bluuebunny/crossref_metadata_2025 huggingface dataset:
Antiviral effect of vitamin A on norovirus infection via modulation of the gut microbiome
Authors: Lee Heetae , Ko GwangPyo
Published: May 2016

The effect and underlying mechanism of vitamin A on norovirus infection are largely unknown. This study aimed to investigate how vitamin A administration affects the gut microbiome after norovirus infection. Here, we demonstrate that treatment with either retinol or retinoic acid (RA) inhibits murine norovirus (MNV) replication using both in vitro and in vivo models. Compositional changes in the gut microbiome associated with RA administration and/or norovirus infection were also investigated. Oral administration of RA and/or MNV significantly altered intestinal microbiome profiles. Particularly, bacterial species belonging to the Lactobacillaceae families were remarkably increased by MNV inoculation and RA administration, suggesting that the antiviral effects of RA occur via the modulation of specific microbiota. The antiviral causal effect of Lactobacillus was identified and demonstrated using in vitro models in RAW264.7 cells. The antiviral immune response to MNV was mediated by IFN-β upregulation. This study represents the first comprehensive profiling of gut microbiota in response to RA treatment against norovirus infection. Moreover, we conclude that the abundance of Lactobacillus through gut microbiota modulation by RA is at least partially responsible for norovirus inhibition.
Pixel-level plasmonic microcavity infrared photodetector
Authors: Jing You Liang , Li Zhi Feng , Li Qian , Chen Xiao Shuang , Chen Ping Ping , Wang Han , Li Meng Yao , Li Ning , Lu Wei
Published: May 2016

Recently, plasmonics has been central to the manipulation of photons on the subwavelength scale, and superior infrared imagers have opened novel applications in many fields. Here, we demonstrate the first pixel-level plasmonic microcavity infrared photodetector with a single quantum well integrated between metal patches and a reflection layer. Greater than one order of magnitude enhancement of the peak responsivity has been observed. The significant improvement originates from the highly confined optical mode in the cavity, leading to a strong coupling between photons and the quantum well, resulting in the enhanced photo-electric conversion process. Such strong coupling from the localized surface plasmon mode inside the cavity is independent of incident angles, offering a unique solution to high-performance focal plane array devices. This demonstration paves the way for important infrared optoelectronic devices for sensing and imaging.
Imaging of bacterial multicellular behaviour in biofilms in liquid by atmospheric scanning electron microscopy
Authors: Sugimoto Shinya , Okuda Ken-ichi , Miyakawa Reina , Sato Mari , Arita-Morioka Ken-ichi , Chiba Akio , Yamanaka Kunitoshi , Ogura Teru , Mizunoe Yoshimitsu , Sato Chikara
Published: May 2016

Biofilms are complex communities of microbes that attach to biotic or abiotic surfaces causing chronic infectious diseases. Within a biofilm, microbes are embedded in a self-produced soft extracellular matrix (ECM), which protects them from the host immune system and antibiotics. The nanoscale visualisation of delicate biofilms in liquid is challenging. Here, we develop atmospheric scanning electron microscopy (ASEM) to visualise Gram-positive and -negative bacterial biofilms immersed in aqueous solution. Biofilms cultured on electron-transparent film were directly imaged from below using the inverted SEM, allowing the formation of the region near the substrate to be studied at high resolution. We visualised intercellular nanostructures and the exocytosis of membrane vesicles, and linked the latter to the trafficking of cargos, including cytoplasmic proteins and the toxins hemolysin and coagulase. A thick dendritic nanotube network was observed between microbes, suggesting multicellular communication in biofilms. A universal immuno-labelling system was developed for biofilms and tested on various examples, including S. aureus biofilms. In the ECM, fine DNA and protein networks were visualised and the precise distribution of protein complexes was determined (e.g., straight curli, flagella, and excreted cytoplasmic molecular chaperones). Our observations provide structural insights into bacteria-substratum interactions, biofilm development and the internal microbe community.
Speech motor learning changes the neural response to both auditory and somatosensory signals
Authors: Ito Takayuki , Coppola Joshua H. , Ostry David J.
Published: May 2016

In the present paper, we present evidence for the idea that speech motor learning is accompanied by changes to the neural coding of both auditory and somatosensory stimuli. Participants in our experiments undergo adaptation to altered auditory feedback, an experimental model of speech motor learning which like visuo-motor adaptation in limb movement, requires that participants change their speech movements and associated somatosensory inputs to correct for systematic real-time changes to auditory feedback. We measure the sensory effects of adaptation by examining changes to auditory and somatosensory event-related responses. We find that adaptation results in progressive changes to speech acoustical outputs that serve to correct for the perturbation. We also observe changes in both auditory and somatosensory event-related responses that are correlated with the magnitude of adaptation. These results indicate that sensory change occurs in conjunction with the processes involved in speech motor adaptation.
HIV Infection Rates and Risk Behavior among Young Men undergoing community-based Testing in San Diego
Authors: Hoenigl Martin , Chaillon Antoine , Morris Sheldon R. , Little Susan J.
Published: May 2016

