bluuebunny/crossref_metadata_2025 huggingface dataset:
The Deformation Behavior, Microstructural Mechanism, and Process Optimization of PM/Wrought Dual Superalloys for Manufacturing the Dual-Property Turbine Disc
Authors: Zhang Baoyun , Liu Xiaoming , Yang Hao , Ning Yongquan
Published: October 2019

With the rapid development of modern aviation industry, dual-property turbine disc with fine comprehensive performance plays an important role in raising the thrust-to-weight ratio of the aero-engine. For manufacturing dual-property turbine disc, the powder metallurgy superalloy (PM) with excellent creep resistance was chosen as rim material, and the wrought superalloy with fine equiaxed grains was chosen as bore material. Electron beam welding was carried out on the PM/wrought dual superalloys. Hot compression tests were conducted on the PM/Wrought dual superalloys at temperatures of 1020–1140 °C and strain rates of 0.001–1.0 s−1. Deformation behavior and microstructure evolution have been investigated to study the deformation and recrystallization mechanism during hot deformation process. The results showed that PM/Wrought dual superalloy presents the similar flow behavior to single alloys and flow stress decreases significantly with the increase of deformation temperature or the decrease of strain rate. The apparent activation energy of deformation at the strain of 0.2 was determined as being 780.07 kJ·mol−1. The constitutive equation was constructed for modeling the hot deformation of PM/Wrought dual superalloy. Meanwhile, the processing map approach was further adopted to optimize the manufacturing process for the dual-property turbine disc. Additionally, a new instability criterion was proposed: the “cliff” and “valley” in the power dissipation map are determined as sufficient conditions for flow instability. The optimum processing parameter for manufacturing the PM/Wrought dual-property turbine disc can be obtained to enhance the mechanical properties, based on the analysis of processing map technology and microstructural mechanism.
Influence of Dietary Ingredients on Lean Body Percent, Uremic Toxin Concentrations, and Kidney Function in Senior-Adult Cats
Authors: Hall Jean A. , Jackson Matthew I. , Farace Giosi , Yerramilli Maha , Jewell Dennis E.
Published: October 2019

The goal of this study was to determine if modification of currently available maintenance foods with alternative ingredients, botanicals (fruit and vegetables), and increased amounts of functional lipids (fish oil) would delay the age-associated decline in glomerular filtration rate (GFR) and lean body mass (LBM) in senior-adult cats. Forty-four healthy cats (mean age, 12.2 years; range 10.7 to 14.0 years) were fed one of three foods (n = 14 or 15 per group) for six months: control food with 32.6% protein (as fed), or control food supplemented with increasing amounts of functional food bioactives: fish oil, fruit and vegetables, different protein sources, and <32.0% protein [functional foods one (FF1) and two (FF2)]. Senior-adult cats were compared before and after the feeding trial with 20 young-adult cats (mean age, 3.5 years; range 2.1 to 4.9 years). Compared with younger cats, older cats had decreased lean-body percent and serum albumin concentrations. Feeding FF1 and FF2 for six months increased lean-body percent, maintained serum albumin concentrations, increased GFR, decreased serum symmetric dimethylarginine (SDMA) concentrations, and decreased concentrations of the uremic toxin 3-indoxyl sulfate. These dietary changes may assist in offsetting sarcopenia and the chronic inflammation associated with aging in senior-adult cats.
Investigating the Protective Effect of Gross Saponins of Tribulus terrestris Fruit against Ischemic Stroke in Rat Using Metabolomics and Network Pharmacology
Authors: Wang Yang , Guo Wenjun , Liu Yue , Wang Jifeng , Fan Meiling , Zhao Hongyu , Xie Shengxu , Xu Yajuan
Published: October 2019

Stroke is one of the leading causes of death and long-term disability worldwide. Gross saponins of Tribulus terrestris fruit (GSTTF) has been used for neuroprotective therapy on convalescents of ischemic stroke. But the related therapeutic mechanisms have not yet been well investigated. This study aimed to investigate the protective effects of GSTTF on ischemic stroke using metabolomics coupled with network pharmacology analysis. The rat urine sample was collected and profiled by an LC-MS-based metabolomics approach. The pathway analysis was performed based on the highlighted biomarkers, then the network pharmacology approach was applied to screen the potential therapeutic targets of GSTTF. Metabolomics analysis showed that a series of metabolic perturbations occurred in the middle cerebral artery occlusion (MCAO) group compared with the sham group. Gross saponins of Tribulus terrestris fruit can change the MCAO-induced urine metabolic deviations in a reverse manner via regulating multiple metabolic pathways. Two proteins, inducible nitric oxide synthase (NOS2) and glycogen synthase kinase-3 beta (GSK3B), were highlighted by the network pharmacology analysis, which may be the potential therapeutic targets for the GSTTF against ischemic stroke. This study provides an overview of the mechanism of MCAO-induced ischemic stroke and investigates the efficacy of GSTTF in the treatment of ischemic stroke. Further study is needed to reveal its underlying mechanisms more clearly.
Characterization of Lipid Profiles after Dietary Intake of Polyunsaturated Fatty Acids Using Integrated Untargeted and Targeted Lipidomics
Authors: Naoe Satoko , Tsugawa Hiroshi , Takahashi Mikiko , Ikeda Kazutaka , Arita Makoto
Published: October 2019

