bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure and Optical Properties of Ca Silicide Films and Si/Ca3Si4/Si(111) Heterostructures
Authors: Galkin Nikolay Gennadievich , Bezbabnyi Dmitrii Aleksandrovich , Dotsenko Sergei Andreevich , Galkin Konstantin Nikolaevich , Chernev Igor Mikhailovich , Chusovitin Evgeniy Anatolievich , Nemes-Incze Peter , Dózsa Laszlo , Pécz Béla , Shamirzaev Timur Sezgitovich , Gutakovski Anton Konstantinovich
Published: March 2014

Thick, thin films and island of Ca silicide have been grown by Ca deposition onto 500 °C Si (111)7x7 substrates. The crystal structure of the grown layers strongly differs from the known Ca silicides (Ca2Si, CaSi, Ca5Si3, Ca14Si19, CaSi2). The phonon peaks at 389 and 416 cm-1 and the interband transition peaks (0.9-1.0, 1.3-1.7 and 2.0-2.5 eV) belongs to another silicide - Ca3Si4. Peculiarities of crystal, electronic, and phonon structure and optical properties of the grown Ca silicide films were measured by in situ and ex situ methods permit to state that the formed Ca silicide film has a composition Ca3Si4. Heterostructures with embedded Ca3Si4 films with different thicknesses have been formed atop the Ca3Si4 films by MBE and SPE at 500 °C. The observed density of pinholes with different sizes suggests the Si growth atop the Ca silicide follows a 3D mechanism. Photoluminescence was found first time in Si/Ca3Si4/Si (111) heterostructures.
Multiple CD11c+ Cells Collaboratively Express IL-1β To Modulate Stromal Vascular Endothelial Growth Factor and Lymph Node Vascular–Stromal Growth
Authors: Benahmed Fairouz , Chyou Susan , Dasoveanu Dragos , Chen Jingfeng , Kumar Varsha , Iwakura Yoichiro , Lu Theresa T.
Published: March 2014

Lymphadenopathy in autoimmune and other lymphoproliferative diseases is in part characterized by immunoblasts and vascular proliferation. The lymph node vasculature, along with the nonvascular stromal compartment, supports lymphocyte function, and targeting vascular–stromal expansion in inflamed nodes may modulate lymphocyte function in disease. CD11c+ cells are essential for vascular–stromal proliferation and the upregulation of vascular endothelial growth factor (VEGF) needed for vascular proliferation. However, targetable CD11c+ cell–derived molecular mediators, the identity of relevant CD11c+ cells, and whether CD11c+ cells directly stimulate VEGF-expressing stromal cells are poorly understood. In this study we show that CD11c+ CD11b+ CCR2-dependent monocytes and CCR7-dependent dendritic cells express IL-1β. IL-1β blockade, IL-1β deficiency in radiosensitive cells, and CCR2/CCR7 double deficiency but not single deficiency all attenuate immunization-induced vascular–stromal proliferation. gp38+ stromal fibroblastic reticular cells (FRCs) that express VEGF are enriched for Thy1+ cells and partially overlap with CCL21-expressing FRCs, and FRC VEGF is attenuated with IL-1β deficiency or blockade. IL-1β localizes to the outer borders of the T zone, where VEGF-expressing cells are also enriched. Ex vivo, CD11b+ cells enriched for IL-1β+ cells can directly induce cultured gp38+Thy1+ FRCs to upregulate VEGF. Taken together, these results suggest a mechanism whereby multiple recruited CD11c+ populations express IL-1β and directly modulate FRC function to help promote the initiation of vascular–stromal growth in stimulated lymph nodes. These data provide new insight into how CD11c+ cells regulate the lymph node vascular–stromal compartment, add to the evolving understanding of functional stromal subsets, and suggest a possible utility for IL-1β blockade in preventing inflammatory lymph node growth.
TLR4 Ligands Lipopolysaccharide and Monophosphoryl Lipid A Differentially Regulate Effector and Memory CD8+ T Cell Differentiation
Authors: Cui Weiguo , Joshi Nikhil S. , Liu Ying , Meng Hailong , Kleinstein Steven H. , Kaech Susan M.
Published: March 2014

Vaccines formulated with nonreplicating pathogens require adjuvants to help bolster immunogenicity. The role of adjuvants in Ab production has been well studied, but how they influence memory CD8+ T cell differentiation remains poorly defined. In this study we implemented dendritic cell–mediated immunization to study the effects of commonly used adjuvants, TLR ligands, on effector and memory CD8+ T cell differentiation in mice. Intriguingly, we found that the TLR4 ligand LPS was far more superior to other TLR ligands in generating memory CD8+ T cells upon immunization. LPS boosted clonal expansion similar to the other adjuvants, but fewer of the activated CD8+ T cells died during contraction, generating a larger pool of memory cells. Surprisingly, monophosphoryl lipid A (MPLA), another TLR4 ligand, enhanced clonal expansion of effector CD8+ T cells, but it also promoted their terminal differentiation and contraction; thus, fewer memory CD8+ T cells formed, and MPLA-primed animals were less protected against secondary infection compared with those primed with LPS. Furthermore, gene expression profiling revealed that LPS-primed effector cells displayed a stronger pro-memory gene expression signature, whereas the gene expression profile of MPLA-primed effector cells aligned closer with terminal effector CD8+ T cells. Lastly, we demonstrated that the LPS-TLR4–derived “pro-memory” signals were MyD88, but not Toll/IL-1R domain–containing adapter inducing IFN-β, dependent. This study reveals the influential power of adjuvants on the quantity and quality of CD8+ T cell memory, and that attention to adjuvant selection is crucial because boosting effector cell expansion may not always equate with more memory T cells or greater protection.
Airborne flux measurements of biogenic volatile organic compounds over California
Authors: Misztal P. K. , Karl T. , Weber R. , Jonsson H. H. , Guenther A. B. , Goldstein A. H.
Published: March 2014

