Dynamics and Pretransitional Effects in C60 Fullerene Nanoparticles and Liquid Crystalline Dodecylcyanobiphenyl (12CB) Hybrid System

The report shows the strong impact of fullerene C60 nanoparticles on phase transitions and complex dynamics of rod-like liquid crystal dodecylcyanobiphenyl (12CB), within the limit of small concentrations. Studies were carried out using broadband dielectric spectroscopy (BDS) via the analysis of temperature dependences of the dielectric constant, the maximum of the primary loss curve, and relaxation times. They revealed a strong impact of nanoparticles, leading to a ~20% change of dielectric constant even at x = 0.05% of C60 fullerene. The application of the derivative-based and distortion-sensitive analysis showed that pretransitional effects dominate in the isotropic liquid phase up to 65 K above the clearing temperature and in the whole Smectic A mesophase. The impact of nanoparticles on the pretransitional anomaly appearance is notable for the smectic–solid phase transition. The fragility-based analysis of relaxation times revealed the universal pattern of its temperature changes, associated with scaling via the “mixed” (“activated” and “critical”) relation. Phase behavior and dynamics of tested systems are discussed within the extended Landau–de Gennes–Ginzburg mesoscopic approach.

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‘Quasi-Tricritical’ and Glassy Dielectric Properties of a Nematic Liquid Crystalline Material

Crystals ◽

10.3390/cryst10040297 ◽

2020 ◽

Vol 10 (4) ◽

pp. 297 ◽

Cited By ~ 1

Author(s):

Aleksandra Drozd-Rzoska

Keyword(s):

Relaxation Time ◽

Nematic Phase ◽

Liquid Crystalline ◽

Strong Electric Field ◽

Low Frequency ◽

Ionic Species ◽

Crystalline Material ◽

Isotropic Liquid ◽

The Impact ◽

Liquid Crystalline Material

Results of dielectric studies in the nematic and isotropic liquid phases of pentylcyanobiphenyl (5CB), a model rod-like liquid crystalline material, are shown. They are based on the discussion of the evolution of dielectric constant ( ε ), its changes under the strong electric field (nonlinear dielectric effect, NDE), and finally, the primary relaxation time. It is shown that changes in ε T and NDE are entirely dominated by the impact of pretransitional fluctuations (pre-nematic and pre-isotropic, respectively) which are associated with the weakly discontinuous character of the isotropic–nematic phase transition. This influence also extends for the low-frequency, ionic species dominated, region. Notable, that the derivative-based and distortions sensitive analysis revealed the tricritical nature of the I-N transition. Although the glass transition in 5CB occurs in the deeply supercooled state at T g ≈ − 68 ° C , the dynamics (changes of the primary relaxation time) follow a previtreous pattern both in the isotropic and in the nematic phase. Finally, the discussion of the ’molecular’ vs. ‘quasi-critical’ characterizations of the isotropic and nematic phases is presented. It shows the evident prevalence of the ‘quasi-critical-picture’, which offers the consistent temperature parameterization in the total tested temperature range.

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DIELECTRIC RELAXATION OF SOME NEARLY SPHERICAL MOLECULES IN THE LIQUID AND SOLID PHASES

Canadian Journal of Physics ◽

10.1139/p67-320 ◽

1967 ◽

Vol 45 (12) ◽

pp. 3815-3822 ◽

Cited By ~ 13

Author(s):

Abhai Mansingh ◽

David B. McLay

Keyword(s):

Dielectric Constant ◽

Melting Point ◽

Dielectric Relaxation ◽

Solid Phase ◽

Relaxation Times ◽

Microwave Frequency ◽

Debye Model ◽

Index Of Refraction ◽

Dielectric Relaxation Time ◽

Rotator Phase

The dielectric constant and loss at a microwave frequency of 9 GHz and also the static dielectric constant at either 10 kHz or 200 kHz have been measured for the nearly spherical molecules Br3CNO2, Cl3CNO2, BrC(CH3)3, ClC(CH3)3, and ClSi(CH3)3 over a range of temperature from below the respective melting point to above this melting point. The measurements combined with the tabulated values for the optical index of refraction allow a determination of the dielectric relaxation times at each temperature if it is assumed that either the Debye theory or the modification of this theory by Cole and Cole is valid. In the cases of the five liquids, the data are consistent with the Debye model. In the solid phase, however, only Cl3CNO2 and ClSi(CH3)3 do not exhibit solid rotator phases, while each of the other three molecules exhibits at least one solid rotator phase. The results are consistent with the interpretation that each liquid has a single dielectric relaxation time but that the transition to a solid rotator phase involves a distribution of relaxation times which are only slightly different in value from the appropriate single value in the liquid phase.

