1,721,010 research outputs found
Antimicrobial and genotoxic activities of N-(2-hydroxyethyl)-1,2-benzisothiazol-3(2H)-thione carbamic esters
No full textPatterns of calcium signaling: A link between chronic emotions and cancer
No full textIntra and inter-cellular calcium signaling is present in all types of cells and body tissues. In the human brain, calcium currents and waves are related to mental activities, including emotions. We present a theoretical interpretation of these phenomena suggesting their involvement in chronic emotional patterns and in the pathology of cancer. Recent developments on biophysics, translational biology and psychoneuroendocrinoimmunology (PNEI) can support explanatory hypotheses about the link between emotional stresses and the origin and development of different types of tumor cells. Chronic stresses may cause perturbations of rhythms of the PNEI system, excessive activation of HPA axis and abnormal activation of calcium signals in somatic tissues, with deleterious effects on different parts of the body. The increasing of calcium signaling inside cells may lead to a deregulation of different pathways and epigenetic systems that promote the production of genomic mutations in a second phase. In particular, the hyperactivation of the transcription nuclear factor kappaB (NF-κB), if is not counterbalanced by the following activation of the nuclear factor (erythroid-derived 2)-like 2 (NFE2L2 or Nrf2), increases the production of oxidative catabolites, as the advanced glycation end products (AGE), which play a key role in the progression of different types of cancer and other degenerative diseases. Cortisol binding to glucocorticoid receptor (GR) reduces the activity of both NF-κB and Nrf2 inside the cells but inhibits the cellular immunity and the anabolic processes of tissue regeneration. The tissue atrophy and the defective anti-ageing mechanisms promotes the tumoral cells growth and their escape from the immune-surveillance
SARS-CoV-2 spike and ACE2 entanglement-like binding
No full textWe describe the binding between the glycoprotein Spike of SARS-CoV-2 and the human host cell receptor ACE2 as a quantum circuit, comprising the one-qubit Hadamard quantum logic gate performing the quantum superposition of the S(1) subunit of the Spike protein, and the two-qubit quantum logic gate CNOT, which performs maximum entanglement between the Spike-qubit S(1) and the ACE2 receptor protein. Also, we consider two strategies to prevent the binding process between the Spike-qubit S(1) and the ACE2 receptor. The first one is the use of competitive peptidomimetic inhibitors that can selectively bind to the receptor binding domain (RBD) of the Spike glycoprotein with much higher affinity than the cell surface receptor itself. These inhibitors are targeted to the CNOT quantum logic gate and will get maximally entangled with the S(1) qubit in place of the natural ACE2 receptor. The second one is to use covalent inhibitors, which will destroy S(1) by acting as a projective quantum measurement. Finally, the conjecture that S(1) is a quantum bio-robot is formulated
A compendium of existing vulnerability and fragility relationships for flood: preliminary results
No full textIn the last decade, probabilistic approaches for flood risk assessment have emerged, often as an extension of more consolidated methods used in probabilistic seismic risk assessment. Nonetheless, only a few studies deal with best-practice methodologies for flood vulnerability assessment and existing approaches lack of an appropriate guidance for their selection. These concerns underline the need for a rational, integrated and complete compendium of all the existing flood-related vulnerability and fragility relationships to be used in a comprehensive probabilistic flood risk assessment framework. Following the same approach used in the guidelines recently developed by the Global Earthquake Model (GEM) Project, this paper presents a preliminary review of the state-of-art regarding existing empirical vulnerability and fragility curves in the context of flood risk. In particular, a worldwide overview is intended in terms of data sources, assets features and also statistical techniques employed for data collection and fitting. The research aims at providing a complete and flexible guide for selection of vulnerability and fragility curves for building structures. A discussion on data sources, building classification and considered features, and damage scales is presented, in order to evaluate the reliability, and at the same time the limitations, of different approaches and provide recommendation for future studies
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
New antibiotics for multidrug-resistant bacterial strains: Latest research developments and future perspectives
Full text linkThe present work aims to examine the worrying problem of antibiotic resistance and the emergence of multidrug-resistant bacterial strains, which have now become really common in hospitals and risk hindering the global control of infectious diseases. After a careful examination of these phenomena and multiple mechanisms that make certain bacteria resistant to specific antibiotics that were originally effective in the treatment of infections caused by the same pathogens, possible strategies to stem antibiotic resistance are analyzed. This paper, therefore, focuses on the most promising new chemical compounds in the current pipeline active against multidrug-resistant organisms that are innovative compared to traditional antibiotics: Firstly, the main antibacterial agents in clinical development (Phase III) from 2017 to 2020 are listed (with special attention on the treatment of infections caused by the pathogens Neisseria gonorrhoeae, including multidrug-resistant isolates, and Clostridium difficile), and then the paper moves on to the new agents of pharmacological interest that have been approved during the same period. They include tetracycline derivatives (eravacycline), fourth generation fluoroquinolones (delafloxacin), new combinations between one β-lactam and one β-lactamase inhibitor (meropenem and vaborbactam), siderophore cephalosporins (cefiderocol), new aminoglycosides (plazomicin), and agents in development for treating drug-resistant TB (pretomanid). It concludes with the advantages that can result from the use of these compounds, also mentioning other approaches, still poorly developed, for combating antibiotic resistance: Nanoparticles delivery systems for antibiotics
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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
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