bluuebunny/crossref_metadata_2025 huggingface dataset:
Correction: Corrigendum: Modeling dynamic interactions between pre-exposure prophylaxis interventions & treatment programs: predicting HIV transmission & resistance
Authors: Supervie Virginie , Barrett Meagan , Kahn James S. , Musuka Godfrey , Moeti Themba Lebogang , Busang Lesego , Blower Sally
Published: September 2015

Clinical trials have recently demonstrated the effectiveness of Pre-Exposure Prophylaxis (PrEP) in preventing HIV infection. Consequently, PrEP may soon be used for epidemic control. We model the dynamic interactions that will occur between treatment programs and potential PrEP interventions in resource-constrained countries. We determine the consequences for HIV transmission and drug resistance. We use response hypersurface modeling to predict the effect of PrEP on decreasing transmission as a function of effectiveness, adherence and coverage. We predict PrEP will increase need for second-line therapies (SLT) for treatment-naïve individuals, but could significantly decrease need for SLT for treatment-experienced individuals. If the rollout of PrEP is carefully planned it could increase the sustainability of treatment programs. If not, need for SLT could increase and the sustainability of treatment programs could be compromised. Our results show the optimal strategy for rolling out PrEP in resource-constrained countries is to begin around the “worst” treatment programs.
Erratum: Functional BCL-2 regulatory genetic variants contribute to susceptibility of esophageal squamous cell carcinoma
Authors: Pan Wenting , Yang Jinyun , Wei Jinyu , Chen Hongwei , Ge Yunxia , Zhang Jingfeng , Wang Zhiqiong , Zhou Changchun , Yuan Qipeng , Zhou Liqing , Yang Ming
Published: September 2015

B-cell lymphoma-2 (BCL-2) prevents apoptosis and its overexpression could promote cancer cell survival. Multiple functional BCL-2 genetic polymorphisms, such as rs2279115, rs1801018 and rs1564483, have been identified previously and might be involved in cancer development through deregulating BCL-2 expression. Therefore, we examined associations between these three polymorphisms and esophageal squamous cell carcinoma (ESCC) susceptibility as well as its biological function in vivo. Genotypes were determined in two independent case-control sets consisted of 1588 ESCC patients and 1600 controls from two regions of China. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by logistic regression. The impact of the rs2279115 polymorphism on BCL-2 expression was detected using esophagus tissues. Our results demonstrated that the BCL-2 rs2279115 AA genotype was significantly associated with decreased ESCC risk compared with the CC genotype (OR = 0.72, 95% CI = 0.57–0.90, P = 0.005), especially in nonsmokers (OR = 0.42, 95% CI = 0.29–0.59, P = 0.001) or nondrinkers (OR = 0.44, 95% CI = 0.32–0.62, P = 0.002). Genotype-phenotype correlation studies demonstrated that subjects with the rs2279115 CA and AA genotypes had a statistically significant decrease of BCL-2 mRNA expression compared to the CC genotype in both normal and cancerous esophagus tissues. Our results indicate that the BCL-2 rs2279115 polymorphism contributes to ESCC susceptibility in Chinese populations.
Shape memory polymers with high and low temperature resistant properties
Authors: Xiao Xinli , Kong Deyan , Qiu Xueying , Zhang Wenbo , Liu Yanju , Zhang Shen , Zhang Fenghua , Hu Yang , Leng Jinsong
Published: September 2015

High temperature shape memory polymers that can withstand the harsh temperatures for durable applications are synthesized and the aromatic polyimide chains with flexible linkages within the backbone act as reversible phase. High molecular weight (Mn) is demanded to form physical crosslinks as fixed phase of thermoplastic shape memory polyimide and the relationship between Mn and glass transition temperature (Tg) is explored. Thermoset shape memory polyimide shows higher Tg and storage modulus, better shape fixity than thermoplastic counterpart due to the low-density covalent crosslinking and the influence of crosslinking on physical properties are studied. The mechanism of high temperature shape memory effects based on chain flexibility, molecular weight and crosslink density is proposed. Exposure to thermal cycling from +150 °C to −150 °C for 200 h produces negligible effect on the properties of the shape memory polyimide and the possible mechanism of high and low temperature resistant property is discussed.
A Rewritable, Random-Access DNA-Based Storage System
Authors: Tabatabaei Yazdi S. M. Hossein , Yuan Yongbo , Ma Jian , Zhao Huimin , Milenkovic Olgica
Published: September 2015

We describe the first DNA-based storage architecture that enables random access to data blocks and rewriting of information stored at arbitrary locations within the blocks. The newly developed architecture overcomes drawbacks of existing read-only methods that require decoding the whole file in order to read one data fragment. Our system is based on new constrained coding techniques and accompanying DNA editing methods that ensure data reliability, specificity and sensitivity of access and at the same time provide exceptionally high data storage capacity. As a proof of concept, we encoded parts of the Wikipedia pages of six universities in the USA and selected and edited parts of the text written in DNA corresponding to three of these schools. The results suggest that DNA is a versatile media suitable for both ultrahigh density archival and rewritable storage applications.
Fabrication of large size graphene and Ti- MWCNTs/ large size graphene composites: their photocatalytic properties and potential application
Authors: Ullah Kefayat , Oh Won-Chun
Published: September 2015

