bluuebunny/crossref_metadata_2025 huggingface dataset:
Single‐Step 3D Nanofabrication of Kinoform Optics via Gray‐Scale Focused Ion Beam Lithography for Efficient X‐Ray Focusing
Authors: Keskinbora Kahraman , Grévent Corinne , Hirscher Michael , Weigand Markus , Schütz Gisela
Published: January 2015

A kinoform lens is a highly efficient photonic device capable of focusing a wide range of electromagnetic radiation. Unfortunately, its realization without the need of any approximation remained elusive for a very long time. A direct, simple and precise fabrication method was still missing. Here, an efficient preparation scheme is presented for the first time. Two kinoform lenses made out of polycrystalline gold and nano‐crystalline PdSi, are successfully fabricated, thoroughly characterized and tested for their ultimate focusing performances at soft X‐ray energies. The fabrication is made possible by means of gray‐scale direct‐write ion beam lithography. A first ever 2D imaging is carried out via scanning transmission X‐ray microscopy achieving resolutions down to 60 nm. The diffraction efficiency is measured to be 77% to 89% of the theoretical value and is only limited by the strong absorption at the soft X‐ray energy range. The impact of materials selection on the final quality of the lens is emphasized. The overall results enable the production of almost perfect kinoform profiles with high precision. This opens unprecedented perspectives for the focusing of soft and hard X‐rays at very high efficiencies and paves the way toward new applications in a wider energy range.
Electrically Controlled Nanostructured Metasurface Loaded with Liquid Crystal: Toward Multifunctional Photonic Switch
Authors: Buchnev Oleksandr , Podoliak Nina , Kaczmarek Malgosia , Zheludev Nikolay I. , Fedotov Vassili A.
Published: January 2015

Achieving an efficient spectral tuning in liquid‐crystal (LC)‐loaded active photonic metamaterials has so far remained a challenge due to strong surface anchoring of LC molecules. This paper reports on a novel approach in the development of hybrid metamaterials that enables to overcome this problem and engage for the first time in‐plane switching of liquid‐crystal molecules on the nanoscale. Combined with the usual volume switching, it unlocks the full potential of the liquid crystals as a functional component of active metamaterial hybrids operating at optical frequencies. As a result, the resonant response of an active metasurface can now be controlled both in terms of its magnitude and wavelength with the spectral tunability approaching the theoretical limit of 9%. This mechanism of two‐way active switching of the hybrid metamaterial is also confirmed theoretically by simulating the distribution of the LC director around the metamaterial fabric.
Photoluminescent Materials for Solid‐State Lighting: State of the Art and Future Challenges
Authors: Meyer Jörg , Tappe Frank
Published: January 2015

The efficient generation of white light by phosphor‐converted LEDs (pcLEDs) suffers from a trade‐off between high color rendition, low correlated color temperatures, and luminous efficacy. While this is partially an inherent problem, it is also caused by the spectral efficiency of the materials used. The particular challenges for materials research lie, amongst the demanding general requirements, in finding very narrow‐band or line‐emitting materials: excitable with blue light, emitting in the near red. A way to design Mn(IV) activated line emitters is proposed, and methods for high‐throughput combinatorial syntheses are specified.
Three Colors Emission from S,N Co‐doped Graphene Quantum Dots for Visible Light H2 Production and Bioimaging
Authors: Qu Dan , Sun Zaicheng , Zheng Min , Li Jing , Zhang Yongqiang , Zhang Guoqiang , Zhao Haifeng , Liu Xingyuan , Xie Zhigang
Published: January 2015

A facile solvothermal route to synthesize S,N co‐doped graphene quantum dots (S,N‐GQDs) with unique optical properties is demonstrated. Three absorption bands are observed at 338, 467, and 557 nm, which is different from any previous reports. The photoluminescent spectra display emissions in three primary colors that are independent of the excitation wavelength, within the excitation wavelength ranges of 340–420 nm, 460–540 nm, and 560–620 nm. The PL excitation spectra indicate that each emission is related to a single excitation band. It is proposed that three independent luminescent centers coexist in S,N‐GQDs because the doping with S and N may change the chemical environment of the GQDs. However, energy‐transfer processes usually do not occur among the independent luminescent centers under different wavelength light excitation. Heteroatom‐doping of GQDs provides an attractive means of effectively tuning their optical properties for the purpose of exploiting new applications in visible‐light photocatalytic and bioimaging. S,N‐GQDs/TiO2 composites exhibit better hydrogen production activities under visible light (λ > 420 nm) than commercial TiO2 (P25), owing to the presence of characteristic absorption bands in the visible region. Furthermore, the S,N‐GQDs have a pronounced biocompatibility and bioimaging ability under long‐wavelengths excitation for live A549 cells.
Plasmonic Silver Supercrystals with Ultrasmall Nanogaps for Ultrasensitive SERS‐Based Molecule Detection
Authors: Tian Cuifeng , Deng Yonghui , Zhao Dongyuan , Fang Jixiang
Published: January 2015

