bluuebunny/crossref_metadata_2025 huggingface dataset:
Sorption of polycyclic aromatic hydrocarbons from aqueous solution by hexadecyltrimethylammonium bromide modified fibric peat
Authors: Tang Xuanyi , Zhou Yanbo , Xu Yanxiao , Zhao Qing , Zhou Xiao , Lu Jun
Published: April 2010

BACKGROUND: Fibric peat was modified by hexadecyltrimethylammonium bromide (HTAB) to improve its performance in sorption of polycyclic aromatic hydrocarbons (PAHs). The raw fibric peat (P‐R) and surfactant modified peat (P‐HTAB) were characterized by capillary rise test to determine the effect of HTAB on surface hydrophobicity. Effect of contact time was also investigated. Batch sorption data were fitted to the Freundlich model and pseudo‐second‐order model for isotherm and kinetics study.

RESULTS: P‐HTAB had a more hydrophobic surface than P‐R. After modification, the sorption coefficients (KOC) of naphthalene, phenanthrene and pyrene on fibric peat increased from 1590, 29661 and 204171 mL g−1 to 2006, 52410 and 358569 mL g−1, respectively; the sorption rate constants of naphthalene, phenanthrene and pyrene increased from 0.00057, 0.00036 and 0.00051 g µg−1 min−1 to 0.00062, 0.00140 and 0.00155 g µg−1 min−1, respectively. The sorption coefficients of PAHs were positively correlated with the octane‐water partition coefficients of PAHs.

CONCLUSIONS: The hydrophobicity of fibric peat was enhanced through modification by HTAB, which resulted in the improved sorption rate and sorption capacity for PAHs. The sorption performance of P‐HTAB reveals that it is an effective biosorbent for PAHs and has potential for treatment of wastewater containing hydrophobic organic contaminants. Copyright © 2010 Society of Chemical Industry
Optimization of the reaction parameters of epoxidation of rapeseed oil with peracetic acid
Authors: Milchert Eugeniusz , Smagowicz Anna , Lewandowski Grzegorz
Published: April 2010

BACKGROUND: The epoxidation of vegetable oils has been a subject of interest for many years; epoxidized oils are frequently used as plasticizers and as renewable materials for the manufacture of alcohols, glycols and many other complex compounds with excellent antioxidant and antifriction properties. In this work the epoxidation process of rapeseed oil (RO) with peracetic acid generated in situ by the reaction of 30 wt% hydrogen peroxide and acetic acid has been studied. Optimization studies were performed by application of a statistical experimental design method utilizing a rotatable‐uniform design.

RESULTS: The significant parameters for the RO epoxidation process were established as temperature, molar ratio of hydrogen peroxide to rapeseed oil, molar ratio of acetic acid to rapeseed oil and reaction time. The process description was based on five response functions: iodine number, epoxy number, conversion, yield and selectivity. The highest values of all functions with the exception of selectivity were achieved for the same values of parameters: temperature 65 °C, molar ratio of hydrogen peroxide to RO 11.1:1 mol mol−1, molar ratio of acetic acid to RO 1.89:1 mol mol−1 and reaction time 6 h.

CONCLUSION: In summary, these optimum parameters allow one to obtain epoxidized rapeseed oil with a yield of 66.2 mol% at an oil conversion of 91.0 mol% in mild and relatively safe conditions. The epoxy number of the product was 0.207 mol per 100 g, whereas the iodine number was 0.027 mol per 100 g. Copyright © 2010 Society of Chemical Industry
Alternative processing of scrambled genes generates protein diversity in the ciliate Chilodonella uncinata
Authors: Katz Laura A. , Kovner Alexandra M.
Published: April 2010

In ciliates, chromosomal rearrangements occur during the development of the somatic macronuclear genome from the germline micronuclear genome. These rearrangements are extensive in three ciliate classes—Armophorea, Spirotrichea, and Phyllopharyngea—generating a macronucleus with up to 20,000,000 gene‐sized chromosomes. Earlier, we have shown that these three classes also share elevated rates of protein evolution relative to other ciliates. To assess the evolution of germline‐limited sequences in the class Phyllopharyngea, we used a combination of traditional and walking PCR to analyze micronuclear copies of multiple genes from two lines of the morphospecies Chilodonella uncinata for which we had previously characterized macronuclear sequences. Analyses of the resulting data yield three main results: (1) conserved macronuclear (somatic) regions are found within rapidly evolving micronuclear (germline) regions; (2) gene scrambling exists within this ciliate lineage; and (3) alternative processing of micronuclear regions yields diverse macronuclear β‐tubulin paralogs. To our knowledge, this is the first study to demonstrate gene scrambling outside the nonsister class Spirotrichea, and to show that alternative processing of scrambled genes generates diversity in gene families. Intriguingly, the Spirotrichea and Phyllopharyngea are also united in having transient “giant” polytene chromosomes, gene‐sized somatic chromosomes, and elevated rates of protein evolution. We hypothesize that this suite of characters enables these ciliates to enjoy the benefits of asexuality while still maintaining the ability to go through sexual cycles. The data presented here add to the growing evidence of the dynamic nature of eukaryotic genomes within diverse lineages across the tree of life. J. Exp. Zool. (Mol. Dev. Evol.) 314B:480–488, 2010. © 2010 Wiley‐Liss, Inc.
Palladium‐catalyzed hydroxycarbonylation as the key step in the synthesis of a carbon‐14 labeled Maxi‐K channel blocker
Authors: Simeone Joseph P. , Braun Matthew P. , Liu Luping , Natarajan Swaminathan R.
Published: April 2010