Large size graphene (LSG) and multiwall carbon nanotubes (MWCNTs) on LSG were synthesized on a copper surface via chemical vapor deposition (CVD) at low temperature and normal pressure. The LSG were formed through an easy chemical cyclic reaction in which liquid benzene was heated to a temperature below its boiling point to create benzene vapors as graphene precursor material. The reaction mechanism was observed and the time-dependent analysis of the reaction revealed that mounds of the carbon nanotubes had grown as a result of the island that was found on the LSG sheet. The implications of the mechanism that we have introduced were investigated by coating a titanium sheet on the MWCNTs/LSG and LSG on the semiconductor electronic device. The photonic response was observed to be markedly high, which can be attributed to the positive synergetic effect between the Ti and LSG sheet of our prepared composites.
SeqMule: automated pipeline for analysis of human exome/genome sequencing data
Authors: Guo Yunfei , Ding Xiaolei , Shen Yufeng , Lyon Gholson J. , Wang Kai
Published: September 2015

Next-generation sequencing (NGS) technology has greatly helped us identify disease-contributory variants for Mendelian diseases. However, users are often faced with issues such as software compatibility, complicated configuration and no access to high-performance computing facility. Discrepancies exist among aligners and variant callers. We developed a computational pipeline, SeqMule, to perform automated variant calling from NGS data on human genomes and exomes. SeqMule integrates computational-cluster-free parallelization capability built on top of the variant callers and facilitates normalization/intersection of variant calls to generate consensus set with high confidence. SeqMule integrates 5 alignment tools, 5 variant calling algorithms and accepts various combinations all by one-line command, therefore allowing highly flexible yet fully automated variant calling. In a modern machine (2 Intel Xeon X5650 CPUs, 48 GB memory), when fast turn-around is needed, SeqMule generates annotated VCF files in a day from a 30X whole-genome sequencing data set; when more accurate calling is needed, SeqMule generates consensus call set that improves over single callers, as measured by both Mendelian error rate and consistency. SeqMule supports Sun Grid Engine for parallel processing, offers turn-key solution for deployment on Amazon Web Services, allows quality check, Mendelian error check, consistency evaluation, HTML-based reports. SeqMule is available at http://seqmule.openbioinformatics.org.
High-resolution adaptive imaging with a single photodiode
Authors: Soldevila F. , Salvador-Balaguer E. , Clemente P. , Tajahuerce E. , Lancis J.
Published: September 2015

During the past few years, the emergence of spatial light modulators operating at the tens of kHz has enabled new imaging modalities based on single-pixel photodetectors. The nature of single-pixel imaging enforces a reciprocal relationship between frame rate and image size. Compressive imaging methods allow images to be reconstructed from a number of projections that is only a fraction of the number of pixels. In microscopy, single-pixel imaging is capable of producing images with a moderate size of 128 × 128 pixels at frame rates under one Hz. Recently, there has been considerable interest in the development of advanced techniques for high-resolution real-time operation in applications such as biological microscopy. Here, we introduce an adaptive compressive technique based on wavelet trees within this framework. In our adaptive approach, the resolution of the projecting patterns remains deliberately small, which is crucial to avoid the demanding memory requirements of compressive sensing algorithms. At pattern projection rates of 22.7 kHz, our technique would enable to obtain 128 × 128 pixel images at frame rates around 3 Hz. In our experiments, we have demonstrated a cost-effective solution employing a commercial projection display.
Chemical labeling of intracellular proteins via affinity conjugation and strain-promoted cycloadditions in live cells
Authors: Chen Xi , Li Fu , Wu Yao-Wen
Published: September 2015

Tagging-then-labeling: a versatile chemical approach for labeling intracellular proteins in live cells.
A multifunctional transparent superhydrophobic gel nanocoating with self-healing properties
Authors: Si Yifan , Zhu Hai , Chen Liwei , Jiang Ting , Guo Zhiguang
Published: September 2015

A multifunctional green superhydrophobic gel nanocoating with good transparency and stability was obtained through a facile copolymerization reaction. Importantly, this well-designed nanocoating has self-healing superhydrophobicity to face complicated daily life and industry work conditions. It is applicable to various substrates via a simple spray process.
Real-time monitoring of rolling circle amplification using aggregation-induced emission: applications in biological detection
Authors: Jiang Hong-Xin , Zhao Meng-Yao , Niu Chen-Di , Kong De-Ming
Published: September 2015

Real-time monitoring of rolling circle amplification (RCA) was achieved by the super-aggregation of a tetraphenylethene dye QAPTE along single-stranded DNA products and consequent enhanced aggregation-induced emission, it can work for all RCA reactions.
Nanofabricated structures and microfluidic devices for bacteria: from techniques to biology
Authors: Wu Fabai , Dekker Cees
Published: September 2015

We review the use of nanofabricated structures and microfluidic technologies that spatially separate bacteria for quantitative analyses and that provide topological constraints on their growth and chemical communications.
Na+ diffusion kinetics in nanoporous metal-hexacyanoferrates
Authors: Takachi Masamitsu , Fukuzumi Yuya , Moritomo Yutaka
Published: September 2015

Metal-hexacyanoferrates (metal-HCFs) are promising candidates for cathode materials of sodium-ion secondary batteries (SIBs).
Tumor cell responses to carbon dots derived from chondroitin sulfate
Authors: Wang Shu-Jun , Wang Bei-Bei , Bai Feng-Wu , Ma Xiao-Jun
Published: September 2015

