bluuebunny/crossref_metadata_2025 huggingface dataset:
Crystal structural basis for Rv0315, an immunostimulatory antigen and inactive beta-1,3-glucanase of Mycobacterium tuberculosis
Authors: Dong Wanyu , Huang Junhua , Li Yanan , Tan Yubei , Shen Zhou , Song Yunfeng , Wang Dang , Xiao Shaobo , Chen Huanchun , Fu Zhen F. , Peng Guiqing
Published: October 2015

Mycobacterium tuberculosis (Mtb) remains a leading cause of morbidity and mortality worldwide, as two billion people are latently infected with Mtb. To address Mtb drug resistance and the limitations of current vaccines, the characteristics of candidate Mtb vaccines need to be explored. Here, we report the three-dimensional structure of Rv0315 at 1.70 Å resolution, a novel immunostimulatory antigen of Mtb and demonstrate that Rv0315 is an inactive β-1,3-glucanase of the glycoside hydrolase 16 (GH16) family. Our study further elaborates the molecular basis for the lack of glucan recognition by Rv0315. Rv0315 has a large open groove and this particular topology cannot bind oligosaccharide chains in solution, thus explaining the lack of detectable hydrolytic activity towards its substrate. Additionally, we identified Glu-176, a conserved catalytic residue in GH16 endo-β-1,3-glucanases, as essential for Rv0315 to induce immunological responses. These results indicate that Rv0315 likely diverged from a broad-specificity ancestral GH16 glucanase and this inactive member of the GH16 family offers new insights into the GH16 glucanase. Together, our findings suggest that an inactive β-1,3-glucanase in Mtb drives T-helper 1 (Th1) immune responses, which may help develop more effective vaccines against Mtb infection.
Divergent endometrial inflammatory cytokine expression at peri-implantation period and after the stimulation by copper intrauterine device
Authors: Chou Chia-Hung , Chen Shee-Uan , Shun Chia-Tung , Tsao Po-Nien , Yang Yu-Shih , Yang Jehn-Hsiahn
Published: October 2015

Endometrial inflammation has contradictory effects. The one occurring at peri-implantation period is favourable for embryo implantation, whereas the other occurring after the stimulation by copper intrauterine device (Cu-IUD) prevents from embryo implantation. In this study, 8 week female ICR mice were used to investigate the endometrial inflammation, in which they were at proestrus stage (Group 1), at peri-implantation period (Group 2) and had a copper wire implanted into right uterine horn (Group 3). Cytokine array revealed that two cytokines were highly expressed in Group 2 and Group 3 as compared with Group 1 and seven cytokines, including tumour necrosis factor α (TNF-α), had selectively strong expression in Group 3. Immunohistochemistry demonstrated prominent TNF-α staining on the endometrium after Cu-IUD stimulation and in vitro culture of human endometrial glandular cells with Cu induced TNF-α secretion. The increased TNF-α concentration enhanced in vitro THP-1 cells chemotaxis and reduced embryo implantation rates. These results suggest that inflammatory cytokine profiles of endometrium are different between those at peri-implantation period and after Cu-IUD stimulation and TNF-α is the one with selectively strong expression in the latter. It might account for the contradictory biological effects of endometrial inflammation.
Using AIE Luminogen for Long-term and Low-background Three-Photon Microscopic Functional Bioimaging
Authors: Zhu Zhenfeng , Leung Chris W. T. , Zhao Xinyuan , Wang Yalun , Qian Jun , Tang Ben Zhong , He Sailing
Published: October 2015

Fluorescent probes are one of the most popularly used bioimaging markers to monitor metabolic processes of living cells. However, long-term light excitation always leads to photobleaching of fluorescent probes, unavoidable autofluorescence as well as photodamage of cells. To overcome these limitations, we synthesized a type of photostable luminogen named TPE-TPP with an aggregation induced emission (AIE) characteristic and achieved its three-photon imaging with femtosecond laser excitation of 1020 nm. By using TPE-TPP as fluorescent probes, three-photon microscopy under 1020 nm excitation showed little photo-damage, as well as low autofluorescence to HeLa cells. Due to the AIE effect, the TPE-TPP nanoaggregates uptaken by cells were resistant to photobleaching under three-photon excitation for an extended period of time. Furthermore, we demonstrated that for the present TPE-TPP AIE the three-photon microscopy (with 1020 nm excitation) had a better signal to noise ratio than the two-photon microscopy (with 810 nm excitation) in tissue imaging.
The effect of enamel proteins on erosion
Authors: Baumann T. , Carvalho T. S. , Lussi A.
Published: October 2015

Enamel proteins form a scaffold for growing hydroxyapatite crystals during enamel formation. They are then almost completely degraded during enamel maturation, resulting in a protein content of only 1% (w/v) in mature enamel. Nevertheless, this small amount of remaining proteins has important effects on the mechanical and structural properties of enamel and on the electrostatic properties of its surface. To analyze how enamel proteins affect tooth erosion, human enamel specimens were deproteinated. Surface microhardness (SMH), surface reflection intensity (SRI) and calcium release of both deproteinated and control specimens were monitored while continuously eroding them. The deproteination itself already reduced the initial SMH and SRI of the enamel significantly (p < 0.001 and p < 0.01). During the course of erosion, the progression of all three evaluated parameters differed significantly between the two groups (p < 0.001 for each). The deproteinated enamel lost its SMH and SRI faster and released more calcium than the control group, but these differences were only significant at later stages of erosion, where not only surface softening but surface loss can be observed. We conclude that enamel proteins have a significant effect on erosion, protecting the enamel and slowing down the progression of erosion when irreversible surface loss starts to occur.
Levels of polyunsaturated fatty acids correlate with growth rate in plant cell cultures
Authors: Meï Coline , Michaud Morgane , Cussac Mathilde , Albrieux Catherine , Gros Valérie , Maréchal Eric , Block Maryse A. , Jouhet Juliette , Rébeillé Fabrice
Published: October 2015

