bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient Catalytic Microreactors with Atomic‐Layer‐Deposited Platinum Nanoparticles on Oxide Support
Authors: Rontu Ville , Selent Anne , Zhivonitko Vladimir V. , Scotti Gianmario , Koptyug Igor V. , Telkki Ville‐Veikko , Franssila Sami
Published: September 2017

Microreactors attract a significant interest for chemical synthesis due to the benefits of small scales such as high surface to volume ratio, rapid thermal ramping, and well‐understood laminar flows. The suitability of atomic layer deposition for application of both the nanoparticle catalyst and the support material on the surfaces of channels of microfabricated silicon microreactors is demonstrated in this research. Continuous‐flow hydrogenation of propene into propane at low temperatures with TiO2‐supported catalytic Pt nanoparticles was used as a model reaction. Reaction yield and mass transport were monitored by high‐sensitivity microcoil NMR spectroscopy as well as time‐of‐flight remote detection NMR imaging. The microreactors were shown to be very efficient in propene conversion into propane. The yield of 100 % was achieved at 50 °C with a reactor decorated with Pt nanoparticles of average size of roughly 1 nm and surface coverage of 3.2 % in 20 mm long reaction channels with a residence time of 1100 ms. The activity of the Pt catalyst surfaces was on the order of several to tens of mmol s−1 m−2.
A Reusable N‐Doped‐Carbon‐Coated Mo2C Composite Counter Electrode for High‐Efficiency Dye‐Sensitized Solar Cells
Authors: Wang Ting , Wang Jiabo , Chen Weilin , Zheng Xiaotao , Wang Enbo
Published: September 2017

The design and development of efficient and stable nonprecious‐metal‐based catalysts for counter electrodes (CEs) in dye‐sensitized solar cells (DSSCs) has received a great deal of attention. In this work, molybdenum carbide nanoparticles homogeneously distributed in a nitrogen‐rich carbon matrix (Mo2C@NC) have been synthesized from inexpensive raw materials (polyoxometalate and dicyandiamide) by a facile one‐step solid‐phase synthesis method. The novel Mo2C@NC hybrid was not only used as a CE in a DSSC, but also showed superior catalytic activity towards I3−/I− as a redox electrolyte. The power conversion efficiency of a DSSC with Mo2C@NC as the CE was as high as 6.49 %, comparable to that with Pt (6.38 %). The CE was prepared by a drop‐coating method, without the addition of another conductive polymer. Most importantly, the method circumvents the problem of the sample falling off from the fluorine‐doped tin oxide (FTO), and the CE could be repeatedly reused with unchanged efficiency. Therefore, it opens the way for the development of platinum‐free catalysts with low cost, simple processing, good stability, and high efficiency.
Antibacterial activity of silver and zinc oxide nanoparticles produced by spark discharge in deionized water
Authors: Jamali Amir , Razavizadeh Serajoddin , Aliahmadi Atousa , Ghomi Hamid
Published: September 2017

Inorganic antibacterial agents such as metal nanoparticles (NPs) are very important in biomedical and pharmaceutical areas. There are many methods of synthesizing these NPs, but all of them have their own disadvantages. In this study, ultrasonic‐assisted spark discharge is employed to produce colloidal silver (Ag) and zinc oxide (ZnO) NPs which are stable without using any stabilizers or surfactants. Different tests such as X‐ray diffraction, field emission scanning electron microscopy, and ultraviolet–visible absorption spectroscopy are used for the characterization of the quantity and quality of these NPs, and their antibacterial activity is evaluated by the disk diffusion method and determination of the minimum inhibitory concentrations against Escherichia coli. The results show that the overall antibacterial activity of Ag NPs is higher than that of ZnO NPs.
Effects of lightning on trees: A predictive model based on in situ electrical resistivity
Authors: Gora Evan M. , Bitzer Phillip M. , Burchfield Jeffrey C. , Schnitzer Stefan A. , Yanoviak Stephen P.
Published: September 2017

The effects of lightning on trees range from catastrophic death to the absence of observable damage. Such differences may be predictable among tree species, and more generally among plant life history strategies and growth forms. We used field‐collected electrical resistivity data in temperate and tropical forests to model how the distribution of power from a lightning discharge varies with tree size and identity, and with the presence of lianas. Estimated heating density (heat generated per volume of tree tissue) and maximum power (maximum rate of heating) from a standardized lightning discharge differed 300% among tree species. Tree size and morphology also were important; the heating density of a hypothetical 10 m tall Alseis blackiana was 49 times greater than for a 30 m tall conspecific, and 127 times greater than for a 30 m tall Dipteryx panamensis. Lianas may protect trees from lightning by conducting electric current; estimated heating and maximum power were reduced by 60% (±7.1%) for trees with one liana and by 87% (±4.0%) for trees with three lianas. This study provides the first quantitative mechanism describing how differences among trees can influence lightning–tree interactions, and how lianas can serve as natural lightning rods for trees.
Gut microbiomes of mobile predators vary with landscape context and species identity
Authors: Tiede Julia , Scherber Christoph , Mutschler James , McMahon Katherine D. , Gratton Claudio
Published: September 2017

