bluuebunny/crossref_metadata_2025 huggingface dataset:
How to Boost the Activity of the Monolayer Pt Supported on TiC Catalysts for Oxygen Reduction Reaction: A Density Functional Theory Study
Authors: Zhu Hui , Liu Houyi , Yang Lei , Xiao Beibei
Published: May 2019

Developing the optimized electrocatalysts with high Pt utilization as well as the outstanding performance for the oxygen reduction reaction (ORR) has raised great attention. Herein, the effects of the interlayer ZrC, HfC, or TiN and the multilayer Pt shell on the adsorption ability and the catalytic activity of the TiC@Pt core-shell structures are systemically investigated by density functional theory (DFT) calculations. For the sandwich structures, the presence of TiN significantly enhances the adsorption ability of the Pt shell, leading to the deterioration of the activity whilst the negligible influence of the ZrC and HfC insertion results the comparable performance with respect to TiC@Pt1ML. In addition, increasing the thickness of the Pt shell reduces the oxyphilic capacity and then mitigates the OH poisoning. From the free energy plots, the superior activity of TiC@Pt2ML is identified in comparison with 1ML and 3ML Pt shell. Herein, the improved activity with its high Pt atomic utilization makes the potential TiC@Pt2ML electrocatalyst for the future fuel cells.
The α9α10 Nicotinic Acetylcholine Receptor Antagonist αO-Conotoxin GeXIVA[1,2] Alleviates and Reverses Chemotherapy-Induced Neuropathic Pain
Authors: Wang Huanbai , Li Xiaodan , Zhangsun Dongting , Yu Gang , Su Ruibin , Luo Sulan
Published: May 2019

Oxaliplatin is a third-generation platinum drug and is widely used as a first-line therapy for the treatment of colorectal cancer (CRC). However, a large number of patients receiving oxaliplatin develop dose-limiting painful neuropathy. Here, we report that αO-conotoxin GeXIVA[1,2], a highly potent and selective antagonist of the α9α10 nicotinic acetylcholine receptor (nAChR) subtype, can relieve and reverse oxaliplatin-induced mechanical and cold allodynia after single and repeated intramuscular (IM) injections in rats. Treatments were started at 4 days post oxaliplatin injection when neuropathic pain emerged and continued for 8 and 16 days. Cold score and mechanical paw withdrawal threshold (PWT) were detected by the acetone test and von Frey test respectively. GeXIVA[1,2] significantly relieved mechanical and cold allodynia in oxaliplatin-treated rats after a single injection. After repeated treatments, GeXIVA[1,2] produced a cumulative analgesic effect without tolerance and promoted recovery from neuropathic pain. Moreover, the long lasting analgesic effect of GeXIVA[1,2] on mechanical allodynia continued until day 10 after the termination of the 16-day repeated treatment procedure. On the contrary, GeXIVA[1,2] did not affect acute mechanical and thermal pain behaviors in normal rats after repeated injections detected by the von Frey test and tail flick test. GeXIVA[1,2] had no influence on rat hind limb grip strength and body weight after repeated treatments. These results indicate that αO-conotoxin GeXIVA[1,2] could provide a novel strategy to treat chemotherapy-induced neuropathic pain.
Culturable Diversity and Lipid Production Profile of Labyrinthulomycete Protists Isolated from Coastal Mangrove Habitats of China
Authors: Wang Qiuzhen , Ye Huike , Xie Yunxuan , He Yaodong , Sen Biswarup , Wang Guangyi
Published: May 2019

Labyrinthulomycete protists have gained significant attention in the recent past for their biotechnological importance. Yet, their lipid profiles are poorly described because only a few large-scale isolation attempts have been made so far. Here, we isolated more than 200 strains from mangrove habitats of China and characterized the molecular phylogeny and lipid accumulation potential of 71 strains. These strains were the closest relatives of six genera namely Aurantiochytrium, Botryochytrium, Parietichytrium, Schizochytrium, Thraustochytrium, and Labyrinthula. Docosahexaenoic acid (DHA) production of the top 15 strains ranged from 0.23 g/L to 1.14 g/L. Two labyrinthulid strains, GXBH-107 and GXBH-215, exhibited unprecedented high DHA production potential with content >10% of biomass. Among all strains, ZJWZ-7, identified as an Aurantiochytrium strain, exhibited the highest DHA production. Further optimization of culture conditions for strain ZJWZ-7 showed improved lipid production (1.66 g/L DHA and 1.68 g/L saturated fatty acids (SFAs)) with glycerol-malic-acid, peptone-yeast-extract, initial pH 7, 28 °C, and rotation rate 150 rpm. Besides, nitrogen source, initial pH, temperature, and rotation rate had significant effects on the cell biomass, DHA, and SFAs production. This study provides the identification and characterization of nearly six dozen thraustochytrids and labyrinthulids with high potential for lipid accumulation.
The Biosynthesis of Rare Homo-Amino Acid Containing Variants of Microcystin by a Benthic Cyanobacterium
Authors: Shishido Tânia Keiko , Jokela Jouni , Humisto Anu , Suurnäkki Suvi , Wahlsten Matti , Alvarenga Danillo O. , Sivonen Kaarina , Fewer David P.
Published: May 2019

