bluuebunny/crossref_metadata_2025_split huggingface dataset:
Colloidal Self‐Assembly Meets Nanofabrication: From Two‐Dimensional Colloidal Crystals to Nanostructure Arrays
Authors: Zhang Junhu , Li Yunfeng , Zhang Xuemin , Yang Bai 
Published: August 2010

AbstractSelf‐assembly of colloidal microspheres or nanospheres is an effective strategy for fabrication of ordered nanostructures. By combination of colloidal self‐assembly with nanofabrication techniques, two‐dimensional (2D) colloidal crystals have been employed as masks or templates for evaporation, deposition, etching, and imprinting, etc. These methods are defined as “colloidal lithography”, which is now recognized as a facile, inexpensive, and repeatable nanofabrication technique. This paper presents an overview of 2D colloidal crystals and nanostructure arrays fabricated by colloidal lithography. First, different methods for fabricating self‐assembled 2D colloidal crystals and complex 2D colloidal crystal structures are summarized. After that, according to the nanofabrication strategy employed in colloidal lithography, related works are reviewed as colloidal‐crystal‐assisted evaporation, deposition, etching, imprinting, and dewetting, respectively.
Molecular Characterization of Organic Electronic Films
Authors: DeLongchamp Dean M. , Kline R. Joseph , Fischer Daniel A. , Richter Lee J. , Toney Michael F. 
Published: August 2010

AbstractOrganic electronics have emerged as a viable competitor to amorphous silicon for the active layer in low‐cost electronics. The critical performance of organic electronic materials is closely related to their morphology and molecular packing. Unlike their inorganic counterparts, polymers combine complex repeat unit structure and crystalline disorder. This combination prevents any single technique from being able to uniquely solve the packing arrangement of the molecules. Here, a general methodology for combining multiple, complementary techniques that provide accurate unit cell dimensions and molecular orientation is described. The combination of measurements results in a nearly complete picture of the organic film morphology.
Time–temperature–transformation cure diagrams of phenol–formaldehyde and lignin–phenol–formaldehyde novolac resins
Authors: Pérez J. M. , Rodríguez F. , Alonso M. V. , Oliet M. 
Published: August 2010

AbstractIn this study, the time–temperature– transformation (TTT) cure diagrams of the curing processes of several novolac resins were determined. Each diagram corresponded to a mixture of commercial phenol–formaldehyde novolac, lignin–phenol–formaldehyde novolac, and methylolated lignin–phenol–formaldehyde novolac resins with hexamethylenetetramine as a curing agent. Thermomechanical analysis and differential scanning calorimetry techniques were applied to study the resin gelation and the kinetics of the curing process to obtain the isoconversional curves. The temperature at which the material gelled and vitrified [the glass‐transition temperature at the gel point (gelTg)], the glass‐transition temperature of the uncured material (without crosslinking; Tg0), and the glass‐transition temperature with full crosslinking were also obtained. On the basis of the measured of conversion degree at gelation, the approximate glass‐transition temperature/conversion relationship, and the thermokinetic results of the curing process of the resins, TTT cure diagrams of the novolac samples were constructed. The TTT diagrams showed that the lignin–novolac and methylolated lignin–novolac resins presented lower Tg0 and gelTg values than the commercial resin. The TTT diagram is a suitable tool for understanding novolac resin behavior during the isothermal curing process. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis of a novel histidine‐targeting poly(ethylene glycol) and modification of lysozyme
Authors: Sun Jingjing , Song Xiaoda , Tian Hong , Jin Yuhao , Gao Xiangdong , Yao Wenbing 
Published: August 2010

AbstractA simple and highly efficient method was developed to prepare a synthetic poly(ethylene glycol) (PEG) derivative, which can be used for conjugation to histidine residue. This derivative reacted with sodium nitrite and the intermediate 4‐diazo‐N‐mPEG‐benzamide proved to have a good performance for histidine modification of lysozyme. Then the pegylated lysozyme was separated and its bacteriolytic activities were determined. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Film formation and surface properties of enzymatically crosslinked casein films
Authors: Juvonen Helka , Smolander Maria , Boer Harry , Pere Jaakko , Buchert Johanna , Peltonen Jouko 
Published: August 2010

