bluuebunny/crossref_metadata_2025_split huggingface dataset:
Real Time Investigation of the Interface between a P3HT:PCBM Layer and an Al Electrode during Thermal Annealing
Authors: Kim Hyo Jung , Lee Hyun Hwi , Kim Jang‐Joo 
Published: June 2009

AbstractReal time variation of the interfacial structure between an Al electrode and a poly(3‐hexylthiophene) (P3HT):fullerene (PCBM) thin film during thermal annealing has been investigated using synchrotron X‐rays. It is found that Al atoms diffuse into the organic layer to form a thin interlayer between the Al electrode and the organic layer even during the deposition of an Al layer. The interlayer thickness and the mass density of the interlayer increases if annealed above 120 °C. The interlayer thickness depends on the annealing processes and the inter‐diffusion is accelerated by a fast annealing process. The Al diffusion reduces the preferred alignment of the (100) direction of the P3HT crystals from the surface normal direction and randomizes their orientation. The Al diffusion also helps to reduce the contact resistance in the P3HT:PCBM‐based solar cells.magnified image
An Efficient and Environmentally Friendly Method for the Synthesis of Cellulose Carbamate by Microwave Heating
Authors: Guo Yi , Zhou Jinping , Song Yongbo , Zhang Lina 
Published: June 2009

AbstractAn efficient, solvent‐free, and catalyst‐free microwave synthesis of cellulose carbamate from a mixture of native cellulose and urea is reported. The structure of the samples are characterized by elemental analysis, FT‐IR spectroscopy, X‐ray diffraction, and NMR spectrometry. Cellulose carbamates with a nitrogen content of 0.651–2.427% are obtained by microwave heating at 255 W for 2–5 min. With the introduction of carbamate groups, the hydrogen bonding and crystalline structure of the native cellulose are partially destroyed. The products retain the cellulose I crystalline form of the native cellulose, and display good solubility in NaOH solutions.magnified image
Excitation Energy Transfer in Organic Materials: From Fundamentals to Optoelectronic Devices
Authors: Laquai Frédéric , Park Young‐Seo , Kim Jang‐Joo , Basché Thomas 
Published: June 2009

AbstractIn this review, we discuss investigations of electronic excitation energy transfer in conjugated organic materials at the bulk and single molecule level and applications of energy transfer in fluorescent and phosphorescent organic light emitting devices. A brief overview of common descriptions of energy transfer mechanisms is given followed by a discussion of some basic photophysics of conjugated materials including the generation of excited states and their subsequent decay through various channels. In particular, various examples of bimolecular excited state annihilation processes are presented. Energy transfer studies at the single molecule level provide a new tool to study electronic couplings in simple donor/acceptor dyads and conjugated polymers. Finally, energy transfer in organic electronic devices is discussed with particular emphasis on triplet emitter doped OLEDs and blends for white light emission.magnified image
Hot Topics in Polysaccharide Chemistry – Selected Examples
Authors: Heinze Thomas 
Published: June 2009

AbstractSummary: The paper highlights recent developments in polysaccharide chemistry. Cellulose tert‐butyl‐ and thexyldimethylsilyl ethers with degree of substitution up to 2 were accessible and comprehensively characterized by means of NMR spectroscopy. These derivatives enable the preparation of 3‐O‐functionalized cellulose ethers. Especially the allyl ether as protecting group at position 3 can be used for the synthesis of 2,6‐di‐O‐methyl cellulose. Nucleophilic displacement reactions of cellulose p‐toluenesulfonic acid esters with amines afforded deoxyamino celluloses that form stable monolayers on different substrates. Based on 6‐deoxy‐6‐azido cellulose, dendrons with a focal alkyne moiety were bound via the copper(I) catalyzed Huisgen reaction. Moreover, dextran derivatives were synthesized that form stable nanoparticles useful, e.g., for the determination of the pH value in biological systems.
Synthesis and Bioactivity of Cellulose Derivatives
Authors: Zhang Kai , Peschel Dieter , Brendler Erica , Groth Thomas , Fischer Steffen 
Published: June 2009

