bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation, identification, and evaluation of PEGylated puerarin
Authors: Liu Xia , Ding Zhi‐Shan , Jiang Fu‐Sheng , Ding Xing‐Hong , Jin Bo , Chen Su‐Hong , Lv Gui‐Yuan
Published: May 2012

Cardiovascular disease is one of the most serious diseases threatening human health. Puerarin has been widely used in china as a cardiovascular agent. However, a major clinical limitation is its adverse effects of hemolysis. We have addressed this issue by PEGylation and synthesized a puerarin prodrug by covalently linking puerarin to the drug carrier monomethoxy‐poly(ethylene glycol) (mPEG). The covalent linkage was validated by UV, FTIR, 1H‐NMR, and matrix‐assisted laser desorption ionization‐time‐of‐flight mass spectrometry. The hemolysis assay showed that the prodrug produced minimal hematotoxicity. The hydrolysis profile showed that the prodrug was stable in a low pH environment and can continuously release the active drug in physiological condition in vitro. A pharmacokinetic study showed a prolongation of the elimination half‐life and a favorable distribution profile in organs, suggesting that the prodrug preparation produced fewer side effects on liver than the injectable form of puerarin normally used. Additionally, the protective effect of the prodrug on acute myocardial ischemia model implied better therapeutic effect than injectable puerarin. We show that the puerarin PEG conjugation is a promising prodrug that produces fewer side effects, exhibits better aqueous solubility, and is more effective than puerarin. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Green composites using switchgrass as a reinforcement for a conjugated linseed oil‐based resin
Authors: Pfister Daniel P. , Larock Richard C.
Published: May 2012

Switchgrass (SWG) has been used as a filler to produce conjugated linseed oil‐based green composites. The effect of the amount of the SWG; the matrix crosslink density; and the incorporation of a compatibilizer, maleic anhydride (MA), on the structure, water absorption, and thermal and mechanical properties of the composites has been investigated. The thermal stability of the composites is primarily dependent on the amount of the SWG fibers, which are far less thermally stable than the linseed oil‐based resin. For the most part, improvements in the mechanical properties can be achieved by increasing the amount of SWG (up to 70 wt %), increasing the amount of the crosslinker, and adding MA to increase the filler–matrix interaction. The uptake of water in the composites is mostly influenced by the loading of the SWG fibers. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Interior synthesizing of ZnO nanoflakes inside nylon‐6 electrospun nanofibers
Authors: Panthi Gopal , Barakat Nasser A. M. , Al‐Deyab Salem S. , El‐Newehy Mohamed , Pandeya Dipendra Raj , Kim Hak Yong
Published: May 2012

Doping of the polymeric electrospun nanofibers by metal oxides nanoparticles is usually performed by electrospinning of a colloidal solution containing the metal oxide nanoparticles. Besides the economical aspects, electrospinning of colloids is not efficient compared with spinning of sol–gels, moreover well attachment of the solid nanoparticles is not guaranteed. In this study, reduction of zinc acetate could be performed inside the nylon‐6 electrospun nanofibers; so polymeric nanofibers embedding ZnO nanoflakes were obtained. Typically, zinc acetate/nylon‐6 electrospun nanofibers were treated hydrothermally at 150°C for 1 h. Besides the utilized characterization techniques, PL study affirmed formation of ZnO. The produced nanofibers showed a good antibacterial activity which improves with increasing ZnO content. Overall, the present study opens new avenue to synthesize hybrid nanofibers by a facile procedure. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
The effect of pH on the hydrolytic degradation of poly(ε‐caprolactone)‐block‐poly(ethylene glycol) copolymers
Authors: Loh Xian Jun
Published: May 2012

The in‐vitro hydrolytic behavior of diblock copolymer films consisting of poly(ε‐caprolactone) (PCL) and poly(ethylene glycol) (PEG) was studied at pH 7.4 and pH 9.5 at 37°C. The degradation of these films was characterized at various time intervals by mass loss measurements, GPC, 1H‐NMR, DSC, FTIR, XRD, and SEM. A faster rate of degradation took place at pH 9.5 than at pH 7.4. Analysis of the molecular weight profile during the course of degradation revealed that random chain scission of the ester bonds in PCL predominates at the initial induction phase of polymer degradation. There was also an insignificant mass loss of the films observed. Mass spectroscopy was used to determine the nature of the water soluble products of degradation. At pH 7.4, a variety of oligomers with different numbers of repeating units were present whereas the harsher degradation conditions at pH 9.5 resulted in the formation of dimers. From the results, it can be proposed that a more complete understanding of the degradation behavior of the PCL‐b‐PEG copolymer can be monitored using a combination of physiological and accelerated hydrolytic degradation conditions. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis of random or tapered solution styrene–butadiene copolymers in the presence of sodium dodecylbenzene sulfonate as a polar modifier
Authors: Halasa Adel F. , Jasiunas Chad , Hsu Bill , Henning Steve , Seo Kwang Su
Published: May 2012

