bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and properties of ionically cross‐linked chitosan nanoparticles
Authors: Liu Hui , Gao Changyou 
Published: November 2008

AbstractChitosan nanoparticles were fabricated by a method of tripolyphosphate (TPP) cross‐linking. The influence of fabrication conditions on the physical properties and drug loading and release properties was investigated by transmission electron microscopy (TEM), dynamic light scattering (DLS), and UV–vis spectroscopy. The nanoparticles could be prepared only within a zone of appropriate chitosan and TPP concentrations. The particle size and surface zeta potential can be manipulated by variation of the fabrication conditions such as chitosan/TPP ratio and concentration, solution pH and salt addition. TEM observation revealed a core–shell structure for the as‐prepared nanoparticles, but a filled structure for the ciprofloxacin (CH) loaded particles. Results show that the chitosan nanoparticles were rather stable and no cytotoxicity of the chitosan nanoparticles was found in an in vitro cell culture experiment. Loading and release of CH can be modulated by the environmental factors such as solution pH and medium quality. Copyright © 2008 John Wiley & Sons, Ltd.
Preparation and characterization of polypropylene and waste tire powder modified by allylamine blends
Authors: Lee Sung Hyo , Shanmugharaj A. M. , Sridhar V. , Zhang Zhen Xiu , Kim Jin Kuk 
Published: November 2008

AbstractWaste tire powder subjected to allylamine modification in the presence of ultraviolet (UV) radiation has been used to prepare polypropylene based thermoplastic vulcanizates with maleic anhydride polypropylene (MA‐PP) as compatibilizer. The effect of increasing the concentration of MA‐PP on performance characteristics like tensile strength, elongation and rheological properties have been investigated. X‐ray diffraction studies of the PP/waste tire powder blend indicate the disappearance of β crystalline peaks on addition of waste tire powder in the PP, whereas it is observed in the allylamine modified rubber powder loaded PP. Differential scanning calorimetry results further supported the above fact. The improvement in mechanical properties of the PP/allylamine modified rubber powder loaded thermoplastic vulcanizates has been explained in terms of βα transformation of PP crystals during straining of the samples and uniform dispersion of allylamine coated rubber powder in the PP matrix. The melt rheological properties of the thermoplastic vulcanizates loaded with modified rubber powder are higher than its counterpart due to the higher dispersion as a result of chemical interaction between the rubber powder surface with the MA‐PP. Copyright © 2008 John Wiley & Sons, Ltd.
Microstructure‐thermal property relationship of high trans‐1,4‐poly(butadiene) produced by anionic polymerization of 1,3‐butadiene using an initiator composed of alkyl aluminum, n‐butyl lithium, and barium alkoxide
Authors: Benvenuta‐Tapia Juan J. , Tenorio‐López José A. , Herrera‐Nájera Rafael , Ríos‐Guerrero Leonardo 
Published: November 2008

AbstractThis article deals with the characterization of high trans‐1,4‐poly(butadiene) (TPBD) prepared by means of an anionic polymerization using an initiator composed of alkyl aluminum, n‐butyl lithium, and barium alkoxide. By controlling both initiator composition and polymerization temperature, a set of TPBD was prepared with well‐known number of 1,4‐trans units, molecular weight distribution, and average molecular weight. Analyses by differential scanning calorimetry and diffraction of wide‐angle X‐rays showed a direct relationship between the microstructure of the polymer and its thermal properties. By increasing the number of 1,4‐trans units (70–90%), the crystallinity of the polymer was increased (10–30%); polymers with less than 65% of 1,4‐trans units were amorphous, whereas TPBD with a number of 1,4‐trans units greater than 80% were polymorphous and presented two endothermic transitions. Summing up, the results presented in this article indicate that cyclohexane solutions of alkyl aluminum, n‐butyl lithium, and barium alkoxide allow produce polybutadienes with enough amount of 1,4‐trans units to display a regular microstructure that makes them susceptible to experience‐induced crystallization, likewise at a reaction rate similar to that observed for the commercial production of poly(butadiene) with n‐butyl lithium. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Optimal design of the coat‐hanger die used for producing melt‐blown fabrics by finite element method and evolution strategies
Authors: Meng Kai , Wang Xinhou , Huang Xiubao 
Published: November 2008

