bluuebunny/crossref_metadata_2025 huggingface dataset:
pH‐Responsive Peptide Mimic Shell Cross‐Linked Magnetic Nanocarriers for Combination Therapy
Authors: Barick Kanhu C. , Singh Sarika , Jadhav Neena V. , Bahadur Dhirendra , Pandey Badri N. , Hassan Puthusserickal A.
Published: July 2012

The design and development of water dispersible, pH responsive peptide mimic shell cross‐linked magnetic nanocarriers (PMNCs) using a facile soft‐chemical approach is reported. These nanocarriers have an average size about 10 nm, are resistant to protein adsorption in physiological medium, and transform from a negatively charged to a positively charged form in the acidic environment. The terminal amino acid on the shell of the magnetic nanocarriers allows us to create functionalized exteriors with high densities of organic moieties (both amine and carboxyl) for conjugation of drug molecules. The drug‐loading efficiency of the nanocarriers is investigated using doxorubicin hydrochloride (DOX) as a model drug to evaluate their potential as a carrier system. Results show high loading affinity of nanocarriers for anticancer drug, their sustained release profile, magnetic‐field‐induced heating, and substantial cellular internalization. Moreover, the enhanced toxicity to tumor cells by DOX‐loaded PMNCs (DOX‐PMNCs) under an AC magntic field suggest their potential for combination therapy involving hyperthermia and chemotherapy.
Heat Dissipation of Transparent Graphene Defoggers
Authors: Bae Jung Jun , Lim Seong Chu , Han Gang Hee , Jo Young Woo , Doung Dinh Loc , Kim Eun Sung , Chae Seung Jin , Huy Ta Quang , Van Luan Nguyen , Lee Young Hee
Published: July 2012

In spite of recent successful demonstrations of flexible and transparent graphene heaters, the underlying heat‐transfer mechanism is not understood due to the complexity of the heating system. Here, graphene/glass defoggers are fabricated and the dynamic response of the temperature as a function of input electrical power is measured. The graphene/glass defoggers reveal shorter response times than Cr/glass defoggers. Furthermore, the saturated temperature of the graphene/glass defoggers is higher than for Cr/glass defoggers at a given input electrical power. The observed dynamic response to temperature is well‐fitted to the power‐balance model. The response time of graphene/glass defogger is shorter by 44% than that of the Cr/glass defogger. The convective heat‐transfer coefficient of graphene is 12.4 × 10−4 W cm−2 °C−1, similar to that of glass (11.1 × 10−4 W cm−2 °C−1) but smaller than that of chromium (17.1 × 10−4 W cm−2 °C−1). The graphene‐based system reveals the lowest convective heat‐transfer coefficient due to its ideal flat surface compared to its counterparts of carbon nanotubes (CNTs) and reduced graphene oxide (RGO)‐based systems.
Gel Electrolyte Derived from Poly(ethylene glycol) Blending Poly(acrylonitrile) Applicable to Roll‐to‐Roll Assembly of Electric Double Layer Capacitors
Authors: Huang Cheng‐Wei , Wu Ching‐An , Hou Sheng‐Shu , Kuo Ping‐Lin , Hsieh Chien‐Te , Teng Hsisheng
Published: July 2012

The synthesis of a gelled polymer electrolyte (GPE) using poly(ethylene glycol) blending poly(acrylonitrile) (i.e., PAN‐b‐PEG‐b‐PAN) as a host, dimethyl formamide (DMF) as a plasticizer and LiClO4 as an electrolytic salt for electric double layer capacitors (EDLCs) is reported. The PAN‐b‐PEG‐b‐PAN copolymer in the GPE has a linear configuration for high ionic conductivity and excellent compatibility with carbon electrodes. When assembling the GPE in a carbon‐based symmetric EDLC, the copolymer network facilitates ion motion by reducing the equivalent series resistance and Warburg resistance of the capacitor. This symmetric cell has a capacitance value of 101 F g−1 at 0.125 A g−1 and can deliver an energy level of 11.5 Wh kg−1 at a high power of 10 000 W kg−1 over a voltage window of 2.1 V. This cell shows superior stability, with little decay of specific capacitance after 30 000 galvanostatic charge‐discharge cycles. The distinctive merit of the GPE film is its adjustable mechanical integrity, which makes the roll‐to‐roll assembly of GPE‐based EDLCs readily scalable to industrial levels.
Morphing Soft Magnetic Composites
Authors: Nguyen Vinh Quang , Ahmed Anansa S. , Ramanujan Raju V.
Published: July 2012

Magnet filler–polymer matrix composites (Magpol) are an emerging class of morphing materials. Applications of Magpol can include artificial muscles, drug delivery, adaptive optics and self healing structures. Advantages of Magpol include remote contactless actuation, several actuation modes, high actuation strain and strain rate, self‐sensing and quick response. The actuation modes of Magpol, its dynamic properties, work output and transduction characteristics are described. Analogies between Magpol actuation and phase transformations are presented. As an illustration of Magpol actuation, a proof of concept artificial muscle is presented. Current applications and future prospects are described.
Engineering the Electronic Structure of Graphene
Authors: Zhan Da , Yan Jiaxu , Lai Linfei , Ni Zhenhua , Liu Lei , Shen Zexiang
Published: July 2012

Graphene exhibits many unique electronic properties owing to its linear dispersive electronic band structure around the Dirac point, making it one of the most studied materials in the last 5‐6 years. However, for many applications of graphene, further tuning its electronic band structure is necessary and has been extensively studied ever since graphene was first isolated experimentally. Here we review the major progresses made in electronic structure engineering of graphene, namely by electric and magnetic fields, chemical intercalation and adsorption, stacking geometry, edge‐chirality, defects, as well as strain.
Engineering Plasmonic Gold Nanostructures and Metamaterials for Biosensing and Nanomedicine
Authors: Jin Yongdong
Published: July 2012

