25 results on '"Lenka DR"'
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2. Biodegradable WE43 Mg alloy/hydroxyapatite interpenetrating phase composites with reduced hydrogen evolution
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Lenka Drotárová, Karel Slámečka, Tomáš Balint, Michaela Remešová, Radovan Hudák, Jozef Živčák, Marek Schnitzer, Ladislav Čelko, and Edgar B. Montufar
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Magnesium ,Biodegradable metal ,Calcium phosphate cement ,Hydroxyapatite ,Composite ,Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Biology (General) ,QH301-705.5 - Abstract
Biodegradable magnesium implants offer a solution for bone repair without the need for implant removal. However, concerns persist regarding peri-implant gas accumulation, which has limited their widespread clinical acceptance. Consequently, there is a need to minimise the mass of magnesium to reduce the total volume of gas generated around the implants. Incorporating porosity is a direct approach to reducing the mass of the implants, but it also decreases the strength and degradation resistance. This study demonstrates that the infiltration of a calcium phosphate cement into an additively manufactured WE43 Mg alloy scaffold with 75 % porosity, followed by hydrothermal treatment, yields biodegradable magnesium/hydroxyapatite interpenetrating phase composites that generate an order of magnitude less hydrogen gas during degradation than WE43 scaffolds. The enhanced degradation resistance results from magnesium passivation, allowing osteoblast proliferation in indirect contact with composites. Additionally, the composites exhibit a compressive strength 1.8 times greater than that of the scaffolds, falling within the upper range of the compressive strength of cancellous bone. These results emphasise the potential of the new biodegradable interpenetrating phase composites for the fabrication of temporary osteosynthesis devices. Optimizing cement hardening and magnesium passivation during hydrothermal processing is crucial for achieving both high compressive strength and low degradation rate.
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- 2024
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3. Editorial: Agents of political socialization in the 21st century
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Anne-Marie Jeannet, Lenka Dražanová, and Alina Vrânceanu
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political socialization ,Europe ,political participation ,agents of socialization ,social change ,intergenerational transmission ,Political science - Published
- 2024
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4. A Clinico-Pathological Study On Mukhadushika And Its Management By Lodhradi LepaAnd Arogyavardhani VatiWith Special Reference To Acne Vulgaris: DOI:https://doi.org/10.47223/IRJAY.2021.4512
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Lenka, Dr. Bishnupriya, Kumar Panda, Prof. (Dr.) Pradip, sahu, Dr. Manoranjan, Lenka, Dr. Bishnupriya, Kumar Panda, Prof. (Dr.) Pradip, and sahu, Dr. Manoranjan
- Abstract
Introduction:-Today’s lifestyle changes like irregular diet, pollution, Stress, hormonal changes are directly affect the skin. It may cause many skin diseases and most common among them is Acne vulgaris which can be correlated with Mukhadushika in Ayurved, which is about 80% of population in the age of of 12-30 years. In Shusruta samhita it is described in Kshudra Rogadhikar.Materials and methods:-A total no. of 30 patients fulfilling the diagnostic criteria of Mukhadushika (Acne vulgaris) were divided into two groups A and B (N=15). Group Ap atient were treated with Lodhradi Lepa (as required) applied externally for 30 days and Group B with Lodhradi lepa (as required) applied externally along with Arogyavardhani Vati 250mg twice daily for 30 days both respectively.Observation and results:-There were 53% and 62.2% of improvement in signs and symptoms in the patients of Group-A and Group-B were observed in this study respectively. The Statistically significant (P<0.05) result was revealed in both Group-A and Group-B but improvement was noticed more in Group-B. Regarding Hormonal (Testosterone and Estrogen) findings, significant(P<0.05) result was noticed in Group B and insignificant result in Group A (P>0.05).Conclusion:-The study revealed that out of 30 cases taken for study, group B showed better result as compared to group A in overall effect. No side effect was noticed during clinical study.
