bluuebunny/crossref_metadata_2025 huggingface dataset:
The Chiaravalle Cross: Results of a Multidisciplinary Study
Authors: Di Martino Daniela , Benati Giulia , Alberti Roberto , Baroni Sandro , Bertelli Carlo , Blumer Franco , Caselli Letizia , Cattaneo Roberta , Cucini Costanza , D’Amico Fabio , Frizzi Tommaso , Gagetti Elisabetta , Gironda Michele , Greggio Lisa , Lazzarini Lorenzo , Musa Maya , Perelli Cippo Enrico , Riccardi Maria Pia , Gorini Giuseppe
Published: August 2019

The Chiaravalle Cross, a masterpiece of Mediaeval goldsmithery, went under restoration in 2016. This was a unique opportunity to undertake an in-depth multidisciplinary study. Several issues were addressed, as for example the chronology of the Cross, lacking any official document about it. The scientific investigations included in situ and laboratory measurements, and the analyses, part of a multidisciplinary protocol, completely characterized the gemstones adorning the Cross, the cameos, the gold, silver, jasper and glass parts, to derive indications on their provenance, authenticity and dating issues. All the results were shared with the whole collaboration of experts, which included art historians, a restorer, a conservator, a scholar in ancient glyptic, gemologists, archaeometallurgists, physicists and scientists in a very fruitful exchange of knowledge. This work is an example of a real multidisciplinary research, gathering good practices in the study of a complex piece of art.
Climatic Conditions: Conventional and Nanotechnology-Based Methods for the Control of Mosquito Vectors Causing Human Health Issues
Authors: Ahmed Toqeer , Hyder Muhammad Zeeshan , Liaqat Irfan , Scholz Miklas
Published: August 2019

Climate variability is highly impacting on mosquito-borne diseases causing malaria and dengue fever across the globe. Seasonal variability change in temperature and rainfall patterns are impacting on human health. Mosquitoes cause diseases like dengue fever, yellow fever, malaria, Chikungunya, West Nile and Japanese encephalitis. According to estimations by health organizations, annually one million human deaths are caused by vector-borne diseases, and dengue fever has increased about 30-fold over the past 50 years. Similarly, over 200 million cases of malaria are being reported annually. Mosquito-borne diseases are sensitive to temperature, humidity and seasonal variability. Both conventional (environmental, chemical, mechanical, biological etc.) and nanotechnology-based (Liposomes, nano-suspensions and polymer-based nanoparticles) approaches are used for the eradication of Malaria and dengue fever. Now green approaches are used to eradicate mosquitoes to save human health without harming the environment. In this review, the impact of climatic conditions on mosquito-borne diseases along with conventional and nanotechnology-based approaches used for controlling malaria and dengue fever have been discussed. Important recommendations have been made for people to stay healthy.
New Patterns of Information and Communication Technologies Usage at Work and Their Relationships with Visual Discomfort and Musculoskeletal Diseases: Results of a Cross-Sectional Study of Spanish Organizations
Authors: Soria-Oliver María , López Jorge , Torrano Fermín , García-González Guillermo , Lara Ángel
Published: August 2019

This cross-sectional study analyses the usage patterns of the new communication and information technologies (ICTs) and their relationship with visual discomfort and musculoskeletal diseases in an intentional sample of 1259 workers of Spanish organizations. The usage pattern with the greatest incidence of visual and muscular-skeletal disorders, especially in the wrist and neck, combines the use of laptops and desktops during long working hours. However, the group of workers primarily using mobile devices and working mostly at mobile posts does not appear to be particularly vulnerable to the musculoskeletal diseases and visual fatigue. The ratio of taking a short pause per hour and the implantation of certain technical and preventive measures is related to lower incidence of disorders in the workers as a whole. Current usage of ICTs is very complex and should be addressed using empirical analysis of the different forms of usage and their impacts on health.
Co-Creating Recommendations to Redesign and Promote Strength and Balance Service Provision
Authors: Leask Calum F , Colledge Nick , Laventure Robert M E , McCann Deborah A , Skelton Dawn A
Published: August 2019

Background: Awareness of physical activity guidelines are low, particularly the “forgotten guidelines” of strength and balance. Increasing awareness of guidelines, but also of appropriate local services that can be utilised, is an important step towards active ageing. Co-creation can inform tailored service provision to potentially increase uptake and adherence. The aim was to co-create recommendations to redesign and promote local leisure services, emphasising strength and balance activity provision. Method: Twenty-four ageing and older adults engaged in 10 co-creation workshops. Workshops consisted of interactive tasks, and fieldwork tasks were undertaken externally. Data were collected using field notes, worksheet tasks and facilitator reflections and were analysed using qualitative content analysis. Results: Retention and adherence rates were 92% and 85%. Co-creators cited group cohesion, scientific input from experts and perceived knowledge development as enjoyable elements of the process. Four key themes emerged from analysis: (1) localised strategies for awareness raising, (2) recruitment of volunteer champions to increase uptake and maintenance, (3) accessibility of activities, including what they are and when they are, and (4) evaluation of impact. Conclusion: This has been the first study, to our knowledge, to utilise co-creation for informed leisure service provision improvement. Future work should aim to implement these recommendations to ascertain what impact these themes might make.
Structural Insights into the Interaction of Cytochrome P450 3A4 with Suicide Substrates: Mibefradil, Azamulin and 6′,7′-Dihydroxybergamottin
Authors: Sevrioukova Irina F.
Published: August 2019

