bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors associated with response, survival, and limb salvage in patients undergoing isolated limb infusion
Authors: Steinman Jonathan , Ariyan Charlotte , Rafferty Brian , Brady Mary S.
Published: December 2013

Background

Isolated limb infusion (ILI) is a percutaneous method of delivering regional chemotherapy to patients with recurrent tumors of the extremity. This study determines predictors of response, survival, and limb salvage.

Methods

Single institution data from a prospective clinical trial and subsequent ILI experience were reviewed. Limb tumor burden was assessed in melanoma patients with “high” (≥10 lesions or one lesion >3 cm) or “low” burden (<10 lesions and no lesion >3 cm). Response was assessed at 3 months from ILI.

Results

Between 1999 and 2011, 62 patients underwent ILI (58 melanoma, 2 Merkel cell carcinoma (MCC), 2 soft tissue sarcoma (STS)). Low tumor burden patients had more complete responses (CR) (11/23, 48%) than high tumor burden (3/32, 9%, P < 0.001); they had higher 5‐year survival (69% vs. 29%, P = .007). Five‐year survival rates based on response: 91% CR, 53% partial response (PR), 25% less than PR (P = 0.042, CR vs. PR).

7 patients (11%) underwent amputation due to disease progression; 3 had prior CR or PR.

Conclusions

Low tumor burden is a significant predictor of response in melanoma patients. Response to ILI is a significant predictor of survival. Progression of limb disease requiring amputation is not associated with any factors. J. Surg. Oncol. 2014 109:405–409. © 2013 Wiley Periodicals, Inc.
Prenatal ultrasound evaluation of fetal Hb Bart's disease among pregnancies at risk at 11 to 14 weeks of gestation
Authors: Sirichotiyakul Supatra , Luewan Suchaya , Srisupundit Kasemsri , Tongprasert Fuanglada , Tongsong Theera
Published: December 2013

Objective

The objective of this article is to evaluate the efficacy of the first trimester sonomarkers (11–14 weeks) in predicting hemoglobin (Hb) Bart's disease among fetuses at risk

Materials and Methods

Prospective analysis was conducted on pregnancies at risk of fetal Hb Bart's disease at 11 to 14 weeks of gestation. Sonographic markers including cardiothoracic (CT) ratio, peak systolic velocity of the middle cerebral artery (MCA‐PSV), placental thickness, and nuchal translucency were prospectively assessed and recorded. The definite diagnosis of fetal Hb Bart's disease was based on DNA analysis (chorionic villus sampling) or subsequent fetal Hb typing (high‐performance liquid chromatography; cordocentesis).

Results

Among 104 pregnancies at risk with complete sonographic assessment at 11 to 14 weeks of gestation, 30 fetuses were finally proven to be affected. The CT ratio gave the highest sensitivity, 93.3%, with specificity of 93.2%, followed by placental thickness and MCA‐PSV, respectively. Nuchal translucency had a very low sensitivity of 16.7%. The combination of CT ratio and MCA‐PSV increased the sensitivity to 96.7% but somewhat compromise specificity.

Conclusions

At 11 to 14 weeks of gestation, sonographic markers can effectively differentiate affected from unaffected pregnancies. The most sensitive marker was CT ratio plus MCA‐PSV. Of couples at risk with no any sonographic markers, the risk of having an affected fetus is nearly eliminated. © 2013 John Wiley & Sons, Ltd.
Relation between light trapping and surface topography of plasma textured crystalline silicon wafers
Authors: Souren F. M. M. , Rentsch J. , van de Sanden M. C. M.
Published: December 2013

Currently, in the photovoltaic industry, wet chemical etching technologies are used for saw damage removal and surface texturing. Alternative to wet chemical etching is plasma etching. However, as for example, the linear microwave plasma technique, developed by Roth&Rau, has not been implemented in the photovoltaic industry for etching, because of the very low etch rate (<1 µm/min) and the high cost of ownership related to the etching process. In this study, different front surface textured crystalline silicon wafers obtained by means of the linear microwave plasma technique and the expanding thermal plasma technique are investigated in terms of weighted reflection by using reflectometry (250–1200 nm) to study the optical properties of the textures in detail. In addition, atomic force microscopy is used to measure the surface topography to determine statistical roughness parameters, as presented in this paper. Effective light trapping can be obtained by multiple reflections as well as by a graded layer, which leads to a diffuse front surface, or a combination of both. A graded layer can be described as a smooth transition with increasing refractive index from air to silicon with typical thickness of (200 ± 50) nm. We have found that the average plane tilt angle correlates to the measured weighted reflection. Moreover, we can determine from the aspect ratio whether the light trapping is effective by multiple reflections. From the roughness exponent, which is a measure for the micro roughness, we can determine whether the light trapping is effective by a graded layer. Copyright © 2013 John Wiley & Sons, Ltd.
Activated 5′flanking region of NANOGP8 in a self‐renewal environment is associated with increased sphere formation and tumor growth of prostate cancer cells
Authors: Zhang Kai , Fowler Marcie , Glass Jonathan , Yin Hong
Published: December 2013

INTRODUCTION

NANOGP8 is a retrogene which encodes a full‐length protein similar to the NANOG1 gene. The expression of NANOGP8 has been documented in several cancers and is related to cell proliferation and tumor development. However, the regulation of NANOGP8 expression has not been investigated. Therefore, the role of NANOGP8 in cell proliferation has not been completely understood.

