bluuebunny/crossref_metadata_2025 huggingface dataset:
TbIRK is a signature sequence free potassium channel from Trypanosoma brucei locating to acidocalcisomes
Authors: Steinmann Michael E. , Schmidt Remo S. , Bütikofer Peter , Mäser Pascal , Sigel Erwin
Published: March 2017

Potassium channels from prokaryotes and eukaryotes are usually recognized by a typical amino acid sequence TXTGY(F)G representing the ionic selectivity filter. Using a screening approach with ion channel family profiles but without the above motif, we identified a gene in Trypanosoma brucei that exhibits homology to inward rectifying potassium channels. We report here cloning of this ion channel named TbIRK. The protein is localized to acidocalcisomes in procyclic and in bloodstream form parasites. Functional properties of this channel were established after expression in Xenopus oocytes. Currents recorded in potassium medium show inward rectification and little time dependence. Surprisingly, this channel retains selectivity for potassium ions over sodium ions >7, in spite of the lack of the classical selectivity filter. The sequence GGYVG was predicted in silico to replace this filter motif. Point mutations of the corresponding glycine residues confirmed this at the functional level. The channel is inhibited by caesium ions but remains unaffected by barium ions up to 10 mM. TbIRK is to our knowledge the first potassium channel in T. brucei that localizes to the acidocalcisomes, organelles involved in the storage of phosphates and the response to osmotic stress that occurs during the life cycle of trypanosomes.
Case-control analysis of truncating mutations in DNA damage response genes connects TEX15 and FANCD2 with hereditary breast cancer susceptibility
Authors: Mantere Tuomo , Tervasmäki Anna , Nurmi Anna , Rapakko Katrin , Kauppila Saila , Tang Jiangbo , Schleutker Johanna , Kallioniemi Anne , Hartikainen Jaana M. , Mannermaa Arto , Nieminen Pentti , Hanhisalo Riitta , Lehto Sini , Suvanto Maija , Grip Mervi , Jukkola-Vuorinen Arja , Tengström Maria , Auvinen Päivi , Kvist Anders , Borg Åke , Blomqvist Carl , Aittomäki Kristiina , Greenberg Roger A. , Winqvist Robert , Nevanlinna Heli , Pylkäs Katri
Published: March 2017

Several known breast cancer susceptibility genes encode proteins involved in DNA damage response (DDR) and are characterized by rare loss-of-function mutations. However, these explain less than half of the familial cases. To identify novel susceptibility factors, 39 rare truncating mutations, identified in 189 Northern Finnish hereditary breast cancer patients in parallel sequencing of 796 DDR genes, were studied for disease association. Mutation screening was performed for Northern Finnish breast cancer cases (n = 578–1565) and controls (n = 337–1228). Mutations showing potential cancer association were analyzed in additional Finnish cohorts. c.7253dupT in TEX15, encoding a DDR factor important in meiosis, associated with hereditary breast cancer (p = 0.018) and likely represents a Northern Finnish founder mutation. A deleterious c.2715 + 1G > A mutation in the Fanconi anemia gene, FANCD2, was over two times more common in the combined Finnish hereditary cohort compared to controls. A deletion (c.640_644del5) in RNF168, causative for recessive RIDDLE syndrome, had high prevalence in majority of the analyzed cohorts, but did not associate with breast cancer. In conclusion, truncating variants in TEX15 and FANCD2 are potential breast cancer risk factors, warranting further investigations in other populations. Furthermore, high frequency of RNF168 c.640_644del5 indicates the need for its testing in Finnish patients with RIDDLE syndrome symptoms.
Higher dietary intakes of choline and betaine are associated with a lower risk of primary liver cancer: a case-control study
Authors: Zhou Rui-fen , Chen Xiao-Lin , Zhou Zhong-guo , Zhang Yao-jun , Lan Qiu-ye , Liao Gong-cheng , Chen Yu-ming , Zhu Hui-lian
Published: March 2017

The dietary intake of methyl donors is favorably associated with many diseases, but the findings regarding primary liver cancer (PLC) risk are limited. This study investigated the association between the intake of choline, betaine and methionine and PLC risk in adults. This 1:1 matched case-control study enrolled 644 hospital-based PLC patients and 644 community-based controls who were matched by sex and age, in Guangzhou, China. An interviewer-administered questionnaire and a food-frequency questionnaire were used to collect general information and dietary intake information. Conditional logistic regression showed a significantly inverse association between total choline and betaine intakes and PLC risk. The multivariable-adjusted odds ratios (ORs) and their 95% confidence intervals (CIs) for PLC for the top (vs. bottom) tertile were 0.34 (0.24–0.49; P
-trend < 0.001) for total choline and 0.67 (0.48–0.93; P
-trend = 0.011) for betaine. No significant association was observed between the intake of methionine and PLC risk (P > 0.05). For individual choline compounds, higher consumptions of free choline, glycerophosphocholine, phosphocholine, phosphatidylcholine and sphingomyelin were associated with a lower PLC risk (all P-trend < 0.05). The studied associations were not significantly modified by the folate intake (P-interactions: 0.488–0.890). Our findings suggest that higher choline and betaine intakes may be associated with a lower risk of PLC.
Hybrid Organic-Inorganic Perovskite Memory with Long-Term Stability in Air
Authors: Hwang Bohee , Lee Jang-Sik
Published: March 2017