Landscape context affects predator–prey interactions and predator diet composition, yet little is known about landscape effects on insect gut microbiomes, a determinant of physiology and condition. Here, we combine laboratory and field experiments to examine the effects of landscape context on the gut bacterial community and body condition of predatory insects. Under laboratory conditions, we found that prey diversity increased bacterial richness in insect guts. In the field, we studied the performance and gut microbiota of six predatory insect species along a landscape complexity gradient in two local habitat types (soybean fields vs. prairie). Insects from soy fields had richer gut bacteria and lower fat content than those from prairies, suggesting better feeding conditions in prairies. Species origin mediated landscape context effects, suggesting differences in foraging of exotic and native predators on a landscape scale. Overall, our study highlights complex interactions among gut microbiota, predator identity, and landscape context.
Effects of Terminal Substitution and Iron Coordination on Antiproliferative Activity of l‐Proline‐salicylaldehyde–Thiosemicarbazone Hybrids
Authors: Milunović Miljan N. M. , Dobrova Aliona , Novitchi Ghenadie , Gligorijević Nevenka , Radulović Siniša , Kožišek Jozef , Rapta Peter , Enyedy Eva A. , Arion Vladimir B.
Published: September 2017

A series of five iron(III) complexes, namely [Fe(HL1)Cl2] (1), [Fe(HL2)Cl2]·1.6H2O (2·1.6H2O), [Fe(HL3)(MeOH)Cl2]·0.5H2O (3·0.5H2O), [Fe(HL4)(MeOH)Cl2]·0.5H2O (4·0.5H2O) and [Fe(HL4)(DMF)Cl2]·0.5Et2O·H2O (4′·0.5Et2O·H2O), where H2L1 = l‐proline‐salicylaldehyde–thiosemicarbazone (l‐Pro‐STSC), H2L2 = pyrrolidine‐substituted l‐Pro‐STSC, H2L3 = phenyl‐substituted l‐Pro‐STSC, and H2L4 = naphthyl‐substituted l‐Pro‐STSC, have been synthesized. The two ligand precursors (H2L3 and H2L4) and iron complexes were characterized by elemental analysis, spectroscopic methods (UV/Vis, IR, and NMR), ESI mass spectrometry, cyclic voltammetry, and single‐crystal X‐ray crystallography (1–3 and 4′). Magnetic properties of the five‐coordinate complex 2 and six‐coordinate complex 4 have also been investigated. The antiproliferative activity of the organic hybrids and their iron(III) complexes have been studied in vitro in five human cell lines and one murine cancer cell line, namely HeLa (cervical cancer), FemX (melanoma), A549 (alveolar basal adenocarcinoma), LS‐174 (colon cancer), MDA‐MB‐453 (breast cancer) and MS1 (transformed murine endothelial), as well as in human noncancerous fetal lung fibroblast cell line (MRC‐5). According to the structure–activity relationship, introduction of aromatic groups such as phenyl or naphthyl enhances the cytotoxic potency of the hybrids in the following order H2L1 < H2L2 < H2L3 < H2L4. Coordination of the hybrids to iron(III) improves their antiproliferative activity in the majority of investigated cell lines with exception of H2L3 in LS‐174, H2L4 in MS1, and both H2L3 and H2L4 in FemX cell lines, where an opposite effect was observed.
Convenient and Environmentally Friendly Production of Isostearic Acid with Protonic Forms of Ammonium Cationic Zeolites
Authors: Sarker Majher I. , Latona Renee J. , Moreau Robert A. , Micheroni Daniel , Jones Kerby C. , Ngo Helen
Published: September 2017

Three ammonium‐cationic zeolites (ferrierite, ZSM5, and zeolite BETA) are individually analyzed to produce branched‐chain fatty acid (i.e., isostearic acid) from unsaturated linear‐chain fatty acid (ulc‐FA) with up to 98% conversion and 80% selectivity. The SiO2/Al2O3 molar ratio of zeolite, amount of water and choice of additive are found to be the key factors for the efficiency of zeolites in this particular reaction. Detailed characterization of zeolites supports the optimization parameters to produce the best results. Large scale production of isostearic acid achieving a 76% selectivity and 96% conversion demonstrates the potential of this system's capability at the pilot scale. Variation in isomeric composition of branched‐chain fatty acid (bc‐FA) product is observed for the three different catalytic methods. Dimer production due to interaction with the external acidic surface of these zeolites has been observed, but it can be suppressed.

Practical Application: Lubricant, cosmetic and surfactant fields are examples where these biodegradable isostearic acid and other bc‐FA materials are applied.

Three ammonium cationic zeolites (i.e., ferrierite, BETA, ZSM‐5) are used to produce the iso‐oleic acid (precursor of isostearic acid) with high selectivity. The iso‐oleic acid products are found to have different isomeric compositions which could potentially expand the application of the isostearic acid.
A Voltammetric Sensory System for Recognition of Propranolol Enantiomers Based on Glassy Carbon Electrodes Modified by Polyarylenephthalide Composites of Melamine and Cyanuric Acid
Authors: Zilberg Rufina A. , Sidelnikov Artem V. , Maistrenko Valery N. , Yarkaeva Yulia A. , Khamitov Edward M. , Kornilov Viktor M. , Maksutova Elza I.
Published: September 2017