Abstract. Biogenic Volatile Organic Compound (BVOC) fluxes were measured onboard the CIRPAS Twin Otter aircraft as part of the California Airborne BVOC Emission Research in Natural Ecosystem Transects (CABERNET) campaign during June 2011. The airborne virtual disjunct eddy covariance (AvDEC) approach used measurements from a PTR-MS and a wind radome probe to directly determine fluxes of isoprene, MVK + MAC, methanol, monoterpenes, and MBO over ∼10 000 km of flight paths focusing on areas of California predicted to have the largest emissions of isoprene. The Fast Fourier Transform (FFT) approach was used to calculate fluxes over long transects of more than 15 km, most commonly between 50 and 150 km. The Continuous Wavelet Transformation (CWT) approach was used over the same transects to also calculate "instantaneous" fluxes with localization of both frequency and time independent of non-stationarities. Vertical flux divergence of isoprene is expected due to its relatively short lifetime and was measured directly using "racetrack" profiles at multiple altitudes. It was found to be linear and in the range 5% to 30% depending on the ratio of aircraft altitude to PBL height (z / zi). Fluxes were generally measured by flying consistently at 400 ± 50 m (a.g.l.) altitude, and extrapolated to the surface according to the determined flux divergence. The wavelet-derived surface fluxes of isoprene averaged to 2 km spatial resolution showed good correspondence to Basal Emission Factor (BEF) landcover datasets used to drive biogenic VOC (BVOC) emission models. The surface flux of isoprene was close to zero over Central Valley crops and desert shrublands, but was very high (up to 15 mg m−2 h−1) above oak woodlands, with clear dependence of emissions on temperature and oak density. Isoprene concentrations of up to 8 ppb were observed at aircraft height on the hottest days and over the dominant source regions. While isoprene emissions from agricultural crop regions, shrublands, and coniferous forests were extremely low, high concentrations of methanol and monoterpenes were found above some of these regions. These observations demonstrate the ability to measure fluxes from specific sources by eddy covariance from an aircraft, and suggest the utility of measurements using fast response chemical sensors to constrain emission inventories and map out source distributions for a much broader array of trace gases than was observed in this study. This paper reports the first regional direct eddy covariance fluxes of isoprene. The emissions of VOCs measured from aircraft with 2 km spatial resolution can quantify the distribution of major sources providing the observations required for testing statewide emission inventories of these important trace gases. These measurements will be used in a future study to assess BVOC emission models and their driving variable datasets.
Odin–OSIRIS detection of the Chelyabinsk meteor
Authors: Rieger L. A. , Bourassa A. E. , Degenstein D. A.
Published: March 2014

Abstract. On 15 February 2013 an 11 000 ton meteor entered Earth's atmosphere southeast of Chelyabinsk, creating a large fireball at 23 km altitude. The resulting stratospheric aerosol loading was detected by the Ozone Mapping and Profiler Suite (OMPS) in a high-altitude polar belt. This work confirms the presence and lifetime of the stratospheric debris using the Optical Spectrograph and InfraRed Imaging System (OSIRIS) onboard the Odin satellite. Although OSIRIS coverage begins in mid-March, the measurements show a belt of enhanced scattering near 35 km altitude between 50° N and 70° N. Initially, enhancements show increased scattering of up to 15% over the background conditions, decaying in intensity and dropping in altitude until they are indistinguishable from background conditions by mid-May. An inversion is also attempted using the standard OSIRIS processing algorithm to determine the extinction in the meteoric debris.
Nitrate sources and dynamics in the salinized rivers and estuaries – a δ15N- and δ18O-NO3– isotope approach
Authors: Xue D. , Boeckx P. , Wang Z.
Published: March 2014

Abstract. To trace NO3– sources and assess NO3– dynamics in the salinized rivers and estuaries, three rivers (HH River, CB River and JY River) and two estuaries (HH Estuary and CJ Estuary) along the Bohai Bay (China) have been selected to determine DIN and δ15N and δ18O-NO3–. Upstream of the HH River NO3– was removed 30.9 ± 22.1% by aerobic denitrification, resulting from effects of the floodgate: limiting water exchange with downstream and prolonging water residence time to remove NO3–. Downstream of the HH River NO3– was removed 2.5 ± 13.3% by NO3– turnover processes. Conversely, NO3– was increased 36.6 ± 25.2% by external N source addition in the CB River and 34.6 ± 35.1% by in-stream nitrification in the JY River, respectively. The HH and CY Estuaries behaved mostly conservative excluding the sewage input in the CJ Estuary. Hydrodynamics in estuaries have been changed by the ongoing reclamation projects, aggravating the estuaries losing the attenuation function of NO3–.
Complete Surgical Removal of a Very Enlarged Pituitary Corticotroph Adenoma in a Dog
Authors: Fracassi Federico , Mandrioli Luciana , Shehdula Dardan , Diana Alessia , Grinwis Guy C.M. , Meij Björn P.
Published: March 2014

A 13 yr old castrated male vizsla was referred to the authors’ institute because of polyuria, polydipsia, polyphagia, and weight loss. Pituitary-dependent hypercortisolism (PDH) was diagnosed by hormone testing and adrenal and pituitary imaging. Computed tomography (CT) revealed a pituitary mass measuring 21 mm in width. Medical therapy was initiated with trilostane. Despite adequate control of the hypercortisolemia, the polyuria and polydipsia persisted and the dog developed neurologic signs due to the pituitary mass effect. Pituitary transsphenoidal debulking surgery was performed and immunocytochemistry confirmed a corticotroph adenoma. The dog survived for 13 mo after surgery. Postmortem examination revealed an empty fossa without pituitary remnants and the presence of a malignant pheochromocytoma in the right adrenal gland. This case report demonstrates, for the first time, that a large pituitary adenoma in the dog may be treated successfully by pituitary surgery.
Tolerability of Lomustine in Combination with Cyclophosphamide in Dogs with Lymphoma
Authors: Rassnick Kenneth M. , Bailey Dennis B. , Malone Erin K. , Flory Andrea B. , Kiselow Michael A. , Intile Joanne L.
Published: March 2014