Random or tapered solution styrene–butadiene copolymer (SSBR) is very difficult to prepare in an isothermal batch process without the use of polar modifiers because of the diverse reactivity ratios of the styrene and the butadiene in hydrocarbon solvents. In the presence of polar modifiers, the random SSBR can be synthesized by anionic living polymerization with the variety of microstructures, which results in the change of glass transition temperature (Tg). This article will discuss the use of sodium dodecylbenzene sulfonate as a polar modifier in isothermal batch process that controls the microstructure of the SSBR resulting in a random as well as tapered SSBR with low Tg (−67°C to −80°C). The Tg of SSBR was controlled by the styrene content rather than the microstructure of polybutadiene. Physical properties of SSBR compounding were discussed for tire tread applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Novel polymer electrolyte membranes based on semi‐interpenetrating blends of poly(vinyl alcohol) and sulfonated poly(ether ether ketone)
Authors: Kanakasabai P. , Deshpande Abhijit P. , Varughese Susy
Published: May 2012

In this work, the properties of novel ionic polymer blends of crosslinked and sulfonated poly(vinyl alcohol) (PVA) and sulfonated poly(ether ether ketone) (SPEEK) are investigated. Crosslinking and sulfonation of PVA were carried out using sulfosuccinic acid (SSA) in the presence of dispersed SPEEK to obtain semi‐interpenetrating network blends. PVA–SSA/SPEEK blend membranes of different compositions were studied for their ion‐exchange capacity, proton conductivity, water uptake, and thermal and mechanical properties. The hydrated blend membranes show good proton conductivities in the range of 10−3 to 10−2 S/cm. When compared with pure component membranes, the PVA–SSA/SPEEK blend membranes also exhibit improvement in tensile strength, tensile modulus, and delay in the onset of thermal and chemical degradation. Semi‐interpenetrating nature of the blends is established from morphology and dynamic mechanical analysis. Morphology of the membranes was studied using scanning electron microscopy after selective chemical treatment. The dynamic mechanical properties of the membranes are examined to understand the miscibility characteristics of the blends. The relative proportions of PVA and SPEEK and the degree of crosslinking of PVA–SSA are important factors in determining the optimum properties for the blend. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
New insights in dispersion mechanisms of carbon black in a polymer matrix under shear by rheo‐optics
Authors: Collin Véronique , Boudimbou Innocent , Peuvrel‐Disdier Edith
Published: May 2012

The dispersion behavior of different carbon black grades was investigated in a common elastomer matrix under shear using a transparent plate‐and‐plate counter‐rotating shear cell coupled with an optical microscope. The objective was to investigate the effect of carbon black intrinsic characteristics (specific area and structure) on dispersion mechanisms. Shear conditions were selected to study independently erosion and rupture mechanisms. The independent study of rupture and erosion mechanisms brings new findings on the respective effect of the filler intrinsic characteristics on each mechanism: (a) Rupture is a sudden mechanism occurring above a critical shear stress, which depends on the pellet size. The rupture criterion appears not to depend on the carbon black specific area or the structure. (b) Erosion proceeds via the detachment of a fixed eroded volume per strain unit and is driven by the applied shear stress and strain. Erosion is a local mechanism. The erosion rate depends on the carbon black characteristics. Faster erosion was measured for a carbon black with a higher structure at equivalent specific area or with a lower specific area at equivalent structure. This in situ characterization of dispersion mechanisms highlights that the effect of the carbon black characteristics on the two main dispersion mechanisms (rupture and erosion) is completely different. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Poly(ε‐caprolactone) composites containing gentamicin‐loaded β‐tricalcium phosphate/gelatin microspheres as bone tissue supports
Authors: Sezer Umran Aydemir , Aksoy Eda Ayse , Hasirci Vasif , Hasirci Nesrin
Published: May 2012

In this work, novel antibacterial composites were prepared by using poly(ε‐caprolactone) (PCL) as the main matrix material, and gentamicin‐loaded microspheres composed of β‐tricalcium phosphate (β‐TCP) and gelatin. The purpose is to use this biodegradable material as a support for bone tissue. This composite system is expected to enhance bone regeneration by the presence of β‐TCP and prevent a possible infection that might occur around the defected bone region by the release of gentamicin. The effects of the ratio of the β‐TCP/gelatin microspheres on the morphological, mechanical, and degradation properties of composite films as well as in vitro antibiotic release and antibacterial activities against Escherichia coli and Staphylococcus aureus were investigated. The results showed that the composites of PCL and β‐TCP/gelatin microspheres had antibacterial activities for both bacteria. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Selective binding of an imprinted polymer resulted from controlling cobalt coordination to nitric oxide
Authors: Zhao Lili , Chen Changbao , Zhou Jie
Published: May 2012