Metallic periodic structures provide unique optical and photonic coupling effects. However, geometrically precise control of periodic structure is particularly challenging when studying scale at few nanometer. Here, a new class of highly ordered silver plasmonic supercrystals is successfully synthesized by means of a nanocasting process using ordered mesoporous silica as template. During the nanocasting via a chemical reduction, the diffusibility, viscosity, and strength of the reducing agents have an important influence on the formation of ordered superstructures. The silver superstructures demonstrate an excellent structural stability even after removing the silica template and a small nanogap of less than ≈2 nm between nanoparticles, which are very vital for light–matter coupling, giving rise to plasmonic hot spots. The silver plasmonic supercrystals exhibit an ultrahigh Raman enhancement with an average enhancement factor of ≈109 and an ultralow detection limit down to ≈0.1 × 10−15m for diverse chemical and biological molecules. This novel template strategy to fabricate periodic plasmonic nanostructures can lead to a new class of plasmonic nanostructures and open extraordinary potentials for diverse applications.
Effect of cumulative bortezomib dose on survival in multiple myeloma patients receiving bortezomib‐melphalan‐prednisone in the phase III VISTA study
Authors: Mateos María Victoria , Richardson Paul G. , Dimopoulos Meletios A. , Palumbo Antonio , Anderson Kenneth C. , Shi Hongliang , Elliott Jennifer , Dow Edward , van de Velde Helgi , Niculescu Liviu , San Miguel Jesús F.
Published: January 2015

This analysis, using data from the bortezomib‐melphalan‐prednisone (VMP) arm of the Phase III VISTA study, investigated whether increased cumulative bortezomib dose could improve overall survival (OS) in transplant‐ineligible patients with previously untreated multiple myeloma. Median cumulative bortezomib dose received by the 340 patients was 39 mg/m2; this was selected as the cut‐off for defining the dose groups to be compared for OS. Patient characteristics were well balanced between dose groups except for age. OS was significantly longer in the higher (≥39 mg/m2) versus lower (<39 mg/m2) cumulative bortezomib dose group (median 66.3 vs. 46.2 months; hazard ratio (HR) 0.533, P < 0.0001; age‐adjusted HR 0.561, P = 0.0002). To overcome confounding effects of early discontinuations/deaths, which were more common in the lower cumulative dose group (27 vs. 4% of patients discontinued due to adverse events (AEs) in the lower and higher cumulative dose groups, respectively), a landmark analysis was conducted at 180 days, eliminating patients who died or discontinued before this time from the analysis. OS from this landmark remained significantly longer in the higher dose group (median 60.4 vs. 50.3 months; HR 0.709, P = 0.0372). Thus, higher cumulative bortezomib dose, reflecting prolonged treatment duration and/or dose intensity, appears associated with improved OS. Approaches to achieve higher cumulative doses could include subcutaneous bortezomib administration, dose/schedule modifications, continuing therapy in responding patients, and proactive AE management. Am. J. Hematol. 90:314–319, 2015. © 2015 Wiley Periodicals, Inc.
Dicke‐type phase transition in a multimode optomechanical system
Authors: Mumford Jesse , O'Dell D. H. J. , Larson Jonas
Published: January 2015

We consider the “membrane in the middle” optomechanical model consisting of a laser pumped cavity which is divided in two by a flexible membrane that is partially transmissive to light and subject to radiation pressure. Steady state solutions at the mean‐field level reveal that there is a critical strength of the light‐membrane coupling above which there is a symmetry breaking bifurcation where the membrane spontaneously acquires a displacement either to the left or the right. This bifurcation bears many of the signatures of a second order phase transition and we compare and contrast it with that found in the Dicke model. In particular, by studying limiting cases and deriving dynamical critical exponents using the fidelity susceptibility method, we argue that the two models share very similar critical behaviour. For example, the obtained critical exponents indicate that they fall within the same universality class. Away from the critical regime we identify, however, some discrepancies between the two models. Our results are discussed in terms of experimentally relevant parameters and we evaluate the prospects for realizing Dicke‐type physics in these systems.
Procedural failure of chronic total occlusion percutaneous coronary intervention: Insights from a multicenter US registry
Authors: Sapontis James , Christopoulos Georgios , Grantham J. Aaron , Wyman R. Michael , Alaswad Khaldoon , Karmpaliotis Dimitri , Lombardi William L. , McCabe James M. , Marso Steven P. , Kotsia Anna P. , Rangan Bavana V. , Christakopoulos Georgios E. , Garcia Santiago , Thompson Craig A. , Banerjee Subhash , Brilakis Emmanouil S.
Published: January 2015

Background

The hybrid approach to chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has significantly increased procedural success rates, yet some cases still fail. We sought to evaluate the causes of failure in a contemporary CTO PCI registry.

Methods

We examined 380 consecutive patients who underwent CTO‐PCI at 4 high volume CTO PCI centers in the United States using the “hybrid” approach. Clinical, angiographic, complication, and efficiency outcomes were compared between successful and failed cases. Failed cases were individually reviewed by an independent reviewer to determine the cause of failure.

Results

Procedural success was 91.3%. Compared with patients in whom CTO PCI was successful, those in whom CTO PCI failed had similar baseline clinical characteristics, but were more likely to have longer occlusion length, more tortuosity, more proximal cap ambiguity and blunt stump, and higher mean J‐CTO scores (2.8 ± 1.1 vs. 3.5 ± 1.0, P < 0.001), and less likely to have collaterals suitable for the retrograde approach (66% vs. 45%, P = 0.021). Failure was due to a complication in 10 cases (30%). In the remaining 23 cases (70%) failure was due to inability to wire the lesion (n = 21, 4 of which were CTOs due to in‐stent restenosis), or poor antegrade flow after PCI (n = 5).