The fields of biosensing and nanomedicine have recently witnessed an explosion of interest and progress in the design and study of plasmonic Au nanostructures (p‐AuNSs) or metamaterials geared towards a broad range of biological and biomedical applications. Due to their tunable and versatile plasmonic properties, such artificially engineered p‐AuNSs and materials have the potential to push biosensor sensitivity towards the single‐molecule detection limit, enabling new bioimaging modalities and new analytical techniques and tools capable of single‐molecule detection, analysis and manipulation, and to revolutionize the diagnosis and treatment of many diseases, including cancers. This report summarizes and highlights recent major advances in the emerging field of bioapplication‐oriented engineering of p‐AuNSs and hybrids, focusing on design considerations and ways to carry them out. A brief overview of the optical properties of p‐AuNSs is introduced, and then the importance of plasmonic engineering and future promising research directions and challenges in the field are discussed.
Crafting Semiconductor Organic−Inorganic Nanocomposites via Placing Conjugated Polymers in Intimate Contact with Nanocrystals for Hybrid Solar Cells
Authors: Zhao Lei , Lin Zhiqun
Published: July 2012

Semiconductor organic−inorganic hybrid solar cells incorporating conjugated polymers (CPs) and nanocrystals (NCs) offer the potential to deliver efficient energy conversion with low‐cost fabrication. The CP‐based photovoltaic devices are complimented by an extensive set of advantageous characteristics from CPs and NCs, such as lightweight, flexibility, and solution‐processability of CPs, combined with high electron mobility and size‐dependent optical properties of NCs. Recent research has witnessed rapid advances in an emerging field of directly tethering CPs on the NC surface to yield an intimately contacted CP−NC nanocomposite possessing a well‐defined interface that markedly promotes the dispersion of NCs within the CP matrix, facilitates the photoinduced charge transfer between these two semiconductor components, and provides an effective platform for studying the interfacial charge separation and transport. In this Review, we aim to highlight the recent developments in CP−NC nanocomposite materials, critically examine the viable preparative strategies geared to craft intimate CP−NC nanocomposites and their photovoltaic performance in hybrid solar cells, and finally provide an outlook for future directions of this extraordinarily rich field.
A New Terthiophene‐Thienopyrrolodione Copolymer‐Based Bulk Heterojunction Solar Cell with High Open‐Circuit Voltage
Authors: Jo Jang , Pron Agnieszka , Berrouard Philippe , Leong Wei Lin , Yuen Jonathan D. , Moon Ji Sun , Leclerc Mario , Heeger Alan J.
Published: July 2012

A new semiconducting polymer based on terthiophene‐thienopyrrolodione alternating building blocks with a deep HOMO energy level (5.66 eV) is presented. The polymer is prepared by a direct heteroarylation polycondensation reaction, which is a low‐cost and green alternative to the standard Stille coupling reaction and thus avoids any use of toxic stannyl derivatives. Integrating the polymer into bulk heterojunction solar cells with [6,6]‐phenyl C71‐butyric acid methyl ester ([70]PCBM) leads to a PCE of over 6% and a high open‐circuit voltage of up to 0.94 V. To obtain these results a unique processing additive, 1‐chloronaphthalene, is used, and a relatively low concentration of [70]PCBM is used in the blend solution.
Edelmetall‐Nanokristalle mit konkaven Oberflächen: Synthese und Anwendungen
Authors: Zhang Hui , Jin Mingshang , Xia Younan
Published: July 2012

Metallische Nanokristalle mit konkaven Oberflächen sind aufgrund ihrer hoch indizierten Flächen, Oberflächenvertiefungen und scharfen Ecken und Kanten für viele Anwendungen in der Katalyse, Plasmonik und oberflächenverstärkten Spektroskopie interessant. Zwei wesentliche Fragen stehen mit dieser neuartigen Klasse von Nanokristallen in Zusammenhang: 1) Wie erzeugt man eine konkave Oberfläche mit negativer Krümmung, die wegen ihres höheren Energiegehalts im Vergleich zur konvexen Oberfläche thermodynamisch benachteiligt ist? 2) Wie stabilisiert man die Morphologie eines Nanokristalls mit konkaven Strukturen an der Oberfläche? In jüngster Zeit wurden mehrere Protokolle zur Synthese von Edelmetall‐Nanokristallen mit konkaven Oberflächen entwickelt. Dieser Aufsatz fasst diese Entwicklungen mit dem Ziel zusammen, neue Einblicke in die Kristallwachstumsmechanismen zu gewinnen. Wir konzentrieren uns auf zwei allgemeine Strategien: 1) ortsspezifisches Ablösen von Atomen durch Ätzvorgänge und galvanischen Austausch und 2) richtungskontrolliertes Überwachsen durch flächenselektives Capping, kinetische Kontrolle und templatgelenkte Epitaxie. Wir beschreiben außerdem die katalytischen und elektrokatalytischen Eigenschaften konkaver Nanokristalle.
Assessment and characterization of antifungal and antialgal performances for biocide‐enhanced linear low‐density polyethylene
Authors: Gitchaiwat Atthapong , Kositchaiyong Apisit , Sombatsompop Kwannate , Prapagdee Benjaphorn , Isarangkura Khokhwan , Sombatsompop Narongrit
Published: July 2012

