bluuebunny/crossref_metadata_2025 huggingface dataset:
Laser-flash-photolysis-spectroscopy: a nondestructive method?
Authors: Schneider Jenny , Nikitin Konstantin , Dillert Ralf , Bahnemann Detlef W.
Published: October 2016

Herein, we report the effect of the laser illumination during the diffuse-reflectance laser-flash-photolysis measurements on the morphological and optical properties of TiO2 powders. A grey-blue coloration of the TiO2 nanoparticles has been observed after intense laser illumination. This is explained by the formation of nonreactive trapped electrons accompanied by the release of oxygen atoms from the TiO2 matrix as detected by means of UV-vis and EPR spectroscopy. Moreover, in the case of the pure anatase sample a phase transition of some TiO2 nanoparticles located in the inner region from anatase to rutile occurred. It is suggested that these structural changes in TiO2 are caused by an energy and charge transfer to the TiO2 lattice.
Liquid/liquid extraction of biomass-derived lignin from lignocellulosic pretreatments
Authors: Stiefel Serafin , Di Marino Davide , Eggert Armin , Kühnrich Ivo Robert , Schmidt Markus , Grande Philipp M. , Leitner Walter , Jupke Andreas , Wessling Matthias
Published: October 2016

The extraction of lignin from lignocellulosic pretreatments regards the transfer of lignin from the fractionation solvent to a different medium for valorization.
Measure and control: molecular management is a key to the Sustainocene!
Authors: MacFarlane Douglas R. , Zhang Xinyi , Kar Mega
Published: October 2016

Editorial on monitoring the production of toxic, or environmentally problematic substances in real time and controlling their occurrence.
Recent advances in X-ray compatible microfluidics for applications in soft materials and life sciences
Authors: Ghazal Aghiad , Lafleur Josiane P. , Mortensen Kell , Kutter Jörg P. , Arleth Lise , Jensen Grethe V.
Published: October 2016

The increasingly narrow and brilliant beams at X-ray facilities reduce requirements for sample volume and data acquisition time, but correspondingly increase the requirements for fast, reproducible sample handling and processing. Here, X-ray compatible microfluidics for applications in soft materials and life science is reviewed.
Programmable assembly of heterogeneous microparts by an untethered mobile capillary microgripper
Authors: Giltinan Joshua , Diller Eric , Sitti Metin
Published: October 2016

At the sub-millimeter scale, capillary forces enable robust and reversible adhesion between biological materials and varied substrates.
Integrated machine learning, molecular docking and 3D-QSAR based approach for identification of potential inhibitors of trypanosomal N-myristoyltransferase
Authors: Singh Nidhi , Shah Priyanka , Dwivedi Hemlata , Mishra Shikha , Tripathi Renu , Sahasrabuddhe Amogh A. , Siddiqi Mohammad Imran
Published: October 2016

Integratedin silicoapproaches for the identification of antitrypanosomal inhibitors.
Effect of D168V mutation in NS3/4A HCV protease on susceptibilities of faldaprevir and danoprevir
Authors: Meeprasert Arthitaya , Hannongbua Supot , Kungwan Nawee , Rungrotmongkol Thanyada
Published: October 2016

Disrupted hydrogen bonding network in the extended S2 subsite lead to faldaprevir and danoprevir resistances.
Correction: BiKEGG: a COBRA toolbox extension for bridging the BiGG and KEGG databases
Authors: Jamialahmadi Oveis , Motamedian Ehsan , Hashemi-Najafabadi Sameereh
Published: October 2016

Correction for ‘BiKEGG: a COBRA toolbox extension for bridging the BiGG and KEGG databases’ by Oveis Jamialahmadi et al., Mol. BioSyst., 2016, DOI: 10.1039/c6mb00532b.
Photophysical comparisons of PEGylated porphyrins, chlorins and bacteriochlorins in water
Authors: Mandal Amit Kumar , Sahin Tuba , Liu Mengran , Lindsey Jonathan S. , Bocian David F. , Holten Dewey
Published: October 2016

Synthesis of a bioconjugatable water-soluble (PEGylated) trans-AB-porphyrin enables photophysical comparisons (τS, kf, kic, kisc, Φf, Φic, Φisc) with analogous chlorins and bacteriochlorins in DMF and water.
Cu(ii) complex of a new isoindole derivative: structure, catecholase like activity, antimicrobial properties and bio-molecular interactions
Authors: Adhikari Sangita , Lohar Sisir , Kumari Babli , Banerjee Aparna , Bandopadhyay Rajib , Matalobos Jesús Sanmartín , Das Debasis
Published: October 2016

An isoindole based trigonal bipyramidal Cu(ii) complex shows catecholase and antimicrobial activities. It interacts with bio-relevant antipyrine derivative.
BMIm HCO3: an ionic liquid with carboxylating properties. Synthesis of carbamate esters from amines
Authors: Di Nicola A. , Arcadi A. , Rossi L.
Published: October 2016

BMIm HCO3is an ionic liquid obtained by the ion-exchange method showing interesting carboxylating properties.
Remarkable acceleration of template-directed photodimerisation of 9-phenylethynylanthracene derivatives assisted by complementary salt bridge formation
Authors: Tanabe Junki , Taura Daisuke , Ousaka Naoki , Yashima Eiji
Published: October 2016

The photodimerisation of 9-phenylethynylanthracene-bound carboxylic acid monomers was remarkably accelerated in the presence of the complementary amidine dimer template.
Complexation between a triptycene-derived oxacalixarene and π-extended viologens: linker-length-dependent orientation of the macrocycles in pseudo[3]rotaxanes
Authors: Wang Han-Xiao , Hu Shu-Zhen , Shi Qiang , Chen Chuan-Feng
Published: October 2016