Illuminating the comprehensive lipid profiles after dietary supplementation of polyunsaturated fatty acids (PUFAs) is crucial to revealing the tissue distribution of PUFAs in living organisms, as well as to providing novel insights into lipid metabolism. Here, we performed lipidomic analyses on mouse plasma and nine tissues, including the liver, kidney, brain, white adipose, heart, lung, small intestine, skeletal muscle, and spleen, with the dietary intake conditions of arachidonic acid (ARA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) as the ethyl ester form. We incorporated targeted and untargeted approaches for profiling oxylipins and complex lipids such as glycerol (phospho) lipids, sphingolipids, and sterols, respectively, which led to the characterization of 1026 lipid molecules from the mouse tissues. The lipidomic analysis indicated that the intake of PUFAs strongly impacted the lipid profiles of metabolic organs such as the liver and kidney, while causing less impact on the brain. Moreover, we revealed a unique lipid modulation in most tissues, where phospholipids containing linoleic acid were significantly decreased in mice on the ARA-supplemented diet, and bis(monoacylglycero)phosphate (BMP) selectively incorporated DHA over ARA and EPA. We comprehensively studied the lipid profiles after dietary intake of PUFAs, which gives insight into lipid metabolism and nutrition research on PUFA supplementation.
Inborn Errors of Metabolism in the Era of Untargeted Metabolomics and Lipidomics
Authors: Ismail Israa T , Showalter Megan R , Fiehn Oliver
Published: October 2019

Inborn errors of metabolism (IEMs) are a group of inherited diseases with variable incidences. IEMs are caused by disrupting enzyme activities in specific metabolic pathways by genetic mutations, either directly or indirectly by cofactor deficiencies, causing altered levels of compounds associated with these pathways. While IEMs may present with multiple overlapping symptoms and metabolites, early and accurate diagnosis of IEMs is critical for the long-term health of affected subjects. The prevalence of IEMs differs between countries, likely because different IEM classifications and IEM screening methods are used. Currently, newborn screening programs exclusively use targeted metabolic assays that focus on limited panels of compounds for selected IEM diseases. Such targeted approaches face the problem of false negative and false positive diagnoses that could be overcome if metabolic screening adopted analyses of a broader range of analytes. Hence, we here review the prospects of using untargeted metabolomics for IEM screening. Untargeted metabolomics and lipidomics do not rely on predefined target lists and can detect as many metabolites as possible in a sample, allowing to screen for many metabolic pathways simultaneously. Examples are given for nontargeted analyses of IEMs, and prospects and limitations of different metabolomics methods are discussed. We conclude that dedicated studies are needed to compare accuracy and robustness of targeted and untargeted methods with respect to widening the scope of IEM diagnostics.
Thermally Developing Flow and Heat Transfer in Elliptical Minichannels with Constant Wall Temperature
Authors: Su Liangbin , Duan Zhipeng , He Boshu , Ma Hao , Xu Zairan
Published: October 2019

Laminar convective heat transfer of elliptical minichannels is investigated for hydrodynamically fully developed but thermal developing flow with no-slip condition. A three-dimensional numerical model is developed in different elliptical geometries with the aspect ratio varying from 0.2 to 1. The effect of Reynolds number (25 ≤ Re ≤ 2000) on the local Nusselt number is examined in detail. The results indicate that the local Nusselt number is a decreasing function of Reynolds number and it is sensitive to Reynolds number especially for Re less than 250. The effect of aspect ratio on local Nusselt number is small when compared with the effect of Reynolds number on local Nusselt number. The local Nusselt number is independent of cross-section geometry at the inlet. The maximum effect of aspect ratio on local Nusselt number arises at the transition section rather than the fully developed region. However, the non-dimensional thermal entrance length is a monotonic decreasing concave function of aspect ratio but a weak function of Reynolds number. Correlations for the local Nusselt number and the thermal developing length for elliptical channels are developed with good accuracy, which may provide guidance for design and optimization of elliptical minichannel heat sinks.
Characterization of the Three New Kayviruses and Their Lytic Activity Against Multidrug-Resistant Staphylococcus aureus
Authors: Łubowska Natalia , Grygorcewicz Bartłomiej , Kosznik-Kwaśnicka Katarzyna , Zauszkiewicz-Pawlak Agata , Węgrzyn Alicja , Dołęgowska Barbara , Piechowicz Lidia
Published: October 2019

The development of antimicrobial resistance has become a global concern. One approach to overcome the problem of drug resistance is the application of bacteriophages. This study aimed at characterizing three phages isolated from sewage, which show lytic activity against clinical isolates of multidrug-resistant Staphylococcus aureus. Morphology, genetics and biological properties, including host range, adsorption rate, latent time, phage burst size and lysis profiles, were studied in all three phages. As analyzed by transmission electron microscopy (TEM), phages vB_SauM-A, vB_SauM-C, vB_SauM-D have a myovirion morphology. One of the tested phages, vB_SauM-A, has relatively rapid adsorption (86% in 17.5 min), short latent period (25 min) and extremely large burst size (~500 plaque-forming units (PFU) per infected cell). The genomic analysis revealed that vB_SauM-A, vB_SauM-C, vB_SauM-D possess large genomes (vB_SauM-A 139,031 bp, vB_SauM-C 140,086 bp, vB_SauM-D 139,088 bp) with low G+C content (~30.4%) and are very closely related to the phage K (95–97% similarity). The isolated bacteriophages demonstrate broad host range against MDR S. aureus strains, high lytic activity corresponding to strictly virulent life cycle, suggesting their potential to treat S. aureus infections.
Insights into the Bacterial Profiles and Resistome Structures Following the Severe 2018 Flood in Kerala, South India
Authors: Jaya Divakaran Soumya , Sara Philip Jamiema , Chereddy Padma , Nori Sai Ravi Chandra , Jaya Ganesh Akshay , John Jiffy , Nelson-Sathi Shijulal
Published: October 2019

