220 research outputs found
Anti-inflammatory and Analgesic Activities of Amorphophallus bulbifer (Roxb) Kunth Whole Plant
Purpose: To investigate the anti-inflammatory and analgesic activities of the Amorphophallus Bulbifer in Wistar rats and mice.Methods: The anti-inflammatory activity of the hydroalcohol extract of A. bulbifer whole plant at dose levels of 100 and 200 mg/kg p.o. in rats was determined with a plethysmograph paw volume difference of the animals pre- and post-treatment. Ibuprofen (10 mg/kg) was employed as reference standard. Analgesic activity was evaluated using tail flick and tail immersion techniques, by measuring the reaction time of the animals treated with either standard or extract. Pentazocin (30 mg/kg) was used as reference standard.Results: The extract showed significant anti-inflammatory and analgesic activities at the two test dose levels at the 4th hour (p < 0.001). The extract exhibited anti inflammatory activity of 56.5 (p < 0.001) and57.1 % (p < 0.001) inhibition compared to the control group in the carrageenan and histamine-induced inflammation model at a dose of 200 mg/kg. For analgesic activity, the extract showed reaction times of7.33 (p < 0.001) and 7.83 (p < 0.001) min in the tail flick and tail immersion models, respectively, at a dose of 200 mg/kg while the normal and reference groups exhibited reaction times of 2.16, 2.66 and8.16 (p < 0.001) and 8.5 (p < 0.001) in the tail flick and tail immersion methods, respectively.Conclusion: Based on the findings, it can be concluded that Amorphophallus bulbifer possesses antiinflammatory and analgesic properties and this lends some support for its use in traditional medicalpractice.Keywords: Amorphophallus bulbifer, Anti-inflammatory activity, Analgesic activit
A New Approach to Measuring Distances in Dense Graphs
The problem of computing distances and shortest paths between vertices in graphs is one of the fundamental issues in graph theory. It is of great importance in many different applications, for example, transportation, and social network analysis. However, efficient shortest distance algorithms are still desired in many disciplines. Basically, the majority of dense graphs have ties between the shortest distances. Therefore, we consider a different approach and introduce a new measure to solve all-pairs shortest paths for undirected and unweighted graphs. This measures the shortest distance between any two vertices by considering the length and the number of all possible paths between them. The main aim of this new approach is to break the ties between equal shortest paths SP, which can be obtained by the Breadth-first search algorithm (BFS), and distinguish meaningfully between these equal distances. Moreover, using the new measure in clustering produces higher quality results compared with SP. In our study, we apply two different clustering techniques: hierarchical clustering and K-means clustering, with four different graph models, and for a various number of clusters. We compare the results using a modularity function to check the quality of our clustering results
Data Mining for Thermal Analysis of Big Dataset of HPC-Data Center
Greening of Data Centers could be achieved through energy savings in two major areas namely: compute systems and cooling systems. A reliable cooling system is necessary to produce a persistent flow of cold air to cool the servers due to increasingly demanding computational load. Servers’ dissipated heat effects a strain on the cooling systems. Consequently, it is imperative to individual servers that frequently occur in the hotspot zones. This is facilitated through the application of data mining techniques to an available big data set with thermal characteristics of HPC-ENEA-Data Center, namely Cresco 6. This work involves the implementation of an advanced algorithm on the workload management platform produces hotspots maps with the goal to reduce data centre wide thermal-gradient, and cooling effectiveness
Long-term coding of personal and universal associations underlying the memory web in the human brain
Neurons in the medial temporal lobe (MTL), a critical area for declarative memory, have been shown to change their tuning in associative learning tasks. Yet, it is unclear how durable these neuronal representations are and if they outlast the execution of the task. To address this issue, we studied the responses of MTL neurons in neurosurgical patients to known concepts (people and places). Using association scores provided by the patients and a web-based metric, here we show that whenever MTL neurons respond to more than one concept, these concepts are typically related. Furthermore, the degree of association between concepts could be successfully predicted based on the neurons’ response patterns. These results provide evidence for a long-term involvement of MTL neurons in the representation of durable associations, a hallmark of human declarative memory
Oxidation of benzoin catalyzed by oxovanadium (IV) schiff base complexes
BACKGROUND: The oxidative transformation of benzoin to benzil has been accomplished by the use of a wide
variety of reagents or catalysts and different reaction procedures. The conventional oxidizing agents yielded mainly
benzaldehyde or/and benzoic acid and only a trace amount of benzil. The limits of practical utilization of these
reagents involves the use of stoichiometric amounts of corrosive acids or toxic metallic reagents, which in turn
produce undesirable waste materials and required high reaction temperatures.
