bluuebunny/crossref_metadata_2025 huggingface dataset:
Diastolic function in anthracycline-treated children
Authors: Harahsheh Ashraf , Aggarwal Sanjeev , Pettersen Michael D. , L’Ecuyer Thomas
Published: September 2014

Background: Anthracyclines are effective medications for childhood cancer. Their limitation is the risk of cardiomyopathy. Although diastolic dysfunction has been described in patients who received anthracyclines, cardiac monitoring has focused on systolic function, which is abnormal in up to 41% of the patients. We conducted a study to assess diastolic function utilising transmitral inflow Doppler velocities and tissue Doppler imaging in anthracycline-treated children 5 years post-therapy. Methods: This was a retrospective study on 63 anthracycline-treated patients. Echocardiographic parameters included peak early and late transmitral inflow Doppler velocities (E, A), E/A ratio, E deceleration time, and tissue Doppler imaging early and late diastolic mitral annulus velocities (E′, A′), E/E′ ratio, and E′/A′ ratio. Results: All indices of diastolic function that we measured were normal in the anthracycline-treated patients. Conclusion: We conclude that diastolic function assessed by transmitral inflow Doppler velocities and tissue Doppler imaging is normal in anthracycline-treated children 5 years after completion of treatment. Further longitudinal study is needed to determine whether diastolic function becomes abnormal with time in this patient population.
Long-term outcome and anaesthetic management for non-cardiac surgery after Fontan palliation: a single-centre retrospective analysis
Authors: Palumbo Thomas , Sluysmans Thierry , Rubay Jean E. , Poncelet Alain J. , Momeni Mona
Published: September 2014

Objectives:The improved management of Fontan patients has resulted in good outcome. As such, these patients may necessitate care for non-cardiac surgery. We sought to determine the long-term outcome of our Fontan series palliated with the most recent surgical techniques. Our second objective was to report the incidence and the perioperative course after non-cardiac procedures. We reviewed the records of all patients with either a lateral tunnel or an extracardiac conduit Fontan between 1996 and 2008. Follow-up was recorded until June, 2013, including records regarding non-cardiac interventions.Results:Overall, 58 patients were included. Of them, one patient underwent a takedown of his Fontan, and five patients died in the immediate postoperative course. The cumulative survival of the remaining 52 patients was 81%. There was no significant difference in survival between right and left ventricle morphologies (p=0.56), nor between both types of Fontan (p=0.9). Chronic arrhythmias (25%), fatigue/dyspnoea (40%), thrombotic complications (19%), and embolic events (10%) were among the most recurrent comorbidities. In total, 45 non-cardiac interventions were performed on 26 patients, with three bleeding complications and one death.Conclusions:This study shows excellent long-term survival after both lateral tunnel and extracardiac conduit Fontan. The incidence of cardiovascular morbidity remains high, however. We also report a high number of non-cardiac interventions. Thorough understanding of the Fontan physiology is mandatory when non-cardiac anaesthesiologists are in charge of these patients.
Default Network Connectivity Is Linked to Memory Status in Multiple Sclerosis
Authors: Leavitt Victoria M. , Paxton Jessica , Sumowski James F.
Published: September 2014

Memory impairment affects 50% of multiple sclerosis (MS) patients. Altered resting-state functional connectivity (FC) has been observed in the default network (DN) of MS patients. No study to date has examined the association of DN FC to its behavioral concomitant, memory. The approach of the present study represents a methodological shift allowing straightforward interpretation of FC alterations in MS, as it presupposes specificity of a network to its paired cognitive function. We examined FC from fMRI collected during rest in the DN of 43 MS patients with and without memory-impairment. Memory-intact patients showed increased DN FC relative to memory-impaired patients. There were no regions of higher FC in memory-impaired patients. DN FC was positively correlated with memory function, such that higher FC was associated with better memory performance. Results were unchanged after controlling for cognitive efficiency, supporting specificity of the DN to memory and not cognitive status more generally. These findings support DN FC as a marker of memory function in MS patients that can be targeted by future treatment interventions. Pairing a functional network with its behavioral concomitant represents a straightforward method for interpreting FC alterations in patients with MS. (JINS, 2014, 20, 1–8)
Health professionals responding to men for safety (HERMES): feasibility of a general practice training intervention to improve the response to male patients who have experienced or perpetrated domestic violence and abuse
Authors: Williamson Emma , Jones Sue K. , Ferrari Giulia , Debbonaire Thangam , Feder Gene , Hester Marianne
Published: September 2014

Aim

To evaluate a training intervention for general practice-based doctors and nurses in terms of the identification, documentation, and referral of male patients experiencing or perpetrating domestic violence and abuse (DVA) in four general practices in the south west of England.

Background

Research suggests that male victims and perpetrators of DVA present to primary care clinicians to seek support for their experiences. We know that the response of primary care clinicians to women patients experiencing DVA improves from training and the establishment of referral pathways to specialist DVA services.

Method

The intervention consisted of a 2-h practice-based training. Outcome measures included: a pre-post, self-reported survey of staff practice; disclosures of DVA as documented in medical records pre-post (six months) intervention; semi-structured interviews with clinicians; and practice-level contact data collected by DVA specialist agencies.

