bluuebunny/crossref_metadata_2025 huggingface dataset:
Muscle sparing‐2 transverse rectus abdominis musculocutaneous flap for breast reconstruction: A comparison with deep inferior epigastric perforator flap
Authors: Takeishi Meisei , Fujimoto Masashi , Ishida Katuhiro , Makino Yojiro
Published: October 2008

Breast reconstruction using free transverse rectus abdominis musculocutaneous (TRAM) flap can be divided into 4 muscle‐sparing (MS) types: conventional TRAM flap containing full width muscle as MS‐0, while deep inferior epigastric perforator (DIEP) flap containing absolutely no muscle as MS‐3. We include only the muscle portion between the medial row and lateral row perforator vessels in TRAM flap, which is designated as MS‐2. Between October 1999 and April 2006, the same surgeon performed 82 breast constructions using MS‐2 free TRAM flaps in 79 patients. All the flaps survived. Postoperative complications included partial fat necrosis in 8 cases, all corresponding to zone IV or zone II. Bulging of donor site occurred in 5 patients, 4 of whom were obese and 1 had bilateral flap harvest. Compared with our own reconstructions using DIEP flap (30 cases), there were no significant differences in operative time and blood loss between the two techniques. In conclusion, MS‐2 free TRAM flap is a useful technique for breast construction considering the easy surgical techniques, length of the vascular pedicle that can be harvested, and the degree of freedom of the flap. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Index finger salvage with replantation and revascularization: Revisiting conventional wisdom
Authors: Buntic Rudolf F. , Brooks Darrell , Buncke Gregory M.
Published: October 2008

Replantation/revascularization of severely injured single digits is controversial, especially at the index position. Conventional wisdom is that these digits if salvaged will ultimately worsen residual hand function and they should be amputated. Twenty‐eight cases of such index salvages were reviewed to test this hypothesis. Five cases involved children and were excluded. Twenty‐three replants/revascularizations survived (100%). Total active motion was 170° in zone 1, and 133° for zone 2 injuries. Patient satisfaction was high in all cases. In selected cases, salvage of severely injured and amputated index fingers has the potential for satisfying survival and functional results and dogmatic treatment with completion amputation should be avoided. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Use of circular external fixation to maintain foot position during free tissue transfer to the foot and ankle
Authors: Lowenberg David W. , Sadeghi Cameron , Brooks Darrell , Buncke Gregory M. , Buntic Rudolf F.
Published: October 2008

Limb salvage techniques of traumatized extremities using free‐tissue transfer and microsurgical techniques have become standard reconstructive methods. To our knowledge there is no published data on the incidence or likelihood of equinus following free tissue transfer about the ankle, although in our experience we have perceived an unacceptable incidence of equinus following free tissue transfers about the ankle and therefore initiated prophylactic ring fixation across the ankle. Fourteen patients were placed in circular external fixation spanning the ankle at the time of free tissue transfer for a mean of 12 weeks (Median 7 weeks, Range 6–28 weeks). The results were evaluated using the degree of active ankle dorsiflexion and return to independent ambulation. Six patients had excellent results with active ankle dorsiflexion beyond neutral, and four patients had good results with neutral ankle alignment that did not require further intervention. All patients saved their limb and returned to independent ambulation. When performing free tissue transfer about the ankle, temporary spanning with a circular fixator is effective in preventing equinus deformity and provides a stable mechanical construct protecting the flap. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Management of exposed total knee prostheses with microvascular tissue transfer
Authors: Cetrulo Curtis L. , Shiba Travis , Friel Michael T. , Davis Brian , Buntic Rudolph F. , Buncke Gregory M. , Brooks Darrell
Published: October 2008

Introduction: Exposure of a knee endoprosthesis represents a limb‐threatening condition, requiring long‐term antibiosis, irrigation, and serial debridement to avoid knee arthrodesis or amputation. Although traditional orthopedic surgical doctrine mandates removal of exposed hardware under a dehisced wound, salvage of exposed prostheses using local muscle flap coverage has been reported. However, the complex three‐dimensional geometry of the soft tissue surrounding the knee as well as the requirement for sustained local tissue levels of antibiotics to re‐sterilize the hardware suggest that microvascular tissue transfer may constitute an advantageous means of wound coverage, increasing both limb and prosthesis salvage rates. We report our experience with free tissue transfer reconstruction of these complex wounds. Methods: We treated 11 complex wounds with exposed total knee arthroplasty prostheses with free tissue transfer. Three of 11 patients had failed previous local muscular rotation flap coverage. Five latissimus dorsi muscle flaps and 6 rectus abdominis muscle flaps were used in our series. Wounds were closed after aggressive surgical debridement, antibiotic irrigation, and intravenous antibiosis. Results: Eleven of 11 free flaps were successful (100%), and we achieved limb salvage in 11/11 limbs (100%) and prosthesis salvage in 10/11 knees (91%), with one prosthesis removed at an outside facility followed by knee arthrodesis. Conclusion: The advantages of microvascular tissue transfer are well suited to the treatment of exposed knee endoprostheses. The reliable rectus and latissimus flaps provide robust local perfusion to the wound, fill complex three‐dimensional contour defects around knee implants, and lead to a high rate of salvage of both limbs and prostheses. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
A20 deletion is associated with copy number gain at the TNFA/B/C locus and occurs preferentially in translocation‐negative MALT lymphoma of the ocular adnexa and salivary glands
Authors: Chanudet E , Ye H , Ferry J , Bacon CM , Adam P , Müller‐Hermelink HK , Radford J , Pileri SA , Ichimura K , Collins VP , Hamoudi RA , Nicholson AG , Wotherspoon AC , Isaacson PG , Du MQ
Published: October 2008

