bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient Regular Perovskite Solar Cells Based on Pristine [70]Fullerene as Electron‐Selective Contact
Authors: Collavini Silvia , Kosta Ivet , Völker Sebastian F. , Cabanero German , Grande Hans J. , Tena‐Zaera Ramón , Delgado Juan Luis
Published: March 2016

[70]Fullerene is presented as an efficient alternative electron‐selective contact (ESC) for regular‐architecture perovskite solar cells (PSCs). A smart and simple, well‐described solution processing protocol for the preparation of [70]‐ and [60]fullerene‐based solar cells, namely the fullerene saturation approach (FSA), allowed us to obtain similar power conversion efficiencies for both fullerene materials (i.e., 10.4 and 11.4 % for [70]‐ and [60]fullerene‐based devices, respectively). Importantly, despite the low electron mobility and significant visible‐light absorption of [70]fullerene, the presented protocol allows the employment of [70]fullerene as an efficient ESC. The [70]fullerene film thickness and its solubility in the perovskite processing solutions are crucial parameters, which can be controlled by the use of this simple solution processing protocol. The damage to the [70]fullerene film through dissolution during the perovskite deposition is avoided through the saturation of the perovskite processing solution with [70]fullerene. Additionally, this fullerene‐saturation strategy improves the performance of the perovskite film significantly and enhances the power conversion efficiency of solar cells based on different ESCs (i.e., [60]fullerene, [70]fullerene, and TiO2). Therefore, this universal solution processing protocol widens the opportunities for the further development of PSCs.
Condition‐dependent ejaculate production affects male mating behavior in the common bedbugCimex lectularius
Authors: Kaldun Bettina , Otti Oliver
Published: March 2016

Food availability in the environment is often low and variable, constraining organisms in their resource allocation to different life‐history traits. For example, variation in food availability is likely to induce condition‐dependent investment in reproduction. Further, diet has been shown to affect ejaculate size, composition and quality. How these effects translate into male reproductive success or change male mating behavior is still largely unknown. Here, we concentrated on the effect of meal size on ejaculate production, male reproductive success and mating behavior in the common bedbugCimex lectularius. We analyzed the production of sperm and seminal fluid within three different feeding regimes in six different populations. Males receiving large meals produced significantly more sperm and seminal fluid than males receiving small meals or no meals at all. While such condition‐dependent ejaculate production did not affect the number of offspring produced after a single mating, food‐restricted males could perform significantly fewer matings than fully fed males. Therefore, in a multiple mating context food‐restricted males paid a fitness cost and might have to adjust their mating strategy according to the ejaculate available to them. Our results indicate that meal size has no direct effect on ejaculate quality, but food availability forces a condition‐dependent mating rate on males. Environmental variation translating into variation in male reproductive traits reveals that natural selection can interact with sexual selection and shape reproductive traits. As males can modulate their ejaculate size depending on the mating situation, future studies are needed to elucidate whether environmental variation affecting the amount of ejaculate available might induce different mating strategies.
IL‐12 and IL‐4 activate a CD39‐dependent intrinsic peripheral tolerance mechanism in CD8+ T cells
Authors: Noble Alistair , Mehta Hema , Lovell Andrew , Papaioannou Eleftheria , Fairbanks Lynette
Published: March 2016

Immune responses to protein antigens involve CD4+ and CD8+ T cells, which follow distinct programs of differentiation. Naïve CD8 T cells rapidly develop cytotoxic T‐cell (CTL) activity after T‐cell receptor stimulation, and we have previously shown that this is accompanied by suppressive activity in the presence of specific cytokines, i.e. IL‐12 and IL‐4. Cytokine‐induced CD8+ regulatory T (Treg) cells are one of several Treg‐cell phenotypes and are Foxp3− IL‐10+ with contact‐dependent suppressive capacity. Here, we show they also express high level CD39, an ecto‐nucleotidase that degrades extracellular ATP, and this contributes to their suppressive activity. CD39 expression was found to be upregulated on CD8+ T cells during peripheral tolerance induction in vivo, accompanied by release of IL‐12 and IL‐10. CD39 was also upregulated during respiratory tolerance induction to inhaled allergen and on tumor‐infiltrating CD8+ T cells. Production of IL‐10 and expression of CD39 by CD8+ T cells was independently regulated, being respectively blocked by extracellular ATP and enhanced by an A2A adenosine receptor agonist. Our results suggest that any CTL can develop suppressive activity when exposed to specific cytokines in the absence of alarmins. Thus negative feedback controls CTL expansion under regulation from both nucleotide and cytokine environment within tissues.
SALE‐Ing a MOF‐Based “Ship of Theseus.” Sequential Building‐Block Replacement for Complete Reformulation of a Pillared‐Paddlewheel Metal‐Organic Framework
Authors: Xu Yan , Vermeulen Nicolaas A. , Liu Yangyang , Hupp Joseph T. , Farha Omar K.
Published: March 2016

A complete structure and composition evolution of a pillared‐paddlewheel metal‐organic framework was achieved using a combination of solvent‐assisted linker exchange (SALE) and node transmetalation. In this example, each building unit – the di‐topic carboxylate strut, the di‐topic nitrogen‐based pillar, and the di‐zinc node – of the original metal‐organic framework is replaced in sequential fashion to produce a nickel‐based daughter metal‐organic framework with entirely different components.
Short lasting transient effects of a capsaicin 8% patch on nociceptor activation in humans
Authors: Landmann G. , Lustenberger C. , Schleinzer W. , Schmelz M. , Stockinger L. , Rukwied R.
Published: March 2016

Background

At high concentration, the TRPV‐1 agonist capsaicin de‐sensitizes nociceptors and reduces the intra‐epidermal nerve density.

