT-imprinted silica nanotubes were synthesized by the gelation reaction between APTS and tetraethylorthosilicate (TEOS), selectively occurring at the porous walls of APTS-modified alumina membranes. The removal of the original TNT templates leaves the imprinted cavities with covalently anchored amine groups at the cavity walls. A high density of recognition sites with molecular selectivity to the TNT analyte was created at the wall of silica nanotubes. Furthermore, most of these recognition sites are situated at the inside and outside surfaces of tubular walls and in the proximity of the two surfaces due to the ultrathin wall thickness of only 15 nm, providing a better site accessibility and lower mass-transfer resistance. Therefore, greater capacity and faster kinetics of uptaking target species were achieved. The silica nanotube reported herein is an ideal form of material for imprinting various organic or biological molecules toward applications in chemical/biological sensors and bioassay.

Controlled drug release on amine functionalized spherical MCM-41

International Nuclear Information System (INIS)

Szegedi, Agnes; Popova, Margarita; Goshev, Ivan; Klébert, Szilvia; Mihály, Judit

2012-01-01

MCM-41 silica with spherical morphology and small particle sizes (100 nm) was synthesized and modified by post-synthesis method with different amounts of 3-aminopropyltriethoxysilane (APTES). A comparative study of the adsorption and release of a model drug, ibuprofen, was carried out. The modified and drug loaded mesoporous materials were characterized by XRD, TEM, N 2 physisorption, elemental analysis, thermal analysis and FT-IR spectroscopy. A new method was developed for the quantitative determination of amino groups in surface modified mesoporous materials by the ninhydrin reaction. Good correlation was found between the amino content of the MCM-41 materials determined by the ninhydrin method and their ibuprofen adsorption capacity. Amino modification resulted in high degree of ibuprofen loading and slow release rate in comparison to the parent non-modified MCM-41. - Graphical abstract: Determination of surface amino groups by ninhidrin method. Highlights: ► Spherical MCM-41 modified by different amounts of APTES was studied. ► Ibuprofen (IBU) adsorption and release characteristics was tested. ► The ninhydrin reaction was used for the quantitative determination of amino groups. ► Stoichiometric amount of APTES is enough for totally covering the surface with amino groups. ► Good correlation was found between the amino content and IBU adsorption capacity.

Role of Fabrication on Materials Compatibility in APT Target/Blanket

International Nuclear Information System (INIS)

Iyer, N.; Louthan, M.R. Jr.; Dunn, K.; Fisher, D.L.

1998-09-01

This paper summarizes several of the options associated with the fabrication of selected target/blanket components. In addition, the materials characterization technologies required to validate these components performance is presented

Physics design of APT linac with normal conducting rf cavities

International Nuclear Information System (INIS)

Nath, S.; Billen, J.H.; Stovall, J.E.; Takeda, Harunori; Young, L.M.

1996-01-01

The accelerator based production of tritium calls for a high-power, cw proton linac. Previous designs for such a linac use a radiofrequency quadrupole (RFQ), followed by a drift-tube linac (DTL) to an intermediate energy and a coupled-cavity linc (CCL) to the final energy. The Los Alamos design uses a high-energy (6.7 MeV) RFQ followed by the newly developed coupled-cavity drift-tube linac (CCDTL) and a CCL. This design accommodates external electromagnetic quadrupole lenses which provide a strong uniform focusing lattice from the end of the RFQ to the end of the CCL. The cell lengths in linacs of traditional design are typically graded as a function of particle velocity. By making groups of cells symmetric in both the CCDTL and CCL, the cavity design as well as mechanical design and fabrication is simplified without compromising the performance. At higher energies, there are some advantages of using superconducting rf cavities. Currently, such schemes are under vigorous study. This paper describes the linac design based on normal conducting cavities and presents simulation results

Accelerator Production of Tritium Waste Characterization and Certification Challenges

International Nuclear Information System (INIS)

Ades, M.J.; England, J.L.; Nowacki, P.L.; Hane, R.; Tempel, K.L.; Pitcher, E.; Cohen, H.S.

1998-06-01

This paper summaries the processes and methods APT used for the identification and classification of the waste streams, the characterization and certification of the waste streams, and waste minimization

Shanbhag, Prof. Bhagyashri Achut

Indian Academy of Sciences (India)

. (Karnatak), FNA, FNASc. Date of birth: 2 November 1950. Specialization: Comparative Endocrinology & Reproduction (Vertebrates), Herpetology and Animal Behaviour Address: FF-4, Trigunatmika Apts., Haliyal Road, Dharwad 580 001, ...

Clinical implications of self-representations

Indian Academy of Sciences (India)

2016-01-15

Jan 15, 2016 ... self has become an important focus in cognitive neuroscience in ... However, this 'motivational' evolutionary psychology approach to etiology is somewhat circular .... dependent development of self-representations aptly:.

76 FR 76411 - Ocean Transportation Intermediary License; Applicants

Science.gov (United States)

2011-12-07

... Avenue, Apt. A, Monterey Park, CA 91755-2044, Officers: Li Lin, General Manager/Sec/CFO, (Qualifying.... Suddath Global Logistics, LLC dba Suddath Global Logistics, (NVO & OFF), 815 South Main Street...

Environmental restoration/waste management-applied technology semiannual report, January--June 1992

International Nuclear Information System (INIS)

Adamson, M.; Kline-Simon, K.

1992-01-01

This is the first issue from the Lawrence Livermore National Laboratory of The Environmental Restoration/Waste Management-Applied Technology (ER/WM-AT) Semiannual Report, a continuation of the Advanced Processing Technology (APT) Semiannual Report. The name change reflects the consolidation of the APT Program with the Environmental Restoration and Waste Management Program to form the Environmental Restoration/Waste Management-Applied Technology (ER/WM-AT) Program. The Livermore site mirrors, on a small scale, many of the environmental and waste management problems of the DOE Complex. The six articles in this issue cover incineration- alternative technologies, process development for waste minimization, the proposed Mixed Waste Management Facility, dynamic underground stripping, electrical resistance tomography, and Raman spectroscopy for remote characterization of underground tanks

Organically Modified Saponites: SAXS Study of Swelling and Application in Caffeine Removal.

Science.gov (United States)

Marçal, Liziane; de Faria, Emerson H; Nassar, Eduardo J; Trujillano, Raquel; Martín, Nuria; Vicente, Miguel A; Rives, Vicente; Gil, Antonio; Korili, Sophia A; Ciuffi, Katia J

2015-05-27

This study aimed to assess the capacity of saponite modified with n-hexadecyltrimethylammonium bromide (CTAB) and/or 3-aminopropyltriethoxysilane (APTS) to adsorb and remove caffeine from aqueous solutions. Powder X-ray diffraction (PXRD) revealed increased basal spacing in the modified saponites. Small-angle X-ray scattering (SAXS) confirmed the PXRD results; it also showed how the different clay layers were stacked and provided information on the swelling of natural saponite and of the saponites functionalized with CTAB and/or APTS. Thermal analyses, infrared spectroscopy, scanning electron microscopy, element chemical analysis, and textural analyses confirmed functionalization of the natural saponite. The maximum adsorption capacity at equilibrium was 80.54 mg/g, indicating that the saponite modified with 3-aminopropyltriethoxysilane constitutes an efficient and suitable caffeine adsorbent.

Characterization of microstructural strengthening in the heat-affected zone of a blast-resistant naval steel

Energy Technology Data Exchange (ETDEWEB)

Yu Xinghua, E-mail: yu.345@osu.edu [Department of Materials Science and Engineering, Ohio State University, Columbus, OH 43221 (United States); Caron, Jeremy L. [Department of Materials Science and Engineering, Ohio State University, Columbus, OH 43221 (United States)] [Welding and Joining Metallurgy Group, Welding Engineering Program, 1248 Arthur E. Adams Drive, Ohio State University, Columbus, OH 43221 (United States); Babu, S.S., E-mail: babu.13@osu.edu [Department of Materials Science and Engineering, Ohio State University, Columbus, OH 43221 (United States) and Welding and Joining Metallurgy Group, Welding Engineering Program, 1248 Arthur E. Adams Drive, Ohio State University, Columbus, OH 43221 (United States); Lippold, John C. [Department of Materials Science and Engineering, Ohio State University, Columbus, OH 43221 (United States)] [Welding and Joining Metallurgy Group, Welding Engineering Program, 1248 Arthur E. Adams Drive, Ohio State University, Columbus, OH 43221 (United States); Isheim, Dieter; Seidman, David N. [Department of Materials Science and Engineering, Northwestern University, 2220 North Campus Drive, Evanston, IL 60208 (United States)] [Northwestern University Center for Atom-Probe Tomography, 2220 North Campus Drive, Evanston, IL 60208 (United States)

2010-10-15

The influence of simulated heat-affected zone thermal cycles on the microstructural evolution in a blast-resistant naval steel was investigated by dilatometry, microhardness testing, optical microscopy, electron backscatter diffraction and atom-probe tomography (APT) techniques. Coarsening of Cu precipitates were observed in the subcritical and intercritical heat-affected zones, with partial dissolution in the latter. A small number density of Cu precipitates and high Cu concentration in the matrix of the fine-grained heat-affected zone indicates the onset of Cu precipitate dissolution. Cu clustering in the coarse-grained heat-affected zone indicated the potential initiation of Cu reprecipitation during cooling. Segregation of Cu was also characterized by APT. The hardening and softening observed in the heat-affected zone regions was rationalized using available strengthening models.

Luminescent Properties of Surface Functionalized BaTiO3 Embedded in Poly(methyl methacrylate)

Science.gov (United States)

Requena, Sebastian; Lacoul, Srijan; Strzhemechny, Yuri M.

2014-01-01

As-received BaTiO3 nanopowders of average grain sizes 50 nm and 100 nm were functionalized by (3-aminopropyl)triethoxysilane (APTES) and mixed with poly(methyl methacrylate)/toluene solution. The nanocomposite solution was spin coated on Si substrates to form thin films. The photoluminescence spectrum of the pure powder was composed of a bandgap emission at 3.0 eV and multiple bands centered about 2.5 eV. Surface functionalization of the BaTiO3 powder via APTES increases overall luminescence at room temperature while only enhancing bandgap emission at low-temperature. Polymer coating of the functionalized nanoparticles significantly enhances bandgap emissions while decreasing emissions associated with near-surface lattice distortions at 2.5 eV. PMID:28788468

Luminescent Properties of Surface Functionalized BaTiO3 Embedded in Poly(methyl methacrylate

Directory of Open Access Journals (Sweden)

Sebastian Requena

2014-01-01

Full Text Available As-received BaTiO3 nanopowders of average grain sizes 50 nm and 100 nm were functionalized by (3-aminopropyltriethoxysilane (APTES and mixed with poly(methyl methacrylate/toluene solution. The nanocomposite solution was spin coated on Si substrates to form thin films. The photoluminescence spectrum of the pure powder was composed of a bandgap emission at 3.0 eV and multiple bands centered about 2.5 eV. Surface functionalization of the BaTiO3 powder via APTES increases overall luminescence at room temperature while only enhancing bandgap emission at low-temperature. Polymer coating of the functionalized nanoparticles significantly enhances bandgap emissions while decreasing emissions associated with near-surface lattice distortions at 2.5 eV.

