bluuebunny/crossref_metadata_2025 huggingface dataset:
The first description of complete invertebrate arginine metabolism pathways implies dose-dependent pathogen regulation in Apostichopus japonicus
Authors: Yina Shao , Chenghua Li , Weiwei Zhang , Zhenhui Wang , Zhimeng Lv
Published: April 2016

In this study, three typical members representative of different arginine metabolic pathways were firstly identified from Apostichopus japonicus, including nitric oxide synthase (NOS), arginase, and agmatinase. Spatial expression analysis revealed that the AjNOS transcript presented negative expression patterns relative to those of Ajarginase or Ajagmatinase in most detected tissues. Furthermore, Vibrio splendidus-challenged coelomocytes and intestine, and LPS-exposed primary coelomocytes could significantly induce AjNOS expression, followed by obviously inhibited Arginase and AjAgmatinase transcripts at the most detected time points. Silencing the three members with two specific siRNAs in vivo and in vitro collectively indicated that AjNOS not only compete with Ajarginase but also with Ajagmatinase in arginine metabolism. Interestingly, Ajarginase and Ajagmatinase displayed cooperative expression profiles in arginine utilization. More importantly, live pathogens of V. splendidus and Vibrio parahaemolyticus co-incubated with primary cells also induced NO production and suppressed arginase activity in a time-dependent at an appropriate multiplicity of infection (MOI) of 10, without non-pathogen Escherichia coli. When increasing the pathogen dose (MOI = 100), arginase activity was significantly elevated, and NO production was depressed, with a larger magnitude in V. splendidus co-incubation. The present study expands our understanding of the connection between arginine’s metabolic and immune responses in non-model invertebrates.
p53-upregulated-modulator-of-apoptosis (PUMA) deficiency affects food intake but does not impact on body weight or glucose homeostasis in diet-induced obesity.
Authors: Litwak Sara A. , Loh Kim , Stanley William J. , Pappas Evan G. , Wali Jibran A. , Selck Claudia , Strasser Andreas , Thomas Helen E. , Gurzov Esteban N.
Published: April 2016

BCL-2 proteins have been implicated in the control of glucose homeostasis and metabolism in different cell types. Thus, the aim of this study was to determine the role of the pro-apoptotic BH3-only protein, p53-upregulated-modulator-of-apoptosis (PUMA), in metabolic changes mediated by diet-induced obesity, using PUMA deficient mice. At 10 weeks of age, knockout and wild type mice either continued consuming a low fat chow diet (6% fat), or were fed with a high fat diet (23% fat) for 14–17 weeks. We measured body composition, glucose and insulin tolerance, insulin response in peripheral tissues, energy expenditure, oxygen consumption and respiratory exchange ratio in vivo. All these parameters were indistinguishable between wild type and knockout mice on chow diet and were modified equally by diet-induced obesity. Interestingly, we observed decreased food intake and ambulatory capacity of PUMA knockout mice on high fat diet. This was associated with increased adipocyte size and fasted leptin concentration in the blood. Our findings suggest that although PUMA is dispensable for glucose homeostasis in lean and obese mice, it can affect leptin levels and food intake during obesity.
Photo-induced reduction of graphene oxide coating on optical waveguide and consequent optical intermodulation
Authors: Chong W. Y. , Lim W. H. , Yap Y. K. , Lai C. K. , De La Rue R. M. , Ahmad H.
Published: April 2016

Increased absorption of transverse-magnetic (TM) - polarised light by a graphene-oxide (GO) coated polymer waveguide has been observed in the presence of transverse-electric (TE) - polarised light. The GO-coated waveguide exhibits very strong photo-absorption of TE-polarised light - and acts as a TM-pass waveguide polariser. The absorbed TE-polarised light causes a significant temperature increase in the GO film and induces thermal reduction of the GO, resulting in an increase in optical-frequency conductivity and consequently increased optical propagation loss. This behaviour in a GO-coated waveguide gives the action of an inverted optical switch/modulator. By varying the incident TE-polarised light power, a maximum modulation efficiency of 72% was measured, with application of an incident optical power level of 57 mW. The GO-coated waveguide was able to respond clearly to modulated TE-polarised light with a pulse duration of as little as 100 μs. In addition, no wavelength dependence was observed in the response of either the modulation (TE-polarised light) or the signal (TM-polarised light).
Effects of Additional Intra-aortic Balloon Counter-Pulsation Therapy to Cardiogenic Shock Patients Supported by Extra-corporeal Membranous Oxygenation
Authors: Lin Lian-Yu , Liao Che-Wei , Wang Chih-Hsien , Chi Nai-Hsin , Yu Hsi-Yu , Chou Nai-Kuan , Hwang Juey-Jen , Lin Jiunn-Lee , Chiang Fu-Tien , Chen Yih-Sharng
Published: April 2016

Extra-corporeal membranous oxygenation (ECMO) has been applied in patients with cardiopulmonary failure. One critical drawback of peripheral ECMO is an increase in left ventricular (LV) afterload which could be counterbalanced by the combination of intra-aortic balloon counter-pulsation (IABP) therapy. We hypothesized that an add-on therapy with IABP could improve outcomes in patients receiving ECMO support. We included patients (>18 years old) from 2002 to 2013 requiring ECMO support due to cardiogenic shock in a medical center. A total of 529 patients (227 ECMO alone and 302 combined IABP plus ECMO) were included. The mortality rates at 2 weeks (48.5 vs. 47.7%) after ECMO implantation were not different between the two groups (ECMO vs. combined group). After adjustment for propensity score and potential confounders, the odds ratios of outcomes within 14 days (combined group vs. ECMO) for poor LV systolic function, high preload, multi-organ failure and mortality were not different. The results remained similar for subgroup analysis. Compared with ECMO alone, combined IABP and ECMO treatment did not improve outcomes in patients with circulatory failure.
A partly-contacted epitaxial lateral overgrowth method applied to GaN material
Authors: Xiao Ming , Zhang Jincheng , Duan Xiaoling , Shan Hengsheng , Yu Ting , Ning Jing , Hao Yue
Published: April 2016

