bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Role of Charge Localization in Current‐Driven Dynamics
Authors: Jorn Ryan , Livshits Ester , Baer Roi , Seideman Tamar 
Published: December 2008

AbstractWe explore the role of charge localization in current‐triggered, resonance‐mediated, dynamical events in molecular junctions. To that end we use a simple model for a molecular rattle, a Li+C9H−9 zwitterion attached between two metal clusters. By varying the size of the metal clusters we systematically vary the degree of delocalization of the electronic orbitals underlying the resonant current, and thus can draw general conclusions regarding the effect of delocalization on dynamical processes induced by resonance inelastic current in molecular electronics.In the small cluster limit, we find interesting quantum dynamics in the nuclear subspace, corresponding to coherent tunneling of the wave packet through the barrier of an asymmetric double‐well potential. These dynamics are rapidly damped with increasing charge delocalization in extended systems.
Neural Progenitors of the Postnatal and Adult Mouse Forebrain Retain the Ability to Self-Replicate, Form Neurospheres, and Undergo Multipotent Differentiation In Vivo
Authors: Neumeister Bettina , Grabosch Antje , Basak Onur , Kemler Rolf , Taylor Verdon 
Published: December 2008

Abstract
Somatic stem cells are reservoirs to replace lost cells or damaged tissue. Cells with neural stem cell (NSC) characteristics can be isolated from the postnatal mammalian brain into adulthood and expanded as neurospheres. We addressed the ability of these in vitro expanded putative NSCs to retain progenitor characteristics in vivo, in analogy to hematopoietic stem cells. When transplanted in utero, both postnatal and adult neural progenitors colonize host brains and contribute neurons and glia. In stark contrast to what has been reported when transplanted in postnatal hosts, epidermal growth factor-expanded cells also remain self-replicating and multipotent in vivo over many months and can be serially transplanted into multiple hosts. Surprisingly, embryonically transplanted NSCs remain in the neurogenic regions in adult hosts, where they express progenitor cell markers and continue to proliferate even after 6 months without tumor formation. These data indicate that spherogenic cells of the postnatal and adult mammalian brain retain their potential in vitro and in vivo throughout the life of the organism and beyond transplantation, which has important implications for cell replacement strategies.
Induced Pluripotent Stem Cell Generation Using a Single Lentiviral Stem Cell Cassette
Authors: Sommer Cesar A. , Stadtfeld Matthias , Murphy George J. , Hochedlinger Konrad , Kotton Darrell N. , Mostoslavsky Gustavo 
Published: December 2008

Abstract
Induced pluripotent stem (iPS) cells can be generated using retroviral vectors expressing Oct4, Klf4, Sox2, and cMyc. Most prior studies have required multiple retroviral vectors for reprogramming, resulting in high numbers of genomic integrations in iPS cells and limiting their use for therapeutic applications. Here we describe the use of a single lentiviral vector expressing a “stem cell cassette” composed of the four transcription factors and a combination of 2A peptide and internal ribosome entry site technology, generating iPS cells from postnatal fibroblasts. iPS cells generated in this manner display embryonic stem cell-like morphology, express stem cell markers, and exhibit in vivo pluripotency, as evidenced by their ability to differentiate in teratoma assays and their robust contribution to mouse chimeras. Combining all factors into a single transcript achieves the most efficient reprogramming system to date and allows derivation of iPS cells with a single viral integration. The use of a single lentiviral vector for reprogramming represents a powerful laboratory tool and a significant step toward the application of iPS technology for clinical purposes.
Relationship Between Cerebrospinal Fluid Visfatin (PBEF/Nampt) Levels and Adiposity in Humans
Authors: Hallschmid Manfred , Randeva Harpal , Tan Bee K. , Kern Werner , Lehnert Hendrik 
Published: December 2008