In higher plants, fatty acids (FAs) with 18 carbons (18C) represent about 70% of total FAs, the most abundant species being 18:2 and 18:3. These two polyunsaturated FAs (PUFAs) represent about 55% of total FAs in Arabidopsis cell suspension cultures, whereas 18:1 represents about 10%. The level of PUFAs may vary, depending on ill-defined factors. Here, we compared various sets of plant cell cultures and noticed a correlation between the growth rate of a cell population and the level of unsaturation of 18C FAs. These observations suggest that the final level of PUFAs might depend in part on the rate of cell division and that FAD2 and FAD3 desaturases, which are respectively responsible for the formation of 18:2 and 18:3 on phospholipids, have limiting activities in fast-growing cultures. In plant cell culture, phosphate (Pi) deprivation is known to impair cell division and to trigger lipid remodeling. We observed that Pi starvation had no effect on the expression of FAD genes and that the level of PUFAs in this situation was also correlated with the growth rate. Thus, the level of PUFAs appears as a hallmark in determining cell maturity and aging.
Expression profiling of lymph nodes in tuberculosis patients reveal inflammatory milieu at site of infection
Authors: Maji Abhijit , Misra Richa , Kumar Mondal Anupam , Kumar Dhirendra , Bajaj Divya , Singhal Anshika , Arora Gunjan , Bhaduri Asani , Sajid Andaleeb , Bhatia Sugandha , Singh Sompal , Singh Harshvardhan , Rao Vivek , Dash Debasis , Baby Shalini E , Sarojini Michael Joy , Chaudhary Anil , Gokhale Rajesh S. , Singh Yogendra
Published: October 2015

Extrapulmonary manifestations constitute 15 to 20% of tuberculosis cases, with lymph node tuberculosis (LNTB) as the most common form of infection. However, diagnosis and treatment advances are hindered by lack of understanding of LNTB biology. To identify host response, Mycobacterium tuberculosis infected lymph nodes from LNTB patients were studied by means of transcriptomics and quantitative proteomics analyses. The selected targets obtained by comparative analyses were validated by quantitative PCR and immunohistochemistry. This approach provided expression data for 8,728 transcripts and 102 proteins, differentially regulated in the infected human lymph node. Enhanced inflammation with upregulation of T-helper1-related genes, combined with marked dysregulation of matrix metalloproteinases, indicates tissue damage due to high immunoactivity at infected niche. This expression signature was accompanied by significant upregulation of an immunoregulatory gene, leukotriene A4 hydrolase, at both transcript and protein levels. Comparative transcriptional analyses revealed LNTB-specific perturbations. In contrast to pulmonary TB-associated increase in lipid metabolism, genes involved in fatty-acid metabolism were found to be downregulated in LNTB suggesting differential lipid metabolic signature. This study investigates the tissue molecular signature of LNTB patients for the first time and presents findings that indicate the possible mechanism of disease pathology through dysregulation of inflammatory and tissue-repair processes.
Identification of disulfide cross-linked tau dimer responsible for tau propagation
Authors: Kim Dohee , Lim Sungsu , Haque Md. Mamunul , Ryoo Nayeon , Hong Hyun Seok , Rhim Hyewhon , Lee Dong-Eun , Chang Young-Tae , Lee Jun-Seok , Cheong Eunji , Kim Dong Jin , Kim Yun Kyung
Published: October 2015

Recent evidence suggests that tau aggregates are not only neurotoxic, but also propagate in neurons acting as a seed for native tau aggregation. Prion-like tau transmission is now considered as an important pathogenic mechanism driving the progression of tau pathology in the brain. However, prion-like tau species have not been clearly characterized. To identify infectious tau conformers, here we prepared diverse tau aggregates and evaluated the effect on inducing intracellular tau-aggregation. Among tested, tau dimer containing P301L-mutation is identified as the most infectious form to induce tau pathology. Biochemical analysis reveals that P301L-tau dimer is covalently cross-linked with a disulfide bond. The relatively small and covalently cross-linked tau dimer induced tau pathology efficiently in primary neurons and also in tau-transgenic mice. So far, the importance of tau disulfide cross-linking has been overlooked in the study of tau pathology. Here our results suggested that tau disulfide cross-linking might play critical role in tau propagation by producing structurally stable and small tau conformers.
High Elastic Moduli of a 54Al2O3-46Ta2O5 Glass Fabricated via Containerless Processing
Authors: Rosales-Sosa Gustavo A. , Masuno Atsunobu , Higo Yuji , Inoue Hiroyuki , Yanaba Yutaka , Mizoguchi Teruyasu , Umada Takumi , Okamura Kohei , Kato Katsuyoshi , Watanabe Yasuhiro
Published: October 2015

Glasses with high elastic moduli have been in demand for many years because the thickness of such glasses can be reduced while maintaining its strength. Moreover, thinner and lighter glasses are desired for the fabrication of windows in buildings and cars, cover glasses for smart-phones and substrates in Thin-Film Transistor (TFT) displays. In this work, we report a 54Al2O3-46Ta2O5glass fabricated by aerodynamic levitation which possesses one of the highest elastic moduli and hardness for oxide glasses also displaying excellent optical properties. The glass was colorless and transparent in the visible region and its refractive indexndwas as high as 1.94. The measured Young’s modulus and Vickers hardness were 158.3 GPa and 9.1 GPa, respectively, which are comparable to the previously reported highest values for oxide glasses. Analysis made using27Al Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) spectroscopy revealed the presence of a significantly large fraction of high-coordinated Al in addition to four-coordinated Al in the glass. The high elastic modulus and hardness are attributed to both the large cationic field strength of Ta5+ions and the large dissociation energies per unit volume of Al2O3and Ta2O5.
Simultaneous excitation and emission enhancements in upconversion luminescence using plasmonic double-resonant gold nanorods
Authors: Liu Xin , Yuan Lei Dang
Published: October 2015