Methods

We investigated the effects of a 5 × 10 cm capsaicin 8% patch on C‐ and A‐delta‐nociceptor activation in ten healthy subjects before and at days 1–3–7–21 after patch application. Thermal thresholds, infrared thulium‐YAG laser‐evoked potentials (LEP) and heat pain (numeric rating scale, NRS, 0–10), electrically induced pain (10 pulses, 1.5‐fold pain threshold intensity, five randomized series of 5–10–20–50–100 Hz), and axon‐reflex flare (laser Doppler imaging) were recorded.

Results

Thermal hypoesthesia developed upon capsaicin 8% treatment. Warmth detection thresholds increased at day 1–3, heat pain thresholds were increased by about 2.6 °C after day 3, and laser‐evoked heat pain remained significantly reduced for 7 days. Axon‐reflex flare responses (days 1–3), but not supra‐threshold electrically induced pain were significantly reduced by the capsaicin patch.

Conclusions

Axonal nociceptor function assessed by electrical excitability tests supplements threshold tests of nociceptive endings. The differential analgesic effects of 8% capsaicin patches may be attributed to the kinetics of capsaicin and the different depth of nociceptive nerve fibres, yet, the time course does not match the long‐lasting analgesia observed in neuropathic pain patients treated with the same patch.

What does this study add?

Axonal nociceptor function assessed by supra‐threshold electrical excitability tests did not coincide with capsaicin‐induced transduction changes supplementing threshold measures of terminal nociceptor endings.

Threshold measurements do not reflect the sustained effect of pain relief seen in neuropathic pain patients.

Capsaicin‐sensitive nociceptors responsible for spontaneous pain are either not specifically tested with currently available sensory stimulation protocols or have higher capsaicin sensitivity or slower recovery under neuropathic conditions.
Probabilistic seismic demand model for pounding risk assessment
Authors: Tubaldi Enrico , Freddi Fabio , Barbato Michele
Published: March 2016

Earthquake‐induced pounding of adjacent structures can cause severe structural damage, and advanced probabilistic approaches are needed to obtain a reliable estimate of the risk of impact. This study aims to develop an efficient and accurate probabilistic seismic demand model (PSDM) for pounding risk assessment between adjacent buildings, which is suitable for use within modern performance‐based engineering frameworks. In developing a PSDM, different choices can be made regarding the intensity measures (IMs) to be used, the record selection, the analysis technique applied for estimating the system response at increasing IM levels, and the model to be employed for describing the response statistics given the IM. In the present paper, some of these choices are analyzed and evaluated first by performing an extensive parametric study for the adjacent buildings modeled as linear single‐degree‐of‐freedom systems, and successively by considering more complex nonlinear multi‐degree‐of‐freedom building models. An efficient and accurate PSDM is defined using advanced intensity measures and a bilinear regression model for the response samples obtained by cloud analysis. The results of the study demonstrate that the proposed PSDM allows accurate estimates of the risk of pounding to be obtained while limiting the number of simulations required. Copyright © 2016 John Wiley & Sons, Ltd.
Concept and performance testing of a high‐capacity oil damper comprising multiple damper units
Authors: Yamamoto Masashi , Minewaki Shigeo , Nakahara Manabu , Tsuyuki Yasuo
Published: March 2016

There has been a significant increase in the size of building structures in recent years. Huge structures such as high‐rise buildings and large‐domed stadiums require high‐performance structural control, including the use of high‐capacity dampers, especially in an earthquake‐prone country like Japan. The objective of the present study was the enhancement of both human and structural safety in such structures through the development of a rate‐dependent type of damper with a high damping capacity. Among the various available types of rate‐dependent dampers, the authors focused on the oil damper owing to its stable performance against long‐duration vibrations. The target maximum damping force was 6000 kN, which is higher than that of any existing oil damper utilized in building structures. The authors developed a novel concept for achieving this high capacity while maintaining the size of the damper within acceptable dimensions from an architectural point of view. The concept involves the use of multiple damper units that produce mechanically parallel damping forces spatially arranged in series. As a prototype, a 1500‐kN oil damper was fabricated by combining three 500‐kN dampers. The 1500‐kN prototype damper was conceived as a full‐scale prototype of a damper that is more slender than comparable commercially available dampers in Japan, and as a scaled model of the proposed 6000‐kN damper.

Sinusoidal loading tests were conducted on the prototype damper using a frequency range of 0.1–1.5 Hz and a velocity range of 0.4–300 mm/s. The results confirmed that the damper produced the design damping forces. The results of earthquake loading tests also revealed that the damper exerted a stable damping force against a large earthquake and maintained its performance after the earthquake. The damper is particularly effective against earthquakes with long‐period components that could increase the temperature of a damper. This is afforded by its high heat capacity compared to conventional dampers.