- Published
- 2021
5. A Clinico-Pathological Study On Mukhadushika And Its Management By Lodhradi LepaAnd Arogyavardhani Vati With Special Reference To Acne Vulgaris
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Lenka, Dr. Bishnupriya, primary, Panda, Prof. (Dr.) Pradip Kumar, additional, and Sahu, Dr. Manoranjan, additional
- Published
- 2021
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6. Hydroxyapatite-Resin Composites Produced by Vat Photopolymerization and Post-Processing via In Situ Hydrolysis of Alpha Tricalcium Phosphate
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Carolina Oliver-Urrutia, Lenka Drotárová, Sebastián Gascón-Pérez, Karel Slámečka, Simona Ravaszová, Ladislav Čelko, and Edgar B. Montufar
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vat polymerization ,alpha tricalcium phosphate ,hydroxyapatite ,porous composite ,mechanical strength ,Technology ,Chemical technology ,TP1-1185 - Abstract
Vat photopolymerization is an additive manufacturing technique that utilizes photosensitive resins to fabricate 3D polymeric objects with high precision. However, these objects often lack mechanical strength. This study investigated the strengthening of a resin based on epoxidized soybean oil acrylate, specifically designed for vat photopolymerization, by the in situ formation of hydroxyapatite nanocrystals. First, a stable alpha tricalcium phosphate (α-TCP)-resin feedstock mixture was developed (~30 vol.% α-TCP), which proved suitable for fabricating monoliths as well as complex triply periodic minimal surface (gyroid, diamond, and Schwarz) porous structures through vat photopolymerization. The results demonstrated that the incorporation of α-TCP particles led to a significant mechanical improvement of the resin. Second, post-printing hydrothermal treatments were utilized to transform the α-TCP particles into hydroxyapatite crystals within the resin. It was observed that the space between hydroxyapatite crystals within the composites was occupied by the cured resin, resulting in a more compact, stronger, and mechanically more reliable material than the porous hydroxyapatite produced by the hydrolysis of α-TCP mixed with water. Moreover, water absorption during the hydrothermal treatments caused the plasticization of the cured resin. As a consequence, the hydroxyapatite-resin composites displayed slightly lower mechanical properties compared to the as-printed α-TCP-resin composite.
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- 2023
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7. Are Histidine Kinases of Arbuscular Mycorrhizal Fungi Involved in the Response to Ethylene and Cytokinins?
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Ayla Mongès, Hajar Yaakoub, Baptiste Bidon, Gaëlle Glévarec, François Héricourt, Sabine Carpin, Lucie Chauderon, Lenka Drašarová, Lukáš Spíchal, Brad M. Binder, Nicolas Papon, and Soizic Rochange
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cytokinin ,ethylene ,mycorrhiza ,receptor ,Rhizophagus ,symbiosis ,Microbiology ,QR1-502 ,Botany ,QK1-989 - Abstract
Signals are exchanged at all stages of the arbuscular mycorrhizal (AM) symbiosis between fungi and their host plants. Root-exuded strigolactones are well-known early symbiotic cues, but the role of other phytohormones as interkingdom signals has seldom been investigated. Here we focus on ethylene and cytokinins, for which candidate receptors have been identified in the genome of the AM fungus Rhizophagus irregularis. Ethylene is known from the literature to affect asymbiotic development of AM fungi, and in the present study, we found that three cytokinin forms could stimulate spore germination in R. irregularis. Heterologous complementation of a Saccharomyces cerevisiae mutant strain with the candidate ethylene receptor RiHHK6 suggested that this protein can sense and transduce an ethylene signal. Accordingly, its N-terminal domain expressed in Pichia pastoris displayed saturable binding to radiolabeled ethylene. Thus, RiHHK6 displays the expected characteristics of an ethylene receptor. In contrast, the candidate cytokinin receptor RiHHK7 did not complement the S. cerevisiae mutant strain or Medicago truncatula cytokinin receptor mutants and seemed unable to bind cytokinins, suggesting that another receptor is involved in the perception of these phytohormones. Taken together, our results support the hypothesis that AM fungi respond to a range of phytohormones and that these compounds bear multiple functions in the rhizosphere beyond their known roles as internal plant developmental regulators. Our analysis of two phytohormone receptor candidates also sheds new light on the possible perception mechanisms in AM fungi. [Graphic: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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- 2023
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8. Cohort differences in attitudes toward sexual orientation: the formative political climate as a socializing agent
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Anne-Marie Jeannet and Lenka Dražanová
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attitudes toward sexual orientation ,political socialization ,values ,age cohort analysis ,Europe ,Political science - Abstract
IntroductionWhy do cohorts differ in their attitudes toward sexual orientation and what is the role of societal values during formative years? We investigate whether discontinuities in the prevailing values of equality and tradition in a person's formative years impinge on their attitudes toward sexual orientation as adults.MethodsWe test this by integrating historical political data from the Manifesto Project Dataset with contemporary micro-data on attitudes toward sexual orientation from 10 rounds of the European Social Survey (2002-2020) across 13 cohorts in 13 European countries.Results and discussionUsing hierarchical age-period-cohort analysis with synthetic age cohorts, we find if the value of equality is politically diffuse, it can have a socializing effect. We find that the individuals who came of age during a period when political values of equality were more dominant are more tolerant of gays and lesbians. On the other hand, we do not find any evidence that individuals who experience youth during a time of more traditional political values have more negative opinions about different sexual orientations. Overall, these findings suggest that cohorts adopt distinct patterns of attitudes toward gays and lesbians as a result of a collective process of socialization during their impressionable years.