Unprecedented pseudo[3]rotaxanes based on oxacalixarenes have been formed, and their orientational configurations depended on the linker lengths of the guests.
Visible-light-promoted synthesis of phenanthridines via an intermolecular isocyanide insertion reaction
Authors: Zhou Hui , Deng Xin Zhao , Zhang Ai Hua , Tan Ren Xiang
Published: October 2016

An isocyanide insertion reaction promoted by the combination of an amide and a photoredox is now presented.
Trityl-based alkoxyamines as NMP controllers and spin-labels
Authors: Audran Gérard , Bagryanskaya Elena G. , Brémond Paul , Edeleva Mariya V. , Marque Sylvain R. A. , Parkhomenko Dmitriy A. , Rogozhnikova Olga Yu. , Tormyshev Victor M. , Tretyakov Evgeny V. , Trukhin Dmitry V. , Zhivetyeva Svetlana I.
Published: October 2016

The first report on Spin Labeled NMP (SL-NMP) is highlighted by the preparation of PS-end labelled trityl radicalviaNMP.
A remarkable impact of a minor structural variation in the chain-end on the hierarchical self-assembly of a polymeric foldamer
Authors: Mondal Tathagata , Ghosh Suhrit
Published: October 2016

This article elucidates a remarkable end group effect on the macroscopic assembly pathway of chain folded polyurethanes (PU) PU-2 and PU-3, both of which contain a linear PU chain appended with n-type semiconducting naphthalene-diimide (NDI) chromophores.
Ureido cytosine and cytosine-containing acrylic copolymers
Authors: Zhang Keren , Chen Mingtao , Drummey Kevin J. , Talley Samantha J. , Anderson Lindsey J. , Moore Robert B. , Long Timothy E.
Published: October 2016

Ureido-cytosine pendant groups contributed to random acrylic copolymers with enhanced thermomechanical performance, well-defined morphologies, and reduced water uptake.
Click reactive microgels as a strategy towards chemically injectable hydrogels
Authors: Absil Rémi , Çakir Seda , Gabriele Sylvain , Dubois Philippe , Barner-Kowollik Christopher , Du Prez Filip , Mespouille Laetitia
Published: October 2016

Doubly crosslinked microgels (DX microgels) are hydrogels constructed by covalently interlinked microgel particles, offering two levels of hierarchy within the network, the first one being the microgel and the second being the interlinked microgel network.
Harnessing uranyl oxo atoms via halogen bonding interactions in molecular uranyl materials featuring 2,5-diiodobenzoic acid and N-donor capping ligands
Authors: Carter Korey P. , Kalaj Mark , Cahill Christopher L.
Published: October 2016

The supramolecular assembly of molecular uranyl species via halogen-oxo interactions and spectroscopic manifestations thereof are probed in the solid state.
Differential in vitro and in vivo anti-angiogenic activities of acetal and ketal andrographolide derivatives in HUVEC and zebrafish models
Authors: Sheng Dekuan , Li Jingjing , Wang Kun , Peng Yuran , Li Shang , Sun Yicheng , Liu Zhuyun , Wang Decai , Lee Simon Ming Yuen , Zhou Guo-Chun
Published: October 2016

Acetal and ketal andrographolide derivatives presented differing anti-angiogenic activities when applied toin vitroandin vivomodels, leading to different inhibitory outcomes.
Switchable Cu2O/WOx p–n junction for high density crossbar arrays
Authors: Duan W. J. , Wang J. B. , Zhong X. L. , Song H. J. , Li B.
Published: October 2016

Switchable p–n junction used for crossbar arrays.
Digital microfluidic programmable stencil (dMPS) for protein and cell patterning
Authors: Gao Yibo , Tian Jingxuan , Wu Jinbo , Cao Wenbin , Zhou Bingpu , Shen Rong , Wen Weijia
Published: October 2016

Patterning biomolecules and cells on substrates is usually a prerequisite for biological analysis and cell studies.
Formation mechanism of dysprosium-doped manganese carbonate nanoparticles by thermal decomposition
Authors: Shi Xin , Liu Kang , Wang Tingjian , Zheng Shunjia , Gu Wei , Ye Ling
Published: October 2016

The formation mechanism of Dy-doped MnCO3 NPs through the thermal decomposition method was elucidated and the potential of Dy-doped MnCO3 NPs as an efficient MR contrast agent was demonstrated in the brain glioma-bearing mice.
MgO-templated mesoporous carbons using a pitch-based thermosetting carbon precursor
Authors: Wang Xiu-fang , Chen Ming-ming , Matsumura Kazuki , Toyoda Masahiro , Wang Cheng-yang
Published: October 2016

MgO-templated mesoporous carbons from pitch-based thermosetting amphiphilic carbonaceous material possess yields of 17% and outstanding electrochemical performances.
Biomimetic thermoplastic polyurethane porous membrane with hierarchical structure accelerates wound healing by enhancing granulation tissue formation and angiogenesis
Authors: Lei Qiang , Li Zhichao , Xu Rui , Wang Yuzhen , Li Haisheng , Wang Ying , Liu Menglong , Yang Sisi , Zhan Rixing , Zhao Jian , Liu Bo , Hu Xiaohong , Zhang Xiaorong , He Weifeng , Wu Jun , Xia Hesheng , Luo Gaoxing
Published: October 2016

Wound dressing with hierarchical structure enhances wound healing.
Controlled synthesis of porous Co3O4 nanofibers by spiral electrospinning and their application for formaldehyde oxidation
Authors: Wu Yuxiao , Ma Ming , Zhang Bing , Gao Yunhua , Lu Weipeng , Guo Yanchuan
Published: October 2016

Porous cobaltosic oxide (Co3O4) nanofiber mats were mass-produced by spiral electrospinning and controlled calcination, after which the three-dimensional scaffold still existed and consisted of well-twisted continuous nanofibers.
N-Doped hierarchical porous carbon prepared by simultaneous-activation of KOH and NH3 for high performance supercapacitors
Authors: Guo Nannan , Li Min , Wang Yong , Sun Xingkai , Wang Feng , Yang Ru
Published: October 2016