In this work, four biocides were used for the purpose of growth inhibition of fungi and algae in linear low‐density polyethylene (LLDPE) specimens. Benzimidazol‐2‐yl‐carbamicacid methyl ester [carbendazim (CB)], 5‐chloro‐2‐(2,4‐dichlorophenoxy)phenol [triclosan (TS)], and 3‐iodo‐2‐propynyl N‐butylcarbamate [iodopropynyl butylcarbamate (IPBC)] were used as antifungal agents, and 2‐methylthio‐4‐ethylamino‐6‐tert‐butylamino‐triazin‐1,3,5 [terbutryn (TT)] was used as an antialgal agent. Antifungal performance was evaluated by disk diffusion and dry weight techniques, and antialgal activities were carried out by disk diffusion and chlorophyll A methods. Aspergillus niger TISTR 3245 and Chlorella vulgaris TISTR 8580 were used as the testing fungus and alga, respectively. The experimental results suggested that the wettabilities of LLDPE specimens changed with the incorporation of CB, TS, IPBC, and TT biocides without significant changes in chemical structures and mechanical properties of the LLDPE. IPBC with the recommended content of 10,000 ppm was found to give the most satisfactory growth inhibition of A. niger. Antifungal performance evaluations were dependent on the testing methods used, whereas those for antialgal activity were not. The optimum concentration of TT agent for effective killing of C. vulgaris was 750 ppm; this loading could be reduced from 750 to 250 ppm by the addition of either TS or IPBC agent. TS and IPBC could be used as antialgal promoters in the LLDPE specimens. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Thermal expansivity of chicken feather fiber reinforced epoxy composites
Authors: Zhan Mingjiang , Wool Richard P.
Published: July 2012

Thermal expansivity of chicken feather fibers (CFFs) was studied using thermomechanical analysis for composite applications. CFFs have negative coefficient of thermal expansion (CTE) values in the axial direction at different temperature due to its semicrystalline structure. CFFs have a positive CTE value in the radial direction. The CTE values of epoxy/CFF composites can be predicted by the rule of mixing. CTE values of epoxy/CFF composites in the in‐plane direction at various fiber content and temperature have been fully studied and the results can be used in composite design. We can use CFFs in composite materials to control the overall CTE of the composites to reduce the CTE mismatch between the composites and other components. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Orientation microstructure and properties of poly(propylene carbonate)/poly(butylene succinate) blend films
Authors: Chen G. J. , Wang Y. Y. , Wang S. J. , Xiao M. , Meng Y.Z.
Published: July 2012

The blends of high molecular weight poly(propylene carbonate) (PPC) and poly(butylene succinate) (PBS) were melt blended using triphenylmethane triisocyanate (TTI) as a reactive coupling agent. TTI also serves as a compatibilizer for the blends of PPC and PBS. The blend containing 0.36 wt % TTI showed that the optimal mechanical properties were, therefore, calendared into films with different degrees of orientation. The calendering condition, degree of orientation, morphologies, mechanical properties, crystallization, and thermal behaviors of the films were investigated using wide‐angle X‐ray diffraction, scanning electron microscopy, tensile testing, and differential scanning calorimetry (DSC) techniques. The result showed that the as‐made films exhibited obvious orientation in machine direction (MD). Both tensile strength in MD and the tear strength in transverse direction (TD) increased with increasing the degree of orientation. The orientation of the film also increased the crystallinity and improved the thermal properties of the PPC/PBS blend films. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Two courses in the nonisothermal primary crystallization of poly(butylene terephthalate)
Authors: Wang Xi , Zhang Xingyuan , Zhang Long
Published: July 2012

Nonisothermal crystallization behavior of poly(butylene terephthalate) (PBT) was investigated by means of differential scanning calorimetry. The nonisothermal crystallization kinetic process was analyzed and relative kinetic parameters were obtained with the Avrami and Liu–Mo equations. The results demonstrate a heterogeneous nucleation mechanism. It was found that the nonisothermal primary crystallization of PBT was composed of two courses. Course I corresponded to the two‐dimensional formation process of the lamellae, and the corresponding relative crystallinity (Xt) was less than 15%. Course II was concerned with the three‐dimensional growth process of the spherulite, and Xt changed from 15 to 90%. The secondary crystallization began when Xt was greater than 90%. According to the Flynn–Wall–Ozawa equation, the activation energies for course I, course II, and secondary crystallization were calculated to be −120, −210, and −100 kJ/mol, respectively. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effects of high shear stress on the devulcanization of ground tire rubber in a twin‐screw extruder
Authors: Si Hu , Chen Tianju , Zhang Yuncan
Published: July 2012

The devulcanization reactions of ground tire rubber (GTR) and thermoplastic elastomer (TPE) mixtures performed during the melt‐extrusion process through the induction of high shear stress by increases in the screw rotation speeds and reaction temperatures were investigated in this study. The results show that the high shear stress induced crosslink breakage and/or chain scission of GTR; this led to decreases in the gel contents and Mooney viscosities of the devulcanized GTR(DGTR)/TPE blend and decreases in the sizes of the unfused gel particles in the revulcanized blends of styrene–butadiene rubber [SBR/(DGTR/TPE)]. When the main composition of GTR was natural rubber, its allylic unit structures in the main chains were susceptible to degradation. Although the main composition of GTR was SBR, its main chains contained lower contents of double bonds and were more stable; this led to significant changes in the gel contents and Mooney viscosities of the devulcanized blend and in the mechanical properties of the revulcanized SBR/(DGTR/TPE) blend. The ethylene–propylene–diene monomer (EPDM4770) rubber had better compatibility with GTR than the ethylene/1‐octene copolymer and also had a higher molecular weight than that of EPDM3745. This led to a lower gel content and a higher Mooney viscosity in the devulcanized blend and higher mechanical properties in the revulcanized SBR/(DGTR/EPDM4770) blend. The alkylphenol polysulfide 420 and 450 accelerated the devulcanization reaction and prevented the crosslinking reaction; this led to significant increases in the mechanical properties of the revulcanized SBR/(DGTR/TPE) blend. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Preparation of functionalized lignin beads from oak wood alkaline lignin
Authors: Saidane Dorra , Barbe Jean‐Christophe , Birot Marc , Deleuze Hervé
Published: July 2012

