bluuebunny/crossref_metadata_2025 huggingface dataset:
Resveratrol therapeutics combines both antimicrobial and immunomodulatory properties against respiratory infection by nontypeable Haemophilus influenzae
Authors: Euba Begoña , López-López Nahikari , Rodríguez-Arce Irene , Fernández-Calvet Ariadna , Barberán Montserrat , Caturla Nuria , Martí Sara , Díez-Martínez Roberto , Garmendia Junkal
Published: October 2017

The respiratory pathogen nontypeable Haemophilus influenzae (NTHi) is an important cause of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) that requires efficient treatments. A previous screening for host genes differentially expressed upon NTHi infection identified sirtuin-1, which encodes a NAD-dependent deacetylase protective against emphysema and is activated by resveratrol. This polyphenol concomitantly reduces NTHi viability, therefore highlighting its therapeutic potential against NTHi infection at the COPD airway. In this study, resveratrol antimicrobial effect on NTHi was shown to be bacteriostatic and did not induce resistance development in vitro. Analysis of modulatory properties on the NTHi-host airway epithelial interplay showed that resveratrol modulates bacterial invasion but not subcellular location, reduces inflammation without targeting phosphodiesterase 4B gene expression, and dampens β defensin-2 gene expression in infected cells. Moreover, resveratrol therapeutics against NTHi was evaluated in vivo on mouse respiratory and zebrafish septicemia infection model systems, showing to decrease NTHi viability in a dose-dependent manner and reduce airway inflammation upon infection, and to have a significant bacterial clearing effect without signs of host toxicity, respectively. This study presents resveratrol as a therapeutic of particular translational significance due to the attractiveness of targeting both infection and overactive inflammation at the COPD airway.
Spatially restricted loading of BRD2 at DNA double-strand breaks protects H4 acetylation domains and promotes DNA repair
Authors: Gursoy-Yuzugullu Ozge , Carman Chelsea , Price Brendan D.
Published: October 2017

The n-terminal tail of histone H4 recruits repair proteins, including 53BP1, to DNA double-strand breaks (DSB) and undergoes dynamic acetylation during DSB repair. However, how H4 acetylation (H4Ac) recruits repair proteins and reorganizes chromatin during DNA repair is unclear. Here, we show that the bromodomain protein BRD2 is recruited to DSBs. This recruitment requires binding of BRD2’s tandem bromodomains to H4Ac, which is generated at DSBs by the Tip60/KAT5 acetyltransferase. Binding of BRD2 to H4Ac protects the underlying acetylated chromatin from attack by histone deacetylases and allows acetylation to spread along the flanking chromatin. However, BRD2 recruitment is spatially restricted to a chromatin domain extending only 2 kb either side of the DSB, and BRD2 does not spread into the chromatin domains flanking the break. Instead, BRD2 facilitates recruitment of a second bromodomain protein, ZMYND8, which spreads along the flanking chromatin, but is excluded from the DSB region. This creates a spatially restricted H4Ac/BRD2 domain which reorganizes chromatin at DSBs, limits binding of the L3MBTL1 repressor and promotes 53BP1 binding, while limiting end-resection of DSBs. BRD2 therefore creates a restricted chromatin environment surrounding DSBs which facilitates DSB repair and which is framed by extensive ZMYND8 domains on the flanking chromatin.
Measurement of linear response functions in Nuclear Magnetic Resonance
Authors: Xin Tao , Pedernales Julen S. , Lamata Lucas , Solano Enrique , Long Gui-Lu
Published: October 2017

We measure multi-time correlation functions of a set of Pauli operators on a two-level system, which can be used to retrieve its associated linear response functions. The two-level system is an effective spin constructed from the nuclear spins of 1H atoms in a solution of 13C-labeled chloroform. Response functions characterize the linear response of the system to a family of perturbations, allowing us to compute physical quantities such as the magnetic susceptibility of the effective spin. We use techniques exported from quantum information to measure time correlations on the two-level system. This approach requires the use of an ancillary qubit encoded in the nuclear spins of the 13C atoms and a sequence of controlled operations. Moreover, we demonstrate the ability of such a quantum platform to compute time-correlation functions of arbitrary order, which relate to higher-order corrections of perturbative methods. Particularly, we show three-time correlation functions for arbitrary times, and we also measure time correlation functions at fixed times up to tenth order.
Spatial distribution of citizen science casuistic observations for different taxonomic groups
Authors: Tiago Patrícia , Ceia-Hasse Ana , Marques Tiago A. , Capinha César , Pereira Henrique M.
Published: October 2017

Opportunistic citizen science databases are becoming an important way of gathering information on species distributions. These data are temporally and spatially dispersed and could have limitations regarding biases in the distribution of the observations in space and/or time. In this work, we test the influence of landscape variables in the distribution of citizen science observations for eight taxonomic groups. We use data collected through a Portuguese citizen science database (biodiversity4all.org). We use a zero-inflated negative binomial regression to model the distribution of observations as a function of a set of variables representing the landscape features plausibly influencing the spatial distribution of the records. Results suggest that the density of paths is the most important variable, having a statistically significant positive relationship with number of observations for seven of the eight taxa considered. Wetland coverage was also identified as having a significant, positive relationship, for birds, amphibians and reptiles, and mammals. Our results highlight that the distribution of species observations, in citizen science projects, is spatially biased. Higher frequency of observations is driven largely by accessibility and by the presence of water bodies. We conclude that efforts are required to increase the spatial evenness of sampling effort from volunteers.
Smart patterned surfaces with programmable thermal emissivity and their design through combinatorial strategies
Authors: Athanasopoulos N. , Siakavellas N. J.
Published: October 2017