Surface Functionalization of WO3 Thin Films with (3-Aminopropyl)triethoxysilane and Succinic Anhydride

Science.gov (United States)

Ta, Thi Kieu Hanh; Tran, Thi Nhu Hoa; Tran, Quang Minh Nhat; Pham, Duy Phong; Pham, Kim Ngoc; Cao, Thi Thanh; Kim, Yong Soo; Tran, Dai Lam; Ju, Heongkyu; Phan, Bach Thang

2017-06-01

We report effects of oxygen plasma treatment on the surface functionalization of WO3 thin films with (3-aminopropyl)triethoxysilane (APTES) and succinic anhydride (SA). X-ray diffraction and x-ray photoelectron spectroscopy results indicate the existence of the WO3 phase. Fourier transform infrared spectroscopy measurement shows clear bands at 1040 cm-1 (Si-O-Si), 1556 cm-1 (N-H), 1655 cm-1 (C=O), 2937 cm-1 (C-H) and 3298 cm-1 (N-H), confirming the surface functionalization efficiency enhanced by prior treatment of oxygen plasma. It thus follows that the prior oxygen plasma treatment activates hydroxylation with more -OH groups on the WO3 surface, which can pave a highly efficient way to the surface functionalization by APTES and SA.

Eroding market stability by proliferation of financial instruments

Science.gov (United States)

Caccioli, F.; Marsili, M.; Vivo, P.

2009-10-01

We contrast Arbitrage Pricing Theory (APT), the theoretical basis for the development of financial instruments, with a dynamical picture of an interacting market, in a simple setting. The proliferation of financial instruments apparently provides more means for risk diversification, making the market more efficient and complete. In the simple market of interacting traders discussed here, the proliferation of financial instruments erodes systemic stability and it drives the market to a critical state characterized by large susceptibility, strong fluctuations and enhanced correlations among risks. This suggests that the hypothesis of APT may not be compatible with a stable market dynamics. In this perspective, market stability acquires the properties of a common good, which suggests that appropriate measures should be introduced in derivative markets, to preserve stability. in here

Interpretation of atom probe tomography data for the intermetallic TiAl+Nb by means of field evaporation simulation

KAUST Repository

Boll, Torben

2013-01-01

In this paper simulations of the field evaporation process during field ion microscopy (FIM) and atom probe tomography (APT) are presented and compared with experimental data. The Müller-Schottky-model [1] was extended to include the local atomic arrangement on the evaporation process of atoms. This arrangement was described by the sum of the next-neighbor-binding-energies, which differ for an atom of type A, depending on how many A-A, B-B or A-B bonds are present. Thus simulations of APT-data of intermetallic phases become feasible. In this study simulations of L10-TiAl with additions of Nb are compared with experimental data. Certain artifacts, which appear for experimental data are treated as well. © 2012 Elsevier B.V.

Learning and nuclear safety: New reactors and US regulation

International Nuclear Information System (INIS)

Nichols, E.; Wildavsky, A.

1992-01-01

Gathering and analyzing data from operating reactors has become part of government and industry programs to improve performance in plants already on line and to inform development of future reactors. In the United States, however, early development and certain other factors combined to encourage a bias in learning. Regulation and learning from operational data intersect in ways that limit participation, data collection, and positive response to findings. Past learning has shown the advantage of simpler more standard designs with passive or inherent safety features. However, even designs incorporating these past lessons are apt to face tough regulatory tests and much criticism as operating experience is gathered. Only the operational success of new standardized reactors is apt to help rationalize regulation. (orig.)

Advanced Public Transportation Systems. Technical Assistance Brief 2

Science.gov (United States)

1993-01-01

The Advanced Public Transportation Systems (APTS) Program requires evaluation : of pilot projects. This technical assistance brief discusses the guidelines set : for developing evaluation framework and methodology for local projects. 4p.

Advanced public transportation system deployment in the United States

Science.gov (United States)

1999-01-01

This report documents work performed under FTA's Advanced Public Transportation Systems (APTS) Program, a program structured to undertake research and development of innovative applications of advanced navigation, information, and communication techn...

Benefits assessment of advanced public transportation system technologies, update 2000

Science.gov (United States)

This report was performed under the Federal Transit Administration's (FTA) Advanced Public Transportation Systems (APTS) Program. This program focuses on the development and demonstration of innovative advanced navigation, information and communicati...

Accelerated testing for studying pavement design and performance (FY 2004) : research summary.

Science.gov (United States)

2009-03-01

The thirteenth full-scale Accelerated Pavement Test (APT) experiment at the Civil Infrastructure Laboratory (CISL) of Kansas State University aimed to determine the response and the failure mode of thin concrete overlays.

A simple and sensitive methodology for voltammetric determination of valproic acid in human blood plasma samples using 3-aminopropyletriethoxy silane coated magnetic nanoparticles modified pencil graphite electrode.

Science.gov (United States)

Zabardasti, Abedin; Afrouzi, Hossein; Talemi, Rasoul Pourtaghavi

2017-07-01

In this work, we have prepared a nano-material modified pencil graphite electrode for the sensing of valproic acid (VA) by immobilization 3-aminopropyletriethoxy silane coated magnetic nanoparticles (APTES-MNPs) on the pencil graphite surface (PGE). Electrochemical studies indicated that the APTES-MNPs efficiently increased the electron transfer kinetics between VA and the electrode and the free NH 2 groups of the APTES on the outer surface of magnetic nanoparticles can interact with carboxyl groups of VA. Based on this, we have proposed a sensitive, rapid and convenient electrochemical method for VA determination. Under the optimized conditions, the reduction peak current of VA is found to be proportional to its concentration in the range of 1.0 (±0.2) to 100.0 (±0.3) ppm with a detection limit of 0.4 (±0.1) ppm. The whole sensor fabrication process was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods with using [Fe(CN) 6 ] 3-/4- as an electrochemical redox indicator. The prepared modified electrode showed several advantages such as high sensitivity, selectivity, ease of preparation and good repeatability, reproducibility and stability. The proposed method was applied to determination of valproic acid in blood plasma samples and the obtained results were satisfactory accurate. Copyright © 2017. Published by Elsevier B.V.

Phase stability in thermally-aged CASS CF8 under heavy ion irradiation

Energy Technology Data Exchange (ETDEWEB)

Li, Meimei, E-mail: mli@anl.gov [Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Miller, Michael K. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Chen, Wei-Ying [Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States)

2015-07-15

Highlights: • Thermally-aged CF8 was irradiated with 1 MeV Kr ions at 400 °C. • Atom probe tomography revealed a strong dose dependence of G-phase precipitates. • Phase separation of α and α′ in ferrite was reduced after irradiation. - Abstract: The stability of the microstructure of a cast austenitic stainless steel (CASS), before and after heavy ion irradiation, was investigated by atom probe tomography (APT). A CF8 ferrite–austenite duplex alloy was thermally aged at 400 °C for 10,000 h. After this treatment, APT revealed nanometer-sized G-phase precipitates and Fe-rich α and Cr-enriched α′ phase separated regions in the ferrite. The thermally-aged CF8 specimen was irradiated with 1 MeV Kr ions to a fluence of 1.88 × 10{sup 19} ions/m{sup 2} at 400 °C. After irradiation, APT analysis revealed a strong spatial/dose dependence of the G-phase precipitates and the α–α′ spinodal decomposition in the ferrite. For the G-phase precipitates, the number density increased and the mean size decreased with increasing dose, and the particle size distribution changed considerably under irradiation. The inverse coarsening process can be described by recoil resolution. The amplitude of the α–α′ spinodal decomposition in the ferrite was apparently reduced after heavy ion irradiation.

The age related slow and fast contributions to the overall changes in tibialis anterior contractile features disclosed by maximal single twitch scan.

Science.gov (United States)

Orizio, Claudio; Cogliati, Marta; Bissolotti, Luciano; Diemont, Bertrand; Gobbo, Massimiliano; Celichowski, Jan

2016-01-01

This work aimed to verify if maximal electrically evoked single twitch (STmax) scan discloses the relative functional weight of fast and slow small bundles of fibres (SBF) in determining the contractile features of tibialis anterior (TA) with ageing. SBFs were recruited by TA main motor point stimulation through 60 increasing levels of stimulation (LS): 20 stimuli at 2Hz for each LS. The lowest and highest LS provided the least ST and STmax, respectively. The scanned STmax was decomposed into individual SBF STs. They were identified when twitches from adjacent LS were significantly different and then subtracted from each other. Nine young (Y) and eleven old (O) subjects were investigated. Contraction time (CT) and STarea/STpeak (A/PT) were calculated per each SBF ST. 143 and 155 SBF STs were obtained in Y and O, respectively. Y: CT and A/PT range: 45-105ms and 67-183mNs/mN, respectively. Literature data set TA fast fibres at 34% so, from the arrays of CT and A/PT, 65ms and 100mNs/mN were identified as the upper limit for SBF fast ST classification. O: no SBF ST could be classified as fast. STmax scan reveals age-related changes in the relative contribution of fast and slow SBFs to the overall muscle mechanics. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Application of Gold Nanoparticles for Electrochemical DNA Biosensor

Directory of Open Access Journals (Sweden)

Ahmed Mishaal Mohammed

2014-01-01

Full Text Available An electrochemical DNA biosensor was successfully fabricated by using (3-aminopropyltriethoxysilane (APTES as a linker molecule combined with the gold nanoparticles (GNPs on thermally oxidized SiO2 thin films. The SiO2 thin films surface was chemically modified with a mixture of APTES and GNPs for DNA detection in different time periods of 30 min, 1 hour, 2 hours, and 4 hours, respectively. The DNA immobilization and hybridization were conducted by measuring the differences of the capacitance value within the frequency range of 1 Hz to 1 MHz. The capacitance values for DNA immobilization were 160 μF, 77.8 μF, 70 μF, and 64.6 μF, respectively, with the period of time from 30 min to 4 hours. Meanwhile the capacitance values for DNA hybridization were 44 μF, 54 μF, 55 μF, and 61.5 μF, respectively. The capacitance value of bare SiO2 thin film was 0.42 μF, which was set as a base line for a reference in DNA detection. The differences of the capacitance value between the DNA immobilization and hybridization revealed that the modified SiO2 thin films using APTES and GNPs were successfully developed for DNA detection.

