bluuebunny/crossref_metadata_2025 huggingface dataset:
Few-photon color imaging using energy-dispersive superconducting transition-edge sensor spectrometry
Authors: Niwa Kazuki , Numata Takayuki , Hattori Kaori , Fukuda Daiji
Published: April 2017

Highly sensitive spectral imaging is increasingly being demanded in bioanalysis research and industry to obtain the maximum information possible from molecules of different colors. We introduce an application of the superconducting transition-edge sensor (TES) technique to highly sensitive spectral imaging. A TES is an energy-dispersive photodetector that can distinguish the wavelength of each incident photon. Its effective spectral range is from the visible to the infrared (IR), up to 2800 nm, which is beyond the capabilities of other photodetectors. TES was employed in this study in a fiber-coupled optical scanning microscopy system, and a test sample of a three-color ink pattern was observed. A red–green–blue (RGB) image and a near-IR image were successfully obtained in the few-incident-photon regime, whereas only a black and white image could be obtained using a photomultiplier tube. Spectral data were also obtained from a selected focal area out of the entire image. The results of this study show that TES is feasible for use as an energy-dispersive photon-counting detector in spectral imaging applications.
Investigation of ac-magnetic field stimulated nanoelectroporation of magneto-electric nano-drug-carrier inside CNS cells
Authors: Kaushik Ajeet , Nikkhah-Moshaie Roozbeh , Sinha Raju , Bhardwaj Vinay , Atluri Venkata , Jayant Rahul Dev , Yndart Adriana , Kateb Babak , Pala Nezih , Nair Madhavan
Published: April 2017

In this research, we demonstrate cell uptake of magneto-electric nanoparticles (MENPs) through nanoelectroporation (NEP) using alternating current (ac)-magnetic field stimulation. Uptake of MENPs was confirmed using focused-ion-beam assisted transmission electron microscopy (FIB-TEM) and validated by a numerical simulation model. The NEP was performed in microglial (MG) brain cells, which are highly sensitive for neuro-viral infection and were selected as target for nano-neuro-therapeutics. When the ac-magnetic field optimized (60 Oe at 1 kHz), MENPs were taken up by MG cells without affecting cell health (viability > 92%). FIB-TEM analysis of porated MG cells confirmed the non-agglomerated distribution of MENPs inside the cell and no loss of their elemental and crystalline characteristics. The presented NEP method can be adopted as a part of future nanotherapeutics and nanoneurosurgery strategies where a high uptake of a nanomedicine is required for effective and timely treatment of brain diseases.
Amide proton transfer magnetic resonance imaging in detecting intracranial hemorrhage at different stages: a comparative study with susceptibility weighted imaging
Authors: Ma Xiaoyue , Bai Yan , Lin Yusong , Hong Xiaohua , Liu Taiyuan , Ma Lun , Haacke E Mark , Zhou Jinyuan , Wang Jian , Wang Meiyun
Published: April 2017

Amide proton transfer (APT) imaging is a noninvasive molecular magnetic resonance imaging (MRI) technique based on the chemical exchange-dependent saturation transfer mechanism. The purpose of this study was to investigate the diagnostic performance of APT MRI in detecting intracranial hemorrhage (ICH) at hyperacute, acute and subacute stages by comparing with susceptibility weighted imaging (SWI). APT MRI and SWI were performed on 33 included patients with ICH by using a 3-T MRI unit. A two-sided Mann-WhitneyUtest was used to detect differences in APT-weighted (APTw) and SWI signal intensities of ICH at hyperacute, acute and subacute stages. Receiver operating characteristic analysis was used to assess the diagnostic utilities of APT MRI and SWI. Our results showed that APT MRI could detect ICH at hyperacute, acute and subacute stages. Therefore, APTw signal intensity may serve as a reliable, noninvasive imaging biomarker for detecting ICH at hyperacute, acute and subacute stages. Moreover, APT MRI could provide additional information for the ICH compared with SWI.
Ovine multiparity is associated with diminished vaginal muscularis, increased elastic fibres and vaginal wall weakness: implication for pelvic organ prolapse
Authors: Emmerson Stuart , Young Natharnia , Rosamilia Anna , Parkinson Luke , Edwards Sharon L. , Vashi Aditya V. , Davies-Tuck Miranda , White Jacinta , Elgass Kirstin , Lo Camden , Arkwright John , Werkmeister Jerome A. , Gargett Caroline E.
Published: April 2017

Pelvic Organ Prolapse (POP) is a major clinical burden affecting 25% of women, with vaginal delivery a major contributing factor. We hypothesised that increasing parity weakens the vagina by altering the extracellular matrix proteins and smooth muscle thereby leading to POP vulnerability. We used a modified POP-quantification (POP-Q) system and a novel pressure sensor to measure vaginal wall weakness in nulliparous, primiparous and multiparous ewes. These measurements were correlated with histological, biochemical and biomechanical properties of the ovine vagina. Primiparous and multiparous ewes had greater displacement of vaginal tissue compared to nulliparous at points Aa, Ap and Ba and lower pressure sensor measurements at points equivalent to Ap and Ba. Vaginal wall muscularis of multiparous ewes was thinner than nulliparous and had greater elastic fibre content. Collagen content was lower in primiparous than nulliparous ewes, but collagen organisation did not differ. Biomechanically, multiparous vaginal tissue was weaker and less stiff than nulliparous. Parity had a significant impact on the structure and function of the ovine vaginal wall, as the multiparous vaginal wall was weaker and had a thinner muscularis than nulliparous ewes. This correlated with “POP-Q” and pressure sensor measurements showing greater tissue laxity in multiparous compared to nulliparous ewes.
Inhibition of protein aggregation by zwitterionic polymer-based core-shell nanogels
Authors: Rajan Robin , Matsumura Kazuaki
Published: April 2017