Carbon‐14 labeled sodium formate was utilized for the preparation of a radiolabeled tracer to support the development of a Maxi‐K channel blocker. Key to the process was a palladium‐catalyzed hydroxycarbonylation of a bromoarene for installation of the radiolabel. Copyright © 2010 John Wiley & Sons, Ltd.
Information‐theoretic chemometric analyses of Raman data for chemical reaction studies
Authors: Chew Wee
Published: April 2010

A methodology of multivariate chemometric techniques based on the information‐theoretic approach was applied for elucidating chemical reaction information from a Raman data array Rm×ν that arises from in situ reaction monitoring. This reaction‐induced dynamic dataset Rm×ν can be contaminated by random cosmic ray spikes found in the midst of characteristic spectral variations associated with the disappearance or emergence of Raman active reactants, intermediates and products. Such spurious cosmic spikes were identified and removed using a novel and fast numerical approach based on maximum and minimum spectral entropy principles while preserving the genuine reaction‐induced spectral variations. Subsequently, the band‐target entropy minimization (BTEM) algorithm, a minimum spectral entropy based self‐modeling curve resolution technique, was applied to recover the pure component spectra of Raman active chemical species. Information gain through the chemometric analyses was calculated using information entropies with base 2 logarithm. This sequence of information‐theoretic chemometric analyses (or transinformations) was successfully tested on the reaction spectral data obtained from alcoholysis of acetic anhydride, which contains four Raman active chemical species. It is envisioned that this series of multivariate statistical analyses will be useful in chemical reaction studies and process analytical technology (PAT) applications that utilize in situ Raman spectroscopy to monitor transient dynamic changes in chemical concentrations, and also in Raman microscopy/imaging data containing spatial variations. Copyright © 2010 John Wiley & Sons, Ltd.
Vectorial descriptions of nonlinear Raman microscopy
Authors: Marrocco Michele
Published: April 2010

Two versions of nonlinear Raman microscopy have lately captured the attention of several experimental groups. They are based on two important spectroscopic techniques, namely, coherent anti‐Stokes Raman scattering and stimulated Raman scattering. Although experimental research progresses at a steady pace, conceptual investigations are hampered by heavy numerical calculations that are necessary to solve the vectorial problem of nonlinear interactions between electric fields and the matter being probed. Here, attempts at a simplified description of the vectorial structure of the nonlinear Raman response are examined in comparison with some examples conceived within the fully numerical treatment of the problem. The attempts are based on two different optical models. One is given by the three‐dimensional Gaussian approximation which reduces the spatial complexity of the interaction between electromagnetic fields and matter to a volume with Gaussian profiles. The other model, recently introduced in optical microscopy, preserves the diffracted structure of the focal volumes. This second strategy rests upon the breaking of the continuous character of diffraction in a way that only diffraction angles that are optically relevant are used in the theoretical treatment of the fields. The two different methods are discussed and compared on the basis of some instructive examples. Fast calculation is ensured by the simplified models without loss of the spectroscopic information. Copyright © 2010 John Wiley & Sons, Ltd.
Tourist modernisation and social legitimation in Spain
Authors: Mantecón Alejandro
Published: April 2010

Spain's modernisation has been based, to a large extent, on the so‐called ‘residential tourism’. Its two‐fold nature—as a production model and a type of lifestyle migration—has complex repercussions. The aim of this paper is to delve, with a qualitative approach, into the key factors that explain the current social legitimation of this process by the Spanish society. The research suggests that the process is legitimated by its definition as an essentially tourism phenomenon. The label ‘tourism’ acts as some sort of ‘funnel’ that would not allow to go through it the problems associated with lifestyle migration or urbanisation. Copyright © 2010 John Wiley & Sons, Ltd.
Parathyroid gland preservation and selective autotransplantation utilizing topical lidocaine in total thyroidectomy
Authors: Kuriloff Daniel B. , Kizhner Victor
Published: April 2010

Objectives/Hypothesis:

To review a new technique during total thyroidectomy that facilitates parathyroid gland preservation and selective autotransplantation utilizing topical 2% plain lidocaine as a spasmolytic/vasodilator agent.

Study Design:

Retrospective case series review at a university hospital.

Methods:

The study population comprised 100 consecutive patients (84 women and 16 men; mean age, 52 years) undergoing total thyroidectomy from January 2007 to December 2008. Interventions were: parathyroid glands (PGs) with signs of devascularization treated with a topical solution of 2% plain lidocaine in an attempt to restore blood flow before committing to autotransplantation.

Results:

The main outcome measure was the incidence of hypoparathyroidism. A total of 40 parathyroid glands were autotransplanted. None of the 100 patients developed permanent hypoparathyroidism. There were no adverse effects utilizing this technique.

Conclusions:

In our experience, the use of lidocaine spasmolysis is a useful technique in thyroid surgery for salvaging devascularized PGs. Its utility as a selection method for PG autotransplantation incurs minimal risk or cost and might further reduce the incidence of permanent hypoparathyroidism. Further study is warranted. Laryngoscope, 2010
Balloon dilatation eustachian tuboplasty: A clinical study
Authors: Ockermann Thorsten , Reineke Ulf , Upile Tahwinder , Ebmeyer Jörg , Sudhoff Holger H.
Published: April 2010

Objectives/Hypothesis:

To assess the feasibility of balloon dilatation eustachian tuboplasty (BET) as an option for treatment of patients with eustachian tube (ET) dysfunction.

Study Design:

Ethics approved case controlled interventional study.

