bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Solution of Axisymmetric Inverse Heat Conduction Problem by the Trefftz Method
Authors: Hożejowska Sylwia , Piasecka Magdalena
Published: February 2020

In this paper, the issue of flow boiling heat transfer in an annular minigap was discussed. The main aim of the paper was determining the boiling heat transfer coefficient at the HFE-649 fluid–heater contact during flow along an annular minigap. The essential element of the experimental stand was a test section vertically oriented with the minigap 2 mm wide. Thermocouples were used to measure the temperature of the heater and fluid at the inlet and the outlet to the minigap. The mathematical model assumed that the fluid flow was laminar and the steady–state heat transfer process was axisymmetric. The temperatures of the heated surface and of the flowing fluid were assumed to fulfill energy equations with adequate boundary conditions. The problem was solved by the Trefftz method. The local heat transfer coefficients at the fluid–test surface interface were calculated due to the third kind boundary condition at the saturated boiling. Graphs were used to illustrate: the measurement of the heater surface temperature, 2D temperature distributions in the pipe and fluid, and the heat transfer coefficient as a function of the distance from the minigap inlet. The measurement uncertainties and accuracy of the heat transfer coefficient determination were estimated.
Income and Ecosystem Service Comparisons of Refined National and Agroforestry Accounting Frameworks: Application to Holm Oak Open Woodlands in Andalusia, Spain
Authors: Campos Pablo , Álvarez Alejandro , Oviedo José L. , Ovando Paola , Mesa Bruno , Caparrós Alejandro
Published: February 2020

There is growing consensus regarding the implementation of a new statistical framework for environmental-economic accounting to improve ecosystem related policies. As the standard System of National Accounts (SNA) fails to measure the economic contribution of ecosystems to the total income of individuals, governments recognize the need to expand the standard SNA through the ongoing System of Environmental Economic Accounting (SEEA). Based on the authors’ own data, this study focuses on linking 15 economic activities and 12 ecosystem services for a holm oak (Quercus ilex L.) open woodlands (HOW) ecosystem type in Andalusia, Spain. We emphasize that overcoming the challenges of multiple use is preferable to measuring single ecosystem products for improving habitat conservation policies. The objectives of this paper are to measure and compare the environmental assets, ecosystem services, and incomes at basic and social prices by applying a refined version of the standard System of National Accounts (rSNA) and the authors’ Agroforestry Accounting System (AAS), respectively, to HOW. Considering intermediate products and consumptions of HOW farmer and government activities, we find that the rSNA ecosystem services and environmental incomes at basic prices are 123.3 €/ha and −28.0 €/ha, respectively, while those of the AAS at social prices are 442.2 €/ha and 250.8 €/ha. Given advances in non-market valuation techniques, we show that an expanded definition of economic activities can be applied to measure the contribution to total income of managed natural areas taking into account the multiple uses of the ecosystem type. However, HOW sustainability continues to be a challenging issue that requires ecological threshold indicators to be identified, not only because of the economic implications but also because they provide vital information on which to base policy implementation.
Transcriptomics Reveal Altered Metabolic and Signaling Pathways in Podocytes Exposed to C16 Ceramide-Enriched Lipoproteins
Authors: Hammad Samar M. , Twal Waleed O. , Arif Ehtesham , Semler Andrea J. , Klein Richard L. , Nihalani Deepak
Published: February 2020

Sphingolipids are bioactive lipids associated with cellular membranes and plasma lipoproteins, and their synthesis and degradation are tightly regulated. We have previously determined that low plasma concentrations of certain ceramide species predict the development of nephropathy in diabetes patients with normal albumin excretion rates at baseline. Herein, we tested the hypothesis that altering the sphingolipid content of circulating lipoproteins can alter the metabolic and signaling pathways in podocytes, whose dysfunction leads to an impairment of glomerular filtration. Cultured human podocytes were treated with lipoproteins from healthy subjects enriched in vitro with C16 ceramide, or D-erythro 2-hydroxy C16 ceramide, a ceramide naturally found in skin. The RNA-Seq data demonstrated differential expression of genes regulating sphingolipid metabolism, sphingolipid signaling, and mTOR signaling pathways. A multiplex analysis of mTOR signaling pathway intermediates showed that the majority (eight) of the pathway phosphorylated proteins measured (eleven) were significantly downregulated in response to C16 ceramide-enriched HDL2 compared to HDL2 alone and hydroxy ceramide-enriched HDL2. In contrast, C16 ceramide-enriched HDL3 upregulated the phosphorylation of four intermediates in the mTOR pathway. These findings highlight a possible role for lipoprotein-associated sphingolipids in regulating metabolic and signaling pathways in podocytes and could lead to novel therapeutic targets in glomerular kidney diseases.
Geochemical Discrimination of Monazite Source Rock Based on Machine Learning Techniques and Multinomial Logistic Regression Analysis
Authors: Itano Keita , Ueki Kenta , Iizuka Tsuyoshi , Kuwatani Tatsu
Published: February 2020