AbstractSummary: Cellulose derivatives having carboxyl‐ or carboxymethyl‐ and sulphate groups were synthesized with control of reaction conditions to regulate the distribution of substituents and molecular weights of the products. Sodium cellulose sulphates (NaCS) were synthesized through acetosulphation of cellulose or direct sulphating of cellulose and cellulose‐2.5‐acetate (C2.5A). The properties of the products were controlled by choice of starting materials and reaction parameters like reaction temperature and duration. Cellulose sulphates containing carboxyl groups were prepared through oxidation with 2,2,6,6‐tetramethylpiperidine‐1‐oxyl radical (TEMPO)/NaBr/NaClO in water or through carboxymethylation with chloroacetic acid after alkali treatment with sodium hydroxide. The biological activity of the products was analyzed with a binding assay to fibroblast growth factor (b‐FGF). It was found that NaCS with maximum O‐6‐sulfation and intermediate to high O‐2‐sulfation was able to bind b‐FGF comparable to natural heparin. Products being sulphated and afterwards carboxymethylated at all three positions were also able to bind substantial quantities of b‐FGF.
Cotton Linters: An Alternative Cellulosic Raw Material
Authors: Sczostak Axel 
Published: June 2009

AbstractSummary: Cellulose in fibrous or in chemically modified form plays a relevant part in products for industrial applications and in products which are used in human daily life. Besides wood, cotton is an important natural source for cellulose. Linters are a by‐product of the oil mills. The position of the linters in the technology of cotton is explained. In linters bleaching plant, the raw linters are purified mechanically and chemically. The principle of this process is shown. The resulting bleached linters (cotton linters pulp, CLP/cotton linters cellulose, CLC) have an alpha‐cellulose content of about 99%. Due to their purity and to their properties, the cotton linters pulp is the cellulosic basis for a large number of special and niche products in the paper and chemical industry.
Unconventional Cellulose Products Through Nucleophilic Displacement Reactions
Authors: Petzold‐Welcke Katrin , Michaelis Nico , Heinze Thomas 
Published: June 2009

AbstractSummary: The paper highlights the synthesis of unconventionally functionalized cellulose derivatives obtained by nucleophilic displacement (SN) reactions. The key intermediates, cellulose sulphonates, are discussed due to the fact that sulphonate groups play the major role as leaving group in SN reactions with the biopolymer. A short overview about “classical” SN reactions will be given. The main part of the review is focused on novel cellulose products in particular aminodeoxy cellulose derivatives showing monolayer formation, click chemistry with cellulose starting from deoxyazido (copper‐catalyzed Huisgen reaction) yielding products with methylcarboxylate‐, 2‐aniline‐, 3‐thiophene moieties, e.g., and new selectively dendronized cellulose based materials. Structure characterization and typical applications are briefly reviewed as well.
Unconventional Reactivity of Cellulose Dissolved in Ionic Liquids
Authors: Schöbitz Michael , Meister Frank , Heinze Thomas 
Published: June 2009

AbstractSummary: Ionic Liquids (IL) were applied as solvent and reaction medium in the field of homogeneous cellulose chemistry. Whereas investigations on tosylation and nucleophilic displacement reactions lead to unexpected products the application of the Huisgen reaction was successful. The standard conditions for tosylation of cellulose using the IL 1‐ethyl‐3‐methylimidazolium acetate (EMImAc) as solvent lead exclusively to cellulose acetate, due to activation of the acetate ion of the IL by forming a mixed anhydride with p‐toluenesulfonyl chloride. Further investigations showed that the anions of EMImAc and 1‐ethyl‐3‐methylimidazolium chloride (EMImCl) are able to act as nucleophiles, thus substituting tosyl groups of tosylcellulose and forming unexpected products. Using EMImAc as solvent first to third generation propargyl‐polyamidoamine (PAMAM) dendrons were attached to 6‐azido‐6‐deoxy cellulose (degree of substitution, DS 0.75) utilising the copper catalysed Huisgen reaction leading to novel dendronized cellulose derivatives with DS values of up to 0.60. Detailed structure characterisation of the products, including elemental analysis, FTIR and NMR spectroscopy, indicates that the synthesis approach leads to products without impurities or remaining IL.
Possibilities for the Physical Modification of Cellulose Shapes Using Ionic Liquids
Authors: Wendler Frank , Kosan Birgit , Krieg Markus , Meister Frank 
Published: June 2009