The geometry and dimension of a gold nanorod (GNR) are optimally designed to enhance the fluorescence intensity of a lanthanide-doped upconversion nanocrystal placed in close proximity to the GNR. A systematic study of the electromagnetic interaction between the upconversion emitter of three energy levels and the GNR shows that the enhancement effect arising from localized electric field-induced absorption can be balanced by the negative effect of electronic transition from an intermediate state to the ground state of the emitter. The dependence of fluorescence enhancement on the emitter-GNR separation is investigated and the results demonstrate a maximum enhancement factor of 120 folds and 160 folds at emission wavelengths 650 and 540 nm, respectively. This is achieved at the emitter-GNR separation ranging from 5 to 15 nm, depending on the initial quantum efficiency of the emitter. The modified upconversion luminescence behavior by adjusting the aspect ratio of the GNR and the relative position of the emitter indicates the dominate role of excitation process in the total fluorescence enhancement. These findings are of great importance for rationally designing composite nanostructures of metal nanoparticles and upconversion nanocrystals with maximized plasmonic enhancement for bioimaging and sensing applications.
An in vitro assessment of liposomal topotecan simulating metronomic chemotherapy in combination with radiation in tumor-endothelial spheroids
Authors: Jyoti Amar , Fugit Kyle D. , Sethi Pallavi , McGarry Ronald C. , Anderson Bradley D. , Upreti Meenakshi
Published: October 2015

Low dose metronomic chemotherapy (LDMC) refers to prolonged administration of low dose chemotherapy designed to minimize toxicity and target the tumor endothelium, causing tumor growth inhibition. Topotecan (TPT) when administered at its maximum tolerated dose (MTD) is often associated with systemic hematological toxicities. Liposomal encapsulation of TPT enhances efficacy by shielding it from systemic clearance, allowing greater uptake and extended tissue exposure in tumors. Extended release of TPT from liposomal formulations also has the potential to mimic metronomic therapies with fewer treatments. Here we investigate potential toxicities of equivalent doses of free and actively loaded liposomal TPT (LTPT) and compare them to a fractionated low dose regimen of free TPT in tumor-endothelial spheroids (TES) with/without radiation exposure for a prolonged period of 10 days. Using confocal microscopy, TPT fluorescence was monitored to determine the accumulation of drug within TES. These studies showed TES, being more reflective of the in vivo tumor microenvironment, were more sensitive to LTPT in comparison to free TPT with radiation. More importantly, the response of TES to low-dose metronomic TPT with radiation was comparable to similar treatment with LTPT. This TES study suggests nanoparticle formulations designed for extended release of drug can simulate LDMC in vivo.
Identification of novel sRNAs involved in biofilm formation, motility and fimbriae formation in Escherichia coli
Authors: Bak Geunu , Lee Jungmin , Suk Shinae , Kim Daun , Young Lee Ji , Kim Kwang-sun , Choi Byong-Seok , Lee Younghoon
Published: October 2015

Bacterial small RNAs (sRNAs) are known regulators in many physiological processes. In Escherichia coli, a large number of sRNAs have been predicted, among which only about a hundred are experimentally validated. Despite considerable research, the majority of their functions remain uncovered. Therefore, collective analysis of the roles of sRNAs in specific cellular processes may provide an effective approach to identify their functions. Here, we constructed a collection of plasmids overexpressing 99 individual sRNAs and analyzed their effects on biofilm formation and related phenotypes. Thirty-three sRNAs significantly affecting these cellular processes were identified. No consistent correlations were observed, except that all five sRNAs suppressing type I fimbriae inhibited biofilm formation. Interestingly, IS118, yet to be characterized, suppressed all the processes. Our data not only reveal potentially critical functions of individual sRNAs in biofilm formation and other phenotypes but also highlight the unexpected complexity of sRNA-mediated metabolic pathways leading to these processes.
Observation of quantum recoherence of photons by spatial propagation
Authors: Bouchard Frédéric , Harris Jérémie , Mand Harjaspreet , Bent Nicolas , Santamato Enrico , Boyd Robert W. , Karimi Ebrahim
Published: October 2015

Entanglement is at the heart of many unusual and counterintuitive features of quantum mechanics. Once two quantum subsystems have become entangled, it is no longer possible to ascribe an independent state to either; instead, the subsystems are completely described only as part of a greater, composite system. As a consequence of this, each entangled subsystem experiences a loss of coherence following entanglement. We refer to this decrease in coherence as decoherence. Decoherence leads inevitably to the leaking of information from each subsystem to the composite entangled system. Here, we demonstrate a process of decoherence reversal, whereby we recover information lost from the entanglement of the optical orbital angular momentum and radial profile degrees of freedom possessed by a photon pair. These results carry great potential significance, since quantum memories and quantum communication schemes depend on an experimenter’s ability to retain the coherent properties of a particular quantum system.
Controlling aqueous silica nanoparticle synthesis in the 10–100 nm range
Authors: Hristov Delyan R. , Mahon Eugene , Dawson Kenneth A.
Published: October 2015

Controlling monomer generation rate in different ways, we broaden the range of sizes attainable for single step aqueous silica nanoparticle synthesis.
Hierarchical ZnO hollow microspheres with exposed (001) facets as promising catalysts for the thermal decomposition of ammonium perchlorate
Authors: Tian Shouqin , Li Neng , Zeng Dawen , Li Haitao , Tang Gen , Pang Aimin , Xie Changsheng , Zhao Xiujian
Published: October 2015

