452 research outputs found
AROMATIC INTERACTIONS IN PEPTIDES : DESIGNED HELICES AND β-HAIRPINS
Design of complex protein folds requires complete understanding of the stereochemical principles that govern polypeptide chain folding. Extensive studies on design and synthesis of specific secondary structures like β-helices, β -sheets and hairpins have taught us that the unnatural amino acid
aminoisobutyric acid (Aib) can be successfully employed for helix nucleation and tight turns of appropriate stereochemistry are facilitated by the use of DPro-Xxx sequences. Availability of such rigid secondary structure scaffolds therefore permits the design of synthetic peptides that can be used as models for investigation of tertiary interactions, primarily that of aromatic residues.
Chapter 1 summarizes the present knowledge of peptide design using non-protein amino acids. The chapter also details the unique features of aromatic amino acids, especially tryptophan, and their employment as secondary structure stabilizing elements. Chapters 2-7 contain detailed descriptions of the work carried out on design, synthesis, and structural characterization of designed peptides containing aromatic amino acids. In Chapter 2, the use of aromatic pairs in strand segments of peptide hairpins has been discussed with the results clearly indicating that aromatic interactions at the non-hydrogen bonding position of peptide hairpins contribute to structure stability. In Chapter 3, accommodation of the Leu-Trp-Val segment in helical scaffolds the role of Trp residues in crystallization has been discussed. Chapter 4 outlines the influence of a large number of Trp residues on the preferred backbone conformation, with the studies clearly indicating a preference for helical scaffolds in small peptides. The role of Trp residues at turn regions of peptide hairpins has been discussed in Chapter 5, using examples from both synthetic peptides and from natural peptides containing Pro-Trp segments. The studies suggest that the Pro-Trp segments serve as helix nucleators and disrupt formation of peptide hairpins. The results of this study have been further extended to Conus monile peptides, discussed in Chapter 6. The studies also suggest the role of an aromatic-Pro segment on the cis-trans isomerization of the Xxx-Pro tertiary amide unit. Chapter 7 discusses the contribution of a Cys-His vs Tyr-His pair on strand segment stability in diproline nucleated peptide hairpins. Chapter 8 summarizes the key findings of the work. Chapter 9 lists the references cited in the thesis and the Appendix chapter provides details of experimental techniques used in the study.
SIMULATION OF VSC BASED HVDC TRANSMISSION SYSTEM FOR THE INTEGRATION OF WINDFARM INTO GRID
Wind energy has huge potential to become major source of renewable energy for the modern world. For integrating wind farms to the AC grid, HVDC transmission systems have several advantages over AC transmission systems. This paper presents the design and control of voltage source converter based HVDC system for integration of wind farms in to AC grid. The designed VSC-HVDC system performance under steady state conditions and various transient conditions are presented. The PSCAD/EMTDC software package is used for the simulation studies
An Inclusive Report on Robust Malware Detection and Analysis for Cross-Version Binary Code Optimizations
Numerous practices exist for binary code similarity detection (BCSD), such as Control Flow Graph, Semantics Scrutiny, Code Obfuscation, Malware Detection and Analysis, vulnerability search, etc. On the basis of professional knowledge, existing solutions often compare particular syntactic aspects retrieved from binary code. They either have substantial performance overheads or have inaccurate detection. Furthermore, there aren't many tools available for comparing cross-version binaries, which may differ not only in programming with proper syntax but also marginally in semantics. This Binary code similarity detection is existing for past 10 years, but this research area is not yet systematically analysed. The paper presents a comprehensive analysis on existing Cross-version Binary Code Optimization techniques on four characteristics: 1. Structural analysis, 2. Semantic Analysis, 3. Syntactic Analysis, 4. Validation Metrics. It helps the researchers to best select the suitable tool for their necessary implementation on binary code analysis. Furthermore, this paper presents scope of the area along with future directions of the research
Prevalence of depression among people who attempt suicide
Background: This is a study aimed at assessing the prevalence of major depressive disorder among persons who attempted suicide.Methods: The study involved 30 persons above 18years of age of both sexes who has attempted suicide in the recent past. An informed consent was obtained from all of them. The prevalence of depression among those suicide attempters was studied based on major ICD- 10 depression inventory. Also, intent rating based on Beck’s suicide intent scale was done to assess the severity of suicide attempt. Questionnaire was given and the details were collected.Results: The prevalence of depression is estimated to be 20%. Regarding the suicidal intent, 13 cases (43.33%) showed high intent for suicide.Conclusions: Prevalence of depression is common among people who attempt suicide. Early diagnosis and intervention will reduce suicide attempts
Anti-Psoriatic Effect of Zingiber Officinale Roscae Gel on UV-Radiation and 5% w/w Imiquimod Cream Induced Psoriasis in Wistar Rats
Psoriasis is a chronic, non-communicable, painful, disfiguring and disabling disease for which there is no cure and with great negative impact on patients’ quality of life (QoL). It can occur at any age, and is most common in the age group 50–69. The reported prevalence of Psoriasis in countries ranges between 0.09% and 11.4%, making Psoriasis a serious global problem. The Etiology of Psoriasis remains unclear, although there is evidence for genetic predisposition. The role of the immune system in Psoriasis causation is also a major topic of research.
