bluuebunny/crossref_metadata_2025 huggingface dataset:
Iridium nanoparticles supported on hierarchical porous N-doped carbon: an efficient water-tolerant catalyst for bio-alcohol condensation in water
Authors: Liu Di , Chen Xiufang , Xu Guoqiang , Guan Jing , Cao Quan , Dong Bo , Qi Yunfei , Li Chunhu , Mu Xindong
Published: February 2016

Nitrogen-doped hierarchical porous carbons were synthesized successfully by a controllable one-pot method using glucose and dicyandiamide as carbon source and nitrogen source via hydrothermal carbonization process. The nitrogen-doped materials, possessing high nitrogen content (up to 7 wt%), large surface area (>320 m2 g−1) and excellent hierarchical nanostructure, were employed as catalyst supports for immobilization of iridium nanoparticles for bio-alcohol condensation in water. The introduction of nitrogen atoms into the carbon framework significantly improved iridium nanoparticles dispersion and stabilization. The novel iridium catalysts exhibited superior catalytic activity in the aqueous phase condensation of butanol, offering high butanol conversion of 45% with impressive 2-ethylhexanol selectivity of 97%. The heterogeneous catalysts had great advantages of easy recovery and high catalytic stability. The outstanding catalytic performance could be attributed to excellent dispersion of iridium nanoparticles, stronger iridium-support interactions and interaction of nitrogen species with alcohol substrates.
Inhibition of the STAT3 signaling pathway contributes to apigenin-mediated anti-metastatic effect in melanoma
Authors: Cao Hui-Hui , Chu Jian-Hong , Kwan Hiu-Yee , Su Tao , Yu Hua , Cheng Chi-Yan , Fu Xiu-Qiong , Guo Hui , Li Ting , Tse Anfernee Kai-Wing , Chou Gui-Xin , Mo Huan-Biao , Yu Zhi-Ling
Published: February 2016

Signal transducer and activator of transcription 3 (STAT3) signaling is constantly activated in human melanoma, and promotes melanoma metastasis. The dietary flavonoid apigenin is a bioactive compound that possesses low toxicity and exerts anti-metastatic activity in melanoma. However, the anti-metastasis mechanism of apigenin has not been fully elucidated. In the present study, we showed that apigenin suppressed murine melanoma B16F10 cell lung metastasis in mice, and inhibited cell migration and invasion in human and murine melanoma cells. Further study indicated that apigenin effectively suppressed STAT3 phosphorylation, decreased STAT3 nuclear localization and inhibited STAT3 transcriptional activity. Apigenin also down-regulated STAT3 target genes MMP-2, MMP-9, VEGF and Twist1, which are involved in cell migration and invasion. More importantly, overexpression of STAT3 or Twist1 partially reversed apigenin-impaired cell migration and invasion. Our data not only reveal a novel anti-metastasis mechanism of apigenin but also support the notion that STAT3 is an attractive and promising target for melanoma treatment.
Erratum: Lactate Chemical Exchange Saturation Transfer (LATEST) Imaging in vivo: A Biomarker for LDH Activity
Authors: DeBrosse Catherine , Nanga Ravi Prakash Reddy , Bagga Puneet , Nath Kavindra , Haris Mohammad , Marincola Francesco , Schnall Mitchell D. , Hariharan Hari , Reddy Ravinder
Published: February 2016

Scientific Reports 6: Article number: 19517; published online: 22 January 2016; updated: 25 February 2016. The original version of this Article contained an error in the title of the paper, where “Lactate Chemical Exchange Saturation Transfer (LATEST) Imaging in vivo: A Biomarker for LDH Activity” was incorrectly given as “Lactate Chemical Exchange Saturation Transfer (LATEST) Imaging in vivo A Biomarker for LDH Activity”.
Infants and elderlies are susceptible to zinc deficiency
Authors: Yasuda Hiroshi , Tsutsui Toyoharu
Published: February 2016

The importance of zinc for human health has been recognized since the early 1960s, but today there is little concern about zinc deficiency in developed countries. In this study, we measured the zinc concentration in hair from 28,424 Japanese subjects (18,812 females and 9,612 males) and found that 1,754 subjects (6.17%) had zinc concentrations lower than 2 standard deviations (86.3 ppm) below the control reference range, which qualifies as zinc deficiency. In particular, a considerable proportion of elderlies and children (20% or more) were found to have marginal to severe zinc deficiency. A zinc concentration of 9.7 ppm was the lowest observed in a 51-year-old woman; this concentration was approximately 1/13 of the mean reference level. The prevalence of zinc deficiency in adults increased with aging to a maximum of 19.7% by the 8th decade of life and decreased to 3.4% above 90-year-old. The proportion of zinc deficiency in infants 0–4 years was 36.5% in males and 47.3% in females; these percentages were higher than the maximum prevalence in elderly subjects. These findings suggest that infants and elderlies are prone to zinc deficiency and that intervention of zinc deficiency is necessary for normal human development, health and longevity.
Generation of “perfect” vortex of variable size and its effect in angular spectrum of the down-converted photons
Authors: Jabir M. V. , Apurv Chaitanya N. , Aadhi A. , Samanta G. K.
Published: February 2016