Human cytochrome P450 3A4 (CYP3A4) is the most important drug-metabolizing enzyme. Some drugs and natural compounds can act as suicide (mechanism-based) inactivators of CYP3A4, leading to unanticipated drug-drug interactions, toxicity and therapeutic failures. Despite significant clinical and toxicological implications, the mechanism-based inactivation remains incompletely understood. This study provides the first direct insights into the interaction of CYP3A4 with three suicide substrates: mibefradil, an antihypertensive drug quickly withdrawn from the market; a semi-synthetic antibiotic azamulin; and a natural furanocoumarin, 6′,7′-dihydroxybergamottin. Novel structural findings help better understand the suicide substrate binding and inhibitory mechanism, and can be used to improve the predictability of the binding ability, metabolic sites and inhibitory/inactivation potential of newly developed drugs and other chemicals relevant to public health.
Terminology Translation in Low-Resource Scenarios
Authors: Haque Rejwanul , Hasanuzzaman Mohammed , Way Andy
Published: August 2019

Term translation quality in machine translation (MT), which is usually measured by domain experts, is a time-consuming and expensive task. In fact, this is unimaginable in an industrial setting where customised MT systems often need to be updated for many reasons (e.g., availability of new training data, leading MT techniques). To the best of our knowledge, as of yet, there is no publicly-available solution to evaluate terminology translation in MT automatically. Hence, there is a genuine need to have a faster and less-expensive solution to this problem, which could help end-users to identify term translation problems in MT instantly. This study presents a faster and less expensive strategy for evaluating terminology translation in MT. High correlations of our evaluation results with human judgements demonstrate the effectiveness of the proposed solution. The paper also introduces a classification framework, TermCat, that can automatically classify term translation-related errors and expose specific problems in relation to terminology translation in MT. We carried out our experiments with a low resource language pair, English–Hindi, and found that our classifier, whose accuracy varies across the translation directions, error classes, the morphological nature of the languages, and MT models, generally performs competently in the terminology translation classification task.
Exploring the Influence of Social Media Information on Interpersonal Trust in New Virtual Work Partners
Authors: Martinelli Watanuki Hugo , de Oliveira Moraes Renato
Published: August 2019

This short communication proposes an exploratory investigation regarding the impact of social media information on interpersonal trust in new virtual work partners. The suggested approach assesses this potential impact via a combination of theories from informational economic studies and virtual team research. An initial theoretical model is also proposed.
Interventional Radiology Suite: A Primer for Trainees
Authors: Taslakian Bedros , Ingber Ross , Aaltonen Eric , Horn Jeremy , Hickey Ryan
Published: August 2019

Familiarity with different instruments and understanding the basics of image guidance techniques are essential for interventional radiology trainees. However, there are no structured references in the literature, and trainees are left to “pick it up as they go”. Puncture needles, guidewires, sheath systems, and catheters represent some of the most commonly used daily instruments by interventional radiologists. There is a large variety of instruments, and understanding the properties of each tool will allow trainees to better assess which type is needed for each specific procedure. Along with understanding the tools required to perform various interventional radiology procedures, it is important for trainees to learn how to organize the room, procedural table, and various equipment that is used during the procedure. Minimizing clutter and improving organization leads to improved efficiency and decreased errors. In addition, having a fundamental knowledge of fluoroscopy, the most commonly used imaging modality, is an integral part of beginning training in interventional radiology.
Effect of Ceramic and Nylon Fiber Content on Composite Silica Sol Slurry Properties and Bending Strength of Investment Casting Shell
Authors: Huang Pengpeng , Lu Gang , Yan Qingsong , Mao Pu
Published: August 2019

In order to improve the performance of the investment casting shell, ceramic and nylon fiber was added to the silica sol slurry to study the effect of ceramic and nylon fiber on the liquidity of the silica sol slurry and the bending strength of the investment casting shell. Meanwhile, the fracture surface of shell sample was observed by SEM. The experiment results indicate that the movement viscosity of slurry increases with ceramic and nylon fiber content, increasing from 0 to 0.75 wt.%. The movement viscosity of ceramic fiber composite slurry is higher than nylon fiber composite slurry. The wet and high strength of shell firstly increases then decreases, with an increase of ceramic and nylon fiber content. When the ceramic and nylon fibers’ contents are 0.6 wt.%, the maximum wet strengths are 3.56 MPa and 3.84 Mpa respectively, increasing by approximately 38% and 43%. Moreover, the high strength of shell achieves its highest value, 5.08 Mpa, when the ceramic fiber content is 0.6 wt.%; however, when the nylon fiber content was more than 0.3%, the high strength of the nylon fiber reinforced shell was decreased sharply. Therefore, an addition of ceramic and nylon fiber to silica sol slurry distinctly influences the wet and high strength of investment casting shell.
Modified Fourier–Galerkin Solution for Aerospace Skin-Stiffener Panels Subjected to Interface Force and Mixed Boundary Conditions
Authors: Hou Renluan , Wang Qing , Li Jiangxiong , Ke Yinglin
Published: August 2019