AbstractIn this article, an optimal design procedure that improves the uniformity of flow rate distribution at the outlet of the coat‐hanger die is proposed. The two‐membered evolution strategy was combined with the finite element method to optimize the design parameters of an initial coat‐hanger die geometry designed by analytical method based on one‐dimensional lubrication method. The slot gap and the manifold angle were chosen to be the optimized design parameters, and the coefficient of variation (CV) value of the flow velocity at the die outlet is regarded as the objective function. The optimal results were achieved in the 22nd generation after 100 generations' evolution, which show that the CV% value of the flow velocity at the die outlet is only 1.3631% and decreases by 68% of the initial value caused by unoptimizable die geometry. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Preparation of fast pH‐responsive ferric carboxymethylcellulose/poly(vinyl alcohol) double‐network microparticles
Authors: Xiao Congming , Li Huaqun , Gao Yongkang 
Published: November 2008

AbstractBACKGROUND: Carboxymethylcellulose (CMC) and poly(vinyl alcohol) (PVA) are biocompatible, and their complex hydrogel shows pH responsiveness. Thus, they are chosen as starting materials to prepare physically dual‐crosslinked Fe‐CMC/PVA microparticles with improved properties.RESULTS: Fe‐CMC/PVA double‐network microparticles were obtained via a facile process under mild conditions. Sodium carboxymethylcellulose was crosslinked with ferric ions to form particles that contained aqueous PVA solution in an emulsion system. The hydrogel particles were then subjected to a freezing–thawing cycle to achieve further crosslinking; the size of the particles formed was in the range 0.2–1.2 µm. The microparticles were capable of maintaining the stability of proteins such as hemoglobin in an acidic environment and exhibited pH‐responsive release behavior.CONCLUSION: The pH responsivity of the Fe‐CMC/PVA physical double‐network microparticles is fast, which is helpful for effectively protecting a loaded bioactive substance. Thus, they may be potential candidates for pH‐sensitive applications. Copyright © 2008 Society of Chemical Industry
Predicting residue–residue contact maps by a two‐layer, integrated neural‐network method
Authors: Xue Bin , Faraggi Eshel , Zhou Yaoqi 
Published: November 2008

AbstractA neural network method (SPINE‐2D) is introduced to provide a sequence‐based prediction of residue–residue contact maps. This method is built on the success of SPINE in predicting secondary structure, residue solvent accessibility, and backbone torsion angles via large‐scale training with overfit protection and a two‐layer neural network. SPINE‐2D achieved a 10‐fold cross‐validated accuracy of 47% (±2%) for top L/5 predicted contacts between two residues with sequence separation of six or more and an accuracy of 24 ± 1% for nonlocal contacts with sequence separation of 24 residues or more. The accuracies of 23% and 26% for nonlocal contact predictions are achieved for two independent datasets of 500 proteins and 82 CASP 7 targets, respectively. A comparison with other methods indicates that SPINE‐2D is among the most accurate methods for contact‐map prediction. SPINE‐2D is available as a webserver at http://sparks.informatics.iupui.edu. Proteins 2009. © 2008 Wiley‐Liss, Inc.
XC1028 from Xanthomonas campestris adopts a PilZ domain‐like structure without a c‐di‐GMP switch
Authors: Li Tso‐Ning , Chin Ko‐Hsin , Liu Jyung‐Hurng , Wang Andrew H.‐J. , Chou Shan‐Ho 
Published: November 2008

AbstractThe crystal structure of XC1028 from Xanthomonas campestris has been determined to a resolution of 2.15 Å using the multiple anomalous dispersion approach. It bears significant sequence identity and similarity values of 64.10% and 70.09%, respectively, with PA2960, a protein indispensable for type IV pilus‐mediated twitching motility, after which the PilZ motif was first named. However, both XC1028 and PA2960 lack detectable c‐di‐GMP binding capability. Although XC1028 adopts a structure comprising a five‐stranded β‐barrel core similar to other canonical PilZ domains with robust c‐di‐GMP binding ability, considerable differences are observed in the N‐terminal motif; XC1028 assumes a compact five‐stranded β‐barrel without an extra long N‐terminal motif, whereas other canonical PilZ domains contain a long N‐terminal sequence embedded with an essential “c‐di‐GMP switch” motif. In addition, a β‐strand (β1) in the N‐terminal motif, running in exactly opposite polarity to that of XC1028, is found inserted into the parallel β3/β1′ strands, forming a completely antiparallel β4↓β3↑β1↓β1′↑ sheet in the canonical PilZ domains. Such dramatic structural differences at the N‐terminus may account for the diminished c‐di‐GMP binding capability of XC1028, and suggest that interactions with additional proteins are necessary to bind c‐di‐GMP for type IV fimbriae assembly. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Collision‐induced dissociation of 3‐keto anabolic steroids and related compounds after electrospray ionization. Considerations for structural elucidation
Authors: Pozo Oscar J. , Van Eenoo Peter , Deventer Koen , Grimalt Susana , Sancho Juan V. , Hernández Félix , Delbeke Frans T. 
Published: November 2008