METHODS

We evaluate the expression of NANOG1 and NANOGP8 in prostate cancer cell lines and primary cultures of prostate tissues. We investigate clonogenicity, sphere formation, and xenograft tumor growth of prostate cancer cells with an activated 5′flanking region of NANOGP8. We examine the role of NANOGP8 in cell cycle progression.

RESULTS

In the prostate cells the NANOG RNA was transcribed from NANOGP8 and not from NANOG1. Cells with the activated 5′flanking region of NANOGP8 exhibited enhanced clonogenicity, sphere formation, and xenograft tumor growth. The sphere culture and tumor initiation mouse mode promoted the activation of the 5′flanking region of NANOGP8. Forced expression of NANOGP8 increased the entry into the cell cycle.

DISCUSSION

In prostate cells NANOGP8 is a predominant molecule of NANOG. The activation of 5′flanking sequence of NANOGP8 could play a role in the regulation of the stem‐like properties of cancer stem cells and prostate tumor initiation and development. The microenvironment favoring cancer stem cells could promote the activation of the 5′flanking region of NANOGP8. Prostate 74:381–394, 2014. © 2013 Wiley Periodicals, Inc.
Suppression of Lipopolysaccharide‐stimulated Cytokine/Chemokine Production in Skin Cells by Sandalwood Oils and Purified α‐santalol and β‐santalol
Authors: Sharma M. , Levenson C. , Bell R. H. , Anderson S. A. , Hudson J. B. , Collins C. C. , Cox M. E.
Published: December 2013

Medicinally, sandalwood oil (SO) has been attributed with antiinflammatory properties; however, mechanism(s) for this activity have not been elucidated. To examine how SOs affect inflammation, cytokine antibody arrays and enzyme‐linked immunosorbent assays were used to assess changes in production of cytokines and chemokines by co‐cultured human dermal fibroblasts and neo‐epidermal keratinocytes exposed to lipopolysaccharides and SOs from Western Australian and East Indian sandalwood trees or to the primary SO components, α‐santalol and β‐santalol. Lipopolysaccharides stimulated the release of 26 cytokines and chemokines, 20 of which were substantially suppressed by simultaneous exposure to either of the two sandalwood essential oils and to ibuprofen. The increased activity of East Indian SO correlated with increased santalol concentrations. Purified α‐santalol and β‐santalol equivalently suppressed production of five indicator cytokines/chemokines at concentrations proportional to the santalol concentrations of the oils. Purified α‐santalol and β‐santalol also suppressed lipopolysaccharide‐induced production of the arachidonic acid metabolites, prostaglandin E2, and thromboxane B2, by the skin cell co‐cultures. The ability of SOs to mimic ibuprofen non‐steroidal antiinflammatory drugs that act by inhibiting cyclooxygenases suggests a possible mechanism for the observed antiinflammatory properties of topically applied SOs and provides a rationale for use in products requiring antiinflammatory effects. Copyright © 2013 John Wiley & Sons, Ltd.
Acute, Reproductive Toxicity and Two‐generation Teratology Studies of a Standardized Quassinoid‐rich Extract of Eurycoma longifolia Jack in Sprague–Dawley Rats
Authors: Low Bin‐Seng , Das Prashanta Kumar , Chan Kit‐Lam
Published: December 2013

The roots of Eurycoma longifolia Jack are popularly sought as herbal medicinal supplements to improve libido and general health amongst the local ethnic population. The major quassinoids of E. longifolia improved spermatogenesis and fertility but toxicity studies have not been well documented. The reproductive toxicity, two generation of foetus teratology and the up‐and‐down acute toxicity were investigated in Sprague–Dawley rats orally treated with quassinoid‐rich E. longifolia extract (TAF273). The results showed that the median lethal dose (LD50) of TAF273 for female and male rats was 1293 and >2000 mg/kg, respectively. Fertility index and litter size of the TAF273 treated were significantly increased when compared with those of the non‐treated animals. The TAF273‐treated dams decreased in percentage of pre‐implantation loss, post‐implantation loss and late resorption. No toxic symptoms were observed on the TAF273‐treated pregnant female rats and their foetuses were normal. The no‐observed adverse effect level (NOAEL) obtained from reproductive toxicity and teratology studies of TAF273 in rats was 100 mg/kg body weight/day, being more than 10‐fold lower than the LD50 value. Thus, any human dose derived from converting the rat doses of 100 mg/kg and below may be considered as safe for further clinical studies. Copyright © 2013 John Wiley & Sons, Ltd.
Diagnostic Performance of Ultrasound for Macroscopic Hematuria in the Era of Multidetector Computed Tomography Urography
Authors: Rhéaume-Lanoie Julien , Lepanto Luigi , Fradet Vincent , Billiard Jean-Sébastien , Tang An
Published: December 2013

Purpose

The objective of this study was to evaluate the diagnostic performance of ultrasound for detecting urinary tract neoplasm in the setting of macroscopic hematuria by using multidetector computed tomography urography (MDCTU) and cystoscopy as the reference standard.

Methods

This retrospective study was approved by our institutional review board. Patients with macroscopic hematuria who were investigated with an abdominal or renal ultrasound, an MDCTU, and a cystoscopy between January 2007 and December 2009, were eligible (95 patients). Exclusion criteria were time interval >12 months between index and reference tests or the absence of histopathologic proof of malignancy. Ultrasound results of the remaining 86 patients were collected and compared with the reference standard test, which was the combination of MDCTU for the assessment of upper urinary tract and cystoscopy for assessment of the lower urinary tract. The final diagnosis of neoplasm was based on pathologic findings.

