bluuebunny/crossref_metadata_2025 huggingface dataset:
Cognitive Reframing of Intimate Partner Aggression: Social and Contextual Influences
Authors: Goodfriend Wind , Arriaga Ximena B.
Published: November 2018

Intimate partner aggression violates U.S. culturally-accepted standards regarding how partners should treat each other. Victims must reconcile the dissonance associated with being in what should be a loving and supportive relationship, while being in the same relationship that is personally and deeply harmful. To manage these clashing cognitions, victims consciously and unconsciously adopt perceptions to reframe their partner’s aggression, minimizing and reinterpreting the occurrence or impact of aggressive acts, and justifying remaining in their relationship. The paper examines the multiple and nested influences that shape such perceptions, including individual, partner, relationship, and cultural factors. Each type of influence is discussed by reviewing previous research and including accounts from women who had experienced aggression. Greater awareness of such perceptions may afford greater control in changing harmful relationship patterns.
The Scope of Earth-Observation to Improve the Consistency of the SDG Slum Indicator
Authors: Kuffer Monika , Wang Jiong , Nagenborg Michael , Pfeffer Karin , Kohli Divyani , Sliuzas Richard , Persello Claudio
Published: November 2018

The continuous increase in deprived living conditions in many cities of the Global South contradicts efforts to make cities inclusive, safe, resilient, and sustainable places. Using examples of Asian, African, and Latin American cities, this study shows the scope and limits of earth observation (EO)-based mapping of deprived living conditions in support of providing consistent global information for the SDG indicator 11.1.1 “proportion of urban population living in slums, informal settlements or inadequate housing”. At the technical level, we compare several EO-based methods and imagery for mapping deprived living conditions, discussing their ability to map such areas including differences in terms of accuracy and performance at the city scale. At the operational level, we compare available municipal maps showing identified deprived areas with the spatial extent of morphological mapped areas of deprived living conditions (using EO) at the city scale, discussing the reasons for inconsistencies between municipal and EO-based maps. We provide an outlook on how EO-based mapping of deprived living conditions could contribute to a global spatial information base to support targeting of deprived living conditions in support of the SDG Goal 11.1.1 indicator, when uncertainties and ethical considerations on data provision are well addressed.
Self-Efficacy of People with Chronic Conditions: A Qualitative Directed Content Analysis
Authors: Ebrahimi Belil Fatemeh , Alhani Fatemeh , Ebadi Abbas , Kazemnejad Anooshirvan
Published: November 2018

Background: Given the increasing prevalence of chronic illnesses and their complications, supporting and empowering chronically ill patients seems crucial. Self-efficacy is considered as a predictor for empowerment. The purpose of this study to explore of different aspects of self-efficacy among persons with chronic physical conditions based on the Family-Centered Empowerment Model (FCEM). Methods: this qualitative study is part of a larger study; sequential exploratory mixed-method for designing an instrument for the FCEM was conducted from May 2015 to March 2016 in two university hospitals. The sample was 22 participants, including chronically ill patients, family caregivers, and nurses. Data were collected through personal semi-structured interviews. Data analysis was performed concurrently with data collection through directed qualitative content analysis. Results: after determining the self-efficacy attributes in the family-center empowerment model, a category matrix was developed and the codes are placed in subcategories of the matrix. Most participants were female (58.0%), with a mean age of 49.50 years. The final analysis yielded a total of 247 units of analysis dispersed in eight subcategories belonging to four generic-categories. Conclusions: the findings of this study represent the dimensions of chronically-ill individuals’ self-efficacy that can be used to develop and implement programs for empowering chronic ill patients.
Is It Possible to Maintain High Compliance with the Enhanced Recovery after Surgery (ERAS) Protocol?—A Cohort Study of 400 Consecutive Colorectal Cancer Patients
Authors: Pisarska Magdalena , Gajewska Natalia , Małczak Piotr , Wysocki Michał , Major Piotr , Milian-Ciesielska Katarzyna , Budzyński Andrzej , Pędziwiatr Michał
Published: November 2018

The aim of our study was to evaluate the implementation and degree of adherence to the Enhanced Recovery after Surgery (ERAS) protocol in a group of 400 patients operated laparoscopically for colorectal cancer, and to assess its impact on the short-term results. The prospective study included patients with histologically confirmed colorectal cancer undergoing elective laparoscopic resection from years 2012 to 2017. For the purpose of further analysis, patients were divided into four groups: 100 consecutive patients were in each group. There were no statistically significant differences between groups in demographic parameters. The mean compliance with the ERAS protocol in the entire study group was 84.8%. Median adherence differed between the groups 76.9% vs. 92.3% vs. 84.6% vs. 84.6%, respectively (p < 0.0001). There were statistically significant differences between groups in the tolerance of oral diet (54% vs. 83% vs. 83% vs. 64%) and mobilization (74% vs. 92% vs. 91% vs. 94%) on the first postoperative day. In subsequent groups, time to first flatus decreased (2.5 vs. 2.1 vs. 2.0 vs. 1.7 days, p = 0.0001). There were no statistical differences in the postoperative morbidity rate between groups (p = 0.4649). The median length of hospital stay in groups was 5 vs. 4 vs. 4 vs. 4 days, respectively (p = 0.0025). Maintaining high compliance with the ERAS protocol is possible, despite the slight decrease that occurs within a few years after its implementation. This decrease in compliance does not affect short-term results, which are comparable to those shortly after overcoming the learning curve.
Mortality Risks among Various Primary Renal Diseases in Children and Adolescents on Chronic Dialysis
Authors: Chou Hsin-Hsu , Chiou Yuan-Yow , Chiou Yee-Hsuan , Tain You-Lin , Wang Hsin-Hui , Yu Mei-Ching , Hsu Chih-Cheng , Lin Ching-Yuang
Published: November 2018