Conclusions

Compared with successful cases, failed CTO‐PCI cases are more likely to have higher J‐CTO scores, longer occlusion length, ambiguous proximal cap and no appropriate collaterals for retrograde crossing. Development of novel CTO crossing techniques is needed to further increase CTO PCI success rates. © 2015 Wiley Periodicals, Inc.
Deposition of Iridium Thin Films on Three‐Dimensional Structures With PE‐MOCVD
Authors: Yeh Chia‐Pin , Lisker Marco , Bläsing Jürgen , Khorkhordin Oleksandr , Kalkofen Bodo , Burte Edmund P.
Published: January 2015

Iridium thin films are deposited on sub‐micrometer three‐dimensional trench structures by plasma‐enhanced metal‐organic chemical vapor deposition (PE‐MOCVD). The iridium precursor used in this study is (ethylcyclopentadienyl)(1,5‐cyclooctadiene)iridium [Ir (EtCp)(1,5‐COD)]. Various process conditions at substrate temperatures from 300 °C to 450 °C, with and without plasma enhancement, are investigated and compared. Crystal structure of the deposited iridium films is analyzed by X‐ray diffraction (XRD). Step coverage of the deposited iridium films on three‐dimensional trench structures is analyzed by scanning electron microscopy (SEM). Surface morphology is quantitatively evaluated by atomic force microscopy (AFM) and the electrical resistivity of the deposited Ir films is measured by the four‐point probe method.
Doped Polycrystalline Silicon Thin Films Deposited on Glass from Trichlorosilane**
Authors: Benvenuto Ariel G. , Buitrago Román H. , Schmidt Javier A.
Published: January 2015

Atmospheric pressure (AP) thermal CVD is used to deposit thin poly‐Si films on glass substrates. Also produced are heterojunction solar cells carrying out the deposition on c‐Si wafers. A batch‐type hot‐wall reactor, employing SiHCl3 as a precursor, H2 as a carrier and reaction gas, BBr3 as a p‐type doping agent, and PCl3 as a n‐type doping agent, is used. The films obtained are homogeneous and well‐adhered to the substrate. Samples are structurally characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), reflectance spectroscopy in the UV‐vis region, X‐ray diffraction (XRD), and Raman spectroscopy (RS). The electrical characterization includes conductivity measurements as a function of temperature, and Hall effect measurements. For the p‐doped samples, XRD reveals a strong (220) preferential orientation of the films, while the n‐doped samples lack columnar structure or preferential orientation. RS and UV‐reflectance confirm a high crystalline fraction. Dark conductivity measurements as a function of temperature show that the films can be grown intrinsic, p‐type or n‐type. Activation energies between 0.61 and ∼0 eV are obtained, with reasonable values for the carrier mobilities. For the solar cells, relatively high values of VOC(∼507 mV) and JSC (∼29.6 mA cm−2) are measured. In conclusion, these results demonstrate the feasibility of directly depositing doped poly‐Si thin films on glass and c‐Si substrates at intermediate temperatures, with interesting characteristics for photovoltaic applications.
An Investigation into, and Improvement of, the Non‐uniformity of the Flow Field caused by the Pumping Effect in a Stagnation Flow CVD Reactor
Authors: Huang Mei‐Jiau , Weng Chien‐Chou
Published: January 2015

To deposit a film with uniform thickness, flow rectifiers are often used in a CVD reactor. Despite the effectiveness of these rectifiers, some degree of flow non‐uniformity persists within the reaction chamber, due to variations in the flow and buoyancy effects. Here, the non‐uniformity caused by the non‐axisymmetric pumping system, specifically a single and non‐annular pumping outlet, is investigated. A pumping liner, which directs the fluid mixture through embedded channels into a ring chamber connected to the pumping outlet, is used to improve flow uniformity. The flow resistance associated with each component in the pumping system is analyzed, then two carefully designed pumping liners, the channels of which either have non‐uniform radii or are unevenly spaced, are proposed. The pumping effect is balanced through the non‐uniform channel flow resistances, giving an axisymmetric flow field in the reaction chamber. This balance is confirmed in simulations.
Deletion of RIC8A in neural precursor cells leads to altered neurogenesis and neonatal lethality of mouse
Authors: Kask Keiu , Ruisu Katrin , Tikker Laura , Karis Kirstin , Saare Merly , Meier Riho , Karis Alar , Tõnissoo Tambet , Pooga Margus
Published: January 2015

RIC8A is a noncanonical guanine nucleotide exchange factor for a subset of Gα subunits. RIC8A has been reported in different model organisms to participate in the control of mitotic cell division, cell signalling, development and cell migration. Still, the function of RIC8A in the mammalian nervous system has not been sufficiently analysed yet. Adult mice express RIC8A in the brain regions involved in the regulation of memory and emotional behaviour. To elucidate the role of RIC8A in mammalian neurogenesis we have inactivated Ric8a in neural precursor cells using Cre/Lox system. As a result, the conditional knockout mice were born at expected Mendelian ratio, but died or were cannibalized by their mother within 12 h after birth. The cerebral cortex of the newborn Nes;Ric8aCKO mice was thinner compared to littermates and the basement membrane was discontinuous, enabling migrating neurons to invade to the marginal zone. In addition, the balance between the planar and oblique cell divisions was altered, influencing the neuron production. Taken together, RIC8A has an essential role in the development of mammalian nervous system by maintaining the integrity of pial basement membrane and modulating cell division. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 75: 984–1002, 2015
All you can eat: is food supply unlimited in a colonially breeding bird?
Authors: Hoi Herbert , Krištofík Ján , Darolová Alžbeta
Published: January 2015