In this article, the binding characteristics of the imprinted polymer P‐1[CoII(salen)] (salen: bis(2‐hydroxybenzaldehyde)ethylenediimine) to nitric oxide (NO) have been reported. P‐1[CoII(salen)] was characterized by Fourier transform infrared analysis, thermogravimetric analysis, and differential scanning calorimetry. Batch‐mode adsorption studies were carried out to investigate binding thermodynamics, kinetics, and selective recognition behavior of P‐1[CoII(salen)] to NO. The kinetics study indicates that binding of the polymer to NO fits the first‐order reaction kinetics with the rate constant k1 of 0.087 min−1. Langmuir and Freundlich equations were used to explain the equilibrium character of P‐1[CoII(salen)] binding to NO. The r2 and χ2 values suggest that total amount of NO bound by P‐1[CoII(salen)] can be best fitted by the Langmuir equation. The binding capacity (Bmax) of P‐1[CoII(salen)] was calculated to be 76.28 μmol/g, very close to the experimental value, 75 μmol/g. The thermodynamics and selectivity experiments showed that the affinity of P‐1[CoII(salen)] to NO was much higher than carbon dioxide (CO2) and oxygen (O2), suggesting that P‐1[CoII(salen)] is a promising functional material for NO storage and NO sensing. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
The effect of curing cycles on curing reactions and properties of a ternary system based on benzoxazine, epoxy resin, and imidazole
Authors: Wang Hongyuan , Zhao Pei , Ling Hong , Ran Qichao , Gu Yi
Published: May 2012

A ternary blend (BEM) of benzoxazine (BA‐a), epoxy resin (E44), and imidazole (M) was prepared to study the effect of different curing cycles on curing reactions and properties of cured resins. Reactivity of two binary blends, E44 and BA‐a, with the catalyst M, was first investigated based on the curing kinetics. Results suggest that E44/M has lower reaction activation energy than BA‐a/M meaning the reaction of E44/M easily proceeds. To further figure out the sequences of the curing reactions of E44, BA‐a, and M in BEM, the curing behaviors of three BEM gels at 80, 140, and 180°C (defined as BEM‐80g, BEM‐140g, and BEM‐180g) were studied by DSC and FTIR techniques. For BEM‐80g, E44/M cured before BA‐a/M. For BEM‐180g, both curing reactions occurred simultaneously and the copolymerization of BA‐a and E44 was promoted. The crosslinked structures of cured BEM with different initial curing temperatures were strongly influenced by the reaction sequences. The Tgs, flexural properties and thermal stability of the copolymers with different curing cycles were compared. Good performance of this ternary system can be obtained by choosing suitable curing cycles. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
A recycling model of excess toluene diisocyanate isomers in the preparation of polyurethane prepolymer
Authors: He Yong , Zhang Xinya , Zhang Xinfang , Huang Hong , Chang Jie , Chen Huanqin
Published: May 2012

Reaction kinetics of dropwise addition of trimethylolpropane (TMP) to toluene diisocyanate (TDI‐80) at various temperatures and initial stoichiometry was studied. The progress of the polymerization reaction was monitored by measuring the concentration of isocyanate groups and TDI isomers by means of backtitration and high performance liquid chromatography (HPLC), respectively. The kinetics of dropwise addition method, compared with the conventional one‐shot method, was well described by a second order equation. This procedure was optimized by comparing the deviations between experimental data and theoretically calculated data. The effects of temperature, initial stoichiometry and TDI isomers on the amount of excess 2,4‐TDI and 2,6‐TDI were investigated. Three commercially available TDI mixtures, 65 : 35, 80 : 20, and 100 : 0 ratio of 2,4‐TDI/2,6‐TDI, respectively, were used. A recycling model of unreacted TDI isomers and solvent was established to reach a stable process and yield polyurethane prepolymer with good reproducibility. This model has been applied in the chemical plant to prepare polyurethane prepolymer with precisely defined chemical compositions in a continuous process. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Fabrication and in vitro investigation of nanohydroxyapatite, chitosan, poly(L‐lactic acid) ternary biocomposite
Authors: Zhang C. Y. , Zhang C. L. , Wang J. F. , Lu C. H. , Zhuang Z. , Wang X. P. , Fang Q. F.
Published: May 2012

The nanohydroxyapatite/chitosan/poly(L‐lactic acid) (HA/CS/PLLA) ternary biocomposites were prepared by blending the hydroxyapatite/chitosan (HA/CS) nanocomposites with poly(L‐lactic acid) (PLLA) solution. Surface modification by grafting D‐, L‐lactic acid onto the HA/CS nanocomposites was designed to improve the bonding with PLLA. The FTIR and 13C‐NMR spectrum confirmed that the oligo(lactic acid) was successfully grafted onto the HA/CS nanocomposites, and the time‐dependent phase monitoring showed that the grafted copolymers were stable. The TEM morphology of the HA/CS/PLLA ternary nanocomposites showed that nano‐HA fibers were distributed homogeneously, compacted closely and wrapped tightly by the CS and PLLA matrix. The ternary biocomposites with the HA content of 60 and 67 wt % exhibited high compressive strength of about 160 MPa and suitable hydrophilicity. The in vitro tests exhibited that the ternary biocomposites have good biodegradability and bioactivity when immersed in SBF solutions. All the results suggested that the n‐HA/CS/PLLA ternary biocomposites are appropriate to application as bone substitute in bone tissue engineering. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Dispersion of nanoclays with poly(ethylene terephthalate) by melt blending and solid state polymerization
Authors: Kim Sung‐Gi , Lofgren Elizabeth A. , Jabarin Saleh A.
Published: May 2012

