bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of nucleating agents on the morphologies and performances of poly(vinylidene fluoride) microporous membranes via thermally induced phase separation
Authors: Liu Min , Chen Dong‐Gen , Xu Zhen‐Liang , Wei Yong‐Ming , Tong Meng
Published: July 2012

The effects of nucleating agents on the morphology and performance of poly(vinylidene fluoride) (PVDF) microporous membranes via thermally induced phase separation were investigated. The nucleating agents studied were dicyclohexyl benzene amide (TMB‐5), 2,2‐methylene bis(4,6‐tertiary butyl phenol) sodium phosphate (TMP‐1), and 1,3 : 2,4‐di‐p‐methylbenzylidene sorbitol (DM–LO). Light transmittance experiments and differential scanning calorimetry (DSC) were performed to obtain phase diagrams of PVDF/tributyl citrate/di(2‐ethylhexyl) phthalate/nucleating agent doped solutions. The morphology and performance of the prepared PVDF microporous membranes were characterized with scanning electron microscopy and microfiltration experiments. The results show that the thermodynamics of liquid–liquid phase separation were not affected by the addition of the nucleating agents, but solid–liquid phase separation was influenced. The system with 0.3 wt % TMB‐5 had the fastest crystallization rate and a better nucleation ability. The PVDF microporous membranes had a partly closed, lacy bicontinuous structure with TMP‐1 and DM–LO, whereas the membrane with 0.3 wt % TMB‐5 had an interconnected bicontinuous structure. The pore size distribution became narrower with the addition of nucleating agent. With 0.3 wt % TMB‐5, the membrane had the minimum mean pore size (0.095 μm), a porosity of 80.3%, and a pure water flux of 270 L·m−2·h−1; these values were higher than those of the pure PVDF membrane. The performances of the membranes decreased with additions of TMB‐5 of greater than 0.3 wt %. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Solvent‐free cyanoethylation of selected alcohols using amberlyst A‐21 polymer resin
Authors: Trinadh Mummuluri , Rajasekhar Tota , Bhadru Bhukya , Gopinath Jonnalagadda , Santosh Vundadi , Reddy Basireddy V. Subba , Sainath Annadanam V.Sesha
Published: July 2012

Solvent‐free cyanoethylation of selected alcohols with acrylonitrile (AN) using a weakly basic polymer resin, Amberlyst A‐21 (AA‐21) was studied at 75°C. The conversion of primary alcohols, 1‐octadecanol, hexane‐1,6‐diol, pentaerythritol, but‐2‐yne‐1,4‐diol, N‐methyldiethanolamine, triethanolamine and diethanolamine is higher than secondary alcohols, isopropanol and glycerol in the presence of polymer resin. Of various alcohols, but‐2‐yne‐1,4‐diol gave the product in high conversion (87%) in cyanoethylation with a polymer resin/AN weight ratio of 0.04. The polymer resin showed recycling ability only in two cycles to produce cyanoethylated product from diethanolamine. In case of 1‐octadecanol, hexane‐1,6‐diol, and N‐methyldiethanolamine with AN under similar conditions, no recycling ability was observed. Thermally treated polymer resin at 75°C afforded the product in lower conversion (55%) whereas the same product was obtained in 69% when fresh polymer resin was used in cyanoethylation of 1‐octadecanol. No catalytic effect was observed for polymer resin treated at 100°C. Fourier transform infrared (FTIR) spectra showed CN stretching at 2248 cm−1 for the polymer resin collected after the reaction which was caused by the AN binding on polymer resin during the reaction. As per thermogravimetric curves, 5% weight loss was observed at 201°C for recovered resin and at 161°C for polymer resin treated at 100°C. Scanning electron microscope images confirmed the AN binding on polymer beads after catalytic activity. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Nonisothermal crystallization behaviors of poly(3‐hexylthiophene)/reduced graphene oxide nanocomposites
Authors: Yang Ziping , Lu Hongbin
Published: July 2012

