bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulations of Asymmetric Flow Structures around a Moving Sphere at Moderate Reynolds Number
Authors: Young D.-L. , Wu C.-S. , Wu C. , Lin Y.-C.
Published: July 2015

The evolution of asymmetric leeward-side flow structures around a moving sphere in the viscous flow is investigated. Simulations are carried out to investigate the variations of vortex-ring system at the moderate Reynolds number. A parallel laboratory experiment is undertaken in this study. The sphere travels a certain distance at constant speed and then stops to collide with a wall. The motion of moving sphere in fluid is described by the hybrid Cartesian immersed boundary method. Drag forces behind the moving sphere are extremely substantial as the solid body falls through viscous fluid for comprehending the formation of wake flow. The dynamic behavior consists of growth and breakup of the vortices which depend on two specific moderate Reynolds numbers. The onset of physical instability in the wake is obviously affected at the Reynolds number of 800. The generated vortex-ring system rolls upward to compact the primary vortex ring and interact with the secondary vortex. An asymmetric generation of the pairs of vortices is developed since the physical instability effect leads to shed in the wake with the increasing Reynolds number. The results from numerical simulations are also conducted to exhibit good comparison with those from the laboratory experiment.
Investigations in Hydrostatic Planar Bearings Compensated by Tapered-Spool Restrictors II: Load Capacity and Static Stiffness
Authors: Kang Y. , Cheng H.-C. , Lee C.-W. , Hu S.-Y.
Published: July 2015

This study including two parts investigates the influence of design parameters of tapered-spool restrictors and hydrostatic planar bearing on static characteristics of load capacity and static stiffness. The former part provides guides for the design of single-action and double-action tapered-spool restrictors. This part provides design guides for planar hydrostatic bearing and for matching up with tapered-spool restrictor. The equations of flow continuity are utilized to determine the film thickness for open-type planar bearing and worktable displacement for closed-type planar bearing with respect to the recess pressure, respectively. The load capacity can be obtained by multiplying recess pressure by effective area of bearing pad. Furthermore, the static stiffness can be obtained by differentiating the recess pressure with respect to film thickness or worktable displacement. The finding results give that the usage range of recess pressure, and the availability ranges of design parameters of restrictor and bearing parameters. Which are found for getting the maximum stiffness.
Magnetohydrodynamic Free Convective Flow of Nanofluids Past an Oscillating Porous Flat Plate in A Rotating System with Thermal Radiation and Hall Effects
Authors: Das S. , Jana R.N. , Makinde O.D.
Published: July 2015

The unsteady magnetohydrodynamic free convective flow due to an oscillating porous flat plate in a rotating frame of reference are studied when thermal radiation and Hall currents are taken into consideration. The entire system rotates with a uniform angular velocity about an axis normal to the plate. A uniform magnetic field is applied along the normal to the plate directed into the fluid region. Copper, alumina and titania water nanofluids are considered. The governing equations are solved analytically by employing the small perturbation approximation. The numerical results for fluid velocity and temperature are presented graphically for the pertinent parameters and discussed in details.
Cholesterol and breast cancer risk: a systematic review and meta-analysis of prospective studies
Authors: Touvier Mathilde , Fassier Philippine , His Mathilde , Norat Teresa , Chan Doris S. M. , Blacher Jacques , Hercberg Serge , Galan Pilar , Druesne-Pecollo Nathalie , Latino-Martel Paule
Published: July 2015

The objective of the present study was to conduct the first systematic review and meta-analysis of prospective studies investigating the associations between total cholesterol (TC), HDL-cholesterol (HDL-C) and LDL-cholesterol (LDL-C) levels and the risk of breast cancer. Relevant studies were identified in PubMed (up to January 2014). Inclusion criteria were original peer-reviewed publications with a prospective design. Random-effects models were used to estimate summary hazard ratios (HR) and 95 % CI. Distinction was made between studies that did or did not exclude cancer cases diagnosed during the first years of follow-up, thereby eliminating potential preclinical bias. Overall, the summary HR for the association between TC and breast cancer risk was 0·97 (95 % CI 0·94, 1·00; dose–response per 1 mmol/l increment, thirteen studies), and that between HDL-C and breast cancer risk was 0·86 (95 % CI 0·69, 1·09; dose–response per 1 mmol/l increment, six studies), with high heterogeneity (I2= 67 and 47 %, respectively). For studies that eliminated preclinical bias, an inverse association was observed between the risk of breast cancer and TC (dose–response HR 0·94 (95 % CI 0·89, 0·99), seven studies, I2= 78 %; highest v. lowest HR 0·82 (95 % CI 0·66, 1·02), nine studies, I2= 81 %) and HDL-C (dose–response HR 0·81 (95 % CI 0·65, 1·02), five studies, I2= 30 %; highest v. lowest HR 0·82 (95 % CI 0·69, 0·98), five studies, I2= 0 %). There was no association observed between LDL-C and the risk of breast cancer (four studies). The present meta-analysis confirms the evidence of a modest but statistically significant inverse association between TC and more specifically HDL-C and the risk of breast cancer, supported by mechanistic plausibility from experimental studies. Further large prospective studies that adequately control for preclinical bias are needed to confirm the results on the role of cholesterol level and its fractions in the aetiology of breast cancer.
Incidence of neoplasia in patients with unilateral epiphora
Authors: Bewes T , Sacks R , Sacks P L , Chin D , Mrad N , Wilcsek G , Tumuluri K , Harvey R
Published: July 2015

Background:

Nasolacrimal duct obstruction is common and is usually a result of benign stricture formation. Although neoplasia near or around the lacrimal system may produce epiphora, the incidence of neoplasia from within the lacrimal system as a cause of nasolacrimal duct obstruction is not well documented.

