scholarly journals TMAO: Protecting Proteins from Feeling the Heat

2020 ◽  
Author(s):  
Mayank Boob ◽  
Shahar Sukenik ◽  
Martin Gruebele ◽  
Taras Pogorelov
Keyword(s):  
Protein Stability ◽  
Local Environment ◽  
Marine Animals ◽  
Urea Denaturation ◽  
Unfolded State ◽  
Model Protein ◽  
Different Temperatures ◽  
Long Time ◽  
Transient Interactions ◽  
Concentration Threshold

Osmolytes are ubiquitous in the cell and play an important role in controlling protein stability under stress. The natural osmolyte trimethylamine N-oxide (TMAO) is used by marine animals to counteract the effect of pressure denaturation at large depths. The molecular mechanism of TMAO stabilization against pressure and urea denaturation has been extensively studied, but the effect of TMAO against high temperature has not been addressed. To delineate the effect of TMAO on folded and unfolded ensembles at different temperatures, we study a mutant of the well-characterized, fastfolding model protein B (PRB). We have carried out extensive, >190 µs in total, all-atom simulations of thermal folding/unfolding of PRB at multiple temperatures and concentrations of TMAO. The simulations captured folding and unfolding events and show an increased stability of PRB in presence of TMAO. At higher TMAO concentration, intermediate ensembles are gradually more favored over the unfolded state. Quantifying TMAO-water interactions revealed that at a low concentration threshold, TMAO forms a shell near but not at the protein surface, disrupting the water network and increasing hydration of the protein to help stabilize it. Intriguingly, we found that there are intermittent interactions between TMAO and certain protein side chains with preferred TMAO orientations. Although previous studies have proposed such interactions, the long time scales we study here help to highlight the protein’s sensitivity to local environment, particularly hydration, and raise questions about how even transient interactions could couple protein stability to TMAO effects.

scholarly journals TMAO: Protecting Proteins from Feeling the Heat

2020 ◽  
Author(s):  
Mayank Boob ◽  
Shahar Sukenik ◽  
Martin Gruebele ◽  
Taras Pogorelov
Keyword(s):  
Protein Stability ◽  
Local Environment ◽  
Marine Animals ◽  
Urea Denaturation ◽  
Unfolded State ◽  
Model Protein ◽  
Different Temperatures ◽  
Long Time ◽  
Transient Interactions ◽  
Concentration Threshold

Osmolytes are ubiquitous in the cell and play an important role in controlling protein stability under stress. The natural osmolyte trimethylamine N-oxide (TMAO) is used by marine animals to counteract the effect of pressure denaturation at large depths. The molecular mechanism of TMAO stabilization against pressure and urea denaturation has been extensively studied, but the effect of TMAO against high temperature has not been addressed. To delineate the effect of TMAO on folded and unfolded ensembles at different temperatures, we study a mutant of the well-characterized, fastfolding model protein B (PRB). We have carried out extensive, >190 µs in total, all-atom simulations of thermal folding/unfolding of PRB at multiple temperatures and concentrations of TMAO. The simulations captured folding and unfolding events and show an increased stability of PRB in presence of TMAO. At higher TMAO concentration, intermediate ensembles are gradually more favored over the unfolded state. Quantifying TMAO-water interactions revealed that at a low concentration threshold, TMAO forms a shell near but not at the protein surface, disrupting the water network and increasing hydration of the protein to help stabilize it. Intriguingly, we found that there are intermittent interactions between TMAO and certain protein side chains with preferred TMAO orientations. Although previous studies have proposed such interactions, the long time scales we study here help to highlight the protein’s sensitivity to local environment, particularly hydration, and raise questions about how even transient interactions could couple protein stability to TMAO effects.

scholarly journals Impact of Deuteration and Temperature on Furan Ring Dynamics

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2889
Author(s):  
Przemyslaw Dopieralski ◽  
Iryna V. Omelchenko ◽  
Zdzislaw Latajka
Keyword(s):  
Conformational Changes ◽  
Furan Ring ◽  
Computational Studies ◽  
Significant Progress ◽  
Dynamic Simulations ◽  
Cyclic Molecules ◽  
Ring Dynamics ◽  
Different Temperatures ◽  
Long Time ◽  
Shape And Size

