bluuebunny/crossref_metadata_2025 huggingface dataset:
Phytogenic resources of halophytes of Central Asia and their role for rehabilitation of sandy desert degraded rangelands
Authors: Toderich K. N. , Shuyskaya E. V. , Ismail S. , Gismatullina L. G. , Radjabov T. , Bekchanov B. B. , Aralova D. B.
Published: June 2009

Based on soil characteristics, watertable level, mineral composition of plant biomass, morphological/reproductive traits and carbon discrimination values, a new concept for the classification of halophytes was developed. Six main groups of halophytes have been described within the desert flora of Central Asia. Significant changes on chemical contents of ions: Cl−, SO, HCO, Na+, K+, Ca2+ and Mg2+among 23 studied halophytic forage species were revealed. Alhagi pseudoalhagi, Poaceae spp., Artemisia diffusa containing minimum concentration of mineral ions were categorised as relatively more palatable and valuable feed for livestock on open grazing and as hay. Fresh biomass of forage species growing under highly saline soils sharply decreased with increasing of salinity gradient. Potassium concentration was found highest in Kochia scoparia, Agropyron desertorum, closely followed by Atriplex nitens, Suaeda salsa, while annuals Salsola spp., Bromus tectorum, Aeluropus littoralis, Tamarix hispida, Eremopyrum orientale, Agropyron desertorum contain low amount of mineral ions because excess of salts are exuded through salt glands present abundantly on the surface of the epidermis. Native and exotic, both C3 and C4, halophytes are suitable for reclamation of degraded lands have been proven very useful in demonstration trials. The fresh biomass of investigated C3 plants sharply decreased with the increasing of soil salinity gradient. An integrated Biosaline Agriculture model for sustainable and integrated use of marginal mineralised water resources and salt‐affected soils through involvement of food–feed salt/drought tolerant crops and forage legumes to improve food security, alleviate poverty and enhance ecosystem health in smallholder crop–livestock systems has been demonstrated. Copyright © 2009 John Wiley & Sons, Ltd.
Effect of Motif‐Programmed Artificial Proteins on the Calcium Uptake in a Synthetic Hydrogel
Authors: Chirila Traian V. , Minamisawa Tamiko , Keen Imelda , Shiba Kiyotaka
Published: June 2009

Motif‐programmed artificial proteins with mineralization‐related activity were covalently immobilized onto the surface of a hydrogel, poly(2‐hydroxyethyl methacrylate) (PHEMA). We investigated the influence of assaying conditions upon the ability of three selected proteins (PS64, PS382 and PS458) to modulate calcification in vitro. A long‐term assay measuring the real amount of calcium phosphate phase in the protein‐modified PHEMA showed that all proteins enhanced the uptake of calcium by the hydrogel. For PS382 and PS458, this is a behaviour opposite to that displayed when the same proteins were tested in a free state by a rapid solution assay. Such difference may be attributed to a restricted mobility of the proteins due to immobilization.

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Anionic Ring‐Opening Polymerization of a Germanium‐Bridged [1]Ferrocenophane: Synthesis and Morphology of Well‐Defined Polyferrocenylgermane Homopolymers and Block Copolymers
Authors: Ieong Nga Sze , Manners Ian
Published: June 2009

Well‐defined poly(ferrocenyldimethylgermane) homopolymers PFDMG [$\overline M _{\rm n} $ = 18 800–33 700, degree of polymerization ($\overline {DP} _{\rm n} $) = 66–117, polydispersity index (PDI) = 1.02–1.05] and polyisoprene‐block‐poly(ferrocenyldimethylgermane) diblock copolymers (PIx‐b‐PFDMGy, for 6, x/y = 359:23, volume fraction, ϕPFDMG = 0.14, PDI = 1.04; for 7, x/y = 337:56, ϕPFDMG = 0.29, PDI = 1.04) have been prepared by anionic ring‐opening polymerization. The polymer morphology and thermal transition behaviour of PFDMG 5 ($\overline M _{\rm n} $ = 18 800, $\overline {DP} _{\rm n} $ = 66, PDI = 1.02) have been investigated by wide‐angle X‐ray scattering (WAXS) and differential scanning calorimetry (DSC), respectively. Both studies suggest that PFDMG 5 possesses similar crystallization behaviour to its Group 14 analogue, poly(ferrocenyldimethylsilane). Transmission electron microscopy (TEM) images of the solid state thin films of the diblock copolymers 6 (ϕPFDMG = 0.14) and 7 (ϕPFDMG = 0.29) show microphase separated structures of spherical or cylindrical PFDMG domains in a PI matrix respectively. Furthermore, these morphologies can be preserved after selective plasma etching of the PI block.