Methods:

A retrospective study was performed on all patients undergoing dacryocystorhinostomy with a history of epiphora. The incidence of patients with operative findings of intra-lacrimal neoplasm was sought. Histopathologically confirmed cases were included.

Results:

The study comprised 537 patients, who underwent a total of 631 endoscopic dacryocystorhinostomy procedures between January 1998 and July 2013. Non-stenotic causes of nasolacrimal duct obstruction were encountered in 3.01 per cent of dacryocystorhinostomy procedures, and included neoplastic, inflammatory and infectious pathologies. Inverted papilloma was the most common cause, encountered in 0.79 per cent of dacryocystorhinostomy operations.

Conclusion:

These findings suggest that neoplasia is an uncommon but not a rare cause of nasolacrimal duct obstruction. Surgical teams performing high numbers of dacryocystorhinostomy procedures should be aware of such pathology and patients counselled appropriately.
Changes in genetic risk for emotional eating across the menstrual cycle: a longitudinal study
Authors: Klump K. L. , Hildebrandt B. A. , O'Connor S. M. , Keel P. K. , Neale M. , Sisk C. L. , Boker S. , Burt S. A.
Published: July 2015

Background

Previous studies have shown significant within-person changes in binge eating and emotional eating across the menstrual cycle, with substantial increases in both phenotypes during post-ovulation. Increases in both estradiol and progesterone levels appear to account for these changes in phenotypic risk, possibly via increases in genetic effects. However, to date, no study has examined changes in genetic risk for binge phenotypes (or any other phenotype) across the menstrual cycle. The goal of the present study was to examine within-person changes in genetic risk for emotional eating scores across the menstrual cycle.

Method

Participants were 230 female twin pairs (460 twins) from the Michigan State University Twin Registry who completed daily measures of emotional eating for 45 consecutive days. Menstrual cycle phase was coded based on dates of menstrual bleeding and daily ovarian hormone levels.

Results

Findings revealed important shifts in genetic and environmental influences, where estimates of genetic influences were two times higher in post- as compared with pre-ovulation. Surprisingly, pre-ovulation was marked by a predominance of environmental influences, including shared environmental effects which have not been previously detected for binge eating phenotypes in adulthood.

Conclusions

Our study was the first to examine within-person shifts in genetic and environmental influences on a behavioral phenotype across the menstrual cycle. Results highlight a potentially critical role for these shifts in risk for emotional eating across the menstrual cycle and underscore the need for additional, large-scale studies to identify the genetic and environmental factors contributing to menstrual cycle effects.
The “Nawrūz King”: the rebellion of Amir Nawrūz in Khurasan (688–694/1289–94) and its implications for the Ilkhan polity at the end of the thirteenth century
Authors: Hope Michael
Published: July 2015

In 688/1289 Nawrūz Aqa, a leading Mongol magnate, began a rebellion in Khurasan to resist the Ilkhan Arghun's attempts to centralize power and loosen the Mongol aristocracy's grip on provincial government. The rebellion of Nawrūz was significantly different from any Mongol uprising that had occurred in the Ilkhanate to that date: it was distinguished by the successful fusion of Chinggisid and Islamic traditions of political and spiritual authority to support Nawrūz's challenge against the Hülegüid monarchy. This new hybrid political philosophy allowed Nawrūz to mobilize both the sedentary and nomadic populations of Khurasan to overhaul the power structure of the Ilkhanate. The present study of the early career and rebellion of Amīr Nawrūz will reveal how his movement forced the Turco-Mongolian leadership to reconfigure its political, social and religious relationships, among themselves and with the sedentary Muslim population they ruled.
OPTION PRICING FOR PROCESSES DRIVEN BY MIXED FRACTIONAL BROWNIAN MOTION WITH SUPERIMPOSED JUMPS
Authors: Rao B.L.S. Prakasa
Published: July 2015

We propose a geometric mixed fractional Brownian motion model for the stock price process with possible jumps superimposed by an independent Poisson process. Option price of the European call option is computed for such a model. Some special cases are studied in detail.
Effects of target attributes on children's patterns of referential under- and over-specification
Authors: CHAREST MONIQUE , JOHNSTON JUDITH R.
Published: July 2015

We examined the effects of object attributes on children's descriptive patterns in a referential communication task. Thirty preschoolers described object pairs that were selected by the experimenter. The targets were defined by shared size or colour, and differed on the non-target dimension in half of the trials. The children also completed a non-verbal reasoning task with analogous stimuli. They selected objects after observing the experimenter make a choice and inferring the basis for selection. In the communication task, the children produced fewer size than colour descriptions, particularly when the size targets differed in colour. They also over-specified colour features more often than size. They did not show a similar challenge identifying size relationships in the non-verbal task. The results support the conclusion that target attributes have a systematic influence on children's referential performance. Potential mechanisms for these effects, and directions for future research are discussed.
On complex line arrangements and their boundary manifolds
Authors: FLORENS V. , GUERVILLE-BALLÉ B. , MARCO-BUZUNARIZ M.A.
Published: July 2015