Results

Urinary tract neoplasm was diagnosed in 20% of the patients (17/86). Sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios of ultrasound for detecting urinary tract neoplasms were 35.3% (6/17), 89.9% (62/69), 46.2% (6/13), 84.9% (62/73), 3.48 (95% confidence interval, 1.34-9.02), and 0.72 (95% confidence interval, 0.5-1.3), respectively.

Conclusion

Sensitivity of ultrasound for the evaluation of macroscopic hematuria in the era of MDCTU is lower than expected. Results of our study suggest that patients with macroscopic hematuria should undergo MDCTU as first-line imaging modality, with little added benefit from ultrasound.
Diphenyleneiodonium, an inhibitor of NOXes and DUOXes, is also an iodide‐specific transporter
Authors: Massart C. , Giusti N. , Beauwens R. , Dumont J.E. , Miot F. , Sande J. Van
Published: December 2013

NADPH oxidases (NOXes) and dual oxidases (DUOXes) generate O2
.− and H2O2. Diphenyleneiodonium (DPI) inhibits the activity of these enzymes and is often used as a specific inhibitor. It is shown here that DPI, at concentrations similar to those which inhibit the generation of O2 derivatives, activated the efflux of radioiodide but not of its analog 99mTcO4
− nor of the K+ cation mimic 86Rb+ in thyroid cells, in the PCCl3 rat thyroid cell line and in COS cell lines expressing the iodide transporter NIS. Effects obtained with DPI, especially in thyroid cells, should therefore be interpreted with caution.
Quaternary structural partitioning within the rigid Tarim plate inferred from magnetostratigraphy and sedimentation rate in the eastern Tarim Basin in China
Authors: Chang Hong , An Zhisheng , Liu Weiguo , Ao Hong , Qiang Xiaoke , Song Yougui , Lai Zhongping
Published: December 2013

It has been proposed that within the Tarim Basin tectonic activity has been limited since Triassic time. However, on the basis of magnetostratigraphy from the eastern Tarim Basin, which defines the chronology of sedimentation and structural evolution of the basin, we show that the basin interior has been uplifted and partitioned during Quaternary. The magnetostratigraphy was constructed from 2228 samples that yielded acceptable inclination values. Characteristic remnant magnetization (ChRM) with both normal (N1–N11) and reversed (R1–R11) polarity was isolated by thermal demagnetization. The data correlate best with polarity chrons C3r to C1n, which range from 5.39 Ma to recent on the geological time scale 2004 (GTS2004). An abrupt decrease in the sedimentation rate is observed at 1.77 Ma in the Ls1 core. This change does not overlap with known Pleistocene climate-change events. We attribute this sedimentation rate decrease to a structurally controlled local decrease in accommodation space where basin basement uplifts occur. This period of sedimentary environmental change reveals that structural partitioning in the basement of the Tarim Basin occurred since ~ 1.77 Ma, and we speculate that tilting of the Southeast Uplift (a sub-basin unit) within the Tarim Basin began in early Pleistocene time.
Functionalized meso/macro-porous single ion polymeric electrolyte for applications in lithium ion batteries
Authors: Rohan Rupesh , Sun Yubao , Cai Weiwei , Pareek Kapil , Zhang Yunfeng , Xu Guodong , Cheng Hansong
Published: December 2013

We report a method to significantly enhance the conductivity of lithium ions in a polymeric lithium salt membrane by introducing functionalized meso/macro-pores to accommodate a mixture of organic solvents in the polymer matrix.
Two-frequency heating technique at the 18 GHz electron cyclotron resonance ion source of the National Institute of Radiological Sciences
Authors: Biri S. , Kitagawa A. , Muramatsu M. , Drentje A. G. , Rácz R. , Yano K. , Kato Y. , Sasaki N. , Takasugi W.
Published: December 2013

The two-frequency heating technique was studied to increase the beam intensities of highly charged ions provided by the high-voltage extraction configuration (HEC) ion source at the National Institute of Radiological Sciences (NIRS). The observed dependences on microwave power and frequency suggested that this technique improved plasma stability but it required precise frequency tuning and more microwave power than was available before 2013. Recently, a new, high-power (1200 W) wide band-width (17.1–18.5 GHz) travelling-wave-tube amplifier (TWTA) was installed. After some single tests with klystron and TWT amplifiers the simultaneous injection of the two microwaves has been successfully realized. The dependence of highly charged ions (HCI) currents on the superposed microwave power was studied by changing only the output power of one of the two amplifiers, alternatively. While operating the klystron on its fixed 18.0 GHz, the frequency of the TWTA was swept within its full limits (17.1–18.5 GHz), and the effect of this frequency on the HCI-production rate was examined under several operation conditions. As an overall result, new beam records of highly charged argon, krypton, and xenon beams were obtained at the NIRS-HEC ion source by this high-power two-frequency operation mode.
Improved design of proton source and low energy beam transport line for European Spallation Source
Authors: Neri L. , Celona L. , Gammino S. , Mascali D. , Castro G. , Torrisi G. , Cheymol B. , Ponton A. , Galatà A. , Patti G. , Gozzo A. , Lega L. , Ciavola G.
Published: December 2013