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When Do Psychopathic Traits Affect Cooperative Behavior?: An Iterated Prisoner's Dilemma Experimental Study

10.26686/wgtn.12431003 ◽

2020 ◽

Author(s):

M Testori ◽

M Kempf ◽

RB Hoyle ◽

Hedwig Eisenbarth

Keyword(s):

Prisoner's Dilemma ◽

Cooperative Behavior ◽

Prisoner’S Dilemma ◽

Selection Procedure ◽

Psychopathic Traits ◽

Strong Impact ◽

Iterated Prisoner's Dilemma ◽

Human Decision ◽

The Impact ◽

Iterated Prisoner’S Dilemma

© 2019 Hogrefe Publishing. Personality traits have been long recognized to have a strong impact on human decision-making. In this study, a sample of 314 participants took part in an online game to investigate the impact of psychopathic traits on cooperative behavior in an iterated Prisoner's dilemma game. We found that disinhibition decreased the maintenance of cooperation in successive plays, but had no effect on moving toward cooperation after a previous defection or on the overall level of cooperation over rounds. Furthermore, our results underline the crucial importance of a good model selection procedure, showing how a poor choice of statistical model can provide misleading results.

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Development of Strategies for Glycopeptide Synthesis: An Overview on the Glycosidic Linkage

Current Organic Chemistry ◽

10.2174/1385272824999200701121037 ◽

2020 ◽

Vol 24 (21) ◽

pp. 2475-2497

Author(s):

Andrea Verónica Rodríguez-Mayor ◽

German Jesid Peralta-Camacho ◽

Karen Johanna Cárdenas-Martínez ◽

Javier Eduardo García-Castañeda

Keyword(s):

Chemical Synthesis ◽

Solid Phase ◽

Building Blocks ◽

Heterogeneous Environments ◽

Phase Synthesis ◽

Low Concentrations ◽

Biological Sources ◽

Synthetic Routes ◽

The Impact ◽

Potential Use

Glycoproteins and glycopeptides are an interesting focus of research, because of their potential use as therapeutic agents, since they are related to carbohydrate-carbohydrate, carbohydrate-protein, and carbohydrate-lipid interactions, which are commonly involved in biological processes. It has been established that natural glycoconjugates could be an important source of templates for the design and development of molecules with therapeutic applications. However, isolating large quantities of glycoconjugates from biological sources with the required purity is extremely complex, because these molecules are found in heterogeneous environments and in very low concentrations. As an alternative to solving this problem, the chemical synthesis of glycoconjugates has been developed. In this context, several methods for the synthesis of glycopeptides in solution and/or solid-phase have been reported. In most of these methods, glycosylated amino acid derivatives are used as building blocks for both solution and solid-phase synthesis. The synthetic viability of glycoconjugates is a critical parameter for allowing their use as drugs to mitigate the impact of microbial resistance and/or cancer. However, the chemical synthesis of glycoconjugates is a challenge, because these molecules possess multiple reaction sites and have a very specific stereochemistry. Therefore, it is necessary to design and implement synthetic routes, which may involve various protection schemes but can be stereoselective, environmentally friendly, and high-yielding. This review focuses on glycopeptide synthesis by recapitulating the progress made over the last 15 years.