Extreme flooding is one of the major risk factors for human health, and it can significantly influence the microbial communities and enhance the mobility of infectious disease agents within the affected areas. The flood crisis in 2018 was one of the severe natural calamities recorded in the southern state of India (Kerala) that significantly affected its economy and ecological habitat. We utilized a combination of shotgun metagenomics and bioinformatics approaches to understand the bacterial profile and the abundance of pathogenic and antibiotic-resistant bacteria in extremely flooded areas of Kuttanad, Kerala (4–10 feet below sea level). Here we report the bacterial profiles of flooded sites that are abundant with virulent and resistant bacteria. The flooded sites were heavily contaminated with faecal contamination indicators such as Escherichia coli and Enterococcus faecalis and multidrug-resistant strains of Pseudomonas aeruginosa, Salmonella typhi/typhimurium, Klebsiella pneumoniae, Vibrio cholerae. The resistome of the flooded sites contains 103 known resistant genes, of which 38% are plasmid-encoded, where most of them are known to be associated with pathogenic bacteria. Our results reveal an overall picture of the bacterial profile and resistome of sites following a devastating flood event, which might increase the levels of pathogens and its associated risks.
Concise and Gram-Scale Total Synthesis of Lansiumamides A and B and Alatamide
Authors: Lin Ran , Lin Xi , Su Qian , Guo Binbin , Huang Yanqin , Ouyang Ming-An , Song Liyan , Xu Huiyou
Published: October 2019

The total synthesis of potent anti-obesity lansiumamide B was accomplished in four steps using commercially available materials. The synthetic strategy, featured with copper-catalyzed Buchwald coupling, is concise, convergent, practical and can be carried out on a one-gram scale. This approach could give either Z- or E-configured enamide moiety in natural products with absolute stereocontrol and was applied in the total synthesis of natural products.
Design, Synthesis, and Bioactivity Evaluation of Novel Isoxazole-Amide Derivatives Containing an Acylhydrazone Moiety as New Active Antiviral Agents
Authors: Yang Zai-Bo , Li Pei , He Yin-Ju
Published: October 2019

As a continuation of our efforts to discover and develop “me-better” active molecules, in this study, a series of novel isoxazole-amide derivatives containing an acylhydrazone moiety were synthesized and evaluated for their antiviral activities against tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV). Antiviral bioassays indicated that some of the target compounds exhibited better in vivo antiviral activities against TMV and CMV than those of Ningnanmycin (NNM). Especially, the compound 7t exhibited the best curative, protection, and inactivation activities against TMV and CMV which were superior to those of NNM. Meanwhile, our present work also revealed that compound 7t could enhance the defense-related enzyme activity and increase the chlorophyll content in tobacco leaves to induce resistance and enhance plant tolerance to TMV infection.
Oxovanadium(IV) Coordination Compounds with Kojic Acid Derivatives in Aqueous Solution
Authors: Berto Silvia , Alladio Eugenio , Daniele Pier Giuseppe , Laurenti Enzo , Bono Andrea , Sgarlata Carmelo , Valora Gabriele , Cappai Rosita , Lachowicz Joanna Izabela , Nurchi Valeria Marina
Published: October 2019

Hydroxypyrone derivatives have a good bioavailability in rats and mice and have been used in drug development. Moreover, they show chelating properties towards vanadyl cation that could be used in insulin-mimetic compound development. In this work, the formation of coordination compounds of oxovanadium(IV) with four kojic acid (5-hydroxy-2-(hydroxymethyl)-4-pyrone) derivatives was studied. The synthetized studied ligands (S2, S3, S4, and SC) have two or three kojic acid units linked through diamines or tris(2-aminoethyl)amine chains, respectively. The chemical systems were studied by potentiometry (25 °C, ionic strength 0.1 mol L−1 with KCl), and UV-visible and EPR spectroscopy. The experimental data were analyzed by a thermodynamic and a chemometric (Multivariate Curve Resolution–Alternating Least Squares) approach. Chemical coordination models were proposed, together with the species formation constants and the pure estimated UV-vis and EPR spectra. In all systems, the coordination of the oxovanadium(IV) starts already under acidic conditions (the cation is totally bound at pH higher than 3–4) and the metal species remain stable even at pH 8. Ligands S3, S4, and SC form three coordination species. Two of them are probably due to the successive insertion of the kojate units in the coordination shell, whereas the third is most likely a hydrolytic species.
Facile Preparation of CuS Nanoparticles from the Interfaces of Hydrophobic Ionic Liquids and Water
Authors: Fan Yunchang , Li Yingcun , Han Xiaojiang , Wu Xiaojie , Zhang Lina , Wang Qiang
Published: October 2019

In this work, a two-phase system composed of hydrophobic ionic liquid (IL) and water phases was introduced to prepare copper sulfide (CuS) nanoparticles. It was found that CuS particles generated from the interfaces of carboxyl-functionalized IL and sodium sulfide (Na2S) aqueous solution were prone to aggregate into nanoplates and those produced from the interfaces of carboxyl-functionalized IL and thioacetamide (TAA) aqueous solution tended to aggregate into nanospheres. Both the CuS nanoplates and nanospheres exhibited a good absorption ability for ultraviolet and visible light. Furthermore, the CuS nanoplates and nanospheres showed highly efficient photocatalytic activity in degrading rhodamine B (RhB). Compared with the reported CuS nanostructures, the CuS nanoparticles prepared in this work could degrade RhB under natural sunlight irradiation. Finally, the production of CuS from the interfaces of hydrophobic IL and water phases had the advantages of mild reaction conditions and ease of operation.
Quality Formation Mechanism of Stiff Silkworm, Bombyx batryticatus Using UPLC-Q-TOF-MS-Based Metabolomics
Authors: Xing Dongxu , Shen Guanwang , Li Qingrong , Xiao Yang , Yang Qiong , Xia Qingyou
Published: October 2019