Hemp stem simultaneously-activated by KOH and NH3 for high performance supercapacitors.
Expanding molecular logic capabilities in DNA-scaffolded multiFRET triads
Authors: Buckhout-White Susan , Brown III Carl W. , Hastman David A. , Ancona Mario G. , Melinger Joseph S. , Goldman Ellen R. , Medintz Igor L.
Published: October 2016

Dynamic rearrangement of DNA nanostructures provides a straightforward yet powerful mechanism for sequence-specific sensing and potential signaling of such interactions.
Two-dimensional dysprosium-modified bamboo-slip-like lithium titanate with high-rate capability and long cycle life for lithium-ion batteries
Authors: Cai Yanjun , Huang Yudai , Jia Wei , Zhang Yue , Wang Xingchao , Guo Yong , Jia Dianzeng , Pang Weikong , Guo Zaiping , Wang Lishi
Published: October 2016

Two-dimensional dysprosium-modified bamboo-slip-like Li4Ti5O12have been synthesized by one-pot hydrothermal method. The samples exhibit superior high-rate capability, and excellent cycle performance.
Wide bandgap copolymers with vertical benzodithiophene dicarboxylate for high-performance polymer solar cells with an efficiency up to 7.49%
Authors: Tao Qiang , Liu Tao , Duan Linrui , Cai Yufeng , Xiong Wenjing , Wang Pu , Tan Hua , Lei Gangtie , Pei Yong , Zhu Weiguo , Yang Renqiang , Sun Yanming
Published: October 2016

A novel vertical carboxylate functionalized benzodithiophene unit was designed as an election-accepting block to build D–A type copolymers, and a high Voc of 1.03 V and a significant PCE of 7.49% were achieved.
Mixed co-solvent engineering of PEDOT:PSS to enhance its conductivity and hybrid solar cell properties
Authors: Thomas Joseph Palathinkal , Leung Kam Tong
Published: October 2016

Addition of mixed co-solvents of ethylene glycol and methanol in PEDOT:PSS changes its microstructure, and produces high conductivity and hybrid solar cell efficiency exceeding 14.6% on planar Si substrates.
Regulation of local bone remodeling mediated by hybrid multilayer coating embedded with hyaluronan-alendronate/BMP-2 nanoparticles on Ti6Al7Nb implants
Authors: Shen Xinkun , Zhang Yarong , Hu Yan , Luo Zhong , Ma Pingping , Li Liqi , Mu Caiyun , Huang Ling , Pei Yuxia , Cai Kaiyong
Published: October 2016

Hyaluronate-alendronate/BMP-2 nanoparticles were inserted into Gel/Chi multilayers on Ti6Al7Nb for enhancing BMP-2 stability and promoting local osteogenesis under osteoporosis.
Initiator-free crosslinking of oxetane functionalized low bandgap polymers: an approach towards stabilized bulk heterojunction solar cells
Authors: Knauer Philipp , Hahn Tobias , Köhler Anna , Strohriegl Peter
Published: October 2016

We report the synthesis of crosslinkable derivatives of the low bandgap polymer PFDTBT, poly(2,7-(9,9-dialkylfluorene)-alt-(5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole))), and the stabilization of BHJ solar cells by initiator-free crosslinking of oxetanes.
Design of photoactive hybrid based intelligent photodetectors for identifying the detected wavelength
Authors: Jia Feixiang , Huang Fan , Ouyang Sheng , Cai Caoyuan , Xu Zhihao , Wu Congjun , Ma Yang , Wang Min
Published: October 2016

The similar response time for UV and visible light of the graphene/CdS photodetector is intentionally tuned by inserting ZnS films to produce the graphene/ZnS/CdS photodetector, which can be used as a characteristic parameter to distinguish the detected UV and visible light.
A particle-free silver precursor ink useful for inkjet printing to fabricate highly conductive patterns
Authors: Chen Jin-ju , Zhang Jing , Wang Yan , Guo Yan-long , Feng Zhe-sheng
Published: October 2016

A particle-free silver precursor ink inkjet-printed as an activator for electroless plating was developed to fabricate highly conductive patterns.
Understanding the superior thermoelectric performance of Sb precipitated Ge17Sb2Te20
Authors: Williams Jared B. , Morelli Donald T.
Published: October 2016

The following work has found that by incorporating secondary phases of Sb into the Ge17Sb2Te20 matrix ZT values in excess of 2 are found.
The C-terminal dimerization motif of cyclase-associated protein is essential for actin monomer regulation
Authors: Iwase Shohei , Ono Shoichiro
Published: October 2016

Cyclase-associated protein (CAP) is a conserved actin-regulatory protein that functions together with actin depolymerizing factor (ADF)/cofilin to enhance actin filament dynamics. CAP has multiple functional domains, and the function to regulate actin monomers is carried out by its C-terminal half containing a Wiskott–Aldrich Syndrome protein homology 2 (WH2) domain, a CAP and X-linked retinitis pigmentosa 2 (CARP) domain, and a dimerization motif. WH2 and CARP are implicated in binding to actin monomers and important for enhancing filament turnover. However, the role of the dimerization motif is unknown. Here, we investigated the function of the dimerization motif of CAS-2, a CAP isoform in the nematode Caenorhabditis elegans, in actin monomer regulation. CAS-2 promotes ATP-dependent recycling of ADF/cofilin-bound actin monomers for polymerization by enhancing exchange of actin-bound nucleotides. The C-terminal half of CAS-2 (CAS-2C) has nearly as strong activity as full-length CAS-2. Maltose-binding protein (MBP)-tagged CAS-2C is a dimer. However, MBP-CAS-2C with a truncation of either one or two C-terminal β-strands is monomeric. Truncations of the dimerization motif in MBP-CAS-2C nearly completely abolish its activity to sequester actin monomers from polymerization and enhance nucleotide exchange on actin monomers. As a result, these CAS-2C variants, also in the context of full-length CAS-2, fail to compete with ADF/cofilin to release actin monomers for polymerization. CAS-2C variants lacking the dimerization motif exhibit enhanced binding to actin filaments, which is mediated by WH2. Taken together, these results suggest that the evolutionarily conserved dimerization motif of CAP is essential for its C-terminal region to exert the actin monomer-specific regulatory function.
Real-time imaging of intracellular hydrogen peroxide in pancreatic islets
Authors: Neal Adam , Rountree Austin , Kernan Kelly , Van Yserloo Brian , Zhang Huiliang , Reed Benjamin J. , Osborne William , Wang Wang , Sweet Ian R.
Published: October 2016

