bluuebunny/crossref_metadata_2025 huggingface dataset:
Nasal Decolonisation of MRSA
Authors: Mantle Peter
Published: February 2019

The recent demonstration for the first time of urinary monic acid A as a clinical urinary biomarker of exposure to intra-nasal mupirocin during medication for methicillin-resistant Staphylococcus aureus (MRSA) offers a way of verifying adherence to the regimen. However, absence of the biomarker in some patients needs explanation, to ensure that efficient decolonisation has not been compromised by confounding circumstances, and that additional resistance to mupirocin has not unwittingly been encouraged.
Chronic Inhibition of Mitochondrial Dihydrolipoamide Dehydrogenase (DLDH) as an Approach to Managing Diabetic Oxidative Stress
Authors: Yang Xiaojuan , Song Jing , Yan Liang-Jun
Published: February 2019

Mitochondrial dihydrolipoamide dehydrogenase (DLDH) is a redox enzyme involved in decarboxylation of pyruvate to form acetyl-CoA during the cascade of glucose metabolism and mitochondrial adenine triphosphate (ATP) production. Depending on physiological or pathophysiological conditions, DLDH can either enhance or attenuate the production of reactive oxygen species (ROS) and reactive nitrogen species. Recent research in our laboratory has demonstrated that inhibition of DLDH induced antioxidative responses and could serve as a protective approach against oxidative stress in stroke injury. In this perspective article, we postulated that chronic inhibition of DLDH could also attenuate oxidative stress in type 2 diabetes. We discussed DLDH-involving mitochondrial metabolic pathways and metabolic intermediates that could accumulate upon DLDH inhibition and their corresponding roles in abrogating oxidative stress in diabetes. We also discussed a couple of DLDH inhibitors that could be tested in animal models of type 2 diabetes. It is our belief that DLDH inhibition could be a novel approach to fighting type 2 diabetes.
Equalization Methods for Out-of-Band Nonlinearity Mitigation in Fiber-Optic Communications
Authors: Golani Ori , Feder Meir , Shtaif Mark
Published: February 2019

In recent years, it has been established that the adverse effects of nonlinear interference noise (NLIN) can be mitigated using adaptive equalization methods. As such, a wide variety of adaptive equalization methods have been used to treat nonlinearity, in different transmission scenarios. This paper reviews the principles of out-of-band nonlinearity mitigation using adaptive equalization. Statistical properties of NLIN that can be exploited for mitigation are discussed, as well as the cost and benefit of various types of equalizers. In particular we describe the equivalence between the NLIN and time-dependent inter-symbol-interference (ISI) and discuss ways in which the ISI coefficients can be characterized theoretically and experimentally. We further discuss the effectiveness of existing ISI mitigation algorithms, and explain the need for designing customized algorithms that take advantage of the various correlation properties characterizing the ISI coefficients. This paper is intended to be a practical reference for researchers who want to apply equalization algorithms or design new methods for nonlinearity mitigation.
Pressure Study on Pipe Transportation Associated with Cemented Coal Gangue Fly-Ash Backfill Slurry
Authors: Yang Jie , Yang Baogui , Yu Mingming
Published: February 2019

Cemented coal gangue-fly ash backfill (CGFB) slurry has commonly been used to control subsidence damage caused by underground coal mining. This paper discusses the characteristics of CGFB slurry fluidity in its pipe transportation. A general description about the components of the CGFB is provided involving the percentage of composition, particle size distribution (PSD) and rheological performance. The CGFB flow characteristics of the slurry pipeline were simulated in a straight pipe and 90° elbow pipe, respectively, combined with the pressure loss and conveying velocity distribution. With the help of the commercial computational fluid dynamic (CFD) code FLUENT, the modeling was conducted with various slurry feeding velocities. These results showed the local resistance loss in a bending pipe is significantly higher than the resistance in a straight pipe under the same conditions associated with CGFB transportation. The velocity distribution of the slurry solid particles in the slurry’s movement forward is more decentralized as the hydraulic inlet velocity increases. Based on these simulation data, a correlation was developed to predict the resistance loss of the CGFB slurry as a function of the hydraulic inlet velocity, pipe diameter and CGFB slurry rheological characteristics.
Enhanced Fouling Resistance and Antibacterial Properties of Novel Graphene Oxide-Arabic Gum Polyethersulfone Membranes
Authors: Najjar Ahmad , Sabri Souhir , Al-Gaashani Rashad , Kochkodan Viktor , Atieh Muataz Ali
Published: February 2019

Membrane biofouling has proved to be a major obstacle when it comes to membrane efficiency in membrane-based water treatment. Solutions to this problem remain elusive. This study presents novel polyethersulfone (PES) membranes that are fabricated using the phase inversion method at different loadings of graphene oxide (GO) and 1 wt. % arabic gum (AG) as nanofiller and pore forming agents. Synthesized GO was examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) for morphological studies and energy-dispersive X-ray spectroscopy (EDX) for elemental analysis. The prepared GO flakes showed a high content of oxygen-containing groups (~31%). The fabricated membranes were extensively characterized, including water contact angle analysis for hydrophilicity, zeta potential measurements for surface charge, SEM, total porosity and pore size measurements. The prepared membranes underwent fouling tests using bovine serum albumin (BSA) solutions and biofouling tests using model Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacterial suspensions as well as real treated sewage effluent (TSE). The results showed that the novel PES/GO membranes possessed strong hydrophilicity and negative surface charge with an increase in porosity, pore size and water flux. The PES/GO membranes exhibited superior antibacterial action against both Gram-positive and Gram-negative bacterial species, implicating PES membranes which incorporate GO and AG as novel membranes that are capable of high antibiofouling properties with high flux.
Modified Nonlocal Strain Gradient Elasticity for Nano-Rods and Application to Carbon Nanotubes
Authors: Barretta Raffaele , Čanadija Marko , Marotti de Sciarra Francesco
Published: February 2019