Methods:

Eight patients were identified with poor ET function using a ET score and were assigned to the study. The endoscopic procedure involved the dilatation of the cartilaginous and bony portion of 13 ETs with a balloon catheter. Pre‐ and postinterventional computed tomography was performed. All patients were reassessed 1, 2, and 8 weeks after BET.

Results:

BET was technically easy to perform. No damage to essential structures, particularly the carotid canal, was found in the human study. Patients revealed a significant improvement of the ET score comparing pre‐ and the 2‐month post‐treatment results. Improvement was found to be time dependent.

Conclusions:

This newly introduced method of BET was found to be a feasible and safe procedure to inflate the ET. It significantly helped to improve ET function in our study group. However, larger long‐term studies are necessary to fully evaluate the clinical value of BET. Laryngoscope, 2010
Carbon dioxide laser‐assisted cartilage reshaping otoplasty: A new technique for prominent ears
Authors: Ragab Ahmed
Published: April 2010

Objectives/Hypothesis:

Most otoplasty techniques are variations of suturing and sculpting concepts. Thick cartilage and its tricky everlasting reshaping is a difficult task in suture techniques. It is more difficult to predict and control the final result in cartilage sculpting techniques. Animal studies demonstrated temperature‐dependent cartilage stress relaxation during laser application resulting in stable shape changes. The aim of this study was to describe a novel surgical technique of carbon dioxide laser‐assisted cartilage reshaping (CO2 LACR) otoplasty and to show its outcome.

Study Design:

Prospective case series study.

Methods:

Sixteen patients with 32 prominent ears were involved prospectively. Carbon dioxide laser evaporation of the perichondrium and partial thickness of the medial surface of auricular cartilage and a pair of parallel laser incisions on scaphal and conchal lines were performed. The cartilage was fixed with absorbable Vicryl mattress sutures. Demographics, early and late postoperative outcomes, patients/parents and doctors satisfaction in the follow‐up were studied.

Results:

A total of 32 ears underwent repair. Patients ages ranged from 4 to 7 years (mean, 5.5 years). Average follow‐up was 2.4 years. No cases required revision surgery. In late assessment 14 patients were pleased, two were satisfied, and no patients were unsatisfied. All patients had four to six of the six criteria for surgical success as defined by the study without complications.

Conclusions:

The present technique of CO2 LACR otoplasty resulted in endurance of auricular appearance and symmetry, with good to satisfactory outcome to patient/parent. Laryngoscope, 2010
Endoscopic nasopharyngectomy for salvage in nasopharyngeal carcinoma: A novel anatomic orientation
Authors: Wen Yi‐Hui , Wen Wei‐Ping , Chen He‐Xin , Li Jian , Zeng Yu‐Hui , Xu Geng
Published: April 2010

Objectives/Hypothesis:

Nasopharyngectomy for residual/recurrent nasopharyngeal carcinoma (NPC) using an endoscopic technique is less invasive than traditional methods. Our objective was to identify the important anatomic landmarks so that the endoscopic surgeon can avoid injury to the internal carotid artery and perform a nasopharyngectomy safely.

Study Design:

Anatomical study.

Methods:

Transnasal endoscopic dissection was carried out on three fresh adult cadaver specimens (six sides) after arterial latex injection. Measurements were made in 50 adult skulls (100 sides), detailing the distances between orienting critical landmarks and the internal carotid canal (external aperture).

Results:

Adequate exposure for endoscopic nasopharyngectomy is available by removing portions of the inferior turbinate, nasal septum, and medial pterygoid plate. Anatomy of the operative field (endoscopic view) is described. Orientating topical landmarks include: posterior portions of the inferior turbinate and nasal septum, fossa of Rosenmuller, and the torus tubarius. The deep landmarks include: medial pterygoid plate–posterior margin at the skull base, eustachian tube isthmus, foramen lacerum, and the longus capitis. All topical and deep landmarks were identified from the endoscopic point of view and their distances to the internal carotid canal (external aperture) were measured.

Conclusions:

This anatomic study provides novel orienting landmarks for endoscopic nasopharyngectomy. Surgeons can efficiently and safely deal with residual and/or recurrent NPC endoscopically. Laryngoscope, 2010
Does thyroid gland examination by palpation alter serum hormone levels?
Authors: Toros Sema Zer , Ozel Leyla , Yekrek Mehmet Murat , Toros Ahmet Burak , Naiboglu Barıs , Kara Melih , Erdoğdu Erdal , Egeli Erol , Titiz İzzet
Published: April 2010

Objectives/Hypothesis:

The goal of this study was to investigate the effects of routine thyroid gland palpation on serum thyroid hormone levels.

Study Design:

Prospective study at Haydarpaşa Numune Research and Education Hospital, Istanbul, Turkey.

Methods:

This study was carried out in two groups with a total of 50 consecutive adults. Group I consisted of 20 patients (12 female and 8 male, aged 20–48 years) with a diagnosis of nodular thyroid disease confirmed by ultrasound imaging techniques. The second group consisted of 30 otherwise healthy subjects (17 female and 13 male, aged 18–50 years) referred for neck and thyroid ultrasound and with no thyroid pathology detected. Thyroid gland palpations were performed by the same physician. Blood samples were obtained before and 2 hours after thyroid gland palpation. Serum total T3 (TT3), total T4 (TT4), free T3 (FT3), free T4 (FT4), thyroid stimulating hormone (TSH), and thyroglobulin (TG) measurements were made.

