bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Multifunctional Iridium‐Carbazolyl Orange Phosphor for High‐Performance Two‐Element WOLED Exploiting Exciton‐Managed Fluorescence/Phosphorescence
Authors: Ho Cheuk‐Lam , Wong Wai‐Yeung , Wang Qi , Ma Dongge , Wang Lixiang , Lin Zhenyang 
Published: March 2008

AbstractBy attaching a bulky, inductively electron‐withdrawing trifluoromethyl (CF3) group on the pyridyl ring of the rigid 2‐[3‐ (N‐phenylcarbazolyl)]pyridine cyclometalated ligand, we successfully synthesized a new heteroleptic orange‐emitting phosphorescent iridium(III) complex [Ir(L1)2(acac)] 1 (HL1 = 5‐trifluoromethyl‐2‐[3‐(N‐phenylcarbazolyl)]pyridine, Hacac = acetylacetone) in good yield. The structural and electronic properties of 1 were examined by X‐ray crystallography and time‐dependent DFT calculations. The influence of CF3 substituents on the optical, electrochemical and electroluminescence (EL) properties of 1 were studied. We note that incorporation of the carbazolyl unit facilitates the hole‐transporting ability of the complex, and more importantly, attachment of CF3 group provides an access to a highly efficient electrophosphor for the fabrication of orange phosphorescent organic light‐emitting diodes (OLEDs) with outstanding device performance. These orange OLEDs can produce a maximum current efficiency of ∼40 cd A−1, corresponding to an external quantum efficiency of ∼12% ph/el (photons per electron) and a power efficiency of ∼24 lm W−1. Remarkably, high‐performance simple two‐element white OLEDs (WOLEDs) with excellent color stability can be fabricated using an orange triplet‐harvesting emitter 1 in conjunction with a blue singlet‐harvesting emitter. By using such a new system where the host singlet is resonant with the blue fluorophore singlet state and the host triplet is resonant with the orange phosphor triplet level, this white light‐emitting structure can achieve peak EL efficiencies of 26.6 cd A−1 and 13.5 lm W−1 that are generally superior to other two‐element all‐fluorophore or all‐phosphor OLED counterparts in terms of both color stability and emission efficiency.
Probing Local Surface Potential of Quasi‐One‐Dimensional Systems: A KPFM Study of P3HT Nanofibers
Authors: Liscio Andrea , Palermo Vincenzo , Samorı` Paolo 
Published: March 2008

AbstractA new model for the quantitative analysis of Kelvin Probe Force Microscopy (KPFM) measurements of quasi‐one‐dimensional systems is presented. It is applied to precisely determine the local surface potential (SP) of semiconducting nanofibers of poly(3‐hexylthiophene) (P3HT) self‐assembled on various flat substrates. To study these quasi‐one dimensional objects, the effective area has been defined. This parameter represents the area of sample surface interacting with the KPFM probe and it plays a crucial role in the estimation of the SP of nanofibers having a cross‐section comparable to the apical diameter of the tip, i.e., 20 nm. Therefore our model makes it possible to gain quantitative insight into nano‐systems smaller than 20 nm. In particular, through the estimation of the effective area, it allows to determine the local surface potential of single nanofiber as well as to simulate the KPFM image of nano‐assemblies adsorbed both on electrically insulating and conducting substrates. This versatile model represents a useful tool to study with a high degree of precision the surface potential characteristics of nanowires paving the way towards their use as building blocks for the fabrication of electronic nanodevices with improved performance.
Cooperative Catalysis in the Hydrolytic Kinetic Resolution of Epoxides by Chiral [(salen)Co(III)] Complexes Immobilized on Gold Colloids
Authors: Belser Thomas , Jacobsen Eric N. 
Published: March 2008

AbstractChiral salen ligands were incorporated into self‐assembled thiolate monolayers (SAMs) on gold colloids. Treatment of the immobilized ligand with Co(OAc)2⋅4 H2O yielded the corresponding [(salen)Co(II)] complex, and aerobic oxidation in the presence of triflic acid afforded the catalytically active [(salen)Co(III)] complex. Functionalized gold colloids with a diameter of 3.4 nm, coated with a mixed monolayer of n‐octanethiolates and thiolates with chiral [(salen)Co(III)] end groups were studied as catalysts in the hydrolytic kinetic resolution (HKR) of hexene‐1‐oxide. Extremely high selectivitiy and significant rate acceleration relative to homogeneous monomeric catalysts were observed. Recovery of the immobilized catalyst was accomplished by simple filtration, and catalyst reoxidation and repeated recycling (seven times) was possible with no loss of reactivity or enantioselectivity.
Technical note: A rapid diagnostic test detects plague in ancient human remains: An example of the interaction between archeological and biological approaches (southeastern France, 16th–18th centuries)
Authors: Bianucci Raffaella , Rahalison Lila , Massa Emma Rabino , Peluso Alberto , Ferroglio Ezio , Signoli Michel 
Published: March 2008