A real-time method to measure intracellular hydrogen peroxide (H2O2) would be very impactful in characterizing rapid changes that occur in physiologic and pathophysiologic states. Current methods do not provide the sensitivity, specificity and spatiotemporal resolution needed for such experiments on intact cells. We developed the use of HyPer, a genetic indicator for H2O2 that can be expressed in the cytosol (cyto-HyPer) or the mitochondria (mito-HyPer) of live cells. INS-1 cells or islets were permeabilized and the cytosolic HyPer signal was a linear function of extracellular H2O2, allowing fluorescent cyto-HyPer signals to be converted into H2O2 concentrations. Glucose increased cytosolic H2O2, an effect that was suppressed by overexpression of catalase. Large perturbations in pH can influence the HyPer signal, but inclusion of HEPES [4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid] in the perfusate prevented pH changes, but did not affect glucose-induced cyto-HyPer signals, suggesting that this effect is largely pH-independent. Using the assay, two fundamental questions were addressed. Knockdown of superoxide dismutase 2 (SOD2), the mitochondrial form of SOD, completely suppressed glucose-induced H2O2. Furthermore, glucose also induced mitochondrial superoxide and H2O2 production, which preceded the appearance of cytosolic H2O2. Therefore, glucose-induced H2O2 largely originated from mitochondria. Finally, the glucose-induced HyPer signal was less than 1/20th of that induced by toxic levels of H2O2. Overall, the use of HyPer for real-time imaging allowed resolution of acute changes in intracellular levels of H2O2 and will have great utility for islet studies involving mechanisms of H2O2-mediated signaling and oxidative stress.
The structure, kinetics and interactions of the β-carboxysomal β-carbonic anhydrase, CcaA
Authors: McGurn Leah D. , Moazami-Goudarzi Maryam , White Sean A. , Suwal Tannu , Brar Beant , Tang Jason Q. , Espie George S. , Kimber Matthew S.
Published: October 2016

CcaA is a β-carbonic anhydrase (CA) that is a component of the carboxysomes of a subset of β-cyanobacteria. This protein, which has a characteristic C-terminal extension of unknown function, is recruited to the carboxysome via interactions with CcmM, which is itself a γ-CA homolog with enzymatic activity in many, but not all cyanobacteria. We have determined the structure of CcaA from Synechocystis sp. PCC 6803 at 1.45 Å. In contrast with the dimer-of-dimers organization of most bacterial β-CAs, or the loose dimer-of-dimers-of-dimers organization found in the plant enzymes, CcaA shows a well-packed trimer-of-dimers organization. The proximal part of the characteristic C-terminal extension is ordered by binding at a site that passes through the two-fold symmetry axis shared with an adjacent dimer; as a result, only one of a pair of converging termini can be ordered at any given time. Docking in Rosetta failed to find well-packed solutions, indicating that formation of the CcaA/CcmM complex probably requires significant backbone movements in at least one of the binding partners. Surface plasmon resonance experiments showed that CcaA forms a complex with CcmM with sub-picomolar affinity, with contributions from residues in CcmM's αA helix and CcaA's C-terminal tail. Catalytic characterization showed CcaA to be among the least active β-CAs characterized to date, with activity comparable with the γ-CA, CcmM, it either complements or replaces. Intriguingly, the C-terminal tail appears to partly inhibit activity, possibly indicating a role in minimizing the activity of unencapsulated enzyme.
Comprehension of Inferences in a Narrative in 3- to 6-Year-Old Children
Authors: Filiatrault-Veilleux Paméla , Bouchard Caroline , Trudeau Natacha , Desmarais Chantal
Published: October 2016

Purpose

This study aimed to describe the development of inferential abilities of children age 3 to 6 years in a narrative using a dialogic reading task on an iPad.

Method

Participants were 121 typically developing children, divided into 3 groups according to age range (3–4 years old, 4–5 years old, 5–6 years old). Total score of inferential comprehension, subscores by causal inference type targeting elements of the story grammar, and quality of response were examined across groups.

Results

Inferential comprehension emerged early, from 3 to 4 years old, with considerable interindividual variability. Inferential comprehension scores increased significantly in relation to age, leading to developmental steps with regards to the type of causal inferences. The ability to infer the problem of the story, the internal response of a character, and predictions were easier starting at age 4 years. Then, the 5- to 6-year-olds were better able to infer the goal, the attempt to solve the problem, and the resolution. Last, between the ages of 3 and 6 years, children improved in terms of the quality of response they provided.

Conclusion

This study addresses important gaps in our knowledge of inferential comprehension in young children and has implications for planning of early education in this realm.
Interrelationships Between Working Memory, Processing Speed, and Language Development in the Age Range 2–4 years
Authors: Newbury Jayne , Klee Thomas , Stokes Stephanie F. , Moran Catherine
Published: October 2016

Purpose

This study explored associations between working memory and language in children aged 2–4 years.