There is little information available on the association between primary renal disease (PRD) and long-term mortality in the pediatric dialysis population. The objective of this study was to explore mortality risks in children and adolescents on chronic dialysis, specifically focused on the risk of various PRDs. The study cohort included children and adolescents with end-stage renal disease (ESRD) (aged < 20 years) who had received dialysis for at least 90 days between 2000 and 2014 and were identified from Taiwan’s National Health Insurance medical claims. A total of 530 children and adolescents were included in the study. The median age of the included patients was 13.6 years and 305 (57.5%) patients were males. One hundred and seven patients died during the follow-up period and the median survival time was 6.0 years. Mortality was highest in the youngest patients. For patients with the following PRDs, mortality was significantly higher than that in patients with primary glomerulonephritis: secondary glomerulonephritis (adjusted hazard ratio (aHR): 2.50; 95% confidence interval (CI): 1.03–6.08), urologic disorder (aHR: 4.77; 95% CI: 1.69–13.46), and metabolic diseases (aHR: 5.57; 95% CI: 1.84–16.85). Several kinds of PRDs appear to have high mortality risks in the pediatric dialysis population. These differences in mortality risk highlight the importance of the focused clinical management of these high-risk subgroups.
Seemingly Connected, Obviously Separate: The Parallel Realities of the UN Global Compact and the Multilateral Regimes in Water Governance
Authors: Samvel Gor
Published: November 2018

The UN Global Compact, being an institutional innovation in global governance, invites businesses to voluntarily commit to a selection of principles, rooted in multilateral regimes. Such commitment is expected to improve business practices and by that to close gaps in global governance. This spawns an expectation that through UN Global Compact business and multilateral treaty regimes will engage in mutually fertilizing and potentially coherent interaction to overcome the shortfalls of global governance. The current paper looks into this alleged interaction in the field of water stewardship and access to water. It explores first, the conceptual interdependence of the UN Global Compact and multilateral regimes in the respective fields and second, the ways in which the business practices reported under the UN Global Compact contribute to the advancement of the rules and principles thereof. The paper finds that the traditional multilateral systems and the innovative governance platform share an identical conceptual narrative but exist as separate realities on operational level. From the latter perspective the UN Global Compact might risk deepening governance gaps rather than close them.
G-Protein Coupled Receptor Protein Synthesis on a Lipid Bilayer Using a Reconstituted Cell-Free Protein Synthesis System
Authors: Gessesse Belay , Nagaike Takashi , Nagata Koji , Shimizu Yoshihiro , Ueda Takuya
Published: November 2018

Membrane proteins are important drug targets which play a pivotal role in various cellular activities. However, unlike cytosolic proteins, most of them are difficult-to-express proteins. In this study, to synthesize and produce sufficient quantities of membrane proteins for functional and structural analysis, we used a bottom-up approach in a reconstituted cell-free synthesis system, the PURE system, supplemented with artificial lipid mimetics or micelles. Membrane proteins were synthesized by the cell-free system and integrated into lipid bilayers co-translationally. Membrane proteins such as the G-protein coupled receptors were expressed in the PURE system and a productivity ranging from 0.04 to 0.1 mg per mL of reaction was achieved with a correct secondary structure as predicted by circular dichroism spectrum. In addition, a ligand binding constant of 27.8 nM in lipid nanodisc and 39.4 nM in micelle was obtained by surface plasmon resonance and the membrane protein localization was confirmed by confocal microscopy in giant unilamellar vesicles. We found that our method is a promising approach to study the different classes of membrane proteins in their native-like artificial lipid bilayer environment for functional and structural studies.
Exposed Areas Above Sea Level on Earth >3.5 Gyr Ago: Implications for Prebiotic and Primitive Biotic Chemistry
Authors: Bada Jeffrey L. , Korenaga Jun
Published: November 2018

How life began on Earth is still largely shrouded in mystery. One of the central ideas for various origins of life scenarios is Darwin’s “warm little pond”. In these small bodies of water, simple prebiotic compounds such as amino acids, nucleobases, and so on, were produced from reagents such as hydrogen cyanide and aldehydes/ketones. These simple prebiotic compounds underwent further reactions, producing more complex molecules. The process of chemical evolution would have produced increasingly complex molecules, eventually yielding a molecule with the properties of information storage and replication prone to random mutations, the hallmark of both the origin of life and evolution. However, there is one problematic issue with this scenario: On the Earth >3.5 Gyr ago there would have likely been no exposed continental crust above sea level. The only land areas that protruded out of the oceans would have been associated with hotspot volcanic islands, such as the Hawaiian island chain today. On these long-lived islands, in association with reduced gas-rich eruptions accompanied by intense volcanic lightning, prebiotic reagents would have been produced that accumulated in warm or cool little ponds and lakes on the volcano flanks. During seasonal wet–dry cycles, molecules with increasing complexity could have been produced. These islands would have thus been the most likely places for chemical evolution and the processes associated with the origin of life. The islands would eventually be eroded away and their chemical evolution products would have been released into the oceans where Darwinian evolution ultimately produced the biochemistry associated with all life on Earth today.
Catalytic/Protective Properties of Martian Minerals and Implications for Possible Origin of Life on Mars
Authors: Fornaro Teresa , Steele Andrew , Brucato John Robert
Published: November 2018