This retrospective study describes toxicity associated with a protocol of lomustine (CCNU) and cyclophosphamide (CTX) in dogs with lymphoma. CCNU was administered per os (PO) at a targeted dosage of 60 mg/m2 body surface area on day 0, CTX was administered PO at a targeted dosage of 250 mg/m2 divided over days 0 through 4, and all dogs received prophylactic antibiotics. Ninety treatments were given to the 57 dogs included in the study. Neutropenia was the principal toxic effect, and the overall frequency of grade 4 neutropenia after the first treatment of CCNU/CTX was 30% (95% confidence interval, 19–43%). The mean body weight of dogs with grade 4 neutropenia (19.7 kg ± 13.4 kg) was significantly less than the mean body weight of dogs that did not develop grade 4 neutropenia (31.7 kg ± 12.4 kg; P = .005). One dog (3%) developed hematologic changes suggestive of hepatotoxicity. No dogs had evidence of either renal toxicity or hemorrhagic cystitis. Adverse gastrointestinal effects were uncommon. On the basis of the findings reported herein, a dose of 60 mg/m2 of CCNU combined with 250 mg/m2 of CTX (divided over 5 days) q 4 wk is tolerable in tumor-bearing dogs.
Short- and Long-Term Outcome of Dogs Following Surgical Correction of a Persistent Right Aortic Arch
Authors: Krebs Ingar A. , Lindsley Shauna , Shaver Stephanie , MacPhail Catriona
Published: March 2014

This study reports the survival to discharge, postdischarge survival, and long-term outcome of dogs following surgical correction of a persistent right aortic arch (PRAA). Information for 52 dogs, 28 dogs, and 23 dogs was available for analysis of survival to discharge, postdischarge survival, and long-term outcome, respectively. Ninety-two percent of dogs survived to the time of discharge and 18% of dogs surviving to discharge were euthanized within 2 mo of surgery. Breed, age at the time of presentation, and gender were not correlated with increased odds of death prior to discharge from the hospital. Long-term outcome for dogs was excellent in 30%, good in 57%, and poor in 13% of dogs. Although this study shows a relatively high mortality rate prior to discharge from the hospital and within 2 mo of surgical treatment, the long-term outcome is good or excellent in 87% of survivors. Dogs frequently display either residual clinical signs or require dietary modification long-term, but owner satisfaction is high.
Intrastriatal Transplantation of Adenovirus-Generated Induced Pluripotent Stem Cells for Treating Neuropathological and Functional Deficits in a Rodent Model of Huntington's Disease
Authors: Fink Kyle D. , Crane Andrew T. , Lévêque Xavier , Dues Dylan J. , Huffman Lucas D. , Moore Allison C. , Story Darren T. , DeJonge Rachel E. , Antcliff Aaron , Starski Phillip A. , Lu Ming , Lescaudron Laurent , Rossignol Julien , Dunbar Gary L.
Published: March 2014

Induced pluripotent stem cells (iPSCs) show considerable promise for cell replacement therapies for Huntington's disease (HD). Our laboratory has demonstrated that tail-tip fibroblasts, reprogrammed into iPSCs via two adenoviruses, can survive and differentiate into neuronal lineages following transplantation into healthy adult rats. However, the ability of these cells to survive, differentiate, and restore function in a damaged brain is unknown. To this end, adult rats received a regimen of 3-nitropropionic acid (3-NP) to induce behavioral and neuropathological deficits that resemble HD. At 7, 21, and 42 days after the initiation of 3-NP or vehicle, the rats received intrastriatal bilateral transplantation of iPSCs. All rats that received 3-NP and vehicle treatment displayed significant motor impairment, whereas those that received iPSC transplantation after 3-NP treatment had preserved motor function. Histological analysis of the brains of these rats revealed significant decreases in optical densitometric measures in the striatum, lateral ventricle enlargement, as well as an increase in striosome size in all rats receiving 3-NP when compared with sham rats. The 3-NP-treated rats given transplants of iPSCs in the 7- or 21-day groups did not exhibit these deficits. Transplantation of iPSCs at the late-stage (42-day) time point did not protect against the 3-NP-induced neuropathology, despite preserving motor function. Transplanted iPSCs were found to survive and differentiate into region-specific neurons in the striatum of 3-NP rats, at all transplantation time points. Taken together, these results suggest that transplantation of adenovirus-generated iPSCs may provide a potential avenue for therapeutic treatment of HD.
What does high and low have to do with it? Performance classification to identify health system factors associated with effective prevention of mother‐to‐child transmission of HIV delivery in Mozambique
Authors: Gimbel Sarah , Voss Joachim , Rustagi Alison , Mercer Mary Anne , Zierler Brenda , Gloyd Stephen , Coutinho Maria de Joana , Cuembelo Maria de Fatima , Sherr Kenneth
Published: March 2014

Introduction

Efforts to implement and take to scale highly efficacious, low‐cost interventions to prevent mother‐to‐child HIV transmission (pMTCT) have been a cornerstone of reproductive health services in sub‐Saharan Africa for over a decade. Yet efforts to increase access and utilization of these services remain far from optimal. This study developed and applied an approach to systematically classify pMTCT performance to identify modifiable health system factors associated with pMTCT performance which may be replicated in other pMTCT systems.