Protein aggregation is a process by which misfolded proteins polymerizes into aggregates and forms fibrous structures with a β-sheet conformation, known as amyloids. It is an undesired outcome, as it not only causes numerous neurodegenerative diseases, but is also a major deterrent in the development of protein biopharmaceuticals. Here, we report a rational design for the synthesis of novel zwitterionic polymer-based core-shell nanogels via controlled radical polymerization. Nanogels with different sizes and functionalities in the core and shell were prepared. The nanogels exhibit remarkable efficiency in the protection of lysozyme against aggregation. Addition of nanogels suppresses the formation of toxic fibrils and also enables lysozyme to retain its enzymatic activity. Increasing the molecular weight and degree of hydrophobicity markedly increases its overall efficiency. Investigation of higher order structures revealed that lysozyme when heated without any additive loses its secondary structure and transforms into a random coil conformation. In contrast, presence of nanogels facilitates the retention of higher order structures by acting as molecular chaperones, thereby reducing molecular collisions. The present study is the first to show that it is possible to design zwitterionic nanogels using appropriate polymerization techniques that will protect proteins under conditions of extreme stress and inhibit aggregation.
XTEND: Extending the depth of field in cryo soft X-ray tomography
Authors: Otón Joaquín , Pereiro Eva , Conesa José J. , Chichón Francisco J. , Luque Daniel , Rodríguez Javier M. , Pérez-Berná Ana J. , Sorzano Carlos Oscar S. , Klukowska Joanna , Herman Gabor T. , Vargas Javier , Marabini Roberto , Carrascosa José L. , Carazo José M.
Published: April 2017

We have developed a new data collection method and processing framework in full field cryo soft X-ray tomography to computationally extend the depth of field (DOF) of a Fresnel zone plate lens. Structural features of 3D-reconstructed eukaryotic cells that are affected by DOF artifacts in standard reconstruction are now recovered. This approach, based on focal series projections, is easily applicable with closed expressions to select specific data acquisition parameters.
Pathogen recognition of a novel C-type lectin from Marsupenaeus japonicus reveals the divergent sugar-binding specificity of QAP motif
Authors: Alenton Rod Russel R. , Koiwai Keiichiro , Miyaguchi Kohei , Kondo Hidehiro , Hirono Ikuo
Published: April 2017

C-type lectins (CTLs) are calcium-dependent carbohydrate-binding proteins known to assist the innate immune system as pattern recognition receptors (PRRs). The binding specificity of CTLs lies in the motif of their carbohydrate recognition domain (CRD), the tripeptide motifs EPN and QPD bind to mannose and galactose, respectively. However, variants of these motifs were discovered including a QAP sequence reported in shrimp believed to have the same carbohydrate specificity as QPD. Here, we characterized a novel C-type lectin (MjGCTL) possessing a CRD with a QAP motif. The recombinant MjGCTL has a calcium-dependent agglutinating capability against both Gram-negative and Gram-positive bacteria, and its sugar specificity did not involve either mannose or galactose. In an encapsulation assay, agarose beads coated with rMjGCTL were immediately encapsulated from 0 h followed by melanization at 4 h post-incubation with hemocytes. These results confirm that MjGCTL functions as a classical CTL. The structure of QAP motif and carbohydrate-specificity of rMjGCTL was found to be different to both EPN and QPD, suggesting that QAP is a new motif. Furthermore, MjGCTL acts as a PRR binding to hemocytes to activate their adherent state and initiate encapsulation.
Glycation of paraoxonase 1 by high glucose instigates endoplasmic reticulum stress to induce endothelial dysfunction in vivo
Authors: Yu Wei , Liu Xiaoli , Feng Liru , Yang Hui , Yu Weiye , Feng Tiejian , Wang Shuangxi , Wang Jun , Liu Ning
Published: April 2017

High-density lipoprotein (HDL) modulates low-density lipoprotein and cell membrane oxidation through the action of paraoxonase-1 (PON1). Endoplasmic reticulum (ER) stress has been linked to a wide range of human pathologies including diabetes, obesity, and atherosclerosis. Previous studies have reported that PON1 is glycated in diabetes. The aim of this study is to investigate whether and how PON1 glycation contributes to endothelial dysfunction in diabetes. ER stress markers were monitored by western blot. Endothelial function was determined by organ bath. Incubation of recombinant PON1 proteins with high glucose increased PON1 glycation and reduced PON1 activity. Exposure of HUVECs to glycated PON1 induced prolonged ER stress and reduced SERCA activity, which were abolished by tempol, apocynin, BAPTA, and p67 and p22 siRNAs. Chronic administration of amino guanidine or 4-PBA prevented endothelial dysfunction in STZ-injected rats. Importantly, injection of glycated PON1 but not native PON1 induced aberrant ER stress and endothelial dysfunction in rats, which were attenuated by tempol, BAPTA, and 4-PBA. In conclusion, glycation of PON1 by hyperglycemia induces endothelial dysfunction through ER stress. In perspectives, PON1 glycation is a novel risk factor of hyperglycemia-induced endothelial dysfunction. Therefore, inhibition of oxidative stress, chelating intracellular Ca2+, and ER chaperone would be considered to reduce vascular complications in diabetes.
Nucleotide Dependent Switching in Rho GTPase: Conformational Heterogeneity and Competing Molecular Interactions
Authors: Kumawat Amit , Chakrabarty Suman , Kulkarni Kiran
Published: April 2017