Nowadays, the modified nonlocal strain gradient theory provides a mathematically well-posed and technically reliable methodology to assess scale effects in inflected nano-structures. Such an approach is extended in this paper to investigate the extensional behavior of nano-rods. The considered integral elasticity model, involving axial force and strain fields, is conveniently shown to be equivalent to a nonlocal differential problem equipped with constitutive boundary conditions. Unlike treatments in the literature, no higher-order boundary conditions are required to close the nonlocal problem. Closed-form solutions of elastic nano-rods under selected loadings and kinematic boundary conditions are provided. As an innovative implication, Young’s moduli of Single-Walled Carbon Nanotubes (SWCNT) weare assessed and compared with predictions of Molecular Dynamics (MD). New benchmarks for numerical analyses were also detected.
The Effects of Textural Parameters of Zeolite and Silica Materials on the Protective and Functional Properties of Polymeric Nonwoven Composites
Authors: Brochocka Agnieszka , Nowak Aleksandra , Panek Rafał , Franus Wojciech
Published: February 2019

Zeolites are micro- and mesoporous aluminosilicate minerals (both natural and industrially produced) widely used as catalysts and sorbents in domestic and commercial water purification and separation technologies. Their ability to selectively adsorb gases (i.e., water vapor, carbon dioxide, and sulfur dioxide removal) from an air stream makes them suitable for applications in odor reducing media used in filtering facepiece respirators (FFRs). FFRs are multilayer products in which the most important role is played by high-performance melt-blown electret nonwovens modified with activated carbon to adsorb malodorous compounds. Replacing carbon sorbents with zeolites could increase the efficiency of odor abatement, thus alleviating work-related hazards for individuals exposed to malodorous substances with adverse effects on human well-being. The objective of the present work was to analyze the influence of the textural parameters of zeolite and mesoporous silica materials on the protective and functional properties of polymeric nonwoven composites containing them. In our experiments, the longest breakthrough time against ammonia vapor was found for a nonwoven composite containing the inorganic mesoporous silica material type MCM-41. It was also characterized by high filtration efficiency against aerosols with solid and liquid dispersed phases (97% and 99% for sodium chloride and paraffin oil mist, respectively) at an airflow resistance of approximately 330 Pa. In turn, the composites containing the molecular sieve (SM-zeolite ZSM-5) exhibited the longest breakthrough time for acetone and cyclohexane vapors at the maximum allowable concentrations of 235 ppm and 81 ppm, respectively. Basic filtration tests showed that the composite was 97% effective against both test aerosols at an airflow resistance of 283.5 Pa.
Comparative Study of Vortex-Induced Vibration of FRP Composite Risers with Large Length to Diameter Ratio Under Different Environmental Situations
Authors: Wang Chunguang , Ge Shiquan , Sun Mingyu , Jia Zhirong , Han Baomin
Published: February 2019

The increasing attraction of crude resources on the ocean floor leads to the development of risers, which are an indispensable component of an offshore oil and gas exploitation structure. High-grade steel is normally utilized for risers, however, fiber reinforced polymer (FRP) composite risers have become a feasible and economical alternative due to the desirable properties of the material. A comparative study of vortex-induced vibration (VIV) of FRP composite risers with two designed geometries were conducted and an X80 steel riser was used as the benchmark. The length to diameter ratios of all three risers were set to 100 and their VIV responses under different environmental situations, including the natural frequencies, global displacements, global stresses and the stress distributions in every composite layers, were obtained using computational fluid dynamics (CFD) simulation with coupled fluid–structure interaction. The VIV characteristics of both FRP composite risers and their distinction compared with that of steel risers were analyzed and discussed. From this paper, the dynamic characteristics in different environmental situations of VIV for FRP composite risers can be further understood.
Seasonal and Intra-Annual Patterns of Sedimentary Evolution in Tidal Flats Impacted by Laver Cultivation along the Central Jiangsu Coast, China
Authors: Lu Wanyun , Sun Jiaqi , Liu Yongxue , Liu Yongchao , Zhao Bingxue
Published: February 2019

Human activities such as the rapid development of marine aquaculture in the central Jiangsu coast have had a marked impact on the tidal flat morphology. This research focuses on characterizing the spatial expansion of laver cultivation and its influence on the sedimentary evolution of tidal flats in the central Jiangsu coast. First, seasonal digital elevation models (DEMs) were established using 160 satellite images with medium resolution. Then, laver aquaculture regions were extracted from 50 time-series satellite images to calculate the area and analyze the spatial distribution and expansion of these areas. Finally, seasonal and intra-annual sedimentary evolution patterns of both aquaculture and non-aquaculture regions were determined using the constructed DEMs. Our results show that aquaculture regions have gradually expanded to the north and peripheral domains of the entire sand ridge since 1999 and by 2013, the seaward margins of each sandbank developed into dense cultivation regions. Additionally, the aquaculture regions increased from 11.99 km2 to 295.28 km2. The seasonal sedimentary evolution patterns indicate that deposition occurs during the winter and erosion during the summer. Thus, the aquaculture regions experience deposition in certain elevation intervals during the laver growing period and in the non-growing period, alluvial elevation intervals in the aquaculture regions are eroded and erosive ones are deposited in order to maintain the balance between scouring and silting. The sedimentary evolution of each sandbank is heterogeneous due to their different locations and the difference in sediment transport. The intra-annual evolution pattern is characterized by deposition in the high tidal flats and erosion in low ones. Hydrodynamic conditions and laver cultivation dominate partial sedimentary evolution, which gradually shapes the beach surface.
Effect of Height Ratio and Mass Ratio on Structure—Soil—Structure Interaction of Two Structures Using Centrifugal Experiment
Authors: Ngo Van-Linh , Kim Jae-Min , Chang Soo-Hyuk , Lee Changho
Published: February 2019