AbstractThe collision‐induced dissociation of forty‐one 3‐keto anabolic steroids and related compounds has been studied using both triple quadrupole (QqQ) and hybrid quadrupole‐time of flight (QTOF) instruments. Due to the complexity of the product ion spectra of these analytes, which generate a large number of ions, only two specific regions were studied in depth: the product ions near the precursor ion (m/z ≥M–100) and the most abundant product ions at a collision energy of 30 eV. Accurate mass measurements were used in order to obtain an unequivocal assignment of the empirical formula and the origin of each selected product ion. Analytes have been divided into eight groups according to the number and position of double bonds and the presence of functional groups such as hydroxyl‐ or nitrogen‐containing rings. A correlation between the steroid structure and the product ions obtained has been postulated. The application of these correlations can be useful in the elucidation of feasible structures for unknown steroids and/or their metabolites. Copyright © 2008 John Wiley & Sons, Ltd.
An authentication method for proxy mobile IPv6 and performance analysis
Authors: Zhou Huachun , Zhang Hongke , Qin Yajuan 
Published: November 2008

AbstractProxy mobile IPv6 (PMIPv6) is a network‐based mobility protocol where the mobility management signaling is performed by a network entity on behalf of the node requiring mobility itself. To the best of our knowledge, no studies have been conducted in the area of proxy MIPv6 authentication method. This paper proposes an authentication method in proxy MIPv6. In addition to providing access authentication, the proposed authentication method prevents threats such as replay attack and key exposure. Also, we develop analytic models for the authentication latency and cost analysis. Then, the impacts of mobility and traffic parameters on the authentication cost and latency are analyzed, respectively. Copyright © 2008 John Wiley & Sons, Ltd.
Subjective prior distributions for modeling longitudinal continuous outcomes with non‐ignorable dropout
Authors: Paddock Susan M. , Ebener Patricia 
Published: November 2008

AbstractSubstance abuse treatment research is complicated by the pervasive problem of non‐ignorable missing data—i.e. the occurrence of the missing data is related to the unobserved outcomes. Missing data frequently arise due to early client departure from treatment. Pattern‐mixture models (PMMs) are often employed in such situations to jointly model the outcome and the missing data mechanism. PMMs require non‐testable assumptions to identify model parameters. Several approaches to parameter identification have therefore been explored for longitudinal modeling of continuous outcomes, and informative priors have been developed in other contexts. In this paper, we describe an expert interview conducted with five substance abuse treatment clinical experts who have familiarity with the therapeutic community modality of substance abuse treatment and with treatment process scores collected using the Dimensions of Change Instrument. The goal of the interviews was to obtain expert opinion about the rate of change in continuous client‐level treatment process scores for clients who leave before completing two assessments and whose rate of change (slope) in treatment process scores is unidentified by the data. We find that the experts' opinions differed dramatically from widely utilized assumptions used to identify parameters in the PMM. Further, subjective prior assessment allows one to properly address the uncertainty inherent in the subjective decisions required to identify parameters in the PMM and to measure their effect on conclusions drawn from the analysis. Copyright © 2008 John Wiley & Sons, Ltd.
A Hierarchically Ordered TiO2 Hemispherical Particle Array with Hexagonal‐Non‐Close‐Packed Tops: Synthesis and Stable Superhydrophilicity Without UV Irradiation
Authors: Li Yue , Sasaki Takeshi , Shimizu Yoshiki , Koshizaki Naoto 
Published: November 2008