The design update of the European Spallation Source (ESS) accelerator is almost complete and the construction of the prototype of the microwave discharge ion source able to provide a proton beam current larger than 70 mA to the 3.6 MeV Radio Frequency Quadrupole (RFQ) started. The source named PS-ESS (Proton Source for ESS) was designed with a flexible magnetic system and an extraction system able to merge conservative solutions with significant advances. The ESS injector has taken advantage of recent theoretical updates and new plasma diagnostics tools developed at INFN-LNS (Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare). The design strategy considers the PS-ESS and the low energy beam transport line as a whole, where the proton beam behaves like an almost neutralized non-thermalized plasma. Innovative solutions have been used as hereinafter described. Thermo-mechanical optimization has been performed to withstand the chopped beam and the misaligned focused beam over the RFQ input collimator; the results are reported here.
Exploration of the intrinsic inertial response of ferroelectric domain walls via molecular dynamics simulations
Authors: Liu Shi , Grinberg Ilya , Rappe Andrew M.
Published: December 2013

The motion of ferroelectric domain walls (DWs) is critical for various applications of ferroelectric materials. One important question that is of interest both scientifically and technologically, is whether the ferroelectric DW has significant inertial response. To address this problem, we performed canonical ensemble molecular dynamics simulations of 180° and 90° DWs under applied electric fields. Examination of the evolution of the polarization and local structure of DWs reveals that they stop moving immediately after the removal of electric field. Thus, our computational study shows that ferroelectric DWs do not have significant intrinsic inertial response.
Spin-free Dirac-Coulomb calculations augmented with a perturbative treatment of spin-orbit effects at the Hartree-Fock level
Authors: Cheng Lan , Stopkowicz Stella , Gauss Jürgen
Published: December 2013

A perturbative approach to compute second-order spin-orbit (SO) corrections to a spin-free Dirac-Coulomb Hartree-Fock (SFDC-HF) calculation is suggested. The proposed scheme treats the difference between the DC and SFDC Hamiltonian as perturbation and exploits analytic second-derivative techniques. In addition, a cost-effective scheme for incorporating relativistic effects in high-accuracy calculations is suggested consisting of a SFDC coupled-cluster treatment augmented by perturbative SO corrections obtained at the HF level. Benchmark calculations for the hydrogen halides HX, X = F-At as well as the coinage-metal fluorides CuF, AgF, and AuF demonstrate the accuracy of the proposed perturbative treatment of SO effects on energies and electrical properties in comparison with the more rigorous full DC treatment. Furthermore, we present, as an application of our scheme, results for the electrical properties of AuF and XeAuF.
Analysis and decoupling control of a permanent magnet spherical actuator
Authors: Zhang Liang , Chen Weihai , Liu Jingmeng , Wu Xingming
Published: December 2013

This paper presents the analysis and decoupling control of a spherical actuator, which is capable of performing three degree-of-freedom motion in one joint. The proposed actuator consists of a rotor with multiple PM (Permanent Magnet) poles in a circle and a stator with circumferential coils in three layers. Based on this actuator design, a decoupling control approach is developed. Unlike existing control methods that each coil is responsible for both the spinning and tilting motion, the proposed control strategy specifies the function of each coil. Specifically, the spinning motion is governed by the middle layer coils with a step control approach; while the tilting motion is regulated by upper and lower coils with a computed torque control method. Experiments have been conducted on the prototype to verify the validity of the design procedure, and the experimental results demonstrate the effectiveness of the analysis and control strategy.
Plasma ignition and steady state simulations of the Linac4 H− ion source
Authors: Mattei S. , Ohta M. , Yasumoto M. , Hatayama A. , Lettry J. , Grudiev A.
Published: December 2013

The RF heating of the plasma in the Linac4 H− ion source has been simulated using a particle-in-cell Monte Carlo collision method. This model is applied to investigate the plasma formation starting from an initial low electron density of 1012 m−3 and its stabilization at 1018 m−3. The plasma discharge at low electron density is driven by the capacitive coupling with the electric field generated by the antenna, and as the electron density increases the capacitive electric field is shielded by the plasma and induction drives the plasma heating process. Plasma properties such as e−/ion densities and energies, sheath formation, and shielding effect are presented and provide insight to the plasma properties of the hydrogen plasma.
Comparative analysis of continuous-wave surface-plasma negative ion sources with various discharge geometry
Authors: Belchenko Yu , Sanin A. , Sotnikov O.
Published: December 2013

Negative ion extraction from continuous-wave (CW) magnetron and semiplanotron discharges was studied and it was compared with that for the source with Penning electrode geometry. The CW negative ion beam up current to 13 mA was extracted from the magnetron source with emission aperture of 3.5 mm in diameter, while the beam with current up to 8 mA was obtained from the semiplanotron source modification. Characteristics of CW magnetron and semiplanotron sources are presented and analyzed.
Hematocrit and flow rate regulate the adhesion of platelets to von Willebrand factor
Authors: Chen Hsieh , Angerer Jennifer I. , Napoleone Marina , Reininger Armin J. , Schneider Stefan W. , Wixforth Achim , Schneider Matthias F. , Alexander-Katz Alfredo
Published: December 2013

Primary hemostasis and blood clotting is known to be influenced by the red blood cell volume fraction (hematocrit) in blood. Depressed or elevated levels of red blood cells can lead to vascular perfusion problems ranging from bleeding to thrombus formation. The early stage of hemostasis and thus blood clotting in all vessel sections from the arterial to the venous system involves the adhesion of platelets to von Willebrand factor. Here we present experimental and theoretical results showing that the adhesion probability of platelets to von Willebrand factor is strongly and nonlinearly dependent on hematocrit and flow rate. Interestingly, the actual binding forces are not markedly different, which suggest that the origin of such behavior is in the distribution of platelets. Using hydrodynamic simulations of a simple model, we explicitly show that the higher the hematocrit and the flow rate, the larger the amount of platelets residing close to the wall. Our simulation results, which are in excellent agreement with the experimental observations, explain why such phenomena occur. We believe that the nonhomogeneous red blood cell distribution as well as the shear dependent hydrodynamic interaction is key for the accumulation of platelets on the vessel wall. The work we present here is an important step forward from our earlier work on single molecules and extends into the collective cellular behavior of whole blood. It sheds new light on the correlation between hematocrit and the initial steps in hemostasis and thrombosis, and outlines advances for the treatment of vascular diseases associated with high levels of red blood cells. These results are not only highly relevant for the field of hemostasis and the physics of blood clotting but are also of powerful impact in applied science most obviously in drug delivery and colloidal science.
Global and Koopman modes analysis of sound generation in mixing layers
Authors: Song G. , Alizard F. , Robinet J.-C. , Gloerfelt X.
Published: December 2013