Considering that the proposed 6000‐kN damper will generate a damping force that is about 2–3 times that of the strongest conventional oil damper, existing manufacturer test machines would be inadequate for evaluating its full performance characteristics. To address this issue, the authors also propose a test method for evaluating the overall damping force. The method is premised on the fact that the characteristic feature of the proposed damper is its combination of multiple damper units. The overall performance is thus evaluated using the test results for the individual damper units while the other dampers are bypassed. This method was verified by the results of the abovementioned sinusoidal loading tests, with the error for the 1500‐kN prototype damper found to be less than 5%. Copyright © 2016 John Wiley & Sons, Ltd.
Novel Metal Substrates for High Power Metal‐supported Solid Oxide Fuel Cells
Authors: Hwang C. S. , Tsai C. H. , Hwang T. J. , Chang C. L. , Yang S. F. , Lin J. K.
Published: March 2016

Novel high permeable porous Ni‐Mo substrates with different area densities of straight gas flow channels are successfully developed to improve the hydrogen fuel gas and the water byproduct diffusion in the anode and supporting substrate. Metal‐supported cell A, cell B and cell C with 5 × 5 cm2 supporting substrates are fabricated by atmospheric plasma spraying processes, these cells have the material structure of Ni‐Mo/LSCM (La0.75Sr0.25Cr0.5‐Mn0.5O3–δ)/NiO‐LDC(Ce0.55La0.45O2–δ)/SDC(Sm0.15Ce0.85O3–δ)/LSGM (La0.8Sr0.2Ga0.8Mg0.2O3–δ)/SSC(Sm0.5Sr0.5CoO3–δ). Cell A is supported by a conventional porous Ni‐Mo substrate without straight gas flow channels, cell B and cell C are supported respectively by the novel high permeable porous Ni‐Mo substrates with 1.5 and 2.73 channels per square centimeter. The power densities at 0.8 V and 750 °C are 550, 998 and 1,161 mW cm−2 for cell A, cell B and cell C respectively. The 100 h durability test at the constant current density of 400 mA cm−2 and 650 °C shows cell B and cell C have smaller degradation rates than cell A. The results obtained from AC impedance and circuit model analyses indicate that the electrolyte ohm and the cathode polarization resistances are significantly reduced by introducing straight gas flow channels into the supporting substrate.
Anisotropy characteristics of coal shrinkage/swelling and its impact on coal permeability evolution with CO2 injection
Authors: Liu Shimin , Wang Yi , Harpalani Satya
Published: March 2016

Coal deforms with gas depletion during coal bed methane (CBM) primary recovery and CO2 storage for purposes of sequestration or enhanced recovery. The sorption‐induced deformation associated with gas adsorption and desorption has been experimentally and theoretically studied and is considered to be a unique feature of coal. The results of a series of experimental measurements of coal deformation with gas injection and depletion using helium, methane, CO2, and various mixtures of methane and CO2 revealed that the coal sorption‐induced deformation exhibits anisotropy, with larger deformation in direction perpendicular to bedding than those parallel to the bedding planes. Furthermore, the deformation of coal is reversible for helium and methane with injection/depletion, but not for CO2. Aiming at improving the understanding of enhanced CBM process, a coal deformation experimental study on methane displacement with CO2 was performed as well, where incremental swelling was measured for each CO2 displacement step. The total induced swelling strain (1.68%) with CO2 saturation was less than that for pure CO2 injection‐induced strain (1.87%) at same pressure of 5.9 MPa (850 psi). The measured deformation with CO2 injection was applied to a constant‐volume based analytical coal permeability model, which is capable of accommodating the anisotropic sorption‐induced deformation. Based on the modeling results, it was found that application of isotropic deformation in permeability model can overestimate the permeability loss compared to anisotropic deformation. This demonstrates that the anisotropic coal deformation should be considered to predict the permeability behavior of CBM as well as CO2 sequestration/ECBM projects. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd
3D‐Printing inside the Glovebox: A Versatile Tool for Inert‐Gas Chemistry Combined with Spectroscopy
Authors: Lederle Felix , Kaldun Christian , Namyslo Jan C. , Hübner Eike G.
Published: March 2016

3D‐Printing with the well‐established ‘Fused Deposition Modeling’ technology was used to print totally gas‐tight reaction vessels, combined with printed cuvettes, inside the inert‐gas atmosphere of a glovebox. During pauses of the print, the reaction flasks out of acrylonitrile butadiene styrene were filled with various reactants. After the basic test reactions to proof the oxygen tightness and investigations of the influence of printing within an inert‐gas atmosphere, scope and limitations of the method are presented by syntheses of new compounds with highly reactive reagents, such as trimethylaluminium, and reaction monitoring via UV/VIS, IR, and NMR spectroscopy. The applicable temperature range, the choice of solvents, the reaction times, and the analytical methods have been investigated in detail. A set of reaction flasks is presented, which allow routine inert‐gas syntheses and combined spectroscopy without modifications of the glovebox, the 3D‐printer, or the spectrometers. Overall, this demonstrates the potential of 3D‐printed reaction cuvettes to become a complementary standard method in inert‐gas chemistry.
Correlative NAD(P)H‐FLIM and oxygen sensing‐PLIM for metabolic mapping
Authors: Kalinina Sviatlana , Breymayer Jasmin , Schäfer Patrick , Calzia Enrico , Shcheslavskiy Vladislav , Becker Wolfgang , Rück Angelika
Published: March 2016

Cellular responses to oxygen tension have been studied extensively. Oxygen tension can be determined by considering the phosphorescence lifetime of a phosphorescence sensor. The simultaneous usage of FLIM of coenzymes as NAD(P)H and FAD+ and PLIM of oxygen sensors could provide information about correlation of metabolic pathways and oxygen tension. We investigated correlative NAD(P)H‐FLIM and oxygen sensing‐PLIM for simultaneously analyzing cell metabolism and oxygen tension. Cell metabolism and pO2 were observed under different hypoxic conditions in squamous carcinoma cell cultures and in complex ex vivo systems. Increased hypoxia induced an increase of the phosphorescence lifetime of Ru(BPY)3 and in most cases a decrease in the lifetime of NAD(P)H which is in agreement to the expected decrease of the protein‐bound NAD(P)H during hypoxia.