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- 2023
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9. Attitudes toward immigration in Europe: Cross-regional differences [version 1; peer review: 2 approved]
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Jérôme Gonnot and Lenka Dražanová
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attitudes to immigration ,migration flows ,public opinion ,regions ,eng ,Science ,Social Sciences - Abstract
Background: This article investigates how European public opinion has responded to short-term variations in regional immigration over the past decade (2010-2019). Methods: Combining data from the European Social Survey and the European Union Labour Force Survey and using multilevel modelling, we test how natives’ opinions over migration policy and the contribution of immigrants to society have changed with the net rate of international migrants in 183 EU regions from 21 countries. Results: We find that while European natives living in regions with a higher share of foreign-born populations are generally less anti-immigrant, a short-term increase in the number of immigrants within a given region is associated with more negative attitudes. Conclusion: Our findings demonstrate the importance of temporal dynamics for attitudes to immigration. They also point to the relevance of regional variations in attitudes beside cross-country differences.
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- 2023
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10. Educational expansion and declining religiosity in Italy: a pathway to support for gender egalitarianism among men and women?
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Lenka Dražanová
- Subjects
Sociology (General) ,HM401-1281 - Abstract
Cultural norms connected to the role of women in society have been changing in Italy. This article asks whether educational expansion and declining religiosity act as possible change-inducing factors to foster gender egalitarianism and if so, whether they influence all age groups or only the young in their formative years. I employ a hierarchical age-period-cohort cross-classified random effects model across sixteen cohorts based on micro-level data from the European Values Study’s (1990 - 2020) Italian sample integrated with historical and contemporary contextual measures of educational expansion and secularization. Results show that overall, the changes over time in gender egalitarianism attributable to education and religiosity are mostly driven by period effects, not cohort replacement. I do not find socialization experiences connected to levels of (female) education and religiosity common to particular cohorts to result in distinct gender egalitarian attitudes of these cohorts.
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- 2021
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11. Přehled skladovacích pokusů v ULO atmosféře ve VÝZKUMNÉM A ŠLECHTITELSKÉM ÚSTAVU OVOCNÁŘSKÉM HOLOVOUSY s.r.o. v letech 2005–2020
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Lenka Drbohlavová
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storage ,fruits ,Plant culture ,SB1-1110 ,Botany ,QK1-989 - Abstract
This review article was created by processing data from original scientific research focused on fruit storage experiments under ultra-low oxygen (ULO) conditions. Specifically, these were storage experiments performed in the last fifteen years in the RESEARCH AND BREEDING INSTITUTE OF POMOLOGY HOLOVOUSY Ltd. The research included apple and pear varieties as well as plum or cherry counterparts. Qualitative parameters, sensory traits, content components in the fruit or allergenic substances and extent of pesticide residues were monitored in individual fruits. Not only the choice of variety and the date of fruit harvest had a significant effect on the achieved results. The size of the fruit, the nature of the skin or the weather also contributed.