Aeronautical stiffened panels composed of thin shells and beams are prone to deformation or buckling due to the combined loading, functional boundary conditions and interface forces between joined parts in the assembly processes. In this paper, a mechanical prediction model of the multi-component panel is presented to investigate the deformation propagation, which has a significant effect on the fatigue life of built-up structures. Governing equations of Kirchhoff–Love shell are established, of which displacement expressions are transformed into Fourier series expansions of several introduced potential functions by applying the Galerkin approach. This paper presents an intermediate quantity, concentrated force at the joining interface, to describe mechanical interactions between the coupled components. Based on the Euler–Bernoulli beam theory, unknown intermediate quantity is calculated by solving a 3D stringer deformation equation with static boundary conditions specified on joining points. Compared with the finite element simulation and integrated model, the proposed method can substantially reduce grid number without jeopardizing the prediction accuracy. Practical experiment of the aircraft panel assembly is also performed to obtain the measured data. Maximum deviation between the experimental and predicted clearance values is 0.193 mm, which is enough to meet the requirement for predicting dimensional variations of the aircraft panel assembly.
The Impact of Shear and Elongational Forces on Structural Formation of Polyacrylonitrile/Carbon Nanotubes Composite Fibers during Wet Spinning Process
Authors: Mirbaha Hamideh , Nourpanah Parviz , Scardi Paolo , D’incau Mirco , Greco Gabriele , Valentini Luca , Bittolo Bon Silvia , Arbab Shahram , Pugno Nicola
Published: August 2019

Wet spinning of polyacrylonitrile/carbon nanotubes (PAN/CNT) composite fibers was studied and the effect of spinning conditions on structure and properties of as-spun fibers influenced by the presence of CNTs investigated. Unlike PAN fibers, shear force had a larger effect on crystalline structure and physical and mechanical properties of PAN/CNT composite fibers compared to the elongational force inside a coagulation bath. Under shear force CNTs induced nucleation of new crystals, whereas under elongational force nucleation of new crystals were hindered but the already formed crystals grew bigger. To our knowledge, this key effect has not been reported elsewhere. At different shear rates, strength, Young’s modulus and strain at break of PAN/CNT as-spun fibers were improved up to 20% compared to PAN fibers. Application of jet stretch had less influence on physical and mechanical properties of PAN/CNT fibers compared to PAN fibers. However, the improvement of interphase between polymer chains and CNTs as a result of chain orientation may have contributed to enhancement of Young’s modulus of jet stretched composite fibers.
Effect of Freeze-Thaw Cycles on Triaxial Strength Property Damage to Cement Improved Aeolian Sand (CIAS)
Authors: Li Jun , Wang Fengchi , Yi Fu , Wu Fengyuan , Liu Jiashun , Lin Zhenhuan
Published: August 2019

Natural aeolian sand has the characteristics of low cohesion and poor water stability. In order to improve its crack resistance properties in the process of freeze-thaw cycles, P.O 42.5 ordinary Portland cement was added to form a mixture called cement improved aeolian sand (CIAS). SEM was used to analyze the microscopic micro-structure of CIAS at different times (7 days and 28 days). The mechanical properties of CIAS samples affected by freeze-thaw cycles were tested in a triaxial instrument, and gray-scale images of the three-phase distribution in the CIAS after freeze-thaw cycling were obtained by computed tomography (CT) scanning technology. The pore characteristic parameters (pore area, fractal dimension, and crack length) were studied by digital image process technique. Based on classical Griffith fracture theory, the development of the crack length and crack width with increasing freeze-thaw cycles is determined. Assuming that the pore area subordinates to the Weibull distribution, the parameters of the Weibull distribution, the damage evolution defined by the elastic modulus attenuation, and the pore area development of CIAS were determined. Research shows the cohesion decreases and internal friction angle increases with increasing cycle numbers. Three development patterns are observed: crack growth, crack closure, and crack merging, and the three patterns interact during freeze-thaw cycling. Furthermore, the fractal dimension of the pore edge fluctuates with the increasing number of freeze-thaw cycles. This work provides a theoretical basis for the application of aeolian sand and develops a method for disaster prevention in applications of freeze-thaw cycling.
Electrochemical Synthesis of Ammonia: Recent Efforts and Future Outlook
Authors: Garagounis Ioannis , Vourros Anastasios , Stoukides Demetrios , Dasopoulos Dionisios , Stoukides Michael
Published: August 2019

Ammonia is a key chemical produced in huge quantities worldwide. Its primary industrial production is via the Haber-Bosch method; a process requiring high temperatures and pressures, and consuming large amounts of energy. In the past two decades, several alternatives to the existing process have been proposed, including the electrochemical synthesis. The present paper reviews literature concerning this approach and the experimental research carried out in aqueous, molten salt, or solid electrolyte cells, over the past three years. The electrochemical systems are grouped, described, and discussed according to the operating temperature, which is determined by the electrolyte used, and their performance is valuated. The problems which need to be addressed further in order to scale-up the electrochemical synthesis of ammonia to the industrial level are examined.
Effect of Parameters Change on the Weld Appearance in Stainless Steel Underwater Wet Welding with Flux-Cored Wire
Authors: Guo Ning , Zhang Xin , Xu Changsheng , Chen Hao , Fu Yunlong , Cheng Qi
Published: August 2019

