bluuebunny/crossref_metadata_2025 huggingface dataset:
High dose intravenous immunoglobulin treatment: Mechanisms of action
Authors: Boros Peter , Gondolesi Gabriel , Bromberg Jonathan S.
Published: November 2005

Intravenous immunoglobulin (IVIg) treatment was introduced as replacement therapy for patients with antibody deficiencies, but evidence suggests that a wide range of immune-mediated conditions could benefit from IVIg. The immunoglobulins are precipitated from human plasma by fractionation methods. In conclusion, the differences in basic fractionation methods and the addition of various modifications for purification, stabilization, and virus inactivation result in products significantly different from each other. (Liver Transpl 2005;11:1469–1480.)
Liver transplantation for erythropoietic protoporphyria liver disease
Authors: McGuire Brendan M. , Bonkovsky Herbert L. , Carithers Robert L. , Chung Raymond T. , Goldstein Leonard I. , Lake John R. , Lok Anna S. , Potter Carol J. , Rand Elizabeth , Voigt Michael D. , Davis Pamela R. , Bloomer Joseph R.
Published: November 2005

In erythropoietic protoporphyria (EPP), there is excessive production of protoporphyrin, primarily in the bone marrow, resulting in increased biliary excretion of this heme precursor. Some patients will develop progressive liver disease that may ultimately require liver transplantation. However, excessive production of protoporphyrin by the bone marrow continues after transplantation, which may cause recurrent disease in the allograft. This study was performed to define post-transplant survival, the risk of recurrent disease, and specific management issues in patients transplanted for EPP liver disease. The patients studied consisted of twelve males and eight females, with an average age of 31 (range, 13–56) years at the time of transplantation. The estimated maximum MELD score prior to transplant was 21 (range, 15–29). Unique complications in the perioperative period were light induced tissue damage in four patients and neuropathy in six, requiring prolonged mechanical ventilation in four. Patient and graft survival rates were 85% at 1 year, 69% at 5 years, and 47% at 10 years. Recurrent EPP liver disease occurred in 11 of 17 patients (65%) who survived more than 2 months. Three patients were retransplanted at 1.8, 12.6, and 14.5 years after the initial transplant for recurrent EPP liver disease. In conclusion, the 5-year patient survival rate in patients transplanted for EPP liver disease is good, but the recurrence of EPP liver disease appears to diminish long term graft and patient survival. (Liver Transpl 2005;11:1590–1596.)
A case of successful enteroscopic balloon dilation for late anastomotic stricture of choledochojejunostomy after living donor liver transplantation
Authors: Haruta Hidenori , Yamamoto Hironori , Mizuta Koichi , Kita Yoshiaki , Uno Takeji , Egami Satoshi , Hishikawa Shuji , Sugano Kentaro , Kawarasaki Hideo
Published: November 2005

Biliary complications remain a major concern after living donor liver transplantation. We describe a pediatric case who underwent a successful endoscopic balloon dilatation of biliary-enteric stricture following living donor liver transplantation using a newly developed method of enteroscopy. The 7-year-old boy with late biliary stricture of choledochojejunostomy was admitted 6 years after transplantation. Since percutaneous transhepatic cholangiography was technically difficult in this case, endoscopic retrograde cholangiography was performed using a double-balloon enteroscope under general anesthesia. The enteroscope was advanced retrograde through the duodenum, jejunum, and the leg of Roux-Y by the double-balloon method, and anastomotic stricture of choledochojejunostomy was clearly confirmed by endoscopic retrograde cholangiography and endoscopic direct vision. Balloon dilatation was performed and the anastomosis was expanded. Restenosis was not noted as of 2 years after the treatment. In conclusion, endoscopic balloon dilation of biliary-enteric anastomotic stricture using a new enteroscopic method can be regarded as an alternative choice to percutaneous transhepatic management and surgical re-anatomists. (Liver Transpl 2005;11:1608–1610.)
Surface Properties of Silk Fibroin Films and Their Interaction with Fibroblasts
Authors: Servoli Eva , Maniglio Devid , Motta Antonella , Predazzer Rosanna , Migliaresi Claudio
Published: November 2005

Summary: There is a growing interest in the use of silk as a biomaterial for tissue engineering. Silk threads from Bombyx mori have a fibrous core of fibroin, the protein responsible for biocompatibility and bioactivity, which is surrounded by a family of “gummy” proteins, called sericins, which are almost completely removed during silk degumming. Three different methanol treatments on regenerated fibroin films were used to convert viscous solutions of Silk I to an insoluble crystalline form (Silk II), in an attempt to devise new processing protocols for the creation of a cell guiding fibroin surface. Human fibroblasts (MRC5 line) were used as probes of the cell‐biomaterial interaction in the early stages of the process (1 h, 3 h, 6 h and 4 d after seeding). The effect of each treatment on cell adhesion, spreading and distribution was monitored by scanning electron microscopy (SEM) and was correlated to superficial properties (like roughness and crystallinity) and fibroin conformation by means of atomic force microscopy (AFM), used in both topographical and acoustic mode, and attenuated total internal reflection infrared spectroscopy (FTIR‐ATR). It was found that traditional methanol treatments where fibroin films were soaked in methanol solution produced roughness patterns that affected only the very early stages of fibroblast adhesion (until 3 h from seeding), while the new treatment proposed could really dialogue with the cells. Its non‐homogeneous surface can explain the existence of cells spreading in specific directions and the presence of cell repellent areas even 4 d after seeding.