The emissivity of common materials remains constant with temperature variations, and cannot drastically change. However, it is possible to design its entire behaviour as a function of temperature, and to significantly alter the thermal emissivity of a surface through the combination of different patterns and materials. We show that smart patterned surfaces consisting of smaller structures (motifs) may be designed to respond uniquely through combinatorial strategies by transforming themselves. The smart surfaces can passively manipulate thermal radiation—without the use of electronics—because their modus operandi has already been programmed into their intrinsic characteristics; the environment provides the energy required for their activation. Each motif emits thermal radiation in a certain manner, as it changes its geometry; however, the spatial distribution of these motifs causes them to interact with each other. Therefore, their combination and interaction determine the global behaviour of the surfaces, thus enabling their a priori design. The emissivity behaviour is not random; it is determined by two fundamental parameters, namely the combination of orientations in which the motifs open (n-fold rotational symmetry) and the combination of materials (colours) on the motifs; these generate functions which fully determine the dependency of the emissivity on the temperature.
Buoyancy effects on the radiative magneto Micropolar nanofluid flow with double stratification, activation energy and binary chemical reaction
Authors: Ramzan M. , Ullah Naeem , Chung Jae Dong , Lu Dianchen , Farooq Umer
Published: October 2017

A mathematical model has been developed to examine the magneto hydrodynamic micropolar nanofluid flow with buoyancy effects. Flow analysis is carried out in the presence of nonlinear thermal radiation and dual stratification. The impact of binary chemical reaction with Arrhenius activation energy is also considered. Apposite transformations are engaged to transform nonlinear partial differential equations to differential equations with high nonlinearity. Resulting nonlinear system of differential equations is solved by differential solver method in Maple software which uses Runge-Kutta fourth and fifth order technique (RK45). To authenticate the obtained results, a comparison with the preceding article is also made. The evaluations are executed graphically for numerous prominent parameters versus velocity, micro rotation component, temperature, and concentration distributions. Tabulated numerical calculations of Nusselt and Sherwood numbers with respective well-argued discussions are also presented. Our findings illustrate that the angular velocity component declines for opposing buoyancy forces and enhances for aiding buoyancy forces by changing the micropolar parameter. It is also found that concentration profile increases for higher values of chemical reaction parameter, whereas it diminishes for growing values of solutal stratification parameter.
Molecular evidence of Chlamydia pecorum and arthropod-associated Chlamydiae in an expanded range of marsupials
Authors: Burnard Delaney , Huston Wilhelmina M. , Webb Jonathan K. , Jelocnik Martina , Reiss Andrea , Gillett Amber , Fitzgibbon Sean , Carver Scott , Carrucan Janine , Flanagan Cheyne , Timms Peter , Polkinghorne Adam
Published: October 2017

The order Chlamydiales are biphasic intracellular bacterial pathogens infecting humans and domesticated animals. Wildlife infections have also been reported, with the most studied example being Chlamydia pecorum infections in the koala, an iconic Australian marsupial. In koalas, molecular evidence suggests that spill-over from C. pecorum infected livestock imported into Australia may have had a historical or contemporary role. Despite preliminary evidence that other native Australian marsupials also carry C. pecorum, their potential as reservoirs of this pathogen and other Chlamydia-related bacteria (CRBs) has been understudied. Mucosal epithelial samples collected from over 200 native Australian marsupials of different species and geographic regions across Australia were PCR screened for Chlamydiales. Previously described and genetically distinct C. pecorum genotypes and a range of 16S rRNA genotypes sharing similarity to different CRBs in the broader Chlamydiales order were present. One 16S rRNA Chlamydiales genotype recently described in Australian ticks that parasitise native Australian marsupials was also identified. This study provides further evidence that chlamydial infections are widespread in native fauna and that detailed investigations are required to understand the influence these infections have on host species conservation, but also whether infection spill-over plays a role in their epidemiology.
ERV1 Overexpression in Myeloid Cells Protects against High Fat Diet Induced Obesity and Glucose Intolerance
Authors: Sima Corneliu , Montero Eduardo , Nguyen Daniel , Freire Marcelo , Norris Paul , Serhan Charles N. , Van Dyke Thomas E.
Published: October 2017

Non-resolving inflammation is a central pathologic component of obesity, insulin resistance, type 2 diabetes and associated morbidities. The resultant hyperglycemia is deleterious to the normal function of many organs and its control significantly improves survival and quality of life for patients with diabetes. Macrophages play critical roles in both onset and progression of obesity-associated insulin resistance. Here we show that systemic activation of inflammation resolution prevents from morbid obesity and hyperglycemia under dietary overload conditions. In gain-of-function studies using mice overexpressing the human resolvin E1 receptor (ERV1) in myeloid cells, monocyte phenotypic shifts to increased patrolling-to-inflammatory ratio controlled inflammation, reduced body weight gain and protected from hyperglycemia on high-fat diet. Administration of a natural ERV1 agonist, resolvin E1, recapitulated the pro-resolving actions gained by ERV1 overexpression. This protective metabolic impact is in part explained by systemic activation of resolution programs leading to increased synthesis of specialized pro-resolving mediators.
Deep-level defects in n-type GaAsBi alloys grown by molecular beam epitaxy at low temperature and their influence on optical properties
Authors: Gelczuk Łukasz , Kopaczek Jan , Rockett Thomas B. O. , Richards Robert D. , Kudrawiec Robert
Published: October 2017