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Natural Brazilian Amazonic (Curauá) Fibers Modified with Polyaniline Nanoparticles
Authors: Souza Fernando G. , Oliveira Geiza E. , Rodrigues Cezar H. M. , Soares Bluma G. , Nele Márcio , Pinto José Carlos
Published: June 2009

The surface of natural Brazilian amazonic fibers (curauá, Ananas erectifolius) was modified with polyaniline nanoparticles, through in situ preparation of polyaniline nanoparticles in presence of the curauá fibers. This allowed for a significant increase in the electrical conductivity of the fibers (≈2 500 times). As the electrical resistivity of the modified fibers is a function of the applied external pressure, the produced composites can be used as a cheap pressure‐sensing material. The modified materials were also characterized by FT‐IR, XPS and SAXS, and the obtained results were used to explain some of the observed characteristics of the materials.

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Supramolecular Self‐Assembly of Nonlinear Amphiphilic and Double Hydrophilic Block Copolymers in Aqueous Solutions
Authors: Ge Zhishen , Liu Shiyong
Published: June 2009

Supramolecular self‐assembly of block copolymers in aqueous solution has received ever‐increasing interest over the past few decades due to diverse biological and technological applications in drug delivery, imaging, sensing and catalysis. In addition to relative block lengths, molecular weights and solution conditions, chain architectures of block copolymers can also dramatically affect their self‐assembling properties in selective solvents. This feature article mainly focuses on recent developments in the field of supramolecular self‐assembly of amphiphilic and double hydrophilic block copolymers (DHBCs) possessing nonlinear chain topologies, including miktoarm star polymers, dendritic–linear block copolymers, cyclic block copolymers and comb‐shaped copolymer brushes.

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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

Real 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.

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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

An 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.

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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

In 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.

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Hot Topics in Polysaccharide Chemistry – Selected Examples
Authors: Heinze Thomas
Published: June 2009

Summary: 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

Summary: 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

Summary: 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

Summary: 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

Summary: 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

Summary: 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

Summary: 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

There 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

Proton 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

Thirteen 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

Two 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

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

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

Since 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

BACKGROUND: 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

In 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.

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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

SecB, 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.
Rhizobacteria‐mediated resistance against the blackeye cowpea mosaic strain of bean common mosaic virus in cowpea (Vigna unguiculata)
Authors: Udaya Shankar Arakere Chunchegowda , Chandra Nayaka Siddaiah , Niranjan‐Raj Sathyanarayana , Bhuvanendra Kumar Hanumanthaiah , Reddy Munagala S , Niranjana Siddapura Ramachandrappa , Prakash Harishchandra Sripathy
Published: June 2009

BACKGROUND: The present study investigated the effect of seven Bacillus‐species plant‐growth‐promoting rhizobacteria (PGPR) seed treatments on the induction of disease resistance in cowpea against mosaic disease caused by the blackeye cowpea mosaic strain of bean common mosaic virus (BCMV).

RESULTS: Initially, although all PGPR strains recorded significant enhancement of seed germination and seedling vigour, GBO3 and T4 strains were very promising. In general, all strains gave reduced BCMV incidence compared with the non‐bacterised control, both under screen‐house and under field conditions. Cowpea seeds treated with Bacillus pumilus (T4) and Bacillus subtilis (GBO3) strains offered protection of 42 and 41% against BCMV under screen‐house conditions. Under field conditions, strain GBO3 offered 34% protection against BCMV. The protection offered by PGPR strains against BCMV was evaluated by indirect enzyme‐linked immunosorbent assay (ELISA), with lowest immunoreactive values recorded in cowpea seeds treated with strains GBO3 and T4 in comparison with the non‐bacterised control. In addition, it was observed that strain combination worked better in inducing resistance than individual strains. Cowpea seeds treated with a combination of strains GBO3 + T4 registered the highest protection against BCMV.