Methods

Facility‐level performance measures were collected at 30 sites over a 12‐month period and reviewed for consistency. Five combinations of three indicators (1. HIV testing; 2. CD4 testing; 3. antiretroviral prophylaxis and combined antiretroviral therapy initiation) were compared including a composite of all three, a combination of 1. and 3., and each individually. Approaches were visually assessed to describe facility performance, focusing on rank order consistency across high, medium and low categories. Modifiable and non‐modifiable factors were ascertained at each site and ranking process was reviewed to estimate association with facility performance through unadjusted Chi‐square tests and logistic regression. After describing factors associated with high versus low performing pMTCT clinics, the effect of inclusion of the 10 middle performers was assessed.

Results

The indicator most consistently associated with the reference composite indicator (HIV testing, antiretroviral prophylaxis and combined antiretroviral therapy) was the single measure of antiretroviral prophylaxis and combined antiretroviral therapy. Lower performing pMTCT clinics ranked consistently low across measurement strategies; high and middle performing clinics demonstrated more variability. Association between clinic characteristics and high pMTCT performance varied markedly across ranking strategies. Using the reference composite indicator, larger catchment area, higher number of institutional deliveries, onsite CD4 point‐of‐care capacity, and higher numbers of nurses and doctors were associated with high clinic performance while clinic location, NGO support, women's support group, community linkages patient‐tracking systems and stock‐outs were not associated with high performance.

Conclusions

Classifying high and low performance provided consistent results across ranking measures, though granularity was improved by aggregating middle performers with either high or low performers. Human resources, catchment size and utilization were positively associated with effective pMTCT service delivery.
Gate-all-around floating-gate memory device with triangular poly-Si nanowire channels
Authors: Tsai Jung-Ruey , Lee Ko-Hui , Lin Horng-Chih , Huang Tiao-Yuan
Published: March 2014

A novel gate-all-around (GAA) poly-Si floating-gate (FG) memory device with triangular nanowire (NW) channels was fabricated and characterized in this work. The enhanced electric field around the corners of the NW channels boosts more electrons tunneling through the tunnel oxide layer during programming and erasing (P/E) processes, and thus the operation voltage markedly decreases. Furthermore, the nonlocalized trapping feature characteristic of the FG makes the injection of electrons easier during the programming operation, which was demonstrated by technology computer-aided design (TCAD) simulations.
An 8 channel, 20 V output CMOS switching driver with 3.3 V power supply using triple-well biasing techniques for integrated MEMS device control
Authors: Takayasu Motohiro , Shirane Atsushi , Lee Sangyeop , Yamane Daisuke , Ito Hiroyuki , Mi Xiaoyu , Inoue Hiroaki , Nakazawa Fumihiko , Ueda Satoshi , Ishihara Noboru , Masu Kazuya
Published: March 2014

An 8 channel output switching driver has been implemented for integrated micro-electro-mechanical systems (MEMS) device control using the 0.18 µm CMOS process technology. The driver can output 20 V switching signals for 1 nF capacitive loads with a 3.3 V power supply. The switching time is less than 100 µs. To obtain a high output voltage that exceeds the transistors’ and capacitors’ breakdown voltages, a new charge pump and a discharge circuit, using optimal transistor-well-biasing techniques for triple-well-structured n-MOS transistors, were investigated, and the circuit parameters were also optimized to obtain high-speed switching.
A CMOS image sensor using column-parallel forward noise-canceling circuitry
Authors: Li Tsung-Ling , Wakashima Shunichi , Goda Yasuyuki , Kuroda Rihito , Sugawa Shigetoshi
Published: March 2014

In this paper, a new column-parallel analog readout architecture, which is composed of a high-gain amplifier, a forward noise-canceling circuitry (FNC), and sample-and-hold (S/H) capacitors, has been presented for low-noise CMOS image sensors (CIS). A FNC has been proposed to provide a sharp noise-filtering for high-frequency noise arising from the readout signal chain, which effectively reduces random noise of the pixel source follower and column amplifier. In order to keep the high-sensitivity and high-dynamic range output, dual-gain readout chains have been adopted. A prototype 400H × 250V CIS using the readout architecture with the FNC was fabricated in a 0.18 µm 1-poly 3-metal CMOS process with pinned-photodiodes. The experimental results revealed the input-referred noise of the proposed readout architecture was 65 µVrms, which has been reduced by 24% compared to that of the conventional readout architecture.
Performance improvement of GaN-based metal–semiconductor–metal photodiodes grown on Si(111) substrate by thermal cycle annealing process
Authors: Lin Jyun-Hao , Huang Shyh-Jer , Su Yan-Kuin
Published: March 2014

A simple thermal cycle annealing (TCA) process was used to improve the quality of GaN grown on a Si substrate. The X-ray diffraction (XRD) and etch pit density (EPD) results revealed that using more process cycles, the defect density cannot be further reduced. However, the performance of GaN-based metal–semiconductor–metal (MSM) photodiodes (PDs) prepared on Si substrates showed significant improvement. With a two-cycle TCA process, it is found that the dark current of the device was only 1.46 × 10−11 A, and the photo-to-dark-current contrast ratio was about 1.33 × 105 at 5 V. Also, the UV/visible rejection ratios can reach as high as 1077.
Study on AlGaN/GaN growth on carbonized Si substrate
Authors: Sakamoto Tatsuya , Wakabayashi Shigeaki , Takahashi Tokio , Ide Toshihide , Shimizu Mitsuaki , Ubukata Akinori , Satou Takayuki , Tabuchi Toshiya , Takanashi Yoshifumi
Published: March 2014

