bluuebunny/crossref_metadata_2025 huggingface dataset:
Energy and Population in Sub-Saharan Africa: Energy for Four Billion?
Authors: Warner Kevin J. , Jones Glenn A.
Published: September 2018

Sub-Saharan Africa is home to several of the world’s least developed economies. Additionally, forty percent of the nearly one billion people in this region lack access to basic electricity. There are several initiatives and programs aimed at increasing electricity access, clean cooking fuel, and renewable energy around the world. Economic development efforts have traditionally relied on increasing an economy’s use of fossil fuels. However, global climate change agreements and mitigation efforts are in direct contrast with this approach. As such, future development efforts must fit into the larger energy–population–climate nexus of global sustainability. Here we utilise a quantitative approach to examine three scenarios for development in sub-Saharan Africa and compare the results to nine historical examples of economic development. While no perfect development analogue was found, there are several lessons that can be learned from the last half century of efforts. We find that UN projected population growth in the region is expected to outpace non-renewable energy availability. The population of sub-Saharan Africa, and subsequent projected growth (4 billion by 2100), will represent a significant energy and climate strain on the 21st century world. In a larger sense, the social and economic development of sub-Saharan Africa is likely to be tied to an increase in per capita energy consumption. This increase is not going to come from traditional fossil fuels and will therefore require significant investment in a renewable energy infrastructure.
Holistic Assessment of Carbon Capture and Utilization Value Chains
Authors: Pieri Tryfonas , Nikitas Alexandros , Castillo-Castillo Arturo , Angelis-Dimakis Athanasios
Published: September 2018

Carbon capture and utilization (CCU) is recognized by the European Union, along with carbon, capture and storage (CCS), as one of the main tools towards global warming mitigation. It has, thus, been extensively studied by various researchers around the world. The majority of the papers published so far focus on the individual stages of a CCU value chain (carbon capture, separation, purification, transportation, and transformation/utilization). However, a holistic approach, taking into account the matching and the interaction between these stages, is also necessary in order to optimize and develop technically and economically feasible CCU value chains. The objective of this contribution is to present the most important studies that are related to the individual stages of CCU and to perform a critical review of the major existing methods, algorithms and tools that focus on the simulation or optimization of CCU value chains. The key research gaps will be identified and examined in order to lay the foundation for the development of a methodology towards the holistic assessment of CCU value chains.
Impact of Global Change on Nutrient Dynamics in Mangrove Forests
Authors: Alongi Daniel M.
Published: September 2018

The cycling of essential nutrients is central to mangrove productivity. A mass balance shows that mangroves rely on soil ammonification, nitrification, and dissimilatory reduction to ammonium for available nitrogen. Mangroves are often nutrient limited and show tight coupling between nutrient availability and tree photosynthesis. This relationship and, thus, forest productivity can be disrupted by various disturbances such as deforestation, changes in hydrology due to impoundments, land-use change, increasing frequency and intensity of storms, increasing temperatures, increasing atmospheric CO2 concentrations, and a rising sea-level. Deforestation and hydrological changes are the most devastating to soil nutrient-plant relations and mangrove productivity. Land-use changes can result in positive and negative impacts on mangroves and can also results in increasing frequency of storms and intensity of storms. Increasing temperatures and atmospheric CO2 levels have an initially enhanced effect on mangroves and microbial transformation rates of nitrogen and phosphorus. The effects of rising seas are complex and depend on the local rate of sea-level rise, the soil accretion rate, the subsidence or uplift rate, and the tidal position. If mangroves cannot keep pace with a sea-level rise, seaward mangroves will likely drown but landward mangroves will expand and show enhanced growth and more rapid nutrient cycling if space permits.
Between Two Fires: A Fire History of Contemporary America by Dr. Stephen J. Pyne, 1st ed.; University of Arizona Press: Tucson, AZ, USA, 2015
Authors: Fillmore Stephen D.
Published: September 2018

Between Two Fires [1] is one of many books that Dr. Stephen J. Pyne has published about the wildland fire scene.[...]
Lack of Association of Coffee Consumption with the Prevalence of Self-Reported Type 2 Diabetes Mellitus in a Mexican Population: A Cross-Sectional Study
Authors: Gil-Madrigal Ana Karen , González-Castro Thelma Beatriz , Tovilla-Zárate Carlos Alfonso , Aguilar-Velázquez Daniela Georgina , Gómez-Peralta Tania Guadalupe , Juárez-Rojop Isela Esther , López-Narváez María Lilia , Carmona-Díaz Elizabeth , Fresan Ana , Ble-Castillo Jorge Luis , Pérez-Mandujano Antonia , Guzman-Priego Crystell
Published: September 2018