Oxygen was modulated directly in the mitochondrial membrane. Blocking of complex III and accumulation of oxygen could be observed by both the decrease of the phosphorescence lifetime of Ru(BPY)3 and a reduction of the lifetime of NAD(P)H which was a clear indication of acute changes in the redox state of the cells. For the first time simultaneous FLIM/PLIM has been shown to be able to visualize intracellular oxygen tension together with a change from oxidative to glycolytic phenotype.

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Visible Raman excitation laser induced power and exposure dependent effects in red blood cells
Authors: Ahlawat Sunita , Kumar Nitin , Uppal Abha , Kumar Gupta Pradeep
Published: March 2016

We present results of Raman spectroscopic studies carried out on optically trapped red blood cells with Raman excitation wavelength in Q‐band region of the hemoglobin (Hb) absorption spectrum. The results obtained suggest that when exposed to the Raman excitation laser the RBCs get deoxygenated due to photo‐dissociation of oxygen from hemoglobin. For smaller exposure durations (5 s) the level of deoxygenation increases with an increase in power. However, for longer exposure durations the deoxygenated hemoglobin in the cells gets irreversibly oxidized to form a low spin ferric derivative of hemoglobin. The rate of oxidation depends upon the initial level of deoxygenation; higher the initial level of deoxygenation, higher is the rate of oxidation. However, the RBCs deoxygenated via oxygen deprivation (i.e. N2 purging) were found to be very stable against any laser induced effect. These observations suggests that in case of laser induced deoxygenation of RBCs the free oxygen generated by photo‐dissociation acts as the oxidizing agent and leads to oxidative damage of the RBCs.

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Real‐Time In Vivo Confocal Fluorescence Imaging of Prostate Cancer Bone‐Marrow Micrometastasis Development at the Cellular Level in Nude Mice
Authors: Miwa Shinji , Toneri Makoto , Igarashi Kentaro , Yano Shuya , Kimura Hiroaki , Hayashi Katsuhiro , Yamamoto Norio , Tsuchiya Hiroyuki , Hoffman Robert M.
Published: March 2016

In the present report, we demonstrate in vivo fluorescence imaging of bone‐marrow micrometastasis of prostate cancer at the cellular level in nude mice. PC‐3 human prostate cancer cells labeled with green fluorescent protein (GFP) or red fluorescent protein (RFP) were injected into the left ventricle or intratibial bone marrow of nude mice. PC‐3‐GFP, as well as selected high metastatic variants of PC‐3‐GFP, PC‐3‐GFP‐BM6 or PC‐3‐RFP were visualized by real‐time fluorescence imaging, to traffic and grow in the bone marrow. Formation of bone marrow micrometastasis could be imaged at the single‐cell level in live mice, using confocal microscopy. The ability to track bone marrow micrometastasis in real time at the cellular level provides a visual target for evaluating new therapeutics for this recalcitrant disease. J. Cell. Biochem. 117: 2533–2537, 2016. © 2016 Wiley Periodicals, Inc.
Correlation of Early Recurrence With In Vitro Adenosine Triphosphate Based Chemotherapy Response Assay in Pancreas Cancer With Postoperative Gemcitabine Chemotherapy
Authors: Park Joon Seong , Kim Jae Keun , Yoon Dong Sup
Published: March 2016

Introduction

Gemcitabine‐based regimens represent the standard systemic first line treatment in patients after pancreatic resection. However, the clinical impact of gemcitabine varies significantly in individuals because of chemoresistance. An in vitro adenosine triphosphate based chemotherapy response assay (ATP‐CRA) was designed to evaluate the sensitivity of cancer cells to various chemotherapeutic agents. This study investigated the correlation between in vitro gemcitabine sensitivity of tumor cells and early recurrence after curative resection.

Method

From January 2007 to December 2010, the ATP‐CRA for gemcitabine was tested in 64 patients surgically treated for pancreas cancer at Gangnam Severance Hospital, Seoul, Korea. We analyzed the relationship between chemosensitivity and early systemic recurrence in patients with pancreas cancer to predict disease‐free survival (DFS) after curative resection in pancreas cancer.

Result

The mean cell death rate (CDR) was 20.0 (±14.5) and divided into two groups according to the mean values of the CDR. Lymphovascular invasion was more frequently shown in gemcitabine resistance group without statistical significance. In univariate and multivariate analysis, advanced tumor stage and gemcitabine sensitive group (CDR ≥ 20) were identified as independent prognostic factors for DFS.