Psoriasis occurs worldwide. It affects men and women of all ages, regardless of ethnic origin, in all countries. Data on the prevalence of psoriasis in countries vary between 0.09% and 11.4%. In most developed countries, prevalence is between 1.5 and 5%. There is also evidence to suggest that the prevalence of psoriasis may be increasing.
The pathophysiology of Psoriasis is not completely understood. It involves multiple factors, including genetic, immunologic, environmental, stress factors contributing to the development of disease. Cytokines are locally acting protein mediators that are involved in almost all the biological processes including cell growth, activation, inflammation, immunity, and differentiation. Activated T cells are the primary modulators in the pathogenesis of Psoriasis. Disordered cellular immunity involving inflammatory cytokines IL-1 (interleukin-1), IL-6, TNF-α (Tumour necrosis factor) and pro-inflammatory transcription factor has been implicated.
CONCLUSION:
It may be Concluded that Ethanolic extract of ZOR gel showed Reduction of the Scoring Index (Severity score) such as Scaling, Lesions, Redness, Erythema and decrease in Interleukin-23 in the skin of UV-Radiation induced Psoriasis model.
Histopathological study of the skin showed Normal architecture with reduction in Hyperkeratosis, Parakeratosis, and Acanthosis.
Increase in Body weight of Imiquimod cream 5%w/w induced Psoriasis model. Histopathological study of the Ear showed Normal architecture with reduction in Epidermal proliferation, Abnormal differentiation, Epidermal accumulation of neutrophils in microabcesses, Neoangiogenesis.
Clobetasol propionate cream 0.05% w/w and Tretinoin gel 0.04%w/w act by inhibiting the synthesis of Inflammatory mediator Interleukin-23. ZOR gel also act by inhibiting the synthesis of Inflammatory mediator Interleukin-23 thus, it may be concluded that ZOR gel has significant Anti-Psoriatic activity.
Anti-psoriatic activity was found significant in Zingiber officinale roscae may be due to the presence of Vitamin A Beta-Carotene. Further studies to isolate the Chemical constituents responsible for the Anti-Psoriatic activity is required
A conception with congenitally complicated connection: a rare case of pregnancy with total anomalous pulmonary venous connection
Total anomalous pulmonary venous connection (TAPVC) is a congenital cyanotic heart disease characterized by abnormal communication of pulmonary veins into the right atrium rather than into the left atrium leading to mixture of oxygenated and deoxygenated blood. Uncorrected TAPVCs do not survive till adulthood and pregnancy in patients with TAPVC is extremely rare. In patients with TAPVC, the heart cannot withstand the hemodynamic changes associated with pregnancy and hence termination of pregnancy in the first trimester is often required. Here we reported an extremely rare case of pregnancy in a patient with uncorrected TAPVC, terminated successfully in our institute without any complication
High Gain Interleaved Boost Converter for Fuel Cell Applications
Fuel cell is one of the promising technologies for distributed generation. For designing high efficiency fuel cell power systems, a suitable DC-DC converter is required. Among the various topologies, interleaved converters using switched capacitor are considered as a better solution for fuel cell systems due to high conversion efficiency. The objective of the paper is to design and implement a high gain interleaved converter using switched capacitors for fuel cell systems. In the proposed interleaved converter, the front end inductors are magnetically cross-coupled to improve the electrical performance and reduce the weight and size. Also, switched capacitors are used to improve the voltage gain of the converter. The proposed converter has been performed. Simulation study of interleaved converter using switched capacitors interfaced with fuel cells has been studied using Matlab/Simulink. A prototype has been developed to verify the simulation results
Aromatic interactions in tryptophan-containing peptides: crystal structures of model tryptophan peptides and phenylalanine analogs