An enantioselective voltammetric sensory system based on glassy carbon electrodes modified by polyarylenephthalide composites of melamine and cyanuric acid using chemometric method principal component analysis for the recognition of propranolol enantiomers was developed. It is shown that glassy carbon electrodes modified by polyarylenephthalide composites of melamine and cyanuric acid exhibit the properties of enantioselective sensors. The molecular dynamics simulations of the interaction processes of propranolol enantiomers with polyarylenephthalide composites of melamine and cyanuric acid show that the differences between the voltammograms of propranolol enantiomers on such electrodes are due to differences in the energy of hydrogen bonds formation between enantiomeric molecules and supramolecules of melamine and cyanuric acid. This is reflected not only in the characteristics and shape of the voltammograms, but also in the sensitivity of the electrodes, with respect to the propranolol enantiomers. The possibilities of the sensory system for express recognition of R‐ and S‐propranolol are considered. The recognition of these enantiomers by the registered voltammograms on two glassy carbon electrodes modified by polyarylenephthalide composites of melamine and cyanuric acid allows to increase significantly the percentage of correctly recognised samples in comparison with the registration of voltammograms on only one electrode.
Optimization of cell culture‐derived influenza A virus particles purification using sulfated cellulose membrane adsorbers
Authors: Fortuna Ana Raquel , Taft Florian , Villain Louis , Wolff Michael W. , Reichl Udo
Published: September 2017

Downstream processing remains one of the biggest challenges in manufacturing of biologicals and vaccines. This work focuses on a Design of Experiments approach to understand factors influencing the performance of sulfated cellulose membrane adsorbers for the chromatographic purification of a cell culture‐derived H1N1 influenza virus strain (A/Puerto Rico/8/34). Membranes with a medium ligand density together with low conductivity and a high virus titer in the feed stream resulted in optimum virus yields and low protein and DNA content in the product fraction. Flow rate and salt concentration in the buffer used for elution were of secondary importance while membrane permeability had no significant impact on separation performance. A virus loss of 2.1% in the flow through, a yield of 57.4% together with a contamination level of 5.1 pgDNA HAU−1 and 1.2 ngprot HAU−1 were experimentally confirmed for the optimal operating point predicted. The critical process parameters identified and their optimal settings should support the optimization of sulfated cellulose membrane adsorbers based purification trains for other influenza virus strains, streamlining cell culture‐derived vaccine manufacturing.
An exponential–gamma mixture model for extreme Santa Ana winds
Authors: Bopp Gregory P. , Shaby Benjamin A.
Published: September 2017

We analyze the behavior of extreme winds occurring in Southern California during the Santa Ana wind season using a latent mixture model. This mixture representation is formulated as a hierarchical Bayesian model and fit using Markov chain Monte Carlo. The two‐stage model results in generalized Pareto margins for exceedances and generates temporal dependence through a latent Markov process. This construction induces asymptotic independence in the response, while allowing for dependence at extreme, but subasymptotic, levels. We compare this model with a frequentist analogue where inference is performed via maximum pairwise likelihood. We use interval censoring to account for data quantization and estimate the extremal index and probabilities of multiday occurrences of extreme Santa Ana winds over a range of high thresholds.
Performance evaluation of anodic nano‐catalyst for direct methanol alkaline fuel cell
Authors: Yavari Zahra , Noroozifar Meissam , Parvizi Tayebeh
Published: September 2017

In this study, a nano‐scale perovskite NdFeO3 (NdFeO3NPs) was synthesized with usage a rapid ultrasonic‐assisted co‐precipitation process and characterized by several techniques such as Fourier transform infrared spectra, X‐ray powder diffraction, SEM and energy dispersive X‐ray. Electrochemical studies using a modified glassy carbon electrode with Pd nanoparticles (PdNPs) and NdFeO3NPs showed that the proposed multifunctional nanocatalyst can be used as an alternative catalyst toward methanol oxidation (MO). A single cell of direct methanol alkaline fuel cell was designed, assembled and tested using PdNPs‐NdFeO3NPs‐CH nanocomposites as an anodic catalyst. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 597–604, 2018

NdFeO3 perovskite nanoparticles were synthesized and characterized.

Catalysts with Pd and NdFeO3 nanoparticles dispersed in chitosan were prepared.

Catalytic activity of nanocatalysts toward MO was studied.

A single fuel cell was designed, assembled and tested with nanocatalyst.
Application case study of enhanced coal bed methane recovery process in thar coal fields
Authors: Zahid Umer
Published: September 2017

Enhanced coal bed methane recovery (ECBM) process is an important developing technology because of its dual advantage, i.e., producing methane gas and sequestering CO2 at the same time. CO2 have been used for enhanced oil recovery (EOR) for more than five decades but available storage sites for EOR are only limited to oil rich countries. Pakistan has one of the largest coal reserves in the world accounting to more than 185 billion tons. In this study, CO2 sequestration in the coalbeds of Thar coal field located in the South of Pakistan is explored from the technical and economical point of view. Potential CO2 storage capacity and methane gas‐in‐place has been calculated for the Thar coal fields. Next, an economic analysis has been performed to evaluate the cost of CO2 storage and to explore any economic benefit from the methane production. Usually, coal reservoirs are saturated with water, hence water production along with methane is inevitable. This study analyzed various water treatment methods and recommended shallow re‐injection technology to be the most suitable for the Thar coal ECBM process. In addition, carbon balance has been investigated to calculate the CO2 avoided during the ECBM process. Finally, a sensitivity analysis has been performed on some of the important design variables in order to analyze their effect on the cost of CO2 storage. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 900–911, 2018
Neural correlates of interoception: Effects of interoceptive focus and relationship to dimensional measures of body awareness
Authors: Stern Emily R. , Grimaldi Stephanie J. , Muratore Alexandra , Murrough James , Leibu Evan , Fleysher Lazar , Goodman Wayne K. , Burdick Katherine E.
Published: September 2017