Melt intercalation of clay with poly(ethylene terephthalate; PET) was investigated in terms of PET chain mobilities, natures of clay modifiers, their affinities with PET, and nanocomposite solid state polymerization (SSP). Twin screw extrusion was used to melt blend PET resins with intrinsic viscosities of 0.48, 0.63, and 0.74 dL/g with organically modified Cloisite 10A, 15A, and 30B montmorillonite clays. Clay addition caused significant molecular weight reductions in the extruded PET nanocomposites. Rates of SSP decreased and crystallization rates increased in the presence of clay particles. Cloisite 15A blends showed no basal spacing changes, whereas the basal spacings of Cloisite 10A and Cloisite 30B nanocomposites increased after melt extrusion, indicating the presence of intercalated nanostructures. After SSP these nanocomposites also exhibited new lower angle X‐ray diffraction peaks, indicating further expansion of their basal spacings. Greatest changes were seen for nanocomposites prepared from the lowest molecular weight PET and Cloisite 30B, indicating its greater affinity with PET and that shorter more mobile PET chains were better able to enter its galleries and increase basal spacing. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Simultaneous interpenetrating network silicone hydrogels prepared by free radical/cationic hybrid polymerization
Authors: Wang Jing Jing , Liu Fang
Published: May 2012

Simultaneous interpenetrating polymer network silicone hydrogels have been prepared by UV‐initiated polymerization of a mixture of methacrylate monomer 2‐methacryloyloxyethyl phosphorylcholine (MPC) and vinyl ether terminated polydimethylsiloxane (VESi) macromonomer. The consumption of each (macro)monomer upon UV‐irradiation was monitored in situ by real‐time infrared spectroscopy. The methacrylate monomer MPC was shown to polymerize faster and more extensively than the vinyl ether terminated macromonomer VESi. Curing experiments performed in the presence of air and under air diffusion‐free conditions indicated that the free radical polymerization of MPC was affected by the oxygen inhibition effect, while the cationic polymerization of VESi was influenced by the atmosphere humidity. The results of the transmission electron microscope studies indicated that the silicone hydrogels were heterogeneous with phase domain sizes less than 10 nm. The physicochemical properties of the silicone hydrogels, such as water content, ion permeability, oxygen permeability, and contact angle were also investigated. The results showed that water content and ion permeability increased with the MPC content in the formulation, and the silicone hydrogels exhibited excellent oxygen permeability with the highest Dk of 255 barrer. The contact angle measurements indicated that the silicone hydrogels possessed hydrophilic surfaces with the lowest water contact angle of 20°. The result of the protein resistance revealed that the amount of protein adsorbed was significantly reduced with the MPC content in the formulation. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Influence of natural and accelerated weathering on performances of photoselective greenhouse films
Authors: Russo Pietro , Acierno Domenico , Marinucci Luca , Greco Antonio , Frigione Mariaenrica
Published: May 2012

The research aims to investigate the effects of natural and accelerated weathering on polyethylene‐based films. At this regard, monolayer films of low density/linear low density polyethylene blends, containing commercially available organic pigments and an UV absorber of the benzophenone type, have been considered. The samples were weathered on field (natural weathering) or using two different artificial procedures: UV lamp and QUV chamber. Conditioned film samples were, then, analyzed by performing several physical tests taking as‐received films as a reference. Rheological measurements showed an increase in viscosity of weathered sample melts as a consequence of photodegradation phenomena, inducing the formation of double bonds and crosslinks. This latter result was also confirmed by gel content measurements. UV–visible spectroscopic tests indicated that in both cases of natural and artificial weathering an increase of the transmittance of films occurred. Tensile tests indicated the increase of films stiffness, especially in case of samples conditioned using the UV lamp, and a large decrease of the strain at break, both in machine and in transverse directions, especially for film weathered using the QUV chamber. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Nerve guidance channels based on PLLA–PTMC biomaterial
Authors: Wach Radoslaw A. , Adamus Agnieszka , Olejnik Alicja K. , Dzierzawska Joanna , Rosiak Janusz M.
Published: May 2012

Biodegradable polymers of poly(lactic acid) (PLLA) and synthesized in‐house poly(trimethylene carbonate) (PTMC) with admixture of water‐soluble methyl cellulose (MC) were used for development of nerve guidance tubes for peripheral nervous system regeneration after injury. Fabrication method involved phase separation of viscous dixane solution of polymers mixture seat on a rod in a proper nonsolvent, which resulted in tubular structure of large porosity. Influence of electron beam sterilization on molecular weight, thermal properties of the polymers, and mechanical performance of the tubes was evaluated. Admixture of hydrophilic MC to synthetic polymers resulted in modification of mechanical properties of the channels. Extraction of MC showed potential of the tubes for releasing water‐soluble bioactive molecules, such as for instance growth factors. Basic in vitro MTT and LDH assays showed no cytotoxic effect of manufactured tubes, therefore, animal experimentations may be considered. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Superporous collagen‐sericin scaffolds
Authors: Lungu Adriana , Albu Madalina G. , Stancu Izabela Cristina , Florea Nicoleta M. , Vasile Eugeniu , Iovu Horia
Published: May 2012