In a megacity, structure response during an earthquake could be increased or decreased due to effects from neighboring structures, through structure-soil-structure interaction (SSSI). In the present study, a series of dynamic geotechnical centrifuge tests are carried out to investigate SSSI effects on responses of structure with various characteristics of mass, height, and natural frequency. Experimental observations are focused on the effects of the distance between two structures, type, and peak acceleration of input excitation. A period lengthening is observed in the soil-foundation-structure interaction (SFSI) effects of all structures. It is monitored that an increment in response of smaller structure and a decrement in response of larger structure, compared to isolated structure, due to SSSI effects. Unfavorable distance reveals that the most significant increment in response of S2 structure occurred at approximately one-fourth of wavelength transmitted from the vibrating adjacent structure. More severe SSSI effects are found under a lower input earthquake acceleration. It is found that both height and mass ratios, between two adjacent structures, are particular parameters on SSSI, resulting in increment or reduction of structure response.
Transient Liquid Phase Bonding of Copper Using Sn Coated Cu MWCNT Composite Powders for Power Electronics
Authors: Rajendran Sri Harini , Do Hyun Jung , Wook Sang Jeon , Jae Pil Jung
Published: February 2019

In this paper, a novel transient liquid phase bonding material was fabricated by consequent electroless plating of Cu and Sn on a multi-walled carbon nanotube (MWCNT). The resulting Sn-Cu-MWCNT composites were used to join the Cu interconnects at 260°C. After 8 min of reflow time, a complete transformation of Cu3Sn intermetallic compound (IMC) occurred, leaving a Cu/MWCNT-Cu3Sn /Cu joint capable of withstanding the high operating temperature. Due to flake-like morphology, the Sn-Cu-MWCNT composite particles were well packed with lesser voids. The shear strength of the Cu/Cu3Sn-MWCNT/Cu joint was measured as 35.3 MPa, thus exhibiting the scope for replacing conventional transient liquid phase (TLP) powders in the future.
Simulation and Evaluation on the Dynamic Performance of a Cryogenic Turbo-Based Reverse Brayton Refrigerator
Authors: Yang Shanju , Liu Zhan , Fu Bao
Published: February 2019

In this study, a cryogenic turbo-based refrigerator, with high-speed foil gas bearing turboexpander and plate-fin heat exchanger, was presented. For the cooling process of a cryogenic refrigerator is long and complex, the efficient simulation of the dynamic performance is vital for its evaluation and operation. It is difficult to achieve this purpose. Because the cryogenic refrigerator will go through great temperature changes, resulting in dynamic performances of components going to complexity. In this article, the turboexpander was simulated using CFX, and the matching models with expansion works of consumption and utilization were unified and modified. With numerical calculation of heat exchanger, the dynamic simulation model of the refrigerator was improved via MATLAB code. The calculation method of the required input energy of the refrigerator in cooling processes was proposed based on the simulation and integration. The energy efficiency and economy cost of the refrigerator were evaluated under different operation modes. The refrigerator with a motor was more stable than the one with a blower. The refrigerator was tested under different conditions, the results of which agreed well with simulation data. The simulation method is efficient to serve practical applications, improve energy efficiency and reduce costs.
The Fire and Smoke Model Evaluation Experiment—A Plan for Integrated, Large Fire–Atmosphere Field Campaigns
Authors: Prichard Susan , Larkin N. Sim , Ottmar Roger , French Nancy H.F. , Baker Kirk , Brown Tim , Clements Craig , Dickinson Matt , Hudak Andrew , Kochanski Adam , Linn Rod , Liu Yongqiang , Potter Brian , Mell William , Tanzer Danielle , Urbanski Shawn , Watts Adam
Published: February 2019

The Fire and Smoke Model Evaluation Experiment (FASMEE) is designed to collect integrated observations from large wildland fires and provide evaluation datasets for new models and operational systems. Wildland fire, smoke dispersion, and atmospheric chemistry models have become more sophisticated, and next-generation operational models will require evaluation datasets that are coordinated and comprehensive for their evaluation and advancement. Integrated measurements are required, including ground-based observations of fuels and fire behavior, estimates of fire-emitted heat and emissions fluxes, and observations of near-source micrometeorology, plume properties, smoke dispersion, and atmospheric chemistry. To address these requirements the FASMEE campaign design includes a study plan to guide the suite of required measurements in forested sites representative of many prescribed burning programs in the southeastern United States and increasingly common high-intensity fires in the western United States. Here we provide an overview of the proposed experiment and recommendations for key measurements. The FASMEE study provides a template for additional large-scale experimental campaigns to advance fire science and operational fire and smoke models.
Features of Urban Heat Island in Mountainous Chongqing from a Dense Surface Monitoring Network
Authors: Jiang Ping , Liu Xiaoran , Zhu Haonan , Li Yonghua
Published: February 2019