Hierarchical porous ZnO hollow microspheres assembled from nanorods with exposed (001) facets on their external surface exhibited better catalytic activity for the thermal decomposition of ammonium perchlorate (AP) than the dispersed ZnO nanorods.
Comment on “Scaling properties of information-theoretic quantities in density functional reactivity theory” by C. Rong, T. Lu, P. W. Ayers, P. K. Chattaraj and S. Liu, Phys. Chem. Chem. Phys., 2015, 17, 4977–4988
Authors: Bohórquez Hugo J.
Published: October 2015

The linear dependence between the density per particle σ and the electron density ρ facilitates the theoretical study of the N-scaling rules for quantum information functionals and their atomic partitions.
Thermoelectric transport properties of pristine and Na-doped SnSe1−xTex polycrystals
Authors: Wei Tian-Ran , Wu Chao-Feng , Zhang Xiaozhi , Tan Qing , Sun Li , Pan Yu , Li Jing-Feng
Published: October 2015

Pristine and Na-doped SnSe1−xTex solid solutions exhibit reduced thermal conductivities yielding ZTmax = 0.72 with energy barrier scattering in the carrier transport.
Fully-occupied Keggin type polyoxometalate as solid base for catalyzing CO2 cycloaddition and Knoevenagel condensation
Authors: Ge Weilin , Wang Xiaochen , Zhang Lingyu , Du Lei , Zhou Yu , Wang Jun
Published: October 2015

A fully-occupied Keggin type polyoxometalate is proved to possess superior basicity and good basic activity for the first time.
Exceptional hydrogen permeation of all-ceramic composite robust membranes based on BaCe0.65Zr0.20Y0.15O3−δ and Y- or Gd-doped ceria
Authors: Rebollo Elena , Mortalò Cecilia , Escolástico Sonia , Boldrini Stefano , Barison Simona , Serra José M. , Fabrizio Monica
Published: October 2015

Mixed proton and electron conductor ceramic composites were examined as hydrogen separation membranes at moderate temperatures (higher than 500 °C).
High efficiency methylammonium lead triiodide perovskite solar cells: the relevance of non-stoichiometric precursors
Authors: Roldán-Carmona C. , Gratia P. , Zimmermann I. , Grancini G. , Gao P. , Graetzel M. , Nazeeruddin Mohammad Khaja
Published: October 2015

Improved crystallinity and device performance of CH3NH3PbI3 perovskite solar cells by using a non-stoichiometric PbI2 : CH3NH3I precursor ratio.
Correction: Changes in mangrove species assemblages and future prediction of the Bangladesh Sundarbans using Markov chain model and cellular automata
Authors: Mukhopadhyay Anirban , Mondal Parimal , Barik Jyotiskona , Chowdhury S. M. , Ghosh Tuhin , Hazra Sugata
Published: October 2015

Correction for ‘Changes in mangrove species assemblages and future prediction of the Bangladesh Sundarbans using Markov chain model and cellular automata’ by Anirban Mukhopadhyay et al., Environ. Sci.: Processes Impacts, 2015, 17, 1111–1117.
Preparation of hydrophobic reduced graphene oxide supported Ni-B-P-O and Co-B-P-O catalysts and their high hydrodeoxygenation activities
Authors: Wang Weiyan , Liu Pengli , Wu Kui , Tan Song , Li Wensong , Yang Yunquan
Published: October 2015

Hydrophobic reduced graphene oxide supported Ni-B-P-O and Co-B-P-O catalysts were beneficial to disperse in the non-polar solvent, prevent the contact with water, and consequently protected the active phases and exhibited high catalytic activity in the liquid-phase p-cresol HDO reaction.
Selective construction of junctions on different facets of BiVO4 for enhancing photo-activity
Authors: Wang Peng , Zheng Jin You , Zhang Dun , Kang Young Soo
Published: October 2015

The combination of p–n and m–s junctions over BiVO4 results in an additional effect for improving photo-activity.
Low temperature formation of rectangular PbTe nanocrystals and their thermoelectric properties
Authors: Nithiyanantham U. , Ozaydin M. Fevzi , Tazebay Abdullah S. , Kundu Subrata
Published: October 2015

A low temperature route has been demonstrated for the generation of rectangular PbTe nanocrystals within a short time which show pronounced thermoelectric behavior.
Structure and photoluminescence studies on europium- and manganese-substituted eulytite-type orthophosphate phosphors
Authors: Guo Ning , Li Shuo , Chen Jishen , Li Jing , Zhao Yuefeng , Wang Lu , Jia Chengzheng , Ouyang Ruizhuo , Lü Wei
Published: October 2015

The structure of Ba3La(PO4)3:Eu2+,Mn2+ phosphors was expressed using a split-atom model, where the oxygen atoms were distributed over two partially occupied sites.
Nanoscale electric polarizability of ultrathin biolayers on insulating substrates by electrostatic force microscopy
Authors: Dols-Perez A. , Gramse G. , Calò A. , Gomila G. , Fumagalli L.
Published: October 2015

We measured and quantified the local electric polarization properties of ultrathin (∼5 nm) biolayers on mm-thick mica substrates.
Weathering of a carbon nanotube/epoxy nanocomposite under UV light and in water bath: impact on abraded particles
Authors: Schlagenhauf Lukas , Kianfar Bahareh , Buerki-Thurnherr Tina , Kuo Yu-Ying , Wichser Adrian , Nüesch Frank , Wick Peter , Wang Jing
Published: October 2015

Weathering processes can influence the surface properties of composites with incorporated nanoparticles.
Chemiluminescence determination of human serum albumin based on Co2+-catalyzed 2-(4-tert-butylphenyl)-4,5-di(2-furyl) imidazole/H2O2system
Authors: Kang Jing , Shen Jimin , Chen Zhonglin , Nan Jun , Huang Xiao , Han Lu , Hao Weiping
Published: October 2015