Food availability is generally considered to determine breeding site selection and therefore plays an important role in hypotheses explaining the evolution of colony formation. Hypotheses trying to explain why birds join a colony usually assume that food is not limited, whereas those explaining variation in colony size suggest that food is under constraint. In this study, we investigate the composition and amount of food items not eaten by the nestlings and found in nest burrows of colonially nesting European bee‐eaters (Merops apiaster). We aimed to determine whether this unconsumed food is an indicator of unlimited food supply, the result of mistakes during food transfer between parents and chicks or foraging selectivity of chicks. Therefore, we investigated the amount of dropped food for each nest in relation to reproductive performance and parameters reflecting parental quality. Our data suggest that parents carry more food to the nest than chicks can eat and, hence, food is not limited. This assumption is supported by the facts that there is a positive relationship between dropped food found in a nest and the number of fledglings, nestling age, and chick health condition and that the amount of dropped food is independent of colony size. There is variation in the amount of dropped food within colonies, suggesting that parent foraging efficiency may also be an important determinant. Pairs nesting in the center of a colony performed better than those nesting on the edge, which supports the assumption that quality differences between parents are important as well. However, dropped food cannot be used as an indicator of local food availability as (1) within‐colony variation in dropped food is larger than between colony variation and, (2) the average amount of dropped food is not related to colony size.
Positioning activated carbon amendment technologies in a novel framework for sediment management
Authors: Kupryianchyk Darya , Rakowska Magdalena I , Reible Danny , Harmsen Joop , Cornelissen Gerard , van Veggel Marc , Hale Sarah E , Grotenhuis Tim , Koelmans Albert A
Published: January 2015

Contaminated sediments can pose serious threats to human health and the environment by acting as a source of toxic chemicals. The amendment of contaminated sediments with strong sorbents like activated C (AC) is a rapidly developing strategy to manage contaminated sediments. To date, a great deal of attention has been paid to the technical and ecological features and implications of sediment remediation with AC, although science in this field still is rapidly evolving. This article aims to provide an update on the recent literature on these features, and provides a comparison of sediment remediation with AC to other sediment management options, emphasizing their full-scale application. First, a qualitative overview of advantages of current alternatives to remediate contaminated sediments is presented. Subsequently, AC treatment technology is critically reviewed, including current understanding of the effectiveness and ecological safety for the use of AC in natural systems. Finally, this information is used to provide a novel framework for supporting decisions concerning sediment remediation and beneficial reuse. Integr Environ Assess Manag 2015;11:221–234. © 2015 SETAC

Key Points

Successful sediment management requires site-specific balancing of the potential benefits, adverse ecological effects, costs, time, and energy. Sediment treatment with AC is an efficient and safe innovative remediation method that can be applied in a wide range of settings, in situ or ex situ, alone or in combination with other approaches. A novel framework for decision-support concerning sediment remediation and re-use presented here will be a useful tool for planning the complex technological process of sediment remediation, before, during, and after remediation actions are taken.
Legg-Calvé-Perthes Disease Produces Chronic Hip Synovitis and Elevation of Interleukin-6 in the Synovial Fluid
Authors: Kamiya Nobuhiro , Yamaguchi Ryosuke , Adapala Naga Suresh , Chen Elena , Neal David , Jack Obrien , Thoveson Alec , Gudmundsson Paul , Brabham Case , Aruwajoye Olumide , Drissi Hicham , Kim Harry KW
Published: January 2015

Legg-Calvé-Perthes disease (LCPD) is a childhood hip disorder of ischemic osteonecrosis of the femoral head. Hip joint synovitis is a common feature of LCPD, but the nature and pathophysiology of the synovitis remain unknown. The purpose of this study was to determine the chronicity of the synovitis and the inflammatory cytokines present in the synovial fluid at an active stage of LCPD. Serial MRI was performed on 28 patients. T2-weighted and gadolinium-enhanced MR images were used to assess synovial effusion and synovial enhancement (hyperemia) over time. A multiple-cytokine assay was used to determine the levels of 27 inflammatory cytokines and related factors present in the synovial fluid from 13 patients. MRI analysis showed fold increases of 5.0 ± 3.3 and 3.1 ± 2.1 in the synovial fluid volume in the affected hip compared to the unaffected hip at the initial and the last follow-up MRI, respectively. The mean duration between the initial and the last MRI was 17.7 ± 8.3 months. The volume of enhanced synovium on the contrast MRI was increased 16.5 ± 8.5 fold and 6.3 ± 5.6 fold in the affected hip compared to the unaffected hip at the initial MRI and the last follow-up MRI, respectively. In the synovial fluid of the affected hips, IL-6 protein levels were significantly increased (LCPD: 509 ± 519 pg/mL, non-LCPD: 19 ± 22 pg/mL; p = 0.0005) on the multi-cytokine assay. Interestingly, IL-1β and TNF-α levels were not elevated. In the active stage of LCPD, chronic hip synovitis and significant elevation of IL-6 are produced in the synovial fluid. Further studies are warranted to investigate the role of IL-6 on the pathophysiology of synovitis in LCPD and how it affects bone healing. © 2015 American Society for Bone and Mineral Research
RECQL4 Regulates p53 Function In Vivo During Skeletogenesis
Authors: Lu Linchao , Harutyunyan Karine , Jin Weidong , Wu Jianhong , Yang Tao , Chen Yuqing , Joeng Kyu Sang , Bae Yangjin , Tao Jianning , Dawson Brian C , Jiang Ming-Ming , Lee Brendan , Wang Lisa L
Published: January 2015