AbstractSummary: Functional cellulose shapes offer valuable properties for innovative application potentials in textile and medical products. Thereby excellent textile physiological properties of cellulose are allowed to be connected with novel application characteristics like bioactivity, electrical conductivity, heat storage or ability to adsorb liquids or gases. A very advantageous way to modify the properties of fibres, films or textile structures is to introduce particular additives via the Lyocell process. Regard to technical applications, functional additives will be able to incorporate themselves in the shape matrix and, in the case of using N‐methylmorpholine‐N‐oxide monohydrate (NMMO) as solvent, implicate massive technological difficulties and deterioration of properties of the spinning dope. Beside a couple of limiting moments, ionic liquids (ILs) offer as direct solvents an excellent chance for physical modification of cellulose shapes. In contrast to NMMO, they exhibit a significantly higher thermal stability as well as a higher chemical resistance. ILs exhibit most widely a better dissolving capability for a number of different polymers. First results of the development of adsorber materials as well as novel bioactive fibres will be discussed and fibre characteristics will be given.
Bio‐Based Nanocomposites of Cellulose Acetate and Nano‐Clay with Superior Mechanical Properties
Authors: Hassan‐Nejad Mehdi , Ganster Johannes , Bohn Andreas , Pinnow Manfred , Volkert Bert 
Published: June 2009

AbstractSummary: Bio‐based nanocomposites were manufactured by melt intercalation of nanoclays and cellulose acetate (CA) with and without plasticizer. Glycerol triacetate (triacetin) as plasticizer up to 30 mass%, and different types of organo‐modified and unmodified montmorillonites (MMTs) as filler were used. X‐ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM), were used to study clay dispersion, intercalation/exfoliation, and structure of the composites. XRD and TEM revealed very good dispersion and exfoliation of modified clay throughout the CA matrix. While for unmodified clay agglomeration and poor dispersion but an intercalated structure was observed. The mechanical properties of injection moulded test bars were determined by a tensile experiment giving tensile strength, Young's modulus and elongation at break. Adding plasticizer facilitated the processing and up to 20 mass%, increased the tensile strength, Young's modulus and elongation at break as well. Higher amount of plasticizer diminished the tensile properties except elongation showing a slight increase. In all plasticized composites, organo‐modified clay improved the tensile strength and at the same time, young's modulus and elongation almost remained constant. On the other hand, plasticized CA compounded with unmodified clay revealed lower properties. In a particular case, compounding of unplasticized CA with unmodified clay resulted in superior mechanical properties with a novel structure. So that, in optimum percentage –5 mass%‐ of unmodified clay, tensile strength and young's modulus increased significantly by 335% and 100%, to 178 MPa and 8.4 GPa, respectively. This is a dramatic improvement in strength and stiffness of CA. Adding organo‐modified clay resulted in a little improvement in tensile properties. SEM pictures of the optimum composite showed a core/shell structure with high orientation in the shell part. It is supposed that this behaviour is caused by the interaction between CA hydroxyl groups and free cations existing in the galleries of unmodified clay.
Correlations between gray matter reductions and cognitive deficits in dementia with Lewy Bodies and Parkinson's disease with dementia
Authors: Sanchez‐Castaneda Cristina , Rene Ramon , Ramirez‐Ruiz Blanca , Campdelacreu Jaume , Gascon Jordi , Falcon Carles , Calopa Matilde , Jauma Serge , Juncadella Montserrat , Junque Carme 
Published: June 2009

AbstractThere is controversy regarding whether Dementia with Lewy Bodies (DLB) and Parkinson's disease with dementia (PDD) may or not be different manifestations of the same disorder. The purpose of the present study was to investigate possible correlations between brain structure and neuropsychological functions in clinically diagnosed patients with DLB and PDD. The study sample consisted of 12 consecutively referred DLB patients, 16 PDD patients, and 16 healthy control subjects recruited from an outpatient setting, who underwent MRI and neuropsychological assessment. Voxel‐based morphometry results showed that DLB patients had greater gray matter atrophy in the right superior frontal gyrus, the right premotor area and the right inferior frontal lobe compared to PDD. Furthermore, the anterior cingulate and prefrontal volume correlated with performance on the Continuous Performance Test while the right hippocampus and amygdala volume correlated with Visual Memory Test in the DLB group. In conclusion, DLB patients had more fronto‐temporal gray matter atrophy than PDD patients and these reductions correlated with neuropsychological impairment. © 2009 Movement Disorder Society
1H and 13C NMR chemical shift assignments and conformational analysis for the two diastereomers of the vitamin K epoxide reductase inhibitor brodifacoum
Authors: Cort John R. , Cho Herman 
Published: June 2009