Minerals might have played critical roles for the origin and evolution of possible life forms on Mars. The study of the interactions between the “building blocks of life” and minerals relevant to Mars mineralogy under conditions mimicking the harsh Martian environment may provide key insight into possible prebiotic processes. Therefore, this contribution aims at reviewing the most important investigations carried out so far about the catalytic/protective properties of Martian minerals toward molecular biosignatures under Martian-like conditions. Overall, it turns out that the fate of molecular biosignatures on Mars depends on a delicate balance between multiple preservation and degradation mechanisms, often regulated by minerals, which may take place simultaneously. Such a complexity requires more efforts in simulating realistically the Martian environment in order to better inspect plausible prebiotic pathways and shed light on the nature of the organic compounds detected both in meteorites and on the surface of Mars through in situ analysis.
Effect of Electropulsing Treatment on the Fatigue Crack Growth Behavior of Copper
Authors: Yin Yan , Chen Haibo , Morita Yasuyuki , Toku Yuhki , Ju Yang
Published: November 2018

Crack propagation was quantitatively evaluated to investigate the effect of electropulsing treatment (EPT) on fatigue crack growth of copper specimens. Varying fatigue cycles were obtained under six different load levels. The crack lengths were measured under two load levels to examine the effect of cyclic stress. The microhardness was measured around the vicinity of the crack tip. Furthermore, the fracture surface was observed by scanning electron microscopy. Results show that EPT with electric current density of 150 A/mm2 enhances the high-cycle fatigue life, and the effect tends to increase with the decrease in cyclic stress. Vickers microhardness (HV) near the crack tip decreases to normal levels after treatment, and the approaching cracks on two sides can be observed. Local annealing and recrystallization occur around the fatigue crack tip. Accordingly, crack propagation can be delayed, and fatigue life can be prolonged by EPT.
Correction: Stencel, R., et al. Properties of Experimental Dental Composites Containing Antibacterial Silver-Releasing Filler. Materials 2018, 11, 1031
Authors: Stencel Robert , Kasperski Jacek , Pakieła Wojciech , Mertas Anna , Bobela Elżbieta , Barszczewska-Rybarek Izabela , Chladek Grzegorz
Published: November 2018

In the published article, “Properties of Experimental Dental Composites Containing Antibacterial Silver-Releasing Filler” [...]
Microstructure and Shear Strength of Brazing TiAl/Si3N4 Joints with Ag-Cu Binary Alloy as Filler Metal
Authors: Dong Duo , Zhu Dongdong , Wang Ye , Wang Gang , Wu Peng , He Qing
Published: November 2018

Vacuum brazing of TiAl intermetallic alloy to Si3N4 ceramics was performed using Ag-28Cu (wt.%) filler alloy. The brazing joints obtained at different brazing temperatures were studied in this work. The microstructure and the shear strength were analyzed in detail. The results show that the brazed joints could be divided into three regions: AlCu2Ti reaction layer near the Ti-48Al-2Cr-2Nb alloy, a typical Ag-Cu eutectic structure and a thin continuous TiN + Ti5Si3 reaction layer near the Si3N4 ceramics. The microstructure varied as the brazing temperature was increased from 1153 K/15 min to 1193 K/15 min. The shear strength of the joints first increased as the brazing temperature increased from 1153 K to 1173 K, and then decreased. The maximum shear strength reached 105.5 MPa at 1173 K/15 min and the mechanism was discussed.
Dephosphorization Behavior of High-Phosphorus Oolitic Hematite-Solid Waste Containing Carbon Briquettes during the Process of Direct Reduction-Magnetic Separation
Authors: Cao Yunye , Zhang Yiran , Sun Tichang
Published: November 2018

In this paper, the process of direct reduction roasting using magnetic separation to produce direct reduction iron (DRI) from high-phosphorus oolitic hematite, using coal slime and blast furnace dust as reductant, is investigated. The possible use of slime coal and blast furnace dust as reductant and the dephosphorization behavior during the process of direct reduction was studied. Experimental results showed that both blast furnace dust and coal slime can be used as reductant under certain conditions in the process. The dephosphorization mechanism of blast furnace dust and coal slime were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM)-energy dispersive X-ray spectroscopy (EDS). A DRI with 91.88 wt. % iron grade, 88.38% iron recovery and 0.072 wt. % P can be obtained with 30 wt. % blast furnace dust as reductant. The program not only used blast furnace dust but also recovered iron from blast furnace dust and high-phosphorus oolitic hematite. The analysis results revealed that phosphorus is distributed in gangue mineral and fluorapatite when blast furnace dust is used as reductant. Phosphorus-bearing minerals were not reduced to phosphorus element when the blast furnace dust was the reductant, but part of the fluorapatite reduced to phosphorus which smelt into metallic iron with coal slime as reductant. This led to a high phosphorus content of DRI. This research could provide support to the idea concept for recycling of carbon-containing solid waste and to assist the effective recovery of refractory iron ore by direct reduction–magnetic separation.
Atomistic Simulations of Pure Tin Based on a New Modified Embedded-Atom Method Interatomic Potential
Authors: Ko Won-Seok , Kim Dong-Hyun , Kwon Yong-Jai , Lee Min
Published: November 2018