Microcystins are a family of chemically diverse hepatotoxins produced by distantly related cyanobacteria and are potent inhibitors of eukaryotic protein phosphatases 1 and 2A. Here we provide evidence for the biosynthesis of rare variants of microcystin that contain a selection of homo-amino acids by the benthic cyanobacterium Phormidium sp. LP904c. This strain produces at least 16 microcystin chemical variants many of which contain homophenylalanine or homotyrosine. We retrieved the complete 54.2 kb microcystin (mcy) gene cluster from a draft genome assembly. Analysis of the substrate specificity of McyB1 and McyC adenylation domain binding pockets revealed divergent substrate specificity sequences, which could explain the activation of homo-amino acids which were present in 31% of the microcystins detected and included variants such as MC-LHty, MC-HphHty, MC-LHph and MC-HphHph. The mcy gene cluster did not encode enzymes for the synthesis of homo-amino acids but may instead activate homo-amino acids produced during the synthesis of anabaenopeptins. We observed the loss of microcystin during cultivation of a closely related strain, Phormidium sp. DVL1003c. This study increases the knowledge of benthic cyanobacterial strains that produce microcystin variants and broadens the structural diversity of known microcystins.
Insights into Red Sea Brine Pool Specialized Metabolism Gene Clusters Encoding Potential Metabolites for Biotechnological Applications and Extremophile Survival
Authors: Ziko Laila , Adel Mustafa , Malash Mohamed N. , Siam Rania
Published: May 2019

The recent rise in antibiotic and chemotherapeutic resistance necessitates the search for novel drugs. Potential therapeutics can be produced by specialized metabolism gene clusters (SMGCs). We mined for SMGCs in metagenomic samples from Atlantis II Deep, Discovery Deep and Kebrit Deep Red Sea brine pools. Shotgun sequence assembly and secondary metabolite analysis shell (antiSMASH) screening unraveled 2751 Red Sea brine SMGCs, pertaining to 28 classes. Predicted categorization of the SMGC products included those (1) commonly abundant in microbes (saccharides, fatty acids, aryl polyenes, acyl-homoserine lactones), (2) with antibacterial and/or anticancer effects (terpenes, ribosomal peptides, non-ribosomal peptides, polyketides, phosphonates) and (3) with miscellaneous roles conferring adaptation to the environment/special structure/unknown function (polyunsaturated fatty acids, ectoine, ladderane, others). Saccharide (80.49%) and putative (7.46%) SMGCs were the most abundant. Selected Red Sea brine pool sites had distinct SMGC profiles, e.g., for bacteriocins and ectoine. Top promising candidates, SMs with pharmaceutical applications, were addressed. Prolific SM-producing phyla (Proteobacteria, Actinobacteria, Cyanobacteria), were ubiquitously detected. Sites harboring the largest numbers of bacterial and archaeal phyla, had the most SMGCs. Our results suggest that the Red Sea brine niche constitutes a rich biological mine, with the predicted SMs aiding extremophile survival and adaptation.
Oceans as a Source of Immunotherapy
Authors: Ahmad Bilal , Shah Masaud , Choi Sangdun
Published: May 2019

Marine flora is taxonomically diverse, biologically active, and chemically unique. It is an excellent resource, which offers great opportunities for the discovery of new biopharmaceuticals such as immunomodulators and drugs targeting cancerous, inflammatory, microbial, and fungal diseases. The ability of some marine molecules to mediate specific inhibitory activities has been demonstrated in a range of cellular processes, including apoptosis, angiogenesis, and cell migration and adhesion. Immunomodulators have been shown to have significant therapeutic effects on immune-mediated diseases, but the search for safe and effective immunotherapies for other diseases such as sinusitis, atopic dermatitis, rheumatoid arthritis, asthma and allergies is ongoing. This review focuses on the marine-originated bioactive molecules with immunomodulatory potential, with a particular focus on the molecular mechanisms of specific agents with respect to their targets. It also addresses the commercial utilization of these compounds for possible drug improvement using metabolic engineering and genomics.
Effects of Sting Plant Extracts as Penetration Enhancers on Transdermal Delivery of Hypoglycemic Compounds
Authors: Fuh Yuh-Ming , Pham Dinh-Chuong , Weng Ching-Feng
Published: May 2019

Background and objectives: The percutaneous route is an interesting and inventive investigation field of drug delivery. However, it is challenging for drug molecules to pass through the skins surface, which is a characterized by its permeability barrier. The purpose of this study is to look at the effect of some penetration enhancers on in vivo permeation of insulin and insulin sensitizers (curcumin and rutin) through diabetes-induced mouse skin. Materials and Methods: Sting crude extracts of Dendrocnide meyeniana, Urtica thunbergiana Sieb. and Zucc, and Alocasia odora (Lodd.) Spach were used as the penetration enhancers. Mouse skin irritation was tested by smearing the enhancers for the measurements at different time points and the cell viability of the HaCaT human skin keratinocytes, which was determined by Trypan blue exclusion and MTT assays to evaluate human biosafety for these extracts after the mouse skin permeation experiments. Results: All enhancers induced a slight erythema without edema on the mouse skin that completely recovered after 6 h from the enhancer smears as compared with normal mouse skin. Furthermore, no damaged cells were found in the HaCaT keratinocytes under sting crude extract treatments. The blood sugar level in the diabetic mice treated with the insulin or insulin sensitizers, decreased significantly (p < 0.05) in the presence of enhancers. The area under the curve (AUC) values of transdermal drug delivery (TDD) ranged from 42,000 ± 5000 mg/dL x min without enhancers, to 30,000 ± 2000 mg/dL x min in the presence of enhancers. Conclusions: This study exhibited that natural plant extracts could be preferred over the chemically synthesized molecules and are safe and potent penetration enhancers for stimulating the transdermal absorption of drugs.
The Association of Cardiorespiratory Fitness on Memory Function: Systematic Review
Authors: Rigdon Brandon , Loprinzi Paul D.
Published: May 2019