Poly(3‐hexylthiophene) (P3HT)/reduced graphene oxide (rGO) nanocomposites were prepared through in situ reduction of graphene oxide in the presence of P3HT. The nonisothermal crystallization behaviors of P3HT and P3HT/rGO nanocomposites were investigated by differential scanning calorimetry. The Avrami, Ozawa, and Mo models were used to analyze the nonisothermal kinetics. The addition of rGO remarkably increased the crystallization peak temperature and crystallinity of P3HT, but the crystallization half‐time revealed little variation. The crystallization activation energies were calculated by the Kissinger equation. The results suggested that rGO plays a twofold role in the nonisothermal crystallization of P3HT, that is, rGO promotes the crystallization of P3HT as nucleating agent, and meanwhile, it also restricts the motion of P3HT chains. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effect of magnetic field on discotic nematic liquid crystalline polymers under simple shear flow
Authors: Fu Shu‐Fang , Jing‐Bai  , Wang Xuan‐Zhang
Published: July 2012

The effect of magnetic field on the discotic nematic liquid crystalline polymers (LCPs) is analyzed with the extended Doi theory, in which the molecular shape parameter (β) is defined at −1.0. The evolution equation for the probability function of the discotic nematic LCP molecules is solved without any closure approximations. The transition among flow‐orientation modes, such as tumbling, wagging, and aligning defined similar to the rodlike LCPs, is strongly affected by the magnetic fields. The new aligning flow‐orientation mode observed for the rodlike LCPs under magnetic fields also can be investigated in the lower shear rate region. On the other hand, the effect of magnetic fields parallel to the x‐ and y‐axis on the time‐averaged first and second normal stress differences (
$\bar N_1^*$,
$\bar N_2^*$) are also studied. It can be seen that the shear rate regions of the sign changes of
$\bar N_1^*$,
$\bar N_2^*$
are completely contrary to those conclusions achieved for the rodlike LCPs. In addition, the absolute values of
$\bar \eta ^*$
increase with the magnetic field strength in the lower shear rate range owing to the new aligning flow‐orientation mode. Finally, the flow‐phase diagram versus β is also discussed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Thermal response of an electric heating rapid heat cycle molding mold and its effect on surface appearance and tensile strength of the molded part
Authors: Wang Guilong , Zhao Guoqun , Guan Yanjin
Published: July 2012

Rapid heat cycle molding (RHCM) is a newly developed injection molding technology in recent years. In this article, a new electric heating RHCM mold is developed for rapid heating and cooling of the cavity surface. A data acquisition system is constructed to evaluate thermal response of the cavity surfaces of the electric heating RHCM mold. Thermal cycling experiments are implemented to investigate cavity surface temperature responses with different heating time and cooling time. According to the experimental results, a mathematical model is developed by regression analysis to predict the highest temperature and the lowest temperature of the cavity surface during thermal cycling of the electric heating RHCM mold. The verification experiments show that the proposed model is very effective for accurate control of the cavity surface temperature. For a more comprehensive analysis of the thermal response and temperature distribution of the cavity surfaces, the numerical‐method‐based finite element analysis (FEA) is used to simulate thermal response of the electric heating RHCM mold during thermal cycling process. The simulated cavity surface temperature response shows a good agreement with the experimental results. Based on simulations, the influence of the power density of the cartridge heaters and the temperature of the cooling water on thermal response of the cavity surface is obtained. Finally, the effect of RHCM process on surface appearance and tensile strength of the part is studied. The results show that the high‐cavity surface temperature during filling stage in RHCM can significantly improve the surface appearance by greatly improving the surface gloss and completely eliminating the weld line and jetting mark. RHCM process can also eliminate the exposing fibers on the part surface for the fiber‐reinforced plastics. For the high‐gloss acrylonitrile butadiene styrene/polymethyl methacrylate (ABS/PMMA) alloy, RHCM process reduces the tensile strength of the part either with or without weld mark. For the fiber‐reinforced plastics of polypropylene (PP) + 20% glass fiber, RHCM process reduces the tensile strength of the part without weld mark but slightly increases the tensile strength of the part with weld mark. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Ultrastructural and Morphological Characteristics of Human Anterior Cruciate Ligament and Hamstring Tendons
Authors: Zhu Jingxian , Zhang Xin , Ma Yong , Zhou Chunyan , Ao yingfang
Published: July 2012