A new interatomic potential for the pure tin (Sn) system is developed on the basis of the second-nearest-neighbor modified embedded-atom-method formalism. The potential parameters were optimized based on the force-matching method utilizing the density functional theory (DFT) database of energies and forces of atomic configurations under various conditions. The developed potential significantly improves the reproducibility of many fundamental physical properties compared to previously reported modified embedded-atom method (MEAM) potentials, especially properties of the β phase that is stable at the ambient condition. Subsequent free energy calculations based on the quasiharmonic approximation and molecular-dynamics simulations verify that the developed potential can be successfully applied to study the allotropic phase transformation between α and β phases and diffusion phenomena of pure tin.
Finite Element Simulation of High-Speed Blow Forming of an Automotive Component
Authors: Majidi Omid , Jahazi Mohammad , Bombardier Nicolas
Published: November 2018

High-speed blow forming (HSBF) is a new technology for producing components with complex geometries made of high strength aluminum alloy sheets. HSBF is considered a hybrid-superplastic forming method, which combines crash forming and gas blow forming. Due to its novelty, optimization of the deformation process parameters is essential. In this study, using the finite element (FE) code ABAQUS, thinning of an aluminum component produced by HSBF under different strain rates was investigated. The impact of element size, variation of friction coefficient, and material constitutive model on thinning predictions were determined and quantified. The performance of the FE simulations was validated through forming of industrial size parts with a complex geometry for the three investigated strain rates. The results indicated that the predictions are sensitive to the element size and the coefficient of friction. Remarkably, compared to a conventional power law model, the variable m-value viscoplastic (VmV) model could precisely predict the thickness variation of the industrial size component.
Numerical Simulation of Electromagnetic Field in Round Bloom Continuous Casting with Final Electromagnetic Stirring
Authors: Ren Bingzhi , Chen Dengfu , Xia Wentang , Wang Hongdan , Han Zhiwei
Published: November 2018

A 3D mathematical model was developed to simulate the electromagnetic field in Φ600 mm round bloom continuous casting with final electromagnetic stirring (F-EMS), and the model was verified using measured data for the magnetic flux density in the stirrer centre. The distribution of electromagnetic force and the influence of current intensity and frequency were investigated. The results show that the Joule heat generated by F-EMS is very small and its influence on secondary cooling heat transfer in the stirring zone can be ignored. With an increase in current frequency, the electromagnetic force density at R/2 and R/3 of the Φ600 mm round bloom first increases and then decreases, reaching a maximum at 10 Hz.
The Effect of Processing Pass on the Microstructure and Mechanical Properties of a Friction Stir Processed As-Cast Mg-6 wt % Sn Alloy
Authors: Zhang Yang , Chen Xiaoyang , Qin Xiyun , Li Feilong , Lu Yalin , Li Xiaoping
Published: November 2018

In this study, as-cast Mg-6 wt % Sn alloy is subjected to one-pass and two-pass friction stir processing (FSP). The effect of processing pass on microstructure and mechanical properties of FSP Mg-6Sn alloy is investigated. It is found that one-pass FSP leads to the breakage and partial dissolution of the Mg2Sn phase in the stir zone (SZ) and two-pass FSP leads to the further dissolution and dynamic precipitation of the Mg2Sn phase. Dynamic recrystallization (DRX) takes place in the SZ of an Mg-6Sn alloy undergoing FSP. Compared to one-pass FSP, two-pass FSP brings about further grain refinement in the SZ. A strong {0001} basal texture is developed in the SZ of a Mg-6Sn alloy from FSP and the change of the sample region or processing pass has little influence on the texture. Compared to an as-cast Mg-6Sn sample, one-pass FSP brings about significant improvement in mechanical properties. Two-pass FSP leads to the further increase in yield strength (YS) and ultimate tensile strength (UTS) but elongation (EL) is reduced. The continuous increase in strength is attributed to the grain refinement and the dissolution and dynamic precipitation of Mg2Sn phase achieved by FSP.
Reduction of Parasitic Capacitance of A PDMS Capacitive Force Sensor
Authors: Nagatomo Tatsuho , Miki Norihisa
Published: November 2018

Polymer-based flexible micro electro mechanical systems (MEMS) tactile sensors have been widely studied for a variety of applications, such as medical and robot fields. The small size and flexibility are of great advantage in terms of accurate measurement and safety. Polydimethylsiloxane (PDMS) is often used as the flexible structural material. However, the sensors are likely subject to large parasitic capacitance noise. The smaller dielectric constant leads to smaller influences of parasitic capacitance and a larger signal-to-noise ratio. In this study, the sensor underwent ultraviolet (UV) exposure, which changes Si–CH3 bonds in PDMS to Si–O, makes PDMS nanoporous, and leads to a low dielectric constant. In addition, we achieved further reduction of the dielectric constant of PDMS by washing it with an ethanol–toluene buffer solution after UV exposure. This simple but effective method can be readily applicable to improve the signal-to-noise ratio of PDMS-based flexible capacitive sensors. In this study, we propose reduction techniques for the dielectric constant of PDMS and applications for flexible capacitive force sensors.
The Effect of Ionic Strength and Sraq upon the Uptake of Ra during the Recrystallization of Barite
Authors: Brandt Felix , Klinkenberg Martina , Poonoosamy Jenna , Weber Juliane , Bosbach Dirk
Published: November 2018