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Glycosidation of Cu,Zn‐Superoxide Dismutase with End‐Group Aminated Dextran. Pharmacological and Pharmacokinetics Properties
Authors: Perez Yunel , Valdivia Aimara , Gomez Leissy , Simpson Benjamin K. , Villalonga Reynaldo
Published: November 2005

Summary: Bovine Cu,Zn‐SOD was chemically modified with an end‐group aminated dextran derivative using a water‐soluble carbodiimide as coupling agent. The enzyme retained 81% of the initial catalytic activity after the attachment of about 4.4 mol of polymer per protein subunit. The anti‐inflammatory activity of the SOD was two times increased after conjugation with dextran. The modified enzyme was remarkably more resistant to inactivation by H2O2 and its plasma half‐life time was prolonged from 4 min to 3.2 h.

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Effects of Processing on the Structure of Zein/Oleic Acid Films Investigated by X‐Ray Diffraction
Authors: Wang Ying , Filho Francisco Lopes , Geil Phillip , Padua Graciela W.
Published: November 2005

Summary: Zein films plasticized with oleic acid were formed by solution casting, by the stretching of moldable resins, and by blown film extrusion. The effects of the forming process on film structure were investigated by X‐ray diffraction. Wide‐angle X‐ray scattering (WAXS) patterns showed d‐spacings at 4.5 and 10 Å, which were attributed to the zein α‐helix backbone and inter‐helix packing, respectively. The 4.5 Å d‐spacing remained stable under processing while the 10 Å d‐spacing varied with processing treatment. Small‐angle X‐ray scattering (SAXS) detected a long‐range periodicity for the formed films but not for unprocessed zein, which suggests that the forming process‐promoted film structure development is possibly aided by oleic acid. The SAXS d‐spacing varied among the samples (130–238 Å) according to zein origin and film‐forming method. X‐ray scattering data suggest that the zein molecular structure resists processing but the zein supramolecular arrangements in the formed films are dependent on processing methods.

Structural model for a zein molecular aggregate (based on Matsushima et al.10). Rectangular prisms of individual zein molecules are hexagonally aligned parallel to each other.

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Structural model for a zein molecular aggregate (based on Matsushima et al.10). Rectangular prisms of individual zein molecules are hexagonally aligned parallel to each other.
Interaction of DNA/Polycation Complexes with Phospholipids: Stabilizing Strategy for Gene Delivery
Authors: Zintchenko Arkadi , Koňák Čestmír
Published: November 2005

Summary: The interaction between negatively charged lipid vesicles and positively charged DNA/polylysine complexes was studied. The interaction does not lead to release of DNA from the initial complexes. The particles formed are easy to prepare, they have slight negative charge, small dimensions and show good stability in physiological NaCl solution. Such properties might indicate that stabilization of the particles by lipid coating might be a potent strategy, alternative to PEGylation of DNA/polycation complexes.

Interaction of DNA/polycation complex particles with lipid vesicles.

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Interaction of DNA/polycation complex particles with lipid vesicles.
Advantages of an Emulsion‐Produced Ziegler‐Natta Catalyst Over a Conventional Ziegler‐Natta Catalyst
Authors: Abboud Mohammed , Denifl Peter , Reichert Karl‐Heinz
Published: November 2005

Summary: Self‐supported and MgCl2‐supported Ziegler‐Natta catalysts, produced by two catalyst synthesis methods are compared. Borealis Polymers OY (Finland), who supplied the catalysts, developed the catalyst synthesis methods. The first method (Method One) is based on an emulsion system and consists of an in situ single step preparation. The second method (Method Two) consists mainly of two steps: formation of the catalyst carrier particles, and their subsequent impregnation with the active material. The results showed that Method One produced catalysts of compact, spherical particles with good intra‐particle homogeneity and a narrow particle size distribution. On the other hand, Method Two produced catalyst particles whose properties depended directly on that of the catalyst carrier: they were spherical but very porous, with a broad particle size distribution. Polymer particles produced with the two catalyst systems are perfect replicas of the catalyst particles. Fines formed either during catalyst preparation or during polymerization were observed only with the catalyst prepared using Method Two. The particles of the catalysts produced using Methods One and Two had similar activities, independent of the initial particle size. Fragmentation of catalyst particles was very fast for both catalyst systems and was only observed to be 100% completed using the catalyst produced with Method One. Studies of the thermal properties showed that the catalyst prepared using Method One produced poly(propylene) of higher crystallinity and with a narrower melting peak.

SEM images of polymer particles produced by (A) Method One and (B) Method Two.

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SEM images of polymer particles produced by (A) Method One and (B) Method Two.
Physical Properties of Isotactic Poly(propylene)/Silver Nanocomposites: Dynamic Crystallization Behavior and Resultant Morphology
Authors: Chae Dong Wook , Kim Byoung Chul
Published: November 2005

Summary: The presence of silver nanoparticles (0.01–5 wt.‐%) increased the crystallization temperature of isotactic poly(propylene) (iPP) (e.g., a 5 wt.‐% content increases the temperature by ca. 7 °C) and produced a sharper crystalline peak. It had little effect on the melt rheology of the nanocomposites. The shear‐induced crystallization behavior of iPP was accelerated with increasing Ag content and imposed frequency. In addition, the promoting effect of Ag nanoparticles on the overall crystallization behavior was more notable at 140 °C than at 130 °C. The wide‐angle X‐ray diffraction scans of iPP nanocomposites with 5 wt.‐% Ag crystallized at 130 °C clearly presented another peak at a 2θ value of 15.8°, which corresponded to a β‐form crystal. The nanocomposites with 5 wt.‐% Ag crystallized at 130 °C gave double melting peaks at 154 and 166 °C. On the other hand, the samples crystallized at 140 °C produced two melting peaks at 166 and 172 °C. The introduction of as much as 0.1 wt.‐% of Ag nanoparticles increased both the tensile strength and elongation at break, but subsequent further addition caused a decrease. In addition, iPP nanocomposites with more than 1 wt.‐% Ag exhibited a higher modulus than pure iPP.

