bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimized protocol for the isolation of spleen‐resident murine neutrophils
Authors: Coquery Christine M. , Loo William , Buszko Maja , Lannigan Joanne , Erickson Loren D. 
Published: July 2012

AbstractNeutrophils are an important cellular component of the innate immune system that provides immediate protection to the host from infection. Neutrophil infiltration into inflamed peripheral tissues during infection is beneficial for immunity through phagocytosis of microbes, the release of antimicrobial factors, and secretion of proinflammatory cytokines. Recent reports further suggest that spleen‐infiltrating neutrophils play a role in the adaptive immune response by providing survival signals to B cells. However, neutrophils may have detrimental effects on immunity in inflammatory diseases where their recruitment to lymphoid tissues and activation occur abnormally. To determine the contribution of neutrophils that reside in secondary lymphoid tissues to adaptive immunity, direct evaluation of the functional properties of tissue‐resident neutrophils is required. We have developed a modified magnetic bead isolation approach for purifying neutrophils from inflamed spleens of autoimmune‐prone mice by negative selection. Using this approach, we yielded neutrophils with greater than 90% purity without compromising cell viability. Equally important, the isolation procedure had little effect on the activation of neutrophils and did not impair phagocytic function. Thus, isolation of spleen‐resident neutrophils by this optimized approach could be useful for interrogating the functional role of murine neutrophils in normal and abnormal immune responses. © 2012 International Society for Advancement of Cytometry
A smart handover prediction system based on curve fitting model for Fast Mobile IPv6 in wireless networks
Authors: Sadiq Ali Safa , Bakar Kamalrulnizam Abu , Ghafoor Kayhan Zrar , Lloret Jaime , Mirjalili SeyedAli 
Published: July 2012

SUMMARYSeamless handover process is essential in order to provide efficient communication between mobile nodes in wireless local area networks. Despite the importance of a signal strength prediction model to provide seamless handovers, it is not embedded in standard mobility management protocols. In this article, we propose a smart handover prediction system based on curve fitting model to perform the handover (CHP) algorithm. The received signal strength indicator parameter, from scanning phase, is considered as an input to the CHP in order to provide a prediction technique for a mobile node to estimate the received signal strength value for the access points in the neighborhood and to select the best candidate access point from them in an intelligent way. We implemented the proposed approach and compared it with standard protocols and linear regression‐based handover prediction approach. Simulation results in complex wireless environments show that our CHP approach performs the best by predicting the received signal strength value with up to 800 ms in advance from real obtained value via scanning phase. Moreover, our CHP approach is the best in terms of layer 2 and overall handover latency, in comparison with standard protocols and linear regression approach, respectively. Copyright © 2012 John Wiley & Sons, Ltd.
A hybrid joint ML technique for CFO, timing offset, and channel estimations in an OFDMA uplink
Authors: Thafasal Ijyas V.P. , Sameer S.M. 
Published: July 2012

SUMMARYIn this paper, we propose a novel hybrid joint maximum‐likelihood estimator for carrier frequency offset (CFO), timing offset, and channel response of all users in the uplink of an orthogonal frequency division multiple access (OFDMA) system. The proposed estimation method significantly reduces complexity of this multiparameter, multidimensional optimization problem, using the concept of separation of the different user signals by means of newly defined projection operators. This projection technique is combined with the alternating projection method available in the literature to arrive at a new hybrid algorithm that offers significant performance advantages in terms of computational complexity and estimator performance. The joint estimation of the CFOs, timing offsets, and channel coefficients for all active users together at the base station of the OFDMA uplink is a rarely addressed task. The proposed method also offers the flexibility of application to any subcarrier assignment scheme used in OFDMA systems. Extensive simulation studies corroborate the advantages of the new hybrid method for all three estimation requirements in the multiuser OFDMA uplink. Copyright © 2012 John Wiley & Sons, Ltd.
The major histocompatibility complex and autism spectrum disorder
Authors: Needleman Leigh A. , McAllister A. Kimberley 
Published: July 2012