Approximately 80% of new HIV infections in the United States occur in men. Four out of five men diagnosed with HIV infection are men who have sex with men (MSM), with an increasing proportion of young MSM (i.e. ≤24 years of age). We performed a retrospective analysis 11,873 cisgender men participating in a community based HIV screening program in San Diego between 2008 and 2014 to characterize the HIV prevalence and sexual risk behaviors among young men. In young heterosexual men HIV prevalence was lower compared to heterosexual men between 25 and 49 years of age (0.3% vs. 1.4%, p = 0.043). Among young MSM, HIV prevalence was 5.5%, per test positivity rate 3.6%, and HIV incidence 3.4 per 100 person years (95% CI 2.2–5.4). Per test positivity rate (p = 0.008) and incidence (p < 0.001) were significantly higher among young MSM than among MSM above 24-years of age. Young MSM diagnosed with HIV infection reported significantly more serodiscordant condomless anal intercourse, bacterial sexually transmitted infections, and higher rates of methamphetamine and gamma hydroxybutyrate use when compared to young MSM who tested negative. In conclusion, young MSM are particularly vulnerable to HIV infection and may represent ideal candidates for targeted prevention interventions that increase testing uptake and/or decrease the risk of acquiring HIV infection.
The developmental effects of pentachlorophenol on zebrafish embryos during segmentation: A systematic view
Authors: Xu Ting , Zhao Jing , Xu Zhifa , Pan Ruijie , Yin Daqiang
Published: May 2016

Pentachlorophenol (PCP) is a typical toxicant and prevailing pollutant whose toxicity has been broadly investigated. However, previous studies did not specifically investigate the underlying mechanisms of its developmental toxicity. Here, we chose zebrafish embryos as the model, exposed them to 2 different concentrations of PCP, and sequenced their entire transcriptomes at 10 and 24 hours post-fertilization (hpf). The sequencing analysis revealed that high concentrations of PCP elicited systematic responses at both time points. By combining the enrichment terms with single genes, the results were further analyzed using three categories: metabolism, transporters, and organogenesis. Hyperactive glycolysis was the most outstanding feature of the transcriptome at 10 hpf. The entire system seemed to be hypoxic, although hypoxia-inducible factor-1α (HIF1α) may have been suppressed by the upregulation of prolyl hydroxylase domain enzymes (PHDs). At 24 hpf, PCP primarily affected somitogenesis and lens formation probably resulting from the disruption of embryonic body plan at earlier stages. The proposed underlying toxicological mechanism of PCP was based on the crosstalk between each clue. Our study attempted to describe the developmental toxicity of environmental pollutants from a systematic view. Meanwhile, some features of gene expression profiling could serve as markers of human health or ecological risk.
Raising the avermectins production in Streptomyces avermitilis by utilizing nanosecond pulsed electric fields (nsPEFs)
Authors: Guo Jinsong , Ma Ruonan , Su Bo , Li Yinglong , Zhang Jue , Fang Jing
Published: May 2016

Avermectins, a group of anthelmintic and insecticidal agents produced from Streptomyces avermitilis, are widely used in agricultural, veterinary and medical fields. This study presents the first report on the potential of using nanosecond pulsed electric fields (nsPEFs) to improve avermectin production in S. avermitilis. The results of colony forming units showed that 20 pulses of nsPEFs at 10 kV/cm and 20 kV/cm had a significant effect on proliferation, while 100 pulses of nsPEFs at 30 kV/cm exhibited an obvious effect on inhibition of agents. Ultraviolet spectrophotometry assay revealed that 20 pulses of nsPEFs at 15 kV/cm increased avermectin production by 42% and reduced the time for reaching a plateau in fermentation process from 7 days to 5 days. In addition, the decreased oxidation reduction potential (ORP) and increased temperature of nsPEFs-treated liquid were evidenced to be closely associated with the improved cell growth and fermentation efficiency of avermectins in S. avermitilis. More importantly, the real-time RT-PCR analysis showed that nsPEFs could remarkably enhance the expression of aveR and malE in S. avermitilis during fermentation, which are positive regulator for avermectin biosynthesis. Therefore, the nsPEFs technology presents an alternative strategy to be developed to increase avermectin output in fermentation industry.
Tissue Plasminogen Activator Neurotoxicity is Neutralized by Recombinant ADAMTS 13
Authors: Fan Mengchen , Xu Haochen , Wang Lixiang , Luo Haiyu , Zhu Ximin , Cai Ping , Wei Lixiang , Lu Lu , Cao Yongliang , Ye Rong , Fan Wenying , Zhao Bing-Qiao
Published: May 2016

Tissue plasminogen activator (tPA) is an effective treatment for ischemic stroke, but its neurotoxicity is a significant problem. Here we tested the hypothesis that recombinant ADAMTS 13 (rADAMTS 13) would reduce tPA neurotoxicity in a mouse model of stroke. We show that treatment with rADAMTS 13 in combination with tPA significantly reduced infarct volume compared with mice treated with tPA alone 48 hours after stroke. The combination treatment significantly improved neurological deficits compared with mice treated with tPA or vehicle alone. These neuroprotective effects were associated with significant reductions in fibrin deposits in ischemic vessels and less severe cell death in ischemic brain. The effect of rADAMTS13 on tPA neurotoxicity was mimicked by the N-methyl-D-aspartate (NMDA) receptor antagonist M-801 and was abolished by injection of NMDA. Moreover, rADAMTS 13 prevents the neurotoxicity effect of tPA, by blocking its interaction with the NMDA receptor NR2B and the attendant phosphorylation of NR2B and activation of ERK1/2. Finally, the NR2B-specific NMDA receptor antagonist ifenprodil abolished tPA neurotoxicity and rADAMTS 13 treatment had no further beneficial effect. Our data suggest that the combination of rADAMTS 13 and tPA may provide a novel treatment of ischemic stroke by diminishing the neurotoxic effects of exogenous tPA.
Impaired Nitric Oxide Mediated Vasodilation In The Peripheral Circulation In The R6/2 Mouse Model Of Huntington’s Disease
Authors: Kane Andrew D. , Niu Youguo , Herrera Emilio A. , Morton A. Jennifer , Giussani Dino A.
Published: May 2016