Time dependence of G′ of iPP and iPP/Ag nanocomposites at 130 °C at ω = 1 rad · s−1.

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Time dependence of G′ of iPP and iPP/Ag nanocomposites at 130 °C at ω = 1 rad · s−1.
Photodegradation of Poly(L‐lactic acid): Effects of Photosensitizer
Authors: Tsuji Hideto , Echizen Yoshihisa , Saha Swapan Kumar , Nishimura Yoshiro
Published: November 2005

Summary: Amorphous and crystallized poly(L‐lactic acid) (PLLA‐A and PLLA‐C, respectively) films with different contents of N,N,N′,N′‐tetramethyl‐1,4‐phenylenediamine (TMPD) as a photosensitizer were prepared, and the effects of the addition of TMPD on the photodegradation of PLLA films were investigated. It was found that the addition of TMPD effectively enhanced the photodegradation of PLLA films and thereby decreased their molecular weight of PLLA films regardless of their crystallinity, and that PLLA films with different molecular weights can be prepared by the addition of different amounts of TMPD and subsequent UV irradiation. Too high contents of TMPD however caused the brittleness of PLLA films due to a large decrease in molecular weight. The PLLA chains in crystalline regions as well as those in amorphous regions are photodegradable even at an early stage, in marked contrast to their hydrolytic degradation, where the chains in the amorphous regions are selectively degraded. The basic changes in glass transition, cold crystallization, and melting temperatures (Tg, Tcc, and Tm, respectively) of PLLA films during UV irradiation can be ascribed to low‐temperature annealing effects; i.e., annealing‐induced stabilization in chain packing should have elevated Tg, and annealing‐induced formation of crystallite nuclei should have lowered Tcc and increased Tm. The exceptional large decreases in Tcc and Tm of UV‐irradiated PLLA‐A films and in Tg of UV‐irradiated PLLA‐C films at high TMPD contents are attributable to the large decrease in molecular weight, whereas the exceptional decrease in Tm of PLLA‐C films at high TMPD contents can be due to the folding surface structural change of crystalline regions or to the lattice disorder caused by molecular structural changes.

$\overline M _{\rm n}$ of PLLA‐A films before UV irradiation and after UV irradiation for 60 h as a function of TMPD content.

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$\overline M _{\rm n}$ of PLLA‐A films before UV irradiation and after UV irradiation for 60 h as a function of TMPD content.
The Effect of Disinfection Methods on the Mechanical Properties of Thermoplastic Recyclates
Authors: Bohlmann Birgit , Hirth Thomas , Grellmann Wolfgang , Langer Beate
Published: November 2005

Summary: Increasing environmental concern encourages the development of new ways to recycle medical products. Post‐consumer medical products are suited for recycling because of their life‐span, but used products have to be disinfected before recycling. Therefore, the influence of different disinfection processes during recycling on the processibility and the mechanical properties of thermoplastics was investigated. As disinfection processes, steam disinfection and disinfection with electron beam and gamma radiation were selected. The characterisation of the properties of disinfected recyclates was undertaken for PE and PP from syringes. The melt mass‐flow rate (MFR), the dynamic mechanical properties, the tensile properties and fracture mechanics parameters were examined. A comparison of the results showed that stiffness and strength remain nearly constant, but the deformation and fracture behaviour tends to be influenced. The selection of appropriate disinfection parameters can avoid unnecessary alteration of the properties. Thus, steam disinfection as well as radiation disinfection up to a dose of about 25 kGy are suited for decontaminating used medical products.

Scheme of the influence of different disinfection methods on selected properties of thermoplastic recyclates.

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Scheme of the influence of different disinfection methods on selected properties of thermoplastic recyclates.
PEO‐b‐PCL Block Copolymers: Synthesis, Detailed Characterization, and Selected Micellar Drug Encapsulation Behavior
Authors: Meier Michael A. R. , Aerts Sebastianus N. H. , Staal Bastiaan B. P. , Rasa Mircea , Schubert Ulrich S.
Published: November 2005

Summary: A series of poly(ethylene glycol)‐block‐poly(ε‐caprolactone) diblock copolymers was synthesized and fully characterized. In particular, MALDI‐TOF MS results revealed interesting new insights into their molecular architecture. Small and defined micelles could be prepared from these block copolymers. Utilizing a high‐throughput screening approach, it was observed that these micelles are able to encapsulate/solubilize different guest molecules (e.g. drugs) depending on the solubility of the guest in water. Furthermore, it could be proven that a guest is located within a micelle and that these micelles can be utilized as transport vehicles for the encapsulated guest molecules.

PEO‐b‐PCL diblock copolymers can encapsulate small guest molecules in the core of the polymeric micelles.