The underwater wet welding (UWW) technology is rapidly developing as a crucial method in the maintenance work of marine equipment and offshore platform. The rapid development of UWW technology has also exposed the problems to be solved urgently. Therefore, the influence of welding parameters on the weld appearance and welding spatters was investigated in this paper. The main welding parameters used in the study are welding current, arc voltage, welding speed and the contact tip-to-work distance (CTWD). Through the orthogonal test, it is found that, as each welding parameter increases within a certain range, the amounts of welding spatter decreases first and then increases, and the weld forming effect first becomes better and then deteriorates. The amount of wet welding spatter is mainly affected by the welding speed. When the welding speed is low, the splash is more, and the change of the welding current and the arc voltage has a little effect on the number of spatters. When the welding speed is large, the spatter is most with a small welding current and a large arc voltage. After evaluating the weld morphology obtained by welding under various parameters, a set of optimal parameters was obtained. The best parameters for the underwater wet welding of stainless steel with self-shielded flux-cored wire are determined to be 200 A-29 V-2.0 mm/s-15 mm (CTWD).
Tin Dioxide Thin Film with UV-enhanced Acetone Detection in Microwave Frequency Range
Authors: Rydosz Artur , Staszek Kamil , Brudnik Andrzej , Gruszczynski Slawomir
Published: August 2019

In this paper, the UV illumination effect for microwave gas sensors based on the tin dioxide was verified. A UV LED with emission wavelength close to the absorption edge of the SnO2 gas-sensing layer was selected as the UV source. The developed gas sensors were tested under exposure to acetone in the 0–200 ppm range at room temperature. The sensor’s complex reflection coefficient corresponding to target gas concentration was measured with the use of a five-port reflectometer system exhibiting enhanced uncertainty distribution, which allows for the detection of low gas concentration. The UV illumination significantly emphasizes the sensors’ response in terms of both magnitude and phase for low gas concentrations, in contrast to previously reported results, in which only the reflection coefficient’s phase was affected. The highest responses were obtained for modulated UV illumination.
Micro–Macro: Selective Integration of Microfeatures Inside Low-Cost Macromolds for PDMS Microfluidics Fabrication
Authors: Jiménez-Díaz Edgar , Cano-Jorge Mariel , Zamarrón-Hernández Diego , Cabriales Lucia , Páez-Larios Francisco , Cruz-Ramírez Aarón , Vázquez-Victorio Genaro , Fiordelisio Tatiana , Hautefeuille Mathieu
Published: August 2019

Microfluidics has become a very promising technology in recent years, due to its great potential to revolutionize life-science solutions. Generic microfabrication processes have been progressively made available to academic laboratories thanks to cost-effective soft-lithography techniques and enabled important progress in applications like lab-on-chip platforms using rapid- prototyping. However, micron-sized features are required in most designs, especially in biomimetic cell culture platforms, imposing elevated costs of production associated with lithography and limiting the use of such devices. In most cases, however, only a small portion of the structures require high-resolution and cost may be decreased. In this work, we present a replica-molding method separating the fabrication steps of low (macro) and high (micro) resolutions and then merging the two scales in a single chip. The method consists of fabricating the largest possible area in inexpensive macromolds using simple techniques such as plastics micromilling, laser microfabrication, or even by shrinking printed polystyrene sheets. The microfeatures were made on a separated mold or onto existing macromolds using photolithography or 2-photon lithography. By limiting the expensive area to the essential, the time and cost of fabrication can be reduced. Polydimethylsiloxane (PDMS) microfluidic chips were successfully fabricated from the constructed molds and tested to validate our micro–macro method.
Parametric Characteristics and Bifurcation Analysis of Multi-Degree-of-Freedom Micro Gyroscope with Drive Stiffness Nonlinearity
Authors: Han Mingjiang , Zhang Qichang , Hao Shuying , Li Weixiong
Published: August 2019

The dynamic equations of a four-degree-of-freedom micro gyroscope system were developed considering the nonlinearity of driving stiffness, the primary resonance, and the 1:1 internal resonance. Then, the perturbation analysis was carried out using the method of multiple scales. The influence of stiffness nonlinearity and system parameters on micro-gyro dynamic characteristics, output sensitivity, detection bandwidth, and working stability were discussed based on the analytic and numerical solutions of the dynamic equations. Through the singularity theory, the influence of system parameters on bifurcation behavior was analyzed. The results show that the amplitude jump and multi-stable solutions caused by the nonlinear hardening characteristics of the high robust two-degree-of-freedom drive-mode occur outside the detection bandwidth. In addition, the influence on the bandwidth was weak and the sensitivity of the bandwidth area was slightly reduced. Moreover, saturation existed in the response amplitude of the second drive-mode in spite of the primary resonance being completely tuned or detuned. As a result, although the electrostatic force amplitude was out of the unstable region and even took a larger value, the micro gyroscope obtained a larger stable output. Besides, nonlinearity will lead to energy transfer between various modes of multi-degree-of-freedom micro gyroscopes. That means the response amplitudes could change greatly due to the variation of the external environment even the system is under a constant excitation frequency. Therefore, increasing the stiffness coefficient of the micro beam and the electrostatic force amplitude can maintain the robustness of the system to environmental changes and avoid the occurrence of bifurcation.
Flexible Tactile Sensor Array for Slippage and Grooved Surface Recognition in Sliding Movement
Authors: Wang Yancheng , Chen Jianing , Mei Deqing
Published: August 2019