Controlled drug release on amine functionalized spherical MCM-41

Energy Technology Data Exchange (ETDEWEB)

Szegedi, Agnes, E-mail: szegedi@chemres.hu [Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1025 Budapest, Pusztaszeri ut 59-67 (Hungary); Popova, Margarita; Goshev, Ivan [Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia (Bulgaria); Klebert, Szilvia [Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1025 Budapest, Pusztaszeri ut 59-67 (Hungary); Mihaly, Judit [Institute of Molecular Pharmacology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1025 Budapest, Pusztaszeri ut 59-67 (Hungary)

2012-10-15

MCM-41 silica with spherical morphology and small particle sizes (100 nm) was synthesized and modified by post-synthesis method with different amounts of 3-aminopropyltriethoxysilane (APTES). A comparative study of the adsorption and release of a model drug, ibuprofen, was carried out. The modified and drug loaded mesoporous materials were characterized by XRD, TEM, N{sub 2} physisorption, elemental analysis, thermal analysis and FT-IR spectroscopy. A new method was developed for the quantitative determination of amino groups in surface modified mesoporous materials by the ninhydrin reaction. Good correlation was found between the amino content of the MCM-41 materials determined by the ninhydrin method and their ibuprofen adsorption capacity. Amino modification resulted in high degree of ibuprofen loading and slow release rate in comparison to the parent non-modified MCM-41. - Graphical abstract: Determination of surface amino groups by ninhidrin method. Highlights: Black-Right-Pointing-Pointer Spherical MCM-41 modified by different amounts of APTES was studied. Black-Right-Pointing-Pointer Ibuprofen (IBU) adsorption and release characteristics was tested. Black-Right-Pointing-Pointer The ninhydrin reaction was used for the quantitative determination of amino groups. Black-Right-Pointing-Pointer Stoichiometric amount of APTES is enough for totally covering the surface with amino groups. Black-Right-Pointing-Pointer Good correlation was found between the amino content and IBU adsorption capacity.

Advanced public transportation systems : the state of the art

Science.gov (United States)

1991-03-01

This report documents one of the early initiatives of UMTA's Advanced Public Transportation Systems (APTS) Program, a program structured to undertake research and development of innovative applications of advanced navigation, information, and communi...

Can a Diary Encourage Others to be Citizen Scientists?

Directory of Open Access Journals (Sweden)

Jerry H. Kavouras

2015-08-01

Full Text Available Review of: Diary of a Citizen Scientist Chasing Tiger Beetles and Other New Ways of Engaging the World; Sharman Apt Russell; (2014. Oregon State University Press, Corvallis, OR. 222 pages.

GIS applied to agriclimatological zoning and agrotoxin residue monitoring in tomatoes: A case study in Espírito Santo state, Brazil.

Science.gov (United States)

dos Santos, Gleissy Mary Amaral Dino Alves; Dos Santos, Alexandre Rosa; Teixeira, Luciano José Quintão; Saraiva, Sérgio Henriques; Freitas, Deivid França; Pereira, Olavo dos Santos; Ribeiro, Carlos Antonio Alvares Soares; Lorenzon, Alexandre Simões; Eugenio, Fernando Coelho; Neves, Antônio Augusto; de Queiroz, Maria Eliana Lopes Ribeiro; Scherer, Rodrigo

2016-01-15

Searches related to global warming have provided important insights into the response of terrestrial ecosystems, but few have examined the impacts on agricultural crops, particularly those associated with the monitoring of agrotoxin residues. In this context, the agriclimatological zoning is an important tool in the planning and consolidation of crops and should be considered in any initiative that involves such planning. This tool is particularly important in the analysis of agrotoxin residues and may be applied by the Program Analysis of Agrotoxin Residues in Food (PARA) created by the National Health Vigilance Agency of Brazil (ANVISA), which enables greater food security and contributes to the improvement of human health. The aim of this study was to elaborate the current and future agriclimatological zoning for the tomato crop, relating it with the monitoring of samples collected by PARA in Espírito Santo State, Brazil. The results indicate that a temperature increase of 5 °C creates a decrease in apt areas from 37.3% to 4.3%, for a total reduction of 33 percentage points (-88.5%). It is noted that of the 41 producing municipalities, only 26 have apt areas greater than 50%, highlighting the municipalities with apt areas greater than 90%, represented by Mantenópolis (100%), Guaçuí (98.5%), São José do Calçado (97.8%), Irupi (94.4%), Santa Teresa (92.3%), and Marechal Floriano (91.4%). The veracity of agriclimatological zoning is proved by a Kendall rank correlation coefficient of 0.876, indicating that the distribution of the variables of apt areas and productivity are similar at the significance level of 0.05 with a confidence interval 95%. After validation of the agriclimatological zoning for the tomato crop, it is recommended that the PARA should monitor 36 municipalities rather than the current 18, representing an increase of 100%. The methodology can be adjusted to agricultural crops of other countries. Copyright © 2015 Elsevier Ltd. All rights

Poison Ivy Dermatitis

Science.gov (United States)

... Category: Share: Yes No, Keep Private Poison Ivy Dermatitis Share | "Leaves of three - let it be!" aptly ... is caused by an allergic reaction ( allergic contact dermatitis ) to the oily coating that covers of these ...

Application of image editing software for forensic detection of image ...

African Journals Online (AJOL)

Application of image editing software for forensic detection of image. ... The image editing software's available today is apt for creating visually compelling and sophisticated fake images, ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

Accelerated testing for studying pavement design and performance (FY 2003) : evaluation of the chemical stabilized subgrade soil (CISL Experiment No. 12).

Science.gov (United States)

2008-01-01

The Midwest States Accelerated Pavement Testing Pooled Fund Program, financed by the highway departments : of Missouri, Iowa, Kansas and Nebraska, has supported an accelerated pavement testing (APT) project to compare : the performance of stabilized ...

Verification of mechanistic-empirical design models for flexible pavements through accelerated pavement testing : technical summary.

Science.gov (United States)

2014-08-01

Midwest States Accelerated Pavement Testing Pooled-Fund Program, financed by the : highway departments of Kansas, Iowa, and Missouri, has supported an accelerated : pavement testing (APT) project to validate several models incorporated in the NCHRP :...

Accelerated testing for studying pavement design and performance (FY 2003) : research summary.

Science.gov (United States)

2008-01-01

The Midwest States Accelerated Pavement Testing Pooled Fund Program, financed by : the highway departments of Missouri, Iowa, Kansas and Nebraska, has supported an : accelerated pavement testing (APT) project to compare the performance of stabilized ...

Development of Conformal Ablative Thermal Protection Material and Fabrication Process

Data.gov (United States)

National Aeronautics and Space Administration — An entering spacecraft must decelerate from speeds of kilometers per second to zero in the span of only minutes a sequence aptly dubbed Seven Minutes of Terror on...

Tool for Two Types of Friction Stir Welding

Science.gov (United States)

Carter, Robert

2006-01-01

A tool that would be useable in both conventional and self-reacting friction stir welding (FSW) has been proposed. The tool would embody both a prior tooling concept for self-reacting FSW and an auto-adjustable pin-tool (APT) capability developed previously as an augmentation for conventional FSW. Some definitions of terms are prerequisite to a meaningful description of the proposed tool. In conventional FSW, depicted in Figure 1, one uses a tool that includes (1) a rotating shoulder on top (or front) of the workpiece and (2) a rotating pin that protrudes from the shoulder into the depth of the workpiece. The main axial force exerted by the tool on the workpiece is reacted through a ridged backing anvil under (behind) the workpiece. When conventional FSW is augmented with an APT capability, the depth of penetration of the pin into the workpiece is varied in real time by a position- or force-control system that extends or retracts the pin as needed to obtain the desired effect. In self-reacting (also known as self-reacted) friction stir welding (SR-FSW), there are two rotating shoulders: one on top (or front) and one on the bottom (or back) of the workpiece. In this case, a threaded shaft protrudes from the tip of the pin to beyond the back surface of the workpiece. The back shoulder is held axially in place against tension by a nut on the threaded shaft. The main axial force exerted on the workpiece by the tool and front shoulder is reacted through the back shoulder and the threaded shaft, back into the FSW machine head, so that a backing anvil is no longer needed. A key transmits torque between the bottom shoulder and the threaded shaft, so that the bottom shoulder rotates with the shaft. A tool for SRFSW embodying this concept was reported in "Mechanism for Self-Reacted Friction Stir Welding" (MFS-31914), NASA Tech Briefs, Vol. 28, No. 10 (October 2004), page 53. In its outward appearance, the proposed tool (see Figure 2) would fit the above description of an SR

A New Maraging Stainless Steel with Excellent Strength–Toughness–Corrosion Synergy

Directory of Open Access Journals (Sweden)

Jialong Tian

2017-11-01

Full Text Available A new maraging stainless steel with superior strength–toughness–corrosion synergy has been developed based on an innovative concept of alloy design. The high strength–toughness combination is achieved by forming dispersive nano-sized intermetallic compounds in the soft lath martensitic matrix with a slight amount of residual austenite. The good corrosion resistance is guaranteed by exactly controlling the Co content based on understanding the synergistic effect between Co and Cr. The fine structure characteristics of two dominant strengthening precipitations including Ni3Ti and Mo-rich phases were finely characterized associated with transmission electron microscope (TEM and atom probe tomography (APT analyses. The relationship among microstructure, strength and toughness is discussed. The precipitation mechanism of different precipitates in the new maraging stainless steel is revealed based on the APT analysis.

Preliminary Disposal Analysis for Selected Accelerator Production of Tritium Waste Streams

International Nuclear Information System (INIS)

Ades, M.J.; England, J.L.

1998-06-01

A preliminary analysis was performed for two selected Accelerator Production of Tritium (APT) generated mixed and low-level waste streams to determine if one mixed low-level waste (MLLW) stream that includes the Mixed Waste Lead (MWL) can be disposed of at the Nevada Test Site (NTS) and at the Hanford Site and if one low-level radioactive waste (LLW) stream, that includes the Tungsten waste stream (TWS) generated by the Tungsten Neutron Source modules and used in the Target/Blanket cavity vessel, can be disposed of in the LLW Vaults at the Savannah River Plant (SRP). The preliminary disposal analysis that the radionuclide concentrations of the two selected APT waste streams are not in full compliance with the Waste Acceptance Criteria (WAC) and the Performance Assessment (PA) radionuclide limits of the disposal sites considered

A New Maraging Stainless Steel with Excellent Strength-Toughness-Corrosion Synergy.

Science.gov (United States)

Tian, Jialong; Wang, Wei; Babar Shahzad, M; Yan, Wei; Shan, Yiyin; Jiang, Zhouhua; Yang, Ke

2017-11-10

A new maraging stainless steel with superior strength-toughness-corrosion synergy has been developed based on an innovative concept of alloy design. The high strength-toughness combination is achieved by forming dispersive nano-sized intermetallic compounds in the soft lath martensitic matrix with a slight amount of residual austenite. The good corrosion resistance is guaranteed by exactly controlling the Co content based on understanding the synergistic effect between Co and Cr. The fine structure characteristics of two dominant strengthening precipitations including Ni₃Ti and Mo-rich phases were finely characterized associated with transmission electron microscope (TEM) and atom probe tomography (APT) analyses. The relationship among microstructure, strength and toughness is discussed. The precipitation mechanism of different precipitates in the new maraging stainless steel is revealed based on the APT analysis.

