A compact disc under skimming light rays

NASA Astrophysics Data System (ADS)

De Luca, R.; Di Mauro, M.; Fiore, O.; Naddeo, A.

2018-03-01

The optical properties of a compact disc (CD) under "skimming" light rays have been analyzed. We have noticed that a clear green line can be detected when the disc is irradiated with light rays coming from a lamp in such a way that only those skimming the CD, held horizontally, are selected. We provide a physical interpretation of this phenomenon on the basis of elementary optics concepts. Extension of these concepts to digital versatile discs (DVDs) is given.

Haemoglobin content modulated deformation dynamics of red blood cells on a compact disc.

PubMed

Kar, Shantimoy; Ghosh, Uddipta; Maiti, Tapas Kumar; Chakraborty, Suman

2015-12-21

We investigate the deformation characteristics of red blood cells (RBCs) on a rotating compact disc platform. Our study brings out the interplay between haemoglobin content and RBC deformability in a centrifugally actuated microfluidic environment. We reveal that RBC deformations follow the similar trend of principal stress distributed throughout the radial direction, rendering an insight into the mechano-physical processes involved. This study can be used as a diagnostic marker to determine haematological disorders in diseased blood samples tested on compact disc based microfluidic platforms.

Albemarle County/City of Charlottesville transportation planning compact disc.

DOT National Transportation Integrated Search

1998-06-01

This report describes transportation planning data, available in numerous files and formats stored on the accompanying compact disc, that were compiled from planning studies for the Charlottesville/Albemarle area done in 1967, 1979, and 1990. These d...

Growth and characterization of EDTA assisted CBD-CdS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumarage, W. G. C.; Wijesundera, R. P.; Seneviratne, V. A.

2017-10-01

Chemical bath deposition of CdS (CBD-CdS) thin films with the assistance of a cationic surfactant, ethylenediamine tetraacetic acid (EDTA), is reported in this work. Also the EDTA treated CdS thin films are compared with that of conventional CBD-CdS. Fabricated thin, compact, uniform and adherent EDTA treated CdS films show enhanced effective surface area and roughness compared to conventional CBD-CdS. The grazing incidence x-ray diffraction analysis shows all the fabricated CdS films are hexagonally crystallized. EDTA-treated CdS films show excellent photo activity compared to conventional CBDCdS. The flat band potential (Vfb) value was found to be tunable with EDTA concentration.

Ultra Compact Optical Pickup with Integrated Optical System

NASA Astrophysics Data System (ADS)

Nakata, Hideki; Nagata, Takayuki; Tomita, Hironori

2006-08-01

Smaller and thinner optical pickups are needed for portable audio-visual (AV) products and notebook personal computers (PCs). We have newly developed an ultra compact recordable optical pickup for Mini Disc (MD) that measures less than 4 mm from the disc surface to the bottom of the optical pickup, making the optical system markedly compact. We have integrated all the optical components into an objective lens actuator moving unit, while fully satisfying recording and playback performance requirements. In this paper, we propose an ultra compact optical pickup applicable to portable MD recorders.

Modeling the Compact Disc Read System in Lab

ERIC Educational Resources Information Center

Hinaus, Brad; Veum, Mick

2009-01-01

One of the great, engaging aspects of physics is its application to everyday technology. The compact disc player is an example of one such technology that applies fundamental principles from optics in order to efficiently store and quickly retrieve information. We have created a lab in which students use simple optical components to assemble a…

A study on the enhancement of opto-electronic properties of CdS thin films: seed-assisted fabrication

NASA Astrophysics Data System (ADS)

Kumarage, W. G. C.; Wijesundera, R. P.; Seneviratne, V. A.; Jayalath, C. P.; Dassanayake, B. S.

2017-04-01

A novel method of fabricating chemical bath deposited CdS thin films (CBD-CdS) by using electrodeposited CdS (ED-CdS) as a seed layer is reported. The resulting thin, compact, uniform and adherent seed-assisted CdS films (ED/CBD-CdS) show enhanced effective surface area compared to both ED-CdS and CBD-CdS. The phase of these CdS films was determined to be hexagonal. The fabricated ED/CBD-CdS films show higher photoelectrochemical (PEC) cell efficiency than either ED-CdS and CBD-CdS thin films. Carrier concentration and flat band potential values for ED/CBD-CdS systems are also found to be superior compared to both ED-CdS and CBD-CdS systems.

Simulating the X-ray luminosity of Be X-ray binaries: the case for black holes versus neutron stars

NASA Astrophysics Data System (ADS)

Brown, R. O.; Ho, W. C. G.; Coe, M. J.; Okazaki, A. T.

2018-04-01

There are over 100 Be stars that are known to have neutron star companions but only one such system with a black hole. Previous theoretical work suggests this is not due to their formation but due to differences in X-ray luminosity. It has also been proposed that the truncation of the Be star's circumstellar disc is dependent on the mass of the compact object. Hence, Be star discs in black hole binaries are smaller. Since accretion onto the compact object from the Be star's disc is what powers the X-ray luminosity, a smaller disc in black hole systems leads to a lower luminosity. In this paper, simulations are performed with a range of eccentricities and compact object mass. The disc's size and density are shown to be dependent on both quantities. Mass capture and, in turn, X-ray luminosity are heavily dependent on the size and density of the disc. Be/black hole binaries are expected to be up to ˜10 times fainter than Be/neutron star binaries when both systems have the same eccentricity and can be 100 times fainter when comparing systems with different eccentricity.

Antimicrobial activity, cytotoxicity and DNA binding studies of carbon dots

NASA Astrophysics Data System (ADS)

Jhonsi, Mariadoss Asha; Ananth, Devanesan Arul; Nambirajan, Gayathri; Sivasudha, Thilagar; Yamini, Rekha; Bera, Soumen; Kathiravan, Arunkumar

2018-05-01

In recent years, quantum dots (QDs) are one of the most promising nanomaterials in life sciences community due to their unexploited potential in biomedical applications; particularly in bio-labeling and sensing. In the advanced nanomaterials, carbon dots (CDs) have shown promise in next generation bioimaging and drug delivery studies. Therefore the knowledge of the exact nature of interaction with biomolecules is of great interest to designing better biosensors. In this study, the interaction between CDs derived from tamarind and calf thymus DNA (ct-DNA) has been studied by vital spectroscopic techniques, which revealed that the CDs could interact with DNA via intercalation. The apparent association constant has been deduced from the absorption spectral changes of ct-DNA-CDs using the Benesi-Hildebrand equation. From the DNA induced emission quenching experiments the apparent DNA binding constant of the CDs (Kapp) have also been evaluated. Furthermore, we have analyzed the antibacterial and antifungal activity of CDs using disc diffusion assay method which exhibited excellent activity against E. coli and C. albicans with inhibition zone in the range of 7-12 mm. The biocompatible nature of CDs was confirmed by an in vitro cytotoxicity test on L6 normal rat myoblast cells by using MTT assay. The cell viability is not affected till the high dosage of CDs (200 μg/mL) for >48 h. As a consequence of the work, future development of CDs for microbial control and DNA sensing among the various biomolecules is possible in view of emerging biofields.

Transparent sunlight conversion film based on carboxymethyl cellulose and carbon dots.

PubMed

You, Yaqin; Zhang, Haoran; Liu, Yingliang; Lei, Bingfu

2016-10-20

Transparent sunlight conversion film based on carboxymethyl cellulose (CMC) and carbon dots (CDs) has been developed for the first time through dispersion of CDs in CMC aqueous solution. Due to the hydrogen bonds interaction, CMC can effectively absorb the CDs, whose surfaces are functionalized by lots of polar groups. The results from atomic force microscopy (AFM), scanning electron microscopy (SEM) confirm that the composite film possesses a homogeneous and compact structure. Besides, the CMC matrix neither competes for absorbing excitation light nor absorbs the emissions of CDs, which reserves the inherent optical properties of the individual CDs. The composite films can efficiently convert ultraviolet light to blue light. What's more, the film is transparent and possesses excellent mechanical properties, expected to apply in the field of agricultural planting for sunlight conversion. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Past, Present and Future of the Compact Disc, Multimedia and the Industry: An Interview with Sony's Dr. Toshi Doi.

ERIC Educational Resources Information Center

Herther, Nancy

1992-01-01

This interview with Dr. Toshi Doi, director of the Sony Corporation, covers his work at Sony, the multimedia industry, industry cooperation, Sony compact disc products and formats, multimedia standards and pricing, multimedia formats, and the future of the industry. A diagram of computer companies and corresponding multimedia platforms is…

Real-time high-resolution PC-based system for measurement of errors on compact disks

NASA Astrophysics Data System (ADS)

Tehranchi, Babak; Howe, Dennis G.

1994-10-01

Hardware and software utilities are developed to directly monitor the Eight-to-Fourteen (EFM) demodulated data bytes at the input of a CD player's Cross-Interleaved Reed-Solomon Code (CIRC) block decoder. The hardware is capable of identifying erroneous data with single-byte resolution in the serial data stream read from a Compact Disc by a CDD 461 Philips CD-ROM drive. In addition, the system produces graphical maps that show the physical location of the measured errors on the entire disc, or via a zooming and planning feature, on user selectable local disc regions.

Compact binary merger and kilonova: outflows from remnant disc

NASA Astrophysics Data System (ADS)

Yi, Tuan; Gu, Wei-Min; Liu, Tong; Kumar, Rajiv; Mu, Hui-Jun; Song, Cui-Ying

2018-05-01

Outflows launched from a remnant disc of compact binary merger may have essential contribution to the kilonova emission. Numerical calculations are conducted in this work to study the structure of accretion flows and outflows. By the incorporation of limited-energy advection in the hyper-accretion discs, outflows occur naturally from accretion flows due to imbalance between the viscous heating and the sum of the advective and radiative cooling. Following this spirit, we revisit the properties of the merger outflow ejecta. Our results show that around 10-3 ˜ 10-1 M⊙ of the disc mass can be launched as powerful outflows. The amount of unbound mass varies with the disc mass and the viscosity. The outflow-contributed peak luminosity is around 1040 ˜ 1041 erg s-1. Such a scenario can account for the observed kilonovae associated with short gamma-ray bursts, including the recent event AT2017gfo (GW170817).

A disc inside the bipolar planetary nebula M2-9

NASA Astrophysics Data System (ADS)

Lykou, F.; Chesneau, O.; Zijlstra, A. A.; Castro-Carrizo, A.; Lagadec, E.; Balick, B.; Smith, N.

2011-03-01

Aims: Bipolarity in proto-planetary and planetary nebulae is associated with events occurring in or around their cores. Past infrared observations have revealed the presence of dusty structures around the cores, many in the form of discs. Characterising those dusty discs provides invaluable constraints on the physical processes that govern the final mass expulsion of intermediate mass stars. We focus this study on the famous M2-9 bipolar nebula, where the moving lighthouse beam pattern indicates the presence of a wide binary. The compact and dense dusty core in the centre of the nebula can be studied by means of optical interferometry. Methods: M2-9 was observed with VLTI/MIDI at 39-47 m baselines with the UT2-UT3 and UT3-UT4 baseline configurations. These observations are interpreted using a dust radiative transfer Monte Carlo code. Results: A disc-like structure is detected perpendicular to the lobes, and a good fit is found with a stratified disc model composed of amorphous silicates. The disc is compact, 25 × 35 mas at 8 μm and 37 × 46 mas at 13 μm. For the adopted distance of 1.2 kpc, the inner rim of the disc is ~15 AU. The mass represents a few percent of the mass found in the lobes. The compactness of the disc puts strong constraints on the binary content of the system, given an estimated orbital period 90-120 yr. We derive masses of the binary components between 0.6-1.0 M⊙ for a white dwarf and 0.6-1.4 M⊙ for an evolved star. We present different scenarios on the geometric structure of the disc accounting for the interactions of the binary system, which includes an accretion disc as well. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, ESO N: 079.D-146.

Using and Developing with CD-Interactive: Frequently Asked Questions Are Answered.

ERIC Educational Resources Information Center

Lediaev, Lucy; van Sonderen, Lex

1994-01-01

Discusses Compact Disc-Interactive (CD-I) using a question-and-answer format. Highlights include development of the CD-I technology; where to purchase discs and players; compatibility with other CD-ROM drives; how to make discs; authoring systems versus custom programs; entertainment and educational applications; licensing issues; specifications;…

The Reading Disc: Learning to Read Using Interactive CD.

ERIC Educational Resources Information Center

Shaw, Simon

1991-01-01

Describes the development of an interactive compact disc on CD-ROM XA that was designed to help adults learn to read. The application of technology to learning is discussed, differences in learner control in computer-based systems are considered, virtual writing is described, and assessment activities available on the disc are explained. (five…

Wet disc contraction to galactic blue nuggets and quenching to red nuggets

NASA Astrophysics Data System (ADS)

Dekel, A.; Burkert, A.

2014-02-01

We study the origin of high-redshift, compact, quenched spheroids (red nuggets) through the dissipative shrinkage of gaseous discs into compact star-forming systems (blue nuggets). The discs, fed by cold streams, undergo violent disc instability that drives gas into the centre (along with mergers). The inflow is dissipative when its time-scale is shorter than the star formation time-scale. This implies a threshold of ˜0.28 in the cold-to-total mass ratio within the disc radius. For the typical gas fraction ˜0.5 at z ˜ 2, this threshold is traced back to a maximum spin parameter of ˜0.05, implying that ˜half the star-forming galaxies contract to blue nuggets, while the rest form extended stellar discs. Thus, the surface density of blue galaxies is expected to be bimodal about ˜109 M⊙ kpc-2, slightly increasing with mass. The blue nuggets are expected to be rare at low z when the gas fraction is low. The blue nuggets quench to red nuggets by complementary internal and external mechanisms. Internal quenching by a compact bulge, in a fast mode and especially at high z, may involve starbursts, stellar and active galactic nucleus feedback, or Q-quenching. Quenching due to hot-medium haloes above 1012 M⊙ provides maintenance and a slower mode at low redshift. These predictions are confirmed in simulations and are consistent with observations at z = 0-3.

Reducing the anisotropy of a Brazilian disc generated in a bonded-particle model

NASA Astrophysics Data System (ADS)

Zhang, Q.; Zhang, X. P.; Ji, P. Q.

2018-03-01

The Brazilian test is a widely used method for determining the tensile strength of rocks and for calibrating parameters in bonded-particle models (BPMs). In previous studies, the Brazilian disc has typically been trimmed from a compacted rectangular specimen. The present study shows that different tensile strength values are obtained depending on the compressive loading direction. Several measures are proposed to reduce the anisotropy of the disc. The results reveal that the anisotropy of the disc is significantly influenced by the compactibility of the specimen from which it is trimmed. A new method is proposed in which the Brazilian disc is directly generated with a particle boundary, effectively reducing the anisotropy. The stiffness (particle and bond) and strength (bond) of the boundary are set at less than and greater than those of the disc assembly, respectively, which significantly decreases the stress concentration at the boundary contacts and prevents breakage of the boundary particle bonds. This leads to a significant reduction in the anisotropy of the disc and the discreteness of the tensile strength. This method is more suitable for carrying out a realistic Brazilian test for homogeneous rock-like material in the BPM.

DUst around NEarby Stars. The survey observational results

NASA Astrophysics Data System (ADS)

Eiroa, C.; Marshall, J. P.; Mora, A.; Montesinos, B.; Absil, O.; Augereau, J. Ch.; Bayo, A.; Bryden, G.; Danchi, W.; del Burgo, C.; Ertel, S.; Fridlund, M.; Heras, A. M.; Krivov, A. V.; Launhardt, R.; Liseau, R.; Löhne, T.; Maldonado, J.; Pilbratt, G. L.; Roberge, A.; Rodmann, J.; Sanz-Forcada, J.; Solano, E.; Stapelfeldt, K.; Thébault, P.; Wolf, S.; Ardila, D.; Arévalo, M.; Beichmann, C.; Faramaz, V.; González-García, B. M.; Gutiérrez, R.; Lebreton, J.; Martínez-Arnáiz, R.; Meeus, G.; Montes, D.; Olofsson, G.; Su, K. Y. L.; White, G. J.; Barrado, D.; Fukagawa, M.; Grün, E.; Kamp, I.; Lorente, R.; Morbidelli, A.; Müller, S.; Mutschke, H.; Nakagawa, T.; Ribas, I.; Walker, H.

2013-07-01

Context. Debris discs are a consequence of the planet formation process and constitute the fingerprints of planetesimal systems. Their solar system counterparts are the asteroid and Edgeworth-Kuiper belts. Aims: The DUNES survey aims at detecting extra-solar analogues to the Edgeworth-Kuiper belt around solar-type stars, putting in this way the solar system into context. The survey allows us to address some questions related to the prevalence and properties of planetesimal systems. Methods: We used Herschel/PACS to observe a sample of nearby FGK stars. Data at 100 and 160 μm were obtained, complemented in some cases with observations at 70 μm, and at 250, 350 and 500 μm using SPIRE. The observing strategy was to integrate as deep as possible at 100 μm to detect the stellar photosphere. Results: Debris discs have been detected at a fractional luminosity level down to several times that of the Edgeworth-Kuiper belt. The incidence rate of discs around the DUNES stars is increased from a rate of ~12.1% ± 5% before Herschel to ~20.2% ± 2%. A significant fraction (~52%) of the discs are resolved, which represents an enormous step ahead from the previously known resolved discs. Some stars are associated with faint far-IR excesses attributed to a new class of cold discs. Although it cannot be excluded that these excesses are produced by coincidental alignment of background galaxies, statistical arguments suggest that at least some of them are true debris discs. Some discs display peculiar SEDs with spectral indexes in the 70-160 μm range steeper than the Rayleigh-Jeans one. An analysis of the debris disc parameters suggests that a decrease might exist of the mean black body radius from the F-type to the K-type stars. In addition, a weak trend is suggested for a correlation of disc sizes and an anticorrelation of disc temperatures with the stellar age. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendices are available in electronic form at http://www.aanda.orgTables 14 and 15 are also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/555/A11Full Tables 2-5, 10 and 12 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/555/A11

Patient-directed Internet-based Medical Image Exchange: Experience from an Initial Multicenter Implementation

PubMed Central

Greco, Giampaolo; Patel, Anand S.; Lewis, Sara C.; Shi, Wei; Rasul, Rehana; Torosyan, Mary; Erickson, Bradley J.; Hiremath, Atheeth; Moskowitz, Alan J.; Tellis, Wyatt M.; Siegel, Eliot L.; Arenson, Ronald L.; Mendelson, David S.

2015-01-01

Rationale and Objectives Inefficient transfer of personal health records among providers negatively impacts quality of health care and increases cost. This multicenter study evaluates the implementation of the first Internet-based image-sharing system that gives patients ownership and control of their imaging exams, including assessment of patient satisfaction. Materials and Methods Patients receiving any medical imaging exams in four academic centers were eligible to have images uploaded into an online, Internet-based personal health record. Satisfaction surveys were provided during recruitment with questions on ease of use, privacy and security, and timeliness of access to images. Responses were rated on a five-point scale and compared using logistic regression and McNemar's test. Results A total of 2562 patients enrolled from July 2012 to August 2013. The median number of imaging exams uploaded per patient was 5. Most commonly, exams were plain X-rays (34.7%), computed tomography (25.7%), and magnetic resonance imaging (16.1%). Of 502 (19.6%) patient surveys returned, 448 indicated the method of image sharing (Internet, compact discs [CDs], both, other). Nearly all patients (96.5%) responded favorably to having direct access to images, and 78% reported viewing their medical images independently. There was no difference between Internet and CD users in satisfaction with privacy and security and timeliness of access to medical images. A greater percentage of Internet users compared to CD users reported access without difficulty (88.3% vs. 77.5%, P < 0.0001). Conclusion A patient-directed, interoperable, Internet-based image-sharing system is feasible and surpasses the use of CDs with respect to accessibility of imaging exams while generating similar satisfaction with respect to privacy. PMID:26625706

Patient-directed Internet-based Medical Image Exchange: Experience from an Initial Multicenter Implementation.

PubMed

Greco, Giampaolo; Patel, Anand S; Lewis, Sara C; Shi, Wei; Rasul, Rehana; Torosyan, Mary; Erickson, Bradley J; Hiremath, Atheeth; Moskowitz, Alan J; Tellis, Wyatt M; Siegel, Eliot L; Arenson, Ronald L; Mendelson, David S

2016-02-01

Inefficient transfer of personal health records among providers negatively impacts quality of health care and increases cost. This multicenter study evaluates the implementation of the first Internet-based image-sharing system that gives patients ownership and control of their imaging exams, including assessment of patient satisfaction. Patients receiving any medical imaging exams in four academic centers were eligible to have images uploaded into an online, Internet-based personal health record. Satisfaction surveys were provided during recruitment with questions on ease of use, privacy and security, and timeliness of access to images. Responses were rated on a five-point scale and compared using logistic regression and McNemar's test. A total of 2562 patients enrolled from July 2012 to August 2013. The median number of imaging exams uploaded per patient was 5. Most commonly, exams were plain X-rays (34.7%), computed tomography (25.7%), and magnetic resonance imaging (16.1%). Of 502 (19.6%) patient surveys returned, 448 indicated the method of image sharing (Internet, compact discs [CDs], both, other). Nearly all patients (96.5%) responded favorably to having direct access to images, and 78% reported viewing their medical images independently. There was no difference between Internet and CD users in satisfaction with privacy and security and timeliness of access to medical images. A greater percentage of Internet users compared to CD users reported access without difficulty (88.3% vs. 77.5%, P < 0.0001). A patient-directed, interoperable, Internet-based image-sharing system is feasible and surpasses the use of CDs with respect to accessibility of imaging exams while generating similar satisfaction with respect to privacy. Copyright © 2015 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

DISC-BASED IMMUNOASSAY MICROARRAYS. (R825433)

EPA Science Inventory

Microarray technology as applied to areas that include genomics, diagnostics, environmental, and drug discovery, is an interesting research topic for which different chip-based devices have been developed. As an alternative, we have explored the principle of compact disc-based...

Angular Speed of a Compact Disc

NASA Astrophysics Data System (ADS)

Sawicki, Mikolaj ``Mik''

2006-09-01

A spinning motion of a compact disc in a CD player offers an interesting and challenging problem in rotational kinematics with a nonconstant angular acceleration that can be incorporated into a typical introductory physics class for engineers and scientists. It can be used either as an example presented during the lecture, emphasizing application of calculus, or as a homework assignment that could be handled easily with the help of a spreadsheet, thus eliminating the calculus aspect altogether. I tried both approaches, and the spreadsheet study was favored by my students.

16 CFR 4.2 - Requirements as to form, and filing of documents other than correspondence.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Administrative Law Judge) or twelve (12) paper copies (if before the Commission), and an electronic copy in Adobe... an electronic copy on a compact disc (CD) or digital video disc (DVD) in Adobe portable document...

16 CFR 4.2 - Requirements as to form, and filing of documents other than correspondence.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Administrative Law Judge) or twelve (12) paper copies (if before the Commission), and an electronic copy in Adobe... an electronic copy on a compact disc (CD) or digital video disc (DVD) in Adobe portable document...

Formation of S0s via disc accretion around high-redshift compact ellipticals

NASA Astrophysics Data System (ADS)

Diaz, Jonathan; Bekki, Kenji; Forbes, Duncan A.; Couch, Warrick J.; Drinkwater, Michael J.; Deeley, Simon

2018-06-01

We present hydrodynamical N-body models which demonstrate that elliptical galaxies can transform into S0s by acquiring a disc. In particular, we show that the merger with a massive gas-rich satellite can lead to the formation of a baryonic disc around an elliptical. We model the elliptical as a massive, compact galaxy which could be observed as a `red nugget' in the high-z universe. This scenario contrasts with existing S0 formation scenarios in the literature in two important ways. First, the progenitor is an elliptical galaxy whereas scenarios in the literature typically assume a spiral progenitor. Secondly, the physical conditions underlying our proposed scenario can exist in low-density environments such as the field, in contrast to scenarios in the literature which typically address dense environments like clusters and groups. As a consequence, S0s in the field may be the most likely candidates to have evolved from elliptical progenitors. Our scenario also naturally explains recent observations which indicate that field S0s may have older bulges than discs, contrary to cluster S0s which seem to have older discs than bulges.

Fabrication and investigation of the optoelectrical properties of MoS2/CdS heterojunction solar cells

PubMed Central

2014-01-01

Molybdenum disulfide (MoS2)/cadmium sulfide (CdS) heterojunction solar cells were successfully synthesized via chemical bath deposition (CBD) and chemical vapor deposition (CVD). The as-grown CdS film on a fluorine tin oxide (FTO) substrate deposited by CBD is continuous and compact. The MoS2 film deposited by CVD is homogeneous and continuous, with a uniform color and a thickness of approximately 10 nm. The optical absorption range of the MoS2/CdS heterojunction covers the visible and near-infrared spectral regions of 350 to 800 nm, which is beneficial for the improvement of solar cell efficiency. Moreover, the MoS2/CdS solar cell exhibits good current-voltage (I-V) characteristics and pronounced photovoltaic behavior, with an open-circuit voltage of 0.66 V and a short-circuit current density of 0.227 × 10-6 A/cm2, comparable to the results obtained from other MoS2-based solar cells. This research is critical to investigate more efficient and stable solar cells based on graphene-like materials in the future. PMID:25593552

40 CFR 3.1 - Who does this part apply to?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Regulations (CFR); and (2) States, tribes, and local governments administering or seeking to administer..., compact disc, digital video disc, or tape in satisfaction of reporting requirements, as permitted under... does not apply to any data transfers between EPA and states, tribes, or local governments as a part of...

Recent Developments in Interactive and Communicative CALL: Hypermedia and "Intelligent" Systems.

ERIC Educational Resources Information Center

Coughlin, Josette M.

Two recent developments in computer-assisted language learning (CALL), interactive video systems and "intelligent" games, are discussed. Under the first heading, systems combining the use of a computer and video disc player are described, and Compact Discs Interactive (CDI) and Digital Video Interactive (DVI) are reviewed. The…

Medical Information on Optical Disc*

PubMed Central

Schipma, Peter B.; Cichocki, Edward M.; Ziemer, Susan M.

1987-01-01

Optical discs may permit a revolutionary change in the distribution and use of medical information. A single compact disc, similar in size to that used for digital audio recording, can contain over 500 million characters of information that is accessible by a Personal Computer. These discs can be manufactured at a cost lower than that of print on paper, at reasonable volumes. Software can provide the health care professional with nearly instantaneous access to the information. Thus, for the first time, the opportunity exists to have large local medical information collections. This paper describes an application of this technology in the field of Oncology.

Multimedia Archiving: Videotape, Compact Disc (CD), Digital Versatile Disc (DVD), and Blu-Ray Disc (BD) Media

DTIC Science & Technology

2010-02-01

color and memory SMPTE Society of Motion Picture and Television Engineers SP Superior Performance ( Betacam SP) S-VHS Super VHS TBC time base...modified Iron Oxide 1.5 mil 3/4 inch ENG, Independent production Betamax 1/2 inch Consumer Betacam Cobalt-modified Iron Oxide, Chromium Dioxide 0.8...mil 1/2 inch ENG, Independent production, Government Betacam SP Metal particle 0.55 mil 1/2 inch ENG, Independent production M-II Metal particle

N-body simulations of planet formation: understanding exoplanet system architectures

NASA Astrophysics Data System (ADS)

Coleman, Gavin; Nelson, Richard

2015-12-01

Observations have demonstrated the existence of a significant population of compact systems comprised of super-Earths and Neptune-mass planets, and a population of gas giants that appear to occur primarily in either short-period (<10 days) or longer period (>100 days) orbits. The broad diversity of system architectures raises the question of whether or not the same formation processes operating in standard disc models can explain these planets, or if different scenarios are required instead to explain the widely differing architectures. To explore this issue, we present the results from a comprehensive suite of N-body simulations of planetary system formation that include the following physical processes: gravitational interactions and collisions between planetary embryos and planetesimals; type I and II migration; gas accretion onto planetary cores; self-consistent viscous disc evolution and disc removal through photo-evaporation. Our results indicate that the formation and survival of compact systems of super-Earths and Neptune-mass planets occur commonly in disc models where a simple prescription for the disc viscosity is assumed, but such models never lead to the formation and survival of gas giant planets due to migration into the star. Inspired in part by the ALMA observations of HL Tau, and by MHD simulations that display the formation of long-lived zonal flows, we have explored the consequences of assuming that the disc viscosity varies in both time and space. We find that the radial structuring of the disc leads to conditions in which systems of giant planets are able to form and survive. Furthermore, these giants generally occupy those regions of the mass-period diagram that are densely populated by the observed gas giants, suggesting that the planet traps generated by radial structuring of protoplanetary discs may be a necessary ingredient for forming giant planets.

CD-ROM and Libraries.

ERIC Educational Resources Information Center

Murphy, Brower

1985-01-01

The Compact Disc-Read Only Memory (CD-ROM) data format is explained and illustrated, noting current and potential applications. The "5-inch" compact laserdisc is described and photographs of an IBM PC/Hitachi CD-ROM system adopted by Library Corporation to support its MARC database--BiblioFile--are presented. Screen displays for…

Study of the suitability of a commercial hydroxyapatite powder to obtain sintered compacts for medical applications

NASA Astrophysics Data System (ADS)

Palacio, C.; Jaramillo, D.; Correa, S.; Arroyave, M.

2017-06-01

Hydroxyapatite (HA) is a material widely used by the medical community due to its Ca/P ratio is comparable to the Ca/P ratio of bones and teeth, which promotes osteoinduction and osteoconduction processes when in contact with bone tissue, either as volume piece or coating. This work focuses on studying the quality of the commercial HA powder MKnano-#MKN-HXAP-S12 µm, after processing, to obtain sintered compact discs with suitable physical and chemical characteristics for implants applications. The HA powder was processed through calcination, grinding, pressing and sintering to evaluate the effect of such as procedures in the compacts dics quality. The raw powder was characterized by laser diffraction, SEM, XRF, XRD, TGA and DSC while the characteristics of the obtained compact discs were determined by dilatometry and XRD to identify the sintering temperature range, constituent phases, the amorphous content and the crystallinity degree, parameters that allow determining their suitability for implants applications. Although, it was not possible to obtain sintered compacts with the suitable chemical composition and without fractures, this work allowed to identify the parameters that determine the suitability of a HA powder to obtain sintered compacts for medical applications, as well as the characterization protocol that allows the evaluation of such parameters.

Trapping of low-mass planets outside the truncated inner edges of protoplanetary discs

NASA Astrophysics Data System (ADS)

Miranda, Ryan; Lai, Dong

2018-02-01

We investigate the migration of a low-mass (≲10 M⊕) planet near the inner edge of a protoplanetary disc using two-dimensional viscous hydrodynamics simulations. We employ an inner boundary condition representing the truncation of the disc at the stellar corotation radius. As described by Tsang, wave reflection at the inner disc boundary modifies the Type I migration torque on the planet, allowing migration to be halted before the planet reaches the inner edge of the disc. For low-viscosity discs (α ≲ 10-3), planets may be trapped with semi-major axes as large as three to five times the inner disc radius. In general, planets are trapped closer to the inner edge as either the planet mass or the disc viscosity parameter α increases, and farther from the inner edge as the disc thickness is increased. This planet trapping mechanism may impact the formation and migration history of close-in compact multiplanet systems.

Sample-to-answer palm-sized nucleic acid testing device towards low-cost malaria mass screening.

PubMed

Choi, Gihoon; Prince, Theodore; Miao, Jun; Cui, Liwang; Guan, Weihua

2018-05-19

The effectiveness of malaria screening and treatment highly depends on the low-cost access to the highly sensitive and specific malaria test. We report a real-time fluorescence nucleic acid testing device for malaria field detection with automated and scalable sample preparation capability. The device consists a compact analyzer and a disposable microfluidic reagent compact disc. The parasite DNA sample preparation and subsequent real-time LAMP detection were seamlessly integrated on a single microfluidic compact disc, driven by energy efficient non-centrifuge based magnetic field interactions. Each disc contains four parallel testing units which could be configured either as four identical tests or as four species-specific tests. When configured as species-specific tests, it could identify two of the most life-threatening malaria species (P. falciparum and P. vivax). The NAT device is capable of processing four samples simultaneously within 50 min turnaround time. It achieves a detection limit of ~0.5 parasites/µl for whole blood, sufficient for detecting asymptomatic parasite carriers. The combination of the sensitivity, specificity, cost, and scalable sample preparation suggests the real-time fluorescence LAMP device could be particularly useful for malaria screening in the field settings. Copyright © 2018 Elsevier B.V. All rights reserved.

CD, DVD, and Blu-Ray Disc Diffraction with a Laser Ray Box

ERIC Educational Resources Information Center

DeWeerd, Alan J.

2016-01-01

A compact disc (CD) can be used as a diffraction grating, even though its track consists of a series of pits, not a continuous groove. Previous authors described how to measure the track spacing on a CD using an incident laser beam normal to the surface or one at an oblique angle. In both cases, the diffraction pattern was projected on a screen…

In Praise of Mr. S. Platter and His Marvelous, Magnificent CD ROM Laser Disc Index for ERIC and PSYCHLIT.

ERIC Educational Resources Information Center

Huffman, Robert F.

These instructions are designed to help patrons of the University of Missouri-Columbia library perform searches on PSYCHLIT, a CD-ROM (compact disc, read only memory) version of the Psych Abstracts database, and a CD-ROM version of the ERIC database, both produced by SilverPlatter Information Services. Basic information is provided about the disk…

Conversion of a traditional image archive into an image resource on compact disc.

PubMed Central

Andrew, S M; Benbow, E W

1997-01-01

The conversion of a traditional archive of pathology images was organised on 35 mm slides into a database of images stored on compact disc (CD-ROM), and textual descriptions were added to each image record. Students on a didactic pathology course found this resource useful as an aid to revision, despite relative computer illiteracy, and it is anticipated that students on a new problem based learning course, which incorporates experience with information technology, will benefit even more readily when they use the database as an educational resource. A text and image database on CD-ROM can be updated repeatedly, and the content manipulated to reflect the content and style of the courses it supports. Images PMID:9306931

Effects of different annealing atmospheres on the properties of cadmium sulfide thin films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yücel, E., E-mail: dr.ersinyucel@gmail.com; Kahraman, S.; Güder, H.S.

2015-08-15

Graphical abstract: The effects of different annealing atmospheres (air and sulfur) on the structural, morphological and optical properties of CdS thin films were studied at three different pH values. - Highlights: • Compactness and smoothness of the films were enhanced after sulfur annealing. • Micro-strain values of some films were improved after sulfur annealing. • Dislocation density values of some films were improved after sulfur annealing. • Band gap values of the films were improved after sulfur annealing. - Abstract: Cadmium sulfide (CdS) thin films were prepared on glass substrates by using chemical bath deposition (CBD) technique. The effects ofmore » different annealing atmospheres (air and sulfur) on the structural, morphological and optical properties of CdS thin films were studied at three different pH values. Compactness and smoothness of the films (especially for pH 10.5 and 11) enhanced after sulfur annealing. pH value of the precursor solution remarkably affected the roughness, uniformity and particle sizes of the films. Based on the analysis of X-ray diffraction (XRD) patterns of the films, micro-strain and dislocation density values of the sulfur-annealed films (pH 10.5 and 11) were found to be lower than those of air-annealed films. Air-annealed films (pH 10.5, 11 and 11.5) exhibited higher transmittance than sulfur-annealed films in the wavelength region of 550–800 nm. Optical band gap values of the films were found between 2.31 eV and 2.36 eV.« less

Take-home video for adult literacy

NASA Astrophysics Data System (ADS)

Yule, Valerie

1996-01-01

In the past, it has not been possible to "teach oneself to read" at home, because learners could not read the books to teach them. Videos and interactive compact discs have changed that situation and challenge current assumptions of the pedagogy of literacy. This article describes an experimental adult literacy project using video technology. The language used is English, but the basic concepts apply to any alphabetic or syllabic writing system. A half-hour cartoon video can help adults and adolescents with learning difficulties. Computer-animated cartoon graphics are attractive to look at, and simplify complex material in a clear, lively way. This video technique is also proving useful for distance learners, children, and learners of English as a second language. Methods and principles are to be extended using interactive compact discs.

Correlating non-linear properties with spectral states of RXTE data: possible observational evidences for four different accretion modes around compact objects

NASA Astrophysics Data System (ADS)

Adegoke, Oluwashina; Dhang, Prasun; Mukhopadhyay, Banibrata; Ramadevi, M. C.; Bhattacharya, Debbijoy

2018-05-01

By analysing the time series of RXTE/PCA data, the non-linear variabilities of compact sources have been repeatedly established. Depending on the variation in temporal classes, compact sources exhibit different non-linear features. Sometimes they show low correlation/fractal dimension, but in other classes or intervals of time they exhibit stochastic nature. This could be because the accretion flow around a compact object is a non-linear general relativistic system involving magnetohydrodynamics. However, the more conventional way of addressing a compact source is the analysis of its spectral state. Therefore, the question arises: What is the connection of non-linearity to the underlying spectral properties of the flow when the non-linear properties are related to the associated transport mechanisms describing the geometry of the flow? This work is aimed at addressing this question. Based on the connection between observed spectral and non-linear (time series) properties of two X-ray binaries: GRS 1915+105 and Sco X-1, we attempt to diagnose the underlying accretion modes of the sources in terms of known accretion classes, namely, Keplerian disc, slim disc, advection dominated accretion flow and general advective accretion flow. We explore the possible transition of the sources from one accretion mode to others with time. We further argue that the accretion rate must play an important role in transition between these modes.

The reports of thick discs' deaths are greatly exaggerated. Thick discs are NOT artefacts caused by diffuse scattered light

NASA Astrophysics Data System (ADS)

Comerón, S.; Salo, H.; Knapen, J. H.

2018-02-01

Recent studies have made the community aware of the importance of accounting for scattered light when examining low-surface-brightness galaxy features such as thick discs. In our past studies of the thick discs of edge-on galaxies in the Spitzer Survey of Stellar Structure in Galaxies - the S4G - we modelled the point spread function as a Gaussian. In this paper we re-examine our results using a revised point spread function model that accounts for extended wings out to more than 2\\farcm5. We study the 3.6 μm images of 141 edge-on galaxies from the S4G and its early-type galaxy extension. Thus, we more than double the samples examined in our past studies. We decompose the surface-brightness profiles of the galaxies perpendicular to their mid-planes assuming that discs are made of two stellar discs in hydrostatic equilibrium. We decompose the axial surface-brightness profiles of galaxies to model the central mass concentration - described by a Sérsic function - and the disc - described by a broken exponential disc seen edge-on. Our improved treatment fully confirms the ubiquitous occurrence of thick discs. The main difference between our current fits and those presented in our previous papers is that now the scattered light from the thin disc dominates the surface brightness at levels below μ 26 mag arcsec-2. We stress that those extended thin disc tails are not physical, but pure scattered light. This change, however, does not drastically affect any of our previously presented results: 1) Thick discs are nearly ubiquitous. They are not an artefact caused by scattered light as has been suggested elsewhere. 2) Thick discs have masses comparable to those of thin discs in low-mass galaxies - with circular velocities vc< 120 km s-1 - whereas they are typically less massive than the thin discs in high-mass galaxies. 3) Thick discs and central mass concentrations seem to have formed at the same epoch from a common material reservoir. 4) Approximately 50% of the up-bending breaks in face-on galaxies are caused by the superposition of a thin and a thick disc where the scale-length of the latter is the largest. Data of Figs. B.1 and C.1 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/610/A5

Pyrite discs in coal: evidence for fossilized bacterial colonies

USGS Publications Warehouse

Southam, G.; Donald, R.; Rostad, A.; Brock, C.

2001-01-01

Discs of pyrite from 1 to 3 mm in diameter and ∼100 μm thick were observed within fracture planes in coal from the Black Mesa coal deposit in northeastern Arizona. The pyrite discs were composed of aggregates of crystals, which suggested that sulfide mineral diagenesis had initiated at multiple nucleation sites and occurred prior to the compaction forces occurring during coal formation. Stable sulfur isotope analysis of the discs (δ34S = −31.7‰) supports a bacterial origin resulting from dissimilatory sulfate reduction. Fossilized bacteria on the disc surfaces (average = 27/100 μm2) appeared as halos when viewed using reflected light microscopy, but were lenticular by scanning electron microscopy, each microfossil being 2–3 μm in length. A fossilized bacterial colony (pyrite disc), 1 mm in diameter, would contain ∼2.1 × 107 microfossils. These microfossils were not observed on hydrothermal pyrite. Coating and in-filling of sulfate-reducing bacteria with iron disulfide during in vitro sulfide mineral diagenesis provide mechanisms to explain the preservation of the three-dimensional lenticular microfossils observed on the pyrite discs.

Intermediate mass black holes in AGN discs - I. Production and growth

NASA Astrophysics Data System (ADS)

McKernan, B.; Ford, K. E. S.; Lyra, W.; Perets, H. B.

2012-09-01

Here we propose a mechanism for efficiently growing intermediate mass black holes (IMBH) in discs around supermassive black holes. Stellar mass objects can efficiently agglomerate when facilitated by the gas disc. Stars, compact objects and binaries can migrate, accrete and merge within discs around supermassive black holes. While dynamical heating by cusp stars excites the velocity dispersion of nuclear cluster objects (NCOs) in the disc, gas in the disc damps NCO orbits. If gas damping dominates, NCOs remain in the disc with circularized orbits and large collision cross-sections. IMBH seeds can grow extremely rapidly by collisions with disc NCOs at low relative velocities, allowing for super-Eddington growth rates. Once an IMBH seed has cleared out its feeding zone of disc NCOs, growth of IMBH seeds can become dominated by gas accretion from the active galactic nucleus (AGN) disc. However, the IMBH can migrate in the disc and expand its feeding zone, permitting a super-Eddington accretion rate to continue. Growth of IMBH seeds via NCO collisions is enhanced by a pile-up of migrators. We highlight the remarkable parallel between the growth of IMBH in AGN discs with models of giant planet growth in protoplanetary discs. If an IMBH becomes massive enough it can open a gap in the AGN disc. IMBH migration in AGN discs may stall, allowing them to survive the end of the AGN phase and remain in galactic nuclei. Our proposed mechanisms should be more efficient at growing IMBH in AGN discs than the standard model of IMBH growth in stellar clusters. Dynamical heating of disc NCOs by cusp stars is transferred to the gas in an AGN disc helping to maintain the outer disc against gravitational instability. Model predictions, observational constraints and implications are discussed in a companion paper (Paper II).

75 FR 7648 - Agency Information Collection Activities: Emergency Request

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-22

..., recipients, and representative payees: Braille and Microsoft Word files (on data compact discs). Current...) Braille, or (5) Microsoft Word. This call did not require OMB clearance. However, there may be respondents...

Phase transformation synthesis of TiO2/CdS heterojunction film with high visible-light photoelectrochemical activity

NASA Astrophysics Data System (ADS)

Liu, Canjun; Yang, Yahui; Li, Jie; Chen, Shu

2018-06-01

CdS/TiO2 heterojunction film used as a photoanode has attracted much attention in the past few years due to its good visible light photocatalytic activity. However, CdS/TiO2 films prepared by conventional methods (successive ionic layer adsorption and reaction, chemical bath deposition and electrodeposition) show numerous grain boundaries in the CdS layer and an imperfect contact at the heterojunction interface. In this study, we designed a phase transformation method to fabricate CdS/TiO2 nanorod heterojunction films. The characterization results showed that the CdS layer with fewer grain boundaries was conformally coated on the TiO2 nanorod surface and the formation mechanism has been explained in this manuscript. Moreover, the prepared CdS/TiO2 films show a high photocatalytic activity and the photocurrent density is as high as 9.65 mA cm‑2 at 0.80 V versus RHE. It may be attributed to fewer grain boundaries and a compact heterojunction contact, which can effectively improve charge separation and transportation.

Gas dynamics in tidal dwarf galaxies: Disc formation at z = 0

NASA Astrophysics Data System (ADS)

Lelli, Federico; Duc, Pierre-Alain; Brinks, Elias; Bournaud, Frédéric; McGaugh, Stacy S.; Lisenfeld, Ute; Weilbacher, Peter M.; Boquien, Médéric; Revaz, Yves; Braine, Jonathan; Koribalski, Bärbel S.; Belles, Pierre-Emmanuel

2015-12-01

Tidal dwarf galaxies (TDGs) are recycled objects that form within the collisional debris of interacting and merging galaxies. They are expected to be devoid of non-baryonic dark matter, since they can only form from dissipative material ejected from the discs of the progenitor galaxies. We investigate the gas dynamics in a sample of six bona fide TDGs around three interacting and post-interacting systems: NGC 4694, NGC 5291, and NGC 7252 ("Atoms for Peace"). For NGC 4694 and NGC 5291, we analyse existing H I data from the Very Large Array (VLA), while for NGC 7252 we present new H I observations from the Jansky VLA, together with long-slit and integral-field optical spectroscopy. For all six TDGs, the H I emission can be described by rotating disc models. These H I discs, however, have undergone less than a full rotation since the time of the interaction/merger event, raising the question of whether they are in dynamical equilibrium. Assuming that these discs are in equilibrium, the inferred dynamical masses are consistent with the observed baryonic masses, implying that TDGs are devoid of dark matter. This puts constraints on putative "dark discs" (either baryonic or non-baryonic) in the progenitor galaxies. Moreover, TDGs seem to systematically deviate from the baryonic Tully-Fisher relation. These results provide a challenging test for alternative theories like MOND. Based on observations made with ESO telescopes at Paranal Observatory under programmes 65.O-0563, 67.B-0049, and 083.B-0647.Appendices are available in electronic form at http://www.aanda.orgThe reduced data cubes are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/584/A113

76 FR 24556 - Intermediary Lending Pilot (ILP) Program

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-02

... of materials. Each application must be submitted in two different formats: (1) Hard copy with original signatures, and (2) in Word or PDF format on a standard Compact Disc. See the instructions in the...

Compaction Behavior of Granular Materials

NASA Astrophysics Data System (ADS)

Endicott, Mark R.; Kenkre, V. M.; Glass, S. Jill; Hurd, Alan J.

1996-03-01

We report the results of our recent study of compaction of granular materials. A theoretical model is developed for the description of the compaction of granular materials exemplified by granulated ceramic powders. Its predictions are compared to observations of uniaxial compaction tests of ceramic granules of PMN-PT, spray dried alumina and rutile. The theoretical model employs a volume-based statistical mechanics treatment and an activation analogy. Results of a computer simulation of random packing of discs in two dimensions are also reported. The effect of type of particle size distribution and other parameters of that distribution on the calculated quantities are discussed. We examine the implications of the results of the simulation for the theoretical model.

H I absorption in nearby compact radio galaxies

NASA Astrophysics Data System (ADS)

Glowacki, M.; Allison, J. R.; Sadler, E. M.; Moss, V. A.; Curran, S. J.; Musaeva, A.; Deng, C.; Parry, R.; Sligo, M. C.

2017-05-01

H I absorption studies yield information on both active galactic nucleus (AGN) feeding and feedback processes. This AGN activity interacts with the neutral gas in compact radio sources, which are believed to represent the young or recently re-triggered AGN population. We present the results of a survey for H I absorption in a sample of 66 compact radio sources at 0.040 < z < 0.096 with the Australia Telescope Compact Array. In total, we obtained seven detections, five of which are new, with a large range of peak optical depths (3-87 per cent). Of the detections, 71 per cent exhibit asymmetric, broad (ΔvFWHM > 100 km s-1) features, indicative of disturbed gas kinematics. Such broad, shallow and offset features are also found within low-excitation radio galaxies which is attributed to disturbed circumnuclear gas, consistent with early-type galaxies typically devoid of a gas-rich disc. Comparing mid-infrared colours of our galaxies with H I detections indicates that narrow and deep absorption features are preferentially found in late-type and high-excitation radio galaxies in our sample. These features are attributed to gas in galactic discs. By combining XMM-Newton archival data with 21-cm data, we find support that absorbed X-ray sources may be good tracers of H I content within the host galaxy. This sample extends previous H I surveys in compact radio galaxies to lower radio luminosities and provides a basis for future work exploring the higher redshift universe.

Enormous disc of cool gas surrounding the nearby powerful radio galaxy NGC612 (PKS0131-36)

NASA Astrophysics Data System (ADS)

Emonts, B. H. C.; Morganti, R.; Oosterloo, T. A.; Holt, J.; Tadhunter, C. N.; van der Hulst, J. M.; Ojha, R.; Sadler, E. M.

2008-06-01

We present the detection of an enormous disc of cool neutral hydrogen (HI) gas surrounding the S0 galaxy NGC612, which hosts one of the nearest powerful radio sources (PKS0131-36). Using the Australia Telescope Compact Array, we detect MHI = 1.8 × 109Msolar of HI emission-line gas that is distributed in a 140-kpc wide disc-like structure along the optical disc and dust lane of NGC612. The bulk of the gas in the disc appears to be settled in regular rotation with a total velocity range of 850kms-1, although asymmetries in this disc indicate that perturbations are being exerted on part of the gas, possibly by a number of nearby companions. The HI disc in NGC612 suggests that the total mass enclosed by the system is Menc ~ 2.9 × 1012 sin-2 iMsolar, implying that this early-type galaxy contains a massive dark matter halo. We also discuss an earlier study by Holt et al. that revealed the presence of a prominent young stellar population at various locations throughout the disc of NGC612, indicating that this is a rare example of an extended radio source that is hosted by a galaxy with a large-scale star-forming disc. In addition, we map a faint HI bridge along a distance of 400kpc in between NGC612 and the gas-rich (MHI = 8.9 × 109Msolar) barred galaxy NGC619, indicating that likely an interaction between both systems occurred. From the unusual amounts of HI gas and young stars in this early-type galaxy, in combination with the detection of a faint optical shell and the system's high infrared luminosity, we argue that either ongoing or past galaxy interactions or a major merger event are a likely mechanism for the triggering of the radio source in NGC612. This paper is part of an ongoing study to map the large-scale neutral hydrogen properties of nearby radio galaxies and it presents the first example of large-scale HI detected around a powerful Fanaroff-Riley type II (FR-II) radio galaxy. The HI properties of the FR-II radio galaxy NGC612 are very similar to those found for low-power compact radio sources, but different from those of extended Fanaroff-Riley type I (FR-I) sources.

The Auriga Project: the properties and formation mechanisms of disc galaxies across cosmic time

NASA Astrophysics Data System (ADS)

Grand, Robert J. J.; Gómez, Facundo A.; Marinacci, Federico; Pakmor, Rüdiger; Springel, Volker; Campbell, David J. R.; Frenk, Carlos S.; Jenkins, Adrian; White, Simon D. M.

2017-05-01

We introduce a suite of 30 cosmological magneto-hydrodynamical zoom simulations of the formation of galaxies in isolated Milky Way mass dark haloes. These were carried out with the moving mesh code arepo, together with a comprehensive model for galaxy formation physics, including active galactic nuclei (AGN) feedback and magnetic fields, which produces realistic galaxy populations in large cosmological simulations. We demonstrate that our simulations reproduce a wide range of present-day observables, in particular, two-component disc-dominated galaxies with appropriate stellar masses, sizes, rotation curves, star formation rates and metallicities. We investigate the driving mechanisms that set present-day disc sizes/scalelengths, and find that they are related to the angular momentum of halo material. We show that the largest discs are produced by quiescent mergers that inspiral into the galaxy and deposit high-angular momentum material into the pre-existing disc, simultaneously increasing the spin of dark matter and gas in the halo. More violent mergers and strong AGN feedback play roles in limiting disc size by destroying pre-existing discs and by suppressing gas accretion on to the outer disc, respectively. The most important factor that leads to compact discs, however, is simply a low angular momentum for the halo. In these cases, AGN feedback plays an important role in limiting central star formation and the formation of a massive bulge.

Antifungal Susceptibility Testing in HIV/AIDS Patients: a Comparison Between Automated Machine and Manual Method.

PubMed

Nelwan, Erni J; Indrasanti, Evi; Sinto, Robert; Nurchaida, Farida; Sosrosumihardjo, Rustadi

2016-01-01

to evaluate the performance of Vitek2 compact machine (Biomerieux Inc. ver 04.02, France) in reference to manual methods for susceptibility test for Candida resistance among HIV/AIDS patients. a comparison study to evaluate Vitek2 compact machine (Biomerieux Inc. ver 04.02, France) in reference to manual methods for susceptibility test for Candida resistance among HIV/AIDS patient was done. Categorical agreement between manual disc diffusion and Vitek2 machine was calculated using predefined criteria. Time to susceptibility result for automated and manual methods were measured. there were 137 Candida isolates comprising eight Candida species with C.albicans and C. glabrata as the first (56.2%) and second (15.3%) most common species, respectively. For fluconazole drug, among the C. albicans, 2.6% was found resistant on manual disc diffusion methods and no resistant was determined by Vitek2 machine; whereas 100% C. krusei was identified as resistant on both methods. Resistant patterns for C. glabrata to fluconazole, voriconazole and amphotericin B were 52.4%, 23.8%, 23.8% vs. 9.5%, 9.5%, 4.8% respectively between manual diffusion disc methods and Vitek2 machine. Time to susceptibility result for automated methods compared to Vitex2 machine was shorter for all Candida species. there is a good categorical agreement between manual disc diffusion and Vitek2 machine, except for C. glabrata for measuring the antifungal resistant. Time to susceptibility result for automated methods is shorter for all Candida species.

Multimedia in 1992.

ERIC Educational Resources Information Center

Desmarais, Norman

1991-01-01

Reviews current developments in multimedia computing for both the business and consumer markets, including interactive multimedia players; compact disc-interactive (CD-I), including levels of audio quality, various video specifications and visual effects, and software; digital video interactive (DVI); and multimedia personal computers. (LRW)

Optical Disks.

ERIC Educational Resources Information Center

Gale, John C.; And Others

1985-01-01

This four-article section focuses on information storage capacity of the optical disk covering the information workstation (uses microcomputer, optical disk, compact disc to provide reference information, information content, work product support); use of laser videodisc technology for dissemination of agricultural information; encoding databases…

TEMPO Software Modifications for SEVER Evaluation

DTIC Science & Technology

2009-09-01

existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding...115 COMPACT DISC. TEMPO VERSION 3 AND ASSOCIATED DATA …..ENCLOSED ix LIST...Setup..........................................................46 Figure 16. TEMPO Version 3 Startup Dialog Box

Laserdisk Directory--Part 1.

ERIC Educational Resources Information Center

Connolly, Bruce, Comp.

1986-01-01

This first installment of four-part "Online/Database Laserdisk Directory" reports on aspects of laserdisks including: product name; product description; company name; conpatibility information; type of laserdisk (compact disc read-only-memory, videodisk); software used; interface with magnetic media capability; conditions of usage;…

Buying and Selling Laserbases.

ERIC Educational Resources Information Center

Desmarais, Norman

1986-01-01

Discusses factors that should be considered by buyers and producers of databases on CD-ROM (compact disc-read only memory). The advantages and disadvantages of CD-ROM are also discussed and compared with those of magnetic and print media, and market projections are provided. (CLB)

Transformations: Technology and the Music Industry.

ERIC Educational Resources Information Center

Peters, G. David

2001-01-01

Focuses on the companies and organizations of the Music Industry Conference (MIC). Addresses topics such as: changes in companies due to technology, audio compact discs, the music instrument digital interface (MIDI) , digital sound recording, and the MIC on-line music instruction programs offered. (CMK)

Electronic Document Supply Systems.

ERIC Educational Resources Information Center

Cawkell, A. E.

1991-01-01

Describes electronic document delivery systems used by libraries and document image processing systems used for business purposes. Topics discussed include technical specifications; analogue read-only laser videodiscs; compact discs and CD-ROM; WORM; facsimile; ADONIS (Article Delivery over Network Information System); DOCDEL; and systems at the…

Quality of ground water for selected municipal water supplies in Iowa, 1997-2002

USGS Publications Warehouse

Littin, Gregory R.

2004-01-01

The compact disc included with this report has information about water-quality properties and concentrations of dissolved solids, major ions, nutrients, trace elements, radionuclides, total organic carbon, pesticides, and synthetic organic compounds for water years 1997 through 2002.

SITE TECHNOLOGY PROFILES - 11TH EDITION, COMPACT DISC

EPA Science Inventory

The Superfund Innovative Technology Evaluation (SITE) Program, now in its eleventh year is an integral part of EPA's research into alternative cleanup methods for hazardous waste sites around the nation. The SITE Program was created to encourage the development and routine use o...

Radiative transfer modelling of W33A MM1: 3-D structure and dynamics of a complex massive star forming region

NASA Astrophysics Data System (ADS)

Izquierdo, Andrés F.; Galván-Madrid, Roberto; Maud, Luke T.; Hoare, Melvin G.; Johnston, Katharine G.; Keto, Eric R.; Zhang, Qizhou; de Wit, Willem-Jan

2018-05-01

We present a composite model and radiative transfer simulations of the massive star forming core W33A MM1. The model was tailored to reproduce the complex features observed with ALMA at ≈0.2 arcsec resolution in CH3CN and dust emission. The MM1 core is fragmented into six compact sources coexisting within ˜1000 au. In our models, three of these compact sources are better represented as disc-envelope systems around a central (proto)star, two as envelopes with a central object, and one as a pure envelope. The model of the most prominent object (Main) contains the most massive (proto)star (M⋆ ≈ 7 M⊙) and disc+envelope (Mgas ≈ 0.4 M⊙), and is the most luminous (LMain ˜ 104 L⊙). The model discs are small (a few hundred au) for all sources. The composite model shows that the elongated spiral-like feature converging to the MM1 core can be convincingly interpreted as a filamentary accretion flow that feeds the rising stellar system. The kinematics of this filament is reproduced by a parabolic trajectory with focus at the center of mass of the region. Radial collapse and fragmentation within this filament, as well as smaller filamentary flows between pairs of sources are proposed to exist. Our modelling supports an interpretation where what was once considered as a single massive star with a ˜103 au disc and envelope, is instead a forming stellar association which appears to be virialized and to form several low-mass stars per high-mass object.

New Styles, New Technologies, New Possibilities in Jazz.

ERIC Educational Resources Information Center

Kuzmich, John, Jr.

1989-01-01

Focuses on the growth of jazz-related ensembles and jazz education. Covers trends that parallel technological developments including electronic keyboards, Musical Instrument Digital Interface (MIDI) systems, the computer, computer assisted instruction, interactive video, and the compact disc. Urges teachers to update their knowledge and experience…

How Community Colleges Can Capitalize on Changes in Information Services.

ERIC Educational Resources Information Center

Nourse, Jimmie Anne; Widman, Rudy

1991-01-01

Urges community college librarians to become leaders in library instruction by developing aggressive teaching programs using high-technology information resources, such as compact disc read-only-memory (CD-ROM), telecommunications, and on-line databases. Discusses training, hardware, software, and funding issues. (DMM)

Central Compact Objects: some of them could be spinning up?

NASA Astrophysics Data System (ADS)

Benli, O.; Ertan, Ü.

2018-05-01

Among confirmed central compact objects (CCOs), only three sources have measured period and period derivatives. We have investigated possible evolutionary paths of these three CCOs in the fallback disc model. The model can account for the individual X-ray luminosities and rotational properties of the sources consistently with their estimated supernova ages. For these sources, reasonable model curves can be obtained with dipole field strengths ˜ a few × 109 G on the surface of the star. The model curves indicate that these CCOs were in the spin-up state in the early phase of evolution. The spin-down starts, while accretion is going on, at a time t ˜ 103 - 104 yr depending on the current accretion rate, period and the magnetic dipole moment of the star. This implies that some of the CCOs with relatively long periods, weak dipole fields and high X-ray luminosities could be strong candidates to show spin-up behavior if they indeed evolve with fallback discs.

Lunar-forming impacts: processes and alternatives

PubMed Central

Canup, R. M.

2014-01-01

The formation of a protolunar disc by a giant impact with the early Earth is discussed, focusing on two classes of impacts: (i) canonical impacts, in which a Mars-sized impactor produces a planet–disc system whose angular momentum is comparable to that in the current Earth and Moon, and (ii) high-angular-momentum impacts, which produce a system whose angular momentum is approximately a factor of 2 larger than that in the current Earth and Moon. In (i), the disc originates primarily from impactor-derived material and thus is expected to have an initial composition distinct from that of the Earth's mantle. In (ii), a hotter, more compact initial disc is produced with a silicate composition that can be nearly identical to that of the silicate Earth. Both scenarios require subsequent processes for consistency with the current Earth and Moon: disc–planet compositional equilibration in the case of (i), or large-scale angular momentum loss during capture of the newly formed Moon into the evection resonance with the Sun in the case of (ii). PMID:25114302

The formation of co-orbital planets and their resulting transit signatures

NASA Astrophysics Data System (ADS)

Granados Contreras, Agueda Paula; Boley, Aaron

2018-04-01

Systems with Tightly-packed Inner Planets (STIPs) are metastable, exhibiting sudden transitions to an unstable state that can potentially lead to planet consolidation. When these systems are embedded in a gaseous disc, planet-disc interactions can significantly reduce the frequency of instabilities, and if they do occur, disc torques alter the dynamical outcomes. We ran a suite of N-body simulations of synthetic 6-planet STIPs using an independent implementation of IAS15 that includes a prescription for gaseous tidal damping. The algorithm is based on the results of disc simulations that self-consistently evolve gas and planets. Even for very compact configurations, the STIPS are resistant to instability when gas is present. However, instability can still occur, and in some cases, the combination of system instability and gaseous damping leads to the formation of co-orbiting planets that are stable even when gas damping is removed. While rare, such systems should be detectable in transit surveys, although the dynamics of the system can make the transit signature difficult to identify.

EPA EXPOSURE MODELS LIBRARY AND INTEGRATED MODEL EVALUATION SYSTEM

EPA Science Inventory

The third edition of the U.S. Environmental Protection Agencys (EPA) EML/IMES (Exposure Models Library and Integrated Model Evaluation System) on CD-ROM is now available. The purpose of the disc is to provide a compact and efficient means to distribute exposure models, documentat...

Interactive Educational Multimedia: Coping with the Need for Increasing Data Storage.

ERIC Educational Resources Information Center

Malhotra, Yogesh; Erickson, Ranel E.

1994-01-01

Discusses the storage requirements for data forms used in interactive multimedia education and presently available storage devices. Highlights include characteristics of educational multimedia; factors determining data storage requirements; storage devices for video and audio needs; laserdiscs and videodiscs; compact discs; magneto-optical drives;…

Teaching with Technology: Literature and Software.

ERIC Educational Resources Information Center

Allen, Denise

1994-01-01

Reviews five computer programs and compact disc-read only memory (CD-ROM) products designed to improve students' reading and problem-solving skills: (1) "Reading Realities" (Teacher Support Software); (2) "Kid Rhymes" (Creative Pursuits); (3) "First-Start Biographies" (Troll Associates); (4) "My Silly CD of ABCs" (Discis Classroom Editions); and…

Robert E. Lee as Operational Artist During the American Civil War

DTIC Science & Technology

2010-04-21

the ability to master operational mt and design is invaluable. The current operational environment in which our nation is involved requires us to be...of Antietam, ed. Stephen W. Sears. VoL Compact Disc. Ashland, OR: Blackstone Audiobooks. ---.2003. Gettysburg. Boston, MA: Houghton Mifflin

Warps and waves in the stellar discs of the Auriga cosmological simulations

NASA Astrophysics Data System (ADS)

Gómez, Facundo A.; White, Simon D. M.; Grand, Robert J. J.; Marinacci, Federico; Springel, Volker; Pakmor, Rüdiger

2017-03-01

Recent studies have revealed an oscillating asymmetry in the vertical structure of the Milky Way's disc. Here, we analyse 16 high-resolution, fully cosmological simulations of the evolution of individual Milky Way-sized galaxies, carried out with the magnetohydrodynamic code AREPO. At redshift zero, about 70 per cent of our galactic discs show strong vertical patterns, with amplitudes that can exceed 2 kpc. Half of these are typical 'integral sign' warps. The rest are oscillations similar to those observed in the Milky Way. Such structures are thus expected to be common. The associated mean vertical motions can be as large as 30 km s-1. Cold disc gas typically follows the vertical patterns seen in the stars. These perturbations have a variety of causes: close encounters with satellites, distant fly-bys of massive objects, accretion of misaligned cold gas from halo infall or from mergers. Tidally induced vertical patterns can be identified in both young and old stellar populations, whereas those originating from cold gas accretion are seen mainly in the younger populations. Galaxies with regular or at most weakly perturbed discs are usually, but not always, free from recent interactions with massive companions, although we have one case where an equilibrium compact disc reforms after a merger.

On the Radio Detectability of Circumplanetary Discs

NASA Astrophysics Data System (ADS)

Zhu, Zhaohuan; Andrews, Sean M.; Isella, Andrea

2018-06-01

Discs around young planets, so-called circumplanetary discs (CPDs), are essential for planet growth, satellite formation, and planet detection. We study the millimetre and centimetre emission from accreting CPDs by using the simple α disc model. We find that it is easier to detect CPDs at shorter radio wavelengths (e.g. λ ≲ 1 mm). For example, if the system is 140 pc away from us, deep observations (e.g. 5 hours) at ALMA Band 7 (0.87 mm) are sensitive to as small as 0.03 lunar mass of dust in CPDs. If the CPD is around a Jupiter mass planet 20 AU away from the host star and has a viscosity parameter α ≲ 0.001, ALMA can detect this disc when it accretes faster than 10-10M⊙/yr. ALMA can also detect the "minimum mass sub-nebulae" disc if such a disc exists around a young planet in YSOs. However, to distinguish the embedded compact CPD from the circumstellar disc material, we should observe circumstellar discs with large gaps/cavities using the highest resolution possible. We also calculate the CPD fluxes at VLA bands, and discuss the possibility of detecting radio emission from jets/winds launched in CPDs. Finally we argue that, if the radial drift of dust particles is considered, the drifting timescale for millimetre dust in CPDs can be extremely short. It only takes 102-103 years for CPDs to lose millimetre dust. Thus, for CPDs to be detectable at radio wavelengths, mm-sized dust in CPDs needs to be replenished continuously, or the disc has a significant fraction of micron-sized dust or a high gas surface density so that the particle drifting timescale is long, or the radial drift is prevented by other means (e.g. pressure traps).

CD-ROM technology at the EROS data center

USGS Publications Warehouse

Madigan, Michael E.; Weinheimer, Mary C.

1993-01-01

The vast amount of digital spatial data often required by a single user has created a demand for media alternatives to 1/2" magnetic tape. One such medium that has been recently adopted at the U.S. Geological Survey's EROS Data Center is the compact disc (CD). CD's are a versatile, dynamic, and low-cost method for providing a variety of data on a single media device and are compatible with various computer platforms. CD drives are available for personal computers, UNIX workstations, and mainframe systems, either directly connected, or through a network. This medium furnishes a quick method of reproducing and distributing large amounts of data on a single CD. Several data sets are already available on CD's, including collections of historical Landsat multispectral scanner data and biweekly composites of Advanced Very High Resolution Radiometer data for the conterminous United States. The EROS Data Center intends to provide even more data sets on CD's. Plans include specific data sets on a customized disc to fulfill individual requests, and mass production of unique data sets for large-scale distribution. Requests for a single compact disc-read only memory (CD-ROM) containing a large volume of data either for archiving or for one-time distribution can be addressed with a CD-write once (CD-WO) unit. Mass production and large-scale distribution will require CD-ROM replication and mastering.

Total analysis systems with Thermochromic Etching Discs technology.

PubMed

Avella-Oliver, Miquel; Morais, Sergi; Carrascosa, Javier; Puchades, Rosa; Maquieira, Ángel

2014-12-16

A new analytical system based on Thermochromic Etching Discs (TED) technology is presented. TED comprises a number of attractive features such as track independency, selective irradiation, a high power laser, and the capability to create useful assay platforms. The analytical versatility of this tool opens up a wide range of possibilities to design new compact disc-based total analysis systems applicable in chemistry and life sciences. In this paper, TED analytical implementation is described and discussed, and their analytical potential is supported by several applications. Microarray immunoassay, immunofiltration assay, solution measurement, and cell culture approaches are herein addressed in order to demonstrate the practical capacity of this system. The analytical usefulness of TED technology is herein demonstrated, describing how to exploit this tool for developing truly integrated analytical systems that provide solutions within the point of care framework.

High Efficiency Photovoltaic Devices Fabricated from Self-Assemble Block Insulating-Conducting Copolymer Containing Semiconducting Nanoparticles

DTIC Science & Technology

2005-12-14

71.3° TESDT ɝ° 45.3° 59.5° 67.2° 75.0° The amount of D-A linkers anchored on TiO2 nanoparticles was determined by thermogravimetric analysis ...e.g. lamellae, cylinders and spheres of copolymers were fabricated. Semiconducting nanoparticles of cadmium sulfide ( CdS ) was incorporated into PPP...water contact angle measurement, thermogravimetric analysis , and XPS spectra, we can presume that compact SAMs were formed on the surface of TiO2

College Libraries and Resource Sharing: Testing a Compact Disc Union Catalog.

ERIC Educational Resources Information Center

Townley, Charles T.

1992-01-01

Presents results of an evaluation of C.D. Cat, a CD-ROM union catalog developed by the Associated College Libraries of Central Pennsylvania consortium. Outcomes are reported in the areas of bibliographic quality, user evaluation, public relations strategies, bibliographic instruction, and guidelines for continuing operations. Recommendations are…

Inquiry with Laser Printer Diffraction Gratings

ERIC Educational Resources Information Center

Van Hook, Stephen J.

2007-01-01

The pages of "The Physics Teacher" have featured several clever designs for homemade diffraction gratings using a variety of materials--cloth, lithographic film, wire, compact discs, parts of aerosol spray cans, and pseudoliquids and pseudosolids. A different and inexpensive method I use to make low-resolution diffraction gratings takes advantage…

Engaging New Software.

ERIC Educational Resources Information Center

Allen, Denise

1994-01-01

Reviews three educational computer software products: (1) a compact disc-read only memory (CD-ROM) bundle of five mathematics programs from the Apple Education Series; (2) "Sammy's Science House," with science activities for preschool through second grade (Edmark); and (3) "The Cat Came Back," an interactive CD-ROM game designed to build language…

CD ROM (Compact Disc Read Only Memory): Potential Uses at Air University.

DTIC Science & Technology

1988-04-01

5 Library Science .................................... 6 Medicine........................................... 7 Law...publishing, business, education, library science , medicine, law, weather, cartography, and navigation will be discussed. Finally, Chapter One will conclude...substantial impact in the following disciplines: publishing, business, education, library science , medicine, law, weather and cartography. This portion of 4

Chinese Language Video Clips. [CD-ROM].

ERIC Educational Resources Information Center

Fleming, Stephen; Hipley, David; Ning, Cynthia

This compact disc includes video clips covering six topics for the learner of Chinese: personal information, commercial transactions, travel and leisure, health and sports, food and school. Filmed on location in Beijing, these naturalistic video clips consist mainly of unrehearsed interviews of ordinary people. The learner is lead through a series…

Low-Tech High-Tech.