Superporous materials based on two proteins, collagen and sericin were synthesized by freeze‐drying considering various ratios between the two proteins. To evaluate the influence of sericin content on the structure/properties relationship, the obtained scaffolds were further characterized using spectroscopic analysis, thermal, and mechanical techniques. Scanning electron microscopy was used to investigate the morphological structure of the scaffolds and the swelling properties as well as the stability of the scaffolds were also assessed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Applicability of Wu's criterion for brittle–ductile transition of ethylene/1‐octene copolymer toughened polyamide 6
Authors: Hu Yuexin , Feng Yulin , Jiang Yang , Yin Jinghua , Jiang Wei
Published: May 2012

The brittle–ductile transition of ethylene/1‐octene copolymer (POE) toughened polyamide 6 (PA6) was studied at various temperatures. The experimental results show that the critical interparticle distance (IDc) is independent of the POE content, and the POE particle size at lower temperatures, that is, the temperature is much lower than the brittle–ductile transition temperature (T) of PA6. At higher temperatures, however, especially temperatures close to the T, the IDc depends on the POE particle size. This indicates that Wu's criterion for rubber toughening, specifically that “the IDc is a material property of the matrix, independent of rubber volume fraction and particle size,” is inapplicable at higher temperatures for the brittle–ductile transition of the POE toughened PA6. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
The preparation and characterization of hydrophilic macroporous foams from water soluble polymers grafted ultra‐high molecular weight polyethylene
Authors: Aydinli Bahattin , Tincer Teoman
Published: May 2012

Macroporous foams of water soluble polymers grafted ultra‐high molecular weight polyethylene (UHMWPE) were obtained by precipitation of hot xylene gel solutions in ethyl alcohol. The water soluble monomers used for grafting were acrylic acid (AA), methacrylic acid (MAA), acrylamide (AAm), N‐vinylpyrrolidone (NVP), and N‐N‐di‐methyl acrylamide (NNDAm). The morphology of the foams was investigated using the scanning electron microscope (SEM). Significant changes in the morphology and pore size were observed among the foams depending upon the type of grafting water soluble polymers. The porosity of the foams was uniform and varied from 1 to 10 μm. The percentages of the free volume and water uptake of the foams were measured. The foams obtained from grafted UHMWPE had an appreciable water uptake capacity and water could pass through them compared with the water repelling pure UHMWPE foams. The poly(NNDAm)‐grafted UHMWPE yielded markedly better foams than the others. The water soluble polymer‐grafted conventional polymers posses the characteristics of hybrid material where hydrophobic and mechanically strong UHMWPE make up a strong backbone and hydrophilic hydrogel affords biocompatibility. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
The Viability of Perilabyrinthine Osteocytes: A Quantitative Study Using Bulk‐Stained Undecalcified Human Temporal Bones
Authors: Bloch Sune Land , Kristensen Søren Lund , Sørensen Mads Sølvsten
Published: May 2012

Bone remodeling is highly inhibited around the inner ear space, most likely by the anti‐resorptive action of the inner ear cytokine osteoprotegerin (OPG) entering perilabyrinthine bone through the lacuno‐canalicular porosity (LCP). This extracellular signaling pathway depends on the viability of individual osteocytes. The objective of this study was to evaluate the patency of the LCP at different ages. Sixty‐five bulk‐stained undecalcified human temporal bones and 19 ribs were selected to span the ages from the 30th gestational week to 95 years. Osteocytes from inside a 2‐mm wide perilabyrinthine zone of bone were identified by 3D vector calculations and the numerical densities estimated with an optical dissector and compared to age‐matched ribs. From a high fetal count of 90,000 cells/mm3, the density of viable capsular osteocytes declined rapidly to 73,000 cells/mm3 at three years of age, and non‐viable osteocytes increased inversely. After 3 years, this decline/increase continued at a much slower rate. The densities of viable as well as non‐viable osteocytes and the rates of change were much higher in perilabyrinthine bone compared to ribs. Only after the age of 80 years had the density of viable capsular osteocytes declined to the level of ribs. The bi‐phasic osteocyte kinetics reflects different development stages. The high initial density of viable osteocytes may secure a life‐long anatomical route for inner‐ear OPG despite the unique accumulation of non‐viable osteocytes. Clustering of non‐viable osteocytes may cause local aberrations in the signaling system by closure of the LCP. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Investigating the Impact of Chronic Atrazine Exposure on Sexual Development in Zebrafish
Authors: Corvi Margaret M. , Stanley Kerri A. , Peterson Tracy S. , Kent Michael L. , Feist Stephen W. , La Du Jane K. , Volz David C. , Hosmer Alan J. , Tanguay Robert L.
Published: May 2012

