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Inna S Popova - One of the best experts on this subject based on the ideXlab platform.
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Block synthesis of a type 2 and b type 2 tetrasaccharides related to the human abo blood group system
Carbohydrate Research, 2016Co-Authors: Ivan M Ryzhov, Elena Korchagina, Inna S Popova, Tatiana V Tyrtysh, Alexander S Paramonov, Nicolai V BovinAbstract:Herein we report the synthesis of 3-aminopropyl glycosides of A (type 2) and B (type 2) tetrasaccharides via [3 + 1] Block Scheme. Peracetylated trichloroacetimidates of A and B trisaccharides were used as glycosyl donors. The well-known low reactivity of 4-OH group of N-acetyl-d-glucosamine forced us to test four glucosamine derivatives (3-Bz-1,6-anhydro-GlcNAc and 3-trifluoroacetamidopropyl β-glycosides of 3-Ac-6-Bn-GlcNAc, 3-Ac-6-Bn-GlcN3, and 3-Ac-6-Bn-GlcNAc2) to select the best glycosyl acceptor for the synthesis of type 2 tetrasaccharides. The desired tetrasacchrides were not isolated, when 3-trifluoroacetamidopropyl glycosyde of 3-Ac-6-Bn-GlcNAcβ was glycosylated. Glycosylation of 3-Bz-1,6-anhydro-GlcNAc derivative resulted in α-glycoside as a major product. High stereospecificity was achieved only in the synthesis of B (type 2) tetrasaccharide, when 3-trifluoroacetamidopropyl 3-Ac-6-Bn-GlcNAc2β was applied as the glycosyl acceptor (β/α 5:1), whereas glycosylation with trichloroacetimidate of A trisaccharide was not stereospecific (β/α 1.3:1). Glycosylation of 3-trifluoroacetamidopropyl glycoside of 3-Ac-6-Bn-GlcN3β with trichloroacetimidates of A and B trisaccharides provided the same stereochemical yield (β/α 1.5:1).
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Block synthesis of a tetrasaccharides types 1 3 and 4 related to the human abo blood group system
Carbohydrate Research, 2012Co-Authors: Ivan M Ryzhov, Inna S PopovaAbstract:Blood group A tetrasaccharides of different types have the same terminal trisaccharide fragment that allows using a Block Scheme in their synthesis. 3-Aminopropyl glycosides of tetrasaccharides GalNAcα1-3(Fucα1-2)Galβ1-3GlcNAcβ (A type 1), GalNAcα1-3(Fucα1-2)Galβ1-3GalNAcα (A type 3), and GalNAcα1-3(Fucα1-2)Galβ1-3GalNAcβ (A type 4) were synthesised using acetylated Galα1-3(Fucα1-2)Gal trichloroacetimidate as a glycosyl donor at the key stage.
Ivan M Ryzhov - One of the best experts on this subject based on the ideXlab platform.
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Block synthesis of a type 2 and b type 2 tetrasaccharides related to the human abo blood group system
Carbohydrate Research, 2016Co-Authors: Ivan M Ryzhov, Elena Korchagina, Inna S Popova, Tatiana V Tyrtysh, Alexander S Paramonov, Nicolai V BovinAbstract:Herein we report the synthesis of 3-aminopropyl glycosides of A (type 2) and B (type 2) tetrasaccharides via [3 + 1] Block Scheme. Peracetylated trichloroacetimidates of A and B trisaccharides were used as glycosyl donors. The well-known low reactivity of 4-OH group of N-acetyl-d-glucosamine forced us to test four glucosamine derivatives (3-Bz-1,6-anhydro-GlcNAc and 3-trifluoroacetamidopropyl β-glycosides of 3-Ac-6-Bn-GlcNAc, 3-Ac-6-Bn-GlcN3, and 3-Ac-6-Bn-GlcNAc2) to select the best glycosyl acceptor for the synthesis of type 2 tetrasaccharides. The desired tetrasacchrides were not isolated, when 3-trifluoroacetamidopropyl glycosyde of 3-Ac-6-Bn-GlcNAcβ was glycosylated. Glycosylation of 3-Bz-1,6-anhydro-GlcNAc derivative resulted in α-glycoside as a major product. High stereospecificity was achieved only in the synthesis of B (type 2) tetrasaccharide, when 3-trifluoroacetamidopropyl 3-Ac-6-Bn-GlcNAc2β was applied as the glycosyl acceptor (β/α 5:1), whereas glycosylation with trichloroacetimidate of A trisaccharide was not stereospecific (β/α 1.3:1). Glycosylation of 3-trifluoroacetamidopropyl glycoside of 3-Ac-6-Bn-GlcN3β with trichloroacetimidates of A and B trisaccharides provided the same stereochemical yield (β/α 1.5:1).