Alkaline lignin extracted from oak wood cooperage wastes was chemically modified to prepare beads by suspension polymerization on water without the use of organic solvents. These beads were macroporous and swelled in hydrophilic solvents. They were functionalized under microwaves to be used as scavenging agents in winery applications. The beads prepared by this approach have the advantage of being more acceptable by winemakers than synthetic polymer supports previously reported. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Crystal polymorphism and enhanced dielectric performance of composite nanofibers of poly(vinylidene fluoride) with silver nanoparticles
Authors: Shi Naien , Duan Juanjuan , Su Jie , Huang Fengzhen , Xue Wei , Zheng Chao , Qian Yan , Chen Shufen , Xie Linghai , Huang Wei
Published: July 2012

Composite nanofibers of poly(vinylidene fluoride) (PVF2) with silver nanoparticles are fabricated by electrospinning. According to the X‐ray diffraction patterns and Fourier transform IR (FTIR) spectra, the content of piezoelectric β‐polymorph of PVF2 is enhanced in the composite fibers of PVF2 and silver as compared with the pristine PVF2 raw materials and electrospun nanofibers. The differential scanning calorimeter (DSC) measurement indicates that the composite of PVF2 and silver has higher melting point and crystallization temperature than that of pristine PVF2 nanofibers. Moreover, the existence of silver nanoparticles greatly enhances the dielectric constant of PVF2 nanofibers and keeps a low dielectric loss simultaneously, which mainly relates to the internal fibrous structure of the composite. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Study on influence of terminal structure on mechanical properties of GAP elastomers
Authors: Zhai Jinxian , Shan Zhongqing , Li Jianmin , Li Xiaodong , Guo Xiaoyan , Yang Rongjie
Published: July 2012

To improve mechanical properties of glycidyl azide polymer (GAP) elastomer, primary hydroxyl terminated GAP prepolymer (PH‐GAP) has been synthesized by end‐capping modification of GAP using carbamate reaction. FTIR, 13C‐NMR, GPC results indicate that the functionality, molecular weight, and molecular weight distribution of PH‐GAP are consistent with those of the original GAP. Mechanical tests indicate that mechanical properties of PH‐GAP elastomer are much better than those of GAP elastomer. Swelling tests discover that the apparent molecular weight of the network chain in PH‐GAP elastomer is much less than that of the original GAP elastomer, and PH‐GAP elastomer has much perfect network structure. Network structure defect is the main factor causing inferior mechanical properties, and the GAP prepolymer terminal structure plays an outstanding role in the mechanical properties of its cross‐linked elastomers. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Polyaniline synthesis using hydrofluoric acid as doping agent: Comparative evaluation with polyaniline doped with sulfuric acid
Authors: Silveira F. Z. , Duarte G. W. , Tachinski C. G. , Piletti R. , Fiori J. , Peterson M. , Riella H. G. , Fiori M. A.
Published: July 2012

This work focuses on the comparison between the morphological, chemical, and electrical properties of polyaniline doped with fluoridric and polyaniline, and doped with sulfuric acid. The FT‐IR, XRD, and SEM/EDS results indicate that the use of hydrofluoric acid as doping agent does not provide meaningful changes in the crystalline and morphological structure of polyaniline. Although, the inclusion of F− type counter‐ions from the doping process with HF provide more compact, denser, and with higher electrical conductivity polymeric matrices. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Release of dexamethasone from poly(N‐vinyl pyrrolidone‐co‐n‐hexyl methacrylate) copolymers of controlled hydrophilicity
Authors: Huma Farhat , Akhter Zareen , Zafar‐Uz‐Zaman M. , Yasin Tariq
Published: July 2012

A copolymer system with controlled hydrophilicity has been prepared through copolymerization technique and its capability as controlled drug release carrier is investigated. The effect of copolymer composition on water uptake, thermal properties, and morphology is reported. The water uptake increases with increasing N‐vinyl pyrrolidone content and diffusion of water molecules appears to be non‐Fickian. Dexamethasone has been selected as model drug and its controlled release from selected water stable copolymers follows for more than 1 month. Initial burst release of more than 50% occurs in 7 days. The remaining drug is released in a sustained way upto 37 days. Initial 10 h drug release pattern involves first‐order kinetics (NH73) and zero‐order kinetics (NH55), whereas initial 60% drug release mechanism appears to be non‐Fickian for NH73 (n = 0.71) and Case II transport (n = 1.24) for NH55. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Preparation of carboxymethyl sago pulp hydrogel from sago waste by electron beam irradiation and swelling behavior in water and various pH media
Authors: Pushpamalar Vengidesh , Langford Steven James , Ahmad Mansor , Hashim Kamaruddin , Lim Yau Yan
Published: July 2012