AlGaN/GaN films were grown on carbonized Si(111) substrates, which were employed to prevent impurities such as residual Ga atoms from reacting and deteriorating the surface of Si substrates. The cleaning process for the flow channel in metal organic chemical vapor deposition (MOCVD) could effectively be eliminated by using this carbonized Si substrate, and high-quality AlGaN/GaN films were obtained.
Enhanced Electrocatalysis for Hydrogen Evolution Reactions from WS2 Nanoribbons
Authors: Lin Jian , Peng Zhiwei , Wang Gunuk , Zakhidov Dante , Larios Eduardo , Yacaman Miguel Jose , Tour James M.
Published: March 2014

A facile route is developed to boost the electrocatalytic activity of WS2
by chemically unzipping WS2 nanotubes to form WS2 nanoribbons (NRs) with increased edge content. Analysis indicates that the hydrogen evolution reaction activity is strongly associated with the number of exposed active edge sites. The formation of WS2 NRs is an effective route for controlling the electrochemical properties of the 2D dichalcogenides, enabling their application in electrocatalysis.
Hydrophobic microblock length effect on the interaction strength and binding capacity between a partially hydrolyzed microblock hydrophobically associating polyacrylamide terpolymer and surfactant
Authors: Guo Yongjun , Liang Yan , Yang Xueshan , Feng Rusen , Song Rutong , Zhou Jingda , Gao Feilong
Published: March 2014

Poly(acrylamide/sodium acrylate/N‐dodecyl acrylamide)s [poly(AM/NaAA/C12AM)s] with different hydrophobic microblock lengths (NH's) were prepared by the micellar copolymerization of acrylamide and sodium acrylate with a low amount of N‐dodecyl acrylamide (0.2 mol %), and the molecular structure was characterized by Fourier transform infrared spectroscopy, 1H‐NMR, and static light scattering. A combination of experiments involving viscosity measurement, fluorescence, and conductometry was applied to investigate the effect of NH on the interaction strength and binding capacity between poly(AM/NaAA/C12AM)s and C12H25SO4Na [sodium dodecyl sulfate (SDS)]. The viscosity, I3/I1 (the intensity ratio of the third vibrational band to the first band of pyrene molecules), and conductivity of the mixed system of copolymers with SDS all had different variation trends with the concentration of SDS. The binding capacity of the copolymers with SDS was calculated according to quantitative differences between the critical micelle concentration of the pure SDS solution and the mixed system. All of the results show that the interaction strength of SDS with the copolymers rose, and the binding capacity decreased with increasing NH. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40633.
Foam stability and polymer phase morphology of flexible polyurethane foams synthesized from castor oil
Authors: Sharma Chandan , Kumar Sanjay , Unni A. Raman , Aswal Vinod K. , Rath Sangram K. , Harikrishnan G.
Published: March 2014

Foam stability and segmented polymeric phase morphology of polyurethane foams synthesized partially and completely from castor oil are investigated. Preliminary analysis of the impact of alterations in the polymeric phase on macroscopic stress dissipation in foams is also carried out. The stability and morphology show unique trends depending on the concentration of castor oil used in foam synthesis. While low and intermediate concentrations of castor oil does not significantly affect the foaming process; at high concentrations, the volumetrically expanding liquid matrix remains in a nonequilibrium state during the entire foaming period, resulting in significant foam decay from top. This increases the final foam cell density and decreases the plateau border thickness at bottom. In the polymeric phase of castor oil based foams, the fraction of monodentate urea increases at the cost of non‐hydrogen bonded urea. These monodentate urea domains undergo flocculation in foams synthesized completely from castor oil, thus prominently modifying the segmented morphology. The glass transition temperature of soft segments of partially substituted foams shows moderate increase, with indications of phase mixing between the polyether and castor oil generated urethane domains. Foams synthesized entirely from castor oil have significant sol fraction due to unreacted oligomers. The microscopic alterations in polymeric phase reduce the elastic recovery of partially substituted castor oil foams compared to its viscous dissipation under an applied stress. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40668.
Thiocarbohydrazide‐modified chitosan as anticorrosion and metal ion adsorbent
Authors: Li Man‐Lin , Li Rong‐Hua , Xu Juan , Han Xiang , Yao Tian‐Yu , Wang Jinyi
Published: March 2014

To explore the application of chitosan (CS) derivatives in anticorrosion and adsorption, thiocarbohydrazide‐modified chitosan (TCHECS) derivative was synthesized and characterized. The preliminary electrochemical measurements of the behaviors of 304 steel and Cu sheets in 2% HAc (v/v) containing TCHECS, chitosan (CS), and hydrazine cross‐linked epoxy‐N‐phthaloylchitosan (HECS) had been performed. The short‐term electrochemical tests show that the new compound can act as a mixed‐type metal anticorrosion inhibitor; its inhibition efficiency is 88% when the concentration was 30 mg/L. The preliminary adsorption studies for sorbents TCHECS and HECS on a metal ion mixture aqueous solution were also performed. The results show that TCHECS can absorb As (V), Ni (II), Cu (II), Cd (II), and Pb (II) efficiently at pH 9; the removal of the As (V), Ni (II), Cu (II), Cd (II), and Pb (II) are around 55.6–99.9%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40671.
Camelina oil‐ and linseed oil‐based polymers with bisphosphonate crosslinks
Authors: Kasetaite Sigita , Ostrauskaite Jolita , Grazuleviciene Violeta , Svediene Jurgita , Bridziuviene Danguole
Published: March 2014

Natural oils are the attractive biobased alternatives for petroleum derived chemicals in the production of polymers. A series of new biodegradable polymers based on epoxidized camelina oil was synthesized and investigated. The thermal, mechanical, swelling properties, hydrolysis, biodegradation, and bioresistance of the camelina oil‐based polymers with bisphosphonate crosslinks were studied and compared with those of the analogous polymers based on epoxidized linseed oil. The dependence of the polymer properties on the density of crosslinks was observed. The obtained results showed that the properties of the camelina oil‐based polymers are comparable with those of the linseed oil‐based polymers and that camelina oil is a promising starting material for the synthesis of polymers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40683.
Process Development from Laboratory to Miniplant Scale: Hydroformylation of 1‐Dodecene in Thermomorphic Solvent Systems
Authors: Zagajewski Michael , Dreimann Jens , Behr Arno
Published: March 2014