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Block synthesis of a tetrasaccharides types 1 3 and 4 related to the human abo blood group system
Carbohydrate Research, 2012Co-Authors: Ivan M Ryzhov, Inna S PopovaAbstract:Blood group A tetrasaccharides of different types have the same terminal trisaccharide fragment that allows using a Block Scheme in their synthesis. 3-Aminopropyl glycosides of tetrasaccharides GalNAcα1-3(Fucα1-2)Galβ1-3GlcNAcβ (A type 1), GalNAcα1-3(Fucα1-2)Galβ1-3GalNAcα (A type 3), and GalNAcα1-3(Fucα1-2)Galβ1-3GalNAcβ (A type 4) were synthesised using acetylated Galα1-3(Fucα1-2)Gal trichloroacetimidate as a glycosyl donor at the key stage.
Nicolai V Bovin - One of the best experts on this subject based on the ideXlab platform.
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Block synthesis of a type 2 and b type 2 tetrasaccharides related to the human abo blood group system
Carbohydrate Research, 2016Co-Authors: Ivan M Ryzhov, Elena Korchagina, Inna S Popova, Tatiana V Tyrtysh, Alexander S Paramonov, Nicolai V BovinAbstract:Herein we report the synthesis of 3-aminopropyl glycosides of A (type 2) and B (type 2) tetrasaccharides via [3 + 1] Block Scheme. Peracetylated trichloroacetimidates of A and B trisaccharides were used as glycosyl donors. The well-known low reactivity of 4-OH group of N-acetyl-d-glucosamine forced us to test four glucosamine derivatives (3-Bz-1,6-anhydro-GlcNAc and 3-trifluoroacetamidopropyl β-glycosides of 3-Ac-6-Bn-GlcNAc, 3-Ac-6-Bn-GlcN3, and 3-Ac-6-Bn-GlcNAc2) to select the best glycosyl acceptor for the synthesis of type 2 tetrasaccharides. The desired tetrasacchrides were not isolated, when 3-trifluoroacetamidopropyl glycosyde of 3-Ac-6-Bn-GlcNAcβ was glycosylated. Glycosylation of 3-Bz-1,6-anhydro-GlcNAc derivative resulted in α-glycoside as a major product. High stereospecificity was achieved only in the synthesis of B (type 2) tetrasaccharide, when 3-trifluoroacetamidopropyl 3-Ac-6-Bn-GlcNAc2β was applied as the glycosyl acceptor (β/α 5:1), whereas glycosylation with trichloroacetimidate of A trisaccharide was not stereospecific (β/α 1.3:1). Glycosylation of 3-trifluoroacetamidopropyl glycoside of 3-Ac-6-Bn-GlcN3β with trichloroacetimidates of A and B trisaccharides provided the same stereochemical yield (β/α 1.5:1).
Jacob K Sont - One of the best experts on this subject based on the ideXlab platform.