Organic-inorganic perovskite materials have attracted extensive attention for wide range of applications such as solar cells, photo detectors, and memory devices. However, the lack of stability in ambient condition prevented the perovskite materials from applying to practical applications. Here, we demonstrate resistive switching memory devices based on organic-inorganic perovskite (CH3NH3PbI3) that have been passivated using thin metal-oxide-layers. CH3NH3PbI3-based memory devices with a solution-processed ZnO passivation layer retain low-voltage operation and, on/off current ratio for more than 30 days in air. Passivation with atomic-layer-deposited (ALD) AlOx is also demonstrated. The resistive switching memory devices with an ALD AlOx passivation layer maintained reliable resistive switching for 30 d in ambient condition, but devices without the passivation layer degraded rapidly and did not show memory properties after 3 d. These results suggest that encapsulation with thin metal-oxide layers is easy and commercially-viable methods to fabricate practical memory devices, and has potential to realize memory devices with long-term stability and reliable, reproducible programmable memory characteristics.
Clean, cleaved surfaces of the photovoltaic perovskite
Authors: Kollár Márton , Ćirić Luka , Dil J. Hugo , Weber Andrew , Muff Stefan , Ronnow Henrik M. , Náfrádi Bálint , Monnier Benjamin Pierre , Luterbacher Jeremy Scott , Forró László , Horváth Endre
Published: March 2017

The surface of a material is not only a window into its bulk physical properties, but also hosts unique phenomena important for understanding the properties of a solid as a whole. Surface sensitive techniques, like ARPES (Angle-resolved photoemission spectroscopy), STM (Scanning tunneling microscopy), AFM (Atomic force microscopy), pump-probe optical measurements etc. require flat, clean surfaces. These can be obtained by cleaving, which is usually possible for layered materials. Such measurements have proven their worth by providing valuable information about cuprate superconductors, graphene, transition metal dichalcogenides, topological insulators and many other novel materials. Unfortunately, this was so far not the case for the cubic, organo-metallic photovoltaic perovskite which morsels during the cleavage. Here we show a method which results in flat, clean surfaces of CH3NH3PbBr3 which allows surface sensitive measurements, badly needed for the understanding and further engineering of this material family.
Leucovorin Enhances the Anti-cancer Effect of Bortezomib in Colorectal Cancer Cells
Authors: Wang Shu , Wang Lei , Zhou Zhiyang , Deng Qipan , Li Ling , Zhang Mingzhi , Liu Linlin , Li Yong
Published: March 2017

Colorectal cancer is a major cancer type worldwide. 5-fluorouracil, often given with leucovorin, is the most commonly used drug in colorectal cancer chemotherapy, yet development of drug resistance to 5-fluorouracil in colorectal cancer cells is the primary cause of chemotherapy failure. Most patients receiving intravenous 5-fluorouracil develop side effects. Leucovorin, due to its vitamin-like profile, has few side-effects. Drug repurposing is the application of approved drugs to treat new indications. In this study, we performed a novel drug-repurposing screening to identify Food and Drug Administration-approved chemotherapeutic compounds possessing synergistic activity with leucovorin against colorectal cancer cells. We found that the combination of bortezomib and leucovorin enhanced caspase activation and increased apoptosis in colorectal cancer cells better than either agent alone. Further, the synergistic induction of apoptosis and inhibition of tumor growth were also observed in mouse colorectal cancer xenografts. These data support leucovorin enhances the anti-cancer effect of bortezomib and present this novel combinatorial treatment against colorectal cancer.
Pavlovian conditioning demonstrated with neuromorphic memristive devices
Authors: Tan Zheng-Hua , Yin Xue-Bing , Yang Rui , Mi Shao-Bo , Jia Chun-Lin , Guo Xin
Published: March 2017

Pavlovian conditioning, a classical case of associative learning in a biological brain, is demonstrated using the Ni/Nb-SrTiO3/Ti memristive device with intrinsic forgetting properties in the framework of the asymmetric spike-timing-dependent plasticity of synapses. Three basic features of the Pavlovian conditioning, namely, acquisition, extinction and recovery, are implemented in detail. The effects of the temporal relation between conditioned and unconditioned stimuli as well as the time interval between individual training trials on the Pavlovian conditioning are investigated. The resulting change of the response strength, the number of training trials necessary for acquisition and the number of extinction trials are illustrated. This work clearly demonstrates the hardware implementation of the brain function of the associative learning.
Soft and wrinkled carbon membranes derived from petals for flexible supercapacitors
Authors: Yu Xiuxiu , Wang Ying , Li Li , Li Hongbian , Shang Yuanyuan
Published: March 2017

Biomass materials are promising precursors for the production of carbonaceous materials due to their abundance, low cost and renewability. Here, a freestanding wrinkled carbon membrane (WCM) electrode material for flexible supercapacitors (SCs) was obtained from flower petal. The carbon membrane was fabricated by a simple thermal pyrolysis process and further activated by heating the sample in air. As a binder and current collector-free electrode, the activated wrinkled carbon membrane (AWCM) exhibited a high specific capacitance of 332.7 F/g and excellent cycling performance with 92.3% capacitance retention over 10000 cycles. Moreover, a flexible all-solid supercapacitor with AWCM electrode was fabricated and showed a maximum specific capacitance of 154 F/g and great bending stability. The development of this flower petal based carbon membrane provides a promising cost-effective and environmental benign electrode material for flexible energy storage.
Parental Exposure to Dim Light at Night Prior to Mating Alters Offspring Adaptive Immunity
Authors: Cissé Yasmine M. , Russart Kathryn L.G. , Nelson Randy J.
Published: March 2017