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PEO‐b‐PCL diblock copolymers can encapsulate small guest molecules in the core of the polymeric micelles.
Novel Silver/Poly(vinyl alcohol) Nanocomposites for Surface‐Enhanced Raman Scattering‐Active Substrates
Authors: Lin Wen‐Ching , Yang Ming‐Chien
Published: November 2005

Summary: Surface‐enhanced Raman scattering (SERS)‐active substrates with high enhancement were prepared by an in situ reduction method. Novel silver/poly(vinyl alcohol) (PVA) nanocomposite films were obtained, in which the silver nitrate, poly(γ‐glutamic acid) (PGA), and PVA acted as precursor, stabilizer, and polyol reducant, respectively. The UV‐visible spectra of the as‐fabricated films showed that the surface plasmon resonance (SPR) absorption band was narrow and of a stronger intensity, which indicates that the Ag nanoparticle size distribution on the substrate was highly uniform. This finding was further confirmed by X‐ray diffraction (XRD), transmission electron microscopy (TEM), and field‐emission scanning electron microscope (FE‐SEM) measurements. It was found that a PGA‐stabilized PVA nanocomposite film revealed the presence of well‐dispersed spherical silver nanoparticles with an average diameter of 90 nm. The new substrate presents high SERS enhancement and the enhanced factor is estimated to be 106 for the detection of benzoic acid.

The Raman scattering enhancement factor for the Raman spectra of benzoic acid on the various nanocomposite films.

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The Raman scattering enhancement factor for the Raman spectra of benzoic acid on the various nanocomposite films.
Effect of Substituent Orientation on Selectivity between Polymerization and Cyclization: Polycondensation of (Alkylamino)benzoic Acid Dimer Phenyl Esters
Authors: Yokoyama Akihiro , Saito Shunsuke , Shimizu Yuuki , Yokozawa Tsutomu
Published: November 2005

Summary: The polymerization characteristics of (octylamino)benzoic acid dimer phenyl esters with para‐meta (2), meta‐para (3), and meta‐meta (4) orientation of the amino and carbonyl groups were investigated. While treatment of 2 or 3 with a base gave the cyclic dimer 6 as the main product, condensation of 4 with an initiator in the presence of a base afforded polymers with narrow molecular weight distributions.

The condensation of 4 with an initiator in the presence of a base afforded polymers with narrow molecular weight distribution.

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The condensation of 4 with an initiator in the presence of a base afforded polymers with narrow molecular weight distribution.
Novel Nanoparticles Based on Dextran Esters with Unsaturated Moieties
Authors: Hornig Stephanie , Heinze Thomas , Hesse Stephanie , Liebert Tim
Published: November 2005

Summary: Applying a dialysis process, new nanoparticles based on well‐defined dextran esters of furan‐2‐carboxylic‐ and pyroglutamic acids were prepared, which can undergo cross‐linking by UV irradiation. The highly functionalized products (total DS > 2) avoid the collapse of nanoparticles due to the prevention of hydrogen bond formation. The major fraction of the dextran ester nanospheres exhibits narrow size distribution down to 250 nm as mean diameter investigated by SEM.

SEM images of dextran furoate pyroglutamate nanospheres.

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SEM images of dextran furoate pyroglutamate nanospheres.
Hydrogen‐Assisted Unique Incorporation of 1,4‐Divinylbenzene in Copolymerization with Propylene Using an Isospecific Zirconocene Catalyst
Authors: Cao Chengang , Dong Jin‐Yong , Chung Tze‐Chiang
Published: November 2005

Summary: Propylene was copolymerized with 1,4‐divinylbenzene (1,4‐DVB) using rac‐Me2Si(2‐Me‐4‐Ph‐Ind)2ZrCl2 and MAO in the presence of hydrogen. 1H NMR spectra of the obtained copolymer confirmed the successful incorporation of 1,4‐DVB. 13C NMR analysis revealed a unique copolymer structure with the incorporated 1,4‐DVB units predominantly forming 1,4‐substituted phenyl repeating units in the polymer main chain. A plausible mechanism involving spontaneous insertion of terminal styryl into Zr‐H species was proposed to rationalize the unique incorporation of 1,4‐DVB.

Copolymerization of propylene with 1,4‐divinylbenzene in the presence of hydrogen.

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Copolymerization of propylene with 1,4‐divinylbenzene in the presence of hydrogen.
Design of Surfactant‐Grafted Hydrogels with Fast Response to Temperature
Authors: Noguchi Yuji , Okeyoshi Kosuke , Yoshida Ryo
Published: November 2005

Summary: Here we show a new design concept of functional polymer gel for rapid deswelling by utilizing micelle‐forming ability of surfactant. A thermosensitive polymer bearing a surfactant was synthesized by using N‐isopropylacrylamide and a reactive surfactant. Above lower critical solution temperature, the grafted surfactant acts to form micelle structure. In the shrinking process, the inside water is rapidly squeezed out through hydrophilic channel between the formed micelles and consequently the gel shrinks quickly.

Shrinking mechanism of PNS gel in response to temperature increase.