Bombyx batryticatus is a well-known animal in traditional Chinese medicine. The aim of the research was to reveal the quality formation mechanism of B. batryticatus and to screen out the characteristic component used for the quality control. The anticonvulsant effects of B. batryticatus with a stiff time of one, five, and nine days (D1, D5 and D9, respectively) and healthy silkworm of the same developmental stage (SW) were determined by animal experiment. The dynamic changes in chemical composition were analyzed using UPLC-Q-TOF-MS-based metabolomics. D5 and D9 B. batryticatus exhibited significant anticonvulsant effects (p < 0.05 and p < 0.01, respectively). Accordingly, principal component analysis (PCA) and partial least squares discrimination analysis (PLS-DA) indicated that the chemical composition of D5 and D9 B. batryticatus changed significantly. The different metabolites mainly consisted of primary metabolites such as lipids and amino acids and secondary metabolites such as flavonoids, beauvericin, and glycolipids. Interestingly, the relative abundance of quercetin-7-O-β-d-4-O-methylglucoside, the characteristic component of B. batryticatus, increased with stiff time and was promised to be used as an index component of quality control. The results expand our understanding of the quality formation mechanism of B. batryticatus. In addition, it highlights the potential of UPLC-Q-TOF-MS-based metabolomics for the quality control purpose of TCMs.
Synthesis of New Fused Heterocyclic 2-Quinolones and 3-Alkanonyl-4-Hydroxy-2-Quinolones
Authors: Aly Ashraf A. , Hassan Alaa A. , Mohamed Nasr K. , El-Haleem Lamiaa E. Abd , Bräse Stefan , Polamo Mika , Nieger Martin , Brown Alan B.
Published: October 2019

Herein, we report the synthesis of 5,12-dihydropyrazino[2,3-c:5,6-c′]difuro[2,3-c:4,5-c′]-diquinoline-6,14(5H,12H)diones, 2-(4-hydroxy-2-oxo-1,2-dihydroquinolin-3-yl)-1,4-diphenyl- butane-1,4-diones and 4-(benzo-[d]oxazol-2-yl)-3-hydroxy-1H-[4,5]oxazolo[3,2-a]pyridine-1-one. The new candidates were synthesized and identified by different spectroscopic techniques, and X-ray crystallography.
A Glimepiride-Metformin Multidrug Crystal: Synthesis, Crystal Structure Analysis, and Physicochemical Properties
Authors: Bian Xufei , Jiang Lan , Gan Zongjie , Guan Xiaoshu , Zhang Li , Cai Linhong , Hu Xiangnan
Published: October 2019

A multidrug crystal based on drug combinations was synthesized by the solvent evaporation method. This multicomponent crystal consisted of antidiabetic drugs Glimepiride (Gli) and Metformin (Met), which was performed by single crystal X-ray structure analysis. The results showed an enhancement of the pharmaceutical properties such as lower hygroscopicity and greater accelerated stability than the parent drug Met, and a higher solubility and dissolution rate than Gli.
Erythroxylum in Focus: An Interdisciplinary Review of an Overlooked Genus
Authors: Restrepo David A. , Saenz Ernesto , Jara-Muñoz Orlando Adolfo , Calixto-Botía Iván F. , Rodríguez-Suárez Sioly , Zuleta Pablo , Chavez Benjamin G. , Sanchez Juan A. , D’Auria John C.
Published: October 2019

The genus Erythroxylum contains species used by indigenous people of South America long before the domestication of plants. Two species, E. coca and E. novogranatense, have been utilized for thousands of years specifically for their tropane alkaloid content. While abuse of the narcotic cocaine has impacted society on many levels, these species and their wild relatives contain untapped resources for the benefit of mankind in the form of foods, pharmaceuticals, phytotherapeutic products, and other high-value plant-derived metabolites. In this review, we describe the current state of knowledge of members within the genus and the recent advances in the realm of molecular biology and biochemistry.
Formation of Nanospikes on AISI 420 Martensitic Stainless Steel under Gallium Ion Bombardment
Authors: Cenev Zoran , Bartenwerfer Malte , Klauser Waldemar , Jokinen Ville , Fatikow Sergej , Zhou Quan
Published: October 2019

The focused ion beam (FIB) has proven to be an extremely powerful tool for the nanometer-scale machining and patterning of nanostructures. In this work, we experimentally study the behavior of AISI 420 martensitic stainless steel when bombarded by Ga+ ions in a FIB system. The results show the formation of nanometer sized spiky structures. Utilizing the nanospiking effect, we fabricated a single-tip needle with a measured 15.15 nanometer curvature radius and a microneedle with a nanometer sized spiky surface. The nanospikes can be made straight or angled, depending on the incident angle between the sample and the beam. We also show that the nanospiking effect is present in ferritic AISI 430 stainless steel. The weak occurrence of the nanospiking effect in between nano-rough regions (nano-cliffs) was also witnessed for austenitic AISI 316 and martensitic AISI 431 stainless steel samples.
Laser-Patternable Graphene Field Emitters for Plasma Displays
Authors: Sankaran Kamatchi Jothiramalingam , Bikkarolla Santosh Kumar , Desta Derese , Roy Susanta Sinha , Boyen Hans-Gerd , Lin I-Nan , McLaughlin James , Haenen Ken
Published: October 2019