Ras superfamily of GTPases regulate myriad cellular processes through a conserved nucleotide (GTP/GDP) dependent switching mechanism. Unlike Ras family of GTPases, for the Rho GTPases, there is no clear evidence for the existence of “sub-states” such as state 1 & state 2 in the GTP bound form. To explore the nucleotide dependent conformational space of the Switch I loop and also to look for existence of state 1 like conformations in Rho GTPases, atomistic molecular dynamics and metadynamics simulations on RhoA were performed. These studies demonstrate that both the nucleotide-free state and the GDP bound “OFF” state have very similar conformations, whereas the GTP bound “ON” state has unique conformations with signatures of two intermediate states. The conformational free energy landscape for these systems suggests the presence of multiple intermediate states. Interestingly, the energetic penalty of exposing the non-polar residues in the GTP bound form is counter balanced by the favourable hydrogen bonded interactions between the γ-phosphate group of GTP with the highly conserved Tyr34 and Thr37 residues. These competing molecular interactions lead to a tuneable energy landscape of the Switch I conformation, which can undergo significant changes based on the local environment including changes upon binding to effectors.
Lack of spontaneous age-related brain pathology in Octodon degus: a reappraisal of the model
Authors: Bourdenx Mathieu , Dovero Sandra , Thiolat Marie-Laure , Bezard Erwan , Dehay Benjamin
Published: April 2017

Neurodegenerative diseases are characterized by the degeneration of specific brain areas associated with accumulation of disease-related protein in extra- or intra-cellular deposits. Their preclinical investigations are mostly based on genetically-engineered animals. Despite their interest, these models are often based on high level of disease-related protein expression, thus questioning their relevance to human pathology and calling for the alternate use of ecological models. In the past few years, Octodon degus has emerged as a promising animal model displaying age-dependent Alzheimer’s disease-related pathology. As neurodegenerative-related proteins often co-deposit in the brain of patients, we assessed the occurrence of α-synuclein-related pathology in this model using state-of-the-art immunohistochemistry and biochemistry. Despite our efforts and in contrast with previously published results, our study argues against the use of Octodon degus as a suitable natural model of neurodegenerative disorder as we failed to identify either Parkinson’s disease- or Alzheimer’s disease-related brain pathologies.
Inhibition of epidermal growth factor receptor attenuates atherosclerosis via decreasing inflammation and oxidative stress
Authors: Wang Lintao , Huang Zhouqing , Huang Weijian , Chen Xuemei , Shan Peiren , Zhong Peng , Khan Zia , Wang Jingying , Fang Qilu , Liang Guang , Wang Yi
Published: April 2017

Atherosclerosis is a progressive disease leading to loss of vascular homeostasis and entails fibrosis, macrophage foam cell formation, and smooth muscle cell proliferation. Recent studies have reported that epidermal growth factor receptor (EGFR) is involved vascular pathophysiology and in the regulation of oxidative stress in macrophages. Although, oxidative stress and inflammation play a critical role in the development of atherosclerosis, the underlying mechanisms are complex and not completely understood. In the present study, we have elucidated the role of EGFR in high-fat diet-induced atherosclerosis in apolipoprotein E null mice. We show increased EGFR phosphorylation and activity in atherosclerotic lesion development. EGFR inhibition prevented oxidative stress, macrophage infiltration, induction of pro-inflammatory cytokines, and SMC proliferation within the lesions. We further show that EGFR is activated through toll-like receptor 4. Disruption of toll-like receptor 4 or the EGFR pathway led to reduced inflammatory activity and foam cell formation. These studies provide evidence that EGFR plays a key role on the pathogenesis of atherosclerosis, and suggests that EGFR may be a potential therapeutic target in the prevention of atherosclerosis development.
maLPA1-null mice as an endophenotype of anxious depression
Authors: Moreno-Fernández R D , Pérez-Martín M , Castilla-Ortega E , Rosell del Valle C , García-Fernández M I , Chun J , Estivill-Torrús G , Rodríguez de Fonseca F , Santín L J , Pedraza C
Published: April 2017