Atrazine (ATZ) is a selective triazine herbicide used primarily for preemergent weed control in corn, sorghum, and sugar cane production. It is one of the most widely used herbicides in North America. Some research published over the last decade suggests that chronic exposure to environmentally relevant ATZ concentrations can adversely impact gonadal development and/or sexual differentiation in amphibians and fish, while other studies report no effect, or moderate effects. As a result, contrasting conclusions have been published regarding the potential effects of the herbicide ATZ on aquatic species. Two near‐identical 4‐month studies in 2009 (Study I) and 2010 (Study II) were performed investigating the potential for chronic ATZ exposure to affect zebrafish (Danio rerio) sexual development and differentiation. Zebrafish were chronically exposed to 0, 0.1, 1, 10 μM ATZ or 1 nM 17ß‐estradiol (E2). Fish were histologically examined to assign gender and to evaluate potential impacts of E2 or ATZ on gonadal development. Exposure to E2 consistently resulted in a significantly higher proportion of female fish to normal male fish when compared to unexposed fish (both studies). In both studies, ATZ exposure did not significantly influence the percentage of female or male fish when compared to unexposed fish. A greater percentage of abnormally developed male fish and fish lacking differentiated gonadal tissue was observed in Study II E2 exposures but not in ATZ exposures. Together, these studies indicate that long‐term exposure to ATZ at or above environmentally relevant concentrations does not significantly impact zebrafish gonadal development or sexual differentiation.
Are old males still good males and can females tell the difference?
Authors: Johnson Sheri L. , Gemmell Neil J.
Published: May 2012

Sperm function generally declines with male age. Paradoxically, females of many species still choose to mate with old males rather than young males. Females choosing old mates may suffer reduced fertilization rates and an increased incidence of birth defects in offspring, lowering fitness which may in turn lead to conflict between the sexes. This apparent paradox has generated much interest from theorists, but whether this paradox presents in nature remains equivocal. Empirical studies have found mixed support for both a decline in fertility with male age and age‐based female mate preference. Here, we examine recent evidence for this paradox, identify confounding variables, highlight areas that deserve further investigation, and suggest avenues for future research.
A chemiluminescence sensor array based on nanomaterials for discrimination of teas
Authors: Niu Weifen
Published: May 2012

In recent years, electronic tongue and nose devices have been developed that consist of an array of cross‐responsive sensors. In this study, we report a chemiluminescence (CL) sensor array based on oxidation at twelve different catalytic nanomaterial locations for the discrimination of eight teas. CL response patterns or “fingerprints” were obtained for a given compound on the sensor array and then discriminated through linear discriminant analysis. The experiments demonstrate that the sensor array had excellent differentiability and reversibility. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis and luminescence properties of 2‐(benzylcarbamoyl)phenyl derivatives and their europium complexes
Authors: Guo Dongcai , He Wei , Liu Bang , Gou Lining , Li Ruixia
Published: May 2012

Six novel 2‐(benzylcarbamoyl)phenyl derivatives were synthesized and characterized by 1H‐NMR, mass spectrometry, infrared spectra and elemental analysis. Their europium complexes were prepared and characterized by elemental analysis, EDTA titrimetric analysis, IR and UV spectra as well as molar conductivity measurements. The luminescence properties of these complexes were investigated and results show that 2‐(benzylcarbamoyl)phenyl derivatives possess high selectivity and good coordination with the europium ion. Complex Eu‐2‐(benzylcarbamoyl)phenyl‐2‐phenylacetate showed green luminescence that was emitted by the ligand of 2‐(benzylcarbamoyl)phenyl‐2‐phenylacetate, while other complexes showed the characteristic red luminescence of europium ion and also possessed high luminescence intensity. Copyright © 2012 John Wiley & Sons, Ltd.
The normative and conceptual foundations of a clinical duty to protect
Authors: Quattrocchi Michael R. , Schopp Robert F.
Published: May 2012

The continuing controversy surrounding the Tarasoff inspired duty to protect as developed by the courts and legislatures has not adequately weighed the jurisprudential foundations of such an obligation. The authors argue that the duty's misguided thrust of social control grounded in character and status seriously violates broad principles of political morality underlying the law of social control. They conceptualize an alternative—a clinical duty to protect—that coheres with these underlying values and the limits of professional abilities. They contend that any extra‐clinical intervention on the part of the psychotherapist entails a role transformation requiring independent justification.
Child abuse and the limits of confidentiality: Forewarning practices
Authors: Crenshaw Wesley B. , Lichtenberg James W.
Published: May 2012

Confidentiality is widely considered to be of great importance in psychotherapy. With few exceptions, the breaching of confidentiality is an ethical violation and grounds for litigation. One such exception is the mandated reporting of known or suspected child abuse, representing a legally sanctioned limitation of confidentiality. Because clients generally expect unlimited confidentiality in therapeutic relationships, many therapists have begun to “forewarn” clients as a matter of informed consent. This research report: (a) briefly reviews issues surrounding mandatory reporting and confidentiality as they relate to forewarning, (b) defines and discusses forewarning as contrasted with “informing,” (c) examines state statutes, case law and ethical guidelines relevant to forewarning, and (d) presents a survey of 428 mental health providers (MHPs) on their forewarning practices in which 36.9% forewarned all clients, 36.4% informed clients only upon suspicion of abuse, and 20.6% informed only after receiving a disclosure of abuse. The implications of these findings are discussed.
A philosophical examination of coercion for mental health issues
Authors: Wertheimer Alan
Published: May 2012

This article considers two philosophical questions about coercion and mental disorders: (1) an analytical question, i.e., what is meant by the concept of coercion? (2) a normative question, i.e., what justifies the use of coercion? The article distinguishes between coercion from other forms of power such as inducement, persuasion, and authority. It then considers a range of arguments for the paternalistic use of coercion for the benefit of mentally disordered persons and the use of coercion to restrain mentally disordered dangerous persons.