Method

Seventy-seven children aged 24–30 months were assessed on tests measuring language, visual cognition, verbal working memory (VWM), phonological short-term memory (PSTM), and processing speed. A standardized test of receptive and expressive language was used as the outcomes measure 18 months later.

Results

There were moderate-to-strong longitudinal bivariate relationships between the 3 processing measures and language outcomes. Early VWM showed the strongest bivariate relationship with both later expressive (
r
= .71) and receptive language (
r
= .72). In a hierarchical multiple regression analysis, adding early VWM, PSTM, and processing speed improved prediction of receptive and expressive language outcomes (12%–13% additional variance) compared with models consisting only of early receptive or expressive language, parent education, and age.

Conclusions

Unique associations in hierarchical regression analyses were demonstrated between VWM at age two years and receptive and expressive language skills at age four, and between early processing speed and later receptive language. However, early PSTM did not predict unique variance in language outcomes, as it shared variance with other measures.
Effects of Physical Activity and Ginkgo Biloba on Cognitive Function and Oxidative Stress Modulation in Ischemic Rats
Authors: Bafandeh Gharamaleki Hassan , Vaghef Ladan
Published: October 2016

Either exercise or Ginkgo biloba is reported to improve cognitive functioning. The aim of this study is to compare the protective effects of forced exercise and Ginkgo biloba on oxidative stress as well as memory impairments induced by transient cerebral ischemia. Adult male Wistar rats were treated with treadmill running or Ginkgo biloba extract for 2 weeks before cerebral ischemia. Memory was assessed using a Morris water maze (MWM) task. At the end of the behavioral testing, oxidative stress biomarkers were evaluated in the hippocampus tissue. As expected, the cerebral ischemia induced memory impairment in the MWM task, and oxidative stress in the hippocampus. These effects were significantly prevented by treadmill running. Indeed, it ameliorated oxidative stress and memory deficits induced by ischemia. In contrast, Ginkgo biloba was not as effective as exercise in preventing ischemia-induced memory impairments. The results confirmed the neuroprotective effects of treadmill running on hippocampus-dependent memory.
Hydrocracking of bio-alkanes over Pt/Al-MCM-41 mesoporous molecular sieves for bio-jet fuel production
Authors: Lu Meizhen , Liu Xuejun , Li Yongqiang , Nie Yong , Lu Xianghong , Deng Dongshun , Xie Qinglong , Ji Jianbing
Published: October 2016

Bi-functional catalysts consisting of platinum on aluminosilicate MCM-41 materials with Si/Al ratios between 10 and 30 were prepared via direct mixed-gel synthesis. The catalysts were tested in the hydrocracking of bio-alkanes, produced from biodiesel hydrodeoxygenation and composed of n-hexadecane and n-octadecane, for the production of bio-jet fuel. The effects of temperature, pressure, weight hourly space velocity (WHSV), and H2/n-paraffin weight ratio on bio-alkanes conversion and product distribution were examined. The conversion was found to be dependent on the acid strength of the catalyst supports which were proportional to the Al content. However, the catalyst selectivity decreased with the increasing Al content. The optimal Si/Al ratio, temperature, pressure, WHSV, and H2/n-paraffin weight ratio were determined to be 20, 330 °C, 2 MPa, 1 h−1, and 0.20, respectively. Under these conditions, the bio-alkanes conversion and kerosene/gasoline ratio in the product reached 65.62% and 1.96, respectively.
Polymeric cantilever integrated with PDMS/graphene composite strain sensor
Authors: Choi Young-Soo , Gwak Min-Joo , Lee Dong-Weon
Published: October 2016

This paper describes the mechanical and electrical characteristics of a polydimethylsiloxane (PDMS) cantilever integrated with a high-sensitivity strain sensor. The strain sensor is fabricated using PDMS and graphene flakes that are uniformly distributed in the PDMS. In order to prepare PDMS/graphene composite with uniform resistance, a tetrahydrofuran solution is used to decrease the viscosity of a PDMS base polymer solution. A horn-type sonicator is then used to mix the base polymer with graphene flakes. Low viscosity of the base polymer solution improves the reliability and reproducibility of the PDMS/graphene composite for strain sensor applications. After dicing the composite into the desired sensor shape, a tensile test is performed. The experimental results show that the composite with a concentration of 30 wt.% exhibits a linear response up to a strain rate of 9%. The graphene concentration of the prepared materials affects the gauge factor, which at 20% graphene concentration reaches about 50, and with increasing graphene concentration to 30% decreases to 9. Furthermore, photolithography, PDMS casting, and a stencil process are used to fabricate a PDMS cantilever with an integrated strain sensor. The change in resistance of the integrated PDMS/graphene sensor is characterized with respect to the displacement of the cantilever of within 500 μm. The experimental results confirmed that the prepared PDMS/graphene based sensor has the potential for high-sensitive biosensor applications.
The impact of heating the breakdown bubble on the global mode of a swirling jet: Experiments and linear stability analysis
Authors: Rukes Lothar , Sieber Moritz , Paschereit C. Oliver , Oberleithner Kilian
Published: October 2016

This study investigates the dynamics of non-isothermal swirling jets undergoing vortex breakdown, with an emphasis on helical coherent structures. It is proposed that the dominant helical coherent structure can be suppressed by heating the recirculation bubble. This proposition is assessed with stereo Particle Image Velocimetry (PIV) measurements of the breakdown region of isothermal and heated swirling jets. The coherent kinetic energy of the dominant helical structure was derived from PIV snapshots via proper orthogonal decomposition. For one set of experimental parameters, mild heating is found to increase the energy content of the dominant helical mode. Strong heating leads to a reduction by 30% of the coherent structures energy. For a second set of experimental parameters, no alteration of the dominant coherent structure is detectable. Local linear stability analysis of the time-averaged velocity fields shows that the key difference between the two configurations is the density ratio at the respective wavemaker location. A density ratio of approximately 0.8 is found to correlate to a suppression of the global mode in the experiments. A parametric study with model density and velocity profiles indicates the most important parameters that govern the local absolute growth rate: the density ratio and the relative position of the density profiles and the inner shear layer.
Comment on “Gauge-invariant expectation values of the energy of a molecule in an electromagnetic field” [J. Chem. Phys. 144, 044109 (2016)]
Authors: Woolley R. Guy
Published: October 2016