Deep-level defects in n-type GaAs1−x
Bi
x
having 0 ≤ x ≤ 0.023 grown on GaAs by molecular beam epitaxy at substrate temperature of 378 °C have been injvestigated by deep level transient spectroscopy. The optical properties of the layers have been studied by contactless electroreflectance and photoluminescence. We find that incorporating Bi suppresses the formation of GaAs-like electron traps, thus reducing the total trap concentration in dilute GaAsBi layers by over two orders of magnitude compared to GaAs grown under the same conditions. In order to distinguish between Bi- and host-related traps and to identify their possible origin, we used the GaAsBi band gap diagram to correlate their activation energies in samples with different Bi contents. This approach was recently successfully applied for the identification of electron traps in n-type GaAs1−x
N
x
and assumes that the activation energy of electron traps decreases with the Bi (or N)-related downward shift of the conduction band. On the basis of this diagram and under the support of recent theoretical calculations, at least two Bi-related traps were revealed and associated with Bi pair defects, i.e. (VGa+BiGa)−/2− and (AsGa+BiGa)0/1−. In the present work it is shown that these defects also influence the photoluminescence properties of GaAsBi alloys.
S1P1 deletion differentially affects TH17 and Regulatory T cells
Authors: Eken Ahmet , Duhen Rebekka , Singh Akhilesh K. , Fry Mallory , Buckner Jane H. , Kita Mariko , Bettelli Estelle , Oukka Mohamed
Published: October 2017

Sphingosine-1 phosphate receptor 1 (S1P1) is critical for the egress of T and B cells out of lymphoid organs. Although S1P1 agonist fingolimod is currently used for the treatment of multiple sclerosis (MS) little is known how S1P1 signaling regulates Th17 and Treg cell homeostasis. To study the impact of S1P1 signaling on Th17 and Treg cell biology, we specifically deleted S1P1 in Th17 and Treg cells using IL-17A
Cre
and Foxp3
Cre
mice, respectively. Deletion of S1P1 in Th17 cells conferred resistance to experimental autoimmune encephalomyelitis (EAE). On the other hand, permanent deletion of S1P1 in Treg cells resulted in autoimmunity and acute deletion rendered mice more susceptible to EAE. Importantly, our study revealed that S1P1 not only regulated the egress of Treg cells out of lymphoid organs and subsequent non-lymphoid tissue distribution but also their phenotypic diversity. Most of the Treg cells found in S1P1-deficient mice as well as MS patients on fingolimod therapy had an activated phenotype and were more prone to apoptosis, thus converted to effector Treg. Our results provide novel insight into the functions of S1P1 and potential impact of long term fingolimod use on Th17 and Treg cell biology and general health in MS patients.
Biochemical mechanisms of dose-dependent cytotoxicity and ROS-mediated apoptosis induced by lead sulfide/graphene oxide quantum dots for potential bioimaging applications
Authors: Ayoubi Mahdi , Naserzadeh Parvaneh , Hashemi Mohammad Taghi , Reza Rostami Mohammad , Tamjid Elnaz , Tavakoli Mohammad Mahdi , Simchi Abdolreza
Published: October 2017

Colloidal quantum dots (CQD) have attracted considerable attention for biomedical diagnosis and imaging as well as biochemical analysis and stem cell tracking. In this study, quasi core/shell lead sulfide/reduced graphene oxide CQD with near infrared emission (1100 nm) were prepared for potential bioimaging applications. The nanocrystals had an average diameter of ~4 nm, a hydrodynamic size of ~8 nm, and a high quantum efficiency of 28%. Toxicity assay of the hybrid CQD in the cultured human mononuclear blood cells does not show cytotoxicity up to 200 µg/ml. At high concentrations, damage to mitochondrial activity and mitochondrial membrane potential (MMP) due to the formation of uncontrollable amounts of intracellular oxygen radicals (ROS) was observed. Cell membrane and Lysosome damage or a transition in mitochondrial permeability were also noticed. Understanding of cell-nanoparticle interaction at the molecular level is useful for the development of new fluorophores for biomedical imaging.
Rare-Earth Free Self-Activated Graphene Quantum Dots and Copper-Cysteamine Phosphors for Enhanced White Light-Emitting-Diodes under Single Excitation
Authors: Dai Wubin , Lei Yifeng , Xu Man , Zhao Pei , Zhang Zhanhui , Zhou Jia
Published: October 2017

Rare-earth (RE) based phosphors are attractive due to their potential applications. However, owing to the resource issue, these kinds of phosphors are expensive and costly. On the contrary, as for phosphor-convert white light-emitting-diodes (pc-WLEDs), a solution-processed tunable warm white emission LED composite is fabricated in this study under single excitation, with both RE free phosphors graphene quantum dots (GQDs) and Copper-Cysteamine (Cu-Cy). By using microwave-assisted wet-chemical method and with graphite as raw material, cold white fluorescence of the GQDs is obtained. Cu-Cy which shows intense photoluminescence in the red region has the structure where both the thio and amine groups connected with copper and forming cysteamine. Warm white light is achieved by mixing the two self-activated RE free phosphors at the weight ratio of 1: 1.7 under the excitation at 365 nm. The designed optimal LED device has the properties of CIE (x, y) = (0.341, 0.327), T = 4436 K, R = 87.9 EQE = 0.31%. The experimental results demonstrate that RE free phosphor(s) excited under a single chip can open up a new avenue to develop much lower device for warm WLEDs.
Eugenol inhibits oxidative phosphorylation and fatty acid oxidation via downregulation of c-Myc/PGC-1β/ERRα signaling pathway in MCF10A-ras cells
Authors: Yan Xianxin , Zhang Guijuan , Bie Fengjie , Lv Yanhong , Ma Yi , Ma Min , Wang Yurong , Hao Xiaoqian , Yuan Naijun , Jiang Xuefeng
Published: October 2017

