1,721,032 research outputs found
Bacteria-template synthesized silver microspheres with hollow and porous structures as excellent SERS substrate
No full textTemplate-driven strategy is widely explored for the synthesis of nano/micro materials. Of all the templates studied, naturally occurring biological systems such as proteins, viruses and bacteria have attracted more attention due to the prolific sources and complex structural diversities. Herein, we report a simple bacteria templated synthesis of silver microspheres over a bottom-up controlled route. These as-prepared silver microspheres not only have narrow size distribution but possess hollow and porous structures. Surface enhanced Raman scattering (SERS) experiments using 2-mercaptopyridine (2-Mpy) as probing molecules show that these hollow porous microspheres can act as excellent substrate for ultrasensitive detecting. The detection limit is as low as 10(-15) M and the enhancement factor reaches to 10(11). Compared with other conventional SERS substrates, the reproducible, high sensitive and cost-effective Ag microspheres could become an ideal substrate choice for practical SERS application
A Multifunctional Ribonuclease-A-Conjugated CdTe Quantum Dot Cluster Nanosystem for Synchronous Cancer Imaging and Therapy
No full textCdTe quantum dot (QD) clusters are synthesized in the presence of RNase A, which acts as a biomolecular templating, agent under microwave irradiation. Red shifts of photoluminescence spectra of the denatured RNase A (dRNase A)-capping QD clusters (dRQDs) are detected during a fifty-day storage period at room temperature. Native RNase-A-associated dRQDs (R-dRQDs) are functionalized with cyclic RGD peptides for synchronous targeted cancer imaging and therapy. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Antibody-Drug Gold Nanoantennas with Raman Spectroscopic Fingerprints for in Vivo Tumour Theranostics
Get PDFInspired by the ability of SERS nanoantennas to provide an integrated platform to enhance disease targeting in vivo, we developed a highly sensitive probe for in vivo tumoral recognition with the capacity to target specific cancer biomarkers such as epidermal growth factor receptors (EGFR) on human cancer cells and xenograft tumour models. Here, we used ~90 nm gold nanoparticles capped by a Raman reporter, encapsulated and entrapped by larger polymers and a FDA antibody-drug conjugate –Cetuximab (Erbitux®) – that specifically targets EGFR and turns off a main signalling cascade for cancer cells to proliferate and survive. These drug/SERS gold nanoantennas present a high Raman signal both in cancer cells and in mice bearing xenograft tumours. Moreover, the Raman detection signal is accomplished simultaneously by extensive tumour growth inhibition in mice, making these gold nanoantennas ideal for cancer nanotheranostics, i.e. tumour detection and tumoral cell inhibition at the same time
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Fluoroimmunoassay for Antigen based on Fluorescence Quenching between Quantum Dots and Gold Nanoparticles
No full textA unique, sensitive, and highly specific fluoroimmunoassay system for antigen detection using gold and quantum dot nanoparticles has been developed. The assay is based on the fluorescence quenching of quantum dots caused by gold nanoparticles coated with antibody. To demonstrate its analytical capabilities, the CdTe quantum dots were coated with anti-HBsAg monoclonal antibodies (QDs-MAb1) and gold nanoparticles coated with another anti-HBsAg monoclonal antibodies (GNPs-MAb2) which specifically bound with HBsAg could sandwich the HBsAg captured by the immunoreactions. The sandwich-type immunocomplex was formed and the fluorescence intensity of quantum dots was measured. The results showed that the fluorescence intensity of quantum dots at 570 nm was negative linear proportional to the HBsAg concentration logarithm, and the limit of detection of the HBsAg was 0.928 ng/mL. This new system can be extended to detect target molecules with matched antibodies and has broad potential applications in immunoassay and disease diagnosis
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