The genetic basis of MALT lymphoma is largely unknown. Characteristic chromosomal translocations are frequently associated with gastric and pulmonary cases, but are rare at other sites. We compared the genetic profiles of 33 ocular adnexal and 25 pulmonary MALT lymphomas by 1 Mb array–comparative genomic hybridization (CGH) and revealed recurrent 6q23 losses and 6p21.2–6p22.1 gains exclusive to ocular cases. High‐resolution chromosome 6 tile‐path array–CGH identified NF‐κB inhibitor A20 as the target of 6q23.3 deletion and TNFA/B/C locus as a putative target of 6p21.2–22.1 gain. Interphase fluorescence in situ hybridization showed that A20 deletion occurred in MALT lymphoma of the ocular adnexa (8/42 = 19%), salivary gland (2/24 = 8%), thyroid (1/9 = 11%) and liver (1/2), but not in the lung (26), stomach (45) and skin (13). Homozygous deletion was observed in three cases. A20 deletion and TNFA/B/C gain were significantly associated (p < 0.001) and exclusively found in cases without characteristic translocation. In ocular cases, A20 deletion was associated with concurrent involvement of different adnexal tissues or extraocular sites at diagnosis (p = 0.007), a higher proportion of relapse (67% versus 37%) and a shorter relapse‐free survival (p = 0.033). A20 deletion and gain at TNFA/B/C locus may thus play an important role in the development of translocation‐negative MALT lymphoma. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Effect of short‐ and long‐term play therapy services on teacher–child relationship stress
Authors: Ray Dee C. , Henson Robin K. , Schottelkorb April A. , Brown April Garofano , Muro Joel
Published: October 2008

The purpose of the present study was to explore the effect of both short‐ and long term Child‐Centered Play Therapy on teacher–student relationship stress. Teachers identified 58 students exhibiting emotional and behavioral difficulties who were randomly assigned to one of two treatment groups. Students in the short‐term intensive play therapy group participated in 16 sessions of play therapy over 8 weeks, and students in the long‐term play therapy group participated in 16 sessions over 16 weeks. Results indicated that both intervention groups demonstrated significant improvement in teacher–student relationship stress from pre‐ to posttest. Post hoc analyses indicated that the short‐term intensive intervention demonstrated statistical significance and larger effect sizes in overall total stress, teacher characteristics, and student characteristics. © 2008 Wiley Periodicals, Inc.
Design, synthesis, and characterization of a combined main‐chain/side‐chain liquid crystalline polymer based on mesogen‐jacketed liquid crystal polymer via atom transfer radical polymerization
Authors: Xie Helou , Hu Tianhui , Zhang Xuefei , Zhang Hailaing , Chen Erqiang , Zhou Qifeng
Published: October 2008

A novel combined main‐chain/side‐chain liquid crystalline polymer based on mesogen‐jacketed liquid crystal polymers (MJLCPs) containing two biphenyls per mesogenic core of MJLCPs main chain, poly(2,5‐bis{[6‐(4‐butoxy‐4′‐oxy‐biphenyl)hexyl]oxycarbonyl}styrene) (P1–P8) was successfully synthesized via atom transfer radical polymerization (ATRP). The chemical structure of the monomer was confirmed by elemental analysis, 1H NMR, and 13C NMR. The molecular characterizations of the polymer with different molecular weights (P1–P8) were performed with 1H NMR, gel permeation chromatography (GPC), and thermogravimetric analysis (TGA). Their phase transitions and liquid‐crystalline behaviors of the polymers were investigated by differential scanning calorimetry (DSC) and polarized optical microscope (POM). We found that the polymers P1–P8 exhibited similar behavior with three different liquid crystalline phases upon heating to or cooling in addition to isotropic state, which should be related to the complex liquid crystal property of the side‐chain and the main‐chain. Moreover, the transition temperatures of liquid crystalline phases of P1–P8 are found to be dependent on the molecular weight. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7310–7320, 2008
Influence of adjusted hydrophilic–hydrophobic lengths in sulfonated multiblock copoly(ether sulfone) membranes for fuel cell application
Authors: Nakabayashi Kazuhiro , Matsumoto Kazuya , Higashihara Tomoya , Ueda Mitsuru
Published: October 2008

Sulfonated multiblock copoly(ether sulfone)s applicable to proton exchange membrane fuel cells (PEMFCs) were synthesized by the coupling reaction of the hydroxyl‐terminated hydrophilic and hydrophobic oligomers with different lengths in the presence of highly reactive decafluorobiphenyl (DFB) as a chain extender to investigate the influence of each length on the membranes' properties, such as water uptake, proton conductivity, and morphology. Multiblock copolymers with high molecular weights (Mn > 50,000, Mw > 150,000) were obtained under mild reaction conditions. The resulting membranes demonstrated good oxidative stability for hot Fenton's reagent and maintained high water uptake (7.3–18.7 wt %) under a low relative humidity (50% RH). Proton conductivity of all membranes at 80 °C and 95% RH was higher than that of Nafion 117 membrane, and good proton conductivity of 7.0 × 10−3 S/cm was obtained at 80 °C and 50% RH by optimizing the oligomer lengths. The surface morphology of the membranes was investigated by tapping mode atomic force microscopy (AFM), which showed that the multiblock copolymer membranes had a clearer surface hydrophilic/hydrophobic‐separated structure than that of the random copolymer, and contributed to good and effective proton conduction. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7332–7341, 2008
Thiophene–phenylene/naphthalene‐based step‐ladder copolymers
Authors: Bünnagel Torsten W. , Nehls Benjamin S. , Galbrecht Frank , Schottler Kristina , Kudla Christof J. , Volk Markus , Pina João , de Melo João S. Seixas , Burrows Hugh D. , SCherf Ullrich
Published: October 2008