Anxious depression is a prevalent disease with devastating consequences and a poor prognosis. Nevertheless, the neurobiological mechanisms underlying this mood disorder remain poorly characterized. The LPA1 receptor is one of the six characterized G protein-coupled receptors (LPA1–6) through which lysophosphatidic acid acts as an intracellular signalling molecule. The loss of this receptor induces anxiety and several behavioural and neurobiological changes that have been strongly associated with depression. In this study, we sought to investigate the involvement of the LPA1 receptor in mood. We first examined hedonic and despair-like behaviours in wild-type and maLPA1 receptor null mice. Owing to the behavioural response exhibited by the maLPA1-null mice, the panic-like reaction was assessed. In addition, c-Fos expression was evaluated as a measure of the functional activity, followed by interregional correlation matrices to establish the brain map of functional activation. maLPA1-null mice exhibited anhedonia, agitation and increased stress reactivity, behaviours that are strongly associated with the psychopathological endophenotype of depression with anxiety features. Furthermore, the functional brain maps differed between the genotypes. The maLPA1-null mice showed increased limbic-system activation, similar to that observed in depressive patients. Antidepressant treatment induced behavioural improvements and functional brain normalisation. Finally, based on validity criteria, maLPA1-null mice are proposed as an animal model of anxious depression. Here, for we believe the first time, we have identified a possible relationship between the LPA1 receptor and anxious depression, shedding light on the unknown neurobiological basis of this subtype of depression and providing an opportunity to explore new therapeutic targets for the treatment of mood disorders, especially for the anxious subtype of depression.
An interaction network of mental disorder proteins in neural stem cells
Authors: Moen M J , Adams H H H , Brandsma J H , Dekkers D H W , Akinci U , Karkampouna S , Quevedo M , Kockx C E M , Ozgür Z , van IJcken W F J , Demmers J , Poot R A
Published: April 2017

Mental disorders (MDs) such as intellectual disability (ID), autism spectrum disorders (ASD) and schizophrenia have a strong genetic component. Recently, many gene mutations associated with ID, ASD or schizophrenia have been identified by high-throughput sequencing. A substantial fraction of these mutations are in genes encoding transcriptional regulators. Transcriptional regulators associated with different MDs but acting in the same gene regulatory network provide information on the molecular relation between MDs. Physical interaction between transcriptional regulators is a strong predictor for their cooperation in gene regulation. Here, we biochemically purified transcriptional regulators from neural stem cells, identified their interaction partners by mass spectrometry and assembled a protein interaction network containing 206 proteins, including 68 proteins mutated in MD patients and 52 proteins significantly lacking coding variation in humans. Our network shows molecular connections between established MD proteins and provides a discovery tool for novel MD genes. Network proteins preferentially co-localize on the genome and cooperate in disease-relevant gene regulation. Our results suggest that the observed transcriptional regulators associated with ID, ASD or schizophrenia are part of a transcriptional network in neural stem cells. We find that more severe mutations in network proteins are associated with MDs that include lower intelligence quotient (IQ), suggesting that the level of disruption of a shared transcriptional network correlates with cognitive dysfunction.
Deficit of state-dependent risk attitude modulation in gambling disorder
Authors: Fujimoto A , Tsurumi K , Kawada R , Murao T , Takeuchi H , Murai T , Takahashi H
Published: April 2017

Gambling disorder (GD) is often considered as a problem of trait-like risk preference. However, the symptoms of GD cannot be fully understood by this trait view. In the present study, we hypothesized that GD patients also had problem with a flexible control of risk attitude (state-dependent strategy optimization), and aimed to investigate the mechanisms underlying abnormal risk-taking of GD. To address this issue, we tested GD patients without comorbidity (GD group: n=21) and age-matched healthy control participants (HC group: n=29) in a multi-step gambling task, in which participants needed to clear ‘block quota’ (required units to clear a block, 1000–7000 units) in 20 choices, and conducted a task-functional magnetic resonance imaging (fMRI) experiment. Behavioral analysis indeed revealed a less flexible risk-attitude change in the GD group; the GD group failed to avoid risky choice in a specific quota range (low-quota condition), in which risky strategy was not optimal to solve the quota. Accordingly, fMRI analysis highlighted diminished functioning of the dorsolateral prefrontal cortex (dlPFC), which has been heavily implicated in cognitive flexibility. To our knowledge, the present study provided the first empirical evidence of a deficit of state-dependent strategy optimization in GD. Focusing on flexible control of risk attitude under quota may contribute to a better understanding of the psychopathology of GDs.
Determination of anionic surfactants in real samples using a low-cost and high sensitive solid contact surfactant sensor with MWCNTs as the ion-to-electron transducer
Authors: Sakač Nikola , Karnaš Maja , Jozanović Marija , Medvidović-Kosanović Martina , Martinez Sanja , Macan Jelena , Sak-Bosnar Milan
Published: April 2017

Long-life, low-cost and fast-response graphite pencil lead surfactant sensors based on MWCNTs.
Increased humidity can soften glassy Langmuir polymer films by two mechanisms: plasticization of the polymer material, and suppression of the evaporation cooling effect
Authors: Kim Hyun Chang , Choi Yun Hwa , Bu Wei , Meron Mati , Lin Binhua , Won You-Yeon
Published: April 2017

Increasing the relative humidity decreases the surface pressure of a glassy Langmuir polymer film.
Impact of lipid composition and photosensitizer hydrophobicity on the efficiency of light-triggered liposomal release
Authors: Massiot Julien , Makky Ali , Di Meo Florent , Chapron David , Trouillas Patrick , Rosilio Véronique
Published: April 2017

Photo-triggerable liposomes are considered nowadays as promising drug delivery devices due to their potential to release encapsulated drugs in a spatial and temporal manner.
Mastering the magnetic susceptibility of magnetically responsive bicelles with 3β-amino-5-cholestene and complexed lanthanide ions
Authors: Isabettini Stéphane , Liebi Marianne , Kohlbrecher Joachim , Ishikawa Takashi , Fischer Peter , Windhab Erich J. , Walde Peter , Kuster Simon
Published: April 2017