Photoluminescent carbon dots (CDs) derived from chondroitin sulfate (CS) showing multifunctional behavior: cell imaging and cell proliferative responses.
Catanionic vesicles and DNA complexes: a strategy towards novel gene delivery systems
Authors: Pucci C. , Scipioni A. , Diociaiuti M. , La Mesa C. , Pérez L. , Pons R.
Published: September 2015

Catanionic vesicles and DNA form complexes, the structure and composition of which depend on the DNA content. The DNA undergoes a reversible compaction process and its release can be triggered by adding an anionic surfactant to the complexes.
Enhanced photovoltaic performance and morphological control of the PbS counter electrode grown on functionalized self-assembled nanocrystals for quantum-dot sensitized solar cells via cost-effective chemical bath deposition
Authors: Thulasi-Varma Chebrolu Venkata , Rao S. Srinivasa , Ikkurthi Kanaka Durga , Kim Soo-Kyoung , Kang Tae-Su , Kim Hee-Je
Published: September 2015

This study describes the synthesis of monodispersed PbS nanocrystals by a facile chemical bath deposition and cost-effective approach.
Soybean extracts increase cell surface ZIP4 abundance and cellular zinc levels: a potential novel strategy to enhance zinc absorption by ZIP4 targeting
Authors: Hashimoto Ayako , Ohkura Katsuma , Takahashi Masakazu , Kizu Kumiko , Narita Hiroshi , Enomoto Shuichi , Miyamae Yusaku , Masuda Seiji , Nagao Masaya , Irie Kazuhiro , Ohigashi Hajime , Andrews Glen K. , Kambe Taiho
Published: September 2015

Dietary zinc deficiency puts human health at risk, so we explored strategies for enhancing zinc absorption. In the small intestine, the zinc transporter ZIP4 functions as an essential component of zinc absorption. Overexpression of ZIP4 protein increases zinc uptake and thereby cellular zinc levels, suggesting that food components with the ability to increase ZIP4 could potentially enhance zinc absorption via the intestine. In the present study, we used mouse Hepa cells, which regulate mouse Zip4 (mZip4) in a manner indistinguishable from that in intestinal enterocytes, to screen for suitable food components that can increase the abundance of ZIP4. Using this ZIP4-targeting strategy, two such soybean extracts were identified that were specifically able to decrease mZip4 endocytosis in response to zinc. These soybean extracts also effectively increased the abundance of apically localized mZip4 in transfected polarized Caco2 and Madin–Darby canine kidney cells and, moreover, two apically localized mZip4 acrodermatitis enteropathica mutants. Soybean components were purified from one extract and soyasaponin Bb was identified as an active component that increased both mZip4 protein abundance and zinc levels in Hepa cells. Finally, we confirmed that soyasaponin Bb is capable of enhancing cell surface endogenous human ZIP4 in human cells. Our results suggest that ZIP4 targeting may represent a new strategy to improve zinc absorption in humans.
Tryptophan metabolism, disposition and utilization in pregnancy
Authors: Badawy Abdulla A.-B.
Published: September 2015

Tryptophan (Trp) requirements in pregnancy are several-fold: (1) the need for increased protein synthesis by mother and for fetal growth and development; (2) serotonin (5-HT) for signalling pathways; (3) kynurenic acid (KA) for neuronal protection; (4) quinolinic acid (QA) for NAD+ synthesis (5) other kynurenines (Ks) for suppressing fetal rejection. These goals could not be achieved if maternal plasma [Trp] is depleted. Although plasma total (free + albumin-bound) Trp is decreased in pregnancy, free Trp is elevated. The above requirements are best expressed in terms of a Trp utilization concept. Briefly, Trp is utilized as follows: (1) In early and mid-pregnancy, emphasis is on increased maternal Trp availability to meet the demand for protein synthesis and fetal development, most probably mediated by maternal liver Trp 2,3-dioxygenase (TDO) inhibition by progesterone and oestrogens. (2) In mid- and late pregnancy, Trp availability is maintained and enhanced by the release of albumin-bound Trp by albumin depletion and non-esterified fatty acid (NEFA) elevation, leading to increased flux of Trp down the K pathway to elevate immunosuppressive Ks. An excessive release of free Trp could undermine pregnancy by abolishing T-cell suppression by Ks. Detailed assessment of parameters of Trp metabolism and disposition and related measures (free and total Trp, albumin, NEFA, K and its metabolites and pro- and anti-inflammatory cytokines in maternal blood and, where appropriate, placental and fetal material) in normal and abnormal pregnancies may establish missing gaps in our knowledge of the Trp status in pregnancy and help identify appropriate intervention strategies.
Semantic Feature Analysis: Further Examination of Outcomes
Authors: DeLong Catharine , Nessler Christina , Wright Sandra , Wambaugh Julie
Published: September 2015

Purpose

The purpose of this investigation was to systematically examine outcomes associated with Semantic feature analysis, which is an established treatment for word-retrieval deficits in aphasia. Attributes of the experimental design and stimuli were manipulated to evaluate generalized naming of semantically related and unrelated items. In addition, the study was designed to examine changes in production of semantic information.

Method

Semantic feature analysis was applied in the context of multiple-baseline designs with 5 persons with chronic aphasia. Experimental items were controlled for semantic category membership, number of naming attempts, and provision of item names. Acquisition, generalization, and maintenance effects were measured in probes of naming performance. Production of semantic information was also measured in response to experimental items and in discourse tasks.