A series of step‐ladder copolymers based on thiophene–phenylene–thiophene SL1‐SL3 and thiophene–naphthylene–thiophene SL4 repeat units with varying lengths of the oligothiophene segment has been designed and synthesized via a microwave‐assisted Stille‐type cross‐coupling reaction followed by a polymer‐analogous cyclization reaction. The optical properties of the step‐ladder copolymers have been investigated in detail, in particular at low temperature and in the solid‐state. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7342–7353, 2008
Novel thermally stable triarylamine‐containing aromatic polyamides bearing anthrylamine chromophores for highly efficient green‐light‐emitting materials
Authors: Yen Hung‐ju , Liou Guey‐Sheng
Published: October 2008

A series of novel polyamides with pendent anthrylamine units were prepared via the direct phosphorylation polycondensation from various diamines and the anthrylamine‐based aromatic dicarboxylic acid, 9‐[N,N‐di(4‐carboxyphenyl)amino]anthracene (4). The aromatic polyamides had useful levels of thermal stability associated with relatively high softening temperatures (Ts) (290–300 °C), 10% weight‐loss temperatures (Td10) nearly in excess of 550 °C, and char yields at 800 °C in nitrogen higher than 60%. These aromatic polyamides I exhibited highly photoluminescence quantum yield in NMP solution ranges from 55% for Ia to 74% for Ie due to the introduction of anthrylamine chromophores. Cyclic voltammograms of the polyamide films cast onto an indium‐tin oxide (ITO)‐coated glass substrate exhibited one oxidation and reduction couples (Eonset) around 1.10 and −1.50 V versus Ag/AgCl in acetonitrile (CH3CN) and DMF solutions, respectively. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7354–7368, 2008
Polymerization of methyl acrylate mediated by copper(0)/Me6‐TREN in hydrophobic media enhanced by phenols; Single electron transfer‐living radical polymerization
Authors: Wright Peter M. , Mantovani Giuseppe , Haddleton David M.
Published: October 2008

Phenol has been used as an additive to enhance the rate of SET‐LRP in toluene at ambient temperature. A direct relationship between reaction time and amount of phenol added has been found with the optimum amount being ∼ 20 equiv. of phenol with respect to initiator. Polymerization of methyl acrylate (MA) has been carried out in the presence of varying amounts of phenol and the rate of polymerization depends on the concentration of phenol relative to initiator. With a 20‐fold excess 93% conversion is observed after 218 min (PDI = 1.06, Mn = 11,500 g mol−1) when compared with 80% conversion with a 5‐fold excess (PDI = 1.21, Mn = 5310 g mol−1). When nonsterically hindered phenols are employed in a 20 molar excess with respect to the initiator the polymerizations have good linear first‐order kinetics and give polymers with PDI between 1.06 and 1.16. When a highly hindered phenol is employed there is a significant induction period prior to polymerization taking place which is similar to when using no phenol. Less hindered phenols accelerated the polymerization when compared with polymerizations with no added phenol. Increasing steric hindrance at the OH prevents this coordination which indicates that the role of phenol is different with either copper(0) or copper(I). Aliphatic and aromatic esters and amides were used successfully as initiators giving polymers with Mn close to that predicted at ∼ 10,000 g mol−1 and PDI typically less than 1.10. An induction period is observed in most cases which can be removed by a pre‐equilibrium step before the addition of monomer. This results in excellent first‐order kinetics being observed in the polymerization of MA in toluene solution (50 vol %). Here Cu(0) (powder)/Me6‐TREN with 20 equiv. of phenol and all of the reactants, except the monomer, were added to the reaction flask and stirred for 45 min at 25 °C. The structure of the polymer is shown by MALDI TOF MS to contain bromide chain ends derived from the alkyl bromide initiator. The retention of this end group is consistent with living radical polymerization. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7376–7385, 2008
Polymer functionalization by free radical addition to alkynes
Authors: Wu Wei , Parent J. Scott
Published: October 2008

A new chemical modification of saturated polymers involving free radical addition to mono‐substituted alkynes is presented and examined in terms of reaction yield, graft structure, and changes to molecular weight. Solvent‐free, peroxide‐initiated reactions of ethyl propiolate and poly(ethylene oxide) provide good yields of ethyl (2‐E,Z)‐3‐alkylacrylates, whereas less efficient hydrogen atom donation by polyethylene impacts negatively on reaction yields and encourages alkyne oligomerization. Model compounds are used to characterize alkyne grafting products, and to probe the relationship between reagent properties, reaction yields, and product structures. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7386–7394, 2008
A new approach for controlling birefringent property of cyclic olefin copolymers
Authors: Ban Hoang The , Hagihara Hideaki , Nishii Kei , Tsunogae Yasuo , Nojima Shuichi , Shiono Takeshi
Published: October 2008