CONCLUSION: PGPR strains were effective in protecting cowpea plants against BCMV under both screen‐house and field conditions by inducing resistance against the virus. Thus, it is proposed that PGPR strains, particularly GBO3, could be potential inducers against BCMV and growth enhancers in cowpea. Copyright © 2009 Society of Chemical Industry
Explanations for long‐distance counter‐urban migration into fringe areas in Denmark
Authors: Andersen Hans Skifter
Published: June 2009

In Denmark, as in most other European countries, there is a net migration from the less urbanized to the more urbanized parts of the country. This article summarizes the results of a Danish study on the extent and composition of migration flows; and on factors and conditions that have a decisive influence on migration to fringe areas. The study shows that a considerable share of movers to the fringe areas in Denmark can be characterised as income‐transfer mover. They are people without employment moving to get lower housing costs. But there are also groups of people moving to employment in the areas, going back to places where they have grown up or moving to better housing conditions in a more natural environment. Copyright © 2009 John Wiley & Sons, Ltd.
Effective surface passivation of crystalline silicon by rf sputtered aluminum oxide
Authors: Li Tsu‐Tsung , Cuevas Andres
Published: June 2009

In recent years, excellent surface passivation has been achieved on both p‐type and n‐type surfaces of silicon wafers and solar cells using aluminum oxide deposited by plasma‐assisted atomic layer deposition. However, alternative deposition methods may offer practical advantages for large‐scale manufacturing of solar cells. In this letter we show that radio‐frequency magnetron sputtering is capable of depositing negatively‐charged aluminum oxide and achieving good surface passivation both on p‐type and n‐type silicon wafers. We thus establish that sputtered aluminum oxide is a very promising method for the surface passivation of high efficiency solar cells. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Robot‐assisted laparoscopic surgery in gynaecological oncology; initial experience at Oslo Radium Hospital and 16 months follow‐up
Authors: Sert M. Bilal , Eraker Runar
Published: June 2009

Background

This study aimed to report our initial experience using the Da Vinci®, a three‐armed Intuitive Surgical robotic unit, in relation to gynae‐oncological operations.

Methods

A prospective database was used in this retrospective analysis of 53 consecutive women with gynae‐oncological diseases who were operated by the same surgeon in a single institution. All the patients were informed of the risks inherent with each surgical procedure as well as the potential advantages.

Results

125 different procedures were performed, including total robotic radical hysterectomy (n = 25), restaging with total hysterectomy and bilateral salpingo‐oophorectomy, total omentectomy, appendectomy, bilateral pelvic and para‐aortic node dissections. Mean age of the patients, 45.8 (range 27–70) years; mean operative time, 219 (range 110–530) min; mean console time, 170 (range 60–445) min; mean estimated blood loss, 57 (range 10–300) ml; mean post‐operative stay, 3 (range 1–6) days. No robot‐related complications occurred. No conversions were reported. Mean follow‐up time was 16 (range 0–28) months.

Conclusions

Our preliminary experience with robotic surgery suggest that it is a safe technique and could allow complex radical operations to be performed with greater precision. Copyright © 2009 John Wiley & Sons, Ltd.
Robust MIMO disturbance observer analysis and design with application to active car steering
Authors: Güvenç Bilin Aksun , Güvenç Levent , Karaman Sertaç
Published: June 2009

A multi‐input–multi‐output extension of the well‐known two control degrees‐of‐freedom disturbance observer architecture that decouples the problem into single‐input–single‐output disturbance observer loops is presented in this paper. Robust design based on mapping D‐stability and the frequency domain specifications of weighted sensitivity minimization and phase margin bound to a chosen controller parameter space is presented as a part of the proposed design approach. The effect of the choice of disturbance observer Q filter on performance is explained with a numerical example. This is followed by the use of structured singular values in the robustness analysis of disturbance observer controlled systems subject to structured, real parametric and mixed uncertainty in the plant. A design and simulation study based on a four wheel active car steering control example is used to illustrate the methods presented in the paper. Copyright © 2009 John Wiley & Sons, Ltd.
Cluster analysis using multivariate mixed effects models
Authors: Villarroel Luis , Marshall Guillermo , Barón Anna E.
Published: June 2009

A common situation in the biological and social sciences is to have data on one or more variables measured longitudinally on a sample of individuals. A problem of growing interest in these areas is the grouping of individuals into one of two or more clusters according to their longitudinal behavior. Recently, methods have been proposed to deal with cases where individuals are classified into clusters through a linear model of mixed univariate effects deriving from a longitudinally measured variable. The method proposed in the current work deals with the case of clustering and then classification based on two or more variables measured longitudinally, through the fitting of non‐linear multivariate mixed effect models, and with consideration given to parameter estimation for balanced and unbalanced data using an EM algorithm. The application of the method is illustrated with an example in which the clusters are identified and the classification into clusters is compared with the true membership of individuals in one of two groups, which is known at the end of the follow‐up period. Copyright © 2009 John Wiley & Sons, Ltd.
Journal of Statistical Software
Authors: Leeuw Jan de
Published: June 2009