Alteration in cellular energy metabolism plays a critical role in the development and progression of cancer. Targeting metabolic pathways for cancer treatment has been investigated as potential preventive or therapeutic methods. Eugenol (Eu), a major volatile constituent of clove essential oil mainly obtained from Syzygium, has been reported as a potential chemopreventive drug. However, the mechanism by which Eu regulates cellular energy metabolism is still not well defined. This study was designed to determine the effect of Eu on cellular energy metabolism during early cancer progression employing untransformed and H-ras oncogene transfected MCF10A human breast epithelial cells. Eu showed dose-dependent selective cytotoxicity toward MCF10A-ras cells but exhibited no apparent cytotoxicity in MCF10A cells. Treatment with Eu also significantly reduced intracellular ATP levels in MCF10A-ras cells but not in MCF10A cells. This effect was mediated mainly through inhibiting oxidative phosphorylation (OXPHOS) complexs and the expression of fatty acid oxidation (FAO) proteins including PPARα, MCAD and CPT1C by downregulating c-Myc/PGC-1β/ERRα pathway and decreasing oxidative stress in MCF10A-ras cells. These results indicate a novel mechanism involving the regulation of cellular energy metabolism by which Eu may prevent breast cancer progression.
DFT investigation of the interaction between single-walled carbon nanotubes and fluorene-based conjugated oligomers
Authors: Khan Mohammad Zahidul H. , Alrawashdeh Ahmad I. , Aljohani Suad , Zhao Yuming , Lagowski Jolanta B.
Published: October 2017

Using DFT computations we study the interactions between carbon nanotubes and conjugated oligomers that are important for the understanding of the dispersion of carbon nanotubes.
Design of nanocomposites with cobalt encapsulated in the zeolite micropores for selective synthesis of isoparaffins in Fischer–Tropsch reaction
Authors: Carvalho Alexandre , Marinova Maya , Batalha Nuno , Marcilio Nilson R. , Khodakov Andrei Y. , Ordomsky Vitaly V.
Published: October 2017

A new strategy for the synthesis of metal–zeolite nanocomposite materials containing metal nanoparticles only in the zeolite pores is proposed.
Sludge concentration, shear rate and nanoparticle size determine silver nanoparticle removal during wastewater treatment
Authors: Cornelis G. , Forsberg-Grivogiannis A. M. , Sköld N. P. , Rauch S. , Perez-Holmberg J.
Published: October 2017

Wastewater treatment (WWT) is generally efficient in removing nanoparticles (NPs) from sewage effluent, but the variety in removal rates has not yet been explained.
A new procedure to obtain ε-caprolactam catalyzed by a guanidinium salt
Authors: Fernández-Stefanuto V. , Verdía P. , Tojo E.
Published: October 2017

A new procedure to prepare ε-caprolactam by the Beckmann rearrangement of cyclohexanone oxime is described.
Self-powered hydrogels induced by ion transport
Authors: Shi Zhijun , Zhao Weiwei , Li Sixiang , Yang Guang
Published: October 2017

Electroactive hydrogels are needed to enable stretchable electronics because of their flexible mechanical characteristics and electrical conductive properties.
Compact plasmonic optical biosensors based on nanostructured gradient index lenses integrated into microfluidic cells
Authors: Horrer A. , Haas J. , Freudenberger K. , Gauglitz G. , Kern D. P. , Fleischer M.
Published: October 2017

Compact sensors for the detection of biomolecules were developed by combining plasmonic nanostructures with gradient-index lenses.
Enhancement of charge transfer between graphene and donor–π-acceptor molecule for ultrahigh sensing performance
Authors: Pei Wenle , Zhang Tingting , Wang Yao , Chen Zhuo , Umar Ahmad , Li Hao , Guo Wei
Published: October 2017

Donor–π-acceptor structural molecule ANS modified reduced graphene oxide (ANS-rGO) exhibits ultrahigh sensing performance.
Influence of supporting amorphous carbon film thickness on measured strain variation within a nanoparticle
Authors: Settem Manoj , Rajak Piu , Islam Mahabul , Bhattacharyya Somnath
Published: October 2017

Supporting amorphous carbon film thickness introduces an artefact in measured strain variation within a nanoparticle using HRTEM images.
Redox-triggered activation of nanocarriers for mitochondria-targeting cancer chemotherapy
Authors: Zhou Wei , Yu Hui , Zhang Liu-Jie , Wu Bo , Wang Cai-Xia , Wang Qian , Deng Kai , Zhuo Ren-Xi , Huang Shi-Wen
Published: October 2017

The mitochondria-targeting of lipid–polymer hybrid nanoparticles can be activated by a redox-signal in cancer cells for highly efficient cancer chemotherapy.
Diversity-driven and facile 1,3-dipolar cycloaddition to access dispirooxindole-imidazolidine scaffolds
Authors: Qian Yu-Lun , Xia Peng-Ju , Li Jun , Zhao Qing-Lan , Xiao Jun-An , Xiang Hao-yue , Yang Hua
Published: October 2017

Diversity-driven three-component 1,3-dipolar cycloaddition of isatin, amino acid and isatin-derived ketimine was developed to facilely assemble dispirooxindole-imidazolidine skeletons bearing vicinal quaternary carbon centers.
A new approach for authentication of four ginseng herbs and their related products based on the simultaneous quantification of 19 ginseng saponins by UHPLC-TOF/MS coupled with OPLS-DA
Authors: Huang Bao-ming , Chen Ting-bo , Xiao Sheng-yuan , Zha Qing-lin , Luo Pei , Wang Ying-ping , Cui Xiu-ming , Liu Liang , Zhou Hua
Published: October 2017