Results

Results show a significant increase in clinicians’ self-reported preparedness to meet the needs of male patients experiencing or perpetrating DVA. There was a small increase in male patients identified within the medical records (6 pre- to 17 post-intervention) but only five of those patients made contact with a specialist DVA agency identified within the referral pathway. The training increased clinicians’ confidence in responding to male patients affected by DVA. The increase in recorded identification of DVA male patients experiencing or perpetrating DVA was small and contact of those patients with a specialist DVA support service was negligible. We need to better understand male help seeking in relation to DVA, further develop interventions to increase identification of male patients experiencing or perpetrating DVA behaviours, and facilitate access to support services.
Erratum: Nutrients drive transcriptional changes that maintain metabolic homeostasis but alter genome architecture in Microcystis
Authors: Steffen Morgan M , Dearth Stephen P , Dill Brian D , Li Zhou , Larsen Kristen M , Campagna Shawn R , Wilhelm Steven W
Published: September 2014

Correction to: The ISME Journal (2014) 8, 2080–2092; doi:10.1038/ismej.2014.78; published online 23 May 2014 Since the publication of this article, the authors have noticed an incorrect axis label in one of the figures. In Figure 2b, the x axis should read ‘N-Reduced (Nitrate) Mean Normalized RPKM (log10)’.
Leptin deficiency in maltreated children
Authors: Danese A , Dove R , Belsky D W , Henchy J , Williams B , Ambler A , Arseneault L
Published: September 2014

Consistent with findings from experimental research in nonhuman primates exposed to early-life stress, children exposed to maltreatment are at high risk of detrimental physical health conditions, such as obesity and systemic inflammation. Because leptin is a key molecule involved in the regulation of both energy balance and immunity, we investigated abnormalities in leptin physiology among maltreated children. We measured leptin, body mass index and C-reactive protein in 170 12-year-old children members of the Environmental-Risk Longitudinal Twin Study, for whom we had prospectively-collected information on maltreatment exposure. We found that maltreated children exhibited blunted elevation in leptin levels in relation to increasing levels of physiological stimuli, adiposity and inflammation, compared with a group of non-maltreated children matched for gender, zygosity and socioeconomic status. These findings were also independent of key potential artifacts and confounders, such as time of day at sample collection, history of food insecurity, pubertal maturation and depressive symptoms. Furthermore, using birth weight as a proxy measure for leptin, we found that physiological abnormalities were presumably not present at birth in children who went on to be maltreated but only emerged over the course of childhood, after maltreatment exposure. Leptin deficiency may contribute to onset, persistence and progression of physical health problems in maltreated children.
HPLC-MRM relative quantification analysis of fatty acids based on a novel derivatization strategy
Authors: Cai Tie , Ting Hu , Xin-Xiang Zhang , Jiang Zhou , Jin-Lan Zhang
Published: September 2014

Sensitive and convenience fatty acid HPLC-MRM quantification methods were developed based on a novel derivatization strategy.
Micellar and vesicular nanoassemblies of triazole-based amphiphilic probes triggered by mercury(ii) ions in a 100% aqueous medium
Authors: Kim Inhye , Lee Na-Eun , Jeong Yoo-Jeong , Chung Young-Ho , Cho Byoung-Ki , Lee Eunji
Published: September 2014

Selective Hg2+-binding of click-derived triazole-based amphiphiles can lead to the formation of nanostructures, even below CMCs, which are determined by the stoichiometry of amphiphile–Hg2+ complexes affecting the interfacial curvature.
Hierarchical porous metal–organic framework monoliths
Authors: Ahmed Adham , Forster Mark , Clowes Rob , Myers Peter , Zhang Haifei
Published: September 2014

A simple powder-packing synthesis is developed to produce crystalline MOF monoliths containing micropores and highly interconnected macropores. Fast HPLC separation using the monolithic column is demonstrated.
The characterization of the saddle shaped nickel(iii) porphyrin radical cation: an explicative NMR model for a ferromagnetically coupled metallo-porphyrin radical
Authors: Cheng Ru-Jen , Ting Chiao-Han , Chao Ten-Chih , Tseng Tzu-Hsien , Chen Peter P.-Y.
Published: September 2014

Ni(iii)(OETPP˙)(Br)2 is the first Ni(iii) porphyrin radical cation with structural and 1H and 13C paramagnetic NMR data for porphyrinate systems.
A universal molecular translator for non-nucleic acid targets that enables dynamic DNA assemblies and logic operations
Authors: Tang Wei , Hu Shichao , Wang Huaming , Zhao Yan , Li Na , Liu Feng
Published: September 2014

A universal molecular translator was developed to convert various kinds of non-nucleic acid targets into a unique output DNA.
Cocrystallization of pyrogallol[4]arenes with 1-(2-pyridylazo)-2-naphthol
Authors: Pfeiffer Constance R. , Fowler Drew A. , Teat Simon , Atwood Jerry L.
Published: September 2014

Mapping the effects of various solvent systems and varying aliphatic tails lengths of cocrystals composed of pyrogallol[4]arenes and 1-(2-pyridylazo)-2-naphthol.
Formaldehyde chemistry in cometary ices: the case of HOCH2OH formation
Authors: Duvernay F. , Rimola A. , Theule P. , Danger G. , Sanchez T. , Chiavassa T.
Published: September 2014

Laboratory experiments devoted to simulate the chemistry occurring in interstellar and cometary ice analogues are of paramount importance to understand the formation of complex organic molecules that are detected throughout the universe.
Maximizing n-alkane hydroisomerization: the interplay of phase, feed complexity and zeolite catalyst mixing
Authors: Vandegehuchte B. D. , Thybaut J. W. , Martens J. A. , Marin G. B.
Published: September 2014

The preferred hydroisomerization of heavy alkanes in parapur on Y–ZSM22 is counterbalanced by physisorption destabilization effects which emerge at micropore saturation.
Ultrafast spectroscopy and structural characterization of a photochromic isomerizing ruthenium bis-sulfoxide complex
Authors: King Albert W. , Malizia Jason P. , Engle James T. , Ziegler Christopher J. , Rack Jeffrey J.
Published: September 2014