AbstractProton and 13C NMR chemical shifts and 1H1H scalar couplings for the two diastereomers of the potent vitamin K epoxide reductase (VKOR) inhibitor brodifacoum have been determined at 293 K from acetone solutions containing both diastereomers. To facilitate difficult assignments, homo‐ and heteronuclear correlation spectra were acquired at 750 and 900 MHz over 268–303 K temperature range. Conformations of both diastereomers inferred from the scalar couplings and 1‐D NOE measurements reveal that one diastereomer (SS/RR) adopts a strained geometry in the cyclohexene ring system of the tetralin group. The NMR spectra also show evidence of line broadening due to conformational exchange at room temperature for the SR/RS diastereomer. These assignments and conformational analyses may be useful in studies of biomolecular interactions of brodifacoum with target proteins such as VKOR and in source determination of brodifacoum. Copyright © 2009 John Wiley & Sons, Ltd.
Structure elucidation and NMR assignments for curcuminoids from the rhizomes of Curcuma longa
Authors: Li Wei , Wang Shisheng , Feng Jiatao , Xiao Yuansheng , Xue Xingya , Zhang Hui , Wang Yaqin , Liang Xinmiao 
Published: June 2009

AbstractThirteen curcuminoids (1–13) were isolated from the rhizomes of Curcuma longa. Among them, 1,5‐dihydroxy‐1,7‐bis(4‐hydroxyphenyl)‐4,6‐heptadiene‐3‐one (1), 1,5‐dihydroxy‐1‐(4‐hydroxy‐3‐methoxyphenyl)‐7‐(4‐hydroxyphenyl)‐4,6‐heptadiene‐3‐one (2), 1,5‐dihydroxy‐1‐(4‐hydroxyphenyl)‐7‐(4‐hydroxy‐3‐methoxyphenyl)‐4,6‐heptadiene‐3‐one (3), and 3‐hydroxy‐1,7‐bis‐(4‐hydroxyphenyl)‐6‐heptene‐1,5‐dione (4) are new compounds, and 1‐(4‐hydroxyphenyl)‐7‐(3, 4‐dihydroxyphenyl)‐1, 6‐heptadiene‐3, 5‐dione (5) is isolated from natural sources for the first time. The structures of these compounds were elucidated by extensive spectroscopic analyses, especially 1D and 2D NMR spectroscopy. The 13C NMR data and complete 1H and 13C NMR assignments of some known compounds are reported for the first time. In addition, the errors of 1H and 13C assignments reported in the literature were corrected. Copyright © 2009 John Wiley & Sons, Ltd.
Two characterizations of matrices with the Perron–Frobenius property
Authors: Elhashash Abed , Szyld Daniel B. 
Published: June 2009

AbstractTwo characterizations of general matrices for which the spectral radius is an eigenvalue and the corresponding eigenvector is either positive or nonnegative are presented. One is a full characterization in terms of the sign of the entries of the spectral projector. In another case, different necessary and sufficient conditions are presented that relate to the classes of the matrix. These characterizations generalize well‐known results for nonnegative matrices. Copyright © 2009 John Wiley & Sons, Ltd.
An investigation of the giving behavior of loyal, lapsed, and non‐givers to a religious organization
Authors: Notarantonio Elaine M. , Quigley Charles J. 
Published: June 2009

Abstract

This paper provides a comparative study of the giving behavior of current donors (CDs), lapsed donors (LDs), and non‐donors (NDs) in a Catholic diocese in New England. Focus groups were conducted and surveys were administered to Catholics to compare the attitudes and behaviors of lapsed and active donors as well as those who had not given to a recent diocesan annual campaign. The results show significant differences between the groups. Active donors indicate a much greater level of satisfaction with the church, are more aware of its programs, and feel they are more recognized for their gifts than do lapsed or NDs. These findings suggest that relationship fundraising, and creating trust, are critical to forging and maintaining valued donor relationships. The program implemented by the diocese as a result of the study is described.
Marketing for religious organizations
Lapsed donors
Nonprofit marketing
Marketing for churches
Copyright © 2009 John Wiley & Sons, Ltd.
Taking the time to listen, learn and act—an example of complex international dialogue
Authors: Osborne Peter , Huston Robbie 
Published: June 2009

Abstract

Increased low‐level radioactive discharges from Sellafield in West Cumbria began to attract strong criticism from Norwegian Ministers, media, NGOs and local
community groups during 2001. The best practicable environmental option was to discharge Technetium‐99 to sea but these discharges were beginning to be detected at very low levels around the Norwegian coast. During the early part of dialogue it was accepted that there were no known health or environmental impact from these discharges. However, the Norwegians were concerned that perceptions could impact adversely on their fishery industries and associated communities.