ERIC Educational Resources Information Center

Hart, Tom

1997-01-01

Outlines how Compact Disc-interactive (CD-i)--software that looks like a CD-ROM but operates independently using a television set--can be used in elementary, secondary, and vocational education. Discusses the cost effectiveness of CD-i and compares costs and operational issues with CD-ROM. Describes special features of one CD-i program,…

Brainworks: Birth to Kindergarten.

ERIC Educational Resources Information Center

Goss, Joyce L.; Fisicaro, Maria E.

This book is to be used with a multimedia presentation that is available on compact disc. The book and multimedia presentation are designed to help parents and childcare providers understand the concept of early exposure and exploration that is followed by increased development of synaptic connections and ultimately prepares children to handle…

CD-ROM versus Online.

ERIC Educational Resources Information Center

Wiedemer, John David; Boelio, David B.

1995-01-01

Compares compact discs (CD-ROMs) and online services in terms of cost of information delivery; system advantages and disadvantages; future possibilities; and role in the National Information Infrastructure. Analysis reveals that CD-ROMs have the lowest information delivery cost and are endorsed by the marketplace as a cost-effective way to deliver…

Photo CD: A Macintosh Primer.

ERIC Educational Resources Information Center

Bennett, Hugh

1993-01-01

Describes Photo CD, a procedure developed by Eastman Kodak for storing high-resolution 35mm film images on compact discs, and explains Macintosh microcomputer-based hardware and software that can be used with it. Software for viewing as well as editing and altering images is described, and future products are discussed. (four references) (LRW)

DIGITAL GEOLOGIC MAP OF SHERMAN QUADRANGLE, NORTH CENTRAL TEXAS (CD-ROM)

EPA Science Inventory

This compact disc contains digital data sets of the surficial geology and geologic faults for the 1:250,000-scale Sherman quadrangle, North Central Texas, and can be used to make geologic maps, and determine approximate areas and locations of various geologic units. The source d...

CD-I and Full Motion Video.

ERIC Educational Resources Information Center

Chen, Ching-chih

1991-01-01

Describes compact disc interactive (CD-I) as a multimedia home entertainment system that combines audio, visual, text, graphic, and interactive capabilities. Full-screen video and full-motion video (FMV) are explained, hardware for FMV decoding is described, software is briefly discussed, and CD-I titles planned for future production are listed.…

Sparkling Science Programs.

ERIC Educational Resources Information Center

Allen, Denise

1995-01-01

Reviews five compact disc-read only memory (CD-ROM) products and one video series that focus on science projects: (1) "Body Park" (Virtual Entertainment); (2) "The Magic School Bus Explores the Solar System" (Microsoft); (3) "The Magic School Bus Explores the Human Body" (Microsoft); (4) "Science Curriculum Assistance Program" (Demco); and (5)…

Selective tuning of the self-assembly and gelation of a hydrophilic poloxamine by cyclodextrins.

PubMed

González-Gaitano, Gustavo; da Silva, Marcelo A; Radulescu, Aurel; Dreiss, Cécile A

2015-05-26

Complexes formed between cyclodextrins (CDs) and polymers - pseudopolyrotaxanes (PPRs) - are the starting point of a multitude of supramolecular structures, which are proposed for a wide range of biomedical and technological applications. In this work, we investigate the complexation of a range of cyclodextrins with Tetronic T1307, a four-arm block copolymer of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) with a pH-responsive central ethylene diamine spacer, and its impact on micellization and the sol-gel transition. At low concentrations, small-angle neutron scattering (SANS) combined with dynamic light scattering (DLS) measurements show the presence of spherical micelles with a highly hydrated shell and a dehydrated core. Increasing the temperature leads to more compact micelles and larger aggregation numbers, whereas acidic conditions induce a shrinking of the micelles, with fewer unimers per micelle and a more hydrated corona. At high concentrations, T1307 undergoes a sol-gel transition, which is suppressed at pH below the pKa,1 (4.6). SANS data analysis reveals that the gels result from a random packing of the micelles, which have an increasing aggregation number and increasingly dehydrated shell and hydrated core with the temperature. Native CDs (α, β, γ-CD) can complex T1307, resulting in the precipitation of a PPR. Instead, modified CDs compete with micellization to an extent that is critically dependent on the nature of the substitution. (1)H and ROESY NMR combined with SANS demonstrate that dimethylated β-CD can thread onto the polymer, preferentially binding to the PO units, thus hindering self-aggregation by solubilizing the hydrophobic block. The various CDs are able to modulate the onset of gelation and the extent of the gel phase, and the effect correlates with the ability of the CDs to disrupt the micelles, with the exception of a sulfated sodium salt of β-CD, which, while not affecting the CMT, is able to fully suppress the gel phase.

The co-existence of hot and cold gas in debris discs

NASA Astrophysics Data System (ADS)

Rebollido, I.; Eiroa, C.; Montesinos, B.; Maldonado, J.; Villaver, E.; Absil, O.; Bayo, A.; Canovas, H.; Carmona, A.; Chen, Ch.; Ertel, S.; Garufi, A.; Henning, Th.; Iglesias, D. P.; Launhardt, R.; Liseau, R.; Meeus, G.; Moór, A.; Mora, A.; Olofsson, J.; Rauw, G.; Riviere-Marichalar, P.

2018-06-01

Context. Debris discs have often been described as gas-poor discs as the gas-to-dust ratio is expected to be considerably lower than in primordial, protoplanetary discs. However, recent observations have confirmed the presence of a non-negligible amount of cold gas in the circumstellar (CS) debris discs around young main-sequence stars. This cold gas has been suggested to be related to the outgassing of planetesimals and cometary-like objects. Aims: The goal of this paper is to investigate the presence of hot gas in the immediate surroundings of the cold-gas-bearing debris-disc central stars. Methods: High-resolution optical spectra of all currently known cold-gas-bearing debris-disc systems, with the exception of β Pic and Fomalhaut, have been obtained from La Palma (Spain), La Silla (Chile), and La Luz (Mexico) observatories. To verify the presence of hot gas around the sample of stars, we have analysed the Ca II H&K and the Na I D lines searching for non-photospheric absorptions of CS origin, usually attributed to cometary-like activity. Results: Narrow, stable Ca II and/or Na I absorption features have been detected superimposed to the photospheric lines in 10 out of the 15 observed cold-gas-bearing debris-disc stars. Features are found at the radial velocity of the stars, or slightly blue- or red-shifted, and/or at the velocity of the local interstellar medium (ISM). Some stars also present transient variable events or absorptions extended towards red wavelengths (red wings). These are the first detections of such Ca II features in 7 out of the 15 observed stars. Although an ISM origin cannot categorically be excluded, the results suggest that the stable and variable absorptions arise from relatively hot gas located in the CS close-in environment of the stars. This hot gas is detected in at least 80%, of edge-on cold-gas-bearing debris discs, while in only 10% of the discs seen close to face-on. We interpret this result as a geometrical effect, and suggest that the non-detection of hot gas absorptions in some face-on systems is due to the disc inclination and likely not to the absence of the hot-gas component. This gas is likely released in physical processes related in some way to the evaporation of exocomets, evaporation of dust grains, or grain-grain collisions close to the central star. The reduced spectra are only available at the CDS (ascii files) and at the FEROS archive (FITS files) via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/614/A3

Porcelain thickness and cement shade effects on the colour and translucency of porcelain veneering materials.

PubMed

Kürklü, Duygu; Azer, Shereen S; Yilmaz, Burak; Johnston, William M

2013-11-01

Purposes of this in vitro study include evaluating colour changes in combinations of feldspathic porcelain and cement resulting from different thicknesses of porcelain and different shades of composite luting agent, and evaluating relative translucency parameter (RTP) values. Porcelain discs of shade A1 at nominal thicknesses of 0.5 and 1.0mm were bonded to cements of three shades in a factorial design. Colours were calculated for CIE D65 Illuminant and Standard Human Observer on black, grey and white backings. A colour difference (CD) was calculated of each possible pair of different porcelain thickness values for the same cement shade and each possible pair of different cement shades for the same porcelain thickness. RTP was analyzed by ANOVA and selected pairwise comparisons. All mean CDs studied were perceptible and most were at or greater than the clinical acceptability threshold, with the notable exception that the mean CDs and their confidence limits were below the clinical acceptability threshold for a change in porcelain thickness when utilizing the Clear cement shade. Variation in the shade of the resin luting cement will result in CDs which are near or beyond clinical acceptability. A decrease in porcelain thickness did significantly increase RTP when bonded to the resin cement shades studied. Changes in porcelain thickness or cement shade may adversely affect basic aesthetic properties of these materials. Development of methods for analyzing aesthetic effects over greater ranges of thickness for these materials would improve the prognosis for using these materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of ceramic thickness and cement shade on the final shade after bonding using the 3D master system: a laboratory study.

PubMed

Montero, Javier; Gómez-Polo, Cristina

2016-06-01

The final color of a ceramic restoration is influenced by both the ceramic thickness and the cement shade. This study aims to evaluate the color stability according to the 3D Master System of e.max ceramic discs after bonding with different shades of luting agents. A total of 120 e.max.Press 2M1 HT ceramic discs (60 discs of 1-mm thick and 60 discs of 0.5 mm thick) and three different values of Variolink Veneer cement were used (-3, 0, +3) for the cementation process. An Easyshade compact device was used to measure color shade tabs, according to the 3D Master System, on the discs both before and after the cementation protocols. Bivariate and multivariate analyses were carried out with the spss v.21. After bonding with the different luting agents, only 30% remained as 2M1: specifically, 22% of the thinner discs and 37.3% of the thicker discs. In general, the effect of bonding increased the value and the chroma of the shade to a significant extent. Regression analyses revealed that the most significant predictor for all color parameters was cement shade, the thinner disc group bonded with -3 cement being the most unstable subgroup. According to the 3D Master System, the shade of the luting agent was the main predictor of the final color. However, the final color seems to be somewhat unpredictable, at least according to the modulating factors evaluated in the present study.

Investigation of surface porosity measurements and compaction pressure as means to ensure consistent contact angle determinations.

PubMed

Holm, René; Borkenfelt, Simon; Allesø, Morten; Andersen, Jens Enevold Thaulov; Beato, Stefania; Holm, Per

2016-02-10

Compounds wettability is critical for a number of central processes including disintegration, dispersion, solubilisation and dissolution. It is therefore an important optimisation parameter both in drug discovery but also as guidance for formulation selection and optimisation. Wettability for a compound is determined by its contact angle to a liquid, which in the present study was measured using the sessile drop method applied to a disc compact of the compound. Precise determination of the contact angle is important should it be used to either rank compounds or selected excipients to e.g. increase the wetting from a solid dosage form. Since surface roughness of the compact has been suggested to influence the measurement this study investigated if the surface quality, in terms of surface porosity, had an influence on the measured contact angle. A correlation to surface porosity was observed, however for six out of seven compounds similar results were obtained by applying a standard pressure (866 MPa) to the discs in their preparation. The data presented in the present work therefore suggest that a constant high pressure should be sufficient for most compounds when determining the contact angle. Only for special cases where compounds have poor compressibility would there be a need for a surface-quality-control step before the contact angle determination. Copyright © 2015 Elsevier B.V. All rights reserved.

The Absolute Abundance of Iron in the Solar Corona.

PubMed

White; Thomas; Brosius; Kundu

2000-05-10

We present a measurement of the abundance of Fe relative to H in the solar corona using a technique that differs from previous spectroscopic and solar wind measurements. Our method combines EUV line data from the Coronal Diagnostic Spectrometer (CDS) on the Solar and Heliospheric Observatory with thermal bremsstrahlung radio data from the VLA. The coronal Fe abundance is derived by equating the thermal bremsstrahlung radio emission calculated from the EUV Fe line data to that observed with the VLA, treating the Fe/H abundance as the sole unknown. We apply this technique to a compact cool active region and find Fe&solm0;H=1.56x10-4, or about 4 times its value in the solar photosphere. Uncertainties in the CDS radiometric calibration, the VLA intensity measurements, the atomic parameters, and the assumptions made in the spectral analysis yield net uncertainties of approximately 20%. This result implies that low first ionization potential elements such as Fe are enhanced in the solar corona relative to photospheric values.

Metastable alloy materials produced by solid state reaction of compacted, mechanically deformed mixtures

DOEpatents

Atzmon, M.; Johnson, W.L.; Verhoeven, J.D.

1987-02-03

Bulk metastable, amorphous or fine crystalline alloy materials are produced by reacting cold-worked, mechanically deformed filamentary precursors such as metal powder mixtures or intercalated metal foils. Cold-working consolidates the metals, increases the interfacial area, lowers the free energy for reaction, and reduces at least one characteristic dimension of the metals. For example, the grains of powder or the sheets of foil are clad in a container to form a disc. The disc is cold-rolled between the nip of rollers to form a flattened disc. The grains are further elongated by further rolling to form a very thin sheet of a lamellar filamentary structure containing filaments having a thickness of less than 0.01 microns. Thus, diffusion distance and time for reaction are substantially reduced when the flattened foil is thermally treated in oven to form a composite sheet containing metastable material dispersed in unreacted polycrystalline material. 4 figs.

Technology and Interactive Multimedia. Identifying Emerging Issues and Trends in Technology for Special Education.

ERIC Educational Resources Information Center

Ashton, Ray

As part of a 3-year study to identify emerging issues and trends in technology for special education, this paper addresses the role of interactive multimedia, especially the digital, optical compact disc technologies, in providing instructional services to special education students. An overview identifies technological and economic trends,…

Microsoft Producer: A Software Tool for Creating Multimedia PowerPoint[R] Presentations

ERIC Educational Resources Information Center

Leffingwell, Thad R.; Thomas, David G.; Elliott, William H.

2007-01-01

Microsoft[R] Producer[R] is a powerful yet user-friendly PowerPoint companion tool for creating on-demand multimedia presentations. Instructors can easily distribute these presentations via compact disc or streaming media over the Internet. We describe the features of the software, system requirements, and other required hardware. We also describe…

A "Musical Pathway" for Spatially Disoriented Blind Residents of a Skilled Nursing Facility.

ERIC Educational Resources Information Center

Uslan, M. M.; And Others

1988-01-01

The "Auditory Directional System" designed to help blind persons get to interior destinations in an institutional setting, uses a compact disc player, a network of speakers, infrared "people" detection equipment, and a computer controlled speaker-sequencing system. After initial destination selection, musical cues are activated as the person…

Enhancing Social Capital in Children via School-Based Community Cultural Development Projects: A Pilot Study

ERIC Educational Resources Information Center

Buys, Laurie; Miller, Evonne

2009-01-01

This exploratory pilot study investigates the extent to which participating in a community cultural development (CCD) initiative builds social capital among children. An independent youth arts organisation implemented two cultural activities, developing a compact disc of original music and designing mosaic artworks for a library courtyard, in two…

New Optical Card for Sneaker’s Network in Place of Electronic Clinical Record

NASA Astrophysics Data System (ADS)

Goto, Kenya; Satsukawa, Takatoshi; Chiba, Seisho; Ohmori, Takaaki

2006-02-01

In order to solve problems in electronic medical records, a new optical card of the digital versatile disk (DVD) type with higher capacity and lower cost than conventional compact disc recording (CD-R)-type cards has been developed, which is thinner, stronger and wearable like a credit card.

Houghton Mifflin Reading[c]. What Works Clearinghouse Intervention Report

ERIC Educational Resources Information Center

What Works Clearinghouse, 2008

2008-01-01

The "Houghton Mifflin Reading"[c] system is a reading program for instruction in grades K-6. It uses Big Books (authentic literature), anthologies, Read Alouds, and audio compact discs to provide step-by-step instruction in reading. According to the developer's website, "Houghton Mifflin Reading"[c] was developed based on the findings of the…

Houghton Mifflin Reading©. What Works Clearinghouse Intervention Report

ERIC Educational Resources Information Center

What Works Clearinghouse, 2015

2015-01-01

"Houghton Mifflin Reading"© is a reading program designed for grades K-6. The program provides step-by-step instruction in reading using Big Books (fiction and nonfiction literature), anthologies, Read Aloud books, and audio compact discs. The product is designed to be used as a full-year curriculum program with instruction on developing…

Two-Dimensional Light Diffraction from an EPROM Chip

ERIC Educational Resources Information Center

Ekkens, Tom

2018-01-01

In introductory physics classes, a laser pointer and a compact disc are all the items required to illustrate diffraction of light in a single dimension. If a two-dimensional diffraction pattern is desired, double axis diffraction grating material is available or a CCD sensor can be extracted from an unused electronics device. This article presents…

Reflections on CD-ROM: Bridging the Gap between Technology and Purpose.

ERIC Educational Resources Information Center

Saviers, Shannon Smith

1987-01-01

Provides a technological overview of CD-ROM (Compact Disc-Read Only Memory), an optically-based medium for data storage offering large storage capacity, computer-based delivery system, read-only medium, and economic mass production. CD-ROM database attributes appropriate for information delivery are also reviewed, including large database size,…

The CD-ROM Services of SilverPlatter Information, Inc.

ERIC Educational Resources Information Center

Allen, Robert J.

1985-01-01

The SilverPlatter system is a complete, stand-alone system, consisting of an IBM (or compatible) personal computer, compact disc with read-only memory (CD-ROM) drive, software, and one or more databases. Large databases (e.g., ERIC, PsycLIT) will soon be available on the system for "local" installation in schools, libraries, and…

76 FR 77510 - Applications for New Awards; Small Business Innovation Research Program (SBIR)-Phase I

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-13

..., including projects leading to the manufacture of such items as artificial intelligence or information... obtain a copy of the application package in an accessible format (e.g., braille, large print, audiotape...., braille, large print, audiotape, or compact disc) by contacting the Grants and Contracts Services Team, U...

Deep Fun and the Theater of Games: An Interview with Bernie Dekoven

ERIC Educational Resources Information Center

American Journal of Play, 2015

2015-01-01

Bernie DeKoven is both a play theorist and a play practitioner. He is the author of "The Well-Played Game" (reissued in 2013 by MIT Press) as well as "Junkyard Sports," "Power Meetings," and "Connected Executives" and of the compact disc "Recess for the Soul," an assemblage of monologues about…

White-Light Diffraction with a CD

ERIC Educational Resources Information Center

Ivanov, Dragia Trifonov; Nikolaev, Stefan

2010-01-01

Various wave optics experiments can be carried out using an ordinary compact disc. The CD is suitable for use as a diffraction grating. For instance, a standard CD (700 MB) has 625 lines/mm. In this article, the authors describe two white-light diffraction demonstrations for a large audience, realizable using a CD (as reflection or transmission…

New Access Points to ERIC--CD-ROM Versions. ERIC Digest.

ERIC Educational Resources Information Center

McLaughlin, Pamela W.

This digest reviews three CD-ROM (compact disc-read only memory) versions of the ERIC (Educational Resources Information Center) database currently being delivered or tested and provides information for comparison. However, no attempt is made to recommend any one product. The advantages and disadvantages of the acquisition of CD-ROM databases are…

Big Hand Produces CD-I World Disc--First Title Authored Entirely with MediaMogul.

ERIC Educational Resources Information Center

Buckman, Brad; Grant, Valerie

1993-01-01

Discusses Big Hand Productions' development of CD-I-WORLD, an interactive multimedia magazine on compact disk, designed for mass appeal and complete with advertising. Features of MediaMogul, the prepackaged authoring software that made production of this innovation possible, are described. Sample screen displays are included. (EA)

Microcontroller based spectrophotometer using compact disc as diffraction grid

NASA Astrophysics Data System (ADS)

Bano, Saleha; Altaf, Talat; Akbar, Sunila

2010-12-01

This paper describes the design and implementation of a portable, inexpensive and cost effective spectrophotometer. The device combines the use of compact disc (CD) media as diffraction grid and 60 watt bulb as a light source. Moreover it employs a moving slit along with stepper motor for obtaining a monochromatic light, photocell with spectral sensitivity in visible region to determine the intensity of light and an amplifier with a very high gain as well as an advanced virtual RISC (AVR) microcontroller ATmega32 as a control unit. The device was successfully applied to determine the absorbance and transmittance of KMnO4 and the unknown concentration of KMnO4 with the help of calibration curve. For comparison purpose a commercial spectrophotometer was used. There are not significant differences between the absorbance and transmittance values estimated by the two instruments. Furthermore, good results are obtained at all visible wavelengths of light. Therefore, the designed instrument offers an economically feasible alternative for spectrophotometric sample analysis in small routine, research and teaching laboratories, because the components used in the designing of the device are cheap and of easy acquisition.

Compact disk error measurements

NASA Technical Reports Server (NTRS)

Howe, D.; Harriman, K.; Tehranchi, B.

1993-01-01

The objectives of this project are as follows: provide hardware and software that will perform simple, real-time, high resolution (single-byte) measurement of the error burst and good data gap statistics seen by a photoCD player read channel when recorded CD write-once discs of variable quality (i.e., condition) are being read; extend the above system to enable measurement of the hard decision (i.e., 1-bit error flags) and soft decision (i.e., 2-bit error flags) decoding information that is produced/used by the Cross Interleaved - Reed - Solomon - Code (CIRC) block decoder employed in the photoCD player read channel; construct a model that uses data obtained via the systems described above to produce meaningful estimates of output error rates (due to both uncorrected ECC words and misdecoded ECC words) when a CD disc having specific (measured) error statistics is read (completion date to be determined); and check the hypothesis that current adaptive CIRC block decoders are optimized for pressed (DAD/ROM) CD discs. If warranted, do a conceptual design of an adaptive CIRC decoder that is optimized for write-once CD discs.

The AMBRE project: Constraining the lithium evolution in the Milky Way

NASA Astrophysics Data System (ADS)

Guiglion, G.; de Laverny, P.; Recio-Blanco, A.; Worley, C. C.; De Pascale, M.; Masseron, T.; Prantzos, N.; Mikolaitis, Š.

2016-10-01

Context. The chemical evolution of lithium in the Milky Way represents a major problem in modern astrophysics. Indeed, lithium is, on the one hand, easily destroyed in stellar interiors, and, on the other hand, produced at some specific stellar evolutionary stages that are still not well constrained. Aims: The goal of this paper is to investigate the lithium stellar content of Milky Way stars in order to put constraints on the lithium chemical enrichment in our Galaxy, in particular in both the thin and thick discs. Methods: Thanks to high-resolution spectra from the ESO archive and high quality atmospheric parameters, we were able to build a massive and homogeneous catalogue of lithium abundances for 7300 stars derived with an automatic method coupling, a synthetic spectra grid, and a Gauss-Newton algorithm. We validated these lithium abundances with literature values, including those of the Gaia benchmark stars. Results: In terms of lithium galactic evolution, we show that the interstellar lithium abundance increases with metallicity by 1 dex from [M/H] = -1 dex to + 0.0 dex. Moreover, we find that this lithium ISM abundance decreases by about 0.5 dex at super-solar metalllicity. Based on a chemical separation, we also observed that the stellar lithium content in the thick disc increases rather slightly with metallicity, while the thin disc shows a steeper increase. The lithium abundance distribution of α-rich, metal-rich stars has a peak at ALi ~ 3 dex. Conclusions: We conclude that the thick disc stars suffered of a low lithium chemical enrichment, showing lithium abundances rather close to the Spite plateau while the thin disc stars clearly show an increasing lithium chemical enrichment with the metallicity, probably thanks to the contribution of low-mass stars. Full Table 2 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/595/A18

The Gaia-ESO Survey: Lithium enrichment histories of the Galactic thick and thin disc

NASA Astrophysics Data System (ADS)

Fu, X.; Romano, D.; Bragaglia, A.; Mucciarelli, A.; Lind, K.; Delgado Mena, E.; Sousa, S. G.; Randich, S.; Bressan, A.; Sbordone, L.; Martell, S.; Korn, A. J.; Abia, C.; Smiljanic, R.; Jofré, P.; Pancino, E.; Tautvaišienė, G.; Tang, B.; Magrini, L.; Lanzafame, A. C.; Carraro, G.; Bensby, T.; Damiani, F.; Alfaro, E. J.; Flaccomio, E.; Morbidelli, L.; Zaggia, S.; Lardo, C.; Monaco, L.; Frasca, A.; Donati, P.; Drazdauskas, A.; Chorniy, Y.; Bayo, A.; Kordopatis, G.

2018-02-01

Lithium abundance in most of the warm metal-poor main sequence stars shows a constarnt plateau (A(Li) 2.2 dex) and then the upper envelope of the lithium vs. metallicity distribution increases as we approach solar metallicity. Meteorites, which carry information about the chemical composition of the interstellar medium (ISM) at the solar system formation time, show a lithium abundance A(Li) 3.26 dex. This pattern reflects the Li enrichment history of the ISM during the Galaxy lifetime. After the initial Li production in big bang nucleosynthesis, the sources of the enrichment include asymptotic giant branch (AGB) stars, low-mass red giants, novae, type II supernovae, and Galactic cosmic rays. The total amount of enriched Li is sensitive to the relative contribution of these sources. Thus different Li enrichment histories are expected in the Galactic thick and thin disc. We investigate the main sequence stars observed with UVES in Gaia-ESO Survey iDR4 catalogue and find a Li-anticorrelation independent of [Fe/H], Teff, and log(g). Since in stellar evolution different α enhancements at the same metallicity do not lead to a measurable Li abundance change, the anticorrelation indicates that more Li is produced during the Galactic thin disc phase than during the Galactic thick disc phase. We also find a correlation between the abundance of Li and s-process elements Ba and Y, and they both decrease above the solar metallicity, which can be explained in the framework of the adopted Galactic chemical evolution models. The full Table 1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/610/A38

Eclipse studies of the dwarf nova EX Draconis

NASA Astrophysics Data System (ADS)

Baptista, R.; Catalán, M. S.; Costa, L.

2000-08-01

We report on V and R high-speed photometry of the dwarf nova EX Draconis (EX Dra) in quiescence and in outburst. The analysis of the outburst light curves indicates that the outbursts do not start in the outer disc regions. The disc expands during the rise to maximum and shrinks during decline and along the following quiescent period. The decrease in brightness at the later stages of the outburst is due to the fading of the light from the inner disc regions. At the end of two outbursts the system was seen to go through a phase of lower brightness, characterized by an out-of-eclipse level ~=15 per cent lower than the typical quiescent level and by the fairly symmetric eclipse of a compact source at disc centre with little evidence of a bright spot at disc rim. New eclipse timings were measured from the light curves taken in quiescence and a revised ephemeris was derived. The residuals with respect to the linear ephemeris are well described by a sinusoid of amplitude 1.2min and period ~=4yr and are possibly related to a solar-like magnetic activity cycle in the secondary star. Eclipse phases of the compact central source and of the bright spot were used to derive the geometry of the binary. By constraining the gas stream trajectory to pass through the observed position of the bright spot, we find q=0.72+/-0.06 and i85+3-2 degrees. The binary parameters were estimated by combining the measured mass ratio with the assumption that the secondary star obeys an empirical main-sequence mass-radius relation. We find M1=0.75+/-0.15Msolar and M2=0.54+/-0.10Msolar. The results indicate that the white dwarf at disc centre is surrounded by an extended and variable atmosphere or boundary layer of at least three times its radius and a temperature of T~=28000K. The fluxes at mid-eclipse yield an upper limit to the contribution of the secondary star and lead to a lower limit photometric parallax distance of D=290+/-80pc. The fluxes of the secondary star are well-matched by those of a M0+/-2 main-sequence star.

Metallicity of solar-type stars with debris discs and planets⋆

NASA Astrophysics Data System (ADS)

Maldonado, J.; Eiroa, C.; Villaver, E.; Montesinos, B.; Mora, A.

2012-05-01

Context. Around 16% of the solar-like stars in our neighbourhood show IR-excesses due to dusty debris discs and a fraction of them are known to host planets. Determining whether these stars follow any special trend in their properties is important to understand debris disc and planet formation. Aims: We aim to determine in a homogeneous way the metallicity of a sample of stars with known debris discs and planets. We attempt to identify trends related to debris discs and planets around solar-type stars. Methods: Our analysis includes the calculation of the fundamental stellar parameters Teff, log g, microturbulent velocity, and metallicity by applying the iron ionisation equilibrium conditions to several isolated Fe i and Fe ii lines. High-resolution échelle spectra (R ~ 57 000) from 2, 3 m class telescopes are used. Our derived metallicities are compared with other results in the literature, which finally allows us to extend the stellar samples in a consistent way. Results: The metallicity distributions of the different stellar samples suggest that there is a transition toward higher metallicities from stars with neither debris discs nor planets to stars hosting giant planets. Stars with debris discs and stars with neither debris nor planets follow a similar metallicity distribution, although the distribution of the first ones might be shifted towards higher metallicities. Stars with debris discs and planets have the same metallicity behaviour as stars hosting planets, irrespective of whether the planets are low-mass or gas giants. In the case of debris discs and giant planets, the planets are usually cool, - semimajor axis larger than 0.1 AU (20 out of 22 planets), even ≈65% have semimajor axis larger than 0.5 AU. The data also suggest that stars with debris discs and cool giant planets tend to have a low dust luminosity, and are among the less luminous debris discs known. We also find evidence of an anticorrelation between the luminosity of the dust and the planet eccentricity. Conclusions: Our data show that the presence of planets, not the debris disc, correlates with the stellar metallicity. The results confirm that core-accretion models represent suitable scenarios for debris disc and planet formation. These conclusions are based on a number of stars with discs and planets considerably larger than in previous works, in particular stars hosting low-mass planets and debris discs. Dynamical instabilities produced by eccentric giant planets could explain the suggested dust luminosity trends observed for stars with debris discs and planets. Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC); observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica); observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias; and data obtained from the ESO Science Archive Facility.Full Tables 1 and 5 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/541/A40

A likely planet-induced gap in the disc around T Cha

NASA Astrophysics Data System (ADS)

Hendler, Nathanial P.; Pinilla, Paola; Pascucci, Ilaria; Pohl, Adriana; Mulders, Gijs; Henning, Thomas; Dong, Ruobing; Clarke, Cathie; Owen, James; Hollenbach, David

2018-03-01

We present high-resolution (0.11 × 0.06 arcsec2) 3 mm ALMA observations of the highly inclined transition disc around the star T Cha. Our continuum image reveals multiple dust structures: an inner disc, a spatially resolved dust gap, and an outer ring. When fitting sky-brightness models to the real component of the 3 mm visibilities, we infer that the inner emission is compact (≤1 au in radius), the gap width is between 18 and 28 au, and the emission from the outer ring peaks at ˜36 au. We compare our ALMA image with previously published 1.6 μm VLT/SPHERE imagery. This comparison reveals that the location of the outer ring is wavelength dependent. More specifically, the peak emission of the 3 mm ring is at a larger radial distance than that of the 1.6 μm ring, suggesting that millimeter-sized grains in the outer disc are located farther away from the central star than micron-sized grains. We discuss different scenarios to explain our findings, including dead zones, star-driven photoevaporation, and planet-disc interactions. We find that the most likely origin of the dust gap is from an embedded planet, and estimate - for a single planet scenario - that T Cha's gap is carved by a 1.2MJup planet.

Galaxy interactions in compact groups - II. Abundance and kinematic anomalies in HCG 91c

NASA Astrophysics Data System (ADS)

Vogt, Frédéric P. A.; Dopita, Michael A.; Borthakur, Sanchayeeta; Verdes-Montenegro, Lourdes; Heckman, Timothy M.; Yun, Min S.; Chambers, Kenneth C.

2015-07-01

Galaxies in Hickson Compact Group 91 (HCG 91) were observed with the WiFeS integral field spectrograph as part of our ongoing campaign targeting the ionized gas physics and kinematics inside star-forming members of compact groups. Here, we report the discovery of H II regions with abundance and kinematic offsets in the otherwise unremarkable star-forming spiral HCG 91c. The optical emission line analysis of this galaxy reveals that at least three H II regions harbour an oxygen abundance ˜0.15 dex lower than expected from their immediate surroundings and from the abundance gradient present in the inner regions of HCG 91c. The same star-forming regions are also associated with a small kinematic offset in the form of a lag of 5-10 km s-1 with respect to the local circular rotation of the gas. H I observations of HCG 91 from the Very Large Array and broad-band optical images from Pan-STARRS (Panoramic Survey Telescope And Rapid Response System) suggest that HCG 91c is caught early in its interaction with the other members of HCG 91. We discuss different scenarios to explain the origin of the peculiar star-forming regions detected with WiFeS, and show that evidence points towards infalling and collapsing extraplanar gas clouds at the disc-halo interface, possibly as a consequence of long-range gravitational perturbations of HCG 91c from the other group members. As such, HCG 91c provides evidence that some of the perturbations possibly associated with the early phase of galaxy evolution in compact groups impact the star-forming disc locally, and on sub-kpc scales.

Fractal cometary dust - a window into the early Solar system

NASA Astrophysics Data System (ADS)

Mannel, T.; Bentley, M. S.; Schmied, R.; Jeszenszky, H.; Levasseur-Regourd, A. C.; Romstedt, J.; Torkar, K.

2016-11-01

The properties of dust in the protoplanetary disc are key to understanding the formation of planets in our Solar system. Many models of dust growth predict the development of fractal structures which evolve into non-fractal, porous dust pebbles representing the main component for planetesimal accretion. In order to understand comets and their origins, the Rosetta orbiter followed comet 67P/Churyumov-Gerasimenko for over two years and carried a dedicated instrument suite for dust analysis. One of these instruments, the MIDAS (Micro-Imaging Dust Analysis System) atomic force microscope, recorded the 3D topography of micro- to nanometre-sized dust. All particles analysed to date have been found to be hierarchical agglomerates. Most show compact packing; however, one is extremely porous. This paper contains a structural description of a compact aggregate and the outstanding porous one. Both particles are tens of micrometres in size and show rather narrow subunit size distributions with noticeably similar mean values of 1.48^{+0.13}_{-0.59} μm for the porous particle and 1.36^{+0.15}_{-0.59} μm for the compact. The porous particle allows a fractal analysis, where a density-density correlation function yields a fractal dimension of Df = 1.70 ± 0.1. GIADA, another dust analysis instrument on board Rosetta, confirms the existence of a dust population with a similar fractal dimension. The fractal particles are interpreted as pristine agglomerates built in the protoplanetary disc and preserved in the comet. The similar subunits of both fractal and compact dust indicate a common origin which is, given the properties of the fractal, dominated by slow agglomeration of equally sized aggregates known as cluster-cluster agglomeration.

The Smith Cloud: surviving a high-speed transit of the Galactic disc

NASA Astrophysics Data System (ADS)

Tepper-García, Thor; Bland-Hawthorn, Joss

2018-02-01

The origin and survival of the Smith high-velocity H I cloud has so far defied explanation. This object has several remarkable properties: (i) its prograde orbit is ≈100 km s-1 faster than the underlying Galactic rotation; (ii) its total gas mass (≳ 4 × 106 M⊙) exceeds the mass of all other high-velocity clouds (HVCs) outside of the Magellanic Stream; (iii) its head-tail morphology extends to the Galactic H I disc, indicating some sort of interaction. The Smith Cloud's kinetic energy rules out models based on ejection from the disc. We construct a dynamically self-consistent, multi-phase model of the Galaxy with a view to exploring whether the Smith Cloud can be understood in terms of an infalling, compact HVC that has transited the Galactic disc. We show that while a dark-matter (DM) free HVC of sufficient mass and density can reach the disc, it does not survive the transit. The most important ingredient to survival during a transit is a confining DM subhalo around the cloud; radiative gas cooling and high spatial resolution (≲ 10pc) are also essential. In our model, the cloud develops a head-tail morphology within ∼10 Myr before and after its first disc crossing; after the event, the tail is left behind and accretes on to the disc within ∼400 Myr. In our interpretation, the Smith Cloud corresponds to a gas 'streamer' that detaches, falls back and fades after the DM subhalo, distorted by the disc passage, has moved on. We conclude that subhaloes with MDM ≲ 109 M⊙ have accreted ∼109 M⊙ of gas into the Galaxy over cosmic time - a small fraction of the total baryon budget.

The ALMA early science view of FUor/EXor objects - V. Continuum disc masses and sizes

NASA Astrophysics Data System (ADS)

Cieza, Lucas A.; Ruíz-Rodríguez, Dary; Perez, Sebastian; Casassus, Simon; Williams, Jonathan P.; Zurlo, Alice; Principe, David A.; Hales, Antonio; Prieto, Jose L.; Tobin, John J.; Zhu, Zhaohuan; Marino, Sebastian

2018-03-01

Low-mass stars build a significant fraction of their total mass during short outbursts of enhanced accretion known as FUor and EXor outbursts. FUor objects are characterized by a sudden brightening of ˜5 mag at visible wavelengths within 1 yr and remain bright for decades. EXor objects have lower amplitude outbursts on shorter time-scales. Here we discuss a 1.3 mm Atacama Large Millimeter/submillimeter Array (ALMA) mini-survey of eight outbursting sources (three FUors, four EXors, and the borderline object V1647 Ori) in the Orion Molecular Cloud. While previous papers in this series discuss the remarkable molecular outflows observed in the three FUor objects and V1647 Ori, here we focus on the continuum data and the differences and similarities between the FUor and EXor populations. We find that FUor discs are significantly more massive (˜80-600 MJup) than the EXor objects (˜0.5-40 MJup). We also report that the EXor sources lack the prominent outflows seen in the FUor population. Even though our sample is small, the large differences in disc masses and outflow activity suggest that the two types of objects represent different evolutionary stages. The FUor sources seem to be rather compact (Rc < 20-40 au) and to have a smaller characteristic radius for a given disc mass when compared to T Tauri stars. V1118 Ori, the only known close binary system in our sample, is shown to host a disc around each one of the stellar components. The disc around HBC 494 is asymmetric, hinting at a structure in the outer disc or the presence of a second disc.

Age Matters: Student Experiences with Audio Learning Guides in University-Based Continuing Education

ERIC Educational Resources Information Center

Mercer, Lorraine; Pianosi, Birgit

2012-01-01

The primary objective of this research was to explore the experiences of undergraduate distance education students using sample audio versions (provided on compact disc) of the learning guides for their courses. The results of this study indicated that students responded positively to the opportunity to have word-for-word audio versions of their…

Census, CD-ROM, and You! New Horizons for Microcomputer Users of Census Bureau Data.

ERIC Educational Resources Information Center

Bureau of the Census (DOC), Washington, DC. Data User Services Div.

This introductory guide to Census Bureau data that is currently available to microcomputer users on compact disc (CD-ROM) begins by explaining the types of information available, how CD-ROM works, and the hardware and software required to access the databases using a microcomputer. Descriptions of data currently available on CD-ROM include…

Large-scale silviculture experiments of western Oregon and Washington.

Treesearch

Nathan J. Poage; Paul D. Anderson

2007-01-01

We review 12 large-scale silviculture experiments (LSSEs) in western Washington and Oregon with which the Pacific Northwest Research Station of the USDA Forest Service is substantially involved. We compiled and arrayed information about the LSSEs as a series of matrices in a relational database, which is included on the compact disc published with this report and...

The Rise of K-12 Blended Learning: Profiles of Emerging Models

ERIC Educational Resources Information Center

Staker, Heather

2011-01-01

Some innovations change everything. The rise of personal computers in the 1970s decimated the mini-computer industry. TurboTax forever changed tax accounting, and MP3s made libraries of compact discs obsolete. These innovations bear the traits of what Harvard Business School Professor Clayton M. Christensen terms a "disruptive innovation."…

CD-I: From Boob Tube to Teacher's Assistant--The Birth of the Smart TV.

ERIC Educational Resources Information Center

Luskin, Bernard J.

1993-01-01

Explains compact disc interactive (CD-I) and discusses possible uses in education. Advances in technology are considered; the current status of CD-I and recent developments are described, including marketing and costs; and future possibilities of CD-I in education are suggested, including digital technology and electronic and optical publishing.…

A Simple Solution to Providing Remote Access to CD-ROM.

ERIC Educational Resources Information Center

Garnham, Carla T.; Brodie, Kent

1990-01-01

A pilot project at the Medical College of Wisconsin illustrates how even small computing organizations with limited financial and staff resources can provide remote access to CD-ROM (Compact Disc-Read-Only-Memory) databases, and that providing such convenient access to a vast array of useful information can greatly benefit faculty and students.…

Information Retrieval Center: A Proposal for the Implementation of CD-ROM Database Technology at Memphis State University Libraries.

ERIC Educational Resources Information Center

Evans, John; Park, Betsy

This planning proposal recommends that Memphis State University Libraries make information on CD-ROM (compact disc--read only memory) available in the Reference Department by establishing an Information Retrieval Center (IRC). Following a brief introduction and statement of purpose, the library's databases, users, staffing, facilities, and…

78 FR 50114 - Distribution of 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, and 2009 Satellite...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-16

... categories of copyrightable content (e.g., movies, music, and sports programming). At Phase II, the royalties... electronic copy in Portable Document Format (PDF) on a Compact Disc, along with the $150 filing fee, to the... request are: Joint Sports Claimants (JSC), Program Suppliers, Devotional Claimants, [[Page 50115...

48 CFR 2452.204-70 - Preservation of, and access to, contract records (tangible and electronically stored information...

Code of Federal Regulations, 2013 CFR

2013-10-01

... or data storage). ESI devices and media include, but are not be limited to: (1) Computers (mainframe...) Personal data assistants (PDAs); (5) External data storage devices including portable devices (e.g., flash drive); and (6) Data storage media (magnetic, e.g., tape; optical, e.g., compact disc, microfilm, etc...

48 CFR 2452.204-70 - Preservation of, and access to, contract records (tangible and electronically stored information...

Code of Federal Regulations, 2014 CFR

2014-10-01

... or data storage). ESI devices and media include, but are not be limited to: (1) Computers (mainframe...) Personal data assistants (PDAs); (5) External data storage devices including portable devices (e.g., flash drive); and (6) Data storage media (magnetic, e.g., tape; optical, e.g., compact disc, microfilm, etc...

The Music of the Spheres

ERIC Educational Resources Information Center

Lewicki, Martin; Hughes, Stephen

2012-01-01

This article describes a method for making a spectroscope from scrap materials, i.e. a fragment of compact disc, a cardboard box, a tube and a digital camera to record the spectrum. An image processing program such as ImageJ can be used to calculate the wavelength of emission and absorption lines from the digital photograph. Multiple images of a…

Production of the entire range of r-process nuclides by black hole accretion disc outflows from neutron star mergers

NASA Astrophysics Data System (ADS)

Wu, Meng-Ru; Fernández, Rodrigo; Martínez-Pinedo, Gabriel; Metzger, Brian D.

2016-12-01

We consider r-process nucleosynthesis in outflows from black hole accretion discs formed in double neutron star and neutron star-black hole mergers. These outflows, powered by angular momentum transport processes and nuclear recombination, represent an important - and in some cases dominant - contribution to the total mass ejected by the merger. Here we calculate the nucleosynthesis yields from disc outflows using thermodynamic trajectories from hydrodynamic simulations, coupled to a nuclear reaction network. We find that outflows produce a robust abundance pattern around the second r-process peak (mass number A ˜ 130), independent of model parameters, with significant production of A < 130 nuclei. This implies that dynamical ejecta with high electron fraction may not be required to explain the observed abundances of r-process elements in metal poor stars. Disc outflows reach the third peak (A ˜ 195) in most of our simulations, although the amounts produced depend sensitively on the disc viscosity, initial mass or entropy of the torus, and nuclear physics inputs. Some of our models produce an abundance spike at A = 132 that is absent in the Solar system r-process distribution. The spike arises from convection in the disc and depends on the treatment of nuclear heating in the simulations. We conclude that disc outflows provide an important - and perhaps dominant - contribution to the r-process yields of compact binary mergers, and hence must be included when assessing the contribution of these systems to the inventory of r-process elements in the Galaxy.

Through thick and thin: Structure of the Galactic thick disc from extragalactic surveys

NASA Astrophysics Data System (ADS)

Kordopatis, G.; Hill, V.; Irwin, M.; Gilmore, G.; Wyse, R. F. G.; Tolstoy, E.; de Laverny, P.; Recio-Blanco, A.; Battaglia, G.; Starkenburg, E.

2013-07-01

Context. We aim to understand the accretion history of the Milky Way by exploring the vertical and radial properties of the Galactic thick disc. Aims: We study the chemical and kinematic properties of roughly a thousand spectra of faint magnitude foreground Galactic stars observed serendipitously during extra-galactic surveys in four lines-of-sight: three in the southern Galactic hemisphere (surveys of the Carina, Fornax and Sculptor dwarf spheroidal galaxies) and one in the northern Galactic hemisphere (a survey of the Sextans dwarf spheroidal galaxy). The foreground stars span distances up to ~3 kpc from the Galactic plane and Galactocentric radii up to 11 kpc. Methods: The stellar atmospheric parameters (effective temperature, surface gravity, metallicity) are obtained by an automated parameterisation pipeline and the distances of the stars are then derived by a projection of the atmospheric parameters on a set of theoretical isochrones using a Bayesian approach. The metallicity gradients are estimated for each line-of-sight and compared with predictions from the Besançon model of the Galaxy, in order to test the chemical structure of the thick disc. Finally, we use the radial velocities in each line-of-sight to derive a proxy for either the azimuthal or the vertical component of the orbital velocity of the stars. Results: Only three lines-of-sight have a sufficient number of foreground stars for a robust analysis. Towards Sextans in the Northern Galactic hemisphere and Sculptor in the South, we measure a consistent decrease in mean metallicity with height from the Galactic plane, suggesting a chemically symmetric thick disc. This decrease can either be due to an intrinsic thick disc metallicity gradient, or simply due to a change in the thin disc/thick disc population ratio and no intrinsic metallicity gradients for the thick disc. We favour the latter explanation. In contrast, we find evidence of an unpredicted metal-poor population in the direction of Carina. This population was earlier detected, but our more detailed analysis provides robust estimates of its location (|Z| < 1 kpc), metallicity (-2 < [M/H] < -1 dex) and azimuthal orbital velocity (Vφ ~ 120 km s-1). Conclusions: Given the chemo-dynamical properties of the over-density towards the Carina line-of-sight, we suggest that it represents the metal-poor tail of the canonical thick disc. In spite of the small number of stars available, we suggest that this metal-weak thick disc follows the often suggested canonical thick disc velocity-metallicity correlation of ∂Vφ/∂ [M/H] ~ 40-50 km s-1 dex-1. Based on observations collected at the European Southern Observatory at Paranal, Chile, ESO Large Programme 171.B-0588 (DART) and 171.B-0520(A).Full Tables 2 and 4 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/555/A12

Where are compact groups in the local Universe?

NASA Astrophysics Data System (ADS)

Díaz-Giménez, Eugenia; Zandivarez, Ariel

2015-06-01

Aims: The purpose of this work is to perform a statistical analysis of the location of compact groups in the Universe from observational and semi-analytical points of view. Methods: We used the velocity-filtered compact group sample extracted from the Two Micron All Sky Survey for our analysis. We also used a new sample of galaxy groups identified in the 2M++ galaxy redshift catalogue as tracers of the large-scale structure. We defined a procedure to search in redshift space for compact groups that can be considered embedded in other overdense systems and applied this criterion to several possible combinations of different compact and galaxy group subsamples. We also performed similar analyses for simulated compact and galaxy groups identified in a 2M++ mock galaxy catalogue constructed from the Millennium Run Simulation I plus a semi-analytical model of galaxy formation. Results: We observed that only ~27% of the compact groups can be considered to be embedded in larger overdense systems, that is, most of the compact groups are more likely to be isolated systems. The embedded compact groups show statistically smaller sizes and brighter surface brightnesses than non-embedded systems. No evidence was found that embedded compact groups are more likely to inhabit galaxy groups with a given virial mass or with a particular dynamical state. We found very similar results when the analysis was performed using mock compact and galaxy groups. Based on the semi-analytical studies, we predict that 70% of the embedded compact groups probably are 3D physically dense systems. Finally, real space information allowed us to reveal the bimodal behaviour of the distribution of 3D minimum distances between compact and galaxy groups. Conclusions: The location of compact groups should be carefully taken into account when comparing properties of galaxies in environments that are a priori different. Appendices are available in electronic form at http://www.aanda.orgFull Tables B.1 and B.2 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/578/A61

A tutorial on the principles of harmonic intonation for trombonists

NASA Astrophysics Data System (ADS)

Keener, Michael Kenneth

A Tutorial on the Principles of Harmonic Intonation for Trombonists includes a manual containing background information, explanations of the principles of harmonic intonation, and printed musical examples for use in learning and practicing the concepts of harmonic intonation. An audio compact disk containing music files corresponding to the printed music completes the set. This tutorial is designed to allow performing musicians and students to practice intonation skills with the pitch-controlled music on the compact disc. The music on the CD was recorded in movable-comma just intonation, replicating performance parameters of wind, string, and vocal ensembles. The compact disc includes sixty tracks of ear-training exercises and interval studies with which to practice intonation perception and adjustment. Tuning notes and examples of equal-tempered intervals and just intervals are included on the CD. The intonation exercises consist of musical major scales, duets, trios, and quartet phrases to be referenced while playing the printed music. The CD tracks allow the performer to play scales in unison (or practice other harmonic intervals) or the missing part of the corresponding duet, trio, or quartet exercise. Instructions in the manual guide the user through a process that can help prepare musicians for more accurate musical ensemble performance. The contextual essay that accompanies the tutorial includes a description of the tutorial, a review of related literature, methodology of construction of the tutorial, evaluations and outcomes, conclusions and recommendations for further research, and a selected bibliography.

Nuclear Rings in Galaxies - A Kinematic Perspective

NASA Technical Reports Server (NTRS)

Mazzuca, Lisa M.; Swaters, Robert A.; Knapen, Johan H.; Veilleux, Sylvain

2011-01-01

We combine DensePak integral field unit and TAURUS Fabry-Perot observations of 13 nuclear rings to show an interconnection between the kinematic properties of the rings and their resonant origin. The nuclear rings have regular and symmetric kinematics, and lack strong non-circular motions. This symmetry, coupled with a direct relationship between the position angles and ellipticities of the rings and those of their host galaxies, indicate the rings are in the same plane as the disc and are circular. From the rotation curves derived, we have estimated the compactness (v(sup 2)/r) up to the turnover radius, which is where the nuclear rings reside. We find that there is evidence of a correlation between compactness and ring width and size. Radially wide rings are less compact, and thus have lower mass concentration. The compactness increases as the ring width decreases. We also find that the nuclear ring size is dependent on the bar strength, with weaker bars allowing rings of any size to form.

Determining the locations of the various CIRC recording format information blocks (user data blocks, C2 and C1 words and EFM frames) on a recorded compact disc

NASA Technical Reports Server (NTRS)

Howe, Dennis G.

1993-01-01

Just prior to its being EFM modulated (i.e., converted to eight-to-fourteen channel data by the EFM encoder) and written to a Compact Disc (CD), information that passes through the CIRC Block Encoder is grouped into 33-byte blocks referred to as EFM frames. Twenty four of the bytes that make up a given EFM frame are user data that was input into the CIRC encoder at various (different) times, 4 of the bytes of this same EFM frame were created by the C2 ECC encoder (each at a different time), and another 4 were created by the C1 ECC encoder (again, each at a different time). The one remaining byte of the given EFM frame, which is known as the EFM frame C&D (for Control & Display) byte, carries information that identifies which portion of the current disc program track the given EFM frame belongs to and also specifies the location of the given EFM frame on the disc (in terms of a time stamp that has a resolution of l/75th second, or 98 EFM frames). (Note: since the program track and time information is stored as a 98-byte word, a logical group consisting of 98 consecutive EFM frames must be read, and their respective C&D bytes must be catenated and decoded, before the program track identification and time position information that pertains to the entire block of 98 EFM frames can be obtained.) The C&D byte is put at the start (0th byte) of an EFM frame in real time; its placement completes the construction of the EFM frame - it is assigned just before the EFM frame enters the EFM encoder. Four distinct blocks of data are referred to: 24-byte User Input Data Blocks; 28-byte C2 words; 32-byte C1 words; and 33-byte EFM frames.

A contracting circumbinary molecular ring around Ori 139-409 with an inner cavity of about 140 au

NASA Astrophysics Data System (ADS)

Zapata, Luis A.; Schilke, Peter; Ho, Paul T. P.

2010-03-01

We present sensitive and subarcsecond resolution (~0.7 arcsec) CH3OH(7-2,6-6-2,5) line and 890-μm continuum observations, made with the Submillimeter Array (SMA), towards the hot molecular circumbinary ring associated with the young multiple star Ori 139-409. The CH3OH(7-2,6-6-2,5) emission from the ring is well resolved at this angular resolution, revealing an inner cavity with a size of about 140 au. A local thermodynamic equilibrium model of a Keplerian disc with an inner cavity of the same size confirms the presence of this cavity. Additionally, this model suggests that the circumbinary ring is contracting with a velocity of Vinf ~ 1.5kms-1 towards the binary central compact circumstellar discs reported at a wavelength of 7 mm. The inner central cavity seems to be formed by the tidal effects of the young stars in the middle of the ring. The ring does not appear to be a stationary object. Furthermore, the infall velocity we determine is about a factor of 3 slower than the free-fall velocity corresponding to the dynamical mass. This would correspond to a mass accretion rate of about 10-5 Msolar yr-1. We have found that the dust emission associated with Ori 139-409 appears to be arising from the circumstellar discs, with no strong contribution from the molecular gas ring. Furthermore, a simple comparison with other classical molecular dusty rings (e.g. GG Tau, UZ Tau and UY Aur) suggests that Ori 139-409 could be one of the youngest circumbinary rings reported to date. Finally, our results confirm that the circumbinary rings are actively funnelling fresh gas material to the central compact binary circumstellar discs (i.e. to the protostars in the very early phases of their evolution).

Music Preferences in the U.S.: 1982-2002

ERIC Educational Resources Information Center

Mizell, Lee

2005-01-01

Music is everywhere. People listen to compact discs while relaxing at home, MP3s while jogging in the park, live music concerts in their free time, and internet radio on the computer. What are people listening to? Who is doing the listening? How have listening patterns changed over time? This report aims to answer those questions by using data…

Kan Na! Authentic Chinese Reading. Lessons for Intermediate to Advanced Self-Study. [CD-ROM].

ERIC Educational Resources Information Center

Fleming, Stephen; Hiple, David; Ning, Cynthia

This compact disc offers several lessons in Chinese, including a photo feature from a Chinese newspaper, the service directory from a Chinese hotel room, a pamphlet for travelers from Taiwan, a family letter, an introduction to Chinese cuisine, an article about a hijacking, a letter of agreement between institutions, an odyssey of a teenaged boy,…

78 FR 79638 - Energy Conservation Program for Consumer Products: Proposed Determination of Hearth Products as a...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-31

... a compact disc (CD), in which case it is not necessary to include printed copies. Hand Delivery... on a CD, in which case it is not necessary to include printed copies. Instructions: All submissions... v. Department of Energy, et al., 706 F.3d 499 (D.C. Cir. 2013). DOE has not previously conducted an...

An Examination of Essential Popular Music Compact Disc Holdings at the Cleveland Public Library.

ERIC Educational Resources Information Center

Halliday, Blane

In the 1970s and early 1980s, a few library researchers and scholars made a case for the importance of public libraries' acquisition of popular music, particularly rock music sound recordings. Their arguments were based on the anticipated historical and cultural importance of obtaining and maintaining a collection of these materials. Little new…

Software to Promote Young Children's Growth in Literacy: A Comparison of Online and Offline Formats

ERIC Educational Resources Information Center

Wood, Eileen; Grant, Amy K.; Gottardo, Alexandra; Savage, Robert; Evans, Mary Ann

2017-01-01

The primary goal of this research was to extend our understanding of the strengths and weaknesses inherent in online and offline early literacy software programs designed for young learners. A taxonomy of reading skills was used to contrast online software with offline closed system (compact disc) based programs with respect to number of skills…

Cool Tools for the New Frontier: Technological Advances Help Associates Tell Their Story.

ERIC Educational Resources Information Center

Hersch, James

1998-01-01

Argues that creation of a World Wide Web site that makes good use of the available digital audio and visual technologies can be useful in campus activities planning and advertising. The design of a good Web site and the potential uses of digital video and compact discs are discussed. Costs of these technologies are also outlined. (MSE)

Hangul Ro Boja! Authentic Korean Video. Lessons for Intermediate to Advanced Self-Study. [CD-ROM].

ERIC Educational Resources Information Center

Joo, H.; Choo, M.; Yeun, Soo-ah Kim; Hiple, David

This compact disc offers 10 Korean lessons from a variety of authentic sources, including the following: television commercials and scenes from a soap opera, news reports on politics, sports, the environment, and a book fair; and scenes from a Korean film, "Our Twisted Hero." The learner is lead through a series of activities aiding…

Surface morphology changes to tungsten under exposure to He ions from an electron cyclotron resonance plasma source

NASA Astrophysics Data System (ADS)

Donovan, David; Maan, Anurag; Duran, Jonah; Buchenauer, Dean; Whaley, Josh

2015-11-01

Exposure of tungsten to low energy (<100 eV) helium plasmas at temperatures between 900-1900 K in both laboratory experiments and tokamaks has been shown to cause severe nanoscale modification of the near surface resulting the growth of tungsten tendrils. We used a relatively low flux (2.5x1019 ions m-2 s-1) compact ECR plasma source at Sandia-California to investigate the early stages of helium induced tungsten damage. Exposures of polished tungsten discs were performed and characterized using SEM, AFM, and FIB cross section imaging. Bubbles have been seen on the exposed tungsten surface and in sub-surface cross sections growing to up to 150 nm in diameter. Comparisons were made between exposures of warm rolled Plansee tungsten discs and ALMT ITER grade tungsten samples. A similar He plasma exposure stage has now been developed at the University of Tennessee-Knoxville with an improved compact ECR plasma source. Status of the new UTK exposure stage will be discussed as well as planned experiments and new material characterization techniques (EBSD, GIXRD). Work supported by US DOE Contract DE-AC04-94AL85000 and the PSI Science Center.

Fractal dust constrains the collisional history of comets

NASA Astrophysics Data System (ADS)

Fulle, M.; Blum, J.

2017-07-01

The fractal dust particles observed by Rosetta cannot form in the physical conditions observed today in comet 67P/Churyumov-Gerasimenko (67P hereinafter), being instead consistent with models of the pristine dust aggregates coagulated in the solar nebula. Since bouncing collisions in the protoplanetary disc restructure fractals into compact aggregates (pebbles), the only way to preserve fractals in a comet is the gentle gravitational collapse of a mixture of pebbles and fractals, which must occur before their mutual collision speeds overcome ≈1 m s-1. This condition fixes the pebble radius to ≲1 cm, as confirmed by Comet Nucleus Infrared and Visible Analyser onboard Philae. Here, we show that the flux of fractal particles measured by Rosetta constrains the 67P nucleus in a random packing of cm-sized pebbles, with all the voids among them filled by fractal particles. This structure is inconsistent with any catastrophic collision, which would have compacted or dispersed most fractals, thus leaving empty most voids in the reassembled nucleus. Comets are less numerous than current estimates, as confirmed by lacking small craters on Pluto and Charon. Bilobate comets accreted at speeds <1 m s-1 from cometesimals born in the same disc stream.

Implementation of a departmental picture archiving and communication system: a productivity and cost analysis.

PubMed

Macyszyn, Luke; Lega, Brad; Bohman, Leif-Erik; Latefi, Ahmad; Smith, Michelle J; Malhotra, Neil R; Welch, William; Grady, Sean M

2013-09-01

Digital radiology enhances productivity and results in long-term cost savings. However, the viewing, storage, and sharing of outside imaging studies on compact discs at ambulatory offices and hospitals pose a number of unique challenges to a surgeon's efficiency and clinical workflow. To improve the efficiency and clinical workflow of an academic neurosurgical practice when evaluating patients with outside radiological studies. Open-source software and commercial hardware were used to design and implement a departmental picture archiving and communications system (PACS). The implementation of a departmental PACS system significantly improved productivity and enhanced collaboration in a variety of clinical settings. Using published data on the rate of information technology problems associated with outside studies on compact discs, this system produced a cost savings ranging from $6250 to $33600 and from $43200 to $72000 for 2 cohorts, urgent transfer and spine clinic patients, respectively, therefore justifying the costs of the system in less than a year. The implementation of a departmental PACS system using open-source software is straightforward and cost-effective and results in significant gains in surgeon productivity when evaluating patients with outside imaging studies.

Metastable alloy materials produced by solid state reaction of compacted, mechanically deformed mixtures

DOEpatents

Atzmon, Michael; Johnson, William L.; Verhoeven, John D.

1987-01-01

Bulk metastable, amorphous or fine crystalline alloy materials are produced by reacting cold-worked, mechanically deformed filamentary precursors such as metal powder mixtures or intercalated metal foils. Cold-working consolidates the metals, increases the interfacial area, lowers the free energy for reaction, and reduces at least one characteristic dimension of the metals. For example, the grains (13) of powder or the sheets of foil are clad in a container (14) to form a disc (10). The disc (10) is cold-rolled between the nip (16) of rollers (18,20) to form a flattened disc (22). The grains (13) are further elongated by further rolling to form a very thin sheet (26) of a lamellar filamentary structure (FIG. 4) containing filaments having a thickness of less than 0.01 microns. Thus, diffusion distance and time for reaction are substantially reduced when the flattened foil (28) is thermally treated in oven (32) to form a composite sheet (33) containing metastable material (34) dispersed in unreacted polycrystalline material (36).

Fast luminous blue transients from newborn black holes

NASA Astrophysics Data System (ADS)

Kashiyama, Kazumi; Quataert, Eliot

2015-08-01

Newborn black holes in collapsing massive stars can be accompanied by a fallback disc. The accretion rate is typically super-Eddington and strong disc outflows are expected. Such outflows could be directly observed in some failed explosions of compact (blue supergiants or Wolf-Rayet stars) progenitors, and may be more common than long-duration gamma-ray bursts. Using an analytical model, we show that the fallback disc outflows produce blue UV-optical transients with a peak bolometric luminosity of ˜ 1042-43 erg s- 1 (peak R-band absolute AB magnitudes of -16 to -18) and an emission duration of ˜ a few to ˜10 d. The spectra are likely dominated intermediate mass elements, but will lack much radioactive nuclei and iron-group elements. The above properties are broadly consistent with some of the rapid blue transients detected by Panoramic Survey Telescope & Rapid Response System and Palomar Transient Factory. This scenario can be distinguished from alternative models using radio observations within a few years after the optical peak.

Deformation of the Galactic Centre stellar cusp due to the gravity of a growing gas disc

NASA Astrophysics Data System (ADS)

Kaur, Karamveer; Sridhar, S.

2018-06-01

The nuclear star cluster surrounding the massive black hole at the Galactic Centre consists of young and old stars, with most of the stellar mass in an extended, cuspy distribution of old stars. The compact cluster of young stars was probably born in situ in a massive accretion disc around the black hole. We investigate the effect of the growing gravity of the disc on the orbits of the old stars, using an integrable model of the deformation of a spherical star cluster with anisotropic velocity dispersions. A formula for the perturbed phase-space distribution function is derived using linear theory, and new density and surface density profiles are computed. The cusp undergoes a spheroidal deformation with the flattening increasing strongly at smaller distances from the black hole; the intrinsic axis ratio ˜0.8 at ˜0.15 pc. Stellar orbits are deformed such that they spend more time near the disc plane and sample the dense inner parts of the disc; this could result in enhanced stripping of the envelopes of red giant stars. Linear theory accounts only for orbits whose apsides circulate. The non-linear theory of adiabatic capture into resonance is needed to understand orbits whose apsides librate. The mechanism is a generic dynamical process, and it may be common in galactic nuclei.

Exoplanet recycling in massive white-dwarf debris discs

NASA Astrophysics Data System (ADS)

Van Lieshout, Rik

2017-06-01

When a star evolves into a white dwarf, the planetary system it hosts can become unstable. Planets in such systems may then be scattered onto star-grazing orbits, leading to their tidal disruption as they pass within the white dwarf’s Roche limit. We study the massive, compact debris discs that may arrise from this process using a combination of analytical estimates and numerical modelling. The discs are gravitationally unstable, resulting in an enhanced effective viscosity due to angular momentum transport associated with self-gravity wakes. For disc masses greater than ~1026 g (corresponding to progenitor objects comparable to the Galilean moons), viscous spreading dominates over Poynting-Robertson drag in the outer parts of the disc. In such massive discs, mass is transported both in- and outwards. When the outward-flowing material spreads beyond the Roche limit, it coagulates into new (minor) planets in a process analogous to the ongoing formation of Saturn’s innermost moonlets. This process recycles a substantial fraction of the original disc mass (tens of percents), with the bulk of the mass locked in a single large body orbitting in a 2:1 mean-motion resonance with the Roche limit. As such, the recycling of a tidally disrupted super-Earth could yield an Earth-mass planet on a 10--20 hr orbit. For white dwarfs with a temperature below 6000-7000 K (corresponding to a cooling age of >1--2 Gyr), this orbit is located in the white dwarf’s habitable zone. The recycling process also creates a string of smaller bodies just outside the Roche limit. These may account for the collection of minor planets postulated to orbit white dwarf WD 1145+017.

OCEAN-PC and a distributed network for ocean data

NASA Technical Reports Server (NTRS)

Mclain, Douglas R.

1992-01-01

The Intergovernmental Oceanographic Commission (IOC) wishes to develop an integrated software package for oceanographic data entry and access in developing countries. The software, called 'OCEAN-PC', would run on low cost PC microcomputers and would encourage and standardize: (1) entry of local ocean observations; (2) quality control of the local data; (3) merging local data with historical data; (4) improved display and analysis of the merged data; and (5) international data exchange. OCEAN-PC will link existing MS-DOS oceanographic programs and data sets with table-driven format conversions. Since many ocean data sets are now being distributed on optical discs (Compact Discs - Read Only Memory, CD-ROM, Mass et al. 1987), OCEAN-PC will emphasize access to CD-ROMs.

Automated assembly of microfluidic "lab-on-a-disc"

NASA Astrophysics Data System (ADS)

Berger, M.; Müller, T.; Voebel, T.; Baum, C.; Glennon, T.; Mishra, R.; Kinahan, D.; King, D.; Ducrée, J.; Brecher, C.

2018-02-01

Point-of-care (POC) testing attracts more and more attention in the medical health sector because of their specific property to perform the diagnostic close to the patient. The fast diagnosis right at the hospital or the doctor's office improves the medical reaction time and the chances for a successful healing process. One of this POC test systems is a "Lab-on-a-Disc" (LoaD) which looks like a compact disc crisscrossed with microfluidic tubes and cavities. The fluid to be analysed is placed in the LoaD and an external device then rotates the LoaD. The cavities inside the LoaD and the centrifugal force ensure a clearly defined sequence of the analysis. Furthermore, we aim for an inexpensive manufacture of the medical product without neglecting its quality and functionality. Therefore, the Fraunhofer IPT works on an assembly cell to implement dissoluble films concisely into the disc. This dissoluble film demonstrates its successful usage as a gate for the fluid, which opens after a predefined moment in the cycle. Furthermore, we investigate to integrate a laser welding process into our gantry system and demonstrate its efficiency with the welding of polymer discs. This procedure is clinically safe because no further laser absorption material is needed in the sealing process, which might pollute the LoaD. Moreover, this process allows the alignment of several discs before the welding and therefore leads to precisely manufactured LoaDs in large quantities. All these methods together enable a fast, costefficient and reliable mass production to bring POC testing among the people.

Two-dimensional multi-component photometric decomposition of CALIFA galaxies

NASA Astrophysics Data System (ADS)

Méndez-Abreu, J.; Ruiz-Lara, T.; Sánchez-Menguiano, L.; de Lorenzo-Cáceres, A.; Costantin, L.; Catalán-Torrecilla, C.; Florido, E.; Aguerri, J. A. L.; Bland-Hawthorn, J.; Corsini, E. M.; Dettmar, R. J.; Galbany, L.; García-Benito, R.; Marino, R. A.; Márquez, I.; Ortega-Minakata, R. A.; Papaderos, P.; Sánchez, S. F.; Sánchez-Blazquez, P.; Spekkens, K.; van de Ven, G.; Wild, V.; Ziegler, B.

2017-02-01

We present a two-dimensional multi-component photometric decomposition of 404 galaxies from the Calar Alto Legacy Integral Field Area data release 3 (CALIFA-DR3). They represent all possible galaxies with no clear signs of interaction and not strongly inclined in the final CALIFA data release. Galaxies are modelled in the g, r, and I Sloan Digital Sky Survey (SDSS) images including, when appropriate, a nuclear point source, bulge, bar, and an exponential or broken disc component. We use a human-supervised approach to determine the optimal number of structures to be included in the fit. The dataset, including the photometric parameters of the CALIFA sample, is released together with statistical errors and a visual analysis of the quality of each fit. The analysis of the photometric components reveals a clear segregation of the structural composition of galaxies with stellar mass. At high masses (log (M⋆/M⊙) > 11), the galaxy population is dominated by galaxies modelled with a single Sérsic or a bulge+disc with a bulge-to-total (B/T) luminosity ratio B/T > 0.2. At intermediate masses (9.5 < log (M⋆/M⊙) < 11), galaxies described with bulge+disc but B/T < 0.2 are preponderant, whereas, at the low mass end (log (M⋆/M⊙) < 9.5), the prevailing population is constituted by galaxies modelled with either purediscs or nuclear point sources+discs (I.e., no discernible bulge). We obtain that 57% of the volume corrected sample of disc galaxies in the CALIFA sample host a bar. This bar fraction shows a significant drop with increasing galaxy mass in the range 9.5 < log (M⋆/M⊙) < 11.5. The analyses of the extended multi-component radial profile result in a volume-corrected distribution of 62%, 28%, and 10% for the so-called Type I (pure exponential), Type II (down-bending), and Type III (up-bending) disc profiles, respectively. These fractions are in discordance with previous findings. We argue that the different methodologies used to detect the breaks are the main cause for these differences. The catalog of fitted parameters is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/598/A32

78 FR 63410 - Energy Conservation Program for Consumer Products: Test Procedures for Direct Heating Equipment...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-24

... items on a compact disc (CD), in which case it is not necessary to include printed copies. Hand Delivery... on a CD, in which case it is not necessary to include printed copies. For detailed instructions on... opinion. Hearth, Patio & Barbecue Association v. U.S. Department of Energy, 706 F.3d 499, 509 (D.C. Cir...

The sounds of handheld audio players.

PubMed

Rudy, Susan F

2007-01-01

Hearing experts and public health organizations have longstanding hearing safety concerns about personal handheld audio devices, which are growing in both number and popularity. This paper reviews the maximum sound levels of handheld compact disc players, MP3 players, and an iPod. It further reviews device factors that influence the sound levels produced by these audio devices and ways to reduce the risk to hearing during their use.