It is now well established that linear and nonlinear instability waves play a significant role in the noise generation process for a wide variety of shear flows such as jets or mixing layers. In that context, the problem of acoustic radiation generated by spatially growing instability waves of two-dimensional subsonic and supersonic mixing layers are revisited in a global point of view, i.e., without any assumption about the base flow, in both a linear and a nonlinear framework by using global and Koopman mode decompositions. In that respect, a timestepping technique based on disturbance equations is employed to extract the most dynamically relevant coherent structures for both linear and nonlinear regimes. The present analysis proposes thus a general strategy for analysing the near-field coherent structures which are responsible for the acoustic noise in these configurations. In particular, we illustrate the failure of linear global modes to describe the noise generation mechanism associated with the vortex pairing for the subsonic regime whereas they appropriately explain the Mach wave radiation of instability waves in the supersonic regime. By contrast, the Dynamic Mode Decomposition (DMD) analysis captures both the near-field dynamics and the far-field acoustics with a few number of modes for both configurations. In addition, the combination of DMD and linear global modes analyses provides new insight about the influence on the radiated noise of nonlinear interactions and saturation of instability waves as well as their interaction with the mean flow.
Strain relaxation in graphene grown by chemical vapor deposition
Authors: Troppenz Gerald V. , Gluba Marc A. , Kraft Marco , Rappich Jörg , Nickel Norbert H.
Published: December 2013

The growth of single layer graphene by chemical vapor deposition on polycrystalline Cu substrates induces large internal biaxial compressive strain due to thermal expansion mismatch. Raman backscattering spectroscopy and atomic force microscopy were used to study the strain relaxation during and after the transfer process from Cu foil to SiO2. Interestingly, the growth of graphene results in a pronounced ripple structure on the Cu substrate that is indicative of strain relaxation of about 0.76% during the cooling from the growth temperature. Removing graphene from the Cu substrates and transferring it to SiO2 results in a shift of the 2D phonon line by 27 cm−1 to lower frequencies. This translates into additional strain relaxation. The influence of the processing steps, used etching solution and solvents on strain, is investigated.
Lowest triplet $ {\bm ( n , \pi ^* )}$(n,π*) state of 2-cyclohexen-1-one: Characterization by cavity ringdown spectroscopy and quantum-chemical calculations
Authors: McAnally Michael O. , Zabronsky Katherine L. , Stupca Daniel J. , Phillipson Kaitlyn , Pillsbury Nathan R. , Drucker Stephen
Published: December 2013

The cavity ringdown (CRD) absorption spectrum of 2-cyclohexen-1-one (2CHO) was recorded over the range 401.5–410.5 nm in a room-temperature gas cell. The very weak band system (ε ⩽ 0.1 M−1 cm−1) in this spectral region is due to the T1(n, π*) ← S0 electronic transition. The $0^0_0$000 origin band was assigned to the feature observed at 24 558.8 ± 0.3 cm−1. We have assigned 46 vibronic transitions in a region extending from −200 to +350 cm−1 relative to the origin band. For the majority of these transitions, we have made corresponding assignments in the spectrum of the deuterated derivative 2CHO-2,6,6-d3. From the assignments, we determined fundamental frequencies for several vibrational modes in the T1(n, π*) excited state of 2CHO, including the lowest ring-twisting (99.6 cm−1) and ring-bending (262.2 cm−1) modes. These values compare to fundamentals of 122.2 cm−1 and 251.9 cm−1, respectively, determined previously for the isoconfigurational S1(n, π*) excited state of 2CHO and 99 cm−1 and 248 cm−1, respectively, for the S0 ground state. With the aid of quantum-mechanical calculations, we have also ascertained descriptions for these two modes, thereby resolving ambiguities appearing in the previous literature. The ring-twisting mode (ν39) contains a significant contribution from O=C–C=C torsion, whereas the ring-bending mode (ν38 in the ground state) involves mainly the motion of C-5 with respect to the plane containing the other heavy atoms. The CRD spectroscopic data for the T1(n, π*) state have allowed us to benchmark several computational methods for treating excited states, including time-dependent density functional theory and an equation-of-motion coupled cluster method. In turn, the computational results provide an explanation for observed differences in the T1(n, π*) vs. S1(n, π*) ring frequencies.
Nano-level instrumentation for analyzing the dynamic accuracy of a rolling element bearing
Authors: Yang Z. , Hong J. , Zhang J. , Wang M. Y. , Zhu Y.
Published: December 2013