AbstractAutism spectrum disorder (ASD) is a complex disorder that appears to be caused by interactions between genetic changes and environmental insults during early development. A wide range of factors have been linked to the onset of ASD, but recently both genetic associations and environmental factors point to a central role for immune‐related genes and immune responses to environmental stimuli. Specifically, many of the proteins encoded by the major histocompatibility complex (MHC) play a vital role in the formation, refinement, maintenance, and plasticity of the brain. Manipulations of levels of MHC molecules have illustrated how disrupted MHC signaling can significantly alter brain connectivity and function. Thus, an emerging hypothesis in our field is that disruptions in MHC expression in the developing brain caused by mutations and/or immune dysregulation may contribute to the altered brain connectivity and function characteristic of ASD. This review provides an overview of the structure and function of the three classes of MHC molecules in the immune system, healthy brain, and their possible involvement in ASD. © 2012 Wiley Periodicals, Inc. Develop Neurobiol, 2012
Downlink beamforming and resource allocation in multicell MISO‐OFDMA systems
Authors: Hassan Naveed UL , Assaad Mohamad 
Published: July 2012

ABSTRACTWe study the downlink beamforming (DLBF) and resource optimisation problem in multicell multi‐input single‐output orthogonal frequency division multiple access (MISO‐OFDMA) systems. This is a mixed combinatorial, nonlinear and nonconvex optimisation problem. By using uplink downlink duality, we propose an efficient suboptimal algorithm. This algorithm provides beamformers and allocates subcarriers and power to different users in the network with minimum message passing between the transmitting base stations. DLBF and resource optimisation algorithm for single‐cell MISO‐OFDMA systems can be obtained as a special case of the multicell algorithm. Simulation results reveal the performance gains provided by the proposed algorithm. Copyright © 2012 John Wiley & Sons, Ltd.
Calibration of tipping‐bucket flow meters and rain gauges to measure gross rainfall, throughfall, and stemflow applied to data from a Japanese temperate coniferous forest and a Cambodian tropical deciduous forest
Authors: Iida Shin'ichi , Shimizu Takanori , Kabeya Naoki , Nobuhiro Tatsuhiko , Tamai Koji , Shimizu Akira , Ito Eriko , Ohnuki Yasuhiro , Abe Toshio , Tsuboyama Yoshio , Chann Sophal , Keth Nang 
Published: July 2012

AbstractTipping‐bucket flow meter and rain gauge (TBFM/TBRG) are widely used for the measurement of gross rainfall (GR), throughfall (TF), and stemflow (SF) to evaluate the amount of interception loss (I). However, TBFM/TBRG cannot measure the inflow rate during tipping and underestimates the inflow rate. To correct this systematic bias, 33 total calibrations were conducted for five types of TBFM/TBRG in the laboratory. The tipping time increased with the bucket volume, and the underestimation during one tip was higher for TBFM/TBRG of larger capacity. With the use of the scaled actual inflow rate and the actual volume of a single tip from the measured static volume of a single tip when the inflow rate is zero, the common calibration curves were obtained as quadratic equations for each of the five types within an error range of ±3%. We measured GR and TF by using TBRG and TBFM with a resolution of 0.2 mm and measured SF by TBRG with a single‐tip static volume of 15.7 cm3 in a Japanese temperate coniferous forest (TCF) and a Cambodian tropical deciduous forest (TDF). At both sites, the calibration curves needed to be applied to obtain GR, TF, and SF on an event scale with an underestimation degree of less than 3%. Without applying any calibrations, the higher rainfall intensities in TDF caused larger underestimations of GR, TF, and SF and larger overestimations of I compared with results for TCF. On an annual scale, the degree of overestimation of I relative to GR (ΔI/GR) was 1.2% in TCF and 3.5% in TDF, and ΔI/I was at least 10% at both sites. Copyright © 2012 John Wiley & Sons, Ltd.
Identification of novel driver tumor suppressors through functional interrogation of putative passenger mutations in colorectal cancer
Authors: Zhang Lu , Komurov Kakajan , Wright Woodring E. , Shay Jerry W. 
Published: June 2012