Let ${\mathcal A}$ be a line arrangement in the complex projective plane $\mathds{C}\mathds{P}^2$. We define and describe the inclusion map of the boundary manifold, the boundary of a closed regular neighbourhood of ${\mathcal A}$, in the exterior of the arrangement. We obtain two explicit descriptions of the map induced on the fundamental groups. These computations provide a new minimal presentation of the fundamental group of the complement.
A heat trace anomaly on polygons
Authors: MAZZEO RAFE , ROWLETT JULIE
Published: July 2015

Let Ω0be a polygon in$\mathbb{R}$2, or more generally a compact surface with piecewise smooth boundary and corners. Suppose that Ωεis a family of surfaces with${\mathcal C}$∞boundary which converges to Ω0smoothly away from the corners, and in a precise way at the vertices to be described in the paper. Fedosov [6], Kac [8] and McKean–Singer [13] recognised that certain heat trace coefficients, in particular the coefficient oft0, are not continuous as ε ↘ 0. We describe this anomaly using renormalized heat invariants of an auxiliary smooth domainZwhich models the corner formation. The result applies to both Dirichlet and Neumann boundary conditions. We also include a discussion of what one might expect in higher dimensions.
Hormonal induction of Brycon cephalus (Characiformes, Characidae) to spermiation using D-ala6, pro9net-mGnRH + metoclopramide
Authors: Bashiyo-Silva Cristiane , Costa Raphael da Silva , Ribeiro Douglas de Castro , Senhorini José Augusto , Veríssimo-Silveira Rosicleire , Ninhaus-Silveira Alexandre
Published: July 2015

This study aimed to establish a hormonal induction protocol for spermiation of Brycon cephalus males, using Ala6, Pro9Net-mGnRH + metoclopramide (Ovopel®). Thus, 20 males were used divided into three inductor treatments [⅓ pellet/kg (T1), ⅔ pellet/kg (T2) and 1⅓ pellet/kg (T3)] and one control group (CO), which only received physiological solution applications (0.9% NaCl). All treatments were applied in a single dose. For evaluation of the availability of the treatment, the following seminal parameters were analyzed: seminal volume, subjective spermatic motility, duration of motility, pH, osmolality and spermatic concentration. T3 showed the highest seminal volume (4.66 ± 1.52 ml), and was significantly different in comparison with T1 (2.0 ± 0.9 ml), T2 (3.5 ± 1.3 ml) and CO (2.3 ± 1.2 ml). In relation to spermatic motility, T2 and T3 showed significantly higher levels [5, (81–100%)]. However, T3 showed significantly lower average sperm motility duration than T1, T2 and CO (30 ± 7 s; 28 ± 6 s; 32 ± 8 s, respectively). With regard to the seminal parameters of spermatic concentration, pH and osmolality, no significant variation was verified among treatments. In conclusion, mGnRH + metoclopramide used for hormonal induction of B. cephalus reproduction does not induce changes related to spermatic concentration, pH and osmolality parameters of the seminal fluid and the most adequate doses among tested treatments were ⅔ pellet/kg live fish.
Takotsubo cardiomyopathy: a case report and literature review
Authors: Rozema Tamika , Klein Lisa R.
Published: July 2015

Takotsubo cardiomyopathy, “broken heart syndrome”, is a well-known diagnosis in adults; however, this entity remains rare and is not well represented in the paediatric population. This report illustrates a case of takotsubo cardiomyopathy in a premature neonate with a brief discussion of the condition.
HOW DO MACROECONOMIC IMBALANCES INTERACT? EVIDENCE FROM A PANEL VAR ANALYSIS
Authors: Gnimassoun Blaise , Mignon Valérie
Published: July 2015

This paper investigates the interactions between three key macroeconomic imbalances, namely current-account discrepancies (external imbalances), output gaps (internal imbalances), and exchange-rate misalignments. We estimate a panel VAR model for a sample of 22 industrialized countries over the period 1980–2011. Our findings show that macroeconomic imbalances strongly interact through a causal relationship. If current-account disequilibria threaten the stability of the global economy, their origin can be found in internal imbalances and exchange-rate misalignments: positive output-gap shocks as well as currency overvaluation deepen current-account deficits. In addition, although variations in external imbalances mainly result from exchange-rate misalignments in the euro area, they are mostly explained by output gaps for non-eurozone members.
No association between fish consumption and risk of stroke in the Spanish cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Spain): a 13·8-year follow-up study
Authors: Amiano Pilar , Chamosa Saioa , Etxezarreta Nerea , Arriola Larraitz , Moreno-Iribas Conchi , Huerta José-María , Egües Nerea , Guevara Marcela , Navarro Carmen , Chirlaque María-Dolores , Sánchez María-José , Molina-Montes Esther , Requena Mar , Quirós Jose-Ramón , Obón-Santacana Mireia , Jakszyn Paula , González Carlos-Alberto , Dorronsoro Miren
Published: July 2015

Objective

To prospectively assess the associations between lean fish, fatty fish and total fish intakes and risk of stroke in the Spanish cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Spain).

Design

Fish intake was estimated from a validated dietary questionnaire. Cox proportional hazards regression models were used to assess the association between the intakes of lean fish, fatty fish and total fish and stroke risk. Models were run separately for men and women.

Setting

Five Spanish regions (Asturias, San Sebastian, Navarra, Granada and Murcia).

Subjects

Individuals (n 41 020; 15 490 men and 25 530 women) aged 20–69 years, recruited from 1992 to 1996 and followed-up until December 2008 (December 2006 in the case of Asturias). Only participants with definite incident stroke were considered as cases.