Exposure to dim light at night (dLAN) disrupts natural light/dark cycles and impairs endogenous circadian rhythms necessary to maintain optimal biological function, including the endocrine and immune systems. We have previously demonstrated that white dLAN compromises innate and cell mediated immune responses in adult Siberian hamsters (Phodopus sungorus). We hypothesized that dLAN has transgenerational influences on immune function. Adult male and female Siberian hamsters were exposed to either dark nights (DARK) or dLAN (~5 lux) for 9 weeks, then paired in full factorial design, mated, and thereafter housed under dark nights. Offspring were gestated and reared in dark nights, then tested as adults for cell-mediated and humoral immunity. Maternal exposure to dLAN dampened delayed type hypersensitivity (DTH) responses in male offspring. Maternal and paternal exposure to dLAN reduced DTH responses in female offspring. IgG antibodies to a novel antigen were elevated in offspring of dams exposed to dLAN. Paternal exposure to dLAN decreased splenic endocrine receptor expression and global methylation in a parental sex-specific manner. Together, these data suggest that exposure to dLAN has transgenerational effects on endocrine-immune function that may be mediated by global alterations in the epigenetic landscape of immune tissues.
IgE binds asymmetrically to its B cell receptor CD23
Authors: Dhaliwal Balvinder , Pang Marie O. Y. , Keeble Anthony H. , James Louisa K. , Gould Hannah J. , McDonnell James M. , Sutton Brian J. , Beavil Andrew J.
Published: March 2017

The antibody IgE plays a central role in allergic disease mechanisms. Its effector functions are controlled through interactions between the Fc region and two principal cell surface receptors FcεRI and CD23. The interaction with FcεRI is primarily responsible for allergic sensitization and the inflammatory response, while IgE binding to CD23 is involved in the regulation of IgE synthesis and allergen transcytosis. Here we present the crystal structure of a CD23/IgE-Fc complex and conduct isothermal titration calorimetric binding studies. Two lectin-like “head” domains of CD23 bind to IgE-Fc with affinities that differ by more than an order of magnitude, but the crystal structure reveals only one head bound to one of the two identical heavy-chains in the asymmetrically bent IgE-Fc. These results highlight the subtle interplay between receptor binding sites in IgE-Fc and their affinities, the understanding of which may be exploited for therapeutic intervention in allergic disease.
Rational mutagenesis by engineering disulphide bonds improves Kluyveromyces lactis beta-galactosidase for high-temperature industrial applications
Authors: Rico-Díaz Agustín , Álvarez-Cao María-Efigenia , Escuder-Rodríguez Juan-José , González-Siso María-Isabel , Cerdán M. Esperanza , Becerra Manuel
Published: March 2017

Kluyveromyces lactis β-galactosidase (Kl-β-Gal) is one of the most important enzymes in the dairy industry. The poor stability of this enzyme limits its use in the synthesis of galactooligosaccharides (GOS) and other applications requiring high operational temperature. To obtain thermoresistant variants, a rational mutagenesis strategy by introducing disulphide bonds in the interface between the enzyme subunits was used. Two improved mutants, R116C/T270C and R116C/T270C/G818C, had increased half-lives at 45 °C compared to Kl-β-Gal (2.2 and 6.8 fold increases, respectively). Likewise, Tm values of R116C/T270C and R116C/T270C/G818C were 2.4 and 8.5 °C, respectively, higher than Kl-β-Gal Tm. Enrichment in enzymatically active oligomeric forms in these mutant variants also increased their catalytic efficiency, due to the reinforcement of the interface contacts. In this way, using an artificial substrate (p-nitrophenyl-β-D-galactopyranoside), the Vmax values of the mutants were ~1.4 (R116C/T270C) and 2 (R116C/T270C/G818C) fold higher than that of native Kl-β-Gal. Using the natural substrate (lactose) the Vmax for R116C/T270C/G818C almost doubled the Vmax for Kl-β-Gal. Validation of these mutant variants of the enzyme for their use in applications that depend on prolonged incubations at high temperatures was achieved at the laboratory scale by monitoring their catalytic activity in GOS synthesis.
Zinc treatment is efficient against Escherichia coli α-haemolysin-induced intestinal leakage in mice
Authors: Wiegand Stephanie , Zakrzewski Silke S. , Eichner Miriam , Schulz Emanuel , Günzel Dorothee , Pieper Robert , Rosenthal Rita , Barmeyer Christian , Bleich André , Dobrindt Ulrich , Schulzke Jörg-Dieter , Bücker Roland
Published: March 2017

Zinc homoeostasis exerts protective effects in inflammatory intestinal diseases and zinc supplementation has been successfully used for treating infectious diarrhoea. This study aimed at a characterisation of zinc effects on focal leak induction by α-haemolysin (HlyA)-producing Escherichia coli (E. coli) as protective mechanism for colitis. We conducted in vivo experiments by oral challenge of gnotobiotic mice colonised with HlyA-expressing E. coli-536. Mice were either fed a defined normal or high zinc diet to analyse effects of zinc as a therapeutic regimen. HlyA-deficient E. coli-536 mutants were used as controls. Mice infected with HlyA-producing E. coli showed impaired barrier integrity when receiving normal zinc. High zinc supplementation in HlyA-producing E. coli-infected mice reduced epithelial dysfunction as indicated by ameliorated macromolecule permeability. Reduced size of focal leaks with diminished bacterial translocation was observed as inherent mechanisms of this zinc action. In human colon cell monolayers application of zinc rescued the HlyA-dependent decline in transepithelial electrical resistance via reduction of the calcium entry into HlyA-exposed cells. Calcium-dependent cell exfoliation was identified as mechanism for focal leak induction. In conclusion, zinc supplementation protects from HlyA-induced barrier dysfunction in vivo and in vitro, providing an explanation for the protective efficacy of zinc in intestinal disorders.
Land cover changes induced by the great east Japan earthquake in 2011
Authors: Ishihara Mitsunori , Tadono Takeo
Published: March 2017