Solutions of carboxymethyl sago pulp (CMSP) of various degree of substitution were irradiated with electron beam of various radiation doses. The gelation dose (Dg) and po/qo ratio (po is degradation density, qo is crosslinking density) is dependent on CMSP concentration and degree of substitution. In the range of concentrations of 10% to 80% (w/v) CMSP with degree of substitutions of 0.4, 0.6, and 0.8, the po/qo ratio decreases with increasing %CMSP showing that crosslinking processes are dominating and increasing the gel network of the CMSP hydrogel. The fourier transform infrared spectra of CMSP hydrogels of degree of substitutions of 0.4, 0.6, and 0.8 with percentage of gel fractions 25, 35, and ≥ 40 show differences in the intensity of the absorption bands at 1020–1100, 1326, and 1422 cm−1 with different degree of substitutions and percentage of gel fraction (%GF) that correspond to different extents of chain scission and crosslinking. The swelling behavior in water shows that CMSP hydrogels could absorb 3500–5300% of water by 1 g of CMSP hydrogel. The ability to absorb water increases with the decrease of degree of substitution and %GF of the CMSP hydrogels. It is also observed that the optimum pH for swelling CMSP hydrogel is at pH 7. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Poly(ethylene terephthalate)/Poly(ethylene glycol‐co‐1,3/1,4‐cyclohexanedimethanol terephthalate)/Clay nanocomposites: Morphology and isothermal crystallization kinetics
Authors: Wu Jyh‐Horng , Yen Ming‐Shien , Kuo M. C. , Wu Chien‐Pang , Leu Ming‐Tsong , Li Chia‐Hao , Tsai F. K.
Published: July 2012

This work prepared poly(ethylene terephthalate)/clay (PET/clay), PET/poly(ethylene glycol‐co‐1,3/1,4‐cyclohexanedimethanol terephthalate) (PET/PETG), and PET/PETG/clay nanocomposites via the twin‐screw extrusion process. The organoclay in PET and PET/PETG matrices are in homogeneous dispersion, and the spacing distances between the platelets in the PET/clay and PET/PETG/clay nanocomposites are larger than 33.9 Å. Differential scanning calorimetry (DSC) and polarizing optical microscope (POM) analyses showed that the inclusion of organoclay significantly increased the crystallinities and melting temperatures of PET/clay and PET/PETG/clay nanocomposites with less time required to undergo isothermal crystallization. These findings imply the occurrence of heterogeneous nucleation. However, amorphous PETG substantially decreased the crystallinity of the crystallizable units of PET. Morphologically, the inclusion of organoclay drove the crystallites of PET from a spherulite with more perfection and less dimension to a larger spherulite. This process was extended from PET/clay to PET/PETG/clay in which the crystallites propagated in two‐dimensional and disc‐like morphology. However, blending PET with amorphous PETG imparted the larger crystallites with relatively distorted Maltese‐cross patterns. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Assessment of resin formulations and determination of the formaldehyde to urea molar ratio by near‐ and mid‐infrared spectroscopy and multivariate data analysis
Authors: Costa Nuno , Amaral Sandrina , Alvim Ricardo , Nogueira Miguel , Schwanninger Manfred , Rodrigues José
Published: July 2012

The molar ratios of formaldehyde (F) to urea (U) of three resin formulations in the range from 0.90 to 1.49 have been analyzed by means of Attenuated Total Reflection‐Fourier Transform Infrared (ATR‐FTIR) spectroscopy and Fourier Transform‐Near‐Infrared (FT‐NIR) spectroscopy. Application of Principal Component Analysis (PCA) to the spectra (MIR and NIR) allowed to separate them according to the molar ratio and to distinguish between two groups of resins. Soft Independent Modeling of Class Analogy (SIMCA) allowed classification of new resin samples with high model distances between the classes. Partial Least Squares Regression (PLS‐R) models based on MIR (NIR) spectra resulted in high coefficients of determination (R2) values, low errors, and high residual prediction deviations (RPD). To confirm the reproducibility of the process and to carefully evaluate twice all multivariate analysis results obtained, different batches of resins have been prepared to have an additional independent sample set. The number of samples required for MIR and possible applications of MIR and NIR spectroscopy in this context including limitations have been discussed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Enhancement of weld line mechanical strength using a novel ejector‐pins compression system
Authors: Nian Shih‐Chih , Huang Ming‐Shyan
Published: July 2012

This study proposes a novel ejector‐pins compression system (EPCS) to improve the mechanical strength of weld lines that are formed in the injection molding process. Weld lines are significant defects that affect injection molding quality, causing the poor appearance and low mechanical strength of injection‐molded parts. In this experiment, several ejector pins are placed intentionally near the weld lines appearing, and are initially sunken beneath the cavity surface to form a reflow trap such that some of the molten plastics are allowed to flow into it during the filling process. These molten plastics are then compressed by the arisen ejector pins. Accordingly, the compressed molten plastics reflow through the weld lines, disordering the molecular orientation. Experimental verification revealed that the use of an EPCS can efficiently eliminate the orientation of the molecules parallel to the weld line. The specimens' impact strength of using EPCS can increase to between one and two times than that of conventionally injection‐molded. Therefore, this simple and novel method is feasible for greatly improving the mechanical strength of weld lines. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Fabrication and characterization of mesoporous carbon nanosheets using halloysite nanotubes and polypyrrole via a template‐like method
Authors: Liu Yushan , Cai Qiang , Li Hengde , Zhang Jianmin
Published: July 2012

A novel synthesis route for mesoporous carbon (MC) nanosheets were developed using halloysite nanotubes (HNTs), a type of natural clay that is structurally and chemically similar to mineral kaolinite, as inorganic matrix and using polypyrrole (PPy) as carbon precursor by a template‐like method. First, PPy/HNT hybrids were prepared by in situ oxidative polymerization. Carbon (C)/HNT hybrids were further obtained by pyrolysis of the PPy/HNT hybrids. MC was obtained after the removal of inorganic template by hydrochloric acid/hydrofluoric acid mixture at the end. Both the C/HNT and the MC were characterized by Fourier transform infrared spectroscopy analysis, X‐ray diffraction, Raman spectra measurement, and high‐resolution transmission electron microscopy. The MC was also characterized with specific surface area (BET). The results showed that the MC obtained was almost amorphous carbon. The increase in the ratio of [HNTs template]/[pyrrole monomer] led to an increase in the BET‐specific surface area. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2013
Offsetting the impact of the marine ornamental trade: a case study of two temperate top shells (Osilinus lineatus and Gibbula umbilicalis) as potential clean‐up crew
Authors: Watson G. J. , Bonner A. , Murray J. M. , Hebblethwaite Z.
Published: July 2012