This article rests on the assumption that there is something to be said for an academic division of labour, that empirical research in mental health and the law can benefit from conceptual clarification and the analysis of normative arguments. In this article I distinguish between two importantly different sorts of questions that we can ask about coercion and then offer some answers to those questions in broad strokes.
Coercive interactions in a psychiatric emergency room
Authors: Lidz Charles W. , Mulvey Edward P. , Arnold Robert P. , Bennett Nancy S. , Kirsch Brenda L.
Published: May 2012

This paper describes the prevalence of coercive and non‐coercive efforts to influence patients' admission decisions in a psychiatric emergency room. The findings are based on previously collected transcripts of the interaction between patients and families and emergency room staff in 405 cases. Although a significant percentage of the patients were involuntarily admitted, otherwise the most prominent pressures were efforts by attending physicians to persuade patients about what would be the most appropriate disposition. However, a detailed qualitative analysis of the interaction suggest that the clinical staffs power to commit patients against their will affects the way all parties interpret the staffs ‘persuasion’ in such a way that it may be understood as quite coercive.
Inclusion, motivation, and good faith: The morality of coercion in mental hospital admission
Authors: Bennett Nancy S. , Lidz Charles W. , Monahan John , Mulvey Edward P. , Hoge Steven K. , Roth Loren H. , Gardner William
Published: May 2012

We administered a semi‐structured interview to 157 patients shortly after their admission to a psychiatric hospital. In the first, and open‐ended, part of the interview, patients were asked to talk about what had been going on in their lives that led to their coming into the hospital. Then, in a more structured format, they were asked more specific details about who was involved, the patients' relationships with those involved, whether any attempts were made to influence the patient to come into the hospital, and whether such attempts were perceived as fair by the patient.

This article presents a qualitative review of the transcripts of a subset of these interviews. It attends specifically to patients' perceptions of the morality of attempts by others—primarily family members, friends and mental health professionals—to influence them to be admitted to the hospital, and of the morality of the process by which these influence attempts resulted in admission.
Two scales for measuring patients' perceptions for coercion during mental hospital admission
Authors: Gardner William , Hoge Steven K. , Bennett Nancy , Roth Loren H. , Lidz Charles W. , Monahan John , Mulvey Edward P.
Published: May 2012

Legal and extra‐legal coercion are pervasive in mental hospital admission and there are sharp disputes about its appropriate role. This article presents two scales for measuring psychiatric patients' perceptions of coercion during hospital admission and reports data on these scales' internal consistency. We measure patients' perceptions of coercion by asking questions, in either an interview or questionnaire format, about their experience of lack of control, choice, influence, and freedom in hospital admission. Patients' responses to questions about their perceptions of coercion were highly internally consistent. The internal consistency of the scale was robust with respect to variation in site, instrument format, patient population, and interview procedure. Correspondence analysis was used to construct two numerical scales of perceived coercion.
Coercion in psychiatric care: Problems of medical ethics in a comprehensive empirical study
Authors: Kjellin Lars , Candefjord Inga‐Lill , Machl Margareta , Westrin Claes‐Göran , Eriksson Kerstin , Ekblom Bengt , Ängfors Gunvor , Axelsson‐Östman Margareta , Östman Olle
Published: May 2012

In a study of involuntary psychiatric care in two Swedish counties psychiatric examinations and interviews were carried out with 100 committed and 99 voluntarily admitted patients, and 155 relatives of these patients were interviewed. Questionnaires were sent to psychiatric staff, health and welfare personnel of primary care and a representative sample of the general public. As a frame of reference, a two‐dimensional model for description and analysis of ethical conflicts was developed. The first dimension specifies the relevant principles of medical ethics and the second specifies the persons involved. The results indicate ethical ‘benefits’ (fulfilment of ethical principles) and ethical ‘costs’ (violation of ethical principles) for both committed and voluntarily admitted patients, as well as for other groups involved. The study shows the need and feasibility of comprehensive studies of coercion, and the need to develop concepts and methods in such studies as well as for quasiexperimental investigations of involuntary psychiatric care.
Motivations for gun possession and carrying among serious juvenile offenders
Authors: Sheley Joseph F. , Wright James D.
Published: May 2012

Though the prevalence of gun possession and carrying among juveniles is now fairly well documented (at least among non‐serious offenders), little research has examined juveniles' reasons for possessing and carrying guns beyond noting that youth who report robbery and assaultive behavior have higher rates of gun and other weapon possession than do non‐violent youth. The present study examines the question of motivation behind gun possession and carrying by criminally‐inclined youths through analysis of survey data collected from juveniles incarcerated in maximum security reformatories. The findings support the popular fear that juvenile offenders are heavily involved in gun‐related crime, though the same findings point to multiple needs and uses for guns. Using a number of measures—reasons for carrying guns, for using them during the commission of crimes, for purchasing them, etc.—it appears that the primary reason for gun possession and carrying is the juvenile's perception of the need to be armed for protection. This is the case even among those who were involved in such predatory crimes as armed robbery prior to incarceration. Thus, legislative attempts to dissuade youth from obtaining guns to commit crimes are likely misplaced, since the guns eventually used in crime are usually obtained for protective purposes. Only when firearms are perceived as no longer needed can we expect a serious drop in gun‐related offenses among youth.
Weapons used by juveniles and adults to kill parents
Authors: Heide Kathleen M.
Published: May 2012