Detrital monazite geochronology has been used in provenance studies. However, there are complexities in the interpretation of age spectra due to their wide occurrence in both igneous and metamorphic rocks. We use the multinomial logistic regression (MLR) and cross-validation (CV) techniques to establish a geochemical discrimination of monazite source rocks. The elemental abundance-based geochemical discrimination was tested by selecting 16 elements from granitic and metamorphic rocks. The MLR technique revealed that light rare earth elements (REEs), Eu, and some heavy REEs are important discriminators that reflect elemental fractionation during magmatism and/or metamorphism. The best model yielded a discrimination rate of ~97%, and the CV method validated this approach. We applied the discrimination model to detrital monazites from African rivers. The detrital monazites were mostly classified as granitic and of garnet-bearing metamorphic origins; however, their proportion of metamorphic origin was smaller than the proportion that was obtained by using the elemental-ratio-based discrimination proposed by Itano et al. in Chemical Geology (2018). Considering the occurrence of metamorphic rocks in the hinterlands and the different age spectra between monazite and zircon in the same rivers, a ratio-based discrimination would be more reliable. Nevertheless, our study demonstrates the advantages of machine-learning-based approaches for the quantitative discrimination of monazite.
Gamifying Motor Rehabilitation Therapies: Challenges and Opportunities of Immersive Technologies
Authors: Ferreira Bruno , Menezes Paulo
Published: February 2020

Recovering from a traumatic incident (e.g, a stroke) implies rigorous and demanding therapies to ensure recovery of the lost capabilities. Due to the lack of short-term visible results, stroke patients tend to lose interest in their recovery process and frequently do not follow their therapists’ suggestions to continue performing their training at home, between physiotherapy sessions. This article explores the extent to which common computer games or specifically crafted games can serve as a rehabilitation practice, but also how conventional therapeutic devices might be transformed to be incorporated into games. Furthermore, we propose a platform that follows the opportunity of creating serious games that are designed for stroke patients with reduced upper limb mobility while following the same principles of common therapeutic procedures. This platform was carefully built with the purpose of allowing patients to comply tele-rehabilitation and promoting the execution of the recommended training at home. Following these ideas, we integrated two carefully designed games that have been tested and validated in our previous works, and we added a top-layer characterized by an online back-end application for therapists that allows them to observe their patients’ progress over time and draw different conclusions.
A New Green Prospective of Non-orthogonal Multiple Access (NOMA) for 5G
Authors: Basnayake Vishaka , Jayakody Dushantha Nalin K. , Sharma Vishal , Sharma Nikhil , Muthuchidambaranathan P. , Mabed Hakim
Published: February 2020

Energy efficiency is a major concern in the emerging mobile cellular wireless networks since massive connectivity is to be expected with high energy requirements from the network operators. Non-orthogonal multiple access (NOMA) being the frontier multiple access scheme for 5G, there exists numerous research attempts on enhancing the energy efficiency of NOMA enabled wireless networks while maintaining its outstanding performance metrics such as high throughput, data rates and capacity maximized optimally.The concept of green NOMA is introduced in a generalized manner to identify the energy efficient NOMA schemes. These schemes will result in an optimal scenario in which the energy generated for communication is managed sustainably. Hence, the effect on the environment, economy, living beings, etc is minimized. The recent research developments are classified for a better understanding of areas which are lacking attention and needs further improvement. Also, the performance comparison of energy efficient, NOMA schemes against conventional NOMA is presented. Finally, challenges and emerging research trends, for energy efficient NOMA are discussed.
Biology of Pseudacteon Decapitating Flies (Diptera: Phoridae) That Parasitize Ants of the Solenopsis saevissima Complex (Hymenoptera: Formicidae) in South America
Authors: Chen Li , Porter Sanford D.
Published: February 2020

Pseudacteon flies (Diptera: Phoridae) parasitize individual ant workers, causing decapitation of the host during pupariation. Phorid flies that attack South American fire ants in the Solenopsis saevissima (Smith) complex are distributed across a wide range of habitats and climates associated with the geographical range of their hosts. Sympatric species sharing the same hosts often partition niche resources by season, active time of day, host size, and/or different host activities. They have the potential of being used for biological control of the imported fire ants in North America, Australia, and Asia.
Effects of Immobilization and Re-Mobilization on Knee Joint Arthrokinematic Motion Quality
Authors: Bączkowicz Dawid , Skiba Grzegorz , Falkowski Krzysztof , Domaszewski Przemysław , Selkow Noelle
Published: February 2020

Background: Knee immobilization is a common intervention for patients with traumatic injuries. However, it usually leads to biomechanical/morphological disturbances of articular tissues. These changes may contribute to declining kinetic friction-related quality of arthrokinematics; however, this phenomenon has not been analyzed in vivo and remains unrecognized. Thus, the aim of the present study is to investigate the effect of immobilization and subsequent re-mobilization on the quality of arthrokinematics within the patellofemoral joint, analyzed by vibroarthrography (VAG). Methods: Thirty-four patients after 6-weeks of knee immobilization and 37 controls were analyzed. The (VAG) signals were collected during knee flexion/extension using an accelerometer. Patients were tested on the first and last day of the 2-week rehabilitation program. Results: Immobilized knees were characterized by significantly higher values of all VAG parameters when compared to controls (p < 0.001) on the first day. After 2 weeks, the participants in the rehabilitation program that had immobilized knees showed significant improvement in all measurements compared to the baseline condition, p < 0.05. However, patients did not return to normal VAG parameters compared to controls. Conclusion: Immobilization-related changes within the knee cause impairments of arthrokinematic function reflected in VAG signal patterns. The alterations in joint motion after 6 weeks of immobilization may be partially reversible; however, the 2-week physiotherapy program is not sufficient for full recovery.
Effect of Sample Size and Crystal Orientation on the Fatigue Behaviour of Single Crystalline Microbeams
Authors: Rafael Velayarce Jorge , Motz Christian
Published: February 2020

