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Biochar is a solid by-product of thermochemical conversion of biomass to bio-oil and syngas. It has a carbonaceous skeleton, a small amount of heteroatom functional groups, mineral matter, and water. Biochar’s unique physicochemi...
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Biochar is a solid by-product of thermochemical conversion of biomass to bio-oil and syngas. It has a carbonaceous skeleton, a small amount of heteroatom functional groups, mineral matter, and water. Biochar’s unique physicochemical structures lead to many valuable properties of important technological applications, including its sorption capacity. Indeed, biochar’s wide range of applications include carbon sequestration, reduction in greenhouse gas emissions, waste management, renewable energy generation, soil amendment, and environmental remediation. Aside from these applications, new scientific insights and technological concepts have continued to emerge in the last decade. Consequently, a systematic update of current knowledge regarding the complex nature of biochar, the scientific and technological impacts, and operational costs of different activation strategies are highly desirable for transforming biochar applications into industrial scales. This communication presents a comprehensive review of physical activation/modification strategies and their effects on the physicochemical properties of biochar and its applications in environment-related fields. Physical activation applied to the activation of biochar is discussed under three different categories: I) gaseous modification by steam, carbon dioxide, air, or ozone; II) thermal modification by conventional heating and microwave irradiation; and III) recently developed modification methods using ultrasound waves, plasma, and electrochemical methods. The activation results are discussed in terms of different physicochemical properties of biochar, such as surface area; micropore, mesopore, and total pore volume; surface functionality; burn-off; ash content; organic compound content; polarity; and aromaticity index. Due to the rapid increase in the application of biochar as adsorbents, the synergistic and antagonistic effects of activation processes on the desired application are also covered.
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The active ingredients (AI) tebuconazole and difenoconazole (classified as toxic to living organisms and potentially mutagen, carcinogen, or teratogen) are part of the composition of widely used fungicides in crops. In 2016 they w...
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The active ingredients (AI) tebuconazole and difenoconazole (classified as toxic to living organisms and potentially mutagen, carcinogen, or teratogen) are part of the composition of widely used fungicides in crops. In 2016 they were found in irregular quantities by ANVISA in their latest report emitted by the Program of Analysis of Agrochemical Waste in Food. Two commercial fungicides containing the active ingredients tebuconazole and difenoconazole were evaluated in cytogenotoxic assays and on different biological molecules. Both active ingredients altered the clotting time of the plasma, and were procoagulants in the majority of the evaluated doses. The two AI acted on blood thrombi exerting thrombotic action and confirming the observed procoagulant potential. In the proteolysis assay, the AI did not alter the structure of fibrinogen under the conditions evaluated. Tebuconazole and Difenoconazole were also cytotoxic to human erythrocytes, as well as induced phospholipid breakdown, confirming their toxicity on membranes. However, under the conditions evaluated, the AI did not alter significantly the mitochondrial succinate dehydrogenase activity and did not induce DNA fragmentation. Assuming that changes in human cells and molecules have a cumulative effect, the toxic potential of fungicides might be greater when chronic exposure to their active principles occurs.
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Pyranopyrazoles are bicyclic nitrogen-containing heterocycles having broadspectrum bioactivities, which may act as anti-cancer, anti-inflammatory, antibacterial, antifungal, insecticidal and molluscicidal agents. Pyranopyrazoles h...
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Pyranopyrazoles are bicyclic nitrogen-containing heterocycles having broadspectrum bioactivities, which may act as anti-cancer, anti-inflammatory, antibacterial, antifungal, insecticidal and molluscicidal agents. Pyranopyrazoles have become an attractive scaffold for the discovery of new drugs due to the diverse range of bioactivities associated with this nucleus. In this review, we have focused on the medicinal importance of pyranopyrazole derivatives and highlighted different routes for the synthesis of pyranopyrazole derivatives using inexpensive and commonly available starting materials.
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Many lignans and neolignans have served as lead compounds for the development of new drugs. Perhaps the best known example is podophyllotoxin, an antimitotic compound that binds to tubulin. Etoposide and tenipos-ide are derived fr...