This paper presents a plasma display device (PDD) based on laser-induced graphene nanoribbons (LIGNs), which were directly fabricated on polyimide sheets. Superior field electron emission (FEE) characteristics, viz. a low turn-on field of 0.44 V/μm and a large field enhancement factor of 4578, were achieved for the LIGNs. Utilizing LIGNs as a cathode in a PDD showed excellent plasma illumination characteristics with a prolonged plasma lifetime stability. Moreover, the LIGN cathodes were directly laser-patternable. Such superior plasma illumination performance of LIGN-based PDDs has the potential to make a significant impact on display technology.
Large Neutral Amino Acid Therapy Increases Tyrosine Levels in Adult Patients with Phenylketonuria: A Long-Term Study
Authors: Burlina Alessandro P. , Cazzorla Chiara , Massa Pamela , Polo Giulia , Loro Christian , Gueraldi Daniela , Burlina Alberto B.
Published: October 2019

The standard treatment for phenylketonuria (PKU) is a lifelong low-phenylalanine (Phe) diet, supplemented with Phe-free protein substitutes; however, adult patients often show poor adherence to therapy. Alternative treatment options include the use of large neutral amino acids (LNAA). The aim of this study was to determine the Phe, tyrosine (Tyr), and Phe/Tyr ratio in a cohort of sub-optimally controlled adult patients with classical PKU treated with a new LNAA formulation. Twelve patients received a Phe-restricted diet plus a slow-release LNAA product taken three times per day, at a dose of 1 g/kg body weight (mean 0.8 ± 0.24 g/kg/day), over a 12-month period. The product is in a microgranulated formulation, which incorporates all amino acids and uses sodium alginate as a hydrophilic carrier to prolong its release. This LNAA formulation provides up to 80% of the total protein requirement, with the rest of the protein supplied by natural food. Patients had fortnightly measurements of Phe and Tyr levels over a 12-month period after the introduction of LNAA. All patients completed the 12-month treatment period. Overall, adherence to the new LNAA tablets was very good compared with a previous amino acid mixture, for which taste was a major complaint by patients. Phe levels remained unchanged (p = 0.0522), and Tyr levels increased (p = 0.0195). Consequently, the Phe/Tyr ratio decreased significantly (p < 0.05) in the majority of patients treated. In conclusion, LNAA treatment increases Tyr levels in sub-optimally controlled adult PKU patients, while offering the potential to improve their adherence to treatment.
Dual Transcriptional Profile of Aspergillus flavus during Co-Culture with Listeria monocytogenes and Aflatoxin B1 Production: A Pathogen–Pathogen Interaction
Authors: Lappa Iliada K. , Dionysopoulou Angeliki Maria , Paramithiotis Spiros , Georgiadou Maria , Drosinos Eleftherios H.
Published: October 2019

The objective of this study was to investigate the effect of growth temperature and co-culture of Aspergillus flavus with Listeria monocytogenes on the production of Aflatoxin B1 (AFB1) and the transcriptional profile of associated regulatory and biosynthetic genes. The transcription of virulence- and homeostasis-associated genes of L. monocytogenes was also assessed. For this purpose, mono- and co-cultures of L. monocytogenes strain LQC 15257 and A. flavus strain 18.4 were inoculated into Malt Extract broth and allowed to grow for seven days at 25 °C and 30 °C. AFB1 quantification was performed by HPLC analysis and gene expression assessment by RT-qPCR. AFB1 production was lower at 30 °C compared to 25 °C during monoculture and also lower during co-cultures at both temperatures. This was accompanied by downregulation of aflM, aflR, aflP, and aflS during monoculture and aflM and aflS during co-culture at 30 °C. On the other hand, transcription of prfA, plcA, plcB, inlA, inlB, inlJ, murE, accA, acpP, as well as fapR, was not affected. sigB gene was downregulated after co-culture with the fungus at 25 °C and hly was downregulated after monoculture at 30 °C compared to 25 °C. In this work, the molecular interactions between A. flavus and L. monocytogenes were studied for the first time, offering a novel insight into their co-occurrence. Monitoring of their toxigenic and virulence potential at the molecular level revealed a complex dynamic in natural ecosystems.
Cross-Reactive Antibodies Binding to the Influenza Virus Subtype H11 Hemagglutinin
Authors: Strohmeier Shirin , Amanat Fatima , Krammer Florian
Published: October 2019

H11 subtype influenza viruses were isolated from a wide range of bird species and one strain also was isolated from swine. In an effort to generate reagents for a chimeric H11/1 hemagglutinin-based universal influenza virus vaccine candidate, we produced 28 monoclonal antibodies that recognize the H11 HA subtype. Here we characterized these antibodies in terms of binding breadth and functionality. We found that the antibodies bind broadly to North American and Eurasian lineage isolates and also show broad neutralizing activity, suggesting that immunogenic epitopes on the H11 head domain are not under strong pressure from immunity in the natural reservoir. Furthermore, we found that the antibodies were highly hemagglutination inhibition active against the homologous chimeric H11/1N1 virus, but approximately 50% lost this activity when tested against a virus expressing the same the full length H11 HA of which the head domain is present on cH11/1 HA. Furthermore, while strong neutralizing activity was found to a genetically distant North American lineage H11 isolate, little hemagglutination inhibition activity was detected. This suggests that small structural changes between wild type H11 and cH11/1 as well as between Eurasian and North American lineage H11 HAs can strongly influence the functionality of the isolated monoclonal antibodies.
Structure and Dynamics of a Site-Specific Labeled Fc Fragment with Altered Effector Functions
Authors: Gallagher D. Travis , McCullough Chris , Brinson Robert G. , Ahn Joomi , Marino John P. , Dimasi Nazzareno
Published: October 2019