AbstractThe use of renewable materials as barrier material is currently intensively investigated. Biopolymers such as polysaccharides, lipids, and proteins have been studied as barrier materials. Protein‐based films often possess good gas barrier properties, but because of their hydrophilic nature the gas barrier properties are sensitive to humidity. The improvement of the properties of sodium caseinate barrier films in potential packaging applications was studied by investigating the effects of enzymatic treatment and plasticizer on the film properties. Oxidoreductases Trametes hirsuta laccase (ThL) and Trichoderma reesei tyrosinase (TrTyr) were compared with transglutaminase for crosslinking of the sodium caseinate molecules in the films and coatings. All of the studied enzymes were able to crosslink sodium caseinate. Film solubility tests, protein electrophoresis, contact angle measurements, and atomic force microscopy studies showed that TrTyr treatment results in sodium caseinate films and coatings with better overall properties compared to treatment with ThL. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Influence of supercritical CO2 on the interactions between maleated polypropylene and alkyl‐ammonium organoclay
Authors: Liu J. , Thompson M. R. , Balogh M. P. , Speer R. L. , Fasulo P. D. , Rodgers W. R. 
Published: August 2010

AbstractSupercritical carbon dioxide (scCO2) has been proposed as an effective exfoliating agent for the preparation of polymer‐layered silicate nanocomposites, though there is limited fundamental understanding of this mechanism. This study looks at the interactions of this unique green solvent with three maleated polypropylenes of varying anhydride content and molecular size with an alkyl‐ammonium organoclay. Mixtures of compatibilizers and organoclay were melt‐annealed in a high pressure batch vessel at 200°C and subjected to either a blanket of nitrogen or scCO2 at a pressure of 9.7 MPa. The structures and properties of these melt‐annealed mixtures were characterized by X‐ray diffraction, transmission electron microscopy, Fourier Transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, differential scanning calorimetry, and contact angle measurement. The results indicate that the plasticizing influence of scCO2 aided intercalation and exfoliation for intercalants of moderate molecular size and anhydride content which would otherwise have limited diffusion into the clay galleries. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Improved adhesion of TiO2‐based multilayer coating on HDPE and characterization of photocatalysis
Authors: Kasanen Jussi , Suvanto Mika , Pakkanen Tuula T. 
Published: August 2010

AbstractMultilayered photocatalytic TiO2‐based coating was prepared by spin coating on a high‐density polyethylene (HDPE) substrate. The multilayered coating consisted of a polyurethane (PU) barrier layer and two layers of TiO2 nanoparticles bound with PU. The adhesion between the HDPE substrate and protective PU coating was enhanced by oxygen plasma treatment of the substrate. The improved adhesion contributed to the photocatalytic degradation of palmitic acid. Long‐term activity of the photocatalytic coating in degradation of palmitic acid under UV illumination was followed by FTIR‐ATR. The catalytic activity of the coating was maintained in three identical cycles where palmitic acid was added and UV‐irradiated for 6 h. According to FTIR measurements, the palmitic acid was almost completely decomposed after 6 h, but gas chromatography (GC) analysis showed total decomposition to require 12 h UV illumination (∼ 97% of palmitic acid decomposed in 12 h). Study of the degradation of palmitic acid by GC as a function of time indicated that the degradation kinetics was pseudofirst order, and the rate constant obtained was 0.31 h−1. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
A multiprocess eyring model for large strain plastic deformation
Authors: Olley P. , Sweeney J. 
Published: August 2010

AbstractA multiprocess Eyring model is developed with a particular aim of predicting the localized instability occurring in “necking” polymers when cold‐drawn. Differences from using single and multiple Eyring processes are examined using a published data‐set for polypropylene test pieces; it is shown that a four Eyring process model can simultaneously fit both necking stretch ratio and draw force data for uniaxial stretching, whereas with a single process only one measurement could be fitted accurately. The multi process Eyring model is shown to give significantly more accurate predictions than a necking hyperelastic model. The multiprocess model is assessed against the same material undergoing a complex constant‐width elongation. It is shown that agreement is quantitatively good for both drawing force and surface deformation, with some minor differences in transverse force and surface stretch. A pronounced intermittent stretching pattern that is seen on the experimental test piece is replicated by the multiprocess Eyring simulation, but is absent using the hyperelastic model. A method is described to deform a photograph of the original specimen according to a finite element solution. The method is shown to give a clear indication of the accuracy of the model in predicting final form. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
1,3‐Diaryl‐2‐propenones and 2‐Benzylidene‐1,3‐indandiones: A Quest for Compounds Displaying Greater Toxicity to Neoplasms than Normal Cells
Authors: Pati Hari N. , Das Umashankar , Sakagami Hiroshi , Kawase Masame , Chu Qing , Wang Qintao , Stables James P. , Dimmock Jonathan R. 
Published: August 2010