The spatial and temporal features of urban heat island (UHI) intensity in complex urban terrain are barely investigated. This study examines the UHI intensity variations in mountainous Chongqing using a dense surface monitoring network. The results show that the UHI intensity is closely related to underlying surfaces, and the strongest UHI intensity is confined around the central urban areas. The UHI intensity is most prominent at night and in warm season, and the magnitude could reach ~4.5 °C on summer night. Our quantitative analysis shows a profound contribution of urbanization level to UHI intensity both at night and in summer, with regression coefficient b = 4.31 and 6.65, respectively. At night, the urban extra heat such as reflections of longwave radiation by buildings and release of daytime-stored heat from artificial materials, is added into the boundary layer, which compensates part of urban heat loss and thus leads to stronger UHI intensity. In summer, the urban areas are frequently controlled by oppressively hot weather. Due to increased usage of air conditioning, more anthropogenic heat is released. As a result, the urban temperatures are higher at night. The near-surface wind speed can serve as an indicator predicting UHI intensity variations only in the diurnal cycle. The rural cooling rate during early evening transition, however, is an appropriate factor to estimate the magnitude of UHI intensity both at night and in summer.
Quasars: From the Physics of Line Formation to Cosmology
Authors: Marziani Paola , Bon Edi , Bon Natasa , del Olmo Ascension , Martínez-Aldama Mary Loli , D’Onofrio Mauro , Dultzin Deborah , Negrete C. Alenka , Stirpe Giovanna M.
Published: February 2019

Quasars accreting matter at very high rates (known as extreme Population A (xA) or super-Eddington accreting massive black holes) provide a new class of distance indicators covering cosmic epochs from the present-day Universe up to less than 1 Gyr from the Big Bang. The very high accretion rate makes it possible that massive black holes hosted in xA quasars can radiate at a stable, extreme luminosity-to-mass ratio. This in turn translates into stable physical and dynamical conditions of the mildly ionized gas in the quasar low-ionization line emitting region. In this contribution, we analyze the main optical and UV spectral properties of extreme Population A quasars that make them easily identifiable in large spectroscopic surveys at low- ( z ≲ 1 ) and intermediate-z (2 ≲ z ≲ 2.6), and the physical conditions that are derived for the formation of their emission lines. Ultimately, the analysis supports the possibility of identifying a virial broadening estimator from low-ionization line widths, and the conceptual validity of the redshift-independent luminosity estimates based on virial broadening for a known luminosity-to-mass ratio.
Oxygen Availability during Growth Modulates the Phytochemical Profile and the Chemo-Protective Properties of Spinach Juice
Authors: Milano Francesco , Mussi Francesca , Fornaciari Silvia , Altunoz Meltem , Forti Luca , Arru Laura , Buschini Annamaria
Published: February 2019

Fruits and vegetables are a good source of potentially biologically active compounds. Their regular consumption in the human diet can help reduce the risk of developing chronic diseases such as cardiovascular diseases and cancer. Plants produce additional chemical substances when subject to abiotic stress or infected by microorganisms. The phytochemical profile of spinach leaves (Spinacia oleracea L.), which is a vegetable with widely recognized health-promoting activity, has been affected by applying root hypoxic and re-oxygenation stress during plant growth. Leaf juice at different sampling times has been subject to liquid chromatography mass spectrometry (LC-MSn) analysis and tested on the human colorectal adenocarcinoma cell line HT29 by using the Comet assay. The cells were previously treated with H2O2 to simulate the presence of an oxidative stress (as in colon cancer condition) and the leaf juice application resulted in a significant antioxidant and protective in vitro effect. The duration of the hypoxic/re-oxygenation stress imposed on the plant reflects the antioxidant leaf juice content. After hypoxic stress (24 h) and reoxygenation (2 h), we show a decrease (50%) of the relative abundance of the principal identified antioxidant molecules but a higher antioxidant activity of the spinach juice on HT29 cells (20%). Data shows a complex relation between plant growing conditions and the modulation of secondary metabolites content in leaf juice that results in different chemo-protective activities in colon cancer cells.
Trends and Perspectives in Immunosensors for Determination of Currently-Used Pesticides: The Case of Glyphosate, Organophosphates, and Neonicotinoids
Authors: Reynoso Eduardo C. , Torres Eduardo , Bettazzi Francesca , Palchetti Ilaria
Published: February 2019

Pesticides, due to their intensive use and their peculiar chemical features, can persist in the environment and enter the trophic chain, thus representing an environmental risk for the ecosystems and human health. Although there are several robust and reliable standard analytical techniques for their monitoring, the high frequency of contamination caused by pesticides requires methods for massive monitoring campaigns that are capable of rapidly detecting these compounds in many samples of different origin. Immunosensors represent a potential tool for simple, rapid, and sensitive monitoring of pesticides. Antibodies coupled to electrochemical or optical transducers have resulted in effective detection devices. In this review, the new trends in immunosensor development and the application of immunosensors for the detection of pesticides of environmental concern—such as glyphosate, organophosphates, and neonicotinoids—are described.
Missed Diagnosis of Major Depressive Disorder with Catatonia Features
Authors: Jhawer Harry , Sidhu Meesha , Patel Rikinkumar S.
Published: February 2019