Background and Objectives: Cardiorespiratory fitness is an important predictor of cardiovascular and cardiometabolic health. To extend our knowledge on the health effects associated with cardiorespiratory fitness, the objective of this study was to evaluate the association of cardiorespiratory fitness on memory function. Materials and Methods: Embase/PubMed, Web of Science, Google Scholar, Sports Discus, and PsychInfo databases were searched. Inclusionary criteria included: (1) were conducted among adult humans (18+ years), (2) evaluated cardiorespiratory fitness as the independent variable, (3) measured cardiorespiratory fitness with an objective device (e.g., indirect calorimetry), (4) evaluated memory function (any type) as the outcome measure, and (5) included either a cross-sectional, prospective, or experimental-study design. Information on the participant’s characteristics, study design, cardiorespiratory fitness assessment, memory type, whether the study statistically controlled for exercise behavior, and study results were extracted. The relationship between cardiorespiratory fitness and memory was synthesized while considering the data extraction parameters. Results: In total, 17 articles met the inclusionary criteria, including two prospective cohort studies and 15 cross-sectional studies. The main findings of this review are twofold: (1) across the 17 evaluated studies, 15 (88.2%) studies demonstrated some evidence of a positive association between cardiorespiratory fitness (CRF) and memory function, and (2) none of these 17 studies statistically controlled for physical activity behavior. Conclusion: CRF appears to be positively associated with memory function, however, it is uncertain as to whether this association occurs independently of physical activity or is mediated via physical activity behavior.
Nasal Chondrosarcoma of the Lower Lateral Cartilage
Authors: Tan Hannah B. , Rimmer Joanne
Published: May 2019

Head and neck chondrosarcomas are incredibly rare with documented cases arising from skull base, maxilla, larynx, and nasal septum. We present the first reported case of chondrosarcoma arising from the lower lateral cartilage of the nose treated with surgical resection and primary reconstruction.
Factors Associated with Atopic Dermatitis and Allergic Rhinitis among Residents of Two Municipal Areas in South Korea
Authors: Acharya Dilaram , Bajgain Bishnu Bahadur , Yoo Seok-Ju
Published: May 2019

Background and Objectives: The growing burden and deleterious health consequences of allergic diseases, especially of allergic rhinitis (AR) and atopic dermatitis (AD), in developed countries remains an important public health issue. The current study aimed to assess the prevalence and to identify the risk factors of atopic dermatitis and allergic rhinitis among residents of Pohang-Si and Yeongdeok-Gun, two municipal areas in South Korea. Materials and Methods: A cross-sectional study was conducted in both municipal areas between 12 November and 13 December 2017. A total of 302 subjects were recruited from 100 households (25 apartments and 25 houses in each municipality), by system extraction according to district code numbers. Data were collected using International Study of Asthma and Allergies in Childhood (ISAAC) Standard Questionnaires for children and a health questionnaire for adults. Risk factors were identified by multivariate logistic regression analysis. Results: Of the 302 study participants, 12.9% and 25.5% had AD and AR, respectively. The significant factors associated with AD by multivariate logistic regression analysis were age ≥19 years (aOR (adjusted odds ratio) 6.9; 95% CI (confidence interval) (2.9–16.37)), residence in Pohang-Si (aOR 2.5; 95% CI (1.18–5.53)), and family history of allergic disease (aOR 2.3; 95% CI (1.09–4.9)). Similarly, the significant factors associated with AR were male gender (aOR 2.3; 95% CI (1.24–4.42)), age ≥19 years (aOR 4.4; 95% CI (2.28–8.48)), residence in Pohang-Si (aOR 2.8; 95% CI (1.51–5.37)), and family history of allergic disease (aOR 6.7; 95% CI (3.50–12.82)). Conclusion: The present study shows that age ≥19 years, residence in Pohang-Si, and family history of allergic disease are risk factors for AD and AR, and that, additionally, male gender is a risk factor of AR. Understanding the risk factors of allergic diseases can aid the design and implementation of evidence-specific strategies to reduce the long-standing problems associated with allergic disease.
A Novel Method for Humidity-Dependent Through-Plane Impedance Measurement for Proton Conducting Polymer Membranes
Authors: Heimerdinger Patrick , Rosin Andreas , Danzer Michael , Gerdes Thorsten
Published: May 2019

In this study, we introduce a through-plane electrochemical measurement cell for proton conducting polymer membranes (PEM) with the ability to vary temperature and humidity. Model Nafion and 3M membranes, as well as anisotropic composite membranes, were used to compare through plane and in plane conductivity. Electrochemical impedance spectroscopy (EIS) was applied to evaluate the proton conductivity of bare proton exchange membranes. In the Nyquist plots, all membranes showed a straight line with an angle of 60–70 degrees to the Z’-axis. Equivalent circuit modeling and linear extrapolation of the impedance data were compared to extract the membrane resistance. System and cell parameters such as high frequency inductance, contact resistance and pressure, interfacial capacitance were observed and instrumentally minimized. Material-related effects, such as swelling of the membranes and indentation of the platinum mesh electrodes were examined thoroughly to receive a reliable through-plane conductivity. The received data for model Nafion and 3M membranes were in accordance with literature values for in-plane and through-plane conductivity of membrane electrode assemblies. Anisotropic composite membranes underlined the importance of a sophisticated measurement technique that is able to separate the in-plane and through-plane effects in polymer electrolytes.
The Interface Microstructure and Shear Strength of Sn2.5Ag0.7Cu0.1RExNi/Cu Solder Joints under Thermal-Cycle Loading
Authors: Cao Congcong , Zhang Keke , Shi Baojin , Wang Huigai , Zhao Di , Sun Mengmeng , Zhang Chao
Published: May 2019