OBJECTIVE—Observations of elevated circulating concentrations of visfatin (PBEF/Nampt) in obesity and diabetes suggest that this recently described adipokine is involved in the regulation of body weight and metabolism. We examined in humans whether visfatin is found in cerebrospinal fluid (CSF) and, if so, how CSF visfatin concentrations relate to adiposity and metabolic parameters.
RESEARCH DESIGN AND METHODS—We measured visfatin concentrations in the plasma and CSF of 38 subjects (18 men and 20 women; age 19–80 years) with a wide range of body weight (BMI 16.24–38.10 kg/m2). In addition, anthropometric parameters and endocrine markers were assessed. Bivariate correlation coefficients were determined and stepwise multiple regression analyses were performed to detect associations of CSF and plasma visfatin levels with relevant parameters.
RESULTS—Plasma visfatin levels increased with rising BMI (P &lt; 0.0001) and body fat mass (P &lt; 0.0001). In contrast, CSF visfatin levels decreased with increasing plasma visfatin concentrations (P &lt; 0.03), BMI (P &lt; 0.001), body fat mass (P &lt; 0.0001), and insulin resistance (P &lt; 0.05). Body fat was the only factor independently associated with CSF visfatin, explaining 58% of the variation of CSF visfatin levels (P &lt; 0.0001). Neither plasma (P &gt; 0.13) nor CSF (P &gt; 0.61) visfatin concentrations differed between men and women.
CONCLUSIONS—Our data indicate that visfatin concentrations in human CSF decrease with rising body fat, supporting the assumption that visfatin transport across the blood-brain barrier is impaired in obesity and that central nervous visfatin insufficiency or resistance are linked to pathogenetic mechanisms of obesity.
Seed coat and fruit surface micromorphology of some <i>Cynoglossum</i> L. (Boraginaceae) species
Authors: Akcin Oznur Ergen 
Published: December 2008

Fruits and seeds of Cynoglossum creticum Miller, C. officinale L., C. montanum L. and C. glochidiatum Wallich) distributed in the Middle and East Black Sea Region in Turkey were studied by scanning electron microscopy. Some differences were found in seed coats and fruit surfaces. SEM observations of fruit surface were focused on surface ornamentation and glochids. Two types (tuberculate and granulate) and two subtypes (granulate - punctuate and granulate - tuberculate) were observed among the species. Reticulate type of seed coat and detailed subtypes of reticulate types were determined on the basis of ornamentation of the seed coats. Â Â Â Key words: Cynoglossum, Fruit surface, Seedcoat, SEM, Micromorphology, Boraginaceae doi:10.3329/bjb.v37i2.1716 Bangladesh J. Bot. 37(2): 115-119, 2008 (December)
Quantification and nitrogen fixation of cyanobacteria in rice field soils of Bangladesh
Authors: Begum ZN Tahmida , Mandal R , Amin Farzana Binta 
Published: December 2008

Quantification of cyanobacterial population and nitrogen fixation of 18 heterocystous cyanobacteria isolated from rice fields soils of 11 districts of Bangladesh have been studied. The taxa recorded were, namely Nostoc linckia, N. carneum, N. ellipsosporum, N. piscinale, Anabaena oryzae, Scytonema mirabile, Calothrix marchica and Hapalosiphon welwetschii. The number of cyanobacterial population varied significantly ranging from 14.6 × 104 to 141.0 × 104/g soil. N2-fixation of Nostoc linckia isolated from rice fields of Dhaka and Brahmanbaria ranged from 1.84 to 8.13 mg N 50/ml. However, the potentiality of other species was more or less similar. Single correlation study suggests that quantitative variation in cyanobacterial population was significantly related positively to soil reaction, available P and available S and negatively to total N content of soil. However, multiple correlations reflects that variation of cyanobacterial population was due to cumulative contribution of all the variables. Key words: Cyanobacteria, Quantification, N2-fixation, Rice field soil doi:10.3329/bjb.v37i2.1728 Bangladesh J. Bot. 37(2): 183-188, 2008 (December)
Cytological effect of virus infection in five crop species
Authors: Naz Atika , Kabir G , Ud-Deen MM 
Published: December 2008

Meiotic abnormalities and pollen sterility due to virus infection in Capsicum annuum L., Carica papaya L., Lablab purpureus L., Lycopersicon esculentum L., and Solanum melongena L. were studied. Comparison in with unaffected plants showed that virus infected plants, asynapsis, multivalents and lower chiasma frequencies were present. Frequencies of chromosomal irregularities and pollen sterility were high in virus infected plants. Â Key words: Virus infection, Cytological effect, Plant species doi:10.3329/bjb.v37i2.1734 Bangladesh J. Bot. 37(2): 207-209, 2008 (December)
Symmetric Versus Unsymmetric Platinum(II) Bis(aryleneethynylene)s with Distinct Electronic Structures for Optical Power Limiting/Optical Transparency Trade‐off Optimization
Authors: Zhou Guijiang , Wong Wai‐Yeung , Poon Suk‐Yue , Ye Cheng , Lin Zhenyang 
Published: December 2008