Results

Treatment was associated with systematic increases in naming of trained items for 4 of the 5 participants. Positive generalization to untrained exemplars of trained categories was found for repeatedly exposed items but not for limited-exposure items. Slight increases in production of semantic content were observed.

Conclusion

Repeated attempts to name untreated items appeared to play a role in generalization. Provision of the names of untrained items may have enhanced generalized responding for 2 participants.

Supplemental Material

https://doi.org/10.23641/asha.6170249
Evolutionary design of complex digital circuits based on hierarchical module composition and predominant component prevention
Authors: Jung Sun Hoon , Kim Ger‐Yong , Cho Kwang‐Hyun
Published: September 2015

The critical challenge in designing complex digital circuits automatically using an evolutionary algorithm is to overcome the scalability issue caused by combinatorial explosion. Because of this problem, the existing evolutionary design methods can deal with digital circuits composed of only a small number of bits. To resolve this problem, a novel evolutionary design method is proposed on the basis of hierarchical module structures and predominant component prevention. From extensive experiments, it is found that this method can automatically design digital circuits composed of a large number of bits within a polynomial time.
Wideband radar cross‐section reduction of microstrip patch antenna with split‐ring resonators
Authors: Hao Yuwen , Liu Ying , Li Kun , Gong Shuxi
Published: September 2015

A novel technique for wideband radar cross‐section (RCS) reduction of a microstrip antenna, with the radiating performance preserved at the same time, is proposed and investigated. The design is based on replacing the solid metal ground with the hybrid ground, which consists of suitable compact split‐ring resonators. The antenna irradiated by both transverse‐electric and transverse‐magnetic polarised waves in the normal direction is analysed and investigated. Results show that RCS is dramatically reduced over a wide frequency range from 2 to 20 GHz. By comparison, remarkable RCS reduction of about 11 dB at 20 GHz can be obtained by the proposed strategy. Based on the acceptable effect on radiation features and prominent RCS reduction, the superior performance and reliability of the proposed design are demonstrated.
High‐selectivity tri‐band bandpass filter with ultra‐wide stopband
Authors: Zhu Chuanming , Xu Jin , Kang Wei , Wu Wen
Published: September 2015

A tri‐band bandpass filter (BPF) with an ultra‐wide stopband is proposed. Based on tri‐mode unequal‐length shunted‐line stepped impedance resonators (SIRs), some extra resonator sections are added in unequal‐length shunted‐line SIRs to increase the degrees of freedom in extracting the coupling coefficients of the tri‐band BPF. Unequal‐length shunted‐line SIRs can provide an efficient way to obtain a tri‐band BPF with a small frequency ratio between the first two centre frequencies. Moreover, two transmission zeros can be achieved near every passband by employing cross‐coupling, resulting in high passband selectivity, excellent band‐to‐band isolation and an ultra‐wide stopband. As an example, a tri‐band BPF is demonstrated. Simulated results of the filter agree well with the measured ones.
Continuously tunable substrate integrated waveguide bandpass filter in liquid crystal technology with magnetic biasing
Authors: Prasetiadi A.E. , Karabey O.H. , Weickhmann C. , Franke T. , Hu W. , Jost M. , Nickel M. , Jakoby R.
Published: September 2015

A liquid crystal filled continuously tunable substrate integrated waveguide filter is proposed which has a high‐quality (Q) factor. To measure the Q‐factor, a single resonator measurement is performed by using magnetic biasing in a lab demonstrator for a proof of concept. The unloaded Q‐factor is 102–105.6. The resonator is employed to create a three‐pole Chebyshev filter with a centre frequency of 22 GHz and a bandwidth of 600 MHz. Measurement results show a 6 dB insertion loss with a return loss of about 10 dB. The filter is continuously tunable within a tuning range of 610 MHz.
The appearance and propagation of filaments in the private flux region in Mega Amp Spherical Tokamak
Authors: Harrison J. R. , Fishpool G. M. , Thornton A. J. , Walkden N. R. ,   MAST team
Published: September 2015

The transport of particles via intermittent filamentary structures in the private flux region (PFR) of plasmas in the MAST tokamak has been investigated using a fast framing camera recording visible light emission from the volume of the lower divertor, as well as Langmuir probes and IR thermography monitoring particle and power fluxes to plasma-facing surfaces in the divertor. The visible camera data suggest that, in the divertor volume, fluctuations in light emission above the X-point are strongest in the scrape-off layer (SOL). Conversely, in the region below the X-point, it is found that these fluctuations are strongest in the PFR of the inner divertor leg. Detailed analysis of the appearance of these filaments in the camera data suggests that they are approximately circular, around 1–2 cm in diameter, but appear more elongated near the divertor target. The most probable toroidal quasi-mode number is between 2 and 3. These filaments eject plasma deeper into the private flux region, sometimes by the production of secondary filaments, moving at a speed of 0.5–1.0 km/s. Probe measurements at the inner divertor target suggest that the fluctuations in the particle flux to the inner target are strongest in the private flux region, and that the amplitude and distribution of these fluctuations are insensitive to the electron density of the core plasma, auxiliary heating and whether the plasma is single-null or double-null. It is found that the e-folding width of the time-average particle flux in the PFR decreases with increasing plasma current, but the fluctuations appear to be unaffected. At the outer divertor target, the fluctuations in particle and power fluxes are strongest in the SOL.
Rapid, all-optical crystal orientation imaging of two-dimensional transition metal dichalcogenide monolayers
Authors: David Sabrina N. , Zhai Yao , van der Zande Arend M. , O'Brien Kevin , Huang Pinshane Y. , Chenet Daniel A. , Hone James C. , Zhang Xiang , Yin Xiaobo
Published: September 2015