Catatonia is often a presentation of extreme anxiety and depression. Missing the diagnosis of catatonia would lead to improper treatment, which could be life-threatening. A thorough physical and psychiatric assessment is required for detecting the catatonic symptoms, especially, mutism and negativism in patients with depression. We discuss the case of a 58-year-old female that was incorrectly diagnosed and treated for major depressive disorder (MDD). The patient was then correctly diagnosed with MDD with catatonic features and improved once benzodiazepine (BZD) was started. The preferred BZD was lorazepam, with a success rate of complete remission of up to 80% in adults. Treatment was started with lorazepam 1–2 mg and improvement was seen within the first ten minutes. We believed the addition of BZD in a psychotropic regimen could improve both catatonia and depression, and should be continued for 3–6 months to prevent relapses and recurrences.
Potential Design of Seismic Vulnerable Buildings Incorporating Lead Rubber Bearing
Authors: Al-Kutti Walid A. , Islam A. B. M. Saiful
Published: February 2019

The seismic hazard of vulnerable regions warrants the investigation of new technologies, such as base level isolation by lead rubber bearing (LRB) devices, that can help to mitigate structural damage on seismic prone buildings. The behavior adopting such technologies can be dynamically observed in simulated environments and thus serves as a valuable metric for their feasibility. LRB base isolators were incorporated into the design of 16 model buildings to better understand how they affected a building’s seismic response while also providing information on the structural parameters. A total of 12 different types of bearing systems were tested in base isolated (BI) buildings against conventional fixed-base (FB) isolated buildings. The system of each model high-rise building was represented by the finite element package. Static as well as dynamic analysis were conducted using response spectrum analysis (RSA) based on the seismic excitation to determine the influence of the model type in the aseismic design and the alteration in superstructure behavior. The study reveals that the LRB isolators can potentially diminish respective story accelerations, story inertia, and base shear. Use of LRB isolators in BI buildings resulted in a 10–20% reduction in base shear compared to FB buildings. A notable lateral shift of superstructure is offered by LRB-induced flexibility. The reduction of story acceleration for response spectrum varies 30% on lower stories up to 70% on upper stories. The LRB systems with higher characteristic strength and relatively less isolation periods shows better productivity to minimize displacements in the bearing face for dropping structural shift. However, the LRB with comparatively lower characteristic strength and high isolation periods shows the most efficiency in controlling base shear, offering least story accelerations and consenting lower story inertia forces.
Performance Review of Prefabricated Building Systems and Future Research in Australia
Authors: Navaratnam Satheeskumar , Ngo Tuan , Gunawardena Tharaka , Henderson David
Published: February 2019

Volumetric prefabricated building construction is growing in most developed countries; for example, in Sweden the market share of prefabricated building systems in the housing industry was more than 80%. However, in Australia only approximately 3–4% of new building constructions are prefabricated buildings in a year. A major hindrance to the growth of prefab construction in Australia is that systems are developed under commercial and confidential conditions. There are limited publicly-available research and case studies for certifiers, regulators, engineers and academia to provide independent information on the performance, advantages and disadvantages of prefabricated building systems. Independent designers and structural engineers are relying on the strength of the structural and non-structural element, as well as the connections of the prefabricated building systems. This strength is estimated from the “commercial-in-confidence” test of individual components by manufactures, and it might result in undesired outcomes in design. This paper provides an overview of available literature on structural performance, benefits, constraints and challenges of prefabricated building systems. This paper also highlights the research needed on the prefabricated building systems such as full-scale tests, numerical modelling, hybrid simulations, case studies and social and economic assessments. Being supported by sound academic research will increase the market demand for prefabricated building systems in Australia as well as in other countries.
Study of the Seismic Response on the Infill Masonry Walls of a 15-Storey Reinforced Concrete Structure in Nepal
Authors: Furtado André , Vila-Pouca Nelson , Varum Humberto , Arêde António
Published: February 2019

Following the strong earthquake on April 25, 2015 in Nepal, a team from the University of Porto, in collaboration with other international institutions, made a field study on some of the most affected areas in the capital region of Kathmandu. One of the tasks was the study of a high-rise settle of buildings that were damaged following the earthquake sequence. A survey damage assessment was performed to a 15-storey infilled reinforced concrete structure, which will be detailed in the manuscript. Moreover, ambient vibration tests were carried out to determine the natural frequencies and corresponding vibration modes of the structure. The main aim of this manuscript is to present a numerical study concerning the influence of the masonry infill walls in the structure seismic response. For this, three numerical models were built discriminating the situations with and without damage and nondamaged infill walls. Validation and calibration of the numerical model was ensured by comparing the numerical frequencies with those obtained from ambient vibration tests. In addition, linear elastic analyses were carried out, using real accelerograms from the Gorkha earthquake to assess and quantify the major differences between the models in terms of inter-storey drifts ratios, inter-storey shear forces and seismic loadings.
Releasing the Immune System Brakes Using siRNAs Enhances Cancer Immunotherapy
Authors: Sioud Mouldy
Published: February 2019