Interoception has been defined as the sensing of the physiological condition of the body, with interoceptive sensibility (IS) characterizing an individual's self‐reported awareness of internal sensation. IS is a multidimensional construct including not only the tendency to be aware of sensation but also how sensations are interpreted, regulated, and used to inform behavior, with different dimensions relating to different aspects of health and disease. Here we investigated neural mechanisms of interoception when healthy individuals attended to their heartbeat and skin temperature, and examined the relationship between neural activity during interoception and individual differences in self‐reported IS using the Multidimensional Scale of Interoceptive Awareness (MAIA). Consistent with prior work, interoception activated a network involving insula and sensorimotor regions but also including occipital, temporal, and prefrontal cortex. Differences based on interoceptive focus (heartbeat vs skin temperature) were found in insula, sensorimotor regions, occipital cortex, and limbic areas. Factor analysis of MAIA dimensions revealed 3 dissociable components of IS in our dataset, only one of which was related to neural activity during interoception. Reduced scores on the third factor, which reflected reduced ability to control attention to body sensation and increased tendency to distract from and worry about aversive sensations, was associated with greater activation in many of the same regions as those involved in interoception, including insula, sensorimotor, anterior cingulate, and temporal cortex. These data suggest that self‐rated interoceptive sensibility is related to altered activation in regions involved in monitoring body state, which has implications for disorders associated with abnormality of interoception. Hum Brain Mapp 38:6068–6082, 2017. © 2017 Wiley Periodicals, Inc.
Are children rational decision makers when they are asked to value their own health? A contingent valuation study conducted with children and their parents
Authors: Guerriero Carla , Cairns John , Bianchi Fabrizio , Cori Liliana
Published: September 2017

Despite the importance of including children's preferences in the valuation of their own health benefits, no study has investigated the ability of children to understand willingness‐to‐pay (WTP) questions. Using a contingent valuation method, we elicit children's and parents' WTP to reduce children's risk of an asthma attack. Our results suggest that children are able to understand and value their own health risk reductions, and their ability to do so improves with age. Child age was found to be inversely related to parents' and children's WTP. The results also suggest that non‐paternalistic altruism is predictive of children's WTP. For parents, care for their own health was found to be inversely related with their WTP for children's risk reductions. Comparison of parents' and children's WTP suggests that parents are willing to sacrifice for their child's health risk reduction an amount that is approximately twice that of their children. The analysis of matched pairs of parents and children suggest that there are within‐household similarities as the child's WTP is positively related to parents' WTP.
Reassessing the safety concerns of utilizing blood donations from patients with hemochromatosis
Authors: Winters Adam C. , Tremblay Douglas , Arinsburg Suzanne , Mascarenhas John , Schiano Thomas D.
Published: September 2017

Hereditary hemochromatosis (HH) is a genetic disorder of iron metabolism that may lead to iron overload. Clinical penetrance is low, however those afflicted may develop cirrhosis, hepatocellular carcinoma, diabetes mellitus, and cardiomyopathy. Treatment of HH involves regular phlebotomy to reduce the systemic iron burden. In many countries—including the United States—numerous blood centers do not accept donated blood obtained from HH patients during therapeutic phlebotomy and there are inconsistent positions regarding this globally. This refusal of blood is borne out of a few concerns. First, there is a theoretical increase in the infectious risk of these blood products, particularly by siderophilic organisms such as Yersinia enterocolitica. Second, given the increased incidence of hepatitis C infection from nonvoluntary donors in the 1970s, there is a concern that blood units from HH donors may harbor additional risk given the nonvoluntary nature of their presentation. In this review, we examine the existing biological and clinical data concerning infectious risk and summarize clinical experience from centers allowing HH donors, and demonstrate that blood from HH patients is safe and should be allowed into the donor pool. We conclude that there is no convincing evidence to exclude this population from serving as blood donors. (Hepatology 2018;67:1150–1157)
Nuclear lamina genetic variants, including a truncated LAP2, in twins and siblings with nonalcoholic fatty liver disease
Authors: Brady Graham F. , Kwan Raymond , Ulintz Peter J. , Nguyen Phirum , Bassirian Shirin , Basrur Venkatesha , Nesvizhskii Alexey I. , Loomba Rohit , Omary M. Bishr
Published: September 2017