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The Impact of Economic Crisis on Tourism Industry: A Bangladesh Perspective

International Research Journal of Engineering IT & Scientific Research ◽

10.21744/irjeis.v2i1.35 ◽

2016 ◽

Vol 2 (1) ◽

Author(s):

Md. Ziaul Haque

Keyword(s):

Economic Crisis ◽

Tourism Industry ◽

Political Crisis ◽

Strong Impact ◽

Negative Consequences ◽

Policy Makers ◽

Tourism Product ◽

International Tourist ◽

Sustained Recovery ◽

The Impact

The tourism sector is experiencing numerous challenges as a result of the global economic crisis. After a significant contraction in 2009, tourism rebounded strongly in 2010 and in 2011 the international tourist arrivals and receipts are projected to increase substantially. The Tourism industry is expected to show a sustained recovery in 2012. The crisis has particularly strong impact and slightly negative consequences in Bangladesh. The country is undergoing a political crisis, as well, and it seems that the forthcoming elections may be the only solution for the restoration of stability and social peace. In addition, tourism can be the driving force behind Bangladesh economic recovery. However, for its achievement the country’s policy makers should take several measures towards restructuring and improving the sector. These measures include: enhancement of alternative forms of tourism; environmental protection; creation of quality infrastructure; and boost of competitiveness through a tourism product that offers value for money

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The Impact Of Economic Crisis On Tourism Industry: A Bangladesh Perspective

International Research Journal of Engineering IT & Scientific Research ◽

10.21744/irjeis.v1i1.29 ◽

2015 ◽

Vol 1 (1) ◽

pp. 15

Author(s):

Md. Ziaul Haque

Keyword(s):

Economic Crisis ◽

Tourism Industry ◽

Political Crisis ◽

Strong Impact ◽

Negative Consequences ◽

Policy Makers ◽

Tourism Product ◽

International Tourist ◽

Sustained Recovery ◽

The Impact

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Introduction to geomicrobiology

10.1093/oso/9780198789406.003.0013 ◽

2018 ◽

Author(s):

David L. Kirchman

Keyword(s):

Fossil Fuels ◽

Solid Phase ◽

Direct Reduction ◽

Iron Oxidation ◽

Mineral Dissolution ◽

Precipitation Process ◽

Soluble Ions ◽

Chemolithoautotrophic Bacteria ◽

The Impact

Geomicrobiology, the marriage of geology and microbiology, is about the impact of microbes on Earth materials in terrestrial systems and sediments. Many geomicrobiological processes occur over long timescales. Even the slow growth and low activity of microbes, however, have big effects when added up over millennia. After reviewing the basics of bacteria–surface interactions, the chapter moves on to discussing biomineralization, which is the microbially mediated formation of solid minerals from soluble ions. The role of microbes can vary from merely providing passive surfaces for mineral formation, to active control of the entire precipitation process. The formation of carbonate-containing minerals by coccolithophorids and other marine organisms is especially important because of the role of these minerals in the carbon cycle. Iron minerals can be formed by chemolithoautotrophic bacteria, which gain a small amount of energy from iron oxidation. Similarly, manganese-rich minerals are formed during manganese oxidation, although how this reaction benefits microbes is unclear. These minerals and others give geologists and geomicrobiologists clues about early life on Earth. In addition to forming minerals, microbes help to dissolve them, a process called weathering. Microbes contribute to weathering and mineral dissolution through several mechanisms: production of protons (acidity) or hydroxides that dissolve minerals; production of ligands that chelate metals in minerals thereby breaking up the solid phase; and direct reduction of mineral-bound metals to more soluble forms. The chapter ends with some comments about the role of microbes in degrading oil and other fossil fuels.

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A solid-phase extraction method that eliminates matrix effects of complex pulp mill effluents for the analysis of lipophilic wood extractives

Nordic Pulp & Paper Research Journal ◽

10.1515/npprj-2020-0039 ◽

2020 ◽

Vol 35 (4) ◽

pp. 577-588

Author(s):

Sebastian España Orozco ◽

Philipp Zeitlinger ◽

Karin Fackler ◽

Robert H. Bischof ◽

Antje Potthast

Keyword(s):