The east Japan earthquake that occurred on March 11, 2011 was a big natural disaster, comprising the large earthquake shock, tsunami, and Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. These disasters caused changes in the land use and land cover (LULC) in Japan’s Tohoku district. While the LULC map created before the disaster is available, as yet there is no precise LULC map of the district after the disaster. In this study, we created a precise LULC map for the years 2013–2015 post-disaster with 30-m spatial resolution using the Landsat-8 with the Operational Land Imager (OLI) to evaluate the changes in LULC induced by the disaster. Our results indicate many changes in areas categorized as rice paddies primarily into grass categories along the coast damaged by the tsunami and in the evacuation zone around the FDNPP. Since there is a possibility of future LULC changes according to the change of the evacuation zone and implementation of reconstruction and revitalization efforts, we recommend continual monitoring of the changes in LULC by the use of satellite data in order to evaluate the long-term effects of the disaster.
Advances in the synthesis of acyclic peroxides
Authors: Gandhi H. , O'Reilly K. , Gupta M. K. , Horgan C. , O'Leary E. M. , O'Sullivan T. P.
Published: March 2017

This review summarises the many developments in the synthesis of acyclic peroxides, with a particular focus on the past 20 years, and seeks to update organic chemists about these new approaches.
Simultaneous engineering of an enzyme's entrance tunnel and active site: the case of monoamine oxidase MAO-N
Authors: Li Guangyue , Yao Peiyuan , Gong Rui , Li Jinlong , Liu Pi , Lonsdale Richard , Wu Qiaqing , Lin Jianping , Zhu Dunming , Reetz Manfred T.
Published: March 2017

An efficient directed evolution strategy for enhancing activity and manipulating stereoselectivity of a monoamine oxidase is presented.
Controlling transmembrane protein concentration and orientation in supported lipid bilayers
Authors: Bao P. , Cartron M. L. , Sheikh K. H. , Johnson B. R. G. , Hunter C. N. , Evans S. D.
Published: March 2017

The trans-membrane protein–proteorhodopsin (pR) has been incorporated into supported lipid bilayers (SLB). In-plane electric fields have been used to manipulate the orientation and concentration of these proteins, within the SLB, through electrophoresis leading to a 25-fold increase concentration of pR.
Interactions regulating the head-to-tail directed assembly of biological Janus rods
Authors: Greene A. C. , Bachand M. , Gomez A. , Stevens M. J. , Bachand G. D.
Published: March 2017

We show that the directed assembly of microtubule filaments is governed by a careful balance of long- and short-range interactions.
Kinetic resolution via supramolecular iminium catalysis: multiactivation enables the asymmetric synthesis of β-aryl substituted aldehydes and densely functionalized cyclohexanes
Authors: Jia Zhi-Long , Wang Yao , Xu Guo-Qiang , Xu Peng-Fei
Published: March 2017

A kinetic resolution affording enantioenriched β-aryl substituted aldehydes and densely functionalized cyclohexanes has been accomplished using a supramolecular iminium catalysis strategy.
High-quality Janus nanofibers prepared using three-fluid electrospinning
Authors: Yu Deng-Guang , Li Jiao-Jiao , Zhang Man , Williams Gareth R.
Published: March 2017

A new structured spinneret has been developed; this permits the fabrication of high quality Janus nanofibers using a three-fluid electrospinning process.
Visible-light-mediated radical insertion/cyclization cascade reaction: synthesis of phenanthridines and isoquinolines from isocyanides
Authors: Feng Shangbiao , Li Tao , Du Chenglong , Chen Peng , Song Dengpeng , Li Jinlai , Xie Xingang , She Xuegong
Published: March 2017

The development of a visible-light promoted radical insertion/cyclization cascade reaction to generate phenanthridines and isoquinolines from isocyanides under mild reaction conditions is reported.
Highly selective CO2vs. N2 adsorption in the cavity of a molecular coordination cage
Authors: Wright James S. , Metherell Alexander J. , Cullen William M. , Piper Jerico R. , Dawson Robert , Ward Michael D.
Published: March 2017

A cubic coordination cage shows high selectivity for CO2vs. N2 uptake in the cage cavity, despite the bulk material being non-porous.
Benz-amidinato calcium iodide catalyzed aldehyde and ketone hydroboration with unprecedented functional group tolerance
Authors: Yadav Sandeep , Pahar Sanjukta , Sen Sakya S.
Published: March 2017

A benz-amidinato calcium compound, [PhC(NiPr)2CaI] (1) catalyzed hydroboration of a wide range of aldehydes and ketones using pinacolborane (HBpin) at room temperature is reported.
Interrelationship between TiO2 nanoparticle size and kind/size of dyes in the mechanism and conversion efficiency of dye sensitized solar cells
Authors: Tahay Pooya , Babapour Gol Afshani Meisam , Alavi Ali , Parsa Zahra , Safari Nasser
Published: March 2017

Photocurrent efficiency measurements and other experimental results demonstrate that the best TiO2 nanoparticle size depends on the intrinsic properties of the dye and the best size changes with dye type.
Structural control of side-chain chromophores to achieve highly efficient electro-optic activity
Authors: Yang Yuhui , Chen Zhuo , Liu Jialei , Xiao Hongyan , Zhen Zhen , Liu Xinhou , Jiang Guohua
Published: March 2017

Chromophore J2 in APC provided the best balance between steric hindrance and molecular free mobility with excellent electro-optic coefficients.
Environmental photochemistry of fenamate NSAIDs and their radical intermediates
Authors: Davis Caroline A. , Erickson Paul R. , McNeill Kristopher , Janssen Elisabeth M. L.
Published: March 2017