Recent evidence shows that the Huntington’s disease (HD) extends beyond the nervous system to other sites, including the cardiovascular system. Further, the cardiovascular pathology pre-dates neurological decline, however the mechanisms involved remain unclear. We investigated in the R6/2 mouse model of HD nitric oxide (NO) dependent and independent endothelial mechanisms. Femoral artery reactivity was determined by wire myography in wild type (WT) and R6/2 mice at 12 and 16 weeks of adulthood. WT mice showed increased endothelial relaxation between 12 and 16 weeks (Rmax: 72 ± 7% vs. 97 ± 13%, P < 0.05). In contrast, R6/2 mice showed enhanced endothelial relaxation already by 12 weeks (Rmax at 12w: 72 ± 7% vs. 94 ± 5%, WT vs. R6/2, P < 0.05) that declined by 16 weeks compared with WT mice (Rmax at 16w: 97 ± 13% vs. 68 ± 7%, WT vs. R6/2, P < 0.05). In WT mice, the increase in femoral relaxation between 12 and 16 weeks was due to enhanced NO dependent mechanisms. By 16 weeks of adult age, the R6/2 mouse developed overt endothelial dysfunction due to an inability to increase NO dependent vasodilation. The data add to the growing literature of non-neural manifestations of HD and implicate NO depletion as a key mechanism underlying the HD pathophysiology in the peripheral vasculature.
High resolution study of the spatial distributions of abyssal fishes by autonomous underwater vehicle
Authors: Milligan R. J. , Morris K. J. , Bett B. J. , Durden J. M. , Jones D. O. B. , Robert K. , Ruhl H. A. , Bailey D. M.
Published: May 2016

On abyssal plains, demersal fish are believed to play an important role in transferring energy across the seafloor and between the pelagic and benthic realms. However, little is known about their spatial distributions, making it difficult to quantify their ecological significance. To address this, we employed an autonomous underwater vehicle to conduct an exceptionally large photographic survey of fish distributions on the Porcupine Abyssal Plain (NE Atlantic, 4850 m water depth) encompassing two spatial scales (1–10 km2) on and adjacent to a small abyssal hill (240 m elevation). The spatial distributions of the total fish fauna and that of the two dominant morphotypes (Coryphaenoides sp. 1 and C. profundicolus) appeared to be random, a result contrary to common expectation but consistent with previous predictions for these fishes. We estimated total fish density on the abyssal plain to be 723 individuals km−2 (95% CI: 601–844). This estimate is higher and likely more precise, than prior estimates from trawl catch and baited camera techniques (152 and 188 individuals km−2 respectively). We detected no significant difference in fish density between abyssal hill and plain, nor did we detect any evidence for the existence of fish aggregations at any spatial scale assessed.
AFM force indentation analysis on leukemia cells
Authors: Fortier Hélène , Variola Fabio , Wang Chen , Zou Shan
Published: May 2016

To complement the existing literature, an automated batch analysis protocol was developed to perform unbiased data processes on AFM indentation data measured over leukemia cancer cells.
Cooperative organocatalysis of Mukaiyama-type aldol reactions by thioureas and nitro compounds
Authors: Bukhryakov Konstantin V. , Desyatkin Victor G. , Rodionov Valentin O.
Published: May 2016

A unique organocatalytic system for Mukaiyama-type aldol reactions based on the cooperative action of nitro compounds and thioureas has been identified.
A reversible B–A transition of DNA duplexes induced by synthetic cationic copolymers
Authors: Yamaguchi Nonoka , Zouzumi Yu-ki , Shimada Naohiko , Nakano Shu-ichi , Sugimoto Naoki , Maruyama Atsushi , Miyoshi Daisuke
Published: May 2016

Reversible B–A transitions of DNA duplexes were induced by synthetic cationic and anionic polymers.
Vacancy-induced manganese vanadates and their potential application to Li-ion batteries
Authors: Dufficy Martin K. , Luo Lan , Fedkiw Peter S. , Maggard Paul A.
Published: May 2016

We report on the synthesis and characterization of a novel manganese vanadate, Mn1.5(H2O)(NH4)V4O12, with rare in situ disorder of Mn(H2O)22+/2NH4+.
A DNAzyme-mediated logic gate for programming molecular capture and release on DNA origami
Authors: Li Feiran , Chen Haorong , Pan Jing , Cha Tae-Gon , Medintz Igor L. , Choi Jong Hyun
Published: May 2016

Here we design a DNA origami-based site-specific molecular capture and release platform operated by a DNAzyme-mediated logic gate process.
Arenediazonium salts as electrophiles for the oxidative addition of gold(i)
Authors: Asomoza-Solís Eric Omar , Rojas-Ocampo Jonathan , Toscano Rubén Alfredo , Porcel Susana
Published: May 2016

Arenediazonium salts have been found to behave as efficient electrophiles for the oxidation of gold(i). Starting from anilines, a one pot cross-coupling reaction of anilines with silver acetylides mediated by gold has been developed.
BNg3F3: the first three noble gas atoms inserted into mono-centric neutral compounds – a theoretical study
Authors: Chen Wei , Chen Guang-Hui , Wu Di , Wang Qiang
Published: May 2016

Following the study of HXeOXeH and HXeCCXeH, in which two Xe atoms were inserted into H2O and C2H2 theoretically and experimentally, the structures and stability of BNg3F3 (Ng = Ar, Kr and Xe), in which three Ng atoms are inserted into BF3, have been explored theoretically using DFT and ab initio calculations.
Interlayer coupling in two-dimensional titanium carbide MXenes
Authors: Hu Tao , Hu Minmin , Li Zhaojin , Zhang Hui , Zhang Chao , Wang Jingyang , Wang Xiaohui
Published: May 2016