The Journal of Statistical Software is an e‐journal that publishes and reviews open source statistical software. We discuss the history, motivation, and implementation of the journal. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Applications of Computational Statistics > Organizations and Publications
Massive datasets
Authors: Kettenring Jon R.
Published: June 2009

Massive datasets are so labeled because of their size and complexity. They do not yield readily to standard statistical analyses. The resulting frustration has served as a spur to researchers to develop better tools. Some progress has been made, but the need for considerably more explains why this line of research remains a top priority. Interdisciplinary teamwork is at least as important as tools and can be the key to cracking the hard challenges that these datasets pose. This review includes background information, examples, and statistical strategies to illustrate the state‐of‐the‐art. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Data: Types and Structure > Massive Data
Filtered kernel density estimation
Authors: Marchette David
Published: June 2009

This article describes a multiple‐bandwidth version of the kernel estimator for nonparametric probability density estimation, in which the bandwidths are chosen using a set of functions, called filter functions, which determine the support of the density appropriate to the different bandwidths. These filter functions are usually defined using a normal mixture fit to the data. Thus the estimator uses different bandwidths in different regions of the support of the distribution, as controlled by the filter functions. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Density Estimation
Cholesky factorization
Authors: Higham Nicholas J.
Published: June 2009

This article aimed at a general audience of computational scientists, surveys the Cholesky factorization for symmetric positive definite matrices, covering algorithms for computing it, the numerical stability of the algorithms, and updating and downdating of the factorization. Cholesky factorization with pivoting for semidefinite matrices is also treated. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Algorithms and Computational Methods > Numerical Methods
Introducing WIREs Computational Statistics
Authors: Wegman Edward J. , Said Yasmin H. , Scott David W.
Published: June 2009

This article is categorized under:

Applications of Computational Statistics > Organizations and Publications
Evolutionary computation
Authors: Jong Kenneth De
Published: June 2009

This article provides a brief overview of the field of Evolutionary Computation. It describes the important historical developments that shaped the field. It summarizes the field as it exists today and discusses some of the important directions in which the field is developing. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Algorithms and Computational Methods > Genetic Algorithms and Evolutionary Computing
Improvements of the low‐energy performance of a micro‐focus x‐ray source for XRF analysis with the SEM
Authors: Procop M. , Hodoroaba V.‐D. , Bjeoumikhov A. , Wedell R. , Warrikhoff A.
Published: June 2009

X‐ray Fluorescence (XRF) with a scanning electron microscope (SEM) is a valuable completion of the analytical capabilities of SEMs. Small and compact micro‐focus x‐ray sources are mounted to the microscope chamber, and the x‐ray spectra are monitored with conventional EDS systems. Up to now the x‐ray tubes used for the micro‐focus x‐ray sources are equipped with beryllium windows about 100 µm thick. The poly‐capillary x‐ray lenses have their transmission maximum at photon energies around 10 keV. It drops down in both low‐ and high‐energy ranges. Hence, L‐radiation from an Mo or Rh target will be strongly attenuated, and the excitation of fluorescence in the soft x‐ray range becomes very ineffective. A new micro‐focus x‐ray source was developed. It is characterised by a lower self‐absorption in the tube target, thin beryllium windows and an x‐ray optics having a large distance between its foci and the maximum of transmission at about 5 keV. Thus K line fluorescence of light elements becomes effectively excited by the L‐radiation from Mo or Rh tube targets. The detection limit for sodium oxide in glass was found to be below 1 mass%. Copyright © 2009 John Wiley & Sons, Ltd.
Energy‐dispersive X‐ray fluorescence analysis of a pre‐Columbian funerary gold mask from the Museum of Sicán, Peru
Authors: Cesareo Roberto , Bustamante Angel , Fabian Julio , Calza Cristiane , Dos Anjos Marcelino , Lopes Ricardo T. , Elera Carlos , Shimada Izumi , Curay Victor , Rizzutto Marcia A.
Published: June 2009