An integrated high temperature environmental cell for atom probe tomography studies of gas-surface reactions: Instrumentation and results

International Nuclear Information System (INIS)

Dumpala, S.; Broderick, S.R.; Bagot, P.A.J.; Rajan, K.

2014-01-01

An integrated environmental cell has been designed and developed for the latest generation of Atom Probe Tomography LEAP™ instruments, allowing controlled exposure of samples to gases at high temperatures. Following treatment, samples can be transferred through the LEAP vacuum system for subsequent APT analysis, which provides detailed information on changes to chemical microstructures following the reactions with near-atomic resolution. A full description of the cell is presented, along with some sample results on the oxidation of aluminum and two platinum-group alloys, demonstrating the capability of combining exposure/characterization functionality in a single instrument. - Highlights: • Designed and built atom probe environmental cell for in situ reactions. • Investigated Al oxidation, and demonstrated improvement with new cell. • in situ APT analysis of Pt-alloys showed surface segregation of Rh and Ir

Developing detection efficiency standards for atom probe tomography

Science.gov (United States)

Prosa, Ty J.; Geiser, Brian P.; Lawrence, Dan; Olson, David; Larson, David J.

2014-08-01

Atom Probe Tomography (APT) is a near-atomic-scale analytical technique which, due to recent advances in instrumentation and sample preparation techniques, is being used on a variety of 3D applications. Total system detection efficiency is a key parameter for obtaining accurate spatial reconstruction of atomic coordinates from detected ions, but experimental determination of efficiency can be difficult. This work explores new ways to measure total system detection efficiency as well as the specimen characteristics necessary for such measurements. Composite specimens composed of a nickel/chromium multilayer core, National Institute of Standards and Technology Standard Reference Material 2135c, encapsulated with silver, silicon, or nickel were used to demonstrate the suitability of this approach for providing a direct measurement of APT efficiency. Efficiency measurements based on this multilayer encapsulated in nickel are reported.

Formation of Silver Nanoplates Layer on Amino Group Grafted Silica Coatings

Directory of Open Access Journals (Sweden)

Jurgis PILIPAVICIUS

2016-05-01

Full Text Available In this study the self-arrangement of Ag nanoplates on (3-Aminopropyltriethoxysilane (APTES silanized silica coatings was investigated. Silica coatings were made by sol-gel method and silanized in two different ways. The first one includes silanization in acidic 2-propanol solution, the other one – in dry toluene. Coatings were silanized by using different amounts of APTES in case of silanization in 2-propanol. Silver nanoplates layer of functionalized silica coatings was obtained via self-assembly. Coatings were investigated by atomic force microscopy (AFM, water contact angle measurements (CA, FT-IR analysis, and scanning electron microscopy (SEM. Research showed that dense Ag nanoplates arrangement occurs when there is a high amount of amino groups on the surface.DOI: http://dx.doi.org/10.5755/j01.ms.22.2.8405

An exploratory study of the effects of the dielectric-barrier-discharge surface pre-treatment on the self-assembly processes of a (3-Aminopropyl) trimethoxysilane on glass substrates

International Nuclear Information System (INIS)

Cui Naiyi; Liu Chaozong; Brown, Norman M.D.; Meenan, Brian J.

2007-01-01

X-ray photoelectron spectrometry (XPS), Fourier transform infrared spectrometry (FTIR), secondary-ion-mass spectrometry (SIMS) and contact angle measurement have been used in study of the enhancement effect of substrate pre-treatment by dielectric-barrier-discharge (DBD) for the self-assembly of a (3-Aminopropyl) trimethoxysilane (APTS) on glass substrates. In results, the concentration of the APTS molecules self-assembled on the surfaces of both the acetone-washed and the DBD-treated substrates were more than three times of that on the as-supplied substrate. Meanwhile, the self-assembly (SA) layers grown on the DBD-treated substrates have the best quality compared to those grown on the substrates pre-treated in other ways in terms of the silane-substrate bonding and the order of arrangement of the silane molecules

Untitled

Indian Academy of Sciences (India)

Thus, we should reconsider the items we thought important in the mass production age to aptly cope with the diversification of each customer's requirements, ... processing sequentially (figure 1), where only necessary pieces of information are.

Evaluation Of The Advanced Operating System Of The Ann Arbor Transportation Authority : Driver And Dispatcher Perceptions Of AATA'S Advanced Operating System

Science.gov (United States)

1999-01-01

In 1997, the Ann Arbor (Michigan) Transportation Authority began deploying advanced public transportation systems (APTS) technologies in its fixed route and paratransit operations. The project's concept is the integration of a range of such technolog...

Verification of mechanistic-empirical design models for flexible pavements through accelerated pavement testing.

Science.gov (United States)

2014-08-01

The Midwest States Accelerated Pavement Testing Pooled Fund Program, financed by the highway : departments of Kansas, Iowa, and Missouri, has supported an accelerated pavement testing (APT) project to : validate several models incorporated in the NCH...

Accelerated testing for studying pavement design and performance (FY 2004) : thin bonded rigid overlay on PCCP and HMA (CISL experiment no. 13).

Science.gov (United States)

2009-03-01

The thirteenth full-scale Accelerated Pavement Test (APT) experiment at the Civil Infrastructure Laboratory (CISL) : of Kansas State University aimed to determine the response and the failure mode of thin concrete overlays. Four : pavement structures...

Evaluation Of The Advanced Operating System Of The Ann Arbor Transportation Authority : Transfer And On-Time Performance Study : Before And After AOS Implementation, October 1996 - May 1999

Science.gov (United States)

1999-01-01

In 1997, the Ann Arbor (Michigan) Transportation Authority began deploying advanced public transportation systems (APTS) technologies in its fixed route and paratransit operations. The project's concept is the integration of a range of such technolog...

Ne speshite jego horonit / Stanislav F. Rostotski

Index Scriptorium Estoniae

Rostotski, Stanislav F.

2000-01-01

Bondi-filmide minevikust ja oletatavast tulevikust seoses uue Bondi-filmiga "007 ja liiga kitsas maailm" ("The World Is Not Enough") : režissöör Michael Apted : Peaosas Pierce Brosnan : Suurbritannia - Ameerika Ühendriigid 1999

Evaluation Of The Advanced Operating System Of The Ann Arbor Transportation Authority : Cost Study : Before, During And After AOS Implementation (October 1996-May 1999)

Science.gov (United States)

1999-01-01

In 1997, the Ann Arbor (Michigan) Transportation Authority (AATA) began deploying advanced public transportation systems (APTS) technologies in its fixed route and paratransit operations. The project's concept is the integration of a range of such te...

Accelerated pavement testing of low-volume paved roads with geocell reinforcement : [technical summary].

Science.gov (United States)

2015-03-01

The Midwest States Accelerated Pavement Testing Pooled-Fund Program, financed : by the highway departments of Kansas, Iowa, Missouri, and New York, has : supported an accelerated pavement testing (APT) project to study the rehabilitation : of low-vol...

Accelerated pavement testing of low-volume paved roads with geocell reinforcement.

Science.gov (United States)

2015-03-01

The Midwest States Accelerated Pavement Testing Pooled-Fund Program, financed by the highway : departments of Kansas, Iowa, Missouri, and New York, has supported an accelerated pavement testing (APT) project : to study the rehabilitation of low-volum...

Mobile OS Comparative Study

OpenAIRE

Joseph, Jyothy; K, Shinto Kurian

2013-01-01

In the fast growing mobile revolutionary era, many operating systems are playing vital role in present market. This study is intending to identify the apt and secure mobile based on mobile operating systems capability and user requirements.

Low concentrations of ethanol during irradiation drastically reduce ...

Indian Academy of Sciences (India)

Harinder Singh

2018-02-13

Feb 13, 2018 ... Radiation induced DNA damage depends on factors such as the ..... Apte SK and Haselkorn R 1990 Cloning of salinity stress-induced genes from the ... Elstner EF and Osswald W 1994 Mechanisms of oxygen activation.

Western hypocrisy and the never changing face of financial secrecy jurisdictions: Burying the 1975 UN agenda

OpenAIRE

Young, M.

2017-01-01

In 1975, the characteristics of new and emerging forms of organized crime aptly described those ingredients which in the present day, are directly attributable as enabling criminal money management, in Britain’s Overseas Territories and Crown Dependencies.

Mechanistic-empirical subgrade design model based on heavy vehicle simulator test results

CSIR Research Space (South Africa)

Theyse, HL

2006-06-01

Full Text Available Although Accelerated Pavement Testing (APT) is often done with specific objectives, valuable pavement performance data is generated over the long-term that may be used to investigate pavement behaviour in general and calibrate mechanistic...

Caltrans accelerated pavement testing (CAL/APT) program - test results: 1993-1996

CSIR Research Space (South Africa)

Nokes, WA

1997-08-01

Full Text Available By combining the results of both the HVS and laboratory tests, interpretations of pavement performance are described and recommendations for pavement design and construction have been made to Caltrans....

Roosters, Robins, and Alarm Clocks: Aptness and Conventionality in Metaphor Comprehension

Science.gov (United States)

Jones, Lara L.; Estes, Zachary

2006-01-01

Bowdle and Gentner (2005) proposed a reconciliation of the comparison and categorization models of metaphor comprehension. Their career of metaphor model posits that, as a metaphorical term becomes more conventional, its mode of processing shifts from comparison to categorization. However, other recent studies (Chiappe, Kennedy, & Chiappe, 2003;…

Preconceptual engineering design for the APT 3He Target/Blanket concept

International Nuclear Information System (INIS)

Mensink, D.L.

1994-01-01

A preconceptual engineering design has been developed for the 3 He Target/Blanket (T/B) System for the Accelerator Production of Tritium Project. This concept uses an array of pressure tubes containing tungsten rods for the neutron spallation source and 3 He gas contained in a metal tank and blanket tubes as the tritium production material. The engineering design is based on a physics model optimized for efficient tritium production. Principle engineering consideration were: provisions for cooling all materials including the 3 He gas; containment of the gas and radionuclides; remote handling; material compatibility; minimization of 3 He, D 2 O, and activated waste; modularity; and manufacturability. The design provides a basis for estimating the cost to implement the system

The short-term safety of adjuvant paclitaxel plus trastuzumab - A single centre experience.