Beam deflection experiments were used to systematically examine size effects on the low cyclic fatigue (LCF) deformation behaviour of micro-sized bending beams of copper (Cu) single crystals oriented for single slip, critical and coplanar double slip. We present cyclic hardening curves and fatigue surface roughness, as well as dislocations structures of the micro-sized beams with sizes between 1 and 15 µm. A clear crystal orientation and size effect on the cyclic hardening curves, surface roughness, and the dislocation microstructures were observed. Based on the experimental results, the fatigue damage in single slip orientations clearly decreased with decreasing the sample size, however, below a critical size regime, the surface damage suddenly increases. Additionally, samples with sizes larger than 5 µm clearly revealed, besides PSBs-like structures, the emergence of kink bands leading to larger surface roughness in comparison to the smaller ones. Fatigue surface damages in microcrystals oriented for critical double slip became more prevalent compared to single slip orientations. Quantitatively, the correlation of the fatigue surface damage was also demonstrated with the formation of PSBs-like structures.
Ultrasonic-Assisted Semi-Solid Forming Method and Microstructure Evolution of Aluminum/Copper Brazed Joints
Authors: Liang Yin , Pan Jiruan , Zhang Hua , Huang Peng , Wang Jun , Shi Yuxin , Chen Limin
Published: February 2020

Aluminum/Copper dissimilar metal connection devices have been widely used in equipment manufacturing. Ultrasonic vibration assisted semi-solid brazing technology is beneficial to improve brazing quality by using the good flow ability and strong deformation resistance of brazing alloy when it is in a semi-solid state. In this study, a new ultrasound-assisted high-frequency induction brazing method was used to braze aluminum and copper dissimilar metals under non-vacuum conditions with non-prefabrication of brazing filler metal. In a short time, uniform semi-solid brazed joint was obtained. Detailed investigations on the effects of aluminum-substrate side (Abbreviated as Al side) heat dissipation rate and ultrasonic vibration duration on the microstructure evolution and mechanical properties of semisolid weld were conducted. The results show that the welding seam obtained by the modification method increases the microstructure uniformity of brazing joint.
Effect of the t8/5 Cooling Time on the Properties of S960MC Steel in the HAZ of Welded Joints Evaluated by Thermal Physical Simulation
Authors: Mičian Miloš , Harmaniak Daniel , Nový František , Winczek Jerzy , Moravec Jaromír , Trško Libor
Published: February 2020

The heat input into the material during welding significantly affects the properties of high-strength steels in the near-weld zone. A zone of hardness decrease forms, which is called the soft zone. The width of the soft zone also depends on the cooling time t8/5. An investigation of the influence of welding parameters on the resulting properties of welded joints can be performed by thermal physical simulation. In this study, the effect of the cooling rate on the mechanical properties of the heat-affected zone of the steel S960MC with a thickness of 3 mm was investigated. Thermal physical simulation was performed on a Gleeble 3500. Three levels of cooling time were used, which were determined from the reference temperature cycle obtained by metal active gas welding (MAG). A tensile test, hardness measurement, impact test with fracture surface evaluation, and microstructural evaluation were performed to investigate the modified specimen thickness. The shortest time t8/5 = 7 s did not provide tensile and yield strength at the minimum required value. The absorbed energy after recalculation to the standard sample size of 10 × 10 mm was above the 27 J limit at −40 °C. The hardness profile also depended on the cooling rate and always had a softening zone.
Post-Processing Improvements for Mechanical, Microstructure, and Surface Properties of Steel
Authors: Lombardi Mariangela
Published: February 2020

Post-processing treatments of metallic materials play a key role in the achievement of high mechanical and surface properties of the final components and in the optimization of their behavior in service conditions [...]
WEDM of Copper for the Fabrication of Large Surface-Area Micro-Channels: A Prerequisite for the High Heat-Transfer Rate
Authors: Ahmed Naveed , Mughal Mohammad Pervez , Shoaib Waqar , Farhan Raza Syed , Alahmari Abdulrhman M.
Published: February 2020

To get the maximum heat transfer in real applications, the surface area of the micro-features (micro-channels) needs to be large as possible. It can be achieved by producing a maximum number of micro-channels per unit area. Since each successive pair of the micro-channels contain an inter-channels fin, therefore the inter-channels fin thickness (IFT) plays a pivotal role in determining the number of micro-channels to be produced in the given area. During machining, the fabrication of deep micro-channels is a challenge. Wire-cut electrical discharge machining (EDM) could be a viable alternative to fabricate deep micro-channels with thin inter-channels fins (higher aspect ratio) resulting in larger surface area. In this research, minimum IFT and the corresponding machining conditions have been sought for producing micro-channels in copper. The other attributes associated with the micro-channels have also been deeply investigated including the inter-channels fin height (IFH), inter-channels fin radius (IFR) and the micro-channels width (MCW). The results reveal that the inter-channels fin is the most critical feature to control during the wire electrical discharge machining (WEDM) of copper. Four types of fin shapes have been experienced, including the fins: broken at the top end, deflected at the top end, curled bend at the top, and straight with no/negligible deflection.
Characteristics of Organic Matter Particles and Organic Pores of Shale Gas Reservoirs: A Case Study of Longmaxi-Wufeng Shale, Eastern Sichuan Basin
Authors: Wang Guochang , Long Shengxiang , Peng Yongmin , Ju Yiwen
Published: February 2020