The “perfect” vortex is a new class of optical vortex beam having ring radius independent of its topological charge (order). One of the simplest techniques to generate such beams is the Fourier transformation of the Bessel-Gauss beams. The variation in ring radius of such vortices require Fourier lenses of different focal lengths and or complicated imaging setup. Here we report a novel experimental scheme to generate perfect vortex of any ring radius using a convex lens and an axicon. As a proof of principle, using a lens of focal length f = 200 mm, we have varied the radius of the vortex beam across 0.3–1.18 mm simply by adjusting the separation between the lens and axicon. This is also a simple scheme to measure the apex angle of an axicon with ease. Using such vortices we have studied non-collinear interaction of photons having orbital angular momentum (OAM) in spontaneous parametric down-conversion (SPDC) process and observed that the angular spectrum of the SPDC photons are independent of OAM of the pump photons rather depends on spatial profile of the pump beam. In the presence of spatial walk-off effect in nonlinear crystals, the SPDC photons have asymmetric angular spectrum with reducing asymmetry at increasing vortex radius.
Spatio-temporal co-ordination of RhoA, Rac1 and Cdc42 activation during prototypical edge protrusion and retraction dynamics
Authors: Martin Katrin , Reimann Andreas , Fritz Rafael D. , Ryu Hyunryul , Jeon Noo Li , Pertz Olivier
Published: February 2016

The three canonical Rho GTPases RhoA, Rac1 and Cdc42 co-ordinate cytoskeletal dynamics. Recent studies indicate that all three Rho GTPases are activated at the leading edge of motile fibroblasts, where their activity fluctuates at subminute time and micrometer length scales. Here, we use a microfluidic chip to acutely manipulate fibroblast edge dynamics by applying pulses of platelet-derived growth factor (PDGF) or the Rho kinase inhibitor Y-27632 (which lowers contractility). This induces acute and robust membrane protrusion and retraction events, that exhibit stereotyped cytoskeletal dynamics, allowing us to fairly compare specific morphodynamic states across experiments. Using a novel Cdc42, as well as previously described, second generation RhoA and Rac1 biosensors, we observe distinct spatio-temporal signaling programs that involve all three Rho GTPases, during protrusion/retraction edge dynamics. Our results suggest that Rac1, Cdc42 and RhoA regulate different cytoskeletal and adhesion processes to fine tune the highly plastic edge protrusion/retraction dynamics that power cell motility.
A route to self-assemble suspended DNA nano-complexes
Authors: Lansac Yves , Degrouard Jeril , Renouard Madalena , Toma Adriana C. , Livolant Françoise , Raspaud Eric
Published: February 2016

Highly charged polyelectrolytes can self-assemble in presence of condensing agents such as multivalent cations, amphiphilic molecules or proteins of opposite charge. Aside precipitation, the formation of soluble micro- and nano-particles has been reported in multiple systems. However a precise control of experimental conditions needed to achieve the desired structures has been so far hampered by the extreme sensitivity of the samples to formulation pathways. Herein we combine experiments and molecular modelling to investigate the detailed microscopic dynamics and the structure of self-assembled hexagonal bundles made of short dsDNA fragments complexed with small basic proteins. We suggest that inhomogeneous mixing conditions are required to form and stabilize charged self-assembled nano-aggregates in large excess of DNA. Our results should help re-interpreting puzzling behaviors reported for a large class of strongly charged polyelectrolyte systems.
Efficient design, accurate fabrication and effective characterization of plasmonic quasicrystalline arrays of nano-spherical particles
Authors: Namin Farhad A. , Yuwen Yu A. , Liu Liu , Panaretos Anastasios H. , Werner Douglas H. , Mayer Theresa S.
Published: February 2016

In this paper, the scattering properties of two-dimensional quasicrystalline plasmonic lattices are investigated. We combine a newly developed synthesis technique, which allows for accurate fabrication of spherical nanoparticles, with a recently published variation of generalized multiparticle Mie theory to develop the first quantitative model for plasmonic nano-spherical arrays based on quasicrystalline morphologies. In particular, we study the scattering properties of Penrose and Ammann- Beenker gold spherical nanoparticle array lattices. We demonstrate that by using quasicrystalline lattices, one can obtain multi-band or broadband plasmonic resonances which are not possible in periodic structures. Unlike previously published works, our technique provides quantitative results which show excellent agreement with experimental measurements.
Anti-Microbial Dendrimers against Multidrug-Resistant P. aeruginosa Enhance the Angiogenic Effect of Biological Burn-wound Bandages
Authors: Abdel-Sayed Philippe , Kaeppeli Ariane , Siriwardena Thissa , Darbre Tamis , Perron Karl , Jafari Paris , Reymond Jean-Louis , Pioletti Dominique P. , Applegate Lee Ann
Published: February 2016

Multi-drug resistant Pseudomonas aeruginosa has increased progressively and impedes further regression in mortality in burn patients. Such wound infections serve as bacterial reservoir for nosocomial infections and are associated with significant morbidity and costs. Anti-microbial polycationic dendrimers G3KL and G3RL, able to kill multi-drug resistant P. aeruginosa, have been previously developed. The combination of these dendrimers with a class of biological bandages made of progenitor skin cells, which secrete growth factors, could positively impact wound-healing processes. However, polycations are known to be used as anti-angiogenic agents for tumor suppression. Since, neovascularization is pivotal in the healing of deep burn-wounds, the use of anti-microbial dendrimers may thus hinder the healing processes. Surprisingly, we have seen in this study that G3KL and G3RL dendrimers can have angiogenic effects. Moreover, we have shown that a dendrimer concentration ranging between 50 and 100 μg/mL in combination with the biological bandages can suppress bacterial growth without altering cell viability up to 5 days. These results show that antimicrobial dendrimers can be used in combination with biological bandages and could potentially improve the healing process with an enhanced angiogenesis.
CRISPR/Cas9-mediated GJA8 knockout in rabbits recapitulates human congenital cataracts
Authors: Yuan Lin , Sui Tingting , Chen Mao , Deng Jichao , Huang Yongye , Zeng Jian , Lv Qingyan , Song Yuning , Li Zhanjun , Lai Liangxue
Published: February 2016