Hamstring tendons are a commonly used substitute for anterior cruciate ligament (ACL) reconstruction. Ligaments and tendons are similar in composition but the ACL is more complex than hamstring tendons in function and gross morphology, which are highly dependent on its structure and ultrastructure. The purpose of this study was to compare the morphology and ultrastructure of normal human ACL and hamstring tendons, including the cell type and arrangement, expression level of proteoglycans, diameter, and density of collagen fibrils. Twenty semitendinosus or gracilis tendons and 20 ACL specimens were harvested from patients with ACL rupture or osteoarthritis undergoing routine total knee arthroplasty. The specimens were examined histologically and the ultrastructure was observed using scanning and transmission electron microscopy. Semitendinosus and gracilis tendons showed a homogeneous arrangement of collagen fibers and cell type. They had lower fibril density and more widely distributed fibril diameters. In the ACL, there was a more complex arrangement of collagen fibers, distribution of proteoglycans and different cell types. Electronic microscopy demonstrated a combination of parallel, helical and nonlinear networks of ACL fibrils, and fibril diameters were smaller and more nonuniform. This study compared the anatomy of normal human ACL and hamstring tendons, which may provide a standard for evaluating hamstring tendons grafts after ACL reconstruction and may facilitate the application of hamstring tendons in clinical applications. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Cortical Bone Response to the Presence of Load‐Bearing Percutaneous Osseointegrated Prostheses
Authors: Jeyapalina Sujee , Beck James Peter , Bachus Kent N. , Bloebaum Roy D.
Published: July 2012

Although the current percutaneous osseointegrated (OI) prosthetic attachment systems are novel clinical treatments for patients with limb loss, there have only been limited translational studies undertaken to date. To bridge this knowledge gap, from a larger study group of 86 animals that were implanted with a novel percutaneous OI implant construct, 33 sheep were randomly selected from the 0‐, 3‐, 6‐, 9‐ and 12‐month groups for histomorphometric analyses of periprosthetic cortical bone tissue. At necropsy, implanted and nonimplanted limbs were harvested and processed for the evaluation of cortical bone porosity and mineral apposition rate (MAR). The data showed a maximum increase in bone porosity within the first 3 months following implantation and then a progressive reduction in porosity to the baseline steady‐state (“Time 0”) value by 12 months. The data further verified that the MAR increased during the first 6 months of implantation, reaching a plateau between 6 and 9 months, followed by a progressive decline to the baseline steady state. It was concluded that clinical load bearing and falls precautions, taken during the first 3–6 months following percutaneous OI device implantation surgery, could greatly limit bone fractures during this vulnerable time of increasing cortical bone porosity. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Morphometry and Patterns of Lamellar Bone in Human Haversian Systems
Authors: Pazzaglia Ugo E. , Congiu Terenzio , Marchese Marcella , Spagnuolo Francesco , Quacci Daniela
Published: July 2012