Photodegradation of five NSAIDs was studied by steady-state and laser-flash photolysis quantifying reaction pathways and kinetics via electron transfer mechanisms.
Rational use and reuse of Nafion 212 membrane in vanadium flow batteries
Authors: Zhou Ying , Yu Lihong , Wang Jianshe , Liu Le , Liang Feng , Xi Jingyu
Published: March 2017

A rational use of Nafion membrane can achieve superior VFB performance, and Nafion membrane can be reused in VFB.
Plasma-deposited hydrogenated amorphous silicon films: multiscale modelling reveals key processes
Authors: Marvi Z. , Xu S. , Foroutan G. , Ostrikov K. , Levchenko I.
Published: March 2017

Physical and chemical mechanisms and role of plasma in the synthesis of hydrogenated amorphous silicon were studied numerically to reveal the key growth processes and, hence, to ensure a higher level of control over the film structure and properties.
Matrix isolation study of the early intermediates in the ozonolysis of selected vinyl ethers
Authors: Lv Chen , Du Lin , Tang Shanshan , Tsona Narcisse T. , Liu Shijie , Zhao Hailiang , Wang Wenxing
Published: March 2017

The Criegee mechanism of the ozonolysis reaction of vinyl ethers has been observed by matrix isolation FTIR spectroscopy.
Challenging cyclopropanation reactions on non-activated double bonds of fatty esters
Authors: Angulo B. , Fraile J. M. , Herrerías C. I. , Mayoral J. A.
Published: March 2017

Cyclopropanation reactions in the chain of unsaturated fatty esters is a good strategy for the ready preparation of potential monomers for polymerization.
Study on the performance of micro-flow injection preconcentration method on-line coupled to thermospray flame furnace AAS using MWCNTs wrapped with polyvinylpyridine nanocomposites as adsorbent
Authors: Tarley César Ricardo Teixeira , Diniz Kristiany Moreira , Cajamarca Suquila Fabio Antonio , Segatelli Mariana Gava
Published: March 2017

An adsorbent nanocomposite based on multi-walled carbon nanotubes and polyvinylpyridine is used in the development of a micro-flow injection preconcentration method coupled to TS-FF-AAS for the determination of very low levels of Cd.
Chitosan microspheres as a template for TiO2and ZnO microparticles: studies on mechanism, functionalization and applications in photocatalysis and H2S removal
Authors: Colombo Enrico , Li Wu , Bhangu Sukhvir Kaur , Ashokkumar Muthupandian
Published: March 2017

Highly efficient micron-sized photocatalysts with easy removability and recyclability features.
Non-swellable self-healing polymer with long-term stability under seawater
Authors: Kim Chaehoon , Ejima Hirotaka , Yoshie Naoko
Published: March 2017

A non-swellable and highly self-healable polymer in seawater is obtained. Dynamic crosslinking of catechol-based polymers with p-phenyldiboronic acid through non-ionic boronate ester bonds is the key to realizing these two properties simultaneously.
Cu2+1O/graphene nanosheets supported on three dimensional copper foam for sensitive and efficient non-enzymatic detection of glucose
Authors: Yang Liang , Liu Daoping , Cui Guomin , Xie Yingming
Published: March 2017

Three dimensional copper foam/Cu2+1O/graphene nanosheets for sensitive and efficient non-enzymatic detection of glucose.
Facile fabrication of silver nanoparticle-coated silica-C18 core–shell microspheres and their applications in SERS detection
Authors: Xue Lin , Gu Hai-Xin , Yuan Shou-Qi , Li Da-Wei
Published: March 2017

We present a one-step method to prepare silver nanoparticle (Ag NP) shell coated functional microspheres as a surface-enhanced Raman scattering (SERS) substrate.
Efficient delivery of nanoparticles to deep skin layers using dissolvable microneedles with an extended-length design
Authors: Su Liang-Cheng , Chen Mei-Chin
Published: March 2017

Dissolvable microneedles with an extended-length design can efficiently deliver NPs to the deep skin layers and prolong the skin retention time of NPs up to 5 days.
Electronic and thermal conduction properties of halogenated porous graphene nanoribbons
Authors: Nemnes G. A. , Visan Camelia , Manolescu A.
Published: March 2017

The electronic and thermal properties of halogenated porous graphene nanoribbons.
The structural and organic magnetoresistance response of poly(9-vinyl carbazole) using low applied magnetic fields and magnetic nanoparticle addition
Authors: Romero Mariano , Faccio Ricardo , Tumelero Milton A. , Pasa André A. , Mombrú Alvaro W.
Published: March 2017

Evidence of PVK singlet-to-triplet and structural modifications are revealed with the addition of magnetic nanoparticles and low applied magnetic fields.
Gain‐boosted dynamic amplifier for pipelined‐SAR ADCs
Authors: Zhang Minglei , Liu Qiyuan , Fan Xiaohua
Published: March 2017

A high‐gain and high‐speed gain‐boosted dynamic amplifier for pipelined‐successive approximation register ADCs is presented. A cross‐coupling cascode topology is proposed to boost the gain of a single‐stage dynamic amplifier. The proposed dynamic amplifier achieves a voltage gain of 32 under a 1.2 V power supply in 130 nm CMOS technology. Sampling at 150 MS/s, the proposed dynamic amplifier consumes a total power of 0.22 mW.
Axis Screw Fixation – A Step-by-Step Review of the Surgical Techniques
Authors: Joaquim Andrei , Riew K.
Published: March 2017

In this article, we present the techniques of axis screw fixation (laminar, pars, pedicle and transarticular screws), discussing the indications and contraindications of each one, as well as surgical tips and anatomical landmarks.
Eine Fortschreibung des Rehabilitationsbedarfs in Deutschland bis 2040 anhand demografischer Faktoren
Authors: Christiansen Marcus , Schmidt Jan-Philipp , Shkel David , Kaluscha Rainer , Tepohl Lena , Krischak Gert
Published: March 2017

Der demografische Wandel in Deutschland verändert nachhaltig die Zusammensetzung der Bevölkerung und beeinflusst damit auch den zukünftigen Bedarf an Rehabilitationsleistungen.