Flexible tactile sensor with contact force sensing and surface texture recognition abilities is crucial for robotic dexterous grasping and manipulation in daily usage. Different from force sensing, surface texture discrimination is more challenging in the development of tactile sensors because of limited discriminative information. This paper presents a novel method using the finite element modeling (FEM) and phase delay algorithm to investigate the flexible tactile sensor array for slippage and grooved surfaces discrimination when sliding over an object. For FEM modeling, a 3 × 3 tactile sensor array with a multi-layer structure is utilized. For sensor array sliding over a plate surface, the initial slippage occurrence can be identified by sudden changes in normal forces based on wavelet transform analysis. For the sensor array sliding over pre-defined grooved surfaces, an algorithm based on phase delay between different sensing units is established and then utilized to discriminate between periodic roughness and the inclined angle of the grooved surfaces. Results show that the proposed tactile sensor array and surface texture recognition method is anticipated to be useful in applications involving human-robotic interactions.
Hydrochemistry, Distribution and Formation of Lithium-Rich Brines in Salt Lakes on the Qinghai-Tibetan Plateau
Authors: Li Qingkuan , Fan Qishun , Wang Jianping , Qin Zhanjie , Zhang Xiangru , Wei Haicheng , Du Yongsheng , Shan Fashou
Published: August 2019

Salt lakes on the Qinghai-Tibetan Plateau (QTP) are remarkable for Li-rich brines. Along with the surging demand of Li, the Li-rich brines in salt lakes on the QTP are of great importance for China’s Li supply. Previous studies reported the geological, geographical, geochemical signatures of numerous salt lakes on the QTP; however, conclusive work and the internal relationships among the hydrochemistry, distribution and geological setting of Li-rich salt lakes are still inadequate. In this study, major and trace (Li, B) ionic compositions of 74 Li-rich salt lakes on the QTP were reviewed. The Li-rich brines cover various hydrochemical types (carbonate, sodium sulfate, magnesium sulfate, and chloride types) and present horizontal zoning from the southwest to the northeast along with the stronger aridity. The Li concentrations and Mg/Li ratios in these salt lakes range from 23 to 2895 mg/L, 0.0 to 1549.4, respectively. The distribution of these salt lakes is close to the major suture zones. Geothermal water is proposed to be the dominant source of Li in the investigated salt lakes, while weathering of Li-bearing sediments and igneous rocks, and brine migration provide a minor part of Li. Four factors (sufficient Li sources, arid climate, endorheic basin and time) should be considered for the formation of Li-rich brines in salt lakes on the QTP.
Treatment with Docosahexaenoic Acid Improves Epidermal Keratinocyte Differentiation and Ameliorates Inflammation in Human Keratinocytes and Reconstructed Human Epidermis Models
Authors: Jia Tinghan , Qiao Wu , Yao Qifeng , Wu Wenhui , Kaku Ken
Published: August 2019

Atopic dermatitis (AD) is a chronic inflammatory skin disease that can cause skin barrier function damage. Although co-incubation with docosahexaenoic acid (DHA) exerts a positive effect on deficient skin models, no studies have investigated the effects of topical treatment with DHA in an inflammatory reconstructed human epidermis (RHE) model. The effects of DHA on monolayer normal human epidermal keratinocyte (NHEK) cells were evaluated using cell counting kit-8 (CCK-8), real-time quantitative polymerase chain reaction (qPCR), and enzyme-linked immunosorbent assay (ELISA). The skin-related barrier function was assessed using hematoxylin–eosin (HE) staining, Western blot (WB), immunohistofluorescence (IF), and ELISA in normal and inflammatory RHE models. Docosahexaenoic acid upregulated filaggrin and loricrin expression at mRNA levels in addition to suppressing overexpression of tumor necrosis factor-α (TNF-α), interleukin-α (IL-1α), and interleukin-6 (IL-6) stimulated by polyinosinic–polycytidylic acid (poly I:C) plus lipopolysaccharide (LPS) (stimulation cocktail) in cultured NHEK cells. After topical treatment with DHA, cocktail-induced inflammatory characteristics of skin diseases, including barrier morphology, differentiation proteins, and thymic stromal lymphopoietin (TSLP) secretion, were alleviated in RHE models. Supplementation with DHA can improve related barrier function and have anti-inflammation effects in monolayer keratinocytes and RHE models, which indicates that DHA may have potential value for the treatment of inflammation-associated skin diseases.
Bioactive Constituents from the Roots of Eurycoma longifolia
Authors: Ruan Jingya , Li Zheng , Zhang Ying , Chen Yue , Liu Mengyang , Han Lifeng , Zhang Yi , Wang Tao
Published: August 2019