AbstractCancer genome sequencing efforts are leading to the identification of genetic mutations in many types of malignancy. However, the majority of these genetic alterations have been considered random passengers that do not directly contribute to tumorigenesis. We have previously conducted a soft agar‐based short hairpin RNA (shRNA) screen within colorectal cancer (CRC) candidate driver genes (CAN‐genes) using a karyotypically diploid hTERT‐ and CDK4‐immortalized human colonic epithelial cell (HCEC) model and discovered that depletion of 65 of the 151 CAN‐genes enhanced anchorage‐independent growth in HCECs with ectopic expression of K‐RasV12 and/or TP53 knockdown. We now constructed an interaction map of the confirmed CAN‐genes with CRC non‐CAN‐genes and screened for functional tumor suppressors. Remarkably, depletion of 15 out of 25 presumed passenger genes that interact with confirmed CAN‐genes (60%) promoted soft agar growth in HCECs with TP53 knockdown compared to only 7 out of 55 (12.5%) of presumed passenger genes that do not interact. We have thus demonstrated a pool of driver mutations among the putative CRC passenger/incidental mutations, establishing the importance of employing biological filters, in addition to bioinformatics, to identify driver mutations.
Inhibition of GTP cyclohydrolase attenuates tumor growth by reducing angiogenesis and M2‐like polarization of tumor associated macrophages
Authors: Pickert Geethanjali , Lim Hee‐Young , Weigert Andreas , Häussler Annett , Myrczek Thekla , Waldner Maximilian , Labocha Sandra , Ferreirós Nerea , Geisslinger Gerd , Lötsch Jörn , Becker Christoph , Brüne Bernhard , Tegeder Irmgard 
Published: June 2012

AbstractGTP cyclohydrolase (GCH1) is the key‐enzyme to produce the essential enzyme cofactor, tetrahydrobiopterin. The byproduct, neopterin is increased in advanced human cancer and used as cancer‐biomarker, suggesting that pathologically increased GCH1 activity may promote tumor growth. We found that inhibition or silencing of GCH1 reduced tumor cell proliferation and survival and the tube formation of human umbilical vein endothelial cells, which upon hypoxia increased GCH1 and endothelial NOS expression, the latter prevented by inhibition of GCH1. In nude mice xenografted with HT29‐Luc colon cancer cells GCH1 inhibition reduced tumor growth and angiogenesis, determined by in vivo luciferase and near‐infrared imaging of newly formed blood vessels. The treatment with the GCH1 inhibitor shifted the phenotype of tumor associated macrophages from the proangiogenic M2 towards M1, accompanied with a shift of plasma chemokine profiles towards tumor‐attacking chemokines including CXCL10 and RANTES. GCH1 expression was increased in mouse AOM/DSS‐induced colon tumors and in high grade human colon and skin cancer and oppositely, the growth of GCH1‐deficient HT29‐Luc tumor cells in mice was strongly reduced. The data suggest that GCH1 inhibition reduces tumor growth by (i) direct killing of tumor cells, (ii) by inhibiting angiogenesis, and (iii) by enhancing the antitumoral immune response.
Polyaniline Doped with Various Inorganic Acids and Polymeric Acids as Platinum Catalyst Support for Methanol Electro‐oxidation
Authors: Kuo Chung‐Wen , Kuo Ping‐Lin , Ho Ko‐Shan , Hsieh Tar‐Hwa , Chen Sin‐Jhih , Wu Tzi‐Yi , Huang Yu‐Chang 
Published: July 2012

AbstractPolyaniline (PANI) is doped with H2SO4, HCl, poly(acrylic acid) (PAA), poly(acrylic acid‐co‐maleic acid) (PAMA), PAA+HCl, and poly(styrenesulfonic acid) (PSS) to obtain PANI‐H2SO4, PANI‐HCl, PANI‐PAA, PANI‐PAMA, PANI‐(PAA+HCl), and PANI‐PSS films, respectively. Ultraviolet‐visible (UV‐Vis) and Fourier transform infrared (FT‐IR) spectroscopy result confirm that PANI is doped with PSS. X‐ray photoelectron spectroscopy (XPS) results indicate that the nitrogen atoms of PANI‐PSS are the most positively charged in these films. Scanning electron microscopy (SEM) images reveal that these films are composed of highly porous nanowires. Platinum (Pt) can be incorporated into PANI‐H2SO4, PANI‐HCl, PANI‐PAA, PANI‐PAMA, PANI‐(PAA+HCl), and PANI‐PSS films via electrochemical deposition to obtain PANI‐H2SO4‐Pt, PANI‐HCl‐Pt, PANI‐PAA‐Pt, PANI‐PAMA‐Pt, PANI‐(PAA+HCl)‐Pt, and PANI‐PSS‐Pt composite electrodes, respectively. Auger electron spectroscopy (AES) results indicate that Pt particles disperse more uniformly into the spatial regions of PANI‐PSS and PANI‐(PAA+HCl) than those of other films. The PANI‐PSS‐Pt electrode provides the most active surface area of Pt in these electrodes. Cyclic voltammetry results and chronoamperometric response measurements show that the activity and stability toward methanol oxidation of the PANI‐PSS‐Pt electrode are the best in these electrodes.
The Astrochemical Observatory: Molecules in the Laboratory and in the Cosmos
Authors: Palazzetti Federico , Maciel Glauciete S. , Lombardi Andrea , Grossi Gaia , Aquilanti Vincenzo 
Published: July 2012

