1,720,987 research outputs found
Hydrogen sulfide: A worthwhile tool in the design of new multitarget drugs
Full text linkH2S is a gaseous molecule able to trigger a plethora of central physiological and pharmacological effects as antioxidant, pro- and anti-inflammatory, pro- and anti-nociceptive, neuromodulator, and cytoprotective. The polypharmacology of H2S depends on the wide variety of targets implicated, but, despite the efforts, the mechanisms of action that should clarify its activity are still not completely unrevealed. Nevertheless, many attempts to exploit the multifaceted profile of this molecule have already been accomplished and many chemical entities containing an H2S-releasing pharmacophore have been synthetized. Here we discuss recent investigations on multitarget molecules able to release H2S, with a particular focus on the combinations of "native drug" with moieties structurally able to release H2S and their applications as therapeutic tools in bone disease, gastrointestinal system and neurodegenerative disorders
Dimer of rivastigmine and caffeic acid or ferulic acid, preparation method and drug composition thereof
No full textThe present invention relates to synthesis of a series of rivastigmine derivatives, wherein the structural formula is represented by a formula (I). According to the present invention, with the substituent changing, the inhibition of acetylcholine/butyrylcholine esterase by adjusting the rivastigmine derivatives, the inhibition of glutamic acid-induced oxidative stress, the reduction of damage of H2O2 and other ROS on HT22 cells, the inhibition of beta-amyloid protein self-aggregation, and the clearing of DPPH free radicals, the rivastigmine derivatives can simultaneously act on multiple targets. The rivastigmine derivatives can be made into the suitable pharmaceutical dosage form for Alzheimer's disease treatment
A review on the hybrids of hydroxycinnamic acid as multi-target-directed ligands against Alzheimer's disease
No full textAlzheimer's disease (AD), a complex chronic progressive central nervous system degenerative disease and a public health problem of the world, often characters cognitive dysfunction accompaning aggression and depression, and may lead to death. More attentions should be paid on it because there is no modified strategy against AD till now. AD is featured with the loss of cholinergic neurons, the amyloid-beta peptide (AÎ2) plaques and the neurofibrillary tangles and several hypotheses were established to explain the pathogenesis of AD. Hydroxycinnamic acids, including caffeic acid (CA) and ferulic acid (FA) are widely distributed in natural plants and fruits. CA and FA exert various pharmacological activities, including anti-inflammatory, antioxidant, neuroprotection, anti-amyloid aggregation and so on. All these pharmacological activities are associated with the treatment of AD. Here we summarized the pharmacological activities of CA and FA, and their hybrids as multi-target-directed ligands (MTDLs) against AD. The future application of CA and FA was also discussed, hoping to provide beneficial information for the development of CA- and FA-based MTDLs against AD
Multi-targeted ChEI-copper chelating molecules as neuroprotective agents
No full textThe identification of a valid therapeutic treatment for Alzheimer's disease (AD)represents nowadays an urgent and still unmet medical need, since currently available anti-AD drugs only relieve symptoms and show a modest efficacy. Recent evidence indicates that multi-target-directed ligands (MTDLs)can potentially provide an effective strategy to develop innovative therapies directed towards the onset and progression of this multifactorial neurodegenerative disorder. In this work we designed, synthesized and evaluated a new series of MTDLs bearing the rivastigmine skeleton (ChE-inhibitor)linked to known metal-chelating moieties with linkers of different length. For all the novel derivatives, AChE/BuChE inhibitory activity, ROS scavenging activity and potential cytotoxicity have been assessed. For the best compound (4), copper chelating properties and neuroprotective effects were also evaluated. Our data demonstrated that hybrid derivative 4 is able to effectively inhibit AChE and BuChE and to chelate copper, showing a protective action on neurons. These results, although preliminary, indicate that compound 4 can be considered as a possible hit molecule for the development of new anti-AD MTDLs
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
Synthesis and pharmacological evaluation of multifunctional tacrine derivatives against several disease pathways of AD
Full text linkA novel series of tacrine derivatives were designed and synthesized by combining caffeic acid (CA), ferulic
acid (FA) and lipoic acid (LA) with tacrine. The antioxidant study revealed that all the hybrids have much
more antioxidant capacities compared to CA. Among these compounds, 1b possessed a good ability to
inhibit the b-amyloid protein (Ab) self-aggregation, sub-micromole acetylcholinesterase (AChE)/butyrylcholinesterase
(BuChE) inhibitory, modest BACE1 inhibitory. Moreover, compound 1b also was a DPPH
radical scavenger and copper chelatory as well as had potent neuroprotective effects against glutamateinduced
cell death with low toxicity in HT22 cells. Our findings suggest that the compound 1b might be a
promising lead multi-targeted ligand and worthy of further developing for the therapy of Alzheimer’s
disease
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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