The rotational performance of high-precision rolling bearings is fundamental to the overall accuracy of complex mechanical systems. A nano-level instrument to analyze rotational accuracy of high-precision bearings of machine tools under working conditions was developed. In this instrument, a high-precision (error motion < 0.15 μm) and high-stiffness (2600 N axial loading capacity) aerostatic spindle was applied to spin the test bearing. Operating conditions could be simulated effectively because of the large axial loading capacity. An air-cylinder, controlled by a proportional pressure regulator, was applied to drive an air-bearing subjected to non-contact and precise loaded axial forces. The measurement results on axial loading and rotation constraint with five remaining degrees of freedom were completely unconstrained and uninfluenced by the instrument's structure. Dual capacity displacement sensors with 10 nm resolution were applied to measure the error motion of the spindle using a double-probe error separation method. This enabled the separation of the spindle's error motion from the measurement results of the test bearing which were measured using two orthogonal laser displacement sensors with 5 nm resolution. Finally, a Lissajous figure was used to evaluate the non-repetitive run-out (NRRO) of the bearing at different axial forces and speeds. The measurement results at various axial loadings and speeds showed the standard deviations of the measurements’ repeatability and accuracy were less than 1% and 2%. Future studies will analyze the relationship between geometrical errors and NRRO, such as the ball diameter differences of and the geometrical errors in the grooves of rings.
Manipulating transport through a single-molecule junction
Authors: Sotthewes Kai , Heimbuch René , Zandvliet Harold J. W.
Published: December 2013

Molecular Electronics deals with the realization of elementary electronic devices that rely on a single molecule. For electronic applications, the most important property of a single molecule is its conductance. Here we show how the conductance of a single octanethiol molecule can be measured and manipulated by varying the contact's interspace. This mechanical gating of the single molecule junction leads to a variation of the conductance that can be understood in terms of a tunable image charge effect. The image charge effect increases with a decrease of the contact's interspace due to a reduction of the effective potential barrier height of 1.5 meV/pm.
Spin echo dynamics under an applied drift field in graphene nanoribbon superlattices
Authors: Prabhakar Sanjay , Melnik Roderick , Bonilla Luis L. , Raynolds James E.
Published: December 2013

We investigate the evolution of spin dynamics in graphene nanoribbon superlattices (GNSLs) with armchair and zigzag edges in the presence of a drift field. We determine the exact evolution operator and show that it exhibits spin echo phenomena due to rapid oscillations of the quantum states along the ribbon. The evolution of the spin polarization is accompanied by strong beating patterns. We also provide detailed analysis of the band structure of GNSLs with armchair and zigzag edges.
Diffusion in narrow channels on curved manifolds
Authors: Chacón-Acosta Guillermo , Pineda Inti , Dagdug Leonardo
Published: December 2013

In this work, we derive a general effective diffusion coefficient to describe the two-dimensional (2D) diffusion in a narrow and smoothly asymmetric channel of varying width, embedded on a curved surface, in the simple diffusion of non-interacting, point-like particles under no external field. To this end, we extend the generalization of the Kalinay–Percus' projection method [J. Chem. Phys. 122, 204701 (2005); Kalinay–Percus', Phys. Rev. E 74, 041203 (2006)] for the asymmetric channels introduced in [L. Dagdug and I. Pineda, J. Chem. Phys. 137, 024107 (2012)], to project the anisotropic two-dimensional diffusion equation on a curved manifold, into an effective one-dimensional generalized Fick-Jacobs equation that is modified according to the curvature of the surface. For such purpose we construct the whole expansion, writing the marginal concentration as a perturbation series. The lowest order in the perturbation parameter, which corresponds to the Fick-Jacobs equation, contains an additional term that accounts for the curvature of the surface. We explicitly obtain the first-order correction for the invariant effective concentration, which is defined as the correct marginal concentration in one variable, and we obtain the first approximation to the effective diffusion coefficient analogous to Bradley's coefficient [Phys. Rev. E 80, 061142 (2009)] as a function of the metric elements of the surface. In a straightforward manner, we study the perturbation series up to the nth order, and derive the full effective diffusion coefficient for two-dimensional diffusion in a narrow asymmetric channel, with modifications according to the metric terms. This expression is given as \documentclass[12pt]{minimal}\begin{document}$D(\xi )=\frac{D_0}{w^{\prime }(\xi )}\sqrt{\frac{g_1}{g_2}} \lbrace \arctan [\sqrt{\frac{g_2}{g_1}}(y^{\prime }_0(\xi )+\frac{w^{\prime }(\xi )}{2})]-\arctan [\sqrt{\frac{g_2}{g_1}}(y^{\prime }_0(\xi )-\frac{w^{\prime }(\xi )}{2})] \rbrace$\end{document}D(ξ)=D0w′(ξ)g1g2{arctan[g2g1(y0′(ξ)+w′(ξ)2)]−arctan[g2g1(y0′(ξ)−w′(ξ)2)]}, which is the main result of our work. Finally, we present two examples of symmetric surfaces, namely, the sphere and the cylinder, and we study certain specific channel configurations on these surfaces.
Cluster synchronization induced by one-node clusters in networks with asymmetric negative couplings
Authors: Zhang Jianbao , Ma Zhongjun , Zhang Gang
Published: December 2013

This paper deals with the problem of cluster synchronization in networks with asymmetric negative couplings. By decomposing the coupling matrix into three matrices, and employing Lyapunov function method, sufficient conditions are derived for cluster synchronization. The conditions show that the couplings of multi-node clusters from one-node clusters have beneficial effects on cluster synchronization. Based on the effects of the one-node clusters, an effective and universal control scheme is put forward for the first time. The obtained results may help us better understand the relation between cluster synchronization and cluster structures of the networks. The validity of the control scheme is confirmed through two numerical simulations, in a network with no cluster structure and in a scale-free network.
Compressive sensing based machine learning strategy for characterizing the flow around a cylinder with limited pressure measurements
Authors: Bright Ido , Lin Guang , Kutz J. Nathan
Published: December 2013