It is estimated that almost 366 million people are currently suffering from diabetes mellitus worldwide. However, it has been suggested that coffee consumption has a protective effect against the development of type 2 diabetes mellitus. This association has been observed in many regions around the world. Today, there are no reports in Mexico regarding this association. Therefore, the aim of this study was to assess the association between coffee intake and self-reported type 2 diabetes mellitus in the southeastern part of Mexico. This study included 1277 residents of Comalcalco, a municipality of Tabasco State, Mexico. We calculated the prevalence for diabetes and performed multivariate analysis using multiple logistic regressions to evaluate the combined association with type 2 diabetes mellitus. The prevalence of the diabetes was 12.52% (95% CI: 10.67–14.38). The majority of people surveyed (77.29%; 95% CI: 74.95–79.60) indicated they were coffee drinkers. The results of multivariate analysis showed a non-significant relationship between the number of cups of coffee drank and type 2 diabetes mellitus. The adjusted odds ratio gave the following values: 1.20, (95% CI: 0.59–2.41) for non-daily consumption; 1.66 (0.82–3.34), for 1 cup of coffee peer day, and 1.49 (0.78–2.86) for 2–3 cups. Subsequently, an adjustment was made for age, gender, marital status, education, alcohol consumption, and cigarette smoking. In our population, we did not observe an association between coffee intake and its protective relationship with self-reported type 2 diabetes mellitus.
Gender, Marital Status, and Children as Risk Factors for Burnout in Nurses: A Meta-Analytic Study
Authors: Cañadas-De la Fuente Guillermo A. , Ortega Elena , Ramirez-Baena Lucia , De la Fuente-Solana Emilia I. , Vargas Cristina , Gómez-Urquiza Jose Luis
Published: September 2018

The correlation between the burnout syndrome and sociodemographic variables in nursing professionals has been widely studied though research results are contradictory. The aim of this study was to assess the impact of gender, marital status, and children on the dimensions of the burnout syndrome (emotional exhaustion, depersonalization, and personal accomplishment) in nursing professionals, as measured with the Maslach Burnout Inventory. The search was performed in May 2018 in the next databases: CINAHL, CUIDEN, Dialnet, Psicodoc, ProQuest Platform, OVID Platform, and Scopus with the search equation (“Maslach Burnout Inventory” OR “MBI”) AND “nurs*”, without using any search restriction. The sample was n = 78 studies: 57 studies for gender; 32 for marital status; 13 for having children. A statistically significant relation between depersonalization and gender (r = 0.078), marital status (r = 0.047), and children (r = 0.053) was found. A significant relation was also found between emotional exhaustion and children (r = 0.048). The results showed that being male, being single or divorced, and not having children were related to the highest levels of burnout in nurses. Moreover, these relations could be accentuated by the influence of moderator variables (age, seniority, job satisfaction, etc.), which, in combination with the previously mentioned significant relations, should be evaluated in the design burnout risk profiles for nursing professionals.
Optimized Expression and Characterization of a Novel Fully Human Bispecific Single-Chain Diabody Targeting Vascular Endothelial Growth Factor165 and Programmed Death-1 in Pichia pastoris and Evaluation of Antitumor Activity In Vivo
Authors: Xiong Chenghao , Mao Yingqing , Wu Tao , Kang Nannan , Zhao Mingjun , Di Rongrong , Li Xiaoping , Ji Xuemei , Liu Yu
Published: September 2018

Bispecific antibodies, which can bind to two different epitopes on the same or different antigens simultaneously, have recently emerged as attractive candidates for study in various diseases. Our present study successfully constructs and expresses a fully human, bispecific, single-chain diabody (BsDb) that can bind to vascular endothelial growth factor 165 (VEGF165) and programmed death-1 (PD-1) in Pichia pastoris. Under the optimal expression conditions (methanol concentration, 1%; pH, 4.0; inoculum density, OD600 = 4, and the induction time, 96 h), the maximum production level of this BsDb is achieved at approximately 20 mg/L. The recombinant BsDb is purified in one step using nickel-nitrilotriacetic acid (Ni-NTA) column chromatography with a purity of more than 95%. Indirect enzyme-linked immune sorbent assay (ELISA) and sandwich ELISA analyses show that purified BsDb can bind specifically to VEGF165 and PD-1 simultaneously with affinities of 124.78 nM and 25.07 nM, respectively. Additionally, the BsDb not only effectively inhibits VEGF165-stimulated proliferation, migration, and tube formation in primary human umbilical vein endothelial cells (HUVECs), but also significantly improves proliferation and INF-γ production of activated T cells by blocking PD-1/PD-L1 co-stimulation. Furthermore, the BsDb displays potent antitumor activity in mice bearing HT29 xenograft tumors by inhibiting tumor angiogenesis and activating immune responses in the tumor microenvironment. Based on these results, we have prepared a potential bispecific antibody drug that can co-target both VEGF165 and PD-1 for the first time. This work provides a stable foundation for the development of new strategies by the combination of an angiogenesis inhibition and immune checkpoint blockade for cancer therapy.
Renal Injury during Long-Term Crizotinib Therapy
Authors: Yasuma Taro , Kobayashi Tetsu , D’Alessandro-Gabazza Corina N. , Fujimoto Hajime , Ito Kentaro , Nishii Yoichi , Nishihama Kota , Baffour Tonto Prince , Takeshita Atsuro , Toda Masaaki , Gabazza Esteban C. , Taguchi Osamu , Yonemura Shigenori , Hataji Osamu
Published: September 2018