- Published
- 2021
12. Introducing the Historical Index of Ethnic Fractionalization (HIEF) Dataset: Accounting for Longitudinal Changes in Ethnic Diversity
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Lenka Drazanova
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ethnic fractionalization ,ethnic diversity ,ethnic groups ,intergroup relations ,History of scholarship and learning. The humanities ,AZ20-999 ,Language and Literature - Abstract
Dramatic changes in the ethnic composition of countries in the last decades have sparked new interest among social scientists in studying and uncovering the role of ethnic diversity on social, political and economic outcomes. Yet, most ethnic fractionalization indices used by scholars to study these effects treat ethnic heterogeneity as time-invariant, thus concealing its long-term effects. However, failing to take into account historical developments in ethnic composition might seriously hinder our understanding of their effects on social, economic, and political outcomes. This paper introduces a new dataset containing an annual ethnic fractionalization index for 162 countries across all continents in the period of 1945–2013. The 'Historical Index of Ethnic Fractionalization' (HIEF) dataset is a natural extension of previous ethnic fractionalization indices. It offers the opportunity to study the effects of ethnic fractionalization across countries and over time. The article concludes by offering some preliminary descriptive analysis of patterns of change in ethnic fractionalization over time.
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- 2020
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13. Detection of PCR inhibition in food and feed with a synthetic plasmid
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Tereza Sovová, Barbora Křížová, Lenka Drábková, and Jaroslava Ovesná
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dna isolation ,food analysis ,food quality ,pcr inhibitor ,Agriculture - Abstract
We present a successful use of the plasmid inhibition detection and DNA isolation protocol optimisation for four food/feed samples in qPCR analysis of the sequence coding for chloroplast tRNA-Leu: two meat meal samples and two samples made of cranberries (jam and dried fruit). The quantitative real-time polymerase chain reaction (qPCR) can be inhibited by various substances and the DNA content in the sample can be underestimated. It is necessary to identify the PCR inhibition and choose an optimal DNA isolation protocol to correctly evaluate the sample. In a previous study, we have developed an assay using plasmid DNA carrying a non-homologous random sequence identifying possible inhibitors in qPCR in food/feed samples. The plasmid assay allowed to effectively reveal the PCR inhibition in all of the different sample matrices and to choose an optimal DNA isolation protocol.
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- 2017
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14. Concept caring in nursing
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Lenka Drahošová and Darja Jarošová
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concept caring in nursing ,nature of nursing ,personality of the nurse ,relationship nurse - patient ,literature review ,Nursing ,RT1-120 ,Gynecology and obstetrics ,RG1-991 - Abstract
Aim: The aim of this literature review was to search for qualitative studies focusing on the concept of caring in nursing, to analyse them and to synthesize knowledge that concerns the definition of the concept of caring in nursing from the point of view of nurses and patients. Design: Review. Methods: Qualitative studies were searched for systematically in the electronic databases Academic Search Complete (EBSCO), CINAHL, Medline, Science Direct, and the Wiley Library Online, according to set criteria and defined key words for the period 1970-2015. Seven selected articles were analysed after selection of documents with the aid of a sorting chart. Results: Nurses understand caring in nursing as a relationship with patients which is characterised on the nurses' part by an individual and empathetic approach, attentiveness, experience and sensitivity. Through caring, active communication takes place, providing information which reduces anxiety and leads to the breaking down of barriers. This relationship helps protect patients' autonomy, dignity and comfort. It requires experience on the part of nurses, and it is influenced by the environment. The nurses' personal qualities (what professional knowledge, attitudes and skills they have) and their availability, reliability, and emotional and physical support are important to patients. Conclusion: The concept of caring is a content specific interpersonal process which is characterized by the professional knowledge, skills, personal maturity, and interpersonal sensitivity of nurses, which result in the protection, emotional support, and the meeting of bio-psycho-social needs of patients. The results of the overview study could contribute to an explanation and understanding of the nature of caring as a fundamental feature of the discipline of nursing.