AbstractA series of 1,3‐diaryl‐2‐propenones 2a–j and analogous 2‐benzylidene‐1,3‐indandiones 3a–j were evaluated against various neoplasms and normal cells. In general, greater cytotoxic potencies and selective toxicity to human malignant cells were observed by the compounds in series 2 rather than 3. In particular, 2i emerged as a lead molecule having an average CC50 figure of 8.6 µM and a selective index value of 18. Various physicochemical features of 2a–j were correlated with the cytotoxic potencies to neoplastic cell lines which provide guidelines for expansion of this series of compounds. The enone 2i induced internucleosomal DNA fragmentation and activated caspase‐3 in HL‐60 cells suggesting that one of the ways in which the cytotoxicity of the compounds in series 2 is mediated towards some of the cell lines used in this study is by apoptosis. Neurotoxicity in mice was generally lower in series 2 than 3a–j.
Critical Factors in the Seed‐Assisted Synthesis of Zeolite Beta and “Green Beta” from OSDA‐Free Na+–Aluminosilicate Gels
Authors: Kamimura Yoshihiro , Chaikittisilp Watcharop , Itabashi Keiji , Shimojima Atsushi , Okubo Tatsuya 
Published: August 2010

AbstractOrganic structure‐directing agent (OSDA)‐free synthesis of zeolite beta is a subject of both scientific and industrial interest. Herein, we report a comprehensive investigation into the effects of various parameters on the seed‐assisted crystallization of zeolite beta in the absence of OSDA. The crystallization behavior of “OSDA‐free beta” is strongly governed by the chemical composition of the starting Na+‐aluminosilicate gel as well as by the Si/Al ratios of the calcined beta seed crystals, which are prepared using tetraethylammonium hydroxide (TEAOH). Furthermore, OSDA‐free beta seed crystals can be used to form zeolite beta, termed “green beta”. XRD, scanning electron microscopy, inductively coupled plasma atomic emission spectroscopy, and 27Al magic angle spinning NMR analyses showed that the OSDA‐free beta and green beta were of high purity and crystallinity. The nitrogen adsorption–desorption of OSDA‐free beta and green beta revealed higher surface areas and larger volumes in the micropore region than those of the beta seeds synthesized with OSDA after calcination. These results provide a robust and reliable process for the environmentally friendly production of high‐quality zeolite beta in a completely OSDA‐free Na+‐aluminosilicate system.
In vivo Fluorescence Imaging of Tumors using Molecular Aptamers Generated by Cell‐SELEX
Authors: Shi Hui , Tang Zhiwen , Kim Youngmi , Nie Hailong , Huang Yu Fen , He Xiaoxiao , Deng Ke , Wang Kemin , Tan Weihong 
Published: August 2010

AbstractPoor sensitivity and low specificity of current molecular imaging probes limit their application in clinical settings. To address these challenges, we used a process known as cell‐SELEX to develop unique molecular probes termed aptamers with the high binding affinity, sensitivity, and specificity needed for in vivo molecular imaging inside living animals. Importantly, aptamers can be selected by cell‐SELEX to recognize target cells, or even surface membrane proteins, without requiring prior molecular signature information. As a result, we are able to present the first report of aptamers molecularly engineered with signaling molecules and optimized for the fluorescence imaging of specific tumor cells inside a mouse. Using a Cy5‐labeled aptamer TD05 (Cy5‐TD05) as the probe, the in vivo efficacy of aptamer‐based molecular imaging in Ramos (B‐cell lymphoma) xenograft nude mice was tested. After intravenous injection of Cy5‐TD05 into mice bearing grafted tumors, noninvasive, whole‐body fluorescence imaging then allowed the spatial and temporal distribution to be directly monitored. Our results demonstrate that the aptamers could effectively recognize tumors with high sensitivity and specificity, thus establishing the efficacy of these fluorescent aptamers for diagnostic applications and in vivo studies requiring real‐time molecular imaging.
In vitro study of the effects of ELF electric fields on gene expression in human epidermal cells
Authors: Collard Jean‐Francois , Mertens Benjamin , Hinsenkamp Maurice 
Published: August 2010