Crizotinib is highly effective against anaplastic lymphoma kinase-positive and c-ros oncogen1-positive non-small cell lung cancer. Renal dysfunction is associated with crizotinib therapy but the mechanism is unknown. Here, we report a case of anaplastic lymphoma kinase positive non-small cell lung cancer showing multiple cysts and dysfunction of the kidneys during crizotinib administration. We also present results demonstrating that long-term crizotinib treatment induces fibrosis and dysfunction of the kidneys by activating the tumor necrosis factor-α/nuclear factor-κB signaling pathway. In conclusion, this study shows the renal detrimental effects of crizotinib, suggesting the need of careful monitoring of renal function during crizotinib therapy.
Metabolic Effects of Oral Phenelzine Treatment on High-Sucrose-Drinking Mice
Authors: Carpéné Christian , Gómez-Zorita Saioa , Chaplin Alice , Mercader Josep
Published: September 2018

Phenelzine has been suggested to have an antiobesity effect by inhibiting de novo lipogenesis, which led us to investigate the metabolic effects of oral chronic phenelzine treatment in high-sucrose-drinking mice. Sucrose-drinking mice presented higher body weight gain and adiposity versus controls. Phenelzine addition did not decrease such parameters, even though fat pad lipid content and weights were not different from controls. In visceral adipocytes, phenelzine did not impair insulin-stimulated de novo lipogenesis and had no effect on lipolysis. However, phenelzine reduced the mRNA levels of glucose transporters 1 and 4 and phosphoenolpyruvate carboxykinase in inguinal white adipose tissue (iWAT), and altered circulating levels of free fatty acids (FFA) and glycerol. Interestingly, glycemia was restored in phenelzine-treated mice, which also had higher insulinaemia. Phenelzine-treated mice presented higher rectal temperature, which was associated to reduced mRNA levels of uncoupling protein 1 in brown adipose tissue. Furthermore, unlike sucrose-drinking mice, hepatic malondialdehyde levels were not altered. In conclusion, although de novo lipogenesis was not inhibited by phenelzine, the data suggest that the ability to re-esterify FFA is impaired in iWAT. Moreover, the effects on glucose homeostasis and oxidative stress suggest that phenelzine could alleviate obesity-related alterations and deserves further investigation in obesity models.
The Multifarious Functions of Pyruvate Kinase M2 in Oral Cancer Cells
Authors: Kurihara-Shimomura Miyako , Sasahira Tomonori , Nakashima Chie , Kuniyasu Hiroki , Shimomura Hiroyuki , Kirita Tadaaki
Published: September 2018

Head and neck cancers, including oral squamous cell carcinoma (OSCC), are the sixth most common malignancies worldwide. OSCC frequently leads to oral dysfunction, which worsens a patient’s quality of life. Moreover, its prognosis remains poor. Unlike normal cells, tumor cells preferentially metabolize glucose by aerobic glycolysis. Pyruvate kinase (PK) catalyzes the final step in glycolysis, and the transition from PKM1 to PKM2 is observed in many cancer cells. However, little is known about PKM expression and function in OSCC. In this study, we investigated the expression of PKM in OSCC specimens and performed a functional analysis of human OSCC cells. We found that the PKM2/PKM1 ratio was higher in OSCC cells than in adjacent normal mucosal cells and in samples obtained from dysplasia patients. Furthermore, PKM2 expression was strongly correlated with OSCC tumor progression on immunohistochemistry. PKM2 expression was higher during cell growth, invasion, and apoptosis in HSC3 cells, which show a high energy flow and whose metabolism depends on aerobic glycolysis and oxidative phosphorylation. PKM2 expression was also associated with the production of reactive oxygen species (ROS) and integration of glutamine into lactate. Our results suggested that PKM2 has a variety of tumor progressive functions in OSCC cells.
Botanically Templated Monolithic Macrostructured Zinc Oxide Materials for Photocatalysis
Authors: Black Nathan M. , Ciota David S. , Gillan Edward G.
Published: September 2018

With an increased focus on light energy to facilitate catalytic processes, photocatalysts have been intensively studied for a wide range of energy and environmental applications. In this report, we describe the use of chemically dehydrated leaves as sacrificial foam-like templates for the growth of monolithic macrostructured semiconducting zinc oxide and nickel or cobalt doped zinc oxide materials. The composition and structure of these templated zinc oxides were characterized using X-ray powder diffraction, scanning electron microscopy, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy. Optical properties were examined using solid-state UV–vis diffuse reflectance spectroscopy. The metal-doped ZnO materials have enhanced visible absorption and lower band gaps as compared to ZnO. The botanically templated ZnO materials retain the macroscopic cellular form of the leaf template with fused nanoparticle walls. Their UV photocatalytic oxidative abilities were investigated using methylene blue dye degradation in air. The leaf templated zinc oxides degrade ~85% of methylene blue dye with 30 min of UV illumination. Nickel and cobalt doped zinc oxides showed varying degrees of decreased UV and visible light photocatalytic activity, possibly due to metal-mediated charge recombination. The mild chemical dehydration process here allows complex soft botanical structures to be easily utilized for templating materials.
Application of Trap Cropping as Companion Plants for the Management of Agricultural Pests: A Review
Authors: Sarkar Shovon Chandra , Wang Endong , Wu Shengyong , Lei Zhongren
Published: September 2018