37 CFR 1.52 - Language, paper, writing, margins, compact disc specifications.

Code of Federal Regulations, 2010 CFR

2010-07-01

... cm (3/4 inch), a left side margin of at least 2.5 cm (1 inch), a right side margin of at least 2.0 cm... brackets should appear to the right of the left margin as the first item in each paragraph, before the... elements, and should not be independently numbered. If a nontext element extends to the left margin, it...

Rigorous embedding of cell dynamics simulations in the Cahn-Hilliard-Cook framework: Imposing stability and isotropy

NASA Astrophysics Data System (ADS)

Sevink, G. J. A.

2015-05-01

We have rigorously analyzed the stability of the efficient cell dynamics simulations (CDS) method by making use of the special properties of the local averaging operator <<*>>-* in matrix form. Besides resolving a theoretical issue that has puzzled many over the past three decades, this analysis has considerable practical value: It relates CDS directly to finite-difference approximations of the Cahn-Hilliard-Cook equations and provides a straightforward recipe for replacing the original two- or three-dimensional (2D or 3D) averaging operators in CDS by an equivalent (in terms of stability) discrete Laplacian with superior isotropy and scaling behavior. As such, we open up a route to suppress the unphysical reflection of the computational grid in CDS results (grid artifacts). We found that proper rescaling of discrete Laplacians, needed to employ them in CDS, is equivalent to introducing a well-chosen time step in CDS. In turn, our analysis provides stability conditions for phase-field simulations based on the Cahn-Hilliard-Cook equations. Subsequently, we have quantitatively compared the isotropy and scaling behavior of several discrete 2D or 3D Laplacians, thereby extending the significance of this work to general field-based methodology. We found that all considered discrete Laplacians have equivalent scaling behavior along the Cartesian directions. In addition, and somewhat surprisingly, known "isotropic" discrete Laplacians, i.e., isotropic up to fourth order in |k | , become quite anisotropic for larger wave vectors, whereas "less isotropic" discrete Laplacians (second order) are only slightly anisotropic on the whole |k | range. We identified a hard limit to the accuracy with which the discrete Laplacian can emulate the two important properties of the optimal (continuum) Laplacian, as an improvement of the isotropy, by introducing additional points to the stencil, will negatively affect the scaling behavior. Within this limitation, the discrete compact Laplacians in the D n Q m class known from lattice hydrodynamics, D 2 Q 9 in 2D and D 3 Q 19 in 3D, are found to be optimal in terms of isotropy. However, by being only slightly anisotropic on the whole range and enabling larger time steps, the discrete Laplacians that relate to the local averaging operator of Oono and Puri (2D) and Shinozaki and Oono (3D) as well as the less familiar 3D discrete B v V Laplacian developed for dynamic density functional theory are valid alternatives.

Optical and near-infrared IFU spectroscopy of the nuclear region of the AGN-starburst galaxy NGC 7582

NASA Astrophysics Data System (ADS)

Ricci, T. V.; Steiner, J. E.; May, D.; Garcia-Rissmann, A.; Menezes, R. B.

2018-02-01

NGC 7582 is an SB(s)ab galaxy which displays evidences of simultaneous nuclear activity and star formation in its centre. Previous optical observations revealed, besides the H II regions, an ionization cone and a gas disc in its central part. Hubble Space Telescope (HST) images in both optical and infrared bands show the active galactic nuclei (AGNs) and a few compact structures that are possibly associated with young stellar clusters. In order to study in detail both the AGN and evidence for star formation, we analyse optical (Gemini Multi-Object Spectrograph) and near-infrared (Spectrograph for Integral Field Observations in the Near Infrared) archival data cubes. We detected five nebulae with strong He II λ4686 emission in the same region where an outflow is detected in the [O III] λ5007 kinematic map. We interpreted this result as clouds that are exposed to high-energy photons emerging from the AGN throughout the ionization cone. We also detected Wolf-Rayet features which are related to emission of one of the compact clusters seen in the HST image. Broad Hα and Br γ components are detected at the position of the nucleus. [Fe II] λ1.644 μm, H2λ2.122 μm and Br γ flux maps show two blobs, one north and the other south from the nucleus, that seem to be associated with five previously detected mid-infrared sources. Two of the five He II nebulae are partially ionized by photons from starbursts. However, we conclude that the main source of excitation of these blobs is the AGN jet/disc. The jet orientation indicates that the accretion disc is nearly orthogonal to the dusty torus.

Accretion onto stellar mass black holes

NASA Astrophysics Data System (ADS)

Deegan, Patrick

2009-12-01

I present work on the accretion onto stellar mass black holes in several scenarios. Due to dynamical friction stellar mass black holes are expected to form high density cusps in the inner parsec of our Galaxy. These compact remnants may be accreting cold dense gas present there, and give rise to potentially observable X-ray emission. I build a simple but detailed time-dependent model of such emission. Future observations of the distribution and orbits of the gas in the inner parsec of Sgr A* will put tighter constraints on the cusp of compact remnants. GRS 1915+105 is an LMXB, whose large orbital period implies a very large accretion disc and explains the extraordinary duration of its current outburst. I present smoothed particle hydrodynamic simulations of the accretion disc. The models includes the thermo-viscous instability, irradiation from the central object and wind loss. I find that the outburst of GRS 1915+105 should last a minimum of 20 years and up to ˜ 100 years if the irradiation is playing a significant role in this system. The predicted recurrence times are of the order of 104 years, making the duty cycle of GRS 1915+105 to be a few 0.1%. I present a simple analytical method to describe the observable behaviour of long period black hole LMXBs, similar to GRS 1915+105. Constructing two simple models for the surface density in the disc, outburst and quiescence times are calculated as a function of orbital period. LMXBs are an important constituent of the X-ray light function (XLF) of giant elliptical galaxies. I find that the duty cycle can vary considerably with orbital period, with implications for modelling the XLF.

Investigation of the effect of alumina and compaction pressure on physical, electrical and tribological properties of Al-Fe-Cr-Al2O3 powder composites

NASA Astrophysics Data System (ADS)

Mohsin, Mohammad; Mohd, Aas; Suhaib, M.; Arif, Sajjad; Arif Siddiqui, M.

2017-10-01

In this experimental work, aluminium Al-20Fe-5Cr (in wt.%) matrix reinforced with varying wt.% Al2O3 (0, 10, 20 and 30) and compaction pressure (470, 550 and 600 MPa) were prepared by powder metallurgy technique. The characterization of composites were performed by scanning electron microscopy (SEM), x-ray diffraction (XRD), energy dispersive spectrum (EDS) and elemental mapping. Uniform distribution of Al2O3 in aluminium matrix were observed by elemental mapping. The composites showed an increase in density and hardness by increasing both alumina and compaction pressure. While, electrical conductivity decreased by the addition of alumina. The tribological study of the composites were performed on pin-on-disc apparatus at sliding conditions (applied load 40 N, sliding speed 1.5 m s-1, sliding distance 300 m). The tribological properties of the composites were improved by increasing alumina and compaction pressure. SEM analysis were also carried out to understand wear mechanism of the worn surfaces of various fabricated composites and aluminium matrix.

The Thermal Equilibrium Solution of a Generic Bipolar Quantum Hydrodynamic Model

NASA Astrophysics Data System (ADS)

Unterreiter, Andreas

The thermal equilibrium state of a bipolar, isothermic quantum fluid confined to a bounded domain ,d = 1,2 or d = 3 is entirely described by the particle densities n, p, minimizing the energy where G1,2 are strictly convex real valued functions, . It is shown that this variational problem has a unique minimizer in and some regularity results are proven. The semi-classical limit is carried out recovering the minimizer of the limiting functional. The subsequent zero space charge limit leads to extensions of the classical boundary conditions. Due to the lack of regularity the asymptotics can not be settled on Sobolev embedding arguments. The limit is carried out by means of a compactness-by-convexity principle.

Improved Properties of Pb Based BLZT Ferroelectric Ceramics

NASA Astrophysics Data System (ADS)

Kumar, Parveen; Singh, Sangeeta; Juneja, J. K.; Raina, K. K.; Prakash, Chandra

2011-11-01

Present report is concerning with investigation of effect of different sintering profiles on Pb based BLZT ceramics. The material powder of selected composition (Ba0.795La0.005Pb0.20Ti0.90Zr0.10O3) was prepared by solid state reaction route and then powder was compacted in the form of circular discs. The discs were then sintered at different temperatures (1325 °C for 4h, 1325 °C for 15min+1200 °C for 4h). Improved dielectric and ferroelectric properties were observed for samples sintered at 1200 °C. Shifting in Tc to higher temperature could be related to enhanced tetragonality, which was further confirmed by X-ray diffraction analysis. All these improvements evidences that there is less Pb loss in case of modified sintering profile.

Information Dissemination: Innovative Ways Agencies Are Using Technology. Testimony before the Government Information, Justice, and Agriculture Subcommittee, Committee on Government Operations, House of Representatives.

ERIC Educational Resources Information Center

Brock, Jack L., Jr.

This testimony discusses ways in which some federal government agencies use technology to provide the public with cheaper, faster access to a wider range of information which can be searched and manipulated in ways never possible on the printed page. Technologies included in the discussion are compact disc-read only memory (CD-ROM), electronic…

Reproductive and Hormonal Risk Factors for Breast Cancer in Blind Women

DTIC Science & Technology

2008-08-01

informational letters sent directly from the Perkins Braille and Talking Book Library in Watertown Massachusetts, the ACB and the Canadian National Institute...choice. Survey formats included via e-mail, website, compact disc, computer disk, audio tape, large print, Braille , in person, or verbally over the...survey data during telephone interviews or following receipt of written or audio surveys. Braille surveys were transcribed by a third party and

Magnetic and magneto elastic properties of cobalt ferrite ceramic compacted through cold isostatic pressing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Indla, Srinivas; Das, Dibakar, E-mail: ddse@uohyd.ernet.in; Chelvane, Arout

2016-05-06

Nano crystalline CoFe{sub 2}O{sub 4} powder was prepared by combustion synthesis method. As synthesized powder was calcined at an appropriate condition to remove the impurities and to promote phase formation. Phase pure CoFe{sub 2}O{sub 4} powder was pressed into cylindrical rod at an applied pressure of 200 MPa using a cold isostatic pressing. Sintering of the green compact at 1350°c for 12 hrs resulted in sintered cylindrical rod with ~85% of the theoretical density. Single phase cubic spinel structure was observed in the powder x-ray diffraction pattern of the sintered pellet. Scanning electron micrographs (SEM) of the as sintered pelletmore » revealed the microstructure to be composed of ferrite grains of average size ~4 µm. Saturation magnetization of 72 emu/g and coercivity of 355 Oe were observed for cobalt ferrite sample. The magnetostriction was measured on a circular disc (12 mm diameter and 12 mm length) with the strain gauge (350 Ω) mounted on the flat surface of the circular disc. Magnetostriciton of 180 ppm and strain derivative of 1 × 10{sup −9} m/A were observed for the sintered CoFe{sub 2}O{sub 4} sample.« less

A field-deployable mobile molecular diagnostic system for malaria at the point of need.

PubMed

Choi, Gihoon; Song, Daniel; Shrestha, Sony; Miao, Jun; Cui, Liwang; Guan, Weihua

2016-11-01

In response to the urgent need of a field-deployable and highly sensitive malaria diagnosis, we developed a standalone, "sample-in-answer-out" molecular diagnostic system (AnyMDx) to enable quantitative molecular analysis of blood-borne malaria in low resource areas. The system consists of a durable battery-powered analyzer and a disposable microfluidic compact disc loaded with reagents ready for use. A low power thermal module and a novel fluorescence-sensing module are integrated into the analyzer for real-time monitoring of loop-mediated isothermal nucleic acid amplification (LAMP) of target parasite DNA. With 10 μL of raw blood sample, the AnyMDx system automates the nucleic acid sample preparation and subsequent LAMP and real-time detection. Under laboratory conditions with whole-blood samples spiked with cultured Plasmodium falciparum, we achieved a detection limit of ∼0.6 parasite per μL, much lower than those for the conventional microscopy and rapid diagnostic tests (∼50-100 parasites per μL). The turnaround time from sample to answer is less than 40 minutes. The AnyMDx is user-friendly requiring minimal technological training. The analyzer and the disposable reagent compact discs are cost-effective, making AnyMDx a potential tool for malaria molecular diagnosis under field settings for malaria elimination.

On the high energy cut-off of accreting sources: Is general relativity relevant?

NASA Astrophysics Data System (ADS)

Tamborra, Francesco; Papadakis, Iossif; Dovčiak, Michal; Svoboda, Jiři

2018-04-01

The hard X-ray emission observed in accreting compact sources is believed to be produced by inverse Compton scattering of soft photons arising from the accretion disc by energetic electrons thermally distributed above the disc, the so-called X-ray corona. Many independent observations suggest that such coronae should be compact and located very close to the black hole. In this case, general relativistic (GR) effects should play an important role to the continuum X-ray emission from these sources, and, in particular, in the observed high energy cut-off, which is a measure of the intrinsic temperature of the corona. Our results show that the energy shift between the observed and intrinsic high energy cut-off due to GR effects can be as large as two to eight times, depending on the geometry and size of the corona as well as its inclination. We provide estimates of this energy shift in the case of a lamp-post and a flat, rotating corona, around a Kerr and a Schwartzschild black hole, for various inclinations, and coronal sizes. These values could be useful to correct the observed high energy cut-off and/or coronal temperatures, either in the case of individual or large sample of objects.

On the Brγ line emission of the Herbig Ae/Be star MWC 120

NASA Astrophysics Data System (ADS)

Kreplin, Alexander; Tambovtseva, Larisa; Grinin, Vladimir; Kraus, Stefan; Weigelt, Gerd; Wang, Yang

2018-06-01

The origin of the Br γ line in Herbig Ae/Be stars is still an open question. It has been proposed that a fraction of the 2.166-μm Br γ emission might emerge from a disc wind, the magnetosphere and other regions. Investigations of the Br γ line in young stellar objects are important to improve our understanding of the accretion-ejection process. Near-infrared long-baseline interferometry enables the investigation of the Br γ line-emitting region with high spatial and high spectral resolution. We observed the Herbig Ae/Be star MWC 120 with the Astronomical Multi-Beam Recombiner (AMBER) on the Very Large Telescope Interferometer (VLTI) in different spectral channels across the Br γ line with a spectral resolution of R ˜ 1500. Comparison of the visibilities, differential and closure phases in the continuum and the line-emitting region with geometric and radiative transfer disc-wind models leads to constraints on the origin and dynamics of the gas emitting the Br γ light. Geometric modelling of the visibilities reveals a line-emission region about two times smaller than the K-band continuum region, which indicates a scenario where the Br γ emission is dominated by an extended disc wind rather than by a much more compact magnetospheric origin. To compare our data with a physical model, we applied a state-of-the-art radiative transfer disc-wind model. We find that all measured visibilities, differential and closure phases of MWC 120 can be approximately reproduced by a disc-wind model. A comparison with other Herbig stars indicates a correlation of the modelled inner disc-wind radii with the corresponding Alfvén radii for late spectral type stars.

High surface plasmon resonance sensitivity enabled by optical disks.

PubMed

Dou, Xuan; Phillips, Blayne M; Chung, Pei-Yu; Jiang, Peng

2012-09-01

We report a systematic, experimental, and theoretical investigation on the surface plasmon resonance (SPR) sensing using optical disks with different track pitches, including Blu-ray disk (BD), digital versatile disk (DVD), and compact disk (CD). Optical reflection measurements indicate that CD and DVD exhibit much higher SPR sensitivity than BD. Both experiments and finite-difference time-domain simulations reveal that the SPR sensitivity is significantly affected by the diffraction order of the SPR peaks and higher diffraction order results in lower sensitivity. Numerical simulations also show that very high sensitivity (∼1600  nm per refractive index unit) is achievable by CDs.

Constructing a Plastic Bottle Wind Turbine as a Practical Aid for Learning about Using Wind Energy to Generate Electricity

ERIC Educational Resources Information Center

Appleyard, S. J.

2009-01-01

A simple horizontal axis wind turbine can be easily constructed using a 1.5 l PET plastic bottle, a compact disc and a small dynamo. The turbine operates effectively at low wind speeds and has a rotational speed of 500 rpm at a wind speed of about 14 km h[superscript -1]. The wind turbine can be used to demonstrate the relationship between open…

The Endcap Disc DIRC of PANDA

NASA Astrophysics Data System (ADS)

Düren, M.; Etzelmüller, E.; Föhl, K.; Hayrapetyan, A.; Kröck, B.; Merle, O.; Rieke, J.; Schmidt, M.; Wasem, T.; Britting, A.; Eyrich, W.; Lehmann, A.; Pfaffinger, M.; Uhlig, F.; Belias, A.; Dzhygadlo, R.; Gerhardt, A.; Götzen, K.; Kalicy, G.; Krebs, M.; Lehmann, D.; Nerling, F.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Zühlsdorf, M.; Cowie, E.; Keri, T.; Achenbach, P.; Cardinali, M.; Hoek, M.; Lauth, W.; Schlimme, S.; Sfienti, C.; Thiel, M.

2017-12-01

The Endcap Disc DIRC (EDD) for PANDA has been designed to identify traversing pions, kaons and protons in the future PANDA experiment. Its central part is a 2 cm thick fused silica plate. Focussing optics are attached to the outer rim of the plate, outside of the acceptance of the experiment. Fast, high-resolution MCP-PMTs, designed to register single Cherenkov photons, have been tested in magnetic field. Filters limit the spectral acceptance of the sensors to reduce dispersion effects and to extend their lifetime. A compact and fast readout is realized with ASICs. Analytical reconstruction algorithms allow for fast particle identification. The angular resolution of a DIRC prototype has been simulated in Monte Carlo and confirmed in a test beam. The final detector will be able to provide a 4 σπ / K separation up to a momentum of 4 GeV / c .

Design of band-notched antenna with DG-CEBG

NASA Astrophysics Data System (ADS)

Jaglan, Naveen; Kanaujia, Binod Kumar; Gupta, Samir Dev; Srivastava, Shweta

2018-01-01

Ultra-wideband (UWB) disc monopole antenna with crescent shaped slot for double band-notched features is presented. Planned antenna discards worldwide interoperability for microwave access (WiMAX) band (3.3-3.6 GHz) and wireless local area network (WLAN) band (5-6 GHz). Defected ground compact electromagnetic band gap (DG-CEBG) designs are used to accomplish band notches in WiMAX and WLAN bands. Defected ground planes are utilised to achieve compactness in electromagnetic band gap (EBG) structures. The proposed WiMAX and WLAN DG-CEBG designs show a compactness of around 46% and 50%, respectively, over mushroom EBG structures. Parametric analyses of DG-CEBG design factors are carried out to control the notched frequencies. Stepwise notch transition from upper to lower frequencies is presented with incremental inductance augmentation. The proposed antenna is made-up on low-cost FR-4 substrate of complete extents as (42 × 50 × 1.6) mm3.Fabricated sample antenna shows excellent consistency in simulated and measured outcomes.

Ultrafiltration by a compacted clay membrane-I. Oxygen and hydrogen isotopic fractionation

USGS Publications Warehouse

Coplen, T.B.; Hanshaw, B.B.

1973-01-01

Laboratory experiments were carried out to determine the magnitude of the isotopic fractionation of distilled water and of 0.01 N NaCl forced to flow at ambient temperature under a hydraulic pressure drop of 100 bars across a montmorillonite disc compacted to a porosity of 35 per cent by a pressure of 330 bars. The ultrafiltrates in both experiments were depleted in D by 2.5%. and in O18 by 0.8%. relative to the residual solution. No additional isotopic fractionation due to a salt filtering mechanism was observed at NaCl concentrations up to 0.01 N. Adsorption is most likely the principal mechanism which produces isotopic fractionation, but molecular diffusion may play a minor role. The results suggest that oxygen and hydrogen isotopic fractionation of ground water during passage through compacted clayey sediments should be a common occurrence, in accord with published interpretations of isotopic data from the Illinois and Alberta basins. ?? 1973.

The USGS Side-Looking Airborne Radar (SLAR) program: CD-ROMs expand potential for petroleum exploration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kover, A.N.; Schoonmaker, J.W. Jr.; Pohn. H.A.

1991-03-01

The United States Geological Survey (USGS) began the systematic collection of Side-Looking Airborne Radar (SLAR) data in 1980. The SLAR image data, useful for many geologic applications including petroleum exploration, are compiled into mosaics using the USGS 1:250,000-scale topographic map series for format and control. Mosaics have been prepared for over 35% of the United States. Image data collected since 1985 are also available as computer compatible tapes (CCTs) for digital analysis. However, the use of tapes is often cumbersome. To make digital data more readily available for use on a microcomputer, the USGS has started to prepare compact discs-readmore » only memory (CD-ROM). Several experimental discs have been compiled to demonstrate the utility of the medium to make available very large data sets. These discs include necessary nonproprietary software text, radar, and other image data. The SLAR images selected for these discs show significantly different geologic features and include the Long Valley caldera, a section of the San Andreas fault in the Monterey area, the Grand Canyon, and glaciers in southeastern Alaska. At present, several CD-ROMs are available as standard products distributed by the USGS EROS Data Center in Sioux Falls, South Dakota 57198. This is also the source for all USGS SLAR photographic and digital material.« less

Multi-wavelength Observations of Accreting Compact Objects

NASA Astrophysics Data System (ADS)

Hernandez Santisteban, Juan Venancio

2016-11-01

The study of compact binaries invokes core astrophysical concepts ranging from stellar and sub-stellar atmospheres and interiors, stellar and binary evolution to physics of accretion. All of these systems are hosts to a compact object a white dwarf, neutron star or black hole ???? which produces a wide variety of exotic and energetic phenomena across the full electromagnetic spectrum. In this thesis, I will make use of multi-wavelength observations ranging from far-ultraviolet to nearinfrared in order to investigate two main topics: a) the late evolution of cataclysmic variables, and b) the accreting state of transitional millisecond pulsars. Firstly, I analyse the Very Large Telescope X-Shooter time-resolved spectroscopy of the short orbital period cataclysmic variable, SDSS J1433+1011, in Chapter 2. The wide wavelength coverage allowed me to perform a detailed characterisation of the system, as well as a direct mass measurement of the brown dwarf companion. I show that the donor in SDSS J1433+1011 successfully transitioned from the stellar to sub-stellar regime, as predicted by evolutionary models. Further light-curve modelling allowed me to show that a low albedo as well as a low heat circulation efficiency is present in the atmosphere of the sub-stellar donor. In Chapter 3, I analyse data from large synoptic surveys, such as SDSS and PTF, to search for the predicted population of dead cataclysmic variables. Following the non-detection of dead CVs, I was able to estimate the space density (?0 < 2?10????5 pc????3) of this hidden population via a Monte Carlo simulation of the Galactic CV population. In Chapter 4, I present Hubble Space Telescope ultraviolet observations of the transitional millisecond pulsar PSR J1023+0038, during its latest accretion state. In combination with optical and near-infrared data, I show that a standard accretion disc does not reach the magnetosphere of the neutron star. Instead, the overall spectrum is consistent with a truncated disc at ? 2:3 ? 109 cm away from the compact object. Furthermore, the ultraviolet data shares remarkable similarities with the only accreting white dwarf in a propeller regime, AE Aqr. Finally, I summarise my results in Chapter 5 and provide future lines of research in accreting compact binaries based on this work.

Biophysics and protein corona analysis of Janus cyclodextrin-DNA nanocomplexes. Efficient cellular transfection on cancer cells.

PubMed

Martínez-Negro, M; Caracciolo, G; Palchetti, S; Pozzi, D; Capriotti, A L; Cavaliere, C; Laganà, A; Ortiz Mellet, C; Benito, J M; García Fernández, J M; Aicart, E; Junquera, E

2017-07-01

The self-assembling processes underlining the capabilities of facially differentiated ("Janus") polycationic amphiphilic cyclodextrins (paCDs) as non-viral gene nanocarriers have been investigated by a pluridisciplinary approach. Three representative Janus paCDs bearing a common tetradecahexanoyl multitail domain at the secondary face and differing in the topology of the cluster of amino groups at the primary side were selected for this study. All of them compact pEGFP-C3 plasmid DNA and promote transfection in HeLa and MCF-7 cells, both in absence and in presence of human serum. The electrochemical and structural characteristics of the paCD-pDNA complexes (CDplexes) have been studied by using zeta potential, DLS, SAXS, and cryo-TEM. paCDs and pDNA, when assembled in CDplexes, render effective charges that are lower than the nominal ones. The CDplexes show a self-assembling pattern corresponding to multilamellar lyotropic liquid crystal phases, characterized by a lamellar stacking of bilayers of the CD-based vectors with anionic pDNA sandwiched among them. When exposed to human serum, either in the absence or in the presence of pDNA, the surface of the cationic CD-based vector becomes coated by a protein corona (PC) whose composition has been analyzed by nanoLC-MS/MS. Some of the CDplexes herein studied showed moderate-to-high transfection levels in HeLa and MCF-7 cancer cells combined with moderate-to-high cell viabilities, as determined by FACS and MTT reduction assays. The ensemble of data provides a detail picture of the paCD-pDNA-PC association processes and a rational base to exploit the protein corona for targeted gene delivery on future in vivo applications. Copyright © 2017 Elsevier B.V. All rights reserved.

``The Legal Bit's in Russian'': Making Sense of Downloaded Music

NASA Astrophysics Data System (ADS)

Kibby, Marjorie D.

Peer-to-peer sharing of music files grew in the face of consumer dissatisfaction with the compact disc and the absence of any real alternative. Many users were more or less “forced” to turn to illegal file sharing to access single tracks, back catalogues, and niche genres. Recently the almost simultaneous arrival of broadband internet and the iPod has seen music downloading become a respectable activity and a multi-billion dollar industry.

A Colorimetric Enzyme-Linked Immunosorbent Assay (ELISA) Detection Platform for a Point-of-Care Dengue Detection System on a Lab-on-Compact-Disc.

PubMed

Thiha, Aung; Ibrahim, Fatimah

2015-05-18

The enzyme-linked Immunosorbent Assay (ELISA) is the gold standard clinical diagnostic tool for the detection and quantification of protein biomarkers. However, conventional ELISA tests have drawbacks in their requirement of time, expensive equipment and expertise for operation. Hence, for the purpose of rapid, high throughput screening and point-of-care diagnosis, researchers are miniaturizing sandwich ELISA procedures on Lab-on-a-Chip and Lab-on-Compact Disc (LOCD) platforms. This paper presents a novel integrated device to detect and interpret the ELISA test results on a LOCD platform. The system applies absorption spectrophotometry to measure the absorbance (optical density) of the sample using a monochromatic light source and optical sensor. The device performs automated analysis of the results and presents absorbance values and diagnostic test results via a graphical display or via Bluetooth to a smartphone platform which also acts as controller of the device. The efficacy of the device was evaluated by performing dengue antibody IgG ELISA on 64 hospitalized patients suspected of dengue. The results demonstrate high accuracy of the device, with 95% sensitivity and 100% specificity in detection when compared with gold standard commercial ELISA microplate readers. This sensor platform represents a significant step towards establishing ELISA as a rapid, inexpensive and automatic testing method for the purpose of point-of-care-testing (POCT) in resource-limited settings.

The AMBRE project: Iron-peak elements in the solar neighbourhood

NASA Astrophysics Data System (ADS)

Mikolaitis, Š.; de Laverny, P.; Recio-Blanco, A.; Hill, V.; Worley, C. C.; de Pascale, M.

2017-04-01

Context. The pattern of chemical abundance ratios in stellar populations of the Milky Way is a fingerprint of the Galactic chemical history. In order to interpret such chemical fossils of Galactic archaeology, chemical evolution models have to be developed. However, despite the complex physics included in the most recent models, significant discrepancies between models and observations are widely encountered. Aims: The aim of this paper is to characterise the abundance patterns of five iron-peak elements (Mn, Fe, Ni, Cu, and Zn) for which the stellar origin and chemical evolution are still debated. Methods: We automatically derived iron peak (Mn, Fe, Ni, Cu, and Zn) and α element (Mg) chemical abundances for 4666 stars, adopting classical LTE spectral synthesis and 1D atmospheric models. Our observational data collection is composed of high-resolution, high signal-to-noise ratios HARPS and FEROS spectra, which were previously parametrised by the AMBRE project. Results: We used the bimodal distribution of the magnesium-to-iron abundance ratios to chemically classify our sample stars into different Galactic substructures: thin disc, metal-poor and high-α metal rich, high-α, and low-α metal-poor populations. Both high-α and low-α metal-poor populations are fully distinct in Mg, Cu, and Zn, but these substructures are statistically indistinguishable in Mn and Ni. Thin disc trends of [Ni/Fe] and [Cu/Fe] are very similar and show a small increase at supersolar metallicities. Also, both thin and thick disc trends of Ni and Cu are very similar and indistinguishable. Yet, Mn looks very different from Ni and Cu. [Mn/Fe] trends of thin and thick discs actually have noticeable differences: the thin disc is slightly Mn richer than the thick disc. The [Zn/Fe] trends look very similar to those of [α/Fe] trends. The typical dispersion of results in both discs is low (≈0.05 dex for [Mg, Mn, and Cu/Fe]) and is even much lower for [Ni/Fe] (≈0.035 dex). Conclusions: It is clearly demonstrated that Zn is an α-like element and could be used to separate thin and thick disc stars. Moreover, we show that the [Mn/Mg] ratio could also be a very good tool for tagging Galactic substructures. From the comparison with Galactic chemical evolutionary models, we conclude that some recent models can partially reproduce the observed Mg, Zn, and, Cu behaviours in thin and thick discs and metal-poor sequences. Models mostly fail to reproduce Mn and Ni in all metallicity domains, however, models adopting yields normalised from solar chemical properties reproduce Mn and Ni better, suggesting that there is still a lack of realistic theoretical yields of some iron-peak elements. The very low scatter (≈0.05 dex) in thin and thick disc sequences could provide an observational constrain for Galactic evolutionary models that study the efficiency of stellar radial migration. Based on observations collected at ESO telescopes under the AMBRE programme. Full Table 5 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A22

Resolving the planetesimal belt of HR 8799 with ALMA

NASA Astrophysics Data System (ADS)

Booth, Mark; Jordán, Andrés; Casassus, Simon; Hales, Antonio S.; Dent, William R. F.; Faramaz, Virginie; Matrà, Luca; Barkats, Denis; Brahm, Rafael; Cuadra, Jorge

2016-07-01

The star HR 8799 hosts one of the largest known debris discs and at least four giant planets. Previous observations have found evidence for a warm belt within the orbits of the planets, a cold planetesimal belt beyond their orbits and a halo of small grains. With the infrared data, it is hard to distinguish the planetesimal belt emission from that of the grains in the halo. With this in mind, the system has been observed with ALMA in band 6 (1.34 mm) using a compact array format. These observations allow the inner edge of the planetesimal belt to be resolved for the first time. A radial distribution of dust grains is fitted to the data using an MCMC method. The disc is best fitted by a broad ring between 145^{+12}_{-12} au and 429^{+37}_{-32} au at an inclination of 40^{+5}_{-6}° and a position angle of 51^{+8}_{-8}°. A disc edge at ˜145 au is too far out to be explained simply by interactions with planet b, requiring either a more complicated dynamical history or an extra planet beyond the orbit of planet b.

The Effects of High Density on the X-ray Spectrum Reflected from Accretion Discs Around Black Holes

NASA Technical Reports Server (NTRS)

Garcia, Javier A.; Fabian, Andrew C.; Kallman, Timothy R.; Dauser, Thomas; Parker, Micahel L.; McClintock, Jeffrey E.; Steiner, James F.; Wilms, Jorn

2016-01-01

Current models of the spectrum of X-rays reflected from accretion discs around black holes and other compact objects are commonly calculated assuming that the density of the disc atmosphere is constant within several Thomson depths from the irradiated surface. An important simplifying assumption of these models is that the ionization structure of the gas is completely specified by a single, fixed value of the ionization parameter (xi), which is the ratio of the incident flux to the gas density. The density is typically fixed at n(sub e) = 10(exp 15) per cu cm. Motivated by observations, we consider higher densities in the calculation of the reflected spectrum. We show by computing model spectra for n(sub e) approximately greater than 10(exp 17) per cu cm that high-density effects significantly modify reflection spectra. The main effect is to boost the thermal continuum at energies 2 approximately less than keV. We discuss the implications of these results for interpreting observations of both active galactic nuclei and black hole binaries. We also discuss the limitations of our models imposed by the quality of the atomic data currently available.

Clinical decision support improves quality of telephone triage documentation - an analysis of triage documentation before and after computerized clinical decision support

PubMed Central

2014-01-01

Background Clinical decision support (CDS) has been shown to be effective in improving medical safety and quality but there is little information on how telephone triage benefits from CDS. The aim of our study was to compare triage documentation quality associated with the use of a clinical decision support tool, ExpertRN©. Methods We examined 50 triage documents before and after a CDS tool was used in nursing triage. To control for the effects of CDS training we had an additional control group of triage documents created by nurses who were trained in the CDS tool, but who did not use it in selected notes. The CDS intervention cohort of triage notes was compared to both the pre-CDS notes and the CDS trained (but not using CDS) cohort. Cohorts were compared using the documentation standards of the American Academy of Ambulatory Care Nursing (AAACN). We also compared triage note content (documentation of associated positive and negative features relating to the symptoms, self-care instructions, and warning signs to watch for), and documentation defects pertinent to triage safety. Results Three of five AAACN documentation standards were significantly improved with CDS. There was a mean of 36.7 symptom features documented in triage notes for the CDS group but only 10.7 symptom features in the pre-CDS cohort (p < 0.0001) and 10.2 for the cohort that was CDS-trained but not using CDS (p < 0.0001). The difference between the mean of 10.2 symptom features documented in the pre-CDS and the mean of 10.7 symptom features documented in the CDS-trained but not using was not statistically significant (p = 0.68). Conclusions CDS significantly improves triage note documentation quality. CDS-aided triage notes had significantly more information about symptoms, warning signs and self-care. The changes in triage documentation appeared to be the result of the CDS alone and not due to any CDS training that came with the CDS intervention. Although this study shows that CDS can improve documentation, further study is needed to determine if it results in improved care. PMID:24645674

Clinical decision support improves quality of telephone triage documentation--an analysis of triage documentation before and after computerized clinical decision support.

PubMed

North, Frederick; Richards, Debra D; Bremseth, Kimberly A; Lee, Mary R; Cox, Debra L; Varkey, Prathibha; Stroebel, Robert J

2014-03-20

Clinical decision support (CDS) has been shown to be effective in improving medical safety and quality but there is little information on how telephone triage benefits from CDS. The aim of our study was to compare triage documentation quality associated with the use of a clinical decision support tool, ExpertRN©. We examined 50 triage documents before and after a CDS tool was used in nursing triage. To control for the effects of CDS training we had an additional control group of triage documents created by nurses who were trained in the CDS tool, but who did not use it in selected notes. The CDS intervention cohort of triage notes was compared to both the pre-CDS notes and the CDS trained (but not using CDS) cohort. Cohorts were compared using the documentation standards of the American Academy of Ambulatory Care Nursing (AAACN). We also compared triage note content (documentation of associated positive and negative features relating to the symptoms, self-care instructions, and warning signs to watch for), and documentation defects pertinent to triage safety. Three of five AAACN documentation standards were significantly improved with CDS. There was a mean of 36.7 symptom features documented in triage notes for the CDS group but only 10.7 symptom features in the pre-CDS cohort (p < 0.0001) and 10.2 for the cohort that was CDS-trained but not using CDS (p < 0.0001). The difference between the mean of 10.2 symptom features documented in the pre-CDS and the mean of 10.7 symptom features documented in the CDS-trained but not using was not statistically significant (p = 0.68). CDS significantly improves triage note documentation quality. CDS-aided triage notes had significantly more information about symptoms, warning signs and self-care. The changes in triage documentation appeared to be the result of the CDS alone and not due to any CDS training that came with the CDS intervention. Although this study shows that CDS can improve documentation, further study is needed to determine if it results in improved care.

Typeability of DNA in Touch Traces Deposited on Paper and Optical Data Discs.

PubMed

Sołtyszewski, Ireneusz; Szeremeta, Michał; Skawrońska, Małgorzata; Niemcunowicz-Janica, Anna; Pepiński, Witold

2015-01-01

Nucleated epithelial cells that are transferred by casual touching and handling of objects are the primary source of biological evidence that is found in high-volume crimes. Cellular material associated with touch traces usually contains low levels of DNA template making it challenging to acquire an informative profile. The main purpose of this study was to examine the efficacy of DNA typing in fingerprints deposited on optical data discs and the office paper. Latent fingerprints were made by 60 subjects of both sexes (30 males and 30 females). A highly effective DNA extraction method with QIAamp DNA Mini Kit (Qiagen) and an increased sensitivity PCR by AmpFlSTR® NGM™ Amplification Kit (Applied Biosystems) carried out at standard 30 cycles and at increased 34 cycles were used. The mean value of total DNA recovery was 0.4 ng from CDs/DVDs and 0.3 ng from the office paper. Amplification of Low Template DNA (LT-DNA) resulted in improved analytical success by increasing the number of PCR cycles from standard 30 to 34. On the other hand, the increased PCR cycles resulted in allele drop-ins showing additional peaks, the majority of which were outside the stutter positions. Rigorous procedures and interpretation guidelines are required during LT-DNA for producing reliable and reproducible DNA profiles for forensic purposes.

Structural, Optical, and Electrical Properties of Cobalt-Doped CdS Quantum Dots

NASA Astrophysics Data System (ADS)

Thambidurai, M.; Muthukumarasamy, N.; Velauthapillai, Dhayalan; Agilan, S.; Balasundaraprabhu, R.

2012-04-01

In the present work, a systematic study has been carried out to understand the influence of cobalt (Co) doping on various properties of CdS nanoparticles. CdS and Co-doped CdS quantum dots have been prepared at room temperature using a chemical precipitation method without using catalysts, capping agents, or surfactants. X-ray diffraction reveals that both undoped and Co-doped CdS nanoparticles exhibit hexagonal structure without any impurity phase, and the lattice constants of CdS nanoparticles are observed to decrease slightly with increasing cobalt concentration. High-resolution transmission electron microscopy (HRTEM) shows that the particle size of CdS and 5.02% Co-doped CdS nanoparticles is in the range of 2 nm to 4 nm. The Raman spectra of Co-doped CdS nanoparticles exhibit a red-shift compared with that of bulk CdS, which may be attributed to optical phonon confinement. The optical absorption spectra of Co-doped CdS nanoparticles also exhibit a red-shift with respect to that of CdS nanoparticles. The electrical conductivity of CdS and Co-doped CdS nanoparticles is found to increase with increasing temperature and cobalt concentration.

Brightness Variations in the Solar Atmosphere as Seen by SOHO

NASA Astrophysics Data System (ADS)

Brkovic, A.; Rüedi, I.; Solanki, S. K.; Huber, M. C. E.; Stenflo, J. O.; Stucki, K.; Harrison, R.; Fludra, A.

We present preliminary results of a statistical analysis of the brightness variations of solar features at different levels in the solar atmosphere. We observed quiet Sun regions at disc centre using the Coronal Diagnostic Spectrometer (CDS) onboard the Solar and Heliospheric Observatory (SOHO). We find significant variability at all time scales in all parts of the quiet Sun, from darkest intranetwork to brightest network. Such variations are observed simultaneously in the chromospheric He I 584.33 Angstroms (2 \\cdot 10^4 K) line, the transition region O V 629.74 Angstroms (2.5 \\cdot 10^5 K) and coronal Mg IX 368.06 Angstroms (10^6 K) line. The relative variability is independent of brightness and most of the variability appears to take place on time scales longer than 5 minutes for all 3 spectral lines. No significant differences are observed between the different data sets.

Eternal 5D data storage by ultrafast laser writing in glass

NASA Astrophysics Data System (ADS)

Zhang, J.; ČerkauskaitÄ--, A.; Drevinskas, R.; Patel, A.; Beresna, M.; Kazansky, P. G.

2016-03-01

Securely storing large amounts of information over relatively short timescales of 100 years, comparable to the span of the human memory, is a challenging problem. Conventional optical data storage technology used in CDs and DVDs has reached capacities of hundreds of gigabits per square inch, but its lifetime is limited to a decade. DNA based data storage can hold hundreds of terabytes per gram, but the durability is limited. The major challenge is the lack of appropriate combination of storage technology and medium possessing the advantages of both high capacity and long lifetime. The recording and retrieval of the digital data with a nearly unlimited lifetime was implemented by femtosecond laser nanostructuring of fused quartz. The storage allows unprecedented properties including hundreds of terabytes per disc data capacity, thermal stability up to 1000 °C, and virtually unlimited lifetime at room temperature opening a new era of eternal data archiving.

Hot exozodiacal dust resolved around Vega with IOTA/IONIC

NASA Astrophysics Data System (ADS)

Defrère, D.; Absil, O.; Augereau, J.-C.; di Folco, E.; Berger, J.-P.; Coudé du Foresto, V.; Kervella, P.; Le Bouquin, J.-B.; Lebreton, J.; Millan-Gabet, R.; Monnier, J. D.; Olofsson, J.; Traub, W.

2011-10-01

Context. Although debris discs have been detected around a significant number of main-sequence stars, only a few of them are known to harbour hot dust in their inner part where terrestrial planets may have formed. Thanks to infrared interferometric observations, it is possible to obtain a direct measurement of these regions, which are of prime importance for preparing future exo-Earth characterisation missions. Aims: We resolve the exozodiacal dust disc around Vega with the help of infrared stellar interferometry and estimate the integrated H-band flux originating from the first few AUs of the debris disc. Methods: Precise H-band interferometric measurements were obtained on Vega with the 3-telescope IOTA/IONIC interferometer (Mount Hopkins, Arizona). Thorough modelling of both interferometric data (squared visibility and closure phase) and spectral energy distribution was performed to constrain the nature of the near-infrared excess emission. Results: Resolved circumstellar emission within ~6 AU from Vega is identified at the 3-σ level. The most straightforward scenario consists in a compact dust disc producing a thermal emission that is largely dominated by small grains located between 0.1 and 0.3 AU from Vega and accounting for 1.23 ± 0.45% of the near-infrared stellar flux for our best-fit model. This flux ratio is shown to vary slightly with the geometry of the model used to fit our interferometric data (variations within ± 0.19%). Conclusions: The presence of hot exozodiacal dust in the vicinity of Vega, initially revealed by K-band CHARA/FLUOR observations, is confirmed by our H-band IOTA/IONIC measurements. Whereas the origin of the dust is still uncertain, its presence and the possible connection with the outer disc suggest that the Vega system is currently undergoing major dynamical perturbations.

Further Evidence on the Effect of Acquisition Policy and Process on Cost Growth of Major Defense Acquisition Programs

DTIC Science & Technology

2016-06-01

Total Package Procurement (TPP) when it was judged to be practicable and, when not, Fixed Price Incentive Fee (FPIF) or Cost Plus Incentive Fee (CPIF...development contracts in favor of CPIF. ( Cost Plus Award Fee may not have been included in the contracting play book yet.) As a general matter, Packard’s...Group CAPE Cost Assessment and Program Evaluation CD Compact Disc CE Current Estimate CLC Calibrated Learning Curve CPIF Cost Plus Incentive Fee

Sharp Estimates in Ruelle Theorems for Matrix Transfer Operators

NASA Astrophysics Data System (ADS)

Campbell, J.; Latushkin, Y.

A matrix coefficient transfer operator , on the space of -sections of an m-dimensional vector bundle over n-dimensional compact manifold is considered. The spectral radius of is estimated bya; and the essential spectral radius by Here is the set of ergodic f-invariant measures, and for is the measure-theoretic entropy of f, is the largest Lyapunov exponent of the cocycle over f generated by , and is the smallest Lyapunov exponent of the differential of f.

International Interdisciplinary Conference (1st) on the Influence of Culture (Japanese/American) on Technological Innovation

DTIC Science & Technology

1991-11-01

associated with compact discs. He had to negotiate with Philips about technical issues for standardization and also with Japanese companies. The laser...competition (c. Davidson 1984; Kotler et a. 1985; Ozawa 1974). For example, such a firm can easily parcel out production among its foreign subsidiaries and...of indawial po4 1925-1975. Stanford University Press, Stanford, Caldoria Jer, Philip , Lrn Fahb", and Sonshid Jaetnaiak 1M6 77e New conendou Prentie

Mobile satellite service communications tests using a NASA satellite

NASA Technical Reports Server (NTRS)

Chambers, Katherine H.; Koschmeder, Louis A.; Hollansworth, James E.; ONeill, Jack; Jones, Robert E.; Gibbons, Richard C.

1995-01-01

Emerging applications of commercial mobile satellite communications include satellite delivery of compact disc (CD) quality radio to car drivers who can select their favorite programming as they drive any distance; transmission of current air traffic data to aircraft; and handheld communication of data and images from any remote corner of the world. Experiments with the enabling technologies and tests and demonstrations of these concepts are being conducted before the first satellite is launched by utilizing an existing NASA spacecraft.

Adsorption, Aggregation, and Deposition Behaviors of Carbon Dots on Minerals.

PubMed

Liu, Xia; Li, Jiaxing; Huang, Yongshun; Wang, Xiangxue; Zhang, Xiaodong; Wang, Xiangke

2017-06-06

The increased production of carbon dots (CDs) and the release and accumulation of CDs in both surface and groundwater has resulted in the increasing interest in their research. To assess the environmental behavior of CDs, the interaction between CDs and goethite was studied under different environmental conditions. Electrokinetic characterization of CDs suggested that the ζ-potential and size distribution of CDs were affected by pH and electrolyte species, indicating that these factors influenced the stability of CDs in aqueous solutions. Traditional Derjaguin-Landau-Verwey-Overbeek theory did not fit well the aggregation process of CDs. Results of the effects of pH and ionic strength suggested that electronic attraction dominated the aggregation of CDs. Compared with other minerals, hydrogen-bonding interactions and Lewis acid-base interactions contributed to the aggregation of CDs, in addition to van der Waals and electrical double-layer forces. Adsorption isotherms and microscopic Fourier transformed infrared spectroscopy indicated that chemical bonds were formed between CDs and goethite. These findings are useful to understand the interaction of CDs with minerals, as well as the potential fate and toxicity of CDs in the natural environment, especially in soils and sediments.

Multiplex fluorescent immunoassay device based on magnetic nanoparticles

NASA Astrophysics Data System (ADS)

Godjevargova, T. I.; Ivanov, Y. L.; Dinev, D. D.

2017-02-01

Immunofluorescent analyzer based compact disc for simultaneous detection of 3 antibiotics in the same milk sample is consisting of two parts: CD-based immunofluorescence kit and optoelectronic fluorometer. Kit consists of 2 parts: Lyophilized immobilized antibodies on supermagnetic nanoparticles in Eppendorf tubes and CD-based microfluidic disk, in which are formed five chamber systems for simultaneous detecting of 5 separate samples. Each system consists of 2 chambers connected by a special micro channel acting as a hydrophobic valve. In the first chamber lyophilised conjugates of 3 antibiotics with accordingly 3 different fluorescent dyes are placed. The second chamber is for detection of fluorescent signal. The optoelectronic fluorometer is comprising of: integrated thermostatic block; mechanical-detecting unit (fluorometer) and block with controlling and visualizing electronics.The disc gets into a second block of the analyzer, where centrifugation is performed and also reporting of the fluorescent signals. This unit comprises a rotor on which the disc is fixed, permanent electromagnet in the form of a ring inserted under the disc and module of 3 LED diodes with emission filters for the relevant wavelengths corresponding to the used fluorescent dyes and 1 integrated photodiode, in front of which is mounted filter with 3 spectral peaks.The signal from the photodiode is detected by the electronic unit which is sensitive "lock-in" amplifier, the engine rotor management, control of thermostatic device and management of periphery of the analyzer, consisting of display and communications with computer.

A hip wear simulator with 100 test stations.

PubMed

Saikko, V

2005-09-01

A novel high-capacity hip wear simulator of the pin-on-disc type was designed, built, and validated. This so-called Super-CTPOD (circularly translating pin-on-disc) device has as many as 100 separate test stations, being an advanced version of the previously validated 12-station CTPOD. A validity test was done so that in all stations the specimens and the test conditions were as similar as possible. Hence, for the first time in this field, an adequate number of similar tests was done for a proper statistical analysis of wear data. The pins were conventional, gamma-sterilized ultra-high molecular weight polyethylene, and the discs were polished CoCr. The lubricant was diluted calf serum and the test length 3 million cycles. In the course of the test, the pins became highly polished, whereas the discs remained practically unchanged. The majority of the polyethylene wear particles were rounded, with a mean diameter of 0.25 microm. The 100 wear factor values computed from the 100 steady state wear rate values of the pins were normally distributed, the mean +/- 95 per cent confidence interval being 1.63 +/- 0.017 x 10(-6) mm3 /N m. The standard deviation was 5.4 per cent of the mean. There were no outliers. The wear mechanisms and the wear factor agreed well with clinical findings. Altogether, the Super-CTPOD test system was shown to be a unique combination of validity, low variation, capacity, efficiency, reliability, productivity, economy, ease of operation, and compact size.

Compact discs as versatile cost-effective substrates for releasable nanopatterned aluminium films

NASA Astrophysics Data System (ADS)

Barrios, Carlos Angulo; Canalejas-Tejero, Víctor

2015-02-01

We demonstrate that standard polycarbonate compact disk surfaces can provide unique adhesion to Al films that is both strong enough to permit Al film nanopatterning and weak enough to allow easy nanopatterned Al film detachment using Scotch tape. Transferred Al nanohole arrays on Scotch tape exhibit excellent optical and plasmonic performance.We demonstrate that standard polycarbonate compact disk surfaces can provide unique adhesion to Al films that is both strong enough to permit Al film nanopatterning and weak enough to allow easy nanopatterned Al film detachment using Scotch tape. Transferred Al nanohole arrays on Scotch tape exhibit excellent optical and plasmonic performance. Electronic supplementary information (ESI) available: 1. Optical simulations (Fig. SI.1); 2. Optical coupling via an Al NHA on the Scotch tape (Fig. SI.2); 3. Electrostatics-based opto-mechanical cantilever (Fig. SI.3). Video 1. Transfer of the Al film nanostructured with a nanohole array from a polycarbonate CD surface onto a Scotch tape; Video 2. Opto-mechanical electrostatics-based sensor: electrical attraction. Video 3. Opto-mechanical electrostatics-based sensor: electrical repulsion. See DOI: 10.1039/c4nr06271j

Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program. II. Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd, and Eu

NASA Astrophysics Data System (ADS)

Delgado Mena, E.; Tsantaki, M.; Adibekyan, V. Zh.; Sousa, S. G.; Santos, N. C.; González Hernández, J. I.; Israelian, G.

2017-10-01

Aims: To understand the formation and evolution of the different stellar populations within our Galaxy it is essential to combine detailed kinematical and chemical information for large samples of stars. The aim of this work is to explore the chemical abundances of neutron capture elements which are a product of different nucleosynthesis processes taking place in diverse objects in the Galaxy, such as massive stars, asymptotic giant branch (AGB) stars and supernovae (SNe) explosions. Methods: We derive chemical abundances of Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd, and Eu for a large sample of more than 1000 FGK dwarf stars with high-resolution (R 115 000) and high-quality spectra from the HARPS-GTO program. The abundances are derived by a standard local thermodynamic equilibrium (LTE) analysis using measured equivalent widths (EWs) injected to the code MOOG and a grid of Kurucz ATLAS9 atmospheres. Results: We find that thick disc stars are chemically disjunct for Zn and Eu and also show on average higher Zr but lower Ba and Y than the thin disc stars. We also discovered that the previously identified high-α metal-rich population is also enhanced in Cu, Zn, Nd, and Eu with respect to the thin disc but presents lower Ba and Y abundances on average, following the trend of thick disc stars towards higher metallities and further supporting the different chemical composition of this population. By making a qualitative comparison of O (pure α), Mg, Eu (pure r-process), and s-process elements we can distinguish between the contribution of the more massive stars (SNe II for α and r-process elements) and the lower mass stars (AGBs) whose contribution to the enrichment of the Galaxy is delayed, due to their longer lifetimes. The ratio of heavy-s to light-s elements of thin disc stars presents the expected behaviour (increasing towards lower metallicities) and can be explained by a major contribution of low-mass AGB stars for s-process production at disc metallicities. However, the opposite trend found for thick disc stars suggests that intermediate-mass AGB stars play an important role in the enrichment of the gas from where these stars formed. Previous works in the literature also point to a possible primary production of light-s elements at low metallicities to explain this trend. Finally, we also find an enhancement of light-s elements in the thin disc at super-solar metallicities which could be caused by the contribution of metal-rich AGB stars. Conclusions: This work proves the utility of homogeneous and high-quality data of modest sample sizes. We find some interesting trends that might help to differentiate thin and thick disc population (such as [Zn/Fe] and [Eu/Fe] ratios) and that can also provide useful constraints for Galactic chemical evolution models of the different populations in the Galaxy. Based on observations collected at the La Silla Observatory, ESO (Chile), with the HARPS spectrograph at the 3.6 m ESO telescope (ESO runs ID 72.C—0488, 082.C—0212, and 085.C—0063).Full Tables 1 and 3 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/606/A94

CDS - Database Administrator's Guide

NASA Astrophysics Data System (ADS)

Day, J. P.

This guide aims to instruct the CDS database administrator in: o The CDS file system. o The CDS index files. o The procedure for assimilating a new CDS tape into the database. It is assumed that the administrator has read SUN/79.

Comparison of Computer-based Clinical Decision Support Systems and Content for Diabetes Mellitus.

PubMed

Kantor, M; Wright, A; Burton, M; Fraser, G; Krall, M; Maviglia, S; Mohammed-Rajput, N; Simonaitis, L; Sonnenberg, F; Middleton, B

2011-01-01

Computer-based clinical decision support (CDS) systems have been shown to improve quality of care and workflow efficiency, and health care reform legislation relies on electronic health records and CDS systems to improve the cost and quality of health care in the United States; however, the heterogeneity of CDS content and infrastructure of CDS systems across sites is not well known. We aimed to determine the scope of CDS content in diabetes care at six sites, assess the capabilities of CDS in use at these sites, characterize the scope of CDS infrastructure at these sites, and determine how the sites use CDS beyond individual patient care in order to identify characteristics of CDS systems and content that have been successfully implemented in diabetes care. We compared CDS systems in six collaborating sites of the Clinical Decision Support Consortium. We gathered CDS content on care for patients with diabetes mellitus and surveyed institutions on characteristics of their site, the infrastructure of CDS at these sites, and the capabilities of CDS at these sites. The approach to CDS and the characteristics of CDS content varied among sites. Some commonalities included providing customizability by role or user, applying sophisticated exclusion criteria, and using CDS automatically at the time of decision-making. Many messages were actionable recommendations. Most sites had monitoring rules (e.g. assessing hemoglobin A1c), but few had rules to diagnose diabetes or suggest specific treatments. All sites had numerous prevention rules including reminders for providing eye examinations, influenza vaccines, lipid screenings, nephropathy screenings, and pneumococcal vaccines. Computer-based CDS systems vary widely across sites in content and scope, but both institution-created and purchased systems had many similar features and functionality, such as integration of alerts and reminders into the decision-making workflow of the provider and providing messages that are actionable recommendations.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brookhaven National Laboratory

Brookhaven National Laboratory (BNL) prepares an annual Site Environmental Report (SER) in accordance with DOE Order 231.1A, Environment, Safety and Health Reporting of the U.S. Department of Energy. The report is written to inform the public, regulators, employees, and other stakeholders of the Laboratory's environmental performance during the calendar year in review. Volume I of the SER summarizes environmental data; environmental management performance; compliance with applicable DOE, federal, state, and local regulations; and performance in restoration and surveillance monitoring programs. BNL has prepared annual SERs since 1971 and has documented nearly all of its environmental history since the Laboratory's inceptionmore » in 1947. Volume II of the SER, the Groundwater Status Report, also is prepared annually to report on the status of and evaluate the performance of groundwater treatment systems at the Laboratory. Volume II includes detailed technical summaries of groundwater data and its interpretation, and is intended for internal BNL users, regulators, and other technically oriented stakeholders. A brief summary of the information contained in Volume II is included in this volume in Chapter 7, Groundwater Protection. Both reports are available in print and as downloadable files on the BNL web page at http://www.bnl.gov/ewms/ser/. An electronic version on compact disc is distributed with each printed report. In addition, a summary of Volume I is prepared each year to provide a general overview of the report, and is distributed with a compact disc containing the full report.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ratel,K.

Brookhaven National Laboratory (BNL) prepares an annual Site Environmental Report (SER) in accordance with DOE Order 231.1A, Environment, Safety and Health Reporting of the U.S. Department of Energy. The report is written to inform the public, regulators, employees, and other stakeholders of the Laboratory's environmental performance during the calendar year in review. Volume I of the SER summarizes environmental data; environmental management performance; compliance with applicable DOE, federal, state, and local regulations; and performance in restoration and surveillance monitoring programs. BNL has prepared annual SERs since 1971 and has documented nearly all of its environmental history since the Laboratory's inceptionmore » in 1947. Volume II of the SER, the Groundwater Status Report, also is prepared annually to report on the status of and evaluate the performance of groundwater treatment systems at the Laboratory. Volume II includes detailed technical summaries of groundwater data and its interpretation, and is intended for internal BNL users, regulators, and other technically oriented stakeholders. A brief summary of the information contained in Volume II is included in this volume in Chapter 7, Groundwater Protection. Both reports are available in print and as downloadable files on the BNL web page at http://www.bnl.gov/ewms/ser/. An electronic version on compact disc is distributed with each printed report. In addition, a summary of Volume I is prepared each year to provide a general overview of the report, and is distributed with a compact disc containing the-length report.« less

Star formation properties of Hickson Compact Groups based on deep Hα imaging

NASA Astrophysics Data System (ADS)

Eigenthaler, Paul; Ploeckinger, Sylvia; Verdugo, Miguel; Ziegler, Bodo

2015-08-01

We present deep Hα imaging of seven Hickson Compact Groups (HCGs) using the 4.1-m Southern Astrophysics Research (SOAR) Telescope. The high spatial resolution of the observations allows us to study both the integrated star formation properties of the main galaxies as well as the 2D distribution of star-forming knots in the faint tidal arms that form during interactions between the individual galaxies. We derive star formation rates and stellar masses for group members and discuss their position relative to the main sequence of star-forming galaxies. Despite the existence of tidal features within the galaxy groups, we do not find any indication for enhanced star formation in the selected sample of HCGs. We study azimuthally averaged Hα profiles of the galaxy discs and compare them with the g' and r' surface brightness profiles. We do not find any truncated galaxy discs but reveal that more massive galaxies show a higher light concentration in Hα than less massive ones. We also see that galaxies that show a high light concentration in r', show a systematic higher light concentration in Hα. Tidal dwarf galaxy (TDG) candidates have been previously detected in R-band images for two groups in our sample but we find that most of them are likely background objects as they do not show any emission in Hα. We present a new TDG candidate at the tip of the tidal tail in HCG 91.

A Colorimetric Enzyme-Linked Immunosorbent Assay (ELISA) Detection Platform for a Point-of-Care Dengue Detection System on a Lab-on-Compact-Disc

PubMed Central

Thiha, Aung; Ibrahim, Fatimah

2015-01-01

The enzyme-linked Immunosorbent Assay (ELISA) is the gold standard clinical diagnostic tool for the detection and quantification of protein biomarkers. However, conventional ELISA tests have drawbacks in their requirement of time, expensive equipment and expertise for operation. Hence, for the purpose of rapid, high throughput screening and point-of-care diagnosis, researchers are miniaturizing sandwich ELISA procedures on Lab-on-a-Chip and Lab-on-Compact Disc (LOCD) platforms. This paper presents a novel integrated device to detect and interpret the ELISA test results on a LOCD platform. The system applies absorption spectrophotometry to measure the absorbance (optical density) of the sample using a monochromatic light source and optical sensor. The device performs automated analysis of the results and presents absorbance values and diagnostic test results via a graphical display or via Bluetooth to a smartphone platform which also acts as controller of the device. The efficacy of the device was evaluated by performing dengue antibody IgG ELISA on 64 hospitalized patients suspected of dengue. The results demonstrate high accuracy of the device, with 95% sensitivity and 100% specificity in detection when compared with gold standard commercial ELISA microplate readers. This sensor platform represents a significant step towards establishing ELISA as a rapid, inexpensive and automatic testing method for the purpose of point-of-care-testing (POCT) in resource-limited settings. PMID:25993517

Facile synthesis and luminescence characteristics of high-quality CdS: Eu/ZnS core/shell nanocrystals with biocompatibility.

PubMed

Zhang, Kexin; Zhang, Rui; Yu, Yaxin; Sun, Shuqing

2012-04-01

In this paper, we report a facile method to synthesize high quality CdS: Eu nanocrystals (NCs) and CdS: Eu/ZnS NCs with strong photoluminescence (PL). The influence of various experimental variables including the concentration of Eu3+ ions, the reaction time and the reaction temperature were investigated systematically. In addition, the PL properties of CdS: Eu NCs exhibited pH sensitive. Under the acid condition, pH value of the CdS: Eu NCs solution played an important role in determining PL emission intensity. However, under the alkaline condition, the obtained CdS: Eu NCs exhibited a tunable PL emission wavelength (from 490 nm to 610 nm) when pH value was adjusted from pH 7 to 10. After coating with ZnS shell, the CdS: Eu/ZnS NCs showed enhanced PL intensity compare with one of the CdS: Eu NCs. The CdS: Eu NCs and CdS: Eu/ZnS NCs were characterized by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). In addition, the biocompatibility of these NCs was measured by hemolytic test, which indicated that CdS: Eu/ZnS NCs were more biocompatible than CdS: Eu NCs at the same conditions. It can be expected that CdS: Eu/ZnS NCs are promising biolabeling materials.

Detection of high Lyman continuum leakage from four low-redshift compact star-forming galaxies

NASA Astrophysics Data System (ADS)

Izotov, Y. I.; Schaerer, D.; Thuan, T. X.; Worseck, G.; Guseva, N. G.; Orlitová, I.; Verhamme, A.

2016-10-01

Following our first detection reported in Izotov et al., we present the detection of Lyman continuum (LyC) radiation of four other compact star-forming galaxies observed with the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope. These galaxies, at redshifts of z ˜ 0.3, are characterized by high emission-line flux ratios [O III] λ5007/[O II] λ3727 ≳ 5. The escape fractions of the LyC radiation fesc(LyC) in these galaxies are in the range of ˜6-13 per cent, the highest values found so far in low-redshift star-forming galaxies. Narrow double-peaked Ly α emission lines are detected in the spectra of all four galaxies, compatible with predictions for LyC leakers. We find escape fractions of Ly α, fesc(Ly α) ˜ 20-40 per cent, among the highest known for Ly α emitting galaxies. Surface brightness profiles produced from the COS acquisition images reveal bright star-forming regions in the centre and exponential discs in the outskirts with disc scalelengths α in the range ˜0.6-1.4 kpc. Our galaxies are characterized by low metallicity, ˜1/8-1/5 solar, low stellar mass ˜(0.2-4) × 109 M⊙, high star formation rates, SFR ˜ 14-36 M⊙ yr-1, and high SFR densities, Σ ˜ 2-35 M⊙ yr-1 kpc-2. These properties are comparable to those of high-redshift star-forming galaxies. Finally, our observations, combined with our first detection reported in Izotov et al., reveal that a selection for compact star-forming galaxies showing high [O III] λ5007/[O II] λ3727 ratios appears to pick up very efficiently sources with escaping LyC radiation: all five of our selected galaxies are LyC leakers.

Nitrogen and sulfur co-doped carbon dots with strong blue luminescence

NASA Astrophysics Data System (ADS)

Ding, Hui; Wei, Ji-Shi; Xiong, Huan-Ming

2014-10-01

Sulfur-doped carbon dots (S-CDs) with a quantum yield (QY) of 5.5% and nitrogen, sulfur co-doped carbon dots (N,S-CDs) with a QY of 54.4% were synthesized, respectively, via the same hydrothermal route using α-lipoic acid as the carbon source. The obtained S-CDs and N,S-CDs had similar sizes but different optical features. The QY of N,S-CDs was gradually enhanced when extending the reaction time to increase the nitrogen content. After careful characterization of these CDs, the doped nitrogen element was believed to be in the form of C&z.dbd;N and C-N bonds which enhanced the fluorescence efficiency significantly. Meanwhile, the co-doped sulfur element was found to be synergistic for nitrogen doping in N,S-CDs. The optimal N,S-CDs were successfully employed as good multicolor cell imaging probes due to their fine dispersion in water, excitation-dependent emission, excellent fluorescence stability and low toxicity. Besides, such N,S-CDs showed a wide detection range and excellent accuracy as fluorescent sensors for Fe3+ ions.Sulfur-doped carbon dots (S-CDs) with a quantum yield (QY) of 5.5% and nitrogen, sulfur co-doped carbon dots (N,S-CDs) with a QY of 54.4% were synthesized, respectively, via the same hydrothermal route using α-lipoic acid as the carbon source. The obtained S-CDs and N,S-CDs had similar sizes but different optical features. The QY of N,S-CDs was gradually enhanced when extending the reaction time to increase the nitrogen content. After careful characterization of these CDs, the doped nitrogen element was believed to be in the form of C&z.dbd;N and C-N bonds which enhanced the fluorescence efficiency significantly. Meanwhile, the co-doped sulfur element was found to be synergistic for nitrogen doping in N,S-CDs. The optimal N,S-CDs were successfully employed as good multicolor cell imaging probes due to their fine dispersion in water, excitation-dependent emission, excellent fluorescence stability and low toxicity. Besides, such N,S-CDs showed a wide detection range and excellent accuracy as fluorescent sensors for Fe3+ ions. Electronic supplementary information (ESI) available: Experimental details and comparable characterization of three kinds of CDs. See DOI: 10.1039/c4nr04267k

Evaluation of children with lymphatic malformations of the head and neck using the Cologne Disease Score.

PubMed

Wiegand, Susanne; Eivazi, Behfar; Zimmermann, Annette P; Sesterhenn, Andreas M; Werner, Jochen A

2009-07-01

To assess the disease-related impairments of children with lymphatic malformations of the head and neck and their changes after therapy using the Cologne Disease Score (CDS). 29 children with lymphatic malformations of the head and neck were evaluated regarding their symptoms before and after therapy using the CDS. The Wilcoxon test for dependent groups was used to compare the CDS at initial visit before treatment and last visit after treatment. The CDS of patients belonging to the moderate (initial CDS: more than eight points) and advanced disease group (initial CDS: five, six or seven points) significantly increased after therapy while the patients in the severe disease group (initial CDS: lower than four points) showed no significant improvement of CDS. Patients with stage IV and especially stage V lymphatic malformations according to de Serres showed considerably lower pre- and posttherapeutic CDS levels than those of stage I and II. The visual impairment is not mapped by the CDS, therefore item vision should be added to the CDS to make an evaluation of all lymphatic malformations of the head and neck possible. The present series could show that especially patients with a moderate or advanced disease according to the CDS may profit from therapeutic interventions.

Fully integrated lab-on-a-disc for nucleic acid analysis of food-borne pathogens.

PubMed

Kim, Tae-Hyeong; Park, Juhee; Kim, Chi-Ju; Cho, Yoon-Kyoung

2014-04-15

This paper describes a micro total analysis system for molecular analysis of Salmonella, a major food-borne pathogen. We developed a centrifugal microfluidic device, which integrated the three main steps of pathogen detection, DNA extraction, isothermal recombinase polymerase amplification (RPA), and detection, onto a single disc. A single laser diode was utilized for wireless control of valve actuation, cell lysis, and noncontact heating in the isothermal amplification step, thereby yielding a compact and miniaturized system. To achieve high detection sensitivity, rare cells in large volumes of phosphate-buffered saline (PBS) and milk samples were enriched before loading onto the disc by using antibody-coated magnetic beads. The entire procedure, from DNA extraction through to detection, was completed within 30 min in a fully automated fashion. The final detection was carried out using lateral flow strips by direct visual observation; detection limit was 10 cfu/mL and 10(2) cfu/mL in PBS and milk, respectively. Our device allows rapid molecular diagnostic analysis and does not require specially trained personnel or expensive equipment. Thus, we expect that it would have an array of potential applications, including in the detection of food-borne pathogens, environmental monitoring, and molecular diagnostics in resource-limited settings.

One pot synthesis of highly luminescent polyethylene glycol anchored carbon dots functionalized with a nuclear localization signal peptide for cell nucleus imaging.

PubMed

Yang, Lei; Jiang, Weihua; Qiu, Lipeng; Jiang, Xuewei; Zuo, Daiying; Wang, Dongkai; Yang, Li

2015-04-14

Strong blue fluorescent polyethylene glycol (PEG) anchored carbon nitride dots (CDs@PEG) with a high quantum yield (QY) of 75.8% have been synthesized by a one step hydrothermal treatment. CDs with a diameter of ca. 6 nm are well dispersed in water and present a graphite-like structure. Photoluminescence (PL) studies reveal that CDs display excitation-dependent behavior and are stable under various test conditions. Based on the as-prepared CDs, we designed novel cell nucleus targeting imaging carbon dots functionalized with a nuclear localization signal (NLS) peptide. The favourable biocompatibilities of CDs and NLS modified CDs (NLS-CDs) are confirmed by in vitro cytotoxicity assays. Importantly, intracellular localization experiments in MCF7 and A549 cells demonstrate that NLS-CDs could be internalized in the nucleus and show blue light, which indicates that CDs may serve as cell nucleus imaging probes.

Fabrication of CDs/CdS-TiO2 ternary nano-composites for photocatalytic degradation of benzene and toluene under visible light irradiation

NASA Astrophysics Data System (ADS)

Wang, Meng; Hua, Jianhao; Yang, Yaling

2018-06-01

An efficient cadmium sulfide quantum-dots (CdS QDs) and carbon dots (CDs) modified TiO2 photocatalyst (CdS/CDs-TiO2) was successfully fabricated. The as-prepared ternary nano-composites simultaneously improved the photo-corrosion of CdS and amplified its photocatalytic activity. The introduction of CdS QDs and CDs could enhance more absorbance of light, prevent the undesirable electron/hole recombination, and promote charge separation, which was important for the continuous formation of rad OH and rad O2- radicals. When the optimal mass ratio of CdS QDs to CDs was 3:1, above 90% degradation efficiencies were achieved for benzene within 1 h and toluene in 2 h, while that of pure TiO2 (P25), CdS QDs-TiO2, CDs-TiO2 nano-composites was around 15%. Owing to the symmetric structure and conjugation of methyl with benzene ring, the degradation of toluene was more difficult than benzene to carry on. The new fabricated nano-composites showed good prospective application of cleaning up refractory pollutants and the resource utilization.

Green preparation of carbon dots with papaya as carbon source for effective fluorescent sensing of Iron (III) and Escherichia coli.