Results

During a mean follow-up of 13·8 years, 674 strokes were identified and subsequently validated by record linkage with hospital discharge databases, primary-care records and regional mortality registries, comprising 531 ischaemic, seventy-nine haemorrhagic, forty-two subarachnoid and twenty-two unspecific strokes. After multiple adjustments, no significant associations were observed between lean fish, fatty fish and total fish consumption and the risk of stroke in men or women. In men, results revealed a non-significant trend towards an inverse association between lean fish (hazard ratio=0·84; 95 % CI 0·55, 1·29, Ptrend=0·06) and total fish consumption (hazard ratio=0·77; 95 % CI 0·51, 1·16, Ptrend=0·06) and risk of total stroke.

Conclusions

In the EPIC-Spain cohort, no association was found between lean fish, fatty fish and total fish consumption and risk of stroke.
Switching rates in health insurance markets decrease with age: empirical evidence and policy implications from the Netherlands
Authors: Duijmelinck Daniëlle M.I.D. , van de Ven Wynand P.M.M.
Published: July 2015

All consumer groups with specific preferences must feel free to easily switch insurer in order to discipline insurers to be responsive to consumers’ heterogeneous preferences. This paper provides insight into the switching behaviour of low-risks (i.e. young or healthy consumers) and high-risks (i.e. elderly or unhealthy consumers) in the Netherlands in the period 2009–2012. We analysed: (1) administrative data with objective health status information (i.e. medically diagnosed diseases and pharmaceutical use) and information on health care expenses of nearly the entire Dutch population (n=15.3 million individuals) and (2) three-year sample data (n=1152 individuals). Our findings indicate that switching rates strongly decrease with age. For example, in 2009, consumers aged 25–44 switched 10 times more than consumers aged 75 or older. Another finding is that switching rates decrease as the predicted health care expenses increase. Although healthy consumers switch twice as much as unhealthy consumers, this difference becomes much smaller after adjusting for age. We conclude that our findings can be explained by higher perceived switching costs by elderly consumers than by young consumers. Consequently, insurers have low incentives to act as quality-conscious purchasers of care for the elderly consumers. Therefore, strategies should be developed to increase the choice of insurer of elderly consumers.
The effects of non-linearity in spectrum sensing receivers
Authors: Turunen Vesa , Kosunen Marko , Kallioinen Sami , Pärssinen Aarno , Ryynänen Jussi
Published: July 2015

This paper analyses the effects of receiver non-linearity on the performance of the most commonly utilized signal detectors in cognitive radio systems. The analysis covers both self-modulation products of a single orthogonal frequency-division multiplexing (OFDM) signal and intermodulation(IM)products of two OFDM signals, and also their contribution to the probability of false detections. As a result, this work presents the linearity requirements for the spectrum sensor receiver front-end as a function of the sensitivity of the signal detector. Furthermore, we show that the cyclostationary feature detectors are more robust than the energy detectors against IM products of multiple interferers. Theoretical results are verified in measurements with a cyclostationary feature detector using digital video broadcasting – terrestrial (DVB-T) signals as an example.
A University-Government Partnership for Oceanographic Research
Authors: Smith Deborah , Alberts Jon , DeSilva Annette , Measures Christopher
Published: July 2015

After 44 years of coordinating the U.S. academic research fleet and facilities, the University-National Oceanographic Laboratory System (UNOLS) gears for the future.
The neuropathology and cerebrovascular mechanisms of dementia
Authors: Raz Limor , Knoefel Janice , Bhaskar Kiran
Published: July 2015

The prevalence of dementia is increasing in our aging population at an alarming rate. Because of the heterogeneity of clinical presentation and complexity of disease neuropathology, dementia classifications remain controversial. Recently, the National Plan to address Alzheimer’s Disease prioritized Alzheimer’s disease-related dementias to include: Alzheimer’s disease, dementia with Lewy bodies, frontotemporal dementia, vascular dementia, and mixed dementias. While each of these dementing conditions has their unique pathologic signature, one common etiology shared among all these conditions is cerebrovascular dysfunction at some point during the disease process. The goal of this comprehensive review is to summarize the current findings in the field and address the important contributions of cerebrovascular, physiologic, and cellular alterations to cognitive impairment in these human dementias. Specifically, evidence will be presented in support of small-vessel disease as an underlying neuropathologic hallmark of various dementias, while controversial findings will also be highlighted. Finally, the molecular mechanisms shared among all dementia types including hypoxia, oxidative stress, mitochondrial bioenergetics, neuroinflammation, neurodegeneration, and blood–brain barrier permeability responsible for disease etiology and progression will be discussed.
Vascular Coupling in Resting-State FMRI: Evidence from Multiple Modalities
Authors: Zhu David C , Tarumi Takashi , Khan Muhammad Ayaz , Zhang Rong
Published: July 2015