Diese Arbeit quantifiziert auf Basis einer Bevölkerungsfortschreibung bis 2040 die durch den demografischen Wandel zu erwartenden Veränderungen der medizinischen Rehabilitationsleistungen der gesetzlichen Rentenversicherung. Dazu wurde der Einfluss von demografischen Merkmalen auf die Rehabilitation geschätzt, um dann unter Verwendung einer stochastischen Bevölkerungsfortschreibung die zukünftige Ausgabenentwicklung zu prognostizieren.

Die Ergebnisse zeigen kurzfristig eine voraussichtliche Zunahme der Fälle in der medizinischen Rehabilitation. In den ersten Jahren des Prognosezeitraums (2010–2017) wäre theoretisch eine jährliche Lohnerhöhung von etwa 2,2% erforderlich, um die Kostensteigerung auszugleichen. Mittelfristig wird ein Rückgang der Rehabilitationsfälle aufgrund von Preissteigerungen bei gleichbleibenden Kosten prognostiziert.

Das Reha-Budget wird, angesichts der hier betrachteten Faktoren, mit großer Wahrscheinlichkeit die zukünftigen Mittel für medizinische Rehabilitationsleistungen nicht decken können. Langfristige Vorhersagen sind jedoch mit großer Unsicherheit behaftet.
Side-group size effects on interfaces and glass formation in supported polymer thin films
Authors: Xia Wenjie , Song Jake , Hsu David D. , Keten Sinan
Published: March 2017

Recent studies on glass-forming polymers near interfaces have emphasized the importance of molecular features such as chain stiffness, side-groups, molecular packing, and associated changes in fragility as key factors that govern the magnitude of Tg changes with respect to the bulk in polymer thin films. However, how such molecular features are coupled with substrate and free surface effects on Tg in thin films remains to be fully understood. Here, we employ a chemically specific coarse-grained polymer model for methacrylates to investigate the role of side-group volume on glass formation in bulk polymers and supported thin films. Our results show that bulkier side-groups lead to higher bulk Tg and fragility and are associated with a pronounced free surface effect on overall Tg depression. By probing local Tg within the films, however, we find that the polymers with bulkier side-groups experience a reduced confinement-induced increase in local Tg near a strongly interacting substrate. Further analyses indicate that this is due to the packing frustration of chains near the substrate interface, which lowers the attractive interactions with the substrate and thus lessens the surface-induced reduction in segmental mobility. Our results reveal that the size of the polymer side-group may be a design element that controls the confinement effects induced by the free surface and substrates in supported polymer thin films. Our analyses provide new insights into the factors governing polymer dynamics in bulk and confined environments.
Janus particle rotator-to-lamellar nucleation and growth kinetics
Authors: Beltran-Villegas Daniel J. , Zhang Yulei , Larson Ronald G.
Published: March 2017

We determine the free energy barrier, critical nucleus size, and kinetics of a Janus particle solid-solid transition by nucleation and growth of lamellar clusters within a metastable rotator phase. The transition involves negligible change in particle position and phase volume and entails only particle orientational ordering. Fast kinetics enable the analysis of unbiased crystal growth and shrinkage trajectories from Brownian dynamic simulations. By fitting simulation trajectories to a diffusion-migration equation, the nucleus free energy and growth coefficient as a function of nucleus size are extracted. Observed transition times are on the order of hundreds of characteristic particle rotation times. Lamellar crystal nuclei are oblate rather than spherical, but otherwise classical nucleation theory applies, with the bulk free energy contribution following closely the Maier-Saupe theory for purely orientational transitions and the interfacial energy contribution following trends from 3-dimensional Ising spin kinetics.
Development of theoretical approach for describing electronic properties of hetero-interface systems under applied bias voltage
Authors: Iida Kenji , Noda Masashi , Nobusada Katsuyuki
Published: March 2017

We have developed a theoretical approach for describing the electronic properties of hetero-interface systems under an applied electrode bias. The finite-temperature density functional theory is employed for controlling the chemical potential in their interfacial region, and thereby the electronic charge of the system is obtained. The electric field generated by the electronic charging is described as a saw-tooth-like electrostatic potential. Because of the continuum approximation of dielectrics sandwiched between electrodes, we treat dielectrics with thicknesses in a wide range from a few nanometers to more than several meters. Furthermore, the approach is implemented in our original computational program named grid-based coupled electron and electromagnetic field dynamics (GCEED), facilitating its application to nanostructures. Thus, the approach is capable of comprehensively revealing electronic structure changes in hetero-interface systems with an applied bias that are practically useful for experimental studies. We calculate the electronic structure of a SiO2–graphene–boron nitride (BN) system in which an electrode bias is applied between the graphene layer and an electrode attached on the SiO2 film. The electronic energy barrier between graphene and BN is varied with an applied bias, and the energy variation depends on the thickness of the BN film. This is because the density of states of graphene is so low that the graphene layer cannot fully screen the electric field generated by the electrodes. We have demonstrated that the electronic properties of hetero-interface systems are well controlled by the combination of the electronic charging and the generated electric field.
How strongly do hydrogen and water molecules stick to carbon nanomaterials?
Authors: Al-Hamdani Yasmine S. , Alfè Dario , Michaelides Angelos
Published: March 2017