Heterogeneity of organic matter (OM), including size, type, and organic pores within OM, is being recognized along with increasing study using SEM images. Especially, the contribution of organic pores to the entire pore system should be better understood to aid in the evaluation of shale reservoirs. This research observed and quantitatively analyzed over 500 SEM images of 19 core samples from Longmaxi-Wufeng Shale in the eastern Sichuan Basin to summarize the features of OM particles and OM-hosted pores and their evolution during burial. The features of organic pores as well as the embedded minerals within OM particles enables to recognize four different type of OM particles. The organic pore features of each type of OM particles were quantitatively described using parameters such as pore size distribution (PSD), pore geometry, and organic porosity. The PSD of weakly or undeformed porous pyrobitumen indicates that the large organic pores (usually 200 nm to 1 um) is less common than small pores but the major contributor to organic porosity. The organic porosity of OM particles covers a large range of 1–35%, indicating a high heterogeneity among OM particles. Based on analysis of 81 OM particles, the average of organic porosity of the five samples were calculated and ranges from 3% to 12%. In addition, samples from well JY1 have higher organic porosity than JY8. These results helped to reveal how significant the organic pores are for shale gas reservoirs. In addition to presenting many examples of OM particles, this research should significantly improve the understanding of type and evolution of OM particles and contribution of OM-hosted pores to the entire pore system of high to over mature shale.
Mineralogical and Thermal Characterization of Kaolinitic Clays from Terra Alta (Catalonia, Spain)
Authors: Garcia-Valles Maite , Alfonso Pura , Martínez Salvador , Roca Núria
Published: February 2020

This research characterizes the kaolinitic clays from Cretaceous–Paleocene lateritic deposits of Terra Alta (south Catalonia) to evaluate their possible applications. The outcrops and quarries belong to the Horta de Sant Joan and Pinell de Brai areas. The chemical composition, mineralogy, rheological behavior, particle size distribution and plasticity are determined. The Fe and Ti4+ contents prevent them from being directly used as raw material for white ceramics. The mineralogy consists of kaolinite with quartz, illite, hematite, and minor K-feldspar and calcite. Most of the area comprises medium plastic clays that are classified as fired clays and can be used as ceramic and construction materials. In Horta de Sant Joan, a kaolinitic-rich level, up to 75 wt % of kaolinite, is highly crystalline with low plasticity and can be classified as flint clay, useful as a refractory clay. The evaluated kaolinitic clays can also be used to obtain a triaxial ceramic when they are mixed with feldspar to act as a fluxing agent and chamotte.
Microbial Origin of the Organic Matter Preserved in the Cayo Coco Lagoonal Network, Cuba
Authors: Bouton Anthony , Vennin Emmanuelle , Thomazo Christophe , Mathieu Olivier , Garcia Fabien , Jaubert Maxime , Visscher Pieter
Published: February 2020

The southern part of the tropical Cayo Coco Island (Cuba) hosts a complex, highly evaporative and marine-fed lagoonal network. In the easternmost lagoon of this network, hypersaline conditions favour the development of complex sedimentary microbial ecosystems within the water column at the bottom water-sediment interface and on the shore. Some of these ecosystems are producing microbial mats and biofilms with variable mineralisation rates, depending on their location. Since the mineralisation of these microbial deposits is rare, the sedimentary record does not provide a direct window on the evolution of these ecosystems or their distribution through space and time. However, microbial deposits also produce copious amounts of organic matter, which may be used to decipher any microbial-related origin within the sedimentary record. Microbial mats and biofilms were identified as the potential source of organic material in addition to the surrounding mangrove, soils and suspended particulate matter (SPM). The origin and evolution of the sedimentary organic matter preserved within the lagoonal sediments has been analysed using geochemical parameters such as elemental (TOC, TN and [C/N]atomic ratio) and isotopic (δ13Corg and δ15NTN) signals on four sedimentary cores retrieved from different locations in the lagoon and compared with the geochemical signatures of the potential sources. Despite the high potential for organic matter accumulation in the studied lagoon, the TOC and TN downcore values in sediments that were analysed (i.e., micritic muds and bioclastic sands) remain very low compared to the sediment-water interface. The relative contributions of the different potential sources of organic matter were estimated using [C/N]atomic ratios and δ13Corg values. The δ15NTN signature was discarded as a source signature as it records synsedimentary, early diagenetic, secondary evolution of the nitrogen signal associated with OM remineralisation (i.e., denitrification). Finally, among the microbial deposits, the slime recognised in the permanently submersed zone of the waterbody appears to be the main contributor to the organic matter preserved within the sediments of the lagoon. SPM, mainly composed of microbial-rich particles, also contribute and cannot be ruled out as a source.
The Potential Role of Colloidal Silica as a Depressant in Scheelite Flotation
Authors: Kupka Nathalie , Babel Bent , Rudolph Martin
Published: February 2020