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Many lignans and neolignans have served as lead compounds for the development of new drugs. Perhaps the best known example is podophyllotoxin, an antimitotic compound that binds to tubulin. Etoposide and tenipos-ide are derived from podophyllotoxin, but their antitumoural activity is due to inhibition of topoisomerase II. Combination of both pharmacophores has led to compounds with a dual mechanism of action, such as azatoxin. Dihydrobenzofuran neolignans, based on the natural lead 3',4-di-O-methylcedrusin, have also been investigated as potential antitumoural agents; the dimerisation product of caffeic acid methyl ester was the most active compound. Here too, he cytotoxic activity was due to inhibition of tubulin polymerisation. In addition, the same compounds showed antiangiogenic activity. Podophyllotoxin, as well as other types of lignans, such as dibenzylbutyrolactones related to arctigenin, dibenzocyclooctadiene-type lignans, and dibenzylbutanes, have been explored as leads for antiviral agents (also including HIV). Synthetic 8.0.4'-neolignans have been evaluated for their antileishmanial and antifungal properties. Detailed study of the antifungal properties of the phenylpropanoid moieties has resulted in the design of highly active arylpropanoid derivatives. Other examples where lignans have been used as lead compounds include enzyme inhibitors of phosphodiesterase IV and V, and 5-lipoxygenase, and for the development of hypolipidemic and antirheumatic agents.
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Activity-based travel demand models (ABM) have gained popularity during the last three decades and are currently in use in several urban areas. In ABM, special emphasis is given to modelling individuals' decisions related to parti...
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Activity-based travel demand models (ABM) have gained popularity during the last three decades and are currently in use in several urban areas. In ABM, special emphasis is given to modelling individuals' decisions related to participation in activity and its scheduling. Most researchers and popular ABM frameworks have, however, refrained from implicit activity participation decision modelling and have concentrated only on the activity scheduling part thus replacing 'activity' with 'tour' as the main focus of ABM. This may lead to oversimplification and may offset the need for ABMs in the first place. Thus there is a need to review research focusing on activity participation decisions to facilitate their incorporation and eventual strengthening of existing ABM frameworks. Accordingly, a critical review of activity generation focusing on conceptualization, modelling approaches and activity categorization is conducted to identify the lacunas towards making it more policy-sensitive, efficient and behaviourally realistic. The strength and weaknesses of different modelling techniques are also explored to understand their prediction accuracy and computational complexities. Additionally, the progress of activity participation decision modelling within the existing ABM frameworks is also traced. The existing models are also explored through the lens of changing activity-travel behaviour of urban commuters resulting from technological improvement and wide access to telecommunication services even in developing countries. Our review not only traces the transition of standalone activity participation decision models to activity agenda generation and activity sequence generation models but also identifies the progress in incorporating various spatio-temporal interaction effects and the underlying behavioural dynamics of activity participation decisions within these models. One issue identified though is the trade-off between behavioural dynamism and data requirement and the need for standardization of activity categories.
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Lichens are used for human, animal nutrition, healing and for production of colours, perfumes and alcohol. The aim of this study is to evaluate antioxidant, antimicrobial, antibiofilm and cytotoxic potential of Cladonia foliacea a...
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Lichens are used for human, animal nutrition, healing and for production of colours, perfumes and alcohol. The aim of this study is to evaluate antioxidant, antimicrobial, antibiofilm and cytotoxic potential of Cladonia foliacea and Hypogymnia physodes. Chemical profiling of three types of lichen extracts (acetone, ethylacetate and methanol extracts) identified as major constituents usnic acid for Cladonia foliacea and atraric acid, olivetol, atranol, methyl haematommate and chloroatranol for Hypogymnia physodes. The strongest antioxidant capacity was detected for methanol extracts of both species with much higher values for Hypogymnia physodes (21.38 mu g/ml compared to 1690.73 mu g/ml for Cladoniafoliacea). The acetone and ethylacetate extracts of both species exhibited similar significant activity against Gram-positive bacteria, while the methanol extracts were less active. The antibiofilm activity was confirmed for both lichens with more prominent results for Cladonia foliacea. The acetone and ethylacetate extracts of both species showed good cytotoxic activity on HCT-116 human colon cancer cells. Our study revealed strong antioxidant, antimicrobial, antibiofilm and cytotoxic properties of tested lichens. These findings suggest lichens as potential source of natural preservatives, additives, antimicrobial and anticancer drugs.
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A new series of N-substituted 2-pyrazolines 9a-f, 10a-f, 11a-f, 12a-f and 13a-f were obtained from the cyclocondensation reaction of [(7-chloroquinolin-4-yl)amino]chalcones 8a-f with hydrazine hydrate and its derivatives. Fourteen...