PubMed

Wang, Ning; Wang, Yiting; Guo, Tingting; Yang, Ting; Chen, Mingli; Wang, Jianhua

2016-11-15

A simple one-step hydrothermal green approach was reported for the preparation of carbon dots (CDs) without any further decoration or modification with papaya powder as natural carbon source. In this economical and eco-friendly system, deionized water or 90% ethanol was used as solvent to produce water-soluble or ethanol-soluble CDs, respectively, termed as W-CDs and E-CDs. The quantum yield (QY) for W-CDs was 18.98%, while that for E-CDs was 18.39%. The potentials of the prepared carbon dots toward diverse applications were thoroughly investigated. W-CDs and E-CDs provide promising probes for fluorescence detection of Fe(3+), offering limits of detection of 0.48μmolL(-1) and 0.29μmolL(-1), respectively. W-CDs was further demonstrated to be a promising probe for fluorescence sensing of Escherichia coli O157: H7, along with a limit of detection of 9.5×10(4)cfumL(-1). Meanwhile, both W-CDs and E-CDs exhibit favorable biocompatibility, and demonstrated to be efficient for Hela cell imaging. Copyright © 2016 Elsevier B.V. All rights reserved.

Highly Efficient Photocatalytic Hydrogen Production of Flower-like Cadmium Sulfide Decorated by Histidine

PubMed Central

Wang, Qizhao; Lian, Juhong; Li, Jiajia; Wang, Rongfang; Huang, Haohao; Su, Bitao; Lei, Ziqiang

2015-01-01

Morphology-controlled synthesis of CdS can significantly enhance the efficiency of its photocatalytic hydrogen production. In this study, a novel three-dimensional (3D) flower-like CdS is synthesized via a facile template-free hydrothermal process using Cd(NO3)2•4H2O and thiourea as precursors and L-Histidine as a chelating agent. The morphology, crystal phase, and photoelectrochemical performance of the flower-like CdS and pure CdS nanocrystals are carefully investigated via various characterizations. Superior photocatalytic activity relative to that of pure CdS is observed on the flower-like CdS photocatalyst under visible light irradiation, which is nearly 13 times of pure CdS. On the basis of the results from SEM studies and our analysis, a growth mechanism of flower-like CdS is proposed by capturing the shape evolution. The imidazole ring of L-Histidine captures the Cd ions from the solution, and prevents the growth of the CdS nanoparticles. Furthermore, the photocatalytic contrast experiments illustrate that the as-synthesized flower-like CdS with L-Histidine is more stable than CdS without L-Histidine in the hydrogen generation. PMID:26337119

Highly Efficient Photocatalytic Hydrogen Production of Flower-like Cadmium Sulfide Decorated by Histidine

NASA Astrophysics Data System (ADS)

Wang, Qizhao; Lian, Juhong; Li, Jiajia; Wang, Rongfang; Huang, Haohao; Su, Bitao; Lei, Ziqiang

2015-09-01

Morphology-controlled synthesis of CdS can significantly enhance the efficiency of its photocatalytic hydrogen production. In this study, a novel three-dimensional (3D) flower-like CdS is synthesized via a facile template-free hydrothermal process using Cd(NO3)2•4H2O and thiourea as precursors and L-Histidine as a chelating agent. The morphology, crystal phase, and photoelectrochemical performance of the flower-like CdS and pure CdS nanocrystals are carefully investigated via various characterizations. Superior photocatalytic activity relative to that of pure CdS is observed on the flower-like CdS photocatalyst under visible light irradiation, which is nearly 13 times of pure CdS. On the basis of the results from SEM studies and our analysis, a growth mechanism of flower-like CdS is proposed by capturing the shape evolution. The imidazole ring of L-Histidine captures the Cd ions from the solution, and prevents the growth of the CdS nanoparticles. Furthermore, the photocatalytic contrast experiments illustrate that the as-synthesized flower-like CdS with L-Histidine is more stable than CdS without L-Histidine in the hydrogen generation.

Highly Efficient Photocatalytic Hydrogen Production of Flower-like Cadmium Sulfide Decorated by Histidine.

PubMed

Wang, Qizhao; Lian, Juhong; Li, Jiajia; Wang, Rongfang; Huang, Haohao; Su, Bitao; Lei, Ziqiang

2015-09-04

Morphology-controlled synthesis of CdS can significantly enhance the efficiency of its photocatalytic hydrogen production. In this study, a novel three-dimensional (3D) flower-like CdS is synthesized via a facile template-free hydrothermal process using Cd(NO3)2•4H2O and thiourea as precursors and L-Histidine as a chelating agent. The morphology, crystal phase, and photoelectrochemical performance of the flower-like CdS and pure CdS nanocrystals are carefully investigated via various characterizations. Superior photocatalytic activity relative to that of pure CdS is observed on the flower-like CdS photocatalyst under visible light irradiation, which is nearly 13 times of pure CdS. On the basis of the results from SEM studies and our analysis, a growth mechanism of flower-like CdS is proposed by capturing the shape evolution. The imidazole ring of L-Histidine captures the Cd ions from the solution, and prevents the growth of the CdS nanoparticles. Furthermore, the photocatalytic contrast experiments illustrate that the as-synthesized flower-like CdS with L-Histidine is more stable than CdS without L-Histidine in the hydrogen generation.

Clinical decision support for genetically guided personalized medicine: a systematic review

PubMed Central

Welch, Brandon M

2013-01-01

Objective To review the literature on clinical decision support (CDS) for genetically guided personalized medicine (GPM). Materials and Methods MEDLINE and Embase were searched from 1990 to 2011. The manuscripts included were summarized, and notable themes and trends were identified. Results Following a screening of 3416 articles, 38 primary research articles were identified. Focal areas of research included family history-driven CDS, cancer management, and pharmacogenomics. Nine randomized controlled trials of CDS interventions for GPM were identified, seven of which reported positive results. The majority of manuscripts were published on or after 2007, with increased recent focus on genotype-driven CDS and the integration of CDS within primary clinical information systems. Discussion Substantial research has been conducted to date on the use of CDS to enable GPM. In a previous analysis of CDS intervention trials, the automatic provision of CDS as a part of routine clinical workflow had been identified as being critical for CDS effectiveness. There was some indication that CDS for GPM could potentially be effective without the CDS being provided automatically, but we did not find conclusive evidence to support this hypothesis. Conclusion To maximize the clinical benefits arising from ongoing discoveries in genetics and genomics, additional research and development is recommended for identifying how best to leverage CDS to bridge the gap between the promise and realization of GPM. PMID:22922173

Absence of collagen IX accelerates hypertrophic differentiation in the embryonic mouse spine through a disturbance of the Ihh-PTHrP feedback loop.

PubMed

Kamper, Matthias; Paulsson, Mats; Zaucke, Frank

2017-02-01

Collagen IX (Col IX) is a component of the cartilage extracellular matrix and contributes to its structural integrity. Polymorphisms in the genes encoding the Col IX ɑ2- and ɑ3-chains are associated with early onset of disc degeneration. Col IX-deficient mice already display changes in the spine at the newborn stage and premature disc degeneration starting at 6 months of age. To determine the role of Col IX in early spine development and to identify molecular mechanisms underlying disc degeneration, the embryonic development of the spine was analyzed in Col IX -/- mice. Histological staining was used to show tissue morphology at different time points. Localization of extracellular matrix proteins as well as components of signaling pathways were analyzed by immunohistochemistry. Developing vertebral bodies of Col IX -/- mice were smaller and already appeared more compact at E12.5. At E15.5, vertebral bodies of Col IX -/- mice revealed an increased number of hypertrophic chondrocytes as well as enhanced staining for the terminal differentiation markers alkaline phosphatase and collagen X. This correlates with an imbalance in the Ihh-PTHrP signaling pathway at this time point, reflected by an increase of Ihh and a concomitant decrease of PTHrP expression. An accelerated hypertrophic differentiation caused by a disturbed Ihh-PTHrP signaling pathway may lead to a higher bone mineral density in the vertebral bodies of newborn Col IX -/- mice and, as a result, to the early onset of disc degeneration.

A low-luminosity soft state in the short-period black hole X-ray binary Swift J1753.5-0127

NASA Astrophysics Data System (ADS)

Shaw, A. W.; Gandhi, P.; Altamirano, D.; Uttley, P.; Tomsick, J. A.; Charles, P. A.; Fürst, F.; Rahoui, F.; Walton, D. J.

2016-05-01

We present results from the spectral fitting of the candidate black hole X-ray binary Swift J1753.5-0127 in an accretion state previously unseen in this source. We fit the 0.7-78 keV spectrum with a number of models, however the preferred model is one of a multitemperature disc with an inner disc temperature kTin = 0.252 ± 0.003 keV scattered into a steep power-law with photon index Γ =6.39^{+0.08}_{-0.02} and an additional hard power-law tail (Γ = 1.79 ± 0.02). We report on the emergence of a strong disc-dominated component in the X-ray spectrum and we conclude that the source has entered the soft state for the first time in its ˜10 yr prolonged outburst. Using reasonable estimates for the distance to the source (3 kpc) and black hole mass (5 M⊙), we find the unabsorbed luminosity (0.1-100 keV) to be ≈0.60 per cent of the Eddington luminosity, making this one of the lowest luminosity soft states recorded in X-ray binaries. We also find that the accretion disc extended towards the compact object during its transition from hard to soft, with the inner radius estimated to be R_{in}=28.0^{+0.7}_{-0.4} R_g or ˜12Rg, dependent on the boundary condition chosen, assuming the above distance and mass, a spectral hardening factor f = 1.7 and a binary inclination I = 55°.

Optical Laser Technology, Specifically CD-ROM (Compact Disc - Read Only Memory) and Its Application to the Storage and Retrieval of Information.

DTIC Science & Technology

1987-06-01

RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARIS-1963-A gT~ ILE CE NAVAL POSTGRADUATE SCHOOL Monterey, California ;.CTE THESIS uEOIB OPTICAL LASER... usedin it xr~awsd SECURITY CLASSIFICATION Of ’-IS5 PACTF All other edtoni are obsolete 0’ NC TA? 7RI UNCLASSIFIED S3CUNTY CLASSIFICATION OF THIS PA69 (WhI...where the resulting mixture of text, color graphics, animation , and audio can be achieved. This technology is in the formative stages, however it is

Clinical decision support alert malfunctions: analysis and empirically derived taxonomy.

PubMed

Wright, Adam; Ai, Angela; Ash, Joan; Wiesen, Jane F; Hickman, Thu-Trang T; Aaron, Skye; McEvoy, Dustin; Borkowsky, Shane; Dissanayake, Pavithra I; Embi, Peter; Galanter, William; Harper, Jeremy; Kassakian, Steve Z; Ramoni, Rachel; Schreiber, Richard; Sirajuddin, Anwar; Bates, David W; Sittig, Dean F

2018-05-01

To develop an empirically derived taxonomy of clinical decision support (CDS) alert malfunctions. We identified CDS alert malfunctions using a mix of qualitative and quantitative methods: (1) site visits with interviews of chief medical informatics officers, CDS developers, clinical leaders, and CDS end users; (2) surveys of chief medical informatics officers; (3) analysis of CDS firing rates; and (4) analysis of CDS overrides. We used a multi-round, manual, iterative card sort to develop a multi-axial, empirically derived taxonomy of CDS malfunctions. We analyzed 68 CDS alert malfunction cases from 14 sites across the United States with diverse electronic health record systems. Four primary axes emerged: the cause of the malfunction, its mode of discovery, when it began, and how it affected rule firing. Build errors, conceptualization errors, and the introduction of new concepts or terms were the most frequent causes. User reports were the predominant mode of discovery. Many malfunctions within our database caused rules to fire for patients for whom they should not have (false positives), but the reverse (false negatives) was also common. Across organizations and electronic health record systems, similar malfunction patterns recurred. Challenges included updates to code sets and values, software issues at the time of system upgrades, difficulties with migration of CDS content between computing environments, and the challenge of correctly conceptualizing and building CDS. CDS alert malfunctions are frequent. The empirically derived taxonomy formalizes the common recurring issues that cause these malfunctions, helping CDS developers anticipate and prevent CDS malfunctions before they occur or detect and resolve them expediently.

Efficient synthesis of highly fluorescent nitrogen-doped carbon dots for cell imaging using unripe fruit extract of Prunus mume

NASA Astrophysics Data System (ADS)

Atchudan, Raji; Edison, Thomas Nesakumar Jebakumar Immanuel; Sethuraman, Mathur Gopalakrishnan; Lee, Yong Rok

2016-10-01

Highly fluorescent nitrogen-doped carbon dots (N-CDs) were synthesized using the extract of unripe Prunus mume (P. mume) fruit by a simple one step hydrothermal-carbonization method. The N-CDs were synthesized at different pH ranges, 2.3, 5, 7, and 9. The pH of the P. mume extract was adjusted using an aqueous ammonia solution (25%). The optical properties of N-CDs were examined by UV-vis and fluorescence spectroscopy. The N-CDs synthesized at pH 9 emitted high fluorescence intensity compared to other obtained N-CDs. The N-CDs synthesized at pH 9 was further characterized by high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and Fourier transform-infra red (FT-IR) spectroscopy. HR-TEM showed that the average size of the synthesized N-CDs was approximately 9 nm and the interlayer distance was 0.21 nm, which was validated by XRD. The graphitic nature of the synthesized N-CDs were confirmed by Raman spectroscopy. XPS and FT-IR spectroscopy confirmed the doping of the nitrogen moiety over the synthesized CDs. The synthesized nitrogen doped CDs (N-CDs) were low toxicity and were used as a staining probe for fluorescence cell imaging.

Standard practices for computerized clinical decision support in community hospitals: a national survey

PubMed Central

McCormack, James L; Sittig, Dean F; Wright, Adam; McMullen, Carmit; Bates, David W

2012-01-01

Objective Computerized provider order entry (CPOE) with clinical decision support (CDS) can help hospitals improve care. Little is known about what CDS is presently in use and how it is managed, however, especially in community hospitals. This study sought to address this knowledge gap by identifying standard practices related to CDS in US community hospitals with mature CPOE systems. Materials and Methods Representatives of 34 community hospitals, each of which had over 5 years experience with CPOE, were interviewed to identify standard practices related to CDS. Data were analyzed with a mix of descriptive statistics and qualitative approaches to the identification of patterns, themes and trends. Results This broad sample of community hospitals had robust levels of CDS despite their small size and the independent nature of many of their physician staff members. The hospitals uniformly used medication alerts and order sets, had sophisticated governance procedures for CDS, and employed staff to customize CDS. Discussion The level of customization needed for most CDS before implementation was greater than expected. Customization requires skilled individuals who represent an emerging manpower need at this type of hospital. Conclusion These results bode well for robust diffusion of CDS to similar hospitals in the process of adopting CDS and suggest that national policies to promote CDS use may be successful. PMID:22707744

Use of Mobile Clinical Decision Support Software by Junior Doctors at a UK Teaching Hospital: Identification and Evaluation of Barriers to Engagement.

PubMed

Patel, Rakesh; Green, William; Shahzad, Muhammad Waseem; Larkin, Chris

2015-08-13

Clinical decision support (CDS) tools improve clinical diagnostic decision making and patient safety. The availability of CDS to health care professionals has grown in line with the increased prevalence of apps and smart mobile devices. Despite these benefits, patients may have safety concerns about the use of mobile devices around medical equipment. This research explored the engagement of junior doctors (JDs) with CDS and the perceptions of patients about their use. There were three objectives for this research: (1) to measure the actual usage of CDS tools on mobile devices (mCDS) by JDs, (2) to explore the perceptions of JDs about the drivers and barriers to using mCDS, and (3) to explore the perceptions of patients about the use of mCDS. This study used a mixed-methods approach to study the engagement of JDs with CDS accessed through mobile devices. Usage data were collected on the number of interactions by JDs with mCDS. The perceived drivers and barriers for JDs to using CDS were then explored by interviews. Finally, these findings were contrasted with the perception of patients about the use of mCDS by JDs. Nine of the 16 JDs made a total of 142 recorded interactions with the mCDS over a 4-month period. Only 27 of the 114 interactions (24%) that could be categorized as on-shift or off-shift occurred on-shift. Eight individual, institutional, and cultural barriers to engagement emerged from interviews with the user group. In contrast to reported cautions and concerns about the impact of clinicians' use of mobile phone on patient health and safety, patients had positive perceptions about the use of mCDS. Patients reported positive perceptions toward mCDS. The usage of mCDS to support clinical decision making was considered to be positive as part of everyday clinical practice. The degree of engagement was found to be limited due to a number of individual, institutional, and cultural barriers. The majority of mCDS engagement occurred outside of the workplace. Further research is required to verify these findings and assess their implications for future policy and practice.

[A gearing mechanism with 4 degrees of freedom for robotic applications in medicine].

PubMed

Pott, P; Weiser, P; Scharf, H P; Schwarz, M

2004-06-01

Applications in robot-aided surgery are currently based on modifications of manipulators used in industrial manufacturing processes. In this paper we describe novel rotatory kinematics for a manipulator, specially developed for deployment in robot-aided surgery. The construction of the gearing mechanism used for the positioning and orientation of a linkage point is described. Forward and inverse kinematics were calculated, and a constructive solution proposed. The gearing mechanism is based on two disk systems, each of which consists of two opposing rotatable discs. The construction was designed in such a way that the linkage point can be positioned freely anywhere within the mechanism's range of motion. The kinematics thus permits an x-y-positioning via rotating movements only. The spatial arrangement of two of such disc systems permits movements in four degrees of freedom (DOF). The construction is compact, but can be further miniaturized, is flexible and manufacturing costs are low. On the basis of this mechanical concept a new, small automated manipulator for surgical application will be developed.

Recent progress of obliquely deposited thin films for industrial applications

NASA Astrophysics Data System (ADS)

Suzuki, Motofumi; Itoh, Tadayoshi; Taga, Yasunori

1999-06-01

More than 10 years ago, birefringent films of metal oxides were formed by oblique vapor deposition and investigated with a view of their application to optical retardation plates. The retardation function of the films was explained in terms of the birefringence caused by the characteristic anisotropic nanostructure inside the films. These films are now classified in the genre of the so-called sculptured thin films. However, the birefringent films thus prepared are not yet industrialized even now due to the crucial lack of the durability and the yield of products. In this review paper, we describe the present status of application process of the retardation films to the information systems such as compact disc and digital versatile disc devices with a special emphasis on the uniformity of retardation properties in a large area and the stability of the optical properties of the obliquely deposited thin films. Finally, further challenges for wide application of the obliquely deposited thin films are also discussed.

A bifacial quantum dot-sensitized solar cell with all-cadmium sulfide photoanode

NASA Astrophysics Data System (ADS)

Ma, Chunqing; Tang, Qunwei; Liu, Danyang; Zhao, Zhiyuan; He, Benlin; Chen, Haiyan; Yu, Liangmin

2015-02-01

Pursuit of a high power conversion efficiency and reduction of electricity-generation cost has been a persistent objective for quantum dot-sensitized solar cells (QDSSCs). We present here the fabrication of a QDSSC comprising a nanoflower-structured CdS anode, a liquid electrolyte having S2-/Sn2- redox couples, and a transparent CoSe counter electrode. Nanoflower-structured CdS anodes are prepared by a successive ionic layer adsorption and reaction (SILAR) method and subsequently hydrothermal strategy free of any surfactant or template. The CdS nanoparticles synthesized by a SILAR method act as "seed crystal" for growth of CdS nanoflowers. The average electron lifetime is markedly elevated in nanoflower-structured CdS anode in comparison with CdS nanoparticle or nanoporous CdS microsphere anode. Herein, we study the effect of synthesis method on CdS morphology and solar cell's photovoltaic performance, showing a power conversion efficiency of 1.67% and 1.17% for nanoflower-structured CdS QDSSC under front and rear irradiations, respectively.

Implementation Pearls from a New Guidebook on Improving Medication Use and Outcomes with Clinical Decision Support

PubMed Central

Sirajuddin, Anwar M; Osheroff, Jerome A.; Sittig, Dean F.; Chuo, John; Velasco, Ferdinand; Collins, David A.

2012-01-01

Effective clinical decision support (CDS) is essential for addressing healthcare performance improvement imperatives, but care delivery organizations (CDO) typically struggle with CDS deployment. Ensuring safe and effective medication delivery to patients is a central focus of CDO performance improvement efforts, and this article provides an overview of best-practice strategies for applying CDS to these goals. The strategies discussed are drawn from a new guidebook, co-published and co-sponsored by more than a dozen leading organizations. Developed by scores of CDS implementers and experts, the guidebook outlines key steps and success factors for applying CDS to medication management. A central thesis is that improving outcomes with CDS interventions requires that the CDS five rights be addressed successfully. That is, the interventions must deliver the right information, to the right person, in the right format, through the right channel, at the right point in workflow. This paper provides further details about these CDS five rights, and highlights other important strategies for successful CDS programs. PMID:19894486

Closed depressions in the European loess belt - Natural or anthropogenic origin?

NASA Astrophysics Data System (ADS)

Kołodyńska-Gawrysiak, Renata; Poesen, Jean

2017-07-01

Closed depressions (CDs) are typical geomorphological features of the loess belt in Europe. CDs have been reported in several regions of the European loess belt, where they are described as hollows, mardeles, wymoki, crovuri, bludtsa and zapadiny. The natural and anthropogenic origins of CDs are debated in literature. Moreover, no comprehensive review of the geomorphic properties or the evolution of these depressions exists. Therefore this paper reviews the characteristics of CDs in the European loess belt and attempts to better understand their genesis based on detailed case studies. The main morphometric features as well as sediment deposits within CDs in several sub-regions of Europe were analysed and compared. Morphometric properties of CDs from the West European and East European loess belt were investigated through a comparison of CDs from two representative regions, i.e. East Poland and Central Belgium. In both study areas, CDs under cropland are similar. However, a comparison of morphological features of CDs under forest, revealed clear differences, suggesting a different origin of CDs from both regions. Infilled sediments in CDs show various litho-genetical features in different regions of the European loess belt. The morphometric features, ages and stratigraphy of infillings clearly indicate that both anthropogenic and natural processes have shaped these landforms within the loess belt of Europe. CDs observed in Eastern Europe may have a very different origin than those documented in Western Europe. Detailed analysis of CDs in Poland and in neighbouring regions of East Europe, suggest that CDs are natural landforms: thermokarst, deflation and dissolution of loess are reported as probable genetic processes. In contrast, several studies in Western Europe indicate a dominant anthropogenic origin (i.e. digging of calcareous loess or marls, bomb and mining craters, collapse of underground limestone quarries), although CDs formed by natural processes (i.e. piping, dissolution of limestone and salt lenses below the loess cover) are reported as well. CDs act as important archives, allowing one to reconstruct both natural and anthropogenic processes operating in the past. As CDs store most sediments eroded within their catchment they provide ideal sediment traps to assess long-term erosion rates in these environments which have hitherto been under-researched. More research is needed to unravel the genesis and evolution of these depressions to better understand the importance of the Late Glacial and Holocene stages for the morphogenesis of the loess belt in Europe.

Intraoperative Clinical Decision Support for Anesthesia: A Narrative Review of Available Systems.

PubMed

Nair, Bala G; Gabel, Eilon; Hofer, Ira; Schwid, Howard A; Cannesson, Maxime

2017-02-01

With increasing adoption of anesthesia information management systems (AIMS), there is growing interest in utilizing AIMS data for intraoperative clinical decision support (CDS). CDS for anesthesia has the potential for improving quality of care, patient safety, billing, and compliance. Intraoperative CDS can range from passive and post hoc systems to active real-time systems that can detect ongoing clinical issues and deviations from best practice care. Real-time CDS holds the most promise because real-time alerts and guidance can drive provider behavior toward evidence-based standardized care during the ongoing case. In this review, we describe the different types of intraoperative CDS systems with specific emphasis on real-time systems. The technical considerations in developing and implementing real-time CDS are systematically covered. This includes the functional modules of a CDS system, development and execution of decision rules, and modalities to alert anesthesia providers concerning clinical issues. We also describe the regulatory aspects that affect development, implementation, and use of intraoperative CDS. Methods and measures to assess the effectiveness of intraoperative CDS are discussed. Last, we outline areas of future development of intraoperative CDS, particularly the possibility of providing predictive and prescriptive decision support.

Green synthesis of multifunctional carbon dots from coriander leaves and their potential application as antioxidants, sensors and bioimaging agents.

PubMed

Sachdev, Abhay; Gopinath, P

2015-06-21

In the present study, a facile one-step hydrothermal treatment of coriander leaves for preparing carbon dots (CDs) has been reported. Optical and structural properties of the CDs have been extensively studied by UV-visible and fluorescence spectroscopic, microscopic (transmission electron microscopy, scanning electron microscopy) and X-ray diffraction techniques. Surface functionality and composition of the CDs have been illustrated by elemental analysis and Fourier transform infrared spectroscopy (FTIR). Quenching of the fluorescence of the CDs in the presence of metal ions is of prime significance, hence CDs have been used as a fluorescence probe for sensitive and selective detection of Fe(3+) ions. Eventually, biocompatibility and bioimaging aspects of CDs have been evaluated on lung normal (L-132) and cancer (A549) cell lines. Qualitative analysis of cellular uptake of CDs has been pursued through fluorescence microscopy, while quantitative analysis using a flow cytometer provided an insight into the concentration and cell-type dependent uptake of CDs. The article further investigates the antioxidant activity of CDs. Therefore, we have validated the practicality of CDs obtained from a herbal carbon source for versatile applications.

Preparation of highly luminescent and biocompatible carbon dots using a new extraction method

NASA Astrophysics Data System (ADS)

Zhang, Rui; Liu, Ying-Bo; Sun, Shu-Qing

2013-10-01

C dots (CDs) are among the most promising emerging fluorescent labels for biological imaging and sensing. A facile new synthesis method was developed using common organic solvents for fabricating CDs from candle soot. The common organic solvents were used as extractants and the obtained CDs have a narrow size distribution with average diameters of about 3.4 nm for ethylene glycol, 3.5 nm for ethanol, and 3.4 nm for n-butanol. This approach is simpler, easier, and more effective than other methods currently used for CD fabrication. The obtained CDs had a high quantum yield (38 %), tunable emission and are water-soluble. The mechanism for the luminescence of the CDs was investigated and the results indicate that the ability of the solvent to disperse the CDs plays a very important role in the photoluminescence of these CDs. The type of organic solvent and the surface groups on the CDs also influenced the optical properties of the CDs. Different emissive traps are shown to play the major role in the luminescence of the carbon materials. An in vitro hemolysis assay was performed and showed that the CDs are biocompatible.

Preoperative planning of calcium deposit removal in calcifying tendinitis of the rotator cuff - possible contribution of computed tomography, ultrasound and conventional X-Ray.

PubMed

Izadpanah, Kaywan; Jaeger, Martin; Maier, Dirk; Südkamp, Norbert P; Ogon, Peter

2014-11-20

The purpose of the present study was to investigate the accuracy of Ultrasound (US), conventional X-Ray (CX) and Computed Tomography (CT) to estimate the total count, localization, morphology and consistency of Calcium deposits (CDs) in the rotator cuff. US, CX and CT imaging was performed pre-operatively in 151 patients who underwent arthroscopic removal of CDs in the rotator cuff. In all procedures: (1) total CD counts were determined, (2) the CDs appearance in each image modality was correlated to the intraoperative consistency and (3) CDs were localized in their relation to the acromion using US, CX and CT. Using US158 CDs, using CT 188 CDs and using CX 164 CDs were identified. Reliable localization of the CDs was possible with all used diagnostic modalities. CT revealed 49% of the CDs to be septated, out of which 85% were uni- and 15% multiseptated. CX was not suitable for prediction of CDs consistency. US reliably predicted viscous-solid CDs consistency only when presenting with full sound extinction (PPV 84.6%) . CT had high positive and negative predictive values for detection of liquid-soft (PPV 92.9%) and viscous-solid (PPV 87.8%) CDs. US and CX are sufficient for preoperative planning of CD removal with regards to localization and prediction of consistency if the deposits present with full sound extinction. This is the case in the majority of the patients. However, in patients with missing sound extinction CT can be recommended if CDs consistency of the deposits should be determined. Satellite deposits or septations are regularly present, which is of importance if complete CD removal is aspired.

Highly fluorescent Zn-doped carbon dots as Fenton reaction-based bio-sensors: an integrative experimental-theoretical consideration.

PubMed

Xu, Quan; Liu, Yao; Su, Rigu; Cai, Lulu; Li, Bofan; Zhang, Yingyuan; Zhang, Linzhou; Wang, Yajun; Wang, Yan; Li, Neng; Gong, Xiao; Gu, Zhipeng; Chen, Yusheng; Tan, Yanglan; Dong, Chenbo; Sreeprasad, Theruvakkattil Sreenivasan

2016-10-20

Heteroatom doped carbon dots (CDs), with high photoluminescence quantum yield (PLQY), are of keen interest in various applications such as chemical sensors, bio-imaging, electronics, and photovoltaics. Zinc, an important element assisting the electron-transfer process and an essential trace element for cells, is a promising metal dopant for CDs, which could potentially lead to multifunctional CDs. In this contribution, we report a single-step, high efficiency, hydrothermal method to synthesize Zn-doped carbon dots (Zn-CDs) with a superior PLQY. The PLQY and luminescence characteristic of Zn-CDs can be tuned by controlling the precursor ratio, and the surface oxidation in the CDs. Though a few studies have reported metal doped CDs with good PLQY, the as prepared Zn-Cds in the present method exhibited a PLQY up to 32.3%. To the best of our knowledge, there is no report regarding the facile preparation of single metal-doped CDs with a QY more than 30%. Another unique attribute of the Zn-CDs is the high monodispersity and the resultant highly robust excitation-independent luminescence that is stable over a broad range of pH values. Spectroscopic investigations indicated that the superior PLQY and luminescence of Zn-CDs are due to the heteroatom directed, oxidized carbon-based surface passivation. Furthermore, we developed a novel and sensitive biosensor for the detection of hydrogen peroxide and glucose leveraging the robust fluorescence properties of Zn-CDs. Under optimal conditions, Zn-CDs demonstrated high sensitivity and response to hydrogen peroxide and glucose over a wide range of concentrations, with a linear range of 10-80 μM and 5-100 μM, respectively, indicating their great potential as a fluorescent probe for chemical sensing.

Influence of wide band gap oxide substrates on the photoelectrochemical properties and structural disorder of CdS nanoparticles grown by the successive ionic layer adsorption and reaction (SILAR) method

PubMed Central

Malashchonak, Mikalai V; Korolik, Olga V; Streltsov, Еugene А; Kulak, Anatoly I

2015-01-01

Summary The photoelectrochemical properties of nanoheterostructures based on the wide band gap oxide substrates (ZnO, TiO2, In2O3) and CdS nanoparticles deposited by the successive ionic layer adsorption and reaction (SILAR) method have been studied as a function of the CdS deposition cycle number (N). The incident photon-to-current conversion efficiency (IPCE) passes through a maximum with the increase of N, which is ascribed to the competition between the increase in optical absorption and photocarrier recombination. The maximal IPCE values for the In2O3/CdS and ZnO/CdS heterostructures are attained at N ≈ 20, whereas for TiO2/CdS, the appropriate N value is an order of magnitude higher. The photocurrent and Raman spectroscopy studies of CdS nanoparticles revealed the occurrence of the quantum confinement effect, demonstrating the most rapid weakening with the increase of N in ZnO/CdS heterostructures. The structural disorder of CdS nanoparticles was characterized by the Urbach energy (E U), spectral width of the CdS longitudinal optical (LO) phonon band and the relative intensity of the surface optical (SO) phonon band in the Raman spectra. Maximal values of E U (100–120 meV) correspond to СdS nanoparticles on a In2O3 surface, correlating with the fact that the CdS LO band spectral width and intensity ratio for the CdS SO and LO bands are maximal for In2O3/CdS films. A notable variation in the degree of disorder of CdS nanoparticles is observed only in the initial stages of CdS growth (several tens of deposition cycles), indicating the preservation of the nanocrystalline state of CdS over a wide range of SILAR cycles. PMID:26734517

Influence of wide band gap oxide substrates on the photoelectrochemical properties and structural disorder of CdS nanoparticles grown by the successive ionic layer adsorption and reaction (SILAR) method.

PubMed

Malashchonak, Mikalai V; Mazanik, Alexander V; Korolik, Olga V; Streltsov, Еugene А; Kulak, Anatoly I

2015-01-01

The photoelectrochemical properties of nanoheterostructures based on the wide band gap oxide substrates (ZnO, TiO2, In2O3) and CdS nanoparticles deposited by the successive ionic layer adsorption and reaction (SILAR) method have been studied as a function of the CdS deposition cycle number (N). The incident photon-to-current conversion efficiency (IPCE) passes through a maximum with the increase of N, which is ascribed to the competition between the increase in optical absorption and photocarrier recombination. The maximal IPCE values for the In2O3/CdS and ZnO/CdS heterostructures are attained at N ≈ 20, whereas for TiO2/CdS, the appropriate N value is an order of magnitude higher. The photocurrent and Raman spectroscopy studies of CdS nanoparticles revealed the occurrence of the quantum confinement effect, demonstrating the most rapid weakening with the increase of N in ZnO/CdS heterostructures. The structural disorder of CdS nanoparticles was characterized by the Urbach energy (E U), spectral width of the CdS longitudinal optical (LO) phonon band and the relative intensity of the surface optical (SO) phonon band in the Raman spectra. Maximal values of E U (100-120 meV) correspond to СdS nanoparticles on a In2O3 surface, correlating with the fact that the CdS LO band spectral width and intensity ratio for the CdS SO and LO bands are maximal for In2O3/CdS films. A notable variation in the degree of disorder of CdS nanoparticles is observed only in the initial stages of CdS growth (several tens of deposition cycles), indicating the preservation of the nanocrystalline state of CdS over a wide range of SILAR cycles.

TiO2 activity enhancement through synergistic effect of photons localization of photonic crystals and the sensitization of CdS quantum dots

NASA Astrophysics Data System (ADS)

Li, Ping; Wang, Yuan; Wang, Ai-Jun; Chen, Sheng-Li

2017-02-01

In this work, the enhancement of TiO2 photocatalytic activity was studied through synergistic effect of the photons localization of photonic crystals and the sensitization of CdS quantum dots (CdS QDs). CdS QDs sensitized TiO2 membrane (denoted as CdS QDs/TiO2) was synthesized through doping the TiO2 membrane with CdS QDs by chemical bath deposition method (CBD). After TiO2 was sensitized with CdS QDs, the edge of light absorption of TiO2 was red-shifted to 470 nm and the light absorption in the range of 400 600 nm was higher than that of plain TiO2 membrane. Another type of composite membrane, CdS QDs/TiO2/SiO2 opal composite membrane was prepared by coupling SiO2 opal (a kind of photonic crystal) layer onto the CdS QDs/TiO2 membrane, and the photonic band gap of the SiO2 opal photonic crystal layer was deliberately planned at the electronic band gap of the CdS QDs. The photodegradation of gaseous CH3CHO (acetaldehyde) was used as probe reaction to test the photocatalytic activity of the as-prepared membranes, and the results showed that the CdS QDs sensitization can significantly improve the photocatalytic activity of TiO2 membrane under visible light irradiation, with the acetaldehyde degradation rate constant (k) on CdS QDs/TiO2 membranes being 1.59 times of that on plain TiO2 membranes. The acetaldehyde degradation rate constant on CdS QDs/TiO2/SiO2 opal composite membrane reached 4 times of that on plain TiO2 membrane. The photocatalytic activity of TiO2 membrane can be improved through synergistic effect of the photons localization of photonic crystals and the sensitization of CdS QDs.

Structural and optoelectronic studies on Ag-CdS quantum dots

NASA Astrophysics Data System (ADS)

Ibrahim Mohammed S., M.; Gubari, Ghamdan M. M.; Huse, Nanasaheb P.; Dive, Avinash S.; Sharma, Ramphal

2018-05-01

In the present study, we have successfully deposited CdS quantum dot thin films and Ag doped CdS on a glass slide by simple and economical chemical bath deposition at room temperature. The X-ray diffraction method analysis reveals that CdS thin films exhibit hexagonal structure when compared with standard JCPDS data. The estimated average crystallite size of the quantum dots and resulted in the least crystallite size of ˜9 nm. a comparison between the optical and electrical properties of the films before and after doping Ag was made through measuring and analyzing the curves for UV and I-V. From UV absorption spectra we observed that the samples exhibited a band edge near ˜400 nm with a slight deviation with the presence of excitonic peak for both CdS and Ag doped CdS. The presence of excitonic peak may be referred to the formation of quantum dots. The calculated band gap energy of thin films was found to be 3.45 eV and 3.15 eV for both CdS and Ag doped CdS thin films respectively, where the optical absorption spectra of Ag doped CdS nanoparticles also exhibit shift with respect to that of CdS quantum dots thin films. The photosensitive of CdS thin films show an increase in photocurrent when Ag doped CdS.

Hexagonal pencil-like CdS nanorods: Facile synthesis and enhanced visible light photocatalytic performance

NASA Astrophysics Data System (ADS)

An, Liang; Wang, Guanghui; Zhao, Lei; Zhou, Yong; Gao, Fang; Cheng, Yang

2015-07-01

In the present study, hexagonal pencil-like CdS nanorods have been successfully synthesized through a typical facile and economical one-step hydrothermal method without using any surfactant or template. The product was characterized by X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and energy dispersive analysis of X-ray (EDX). The results revealed that the prepared CdS photocatalyst consisted of a large quantity of straight and smooth solid hexagonal nanorods and a few nanoparticles. The photocatalytic activities of CdS nanorods and commercial CdS powders were investigated by the photodegradation of Orange II (OII) in aqueous solution under visible light, and the CdS nanorods presented the highest photocatalytic activity. Its photocatalytic efficiency enhancement was attributed to the improved transmission of photogenerated electron-hole pairs in the CdS nanostructures. The present findings may provide a facile approach to synthesize high efficient CdS photocatalysts.

La Freccia Rossa: an IR-dark cloud hosting the Milky Way intermediate-mass black hole candidate

NASA Astrophysics Data System (ADS)

Ravi, Vikram; Vedantham, Harish; Phinney, E. Sterl

2018-07-01

The dynamics of the high-velocity compact molecular cloud CO-0.40-0.22 have been interpreted as evidence for a ˜105 M⊙ black hole within 60 pc of Sgr A*. Recently, Oka et al. have identified a compact millimetre-continuum source, CO-0.40-0.22*, with this candidate black hole. Here we present a collation of radio and infrared data at this location. Australia Telescope Compact Array constraints on the radio spectrum, and the detection of a mid-infrared counterpart, are in tension with an Sgr A*-like model for CO-0.40-0.22* despite the comparable bolometric to the Eddington luminosity ratios under the intermediate-mass black hole interpretation. A protostellar-disc scenario is, however, tenable. CO-0.40-0.22(*) is positionally coincident with an arrowhead-shaped infrared-dark cloud (which we call the Freccia Rossa). If the VLSR ≈ 70 km s-1 systemic velocity of CO-0.40-0.22 is common to the entire Freccia Rossa system, we hypothesize that it is the remnant of a high-velocity cloud that has plunged into the Milky Way from the Galactic halo.

Laser Card For Compact Optical Data Storage Systems

NASA Astrophysics Data System (ADS)

Drexler, Jerome

1982-05-01

The principal thrust of the optical data storage industry to date has been the 10 billion bit optical disc system. Mass memory has been the primary objective. Another objective that is beginning to demand recognition is compact memory of 1 million to 40 million bits--on a wallet-size, laser recordable card. Drexler Technology has addressed this opportunity and has succeeded in demonstrating laser writing and readback using a 16 mm by 85 mm recording stripe mounted on a card. The write/read apparatus was developed by SRI International. With this unit, 5 micron holes have been recorded using a 10 milliwatt, 830 nanometer semiconductor-diode laser. Data is entered on an Apple II keyboard using the ASCII code. The recorded reflective surface is scanned with the same laser at lower power to generate a reflected bit stream which is converted into alphanumerics and which appear on the monitor. We are pleased to report that the combination of the DREXONTM laser recordable card ("Laser Card"), the semiconductor-diode laser, arrays of large recorded holes, and human interactive data rates are all mutually compatible and point the way forward to economically feasible, compact, data-storage systems.

Extracellular matrix components and culture regimen selectively regulate cartilage formation by self-assembling human mesenchymal stem cells in vitro and in vivo.

PubMed

Ng, Johnathan; Wei, Yiyong; Zhou, Bin; Burapachaisri, Aonnicha; Guo, Edward; Vunjak-Novakovic, Gordana

2016-12-09

Cartilage formation from self-assembling mesenchymal stem cells (MSCs) in vitro recapitulate important cellular events during mesenchymal condensation that precedes native cartilage development. The goal of this study was to investigate the effects of cartilaginous extracellular matrix (ECM) components and culture regimen on cartilage formation by self-assembling human MSCs in vitro and in vivo. Human bone marrow-derived MSCs (hMSCs) were seeded and compacted in 6.5-mm-diameter transwell inserts with coated (type I, type II collagen) or uncoated (vehicle) membranes, at different densities (0.5 × 10 6 , 1.0 × 10 6 , 1.5 × 10 6 per insert). Pellets were formed by aggregating hMSCs (0.25 × 10 6 ) in round-bottomed wells. All tissues were cultured for up to 6 weeks for in vitro analyses. Discs (cultured for 6, 8 or 10 weeks) and pellets (cultured for 10 weeks) were implanted subcutaneously in immunocompromised mice to evaluate the cartilage stability in vivo. Type I and type II collagen coatings enabled cartilage disc formation from self-assembling hMSCs. Without ECM coating, hMSCs formed dome-shaped tissues resembling the pellets. Type I collagen, expressed in the prechondrogenic mesenchyme, improved early chondrogenesis versus type II collagen. High seeding density improved cartilage tissue properties but resulted in a lower yield of disc formation. Discs and pellets exhibited compositional and organizational differences in vitro and in vivo. Prolonged chondrogenic induction of the discs in vitro expedited endochondral ossification in vivo. The outcomes of cartilage tissues formed from self-assembling MSCs in vitro and in vivo can be modulated by the control of culture parameters. These insights could motivate new directions for engineering cartilage and bone via a cartilage template from self-assembling MSCs.

Creative Practice : Design and Manufacturing of ‘CD Crusher’

NASA Astrophysics Data System (ADS)

Yamamoto, Koji; Senda, Shinkoh; Fukumori, Tsutom; Sato, Kazuo

A practice program for graduate students in mechanical engineering has been developed. The task of this training is to design and manufacture an original ‘CD crusher’ , a machine to mechanically destroy compact disks after use. This is a competition among groups of students creating their original CD crusher which fulfills the regulation. The regulation is that the crusher has to use rotational blades cutting the CDs. Same sized blades are supplied to the students groups. They are fabricated from a steel bar through cutting, annealing and quenching processes by the presence of students. Technical staffs are ready to help students on the whole way of the practice. However, they encourage initiative by the students from planning to manufacturing. Students satisfied at the practice according to the comments after competition.

Ultrasound-assisted microwave preparation of Ag-doped CdS nanoparticles.

PubMed

Ma, Jun; Tai, Guo'an; Guo, Wanlin

2010-03-01

Ag-doped CdS nanoparticles were synthesized by an ultrasound-assisted microwave synthesis method. The X-ray diffraction patterns reveal a structural evolution from cubic to hexagonal with increasing molar ratios of Ag(+)/Cd(2+) from 0% to 5%. It shows that the Ag-doped hexagonal CdS nanoparticles are polycrystal. The X-ray photoelectron spectroscopy of the CdS nanoparticles doping with 5% Ag(+) shows that the doped Ag in CdS is metallic. Simultaneously, the characteristic Raman peaks of the CdS nanoparticles enhance with increasing Ag(+) concentrations. The photocatalytic activity of different Ag-doped samples show a reasonable change due to different ratios of Ag which doped into CdS. Copyright 2009 Elsevier B.V. All rights reserved.

The Gaia-ESO Survey: the present-day radial metallicity distribution of the Galactic disc probed by pre-main-sequence clusters

NASA Astrophysics Data System (ADS)

Spina, L.; Randich, S.; Magrini, L.; Jeffries, R. D.; Friel, E. D.; Sacco, G. G.; Pancino, E.; Bonito, R.; Bravi, L.; Franciosini, E.; Klutsch, A.; Montes, D.; Gilmore, G.; Vallenari, A.; Bensby, T.; Bragaglia, A.; Flaccomio, E.; Koposov, S. E.; Korn, A. J.; Lanzafame, A. C.; Smiljanic, R.; Bayo, A.; Carraro, G.; Casey, A. R.; Costado, M. T.; Damiani, F.; Donati, P.; Frasca, A.; Hourihane, A.; Jofré, P.; Lewis, J.; Lind, K.; Monaco, L.; Morbidelli, L.; Prisinzano, L.; Sousa, S. G.; Worley, C. C.; Zaggia, S.

2017-05-01

Context. The radial metallicity distribution in the Galactic thin disc represents a crucial constraint for modelling disc formation and evolution. Open star clusters allow us to derive both the radial metallicity distribution and its evolution over time. Aims: In this paper we perform the first investigation of the present-day radial metallicity distribution based on [Fe/H] determinations in late type members of pre-main-sequence clusters. Because of their youth, these clusters are therefore essential for tracing the current interstellar medium metallicity. Methods: We used the products of the Gaia-ESO Survey analysis of 12 young regions (age < 100 Myr), covering Galactocentric distances from 6.67 to 8.70 kpc. For the first time, we derived the metal content of star forming regions farther than 500 pc from the Sun. Median metallicities were determined through samples of reliable cluster members. For ten clusters the membership analysis is discussed in the present paper, while for other two clusters (I.e. Chamaeleon I and Gamma Velorum) we adopted the members identified in our previous works. Results: All the pre-main-sequence clusters considered in this paper have close-to-solar or slightly sub-solar metallicities. The radial metallicity distribution traced by these clusters is almost flat, with the innermost star forming regions having [Fe/H] values that are 0.10-0.15 dex lower than the majority of the older clusters located at similar Galactocentric radii. Conclusions: This homogeneous study of the present-day radial metallicity distribution in the Galactic thin disc favours models that predict a flattening of the radial gradient over time. On the other hand, the decrease of the average [Fe/H] at young ages is not easily explained by the models. Our results reveal a complex interplay of several processes (e.g. star formation activity, initial mass function, supernova yields, gas flows) that controlled the recent evolution of the Milky Way. Based on observations made with the ESO/VLT, at Paranal Observatory, under program 188.B-3002 (The Gaia-ESO Public Spectroscopic Survey).Full Table 1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/601/A70

Nitrogen and sulfur co-doped carbon dots with strong blue luminescence.

PubMed

Ding, Hui; Wei, Ji-Shi; Xiong, Huan-Ming

2014-11-21

Sulfur-doped carbon dots (S-CDs) with a quantum yield (QY) of 5.5% and nitrogen, sulfur co-doped carbon dots (N,S-CDs) with a QY of 54.4% were synthesized, respectively, via the same hydrothermal route using α-lipoic acid as the carbon source. The obtained S-CDs and N,S-CDs had similar sizes but different optical features. The QY of N,S-CDs was gradually enhanced when extending the reaction time to increase the nitrogen content. After careful characterization of these CDs, the doped nitrogen element was believed to be in the form of C=N and C-N bonds which enhanced the fluorescence efficiency significantly. Meanwhile, the co-doped sulfur element was found to be synergistic for nitrogen doping in N,S-CDs. The optimal N,S-CDs were successfully employed as good multicolor cell imaging probes due to their fine dispersion in water, excitation-dependent emission, excellent fluorescence stability and low toxicity. Besides, such N,S-CDs showed a wide detection range and excellent accuracy as fluorescent sensors for Fe(3+) ions.

Chemical Synthesis and Optical Properties of CdS Poly(Lactic Acid) Nanocomposites and Their Transparent Fluorescent Films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Cai-Feng; Cheng, Yu-Peng; Xie, He-Yi

2011-01-01

This paper describes the chemical synthesis of cadmium sulfide (CdS) polymer nanocomposites by covalently grafting poly(lactic acid) (PLA) onto the surfaces of CdS nanocrystals (NCs). Synthesis of the nanocomposites involved two steps. Lactic acid (LA) capped CdS NCs were first prepared by reacting cadmium chloride (CdCl2) with sodium sulfide (Na2S) using LA as the organic ligand in H2O/N,N-dimethylformamide (DMF) solution. Next CdS PLA nanocomposites were formed by in situ ring-opening polymerization of lactide on the surface of modified CdS NCs. Transparent fluorescent films were then successfully prepared by blending as-prepared CdS PLA nanocomposites with high-molecular-weight PLA. The as-prepared CdS NCsmore » and their nanocomposites were studied by transmission electron microscopic imaging, thermogravimetric analyses, and spectroscopic measurements (ultraviolet-visible absorption and photoluminescence). The spectroscopic studies revealed that the CdS polymer nanocomposites exhibited good optical properties in terms of their photoluminescence and transparency.« less

Magellan Final Science Reports

NASA Technical Reports Server (NTRS)

Thompson, Thomas W.

1993-01-01

This volume is a brief summary of the scientific results of the Magellan Venus mapping mission as reported by the Magellan science investigators. Magellan has exceeded all of its mission objectives by obtaining high resolution radar images, surface elevation, and radiometry for more than 98% of the planet. The amount of stereo data gathered on Venus is more than that available for any other planet. Magellan's fourth cycle collected gravity data from an elliptical orbit to provide information on the relationships between surface features and the interior of the planet. With the successful completion of the aerobraking experiment, the spacecraft, in its lower orbit around Venus, has captured high resolution gravity near the poles from the nearly circular orbit. Every attempt has been made to provide useful documentation for the complete Magellan data set. Magellan data have been released to the public through the Planetary Data System (PDS) and the National Space Science Data Center (NSSDC) in photographs, lithos, brochures, digital form, and compact discs. With the release of Magellan data on the compact disc read-only-memory (CD-ROM) a revolutionary new way of doing science has resulted. This technology provides a way to store, distribute and access large volumes of data. The Magellan science investigators have utilized this wealth of data to provide answers to questions we have been asking for a long time. I would like to personally thank everyone on the Magellan team for the success of this important mission, a mission that has revealed information that will help us to better understand our own Planet Earth.

Watershed boundaries and digital elevation model of Oklahoma derived from 1:100,000-scale digital topographic maps

USGS Publications Warehouse

Cederstrand, J.R.; Rea, A.H.

1995-01-01

This document provides a general description of the procedures used to develop the data sets included on this compact disc. This compact disc contains watershed boundaries for Oklahoma, a digital elevation model, and other data sets derived from the digital elevation model. The digital elevation model was produced using the ANUDEM software package, written by Michael Hutchinson and licensed from the Centre for Resource and Environmental Studies at The Australian National University. Elevation data (hypsography) and streams (hydrography) from digital versions of the U.S. Geological Survey 1:100,000-scale topographic maps were used by the ANUDEM package to produce a hydrologically conditioned digital elevation model with a 60-meter cell size. This digital elevation model is well suited for drainage-basin delineation using automated techniques. Additional data sets include flow-direction, flow-accumulation, and shaded-relief grids, all derived from the digital elevation model, and the hydrography data set used in producing the digital elevation model. The watershed boundaries derived from the digital elevation model have been edited to be consistent with contours and streams from the U.S. Geological Survey 1:100,000-scale topographic maps. The watershed data set includes boundaries for 11-digit Hydrologic Unit Codes (watersheds) within Oklahoma, and 8-digit Hydrologic Unit Codes (cataloging units) outside Oklahoma. Cataloging-unit boundaries based on 1:250,000-scale maps outside Oklahoma for the Arkansas, Red, and White River basins are included. The other data sets cover Oklahoma, and where available, portions of 1:100,000-scale quadrangles adjoining Oklahoma.

Utilization of Condensed Distillers Solubles as Nutrient Supplement for Production of Nisin and Lactic Acid from Whey

NASA Astrophysics Data System (ADS)

Liu, Chuanbin; Hu, Bo; Chen, Shulin; Glass, Richard W.

The major challenge associated with the rapid growth of the ethanol industry is the usage of the coproducts, i.e., condensed distillers solubles (CDS) and distillers dried grains, which are currently sold as animal feed supplements. As the growth of the livestock industries remains flat, alternative usage of these coproducts is urgently needed. CDS is obtained after the removal of ethanol by distillation from the yeast fermentation of a grain or a grain mixture by condensing the thin stillage fraction to semisolid. In this work, CDS was first characterized and yeast biomass was proven to be the major component of CDS. CDS contained 7.50% crude protein but with only 42% of that protein being water soluble. Then, CDS was applied as a nutrient supplement for simultaneous production of nisin and lactic acid by Lactococcus lactis subsp. lactis (ATCC 11454). Although CDS was able to support bacteria growth and nisin production, a strong inhibition was observed when CDS was overdosed. This may be caused by the existence of the major ethanol fermentation byproducts, especially lactate and acetate, in CDS. In the final step, the CDS based medium composition for nisin and lactic acid production was optimized using response surface methodology.

Preparation and characterization of photocatalytic carbon dots-sensitized electrospun titania nanostructured fibers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Haopeng; Zhu, Yihua, E-mail: yhzhu@ecust.edu.cn; Cao, Huimin

2013-02-15

Graphical abstract: Display Omitted Highlights: ► The TiO{sub 2}-CDs nanostructured fibers are fabricated by using APS combining the electrospinning TiO{sub 2} nanostructured fibers and CDs. ► The CD can work as a photosensitizer in the degradation of rhodamine B under visible light irradiation. ► The TiO{sub 2}-CDs nanostructured fibers exhibit enhanced photocatalytic efficiency and can be easily handled and recycled. -- Abstract: The carbon dots (CDs) are new functional carbon-aceous materials. Compared to conventional dye molecules and semiconductor quantum dots, CDs are superior in chemical inertness and low toxicity. The TiO{sub 2}-CDs nanostructured fibers were fabricated by combining the electrospinningmore » technique and reflux method. Compared with the pure TiO{sub 2} nanostructured fibers and P25, the TiO{sub 2}-CDs nanostructured fibers exhibited enhanced photocatalytic efficiency of photodegradation of rhodamine B (RhB) under visible light irradiation. The enhanced photocatalytic activity of TiO{sub 2}-CDs nanostructured fibers could be attributed to the presence of CDs embedded in TiO{sub 2} nanostructured fibers. The CD can work as a photosensitizer in the degradation. Furthermore, the TiO{sub 2}-CDs nanostructured fibers could be easily handled and recycled due to their one-dimensional nanostructural property.« less

Green synthesis of carbon dots originated from Lycii Fructus for effective fluorescent sensing of ferric ion and multicolor cell imaging.

PubMed

Sun, Xiaohan; He, Jiang; Yang, Shenghong; Zheng, Mingda; Wang, Yingying; Ma, Shuang; Zheng, Haipeng

2017-10-01

Green, economical and effective method was developed for synthesis of fluorescent carbon dots (CDs), using one-pot hydrothermal treatment of Lycii Fructus. Optical and structural properties of the CDs have been extensively studied by UV-visible and fluorescence spectroscopic, x-ray diffraction (XRD) techniques, transmission electron microscopy (TEM) and high resolution TEM (HRTEM). Surface functionality and composition of CDs has been illustrated by Fourier transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS) spectra and elemental analysis. The fabricated CDs possess stable fluorescent properties. The fluorescent quantum yield of the CDs can reach 17.2%. The prepared CDs emitted a broad fluorescence between 415 and 545nm and their fluorescence was tuned by changing excitation wavelength. Meanwhile, the fluorescence intensity of the CDs could be significantly quenched by Fe 3+ (turn-off). The CDs exhibit captivating sensitivity and selectivity toward Fe 3+ with a linear range from 0 to 30μM and a detection limit of 21nM. The prepared CDs were successfully applied to the determination of Fe 3+ in the urine samples, the water samples from the from the Yellow River and living HeLa (Henrietta Lacks) cells. Moreover, the low-toxicity and excellent biocompatibility of the CDs were evaluated through MTT assay on HeLa cells. The CDs were also employed as fluorescent probes for multicolor imaging of HeLa cells successfully. Copyright © 2017 Elsevier B.V. All rights reserved.

CIC-DUX4 Induces Small Round Cell Sarcomas Distinct from Ewing Sarcoma.

PubMed

Yoshimoto, Toyoki; Tanaka, Miwa; Homme, Mizuki; Yamazaki, Yukari; Takazawa, Yutaka; Antonescu, Cristina R; Nakamura, Takuro

2017-06-01

CIC-DUX4 sarcoma (CDS) or CIC-rearranged sarcoma is a subcategory of small round cell sarcoma resembling the morphological phenotypes of Ewing sarcoma (ES). However, recent clinicopathologic and molecular genetic analyses indicate that CDS is an independent disease entity from ES. Few ancillary markers have been used in the differential diagnosis of CDS, and additional CDS-specific biomarkers are needed for more definitive classification. Here, we report the generation of an ex vivo mouse model for CDS by transducing embryonic mesenchymal cells (eMC) with human CIC-DUX4 cDNA. Recipient mice transplanted with eMC-expressing CIC-DUX4 rapidly developed an aggressive, undifferentiated sarcoma composed of small round to short spindle cells. Gene-expression profiles of CDS and eMC revealed upregulation of CIC-DUX4 downstream genes such as PEA3 family genes, Ccnd2, Crh , and Zic1 IHC analyses for both mouse and human tumors showed that CCND2 and MUC5AC are reliable biomarkers to distinguish CDS from ES. Gene silencing of CIC-DUX4 as well as Ccnd2, Ret , and Bcl2 effectively inhibited CDS tumor growth in vitro The CDK4/6 inhibitor palbociclib and the soft tissue sarcoma drug trabectedin also blocked the growth of mouse CDS. In summary, our mouse model provides important biological information about CDS and provides a useful platform to explore biomarkers and therapeutic agents for CDS. Cancer Res; 77(11); 2927-37. ©2017 AACR . ©2017 American Association for Cancer Research.

Optical Properties of CdS Nanobelts and Nanosaws Synthesized by Thermal Evaporation Method

NASA Astrophysics Data System (ADS)

Peng, Zhi-wei; Zou, Bing-suo

2012-04-01

By a simple one-step H2-assisted thermal evaporation method, high quality CdS nanostructures have been successfully fabricated on Au coated Si substrates in large scale. The as-synthesized CdS nanostructures consisted of sword-like nanobelts and toothed nanosaws with a single-crystal hexagonal wurtzite structure. The deposition temperature played an important role in determining the size and morphology of the CdS nanostructures. A combination of vapor-liquid-solid and vapor-solid growth mechanisms were proposed to interpret the formation of CdS nanostructures. Photoluminescence measurement indicated that the nanobelts and nanosaws have a prominent green emission at about 512 nm, which is the band-to-band emission of CdS. The waveguide characteristics of both types of CdS nanostructures were observed and discussed.

Outcomes of clinical decision support (CDS) and correlates of CDS use for home care patients with high medication regimen complexity: A randomized trial

PubMed Central

McDonald, Margaret V.; Feldman, Penny H.; Barrón-Vayá, Yolanda; Peng, Timothy R.; Sridharan, Sridevi; Pezzin, Liliana E.

2017-01-01

Objective To assess the outcomes of a clinical decision support (CDS) intervention designed for home care patients with high medication regimen complexity (MRC) and to examine the correlates of CDS use and its relationship to patient outcomes. Method The intervention randomized nurses upon identification of an eligible patient. The CDS consisted of a computerized algorithm that identified high MRC patients, electronic clinician alerts, and a care management module. Analyses were completed on full intention to treat and intervention group-only samples. Regression-adjusted outcomes were hospitalization, emergency department use and reduction in MRC. Data sources included health records and administrative data. Results Five hundred nurses were randomized with 7,919 of their patients. Approximately 20% of the intervention group was hospitalized versus 21% in the control group; 16.5% of the intervention group had an emergency department visit versus 16.7% in the control group; and 6% in each group dropped below the high MRC threshold. No statistically significant differences were found in the intention to treat analysis. Eighty-two percent of intervention nurses used the CDS but for only 42% of their patients. Among intervention patients, CDS use (versus non-use) was associated with reduced MRC and hospitalization. CDS use was more likely among older nurses, those with higher study-patient caseload and, marginally, among salaried nurses and those with longer tenure. Significant patient characteristics were clinical conditions, payer, episode length, care continuity and race. Conclusion CDS use was limited, thus negating the impact of the intervention overall. The findings on correlates of CDS use and the relationship between CDS use and positive outcomes suggest that CDS use and outcomes could be enhanced by avoiding very short patient lengths of stay, improving continuity of care, increasing reliance on salaried nurses and/or increasing per diem nurses’ incentives to use CDS. PMID:26009977

The very faint X-ray binary IGR J17062-6143: a truncated disc, no pulsations, and a possible outflow

NASA Astrophysics Data System (ADS)

van den Eijnden, J.; Degenaar, N.; Pinto, C.; Patruno, A.; Wette, K.; Messenger, C.; Hernández Santisteban, J. V.; Wijnands, R.; Miller, J. M.; Altamirano, D.; Paerels, F.; Chakrabarty, D.; Fabian, A. C.

2018-04-01

We present a comprehensive X-ray study of the neutron star low-mass X-ray binary IGR J17062-6143, which has been accreting at low luminosities since its discovery in 2006. Analysing NuSTAR, XMM-Newton, and Swift observations, we investigate the very faint nature of this source through three approaches: modelling the relativistic reflection spectrum to constrain the accretion geometry, performing high-resolution X-ray spectroscopy to search for an outflow, and searching for the recently reported millisecond X-ray pulsations. We find a strongly truncated accretion disc at 77^{+22}_{-18} gravitational radii (˜164 km) assuming a high inclination, although a low inclination and a disc extending to the neutron star cannot be excluded. The high-resolution spectroscopy reveals evidence for oxygen-rich circumbinary material, possibly resulting from a blueshifted, collisionally ionized outflow. Finally, we do not detect any pulsations. We discuss these results in the broader context of possible explanations for the persistent faint nature of weakly accreting neutron stars. The results are consistent with both an ultra-compact binary orbit and a magnetically truncated accretion flow, although both cannot be unambiguously inferred. We also discuss the nature of the donor star and conclude that it is likely a CO or O-Ne-Mg white dwarf, consistent with recent multiwavelength modelling.

A Multi-Anatomical Retinal Structure Segmentation System for Automatic Eye Screening Using Morphological Adaptive Fuzzy Thresholding

PubMed Central

Elleithy, Khaled; Elleithy, Abdelrahman

2018-01-01

Eye exam can be as efficacious as physical one in determining health concerns. Retina screening can be the very first clue for detecting a variety of hidden health issues including pre-diabetes and diabetes. Through the process of clinical diagnosis and prognosis; ophthalmologists rely heavily on the binary segmented version of retina fundus image; where the accuracy of segmented vessels, optic disc, and abnormal lesions extremely affects the diagnosis accuracy which in turn affect the subsequent clinical treatment steps. This paper proposes an automated retinal fundus image segmentation system composed of three segmentation subsystems follow same core segmentation algorithm. Despite of broad difference in features and characteristics; retinal vessels, optic disc, and exudate lesions are extracted by each subsystem without the need for texture analysis or synthesis. For sake of compact diagnosis and complete clinical insight, our proposed system can detect these anatomical structures in one session with high accuracy even in pathological retina images. The proposed system uses a robust hybrid segmentation algorithm combines adaptive fuzzy thresholding and mathematical morphology. The proposed system is validated using four benchmark datasets: DRIVE and STARE (vessels), DRISHTI-GS (optic disc), and DIARETDB1 (exudates lesions). Competitive segmentation performance is achieved, outperforming a variety of up-to-date systems and demonstrating the capacity to deal with other heterogeneous anatomical structures. PMID:29888146

Structured representation for core elements of common clinical decision support interventions to facilitate knowledge sharing.

PubMed

Zhou, Li; Hongsermeier, Tonya; Boxwala, Aziz; Lewis, Janet; Kawamoto, Kensaku; Maviglia, Saverio; Gentile, Douglas; Teich, Jonathan M; Rocha, Roberto; Bell, Douglas; Middleton, Blackford

2013-01-01

At present, there are no widely accepted, standard approaches for representing computer-based clinical decision support (CDS) intervention types and their structural components. This study aimed to identify key requirements for the representation of five widely utilized CDS intervention types: alerts and reminders, order sets, infobuttons, documentation templates/forms, and relevant data presentation. An XML schema was proposed for representing these interventions and their core structural elements (e.g., general metadata, applicable clinical scenarios, CDS inputs, CDS outputs, and CDS logic) in a shareable manner. The schema was validated by building CDS artifacts for 22 different interventions, targeted toward guidelines and clinical conditions called for in the 2011 Meaningful Use criteria. Custom style sheets were developed to render the XML files in human-readable form. The CDS knowledge artifacts were shared via a public web portal. Our experience also identifies gaps in existing standards and informs future development of standards for CDS knowledge representation and sharing.

Biomolecule-assisted construction of cadmium sulfide hollow spheres with structure-dependent photocatalytic activity.

PubMed

Wei, Chengzhen; Zang, Wenzhe; Yin, Jingzhou; Lu, Qingyi; Chen, Qun; Liu, Rongmei; Gao, Feng

2013-02-25

In this study, we report the synthesis of monodispersive solid and hollow CdS spheres with structure-dependent photocatalytic abilities for dye photodegradation. The monodispersive CdS nanospheres were constructed with the assistance of the soulcarboxymthyi chitosan biopolymer under hydrothermal conditions. The solid CdS spheres were corroded by ammonia to form hollow CdS nanospheres through a dissolution-reprecipitation mechanism. Their visible-light photocatalytic activities were investigated, and the results show that both the solid and the hollow CdS spheres have visible-light photocatalytic abilities for the photodegradation of dyes. The photocatalytic properties of the CdS spheres were demonstrated to be structure dependent. Although the nanoparticles comprising the hollow spheres have larger sizes than those comprising the solid spheres, the hollow CdS spheres have better photocatalytic performances than the solid CdS spheres, which can be attributed to the special hollow structure. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Resonance Rayleigh scattering technique for simple and sensitive analysis of tannic acid with carbon dots

NASA Astrophysics Data System (ADS)

Shi, Ying; Yang, Liu; Zhu, Jinghui; Yang, Jidong; Liu, Shaopu; Qiao, Man; Duan, Ruilin; Hu, Xiaoli

2017-02-01

Carbon dots (CDs) are raising a substantial amount of attention owing to their many unique and novel physicochemical properties. Herein one-pot synthesized CDs, to the best of our knowledge, were first served as the robust nanoprobe for detection tannic acid (TA) based on resonance Rayleigh scattering technique. The as-prepared CDs can combine with TA via hydrogen bond, resulting in remarkable enhancement of scattering signal with no changes in the fluorescence of CDs. Therefore, a novel protocol for TA determination was established and this strategy allowed quantitative detection of TA in the linear range of 0.2-10.0 μmol L- 1 with an excellent detection limit of 9.0 nmol L- 1. Moreover, the CDs based nanoprobe can be applied to the determination of TA in water sample with satisfactory results. Our study can potentially influence our current views on CDs and particularly impressive and offers new insights into application of CDs beyond the traditional understanding of CDs.

Development of a Tailored Intervention With Computerized Clinical Decision Support to Improve Quality of Care for Patients With Knee Osteoarthritis: Multi-Method Study.

PubMed

Van de Velde, Stijn; Kortteisto, Tiina; Spitaels, David; Jamtvedt, Gro; Roshanov, Pavel; Kunnamo, Ilkka; Aertgeerts, Bert; Vandvik, Per Olav; Flottorp, Signe

2018-06-11

Clinical practice patterns greatly diverge from evidence-based recommendations to manage knee osteoarthritis conservatively before resorting to surgery. This study aimed to tailor a guideline-based computerized decision support (CDS) intervention that facilitates the conservative management of knee osteoarthritis. Experts with backgrounds in clinical medicine, research, implementation, or health informatics suggested the most important recommendations for implementation, how to develop an implementation strategy, and how to form the CDS algorithms. In 6 focus group sessions, 8 general practitioners and 22 patients from Norway, Belgium, and Finland discussed the suggested CDS intervention and identified factors that would be most critical for the success of the intervention. The focus group moderators used the GUideline Implementation with DEcision Support checklist, which we developed to support consideration of CDS success factors. The experts prioritized 9 out of 22 recommendations for implementation. We formed the concept for 6 CDS algorithms to support implementation of these recommendations. The focus group suggested 59 unique factors that could affect the success of the presented CDS intervention. Five factors (out of the 59) were prioritized by focus group participants in every country, including the perceived potential to address the information needs of both patients and general practitioners; the credibility of CDS information; the timing of CDS for patients; and the need for personal dialogue about CDS between the general practitioner and the patient. The focus group participants supported the CDS intervention as a tool to improve the quality of care for patients with knee osteoarthritis through shared, evidence-based decision making. We aim to develop and implement the CDS based on these study results. Future research should address optimal ways to (1) provide patient-directed CDS, (2) enable more patient-specific CDS within the context of patient complexity, and (3) maintain user engagement with CDS over time. ©Stijn Van de Velde, Tiina Kortteisto, David Spitaels, Gro Jamtvedt, Pavel Roshanov, Ilkka Kunnamo, Bert Aertgeerts, Per Olav Vandvik, Signe Flottorp. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 11.06.2018.

Doxorubicin conjugated functionalizable carbon dots for nucleus targeted delivery and enhanced therapeutic efficacy

NASA Astrophysics Data System (ADS)

Yang, Lei; Wang, Zheran; Wang, Ju; Jiang, Weihua; Jiang, Xuewei; Bai, Zhaoshi; He, Yunpeng; Jiang, Jianqi; Wang, Dongkai; Yang, Li

2016-03-01

Carbon dots (CDs) have shown great potential in imaging and drug/gene delivery applications. In this work, CDs functionalized with a nuclear localization signal peptide (NLS-CDs) were employed to transport doxorubicin (DOX) into cancer cells for enhanced antitumor activity. DOX was coupled to NLS-CDs (DOX-CDs) through an acid-labile hydrazone bond, which was cleavable in the weakly acidic intracellular compartments. The cytotoxicity of DOX-CD complexes was evaluated by the MTT assay and the cellular uptake was monitored using flow cytometry and confocal laser scanning microscopy. Cell imaging confirmed that DOX-CDs were mainly located in the nucleus. Furthermore, the complexes could efficiently induce apoptosis in human lung adenocarcinoma A549 cells. The in vivo therapeutic efficacy of DOX-CDs was investigated in an A549 xenograft nude mice model and the complexes exhibited an enhanced ability to inhibit tumor growth compared with free DOX. Thus, the DOX-CD conjugates may be exploited as promising drug delivery vehicles in cancer therapy.Carbon dots (CDs) have shown great potential in imaging and drug/gene delivery applications. In this work, CDs functionalized with a nuclear localization signal peptide (NLS-CDs) were employed to transport doxorubicin (DOX) into cancer cells for enhanced antitumor activity. DOX was coupled to NLS-CDs (DOX-CDs) through an acid-labile hydrazone bond, which was cleavable in the weakly acidic intracellular compartments. The cytotoxicity of DOX-CD complexes was evaluated by the MTT assay and the cellular uptake was monitored using flow cytometry and confocal laser scanning microscopy. Cell imaging confirmed that DOX-CDs were mainly located in the nucleus. Furthermore, the complexes could efficiently induce apoptosis in human lung adenocarcinoma A549 cells. The in vivo therapeutic efficacy of DOX-CDs was investigated in an A549 xenograft nude mice model and the complexes exhibited an enhanced ability to inhibit tumor growth compared with free DOX. Thus, the DOX-CD conjugates may be exploited as promising drug delivery vehicles in cancer therapy. Electronic supplementary information (ESI) available: FT-IR and 1H NMR spectra of DOX-CD complexes. See DOI: 10.1039/c6nr00247a

Radio haloes in nearby galaxies modelled with 1D cosmic ray transport using SPINNAKER

NASA Astrophysics Data System (ADS)

Heesen, V.; Krause, M.; Beck, R.; Adebahr, B.; Bomans, D. J.; Carretti, E.; Dumke, M.; Heald, G.; Irwin, J.; Koribalski, B. S.; Mulcahy, D. D.; Westmeier, T.; Dettmar, R.-J.