Recrystallization and solid-solution formation with barite is considered as relevant retention mechanism for 226Ra in long-term scenarios of nuclear waste management. Here, we studied the effect of ionic strength and the presence of Sr in solution upon the Ra-uptake kinetics and final Ra concentrations in solution by recrystallizing barite in solution with varying Sr and NaCl concentration and temperature for up to 1000 days. Final Ra-concentrations were interpreted based on thermodynamic modelling. Our results indicate a slight decrease of the retention potential of barite for Ra but little effect on the uptake kinetics due to the increase of ionic strength from. 0.1 mol/kg to 1.0 mol/kg of NaCl. The final concentrations at solid/liquid ratio of 0.5 g/kg are well described based on available thermodynamic models whereas at 5 g/kg additional Ra uptake probably due to kinetic effects was observed. On the contrary, the presence of Sr in solution can have a significant inhibiting kinetic effect on the uptake kinetics and lower the final Ra-uptake. In some cases, with low solid/liquid ratio or at ambient conditions, Sr completely inhibits barite recrystallization. In all other cases, Ra, Ba and Sr were taken up as thermodynamically predicted at the end of the experiments.
Exogenous Melatonin Mitigates Methyl Viologen-Triggered Oxidative Stress in Poplar Leaf
Authors: Ding Fei , Wang Gang , Zhang Shuoxin
Published: November 2018

As a ubiquitous molecule, melatonin plays a crucial role in tolerance to multiple stresses in plants. In the present work, we report the role of exogenous melatonin in relieving oxidative stress induced by methyl viologen (MV) in poplar (Populus alba × Populus glandulosa) leaf. Leaf discs pretreated with melatonin exhibited increased tolerance to MV-mediated oxidative stress. It was observed that melatonin pretreatment effectively reduced membrane damage and lipid oxidation as demonstrated by decreased relative electrolyte leakage and malonaldehyde content in poplar leaf discs. Exogenous melatonin also stimulated activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX), and enhanced accumulation of non-enzymatic antioxidants of AsA and GSH in leaf discs exposed to MV. In addition, pretreatment of melatonin prompted expression of genes for those antioxidant enzymes. Notably, exogenous melatonin increased expression of P5CS, a key gene for proline biosynthesis, under MV treatment. It was further observed that pretreatment with melatonin boosted activity of P5CS as well as accumulation of proline in leaf discs under MV-mediated oxidative stress. Collectively, this work provides evidence for the ameliorative effect of melatonin on MV-induced oxidative stress in poplar leaf.
Smart and Functional Conducting Polymers: Application to Electrorheological Fluids
Authors: Lu Qi , Han Wen Jiao , Choi Hyoung Jin
Published: November 2018

Electro-responsive smart electrorheological (ER) fluids consist of electrically polarizing organic or inorganic particles and insulating oils in general. In this study, we focus on various conducting polymers of polyaniline and its derivatives and copolymers, along with polypyrrole and poly(ionic liquid), which are adopted as smart and functional materials in ER fluids. Their ER characteristics, including viscoelastic behaviors of shear stress, yield stress, and dynamic moduli, and dielectric properties are expounded and appraised using polarizability measurement, flow curve testing, inductance-capacitance-resistance meter testing, and several rheological equations of state. Furthermore, their potential industrial applications are also covered.
Simultaneous Identification and Dynamic Analysis of Saccharides during Steam Processing of Rhizomes of Polygonatum cyrtonema by HPLC–QTOF–MS/MS
Authors: Jin Jian , Lao Jia , Zhou Rongrong , He Wei , Qin You , Zhong Can , Xie Jing , Liu Hao , Wan Dan , Zhang Shuihan , Qin Yuhui
Published: November 2018

The sweet rhizomes of Polygonatum cyrtonema are widely used as a tonic and functional food. A sensitive and rapid analytical method was developed for simultaneous identification and dynamic analysis of saccharides during steam processing in P. cyrtonema using HPLC–QTOF–MS/MS. Fructose, sorbitol, glucose, galactose, sucrose, and 1-kestose were identified, as well as a large number of oligosaccharides constituted of fructose units through β-(2→1) or β-(2→6). Polysaccharides and oligosaccharides were decomposed to monosaccharides during a steaming process, since the contents of glucose, galactose, and fructose were increased, while those of sucrose, 1-kestose, and polysaccharides were decreased. The high content of fructose was revealed to be the main determinant for increasing the level of sweetness after steaming. The samples of different repeated steaming times were shown to be well grouped and gradually shift along the PC1 (72.4%) axis by principal component analysis. The small-molecule saccharides, especially fructose, could be considered as markers for the steaming process of rhizomes of P. cyrtonema.
Single-Electron Redox Chemistry on the [Cp*Rh] Platform Enabled by a Nitrated Bipyridyl Ligand
Authors: Moore William N. G. , Henke Wade C. , Lionetti Davide , Day Victor W. , Blakemore James D.
Published: November 2018