This article reports an original method to control the birefringent property of the cyclic olefin copolymer, which has been recently commercialized as a new type of optical resins, via introduction of a third monomer that possesses a negative birefringence into the cyclic olefin copolymer that exhibits an inherently positive birefringence. The mutual compensation between these opposite‐sign birefringences effectively reduced the birefringent magnitude of the corresponding terpolymer. In fact, terpolymerization of norbornene (N), ethylene (E), and styrene (S), in which S exhibits a negative birefringence regarding to the positive birefringence of the NE copolymer was successfully prepared using fluorenylamidodimethyltitanium‐based catalyst, yielding NES terpolymers with controllable birefringent property. Especially, when the S content in the NES terpolymer was controlled at optimum values, it is possible to synthesize a new type of the cyclic olefin copolymer that exhibits an extremely low birefringent magnitude close to zero regardless of high degrees of chain orientation. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7395–7400, 2008
Efficient tuning nonlinear optical properties: Synthesis and characterization of a series of novel poly(aryleneethynylene)s co‐containing BODIPY
Authors: Zhu Mei , Jiang Li , Yuan Mingjian , Liu Xiaofeng , Ouyang Canbin , Zheng Haiyan , Yin Xiaodong , Zuo Zicheng , Liu Huibiao , Li Yuliang
Published: October 2008

A series of novel conjugated poly(aryleneethynylene)s (PAEs) co‐containing BODIPY have been synthesized and characterized, and their third‐order nonlinear optical properties were studied using the Z‐scan technique. Interestingly, by introducing the BODIPY skeleton into the PAE backbone, the polymers showed that their nonlinear optical properties were dependent on the BODIPY component. From poly‐4 to poly‐1, the third‐order nonlinear optical properties of the polymers enhanced regularly with the increase of the BODIPY component of the copolymers, indicating that the BODIPY component played decisive roles in enhancing the nonlinear optical properties. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7401–7410, 2008
Copolymerization of ethylene and norbornene using cyclopentadienylzirconium trichloride activated by isobutyl‐modified methylaluminoxane
Authors: Nishizawa Osamu , Misaka Hideki , Sakai Ryosuke , Kakuchi Toyoji , Satoh Toshifumi
Published: October 2008

The copolymerization of ethylene (E) and norbornene (NB) was investigated using the commercially available and inexpensive catalyst system, cyclopentadienylzirconium trichloride (CpZrCl3)/isobutyl‐modified methylaluminoxane (MMAO), at a moderate polymerization temperature in toluene. For the CpZrCl3 catalyst system activated by aluminoxane with a 40 mol % methyl group and a 60 mol % isobutyl group (MMAO), the quantities of the charged NB and the polymerization temperature significantly affected the molecular weights, polydispersities, and NB contents of the obtained copolymers and the copolymerization activities in all the experiments. As the charged NB increased and thereby the NB/E molar ratio increased, the NB content in the copolymer increased and reached a maximum value of 71 mol %. The CpZrCl3/MMAO ([Al]/[Zr] = 1000) catalyst system with the [NB] of 2.77 mol L−1 and ethylene of 0.70 MPa at 50 °C showed the highest activity of 1690 kg molZr−1 h−1 and molecular weight of 21,100 g mol−1. The 13C NMR analysis showed that the CpZrCl3/MMAO catalyst system produced the E‐NB random copolymer with a number of NB homosequences such as the NN dyad and NNN triad. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7411–7418, 2008
Highly soluble green‐emitting Ir(III) complexes with 9‐(6‐phenyl‐pyridin‐3‐ylmethyl)‐9H‐carbazole ligands and their application to polymer light‐emitting diodes
Authors: Cho Min Ju , Kim Jae Il , Hong Chang Seop , Kim Young Min , Park Young Wook , Ju Byeong‐Kwon , Choi Dong Hoon
Published: October 2008

Highly organic soluble Ir(III) complexes with 9‐(6‐phenyl‐pyridin‐3‐ylmethyl)‐9H‐carbazole were simply synthesized, and the solubility of the new complex was significantly improved when compared with the conventional green‐emitting Ir(ppy)3. Since a carbazole group is tethered through a nonconjugated methylene spacer, the photophysical properties of new complexes are almost identical with those of conventional Ir(ppy)3. The pure complexes were utilized to prepare electrophosphorescent polymer light‐emitting diodes (PLEDs). The device performances were observed to be relatively better or comparable with those of Ir(ppy)3 based poly(N‐vinylcarbazole) systems. The integration of rigid hole‐transporting carbazole and phosphorescent complex provides a new route to design highly efficient solution‐processable complex for electrophosphorescent PLED applications. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7419–7428, 2008
Dispersion polymerization of vinyl monomers in supercritical carbon dioxide in the presence of drug molecules: A one‐pot route for the preparation of controlled delivery systems
Authors: Galia Alessandro , Scialdone Onofrio , Ferraro Gianpiero , Filardo Giuseppe
Published: October 2008