Irradiation of [Ru(bpy)2(bpSOp)](PF6)2 (where bpy is 2,2′-bipyridine and bpSOp is 1,3-bis(phenylsulfinyl)propane) results in the formation of two new isomers, namely the S,O- and O,O-bonded species.
Parameter free calculation of the subgap density of states in poly(3-hexylthiophene)
Authors: Frost Jarvist M. , Kirkpatrick James , Kirchartz Thomas , Nelson Jenny
Published: September 2014

We investigate the influence of intra-chain and inter-chain interactions on the sub-gap density of states in a conjugated polymer using a combination of atomistic molecular dynamics simulation of polymer film structure and tight-binding calculation of electronic energy levels. For disordered assemblies of poly-3-hexylthiophene we find that the tail of the density of hole states is approximately exponential with a characteristic energy of 37 meV, which is similar to experimental values. This tail of states arises mainly from variations in the electronic coupling between neighbouring monomers, and is only slightly influenced by interchain coupling. Thus, knowledge of the disorder in torsion between neighbouring monomers is sufficient to estimate the density of states for the polymer. However, the intrachain torsional disorder is determined largely by the packing of the chains rather than the torsional potential alone. We propose the combination of methods as a tool to design higher mobility conjugated polymers.
Parallel microfluidic chemosensitivity testing on individual slice cultures
Authors: Chang Tim C. , Mikheev Andrei M. , Huynh Wilson , Monnat Raymond J. , Rostomily Robert C. , Folch Albert
Published: September 2014

A 96-well plate-based microfluidic device enables multiplexed delivery of soluble molecules to organotypic tissue slices.
Breakup dynamics and dripping-to-jetting transition in a Newtonian/shear-thinning multiphase microsystem
Authors: Ren Yong , Liu Zhou , Shum Ho Cheung
Published: September 2014

The shear dependence of the viscosity of shear-thinning fluids changes the dynamics of jet breakup, necessitating new approaches for its control.
Rational design of protein–protein interaction inhibitors
Authors: Rognan Didier
Published: September 2014

Low molecular weight compound competing for the binding of the p53 tumor suppressor to the MDM2 oncoprotein.
Copper overload and deficiency both adversely affect the central nervous system of Drosophila
Authors: Hwang Joab E. C. , de Bruyne Marinus , Warr Coral G. , Burke Richard
Published: September 2014

Ectopic neuronal copper efflux causes a functional copper deficiency leading to developmental lethality in Drosophila.
Thermodynamic epimeric equilibration and crystallisation-induced dynamic resolution of lobelanine, norlobelanine and related analogues
Authors: Amara Z. , Bernadat G. , Venot P.-E. , Retailleau P. , Troufflard C. , Drège E. , Le Bideau F. , Joseph D.
Published: September 2014

The step-economical synthesis of lobelanine involving a ring closing double aza-Michael (RCDAM) reaction is revisited and successfully extended to the synthesis of various configurationally more stable analogues.
Preparation of graphene/poly(2-hydroxyethyl acrylate) nanohybrid materials via an ambient temperature “grafting-from” strategy
Authors: Liu Zhanzhan , Zhu Shaojia , Li Yongjun , Li Yongsheng , Shi Ping , Huang Zhong , Huang Xiaoyu
Published: September 2014

PHEA polymer brushes were grownin situfrom the surface of graphene sheetsviaSET-LRP through a “grafting-from” strategy at ambient temperature to afford the PHEA/graphene hybrid material with excellent dispersibility in organic solvents.
Combining the incompatible: Block copolymers consecutively displaying activated esters and amines and their use as protein-repellent surface modifiers with multivalent biorecognition
Authors: Hoenders Daniel , Tigges Thomas , Walther Andreas
Published: September 2014

We present the facile synthesis and orthogonal functionalization of diblock copolymers consisting of two incompatible segments, i.e. primary amines and activated esters, and demonstrate their use as protein-repellent brush layers with multivalent biorecognition.
A method for introducing organic functional groups on silica surfaces using a functionalized vinylsilane containing polymer
Authors: Park Jung-Woo , Kim Dong-Su , Kim Min-Seok , Choi Ji-Hwan , Jun Chul-Ho
Published: September 2014

A new method for introducing robustly bound organic functional groups on the silica surface using a vinylsilane-containing polymer is developed.
Ni(OH)2@Cu dendrite structure for highly sensitive glucose determination
Authors: Jung Hyeri , Lee Sang Ha , Yang Jiao , Cho Misuk , Lee Youngkwan
Published: September 2014

Facile preparation of a nickel hydroxide-coated copper dendrite structure and excellent performance in glucose detection with sensitivity of 2082 μA mM−1cm−2.
Out of cross-conjugation: the unexpected structure of tetrazinones
Authors: Bényei A. C. , Stirling A. , Bostai B. , Lőrincz K. , Kotschy A.
Published: September 2014

Combined experimental and theoretical investigations helped to elucidate the mechanisms responsible for the unique structural and electronic properties of NHC-substituted tetrazinone compounds.
Synthesis and properties of soap-free P(2-EHA-BA) emulsion for removable pressure sensitive adhesives
Authors: Zhang Lei , Cao Yingjie , Wang Lei , Shao Lu , Bai Yongping
Published: September 2014