AbstractA rapid diagnostic test (RDT) that detects Yersinia pestis F1 antigen was applied to 28 putative plague victims exhumed from seven burial sites in southeastern France dating to the 16th–18th centuries. Yersinia pestis F1 antigen was detected in 19 of the 28 (67.9%) samples. The 27 samples used as negative controls yielded negative results. Soil samples taken from archeological sites related to both positive and negative samples tested negative for F1 antigen. The detection threshold of the RDT for plague (0.5 ng/ml) is sufficient for a preliminary retrospective diagnosis of Y. pestis infection in human remains. The high specificity and sensitivity of the assay were confirmed. For two sites positive to F1 antigen (Lambesc and Marseille), Y. pestis‐specific DNA (pla gene) had been identified previously by PCR‐sequence based analyses. Specifically, the positive results for two samples, from the Lambesc cemetery and the Marseille pit burial, matched those previously reported using PCR. Independent analyses in Italy and France of different samples taken from the same burial sites (Draguignan and Martigues) led to the identification of both Y. pestis F1 antigen and Y. pestis pla and gplD genes. These data are clear evidence of the presence of Y. pestis in the ancient human remains examined in this study. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
Genetic investigation of the patrilineal kinship structure of early medieval Ireland
Authors: McEvoy Brian , Simms Katharine , Bradley Daniel G. 
Published: March 2008

AbstractA previous study of Irish Y‐chromosomes uncovered a likely patrilineal kinship basis to the most prominent early Irish tribal entity/kingdom, the Uí Néill, who dominated the North of the Island during the early medieval period (600–1,000 AD). However, it is unknown to what extent this was a general feature of the multitude of Irish kingdoms that existed over the same period. Irish surnames are patrilineally inherited in a similar manner to the Y‐chromosome and their origin can often be traced to pre‐existing tribal units. We genotyped 17 microsatellites in 247 Y‐chromosomes from men with surnames that are purported to be derived from two different tribes (Eóganacht and Dál Cais) from the Southern province of Munster, as well as a third cohort of random names from the same geographic area. Although there is some sharing of Y‐chromosomes between surnames of the same putative origin, there was no clear distinction between either grouping and the control, suggesting that the level of Uí Néill patrilineal kinship was not a universal feature of Irish tribal units. In turn this argues that an extensive extended clan or biological legacy of an eponymous founding ancestor was not necessarily a crucial factor in their establishment. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
Septal aperture of the humerus in a mediaeval human skeletal population
Authors: Mays Simon 
Published: March 2008

AbstractHumeral septal aperture is studied in a large Mediaeval skeletal series from England. The aims are to investigate associations between septal aperture and sex, age, side and humeral robusticity; and to evaluate any associations with relative projection of ulna coronoid and olecranon processes. In this way, it is hoped to shed light on age at occurrence and the causation of the trait. Results showed a paucity of cases in juveniles. In adults, the trait was more common in left bones and in females. No association was found with humeral robusticity or humero‐ulnar conformation. Detailed morphological study of humeral septa of individuals with and without apertures suggested that septal aperture forms via resorption from the anterior surface of the septum. In this group, apertures appear generally to form in early adult life. It is suggested that in the study group septal aperture generally arises from impingement on the humeral septum by the coronoid and olecranon processes, chiefly the former. It is tentatively suggested that frequency of septal aperture may be an index of joint hypermobility in earlier populations. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
Mesoporöse Kohlenstoffmaterialien: Synthese und Modifizierung
Authors: Liang Chengdu , Li Zuojiang , Dai Sheng 
Published: March 2008