The ‘problem’ identified in the paper [J. Chem.Phys. 144, 044109 (2016)] does not arise in a properly formulated non-relativistic Hamiltonian formalism for both classical and quantum electrodynamics.
Improved electrothermal performance of custom-shaped micro heater based on anisotropic laser-reduced graphene oxide
Authors: Zhang Tian-Yu , Zhao Hai-Ming , Yang Zhen , Wang Qian , Wang Dan-Yang , Deng Ning-Qin , Yang Yi , Ren Tian-Ling
Published: October 2016

In this paper, a flexible heater based on anisotropic laser-reduced graphene oxide (LRGO) is established. Attributing to precision and shape design of laser processing and excellent adhesion of graphene oxide, the LRGO-based heater can be microminiaturized with custom patterns and integrated on various substrates, which is what the existing film heaters cannot do and can be widely used for wearable heating devices, flexural warming systems in medical science, and light deicing equipment and heaters for aero vehicles. The electrothermal performance of the anisotropic LRGO is investigated systematically through a series of experiments including Raman spectra, SEM, white-light interferograms, IV testing, and infrared thermography. The electrothermal performance of the LRGO with the parallel aligned direction is better than the LRGO with the vertical aligned direction. The electrothermal performance can be improved greatly through radiating repeatedly. The saturated temperature and heating rate of the LRGO radiated twice are almost double that of the LRGO radiated once. Radiating thrice damages the material and structure, reducing electrothermal performance.
Using an expanding nondirect product harmonic basis with an iterative eigensolver to compute vibrational energy levels with as many as seven atoms
Authors: Brown James , Carrington Tucker
Published: October 2016

We demonstrate that it is possible to use a variational method to compute 50 vibrational levels of ethylene oxide (a seven-atom molecule) with convergence errors less than 0.01 cm−1. This is done by beginning with a small basis and expanding it to include product basis functions that are deemed to be important. For ethylene oxide a basis with fewer than 3 × 106 functions is large enough. Because the resulting basis has no exploitable structure we use a mapping to evaluate the matrix-vector products required to use an iterative eigensolver. The expanded basis is compared to bases obtained from pre-determined pruning condition. Similar calculations are presented for molecules with 3, 4, 5, and 6 atoms. For the 6-atom molecule, CH3CH, the required expanded basis has about 106 000 functions and is about an order of magnitude smaller than bases made with a pre-determined pruning condition.
Multichannel emission spectrometer for high dynamic range optical pyrometry of shock-driven materials
Authors: Bassett Will P. , Dlott Dana D.
Published: October 2016

An emission spectrometer (450-850 nm) using a high-throughput, high numerical aperture (N.A. = 0.3) prism spectrograph with stepped fiberoptic coupling, 32 fast photomultipliers and thirty-two 1.25 GHz digitizers is described. The spectrometer can capture single-shot events with a high dynamic range in amplitude and time (nanoseconds to milliseconds or longer). Methods to calibrate the spectrometer and verify its performance and accuracy are described. When a reference thermal source is used for calibration, the spectrometer can function as a fast optical pyrometer. Applications of the spectrometer are illustrated by using it to capture single-shot emission transients from energetic materials or reactive materials initiated by km⋅s−1 impacts with laser-driven flyer plates. A log (time) data analysis method is used to visualize multiple kinetic processes resulting from impact initiation of HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) or a Zr/CuO nanolaminate thermite. Using a gray body algorithm to interpret the spectral radiance from shocked HMX, a time history of temperature and emissivity was obtained, which could be used to investigate HMX hot spot dynamics. Finally, two examples are presented showing how the spectrometer can avoid temperature determination errors in systems where thermal emission is accompanied by atomic or molecular emission lines.
Impacts of annealing temperature on charge trapping performance in Zr0.5Hf0.5O2 for nonvolatile memory
Authors: Zhao J. H. , Yan X. B. , Li Y. C. , Yang T. , Jia X. L. , Zhou Z. Y. , Zhang Y. Y.
Published: October 2016

In this study, Zr0.5Hf0.5O2 films were fabricated on Si substrate and were annealed at different temperatures by rapid thermal annealing (RTA) process. The charge trapping memory devices based on Zr0.5Hf0.5O2/SiO2/Si simple structure were investigated in detail. The memory device annealing at 690 °C shows the best property with a memory window of 5.6 V under ±12 V sweeping voltages in its capacitance-voltage curve and a better retention property. The high resolved transmission electron microscopy shows the generated SiO2 working as tunneling layer after RTA process, whose thickness increases with the rise of temperature. Combined with the TEM results, the photoluminescence spectrum and in situ angle resolved photoemission spectroscopy results further verify that oxygen vacancies and inter-diffusion layer also play a crucial role in charge trapping performance. This work provides direct insights for the charge trapping mechanisms based on high-k Zr0.5Hf0.5O2 films devices.
Modification of electronic band structure in mL + nL (m = 1, 2; n = 1–5) free-stacking graphene
Authors: Ji Jianting , He Rui , Jie Yinghao , Zhang Anmin , Ma Xiaoli , Pan Linjing , Wang Le , Zhang Liyuan , Zhang Qing-Ming
Published: October 2016