The discrimination of the four ginseng herbs and their related products using 19 bioactive compounds.
Influence of rhodium content on the behavior of Rh/SiO2–Al2O3catalysts for selective ring opening of decalin
Authors: D'Ippolito Silvana A. , Pirault-Roy Laurence , Especel Catherine , Epron Florence , Pieck Carlos L.
Published: October 2017

Decalin ring-opening is favored on Rh/SiO2–Al2O3bifunctional catalyst with an optimized acid/metal balance.
Configuration and stability of naturally occurring all-cis-tetrahydrofuran lignans from Piper solmsianum
Authors: Ramos Clécio S. , Linnert Harrald V. , de Moraes Marcilio M. , do Amaral João H. , Yamaguchi Lydia F. , Kato Massuo J.
Published: October 2017

First occurrence of all-cishexamethoxy-tetrahydrofuran lignans1aand1b, which are 6.5 kcal mol−1less stable than the all-transisomer grandisin (2a).
Clausoxamine, an alkaloid possessing a 1,3-oxazine-4-one ring from the seeds of Clausena lansium and the anti-obesity effect of lansiumamide B
Authors: Huang Li , Li Dan , Xu Yun-Shao , Feng Zhe-Ling , Meng Fan-Chen , Zhang Qing-Wen , Gan Li-She , Lin Li-Gen
Published: October 2017

One alkaloid with an unprecedented skeleton and one alkaloid with anti-obesity effect were isolated from the seeds ofClausena lansium.
HOMO inversion as a strategy for improving the light-absorption properties of Fe(ii) chromophores
Authors: Mukherjee Sriparna , Torres David E. , Jakubikova Elena
Published: October 2017

Substitution of π-conjugated donor groups onto the polypyridine ligands in Fe(ii) complexes inverts the HOMO character and improves the light-absorption.
Free energy calculations for rings and chains formed by dipolar hard spheres
Authors: Ronti Michela , Rovigatti Lorenzo , Tavares José M. , Ivanov Alexey O. , Kantorovich Sofia S. , Sciortino Francesco
Published: October 2017

A numerical approach to calculate the free energies of DHS particles in chains and rings, exploring the unknown low-T region of the phase diagram of DHS.
Engineering Co9S8/WS2array films as bifunctional electrocatalysts for efficient water splitting
Authors: Peng Shengjie , Li Linlin , Zhang Jia , Tan Teck Leong , Zhang Tianran , Ji Dongxiao , Han Xiaopeng , Cheng Fangyi , Ramakrishna Seeram
Published: October 2017

Hierarchical Co9S8/WS2fabricated by a hydrothermal–sulfurization–hybridization process is demonstrated to exhibit high electrocatalytic activity and stability for water splitting, making the catalyst one of the best bifunctional catalysts for the overall water splitting reaction.
Mimicking muscle fiber structure and function through electromechanical actuation of electrospun silk fiber bundles
Authors: Severt S. Y. , Maxwell S. L. , Bontrager J. S. , Leger J. M. , Murphy A. R.
Published: October 2017

Fiber bundles composed of silk and conducting polymers undergo linear actuation, thus mimicking the structure and contractile function of muscles.
Fabrication of multifunctional ferric oxide nanoparticles for tumor-targeted magnetic resonance imaging and precise photothermal therapy with magnetic field enhancement
Authors: Liu Jiaxin , Chen Hongda , Fu Yu , Li Xiaodong , Chen Yixin , Zhang Huimao , Wang Zhenxin
Published: October 2017

Fe2O3@PDA-affibody integrates T2-weighted magnetic resonance imaging (MRI), tumor-targeting, and magnetic field (MF)-enhanced photothermal therapy (PTT) functionalities into an all-in-one system.
Improved performance of pure formamidinium lead iodide perovskite light-emitting diodes by moisture treatment
Authors: Ma Fusheng , Li Nan , Li Jiangwei , Jia Zhen , Xue Jie , Wang Liduo , Qiao Juan
Published: October 2017

Combining chloroform solvent engineering and moisture exposure led to an increase in the EQE from 0.03% up to 1.20% of perovskite LEDs based on pure FAPbI3 films.
Structural complexity in the KCTD family of Cullin3-dependent E3 ubiquitin ligases
Authors: Pinkas Daniel M. , Sanvitale Caroline E. , Bufton Joshua C. , Sorrell Fiona J. , Solcan Nicolae , Chalk Rod , Doutch James , Bullock Alex N.
Published: September 2017