Generating lanthanide-chelating aminocholesterol-doped phospholipid bicelles with unprecedented magnetic alignment and tunable magnetic susceptibility.
Hierarchical BiOI nanostructures supported on a metal organic framework as efficient photocatalysts for degradation of organic pollutants in water
Authors: Jahurul Islam M. , Kim Hyun Kook , Amaranatha Reddy D. , Kim Yujin , Ma Rory , Baek Heehyun , Kim Joonghan , Kim Tae Kyu
Published: April 2017

This work demonstrates a novel design strategy for BiOI–MOF nanohybrids and their application for water purification.
A pH-controlled recyclable indolinooxazolidine tagged N-heterocyclic carbene Ru catalyst for olefin metathesis
Authors: Duan Yulian , Wang Tao , Xie Qingxiao , Yu Xiaobo , Guo Weijie , Wu Shutao , Li Danfeng , Wang Jianhui , Liu Guiyan
Published: April 2017

A pH-controlled recyclable indolinooxazolidine tagged N-heterocyclic carbene Ru catalyst for olefin metathesis has been developed.
CO2-Stimulated morphology transition of ABC miktoarm star terpolymer assemblies
Authors: Huo Meng , Du Haotian , Zeng Min , Pan Long , Fang Tommy , Xie Xuming , Wei Yen , Yuan Jinying
Published: April 2017

CO2-Regulated self-assembly of star terpolymers star-[poly(ethylene glycol)-polystyrene-poly[2-(N,N-diethylamino)ethyl methacrylate]] (μ-PEG-PS-PDEA) was studied and an unusual vesicle/microsphere-to-lamella transition upon CO2 stimulation was observed.
Effects of alkali-oxygen oxidation temperature on the structures and combustion properties of Shengli lignite
Authors: Wang Dandan , He Runxia , Wang Bin , Zhou Huacong , Song Yinmin , Zhi Keduan , Chen Jiaming , Li Na , Ban Yanpeng , Liu Quansheng
Published: April 2017

Spontaneous combustion has become a critical limiting factor for the safe and efficient utilization of low rank coals.
Magnetically recyclable self-assembled thin films for highly efficient water evaporation by interfacial solar heating
Authors: Chen Rong , Wu Zhejian , Zhang Tuqiao , Yu Tingchao , Ye Miaomiao
Published: April 2017

Hydrophobic magnetic microspheres can self-assemble into a thin film and float on the surface of water. The formed film was used as a photothermal material for water evaporation based on a new concept of interfacial solar heating.
High serum thrombospondin-1 concentration is associated with slower abdominal aortic aneurysm growth and deficiency of thrombospondin-1 promotes angiotensin II induced aortic aneurysm in mice
Authors: Krishna Smriti Murali , Seto Sai Wang , Jose Roby , Li Jiaze , Moxon Joseph , Clancy Paula , Crossman David J. , Norman Paul , Emeto Theophilus I. , Golledge Jonathan
Published: April 2017

Abdominal aortic aneurysm (AAA) is a common age-related vascular disease characterized by progressive weakening and dilatation of the aortic wall. Thrombospondin-1 (TSP-1; gene Thbs1) is a member of the matricellular protein family important in the control of extracellular matrix (ECM) remodelling. In the present study, the association of serum TSP-1 concentration with AAA progression was assessed in 276 men that underwent repeated ultrasound for a median 5.5 years. AAA growth was negatively correlated with serum TSP-1 concentration (Spearman’s rho −0.129, P=0.033). Men with TSP-1 in the highest quartile had a reduced likelihood of AAA growth greater than median during follow-up (OR: 0.40; 95% confidence interval (CI): 0.19–0.84, P=0.016, adjusted for other risk factors). Immunohistochemical staining for TSP-1 was reduced in AAA body tissues compared with the relatively normal AAA neck. To further assess the role of TSP-1 in AAA initiation and progression, combined TSP-1 and apolipoprotein deficient (Thbs1−/−ApoE−/−, n=20) and control mice (ApoE−/−, n=20) were infused subcutaneously with angiotensin II (AngII) for 28 days. Following AngII infusion, Thbs1−/− ApoE−/− mice had larger AAAs by ultrasound (P=0.024) and ex vivo morphometry measurement (P=0.006). The Thbs1−/−ApoE−/− mice also showed increased elastin filament degradation along with elevated systemic levels and aortic expression of matrix metalloproteinase (MMP)-9. Suprarenal aortic segments and vascular smooth muscle cells (VSMCs) isolated from Thbs1−/−ApoE−/− mice showed reduced collagen 3A1 gene expression. Furthermore, Thbs1−/−ApoE−/− mice had reduced aortic expression of low-density lipoprotein (LDL) receptor-related protein 1. Collectively, findings from the present study suggest that TSP-1 deficiency promotes maladaptive remodelling of the ECM leading to accelerated AAA progression.
Future directions for the discovery of antibiotics from actinomycete bacteria
Authors: Devine Rebecca , Hutchings Matthew I. , Holmes Neil A.
Published: April 2017