In this paper, we studied stacked mL + nL graphene layers using Raman scattering spectroscopy. Our results indicate that the 2D band from stacked graphene can be considered as a superposition of those from the constituent nL and mL graphene layers, and a blueshift in the 2D band is observed when n or m = 1. The blueshift increases with the number of stacked layers and can be well understood by the reduction of Fermi velocity in the single layer graphene, as studied in the 1L + 1L (or twisted bilayer) case. As the number of stacked layers changes from 1 to 5, the Fermi velocity in the single layer graphene reduces to about 85% of its initial value. This study shows a convenient way to realize the modification of the Fermi velocity in free-stacking graphene and is of significance to the applications of graphene-based heterostructures.
Crystal structure analysis in solution-processed uniaxially oriented polycrystalline thin film of non-peripheral octahexyl phthalocyanine by grazing incidence wide-angle x-ray scattering techniques
Authors: Ohmori Masashi , Uno Takashi , Nakatani Mitsuhiro , Nakano Chika , Fujii Akihiko , Ozaki Masanori
Published: October 2016

Uniaxially oriented thin films of metal-free non-peripherally octahexyl-substituted phthalocyanine (C6PcH2), which exhibits high carrier mobility, have been fabricated by the bar-coating technique, which is a simple solution process. The molecular orientation and molecular steps in the thin film were observed by the polarized spectroscopy and the atomic force microscopy, respectively. The three-dimensional molecular packing structure in the thin film was investigated by the grazing incidence wide-angle X-ray scattering technique with an in-plane sample rotation. The crystal orientation was clarified, and the three-dimensional molecular packing structure of the thin film was found to match the single crystal structure. Moreover, the X-ray diffraction patterns of the oriented thin films were simulated by using the lattice parameters of C6PcH2 single crystal to reproduce the observed X-ray diffraction patterns.
Room-temperature mid-infrared interband cascade vertical-cavity surface-emitting lasers
Authors: Bewley W. W. , Canedy C. L. , Kim C. S. , Merritt C. D. , Warren M. V. , Vurgaftman I. , Meyer J. R. , Kim M.
Published: October 2016

We report interband cascade vertical-cavity surface-emitting lasers (ICVCSELs) that operate in pulsed mode at temperatures up to 70 °C. Their emission at λ ≈ 3.4 μm extends considerably the previous longest wavelength of 3.0 μm for an electrically-pumped vertical-cavity surface-emitting laser operating at room temperature. The output from mesas having diameters ranging from 30 to 60 μm (with emission aperture diameters of 20–50 μm) is circularly symmetric, and the threshold current densities at T = 25 °C are as low as 390 A/cm2. However, the differential slope efficiencies are low, e.g., ≤50 mW/A at T = 25 °C, due to loss in the top and bottom mirrors and reduced current efficiency. The smallest device operates in a single spectral mode despite having an emission aperture much wider than the wavelength.
Moderate repetition rate ultra-intense laser targets and optics using variable thickness liquid crystal films
Authors: Poole P. L. , Willis C. , Cochran G. E. , Hanna R. T. , Andereck C. D. , Schumacher D. W.
Published: October 2016

Liquid crystal films are variable thickness, planar targets for ultra-intense laser matter experiments such as ion acceleration. Their target qualities also make them ideal for high-power laser optics such as plasma mirrors and waveplates. By controlling parameters of film formation, thickness can be varied on-demand from 10 nm to above 50 μm, enabling real-time optimization of laser interactions. Presented here are results using a device that draws films from a bulk liquid crystal source volume with any thickness in the aforementioned range. Films form within 2 μm of the same location each time, well within the Rayleigh range of even tight F/# systems, thus removing the necessity for realignment between shots. The repetition rate of the device exceeds 0.1 Hz for sub-100 nm films, facilitating higher repetition rate operation of modern laser facilities.
Enhancement of 1.5 μm emission under 980 nm resonant excitation in Er and Yb co-doped GaN epilayers
Authors: Wang Q. W. , Li J. , Lin J. Y. , Jiang H. X.
Published: October 2016

The Erbium (Er) doped GaN is a promising gain medium for optical amplifiers and solid-state high energy lasers due to its high thermal conductivity, wide bandgap, mechanical hardness, and ability to emit in the highly useful 1.5 μm window. Finding the mechanisms to enhance the optical absorption efficiency at a resonant pump wavelength and emission efficiency at 1.5 μm is highly desirable. We report here the in-situ synthesis of the Er and Yb co-doped GaN epilayers (Er + Yb:GaN) by metal-organic chemical vapor deposition (MOCVD). It was observed that the 1.5 μm emission intensity of the Er doped GaN (Er:GaN) under 980 nm resonant pump can be boosted by a factor of 7 by co-doping the sample with Yb. The temperature dependent PL emission at 1.5 μm in the Er + Yb:GaN epilayers under an above bandgap excitation revealed a small thermal quenching of 12% from 10 to 300 K. From these results, it can be inferred that the process of energy transfer from Yb3+ to Er3+ ions is highly efficient, and non-radiative recombination channels are limited in the Er + Yb:GaN epilayers synthesized in-situ by MOCVD. Our results point to an effective way to improve the emission efficiency of the Er doped GaN for optical amplification and lasing applications.
Square wave voltages-induced ON states of organic resistive memory devices
Authors: Qin Jiajun , Chu Ming , Peng Huan , Zhang Jiawei , Hou Xiaoyuan
Published: October 2016

In organic resistive memory device field, alternating current (AC) has seldom been studied systematically. In the present work, square wave voltage pulses are considered to obtain memory switching to the ON state with voltage amplitude lower than the threshold voltage of the device, even with less time. The ON states induced by such AC depend on both frequency and amplitude. A possible mechanism related to filamentary formation was proposed to explain the AC induced effect.
Prompt gamma ray diagnostics and enhanced hadron-therapy using neutron-free nuclear reactions
Authors: Giuffrida L. , Margarone D. , Cirrone G. A. P. , Picciotto A. , Cuttone G. , Korn G.
Published: October 2016