Members of the potassium channel tetramerization domain (KCTD) family are soluble non-channel proteins that commonly function as Cullin3 (Cul3)-dependent E3 ligases. Solution studies of the N-terminal BTB domain have suggested that some KCTD family members may tetramerize similarly to the homologous tetramerization domain (T1) of the voltage-gated potassium (Kv) channels. However, available structures of KCTD1, KCTD5 and KCTD9 have demonstrated instead pentameric assemblies. To explore other phylogenetic clades within the KCTD family, we determined the crystal structures of the BTB domains of a further five human KCTD proteins revealing a rich variety of oligomerization architectures, including monomer (SHKBP1), a novel two-fold symmetric tetramer (KCTD10 and KCTD13), open pentamer (KCTD16) and closed pentamer (KCTD17). While these diverse geometries were confirmed by small-angle X-ray scattering (SAXS), only the pentameric forms were stable upon size-exclusion chromatography. With the exception of KCTD16, all proteins bound to Cul3 and were observed to reassemble in solution as 5 : 5 heterodecamers. SAXS data and structural modelling indicate that Cul3 may stabilize closed BTB pentamers by binding across their BTB–BTB interfaces. These extra interactions likely also allow KCTD proteins to bind Cul3 without the expected 3-box motif. Overall, these studies reveal the KCTD family BTB domain to be a highly versatile scaffold compatible with a range of oligomeric assemblies and geometries. This observed interface plasticity may support functional changes in regulation of this unusual E3 ligase family.
Evolution of allosteric regulation in chorismate mutases from early plants
Authors: Kroll Kourtney , Holland Cynthia K. , Starks Courtney M. , Jez Joseph M.
Published: September 2017

Plants, fungi, and bacteria synthesize the aromatic amino acids: l-phenylalanine, l-tyrosine, and l-tryptophan. Chorismate mutase catalyzes the branch point reaction of phenylalanine and tyrosine biosynthesis to generate prephenate. In Arabidopsis thaliana, there are two plastid-localized chorismate mutases that are allosterically regulated (AtCM1 and AtCM3) and one cytosolic isoform (AtCM2) that is unregulated. Previous analysis of plant chorismate mutases suggested that the enzymes from early plants (i.e. bryophytes/moss, lycophytes, and basal angiosperms) formed a clade distinct from the isoforms found in flowering plants; however, no biochemical information on these enzymes is available. To understand the evolution of allosteric regulation in plant chorismate mutases, we analyzed a basal lineage of plant enzymes homologous to AtCM1 based on sequence similarity. The chorismate mutases from the moss/bryophyte Physcomitrella patens (PpCM1 and PpCM2), the lycophyte Selaginella moellendorffii (SmCM), and the basal angiosperm Amborella trichopoda (AmtCM1 and AmtCM2) were characterized biochemically. Tryptophan was a positive effector for each of the five enzymes examined. Histidine was a weak positive effector for PpCM1 and AmtCM1. Neither tyrosine nor phenylalanine altered the activity of SmCM; however, tyrosine was a negative regulator of the other four enzymes. Phenylalanine down-regulates both moss enzymes and AmtCM2. The 2.0 Å X-ray crystal structure of PpCM1 in complex with the tryptophan identified the allosteric effector site and reveals structural differences between the R- (more active) and T-state (less active) forms of plant chorismate mutases. Molecular insight into the basal plant chorismate mutases guides our understanding of the evolution of allosteric regulation in these enzymes.
Solid-phase supported design of carriers for therapeutic nucleic acid delivery
Authors: Krhac Levacic Ana , Morys Stephan , Wagner Ernst
Published: September 2017

Nucleic acid molecules are important therapeutic agents in the field of antisense oligonucleotide, RNA interference, and gene therapies. Since nucleic acids are not able to cross cell membranes and enter efficiently into cells on their own, the development of efficient, safe, and precise delivery systems is the crucial challenge for development of nucleic acid therapeutics. For the delivery of nucleic acids to their intracellular site of action, either the cytosol or the nucleus, several extracellular and intracellular barriers have to be overcome. Multifunctional carriers may handle the different special requirements of each barrier. The complexity of such macromolecules however poses a new hurdle in medical translation, which is the chemical production in reproducible and well-defined form. Solid-phase assisted synthesis (SPS) presents a solution for this challenge. The current review provides an overview on the design and SPS of precise sequence-defined synthetic carriers for nucleic acid cargos.
Lack of mitochondrial ferritin aggravated neurological deficits via enhancing oxidative stress in a traumatic brain injury murine model
Authors: Wang Ligang , Wang Libo , Dai Zhibo , Wu Pei , Shi Huaizhang , Zhao Shiguang
Published: September 2017

Oxidative stress has been strongly implicated in the pathogenesis of traumatic brain injury (TBI). Mitochondrial ferritin (Ftmt) is reported to be closely related to oxidative stress. However, whether Ftmt is involved in TBI-induced oxidative stress and neurological deficits remains unknown. In the present study, the controlled cortical impact model was established in wild-type and Ftmt knockout mice as a TBI model. The Ftmt expression, oxidative stress, neurological deficits, and brain injury were measured. We found that Ftmt expression was gradually decreased from 3 to 14 days post-TBI, while oxidative stress was gradually increased, as evidenced by reduced GSH and superoxide dismutase levels and elevated malondialdehyde and nitric oxide levels. Interestingly, the extent of reduced Ftmt expression in the brain was linearly correlated with oxidative stress. Knockout of Ftmt significantly exacerbated TBI-induced oxidative stress, intracerebral hemorrhage, brain infarction, edema, neurological severity score, memory impairment, and neurological deficits. However, all these effects in Ftmt knockout mice were markedly mitigated by pharmacological inhibition of oxidative stress using an antioxidant, N-acetylcysteine. Taken together, these results reveal an important correlation between Ftmt and oxidative stress after TBI. Ftmt deficiency aggravates TBI-induced brain injuries and neurological deficits, which at least partially through increasing oxidative stress levels. Our data suggest that Ftmt may be a promising molecular target for the treatment of TBI.
Eukaryotic-type serine/threonine kinase mediated phosphorylation at Thr169 perturbs mycobacterial guanylate kinase activity
Authors: S. Yadav Ghanshyam , K. Ravala Sandeep , Kachhap Sangita , Thakur Meghna , Roy Abhishek , Singh Balvinder , Karthikeyan Subramanian , K. Chakraborti Pradip
Published: September 2017