Results:

We found that routine palpation in the first group caused a significant increase in serum TT3 (P < .05), FT3 (P < .01), FT4 (P < .05), and TG (P < .05) levels. In the second group, TT3 (P < .01), FT3 (P < .05), FT4 (P < .05), and TG (P < .05) levels also increased significantly after palpation. Differences in TSH and TT4 levels were not significant in any of the groups (P > .05).

Conclusions:

Preliminary data proposing a possible effect of routine thyroid gland palpation on serum thyroid hormone levels suggest that serum thyroid hormone measurements should be performed before any manipulation of the gland, including palpation, to avoid misdiagnosis. Laryngoscope, 2010
Statistical wind forecast for Reus airport
Authors: Traveria Miquel , Escribano Alejandro , Palomo Pablo
Published: April 2010

Crosswinds are usually a limiting factor for the normal operation of small size aircraft near an airport, and one of the first causes of weather related accidents. This paper presents a statistical downscaling model that provides a 24 h wind forecast at Reus airport (Spain).

The model is trained with 6 years historic data (1 January 2000 to 31 December 2005). The predictors are variables from two numeric weather prediction (NWP) model outputs: a mesoscale (MASS) and a global model reanalysis (GFS), at grid points near Reus airport. The predictands are the wind measured at the airport runway (METARs).

The downscaling model processes the historic data, making use of several data mining tools to optimize the forecasting accuracy. Primarily, examples are separated into four clusters. Following this, a selection of the predictor variables is made with every cluster. Finally, neural networks are developed to produce a wind forecast.

The downscaling model is relatively complicated, due to the different statistical techniques used, but has better forecasting accuracy than the NWP models used and other simpler statistical downscaling models. Copyright © 2010 Royal Meteorological Society
Tracking of myelin‐reactive T cells in experimental autoimmune encephalomyelitis (EAE) animals using small particles of iron oxide and MRI
Authors: Baeten Kurt , Adriaensens Peter , Hendriks Jerome , Theunissen Evi , Gelan Jan , Hellings Niels , Stinissen Piet
Published: April 2010

Myelin‐reactive T cells are responsible for initiating the cascade of autoreactive immune responses leading to the development of multiple sclerosis. For better insights into the disease mechanism, it is of major importance to have knowledge on the sites at which these cells are active during disease progression. Herein, we investigated the feasibility of tracking myelin‐reactive T cells, upon labelled with SPIO particles, in the central nervous system (CNS) of experimental autoimmune encephalomyelitis (EAE) animals by MRI. First, we determined the optimal labelling condition leading to a high particle uptake and minimal SPIO–Poly‐l‐lysine (PLL) aggregate formation using Prussian blue staining and inductively coupled plasma spectroscopy measurements. Results from labelling of myelin reactive T cells with low concentrations of SPIO particles (i.e. 25 µg/ml) combined with different concentrations of PLL (0–1.5 µg/ml) showed that increasing amounts of PLL led to augmented levels of free remnant SPIO‐PLL aggregates. In contrast, a low PLL concentration (i.e. 0.5 µg/ml) combined with high concentrations of SPIO (i.e. 400 µg Fe/ml) led to a high labelling efficiency with minimal amounts of aggregates. Second, the labelled myelin‐reactive T cells were transferred to control rats to induce EAE. At the occurrence of hindlimb paralysis, the SPIO labelled myelin‐reactive T cells were detected in the sacral part of the spinal cord and shown to be highly confined to this region. However, upon transfer in already primed rats, T cells were more widely distributed in the CNS and shown present in the spinal cord as well as in the brain. Our study demonstrates the feasibility of tracking SPIO labelled myelin‐reactive T cells in the spinal cord as well as the brain of EAE rats upon systemic administration. Furthermore, we provide data on the optimal labelling conditions for T cells leading to a high particle uptake and minimal aggregate formation. Copyright © 2010 John Wiley & Sons, Ltd.
A new optimal portfolio selection strategy based on a quadratic form mean–variance model with transaction costs
Authors: Peng Hui , Kitagawa Genshiro , Gan Min , Chen Xiaohong
Published: April 2010

A new optimal portfolio selection method within the Markowitz mean–variance framework is presented in this paper. The model proposed in the paper includes expected return, trading risk, and in particular, a quadratic form in the transaction costs of the portfolio. Using this model yields an optimal portfolio solution that maximizes return and minimizes risk as well as the transaction costs by moderating the transaction volume and smoothing the volume of traded securities in the trading process. A set of first‐order autoregressive (AR) models is utilized to estimate the future returns of the securities in the portfolio, and the AR parameters are estimated by the least‐squares method with a moving window. The optimization problem that results from this approach is convex and can thus be solved by quadratic programming (QP). A case study demonstrates the effectiveness and the significant performance improvements of the proposed optimal portfolio selection strategy. Copyright © 2010 John Wiley & Sons, Ltd.
Novel fluorinated polyimides derived from an unsymmetrical diamine containing trifluoromethyl and methyl pendant groups
Authors: Wang Chen‐Yi , Zhao Hui‐Peng , Li Guang , Jiang Jian‐Ming
Published: April 2010

Novel fluorinated polyimides were prepared from an unsymmetrical diamine, 3‐methyl‐4‐(4‐amino‐2‐trifluoromethylphenoxy)‐4'‐aminobenzophenone (3), with four aromatic dianhydrides via a one‐step high‐temperature polycondensation procedure. All the obtained polyimides were soluble in some polar solvents such as NMP, DMAc, and DMF. Flexible and tough films were prepared by casting from polymer solution. These polyimide films exhibited high optical transparency, good mechanical and thermal properties. Moreover, they possessed low dielectric constants and low‐moisture absorption. Due to their properties, these fluorinated polyimides could be considered as photoelectric and microelectronic materials. Copyright © 2010 John Wiley & Sons, Ltd.
Fire performance of flame retardant polypropylene and polystyrene composites screened with microscale combustion calorimetry
Authors: Lu Hongdian , Wilkie Charles A.
Published: April 2010