Antibody-drug conjugates (ADCs) are a class of biotherapeutic drugs designed as targeted therapies for the treatment of cancer. Among the challenges in generating an effective ADC is the choice of an effective conjugation site on the IgG. One common method to prepare site-specific ADCs is to engineer solvent-accessible cysteine residues into antibodies. Here, we used X-ray diffraction and hydrogen-deuterium exchange mass spectroscopy to analyze the structure and dynamics of such a construct where a cysteine has been inserted after Ser 239 (Fc-239i) in the antibody heavy chain sequence. The crystal structure of this Fc-C239i variant at 0.23 nm resolution shows that the inserted cysteine structurally replaces Ser 239 and that this causes a domino-like backward shift of the local polypeptide, pushing Pro 238 out into the hinge. Proline is unable to substitute conformationally for the wild-type glycine at this position, providing a structural reason for the previously observed abolition of both FcγR binding and antibody-dependent cellular cytotoxicity. Energy estimates for the both the FcγR interface (7 kcal/mol) and for the differential conformation of proline (20 kcal/mol) are consistent with the observed disruption of FcγR binding, providing a quantifiable case where strain at a single residue appears to disrupt a key biological function. Conversely, the structure of Fc-C239i is relatively unchanged at the intersection of the CH2 and CH3 domains; the site known to be involved in binding of the neonatal Fc receptor (FcRn), and an alignment of the Fc-C239i structure with an Fc structure in a ternary Fc:FcRn:HSA (human serum albumin) complex implies that these favorable contacts would be maintained. Hydrogen deuterium exchange mass spectroscopy (HDX-MS) data further suggest a significant increase in conformational mobility for the Fc-C239i protein relative to Fc that is evident even far from the insertion site but still largely confined to the CH2 domain. Together, the findings provide a detailed structural and dynamic basis for previously observed changes in ADC functional binding to FcγR, which may guide further development of ADC designs.
Improved Production of Industrially Important Essential Oils Through Elicitation in the Adventitious Roots of Artemisia amygdalina
Authors: Taj Faqeer , Khan Mubarak Ali , Ali Huma , Khan Raham Sher
Published: October 2019

The limited production of bioactive essential oils in natural plants does not meet the increasing worldwide market demand. Plant cell culture technology can be used for the higher production of industrially important essential oils. In the present study, a suitable method for production of essential oils was developed through establishment and elicitation of adventitious roots (AR) in a medicinally important plant Artemisia amygdalina D. The results indicated that leaf explants cultured on solid Murashige and Skoog (MS) media supplemented with 1.0 mg/L α- naphthalene acetic acid (NAA) and 4% sucrose instigated the higher AR induction frequency (90  ±  4.25) and maximum AR biomass (fresh biomass: 17.7 g/L). Furthermore, in the AR when transiently elicited with different elicitors for different time periods, methyl jasmonate (Me-J: 0.5 mg/L) resulted in the higher production of total phenolic content (TPC: 3.6 mg), total flavonoid content (TFC: 2.3 mg) and phenylalanine ammonia-lyase (PAL: 4.8 U/g×FW) activity, respectively. Nonetheless, considerable levels of the major bioactive compounds such as α-thujene (6.8%), α-pinene (8.3%), 1,8-cineole (16.2%), camphor (8.4%) and verbenole (10.2%) were recorded in the Me-J treated AR. Thus, a feasible protocol for production of essential oils through AR in A. amygdalina was established, which can be exploited for commercial production of the industrially important terpenes.
Silicon Priming Regulates Morpho-Physiological Growth and Oxidative Metabolism in Maize under Drought Stress
Authors: Parveen Abida , Liu Wei , Hussain Saddam , Asghar Jaleel , Perveen Shagufta , Xiong Yousheng
Published: October 2019

Seed priming with silicon (Si) is an efficient and easy method to regulate plant tolerance against different abiotic stresses. A pot experiment was conducted to examine the Si-mediated changes in oxidative defense and some vital physio-biochemical parameters of maize under a limited water supply. For this purpose, two maize varieties (Pearl and Malka) with different Si priming treatments (0, 4 mM, 6 mM) were grown under a control and 60% field capacity for three weeks. At 60% field capacity, significant reductions in plant growth attributes and chlorophyll contents were recorded compared with the control. The negative effects of drought stress were more severe for Malka compared with Pearl. Drought stress increased the malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents, altered the activities of antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)), and triggered the accumulation of soluble sugars, glycine betaine, proline, and phenolics contents. Nevertheless, seed priming with silicon at 4 or 6 mM was effective in alleviating the detrimental effects of drought stress in both cultivars. Si priming particularly at 6 mM significantly enhanced the shoot and root lengths as well as their biomass and improved the levels of photosynthetic pigments. Moreover, Si treatments enhanced the activities of antioxidant enzymes (SOD, POD, and CAT) while it reduced the MDA and H2O2 contents in both cultivars under stress conditions. In crux, the present investigation suggests that Si priming mitigates the harmful effects of drought stress and contributes to the recovery of maize growth.
AgBr/BiOBr Nano-Heterostructure-Decorated Polyacrylonitrile Nanofibers: A Recyclable High-Performance Photocatalyst for Dye Degradation under Visible-Light Irradiation
Authors: Zhang Mingyi , Qi Ying , Zhang Zhenyi
Published: October 2019