Companion planting is a well-known strategy to manage insect pests and support a natural enemy population through vegetative diversification. Trap cropping is one such type of special companion planting strategy that is traditionally used for insect pest management through vegetative diversification used to attract insect pests away from the main crops during a critical time period by providing them an alternative preferred choice. Trap crops not only attract the insects for feeding and oviposition, but also act as a sink for any pathogen that may be a vector. Considerable research has been conducted on different trap crops as companion plant species to develop improved pest management strategies. Despite this, little consensus exists regarding optimal trap cropping systems for diverse pest management situations. An advantage of trap cropping over an artificially released natural enemy-based biological control could be an attractive remedy for natural enemies in cropping systems. Besides, many trap crop species can conserve natural enemies. This secondary effect of attracting natural enemies may be an advantage compared to the conventional means of pest control. However, this additional consideration requires a more knowledge-intensive background to designing an effective trap cropping system. We have provided information based on different trap crops as companion plant, their functions and an updated list of trap cropping applications to attract insect pests and natural enemies that should be proven as helpful in future trap cropping endeavors.
GPU Acceleration of the Most Apparent Distortion Image Quality Assessment Algorithm
Authors: Holloway Joshua , Kannan Vignesh , Zhang Yi , Chandler Damon M. , Sohoni Sohum
Published: September 2018

The primary function of multimedia systems is to seamlessly transform and display content to users while maintaining the perception of acceptable quality. For images and videos, perceptual quality assessment algorithms play an important role in determining what is acceptable quality and what is unacceptable from a human visual perspective. As modern image quality assessment (IQA) algorithms gain widespread adoption, it is important to achieve a balance between their computational efficiency and their quality prediction accuracy. One way to improve computational performance to meet real-time constraints is to use simplistic models of visual perception, but such an approach has a serious drawback in terms of poor-quality predictions and limited robustness to changing distortions and viewing conditions. In this paper, we investigate the advantages and potential bottlenecks of implementing a best-in-class IQA algorithm, Most Apparent Distortion, on graphics processing units (GPUs). Our results suggest that an understanding of the GPU and CPU architectures, combined with detailed knowledge of the IQA algorithm, can lead to non-trivial speedups without compromising prediction accuracy. A single-GPU and a multi-GPU implementation showed a 24× and a 33× speedup, respectively, over the baseline CPU implementation. A bottleneck analysis revealed the kernels with the highest runtimes, and a microarchitectural analysis illustrated the underlying reasons for the high runtimes of these kernels. Programs written with optimizations such as blocking that map well to CPU memory hierarchies do not map well to the GPU’s memory hierarchy. While compute unified device architecture (CUDA) is convenient to use and is powerful in facilitating general purpose GPU (GPGPU) programming, knowledge of how a program interacts with the underlying hardware is essential for understanding performance bottlenecks and resolving them.
Who’s Talking About Us Without Us? A Survivor Research Interjection into an Academic Psychiatry Debate on Compulsory Community Treatment Orders in Ireland
Authors: Brosnan Liz
Published: September 2018

This paper presents a user/survivor researcher perspective to the debate among psychiatrists on the suggested introduction of Community Treatment Orders in Ireland. Critical questions are raised about evidence and the construction of psychiatric knowledge. Important questions include: How is this evidence created? What and whose knowledge have not been considered? Some critical issues around coercion, ‘insight’, and attributions of ‘lack of capacity’ are briefly considered. Further legal considerations are then introduced based on the United Nations Convention on the Rights of Persons with Disability. The paper concludes with a human rights-based appeal to reject the introduction of coercive community treatment in Ireland.
Efficient Arrangement of the Replication Fork Trap for In Vitro Propagation of Monomeric Circular DNA in the Chromosome-Replication Cycle Reaction
Authors: Hasebe Tomonori , Narita Kouhei , Hidaka Shiomi , Su’etsugu Masayuki
Published: September 2018

Propagation of genetic information is a fundamental prerequisite for living cells. We recently developed the replication cycle reaction (RCR), an in vitro reaction for circular DNA propagation, by reconstitution of the replication cycle of the Escherichia coli chromosome. In RCR, two replication forks proceed bidirectionally from the replication origin, oriC, and meet at a region opposite oriC, yielding two copies of circular DNA. Although RCR essentially propagates supercoiled monomers, concatemer byproducts are also produced due to inefficient termination of the replication fork progression. Here, we examined the effect of the Tus-ter replication fork trap in RCR. Unexpectedly, when the fork traps were placed opposite oriC, mimicking their arrangement on the chromosome, the propagation of circular DNA was inhibited. On the other hand, fork traps flanking oriC allowed efficient propagation of circular DNA and repressed concatemer production. These findings suggest that collision of the two convergence forks through the fork trap is detrimental to repetition of the replication cycle. We further demonstrate that this detrimental effect was rescued by the UvrD helicase. These results provide insights into the way in which circular DNA monomers replicate repetitively without generating concatemers.
Experimental Investigation on Form Error for Slow Tool Servo Diamond Turning of Micro Lens Arrays on the Roller Mold
Authors: Liu Yutao , Qiao Zheng , Qu Da , Wu Yangong , Xue Jiadai , Li Duo , Wang Bo
Published: September 2018