Two-dimensional (2D) atomic materials such as graphene and transition metal dichalcogenides (TMDCs) have attracted significant research and industrial interest for their electronic, optical, mechanical, and thermal properties. While large-area crystal growth techniques such as chemical vapor deposition have been demonstrated, the presence of grain boundaries and orientation of grains arising in such growths substantially affect the physical properties of the materials. There is currently no scalable characterization method for determining these boundaries and orientations over a large sample area. We here present a second-harmonic generation based microscopy technique for rapidly mapping grain orientations and boundaries of 2D TMDCs. We experimentally demonstrate the capability to map large samples to an angular resolution of ±1° with minimal sample preparation and without involved analysis. A direct comparison of the all-optical grain orientation maps against results obtained by diffraction-filtered dark-field transmission electron microscopy plus selected-area electron diffraction on identical TMDC samples is provided. This rapid and accurate tool should enable large-area characterization of TMDC samples for expedited studies of grain boundary effects and the efficient characterization of industrial-scale production techniques.
Asymmetric turbulent boundary layers along long thin circular cylinders at low-Re
Authors: Jordan Stephen A.
Published: September 2015

Notable deviations of the asymmetric turbulent boundary layer (TBL) statistics from their axisymmetric counterpart along long thin circular cylinders are vitally important to the naval and oceanographic jurisdictions. Although the available experimental evidence backs their concern, the realm of parametric variability (both geometric and kinematic) is extremely limited to draw solid conclusions. We know that only small misalignments which quantify less than one degree of incidence between the freestream and the straight cylinder axis can substantially alter the boundary layer thicknesses, mean axial velocity, and Reynolds stresses. But the statistical database is plainly inadequate to justify modifying the design tools that were founded solely for axisymmetric flow conditions. Herein, we begin rectifying this drawback by numerical means. The investigation centers on low turbulent Reynolds numbers (500 ≤ Rea ≤ 2500) and small angles-of-incidence (0° < α < 9°) to validate and complement the lions-share of the present database (Rea = aUo/ν, where a, Uo, and ν are the cylinder radius, freestream velocity, and kinematic viscosity, respectively). In particular, we numerically resolved the statistical responses of the TBL, mean axial velocity, Reynolds stresses, and skin friction under angles-of-incidence up to the earliest signs of Strouhal-type shedding. Clearly, the first prominent response was the thinning and thickening of the TBL along the respective windward and leeward sides to only a minor misalignment. Tilting the straight cylinder to slightly higher yaw angles transformed the TBL to a transitional boundary layer along the windward side for all simulated Reynolds numbers. For yaw angles α > 2°, all turbulent statistics of the asymmetric boundary layer were measurably dissimilar to those of the axisymmetric state.
Electronic structures and geometries of the XF3 (X = Cl, Br, I, At) fluorides
Authors: Sergentu Dumitru-Claudiu , Amaouch Mohamed , Pilmé Julien , Galland Nicolas , Maurice Rémi
Published: September 2015

The potential energy surfaces of the group 17 XF3 (X = Cl, Br, I, At) fluorides have been investigated for the first time with multiconfigurational wave function theory approaches. In agreement with experiment, bent T-shaped C2v structures are computed for ClF3, BrF3, and IF3, while we predict that an average D3h structure would be experimentally observed for AtF3. Electron correlation and scalar relativistic effects strongly reduce the energy difference between the D3h geometry and the C2v one, along the XF3 series, and in the X = At case, spin-orbit coupling also slightly reduces this energy difference. AtF3 is a borderline system where the D3h structure becomes a minimum, i.e., the pseudo-Jahn-Teller effect is inhibited since electron correlation and scalar-relativistic effects create small energy barriers leading to the global C2v minima, although both types of effects interfere.
Friction factor and mean velocity profile for pipe flow at high Reynolds numbers
Authors: Furuichi N. , Terao Y. , Wada Y. , Tsuji Y.
Published: September 2015

The friction factor for a fully developed pipe flow is examined at high Reynolds numbers up to ReD = 1.8 × 107 with high accuracy using the high Reynolds number actual flow facility “Hi-Reff” at AIST, NMIJ. The precise measurement of the friction factor is achieved by the highly accurate measurement of the flow rate, and the measurement uncertainty is estimated to be approximately 0.9% with a coverage factor of k = 2. The result examined here is obviously different from the Prandtl equation and the experimental results from the superpipe at Princeton University. The deviation of the present result from the Prandtl equation in the lower Reynolds number region is approximately 2.5% and −3% at the higher Reynolds number. For ReD < 2.0 × 105, the present friction factor obtained here agrees very well with the results at the superpipe, but a deviation is observed for ReD > 2.0 × 105, and it increases with the Reynolds number and reaches −6% at ReD = 1.0 × 107. The Kármán constant estimated by the measured friction factor is 0.385. Using inner scale variables estimated by the present friction factor, the velocity profile measured by laser Doppler velocimetry in the same measurement configuration for the friction factor is normalized in order to observe the consistency of the Kármán constants between both the measurements. The Kármán constant estimated by the measured velocity profiles for ReD > 3.0 × 105 is 0.382.
Reliable evaluation of magnetic properties of nanoparticle systems
Authors: Zucolotto B. , Plá Cid C. C. , Isoppo E. A. , Pasa A. A. , Duque J. G. S. , Folly W. S. D.
Published: September 2015