Resting-state functional magnetic resonance imaging (rs-fMRI) provides a potential to understand intrinsic brain functional connectivity. However, vascular effects in rs-fMRI are still not fully understood. Through multiple modalities, we showed marked vascular signal fluctuations and high-level coupling among arterial pressure, cerebral blood flow (CBF) velocity and brain tissue oxygenation at < 0.08 Hz. These similar spectral power distributions were also observed in blood oxygen level-dependent (BOLD) signals obtained from six representative regions of interest (ROIs). After applying brain global, white-matter, cerebrospinal fluid (CSF) mean signal regressions and low-pass filtering (< 0.08 Hz), the spectral power of BOLD signal was reduced by 55.6% to 64.9% in all ROIs ( P = 0.011 to 0.001). The coherence of BOLD signal fluctuations between an ROI pair within a same brain network was reduced by 9.9% to 20.0% ( P = 0.004 to < 0.001), but a larger reduction of 22.5% to 37.3% ( P = 0.032 to < 0.001) for one not in a same network. Global signal regression overall had the largest impact in reducing spectral power (by 52.2% to 61.7%) and coherence, relative to the other three preprocessing steps. Collectively, these findings raise a critical question of whether a large portion of rs-fMRI signals can be attributed to the vascular effects produced from upstream changes in cerebral hemodynamics.
Non-Additive Effects of Delayed Connexin Hemichannel Blockade and Hypothermia after Cerebral Ischemia in Near-Term Fetal Sheep
Authors: Davidson Joanne O , Rout Alexandra L , Wassink Guido , Yuill Caroline A , Zhang Frank G , Green Colin R , Bennet Laura , Gunn Alistair J
Published: July 2015

Hypothermia is partially neuroprotective after neonatal hypoxic-ischemic encephalopathy. Blockade of connexin hemichannels can improve recovery of brain activity and cell survival after ischemia in near-term fetal sheep. In this study, we investigated whether combining delayed hypothermia with connexin hemichannel blockade with intracerebroventricular infusion of a mimetic peptide can further improve outcomes after cerebral ischemia. Fetal sheep (0.85 gestation) received 30 minutes of cerebral ischemia followed by a 3-hour recovery period before treatment was started. Fetuses were randomized to one of the following treatment groups: normothermia ( n = 8), hypothermia for 3 days ( n = 8), connexin hemichannel blockade (50 umol/L intracerebroventricular over 1 hour followed by 50 umol/L over 24 hours, n = 8) or hypothermia plus hemichannel blockade ( n = 7). After 7 days recovery, hypothermia was associated with reduced seizure burden, improved electroencephalographic (EEG) power, and a significant increase in neuronal and oligodendrocyte survival and reduced induction of Iba1-positive microglia. In contrast, although hemichannel blockade reduced seizure burden, there was no effect on EEG power or histology ( P < 0.05). There was no further improvement in outcomes with combined hypothermia plus hemichannel blockade. In conclusion, these data show that there is no additive neuroprotection with combined hypothermia and hemichannel blockade after cerebral ischemia in near-term fetal sheep.
Rapid epitaxy-free graphene synthesis on silicidated polycrystalline platinum
Authors: Babenko Vitaliy , Murdock Adrian T. , Koós Antal A. , Britton Jude , Crossley Alison , Holdway Philip , Moffat Jonathan , Huang Jian , Alexander-Webber Jack A. , Nicholas Robin J. , Grobert Nicole
Published: July 2015

Large-area synthesis of high-quality graphene by chemical vapour deposition on metallic substrates requires polishing or substrate grain enlargement followed by a lengthy growth period. Here we demonstrate a novel substrate processing method for facile synthesis of mm-sized, single-crystal graphene by coating polycrystalline platinum foils with a silicon-containing film. The film reacts with platinum on heating, resulting in the formation of a liquid platinum silicide layer that screens the platinum lattice and fills topographic defects. This reduces the dependence on the surface properties of the catalytic substrate, improving the crystallinity, uniformity and size of graphene domains. At elevated temperatures growth rates of more than an order of magnitude higher (120 μm min−1) than typically reported are achieved, allowing savings in costs for consumable materials, energy and time. This generic technique paves the way for using a whole new range of eutectic substrates for the large-area synthesis of 2D materials.
Intrinsically stretchable and transparent thin-film transistors based on printable silver nanowires, carbon nanotubes and an elastomeric dielectric
Authors: Liang Jiajie , Li Lu , Chen Dustin , Hajagos Tibor , Ren Zhi , Chou Shu-Yu , Hu Wei , Pei Qibing
Published: July 2015

Thin-film field-effect transistor is a fundamental component behind various mordern electronics. The development of stretchable electronics poses fundamental challenges in developing new electronic materials for stretchable thin-film transistors that are mechanically compliant and solution processable. Here we report the fabrication of transparent thin-film transistors that behave like an elastomer film. The entire fabrication is carried out by solution-based techniques, and the resulting devices exhibit a mobility of ∼30 cm2 V−1 s−1, on/off ratio of 103–104, switching current >100 μA, transconductance >50 μS and relative low operating voltages. The devices can be stretched by up to 50% strain and subjected to 500 cycles of repeated stretching to 20% strain without significant loss in electrical property. The thin-film transistors are also used to drive organic light-emitting diodes. The approach and results represent an important progress toward the development of stretchable active-matrix displays.
Molecular interactions on single-walled carbon nanotubes revealed by high-resolution transmission microscopy
Authors: Umeyama Tomokazu , Baek Jinseok , Sato Yuta , Suenaga Kazu , Abou-Chahine Fawzi , Tkachenko Nikolai V. , Lemmetyinen Helge , Imahori Hiroshi
Published: July 2015