The interlayer coupling in Tin+1CnT2(n= 1 and 2, T = OH, O and F) is significantly stronger than van der Waals bonding, as evidenced by the fact that binding energies are 2–6 times those of graphite and MoS2from first-principles calculations.
Ternary borides Nb7Fe3B8 and Ta7Fe3B8 with Kagome-type iron framework
Authors: Zheng Qiang , Gumeniuk Roman , Borrmann Horst , Schnelle Walter , Tsirlin Alexander A. , Rosner Helge , Burkhardt Ulrich , Reissner Michael , Grin Yuri , Leithe-Jasper Andreas
Published: May 2016

Nb7Fe3B8 and Ta7Fe3B8 feature Fe atoms occupying a planar Kagome-type framework.
Water in asymmetric organocatalytic systems: a global perspective
Authors: Jimeno Ciril
Published: May 2016

This review offers a classification with illustrative examples of the uses and effects of water in asymmetric organocatalysis.
Synthesis of tumor necrosis factor α for use as a mirror-image phage display target
Authors: Petersen Mark E. , Jacobsen Michael T. , Kay Michael S.
Published: May 2016

Chemical synthesis of TNFα, a central regulator of inflammation, for use as a mirror-image phage display target.
Properties and applications of designable and photo/redox dual responsive surfactants with the new head group 2-arylazo-imidazolium
Authors: Lin Changxu , Yang Long , Xu Mengchun , An Qi , Xiang Zheng , Liu Xiangyang
Published: May 2016

2-Arylazo-imidazolium grafted imidazolium surfactants with structural extensibility and reversible responsiveness to photo and electrochemical stimuli for further usage in a sol–gel process.
Molecular dynamics study on the aggregation behaviour of different positional isomers of sodium dodecyl benzenesulphonate
Authors: Wei Yaoyao , Liu Guokui , Wang Zhongni , Yuan Shiling
Published: May 2016

Schematic diagram of anionic structures (1Φ12 and 6Φ12).
The effect of small pyramid texturing on the enhanced passivation and efficiency of single c-Si solar cells
Authors: Ju Minkyu , Balaji Nagarajan , Park Cheolmin , Thanh Nguyen Huong Thi , Cui Jian , Oh Donghyun , Jeon Minhan , Kang Jiyoon , Shim Gyeongbae , Yi Junsin
Published: May 2016

In this work, small random pyramid texturing (0.5–2 μm size) was generated with chemical nano-masking, to enhance the surface passivation of commercial p-type Cz-Si wafers.
Synthesis of a dihydroquinoline based fluorescent cyanine for selective, naked eye, and turn off detection of Fe3+ions
Authors: Vijay K. , Nandi C. , Samant Shriniwas D.
Published: May 2016

A cyanine dye was synthesized by condensing 6-formylated 1,2,2,4-tetramethyl-1,2-dihydroquinoline (TMDQ) and 1,7-dimethyl-2-phenylimidazo[1,2-a]pyridin-1-ium iodide.
Size-tunable hydrophilic cerium oxide nanoparticles as a ‘turn-on’ fluorescence sensor for the rapid detection of ultralow concentrations of vitamin C
Authors: Krishnan Asha , Sreeremya Thadathil S. , Ghosh Swapankumar
Published: May 2016

Hydrophilic ceria nanoparticles fabricated via a bilayer surface functionalization approach with tunable redox and optical properties with Ce3+ content has been utilised as a sensor to estimate vitamin C with high reproducibility, selectivity and rapidity.
Novel access to carbonyl and acetylated compounds: the role of the tetra-n-butylammonium bromide/sodium nitrite catalyst
Authors: Sheykhan Mehdi , Moafi Hadi Fallah , Abbasnia Masoumeh
Published: May 2016

A novel aerobic oxidation of alcohols without the use of any oxidants was developed.
MIA-plot: a graphical tool for viewing descriptor contributions in MIA-QSAR
Authors: Barigye Stephen J. , Duarte Mariene H. , Nunes Cleiton A. , Freitas Matheus P.
Published: May 2016

Chemically intuitive information from MIA molecular descriptors that correlate to bioactivity values was obtained from the analysis of PLS regression coefficients and variable importance in projection scores.
Structure and assembly mechanisms of toxic human islet amyloid polypeptide oligomers associated with copper
Authors: Lee Shin Jung C. , Choi Tae Su , Lee Jong Wha , Lee Hyuck Jin , Mun Dong-Gi , Akashi Satoko , Lee Sang-Won , Lim Mi Hee , Kim Hugh I.
Published: May 2016

The molecular interaction of hIAPP with Cu(ii) mediates the formation of off-pathway and toxic oligomers which have small-sized and random coil structures.
Direct observation of reversible oxygen anion redox reaction in Li-rich manganese oxide, Li2MnO3, studied by soft X-ray absorption spectroscopy
Authors: Oishi Masatsugu , Yamanaka Keisuke , Watanabe Iwao , Shimoda Keiji , Matsunaga Toshiyuki , Arai Hajime , Ukyo Yoshio , Uchimoto Yoshiharu , Ogumi Zempachi , Ohta Toshiaki
Published: May 2016

We investigated the reversible charge compensation mechanism of an Li2MnO3 electrode using soft XAS analysis. We concluded that both the Mn and O ions participated in the charge compensation reactions during the reversible redox cycles.
Efficient ceria nanostructures for enhanced solar fuel production via high-temperature thermochemical redox cycles
Authors: Gao Xiang , Vidal Alejandro , Bayon Alicia , Bader Roman , Hinkley Jim , Lipiński Wojciech , Tricoli Antonio
Published: May 2016