The interface microstructure and shear strength of Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints under thermal-cycle loading were investigated with scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and physical and chemical tests. The results show that an intermetallic compound (IMC) layer of Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints evolved gradually from the scalloped into larger wavy forms with increasing number of thermal cycles. The roughness and average thickness of IMC increased with thermal-cycle loading. However, at longer thermal-cycle loading, the shear strength of the joints was reduced by about 40%. The fracture pathway of solder joints was initiated in the solder seam with ductile fracture mechanism and propagated to the solder seam/IMC layer with ductile-brittle mixed-type fracture mechanism, when the number of thermal cycles increased from 100 to 500 cycles. By adding 0.05 wt.% Ni, the growth of the joint interface IMC could be controlled, and the roughness and average thickness of the interfacial IMC layer reduced. As a result, the shear strength of joints is higher than those without Ni. When compared to joint without Ni, the roughness and average thickness of 0.05 wt.% Ni solder joint interface IMC layer reached the minimum after 500 thermal cycles. The shear strength of that joint was reduced to a minimum of 36.4% of the initial state, to a value of 18.2 MPa.
Gold Bioleaching from Printed Circuit Boards of Mobile Phones by Aspergillus niger in a Culture without Agitation and with Glucose as a Carbon Source
Authors: Argumedo-Delira Rosalba , Gómez-Martínez Mario J. , Soto Brenda Joan
Published: May 2019

Hydrometallurgical and pyrometallurgical processes to recover gold (Au) from cell-phone printed circuit boards (PCBs) have the disadvantage of generating corrosive residues and consuming a large amount of energy. Therefore, it is necessary to look for biological processes that have low energy consumption and are friendly to the environment. Among the biological alternatives for the recovery of Au from PCB is the use of cyanogenic bacteria and filamentous fungi in cultures with agitation. Considering that it is important to explore the response of microorganisms in cultures without agitation to reduce energy expenditure in the recovery of metals from PCB, the present investigation evaluated the capacity of Aspergillus niger MXPE6 and a fungal consortium to induce Au bioleaching from PCB in a culture medium with glucose as a carbon source and without agitation (pH 4.5). The results indicate that the treatments with PCB inoculated with the fungal consortium showed a considerable decrease in pH (2.8) in comparison with the treatments inoculated with A. niger MXPE6 (4.0). The fungal consortium showed a significantly higher Au bioleaching (56%) than A. niger MXPE6 (17%). Finally, the use of fungal consortia grown without agitation could be an alternative to recover metals from PCB, saving energy and material resources.
A Modified Johnson-Cook Model for Ferritic-Pearlitic Steel in Dynamic Strain Aging Regime
Authors: Moris Devotta Ashwin , Sivaprasad P. V. , Beno Tomas , Eynian Mahdi , Hjertig Kjell , Magnevall Martin , Lundblad Mikael
Published: May 2019

In this study, the flow stress behavior of ferritic-pearlitic steel (C45E steel) is investigated through isothermal compression testing at different strain rates (1 s−1, 5 s−1, and 60 s−1) and temperatures ranging from 200 to 700 °C. The stress-strain curves obtained from experimental testing were post-processed to obtain true stress-true plastic strain curves. To fit the experimental data to well-known material models, Johnson-Cook (J-C) model was investigated and found to have a poor fit. Analysis of the flow stress as a function of temperature and strain rate showed that among other deformation mechanisms dynamic strain aging mechanism was active between the temperature range 200 and 400 °C for varying strain rates and J-C model is unable to capture this phenomenon. This lead to the need to modify the J-C model for the material under investigation. Therefore, the original J-C model parameters A, B and n are modified using the polynomial equation to capture its dependence on temperature and strain rate. The results show the ability of the modified J-C model to describe the flow behavior satisfactorily while dynamic strain aging was operative.
Mathematical Modeling of Postcombustion in an Electric Arc Furnace (EAF)
Authors: Arzpeyma Niloofar , Ersson Mikael , Jönsson Pär G.
Published: May 2019

Numerical modeling was used to study the capability of postcombustion in an electric arc furnace (EAF) equipped with virtual lance burners. The CO flow rate at the molten bath surface was estimated using the off-gas data obtained close to the outlet of an EAF. Then, the effect of the secondary oxygen flow rate on postcombustion was studied. The results show a CO flow rate of 0.6 kg·s−1 and 0.8 kg·s−1 for operation modes of burner and burner + lancing. Increase of the secondary oxygen flow rates of 60% and 70% result in 17% and 7% increase in the postcombustion ratio (PCR) for the burner and burner lancing modes, respectively.
Anelastic Behavior of Small Dimensioned Aluminum
Authors: Campari Enrico Gianfranco , Amadori Stefano , Bonetti Ennio , Berti Raffaele , Montanari Roberto
Published: May 2019

In the present research, results are presented regarding the anelasticity of 99.999% pure aluminum thin films, either deposited on silica substrates or as free-standing sheets obtained by cold rolling. Mechanical Spectroscopy (MS) tests, namely measurements of dynamic modulus and damping vs. temperature, were performed using a vibrating reed analyzer under vacuum. The damping vs. temperature curves of deposited films exhibit two peaks which tend to merge into a single peak as the specimen thickness increases above 0.2 µm. The thermally activated anelastic relaxation processes observed on free-standing films are strongly dependent on film thickness, and below a critical value of about 20 µm two anelastic relaxation peaks can be observed; both their activation energy and relaxation strength are affected by film thickness. These results, together with those observed on bulk specimens, are indicative of specific dislocation and grain boundary dynamics, constrained by the critical values of the ratio of film thickness to grain size.
A Novel Method of Fabricating Al-V Intermetallic Alloy through Electrode Heating
Authors: Wan Heli , Xu Baoqiang , Li Lanjie , Yang Bin , Li Dongming , Dai Yongnian
Published: May 2019