Antimicrobial resistance (AMR) is a growing societal problem, and without new anti-infective drugs, the UK government-commissioned O'Neil report has predicted that infectious disease will claim the lives of an additional 10 million people a year worldwide by 2050. Almost all the antibiotics currently in clinical use are derived from the secondary metabolites of a group of filamentous soil bacteria called actinomycetes, most notably in the genus Streptomyces. Unfortunately, the discovery of these strains and their natural products (NPs) peaked in the 1950s and was then largely abandoned, partly due to the repeated rediscovery of known strains and compounds. Attention turned instead to rational target-based drug design, but this was largely unsuccessful and few new antibiotics have made it to clinic in the last 60 years. In the early 2000s, however, genome sequencing of the first Streptomyces species reinvigorated interest in NP discovery because it revealed the presence of numerous cryptic NP biosynthetic gene clusters that are not expressed in the laboratory. Here, we describe how the use of new technologies, including improved culture-dependent and -independent techniques, combined with searching underexplored environments, promises to identify a new generation of NP antibiotics from actinomycete bacteria.
Millimetre‐wave air‐filled substrate integrated waveguide slot array antenna
Authors: Parment F. , Ghiotto A. , Vuong T.‐P. , Duchamp J.‐M. , Wu K.
Published: April 2017

An air‐filled substrate integrated waveguide (AFSIW) slot array antenna based on multilayer PCB process is proposed. For comparison and demonstration purposes, 1 × 4 slot array antennas based on both AFSIW and conventional dielectric‐filled SIW (DFSIW) operating at 30.5 GHz are designed, fabricated and measured. The exampled AFSIW 1 × 4 slot array antenna achieves 44 and 18% narrower measured H‐plane and E‐plane half‐power beamwidth, respectively, and simulated radiation efficiency improved by 1.6%, resulting in an overall measured gain improvement of 3.5 dB compared with its DFSIW counterpart. This antenna is of high interest for the design of efficient arrays based on high‐performance AFSIW feeding network.
Miniaturised bandstop frequency selective surface based on quasi‐lumped inductor and capacitor
Authors: Zhao Pengchao , Zong Zhiyuan , Li Bo , Wu Wen , Fang Dagang
Published: April 2017

A novel frequency selective surface (FSS) based on quasi‐lumped inductor and capacitor is proposed to miniaturise FSS unit cell size. The quasi‐lumped inductor and capacitor, implemented by meander line and parallel‐plate capacitor, respectively, are connected in series to achieve a bandstop filtering response. This FSS provides the advantages of small unit cell size, independent control of the filtering response for different polarisations, and easy optimal design of desired resonant frequency and bandwidth. To validate the proposed design concept, a bandstop FSS operating at 2.42 GHz was designed, fabricated, and measured. Its unit cell size is only (λ0/28) × (λ0/28), where λ0 refers to the resonant wavelength in free space. Both the simulated and measured results exhibit stable filtering performance under different polarisations and incident angles (up to 60°).
Predicted and measured temperature compensated surface acoustic wave devices for high‐temperature applications
Authors: Ayes A. , Maskay A. , Pereira da Cunha M.
Published: April 2017

Industrial monitoring and process control, power plants, aerospace industry, military equipment manufacturing, oil and gas industries are examples of businesses in need for high‐temperature and harsh‐environment electronic components and systems. In particular, resonators and filters that operate beyond the 125°C military range upper limit, normally dictated by silicon‐based semiconductor devices, are required in applications which demand frequency control, clocking and sensors. In this Letter, temperature compensated surface acoustic wave orientations appropriate for the fabrication of resonators and filters >125°C have been identified through numerical calculations and experimentally confirmed on a commercially available langasite wafer, a piezoelectric crystal which operates at high temperatures. Resonator filters have been designed, fabricated and tested along two orientations, confirming the zero temperature sensitivities at 150 and 300°C. These devices are of great interest for modern harsh environment frequency control, timing and sensor applications.
Two cellular resource‐based models linking growth and parts characteristics aids the study and optimisation of synthetic gene circuits
Authors: Wang Huijuan , Ling Maurice H.T. , Chua Tze Kwang , Poh Chueh Loo
Published: April 2017

A major challenge in synthetic genetic circuit development is the inter‐dependency between heterologous gene expressions by circuits and host's growth rate. Increasing heterologous gene expression increases burden to the host, resulting in host growth reduction; which reduces overall heterologous protein abundance. Hence, it is difficult to design predictable genetic circuits. Here, we develop two biophysical models; one for promoter, another for RBS; to correlate heterologous gene expression and growth reduction. We model cellular resource allocation in E. coli to describe the burden, as growth reduction, caused by genetic circuits. To facilitate their uses in genetic circuit design, inputs to the model are common characteristics of biological parts [e.g. relative promoter strength (RPU) and relative ribosome binding sites strength (RRU)]. The models suggest that E. coli's growth rate reduces linearly with increasing RPU/RRU of the genetic circuits; thus, providing 2 handy models taking parts characteristics as input to estimate growth rate reduction for fine tuning genetic circuit design in silico prior to construction. Our promoter model correlates well with experiments using various genetic circuits, both single and double expression cassettes, up to a relative promoter unit of 3.7 with a 60% growth rate reduction (average R2∼0.9).
Design of non‐singular adaptive terminal backstepping controllers with perturbation estimation for non‐linear systems in semi‐strict feedback form
Authors: Cheng Chih‐Chiang , Chiang Yu‐Chi
Published: April 2017