Flame retardant polypropylene (PP) and polystyrene (PS) materials were prepared by the incorporation of decabromodiphenyl oxide and Sb2O3 in addition to nanoparticles, montmorillonite clay, and carbon nanotubes (CNTs). Their fire performance was screened with microscale combustion calorimetry (MCC) as well as evaluated by cone calorimetry. The decabromodiphenyl oxide–Sb2O3 system exhibited better efficiency in reducing the peak heat release rate (PHRR) of PP compared to PS in the MCC, whereas the trend was the opposite in cone calorimetry. Introduction of clay or CNTs to the decabromodiphenyl oxide–Sb2O3 system was beneficial in reducing the PHRR of both composites in cone calorimetry; however, a reduction in the PHRR in the MCC was only observed in the PS composites. The thermogravimetric analysis (TGA) studies revealed that the fire results from the MCC for the two types of composites were strongly correlated with their thermal degradation traces. There were poor relationships between the parameters of MCC and cone calorimetry, but good correlation between the temperature difference of the first and second peak of mass loss rate in the TGA, temperature at the PHRR in the MCC, and fire performance index in the cone calorimetry. Copyright © 2010 John Wiley & Sons, Ltd.
Multi‐responsive methylcellulose/Fe‐alginate‐g‐PVA/PVA/Fe3O4 microgels for immobilizing enzyme
Authors: Xiao Congming , Ma Peipei , Geng Nannan
Published: April 2010

To take advantage of the respective character of methylcellulose (MC), poly(vinyl alcohol) (PVA), and alginate, novel physically cross‐linked methylcellulose/Fe‐alginate‐g‐PVA/PVA (MC/Fe‐Alg‐g‐PVA/PVA) microgels were prepared by emulsification/thermal gelation/freezing–thawing/ionic cross‐linking technique. Subsequently, some ferrous ions bound in the microgels were transformed into magnetite via in situ self oxidation. A model enzyme α‐amylase was immobilized into microgels by direct adsorption. The release behavior of α‐amylase indicated that the obtained complex microgels were magnetic‐, temperature‐, and pH‐ triple sensitive. Copyright © 2010 John Wiley & Sons, Ltd.
Structural evolution during uniaxial deformation of natural rubber reinforced with nano‐alumina
Authors: Nie Yijing , Huang Guangsu , Qu Liangliang , Zhang Peng , Weng Gengsheng , Wu Jinrong
Published: April 2010

The mechanical properties of natural rubber (NR) were enhanced by the inclusion of nano‐alumina. In order to gain further insights into the reinforcement mechanism, synchrotron wide‐angle X‐ray diffraction (WAXD) was used to monitor the evolution of the molecular structure during stretching in real time, and the tube model theory was applied to study the effect of nanoparticles on rubber network. For the filled rubber, the onset strain of crystallization shifted to much lower value compared with that of the unfilled, indicating the presence of special strain amplification effect, which can be revealed by the reduction of configurational entropy. In addition, the crystallinity increased and the lateral crystallite size decreased after the addition of the nanofiller. During deformation, the crystallites of the filled rubber showed lower orientational fluctuations differing from that of NR reinforced by carbon black. Copyright © 2010 John Wiley & Sons, Ltd.
Miltefosine loaded albumin microparticles for treatment of visceral leishmaniasis: formulation development and in vitro evaluation
Authors: Das Samir , Khan Wahid , Mohsin Shaikh , Kumar Neeraj
Published: April 2010

Introduction

Visceral leishmaniasis (VL) is one of the fatal parasitic diseases, currently threatening 500,000 new cases worldwide each year. The major front line drugs available for treating VL are toxic and develop resistance due to their long treatment regimen. With this assumption, present work has been designed to formulate miltefosine (MF) as microparticulate drug delivery system to target macrophages where leishmania parasite resides.

Methodology

MF is formulated using albumin as carrier and spray drying as method for the preparation of microparticles of desired size (≤6 µm) for intravenous administration. Microspheres were characterized morphologically and evaluated for particle size, product yield, and for drug polymer interaction. The ability of macrophages to phagocytosis these microspheres were investigated in RAW 264.7 cell line. In vitro hemolysis study was carried out to determine hemotoxicity of prepared microsphere formulation.

Results

The average size of the prepared microspheres were found to be nearly 3 µm with most of particles in the range of 2–5 µm. Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) confirmed no significant chemical interaction between the albumin and MF. Uptake study in macrophage cell line confirmed the targetability of prepared microspheres to macrophages. In vitro hemolysis study indicated reduced hemotoxicity and suitability of prepared microspheres for parenteral administration.