AbstractA new series of symmetric and unsymmetric Pt(II) bis(acetylide) complexes of the type DC≡CPt(PBu3)2C≡CD (DPtD), AC≡CPt(PBu3)2C≡CA (APtA) and DC≡CPt(PBu3)2C≡CA (DPtA) (D, donor groups; A, acceptor groups) are synthesized, and show superior optical power limiting (OPL)/optical transparency trade‐offs. By tailoring the electronic properties of the aryleneethynylene group, distinct electronic structures for these metalated complexes can be obtained, which significantly affect their photophysical behavior and OPL properties for a nanosecond laser pulse at 532 nm. Electronic influence of the ligand type and the molecular symmetry of metal group on the optical transparency/nonlinearity optimization is thoroughly elucidated. Generally, aryleneethynylene ligands with π electron‐accepting nature will effectively enhance the harvesting efficiency of the triplet excited states. The ligand variation to the OPL strength of these Pt(II) compounds follows the order: DPtD > DPtA > APtA. These results could be attributed to the distinctive excited state character induced by their different electronic structures, on the basis of the data from both photophysical studies and theoretical calculations. All of the complexes show very good optical transparencies in the visible‐light region and exhibit excellent OPL responses with very impressive figure of merit σex/σo values (up to 17), which remarkably outweigh those of state‐of‐the‐art reverse saturable absorption dyes such as C60 and metallophthalocyanines with very poor transparencies. Their lower optical‐limiting thresholds (0.05 J cm−2 at 92% linear transmittance) compared with that of the best materials (ca. 0.07 J cm−2 for InPc and PbPc dyes) currently in use will render these highly transparent materials promising candidates for practical OPL devices for the protection of human eyes and other delicate electro‐optic sensors.
Conjugated Polyelectrolytes as Light‐Up Macromolecular Probes for Heparin Sensing
Authors: Pu Kan‐Yi , Liu Bin 
Published: December 2008

AbstractTwo cationic poly(fluorene‐alt‐benzothiadiazole)s with different side chains are designed and synthesized. Both polymers show low fluorescence in aqueous solution due to the charge‐transfer character of the polymer's excited states. Fluorescence turn‐on biosensors for heparin detection and quantification are developed, taking advantage of complexation‐induced aggregation, which increases the polymer fluorescence in aqueous solution. It is found that good polymer water‐solubility is beneficial to the sensitivity and fluorescence contrast of the heparin turn‐on sensor as a result of the low fluorescence background. Moreover, stronger complexation between the polymer/heparin leads to a substantially larger fluorescence increase in the presence of heparin relative to that in the presence of its analog, hyaluronic acid (HA), allowing discrimination of heparin from HA. Heparin quantification with a practical calibration range covering the whole therapeutic dosing levels (0.2–8 U mL−1) is realized based on the polymer with good water‐solubility. This investigation provides a new insight for designing conjugated polymers with a light‐up signature for biomolecular sensing.
Transparent Photo‐Stable Complementary Inverter with an Organic/Inorganic Nanohybrid Dielectric Layer
Authors: Oh Min Suk , Lee Kimoon , Lee Kwang H. , Cha Sung Hoon , Choi Jeong Min , Lee Byoung H. , Sung Myung M. , Im Seongil 
Published: December 2008

AbstractTransparent electronics has been one of the key terminologies forecasting the ubiquitous technology era. Several researchers have thus extensively developed transparent oxide‐based thin‐film transistors (TFTs) on glass and plastic substrates. However, work in transparent electronics has been limited mostly to high‐voltage devices operating at more than a few tens of volts, and has mainly focused on transparent display drivers. Low‐voltage logic devices, such as transparent complementary inverters, operating in an electrically stable and photo‐stable manner, are now very necessary to practically realize transparent electronics. Electrically stable dielectrics with high strength and high capacitance must also be proposed to support this mission, and simultaneously these dielectrics must be compatible with both n‐ and p‐channel TFTs in device fabrication. Here, a nanohybrid dielectric layer that is composed of multiple units of inorganic oxide and organic self‐assembled monolayer is proposel to support a transparent complementary TFT inverter operating at 3 V.
Metal Ion Implantation for the Fabrication of Stretchable Electrodes on Elastomers
Authors: Rosset Samuel , Niklaus Muhamed , Dubois Philippe , Shea Herbert R. 
Published: December 2008