[Cp*Rh] complexes (Cp* = pentamethylcyclopentadienyl) are attracting renewed interest in coordination chemistry and catalysis, but these useful compounds often undergo net two-electron redox cycling that precludes observation of individual one-electron reduction events. Here, we show that a [Cp*Rh] complex bearing the 4,4′-dinitro-2,2′-bipyridyl ligand (dnbpy) (3) can access a distinctive manifold of five oxidation states in organic electrolytes, contrasting with prior work that found no accessible reductions in aqueous electrolyte. These states are readily generated from a newly isolated and fully characterized rhodium(III) precursor complex 3, formulated as [Cp*Rh(dnbpy)Cl]PF6. Single-crystal X-ray diffraction (XRD) data, previously unavailable for the dnbpy ligand bound to the [Cp*Rh] platform, confirm the presence of both [η5-Cp*] and [κ2-dnbpy]. Four individual one-electron reductions of 3 are observed, contrasting sharply with the single two-electron reductions of other [Cp*Rh] complexes. Chemical preparation and the study of the singly reduced species with electronic absorption and electron paramagnetic resonance spectroscopies indicate that the first reduction is predominantly centered on the dnbpy ligand. Comparative cyclic voltammetry studies with [NBu4][PF6] and [NBu4][Cl] as supporting electrolytes indicate that the chloride ligand can be lost from 3 by ligand exchange upon reduction. Spectroelectrochemical studies with ultraviolet (UV)-visible detection reveal isosbestic behavior, confirming the clean interconversion of the reduced forms of 3 inferred from the voltammetry with [NBu4][PF6] as supporting electrolyte. Electrochemical reduction in the presence of triethylammonium results in an irreversible response, but does not give rise to catalytic H2 evolution, contrasting with the reactivity patterns observed in [Cp*Rh] complexes bearing bipyridyl ligands with less electron-withdrawing substituents.
Amide Activation in Ground and Excited States
Authors: Kovács Ervin , Rózsa Balázs , Csomos Attila , Csizmadia Imre G. , Mucsi Zoltán
Published: November 2018

Not all amide bonds are created equally. The purpose of the present paper is the reinterpretation of the amide group by means of two concepts: amidicity and carbonylicity. These concepts are meant to provide a new viewpoint in defining the stability and reactivity of amides. With the help of simple quantum-chemical calculations, practicing chemists can easily predict the outcome of a desired process. The main benefit of the concepts is their simplicity. They provide intuitive, but quasi-thermodynamic data, making them a practical rule of thumb for routine use. In the current paper we demonstrate the performance of our methods to describe the chemical character of an amide bond strength and the way of its activation methods. Examples include transamidation, acyl transfer and amide reductions. Also, the method is highly capable for simple interpretation of mechanisms for biological processes, such as protein splicing and drug mechanisms. Finally, we demonstrate how these methods can provide information about photo-activation of amides, through the examples of two caged neurotransmitter derivatives.
Spectroscopic Studies of Dual Fluorescence in 2-(4-Fluorophenylamino)-5-(2,4-dihydroxybenzeno)-1,3,4-thiadiazole: Effect of Molecular Aggregation in a Micellar System
Authors: Czernel Grzegorz , Matwijczuk Arkadiusz , Karcz Dariusz , Górecki Andrzej , Niemczynowicz Agnieszka , Szcześ Aleksandra , Gładyszewski Grzegorz , Matwijczuk Alicja , Gładyszewska Bożena , Niewiadomy Andrzej
Published: November 2018

The article presents the results of spectroscopic studies focused on a selected compound from the 1,3,4-thiadiazole group—2-(4-fluorophenylamino)-5-(2,4-dihydroxybenzeno)-1,3,4-thia-diazole (FABT)—in a micellar system formed by Triton X-100, a non-ionic detergent. Fluorescence measurements revealed the phenomenon of dual fluorescence whose emergence is related to the particular molecular organisation of the compound, which depends both on the concentration of the detergent and, most of all, the concentration of the compound itself. Dual fluorescence of FABT in a micellar system was observed for the compound dissolved in a methanol aqueous system, i.e., an environment wherein the dual fluorescence of the compound had never been reported before. Based on the interpretation of UV-Vis electronic absorption, resonance light scattering (RLS), emission and excitation fluorescence spectra, as well as measurements of dynamic light scattering (DLS) and Principal Component Analysis (PCA), we were able to relate the occurrence of this effect to the process of molecular aggregation taking place between FABT molecules in the micellar system in question. Results of fluorescence spectra measurements and time-correlated single photon counting (TCSPC) indicate that dual fluorescence occurs at detergent concentrations necessary to form micellar systems, which in turn facilitate the process of aggregation of FABT molecules. The correlation between the observed fluorescence effects and the previous measurements performed for analogues from this group suggests the possibility of charge transfer (CT) within the range of detergent concentrations wherein the aforementioned fluorescence effects are observed. It ought to be emphasised that this type of fluorescence effects are relatively easy to induce, which predisposes this groups of fluorophores as ideal fluorescence probes in the context of biological samples.
Isolation and Identification of Potent Antidiabetic Compounds from Antrodia cinnamomea—An Edible Taiwanese Mushroom
Authors: Huang Hung Tse , Wang San-Lang , Nguyen Van Bon , Kuo Yao-Haur
Published: November 2018

Antrodia cinnamomea (AC), an edible Taiwanese mushroom, has been recognized as a valuable natural resource with vast biological and medicinal benefits. Recently, the hypoglycemic and anti-diabetic effects of AC were mentioned in several studies. However, no studies have investigated α-glucosidase inhibitors from AC fruiting bodies (ACFB) as they relate to type 2 diabetes (T2D) treatment. The purpose of this study was to gain evidence of potent α-glucosidase inhibitory effects, as well as isolate, identify and characterize the active compounds of ACFB. The MeOH extract of ACFB demonstrated potent α-glucosidase inhibitory activity, and possessed high pH stability (pH 2–11) and thermostable properties at 40–50 °C. Further purification led to the isolation of eight constituents from ACFB, identified as: 25S-antcin K (1), 25R-antcin K (2), dehydrosulphurenic acid (3), 25S-antcin I (4), 25S-antcin B (5), 25R-antcin B (6), dehydroeburicoic acid (7) and eburicoic acid (8). Notably, the ACFB extract and its identified compounds, except 1, 4, and 6 demonstrated a greater effect (EC50 = 0.025–0.21 mg/mL) than acarbose (EC50 = 0.278 mg/mL). As such, these active compounds were determined to be new potent mushroom α-glucosidase inhibitors. These active compounds were also identified on the HPLC fingerprints of ACFB.
Sample Volume Reduction Using the Schwarzschild Objective for a Circular Dichroism Spectrophotometer and an Application to the Structural Analysis of Lysine-36 Trimethylated Histone H3 Protein
Authors: Izumi Yudai , Matsuo Koichi
Published: November 2018