Conclusions

MF loaded microspheres of desired size were prepared successfully using spray drying method with thermal stabilization. In vitro hemolysis and uptake studies confirmed the suitability of prepared microspheres for targeting macrophages with reduced hemotoxicity. Copyright © 2010 John Wiley & Sons, Ltd.
Generating and confirming hypotheses
Authors: Gould A. Lawrence
Published: April 2010

Dr. Walker asserts that a hypothesis always can be tested using the same data source that generated the data if the test data are independent of the data generating the hypothesis. One way to do this is to use part of the totality of data to generate the hypothesis and the other to test the hypothesis. The validity of this assertion depends on what one means by ‘independent’. This note addresses the logical and statistical implications of Dr. Walker's assertion. The key conclusion is that what constititutes ‘independent’ data has to be considered carefully, and that hypothesis‐generating and test data from the same data source generally can not be considered ‘independent’. Copyright © 2010 John Wiley & Sons, Ltd.
Structural changes induced by deformation in an ethylene–(vinyl alcohol) copolymer: simultaneous measurements of uniaxial stretching and in situ wide‐angle X‐ray scattering
Authors: Cerrada María L , Fauth François , Fernández‐Blázquez Juan P , Pérez Ernesto
Published: April 2010

The deformation process of a semi‐crystalline ethylene–(vinyl alcohol) copolymer (with a vinyl alcohol content of 68 mol%) has been evaluated using simultaneously real‐time synchrotron X‐ray diffraction and stress‐strain experiments at 150 °C. Small changes are observed during the initial elastic region in monoclinic crystallites. However, significant modifications are found along the development of a neck in the yielding region. These involve the disappearance of the monoclinic crystals and the appearance of a strain‐induced phase of mesomorphic ordering that is rapidly oriented. This alignment is further slightly enhanced during the propagation of deformation through the specimen, leading to a final orientation function of around 0.92. Copyright © 2010 Society of Chemical Industry
Hybrid atom transfer radical polymerization system for balanced polymerization rate and polymer molecular weight control
Authors: Machado Mark , Faucher Santiago , Zhu Shiping
Published: April 2010

A hybrid polymerization system that combines the fast reaction kinetics of conventional free radical polymerization and the control of molecular weight and distribution afforded by ATRP has been developed. High‐free radical initiator concentrations in the range of 0.1–0.2 M were used in combination with a low concentration of ATRP catalyst. Conversions higher than 90% were achieved with ATRP catalyst concentrations of less than 20 ppm within 2 h for the hybrid ATRP system as compared with ATRPs where achieving such conversions would take up to 24 h. These reaction conditions lead to living polymerizations where polymer molecular weight increases linearly with monomer conversion. As in living polymerization and despite the fast rates and low ATRP catalyst concentrations, the polydispersity of the produced polymer remained below 1.30. Chain extension experiments from a synthesized macroinitiator were successful, which demonstrate the living characteristics of the hybrid ATRP process. Catalyst concentrations as low as 16 ppm were found to effectively mediate the growth of over 100 polymer chains per catalytic center, whereas at the same time negating the need for post polymerization purification given the low‐catalyst concentration. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2294–2301, 2010
Tuning the electronic properties of conjugated polymer by tethering low‐bandgap rhenium(I) complex on the main chain
Authors: Mak Chris S. K. , Leung Qing Yun , Li Chi Ho , Chan Wai Kin
Published: April 2010

Low‐bandgap rhenium(I) complex with absorption onset at 795 nm in solution was tethered onto π‐conjugated polymer. The conjugated copolymer provides solution processability of the metallopolymer, and the pendant allows the low energy‐absorbing Re(I) complex units to be evenly distributed on the thin film. The copolymer tethered with low‐bandgap rhenium complex was synthesized by Suzuki cross‐coupling reaction. The metal‐free polymer (poly‐1) tethered with functionalized intramolecular charge transfer dye, 2‐phenyl‐3‐pyridin‐2‐yl‐5,7‐di‐2‐thienylthieno[3,4‐b]pyrazine, exhibited high molecular weight, good film‐forming properties, and excellent solution processability. The pendants of the conjugated polymer possess donor–acceptor characters and broaden the absorption band. These pendants can function as bidentate ligands for metal chelation. The solubilizing groups on the monomers provide good solubility to the polymer even with high content of metal chelation. Upon the complexation with rhenium(I) pentacarbonyl chloride, the absorption spectrum of the resulting metallopolymer was further extended toward the near‐infrared region. Photovoltaic performances based on this metallopolymer have been studied. The design approach of these metallopolymers provides synthetic feasibility for coordinating wide range of metal ions on the pendant, and the resulting low‐bandgap polymer can be a potential candidate for light harvesting material in solar cell applications. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2311–2319, 2010
New ethyl cellulose/acrylic hybrid latexes and coatings via miniemulsion polymerization
Authors: Chen R. , Chu F. , Gauthier C. , Chazeau L. , Chaduc I. , Bourgeat‐Lami E. , Lansalot M.
Published: April 2010

Ethyl cellulose (EC) was incorporated into copolymer latexes via miniemulsion polymerization. The effects of EC viscosity and EC content on droplet size, particle size, and polymerization kinetics were investigated. The higher the EC content and viscosity, the larger the droplet size and the less stable the latex suspension. Small droplets that could be efficiently nucleated were formed for the lower‐viscosity EC but the latex still showed limited colloidal stability. This was attributed to some phase‐incompatibility between EC and the acrylic polymer. These stability issues were overcome by using an oil‐soluble initiator and a crosslinker. The later enabled to physically entrap EC inside the polymer particles, whereas the former allowed in situ grafting of the growing acrylic radicals to the EC backbone decreasing thereby the extent of phase separation. Thermal‐mechanical analyses evidenced that the films obtained from the hybrid latexes displayed better properties than the EC‐free latex films or the physical blends. This supports the hypothesis of formation of hybrid latexes that synergistically combine the properties of the acrylic matrix and the EC polymer. Interestingly, a significant increase of the elastic modulus was observed between 50 and 90 °C. This mechanical reinforcement was tentatively attributed to the formation of a percolating EC‐based hybrid phase. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2329–2339, 2010
Poly(γ‐benzyl‐L‐glutamate)‐functionalized single‐walled carbon nanotubes from surface‐initiated ring‐opening polymerizations of N‐carboxylanhydride
Authors: Tang Haoyu , Zhang Donghui
Published: April 2010