RECQ DNA helicases play critical roles in maintaining genomic stability, but their role in development has been less well studied. Rothmund-Thomson syndrome, RAPADILINO, and Baller-Gerold syndrome are rare genetic disorders caused by mutations in the RECQL4 gene. These patients have significant skeletal developmental abnormalities including radial ray, limb and craniofacial defects. To investigate the role of Recql4 in the developing skeletal system, we generated Recql4 conditional knockout mice targeting the skeletal lineage. Inactivation of Recql4 using the Prx1-Cre transgene led to limb abnormalities and craniosynostosis mimicking the major bone findings in human RECQL4 patients. These Prx1-Cre+;Recql4fl/fl mice as well as Col2a1-Cre+;Recql4fl/fl mice exhibited growth plate defects and an increased p53 response in affected tissues. Inactivation of Trp53 in these Recql4 mutants resulted in genetic rescue of the skeletal phenotypes, indicating an in vivo interaction between Recql4 and Trp53, and p53 activation as an underlying mechanism for the developmental bone abnormalities in RECQL4 disorders. Our findings show that RECQL4 is critical for skeletal development by modulating p53 activity in vivo. © 2015 American Society for Bone and Mineral Research
Wnt Acts as a Prosurvival Signal to Enhance Dentin Regeneration
Authors: Hunter Daniel J , Bardet Claire , Mouraret Sylvain , Liu Bo , Singh Gurpreet , Sadoine Jérémy , Dhamdhere Girija , Smith Andrew , Tran Xuan Vinh , Joy Adrienne , Rooker Scott , Suzuki Shigeki , Vuorinen Annukka , Miettinen Susanna , Chaussain Catherine , Helms Jill A
Published: January 2015

Wnt proteins are lipid-modified, short-range signals that control stem cell self-renewal and tissue regeneration. We identified a population of Wnt responsive cells in the pulp cavity, characterized their function, and then created a pulp injury. The repair response was evaluated over time using molecular, cellular, and quantitative assays. We tested how healing was impacted by wound environments in which Wnt signaling was amplified. We found that a Wnt-amplified environment was associated with superior pulp healing. Although cell death was still rampant, the number of cells undergoing apoptosis was significantly reduced. This resulted in significantly better survival of injured pulp cells, and resulted in the formation of more tertiary dentin. We engineered a liposome-reconstituted form of WNT3A then tested whether this biomimetic compound could activate cells in the injured tooth pulp and stimulate dentin regeneration. Pulp cells responded to the elevated Wnt stimulus by differentiating into secretory odontoblasts. Thus, transiently amplifying the body's natural Wnt response resulted in improved pulp vitality. These data have direct clinical implications for treating dental caries, the most prevalent disease affecting mankind. © 2015 American Society for Bone and Mineral Research.
Activation of the Canonical Wnt Signaling Pathway Induces Cementum Regeneration
Authors: Han Pingping , Ivanovski Saso , Crawford Ross , Xiao Yin
Published: January 2015

Canonical Wnt signaling is important in tooth development but it is unclear whether it can induce cementogenesis and promote the regeneration of periodontal tissues lost because of disease. Therefore, the aim of this study is to investigate the influence of canonical Wnt signaling enhancers on human periodontal ligament cell (hPDLCs) cementogenic differentiation in vitro and cementum repair in a rat periodontal defect model. Canonical Wnt signaling was induced by (1) local injection of lithium chloride; (2) local injection of sclerostin antibody; and (3) local injection of a lentiviral construct overexpressing β-catenin. The results showed that the local activation of canonical Wnt signaling resulted in significant new cellular cementum deposition and the formation of well-organized periodontal ligament fibers, which was absent in the control group. In vitro experiments using hPDLCs showed that the Wnt signaling pathway activators significantly increased mineralization, alkaline phosphatase (ALP) activity, and gene and protein expression of the bone and cementum markers osteocalcin (OCN), osteopontin (OPN), cementum protein 1 (CEMP1), and cementum attachment protein (CAP). Our results show that the activation of the canonical Wnt signaling pathway can induce in vivo cementum regeneration and in vitro cementogenic differentiation of hPDLCs. © 2014 American Society for Bone and Mineral Research © 2015 American Society for Bone and Mineral Research
Obstructive Sleep Apnea and Metabolic Bone Disease: Insights Into the Relationship Between Bone and Sleep
Authors: Swanson Christine M , Shea Steven A , Stone Katie L , Cauley Jane A , Rosen Clifford J , Redline Susan , Karsenty Gerard , Orwoll Eric S
Published: January 2015

Obstructive sleep apnea (OSA) and low bone mass are two prevalent conditions, particularly among older adults—a section of the U.S. population that is expected to grow dramatically over the coming years. OSA, the most common form of sleep-disordered breathing, has been linked to multiple cardiovascular, metabolic, hormonal, and inflammatory derangements and may have adverse effects on bone. However, little is known about how OSA (including the associated hypoxia and sleep loss) affects bone metabolism. In order to gain insight into the relationship between sleep and bone, we review the growing information on OSA and metabolic bone disease and discuss the pathophysiological mechanisms by which OSA may affect bone metabolism/architecture. © 2015 American Society for Bone and Mineral Research
Investigation of local flow features in Istanbul. Part I: high‐resolution sensitivity simulations
Authors: Ezber Yasemin , Sen Omer Lutfi , Boybeyi Zafer , Karaca Mehmet
Published: January 2015