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Shrinking mechanism of PNS gel in response to temperature increase.
Minimizing transient times in a coupled solid‐state laser model
Authors: Lenhart S. , Protopopescu V. , Workman J. T.
Published: November 2005

We consider a system of ordinary differential equations modelling the dynamics of two coupled solid‐state lasers. Under the dynamics, this system may execute transitions between in‐phase and out‐of‐phase states. For satellite communications and high‐speed data transfer the transition times should be reduced to their shortest possible duration. In this paper, we apply optimal control theory to find the values of various laser parameters (e.g. the amplitude of the injected field, detunings, and coupling constants) which minimize the transient times between out‐of‐phase and in‐phase states. The effect of each parameter is shown to be independent of the other two, and the transient time is shown to be a strictly increasing function of detuning and a strictly decreasing function of the coupling constant and amplitude of the injected field. The effect of initial conditions on transient times is also analysed. Published in 2005 by John Wiley & Sons, Ltd.
Undersampled elliptical centric view‐order for improved spatial resolution in contrast‐enhanced MR angiography
Authors: Madhuranthakam Ananth J. , Hu Houchun H. , Barger Andrew V. , Haider Clifton R. , Kruger David G. , Glockner James F. , Huston John , Riederer Stephen J.
Published: November 2005

Although contrast‐enhanced MR angiography (CE‐MRA) has been successfully developed into a routine clinical imaging technique, there is still need for improved spatial resolution in a given acquisition time. Undersampled projection reconstruction (PR) techniques maintain spatial resolution with reduced scan times, and the elliptical centric (EC) view order provides high quality arterial phase images without venous contamination. In this work, we present a hybrid elliptical centric–projection reconstruction (EC‐PR) technique to provide spatial resolution improvement over standard EC in a given time. The k‐space sampling was performed by undersampling the periphery of the kY‐kZ phase encoding plane of an EC view order in a PR like manner. The sampled views were maintained on a rectilinear grid, and thus reconstructed by standard 3DFT. The non‐sampled views were compensated either by zero‐filling or performing a 2D homodyne reconstruction. Compared to a fully sampled k‐space, the EC‐PR sequence acquired in the same scan time provides a resolution improvement of about two, as shown by point spread function analysis and phantom experiments. The hypothesis that EC‐PR provides improved resolution while retaining diagnostically adequate SNR was tested in 11 CE‐MRA studies of the popliteal and carotid arteries and shown to be true (P < 0.03). Magn Reson Med 55:000–000, 2006. © 2005 Wiley‐Liss, Inc.
Requirements for room temperature shimming of the human brain
Authors: Clare Stuart , Evans John , Jezzard Peter
Published: November 2005

Room temperature (RT) shims are used routinely in MRI to remove global and local B0 field inhomogeneity introduced by the subject. Most clinical scanners use only second‐order spherical harmonic terms, but with the increasing availability of very high field systems, third‐ and fourth‐order terms are a serious consideration. However, choosing appropriate coil strengths is of critical importance in shim coil design since overspecification of the shim strengths can lead to a variety of problems, including shim coil self‐resonance. In this study B0 field map data collected over a period of 6 months (over 400 brain volumes) were analyzed to find the characteristic B‐fields required to shim these brains. These data can be used to specify the coil requirements to effectively shim the human brain. Magn Reson Med, 2006. © 2005 Wiley‐Liss, Inc.
Fast perfusion measurements in rat skeletal muscle at rest and during exercise with single‐voxel FAIR (flow‐sensitive alternating inversion recovery)
Authors: Pohmann Rolf , Künnecke Basil , Fingerle Jürgen , Kienlin Markus von
Published: November 2005

Non‐invasive measurement of perfusion in skeletal muscle by in vivo magnetic resonance remains a challenge due to its low level and the correspondingly low signal‐to‐noise ratio. To enable accurate, quantitative, and time‐resolved perfusion measurements in the leg muscle, a technique with a high sensitivity is required. By combining a flow‐sensitive alternating inversion recovery (FAIR)‐sequence with a single‐voxel readout, we have developed a new technique to measure the perfusion in the rat gastrocnemius muscle at rest, yielding an average value of 19.4 ± 4.8 mL/100 g/min (n = 22). In additional experiments, perfusion changes were elicited by acute ischemia and reperfusion or by exercise induced by electrical, noninvasive muscle stimulation with varying duration and intensity. The perfusion time courses during these manipulations were measured with a temporal resolution of 2.2 min, showing increases in perfusion of a factor of up to 2.5. In a direct comparison, the results agreed closely with values found with microsphere measurements in the same animals. The quantitative and noninvasive method can significantly facilitate the investigation of atherosclerotic diseases and the examination of drug efficacy. Magn Reson Med, 2006. © 2005 Wiley‐Liss, Inc.
Rapid mapping of flow velocity using a new PARSE method
Authors: Zuo Jin , Walsh Edward G. , Deutsch Georg , Twieg Donald B.
Published: November 2005

A new method for flow velocity mapping is presented here. Instead of the conventional approach of employing two images (velocity sensitive and control) to generate velocity information, in the new method one determines the velocity directly from a single‐shot acquisition by solving an inverse problem. This technique is a variant of single‐shot parameter assessment by retrieval from signal encoding (SS‐PARSE). The results of simulation and phantom studies show strong agreement with the actual velocities. The prototype method can measure velocities in the range of –50 to 50 cm/s, which is roughly appropriate for future applications in dynamic blood flow measurement in carotid arteries. Magn Reson Med, 2006. © 2005 Wiley‐Liss, Inc.
Satellite cell numbers in young and older men 24 hours after eccentric exercise
Authors: Dreyer Hans C. , Blanco Cesar E. , Sattler Fred R. , Schroeder E. Todd , Wiswell Robert A.
Published: November 2005