The main challenge in scheelite flotation lies in the contamination of the concentrate by other calcium-bearing minerals, mainly calcite. To remedy this problem, sodium silicate is frequently used as a depressant. According to the literature, one hypothesis for the mechanism of water glass consists in its absorption onto calcite through colloidal silica formation, preventing hydrophobization by the collector. This short communication presents research conducted on the direct use of colloidal silica as a depressant in scheelite flotation. Colloidal silica is shown to have an impact on scheelite flotation, especially by depressing silicates.
Appraisal of Strategies for Dealing with the Physical Hazards of Abandoned Surface Mine Excavations: A Case Study of Frankie and Nyala Mines in South Africa
Authors: Mhlongo Sphiwe Emmanuel , Amponsah-Dacosta Francis , Kadyamatimba Armstrong
Published: February 2020

In order to improve the safety status and the quality of the landscape affected by surface mining, it is important that practical strategies for dealing with the excavations are identified. The aim of the work presented in this paper was to carry out an appraisal of the strategies for addressing the physical hazards of abandoned surface mine excavations in two mines in the Limpopo Province, South Africa. The method used involved carrying out field characterization of the current state and uses of the excavations, as well as their physical hazards of the surface mine excavations in the study area. The characterization took into consideration. Possible strategies for addressing the physical hazards of the excavations are identified, and their strengths, weaknesses, opportunities, and threats (SWOT) analyzed. The Quantitative Strategic Planning Matrix (QSPM) was performed on each of the identified strategies with the purpose of determining their attractiveness based on their SWOT factors. The results of the study showed that using a combination of strategies to deal with the physical hazards of the abandoned mine excavations was the most attractive approach followed by the grading of the slopes of the excavations to improve their stability, while promoting their safe alternative uses. The no-action option and backfilling of the excavations were the least attractive strategies for dealing with the abandoned surface mine excavations. The study demonstrated how semi-quantitative tools, such as the SWOT analysis and QSPM could assist in finding practical approaches for dealing with the problems of abandoned mine sites or features.
Substrate-Specific Activation of α-Secretase by 7-Deoxy-Trans-Dihydronarciclasine Increases Non-Amyloidogenic Processing of β-Amyloid Protein Precursor
Authors: Chun Yoon Sun , Cho Yoon Young , Kwon Oh Hoon , Zhao Dong , Yang Hyun Ok , Chung Sungkwon
Published: February 2020

Accumulation of β-amyloid (Aβ) in the brain has been implicated in the pathology of Alzheimer’s disease (AD). Aβ is produced from the Aβ precursor protein (APP) through the amyloidogenic pathway by β-, and γ-secretase. Alternatively, APP can be cleaved by α-, and γ-secretase, precluding the production of Aβ. Thus, stimulating α-secretase mediated APP processing is considered a therapeutic option not only for decreasing Aβ production but for increasing neuroprotective sAPPα. We have previously reported that 7-deoxy-trans-dihydronarciclasine (E144), the active component of Lycoris chejuensis, decreases Aβ production by attenuating APP level, and retarding APP maturation. It can also improve cognitive function in the AD model mouse. In this study, we further analyzed the activating effect of E144 on α-secretase. Treatment of E144 increased sAPPα, but decreased β-secretase products from HeLa cells stably transfected with APP. E144 directly activated ADAM10 and ADAM17 in a substrate-specific manner both in cell-based and in cell-free assays. The Lineweaver–Burk plot analysis revealed that E144 enhanced the affinities of A Disintegrin and Metalloproteinases (ADAMs) towards the substrate. Consistent with this result, immunoprecipitation analysis showed that interactions of APP with ADAM10 and ADAM17 were increased by E144. Our results indicate that E144 might be a novel agent for AD treatment as a substrate-specific activator of α-secretase.
Preparation and Characterization of Octenyl Succinate β-Cyclodextrin and Vitamin E Inclusion Complex and Its Application in Emulsion
Authors: Ke Dongmei , Chen Wenxue , Chen Weijun , Yun Yong-Huan , Zhong Qiuping , Su Xiaotang , Chen Haiming
Published: February 2020

Vitamin E (VE) and β-cyclodextrin (β-CD) can form an inclusion complex; however, the inclusion rate is low because of the weak interaction between VE and β-CD. The results of a molecular docking study showed that the oxygen atom in the five-membered ring of octenyl succinic anhydride (OSA) formed a strong hydrogen bond interaction (1.89 Å) with the hydrogen atom in the hydroxyl group of C-6. Therefore, β-CD was modified using OSA to produce octenyl succinic-β-cyclodextrin (OCD). The inclusion complexes were then prepared using OCD with VE. The properties of the inclusion complex were investigated by Fourier-transform infrared spectroscopy (FT-IR), 13C CP/MAS NMR, scanning electron microscopy (SEM), and atomic force microscopy (AFM). The results demonstrated that VE had been embedded into the cavity of OCD. Furthermore, the emulsifying properties (particle size distribution, ζ-potential, and creaming index) of the OCD/VE inclusion-complex-stabilized emulsion were compared with that stabilized by β-CD, OCD, and an OCD/VE physical mixture. The results showed that the introduction of the OS group and VE could improve the physical stability of the emulsion. In addition, the OCD/VE inclusion complex showed the strongest ability to protect the oil in the emulsion from oxidation. OCD/VE inclusion complex was able to improve the physical and oxidative stability of the emulsion, which is of great significance to the food industry.
Synthesis of Combretastatin A-4 and 3′-Aminocombretastatin A-4 derivatives with Aminoacid Containing Pendants and Study of their Interaction with Tubulin and as Downregulators of the VEGF, hTERT and c-Myc Gene Expression
Authors: Agut Raül , Falomir Eva , Murga Juan , Martín-Beltrán Celia , Gil-Edo Raquel , Pla Alberto , Carda Miguel , Marco J. Alberto
Published: February 2020