Die Anwendung thermomorpher Mehrkomponenten‐Lösungsmittelsysteme in chemischen Prozessen kann die Effektivität und Wirtschaftlichkeit homogen katalysierter Verfahren erheblich steigern. Die Ausnutzung einer stark temperaturabhängigen Mischungslücke von ausgewählten Lösungsmittelkombinationen ermöglicht eine einphasige Reaktionsführung und eine anschließende Katalysatorabtrennung mittels Flüssig/Flüssig‐Zweiphasentechnik. Dieses elegante Katalyseprinzip wurde am Beispiel der rhodiumkatalysierten Hydroformylierung von 1‐Dodecen in einer kontinuierlich betriebenen Miniplant im Langzeitbetrieb untersucht.
Genomic replacement of nativeCobitis lutheriwith introducedC. tetralineatathrough a hybrid swarm following the artificial connection of river systems
Authors: Kwan Ye‐Seul , Ko Myeong‐Hun , Won Yong‐Jin
Published: March 2014

River connections via artificial canals will bring about secondary contacts between previously isolated fish species. Here, we present a genetic consequence of such a secondary contact betweenCobitisfish species,C. lutheriin the Dongjin River, andC. tetralineatain the Seomjin River in Korea. The construction of water canals about 80 years ago has unidirectionally introducedC. tetralineatainto the native habitat ofC. lutheri, and then these species have hybridized in the main stream section of the Dongjin River. According to the divergence population genetic analyses ofDNAsequence data, the two species diverged about 3.3 million years ago, which is interestingly coincident with the unprecedented paleoceanographic change that caused isolations of the paleo‐river systems in northeast Asia due to sea‐level changes around the late Pliocene. Multilocus genotypic data of nine microsatellites and three nuclear loci revealed an extensively admixed structure in the hybrid zone with a high proportion of various post‐F1 hybrids. Surprisingly, pure nativeC. lutheriwas absent in the hybrid zone in contrast to the 7% of pureC. tetralineata. Such a biased proportion must have resulted from the dominant influence of continually introducingC. tetralineataon the nativeC. lutheriwhich has no supply of natives from other tributaries to the hybrid zone due to numerous low‐head dams. In addition, mating experiments indicated that there is no discernible reproductive isolation between them. All the results suggest that the gene pool of nativeC. lutheriis being rapidly replaced by that of continually introducingC. tetralineatathrough a hybrid swarm for the last 80 years, which will ultimately lead to the genomic extinction of natives in this hybrid zone.
Anomalous electrophoretic migration of short oligodeoxynucleotides labelled with 5′‐terminal Cy5 dyes
Authors: Killelea Tom , Saint‐Pierre Christine , Ralec Céline , Gasparutto Didier , Henneke Ghislaine
Published: March 2014

By using a fluorescent exonuclease assay, we reported unusual electrophoretic mobility of 5′‐indocarbo‐cyanine 5 (5′‐Cy5) labelled DNA fragments in denaturing polyacrylamide gels. Incubation time and enzyme concentration were two parameters involved in the formation of 5′‐Cy5‐labelled degradation products, while the structure of the substrate was slightly interfering. Replacement of positively charged 5′‐Cy5‐labelled DNA oligonucleotides (DNA oligos) by electrically neutral 5′‐carboxyfluorescein (5′‐FAM) labelled DNA oligos abolished the anomalous migration pattern of degradation products. MS analysis demonstrated that anomalously migrating products were in fact 5′‐labelled DNA fragments ranging from 1 to 8 nucleotides. Longer 5′‐Cy5‐labelled DNA fragments migrated at the expected position. Altogether, these data highlighted, for the first time, the influence of the mass/charge ratio of 5′‐Cy5‐labelled DNA oligos on their electrophoretic mobility. Although obtained by performing 3′ to 5′ exonuclease assays with the family B DNA polymerase from Pyrococcus abyssi, these observations represent a major concern in DNA technology involving most DNA degrading enzymes.
Stage at breast cancer diagnosis and distance from diagnostic hospital in a periurban setting: A South African public hospital case series of over 1,000 women
Authors: Dickens Caroline , Joffe Maureen , Jacobson Judith , Venter Francois , Schüz Joachim , Cubasch Herbert , McCormack Valerie
Published: March 2014

Advanced stage at diagnosis contributes to low breast cancer survival rates in sub‐Saharan Africa. Living far from health services is known to delay presentation, but the effect of residential distance to hospital, the radius at which this effect sets in and the women most affected have not been quantified. In a periurban South African setting, we examined the effect of a geographic information system (GIS)‐measured straight‐line distance, from a patient's residence to diagnostic hospital, on stage at diagnosis in 1,071 public‐sector breast cancer patients diagnosed during 2006–2012. Generalized linear models were used to estimate risk ratios for late stage (stage III/IV vs. stage I/II) associated with distance, adjusting for year of diagnosis, age, race and socioeconomic indicators. Mean age of patients was 55 years, 90% were black African and diagnoses were at stages I (5%), II (41%), III (46%) and IV (8%). Sixty‐two percent of patients with distances >20 km (n = 338) had a late stage at diagnosis compared to 50% with distances <20 km (n = 713, p = 0.02). Risk of late stage at diagnosis was 1.25‐fold higher (95% CI: 1.09, 1.42) per 30 km. Effects were pronounced in an underrepresented group of patients over age 70. This positive stage–distance association held to 40 km, and plateaued or slightly reversed in patients (9%) living beyond this distance. Studies of woman and the societal and healthcare‐level influences on these delays and on the late stage at diagnosis distribution are needed to inform interventions to improve diagnostic stage and breast cancer survival in this and similar settings.
Tolerability of the capsaicin 8% patch following pretreatment with lidocaine or tramadol in patients with peripheral neuropathic pain: A multicentre, randomized, assessor‐blinded study
Authors: Jensen T.S. , Høye K. , Fricová J. , Vanelderen P. , Ernault E. , Siciliano T. , Marques S.
Published: March 2014

Background

Application of the capsaicin 8% patch is associated with treatment‐related discomfort. Consequently, pretreatment for 60 min with anaesthetic cream is recommended; however, this may be uncomfortable and time consuming.