We propose a series of simulations about the potential use of Boron isotopes to trigger neutron-free (aneutronic) nuclear reactions in cancer cells through the interaction with an incoming energetic proton beam, thus resulting in the emission of characteristic prompt gamma radiation (429 keV, 718 keV and 1435 keV). Furthermore assuming that the Boron isotopes are absorbed in cancer cells, the three alpha-particles produced in each p-11B aneutronic nuclear fusion reactions can potentially result in the enhancement of the biological dose absorbed in the tumor region since these multi-MeV alpha-particles are stopped inside the single cancer cell, thus allowing to spare the surrounding tissues. Although a similar approach based on the use of 11B nuclei has been proposed in [Yoon et al. Applied Physics Letters 105, 223507 (2014)], our work demonstrate, using Monte Carlo simulations, the crucial importance of the use of 10B nuclei (in a solution containing also 11B) for the generation of prompt gamma-rays, which can be applied to medical imaging. In fact, we demonstrate that the use of 10B nuclei can enhance the intensity of the 718 keV gamma-ray peak more than 30 times compared to the solution containing only 11B nuclei. A detailed explanation of the origin of the different prompt gamma-rays, as well as of their application as real-time diagnostics during a potential cancer treatment, is here discussed.
A Green and Convenient Route for the Regioselective Synthesis of New Substituted 3-Aryl-5H-indeno[1,2-c]pyridazines as Potential Monoamine Oxidase Type A Inhibitors
Authors: Rimaz Mehdi , Aali Farkhondeh , Khalili Behzad , Prager Rolf H.
Published: October 2016

Several indeno[1,2-c]pyridazines were efficiently synthesised using the one-pot, three-component reaction of substituted indanones, arylglyoxalmonohydrates, and hydrazine in the presence of 1,5-diazabicyclo[4,3,0]non-5-ene (DBN) in water at room temperature. These substituted 3-aryl indeno[1,2-c]pyridazines can be considered as potential monoamine oxidase type A (MAOA) inhibitors. The advantages of this new strategy are the novelty of the indenopyridazine derivatives, high regioselectivity, use of water as the solvent, no requirement for toxic metal catalysts, and good to excellent yields.
Nascent RNA sequencing reveals distinct features in plant transcription
Authors: Hetzel Jonathan , Duttke Sascha H. , Benner Christopher , Chory Joanne
Published: October 2016

Significance

Transcription is a fundamental and dynamic step in the regulation of gene expression, but the characteristics of plant transcription are poorly understood. We adapted the global nuclear run-on sequencing (GRO-seq) and 5′GRO-seq methods for plants and provide a plant version of the next-generation sequencing software HOMER (
homer.ucsd.edu/homer/plants
) to facilitate data analysis. Mapping nascent transcripts in
Arabidopsis thaliana
seedlings enabled identification of known and novel transcripts and precisely mapped their start sites, revealing distinct characteristics in plant transcription. Our modified method to map engaged RNA polymerases and nascent transcripts in primary tissues paves the way for comparative and response studies.
Site-specific colloidal crystal nucleation by template-enhanced particle transport
Authors: Mishra Chandan K. , Sood A. K. , Ganapathy Rajesh
Published: October 2016

Significance

The deliberate positioning of nano- and microstructures on surfaces is often a prerequisite for fabricating functional devices. Whereas template-assisted nucleation is a promising route to self-assemble these structures, its success hinges on particles reaching target sites prior to nucleation. Thus, for larger building blocks like nanoparticles and colloids, the low surface mobilities impose an impractical upper bound on the maximum achievable separation between surface features. Here, we engineered surfaces with energy gradients that not only aided in transporting particles to target sites but also dictated the size and symmetry of the growing crystallites. Remarkably, the enhancement in particles’ surface mean-free path allows control over nucleation density in a regime that cannot be accessed in conventional template-assisted growth.
Retinol and ascorbate drive erasure of epigenetic memory and enhance reprogramming to naïve pluripotency by complementary mechanisms
Authors: Hore Timothy Alexander , von Meyenn Ferdinand , Ravichandran Mirunalini , Bachman Martin , Ficz Gabriella , Oxley David , Santos Fátima , Balasubramanian Shankar , Jurkowski Tomasz P. , Reik Wolf
Published: October 2016

Significance

Naïve embryonic stem cells are characterized by genome-wide low levels of cytosine methylation, a property that may be intrinsic to their function. We found that retinol/retinoic acid (vitamin A) and ascorbate (vitamin C) synergistically diminish DNA methylation levels and in doing so enhance the generation of naïve pluripotent stem cells. This is achieved by two complementary mechanisms. Retinol increases cellular levels of TET proteins (which oxidize DNA methylation), whereas ascorbate affords them greater activity by reducing cellular Fe
3+
to Fe
2+
. This mechanistic insight is relevant for the production of induced pluripotent stem cells used in regenerative medicine, and contributes to our understanding of how the genome is connected to extrinsic and intrinsic signals.
Effect of holding pressure on densification and mechanical properties of Cf/Mg composites
Authors: Wei X. , Qi L. , Ju L. , Tian W. , Hou X. , Li H.
Published: October 2016

Carbon fibre reinforced magnesium alloy matrix composites were fabricated by using liquid–solid extrusion directly following vacuum infiltration technique. The experimental results showed that the microstructures of Cf/Mg composites depended on the holding pressure. The porosity was reduced gradually, and the densification was improved obviously, respectively, with the increase of the holding pressure. The densification, hardness and Ultimate tensile strength of Cf/Mg composites were significantly improved as the holding pressure increased in the range of 0.1–15 MPa. The densification was not obvious, but the UTS of the Cf/Mg composites decreased gradually as the holding pressure increased in the range of 25–45 MPa. The Cf/Mg composites presented a good performance when the holding pressure was about 15 MPa.