A novel method was developed to produce AlV55 alloy through reducing impurities content and component segregation with electrode assisted heating technology. This new process synergistically integrates a few low-cost process techniques, including granulation, mixing, and electro-heating to produce AlV55 alloy. During the heating process, the CaO is used as an additive in the raw materials. The uniform of AlV55 alloy composition and low impurities content are effectively controlled by this process. The analysis results show that Si (0.13 wt%), Fe (0.22 wt%), N (0.007 wt%), C (0.078 wt%), and O (0.051 wt%) impurities in the AlV55 products were reduced, which met the commercial standard (TS/T 579-2014), and V content ranged from 57.5 to 58.5 wt% when the Al/V2O5 mass ratio was 0.94:1. This method can realize the controllability of the reaction process and is suitable for large-scale industrial production.
Screening for Preterm Birth: Potential for a Metabolomics Biomarker Panel
Authors: Considine Elizabeth C. , Khashan Ali S. , Kenny Louise C.
Published: May 2019

The aim of this preliminary study was to investigate the potential of maternal serum to provide metabolomic biomarker candidates for the prediction of spontaneous preterm birth (SPTB) in asymptomatic pregnant women at 15 and/or 20 weeks’ gestation. Metabolomics LC-MS datasets from serum samples at 15- and 20-weeks’ gestation from a cohort of approximately 50 cases (GA < 37 weeks) and 55 controls (GA > 41weeks) were analysed for candidate biomarkers predictive of SPTB. Lists of the top ranked candidate biomarkers from both multivariate and univariate analyses were produced. At the 20 weeks’ GA time-point these lists had high concordance with each other (85%). A subset of 4 of these features produce a biomarker panel that predicts SPTB with a partial Area Under the Curve (pAUC) of 12.2, a sensitivity of 87.8%, a specificity of 57.7% and a p-value of 0.0013 upon 10-fold cross validation using PanelomiX software. This biomarker panel contained mostly features from groups already associated in the literature with preterm birth and consisted of 4 features from the biological groups of “Bile Acids”, “Prostaglandins”, “Vitamin D and derivatives” and “Fatty Acids and Conjugates”.
Improved Algal Toxicity Test System for Robust Omics-Driven Mode-of-Action Discovery in Chlamydomonas reinhardtii
Authors: Schade Stefan , Butler Emma , Gutsell Steve , Hodges Geoff , Colbourne John K. , Viant Mark R.
Published: May 2019

Algae are key components of aquatic food chains. Consequently, they are internationally recognised test species for the environmental safety assessment of chemicals. However, existing algal toxicity test guidelines are not yet optimized to discover molecular modes of action, which require highly-replicated and carefully controlled experiments. Here, we set out to develop a robust, miniaturised and scalable Chlamydomonas reinhardtii toxicity testing approach tailored to meet these demands. We primarily investigated the benefits of synchronised cultures for molecular studies, and of exposure designs that restrict chemical volatilisation yet yield sufficient algal biomass for omics analyses. Flow cytometry and direct-infusion mass spectrometry metabolomics revealed significant and time-resolved changes in sample composition of synchronised cultures. Synchronised cultures in sealed glass vials achieved adequate growth rates at previously unachievably-high inoculation cell densities, with minimal pH drift and negligible chemical loss over 24-h exposures. Algal exposures to a volatile test compound (chlorobenzene) yielded relatively high reproducibility of metabolic phenotypes over experimental repeats. This experimental test system extends existing toxicity testing formats to allow highly-replicated, omics-driven, mode-of-action discovery.
The Health Promoting Bioactivities of Lactuca sativa can be Enhanced by Genetic Modulation of Plant Secondary Metabolites
Authors: Ismail Hammad , Gillespie Anna L. , Calderwood Danielle , Iqbal Haroon , Gallagher Colene , Chevallier Olivier P. , Elliott Christopher T. , Pan Xiaobei , Mirza Bushra , Green Brian D.
Published: May 2019

Plant secondary metabolites are protective dietary constituents and rol genes evidently increase the synthesis of these versatile phytochemicals. This study subjected a globally important vegetable, lettuce (Lactuca sativa) to a combination of untargeted metabolomics (LC-QTof-MS) and in vitro bioactivity assays. Specifically, we examined the differences between untransformed cultured lettuce (UnT), lettuce transformed with either rolABC (RA) or rolC (RC) and commercially grown (COM) lettuce. Of the 5333 metabolite features aligned, deconvoluted and quantified 3637, 1792 and 3737 significantly differed in RA, RC and COM, respectively, compared with UnT. In all cases the number of downregulated metabolites exceeded the number increased. In vitro bioactivity assays showed that RA and RC (but not COM) significantly improved the ability of L. sativa to inhibit α-glucosidase, inhibit dipeptidyl peptidase-4 (DPP-4) and stimulate GLP-1 secretion. We putatively identified 76 lettuce metabolites (sesquiterpene lactones, non-phenolic and phenolic compounds) some of which were altered by several thousand percent in RA and RC. Ferulic acid levels increased 3033–9777%, aminooxononanoic acid increased 1141–1803% and 2,3,5,4′tetrahydroxystilbene-2-O-β-d-glucoside increased 40,272–48,008%. Compound activities were confirmed using commercially obtained standards. In conclusion, rol gene transformation significantly alters the metabolome of L.sativa and enhances its antidiabetic properties. There is considerable potential to exploit rol genes to modulate secondary metabolite production for the development of novel functional foods. This investigation serves as a new paradigm whereby genetic manipulation, metabolomic analysis and bioactivity techniques can be combined to enable the discovery of novel natural bioactives and determine the functional significance of plant metabolites.
Surface Engineering of Carbon-Based Microelectrodes for High-Performance Microsupercapacitors
Authors: He Liang , Hong Tianjiao , Huang Yue , Xiong Biao , Hong Xufeng , Tahir Muhammad , Haider Waqas Ali , Han Yulai
Published: May 2019