We have discussed a new crystal epitaxial lateral overgrowth (ELO) method, partly-contacted ELO (PC-ELO) method, of which the overgrowth layer partly-contacts with underlying seed layer. The passage also illustrates special mask structures with and without lithography and provides three essential conditions to achieve the PC-ELO method. What is remarkable in PC-ELO method is that the tilt angle of overgrowth stripes could be eliminated by contacting with seed layer. Moreover, we report an improved monolayer microsphere mask method without lithography of PC-ELO method, which was used to grow GaN. From the results of scanning electron microscopy, cathodoluminescence, x-ray diffraction (XRD), transmission electron microscopy and atomic force microscope (AFM), overgrowth layer shows no tilt angle relative to the seed layer and high quality coalescence front (with average linear dislocation density <6.4 × 103 cm−1). Wing stripes peak splitting of the XRD rocking curve due to tilt is no longer detectable. After coalescence, surface steps of AFM show rare discontinuities due to the low misorientation of the overgrowth regions.
Exchange Interactions on the Highest-Spin Reported Molecule: the Mixed-Valence Fe42 Complex
Authors: Aravena Daniel , Venegas-Yazigi Diego , Ruiz Eliseo
Published: April 2016

The finding of high-spin molecules that could behave as conventional magnets has been one of the main challenges in Molecular Magnetism. Here, the exchange interactions, present in the highest-spin molecule published in the literature, Fe42, have been analysed using theoretical methods based on Density Functional Theory. The system with a total spin value S = 45 is formed by 42 iron centres containing 18 high-spin FeIII ferromagnetically coupled and 24 diamagnetic low-spin FeII ions. The bridging ligands between the two paramagnetic centres are two cyanide ligands coordinated to the diamagnetic FeII cations. Calculations were performed using either small Fe4 or Fe3 models or the whole Fe42 complex, showing the presence of two different ferromagnetic couplings between the paramagnetic FeIII centres. Finally, Quantum Monte Carlo simulations for the whole system were carried out in order to compare the experimental and simulated magnetic susceptibility curves from the calculated exchange coupling constants with the experimental one. This comparison allows for the evaluation of the accuracy of different exchange-correlation functionals to reproduce such magnetic properties.
Ambient air pollution, weather changes and outpatient visits for allergic conjunctivitis: A retrospective registry study
Authors: Hong Jiaxu , Zhong Taoling , Li Huili , Xu Jianming , Ye Xiaofang , Mu Zhe , Lu Yi , Mashaghi Alireza , Zhou Ying , Tan Mengxi , Li Qiyuan , Sun Xinghuai , Liu Zuguo , Xu Jianjiang
Published: April 2016

Allergic conjunctivitis is a common problem that significantly impairs patients’ quality of life. Whether air pollution serves as a risk factor for the development of allergic conjunctivitis remains elusive. In this paper, we assess the relationship between air pollutants and weather conditions with outpatient visits for allergic conjunctivitis. By using a time-series analysis based on the largest dataset ever assembled to date, we found that the number of outpatient visits for allergic conjunctivitis was significantly correlated with the levels of NO2, O3 and temperature, while its association with humidity was statistically marginal. No associations between PM10, PM2.5, SO2, or wind velocity and outpatient visits were seen. Subgroup analyses showed that sex seemed to modify the effects of humidity on outpatient visits for allergic conjunctivitis, but not for NO2, O3, or temperature. People younger than 40 were found to be susceptible to changes of all four parameters, while those older than 40 were only consistently affected by NO2 levels. Our findings revealed that higher levels of ambient NO2, O3 and temperature increase the chances of outpatient visits for allergic conjunctivitis. Ambient air pollution and weather changes may contribute to the worsening of allergic conjunctivitis.
An alternative strategy for targeted gene replacement in plants using a dual-sgRNA/Cas9 design
Authors: Zhao Yongping , Zhang Congsheng , Liu Wenwen , Gao Wei , Liu Changlin , Song Gaoyuan , Li Wen-Xue , Mao Long , Chen Beijiu , Xu Yunbi , Li Xinhai , Xie Chuanxiao
Published: April 2016

Precision DNA/gene replacement is a promising genome-editing tool that is highly desirable for molecular engineering and breeding by design. Although the CRISPR/Cas9 system works well as a tool for gene knockout in plants, gene replacement has rarely been reported. Towards this end, we first designed a combinatory dual-sgRNA/Cas9 vector (construct #1) that successfully deleted miRNA gene regions (MIR169a and MIR827a). The deletions were confirmed by PCR and subsequent sequencing, yielding deletion efficiencies of 20% and 24% on MIR169a and MIR827a loci, respectively. We designed a second structure (construct #2) that contains sites homologous to Arabidopsis TERMINAL FLOWER 1 (TFL1) for homology-directed repair (HDR) with regions corresponding to the two sgRNAs on the modified construct #1. The two constructs were co-transformed into Arabidopsis plants to provide both targeted deletion and donor repair for targeted gene replacement by HDR. Four of 500 stably transformed T0 transgenic plants (0.8%) contained replaced fragments. The presence of the expected recombination sites was further confirmed by sequencing. Therefore, we successfully established a gene deletion/replacement system in stably transformed plants that can potentially be utilized to introduce genes of interest for targeted crop improvement.
4D (x-y-z-t) imaging of thick biological samples by means of Two-Photon inverted Selective Plane Illumination Microscopy (2PE-iSPIM)
Authors: Lavagnino Zeno , Sancataldo Giuseppe , d’Amora Marta , Follert Philipp , De Pietri Tonelli Davide , Diaspro Alberto , Cella Zanacchi Francesca
Published: April 2016