Natural product combretastatin A-4 (CA-4) and its nitrogenated analogue 3′-aminocombretastatin A-4 (AmCA-4) have shown promising antitumor activities. In this study, a range of CA-4 and AmCA-4 derivatives containing amino acid pendants have been synthesized in order to compare their biological actions with those of their parent compounds. Thus, inhibition of cell proliferation on tumor cell lines HT-29, MCF-7 and A-549, as well as on the nontumor cell line HEK-273; in vitro tubulin polymerization; mitotic cell arrest; action on the microtubule cell network and inhibition of VEGF, hTERT, and c-Myc genes have been evaluated. Some AmCA-4 derivatives bearing L-amino acids exhibited inhibition of cell proliferation at low nanomolar levels exceeding the values shown by AmCA-4. Furthermore, while CA-4 and AmCA-4 derivatives do not show significant effects on the in vitro tubulin polymerization and cell cycle arrest, some selected CA-4 and AmCA-4 derivatives are able to cause total depolymerization of the microtubule network on A-549 cells. The best results were obtained in the inhibition of gene expression, particularly on the VEGF gene, in which some AmCA-4 derivatives greatly exceeded the inhibition values achieved by the parent compound.
Design and Synthesis of a Compound Library Exploiting 5-Methoxyleoligin as Potential Cholesterol Efflux Promoter
Authors: Linder Thomas , Geyrhofer Sophie , Papaplioura Eleni , Wang Limei , Atanasov Atanas G. , Stuppner Hermann , Dirsch Verena M. , Schnürch Michael , Mihovilovic Marko D.
Published: February 2020

5-Methoxyleoligin and leoligin are natural occurring lignans derived from Edelweiss (Leontopodium nivale ssp. alpinum), displaying potent pro-angiogenic and pro-arteriogenic activity. Cholesterol efflux from macrophages is associated with reverse cholesterol transport which inhibits the development of cardiovascular disease. Within this study, we developed a modular and stereoselective total synthesis of 5-methoxyleoligin which can be readily used to prepare a novel compound library of related analogs. The target 5-methoxyleoligin was synthesized exploiting a recently disclosed modular route, which allows also rapid synthesis of analogous compounds. All obtained products were tested towards macrophage cholesterol efflux enhancement and the performance was compared to the parent compound leoligin. It was found that variation on the aryl moiety in 2-position of the furan ring allows optimization of the activity profile, whereas the ester-functionality does not tolerate significant alterations.
Theoretical Studies of Photophysical Properties of D−π−A−π−D-Type Diketopyrrolopyrrole-Based Molecules for Organic Light-Emitting Diodes and Organic Solar Cells
Authors: Jin Ruifa , Zhang Xiaofei , Xiao Wenmin
Published: February 2020

A series of D–π–A diketopyrrolopyrrole(DPP)-based small molecules were designed for organic light-emitting diode(OLEDs) and organic solar cell(OSCs) applications. Applying the PBE0/6-31G(d,p) method, the ground state geometry and relevant electronic properties were investigated. The first excited singlet state geometry and the absorption and fluorescent spectra were simulated at the TD-PBE0/6-31G(d,p) level. The calculated results revealed that the photophysical properties were affected through the introduction of different end groups. Furthermore, the electronic transitions corresponding to absorption and emission exhibited an intramolecular charge transfer feature. Our results suggest that the designed molecules acted not only as luminescent for OLEDs, but also as donor materials in OSCs. Moreover, they can also be used as potential electron transfer materials for OLEDs and OSCs.
A Density-Functional Study of the Conformational Preference of Acetylcholine in the Neutral Hydrolysis
Authors: Fadilla Rizka N. , Rusydi Febdian , Aisyah Nufida D. , Khoirunisa Vera , Dipojono Hermawan K. , Ahmad Faozan , Mudasir Mudasir , Puspitasari Ira
Published: February 2020

Acetylcholine, which is associated with Alzheimer’s disease, is widely known to have conformers. The preference of each conformer to undergo neutral hydrolysis is yet to be considered. In this study, we employed density-functional calculations to build the conformers and investigated their preference in one-step neutral hydrolysis. The results showed the preference in ten possible hydrolysis pathways involving seven acetylcholine conformers (reactant), four transition state structures, and two choline conformers (product). Three out of the seven acetylcholine conformers predicted from the results confirmed experimental findings on the conformers stability. We suggested that two out of ten possible pathways were observed in the experimental results based on agreement in reaction energy. Eventually, this study will emphasize the importance of considering acetylcholine conformers in its hydrolysis study.
New Potent 5α- Reductase and Aromatase Inhibitors Derived from 1,2,3-Triazole Derivative
Authors: El-Naggar Mohamed , Abd El-All Amira S. , El-Naem Shweekar I. A. , Abdalla Mohamed M. , Rashdan Huda R. M.
Published: February 2020