2018-05-01

We present radio continuum maps of 12 nearby (D ≤ 27 Mpc), edge-on (i ≥ 76°), late-type spiral galaxies mostly at 1.4 and 5 GHz, observed with the Australia Telescope Compact Array, Very Large Array, Westerbork Synthesis Radio Telescope, Effelsberg 100-m, and Parkes 64-m telescopes. All galaxies show clear evidence of radio haloes, including the first detection in the Magellanic-type galaxy NGC 55. In 11 galaxies, we find a thin and a thick disc that can be better fitted by exponential rather than Gaussian functions. We fit our SPINNAKER (SPectral INdex Numerical Analysis of K(c)osmic-ray Electron Radio-emission) 1D cosmic ray transport models to the vertical model profiles of the non-thermal intensity and to the non-thermal radio spectral index in the halo. We simultaneously fit for the advection speed (or diffusion coefficient) and magnetic field scale height. In the thick disc, the magnetic field scale heights range from 2 to 8 kpc with an average across the sample of 3.0 ± 1.7 kpc; they show no correlation with either star formation rate (SFR), SFR surface density (ΣSFR), or rotation speed (Vrot). The advection speeds range from 100 to 700 km s - 1 and display correlations of V∝SFR0.36 ± 0.06 and V∝ Σ _SFR^{0.39± 0.09}; they agree remarkably well with the escape velocities (0.5 ≤ V/Vesc ≤ 2), which can be explained by cosmic ray-driven winds. Radio haloes show the presence of disc winds in galaxies with ΣSFR > 10 - 3 M⊙ yr - 1 kpc - 2 that extend over several kpc and are driven by processes related to the distributed star formation in the disc.

Critically re-evaluating a common technique: Accuracy, reliability, and confirmation bias of EMG.

PubMed

Narayanaswami, Pushpa; Geisbush, Thomas; Jones, Lyell; Weiss, Michael; Mozaffar, Tahseen; Gronseth, Gary; Rutkove, Seward B

2016-01-19

(1) To assess the diagnostic accuracy of EMG in radiculopathy. (2) To evaluate the intrarater reliability and interrater reliability of EMG in radiculopathy. (3) To assess the presence of confirmation bias in EMG. Three experienced academic electromyographers interpreted 3 compact discs with 20 EMG videos (10 normal, 10 radiculopathy) in a blinded, standardized fashion without information regarding the nature of the study. The EMGs were interpreted 3 times (discs A, B, C) 1 month apart. Clinical information was provided only with disc C. Intrarater reliability was calculated by comparing interpretations in discs A and B, interrater reliability by comparing interpretation between reviewers. Confirmation bias was estimated by the difference in correct interpretations when clinical information was provided. Sensitivity was similar to previous reports (77%, confidence interval [CI] 63%-90%); specificity was 71%, CI 56%-85%. Intrarater reliability was good (κ 0.61, 95% CI 0.41-0.81); interrater reliability was lower (κ 0.53, CI 0.35-0.71). There was no substantial confirmation bias when clinical information was provided (absolute difference in correct responses 2.2%, CI -13.3% to 17.7%); the study lacked precision to exclude moderate confirmation bias. This study supports that (1) serial EMG studies should be performed by the same electromyographer since intrarater reliability is better than interrater reliability; (2) knowledge of clinical information does not bias EMG interpretation substantially; (3) EMG has moderate diagnostic accuracy for radiculopathy with modest specificity and electromyographers should exercise caution interpreting mild abnormalities. This study provides Class III evidence that EMG has moderate diagnostic accuracy and specificity for radiculopathy. © 2015 American Academy of Neurology.

The shape of the cosmic X-ray background: nuclear starburst discs and the redshift evolution of AGN obscuration

NASA Astrophysics Data System (ADS)

Gohil, R.; Ballantyne, D. R.

2018-04-01

A significant number of active galactic nuclei (AGNs) are observed to be hidden behind dust and gas. The distribution of material around AGNs plays an important role in modelling the cosmic X-ray background (CXB), especially the fraction of type 2 AGNs (f2). One of the possible explanations for obscuration in Seyfert galaxies at intermediate redshifts is dusty starburst discs. We compute the two-dimensional (2D) hydrostatic structure of 768 nuclear starburst discs (NSDs) under various physical conditions and also the distribution of column density along the line of sight (NH) associated with these discs. Then the NH distribution is evolved with redshift by using the redshift-dependent distribution function of input parameters. Parameter f2 shows a strong positive evolution up to z = 2, but only a weak level of enhancement at higher z. The Compton-thin and Compton-thick AGN fractions associated with these starburst regions increase ∝ (1 + z)δ, where δ is estimated to be 1.12 and 1.45, respectively. The reflection parameter Rf associated with column density NH ≥ 1023.5 cm-2 extends from 0.13 at z = 0 to 0.58 at z = 4. A CXB model employing this evolving NH distribution indicates that more compact (Rout < 120 pc) NSDs provide a better fit to the CXB. In addition to `Seyfert-like' AGNs obscured by nuclear starbursts, we predict that 40-60 per cent of quasars must be Compton-thick to produce a peak of the CXB spectrum within the observational uncertainty. The predicted total number counts of AGNs in 8-24 keV bands are in fair agreement with observations from the Nuclear Spectroscopic Telescope Array (NuSTAR).

The initial mass function and star formation law in the outer disc of NGC 2915

NASA Astrophysics Data System (ADS)

Bruzzese, S. M.; Meurer, G. R.; Lagos, C. D. P.; Elson, E. C.; Werk, J. K.; Blakeslee, John P.; Ford, H.

2015-02-01

Using Hubble Space Telescope (HST) Advanced Camera for Surveys/Wide Field Camera data we present the photometry and spatial distribution of resolved stellar populations in the outskirts of NGC 2915, a blue compact dwarf with an extended H I disc. These observations reveal an elliptical distribution of red giant branch stars, and a clumpy distribution of main-sequence stars that correlate with the H I gas distribution. We constrain the upper-end initial mass function (IMF) and determine the star formation law (SFL) in this field, using the observed main-sequence stars and an assumed constant star formation rate. Previously published Hα observations of the field, which show one faint H II region, are used to provide further constraints on the IMF. We find that the main-sequence luminosity function analysis alone results in a best-fitting IMF with a power-law slope α = -2.85 and upper-mass limit M_u = 60 M_{⊙}. However, if we assume that all Hα emission is confined to H II regions then the upper-mass limit is restricted to M_u ≲ 20 M_{⊙}. For the luminosity function fit to be correct, we have to discount the Hα observations implying significant diffuse ionized gas or escaping ionizing photons. Combining the HST photometry with H I imaging, we find the SFL has a power-law index N = 1.53 ± 0.21. Applying these results to the entire outer H I disc indicates that it contributes 11-28 per cent of the total recent star formation in NGC 2915, depending on whether the IMF is constant within the disc or varies from the centre to the outer region.

Critically re-evaluating a common technique

PubMed Central

Geisbush, Thomas; Jones, Lyell; Weiss, Michael; Mozaffar, Tahseen; Gronseth, Gary; Rutkove, Seward B.

2016-01-01

Objectives: (1) To assess the diagnostic accuracy of EMG in radiculopathy. (2) To evaluate the intrarater reliability and interrater reliability of EMG in radiculopathy. (3) To assess the presence of confirmation bias in EMG. Methods: Three experienced academic electromyographers interpreted 3 compact discs with 20 EMG videos (10 normal, 10 radiculopathy) in a blinded, standardized fashion without information regarding the nature of the study. The EMGs were interpreted 3 times (discs A, B, C) 1 month apart. Clinical information was provided only with disc C. Intrarater reliability was calculated by comparing interpretations in discs A and B, interrater reliability by comparing interpretation between reviewers. Confirmation bias was estimated by the difference in correct interpretations when clinical information was provided. Results: Sensitivity was similar to previous reports (77%, confidence interval [CI] 63%–90%); specificity was 71%, CI 56%–85%. Intrarater reliability was good (κ 0.61, 95% CI 0.41–0.81); interrater reliability was lower (κ 0.53, CI 0.35–0.71). There was no substantial confirmation bias when clinical information was provided (absolute difference in correct responses 2.2%, CI −13.3% to 17.7%); the study lacked precision to exclude moderate confirmation bias. Conclusions: This study supports that (1) serial EMG studies should be performed by the same electromyographer since intrarater reliability is better than interrater reliability; (2) knowledge of clinical information does not bias EMG interpretation substantially; (3) EMG has moderate diagnostic accuracy for radiculopathy with modest specificity and electromyographers should exercise caution interpreting mild abnormalities. Classification of evidence: This study provides Class III evidence that EMG has moderate diagnostic accuracy and specificity for radiculopathy. PMID:26701380

Effects of local thermodynamics and of stellar mass ratio on accretion disc stability in close binaries

NASA Astrophysics Data System (ADS)

Lanzafame, G.

2009-08-01

Inflow kinematics at the inner Lagrangian point L1, gas compressibility, and physical turbulent viscosity play a fundamental role on accretion disc dynamics and structure in a close binary (CB). Physical viscosity supports the accretion disc development inside the primary gravitational potential well, developing the gas radial transport, converting mechanical energy into heat. The Stellar-Mass-Ratio (SMR) between the compact primary and the secondary star (M1/M2) is also effective, not only in the location of the inner Lagrangian point, but also in the angular kinematics of the mass transfer and in the geometry of the gravitational potential wells. In this work we pay attention in particular to the role of the SMR, evaluating boundaries, separating theoretical domains in compressibility-viscosity graphs where physical conditions allow a well-bound disc development, as a function of mass transfer kinematic conditions. In such domains, the lower is the gas compressibility (the higher the polytropic index γ), the higher is the physical viscosity (α) requested. In this work, we show how the boundaries of such domains vary as a function of M1/M2. Conclusions as far as dwarf novae outbursts are concerned, induced by mass transfer rate variations, are also reported. The smaller M1/M2, the shorter the duration of the active-to-quiet and vice-versa transitional phases. Time-scales are of the order of outburst duration of SU Uma, OY Car, Z Cha and SS Cyg-like objects. Moreover, conclusions as far as active-quiet-active phenomena in a CB, according to viscous-thermal instabilities, in accordance to such domains, are also reported.

Facile synthesis of silver nanoparticles/carbon dots for a charge transfer study and peroxidase-like catalytic monitoring by surface-enhanced Raman scattering

NASA Astrophysics Data System (ADS)

Zhao, Hongyue; Guo, Yue; Zhu, Shoujun; Song, Yubin; Jin, Jing; Ji, Wei; Song, Wei; Zhao, Bing; Yang, Bai; Ozaki, Yukihiro

2017-07-01

In this work, carbon dots (CDs) were combined with Ag nanoparticles (NPs) by a chemical reaction to form Ag NPs/CDs hybrid, which was then used as a novel surface-enhanced Raman scattering (SERS) substrate. During the synthetic process, carboxyl groups on the surface of Ag NPs were reacted with amino groups of CDs in an amidation reaction. The D and G bands of CDs in the Ag NPs/CDs hybrid could be easily detected by SERS. By employing p-aminothiophenol (PATP) molecules as SERS probes, the Ag NPs/CDs hybrid substrate could detect PATP in diluted solutions of concentration as low as 10-9 M. The charge transfer (CT) effect on SERS spectra with different excitation wavelengths in the prepared Ag NPs/CDs hybrid and PATP system was also investigated. It was found that addition of CDs changes the degree of CT between Ag NPs and PATP molecules. Since the prepared Ag NPs/CDs hybrid also showed a peroxidase-like activity toward the oxidation of 3,3‧,5,5‧-tetramethylbenzidine using H2O2, which can provide the sensitive detection of H2O2 by SERS technique.

Optimal nitrogen and phosphorus codoping carbon dots towards white light-emitting device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Feng; Wang, Yaling; Miao, Yanqin

Through a one-step fast microwave-assisted approach, nitrogen and phosphorus co-doped carbon dots (N,P-CDs) were synthesized using ammonium citrate (AC) as a carbon source and phosphates as additive reagent. Under the condition of an optimal reaction time of 140 s, the influence of additive with different N and P content on fluorescent performance of N,P-CDs was further explored. It was concluded that high nitrogen content and moderate phosphorus content are necessary for obtaining high quantum yield (QY) N,P-CDs, among which the TAP-CDs (CDs synthesized using ammonium phosphate as additive reagent) show high quantum yield (QY) of 62% and red-green-blue (RGB) spectral compositionmore » of 51.67%. Besides, the TAP-CDs exhibit satisfying thermal stability within 180 °C. By virtue of good optical and thermal properties of TAP-CDs, a white light-emitting device (LED) was fabricated by combining ultraviolet chip with TAP-CDs as phosphor. The white LED emits bright warm-white light with the CIE chromaticity coordinate of (0.38, 0.35) and the corresponding color temperature (CCT) of 4450 K, indicating the potential of TAP-CDs phosphor in white LED.« less

Highly Efficient Carbon Dots with Reversibly Switchable Green-Red Emissions for Trichromatic White Light-Emitting Diodes.

PubMed

Yuan, Biao; Guan, Shanyue; Sun, Xingming; Li, Xiaoming; Zeng, Haibo; Xie, Zheng; Chen, Ping; Zhou, Shuyun

2018-05-09

Carbon dots (CDs) have potentials to be utilized in optoelectronic devices, bioimaging, and photocatalysis. The majority of the current CDs with high quantum yield to date were limited in the blue light emission region. Herein, on the basis of surface electron-state engineering, we report a kind of CDs with reversible switching ability between green and red photoluminescence with a quantum yield (QY) of both up to 80%. Highly efficient green and red solid-state luminescence is realized by doping CDs into a highly transparent matrix of methyltriethoxysilane and 3-triethoxysilylpropylamine to form CDs/gel glasses composites with QYs of 80 and 78%. The CDs/gel glasses show better transmittance in visible light bands and excellent thermal stability. A blue-pumped CDs/gel glasses phosphor-based trichromatic white light-emitting diode (WLED) is realized, whose color rendering index is 92.9. The WLED gets the highest luminous efficiency of 71.75 lm W -1 in CDs-based trichromatic WLEDs. This work opens a door for developing highly efficient green- and red-emissive switching CDs which were used as phosphors for WLEDs and have the tendency for applications in other fields, such as sensing, bioimaging, and photocatalysis.

Design and Development of a Sharable Clinical Decision Support System Based on a Semantic Web Service Framework.

PubMed

Zhang, Yi-Fan; Gou, Ling; Tian, Yu; Li, Tian-Chang; Zhang, Mao; Li, Jing-Song

2016-05-01

Clinical decision support (CDS) systems provide clinicians and other health care stakeholders with patient-specific assessments or recommendations to aid in the clinical decision-making process. Despite their demonstrated potential for improving health care quality, the widespread availability of CDS systems has been limited mainly by the difficulty and cost of sharing CDS knowledge among heterogeneous healthcare information systems. The purpose of this study was to design and develop a sharable clinical decision support (S-CDS) system that meets this challenge. The fundamental knowledge base consists of independent and reusable knowledge modules (KMs) to meet core CDS needs, wherein each KM is semantically well defined based on the standard information model, terminologies, and representation formalisms. A semantic web service framework was developed to identify, access, and leverage these KMs across diverse CDS applications and care settings. The S-CDS system has been validated in two distinct client CDS applications. Model-level evaluation results confirmed coherent knowledge representation. Application-level evaluation results reached an overall accuracy of 98.66 % and a completeness of 96.98 %. The evaluation results demonstrated the technical feasibility and application prospect of our approach. Compared with other CDS engineering efforts, our approach facilitates system development and implementation and improves system maintainability, scalability and efficiency, which contribute to the widespread adoption of effective CDS within the healthcare domain.

SSBRP User Operations Facility (UOF) Overview and Development Strategy

NASA Technical Reports Server (NTRS)

Picinich, Lou; Stone, Thom; Sun, Charles; Windrem, May; Givens, John J. (Technical Monitor)

1995-01-01

This paper will present the Space Station Biological Research Project (SSBRP) User Operations Facility (UOF) architecture and development strategy. A major element of the UOF at NASA Ames Research Center, the Communication and Data System (CDS) will be the primary focus of the discussions. CDS operational, telescience, security, and development objectives will be discussed along with CDS implementation strategy. The implementation strategy discussions will include: Object Oriented Analysis & Design, System & Software Prototyping, and Technology Utilization. A CDS design overview that includes: CDS Context Diagram, CDS Architecture, Object Models, Use Cases, and User Interfaces will also be presented. CDS development brings together "cutting edge" technologies and techniques such as: object oriented development, network security, multimedia networking, web-based data distribution, JAVA, and graphical user interfaces. Use of these "cutting edge" technologies and techniques translates directly to lower development and operations costs.

Blocking the Formation of Zn2+/Dye Complexes in Dye-Sensitized Solar Cells by Inserting CdS Quantum Dots into Sandwich Layer

NASA Astrophysics Data System (ADS)

Sun, Yunfei; Liu, Chunling; Yang, Lili; Wei, Maobin; Lv, Shiquan; Sui, Yingrui; Cao, Jian; Chen, Gang; Yang, Jinghai

2018-06-01

ZnO NRAs are grown on ITO substrates by a simple chemical method. CdS QDs were deposited on ZnO NRAs by SILAR. N719 was synthesized by dipping method. J-V analysis indicates that by inserting a layer of CdS QDs, the conversion efficiency of DSSCs was improved obviously. The device with CdS QDs shows the higher conversion efficiency due to the three reasons: (1) CdS QDs enhanced adsorption spectra of DSSCs in the visible region; (2) CdS QDs block the formation of Zn2+/dye complex, it is beneficial for electros transport from dye to ZnO photoanode. It is the key to obtain higher conversion efficiency; (3) FRET dynamics exists by the introduction of CdS QDs.

Facile and eco-friendly synthesis of green fluorescent carbon nanodots for applications in bioimaging, patterning and staining

NASA Astrophysics Data System (ADS)

Shi, Lihong; Li, Yanyan; Li, Xiaofeng; Wen, Xiangping; Zhang, Guomei; Yang, Jun; Dong, Chuan; Shuang, Shaomin

2015-04-01

We report a facile and eco-friendly strategy for the fabrication of green fluorescent carbon nanodots (CDs), and demonstrate their applications for bio-imaging, patterning, and staining. A one-pot hydrothermal method using various plant petals yields bright green-emitting CDs, providing an easy way for the production of green fluorescent CDs without the need for a tedious synthetic methodology or the use of toxic/expensive solvents and starting materials. The as-prepared CDs show small size distribution and excellent dispersibility. Their strong green fluorescence is observed when the excitation wavelength is between 430 nm and 490 nm. Moreover, they exhibit high tolerance to various external conditions, such as pH values, external cations, and continuous excitation. Due to minimum toxicity as well as good photoluminescence properties, these CDs can be applied to in vitro and in vivo imaging, patterning, and staining. According to confocal fluorescence imaging of human uterine cervical squamous cell carcinoma cells, CDs penetrate into the cell and enter the cytoplasm and the nucleus. More strikingly, carp is directly fed with CDs for in vivo imaging and shows bright green fluorescence at an excitation wavelength of 470 nm. In addition, the obtained CDs are used as fluorescent inks for drawing luminescence patterns. Finally, we also apply the CDs as a fluorescent dye. Interestingly, the absorbent filter paper with staining emits dramatic fluorescence under 470 nm excitation.We report a facile and eco-friendly strategy for the fabrication of green fluorescent carbon nanodots (CDs), and demonstrate their applications for bio-imaging, patterning, and staining. A one-pot hydrothermal method using various plant petals yields bright green-emitting CDs, providing an easy way for the production of green fluorescent CDs without the need for a tedious synthetic methodology or the use of toxic/expensive solvents and starting materials. The as-prepared CDs show small size distribution and excellent dispersibility. Their strong green fluorescence is observed when the excitation wavelength is between 430 nm and 490 nm. Moreover, they exhibit high tolerance to various external conditions, such as pH values, external cations, and continuous excitation. Due to minimum toxicity as well as good photoluminescence properties, these CDs can be applied to in vitro and in vivo imaging, patterning, and staining. According to confocal fluorescence imaging of human uterine cervical squamous cell carcinoma cells, CDs penetrate into the cell and enter the cytoplasm and the nucleus. More strikingly, carp is directly fed with CDs for in vivo imaging and shows bright green fluorescence at an excitation wavelength of 470 nm. In addition, the obtained CDs are used as fluorescent inks for drawing luminescence patterns. Finally, we also apply the CDs as a fluorescent dye. Interestingly, the absorbent filter paper with staining emits dramatic fluorescence under 470 nm excitation. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr00783f

Translation and validation of the Cardiac Depression Scale to Arabic.

PubMed

Papasavvas, T; Al-Amin, H; Ghabrash, H F; Micklewright, D

2016-08-01

The Cardiac Depression Scale (CDS) has been designed to measure depressive symptoms in patients with heart disease. There is no Arabic version of the CDS. We translated and validated the CDS in an Arabic sample of patients with heart disease. Forward and back translation of the CDS was followed by assessment of cultural relevance and content validity. The Arabic version of the CDS (A-CDS) and the Arabic version of the Hospital Anxiety and Depression Scale (A-HADS) were then administered to 260 Arab in-patients with heart disease from 18 Arabic countries. Construct validity was assessed using exploratory factor analysis with polychoric correlations. Internal consistency was assessed using ordinal reliability alpha and item-to-factor polychoric correlations. Concurrent validity was assessed using Pearson's correlation coefficient between the A-CDS and the depression subscale of the A-HADS (A-HADS-D). Cultural relevance and content validity of the A-CDS were satisfactory. Exploratory factor analysis revealed three robust factors, without cross-loadings, that formed a single dimension. Internal consistency was high (ordinal reliability alpha for the total scale and the three factors were .94, .91, .86, and .87, respectively; item-to-factor correlations ranged from .77 to .91). Concurrent validity was high (r=.72). The A-CDS demonstrated a closer to normal distribution of scores than the A-HADS-D. Sensitivity and specificity of the A-CDS were not objectively assessed. The A-CDS appears to be a valid and reliable instrument to measure depressive symptoms in a representative sample of Arab in-patients with heart disease. Copyright © 2016 Elsevier B.V. All rights reserved.

Quality of ground water used for selected municipal water supplies in Iowa, 1982-96 water years

USGS Publications Warehouse

Schaap, B.D.; Linhart, S.M.

1998-01-01

Maps show the general location of wells that have been sampled in the various aquifers. Other maps show the location of wells where sulfate and nitrite plus nitrate concentrations exceed the respective Maximum Contaminant Levels and wells where concentrations of the pesticides alachlor, atrazine, or cyanazine exceeded the respective minimum reporting levels. The compact disc included with this report has information about water-quality properties and concentrations of dissolved solids, major ions, nutrients, trace elements, radionuclides, total organic carbon, pesticides, and synthetic organic compounds for water years 1982 through 1996.

Asymptotic Behaviour of the Ground State of Singularly Perturbed Elliptic Equations

NASA Astrophysics Data System (ADS)

Piatnitski, Andrey L.

The ground state of a singularly perturbed nonselfadjoint elliptic operator defined on a smooth compact Riemannian manifold with metric aij(x)=(aij(x))-1, is studied. We investigate the limiting behaviour of the first eigenvalue of this operator as μ goes to zero, and find the logarithmic asymptotics of the first eigenfunction everywhere on the manifold. The results are formulated in terms of auxiliary variational problems on the manifold. This approach also allows to study the general singularly perturbed second order elliptic operator on a bounded domain in Rn.

Compact, high energy gas laser

DOEpatents

Rockwood, Stephen D.; Stapleton, Robert E.; Stratton, Thomas F.

1976-08-03

An electrically pumped gas laser amplifier unit having a disc-like configuration in which light propagation is radially outward from the axis rather than along the axis. The input optical energy is distributed over a much smaller area than the output optical energy, i.e., the amplified beam, while still preserving the simplicity of parallel electrodes for pumping the laser medium. The system may thus be driven by a comparatively low optical energy input, while at the same time, owing to the large output area, large energies may be extracted while maintaining the energy per unit area below the threshold of gas breakdown.

Herschel GASPS spectral observations of T Tauri stars in Taurus. Unraveling far-infrared line emission from jets and discs

NASA Astrophysics Data System (ADS)

Alonso-Martínez, M.; Riviere-Marichalar, P.; Meeus, G.; Kamp, I.; Fang, M.; Podio, L.; Dent, W. R. F.; Eiroa, C.

2017-07-01

Context. At early stages of stellar evolution young stars show powerful jets and/or outflows that interact with protoplanetary discs and their surroundings. Despite the scarce knowledge about the interaction of jets and/or outflows with discs, spectroscopic studies based on Herschel and ISO data suggests that gas shocked by jets and/or outflows can be traced by far-IR (FIR) emission in certain sources. Aims: We want to provide a consistent catalogue of selected atomic ([OI] and [CII]) and molecular (CO, H2O, and OH) line fluxes observed in the FIR, separate and characterize the contribution from the jet and the disc to the observed line emission, and place the observations in an evolutionary picture. Methods: The atomic and molecular FIR (60-190 μm) line emission of protoplanetary discs around 76 T Tauri stars located in Taurus are analysed. The observations were carried out within the Herschel key programme Gas in Protoplanetary Systems (GASPS). The spectra were obtained with the Photodetector Array Camera and Spectrometer (PACS). The sample is first divided in outflow and non-outflow sources according to literature tabulations. With the aid of archival stellar/disc and jet/outflow tracers and model predictions (PDRs and shocks), correlations are explored to constrain the physical mechanisms behind the observed line emission. Results: Outflow sources exhibit brighter atomic and molecular emission lines and higher detection rates than non-outflow sources. The line detection fractions decrease with SED evolutionary status (from Class I to Class III). We find correlations between [OI] 63.18 μm and [OI] 6300 Å, o-H2O 78.74 μm, CO 144.78 μm, OH 79.12+79.18 μm, and the continuum flux at 24 μm. The atomic line ratios can be explain either by fast (Vshock > 50 km s-1) dissociative J-shocks at low densities (n 103 cm-3) occurring along the jet and/or PDR emission (G0 > 102, n 103-106 cm-3). To account for the [CII] absolute fluxes, PDR emission or UV irradiation of shocks is needed. In comparison, the molecular emission is more compact and the line ratios are better explained with slow (Vshock < 40 km s-1) C-type shocks with high pre-shock densities (104-106 cm-3), with the exception of OH lines, that are better described by J-type shocks. Disc models alone fail to reproduce the observed molecular line fluxes, but a contribution to the line fluxes from UV-illuminated discs and/or outflow cavities is expected. Far-IR lines dominate disc cooling at early stages and weaken as the star+disc system evolves from Class I to Class III, with an increasing relative disc contribution to the line fluxes. Conclusions: Models which take into account jets, discs, and their mutual interaction are needed to disentangle the different components and study their evolution. The much higher detection rate of emission lines in outflow sources and the compatibility of line ratios with shock model predictions supports the idea of a dominant contribution from the jet/outflow to the line emission, in particular at earlier stages of the stellar evolution as the brightness of FIR lines depends in large part on the specific evolutionary stage. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

Facile synthesis of fluorescence carbon dots from sweet potato for Fe3+ sensing and cell imaging.

PubMed

Shen, Jie; Shang, Shaoming; Chen, Xiuying; Wang, Dan; Cai, Yan

2017-07-01

In this study, a facile synthesis of fluorescence carbon dots (CDs) from sweet potato was performed through hydrothermal treatment. The obtained CDs with quantum yield of 8.64% have good dispersibility due to the soluble functional groups on their surfaces. The characterization of CDs was carried out and their possible formation mechanism was also discussed. In addition, the cytotoxicity results showed that the CDs exhibit non toxicity within 100μg/mL. At this concentration, the CDs were applied in cell imaging, indicating that they are promising fluorescent probes for biological imaging. In addition, the fluorescence of CDs was quenched by Fe 3+ with a linear concentration of 1 to 100μM, associated with the limit of detection of 0.32μM. Subsequently, the CDs were successfully applied for Fe 3+ probing in living cells. Copyright © 2017 Elsevier B.V. All rights reserved.

Red, green, and blue luminescence by carbon dots: full-color emission tuning and multicolor cellular imaging.

PubMed

Jiang, Kai; Sun, Shan; Zhang, Ling; Lu, Yue; Wu, Aiguo; Cai, Congzhong; Lin, Hengwei

2015-04-27

A facile approach for preparation of photoluminescent (PL) carbon dots (CDs) is reported. The three resulting CDs emit bright and stable red, green and blue (RGB) colors of luminescence, under a single ultraviolet-light excitation. Alterations of PL emission of these CDs are tentatively proposed to result from the difference in their particle size and nitrogen content. Interestingly, up-conversion (UC)PL of these CDs is also observed. Moreover, flexible full-color emissive PVA films can be achieved through mixing two or three CDs in the appropriate ratios. These CDs also show low cytotoxicity and excellent cellular imaging capability. The facile preparation and unique optical features make these CDs potentially useful in numerous applications such as light-emitting diodes, full-color displays, and multiplexed (UC)PL bioimaging. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photo current generation in RGO - CdS nanorod thin film device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chakraborty, Koushik; Chakrabarty, Sankalpita; Ibrahim, Sk.

2016-05-23

Herein, we report the synthesis and characterization of reduced graphene oxide (RGO) - cadmium sulfide (CdS) nanocomposite materials. The reduction of GO, formation of CdS and decoration of CdS onto RGO sheets were done in a one- pot solvothermal process. We have observed that the PL intensity for CdS nanorods remarkably quenched after the attachment of RGO, which established the photo induced charge transformation from the CdS nanorod to RGO sheets through the RGO-CdS interface. The optoelectronic transport properties of our fabricated large area thin film device exhibits excellent photo induced charge generation under simulated solar light illumination. The photomore » sensitivity of the device increases linearly with the increase of illuminated light intensity. The RGO-CdS composite exhibits enhance photocatalytic dye degradation efficiency in compare to control CdS under simulated solar light illumination.« less

A Second Life for CDs

ERIC Educational Resources Information Center

Snoderly, Kathleen

2011-01-01

Cutting a few CDs apart with scissors, the author found that the process created somewhat brittle shards. As a result, she started to paint a few with acrylic, finding to her amazement that the paint gave the CDs a leathery, more manageable texture. Upon further experimentation, she found that if the CDs are painted somewhat translucently in…

77 FR 13668 - Self-Regulatory Organizations; Chicago Mercantile Exchange, Inc.; Order Approving Proposed Rule...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-07

... calculates each CDS Clearing Member's allocation to the CDS Guaranty Fund, with a new standard that CME believes better allocates tail risk. Currently CME rules provide that each CDS Clearing Member's allocation... that the allocation will be made on the basis of each CDS Clearing Member's potential residual loss...

Improved delivery through biological membranes. XXXL: Solubilization and stabilization of an estradiol chemical delivery system by modified beta-cyclodextrins.

PubMed

Brewster, M E; Estes, K S; Loftsson, T; Perchalski, R; Derendorf, H; Mullersman, G; Bodor, N

1988-11-01

A dihydropyridine in equilibrium pyridinium salt chemical delivery system (CDS) for estradiol (E2CDS) was complexed with various modified beta-cyclodextrins including hydroxyethyl-beta-cyclodextrin (HECD), hydroxypropyl-beta-cyclodextrin (HPCD), and heptakis(2,6-di-O-methyl)-beta-cyclodextrin (DMCD). Complex formation with all of these cyclodextrins resulted in dramatic increases in the water solubility of E2CDS. Studies on the complex of E2CDS and HPCD (E2CDS-CD) indicated that the encapsulated estrogen was approximately four times more stable than the unmanipulated CDS, producing an estimated half-life of degradation of 4 years compared with 1.2 years for the uncomplexed drug at room temperature. The complexation of E2CDS and HPCD also stabilized the dihydronicotinate in solutions containing potassium ferricyanide. This formulation was shown to be equivalent to E2CDS in dimethyl sulfoxide in delivering the oxidized, estradiol precursor (E2Q+) to the brain, and also produced similar biological responses; these included decreased luteinizing hormone (LH) secretion and a decrease in the rate of weight gain in castrated female rats.

High fidelity polycrystalline CdTe/CdS heterostructures via molecular dynamics

DOE PAGES

Aguirre, Rodolfo; Chavez, Jose Juan; Zhou, Xiaowang; ...

2017-06-20

Molecular dynamics simulations of polycrystalline growth of CdTe/CdS heterostructures have been performed. First, CdS was deposited on an amorphous CdS substrate, forming a polycrystalline film. Subsequently, CdTe was deposited on top of the polycrystalline CdS film. Cross-sectional images show grain formation at early stages of the CdS growth. During CdTe deposition, the CdS structure remains almost unchanged. Concurrently, CdTe grain boundary motion was detected after the first 24.4 nanoseconds of CdTe deposition. With the elapse of time, this grain boundary pins along the CdS/CdTe interface, leaving only a small region of epitaxial growth. CdTe grains are larger than CdS grainsmore » in agreement with experimental observations in the literature. Crystal phase analysis shows that zinc blende structure dominates over the wurtzite structure inside both CdS and CdTe grains. Composition analysis shows Te and S diffusion to the CdS and CdTe films, respectively. Lastly, these simulated results may stimulate new ideas for studying and improving CdTe solar cell efficiency.« less

Carbon dots decorated magnetic ZnFe2O4 nanoparticles with enhanced adsorption capacity for the removal of dye from aqueous solution

NASA Astrophysics Data System (ADS)

Shi, Weilong; Guo, Feng; Wang, Huibo; Liu, Changan; Fu, Yijun; Yuan, Songliu; Huang, Hui; Liu, Yang; Kang, Zhenhui

2018-03-01

Widely used synthetic dyes have been caused serious environmental pollution. Therefore, it is imperative to acquire highly efficient adsorbent to remove them. Here, we report the carbon dots/ZnFe2O4 (CDs/ZFO) composites were prepared through a facile hydrothermal route for absorption removal of dye from aqueous solution. The characterizations reveal the CDs were uniformly deposited on the surfaces of ZFO nanoparticles in the composite. The CDs/ZFO composites as adsorbents exhibit enhanced adsorption behavior for methyl orange (MO) in comparison of pristine ZFO, in which the 5% CDs/ZFO (with the CDs mass content of 5 wt%) shows the highest absorption activity. Experimental studies on adsorption isotherms of MO over the 5% CDs/ZFO composite indicate that experimental data were found to follow Langmuir model with a monolayer adsorption capacity of 181.2 mg g-1. The corresponding adsorption kinetics was fitted well with the pseudo-second-order kinetic model. Moreover, thermodynamics parameters including ΔG°, ΔH° and ΔS° were tested, demonstrating that the adsorption of MO over CDs/ZFO composite was spontaneous and exothermic in nature. The remarkably increased adsorption performance of CDs/ZFO composites can be attributed to abundant oxygen-containing groups on the surface of CDs.

Effects of bacteria on CdS thin films used in technological devices

NASA Astrophysics Data System (ADS)

Alpdoğan, S.; Adıgüzel, A. O.; Sahan, B.; Tunçer, M.; Metin Gubur, H.

2017-04-01

Cadmium sulfide (CdS) thin films were fabricated on glass substrates by the chemical bath deposition method at 70 {}^\\circ \\text{C} considering deposition times ranging from 2 h to 5 h. The optical band gaps of CdS thin films were found to be in the 2.42-2.37 eV range. CdS thin films had uniform spherical nano-size grains which had polycrystalline, hexagonal and cubic phases. The films had a characteristic electrical resistivity of the order of {{10}5} Ω \\text{cm} and n-type conductivity at room condition. CdS thin films were incubated in cultures of B.domonas aeruginosa and Staphylococcus aureus, which exist abundantly in the environment, and form biofilms. SEM images showed that S. aureus and K. pneumonia were detected significantly on the film surfaces with a few of P. aeruginosa and B. subtilis cells attached. CdS thin film surface exhibits relatively good resistance to the colonization of P. aeruginosa and B. subtilis. Optical results showed that the band gap of CdS thin films which interacted with the bacteria is 2.42 \\text{eV} . The crystal structure and electrical properties of CdS thin films were not affected by bacterial adhesion. The antimicrobial effect of CdS nanoparticles was different for different bacterial strains.

Controllable synthesis of green and blue fluorescent carbon nanodots for pH and Cu(2+) sensing in living cells.

PubMed

Shi, Lihong; Li, Yanyan; Li, Xiaofeng; Zhao, Bo; Wen, Xiangping; Zhang, Guomei; Dong, Chuan; Shuang, Shaomin

2016-03-15

We report a controllable strategy for fabrication of green and blue fluorescent carbon nanodots (CDs), and demonstrate their applications for pH and Cu(2+) sensing in living cells. Green and blue fluorescent CDs have been synthesized by hydrothermal method and pyrolysis of leeks, respectively, providing an easy way for the production of CDs without the request of tedious synthetic methodology or the use of toxic/expensive solvents and starting materials. Green fluorescent CDs (G-CDs) exhibit high tolerance to pH values and external cations. Blue fluorescent CDs (B-CDs) can be applied to pH and Cu(2+) sensing. The linear range of Cu(2+) detection is 0.01-10.00 μM and the detection limit is 0.05 μM. For pH detection, there is a good linearity in the pH range of 3.5-10.0. The linear and rapid response of B-CDs to Cu(2+) and pH is valuable for Cu(2+) and pH sensing in living cells. Confocal fluorescent imaging of human cervical carcinoma cells indicates that B-CDs could visualize Cu(2+) and pH fluctuations in living cells with negligible autofluorescence. Copyright © 2015 Elsevier B.V. All rights reserved.

In vivo characterization of hair and skin derived carbon quantum dots with high quantum yield as long-term bioprobes in zebrafish

PubMed Central

Zhang, Jing-Hui; Niu, Aping; Li, Jing; Fu, Jian-Wei; Xu, Qun; Pei, De-Sheng

2016-01-01

Carbon quantum dots (CDs) were widely investigated because of their tunable fluorescence properties and low toxicity. However, so far there have been no reports on in vivo functional studies of hair and skin derived CDs. Here, hair derived CDs (HCDs) and skin derived CDs (SCDs) were produced by using human hair and pig skin as precursors. The quantum yields (QYs) of HCDs and SCDs were quite high, compared to citric acid derived CDs (CCDs). HCDs and SCDs possess optimal photostability, hypotoxicity and biocompatibility in zebrafish, indicating that HCDs and SCDs possess the capacity of being used as fluorescence probes for in vivo biological imaging. The long-time observation for fluorescence alternation of CDs in zebrafish and the quenching assay of CDs by ATP, NADH and Fe3+ ions demonstrated that the decaying process of CDs in vivo might be induced by the synergistic effect of the metabolism process. All results indicated that large batches and high QYs of CDs can be acquired by employing natural and nontoxic hair and skin as precursors. To our knowledge, this is the first time to report SCDs, in vivo comparative studies of HCDs, SCDs and CCDs as bioprobes, and explore their mechanism of photostability in zebrafish. PMID:27886267

In vivo characterization of hair and skin derived carbon quantum dots with high quantum yield as long-term bioprobes in zebrafish.

PubMed

Zhang, Jing-Hui; Niu, Aping; Li, Jing; Fu, Jian-Wei; Xu, Qun; Pei, De-Sheng

2016-11-25

Carbon quantum dots (CDs) were widely investigated because of their tunable fluorescence properties and low toxicity. However, so far there have been no reports on in vivo functional studies of hair and skin derived CDs. Here, hair derived CDs (HCDs) and skin derived CDs (SCDs) were produced by using human hair and pig skin as precursors. The quantum yields (QYs) of HCDs and SCDs were quite high, compared to citric acid derived CDs (CCDs). HCDs and SCDs possess optimal photostability, hypotoxicity and biocompatibility in zebrafish, indicating that HCDs and SCDs possess the capacity of being used as fluorescence probes for in vivo biological imaging. The long-time observation for fluorescence alternation of CDs in zebrafish and the quenching assay of CDs by ATP, NADH and Fe 3+ ions demonstrated that the decaying process of CDs in vivo might be induced by the synergistic effect of the metabolism process. All results indicated that large batches and high QYs of CDs can be acquired by employing natural and nontoxic hair and skin as precursors. To our knowledge, this is the first time to report SCDs, in vivo comparative studies of HCDs, SCDs and CCDs as bioprobes, and explore their mechanism of photostability in zebrafish.

In vivo characterization of hair and skin derived carbon quantum dots with high quantum yield as long-term bioprobes in zebrafish

NASA Astrophysics Data System (ADS)

Zhang, Jing-Hui; Niu, Aping; Li, Jing; Fu, Jian-Wei; Xu, Qun; Pei, De-Sheng

2016-11-01

Carbon quantum dots (CDs) were widely investigated because of their tunable fluorescence properties and low toxicity. However, so far there have been no reports on in vivo functional studies of hair and skin derived CDs. Here, hair derived CDs (HCDs) and skin derived CDs (SCDs) were produced by using human hair and pig skin as precursors. The quantum yields (QYs) of HCDs and SCDs were quite high, compared to citric acid derived CDs (CCDs). HCDs and SCDs possess optimal photostability, hypotoxicity and biocompatibility in zebrafish, indicating that HCDs and SCDs possess the capacity of being used as fluorescence probes for in vivo biological imaging. The long-time observation for fluorescence alternation of CDs in zebrafish and the quenching assay of CDs by ATP, NADH and Fe3+ ions demonstrated that the decaying process of CDs in vivo might be induced by the synergistic effect of the metabolism process. All results indicated that large batches and high QYs of CDs can be acquired by employing natural and nontoxic hair and skin as precursors. To our knowledge, this is the first time to report SCDs, in vivo comparative studies of HCDs, SCDs and CCDs as bioprobes, and explore their mechanism of photostability in zebrafish.

A qualitative study of the activities performed by people involved in clinical decision support: recommended practices for success.

PubMed

Wright, Adam; Ash, Joan S; Erickson, Jessica L; Wasserman, Joe; Bunce, Arwen; Stanescu, Ana; St Hilaire, Daniel; Panzenhagen, Morgan; Gebhardt, Eric; McMullen, Carmit; Middleton, Blackford; Sittig, Dean F

2014-01-01

To describe the activities performed by people involved in clinical decision support (CDS) at leading sites. We conducted ethnographic observations at seven diverse sites with a history of excellence in CDS using the Rapid Assessment Process and analyzed the data using a series of card sorts, informed by Linstone's Multiple Perspectives Model. We identified 18 activities and grouped them into four areas. Area 1: Fostering relationships across the organization, with activities (a) training and support, (b) visibility/presence on the floor, (c) liaising between people, (d) administration and leadership, (e) project management, (f) cheerleading/buy-in/sponsorship, (g) preparing for CDS implementation. Area 2: Assembling the system with activities (a) providing technical support, (b) CDS content development, (c) purchasing products from vendors (d) knowledge management, (e) system integration. Area 3: Using CDS to achieve the organization's goals with activities (a) reporting, (b) requirements-gathering/specifications, (c) monitoring CDS, (d) linking CDS to goals, (e) managing data. Area 4: Participation in external policy and standards activities (this area consists of only a single activity). We also identified a set of recommendations associated with these 18 activities. All 18 activities we identified were performed at all sites, although the way they were organized into roles differed substantially. We consider these activities critical to the success of a CDS program. A series of activities are performed by sites strong in CDS, and sites adopting CDS should ensure they incorporate these activities into their efforts.

CdS-sensitized TiO2 nanocorals: hydrothermal synthesis, characterization, application.

PubMed

Mali, S S; Desai, S K; Dalavi, D S; Betty, C A; Bhosale, P N; Patil, P S

2011-10-01

Cadmium sulfide (CdS) nanoparticle-sensitized titanium oxide nanocorals (TNC) were synthesized using a two-step deposition process. The TiO(2) nanocorals were grown on the conducting glass substrates (FTO) using A hydrothermal process and CdS nanoparticles were loaded on TNC using successive ionic layer adsorption and reaction (SILAR) method. The TiO(2), CdS and TiO(2)-CdS samples were characterized by optical absorption, X-ray diffraction (XRD), FT-Raman, FT-IR, scanning electron microscopy (SEM) and contact angle. Further, their photoelectrochemical (PEC) performance was tested in NaOH, Na(2)S-NaOH-S and Na(2)S electrolytes, respectively. When CdS nanoparticles are coated on TNCs, the optical absorption is found to be enhanced and band edge is red-shifted towards visible region. The TiO(2)-CdS sample exhibits improved photoelectrochemical (PEC) performance with maximum short circuit current of (J(sc)) 1.04 mA cm(-2). After applying these TiO(2)-CdS electrodes in photovoltaic cells, the photocurrent was found to be enhanced by 2.7 and 32.5 times, as compared with those of bare CdS and TiO(2) nanocorals films electrodes respectively. Also, the power conversion efficiency of TiO(2)-CdS electrodes is 0.72%, which is enhanced by about 16 and 29 times for TiO(2), CdS samples. This journal is © The Royal Society of Chemistry and Owner Societies 2011

Label-free fluorimetric detection of CEA using carbon dots derived from tomato juice.

PubMed

Miao, Hong; Wang, Lan; Zhuo, Yan; Zhou, Zinan; Yang, Xiaoming

2016-12-15

A facile-green strategy to synthesize carbon dots (CDs) with a quantum yield (QY) of nearly 13.9% has been built up, while tomato juice served as the carbon source. Interestingly, not only the precursor of CDs and the whole synthesis procedure were environmental-friendly, but this type of CDs also exhibited multiple advantages including high fluorescent QY, excellent photostability, non-toxicity and satisfactory stability. Significantly, a label-free sensitive assay for detecting carcinoembryonic antigen (CEA) in a continuous and recyclable way has been proposed on the basis of adsorption and desorption of aptamers by the surface of CDs through a competitive mechanism. To be specific, the richness of carboxyl groups of the CDs enabled strong adsorption of ssDNA to the surface of CDs through π-π stacking interactions, resulting in the effective fluorescence quenching by forming CDs-aptamer complexes. The stronger binding affinity between CEA and CEA-aptamer than the π-π stacking interactions has been taken advantage to achieve immediate recovery of the fluorescence of CDs once CEA was introduced. Thereby, quantitative evaluation of CEA concentration in a broad range from 1ngmL(-1) to 0.5ngmL(-1) with the detection limit of 0.3ngmL(-1) was realized in this way. This strategy can be applied in a recyclable way, broadening the sensing application of CDs with biocompatibility. Besides, the CDs were used for cell imaging, potentiating them towards diverse purposes. Copyright © 2016 Elsevier B.V. All rights reserved.

Growth and characterization of CdS buffer layers by CBD and MOCVD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morrone, A.A.; Huang, C.; Li, S.S.

1999-03-01

Thin film CdS has been widely used in thin-film photovoltaic devices. The most efficient Cu(In,&hthinsp;Ga)Se{sub 2} (CIGS) solar cells reported to date utilized a thin CdS buffer layer prepared by a reactive solution growth technique known as chemical bath deposition (CBD). Considerable effort has been directed to better understand the role and find a replacement for the CBD CdS process in CIGS-based solar cells. We reported a low temperature ({approximately}150&hthinsp;{degree}C) Metalorganic Chemical Vapor Deposition (MOCVD) CdS thin film buffer layer process for CIGS absorbers. Many prior studies have reported that CBD CdS contains a mixture of crystal structures. Recent investigationsmore » of CBD CdS thin films by ellipsometry suggested a multilayer structure. In this study we compare CdS thin films prepared by CBD and MOCVD and the effects of annealing. TED and XRD are used to characterize the crystal structure, the film microstructure is studied by HRTEM, and the optical properties are studied by Raman and spectrophotometry. All of these characterization techniques reveal superior crystalline film quality for CdS films grown by MOCVD compared to those grown by CBD. Dual Beam Optical Modulation (DBOM) studies showed that the MOCVD and CBD CdS buffer layer processes have nearly the same effect on CIGS absorbers when combined with a cadmium partial electrolyte aqueous dip. {copyright} {ital 1999 American Institute of Physics.}« less

Analysis of Nursing Clinical Decision Support Requests and Strategic Plan in a Large Academic Health System.

PubMed

Whalen, Kimberly; Bavuso, Karen; Bouyer-Ferullo, Sharon; Goldsmith, Denise; Fairbanks, Amanda; Gesner, Emily; Lagor, Charles; Collins, Sarah

2016-01-01

To understand requests for nursing Clinical Decision Support (CDS) interventions at a large integrated health system undergoing vendor-based EHR implementation. In addition, to establish a process to guide both short-term implementation and long-term strategic goals to meet nursing CDS needs. We conducted an environmental scan to understand current state of nursing CDS over three months. The environmental scan consisted of a literature review and an analysis of CDS requests received from across our health system. We identified existing high priority CDS and paper-based tools used in nursing practice at our health system that guide decision-making. A total of 46 nursing CDS requests were received. Fifty-six percent (n=26) were specific to a clinical specialty; 22 percent (n=10) were focused on facilitating clinical consults in the inpatient setting. "Risk Assessments/Risk Reduction/Promotion of Healthy Habits" (n=23) was the most requested High Priority Category received for nursing CDS. A continuum of types of nursing CDS needs emerged using the Data-Information-Knowledge-Wisdom Conceptual Framework: 1) facilitating data capture, 2) meeting information needs, 3) guiding knowledge-based decision making, and 4) exposing analytics for wisdom-based clinical interpretation by the nurse. Identifying and prioritizing paper-based tools that can be modified into electronic CDS is a challenge. CDS strategy is an evolving process that relies on close collaboration and engagement with clinical sites for short-term implementation and should be incorporated into a long-term strategic plan that can be optimized and achieved overtime. The Data-Information-Knowledge-Wisdom Conceptual Framework in conjunction with the High Priority Categories established may be a useful tool to guide a strategic approach for meeting short-term nursing CDS needs and aligning with the organizational strategic plan.

High Performance Photoluminescent Carbon Dots for In Vitro and In Vivo Bioimaging: Effect of Nitrogen Doping Ratios.

PubMed

Wang, Junqing; Zhang, Pengfei; Huang, Chao; Liu, Gang; Leung, Ken Cham-Fai; Wáng, Yì Xiáng J

2015-07-28

Photoluminescent carbon dots (CDs) have received ever-increasing attention in the application of optical bioimaging because of their low toxicity, tunable fluorescent properties, and ultracompact size. We report for the first time on enhanced photoluminescence (PL) performance influenced by structure effects among the various types of nitrogen doped (N-doped) PL CDs. These CDs were facilely synthesized from condensation carbonization of linear polyethylenic amine (PEA) analogues and citric acid (CA) of different ratios. Detailed structural and property studies demonstrated that either the structures or the molar ratio of PEAs altered the PL properties of the CDs. The content of conjugated π-domains with C═N in the carbon backbone was correlated with their PL Quantum Yield (QY) (up to 69%). The hybridization between the surface/molecule state and the carbon backbone synergistically affected the chemical/physical properties. Also, long-chain polyethylenic amine (PEA) molecule-doped CDs exhibit increasing photostability, but at the expense of PL efficiency, proving that the PL emission of high QY CDs arise not only from the sp(2)/sp(3) carbon core and surface passivation of CDs, but also from the molecular fluorophores integrated in the CDs. In vitro and in vivo bioimaging of these N-doped CDs showed strong photoluminescence signals. Good biocompatibility demonstrates their potential feasibility for bioimaging applications. In addition, the overall size profile of the as-prepared CDs is comparable to the average size of capillary pores in normal living tissues (∼5 nm). Our study provides valuable insights into the effects of the PEA doping ratios on photoluminescence efficiency, biocompatibility, cellular uptake, and optical bioimaging of CDs.

Chemically Deposited CdS Buffer/Kesterite Cu2ZnSnS4 Solar Cells: Relationship between CdS Thickness and Device Performance.

PubMed

Hong, Chang Woo; Shin, Seung Wook; Suryawanshi, Mahesh P; Gang, Myeng Gil; Heo, Jaeyeong; Kim, Jin Hyeok

2017-10-25

Earth-abundant, copper-zinc-tin-sulfide (CZTS), kesterite, is an attractive absorber material for thin-film solar cells (TFSCs). However, the open-circuit voltage deficit (V oc -deficit) resulting from a high recombination rate at the buffer/absorber interface is one of the major challenges that must be overcome to improve the performance of kesterite-based TFSCs. In this paper, we demonstrate the relationship between device parameters and performances for chemically deposited CdS buffer/CZTS-based heterojunction TFSCs as a function of buffer layer thickness, which could change the CdS/CZTS interface conditions such as conduction band or valence band offsets, to gain deeper insight and understanding about the V oc -deficit behavior from a high recombination rate at the CdS buffer/kesterite interface. Experimental results show that device parameters and performances are strongly dependent on the CdS buffer thickness. We postulate two meaningful consequences: (i) Device parameters were improved up to a CdS buffer thickness of 70 nm, whereas they deteriorated at a thicker CdS buffer layer. The V oc -deficit in the solar cells improved up to a CdS buffer thickness of 92 nm and then deteriorated at a thicker CdS buffer layer. (ii) The minimum values of the device parameters were obtained at 70 nm CdS thickness in the CZTS TFSCs. Finally, the highest conversion efficiency of 8.77% (V oc : 494 mV, J sc : 34.54 mA/cm 2 , and FF: 51%) is obtained by applying a 70 nm thick CdS buffer to the Cu 2 ZnSn(S,Se) 4 absorber layer.

Synthesis of CdS nanorods in soft template under gamma-irradiation.

PubMed

Zhao, Bing; Wang, Yanli; Zhang, Haijiao; Jiao, Zheng; Wang, Haobo; Ding, Guoji; Wu, Minghong

2009-02-01

CdS nano material which has a band gap of 2.42 eV at room temperature is a typical II-VII semiconductor having many commercial or potential applications, e.g., light-emitting diodes, solar cell and optoelectronic devices. In this paper, we use a new strategy to synthesize CdS nanorods. CdS nanorods were prepared in soft template under gamma-irradiation though the reaction of cadmium sulphide and thiacetamide (TAA). The formation process and characters of CdS nanorods was investigated in detail by transmission electron microscopy (TEM), electron diffraction (ED) pattern, X-ray powder diffraction (XRD), ultraviolet spectrophotometer (UV) and photoluminescence spectrophotometer (PL). In the experiment we proposed that the irradiation of gamma-ray accelerated the formation of S(2-) under acidic condition (pH = 3) and vinyl acetate (VAc) monomer formed pre-organized nano polymer tubules which were used as both templates and nanoreacters for the growth of CdS nanorods. In this process, we have obtained the CdS polycrystal nanorods with PVAc nano tubules and CdS single-crystal nanorods. The result of X-ray powder diffraction confirms that the crystal type of CdS nanorods is cubic F-43 m (216). The results from transmission electron microscopy and electron diffraction show that the concentrations of reactants and the dose rate of gamma-ray are key to produce appropriate CdS nanorods. Relatively low concentrations (Cd2+: 0.008-0.02 mol/L, Cd2+ : S(2-) = 1 : 2) of reactants and long time (1-2 d) of irradiation in low dose rate (6-14 Gy/min) are propitious to form CdS single-crystal nanorods with small diameter (less than 100 nm) and well length (2-5 microm). UV and PL characterizations show the sample have well optical properties.

Nitrogen-doped carbon dots originating from unripe peach for fluorescent bioimaging and electrocatalytic oxygen reduction reaction.

PubMed

Atchudan, Raji; Edison, Thomas Nesakumar Jebakumar Immanuel; Lee, Yong Rok

2016-11-15

This paper reports the robust hydrothermal synthesis of nitrogen doped carbon dots (N-CDs) using the unripe fruit of Prunus persica (peach) as the carbon precursor and aqueous ammonia as the nitrogen source. The optical properties of synthesized N-CDs were characterized by ultraviolet visible (UV-Vis) and fluorescence spectroscopy techniques. The synthesized N-CDs were emitted blue light when excitated with a portable UV lamp. The materials with the optical properties were characterized further by high resolution transmission electron microscope (HRTEM), X-ray diffraction (XRD), Raman, Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS). The mean size of the N-CDs was approximately 8nm, as calculated from the HRTEM image. The d-spacing of N-CDs, calculated using Bragg law, was approximately 0.21nm, which was consistent with the interlayer distance calculated from the HRTEM image. FT-IR spectroscopy and XPS revealed the presence of the phytoconstituents functionalities of peach fruit over the N-CDs surface and a high level of nitrogen doping on carbon dots (CDs) was confirmed by XPS studies. These results suggest that the unripe fruit extract of peach is an ideal candidate for the preparation of N-CDs. The resulting N-CDs showed excellent optical properties in water. The synthesized N-CDs exhibited a high fluorescence quantum yield and low cytotoxicity, and can be used as fluorescence imaging probes. In addition, the N-CDs were catalytically activite towards the oxygen reduction reaction (ORR). The N-CDs exhibited good catalytic activity in an alkaline medium (0.1M KOH) with a remarkable ORR of approximately 0.72V vs reversible hydrogen electrode (RHE), and O2 reduction follows mainly a 2 electron pathway by being reduced to hydrogen peroxide. The 2-electron reduction pathway is used in industry for H2O2 production. Copyright © 2016 Elsevier Inc. All rights reserved.

Harmful impact on presynaptic glutamate and GABA transport by carbon dots synthesized from sulfur-containing carbohydrate precursor.

PubMed

Borisova, Tatiana; Dekaliuk, Mariia; Pozdnyakova, Natalia; Pastukhov, Artem; Dudarenko, Marina; Borysov, Arsenii; Vari, Sandor G; Demchenko, Alexander P

2017-07-01

Carbon nanoparticles that may be potent air pollutants with adverse effects on human health often contain heteroatoms including sulfur. In order to study in detail their effects on different physiological and biochemical processes, artificially produced carbon dots (CDs) with well-controlled composition that allows fluorescence detection may be of great use. Having been prepared from different types of organic precursors, CDs expose different atoms at their surface suggesting a broad variation of functional groups. Recently, we demonstrated neurotoxic properties of CDs synthesized from the amino acid β-alanine, and it is of importance to analyze whether CDs obtained from different precursors and particularly those exposing sulfur atoms induce similar neurotoxic effects. This study focused on synthesis of CDs from the sulfur-containing precursor thiourea-CDs (TU-CDs) with a size less than 10 nm, their characterization, and neuroactivity assessment. Neuroactive properties of TU-CDs were analyzed based on their effects on the key characteristics of glutamatergic and γ-aminobutyric acid (GABA) neurotransmission in isolated rat brain nerve terminals. It was observed that TU-CDs (0.5-1.0 mg/ml) attenuated the initial velocity of Na + -dependent transporter-mediated uptake and accumulation of L-[ 14 C]glutamate and [ 3 H]GABA by nerve terminals in a dose-dependent manner and increased the ambient level of the neurotransmitters. Starting from the concentration of 0.2 mg/ml, TU-CDs evoked a gradual dose-dependent depolarization of the plasma membrane of nerve terminals measured with the cationic potentiometric dye rhodamine 6G. Within the concentration range of 0.1-0.5 mg/ml, TU-CDs caused an "unphysiological" step-like increase in fluorescence intensity of the рН-sensitive fluorescent dye acridine orange accumulated by synaptic vesicles. Therefore, despite different surface properties and fluorescent features of CDs prepared from different starting materials (thiourea and β-alanine), their principal neurotoxic effects are analogous but displayed at a different level of efficiency. Sulfur-containing TU-CDs exhibit lower effects (by ~30%) on glutamate and GABA transport in the nerve terminals in comparison with sulfur-free β-alanine CDs. Our results suggest considering that an uncontrolled presence of carbon-containing particulate matter in the human environment may pose a toxicity risk for the central nervous system.

Properties of AGN coronae in the NuSTAR era - II. Hybrid plasma

NASA Astrophysics Data System (ADS)

Fabian, A. C.; Lohfink, A.; Belmont, R.; Malzac, J.; Coppi, P.

2017-05-01

The corona, a hot cloud of electrons close to the centre of the accretion disc, produces the hard X-ray power-law continuum commonly seen in luminous active galactic nuclei. The continuum has a high-energy turnover, typically in the range of one to several 100 keV and is suggestive of Comptonization by thermal electrons. We are studying hard X-ray spectra of AGN obtained with NuSTAR after correction for X-ray reflection and under the assumption that coronae are compact, being only a few gravitational radii in size as indicated by reflection and reverberation modelling. Compact coronae raise the possibility that the temperature is limited and indeed controlled by electron-positron pair production, as explored earlier (Paper I). Here, we examine hybrid plasmas in which a mixture of thermal and non-thermal particles is present. Pair production from the non-thermal component reduces the temperature leading to a wider temperature range more consistent with observations.

The 26.3-h orbit and multiwavelength properties of the `redback' millisecond pulsar PSR J1306-40

NASA Astrophysics Data System (ADS)

Linares, Manuel

2018-01-01

We present the discovery of the variable optical and X-ray counterparts to the radio millisecond pulsar (MSP) PSR J1306-40, recently discovered by Keane et al. We find that both the optical and X-ray fluxes are modulated with the same period, which allows us to measure for the first time the orbital period Porb = 1.097 16[6] d. The optical properties are consistent with a main-sequence companion with spectral type G to mid K and, together with the X-ray luminosity (8.8 × 1031 erg s-1 in the 0.5-10 keV band, for a distance of 1.2 kpc), confirm the redback classification of this pulsar. Our results establish the binary nature of PSR J1306-40, which has the longest Porb among all known compact binary MSPs in the Galactic disc. We briefly discuss these findings in the context of irradiation and intrabinary shock emission in compact binary MSPs.

Phase- and shape-controlled hydrothermal synthesis of CdS nanoparticles, and oriented attachment growth of its hierarchical architectures

NASA Astrophysics Data System (ADS)

Cao, Yali; Hu, Pengfei; Jia, Dianzeng

2013-01-01

Hydrothermal strategies were successfully used to control the phases and morphologies of CdS nanocrystals. In the absence of an external direction-controlling process, the hexagonal and cubic phase well-defined leaf- and flower-like CdS nanocrystals were controlled obtained via adjusting the reaction duration or the concentration of surfactant. Oriented attachment growth modes were suggested for the formation of CdS superstructures, which was clarified through the tracing of temporal evolution of CdS nanoparticles. The CdS superstructures were structured by primary building nanoparticles, and held excellent visible emission with a peak in the green regions. This strategy is very helpful for studying the phase and morphology controlled fabrication of sulfides nanocrystals.

Biomimetic synthesis of needle-like fluorescent calcium phosphate/carbon dot hybrid composites for cell labeling and copper ion detection.

PubMed

Guo, Shanshan; Lu, Shousi; Xu, Pingxiang; Ma, Yi; Zhao, Liang; Zhao, Yuming; Gu, Wei; Xue, Ming

2016-05-04

Herein, we report a biomimetic method to synthesize needle-like calcium phosphate (CaP) with dimensions of ∼130 nm length and ∼30 nm width using carbon dots (CDs) and sodium carboxymethylcellulose as dual templates. In addition to acting as the template, the CDs enable the CaP/CDs hybrid composites to emit blue fluorescence under UV excitation. Moreover, the prepared CaP/CDs exhibited a negligible cytotoxicity towards HeLa cells. The potential of these CaP/CDs as a fluorescent probe for cell labeling was tested. In addition, it was demonstrated that the CaP/CDs were capable of selective detection of copper ions in drinking water.

Biosynthesis of CdS nanoparticles in banana peel extract.

PubMed

Zhou, Guang Ju; Li, Shuo Hao; Zhang, Yu Cang; Fu, Yun Zhi

2014-06-01

Cadmium sulfide (CdS) nanoparticles (NPs) were synthesized by using banana peel extract as a convenient, non-toxic, eco-friendly 'green' capping agent. Cadmium nitrate and sodium sulfide are main reagents. A variety of CdS NPs are prepared through changing reaction conditions (banana extracts, the amount of banana peel extract, solution pH, concentration and reactive temperature). The prepared CdS colloid displays strong fluorescence spectrum. X-ray diffraction analysis demonstrates the successful formation of CdS NPs. Fourier transform infra-red (FTIR) spectrogram indicates the involvement of carboxyl, amine and hydroxyl groups in the formation of CdS NPs. Transmission electron microscope (TEM) result reveals that the average size of the NPs is around 1.48 nm.

Unique organogel formation with macroporous materials constructed by the freeze-drying of aqueous cyclodextrin solutions.

PubMed

Marui, Yasuhiro; Kikuzawa, Akira; Kida, Toshiyuki; Akashi, Mitsuru

2010-07-06

Macroporous cyclodextrin materials (MP-alpha-, beta-, and gamma-CDs) were easily fabricated by the freeze-drying of aqueous solutions of alpha-, beta-, and gamma-CDs. These MP-CDs showed the absorption ability toward various organic solvents and oils to give organogels at ambient temperature. The morphological changes of the MP-CD microstructures were observed through the absorption of organic solvents. In particular, the absorption of polar organic solvents with hydrogen-bond forming ability, including 1,4-dioxane and ethanol, by the MP-CDs caused remarkable morphological changes in the microstructures. The absorption of these polar solvents by MP-alpha- and gamma-CDs resulted in the formation of channel-type assemblies of alpha- and gamma-CDs, respectively.

Mn(II)-coordinated Fluorescent Carbon Dots: Preparation and Discrimination of Organic Solvents

NASA Astrophysics Data System (ADS)

Wang, Yuru; Wang, Tianren; Chen, Xi; Xu, Yang; Li, Huanrong

2018-04-01

Herein, we prepared a Mn(II)-coordinated carbon dots (CDs) with fluorescence and MRI (magnetic resonance imaging) bimodal properties by a one-pot solvothermal method and separated via silica column chromatography. The quantum yield of the CDs increased greatly from 2.27% to 6.75% with increase of Mn(II) doping, meanwhile the CDs exhibited a higher MR activity (7.28 mM-1s-1) than that of commercial Gd-DTPA (4.63 mM-1s-1). In addition, white light emitting CDs were obtained by mixing the different types of CDs. Notably, these CDs exhibited different fluorescence emissions in different organic solvents and could be used to discriminate organic solvents based on the polarity and protonation of the solvents.

Templated electrochemical deposition of zirconia thin films on "recordable CDs.".

PubMed

Yu, Hua-Zhong; Rowe, Aaron W; Waugh, Damien M

2002-11-15

In this paper, we describe a practical method of using gold films constructed from recordable compact disks (CD-Rs) as simple, inexpensive, and micropatterned conductive substrates for the fabrication of inorganic material microstructures. Extending from their application for the fabrication of self-assembled monolayers (SAMs) reported recently, bare and SAM-modified CD-R gold substrates have been used for template-directed electrodeposition of zirconia (ZrO2) thin films (i.e., the controlled formation of zirconia thin films on the different areas of the prefabricated, micrometer mountain-valley CD-R gold substrate surfaces). The present results demonstrate that the variation of the functional groups of the selected SAMs combined with electrodynamic control can be very successful to "customize" the formation and microstructure of functional inorganic thin films, which hold promise for modern technological applications.

Surface morphology changes to tungsten under exposure to He ions from an electron cyclotron resonance plasma source

NASA Astrophysics Data System (ADS)

Donovan, David; Buchenauer, Dean; Whaley, Josh; Friddle, Raymond; Wright, Graham

2014-10-01

Exposure of tungsten to low energy (<100 eV) helium plasmas at temperatures between 900-1900 K in both laboratory experiments and tokamaks has been shown to cause severe nanoscale modification of the near surface resulting the growth of tungsten tendrils. We are exploring the potential for using a compact ECR plasma in situ with scanning tunneling microscopy (STM) to investigate the early stages of helium induced tungsten migration. Here we report on characterization of the plasma source for helium plasmas with a desired ion flux of ~1 × 1019 ions m-2 s-1 and the surface morphology changes seen on the exposed tungsten surfaces. Exposures of polished tungsten discs have been performed and characterized using SEM, AFM, and FIB cross section imaging. Bubbles have been seen on the exposed tungsten surface and in sub-surface cross sections growing to up to 150 nm in diameter. Comparisons are made between exposures of warm rolled Plansee tungsten discs and ALMT ITER grade tungsten samples. Work supported by US DOE Contract DE-AC04-94AL85000 and the PSI Science Center.

Unveiling the radio counterparts of two binary AGN candidates: J1108+0659 and J1131-0204

NASA Astrophysics Data System (ADS)

Bondi, M.; Pérez-Torres, M. A.; Piconcelli, E.; Fu, H.

2016-04-01

The sources SDSS J113126.08-020459.2 and SDSS J110851.04+065901.4 are two double-peaked [O III] emitting active galactic nuclei (AGNs), identified as candidate binary AGNs by optical and near infrared (NIR) observations. We observed the two sources with high resolution Very Long Baseline Interferometry (VLBI) using the European VLBI Network at 5 GHz, reduced VLA observations at three frequencies available for one of the sources, and used archival HST observations. For the source SDSS J113126.08-020459.2, the VLBI observations detected only one single compact component associated with the eastern NIR nucleus. In SDSS J110851.04+065901.4, the VLBI observations did not detect any compact components, but the VLA observations allowed us to identify a possible compact core in the region of the north-western optical/NIR nucleus. In this source we find kpc-scale extended radio emission that is spatially coincident to the ultraviolet continuum and to the extended emission narrow line region. The UV continuum is significantly obscured since the amount of extended radio emission yields a star formation rate of about 110 M⊙ yr-1, which is an order of magnitude larger than implied by the observed ultraviolet emission. Our analysis confirms the presence of only one AGN in the two candidate binary AGNs. FITS files of the reduced images are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/588/A102

Multi-school collaboration to develop and test nutrition computer modules for pediatric residents.