Despite significant progress in conformational analysis of cyclic molecules, the number of computational studies is still limited while most of that available in the literature data have been obtained long time ago with outdated methods. In present research, we have studied temperature driven conformational changes of the furan ring at three different temperatures. Additionally, the effect of deuteration on the ring dynamics is discussed; in addition, the aromaticity indices following the Bird and HOMA schemes are computed along all trajectories. Our ab initio molecular dynamic simulations revealed that deuteration has changed the furan ring dynamics and the obvious consequences; in addition, the shape and size of molecule are expected to be different.

scholarly journals Contribution of Supportive Local Communities to Sustainable Event Tourism

2021 ◽  
Vol 13 (14) ◽  
pp. 7853
Author(s):  
Xiubai Li ◽  
Jinok Susanna Kim ◽  
Timothy J. Lee
Keyword(s):  
Local Community ◽  
Local Development ◽  
Local Environment ◽  
Local Resident ◽  
Public Agency ◽  
Cultural Festivals ◽  
Long Time ◽  
Local Residents ◽  
Puppet Show ◽  
Supportive Community

The importance of community attitude and participation for the success and sustainability of cultural festivals has been steadily increasing in recent years. The Chuncheon Puppet Festival (CPF) is an international festival that has been held every year since 1989 in Chuncheon, Korea. The festival has several distinctive characteristics as a sustainable event because: (a) it maintains its single genre of puppet performances based on modern cultural art; (b) it is well-established as the festival for the local residents of Chuncheon City and is planned by local community residents and local small companies, not by government agencies or global large entrepreneurs; (c) it helps children to have an interesting cultural experience in the local environment; and (d) it is regularly hosted in August, an off-season for festivals in Korea that was chosen by residents as it is a school holiday season. However, there is still room for improvement to secure its place as a successful sustainable festival. The following might be considered: (i) increased exchange of human resources among the festival executive members, community groups, and the public staff in Chuncheon City; (ii) local residents should maintain full control of the festival; and (iii) a local cultural trust should be established by cultural art professionals, local resident organizations, puppet show professionals, and public agency staff. The CPF is a typical example of a successful sustainable festival with proactive and supportive community participation and a large number of volunteers that help to increase local competitiveness and sustainable local development. This case report delivers insightful lessons and messages to guide what needs to be preconditioned for local cultural festivals to be sustainable and successful for a long time in many destinations, where they can contribute as efficient catalysts for regional tourism development.

Mechanical and tribological properties of ice-bonded abrasive polishing tools

2017 ◽  
Vol 233 (1) ◽  
pp. 132-144 ◽  
Author(s):  
S Rambabu ◽  
N Ramesh Babu
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Melting Rate ◽  
Wear Behaviour ◽  
Mechanical And Tribological Properties ◽  
Different Temperatures ◽  
Long Time ◽  
Polishing Tool ◽  
Hardness Coefficient

This article covers the efforts on characterising ice-bonded abrasive polishing tool in terms of the mechanical and tribological properties such as hardness, coefficient of friction, and wear rate. These studies were attempted on the tools prepared at different temperatures ranging from −10 °C to 0 °C with a view to identify the condition suitable to prepare ice-bonded abrasive polishing tool for effective polishing of Ti–6Al–4V alloy specimen. It also presents the methods adopted to determine various properties of ice-bonded abrasive polishing tool. Hardness was estimated from the measured penetration depth of cone shape indenter into the tool, coefficient of friction was determined from the change in power drawn by the motor rotating the tool mould, and wear behaviour of tool was assessed from the melting rate of the tool determined from the change in height of ice-bonded abrasive polishing tool at different stages of polishing. From the results of this study, it is clear that ice-bonded abrasive polishing tool prepared at −4 °C has possessed sufficient hardness, coefficient of friction, and reasonable wear rate suitable for polishing of Ti–6Al–4V specimens. This article also covers the details of low-temperature coolant supply unit developed to prepare the ice-bonded abrasive polishing tool at any desired temperature between 0 °C and −40 °C and thus to maintain it for a long time. Polishing studies with such ice-bonded abrasive polishing tool showed 72% improvement in finish after 90 min of polishing of Ti–6Al–4V specimen with tool, prepared at −4 °C.

scholarly journals Exploration and Characterization of Trichoderma sp. in Conventional and Organic Rice field in Bali