The polymerization of 1‐vinyl‐2‐pyrrolidone in supercritical carbon dioxide in the presence of ibuprofen as a model drug was investigated as a new one‐pot process for the preparation of polymer‐based drug delivery systems (DDSs). The composites were prepared at 65 °C and P = 31–42 MPa by changing the initial concentration of the drug and the concentration of a crosslinking agent and that of a hydrophobic comonomer. The effects of these parameters on the performances of the polymerization and on the in vitro release kinetics of ibuprofen were studied. In all the experiments, part of the drug was entrapped inside the polymer particles and dissolved more slowly with respect to the pure compound. Copolymerization with methyl methacrylate was the most effective route to obtain a DDS with sustained temporal release of the drug molecule. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7429–7446, 2008
Epoxy/amine‐functionalized short‐length vapor‐grown carbon nanofiber composites
Authors: Ahn Soo‐Na , Lee Hwa‐Jeong , Kim Bang‐Jun , Tan Loon‐Seng , Baek Jong‐Beom
Published: October 2008

Short length vapor‐grown carbon nanofibers (VGCNFs) were functionalized with 4‐aminobenzoic acid in polyphosphoric acid/phosphorous phentoxide medium via “direct” Friedel‐Crafts acylation reaction to afford aminobenzoyl‐functionalized VGCNFs (AF‐VGCNFs). The AF‐VGCNFs as a cocuring agent were mixed with epoxy resin by simple mechanical stirring in methanol which was added to help efficient mixing. After evaporation of methanol, 4,4′‐methylenedianiline as a curing agent was added to the mixture, which was then cured at elevated temperatures. The resultant composites displayed uniform dispersion of AF‐VGCNFs into cured epoxy matrix. During curing process, the amine functionalities on AF‐VGCNF together with 4,4′‐methylenedianiline were expected to be involved in covalent attachment to the epoxy resin. As a result, both tensile modulus and strength of the composites were improved when compared with those of pure epoxy resin. Thus, the AF‐VGCNFs play a role as an outstanding functional additive, which could resolve both dispersion and interfacial adhesion issues at the same time by functionalization of VGCNFs and covalent bonding between the additive and matrix, respectively. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7473–7482, 2008
Micelle‐to‐vesicle transition induced by oligonucleotide in SDS/DEAB mixed system with a net negative charge
Authors: Guo Xia , Li Hua , Gong Zhiyun , Zhang Fengmin , Zheng Songyun , Guo Rong
Published: October 2008

Sodium dodecyl sulfate (SDS)/dodecyl triethyl ammonium bromide (DEAB) mixed micelles (with SDS in excess) can transform to vesicles only when the temperature is higher than a critical value. In this study, we report for the first time that oligonucleotide can decrease the critical temperature to a much lower value and, hence, induce micelle‐to‐vesicle transition. The facilitation efficiency of oligonucleotide on vesicle formation is closely dependent on its size and base composition. Moreover, the SDS/DEAB/oligonucleotide vesicles are negatively charged and the hydrophobic interaction between oligonucleotide and SDS/DEAB mixed micelles is the driving force. As, so far, the report about the facilitation effect of oligonucleotide and DNA on vesicle formation is very limited, this study may provide some helpful information for the application of DNA/amphiphile system. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7491–7504, 2008
Photodegradation‐induced photoluminescence behaviors of π‐conjugated polymers upon the doping of organometallic triplet emitters
Authors: Chang Jungyun , Yu Young‐Jun , Na Jung Hoon , An Jongdeok , Im Chan , Choi Dong‐Hoon , Jin Jung‐Il , Lee Seung Hee , Kim Young Kwan
Published: October 2008

The different effects on the photodegradation‐induced photoluminescence (PL) of π‐conjugated polymeric thin films upon the doping of Ir(III) containing triplet emitters in ambient conditions at room temperature were investigated. In this study, we prepared spin‐coated thin films using three different polymer matrices including poly(9‐vinylcarbazole) (PVK), poly[9,9‐bis(2‐ethylhexyl)fluorene‐2,7‐diyl] (PF2/6), and poly[2‐(5′‐cyano‐5′‐methyl‐hexyloxy)‐1,4‐phenylene] (CNPPP) derivatives doped with Ir(III) containing triplet emitters: Ir(III) bis[(4,6‐fluorophenyl)‐pyridinato‐N,C2′] picolinate (FIrpic), or Ir(III)fac‐tris(2‐phenylpyridine) (Ir(ppy)3), or Ir(III)bis(2‐(2′‐benzothienyl) pyridinato‐N‐acetylacetonate) (Ir(btp)2acac). Using the doped films, and their neat films, on quartz substrates, the UV‐Visible absorption (UV‐Vis) and PL spectra were recorded under continuous illumination with the excitation wavelengths at the absorption maxima of the corresponding matrix polymers. The dopant effects on the photodegradation‐induced PL were extracted from the kinetic data obtained from the doped films by subtracting the mutual degradation kinetics of their corresponding neat films. The obtained dopant effects show a strong correlation between the photo‐induced PL degradation and the exciton migration behaviors. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2395–2403, 2008
Micromechanics model based on the nanostructure of PFSA membranes
Authors: Kusoglu Ahmet , Santare Michael H. , Karlsson Anette M. , Cleghorn Simon , Johnson William B.
Published: October 2008