In this research, the enhancement in electrochemical performance of pyrolyzed carbon microelectrodes by surface modification is investigated. For the proposed microfabrication process, pyrolyzed carbon microelectrodes with multi-walled carbon nanotubes (MWCNTs) on their surface are obtained by developing GM-1060 photoresist in mixture of propylene glycol methyl ether acetate (PGMEA) and CNTs, and following pyrolysis of a micropatterned photoresist. Polyvinyl alcohol (PVA)/H2SO4 electrolyte (1 M) was applied to assemble this carbon/CNT microelectrode-based all-solid-state microsupercapacitor (carbon/CNT-MSC). The carbon/CNT-MSC shows a higher electrochemical performance compared with that of pyrolyzed carbon microelectrode-based MSC (carbon-MSC). The specific areal and volumetric capacitances of carbon/CNT-MSC (4.80 mF/cm2 and 32.0 F/cm3) are higher than those of carbon-MSC (3.52 mF/cm2 and 23.4 F/cm3) at the scan rate of 10 mV/s. In addition, higher energy density and power density of carbon/CNT-MSC (2.85 mWh/cm3 and 1.98 W/cm3) than those of carbon-MSC (2.08 mWh/cm3 and 1.41 W/cm3) were also achieved. This facile surface modification and optimization are potentially promising, being highly compatible with modern microfabrication technologies and allowing integration of highly electrically conductive CNTs into pyrolyzed carbon to assemble MSCs with improved electrochemical performance. Moreover, this method can be potentially applied to other high-performance micro/nanostructures and microdevices/systems.
A Stripline-Based Planar Wideband Feed for High-Gain Antennas with Partially Reflecting Superstructure
Authors: Baba Affan , Hashmi Raheel , Asadnia Mohsen , Matekovits Ladislau , Esselle Karu
Published: May 2019

This paper presents a new planar feeding structure for wideband resonant-cavity antennas (RCAs). The feeding structure consists of two stacked dielectric slabs with an air-gap in between. A U-shaped slot, etched in the top metal-cladding over the upper dielectric slab, is fed by a planar stripline printed on the back side of the dielectric slab. The lower dielectric slab backed by a ground plane, is used to reduce back radiation. To validate the wideband performance of the new structure, in an RCA configuration, it was integrated with a wideband all-dielectric single-layer partially reflecting superstructure (PRS) with a transverse permittivity gradient (TPG). The single-layer RCA fed by the U-slot feeding structure demonstrated a peak directivity of 18.5 dBi with a 3 dB directivity bandwidth of 32%. An RCA prototype was fabricated and experimental results are presented.
Self-Learning Microfluidic Platform for Single-Cell Imaging and Classification in Flow
Authors: Constantinou Iordania , Jendrusch Michael , Aspert Théo , Görlitz Frederik , Schulze André , Charvin Gilles , Knop Michael
Published: May 2019

Single-cell analysis commonly requires the confinement of cell suspensions in an analysis chamber or the precise positioning of single cells in small channels. Hydrodynamic flow focusing has been broadly utilized to achieve stream confinement in microchannels for such applications. As imaging flow cytometry gains popularity, the need for imaging-compatible microfluidic devices that allow for precise confinement of single cells in small volumes becomes increasingly important. At the same time, high-throughput single-cell imaging of cell populations produces vast amounts of complex data, which gives rise to the need for versatile algorithms for image analysis. In this work, we present a microfluidics-based platform for single-cell imaging in-flow and subsequent image analysis using variational autoencoders for unsupervised characterization of cellular mixtures. We use simple and robust Y-shaped microfluidic devices and demonstrate precise 3D particle confinement towards the microscope slide for high-resolution imaging. To demonstrate applicability, we use these devices to confine heterogeneous mixtures of yeast species, brightfield-image them in-flow and demonstrate fully unsupervised, as well as few-shot classification of single-cell images with 88% accuracy.
Experimental and Numerical Investigations on the Flow Characteristics within Hydrodynamic Entrance Regions in Microchannels
Authors: Li Haiwang , Huang Binghuan , Wu Min
Published: May 2019

Flow characteristics within entrance regions in microchannels are important due to their effect on heat and mass transfer. However, relevant research is limited and some conclusions are controversial. In order to reveal flow characteristics within entrance regions and to provide empiric correlation estimating hydrodynamic entrance length, experimental and numerical investigations were conducted in microchannels with square cross-sections. The inlet configuration was elaborately designed in a more common pattern for microdevices to diminish errors caused by separation flow near the inlet and fabrication faults so that conclusions which were more applicable to microchannels could be drawn. Three different microchannels with hydraulic diameters of 100 μm, 150 μm, and 200 μm were investigated with Reynolds (Re) number ranging from 0.5 to 50. For the experiment, deionized water was chosen as the working fluid and microscopic particle image velocimetry (micro-PIV) was adopted to record and analyze velocity profiles. For numerical simulation, the test-sections were modeled and incompressible laminar Navier–Stokes equations were solved with commercial software. Strong agreement was achieved between the experimental data and the simulated data. According to the results of both the experiments and the simulations, new correlations were proposed to estimate entrance length. Re numbers ranging from 12.5 to 15 was considered as the transition region where the relationship between entrance length and Re number converted. For the microchannels and the Reynolds number range investigated compared with correlations for conventional channels, noticeable deviation was observed for lower Re numbers (Re < 12.5) and strong agreement was found for higher Re numbers (Re > 15).
Tangential Flow Microfiltration for Viral Separation and Concentration
Authors: Wang Yi , Keller Keely , Cheng Xuanhong
Published: May 2019