A funerary gold mask from the Museum of Sicán, Ferrañafe, Peru was analyzed in 30 different areas using a portable equipment using energy‐dispersive X‐ray fluorescence. It was deduced from the measurements that the main sheet of the mask and the majority of the pendants have a similar composition and are made of tumbaga, which means a poor gold alloy enriched at the surface by depletion gilding, and have a similar ‘equivalent’ gilding thickness of about 5 µm. The nose, also on tumbaga, has different composition and a thickness of about 8 µm. The clamps are on gilded or on silvered copper. The red pigment dispersed on the surface of the mask is cinnabar. Copyright © 2009 John Wiley & Sons, Ltd.
Vacancies and Insertions in the RE10Ni9+xIn20 Series (RE = Ho–Tm, Lu)
Authors: Thimmaiah Srinivasa , Weber Josh , Miller Gordon J.
Published: June 2009

The intermetallic compounds RE10Ni9+xIn20 (RE = Ho–Tm, Lu) have been studied experimentally as well as theoretically. Lu10Ni9.8In19.2(1) crystallizes in the tetragonal Ho10Ni9In20‐type structure [space group P4/nmm, a = 13.114(2) Å and c = 8.993(2) Å] with vacant 2b positions and mixed In/Ni occupancies at one indium site that creates the refined composition. Moreover, the atomic positions and the displacement parameters for the holmium, erbium, thulium, and lutetium phases, which are missing in previous studies, are now refined. TB‐LMTO‐ASA electronic calculations indicates that Lu10Ni9.8In19.2(1) prefers the centrosymmetric Ho10Ni9In20‐type rather than a noncentrosymmetric defect‐HfNiGa2‐type structure (I4mm). According to our theoretical investigations, the HfNiGa2‐type structure is preferred when the 2b position is fully occupied; however, the Ho10Ni9In20‐type structure is preferred when vacancies are present on 2b position.
Pd Nanoparticles and Thin Films for Room Temperature Hydrogen Sensor
Authors: Joshi Rakesh K. , Krishnan Subramanian , Yoshimura Mashamichi , Kumar Ashok
Published: June 2009

We report the application of palladium nanoparticles and thin films for hydrogen sensor. Electrochemically grown palladium particles with spherical shapes deposited on Si substrate and sputter deposited Pd thin films were used to detect hydrogen at room temperature. Grain size dependence of H2sensing behavior has been discussed for both types of Pd films. The electrochemically grown Pd nanoparticles were observed to show better hydrogen sensing response than the sputtered palladium thin films. The demonstration of size dependent room temperature H2sensing paves the ways to fabricate the room temperature metallic and metal–metal oxide semiconductor sensor by tuning the size of metal catalyst in mixed systems. H2sensing by the Pd nanostructures is attributed to the chemical and electronic sensitization mechanisms.
The Modulation of Optical Property and its Correlation with Microstructures of ZnO Nanowires
Authors: Li Haohua , Liang Chaolun , Zhong Kuan , Liu Meng , Hope Greg A. , Tong Yexiang , Liu Peng
Published: June 2009

ZnO nanowires with both good crystallinity and oxygen vacancies defects were synthesized by thermal oxidation of Zn substrate pretreated in concentrated sulfuric acid under the air atmosphere, Ar- and air-mixed gas stream. The photoluminescence spectra reveal that only near-band-edge (NBE) emission peak was observed for the sample grown in the air atmosphere; the broad blue–green and the red-shifted NBE emission peaks were observed for the sample grown in the mixed gas stream, indicating that the sample grown in the mixed gas stream has a defective structure and its optical properties can be modulated by controlling its structure. The high-resolution transmission electron microscope and the corresponding structural simulation confirm that the oxygen vacancies exist in the crystal of the nanowires grown in the mixed gas stream. The ZnO nanowires with oxygen vacancies defects exhibit better photocatalytic activity than the nanowires with good crystallinity. The photocatalytic process obeys the rules of first-order kinetic reaction, and the rate constants were calculated.
Stock Options and Total Payout
Authors: Cuny Charles J. , Martin Gerald S. , Puthenpurackal John J.
Published: June 2009

In this paper, we examine how stock option usage affects total corporate payout. Using fixed-effects panel data estimators on various samples of ExecuComp firms from 1993 to 2005, we find the higher the executive stock options, the lower the total payout, ceteris paribus. We also find some evidence that firms increase payouts through repurchases in order to offset earnings per share dilution that occurs due to usage of executive and non-executive stock options. However, incentives from not having dividend protection for options appear to dominate those from antidilution, resulting in lower total payout for firms with higher options usage.