Single‐walled carbon nanotubes (SWCNTs) have been functionalized with poly(γ‐benzyl‐L‐glutamate) (PBLG) by ring‐opening polymerizations of γ‐benzyl‐L‐glutamic acid‐based N‐carboxylanhydrides (NCA‐BLG) using amino‐functionalized SWCNTs (SWCNT‐NH2) as initiators. The SWCNT functionalization has been verified by FTIR spectroscopy and transmission electron microscopy. The FTIR study reveals that surface‐attached PBLGs adopt random‐coil conformations in contrast to the physically absorbed or bulk PBLGs, which exhibit α‐helical conformations. Raman spectroscopic analysis reveals a significant alteration of the electronic structure of SWCNTs as a result of PBLG functionalization. The PBLG‐functionalized SWCNTs (SWCNT‐PBLG) exhibit enhanced solubility in DMF. Stable DMF solutions of SWCNT‐PBLG/PBLG with a maximum SWCNTs concentration of 259 mg L−1 can be readily obtained. SWCNT‐PBLG/PBLG solid composites have been characterized by differential scanning calorimetry, thermogravimetric analysis, wide/small‐angle X‐ray scattering (W/SAXS), scanning electron microscopy, and polarized optical microscopy for their thermal or morphological properties. Microfibers containing SWCNT‐PBLG and PBLG can also be prepared via electrospinning. WAXS characterization reveals that SWCNTs are evenly distributed among PBLG rods in solution and in the solid state where PBLGs form a short‐range nematic phase interspersed with amorphous domains. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2340–2350, 2010
Salt‐induced microphase separation of amorphous dendritic poly(ethylene oxide)‐block‐linear polystyrene copolymers
Authors: Cho Byoung‐Ki , Kim Seung‐Hyun , Lee Eunji
Published: April 2010

We prepared two block copolymers 1 and 2 consisting of a third‐generation dendron with poly(ethylene oxide) (PEO) peripheries and a linear polystyrene (PS) coil. The PS molecular weights were 2000 g/mol and 8000 g/mol for 1 and 2, respectively. The differential scanning calorimetry (DSC) data indicated that neither of the block copolymers showed glass transition, implying that there was no microphase separation between the PEO and PS blocks. However, upon doping the block copolymers with lithium triflate (lithium concentration per ethylene oxide unit = 0.2), two distinct glass transitions were seen, corresponding to the salt‐doped PEO and PS blocks, respectively. The morphological analysis using small angle X‐ray scattering (SAXS) and transmission electron microscopy (TEM) demonstrated that a hexagonal columnar morphology was induced in salt‐doped sample 1‐Li+, whereas the other sample (2‐Li+) with a longer PS coil revealed a lamellar structure. In particular, in the SAXS data of 2‐Li+, an abrupt reduction in the lamellar thickness was observed near the PS glass transition temperature (Tg), in contrast to the SAXS data for 1‐Li+. This reduction implies that there is a lateral expansion of the molecular section in the lamellar structure, which can be interpreted by the conformational energy stabilization of the long PS coil above Tg. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2372–2376, 2010
Synthesis and solvent‐dependent micellization of the amphiphilic block copolymer poly(styreneboronic acid)‐block‐polystyrene
Authors: Cui Chengzhong , Bonder Edward M. , Qin Yang , Jäkle Frieder
Published: April 2010

The amphiphilic organoboron block copolymer poly (styreneboronic acid)‐block‐polystyrene (PSBA‐b‐PS) has been prepared through a postpolymerization modification route from the silicon‐functionalized block copolymer poly(4‐trimethylsilylstyrene)‐block‐polystyrene (PSSi‐b‐PS). PSBA‐b‐PS is obtained through highly selective reaction of PSSi‐b‐PS with BBr3 at room temperature and subsequent hydrolysis of the BBr2‐functionalized intermediate. Transmission electron microscopy studies demonstrate that PSBA‐b‐PS undergoes pH dependent micellization in aqueous solution. Different morphologies could be realized by using different mixtures of water and organic solvents. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2438–2445, 2010
Structure‐property relationships in densely grafted π‐stacked polymers
Authors: Cappelli Andrea , Paolino Marco , Anzini Paolo , Giuliani Germano , Valenti Salvatore , Aggravi Marianna , Donati Alessandro , Mendichi Raniero , Zetta Lucia , Boccia Antonella Caterina , Bertini Fabio , Samperi Filippo , Battiato Salvatore , Paccagnini Eugenio , Vomero Salvatore
Published: April 2010

Three methyl end‐capped oligo(ethylene glycol) (MOEG) ethers (1b‐d) and a methoxyderivative (1a) of benzofulvene monomer BF3k were synthesized and induced to polymerize spontaneously by solvent removal to obtain soluble π‐stacked polymers bearing densely grafted MOEG side chains (poly‐1b–d) and model polymer poly‐1a. The physicochemical features (e.g., solubility, NMR, MALDI‐TOF, and absorption/emission spectra, as well as MWD, conformation plot, and thermal properties) of the synthesized polymers were compared in a structure‐property relationship study. This approach afforded the following evidence. The structure of poly‐1a–d is very similar to that of BF3k, suggesting that the polymerization mechanism is not affected by the presence of the electron‐rich methoxy group or bulkier MOEG side chains. However, the latter appear to be capable of affecting the conformational behavior of the polymer backbone. The solubility of poly‐1a–d depends on the number of the oligo(ethylene glycol) monomeric units. In particular, poly‐1d, featuring a long MOEG side chain (n = 9), shows an amphiphilic character and is soluble in a number of organic solvents, whereas it interacts with water to give isolated macromolecules in equilibrium with nanosized water‐soluble aggregates. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2446–2461, 2010
Thermoresponsive super water absorbent hydrogels prepared by frontal polymerization
Authors: Scognamillo Sergio , Alzari Valeria , Nuvoli Daniele , Mariani Alberto
Published: April 2010