Microfluidic devices that allow biological particle separation and concentration have found wide applications in medical diagnosis. Here we present a viral separation polydimethylsiloxane (PDMS) device that combines tangential flow microfiltration and affinity capture to enrich HIV virus in a single flow-through fashion. The set-up contains a filtration device and a tandem resistance channel. The filtration device consists of two parallel flow channels separated by a polycarbonate nanoporous membrane. The resistance channel, with dimensions design-guided by COMSOL simulation, controls flow permeation through the membrane in the filtration device. A flow-dependent viral capture efficiency is observed, which likely reflects the interplay of several processes, including specific binding of target virus, physical deposition of non-specific particles, and membrane cleaning by shear flow. At the optimal flow rate, nearly 100% of viral particles in the permeate are captured on the membrane with various input viral concentrations. With its easy operation and consistent performance, this microfluidic device provides a potential solution for HIV sample preparation in resource-limited settings.
Epitaxy of III-Nitrides on β-Ga2O3 and Its Vertical Structure LEDs
Authors: Li Weijiang , Zhang Xiang , Meng Ruilin , Yan Jianchang , Wang Junxi , Li Jinmin , Wei Tongbo
Published: May 2019

β-Ga2O3, characterized with high n-type conductivity, little lattice mismatch with III-Nitrides, high transparency (>80%) in blue, and UVA (400–320 nm) as well as UVB (320–280 nm) regions, has great potential as the substrate for vertical structure blue and especially ultra violet LEDs (light emitting diodes). Large efforts have been made to improve the quality of III-Nitrides epilayers on β-Ga2O3. Furthermore, the fabrication of vertical blue LEDs has been preliminarily realized with the best result that output power reaches to 4.82 W (under a current of 10 A) and internal quantum efficiency (IQE) exceeds 78% by different groups, respectively, while there is nearly no demonstration of UV-LEDs on β-Ga2O3. In this review, with the perspective from materials to devices, we first describe the basic properties, growth method, as well as doping of β-Ga2O3, then introduce in detail the progress in growth of GaN on (1 0 0) and (−2 0 1) β-Ga2O3, followed by the epitaxy of AlGaN on gallium oxide. Finally, the advances in fabrication and performance of vertical structure LED (VLED) are presented.
Molecular Modeling of Interactions between N-(Carboxymethyl)-N-tetradecylglycine and Fluorapatite
Authors: Nan Nan , Zhu Yimin , Han Yuexin , Liu Jie
Published: May 2019

In this study, a flotation collector N-(carboxymethyl)-N-tetradecylglycine (NCNT) was introduced for the purpose of energy-saving, and its adsorption ability on a fluorapatite (001) surface was investigated by density functional theory calculation. The results of frontier molecular orbital analysis of NCNT and adsorption energy between NCNT and fluorapatite (FAp) showed that NCNT possessed better activity and stronger interactions in the reagent–FAp system than oleic acid (OA). A simulation model revealed that the adsorption positions of NCNT on the fluorapatite surface are calcium atoms, at which NCNT chemisorbed on (001) fluorapatite surface via a bidentate geometry involving the formation of two Ca–O bonds. Flotation experiments verified that NCNT had a good recovery of 92.27% on FAp at pH 3.5, which was slightly lower than OA. Moreover, NCNT was used at 16 °C, which was much lower than the OA’s service condition (25 °C).
Application of Red Mud in Wastewater Treatment
Authors: Wang Li , Hu Guangyan , Lyu Fei , Yue Tong , Tang Honghu , Han Haisheng , Yang Yue , Liu Runqing , Sun Wei
Published: May 2019

Red mud (RM) is an industrial waste produced in large amounts during alumina extraction from bauxite. Its disposal generates serious environmental pollution due to high alkalinity. Therefore, a strategy for the effective utilization of RM must be developed. For instance, RM may be transformed into useful products, such as adsorbents. Given its high concentrations of aluminum oxides, iron oxides, titanium oxides, silica oxides, and hydroxides, RM may be developed as a cheap adsorbent for the removal of various ions from aqueous solution and soils (e.g., metal and non-metal ions, phenolic compounds, and dyes) and waste gas purification (sulfide and carbide). This review summarizes the background, properties, and applications of RM as an adsorbent. Proper approaches of removing metal and non-metal elements from wastewater are also systematically reviewed and compared. Emphasis is placed on the surface modification of RM to obtain high adsorption. Finally, the scope for future research in this area for RM is discussed in depth.
Re-Thinking Mining Waste through an Integrative Approach Led by Circular Economy Aspirations
Authors: Tayebi-Khorami Maedeh , Edraki Mansour , Corder Glen , Golev Artem
Published: May 2019