AbstractHere, the use of low‐energy metal ion implantation by filtered cathodic vacuum arc to create highly deformable electrodes on polydimethylsiloxane (PDMS) membranes is reported. Implantation leads to the creation of nanometer‐size clusters in the first 50 nm below the surface. When the elastomer is stretched, these small clusters can move relative to one another, maintaining electrical conduction at strains of up to 175%. Sheet resistance versus ion dose, resistance versus strain, time stability of the resistance, and the impact of implantation on the elastomer's Young's modulus are investigated for gold, palladium, and titanium implantations. Of the three tested metals, gold has the best performance, combining low and stable surface resistance, very high strain capabilities before loss of electrical conduction, and low impact on the Young's modulus of the PDMS membrane. These electrodes are cyclically strained to 30% for more than 105cycles and remain conductive. In contrast, sputtered or evaporate metals films cease to conduct at strains of order 3%. Additionally, metal ion implantation allows for creating semi‐transparent electrodes. The optical transmission through 25‐µm‐thick PDMS membranes decreases from 90% to 60% for Pd implantations at doses used to make stretchable electrodes. The implantation technique presented here allows the rapid production of reliable stretchable electrodes for a number of applications, including dielectric elastomer actuators and foldable or rollable electronics.
Global phase behavior of imidazolium ionic liquids and compressed 1,1,1,2‐tetrafluoroethane (R‐134a)
Authors: Ren Wei , Scurto Aaron M. 
Published: December 2008

AbstractNovel processes involving ionic liquids with refrigerant gases have recently been developed. Here, the complete global phase behavior has been measured for the refrigerant gas, 1,1,1,2‐tetrafluoroethane (R‐134a) and 1‐n‐alkyl‐3‐methyl‐imidazolium ionic liquids with the anions hexafluorophosphate [PF6], tetrafluoroborate [BF4] and bis(trifluoromethylsulfonyl)imide [Tf2N] from ∼0°C to 105°C and to 33 MPa. All of the systems studied were Type V from the classification scheme of Scott‐van Konynenburg with regions of vapor‐liquid equilibrium, miscible/critical regions, vapor‐liquid‐liquid equilibrium, and upper and lower critical endpoints (UCEP and LCEP). The effect of the alkyl chain length has been investigated, for ethyl‐([EMIm]), n‐butyl‐([BMIm]), and n‐hexyl‐([HMIm]). With increasing chain length, the temperature of the lower critical end points increases and pressure at the mixture critical points decrease. With a common cation, the temperature of the LCEP increased and the mixture critical point pressures decreased in the order of [BF4], [PF6], and [Tf2N]. © 2008 American Institute of Chemical Engineers AIChE J, 2009
Post‐last glacial maximum expansion from Iberia to North Africa revealed by fine characterization of mtDNA H haplogroup in Tunisia
Authors: Cherni Lotfi , Fernandes Verónica , Pereira Joana B. , Costa Marta D. , Goios Ana , Frigi Sabeh , Yacoubi‐Loueslati Besma , Amor Mohamed Ben , Slama Abdelhakim , Amorim António , El Gaaied Amel Ben Ammar , Pereira Luísa 
Published: December 2008

AbstractThe first large‐scale fine characterization of Tunisian H lineages clarifies that the post‐Last glacial maximum expansion originating in Iberia not only led to the resettlement of Europe but also of North Africa. We found that 46% of 81 Tunisian H lineages subscreened for 1,580 bp in mtDNA coding region were affiliated with H1 and H3 subhaplogroups, which are known to have originated in Iberia. Although no signs of local expansion were detected, which would allow a clear dating of their introduction, the younger and less diverse Tunisian H1 and H3 lineages indicate Iberia as the radiating centre. Major contributions from historical migrations to this Iberian genetic imprint in Tunisia were ruled out by the mtDNA gene pool similarity between Berber/Arab/cosmopolitan samples and some “Andalusian” communities, settled by the descendents of the “Moors” who once lived in Iberia for 10 centuries (between 8th and 17th centuries), before being expelled to Tunisia. Am J Phys Anthropol, 2009. © 2008 Wiley‐Liss, Inc.
Solid‐state graft polymerization of styrene in spherical polypropylene granules in the presence of TEMPO
Authors: Sun Fangli , Fu Zhisheng , Deng Qingtian , Fan Zhiqiang 
Published: December 2008