Co2+could effectively enhance the sensitivity of the 2-(4-tert-butylphenyl)-4,5-di(2-furyl) imidazole/H2O2chemiluminescence reaction.
A microRNAs–mRNAs network involved in the control of graphene oxide toxicity in Caenorhabditis elegans
Authors: Zhao Yunli , Wu Qiuli , Wang Dayong
Published: October 2015

A microRNAs–mRNAs network involved in the control of graphene oxide toxicity was raised in nematodes.
Granulous KMS-1/PAN composite for Cs+ removal
Authors: Wang Yun-Xia , Li Jian-Rong , Yang Jia-Cheng E. , Yuan Baoling , Fu Ming-Lai
Published: October 2015

A novel KMS-1/PAN composite was successfully fabricated simply by combining KMS-1 with PAN. The KMS-1/PAN combines the efficient, rapid adsorption of Cs+ by KMS-1 with granulation for easy separation after adsorption.
Self-folding of polymer sheets using microwaves and graphene ink
Authors: Davis Duncan , Mailen Russell , Genzer Jan , Dickey Michael D.
Published: October 2015

Self-folding represents an attractive way to convert two-dimensional (2D) material sheets into three-dimensional (3D) objects in a hands-free manner. This paper describes a simple approach to self-fold pre-strained polystyrene (PS) sheets using microwaves.
A novel theoretical design of electronic structure and half-metallic ferromagnetism in the 3d (V)-doped rock-salts SrS, SrSe, and SrTe for spintronics
Authors: Doumi Bendouma , Mokaddem Allel , Dahmane Fethallah , Sayede Adlane , Tadjer Abdelkader
Published: October 2015

The crystal structure of a Sr1−xVxZ supercell of 16 atoms with Z = S, Se and Te and concentration x = 0.125 of V.
A facile approach to improve light induced cell sheet harvesting through nanostructure optimization
Authors: Cheng K. , Wan H. P. , Weng W. J.
Published: October 2015

In the present study, the effects of nanostructure on the light-induced cell detachment property of anatase TiO2films are investigated and discussed.
New 13-pyridinealkyl berberine analogues intercalate to DNA and induce apoptosis in HepG2 and MCF-7 cells through ROS mediated p53 dependent pathway: biophysical, biochemical and molecular modeling studies
Authors: Chatterjee Sabyasachi , Mallick Sumana , Buzzetti Franco , Fiorillo Gaetano , Syeda Tanjia Monir , Lombardi Paolo , Saha Krishna Das , Kumar Gopinatha Suresh
Published: October 2015

A new series of 13-pyridinealkyl berberine analogues was synthesized and their DNA binding efficacy studied by employing spectroscopic, calorimetric and molecular modeling techniques.
Hydrothermal and activated synthesis of adsorbent montmorillonite supported porous carbon nanospheres for removal of methylene blue from waste water
Authors: Yin Junling , Pei Meishan , He Youjun , Du Yankai , Guo Wenjuan , Wang Luyan
Published: October 2015

Novel adsorbent, montmorillonite supported porous carbon nanospheres (MMT-PCN) were conveniently synthesized by a hydrothermal carbonization and chemical activation treatment with ZnCl2.
Antihypertensive and vasorelaxant effects of Rhizoma corydalis and its active component tetrahydropalmatine via NO/cGMP pathway and calcium channel blockade in isolated rat thoracic aorta
Authors: Qu Zhuo , Zhang Jingze , Huo Liqin , Chen Hong , Li Hongfa , Fan Yaya , Gao Wenyuan
Published: October 2015

The vasorelaxant effects of RC and THPviathe NO/cGMP pathway and calcium channel blockade in isolated rat thoracic aorta are explored.
Electrospun silica-based inorganic/organic hybrid membranes with tunable performance in appropriate solvent systems
Authors: Yao Yongtao , Lu Haibao , Li Jianjun , Peng Qingyu , Wang Qun , Li Yibin , He Xiaodong , Leng Jinsong
Published: October 2015

An interesting and effective route for electrospun silica-based inorganic/organic hybrid products with tunable performance was explored successfully.
Assembly of BF4−, PF6−, ClO4− and F− with trinuclear copper(i) acetylide complexes bearing amide groups: structural diversity, photophysics and anion binding properties
Authors: Shi Hua-Yun , Huang Yong-Liang , Sun Jia-Kai , Jiang Ji-Jun , Luo Zhi-Xing , Ling Hui-Tao , Lam Chi-Keung , Chao Hsiu-Yi
Published: October 2015

Trinuclear copper(i) acetylide complexes 1·BF4–4·BF4, 1·PF6, 1·ClO4 and 4·F exhibit structural diversity with different anions and R groups on “Cu3 cluster ligands”.
Fabrication and optical sensing properties of mesoporous silica nanorod arrays
Authors: Ding Yu , Fan Yong , Zhang Yafei , He Yonghong , Sun Shuqing , Ma Hui
Published: October 2015

A mesoporous silica nanorod (MSNR) array on a gold (Au) film was fabricated and used as an optical waveguide (OWG) sensor. A resolution of the refractive index (RI) as high as 3.6 × 10−8 RIU was achieved.
Synthesis and aggregation-induced emission properties of pyridine and pyridinium analogues of tetraphenylethylene
Authors: Gabr Moustafa T. , Pigge F. Christopher
Published: October 2015