Slow tool servo (STS) assisted ultra-precision diamond turning is considered as a promising machining process with high accuracy and low cost to generate the large-area micro lens arrays (MLAs) on the roller mold. However, the chatter mark is obvious at the cut-in part of every machined micro lens along the cutting direction, which is a common problem for the generation of MLAs using STS. In this study, a novel forming approach based on STS is presented to fabricate MLAs on the aluminum alloy (6061) roller mold, which is a high-efficiency machining approach in comparison to a traditional method based on STS. Based on the different distribution patterns of the discrete point of micro lens, the equal-arc method and the equal-angle method are also proposed to generate the tool path. According to a kinematic analysis of the cutting axis, the chatter mark results from the overlarge instantaneous acceleration oscillations of the cutting axis during STS diamond turning process of MLAs. Cutting parameters including the number of discrete points and cutting time of every discrete point have been experimentally investigated to reduce the chatter mark. Finally, typical MLAs (20.52-μm height and 700-μm aperture) is successfully machined with the optimal cutting parameters. The results are acquired with a fine surface quality, i.e., form error of micro lenses is 0.632 μm, which validate the feasibility of the new machining method.
Investigation of Fatigue Behavior of ABS and PC-ABS Polymers at Different Temperatures
Authors: Mura Andrea , Ricci Alessando , Canavese Giancarlo
Published: September 2018

Plastics are widely used in structural components where cyclic loads may cause fatigue failure. In particular, in some applications such as in vehicles, the working temperature may change and therefore the strength of the polymeric materials. In this work, the fatigue behavior of two thermoplastic materials (ABS and PC-ABS) at different temperatures has been investigated. In particular, three temperatures have been considered representing the working condition at room temperature, at low temperature (winter conditions), and high temperature (summer conditions and/or components close to the engine). Results show that high temperature have big impact on fatigue performance, while low temperatures may also have a slight positive effect.
The Effect of a Scanning Strategy on the Residual Stress of 316L Steel Parts Fabricated by Selective Laser Melting (SLM)
Authors: Wang Di , Wu Shibiao , Yang Yongqiang , Dou Wenhao , Deng Shishi , Wang Zhi , Li Sheng
Published: September 2018

The laser scanning strategy has an important influence on the surface quality, residual stress, and deformation of the molten metal (deformation behavior). A divisional scanning strategy is an effective means used to reduce the internal stress of the selective laser melting (SLM) metal part. In order to understand and optimize the divisional scanning strategy, three divisional scanning strategies and an S-shaped orthogonal scanning strategy are used to produce 316L steel parts in this study. The influence of scanning strategy on the produced parts is verified from the aspects of densification, residual stress distribution and deformation. Experiments show that the 316L steel alloy parts adopted spiral divisional scanning strategy can not only obtain the densification of 99.37%, but they also effectively improve the distribution of residual stress and control the deformation degree of the produced parts. Among them, the spiral divisional scanning sample has the smallest residual stress in plane direction, and its σx and σy stress are controlled within 204 MPa and 103 MPa. The above results show that the spiral divisional scanning is the most conducive strategy to obtain higher residual stress performance of SLM 316L steel parts.
Research on the Crack Risk of Early-Age Concrete under the Temperature Stress Test Machine
Authors: Liu Longlong , Ouyang Jianshu , Li Feilong , Xin Jianda , Huang Dahai , Gao Shuling
Published: September 2018

A new temperature stress test machine (TSTM) was developed to improve temperature control accuracy and efficiency. As there is no uniform standard for the threshold value of TSTM, quite different threshold values are used in the test, which results in the influences of the threshold value on the evaluation of thermal stresses and crack risk of concrete not being determined. To illustrate the importance of an appropriate threshold value, different threshold values were used to evaluate the influences on the thermal stresses and cracking resistance of concrete specimens under a complete restraint test with semi-adiabatic temperature development. The results show that the maximum compressive stress of a concrete specimen with a threshold value 3 με was slightly larger than that of 1.5 με when the growth rate of tensile stress of the concrete specimen with the threshold value 3 με was slightly greater than that of concrete specimen with the threshold value 1.5 με. Based on the combination of crack risk coefficient and restraint degree, a new system for evaluating the crack resistance of concrete was proposed, in which different threshold values were used to estimate their influences on the crack risk of concrete. Thus, an appropriate range of threshold values could be determined.
Yb2O3 Doped Zr0.92Y0.08O2-α(8YSZ) and Its Composite Electrolyte for Intermediate Temperature Solid Oxide Fuel Cells
Authors: Cui Yumin , Shi Ruijuan , Liu Junlong , Wang Hongtao , Li Huiquan
Published: September 2018

Yb3+ and Y3+ double doped ZrO2 (8YSZ+4Yb2O3) samples were synthesized by a solid state reaction method. Moreover, 8YSZ+4Yb2O3-NaCl/KCl composites were also successfully produced at different temperatures. The 8YSZ+4Yb2O3, 8YSZ+4Yb2O3-NaCl/KCl (800 °C), and 8YSZ+4Yb2O3-NaCl/KCl (1000 °C) samples were characterized by x–ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that a dense composite electrolyte was formed at a low temperature of 800 °C. The maximum conductivities of 4.7 × 10−2 S·cm−1, 6.1 × 10−1 S·cm−1, and 3.8 × 10−1 S·cm−1 were achieved for the 8YSZ+4Yb2O3, 8YSZ+4Yb2O3-NaCl/KCl (800 °C), and 8YSZ+4Yb2O3-NaCl/KCl (1000 °C) samples at 700 °C, respectively. The logσ~log (pO2) plot result showed that the 8YSZ+4Yb2O3-NaCl/KCl (800 °C) composite electrolyte is a virtually pure ionic conductor. An excellent performance of the 8YSZ+4Yb2O3-NaCl/KCl (800 °C) composite was obtained with a maximum power density of 364 mW·cm−2 at 700 °C.
Evaluation of the Rosemary Extract Effect on the Properties of Polylactic Acid-Based Materials
Authors: Darie-Niţă Raluca Nicoleta , Vasile Cornelia , Stoleru Elena , Pamfil Daniela , Zaharescu Traian , Tarţău Liliana , Tudorachi Niţă , Brebu Mihai Adrian , Pricope Gina Mihaela , Dumitriu Raluca Petronela , Leluk Karol
Published: September 2018