Cataracts are the leading cause of vision loss in the world, although surgical treatment can restore vision in cataract patients. Until now, there have been no adequate animal models for in vivo studies of artificial lens safety and drug interactions. Genetic studies have demonstrated that GJA8 is involved in maintaining lens opacity and proper lens development. In this study, a cataract model with GJA8 gene knockout was developed via co-injection of Cas9/sgRNA mRNA into rabbit zygotes. Our results showed that gene mutation efficiency in the GJA8 locus reached 98.7% in embryos and 100% in pups, demonstrating that the Cas9/sgRNA system is a highly efficient tool for gene editing in rabbits. In agreement with other studies, our genetic and histology results showed that impaired GJA8 function caused microphthalmia, small lens size and cataracts. In summary, our novel rabbit model of cataracts will be an important drug-screening tool for cataract prevention and treatment.
Unraveling the role of dark septate endophyte (DSE) colonizing maize (Zea mays) under cadmium stress: physiological, cytological and genic aspects
Authors: Wang Jun-ling , Li Tao , Liu Gao-yuan , Smith Joshua M. , Zhao Zhi-wei
Published: February 2016

A growing body of evidence suggests that plant root-associated fungi such as dark septate endophytes (DSE) can help plants overcome many biotic and abiotic stresses, of great interest is DSE-plant metal tolerance and alleviation capabilities on contaminated soils. However, the tolerance and alleviation mechanisms involved have not yet been elucidated. In the current study, the regulation and physiological response of Zea mays to its root-associated DSE, Exophiala pisciphila was analyzed under increased soil Cd stress (0, 10, 50, 100 mg kg−1). Under Cd stress, DSE inoculation significantly enhanced the activities of antioxidant enzymes and low-molecular weight antioxidants, while also inducing increased Cd accumulation in the cell wall and conversion of Cd into inactive forms by shoot and root specific regulation of genes related to metal uptake, translocation and chelation. Our results showed that DSE colonization resulted in a marked tolerance to Cd, with a significant decrease in cadmium phytotoxicity and a significant increase in maize growth by triggering antioxidant systems, altering metal chemical forms into inactive Cd, and repartitioning subcellular Cd into the cell wall. These results provide comprehensive evidence for the mechanisms by which DSE colonization bioaugments Cd tolerance in maize at physiological, cytological and molecular levels.
Assessing the Causality between Blood Pressure and Retinal Vascular Caliber through Mendelian Randomisation
Authors: Li Ling-Jun , Liao Jiemin , Cheung Carol Yim-Lui , Ikram M. Kamran , Shyong Tai E. , Wong Tien-Yin , Cheng Ching-Yu
Published: February 2016

We aimed to determine the association between blood pressure (BP) and retinal vascular caliber changes that were free from confounders and reverse causation by using Mendelian randomisation. A total of 6528 participants from a multi-ethnic cohort (Chinese, Malays, and Indians) in Singapore were included in this study. Retinal arteriolar and venular caliber was measured by a semi-automated computer program. Genotyping was done using Illumina 610-quad chips. Meta-analysis of association between BP, and retinal arteriolar and venular caliber across three ethnic groups was performed both in conventional linear regression and Mendelian randomisation framework with a genetic risk score of BP as an instrumental variable. In multiple linear regression models, each 10 mm Hg increase in systolic BP, diastolic BP, and mean arterial BP (MAP) was associated with significant decreases in retinal arteriolar caliber of a 1.4, 3.0, and 2.6 μm, and significant decreases in retinal venular caliber of a 0.6, 0.7, and 0.9 μm, respectively. In a Mendelian randomisation model, only associations between DBP and MAP and retinal arteriolar narrowing remained yet its significance was greatly reduced. Our data showed weak evidence of a causal relationship between elevated BP and retinal arteriolar narrowing.
Optically-Induced Cell Fusion on Cell Pairing Microstructures
Authors: Yang Po-Fu , Wang Chih-Hung , Lee Gwo-Bin
Published: February 2016

Cell fusion is a critical operation for numerous biomedical applications including cell reprogramming, hybridoma formation, cancer immunotherapy and tissue regeneration. However, unstable cell contact and random cell pairings have limited efficiency and yields when utilizing traditional methods. Furthermore, it is challenging to selectively perform cell fusion within a group of cells. This study reports a new approach called optically-induced cell fusion (OICF), which integrates cell-pairing microstructures with an optically-induced, localized electrical field. By projecting light patterns onto a photoconductive film (hydrogen-rich, amorphous silicon) coated on an indium-tin-oxide (ITO) glass while an alternating current electrical field was applied between two such ITO glass slides, “virtual” electrodes could be generated that could selectively fuse pairing cells. At 10 kHz, a 57% cell paring rate and an 87% fusion efficiency were successfully achieved at a driving voltage of 20  Vpp, suggesting that this new technology could be promising for selective cell fusion within a group of cells.
Enduring voice recognition in bonobos
Authors: Keenan Sumir , Mathevon Nicolas , Stevens Jeroen MG , Guéry Jean Pascal , Zuberbühler Klaus , Levréro Florence
Published: February 2016

Long-term social recognition is vital for species with complex social networks, where familiar individuals can encounter one another after long periods of separation. For non-human primates who live in dense forest environments, visual access to one another is often limited and recognition of social partners over distances largely depends on vocal communication. Vocal recognition after years of separation has never been reported in any great ape species, despite their complex societies and advanced social intelligence. Here we show that bonobos, Pan paniscus, demonstrate reliable vocal recognition of social partners, even if they have been separated for five years. We experimentally tested bonobos’ responses to the calls of previous group members that had been transferred between captive groups. Despite long separations, subjects responded more intensely to familiar voices than to calls from unknown individuals - the first experimental evidence that bonobos can identify individuals utilising vocalisations even years after their last encounter. Our study also suggests that bonobos may cease to discriminate between familiar and unfamiliar individuals after a period of eight years, indicating that voice representations or interest could be limited in time in this species.
Prognostic significance of neutrophil-to-lymphocyte ratio in prostate cancer: evidence from 16,266 patients
Authors: Gu Xiaobin , Gao Xianshu , Li Xiaoying , Qi Xin , Ma Mingwei , Qin Shangbin , Yu Hao , Sun Shaoqian , Zhou Dong , Wang Wen
Published: February 2016