Frontal polymerization was used as an alternative technique for the preparation of super water absorbent hydrogels obtained from acrylamide and 3‐sulfopropyl acrylate, potassium salt (SPAK) in the presence of N,N′‐methylene‐bisacrylamide as a crosslinker. All samples were synthesized in dimethyl sulfoxide, and their swelling behavior in water was investigated. It was found that their features are dependent on the monomer ratio used, which influenced the porous morphology, and consequently, the swelling capability. The swelling ratio ranges from about 1000% for the acrylamide homopolymer up to 14,000% for the sample containing 87.5 mol % of SPAK, thus indicating that this parameter can be easily tuned by using the appropriate monomer ratio. The affinity towards water was eventually confirmed by contact angle analysis. Polymer hydrogels made from at least 62.5 mol % SPAK exhibit a thermoresponsive behavior, with a lower critical solution temperature of ∼30 °C. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2486–2490, 2010
Supramolecular template‐directed synthesis of stable and high‐efficiency photoluminescence 9,10‐diphenylanthryl‐bridged ladder polysiloxane
Authors: Zhang Jintao , Chen Zhize , Fu Wenxin , Xie Ping , Li Zhibo , Yan Shouke , Zhang Rongben
Published: April 2010

A soluble well‐defined 9,10‐diphenylanthryl‐bridged ladder polysiloxane (DPAnLP) was prepared via supramolecular assembly‐directed condensation polymerization of silanols. The ladder superstructure (LS) was obtained via a synergistic interaction of H‐bonding and π–π stacking between polymerizable precursor 2‐tert‐butyl‐9,10‐bis(methyldihydroxylsilyl)anthracene in organic solvent. The resultant LS was then used as template to direct the condensation of silanol groups to obtain DPAnLP with high regularity. It was found that DPAnLP can emit blue light (430 nm) with great stability and high efficiency in both solution and solid film, which indicated a well organizing of fluorophore within confined environment (ladder structure). TGA and DSC measurements showed that DPAnLP had good thermal stability, and cyclic voltammetry detection gave a low‐lying highest occupied molecular orbital level. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2491–2497, 2010
Evaluation of the combined toxicity of 15 pesticides by uniform design
Authors: Zhang Ya‐Hui , Liu Shu‐Shen , Liu Hai‐Ling , Liu Zheng‐Zao
Published: April 2010

BACKGROUND: Environmental pesticides, including insecticides and herbicides, are frequently encountered as mixtures and threaten non‐target organisms in water. Evaluation of the combined toxicity of diverse pesticides with various concentration combinations is important, especially using limited experimental effort. Uniform design (UD) is one optimal experimental technique that can rationally arrange the concentrations of mixture components so that, with a minimum number of experimental runs, the combined toxicity of multiple pesticide mixtures can be evaluated.

RESULTS: The concentration compositions of 18 pesticide mixture points designed by UD covered almost all possible concentration ranges of the mixture components on account of the two merits of ‘space filling’ and ‘multiple levels’. The combined toxicities of 18 mixture rays extended by using the fixed‐ratio ray design (FRRD) from 18 UD mixture points were evaluated by concentration addition (CA) and independent action (IA) models. It was found that the concentration–response curves (CRCs) predicted by CA were, on the whole, located between the 95% confidence intervals of the experimental CRCs, which implied that the combined toxicity of the pesticide mixture rays could be evaluated by CA. The CRCs predicted by IA were very similar to those from CA.

CONCLUSION: The model developed from the UD mixture rays can effectively simulate mixtures with arbitrary concentration compositions of 15 pesticides. The CA model can accurately evaluate and predict the combined toxicity of the pesticides, which provides a useful tool for risk assessment of a mixture of multiple pesticides in the aquatic environment. Copyright © 2010 Society of Chemical Industry
Eslicarbazepine: new adjunctive treatment for partial epilepsy
Authors: Chaplin Steve , Kelso Andrew
Published: April 2010

Eslicarbazepine acetate (Zebinix) is a new antiepileptic drug licensed as adjunctive treatment for partialonset seizures. In our New products review, Steve Chaplin presents the clinical data relating to efficacy and adverse effects, and Dr Andrew Kelso discusses its potential role in epilepsy treatment. Copyright © 2010 Wiley Interface Ltd
Instanyl: intranasal fentanyl for treating breakthrough pain
Authors: Chaplin Steve , Zeppetella Giovambattista
Published: April 2010

Instanyl is an intranasal formulation of fentanyl licensed for breakthrough pain management in chronic cancer pain. In our New products review, Steve Chaplin presents the clinical data relating to its efficacy and adverse effects and Dr Giovambattista Zeppetella discusses its place in the management of breakthrough pain. Copyright © 2010 Wiley Interface Ltd
Prescriber 1990–2010: key developments in drug treatment
Authors: Dobson Ruth , Elrington Giles
Published: April 2010

We asked our editorial consultants to highlight the significant advances made in their therapeutic areas over the past 20 years. Here we look at developments in neurology and dermatology. Copyright © 2010 Wiley Interface Ltd