New multifunctional materials containing additives derived from natural resources as powdered rosemary ethanolic extract were obtained by melt mixing and processed in good conditions without degradation and loss of additives. Incorporation of powdered rosemary ethanolic extract (R) into poly(lactic acid) (PLA) improved elongation at break, rheological properties, antibacterial and antioxidant activities, in addition to the biocompatibility. The good accordance between results of the chemiluminescence method and radical scavenging activity determination by chemical method evidenced the increased thermoxidative stability of the PLA biocomposites with respect to neat PLA, with R acting as an antioxidant. PLA/R biocomposites also showed low permeability to gases and migration rates of the bioactive compounds and could be considered as high-performance materials for food packaging. In vitro biocompatibility based on the determination of surface properties demonstrated a good hydrophilicity, better spreading and division of fibroblasts, and increased platelet cohesion. The implantation of PLA/R pellets, was proven to possess a good in vivo biocompatibility, and resulted in similar changes in blood parameters and biochemical responses with the control group, suggesting that these PLA-based materials demonstrate very desirable properties as potential biomaterials, useful in human medicine for tissue engineering, wound management, orthopedic devices, scaffolds, drug delivery systems, etc. Therefore, PLA/R-based materials show promising properties for applications both in food packaging and as bioactive biomaterials.
Green’s Classifications and Evolutions of Fixed-Order Networks
Authors: Parks Allen D.
Published: September 2018

It is shown that the set of all networks of fixed order n form a semigroup that is isomorphic to the semigroup B X of binary relations on a set X of cardinality n . Consequently, B X provides for Green’s L , R , H , and D equivalence classifications of all networks of fixed order n . These classifications reveal that a fixed-order network which evolves within a Green’s equivalence class maintains certain structural invariants during its evolution. The “Green’s symmetry problem” is introduced and is defined as the determination of all symmetries (i.e., transformations) that produce an evolution between an initial and final network within an L or an R class such that each symmetry preserves the required structural invariants. Such symmetries are shown to be solutions to special Boolean equations specific to each class. The satisfiability and computational complexity of the “Green’s symmetry problem” are discussed and it is demonstrated that such symmetries encode information about which node neighborhoods in the initial network can be joined to form node neighborhoods in the final network such that the structural invariants required by the evolution are preserved, i.e., the internal dynamics of the evolution. The notion of “propensity” is also introduced. It is a measure of the tendency of node neighborhoods to join to form new neighborhoods during a network evolution and is used to define “energy”, which quantifies the complexity of the internal dynamics of a network evolution.
The Cocktail Effect of BMP-2 and TGF-β1 Loaded in Visible Light-Cured Glycol Chitosan Hydrogels for the Enhancement of Bone Formation in a Rat Tibial Defect Model
Authors: Yoon Sun-Jung , Yoo Youngbum , Nam Sang Eun , Hyun Hoon , Lee Deok-Won , Um Sewook , Kim So Yeon , Hong Sung Ok , Yang Dae Hyeok , Chun Heung Jae
Published: September 2018

Bone tissue engineering scaffolds offer the merits of minimal invasion as well as localized and controlled biomolecule release to targeted sites. In this study, we prepared injectable hydrogel systems based on visible light-cured glycol chitosan (GC) hydrogels containing bone morphogenetic protein-2 (BMP-2) and/or transforming growth factor-beta1 (TGF-β1) as scaffolds for bone formation in vitro and in vivo. The hydrogels were characterized by storage modulus, scanning electron microscopy (SEM) and swelling ratio analyses. The developed hydrogel systems showed controlled releases of growth factors in a sustained manner for 30 days. In vitro and in vivo studies revealed that growth factor-loaded GC hydrogels have no cytotoxicity against MC3T3-E1 osteoblast cell line, improved mRNA expressions of alkaline phosphatase (ALP), type I collagen (COL 1) and osteocalcin (OCN), and increased bone volume (BV) and bone mineral density (BMD) in tibia defect sites. Moreover, GC hydrogel containing BMP-2 (10 ng) and TGF-β1 (10 ng) (GC/BMP-2/TGF-β1-10 ng) showed greater bone formation abilities than that containing BMP-2 (5 ng) and TGF-β1 (5 ng) (GC/BMP-2/TGF-β1-5 ng) in vitro and in vivo. Consequently, the injectable GC/BMP-2/TGF-β1-10 ng hydrogel may have clinical potential for dental or orthopedic applications.
Conditioning of Spent Stripping Solution for the Recovery of Metals
Authors: Ebner Tamara , Luidold Stefan , Honner Matthias , Antrekowitsch Helmut , Czettl Christoph
Published: September 2018