Soap-free P(2-EHA-BA) emulsion for removable PSAs applications with good stabilities and adhesion properties has been successfully synthesized.
Copper-catalyzed acyloxylation of the C(sp3)–H bond adjacent to an oxygen by a cross-dehydrogenative coupling approach
Authors: Raju Kammari Bal , Kumar Bejjanki Naveen , Nagaiah Kommu
Published: September 2014

We demonstrated a dehydrogenative cross coupling between a benzyl alcohol and C(sp3)–H bond for the construction of a C–O bond. This method reveals a new strategy for the direct use of benzyl alcohols in the synthesis of esters with the use of copper as a catalyst and TBHP as an oxidant.
Reducing the adhesion and friction forces of Si by coating ultra-thin Al2O3 films
Authors: Chai Zhimin , Liu Yuhong , Lu Xinchun , He Dannong
Published: September 2014

Si-based microelectromechanical system (MEMS) devices cannot run reliably because of their poor tribological performance.
In situ synthesis of Au–Pd bimetallic nanoparticles on amine-functionalized SiO2 for the aqueous-phase hydrodechlorination of chlorobenzene
Authors: Wang Xinkui , Liu Qinggang , Xiao Zihui , Chen Xiao , Shi Chuan , Tao Shengyang , Huang Yanqiang , Liang Changhai
Published: September 2014

The homogeneous Au–Pd NPs have been prepared through a facile in situ reduction method. The optimal AuPd1.0/SiO2 catalyst could complete the conversion of chlorobenzene due to the high dispersion and modified electronic properties of Pd.
Supramolecular gels for the remediation of reactive organophosphorus compounds
Authors: Hiscock Jennifer R. , Kirby Isabelle L. , Herniman Julie , John Langley G. , Clark Alistair J. , Gale Philip A.
Published: September 2014

Pyridine-based gels formed with a cyclohexyl diamide gelator have been shown to undergo a gel–sol transition upon addition of the organophosphorus (OP) chemical warfare agent (CWA) simulant diethyl chlorophosphate (DCP).
Ultrafine carbamazepine nanoparticles with enhanced water solubility and rate of dissolution
Authors: Kumar Raj , Siril Prem Felix
Published: September 2014

Solubility of carbamazepine (CBZ) nanoparticles and CBZ–PVP nanoparticles was 11.9 and 21.5 times higher than the raw–CBZ.
BF3·OEt2-mediated one pot synthesis of 10-indolyldibenzo[b,f]azepine derivatives via tandem ring expansion and C–C bond formation
Authors: Kotipalli Trimurtulu , Janreddy Donala , Kavala Veerababurao , Kuo Chun-Wei , Kuo Ting-Shen , Chen Mei-Ling , He Chiu-Hui , Yao Ching-Fa
Published: September 2014

A simple and efficient one pot protocol was developed for the synthesis of new structurally diverse 10-indolyldibenzo[b,f]azepine derivatives.
A novel TiO2-assisted magnetic nanoparticle separator for treatment and inactivation of bacterial contaminants in aquatic systems
Authors: Müller Werner E. G. , Link Thorben , Li Qiang , Schröder Heinz C. , Batel Renato , Blažina Maria , Grebenjuk Vladislav A. , Wang Xiaohong
Published: September 2014

The photocatalytic method and the magnetic nanoparticle separator, described here, allow a fast and efficient elimination of bacteria from aqueous solution and can be applied for remediation of aquatic environments.
Divergent regioselectivity in photoredox-catalyzed hydrofunctionalization reactions of unsaturated amides and thioamides
Authors: Morse Peter D. , Nicewicz David A.
Published: September 2014

A direct method to construct 2-oxazolines and 2-thiazolines from corresponding allylic amides and thioamides is reported.
Harnessing selenocysteine reactivity for oxidative protein folding
Authors: Metanis Norman , Hilvert Donald
Published: September 2014

Turbo-charged folding with selenium: targeted replacement of cysteines in proteins with selenocysteines is a valuable strategy for increasing the rates of oxidative protein folding, altering folding mechanisms, and rescuing kinetically trapped intermediates.
Core–shell structured phosphorescent nanoparticles for detection of exogenous and endogenous hypochlorite in live cells via ratiometric imaging and photoluminescence lifetime imaging microscopy
Authors: Zhang Kenneth Yin , Zhang Jie , Liu Yahong , Liu Shujuan , Zhang Pinglin , Zhao Qiang , Tang Yan , Huang Wei
Published: September 2014

Core-shell phosphorescent nanoparticles were used to detect intracellular ClO−via ratiometric and photoluminescence lifetime imaging.
Swim stress, motion, and deformation of active matter: effect of an external field
Authors: Takatori Sho C. , Brady John F.
Published: September 2014

We analyze the stress, dispersion, and average swimming speed of self-propelled particles subjected to an external field, and discuss a method to manipulate soft compressible materials as nano/micromechanical devices and motors.
Encapsulation of anticancer drug by hydrogen-bonded multilayers of tannic acid
Authors: Liu Fei , Kozlovskaya Veronika , Zavgorodnya Oleksandra , Martinez-Lopez Claudia , Catledge Shane , Kharlampieva Eugenia
Published: September 2014

Hydrogen-bonded layer-by-layer capsules of tannic acid were used for highly efficient doxorubicin encapsulation and storage in the pH range 5 < pH < 7.5.
Site specific supramolecular heterogeneous catalysis by optically patterned soft oxometalate–porous organic framework (SOM–POF) hybrid on a chip
Authors: Thomas Preethi , Pei Cuiying , Roy Basudev , Ghosh Subhrokoli , Das Santu , Banerjee Ayan , Ben Teng , Qiu Shilun , Roy Soumyajit
Published: September 2014