AbstractIhre große spezifische Oberfläche und ihre physikochemischen Eigenschaften machen poröse Kohlenstoffmaterialien für viele Anwendungen interessant. Die konventionellen Herstellungsmethoden liefern jedoch nur uneinheitlich poröse Materialien, deren Porengrößenverteilungen, ganz zu schweigen von den Mesostrukturen, kaum zu steuern sind. Fortschritte bei anderen mesoporösen Materialien haben auch zur Entwicklung von Verfahren zur Synthese mesoporöser Kohlenstoffmaterialien mit extrem großen spezifischen Oberflächen und geordneten Mesostrukturen geführt, die als potenzielle Katalysatoren, Trennmedien und hochentwickelte elektronische Materialien in vielen Wissenschaftszweigen von Interesse sind. Die derzeit gängigen Synthesemethoden lassen sich in Harttemplat‐ und Weichtemplatmethoden unterteilen. Beide werden in diesem Beitrag gemeinsam mit Verfahren zur Funktionalisierung der Oberflächen der erhaltenen Kohlenstoffmaterialien vorgestellt.
Mesoporous Carbon Materials: Synthesis and Modification
Authors: Liang Chengdu , Li Zuojiang , Dai Sheng 
Published: March 2008

AbstractPorous carbon materials are of interest in many applications because of their high surface area and physicochemical properties. Conventional syntheses can only produce randomly porous materials, with little control over the pore‐size distributions, let alone mesostructures. Recent breakthroughs in the preparation of other porous materials have resulted in the development of methods for the preparation of mesoporous carbon materials with extremely high surface areas and ordered mesostructures, with potential applications as catalysts, separation media, and advanced electronic materials in many scientific disciplines. Current syntheses can be categorized as either hard‐template or soft‐template methods. Both are examined in this Review along with procedures for surface functionalization of the carbon materials obtained.
Processing and properties of modified polyamide 66‐organoclay nanocomposites
Authors: Mert Miray , Yilmazer Ulku 
Published: March 2008

AbstractBinary polyamide 66 nanocomposites containing 2 wt % organoclay, polyamide 66 blend containing 5 wt % impact modifier, and ternary polyamide 66 nanocomposites containing 2 wt % organoclay and 5 wt % impact modifier were prepared by melt compounding method. The effects of E‐GMA and the types of the organoclays on the interaction between the organoclay and the polymer, dispersion of the organoclay, morphology, mechanical, flow, and thermal properties of the nanocomposites were investigated. Partial exfoliation and improved mechanical properties are observed for Cloisite® 15A and Cloisite® 25A nanocomposites. On the other hand, the organoclay was intercalated or in the form of tactoids in Cloisite® 30B nanocomposites. Components of the nanocomposites containing Cloisite® 15A and Cloisite® 25A were compounded in different addition orders. Mixing sequence of the components affected both the dispersion of the organoclay and the mechanical properties drastically. SEM analyses revealed that homogeneous dispersion of the organoclay results in a decrease in the domain sizes and promotes the improvements in the toughness of the materials. Melt viscosity was also found to have a profound effect on the dispersion of the organoclay according to MFI and XRD results. Crystallinity of the nanocomposites did not change significantly. It is only the type of the constituents and their addition order what dramatically influence the nanocomposite properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Simultaneous determination of geniposide and its metabolites genipin and genipinine in culture of Aspergillus niger by HPLC
Authors: Chen Chungang , Han Fenxia , Zhang Yan , Lu Jianfeng , Shi Yuzhong 
Published: March 2008

AbstractWhen cultivated with Aspergillus niger, geniposide, an important drug, is transformed into genipin and genipinine. A simple and rapid HPLC method for simultaneous determination of geniposide and its two metabolites in broth of A. niger is described. The chromatographic separation was achieved on a C18 ODS column (250 × 4.6 mm) by gradient elution with 0.1% formic acid in water and 0.1% formic acid in acetonitrile as the gradient mixtures. The flow rate was 1 mL/min, the detection wavelength was 238 nm and the column temperature was kept at 28°C. The retention times of geniposide, genipin and genipinine were 10.9, 13.8 and 21.5 min, respectively. The mean absolute recoveries of three analysts were over 98%. Quantification limits were 0.01 µg/mL for geniposide and 0.02 µg/mL for the two metabolites. The method was applied for the quantification of geniposide, genipin and genipinine during fermentation and the evaluation of the bioavailabilities of these three compounds in Caco‐2 monolayer. Copyright © 2008 John Wiley & Sons, Ltd.
Determination of plasma topiramate concentration using LC‐MS/MS for pharmacokinetic and bioequivalence studies in healthy Korean volunteers
Authors: Park Jin‐Hee , Park Yoo‐Sin , Lee Min‐Ho , Rhim Si‐Youn , Song Jae‐Chul , Lee Soo‐Jin , Kim Jung‐Mogg , Shaw Leslie M , Kang Ju‐Seop 
Published: March 2008