Tetraphenylethylenes in which one or two of the core phenyl rings have been replaced with pyridine or pyridinium groups have been prepared and evaluated as aggregation-induced emission fluorophores.
Reduced efficiency roll-off in phosphorescent OLEDs with a stack emitting layer facilitating triplet exciton diffusion
Authors: Yuan Shuqing , Hao Yuying , Miao Yanqin , Sun Qinjun , Li Zhanfeng , Cui Yanxia , Wang Hua , Shi Fang , Xu Bingshe
Published: October 2015

A high efficiency and low efficiency roll-off phosphorescent organic light-emitting diode (PHOLED) is demonstrated based on a stack emitting layer by alternating [CBP : 4 wt% Ir(ppy)3(5 nm)] and [CBP : 8 wt% Ir(ppy)3(5 nm)] ultrathin films.
In vitro and in vivo applications of alginate/iron oxide nanocomposites for theranostic molecular imaging in a brain tumor model
Authors: Su Chia-Hao , Cheng Fong-Yu
Published: October 2015

A novel nanocomposite composed of highly safe and US-FDA-approved Fe3O4NPs and alginate shows significant anti-brain tumor activity.
Tuning the catalytic selectivity in biomass-derived succinic acid hydrogenation on FeOx-modified Pd catalysts
Authors: Liu Xiaoran , Wang Xicheng , Xu Guoqiang , Liu Qiang , Mu Xindong , Liu Haichao
Published: October 2015

Pd–FeOx/C catalysts were prepared and found to be efficient in succinic acid hydrogenation to produce 1,4-butanediol in one-pot.
Al-coordination polymer-derived nanoporous nitrogen-doped carbon microfibers as metal-free catalysts for oxygen electroreduction and acetalization reactions
Authors: Han Zhen , Yu Youyi , Zhang Yongbo , Dong Bing , Kong Aiguo , Shan Yongkui
Published: October 2015

Nanoporous nitrogen-doped carbon microfibers were prepared by thermal conversion of Al-DTPA coordination polymers, which could be used as efficient oxygen electroreduction catalysts and to prepare porous solid acid catalysts for the acetalization reaction.
Graphene/Co9S8 nanocomposite paper as a binder-free and free-standing anode for lithium-ion batteries
Authors: Wang Huanhuan , Lu Songtao , Chen Yan , Han Lu , Zhou Jia , Wu Xiaohong , Qin Wei
Published: October 2015

A flexible and robust graphene–Co9S8 nanocomposite paper anode for high performance lithium-ion batteries.
Enhanced electrocatalytic activity of Au@Cu core@shell nanoparticles towards CO2reduction
Authors: Monzó J. , Malewski Y. , Kortlever R. , Vidal-Iglesias F. J. , Solla-Gullón J. , Koper M. T. M. , Rodriguez P.
Published: October 2015

The development of technologies for the recycling of carbon dioxide into carbon-containing fuels is one of the major challenges in sustainable energy research.
Nitrogen-enriched porous carbon nanorods templated by cellulose nanocrystals as high performance supercapacitor electrodes
Authors: Wu Xinyun , Shi Zengqian , Tjandra Ricky , Cousins Aleisha Justine , Sy Serubbabel , Yu Aiping , Berry Richard M. , Tam Kam C.
Published: October 2015

Cellulose nanocrystal-templated melamine-formaldehyde nanorods were fabricated via in situ polycondensation followed by a one-step carbonization into hierarchically porous carbon that possessed promising supercapacitive performance.
Numerical simulations of bijel morphology in thin films with complete surface wetting
Authors: Carmack Joseph M. , Millett Paul C.
Published: October 2015

Bijels are a relatively new class of soft materials that have many potential energy and environmental applications. In this work, simulation results of bijel evolution confined within thin films with preferential surface wetting are presented. The computational approach used is a hybrid Cahn-Hilliard/Brownian dynamics method. In the absence of suspended particles, we demonstrate that the model accurately captures the rich kinetics associated with diffusion-based surface-directed spinodal decomposition, as evidenced by comparison with previous theoretical and simulation-based studies. When chemically neutral particles are included in the films, the simulations capture surface-modified bijel formation, with stabilized domain structures comparable with the experimental observations of Composto and coworkers. Namely, two basic morphologies — bicontinuous or discrete — are seen to emerge, with direct dependence on the film thickness, particle volume fraction, and particle radius.
Electron-beam driven relaxation oscillations in ferroelectric nanodisks
Authors: Ng Nathaniel , Ahluwalia Rajeev , Kumar Ashok , Srolovitz David J. , Chandra Premala , Scott James F.
Published: October 2015

Using a combination of computational simulations, atomic-scale resolution imaging and phenomenological modelling, we examine the underlying mechanism for nanodomain restructuring in lead zirconate titanate nanodisks driven by electron beams. The observed subhertz nanodomain dynamics are identified with relaxation oscillations where the charging/discharging cycle time is determined by saturation of charge traps and nanodomain wall creep. These results are unusual in that they indicate very slow athermal dynamics in nanoscale systems, and possible applications of gated versions are discussed.
Fluctuations of local electric field and dipole moments in water between metal walls
Authors: Takae Kyohei , Onuki Akira
Published: October 2015

We examine the thermal fluctuations of the local electric field Ekloc and the dipole moment μk in liquid water at T = 298 K between metal walls in electric field applied in the perpendicular direction. We use analytic theory and molecular dynamics simulation. In this situation, there is a global electrostatic coupling between the surface charges on the walls and the polarization in the bulk. Then, the correlation function of the polarization density pz(r) along the applied field contains a homogeneous part inversely proportional to the cell volume V. Accounting for the long-range dipolar interaction, we derive the Kirkwood-Fröhlich formula for the polarization fluctuations when the specimen volume v is much smaller than V. However, for not small v/V, the homogeneous part comes into play in dielectric relations. We also calculate the distribution of Ekloc in applied field. As a unique feature of water, its magnitude |Ekloc| obeys a Gaussian distribution with a large mean value E0 ≅ 17 V/nm, which arises mainly from the surrounding hydrogen-bonded molecules. Since |μk|E0 ∼ 30kBT, μk becomes mostly parallel to Ekloc. As a result, the orientation distributions of these two vectors nearly coincide, assuming the classical exponential form. In dynamics, the component of μk(t) parallel to Ekloc(t) changes on the time scale of the hydrogen bonds ∼5 ps, while its smaller perpendicular component undergoes librational motions on time scales of 0.01 ps.
Symmetry of extremely floppy molecules: Molecular states beyond rotation-vibration separation
Authors: Schmiedt Hanno , Schlemmer Stephan , Jensen Per
Published: October 2015