Therapeutic dendritic cell (DC) cancer vaccines rely on the immune system to eradicate tumour cells. Although tumour antigen-specific T cell responses have been observed in most studies, clinical responses are fairly low, arguing for the need to improve the design of DC-based vaccines. The incorporation of small interfering RNAs (siRNAs) against immunosuppressive factors in the manufacturing process of DCs can turn the vaccine into potent immune stimulators. Additionally, siRNA modification of ex vivo-expanded T cells for adoptive immunotherapy enhanced their killing potency. Most of the siRNA-targeted immune inhibitory factors have been successful in that their blockade produced the strongest cytotoxic T cell responses in preclinical and clinical studies. Cancer patients treated with the siRNA-modified DC vaccines showed promising clinical benefits providing a strong rationale for further development of these immunogenic vaccine formulations. This review covers the progress in combining siRNAs with DC vaccines or T cell therapy to boost anti-tumour immunity.
The Challenge of Achieving a High Density of Fe-Based Active Sites in a Highly Graphitic Carbon Matrix
Authors: Li Jingkun , Jia Qingying , Mukerjee Sanjeev , Sougrati Moulay-Tahar , Drazic Goran , Zitolo Andrea , Jaouen Frédéric
Published: February 2019

As one of the most promising platinum group metal-free (PGM-free) catalysts for oxygen reduction reaction (ORR), Fe–N–C catalysts with a high density of FeNx moieties integrated in a highly graphitic carbon matrix with a proper porous structure have attracted extensive attention to combine the high activity, high stability and high accessibility of active sites. Herein, we investigated a ZnCl2/NaCl eutectic salts-assisted ionothermal carbonization method (ICM) to synthesize Fe–N–C catalysts with tailored porous structure, high specific surface area and a high degree of graphitization. However, it was found to be challenging to anchor a high density of FeNx sites onto highly graphitized carbon. Iron precursors with preexisting Fe–N coordination were required to form FeNx sites in the nitrogen-doped carbon with a high degree of graphitization, while individual Fe and N precursors led to a Fe–N–C catalyst with poor-ORR activity. This provides valuable insights into the synthesis-structure relationship. Moreover, the FeNx moieties were identified as the major active sites in acidic conditions, while both FeNx sites and Fe2O3 were found to be active in alkaline medium.
Advantageous Preparation of Digested Proteic Extracts from Spirulina platensis Biomass
Authors: Verdasco-Martín Carlos M. , Echevarrieta Lea , Otero Cristina
Published: February 2019

Spirulina biomass has great nutritional value, but its proteins are not as well adsorbed as animal ones are. New functional food ingredients and metabolites can be obtained from spirulina, using different selective biodegradations of its biomass. Four enzyme-assisted extraction methods were independently studied, and their best operation conditions were determined. Enzymes were employed to increase the yield of easily adsorbed proteic extracts. A biomass pre-treatment using Alcalase® (pH 6.5, 1% v/w, and 30 °C) is described, which increased the extraction yield of hydrophilic biocomponents by 90% w/w compared to the simple solvent extraction. Alcalase® gives rise to 2.5–6.1 times more amino acids than the others and eight differential short peptides (438–1493 Da). These processes were scaled up and the extracts were analyzed. Higher destruction of cell integrity in the case of Alcalase® was also visualized by transmission electron microscopy. The described extractive technology uses cheap, commercial, food grade enzymes and hexane, accepted for food and drug safety. It is a promising process for a competitive biofactory, thanks to an efficient production of extracts with high applied potential in the nutrition, cosmetic, and pharmaceutical industries.
Biofuel Synthesis from Sorbitol by Aqueous Phase Hydrodeoxygenation over Bifunctional Catalysts: In-depth Study of the Ru–Pt/SiO2–Al2O3 Catalytic System
Authors: Messou Davina , Vivier Laurence , Canaff Christine , Especel Catherine
Published: February 2019

The catalytic performances of Ru–Pt/SiO2–Al2O3 catalysts synthetized by three methods (co-impregnation (CI), successive impregnations (SI) and redox deposition (CR)) were compared for their sorbitol transformation to hexane under hydrothermal conditions. The existence of Pt–Ru interaction was demonstrated by TEM-EDX only on SI and CR samples, with a PtRu alloy suspected by XRD and XPS. The chemical nature of the Ru species differed according to the synthesis method with the presence of Ru4+ species on SI–(Ru–Pt) and CR catalysts. The SI–(Ru–Pt)/SiO2–Al2O3 system displayed the best metal–acid function balance leading to the highest selectivity to hexane. The study of the reactivity of isosorbide and 2,5-dimethylfuran intermediates highlighted that the first one was poorly reactive compared to the second one, and the latter was selectively convertible to hexane. The synergy effect on SI– (Ru–Pt)/SiO2–Al2O3 catalyst was attributed to the presence of small-sized bimetallic particles favoring an electronic exchange from Ru to Pt, and increasing the formation of 2,5-dimethylfuran.
Use of Zirconium Phosphate-Sulphate as Acid Catalyst for Synthesis of Glycerol-Based Fuel Additives
Authors: Testa Maria Luisa , La Parola Valeria , Mesrar Farah , Ouanji Fatiha , Kacimi Mohamed , Ziyad Mahfoud , Liotta Leonarda Francesca
Published: February 2019