Conclusions

Gemcitabine sensitivity measured by ATP‐CRA was well correlated with in vivo drug responsibility to predict early recurrence following gemcitabine‐based adjuvant chemotherapy in patients with pancreas cancer.
E‐Cadherin Facilitates Protein Kinase D1 Activation and Subcellular Localization
Authors: Li Zhuo , Zhang Chuanyou , Chen Li , Li Guosheng , Qu Ling , Balaji K.C. , Du Cheng
Published: March 2016

Protein kinase D 1 (PKD1) is a serine/threonine kinase implicated in the regulation of diverse cellular functions including cell growth, differentiation, adhesion and motility. The current model for PKD1 activation involves diacylglycerol (DAG) binding to the C1 domain of PKD1 which results in the translocation of PKD1 to subcellular membranes where PKD1 is phosphorylated and activated by protein kinase C (PKC). In this study, we have identified a novel regulation of PKD1 activation. The epithelial cell membrane protein E‐cadherin physically binds to PKD1 which leads to a subcellular redistribution of PKD1. Furthermore, artificial targeting of PKD1 to the membrane leads to PKD1 activation in a PKC‐independent manner, indicating that membrane attachment is sufficient enough to activate PKD1. The presence of E‐cadherin dynamically regulates PKD1 activation by Bryostatin 1, a potent activator of PKD1, and its substrate phosphorylation specificity, implying a loss of E‐cadherin during cancer metastasis could cause the re‐distribution PKD1 and re‐wiring of PKD1 signaling for distinct functions. The knocking down of PKD1 in lung epithelial cell line A549 results in an epithelial to mesenchymal transition with changes in biomarker expression, cell migration and drug resistance. These results extend our previous understanding of PKD1 regulation and E‐cadherin signaling functions and may help to explain the diversified functions of PKD1 in various cells. J. Cell. Physiol. 231: 2741–2748, 2016. © 2016 Wiley Periodicals, Inc.
Identification of IgH gene rearrangement and immunophenotype in an animal model of Epstein–Barr virus‐associated lymphomas
Authors: Zhang Yang , Peng Xueqin , Tang Yunlian , Gan Xiaoning , Wang Chengkun , Xie Lu , Xie Xiaoli , Gan Runliang , Wu Yimou
Published: March 2016

Epstein–Barr virus (EBV) is a human oncogenic herpesvirus associated with lymphoma and nasopharyngeal carcinoma. Because the susceptible hosts of EB virus are limited to human and cotton‐top tamarins (Saguinus oedipus), there have been no appropriate animal models until the lymphoma model induced by EBV in human peripheral blood lymphocyte (hu‐PBL)/SCID chimeric mice was reported. However, it is still controversial whether the EBV‐associated lymphoma induced in hu‐PBL/SCID mice is a monoclonal tumor. In this study, we transplanted normal human peripheral blood lymphocytes (hu‐PBL) from six donors infected with EBV into SCID mice to construct hu‐PBL/SCID chimeric mice. The induced tumors were found in the mediastinum or abdominal cavity of SCID mice. Microscopic observation exhibited tumor cells that were large and had a plasmablastic, centroblastic or immunoblastic‐like appearance. Immunophenotyping assays showed the induced tumors were LCA‐positive, CD20/CD79a‐positive (markers of B cells), and CD3/CD45RO‐negative (markers of T cells). A human‐specific Alu sequence could be amplified by Alu‐PCR. This confirmed that induced tumors were B‐cell lymphomas originating from the transplanted human lymphocytes rather than mouse cells. EBER in situ hybridization detected positive signals in the nuclei of the tumor cells. Expression of EBV‐encoded LMP1, EBNA‐1, and EBNA‐2 in the tumors was significantly positive. PCR‐based capillary electrophoresis analysis of IgH gene rearrangement revealed a monoclonal peak and single amplification product in all six cases of induced tumors. This indicated that EBV can induce monoclonal proliferation of human B lymphocytes and promotes the development of lymphoma. J. Med. Virol. 88:1804–1813, 2016. © 2016 Wiley Periodicals, Inc.
Investigation of mechanical and tribological properties of tribo‐layer of Ni3Al matrix composites
Authors: Zhai Wenzheng , Shi Xiaoliang , Ibrahim Ahmed Mohamed Mahmoud , Xu Zengshi , Zhang Qiaoxin
Published: March 2016

The sliding wear of Ni3Al matrix composites with addition of 1.5 wt.% graphene nanoplates was studied through pin‐on‐disc wear testing. The spontaneous formation of a tribo‐layer produced during sliding wear was found to result in a deviation from Archard scaling and an unexpected high wear resistance that was not based on hardness alone. The tribo‐layer exhibited specific microstructural evolution with significant severe deformation and grain refinement after wear. In the grain refinement area, the accumulation of dislocations and an increase in misorientations were found to lead to strain hardening. For the plastic deformed area, reduction in the dislocation density inside the elongated ultrafine grains reduced strain hardening compared with the grain refinement area. It can be concluded that the deviation from Archard scaling occurred primarily as a result of the microstructural evolution of the tribo‐layer, resulting in the specific performance of mechanical and tribological properties of Ni3Al matrix composites under cyclic sliding wear process. Copyright © 2016 John Wiley & Sons, Ltd.
Microspheres Assembled from Chitosan‐Graft‐Poly(lactic acid) Micelle‐Like Core–Shell Nanospheres for Distinctly Controlled Release of Hydrophobic and Hydrophilic Biomolecules
Authors: Niu Xufeng , Liu Zhongning , Hu Jiang , Rambhia Kunal J. , Fan Yubo , Ma Peter X.
Published: March 2016