The interaction strength of molecular hydrogen and water to carbon nanomaterials is relevant to, among many applications, hydrogen storage, water treatment, and water flow. However, accurate interaction energies for hydrogen and water with carbon nanotubes (CNTs) remain scarce despite the importance of having reliable benchmark data to inform experiments and to validate computational models. Here, benchmark fixed-node diffusion Monte Carlo (DMC) interaction energies are provided for hydrogen and water monomers inside and outside a typical zigzag CNT. The DMC interaction energies provide valuable insight into molecular interactions with CNTs in general and are also expected to be particularly relevant to gas uptake studies on CNTs. In addition, a selection of density functional theory (DFT) exchange-correlation (xc) functionals and force field potentials that ought to be suitable for these systems is compared. An unexpected variation is found in the performance of DFT van der Waals (vdW) models in particular. An analysis of the peculiar discrepancy between different vdW models indicates that medium-range correlation (at circa 3 to 5 Å) plays a key role inside CNTs and is poorly predicted by some vdW models. Using accurate reference information, this work reveals which xc functionals and force fields perform well for molecules interacting with CNTs. The findings will be valuable to future work on these and related systems that involve molecules interacting with low-dimensional systems.
Conduction in In2O3/YSZ heterostructures: Complex interplay between electrons and ions, mediated by interfaces
Authors: Veal B. W. , Eastman J. A.
Published: March 2017

Thin film In2O3/YSZ heterostructures exhibit significant increases in electrical conductance with time when small in-plane electric fields are applied. Contact resistances between the current electrodes and film and between the current electrodes and substrate are responsible for the behavior. With an in-plane electric field, different field profiles are established in the two materials, with the result that oxygen ions can be driven across the heterointerface, altering the doping of the n-type In2O3. A low frequency inductive feature observed in AC impedance spectroscopy measurements under DC bias conditions was found to be due to frequency-dependent changes in the contact resistance.
Note: A portable rotating waveplate polarimeter
Authors: Bobach Søren , Hidic Adnan , Arlt Jan J. , Hilliard Andrew J.
Published: March 2017

We describe the construction and performance of a polarimeter based on a quarter-wave plate rotated by a model airplane motor. The motor rotates at a high angular frequency of ω∼2π×160 Hz, which enables the polarimeter to monitor the polarization state of an incident beam of light in real-time. We show that a simple analysis of the polarimeter signal using the fast Fourier transform on a standard digital oscilloscope provides an excellent measure of the polarization state for many laboratory applications. The polarimeter is straightforward to construct, portable, and features a high-dynamic range, facilitating a wide range of optics laboratory tasks that require free-space or fiber-based polarization analysis.
Anomalous spin disordered properties of strongly correlated honeycomb compound In3Cu2VO9
Authors: Jia Shi-Qing , Wang Qing-Wei , Yu Xiang-Long , Zou Liang-Jian
Published: March 2017

We study the ground-state and finite-temperature magnetic properties of an interlayer frustrated J1 − J2 − Jc Heisenberg model on three-dimensional honeycomb lattice by employing the Schwinger boson mean-field theory, focusing on the low-energy physics in In3Cu2VO9. We find that with the increase of interlayer coupling Jc from 0 to 3.6 meV, the interlayer frustrated system transits from an antiferromagnetic (AFM) phase to a state with intralayer AFM order and interlayer disorder. This spin disordered phase explains not only the intralayer phase transition at TN = 38 K, but also the qualitative behaviors of the intermediate-temperature specific heat and magnetic susceptibility of In3Cu2VO9.
Determination of domain wall chirality using in situ Lorentz transmission electron microscopy
Authors: Chess Jordan J. , Montoya Sergio A. , Fullerton Eric E. , McMorran Benjamin J.
Published: March 2017

Controlling domain wall chirality is increasingly seen in non-centrosymmetric materials. Mapping chiral magnetic domains requires knowledge about all the vector components of the magnetization, which poses a problem for conventional Lorentz transmission electron microscopy (LTEM) that is only sensitive to magnetic fields perpendicular to the electron beams direction of travel. The standard approach in LTEM for determining the third component of the magnetization is to tilt the sample to some angle and record a second image. This presents a problem for any domain structures that are stabilized by an applied external magnetic field (e.g. skyrmions), because the standard LTEM setup does not allow independent control of the angle of an applied magnetic field, and sample tilt angle. Here we show that applying a modified transport of intensity equation analysis to LTEM images collected during an applied field sweep, we can determine the domain wall chirality of labyrinth domains in a perpendicularly magnetized material, avoiding the need to tilt the sample.
The relationship between dynamic and pseudo-thermodynamic measures of the glass transition temperature in nanostructured materials
Authors: Mangalara Jayachandra Hari , Mackura Mark E. , Marvin Michael D. , Simmons David S.
Published: March 2017

Despite decades of research on the effects of nanoconfinement on the glass transition temperature Tg, apparent discrepancies between pseudothermodynamic and dynamic measurements of these effects have raised questions regarding the presence of long-ranged interfacial dynamic gradients in glass-forming liquids. Here we show that these differences can be accounted for based on disparities in these methods’ weightings over local Tg’s within an interfacial gradient. This finding suggests that a majority of experimental data are consistent with a broad interfacial dynamic interphase in glass-forming liquids.
Characterization of vascular permeability using a biomimetic microfluidic blood vessel model
Authors: Thomas Antony , Wang Shunqiang , Sohrabi Salman , Orr Colin , He Ran , Shi Wentao , Liu Yaling
Published: March 2017