PubMed

Roche, Patricia L; Ciccarelli, Mary R; Gupta, Sandeep K; Hayes, Barbara M; Molleston, Jean P

2007-09-01

The provision of essential nutrition-related content in US medical education has been deficient, despite efforts of the federal government and multiple professional organizations. Novel and efficient approaches are needed. A multi-department project was developed to create and pilot a computer-based compact disc instructional program covering the nutrition topics of oral rehydration therapy, calcium, and vitamins. Funded by an internal medical school grant, the content of the modules was written by Department of Pediatrics faculty. The modules were built by School of Informatics faculty and students, and were tested on a convenience sampling of 38 pediatric residents in a randomized controlled trial performed by a registered dietitian/School of Health and Rehabilitation Sciences Master's degree candidate. The modules were reviewed for content by the pediatric faculty principal investigator and the registered dietitian/School of Health and Rehabilitation Sciences graduate student. Residents completed a pretest of nutrition knowledge and attitude toward nutrition and Web-based instruction. Half the group was given three programs (oral rehydration therapy, calcium, and vitamins) on compact disc for study over 6 weeks. Both study and control groups completed a posttest. Pre- and postintervention objective test results in study vs control groups and attitudinal survey results before and after intervention in the study group were compared. The experimental group demonstrated significantly better posttrial objective test performance compared to the control group (P=0.0005). The study group tended toward improvement, whereas the control group performance declined substantially between pre- and posttests. Study group resident attitudes toward computer-based instruction improved. Use of these computer modules prompted almost half of the residents in the study group to independently pursue relevant nutrition-related information. This inexpensive, collaborative, multi-department effort to design a computer-based nutrition curriculum positively impacted both resident knowledge and attitudes.

Single Mode Fiber Optic Transceiver Using Short Wavelength Active Devices In Long Wavelength Fiber

NASA Astrophysics Data System (ADS)

Gillham, Frederick J.; Campbell, Daniel R.; Corke, Michael; Stowe, David W.

1990-01-01

Presently, single mode optical fiber technology is being utilized in systems to supply telephone service to the subscriber. However, in an attempt to be competitive with copper based systems, there are many development programs underway to determine the most cost effective solution while still providing a service that will either satisfy or be upgradeable to satisfy the demands of the consumer for the next 10 to 20 years. One such approach is to combine low cost laser transmitters and silicon receivers, which have been developed for the "compact disc" industry, with fiber that operates in the single mode regime at 1300 nm. In this paper, an optical transceiver will be presented, consisting of a compact disc laser, a silicon detector and a single mode coupler at 1300 nm. A possible system layout is presented which operates at 780 nm bi-directionally for POTS and upgradeable to 1300 nm for video services. There are several important design criteria that have to be considered in the development of such a system which will be addressed. These include: 1. Optimization of coupled power from laser to fiber while maintaining stable launched conditions over a wide range of environmental conditions. 2. Consideration of the multimode operation of the 1300 nm single mode fiber while operating in the 780 nm wavelength region. 3. Development of a low cost pseudo-wavelength division multiplexer for 1300 nm single mode/780 nm multimode operation and a low cost dual mode 50/50, 780 nm splitter using 1300 nm fiber. Details will be given of the design criteria and solution in terms of optimized design. Results of the performance of several prototype devices will be given with indications of the merits of this approach and where further development effort should be applied.

Impact of the Cornea Donor Study (CDS) on Acceptance of Corneas from Older Donors

PubMed Central

Sugar, Alan; Montoya, Monty M.; Beck, Roy; Cowden, John W.; Dontchev, Mariya; Gal, Robin L.; Kollman, Craig; Malling, Jackie; Mannis, Mark J.; Tennant, Bradley

2014-01-01

Purpose Evaluate retrospectively whether findings from the Cornea Donor Study (CDS) led to changes in the transplantation of corneas from older donors. Methods United States eye banks provided complete data on donor age and placement (domestic or international) for 86,273 corneas from 1998 to 2009. The data were analyzed by 3 time periods: preceding CDS (1998–1999), during CDS (2000–2007) and after publication of CDS 5 year results (2008–2009), and separately for corneas placed within vs. outside the United States. Results For corneal tissues transplanted in the United States, the percentage of donors ≥66 years old increased from 19% before CDS to 21% during CDS and 25% after CDS (p<0.001). Corresponding median (25th-75th percentile) donor ages were 53 (39–63), 54 (41–64) and 57 (46–66), respectively (p<0.001). The opposite trend was observed for corneas distributed outside the United States with the percentage of donors ≥66 years old decreasing from 56% to 42% to 34%, respectively. Donor age trends over time varied by eye bank. Conclusions There was a modest overall increase in the donor age of corneas transplanted in the United States from 1998 to 2009, but the retrospective nature of the study limits our ability to attribute this change to the CDS. The modest increases in the donor age of corneas transplanted is a positive finding, but wider acceptance of older corneal donor tissue should be encouraged based on the five-year evidence generated by the CDS. PMID:22262218

Biological and catalytic applications of green synthesized fluorescent N-doped carbon dots using Hylocereus undatus.

PubMed

Arul, Velusamy; Edison, Thomas Nesakumar Jebakumar Immanuel; Lee, Yong Rok; Sethuraman, Mathur Gopalakrishnan

2017-03-01

In this work, a simple hydrothermal route for the synthesis of fluorescent nitrogen doped carbon dots (N-CDs) is reported. The Hylocereus undatus (H. undatus) extract and aqueous ammonia are used as carbon and nitrogen source, respectively. The optical properties of synthesized N-CDs are analyzed using UV-Visible (UV-Vis) and fluorescence spectroscopy. The surface morphology, elemental composition, crystallinity and functional groups present in the N-CDs are examined using high resolution transmission electron microscopy (HR-TEM) with energy dispersive spectroscopy (EDS), selected area electron diffraction (SAED), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy, respectively. The synthesized N-CDs emit strong blue fluorescence at 400nm under the excitation of 320nm. Further, the excitation dependent emission properties are also observed from the fluorescence of synthesized N-CDs. The HR-TEM results reveal that synthesized N-CDs are in spherical shape with average diameter of 2.5nm. The XRD pattern exhibits, the graphitic nature of synthesized N-CDs. The doping of nitrogen is confirmed from the EDS and FT-IR studies. The cytotoxicity and biocompatibility of N-CDs are evaluated through MTT assay on L-929 (Lymphoblastoid-929) and MCF-7 (Michigan Cancer Foundation-7) cells. The results indicate that the fluorescent N-CDs show less cytotoxicity and good biocompatibility on both L-929 and MCF-7 cells. Moreover, the N-CDs show excellent catalytic activity towards the reduction of methylene blue by sodium borohydride. Copyright © 2017 Elsevier B.V. All rights reserved.

Structural Dynamics of Carbon Dots in Water and N, N-Dimethylformamide Probed by All-Atom Molecular Dynamics Simulations.

PubMed

Paloncýová, Markéta; Langer, Michal; Otyepka, Michal

2018-04-10

Carbon dots (CDs), one of the youngest members of the carbon nanostructure family, are now widely experimentally studied for their tunable fluorescence properties, bleaching resistance, and biocompatibility. Their interaction with biomolecular systems has also been explored experimentally. However, many atomistic details still remain unresolved. Molecular dynamics (MD) simulations enabling atomistic and femtosecond resolutions simultaneously are a well-established tool of computational chemistry which can provide useful insights into investigated systems. Here we present a full procedure for performing MD simulations of CDs. We developed a builder for generating CDs of a desired size and with various oxygen-containing surface functional groups. Further, we analyzed the behavior of various CDs differing in size, surface functional groups, and degrees of functionalization by MD simulations. These simulations showed that surface functionalized CDs are stable in a water environment through the formation of an extensive hydrogen bonding network. We also analyzed the internal dynamics of individual layers of CDs and evaluated the role of surface functional groups on CD stability. We observed that carboxyl groups interconnected the neighboring layers and decreased the rate of internal rotations. Further, we monitored changes in the CD shape caused by an excess of charged carboxyl groups or carbonyl groups. In addition to simulations in water, we analyzed the behavior of CDs in the organic solvent DMF, which decreased the stability of pure CDs but increased the level of interlayer hydrogen bonding. We believe that the developed protocol, builder, and parameters will facilitate future studies addressing various aspects of structural features of CDs and nanocomposites containing CDs.

Simple and green synthesis of protein-conjugated CdS nanoparticles and spectroscopic study on the interaction between CdS and zein

NASA Astrophysics Data System (ADS)

Qin, Dezhi; Zhang, Li; Du, Xian; Wang, Yabo; Zhang, Qiuxia

2016-09-01

The present study demonstrates the role of zein molecules in synthesizing CdS nanoassemblies through protein-directed, green synthetic approach. Zein molecules can as capping ligand and stabilizing agent to regulate the nucleation and growth of CdS nanocrystals, and the obtained products are organic-inorganic nanocomposites. The analysis of surface charge and conductivity indicates that strong electrostatic force restricts mobility of ions, which creates a local supersaturation surrounding the binding sites of zein and reduces the activated energy of nucleation. The interaction between Cd2+/CdS and zein molecules was systematically investigated through spectroscopy techniques. Fourier transform infrared (FT-IR) spectra were used to envisage the binding of the functional groups of zein with the surface of CdS nanoparticles. Ultraviolet visible (UV-Vis) and photoluminescence (PL) spectra results show that Cd2+/CdS might interact with the aromatic amino acids of protein molecules and change its chemical microenvironment. The quantum-confined effect of nanocrystals is confirmed by optical absorption spectrum due to the small size (3-5 nm) of CdS particles. The data of circular dichroism (CD) spectra indicate that the formation of CdS nanocrystals could lead to the conformational change of zein molecules. Moreover, the possible mechanism of CdS nanocrystals growth in zein solution was also discussed. The weak interactions such as Van der Waals, hydrophobic forces and hydrogen bonds in zein molecules should play a crucial factor in the self-assembly of small nanoparticles.

A qualitative study of the activities performed by people involved in clinical decision support: recommended practices for success

PubMed Central

Wright, Adam; Ash, Joan S; Erickson, Jessica L; Wasserman, Joe; Bunce, Arwen; Stanescu, Ana; St Hilaire, Daniel; Panzenhagen, Morgan; Gebhardt, Eric; McMullen, Carmit; Middleton, Blackford; Sittig, Dean F

2014-01-01

Objective To describe the activities performed by people involved in clinical decision support (CDS) at leading sites. Materials and methods We conducted ethnographic observations at seven diverse sites with a history of excellence in CDS using the Rapid Assessment Process and analyzed the data using a series of card sorts, informed by Linstone's Multiple Perspectives Model. Results We identified 18 activities and grouped them into four areas. Area 1: Fostering relationships across the organization, with activities (a) training and support, (b) visibility/presence on the floor, (c) liaising between people, (d) administration and leadership, (e) project management, (f) cheerleading/buy-in/sponsorship, (g) preparing for CDS implementation. Area 2: Assembling the system with activities (a) providing technical support, (b) CDS content development, (c) purchasing products from vendors (d) knowledge management, (e) system integration. Area 3: Using CDS to achieve the organization's goals with activities (a) reporting, (b) requirements-gathering/specifications, (c) monitoring CDS, (d) linking CDS to goals, (e) managing data. Area 4: Participation in external policy and standards activities (this area consists of only a single activity). We also identified a set of recommendations associated with these 18 activities. Discussion All 18 activities we identified were performed at all sites, although the way they were organized into roles differed substantially. We consider these activities critical to the success of a CDS program. Conclusions A series of activities are performed by sites strong in CDS, and sites adopting CDS should ensure they incorporate these activities into their efforts. PMID:23999670

The GUIDES checklist: development of a tool to improve the successful use of guideline-based computerised clinical decision support.

PubMed

Van de Velde, Stijn; Kunnamo, Ilkka; Roshanov, Pavel; Kortteisto, Tiina; Aertgeerts, Bert; Vandvik, Per Olav; Flottorp, Signe

2018-06-25

Computerised decision support (CDS) based on trustworthy clinical guidelines is a key component of a learning healthcare system. Research shows that the effectiveness of CDS is mixed. Multifaceted context, system, recommendation and implementation factors may potentially affect the success of CDS interventions. This paper describes the development of a checklist that is intended to support professionals to implement CDS successfully. We developed the checklist through an iterative process that involved a systematic review of evidence and frameworks, a synthesis of the success factors identified in the review, feedback from an international expert panel that evaluated the checklist in relation to a list of desirable framework attributes, consultations with patients and healthcare consumers and pilot testing of the checklist. We screened 5347 papers and selected 71 papers with relevant information on success factors for guideline-based CDS. From the selected papers, we developed a 16-factor checklist that is divided in four domains, i.e. the CDS context, content, system and implementation domains. The panel of experts evaluated the checklist positively as an instrument that could support people implementing guideline-based CDS across a wide range of settings globally. Patients and healthcare consumers identified guideline-based CDS as an important quality improvement intervention and perceived the GUIDES checklist as a suitable and useful strategy. The GUIDES checklist can support professionals in considering the factors that affect the success of CDS interventions. It may facilitate a deeper and more accurate understanding of the factors shaping CDS effectiveness. Relying on a structured approach may prevent that important factors are missed.

Facile and eco-friendly synthesis of green fluorescent carbon nanodots for applications in bioimaging, patterning and staining.

PubMed

Shi, Lihong; Li, Yanyan; Li, Xiaofeng; Wen, Xiangping; Zhang, Guomei; Yang, Jun; Dong, Chuan; Shuang, Shaomin

2015-04-28

We report a facile and eco-friendly strategy for the fabrication of green fluorescent carbon nanodots (CDs), and demonstrate their applications for bio-imaging, patterning, and staining. A one-pot hydrothermal method using various plant petals yields bright green-emitting CDs, providing an easy way for the production of green fluorescent CDs without the need for a tedious synthetic methodology or the use of toxic/expensive solvents and starting materials. The as-prepared CDs show small size distribution and excellent dispersibility. Their strong green fluorescence is observed when the excitation wavelength is between 430 nm and 490 nm. Moreover, they exhibit high tolerance to various external conditions, such as pH values, external cations, and continuous excitation. Due to minimum toxicity as well as good photoluminescence properties, these CDs can be applied to in vitro and in vivo imaging, patterning, and staining. According to confocal fluorescence imaging of human uterine cervical squamous cell carcinoma cells, CDs penetrate into the cell and enter the cytoplasm and the nucleus. More strikingly, carp is directly fed with CDs for in vivo imaging and shows bright green fluorescence at an excitation wavelength of 470 nm. In addition, the obtained CDs are used as fluorescent inks for drawing luminescence patterns. Finally, we also apply the CDs as a fluorescent dye. Interestingly, the absorbent filter paper with staining emits dramatic fluorescence under 470 nm excitation.

Rapid solid-phase microwave synthesis of highly photoluminescent nitrogen-doped carbon dots for Fe3+ detection and cellular bioimaging

NASA Astrophysics Data System (ADS)

He, Guili; Xu, Minghan; Shu, Mengjun; Li, Xiaolin; Yang, Zhi; Zhang, Liling; Su, Yanjie; Hu, Nantao; Zhang, Yafei

2016-09-01

Recently, carbon dots (CDs) have been playing an increasingly important role in industrial production and biomedical field because of their excellent properties. As such, finding an efficient method to quickly synthesize a large scale of relatively high purity CDs is of great interest. Herein, a facile and novel microwave method has been applied to prepare nitrogen doped CDs (N-doped CDs) within 8 min using L-glutamic acid as the sole reaction precursor in the solid phase condition. The as-prepared N-doped CDs with an average size of 1.64 nm are well dispersed in aqueous solution. The photoluminescence of N-doped CDs is pH-sensitive and excitation-dependent. The N-doped CDs show a strong blue fluorescence with relatively high fluorescent quantum yield of 41.2%, which remains stable even under high ionic strength. Since the surface is rich in oxygen-containing functional groups, N-doped CDs can be applied to selectively detect Fe3+ with the limit of detection of 10-5 M. In addition, they are also used for cellular bioimaging because of their high fluorescent intensity and nearly zero cytotoxicity. The solid-phase microwave method seems to be an effective strategy to rapidly obtain high quality N-doped CDs and expands their applications in ion detection and cellular bioimaging.

Facile green synthesis of fluorescent N-doped carbon dots from Actinidia deliciosa and their catalytic activity and cytotoxicity applications

NASA Astrophysics Data System (ADS)

Arul, Velusamy; Sethuraman, Mathur Gopalakrishnan

2018-04-01

Green synthesis of fluorescent nitrogen doped carbon dots (N-CDs) using Actinidia deliciosa (A. deliciosa) fruit extract as a carbon precursor and aqueous ammonia as a nitrogen dopant is reported here. The synthesized N-CDs were characterized by high resolution transmission electron microscopy (HR-TEM), energy dispersive spectroscopy (EDS), selected area electron diffraction (SAED), UV-Visible spectroscopy (UV-Vis), fluorescence spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The average size of the N-CDs was approximately 3.59 nm and the calculated inter layer distance was found to be 0.21 nm. Raman spectroscopy and SAED pattern revealed the graphitic nature of the synthesized N-CDs. The N-CDs were found to emit intense blue color at 405 nm under the excitation of 315 nm. The doping of nitrogen over the surface of the N-CDs was confirmed by EDS, FT-IR and XPS studies. The synthesized N-CDs were found to exhibit excellent catalytic activity in the reduction of Rhodamine-B using sodium borohydrate. The MTT assay was used to evaluate the cytotoxicity and biocompatibility of N-CDs towards L-929 and MCF-7 cells. From the results obtained, it was found that the N-CDs exhibit low cytotoxicity and superior biocompatibility on both L-929 and MCF-7 cells.

Development of CdS Nanostructures by Thermal Decomposition of Aminocaproic Acid-Mixed Cd-Thiourea Complex Precursor: Structural, Optical and Photocatalytic Characterization.

PubMed

Patel, Jayesh D; Mighri, Frej; Ajji, Abdellah; Chaudhuri, Tapas K

2015-04-01

The present work deals with two different CdS nanostructures produced via hydrothermal and solvothermal decompositions of aminocaproic acid (ACA)-mixed Cd-thiourea complex precursor at 175 °C. Both nanostructures were extensively characterized for their structural, morphological and optical properties. The powder X-ray diffraction characterization showed that the two CdS nanostructures present a wurtzite morphology. Scanning electron microscopy and energy-dispersive X-ray characterizations revealed that the hydrothermal decomposition produced well-shaped CdS flowers composed of six dendritic petals, and the solvothermal decomposition produced CdS microspheres with close stoichiometric chemical composition. The UV-vis absorption and photoluminescence spectra of CdS dendritic flowers and microsphere nanostructures showed that both nanostructures present a broad absorption between 200 and 700 nm and exhibit strong green emissions at 576 and 520 nm upon excitations at 290 nm and 260 nm, respectively. The transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) characterizations confirmed that CdS microspheres were mesoporous and were composed of small nanocrystals. A possible growth mechanism in the formation of the CdS nanostructures was proposed based on morphology evolution as a function of the reaction time. Furthermore, the as-synthesized CdS nanostructures were found to exhibit highly efficient photocatalytic activities for the degradation of methyl orange (MeO) and rhodamine B (RhB) dyes.

The excitonic photoluminescence mechanism and lasing action in band-gap-tunable CdS(1-x)Se(x) nanostructures.

PubMed

Dai, Jun; Zhou, Pengxia; Lu, Junfeng; Zheng, Hongge; Guo, Jiyuan; Wang, Fang; Gu, Ning; Xu, Chunxiang

2016-01-14

Bandgap tunable semiconductor materials have wide application in integrated-optoelectronic and communication devices. The CdS1-xSex ternary semiconductor materials covering green-red bands have been reported previously, but their basic band-gap and optical properties crucial to the performance of the CdS1-xSex-based optoelectronic devices have not been deeply understood. In this paper, we theoretically simulated and discussed the feasibility of bandgap-tunable CdS1-xSex nanomaterials for designing wavelength tunable microlasers. Then we fabricated the CdS1-xSex nanobelts with their band gap ranging from 2.4 to 1.74 eV by adjusting the composition ratio x in the vapor-phase-transport growth process. The temperature-dependent photoluminescence and exciton-related optical constants of the CdS1-xSex nanobelts were carefully demonstrated. Finally, the wavelength-tunable Fabry-Perot lasing in CdS1-xSex nanobelts was obtained, and the Fabry-Perot lasing mechanism was numerically simulated by the FDTD method. The systematic results on the mechanism of the tunable band gap, exciton properties and lasing of the CdS1-xSex nanostructure help us deeply understand the intrinsic optical properties of this material, and will build a strong foundation for future application of green-red wavelength-tunable CdS1-xSex microlasers.

Carbon dots as fluorescent probes for "off-on" detection of Cu2+ and L-cysteine in aqueous solution.

PubMed

Zong, Jie; Yang, Xiaoling; Trinchi, Adrian; Hardin, Simon; Cole, Ivan; Zhu, Yihua; Li, Chunzhong; Muster, Tim; Wei, Gang

2014-01-15

Copper ion (Cu(2+)) and L-cysteine (L-Cys) detection is critically important since an abnormal level of Cu(2+) or L-Cys is an indicator for many diseases. In this paper, we demonstrate an "off-on" approach for highly sensitive and selective detection of Cu(2+) and L-Cys using carbon dots (CDs) as fluorescent probes. CDs were prepared by using mesoporous silica (MS) spheres as nanoreactors. The binding ability of CDs towards metal ions was examined by comparing the fluorescence intensities of CDs before and after the addition of the metal ions. The addition of Cu(2+) cations leads to their absorption on the surface of CDs and the significant fluorescence quench of CDs (turn-off). The resulting in CDs-Cu(2+) system was found to be sensitive to L-Cys. The addition of L-Cys not only serves to shelter the CDs effectively from being quenched, but also to reverse the quenching and restore the fluorescence (turn-on) due to its ability to remove Cu(2+) from the surface of CDs. This method is facile, rapid, low cost, and environment-friendly. A detection limit as low as 2.3×10(-8) M for Cu(2+) and 3.4×10(-10) M for L-Cys is obtained, which is promising for biological applications. © 2013 Elsevier B.V. All rights reserved.

75 FR 11589 - Order Extending Temporary Exemptions Under the Securities Exchange Act of 1934 in Connection with...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-11

... make payments under a CDS contract is triggered by a default or other credit event as to such entity or... CDS clearing by ICE Trust. We recognize, however, that there could be legal uncertainty in the event..., and the access to clearing services by independent CDS exchanges or CDS trading platforms.\\15\\ \\15...

Facile synthesis of S, N co-doped carbon dots and investigation of their photoluminescence properties.

PubMed

Zhang, Yue; He, Junhui

2015-08-21

A facile one-pot approach to prepare photoluminescent carbon dots (CDs) was developed through hydrothermal treatment of cysteine and citric acid. The obtained CDs show stable and bright blue emission with a quantum yield of 54% and an average lifetime of 11.61 ns. Moreover, the two-photon induced upconversion fluorescence of the CDs was observed and demonstrated. Interestingly, both down and up conversion fluorescence of the CDs show excitation-independent emission, which is quite different from most of the previously reported CDs. Ultrafast spectroscopy was also employed here to study the photoluminescence (PL) properties of the CDs. After characterization using various spectroscopic techniques, a unique PL mechanism for the as-prepared CDs' fluorescence was proposed accordingly. In addition, the influence of various metal ions on the CD fluorescence was examined and no quenching phenomena were observed. Meanwhile, gold nanoparticles (Au NPs) were found to be good quenchers of CD fluorescence and their quenching behavior was fitted to the Stern-Volmer equation. This provides new opportunities for fluorescence sensor designs and light energy conversion applications. Finally, the as-prepared CDs were inkjet-printed to form a desirable pattern, which is useful for fluorescent patterns, and anti-counterfeiting labeling.

Fabrication of luminescent CdS nanoparticles on short-peptide-based hydrogel nanofibers: tuning of optoelectronic properties.

PubMed

Palui, Goutam; Nanda, Jayanta; Ray, Sudipta; Banerjee, Arindam

2009-07-13

The pH-induced self-assembly of three synthetic tripeptides in water medium is used to immobilize luminescent CdS nanoparticles. These peptides form a nanofibrillar network structure upon gelation in aqueous medium at basic pH values (pH 11.0-13.0), and the fabrication of CdS nanoparticles on the gel nanofiber confers the luminescent property to these gels. Atomic force microscopy, field-emission scanning electron microscopy, and high-resolution transmission electron microscopy clearly reveal the presence of CdS nanoparticles in a well-defined array on the gel nanofibers. This is a convenient way to make organic nanofiber-inorganic nanoparticle hybrid nanocomposite systems. The size of the CdS nanoparticles remains almost same before and after deposition on the gel nanofiber. Photoluminescence (PL) measurement of the CdS nanoparticles upon deposition on the gel nanofibers shows a significant blue shift in the emission spectrum of the nanoparticles, and there is a considerable change in the PL gap energy of the CdS nanoparticles after immobilization on different gel nanofibrils. This finding suggests that the optoelectronic properties of CdS nanoparticles can be tuned upon deposition on gel nanofibers without changing the size of the nanoparticles.

The Influence of Child-Directed Speech on Word Learning and Comprehension.

PubMed

Foursha-Stevenson, Cassandra; Schembri, Taylor; Nicoladis, Elena; Eriksen, Cody

2017-04-01

This paper describes an investigation into the function of child-directed speech (CDS) across development. In the first experiment, 10-21-month-olds were presented with familiar words in CDS and trained on novel words in CDS or adult-directed speech (ADS). All children preferred the matching display for familiar words. However, only older toddlers in the CDS condition preferred the matching display for novel words. In Experiment 2, children 3-6 years of age were presented with a sentence comprehension task in CDS or ADS. Older children performed better overall than younger children with 5- and 6-year-olds performing above chance regardless of speech condition, while 3- and 4-year-olds only performed above chance when the sentences were presented in CDS. These findings provide support for the theory that CDS is most effective at the beginning of acquisition for particular constructions (e.g. vocabulary acquisition, syntactic comprehension) rather than at a particular age or for a particular task.

Fluorescent chemosensor for pyridine based on N-doped carbon dots.

PubMed

Campos, B B; Abellán, C; Zougagh, M; Jimenez-Jimenez, J; Rodríguez-Castellón, E; Esteves da Silva, J C G; Ríos, A; Algarra, M

2015-11-15

Fluorescent carbon dots (CDs) and its nitrogen doped (N-CDs) nanoparticles have been synthesized from lactose as precursor using a bottom-up hydrothermal methodology. The synthesized nanoparticles have been characterized by elemental analysis, FTIR, Raman, TEM, DLS, XPS, and steady-state and life-time fluorescence. The synthesized carbon nanoparticles, CDs and N-CDs, have a size at about 7.7±2.4 and 50±15nm, respectively, and quantum yields of 8% (CDs) and 11% (N-CDs). These techniques demonstrated the effectiveness of the synthesis procedure and the functionalization of the CDs surface with amine and amide groups in the presence of NH3 in aqueous media. The effect of excitation wavelength and pH on the luminescent properties was studied. Under the optimal conditions, the nitrogen doped nanoparticles can be used as pyridine sensor in aqueous media because they show an enhancement of its fluorescence with a good linear relationship. The analytical method is simple, reproducible and very sensitive for pyridine determination. Copyright © 2015 Elsevier Inc. All rights reserved.

Distribution of different surface modified carbon dots in pumpkin seedlings.

PubMed

Qian, Kun; Guo, Huiyuan; Chen, Guangcai; Ma, Chuanxin; Xing, Baoshan

2018-05-22

The distribution of surface modified carbon dots (CDs) in the pumpkin seedlings was studied by visualization techniques and their potential phytotoxicity was investigated at both the physiological and biochemical levels. The average size of carbon dots was approximately 4 nm. The fluorescent peaks of bared CDs, CD-PEI and CD-PAA were between 420 nm and 500 nm, indicating CDs could emit blue and green fluorescence. Fluorescent images showed that all three types of CDs could accumulate in the pumpkin roots and translocate to the shoots, although the distribution pattern of each CDs was obviously different. At the biochemical level, the elevated antioxidant enzymes in pumpkin roots suggest that all the CDs could potentially trigger the antioxidant defense systems in pumpkin seedlings. Additionally, such alteration was greater in the roots than in the shoots. Our study represents a new perspective on CD visualization in plant tissues and provide useful information for the potential toxicity of different types of CDs to terrestrial plants, which is of importance to agricultural application.

Design Recommendations for Pharmacogenomics Clinical Decision Support Systems

PubMed Central

Khelifi, Maher; Tarczy-Hornoch, Peter; Devine, Emily B.; Pratt, Wanda

2017-01-01

The use of pharmacogenomics (PGx) in clinical practice still faces challenges to fully adopt genetic information in targeting drug therapy. To incorporate genetics into clinical practice, many support the use of Pharmacogenomics Clinical Decision Support Systems (PGx-CDS) for medication prescriptions. This support was fueled by new guidelines to incorporate genetics for optimizing drug dosage and reducing adverse events. In addition, the complexity of PGx led to exploring CDS outside the paradigm of the basic CDS tools embedded in commercial electronic health records. Therefore, designing the right CDS is key to unleashing the full potential of pharmacogenomics and making it a part of clinicians’ daily workflow. In this work, we 1) identify challenges and barriers of the implementation of PGx-CDS in clinical settings, 2) develop a new design approach to CDS with functional characteristics that can improve the adoption of pharmacogenomics guidelines and thus patient safety, and 3) create design guidelines and recommendations for such PGx-CDS tools. PMID:28815136

Enhanced photo response of mesoporous nanostructured CdS thin film via electrospray aerosol deposition technique

NASA Astrophysics Data System (ADS)

Logu, T.; Soundarrajan, P.; Sankarasubramanian, K.; Sethuraman, K.

2018-04-01

In this work, a high crystalline and mesoporous nanostructured cadmium sulfide (CdS) thin film was successfully grown on the FTO substrates using facile Electrospray Aerosol Deposition (ESAD) technique. The structural, optical, morphological and electrical properties of CdS thin film have been systematically examined. CdS thin film exhibits the hexagonal wurtzite crystal structure with polycrystalline nature. The optical band gap energy of the prepared film was estimated from the Tauc plot and is 2.43 eV. The SEM and AFM images show that the well-interconnected CdS nanoparticles gives mesoporous like morphology. The fine aerosol generated from the ESAD process induces the alteration in the surface morphological structure of deposited CdS film that consequences in enhanced electrical and photo-physical properties. The photoconductivity of the sample has been studied which demonstrates significant photo current. The present study predicts that mesoporous nanostructured CdS thin film would be given a special interest for optoelectronic applications.

Arrays of Ultrathin CdS Nanoflakes with High-Energy Surface for Efficient Gas Detection.

PubMed

Liu, Xiao-Hua; Yin, Peng-Fei; Kulinich, Sergei A; Zhou, Yu-Zhu; Mao, Jing; Ling, Tao; Du, Xi-Wen

2017-01-11

It is fascinating and challenging to endow conventional materials with unprecedented properties. For instance, cadmium sulfide (CdS) is an important semiconductor with excellent light response; however, its potential in gas-sensing was underestimated owing to relatively low chemical activity and poor electrical conductivity. Herein, we demonstrate that an ideal architecture, ultrathin nanoflake arrays (NFAs), can improve significantly gas-sensing properties of CdS material. The CdS NFAs are grown directly on the interdigitated electrode to expose large surface area. Their thickness is reduced below the double Debye length of CdS, permitting to achieve a full depletion of carriers. Particularly, the prepared CdS nanoflakes are enclosed with high-energy {0001} facets exposed, which provides more active sites for gas adsorption. Moreover, the NFAs exhibit the light-trapping effect, which further enhances their gas sensitivity. As a result, the as-prepared CdS NFAs demonstrate excellent gas-sensing and light-response properties, thus being capable of dual gas and light detection.

Two Closely Related Genes of Arabidopsis Encode Plastidial Cytidinediphosphate Diacylglycerol Synthases Essential for Photoautotrophic Growth1[C

PubMed Central

Haselier, André; Akbari, Hana; Weth, Agnes; Baumgartner, Werner; Frentzen, Margrit

2010-01-01

Cytidinediphosphate diacylglycerol synthase (CDS) catalyzes the formation of cytidinediphosphate diacylglycerol, an essential precursor of anionic phosphoglycerolipids like phosphatidylglycerol or -inositol. In plant cells, CDS isozymes are located in plastids, mitochondria, and microsomes. Here, we show that these isozymes are encoded by five genes in Arabidopsis (Arabidopsis thaliana). Alternative translation initiation or alternative splicing of CDS2 and CDS4 transcripts can result in up to 10 isoforms. Most of the cDNAs encoding the various plant isoforms were functionally expressed in yeast and rescued the nonviable phenotype of the mutant strain lacking CDS activity. The closely related genes CDS4 and CDS5 were found to encode plastidial isozymes with similar catalytic properties. Inactivation of both genes was required to obtain Arabidopsis mutant lines with a visible phenotype, suggesting that the genes have redundant functions. Analysis of these Arabidopsis mutants provided further independent evidence for the importance of plastidial phosphatidylglycerol for structure and function of thylakoid membranes and, hence, for photoautotrophic growth. PMID:20442275

Fundamental parameters of the highly reddened young open clusters Westerlund 1 and 2

NASA Astrophysics Data System (ADS)

Piatti, A. E.; Bica, E.; Claria, J. J.

1998-02-01

We study the compact open clusters Westerlund1 (BH197) and Westerlund2. We present CCD integrated spectroscopy for both clusters, and CCD imaging in the V and I bands for the former one. So far, Westerlund1 is possibly the most reddened open cluster studied in detail (Av ~ 13.0). It has an age of 8 +/- 3 Myr and a distance from the Sun of d_sun ~ 1.0 +/- 0.4 kpc. For Westerlund2 we derive a visual absorption AV~ 5.0 mag, an age of 2-3 Myr, and d_sun=5.7+/- 0.3 kpc. From luminosity and structural arguments we conclude that Westerlund1, although young and compact, it is a massive cluster, in contrast to Westerlund2. Based on observations made at Complejo Astronómico El Leoncito, which is operated under agreement between the Consejo Nacional de Investigaciones Cientificas y Tecnicas de la Republica Argentina and the Universities of La Plata, Cordoba and San Juan, Argentina, and at the University of Toronto (David Dunlap Observatory) 24-inch telescope, Las Campanas, Chile. The photometric observations are available at CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

CeO₂ Enhanced Ethanol Sensing Performance in a CdS Gas Sensor.

PubMed

Li, Meishan; Ren, Wei; Wu, Rong; Zhang, Min

2017-07-05

CdS nanowires (NWs) were fabricated through a facile low-temperature solvothermal method, following which CeO₂ nanoparticles were modified on the NWs. The ethanol sensing characteristics of pure CdS and decorated ones with different CeO₂ content were studied. It was found that the sensing performance of CdS was significantly improved after CeO₂ decoration. In particular, the 5 at% CeO₂/CdS composite exhibited a much higher response to 100 ppm ethanol (about 52), which was 2.6 times larger than that of pure CdS. A fast response and recovery time (less than 12 s and 3 s, respectively) were obtained as well as an excellent selectivity. These results make the CeO₂-decorated CdS NWs good candidates for ethanol sensing applications.

Quick synthesis of 2-propanol derived fluorescent carbon dots for bioimaging applications

NASA Astrophysics Data System (ADS)

Angamuthu, Raja; Palanisamy, Priya; Vasudevan, Vasanthakumar; Nagarajan, Sedhu; Rajendran, Ramesh; Vairamuthu, Raj

2018-04-01

Herein, for the first time, we present a one-pot ingenious preparative method for fluorescent carbon dots from 2-propanol (2P-CDs) without external treatments. Structure, morphology, chemical composition and fluorescence properties of the 2P-CDs were examined. These results confirm that the as-synthesized 2P-CDs are amorphous, monodispersed, spherical and the average particle size is 2.5 ± 0.7 nm. Most importantly, excitation-dependent emission properties were observed, which suggest that these 2P-CDs may be used in multicolor bioimaging applications. When incubated with HeLa cells, the 2P-CDs exhibit low cytotoxicity, and positive biocompatibility. Confocal microscopy image shows the uptake of 2P-CDs by HeLa cells and the application of probable biomarker is demonstrated.

Optical characterization of CdS nanorods capped with starch

NASA Astrophysics Data System (ADS)

Roy, J. S.; Pal Majumder, T.; Schick, C.

2015-05-01

Well crystalline uniform CdS nanorods were grown by changing the concentration of maize starch. The highly polymeric (branched) structure of starch enhances the growth of CdS nanorods. The average diameter of the nanorods is 20-25 nm while length is of 500-600 nm as verified from SEM and XRD observations. The optical band gaps of the CdS nanorods are varying from 2.66 eV to 2.52 eV depending on concentration of maize starch. The photoluminescence (PL) emission bands are shifted from 526 nm to 529 nm with concentration of maize starch. We have also observed the enhanced PL intensity in CdS nanorods capped with starch. The Fourier transform infrared (FTIR) spectroscopy shows the significant effect of starch on CdS nanorods.

Green Synthesis of Bifunctional Fluorescent Carbon Dots from Garlic for Cellular Imaging and Free Radical Scavenging.

PubMed

Zhao, Shaojing; Lan, Minhuan; Zhu, Xiaoyue; Xue, Hongtao; Ng, Tsz-Wai; Meng, Xiangmin; Lee, Chun-Sing; Wang, Pengfei; Zhang, Wenjun

2015-08-12

Nitrogen and sulfur codoped carbon dots (CDs) were prepared from garlic by a hydrothermal method. The as-prepared CDs possess good water dispersibility, strong blue fluorescence emission with a fluorescent quantum yield of 17.5%, and excellent photo and pH stabilities. It is also demonstrated that the fluorescence of CDs are resistant to the interference of metal ions, biomolecules, and high ionic strength environments. Combining with low cytotoxicity properties, CDs could be used as an excellent fluorescent probe for cellular multicolor imaging. Moreover, the CDs were also demonstrated to exhibit favorable radical scavenging activity.

Synthesis and formation mechanistic investigation of nitrogen-doped carbon dots with high quantum yields and yellowish-green fluorescence

NASA Astrophysics Data System (ADS)

Hou, Juan; Wang, Wei; Zhou, Tianyu; Wang, Bo; Li, Huiyu; Ding, Lan

2016-05-01

Heteroatom doped carbon dots (CDs) have received increasing attention due to their unique properties and related applications. However, previously reported CDs generally show strong emission only in the blue-light region, thus restricting their further applications. And the fundamental investigation on the preparation process is always neglected. Herein, we have developed a simple and solvent-free synthetic strategy to fabricate nitrogen-doped CDs (N-CDs) from citric acid and dicyandiamide. The as-prepared N-CDs exhibited a uniform size distribution, strong yellowish-green fluorescence emission and a high quantum yield of 73.2%. The products obtained at different formation stages were detailedly characterized by transmission electron microscopy, X-ray diffraction spectrometer, X-ray photoelectron spectroscopy and UV absorbance spectroscopy. A possible formation mechanism has thus been proposed including dehydration, polymerization and carbonization. Furthermore, the N-CDs could serve as a facile and label-free probe for the detection of iron and fluorine ions with detection limits of 50 nmol L-1 and 75 nmol L-1, respectively.Heteroatom doped carbon dots (CDs) have received increasing attention due to their unique properties and related applications. However, previously reported CDs generally show strong emission only in the blue-light region, thus restricting their further applications. And the fundamental investigation on the preparation process is always neglected. Herein, we have developed a simple and solvent-free synthetic strategy to fabricate nitrogen-doped CDs (N-CDs) from citric acid and dicyandiamide. The as-prepared N-CDs exhibited a uniform size distribution, strong yellowish-green fluorescence emission and a high quantum yield of 73.2%. The products obtained at different formation stages were detailedly characterized by transmission electron microscopy, X-ray diffraction spectrometer, X-ray photoelectron spectroscopy and UV absorbance spectroscopy. A possible formation mechanism has thus been proposed including dehydration, polymerization and carbonization. Furthermore, the N-CDs could serve as a facile and label-free probe for the detection of iron and fluorine ions with detection limits of 50 nmol L-1 and 75 nmol L-1, respectively. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr02701f

Analysis of Nursing Clinical Decision Support Requests and Strategic Plan in a Large Academic Health System

PubMed Central

Bavuso, Karen; Bouyer-Ferullo, Sharon; Goldsmith, Denise; Fairbanks, Amanda; Gesner, Emily; Lagor, Charles; Collins, Sarah

2016-01-01

Summary Objectives To understand requests for nursing Clinical Decision Support (CDS) interventions at a large integrated health system undergoing vendor-based EHR implementation. In addition, to establish a process to guide both short-term implementation and long-term strategic goals to meet nursing CDS needs. Materials and Methods We conducted an environmental scan to understand current state of nursing CDS over three months. The environmental scan consisted of a literature review and an analysis of CDS requests received from across our health system. We identified existing high priority CDS and paper-based tools used in nursing practice at our health system that guide decision-making. Results A total of 46 nursing CDS requests were received. Fifty-six percent (n=26) were specific to a clinical specialty; 22 percent (n=10) were focused on facilitating clinical consults in the inpatient setting. “Risk Assessments/Risk Reduction/Promotion of Healthy Habits” (n=23) was the most requested High Priority Category received for nursing CDS. A continuum of types of nursing CDS needs emerged using the Data-Information-Knowledge-Wisdom Conceptual Framework: 1) facilitating data capture, 2) meeting information needs, 3) guiding knowledge-based decision making, and 4) exposing analytics for wisdom-based clinical interpretation by the nurse. Conclusion Identifying and prioritizing paper-based tools that can be modified into electronic CDS is a challenge. CDS strategy is an evolving process that relies on close collaboration and engagement with clinical sites for short-term implementation and should be incorporated into a long-term strategic plan that can be optimized and achieved overtime. The Data-Information-Knowledge-Wisdom Conceptual Framework in conjunction with the High Priority Categories established may be a useful tool to guide a strategic approach for meeting short-term nursing CDS needs and aligning with the organizational strategic plan. PMID:27437036

A novel fluorescent retrograde neural tracer: cholera toxin B conjugated carbon dots

NASA Astrophysics Data System (ADS)

Zhou, Nan; Hao, Zeyu; Zhao, Xiaohuan; Maharjan, Suraj; Zhu, Shoujun; Song, Yubin; Yang, Bai; Lu, Laijin

2015-09-01

The retrograde neuroanatomical tracing method is a key technique to study the complex interconnections of the nervous system. Traditional tracers have several drawbacks, including time-consuming immunohistochemical or immunofluorescent staining procedures, rapid fluorescence quenching and low fluorescence intensity. Carbon dots (CDs) have been widely used as a fluorescent bio-probe due to their ultrasmall size, excellent optical properties, chemical stability, biocompatibility and low toxicity. Herein, we develop a novel fluorescent neural tracer: cholera toxin B-carbon dot conjugates (CTB-CDs). It can be taken up and retrogradely transported by neurons in the peripheral nervous system of rats. Our results show that CTB-CDs possess high photoluminescence intensity, good optical stability, a long shelf-life and non-toxicity. Tracing with CTB-CDs is a direct and more economical way of performing retrograde labelling experiments. Therefore, CTB-CDs are reliable fluorescent retrograde tracers.The retrograde neuroanatomical tracing method is a key technique to study the complex interconnections of the nervous system. Traditional tracers have several drawbacks, including time-consuming immunohistochemical or immunofluorescent staining procedures, rapid fluorescence quenching and low fluorescence intensity. Carbon dots (CDs) have been widely used as a fluorescent bio-probe due to their ultrasmall size, excellent optical properties, chemical stability, biocompatibility and low toxicity. Herein, we develop a novel fluorescent neural tracer: cholera toxin B-carbon dot conjugates (CTB-CDs). It can be taken up and retrogradely transported by neurons in the peripheral nervous system of rats. Our results show that CTB-CDs possess high photoluminescence intensity, good optical stability, a long shelf-life and non-toxicity. Tracing with CTB-CDs is a direct and more economical way of performing retrograde labelling experiments. Therefore, CTB-CDs are reliable fluorescent retrograde tracers. Electronic supplementary information (ESI) available: PL spectra of CTB; absorption spectra of dialysate; fluorescence signal and immunohistochemical staining of CTB-CDs in L4 DRG. See DOI: 10.1039/c5nr04361a

Annealing effects on the chemical deposited CdS films and the electrical properties of CdS/CdTe solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Junfeng; Institute of Materials Science, Darmstadt University of Technology, Petersenstr. 23, 64287 Darmstadt; Liao, Cheng, E-mail: Cliao@pku.edu.cn

2011-02-15

Graphical abstract: From XPS core level spectras, compared with as-depositing CdS (sample A), the Fermi level is shifting closer to the conduction band after annealing treatment in the oxygen (sample B) while it is shifting closer to the valence band after annealing treatment in the argon-hydrogen (sample C). That might be the main reason of the different performance of the final devices. The open circuit voltage of the CdS/CdTe solar cell increases when the CBD CdS is annealed with oxygen, while the performance of the solar cell decreases when the CBD CdS is annealed with argon-hydrogen. Research highlights: {yields} Twomore » different methods (oxidation and reduction) were used to anneal CdS films for CdTe solar cells. {yields} Electrical properties were analyzed by XPS (Fermi levels of CdS films). {yields} Annealing treatment in oxidation atmosphere could shift Fermi level of CdS film to higher position and consequently improve the CdS/CdTe junction and performance of solar cells. -- Abstract: CdS layers grown by chemical bath deposition (CBD) are annealed in the oxygen and argon-hydrogen atmosphere respectively. It has been found that the open circuit voltage of the CdS/CdTe solar cell increases when the CBD CdS is annealed with oxygen before the deposition of CdTe by close spaced sublimation (CSS), while the performance of the solar cell decreases when the CBD CdS is annealed with argon-hydrogen. Electronic properties of the CdS films are investigated using X-ray photo-electron spectroscopy (XPS), which indicates that the Fermi level is shifting closer to the conduction band after annealing in the oxygen and consequently a higher open circuit voltage of the solar cell can be obtained.« less

Automation bias in electronic prescribing.

PubMed

Lyell, David; Magrabi, Farah; Raban, Magdalena Z; Pont, L G; Baysari, Melissa T; Day, Richard O; Coiera, Enrico

2017-03-16

Clinical decision support (CDS) in e-prescribing can improve safety by alerting potential errors, but introduces new sources of risk. Automation bias (AB) occurs when users over-rely on CDS, reducing vigilance in information seeking and processing. Evidence of AB has been found in other clinical tasks, but has not yet been tested with e-prescribing. This study tests for the presence of AB in e-prescribing and the impact of task complexity and interruptions on AB. One hundred and twenty students in the final two years of a medical degree prescribed medicines for nine clinical scenarios using a simulated e-prescribing system. Quality of CDS (correct, incorrect and no CDS) and task complexity (low, low + interruption and high) were varied between conditions. Omission errors (failure to detect prescribing errors) and commission errors (acceptance of false positive alerts) were measured. Compared to scenarios with no CDS, correct CDS reduced omission errors by 38.3% (p < .0001, n = 120), 46.6% (p < .0001, n = 70), and 39.2% (p < .0001, n = 120) for low, low + interrupt and high complexity scenarios respectively. Incorrect CDS increased omission errors by 33.3% (p < .0001, n = 120), 24.5% (p < .009, n = 82), and 26.7% (p < .0001, n = 120). Participants made commission errors, 65.8% (p < .0001, n = 120), 53.5% (p < .0001, n = 82), and 51.7% (p < .0001, n = 120). Task complexity and interruptions had no impact on AB. This study found evidence of AB omission and commission errors in e-prescribing. Verification of CDS alerts is key to avoiding AB errors. However, interventions focused on this have had limited success to date. Clinicians should remain vigilant to the risks of CDS failures and verify CDS.

Nanoniobia modification of CdS photoanode for an efficient and stable photoelectrochemical cell.

PubMed

Pareek, Alka; Paik, Pradip; Borse, Pramod H

2014-12-30

Herein we report the surface modification of a CdS film by niobia nanoparticles via thioglycerol as an organic linker and thus fabricate an efficient and a stable photoanode for a photoelectrochemical (PEC) cell. We have synthesized three differenly sized (∼3, ∼6 ,and ∼9 nm) niobia nanoparticles by a hydrothermal synthesis approach and have further investigated the particle-size-dependent PEC performance of the nanoparticle-modified CdS photoanode. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) confirm the formation of Nb2O5 nanoparticles that are prepared via decomposition of the niobium peroxo complex during the hydrothermal reaction and reveal the presence of surface OH(-) groups over niobia nanoparticles that impart a high catalytic property to a material. The nano-Nb2O5-modified photoanode displayed a 23-fold higher power conversion efficiency compared to that of CdS. This modified structure increases the open circuit voltage (OCV) from 0.65 to 0.77 V, which is attributed to the nano-Nb2O5-induced surface passivation effect over bare CdS. Linking of nanoparticles on the CdS surface improves the photocorrosion stability of the CdS photoanode for even longer than 4 h in contrast to the tens of minutes for the base CdS surface. The uniform coverage of the CdS photoanode surface by niobia nanoparticles is thus found to be the controlling parameter for achieving a higher PEC performance and stability of the photoanode. This finding directed us to design an improved CdS photoanode for efficient and prolonged PEC hydrogen generation from a PEC cell.

Recombinant yeast as a functional tool for understanding bitterness and cucurbitacin biosynthesis in watermelon (Citrullus spp.).

PubMed

Davidovich-Rikanati, Rachel; Shalev, Lior; Baranes, Nadine; Meir, Ayala; Itkin, Maxim; Cohen, Shahar; Zimbler, Kobi; Portnoy, Vitaly; Ebizuka, Yutaka; Shibuya, Masaaki; Burger, Yosef; Katzir, Nurit; Schaffer, Arthur A; Lewinsohn, Efraim; Tadmor, Ya'akov

2015-01-01

Cucurbitacins are a group of bitter-tasting oxygenated tetracyclic triterpenes that are produced in the family Cucurbitaceae and other plant families. The natural roles of cucurbitacins in plants are probably related to defence against pathogens and pests. Cucurbitadienol, a triterpene synthesized from oxidosqualene, is the first committed precursor to cucurbitacins produced by a specialized oxidosqualene cyclase termed cucurbitadienol synthase. We explored cucurbitacin accumulation in watermelon in relation to bitterness. Our findings show that cucurbitacins are accumulated in bitter-tasting watermelon, Citrullus lanatus var. citroides, as well as in their wild ancestor, C. colocynthis, but not in non-bitter commercial cultivars of sweet watermelon (C. lanatus var. lanatus). Molecular analysis of genes expressed in the roots of several watermelon accessions led to the isolation of three sequences (CcCDS1, CcCDS2 and ClCDS1), all displaying high similarity to the pumpkin CpCPQ, encoding a protein previously shown to possess cucurbitadienol synthase activity. We utilized the Saccharomyces cerevisiae strain BY4743, heterozygous for lanosterol synthase, to probe for possible encoded cucurbitadienol synthase activity of the expressed watermelon sequences. Functional expression of the two sequences isolated from C. colocynthis (CcCDS1 and CcCDS2) in yeast revealed that only CcCDS2 possessed cucurbitadienol synthase activity, while CcCDS1 did not display cucurbitadienol synthase activity in recombinant yeast. ClCDS1 isolated from C. lanatus var. lanatus is almost identical to CcCDS1. Our results imply that CcCDS2 plays a role in imparting bitterness to watermelon. Yeast has been an excellent diagnostic tool to determine the first committed step of cucurbitacin biosynthesis in watermelon. Copyright © 2014 John Wiley & Sons, Ltd.

Antimanic-like activity of candesartan in mice: Possible involvement of antioxidant, anti-inflammatory and neurotrophic mechanisms.

PubMed

de Souza Gomes, Júlia Ariana; de Souza, Greicy Coelho; Berk, Michael; Cavalcante, Lígia Menezes; de Sousa, Francisca Cléa F; Budni, Josiane; de Lucena, David Freitas; Quevedo, João; Carvalho, André F; Macêdo, Danielle

2015-11-01

Activation of the brain angiotensin II type 1 receptor (AT1R) triggers pro-oxidant and pro-inflammatory mechanisms which are involved in the neurobiology of bipolar disorder (BD). Candesartan (CDS) is an AT1 receptor antagonist with potential neuroprotective properties. Herein we investigated CDS effects against oxidative, neurotrophic inflammatory and cognitive effects of amphetamine (AMPH)-induced mania. In the reversal protocol adult mice were given AMPH 2 mg/kg i.p. or saline and between days 8 and 14 received CDS 0.1, 0.3 or 1 mg/kg orally, lithium (Li) 47.5 mg/kg i.p., or saline. In the prevention treatment, mice were pretreated with CDS, Li or saline prior to AMPH. Locomotor activity and working memory performance were assessed. Glutathione (GSH), thiobarbituric acid-reactive substance (TBARS) and TNF-α levels were evaluated in the hippocampus (HC) and cerebellar vermis (CV). Brain-derived neurotrophic factor (BDNF) and glycogen synthase kinase 3-beta (GSK-3beta) levels were measured in the HC. CDS and Li prevented and reversed the AMPH-induced increases in locomotor activity. Only CDS prevented and reversed AMPH-induced working memory deficits. CDS prevented AMPH-induced alterations in GSH (HC and CV), TBARS (HC and CV), TNF-α (HC and CV) and BDNF (HC) levels. Li prevented alterations in BDNF and phospho-Ser9-GSK3beta. CDS reversed AMPH-induced alterations in GSH (HC and CV), TBARS (HC), TNF-α (CV) and BDNF levels. Li reversed AMPH-induced alterations in TNF-α (HC and CV) and BDNF (HC) levels. CDS is effective in reversing and preventing AMPH-induced behavioral and biochemical alterations, providing a rationale for the design of clinical trials investigating CDS׳s possible therapeutic effects. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

Structural and Optical Properties of Core-Shell TiO2/CdS Prepared by Chemical Bath Deposition

NASA Astrophysics Data System (ADS)

Al-Jawad, Selma M. H.

2017-10-01

Titanium dioxide (TiO2) nanorod arrays (NRAs) sensitized with cadmium sulfide (CdS) nanoparticles (NPs) were deposited by chemical bath deposition (CBD). TiO2 NRAs were also obtained by using the same method on glass substrates coated with fluorine-doped tin oxide (FTO). The structure of the FTO/TiO2/CdS core-shell was characterized by x-ray diffraction (XRD), atomic force microscopy, scanning electron microscopy, ultraviolet-visible (UV-Vis) absorption spectroscopy, photoluminescence, and photoelectrocatalysis of FTO/TiO2 and FTO/TiO2/CdS. The FTO/TiO2 conformed to anatase and rutile phase structures for different pH values and also with annealing. XRD patterns of the FTO/TiO2/CdS sample exhibited two peaks corresponding to hexagonal (100) and (101) for CdS. Scanning electron micrographs showed nanorod structures for the TiO2 thin films deposited at a pH value equal 0.7. Optical results showed the CdS deposited on nanorod TiO2 exhibited increased absorption ability in the visible light, indicating an increased photocatalytic activity for TiO2/CdS core-shell nanorods in the visible light. When illuminated with a UV-Vis light source, the TiO2/CdS core-shell films displayed high responses. A composite exists between the TiO2 nanostructure and CdS NPs because the film absorbs the incident light located in both the visible and UV-Vis regions. A higher response to UV-Vis light was attained with the use of TiO2 NRAs/CdS NPs films prepared by CBD. This approach offers a technique for fabricating photoelectrodes.

Clinical Decision Support: a 25 Year Retrospective and a 25 Year Vision.

PubMed

Middleton, B; Sittig, D F; Wright, A

2016-08-02

The objective of this review is to summarize the state of the art of clinical decision support (CDS) circa 1990, review progress in the 25 year interval from that time, and provide a vision of what CDS might look like 25 years hence, or circa 2040. Informal review of the medical literature with iterative review and discussion among the authors to arrive at six axes (data, knowledge, inference, architecture and technology, implementation and integration, and users) to frame the review and discussion of selected barriers and facilitators to the effective use of CDS. In each of the six axes, significant progress has been made. Key advances in structuring and encoding standardized data with an increased availability of data, development of knowledge bases for CDS, and improvement of capabilities to share knowledge artifacts, explosion of methods analyzing and inferring from clinical data, evolution of information technologies and architectures to facilitate the broad application of CDS, improvement of methods to implement CDS and integrate CDS into the clinical workflow, and increasing sophistication of the end-user, all have played a role in improving the effective use of CDS in healthcare delivery. CDS has evolved dramatically over the past 25 years and will likely evolve just as dramatically or more so over the next 25 years. Increasingly, the clinical encounter between a clinician and a patient will be supported by a wide variety of cognitive aides to support diagnosis, treatment, care-coordination, surveillance and prevention, and health maintenance or wellness.

Effect of silver doping on the elastic properties of CdS nanoparticles

NASA Astrophysics Data System (ADS)

Dey, P. C.; Das, R.

2018-05-01

CdS and Ag doped CdS (CdS/Ag) nanoparticles have been prepared via chemical method from a Cadmium acetate precursor and Thiourea. The synthesized CdS and CdS/Ag nanoparticles have been characterized by the X-ray Diffraction and High Resolution Transmission Electron Microscope. Here, these nanoparticles have been synthesized at room temperature and all the characterization have also been done at room temperature only. The XRD results reveal that the products are crystalline with cubic zinc blende structure. HRTEM images show that the prepared nanoparticles are nearly spherical in shape. Williamson-Hall method and Size-Strain Plot (SSP) have been used to study the individual contribution of crystalline sizes and lattice strain on the peak broadening of the CdS and CdS/Ag nanoparticles. The different modified model of Williamson-Hall method such as, uniform deformation model, uniform stress deformation model and uniform energy density deformation model and SSP method have been used to calculate the different physical parameter such as lattice strain, stress and energy density for all diffraction peaks of the XRD, corresponding to the CdS and silver doped CdS (CdS/Ag). The obtained results reveal that the average particle size of the prepared CdS and CdS/Ag nanoparticles estimated from the HRTEM images, Williamson-Hall analysis and SSP method are highly correlated with each other. Further, all these result confirms that doping of Ag significantly affects the elastic properties of CdS.

Tricolor White-Light-Emitting Carbon Dots with Multiple-Cores@Shell Structure for WLED Application.

PubMed

Zhang, Tianyi; Zhao, Feifei; Li, Li; Qi, Bin; Zhu, Dongxia; Lü, Jianhua; Lü, Changli

2018-06-13

The past few years have witnessed the rapid development of carbon dots (CDs) due to their outstanding optical properties and a wide range of applications. However, the design and control of CDs with long-wavelength multicolor emission are still huge challenges to be addressed for their practical use in different fields. Here, novel nitrogen-doped multiple-core@shell-structured AC-CDs with tricolor emissions of red, green, and blue were constructed via one-pot hydrothermal method from 5-amino-1,10-phenanthroline and citric acid as reactants and the growth process of AC-CDs was monitored with the reaction time in the synthetic system. The origin of different fluorescence emissions was explored using the unique coordination ability of the surface groups of AC-CDs. An obvious concentration dependence of fluorescent properties was observed for the as-prepared AC-CDs, and a highly fluorescent quantum yield (QY) of 67% for red emission at 630 nm can be obtained by adjusting concentration of AC-CDs. The pure white-light emission (0.33, 0.33; Commission Internationale de l'Elcairage coordinate) was carried out from single carbon dot with QY of 29% through regulation of the excitation and concentration of multiple-core@shell-structured AC-CDs. In addition, because of their excellent photoluminescent properties, the white-emitting AC-CDs as emitting phosphor can be easily used in the fabrication of white-light-emitting diode with good anti-photobleaching and temperature stability.

Turn-off fluorescence sensor for the detection of ferric ion in water using green synthesized N-doped carbon dots and its bio-imaging.

PubMed

Edison, Thomas Nesakumar Jebakumar Immanuel; Atchudan, Raji; Shim, Jae-Jin; Kalimuthu, Senthilkumar; Ahn, Byeong-Cheol; Lee, Yong Rok

2016-05-01

This paper reports turn-off fluorescence sensor for Fe(3+) ion in water using fluorescent N-doped carbon dots as a probe. A simple and efficient hydrothermal carbonization of Prunus avium fruit extract for the synthesis of fluorescent nitrogen-doped carbon dots (N-CDs) is described. This green approach proceeds quickly and provides good quality N-CDs. The mean size of synthesized N-CDs was approximately 7nm calculated from the high-resolution transmission electron microscopic images. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy revealed the presence of -OH, -NH2, -COOH, and -CO functional groups over the surface of CDs. The N-CDs showed excellent fluorescent properties, and emitted blue fluorescence at 411nm upon excitation at 310nm. The calculated quantum yield of the synthesized N-CDs is 13% against quinine sulfate as a reference fluorophore. The synthesized N-CDs were used as a fluorescent probe towards the selective and sensitive detection of biologically important Fe(3+) ions in water by fluorescence spectroscopy and for bio-imaging of MDA-MB-231 cells. The limit of detection (LOD) and the Stern-Volmer quenching constant for the synthesized N-CDs were 0.96μM and 2.0958×10(3)M of Fe(3+) ions. The green synthesized N-CDs are efficiently used as a promising candidate for the detection of Fe(3+) ions and bio-imaging. Copyright © 2016 Elsevier B.V. All rights reserved.

Rapid Synthesis of Carbon Dots by Hydrothermal Treatment of Lignin

PubMed Central

Chen, Wenxin; Hu, Chaofan; Yang, Yunhua; Cui, Jianghu; Liu, Yingliang

2016-01-01

A rapid approach has been developed for the fluorescent carbon dots (CDs) by the hydrothermal treatment of lignin in the presence of H2O2. The as-synthesized CDs were found to emit blue photoluminescence with excellent photostability. Moreover, the CDs displayed biocompatibility, low cytotoxicity, and high water solubility properties. Finally, the as-resulted CDs were demonstrated to be excellent probes for bioimaging and biosensing applications. PMID:28773309

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Bo; Zhang, Xiaosong, E-mail: zhangxiaosong@tjut.edu.cn; Li, Lan

Trap-rich CdS nanocrystals were synthesized by employing CdSt{sub 2} and sulfur as precursors via thermal decomposition. Furthermore, X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), absorption and photoluminescence (PL) spectra were used to characterize structure, morphology and luminescence properties of CdS nanocrystals (NCs). CdS NCs have a broad emission across 500–700 nm under the excitation of blue light with 460 nm, consequently, white light can be produced by mixing broad emission from CdS NCs excited by blue light, with the remaining blue light. In addition, the broad emission generation is closely and inseparably related to surface defects. Moreover, LaMer modelmore » was used to explain the phenomenon that the intensity of the trap emission gradually decreases as the reaction time increases in contrast with that of the band-edge emission. - Graphical abstract: Trap-rich CdS nanocrystals were synthesized. Furthermore, white light is produced by mixing broad emission across 500–700 nm from CdS NCs excited by blue light, in combination with the remaining blue light. - Highlights: • Trap-rich CdS nanocrystals were synthesized. • CdS NCs have a broad emission across 500–700 nm under the excitation of blue light. • White light can be produced by mixing broad emission with the remaining blue light.« less

One-step hydrothermal synthesis of chiral carbon dots and their effects on mung bean plant growth.

PubMed

Zhang, Mengling; Hu, Lulu; Wang, Huibo; Song, Yuxiang; Liu, Yang; Li, Hao; Shao, Mingwang; Huang, Hui; Kang, Zhenhui

2018-06-27

Chiral compounds/materials have important effects on the growth of plants. Chiral carbon dots (CDs), as an emerging chiral carbon nanomaterial, have great potential in bio-application and bio-nanotechnology. Herein, we report a hydrothermal method to synthesize chiral CDs from cysteine (cys) and citric acid. These chiral CDs were further demonstrated to have systemic effects on the growth of mung bean plants, in which case both l- and d-CDs can promote the growth of the root in mung bean plants, stem length of mung bean sprouts and water absorption of bean seeds. The elongation of mung bean sprouts presented an increasing trend with the treatment of chiral CDs of increasing concentration (below 500 μg mL-1). Furthermore, in the optimal concentration (100 μg mL-1), the l-CDs can improve root vigor and the activity of the Rubisco enzyme of bean sprouts by 8.4% and 20.5%, while the d-CDs increased by 28.9% and 67.5%. Due to more superior properties in improving root vigor and the activity of the Rubisco enzyme of mung bean sprouts, d-CDs are able to enhance photosynthesis better and accumulate more carbohydrate in mung bean plants.

Ultrasensitive detection of amifostine and alkaline phosphatase based on the growth of CdS quantum dots.

PubMed

Na, Weidan; Liu, Siyu; Liu, Xiaotong; Su, Xingguang

2015-11-01

In this study, we reported a simple and sensitive fluorescence nanosensor for rapid detection of amifostine and alkaline phosphatase (ALP). The novel nanosensor was based on the fluorescence "turn on-off" of CdS quantum dots (QDs). Firstly, Cd(2+) cation could react with S(2-) anion to generate fluorescent CdS QDs in the presence of amifostine. The fluorescence (FL) intensity of amifostine-capped CdS QDs (Amifostine-CdS QDs) was increased with the increasing amounts of amifostine, and could be used for amifostine detection. However, amifostine could be converted to 2-(3-aminopropylamino) ethanethiol (WR1065) in the presence of ALP based on the dephosphorylation of ALP. Under the optimum conditions, the affinity of WR1065 to CdS QDs was weaker than that of amifostine. Therefore the new generation of WR1065-CdS QDs would reduce the FL intensity with the increase of ALP concentration, and the fluorescence of CdS QDs was turn off. The metabolic process of amifostine in the presence of alkaline phosphatase could be also studied via the change of FL intensity of CdS QDs. The present method was cost-effective, convenient, and does not require any complicated synthetic procedures. Copyright © 2015 Elsevier B.V. All rights reserved.

A proposed clinical decision support architecture capable of supporting whole genome sequence information.

PubMed

Welch, Brandon M; Loya, Salvador Rodriguez; Eilbeck, Karen; Kawamoto, Kensaku

2014-04-04

Whole genome sequence (WGS) information may soon be widely available to help clinicians personalize the care and treatment of patients. However, considerable barriers exist, which may hinder the effective utilization of WGS information in a routine clinical care setting. Clinical decision support (CDS) offers a potential solution to overcome such barriers and to facilitate the effective use of WGS information in the clinic. However, genomic information is complex and will require significant considerations when developing CDS capabilities. As such, this manuscript lays out a conceptual framework for a CDS architecture designed to deliver WGS-guided CDS within the clinical workflow. To handle the complexity and breadth of WGS information, the proposed CDS framework leverages service-oriented capabilities and orchestrates the interaction of several independently-managed components. These independently-managed components include the genome variant knowledge base, the genome database, the CDS knowledge base, a CDS controller and the electronic health record (EHR). A key design feature is that genome data can be stored separately from the EHR. This paper describes in detail: (1) each component of the architecture; (2) the interaction of the components; and (3) how the architecture attempts to overcome the challenges associated with WGS information. We believe that service-oriented CDS capabilities will be essential to using WGS information for personalized medicine.

A Proposed Clinical Decision Support Architecture Capable of Supporting Whole Genome Sequence Information

PubMed Central

Welch, Brandon M.; Rodriguez Loya, Salvador; Eilbeck, Karen; Kawamoto, Kensaku

2014-01-01

Whole genome sequence (WGS) information may soon be widely available to help clinicians personalize the care and treatment of patients. However, considerable barriers exist, which may hinder the effective utilization of WGS information in a routine clinical care setting. Clinical decision support (CDS) offers a potential solution to overcome such barriers and to facilitate the effective use of WGS information in the clinic. However, genomic information is complex and will require significant considerations when developing CDS capabilities. As such, this manuscript lays out a conceptual framework for a CDS architecture designed to deliver WGS-guided CDS within the clinical workflow. To handle the complexity and breadth of WGS information, the proposed CDS framework leverages service-oriented capabilities and orchestrates the interaction of several independently-managed components. These independently-managed components include the genome variant knowledge base, the genome database, the CDS knowledge base, a CDS controller and the electronic health record (EHR). A key design feature is that genome data can be stored separately from the EHR. This paper describes in detail: (1) each component of the architecture; (2) the interaction of the components; and (3) how the architecture attempts to overcome the challenges associated with WGS information. We believe that service-oriented CDS capabilities will be essential to using WGS information for personalized medicine. PMID:25411644

One-pot synthesis of CdS nanocrystals hybridized with single-layer transition-metal dichalcogenide nanosheets for efficient photocatalytic hydrogen evolution.

PubMed

Chen, Junze; Wu, Xue-Jun; Yin, Lisha; Li, Bing; Hong, Xun; Fan, Zhanxi; Chen, Bo; Xue, Can; Zhang, Hua

2015-01-19

Exploration of low-cost and earth-abundant photocatalysts for highly efficient solar photocatalytic water splitting is of great importance. Although transition-metal dichalcogenides (TMDs) showed outstanding performance as co-catalysts for the hydrogen evolution reaction (HER), designing TMD-hybridized photocatalysts with abundant active sites for the HER still remains challenge. Here, a facile one-pot wet-chemical method is developed to prepare MS2-CdS (M=W or Mo) nanohybrids. Surprisedly, in the obtained nanohybrids, single-layer MS2 nanosheets with lateral size of 4-10 nm selectively grow on the Cd-rich (0001) surface of wurtzite CdS nanocrystals. These MS2-CdS nanohybrids possess a large number of edge sites in the MS2 layers, which are active sites for the HER. The photocatalytic performances of WS2-CdS and MoS2-CdS nanohybrids towards the HER under visible light irradiation (>420 nm) are about 16 and 12 times that of pure CdS, respectively. Importantly, the MS2-CdS nanohybrids showed enhanced stability after a long-time test (16 h), and 70% of catalytic activity still remained. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

MWCNT/CdS hybrid nanocomposite for enhanced photocatalytic activity

NASA Astrophysics Data System (ADS)

Chaudhary, Deepti; Khare, Neeraj; Vankar, V. D.

2016-05-01

Multi-walled carbon nanotubes (MWCNT)/CdS hybrid nanocomposite were synthesized by one step hydrothermal method. MWCNTs were used as a substrate for the growth of CdS nanoparticles. MWCNT/CdS nanocomposite and pure CdS were characterized by XRD, TEM, UV-vis and photoluminescence spectroscopy. HRTEM study confirms the intimate contact of CdS with MWCNT. The photocatalytic activity of nanocomposite was studied for the degradation of methylene blue dye under UV irradiation. The enhanced photocatalytic activity of MWCNT/CdS nanocomposite as compared to pure CdS has been attributed to reduced recombination of photogenerated charge carriers due to interfacial electron transfer from CdS to MWCNT.

VizieR Online Data Catalog: SAMI Galaxy Survey: gas streaming (Cecil+, 2016)

NASA Astrophysics Data System (ADS)

Cecil, G.; Fogarty, L. M. R.; Richards, S.; Bland-Hawthorn, J.; Lange, R.; Moffett, A.; Catinella, B.; Cortese, L.; Ho, I.-T.; Taylor, E. N.; Bryant, J. J.; Allen, J. T.; Sweet, S. M.; Croom, S. M.; Driver, S. P.; Goodwin, M.; Kelvin, L.; Green, A. W.; Konstantopoulos, I. S.; Owers, M. S.; Lawrence, J. S.; Lorente, N. P. F.