Nonalcoholic fatty liver disease (NAFLD) is becoming the major chronic liver disease in many countries. Its pathogenesis is multifactorial, but twin and familial studies indicate significant heritability, which is not fully explained by currently known genetic susceptibility loci. Notably, mutations in genes encoding nuclear lamina proteins, including lamins, cause lipodystrophy syndromes that include NAFLD. We hypothesized that variants in lamina‐associated proteins predispose to NAFLD and used a candidate gene‐sequencing approach to test for variants in 10 nuclear lamina‐related genes in a cohort of 37 twin and sibling pairs: 21 individuals with and 53 without NAFLD. Twelve heterozygous sequence variants were identified in four lamina‐related genes (ZMPSTE24, TMPO, SREBF1, SREBF2). The majority of NAFLD patients (>90%) had at least one variant compared to <40% of controls (P < 0.0001). When only insertions/deletions and changes in conserved residues were considered, the difference between the groups was similarly striking (>80% versus <25%; P < 0.0001). Presence of a lamina variant segregated with NAFLD independently of the PNPLA3 I148M polymorphism. Several variants were found in TMPO, which encodes the lamina‐associated polypeptide‐2 (LAP2) that has not been associated with liver disease. One of these, a frameshift insertion that generates truncated LAP2, abrogated lamin–LAP2 binding, caused LAP2 mislocalization, altered endogenous lamin distribution, increased lipid droplet accumulation after oleic acid treatment in transfected cells, and led to cytoplasmic association with the ubiquitin‐binding protein p62/SQSTM1. Conclusion: Several variants in nuclear lamina‐related genes were identified in a cohort of twins and siblings with NAFLD; one such variant, which results in a truncated LAP2 protein and a dramatic phenotype in cell culture, represents an association of TMPO/LAP2 variants with NAFLD and underscores the potential importance of the nuclear lamina in NAFLD. (Hepatology 2018;67:1710‐1725).
Establishing personal trust‐based connections in distributed teams
Authors: Calefato Fabio , Lanubile Filippo
Published: September 2017

Trust is a factor that dramatically contributes to the success or failure of distributed software teams. We present a research model showing that social communication between distant developers enables the affective appraisal of trustworthiness even from a distance, thus increasing project performance. To overcome the limitations of self‐reported data, typically questionnaires, we focus on software projects following a pull request‐based development model and approximate the overall performance of a software project with the history of successful collaborations occurring between developers.
Effects of response‐contingent stimulus pairing on vocalizations of nonverbal children with autism
Authors: Lepper Tracy L. , Petursdottir Anna Ingeborg
Published: September 2017

Research on stimulus–stimulus pairing to induce novel vocalizations in nonverbal children has typically employed response‐independent pairing (RIP) procedures to condition speech sounds as reinforcers. The purpose of the present study was to evaluate the effects of a response‐contingent pairing (RCP) procedure on the vocalizations of three nonverbal boys diagnosed with autism spectrum disorder. During RCP, adult‐delivered sounds that were either paired with a preferred item (target sounds) or not (nontarget sounds) were presented contingent on a button‐press response. In Experiment 1, RCP was compared with an RIP procedure, in which the timing of sound presentations was yoked to the preceding RCP session. RCP produced a greater effect on all participants' target vocalizations than RIP. Experiment 2 demonstrated the effects of differential reinforcement of the vocalizations induced in Experiment 1. The results suggest that RCP may develop vocalizations more reliably than RIP procedures.
Evaluation of polyacrylonitrile electrospun nano‐fibrous mats as leukocyte removal filter media
Authors: Pourbaghi Raha , Zarrebini Mohammad , Semnani Dariush , Pourazar Abbasali , Akbari Nahid , Shamsfar Reihaneh
Published: September 2017

Removal of leukocytes from blood products is the most effective means for elimination of undesirable side effects and prevention of possible reactions in recipients. Micro‐fibrous mats are currently used for removal of leukocytes from blood. In this study, samples of electrospun nano‐fibrous mats were produced. The performance of the produced electrospun nano‐fibrous mats as means of leukocytes removal from fresh whole blood was both evaluated and compared with that of commercially available micro‐fibrous mats. In order to produce the samples, polyacrylonitrile (PAN) nano‐fibrous mats were made under different electrospinning conditions. Mean fiber diameter, pore characterization and surface roughness of the PAN nano‐fibrous mats were determined using image processing technique. In order to evaluate the surface tension of the fabricated mats, water contact angle was measured. The leukocyte removal performance, erythrocytes recovery percent and hemolysis rate of the nano‐fibrous mats were compared. The effectiveness of nano‐fibrous mats in removing leukocyte was established using both scanning electron microscope and optical microscope. Results showed that for given weight, the fabricated nano‐fibrous mats were not only more efficient but also more cost‐effective than their commercial counterparts. Results confirmed that changes in mean fiber diameter, the number of layer and weight of each layer in the absence of any chemical reaction or physical surface modification, the fabricated nano‐fibrous mats were able to remove 5‐log of leukocytes. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1759–1769, 2018.
Poly(glycerol sebacate) combined with chondroitinase ABC promotes spinal cord repair in rats
Authors: Pan Qi , Guo Yan , Kong Fanyong
Published: September 2017