This study was aimed to investigate the prognostic value of neutrophil-to-lymphocyte ratio (NLR) in patients with prostate cancer (PCa). A meta-analysis including 14 publications (15 cohorts) with 16,266 patients was performed to evaluate the association between NLR and overall survival (OS), progression-free survival (PFS)/recurrence-free survival (RFS) in PCa using hazard ratio (HR) and 95% confidence intervals (95% CI). The combining data showed that increased NLR predict poor OS (HR = 1.38, 95%CI: 1.22–1.56) and PFS/RFS (HR = 1.24, 95%CI 1.05–1.46) in PCa. Stratified analysis by PCa type, sample size, ethnicity and NLR cut-off value revealed that NLR showed consistent prognostic value in metastatic castration-resistant prostate cancer (mCRPC) patients and predict poor PFS/RFS in Asians, but not in Caucasians. These statistical data suggested that increased NLR could predict poor prognosis in patients with PCa.
Inactivated poliovirus type 2 vaccine delivered to rat skin via high density microprojection array elicits potent neutralising antibody responses
Authors: Muller David A. , Pearson Frances E. , Fernando Germain J.P. , Agyei-Yeboah Christiana , Owens Nick S. , Corrie Simon R. , Crichton Michael L. , Wei Jonathan C.J. , Weldon William C. , Oberste M. Steven , Young Paul R. , Kendall Mark A. F.
Published: February 2016

Polio eradication is progressing rapidly and the live attenuated Sabin strains in the oral poliovirus vaccine (OPV) are being removed sequentially, starting with type 2 in April 2016. For risk mitigation, countries are introducing inactivated poliovirus vaccine (IPV) into routine vaccination programs. After April 2016, monovalent type 2 OPV will be available for type 2 outbreak control. Because the current IPV is not suitable for house-to-house vaccination campaigns (the intramuscular injections require health professionals), we developed a high-density microprojection array, the Nanopatch, delivered monovalent type 2 IPV (IPV2) vaccine to the skin. To assess the immunogenicity of the Nanopatch, we performed a dose-matched study in rats, comparing the immunogenicity of IPV2 delivered by intramuscular injection or Nanopatch immunisation. A single dose of 0.2 D-antigen units of IPV2 elicited protective levels of poliovirus antibodies in 100% of animals. However, animals receiving IPV2 by IM required at least 3 immunisations to reach the same neutralising antibody titres. This level of dose reduction (1/40th of a full dose) is unprecedented for poliovirus vaccine delivery. The ease of administration coupled with the dose reduction observed in this study points to the Nanopatch as a potential tool for facilitating inexpensive IPV for mass vaccination campaigns.
The Synthetic Tie2 Agonist Peptide Vasculotide Protects Renal Vascular Barrier Function In Experimental Acute Kidney Injury
Authors: Rübig Eva , Stypmann Jörg , Van Slyke Paul , Dumont Daniel J , Spieker Tilmann , Buscher Konrad , Reuter Stefan , Goerge Tobias , Pavenstädt Hermann , Kümpers Philipp
Published: February 2016

Microvascular barrier dysfunction plays a major role in the pathophysiology of acute kidney injury (AKI). Angiopoietin-1, the natural agonist ligand for the endothelial-specific Tie2 receptor, is a non-redundant endothelial survival and vascular stabilization factor. Here we evaluate the efficacy of a polyethylene glycol-clustered Tie2 agonist peptide, vasculotide (VT), to protect against endothelial-cell activation with subsequent microvascular dysfunction in a murine model of ischemic AKI. Renal ischemia reperfusion injury (IRI) was induced by clamping of the renal arteries for 35 minutes. Mice were treated with VT or PEGylated cysteine before IRI. Sham-operated animals served as time-matched controls. Treatment with VT significantly reduced transcapillary albumin flux and renal tissue edema after IRI. The protective effects of VT were associated with activation of Tie2 and stabilization of its downstream effector, VE-cadherin in renal vasculature. VT abolished the decline in renal tissue blood flow, attenuated the increase of serum creatinine and blood urea nitrogen after IRI, improved recovery of renal function and markedly reduced mortality compared to PEG [HR 0.14 (95% CI 0.05–0.78) P < 0.05]. VT is inexpensive to produce, chemically stable and unrelated to any Tie2 ligands. Thus, VT may represent a novel therapy to prevent AKI in patients.
The evolutionary history of genes involved in spoken and written language: beyond FOXP2
Authors: Mozzi Alessandra , Forni Diego , Clerici Mario , Pozzoli Uberto , Mascheretti Sara , Guerini Franca R. , Riva Stefania , Bresolin Nereo , Cagliani Rachele , Sironi Manuela
Published: February 2016