The objective of this study was to develop an eco-friendly method for processing spent stripping solutions, which originate from the wet chemical decoating of metal cutting tools, to generate a product that represents a useful basis for the recovery of valuable components. These liquids contain, for example, considerable quantities of Ti, Co, and W. Hence, the treatment of these solutions, especially because of the dissolved Co, is essential. The process is based on the precipitation of an insoluble compound with the use of a Ca source. The thermal treatment of the precipitate enables its reuse in the procedure, which leads to a minimum amount of solid process waste. The suggested method, which can be readily controlled by pH adjustment, results in a reduction of hazardous substances and an enrichment of valuable compounds in the solid product. Therefore, this process represents an effective preliminary step in the recovery of concentrated metals, such as Ti.
Application of a GTN Damage Model Predicting the Fracture of 5052-O Aluminum Alloy High-Speed Electromagnetic Impaction
Authors: Feng Fei , Li Jianjun , Yuan Peng , Zhang Qixian , Huang Pan , Su Hongliang , Chen Rongchuang
Published: September 2018

An increasing demand exists within the automotive industry to utilize aluminum alloy sheets because of their excellent strength-weight ratio and low emissions, which can improve fuel economy and reduce environmental pollution. High-speed automobile impactions are complicated and highly nonlinear deformation processes. Thus, in this paper, a Gurson-Tvergaard-Needleman (GTN) damage model is used to describe the damage behavior of high-speed electromagnetic impaction to predict the fracture behavior of 5052-O aluminum alloy under high-speed impaction. The parameters of the GTN damage model are obtained based on high-speed electromagnetic forming experiments via scanning electron microscopy. The high-speed electromagnetic impaction behavior process is analyzed according to the obtained GTN model parameters. The shape of the high-speed electromagnetic impaction in the numerical simulations agrees with the experimental results. The analysis of the plastic strain and void volume fraction distributions are analyzed during the process of high-speed impact, which indicates the validity of using the GTN damage model to describe or predict the fracture behavior of high-speed electromagnetic impaction.
Microstructure and Mechanical Behavior of Al-Mg Composites Synthesized by Reactive Sintering
Authors: Shahid Rub Nawaz , Scudino Sergio
Published: September 2018

Lightweight metal matrix composites are synthesized from elemental powder mixtures of aluminum and magnesium using pressure-assisted reactive sintering. The effect of the reaction between aluminum and magnesium on the microstructure and mechanical properties of the composites due to the formation of β-Al3Mg2 and γ-Al12Mg17 intermetallics is investigated. The formation of the intermetallic compounds progressively consumes aluminum and magnesium and induces strengthening of the composites: the yield and compressive strengths increase with the increase of the content of intermetallic reinforcement at the expense of the plastic deformation. The yield strength of the composites follows the iso-stress model when the data are plotted as a function of the intermetallic content.
On Frequency-Based Interface Circuits for Capacitive MEMS Accelerometers
Authors: Qiao Zhiliang , Boom Boris A. , Annema Anne-Johan , Wiegerink Remco J. , Nauta Bram
Published: September 2018

Interface circuits for capacitive MEMS accelerometers are conventionally based on charge-based approaches. A promising alternative to these is provided by frequency-based readout techniques that have some unique advantages as well as a few challenges associated with them. This paper addresses these techniques and presents a derivation of the fundamental resolution limits that are imposed on them by phase noise. Starting with an overview of basic operating principles, associated properties and challenges, the discussions then focus on the fundamental trade-offs between noise, power dissipation and signal bandwidth (BW) for the LC-oscillator-based frequency readout and for the conventional charge-based switched-capacitor (SC) readout. Closed-form analytical formulas are derived to facilitate a fair comparison between the two approaches. Benchmarking results indicate that, with the same bandwidth requirement, charge-based readout circuits are more suitable when optimizing for noise performance, while there is still some room for frequency-based techniques when optimizing for power consumption, especially when flicker phase noise can be mitigated.
Development and Characterization of Non-Evaporable Getter Thin Films with Ru Seeding Layer for MEMS Applications
Authors: Bourim El-Mostafa , Kim Hee Yeoun , Chung Nak-Kwan
Published: September 2018

Mastering non-evaporable getter (NEG) thin films by elucidating their activation mechanisms and predicting their sorption performances will contribute to facilitating their integration into micro-electro-mechanical systems (MEMS). For this aim, thin film based getters structured in single and multi-metallic layered configurations deposited on silicon substrates such as Ti/Si, Ti/Ru/Si, and Zr/Ti/Ru/Si were investigated. Multilayered NEGs with an inserted Ru seed sub-layer exhibited a lower temperature in priming the activation process and a higher sorption performance compared to the unseeded single Ti/Si NEG. To reveal the gettering processes and mechanisms in the investigated getter structures, thermal activation effect on the getter surface chemical state change was analyzed with in-situ temperature XPS measurements, getter sorption behavior was measured by static pressure method, and getter dynamic sorption performance characteristics was measured by standard conductance (ASTM F798–97) method. The correlation between these measurements allowed elucidating residual gas trapping mechanism and prediction of sorption efficiency based on the getter surface poisoning. The gettering properties were found to be directly dependent on the different changes of the getter surface chemical state generated by the activation process. Thus, it was demonstrated that the improved sorption properties, obtained with Ru sub-layer based multi-layered NEGs, were related to a gettering process mechanism controlled simultaneously by gas adsorption and diffusion effects, contrarily to the single layer Ti/Si NEG structure in which the gettering behavior was controlled sequentially by surface gas adsorption until reaching saturation followed then by bulk diffusion controlled gas sorption process.
Universal Testing Apparatus Implementing Various Repetitive Mechanical Deformations to Evaluate the Reliability of Flexible Electronic Devices
Authors: Kim Cheol , Kim Chung
Published: September 2018