This work describes the utility of pyrazole-4-carbaldehyde 1 as starting material for the synthesis of a novel potent series of 5α-reductase and aromatase inhibitors derived from 1,2,3-triazole derivative. Condensation of 1 with active methylene and different amino pyrazoles produced the respective Schiff bases 2–4, 8 and 9. On the other hand, 1 was reacted with ethyl cyanoacetate and thiourea in one-pot reaction to afford the pyrazolo-6- thioxopyridin-2-[3H]-one (10). Moreover, α–β unsaturated chalcone derivative 11 was prepared via the reaction of compound 1 with P-methoxy acetophenone, which in turn reacted with each of ethyl cyanoacetate, malononitrile, hydrazine hydrate, and thiosemicarbazide to afford the corresponding pyridine and pyrazole derivatives 13, 14, 17, and 20. The structure of newly synthesized compounds was characterized by analytical and spectroscopic data (IR, MS and NMR). All new compounds were evaluated against 5α-reductase and aromatase inhibitors and the results showed that many of these compounds inhibit 5α-reductase and aromatase activity; compound 13 was found to be the highest potency among the tested samples comparing with the reference drugs.
Synthesis and In Vitro Photocytotoxicity of 9-/13-Lipophilic Substituted Berberine Derivatives as Potential Anticancer Agents
Authors: Lin Hong-Jhih , Ho Jinn-Hsuan , Tsai Li-Chen , Yang Fang-Yu , Yang Ling-Ling , Kuo Cheng-Deng , Chen Lih-Geeng , Liu Yi-Wen , Wu Jin-Yi
Published: February 2020

The objective of this study was to synthesize the 9-/13-position substituted berberine derivatives and evaluate their cytotoxic and photocytotoxic effects against three human cancer cell lines. Among all the synthesized compounds, 9-O-dodecyl- (5e), 13-dodecyl- (6e), and 13-O-dodecyl-berberine (7e) exhibited stronger growth inhibition against three human cancer cell lines, (HepG2, HT-29 and BFTC905), in comparison with structurally related berberine (1). These three compounds also showed the photocytotoxicity in human cancer cells in a concentration-dependent and light dose-dependent manner. Through flow cytometry analysis, we found out a lipophilic group at the 9-/13-position of berberine may have facilitated its penetration into test cells and hence enhanced its photocytotoxicity on the human liver cancer cell HepG2. Further, in cell cycle analysis, 5e, 6e, and 7e induced HepG2 cells to arrest at the S phase and caused apoptosis upon irradiation. In addition, photodynamic treatment of berberine derivatives 5e, 6e, and 7e again showed a significant photocytotoxic effects on HepG2 cells, induced remarkable cell apoptosis, greatly increased intracellular ROS level, and the loss of mitochondrial membrane potential. These results over and again confirmed that berberine derivatives 5e, 6e, and 7e greatly enhanced photocytotoxicity. Taken together, the test data led us to conclude that berberine derivatives with a dodecyl group at the 9-/13-position could be great candidates for the anti-liver cancer medicines developments.
Biological Activity of Essential Oils
Authors: Mancianti Francesca , Ebani Valentina Virginia
Published: February 2020

Essential oils (EOs) have for a long time been recognized to possess several different biological activities [...]
Nanocellulose and Polycaprolactone Nanospun Composite Membranes and Their Potential for the Removal of Pollutants from Water
Authors: Palacios Hinestroza Hasbleidy , Urena-Saborio Hilary , Zurita Florentina , Guerrero de León Aida Alejandra , Sundaram Gunasekaran , Sulbarán-Rangel Belkis
Published: February 2020

A composite membrane based on polycaprolactone (PCL) and cellulose nanofibers (CNF) with different compositions was prepared using the electro-spinning method, with the objective of developing organic membranes with good mechanical properties to remove contaminants from water. Water is a resource of primary importance for life and human activities. In this sense, cellulose obtained from agave bagasse and polycaprolactone nanofibers was used to prepare membranes that were tested by filtering tap water. The membranes obtained presented a porosity and structure on a nanometric scale. The water quality variables evaluated after filtration with the PCL/CNF membranes showed 100% turbidity removal, 100% conductivity, and heavy metal removal of the order of 75% to 99% for iron and chromium. CNF comprises biowaste derived from tequila production, and it has added value. Electro-spun CNF and PCL membranes can be applied as a “green” and eco-friendly filtration system for water purification.
Cannabinoids and Terpenes as an Antibacterial and Antibiofouling Promotor for PES Water Filtration Membranes
Authors: Nadir Ismara , Rana Nosheen Fatima , Ahmad Nasir Mahmood , Tanweer Tahreem , Batool Amna , Taimoor Zara , Riaz Sundus , Ali Syed Mohsin
Published: February 2020

Plant phytochemicals have potential decontaminating properties, however, their role in the amelioration of hydrophobic water filtration membranes have not been elucidated yet. In this work, phytochemicals (i.e., cannabinoids (C) and terpenes (T) from C. sativa) were revealed for their antibacterial activity against different Gram-positive and Gram-negative bacteria. As such, a synergistic relationship was observed between the two against all strains. These phytochemicals individually and in combination were used to prepare polyethersulfone (PES) hybrid membranes. Membrane characterizations were carried out using scanning electron microscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy. Moreover, contact angle, water retention, surface roughness, mechanical testing, and X-ray florescence analysis were also carried out. According to results, the CT-PES hybrid membrane exhibited the lowest contact angle (40°), the highest water retention (70%), and smallest average pore size (0.04 µm). The hybrid membrane also exhibited improved water flux with no surface leaching. Quantitative bacterial decline analysis of the CT-PES hybrid membranes confirmed an effective antibacterial performance against Gram-positive and Gram-negative bacteria. The results of this study established cannabinoids and terpenes as an inexpensive solution for PES membrane surface modification. These hybrid membranes can be easily deployed at an industrial scale for water filtration purposes.
Synergetic Improvement of Stability and Conductivity of Hybrid Composites formed by PEDOT:PSS and SnO Nanoparticles
Authors: Vázquez-López Antonio , Yaseen Anisa , Maestre David , Ramírez-Castellanos Julio , Marstein Erik S. , Karazhanov Smagul Zh. , Cremades Ana
Published: February 2020