In the present work, zirconium phosphates and mixed zirconium phosphate–sulphate acid catalysts have been investigated in the acetylation of glycerol in order to obtain acetins as fuel additives. The following catalysts with chemical composition, Zr3(PO4)4, Zr(SO4)2, Zr2(PO4)2SO4, Zr3(PO4)2(SO4)3 and Zr4(PO4)2(SO4)5 have been prepared and characterized by acid capacity measurements, BET, XRD, FT-IR, XPS. The surface chemical composition in terms of P/Zr and S/Zr atomic ratios was monitored in the fresh and used catalysts. Zr3(PO4)2(SO4)3 and Zr4(PO4)2(SO4)5 showed the highest acidity associated with the synergic effect of two main crystalline phases, Zr2(PO4)2SO4 and Zr(SO4)2·4H2O. The reactions of glycerol acetylation were carried out by using a mass ratio of catalyst/glycerol equal to 5 wt% and molar ratio acetic acid/glycerol equal to 3:1. The glycerol conversion versus time was investigated over all the prepared samples in order to identify the best performing catalysts. Over Zr3(PO4)2(SO4)3 and Zr4(PO4)2(SO4)5 full glycerol conversion was achieved in 1 h only. Slightly lower conversion values were registered for Zr3(PO4)4 and Zr2(PO4)2SO4, while Zr(SO4)2 was the worst catalyst. Zr4(PO4)2(SO4)5 was the most selective catalyst and was used for recycling experiments up to five cycles. Despite a modest loss of activity, a drastic decrease of selectivity to tri- and diacetin was observed already after the first cycle. This finding was attributed to the leaching of sulphate groups as detected by XPS analysis of the spent catalyst.
Microalgae Cultivation for the Biotransformation of Birch Wood Hydrolysate and Dairy Effluent
Authors: Lage Sandra , Kudahettige Nirupa P. , Ferro Lorenza , Matsakas Leonidas , Funk Christiane , Rova Ulrika , Gentili Francesco G.
Published: February 2019

In order to investigate environmentally sustainable sources of organic carbon and nutrients, four Nordic green microalgal strains, Chlorella sorokiniana, Chlorella saccharophila, Chlorella vulgaris, and Coelastrella sp., were grown on a wood (Silver birch, Betula pendula) hydrolysate and dairy effluent mixture. The biomass and lipid production were analysed under mixotrophic, as well as two-stage mixotrophic/heterotrophic regimes. Of all of the species, Coelastrella sp. produced the most total lipids per dry weight (~40%) in the mixture of birch hydrolysate and dairy effluent without requiring nutrient (nitrogen, phosphorus, and potassium—NPK) supplementation. Overall, in the absence of NPK, the two-stage mixotrophic/heterotrophic cultivation enhanced the lipid concentration, but reduced the amount of biomass. Culturing microalgae in integrated waste streams under mixotrophic growth regimes is a promising approach for sustainable biofuel production, especially in regions with large seasonal variation in daylight, like northern Sweden. To the best of our knowledge, this is the first report of using a mixture of wood hydrolysate and dairy effluent for the growth and lipid production of microalgae in the literature.
Experimental Clarification of the RWGS Reaction Effect in H2O/CO2 SOEC Co-Electrolysis Conditions
Authors: Ioannidou Evangelia , Neophytides Stylianos , Niakolas Dimitrios K.
Published: February 2019

In the present investigation, modified X-Ni/GDC electrodes (where X = Au, Mo, and Fe) are studied, in the form of half-electrolyte supported cells, for their performance in the RWGS through catalytic-kinetic measurements. The samples were tested at open circuit potential conditions in order to elucidate their catalytic activity towards the production of CO (rco), which is one of the products of the H2O/CO2 co-electrolysis reaction. Physicochemical characterization is also presented, in which the samples were examined in the form of powders and as half cells with BET, H2-TPR, Air-TPO and TGA re-oxidation measurements in the presence of H2O. In brief, it was found that the rate of the produced CO (rco) increases by increasing the operating temperature and the partial pressure of H2 in the reaction mixture. In addition, the first results revealed that Fe and Mo modification enhances the catalytic production of CO, since the 2wt% Fe-Ni/GDC and 3wt% Mo-Ni/GDC electrodes were proven to perform better compared to the other samples, in the whole studied temperature range (800–900 °C), reaching thermodynamic equilibrium. Furthermore, carbon formation was not detected.
Orientation Growth and Magnetic Properties of Electrochemical Deposited Nickel Nanowire Arrays
Authors: Yu Yanlong , Li Jinpeng , Wang Jun , Wu Xige , Yu Cuiyan , Xu Tao , Chang Bingdong , Sun Hongyu , Arandiyan Hamidreza
Published: February 2019

Highly ordered ferromagnetic metal nanowire arrays with preferred growth direction show potential applications in electronic and spintronic devices. In this work, by employing a porous anodic aluminum oxide template-assisted electrodeposition method, we successfully prepared Ni nanowire arrays. Importantly, the growth direction of Ni nanowire arrays can be controlled by varying the current densities. The crystalline and growth orientation of Ni nanowire arrays show effects on magnetic properties. Single-crystallinity Ni nanowires with [110] orientation show the best magnetic properties, including coercivity and squareness, along the parallel direction of the nanowire axis. The current preparation strategy can be used to obtain other nanowire arrays (such as metal, alloy, and semiconductor) with controlled growth direction in confined space, and is therefore of broad interest for different applications.
Rational Design of Chiral Selenium-π-Acid Catalysts
Authors: Krätzschmar Felix , Ortgies Stefan , Willing Robert Y. N. , Breder Alexander
Published: February 2019