A requirement of flexible electronic devices is that they maintain their electrical performance during and after repetitive mechanical deformation. Accordingly, in this study, a universal test apparatus is developed for in-situ electrical conductivity measurements for flexible electrodes that are capable of applying various mechanical deformations such as bending, twisting, shearing, sliding, stretching, and complex modes consisting of two simultaneous deformations. A novel method of deforming the specimen in an arc to induce uniform bending stress in single and alternating directions is also proposed with a mathematically derived control method. As an example of the arc bending method, the changes in the resistance of the printed radio frequency identification (RFID) tag antennas were measured by applying repetitive inner bending, outer bending, and alternating inner-outer bending. After 5000 cycles, the increases in resistance of the specimens that were subjected to inner or outer bending only were under 30%; however, specimens that were subjected to alternating inner-outer bending showed an increase of 135% in resistance. It is critical that the reliability of flexible electronic devices under various mechanical deformations be determined before they can be commercialized. The proposed testing apparatus can readily provide various deformations that will be useful to inform the design of device shapes and structures to accommodate deformations during use.
Antioxidant and Fluorescence Properties of Hydrogenolyzised Polymeric Proanthocyanidins Prepared Using SO42−/ZrO2 Solid Superacids Catalyst
Authors: Ni Liwen , Zhao Fanbin , Li Bolun , Wei Tong , Guan Hang , Ren Shixue
Published: September 2018

Larix bark oligomeric proanthocyanidins (LOPC) were prepared from larix bark polymeric proanthocyanidins (LPPC) by catalytic hydrogenolysis using SO42−/ZrO2 solid superacid as the catalyst. The catalyst to polymeric proanthocyanidins ratio was 0.2:1 (m/m). The LOPC, obtained after hydrogenolysis at 100 °C for 4 h under 3 MPa hydrogen pressure, retained the structural characteristics of proanthocyanidins. The average degree of polymerization was reduced from 9.50% to 4.76% and the depolymerization yield was 53.85%. LOPC has good antioxidant properties and, at the same concentration, the reducing ability of LOPC was much higher than that of LPPC. The IC50 values of LOPC for scavenging DPPH• and ABTS•+ radicals were 0.046 mg/mL and 0.051 mg/mL, respectively. LOPC is biocompatible and has fluorescent properties that are affected by external factors, such as solvent polarity, pH and the presence of different metal ions. These features indicate that LOPC could be developed as a new biological fluorescent marker. The depolymerization of low-value polymeric proanthocyanidins to provide high-value oligomeric proanthocyanidins and the development of new applications for proanthocyanidins represent significant advances.
Antioxidant Properties of the Vam3 Derivative of Resveratrol
Authors: Ahmadi Seyedmohammad , Marino Tiziana , Prejanò Mario , Russo Nino , Toscano Marirosa
Published: September 2018

A considerable number of studies has shown that many constituents of foods derived from plants are effective and safe antioxidants. This explains the growing interest in natural antioxidants in food applications. The goal of this investigation was to evaluate the antioxidant properties of the Vam3, a resveratrol derivative, firstly isolated from ethanol extracts of Vitis amurensis Rupr as a secondary product, and to carry out a comparison with resveratrol and other phenolic compounds which are currently in the limelight all over the world due to their beneficial effects on the human body. The potential of Vam3 as an antioxidant was determined through the evaluation of some key thermodynamic parameters which are commonly used for this purpose and describe the antioxidant activity quite well. Various mechanisms through which antioxidants usually can carry out their action were also explored both in water and in apolar environment. The results indicated that Vam3 is an excellent candidate as a natural antioxidant.
Azukisapogenol Triterpene Glycosides from Oxytropis chiliophylla Royle
Authors: Wang Jun , Yang Hongshuai , Liu Yang , Norbo Kelsang , Zeng Kewu , Zhao Mingbo , Liang Hong , Tu Pengfei , Zhang Qingying
Published: September 2018

Eight azukisapogenol triterpene glycosides, including five new compounds, oxychiliotriterpenosides A–E (1–5), two new methyl glucuronide derivatives that proved to be artifacts, oxychiliotriterpenoside E-glucuronic acid methyl ester (6) and myrioside B-glucuronic acid methyl ester (7), and a known one, myrioside B (8), was isolated from the aerial part of Oxytropis chiliophylla Royle. Their structures were elucidated based on extensive spectroscopic analyses and chemical methods. Triterpene glycosides were first obtained from O. chiliophylla, and those containing a galactose unit (1, 2, 5 and 6) and diglucosidic or triglucosidic linkage at C-29 (1–4), were reported from Oxytropis species for the first time, which might be recognized as a chemotaxonomic feature of O. chiliophylla. All isolated compounds were evaluated for their anti-inflammatory activities against NO production using lipopolysaccharide (LPS)-induced RAW 264.7 cells, but no compounds showed potent inhibition on NO production.