With the increasing interest in scarce proteins, reducing the sample volume for circular dichroism (CD) spectroscopy has become desirable. Demagnification of the incident beam size is required to reduce the sample volume for CD spectroscopy detecting transmitted light passed through the sample. In this study, the beam size was demagnified using a focal mirror, and small-capacity sample cells were developed in an attempt to reduce the sample volume. The original beam size was 6 × 6 mm2; we successfully converged it to a size of 25 × 25 μm2 using the Schwarzschild objective (SO). The new sample cell and SO allowed the required sample volume to be reduced to 1/10 (15 → 1.5 μL), when using a 15 μm path length cell. By adopting a smaller sample cell, further sample reduction could be achieved. By using the SO system, the secondary structural contents of the lysine-36 trimethylated histone H3 protein were analyzed. The trimethylation induced the increment of helix structures and decrement of unordered structures. These structural alterations may play a role in regulating cellular function(s), such as DNA damage repair processes.
Analogues of Muraymycin Nucleoside Antibiotics with Epimeric Uridine-Derived Core Structures
Authors: Spork Anatol P. , Koppermann Stefan , Schier (née Wohnig) Stephanie , Linder Ruth , Ducho Christian
Published: November 2018

Nucleoside analogues have found widespread application as antiviral and antitumor agents, but not yet as antibacterials. Naturally occurring uridine-derived ‘nucleoside antibiotics’ target the bacterial membrane protein MraY, an enzyme involved in peptidoglycan biosynthesis and a promising target for the development of novel antibacterial agents. Muraymycins represent a nucleoside-peptide subgroup of such MraY-inhibiting natural products. As part of detailed structure-activity relationship (SAR) studies on muraymycins and their analogues, we now report novel insights into the effects of stereochemical variations in the nucleoside core structure. Using a simplified version of the muraymycin scaffold, it was shown that some formal inversions of stereochemistry led to about one order of magnitude loss in inhibitory potency towards the target enzyme MraY. In contrast, epimers of the core motif with retained inhibitory activity were also identified. These 5′,6′-anti-configured analogues might serve as novel chemically tractable variations of the muraymycin scaffold for the future development of uridine-derived drug candidates.
Influence of Ligand Functionalization of UiO-66-Based Metal-Organic Frameworks When Used as Sorbents in Dispersive Solid-Phase Analytical Microextraction for Different Aqueous Organic Pollutants
Authors: Taima-Mancera Iván , Rocío-Bautista Priscilla , Pasán Jorge , Ayala Juan H. , Ruiz-Pérez Catalina , Afonso Ana M. , Lago Ana B. , Pino Verónica
Published: November 2018

Four metal-organic frameworks (MOFs), specifically UiO-66, UiO-66-NH2, UiO-66-NO2, and MIL-53(Al), were synthesized, characterized, and used as sorbents in a dispersive micro-solid phase extraction (D-µSPE) method for the determination of nine pollutants of different nature, including drugs, phenols, polycyclic aromatic hydrocarbons, and personal care products in environmental waters. The D-µSPE method, using these MOFs as sorbents and in combination with high-performance liquid chromatography (HPLC) and diode-array detection (DAD), was optimized. The optimization study pointed out to UiO-66-NO2 as the best MOF to use in the multi-component determination. Furthermore, the utilization of isoreticular MOFs based on UiO-66 with the same topology but different functional groups, and MIL-53(Al) to compare with, allowed us for the first time to evaluate the influence of such functionalization of the ligand with regards to the efficiency of the D-µSPE-HPLC-DAD method. Optimum conditions included: 20 mg of UiO-66-NO2 MOF in 20 mL of the aqueous sample, 3 min of agitation by vortex and 5 min of centrifugation, followed by the use of only 500 µL of acetonitrile as desorption solvent (once the MOF containing analytes was separated), 5 min of vortex and 5 min of centrifugation. The validation of the D-µSPE-HPLC-DAD method showed limits of detection down to 1.5 ng·L−1, average relative recoveries of 107% for a spiked level of 1.50 µg·L−1, and inter-day precision values with relative standard deviations lower than 14%, for the group of pollutants considered.
Anti-Leishmanial and Cytotoxic Activities of a Series of Maleimides: Synthesis, Biological Evaluation and Structure-Activity Relationship
Authors: Fan Yongxian , Lu Yuele , Chen Xiaolong , Tekwani Babu , Li Xing-Cong , Shen Yinchu
Published: November 2018