Four new phenolic components, eurylophenolosides A (1) and B (2), eurylolignanosides A (3) and B (4), along with twelve known compounds were isolated from the roots of Eurycoma longifolia Jack. The structure of these components was elucidated by using various spectral techniques and chemical reactions. Among the known isolates, syringaldehyde (12), 3-chloro-4-hydroxybenzoic acid (13), 3-chloro-4-hydroxyl benzoic acid-4-O-β-d-glucopyranoside (14), and isotachioside (15) were isolated from the Eurycoma genus for the first time. Further, the NMR data of 14 was reported here firstly. Meanwhile, the nitric oxide (NO) inhibitory activities of all compounds were examined in lipopolysaccharide (LPS)-stimulated RAW264.7 cells at 40 μM. As results, piscidinol A (6), 24-epi-piscidinol A (7), bourjotinolone A (10), and scopoletin (16) were found to play important role in suppressing NO levels without cytotoxicity. Furthermore, the Western blot method was used to investigate the mechanism of compounds 6, 7, 10, and 16 by analysing the level of inflammation related proteins, such as inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in LPS-stimulated RAW264.7 cells. Consequently, compounds 6, 7, 10, and 16 were found to significantly inhibit LPS-induced protein expression of IL-6, NF-κB and iNOS in NF-κB signaling pathway. Moreover, it was found that the protein expression inhibitory effects of 6, 7, and 16 exhibited in a dose-dependent manner. The mechanism may be related to the inhibition of the iNOS expressions through suppressing the IL-6-induced NF-κB pathway.
Characterization and Hemostatic Potential of Two Kaolins from Southern China
Authors: Gan Changjiao , Hu Hongjie , Meng Zhiyun , Zhu Xiaoxia , Gu Ruolan , Wu Zhuona , Wang Hongliang , Wang Donggen , Gan Hui , Wang Jinglin , Dou Guifang
Published: August 2019

The physicochemical properties and potential hemostatic application of Wenchang kaolin and Maoming kaolin were inspected and evaluated. Chemical composition analysis, Fourier transform infrared (FTIR) spectroscopy, surface area determination, X-ray diffraction, particle size, scanning electron microscopy (SEM) observations, and zeta potential analysis were performed to quantify the physical and chemical properties of the two kaolins. The results showed that both kaolins have typical FTIR bands of kaolinite with a weight fraction for kaolinite over 90 wt%. Larger conglobate aggregates of Maoming kaolin demonstrated wider particle size distributions with two peaks at 3.17 and 35.57 μm, while the book-like Wenchang kaolin had narrow particle size distribution, with a frequent size of 5.64 μm. Furthermore, thrombelastography, the whole blood clotting tests (WBCT), plasma recalcification time (PRT) measurement, and MTT assay were performed to measure the clotting activities and biocompatibility of the two kaolins. The results showed that both kaolins could promote blood coagulation with good cytocompatibility, while Wenchang kaolin had a better procoagulant activity than Maoming kaolin. These findings demonstrated Wenchang kaolin to be a more suitable local source material for application as a hemostatic agent.
Involvement of CB2 Receptors in the Neurobehavioral Effects of Catha Edulis (Vahl) Endl. (Khat) in Mice
Authors: Geresu Berhanu , Canseco-Alba Ana , Sanabria Branden , Lin Zhicheng , Liu Qing-Rong , Onaivi Emmanuel S. , Engidawork Ephrem
Published: August 2019

There is behavioral evidence for the interaction between crude khat extract and the endocannabinoid system, whereby the endocannabinoid system alters khat extract-mediated behavioral effects through modulation of the monoaminergic system. The objective of this study was to investigate the role of the endocannabinoid system on the neurobehavioral effect of khat extract in mice following concomitant administration of khat extract and the CB2R agonist, JWH133. Locomotor activity test, immunohistochemistry, and reverse transcriptase polymerase chain reaction technique were utilized to assess locomotor activity, tyrosine hydroxylase immunoreactivity, and expression of dopamine transporter mRNA gene. The results show sub-acute administration of khat extract alone increased locomotor activity in mice and co-administration of the CB2R agonist, JWH133, reduced khat extract induced hyperlocomotor activity. The data revealed that cell type specific deletion of CB2Rs on dopaminergic neurons increased the hyperlocomotor behavior of khat extract. Furthermore, the results revealed that khat extract attenuated MPTP induced motor deficits, which is enhanced by JWH133. Khat extract also increased expression of tyrosine hydroxylase positive cells and expression of dopamine transporter mRNA gene in wild type mice. Nevertheless, JWH133 did not alter the effect of khat extract on tyrosine hydroxylase immunoreactivity and dopamine transporter mRNA expression when given together with khat extract. Taken together, the results suggest that the CB2Rs selectively interact with khat extract-mediated locomotor effects and could be utilized as therapeutic target in central nervous system movement disorders associated with dopamine dysregulation.
Sesquiterpene Lactones and Flavonoids from Psephellus pyrrhoblepharus with Antiproliferative Activity on Human Gynecological Cancer Cell Lines
Authors: Tastan Pelin , Hajdú Zsuzsanna , Kúsz Norbert , Zupkó István , Sinka Izabella , Kivcak Bijen , Hohmann Judit
Published: August 2019