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- 2016
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15. Physiological Responses of Apple and Cherry In Vitro Culture under Different Levels of Drought Stress
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Zuzana Kovalikova, Petra Jiroutova, Jakub Toman, Dominika Dobrovolna, and Lenka Drbohlavova
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drought stress ,in vitro culture ,apple ,cherries ,oxidative stress ,Agriculture - Abstract
Drought stress is a serious threat. Therefore, improvements in crop productivity under conditions of limited water availability are vital to keep global food security. Apples and cherries belong to the most produced fruit worldwide. Thus, searching for their tolerant or resistant cultivars is beneficial for crop breeders to produce more resistant plants. We studied five apple (“Malinové holovouské”, “Fragrance”, “Rubinstep”, “Idared”, “Car Alexander”) and five cherry (“Regina”, “Napoleonova”, “Kaštánka”, “Sunburst”, “P-HL-C”) cultivars for their adaptation in response to progressive drought stress. The reaction of an in vitro culture to osmotic stress simulated by increasing polyethylene glycol (PEG) concentration in medium was evaluated through the morphological (fresh and dry weight, water content, leaf area), physiological (chlorophyll and carotenoids content), and biochemical (reactive oxygen species and malondialdehyde content) parameters. Drought-like stress negatively affected the water content, leaf areas, and chlorophyll content in both fruit species. Oxidative status and membrane damage of plants under water deficiency conditions occurred to be important indicators of stress tolerance mechanism. Cherries exhibited higher hydrogen peroxide levels compared to apples, whereas their malondialdehyde values were generally lower. The overall results indicated wide tolerance range to water deficit among apple and cherry in vitro culture as well as among cultivars within single plant species.
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- 2020
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16. Mechanism of phospho-Ubls' specificity and conformational changes that regulate Parkin activity.
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Lenka DR, Chaurasiya S, Ratnakar L, and Kumar A
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- Humans, Phosphorylation, Ubiquitin metabolism, Ubiquitin chemistry, Models, Molecular, Parkinson Disease metabolism, Parkinson Disease genetics, Mutation, Protein Conformation, Protein Kinases metabolism, Protein Kinases chemistry, Protein Kinases genetics, Binding Sites, Allosteric Regulation, Crystallography, X-Ray, Catalytic Domain, Ubiquitin-Protein Ligases metabolism, Ubiquitin-Protein Ligases chemistry, Ubiquitin-Protein Ligases genetics, Protein Binding
- Abstract
PINK1 and Parkin mutations lead to the early onset of Parkinson's disease. PINK1-mediated phosphorylation of ubiquitin (Ub), ubiquitin-like protein (NEDD8), and ubiquitin-like (Ubl) domain of Parkin activate autoinhibited Parkin E3 ligase. The mechanism of various phospho-Ubls' specificity and conformational changes leading to Parkin activation remain elusive. Herein, we show that compared to Ub, NEDD8 is a more robust binder and activator of Parkin. Structures and biophysical/biochemical data reveal specific recognition and underlying mechanisms of pUb/pNEDD8 and pUbl domain binding to the RING1 and RING0 domains, respectively. Also, pUb/pNEDD8 binding in the RING1 pocket promotes allosteric conformational changes in Parkin's catalytic domain (RING2), leading to Parkin activation. Furthermore, Parkinson's disease mutation K211N in the RING0 domain was believed to perturb Parkin activation due to loss of pUb binding. However, our data reveal allosteric conformational changes due to N211 that lock RING2 with RING0 to inhibit Parkin activity without disrupting pNEDD8/pUb binding., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2024
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17. Additional feedforward mechanism of Parkin activation via binding of phospho-UBL and RING0 in trans .
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Lenka DR, Dahe SV, Antico O, Sahoo P, Prescott AR, Muqit MMK, and Kumar A
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- Humans, Phosphorylation, Crystallography, X-Ray, Models, Molecular, Ubiquitin metabolism, Kinetics, Ubiquitin-Protein Ligases metabolism, Ubiquitin-Protein Ligases genetics, Ubiquitin-Protein Ligases chemistry, Protein Binding
- Abstract
Loss-of-function Parkin mutations lead to early-onset of Parkinson's disease. Parkin is an auto-inhibited ubiquitin E3 ligase activated by dual phosphorylation of its ubiquitin-like (Ubl) domain and ubiquitin by the PINK1 kinase. Herein, we demonstrate a competitive binding of the phospho-Ubl and RING2 domains towards the RING0 domain, which regulates Parkin activity. We show that phosphorylated Parkin can complex with native Parkin, leading to the activation of autoinhibited native Parkin in trans . Furthermore, we show that the activator element (ACT) of Parkin is required to maintain the enzyme kinetics, and the removal of ACT slows the enzyme catalysis. We also demonstrate that ACT can activate Parkin in trans but less efficiently than when present in the cis molecule. Furthermore, the crystal structure reveals a donor ubiquitin binding pocket in the linker connecting REP and RING2, which plays a crucial role in Parkin activity., Competing Interests: DL, SD, OA, PS, AP, AK No competing interests declared, MM MM. is a member of the Scientific Advisory Board of Montara Therapeutics Inc and a scientific consultant to MSD UK, (© 2024, Lenka et al.)