The inflammatory response in endothelial cells (ECs) leads to an increase in vascular permeability through the formation of gaps. However, the dynamic nature of vascular permeability and external factors involved is still elusive. In this work, we use a biomimetic blood vessel (BBV) microfluidic model to measure in real-time the change in permeability of the EC layer under culture in physiologically relevant flow conditions. This platform studies the dynamics and characterizes vascular permeability when the EC layer is triggered with an inflammatory agent using tracer molecules of three different sizes, and the results are compared to a transwell insert study. We also apply an analytical model to compare the permeability data from the different tracer molecules to understand the physiological and bio-transport significance of endothelial permeability based on the molecule of interest. A computational model of the BBV model is also built to understand the factors influencing transport of molecules of different sizes under flow. The endothelial monolayer cultured under flow in the BBV model was treated with thrombin, a serine protease that induces a rapid and reversible increase in endothelium permeability. On analysis of permeability data, it is found that the transport characteristics for fluorescein isothiocyanate (FITC) dye and FITC Dextran 4k Da molecules are similar in both BBV and transwell models, but FITC Dextran 70k Da molecules show increased permeability in the BBV model as convection flow (Peclet number > 1) influences the molecule transport in the BBV model. We also calculated from permeability data the relative increase in intercellular gap area during thrombin treatment for ECs in the BBV and transwell insert models to be between 12% and 15%. This relative increase was found to be within range of what we quantified from F-actin stained EC layer images. The work highlights the importance of incorporating flow in in vitro vascular models, especially in studies involving transport of large size objects such as antibodies, proteins, nano/micro particles, and cells.
Visualizing electromagnetic fields in metals by MRI
Authors: Chandrashekar Chandrika Sefcikova , Shellikeri Annadanesh , Chandrashekar S. , Taylor Erika A. , Taylor Deanne M.
Published: March 2017

Based upon Maxwell’s equations, it has long been established that oscillating electromagnetic (EM) fields incident upon a metal surface, decay exponentially inside the conductor, leading to a virtual absence of EM fields at sufficient depths. Magnetic resonance imaging (MRI) utilizes radiofrequency (r.f.) EM fields to produce images. Here we present a visualization of a virtual EM vacuum inside a bulk metal strip by MRI, amongst several findings. At its simplest, an MRI image is an intensity map of density variations across voxels (pixels) of identical size (=Δx Δy Δz). By contrast in bulk metal MRI, we uncover that despite uniform density, intensity variations arise from differing effective elemental volumes (voxels) from different parts of the bulk metal. Further, we furnish chemical shift imaging (CSI) results that discriminate different faces (surfaces) of a metal block according to their distinct nuclear magnetic resonance (NMR) chemical shifts, which holds much promise for monitoring surface chemical reactions noninvasively. Bulk metals are ubiquitous, and MRI is a premier noninvasive diagnostic tool. Combining the two, the emerging field of bulk metal MRI can be expected to grow in importance. The findings here may impact further development of bulk metal MRI and CSI.
Time resolved photoluminescence on Cu(In, Ga)Se2 absorbers: Distinguishing degradation and trap states
Authors: Redinger Alex , Levcenko Sergiu , Hages Charles J. , Greiner Dieter , Kaufmann Christian A. , Unold Thomas
Published: March 2017

Recent reports have suggested that the long decay times in time resolved photoluminescence (TRPL), often measured in Cu(In, Ga)Se2 absorbers, may be a result of detrapping from sub-bandgap defects. In this work, we show via temperature dependent measurements, that long lifetimes >50 ns can be observed that reflect the true minority carrier lifetime not related to deep trapping. Temperature dependent time resolved photoluminescence and steady state photoluminescence imaging measurements are used to analyze the effect of annealing in air and in a nitrogen atmosphere between 300 K and 350 K. We show that heating the Cu(In, Ga)Se2 absorber in air can irreversibly decrease the TRPL decay time, likely due to a deterioration of the absorber surface. Annealing in an oxygen-free environment yields a temperature dependence of the TRPL decay times in accordance with Schockley Read Hall recombination kinetics and weakly varying capture cross sections according to T0.6.
Variation of coercivity with Ce content in (Pr,Nd,Ce)2Fe14B sintered magnets
Authors: Zhang Xue-feng , Zhang Le-le , Li Zhu-bai , Lan Jian-ting , Liu Yan-li , Ma Qiang , Li Yong-feng , Zhao Qian
Published: March 2017

The variation of coercivity with Ce content was investigated in (Pr,Nd)15-xCexFe77B8 (x=0∼10) sintered magnets. The coercivity of magnets largely decreases from 10.22 to 5.4 kOe with increasing x from 0 to 2. The coercivity rises to 7.68 kOe when x=3 and then decreases again with further increasing Ce content. However, both the magnetocrystalline anisotropy and Curie temperature decrease monotonically with increasing Ce content. EDS composition analysis shows that the Ce concentration in the Re2Fe14B main phase is higher than that in the nominal composition when x≤3, but becomes lower when x>3. These results indicate that Ce tends to be expelled from the main phase and segregates at or near the grain boundary regions if Pr-Nd is excessively substituted by Ce. The change of relative solubility of Ce in Re2Fe14B would lead to the change of distributions of Ce and Pr-Nd elements, and thus result in the change of anisotropy at the grain outer layer, contributing to the abnormal behavior of coercivity. These studied results are also expected to provide a guideline for optimizing the composition design of resource-saving permanent magnets.