This study was to investigate the feasibility of PGS combined with ChABC for repairing the transection of spinal cords (TSC) in rats. A thoracic 10 (T10) TSC model of rats was employed. The effects of PGS with ChABC on the morphology and histological structure of the spinal cords, Basso, Beattie, Bresnahan (BBB) scores, and the expression of GAP‐43 and NF‐200 were comparatively studied. The BBB scores indicated that all rats with TSC were paralyzed immediately after surgery and then recovered hind limb movement gradually, but did not fully recover until the end of week 12. The rats treated with PGS alone, ChABC alone, and PGS/ChABC recovered significantly (p < 0.05) better than the control rats with TSC only. The PGS/ChABC treated rats recovered significantly (p < 0.05) more movement function than the rats treated with PGS or ChABC treated alone. The spinal cords in the control rats showed lusterless surfaces, big holes, and big scars; in both PGS rats and ChABC rats showed lucent surfaces, small holes, and small scars; in PGS/ChABC rats showed the best. The expression of GAP‐43 and NF‐200 in the TSC region was hardly detected in the control rats, moderately detected in PGS or ChABC rats, and highly detected in PGS/ChABC rats. In conclusion, both PGS and ChABC alone could promote nerve regeneration and partially recover the movement function in TSC rats. A combination of PGS and ChABC resulted in augmented nerve regeneration and functional recovery. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1770–1777, 2018.
Prevascularization of 3D printed bone scaffolds by bioactive hydrogels and cell co‐culture
Authors: Kuss Mitchell A. , Wu Shaohua , Wang Ying , Untrauer Jason B. , Li Wenlong , Lim Jung Yul , Duan Bin
Published: September 2017

Vascularization is a fundamental prerequisite for large bone construct development and remains one of the main challenges of bone tissue engineering. Our current study presents the combination of 3D printing technique with a hydrogel‐based prevascularization strategy to generate prevascularized bone constructs. Human adipose derived mesenchymal stem cells (ADMSC) and human umbilical vein endothelial cells (HUVEC) were encapsulated within our bioactive hydrogels, and the effects of culture conditions on in vitro vascularization were determined. We further generated composite constructs by forming 3D printed polycaprolactone/hydroxyapatite scaffolds coated with cell‐laden hydrogels and determined how the co‐culture affected vascularization and osteogenesis. It was demonstrated that 3D co‐cultured ADMSC‐HUVEC generated capillary‐like networks within the porous 3D printed scaffold. The co‐culture systems promoted in vitro vascularization, but had no significant effects on osteogenesis. The prevascularized constructs were subcutaneously implanted into nude mice to evaluate the in vivo vascularization capacity and the functionality of engineered vessels. The hydrogel systems facilitated microvessel and lumen formation and promoted anastomosis of vascular networks of human origin with host murine vasculature. These findings demonstrate the potential of prevascularized 3D printed scaffolds with anatomical shape for the healing of larger bone defects. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1788–1798, 2018.
Longitudinal Effects of Single Hindlimb Radiation Therapy on Bone Strength and Morphology at Local and Contralateral Sites
Authors: Oest Megan E , Policastro Connor G , Mann Kenneth A , Zimmerman Nicholas D , Damron Timothy A
Published: September 2017

Radiation therapy (RTx) is associated with increased risk for late-onset fragility fractures in bone tissue underlying the radiation field. Bone tissue outside the RTx field is often selected as a “normal” comparator tissue in clinical assessment of fragility fracture risk, but the robustness of this comparison is limited by an incomplete understanding of the systemic effects of local radiotherapy. In this study, a mouse model of limited field irradiation was used to quantify longitudinal changes in local (irradiated) and systemic (non-irradiated) femurs with respect to bone density, morphology, and strength. BALB/cJ mice aged 12 weeks underwent unilateral hindlimb irradiation (4 × 5 Gy) or a sham procedure. Femurs were collected at endpoints of 4 days before treatment and at 0, 1, 2, 4, 8, 12, and 26 weeks post-treatment. Irradiated (RTx), Contralateral (non-RTx), and Sham (non-RTx) femurs were imaged by micro-computed tomography and mechanically tested in three-point bending. In both the RTx and Contralateral non-RTx groups, the longer-term (12- to 26-week) outcomes included trabecular resorption, loss of diaphyseal cortical bone, and decreased bending strength. Contralateral femurs generally followed an intermediate response compared with RTx femurs. Change also varied by anatomic compartment; post-RTx loss of trabecular bone was more profound in the metaphyseal than the epiphyseal compartment, and cortical bone thickness decreased at the mid-diaphysis but increased at the metaphysis. These data demonstrate that changes in bone quantity, density, and architecture occur both locally and systemically after limited field irradiation and vary by anatomic compartment. Furthermore, the severity and persistence of systemic bone damage after limited field irradiation suggest selection of control tissues for assessment of fracture risk or changes in bone density after radiotherapy may be challenging. © 2017 American Society for Bone and Mineral Research.
Spectroscopic investigations on the conformational changes of lysozyme effected by different sizes of N‐acetyl‐l‐cysteine‐capped CdTe quantum dots
Authors: Wu Qianqian , Wan Jingqiang , He Zhuo , Liu Rutao
Published: September 2017

The effect of N‐acetyl‐l‐cysteine‐capped CdTe quantum dots (NAC‐CdTe QDs) with different sizes on lysozyme was investigated by isothermal titration calorimetry (ITC), enzyme activity assays, and multi‐spectroscopic methods. ITC results proved that NAC‐CdTe QDs can spontaneously bind with lysozyme and hydrophobic force plays a major role in stabilizing QDs–lysozyme complex. Multi‐spectroscopic measurements revealed that NAC‐CdTe QDs caused strong quenching of the lysozyme's fluorescence in a size‐dependent quenching manner. Moreover, the changes of secondary structure and microenvironment in lysozyme caused by the NAC‐CdTe QDs were higher with a bigger size. The results of enzyme activity assays showed that the interaction between lysozyme and NAC‐CdTe QDs inhibited the activity of lysozyme and the inhibiting effect was in a size‐dependent manner. Based on these results, we conclude that NAC‐CdTe QDs with larger particle size had a larger impact on the structure and function of lysozyme.
Synthesis of 2‐amino‐3‐cyanopyridine derivatives and investigation of their carbonic anhydrase inhibition effects
Authors: Altundas Aliye , Gül Berna , Çankaya Murat , Atasever Ali , Gülçin İlhami
Published: September 2017