A micromechanics model is developed to predict Young's modulus of perfluorosulfonic acid (PFSA) membranes at various temperatures and water contents. The morphology of PFSA membranes is characterized by a two‐phase structure, where hydrophilic clusters expand to hold water molecules during swelling, whereas the hydrophobic polymer network maintains the structural stability. A representative volume element (RVE) is proposed based on the descriptions for the nanostructure of PFSA membranes available in the literature. On the basis of mechanics model, we estimate Young's modulus in tension of PFSA membranes as a function of water volume fraction for various temperatures. The results show that inclusion of water‐filled cylindrical channels connecting the spherical clusters yields significantly better prediction than considering spherical clusters alone. Comparison of these results with the existing experimental data shows good agreement over a range of temperatures. This study takes into account current understanding of the nanostructure of these materials and incorporates it into a micromechanics model that agrees well with the experimental results. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2404–2417, 2008
Synthesis and characterization of magnetoelectric polymer nanocomposites
Authors: Prabhakaran T. , Hemalatha J.
Published: October 2008

Magnetoelectric polymer nanocomposite structures are synthesized using conducting polyaniline and nanosized BFO particles through in situ sol–gel polymerization. The effect of nanosized BFO in polyaniline matrix is studied. The SEM, XRD, VSM, FTIR, and UV–Vis studies were made to understand the morphology, crystalline structure, magnetic, and optical properties of PANI/BFO composites with various concentrations of nanofiller. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2418–2422, 2008
Structures and photoactive properties of poly(styrene‐co‐vinylbenzophenone)
Authors: Hong Kyung Hwa , Sun Gang
Published: October 2008

Poly(styrene‐co‐vinylbenzophenone) prepared by a graft reaction on polystyrene revealed photoactive properties under irradiation of UVA. The photoactive structural features of the polymer were examined via electron paramagnetic resonance (EPR) under irradiation of UVA and fluorescent light. The photoactive functions of the polymer such as antimicrobial performance and dye decolorization ability were investigated. The results revealed that the poly(styrene‐co‐vinylbenzophenone) could generate radicals under fluorescent and UVA irradiation, and some radicals could stay alive for about 30 min in a dark chamber. The photoexcited polymer showed excellent antibacterial ability and decolorization effect on methylene blue and methyl orange dye under both daylight and UVA light. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2423–2430, 2008
From quantum dots and nanocrystals to organic systems and biomolecules: Excitons and excitonic processes on their way from fundamental research to applications. 8th International Conference on Excitonic Processes in Condensed Matter (EXCON '08), Kyoto, Japan, 22–27 June 2008
Authors: Petelenz Piotr , Schreiber Michael
Published: October 2008

This conference report is meant to offer a selective overview on a recently held scientific meeting rather than a comprehensive list of the conference presentations. We tried to describe what we feel were the most interesting contributions at EXCON'08. This conference maintained the focus of the EXCON series on both, experimental and theoretical topics of current research in excitonic processes in organic and inorganic condensed matter, considering also other subjects re‐ lated to excitonic processes. It provided an interdisciplinary forum for photo‐physicists, photo‐chemists and material scientists who discussed novel and new results in the field of excitons.

The full Proceedings of the 8th International Conference on Excitonic Processes in Condensed Matter (EXCON'08) shall be published in phys. stat. sol. (b) and phys. stat. sol. (c) in December 2008. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis of MnGeO3 polycrystalline and single‐crystal samples and comparative analysis of their magnetic properties
Authors: Sapronova N. V. , Volkov N. V. , Sablina K. A. , Petrakovskii G. A. , Bayukov O. A. , Vorotynov A. M. , Velikanov D. A. , Bovina A. F. , Vasilyev A. D. , Bondarenko G. V.
Published: October 2008

MnGeO3 single crystals have been grown by a flux method. The obtained MnGeO3 is orthorhombic; a Pbca space group does not undergo any structural phase transitions in the range from room temperature to 900 °C. Magnetic measurements carried out for the first time on the MnGeO3 single crystal have revealed higher values (TN = 38 K and θ = –100 K) as compared to the data for polycrystalline samples reported in the literature (TN = 10 K and 14 K, θ = –54 K and –46 K). These magnetic parameters for polycrystalline samples synthesized by us are close to the literature data. A Mössbauer spectrum taken at T = 300 K for a sample containing 5% Fe257O3 shows that manganese ions, Mn2+, occupy two nonequivalent positions and iron is included in a sublattice as Fe2+ and distributed among two positions substituting Mn2+. In this study, the magnetic characteristics are shown to be sensitive even to minor impurity amounts. The MnGeO3 magnetic structure and one of possible reasons causing the effect of impurities on the MnGeO3 magnetic properties are considered in the framework of a simple indirect coupling model. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic structure of Fe4Si4–xGex (x = 0–4) compounds: ab initio calculation
Authors: Ameereh G. I. , Hamad B. A. , Khalifeh J. M.
Published: October 2008

The structural and electronic properties of Fe4Si4–x Gex (x = 0–4) with a cubic B20‐type structure are investigated by density functional theory using an ab initio method. The calculations are based on a plane‐wave expansion of the electronic wave functions and performed using the local density approximation. It is found that these compounds are narrow‐gap semiconductors in the non‐magnetic state. The band gap is found to decrease with increasing x, and the B20 FeSi is a small‐gap semiconductor with sharp density of states features near the top of the valence band. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ultrasonic study on RuSr2GdCu2O8
Authors: Li H. L. , Zhang H. , Wang W. , Xiang X. Q. , Zhang Y. Q. , Li X. G.
Published: October 2008