Mining wastes, particularly in the form of waste rocks and tailings, can have major social and environmental impacts. There is a need for comprehensive long-term strategies for transforming the mining industry to move toward zero environmental footprint. “How can the mining industry create new economic value, minimise its social and environmental impacts and diminish liability from mining waste?” This would require cross-disciplinary skills, across the social, environmental, technical, legal, regulatory, and economic domains, to produce innovative solutions. The aim of this paper is to review the current knowledge across these domains and integrate them in a new approach for exploiting or “re-thinking” mining wastes. This approach includes five key areas of social dimensions, geoenvironmental aspects, geometallurgy specifications, economic drivers and legal implications for improved environmental outcomes, and circular economy aspirations, which are aligned with the 10 principles of the International Council on Mining and Metals (ICMM). Applying circular economy thinking to mining waste presents a major opportunity to reduce the liability and increase the value of waste materials arising from mining and processing operations.
Research on the Adsorption Behavior of Heavy Metal Ions by Porous Material Prepared with Silicate Tailings
Authors: Ouyang Dongxiao , Zhuo Yuting , Hu Liang , Zeng Qiang , Hu Yuehua , He Zhiguo
Published: May 2019

Tailings generated from mineral processing have attracted worldwide concerns due to creating serious environmental pollution. In this work, porous adsorbents were prepared as a porous block by using silicate tailings, which can adsorb heavy metal ions from the solution and are easy to separate. The synthesized silicate porous material (SPM) was characterized by X-ray diffraction (XRD), Brunner–Emmet–Teller (BET), and scanning electron microscope (SEM). The material presented a surface area of 3.40 m2⸱g−1, a porosity of 54%, and the compressive strength of 0.6 MPa. The maximum adsorption capacities of Pb2+, Cd2+, and Cu2+ by SPM were 44.83 mg·g−1, 35.36 mg·g−1, and 32.26 mg·g−1, respectively. The experimental data were fitted well by the Freundlich and Langmuir adsorption models. The kinetics of the adsorption process were fitted well by the pseudo-first order kinetic equation. These results show that the porous materials prepared with silicate tailings could act as an effective and low-cost adsorbent for the removal of heavy metal ions from wastewater. This study may provide a new thought on the high-value utilization of tailing for alleviating environmental pressure.
Slags as Evidence for Copper Mining above Casaccia, Val Bregaglia (Central Alps)
Authors: Wenk Hans-Rudolf , Yu Rong , Tamura Nobumichi , Bischoff Duri , Hunkeler Walter
Published: May 2019

Slags from the remote Mota Farun locality above Casaccia (Val Bregaglia, Swiss Alps) have been analyzed with scanning electron microscopy, X-ray powder diffraction and microfocus synchrotron X-ray diffraction to determine mineralogical composition and microstructures. Non-magnetic slag samples are largely composed of euhedral and dendritic iron-rich olivine in a glassy matrix. Locally there are zones with globular inclusions rich in bornite ((Cu5Fe)S4) and locally metallic copper. Some regions display dendritic pentlandite ((Fe,Ni)9S8). Magnetic samples are mainly composed of fayalite (Fe2SiO4) and wüstite (FeO), with minor magnetite (Fe3O4). The mineralogical composition indicates that slags were the product of copper smelting. The slag compositions and morphologies are analogous to slags described from the Oberhalbstein (Graubünden, Switzerland) and the Trentino Alps (Italy) which are attributed to metallurgical exploitations of the Late Bronze Age. While the origin of the ore could not be determined, it may be related to ore deposits of chalcopyrite in greenschists and serpentinites in the vicinity, such as Alp Tgavretga (Septimer Pass) and Val Perossa (Val Bregaglia).
Geochemistry, Zircon U–Pb Geochronology, and Lu–Hf Isotopes of the Chishan Alkaline Complex, Western Shandong, China
Authors: Wei Pengfei , Yu Xuefeng , Li Dapeng , Liu Qiang , Yu Lidong , Li Zengsheng , Geng Ke , Zhang Yan , Sun Yuqin , Chi Naijie
Published: May 2019

Mass alkaline magmatic activities in Western Shandong during the late Mesozoic controlled the mineralization processes of gold and rare earth element (REE) polymetallic deposits in the region. The Chishan alkaline complex is closely associated with the mineralization of the Chishan REE deposit, which, as the third largest light REE deposit in China following the Baiyenebo (Inner Mongolia) and Mianning (Sichuan) deposits, is considered a typical example of alkaline rock mineralization throughout the North China Craton. To determine how the Chishan alkaline complex and REE deposit interact with each other, a systematic study was conducted on the petrology, rock geochemistry, zircon U–Pb geochronology, Lu–Hf isotopes of the quartz syenite, and alkali granite contained in the Chishan alkaline complex. The results reveal that the deposits feature similar geochemical characteristics typical of an alkaline rock series—both are rich in alkali, high in potassium, metaluminous, and poor in Ti, Fe, Mg, and Mn. In terms of REEs, the deposits are strongly rich in light REEs but poor in heavy REEs, with weak negative Eu anomalies. In terms of trace elements, they are rich in large ion lithophile elements Ba, Sr, and Rb but poor in high field-strength elements Nb, Ta, and Hf. Zircon LA-ICP-MS U–Pb dating indicated that the quartz syenite and alkali granite formed in Early Cretaceous at 125.8 ± 1.2 Ma and 127.3 ± 1.0 Ma, respectively; their εHf(t) values are −22.67 to −13.19, with depleted model ages (TDM) ranging from 1296 Ma to 1675 Ma and crustal model ages (TDMC) of 2036–2617 Ma. The Chishan alkaline complex originated from partial of the EM I-type (enriched mantle I) lithospheric mantle with assimilation of ancient crustal materials. The complex is of the same origin as the REE deposit, and developed in an extensional setting that resulted from plate subduction and lithospheric thinning and upwelling in the eastern area of the North China Craton.