The close solid-state structure–property relationships of organic π−aromatic molecules have attracted interest due to their implications for the design of organic functional materials. In particular, a dimeric structure, that is, a unit consisting of two molecules, is required for precisely evaluating intermolecular interactions. Here, we show that the sidewall of a single-walled carbon nanotube (SWNT) represents a unique molecular dimer platform that can be directly visualized using high-resolution transmission electron microscopy. Pyrene is chosen as the π−aromatic molecule; its dimer is covalently linked to the SWNT sidewalls by aryl addition. Reflecting the orientation and separation of the two molecules, the pyrene dimer on the SWNT exhibits characteristic optical and photophysical properties. The methodology discussed here—form and probe molecular dimers—is highly promising for the creation of unique models and provides indispensable and fundamental information regarding molecular interactions.
Giant colloidal silver crystals for low-loss linear and nonlinear plasmonics
Authors: Wang Chun-Yuan , Chen Hung-Ying , Sun Liuyang , Chen Wei-Liang , Chang Yu-Ming , Ahn Hyeyoung , Li Xiaoqin , Gwo Shangjr
Published: July 2015

The development of ultrasmooth, macroscopic-sized silver (Ag) crystals exhibiting reduced losses is critical to fully characterize the ultimate performance of Ag as a plasmonic material, and to enable cascaded and integrated plasmonic devices. Here we demonstrate the growth of single-crystal Ag plates with millimetre lateral sizes for linear and nonlinear plasmonic applications. Using these Ag crystals, surface plasmon polariton propagation lengths beyond 100 μm in the red wavelength region are measured. These lengths exceed the predicted values using the widely cited Johnson and Christy data. Furthermore, they allow the fabrication of highly reproducible plasmonic nanostructures by focused ion beam milling. We have designed and fabricated double-resonant nanogroove arrays using these crystals for spatially uniform and spectrally tunable second-harmonic generation. In conventional ‘hot-spot’-based nonlinear processes such as surface-enhanced Raman scattering and second-harmonic generation, strong enhancement can only occur in random, localized regions. In contrast, our approach enables uniform nonlinear signal generation over a large area.
Engineering deceleration and acceleration of soliton emitted from Airy pulse with quadratic phase modulation in optical fibers without high-order effects
Authors: Zhang Lifu , Liu Kun , Zhong Haizhe , Zhang Jinggui , Deng Jianqin , Li Ying , Fan Dianyuan
Published: July 2015

Soliton propagation direction can be engineered in optical fibers in the presence of high-order effects (HOEs). It is well known that Raman effects can decelerate the soliton. Here we investigate the manipulation of the deceleration or acceleration of soliton emitted from Airy pulse whose spectrum is imposed an initial quadratic phase modulation (QPM) in optical fibers in the absence of HOEs. We show that, under the action of the anomalous second-order dispersion (SOD) and Kerr nonlinearity, Airy pulse with QPM is able to emit soliton with acceleration or deceleration depending on whether the QPM is negative or positive and at a rate that is determined by the magnitude of QPM. The reason is that the acceleration behaviors of incident Airy pulse is altered depending on whether SOD and QPM have the same or opposite signs. Our study shows the possibility of controlling and manipulating the soliton propagation and interaction in optical fibers without HOEs, by purposely choosing appropriate QPM parameter of an Airy pulse.
Seismic footprints of shallow dyke propagation at Etna, Italy
Authors: Falsaperla Susanna , Neri Marco
Published: July 2015

One of the key issues in forecasting volcanic eruptions is to detect signals that can track the propagation of dykes towards the surface. Continuous monitoring of active volcanoes helps significantly in achieving this goal. The seismic data presented here are unique, as they document surface faulting processes close (tens to a few hundred meters) to their source, namely the dyke tip. They originated nearby - and under - a seismic station that was subsequently destroyed by lava flows during eruptive activity at Etna volcano, Italy, in 2013. On February 20, a ~600 m-long and ~120 m wide NW-SE fracture field opened at an altitude between 2750 and 2900 m. The consequent rock dislocation caused the station to tilt and offset the seismic signal temporarily. Data acquisition continued until the arrival of the lava flow that led to the breakdown of the transmission system. Shallow ground fracturing and repeated low-frequency oscillations occurred during two stages in which the seismic signal underwent a maximum offset ~2.57 × 104 nm/s. Bridging instrumental recordings, fieldwork and conceptual modelling, these data are interpreted as the seismic footprints of a magmatic dyke intrusion that moved at speed ~0.02 m/s (first stage) and 0.46 m/s (second stage).
Stimulated scattering effects in gold-nanorod-water samples pumped by 532 nm laser pulses
Authors: Shi Jiulin , Wu Haopeng , Liu Juan , Li Shujing , He Xingdao
Published: July 2015

Stimulated scattering in gold-nanorod-water samples has been investigated experimentally. The scattering centers are impurity particles rather than the atoms or molecules of conventional homogeneous scattering media. The pump source for exciting stimulated scattering is a pulsed and narrow linewidth second-harmonic Nd: YAG laser, with 532 nm wavelength, ~8 ns pulse duration and 10 Hz repetition rate. Experimental results indicate that SMBS, SBS and STRS can be generated in gold-nanorod-water samples under appropriate pump and absorption conditions. The incident pump energy has to be larger than a certain threshold value before stimulated scattering can be detected. The absorption coefficient of samples at 532 nm wavelength depends on the one of characteristic absorption bands of gold nanorods located around 530 nm. A critical absorption coefficient "Equation missing" can be determined for the transition from SBS to STRS. Also, the spectral-line-broadening effects of STRS have been observed, the line-shape presents a pseudo-Voigt profile due to the random thermal motion of molecules and strong particle collision.
Polymerase/DNA interactions and enzymatic activity: multi-parameter analysis with electro-switchable biosurfaces
Authors: Langer Andreas , Schräml Michael , Strasser Ralf , Daub Herwin , Myers Thomas , Heindl Dieter , Rant Ulrich
Published: July 2015