Compressive sensing is used to determine the flow characteristics around a cylinder (Reynolds number and pressure/flow field) from a sparse number of pressure measurements on the cylinder. Using a supervised machine learning strategy, library elements encoding the dimensionally reduced dynamics are computed for various Reynolds numbers. Convex L1 optimization is then used with a limited number of pressure measurements on the cylinder to reconstruct, or decode, the full pressure field and the resulting flow field around the cylinder. Aside from the highly turbulent regime (large Reynolds number) where only the Reynolds number can be identified, accurate reconstruction of the pressure field and Reynolds number is achieved. The proposed data-driven strategy thus achieves encoding of the fluid dynamics using the L2 norm, and robust decoding (flow field reconstruction) using the sparsity promoting L1 norm.
Polarity effects in the optical properties of hydrothermal ZnO
Authors: Allen M. W. , Heinhold R. , Miller P. , Henseler M. J. H. , Mendelsberg R. J. , Durbin S. M. , Reeves R. J.
Published: December 2013

Significant polarity-related differences in the near-band-edge photoluminescence from the Zn-polar and O-polar faces of hydrothermally grown ZnO single crystals, particularly in the ionized donor bound and free exciton recombination regions, were initially enhanced and then extinguished on annealing in oxygen at 400 °C and 600 °C, respectively. Polarity effects were also observed in the defect band emission with a structured green band associated with deep copper acceptor impurities appearing at lower annealing temperatures on the O-polar face. The loss of hydrogen is implicated in both these behaviors and in a sudden semiconductor-to-insulator transition between 200–300 °C.
Density of state effective mass and related charge transport properties in K-doped BiCuOSe
Authors: Sun Lee Dong , An Tae-Ho , Jeong Mahn , Choi Hyoung-Seuk , Soo Lim Young , Seo Won-Seon , Park Cheol-Hee , Park Chan , Park Hyung-Ho
Published: December 2013

We report the enhanced p-type conduction properties in BiCuOSe by doping of monovalent ions (K+). As compared with undoped BiCuOSe, simultaneous increase in both the carrier concentration and the Hall mobility was achieved in the K-doped BiCuOSe. The origin of the enhancement was discussed in terms of the two-band structure in the valence band of the BiCuOSe, and the density of state effective masses of the heavy (∼1.1 me) and light hole (∼0.18 me) were estimated by using Pisarenko relation.
InGaAsBi alloys on InP for efficient near- and mid-infrared light emitting devices
Authors: Jin Shirong , John Sweeney Stephen
Published: December 2013

We present the band parameters such as band gap, spin-orbit splitting energy, band offsets and strain of InGaAsBi on InP based on recent experimental data. It is shown that InGaAsBi is promising for near- and mid-infrared photonic devices operating from 0.3–0.8 eV (1.5–4 μm) on conventional InP substrates. We also show how bismuth may be used to form alloys whereby the spin-orbit splitting energy (ΔSO) is large and controllable and can, for example, be made larger than the band gap (Eg) thereby providing a means of suppressing non-radiative hot-hole producing Auger recombination and inter-valence band absorption both involving the spin-orbit band. This is expected to improve the high-temperature performance and thermal stability of light emitting devices.
Thermodynamic and mechanical stabilities of α- and β-Ta4AlC3 via first-principles investigations
Authors: Thawabi Hassan S. , Duong Thien , Arróyave Raymundo
Published: December 2013

Recently, it has been predicted that Ta4AlC3 is likely to exhibit an (α–β) polymorphic transformation at temperatures above 1873 K. However, recent X-ray diffraction and transmission electron microscopy experiments suggest on the other hand that the α phase remains stable up to temperatures close to the limit of experimental capabilities and no transition has yet been observed. While the matter has already been settled experimentally, in this work, we re-investigate the phase stability problem in Ta4AlC3 by using first-principles methods. The study was carried out by considering both thermodynamic and mechanical stabilities of the Ta4AlC3 polymorphs. Particularly, finite-temperature Gibbs free energies and elastic properties of the polymorphs were calculated using density functional theory. Calculation results reveal that the α phase continue to be stable even at temperatures exceeding 1875 K, which is in agreement with experimental results reported in literature.
Tin induced a-Si crystallization in thin films of Si-Sn alloys
Authors: Neimash V. , Poroshin V. , Shepeliavyi P. , Yukhymchuk V. , Melnyk V. , Kuzmich A. , Makara V. , Goushcha A. O.
Published: December 2013

Effects of tin doping on crystallization of amorphous silicon were studied using Raman scattering, Auger spectroscopy, scanning electron microscopy, and X-ray fluorescence techniques. Formation of silicon nanocrystals (2–4 nm in size) in the amorphous matrix of Si1−xSnx, obtained by physical vapor deposition of the components in vacuum, was observed at temperatures around 300 °C. The aggregate volume of nanocrystals in the deposited film of Si1−xSnx exceeded 60% of the total film volume and correlated well with the tin content. Formation of structures with ∼80% partial volume of the nanocrystalline phase was also demonstrated. Tin-induced crystallization of amorphous silicon occurred only around the clusters of metallic tin, which suggested the crystallization mechanism involving an interfacial molten Si:Sn layer.
Methane dissociative chemisorption and detailed balance on Pt(111): Dynamical constraints and the modest influence of tunneling
Authors: Donald S. B. , Navin J. K. , Harrison I.
Published: December 2013