AbstractAstrochemistry is a discipline consolidated recently, although its roots extend back to the dawn of early civilization with the observation and mapping of the sky. The way to the understanding of the common natural laws on earth and in space paved by Galilei's observations by the telescope, has been extended in the last decades, by new technologies such as radioastronomy and space missions. Plenty of new chemistry was surprisingly discovered. Extreme rich information on the chemical “composition” of the universe is being obtained, either from the other planets and satellites in the Solar System, from meteorites and comets, or from the interstellar space. In this article we will present selected topics regarding the chemical structures and reactions being discovered. Particular attention will be devoted to aspects considered as relevant for the prebiotic processes on earth, such as those involving chirality and its role played in the origin and evolution of life.
Accumulation of Miscanthus‐derived carbon in soils in relation to soil depth and duration of land use under commercial farming conditions
Authors: Felten Daniel , Emmerling Christoph 
Published: July 2012

AbstractBioenergy is becoming an important option in Global Change mitigation policy world‐wide. In agriculture, cultivation of energy crops for biodiesel, biogas, or bioethanol production received considerable attention in the past decades. Beyond this, the cultivation of Miscanthus, used as solid fuel for combustion, may lead to an increase in soil organic matter content compared to other agricultural land use, since C‐sequestration potential in soils of Miscanthus crops is high due to, e.g., high amounts of harvest residues. This may indirectly contribute to a reduction of atmospheric CO2 concentration. The objective of the present work was to investigate the development of soil organic carbon and Miscanthus‐derived C contents, as well as to estimate carbon stocks in soils cultivated with Miscanthus using 13C‐natural‐abundance technique. The investigations were carried out in relation to soil depth up to 150 cm in a sequence of 2, 5, and 16 y of cultivation relative to a reference soil cultivated with cereals. Amounts of total organic C (TOC) and Miscanthus‐derived C (Miscanthus‐C) increased with increasing duration of cultivation. For example, TOC increased from 12.8 to 21.3 g C kg–1 after 16 y of cultivation at the depth of 0–15 cm, whereby the portion of Miscanthus‐C reached 5.8 g C kg–1. Also within deeper soil layers down to 60 cm depth a significant enhancement of Miscanthus‐C was detectable even though TOC contents were not significantly enhanced. At soil depth below 60 cm, no significant differences between treatments were found for Miscanthus‐C. Within 16 y of continuous commercial farming, Miscanthus stands accumulated a total of 17.7 Mg C ha–1 derived from Miscanthus residues (C4‐C), which is equivalent to 1.1 Mg C4‐C ha–1 y–1. The annual surplus might function as CO2 credit within a greenhouse‐gas balance. Moreover, the beneficial properties of Miscanthus cultivation combined with a low requirement on fertilization may justify the status of Miscanthus as a sustainable low‐input bioenergy crop.
Type I and Type II mechanisms of antimicrobial photodynamic therapy: An in vitro study on gram‐negative and gram‐positive bacteria
Authors: Huang Liyi , Xuan Yi , Koide Yuichiro , Zhiyentayev Timur , Tanaka Masamitsu , Hamblin Michael R. 
Published: July 2012