The flame-made nanostructured agglomerates achieved ca. 200% higher syngas production rates and the highest redox capacity so far reported for ceria.
A nanostructured ceramic fuel electrode for efficient CO2/H2O electrolysis without safe gas
Authors: Li Yihang , Li Pan , Hu Bobing , Xia Changrong
Published: May 2016

There is increasing interest in converting CO2/H2O to syngas via solid oxide electrolysis cells (SOECs) driven by renewable and nuclear energies.
Facile synthesis of 3D hierarchical N-doped graphene nanosheet/cobalt encapsulated carbon nanotubes for high energy density asymmetric supercapacitors
Authors: Balamurugan Jayaraman , Thanh Tran Duy , Kim Nam Hoon , Lee Joong Hee
Published: May 2016

The 3D NG/Co–NCNT based asymmetric supercapacitors provide high energy density (~88.44 W h kg−1), an ultra-high power density (~17 991 W kg−1 at 56.97 W h kg−1), and outstanding stability (~10 000 times).
Sub-100 nm TiO2 tubular architectures for efficient solar energy conversion
Authors: Samir Menna , Salama Mohamed , Allam Nageh K.
Published: May 2016

The smaller, the better: sub-100 nm tubes showed enhancement in the performance of solar energy conversion devices.
A fiber-shaped aqueous lithium ion battery with high power density
Authors: Zhang Ye , Wang Yuhang , Wang Lie , Lo Chieh-Min , Zhao Yang , Jiao Yiding , Zheng Gengfeng , Peng Huisheng
Published: May 2016

A fiber-shaped aqueous lithium ion battery is developed with ultrafast charge–discharge rates and high power density in addition to high energy density.
Fabrication of highly oriented 4H-SiC gourd-shaped nanowire arrays and their field emission properties
Authors: Chen Chunmei , Chen Shanliang , Shang Minghui , Gao Femgmei , Yang Zuobao , Liu Qiao , He Zhiyong , Yang Weiyou
Published: May 2016

We reported the large-scale fabrication of highly oriented 4H-SiC gourd-shaped nanowire nanoarrays with a low turn-on field of 0.95 V μm−1.
A facile hybrid approach to high-performance broadband antireflective thin films with humidity resistance as well as mechanical robustness
Authors: Li Tong , He Junhui
Published: May 2016

Broadband high transmittance, humidity resistance and mechanical robustness are three important aspects that dictate the practical applications of antireflective thin films.
The role of fibrinogen glycation in ATTR: evidence for chaperone activity loss in disease
Authors: Fonseca Daniel , Gilberto Samuel , Ribeiro-Silva Cristina , Ribeiro Raquel , Guinote Inês Batista , Saraiva Susana , Gomes Ricardo A. , Mateus Élia , Viana Ana , Barroso Eduardo , Freire Ana Ponces , Freire Patrick , Cordeiro Carlos , da Costa Gonçalo
Published: May 2016

Transthyretin amyloidosis (ATTR) belongs to a class of disorders caused by protein misfolding and aggregation. ATTR is a disabling disorder of autosomal dominant trait, where transthyretin (TTR) forms amyloid deposits in different organs, causing dysfunction of the peripheral nervous system. We previously discovered that amyloid fibrils from ATTR patients are glycated by methylglyoxal. Even though no consensus has been reached about the actual role of methylglyoxal-derived advanced glycation end-products in amyloid diseases, evidence collected so far points to a role for protein glycation in conformational abnormalities, being ubiquitously found in amyloid deposits in Alzheimer's disease, dialysis-related amyloidosis and Parkinson's diseases. Human fibrinogen, an extracellular chaperone, was reported to specifically interact with a wide spectrum of stressed proteins and suppress their aggregation, being an interacting protein with TTR. Fibrinogen is differentially glycated in ATTR, leading to its chaperone activity loss. Here we show the existence of a proteostasis imbalance in ATTR linked to fibrinogen glycation by methylglyoxal.
Training‐based head pose estimation under monocular vision
Authors: Guo Zhizhi , Zhou Qianxiang , Liu Zhongqi , Liu Chunhui
Published: May 2016

Although many 3D head pose estimation methods based on monocular vision can achieve an accuracy of 5°, how to reduce the number of required training samples and how to not to use any hardware parameters as input features are still among the biggest challenges in the field of head pose estimation. To aim at these challenges, the authors propose an accurate head pose estimation method which can act as an extension to facial key point detection systems. The basic idea is to use the normalised distance between key points as input features, and to use ℓ1‐minimisation to select a set of sparse training samples which can reflect the mapping relationship between the feature vector space and the head pose space. The linear combination of the head poses corresponding to these samples represents the head pose of the test sample. The experiment results show that the authors’ method can achieve an accuracy of 2.6° without any extra hardware parameters or information of the subject. In addition, in the case of large head movement and varying illumination, the authors’ method is still able to estimate the head pose.
Transport and trapping of dust particles in a potential well created by inductively coupled diffused plasmas
Authors: Choudhary Mangilal , Mukherjee S. , Bandyopadhyay P.
Published: May 2016

A versatile linear dusty (complex) plasma device is designed to study the transport and dynamical behavior of dust particles in a large volume. Diffused inductively coupled plasma is generated in the background of argon gas. A novel technique is used to introduce the dust particles in the main plasma by striking a secondary direct current glow discharge. These dust particles are found to get trapped in an electrostatic potential well, which is formed due to the combination of the ambipolar electric field caused by diffusive plasma and the field produced by the charged glass wall of the vacuum chamber. According to the requirements, the volume of the dust cloud can be controlled very precisely by tuning the plasma and discharge parameters. The present device can be used to address the underlying physics behind the transport of dust particles, self-excited dust acoustic waves, and instabilities. The detailed design of this device, plasma production and characterization, trapping and transport of the dust particle, and some of the preliminary experimental results are presented.
Assessment of the accuracy of coupled cluster perturbation theory for open-shell systems. II. Quadruples expansions
Authors: Eriksen Janus J. , Matthews Devin A. , Jørgensen Poul , Gauss Jürgen
Published: May 2016