The three‐dimensional non‐hydrostatic mesoscale model, OMEGA (Operational Multiscale Environment model with Grid Adaptivity), is utilized to investigate the thermally driven local flows and their interaction with each other over the province of Istanbul, Turkey. Idealized case simulations are conducted in order to describe the contribution of sea–land breezes and urban heat island (UHI) circulation to the local flow over the city. The city of Istanbul is located between two water bodies, Black Sea in the north and Sea of Marmara in the south. A convergence zone is observed at about 1000 LST over the region due to the merge of two sea breezes that develop at both sides and advance towards inland areas. Investigation further indicates that the other geographic features of the city have substantial effects on the local flow. The Bosphorus Strait, which connects Black Sea to Sea of Marmara and divides the city into two parts, channels the flow. Although not significantly high and steep, the topography enhances the flow strength. Besides, urbanized regions in the south, by generating UHI circulation, prevent the inland penetration of the sea breeze that develops in the south. The numerical simulations reveal that the large‐scale wind direction controls the inland penetration of the sea breeze. One of the outstanding features of the local flows is that all hypothetical simulations including the Bosphorus indicate a strong fan‐like airflow in the immediate south of the strait. The flow is more intense in the northerly prevailing wind case. It is also found that stronger large‐scale flows (e.g. 2.5 and 10 m s−1) do not allow the formation of a sea breeze over the region. A warmer sea surface than land surface (about 2 °C) makes changes in the duration and extension of the land–sea breeze circulation. The duration of a land breeze circulation is long, and the southerly sea breeze is onset close to the south coast under the northeasterly flow conditions.
Species richness and distributions of boreal waterbird broods in relation to nesting and brood‐rearing habitats
Authors: Lewis Tyler L. , Lindberg Mark S. , Schmutz Joel A. , Bertram Mark R. , Dubour Adam J.
Published: January 2015

Identification of ecological factors that drive animal distributions allows us to understand why distributions vary temporally and spatially, and to develop models to predict future changes to populations–vital tools for effective wildlife management and conservation. For waterbird broods in the boreal forest, distributions are likely driven by factors affecting quality of nesting and brood‐rearing habitats, and the influence of these factors may extend beyond singles species, affecting the entire waterbird community. We used occupancy models to assess factors influencing species richness of waterbird broods on 72 boreal lakes, along with brood distributions of 3 species of conservation concern: lesser scaup (Aythya affinis), white‐winged scoters (Melanitta fusca), and horned grebe (Podiceps auritus). Factors examined included abundance of invertebrate foods (Amphipoda, Diptera, Gastropoda, Hemiptera, Odonata), physical lake attributes (lake area, emergent vegetation), water chemistry (nitrogen, phosphorus, chlorophyll a concentrations), and nesting habitats (water edge, non‐forest cover). Of the 5 invertebrates, only amphipod density was related to richness and occupancy, consistently having a large and positive relationship. Despite this importance to waterbirds, amphipods were the most patchily distributed invertebrate, with 17% of the study lakes containing 70% of collected amphipods. Lake area was the only other covariate that strongly and positively influenced species richness and occupancy of scaup, scoters, and grebes. All 3 water chemistry covariates, which provided alternative measures of lake productivity, were positively related to species richness but had little effect on scaup, scoter, and grebe occupancy. Conversely, emergent vegetation was negatively related to richness, reflecting avoidance of overgrown lakes by broods. Finally, nesting habitats had no influence on richness and occupancy, indicating that, at a broad spatial scale, brood distributions are largely driven by the presence of quality brood‐rearing lakes, not nesting habitats. Our findings are relevant to generating conservation plans or management goals; specifically, boreal lakes with abundant amphipods and surface areas >25 ha are important habitat for waterbird broods and merit conservation, especially given the patchy distribution of amphipods. Moreover, these high quality brood‐rearing lakes are much rarer, and thus more constraining, than are quality nesting habitats, which are likely abundant in the boreal. © 2015 The Wildlife Society.
InGaN/GaN dot‐in‐a‐wire: ultimate terahertz nanostructure
Authors: Sun Guan , Chen Ruolin , Ding Yujie J. , Nguyen Hieu P. T. , Mi Zetian
Published: January 2015

The terahertz (THz) radiation from InGaN/GaN dot‐in‐a‐wire nanostructures has been investigated. A submicrowatt THz signal is generated with just ten vertically stacked InGaN quantum dots (QDs) in each GaN nanowire. Based on the experimental results and analysis, a single quantum wire is expected to generate an output power as high as 10 pW, corresponding to 1 pW per dot. These structures are among the most efficient three‐dimensional quantum‐confined nanostructures for the THz emission. By applying a reverse bias along the wires in a light‐emitting device (LED) consisting of such nanostructures, the THz output power is increased more than fourfold. Based on THz and photoluminescence (PL) experiments, the mechanism for the THz emission is attributed to dipole radiation induced by internal electric fields and enhanced by external fields.

image
Comparison of Particle Size Techniques to Investigate Secondary Nucleation in HEMA‐Rich Latexes
Authors: Ocepek Martin , Soucek Mark D. , Berce Peter , Meng Lei
Published: January 2015