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A new series of N-substituted 2-pyrazolines 9a-f, 10a-f, 11a-f, 12a-f and 13a-f were obtained from the cyclocondensation reaction of [(7-chloroquinolin-4-yl)amino]chalcones 8a-f with hydrazine hydrate and its derivatives. Fourteen of the synthesized compounds including the starting chalcones were selected by US National Cancer Institute (NCI) for testing their anticancer activity against 60 different human cancer cell lines, with the most important GI(50) values ranging from 0.28 to 11.7 mu M (0.13-6.05 mu g/mL) and LC50 values ranging from 2.6 to > 100 mu M (1.2 to > 51.7 mu g/mL), for chalcones 8a,d and pyrazolines 10c,d. All compounds were assessed for antibacterial activity against wild type and multidrug resistant gram negative and gram positive bacteria, with MIC values ranging from 31.25 to 500 mu g/mL. Additionally, the novel compounds were tested for antifungal and antiparasitic properties. Although these compounds showed mild activity against Candida albicans, chalcones 8a and 8e showed high activity against Cryptococcus neoformans with MIC50 = 7.8 mu g/mL. For anti-Plasmodium falciparum activity the 2-pyrazoline 11b was the most active with EC50 = 5.54 mu g/mL. Regarding the activity against Trypanosoma cruzi, compound 10a was highly active with EC50 = 0.70 mu g/mL. Chalcone 8a had good activity against Leishmania panamensis amastigotes with EC50 = 0.79 mu g/mL. (C) 2017 Elsevier Masson SAS. All rights reserved.
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A series of pyridine clubbed 1,3,4-oxadiazole derivatives were efficiently synthesized, characterized by standard spectral techniques and evaluated for their in vitro antitubercular activity against Mycobacterium tuberculosis (MTB...
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A series of pyridine clubbed 1,3,4-oxadiazole derivatives were efficiently synthesized, characterized by standard spectral techniques and evaluated for their in vitro antitubercular activity against Mycobacterium tuberculosis (MTB) H37Ra and Mycobacterium bovis BCG in active and dormant state using an established methods. Compounds 5a, 5m, and 5t were identified as the most active compounds against MTB. Molecular docking was performed against MTB enoyl-ACP (CoA) reductase (FabI/ENR/InhA) enzyme to predict the binding modes and affinity. The theoretical predictions from molecular docking could establish a link between the observed biological activity and the binding affinity shedding light into specific bonded and non-bonded interactions influencing the activity. The active compounds were studied for cytotoxicity against three cell lines and were found to be non-cytotoxic. Specificity of these compounds was checked by screening them for their antibacterial activity against four bacterial strains.
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Activity recognition is essential in providing activity assistance for users in smart homes. While significant progress has been made for single-user single-activity recognition, it still remains a challenge to carry out real-time...
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Activity recognition is essential in providing activity assistance for users in smart homes. While significant progress has been made for single-user single-activity recognition, it still remains a challenge to carry out real-time progressive composite activity recognition. This paper introduces a hybrid ontological and temporal approach to composite activity modelling and recognition by extending existing ontology-based knowledge-driven approach. The compelling feature of the approach is that it combines ontological and temporal knowledge representation formalisms to provide powerful representation capabilities for activity modelling. The paper describes in detail ontological activity modelling which establishes relationships between activities and their involved entities, and temporal activity modelling which defines relationships between constituent activities of a composite activity. As an essential part of the model, the paper also presents methods for developing temporal entailment rules to support the interpretation and inference of composite activities. In addition, this paper outlines an integrated architecture for composite activity recognition and elaborated a unified activity recognition algorithm which can support the recognition of simple and composite activities. The approach has been implemented in a feature-rich prototype system upon which testing and evaluation have been conducted. Initial experimental results have shown average recognition accuracy of 100% and 88.26% for simple and composite activities, respectively.
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A definition of biological activity is proposed that is superficially analogous to the equation relating the thermodynamic activity of a solute to its concentration via an activity coefficient. The biological activity of a molecul...
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A definition of biological activity is proposed that is superficially analogous to the equation relating the thermodynamic activity of a solute to its concentration via an activity coefficient. The biological activity of a molecular entity is defined as A=cf, where A is the activity, c the amount-of-substance concentration, and f is a parameter designated as "inherent activity." Units and dimensions are determined by the type of activity, catalytic (katal) or binding (mol(-1) L). The measurand is described by a chemical equation that identifies the entity for which an activity is being monitored. This definition of biological activity has the advantage of separating the chemical characterization of the entity in terms of structure and amount from the assessment of biological activity. Ideally, a homogeneous entity is used for the measurement of f. In instances where impure materials are used or the chemical equation defining the activity is unknown, the evaluated parameter should be designated as f' to denote its empirical nature. Any measurement of f or f' should be qualified with an appropriate estimate of measurement uncertainty.
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