In this work, layered hybrid composites formed by tin oxide (SnO) nanoparticles synthesized by hydrolysis and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) have been analyzed. Prior to the composite study, both SnO and PEDOT:PSS counterparts were characterized by diverse techniques, such as X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), photoluminescence (PL), atomic force microscopy (AFM), optical absorption and Hall effect measurements. Special attention was given to the study of the stability of the polymer under laser illumination, as well as the analysis of the SnO to SnO2 oxidation assisted by laser irradiation, for which different laser sources and neutral filters were employed. Synergetic effects were observed in the hybrid composite, as the addition of SnO nanoparticles improves the stability and electrical conductivity of the polymer, while the polymeric matrix in which the nanoparticles are embedded hinders formation of SnO2. Finally, the Si passivation behavior of the hybrid composites was studied.
Digital PCR as an Emerging Tool for Monitoring of Microbial Biodegradation
Authors: Cao Yiqi , Yu Miao , Dong Guihua , Chen Bing , Zhang Baiyu
Published: February 2020

Biodegradation of contaminants is extremely complicated due to unpredictable microbial behaviors. Monitoring of microbial biodegradation drives us to determine (1) the amounts of specific degrading microbes, (2) the abundance, and (3) expression level of relevant functional genes. To this endeavor, the cultivation independent polymerase chain reaction (PCR)-based monitoring technique develops from endpoint PCR, real-time quantitative PCR, and then into novel digital PCR. In this review, we introduce these three categories of PCR techniques and summarize the timely applications of digital PCR and its superiorities than qPCR for biodegradation monitoring. Digital PCR technique, emerging as the most accurately absolute quantification method, can serve as the most promising and robust tool for monitoring of microbial biodegradation.
Extraction Optimization, Structural Characterization, and Anticoagulant Activity of Acidic Polysaccharides from Auricularia auricula-judae
Authors: Bian Chun , Wang Zhenyu , Shi John
Published: February 2020

To explore Auricularia auricula-judae polysaccharides (AAP) as natural anticoagulants for application in the functional food industry, ultrasound assisted extraction (UAE) was optimized for the extraction of AAP by using a response surface methodology (RSM). The maximum extraction yield of crude AAP (14.74 mg/g) was obtained at the optimized extraction parameters as follows: Extraction temperature (74 °C), extraction time (27 min), the ratio of liquid to raw material (103 mL/g), and ultrasound power (198 W). Furthermore, the acidic AAP (aAAP) was precipitated with cetyltrimethylammonium bromide (CTAB) from crude AAP (cAAP). aAAP was further purified using ion exchange chromatography with a DEAE Purose 6 Fast Flow column to obtain aAAP-1. Additionally, according to the HPLC analysis, the aAAP-1 was mainly composed of mannose, glucuronic acid, glucose, galactose, and xylose, with a molar ratio of 80.63:9.88:2.25:1:31.13. Moreover, the results of the activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) indicated aAAP-1 had anticoagulant activity, which was a synergic anticoagulant activity by the endogenous and exogenous pathway.
Identification of 1-Butyl-Lysergic Acid Diethylamide (1B-LSD) in Seized Blotter Paper Using an Integrated Workflow of Analytical Techniques and Chemo-Informatics
Authors: Tsochatzis Emmanouil , Lopes Joao Alberto , Reniero Fabiano , Holland Margaret , Åberg Jenny , Guillou Claude
Published: February 2020

The rapid dispersion of new psychoactive substances (NPS) presents challenges to customs services and analytical laboratories, which are involved in their detection and characterization. When the seized material is limited in quantity or of a complex nature, or when the target substance is present in very small amounts, the need to use advanced analytical techniques, efficient workflows and chemo-informatics tools is essential for the complete identification and elucidation of these substances. The current work describes the application of such a workflow in the analysis of a single blotter paper, seized by Swedish customs, that led to the identification of a lysergic acid diethylamide (LSD) derivative, 1-butyl-lysergic acid diethylamide (1B-LSD). Such blotter paper generally contains an amount in the range of 30–100 ug. This substance, which is closely related to 1-propionyl-lysergic acid diethylamide (1P-LSD), seems to have only recently reached the drug street market. Its identification was made possible by comprehensively combining gas chromatography with mass spectrometry detection (GC–MS), liquid chromatography coupled with high-resolution tandem MS (LC–HR-MS/MS), Orbitrap-MS and both 1D and 2D nuclear-magnetic-resonance (NMR) spectroscopy. All the obtained data have been managed, assessed, processed and evaluated using a chemo-informatics platform to produce the effective chemical and structural identification of 1B-LSD in the seized material.