In the last decade light sheet fluorescence microscopy techniques, such as selective plane illumination microscopy (SPIM), has become a well established method for developmental biology. However, conventional SPIM architectures hardly permit imaging of certain tissues since the common sample mounting procedure, based on gel embedding, could interfere with the sample morphology. In this work we propose an inverted selective plane microscopy system (iSPIM), based on non-linear excitation, suitable for 3D tissue imaging. First, the iSPIM architecture provides flexibility on the sample mounting, getting rid of the gel-based mounting typical of conventional SPIM, permitting 3D imaging of hippocampal slices from mouse brain. Moreover, all the advantages brought by two photon excitation (2PE) in terms of reduction of scattering effects and contrast improvement are exploited, demonstrating an improved image quality and contrast compared to single photon excitation. The system proposed represents an optimal platform for tissue imaging and it smooths the way to the applicability of light sheet microscopy to a wider range of samples including those that have to be mounted on non-transparent surfaces.
Relationships between plasma leptin levels, leptin G2548A, leptin receptor Gln223Arg polymorphisms and gestational diabetes mellitus in Chinese population
Authors: Yang Mei , Peng Songxu , Li Wei , Wan Zhihua , Fan Linlin , Du Yukai
Published: April 2016

The purposes of this study were to examine concentrations of leptin and biochemical parameters in gestational diabetes mellitus (GDM) patients and normal glucose tolerance (NGT) individuals and also to explore the links of leptin (LEP) G2548A and leptin receptor (LEPR) Gln223Arg polymorphisms with leptin levels and GDM risk among Chinese. Our study included 357 GDM and 355 NGT individuals who were at 24~30 gestational weeks. Plasma leptin and insulin levels were analyzed by ELISA. Gene polymorphisms were genotyped using TaqMan real-time polymerase chain reaction assay. The results showed that plasma leptin levels were significantly higher in the impaired fasting glucose (IFG) group than NGT group (34.35 (26.54, 56.48) ng/mL vs 26.31 (17.99, 37.87) ng/mL, P < 0.05). Plasma leptin levels correlated with plasma fasting insulin levels, pre-pregnant body mass index, homeostasis model assessment-insulin resistance and quantitative insulin sensitivity check index both in GDM and NGT group (P < 0.05). However, neither LEP G2548A nor LEPR Gln223Arg polymorphisms were significantly associated with GDM risk and plasma leptin levels (P > 0.05). Our findings showed that high leptin level was associated with GDM. And larger and more rigorous researches were needed to further explore the association of LEP and LEPR gene polymorphisms and GDM among Chinese population.
Evaluation of genetic diversity among strains of the human gut commensal Bifidobacterium adolescentis
Authors: Duranti Sabrina , Milani Christian , Lugli Gabriele Andrea , Mancabelli Leonardo , Turroni Francesca , Ferrario Chiara , Mangifesta Marta , Viappiani Alice , Sánchez Borja , Margolles Abelardo , van Sinderen Douwe , Ventura Marco
Published: April 2016

Bifidobacteria are members of the human gut microbiota, being numerically dominant in the colon of infants, while also being prevalent in the large intestine of adults. In this study, we determined and analyzed the pan-genome of Bifidobacterium adolescentis, which is one of many bacteria found in the human adult gut microbiota. In silico analysis of the genome sequences of eighteen B. adolescentis strains isolated from various environments, such as human milk, human feces and bovine rumen, revealed a high level of genetic variability, resulting in an open pan-genome. Compared to other bifidobacterial taxa such as Bifidobacterium bifidum and Bifidobacterium breve, the more extensive B. adolescentis pan-genome supports the hypothesis that the genetic arsenal of this taxon expanded so as to become more adaptable to the variable and changing ecological niche of the gut. These increased genetic capabilities are particularly evident for genes required for dietary glycan-breakdown.
Possible association of CCDC62 rs12817488 polymorphism and Parkinson’s disease risk in Chinese population: a meta-analysis
Authors: Lu Yanjun , Tan Lu , Shen Na , Peng Jing , Wang Chunyu , Zhu Yaowu , Wang Xiong
Published: April 2016

Conflicting results identifying the association between coiled-coil domain containing 62 (CCDC62) polymorphism, rs12817488 and Parkinson’s disease (PD) have been reported. To clarify whether rs12817488 is related to PD risk in Chinese population, we carried out this meta-analysis by searching literature from PubMed and Embase database regarding this polymorphism. Three eligible studies involving 1616 cases and 1649 controls were included in this meta-analysis. Our results showed statistically significant association between rs12817488 and PD risk in all four genetic models. Stratification by gender revealed similar results in both subgroup in these genetic models except for recessive model, in which rs12817488 was not significantly associated with PD in male subgroup. Unstable result was found in recessive model via sensitivity analysis and publication bias was observed in recessive model as well, indicating that the pooled result from recessive model should be cautiously treated. Our meta-analysis implicates a possible relationship between rs12817488 and PD risk in Chinese population. Further validation of this association in large sample size study with different gender is warranted.
A rare variant at 11p13 is associated with tuberculosis susceptibility in the Han Chinese population
Authors: Chen Cheng , Zhao Qi , Hu Yi , Shao Yan , Li Guoli , Zhu Limei , Lu Wei , Xu Biao
Published: April 2016