AbstractA hierarchical TiO2 ordered hemispherical particle array with hexagonal‐non‐close‐packed (hncp) tops is prepared by pulsed laser deposition (PLD) using a polystyrene colloidal monolayer as a template. Compared with conventional lithography, the route presented has the advantage of low cost for producing hncp nanostructured arrays. This hierarchical particle array exhibits excellent superhydrophilicity with a water contact angle of 0° without further UV irradiation. The superhydrophilic property originates from oxygen defects or vacancies on the surface of the TiO2 nanoparticles produced by PLD and the increased roughness of the hierarchical particle arrays. More importantly, this property is very stable for half a year and could be used in self‐cleaning surfaces and microfluidic devices.
Magnetic Imaging of Cyanide‐Bridged Co‐ordination Nanoparticles Grafted on FIB‐Patterned Si Substrates
Authors: Ghirri Alberto , Candini Andrea , Evangelisti Marco , Gazzadi Gian Carlo , Volatron Florence , Fleury Benoit , Catala Laure , David Christophe , Mallah Talal , Affronte Marco 
Published: November 2008

AbstractPrussian blue CsNiCr nanoparticles are used to decorate selected portions of a Si substrate. For successful grafting to take place, the Si surface needs first to be chemically functionalized. Low‐dose focused ion beam patterning on uniformly functionalized surfaces selects those portions that will not participate in the grafting process. Step‐by‐step control is assured by atomic force and high‐resolution scanning electron microscopy, revealing a submonolayer distribution of the grafted nanoparticles. By novel scanning Hall‐probe microscopy, an in‐depth investigation of the magnetic response of the nanoparticles to varying temperature and applied magnetic field is provided. The magnetic images acquired suggest that low‐temperature canted ferromagnetism is found in the grafted nanoparticles, similar to what is observed in the equivalent bulk material.
Management of polycystic ovarian syndrome
Authors: Cho Li‐Wei , Atkin Stephen L. 
Published: November 2008

AbstractPatients with polycystic ovarian syndrome can be challenging as they usually present with multiple problems that may include weight gain, irregular periods, acne, hirsutism or infertility. Treatment should be tailored to the needs of the patient in a holistic manner. In this review, the authors detail the reproductive, metabolic and cardiovascular aspects of polycystic ovarian syndrome and how these features can be managed in general practice. Copyright © 2008 Wiley Interface Ltd
Changing times for the management of localised prostate cancer
Authors: Kirby Roger , Dasgupta Prokar 
Published: November 2008

AbstractWith recent NICE guidance emphasising the role of active surveillance for men with ‘low‐risk’ prostate cancer, the authors ask whether we can reliably identify those men with cancers that have a minimal risk of progression. While it is important for patients to be involved in treatment decisions, the diversity of opinion and the lack of high quality comparative data mean that there is no recommended ‘best practice’ for treatment of this disease. Copyright © 2008 Wiley Interface Ltd
Zur Reaktivität von dinuklearen Platina‐β‐diketonen gegenüber Phosphanen: Diacetylplatin(II)‐Komplexe und mononukleare Platina‐β‐diketone
Authors: Albrecht Christian , Wagner Christoph , Steinborn Dirk 
Published: November 2008

AbstractThe Reactivity of Dinuclear Platina‐β‐diketones with Phosphines: Diacetylplatinum(II) Complexes and Mononuclear Platina‐β‐diketonesAddition of mono‐ and bidentate phosphines or of AsPh3 to the platina‐β‐diketone [Pt2{(COMe)2H}2(μ‐Cl)2] (1) followed by the addition of NaOMe at −70 °C resulted in the formation of diacetyl platinum(II) complexes cis‐[Pt(COMe)2L2] (L = PPh3, 2a; P(4‐FC6H4)3, 2b; PPh2(4‐py), 2c; PMePh2, 2d; AsPh3, 2d) and [Pt(COMe)2(L⌢︁L)] (L⌢︁L = dppe, 3b; dppp, 3c), respectively. The analogous reaction with dppm afforded the dinuclear complex cis‐[{Pt(COMe)2}2(μ‐dppm)2] (4) that reacted in boiling acetone yielding [Pt(COMe)2(dppm)] (3a). The reactions 1 → 2/3 were found to proceed via thermally highly unstable cationic mononuclear platina‐β‐diketone intermediates [Pt{(COMe)2H}L2]+ and [Pt{(COMe)2H}(L⌢︁L)]+, respectively, that could be isolated as chlorides for L⌢︁L = dppe (5a) and dppp (5b). The reversibility of the deprotonation of type 5 complexes with NaOMe yielding type 3 complexes was shown by the protonation of the diacetyl complex 3b with HBF4 yielding the platina‐β‐diketone [Pt{(COMe)2H}(dppe)](BF4) (5c). All compounds were fully characterized by means of NMR and IR spectroscopies, and microanalyses. X‐ray diffraction analysis was performed for the complex cis‐[Pt(COMe)2(PPh3)2]·H2O·CHCl3 (2a·H2O·CHCl3).
Hydrogallierungsreaktionen mit den Monoalkinen H5C6‐C≡C‐SiMe3 und H5C6‐C≡C‐CMe3 – cis/trans‐Isomerie und Substituentenaustausch
Authors: Uhl Werner , Claesener Michael , Haddadpour Sima , Jasper Beate , Tiesmeyer Ines , Zemke Sarina 
Published: November 2008