Solid Phase Extraction ◽

Matrix Effects ◽

Solid Phase ◽

Internal Standard ◽

Pulp Mill ◽

Phase Extraction ◽

Wood Extractives ◽

Wood Extractive ◽

Pulp Mill Effluents ◽

The Impact

AbstractThe extraction of lipophilic wood extractives from pulp and paper process waters proves to be a challenging task, due to harsh and alternating process and sample conditions. This study has determined the potential use of polymeric sorbents for solid-phase extraction (SPE) and compared to classical silica-based reversed-phase packed columns, with polymeric hydrophilic-lipophilic balanced (HLB) cartridges being the sorbent with the most potential. Recovery functions were obtained with an internal standard mixture representative for the main lipophilic wood extractive groups, which are fatty acids and alcohols, sterols, sterol esters and triglycerides. The impact of pH, sample volume and sample matrix, expressed as TOC and cations, on the retention behavior of lipophilic extractives during SPE of industrial samples were determined with polymeric HLB sorbent. High variations in the composition of pulp mill matrices led to different optimal extraction conditions. Thus, a new SPE protocol was developed, which bypasses matrix interferences and omits the loss of analytes due to sample preparation. The method is applicable to different pulp mill effluents with large discrepancies in pH and sample matrices, resulting in recoveries >90 % with RSD <5 % for all lipophilic wood extractives.

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Solid-Phase Extraction Embedded Dialysis (SPEED), an Innovative Procedure for the Investigation of Microbial Specialized Metabolites

Marine Drugs ◽

10.3390/md19070371 ◽

2021 ◽

Vol 19 (7) ◽

pp. 371

Author(s):

Phuong-Y Mai ◽

Géraldine Le Goff ◽

Erwan Poupon ◽

Philippe Lopes ◽

Xavier Moppert ◽

...

Keyword(s):

Solid Phase Extraction ◽

Solid Phase ◽

Chemical Space ◽

Molecular Profile ◽

Phase Extraction ◽

Specialized Metabolites ◽

Streptomyces Albidoflavus ◽

Cultivation Process ◽

The Impact

Solid-phase extraction embedded dialysis (SPEED technology) is an innovative procedure developed to physically separate in-situ, during the cultivation, the mycelium of filament forming microorganisms, such as actinomycetes and fungi, and the XAD-16 resin used to trap the secreted specialized metabolites. SPEED consists of an external nylon cloth and an internal dialysis tube containing the XAD resin. The dialysis barrier selects the molecular weight of the trapped compounds, and prevents the aggregation of biomass or macromolecules on the XAD beads. The external nylon promotes the formation of a microbial biofilm, making SPEED a biofilm supported cultivation process. SPEED technology was applied to the marine Streptomyces albidoflavus 19-S21, isolated from a core of a submerged Kopara sampled at 20 m from the border of a saltwater pond. The chemical space of this strain was investigated effectively using a dereplication strategy based on molecular networking and in-depth chemical analysis. The results highlight the impact of culture support on the molecular profile of Streptomyces albidoflavus 19-S21 secondary metabolites.

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Cost of Dementia and Its Correlation With Dependence

Journal of Aging and Health ◽

10.1177/0898264315624899 ◽

2016 ◽

Vol 28 (8) ◽

pp. 1448-1464 ◽

Cited By ~ 17

Author(s):

Örjan Åkerborg ◽

Andrea Lang ◽

Anders Wimo ◽

Anders Sköldunger ◽

Laura Fratiglioni ◽

...

Keyword(s):

Cognitive Ability ◽

Resource Utilization ◽

Annual Cost ◽

Neuropsychiatric Symptoms ◽

Dementia Care ◽

Cost Of Care ◽

Path Model ◽

National Study ◽

Strong Impact ◽

The Impact

Objective: To estimate the cost of dementia care and its relation to dependence. Method: Disease severity and health care resource utilization was retrieved from the Swedish National Study on Aging and Care. Informal care was assessed with the Resource Utilization in Dementia instrument. A path model investigates the relationship between annual cost of care and dependence, cognitive ability, functioning, neuropsychiatric symptoms, and comorbidities. Results: Average annual cost among patients diagnosed with dementia was €43,259, primarily incurred by accommodation. Resource use, that is, institutional care, community care, and accommodation, and corresponding costs increased significantly by increasing dependency. Path analysis showed that cognitive ability, functioning, and neuropsychiatric symptoms were significantly correlated with dependence, which in turn had a strong impact on annual cost. Discussion: This study confirms that cost of dementia care increases with dependence and that the impact of other disease indicators is mainly mediated by dependence.

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