An adaptive non‐singular backstepping control with perturbation estimation scheme is designed for a class of multi‐input systems with matched and mismatched perturbations to solve the regulation problems. The design procedure of this control scheme mainly contains two parts. The first part is the design of the virtual control inputs, the second part is the design of control input functions and perturbation estimation mechanism. The main advantage of the proposed control scheme is that, without knowing the upper bounds of perturbations, the controlled system is still capable of suppressing the perturbations so that the controlled states are able to reach zero within a finite time. Another advantage is that there is no singular problem at all. Finally, a numerical example and a practical application are given for demonstrating the feasibility of the proposed control strategy.
Controllability and observability of CPSs under networked adversarial attacks
Authors: Li Yining , Wu Jing , Li Shaoyuan
Published: April 2017

To characterise the resilience of a control system in cyber‐physical systems (CPSs) against actuator attacks and sensor attacks, we introduce new notions of controllability and observability to derive conditions under whether the state can be stabled and reconstructed by the existing control signal and measurements over a period of time. With the understanding that some of the available system's inputs and outputs may have been compromised by the adversary, we derive the necessary and sufficient conditions to utilise standard controllability and observability matrix tests to be calculated in checking whether a CPS is ‘controllable and observable under attacks’, and verify the theorems by a simulation of 9‐bus power grid system under attacks.
Delay‐dependent stability and stabilisation of two‐dimensional positive Markov jump systems with delays
Authors: Van Hien Le , Trinh Hieu
Published: April 2017

This study considers the problem of exponential mean stability and stabilisation of two‐dimensional positive Markov jump systems with delays. Necessary and sufficient delay‐dependent conditions for exponential mean stability of the closed‐loop system are first derived. Then, a design scheme based on a linear programming problem is proposed for obtaining parameters of a mode‐dependent controller that makes the closed‐loop system positive and exponentially mean stable. Finally, two numerical examples are presented to illustrate the effectiveness of the obtained results.
Hardware architecture and optimisation of FPP particle PHD filter for multi‐target tracking in cyber‐physical systems
Authors: Li Chao , Shi Zhiguo , Chen Jiming
Published: April 2017

To meet the rapidly growing demand of localisation and tracking information of mobile agents in cyber‐physical systems, in this paper, we propose a fully pipelined and parallel (FPP) hardware architecture of particle probability hypothesis density (PHD) filter for multi‐target tracking on the multi‐cores processor hardware platforms, where an improved resampling algorithm is designed. We formulate the demand of minimising the processing delay in this architecture as an optimisation problem, which can be efficiently solved by transforming it to a group of mixed non‐linear integer programming problems. Delay analysis shows that the proposed FPP particle PHD filter achieves significant improvement of real‐time performance, and simulation results demonstrate that tracking performance remains at the same level as traditional particle PHD filters.
RMPC‐based security problem for polytopic uncertain system subject to deception attacks and persistent disturbances
Authors: Liu Shuai , Song Yan , Wei Guoliang , Huang Xuegang
Published: April 2017

This study investigates the security problem for a class of polytopic uncertain systems by virtue of robust model predictive control (RMPC) approach. In consideration of the difficulties in accessing the system states, a novel dynamic‐output‐feedback RMPC strategy is presented to guarantee the security of the discussed system subject to randomly occurring deception attacks and persistent bounded disturbances. Such the randomly occurring attack is characterised by using a Bernoulli binary distributed white sequence with a given successful probability. Under this condition, a novel concept of system security in mean‐square sense is presented based on RMPC technique, in which the system is required not only to satisfy the specified performance index but also to keep all the states in an invariant set by designing a time‐varying terminal constraint set. Moreover, due to the presence of the persistent bounded disturbances and model uncertainties, the worst‐case cost function is considered. By using a Lyapunov function approach dependent of the input‐to‐state stability (ISS), the dynamic‐output‐feedback RMPC scheme is designed by solving an optimisation problem including some inequality constraints, and the upper bound of the investigated cost function is obtained. In addition, the ISS performance is ensured for the polytopic uncertain system with both the randomly occurring deception attacks and persistent disturbances. Finally, a numerical simulation example is developed to show the effectiveness of the proposed dynamic‐output‐feedback RMPC strategy.
Robust output regulation of uncertain linear fractional transformation systems with application to non‐linear Chua's circuit
Authors: Yuan Chengzhi
Published: April 2017

This study deals with the robust output regulation problem for a class of uncertain systems in a linear fractional transformation form. The problem is addressed under a measurement output‐feedback framework, i.e. no full information of both plant and exosystem states is assumed for feedback control use. A new robust control law with a novel output regulator structure is proposed, based on which sufficient conditions for robust output regulability and stability are established in terms of linear matrix equations plus a set of linear matrix inequalities. As a result, the optimal output regulation control solution can be synthesised effectively via convex optimisation. Finally, the proposed robust output regulation design scheme will be applied to solve the chaos tracking control problem for the non‐linear Chua's circuit.
Estimation of edge displacement against brightness and camera‐to‐object distance
Authors: Seo Suyoung
Published: April 2017