AbstractA rapid, simple and validated liquid chromatography coupled to tandem mass spectrometric method (LC‐MS/MS) for topiramate analysis in human plasma has been applied to pharmacokinetic and bioequivalence studies in 24 healthy male Korean volunteers. The procedure involves a simple liquid extraction of topiramate and prednisone (internal standard) with acetonitrile and separation by HPLC equipped with a Capcell Pak C18 column using acetonitrile–0.1% triethylamine (80:20, v/v) as a mobile phase. Detection was carried out on an API 2000 MS system by multiple reactions monitoring mode. The ionization was optimized using ESI(−) and selectivity was achieved by MS/MS analysis, m/z 338.0 → 77.5 and m/z 357.1 → 327.2 for topiramate and prednisone, respectively. The method had a total run time of 2.5 min and showed good linearity over a working range of 20–5000 ng/mL in human plasma with a lower limit of quantification of 20 ng/mL. No metabolic compounds were found to interfere with the analysis. The inter‐day and intra‐day accuracy were in the ranges of 99.24–116.63 and 93.45–108.68%, respectively, and inter‐day and intra‐day precisions were below 6.24 and 5.25%, respectively. This method was successfully applied for pharmacokinetic and bioequivalence studies by analysis of blood samples taken up to 96 h after an oral administration of 100 mg of topiramate in 24 healthy Korean volunteers. Copyright © 2008 John Wiley & Sons, Ltd.
Linear Analogues of Human β‐Defensin 3: Concepts for Design of Antimicrobial Peptides with Reduced Cytotoxicity to Mammalian Cells
Authors: Liu Shouping , Zhou Lei , Li Jing , Suresh Anita , Verma Chandra , Foo Yong Hwee , Yap Eric P. H. , Tan Donald T. H. , Beuerman Roger W. 
Published: March 2008

AbstractA series of engineered linear analogues [coded as F6, W6, Y6, A6, S6 and C(Acm)6] were modeled, designed, synthesized and structurally characterized by mass spectra, circular dichroism, hydrophobicity analysis and molecular modeling. We have screened antimicrobial activity, hemolysis to rabbit erythrocytes, and cytotoxicity to human conjunctival epithelial cells. No significant hemolytic effect was observed for hBD3 or from five of the six analogues [F6, Y6, A6, S6 and C(Acm)6] over the range of 3–100 μg mL−1. The six linear analogues have reduced cytotoxicity to human conjunctival epithelial cells over the range of 6–100 μg mL−1 compared to hBD3. By tuning the overall hydrophobicity of linear hBD3 analogues, reduced cytotoxicity and hemolysis were obtained while preserving the antimicrobial properties. The decreased cytotoxicity of the linear analogues is suggested to be structurally related to the removal of disulfide bridges, and the flexible structure of the linear forms, which seem to be associated with loss of secondary structure. These results suggest a new approach for guiding the design of new linear analogues of defensin peptides with strong antibiotic properties and reduced cytotoxicity to mammalian cells.
The Acylation and Phosphorylation Pattern of Lipid A from Xanthomonas Campestris Strongly Influence its Ability to Trigger the Innate Immune Response in Arabidopsis
Authors: Silipo Alba , Sturiale Luisa , Garozzo Domenico , Erbs Gitte , Jensen Tina Tandrup , Lanzetta Rosa , Dow J. Maxwell , Parrilli Michelangelo , Newman Mari‐Anne , Molinaro Antonio 
Published: March 2008

AbstractLipopolysaccharides (LPSs) are major components of the cell surface of Gram‐negative bacteria. LPSs comprise a hydrophilic heteropolysaccharide (formed by the core oligosaccharide and the O‐specific polysaccharide) that is covalently linked to the glycolipid moiety lipid A, which anchors these macromolecules to the external membrane. LPSs are one of a group of molecules called pathogen‐associated molecular patterns (PAMPs) that are indispensable for bacterial growth and viability, and act to trigger innate defense responses in eukaryotes. We have previously shown that LPS from the plant pathogen Xanthomonas campestris pv. campestris (Xcc) can elicit defense responses in the model plant Arabidopsis thaliana. Here we have extended these studies by analysis of the structure and biological activity of LPS from a nonpathogenic Xcc mutant, strain 8530. We show that this Xcc strain is defective in core completion and introduces significant modification in the lipid A region, which involves the degree of acylation and nonstoichiometric substitution of the phosphate groups with phosphoethanolamine. Lipid A that was isolated from Xcc strain 8530 did not have the ability to induce the defense‐related gene PR1 in Arabidopsis, or to prevent the hypersensitive response (HR) that is caused by avirulent bacteria as the lipid A from the wild‐type could. This suggests that Xcc has the capacity to modify the structure of the lipid A to reduce its activity as a PAMP. We speculate that such effects might occur in wild‐type bacteria that are exposed to stresses such as those that might be encountered during plant colonization and disease.
Walking on the Moon and on Other Extraterrestrial Bodies
Authors: Pawlowski J. , Zlokarnik M. 
Published: March 2008