We have designed a supramolecularly bound multi-component catalytic material based on a soft oxometalate (SOM) and a porous organic framework (POF) material, which shows high catalytic conversion efficiency.
Battery/supercapacitor hybrid via non-covalent functionalization of graphene macro-assemblies
Authors: Campbell P. G. , Merrill M. D. , Wood B. C. , Montalvo E. , Worsley M. A. , Baumann T. F. , Biener J.
Published: September 2014

A 2.9-fold increase in electrical energy storage capacity (up to 23 W h kg−1) is achieved in battery/supercapacitor hybrid electrodes through non-covalent modification of binder-free, ultra-high surface area graphene macro-assemblies with redox-active anthraquinone. These hybrid electrodes demonstrate battery-like energy density, supercapacitor-like power performance, and superb long-term stability.
3,7-Bis(trifluoromethyl)-N-ethylphenothiazine: a redox shuttle with extensive overcharge protection in lithium-ion batteries
Authors: Kaur Aman Preet , Ergun Selin , Elliott Corrine F. , Odom Susan A.
Published: September 2014

Constant overcharging of LiFePO4/synthetic graphite lithium-ion batteries in which the electrolyte additives 1,4-di-tert-butyl-2,5-dimethoxybenzene (DBB), N-ethylphenothiazine (EPT), and 3,7-bis(trifluoromethyl)-N-ethylphenothiazine (BCF3EPT) limit battery voltage.
MoS2 nanosheet/Mo2C-embedded N-doped carbon nanotubes: synthesis and electrocatalytic hydrogen evolution performance
Authors: Zhang Kai , Zhao Yang , Zhang Shen , Yu Hailong , Chen Yujin , Gao Peng , Zhu Chunling
Published: September 2014

Ultrathin MoS2 nanosheets were grown on Mo2C-embedded N-doped carbon nanotubes through in situ solid and subsequent hydrothermal reactions, showing excellent electrocatalytic activity for hydrogen evolution.
A magnesium tetraphenylaluminate battery electrolyte exhibits a wide electrochemical potential window and reduces stainless steel corrosion
Authors: Nelson Emily G. , Brody Scott I. , Kampf Jeff W. , Bartlett Bart M.
Published: September 2014

Using Al(OPh)3 rather than the typical AlCl3 with Grignard reagents affords a Mg-ion electrolyte with a reduced chloride content to enhance the stability on stainless steel.
Researching the dose ratio in a controlled release multiple-drug delivery system: using combination therapy with porous microparticles for the treatment of Helicobacter pylori infection
Authors: Hao Shilei , Wang Bochu , Wang Yazhou
Published: September 2014

Triple-drug loaded porous gastroretentive microparticles were prepared to treat Helicobacter pylori infection, and the mass ratios of the released drugs were in accordance with that in a triple therapy regimen.
Atomic layer deposition of Cu with a carbene-stabilized Cu(i) silylamide
Authors: Hagen Dirk J. , Povey Ian M. , Rushworth Simon , Wrench Jacqueline S. , Keeney Lynette , Schmidt Michael , Petkov Nikolay , Barry Seán T. , Coyle Jason P. , Pemble Martyn E.
Published: September 2014

The metal–organic Cu(i) complex 1,3-diisopropyl-imidazolin-2-ylidene copper hexamethyl disilazide has been tested as a novel oxygen-free precursor for atomic layer deposition of Cu with molecular hydrogen.
Design of electromagnetic wave absorber using periodic structure and method to broaden its bandwidth based on equivalent circuit‐based analysis
Authors: Sim Dong‐Uk , Kwon Jong‐Hwa , Chong Young‐Jun , Park Seong‐Ook
Published: September 2014

A new broadband electromagnetic wave absorber based on a periodic surface and a method to increase its absorption bandwidth is proposed. The proposed absorber structure shows broadband characteristics, and its bandwidth is improved by generating additional resonances through a reasonable approach. To provide an understanding of the logical design procedure, an analytical method to determine the sheet resistance and new equivalent circuit models for analysing the impedance are both presented. From the analysis, it is shown that the exact range of the sheet resistance corresponding to the desired absorption level can be efficiently estimated for the resonance of the structure. For the verification of this approach to obtain an efficient design, as well as the functionality of both the absorber and the proposed method, experimental results are demonstrated along with analytical and computational results. The final measured results using the proposed method show a broadband reflectivity response, with a fractional bandwidth of approximately 93% below −10 dB and a bandwidth increase of 17%.
Measurement and analysis of the lowest resonant mode of a spherical annular‐sector patch antenna
Authors: Weiss Steven , Cohl Howard , Boliong Amang
Published: September 2014

The cavity model for patch antennas has been used extensively since 1970s. This model gives excellent first‐order estimates for the antenna's internal fields near any resonant frequency. Although frequently used for planar geometries, there is no reason why the model cannot be employed for other geometries. This study discusses some of the complexities in selecting the correct pair of linearly independent associated Legendre functions when attempting to employ the cavity model using a spherical annular‐sector patch antenna.
Electromagnetic wave absorption characteristics of H‐shaped fractal antenna for dual‐band microbolometer and study on the influence of bias line resistivity on microbolometer characteristics
Authors: Takebe Kozaburo , Miyashita Hidetoshi , Takano Keisuke , Hangyo Masanori , Lee Sang‐Seok
Published: September 2014