It is estimated that several million tropical gastropods are exported each year for the marine ornamental trade to become part of a clean‐up crew (those species that have a beneficial function such as controlling nuisance algae) in an aquarium. Collecting non‐tropical species could offset exploitation impacts, reduce shipping costs and increase survival rates due to shorter transport distances. However, these species must be able to survive and function at tropical marine tank temperatures (25 °C).

Two species of intertidal temperate top shell (Osilinus lineatus) and (Gibbula umbilicalis) were acclimated to 25 °C, 27 °C and 29 °C and survivorship compared with ambient (UK summer) conditions for 55 days. Virtually all G. umbilicalis died during the experiment in all elevated temperatures. In contrast, O. lineatus had minimal mortality in all treatments except the 29 °C, which reached 46.7% ±3.3 by day 55.

Locomotor activity and position in relation to the air/water interface were assessed at 25 °C and ambient conditions. All individuals from both species were active and the mean activity score did not differ between treatments. The majority (63–85%) of the individuals of both species also spent their time either submerged or at the air–water interface and those held at 25 °C spent less time on average out of the water.

Nitrocellulose plates impregnated with an algal extract were used to assess grazing of both species at 25 °C compared with ambient temperature. Over 24 h both consumed significant quantities, and no differences in levels were observed between temperatures or species.

Together this evidence shows that O. lineatus survives equally well at standard tropical aquarium temperatures and also continues to function as a clean‐up crew. Collection of this and other non‐tropical species may be an important alternative conservation approach to tropical collection if ethical and management issues are addressed.

Copyright © 2012 John Wiley & Sons, Ltd.
The Gross Anatomy of the Original and Regenerated Tail in the Green Anole (Anolis carolinensis)
Authors: Ritzman Terrence B. , Stroik Laura K. , Julik Emily , Hutchins Elizabeth D. , Lasku Eris , Denardo Dale F. , Wilson‐Rawls Jeanne , Rawls J. Alan , Kusumi Kenro , Fisher Rebecca E.
Published: July 2012

This study investigates the gross anatomy of the original and the regenerated tail in the green anole (Anolis carolinensis). Dissections were conducted on 24 original and 13 regenerated tails. While the extrinsic muscles of the original tail in A. carolinensis are similar to those in other known Anolis lizard species, the extent of the origins of m. caudofemoralis longus and m. caudofemoralis brevis is more restricted. These differences may underlie variation in locomotor performance among anole ecomorphs. The intrinsic muscles of the original tail are also described, confirming previous findings and documenting new details, including muscle origins and insertions and the range of intraspecific variation. A comparison of the intrinsic muscles of the original tail and the regenerated tail muscles reveals key differences, such as the lack of interdigitating muscle segments and intramuscular septa in the regenerated tail. These findings, along with the replacement of interlocking vertebrae with a stiff, cartilaginous rod, suggest that important functional differences exist between the original and regenerated tail. In particular, the regenerated tail is predicted to be less capable of coordinated, fine movements. Studies of the physical properties and range of motion of the original and regenerated tail are required to test this hypothesis. This atlas of tail anatomy in A. carolinensis represents a key resource for developmental and genetic studies of tail regeneration in lizards, as well as studies of anole evolution and biomechanics. Anat Rec,, 2012. © 2012 Wiley Periodicals, Inc.
Computer‐based learning: Interleaving whole and sectional representation of neuroanatomy
Authors: Pani John R. , Chariker Julia H. , Naaz Farah
Published: July 2012

The large volume of material to be learned in biomedical disciplines requires optimizing the efficiency of instruction. In prior work with computer‐based instruction of neuroanatomy, it was relatively efficient for learners to master whole anatomy and then transfer to learning sectional anatomy. It may, however, be more efficient to continuously integrate learning of whole and sectional anatomy. A study of computer‐based learning of neuroanatomy was conducted to compare a basic transfer paradigm for learning whole and sectional neuroanatomy with a method in which the two forms of representation were interleaved (alternated). For all experimental groups, interactive computer programs supported an approach to instruction called adaptive exploration. Each learning trial consisted of time‐limited exploration of neuroanatomy, self‐timed testing, and graphical feedback. The primary result of this study was that interleaved learning of whole and sectional neuroanatomy was more efficient than the basic transfer method, without cost to long‐term retention or generalization of knowledge to recognizing new images (Visible Human and MRI). Anat Sci Educ. © 2012 American Association of Anatomists.
Diastereoselective Total Synthesis of (±)‐Schindilactone A, Part 2: Construction of the Fully Functionalized CDEFGH Ring System
Authors: Li Yong , Chen Zhi‐Xing , Xiao Qing , Ye Qin‐Da , Sun Tian‐Wen , Meng Fan‐Ke , Ren Wei‐Wu , You Lin , Xu Ling‐Min , Wang Yue‐Fan , Chen Jia‐Hua , Yang Zhen
Published: July 2012