A dynamically biased (d-) precursor mediated microcanonical trapping (PMMT) model of the activated dissociative chemisorption of methane on Pt(111) is applied to a wide range of dissociative sticking experiments, and, by detailed balance, to the methane product state distributions from the thermal associative desorption of adsorbed hydrogen with coadsorbed methyl radicals. Tunneling pathways were incorporated into the d-PMMT model to better replicate the translational energy distribution of the desorbing methane product from the laser induced thermal reaction of coadsorbed hydrogen and methyl radicals occurring near Ts = 395 K. Although tunneling is predicted to be inconsequential to the thermal dissociative chemisorption of CH4 on Pt(111) at the high temperatures of catalytic interest, once the temperature drops to 395 K the tunneling fraction of the reactive thermal flux reaches 15%, and as temperatures drop below 275 K the tunneling fraction exceeds 50%. The d-PMMT model parameters of {E0 = 58.9 kJ/mol, s = 2, ηv = 0.40} describe the apparent threshold energy for CH4/Pt(111) dissociative chemisorption, the number of surface oscillators involved in the precursor complex, and the efficacy of molecular vibrational energy to promote reaction, relative to translational energy directed along the surface normal. Molecular translations parallel to the surface and rotations are treated as spectator degrees of freedom. Transition state vibrational frequencies are derived from generalized gradient approximation-density functional theory electronic structure calculations. The d-PMMT model replicates the diverse range of experimental data available with good fidelity, including some new effusive molecular beam and ambient gas dissociative sticking measurements. Nevertheless, there are some indications that closer agreement between theory and experiments could be achieved if a surface efficacy less than one was introduced into the modeling as an additional dynamical constraint.
Phase diagram of ammonium nitrate
Authors: Dunuwille Mihindra , Yoo Choong-Shik
Published: December 2013

Ammonium Nitrate (AN) is a fertilizer, yet becomes an explosive upon a small addition of chemical impurities. The origin of enhanced chemical sensitivity in impure AN (or AN mixtures) is not well understood, posing significant safety issues in using AN even today. To remedy the situation, we have carried out an extensive study to investigate the phase stability of AN and its mixtures with hexane (ANFO–AN mixed with fuel oil) and Aluminum (Ammonal) at high pressures and temperatures, using diamond anvil cells (DAC) and micro-Raman spectroscopy. The results indicate that pure AN decomposes to N2, N2O, and H2O at the onset of the melt, whereas the mixtures, ANFO and Ammonal, decompose at substantially lower temperatures. The present results also confirm the recently proposed phase IV-IV′ transition above 17 GPa and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400°C.
Collective phase description of oscillatory convection
Authors: Kawamura Yoji , Nakao Hiroya
Published: December 2013

We formulate a theory for the collective phase description of oscillatory convection in Hele-Shaw cells. It enables us to describe the dynamics of the oscillatory convection by a single degree of freedom which we call the collective phase. The theory can be considered as a phase reduction method for limit-cycle solutions in infinite-dimensional dynamical systems, namely, stable time-periodic solutions to partial differential equations, representing the oscillatory convection. We derive the phase sensitivity function, which quantifies the phase response of the oscillatory convection to weak perturbations applied at each spatial point, and analyze the phase synchronization between two weakly coupled Hele-Shaw cells exhibiting oscillatory convection on the basis of the derived phase equations.
Atomic and electronic structure of Ni-Nb metallic glasses
Authors: Yuan C. C. , Yang Y.-F. , Xi X. K.
Published: December 2013

Solid state 93Nb nuclear magnetic resonance spectroscopy has been employed to investigate the atomic and electronic structures in Ni-Nb based metallic glass (MG) model system. 93Nb nuclear magnetic resonance (NMR) isotropic metallic shift of Ni60Nb35Sn5 has been found to be ∼100 ppm lower than that of Ni60Nb35Zr5 MG, which is correlated with their intrinsic fracture toughness. The evolution of 93Nb NMR isotropic metallic shifts upon alloying is clearly an electronic origin, as revealed by both local hyperfine fields analysis and first-principle computations. This preliminary result indicates that, in addition to geometrical considerations, atomic form factors should be taken into a description of atomic structures for better understanding the mechanical behaviors of MGs.
Low-temperature large reversible magnetocaloric effects of ErNi1-xCuxAl (x = 0.2, 0.5, 0.8) intermetallic compounds
Authors: Wang L. C. , Dong Q. Y. , Lu J. , Shao X. P. , Mo Z. J. , Xu Z. Y. , Sun J. R. , Hu F. X. , Shen B. G.
Published: December 2013

The magnetic properties and magnetocaloric effects of the ErNi1-xCuxAl (x = 0.2, 0.5, 0.8) compounds have been studied. The sample with x = 0.2 is found to be antiferromagnetic below the Néel temperature of TN = 4.6 K, while the sample x = 0.5 is simply ferromagnetic with a Curie temperature of TC = 5.8 K. In contrast, the sample x = 0.8 exhibits a short-range magnetic order, as revealed by AC magnetic measurements, and the transition temperature is 5.5 K. Large magnetic entropy change (ΔS) without hysteresis losses has been observed around the transition temperature for all the samples. The ΔS displays a peak between 4 K and 10 K, and the maximal values of ΔS are –22.6, –25.9, and –24.8 J/kg K for the field changes of 0-5 T, corresponding to the compositions of x = 0.2, x = 0.5, and x = 0.8, respectively. The large ΔS value as well as no hysteresis loss indicate that ErNi1-xCuxAl can be alternative candidates for magnetic refrigerant working at low temperature (<10 K).