2016-08-01

From the first ~830 targets observed in the SGS, we selected 344 rotationally supported galaxies having enough gas to map their CSC. We rejected 8 whose inclination angle to us is too small (i<20°) to be established reliably by photometry, and those very strongly barred or in obvious interactions. Finally, we rejected those whose CSC would be smeared excessively by our PSF (Sect. 2.3.1) because of large inclination (i>71°), compact size, or observed in atrocious conditions, leaving 163 SGS GAMA survey sub-sample and 15 "cluster" sub-sample galaxies with discs. (3 data files).

CdS nanoparticles immobilized on porous carbon polyhedrons derived from a metal-organic framework with enhanced visible light photocatalytic activity for antibiotic degradation

NASA Astrophysics Data System (ADS)

Yang, Cao; Cheng, Jianhua; Chen, Yuancai; Hu, Yongyou

2017-10-01

The CdS/MOF-derived porous carbon (MPC) composite as an efficient visible-light-driven photocatalyst was prepared through the pyrolysis of ZIF-8 and subsequent growth of CdS. The porous and functionalized MPC enables intimate and discrete growth of CdS nanoparticles. This unique structure not only reduces the bulk recombination owing to nano-size effect of CdS, but also suppresses the surface recombination due to the discrete growth of CdS nanoparticles on MPC polyhedrons, which facilitates electron transfer and charge separation. Moreover, such a composite material possessed good adsorption ability toward the antibiotic pollutants because of the amino-functionalized surface. As a result, the as-prepared CdS/MPC composites showed excellent photocatalytic performance for the antibiotic degradation, significantly improving the photoactivity of CdS. Importantly, the CdS/MPC composite with the CdS loading of 20 wt% exhibited the highest photocatalytic efficiency of approximately 91% and apparent rate constant of 0.024 min-1.

Synthesis of pore-variable mesoporous CdS and evaluation of its photocatalytic activity in degrading methylene blue

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Wei-Min, E-mail: chm_zhangwm@ujn.edu.cn; Jiang, Yao-Quan; Cao, Xiao-Yan

2013-10-15

Graphical abstract: - Highlights: • Self-templated synthesis of tubular CdS. • Cadmium complexes of aliphatic acids sustain the network of mesoporous structures. • Aliphatic acids affect the phase composition and particle size. • Pore size and volume vary with aliphatic acids having different hydrocarbonyl. - Abstract: In this study, mesoporous CdS polycrystallites have been synthesized using aliphatic acids of hexanoic acid, octanoic acid, and oleic acid as coordinating and capping agents, respectively. The fibrous Cd–fatty acid salts act as a template to form the tubular CdS. The organic species are found to be necessary for maintaining the network of mesoporousmore » CdS. The characterization results indicate that the shorter carbon chain length in aliphatic acids favors the wurtzite phase and particle size growth the specific surface area, pore diameter and pore volume show a monotonic raise with increasing carbon chain. The photocatalytic activities of mesoporous CdS tubes exhibit much higher efficiency than those of nanosized CdS powders in decolorizing methylene blue under simulated visible light.« less

Structural and Spectroscopic Studies of Sm3+/CdS Nanocrystallites in Sol-Gel TiO2-ZrO2 Matrix

NASA Astrophysics Data System (ADS)

Karthika, S.; Prathibha, Vasudevan; Ann, Mary K. A.; Viji, Vidyadharan; Biju, P. R.; Unnikrishnan, N. V.

2014-02-01

A sol-gel method was used to prepare titania-zirconia matrices doped with Sm3+/CdS nanocrystallites. The structural properties of the matrices were characterized using transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and Fourier-transform infrared spectroscopy studies. The thermal stability of the material was determined by TGA/DTA analysis. The absorption spectrum shows the characteristic peaks of the Sm3+ ions and the absorption peak corresponding to the CdS nanocrystallites. The optical bandgap and size of the CdS nanoparticles were calculated from the absorption spectrum. From TEM, the interplanar distance ( d) was estimated to be 3.533 Å, which matches with the (1 0 0) plane of bulk CdS. The measurements yield a nanocrystallite size of around 7.8 nm. The optical absorption and emission spectra confirmed the formation of CdS nanoparticles along with samarium ions in the titania-zirconia matrices. The fluorescence intensity of the samarium ions was found to be greatly enhanced by codoping with CdS nanocrystallites.

Effects of air annealing on CdS quantum dots thin film grown at room temperature by CBD technique intended for photosensor applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaikh, Shaheed U.; Desale, Dipalee J.; Siddiqui, Farha Y.

2012-11-15

Graphical abstract: The effect of different intensities (40, 60 100 and 200 W) of light on CdS quantum dots thin film annealed at 350 °C indicating enhancement in (a) photo-current and (b) photosensitivity. Highlights: ► The preparation of CdS nanodot thin film at room temperature by M-CBD technique. ► Study of air annealing on prepared CdS nanodots thin film. ► The optimized annealing temperature for CdS nanodot thin film is 350 °C. ► Modified CdS thin films can be used in photosensor application. -- Abstract: CdS quantum dots thin-films have been deposited onto the glass substrate at room temperature usingmore » modified chemical bath deposition technique. The prepared thin films were further annealed in air atmosphere at 150, 250 and 350 °C for 1 h and subsequently characterized by scanning electron microscopy, ultraviolet–visible spectroscopy, electrical resistivity and I–V system. The modifications observed in morphology and opto-electrical properties of the thin films are presented.« less

Additive interaction of carbon dots extracted from soluble coffee and biogenic silver nanoparticles against bacteria

NASA Astrophysics Data System (ADS)

Andrade, Patricia F.; Nakazato, Gerson; Durán, Nelson

2017-06-01

It is known the presence of carbon dots (CDs) in carbohydrate based foods. CDs extracted from coffee grounds and instant coffee was also published. CDs from soluble coffee revealed an average size of 4.4 nm. CDs were well-dispersed in water, fluorescent and we have characterized by XPS, XRD analysis, fluorescence and by FTIR spectra. The MIC value by serial micro-dilution assays for CDs on S. aureus ATCC 25923 was 250 μg/mL and E. coli ATCC 25922 >1000 ug/mL. For silver nanoparticles biogenically synthesized was 6.7 μg/mL. Following the checkerboard assay with combining ½ MIC values of the MICs of 125 μg/mL of carbon dots and 3.4 μg/mL of silver nanoparticles, following the fractionated inhibitory concentration (FIC) index methodology, on S. aureus gave a fractionated inhibitory concentration (FIC) value of 1.0, meaning additive interaction. In general, the unfunctionalized CDs showed to be inefficient as antibacterial compounds, however the CDs extracted from Coffee powder and together silver nanoparticles appeared interesting as antibacterial association.

Damage tolerance protein Mus81 associates with the FHA1 domain of checkpoint kinase Cds1.

PubMed

Boddy, M N; Lopez-Girona, A; Shanahan, P; Interthal, H; Heyer, W D; Russell, P

2000-12-01

Cds1, a serine/threonine kinase, enforces the S-M checkpoint in the fission yeast Schizosaccharomyces pombe. Cds1 is required for survival of replicational stress caused by agents that stall replication forks, but how Cds1 performs these functions is largely unknown. Here we report that the forkhead-associated-1 (FHA1) protein-docking domain of Cds1 interacts with Mus81, an evolutionarily conserved damage tolerance protein. Mus81 has an endonuclease homology domain found in the XPF nucleotide excision repair protein. Inactivation of mus81 reveals a unique spectrum of phenotypes. Mus81 enables survival of deoxynucleotide triphosphate starvation, UV radiation, and DNA polymerase impairment. Mus81 is essential in the absence of Bloom's syndrome Rqh1 helicase and is required for productive meiosis. Genetic epistasis studies suggest that Mus81 works with recombination enzymes to properly replicate damaged DNA. Inactivation of Mus81 triggers a checkpoint-dependent delay of mitosis. We propose that Mus81 is involved in the recruitment of Cds1 to aberrant DNA structures where Cds1 modulates the activity of damage tolerance enzymes.

Effects of experimental conditions on the morphologies, structures and growth modes of pulsed laser-deposited CdS nanoneedles

PubMed Central

2014-01-01

CdS nanoneedles with different morphologies, structures, and growth modes have been grown on Ni-coated Si(100) surface under different experimental conditions by pulsed laser deposition method. The effects of catalyst layer, substrate temperature, and laser pulse energy on the growth of the CdS nanoneedles were studied in detail. It was confirmed that the formation of the molten catalyst spheres is the key to the nucleation of the CdS nanoneedles by observing the morphologies of the Ni catalyst thin films annealed at different substrate temperatures. Both the substrate temperature and laser pulse energy strongly affected the growth modes of the CdS nanoneedles. The secondary growth of the smaller nanoneedles on the top of the main nanoneedles was found at appropriate conditions. A group of more completed pictures of the growth modes of the CdS nanoneedles were presented. PMID:24559455

Recommendations for Clinical Decision Support Deployment: Synthesis of a Roundtable of Medical Directors of Information Systems

PubMed Central

Jenders, Robert A.; Osheroff, Jerome A.; Sittig, Dean F.; Pifer, Eric A.; Teich, Jonathan M

2007-01-01

Background: Ample evidence exists that clinical decision support (CDS) can improve clinician performance. Nevertheless, additional evidence demonstrates that clinicians still do not perform adequately in many instances. This suggests an ongoing need for implementation of CDS, in turn prompting development of a roadmap for national action regarding CDS. Objective: Develop practical advice to aid CDS implementation in order to improve clinician performance. Method: Structured group interview during a roundtable discussion by medical directors of information systems (N = 30), with subsequent review by participants and synthesis. Results: Participant consensus was that CDS should be comprehensive and should involve techniques such as order sets and facilitated documentation as well as alerts; should be subject to ongoing feedback; and should flow from and be governed by an organization’s clinical goals. Conclusion: A structured roundtable discussion of clinicians experienced in health information technology can yield practical, consensus advice for implementation of CDS. PMID:18693858

Hydrothermal synthesis of nitrogen-doped carbon dots with real-time live-cell imaging and blood-brain barrier penetration capabilities.

PubMed

Lu, Shousi; Guo, Shanshan; Xu, Pingxiang; Li, Xiaorong; Zhao, Yuming; Gu, Wei; Xue, Ming

Nitrogen-doped carbon dots (N-CDs) were synthesized using a one-pot hydrothermal treatment with citric acid in the presence of polyethylenimine. Transmission electron microscopy analysis revealed that the N-CDs were monodispersed and quasi-spherical with an average size of ~2.6 nm. Under ultraviolet irradiation the N-CDs emitted a strong blue luminescence with a quantum yield as high as 51%. Moreover, the N-CDs exhibited a negligible cytotoxicity and could be applied as efficient nanoprobes for real-time imaging of live cells. In addition, the ability of the N-CDs to cross the blood-brain barrier (BBB) in a concentration-dependent manner was demonstrated using an in vitro BBB model. Therefore, these PEI-passivated N-CDs with real-time live-cell imaging and BBB-penetration capabilities hold promise for traceable drug delivery to the brain.

Highly fluorescent carbon dots for visible sensing of doxorubicin release based on efficient nanosurface energy transfer.

PubMed

Wang, Beibei; Wang, Shujun; Wang, Yanfang; Lv, Yan; Wu, Hao; Ma, Xiaojun; Tan, Mingqian

2016-01-01

To prepare fluorescent carbon dots for loading cationic anticancer drug through donor-quenched nanosurface energy transfer in visible sensing of drug release. Highly fluorescent carbon dots (CDs) were prepared by a facile hydrothermal approach from citric acid and o-phenylenediamine. The obtained CDs showed a high quantum yield of 46 % and exhibited good cytocompatibility even at 1 mg/ml. The cationic anticancer drug doxorubicin (DOX) can be loaded onto the negatively charged CDs through electrostatic interactions. Additionally, the fluorescent CDs feature reversible donor-quenched mode nanosurface energy transfer. When loading the energy receptor DOX, the donor CDs' fluorescence was switched "off", while it turned "on" again after DOX release from the surface through endocytic uptake. Most DOX molecules were released from the CDs after 6 h incubation and entered cell nuclear region after 8 h, suggesting the drug delivery system may have potential for visible sensing in drug release.

One-pot synthesis of fluorescent nitrogen-doped carbon dots with good biocompatibility for cell labeling.

PubMed

Zhang, Zhengwei; Yan, Kun; Yang, Qiulian; Liu, Yanhua; Yan, Zhengyu; Chen, Jianqiu

2017-12-01

Here we report an easy and economical hydrothermal carbonization approach to synthesize the fluorescent nitrogen-doped carbon dots (N-CDs) that was developed using citric acid and triethanolamine as the precursors. The synthesis conditions were optimized to obtain the N-CDs with superior fluorescence performances. The as-prepared N-CDs are monodispersed sphere nanoparticles with good water solubility, and exhibited strong fluorescence, favourable photostability and excitation wavelength-dependent behavior. Furthermore, the in vitro cytotoxicity and cellular labeling of N-CDs were investigated using the rat glomerular mesangial cells. The results showed the N-CDs have more inconspicuous cytotoxicity and better biosafety in comparison with ZnSe quantum dots, although both targeted the cells successfully. Considering their admirable photostability, low toxicity and good compatibility, the as-obtained N-CDs could have potential applications in biosensors, cellular imaging, and other fields. Copyright © 2017 John Wiley & Sons, Ltd.

Hydrothermal synthesis of nitrogen-doped carbon dots with real-time live-cell imaging and blood–brain barrier penetration capabilities

PubMed Central

Lu, Shousi; Guo, Shanshan; Xu, Pingxiang; Li, Xiaorong; Zhao, Yuming; Gu, Wei; Xue, Ming

2016-01-01

Nitrogen-doped carbon dots (N-CDs) were synthesized using a one-pot hydrothermal treatment with citric acid in the presence of polyethylenimine. Transmission electron microscopy analysis revealed that the N-CDs were monodispersed and quasi-spherical with an average size of ~2.6 nm. Under ultraviolet irradiation the N-CDs emitted a strong blue luminescence with a quantum yield as high as 51%. Moreover, the N-CDs exhibited a negligible cytotoxicity and could be applied as efficient nanoprobes for real-time imaging of live cells. In addition, the ability of the N-CDs to cross the blood–brain barrier (BBB) in a concentration-dependent manner was demonstrated using an in vitro BBB model. Therefore, these PEI-passivated N-CDs with real-time live-cell imaging and BBB-penetration capabilities hold promise for traceable drug delivery to the brain. PMID:27932880

[Screening for depersonalization-derealization with two items of the cambridge depersonalization scale].

PubMed

Michal, Matthias; Zwerenz, Rüdiger; Tschan, Regine; Edinger, Jens; Lichy, Marcel; Knebel, A; Tuin, Inka; Beutel, Manfred

2010-05-01

Depersonalization (DP) and derealization (DR) are considered to be highly underdiagnosed. Therefore the development of screening instruments is important. From the Cambridge Depersonalization Scale (CDS) two items were extracted discriminating best patients with clinical significant DP from patients without DP. These two Items were assembled to a short version of the CDS. This short version (CDS-2) was tested in a sample of 38 patients with clinical significant DP-DR and 49 patients without or only mild DP-DR. Scores were compared against clinical diagnoses based on a structured interview (gold standard). The CDS-2 was able to differentiate patients with clinical significant DP well from other groups (cut-off of CDS-2>or=3, sensitivity=78.9%, specifity=85.7%) and also showed high reliability (Cronbachs alpha=0.92). Therefore the CDS-2 can be considered as a useful tool for screening and identification of DP-DR.

Resources and rewards for clerkship directors: how surgery compares.

PubMed

Ephgrave, Kimberly; Ferguson, Kristi; Shaaban, Aimen; Hoshi, Hisakazu

2010-01-01

Clerkship directors (CDs) are key educators and active clinicians. In 2003, the Alliance for Clinical Education published standards for CD resources and responsibilities, but how reality compares is unknown. Representatives from each core clinical disciplines' CD organizations created an electronic survey that CDs received in 2006-2007. More than 500 CDs responded, including 71 surgeons. Surgeons reported spending approximately 27% of professional time on education. Most have codirectors, so total CD effort approximates the greater than 50% Alliance for Clinical Education guidelines. No disciplines' CDs have more than one support staff as recommended. Surgeons have the least clinic time, but the most inpatient weeks and many publications. Surgery CD concerns are curricula and simulation; few believe being a CD impairs academic advancement and more than 95% believe it enhances work satisfaction. Surgery CDs are clinically active and academically productive. Although few surgery CDs have the recommended support staff, more than 95% report being a CD enhances work satisfaction.

Cultivating Fluorescent Flowers with Highly Luminescent Carbon Dots Fabricated by a Double Passivation Method.

PubMed

Han, Shuai; Chang, Tao; Zhao, Haiping; Du, Huanhuan; Liu, Shan; Wu, Baoshuang; Qin, Shenjun

2017-07-07

In this work, we present the fabrication of highly luminescent carbon dots (CDs) by a double passivation method with the assistance of Ca(OH)₂. In the reaction process, Ca 2+ protects the active functional groups from overconsumption during dehydration and carbonization, and the electron-withdrawing groups on the CD surface are converted to electron-donating groups by the hydroxyl ions. As a result, the fluorescence quantum yield of the CDs was found to increase with increasing Ca(OH)₂ content in the reaction process. A blue-shift optical spectrum of the CDs was also found with increasing Ca(OH)₂ content, which could be attributed to the increasing of the energy gaps for the CDs. The highly photoluminescent CDs obtained (quantum yield: 86%) were used to cultivate fluorescent carnations by a water culture method, while the results of fluorescence microscopy analysis indicated that the CDs had entered the plant tissue structure.

Reliability and validity of a Japanese version of the Cambridge depersonalization scale as a screening instrument for depersonalization disorder.

PubMed

Sugiura, Miyuki; Hirosawa, Masataka; Tanaka, Sumio; Nishi, Yasunobu; Yamada, Yasuyuki; Mizuno, Motoki

2009-06-01

The Cambridge Depersonalization Scale (CDS) is an instrument that has obtained reliability and validity in some countries for use in detecting depersonalization disorder under clinical conditions, but not yet in Japan under non-psychiatric conditions. The purposes of this study were to develop a Japanese version of the CDS (J-CDS) and to examine its reliability and validity as an instrument for screening depersonalization disorder under non-clinical conditions. The CDS was translated from English into Japanese and then back-translated into English by a native English-speaking American. After making the J-CDS, we examined its reliability and validity. Questionnaires that were composed of J-CDS, the Dissociative Experience Scale (DES), the Zung self-rating scale and the Maudsley Obsessional-Compulsive Inventory were administrated to 59 participants (12 patients with depersonalization disorder, 11 individuals who had recovered from depersonalization and 36 healthy controls). Cronbach's alpha and split-half reliability were 0.94 and 0.93, respectively. The J-CDS score in the depersonalization group was significantly higher than in the healthy control group. The J-CDS score was significantly correlated with scores of total DES, and DES-depersonalization. The best compromise between the true positive and false negative rate was at a cut-off point of 60, yielding a sensitivity of 1.00 and a specificity of 0.96. In this study, J-CDS showed good reliability and validity. The best cut-off point, when we use this for distinguishing individuals with depersonalization disorder from individuals without psychiatric disorders, is 60 points.

Evaluation of the Effect of Decision Support on the Efficiency of Primary Care Providers in the Outpatient Practice

PubMed Central

Hankey, Ronald A.; Decker, Lindsay K.; Cha, Stephen S.; Greenes, Robert A.; Liu, Hongfang; Chaudhry, Rajeev

2015-01-01

Background: Clinical decision support (CDS) for primary care has been shown to improve delivery of preventive services. However, there is little evidence for efficiency of physicians due to CDS assistance. In this article, we report a pilot study for measuring the impact of CDS on the time spent by physicians for deciding on preventive services and chronic disease management. Methods: We randomly selected 30 patients from a primary care practice, and assigned them to 10 physicians. The physicians were requested to perform chart review to decide on preventive services and chronic disease management for the assigned patients. The patients assignment was done in a randomized crossover design, such that each patient received 2 sets of recommendations—one from a physician with CDS assistance and the other from a different physician without CDS assistance. We compared the physician recommendations made using CDS assistance, with the recommendations made without CDS assistance. Results: The physicians required an average of 1 minute 44 seconds, when they were they had access to the decision support system and 5 minutes when they were unassisted. Hence the CDS assistance resulted in an estimated saving of 3 minutes 16 seconds (65%) of the physicians’ time, which was statistically significant (P < .0001). There was no statistically significant difference in the number of recommendations. Conclusion: Our findings suggest that CDS assistance significantly reduced the time spent by physicians for deciding on preventive services and chronic disease management. The result needs to be confirmed by performing similar studies at other institutions. PMID:25155103

Easy Preparation and Photoelectrochemical Properties of CdS Nanoparticle/Graphene Nanosheet Nanocomposites Using Supercritical Carbon Dioxide.

PubMed

Yan, Shancheng; Xu, Xin; Jiang, Chao; Pan, Lijia; Shi, Yi; Hu, Dong; Cao, Zhenglin

2016-03-01

Graphene nanosheets (GNSs) were modified with CdS nanoparticles (NPs) using supercritical CO2 (SC CO2), which has gas-like diffusivity, low viscosity, and near-zero surface tension. The resulting CdS NP/GNS nanocomposites were characterized by field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, and photoluminescence spectroscopy. Distinct morphologies of CdS NP/GNS nanocomposites decorated on the GNS surface were obtained at different SC CO2 pressures, temperatures, and durations and in different sources. Results showed that the sources and SC CO2 significantly influenced the aggregation or assembly behavior of the CdS NP/GNS nanocomposites on the GNSs. The formation mechanism of the distinct nanohybrid structures was studied by Raman mapping. A difference was noted between the Raman spectra of pristine graphene nanosheets and CdS NP/GNS nanocomposites. This result can be ascribed to the CdS NPs anchored onto the GNS defects and to the improved quality of the GNSs under SC CO2. The photo-current densities of CdS NP/GNS nanocomposites were at least three times higher than that of the pristine CdS NPs at the same applied voltage for photoelectrochemical water splitting. The findings suggested that highly efficient graphene-supported NP photoelectrocatalysts can be fabricated by the supercritical fluid method and that graphene can serve as a favorable photoelectrocatalytic carrier, with promising potential applications in environmental and energy fields. Keywords: Graphene Nanosheets, Cadmium Sulfide, Raman Spectroscopy, Photoelectrochemical.

Clinical Decision Support: a 25 Year Retrospective and a 25 Year Vision

PubMed Central

Sittig, D. F.; Wright, A.

2016-01-01

Summary Objective The objective of this review is to summarize the state of the art of clinical decision support (CDS) circa 1990, review progress in the 25 year interval from that time, and provide a vision of what CDS might look like 25 years hence, or circa 2040. Method Informal review of the medical literature with iterative review and discussion among the authors to arrive at six axes (data, knowledge, inference, architecture and technology, implementation and integration, and users) to frame the review and discussion of selected barriers and facilitators to the effective use of CDS. Result In each of the six axes, significant progress has been made. Key advances in structuring and encoding standardized data with an increased availability of data, development of knowledge bases for CDS, and improvement of capabilities to share knowledge artifacts, explosion of methods analyzing and inferring from clinical data, evolution of information technologies and architectures to facilitate the broad application of CDS, improvement of methods to implement CDS and integrate CDS into the clinical workflow, and increasing sophistication of the end-user, all have played a role in improving the effective use of CDS in healthcare delivery. Conclusion CDS has evolved dramatically over the past 25 years and will likely evolve just as dramatically or more so over the next 25 years. Increasingly, the clinical encounter between a clinician and a patient will be supported by a wide variety of cognitive aides to support diagnosis, treatment, care-coordination, surveillance and prevention, and health maintenance or wellness. PMID:27488402

Optical characterization of CdS nanoparticles embedded into the comb-type amphiphilic graft copolymer

NASA Astrophysics Data System (ADS)

Kalaycı, Özlem A.; Duygulu, Özgür; Hazer, Baki

2013-01-01

This study refers to the synthesis and characterization of a novel organic/inorganic hybrid nanocomposite material containing cadmium sulfide (CdS) nanoparticles. For this purpose, a series of polypropylene (PP)-g-polyethylene glycol (PEG), PP-g-PEG comb-type amphiphilic graft copolymers were synthesized. PEGs with Mn = 400, 2000, 3350, and 8000 Da were used and the graft copolymers obtained were coded as PPEG400, PPEG2000, PPEG3350, and PPEG8000. CdS nanoparticles were formed in tetrahydrofuran solution of PP-g-PEG amphiphilic comb-type copolymer by the reaction between aqueous solutions of Na2S and Cd(CH3COO)2 simultaneously. Micelle formation of PPEG2000 comb-type amphiphilic graft copolymer in both solvent/non-solvent (petroleum ether-THF) by transmission electron microscopy (TEM). The optical characteristics, size morphology, phase analysis, and dispersion of CdS nanoparticles embedded in PPEG400, PPEG2000, PPEG3350, and PPEG8000 comb-type amphiphilic graft copolymer micelles were determined by high resolution TEM (HRTEM), energy dispersive spectroscopy, UV-vis spectroscopy, and fluorescence emission spectroscopy techniques. The aggregate size of PPEG2000-CdS is between 10 and 50 nm; however, in the case of PPEG400-CdS, PPEG3350-CdS, and PPEG8000-CdS samples, it is up to approximately 100 nm. The size of CdS quantum dots in the aggregates for PPEG2000 and PPEG8000 samples was observed as 5 nm by HRTEM analysis, and this result was also supported by UV-vis absorbance spectra and fluorescence emission spectra.

Single-Source Molecular Precursor for Synthesis of CdS Nanoparticles and Nanoflowers

NASA Astrophysics Data System (ADS)

Salavati-Niasari, Masoud; Sobhani, Azam

2012-04-01

CdS Semiconductor nanostructures were synthesized by using two different methods. Using triphenylphosphine (C18H15P) and oleylamine (C18H37N) as surfactant, CdS semiconductor nanocrystals with a size ranging from 30 to 90 nm can be synthesized by thermal decomposition of precursor [bis(thiosemicarbazide)cadmium(II)]. CdS nanoflowers were synthesized via hydrothermal decomposition of [bis(thiosemicarbazide) cadmium(II)] without any surfactant. X-ray diffraction (XRD) patterns confirm that the resulting samples were a pure hexagonal phase of CdS. The optical property test indicates that the absorption peak of the samples shifts towards short wavelength, and the blue shift phenomenon might be ascribed to the quantum effect.

Facile synthesis of carbon dots with superior sensing ability

NASA Astrophysics Data System (ADS)

Jin, Lin; Li, Jingguo; Liu, Liyun; Wang, Zhenling; Zhang, Xingcai

2018-04-01

Carbon dots (CDs) have various applications in biomedical and environmental field, such as bio-imaging, bio-sensing and heavy metal detection. In this study, a novel class of CDs were synthesized using a one-step hydrothermal method. The fabricated CDs displayed stable photoluminescence, good water solubility, and photo stability. Moreover, the functional groups (carboxylic acid moieties and hydroxyls) on the surface of the obtained CDs enable it with superior sensing ability (e.g., very low detectable concentration for Pb2+: 5 nmol/L). With superior detection sensitivity, excellent fluorescent properties and facile fabrication method, the as-obtained CDs can find practical applications as cost-effective and sensitive chemo-sensors in water and food safety field.

CDS Re Mix

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

CDS (Change Detection Systems) is a mechanism for rapid visual analysis using complex image alignment algorithms. CDS is controlled with a simple interface that has been designed for use for anyone that can operate a digital camera. A challenge of complex industrial systems like nuclear power plants is to accurately identify changes in systems, structures and components that may critically impact the operation of the facility. CDS can provide a means of early intervention before the issues evolve into safety and production challenges.

Improved Dynamic Modeling of the Cascade Distillation Subsystem and Analysis of Factors Affecting Its Performance

NASA Technical Reports Server (NTRS)

Perry, Bruce A.; Anderson, Molly S.

2015-01-01

The Cascade Distillation Subsystem (CDS) is a rotary multistage distiller being developed to serve as the primary processor for wastewater recovery during long-duration space missions. The CDS could be integrated with a system similar to the International Space Station Water Processor Assembly to form a complete water recovery system for future missions. A preliminary chemical process simulation was previously developed using Aspen Custom Modeler® (ACM), but it could not simulate thermal startup and lacked detailed analysis of several key internal processes, including heat transfer between stages. This paper describes modifications to the ACM simulation of the CDS that improve its capabilities and the accuracy of its predictions. Notably, the modified version can be used to model thermal startup and predicts the total energy consumption of the CDS. The simulation has been validated for both NaC1 solution and pretreated urine feeds and no longer requires retuning when operating parameters change. The simulation was also used to predict how internal processes and operating conditions of the CDS affect its performance. In particular, it is shown that the coefficient of performance of the thermoelectric heat pump used to provide heating and cooling for the CDS is the largest factor in determining CDS efficiency. Intrastage heat transfer affects CDS performance indirectly through effects on the coefficient of performance.

Carbon dots-decorated multiwalled carbon nanotubes nanocomposites as a high-performance electrochemical sensor for detection of H2O2 in living cells.

PubMed

Bai, Jing; Sun, Chunhe; Jiang, Xiue

2016-07-01

A novel enzyme-free hydrogen peroxide sensor composed of carbon dots (CDs) and multi-walled carbon nanotubes (MWCNTs) was prepared. It was found that the carbon dots-decorated multi-walled carbon nanotubes nanocomposites (CDs/MWCNTs) modified glassy carbon (GC) electrode (CDs/MWCNTs/GCE) exhibited a significant synergistic electrocatalytic activity towards hydrogen peroxide reduction as compared to carbon dots or multi-walled carbon nanotubes alone, and the CDs/MWCNTs/GCE has shown a low detection limit as well as excellent stability, selectivity, and reproducibility. These remarkable analytical advantages enable the practical application of CDs/MWCNTs/GCE for the real-time tracking of hydrogen peroxide (H2O2) released from human cervical cancer cells with satisfactory results. The enhanced electrochemical activity can be assigned to the edge plane-like defective sites and lattice oxygen in the CDs/MWCNTs nanocomposites due to the small amount of decoration of carbon dots on the multi-walled carbon nanotubes. Based on a facile preparation method and with good electrochemical properties, the CDs/MWCNTs nanocomposites represent a new class of carbon electrode for electrochemical sensor applications. Graphical Abstract CDs/MWCNTs exhibited good electrocatalytic activity and stability to H2O2 reduction and can be used for real-time detection of H2O2 released from living cells.

One-pot synthesis and lubricity of fluorescent carbon dots applied on PCL-PEG-PCL hydrogel.

PubMed

Guo, Junde; Mei, Tangjie; Li, Yue; Hafezi, Mahshid; Lu, Hailin; Li, Jianhui; Dong, Guangneng

2018-06-12

This work presents a method for one-pot synthesis of N-doped nanometer-size carbon dots, which can be assembled with thermosensitive poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) (PCL-PEG-PCL, PCEC) hydrogel to achieve slow-release lubricity. The typical property of this green production was studied by fourier transform infrared (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscope (TEM). The photoluminescence of composite PCEC/CDs hydrogel and its released solutions were characterized by ultraviolet spectrum, and the rheological properties were tested by rotary rheometer. Tribological performance of the released solution from composite PCEC/CDs hydrogel was obtained to compare with PBS and pure CDs solution. The experimental results reveal that the CDs contain the chemical groups of N-H, C-OH/C-O-C and -COOH, etc. In addition, the diameter of the CDs is in the range of 6~8 nm. The phase transition behavior of PCEC/CDs hydrogel can be still kept and its viscoelasticity hydrogel is improved by approximatively 7%. Furthermore, friction coefficient of the released solution from composite PCEC/CDs hydrogel decreases by about 70% than that of PBS. Besides, the wear condition can be improved by a lubricating transfer film formed by released CDs. This novel strategy for slow-release application is valuable for drug delivery and bio-tribology.

Effect of preparation methods and doping on the structural and tunable emissions of CdS

NASA Astrophysics Data System (ADS)

Mohamed, Mohamed Bakr; Abdel-Kader, M. H.; Alhazime, Ali A.; Almarashi, Jamal Q. M.

2018-03-01

Fe, Mn and Mg doped CdS samples were prepared by thermolysis method in air and under flow of nitrogen. Structural, compositional and optical properties of the prepared samples were investigated using x-ray powder diffraction (XRD), scanning electron microscope (SEM/EDS mapping), Fourier transform infrared red (FTIR), UV-vis absorption and photoluminescence (PL) spectroscopes. Rietveld refinement of x-ray data showed that all the undoped and doped CdS samples prepared in air and under flow of nitrogen have both cubic and hexagonal structures. The percentages of hexagonal and cubic phases for all prepared samples were determined. The crystallite size increased for CdS prepared under flow of N2 compared with the sample prepared in air. The energy gap of all the samples was calculated using UV data. The intensity of PL emission changed according to the method of preparation and the kind of doping elements. PL emission revealed a blue shift for CdS prepared in air compared with CdS prepared under flow of nitrogen; also all doped samples showed a red shift of PL spectra compared with undoped samples. Undoped and doped CdS with Fe and Mg samples emitted violet and blue sub-spectra. Mn doped CdS prepared in air revealed violet, blue and yellow sub-spectra, while the sample prepared under flow of N2 emitted violet, blue and green sub-spectra.

Publication, discovery and interoperability of Clinical Decision Support Systems: A Linked Data approach.

PubMed

Marco-Ruiz, Luis; Pedrinaci, Carlos; Maldonado, J A; Panziera, Luca; Chen, Rong; Bellika, J Gustav

2016-08-01

The high costs involved in the development of Clinical Decision Support Systems (CDSS) make it necessary to share their functionality across different systems and organizations. Service Oriented Architectures (SOA) have been proposed to allow reusing CDSS by encapsulating them in a Web service. However, strong barriers in sharing CDS functionality are still present as a consequence of lack of expressiveness of services' interfaces. Linked Services are the evolution of the Semantic Web Services paradigm to process Linked Data. They aim to provide semantic descriptions over SOA implementations to overcome the limitations derived from the syntactic nature of Web services technologies. To facilitate the publication, discovery and interoperability of CDS services by evolving them into Linked Services that expose their interfaces as Linked Data. We developed methods and models to enhance CDS SOA as Linked Services that define a rich semantic layer based on machine interpretable ontologies that powers their interoperability and reuse. These ontologies provided unambiguous descriptions of CDS services properties to expose them to the Web of Data. We developed models compliant with Linked Data principles to create a semantic representation of the components that compose CDS services. To evaluate our approach we implemented a set of CDS Linked Services using a Web service definition ontology. The definitions of Web services were linked to the models developed in order to attach unambiguous semantics to the service components. All models were bound to SNOMED-CT and public ontologies (e.g. Dublin Core) in order to count on a lingua franca to explore them. Discovery and analysis of CDS services based on machine interpretable models was performed reasoning over the ontologies built. Linked Services can be used effectively to expose CDS services to the Web of Data by building on current CDS standards. This allows building shared Linked Knowledge Bases to provide machine interpretable semantics to the CDS service description alleviating the challenges on interoperability and reuse. Linked Services allow for building 'digital libraries' of distributed CDS services that can be hosted and maintained in different organizations. Copyright © 2016 Elsevier Inc. All rights reserved.

A combined paging alert and web-based instrument alters clinician behavior and shortens hospital length of stay in acute pancreatitis.

PubMed

Dimagno, Matthew J; Wamsteker, Erik-Jan; Rizk, Rafat S; Spaete, Joshua P; Gupta, Suraj; Sahay, Tanya; Costanzo, Jeffrey; Inadomi, John M; Napolitano, Lena M; Hyzy, Robert C; Desmond, Jeff S

2014-03-01

There are many published clinical guidelines for acute pancreatitis (AP). Implementation of these recommendations is variable. We hypothesized that a clinical decision support (CDS) tool would change clinician behavior and shorten hospital length of stay (LOS). Observational study, entitled, The AP Early Response (TAPER) Project. Tertiary center emergency department (ED) and hospital. Two consecutive samplings of patients having ICD-9 code (577.0) for AP were generated from the emergency department (ED) or hospital admissions. Diagnosis of AP was based on conventional Atlanta criteria. The Pre-TAPER-CDS-Tool group (5/30/06-6/22/07) had 110 patients presenting to the ED with AP per 976 ICD-9 (577.0) codes and the Post-TAPER-CDS-Tool group (5/30/06-6/22/07) had 113 per 907 ICD-9 codes (7/14/10-5/5/11). The TAPER-CDS-Tool, developed 12/2008-7/14/2010, is a combined early, automated paging-alert system, which text pages ED clinicians about a patient with AP and an intuitive web-based point-of-care instrument, consisting of seven early management recommendations. The pre- vs. post-TAPER-CDS-Tool groups had similar baseline characteristics. The post-TAPER-CDS-Tool group met two management goals more frequently than the pre-TAPER-CDS-Tool group: risk stratification (P<0.0001) and intravenous fluids >6L/1st 0-24 h (P=0.0003). Mean (s.d.) hospital LOS was significantly shorter in the post-TAPER-CDS-Tool group (4.6 (3.1) vs. 6.7 (7.0) days, P=0.0126). Multivariate analysis identified four independent variables for hospital LOS: the TAPER-CDS-Tool associated with shorter LOS (P=0.0049) and three variables associated with longer LOS: Japanese severity score (P=0.0361), persistent organ failure (P=0.0088), and local pancreatic complications (<0.0001). The TAPER-CDS-Tool is associated with changed clinician behavior and shortened hospital LOS, which has significant financial implications.

Combination of counterpropagation artificial neural networks and antioxidant activities for comprehensive evaluation of associated-extraction efficiency of various cyclodextrins in the traditional Chinese formula Xue-Zhi-Ning.

PubMed

Sun, Lili; Yang, Jianwen; Wang, Meng; Zhang, Huijie; Liu, Yanan; Ren, Xiaoliang; Qi, Aidi

2015-11-10

Xue-Zhi-Ning (XZN) is a widely used traditional Chinese medicine formula to treat hyperlipidemia. Recently, cyclodextrins (CDs) have been extensively used to minimize problems relative to medicine bioavailability, such as low solubility and poor stability. The objective of this study was to determine the associated-extraction efficiency of various CDs in XZN. Three various type CDs were evaluated, including native CDs (α-CD, β-CD), hydrophilic CD derivatives (HP-β-CD and Me-β-CD), and ionic CD derivatives (SBE-β-CD and CM-β-CD). An ultra high-performance liquid chromatography (UHPLC) fingerprint was applied to determine the components in CD extracts and original aqueous extract (OAE). A counterpropagation artificial neural network (CP-ANN) was used to analyze the components in different extracts and compare the selective extraction of various CDs. Extraction efficiencies of the various CDs in terms of extracted components follow the ranking, ionic CD derivatives>hydrophilic CD derivatives>native CDs>OAE. Besides, different types of CDs have their own selective extraction and ionic CD derivatives present the strongest associated-extraction efficiency. Antioxidant potentials of various extracts were evaluated by determining the inhibition of spontaneous, H2O2-induced, CCl4-induced and Fe(2+)/ascorbic acid-induced lipid peroxidation (LPO) and analyzing the scavenging capacity for DPPH and hydroxyl radicals. The order of extraction efficiencies of the various CDs relative to antioxidant activities is as follows: SBE-β-CD>CM-β-CD>HP-β-CD>Me-β-CD>β-CD>α-CD. It can be demonstrated that all of the CDs studied increase the extraction efficiency and that ionic CD derivatives (SBE-β-CD and CM-β-CD) present the highest extraction capability in terms of amount extracted and antioxidant activities of extracts. Copyright © 2015 Elsevier B.V. All rights reserved.

Boosting Quality Registries with Clinical Decision Support Functionality*. User Acceptance of a Prototype Applied to HIV/TB Drug Therapy.

PubMed

Wannheden, Carolina; Hvitfeldt-Forsberg, Helena; Eftimovska, Elena; Westling, Katarina; Ellenius, Johan

2017-08-11

The care of HIV-related tuberculosis (HIV/TB) is complex and challenging. Clinical decision support (CDS) systems can contribute to improve quality of care, but more knowledge is needed on factors determining user acceptance of CDS. To analyze physicians' and nurses' acceptance of a CDS prototype for evidence-based drug therapy recommendations for HIV/TB treatment. Physicians and nurses were involved in designing a CDS prototype intended for future integration with the Swedish national HIV quality registry. Focus group evaluation was performed with ten nurses and four physicians, respectively. The Unified Theory of Acceptance and Use of Technology (UTAUT) was used to analyze acceptance. We identified several potential benefits with the CDS prototype as well as some concerns that could be addressed by redesign. There was also concern about dependence on physician attitudes, as well as technical, organizational, and legal issues. Acceptance evaluation at a prototype stage provided rich data to improve the future design of a CDS prototype. Apart from design and development efforts, substantial organizational efforts are needed to enable the implementation and maintenance of a future CDS system.

Nitrogen and Phosphorus Co-Doped Carbon Nanodots as a Novel Fluorescent Probe for Highly Sensitive Detection of Fe(3+) in Human Serum and Living Cells.

PubMed

Shi, Bingfang; Su, Yubin; Zhang, Liangliang; Huang, Mengjiao; Liu, Rongjun; Zhao, Shulin

2016-05-04

Chemical doping with heteroatoms can effectively modulate physicochemical and photochemical properties of carbon dots (CDs). However, the development of multi heteroatoms codoped carbon nanodots is still in its early stage. In this work, a facile hydrothermal synthesis strategy was applied to synthesize multi heteroatoms (nitrogen and phosphorus) codoped carbon nanodots (N,P-CDs) using glucose as carbon source, and ammonia, phosphoric acid as dopant, respectively. Compared with CDs, the multi heteroatoms doped CDs resulted in dramatic improvement in the electronic characteristics and surface chemical activities. Therefore, the N,P-CDs prepared as described above exhibited a strong blue emission and a sensitive response to Fe(3+). The N,P-CDs based fluorescent sensor was then applied to sensitively determine Fe(3+) with a detection limit of 1.8 nM. Notably, the prepared N,P-CDs possessed negligible cytotoxicity, excellent biocompatibility, and high photostability. It was also applied for label-free detection of Fe(3+) in complex biological samples and the fluorescence imaging of intracellular Fe(3+), which indicated its potential applications in clinical diagnosis and other biologically related study.

Morphology, structure and optical properties of hydrothermally synthesized CeO2/CdS nanocomposites

NASA Astrophysics Data System (ADS)

Mohanty, Biswajyoti; Nayak, J.

2018-04-01

CeO2/CdS nanocomposites were synthesized using a two-step hydrothermal technique. The effects of precursor concentration on the optical and structural properties of the CeO2/CdS nanoparticles were systematically studied. The morphology, composition and the structure of the CeO2/CdS nanocomposite powder were studied by scanning electron microscopy (SEM), energy dispersive X-ray spectrum analysis (EDXA) and X-ray diffraction (XRD), respectively. The optical properties of CeO2/CdS nanocomposites were studied by UV-vis absorption and photoluminescence (PL) spectroscopy. The optical band gaps of the CeO2/CdS nanopowders ranged from 2.34 eV to 2.39 eV as estimated from the UV-vis absorption. In the room temperature photoluminescence spectrum of CeO2/CdS nanopowder, a strong blue emission band was observed at 400 nm. Since the powder shows strong visible luminescence, it may be used as a blue phosphor in future. The original article published with this DOI was submitted in error. The correct article was inadvertently left out of the original submission. This has been rectified and the correct article was published online on 16 April 2018.

Ratiometric, visual, dual-signal fluorescent sensing and imaging of pH/copper ions in real samples based on carbon dots-fluorescein isothiocyanate composites.

PubMed

Zhu, Xinxin; Jin, Hui; Gao, Cuili; Gui, Rijun; Wang, Zonghua

2017-01-01

In this article, a facile aqueous synthesis of carbon dots (CDs) was developed by using natural kelp as a new carbon source. Through hydrothermal carbonization of kelp juice, fluorescent CDs were prepared and the CDs' surface was modified with polyethylenimine (PEI). The PEI-modified CDs were conjugated with fluorescein isothiocyanate (FITC) to fabricate CDs-FITC composites. To exploit broad applications, the CDs-FITC composites were developed as fluorescent sensing or imaging platforms of pH and Cu 2+ . Analytical performances of the composites-based fluorescence (FL) sensors were evaluated, including visual FL imaging of pH in glass bottle, ratiometric FL sensing of pH in yogurt samples, visual FL latent fingerprint and leaf imaging detection of [Cu 2+ ], dual-signal FL sensing of [Cu 2+ ] in yogurt and human serum samples. Experimental results from ratiometric, visual, dual-signal FL sensing and imaging applications confirmed the high feasibility, accuracy, stabilization and simplicity of CDs-FITC composites-based FL sensors for the detection of pH and Cu 2+ ions in real samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Quantum dots coupled ZnO nanowire-array panels and their photocatalytic activities.

PubMed

Liao, Yulong; Que, Wenxiu; Zhang, Jin; Zhong, Peng; Yuan, Yuan; Qiu, Xinku; Shen, Fengyu

2013-02-01

Fabrication and characterization of a heterojunction structured by CdS quantum dots@ZnO nanowire-array panels were presented. Firstly, ZnO nanowire-array panels were prepared by using a chemical bath deposition approach where wurtzite ZnO nanowires with a diameter of about 100 nm and 3 microm in length grew perpendicularly to glass substrate. Secondly, CdS quantum dots were deposited onto the surface of the ZnO nanowire-arrays by using successive ion layer absorption and reaction method, and the CdS shell/ZnO core heterojunction were thus obtained. Field emission scanning electron microscopy and transmission electron microscope were employed to characterize the morphological properties of the as-obtained CdS quantum dots@ZnO nanowire-array panels. X-ray diffraction was adopted to characterize the crystalline properties of the as-obtained CdS quantum dots@ZnO nanowire-array panels. Methyl orange was taken as a model compound to confirm the photocatalytic activities of the CdS shell/ZnO core heterojunction. Results indicate that CdS with narrow band gap not only acts as a visible-light sensitizer but also is responsible for an effective charge separation.

Enhanced photocatalytic activity of graphitic carbon nitride/cadmium sulfide heterojunctions by protonating treatment

NASA Astrophysics Data System (ADS)

Yan, Mengdie; Ma, Yushuang; Zhang, Huanhuan; Ye, Boyong; Dong, Xiaoping

2018-05-01

Highly efficient visible-light-driven protonated g-C3N4 (pg-C3N4)/CdS heterojunctions with different weight ratios of CdS were prepared by treating g-C3N4 with hydrochloric acid and using an in-situ precipitation method. The structure and morphology of heterojunctions were investigated by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR) and nitrogen adsorption technology. The as-prepared pg-C3N4/CdS heterojunction with 50 wt% of g-C3N4 exhibited much higher photocatalytic activity for photodegradation of methyl orange (MO) than pg-C3N4, CdS and g-C3N4/CdS without protonation as well, which could be contributed to the activation of hydrochloric acid treatment and the improved electron-hole separation due to their overlapping band structure of CdS and pg-C3N4. A possible photocatalytic mechanism of the pg-C3N4/CdS heterojunctions with superoxide radical species as the main active species in photocatalysis was proposed on the basis of experimental results.

Local Swift-BAT active galactic nuclei prefer circumnuclear star formation

NASA Astrophysics Data System (ADS)

Lutz, D.; Shimizu, T.; Davies, R. I.; Herrera-Camus, R.; Sturm, E.; Tacconi, L. J.; Veilleux, S.

2018-01-01

We use Herschel data to analyze the size of the far-infrared 70 μm emission for z < 0.06 local samples of 277 hosts of Swift-BAT selected active galactic nuclei (AGN), and 515 comparison galaxies that are not detected by BAT. For modest far-infrared luminosities 8.5 10.5 (star formation rates ≳6 M⊙ yr-1), possibly because these are typically reached in more compact regions. Full Table A.1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/609/A9

PVP capped CdS nanoparticles for UV-LED applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sivaram, H.; Selvakumar, D.; Jayavel, R., E-mail: rjvel@annauniv.edu

Polyvinlypyrrolidone (PVP) capped cadmium sulphide (CdS) nanoparticles are synthesized by wet chemical method. The powder X-ray diffraction (XRD) result indicates that the nanoparticles are crystallized in cubic phase. The optical properties are characterized by UV-Vis absorption. The morphology of CdS nanoparticles are studied using Scanning electron microscope (SEM). The thermal behavior of the as prepared nanoparticles has been examined by Thermo gravimetric analysis (TGA). The optical absorption study of pvp capped CdS reveal a red shift confirms the UV-LED applications.

Health Care Expenditures and Utilization for Children With Noncomplex Chronic Disease.

PubMed

Hoefgen, Erik R; Andrews, Annie L; Richardson, Troy; Hall, Matthew; Neff, John M; Macy, Michelle L; Bettenhausen, Jessica L; Shah, Samir S; Auger, Katherine A

2017-09-01

Pediatric health care expenditures and use vary by level of complexity and chronic illness. We sought to determine expenditures and use for children with noncomplex chronic diseases (NC-CDs). We performed a retrospective, cross-sectional analysis of Medicaid enrollees (ages 0-18 years) from January 1, 2012, through December 31, 2013, using administrative claims (the Truven MarketScan Medicaid Database). Patients were categorized by chronicity of illness by using 3M Health Information System's Clinical Risk Groups (CRGs) as follows: without chronic diseases (WO-CDs) (CRG 1-2), NC-CDs (CRG 3-5), and complex chronic diseases (C-CDs) (CRG 6-9). Primary outcomes were medical expenditures, including total annualized population expenditure and per-member per-year expenditure (PMPY). Secondary outcomes included the number of health care encounters over the 2-year period. There were 2 424 946 children who met inclusion criteria, 53% were WO-CD; 36% had an NC-CD; and 11% had a C-CD. Children with NC-CDs accounted for 33% ($2801 PMPY) of the annual spending compared with 20% ($1151 PMPY) accounted for by children WO-CDs and 47% ($12 569 PMPY) by children with C-CDs. The median outpatient visit count by group over the 2-year period was 15 (interquartile range [IQR] 10-25) for NC-CD, 8 (IQR 5-13) WO-CD, and 34 (IQR 19-72) for C-CD. Children with NC-CDs accounted for 33% of pediatric Medicaid expenditures and have significantly higher PMPY and aggregate annual expenditures than children WO-CDs. The annual aggregate expenditures of the NC-CD group represent a significant societal cost because of the high volume of children, extrapolated to ∼$34.9 billion annually in national Medicaid expenditures. Copyright © 2017 by the American Academy of Pediatrics.

Expressing clinical data sets with openEHR archetypes: a solid basis for ubiquitous computing.

PubMed

Garde, Sebastian; Hovenga, Evelyn; Buck, Jasmin; Knaup, Petra

2007-12-01

The purpose of this paper is to analyse the feasibility and usefulness of expressing clinical data sets (CDSs) as openEHR archetypes. For this, we present an approach to transform CDS into archetypes, and outline typical problems with CDS and analyse whether some of these problems can be overcome by the use of archetypes. Literature review and analysis of a selection of existing Australian, German, other European and international CDSs; transfer of a CDS for Paediatric Oncology into openEHR archetypes; implementation of CDSs in application systems. To explore the feasibility of expressing CDS as archetypes an approach to transform existing CDSs into archetypes is presented in this paper. In case of the Paediatric Oncology CDS (which consists of 260 data items) this lead to the definition of 48 openEHR archetypes. To analyse the usefulness of expressing CDS as archetypes, we identified nine problems with CDS that currently remain unsolved without a common model underpinning the CDS. Typical problems include incompatible basic data types and overlapping and incompatible definitions of clinical content. A solution to most of these problems based on openEHR archetypes is motivated. With regard to integrity constraints, further research is required. While openEHR cannot overcome all barriers to Ubiquitous Computing, it can provide the common basis for ubiquitous presence of meaningful and computer-processable knowledge and information, which we believe is a basic requirement for Ubiquitous Computing. Expressing CDSs as openEHR archetypes is feasible and advantageous as it fosters semantic interoperability, supports ubiquitous computing, and helps to develop archetypes that are arguably of better quality than the original CDS.

Exciton-Plasmon Interaction between AuNPs/Graphene Nanohybrids and CdS Quantum Dots/TiO2 for Photoelectrochemical Aptasensing of Prostate-Specific Antigen.

PubMed

Cai, Guoneng; Yu, Zhengzhong; Ren, Rongrong; Tang, Dianping

2018-03-23

A competitive-displacement reaction strategy based on target-induced dissociation of gold nanoparticle coated graphene nanosheet (AuNPs/GN) from CdS quantum dot functionalized mesoporous titanium dioxide (CdS QDs/TiO 2 ) was designed for the sensitive photoelectrochemical (PEC) aptasensing of prostate-specific antigen (PSA) through the exciton-plasmon interaction (EPI) between CdS QDs and AuNPs. To construct such an aptasensing system, capture DNA was initially conjugated covalently onto CdS QDs/TiO 2 -modified electrode, and then AuNPs/GN-labeled PSA aptamer was bound onto biofunctionalized CdS QDs/TiO 2 via hybridization chain reaction of partial bases with capture DNA. Introduction of AuNPs/GN efficiently quenched the photocurrent of CdS QDs/TiO 2 thanks to energy transfer. Upon addition of target PSA, the sandwiched aptamer between CdS QDs/TiO 2 and AuNPs/GN reacted with the analyte analyte, thus resulting in the dissociation of AuNPs/GN from the CdS QDs/TiO 2 to increase the photocurrent. Under optimum conditions, the aptasensing platform exhibited a high sensitivity for PSA detection within a dynamic linear range of 1.0 pg/mL to 8.0 ng/mL at a low limitat of detection of 0.52 pg/mL. The interparticle distance of exciton-plasmon interaction and contents of AuNPs corresponding to EPI effect in this system were also studied. Good selectivity and high reproducibility were obtained for the analysis of target PSA. Importantly, the accuracy and matrix effect of PEC aptasensor was evaluated for the determination of human serum specimens and newborn calf serum-diluted PSA standards, giving a well-matched result with the referenced PSA ELISA kit.

Amorphous MoS{sub x} on CdS nanorods for highly efficient photocatalytic hydrogen evolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Xiaofang; Tang, Chaowan; Zheng, Qun

Loading cocatalyst on semiconductors was crucially necessary for improving the photocatalytic hydrogen evolution. Amorphous MoS{sub x} as a novel and noble metal-free cocatalyst was loaded on CdS nanorods by a simple photodeposition method. Efficient hydrogen evolution with amount of 15 mmol h{sup −1} g{sup −1} was observed over the MoS{sub x} modified CdS nanorods, which was about 6 times higher than that by using Pt as cocatalyst. Meanwhile, with MoS{sub x} cocatalyst, the efficiency of CdS nanorods was superior to that of CdS nanoparticles and bulk CdS. No deactivation could be observed in the efficiency of MoS{sub x} modified CdSmore » nanorods under irradiation for successive 10 h. Further experimental results indicated that the efficient electrons transfer, low overpotential of hydrogen evolution and active S atoms over the MoS{sub x} modified CdS nanorods were responsible for the higher efficiency. Our results provided guidance for synthesizing noble metal-free materials as cocatalyst for photocatalytic hydrogen evolution. - Graphical abstract: Photodeposition of amorphous MoS{sub x} on CdS nanorods for highly efficient photocatalytic hydrogen evolution. - Highlights: • Amorphous MoSx cocatalyst was loaded on CdS NRs by a simple photodeposition. • MoS{sub x}/CdS NRs exhibited 6 times higher hydrogen evolution efficiency than Pt/CdS NRs. • The hydrogen evolution of MoS{sub x}/CdS NRs linearly increased with prolonging time. • Lower overpotential and efficient electron transfer were observed over MoS{sub x}/CdS NRs.« less

Development and evaluation of a comprehensive clinical decision support taxonomy: comparison of front-end tools in commercial and internally developed electronic health record systems

PubMed Central

Sittig, Dean F; Ash, Joan S; Feblowitz, Joshua; Meltzer, Seth; McMullen, Carmit; Guappone, Ken; Carpenter, Jim; Richardson, Joshua; Simonaitis, Linas; Evans, R Scott; Nichol, W Paul; Middleton, Blackford

2011-01-01

Background Clinical decision support (CDS) is a valuable tool for improving healthcare quality and lowering costs. However, there is no comprehensive taxonomy of types of CDS and there has been limited research on the availability of various CDS tools across current electronic health record (EHR) systems. Objective To develop and validate a taxonomy of front-end CDS tools and to assess support for these tools in major commercial and internally developed EHRs. Study design and methods We used a modified Delphi approach with a panel of 11 decision support experts to develop a taxonomy of 53 front-end CDS tools. Based on this taxonomy, a survey on CDS tools was sent to a purposive sample of commercial EHR vendors (n=9) and leading healthcare institutions with internally developed state-of-the-art EHRs (n=4). Results Responses were received from all healthcare institutions and 7 of 9 EHR vendors (response rate: 85%). All 53 types of CDS tools identified in the taxonomy were found in at least one surveyed EHR system, but only 8 functions were present in all EHRs. Medication dosing support and order facilitators were the most commonly available classes of decision support, while expert systems (eg, diagnostic decision support, ventilator management suggestions) were the least common. Conclusion We developed and validated a comprehensive taxonomy of front-end CDS tools. A subsequent survey of commercial EHR vendors and leading healthcare institutions revealed a small core set of common CDS tools, but identified significant variability in the remainder of clinical decision support content. PMID:21415065

Photocatalyst based on TiO2 nanotube arrays co-decorated with CdS quantum dots and reduced graphene oxide irradiated by γ rays for effective degradation of ethylene

NASA Astrophysics Data System (ADS)

Zhang, Quan; Ye, Shengying; Song, Xianliang; Luo, Shucan

2018-06-01

We report herein a means of transforming TiO2 nanotube arrays (TNAs) from an amorphous state to an anatase crystal state (denoted as ∗TNAs), and present a single-step synthetic route for preparing CdS quantum dots (CdS QDs) as well as reduced graphene oxide (rGO) through gamma-ray irradiation. The as-prepared ∗TNAs, CdS QDs, and rGO, which had all been subjected to gamma-ray irradiation, were then assembled together to produce the desired heterojunction (denoted as CdS QDs/rGO-∗TNAs). X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), ultraviolet/visible diffuse-reflectance spectroscopy (UV/Vis DRS), Fourier-transform infrared spectroscopy (FTIR), micro-Raman spectrometry (RS), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) have been applied to characterize the appearance and performance of this photocatalyst. The photocatalytic activity of CdS QDs/rGO-∗TNAs towards ethylene degradation has been measured by placing it in a simulated cold-storage environment, the temperature and humidity of which were set at about 3 ± 1 °C and 75-90%, respectively. The results showed that the rate constant (K) of ethylene degradation could reach up to 1.07 × 10-3 min-1 with CdS QDs/rGO-∗TNAs, as compared to 2.30 × 10-4 min-1 with ∗TNAs and 6.25 × 10-4 min-1 with CdS QDs-∗TNAs, indicating that the constructed CdS QDs/rGO-∗TNAs constitutes a promising photocatalyst for ethylene removal in a cold storage environment.

Scalable alignment of CdS nanowires based on efficient roll-on transfer technique.

PubMed

Yan, Shancheng; Shi, Yi; Xiao, Zhongdang; Wang, Junzhuan; Hu, Dong; Xul, Xin; Lu, Tao; Liu, Aili; Gao, Fan

2013-06-01

A roll-on transfer strategy is developed to enable large-scale and uniform assembly of CdS nanowires on various rigid and flexible substrate materials. In this method, the CdS nanowires were synthesized by the hydrothermal method. The dispersed CdS NWs could be firstly aligned and selectively deposited at the micro/nanochannels between aligned nanofibers on the surface of the donor roller as a result of evaporation-induced flow and capillary action, and then the directional and aligned transfer of the CdS NWs from the donor roller to a receiver substrate via roll-on transfer technique. Finally, a device structures consisting of the nanowire channel and two metal electrodes was fabricated. The electrical property of this device was observed.

One-step, low-temperature fabrication of CdS quantum dots by watermelon rind: a green approach

PubMed Central

Lakshmipathy, Rajasekhar; Sarada, Nallani Chakravarthula; Chidambaram, K; Pasha, Sk Khadeer

2015-01-01

We investigated the one-step synthesis of CdS nanoparticles via green synthesis that used aqueous extract of watermelon rind as a capping and stabilizing agent. Preliminary phytochemical analysis depicted the presence of carbohydrates which can act as capping and stabilizing agents. Synthesized CdS nanoparticles were characterized using UV-visible, Fourier transform infrared spectroscopy, X-ray diffraction, EDX, dynamic light scattering, transmission electron microscopy, and atomic force microscopy techniques. The CdS nanoparticles were found to be size- and shape-controlled and were stable even after 3 months of synthesis. The results suggest that watermelon rind, an agro-waste, can be used for synthesis of CdS nanoparticles without any addition of stabilizing and capping agents. PMID:26491319

Enhanced photoelectrochemical properties of TiO2 nanorod arrays decorated with CdS nanoparticles

PubMed Central

Xie, Zheng; Liu, Xiangxuan; Wang, Weipeng; Liu, Can; Li, Zhengcao; Zhang, Zhengjun

2014-01-01

TiO2 nanorod arrays (TiO2 NRAs) sensitized with CdS nanoparticles were fabricated via successive ion layer adsorption and reaction (SILAR), and TiO2 NRAs were obtained by oxidizing Ti NRAs obtained through oblique angle deposition. The TiO2 NRAs decorated with CdS nanoparticles exhibited excellent photoelectrochemical and photocatalytic properties under visible light, and the one decorated with 20 SILAR cycles CdS nanoparticles shows the best performance. This can be attributed to the enhanced separation of electrons and holes by forming heterojunctions of CdS nanoparticles and TiO2 NRAs. This provides a promising way to fabricate the material for solar energy conversion and wastewater degradation. PMID:27877718

Development of a Higher Fidelity Model for the Cascade Distillation Subsystem (CDS)

NASA Technical Reports Server (NTRS)

Perry, Bruce; Anderson, Molly

2014-01-01

Significant improvements have been made to the ACM model of the CDS, enabling accurate predictions of dynamic operations with fewer assumptions. The model has been utilized to predict how CDS performance would be impacted by changing operating parameters, revealing performance trade-offs and possibilities for improvement. CDS efficiency is driven by the THP coefficient of performance, which in turn is dependent on heat transfer within the system. Based on the remaining limitations of the simulation, priorities for further model development include: center dot Relaxing the assumption of total condensation center dot Incorporating dynamic simulation capability for the buildup of dissolved inert gasses in condensers center dot Examining CDS operation with more complex feeds center dot Extending heat transfer analysis to all surfaces

Structural and photoluminescence properties of Ni doped CdS nanoparticles synthesis by sol gel method

NASA Astrophysics Data System (ADS)

Mahdi, Hadeel Salih; Parveen, Azra; Azam, Ameer

2018-05-01

Ni doped CdS nanoparticles have been successfully synthesized by sol-gel method. Nickel nitrate, cadmium nitrate, sodium sulfide has been used as precursors for the preparation of these Ni-doped CdS nanoparticles. The structural properties were studied by X-ray diffraction analysis. Surface morphology and the composition of the samples were studied by scanning electron microscope (SEM). The X-ray diffraction results revealed that the Ni-doped CdS nanoparticles were in hexagonal structure. The crystallite size was determined from Debye-Scherer equation and showed that the particle size increases with the doping of Ni. Optical absorption spectra of Ni doped CdS also was studied by Photoluminescence spectroscopy in the range of 200-600 nm.

Synthesis of Nitrogen and Sulfur Co-doped Carbon Dots from Garlic for Selective Detection of Fe3+

NASA Astrophysics Data System (ADS)

Sun, Chun; Zhang, Yu; Wang, Peng; Yang, Yue; Wang, Yu; Xu, Jian; Wang, Yiding; Yu, William W.

2016-02-01

Garlic was used as a green source to synthesize carbon dots (CDs) with a systematic study of the optical and structure properties. Ethylenediamine was added into the synthesis to improve the photoluminescence quantum yield (PL QY) of the CDs. Detailed structural and composition studies demonstrated that the content of N and the formation of C-N and C=N were critical to improve the PL QY. The as-synthesized CDs exhibited excellent stability in a wide pH range and high NaCl concentrations, rendering them applicable in complicated and harsh conditions. Quenching the fluorescence of the CDs in the presence of Fe3+ ion made these CDs a luminescent probe for selective detection of Fe3+ ion.

Synthesis of Nitrogen and Sulfur Co-doped Carbon Dots from Garlic for Selective Detection of Fe(3.).

PubMed

Sun, Chun; Zhang, Yu; Wang, Peng; Yang, Yue; Wang, Yu; Xu, Jian; Wang, Yiding; Yu, William W

2016-12-01

Garlic was used as a green source to synthesize carbon dots (CDs) with a systematic study of the optical and structure properties. Ethylenediamine was added into the synthesis to improve the photoluminescence quantum yield (PL QY) of the CDs. Detailed structural and composition studies demonstrated that the content of N and the formation of C-N and C=N were critical to improve the PL QY. The as-synthesized CDs exhibited excellent stability in a wide pH range and high NaCl concentrations, rendering them applicable in complicated and harsh conditions. Quenching the fluorescence of the CDs in the presence of Fe(3+) ion made these CDs a luminescent probe for selective detection of Fe(3+) ion.

Nanobiotechnology of Carbon Dots: A Review.

PubMed

Durán, Nelson; Simões, Mateus B; de Moraes, Ana C M; Fávaro, Wagner J; Seabra, Amedea B

2016-07-01

In recent years, carbon dots (CDs) have gained increasing attention owing to their unique properties and enormous potential for several biomedical and technological applications. CDs are biocompatible, have a small size with a relatively large surface area, are photostable, and have customizable photoluminescence properties. This review is divided into the following discussions of CDs: general definitions; an overview of recent reviews; methods of green and classical synthesis; applications in bioimaging, involving supercapacitors, nanocarriers and nanomedicine; toxicological evaluations (including cytotoxic, genotoxic and anti-cancer properties of CDs); their conjugation with enzymes, biosensors, and cell labeling. Finally the remaining drawbacks and challenges of CD applications are highlighted. In this context, this article aims to provide critical insight and inspire further developments in the synthesis and application of CDs.

Tuning band alignment by CdS layers using a SILAR method to enhance TiO2/CdS/CdSe quantum-dot solar-cell performance.

PubMed

Zhang, Bingkai; Zheng, Jiaxin; Li, Xiaoning; Fang, Yanyan; Wang, Lin-Wang; Lin, Yuan; Pan, Feng

2016-04-28

We report tuning band alignment by optimized CdS layers using a SILAR method to achieve the recorded best performance with about 6% PCE in TiO2/CdS/CdSe QDSSCs. Combining experimental and theoretical studies, we find that a better lattices match between CdS and TiO2 assists the growth of CdSe, and the combined effect of charge transfer and surface dipole moment at the TiO2/CdS/CdSe interface shifts the energy levels of TiO2 upward and increases Voc of the solar cells. More importantly, the band gap of CdS buffer layers is sensitive to the distortion induced by lattice mismatch and numbers of CdS layers. For example, the barrier for charge transfer disappears when there are more than 4 layers of CdS, facilitating the charge injection from CdSe to TiO2.

Psychometric Properties of the Persian Version of Care Dependency Scale in Nursing Homes.

PubMed

Rajabi, Gholamreza; Namadmalan, Masoume; Dijkstra, Ate; Ghasemzade, Roya; Foroughan, Mahshid; Zahednejad, Shahla

The purpose of the study was to examine the psychometric properties of the Persian version of the Care Dependency Scale (CDS) in nursing homes. Instrument development. The English version of the CDS was translated into Persian. A convenience sample of 140 (100 older people without dementia and 40 patients with dementia) Persian-speaking people were selected from the nursing homes in Ahvaz, Iran. Cronbach's alpha, discriminant validity, and construct validity (exploratory factor analysis) were examined. Exploratory factor analysis indicated that the CDS has two factors, including psychosocial and somatic factors. Discriminant validity showed that the CDS can differentiate patients with dementia from the older adults without dementia. The results of the study showed that the Persian CDS is a reliable and valid scale when used in nursing homes. The Persian version of the CDS can help clinicians and nurses to assess patients' need and the degree of care dependency among older adults in Persian-speaking areas.

Proposal for fulfilling strategic objectives of the U.S. Roadmap for national action on clinical decision support through a service-oriented architecture leveraging HL7 services.

PubMed

Kawamoto, Kensaku; Lobach, David F

2007-01-01

Despite their demonstrated effectiveness, clinical decision support (CDS) systems are not widely used within the U.S. The Roadmap for National Action on Clinical Decision Support, published in June 2006 by the American Medical Informatics Association, identifies six strategic objectives for achieving widespread adoption of effective CDS capabilities. In this manuscript, we propose a Service-Oriented Architecture (SOA) for CDS that facilitates achievement of these six objectives. Within the proposed framework, CDS capabilities are implemented through the orchestration of independent software services whose interfaces are being standardized by Health Level 7 and the Object Management Group through their joint Healthcare Services Specification Project (HSSP). Core services within this framework include the HSSP Decision Support Service, the HSSP Common Terminology Service, and the HSSP Retrieve, Locate, and Update Service. Our experiences, and those of others, indicate that the proposed SOA approach to CDS could enable the widespread adoption of effective CDS within the U.S. health care system.

Engineering iodine-doped carbon dots as dual-modal probes for fluorescence and X-ray CT imaging.

PubMed

Zhang, Miaomiao; Ju, Huixiang; Zhang, Li; Sun, Mingzhong; Zhou, Zhongwei; Dai, Zhenyu; Zhang, Lirong; Gong, Aihua; Wu, Chaoyao; Du, Fengyi

2015-01-01

X-ray computed tomography (CT) is the most commonly used imaging technique for noninvasive diagnosis of disease. In order to improve tissue specificity and prevent adverse effects, we report the design and synthesis of iodine-doped carbon dots (I-doped CDs) as efficient CT contrast agents and fluorescence probe by a facile bottom-up hydrothermal carbonization process. The as-prepared I-doped CDs are monodispersed spherical nanoparticles (a diameter of ~2.7 nm) with favorable dispersibility and colloidal stability in water. The aqueous solution of I-doped CDs showed wavelength-dependent excitation and stable photoluminescence similar to traditional carbon quantum dots. Importantly, I-doped CDs displayed superior X-ray attenuation properties in vitro and excellent biocompatibility. After intravenous injection, I-doped CDs were distributed throughout the body and excreted by renal clearance. These findings validated that I-doped CDs with high X-ray attenuation potency and favorable photoluminescence show great promise for biomedical research and disease diagnosis.