Genome-wide association studies (GWASs) have yet to be conducted for tuberculosis (TB) susceptibility in China. Two previously identified single nucleotide polymorphisms (SNPs) from tuberculosis GWASs, rs2057178 and rs4331426, were evaluated for TB predisposition. The associations between SNPs and gene expression levels were analyzed using the genomic data and corresponding whole-genome expression of the Han Chinese in Beijing, China. Genotyping was successfully completed for 763 pulmonary TB patients and 763 healthy controls. The T allele of the rare variant rs2057178 was significantly associated with TB predisposition (χ2 = 14.07,P = 0.0002). Meanwhile, the CT genotype of rs2057178 was associated with a decreased risk of TB (adjusted OR = 0.52, 95% CI, 0.34–0.78). The CT genotype of rs2057178 was also associated with decreased expression levels of infection-related gene, suppressor of cytokine signaling 2 (SOCS2) and increased expression levels of v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog B (MAFB). No gene expression levels were found to be associated with the genotype of rs4331426. We found that the rare variant rs2057178 was significantly associated with TB in the Han Chinese population. Moreover, the expression levels of MAFB and SOCS2 correlated with rs2057178 and might be potential candidates for assessing TB susceptibility.
High-temperature water gas shift reaction on Ni–Cu/CeO2 catalysts: effect of ceria nanocrystal size on carboxylate formation
Authors: Saw Eng Toon , Oemar Usman , Ang Ming Li , Kus Hidajat , Kawi Sibudjing
Published: April 2016

The WGS mechanism strongly depends on the Ni–Cu surface composition.
Theoretical insights into the origin of magnetic exchange and magnetic anisotropy in {ReIV–MII} (M = Mn, Fe, Co, Ni and Cu) single chain magnets
Authors: Singh Saurabh Kumar , Vignesh Kuduva R. , Archana Velloth , Rajaraman Gopalan
Published: April 2016

Density functional calculations have been performed on a series of {ReIV–MII} (M = Mn(1), Fe(2), Co(3), Ni(4), Cu(5)) complexes to compute the magnetic exchange interaction between the ReIV and MII ions, and understand the mechanism of magnetic coupling in this series.
Homopiperazine sulfamic acid functionalized mesoporous silica nanoparticles (MSNs-HPZ-SO3H) as an efficient catalyst for one-pot synthesis of 1-amidoalkyl-2-naphthols
Authors: Nasresfahani Zahra , Kassaee Mohammad Zaman , Eidi Esmaiel
Published: April 2016

MSNs-HPZ-SO3H was synthesized, characterized, and employed as an efficient nanocatalyst in one-pot synthesis of 1-amidoalkyl-2-naphthols.
Nitrogen doped holey carbon nano-sheets as anodes in sodium ion battery
Authors: Vadahanambi Sridhar , Chun Ho-Hwan , Jung Kwang Hyo , Park Hyun
Published: April 2016

Microwave synthesis of nitrogen doped mesoporous holey carbon nano-sheets as anode in sodium ion batteries to accommodate the 55% larger sodium ion than its lithium counterpart.
One-pot synthesis of amides from carboxylic acids activated using thionyl chloride
Authors: Leggio A. , Belsito E. L. , De Luca G. , Di Gioia M. L. , Leotta V. , Romio E. , Siciliano C. , Liguori A.
Published: April 2016

We report on a one-pot synthesis of secondary and tertiary amides from carboxylic acids and amines in the presence of a tertiary amine by using thionyl chloride.
Preparation and characterization of alginate/HACC/oyster shell powder biocomposite scaffolds for potential bone tissue engineering applications
Authors: Chen Tai-ying , Huang Hao-chao , Cao Jia-lin , Xin Yan-jiao , Luo Wen-feng , Ao Ning-jian
Published: April 2016

Tissue engineering scaffolds combining biominerals and natural polymers are prospective candidates for bone repair materials.
Insights into the effects of different acids on the formation and electrochemical properties of carbon spherules
Authors: Yan Jiao , Wu Haixia , Shen Wenzhuo , Guo Shouwu
Published: April 2016

Monodispersed and size-controlled carbon spherules have great potential in many different applications.
Substrate modulus regulates osteogenic differentiation of rat mesenchymal stem cells through integrin β1 and BMP receptor type IA
Authors: Guo R. , Lu S. , Merkel A. R. , Sterling J. A. , Guelcher S. A.
Published: April 2016

Osteoblast differentiation of mesenchymal stem cells is regulated by both soluble factor (e.g., bone morphogenetic proteins (BMP)) and mechanically transduced signaling, but the mechanisms have only been partially elucidated.
Insights into metal–ligand hydrogen transfer: a square-planar ruthenate complex supported by a tetradentate amino–amido-diolefin ligand
Authors: Prokopchuk Demyan E. , Lough Alan J. , Rodriguez-Lugo Rafael E. , Morris Robert H. , Grützmacher Hansjörg
Published: April 2016

A unique square planar anionic ruthenium(0) complex with amido and amine donors undergoes rapid NH oxidative addition/elimination reactions.
In situ activation of a doxorubicin prodrug using imaging-capable nanoparticles
Authors: Khan Irfan , Agris Paul F. , Yigit Mehmet V. , Royzen Maksim
Published: April 2016

A general strategy for image-guided prodrug activation using fluorescently-labeled magnetic iron oxide nanoparticles is described.
Furanosic forms of sugars: conformational equilibrium of methyl β-d-ribofuranoside
Authors: Écija Patricia , Uriarte Iciar , Spada Lorenzo , Davis Benjamin G. , Caminati Walther , Basterretxea Francisco J. , Lesarri Alberto , Cocinero Emilio J.
Published: April 2016