To simultaneously control inflammation and facilitate dentin regeneration, a copolymeric micelle‐in‐microsphere platform is developed in this study, aiming to simultaneously release a hydrophobic drug to suppress inflammation and a hydrophilic biomolecule to enhance odontogenic differentiation of dental pulp stem cells in a distinctly controlled fashion. A series of chitosan‐graft‐poly(lactic acid) copolymers is synthesized with varying lactic acid and chitosan weight ratios, self‐assembled into nanoscale micelle‐like core–shell structures in an aqueous system, and subsequently crosslinked into microspheres through electrostatic interaction with sodium tripolyphosphate. A hydrophobic biomolecule either coumarin‐6 or fluocinolone acetonide (FA) is encapsulated into the hydrophobic cores of the micelles, while a hydrophilic biomolecule either bovine serum albumin or bone morphogenetic protein 2 (BMP‐2) is entrapped in the hydrophilic shells and the interspaces among the micelles. Both hydrophobic and hydrophilic biomolecules are delivered with distinct and tunable release patterns. Delivery of FA and BMP‐2 simultaneously suppresses inflammation and enhances odontogenesis, resulting in significantly enhanced mineralized tissue regeneration. This result also demonstrates the potential for this novel delivery system to deliver multiple therapeutics and to achieve synergistic effects.

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Nanoscaled Biocoatings via Enzyme Mediated Autodeposition of Casein
Authors: Ruediger Arne A. , Bremser Wolfgang , Strube Oliver I.
Published: March 2016

Formation of nanoscaled monolayer protein structures via enzyme mediated autodeposition is investigated on the example of casein as protein and chymosin as enzyme. The key of this method is tethering of enzyme to the support. This ensures that destabilization and subsequent deposition of casein particles occurs only in direct proximity to the support surface. In this work, covalent enzyme coupling (with and without polymeric spacer) is applied to obtain high site‐specificity and self‐terminating properties of the autodeposition process. Direct covalent coupling results in defined deposition of monolayer films or single particles. Use of polymeric spacers increases the amount and radius of deposition by a factor of 4, due to higher mobility of enzyme and delayed self‐termination. Deposited casein structures show DMT‐moduli of 1.2–1.4 GPa, indicating higher flexibility compared to conventional casein coatings. Applications might arise in the fields of implantology and biosensor technology as well as renewable coatings.

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Adaptive Fourier tester for statistical estimation
Authors: Chen Qiuhui , Qian Tao , Li Yuan , Mai Weixiong , Zhang Xingfa
Published: March 2016

Based on Takenaka–Malmquist (TM) system, a new nonparametric estimator for probability density function is proposed. The TM estimation method is completely different from the existent density estimation methods in that the estimator depends on an approximate system with poles in a complex plane. Compared with the classic Fourier estimator, the TM estimator will offer more flexibility and adaptivity for real data due to the poles and nonlinearity of the phase of TM system. We compare the TM estimator with kernel, wavelet, and spline estimators by simulations. It shows that the introduced TM estimator is a more promising method than the existing and commonly used methods. Copyright © 2016 John Wiley & Sons, Ltd.
High‐contrast homogenization of linear systems of partial differential equations
Authors: Pallares‐Martín Antonio
Published: March 2016

We give some integrability conditions for the coefficients of a sequence of elliptic systems with varying coefficients in order to obtain the stability for homogenization. In the case of equations, it is well known that equi‐integrability and bound in L1 are enough for this purpose; however, this is based on the maximum principle, and then, it does not work for systems. Here, we use an extension of the Murat–Tartar div‐curl lemma because of M. Briane, J. Casado‐Díaz, and F. Murat in order to obtain the stability by homogenization for systems uniformly elliptic, with bounded coefficients in
, with N the dimension of the space. We also show that a weaker ellipticity condition can be assumed, but then, we need a stronger integrability for the coefficients. Copyright © 2016 John Wiley & Sons, Ltd.
Green tea polyphenol epigallocatechin‐3‐gallate improves epithelial barrier function by inducing the production of antimicrobial peptide pBD‐1 and pBD‐2 in monolayers of porcine intestinal epithelial IPEC‐J2 cells
Authors: Wan Murphy L. Y. , Ling K. H. , Wang M. F. , El‐Nezami Hani
Published: March 2016

Scope

Green tea has been known to confer numerous health benefits such as the prevention of cardiovascular disease, cancers, and obesity. Epigallocatechin‐3‐gallate (EGCG) is the major polyphenol present in green tea. Since EGCG is a food‐derived component, intestinal epithelial cells lining the gastrointestinal tract are constantly and directly exposed to EGCG. It is anticipated that EGCG can exert beneficial effects in the intestine. The aim of this study was to explore the protective effects of EGCG on intestinal barrier functions against bacterial translocation by using a porcine jejunal epithelial cell line, IPEC‐J2.

Methods and results

EGCG reduced bacterial translocation across IPEC‐J2 cell monolayers through the enhancement of the intestinal epithelial immunological barrier function by inducing secretion of antimicrobial peptides, porcine β‐defensins 1 and 2 (pBD‐1 and 2), which possessed higher antimicrobial activity against Escherichia coli. Further mechanistic studies demonstrated that EGCG upregulated pBD‐2 but not pBD‐1 via the p38 mitogen‐activated protein kinase dependent pathway. Such effects were not an “artifact” of hydrogen peroxide, catechin dimers, or other auto‐oxidation products generated from EGCG in cell culture media.