The engineering of high-performance enzymes for future sequencing and PCR technologies as well as the development of many anticancer drugs requires a detailed analysis of DNA/RNA synthesis processes. However, due to the complex molecular interplay involved, real-time methodologies have not been available to obtain comprehensive information on both binding parameters and enzymatic activities. Here we introduce a chip-based method to investigate polymerases and their interactions with nucleic acids, which employs an electrical actuation of DNA templates on microelectrodes. Two measurement modes track both the dynamics of the induced switching process and the DNA extension simultaneously to quantitate binding kinetics, dissociation constants and thermodynamic energies. The high sensitivity of the method reveals previously unidentified tight binding states for Taq and Pol I (KF) DNA polymerases. Furthermore, the incorporation of label-free nucleotides can be followed in real-time and changes in the DNA polymerase conformation (finger closing) during enzymatic activity are observable.
Flexural bending of southern Tibet in a retro foreland setting
Authors: Wang Erchie , Kamp Peter J. J. , Xu Ganqing , Hodges Kip V. , Meng Kai , Chen Lin , Wang Gang , Luo Hui
Published: July 2015

The highest elevation of the Tibetan Plateau, lying 5,700 m above sea level, occurs within the part of the Lhasa block immediately north of the India-Tibet suture zone (Yarlung Zangbo suture zone, YZSZ), being 700 m higher than the maximum elevation of more northern parts of the plateau. Various mechanisms have been proposed to explain this differentially higher topography and the rock uplift that led to it, invoking crustal compression or extension. Here we present the results of structural investigations along the length of the high elevation belt and suture zone, which rather indicate flexural bending of the southern margin of the Lhasa block (Gangdese magmatic belt) and occurrence of an adjacent foreland basin (Kailas Basin), both elements resulting from supra-crustal loading of the Lhasa block by the Zangbo Complex (Indian plate rocks) via the Great Counter Thrust. Hence we interpret the differential elevation of the southern margin of the plateau as due originally to uplift of a forebulge in a retro foreland setting modified by subsequent processes. Identification of this flexural deformation has implications for early evolution of the India-Tibet continental collision zone, implying an initial (Late Oligocene) symmetrical architecture that subsequently transitioned into the present asymmetrical wedge architecture.
Large scale systematic proteomic quantification from non-metastatic to metastatic colorectal cancer
Authors: Yin Xuefei , Zhang Yang , Guo Shaowen , Jin Hong , Wang Wenhai , Yang Pengyuan
Published: July 2015

A systematic proteomic quantification of formalin-fixed, paraffin-embedded (FFPE) colorectal cancer tissues from stage I to stage IIIC was performed in large scale. 1017 proteins were identified with 338 proteins in quantitative changes by label free method, while 341 proteins were quantified with significant expression changes among 6294 proteins by iTRAQ method. We found that proteins related to migration expression increased and those for binding and adherent decreased during the colorectal cancer development according to the gene ontology (GO) annotation and ingenuity pathway analysis (IPA). The integrin alpha 5 (ITA5) in integrin family was focused, which was consistent with the metastasis related pathway. The expression level of ITA5 decreased in metastasis tissues and the result has been further verified by Western blotting. Another two cell migration related proteins vitronectin (VTN) and actin-related protein (ARP3) were also proved to be up-regulated by both mass spectrometry (MS) based quantification results and Western blotting. Up to now, our result shows one of the largest dataset in colorectal cancer proteomics research. Our strategy reveals a disease driven omics-pattern for the metastasis colorectal cancer.
Single step transformation of sulphur to Li2S2/Li2S in Li-S batteries
Authors: Helen M. , Reddy M. Anji , Diemant Thomas , Golla-Schindler Ute , Behm R. Jürgen , Kaiser Ute , Fichtner Maximilian
Published: July 2015

Lithium-sulphur batteries have generated tremendous research interest due to their high theoretical energy density and potential cost-effectiveness. The commercial realization of Li-S batteries is still hampered by reduced cycle life associated with the formation of electrolyte soluble higher-order polysulphide (Li2Sx, x = 4–8) intermediates, leading to capacity fading, self-discharge and a multistep voltage profile. Herein, we have realized a practical approach towards a direct transformation of sulphur to Li2S2/Li2S in lithium-sulphur batteries by alteration of the reaction pathway. A coconut shell derived ultramicroporous carbon-sulphur composite cathode has been used as reaction directing template for the sulphur. The lithiation/delithiation and capacity fading mechanism of microporous carbon confined sulphur composite was revealed by analyzing the subsurface using X-ray photoelectron spectroscopy. No higher-order polysulphides were detected in the electrolyte, on the surface and in the subsurface of the cathode composite. The altered reaction pathway is reflected by a single-step profile in the discharge/charge of a lithium-sulphur cell.
Transforming berberine into its intestine-absorbable form by the gut microbiota
Authors: Feng Ru , Shou Jia-Wen , Zhao Zhen-Xiong , He Chi-Yu , Ma Chao , Huang Min , Fu Jie , Tan Xiang-Shan , Li Xiao-Yang , Wen Bao-Ying , Chen Xi , Yang Xin-Yi , Ren Gang , Lin Yuan , Chen Yangchao , You Xue-Fu , Wang Yan , Jiang Jian-Dong
Published: July 2015