We tested the hypothesis that the expansion of satellite cell numbers, 24 h after maximal eccentric knee extensor exercise, is blunted in older men. Muscle biopsies were obtained from the vastus lateralis of 10 young (23–35 years) and 9 older (60–75 years) men. Satellite cells were identified immunohistochemically using an antibody to neural cell adhesion molecule. After 92 maximal eccentric contractions, the mean number of satellite cells per muscle fiber increased to a greater extent among the young men (141%; P < 0.001) than older men (51%; P = 0.002) from preexercise levels. Similar results were obtained when satellite cells were expressed as a proportion of all sublaminar nuclei. We conclude that a single bout of maximal eccentric exercise increases satellite cell numbers in both age groups, with a significantly greater response among the young men. These data suggest that age‐related changes in satellite cell recruitment may contribute to muscle regeneration deficits among the elderly. Muscle Nerve 2006
Creativity, celebration and play at the Bauhaus, Berlin, 1920: lessons from history for contemporary marketers and arts organizations
Authors: Minahan Stella , Härtel Charmine
Published: November 2005

Organizations can be seen as rigid, rewarding conformity not creativity. Managing the creative team or individual can be challenging. This paper contributes to this special issue of the International Journal of Nonprofit and Voluntary Sector Marketing by addressing ways to manage creativity in an organization, as well as to creatively market the organization. It presents a case study of an organization based in Germany in the 1920s, the Bauhaus. This art and craft organization achieved extraordinary creative output in just over a decade of operation, during the devastation of post World War I. This paper demonstrates how its leader managed the creativity of the staff and students and creatively marketed the organization despite a lack of funds and the desperate shortage of resources. The Bauhaus provides a key lesson for contemporary marketers and managers in developing the characteristics of organizations that nurture creativity and the creative individual.

Copyright © 2005 John Wiley & Sons, Ltd.
Distribution of degrees of polymerization in statistically branched polymers with tetrafunctional branch points: model calculations
Authors: Netopilík Miloš , Kratochvíl Pavel
Published: November 2005

Stockmayer's classical theory of statistical branching of polymers, as modified by Thurmond and Zimm, and subsequently by Kilb, has been used to describe the evolution of the distribution of the degrees of polymerization with conversion up to the gel point in the copolymerization of a vinyl monomer with a small amount of a divinyl monomer. The weight fractions of molecules with a particular number of branch points per molecule, the averages of the degrees of polymerization of these molecules, and some other characteristics were calculated as functions of a complex variable—the branching parameter γ, including the composition of the monomer mixture, relative reactivities of the individual types of double bonds, and conversion. From these calculations, a few general conclusions on the behaviour of the model system can be drawn. The conclusions are likely to be qualitatively valid also for systems not strictly conforming to the model. Copyright © 2005 Society of Chemical Industry
Precise synthesis of porphyrin array scaffolding polyisocyanides
Authors: Takei Fumie , Kodama Daisuke , Nakamura Sugiko , Onitsuka Kiyotaka , Takahashi Shigetoshi
Published: November 2005

Aryl isocyanides bearing free‐base and metallo‐porphyrins were prepared and polymerized with a Pd–Pt μ‐ethynediyl complex as the initiator to give polymers with narrow polydispersity indices. The molecular weights of the resulting polymers were precisely controlled by the initial feed ratio of the porphyrin monomer to the initiator. The UV–VIS spectra suggested that the porphyrin pendants are regularly arranged to form stacked columns. Metallo‐porphyrin polymers were also prepared by reacting free‐base porphyrin polymers with metal salts. The successive reactions of free‐base and zinc‐porphyrin monomers resulted in the formation of diblock polymers. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 585–595, 2006
Synthesis and characterization of model 3‐miktoarm star copolymers of poly(dimethylsiloxane) and poly(2‐vinylpyridine)
Authors: Fragouli Panagiota G. , Iatrou Hermis , Hadjichristidis Nikos , Sakurai Takuro , Hirao Akira
Published: November 2005

3‐Miktoarm star copolymers, 3μ‐D2V, with two poly(dimethylsiloxane) (PDMS) and one poly(2‐vinylpyridine) (P2VP) arm, were synthesized by using anionic polymerization–high vacuum techniques and (chloromethylphenylethyl)methyl dichlorosilane, heterofunctional linking agent, with two SiCl groups and one CH2Cl group. The synthetic strategy involves the selective reaction of the two SiCl groups with PDMSOLi living chains, followed by reaction of the remaining chloromethyl group with P2VPLi. Combined molecular characterization results (size exclusion chromatography, membrane osmometry, and 1H NMR spectroscopy) revealed a high degree of structural and compositional homogeneity. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 614–619, 2006
Synthesis and characterization of polyurethanes from epoxidized methyl oleate based polyether polyols as renewable resources
Authors: Lligadas G. , Ronda J. C. , Galià M. , Biermann U. , Metzger J. O.
Published: November 2005

Oligomeric polyether polyols were obtained through the acid‐catalyzed ring‐opening polymerization of epoxidized methyl oleate and the subsequent partial reduction of ester groups to give primary alcohols. The oligomers were characterized with titration, spectroscopic techniques (Fourier transform infrared and nuclear magnetic resonance), matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry, size exclusion chromatography, and differential scanning calorimetry. Depending on the degree of reduction, polyols of different hydroxyl content values were obtained and were reacted with 4,4′‐methylenebis(phenyl isocyanate) to yield polyurethanes. These materials, which were characterized by differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical thermal analysis, could behave as hard rubbers or rigid plastics. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 634–645, 2006
Large‐scale survey for potentially targetable indels in bacterial and protozoan proteins
Authors: Cherkasov Artem , Lee Shang‐Jung , Nandan Devki , Reiner Neil E.
Published: November 2005