Science.gov (United States)

Ates, Ozturk; Sunar, Veli; Aslan, Alma; Karatas, Fatih; Sahin, Suleyman; Altundag, Kadri

2017-01-01

HER2-amplified breast cancer (BC) has a poor prognosis. The combination of trastuzumab with chemotherapy in the adjuvant setting decreases recurrence and improves overall survival in HER2-positive BC. However, the role of adjuvant treatment in patients with HER2-amplified small BC without lymph node involvement is still under debate. The purpose of this study was to investigate the safety of adjuvant paclitaxel and trastuzumab (APT) in this group of patients. A total of 87 operated early BC patients without lymph node involvement (N0) were treated with APT for 12 weeks followed by trastuzumab alone for a total of 9 months. Clinicopathological features and adverse events were analyzed. The median patient age was 50 years (range 28- 82), and 51% of them were postmenopausal. The median tumor diameter was 2.4 cm (range 0.5-6), with 51% of the patients having tumor size between 2 and 3 cm. Eighty-one percent of patients had invasive ductal carcinoma (IDC), and 64% had grade 3 tumors. Adjuvant hormone therapy and adjuvant radiotherapy were administered to 65 and 54% of patients, respectively. At a median follow up of 13 months (range 6-38), one patient (1.1%, 95% CI 0-3.4) experienced an asymptomatic decrease in left ventricular ejection fraction (LVEF) and 3 patients (3.4%, 95% CI 0-6.9) experienced grade 3 neuropathy. APT appears to be a safe combination in early-stage, HER2-amplified and node-negative BC.

Technology benefits resulting from accelerator production of tritium

International Nuclear Information System (INIS)

1998-01-01

One of the early and most dramatic uses of nuclear transformations was in development of the nuclear weapons that brought World War II to an end. Despite that difficult introduction, nuclear weapons technology has been used largely as a deterrent to war throughout the latter half of the twentieth century. The Accelerator Production of Tritium (APT) offers a clean, safe, and reliable means of producing the tritium (a heavy form of hydrogen) needed to maintain the nuclear deterrent. Tritium decays away naturally at a rate of about 5.5% per year; therefore, the tritium reservoirs in nuclear weapons must be periodically replenished. In recent years this has been accomplished by recycling tritium from weapons being retired from the stockpile. Although this strategy has served well since the last US tritium production reactor was shut down in 1988, a new tritium production capability will be required within ten years. Some benefits will result from direct utilization of some of the APT proton beam; others could result from advances in the technologies of particle accelerators and high power spallation targets. The APT may save thousands of lives through the production of medical isotopes, and it may contribute to solving the nation's problem in disposing of long-lived nuclear wastes. But the most significant benefit may come from advancing the technology, so that the great potential of accelerator applications can be realized during our lifetimes

Application of nanoporous silicas as adsorbents for chlorinated aromatic compounds. A comparative study

Energy Technology Data Exchange (ETDEWEB)

Moritz, Michał, E-mail: michal.moritz@put.poznan.pl [Poznan University of Technology, Faculty of Chemical Technology, Institute of Chemistry and Technical Electrochemistry, Piotrowo 3, 60-965 Poznań (Poland); Adam Mickiewicz University, Faculty of Chemistry, Umultowska 89b, 61-614 Poznań (Poland); Geszke-Moritz, Małgorzata, E-mail: Malgorzata.Geszke-Moritz@amu.edu.pl [NanoBioMedical Centre, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland)

2014-08-01

The removal of two selected environmental pollutants such as 2,4-dichlorophenoxyacetic acid (2,4-D) and Triclosan (TC) was examined by adsorption experiments on the modified SBA-15 and MCF mesoporous silicas. Mesoporous adsorbents were modified by a grafting process with (3-aminopropyl)triethoxysilane (APTES) and 1-[3-(trimethoxysilyl)propyl]urea (TMSPU). Mesoporous materials were synthesized and characterized by N{sub 2} adsorption–desorption experiment, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), elemental analysis and adsorption studies. The results show that both APTES-functionalized SBA-15 and MCF nanoporous carriers are potentially good adsorbents for the removal of 2,4-D in a wide range of concentrations from 0.1 to 4 mg/cm{sup 3}. Maximum adsorption capacity of as-modified adsorbents for 2,4-D estimated from the Langmuir model was ∼ 280 mg/g. The ionic interaction between the adsorbent and 2,4-D seems to play a key role in the adsorption process of the pollutant on APTES-modified siliceous matrices. The efficiency of TC sorption onto all prepared mesoporous adsorbents was significantly lower as compared to the entrapment of 2,4-D. Experimental data were best fitted by the Langmuir isotherm model. The results of this study suggest that mesoporous silica-based materials are promising adsorbents for the removal of selected organic pollutants. - Graphical abstract: Adsorption of 2,4-dichlorophenoxyacetic acid and Triclosan inside 3-amino-functionalized mesoporous channel.

Design and fabrication of an aptasensor for chloramphenicol based on energy transfer of CdTe quantum dots to graphene oxide sheet.

Science.gov (United States)

Alibolandi, Mona; Hadizadeh, Farzin; Vajhedin, Fereshteh; Abnous, Khalil; Ramezani, Mohammad

2015-03-01

Detection and quantification of chloramphenicol have played essential roles in the effort to minimize food safety risk. Herein, a sophisticated "turn on" aptasensor based on aptamer-CdTe quantum dots (Apt-QDs) and graphene oxide (GO) was developed for chloramphenicol sensing. In this assay, the fluorescence of CdTe QDs-Apt was efficiently quenched through energy transfer from QDs-Apt to GO, and chloramphenicol was detected by recovering the quenched fluorescence due to specific binding between aptamer and chloramphenicol. The results indicated that the addition of a CdTe QDs-labeled aptamer to a GO solution (250μg/mL) led to a high quenching efficiency, yielding over 90% fluorescence quenching. Using a series of chloramphenicol concentrations (0.1 to 10nM) aptasensor provides a limit of detection and limit of quantification at 98pM and 987pM, respectively. Linearity of response over chloramphenicol was demonstrated (r>0.99). Furthermore, the GO-based aptasensor exhibited excellent selectivity toward chloramphenicol compared to other synthetic drugs with similar structures such as thiamphenicol, metronidazole and nitrofurantoin. Good reproducibility and precision (RSD 4.73%, n=10) of the assay indicates the ability of the aptasensor for routine quantitative trace analysis of chloramphenicol. Our results suggested that the prepared aptasensor was also well qualified for the detection of chloramphenicol in milk with a limit of detection of 0.2ppb. Copyright © 2014 Elsevier B.V. All rights reserved.

Supercritical carbon dioxide versus toluene as reaction media in silica functionalisation: Synthesis and characterisation of bonded aminopropyl silica intermediate.

Science.gov (United States)

Ashu-Arrah, Benjamin A; Glennon, Jeremy D

2017-06-09

This research reports supercritical carbon dioxide versus toluene as reaction media in silica functionalisation for use in liquid chromatography. Bonded aminopropyl silica (APS) intermediates were prepared when porous silica particles (Exsil-pure, 3μm) were reacted with 3-aminopropyltriethoxysilane (3-APTES) or N,N-dimethylaminopropyltrimethoxysilane (DMAPTMS) using supercritical carbon dioxide (sc-CO 2 ) and toluene as reaction media. Covalent bonding to silica was confirmed using elemental microanalysis (CHN), thermogravimetric analysis (TGA), zeta potential (ξ), diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, scanning electron microscopy (SEM) and solid-state nuclear magnetic resonance (CP/MAS NMR) spectroscopy. The results demonstrate that under sc-CO 2 conditions of 100°C/414bar in a substantial reduced time of 3h, the surface coverage of APS (evaluated from%C obtained from elemental analysis) prepared with APTES (%C: 8.03, 5.26μmol/m -2 ) or DMAPTES (%C: 5.12, 4.58μmol/m 2 ) is somewhat higher when compared to organic based reactions under reflux in toluene at a temperature of 110°C in 24h with APTES (%C: 7.33, 4.71μmol/m 2 ) and DMAPTMS (%C: 4.93, 4.38μmol/m 2 ). Zeta potential measurements revealed a change in electrostatic surface charge from negative values for bare Exsil-pure silica to positive for functionalised APS materials indicating successful immobilization of the aminosilane onto the surface of silica. Copyright © 2017 Elsevier B.V. All rights reserved.

Novel MUC1 aptamer selectively delivers cytotoxic agent to cancer cells in vitro.

Directory of Open Access Journals (Sweden)

Yan Hu

Full Text Available Chemotherapy is a primary treatment for cancer, but its efficacy is often limited by the adverse effects of cytotoxic agents. Targeted drug delivery may reduce the non-specific toxicity of chemotherapy by selectively directing anticancer drugs to tumor cells. MUC1 protein is an attractive target for tumor-specific drug delivery owning to its overexpression in most adenocarcinomas. In this study, a novel MUC1 aptamer is exploited as the targeting ligand for carrying doxorubicin (Dox to cancer cells. We developed an 86-base DNA aptamer (MA3 that bound to a peptide epitope of MUC1 with a K(d of 38.3 nM and minimal cross reactivity to albumin. Using A549 lung cancer and MCF-7 breast cancer cells as MUC1-expressing models, MA3 was found to preferentially bind to MUC1-positive but not MUC1-negative cells. An aptamer-doxorubicin complex (Apt-Dox was formulated by intercalating doxorubicin into the DNA structure of MA3. Apt-Dox was found capable of carrying doxorubicin into MUC1-positive tumor cells, while significantly reducing the drug intake by MUC1-negative cells. Moreover, Apt-Dox retained the efficacy of doxorubicin against MUC1-positive tumor cells, but lowered the toxicity to MUC1-negative cells (P<0.01. The results suggest that the MUC1 aptamer may have potential utility as a targeting ligand for selective delivery of cytotoxic agent to MUC1-expressing tumors.

Accelerator production of tritium authorization basis strategy

International Nuclear Information System (INIS)

Miller, L.A.; Edwards, J.; Rose, S.

1996-01-01

The Accelerator Production of Tritium (APT) project has proposed a strategy to develop the APT authorization basis and safety case based on DOE orders and fundamental requirements for safe operation. The strategy is viable regardless of whether the APT is regulated by DOE or by an external regulatory body. Currently the operation of Department of Energy (DOE) facilities is authorized by DOE and regulated by DOE orders and regulations while meeting the environmental protection requirements of the Environmental Protection Agency (EPA) and the states. In the spring of 1994, Congress proposed legislation and held hearings related to requiring all DOE operations to be subject to external regulation. On January 25, 1995, DOE, with the support of the White House Council on Environmental Quality, created the Advisory Committee on External Regulation of Department of Energy Nuclear Safety. This committee divided its recommendations into three areas: (1) facility safety, (2) worker safety, and (3) environmental protection. In the area of facility safety the committee recommended external regulation of DOE nuclear facilities by either the Nuclear Regulatory Commission (NRC) or a restructured Defense Nuclear Facilities Safety Board (DNFSB). In the area of worker safety, the committee recommended that the Occupational Safety and Health Administration (OSHA) regulate DOE nuclear facilities. In the environmental protection area, the committee did not recommend a change in the regulation by the EPA and the states of DOE nuclear facilities. If these recommendations are accepted, all DOE nuclear facilities will be impacted to some extent

Quantification of nanowire uptake by live cells

KAUST Repository

Margineanu, Michael B.