The successful synthesis of the highly complex model compound (2) of the CEFGH ring system of schindilactone A (1) is described. Several synthetic methodologies were developed and applied to achieve this goal, including ring‐closing metathesis (RCM) and Co–thiourea‐catalyzed Pauson–Khand reactions. Furthermore, two independent approaches were developed for the construction of the GH ring of model compound 2, the key steps of which included Pd–thiourea‐catalyzed carbonylative annulation, methylation, and sequential RCM/oxa‐Michael‐addition reactions. The chemistry developed herein has provided a greater understanding of the synthesis of schindilactone A (1) and its analogous compounds of the same family.
Diastereoselective Total Synthesis of (±)‐Schindilactone A, Part 3: The Final Phase and Completion
Authors: Ren Wei‐Wu , Chen Zhi‐Xing , Xiao Qing , Li Yong , Sun Tian‐Wen , Zhang Zi‐Yang , Ye Qin‐Da , Meng Fan‐Ke , You Lin , Zhao Ming‐Zhe , Xu Ling‐Min , Tang Ye‐Feng , Chen Jia‐Hua , Yang Zhen
Published: July 2012

The final phase for the total synthesis of (±)‐schindilactone A (1) is described herein. Two independent synthetic approaches were developed that featured Pd–thiourea‐catalyzed cascade carbonylative annulation reactions to construct intermediate 3 and a RCM reaction to make intermediate 4. Other important steps that enabled the completion of the synthesis included: 1) A Ag‐mediated ring‐expansion reaction to form vinyl bromide 17 from dibromocyclopropane 30; 2) a Pd‐catalyzed coupling reaction of vinyl bromide 17 with a copper enolate to synthesize ketoester 16; 3) a RCM reaction to generate oxabicyclononenol 10 from diene 11; 4) a cyclopentenone fragment in substrate 8 was constructed through a Co–thiourea‐catalyzed Pauson–Khand reaction (PKR); 5) a Dieckmann‐type condensation to successfully form the A ring of schindilactone A (1). The chemistry developed for the total synthesis of schindilactone A (1) will shed light on the synthesis of other family members of schindilactone A.
Evidence of Two Key Intermediates Contributing to the Selectivity of P450‐Biomimetic Oxidation of Sulfides to Sulfoxides and Sulfones
Authors: Zhou Xinrui , Chen Xian , Jin Yaqin , Markó Istvan E.
Published: July 2012

A mild process for the selective oxidation of sulfides is in great demand. Therefore, probing the mechanism underlying the biological oxidation of sulfides under ambient conditions may provide valuable insights for the development of such a reaction. Based on porphyrin models of P450 enzymes, evidence of two key intermediates, Int0 and Int1, in this reaction is provided. Spectroscopic studies indicated the formation of a hydroperoxide‐iron(III) species (Int0) upon addition of H2O2. This intermediate proved to be highly selective for sulfoxide production. By contrast, a defined porphyrin oxoiron(IV) cation radical (Int1) directly reacted with sulfoxides, leading selectively to the corresponding sulfones. Interestingly, the available sulfoxides reversibly act as a new axial ligand for Int0 forming a more active species Int0SO. The amount of Int0 increased in the presence of alkyl, aryl, or aromatic sulfides, while Int1 formed in the absence of these sulfides. Thus, sulfoxides and sulfones would selectively form under conditions that favor the corresponding intermediates, which elucidate the biological oxidation pathway.
Quantitative analyses of individual sugars in mixture using FRET‐based biosensors
Authors: Ha Jae‐Seok , Gam Jongsik , Choi Su‐Lim , Oh Ki‐Hoon , Ro Hyeon‐Su , Song Jae Jun , Shin Chul Soo , Lee Seung‐Goo
Published: July 2012

Molecular biosensors were developed and applied to measure individual sugars in biological mixtures such as bacterial culture broths. As the sensing units, four sugar‐binding proteins (SBPs for allose, arabinose, ribose, and glucose) were selected from the Escherichia coli genome and connected to a cyan fluorescent protein and yellow fluorescent protein via dipeptide linkers (CFP‐L‐SBP‐YFP). The putative sensors were randomized in the linker region (L) and then investigated with regard to the intensity of fluorescence resonance energy transfer on the binding of the respective sugars. As a result, four representatives were selected from each library and examined for their specificity using 16 available sugars. The apparent dissociation constants of the allose, arabinose, ribose, and glucose sensors were estimated to be 0.35, 0.36, 0.17, and 0.18 μM. Finally, the sugar sensors were applied to monitor the consumption rate of individual sugars in an E. coli culture broth. The individual sugar profiles exhibited a good correlation with those obtained using an HPLC method, confirming that the biosensors offer a rapid and easy‐to‐use method for monitoring individual sugars in mixed compositions. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Laccase for biobleaching of eucalypt kraft pulp by means of a modified industrial bleaching sequence
Authors: Moldes D. , Vidal T.
Published: July 2012

Biobleaching of kraft pulp is a possible application of laccase, but it has not been described in detail for complete industrial bleaching sequences yet. Therefore, in this work, the biobleaching of Eucalyptus globulus kraft pulp was performed using a modified industrial totally chlorine‐free sequence. The modification consisted in the substitution of an enzymatic delignification stage, based on the application of laccase from Trametes villosa, for the first alkaline extraction one. The enzymatic stage was performed with several synthetic and natural mediators, namely 1‐hydroxybenzotriazole (HBT), violuric acid (VA), methyl syringate, and syringaldehyde. Several pulp properties were analyzed after each stage of the bleaching process—kappa number, ISO brightness, viscosity, and optical properties of CIEL*a*b* system. The new biobleaching sequence improved the pulp properties, in comparison to the conventional bleaching sequence, if HBT or VA was used as mediators. VA was selected as the best mediator of those tested and the effect of its concentration in the enzymatic stage was subsequently studied. Reducing the initial concentration by 30%, the same pulp quality was obtained, but if the reduction attained 60%, an important decrease in pulp integrity was detected. The modified bleaching sequence could improve the bleached pulp properties (kappa number 10%, ISO brightness 1%, and viscosity 5%) in comparison to the mill sequence. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Synthesis of monoacylglycerol containing pinolenic acid via stepwise esterification using a cold active lipase
Authors: Pyo Young‐Gil , Hong Seung In , Kim Yangha , Kim Byung Hee , Kim In‐Hwan
Published: July 2012