Methods

We conducted a multicentre, randomized (1:1), assessor‐blinded study in patients with peripheral neuropathic pain to assess tolerability of the capsaicin patch following topical lidocaine (4%) or oral tramadol (50 mg) pretreatment. The primary endpoint was the proportion of patients tolerating capsaicin patch application (ability to receive ≥90% of a 60‐min application). Numeric Pain Rating Scale (NPRS) scores were assessed before, during and after treatment.

Results

Overall, 122 patients were included (61 per arm). The capsaicin patch was tolerated by 121 patients. Tolerability of the capsaicin patch was similar following pretreatment with lidocaine and tramadol. Following patch application, pain levels increased up to 55 min (change from baseline of 1.3 for lidocaine and 1.4 for tramadol). After patch removal, tramadol‐treated patients experienced greater pain relief up to the end of day 1; in the evening, mean changes in NPRS scores from baseline were 0 for lidocaine and −1 for tramadol. Proportions of patients reporting increases of ≥2 NPRS points or >33% from baseline at one or more time point(s) on the day of treatment were similar between arms. Adverse event incidence was comparable between arms.

Conclusions

Capsaicin 8% patch tolerability was similar in the two arms, with comparable results for most secondary endpoints. Tramadol given 30 min before patch application should be considered as an alternative pretreatment option in patients receiving capsaicin patch treatment.
Polycaprolactone–thiophene‐conjugated carbon nanotube meshes as scaffolds for cardiac progenitor cells
Authors: Wickham Abeni M. , Islam M. Mirazul , Mondal Debasish , Phopase Jaywant , Sadhu Veera , Tamás Éva , Polisetti Naresh , Richter‐Dahlfors Agneta , Liedberg Bo , Griffith May
Published: March 2014

The myocardium is unable to regenerate itself after infarct, resulting in scarring and thinning of the heart wall. Our objective was to develop a patch to buttress and bypass the scarred area, while allowing regeneration by incorporated cardiac stem/progenitor cells (CPCs). Polycaprolactone (PCL) was fabricated as both sheets by solvent casting, and fibrous meshes by electrospinning, as potential patches, to determine the role of topology in proliferation and phenotypic changes to the CPCs. Thiophene‐conjugated carbon nanotubes (T‐CNTs) were incorporated to enhance the mechanical strength. We showed that freshly isolated CPCs from murine hearts neither attached nor spread on the PCL sheets, both with and without T‐CNT. As electrospun meshes, however, both PCL and PCL/T‐CNT supported CPC adhesion, proliferation, and differentiation. The incorporation of T‐CNT into PCL resulted in a significant increase in mechanical strength but no morphological changes to the meshes. In turn, proliferation, but not differentiation, of CPCs into cardiomyocytes was enhanced in T‐CNT containing meshes. We have shown that changing the topology of PCL, a known hydrophobic material, dramatically altered its properties, in this case, allowing CPCs to survive and differentiate. With further development, PCL/T‐CNT meshes or similar patches may become a viable strategy to aid restoration of the postmyocardial infarction myocardium. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B, 102B: 1553–1561, 2014.
A new perspective of shape recognition to discover the phase transition of finite‐size clusters
Authors: Hsu Po‐Jen
Published: March 2014

An ultrafast shape‐recognition technique was used to analyze the phase transition of finite‐size clusters, which, according to our research, has not yet been accomplished. The shape of clusters is the unique property that distinguishes clusters from bulk systems and is comprehensive and natural for structural analysis. In this study, an isothermal molecular dynamics simulation was performed to generate a structural database for shape recognition of AgCu metallic clusters using empirical many‐body potential. The probability contour of the shape similarity exhibits the characteristics of both the specific heat and Lindemann index (bond‐length fluctuation) of clusters. Moreover, our implementation of the substructure to the probability of shapes provides a detailed observation of the atom/shell‐resolved analysis, and the behaviors of the clusters were reconstructed based on the statistical information. The method is efficient, flexible, and applicable in any type of finite‐size system, including polymers and nanostructures. © 2014 Wiley Periodicals, Inc.
Morphological changes produced by acid dissolution in Er:YAG laser irradiated dental enamel
Authors: Manuela Díaz‐Monroy Jennifer , Contreras‐Bulnes Rosalía , Fernando Olea‐Mejía Oscar , Emma Rodríguez‐Vilchis Laura , SÁnchez‐Flores Ignacio
Published: March 2014