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internet based self management plus education compared with usual care in asthma a randomized trial
Annals of Internal Medicine, 2009Co-Authors: Victor Van Der Meer, Moira J Bakker, Wilbert B Van Den Hout, Klaus F Rabe, P J Sterk, J Kievit, Willem J J Assendelft, Jacob K SontAbstract:BACKGROUND: The Internet may support patient self-management of chronic conditions, such as asthma. OBJECTIVE: To evaluate the effectiveness of Internet-based asthma self-management. DESIGN: Randomized, controlled trial. SETTING: 37 general practices and 1 academic outpatient department in the Netherlands. PATIENTS: 200 adults with asthma who were treated with inhaled corticosteroids for 3 months or more during the previous year and had access to the Internet. MEASUREMENTS: Asthma-related quality of life at 12 months (minimal clinically significant difference of 0.5 on the 7-point scale), asthma control, symptom-free days, lung function, and exacerbations. INTERVENTION: Participants were randomly assigned by using a computer-generated permuted Block Scheme to Internet-based self-management (n = 101) or usual care (n = 99). The Internet-based self-management program included weekly asthma control monitoring and treatment advice, online and group education, and remote Web communications. RESULTS: Asthma-related quality of life improved by 0.56 and 0.18 points in the Internet and usual care groups, respectively (adjusted between-group difference, 0.38 [95% CI, 0.20 to 0.56]). An improvement of 0.5 point or more occurred in 54% and 27% of Internet and usual care patients, respectively (adjusted relative risk, 2.00 [CI, 1.38 to 3.04]). Asthma control improved more in the Internet group than in the usual care group (adjusted difference, -0.47 [CI, -0.64 to -0.30]). At 12 months, 63% of Internet patients and 52% of usual care patients reported symptom-free days in the previous 2 weeks (adjusted absolute difference, 10.9% [CI, 0.05% to 21.3%]). Prebronchodilator FEV1 changed with 0.24 L and -0.01 L for Internet and usual care patients, respectively (adjusted difference, 0.25 L [CI, 0.03 to 0.46 L]). Exacerbations did not differ between groups. LIMITATION: The study was unblinded and lasted only 12 months. CONCLUSION: Internet-based self-management resulted in improvements in asthma control and lung function but did not reduce exacerbations, and improvement in asthma-related quality of life was slightly less than clinically significant. PRIMARY FUNDING SOURCE: Netherlands Organization for Health Research and Development, ZonMw, and Netherlands Asthma Foundation
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internet based self management plus education compared with usual care in asthma a randomized trial
Annals of Internal Medicine, 2009Co-Authors: Victor Van Der Meer, Moira J Bakker, Klaus F Rabe, P J Sterk, J Kievit, Willem J J Assendelft, Wilbert B Van Den Hout, Jacob K SontAbstract:Background The Internet may support patient self-management of chronic conditions, such as asthma. Objective To evaluate the effectiveness of Internet-based asthma self-management. Design Randomized, controlled trial. Setting 37 general practices and 1 academic outpatient department in the Netherlands. Patients 200 adults with asthma who were treated with inhaled corticosteroids for 3 months or more during the previous year and had access to the Internet. Measurements Asthma-related quality of life at 12 months (minimal clinically significant difference of 0.5 on the 7-point scale), asthma control, symptom-free days, lung function, and exacerbations. Intervention Participants were randomly assigned by using a computer-generated permuted Block Scheme to Internet-based self-management (n = 101) or usual care (n = 99). The Internet-based self-management program included weekly asthma control monitoring and treatment advice, online and group education, and remote Web communications. Results Asthma-related quality of life improved by 0.56 and 0.18 points in the Internet and usual care groups, respectively (adjusted between-group difference, 0.38 [95% CI, 0.20 to 0.56]). An improvement of 0.5 point or more occurred in 54% and 27% of Internet and usual care patients, respectively (adjusted relative risk, 2.00 [CI, 1.38 to 3.04]). Asthma control improved more in the Internet group than in the usual care group (adjusted difference, -0.47 [CI, -0.64 to -0.30]). At 12 months, 63% of Internet patients and 52% of usual care patients reported symptom-free days in the previous 2 weeks (adjusted absolute difference, 10.9% [CI, 0.05% to 21.3%]). Prebronchodilator FEV1 changed with 0.24 L and -0.01 L for Internet and usual care patients, respectively (adjusted difference, 0.25 L [CI, 0.03 to 0.46 L]). Exacerbations did not differ between groups. Limitation The study was unblinded and lasted only 12 months. Conclusion Internet-based self-management resulted in improvements in asthma control and lung function but did not reduce exacerbations, and improvement in asthma-related quality of life was slightly less than clinically significant. Primary funding source Netherlands Organization for Health Research and Development, ZonMw, and Netherlands Asthma Foundation.