AbstractBackground and ObjectivesAntimicrobial photodynamic therapy (APDT) employs a non‐toxic photosensitizer (PS) and visible light, which in the presence of oxygen produce reactive oxygen species (ROS), such as singlet oxygen (1O2, produced via Type II mechanism) and hydroxyl radical (HO., produced via Type I mechanism). This study examined the relative contributions of 1O2 and HO. to APDT killing of Gram‐positive and Gram‐negative bacteria.Study Design/Materials and MethodsFluorescence probes, 3′‐(p‐hydroxyphenyl)‐fluorescein (HPF) and singlet oxygen sensor green reagent (SOSG) were used to determine HO. and 1O2 produced by illumination of two PS: tris‐cationic‐buckminsterfullerene (BB6) and a conjugate between polyethylenimine and chlorin(e6) (PEI–ce6). Dimethylthiourea is a HO. scavenger, while sodium azide (NaN3) is a quencher of 1O2. Both APDT and killing by Fenton reaction (chemical generation of HO.) were carried out on Gram‐positive bacteria (Staphylococcus aureus and Enterococcus faecalis) and Gram‐negative bacteria (Escherichia coli, Proteus mirabilis, and Pseudomonas aeruginosa).ResultsConjugate PEI‐ce6 mainly produced 1O2 (quenched by NaN3), while BB6 produced HO. in addition to 1O2 when NaN3 potentiated probe activation. NaN3 also potentiated HPF activation by Fenton reagent. All bacteria were killed by Fenton reagent but Gram‐positive bacteria needed a higher concentration than Gram‐negatives. NaN3 potentiated Fenton‐mediated killing of all bacteria. The ratio of APDT killing between Gram‐positive and Gram‐negative bacteria was 2 or 4:1 for BB6 and 25:1 for conjugate PEI‐ce6. There was a NaN3 dose‐dependent inhibition of APDT killing using both PEI‐ce6 and BB6 against Gram‐negative bacteria while NaN3 almost failed to inhibit killing of Gram‐positive bacteria.ConclusionAzidyl radicals may be formed from NaN3 and HO.. It may be that Gram‐negative bacteria are more susceptible to HO. while Gram‐positive bacteria are more susceptible to 1O2. The differences in NaN3 inhibition may reflect differences in the extent of PS binding to bacteria (microenvironment) or differences in penetration of NaN3 into cell walls of bacteria. Lasers Surg. Med. 44: 490–499, 2012. © Wiley Periodicals, Inc.
Isothianaphthene‐Based Conjugated Polymers for Organic Photovoltaic Cells
Authors: Long Guankui , Wan Xiangjian , Zhou Jiaoyan , Liu Yongsheng , Li Zhi , He Guangrui , Zhang Mingtao , Hou Yanhui , Chen Yongsheng 
Published: July 2012

AbstractTwo novel copolymers PBDT‐DEAITN and PBDT‐DOAITN containing the same backbone of isothianaphthene (ITN) quinoidal and benzodithiophene (BDT) donor units are synthesized and their organic photovoltaic (OPV) devices are fabricated. Although these two polymers have rather low optical bandgaps, 1.52 and 1.58 eV for PBDT‐DEAITN and PBDT‐DOAITN, respectively, their OPV cells exhibit rather limited power conversion efficiencies of 1.25% and 1.20% under an AM1.5G simulated solar light. The reasons for the low OPV performance are investigated by structure modeling calculation. Based on this and the screening results for the representative quinoidal polymers in the literatures, a strategy of designing high‐ performance planar polymers based on ITN unit is proposed.
Fractional Crystallization and Phase Segregation in Binary Miscible Poly(butylene succinate)/Poly(ethylene oxide) Crystalline Blends: Effect of Crystallization Temperature
Authors: Pan Pengju , Zhao Li , Yang Jinjun , Inoue Yoshio 
Published: July 2012

AbstractThe effects of crystallization temperature of PBS (TIC,PBS) on the fractional crystallization, phase segregation, and crystalline morphology of PEO in their miscible crystalline/crystalline blends are investigated. The crystallization kinetics and phase segregation of PEO are considerably influenced by TIC,PBS. A higher TIC,PBS results in the crystallization of PEO at an extremely large degree of supercooling and may facilitate the segregation of PEO within the interlamellar regions of PBS. At a high TIC,PBS (e.g., 95 °C), the long period, thickness of amorphous and crystalline layers of PBS increase upon blending with PEO. The TIC,PBS dependence of phase segregation of the PEO component is discussed from a thermodynamic as well as a kinetic perspective.magnified image
Living Polymerization of N‐Substituted β‐Alanine N‐Carboxyanhydrides: Kinetic Investigations and Preparation of an Amphiphilic Block Copoly‐β‐Peptoid
Authors: Grossmann Arlett , Luxenhofer Robert 
Published: July 2012

AbstractPoly(α‐peptoid)s (N‐substituted polyglycines) are interesting peptidomimetic biomaterials that have been discussed for many applications. Poly(β‐peptoid)s (N‐substituted poly‐β‐alanines), although equally intriguing, have received much less attention. Here we present results that suggest that while N‐substituted β‐alanine N‐carboxyanhydrides can undergo a living nucleophilic ring‐opening polymerization, the solubility of poly(β‐peptoid)s can be very poor, which contributes to the limited accessibility using other synthetic approaches. The living character of the polymerization was utilized for the preparation of the first polymerized amphiphilic block copoly‐β‐peptoid. Our results may open a new route towards highly defined functional poly(β‐peptoid)s which could represent biomaterials.