Humans possess a communication system based on spoken and written language. Other animals can learn vocalization by imitation, but this is not equivalent to human language. Many genes were described to be implicated in language impairment (LI) and developmental dyslexia (DD), but their evolutionary history has not been thoroughly analyzed. Herein we analyzed the evolution of ten genes involved in DD and LI. Results show that the evolutionary history of LI genes for mammals and aves was comparable in vocal-learner species and non-learners. For the human lineage, several sites showing evidence of positive selection were identified in KIAA0319 and were already present in Neanderthals and Denisovans, suggesting that any phenotypic change they entailed was shared with archaic hominins. Conversely, in FOXP2, ROBO1, ROBO2, and CNTNAP2 non-coding changes rose to high frequency after the separation from archaic hominins. These variants are promising candidates for association studies in LI and DD.
A novel electrochemical sensor based on a glassy carbon electrode modified with Cu–MWCNT nanocomposites for determination of hydroquinone
Authors: Yao Youzhi , Liu Yunchun , Yang Zhousheng
Published: February 2016

A new electrochemical sensor based on copper nanoparticles (Cu NPs) and multi-walled carbon nanotubes (MWCNTs) was fabricated for the determination of hydroquinone (HQ).
Molecular imaging probes derived from natural peptides
Authors: Charron C. L. , Hickey J. L. , Nsiama T. K. , Cruickshank D. R. , Turnbull W. L. , Luyt L. G.
Published: February 2016

Natural peptides possess a unique target specificity for their endogenous receptor that allows them to be exploited as diagnostic and therapeutic agents. This has led to the discovery and derivatization of various natural peptides into molecular imaging agents.
Novel non-hydrolytic templated sol–gel synthesis of mesoporous aluminosilicates and their use as aminolysis catalysts
Authors: Skoda David , Styskalik Ales , Moravec Zdenek , Bezdicka Petr , Babiak Michal , Klementova Mariana , Barnes Craig E. , Pinkas Jiri
Published: February 2016

A novel non-hydrolytic sol–gel (NHSG) synthesis of mesoporous aluminosilicate xerogels is presented.
PEG/heparin-decorated lipid–polymer hybrid nanoparticles for long-circulating drug delivery
Authors: Sheng Yan , Chang Lingqian , Kuang Tairong , Hu Jiaming
Published: February 2016

Surface modification of lipid–polymer hybrid nanoparticles with the combined PEG and heparin was developed to achieve a significant prolongation in blood circulation.
Green synthesis of vertical graphene nanosheets and their application in high-performance supercapacitors
Authors: Ouyang Bo , Zhang Yongqi , Zhang Zheng , Fan Hong Jin , Rawat R. S.
Published: February 2016

The MnO2 anchored fully covered vertical graphene nanosheets (f-VGS) based electrode produced using an environmentally-friendly approach exhibits enhanced supercapacitive performance.
Carbonyl scavenging and chemical chaperon like function of essential amino acids attenuates non-enzymatic glycation of albumin
Authors: Awasthi Saurabh , Saraswathi N. T.
Published: February 2016

Essential amino acids showed potent antiglycation activity by preventing formation of both early and advanced glycation end products (AGEs).
Improvement of the cyclic deterioration and structural evolution of Li[Li0.2Ni0.2Mn0.6]O2 cathode material by controlling initial charging voltages
Authors: Yan Wuwei , Liu Yongning , Chong Shaokun , Wu Yi-Fang
Published: February 2016

The initial stepwise charging suppresses oxygen release and restrains the layered to spinel phase transformation.
Online electrochemical system as an in vivo method to study dynamic changes of ascorbate in rat brain during 3-methylindole-induced olfactory dysfunction
Authors: Li Lijuan , Zhang Yinghong , Hao Jie , Liu Junxiu , Yu Ping , Ma Furong , Mao Lanqun
Published: February 2016

This study demonstrates the application of an OECS as an in vivo method to investigate the dynamic change of ascorbate in the olfactory bulb of rats during the acute period of olfactory dysfunction.
One-pot synthesis of single-crystalline PtPb nanodendrites with enhanced activity for electrooxidation of formic acid
Authors: Qu Ximing , Cao Zhenming , Zhang Binwei , Tian XiaoChun , Zhu Fuchun , Zhang Zongcheng , Jiang Yanxia , Sun Shigang
Published: February 2016

Bimetallic PtPb nanodendrites with a single-crystalline structure were obtained by a facile one-pot strategy.
Magnetically recoverable Cu0/Fe3O4catalyzed highly regioselective synthesis of 2,3,4-trisubstituted pyrroles from unactivated terminal alkynes and isocyanides
Authors: Tiwari Dipak Kumar , Phanindrudu Mandalaparthi , Aravilli Vinod Kumar , Sridhar B. , Likhar Pravin R. , Tiwari Dharmendra Kumar
Published: February 2016

An efficient, one pot tandem, Cu0/Fe3O4catalyzed highly regioselective synthesis of 2,3,4-trisubstituted pyrroles from unactivated terminal alkynes and isocyanides.
External orthogonality in subsystem time-dependent density functional theory
Authors: Chulhai Dhabih V. , Jensen Lasse
Published: February 2016

We present a subsystem TDDFT method which maintains inter-subsystem orbital orthogonality.
Identification of an active metabolite of PAR-1 antagonist RWJ-58259 and synthesis of analogues to enhance its metabolic stability
Authors: Robinson Eifion , Knight Emily , Smoktunowicz Natalia , Chambers Rachel C. , Inglis Graham G. , Chudasama Vijay , Caddick Stephen
Published: February 2016

Understanding the pharmacokinetic behaviour of PAR-1 antagonist RWJ-58259 and the synthesis of analogues to enhance metabolic stability.
An atom-efficient and convergent approach to the preparation of NS5A inhibitors by C–H activation
Authors: Moore Thomas O. , Paradowski Michael , Ward Simon E.
Published: February 2016

A novel approach of the convergent functionalisation of aryl dibromides to form NS5A type inhibitors using C–H activation is reported.
Self-assembled fluorodendrimers in the co-delivery of fluorinated drugs and therapeutic genes
Authors: Wang Hui , Hu Jingjing , Cai Xiaopan , Xiao Jianru , Cheng Yiyun
Published: February 2016