A dual‐band microbolometer coupled with an H‐shaped fractal antenna, which can detect both infrared (IR) and THz waves simultaneously is proposed. Firstly, the H‐shaped fractal antenna for 125 and 500 μm dual‐bands is proposed by using the dipole antenna formula and finite element method (FEM) simulation. On the basis of simulation results, the H‐shaped fractal antenna for the microbolometer is fabricated and the electromagnetic wave absorption characteristics of it are measured. Transmission measurement successfully confirmed the absorption peaks near the aimed for two wavelengths in the IR and THz regions, respectively. It showed that the proposed microbolometer coupled with the H‐shaped fractal antenna is considered as a useful tool for widely separated multi‐band detection. Moreover, for the microbolometer design, the influence of bias line resistivity on microbolometer characteristics with two different bias line materials by the FEM simulation is studied. It is observed that the electromagnetic wave absorption characteristics of the microbolometer are affected by the resistivity of the bias line material, especially when the parallel polarised incident wave to the bias line formation direction is irradiated.
Effects of interface cohesion on mechanical properties of interpenetrating phase nanocomposites
Authors: Sun Xiao‐Yu , Xu Guang‐Kui , Zhang Jun‐Hui , Xu Yuan‐Jie
Published: September 2014

Molecular dynamics simulations and micromechanics model analysis are performed to investigate the mechanical behaviours and interfacial effects of interpenetrating phase composites in the nanoscale. It is observed that the overall Young's modulus and ultimate strength of the nanocomposites vary nonlinearly with the cohesive energy of the interface. The cohesive properties affect the stiffness of the interface zone, and in turn, influence the effective Young's modulus of composites. The competition between interfacial failure and weak phase damage results in an optimal cohesive parameter of the interface, at which the composite possesses the maximal ultimate strength. The obtained results provide useful guidelines for the design and optimisation of advanced nanocomposites with superior mechanical properties.
Ge growth on porous silicon: The effect of buffer porosity on the epilayer crystalline quality
Authors: Calabrese G. , Baricordi S. , Bernardoni P. , De Salvador D. , Ferroni M. , Guidi V. , Morandi V. , Vincenzi D.
Published: September 2014

We report on the epitaxial growth of Ge virtual substrates directly on Si (001) and on different porosity porous silicon (pSi) buffers. Obtained results indicate that Ge grown on low porosity (22%) pSi buffer has a better crystalline quality compared to Ge grown on bulk Si and on higher porosity buffers. This result is attributed to the compliant nature of pSi and to its reduced Young's modulus, which leads to plastic tensile deformation of the 22% porosity buffer under the in-plane tensile stress introduced by Ge lattice. The same result is not observed for higher porosity buffers, this effect being attributed to the higher buffer fragility. A low porosity pSi layer can hence be used as buffer for the growth of Ge on Si virtual substrates with reduced dislocation content and for the growth of Ge based devices or the successive integration of III-V semiconductors on Si.
High-contrast electro-optic modulation of spatial light induced by graphene-integrated Fabry-Pérot microcavity
Authors: Zeng Chao , Guo Jing , Liu Xueming
Published: September 2014

We have proposed a graphene-integrated Fabry-Pérot microcavity for efficient modulation of spatial light. A simplified theoretical model is established to analyze the performance of our system, and the calculated results agree well with the simulation results. It is shown that the plasmon-induced transparency (PIT) effect is achieved in the proposed microcavity and the central frequency of PIT window can be dynamically tuned by gate voltages. In particular, the PIT spectra exhibit extremely large modulation depths (∼90%) across a broad range of frequencies. The proposed ultracompact configuration demonstrates a type of cavity-induced high-contrast and frequency-selective electro-optic modulators, offering opportunities in exploiting active chip-integrated high-performance devices operating at frequencies from terahertz to mid-infrared.
A parallelogram-based compliant remote-center-of-motion stage for active parallel alignment
Authors: Qu Jianliang , Chen Weihai , Zhang Jianbin
Published: September 2014

Parallel alignment stage with remote-center-of-motion (RCM) is of key importance in precision out-of-plane aligning since it can eliminate the harmful lateral displacement generated at the output platform. This paper presents the development of a parallelogram-based compliant RCM stage for active parallel alignment. Different from conventional parallelogram-based RCM mechanism, the proposed stage is designed with compliant mechanisms, which endows the stage with many attractive merits when used in precision micro-/nanomanipulations. A symmetric double-parallelogram mechanism (SDPM) based on flexure hinges is developed as the rotary guiding component to realize desired RCM function. Due to the geometrical constraint of the SDPM, the operating space of the stage can be easily adjusted by bending the input links without loss of rotational precision. The stage is driven by a piezoelectric actuator and its output motion is measured by non-contact displacement sensors. Based on pseudo-rigid-body simplification method, the analytical models predicting kinematics, statics, and dynamics of the RCM stage have been established. Besides, the dimensional optimization is conducted in order to maximize the first resonance frequency of the stage. After that, finite element analysis is conducted to validate the established models and the prototype of the stage is fabricated for performance tests. The experimental results show that the developed RCM stage has a rotational range of 1.45 mrad while the maximum center shift of the RCM point is as low as 1 μm, which validate the effectiveness of the proposed scheme.
The motion of solid spherical particles falling in a cellular flow field at low Stokes number
Authors: Bergougnoux Laurence , Bouchet Gilles , Lopez Diego , Guazzelli Élisabeth
Published: September 2014