We obtain magnetic properties of magnesioferrite nanoparticles grew in a magnesiowstite crystalline matrix by analyzing the temperature dependence of the coercive field and the magnetization behavior. We introduce a modelling scheme to evaluate those properties in which the input variables are estimated from experimental data. The core of the method relies in sampling for nearby values in order to reach the optimal one that yields the smallest difference between calculated and experimental data. This procedure is efficient and our results match with the ones found in the literature. Thus, our method paves the way for a robust characterization of superparamagnetic nanoparticle materials.
Stability of the magnetized plasma-wall transition layer
Authors: Tskhakaya D. D. , Kos L.
Published: September 2015

Under the condition λD≪ρi≪ℓ (where λD is the Debye length, ρi is the ion gyro-radius, and ℓ is the smallest relevant collision length) and for the case of the obliquity of the magnetic field to the wall, the magnetized plasma-wall transition layer can be split into the following sub-layers: the Debye sheath (DS), the magnetic pre-sheath (MPS), and the collisional pre-sheath (CPS). Thanks to the above-mentioned condition, it is possible to investigate these sublayers independently of each other. In this paper, the kinetic theory of the stability of the MPS and the CPS is presented (for the DS, a small parameter, relevant for the development of the linear theory, is not found). The ion gas was assumed to move with a constant velocity, and the presence of such an ion beam made it necessary to modify the form of the Bohm–Chodura criterion and the behavior of the electric potential in the CPS. The instability rate was found to be proportional to the square root of the time.
Ion heating, burnout of the high-frequency field, and ion sound generation under the development of a modulation instability of an intense Langmuir wave in a plasma
Authors: Kirichok A. V. , Kuklin V. M. , Pryimak A. V. , Zagorodny A. G.
Published: September 2015

The development of one-dimensional parametric instabilities of intense long plasma waves is considered in terms of the so-called hybrid models, with electrons being treated as a fluid and ions being regarded as particles. The analysis is performed for both cases when the average plasma field energy is lower (Zakharov's hybrid model—ZHM) or greater (Silin's hybrid model—SHM) than the plasma thermal energy. The efficiency of energy transfer to ions and to ion perturbations under the development of the instability is considered for various values of electron-to-ion mass ratios. The energy of low-frequency oscillations (ion-sound waves) is found to be much lower than the final ion kinetic energy. We also discuss the influence of the changes in the damping rate of the high-frequency (HF) field on the instability development. The decrease of the absorption of the HF field inhibits the HF field burnout within plasma density cavities and gives rise to the broadening of the HF spectrum. At the same time, the ion velocity distribution tends to the normal distribution in both ZHM and SHM.
Terahertz generation by beating two Langmuir waves in a warm and collisional plasma
Authors: Zhang Xiao-Bo , Qiao Xin , Cheng Li-Hong , Tang Rong-An , Zhang Ai-Xia , Xue Ju-Kui
Published: September 2015

Terahertz (THz) radiation generated by beating of two Langmuir waves in a warm and collisional plasma is discussed theoretically. The critical angle between the two Langmuir waves and the critical wave-length (wave vector) of Langmuir waves for generating THz radiation are obtained analytically. Furthermore, the maximum radiation energy is obtained. We find that the critical angle, the critical wave-length, and the generated radiation energy strongly depend on plasma temperature and wave-length of the Langmuir waves. That is, the THz radiation generated by beating of two Langmuir waves in a warm and collisional plasma can be controlled by adjusting the plasma temperature and the Langmuir wave-length.
Three-dimensional two-fluid Braginskii simulations of the large plasma device
Authors: Fisher Dustin M. , Rogers Barrett N. , Rossi Giovanni D. , Guice Daniel S. , Carter Troy A.
Published: September 2015

The Large Plasma Device (LAPD) is modeled using the 3D Global Braginskii Solver code. Comparisons to experimental measurements are made in the low-bias regime in which there is an intrinsic E × B rotation of the plasma. In the simulations, this rotation is caused primarily by sheath effects and may be a likely mechanism for the intrinsic rotation seen in LAPD. Simulations show strong qualitative agreement with the data, particularly the radial dependence of the density fluctuations, cross-correlation lengths, radial flux dependence outside of the cathode edge, and camera imagery. Kelvin Helmholtz (KH) turbulence at relatively large scales is the dominant driver of cross-field transport in these simulations with smaller-scale drift waves and sheath modes playing a secondary role. Plasma holes and blobs arising from KH vortices in the simulations are consistent with the scale sizes and overall appearance of those in LAPD camera images. The addition of ion-neutral collisions in the simulations at previously theorized values reduces the radial particle flux by about a factor of two, from values that are somewhat larger than the experimentally measured flux to values that are somewhat lower than the measurements. This reduction is due to a modest stabilizing contribution of the collisions on the KH-modes driving the turbulent transport.
Controllable rectification of the axial expansion in the thermally driven artificial muscle
Authors: Yue Donghua , Zhang Xingyi , Yong Huadong , Zhou Jun , Zhou You-He
Published: September 2015