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- 2024
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18. Detailed Insights into the Inhibitory Mechanism of New Ebselen Derivatives against Main Protease (M pro ) of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2).
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Sahoo P, Lenka DR, Batabyal M, Pain PK, Kumar S, Manna D, and Kumar A
- Abstract
SARS-CoV-2 main protease (M
pro /3CLpro ) is a crucial target for therapeutics, which is responsible for viral polyprotein cleavage and plays a vital role in virus replication and survival. Recent studies suggest that 2-phenylbenzisoselenazol-3(2 H )-one (ebselen) is a potent covalent inhibitor of Mpro , which affects its enzymatic activity and virus survival. Herein, we synthesized various ebselen derivatives to understand the mechanism of Mpro inhibition by ebselen. Using ebselen derivatives, we characterized the detailed interaction mechanism with Mpro . We discovered that modification of the parent ebselen inhibitor with an electron-withdrawing group (NO2 ) increases the inhibition efficacy by 2-fold. We also solved the structure of an Mpro complex with an ebselen derivative showing the mechanism of inhibition by blocking the catalytic Cys145 of Mpro . Using a combination of crystal structures and LC-MS data, we showed that Mpro hydrolyzes the new ebselen derivative and leaves behind selenium (Se) bound with Cys145 of the catalytic dyad of Mpro . We also described the binding profile of ebselen-based inhibitors using molecular modeling predictions supported by binding and inhibition assays. Furthermore, we have also solved the crystal structure of catalytically inactive mutant H41N-Mpro , which represents the inactive state of the protein where the substrate binding pocket is blocked. The inhibited structure of H41N-Mpro shows gatekeeper residues in the substrate binding pocket responsible for blocking the substrate binding; mutation of these gatekeeper residues leads to hyperactive Mpro ., Competing Interests: The authors declare no competing financial interest., (© 2022 American Chemical Society.)- Published
- 2022
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19. In vitro efficacy of amitraz, coumaphos, deltamethrin and lindane against engorged female Rhipicephalus (Boophilus) annulatus and Haemaphysalis bispinosa ticks.
- Author
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Ravindran R, Jyothimol G, Amithamol KK, Sunil AR, Chandrasekhar L, Lenka DR, Amritha A, Sreelekha K, Sathish N, Udayan D, Krishna TPA, Divya TM, Juliet S, Kumar KGA, Nair SN, and Ghosh S
- Subjects
- Animals, Coumaphos, Female, Hexachlorocyclohexane, In Vitro Techniques, Nitriles, Pyrethrins, Rhipicephalus, Species Specificity, Toluidines, Acaricides, Ixodidae, Tick Control
- Abstract
The present study compares the in vitro efficacy of four chemical acaricides, viz. amitraz, coumaphos, deltamethrin and lindane, against Rhipicephalus (Boophilus) annulatus and Haemaphysalis bispinosa ticks based on adult immersion tests. Amitraz, at 350 ppm, elicited 29.2 ± 4.17% mortality against R. (B.) annulatus, 100% inhibition of fecundity and absence of hatching of eggs laid by treated ticks. The same compound at 300 ppm caused 62.5 ± 12.5% mortality against H. bispinosa, 96.7% inhibition of fecundity and complete blocking of eclosion. The LC
50 value of amitraz against susceptible H. bispinosa was 181 ppm. Deltamethrin at 400 ppm, elicited 25.0 ± 4.81% adult R. (B.) annulatus mortality, 97.5% inhibition of fecundity and absence of egg hatching. Complete blocking of egg hatching was observed even at 30 ppm. However, deltamethrin (at 50 ppm) elicited 75.0 ± 10.76% mortality against H. bispinosa, 65.8% inhibition of fecundity and very low egg hatching (10%). The LC50 for deltamethrin against susceptible H. bispinosa was 33.8 ppm. Coumaphos at 50 ppm, caused mortality of 70.8 ± 4.17% with R. (B.) annulatus whereas 100% mortality was observed against H. bispinosa. The LC50 values of coumaphos against R. (B.) annulatus and H. bispinosa were 9 and 8.75 ppm, respectively. Complete inhibition (100%) of fecundity was observed even at 30 ppm against both parasites. Complete blocking of egg hatching was also observed even at 10 ppm of coumaphos. Lindane at 1000 ppm caused mortality of 87.5 ± 7.98% against R. (B.) annulatus and 83.3% mortality against H. bispinosa at 100 ppm. The LC50 values of lindane against R. (B.) annulatus and H. bispinosa were 157 and 8.61 ppm, respectively. Complete inhibition of fecundity was observed with R. (B.) annulatus treated with lindane above 200 ppm and with H. bispinosa at a concentration above 50 ppm. Complete blocking of egg hatching was observed in R. (B.) annulatus, even at 100 ppm. Lindane caused 100% blocking of egg hatching at 1 ppm in the case of H. bispinosa.- Published
- 2018
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20. Dirofilaria repens in scrotum of dogs.