Youths who kill, particularly those who kill their parents, have been a matter of increasing concern in the United States in recent years. Empirical analyses of homicide and parricide cases, however, have been limited. The FBI Supplementary Homicide Report (SHR) Data Base for the 10‐year period 1977–1986 was utilized to investigate which weapons were used by children in the United States to kill male and female parents and stepparents in single victim, single offender situations. Biological parents were analyzed separately from stepparents. Significant differences were found in the weapons used to kill male and female parents, the weapons used by juveniles and adults when killing parents and stepfathers, and the weapons used by both juveniles and adults when killing male as opposed to female victims. The age and gender differences found in relation to weapons used to kill parents were consistent with a physical strength hypothesis. The relationship found between offender age and weapon used strongly suggests that the number of parricides committed by juveniles could be somewhat curtailed if access to firearms, particularly rifles and shotguns, was severely restricted.
Historical, environmental, and behavioral correlates of sexual offending by male adolescents: A critical review
Authors: Aljazireh Laureen
Published: May 2012

This article is a critical review of research on the historical, environmental, and behavioral correlates of sexual offending by male adolescents. Variables considered include: demographics, victimization history, delinquency history, sexual history, family situation, social/relationships, intellectual functioning, and psychopathology. The review concludes with suggestions for future research and implications for treatment, assessment, and prevention of sexual offending behavior by adolescents.
Phage‐derived fully human antibody scFv fragment directed against human vascular endothelial growth factor receptor 2 blocked its interaction with VEGF
Authors: Zhang Juan , Li Haixin , Wang Xiuyun , Qi Haidi , Miao Xiaoniu , Zhang Tao , Chen Guosheng , Wang Min
Published: May 2012

Vascular endothelial growth factor receptor 2 (VEGFR‐2) plays a critical role in tumor angiogenesis. None therapeutic antibodies targeting VEGFR‐2 are available in clinical use. Herein, we describe the screening of a new single‐chain antibody fragment (scFv) targeting extracellular domain 3 of human VEGFR‐2 (kinase insert domain‐containing receptor [KDR]3) from Griffin phage display scFv library. A comprehensive sequence analysis was performed to assign the framework and complementary‐determining regions. The scFv exerted particular binding sites to KDR3 on molecular docking, and the binding affinity was further convinced by binding analysis both in quantitative ELISA and real‐time kinetic determination by biosensors (KD = 40 nM). Finally, the scFv was revealed to inhibit VEGF‐stimulated proliferation of human umbilical vein endothelial cells (HUVECs; IC50 = 5 nM) and to inhibit HUVEC migration significantly at 17 nM. Taken together, our results indicate that we have successfully isolated a scFv which differentially recognizes KDR3 and has potential clinical applications in the treatment of angiogenesis related diseases. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 28: 981–989, 2012
Constructing Risk and Avoiding Need: Findings from Interviews with Social Workers and Police Officers Involved in Safeguarding Work with Migrant Children
Authors: Westwood Joanne L.
Published: May 2012

Previous research illustrates the lack of services and provision for the needs of migrant children; assessments of needs in the early stage of their arrival into the UK have previously been advocated. This paper reports on a qualitative study with officials in agencies working with children at a UK port of entry. Along with a sense of isolation and fragmentation between those agencies involved in this work, there were clear tensions between the safeguarding agendas and practices of the agencies involved. Analysis of interviews with social workers and police officers suggests that there was a lack of confidence and trust between agencies and in multi‐agency approaches to safeguarding children entering the UK. Assessment approaches tend to be risk orientated at the expense of being culturally attuned and children's rights focused. These findings are discussed together with recommendations for further research. Copyright © 2012 John Wiley & Sons, Ltd.

‘Clear tensions between the safeguarding agendas and practices of the agencies involved’

Key Practitioner Message

Initial assessment work with asylum‐seeking/refugee children should be conducted in the child's first language.

Culturally attuned social work practice with children newly arrived into the UK promotes children's rights, this should be the norm, not the exception.

Professionals working with asylum‐seeking/refugee children at ports of entry should assess risk and need.
Painterly rendering techniques: a state‐of‐the‐art review of current approaches
Authors: Hegde Siddharth , Gatzidis Christos , Tian Feng
Published: May 2012

In this publication we will look at the different methods presented over the past few decades which attempt to recreate digital paintings. While previous surveys concentrate on the broader subject of non‐photorealistic rendering, the focus of this paper is firmly placed on painterly rendering techniques. We compare different methods used to produce different output painting styles such as abstract, colour pencil, watercolour, oriental, oil and pastel. Whereas some methods demand a high level of interaction using a skilled artist, others require simple parameters provided by a user with little or no artistic experience. Many methods attempt to provide more automation with the use of varying forms of reference data. This reference data can range from still photographs, video, 3D polygonal meshes or even 3D point clouds. The techniques presented here endeavour to provide tools and styles that are not traditionally available to an artist. Copyright © 2012 John Wiley & Sons, Ltd.