2015-01-01

attempts have been made at tagging and investigating their interaction with living cells. In this study, magnetic iron nanowires with an iron oxide layer are coated with (3-Aminopropyl)triethoxysilane (APTES), and subsequently labeled with a fluorogenic p

Top-down cracking of rigid pavements constructed with fast setting hydraulic cement concrete

CSIR Research Space (South Africa)

Heath, AC

2009-01-29

Full Text Available Jointed plain concrete pavement (JPCP) test sections were constructed using fast setting hydrualic cement concrete (FSHCC) as part of the California accelerated pavement testing program (CAL/APT). Many of the longer slabs cracked under environmental...

Overview of renewable energy sources development in France

International Nuclear Information System (INIS)

Lengyel, J.; Lepy, S.; Roudergues, J.M.

2009-01-01

Generation from Renewable Energy Sources is booming. As for any conventional generation technology, RES specific technical features can be accommodated by the electric system with no tremendous difficulty, provided the grid can be aptly adapted and developed. (authors)

Models for the numerical simulation of radionuclide migration in underground storage of radioactive waste. Final report

International Nuclear Information System (INIS)

Petschel, M.; Heidenreich, H.; Beger, E.; Schneider, H.

1992-03-01

The report contains validation works - implementation, assurance of function, further development of numerical models (where applicable), program and application documentation, data acquisition - for the programs and program systems BIDERA, GEOFIM, GISTZ, KASOMO, APT6 and MARE. (HP) [de

Homelessness in the U.S.: How Home Economists Can Help.

Science.gov (United States)

Berger, Peggy; And Others

1989-01-01

The problem of unavailable, unaffordable housing in the United States is apt to worsen. Three articles examine the factors that are associated with homelessness and discuss the role of home economists as it relates to possible solutions. (JOW)

L’esercizio e gli Essais. La retorica filosofica di Montaigne

Directory of Open Access Journals (Sweden)

Emanuele Ronchetti

2012-06-01

Full Text Available The Essais’s writing generates a form of original pyrrhonian philosophical discourse, apt to express the infinite variety of the world. In this way it paves the way to a limitless method of investigation: zetetics.

Evolutionarily conserved transcription factor Apontic controls the G1/S progression by inducing cyclin e during eye development

KAUST Repository

Liu, Qingxin

2014-06-16

During Drosophila eye development, differentiation initiates in the posterior region of the eye disk and progresses anteriorly as a wave marked by the morphogenetic furrow (MF), which demarcates the boundary between anterior undifferentiated cells and posterior differentiated photoreceptors. However, the mechanism underlying the regulation of gene expression immediately before the onset of differentiation remains unclear. Here, we show that Apontic (Apt), which is an evolutionarily conserved transcription factor, is expressed in the differentiating cells posterior to the MF. Moreover, it directly induces the expression of cyclin E and is also required for the G1-to-S phase transition, which is known to be essential for the initiation of cell differentiation at the MF. These observations identify a pathway crucial for eye development, governed by a mechanism in which Cyclin E promotes the G1-to-S phase transition when regulated by Apt.

Perturbation theory for water with an associating reference fluid

Science.gov (United States)

Marshall, Bennett D.

2017-11-01

The theoretical description of the thermodynamics of water is challenged by the structural transition towards tetrahedral symmetry at ambient conditions. As perturbation theories typically assume a spherically symmetric reference fluid, they are incapable of accurately describing the liquid properties of water at ambient conditions. In this paper we address this problem by introducing the concept of an associated reference perturbation theory (APT). In APT we treat the reference fluid as an associating hard sphere fluid which transitions to tetrahedral symmetry in the fully hydrogen bonded limit. We calculate this transition in a theoretically self-consistent manner without appealing to molecular simulations. This associated reference provides the reference fluid for a second order Barker-Henderson perturbative treatment of the long-range attractions. We demonstrate that this approach gives a significantly improved description of water as compared to standard perturbation theories.

Evolutionarily conserved transcription factor Apontic controls the G1/S progression by inducing cyclin e during eye development

KAUST Repository

Liu, Qingxin; Wang, Xianfeng; Ikeo, Kazuho; Hirose, Susumu; Gehring, Walter Jakob; Gojobori, Takashi

2014-01-01

During Drosophila eye development, differentiation initiates in the posterior region of the eye disk and progresses anteriorly as a wave marked by the morphogenetic furrow (MF), which demarcates the boundary between anterior undifferentiated cells and posterior differentiated photoreceptors. However, the mechanism underlying the regulation of gene expression immediately before the onset of differentiation remains unclear. Here, we show that Apontic (Apt), which is an evolutionarily conserved transcription factor, is expressed in the differentiating cells posterior to the MF. Moreover, it directly induces the expression of cyclin E and is also required for the G1-to-S phase transition, which is known to be essential for the initiation of cell differentiation at the MF. These observations identify a pathway crucial for eye development, governed by a mechanism in which Cyclin E promotes the G1-to-S phase transition when regulated by Apt.

Organosilane functionalization of halloysite nanotubes for enhanced loading and controlled release

International Nuclear Information System (INIS)

Yuan Peng; Southon, Peter D; Kepert, Cameron J; Liu Zongwen

2012-01-01

The surfaces of naturally occurring halloysite nanotubes were functionalized with γ-aminopropyltriethoxysilane (APTES), which was found to have a substantial effect on the loading and subsequent release of a model dye molecule. APTES was mostly anchored at the internal lumen surface of halloysite through covalent grafting, forming a functionalized surface covered by aminopropyl groups. The dye loading of the functionalized halloysite was 32% greater than that of the unmodified sample, and the release from the functionalized halloysite was dramatically prolonged as compared to that from the unmodified one. Dye release was prolonged at low pH and the release at pH 3.5 was approximately three times slower than that at pH 10.0. These results demonstrate that organosilane functionalization makes pH an external trigger for controlling the loading of guest on halloysite and the subsequent controlled release. (paper)

Organosilane functionalization of halloysite nanotubes for enhanced loading and controlled release.

Science.gov (United States)

Yuan, Peng; Southon, Peter D; Liu, Zongwen; Kepert, Cameron J

2012-09-21

The surfaces of naturally occurring halloysite nanotubes were functionalized with γ-aminopropyltriethoxysilane (APTES), which was found to have a substantial effect on the loading and subsequent release of a model dye molecule. APTES was mostly anchored at the internal lumen surface of halloysite through covalent grafting, forming a functionalized surface covered by aminopropyl groups. The dye loading of the functionalized halloysite was 32% greater than that of the unmodified sample, and the release from the functionalized halloysite was dramatically prolonged as compared to that from the unmodified one. Dye release was prolonged at low pH and the release at pH 3.5 was approximately three times slower than that at pH 10.0. These results demonstrate that organosilane functionalization makes pH an external trigger for controlling the loading of guest on halloysite and the subsequent controlled release.

Synthesis, characterization and theoretical studies of 5-(benzylthio)-1-cylopentyl-1H-tetrazole

Science.gov (United States)

Saglam, S.; Disli, A.; Erdogdu, Y.; Marchewka, M. K.; Kanagathara, N.; Bay, B.; Güllüoğlu, M. T.

2015-01-01

In this study, 5-(benzylthio)-1-cylopentyl-1H-tetrazole (5B1C1HT) have been synthesized. Boiling points of the obtained compound have been determined and it has been characterized by FT-IR, 1H NMR, 13C-APT and LC-MS spectroscopy techniques. The FT-IR, 1H NMR and 13C-APT spectral measurements of the 5B1C1HT compound and complete assignment of the vibrational bands observed in spectra has been discussed. The spectra were interpreted with the aid of normal coordinate analysis following full structure optimization and force field calculations based on Density Functional Theory (DFT) at 6-311++G**, cc-pVDZ and cc-pVTZ basis sets. The optimized geometry with 6-311++G** basis sets were used to determine the total energy distribution, harmonic vibrational frequencies, IR intensities.

Specific and selective target detection of supra-genome 21 Mers Salmonella via silicon nanowires biosensor

Science.gov (United States)

Mustafa, Mohammad Razif Bin; Dhahi, Th S.; Ehfaed, Nuri. A. K. H.; Adam, Tijjani; Hashim, U.; Azizah, N.; Mohammed, Mohammed; Noriman, N. Z.

2017-09-01

The nano structure based on silicon can be surface modified to be used as label-free biosensors that allow real-time measurements. The silicon nanowire surface was functionalized using 3-aminopropyltrimethoxysilane (APTES), which functions as a facilitator to immobilize biomolecules on the silicon nanowire surface. The process is simple, economical; this will pave the way for point-of-care applications. However, the surface modification and subsequent detection mechanism still not clear. Thus, study proposed step by step process of silicon nano surface modification and its possible in specific and selective target detection of Supra-genome 21 Mers Salmonella. The device captured the molecule with precisely; the approach took the advantages of strong binding chemistry created between APTES and biomolecule. The results indicated how modifications of the nanowires provide sensing capability with strong surface chemistries that can lead to specific and selective target detection.

Interpretation of atom probe tomography data for the intermetallic TiAl+Nb by means of field evaporation simulation

KAUST Repository

Boll, Torben; Al-Kassab, Talaat

2013-01-01

In this paper simulations of the field evaporation process during field ion microscopy (FIM) and atom probe tomography (APT) are presented and compared with experimental data. The Müller-Schottky-model [1] was extended to include the local atomic

The influence of elastic strain on the early stages of decomposition in Cu–1.7at% Fe

KAUST Repository

Rademacher, Thomas; Al-Kassab, Talaat; Kirchheim, Reiner

2009-01-01

with FIM images, alignments of precipitates mainly in < 100 > directions were found. Besides, a general experimental concept to evaluate strain-related effects on the position of the proximate precipitate will be introduced. These analyses of the APT and c

Dance for children: a functional education for national growth | Suru ...

African Journals Online (AJOL)

Dance for children: a functional education for national growth. ... This statement of fact was discovered and aptly applied by the traditional societies of ... not just by the modern and acculturated child but, by parents and the government as well.

Mild Developmental Hypothyroidism and Trace Fear Conditioning: Role of Gender and Shock Duration.

Science.gov (United States)

Rodent models of developmental thyroid hormone (TH) deficiency aptly reflect the deleterious effects of severe TH deficiencies on brain structure and function in humans. However, the impact of moderate TH insufficiencies on neurodevelopmental outcomes has proven more difficult to...

Patterns of referral to Red Cross War Memorial Children's Hospital ...