In the present study, 45 maleimides have been synthesized and evaluated for anti-leishmanial activities against L. donovani in vitro and cytotoxicity toward THP1 cells. All compounds exhibited obvious anti-leishmanial activities. Among the tested compounds, there were 10 maleimides with superior anti-leishmanial activities to standard drug amphotericin B, and 32 maleimides with superior anti-leishmanial activities to standard drug pentamidine, especially compounds 16 (IC50 < 0.0128 μg/mL) and 42 (IC50 < 0.0128 μg/mL), which showed extraordinary efficacy in an in vitro test and low cytotoxicities (CC50 > 10 μg/mL). The anti-leishmanial activities of 16 and 42 were 10 times better than that of amphotericin B. The structure and activity relationship (SAR) studies revealed that 3,4-non-substituted maleimides displayed the strongest anti-leishmanial activities compared to those for 3-methyl-maleimides and 3,4-dichloro-maleimides. 3,4-dichloro-maleimides were the least cytotoxic compared to 3-methyl-maleimides and 3,4-non-substituted maleimides. The results show that several of the reported compounds are promising leads for potential anti-leishmanial drug development.
Anti-Obesity Effects of Medicinal and Edible Mushrooms
Authors: Ganesan Kumar , Xu Baojun
Published: November 2018

Obesity is a group of metabolic disorders caused by multiple factors, including heredity, diet, lifestyle, societal determinants, environment, and infectious agents, which can all lead to the enhancement of storage body fat. Excess visceral fat mass in adipose tissue generate several metabolic disorders, including cardiovascular diseases with chronic inflammation based pathophysiology. The objective of the current review is to summarize the cellular mechanisms of obesity that attenuate by antioxidant potentials of medicinal and edible mushrooms. Studies have showed that mushrooms potentially have antioxidant capacities, which increase the antioxidant defense systems in cells. They boost anti-inflammatory actions and thereby protect against obesity-related hypertension and dyslipidemia. The practice of regular consumption of mushrooms is effective in the treatment of metabolic syndrome, including obesity, and thus could be a good candidate for use in future pharmaceutical or nutraceutical applications.
Optimization of Regioselective α-Glucosylation of Hesperetin Catalyzed by Cyclodextrin Glucanotransferase
Authors: González-Alfonso José , Míguez Noa , Padilla J. , Leemans Laura , Poveda Ana , Jiménez-Barbero Jesús , Ballesteros Antonio , Sandoval Georgina , Plou Francisco
Published: November 2018

The regioselective α-glucosylation of hesperetin was achieved by a transglycosylation reaction catalyzed by cyclodextrin glucanotransferase (CGTase) from Thermoanaerobacter sp. using soluble starch as glucosyl donor. By combining mass spectrometry (ESI-TOF) and 2D-NMR analysis, the main monoglucosylated derivative was fully characterized (hesperetin 7-O-α-d-glucopyranoside). In order to increase the yield of monoglucoside, several reaction parameters were optimized: Nature and percentage of cosolvent, composition of the aqueous phase, glucosyl donor, temperature, and the concentrations of hesperetin and soluble starch. Under the optimal conditions, which included the presence of 30% of bis(2-methoxyethyl) ether as cosolvent, the maximum concentration of monoglucoside was approximately 2 mM, obtained after 24 h of reaction. To our knowledge, this is the first report of direct glucosylation of hesperetin employing free enzymes instead of whole cells.
Size Limit and Energy Analysis of Nanoparticles during Wrapping Process by Membrane
Authors: Meng Xinpei , Li Xinlei
Published: November 2018

The wrapping of nanoparticles (NPs) by a membrane is a phenomenon of widespread and generic interest in biology, as well as in a variety of technological applications, such as drug delivery, clinical diagnostics, and biomedical imaging. However, the mechanisms of the interaction between the membrane and NPs are not well understood yet. In this paper, we have presented an analytic thermodynamic model to investigate the wrapping process of NPs by a cell membrane. It is found that the bending energy of the deformed membrane increases nonlinearly with increasing wrapping degree, which leads to a free energy barrier for the wrapping. On the basis of analysis results, the wrapping of NPs can be divided into three types, i.e., impossible wrapping, barrier wrapping, and free wrapping. Furthermore, a phase diagram for the wrapping of NPs has been constructed, which clarifies the interrelated effects of the size and the ligand density of NPs. We hope that this work can provide some help in understanding the physical mechanism of the wrapping of NPs.
Highly Photoluminescent and Stable N-Doped Carbon Dots as Nanoprobes for Hg2+ Detection
Authors: Rao Longshi , Tang Yong , Lu Hanguang , Yu Shudong , Ding Xinrui , Xu Ke , Li Zongtao , Zhang Jin Z.
Published: November 2018

We developed a microreactor with porous copper fibers for synthesizing nitrogen-doped carbon dots (N-CDs) with a high stability and photoluminescence (PL) quantum yield (QY). By optimizing synthesis conditions, including the reaction temperature, flow rate, ethylenediamine dosage, and porosity of copper fibers, the N-CDs with a high PL QY of 73% were achieved. The PL QY of N-CDs was two times higher with copper fibers than without. The interrelations between the copper fibers with different porosities and the N-CDs were investigated using X-ray photoelectron spectroscopy (XPS) and Fourier Transform infrared spectroscopy (FTIR). The results demonstrate that the elemental contents and surface functional groups of N-CDs are significantly influenced by the porosity of copper fibers. The N-CDs can be used to effectively and selectively detect Hg2+ ions with a good linear response in the 0~50 μM Hg2+ ions concentration range, and the lowest limit of detection (LOD) is 2.54 nM, suggesting that the N-CDs have great potential for applications in the fields of environmental and hazard detection. Further studies reveal that the different d orbital energy levels of Hg2+ compared to those of other metal ions can affect the efficiency of electron transfer and thereby result in their different response in fluorescence quenching towards N-CDs.