The physical properties of RuSr2GdCu2O8 have been investigated by ultrasonic measurements. The huge stiffening of the velocity and the sharp elastic energy loss peak with the asymmetric shape near 220 K both indicate a phase transformation in the sample, which is induced by the disorder to order transformation of the orientation of RuO6 octahedra. The softening of the velocity and the elastic energy loss peak near 132 K may give further evidence to the strong spin–phonon interaction in the compound, and suggest a complex interplay of spin and lattice degrees of freedom in RuSr2GdCu2O8. A velocity jump and a decrease of the elastic energy loss are observed around the onset of the superconducting transition temperature TC,onset ∼ 50 K. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preparation and luminescence property of Sm‐doped ZnWO4 powders and films with wet chemical methods
Authors: He H. Y.
Published: October 2008

Sm‐doped ZnWO4 powders and films have been prepared with wet chemical methods. XRD analysis indicated that single‐phase Sm‐doped ZnWO4 were formed above a calcining temperature of 400 °C, and the particle size and intensity of XRD peak of the powders were varied with calcining schedules. SEM micrographs indicated that powders and films had uniform morphology and a grain size of about 10–150 nm, which increased with increasing calcining temperature. Compared with the ZnWO4 powders synthesized with the same method, Sm‐doped ZnWO4 powders showed obviously less crystallinity and smaller grain size and more dispersive morphology. The Sm‐doped ZnWO4 and undoped materials showed broad emissions in the blue‐green bands. The Sm‐doped ZnWO4 materials showed red emissions near 567 nm, 603 nm, and 641 nm. The intensities of the blue‐green emission and the red emission were increased with the crystallinity and the grain size of the powders. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the large temperature variation of the dielectric constant of Na0.4K0.6Br
Authors: Katsika‐Tsigourakou V. , Bekris P.
Published: October 2008

Since polycrystals of alkali halides are highly useful as components in optical devices, a number of mixed crystals of NaBr and KBr have been recently prepared from melts by other workers. Among these crystals, it was reported that the polycrystal Na0.4K0.6Br exhibits the strongest temperature variation of the dielectric constant. Here, we show quantitatively that this is due to the temperature variation of the ionic polarizability. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Emergence of optical magnetism in stratified metal–dielectric metamaterials
Authors: Iwanaga Masanobu
Published: October 2008

Optical magnetism in stratified metal–dielectric metamaterials (SMDM) has been explored numerically. Effective permeability and permittivity in the semi‐infinite SMDM have been extracted by two‐complex reflectivity method. Huge negative permeability has been achieved and found that the real part reaches about –200 at 1.585 eV. The origin of the huge optical magnetism is ascribed to the exotic magnetic field distributions in SMDM. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spontaneous emission rate of a single‐impurity molecule depending on a crystalline host
Authors: Rebane Inna , Koch Rein
Published: October 2008

The influence of the anisotropy of the host crystal on the spontaneous emission rate of the single‐impurity molecule and thus also on the radiative line width has taken into account. The anisotropy reveals itself in the dependence of the spontaneous emission rate on the orientation of the radiative transition dipole moment in the crystal. In this paper calculations of the relative spontaneous emission rate (the spontaneous emission rate divided by the spontaneous emission rate in the case when the transition dipole moment is parallel to the optical axis) of the quadrupole transition in a uniaxial host crystal are presented in the form which is convenient for experimenters. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Picosecond transient absorption and excitonic luminescence at low temperature in undoped ZnO
Authors: Ucer K. Burak , Wall R. Andrew , Lipke Kyle C. , Williams R. T.
Published: October 2008

Transient optical absorption is observed upon band‐gap excitation of undoped single‐crystal ZnO. Using 2‐photon excitation by 300 fs pulses of 410 nm light to create electron–hole pairs and an infrared continuum pulse to probe absorption, the evolution of induced absorption has been measured in the time range 2–100 ps at 17 K. Approximately 38% of the induced absorption decays with a time constant of 50 ps. Based on measurements of 50 ps lifetime for neutral donor‐bound exciton luminescence (D0X) in the same samples in our laboratory and the known dominance of D0X luminescence at low temperature in many studies of undoped ZnO, we assign the 50 ps infrared absorption to photoionization of the bound excitons. The observed spectral shape of the absorption band rises monotonically with increasing wavelength from 950 nm to 1600 nm, very similar to expectation of the shape of free‐carrier absorption. Since both the internal electron–hole binding energy and the binding of center‐of‐mass motion to the neutral donor are much less than the transition energies of 0.8–1.3 eV observed in absorption, it can be argued that the broad infrared absorption signal is a measure of the combined population of free carriers, shallow trapped carriers, and bound or free excitons. Based on this hypothesis, we deduce from the time‐dependent infrared absorption that the quantum efficiency of D0X luminescence in this sample is approximately 38%. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Protein‐like behavior of multiblock copolymer chains in a selective solvent by a variety of lattice and off‐lattice Monte Carlo simulations
Authors: Lewandowski K. , Knychała P. , Banaszak M.
Published: October 2008

We present both lattice and off‐lattice Monte Carlo simulations for multiblock copolymer chains of two lengths, N = 64 and N = 128, with microarchitectures (8–8)4 and (16–16)4, respectively. The simulations demonstrate that a variety of lattice and off‐lattice Monte Carlo methods gives the same protein‐like behavior, showing that the multiblock chains undergo a two‐step transition, first from a swollen state to a secondary “pearl‐necklace” state, and then to a tertiary superglobular state as the solvent quality decreases, that is upon cooling. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Strong anisotropic thermal expansion in borates
Authors: Bubnova Rimma S. , Filatov Stanislav K.
Published: October 2008