AbstractIt will be shown that it is possible to predict the walking behavior of humans on extraterrestrial bodies – i.e. under different gravitational forces – by applying techniques from dimensional analysis to measurements obtained in a stationary terrestrial laboratory. These terrestrial experiments allow us to generate artificial data about extraterrestrial walking and are, therefore, of great importance for space travel as well as for extraterrestrial physiology. What at first glance appears to be an interesting application of dimensional analysis and model theory, proves in retrospect to be an elegant means for gaining important insights for space technology.
Dynamic Simulation and Optimization of a Dual‐Type Methanol Reactor Using Genetic Algorithms
Authors: Askari F. , Rahimpour M. R. , Jahanmiri A. , Khosravanipour Mostafazadeh A. 
Published: March 2008

AbstractIn this investigation, a dynamic simulation and optimization for an auto‐thermal dual‐type methanol synthesis reactor was developed in the presence of catalyst deactivation. Theoretical investigation was performed in order to evaluate the performance, optimal operating conditions, and enhancement of methanol production in an auto‐thermal dual‐type methanol reactor. The proposed reactor model was used to simulate, optimize, and compare the performance of a dual‐type methanol reactor with a conventional methanol reactor. An auto‐thermal dual‐type methanol reactor is a shell‐and‐tube heat exchanger reactor in which the first reactor is cooled with cooling water and the second one is cooled with synthesis gas. The proposed model was validated against daily process data measured of a methanol plant recorded for a period of 4 years. Good agreement was achieved. The optimization was achieve by use of genetic algorithms in two steps and the results show there is a favorable profile of methanol production rate along the dual‐type reactor relative to the conventional‐type reactor. Initially, the optimal ratio of reactor lengths and temperature profiles along the reactor were obtained. Then, the approach was followed to get an optimal temperature profile at three periods of operation to maximize production rate. These optimization approaches increased by 4.7 % and 5.8 % additional yield, respectively, throughout 4 years, as catalyst lifetime. Therefore, the performance of the methanol reactor system improves using optimized dual‐type methanol reactor.
Fischer‐Tropsch Synthesis Over Co‐Ru/γ‐Al2O3 Catalyst in Supercritical Media
Authors: Irankhah A. , Haghtalab A. 
Published: March 2008

AbstractThe Fischer‐Tropsch synthesis (FTS) in gaseous and supercritical phases was examined in a continuous, high‐pressure fixed‐bed reactor by employing a cobalt catalyst (Co‐Ru/γ‐Al2O3). The kinetic modeling of the FTS was investigated in the reactor over a 60–80 mesh cobalt catalyst. The Langmuir‐Hinshelwood kinetic equation was used for both the Fisher‐Tropsch (FT) and water gas shift (WGS) reactions. The kinetic model was applied for simulation of the reactor with 16–20 mesh cobalt catalyst. The simulation results showed a good agreement with the experimental data. The experimental data showed that higher CO conversion and lower CH4 and CO2 selectivities were achieved in supercritical media compared to the gaseous phase. The BET surface area and pore volume enhancement results provided evidence of the higher in situ extraction and greater solubility of heavy hydrocarbons in supercritical media than in gaseous phases. Furthermore, the effects of supercritical solvent such as n‐pentane, n‐hexane, n‐heptane and their mixtures were studied. Moreover, the influence of reaction temperature, H2/CO ratio, W/F(CO+H2) and pressure tuning in the supercritical media FT synthesis were investigated, as well as the effect of the supercritical fluid on the heat transfer within the reactor. The product carbon distribution had a similar shape for all types of solvents and shifted to lighter molar mass compounds with increasing temperature, H2/CO ratio, and W/F(CO+H2). Finally, the product distribution shifted to higher molar mass hydrocarbons with increasing pressure. As a result, one may conclude that a mixture of hydrocarbon products of the FTS can be used as a solvent for supercritical media in Fischer‐Tropsch synthesis.