Conclusion

Our results imply that EGCG may be useful for prevention of intestinal disorders or bacterial infection in animals/humans.
Portfolio optimization for jump‐diffusion risky assets with common shock dependence and state dependent risk aversion
Authors: Zhang Caibin , Liang Zhibin
Published: March 2016

An optimal portfolio problem with one risk‐free asset and two jump‐diffusion risky assets is studied in this paper, where the two risky asset price processes are correlated through a common shock. Under the criterion of maximizing the mean‐variance utility of the terminal wealth with state dependent risk aversion, we formulate the time‐inconsistent problem within a game theoretic framework and look for subgame perfect Nash equilibrium strategy. Based on the technique of stochastic control theory and the corresponding extended Hamilton–Jacobi–Bellman equation, the closed‐form expressions of the optimal equilibrium strategy and value function are derived. Furthermore, we find that the optimal strategy, that is, the amount of money invested into the risky asset, is proportional to current wealth. Finally, some numerical examples are presented to show the impact of model parameters on the optimal results. Copyright © 2016 John Wiley & Sons, Ltd.
Experiences of informational needs and received information following a prenatal diagnosis of congenital heart defect
Authors: Carlsson Tommy , Bergman Gunnar , Wadensten Barbro , Mattsson Elisabet
Published: March 2016

Objective

To explore the need for information and what information was actually received following prenatal diagnosis of a congenital heart defect, in a country where termination of pregnancy beyond 22 weeks of gestation is not easily possible because of legal constraints.

Methods

Twenty‐six Swedish‐speaking pregnant women (n = 14) and partners (n = 12) were consecutively recruited for semi‐structured telephone interviews following the prenatal diagnosis of a congenital heart defect. Data were analyzed using content analysis.

Results

Although high satisfaction with the specialist information was described, the information was considered overwhelming and complex. Objective, honest, and detailed information about multiple subjects were needed, delivered repeatedly, and supplemented by written information/illustrations. Eighteen respondents had used the Internet to search for information and identified issues involving searching difficulties, low quality, and that it was too complex, insufficient, or unspecific. Those who terminated their pregnancy criticized that there was a lack of information about termination of pregnancy, both from health professionals and online sources, resulting in unanswered questions and unpreparedness.

Conclusion

Individuals faced with a prenatal diagnosis of a congenital heart defect need individualized and repeated information. These needs are not all adequately met, as individuals are satisfied with the specialist consultation but left with unanswered questions regarding pregnancy termination. © 2016 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.
Post‐crosslinking behavior of radiation crosslinked polyamide 66 during vibration welding
Authors: Leisen Christoph , Seefried Andreas , Drummer Dietmar
Published: March 2016

Vibration welding of radiation crosslinked polyamide 66 leads to a different relationship between process, structure, and properties. The radiation‐induced altered material properties result in an impeded squeeze flow and higher temperatures in the weld. It is possible to achieve weld strengths up the value of the base material. General theories cannot completely explain the adhesion for these crosslinked polymers. A possible explanation could be an additional temperature‐dependent adhesion mechanism. The high temperatures during vibration welding could affect the degree of crosslinking and lead to a post‐irradiation crosslinking of the polyamide. These additional links across the joining zone may be an additional adhesion mechanism and could explain the high weld strength of crosslinked polymers. The scope of this paper is to investigate the influence on the degree of crosslinking from material and welding parameters and to correlate these results with temperatures and weld strengths generated in a vibration welding process. POLYM. ENG. SCI., 56:735–742, 2016. © 2016 Society of Plastics Engineers
Effects of ultrahigh speed twin screw extrusion on the thermal and mechanical degradation of polystyrene
Authors: Farahanchi Azadeh , Malloy Robert , Sobkowicz Margaret J.
Published: March 2016

This article characterizes a novel twin screw extrusion (TSE) process with the capability of rotating at speeds up to 4500 rpm. The resulting extreme high shear rate is expected to result in molecular weight changes due to thermomechanical degradation of the polymeric materials being extruded, polystyrene (PS) in this case. In order to differentiate between mechanical and thermal factors affecting degradation of PS running at ultrahigh speeds and also to evaluate the relative importance of the two mechanisms, PS has been extruded at different screw speeds and different barrel temperatures with corresponding melt temperatures. Viscosity measurements and size exclusion chromatography measurements show the extent of degradation due to mechanical stress as a result of high screw rotational speeds. Furthermore, through analyzing the kinetics of PS depolymerization, the reaction rate and hypothetical apparent temperatures at each screw speed have been calculated. All results support the idea that the mechanical shear stress can be considered as the controlling factor of polymer degradation in ultrahigh speed TSE. POLYM. ENG. SCI., 56:743–751, 2016. © 2016 Society of Plastics Engineers
Synthesis and electrochemical properties of novel redox‐active polymers with anthraquinone moieties by Pd‐catalyzed cyclopolymerization of dienes
Authors: Motokuni Kenya , Häupler Bernard , Burges René , Hager Martin D. , Schubert Ulrich S.
Published: March 2016

Redox‐active polymers enhanced the focus of attention in the field of battery research in recent years. Anthraquinone is one of the most generic redox‐active functional compounds for battery applications, because the quinonide structure undergoes a redox reaction involving two electrons and features stable electrochemical behavior. Although various redox‐active polymers have been developed, the polymer backbone is mostly based on linear alkyl chains [e.g., poly(methacrylate)s, poly(ether)s]. Polymers featuring ring structures in the backbone are limited due to the restricted availability of suitable polymerization techniques [e.g., poly(norbornene)s by ROMP]. The cyclopolymerization of dienes with pendant redox‐active anthraquinone moieties by Pd catalysis represents a novel approach to synthesize redox‐active polymers featuring cyclic structures in the backbone. Electrochemical investigations, in particular cyclic voltammetry, of these new diene monomer, polymers and the corresponding polymer supported carbon paper composites were conducted in different organic electrolytes. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2184–2190
Purine salvage in Methanocaldococcus jannaschii: Elucidating the role of a conserved cysteine in adenine deaminase
Authors: Miller Danielle V. , Brown Anne M. , Xu Huimin , Bevan David R. , White Robert H.
Published: March 2016