Our previous results demonstrated that some essential, housekeeping proteins from pathogenic microorganisms may contain sizable insertions–deletions in their sequences (compared to close human homologs) that can be responsible for unexpected virulence properties. For example, we found that indel‐bearing elongation factor‐1α from several pathogenic protozoa can activate a human tyrosine phosphatase SHP‐1 leading to deactivation of macrophages. On the one hand, these findings allowed development of a strategy for targeting some indel‐containing pathogen proteins that have similar human counterparts. On the other hand, the results raised numerous questions regarding the nature and implications of sequence indels in pathogen proteins. In the present study, we conducted a large‐scale survey of indels in proteins from 136 bacterial and protozoan genomes. It has been established that sizable insertions and deletions occur in approximately 5–10% of bacterial proteins with close human homologs, while proteins from the protozoan pathogens such as Trypanosoma cruzi, Plasmodium falciparum, and Leishmania donovani exhibit elevated indel content that can reach up to 25%. The finding suggested that the occurrence of sequence indels may be involved in the evolution of pathogenic mechanisms in these protozoa. Proteins 2006. © 2005 Wiley‐Liss, Inc.
Modeling truncated hemoglobin vibrational dynamics
Authors: Marsella Luca
Published: November 2005

We present a study on the near equilibrium dynamics of two small proteins in the family of truncated hemoglobins, developed under the framework of a Gaussian network approach. Effective beta carbon atoms are taken into account besides Cαs for all residues but glycines in the coarse‐graining procedure, without leading to an increase in the degrees of freedom (β Gaussian Model). Normalized covariance matrix and deformation along slowest modes with collective character are analyzed, pointing out anticorrelations between functionally relevant sites for the proteins under study. In particular, we underline the functional motions of an extended tunnel‐cavity system running inside the protein matrix, which provide a pathway for small ligands binding with the iron in the heme group. We give a rough estimate of the order of magnitude of the relaxation times of the slowest two overdamped modes and compare results with previous studies on globins. Proteins 2006. © 2005 Wiley‐Liss, Inc.
The thermal adaptation of the nitrogenase Fe protein from thermophilic Methanobacter thermoautotrophicus
Authors: Sen Sanchayita , Peters John W.
Published: November 2005

The nitrogenase Fe protein is a key component of the biochemical machinery responsible for the process of biological nitrogen fixation. The Fe protein is a member of a class of nucleotide‐binding proteins that couple the binding and hydrolysis of nucleoside triphosphates to conformational changes. The nucleotide‐dependent conformational changes modulate the formation of a macromolecular complex, and some members of the class include Gα, EF‐Tu, and myosin. The members of this class are highly interesting model systems for the analysis of aspects of thermal adaptability, since their mechanisms involve protein conformational change and protein–protein interactions. In this study, we have used our extensive knowledge of the structure of the Azotobacter vinelandii nitrogenase Fe protein in multiple structural conformations, and standard homology modeling approaches have been used to generate reliable models of the Fe protein from thermophilic Methanobacter thermoautotrophicus in the analogous structural conformations. The resulting structural comparison reveals that thermal adaptation of the M. thermoautotrophicus Fe protein is conferred by a number of factors, including increased structural rigidity that results from various structural changes within the protein interior. The analysis of hypothetical docking models and nitrogenase complex structures provides insights into the thermal adaptation of the protein–protein interactions that support macromolecular complex formation and catalysis at higher temperatures. Proteins 2006. © 2005 Wiley‐Liss, Inc.
Side‐chain entropy effects on protein secondary structure formation
Authors: Chellgren Brian W. , Creamer Trevor P.
Published: November 2005

Loss of conformational entropy is one of the primary factors opposing protein folding. Both the backbone and side‐chain of each residue in a protein will have their freedom of motion restricted in the final folded structure. The type of secondary structure of which a residue is part will have a significant impact on how much side‐chain entropy is lost. Side‐chain conformational entropies have previously been determined for folded proteins, simple models of unfolded proteins, α‐helices, and a dipeptide model for β‐strands, but not for polyproline II (PII) helices. In this work, we present side‐chain conformational estimates for the three regular secondary structure types: α‐helices, β‐strands, and PII helices. Entropies are estimated from Monte Carlo computer simulations. β‐Strands are modeled as two structures, parallel and antiparallel β‐strands. Our data indicate that restraining a residue to the PII helix or antiparallel β‐strand conformations results in side‐chain entropies equal to or higher than those obtained by restraining residues to the parallel β‐strand conformation. Side‐chains in the α‐helix conformation have the lowest side‐chain entropies. The observation that extended structures retain the most side‐chain entropy suggests that such structures would be entropically favored in unfolded proteins under folding conditions. Our data indicate that the PII helix conformation would be somewhat favored over β‐strand conformations, with antiparallel β‐strand favored over parallel. Notably, our data imply that, under some circumstances, residues may gain side‐chain entropy upon folding. Implications of our findings for protein folding and unfolded states are discussed. Proteins 2006. © 2005 Wiley‐Liss, Inc.
Will my protein crystallize? A sequence‐based predictor
Authors: Smialowski Pawel , Schmidt Thorsten , Cox Jürgen , Kirschner Andreas , Frishman Dmitrij
Published: November 2005