Guanylate kinase is an essential and conserved enzyme in nucleotide biosynthetic pathway that transfers phosphoryl group of ATP to GMP for yielding GDP. Here, we report the phosphorylation of guanylate kinase from Mycobacterium tuberculosis (mGmk) by eukaryotic-type Ser/Thr kinase, PknA. Mass spectrometric studies identified Thr101 and Thr169 as phosphorylatable residues in mGmk. To evaluate the significance of phosphorylation in these threonines, two point (T101A and T169A) and one double (T101A-T169A) mutants were generated. The kinase assay with these mutant proteins revealed the major contribution of Thr169 compared with Thr101 in the phosphorylation of mGmk. Kinetic analysis indicated that p-mGmk was deficient in its enzymatic activity compared with that of its un-phosphorylated counterpart. Surprisingly, its phosphoablated (T169A) as well as phosphomimic (T169E) variants exhibited decreased activity as was observed with p-mGmk. Structural analysis suggested that phosphorylation of Thr169 might affect its interaction with Arg166, which is crucial for the functioning of mGmk. In fact, the R166A and R166K mutant proteins displayed a drastic decrease in enzymatic activity compared with that of the wild-type mGmk. Molecular dynamics (MD) studies of mGmk revealed that upon phosphorylation of Thr169, the interactions of Arg165/Arg166 with Glu158, Asp121 and residues of the loop in GMP-binding domain are perturbed. Taken together, our results illuminate the mechanistic insights into phosphorylation-mediated modulation of the catalytic activity of mGmk.
Chronic cerebral hypoperfusion: a key mechanism leading to vascular cognitive impairment and dementia. Closing the translational gap between rodent models and human vascular cognitive impairment and dementia
Authors: Duncombe Jessica , Kitamura Akihiro , Hase Yoshiki , Ihara Masafumi , Kalaria Raj N. , Horsburgh Karen
Published: September 2017

Increasing evidence suggests that vascular risk factors contribute to neurodegeneration, cognitive impairment and dementia. While there is considerable overlap between features of vascular cognitive impairment and dementia (VCID) and Alzheimer’s disease (AD), it appears that cerebral hypoperfusion is the common underlying pathophysiological mechanism which is a major contributor to cognitive decline and degenerative processes leading to dementia. Sustained cerebral hypoperfusion is suggested to be the cause of white matter attenuation, a key feature common to both AD and dementia associated with cerebral small vessel disease (SVD). White matter changes increase the risk for stroke, dementia and disability. A major gap has been the lack of mechanistic insights into the evolution and progress of VCID. However, this gap is closing with the recent refinement of rodent models which replicate chronic cerebral hypoperfusion. In this review, we discuss the relevance and advantages of these models in elucidating the pathogenesis of VCID and explore the interplay between hypoperfusion and the deposition of amyloid β (Aβ) protein, as it relates to AD. We use examples of our recent investigations to illustrate the utility of the model in preclinical testing of candidate drugs and lifestyle factors. We propose that the use of such models is necessary for tackling the urgently needed translational gap from preclinical models to clinical treatments.
Fuzzy disturbance observer‐based dynamic surface control for air‐breathing hypersonic vehicle with variable geometry inlets
Authors: Dou Liqian , Su Peihua , Zong Qun , Ding Zhengtao
Published: September 2017

For an air‐breathing hypersonic vehicle with a variable geometry inlet (AHV‐VGI), a movable translating cowl is used to track the shock on lip conditions to capture enough air mass flow, which can extend the velocity range and be favourable to the acceleration and manoeuvring flight. The authors firstly establish longitudinal dynamics for AHV‐VGI, and consider the lumped disturbances which include the unknown external disturbance, the parameter uncertainties and the uncertainty parts introduced by translating cowl. Then, the dynamic surface control strategy based on a fuzzy disturbance observer (FDO) is proposed for AHV‐VGI control. The control process for AHV‐VGI is divided into two subsystems. For each subsystem, a sliding mode controller is designed, and FDOs are adopted to compensate the lumped disturbances, which can render the disturbance estimate errors convergent. Numerical simulations are presented to illustrate the effectiveness of the proposed method and the advantages of translating cowl.
Target tracking approach via quantum genetic algorithm
Authors: Jin Zefenfen , Hou Zhiqiang , Yu Wangsheng , Wang Xin
Published: September 2017

Aiming at an efficient feature match and similarity search in visual tracking, this study proposes a tracking algorithm based on quantum genetic algorithm. Therein, the global optimisation ability of quantum genetic algorithm is utilised. In the framework of quantum genetic algorithm, the positions of pixels are taken as individuals in population, while scale‐invariant feature transform and colour features are taken as target model. Via defining the objective function, individual's fitness values can be measured. Visual tracking is realised when the pixel point with the biggest fitness value is searched and its corresponding position is returned. The experiment results show that the tracking algorithm the authors proposed performs more efficiently when it is compared with the state‐of‐the‐art tracking algorithms.
Investigation of an optically induced superstrate plasma for tuning microstrip antennas
Authors: Gamlath Chris D. , Collett Michael A. , Pang Weiran , Benton David M. , Cryan Martin J.
Published: September 2017

Optically induced electron–hole plasmas in silicon are used to perform radiation pattern tuning. The antenna is a slot loaded microstrip patch and the effect of illumination is shown to produce beam switching in the radiation patterns of certain modes while other modes are left unaffected. The structure is specifically designed to make the best use of currently available miniature laser sources to form a compact tunable package. Modelled and measured results for tuning of the radiation patterns and frequency response are presented. The effect of the losses incurred by the plasma along with the losses in the optically transparent ground plane are quantified in both simulation and measurement. This forms the basis for designing other types of optically tunable miniature antennas based on the structure presented.
Remaining useful life estimation without needing for prior knowledge of the degradation features
Authors: Benmoussa Samir , Djeziri Mohand Arab
Published: October 2017