The conversion of carbon dioxide (CO2) and bicarbonate (HCO3−) to each other is very important for living metabolism. Carbonic anhydrase (CA, E.C.4.2.1.1), a metalloenzyme familly, catalyzes the interconversion of these ions (CO2 and HCO3−) and are very common in living organisms. In this study, a series of novel 2‐amino‐3‐cyanopyridines supported with some functional groups was synthesized and tested as potential inhibition effects against both cytosolic human CA I and II isoenzymes (hCA I and II) using by Sepharose‐4B‐l‐tyrosine‐sulfanilamide affinity chromatography. The structural elucidations of novel 2‐amino‐3‐cyanopyridines were achieved by NMR, IR, and elemental analyses. Ki values of the novel synthesized compounds were found in range of 2.84–112.44 μM against hCA I and 2.56–31.17 μM against hCA II isoenzyme. While compound 7d showed the best inhibition activity against hCA I (Ki: 2.84 μM), the compound 7b demonstrated the best inhibition profile against hCA II isoenzyme (Ki: 2.56 μM).
Levi's Lemma, pseudolinear drawings of , and empty triangles
Authors: Arroyo Alan , McQuillan Dan , Richter R. Bruce , Salazar Gelasio
Published: September 2017

There are three main thrusts to this article: a new proof of Levi's Enlargement Lemma for pseudoline arrangements in the real projective plane; a new characterization of pseudolinear drawings of the complete graph; and proofs that pseudolinear and convex drawings of have O and O(n2), respectively, empty triangles. All the arguments are elementary, algorithmic, and self‐contained.
Diagnostic performance of CT, gadoxetate disodium‐enhanced MRI, and PET/CT for the diagnosis of colorectal liver metastasis: Systematic review and meta‐analysis
Authors: Choi Sang Hyun , Kim So Yeon , Park Seong Ho , Kim Kyung Won , Lee Ja Youn , Lee Seung Soo , Lee Moon‐Gyu
Published: September 2017

Background

Imaging studies, including computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET), have an essential role in the detection and localization of colorectal liver metastasis (CRLM).

Purpose

To systematically determine the diagnostic accuracy of multidetector row CT (MDCT), gadoxetate disodium‐enhanced MRI, and PET/CT for diagnosing CRLM and the sources of heterogeneity between the reported results.

Study Type

Systematic review and meta‐analysis.

Subjects

In all, 2151 lesions in CT studies, 2301 lesions in MRI studies, 1846 lesions in PET/CT studies,

Field Strength

1.5T and 3.0T.

Assessment

We identified research studies that investigated MDCT, gadoxetate disodium‐enhanced MRI, and PET/CT to diagnose CRLM by performing a systematic search of PubMed MEDLINE and EMBASE. Study quality was assessed using Quality Assessment of Diagnostic Accuracy Studies (QUADAS‐2).

Statistical Tests

According to the types of imaging tests, study heterogeneity and the threshold effect were analyzed and the meta‐analytic summary of sensitivity and specificity were estimated. Meta‐regression analysis was performed to further investigate study heterogeneity.

Results

Of the 860 articles screened, we found 36 studies from 24 articles reporting a diagnosis of CRLM (11 CT studies, 12 MRI studies, and 13 PET/CT studies). The meta‐analytic summary sensitivity for CT, MRI, and PET/CT were 82.1% (95% confidence interval [CI], 74.0–88.1%), 93.1% (95% CI, 88.4–96.0%), and 74.1% (95% CI, 62.1–83.3%), respectively. The meta‐analytic summary specificity for CT, MRI, and PET/CT were 73.5% (95% CI, 53.7–86.9%), 87.3% (95% CI, 77.5–93.2%), and 93.9% (95% CI, 83.9–97.8%), respectively. There was no threshold effect in any of the imaging tests. Neoadjuvant chemotherapy significantly decreased the sensitivity of CT and MRI (P < 0.01), although it did not significantly affect the sensitivity of PET/CT. The study design, type of reference standard, and study quality also affected the diagnostic performances of imaging studies.

Data Conclusion

Despite the heterogeneous accuracy between studies, gadoxetate disodium‐enhanced MRI showed the highest sensitivity, and gadoxetate disodium‐enhanced MRI and PET/CT had similar specificities for diagnosing CRLM.

Level of Evidence: 3

Technical Efficacy: Stage 2

J. Magn. Reson. Imaging 2018;47:1237–1250.
ADC‐derived spatial features can accurately classify adnexal lesions
Authors: Fathi Kazerooni Anahita , Nabil Mahnaz , Haghighat Khah Hamidreza , Alviri Mohammadreza , Heidari‐Sooreshjaani Maryam , Gity Masoumeh , Malek Mahrooz , Saligheh Rad Hamidreza
Published: September 2017

Background

The role of quantitative apparent diffusion coefficient (ADC) maps in differentiating adnexal masses is unresolved.

Purpose/Hypothesis

To propose an objective diagnostic method devised based on spatial features for predicting benignity/malignancy of adnexal masses in ADC maps.

