1,720,955 research outputs found
Inorganic–organic core/shell nanoparticles: progress and applications
No full textIn recent decades a great deal of research has been dedicated to the development of core-shell nanoparticles (NPs). We decided to focus our attention on NPs with inorganic cores and organic shells and divide them by area of application such as electrical applications, drug delivery, biomedical applications, imaging, chemistry and catalysis. Organic shells, consisting in most cases of polymers (natural or synthetic), proteins or complex sugars, can improve the performance of inorganic NPs by enhancing their biocompatibility, acting as anchor sites for molecular linkages or protecting them from oxidation. Moreover, suitable design of the shell thickness can improve the chemical and thermal stability of NPs together with the possibility of tuning and controlling the release of molecules from the core. In the future new discoveries will guarantee improvement in the properties of NPs, synthesis, and applications of this class of nanomaterials that are constantly evolving
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
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
Surface tension assisted devices for drugs and cells delivery using hydrogels
Get PDFLAUREA MAGISTRALEIl settore del “drug delivery” è una branca in costante sviluppo e ricerca da parte della comunità scientifica, grazie all'utilità nella vita pratica per i trattamenti delle malattie, la rigenerazione dei tessuti, il rilascio di terapie su misura. Anche la consegna “in loco” delle cellule è un campo profondamente studiato, in particolare per i trattamenti anti-tumorali e la guarigione delle ferite.
Questi obiettivi possono essere raggiunti utilizzando combinazioni di soluzioni diverse o sfruttando materiali compositi, costituiti da due o più componenti diversi con proprietà chimiche o fisiche distinte di altri due o più sistemi. Ciò consente di sfruttare le migliori caratteristiche da una più grande quantità di tecnologie.
In questo lavoro abbiamo studiato gli usi dei dispositivi stampati in 3D che, grazie alla tensione superficiale, possono essere saldamente rivestiti con idrogels contenenti farmaci o cellule. L'obiettivo è quello di avere sia la consegna in uno specifico punto di diversi tipi di cellule sia il rilascio basato sulla diffusione di farmaci idrofili e idrofobici caricati in una matrice idrofila o idrofoba.
Nel laboratorio di ingegneria macromolecolare dell’ ETH ZÜRICH, il supporto biocompatibile in policaprolattone è stato stampato in 3D e rivestito con due diversi idrogels, la gelatina metacrilata (GelMa) e l’alginato di sodio. Per quanto riguarda il supporto metallico, questo è stato stampato in resina DL60 dal + LAB del Politecnico di Milano e metallizzato dal SEE Lab del Politecnico di Milano, utilizzando la tecnica del layer by layer.
Per la parte del progetto riguardante il trasporto in loco di cellule, sono stati incapsulati fibroblasti NIH / 3T3 (ATCC® CRL-1658 TM) direttamente nell’hydrogel di GelMa. Per la parte relativa alla consegna dei farmaci invece, abbiamo caricato due tipi di molecole “modello”:
• Rodamina B, idrofila, caricata grazie a proprietà steriche
• Oil Red O, idrofobo, caricato sia nel GelMa che nell’alginato di sodio usando nanoparticelle polimeriche di polietilenglicole legate all'acido polilattico (nanoparticelle PEG-PLA).
La cinetica di crosslinking è stata valutata mediante analisi reologiche per entrambi i sistemi.
L'intero lavoro sperimentale è stato svolto presso l'ETH ZÜRICH.
Per ulteriori sperimentazioni, alla fine del progetto, abbiamo iniziato a sintetizzare, in fase liquida, la sequenza peptidica RGD (acido arginilglicilaspartico), in prospettiva futura di legarlo chimicamente alle molecole di alginato di sodio usando legami amidici, al fine di analizzare poi quale dei due sistemi tra GelMa e alginato di sodio sarebbe più indicato per il trasporto ed il supporto cellulare.The drug delivery field is a branch in continuous development and research by the scientific community, due to the utility in the practical life for disease treatments, tissue regeneration, tailored therapeutics releasing. Cells “in loco” delivery is also a deeply investigated field, especially for anti-tumour treatments and wound healing.
These objectives can be achieved using combinations of different solutions or exploiting composite materials, made of two or more different constituents with distinct chemical or physical properties of other two or more systems. This allows to exploit the best characteristics from a great quantities of technologies.
In this work we investigated the uses of 3D- printed devices, that thanks to superficial tension, can be tightly coated with drug or cells loaded hydrogels. The aim is to have both the on-target delivery of different types of cells and diffusion- based release of both hydrophilic and hydrophobic drugs loaded in a hydrophilic hydrogel matrix.
In the Macromolecular Engineering Laboratory of ETH ZÜRICH, the biocompatible support made of polycaprolactone has been 3D printed and coated with two different hydrogels, methacrylated gelatin (GelMa) and sodium alginate. Regarding the metallic support, this has been printed in DL60 resin by the +LAB of Politecnico di Milano and metallized by the SEE Lab of Politecnico di Milano, using the layer by layer teqnique.
Considering the cells delivery part, NIH/3T3 (ATCC® CRL-1658TM) fibroblasts have been encapsulated in GelMa. For the drug delivery part of the project we loaded two types of model drugs:
• Rhodamine B Isothiocyanate, hydrophilic, loaded thanks to steric phenomena
• Oil Red O, hydrophobic, loaded into GelMa and sodium alginate using polymeric nanoparticles of polyethylene glycol linked to polylactic acid (PEG-PLA Nanoparticles).
The crosslinking kinetic has been evaluated through rheologic analysis for both the systems.
The entire experimental work has been carried out at ETH ZÜRICH.
For further experimentation, at the end of the project, we started to synthesized, in liquid phase, the RGD peptide sequence (arginylglycylaspartic acid), with the future outlook of chemically linked it to the sodium alginate molecules using amidic bonds, in order to analyse which of the two systems between GelMa and sodium alginate would be better for cells delivery application. Sodium alginate does not naturally contain the RGD sequenced that enable the cells to attached to the hydrogel matrix
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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