A fluorodendrimer enables the co-delivery of fluorinated anticancer drugs and therapeutic genes for synergistic cancer therapy.
Phototriggered supramolecular polymerization of a [c2]daisy chain rotaxane
Authors: Fu Xin , Gu Rui-Rui , Zhang Qi , Rao Si-Jia , Zheng Xiu-Li , Qu Da-Hui , Tian He
Published: February 2016

The supramolecular polymerization of a [c2]daisy chain rotaxane monomer can be triggered by light via a photocleavage mechanism.
Electrochemical synthesis of a nanohybrid film consisting of stacked graphene sheets and manganese oxide as oxygen evolution reaction catalyst
Authors: Nakayama Masaharu , Fujii Yusuke , Fujimoto Kotaro , Yoshimoto Makoto , Kaide Aya , Saeki Takashi , Asada Hironori
Published: February 2016

A new electrochemical process yielded a thin film consisting of stacked graphene sheets and manganese oxide effective for oxygen evolution reaction.
π-Bonding-dominated energy gaps in graphene oxide
Authors: Thuy Tran Ngoc Thanh , Lin Shih-Yang , Glukhova Olga E. , Lin Ming-Fa
Published: February 2016

The chemical bonding in graphene oxide with oxygen concentrations from 50% to 1% is investigated using first-principle calculations.
Characterization and application of a novel inorganic polymer coagulant: polytianium-silicate-chloride
Authors: Huang Xin , Gao Baoyu , Yue Qinyan , Wang Yan , Li Qian
Published: February 2016

A novel inorganic polymer coagulant, polytitanium-silicate-chloride, was synthesized by two approaches: (1) hydroxylation of a mixture of TiCl4 and fresh polysilicic acid; (2) hydroxylated polytitanium chloride combined with polysilicic acid was aged for 2 h.
Synthesis and photoluminescence modulating of polypyrrole fluorescent nano-spheres/dots
Authors: Dong Ben , Yang Mei , Ge Shusheng , Cao Yi , Li Baoyan , Lu Yun
Published: February 2016

Polypyrrole fluorescent nanospheres/dots with tunable band gaps have been successfully synthesized, which showed the outstanding characteristics of low cytotoxicity, good biocompatibility and high luminescence stability.
Honeycomb-shaped magnetic multilayer thin films for cell trapping
Authors: Huang Chen-Yu , Chang Wei-Chieh , Yeh Kun-Chieh , Tseng Han-Yi , Hsu Ming-Shinn , Chen Jiann-Yeu , Wei Zung-Hang
Published: February 2016

Honeycomb-shaped magnetic thin films with domain wall (DW) pinning geometry are designed to actively trap magnetically labeled cells.
A sensitive electrochemiluminescent immunosensor based on 3D-flower-like MoS2microspheres and using AuPt nanoparticles for signal amplification
Authors: Wang Xiu , Shen Lei , Deng Wenping , Yan Mei , Liu Haiyun , Ge Shenguang , Yu Jinghua , Song Xianrang
Published: February 2016

We herein report the synthesis of MoS2which was three-dimensional flower-like microspheres, and then the prepared GOx–AuPt and MoS2–luminol were applied in a sandwich-type ECL immunosensor for prostate-specific antigen detection.
Tin dioxide facilitated truncated octahedral Pt3Ni alloy catalyst: synthesis and ultra highly active and durable electrocatalysts for oxygen reduction reaction
Authors: Zhang Na , Du Lei , Du Chunyu , Yin Geping
Published: February 2016

This work firstly synthesized SnO2 modified truncated octahedral Pt3Ni alloy nanoparticle electrocatalyst using neat FPD as the solvent, ORR activity and durability of which is 2.4 times and 2.5 times that of Pt3Ni catalysts.
Characterisation of the impact response of energetic materials: observation of a low-level reaction in 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105)
Authors: Williamson David M. , Gymer Sue , Taylor Nicholas E. , Walley Stephen M. , Jardine Andrew P. , Glauser Annette , French Sara , Wortley Steve
Published: February 2016

Time resolved and integrated diagnostics including high speed photography, mass and optical spectroscopy, and optical-radiometry used to study impact response of high explosives in far more detail than possible with conventional sensitiveness tests.
Reply to the ‘Comment on “A quantitative definition of hypervalency”’ by R. D. Harcourt and T. M. Klapötke, Chem. Sci., 2016, 7, DOI: 10.1039/C5SC04866D
Authors: Durrant Marcus C.
Published: February 2016

The Lewis and quantum mechanical theories of chemical bonding are compared and contrasted, with a view to clarifying the relationship between Harcourt’s ‘increased valence’ quantum approach and the recently proposed quantitative definition of hypervalency.
High performance inverse opal Li-ion battery with paired intercalation and conversion mode electrodes
Authors: McNulty David , Geaney Hugh , Armstrong Eileen , O'Dwyer Colm
Published: February 2016

Inverse opal porous materials have provided several breakthroughs that have facilitated high rate capability, better capacity retention and material stability in Li-ion batteries.
Three dimensional nanocomposite of reduced graphene oxide and hexagonal boron nitride as an efficient metal-free catalyst for oxygen electroreduction
Authors: Patil Indrajit M. , Lokanathan Moorthi , Kakade Bhalchandra
Published: February 2016

Excellent ORR kinetics by an h-BN/rGO nanocomposite is shown with an onset potential ∼0.8 Vvs.RHE, attributed to the segregation mechanism and coalescence of graphitic planes of h-BN and rGO.
Conjugate refractive–reflective homogeniser in a 500× Cassegrain concentrator: design and limits
Authors: Shanks Katie , Baig Hasan , Senthilarasu Sundaram , Reddy K.S. , Mallick Tapas K.
Published: February 2016