As a result, Sellafield increasingly became the focus of protests from Norway that on occasions resulted in lawful direct action by Norwegian stakeholders. The Norwegian “Stop Sellafield” campaign was established. In response, BNFL's company's relationship management programme set out to transform a confrontational relationship to a consensus‐building one involving Government Ministers, politicians, local communities and regulators from both the UK and Norway. Some three years of intense dialogue, which is still ongoing, facilitated the implementation of a technical solution that resolved the discharges issue‐a true win‐win scenario.

Copyright © 2009 John Wiley & Sons, Ltd.
Phosphorus containing hydrogels
Authors: Ilia Gheorghe 
Published: June 2009

AbstractSince the discovery of poly(2‐hydroxyethyl methacrylate) by Wichterle and Lim in 1960, hydrogels have been of great interest to biomedical scientists. Hydrogels are three dimensional hydrophilic polymer networks capable of swelling in water or biological fluids and retaining a large amount of fluids in the swollen state. In the last decade, hydrogels containing organophosphorus moieties were synthesized and used for proton conducting membrane, drug carriers, and scaffold for tissue engineering, pharmaceutical formulation, cosmetics, and bioseparation. One of the most versatile and rapidly developing classes of biomedical polymers is a family of polymers with a nitrogen and phosphorus backbone—polyphosphazenes. The advantage of the phosphorus–nitrogen backbone is that it can be rendered hydrolytically unstable when combined with appropriate side groups. Because of the tremendous variety of substituents that can be introduced in their structure, phosphazene polymers exhibit a very broad and sophisticated spectrum of chemical and physical properties leading to almost unlimited possibilities in the preparation of biodegradable materials Copyright © 2009 John Wiley & Sons, Ltd.
Ultrafine ibuprofen‐loaded polyvinylpyrrolidone fiber mats using electrospinning
Authors: Yu Deng‐Guang , Zhang Xiao‐Fei , Shen Xia‐Xia , Brandford‐White Chris , Zhu Li‐Min 
Published: June 2009

AbstractBACKGROUND: Drug‐loaded electrospun ultrafine fibers have the advantages of both nanoscale drug delivery systems and conventional solid dosage forms. To improve the control of drug release, the combined use of electrospinning and pharmaceutical polymers has attracted increasing interest recently.RESULTS: Ultrafine drug‐loaded polyvinylpyrrolidone fibers were successfully prepared using an electrospinning process with ibuprofen as the active pharmaceutical ingredient and polyvinylpyrrolidone K30 as the filament‐forming polymer. The analytical results from scanning electron microscopy, differential scanning calorimetry and Fourier transform infrared spectroscopy indicated that the drug had good compatibility with the polymer and that the drug was well distributed in the ultrafine fibers as an amorphous physical form. In vitro dissolution tests showed that the fiber mats were able to dissolve within 10 s through a polymer‐controlled mechanism.CONCLUSION: The fast dissolution of drug‐loaded fibers may lead to applications that improve dissolution rates of poorly water‐soluble drugs, or that involve the preparation of oral fast‐dissolving drug delivery systems. Copyright © 2009 Society of Chemical Industry
Plasma Nanostructuring of Polymers: Different Routes to Superhydrophobicity
Authors: Milella Antonella , Di Mundo Rosa , Palumbo Fabio , Favia Pietro , Fracassi Francesco , d'Agostino Riccardo 
Published: June 2009

AbstractIn this paper, we review different plasma processes developed in our laboratory to obtain nanostructured superhydrophobic polymer surfaces. All methods consist of a single step and lead to functional materials which combine a fluorinated chemistry with unique surface morphologies. The transition from sticky to slippery superhydrophobicity, crucial for several applications ranging from microfluidics to outdoor self‐cleaning surfaces, is found by properly tuning process parameters. Methods are compared in terms of process time‐scale and compatibility to different substrates.magnified image
Export chaperone SecB uses one surface of interaction for diverse unfolded polypeptide ligands
Authors: Lilly Angela A. , Crane Jennine M. , Randall Linda L. 
Published: June 2009

AbstractSecB, a remarkable chaperone involved in protein export, binds diverse ligands rapidly with high affinity and low specificity. Site‐directed spin labeling and electron paramagnetic resonance spectroscopy were used to investigate the surface of interaction on the export chaperone SecB. We examined SecB in complex with the unfolded precursor form of outer membrane protein OmpA as well as with a truncated version of OmpA that includes the transmembrane domain and lacks both the signal peptide and the periplasmic domain. In addition, we studied the binding of SecB to the unfolded mature form of galactose‐binding protein, a soluble periplasmic protein. We have previously used the same strategy to map the binding surface for the precursor of galactose‐binding protein. We show that for all ligands tested the patterns of contact are the same.