The rotational spectrum of the isolated ribofuranoside unit, the biologically active sugar form, revealed two structures with a similar puckering to the RNA units in crystals.
Stöber strategy for synthesizing multifluorescent organosilica nanocrystals
Authors: Yang Lingang , Wang Lingzhi , Cui Chuanfeng , Lei Juying , Zhang Jinlong
Published: April 2016

We first report the Stöber synthesis of diamond-structured fluorescent organosilica nanocrystals (OSNCs) with finely tunable fluorescence (460–625 nm).
Controlling nanowire nucleation and growth with a negative substrate bias
Authors: Ball J. , Reehal H. S.
Published: April 2016

Applying a voltage bias to silicon nanowires during growth can influence wire density, diameter and length.
Theoretical investigation of an ultrastable one dimensional infinite monatomic mixed valent gold wire with excellent electronic properties
Authors: Zhu Chun , Liang Jin-Xia , Wei Gang
Published: April 2016

A one-dimensional monatomic gold wire with mixed-valent Au3+ and Au0 exhibits excellent conductivity and strong visible absorption.
Highly efficient synthesis of flavones via Pd/C-catalyzed cyclocarbonylation of 2-iodophenol with terminal acetylenes
Authors: Zhu Fengxiang , Li Yahui , Wang Zechao , Wu Xiao-Feng
Published: April 2016

A highly efficient and selective Pd/C-catalyzed carbonylation reaction for the synthesis of flavones has been developed. Various flavone derivatives were isolated in excellent yields with excellent functional group tolerances. The catalyst is reusable, and no phosphine ligand or inert gas protection is needed.
Environmental Science: Nano – immediacy index and more
Authors: Grassian Vicki H.
Published: April 2016

Vicki Grassian, Editor-in-Chief, reflects on the achievements of the Journal so far and announces some changes going forward.
An autoregulatory network between menin and pri-miR-24-1 is required for the processing of its specific modulator miR-24-1 in BON1 cells
Authors: Luzi Ettore , Marini Francesca , Ciuffi Simone , Galli Gianna , Brandi Maria Luisa
Published: April 2016

Multiple endocrine neoplasia type 1 (MEN1) is a rare hereditary cancer complex syndrome manifesting a variety of endocrine and non-endocrine neoplasms and lesions.
Cholecystokinin-1 receptor antagonists: 5-hydroxy-5-aryl-pyrrol-2-ones as anticancer agents
Authors: Lattmann E. , Russell S. T. , Schwalbe C. H. , Shortt A. , Balaram P. N. , Theochari E. , Alharbi M. , Narayanan R. , Lattmann P.
Published: April 2016

Hydroxy-pyrrolones, which were potent CCK1R antagonists, showed nanomolarin vitroactivity and anticancer activityin vivofor colon and pancreatic cancer.
Tailoring the structure of polymer networks with iniferter-mediated photo-growth
Authors: Singh Awaneesh , Kuksenok Olga , Johnson Jeremiah A. , Balazs Anna C.
Published: April 2016

In the presence of light, variations in the trithiocarbonate (TTC) concentration provide a new approach for controllably tailoring the structure of polymer gels.
Metal powder–pure water system for rational synthesis of metal oxide functional nanomaterials: a general, facile and green synthetic approach
Authors: Li Lingjie , Zhang Jie , Lei Jinglei , Xu Jing , Liu Peipei , Li Nianbing , Pan Fusheng
Published: April 2016

A general and facile approach for synthesis of metal oxide functional nanomaterials based upon a metal powder–pure water system.
An efficient synthesis of 1-arylindazole-3-carboxamides using nitrile imines, isocyanides and 2-hydroxymethylbenzoic acid, followed by a chemoselective Buchwald–Hartwig intramolecular cyclization
Authors: Giustiniano M. , Mercalli V. , Novellino E. , Tron G. C.
Published: April 2016

A convergent, efficient and regio-selective two-step synthesis of pharmaceutically relevant 1-arylindazole-3-carboxamides through an isocyanide-based reaction and a Buchwald–Hartwig cyclization.
Synthesis of rare-earth doped ZnO nanorods and their defect–dopant correlated enhanced visible-orange luminescence
Authors: Layek A. , Banerjee S. , Manna B. , Chowdhury A.
Published: April 2016

Rare-earth doped sub-10 nm diameter ZnO nanorods show defect–dopant assisted enhanced visible-orange luminescence and also display multicolour rare-earth emission.
Enhanced photocatalytic CO2 conversion over LaPO4 by introduction of CoCl2 as a hole mediator
Authors: Pan Bao , Zhou Yangen , Su Wenyue , Wang Xuxu
Published: April 2016

Significantly enhanced photocatalytic CO2 reduction activity over LaPO4 was achieved by introducing molecular cocatalyst CoCl2 as hole mediator.
CdIn2S4 quantum dots: novel solvent-free synthesis, characterization and enhancement of dye-sensitized solar cells performance
Authors: Mousavi-Kamazani Mehdi , Zarghami Zabihullah , Salavati-Niasari Masoud , Amiri Omid
Published: April 2016

Herein, CdIn2S4 (CdIS) quantum dots were synthesized via a solid-state thermal decomposition approach for the first time.
Effect of reduction/oxidation annealing on the dielectric relaxation and electrical properties of Aurivillius Na0.5Gd0.5Bi4Ti4O15 ceramics
Authors: Rehman Fida , Jin Hai-Bo , Li Jing-Bo
Published: April 2016