Multistep chromatographic separations of the chloroform extract of the Turkish endemic plant Psephellus pyrrhoblepharus (Boiss.) Wagenitz (syn. Centaurea pyrrhoblephara Boiss.) resulted in the isolation of six guaianolid-type sesquiterpenes, chlorojanerin (1), 19-deoxychlorojanerin (2), 15-hydroxyjanerin (3), aguerin B (4), cynaropicrin (5), eleganin (6); three flavonoids, apigenin, 6-methoxyluteolin and jaceosidine; two glycosides, benzyl-1-O-β-d-glucoside and 3(Z)-hexenyl-1-O-β-d-glucoside; and the coumarin scopoletin. The structures were established by the interpretation of their ESI-MS and 1D and 2D NMR data including 1H-NMR, JMOD, 1H,1H-COSY, HSQC, HMBC, and NOESY experiments. All compounds were isolated for the first time from P. pyrrhoblepharus. Compounds 1–6, the isolated flavonoids and scopoletin were evaluated for their antiproliferative activities on human gynecological cancer cell lines (SiHa, HeLa, and MDA-MB-231 cells) using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Chlorojanerin (1), 19-deoxychlorojanerin (2), aguerin B (4), cynaropicrin (5), eleganin (6) were shown to have noteworthy effects on all of the tested cell lines, while apigenin, jaceosidine, and 6-methoxyluteolin were moderately active on HeLa cells. The highest activities were demonstrated by the chlorine-containing derivatives chlorojanerin (1) and 19-deoxychlorojanerin (2) with IC50 values of 2.21 and 2.88 µM, respectively, against the triple negative breast cancer model MDA-MB-231 cells.
Alkali Hydrolysis of Sulfated Cellulose Nanocrystals: Optimization of Reaction Conditions and Tailored Surface Charge
Authors: Jordan Jacobs H. , Easson Michael W. , Condon Brian D.
Published: August 2019

Cellulose nanocrystals (CNCs) are a biorenewable resource, which may be chemically modified to impart specific properties. Modified CNCs have found use in imaging applications, as rheology modifiers, polymer reinforcements, barrier and/or optical films, and nanocomposites. Nanoparticle dimensions of CNCs are typically 5–10 nm in width, with lengths of <100–300 nm. However, the physical properties are dependent upon the number and nature of the surface charge groups imparted during preparation. In the case of CNCs produced from sulfuric acid hydrolysis, the sulfated surface groups may be partially removed prior to further functionalization. This gives more available hydroxyls yet renders the CNCs less colloidally stable. Furthermore, conditions vary significantly and there is no consensus about the optimal conditions for partial removal of sulfate functionality or conditions developed to give specific surface charge. In the following, alkali hydrolysis of sulfate half-esters was quantified by conductometric titration of the strong acid groups, and using a design of experiments (DOE), optimal conditions were determined to produce CNCs with tailored surface charge.
Lightning-Rod Effect of Plasmonic Field Enhancement on Hydrogen-Absorbing Transition Metals
Authors: Fukuoka Norihiko , Tanabe Katsuaki
Published: August 2019

The plasmonic enhancement of electromagnetic field energy density at the sharp tips of nanoparticles or nanoscale surface roughnesses of hydrogen-absorbing transition metals, Pd, Ti, and Ni, is quantitatively investigated. A large degree of energy focusing is observed for these transition metals in the microwave region, even surpassing the enhancement for noble metals according to the conditions. Pd, for instance, exhibits peak field enhancement factors of 6000 and 2 × 108 in air for morphological aspect ratios of 10 and 100, respectively. Metal surfaces possibly contain such degrees of nano- or micro-scale native random roughnesses, and, therefore, the field enhancement effect may have been unknowingly produced in existing electrical and optical systems. In addition, for future devices under development, particularly in hydrogen-related applications, it is desirable to design and optimize the systems, including the choice of materials, structures, and operating conditions, by accounting for the plasmonic local energy enhancement effect around the metal surfaces.
SERS Sensing Properties of New Graphene/Gold Nanocomposite
Authors: Neri Giulia , Fazio Enza , Mineo Placido Giuseppe , Scala Angela , Piperno Anna
Published: August 2019

The development of graphene (G) substrates without damage on the sp2 network allows to tune the interactions with plasmonic noble metal surfaces to finally enhance surface enhanced Raman spectroscopy (SERS) effect. Here, we describe a new graphene/gold nanocomposite obtained by loading gold nanoparticles (Au NPs), produced by pulsed laser ablation in liquids (PLAL), on a new nitrogen-doped graphene platform (G-NH2). The graphene platform was synthesized by direct delamination and chemical functionalization of graphite flakes with 4-methyl-2-p-nitrophenyl oxazolone, followed by reduction of p-nitrophenyl groups. Finally, the G-NH2/Au SERS platform was prepared by using the conventional aerography spraying technique. SERS properties of G-NH2/Au were tested using Rhodamine 6G (Rh6G) and Dopamine (DA) as molecular probes. Raman features of Rh6G and DA are still detectable for concentration values down to 1 × 10−5 M and 1 × 10−6 M respectively.
Influence of Femtosecond Laser Surface Nanotexturing on the Friction Behavior of Silicon Sliding Against PTFE
Authors: Alves-Lopes Isabel , Almeida Amélia , Oliveira Vítor , Vilar Rui
Published: August 2019