We extend our assessment of the potential of perturbative coupled cluster (CC) expansions for a test set of open-shell atoms and organic radicals to the description of quadruple excitations. Namely, the second- through sixth-order models of the recently proposed CCSDT(Q–n) quadruples series [J. J. Eriksen et al., J. Chem. Phys. 140, 064108 (2014)] are compared to the prominent CCSDT(Q) and ΛCCSDT(Q) models. From a comparison of the models in terms of their recovery of total CC singles, doubles, triples, and quadruples (CCSDTQ) energies, we find that the performance of the CCSDT(Q–n) models is independent of the reference used (unrestricted or restricted (open-shell) Hartree-Fock), in contrast to the CCSDT(Q) and ΛCCSDT(Q) models, for which the accuracy is strongly dependent on the spin of the molecular ground state. By further comparing the ability of the models to recover relative CCSDTQ total atomization energies, the discrepancy between them is found to be even more pronounced, stressing how a balanced description of both closed- and open-shell species—as found in the CCSDT(Q–n) models—is indeed of paramount importance if any perturbative CC model is to be of chemical relevance for high-accuracy applications. In particular, the third-order CCSDT(Q–3) model is found to offer an encouraging alternative to the existing choices of quadruples models used in modern computational thermochemistry, since the model is still only of moderate cost, albeit markedly more costly than, e.g., the CCSDT(Q) and ΛCCSDT(Q) models.
Criteria for folding in structure-based models of proteins
Authors: Wołek Karol , Cieplak Marek
Published: May 2016

In structure-based models of proteins, one often assumes that folding is accomplished when all contacts are established. This assumption may frequently lead to a conceptual problem that folding takes place in a temperature region of very low thermodynamic stability, especially when the contact map used is too sparse. We consider six different structure-based models and show that allowing for a small, but model-dependent, percentage of the native contacts not being established boosts the folding temperature substantially while affecting the time scales of folding only in a minor way. We also compare other properties of the six models. We show that the choice of the description of the backbone stiffness has a substantial effect on the values of characteristic temperatures that relate both to equilibrium and kinetic properties. Models without any backbone stiffness (like the self-organized polymer) are found to perform similar to those with the stiffness, including in the studies of stretching.
Preferential concentration of heavy particles in compressible isotropic turbulence
Authors: Zhang Qingqing , Liu Han , Ma Zongqiang , Xiao Zuoli
Published: May 2016

Numerical simulations of particle-laden compressible isotropic turbulence with Taylor Reynolds number Reλ ∼ 100 are conducted by using a high-order turbulence solver, which is based on high-order compact finite difference method in the whole flow domain and localized artificial diffusivities for discontinuities. For simplicity, only one-way coupling (i.e., the influence of fluid on particles) between the carrier flow and particles is considered. The focus is on the study of the preferential concentration of heavy particles in dissipative scale of turbulence and the underlying mechanisms. Firstly, the effect of Stokes number (St) on the particle distribution in flow of Mach 1.01 (referred to as high-Mach-number case in this study) is investigated as a necessary supplementation for the previous studies in incompressible and weakly compressible flows. It turns out that heavy particles with Stokes number close to unity exhibit the strongest preferential concentration, which is in agreement with the observation in incompressible flow. All types of heavy particles have a tendency to accumulate in high-density regions of the background flow. While all kinds of particles dominantly collect in low-vorticity regions, intermediate and large particles (St = 1 and St = 5) are also found to collect in high-vorticity regions behind the randomly formed shocklets. Secondly, the impact of turbulent Mach number (Mt) (or the compressibility) of the carrier flow on the spatial distribution of the particles with St = 1 is discussed using the simulated compressible flows with Mt being 0.22, 0.68, and 1.01, respectively. In low-Mach-number flow, particles tend to concentrate in regions of low vorticity due to the centrifuge effect of vortices and particle concentration decreases monotonically with the increasing vorticity magnitude. As Mach number increases, the degree of particle clustering is slightly weakened in low-vorticity regions but is enhanced in high-vorticity regions, which only account for a small fraction of the flow domain. This observation as well as the anomalous correlation between the fluid density and vorticity can be ascribed to the appearance of randomly distributed shocklets in high-Mach-number turbulence, which enhance the vorticity and density (pressure) immediately behind them. Finally, the effects of the forcing and cooling schemes on the properties of flow and particles are also discussed.
Speckle-based at-wavelength metrology of X-ray mirrors with super accuracy
Authors: Kashyap Yogesh , Wang Hongchang , Sawhney Kawal
Published: May 2016

X-ray active mirrors, such as bimorph and mechanically bendable mirrors, are increasingly being used on beamlines at modern synchrotron source facilities to generate either focused or “tophat” beams. As well as optical tests in the metrology lab, it is becoming increasingly important to optimise and characterise active optics under actual beamline operating conditions. Recently developed X-ray speckle-based at-wavelength metrology technique has shown great potential. The technique has been established and further developed at the Diamond Light Source and is increasingly being used to optimise active mirrors. Details of the X-ray speckle-based at-wavelength metrology technique and an example of its applicability in characterising and optimising a micro-focusing bimorph X-ray mirror are presented. Importantly, an unprecedented angular sensitivity in the range of two nanoradians for measuring the slope error of an optical surface has been demonstrated. Such a super precision metrology technique will be beneficial to the manufacturers of polished mirrors and also in optimization of beam shaping during experiments.
Band structure of cavity-type hypersonic phononic crystals fabricated by femtosecond laser-induced two-photon polymerization
Authors: Rakhymzhanov A. M. , Gueddida A. , Alonso-Redondo E. , Utegulov Z. N. , Perevoznik D. , Kurselis K. , Chichkov B. N. , El Boudouti E. H. , Djafari-Rouhani B. , Fytas G.
Published: May 2016