(a) Arrhenius plots of ac conductivity of argon and oxygen annealed and as-sintered samples at 100 Hz. (b) Variation of relaxation frequency vs. temperature of NGBT ceramics.
Marcus-type driving force correlations reveal the mechanism of proton-coupled electron transfer for phenols and [Ru(bpy)3]3+ in water at low pH
Authors: Soetbeer Janne , Dongare Prateek , Hammarström Leif
Published: April 2016

We examined PCET between a series of phenol derivatives and photogenerated [Ru(bpy)3]3+ in low pH (≤4) water using the laser flash-quench technique.
Macrocyclic squaramides: anion receptors with high sulfate binding affinity and selectivity in aqueous media
Authors: Qin Lei , Hartley Anna , Turner Peter , Elmes Robert B. P. , Jolliffe Katrina A.
Published: April 2016

Macrocyclic squaramide derivatives bind sulfate ions with high selectivity and affinity in aqueous mixtures.
Millimeter-area, free standing, phospholipid bilayers
Authors: Beltramo Peter J. , Van Hooghten Rob , Vermant Jan
Published: April 2016

A platform to generate and study free standing, planar, phospholipid bilayers with millimeter scale areas and controllable membrane tension is presented.
Targeting mitochondrial DNA with a two-photon active Ru(ii) phenanthroline derivative
Authors: Wang Hui , Tian Xiaohe , Guan Lijuan , Zhang Qiong , Zhang Shengyi , Zhou Hongping , Wu Jieying , Tian Yupeng
Published: April 2016

A novel phenanthroline Ru(ii) derivative for targeting mitochondrial DNA was designed and its potential applications in biological processes were highlighted.
Tough and responsive oppositely charged nanocomposite hydrogels for use as bilayer actuators assembled through interfacial electrostatic attraction
Authors: Liu Shuhui , Gao Guorong , Xiao Ying , Fu Jun
Published: April 2016

Tough nanocomposite hydrogels carrying opposite charges were assembled through interfacial electrostatic attraction into Janus bilayer actuators.
A giant negative electrocaloric effect in Eu-doped PbZrO3 thin films
Authors: Ye Mao , Li Tao , Sun Qiu , Liu Zhikai , Peng Biaolin , Huang Chuanwei , Lin Peng , Ke Shanming , Zeng Xierong , Peng Xiang , Chen Lang , Huang Haitao
Published: April 2016

A negative electrocaloric effect (ECE) in 4 mol% Eu-doped PbZrO3 antiferroelectric (AFE) thin films prepared by using a sol–gel method is investigated via indirect measurements.
Spatio-temporal linear stability analysis of stratified planar wakes: Velocity and density asymmetry effects
Authors: Emerson Benjamin , Jagtap Swapnil , Quinlan J. Mathew , Renfro Michael W. , Cetegen Baki M. , Lieuwen Tim
Published: April 2016

This paper explores the hydrodynamic stability of bluff body wakes with non-uniform mean density, asymmetric mean density, and velocity profiles. This work is motivated by experiments [S. Tuttle et al., “Lean blow off behavior of asymmetrically-fueled bluff body-stabilized flames,” Combust. Flame 160, 1677 (2013)], which investigated reacting wakes with equivalence ratio stratification and, hence, asymmetry in the base flow density profiles. They showed that highly stratified cases exhibited strong, narrowband oscillations, suggestive of global hydrodynamic instability. In this paper, we present a local hydrodynamic stability analysis for non-uniform density wakes that includes base flow asymmetry. The results show that increasing the degree of base density asymmetry generally has a destabilizing effect and that increasing base velocity asymmetry tends to be stabilizing. Furthermore, we show that increasing base density asymmetry slightly decreases the absolute frequency and that increasing the base velocity asymmetry slightly increases the absolute frequency. In addition, we show that increasing the degree of base density asymmetry distorts the most absolutely unstable hydrodynamic mode from its nominally sinuous structure. This distorted mode exhibits higher amplitude pressure and velocity oscillations near the interface with the smaller density jump than near the one with the bigger density jump. This would then be anticipated to lead to strongly non-symmetric amplitudes of flame flapping, with much stronger flame flapping on the side with lower density ratio. These predictions are shown to be consistent with experimental data. These comparisons support the analytical predictions that increased base density asymmetry are destabilizing and that hydrodynamic velocity fluctuation amplitudes should be greatest at the flame with the lowest density jump.
Stability of stratified two-phase flows in horizontal channels
Authors: Barmak I. , Gelfgat A. , Vitoshkin H. , Ullmann A. , Brauner N.
Published: April 2016

Linear stability of stratified two-phase flows in horizontal channels to arbitrary wavenumber disturbances is studied. The problem is reduced to Orr-Sommerfeld equations for the stream function disturbances, defined in each sublayer and coupled via boundary conditions that account also for possible interface deformation and capillary forces. Applying the Chebyshev collocation method, the equations and interface boundary conditions are reduced to the generalized eigenvalue problems solved by standard means of numerical linear algebra for the entire spectrum of eigenvalues and the associated eigenvectors. Some additional conclusions concerning the instability nature are derived from the most unstable perturbation patterns. The results are summarized in the form of stability maps showing the operational conditions at which a stratified-smooth flow pattern is stable. It is found that for gas-liquid and liquid-liquid systems, the stratified flow with a smooth interface is stable only in confined zone of relatively low flow rates, which is in agreement with experiments, but is not predicted by long-wave analysis. Depending on the flow conditions, the critical perturbations can originate mainly at the interface (so-called “interfacial modes of instability”) or in the bulk of one of the phases (i.e., “shear modes”). The present analysis revealed that there is no definite correlation between the type of instability and the perturbation wavelength.
Linear and nonlinear instability in vertical counter-current laminar gas-liquid flows
Authors: Schmidt Patrick , Ó Náraigh Lennon , Lucquiaud Mathieu , Valluri Prashant
Published: April 2016