At present, the concept of artificial muscle twisted by polymers or fibers has become a hot issue in the field of intelligent material research according to its distinguishing advantages, e.g., high energy density, large-stroke, non-hysteresis, and inexpensive. The axial thermal expansion coefficient is an important parameter which can affect its demanding applications. In this letter, a device with high accuracy capacitive sensor is constructed to measure the axial thermal expansion coefficient of the twisted carbon fibers and yarns of Kevlar, and a theoretical model based on the thermal elasticity and the geometrical features of the twisted structure are also presented to predict the axial expansion coefficient. It is found that the calculated results take good agreements with the experimental data. According to the present experiment and analyses, a method to control the axial thermal expansion coefficient of artificial muscle is proposed. Moreover, the mechanism of this kind of thermally driven artificial muscle is discussed.
Simulations of x-ray speckle-based dark-field and phase-contrast imaging with a polychromatic beam
Authors: Zdora Marie-Christine , Thibault Pierre , Pfeiffer Franz , Zanette Irene
Published: September 2015

Following the first experimental demonstration of x-ray speckle-based multimodal imaging using a polychromatic beam [I. Zanette et al., Phys. Rev. Lett. 112(25), 253903 (2014)], we present a simulation study on the effects of a polychromatic x-ray spectrum on the performance of this technique. We observe that the contrast of the near-field speckles is only mildly influenced by the bandwidth of the energy spectrum. Moreover, using a homogeneous object with simple geometry, we characterize the beam hardening artifacts in the reconstructed transmission and refraction angle images, and we describe how the beam hardening also affects the dark-field signal provided by speckle tracking. This study is particularly important for further implementations and developments of coherent speckle-based techniques at laboratory x-ray sources.
Parabolic single-crystal diamond lenses for coherent x-ray imaging
Authors: Terentyev Sergey , Blank Vladimir , Polyakov Sergey , Zholudev Sergey , Snigirev Anatoly , Polikarpov Maxim , Kolodziej Tomasz , Qian Jun , Zhou Hua , Shvyd'ko Yuri
Published: September 2015

We demonstrate parabolic single-crystal diamond compound refractive lenses designed for coherent x-ray imaging resilient to extreme thermal and radiation loading expected from next generation light sources. To ensure the preservation of coherence and resilience, the lenses are manufactured from the highest-quality single-crystalline synthetic diamond material grown by a high-pressure high-temperature technique. Picosecond laser milling is applied to machine lenses to parabolic shapes with a ≃1 μm precision and surface roughness. A compound refractive lens comprised of six lenses with a radius of curvature R=200 μm at the vertex of the parabola and a geometrical aperture A=900 μm focuses 10 keV x-ray photons from an undulator source at the Advanced Photon Source facility to a focal spot size of ≃20×90 μm2 with a gain factor of ≃50−100.
Communication: When does a branched polymer become a particle?
Authors: Chremos Alexandros , Douglas Jack F.
Published: September 2015

Polymer melts with topologically distinct molecular structures, namely, linear chain, ring, and star polymers, are investigated by molecular dynamics simulation. In particular, we determine the mean polymer size and shape, and glass transition temperature for each molecular topology. Both in terms of structure and dynamics, unknotted ring polymers behave similarly to star polymers with f ≈ 5–6 star arms, close to a configurational transition point between anisotropic chains to spherically symmetric particle-like structures. These counter-intuitive findings raise fundamental questions regarding the importance of free chain-ends and chain topology in the packing and dynamics of polymeric materials.
Synthesis of Pb(OH)2/rGO Catalyst for Conversion of Sugar to Lactic Acid in Water
Authors: Hou Guan-hua , Yan Li-feng
Published: September 2015

Conversion of sugars from biomass to platform chemicals or fuels is an attracting topic for the utilization of biomass. Pb2+ ion is an efficient catalyst for the degradation of sugar to lactic acid, and it will be better to fix lead on a solid catalyst to reduce the risk of exposure of Pb2+ to environment. Here, a simple method has been developed to prepare a composite catalyst of Pb(OH)2/rGO, where the nanoparticles of Pb(OH)2 in size of 2–5 nm were prepared and fixed over the as-prepared reduced graphene oxide (rGO) nanosheets. The as-obtained catalyst showed an efficient catalytic activity to degrade glucose, fructose, and cellulose in aqueous solution, and the major product is lactic acid. The yield of lactic acid reached 58.7% when fructose was used as the feedstock (433 K and 2.5 MPa N2), and the catalyst can be recycled with high activity. Cellulose can also be directly converted into lactic acid in aqueous solution over the catalyst without extra acid or alkali, and the maximum yield of lactic acid is 31.7%.
Counting Radio-Krypton Atoms with a Laser
Authors: Yang Guo-min , Tu Le-yi , Cheng Cun-feng , Zhang Xiang-yang , Hu Shui-ming
Published: September 2015