The crystal structures of the peptides, Boc-Leu-Trp-Val-OMe (1), Ac-Leu-Trp-Val-OMe (2a and 2b), Boc-Leu-Phe-Val-OMe (3), Ac-Leu-Phe-Val-OMe (4), and Boc-Ala-Aib-Leu-Trp-Val-OMe (5) have been determined by X-ray diffraction in order to explore the nature of interactions between aromatic rings, specifically the indole side chain of Trp residues. Peptide 1 adopts a type I β-turn conformation stabilized by an intramolecular 4→1 hydrogen bond. Molecules of 1 pack into helical columns stabilized by two intermolecular hydrogen bonds, Leu(1)NH...O(2)Trp(2) and IndoleNH...O(1)Leu(1). The superhelical columns further pack into the tetragonal space group P43 by means of a continuous network of indole-indole interactions. Peptide 2 crystallizes in two polymorphic forms, P21 (2a) and P212121 (2b). In both forms, the peptide backbone is extended, with antiparallel β-sheet association being observed in crystals. Extended strand conformations and antiparallel β-sheet formation are also observed in the Phe-containing analogs, Boc-Leu-Phe-Val-OMe (3) and Ac-Leu-Phe-Val-OMe (4). Peptide 5 forms a short stretch of 310-helix. Analysis of aromatic-aromatic and aromatic-amide interactions in the structures of peptides, 1, 2a, 2b are reported along with the examples of 14 Trp-containing peptides from the Cambridge Crystallographic Database. The results suggest that there is no dramatic preference for a preferred orientation of two proximal indole rings. In Trp-containing peptides specific orientations of the indole ring, with respect to the preceding and succeeding peptide units, appear to be preferred in β-turns and extended structures
High Gain Interleaved Boost Converter for Fuel Cell Applications
Fuel cell is one of the promising technologies for distributed generation. For designing high efficiency fuel cell power systems, a suitable DC-DC converter is required. Among the various topologies, interleaved converters using switched capacitor are considered as a better solution for fuel cell systems due to high conversion efficiency. The objective of the paper is to design and implement a high gain interleaved converter using switched capacitors for fuel cell systems. In the proposed interleaved converter, the front end inductors are magnetically cross-coupled to improve the electrical performance and reduce the weight and size. Also, switched capacitors are used to improve the voltage gain of the converter. The proposed converter has been performed. Simulation study of interleaved converter using switched capacitors interfaced with fuel cells has been studied using Matlab/Simulink. A prototype has been developed to verify the simulation results
An Automated Framework for Detecting Change in the Source Code and Test Case Change Recommendation
Improvements and acceleration in software development have contributed towards high-quality services in all domains and all fields of industry, causing increasing demands for high-quality software developments. The industry is adopting human resources with high skills, advanced methodologies, and technologies to match the high-quality software development demands to accelerate the development life cycle. In the software development life cycle, one of the biggest challenges is the change management between the version of the source codes. Various reasons, such as changing the requirements or adapting available updates or technological upgrades, can cause the source code's version. The change management affects the correctness of the software service's release and the number of test cases. It is often observed that the development life cycle is delayed due to a lack of proper version control and due to repetitive testing iterations. Hence the demand for better version control-driven test case reduction methods cannot be ignored. The parallel research attempts propose several version control mechanisms. Nevertheless, most version controls are criticized for not contributing toward the test case generation of reduction. Henceforth, this work proposes a novel probabilistic rule-based test case reduction method to simplify the software development's testing and version control mechanism. Software developers highly adopt the refactoring process for making efficient changes such as code structure and functionality or applying changes in the requirements. This work demonstrates very high accuracy for change detection and management. This results in higher accuracy for test case reductions. The outcome of this work is to reduce the development time for the software to make the software development industry a better and more efficient world
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