AbstractAn acceleration of differentiation, at the expense of proliferation, is observed after exposure of various biological models to low frequency and low amplitude electric and electromagnetic fields. Following these results showing significant modifications, we try to identify the biological mechanism involved at the cell level through microarray screening. For this study, we use epidermis cultures harvested from human abdominoplasty. Two platinum electrodes are used to apply the electric signal. The gene expressions of 38,500 well‐characterized human genes are analyzed using Affymetrix® microarray U133 Plus 2.0 chips. The protocol is repeated on three different patients. After three periods of exposure, a total of 24 chips have been processed. After the application of ELF electric fields, the microarray analysis confirms a modification of the gene expression of epidermis cells. Particularly, four up‐regulated genes (DKK1, TXNRD1, ATF3, and MME) and one down‐regulated gene (MACF1) are involved in the regulation of proliferation and differentiation. Expression of these five genes was also confirmed by real‐time rtPCR in all samples used for microarray analysis. These results corroborate an acceleration of cell differentiation at the expense of cell proliferation. Bioelectromagnetics 32:28–36, 2011. © 2010 Wiley‐Liss, Inc.
ERAD ubiquitin ligases
Authors: Mehnert Martin , Sommer Thomas , Jarosch Ernst 
Published: August 2010

AbstractIn eukaryotic cells terminally misfolded proteins of the secretory pathway are retarded in the endoplasmic reticulum (ER) and subsequently degraded in a ubiquitin‐proteasome‐dependent manner. This highly conserved process termed ER‐associated protein degradation (ERAD) ensures homeostasis in the secretory pathway by disposing faulty polypeptides and preventing their deleterious accumulation and eventual aggregation in the cell. The focus of this paper is the functional description of membrane‐bound ubiquitin ligases, which are involved in all critical steps of ERAD. In the end we want to speculate on how the modular architecture of these entities ensures the specificity of substrate selection and possibly accomplishes the transport of misfolded polypeptides from the ER into the cytoplasm.
The RNA dreamtime
Authors: Kurland Charles G. 
Published: August 2010

AbstractModern cells present no signs of a putative prebiotic RNA world. However, RNA coding is not asine qua nonfor the accumulation of catalytic polypeptides. Thus, cellular proteins spontaneously fold into active structures that are resistant to proteolysis. The law of mass action suggests that binding domains are stabilized by specific interactions with their substrates. Random polypeptide synthesis in a prebiotic world has the potential to initially produce only a very small fraction of polypeptides that can fold spontaneously into catalytic domains. However, that fraction can be enriched by proteolytic activities that destroy the unfolded polypeptides and regenerate amino acids that can be recycled into polypeptides. In this open system scenario the stable domains that accumulate and the chemical environment in which they are accumulated are linked through self coding of polypeptide structure. Such open polypeptide systems may have been the precursors to the cellular ribonucleoprotein (RNP) world that evolved subsequently.
Phlorotannins from Ecklonia cava (Phaeophyceae): Biological activities and potential health benefits
Authors: Wijesekara Isuru , Yoon Na Young , Kim Se‐Kwon 
Published: August 2010

AbstractThe importance of bioactive derivatives as functional ingredients has been well recognized due to their valuable health beneficial effects. Therefore, isolation and characterization of novel functional ingredients with biological activities from seaweeds have gained much attention. Ecklonia cava Kjellman is an edible seaweed, which has been recognized as a rich source of bioactive derivatives mainly, phlorotannins. These phlorotannins exhibit various beneficial biological activities such as antioxidant, anticancer, antidiabetic, anti‐human immunodeficiency virus, antihypertensive, matrix metalloproteinase enzyme inhibition, hyaluronidase enzyme inhibition, radioprotective, and antiallergic activities. This review focuses on biological activities of phlorotannins with potential health beneficial applications in functional foods, pharmaceuticals, and cosmeceuticals. © 2010 International Union of Biochemistry and Molecular Biology, Inc.
Puerarin enhances adipocyte differentiation, adiponectin expression, and antioxidant response in 3T3‐L1 cells
Authors: Lee Ok‐Hwan , Seo Dong‐Ho , Park Cheon‐Seok , Kim Young‐Cheul 
Published: August 2010