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
A. A. S. P. R. Andriani ◽  
Idris Sharif ◽  
Bohari M Yamin ◽  
S. A. M. P. Suryani ◽  
Krisnawan Kalimutu
Keyword(s):  
Trichoderma Harzianum ◽  
Rice Field ◽  
Local Environment ◽  
High Density ◽  
Rice Cultivation ◽  
Trichoderma Spp ◽  
Plastic Container ◽  
Trichoderma Sp ◽  
Long Time

Abstract. Although Trichoderma spp has been widely used in the SRI technique of rice cultivation the sources of Trichoderma that can adapt well to the local environment have been an interesting issue for quite some time.  It is commonly agreed that the local Trichoderma is much more preferred to be used for rice cultivation. In the present study, the Trichoderma from the soil of a rice field in Sukawati District,  Bali where conventional fertilizer and pesticide has been applied for a very long time was isolated.  After macroscopic observations (green color and sweet coconut smell ) the single isolated fungi have very much resembled Trichoderma Harzianum. 2 mL of the Trichoderma Harzianum solution was introduced in a plastic container containing 200 g half-boiled rice. After seven days the rice in the plastic appeared green. This sample will be used to produce more T. Harzianum for rice cultivation. One of the T.Harzianum treated rice hosts was coated with gold and subjected to SEM observation. Very high populated T. Harzianum fungi were observed. It was  dominated by hyphae. No conidia and conidiophores were spotted. Instead, quite a high density of spherical and oval shape spores was observed. Such a high density of T.Harzianum will certainly meet the requirement for an efficient application in the cultivation field. It would also be interesting to see the interaction between such a highly populated T.Harzianum  with other fungi or pathogens in understanding the role of Trichoderma as an antipathogen

scholarly journals DETERMINANTS OF ASSETS GROWTH OF FOREIGN OWNED BANKS IN INDONESIA

2020 ◽  
Vol 13 (2) ◽  
pp. 41-50
Author(s):  
Aswin Rivai ◽  
Rina Indiastuti
Keyword(s):  
Foreign Direct Investment ◽  
Interest Rate ◽  
Direct Investment ◽  
Bilateral Trade ◽  
Operating Experience ◽  
Local Environment ◽  
Least Square ◽  
Policy Makers ◽  
Foreign Countries ◽  
Long Time

The aim of this research is to assess the dominant factors enabling foreign owned banks to increase their assets in Indonesia and to confirm whether the “follow the customers hypothesis” is also applicable in motivating foreign owned banks to do business in Indonesia to support investment and trade activities of the companies originated from foreign countries. Using the panel data of 28 foreign owned commercial banks in Indonesia between 2006-2015 obtained from Indonesian Banking Directory, Indonesian Banking Statistics databases, foreign country central bank websites, a least square dummy variable (LSDV) regression model was applied to examine the effect of Bilateral Trade, Foreign Direct Investment (FDI), Interest Rate Differences, Domestic Deposits, Parent banks Return on Assets (ROA) and Length of Time presence of the foreign owned banks in Indonesia on Assets or Size of Foreign Owned Banks. The main findings is that the decisions by foreign owned banks to operate and to expand its business in Indonesia is predominantly affected by the increase in realization of projects funded by Foreign Direct Investment from counterpart countries, third parties fund or domestic deposit denominated in foreign currencies, profitability of the parent banks in home country and long time presence in Indonesia to enable parent bank and their branches or subsidiaries gain better operating experience, better general managerial expertise and better knowledge of local environment. Bilateral Trade and Interest Rate Differences between home and host country has no impacts at all on Assets of Foreign Owned Banks. “Follow the customer hypothesis” is applicable in Indonesia only in terms of FDIs but not applicable in terms of bilateral trade. The findings will help management of the banks in designing more reliable business plan and also used as input or tools for policy makers prior issuing the license for the newly open foreign owned banks offices or increase of its branch offices. It is suggested foreign owned banks to consider empowering its trade financing scheme which will increase the banks size or assets.