This study deals with a hybrid method for the estimation of the remaining useful life (RUL) that does not require prior knowledge on the degradation phenomena, as the lack of information about the process of degradation is one of the main issues in the theory of fault prognosis of dynamic systems. The proposed method uses a dynamic model for the generation of fault indicators based on the principle of analytical redundancy, and the generation of a database by simulating the normal and faulty operations. Then, a data‐driven method is used to identify a cluster for each operating state. Taking into account uncertainties allows the generation of normal operation thresholds, which govern the launch of a kinematic model based on the calculation of the Euclidean distance for RUL estimation. The developed method is applied with three of the most used methods in literature, to a mechanical transmission system for the estimation of the remaining time before the breakage of the drive belt. The obtained results are discussed and evaluated with appropriate metrics in order to demonstrate the effectiveness of the proposed approach.
Molecular dynamics simulation of nickel‐coated graphene bending
Authors: Katin Konstantin P. , Prudkovskiy Vladimir S. , Maslov Mikhail M.
Published: September 2017

The work presents a force field molecular dynamics study of nickel‐coated graphene sheet bending at temperatures 300 and 1300 K. Nickel film is represented by nickel atoms located above the centres of carbon hexagons. Parameters for carbon–nickel interaction are fitted with regard to the accurate density functional calculations. Unstrained or flat configuration of the nickel–graphene system is found to be energetically unfavourable for the considered temperatures. Two types of curvatures are taken into account. Positive curvature is characterised by the nickel atoms located closer to the bending axis than the carbon ones, and negative curvature corresponds to the reverse atomic positions. It is found that the equilibrium radius for the curved nickel–graphene complex with the negative curvature is less than the corresponding value for the positive one. However, in both cases the equilibrium curvature radius of nickel‐coated graphene is of the order of several nanometres. It is shown that both temperature and bending directions (zigzag and armchair) weakly affect the bending energy and do not change the equilibrium radius. Bending behaviour of the system is defined by the carbon–nickel interaction rather than the individual properties of isolated graphene and nickel films.
What is the Milky Way outer halo made of?
Authors: Battaglia G. , North P. , Jablonka P. , Shetrone M. , Minniti D. , Díaz M. , Starkenburg E. , Savoy M.
Published: October 2017

In a framework where galaxies form hierarchically, extended stellar haloes are predicted to be an ubiquitous feature around Milky Way-like galaxies and to consist mainly of the shredded stellar component of smaller galactic systems. The type of accreted stellar systems are expected to vary according to the specific accretion and merging history of a given galaxy, and so is the fraction of stars formed in situ versus accreted. Analysis of the chemical properties of Milky Way halo stars out to large Galactocentric radii can provide important insights into the properties of the environment in which the stars that contributed to the build-up of different regions of the Milky Way stellar halo formed. In this work we focus on the outer regions of the Milky Way stellar halo, by determining chemical abundances of halo stars with large present-day Galactocentric distances, >15 kpc. The data-set we acquired consists of high resolution HET/HRS, Magellan/MIKE and VLT/UVES spectra for 28 red giant branch stars covering a wide metallicity range, −3.1 ≲ [Fe/H] ≲−0.6. We show that the ratio of α-elements over Fe as a function of [Fe/H] for our sample of outer halo stars is not dissimilar from the pattern shown by MW halo stars from solar neighborhood samples. On the other hand, significant differences appear at [Fe/H] ≳−1.5 when considering chemical abundance ratios such as [Ba/Fe], [Na/Fe], [Ni/Fe], [Eu/Fe], [Ba/Y]. Qualitatively, this type of chemical abundance trends are observed in massive dwarf galaxies, such as Sagittarius and the Large Magellanic Cloud. This appears to suggest a larger contribution in the outer halo of stars formed in an environment with high initial star formation rate and already polluted by asymptotic giant branch stars with respect to inner halo samples.
Patellofemoral Arthroplasty: Current Concepts and Review of the Literature
Authors: Pisanu Gabriele , Rosso Federica , Bertolo Corrado , Dettoni Federico , Blonna Davide , Bonasia Davide , Rossi Roberto
Published: October 2017

Patellofemoral osteoarthritis (PFOA) can be associated with anterior knee pain, stiffness, and functional impairment. Some authors report that PFOA affects approximately 9% of patients older than 40 years with a greater prevalence in females. Etiology of PFOA is multifactorial and is related to the presence of abnormal stresses at the PF joint due to knee- and patient-related factors. The need for a joint preserving treatment by isolated replacement of the injured compartment of the knee led to the development of PF arthroplasty (PFA). When a correct PF replacement is performed, PFA preserves physiologic tibiofemoral joint, thus allowing patients for a rapid recovery with a high satisfaction. The outcomes for PFA are quite variable with a trend toward good to excellent results, mainly owing to the improvement in surgical techniques, patient selection, and implant design. The development of the second generation of PFA improved the outcomes, which is attributed to the different trochlear designs. Recently, encouraging results have been provided by the association of PFA and unicompartmental knee arthroplasty (UKA). In many studies, the main cause of PFA failure is progression of tibiofemoral OA. The aim of this brief review of literature is to summarize the clinical features, indications and contraindications, surgical techniques, complications, and outcomes of PFA.