The gut microbiota is important in the pathogenesis of energy-metabolism related diseases. We focused on the interaction between intestinal bacteria and orally administered chemical drugs. Oral administration of berberine (BBR) effectively treats patients with metabolic disorders. However, because BBR exhibits poor solubility, its absorption mechanism remains unknown. Here, we show that the gut microbiota converts BBR into its absorbable form of dihydroberberine (dhBBR), which has an intestinal absorption rate 5-fold that of BBR in animals. The reduction of BBR to dhBBR was performed by nitroreductases of the gut microbiota. DhBBR was unstable in solution and reverted to BBR in intestine tissues via oxidization. Heat inactivation of intestinal homogenate did not inhibit dhBBR oxidization, suggesting the process a non-enzymatic reaction. The diminution of intestinal bacteria via orally treating KK-Ay mice with antibiotics decreased the BBR-to-dhBBR conversion and blood BBR; accordingly, the lipid- and glucose-lowering efficacy of BBR was reduced. Conclusively, the gut microbiota reduces BBR into its absorbable form of dhBBR, which then oxidizes back to BBR after absorption in intestine tissues and enters the blood. Thus, interaction(s) between the gut microbiota and orally administrated drugs may modify the structure and function of chemicals and be important in drug investigation.
Ultrasensitive measurement of huntingtin protein in cerebrospinal fluid demonstrates increase with Huntington disease stage and decrease following brain huntingtin suppression
Authors: Southwell Amber L. , Smith Stephen E.P. , Davis Tessa R. , Caron Nicholas S. , Villanueva Erika B. , Xie Yuanyun , Collins Jennifer A. , Li Ye Min , Sturrock Aaron , Leavitt Blair R. , Schrum Adam G. , Hayden Michael R.
Published: July 2015

Quantitation of huntingtin protein in the brain is needed, both as a marker of Huntington disease (HD) progression and for use in clinical gene silencing trials. Measurement of huntingtin in cerebrospinal fluid could be a biomarker of brain huntingtin, but traditional protein quantitation methods have failed to detect huntingtin in cerebrospinal fluid. Using micro-bead based immunoprecipitation and flow cytometry (IP-FCM), we have developed a highly sensitive mutant huntingtin detection assay. The sensitivity of huntingtin IP-FCM enables accurate detection of mutant huntingtin protein in the cerebrospinal fluid of HD patients and model mice, demonstrating that mutant huntingtin levels in cerebrospinal fluid reflect brain levels, increasing with disease stage and decreasing following brain huntingtin suppression. This technique has potential applications as a research tool and as a clinical biomarker.
Characterisation of Radioactively Contaminated Land at Dounreay, An Area with a High Natural Background
Authors: Heathcote J. A.
Published: July 2015

The Dounreay experimental reactor site is being decommissioned, with the expectation that some time before 2333, the land will be suitable for ‘any reasonably foreseeable use’. To achieve this, unacceptably contaminated materials must be identified and characterised for disposal as waste, and there must be a demonstration that residual materials meet relevant standards. This paper reviews experience gained from using the full range of commercial analytical techniques, to identify how contamination can be distinguished from background, using γ-spectrometry and gross α+β measurement.
Testing of a Computer Programme for Calculating the Sr-85 Yield as Well as Fallout Sr-89 and Sr-90 in a Single LSC Measurement with Detection Limits Conforming to Iso 11929
Authors: Tait D. , Vagt T. , Kanisch G. , Roos N.
Published: July 2015

Environmental surveillance of Sr-89 and Sr-90 following an accident or incident with fission material is particularly important. Most analytical strategies require at least two measurement procedures – one to determine Sr-89 and the other to determine Sr-90 indirectly by measuring the daughter Y-90. However, the Sr-89 and Sr-90 can be determined simultaneously and independently of the state of the Sr-90/Y-90 equilibrium by liquid scintillation counting. Modern LSCs allow the recording of scintillation spectra which facilitates the setting of energy regions for optimal counting of a particular radionuclide. The yield was determined by gamma spectrometry of the tracer Sr-85 added in known activity to the sample prior to analysis. This tracer is not present in nuclear fallout. In the event of a nuclear accident, however, the pressure on gamma-spectrometric capacity may limit the capability to carry out the Sr yield determination by this method.
Charting a Path to the Future
Authors: Martin J.
Published: July 2015

The UK has had civil nuclear power for over half a century and a significant legacy of higher activity nuclear waste and spent fuel awaits disposal. UK Government policy is to construct a geological disposal facility (GDF) to dispose of these materials, safely containing them over hundreds of thousands of years, while radioactive decay reduces their potential harm. Scotland has developed its own policy. To ensure that the GDF is fit for purpose, we need to understand the long term effects of irradiation on materials as well as the interactions between the various components of a facility and the wastes. Radiochemical research will play an important role in helping us understand these processes and will enable us to implement the best strategies for long term disposal. Studies on radionuclide release from spent fuel and vitrified wastes, the effects of complexants on radionuclide behaviour, the impact of microbes on the mobility of radionuclides and the behaviour of colloids (see Box 1) and non-aqueous phase liquids (see Box 2) – all of these pose questions that need to be answered as we develop the safety case for a geological disposal facility. Bringing all this research effort together to build a comprehensive safety case for the final repository, one that reflects best practice from around the world, is one of the tasks assigned to a new organisation, Radioactive Waste Management. RWM was created in April 2014 as a wholly-owned subsidiary of the Nuclear Decommissioning Authority (NDA). It builds on the work of the NDA's former Radioactive Waste Management Directorate.