This study proposes a systematic method to estimate edge displacement (ED) from ground truth edges. To obtain ground truth edges and test edges, a series of target sheets containing the reference regions and brightness contrast regions were designed. Further, the brightness contrast regions were designed to contain foreground and background brightness between which the image edges occur. By varying the foreground brightness (FB), the influence of the FB on the edge locations was tested. Moreover, the influence of camera‐to‐object distance on the edge locations was tested. A simple least‐squares method using slope profiles and a slope‐based weighting scheme is proposed for calculating the edges occurring in contrast regions with subpixel accuracy. The experiment results revealed that a bright foreground moves the edge location towards the dark side of the edges in the range of 0–0.6 pixels with strong relationships between the FB and magnitude of ED.
Deep‐learning architecture to forecast destinations of bus passengers from entry‐only smart‐card data
Authors: Jung Jaeyoung , Sohn Keemin
Published: April 2017

Although smart‐card data secures collective travel information on public transportation users, the reality is that only a few cities are equipped with an automatic fare collection (AFC) system that can provide user information for both boarding and alighting locations. Many researchers have delved into forecasting the destinations of smart‐card users. Such effort, however, have never been validated with actual data on a large scale. In the present study, a deep‐learning model was developed to estimate the destinations of bus passengers based on both entry‐only smart‐card data and land‐use characteristics. A supervised machine‐learning model was trained using exact information on both boarding and alighting. That information was provided by the AFC system in Seoul, Korea. The model performance was superior to that of the most prevalent schemes developed thus far.
Multiphase optimal injection PWM with dual carrier frequency to reduce current THD
Authors: Chen Keng‐Yuan , Xie Yu‐Lin
Published: April 2017

Multiphase voltage source inverter drives have recently applied to various industrial applications for variable speed motor drives. Both space‐vector pulse‐width modulation (SVPWM) and discontinuous PWM (DPWM) are commonly used modulators. Under the three‐phase setting, it is well known that SVPWM is preferred for small modulation indices, whereas DPWM is better for large modulation indices. However, little detailed discussions on multiphase setting are reported. Further, for phase number higher than 5, no explicit instructions on how to select between SVPWM and DPWM to reduce current total harmonics distortion (THD). This study developed a generalised method to select either SVPWM or DPWM under different reference amplitudes and angles. The method can be easily extended to general N‐phase settings. Firstly, a generalised expression of PWM harmonic flux which is proportional to current distortion is derived. Second, by selecting the modulator that corresponds to minimum rms harmonic flux for every carrier period, optimal injection pulse‐width modulation (OIPWM) is constructed. The theoretical analyses indicate that the harmonics distortion of OIPWM is greatly improved comparing with conventional SVPWM. A five‐phase inverter drive built for experiments verifies the correctness and effectiveness of the proposed OIPWM.
Optimised inverter by switch sharing: a control solution for photovoltaic applications
Authors: Jamaludin Jafferi , Syamsuddin Syarkawi , Rahim Nasrudin Abd , Ping Hew Wooi
Published: April 2017

Switch‐sharing‐based multilevel inverter can be useful to develop an improved‐performance DC–AC converter for low‐power photovoltaic applications. However, this cannot be fully achieved without having a reliable control solution. Hence, this study presents a smart control strategy equipped with an adaptive proportional–integral controller. The adaptive characteristic is established through a tuning module that continuously fine tunes only one parameter. With the tuning mechanism, the load current quality is able to be continuously retained at the acceptable level even during the presence of disturbances. To validate the control performance, experimental work has been conducted on a laboratory prototype under load‐disturbance conditions.
Receiver platform motion compensation in passive radar
Authors: Palmer James , Ummenhofer Martin , Summers Ashley , Bournaka Georgia , Palumbo Simon , Cristallini Diego
Published: April 2017

This study investigates the causes and effects of signal mismatch on the performance of a passive bistatic radar that employs reference signal reconstruction processing on a moving receiver platform. In addition to the transmitter's imperfections, namely carrier frequency offset and sampling clock drift, motion induced Doppler is taken into consideration and compensated. Signal processing approaches are used that exploit the unique characteristics of the terrestrial digital video broadcast waveform in order to compensate for the combined effects of transmitter mismatch and the motion induced Doppler. The proposed methods are tested on real‐field measurements acquired in Germany and Australia for single frequency network and multiple frequency network, respectively. The results demonstrate superior performance in terms of delay–Doppler discrimination.
Isolation, characterisation and enzymatic activity of Streptomyces sp. and its pH control during fermentation process
Authors: Baskaran Balraj , Muthukumarasamy Arulmozhi
Published: April 2017

Streptomyces sp. with grey white mycelium was isolated from Kodiyakkarai marine segment of east coastal of India. The isolate produced spiny spores and did not produce any diffusible pigments. Various biochemical tests were carried out to confirm the isolate classification. The amylolytic enzyme activity was estimated using the isolated strain which was confirmed by golden yellowish zone formation after using the Gram's iodine stain. The amount of amylase produced by the isolate was 6.15 U/ml. Higher living cells always produce better enzymes, so that the process parameters especially pH was maintained in fermentation chamber for higher growth and also for large‐scale growth. For maintaining the pH a mathematical process model was developed using the data obtained during the process. The addition of Kalman's filter along with proportional–integral–derivative controller gave better stability in pH. By maintaining of pH 7, growth rate was significantly increased from 0.51to 0.59 gm/l on day 5 which are discussed in the results and discussions.