In this study, we present the conjugate refractive reflective homogeniser (CRRH) to be used in a 500× Cassegrain photovoltaic concentrator. The CRRH is a dielectric crossed v‐trough lined with a reflective film whilst maintaining an air gap between them. This air gap between the two surfaces helps in trapping the scattered light from the refractive geometry and ensures both total internal reflection and standard reflection of the escaped rays. A 10–42% drop in optical efficiency has been shown to occur due to varying the surface roughness of the homogeniser in these ray trace simulations for the Cassegrain setup. The CRRH increased the overall optical efficiency by a maximum of 7.75% in comparison with that of a standard refractive homogeniser simulated within the same concentrator system. The acceptance angle and flux distribution of these homogenisers was also investigated. The simple shape of the CRRH ensures easy manufacturing and produces a relatively uniform irradiance distribution on the receiver. The theoretical benefit of the CRRH is also validated via practical measurements. Further research is required but a 6.7% power increase was measured under a 1000 W/m2 solar simulator at normal incidence for the experimental test.
Colloidal crystallite suspensions studied by high pressure small angle x-ray scattering
Authors: Schroer M. A. , Westermeier F. , Lehmkühler F. , Conrad H. , Schavkan A. , Zozulya A. V. , Fischer B. , Roseker W. , Sprung M. , Gutt C. , Grübel G.
Published: February 2016

We report on high pressure small angle x-ray scattering on suspensions of colloidal crystallites in water. The crystallites made out of charge-stabilized poly-acrylate particles exhibit a complex pressure dependence which is based on the specific pressure properties of the suspending medium water. The dominant effect is a compression of the crystallites caused by the compression of the water. In addition, we find indications that also the electrostatic properties of the system, i.e. the particle charge and the dissociation of ions, might play a role for the pressure dependence of the samples. The data further suggest that crystallites in a metastable state induced by shear-induced melting can relax to a similar structural state upon the application of pressure and dilution with water. X-ray cross correlation analysis of the two-dimensional scattering patterns indicates a pressure-dependent increase of the orientational order of the crystallites correlated with growth of these in the suspension. This study underlines the potential of pressure as a very relevant parameter to understand colloidal crystallite systems in aqueous suspension.
Single vacancy defect spectroscopy on HfO2 using random telegraph noise signals from scanning tunneling microscopy
Authors: Thamankar R. , Raghavan N. , Molina J. , Puglisi F. M. , O'Shea S. J. , Shubhakar K. , Larcher L. , Pavan P. , Padovani A. , Pey K. L.
Published: February 2016

Random telegraph noise (RTN) measurements are typically carried out at the device level using standard probe station based electrical characterization setup, where the measured current represents a cumulative effect of the simultaneous response of electron capture/emission events at multiple oxygen vacancy defect (trap) sites. To better characterize the individual defects in the high-κ dielectric thin film, we propose and demonstrate here the measurement and analysis of RTN at the nanoscale using a room temperature scanning tunneling microscope setup, with an effective area of interaction of the probe tip that is as small as 10 nm in diameter. Two-level and multi-level RTN signals due to single and multiple defect locations (possibly dispersed in space and energy) are observed on 4 nm HfO2 thin films deposited on n-Si (100) substrate. The RTN signals are statistically analyzed using the Factorial Hidden Markov Model technique to decode the noise contribution of more than one defect (if any) and estimate the statistical parameters of each RTN signal (i.e., amplitude of fluctuation, capture and emission time constants). Observation of RTN at the nanoscale presents a new opportunity for studies on defect chemistry, single-defect kinetics and their stochastics in thin film dielectric materials. This method allows us to characterize the fast traps with time constants ranging in the millisecond to tens of seconds range.
A spectroscopic refractometer based on plasmonic interferometry
Authors: Feng Jing , Pacifici Domenico
Published: February 2016

We describe the design, fabrication, and testing of a spectroscopic refractometer that employs plasmonic interferometry to measure the optical dielectric functions of materials in the visible range. The proposed device, dubbed a plasmonic refractometer, consists of an array of slit-groove plasmonic interferometers etched in a ∼300 nm-thick metal film (silver or gold) with arm lengths varying in steps of 25 nm up to ∼8 μm. The nano-groove in each interferometer is able to generate propagating surface plasmon polaritons efficiently in a broad wavelength range, without requiring prism- or grating-coupling configurations. An integrated microfluidic channel ensures uniform delivery of dielectric materials in liquid phase. Spectrally resolved plasmonic interferograms are generated by measuring light transmission spectra through the slit of each slit-groove plasmonic interferometer and plotting the normalized intensity as a function of arm length (0.26–8.16 μm) and incident wavelength (400–800 nm) for various combinations of metal/dielectric materials. Fits of the plasmonic interferograms with a surface plasmon interference model allow determination of the refractive index dispersion of a broad class of dielectric materials, over a wide range of wavelengths and dielectric constants. As proof of concept, we extract and report the dielectric functions of representative materials, such as silver, gold, water, methanol, and ethanol.
AxBAxB… pulsed atomic layer deposition: Numerical growth model and experiments
Authors: Muneshwar Triratna , Cadien Ken
Published: February 2016