2‐Hydroxyethyl methacrylate (HEMA)‐rich latex is synthesized via a semibatch mono­mer‐starved emulsion polymerization process. Six emulsion polymerizations, containing 0–40 mol% HEMA in monomer composition, are synthesized and compared. Calculations of mass balances are made in order to predict final particle size and particle size development during the course of polymerization. Average particle sizes obtained by dynamic light scattering (DLS) are compared to ultrasound acoustic attenuation spectroscopy (UAAS) and transmission electron microscopy (TEM). The influence of HEMA on polymerization on the onset of secondary nucleation is evaluated using each technique. The DLS, TEM, and UAAS secondary nucleation data are compared to physical latex blends of small and large particles. The blend data are consistent with the secondary nucleation data. Additionally, conductivity and surface tension are monitored. TEM, atomic force microscope (AFM), and UAAS are found to be more appropriate methods than the widely used DLS for particle size and particle size distribution characterization in this system. Increasing HEMA content to 20 mol% results in formation of significant amount of secondary particles via proposed homogeneous nucleation of HEMA‐rich oligomers.

image
Distinct Melt Viscoelastic Properties of Novel Nanostructured and Microstructured Thermoplastic Elastomeric Blends from Polyamide 6 and Fluoroelastomer
Authors: Banerjee Shib Shankar , Kumar K. Dinesh , Bhowmick Anil K.
Published: January 2015

Distinct melt viscoelastic properties of novel polyamide 6 (PA6)/fluoroelastomer (FKM) thermoplastic elastomeric blends have been reported with special reference to the micro‐ and nano‐structures. In the entire frequency regime (0.0628–628 rad/s), nanostructured blend (the average dimension of the dispersed rubber phase, D ~ 90 nm) exhibited higher complex viscosity than the microstructured blend (D ~ 0.35 µm). The values of various interfacial parameters such as specific interfacial area per unit volume, interfacial tension, interaction parameter, interfacial thickness and infrared spectroscopic analysis confirmed the existence of more contact surface area between the blend components in nanostructured blend which increased intermolecular interaction. Due to the existence of greater restriction of mobility of the polymer chains, the relaxation time for the nanostructured blend was higher than that of the microstructured blend. The etched extrudate surface morphology was studied using field emission scanning electron microscopy and correlated with viscoelastic response of the blends.
Mathematical Modeling of Polyether Production from 1,3‐Propanediol: Accounting for Linear Oligomers
Authors: Cui Wei J. , McAuley Kimberley B. , Spence Rupert E. , Xie Tuyu
Published: January 2015

A mathematical model is developed to simulate the production of bio‐based polytrimethylene ether glycol (PO3G) using 1,3‐propanediol. The effect of super‐acid catalyst is accounted for in the model, as is mass transfer of small species (water, monomer, and propanal) and linear oligomers (dimer to heptamer). This model correctly predicts dynamic trends in concentrations of linear oligomers, but the predicted maxima in these concentrations appear slightly earlier than in the experimental data. Predictions of the degree of polymerization (DP) are improved compared with those from a previous model, where evaporation of linear oligomers was not considered. Additional model improvements, including accounting for the effects of cyclic oligomers, are suggested.
Orphan nuclear receptor TLX functions as a potent suppressor of oncogene‐induced senescence in prostate cancer via its transcriptional co‐regulation of the CDKN1A (p21WAF1/CIP1) and SIRT1 genes
Authors: Wu Dinglan , Yu Shan , Jia Lin , Zou Chang , Xu Zhenyu , Xiao Lijia , Wong Kam‐Bo , Ng Chi‐Fai , Chan Franky L
Published: January 2015

Oncogene‐induced senescence is an important tumour‐suppressing mechanism to prevent both premalignant transformation and cancer progression. Overcoming this process is a critical step in early cancer development. The druggable orphan nuclear receptor TLX (NR2E1) is characterized as an important regulator of neural stem cells and is also implicated in the development of some brain tumours. However, its exact functional roles in cancer growth regulation still remain unclear. Here we report that TLX can act as a promoter of tumourigenesis in prostate cancer by suppressing oncogene‐induced senescence. We determined that TLX exhibited an increased expression in high‐grade prostate cancer tissues and many prostate cancer cell lines. Functional studies revealed that TLX could perform an oncogenic function in prostate cancer cells, as its knockdown triggered cellular senescence and cell growth arrest in vitro and in vivo, whereas its over‐expression promoted the malignant growth of prostate cancer cells. Furthermore, enhancement of TLX activity, by either ectopic expression or ligand stimulation, could potently prevent doxorubicin‐induced senescence in prostate cancer cells and also allow prostatic epithelial cells to escape oncogene‐induced senescence induced either by activated oncogene H‐RasG12V or knockdown of tumour suppressor PTEN, via a mechanism of direct but differential transcriptional regulation of two senescence‐associated genes, repression of CDKN1A and transactivation of SIRT1. Together, our present study shows, for the first time, that TLX may play an important role in prostate carcinogenesis through its suppression of oncogene‐induced senescence, and also suggests that targeting the senescence‐regulatory TLX is of potential therapeutic significance in prostate cancer. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Isolation and characterisation of a Sphingomonas strain able to degrade the fungicide ortho‐phenylphenol
Authors: Perruchon Chiara , Patsioura Vasiliki , Vasileiadis Sotirios , Karpouzas Dimitrios G
Published: January 2015

BACKGROUND

Ortho‐phenylphenol (OPP) is a fungicide used in fruit packaging plants for the control of fungal infestations during storage. Its application leads to the production of large wastewater volumes which according to the European legislation should be treated on site. In spite of this, no efficient treatment systems are currently available, and the development of biological systems based on tailored‐made pesticide‐degrading inocula for the treatment of these wastewaters is an appealing solution.