We consider the genesis and dynamics of interfacial instability in vertical gas-liquid flows, using as a model the two-dimensional channel flow of a thin falling film sheared by counter-current gas. The methodology is linear stability theory (Orr-Sommerfeld analysis) together with direct numerical simulation of the two-phase flow in the case of nonlinear disturbances. We investigate the influence of two main flow parameters on the interfacial dynamics, namely the film thickness and pressure drop applied to drive the gas stream. To make contact with existing studies in the literature, the effect of various density contrasts is also examined. Energy budget analyses based on the Orr-Sommerfeld theory reveal various coexisting unstable modes (interfacial, shear, internal) in the case of high density contrasts, which results in mode coalescence and mode competition, but only one dynamically relevant unstable interfacial mode for low density contrast. A study of absolute and convective instability for low density contrast shows that the system is absolutely unstable for all but two narrow regions of the investigated parameter space. Direct numerical simulations of the same system (low density contrast) show that linear theory holds up remarkably well upon the onset of large-amplitude waves as well as the existence of weakly nonlinear waves. For high density contrasts, corresponding more closely to an air-water-type system, linear stability theory is also successful at determining the most-dominant features in the interfacial wave dynamics at early-to-intermediate times. Nevertheless, the short waves selected by the linear theory undergo secondary instability and the wave train is no longer regular but rather exhibits chaotic motion. The same linear stability theory predicts when the direction of travel of the waves changes — from downwards to upwards. We outline the practical implications of this change in terms of loading and flooding. The change in direction of the wave propagation is represented graphically in terms of a flow map based on the liquid and gas flow rates and the prediction carries over to the nonlinear regime with only a small deviation.
The flip-flopping wake pattern behind two side-by-side circular cylinders: A global stability analysis
Authors: Bai Xiao-Dong , Zhang Wei , Guo An-Xin , Wang Yong
Published: April 2016

A global stability analysis is performed for the flip-flopping wake pattern behind two side-by-side cylinders with emphasis on the unstable vorticity field. The combination of direct numerical simulation with the state-of-art lattice Boltzmann method and dynamic mode decomposition is used to analyse such wake pattern for the first time. The vorticity mode of the secondary instability is extracted from the flow. Such mode is found to be symmetrical with respect to the geometric axis of symmetry. Furthermore, a new scenario is found for the high order harmonics that there is a pair of two tertiary modes as a result of nonlinear interaction between the mode related to the secondary instability and the global mode of the in-phase synchronized vortex shedding base flow. Besides, the reason for the Fourier spectra of the lift on the two cylinders being the same is also illustrated for this case.
On the validity of the quasi-steady-turbulence hypothesis in representing the effects of large scales on small scales in boundary layers
Authors: Agostini Lionel , Leschziner Michael
Published: April 2016

The “quasi-steady hypothesis,” as understood in the context of large-scale/small-scale interactions in near-wall turbulence, rests on the assumption that the small scales near the wall react within very short time scales to changes imposed on them by energetic large scales whose length scales differ by at least one order of magnitude and whose energy reaches a maximum in the middle to the outer portion of the log-law layer. A key statistical manifestation of this assumption is that scaling the small-scale motions with the large-scale wall-friction-velocity footprints renders the small-scale statistics universal. This hypothesis is examined here by reference to direct numerical simulation (DNS) data for channel flow at Reτ ≈ 4200, subjected to a large-scale/small-scale separation by the empirical mode decomposition method. Flow properties examined include the mean velocity, second moments, joint probability density functions, and skewness. It is shown that the validity of the hypothesis depends on the particular property being considered and on the range of length scales of structures included within the large-scale spectrum. The quasi-steady hypothesis is found to be well justified for the mean velocity and streamwise energy of the small scales up to y+∼O(80), but only up to y+∼O(30) for other properties.
Design of a collective scattering system for small scale turbulence study in Korea Superconducting Tokamak Advanced Research
Authors: Lee W. , Park H. K. , Lee D. J. , Nam Y. U. , Leem J. , Kim T. K.
Published: April 2016

The design characteristics of a multi-channel collective (or coherent) scattering system for small scale turbulence study in Korea Superconducting Tokamak Advanced Research (KSTAR), which is planned to be installed in 2017, are given in this paper. A few critical issues are discussed in depth such as the Faraday and Cotton-Mouton effects on the beam polarization, radial spatial resolution, probe beam frequency, polarization, and power. A proper and feasible optics with the 300 GHz probe beam, which was designed based on these issues, provides a simultaneous measurement of electron density fluctuations at four discrete poloidal wavenumbers up to 24 cm−1. The upper limit corresponds to the normalized wavenumber kθρe of ∼0.15 in nominal KSTAR plasmas. To detect the scattered beam power and extract phase information, a quadrature detection system consisting of four-channel antenna/detector array and electronics will be employed.
Practical loss tangent imaging with amplitude-modulated atomic force microscopy
Authors: Proksch Roger , Kocun Marta , Hurley Donna , Viani Mario , Labuda Aleks , Meinhold Waiman , Bemis Jason
Published: April 2016