In recent years, vanadium complexes have attracted much attention for their potential utility as catalysts for various
types of reactions.
RESULTS: Active and selective catalytic systems of new unsymmetrical oxovanadium(IV) Schiff base complexes for
the oxidation of benzoin is reported. The Schiff base ligands are derived between 2-aminoethanol and 2-hydroxy-1-
naphthaldehyde (H2L1) or 3-ethoxy salicylaldehyde (H2L3); and 2-aminophenol and 3-ethoxysalicylaldehyde (H2L2) or
2-hydroxy-1-naphthaldehyde (H2L4). The unsymmetrical Schiff bases behave as tridentate dibasic ONO donor
ligands. Reaction of these Schiff base ligands with oxovanadyl sulphate afforded the mononuclear oxovanadium(IV)
complexes (VIVOLx.H2O), which are characterized by various physico-chemical techniques.
The catalytic oxidation activities of these complexes for benzoin were evaluated using H2O2 as an oxidant. The best
reaction conditions are obtained by considering the effect of solvent, reaction time and temperature. Under the
optimized reaction conditions, VOL4 catalyst showed high conversion (>99%) with excellent selectivity to benzil
(~100%) in a shorter reaction time compared to the other catalysts considered.
CONCLUSION: Four tridentate ONO type Schiff base ligands were synthesized. Complexation of these ligands with
vanadyl(IV) sulphate leads to the formation of new oxovanadium(IV) complexes of type VIVOL.H2O.
Elemental analyses and spectral data of the free ligands and their oxovanadium(IV) complexes were found to be in
good agreement with their structures, indicating high purity of all the compounds.
Oxovanadium complexes were screened for the oxidation of benzoin to benzil using H2O2 as oxidant. The effect of
time, solvent and temperature were optimized to obtain maximum yield. The catalytic activity results demonstrate
that these catalytic systems are both highly active and selective for the oxidation of benzoin under mild reaction
conditions.Web of Scienc
Peroxisomal alterations in Alzheimer’s disease
In Alzheimer’s disease (AD), lipid alterations are present early during disease progression. As some of these alterations point towards a peroxisomal dysfunction, we investigated peroxisomes in human postmortem brains obtained from the cohort-based, longitudinal Vienna-Transdanube Aging (VITA) study. Based on the neuropathological Braak staging for AD on one hemisphere, the patients were grouped into three cohorts of increasing severity (stages I–II, III–IV, and V–VI, respectively). Lipid analyses of cortical regions from the other hemisphere revealed accumulation of C22:0 and very long-chain fatty acids (VLCFA, C24:0 and C26:0), all substrates for peroxisomal β-oxidation, in cases with stages V–VI pathology compared with those modestly affected (stages I–II). Conversely, the level of plasmalogens, which need intact peroxisomes for their biosynthesis, was decreased in severely affected tissues, in agreement with a peroxisomal dysfunction. In addition, the peroxisomal volume density was increased in the soma of neurons in gyrus frontalis at advanced AD stages. Confocal laser microscopy demonstrated a loss of peroxisomes in neuronal processes with abnormally phosphorylated tau protein, implicating impaired trafficking as the cause of altered peroxisomal distribution. Besides the original Braak staging, the study design allowed a direct correlation between the biochemical findings and the amount of neurofibrillary tangles (NFT) and neuritic plaques, quantified in adjacent tissue sections. Interestingly, the decrease in plasmalogens and the increase in VLCFA and peroxisomal volume density in neuronal somata all showed a stronger association with NFT than with neuritic plaques. These results indicate substantial peroxisome-related alterations in AD, which may contribute to the progression of AD pathology
A Concerted Kinase Interplay Identifies PPARγ as a Molecular Target of Ghrelin Signaling in Macrophages