AbstractA series of polypropylene‐graft‐polystyrene (PP‐g‐PS) were prepared by solid‐state graft polymerization of styrene (St) in the presence of tert‐butyl perbenzoate (TBPB) and 2,2,6,6‐tetramethyl‐piperidinyloxy (TEMPO) using nascent spherical isotactic polypropylene (PP) granules as matrix. Reaction conditions such as ratio of TEMPO to TBPB, amount of TBPB and St, reaction time and temperature were investigated. The grafting degree (GD) decreased slightly with the addition of TEMPO, but the introduction of TEMPO reduced gel formation and degradation of PP chain. Introduction of camphor sulfonic acid in the TEMPO‐mediated grafting polymerization system lead to evident increase in molecular weight of PP‐g‐PS and decrease of gel formation with slight changes of GD. GPC curves of the product synthesized with TEMPO addition showed obvious tailing at high molecular weight end. Complex viscosity in dependence on angular frequency of the melt of product showed obvious shear‐thinning behaviors. All the experimental results indicated existence of long‐chain branches in the product of graft polymerization. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Unsynchronized Diameter Changes of Double‐Wall Carbon Nanotubes during Chemical Vapour Deposition Growth
Authors: Ning Guoqing , Shinohara Hisanori 
Published: December 2008

AbstractUnsynchronized growing! Unsynchronized diameter changes of the inner and the outer tubes are observed in the double‐wall carbon nanotubes (DWNTs) prepared by CoMo/MgO catalysts. The difference of the growth surroundings for the inner and outer tubes of DWNTs can consistently explain the observed unsynchronized diameter changes.magnified imageNovel structural changes of double‐wall carbon nanotubes (DWNTs) triggered by sudden swings of reaction condition have been elucidated. A quick temperature decrease or increase would lead to a decrease or increase, respectively, in the CH4 decomposition rate and to reformation of catalyst metal particles. In particular, unsynchronized diameter changes of the inner and the outer tubes are observed in the DWNTs prepared by CoMo/MgO catalysts. We have found that the difference of the growth surroundings for the inner and outer tubes of DWNTs can consistently explain the observed unsynchronized diameter changes.
Retracted: ENSO‐related modulation of coastal upwelling along the central east coast of India
Authors: Muni Krishna K. , Ramalingeswara Rao S. 
Published: December 2008

AbstractAn index of El Niño Southern Oscillation (ENSO) in the Pacific during February through April is shown to account for a significant part of the variability of coastal sea surface temperature (SST) anomalies measured a few months later within the central east coast of India (CEI). This ENSO‐related modulation of coastal upwelling appears to contribute to the connection observed at the basin‐scale between ENSO and SST in the Bay of Bengal. The ability to use this teleconnection to give warning of large changes in the CEI a few months in advance is exemplified using data 1998–1999 ENSO events. Copyright © 2008 Royal Meteorological Society
Quantitative determination of oLAb titers in various animal species
Authors: Tatzber F. , Wonisch W. , Schmidl E. , Esterbauer H. 
Published: December 2008

AbstractIt is generally accepted, that lipid peroxidation plays a pathogenic role in atherosclerosis. Furthermore, recent studies indicate that antibodies directed against oxidative modifications of Low Density Lipoprotein (oLAb) contribute to atherosclerotic processes and may have some function in other disorders. These antibodies have been determined predominantly in humans, because assays for oLAb measurement use species specific anti IgG conjugates. From such assay designs it is not possible to get directly comparable data from various animal species. Main advantages of comparable data between animal species are that results of animal experiments can be interpreted using human calibrators and that results of immunisations and production of monoclonal antibodies are directly comparable not only within, but also between animal species. The aim of this study was to find a modification for ELISAs for oLAb determination, which allows to measure sera of various animal species simultaneously.Microtitration plates were coated with oxidised LDL and blocked with bovine serum albumine. Human and animal sera were then pipetted into the plate in logarithmic serial dilutions and incubated for 2 h at 37°C. After washing, a protein A horse‐radish peroxidase conjugate (Biomakor, Israel) was added to each well in a dilution of 1:20,000. The incubation conditions had to be optimized to achieve reliable results. After another washing step, the assay was developed with TMB. Absorptions were read at 450 nm in a microplate photometer.Following the manufacturers incubation instructions, which recommended a duration of 1 h at room temperature, the system did not work optimally. No binding of protein A to IgG molecules bound to oxidised LDL could be observed, if the system was incubated at 37°C. In our hands, best results were achieved for several animal species, if the conjugate was incubated for two hours at 2–4°C in a refrigerator. Under these conditions, assay sensitivity was the same as in the standard method, which uses anti‐species IgG conjugates.The protein A modification of oLAb allows direct reading of animal oLAb titres from human calibrators. With this method, results of animal experiments can be interpreted on the basis of the situation in humans. Preliminary results obtained show that immunisation experiments with oxidised LDL give serum titres in animals, which are in the same order of magnitude as human sera with high oLAb concentrations. The results of this study, in accordance with findings of other authors, give further indications that atherosclerotic processes are influenced by the specific immune system.