We present a jointed experimental and numerical study examining the influence of vortical structures on the settling of solid spherical particles under the action of gravity at low Stokes numbers. The two-dimensional model experiment uses electroconvection to generate a two-dimensional array of controlled vortices which mimics a simplified vortical flow. Particle image-velocimetry and tracking are used to examine the motion of the particles within this vortical flow. Particle motion is compared to the predictions of a numerical simulation inspired by the model equation developed by Maxey [“The motion of small spherical particles in a cellular flow field,” Phys. Fluids 30, 1915 (1987)].
Path induced coherent energy transfer in light-harvesting complexes in purple bacteria
Authors: Sun Kewei , Ye Jun , Zhao Yang
Published: September 2014

Features of path dependent energy transfer in a dual-ring light-harvesting (LH2) complexes (B850) system have been examined in detail systematically. The Frenkel-Dirac time dependent variational method with the Davydov D1 Ansatz is employed with detailed evolution of polaron dynamics in real space readily obtained. It is found that the phase of the transmission amplitude through the LH2 complexes plays an important role in constructing the coherent excitonic energy transfer. It is also found that the symmetry breaking caused by the dimerization of bacteriochlorophylls and coherence or correlation between two rings will be conducive in enhancing the exciton transfer efficiency.
Excitation energies from particle-particle random phase approximation: Davidson algorithm and benchmark studies
Authors: Yang Yang , Peng Degao , Lu Jianfeng , Yang Weitao
Published: September 2014

The particle-particle random phase approximation (pp-RPA) has been used to investigate excitation problems in our recent paper [Y. Yang, H. van Aggelen, and W. Yang, J. Chem. Phys. 139, 224105 (2013)]. It has been shown to be capable of describing double, Rydberg, and charge transfer excitations, which are challenging for conventional time-dependent density functional theory (TDDFT). However, its performance on larger molecules is unknown as a result of its expensive O(N6) scaling. In this article, we derive and implement a Davidson iterative algorithm for the pp-RPA to calculate the lowest few excitations for large systems. The formal scaling is reduced to O(N4), which is comparable with the commonly used configuration interaction singles (CIS) and TDDFT methods. With this iterative algorithm, we carried out benchmark tests on molecules that are significantly larger than the molecules in our previous paper with a reasonably large basis set. Despite some self-consistent field convergence problems with ground state calculations of (N − 2)-electron systems, we are able to accurately capture lowest few excitations for systems with converged calculations. Compared to CIS and TDDFT, there is no systematic bias for the pp-RPA with the mean signed error close to zero. The mean absolute error of pp-RPA with B3LYP or PBE references is similar to that of TDDFT, which suggests that the pp-RPA is a comparable method to TDDFT for large molecules. Moreover, excitations with relatively large non-HOMO excitation contributions are also well described in terms of excitation energies, as long as there is also a relatively large HOMO excitation contribution. These findings, in conjunction with the capability of pp-RPA for describing challenging excitations shown earlier, further demonstrate the potential of pp-RPA as a reliable and general method to describe excitations, and to be a good alternative to TDDFT methods.
Effects of weak noise on oscillating flows: Linking quality factor, Floquet modes, and Koopman spectrum
Authors: Bagheri Shervin
Published: September 2014

Many fluid flows, such as bluff body wakes, exhibit stable self-sustained oscillations for a wide range of parameters. Here we study the effect of weak noise on such flows. In the presence of noise, a flow with self-sustained oscillations is characterized not only by its period, but also by the quality factor. This measure gives an estimation of the number of oscillations over which periodicity is maintained. Using a recent theory [P. Gaspard, J. Stat. Phys. 106, 57 (2002)], we report on two observations. First, for weak noise the quality factor can be approximated using a linear Floquet analysis of the deterministic system; its size is inversely proportional to the inner-product between first direct and adjoint Floquet vectors. Second, the quality factor can readily be observed from the spectrum of evolution operators. This has consequences for Koopman/Dynamic mode decomposition analyses, which extract coherent structures associated with different frequencies from numerical or experimental flows. In particular, the presence of noise induces a damping on the eigenvalues, which increases quadratically with the frequency and linearly with the noise amplitude.
Theoretical vibrational sum-frequency generation spectroscopy of water near lipid and surfactant monolayer interfaces. II. Two-dimensional spectra
Authors: Roy S. , Gruenbaum S. M. , Skinner J. L.
Published: September 2014

The structural stability and function of biomolecules is strongly influenced by the dynamics and hydrogen bonding of interfacial water. Understanding and characterizing the dynamics of these water molecules require a surface-sensitive technique such as two-dimensional vibrational sum-frequency generation (2DSFG) spectroscopy. We have combined theoretical 2DSFG calculations with molecular dynamics simulations in order to investigate the dynamics of water near different lipid and surfactant monolayer surfaces. We show that 2DSFG can distinguish the dynamics of interfacial water as a function of the lipid charge and headgroup chemistry. The dynamics of water is slow compared to the bulk near water-zwitterionic and water-anionic interfaces due to conformational constraints on interfacial water imposed by strong phosphate-water hydrogen bonding. The dynamics of water is somewhat faster near water-cationic lipid interfaces as no such constraint is present. Using hydrogen bonding and rotational correlation functions, we characterize the dynamics of water as a function of the distance from the interface between water and zwitterionic lipids. We find that there is a transition from bulk-like to interface-like dynamics approximately 7 Å away from a zwitterionic phosphatidylcholine monolayer surface.
Surface band bending and band alignment of plasma enhanced atomic layer deposited dielectrics on Ga- and N-face gallium nitride
Authors: Yang Jialing , Eller Brianna S. , Nemanich Robert J.
Published: September 2014