Study Type

Prospective.

Population

In all, 70 women with sonographically indeterminate and histopathologically confirmed adnexal masses (38 benign, 3 borderline, and 29 malignant) were considered for this study.

Field Strength/Sequence

Conventional and diffusion‐weighted magnetic resonance (MR) images (b‐values = 50, 400, 1000 s/mm2) were acquired on a 3T scanner.

Assessment

For each patient, two radiologists in consensus manually delineated lesion borders in whole ADC map volumes, which were consequently analyzed using spatial models (first‐order histogram [FOH], gray‐level co‐occurrence matrix [GLCM], run‐length matrix [RLM], and Gabor filters). Two independent radiologists were asked to identify the attributed (benign/malignant) classes of adnexal masses based on morphological features on conventional MRI.

Statistical Tests

Leave‐one‐out cross‐validated feature selection followed by cross‐validated classification were applied to the feature space to choose the spatial models that best discriminate benign from malignant adnexal lesions. Two schemes of feature selection/classification were evaluated: 1) including all benign and malignant masses, and 2) scheme 1 after excluding endometrioma, hemorrhagic cysts, and teratoma (14 benign, 29 malignant masses). The constructed feature subspaces for benign/malignant lesion differentiation were tested for classification of benign/borderline/malignant and also borderline/malignant adnexal lesions.

Results

The selected feature subspace consisting of RLM features differentiated benign from malignant adnexal masses with a classification accuracy of ∼92%. The same model discriminated benign, borderline, and malignant lesions with 87% and borderline from malignant with 100% accuracy. Qualitative assessment of the radiologists based on conventional MRI features reached an accuracy of 80%.

Data Conclusion

The spatial quantification methodology proposed in this study, which works based on cellular distributions within ADC maps of adnexal masses, may provide a helpful computer‐aided strategy for objective characterization of adnexal masses.

Level of Evidence: 1

Technical Efficacy: Stage 2

J. Magn. Reson. Imaging 2018;47:1061–1071.
Combined genotyping strategy reveals structural differences between Aspergillus flavus lineages from different habitats impacting human health
Authors: Baranyi Nikolett , Kocsubé Sándor , Jakšić Despot Daniela , Šegvić Klarić Maja , Szekeres András , Bencsik Ottó , Kecskeméti Anita , Manikandan Palanisamy , Tóth Beáta , Kredics László , Khaled Jamal M. , Alharbi Naiyf S. , Vágvölgyi Csaba , Varga János
Published: September 2017

Aspergillus flavus is a filamentous fungus which is widespread on agricultural products and also able to cause various human diseases. This species is frequently isolated from indoor air as well, furthermore, it is known as a common causal agent of keratomycosis, particularly in subtropical and tropical areas. It is also able to produce aflatoxins, one of the most carcinogenic mycotoxins which are harmful to animals and humans. In this study, 59 A. flavus isolates from four different habitats and 1 A. minisclerotigenes isolate were investigated. The isolates were identified and confirmed at the species level by the sequence analysis of a part of their calmodulin gene. Applying a combined analysis of UP‐PCR, microsatellite, and calmodulin sequence data, the four group of isolates formed separate clusters on the phylogenetic tree. Examining the distribution of mating type genes MAT1‐1 and MAT1‐2, a ratio of approximately 3:1 was determined, and no correlation was found between the carried mating type gene and the aflatoxin production capability. HPLC analysis revealed that none of the examined isolates collected from indoor air or maize in Central Europe were able to produce aflatoxins, while about half of the isolates from India produced these mycotoxins under the test conditions.
Photoluminescence of Diphenylalanine Peptide Nano/Microstructures: From Mechanisms to Applications
Authors: Gan Zhixing , Xu Hao
Published: September 2017

Diphenylalanine (Phe‐Phe, FF) molecules, which can self‐assemble into highly ordered nano/microstructures, have increasingly aroused intense interests due to their special optical properties. In this review, recent advances in photoluminescence (PL) of supramolecular architectures of FF‐based peptide and the underlying mechanisms are highlighted. Mainly deep ultraviolet emission at around 285 nm and/or blue emission at ≈450 nm are observed in various FF peptide structures and its derivatives, which are primarily interpreted by quantum confinement effects, shallow radiative traps, and electron delocalization via hydrogen bonds in β‐sheet structures. Furthermore, current applications of such fluorescent peptide nano/microstructures are also reviewed here, e.g., probing the number of water molecules confined in FF, temperature sensing, and visualization of deep ultraviolet beam. Yet, the PL mechanism is still under fierce debate and the application based on fluorescence is constantly under exploration. Thus, this review is endeavored to boost future explorations on the PL of the bioinspired FF peptide nano/microstructures.
Neighboring Structure Visualization on a Grid‐based Layout
Authors: Marcou G. , Horvath D. , Varnek A.
Published: September 2017

Here, we describe an algorithm to visualize chemical structures on a grid‐based layout in such a way that similar structures are neighboring. It is based on structure reordering with the help of the Hilbert Schmidt Independence Criterion, representing an empirical estimate of the Hilbert‐Schmidt norm of the cross‐covariance operator. The method can be applied to any layout of bi‐ or three‐dimensional shape. The approach is demonstrated on a set of dopamine D5 ligands visualized on squared, disk and spherical layouts.