P. C. Jha - One of the best experts on this subject based on the ideXlab platform.
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fuzzy multi objective build or buy approach for component selection of fault tolerant software system under consensus recovery Block Scheme with mandatory redundancy in critical modules
Soft Computing, 2014Co-Authors: Shivani Bali, P. C. Jha, Dinesh U Kumar, Hoang PhamAbstract:During the last two decades, there has been a growing interest in component-based software engineering CBSE both in academia and industry. In component-based system development, it is common to identify software modules first. Once they are identified, we need to select appropriate software components for each module. These components can either be bought as commercial off-the-shelf COTS components and probably adapted to work in the software system or can be developed in-house. This is a 'build-or-buy' decision. This paper discusses a framework that helps a developer to decide whether to buy or to build software components while designing a fault-tolerant modular software system. This paper proposes optimisation models for optimal component selection for a fault-tolerant modular software system under the consensus recovery Block Scheme. It is necessary to identify critical modules in the design of a fault-tolerant modular software system and also to develop a system with a built in redundancy for critical modules. Therefore, the first optimisation model is developed for optimal component selection with the dual objective of reliability maximisation and cost minimisation of the overall system under the constraints on the delivery time and criticality of modules. The second optimisation model is an extension of the first optimisation model and discusses the issue of compatibility of components of modules. In practice, it is not possible for management to obtain precise value of reliability, cost, delivery time, etc., therefore both the models are formulated as fuzzy multi-objective optimisation models. A case study of developing a manufacturing system for medium-size enterprise is used to illustrate the proposed methodology.
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fuzzy optimization approach to component selection of fault tolerant software system
Memetic Computing, 2014Co-Authors: P. C. Jha, Shivani Bali, Dinesh U Kumar, Hoang PhamAbstract:In developing software systems, a manager’s goal is to design software using limited resources and meet the user requirements. One of the important user requirements concerns the reliability of the software. The decision to choose the right software modules (components) becomes extremely difficult because of the number of parameters to be considered while making the decision. If suitable components are not available, then the decision process is further complicated with build versus buy decisions. In this paper, we have formulated a fuzzy multi-objective approach to optimal decision “build-or-buy” for component selection for a fault-tolerant modular software system under the consensus recovery Block Scheme. A joint optimization model is formulated where the two objectives are maximization of system reliability and minimization of the system cost with a constraint on delivery time. An example of developing a retail system for small-and-medium-size enterprises is used to illustrate the proposed methodology.
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Optimal Component Selection Problem for Cots Based Software System under Consensus Recovery Block Scheme: A Goal Programming Approach
International Journal of Computer Applications, 2012Co-Authors: Deepak Kumar, P. K. Kapur, P. C. Jha, U. Dinesh KumarAbstract:Cost, reliability and time are the three main quality attributes of a software system. Now days much software are designed on COTS component in order to facilitate timely development with reduced cost and improved reliability. Software deigned to handle critical control systems have very high reliability requirements. Fault tolerance is designed in these systems for some or all of the software modules so that execution can be resumed even after failure with minimal loss of data and time. Designing fault tolerance requires extra resources. Even though reliability requirement are very high the developers can’t spend endless resources on any project. This is a trade off problem between reliability and cost. Many such problems have been discussed in literature considering distinct objectives and constraints and have given good results. An effective approach to discuss this problem is to formulate a multi-objective problem with cost minimization and reliability maximization as the two objectives with an upper bound on cost and lower bound on reliability. In this paper we formulate this bi-criteria problem and discuss the solution methodology. The problem is formulated for consensus recovery Block fault tolerant Scheme. In case a feasible solution for the problem exists, criterion vector approach is used to solve the problem and otherwise if the bounds are contradictory a goal programming approach is used to solve the problem to obtain a compromised solution. Alternative goal solutions are obtained assigning different weights for the objective to facilitate the decision maker with correct decision.
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optimal component selection of cots based software system under consensus recovery Block Scheme incorporating execution time
International Journal of Reliability Quality and Safety Engineering, 2010Co-Authors: P. C. Jha, Shivani Bali, P. K. Kapur, Dinesh U KumarAbstract:Computer based systems have increased dramatically in scope, complexity, pervasiveness. Most industries are highly dependent on computers for their basic day to day functioning. Safe & reliable software operations are an essential requirement for many systems across different industries. The number of functions to be included in a software system is decided during the software development. Any software system must be constructed in such a way that execution can resume even after the occurrence of failure with minimal loss of data and time. Such software systems which can continue execution even in presence of faults are called fault tolerant software. When failure occurs one of the redundant software modules get executed and prevent system failure. The fault tolerant software systems are usually developed by integrating COTS (commercial off-the-shelf) software components. The motivation for using COTS components is that they will reduce overall system development costs and reduce development time. In this paper, reliability models for fault tolerant consensus recovery Blocks are analyzed. In first optimization model, we formulate joint optimization problem in which reliability maximization of software system and execution time minimization for each function of software system are considered under budgetary constraint. In the second model the issue of compatibility among alternatives available for different modules, is discussed. Numerical illustrations are provided to demonstrate the developed models.