RESULTS

Enrichment cultures from a soil collected from a wastewater disposal site resulted in the isolation of a pure Sphingomonas haloaromaticamans strain P3 able to degrade rapidly OPP and use it as an energy source. Its degrading capacity was dependent on the external supply of amino acids or on the presence of other bacteria that did not contribute to fungicide degradation. The isolated S. haloaromaticamans strain was able to metabolise up to 150 mg L−1 of OPP within 7 days, in a wide range of pH (4.5–9) and temperatures (4–37 °C), and in the presence of other pesticides (thiabendazole and diphenylamine) co‐used in the fruit packaging industry.

CONCLUSION

Overall, the OPP‐degrading bacterium isolated showed high potential for use in future biodepuration treatment systems and bioremediation strategies. © 2015 Society of Chemical Industry
Low propagation loss in GaN/AlGaN‐based ridge waveguides
Authors: Westreich Ohad , Katz Mordechai , Paltiel Yossi , Ternyak Orna , Sicron Noam
Published: January 2015

We report the fabrication and characterization of GaN/AlGaN ridge waveguides (WG). The “ridge” design was chosen to ensure low propagation loss. The fabrication process included four steps that could be easily regulated. GaN and AlGaN cladding layers were grown on a sapphire substrate by MOCVD. Shallow ridges were formed in the top cladding layer using ICP‐RIE. After etching, samples were diced and WG facets were formed by polishing the samples opposite sides. The propagation loss at 1.56 μm was evaluated by measuring Fabry–Perot resonances from end‐facet reflections. Losses as low as 1 dB/cm were measured for single mode WGs. Such low‐loss two‐dimensional WG could advance the use of GaN in integrated optoelectronics wave guiding components.

Schematic illustration of GaN ridge WG structure (left) and a SEM image of a 10 μm wide ridge WG structure (right).
Mental Health in Offspring of Traumatized Refugees with and without Post‐traumatic Stress Disorder
Authors: Muhtz Christoph , Wittekind Charlotte , Godemann Kathrin , Von Alm Christine , Jelinek Lena , Yassouridis Alexander , Kellner Michael
Published: January 2015

Intergenerational transmission of psychological trauma and the impact of parental post‐traumatic stress disorder (PTSD) on offspring are controversially discussed. We studied 50 offspring (36 women and 14 men, mean age 42.1 years) of refugees who were severely traumatized as children at the end of World War II. From these, 25 of the refugees currently suffered from chronic PTSD, and 25 had no PTSD. Parental PTSD status did not significantly influence mental health [as per the Symptom Checklist (SCL)‐90‐R] or quality of life (assessed by the 36‐item Short‐form Health Survey) in their children. In the entire sample, frequency of talking with the mother about the flight correlated with phobic anxiety (r = 0.67, p = 0.03). Interestingly, the stated burden of having a parent with a history of flight significantly (p < 0.05) correlated with almost all subscales of the SCL‐90‐R. These results in a non‐clinical sample do not support a specific role of parental PTSD in intergenerational trauma transmission. Our other remarkable, but preliminary, results need to be studied in larger samples using more subtle interaction or schema analyses. Copyright © 2015 John Wiley & Sons, Ltd.
Corrosion Investigation of Duplex Stainless Steels in Chlorinated Solutions
Authors: Kahram Mohaddeseh , Asnavandi Majid , Koshy Pramod , Sorrell Charles Christopher
Published: January 2015

The corrosion of duplex stainless steel 2205 was investigated both under service conditions and via an electrochemical study in chlorinated media. The steel sample surfaces showed pitting, crevice and selective dissolution, with the ferrite phase being more susceptible to dissolution in this media. The dissolution of MnS was identified to be a contributing factor for pitting corrosion, while electrochemical investigations revealed that the presence of hypochlorite ions caused a switching from a general corrosion phenomenon to a localized one.
Effects of management treatments on the carbon cycle of a cool‐temperate broad‐leaved deciduous forest and its potential as a bioenergy source
Authors: Matsushita Kayo , Tomotsune Mitsutoshi , Sakamaki Yoshiaki , Koizumi Hiroshi
Published: January 2015

The ecological effects of management treatments on the carbon cycles of secondary forests remain poorly understood. Here, we compared carbon cycles at three sites, a managed understory harvesting site (UH), a managed understory harvesting and litter raking site (LR), and an unmanaged site that served as a control (Um). We considered the harvests of understory and litter biomass as bioenergy sources, and made compartment models for the carbon cycle in units of carbon. Management increased the net primary production from 6.7 tC ha−1 year−1 for the Um site to 7.2 tC ha−1 year−1 for the UH site and 7.8 tC ha−1 year−1 for the LR site. Concurrently, management reduced the decomposition rate from 5.1 tC ha−1 year−1 for the Um site to 3.7 tC ha−1 year−1 for the UH site and 3.8 tC ha−1 year−1 for the LR site. Management also reduced fossil fuel use by 0.7 tC ha−1 year−1 for the UH site and 3.5 tC ha−1 year−1 for the LR site. These values suggest that harvesting had positive effects on net ecosystem production (NEP). In contrast, bioenergy use released 1.3 tC ha−1 year−1 into the atmosphere (in the form of carbon dioxide) for the UH site and 6.9 tC ha−1 year−1 for the LR site. These values suggest that harvesting had negative effects on NEP. We conclude that understory harvesting without litter raking (UH) maximized NEP at 2.9 tC ha−1 year−1. Our findings underscore the importance of a balanced ecological approach to forest management.