The phononic band diagram of a periodic square structure fabricated by femtosecond laser pulse-induced two photon polymerization is recorded by Brillouin light scattering (BLS) at hypersonic (GHz) frequencies and computed by finite element method. The theoretical calculations along the two main symmetry directions quantitatively capture the band diagrams of the air- and liquid-filled structure and moreover represent the BLS intensities. The theory helps identify the observed modes, reveals the origin of the observed bandgaps at the Brillouin zone boundaries, and unravels direction dependent effective medium behavior.
Nano-metrology: The art of measuring X-ray mirrors with slope errors <100 nrad
Authors: Alcock Simon G. , Nistea Ioana , Sawhney Kawal
Published: May 2016

We present a comprehensive investigation of the systematic and random errors of the nano-metrology instruments used to characterize synchrotron X-ray optics at Diamond Light Source. With experimental skill and careful analysis, we show that these instruments used in combination are capable of measuring state-of-the-art X-ray mirrors. Examples are provided of how Diamond metrology data have helped to achieve slope errors of <100 nrad for optical systems installed on synchrotron beamlines, including: iterative correction of substrates using ion beam figuring and optimal clamping of monochromator grating blanks in their holders. Simulations demonstrate how random noise from the Diamond-NOM’s autocollimator adds into the overall measured value of the mirror’s slope error, and thus predict how many averaged scans are required to accurately characterize different grades of mirror.
Al-doped MgB2 materials studied using electron paramagnetic resonance and Raman spectroscopy
Authors: Bateni Ali , Erdem Emre , Repp Sergej , Weber Stefan , Somer Mehmet
Published: May 2016

Undoped and aluminum (Al) doped magnesium diboride (MgB2) samples were synthesized using a high-temperature solid-state synthesis method. The microscopic defect structures of Al-doped MgB2 samples were systematically investigated using X-ray powder diffraction, Raman spectroscopy, and electron paramagnetic resonance. It was found that Mg-vacancies are responsible for defect-induced peculiarities in MgB2. Above a certain level of Al doping, enhanced conductive properties of MgB2 disappear due to filling of vacancies or trapping of Al in Mg-related vacancy sites.
Comparison measurements of low-pressure between a laser refractometer and ultrasonic manometer
Authors: Egan Patrick F. , Stone Jack A. , Ricker Jacob E. , Hendricks Jay H.
Published: May 2016

We have developed a new low-pressure sensor which is based on the measurement of (nitrogen) gas refractivity inside a Fabry–Perot cavity. We compare pressure determinations via this laser refractometer to that of well-established ultrasonic manometers throughout the range 100 Pa to 180 000 Pa. The refractometer demonstrates 10−6 ⋅ p reproducibility for p > 100 Pa, and this precision outperforms a manometer. We also claim the refractometer has an expanded uncertainty of U(pFP) = [(2.0 mPa)2 + (8.8 × 10−6 ⋅ p)2]1/2, as realized through the properties of nitrogen gas; we argue that a transfer of the pascal to p < 1 kPa using a laser refractometer is more accurate than the current primary realization.
Signatures of asymmetry in neutron spectra and images predicted by three-dimensional radiation hydrodynamics simulations of indirect drive implosions
Authors: Chittenden J. P. , Appelbe B. D. , Manke F. , McGlinchey K. , Niasse N. P. L.
Published: May 2016

We present the results of 3D simulations of indirect drive inertial confinement fusion capsules driven by the “high-foot” radiation pulse on the National Ignition Facility. The results are post-processed using a semi-deterministic ray tracing model to generate synthetic deuterium-tritium (DT) and deuterium-deuterium (DD) neutron spectra as well as primary and down scattered neutron images. Results with low-mode asymmetries are used to estimate the magnitude of anisotropy in the neutron spectra shift, width, and shape. Comparisons of primary and down scattered images highlight the lack of alignment between the neutron sources, scatter sites, and detector plane, which limits the ability to infer the ρr of the fuel from a down scattered ratio. Further calculations use high bandwidth multi-mode perturbations to induce multiple short scale length flows in the hotspot. The results indicate that the effect of fluid velocity is to produce a DT neutron spectrum with an apparently higher temperature than that inferred from the DD spectrum and which is also higher than the temperature implied by the DT to DD yield ratio.
Thermal spike effect in sputtering of porous germanium to form surface pattern by high energy heavy ions irradiation
Authors: Hooda Sonu , Khan S. A. , Satpati B. , Kanjilal D. , Kabiraj D.
Published: May 2016

Germanium exhibits a remarkable effect when subjected to high energy heavy ions irradiation. A synergic effect of high electronic energy loss (Se = 16.4 keV nm−1) and nuclear energy loss (Sn = 0.1 keV nm−1) of 100 MeV Ag ions irradiation in Ge is presented. The results show that crystalline Ge is insensitive to the ionizing part of energy loss whereas thermal spike generated in the damaged Ge leads to the formation of porous structure. Further, an unusual high sputtering of the porous structure opens up the sub-surface voids to show the surface pattern. We explore the role of electron and phonon confinement to explain this effect.
Ratcheted electrophoresis of Brownian particles
Authors: Kowalik Mikołaj , Bishop Kyle J. M.
Published: May 2016