Amplitude-modulated (AM) atomic force microscopy (AFM), also known as tapping or AC mode, is a proven, reliable, and gentle imaging method with widespread applications. Previously, the contrast in AM-AFM has been difficult to quantify. AFM loss tangent imaging is a recently introduced technique that recasts AM mode phase imaging into a single term tan δ that includes both the dissipated and stored energy of the tip-sample interaction. It promises fast, versatile mapping of variations in near-surface viscoelastic properties. However, experiments to date have generally obtained values larger than expected for the viscoelastic loss tangent of materials. Here, we explore and discuss several practical considerations for AFM loss tangent imaging experiments. A frequent limitation to tapping in air is Brownian (thermal) motion of the cantilever. This fundamental noise source limits the accuracy of loss tangent estimation to approximately 0.01<tan δ<5 in air. In addition, surface effects including squeeze film damping, adhesion, and plastic deformation can contribute in a manner consistent with experimentally observed overestimations. For squeeze film damping, we demonstrate a calibration technique that removes this effect at every pixel. Finally, temperature-dependent imaging in a two-component polymeric film demonstrates that this technique can identify temperature-dependent phase transitions, even in the presence of such non-ideal interactions. These results help understand the limits and opportunities not only of this particular technique but also of AM mode with phase imaging in general.
Spin-adapted matrix product states and operators
Authors: Keller Sebastian , Reiher Markus
Published: April 2016

Matrix product states (MPSs) and matrix product operators (MPOs) allow an alternative formulation of the density matrix renormalization group algorithm introduced by White. Here, we describe how non-abelian spin symmetry can be exploited in MPSs and MPOs by virtue of the Wigner–Eckart theorem at the example of the spin-adapted quantum chemical Hamiltonian operator.
On the magnetic anisotropy and nuclear relaxivity effects of Co and Ni doping in iron oxide nanoparticles
Authors: Orlando T. , Albino M. , Orsini F. , Innocenti C. , Basini M. , Arosio P. , Sangregorio C. , Corti M. , Lascialfari A.
Published: April 2016

We report a systematic experimental study of the evolution of the magnetic and relaxometric properties as a function of metal (Co, Ni) doping in iron oxide nanoparticles. A set of five samples, having the same size and ranging from stoichiometric cobalt ferrite (CoFe2O4) to stoichiometric nickel ferrite (NiFe2O4) with intermediate doping steps, was ad hoc synthesized. Using both DC and AC susceptibility measurements, the evolution of the magnetic anisotropy depending on the doping is qualitatively discussed. In particular, we observed that the height of the magnetic anisotropy barrier is directly proportional to the amount of Co, while the Ni has an opposite effect. By Nuclear Magnetic Resonance Dispersion (NMR-D) experiments, the experimental longitudinal r1 and transverse r2 relaxivity profiles were obtained, and the heuristic theory of Roch et al. was used to analyze the data of both r1 and, for the first time, r2. While the experimental and fitting results obtained from r1 profiles were satisfying and confirmed the anisotropy trend, the model applied to r2 hardly explains the experimental findings.
Accessibility investigation of large magnetic entropy change in CoMn1−xFexGe
Authors: Yuce S. , Bruno N. M. , Emre B. , Karaman I.
Published: April 2016

The influence of Fe doping for Mn in CoMn1−xFexGe alloys on their structural and magnetic phase transitions was investigated. CoMn1−xFexGe alloys display a first-order magneto-structural transition from a high temperature paramagnetic hexagonal Ni2In-type crystal structure to a low temperature ferromagnetic orthorhombic TiNiSi-type structure. An entropy change of ΔSM = −32.8 J/kg K was measured and adiabatic temperature change of −8.0 K was computed for the x = 0.085 alloy under a magnetic field of 7 T in the vicinity of the phase transition at 317 K. With increasing Fe content, transition temperatures and magnetic entropy changes decrease. In addition to investigating the effect of replacing Mn with Fe, the accessibility of the giant measured entropy change was quantified by means of the minimum magnetic field required to start and to complete the magneto-structural phase transition.
Planar Hall effect based characterization of spin orbital torques in Ta/CoFeB/MgO structures
Authors: Jamali Mahdi , Zhao Zhengyang , DC Mahendra , Zhang Delin , Li Hongshi , Smith Angeline K. , Wang Jian-Ping
Published: April 2016

The spin orbital torques in Ta/CoFeB/MgO structures are experimentally investigated utilizing the planar Hall effect and magnetoresistance measurement. By angular field characterization of the planar Hall resistance at ±current, the differential resistance which is directly related to the spin orbital torques is derived. Upon curve fitting of the analytical formulas over the experimental results, it is found that the anti-damping torque, also known as spin Hall effect, is sizable while a negligible field-like torque is observed. A spin Hall angle of about 18 ± 0.6% is obtained for the Ta layer. Temperature dependent study of the spin orbital torques is also performed. It is found that temperature does not significantly modify the spin Hall angle. By cooling down the sample down to 100 K, the obtained spin Hall angle has a maximum value of about 20.5 ± 0.43%.
Activated graphene nanoplatelets as a counter electrode for dye-sensitized solar cells
Authors: Gong Jiawei , Zhou Zhengping , Sumathy K. , Yang Huojun , Qiao Qiquan
Published: April 2016

Activated graphene nanoplatelets (aGNPs) prepared by a hydrothermal method using KOH as activating agent were used as counter electrode for high efficiency dye-sensitized solar cells (DSSCs). After the KOH activation, the scanning electron microscopy image shows that aGNPs demonstrate a more curled, rough, and porous morphology which could contain both micro- and mesopores. The KOH activation changed the stacked layers of GNPs to a more crumpled and curved morphology. The microstructure of large pores significantly increased the electrode surface area and roughness, leading to the high electrocatalytic activity for triiodide reduction at the counter electrode. The DSSCs fabricated using aGNP as counter electrodes were tested under standard AM 1.5 illumination with an intensity of 91.5 mW/cm2. The device achieved an overall power conversion efficiency of 7.7%, which is comparable to the conventional platinum counter electrode (8%). Therefore, the low cost and high performance aGNP based counter electrode is a promising alternative to conventional Pt counter electrode in DSSCs.