Macrostructural flexible photocatalysts have been proven to have desirable recyclable properties during the photocatalytic degradation of organic pollutants in water. However, the photocatalytic activities of these photocatalysts are often unsatisfactory due to the fast recombination of charge carriers and the limited surface active sites. Herein, we developed a novel flexible photocatalyst of AgBr/BiOBr/polyacrylonitrile (PAN) composite mats (CMs) through the controllable assembly of AgBr/BiOBr nano-heterostructures on electrospun polyacrylonitrile nanofibers (PAN NFs) via a three-step synthesis route. The component ratio of AgBr to BiOBr in the CMs could be easily adjusted by controlling the in situ ion exchange process. The charge–transfer process occurring at the interface of the AgBr/BiOBr nano-heterostructures strongly hindered the recombination of photoinduced electron–hole pairs, thereby effectively enhancing the photocatalytic activity of the AgBr/BiOBr/PAN CMs. Meanwhile, the unique hierarchical inorganic/organic heterostructure of the AgBr/BiOBr/PAN CMs not only led to good flexibility, but also provided an abundance of active sites for photocatalytic reactions. Upon visible-light irradiation, AgBr/BiOBr/PAN CMs with an optimal ratio of AgBr to BiOBr components exhibited both enhanced photocatalytic activity and excellent separability during the degradation of methyl orange in water compared to the BiOBr/PAN CMs.
Tough Polyelectrolyte Hydrogels with Antimicrobial Property via Incorporation of Natural Multivalent Phytic Acid
Authors: Bui Hoang Linh , Huang Chun-Jen
Published: October 2019

Tough and antimicrobial dual-crosslinked poly((trimethylamino)ethyl methacrylate chloride)-phytic acid hydrogel (pTMAEMA-PA) has been synthesized by adding a chemical crosslinker and docking a physical crosslinker of multivalent phytic acid into a cationic polyelectrolyte network. By increasing the loading concentration of PA, the tough hydrogel exhibits compressive stress of >1 MPa, along with high elasticity and fatigue-resistant properties. The enhanced mechanical properties of pTMAEMA-PA stem from the multivalent ion effect of PA via the formation of ion bridges within polyelectrolytes. In addition, a comparative study for a series of pTMAEMA-counterion complexes was conducted to elaborate the relationship between swelling ratio and mechanical strength. The study also revealed secondary factors, such as ion valency, ion specificity and hydrogen bond formation, holding crucial roles in tuning mechanical properties of the polyelectrolyte hydrogel. Furthermore, in bacteria attachment and disk diffusion tests, pTMAEMA-PA exhibits superior fouling resistance and antibacterial capability. The results reflect the fact that PA enables chelating strongly with divalent metal ions, hence, disrupting the outer membrane of bacteria, as well as dysfunction of organelles, DNA and protein. Overall, the work demonstrated a novel strategy for preparation of tough polyelectrolyte with antibacterial capability via docking PA to open up the potential use of PA in medical application.
Effect of Initial Salt Composition on Physicochemical and Structural Characteristics of Zero-Valent Iron Nanopowders Obtained by Borohydride Reduction
Authors: Leybo Denis , Tagirov Marat , Arkhipov Dmitry , Permyakova Elizaveta , Kolesnikov Evgeny , Kuznetsov Denis
Published: October 2019

The effect of initial salt composition on characteristics of zero-valent iron nanopowders produced via borohydride reduction was studied. The samples were characterized by X-ray diffraction, scanning and transmission electron microscopy, and low-temperature nitrogen adsorption. The efficiency of Pb2+ ions removal from aqueous media was evaluated. The use of ferric salts led to enhanced reduction kinetics and, consequently, to a smaller size of iron particles in comparison with ferrous salts. A decrease in the ionic strength of the synthesis solutions resulted in a decrease in iron particles. The formation of small highly-reactive iron particles during synthesis led to their oxidation during washing and drying steps with the formation of a ferrihydrite phase. The lead ions removal efficiency was improved by simultaneous action of zero-valent iron and ferrihydrite phases of the sample produced from iron sulphate.
Experimental Study on Forced Convection Heat Transfer from Plate-Fin Heat Sinks with Partial Heating
Authors: Lee Jae Jun , Kim Hyun Jung , Kim Dong-Kwon
Published: October 2019

In this study, plate-fin heat sinks with partial heating under forced convection were experimentally investigated. The base temperature profiles of the plate-fin heat sinks were measured for various heating lengths, heating positions, flow rates, and channel widths. From the experimental data, the effects of heating length, heating position, and flow rate on the base temperature profile and the thermal performance were investigated. Finally, the characteristics of the optimal heating position were investigated. As a result, it was shown that the optimal heating position was on the upstream side in the case of the heat sinks under laminar developing flow, as opposed to the heat sinks under turbulent flow. It was also shown that the optimal heating position could change significantly due to heat losses through the front and back of the heat sink, while the effects of the heat loss through the sides of the heat sink on the optimal heating position were negligible. In addition, it was shown that the one-dimensional numerical model with empirical coefficients could predict the important trends in the measured temperature profiles, thermal resistances, and optimal heating lengths.
Questionnaires to Measure Acceptability of Social Robots: A Critical Review
Authors: Krägeloh Christian U. , Bharatharaj Jaishankar , Sasthan Kutty Senthil Kumar , Nirmala Praveen Regunathan , Huang Loulin
Published: October 2019