A series of unprecedented chiral selenium-π-acid catalysts for the asymmetric, oxidative functionalization of alkenes has been developed. In total, eleven different chiral dihydrodiselenocine and (di-)alkoxyphenyl (di)selenide motifs have been synthesized in a concise, modal, and straightforward fashion. Commercially available, non-racemic alcohols have been predominantly used as chiral building blocks for the facile assembly of the selenium-π-acid catalysts. These species have been exemplarily applied to the enantioselective intermolecular imidation and intramolecular acyloxylation of two olefins using N-fluorobenzenesulfonimide (NFSI) and ambient air, respectively, as terminal oxidants. In part, the catalysts provide very good yields of up to 99% and enantiomeric ratios of up to 83.5:16.5 under aerobic conditions.
Palanquin-Like Cu4Na4 Silsesquioxane Synthesis (via Oxidation of 1,1-bis(Diphenylphosphino)methane), Structure and Catalytic Activity in Alkane or Alcohol Oxidation with Peroxides
Authors: Kulakova Alena N. , Khrustalev Victor N. , Zubavichus Yan V. , Shul’pina Lidia S. , Shubina Elena S. , Levitsky Mikhail M. , Ikonnikov Nikolay S. , Bilyachenko Alexey N. , Kozlov Yuriy N. , Shul'pin Georgiy B.
Published: February 2019

The self-assembly synthesis of copper-sodium phenylsilsesquioxane in the presence of 1,1-bis(diphenylphosphino)methane (dppm) results in an unprecedented cage-like product: [(PhSiO1,5)6]2[CuO]4[NaO0.5]4[dppmO2]2 1. The most intriguing feature of the complex 1 is the presence of two oxidized dppm species that act as additional O-ligands for sodium ions. Two cyclic phenylsiloxanolate (PhSiO1,5)6 ligands coordinate in a sandwich manner with the copper(II)-containing layer of the cage. The structure of 1 was established by X-ray diffraction analysis. Complex 1 was shown to be a very good catalyst in the oxidation of alkanes and alcohols with hydrogen peroxide or tert-butyl hydroperoxide in acetonitrile solution. Thus, cyclohexane (CyH), was transformed into cyclohexyl hydroperoxide (CyOOH), which could be easily reduced by PPh3 to afford stable cyclohexanol with a yield of 26% (turnover number (TON) = 240) based on the starting cyclohexane. 1-Phenylethanol was oxidized by tert-butyl hydroperoxide to give acetophenone in an almost quantitative yield. The selectivity parameters of the oxidation of normal and branched alkanes led to the conclusion that the peroxides H2O2 and tert-BuOOH, under the action of compound (1), decompose to generate the radicals HO• and tert-BuO• which attack the C-H bonds of the substrate.
Recent Insights into NCL Protein Function Using the Model Organism Dictyostelium discoideum
Authors: McLaren Meagan D. , Mathavarajah Sabateeshan , Huber Robert J.
Published: February 2019

The neuronal ceroid lipofuscinoses (NCLs) are a group of devastating neurological disorders that have a global distribution and affect people of all ages. Commonly known as Batten disease, this form of neurodegeneration is linked to mutations in 13 genetically distinct genes. The precise mechanisms underlying the disease are unknown, in large part due to our poor understanding of the functions of NCL proteins. The social amoeba Dictyostelium discoideum has proven to be an exceptional model organism for studying a wide range of neurological disorders, including the NCLs. The Dictyostelium genome contains homologs of 11 of the 13 NCL genes. Its life cycle, comprised of both single-cell and multicellular phases, provides an excellent system for studying the effects of NCL gene deficiency on conserved cellular and developmental processes. In this review, we highlight recent advances in NCL research using Dictyostelium as a biomedical model.
Diastereomeric Recognition of 5’,8-cyclo-2’-Deoxyadenosine Lesions by Human Poly(ADP-ribose) Polymerase 1 in a Biomimetic Model
Authors: Masi Annalisa , Sabbia Arianna , Ferreri Carla , Manoli Francesco , Lai Yanhao , Laverde Eduardo , Liu Yuan , Krokidis Marios G. , Chatgilialoglu Chryssostomos , Faraone Mennella Maria Rosaria
Published: February 2019

5’,8-Cyclo-2’-deoxyadenosine (cdA), in the 5’R and 5’Sdiastereomeric forms, are typical non strand-break oxidative DNA lesions, induced by hydroxyl radicals, with emerging importance as a molecular marker. These lesions are exclusively repaired by the nucleotide excision repair (NER) mechanism with a low efficiency, thus readily accumulating in the genome. Poly(ADP-ribose) polymerase1 (PARP1) acts as an early responder to DNA damage and plays a key role as a nick sensor in the maintenance of the integrity of the genome by recognizing nicked DNA. So far, it was unknown whether the two diastereomeric cdA lesions could induce specific PARP1 binding. Here, we provide the first evidence of PARP1 to selectively recognize the diastereomeric lesions of 5’S-cdA and 5’R-cdA in vitro as compared to deoxyadenosine in model DNA substrates (23-mers) by using circular dichroism, fluorescence spectroscopy, immunoblotting analysis, and gel mobility shift assay. Several features of the recognition of the damaged and undamaged oligonucleotides by PARP1 were characterized. Remarkably, PARP1 exhibits different affinities in binding to a double strand (ds) oligonucleotide, which incorporates cdA lesions in R and S diastereomeric form. In particular, PARP1 proved to bind oligonucleotides, including a 5’S-cdA, with a higher affinity constant for the 5’S lesion in a model of ds DNA than 5’R-cdA, showing different recognition patterns, also compared with undamaged dA. This new finding highlights the ability of PARP1 to recognize and differentiate the distorted DNA backbone in a biomimetic system caused by different diastereomeric forms of a cdA lesion.