AbstractHydrogallation Reactions Involving the Monoalkynes H5C6‐C≡C‐SiMe3 and H5C6‐C≡C‐CMe3 – cis/trans Isomerisation and Substituent ExchangePhenyl‐trimethylsilylethyne, H5C6‐C≡C‐SiMe3, reacted with different dialkylgallium hydrides, R2Ga‐H (R = Me, Et, nPr, iPr, tBu), by the addition of one Ga‐H bond to its C≡C triple bond (hydrogallation). The gallium atoms attacked selectively those carbon atoms, which were also attached to trimethylsilyl groups. The cis arrangement of Ga and H across the resulting C=C double bonds resulted only for the sterically most shielded di(tert‐butyl)gallium derivative, while in all other cases spontaneous cis/trans rearrangement occurred with the quantitative formation of the trans addition products. The diethyl compound Et2Ga‐C(SiMe3)=C(H)‐C6H5 (2) gave by substituent exchange the secondary products EtGa[C(SiMe3)=C(H)‐C6H5]2 (7, Z,Z) and Ga[C(SiMe3)=C(H)‐C6H5]3 (8). Interestingly, compound 8 has two alkenyl groups with a Z configuration, while the third C=C double bond has the cis arrangement of Ga and H (E configuration). The reversibility of the cis/trans isomerisation of hydrogallation products was observed for the first time. tert‐Butyl‐phenylethyne gave the simple addition product, R2Ga(C6H5)=C(H)‐CMe3 (9), only with di(n‐propyl)gallium hydride.
Polytellurides and Polyselenides – Compounds Containing $_{\infty}^{1}\rm [Te_{6}-Te_{4}]^{4-}$ and [Sn(Se4)3]2− Anions
Authors: Wang Jian‐Qiang , Hoffmann Stephan D. , Fässler Thomas F. 
Published: November 2008

AbstractThe reactions of the Zintl phase K2Cs2Sn9 with elemental tellurium and selenium in ethylenediamine have been investigated. From the reaction of K2Cs2Sn9 with elemental tellurium [K‐(2,2,2‐crypt)]4Te6Te4 (2) and [K‐(2,2,2‐crypt)]2Sn2Te3 (3) were obtained, whereas the reaction of K2Cs2Sn9 with elemental selenium led to the formation of [K‐(2,2,2‐crypt)]2Sn(Se4)3 (4) and [K‐(2,2,2‐crypt)]2Cs2Sn2Se6·2en (5)1). Compounds 2, 4, 5 have been characterized by single crystal X‐ray structure determination.
Intraoperative Consultation as an Instrument of Quality Management
Authors: Teichmann Wolfgang , Rost Wilm , Thieme Daniel , Petersen Sven 
Published: November 2008

AbstractBackgroundThis study was designed to investigate the effectiveness of intraoperative consultation (IOC) with regard to its feasibility for improving quality management. IOC comprises an assessment of major steps in the operative procedure by another surgeon requested by the operating surgeon to be present in the operating room in a consultative capacity during the operation.MethodsBetween January and June 2008, IOC was implemented in 1217 operations. Data on the frequency of the feasibility of IOC and on whether IOC led to decisions influencing the course of the procedure were measured.ResultsA total of 872 IOCs were performed: regular IOC in 708 cases (81%), and tactical IOC in 164 cases (19%). In 70 cases (8%), consultation resulted in minor changes, and in 59 cases (7%) major clinically relevant revision of the operative strategy was deemed necessary.ConclusionsIt was found that IOC can be performed in the majority of cases. In the case of tactical IOC in particular, a large number of treatment‐relevant decisions are taken. This means that in the area of operative disciplines, IOC represents a potential preventive strategy within the framework of quality management.