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Ravindran R, Julie B, Swapna SA, Jerin F, Jyothimol G, Lenka DR, Nandakumar S, and Sabu SM
- Abstract
Out of 150 apparently healthy male dogs from Kerala, India examined, five revealed single worm in the scrotum. They were found protruding out from beneath the tunica vaginalis when it was incised during the castration operation. Genomic DNA isolated from these worms amplified D. repens specific 246 bp PCR products (KP050552, KP050553). Thickened and enlarged epididymis along with interductal fibrosis, congestion of veins and widening of the cavernous spaces of testes and epididymis were observed in the worm infected dogs. Semeniferous tubules were intact and showed various developmental stages of sperms. The infection resulted in less impact on spermatogenesis.The present communication forms the first report from India on the presence of D. repens in the peritoneal location, which is frequently observed in the subcutaneous locations.
- Published
- 2016
21. Deltamethrin resistance in south Indian isolates of Rhipicephalus (Boophilus) microplus.
- Author
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Lenka DR, Ravindran R, Jyothimol G, Udaykumar M, Reddy PMT, Sathish N, Palla I, Chandramohan B, Ajithkumar KG, Nair SN, Chandrasekhar L, Priya MN, Deepa CK, Sabu L, Juliet S, and Ghosh S
- Abstract
The present communication deals with the detection and characterization of deltamethrin resistance in tick populations using biological (larval packet test), biochemical (esterase enzyme assay) and molecular assays. Ticks were collected from cattle farms of Korutla, Telangana (KOR), Mehboob Nagar, Telangana (MBN), Nagpur, Maharashtra (NAG), Parbani, Maharashtra (PBN), Madhavaram, Tamil Nadu (MAD), Cuddalore, Tamil Nadu (CUD), Sakhleshpur, Karnataka (SAK) and Buvenduvella, Karnataka (BUV). Out of eight field isolates, seven were identified as Rhipicephalus (Boophilus) microplus while one isolate (CUD) was identified as R. (B.) annulatus. The LC
50 values and resistance factors (RF) of field isolates were assessed by larval packet test (LPT). RF values of two isolates viz., Korutla and Parbhani (KOR, PAR) were close to that of reference susceptible isolate. R. (B.) microplus isolate from Nagpur (NAG) and Sakleshpur (SAK) revealed slightly higher RF values (6.42 and 4.51). They revealed slightly elevated esterase enzyme activity too. Other isolates did not reveal higher values for RF or esterase activity. Previously identified mutations conferring synthetic pyrethroid resistance in R. (B.) microplus populations were analysed by sequencing the mutation flanking regions of the carboxyl esterase and the sodium channel genes (domain III S6 and domain II S4-5 linker region). However, these point mutations were not detected in the field isolates. The results of the present study revealed that low levels of synthetic pyrethroid resistance had developed in field populations of ticks of southern India., (Copyright © 2016 Elsevier B.V. All rights reserved.)- Published
- 2016
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22. Occurrence of Gnathostoma spinigerum in a leopard cat from Wayanad Wildlife Sanctuary, Kerala.
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Lenka DR, Johns J, Gopi J, Chandy G, Narayanan PM, Kalarikkal DC, and Ravindran R
- Abstract
The post-mortem examination of a leopard cat from Wayanad Wildlife Sanctuary, Kerala, died in a road accident, revealed presence of gastric tumours containing worms which were identified as Gnathostoma spinigerum based on morphological characteristics.