The effects of surface pretreatment, dielectric growth, and post deposition annealing on interface electronic structure and polarization charge compensation of Ga- and N-face bulk GaN were investigated. The cleaning process consisted of an ex-situ wet chemical NH4OH treatment and an in-situ elevated temperature NH3 plasma process to remove carbon contamination, reduce oxygen coverage, and potentially passivate N-vacancy related defects. After the cleaning process, carbon contamination decreased below the x-ray photoemission spectroscopy detection limit, and the oxygen coverage stabilized at ∼1 monolayer on both Ga- and N-face GaN. In addition, Ga- and N-face GaN had an upward band bending of 0.8 ± 0.1 eV and 0.6 ± 0.1 eV, respectively, which suggested the net charge of the surface states and polarization bound charge was similar on Ga- and N-face GaN. Furthermore, three dielectrics (HfO2, Al2O3, and SiO2) were prepared by plasma-enhanced atomic layer deposition on Ga- or N-face GaN and annealed in N2 ambient to investigate the effect of the polarization charge on the interface electronic structure and band offsets. The respective valence band offsets of HfO2, Al2O3, and SiO2 with respect to Ga- and N-face GaN were 1.4 ± 0.1, 2.0 ± 0.1, and 3.2 ± 0.1 eV, regardless of dielectric thickness. The corresponding conduction band offsets were 1.0 ± 0.1, 1.3 ± 0.1, and 2.3 ± 0.1 eV, respectively. Experimental band offset results were consistent with theoretical calculations based on the charge neutrality level model. The trend of band offsets for dielectric/GaN interfaces was related to the band gap and/or the electronic part of the dielectric constant. The effect of polarization charge on band offset was apparently screened by the dielectric-GaN interface states.
Surface diffusion controlled formation of high quality vertically aligned InN nanotubes
Authors: Wei Pai-Chun , Chen Li-Chyong , Chen Kuei-Hsien
Published: September 2014

We present a successful growth of high quality indium nitride (InN) nanotubes via surface diffusion controlled processes. The nanotubes exhibit high aspect ratios and high homogeneity in length and wall thickness. Analysis of the growth suggests that the nucleation of hexagonal InN platelets followed by thermally induced surface diffusion of indium along the walls of templates, with simultaneous nitridation, forms the InN nanotubes. The nanotubes effectively bear the lateral dimensions of the starting platelet. The crystal structure characterization by transmission electron microscopy and X-ray diffraction reveals their wurtzite structure and c (002) growth direction. Photoluminescence spectra of the molecular beam epitaxy-grown InN nanotubes exhibit an optical band gap near 0.68 eV at room temperature, which implies the conspicuous reduction of band filling effect caused by the impurities incorporations.
Thermodynamics, compressibility, and phase diagram: Shock compression of supercritical fluid xenon
Authors: Zheng J. , Chen Q. F. , Gu Y. J. , Chen Z. Y. , Li C. J.
Published: September 2014

Supercritical fluids have intriguing behaviors at extreme pressure and temperature conditions, prompting the need for thermodynamic properties of supercritical fluid xenon (SCF) under shock compression. Double-shock experimental data on SCF xenon in the 140 GPa pressure range were directly measured by means of a multi-channel pyrometer and a Doppler-pins-system. It entered the so-called warm dense region. We found that the shock compressed SCF Xe had higher dynamic compression and higher number density than that of liquid Xe at same shock pressure. The larger compressibility of SCF Xe in our experiments could be explained that the increase of electronic excitations and ionizations leaded to a large drop of thermal pressure and a softening of Hugoniot. The high pressure phase diagram of xenon was depicted with the aid of the degeneracy, coupling parameter, and current available experiments on the pressure-temperature plane.
Formation of high-quality oxide/Ge1−xSnx interface with high surface Sn content by controlling Sn migration
Authors: Kato Kimihiko , Taoka Noriyuki , Asano Takanori , Yoshida Teppei , Sakashita Mitsuo , Nakatsuka Osamu , Zaima Shigeaki
Published: September 2014

In this paper, we investigated how Sn migrated during annealing for Ge1−xSnx at its surface and in its interior, as well as the Ge oxide formation on Ge1−xSnx with controlling surface oxidation. After oxidation at 400 °C, X-ray photoelectron spectroscopy and X-ray diffraction measurements revealed Sn migration from inside the epitaxial Ge1−xSnx layer to its surface. Annealing was not the primary cause of significant Sn migration; rather, it was caused mostly by oxidation near the Ge1−xSnx surface. This process formed a Ge1−xSnx oxide with a very high Sn content of 30%, inducing a wide hysteresis loop in the capacitance–voltage characteristics of its corresponding MOS device. We also found that forming a thin GeO2 layer by using a deposition method that controls Ge surface oxidation produced low densities of interface states and slow states. From these results, we conclude that controlling Sn migration is critical to forming a high-quality Ge1−xSnx gate stack.
Effect of magnetic islands on lower hybrid current drive in experimental advanced superconductor tokamak plasma with circular cross section
Authors: Li Xinxia , Xiang Nong , Shi Xingjian
Published: September 2014

The lower hybrid wave current drive (LHCD) in the presence of magnetic islands in Tokamak plasma with the circular cross section is studied numerically. The emergence of magnetic island is considered as a perturbation characterized by the perturbed magnetic flux near the resonant surface. By taking the perturbed magnetic field into account in the lower hybrid simulation code, the wave propagation, power deposition, and current drive are investigated using typical Experimental Advanced Superconductor Tokamak (EAST) L- and H-modes discharge parameters. The simulation results show that the wave propagation, power deposition, and current drive are significantly affected by the existence of magnetic island. Due to the H-mode pedestal, the effect of magnetic islands on the LHCD in EAST H-mode discharge is more significant than that in the L-mode discharge.