scholarly journals Heat Exchanger for Bio-Digester under Thermophilic Range

2019 ◽  
Vol 5 ◽  
pp. 79-88
Author(s):  
Prajwal Sapkota ◽  
Laxman Poudel
Keyword(s):  
Heat Exchanger ◽  
Anaerobic Digestion ◽  
Heat Exchangers ◽  
Heating System ◽  
Gas Production ◽  
Cow Dung ◽  
Digestion Rate ◽  
Digestion Process ◽  
Different Temperatures ◽  
Long Time

Bio-gas has been one of the sources of renewable energy and has been used from long time. It is produced by the anaerobic digestion or decomposition of organic compounds and has different process. The digestion process is carried out by bacteria present in the waste and it is highly dependent on the bacteria which work differently on different temperatures. The rate of anaerobic digestion is highest at hemophilic temperature (55°C). Similarly, it is moderate at mesophilic temperature (35°C) and is lowest at psychrophilic (below 20°C). Thus, to attain the highest digestion rate a thermophilic heating system has beend eveloped. The heating system uses five heat exchangers to heat the influent at digester which is of 35m3 volume, to maintain temperature at 56°C. The volume of bio-gas production from this system which uses cow dung as digestingmaterial is about 28 m3 per day.

scholarly journals Poloxamer Hydrogels for Biomedical Applications

Pharmaceutics ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 671 ◽  
Author(s):  
Eleonora Russo ◽  
Carla Villa
Keyword(s):  
Drug Delivery ◽  
Ethylene Oxide ◽  
Propylene Oxide ◽  
Biomedical Application ◽  
Aqueous Environment ◽  
Molecular Weights ◽  
Long Time ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Concentration Threshold

This review article focuses on thermoresponsive hydrogels consisting of poloxamers which are of high interest for biomedical application especially in drug delivery for ophthalmic, injectable, transdermal, and vaginal administration. These hydrogels remain fluid at room temperature but become more viscous gel once they are exposed to body temperature. In this way, the gelling system remains at the topical level for a long time and the drug release is controlled and prolonged. Poloxamers are synthetic triblock copolymers of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO), also commercially known as Pluronics®, Synperonics® or Lutrol®. The different poloxamers cover a range of liquids, pastes, and solids, with molecular weights and ethylene oxide–propylene oxide weight ratios varying from 1100 to 14,000 and 1:9 to 8:2, respectively. Concentrated aqueous solutions of poloxamers form thermoreversible gels. In recent years this type of gel has arouse interest for tissue engineering. Finally, the use of poloxamers as biosurfactants is evaluated since they are able to form micelles in an aqueous environment above a concentration threshold known as critical micelle concentration (CMC). This property is exploited for drug delivery and different therapeutic applications.

scholarly journals 14C Dating of Fire-Damaged Mortars from Medieval Finland

Radiocarbon ◽  
2012 ◽  
Vol 54 (3-4) ◽  
pp. 915-931 ◽  
Author(s):  
Alf Lindroos ◽  
Lior Regev ◽  
Markku Oinonen ◽  
Åsa Ringbom ◽  
Jan Heinemeier
Keyword(s):  
14C Dating ◽  
Carbon And Oxygen Isotopes ◽  
Fire Event ◽  
Oxygen Isotope Ratios ◽  
Hydrolysis Process ◽  
Carbon And Oxygen Isotope ◽  
Different Temperatures ◽  
Long Time ◽  
Original Construction ◽  
Soluble Carbonate

This study focuses on radiocarbon dating of mortars that have withstood city fires and display visible fire damage effects. Some fire-damaged and undamaged original Medieval mortars from the same site have also been tested. The mortars were heated at different temperatures and then analyzed using the same preparation procedures as in 14C dating of mortars to see what kind of changes the heating would introduce to the mineralogy, chemistry, and the carbon and oxygen isotope ratios. We found that decarbonation during heating starts at ∼600 ° and recarbonation starts as soon as the temperature drops. Already after a few days, most of the lost CO2 has been replaced with atmospheric CO2. The renewed carbonates are readily soluble in the acid hydrolysis process and their carbon and oxygen isotopes have a light signature. Fire-damaged historical mortars display the same features. If a long time has elapsed between hardening of the original mortar and the fire, the new carbonates have 14C concentrations that point to the fire event rather than to the building event. In several cases, the fire-damaged mortars have an easily soluble carbonate fraction with a 14C age that could be related to a major fire event, but still most of the soluble carbonate yields a 14C age that seems like a reasonable age for the original construction.

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