Atomic layer deposition (ALD) is widely used for the fabrication of advanced semiconductor devices and related nanoscale structures. During ALD, large precursor doses (>1000 L per pulse) are often required to achieve surface saturation, of which only a small fraction is utilized in film growth while the rest is pumped from the system. Since the metal precursor constitutes a significant cost of ALD, strategies to enhance precursor utilization are essential for the scaling of ALD processes. In the precursor reaction step, precursor physisorption is restricted by steric hindrance (mA1) from ligands on the precursor molecules. On reaction, some of these ligands are removed as by-products resulting in chemisorbed species with reduced steric hindrance (mA1 → mA2, where mA2 < mA1) and some of the initially hindered surface reaction sites becoming accessible for further precursor physisorption. To utilize these additional reaction sites, we propose a generalized AxBAxB… pulsed deposition where the total precursor dose (ΦA) is introduced as multiple x (x > 1, x ∈ I) short-pulses rather than a single pulse. A numerical first-order surface reaction kinetics growth model is presented and applied to study the effect of AxBAxB… pulsed ALD on the growth per cycle (GPC). The model calculations predict higher GPC for AxBAxB… pulsing than with ABAB… deposition. In agreement with the model predictions, with AxBAxB… pulsed deposition, the GPC was found to increase by ∼46% for ZrN plasma enhanced ALD (PEALD), ∼49% for HfO2 PEALD, and ∼8% for thermal Al2O3 ALD with respect to conventional ABAB… pulsed growth.
Work function bowing in Si1−xGex heterostructures: Ab initio results
Authors: Amato Michele , Bertocchi Matteo , Ossicini Stefano
Published: February 2016

A systematic theoretical study of the work function behavior for Si1−xGex heterostructures over the whole composition range, from Si (x = 0) to Ge (x = 1), is presented. Our results, obtained through Density Functional Theory calculations and in good agreement with experimental evidences, show that increasing the Ge content lowers the work function value. We find that in order to exactly reproduce this behaviour in relation to the work function of pure Ge and Si systems and their concentrations, a deviation from the linear Vegard's rule is necessary. However, the calculated bowing parameter is very small, thus making the simple linear interpolation a valid approximation to obtain the work function of complex SiGe alloys.
Theoretical analysis of non-radiative multiphonon recombination activity of intrinsic defects in CdTe
Authors: Krasikov D. N. , Scherbinin A. V. , Knizhnik A. A. , Vasiliev A. N. , Potapkin B. V. , Sommerer T. J.
Published: February 2016

We present an analysis of recombination activity of intrinsic defects (VCd, TeCd, VTe, and Tei) in CdTe based on the multiphonon single-mode carrier-capture model, with vibronic parameters obtained using hybrid density functional theory. This analysis allows us to determine the defects and the corresponding electronic processes that have high trapping rates for electrons, for holes, or for both. The latter, being potentially the most active recombination centers, decreases the carrier lifetime in the absorber layer of a CdTe solar cell. Taking into account the relatively high calculated capture cross-sections of the TeCd antisite defect (σ = 8.7× 10−15 cm2 for electron capture on TeCd+2 defect, σ = 6.8 × 10−14 cm2 for hole capture on TeCd+1 defect at room temperature) and its deep trapping level (0.41 eV for +2/+1 level), we conclude that this defect is the most active recombination center among the intrinsic defects in p-type CdTe. Other processes that do not lead to effective recombination are: (i) fast hole capture on Tei+1 defect (σ = 1.1 × 10−13 cm−2), (ii) electron capture on TeCd+1 defect (σ = 2.9 × 10−15 cm−2), (iii) somewhat slower hole capture on TeCd0 defect (σ = 9.4 × 10−20 cm−2), (iv) hole capture on VCd−1 defect (σ = 7 × 10−19 cm2), and (v) electron capture on Tei+1 defect (σ = 4.4 × 10−19 cm−2). The cross-sections are found to be negligibly small for the remaining capture processes.
Physicochemical properties and hygroscopicity of tobacco stem biochar pyrolyzed at different temperatures
Authors: Chen Hanping , Lin Guiying , Wang Xianhua , Chen Yingquan , Liu Yingpeng , Yang Haiping , Shao Jingai
Published: February 2016

The physicochemical properties and hygroscopicity of biochar derived from tobacco stem pyrolysis were investigated to get the effect of pyrolysis temperature (250–950 °C). The chemical composition and structure of biochar were characterized with proximate and ultimate analysis, X-ray fluorescence, and two-dimensional perturbation-based correlation infrared spectroscopy (2D-PCIS) based on Fourier-transform infrared spectroscopy. The physical pore structure was analyzed by Brunauer-Emmett-Teller surface area. Results showed that surface area and pore volumes of biochar increased, while biochar yield, volatile matter, H/C and O/C ratios decreased with the increasing pyrolysis temperature. The 2D-PCIS analysis suggested that the intensity of hydroxyl groups and aromatic skeletal changed greatly with pyrolysis temperature. Tobacco stem biochar was abundant in Ca and K and contained P, Mg, S, and Cl, while N was low and decreased with temperature. Tobacco stem biochar produced at 550 °C has the lowest hygroscopicity under 50%–70% humidity. Biochar produced from tobacco stem may not be suitable to be used as fuel while it can be developed for soil amendment and adsorbent by optimizing pyrolysis conditions and modifications.
Modelling the performance of rooftop photovoltaic systems under urban Mediterranean outdoor conditions
Authors: Polo J. , Alonso-García M. C. , Silva J. P. , Alonso-Abella M.
Published: February 2016

Evaluation and validation of photovoltaics performance models for different technologies and climate regions is of high interest for photovoltaic (PV) systems deployment. There are many tools for modelling the performance of PV arrays; some of them are free or open source. This work presents the results of modelling five different rooftop PV arrays in the range of 1 kW using the Sandia Array Performance Model during one complete year in Madrid. The evaluation of the Sandia model has shown a rather good performance in general, even though several empirical parameters in the input were unknown and were taken from other similar modules in the Sandia database. Particularly, high accuracy has been found in modelling the p-Si array with −0.07% of relative error in the annual energy output. Larger errors were found in the case of a-Si and m-Si (back contact) arrays.