- Published
- 2016
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23. Histoarchitecture of ovary of Haemaphysalis bispinosa during engorgement period.
- Author
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Sreelekha KP, Chandrasekhar L, Jyothimol G, Lenka DR, Aswathi V, Adarshkrishna TP, Ajithkumar KG, Nair SN, Ravindran R, Juliet S, and Ghosh S
- Subjects
- Animals, Epithelial Cells cytology, Female, Oocytes cytology, Ovary anatomy & histology, Ovary cytology, Ixodidae anatomy & histology, Ixodidae growth & development
- Abstract
The ovary of Haemaphysalis bispinosa was of panoistic type with asynchronous development of oocytes. The wall of the ovary was composed of a layer of epithelial cells to which the oocytes were attached by means of pedicel cells with elongated nucleus. The oocytes were classified into stages I to V based on morphologic characteristics like size and shape, presence / absence of germ vesicle, cytoplasmic appearance, presence or absence of yolk granules and presence of chorion. Day wise changes were in the form of occurrence of oogonia from partially fed upto day zero of engorgement, presence of all stages of oocytes on day one and two after engorgement and onset of degenerative changes in oocytes from day three onwards. Degeneration was complete on day eight with the appearance of polymorphism, vacuolation, cytoplasmic blebbing and autophagic activity in oocytes.
- Published
- 2015
24. Histoarchitecture of the ovary of Rhipicephalus (Boophilus) annulatus during pre- and postengorgement period.
- Author
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Kanapadinchareveetil S, Chandrasekhar L, Gopi J, Lenka DR, Vasu A, KGopalan AK, Nair SN, Ravindran R, Juliet S, and Ghosh S
- Subjects
- Animals, Eating physiology, Female, Oocytes physiology, Ovary anatomy & histology, Ovary physiology, Rhipicephalus physiology, Rhipicephalus anatomy & histology
- Abstract
The present communication describes the detailed day wise study of histological changes of the ovary of Rhipicephalus (Boophilus) annulatus in the postengorgement period together with the systematic classification of their oocytes. The ovary of R. (B.) annulatus is panoistic type with an asynchronous development of oocytes. All the stages (II, III, IV, and V) of oocytes except stage I were similar to R. (B.) microplus. The stage I oocytes showed basophilia, which was not reported earlier in other species of ticks. Day wise changes were in the form of presence of oogonia in partially fed and day one engorged adults, considerable degeneration of oocytes on day two, emergence of new wave of oocytes on day three, presence of mature oocytes up to day eight, and complete degeneration of ovarian tissue from day eight onwards. The degenerative changes in the ovary appeared initially in the oocytes followed by germinal epithelium.
- Published
- 2015
- Full Text
- View/download PDF
25. Low level deltamethrin resistance in ticks from cattle of Kerala, a south Indian state.
- Author
-
Jyothimol G, Ravindran R, Juliet S, Ajithkumar KG, Suresh NN, Vimalkumar MB, Lenka DR, Varghese S, and Ghosh S
- Subjects
- Animals, Arthropod Proteins genetics, Cattle, Esterases genetics, Female, India, Male, Point Mutation, Sodium Channels genetics, Tick Infestations parasitology, Cattle Diseases parasitology, Drug Resistance genetics, Nitriles pharmacology, Pyrethrins pharmacology, Rhipicephalus genetics, Tick Infestations veterinary
- Abstract
The deltamethrin resistance status in Rhipicephalus (Boophilus) annulatus and R. (B.) microplus ticks collected from cattle of five organized farms of Kerala, south India was evaluated. Resistance was characterized using biological (larval packet test), biochemical (esterase enzyme activity assay) and molecular tools (PCR amplification and sequencing of deltamethrin resistance-associated genes). Characterization of field isolates revealed level I resistance in ticks collected from four out of five farms. Elevated level of α/β esterase activity was not recorded in isolates showing level I resistance. Previously reported point mutations in the carboxyl esterase (G1120A) and sodium channel (T2134A and C190A) genes were not observed in any of the field isolates. The present study showed a low level (level I) resistance is developed in the most economically important ticks infesting cattle of this state and it cautions the development of large scale resistance in future., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
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