Traditionally, molecules are theoretically described as near-static structures rotating in space. Vibrational motion causing small structural deformations induces a perturbative treatment of the rotation-vibration interaction, which fails in highly fluxional molecules, where all vibrational motions have amplitudes comparable in size to the linear dimensions of the molecule. An example is protonated methane (CH5+) [P. Kumar and D. Marx, Phys. Chem. Chem. Phys. 8, 573 (2006); Z. Jin et al., J. Phys. Chem. A 110, 1569 (2006); and A. S. Petit et al., J. Phys. Chem. A 118, 7206 (2014)]. For these molecules, customary theory fails to simulate reliably even the low-energy spectrum [T. Oka, Science 347, 1313–1314 (2015) and O. Asvany et al., Science 347, 1346–1349 (2015)]. Within the traditional view of rotation and vibration being near-separable, rotational and vibrational wavefunctions can be symmetry classified separately in the molecular symmetry (MS) group [P. Bunker and P. Jensen, Molecular Symmetry and Spectroscopy, NRC Monograph Publishing Program (NRC Research Press, 2006)]. In this article, we discuss a fundamental group theoretical approach to the problem of determining the symmetries of molecular rotation-vibration states. We will show that all MS groups discussed so far are isomorphic to subgroups of the special orthogonal group in three dimensions SO(3). This leads to a group theoretical foundation of the technique of equivalent rotations [H. Longuet-Higgins, Mol. Phys. 6, 445 (1963)]. The group G240 (the MS group of protonated methane) represents, to the best of our knowledge, the first example of a MS group which is not isomorphic to a subgroup of SO(3) (nor of O(3) or of SU(2)). Because of this, a separate symmetry classification of vibrational and rotational wavefunctions becomes impossible in this MS group, consistent with the fact that a decoupling of vibrational and rotational motion is impossible. We discuss here the consequences of this. In conclusion, we show that the prototypical, extremely floppy molecule CH5+ represents a new class of molecules, where customary group theoretical methods for determining selection rules and spectral assignments fail so that new methods have to be developed.
The transition mechanisms of the E to H mode and the H to E mode in an inductively coupled argon-mercury mixture discharge
Authors: Zhang Xiao , Yu Peng-Cheng , Liu Yu , Zheng Zhe , Xu Liang , Wang Pi , Cao Jin-Xiang
Published: October 2015

In our experiment, the transition points between the two operational modes of capacitive coupling (E mode) and inductive coupling (H mode) were investigated at a wide range of mercury vapor pressures in an inductively coupled plasma, varying with the input radio-frequency powers and the total filling pressures (10 Pa–30 Pa). The electron temperatures were calculated versus with the mercury vapor pressures for different values of the total filling pressures. The transition power points and electron density also were measured in this study. It is shown that the transition powers, whether the E to H mode transition or the H to E mode transition, are lower than that of the argon discharge, and these powers almost increase with the mercury vapor pressure rising. However, the transition electron density follows an inverse relationship with the mercury vapor pressures compared with the transition powers. In addition, at the lower pressures and higher mercury vapor pressures, an inverse hysteresis was observed clearly, which did not appear in the argon gas plasma. We suggest that all these results are attributed to the electron-neutral collision frequency changed with the additional mercury vapor pressures.
Bump-on-tail instability in space plasmas
Authors: Sarkar Susmita , Paul Samit , Denra Raicharan
Published: October 2015

Bump-on-tail instability of Langmuir waves propagating in unmagnetized Lorentzian plasma modeled by a Kappa velocity distribution with spectral index κ has been investigated in this paper. Growth rate of this microinstability has been determined analytically from the Langmuir wave dispersion relation. Change in the maximum growth rate with increasing κ has been numerically estimated for different number density and temperature ratios using solar wind data.
Interference in multilayer relativistic mirrors
Authors: Mirzanejhad Saeed , Sohbatzadeh Farshad , Babaei Javad , Taghipour Meisam , Mohammadzadeh Zahra
Published: October 2015

In this paper, reflection coefficient of a relativistic ultra-thin electron multilayer is calculated using electromagnetic interference procedures. The relativistic electron layers are assumed to be formed by nonlinear plasma wake waves that constitute the electron density cusps. It is shown that the interference between successive relativistic mirrors is restricted by the condition, τp≫(2γ0)5/2/ωp0, where τp is the laser pulse duration. The results showed that tailoring the pulse amplitude, incident wave frequency value, incidence angle, and plasma density leads to increasing reflection coefficient a few orders of magnitudes. This constructive interference condition can be used for increasing conversion efficiency in the reflected energy from relativistic mirrors for the purpose of generating ultra-short coherence pulses in the extreme ultraviolet and x-ray regions. We also performed reflection from relativistic thin electron layers using relativistic 1D3V electromagnetic particle-in-cell (PIC) simulation. It was found that the results of PIC simulation are in agreement with analytical considerations.
Turbulent boundary layer over 2D and 3D large-scale wavy walls
Authors: Hamed Ali M. , Kamdar Arpeet , Castillo Luciano , Chamorro Leonardo P.
Published: October 2015