African Journals Online (AJOL)

Memorial Children's Hospital, K1ipfontein Road, Rondebosch, 7700 RSA,. Accepted 10 Apt 1990, ... of every patient referred in the study period, or recorded the folder number of ..... Council for providing a short-term grant; Mariah Jacobs of the.

Damn the Permanganate Volcanoes: Full Principles Ahead.

Science.gov (United States)

Pilar, Frank L.

1981-01-01

Discusses whether chemistry should be taught using a purely descriptive approach or using the current "principles" approach. Considers what sort of background should be provided given the uses students are most apt to make of their general chemistry training. (SK)

Optimization of 7-T Chemical Exchange Saturation Transfer Parameters for Validation of Glycosaminoglycan and Amide Proton Transfer of Fibroglandular Breast Tissue

NARCIS (Netherlands)

Dula, Adrienne N.; Dewey, Blake E.; Arlinghaus, Lori R.; Williams, Jason M.; Klomp, DWJ; Yankeelov, Thomas E.; Smith, Seth

Purpose: To (a) implement simulation-optimized chemical exchange saturation transfer (CEST) measurements sensitive to amide proton transfer (APT) and glycosaminoglycan (GAG) hydroxyl proton transfer effects in the human breast at 7 T and (b) determine the reliability of these techniques for

Capillary electrophoresis fingerprinting, quantification and mass-identification of various 9-aminopyrene-1,4,6-trisulfonate-derivatized oligomers derived from plant polysaccharides

NARCIS (Netherlands)

Kabel, M.A.; Heijnis, W.H.; Bakx, E.J.; Kuijpers, I.J.; Voragen, A.G.J.; Schols, H.A.

2006-01-01

Various plant polysaccharide derived mono- and oligosaccharides were derivatized with the fluorescent 9-aminopyrene-1,4,6-trisulfonate (APTS) and subjected to capillary electrophoresis (CE) in combination with laser induced fluorescence (LIF) detection. CE-LIF was suitable for mol-based

Permanent deformation and in-depth deflection records for selected HVS tests

CSIR Research Space (South Africa)

Theyse, HL

1999-03-01

Full Text Available Transportek has been involved in accelerated pavement testing (APT) with a fleet of Heavy Vehicle Simulators (HVSs) over the past two decades. During this period, a vast amount of pavement response and performance data has been accumulated...

Atom-probe tomography the local electrode atom probe

CERN Document Server

Miller, Michael K

2014-01-01

In this comprehensive introduction to the use of APT in nanocharacterization, readers will find everything they need to get up to speed on the technique, from the core physics to state-of-the-art instrumentation and revised methods of data analysis.

Ila, Prof. Hiriyakkanavar

Indian Academy of Sciences (India)

Elected: 1991 Section: Chemistry. Ila, Prof. Hiriyakkanavar Ph.D. (IIT, Kanpur), FNA. Date of birth: 11 September 1944. Specialization: Synthetic Organic Chemistry, Heterocyclic Chemistry, Medicinal Chemistry Address: Apt. 002, Block VIII, Heritage Estate, Doddaballapur Road, Yelahanka, Bengaluru 560 064, Karnataka

Dialectical Discursive Storytelling in Organizational Transformations

DEFF Research Database (Denmark)

Bager, Ann Starbæk; Svane, Marita Susanna

by organizational storytelling practices but also as active re-constituents through experience, (self-)reflexivity, and sensemaking. The paper suggests further research of the potential of dialectical discursive storytelling as a performative research practice apt for or-ganizational cultural transformation through...

Studying place practices and consumption through volunteer-employed photography

DEFF Research Database (Denmark)

Pristed Nielsen, Helene; Møller, Karina Torp

2016-01-01

upon such choices. Additionally, we argue that the employed data collection techniques, involving a combination of volunteer-employed photography with participants’ comments on their own photos and information about their socio-demographic profile, constitute a particularly apt approach for shedding...

A magnetic nanoparticle-clustering biosensor for blu-ray based optical detection of small-molecules

DEFF Research Database (Denmark)

Yang, Jaeyoung; Donolato, Marco; Antunes, Paula Soares Martins

2014-01-01

MNP-clustering facilitates high-resolution small-molecule assays. For experiments, aptamer-functionalized MNPs (Apt-MNPs) were first incubated with adenosine-5'-triphosphate (ATP) followed by adding MNPs with linker strands (linker-MNPs). The linker hybridizes with a region of aptamer sequences...

Deposition kinetics of nanocolloidal gold particles

NARCIS (Netherlands)

Brouwer, E.A.M.; Kooij, Ernst S.; Hakbijl, Mark; Wormeester, Herbert; Poelsema, Bene

2005-01-01

The deposition kinetics of the irreversible adsorption of citrate-stabilized, nanocolloidal gold particles on Si/SiO2 surfaces, derivatized with (aminopropyl)triethoxysilane (APTES), is investigated in situ using single wavelength optical reflectometry. A well-defined flow of colloids towards the

Research for Development in the Dry Arab Region The Cactus Flower

International Development Research Centre (IDRC) Digital Library (Canada)

Drylands are aptly named for the lack of water, the basis of life. ...... These fields are more fertile as they receive run-off water and sediments from their ...... sector in particular on site rehabilitation as well as waste and water management.

HIERARCHY OF TRUTHS REVISITED

African Journals Online (AJOL)

to understand better what unites and divides Christians in matters of doctrine; why this notion is ..... signs of bread and wine and the connection between them and that which is ... an apt appreciation of certain aspects of a revealed mystery,.

Surface bioengineering of diatomite based nanovectors for efficient intracellular uptake and drug delivery

Science.gov (United States)

Terracciano, Monica; Shahbazi, Mohammad-Ali; Correia, Alexandra; Rea, Ilaria; Lamberti, Annalisa; de Stefano, Luca; Santos, Hélder A.

2015-11-01

Diatomite is a natural porous silica material of sedimentary origin. Due to its peculiar properties, it can be considered as a valid surrogate of synthetic porous silica for nano-based drug delivery. In this work, we exploit the potential of diatomite nanoparticles (DNPs) for drug delivery with the aim of developing a successful dual-biofunctionalization method by polyethylene glycol (PEG) coverage and cell-penetrating peptide (CPP) bioconjugation, to improve the physicochemical and biological properties of the particles, to enhance the intracellular uptake in cancer cells, and to increase the biocompatibility of 3-aminopropyltriethoxysilane (APT) modified-DNPs. DNPs-APT-PEG-CPP showed hemocompatibility for up to 200 μg mL-1 after 48 h of incubation with erythrocytes, with a hemolysis value of only 1.3%. The cytotoxicity of the modified-DNPs with a concentration up to 200 μg mL-1 and incubation with MCF-7 and MDA-MB-231 breast cancer cells for 24 h, demonstrated that PEGylation and CPP-bioconjugation can strongly reduce the cytotoxicity of DNPs-APT. The cellular uptake of the modified-DNPs was also evaluated using the above mentioned cancer cell lines, showing that the CPP-bioconjugation can considerably increase the DNP cellular uptake. Moreover, the dual surface modification of DNPs improved both the loading of a poorly water-soluble anticancer drug, sorafenib, with a loading degree up to 22 wt%, and also enhanced the drug release profiles in aqueous solutions. Overall, this work demonstrates that the biofunctionalization of DNPs is a promising platform for drug delivery applications in cancer therapy as a result of its enhanced stability, biocompatibility, cellular uptake, and drug release profiles.Diatomite is a natural porous silica material of sedimentary origin. Due to its peculiar properties, it can be considered as a valid surrogate of synthetic porous silica for nano-based drug delivery. In this work, we exploit the potential of diatomite nanoparticles

Synthesis and characterization of lanthanide-based luminescent nanoparticles: toward new bio-labels

International Nuclear Information System (INIS)

Lechevallier, Severine

2010-01-01

This work deals with the development of luminescent nanoparticles (NPs) suitable as bio-labels. Inorganic NPs have been synthesized, in which luminescent ion (Eu 3+ in most of cases) is substituting ions of the oxide host matrix. NPs of Ln(OH)CO 3 :Eu 3+ (Ln = Y or Gd), Ln 2 O 3 :Eu 3+ , Ln 2 O 2 S:Eu 3+ and SiO 2 :Eu 3+ have been characterized by the way of TGA, WAXS-XRD, TEM, IR and photoluminescence (PL) techniques. The controlled precipitation using urea as precipitating agent is the way chosen and optimized to obtain spherical and monodispersed in size (150±15 nm) NPs. These particles of amorphous lanthanide hydroxycarbonate can directly be used as luminescent bio-labels or after their conversion in oxide or oxi-sulfide. For the silica particles, the synthesis by aerosol pyrolysis has been used. The obtained particles are spherical with a main diameter of 350 nm. In a second step, the surface of the inorganic NPs has been modified, in order to graft amino-reactive functions. Several modification ways have been explored: with APTES (aminopropyltriethoxysilane), with TEOS (tetra-ethoxysilane) and then APTES, or with a TEOS/APTES mixture. The same characterizations techniques have been applied to the modified particles, and chemical analysis, solid state NMR and XPS. DLS and ζ-potential of the NPs dispersed in water have also been measured. These analyses have been completed by the evaluation of the number of accessible amine functions by coupling with FITC (fluorescein isothiocyanate). The direct modification of oxides (Y 2 O 3 or Gd 2 O 3 ) with APTES is the best way, and an homogenous layer of 1 nm with a high number of accessible amine can be graft. Finally, to move toward luminescent bio-labelling in biological medium, the luminescence of the NPs has been observed and analyzed using: - A spectro-fluorimeter, after their dispersion in water; - A fluorescence microscope, on glass slides, under broad band excitation; - A confocal microscope, under laser

EpCAM aptamer-functionalized polydopamine-coated mesoporous silica nanoparticles loaded with DM1 for targeted therapy in colorectal cancer

Directory of Open Access Journals (Sweden)

Li Y

2017-08-01

Full Text Available Yang Li,1,* Yanhong Duo,2,3,* Shiyun Bao,1 Lisheng He,4 Kai Ling,5 Jinfeng Luo,4 Yue Zhang,1 Hao Huang,2 Han Zhang,2 Xiaofang Yu1 1Department of Hepatobiliary and Pancreas Surgery, Second Clinical Medical College of Jinan University, Shenzhen People’s Hospital, 2Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, Collaborative Innovation Center for Optoelectronic Science and Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, 3Key Laboratory of Plant Cell Activities and Stress Adaptation, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 4Department of Pathology, 5Institute of Respiratory Diseases, Second Clinical Medical College of Jinan University, Shenzhen People’s Hospital, Shenzhen, China *These authors contributed equally to this work Abstract: DM1, a maytansine derivative, is a highly potential cytotoxic agent but with severe side effects; therefore, its application in clinical cancer therapy is limited. Here, in order to mitigate this intrinsic drawback of DM1, we developed mesoporous silica nanoparticles (MSNs loaded with DM1 and surface-decorated with hydrochloride dopamine (PDA, polyethylene glycol (PEG, and epithelial cell adhesion molecule (EpCAM aptamer (APt for the targeted treatment of colorectal cancer (CRC. In this system, the PDA coating could be used as pH-sensitive gatekeepers to control the release of DM1 from MSNs in response to the pH stimulus and EpCAM APt-guided active targeting enables the increased delivery of DM1 to CRC as well as a reduction in toxicity and side effects by minimizing the exposure of normal tissues to DM1. Results demonstrated that DM1 inhibited the formation of microtubules and induced apoptosis in tumor cells via caspase signaling. In comparison with the control groups, the MSNs-DM1@PDA-PEG-APt bioconjugates exhibited

Determination of NH_2 concentration on 3-aminopropyl tri-ethoxy silane layers and cyclopropylamine plasma polymers by liquid-phase derivatization with 5-iodo 2-furaldehyde

International Nuclear Information System (INIS)

Manakhov, Anton; Čechal, Jan; Michlíček, Miroslav; Shtansky, Dmitry V.