AbstractPuerarin, a major isoflavone glycoside from Kudzu root (Pueraria lobata), has been reported to exert antihyperglycemic and antioxidant effects and thus have pharmacological actions in the treatment of diabetes and cardiovascular diseases. We investigated the effects of puerarin on the changes of key gene expression associated with adipocyte differentiation and insulin sensitivity and link to cellular antioxidant response pathways. Puerarin treatment significantly enhanced differentiation of 3T3‐L1 preadipocytes accompanying increased lipid accumulation and glucose‐6‐phosphate dehydrogenase (G6PDH) activity. At a molecular level, puerarin upregulated mRNA expression of peroxisome proliferator‐activated receptor γ (PPARγ) and its target genes, an adipocyte‐specific fatty acid binding protein (aP2) andGLUT4. Puerarin also caused a significant increase in mRNA level of adiponectin, an important insulin‐sensitizing adipocytokine that is downregulated in insulin‐resistant and diabetic states. In addition, treatment with puerarin was found to upregulate mRNA levels ofG6PDH, glutathione reductase, and catalase, all of which are important for endogenous antioxidant responses. These data suggest that the hypoglycemic effects of puerarin can be attributed to the upregulation ofPPARγand its downstream target genes,GLUT4and adiponectin expression, leading to increased glucose utilization. Puerarin may also be effective in preventing the rise of oxidative stress during adipocyte differentiation by increasing endogenous antioxidant responses.
Comparative lipidomic profiling of xylose‐metabolizing S. cerevisiae and its parental strain in different media reveals correlations between membrane lipids and fermentation capacity
Authors: Xia Jinmei , Jones A. Daniel , Lau Ming W. , Yuan Ying‐Jin , Dale Bruce E. , Balan Venkatesh 
Published: August 2010

AbstractPhospholipids (PLs) serve as the foundation for structure and function in most cell membranes. In order to reveal the correlations between PLs composition and fermentation performance of cells, a comparative lipidomics study was carried out using a recombinant xylose fermenting yeast strain Saccharomyces cerevisiae 424A(LNH‐ST) and its parental strain 4124. Profiling of yeast lipids was performed using ultra performance liquid chromatography (UPLC)‐MS/MS, leading to identification of 123 PL species. PL compositions were determined for both strains grown in rich medium (yeast extract peptone), limited medium (yeast nitrogen base), and ammonia fiber expansion pretreated corn stover hydrolysate. Principal component analysis of lipidomic data revealed that the PL profile for both strains varied significantly depending upon cultivating media composition. Further analysis of different classes of PLs revealed that the phosphatidylinositol/phosphatidylserine (PI/PS) ratio was closely related to cell growth rates. Both strains possessed higher phosphatidylcholine (PC) levels at an expense of phosphatidylethanolamine (PE) levels when entering stationary phase and the PC/PE ratios showed consistency with glucose utilization rates. Interestingly, PI synthesis lagged behind when available nutrients were limited, and PI levels were closely correlated with xylose metabolism. Biotechnol. Bioeng. 2011; 108:12–21. © 2010 Wiley Periodicals, Inc.
Characterization of protein release from hydrolytically degradable poly(ethylene glycol) hydrogels
Authors: Zustiak Silviya P. , Leach Jennie B. 
Published: August 2010

AbstractWe present a novel fully hydrophilic, hydrolytically degradable poly(ethylene glycol) (PEG) hydrogel suitable for soft tissue engineering and delivery of protein drugs. The gels were designed to overcome drawbacks associated with current PEG hydrogels (i.e., reaction mechanisms or degradation products that compromise protein stability): the highly selective and mild cross‐linking reaction allowed for encapsulating proteins prior to gelation without altering their secondary structure as shown by circular dichroism experiments. Further, hydrogel degradation and structure, represented by mesh size, were correlated to protein release. It was determined that polymer density had the most profound effect on protein diffusivity, followed by the polymer molecular weight, and finally by the specific chemical structure of the cross‐linker. By examining the diffusion of several model proteins, we confirmed that the protein diffusivity was dependent on protein size as smaller proteins (e.g., lysozyme) diffused faster than larger proteins (e.g., Ig). Furthermore, we demonstrated that the protein physical state was preserved upon encapsulation and subsequent release from the PEG hydrogels and contained negligible aggregation or protein–polymer adducts. These initial studies indicate that the developed PEG hydrogels are suitable for release of stable proteins in drug delivery and tissue engineering applications. Biotechnol. Bioeng. 2011; 108:197–206. © 2010 Wiley Periodicals, Inc.