The peroxisome proliferator-activator receptor PPARγ plays an essential role in vascular biology, modulating macrophage function and atherosclerosis progression. Recently, we have described the beneficial effect of combined activation of the ghrelin/GHS-R1a receptor and the scavenger receptor CD36 to induce macrophage cholesterol release through transcriptional activation of PPARγ. Although the interplay between CD36 and PPARγ in atherogenesis is well recognized, the contribution of the ghrelin receptor to regulate PPARγ remains unknown. Here, we demonstrate that ghrelin triggers PPARγ activation through a concerted signaling cascade involving Erk1/2 and Akt kinases, resulting in enhanced expression of downstream effectors LXRα and ABC sterol transporters in human macrophages. These effects were associated with enhanced PPARγ phosphorylation independently of the inhibitory conserved serine-84. Src tyrosine kinase Fyn was identified as being recruited to GHS-R1a in response to ghrelin, but failure of activated Fyn to enhance PPARγ Ser-84 specific phosphorylation relied on the concomitant recruitment of docking protein Dok-1, which prevented optimal activation of the Erk1/2 pathway. Also, substitution of Ser-84 preserved the ghrelin-induced PPARγ activity and responsiveness to Src inhibition, supporting a mechanism independent of Ser-84 in PPARγ response to ghrelin. Consistent with this, we found that ghrelin promoted the PI3-K/Akt pathway in a Gαq-dependent manner, resulting in Akt recruitment to PPARγ, enhanced PPARγ phosphorylation and activation independently of Ser-84, and increased expression of LXRα and ABCA1/G1. Collectively, these results illustrate a complex interplay involving Fyn/Dok-1/Erk and Gαq/PI3-K/Akt pathways to transduce in a concerted manner responsiveness of PPARγ to ghrelin in macrophages
The peroxisome: still a mysterious organelle
More than half a century of research on peroxisomes has revealed unique features of this ubiquitous subcellular organelle, which have often been in disagreement with existing dogmas in cell biology. About 50 peroxisomal enzymes have so far been identified, which contribute to several crucial metabolic processes such as β-oxidation of fatty acids, biosynthesis of ether phospholipids and metabolism of reactive oxygen species, and render peroxisomes indispensable for human health and development. It became obvious that peroxisomes are highly dynamic organelles that rapidly assemble, multiply and degrade in response to metabolic needs. However, many aspects of peroxisome biology are still mysterious. This review addresses recent exciting discoveries on the biogenesis, formation and degradation of peroxisomes, on peroxisomal dynamics and division, as well as on the interaction and cross talk of peroxisomes with other subcellular compartments. Furthermore, recent advances on the role of peroxisomes in medicine and in the identification of novel peroxisomal proteins are discussed
Comparative Genomics of Cell Envelope Components in Mycobacteria
Mycobacterial cell envelope components have been a major focus of research due to their unique features that confer intrinsic resistance to antibiotics and chemicals apart from serving as a low-permeability barrier. The complex lipids secreted by Mycobacteria are known to evoke/repress host-immune response and thus contribute to its pathogenicity. This study focuses on the comparative genomics of the biosynthetic machinery of cell wall components across 21-mycobacterial genomes available in GenBank release 179.0. An insight into survival in varied environments could be attributed to its variation in the biosynthetic machinery. Gene-specific motifs like ‘DLLAQPTPAW’ of ufaA1 gene, novel functional linkages such as involvement of Rv0227c in mycolate biosynthesis; Rv2613c in LAM biosynthesis and Rv1209 in arabinogalactan peptidoglycan biosynthesis were detected in this study. These predictions correlate well with the available mutant and coexpression data from TBDB. It also helped to arrive at a minimal functional gene set for these biosynthetic pathways that complements findings using TraSH
Approaches in biotechnological applications of natural polymers
Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)
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