The realization of nanoscale machines requires efficient methods by which to rectify unbiased perturbations to perform useful functions in the presence of significant thermal noise. The performance of such Brownian motors often depends sensitively on their operating conditions—in particular, on the relative rates of diffusive and deterministic motions. In this letter, we present a type of Brownian motor that uses contact charge electrophoresis of a colloidal particle within a ratcheted channel to achieve directed transport or perform useful work against an applied load. We analyze the stochastic dynamics of this model ratchet to show that it functions under any operating condition—even in the limit of strong thermal noise and in contrast to existing ratchets. The theoretical results presented here suggest that ratcheted electrophoresis could provide a basis for electrochemically powered, nanoscale machines capable of transport and actuation of nanoscale components.
Avalanche proton-boron fusion based on elastic nuclear collisions
Authors: Eliezer Shalom , Hora Heinrich , Korn Georg , Nissim Noaz , Martinez Val Josè Maria
Published: May 2016

Recent experiments done at Prague with the 600 J/0.2 ns PALS laser interacting with a layer of boron dopants in a hydrogen enriched target have produced around 109 alphas. We suggest that these unexpected very high fusion reactions of proton with 11B indicate an avalanche multiplication for the measured anomalously high nuclear reaction yields. This can be explained by elastic nuclear collisions in the broad 600 keV energy band, which is coincident with the high nuclear p-11B fusion cross section, by the way of multiplication through generation of three secondary alpha particles from a single primarily produced alpha particle.
Dissociative diffusion mechanism in vacancy-rich materials according to mass action kinetics
Authors: Biderman N. J. , Sundaramoorthy R. , Haldar Pradeep , Lloyd J. R.
Published: May 2016

Two sets of diffusion-reaction numerical simulations using a finite difference method (FDM) were conducted to investigate fast impurity diffusion via interstitial sites in vacancy-rich materials such as Cu(In,Ga)Se2 (CIGS) and Cu2ZnSn(S, Se)4 (CZTSSe or CZTS) via the dissociative diffusion mechanism where the interstitial diffuser ultimately reacts with a vacancy to produce a substitutional. The first set of simulations extends the standard interstitial-limited dissociative diffusion theory to vacancy-rich material conditions where vacancies are annihilated in large amounts, introducing non-equilibrium vacancy concentration profiles. The second simulation set explores the vacancy-limited dissociative diffusion where impurity incorporation increases the equilibrium vacancy concentration. In addition to diffusion profiles of varying concentrations and shapes that were obtained in all simulations, some of the profiles can be fitted with the constant- and limited-source solutions of Fick’s second law despite the non-equilibrium condition induced by the interstitial-vacancy reaction. The first set of simulations reveals that the dissociative diffusion coefficient in vacancy-rich materials is inversely proportional to the initial vacancy concentration. In the second set of numerical simulations, impurity-induced changes in the vacancy concentration lead to distinctive diffusion profile shapes. The simulation results are also compared with published data of impurity diffusion in CIGS. According to the characteristic properties of diffusion profiles from the two set of simulations, experimental detection of the dissociative diffusion mechanism in vacancy-rich materials may be possible.
Modulation of water surface waves with a coiling-up-space metasurface
Authors: Sun H. T. , Wang J. S. , Cheng Y. , Wei Q. , Liu X. J.
Published: May 2016

We have designed a gradient-index (GRIN) metasurface to modulate water surface waves (WSWs). The metasurface is composed of an array of coiling-up-space units with a deep sub-wavelength scale, and can focus/scatter WSWs when the units are arranged elaborately and pierced into water. The modulation of WSWs has been ascribed to the relative effective refractive GRIN of the coiling-up-space units, which can be tuned by changing the parameters such as the plate length of units. This work may have potential application in energy extraction of water wave.
Raman Spectra of Liquid Nitromethane under Singly Shocked Conditions
Authors: Wang Ya-ping , Liu Fu-sheng , Liu Qi-jun , Zhang Ning-chao
Published: May 2016

Raman spectra of liquid nitromethane were measured in single-shock experiments using transient Raman scattering system with high sensitivity. The measurement system was combined with a two-stage light gas gun to interrogate the vibrational mode-dependent behaviors of shock-compressed nitromethane molecules. Up to 12 GPa, all Raman peaks were able to be clearly detected, and showed the shock-induced shifting and broadening, but no signs of chemical changes occurred in the sample. Thus, it is concluded that chemical reactions could not be initiated in singly-shocked nitromethane below 12 GPa.
Photocatalytic Activity Improvement of g-C3N4 under Visible Light by Optimizing Preparation Conditions
Authors: Hu Jian-yang , Zhu Guo-li
Published: May 2016

Graphite-like C3N4 (g-C3N4) is an efficient visible-light-driven photocatalyst which is commonly used in pollutant degradation. The photoreactivity of g-C3N4 depends on the preparation conditions to a large extent. In this work, we linked the preparation conditions of g-C3N4 to its stability and photocatalytic activity through dye photodegradation experiments and sensitivity mathematical analyses. The sensitivity mathematical analyses show that the effect of calcination temperature is more significant than calcination time on the photoreactivity of g-C3N4. The photocatalytic activity of optimized g-C3N4 in rhodamine B (RhB) degradation under visible light was 100 times higher than that of non-optimized one. The enhanced performance can be attributed to the increased specific surface area of g-C3N4 and the increased migration velocity of photogenerated electron-hole pairs on the surface. This work deepens the understanding of the relation between preparation conditions and the charateristics of g-C3N4, and provides an extremely simple method for significantly improving the photoreactivity of g-C3N4.