We propose a machine‐learning approach to sequence‐based prediction of protein crystallizability in which we exploit subtle differences between proteins whose structures were solved by X‐ray analysis [or by both X‐ray and nuclear magnetic resonance (NMR) spectroscopy] and those proteins whose structures were solved by NMR spectroscopy alone. Because the NMR technique is usually applied on relatively small proteins, sequence length distributions of the X‐ray and NMR datasets were adjusted to avoid predictions biased by protein size. As feature space for classification, we used frequencies of mono‐, di‐, and tripeptides represented by the original 20‐letter amino acid alphabet as well as by several reduced alphabets in which amino acids were grouped by their physicochemical and structural properties. The classification algorithm was constructed as a two‐layered structure in which the output of primary support vector machine classifiers operating on peptide frequencies was combined by a second‐level Naive Bayes classifier. Due to the application of metamethods for cost sensitivity, our method is able to handle real datasets with unbalanced class representation. An overall prediction accuracy of 67% [65% on the positive (crystallizable) and 69% on the negative (noncrystallizable) class] was achieved in a 10‐fold cross‐validation experiment, indicating that the proposed algorithm may be a valuable tool for more efficient target selection in structural genomics. A Web server for protein crystallizability prediction called SECRET is available athttp://webclu.bio.wzw.tum.de:8080/secret. Proteins 2006. © 2005 Wiley‐Liss, Inc.
Hierarchy of equations in the generalized density functional theory
Authors: Nagy Á.
Published: November 2005

Functional relations and equations of hierarchy in the generalized density functional theory (DFT) are derived from coordinate scaling and adiabatic connection. Local and nonlocal solutions for the noninteracting kinetic energy, exchange energy, correlation energy, and the kinetic energy correction functionals are presented. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Treating hydrogen bonding in ab initio calculation of biopolymers
Authors: Mei Ye , Wu Emilia L. , Han K.L. , Zhang J.Z.H.
Published: November 2005

We present a general scheme to treat backbone hydrogen bonding in protein using the molecular fractionation with conjugate caps (MFCC) approach. In this approach, molecular caps are employed to mimic the hydrogen bonding environment of protein fragments that are calculated individually. Using this scheme in the MFCC method, we carried out explicit numerical calculations for a number of secondary structures of proteins, including the α‐helix and β‐sheet. The calculated electron densities, electrostatic potentials, and dipole moment are compared with those from the standard full system ab initio calculations. The result shows that the current treatment using the hydrogen bond cap gives an accurate description of the hydrogen bonding effect and accurate dipole moment. In contrast, calculation using the standard force field (FF) approach gives dipole moments that are in huge error (i.e., significantly smaller) than the quantum result for helix structures due to the lack of polarization effect with fixed partial charges. The present study demonstrates that the MFCC approach can quantitatively describe hydrogen bonding in practical ab initio calculation of proteins. Our result also underscores the importance of the polarization effect in backbone hydrogen bonding of protein. This could have significant implication in studying the electrostatic interaction of proteins, such as protein solvation. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Computational study of maleamic acid cyclodehydration with acetic anhydride
Authors: Constantinescu Mircea , Ivanov Daniela
Published: November 2005

The reaction mechanisms of N‐substituted maleamic acids (MA) cyclodehydration (CDH) to the corresponding maleimides (M) and isomaleimides (IM) and IM rearrangement to M were studied by the PM3 Hamiltonian with charge model 1 (CM1P) of the AMSOL computational method with solvation effect in order to establish the most probable pathways. CDH was considered in the presence of acetic anhydride in the presence of an acetate anion or triethylamine as the dehydrating agent in CH2Cl2 as the solvent. In the first step, our computational results supported carboxylic proton losses, provided by a nucleophilic center on the dehydrating agent. In the next step, maleamic acid anion could either add a molecule of a dehydrating agent (path A) or cyclicize (path B). Our results indicate the path B to require more energy than path A, so path B is considered less likely to occur. The formation (path A) of an anion complex I2 between the anion of MA and the dehydration agent was supported as well as acetate anion loss to form the neutral mixed anhydride I3. The ring closure to M or IM occurs only after I3 amide proton loss, meaning that the dehydrating agent necessitate another nucleophilic center. The cyclization of I4 anion over amide nitrogen or oxygen to the reaction outcome depends on the electronic effect of amide nitrogen substituent. The same results were obtained studying CDH of N‐substituted ophthalmic acids with acetic anhydride and for MA with N,N′‐dicyclohexylcarbodiimide as dehydrating agent, in the same solvent. In such circumstances, one can consider them the common features of a general CDH reaction mechanism of MA. Our computational results found the IM to M rearrangement to correspond to the reversible final path of synthesis mechanism although the other investigators considered it to take place under a different reaction. They also supported the importance of the acetate anion in both cyclization and rearrangement mechanisms; the presence of tertiary amine blocks the acetic acid formed during reaction, determines I3 amide proton loss and prevents rearrangement. The theoretical conclusions are consistent with the experimental results. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
New classes of orthogonal polynomials
Authors: Srivastava Vipin , Ramesh Naidu A.
Published: November 2005

We show that two new classes of orthogonal polynomials can be derived by applying two orthogonalization procedures due to Löwdin to a set of monomials. They are new in that they possess novel properties in terms of their inner products with the monomials. Each class comprises sets of orthogonal polynomials that satisfy orthogonality conditions with respect to a weight function on a certain interval. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006