Because of their unique chemical and physical properties, long-lived rare krypton radioisotopes, 85Kr and 81Kr, are ideal tracers for environmental samples, including air, groundwater and ice. Atom trap trace analysis (ATTA) is a new laser-based method for counting both 85Kr and 81Kr atoms with the abundance as low as 10−14 with micro-liters (STP) krypton gas. The entire system for rare radio-krypton measurement built at Hefei is presented, including the atom trap trace analysis instrument and sampling apparatus of gas extraction from water and krypton purification. Atmospheric 85Kr concentrations at different places in China were measured, showing a range of 1.3–1.6 Bq/m3, consistent with the northern hemispheric baseline. As a demonstration of the system, some shallow and deep groundwater samples in north and south China were sampled and dated.
Proverbe, transposabilité et forme forte
Authors: Gréa Philippe
Published: September 2015

How do speakers tease apart a simple generic sentence (les instituteurs ne gagnent pas beaucoup d’argent“school teachers do not make much money”) and a proverb (les cordonniers sont les plus mal chaussés,“shoemakers are always the worst shod”, eng.The cobbler’s children go barefoot)? From a formal viewpoint, these two utterance types are very close. Yet, only the latter is used in fields other than shoemaking. I account for this property, which I call ‘transposability’, by means of the following hypothesis, which also applies to proverbs and semantically transparent fixed expressions: a proverb correspond to a semantic form that consisting of a few semantic features organized as a semantic network. I adopt Sowa’s (1984) formalism and represent this network as a semic molecule (Rastier, 1989). To explain the transposability of the molecule, I use a notion fromGestaltheorie, namely the ‘strong form’. A proverb is freely transposable providing it lexicalizes a strong form, the strong form being a molecule with a high degree of internal coherence. Semantically speaking, I show that this coherence is a factor of both (a) an inherent or socially normed relational architecture and (b) an articulation without rests.
Shared Homes as an Alternative to Nursing Home Care: Impact of VA’s Medical Foster Home Program on Hospitalization
Authors: Levy Cari R , Alemi Farrokh , Williams Allison E , Williams Arthur R , Wojtusiak Janusz , Sutton Bryce , Giang Phan , Pracht Etienne , Argyros Lisa
Published: September 2015

Purpose of the Study

This study compares hospitalization rates for common conditions in the Veteran Affairs (VA) Medical Foster Home (MFH) program to VA nursing homes, known as Community Living Centers (CLCs).

Design and Methods

We used a nested, matched, case control design. We examined 817 MFH residents and matched each to 3 CLC residents selected from a pool of 325,031. CLC and MFH cases were matched on (a) baseline time period, (b) follow-up time period, (c) age, (d) gender, (e) race, (f) risk of mortality calculated from comorbidities, and (g) history of hospitalization for the selected condition during the baseline period. Odds ratio (OR) and related confidence interval (CI) were calculated to contrast MFH cases and matched CLC controls.

Results

Compared with matched CLC cases, MFH residents were less likely to be hospitalized for adverse care events, (OR = 0.13, 95% CI = 0.03–0.53), anxiety disorders (OR = 0.52, 95% CI = 0.33–0.80), mood disorders (OR = 0.57, 95% CI = 0.42–0.79), skin infections (OR = 0.22, 95% CI = 0.10–0.51), pressure ulcers (OR = 0.22, 95% CI = 0.09–0.50) and bacterial infections other than tuberculosis or septicemia (OR = 0.54, 95% CI = 0.31–0.92). MFH cases and matched CLC controls did not differ in rates of urinary tract infections, pneumonia, septicemia, suicide/self-injury, falls, other injury besides falls, history of injury, delirium/dementia/cognitive impairments, or adverse drug events. Hospitalization rates were not higher for any conditions studied in the MFH cohort compared with the CLC cohort.

Implications

MFH participants had the same or lower rates of hospitalizations for conditions examined compared with CLC controls suggesting that noninstitutional care by a nonfamilial caregiver does not increase hospitalization rates for common medical conditions.
Genomic variant calling: Flexible tools and a diagnostic data set
Authors: Lawrence Michael , Huntley Melanie A. , Stawiski Eric , Owen Art , Wu Thomas D , Goldstein Leonard D , Cao Yi , Degenhardt Jeremiah , Young Jason , Guillory Joseph , Heldens Sherry , Jackson Marlena , Seshagiri Somasekar , Gentleman Robert
Published: September 2015

1

The accurate identification of low-frequency variants in tumors remains an unsolved problem. To support characterization of the issues in a realistic setting, we have developed software tools and a reference dataset for diagnosing variant calling pipelines. The dataset contains millions of variants at frequencies ranging from 0.05 to 1.0. To generate the dataset, we performed whole-genome sequencing of a mixture of two Corriel cell lines, NA19240 and NA12878, the mothers of YRI (Y) and CEU (C) HapMap trios, respectively. The cells were mixed in three different proportions, 10Y/90C, 50Y/50C and 90Y/10C, in an effort to simulate the heterogeneity found in tumor samples. We sequenced three biological replicates for each mixture, yielding approximately 1.4 billion reads per mixture for an average of 64X coverage. Using the published genotypes as our reference, we evaluate the performance of a general variant calling algorithm, constructed as a demonstration of our flexible toolset, and make comparisons to a standard GATK pipeline. We estimate the overall FDR to be 0.028 and the FNR (when coverage exceeds 20X) to be 0.019 in the 50Y/50C mixture. Interestingly, even with these relatively well studied individuals, we predict over 475,000 new variants, validating in well-behaved coding regions at a rate of 0.97, that were not included in the published genotypes.