2017-01-01

Highlights: • A new method for primary amines derivatization is proposed and validated. • The chemical structure of APTES layer is studied. • The derivatization by 5-iodo 2-furaldehyde allowed to avoid side reactions in contrast to 4-trifluoromethyl benzaldehyde derivatization. - Abstract: The quantification of concentration of primary amines, e.g. in plasma polymerized layers is a very important task for surface analysis. However, the commonly used procedure, such as gas phase derivatization with benzaldehydes, shows several drawbacks, the most important of which are the side reaction effects. In the present study we propose and validate a liquid phase derivatization using 5-iodo 2-furaldehyde (IFA). It was demonstrated that the content of NH_2 groups can be determined from the atomic concentrations measured by X-ray photoelectron spectroscopy (XPS), in particular from the ratio of I 3d and N 1s peak intensities. First, we demonstrate the method on a prototypical system such as 3-aminopropyl tri-ethoxy silane (APTES) layer. Here the XPS analysis carried out after reaction of APTES layer with IFA gives the fraction of primary amines (NH_2/N) of 38.3 ± 7.9%. Comparing this value with that obtained by N 1s curve fitting of APTES layer giving 40.9 ± 9.5% of amine groups, it can be concluded that all primary amines were derivatized by reaction with IFA. The second system to demonstrate the method comprises cyclopropylamine (CPA) plasma polymers that were free from conjugated imines. In this case the method gives the NH_2 fraction ∼8.5%. This value is closely matching the NH_2/N ratio estimated by 4-trifluoromethyl benzaldehyde (TFBA) derivatization. The reaction of IFA with CPA plasma polymer exhibiting high density of conjugated imines revealed the NH_2/N fraction of ∼10.8%. This value was significantly lower compared to 17.3% estimated by TFBA derivatization. As the overestimated density of primary amines measured by TFBA derivatization is probably

Determination of NH{sub 2} concentration on 3-aminopropyl tri-ethoxy silane layers and cyclopropylamine plasma polymers by liquid-phase derivatization with 5-iodo 2-furaldehyde

Energy Technology Data Exchange (ETDEWEB)

Manakhov, Anton, E-mail: ant-manahov@ya.ru [National University of Science and Technology “MISiS”, Leninsky pr. 4, Moscow 119049 (Russian Federation); RG Plasma Technologies, CEITEC—Central European Institute of Technology, Masaryk University, Kotlářská, 2, 61137 Brno (Czech Republic); Čechal, Jan [CEITEC—Central European Institute of Technology, Brno University of Technology, Purkyňova 123, 612 00 Brno (Czech Republic); Institute of Physical Engineering, Brno University of Technology, Technická 2896/2, 616 69 Brno (Czech Republic); Michlíček, Miroslav [RG Plasma Technologies, CEITEC—Central European Institute of Technology, Masaryk University, Kotlářská, 2, 61137 Brno (Czech Republic); Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářská 2, 61137 Brno (Czech Republic); Shtansky, Dmitry V. [National University of Science and Technology “MISiS”, Leninsky pr. 4, Moscow 119049 (Russian Federation)

2017-08-31

Highlights: • A new method for primary amines derivatization is proposed and validated. • The chemical structure of APTES layer is studied. • The derivatization by 5-iodo 2-furaldehyde allowed to avoid side reactions in contrast to 4-trifluoromethyl benzaldehyde derivatization. - Abstract: The quantification of concentration of primary amines, e.g. in plasma polymerized layers is a very important task for surface analysis. However, the commonly used procedure, such as gas phase derivatization with benzaldehydes, shows several drawbacks, the most important of which are the side reaction effects. In the present study we propose and validate a liquid phase derivatization using 5-iodo 2-furaldehyde (IFA). It was demonstrated that the content of NH{sub 2} groups can be determined from the atomic concentrations measured by X-ray photoelectron spectroscopy (XPS), in particular from the ratio of I 3d and N 1s peak intensities. First, we demonstrate the method on a prototypical system such as 3-aminopropyl tri-ethoxy silane (APTES) layer. Here the XPS analysis carried out after reaction of APTES layer with IFA gives the fraction of primary amines (NH{sub 2}/N) of 38.3 ± 7.9%. Comparing this value with that obtained by N 1s curve fitting of APTES layer giving 40.9 ± 9.5% of amine groups, it can be concluded that all primary amines were derivatized by reaction with IFA. The second system to demonstrate the method comprises cyclopropylamine (CPA) plasma polymers that were free from conjugated imines. In this case the method gives the NH{sub 2} fraction ∼8.5%. This value is closely matching the NH{sub 2}/N ratio estimated by 4-trifluoromethyl benzaldehyde (TFBA) derivatization. The reaction of IFA with CPA plasma polymer exhibiting high density of conjugated imines revealed the NH{sub 2}/N fraction of ∼10.8%. This value was significantly lower compared to 17.3% estimated by TFBA derivatization. As the overestimated density of primary amines measured by TFBA

Arthropod pattern theory and Cambrian trilobites

NARCIS (Netherlands)

Sundberg, Frederick A.

1995-01-01

An analysis of duplomere (= segment) distribution within the cephalon, thorax, and pygidium of Cambrian trilobites was undertaken to determine if the Arthropod Pattern Theory (APT) proposed by Schram & Emerson (1991) applies to Cambrian trilobites. The boundary of the cephalon/thorax occurs within

The mosaic film: nomadic style and politics in transnational media culture

NARCIS (Netherlands)

Pisters, P.; Bal, M.; Hernandez-Navarro, M.Á.

2011-01-01

In contemporary media culture the formal, narrative, and stylistic structures that are most pervasive can be described as an aesthetics of the mosaic. Multiple main characters, multiple interwoven story-lines, multiple or fragmented spaces, different timezones or paces seem to be specifically apt

Fuels and chemicals from equine-waste-derived tail gas reactive pyrolysis oil: technoeconomic analysis, environmental and exergetic life cycle assessment

Science.gov (United States)

Horse manure, whose improper disposal imposes considerable environmental costs, constitutes an apt feedstock for conversion to renewable fuels and chemicals when tail gas reactive pyrolysis (TGRP) is employed. TGRP is a modification of fast pyrolysis that recycles its non-condensable gases and produ...

Performances of the HL (Hyperloop) transport system

NARCIS (Netherlands)

van Goeverden, C.D.; Milakis, D.; Janic, M.; Konings, J.W.; Cools, M.; Limbourg, S.

2017-01-01

This paper deals with an analysis of performances of the HL (Hyperloop) transport system considered as an advanced transport alternative to the existing APT (Air Passenger Transport) and HSR (High Speed Rail) systems. The considered performances are operational, financial, social and environmental.

'Chicken’ in Somali class. Unbounded use of linguistic resources across a compartmentalised language curriculum

DEFF Research Database (Denmark)

Daugaard, Line Møller

impact on what counts as desirable language(s), apt linguistic norms and ideals, relevant activities and appropriate ways of managing linguistic diversity in the classroom. A linguistic ethnographic analysis of Abdullahi’s skilfully calibrated linguistic performances in the language classroom at the same...

Effect of Aluminum Substrate Surface Modification on Wettability and Freezing Delay of Water Droplet at Subzero Temperatures

DEFF Research Database (Denmark)

Rahimi, Maral; Afshari, Alireza; Thormann, Esben

2016-01-01

followed the trend in this theory, the differences in the extents of freezing delays were in apparent disagreement with the predictions. Concretely, a slightly hydrophilic substrate modified by (3-aminopropyl) triethoxysilane (APTES) showed longer freezing delays than both more hydrophilic and more...

Re-Emerging Frontiers: Postcolonial Theory and Historical Archaeology of the Borderlands

DEFF Research Database (Denmark)

Naum, Magdalena

2010-01-01

processes in borderlands that were created by colonial empires. They are also an apt way to conceptualize relationships in frontiers that lacked colonial stigma. To illustrate this point, two different historical examples of borderlands are scrutinized in this paper: the medieval frontier region...

Report of tour of duty to the USA: 14 October 1999 to 26 October 1999

CSIR Research Space (South Africa)

Steyn, WJvdM

1999-11-01

Full Text Available This report describes a tour of duty undertaken to the USA in October 1999. The objectives of this tour of duty were to attend the 1999 Reno APT Conference, visit to smart material companies and visit the Palmdale HVS site....

Problems of elderly patients on inhalation therapy: Difference in problem recognition between patients and medical professionals

Directory of Open Access Journals (Sweden)

Daiki Hira

2016-10-01

Conclusions: Elderly patients are apt to assume that they “understand well”, therefore, in order to recognize and close the perception gap between elderly patients and medical professionals, it is necessary to provide them with more aggressive (frequent instructions on inhalation therapy.

Silicalite-1 zeolite membranes on unmodified and modified surfaces

Indian Academy of Sciences (India)

Silicalite-1 zeolite membranes were prepared hydrothermally on the porous ceramic supports, both unmodified and modified with 3-aminopropyl triethoxysilane (APTES) as a coupling agent following ex situ (secondary) crystal growth process. The microstructure of the membranes was examined by scanning electron ...

A multidimensonal Examination of Prefomences of the Future advanced Transport Systems: The ETT (Evacuated Tube Transport) TRM (Transrapid MAGLEV) System

NARCIS (Netherlands)

Janic, M.

2016-01-01

Multidimensional examination of performances of the future advanced ETT Evacuated Tube Transport) system operated by TRM (TransRapidMaglev); assessment of the ETT TRM system contribution to sustainability of the future transport sector through its completion with APT (Air Passenger Transport) system

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African Journals Online (AJOL)

Ezenwafor

their feeling of deficient in the ability of achieving self-worth. Whittaker and Msiska aptly ... activities of the Igbo, particularly, as they affect women. Through proverbs the ..... here is the punishment for the men; when a man sees a woman whom ...