The paper summarizes results of high‐temperature single crystal X‐ray diffraction studies for six borate structures and high‐temperature powder X‐ray diffraction data for about 50 borates. The characteristics on thermal expansion of 50 borates of univalent, bivalent and trivalent metals of different dimensionality and anion structure are listed. The basic principles of high‐temperature borate crystal chemistry emerge from these studies and the regularities of borate thermal behavior are revealed. On heating the BO3 and BO4 polyhedra and rigid groups consisting of these polyhedra practically do not change their configuration and size but sometimes rotate like hinges exhibiting greatly anisotropic thermal expansion including linear negative expansion. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
EXAFS studies of negative thermal expansion materials
Authors: Fornasini Paolo , Ahmed Sameh I. , Sanson Andrea , Vaccari Marco
Published: October 2008

Extended X‐ray absorption fine structure (EXAFS) can give information on the local dynamical behavior of crystals, opening new perspectives for understanding the origin of negative thermal expansion (NTE). In this paper, after a short review on the effects of thermal disorder in EXAFS spectra and on the relation between EXAFS and Bragg diffraction, some recent results on crystals with the zincblende and cuprite structures are presented and critically compared. The tension effect giving rise to NTE can be correlated to the anisotropy of the mean square relative displacements measured by EXAFS. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermodynamic and mechanical stability of many‐body systems interacting with coarse‐grained bounded potentials
Authors: Brańka A. C. , Heyes D. M.
Published: October 2008

We discuss the stability criteria of Fisher and Ruelle [J. Math. Phys. 7, 260 (1966)] which can be used to establish if a given pair potential satisfies the requirements for thermodynamic stability. The mechanical and thermodynamic stability are considered for systems composed of particles interacting with a bounded potential, which could be used to model a mesostructured material at a coarse‐grained level. The elastic moduli of fcc and bcc solids at zero temperature are calculated as a function of density for an assembly of particles interacting via the following (at r = 0 bounded potentials: (a) a Gaussian Core Model, GCM, potential, φ (r) = exp (–r2), and (b) the separation‐shifted Lennard–Jones, SSLJ, bounded potential, φ (r) = 4[1/α2 + r2)6 – 1/(α2 + r2)3], with α > 0, where in both cases the characteristic energy and lengthscale are set to unity, and r is the separation between the particles. For both potential forms, at low densities, the static fcc structure is the thermodynamically stable structural form but from above a certain density the bcc lattice becomes the stable structure. It is shown that for the SSLJ potential this transition density varies roughly as ∼α–3. In the T → 0 limit, auxetic behaviour is demonstrated to occur for both fcc and bcc structures, but at high pressure and for the bcc structural form its response to external strain can be entirely nonauxetic. A significant role of the attractive part of the interparticle interaction in enhancing auxetic behaviour is observed. The ranges of the mechanical stability are determined for both systems. At zero temperature, the lattice becomes mechanically unstable for α > αc, which appears to coincide with the value αc = (7/32)1/6 = 0.7762 proved previously to lead to thermodynamically unstable fluid states for this potential. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Activity‐guided isolation of a novel protein from Croton tiglium with antifungal and antibacterial activities
Authors: Shahid Muhammad , Tayyab Muhammad , Naz Farah , Jamil Amer , Ashraf Muhammad , Gilani Anwarul Hassan
Published: October 2008

This study describes the activity‐guided isolation and purification of a novel antimicrobial protein from the seed of Croton tiglium Linn. Purification was carried out by (NH4)2SO4 precipitation, gel filtration and DEAE‐cellulose ion‐exchange chromatography. Antifungal and antibacterial activities were determined after each purification step. SDS‐polyacrylamide gel electrophoresis revealed that the purified protein was a monomer with molecular mass of 50 kDa. This is a first report on purification of a protein from Croton tiglium, which possesses a strong and broad spectrum antimicrobial activity. Copyright © 2008 John Wiley & Sons, Ltd.
Garlic extract exhibits antiamyloidogenic activity on amyloid‐beta fibrillogenesis: relevance to Alzheimer's disease
Authors: Gupta Veer Bala , Indi S. S. , Rao K. S. J.
Published: October 2008

Alzheimer's disease is characterized pathologically by the deposition of amyloid plaques. Fibrillar Aβ is the principal component of amyloid plaques in the brain of AD patients. The prevention of Aβ aggregation or dissolution of fibrillar Aβ has clinical significance. The present communication examined in vitro the antiamyloidogenic properties of garlic extract. The effects of aqueous garlic extract (both fresh and boiled) on Aβ aggregation and defibrillation were studied by thioflavin‐T based fluorescence assay, transmission electron microscopy and SDS‐polyacrylamide gel electrophoresis. The aqueous fresh garlic extract not only inhibited Aβ fibril formation in a concentration and time dependent manner but was also able to defibrillate Aβ preformed fibrils. The maximum defibrillization was observed after 2–3 days of incubation. The boiled aqueous garlic extract also retained its antiamyloidogenic activity. This indicated that antiamyloidogenic activity of garlic extract is non‐enzymatic, i.e. proteases present in garlic did not degrade Aβ in solution. However, the fibril degrading ability of boiled garlic extract was significantly lost. The findings suggest that consumption of garlic may lead to inhibition of Aβ aggregation in human brain. Copyright © 2008 John Wiley & Sons, Ltd.