Several scientific reports have shown the effects of Er:YAG laser irradiation on enamel morphology. However, there is lack of information regarding the morphological alterations produced by the acid attack on the irradiated surfaces. The aim of this study was to evaluate the morphological changes produced by acid dissolution in Er:YAG laser irradiated dental enamel. Forty‐eight enamel samples were divided into four groups (n = 12). GI (control); Groups II, III, and IV were irradiated with Er:YAG at 100 mJ (12.7 J/cm2), 200 mJ (25.5 J/cm2), and 300 mJ (38.2 J/cm2), respectively, at 10 Hz without water irrigation. Enamel morphology was evaluated before‐irradiation, after‐irradiation, and after‐acid dissolution, by scanning electron microscopy (SEM). Sample coating was avoided and SEM analysis was performed in a low‐vacuum mode. To facilitate the location of the assessment area, a reference point was marked. Morphological changes produced by acid dissolution of irradiated enamel were observed, specifically on laser‐induced undesired effects. These morphological changes were from mild to severe, depending on the presence of after‐irradiation undesired effects. Microsc. Res. Tech. 77:410–414, 2014. © 2014 Wiley Periodicals, Inc.
Investigation of the Ti/Al/Pt/Au and Ti/Au contact materials on the N‐face surface of oxygen doped GaN
Authors: Tsai Chia‐Lung , Fu Yi‐Keng , Chen Hung‐Tse , Chou Chin‐Hsueh , Xuan Rong
Published: March 2014

Ti/Al/Pt/Au and Ti/Au ohmic contact materials on the N‐face surface of oxygen doped GaN (GaN:O) were investigated by measuring the specific contact resistivity (ρc) with respect to annealing temperature. Ti/Au contact showed good ohmic property in contrast to Ti/Al/Pt/Au contact on the N‐face surface of GaN:O. Based on the x‐ray photoelectron spectroscopy results, we found that the formation of N‐Al bonds with the increase of annealing treatment temperature and the increase of upward band bending near the N‐face GaN:O surface might lead to an increase in the effective Schottky barrier high, resulting in an increase in the ρc of N‐face GaN:O. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tunable thermal quenching of photoluminescence in GaN
Authors: Reshchikov M. A. , McNamara J. D. , Shahedipour‐Sandvik F.
Published: March 2014

In this work, we report the observation of abrupt and tunable thermal quenching of photoluminescence (PL) in high‐resistivity, undoped GaN. The ultraviolet luminescence (UVL) band in these samples exhibited abrupt and tunable quenching, which is similar to behavior observed for p ‐type GaN:Mg samples. Such behavior has never been observed for undoped GaN and was very rarely reported for other semiconductors. We describe the effect of temperature and excitation intensity on PL in undoped GaN with a phenomenological model involving three defect species. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Static and transient characteristics of GaN power HFETs with low‐conducting coating
Authors: Gaevski Mikhail , Deng Jianyu , Dobrinsky Alexander , Gaska Remigijus , Shur Michael , Simin Grigory
Published: March 2014

We report on a design of GaN based HFET with a low‐conducting layer (LCL) coating. The LCL coating dramatically improves the electric field uniformity and increases the breakdown voltage. A major advantage is consistent control of the breakdown characteristics, which is expected to dramatically improve yield and reliability. Initial experimental studies demonstrated a three‐fold increase in the breakdown voltage compared with conventional HFETs. The LCL also leads to a much more uniform underlying channel depletion evidenced by a significantly lower HFET channel capacitance in the off state for the HFET based RF switches. This results in a lower loss and higher isolation. Another advantage is a faster transient enabled by LCL, which should improve efficiency and reduce loss for power HFET switches.(© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Heteroepitaxial growth of non‐polar ZnO films on single crystal NdGaO3 (001) substrates by MOCVD
Authors: Kashiwaba Yasuhiro , Yokoyama Tai , Sakuma Mio , Abe Takami , Nakagawa Akira , Niikura Ikuo , Kashiwaba Yasube , Daibo Masahiro , Osada Hiroshi
Published: March 2014

High‐quality non‐polar ZnO (11$ \bar 2 $0) films were epitaxially grown on single crystal NdGaO3 (NGO) (001) substrates. The non‐polar ZnO (11$ \bar 2 $0) films were grown by metal organic chemical vapour deposition using Zn(C5H7O2)2 and O2 gas as starting materials. X‐ray diffraction (XRD) peaks of ZnO (11$ \bar 2 $0) plane were observed in XRD patterns of 2θ‐ω scans in all films. Rotation domains were not found in XRD φ scan patterns of ZnO (11$ \bar 2 $0) films grown at a substrate temperature of 650 °C or less. XRD peaks of NGO (021) and ZnO (11$ \bar 2 $2) planes were observed at the same angle φ in the XRD φ scan patterns. The epitaxial relationship was ZnO (11$ \bar 2 $0)// NGO (001) and ZnO [0001] // NGO [010]. Lattice mismatch values along the ZnO [0001] direction and along the ZnO (1$ \bar 1 $00) direction were 5.36% and –3.70%, respectively. Growth rate was drastically decreased at the substrate temperature over 650 °C. Striped patterns along the ZnO [0001] direction were observed in atomic force microscopy images of ZnO (11$ \bar 2 $0) films grown at substrate temperatures of 600 and 650 °C. Emissions due to donor‐bound excitions were observed in photoluminescence spectra of ZnO (11$ \bar 2 $0) films measured at 10 K. It is thought that NGO (001) substrates are useful for growth of high‐quality non‐polar ZnO (11$ \bar 2 $0) films. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Time‐of‐flight measurements on Schottky CdTe nuclear detectors
Authors: Suzuki Kazuhiko , Ichinohe Yoshihiro , Sawada Takayuki , Imai Kazuaki , Seto Satoru
Published: March 2014

Temporal evolution of the time‐of‐flight current waveforms of Schottky CdTe nuclear detectors as a function of the DC bias duration has been measured at several different temperatures from 278 K to 315 K to investigate the nature of the defects responsible for the polarization phenomena. Three relaxation processes with time constants from less than a second to as long as about a thousand seconds at room temperature are involved in the evolution. Based on the observed temperature dependence, we have concluded that two out of three relaxation processes are attributed to the ionization of defects at 0.54 eV and 0.6 eV. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)