Adenine deaminases (Ade) and hypoxanthine/guanine phosphoribosyltransferases (Hpt) are widely distributed enzymes involved in purine salvage. Characterization of the previously uncharacterized Ade (MJ1459 gene product) and Hpt (MJ1655 gene product) are discussed here and provide insight into purine salvage in Methanocaldococcus jannaschii. Ade was demonstrated to use either Fe(II) and/or Mn(II) as the catalytic metal. Hpt demonstrated no detectable activity with adenine, but was equally specific for hypoxanthine and guanine with a kcat/KM of 3.2 × 107 and 3.0 × 107 s− 1M− 1, respectively. These results demonstrate that hypoxanthine and IMP are the central metabolites in purine salvage in M. jannaschii for AMP and GMP production. A conserved cysteine (C127, M. jannaschii numbering) was examined due to its high conservation in bacterial and archaeal homologues. To assess the role of this highly conserved cysteine in M. jannaschii Ade, site‐directed mutagenesis was performed. It was determined that mutation to serine (C127S) completely abolished Ade activity and mutation to alanine (C127A) exhibited 10‐fold decrease in kcat over the wild type Ade. To further investigate the role of C127, detailed molecular docking and dynamics studies were performed and revealed adenine was unable to properly orient in the active site in the C127A and C127S Ade model structures due to distinct differences in active site conformation and rotation of D261. Together this work illuminates purine salvage in M. jannaschii and the critical role of a cysteine residue in maintaining active site conformation of Ade. Proteins 2016; 84:828–840. © 2016 Wiley Periodicals, Inc.
PK‐PD modeling of individual lesion FDG‐PET response to predict overall survival in patients with sunitinib‐treated gastrointestinal stromal tumor
Authors: Schindler E , Amantea MA , Karlsson MO , Friberg LE
Published: March 2016

Pharmacometric models were developed to characterize the relationships between lesion‐level tumor metabolic activity, as assessed by the maximum standardized uptake value (SUVmax) obtained on [18F]‐fluorodeoxyglucose (FDG) positron emission tomography (PET), tumor size, and overall survival (OS) in 66 patients with gastrointestinal stromal tumor (GIST) treated with intermittent sunitinib. An indirect response model in which sunitinib stimulates tumor loss best described the typically rapid decrease in SUVmax during on‐treatment periods and the recovery during off‐treatment periods. Substantial interindividual and interlesion variability were identified in SUVmax baseline and drug sensitivity. A parametric time‐to‐event model identified the relative change in SUVmax at one week for the lesion with the most pronounced response as a better predictor of OS than tumor size. Based on the proposed modeling framework, early changes in FDG‐PET response may serve as predictor for long‐term outcome in sunitinib‐treated GIST.
Effects of strontium concentration on structural, electronic, optical and thermodynamic properties of Pb1‐xSrxS
Authors: Zeroual Jazia , Labidi Salima , Labidi Malika , Bensalem Rachid
Published: March 2016

Theoretical investigations of structural, electronic, optical and thermodynamic properties of Pb1‐xSrxS with rocksalt crystal structure are reported, theoretical calculations are mainly based on the full potential linearized augmented plane wave (FP‐LAPW) method within the density functional theory (DFT) the generalized gradient approximation (GGA) of Perdew et al. The dependence of the lattice parameters, band gaps, dielectric constants, refractive indices, and mixing entropies on the composition x were analyzed mainly for x = 0, 0.25, 0.50, 0.75 and 1. The lattice constant for Pb1‐xSrxS exhibits a marginal deviation from the Vegard’s law. A significant deviation of the bulk modulus from linear concentration dependence was observed for the alloy. The microscopic origins of the gap bowing were detailed and explained. The composition dependence of the dielectric constant and refractive index was studied using different models. Besides, a regular‐solution model is used to investigate the thermodynamic stability of the alloys, which mainly indicates a phase miscibility gap. In fact and since there is a good agreement between our main results and the available experimental data for the binary compounds which may be a support for the results of the ternary alloys reported here for the first time. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of yellow/green II‐VI compound semiconductor laser diode structures on InP substrates
Authors: Kobayashi Ryohei , Takamatsu Shingo , Fukushima Koji , Kishino Katsumi , Nomura Ichirou
Published: March 2016

II‐VI‐compound‐semiconductor laser diode (LD) structures on InP substrates were investigated using device simulations and waveguide analysis. Our simulations showed that electron injection from the n‐cladding into the active layer is hindered by the n‐side barrier layer between the n‐cladding and active layer. Consequently, holes are not injected into the active layer but instead leak to the n‐side layers. It was shown that carrier injection efficiency can be improved by removing the n‐barrier. On the contrary, no large differences were observed between the optical confinement factors of the LD structures with and without the n‐barrier layer. In experiments, we have fabricated the LD structures with and without the n‐barrier layer on InP substrates using molecular beam epitaxy. The turn‐on voltage of the device without the n‐barrier was smaller than that for the device with the n‐barrier by about 5 V. Spontaneous orange emissions around 603 nm were observed for the devices without the n‐barrier. In contrast, no emission was observed for the devices with the n‐barrier. These results prove that the carrier injection into the active layer is enhanced by the removal of the n‐barrier, leading to improved the device performances. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)