Engineering iodine-doped carbon dots as dual-modal probes for fluorescence and X-ray CT imaging

PubMed Central

Zhang, Miaomiao; Ju, Huixiang; Zhang, Li; Sun, Mingzhong; Zhou, Zhongwei; Dai, Zhenyu; Zhang, Lirong; Gong, Aihua; Wu, Chaoyao; Du, Fengyi

2015-01-01

X-ray computed tomography (CT) is the most commonly used imaging technique for noninvasive diagnosis of disease. In order to improve tissue specificity and prevent adverse effects, we report the design and synthesis of iodine-doped carbon dots (I-doped CDs) as efficient CT contrast agents and fluorescence probe by a facile bottom-up hydrothermal carbonization process. The as-prepared I-doped CDs are monodispersed spherical nanoparticles (a diameter of ~2.7 nm) with favorable dispersibility and colloidal stability in water. The aqueous solution of I-doped CDs showed wavelength-dependent excitation and stable photoluminescence similar to traditional carbon quantum dots. Importantly, I-doped CDs displayed superior X-ray attenuation properties in vitro and excellent biocompatibility. After intravenous injection, I-doped CDs were distributed throughout the body and excreted by renal clearance. These findings validated that I-doped CDs with high X-ray attenuation potency and favorable photoluminescence show great promise for biomedical research and disease diagnosis. PMID:26609232

Template-free solution approach to synthesize CdS dendrites with SCN based ionic liquid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Kangfeng; Li, Jiajia; Cheng, Xianyi

2011-07-15

Highlights: {yields} Template-free solution approach to synthesize CdS hierarchical dendrites. {yields} The 1-butyl-3-methlyimidazole thiocyanate ([BMIM][SCN]) plays doubly functional roles in the progress. {yields} The CdS hierarchical dendrites exhibit a more intense emission at 710 nm belongs to infrared band. -- Abstract: Cadmium sulfide dendrites were synthesized by a facile hydrothermal treatment from CdCl{sub 2} and ionic liquid 1-butyl-3-methlyimidazole thiocyanate acted both as sulfur source and surfactant. The product was characterized by means of X-ray powder diffraction and scanning electron microscopy. X-ray powder diffraction studies indicated that the product was well-crystallized hexagonal phase of CdS, and the scanning electron microscopy imagesmore » showed that the obtained powders consisted of a wealth of well-defined CdS dendritic microstructures with a pronounced trunk and highly ordered branches. The UV-Vis and photoluminescence spectroscopy measurements were taken as well. The possible formation mechanism of CdS dendrites was simply proposed in the end.« less

Prominence of fusion temperature and engineering heteroatoms on multifarious emissive shifts in carbon dots.

PubMed

Velusamy, Jayaramakrishnan; Ramos-Ortiz, Gabriel; Rodríguez, Mario; Hernández-Cruz, Olivia; Ponce, Arturo

2018-05-16

We present a simple but robust strategy to engineering heteroatoms (N, S) on carbon dots (CDs) surface that results in a collection of enhanced photoluminescence (PL) emissions. The use of citric acid (CA) and 2-Imidazolidinethione (2-IZT) as precursors was envisioned to study the impact of thermolysis process on the PL properties. The proposed strategy, implemented at two different temperatures (180 °C and 200 °C), is suitable to produce CDs with tunable PL and quantum yield (QY) up to ∼32%. Similar to earlier reports of CA-based CDs, the self-assembling of fluorophores integrated into the CDs edge is hypothesized, however, in our CDs a double intriguing effect of blue- and red-shifting can be observed for PL as the wavelength of excitation is increased in the range 280-480 nm. Through a comprehensive characterization and evaluation of these CDs in water suspensions, the mechanisms that lead to PL multifarious emissions are proposed. Copyright © 2018 Elsevier Inc. All rights reserved.

Enhancements in healthcare information technology systems: customizing vendor-supplied clinical decision support for a high-risk patient population.

PubMed

Tiwari, Ruchi; Tsapepas, Demetra S; Powell, Jaclyn T; Martin, Spencer T

2013-01-01

Healthcare organizations continue to adopt information technologies with clinical decision support (CDS) to prevent potential medication-related adverse drug events. End-users who are unfamiliar with certain high-risk patient populations are at an increased risk of unknowingly causing medication errors. The following case describes a heart transplant recipient exposed to supra-therapeutic concentrations of tacrolimus during co-administration of ritonavir as a result of vendor supplied CDS tools that omitted an interaction alert. After review of 4692 potential tacrolimus-based DDIs between 329 different drug pairs supplied by vendor CDS, the severity of 20 DDIs were downgraded and the severity of 62 were upgraded. The need for institution-specific customization of vendor-provided CDS is paramount to ensure avoidance of medication errors. Individualized care will become more important as patient populations and institutions become more specialized. In the future, vendors providing integrated CDS tools must be proactive in developing institution-specific and easily customizable CDS tools.

Enhancements in healthcare information technology systems: customizing vendor-supplied clinical decision support for a high-risk patient population

PubMed Central

Tiwari, Ruchi; Tsapepas, Demetra S; Powell, Jaclyn T

2013-01-01

Healthcare organizations continue to adopt information technologies with clinical decision support (CDS) to prevent potential medication-related adverse drug events. End-users who are unfamiliar with certain high-risk patient populations are at an increased risk of unknowingly causing medication errors. The following case describes a heart transplant recipient exposed to supra-therapeutic concentrations of tacrolimus during co-administration of ritonavir as a result of vendor supplied CDS tools that omitted an interaction alert. After review of 4692 potential tacrolimus-based DDIs between 329 different drug pairs supplied by vendor CDS, the severity of 20 DDIs were downgraded and the severity of 62 were upgraded. The need for institution-specific customization of vendor-provided CDS is paramount to ensure avoidance of medication errors. Individualized care will become more important as patient populations and institutions become more specialized. In the future, vendors providing integrated CDS tools must be proactive in developing institution-specific and easily customizable CDS tools. PMID:22813760

Photochemical Fabrication of Transition Metal Nanoparticles Using CdS Template and Their Co-Catalysis Effects for TiO2 Photocatalysis

NASA Astrophysics Data System (ADS)

Badhwar, Nidhi; Gupta, Nidhi; Pal, Bonamali

2013-09-01

Transition metal nanoparticles were prepared by chemical dissolution of CdS template from metal photodeposited CdS nanorod (length = 70-85 nm and width = 5-6 nm) heterocomposites. Size (9-10 nm) of metal nanoparticles obtained after CdS removal was larger than the size (4-6 nm) of metal nanodeposits over CdS template. The obtained Au nanoparticles displayed a broad red shifted absorption band at 660 nm, whereas Pt, Pd and Rh nanoparticles exhibit featureless absorption spectra. Elemental analysis confirms the complete removal of CdS template from Au-CdS (Au — 2.65 at.%) and Ag-CdS (Ag — 2.06 at.%) composites showing no Cd peak. These metal nanoparticles imparted dissimilar co-catalytic activity of TiO2 for photocatalytic degradation of salicylic acid in the order Au > Pt > Pd > Ag > Rh as a function of their nature, electronegativity, redox potential and work function.

Highly Efficient Red-Emitting Carbon Dots with Gram-Scale Yield for Bioimaging.

PubMed

Ding, Hui; Wei, Ji-Shi; Zhong, Ning; Gao, Qing-Yu; Xiong, Huan-Ming

2017-11-07

Carbon dots (CDs) are a new class of photoluminescent (PL), biocompatible, environment-friendly, and low-cost carbon nanomaterials. Synthesis of highly efficient red-emitting carbon dots (R-CDs) on a gram scale is a great challenge at present, which heavily restricts the wide applications of CDs in the bioimaging field. Herein, R-CDs with a high quantum yield (QY) of 53% are produced on a gram scale by heating a formamide solution of citric acid and ethylenediamine. The as-prepared R-CDs have an average size of 4.1 nm and a nitrogen content of about 30%, with an excitation-independent emission at 627 nm. After detailed characterizations, such strong red fluorescence is ascribed to the contribution from the nitrogen- and oxygen-related surface states and the nitrogen-derived structures in the R-CD cores. Our R-CDs show good photostability and low cytotoxicity, and thus they are excellent red fluorescence probes for bioimaging both in vitro and in vivo.

Carbon dot/polyvinylpyrrolidone hybrid nanofibers with efficient solid-state photoluminescence constructed using an electrospinning technique

NASA Astrophysics Data System (ADS)

Zhai, Yue; Bai, Xue; Cui, Haining; Zhu, Jinyang; Liu, Wei; Zhang, Tianxiang; Dong, Biao; Pan, Gencai; Xu, Lin; Zhang, Shuang; Song, Hongwei

2018-01-01

Carbon dots (CDs) are the promising candidates for application in optoelectronic and biological areas due to their excellent photostability, unique photoluminescence, good biocompatibility, low toxicity and chemical inertness. However, the self-quenching of photoluminescence as they are dried into the solid state dramatically limits their further application. Therefore, realizing efficient photoluminescence and large-scale production of CDs in the solid state is an urgent challenge. Herein, solid-state hybrid nanofibers based on CDs and polyvinylpyrrolidone (PVP) are constructed through an electrospinning process. The resulting solid-state hybrid PVP/CD nanofibers present much enhanced photoluminescence performance compared to the corresponding pristine colloidal CDs due to the decrease in non-radiative recombination of electron-holes. Owing to the suppressed self-quenching of CDs, the photoluminescence quantum yield is considerably improved from 42.9% of pristine CDs to 83.5% of nanofibers under the excitation wavelength of 360 nm. This has great application potential in optical or optoelectronic devices.

Cultivating Fluorescent Flowers with Highly Luminescent Carbon Dots Fabricated by a Double Passivation Method

PubMed Central

Chang, Tao; Zhao, Haiping; Du, Huanhuan; Liu, Shan; Wu, Baoshuang; Qin, Shenjun

2017-01-01

In this work, we present the fabrication of highly luminescent carbon dots (CDs) by a double passivation method with the assistance of Ca(OH)2. In the reaction process, Ca2+ protects the active functional groups from overconsumption during dehydration and carbonization, and the electron-withdrawing groups on the CD surface are converted to electron-donating groups by the hydroxyl ions. As a result, the fluorescence quantum yield of the CDs was found to increase with increasing Ca(OH)2 content in the reaction process. A blue-shift optical spectrum of the CDs was also found with increasing Ca(OH)2 content, which could be attributed to the increasing of the energy gaps for the CDs. The highly photoluminescent CDs obtained (quantum yield: 86%) were used to cultivate fluorescent carnations by a water culture method, while the results of fluorescence microscopy analysis indicated that the CDs had entered the plant tissue structure. PMID:28686178

Mesoporous structured MIPs@CDs fluorescence sensor for highly sensitive detection of TNT.

PubMed

Xu, Shoufang; Lu, Hongzhi

2016-11-15

A facile strategy was developed to prepare mesoporous structured molecularly imprinted polymers capped carbon dots (M-MIPs@CDs) fluorescence sensor for highly sensitive and selective determination of TNT. The strategy using amino-CDs directly as "functional monomer" for imprinting simplify the imprinting process and provide well recognition sites accessibility. The as-prepared M-MIPs@CDs sensor, using periodic mesoporous silica as imprinting matrix, and amino-CDs directly as "functional monomer", exhibited excellent selectivity and sensitivity toward TNT with detection limit of 17nM. The recycling process was sustainable for 10 times without obvious efficiency decrease. The feasibility of the developed method in real samples was successfully evaluated through the analysis of TNT in soil and water samples with satisfactory recoveries of 88.6-95.7%. The method proposed in this work was proved to be a convenient and practical way to prepare high sensitive and selective fluorescence MIPs@CDs sensors. Copyright © 2016 Elsevier B.V. All rights reserved.

Synthesis and spectral studies on Cd(II) dithiocarbamate complexes and their use as precursors for CdS nanoparticles

NASA Astrophysics Data System (ADS)

Sathiyaraj, Ethiraj; Padmavathy, Krishnaraj; Kumar, Chandran Udhaya; Krishnan, Kannan Gokula; Ramalingan, Chennan

2017-11-01

Bis(N-cyclopropyl-N-4-chlorobenzyldithiocarbamato-S,S‧)cadmium(II) (1) and (2,2‧-bipyridine) bis(N-cyclopropyl-N-4-chlorobenzyldithiocarbamato-S,S‧)cadmium(II) (2) have been synthesized and characterized by FT-IR, 1HNMR and 13C NMR analyses. For the complex 2, single crystal X-ray diffraction analysis and computational studies (optimized geometry, HOMO-LUMO and MEP) have been executed employing DFT/B3LYP method with LANL 2DZ basic set. The optimized bond lengths and bond angles agree well with the experimental results. The complexes 1 and 2 have been used as single source precursors for the synthesis of ethyleneglycol capped CdS1 and CdS2 nanoparticles, respectively. CdS1 and CdS2 nanoparticles have been synthesized by solvothermal method. PXRD, SEM, Elemental colour mapping, EDAX, TEM and UV-Vis spectroscopy have been used to characterize the as-prepared CdS nanoparticles. The X-ray diffraction pattern confirms both their hexagonal structures.

Designing Real-time Decision Support for Trauma Resuscitations

PubMed Central

Yadav, Kabir; Chamberlain, James M.; Lewis, Vicki R.; Abts, Natalie; Chawla, Shawn; Hernandez, Angie; Johnson, Justin; Tuveson, Genevieve; Burd, Randall S.

2016-01-01

Background Use of electronic clinical decision support (eCDS) has been recommended to improve implementation of clinical decision rules. Many eCDS tools, however, are designed and implemented without taking into account the context in which clinical work is performed. Implementation of the pediatric traumatic brain injury (TBI) clinical decision rule at one Level I pediatric emergency department includes an electronic questionnaire triggered when ordering a head computed tomography using computerized physician order entry (CPOE). Providers use this CPOE tool in less than 20% of trauma resuscitation cases. A human factors engineering approach could identify the implementation barriers that are limiting the use of this tool. Objectives The objective was to design a pediatric TBI eCDS tool for trauma resuscitation using a human factors approach. The hypothesis was that clinical experts will rate a usability-enhanced eCDS tool better than the existing CPOE tool for user interface design and suitability for clinical use. Methods This mixed-methods study followed usability evaluation principles. Pediatric emergency physicians were surveyed to identify barriers to using the existing eCDS tool. Using standard trauma resuscitation protocols, a hierarchical task analysis of pediatric TBI evaluation was developed. Five clinical experts, all board-certified pediatric emergency medicine faculty members, then iteratively modified the hierarchical task analysis until reaching consensus. The software team developed a prototype eCDS display using the hierarchical task analysis. Three human factors engineers provided feedback on the prototype through a heuristic evaluation, and the software team refined the eCDS tool using a rapid prototyping process. The eCDS tool then underwent iterative usability evaluations by the five clinical experts using video review of 50 trauma resuscitation cases. A final eCDS tool was created based on their feedback, with content analysis of the evaluations performed to ensure all concerns were identified and addressed. Results Among 26 EPs (76% response rate), the main barriers to using the existing tool were that the information displayed is redundant and does not fit clinical workflow. After the prototype eCDS tool was developed based on the trauma resuscitation hierarchical task analysis, the human factors engineers rated it to be better than the CPOE tool for nine of 10 standard user interface design heuristics on a three-point scale. The eCDS tool was also rated better for clinical use on the same scale, in 84% of 50 expert–video pairs, and was rated equivalent in the remainder. Clinical experts also rated barriers to use of the eCDS tool as being low. Conclusions An eCDS tool for diagnostic imaging designed using human factors engineering methods has improved perceived usability among pediatric emergency physicians. PMID:26300010

A Large-Particle Monte Carlo Code for Simulating Non-Linear High-Energy Processes Near Compact Objects

NASA Technical Reports Server (NTRS)

Stern, Boris E.; Svensson, Roland; Begelman, Mitchell C.; Sikora, Marek

1995-01-01

High-energy radiation processes in compact cosmic objects are often expected to have a strongly non-linear behavior. Such behavior is shown, for example, by electron-positron pair cascades and the time evolution of relativistic proton distributions in dense radiation fields. Three independent techniques have been developed to simulate these non-linear problems: the kinetic equation approach; the phase-space density (PSD) Monte Carlo method; and the large-particle (LP) Monte Carlo method. In this paper, we present the latest version of the LP method and compare it with the other methods. The efficiency of the method in treating geometrically complex problems is illustrated by showing results of simulations of 1D, 2D and 3D systems. The method is shown to be powerful enough to treat non-spherical geometries, including such effects as bulk motion of the background plasma, reflection of radiation from cold matter, and anisotropic distributions of radiating particles. It can therefore be applied to simulate high-energy processes in such astrophysical systems as accretion discs with coronae, relativistic jets, pulsar magnetospheres and gamma-ray bursts.

Advising Medical Students for the Match: A National Survey of Pediatrics Clerkship Directors.

PubMed

Ryan, Michael S; Levine, Leonard J; Colbert-Getz, Jorie M; Spector, Nancy D; Fromme, H Barrett

2015-01-01

To describe the role and perspectives of pediatrics clerkship directors (CDs) who provide advice to students who apply to Pediatrics residency training programs. We developed a survey based on previous studies and data from the 2012 National Residency Matching Program- Program Director (NRMP-PD) survey. Topics included CDs roles and confidence in advising, perspectives on applicants' competitiveness, and resources used to inform advising practice. This survey was disseminated as part of the 2013 Council on Medical Student Education in Pediatrics annual survey. CDs from 63 (45%) Liaison Committee for Medical Education-accredited medical schools in the United States responded. All CDs had some advising role, and most (68%) served in a formal advising capacity. Most (58%) also participated in the intern selection process at their institution. Those with formal advising roles were not significantly more confident in their advising than those without formal roles. CDs relied heavily on subjective resources and most did not use the NRMP-PD survey data. Despite this, the perspectives of CDs were similar to those of program directors based on the most recent NRMP-PD survey. Pediatrics CDs uniformly serve in advising capacities and have perspectives that compare favorably with those of program directors. Despite this concordance, the high reliance on subjective resources and the frequency in which CDs participate in intern selection raises concern. The results of this study have several implications for key stakeholders in the residency selection process. Copyright © 2015 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Key principles for a national clinical decision support knowledge sharing framework: synthesis of insights from leading subject matter experts.

PubMed

Kawamoto, Kensaku; Hongsermeier, Tonya; Wright, Adam; Lewis, Janet; Bell, Douglas S; Middleton, Blackford

2013-01-01

To identify key principles for establishing a national clinical decision support (CDS) knowledge sharing framework. As part of an initiative by the US Office of the National Coordinator for Health IT (ONC) to establish a framework for national CDS knowledge sharing, key stakeholders were identified. Stakeholders' viewpoints were obtained through surveys and in-depth interviews, and findings and relevant insights were summarized. Based on these insights, key principles were formulated for establishing a national CDS knowledge sharing framework. Nineteen key stakeholders were recruited, including six executives from electronic health record system vendors, seven executives from knowledge content producers, three executives from healthcare provider organizations, and three additional experts in clinical informatics. Based on these stakeholders' insights, five key principles were identified for effectively sharing CDS knowledge nationally. These principles are (1) prioritize and support the creation and maintenance of a national CDS knowledge sharing framework; (2) facilitate the development of high-value content and tooling, preferably in an open-source manner; (3) accelerate the development or licensing of required, pragmatic standards; (4) acknowledge and address medicolegal liability concerns; and (5) establish a self-sustaining business model. Based on the principles identified, a roadmap for national CDS knowledge sharing was developed through the ONC's Advancing CDS initiative. The study findings may serve as a useful guide for ongoing activities by the ONC and others to establish a national framework for sharing CDS knowledge and improving clinical care.

Reducing risk with clinical decision support: a study of closed malpractice claims.

PubMed

Zuccotti, G; Maloney, F L; Feblowitz, J; Samal, L; Sato, L; Wright, A

2014-01-01

Identify clinical opportunities to intervene to prevent a malpractice event and determine the proportion of malpractice claims potentially preventable by clinical decision support (CDS). Cross-sectional review of closed malpractice claims over seven years from one malpractice insurance company and seven hospitals in the Boston area. For each event, clinical opportunities to intervene to avert the malpractice event and the presence or absence of CDS that might have a role in preventing the event, were assigned by a panel of expert raters. Compensation paid out to resolve a claim (indemnity), was associated with each CDS type. Of the 477 closed malpractice cases, 359 (75.3%) were categorized as substantiated and 195 (54%) had at least one opportunity to intervene. Common opportunities to intervene related to performance of procedure, diagnosis, and fall prevention. We identified at least one CDS type for 63% of substantiated claims. The 41 CDS types identified included clinically significant test result alerting, diagnostic decision support and electronic tracking of instruments. Cases with at least one associated intervention accounted for $40.3 million (58.9%) of indemnity. CDS systems and other forms of health information technology (HIT) are expected to improve quality of care, but their potential to mitigate risk had not previously been quantified. Our results suggest that, in addition to their known benefits for quality and safety, CDS systems within HIT have a potential role in decreasing malpractice payments. More than half of malpractice events and over $40 million of indemnity were potentially preventable with CDS.

Cadmium sulfide quantum dots induce oxidative stress and behavioral impairments in the marine clam Scrobicularia plana.

PubMed

Buffet, Pierre-Emmanuel; Zalouk-Vergnoux, Aurore; Poirier, Laurence; Lopes, Christelle; Risso-de-Faverney, Christine; Guibbolini, Marielle; Gilliland, Douglas; Perrein-Ettajani, Hanane; Valsami-Jones, Eugenia; Mouneyrac, Catherine

2015-07-01

Cadmium sulfide (CdS) quantum dots have a number of current applications in electronics and solar cells and significant future potential in medicine. The aim of the present study was to examine the toxic effects of CdS quantum dots on the marine clam Scrobicularia plana exposed for 14 d to these nanomaterials (10 µg Cd L(-1) ) in natural seawater and to compare them with soluble Cd. Measurement of labile Cd released from CdS quantum dots showed that 52% of CdS quantum dots remained in the nanoparticulate form. Clams accumulated the same levels of Cd regardless of the form in which it was delivered (soluble Cd vs CdS quantum dots). However, significant changes in biochemical responses were observed in clams exposed to CdS quantum dots compared with soluble Cd. Increased activities of catalase and glutathione-S-transferase were significantly higher in clams exposed in seawater to Cd as the nanoparticulate versus the soluble form, suggesting a specific nano effect. The behavior of S. plana in sediment showed impairments of foot movements only in the case of exposure to CdS quantum dots. The results show that oxidative stress and behavior biomarkers are sensitive predictors of CdS quantum dots toxicity in S. plana. Such responses, appearing well before changes might occur at the population level, demonstrate the usefulness of this model species and type of biomarker in the assessment of nanoparticle contamination in estuarine ecosystems. © 2015 SETAC.

Surface and interface of epitaxial CdTe film on CdS buffered van der Waals mica substrate

NASA Astrophysics Data System (ADS)

Yang, Y.-B.; Seewald, L.; Mohanty, Dibyajyoti; Wang, Y.; Zhang, L. H.; Kisslinger, K.; Xie, Weiyu; Shi, J.; Bhat, I.; Zhang, Shengbai; Lu, T.-M.; Wang, G.-C.

2017-08-01

Single crystal CdTe films are desirable for optoelectronic device applications. An important strategy of creating films with high crystallinity is through epitaxial growth on a proper single crystal substrate. We report the metalorganic chemical vapor deposition of epitaxial CdTe films on the CdS/mica substrate. The epitaxial CdS film was grown on a mica surface by thermal evaporation. Due to the weak van der Waals forces, epitaxy is achieved despite the very large interface lattice mismatch between CdS and mica (∼21-55%). The surface morphology of mica, CdS and CdTe were quantified by atomic force microscopy. The near surface structures, orientations and texture of CdTe and CdS films were characterized by the unique reflection high-energy electron diffraction surface pole figure technique. The interfaces of CdTe and CdS films and mica were characterized by X-ray pole figure technique and transmission electron microscopy. The out-of-plane and in-plane epitaxy of the heteroepitaxial films stack are determined to be CdTe(111)//CdS(0001)//mica(001) and [1 bar2 1 bar]CdTe//[ 1 bar100]CdS//[010]mica, respectively. The measured photoluminescence (PL), time resolved PL, photoresponse, and Hall mobility of the CdTe/CdS/mica indicate quality films. The use of van der Waals surface to grow epitaxial CdTe/CdS films offers an alternative strategy towards infrared imaging and solar cell applications.

A carbon dot-based "off-on" fluorescent probe for highly selective and sensitive detection of phytic acid.

PubMed

Gao, Zhao; Wang, Libing; Su, Rongxin; Huang, Renliang; Qi, Wei; He, Zhimin

2015-08-15

We herein report a facile, one-step pyrolysis synthesis of photoluminescent carbon dots (CDs) using citric acid as the carbon source and lysine as the surface passivation reagent. The as-prepared CDs show narrow size distribution, excellent blue fluorescence and good photo-stability and water dispersivity. The fluorescence of the CDs was found to be effectively quenched by ferric (Fe(III)) ions with high selectivity via a photo-induced electron transfer (PET) process. Upon addition of phytic acid (PA) to the CDs/Fe(III) complex dispersion, the fluorescence of the CDs was significantly recovered, arising from the release of Fe(III) ions from the CDs/Fe(III) complex because PA has a higher affinity for Fe(III) ions compared to CDs. Furthermore, we developed an "off-on" fluorescence assay method for the detection of phytic acid using CDs/Fe(III) as a fluorescent probe. This probe enables the selective detection of PA with a linear range of 0.68-18.69 μM and a limit of detection (signal-to-noise ratio is 3) of 0.36 μM. The assay method demonstrates high selectivity, repeatability, stability and recovery ratio in the detection of the standard and real PA samples. We believe that the facile operation, low-cost, high sensitivity and selectivity render this CD-based "off-on" fluorescent probe an ideal sensing platform for the detection of PA. Copyright © 2015 Elsevier B.V. All rights reserved.

Uniform β-Co(OH)2 disc-like nanostructures prepared by low-temperature electrochemical rout as an electrode material for supercapacitors

NASA Astrophysics Data System (ADS)

Aghazadeh, Mustafa; Shiri, Hamid Mohammad; Barmi, Abbas-Ali Malek

2013-05-01

Uniform nanostructures of cobalt hydroxide were successfully prepared by a low-temperature electrochemical method via galvanostatically deposition from a 0.005 M Co(NO3)3 bath at 10 °C. The XRD and FT-IR analyses showed that the prepared sample has a single crystalline hexagonal phase of the brucite-like Co(OH)2. Morphological characterization by SEM and TEM revealed that the prepared β-Co(OH)2 was composed of uniform compact disc-like nanostructures with diameters of 40-50 nm. The electrochemical performance of the prepared β-Co(OH)2 was evaluated using cyclic voltammetry and charge-discharge tests. A maximum specific capacitance of 736.5 F g-1 was obtained in aqueous 1 M KOH with the potential range of -0.2-0.5 V (vs. Ag/AgCl) at the scan rate of 10 mV s-1, suggesting the potential application of the prepared nanostructures as an electrode material in electrochemical supercapacitors. The results of this work showed that the low-temperature cathodic electrodeposition method can be recognized as a new and facile route for the synthesis of cobalt hydroxide nanodiscs as a promising candidate for the electrochemical supercapacitors.

Convergence of the Rogers-Ramanujan continued fraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buslaev, V I

2003-06-30

Set q=exp(2{pi}i{tau}), where {tau} is an irrational number, and let R{sub q} be the radius of holomorphy of the Rogers-Ramanujan function G{sub q}(z)=1+{sigma}{sub n=1}{sup {infinity}}z{sup n}(q{sup n{sup 2}})/((1-q)...(1-q{sup n})). As is known, R{sub q}{<=}1 and for each {alpha} element of [0,1] there exists q=q({alpha}) such that R{sub q({alpha})}={alpha}. It is proved here that the function H{sub q}(z)=G{sub q}(z)/G{sub q}(qz) is meromorphic not only in the disc =(|z|

FPGA platform for MEMS Disc Resonance Gyroscope (DRG) control

NASA Astrophysics Data System (ADS)

Keymeulen, Didier; Peay, Chris; Foor, David; Trung, Tran; Bakhshi, Alireza; Withington, Phil; Yee, Karl; Terrile, Rich

2008-04-01

Inertial navigation systems based upon optical gyroscopes tend to be expensive, large, power consumptive, and are not long lived. Micro-Electromechanical Systems (MEMS) based gyros do not have these shortcomings; however, until recently, the performance of MEMS based gyros had been below navigation grade. Boeing and JPL have been cooperating since 1997 to develop high performance MEMS gyroscopes for miniature, low power space Inertial Reference Unit applications. The efforts resulted in demonstration of a Post Resonator Gyroscope (PRG). This experience led to the more compact Disc Resonator Gyroscope (DRG) for further reduced size and power with potentially increased performance. Currently, the mass, volume and power of the DRG are dominated by the size of the electronics. This paper will detail the FPGA based digital electronics architecture and its implementation for the DRG which will allow reduction of size and power and will increase performance through a reduction in electronics noise. Using the digital control based on FPGA, we can program and modify in real-time the control loop to adapt to the specificity of each particular gyro and the change of the mechanical characteristic of the gyro during its life time.

Irradiation of an Accretion Disc by a Jet: General Properties and Implications for Spin Measurements of Black Holes

NASA Technical Reports Server (NTRS)

T.Dauser; Garcia, J.; Wilms, J.; Boeck, M.; Brenneman, L. W.; Falanga, M.; Fukumura, Keigo; Reynolds, C. S.

2013-01-01

X-ray irradiation of the accretion disc leads to strong reflection features, which are then broadened and distorted by relativistic effects. We present a detailed, general relativistic approach to model this irradiation for different geometries of the primary X-ray source. These geometries include the standard point source on the rotational axis as well as more jet-like sources, which are radially elongated and accelerating. Incorporating this code in the RELLINE model for relativistic line emission, the line shape for any configuration can be predicted. We study how different irradiation geometries affect the determination of the spin of the black hole. Broad emission lines are produced only for compact irradiating sources situated close to the black hole. This is the only case where the black hole spin can be unambiguously determined. In all other cases the line shape is narrower, which could either be explained by a low spin or an elongated source. We conclude that for those cases and independent of the quality of the data, no unique solution for the spin exists and therefore only a lower limit of the spin value can be given

Digital map databases in support of avionic display systems

NASA Astrophysics Data System (ADS)

Trenchard, Michael E.; Lohrenz, Maura C.; Rosche, Henry, III; Wischow, Perry B.

1991-08-01

The emergence of computerized mission planning systems (MPS) and airborne digital moving map systems (DMS) has necessitated the development of a global database of raster aeronautical chart data specifically designed for input to these systems. The Naval Oceanographic and Atmospheric Research Laboratory''s (NOARL) Map Data Formatting Facility (MDFF) is presently dedicated to supporting these avionic display systems with the development of the Compressed Aeronautical Chart (CAC) database on Compact Disk Read Only Memory (CDROM) optical discs. The MDFF is also developing a series of aircraft-specific Write-Once Read Many (WORM) optical discs. NOARL has initiated a comprehensive research program aimed at improving the pilots'' moving map displays current research efforts include the development of an alternate image compression technique and generation of a standard set of color palettes. The CAC database will provide digital aeronautical chart data in six different scales. CAC is derived from the Defense Mapping Agency''s (DMA) Equal Arc-second (ARC) Digitized Raster Graphics (ADRG) a series of scanned aeronautical charts. NOARL processes ADRG to tailor the chart image resolution to that of the DMS display while reducing storage requirements through image compression techniques. CAC is being distributed by DMA as a library of CDROMs.

Accretion of clumpy cold gas onto massive black hole binaries: the challenging formation of extended circumbinary structures

NASA Astrophysics Data System (ADS)

Maureira-Fredes, Cristián; Goicovic, Felipe G.; Amaro-Seoane, Pau; Sesana, Alberto

2018-05-01

Massive black hole binaries (MBHBs) represent an unavoidable outcome of hierarchical galaxy formation, but their dynamical evolution at sub-parsec scales is poorly understood. In gas rich environments, an extended, steady circumbinary gaseous disc could play an important role in the MBHB evolution, facilitating its coalescence. However, how gas on galactic scales is transported to the nuclear region to form and maintain such a stable structure is unclear. In the aftermath of a galaxy merger, cold turbulent gas condenses into clumps and filaments that can be randomly scattered towards the nucleus. This provides a natural way of feeding the binary with intermittent pockets of gas. The aim of this work is to investigate the gaseous structures arising from this interaction. We employ a suite of smoothed-particle-hydrodynamic simulations to study the influence of the infall rate and angular momentum distribution of the incoming clouds on the formation and evolution of structures around the MBHB. We find that the continuous supply of discrete clouds is a double-edge sword, resulting in intermittent formation and disruption of circumbinary structures. Anisotropic cloud distributions featuring an excess of co-rotating events generate more prominent co-rotating circumbinary discs. Similar structures are seen when mostly counter-rotating clouds are fed to the binary, even though they are more compact and less stable. In general, our simulations do not show the formation of extended smooth and stable circumbinary discs, typically assumed in analytical and numerical investigations of the the long term evolution of MBHBs.

Binary centrifugal microfluidics enabling novel, digital addressable functions for valving and routing.

PubMed

Wang, Guanghui; Tan, Jie; Tang, Minghui; Zhang, Changbin; Zhang, Dongying; Ji, Wenbin; Chen, Junhao; Ho, Ho-Pui; Zhang, Xuping

2018-03-16

Centrifugal microfluidics or lab-on-a-disc (LOAD) is a promising branch of lab-on-a-chip or microfluidics. Besides effective fluid transportation and inherently available density-based sample separation in centrifugal microfluidics, uniform actuation of flow on the disc makes the platform compact and scalable. However, the natural radially outward centrifugal force in a LOAD system limits its capacity to perform complex fluid manipulation steps. In order to increase the fluid manipulation freedom and integration capacity of the LOAD system, we propose a binary centrifugal microfluidics platform. With the help of Euler force, our platform allows free switching of both left and right states based on a rather simple mechanical structure. The periodical switching of state would provide a "clock" signal for a sequence of droplet binary logic operations. With the binary state platform and the "clock" signal, we can accurately handle the droplet separately in each time step with a maximum main frequency of about 10 S s-1 (switching per second). Apart from droplet manipulations such as droplet generation and metering, we also demonstrate a series of droplet logic operations, such as binary valving, droplet routing and digital addressable droplet storage. Furthermore, complex bioassays such as the Bradford assay and DNA purification assay are demonstrated on a binary platform, which is totally impossible for a traditional LOAD system. Our binary platform largely improves the capability for logic operation on the LOAD platform, and it is a simple and promising approach for microfluidic lab-on-a-disc large-scale integration.

Integral field spectroscopy of nearby quasi-stellar objects - II. Molecular gas content and conditions for star formation

NASA Astrophysics Data System (ADS)

Husemann, B.; Davis, T. A.; Jahnke, K.; Dannerbauer, H.; Urrutia, T.; Hodge, J.

2017-09-01

We present single-dish 12CO(1-0) and 12CO(2-1) observations for 14 low-redshift quasi-stellar objects (QSOs). In combination with optical integral field spectroscopy, we study how the cold gas content relates to the star formation rate (SFR) and black hole accretion rate. 12CO(1-0) is detected in 8 of 14 targets and 12CO(2-1) is detected in 7 out of 11 cases. The majority of disc-dominated QSOs reveal gas fractions and depletion times matching normal star-forming systems. Two gas-rich major mergers show clear starburst signatures with higher than average gas fractions and shorter depletion times. Bulge-dominated QSO hosts are mainly undetected in 12CO(1-0), which corresponds, on average, to lower gas fractions than in disc-dominated counterparts. Their SFRs, however, imply shorter than average depletion times and higher star formation efficiencies. Negative QSO feedback through removal of cold gas seems to play a negligible role in our sample. We find a trend between black hole accretion rate and total molecular gas content for disc-dominated QSOs when combined with literature samples. We interpret this as an upper envelope for the nuclear activity and it is well represented by a scaling relation between the total and circumnuclear gas reservoir accessible for accretion. Bulge-dominated QSOs significantly differ from that scaling relation and appear uncorrelated with the total molecular gas content. This could be explained either by a more compact gas reservoir, blown out of the gas envelope through outflows, or a different interstellar medium phase composition.

Reducing Diagnostic Error with Computer-Based Clinical Decision Support

ERIC Educational Resources Information Center

Greenes, Robert A.

2009-01-01

Information technology approaches to delivering diagnostic clinical decision support (CDS) are the subject of the papers to follow in the proceedings. These will address the history of CDS and present day approaches (Miller), evaluation of diagnostic CDS methods (Friedman), and the role of clinical documentation in supporting diagnostic decision…

Unesco Integrated Documentation Network; Computerized Documentation System (CDS).

ERIC Educational Resources Information Center

United Nations Educational, Scientific, and Cultural Organization, Paris (France). Dept. of Documentation, Libraries, and Archives.

Intended for use by the Computerized Documentation System (CDS), the Unesco version of ISIS (Integrated Set of Information Systems)--originally developed by the International Labour Organization--was developed in 1975 and named CDS/ISIS. This system has a comprehensive collection of programs for input, management, and output, running in batch or…

Preparation of CdS Nanoparticles by First-Year Undergraduates

ERIC Educational Resources Information Center

Winkelmann, Kurt; Noviello, Thomas; Brooks, Stephen

2007-01-01

The first year undergraduates use a simple method to synthesize 5-nm CdS nanoparticles in a water-in-oil microemulsion. The quantum size effect, the relationship between colors, optical absorbance, band-gap energy and the CdS particles affected by the formation of micelles are observed.

The Ever-Present Demand for Public Computing Resources. CDS Spotlight

ERIC Educational Resources Information Center

Pirani, Judith A.

2014-01-01

This Core Data Service (CDS) Spotlight focuses on public computing resources, including lab/cluster workstations in buildings, virtual lab/cluster workstations, kiosks, laptop and tablet checkout programs, and workstation access in unscheduled classrooms. The findings are derived from 758 CDS 2012 participating institutions. A dataset of 529…

Effects of coordination agents on the morphology of CdS nanocrystallites synthesized by the hydrothermal method

NASA Astrophysics Data System (ADS)

Nie, Qiulin; Yuan, Qiuli; Chen, Weixiang; Xu, Zhude

2004-05-01

CdS nanocrystallites were synthesized by the hydrothermal method and characterized by XRD, TEM, and XPS, respectively. Different coordination agents were chosen as the template to investigate their effects on the product morphology. It was found that the CdS nanocrystallites displayed a rod-like shape when ethylenediamine or methylamine were employed as the template. In contrast, only nanoparticles of CdS were observed when ammonia or pyridine were used. Based on our experimental results, a complex structure-controlling mechanism is proposed.

Chemical synthesis of CdS onto TiO2 nanorods for quantum dot sensitized solar cells

NASA Astrophysics Data System (ADS)

Pawar, Sachin A.; Patil, Dipali S.; Lokhande, Abhishek C.; Gang, Myeng Gil; Shin, Jae Cheol; Patil, Pramod S.; Kim, Jin Hyeok

2016-08-01

A quantum dot sensitized solar cell (QDSSC) is fabricated using hydrothermally grown TiO2 nanorods and successive ionic layer adsorption and reaction (SILAR) deposited CdS. Surface morphology of the TiO2 films coated with different SILAR cycles of CdS is examined by Scanning Electron Microscopy which revealed aggregated CdS QDs coverage grow on increasing onto the TiO2 nanorods with respect to cycle number. Under AM 1.5G illumination, we found the TiO2/CdS QDSSC photoelectrode shows a power conversion efficiency of 1.75%, in an aqueous polysulfide electrolyte with short-circuit photocurrent density of 4.04 mA/cm2 which is higher than that of a bare TiO2 nanorods array.

Bacteria-Derived Carbon Dots Inhibit Biofilm Formation of Escherichia coli without Affecting Cell Growth

PubMed Central

Lin, Fengming; Li, Chengcheng; Chen, Zhan

2018-01-01

Biofilms are deleterious in many biomedical and industrial applications and prevention of their formation has been a pressing challenge. Here, carbon dots, CDs-LP that were easily synthesized from the biomass of Lactobacillus plantarum by one-step hydrothermal carbonization, were demonstrated to prevent biofilm formation of E. coli. CDs-LP did not thwart the growth of E. coli, indicating the anti-biofilm effect was not due to the bactericidal effect. Moreover, CDs-LP did not affect the growth of the animal cell AT II, showing low cytotoxicity, good safety and excellent biocompatibility. Therefore, CDs-LP could overcome the cytotoxicity issue found in many current antibiofilm agents. CDs-LP represent a new type of anti-biofilm materials, opening up a novel avenue to the development of biofilm treatment. PMID:29503644

The preparation of ethylenediamine-modified fluorescent carbon dots and their use in imaging of cells.

PubMed

Dong, Wei; Zhou, Siqi; Dong, Yan; Wang, Jingwen; Ge, Xin; Sui, Lili

2015-09-01

In this work, fluorescent carbon dots (CDs) were synthesized using a hydrothermal method with glucose as the carbon source and were surface-modified with ethylenediamine. The properties of as-prepared CDs were analyzed by transmission electron microscopy (TEM), Fourier transform infrared (FTIR), ultraviolet-visible light (UV/vis) absorption and fluorescent spectra. Furthermore, CDs conjugated with mouse anti-(human carcinoembryonic antigen) (CEA) monoclonal antibody were successful employed in the biolabeling and fluorescent imaging of human gastric carcinoma cells. In addition, the cytotoxicity of CDs was also tested using human gastric carcinoma cells. There was no apparent cytotoxicity on human gastric carcinoma cells. These results suggest the potential application of the as-prepared CDs in bioimaging and related fields. Copyright © 2015 John Wiley & Sons, Ltd.

Photoluminescence and structural characteristics of CdS nanoclusters synthesized by hydrothermal microemulsion

NASA Astrophysics Data System (ADS)

Liu, Bing; Xu, G. Q.; Gan, L. M.; Chew, C. H.; Li, W. S.; Shen, Z. X.

2001-01-01

Spherical and uniform CdS nanoclusters were synthesized by hydrothermal microemulsion. The reaction of Cd2+ ions with S2- ions generated from the decomposition of thioacetamide proceeded in water microdroplets. The mean diameter of the CdS nanoclusters can be varied from 20 to 80 nm by increasing the reaction temperature from 30 to 120 °C. XRD results indicate that the resulting CdS nanoclusters have a reduced and distorted hexagonal lattice compared to bulk materials. Two intense luminescence bands, i.e., green and red, were observed to coexist in the CdS nanoclusters. Their peak positions and relative intensities were found to be sensitive to the size and structure of nanoclusters. These emissions are attributed to surface defects (green emission) and the Cd-Cl composite vacancies (red emission).

Enhanced photocatalytic hydrogen evolution from in situ formation of few-layered MoS2/CdS nanosheet-based van der Waals heterostructures.

PubMed

Iqbal, Shahid; Pan, Ziwei; Zhou, Kebin

2017-05-25

Here we report for the first time that the H 2 bubbles generated by photocatalytic water splitting are effective in the layer-by-layer exfoliation of MoS 2 nanocrystals (NCs) into few layers. The as-obtained few layers can be in situ assembled with CdS nanosheets (NSs) into van der Waals heterostructures (vdWHs) of few-layered MoS 2 /CdS NSs which, in turn, are effective in charge separation and transfer, leading to enhanced photocatalytic H 2 production activity. The few-layered MoS 2 /CdS vdWHs exhibited a H 2 evolution rate of 140 mmol g (CdS) -1 h -1 and achieved an apparent quantum yield of 66% at 420 nm.

Structural and optical properties of Ni-doped CdS thin films prepared by chemical bath deposition method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Premarani, R.; Saravanakumar, S., E-mail: sarophy84@gmail.com; Chandramohan, R.

2015-06-24

The structural and optical behavior of undoped Cadmiun Sulphide (CdS) and Ni-doped CdS thinfilms prepared by Chemical Bath Deposition (CBD) technique is reported. The crystallite sizes of the thinfilms have been characterized by X-ray diffraction pattern (XRD). The particle sizes increase with the increase of Ni content in the CdS thinfilms. Scanning Electron Microscope (SEM) results indicated that CdS thinfilms is made up of aggregate of spherical-like particles. The composition was estimated by Energy Dispersive Analysis of X-ray (EDX) and reported. Spectroscopic studies revealed considerable improvement in transmission and the band gap of the films changes with addition of Nimore » dopant that is associated with variation in crystallite sizes in the nano regime.« less

Structural, optical and photoelectric properties of sprayed CdS thin films

NASA Astrophysics Data System (ADS)

Chandel, Tarun; Dwivedi, Shailendra Kumar; Zaman, M. Burhanuz; Rajaram, P.

2018-05-01

In this study, CdS thin films were grown via a facile spray pyrolysis technique. The crystalline phase, morphological, compositional and optical properties of the CdS thin films have been studied using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and UV-vis absorption spectroscopy, respectively. XRD patterns show that the grown CdS films crystallized in the hexagonal structure. Scanning electron microscopy (SEM) study shows that the surfaces of the films are smooth and are uniformly covered with nanoparticles. EDAX results reveal that the grown films have good stochiometry. UV-vis spectroscopy shows that the grown films have transparency above 80% over the entire visible region. The photo-electric response of the CdS films grown on glass substrates has been observed.

The catalogue of radial velocity variable hot subluminous stars from the MUCHFUSS project

NASA Astrophysics Data System (ADS)

Geier, S.; Kupfer, T.; Heber, U.; Schaffenroth, V.; Barlow, B. N.; Østensen, R. H.; O'Toole, S. J.; Ziegerer, E.; Heuser, C.; Maxted, P. F. L.; Gänsicke, B. T.; Marsh, T. R.; Napiwotzki, R.; Brünner, P.; Schindewolf, M.; Niederhofer, F.

2015-05-01

The project Massive Unseen Companions to Hot Faint Underluminous Stars from SDSS (MUCHFUSS) aims to find sdBs with compact companions such as massive white dwarfs, neutron stars, or black holes. Here we provide classifications, atmospheric parameters, and a complete radial velocity (RV) catalogue containing 1914 single measurements for a sample of 177 hot subluminous stars discovered based on SDSS DR7; 110 stars show significant RV variability, while 67 qualify as candidates. We constrain the fraction of close massive compact companions of hydrogen-rich hot subdwarfs in our sample to be smaller than ~1.3%, which is already close to the theoretical predictions. However, the sample might still contain such binaries with longer periods exceeding ~8 d. We detect a mismatch between the ΔRVmax-distribution of the sdB and the more evolved sdOB and sdO stars, which challenges our understanding of their evolutionary connection. Furthermore, irregular RV variations of unknown origin with amplitudes of up to ~180 km s-1 on timescales of years, days, and even hours have been detected in some He-sdO stars. They might be connected to irregular photometric variations in some cases. The radial velocity table is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/577/A26

Construction of an all-solid-state artificial Z-scheme system consisting of Bi2WO6/Au/CdS nanostructure for photocatalytic CO2 reduction into renewable hydrocarbon fuel.

PubMed

Wang, Meng; Han, Qiutong; Li, Liang; Tang, Lanqin; Li, Haijin; Zhou, Yong; Zou, Zhigang

2017-07-07

An all-solid-state Bi 2 WO 6 /Au/CdS Z-scheme system was constructed for the photocatalytic reduction of CO 2 into methane in the presence of water vapor. This Z-scheme consists of ultrathin Bi 2 WO 6 nanoplates and CdS nanoparticles as photocatalysts, and a Au nanoparticle as a solid electron mediator offering a high speed charge transfer channel and leading to more efficient spatial separation of electron-hole pairs. The photo-generated electrons from the conduction band (CB) of Bi 2 WO 6 transfer to the Au, and then release to the valence band (VB) of CdS to recombine with the holes of CdS. It allows the electrons remaining in the CB of CdS and holes in the VB of Bi 2 WO 6 to possess strong reduction and oxidation powers, respectively, leading the Bi 2 WO 6 /Au/CdS to exhibit high photocatalytic reduction of CO 2 , relative to bare Bi 2 WO 6 , Bi 2 WO 6 /Au, and Bi 2 WO 6 /CdS. The depressed hole density on CdS also enhances the stability of the CdS against photocorrosion.

Optical and structural properties of sputtered CdS films for thin film solar cell applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Donguk; Park, Young; Kim, Minha

2015-09-15

Graphical abstract: Photo current–voltage curves (a) and the quantum efficiency (QE) (b) for the solar cell with CdS film grown at 300 °C. - Highlights: • CdS thin films were grown by a RF magnetron sputtering method. • Influence of growth temperature on the properties of CdS films was investigated. • At higher T{sub g}, the crystallinity of the films improved and the grains enlarged. • CdS/CdTe solar cells with efficiencies of 9.41% were prepared at 300 °C. - Abstract: CdS thin films were prepared by radio frequency magnetron sputtering at various temperatures. The effects of growth temperature on crystallinity,more » surface morphology and optical properties of the films were characterized with X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Raman spectra, UV–visible spectrophotometry, and photoluminescence (PL) spectra. As the growth temperature was increased, the crystallinity of the sputtered CdS films was improved and the grains were enlarged. The characteristics of CdS/CdTe thin film solar cell appeared to be significantly influenced by the growth temperature of the CdS films. Thin film CdS/CdTe solar cells with efficiencies of 9.41% were prepared at a growth temperature of 300 °C.« less

Co-sensitization of ZnO by CdS quantum dots in natural dye-sensitized solar cells with polymeric electrolytes to improve the cell stability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Junhom, W.; Magaraphan, R.

2015-05-22

The CdS quantum dots (QDs) were deposited on ZnO layer by chemical bath deposition method to absorb light in the shorter wavelength region and used as photoanode in the dye sensitized solar cell (DSSCs) with natural dye extracted from Noni leaves. Microstructures of CdS-ZnO from various dipping time were characterized by XRD, FE-SEM and EDX. The results showed that the CdS is hexagonal structure and the amount of CdS increases when the dipping time increases. The maximal conversion efficiency of 0.292% was achieved by the DSSCs based on CdS QDs-sensitized ZnO film obtained from 9 min-dipping time. Furthermore, the stability ofmore » DSSCs was improved by using polymeric electrolyte. Poly (acrylic acid) (PAA) and Polyacrylamide (PAM) were introduced to CdS QDs-sensitized ZnO film from 9 min-dipping time. Each polymeric electrolyte was prepared by swelling from 0.1-2.0 %w in H2O. The maximal conversion efficiency of 0.207% was achieved for DSSCs based on CdS QDs-sensitized ZnO film with PAM 1.0% and the conversion efficiency was decreased 25% when it was left for1 hr.« less

Co-sensitization of ZnO by CdS quantum dots in natural dye-sensitized solar cells with polymeric electrolytes to improve the cell stability

NASA Astrophysics Data System (ADS)

Junhom, W.; Magaraphan, R.

2015-05-01

The CdS quantum dots (QDs) were deposited on ZnO layer by chemical bath deposition method to absorb light in the shorter wavelength region and used as photoanode in the dye sensitized solar cell (DSSCs) with natural dye extracted from Noni leaves. Microstructures of CdS-ZnO from various dipping time were characterized by XRD, FE-SEM and EDX. The results showed that the CdS is hexagonal structure and the amount of CdS increases when the dipping time increases. The maximal conversion efficiency of 0.292% was achieved by the DSSCs based on CdS QDs-sensitized ZnO film obtained from 9 min-dipping time. Furthermore, the stability of DSSCs was improved by using polymeric electrolyte. Poly (acrylic acid) (PAA) and Polyacrylamide (PAM) were introduced to CdS QDs-sensitized ZnO film from 9 min-dipping time. Each polymeric electrolyte was prepared by swelling from 0.1-2.0 %w in H2O. The maximal conversion efficiency of 0.207% was achieved for DSSCs based on CdS QDs-sensitized ZnO film with PAM 1.0% and the conversion efficiency was decreased 25% when it was left for1 hr.

Cu doping concentration effect on the physical properties of CdS thin films obtained by the CBD technique

NASA Astrophysics Data System (ADS)

Albor Aguilera, M. L.; Flores Márquez, J. M.; Remolina Millan, A.; Matsumoto Kuwabara, Y.; González Trujillo, M. A.; Hernández Vásquez, C.; Aguilar Hernandez, J. R.; Hernández Pérez, M. A.; Courel-Piedrahita, M.; Madeira, H. T. Yee

2017-08-01

Cu(In, Ga)Se2 (CIGS) and Cu2ZnSnS4 (CZTS) semiconductors are direct band gap materials; when these types of material are used in solar cells, they provide efficiencies of 22.1% and 12.6%, respectively. Most traditional fabrication methods involve expensive vacuum processes including co-evaporation and sputtering techniques, where films and doping are conducted separately. On the other hand, the chemical bath deposition (CBD) technique allows an in situ process. Cu-doped CdS thin films working as a buffer layer on solar cells provide good performing devices and they may be deposited by low cost techniques such as chemical methods. In this work, Cu-doped CdS thin films were deposited using the CBD technique on SnO2:F (FTO) substrates. The elemental analysis and mapping reconstruction were conducted by EDXS. Morphological, optical and electrical properties were studied, and they revealed that Cu doping modified the CdS structure, band-gap value and the electrical properties. Cu-doped CdS films show high resistivity compared to the non-doped CdS. The appropriate parameters of Cu-doped CdS films were determined to obtain an adequate window or buffer layer on CIGS and CZTS photovoltaic solar cells.

Investigations on structural, vibrational, morphological and optical properties of CdS and CdS/Co films by ultrasonic spray pyrolysis

NASA Astrophysics Data System (ADS)

Aksay, S.; Polat, M.; Özer, T.; Köse, S.; Gürbüz, G.

2011-09-01

CdS and CdS/Co films have been deposited on glass substrates by an ultrasonic spray pyrolysis method. The effects of Co incorporation on the structural, optical, morphological, elemental and vibrational properties of these films were investigated. XRD analysis confirmed the hexagonal wurtzite structure of all films and had no impurity phase. While CdS film has (0 0 2) as the preferred orientation, CdS/Co films have (1 1 0) as the preferred orientation. The direct optical band gap was found to decrease from 2.42 to 2.39 eV by Co incorporation. The decrease of the direct energy gaps by increasing Co contents is mainly due to the sp-d exchange interaction between the localized d-electrons of Co2+ ions and band electrons of CdS. After the optical investigations, it was seen that the transmittance of CdS films decreased by Co content. The Raman measurements revealed two peaks corresponding to the 1LO and 2LO modes of hexagonal CdS. The vibrational modes of Cd-S were obtained in the wavenumber range (590-715 cm-1) using Fourier transform infrared spectroscopy (FTIR). The elemental analysis of the film was done by energy dispersive X-ray spectrometry.

Efficient color-tunable multiexcitonic dual wavelength emission from Type II semiconductor tetrapods.

PubMed

Wu, Wen-Ya; Li, Mingjie; Lian, Jie; Wu, Xiangyang; Yeow, Edwin K L; Jhon, Mark H; Chan, Yinthai

2014-09-23

We synthesized colloidal InP/ZnS seeded CdS tetrapods by harnessing the structural stability of the InP/ZnS seed nanocrystals at the high reaction temperatures needed to grow the CdS arms. Because of an unexpected Type II band alignment at the interface of the InP/ZnS core and CdS arms that enhanced the occurrence of radiative excitonic recombination in CdS, these tetrapods were found to be capable of exhibiting highly efficient multiexcitonic dual wavelength emission of equal intensity at spectrally distinct wavelengths of ∼485 and ∼675 nm. Additionally, the Type II InP/ZnS seeded CdS tetrapods displayed a wider range of pump-dependent emission color-tunability (from red to white to blue) within the context of a CIE 1931 chromaticity diagram and possessed higher photostability due to suppressed multiexcitonic Auger recombination when compared to conventional Type I CdSe seeded CdS tetrapods. By employing time-resolved spectroscopy measurements, we were able to attribute the wide emission color-tunability to the large valence band offset between InP and CdS. This work highlights the importance of band alignment in the synthetic design of semiconductor nanoheterostructures, which can exhibit color-tunable multiwavelength emission with high efficiency and photostability.

Audio Restoration

NASA Astrophysics Data System (ADS)

Esquef, Paulo A. A.

The first reproducible recording of human voice was made in 1877 on a tinfoil cylinder phonograph devised by Thomas A. Edison. Since then, much effort has been expended to find better ways to record and reproduce sounds. By the mid-1920s, the first electrical recordings appeared and gradually took over purely acoustic recordings. The development of electronic computers, in conjunction with the ability to record data onto magnetic or optical media, culminated in the standardization of compact disc format in 1980. Nowadays, digital technology is applied to several audio applications, not only to improve the quality of modern and old recording/reproduction techniques, but also to trade off sound quality for less storage space and less taxing transmission capacity requirements.

Real-time observation of X-ray diffraction patterns with the Lixiscope

NASA Technical Reports Server (NTRS)

Chung, D. Y.; Tsang, T.; Yin, L. I.; Anderson, J. R.

1981-01-01

The feasibility of the Lixiscope (Low Intensity X-ray Imaging Scope) is demonstrated for real-time observation of transmission Laue patterns. Making use of the high-gain capability of microchannel plate (MCP) visible-light image intensifier tubes, X-ray images are converted to visible-light images by a scintillator. Pb discs are taped to the center of the Lixiscope input face, and crystal samples are held on a goniometer stage with modeling clay. With a compact size to facilitate off axis viewing, and real-time viewing to allow instantaneous response, the Lixiscope may prove useful in dynamic studies of the effects of plastic flows, stresses, high pressures, and low temperatures.

Drill bit assembly for releasably retaining a drill bit cutter

DOEpatents

Glowka, David A.; Raymond, David W.

2002-01-01

A drill bit assembly is provided for releasably retaining a polycrystalline diamond compact drill bit cutter. Two adjacent cavities formed in a drill bit body house, respectively, the disc-shaped drill bit cutter and a wedge-shaped cutter lock element with a removable fastener. The cutter lock element engages one flat surface of the cutter to retain the cutter in its cavity. The drill bit assembly thus enables the cutter to be locked against axial and/or rotational movement while still providing for easy removal of a worn or damaged cutter. The ability to adjust and replace cutters in the field reduces the effect of wear, helps maintains performance and improves drilling efficiency.

Observing the On-going Formation of Planets and its Effects on Their Parent Discs

NASA Astrophysics Data System (ADS)

Willson, Matthew Alexander

2017-06-01

As the number of known exoplanetary systems has grown, it has become increasing apparent that our current understanding of planet formation is insufficient to explain the broad but distinct distributions of planets and planetary systems we observe. In particular, constructing a coherent model of planetary formation and migration within a circumstellar disc which is capable of producing both hot Jupiters or Solar System-like planetary system is high challenging. Resolved observations of where planets form and how they influence their parent discs provides essential information for tackling this important question. A promising technique for detecting close-in companions is Sparse Aperture Masking (SAM). The technique uses a mask to transform a single aperture telescope into a compact interferometric array capable of reliably detecting point sources at the diffraction limit or closer to a bright star with superior contrasts than extreme AO systems at the cost of smaller fields of view. Applying image reconstruction techniques to the interferometric information allows an observer to recover detailed structure in the circumstellar material. In this thesis I present work on the interpretation of SAM interferometry data on protoplanetary discs through the simulation of a number of scenarios expected to be commonly seen, and the application of this technique to a number of objects. Analysing data taken as part of a SAM survey of transitional and pre-transitional discs using the Keck-II/NIRC2 instrument, I detected three companion candidates within the discs of DM Tau, LkHα 330, and TW Hya, and resolved a gap in the disc around FP Tau as indicated by flux from the disc rim. The location of all three of the companions detected as part of the survey are positioned in interesting regions of their parent discs. The candidate, LkHα 330 b is a potentially cavity opening companion due to its close radial proximity to the inner rim of the outer disc. DM Tau b is located immediately outside of a ring of dusty material largely responsible for the NIR comment of the disc SED, similar to TW Hya b located in a shallow gap in the dust disc outside another ring of over-dense dusty material which bounds a deep but narrow gap. Both of these companion candidates maybe migrating cores which are feeding from the enriched ring of material. I conducted a more extensive study of the pre-transitional disc, V1247 Ori, covering three epochs and the H-, K- and L-wavebands. Complementary observations with VLT/SPHERE in Hα and continuum plus SMA observations in CO (2-1) and continuum were performed. The orientation and geometry of the outer disc was recovered with the SMA data and determine the direction of rotation. We image the inner rim of the outer disc in L-band SAM data, recovering the rim in all three epochs. Combining all three data sets together we form a detailed image of the rim. In H- and K-band SAM data we observe the motion of a close-in companion candidate. This motion was found to be too large to be adequately explained through a near-circular Keplerian orbit within the plane of the disc around the central star. Hence an alternate hypothesis had to be developed. I postulated that the fitted position of the companion maybe influenced by the emission from the disc rim seen in the L-band SAM data. I constructed a suite of model SAM data sets of a companion and a disc rim and found that under the right conditions the fitted separation of a companion will be larger than the true separation. Under these conditions we find the motion of the companion candidate to be consistent with a near-circular Keplerian orbit within the plane of the disc at a semi-major axis of ˜6 au. The Hα data lack the necessary resolution to confirm the companion as an accreting body, but through the high contrast sensitivities enabled by the state of the art SPHERE instrument I was able to rule out any other accreting body within the gap, unless deeply embedded by the sparse population of MIR emitting dust grains previously inferred to reside within the gap. Through the combination of SAM and SMA data we constrain the 3-D orientation of the disc, and through multi-wavelength SAM observation identify a close-in companion potentially responsible for the gap clearing and asymmetric arm structures seen in previous observations of this target. During my PhD I have contributed to the field of planet formation through the identification of four new candidate protoplanets observed in the discs of pre-main sequence stars. To do so I have quantified the confidence levels of companion fits to SAM data sets and formed synthetic data from models of asymmetric structures seen in these discs. I have described for the first time the effects of extended sources of emission on the fitted results of companion searches within interferometric data sets. I have combined SAM data sets from two separate telescopes with different apertures and masks to produce reconstructed image of an illuminated disc rim with superior uv-cover! age. I have used the expertise I have developed in this field to contribute to a number of other studies, including the study of the young star TYC 8241 2652 1, resulting in the rejection of a sub-stellar companion as the cause of the rapid dispersal of the star`s disc. The companion candidates I have identified here should be followed up to confirm their presence and nature as accreting protoplanets. Objects such as these will provide the opportunity for more detailed study of the process of planet formation in the near future with the next generation of instruments in the JWST and E-ELT.

Effect of CdS Growth Time on the Optical Properties of One-Pot Preparation of CdS-Ag2S Binary Compounds

NASA Astrophysics Data System (ADS)

Karimipour, M.; Izadian, L.; Molaei, M.

2018-02-01

CdS-Ag2S binary nanoparticles were synthesized using a facile one-pot microwave irradiation method. The effect of initial nucleation of CdS quantum dots (QDs) using 3 min, 5 min, and 7 min of microwave irradiation on the optical properties of the final compound was studied. The composition and crystal structure of the compounds were verified using energy dispersive x-ray spectroscopy and x-ray diffraction. They revealed that existence of Ag and Cd elements with an atomic ratio of 0.19 crystalizes in the form of monoclinic Ag2S and hexagonal CdS. Scanning electron microscope images showed a spherical morphology of the resultant compound, and transmission electron microscope images showed the formation of fine particles of CdS-Ag2S composites with an average size of 5-7 nm and 10-14 nm for CdS and Ag2S, respectively. Photoluminescence spectroscopy revealed that the initial growth time of CdS has a crucial effect on the emission of binary compounds such that for 3 min and 5 min of irradiation of CdS solution, the binary compound obtains strong red and considerable near-IR emission (850 nm), but for longer time, it rapidly quenches. The results indicate that the strong red emission can be tuned from 600 nm up to 700 nm with prolonging nucleation time of CdS. This study also emphasized that the origin of red emission strongly depends on the size and defects created in the CdS QDs.

Reducing Risk with Clinical Decision Support

PubMed Central

Maloney, F.L.; Feblowitz, J.; Samal, L.; Sato, L.; Wright, A.

2014-01-01

Summary Objective Identify clinical opportunities to intervene to prevent a malpractice event and determine the proportion of malpractice claims potentially preventable by clinical decision support (CDS). Materials and Methods Cross-sectional review of closed malpractice claims over seven years from one malpractice insurance company and seven hospitals in the Boston area. For each event, clinical opportunities to intervene to avert the malpractice event and the presence or absence of CDS that might have a role in preventing the event, were assigned by a panel of expert raters. Compensation paid out to resolve a claim (indemnity), was associated with each CDS type. Results Of the 477 closed malpractice cases, 359 (75.3%) were categorized as substantiated and 195 (54%) had at least one opportunity to intervene. Common opportunities to intervene related to performance of procedure, diagnosis, and fall prevention. We identified at least one CDS type for 63% of substantiated claims. The 41 CDS types identified included clinically significant test result alerting, diagnostic decision support and electronic tracking of instruments. Cases with at least one associated intervention accounted for $40.3 million (58.9%) of indemnity. Discussion CDS systems and other forms of health information technology (HIT) are expected to improve quality of care, but their potential to mitigate risk had not previously been quantified. Our results suggest that, in addition to their known benefits for quality and safety, CDS systems within HIT have a potential role in decreasing malpractice payments. Conclusion More than half of malpractice events and over $40 million of indemnity were potentially preventable with CDS. PMID:25298814

Key principles for a national clinical decision support knowledge sharing framework: synthesis of insights from leading subject matter experts

PubMed Central

Hongsermeier, Tonya; Wright, Adam; Lewis, Janet; Bell, Douglas S; Middleton, Blackford

2013-01-01

Objective To identify key principles for establishing a national clinical decision support (CDS) knowledge sharing framework. Materials and methods As part of an initiative by the US Office of the National Coordinator for Health IT (ONC) to establish a framework for national CDS knowledge sharing, key stakeholders were identified. Stakeholders' viewpoints were obtained through surveys and in-depth interviews, and findings and relevant insights were summarized. Based on these insights, key principles were formulated for establishing a national CDS knowledge sharing framework. Results Nineteen key stakeholders were recruited, including six executives from electronic health record system vendors, seven executives from knowledge content producers, three executives from healthcare provider organizations, and three additional experts in clinical informatics. Based on these stakeholders' insights, five key principles were identified for effectively sharing CDS knowledge nationally. These principles are (1) prioritize and support the creation and maintenance of a national CDS knowledge sharing framework; (2) facilitate the development of high-value content and tooling, preferably in an open-source manner; (3) accelerate the development or licensing of required, pragmatic standards; (4) acknowledge and address medicolegal liability concerns; and (5) establish a self-sustaining business model. Discussion Based on the principles identified, a roadmap for national CDS knowledge sharing was developed through the ONC's Advancing CDS initiative. Conclusion The study findings may serve as a useful guide for ongoing activities by the ONC and others to establish a national framework for sharing CDS knowledge and improving clinical care. PMID:22865671

Studies on growth mechanism and physical properties of hydrothermally synthesized CdS with novel hierarchical superstructures and their photocatalytic activity

NASA Astrophysics Data System (ADS)

Jamble, Shweta N.; Ghoderao, Karuna P.; Kale, Rohidas B.

2018-03-01

A simple, facile and organic-free hydrothermal method was utilized to synthesize cadmium sulfide (CdS) superstructures. The cadmium chloride and thiourea used as a Cd2+ and S2- ion sources for the growth of CdS superstructures. The reaction was carried out at different time and temperatures. The X-ray diffraction studies confirmed that the obtained products were highly crystalline with hexagonal phase. Scanning and transmission electron microscopy images reveal a monodisperse dendrite-like CdS superstructure. It consisted of a central long trunk with secondary branches, lying parallel to each other and making a certain angle with the central trunk, and small ternary branches grew out of the secondary branches. The selected area electron diffraction altogether with high-resolution electron microscopy patterns depicted that the leaves of dendrite were single crystalline in nature and preferentially grown along (111) direction. The UV-vis absorbance and photoluminescence study illustrated that the hierarchically grown CdS superstructures revealed the good quality of optical properties. A probable growth mechanism for the formation of CdS dendritic superstructures was also discussed and demonstrated by experimental results. The photocatalytic activity of CdS superstructures was studied with the photodegradation of methylene blue (MB) in an aqueous solution, under the visible light irradiation. The results showed that the degradation ratio of MB could reach 94.93% in 220 min. Based on the results, the possible mechanism of the photocatalytic reaction of MB with CdS dendrites is useful for visible light photocatalytic applications.

Surface and interface of epitaxial CdTe film on CdS buffered van der Waals mica substrate

DOE PAGES

Yang, Y. -B.; Seewald, L.; Mohanty, Dibyajyoti; ...

2017-03-31

We report single crystal CdTe films are desirable for optoelectronic device applications. An important strategy of creating films with high crystallinity is through epitaxial growth on a proper single crystal substrate. We report the metalorganic chemical vapor deposition of epitaxial CdTe films on the CdS/mica substrate. The epitaxial CdS film was grown on a mica surface by thermal evaporation. Due to the weak van der Waals forces, epitaxy is achieved despite the very large interface lattice mismatch between CdS and mica (~21–55%). The surface morphology of mica, CdS and CdTe were quantified by atomic force microscopy. The near surface structures, orientations and texture of CdTe and CdS films were characterized by the unique reflection high-energy electron diffraction surface pole figure technique. The interfaces of CdTe and CdS films and mica were characterized by X-ray pole figure technique and transmission electron microscopy. The out-of-plane and in-plane epitaxy of the heteroepitaxial films stack are determined to be CdTe(111)//CdS(0001)//mica(001) and [more » $$\\overline{1}2\\overline{1}$$] CdTe//[$$\\overline{1}100$$] CdS//[010] mica, respectively. The measured photoluminescence (PL), time resolved PL, photoresponse, and Hall mobility of the CdTe/CdS/mica indicate quality films. Finally, the use of van der Waals surface to grow epitaxial CdTe/CdS films offers an alternative strategy towards infrared imaging and solar cell applications.« less

Surface and interface of epitaxial CdTe film on CdS buffered van der Waals mica substrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Y. -B.; Seewald, L.; Mohanty, Dibyajyoti

We report single crystal CdTe films are desirable for optoelectronic device applications. An important strategy of creating films with high crystallinity is through epitaxial growth on a proper single crystal substrate. We report the metalorganic chemical vapor deposition of epitaxial CdTe films on the CdS/mica substrate. The epitaxial CdS film was grown on a mica surface by thermal evaporation. Due to the weak van der Waals forces, epitaxy is achieved despite the very large interface lattice mismatch between CdS and mica (~21–55%). The surface morphology of mica, CdS and CdTe were quantified by atomic force microscopy. The near surface structures, orientations and texture of CdTe and CdS films were characterized by the unique reflection high-energy electron diffraction surface pole figure technique. The interfaces of CdTe and CdS films and mica were characterized by X-ray pole figure technique and transmission electron microscopy. The out-of-plane and in-plane epitaxy of the heteroepitaxial films stack are determined to be CdTe(111)//CdS(0001)//mica(001) and [more » $$\\overline{1}2\\overline{1}$$] CdTe//[$$\\overline{1}100$$] CdS//[010] mica, respectively. The measured photoluminescence (PL), time resolved PL, photoresponse, and Hall mobility of the CdTe/CdS/mica indicate quality films. Finally, the use of van der Waals surface to grow epitaxial CdTe/CdS films offers an alternative strategy towards infrared imaging and solar cell applications.« less