High purity monoacylglycerol (MAG) containing pinolenic acid was synthesized via stepwise esterification of glycerol and fatty acids from pine nut oil using a cold active lipase from Penicillium camembertii as a biocatalyst. Effects of temperature, molar ratio, water content, enzyme loading, and vacuum on the synthesis of MAG by lipase‐catalyzed esterification of glycerol and fatty acid from pine nut oil were investigated. Diacylglycerol (DAG) as well as MAG increased significantly when temperature was increased from 20 to 40°C. At a molar ratio of 1:1, MAG content decreased because of the significant increase in DAG content. Water has a profound influence on both MAG and DAG content through the entire course of reaction. The reaction rate increased significantly as enzyme loading increased up to 600 units. Vacuum was an effective method to reduce DAG content. The optimum temperature, molar ratio, water content, enzyme loading, vacuum, and reaction time were 20°C, 1:5 (fatty acid to glycerol), 2%, 600 units, 5 torr, and 24 h, respectively. MAG content further increased via lipase‐catalyzed second step esterification at subzero temperature. P. camembertii lipase exhibited esterification activity up to −30°C. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Impact of Helix Irregularities on Sequence Alignment and Homology Modeling of G Protein‐Coupled Receptors
Authors: Gonzalez Angel , Cordomí Arnau , Caltabiano Gianluigi , Pardo Leonardo
Published: July 2012

Comparison of the crystal structures of G protein‐coupled receptors (GPCRs) revealed backbone irregularities in the majority of the transmembrane (TM) helices. Among these, wide (π bulge) and tight (310) helical turns on TM2 and TM5 deserve special attention because of their proximity to the ligand binding site. These irregularities are related to residue insertion or deletion (reflected by inclusion of gaps in sequence alignments) accumulated during the evolution of these two helices. These findings have direct implications for the sequence alignments, phylogeny reconstruction, and homology modeling of class A GPCRs.
DYZ‐2‐90, a Novel Neo‐tanshinlactone Ring‐Opened Compound, Induces ERK‐Mediated Mitotic Arrest and Subsequent Apoptosis by Activating JNK in Human Colorectal Cancer Cells
Authors: Wang Li‐Ting , Pan Shiow‐Lin , Chen Tzu‐Hsuan , Dong Yizhou , Lee Kuo‐Hsiung , Teng Che‐Ming
Published: July 2012

Over the past several decades, there has been a considerable and still growing interest in discovering natural products with anticancer potential from traditional Chinese medicine and increasing their anticancer selectivity by chemical modification. In addition, total synthesis of active compounds from natural products can overcome problems related to poor resource availability. DYZ‐2‐90 is a novel ring‐opened compound modified from neo‐tanshinlactone, which is isolated from Chinese medicinal herb tanshen. Both in vitro and in vivo tubulin polymerization assays showed that DYZ‐2‐90 directly bound to microtubules and rapidly induced tubulin depolymerization, inducing ERK‐mediated mitotic arrest and subsequent apoptosis by JNK activation in cancer cells, respectively. These results suggest that the fate of cells that undergo mitotic arrest is dictated by two competing networks activated by DYZ‐2‐90: the cytoprotective ERK pathway and the stress‐related JNK pathway. DYZ‐2‐90 is therefore a novel microtubule‐destabilizing agent and a new drug candidate for cancer therapy. This paper provides a new insight into the model of mitotic cell death, which was proposed in order to elucidate how cancer cells respond to microtubule‐interfering agents and prolonged cell cycle delay.
Evaluating Process Sustainability Using Flowsheet Monitoring
Authors: Barrett Jr W. M. , van Baten J.
Published: July 2012

Environmental metric software can be used to evaluate the sustainability of a chemical based on data from the chemical process that is used to manufacture it. One problem in developing environmental metric software is that chemical process simulation packages typically do not make process flow data available via a mechanism that can be readily accessed by other software packages. While there have been past attempts to develop software that performs environmental sustainability calculations using process simulators, there is no standardized approach for obtaining the process information required to calculate metrics. This paper proposes a standardized mechanism for obtaining process information directly from a process simulation using a strongly integrated interface set, called flowsheet monitoring. The flowsheet monitoring interface provides read‐only access to the thermodynamics, unit operations and streams within the process model, and can be used to obtain the material flow data directly from the simulation. This material flow data can then be used to calculate process‐based environmental metrics.
Self‐Deprotonation and Colorization of 1,3‐Bis(dicyanomethylidene)indan in Polar Media: A Facile Route to a Minimal Polymethine Dye for NIR Fluorescence Imaging
Authors: Heo Jeongyun , Lim Chang‐Keun , Whang Dong Ryeol , Shin Jiyoung , Jeong Seo Young , Park Soo Young , Kwon Ick Chan , Kim Sehoon
Published: July 2012

Colorless 1,3‐bis(dicyanomethylidene)indan is an organic acid (pKa≈3.0) that turns blue in polar media owing to self‐deprotonation. Moreover, its colored conjugate base shows potential as a minimal anionic polymethine dye for probing biomolecules in cells and in vivo through noncovalent complexation and near‐infrared fluorescence signaling.