The aim of the present work was to investigate the influence of laser-induced periodic surface structures (LIPSS) produced by femtosecond laser on the friction behavior of silicon sliding on polytetrafluoroethylene (PTFE) in unlubricated conditions. Tribological tests were performed on polished and textured samples in air using a ball-on-flat nanotribometer, in order to evaluate the friction coefficient of polished and textured silicon samples, parallel and perpendicularly to the LIPSS orientation. In the polished specimens, the friction coefficient decreases with testing time at 5 mN, while it increases slightly at 25 mN. It also decreases with increasing applied load. For the textured specimens, the friction coefficient tends to decrease with testing time in both sliding directions studied. In the parallel sliding direction, the friction coefficient decreases with increasing load, attaining values similar to those measured for the polished specimen, while it is independent of the applied load in the perpendicular sliding direction, exhibiting values lower than in the two other cases. These results can be explained by variations in the main contributions to friction and in the wear mechanisms. The influence of the temperature increase at the interface and the consequent changes in the crystalline phases of PTFE are also considered.
The Influence of Early Nutrition on Brain Growth and Neurodevelopment in Extremely Preterm Babies: A Narrative Review
Authors: Cormack Barbara E. , Harding Jane E. , Miller Steven P. , Bloomfield Frank H.
Published: August 2019

Extremely preterm babies are at increased risk of less than optimal neurodevelopment compared with their term-born counterparts. Optimising nutrition is a promising avenue to mitigate the adverse neurodevelopmental consequences of preterm birth. In this narrative review, we summarize current knowledge on how nutrition, and in particular, protein intake, affects neurodevelopment in extremely preterm babies. Observational studies consistently report that higher intravenous and enteral protein intakes are associated with improved growth and possibly neurodevelopment, but differences in methodologies and combinations of intravenous and enteral nutrition strategies make it difficult to determine the effects of each intervention. Unfortunately, there are few randomized controlled trials of nutrition in this population conducted to determine neurodevelopmental outcomes. Substantial variation in reporting of trials, both of nutritional intakes and of outcomes, limits conclusions from meta-analyses. Future studies to determine the effects of nutritional intakes in extremely preterm babies need to be adequately powered to assess neurodevelopmental outcomes separately in boys and girls, and designed to address the many potential confounders which may have clouded research findings to date. The development of minimal reporting sets and core outcome sets for nutrition research will aid future meta-analyses.
Short-Term Effects of the Serious Game “Fit, Food, Fun” on Nutritional Knowledge: A Pilot Study among Children and Adolescents
Authors: Holzmann Sophie Laura , Schäfer Hanna , Groh Georg , Plecher David Alexander , Klinker Gudrun , Schauberger Gunther , Hauner Hans , Holzapfel Christina
Published: August 2019

“Serious games” are a novel and entertaining approach for nutritional education. The aim of this pilot study was to evaluate the short-term effectiveness of “Fit, Food, Fun” (FFF), a serious game to impart nutritional knowledge among children and adolescents. Data collection was conducted at two secondary schools in Bavaria, Germany. The gameplay intervention (gameplay group; GG) consisted of a 15-minute FFF gameplay session during each of three consecutive days. The teaching intervention (teaching group; TG) was performed in a classic lecture format. Nutritional knowledge was evaluated via questionnaires at baseline and post-intervention. Statistical analyses were performed using R (R Core Team, 2018). In total, baseline data were available for 39 participants in the GG and 44 participants in the TG. The mean age was 13.5 ± 0.7 years in the GG and 12.8 ± 0.9 years in the TG. There was a significant (p-value < 0.001) improvement in nutritional knowledge in both intervention groups. Moreover, a between-group difference with a significantly (p-value = 0.01) higher increase in nutritional knowledge was detected for the TG. This pilot study provides evidence for the short-term effectiveness of both educational interventions on the improvement in nutritional knowledge. Finally, the FFF game might be an adequate educational tool for the transfer of nutritional knowledge among children and adolescents.
Conjugated Linoleic Acid Isomers Affect Profile of Lipid Compounds and Intensity of Their Oxidation in Heart of Rats with Chemically-Induced Mammary Tumors—Preliminary Study
Authors: Białek Małgorzata , Białek Agnieszka , Czauderna Marian
Published: August 2019

Breast cancer and cardiovascular diseases (CVD) have shared risk factors and mechanisms of pathogenicity, as proven by increased cardiac risk in breast cancer patients receiving anticancerogenic therapies and in cancer survivors. A growing mammary tumor may cause heart injury in cancer patients who have not yet been treated. This study aimed to evaluate the effect of conjugated linoleic acid (CLA) supplementation of female rats with 7,12-dimethylbenz(a)anthracene (DMBA)-induced cancerogenesis on fatty acids (FAs), conjugated FAs (CFAs), malondialdehyde (MDA), cholesterol and oxysterols content in cardiac tissue. FAs, cholesterol and oxysterols contents were determined by gas chromatography coupled with mass spectrometry, while the contents of CFAs and MDA were determined by high performance liquid chromatography with photodiode detection. Our results indicate that both CLA supplementation and the presence of tumors influence the lipid biomarkers of CVD. A significant interaction of both experimental factors was observed in the content of polyunsaturated FAs (PUFAs), n-6 PUFAs and CFAs. CLA supplementation significantly inhibited PUFA oxidation, as evidenced by the lower content of MDA in rats’ hearts, while the cancerous process intensified the oxidation of cholesterol, as confirmed by the elevated levels of 7-ketocholesterol in DMBA-treated rats. These results may significantly expand knowledge about CLA properties in terms of the prevention of co-existing non-communicable diseases.