Understanding user perceptions is particularly important in developing social robots, which tend to have a high degree of interaction with humans. However, psychometric measures of robot acceptability have only recently started to become available. The present critical review outlines the psychometrically validated questionnaires to measure social acceptability factors related to social robots. Using an iterative search strategy, articles were identified that reported on the development of such questionnaires as well as information about their psychometric properties. Six questionnaires were identified that provide researchers with options varying in length, content, and factor structure. Two of these questionnaires inquire about attitudes and anxieties related to robots, while two others capture a larger range of attitudes that extends to positive and neutral aspects as well. One of the questionnaires reviewed here was specific to inquiring about ethical issues related to the use of social robots for therapy with children with autism, and the last one was designed to provide an assessment of expectations of participants prior to interacting with a robot. Overall, the use of robot acceptability measures is still relatively new, and further psychometric work is necessary to provide confidence in the validity and reliability of these scales.
Upper Ocean Response to Two Sequential Tropical Cyclones over the Northwestern Pacific Ocean
Authors: Ning Jue , Xu Qing , Feng Tao , Zhang Han , Wang Tao
Published: October 2019

The upper ocean thermodynamic and biological responses to two sequential tropical cyclones (TCs) over the Northwestern Pacific Ocean were investigated using multi-satellite datasets, in situ observations and numerical model outputs. During Kalmaegi and Fung-Wong, three distinct cold patches were observed at sea surface. The locations of these cold patches are highly correlated with relatively shallower depth of the 26 °C isotherm and mixed layer depth (MLD) and lower upper ocean heat content. The enhancement of surface chlorophyll a (chl-a) concentration was detected in these three regions as well, mainly due to the TC-induced mixing and upwelling as well as the terrestrial runoff. Moreover, the pre-existing ocean cyclonic eddy (CE) has been found to significantly modulate the magnitude of surface cooling and chl-a increase. With the deepening of the MLD on the right side of TCs, the temperature of the mixed layer decreased and the salinity increased. The sequential TCs had superimposed effects on the upper ocean response. The possible causes of sudden track change in sequential TCs scenario were also explored. Both atmospheric and oceanic conditions play noticeable roles in abrupt northward turning of the subsequent TC Fung-Wong.
Spatial Resolution Matching of Microwave Radiometer Data with Convolutional Neural Network
Authors: Li Yade , Hu Weidong , Chen Shi , Zhang Wenlong , Guo Rui , He Jingwen , Ligthart Leo
Published: October 2019

Passive multi-frequency microwave remote sensing is often plagued with the problems of low- and non-uniform spatial resolution. In order to adaptively enhance and match the spatial resolution, an accommodative spatial resolution matching (ASRM) framework, composed of the flexible degradation model, the deep residual convolutional neural network (CNN), and the adaptive feature modification (AdaFM) layers, is proposed in this paper. More specifically, a flexible degradation model, based on the imaging process of the microwave radiometer, is firstly proposed to generate suitable datasets for various levels of matching tasks. Secondly, a deep residual CNN is introduced to jointly learn the complicated degradation factors of the data, so that the resolution can be matched up to fixed levels with state of the art quality. Finally, the AdaFM layers are added to the network in order to handle arbitrary and continuous resolution matching problems between a start and an end level. Both the simulated and the microwave radiation imager (MWRI) data from the Fengyun-3C (FY-3C) satellite have been used to demonstrate the validity and the effectiveness of the method.
A New Processing Chain for Real-Time Ground-Based SAR (RT-GBSAR) Deformation Monitoring
Authors: Wang Zheng , Li Zhenhong , Liu Yanxiong , Peng Junhuan , Long Sichun , Mills Jon
Published: October 2019

Due to the high temporal resolution (e.g., 10 s) required, and large data volumes (e.g., 360 images per hour) that result, there remain significant issues in processing continuous ground-based synthetic aperture radar (GBSAR) data. This includes the delay in creating displacement maps, the cost of computational memory, and the loss of temporal evolution in the simultaneous processing of all data together. In this paper, a new processing chain for real-time GBSAR (RT-GBSAR) is proposed on the basis of the interferometric SAR small baseline subset concept, whereby GBSAR images are processed unit by unit. The outstanding issues have been resolved by the proposed RT-GBSAR chain with three notable features: (i) low requirement of computational memory; (ii) insights into the temporal evolution of surface movements through temporarily-coherent pixels; and (iii) real-time capability of processing a theoretically infinite number of images. The feasibility of the proposed RT-GBSAR chain is demonstrated through its application to both a fast-changing sand dune and a coastal cliff with submillimeter precision.
Underwater Acoustic Sensor Networks Node Localization Based on Compressive Sensing in Water Hydrology
Authors: Wang Sen , Lin Yun , Tao Hongxu , Sharma Pradip Kumar , Wang Jin
Published: October 2019

Groundwater is an important source of human activities, agriculture and industry. Underwater Acoustic Sensor Networks (UASNs) is one of the important technologies for marine environmental monitoring. Therefore, it is of great significance to study the node self- localization technology of underwater acoustic sensor network. This paper mainly studies the node localization algorithm based on range-free. In order to save cost and energy consumption, only a small number of sensing nodes in sensor networks usually know their own location. How to locate all nodes accurately through these few nodes is the focus of our research. In this paper, combined with the compressive sensing algorithm, a range-free node localization algorithm based on node hop information is proposed. Aiming at the problem that connection information collected by the algorithm is an integer, the hop is modified to further improve the localization performance. The simulation analysis shows that the improved algorithm is effective to improve the localization accuracy without additional cost and energy consumption compared with the traditional method.