1,720,988 research outputs found
The investigation of cancer treatments effects on electrophysiological properties of cells by DEP with respect to personalised and stratified medicine.
Get PDFWhilst personalized medicine (where interventions are precisely tailored to a patient’s genotype and phenotype, as well as the nature and state of the disease) is regarded as an optimal form of treatment, the time and cost associated with it means it remains inaccessible to the greater public. Stratified medicine offers an option with many of the benefits without the associated costs; rather than treatments being unique to an individual, patients are grouped (stratified) according to whether they respond to a given treatment, allowing the treatment to be selected from an appropriate panel, and avoiding the common “trial and error” approach of replacing a therapy only once it is demonstrated to be ineffective in the patient. For stratification to be effective, it is necessary to develop tests that can rapidly assess whether a treatment will be effective. Here we examine the use of dielectrophoresis to determine whether cancer drugs like Iressa, Cisplatin and MTX (metateroxide) are efficatious by treating cancer cell lines (one expressing EGFR, one not) with the drug Iressa, which indicates discernable difference. We also examine the use in assessing the efficacy of combination therapies, including both chemotherapeutic and radiotherapeutic interventions. Results suggest that a DEP-based assay could potentially be used in a standard pathology laboratory setting, where biopsy cells can be screened at low cost and high speed, enabling the selection of an appropriate course of treatment from the outset, increasing patient survival rates whilst reducing time and cost for the health provider. K562 is suspension cell line, butHN5 and T47D cell lines are both adherent cells and need to be detached before any experiment. Prior to the investigation of cancer treatments, the effect of various detachment methods on these cell lines were studied to find out whether these methods could impact the electrophysiological properties of the cells. The results in investigation of detachment methods exhibit that unlike chemical substances, a harvesting method significantly alters the values of dielectric parameters
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
The application of dielectrophoresis in cell cycle studies.
Get PDFThe cell cycle is the process of tightly integrated events leading to cell growth, DNA replication and cell division. Cell cycle dysregulation is the common reason for abnormal cell growth (cancer) and therefore, scientists are interested in determining the proportion of cells in each cell cycle phase for effective targeting of cancerous cells at a specific phase.
Knowledge of cells’ electrophysiological properties can provide new insights in cell cycle events studies. Dielectrophoresis (DEP) is a technique that can be used to obtain these properties for cell characterisation. DEP is a fast, label-free, high-throughput, and cost-effective micro-engineered technology that reduces the sample volume and provides automated real-time analysis.
This thesis explores the application of the DEP-microwell electrode system (both the serial design and the parallel integrated system) in cell cycle analysis. It also investigates the variation of cellular electrophysiological properties (particularly the effective membrane capacitance (ceff), the effective membrane conductance (geff) and the cytoplasmic conductivity (σ_CP)) during different phases through the cell cycle, in vitro. In addition, this work assesses the relation between the intracellular DNA percentage in each phase and the acquired DEP data to find out the possible correlation between cell cycle phases and cellular electrophysiological properties.
For the purpose of having the cells at different stages of the cycle, a K562 cell line was synchronised at G0/G1, late G1/S and early S-phase, using serum starvation (SS), hydroxyurea (HU) and aphidicolin (APH). DEP measurements were carried out for cells before treatment (control cells), immediately after treatment (0h-study) and at 2, 4 and 24 hours after releasing the cells back to the culture medium for each synchronisation method. Due to improved time resolution and frequency range in the parallel design of DEP-microwell electrode, acquired results of this method showed more accurate data.
The obtained results demonstrated significant difference of electrophysiological properties through different phases of K562 cell cycle. Using the parallel design:
σ_CP at 0h-study: σ_CP (SS) greater than σ_CP (HU) and σ_CP (APH) by ~50% and ~60%, respectively
geff at 0h-study: geff (HU) greater than geff (APH) and geff (SS) by ~90% and ~65%, respectively
ceff at 0h-study: ceff (HU) ≈ ceff (APH), both greater than ceff (SS) by ~22%
In summary, results showed that a rising pattern for cell radii, a downward followed by an upward trend in σ_CP values, a falling followed by a rising pattern for ceff value, and a rising pattern for geff values were observed during the cell cycle. Furthermore, the change of these electrophysiological properties correlated with the proposed trends at different phases of the cell cycle. This suggests that the DEP-microwell electrode system can be used as an innovative, real-time, portable, cost-effective and high-throughput approach for cell characterisation at particular stages of the cell cycle
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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