An experimental investigation of the flow over two- and three-dimensional large-scale wavy walls was performed using high-resolution planar particle image velocimetry in a refractive-index-matching (RIM) channel. The 2D wall is described by a sinusoidal wave in the streamwise direction with amplitude to wavelength ratio a/λx = 0.05. The 3D wall is defined with an additional wave superimposed on the 2D wall in the spanwise direction with a/λy = 0.1. The flow over these walls was characterized at Reynolds numbers of 4000 and 40 000, based on the bulk velocity and the channel half height. Flow measurements were performed in a wall-normal plane for the two cases and in wall-parallel planes at three heights for the 3D wavy wall. Instantaneous velocity fields and time-averaged turbulence quantities reveal strong coupling between large-scale topography and the turbulence dynamics near the wall. Turbulence statistics show the presence of a well-structured shear layer that enhances the turbulence for the 2D wavy wall, whereas the 3D wall exhibits different flow dynamics and significantly lower turbulence levels. It is shown that the 3D surface limits the dynamics of the spanwise turbulent vortical structures, leading to reduced turbulence production and turbulent stresses and, consequently, lower average drag (wall shear stress). The likelihood of recirculation bubbles, levels and spatial distribution of turbulence, and rate of the turbulent kinetic energy production are shown to be severely affected when a single spanwise mode is superimposed on the 2D sinusoidal wall. Differences of one and two order of magnitudes are found in the turbulence levels and Reynolds shear stress at the low Reynolds number for the 2D and 3D cases. These results highlight the sensitivity of the flow to large-scale topographic modulations; in particular the levels and production of turbulent kinetic energy as well as the wall shear stress.
Peculiarities of high-overtone transition probabilities in carbon monoxide revealed by high-precision calculation
Authors: Medvedev Emile S. , Meshkov Vladimir V. , Stolyarov Andrey V. , Gordon Iouli E.
Published: October 2015

In the recent work devoted to the calculation of the rovibrational line list of the CO molecule [G. Li et al., Astrophys. J., Suppl. Ser. 216, 15 (2015)], rigorous validation of the calculated parameters including intensities was carried out. In particular, the Normal Intensity Distribution Law (NIDL) [E. S. Medvedev, J. Chem. Phys. 137, 174307 (2012)] was employed for the validation purposes, and it was found that, in the original CO line list calculated for large changes of the vibrational quantum number up to Δn = 41, intensities with Δn > 11 were unphysical. Therefore, very high overtone transitions were removed from the published list in Li et al. Here, we show how this type of validation is carried out and prove that the quadruple precision is indispensably required to predict the reliable intensities using the conventional 32-bit computers. Based on these calculations, the NIDL is shown to hold up for the 0 → n transitions till the dissociation limit around n = 83, covering 45 orders of magnitude in the intensity. The low-intensity 0 → n transition predicted in the work of Medvedev [Determination of a new molecular constant for diatomic systems. Normal intensity distribution law for overtone spectra of diatomic and polyatomic molecules and anomalies in overtone absorption spectra of diatomic molecules, Institute of Chemical Physics, Russian Academy of Sciences, Chernogolovka, 1984] at n = 5 is confirmed, and two additional “abnormal” intensities are found at n = 14 and 23. Criteria for the appearance of such “anomalies” are formulated. The results could be useful to revise the high-overtone molecular transition probabilities provided in spectroscopic databases.
Broadband control of emission wavelength of InAs/GaAs quantum dots by GaAs capping temperature
Authors: Kaizu Toshiyuki , Matsumura Takuya , Kita Takashi
Published: October 2015

We investigated the effects of the GaAs capping temperature on the morphological and photoluminescence (PL) properties of InAs quantum dots (QDs) on GaAs(001). The broadband tuning of the emission wavelength from 1.1 to 1.3 μm was achieved at room temperature by only adjusting the GaAs capping temperature. As the capping temperature was decreased, the QD shrinkage due to In desorption and In-Ga intermixing during the capping process was suppressed. This led to QDs with a high aspect ratio, and resultantly, the emission wavelength shifted toward the longer-wavelength side. In addition, the linearly polarized PL intensity elucidated anisotropic characteristics reflecting the shape anisotropy of the embedded QDs, in which a marked change in polarization anisotropy occurred at capping temperatures lower than 460 °C.
Pump-probe Kelvin-probe force microscopy: Principle of operation and resolution limits
Authors: Murawski J. , Graupner T. , Milde P. , Raupach R. , Zerweck-Trogisch U. , Eng L. M.
Published: October 2015

Knowledge on surface potential dynamics is crucial for understanding the performance of modern-type nanoscale devices. We describe an electrical pump-probe approach in Kelvin-probe force microscopy that enables a quantitative measurement of dynamic surface potentials at nanosecond-time and nanometer-length scales. Also, we investigate the performance of pump-probe Kelvin-probe force microscopy with respect to the relevant experimental parameters. We exemplify a measurement on an organic field effect transistor that verifies the undisturbed functionality of our pump-probe approach in terms of simultaneous and quantitative mapping of topographic and electronic information at a high lateral and temporal resolution.
Communication: Surface stability and topological surface states of cleaved Bi2Se3: First-principles studies
Authors: Zhang Y. N.
Published: October 2015

Through systematic first principles calculations within the nonlocal van der Waals functional, we investigated the structure stability and topological surface state properties of various surface cleaves in the topological insulator Bi2Se3 Our results reveal that under Bi-rich conditions, the Bi bilayer-covered surface and the Se-terminated surface with a Bi bilayer under the first quintuple layer are even more stable than the generic Bi2Se3. The surface state bands are changed by different surface terminations, causing the formation of new Dirac states. We may distinguish various surfaces by using scanning tunneling microscopy experimentally.