The lamellar architecture of secondary osteons (Haversian systems) has been studied with scanning electron microscopy (SEM) in transverse sections of human cortical bone. Na3PO4 etching was used to improve the resolution of the interface between neighboring lamellae and the precision of measurements. These technical improvements permitted testing of earlier morphometry assumptions concerning lamellar thickness while revealing the existence of different lamellar patterns. The mean lamellar thickness was 9.0 ± 2.13 μm, thicker and with a wider range of variation with respect to earlier measurements. The number of lamellae showed a direct correlation with the lamellar bone area, and their thickness had a random distribution for osteonal size classes. The circular, concentrical pattern was the more frequently observed, but spiral and crescent‐moon‐shaped lamellae were also documented. Selected osteons were examined by either SEM or SEM combined with polarized light microscopy allowing comparisons of corresponding sectors of the osteon. The bright bands observed with polarized light corresponded to the grooves observed in etched sections by SEM. The dark bands corresponded to the lamellar surface with the cut fibrils oriented approximately longitudinally along the central canal axis. However, lamellae with large and blurred bright bands could be observed, which did not correspond to a groove observed by SEM. These findings are in contrast with the assumption that all the fibril layers within a lamella are oriented along a constant and unchangeable angle. The different lamellar patterns may be explained by the synchronous or staggered recruitment and activation of osteoblasts committed to the osteon's completion. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
EVALUATION OF IN VITRO AND IN VIVO EFFECTS OF SEMIPURIFIED PROTEINASE INHIBITORS FROM THEOBROMA SEEDS ON MIDGUT PROTEASE ACTIVITY OF LEPIDOPTERAN PEST INSECTS
Authors: Paulillo Luis Cesar Maffei Sartini , Magno Sebbenn Alexandre , de Carvalho Derbyshire Maria Tereza Vitral , Góes‐Neto Aristóteles , de Paula Brotto Marco Aurélio , Figueira Antonio
Published: July 2012

We have characterized in vitro and in vivo effects of trypsin inhibitors from Theobroma seeds on the activity of trypsin‐ and chymotrypsin‐like proteins from Lepidopteran pest insects. The action of semipurified trypsin inhibitors from Theobroma was evaluated by the inhibition of bovine trypsin and chymotrypsin activities determined by the hydrolysis of N‐Benzoyl‐DL‐Arginine‐p‐Nitroanilide (BAPA) and N‐Succinyl‐Ala‐Ala‐Pho‐Phe p‐Nitroanilide (S‐(Ala)2ProPhe‐pNA). Proteinase inhibitor activities from Theobroma cacao and T. obovatum seeds were the most effective in inhibiting trypsin‐like proteins, whereas those from T. obovatum and T. sylvestre were the most efficient against chymotrypsin‐like proteins. All larvae midgut extracts showed trypsin‐like proteolytic activities, and the putative trypsin inhibitors from Theobroma seeds significantly inhibited purified bovine trypsin. With respect to the influence of Theobroma trypsin inhibitors on intact insects, the inclusion of T. cacao extracts in artificial diets of velvet bean caterpillars (Anticarsia gemmatalis) and sugarcane borer (Diatraea saccharalis) produced a significant increase in the percentage of adult deformation, which is directly related to both the survival rate of the insects and oviposition.
Discrepancies between patients and physicians in their perceptions of rheumatoid arthritis disease activity
Authors: Studenic Paul , Radner Helga , Smolen Josef S. , Aletaha Daniel
Published: July 2012

Objective

Patients and physicians often differ in their perceptions of rheumatoid arthritis (RA) disease activity, as quantified by the patient's global assessment (PGA) and by the evaluator's global assessment (EGA). The purpose of this study was to explore the extent and reasons for this discordance.

Methods

We identified variance components for the PGA and EGA in RA patients who were starting therapy with methotrexate in an academic outpatient setting. We analyzed predictors of the observed discrepancy in these measures (calculated as the PGA minus the EGA) and in their changes (calculated as the PGAchange minus the EGAchange).

Results

We identified 646 RA patients, and among them, 77.4% of the variability in the PGA and 66.7% of the variability in the EGA were explainable. The main determinants for the PGA were pain (75.6%), function (1.3%, by Health Assessment Questionnaire), and number of swollen joints (0.5%); those for the EGA were the number of swollen joints (60.9%), pain (4.5%), function (0.6%), C‐reactive protein (0.4%), and the number of tender joints (0.3%). Increased pain led to a discrepancy toward worse patient perception, while increased numbers of swollen joints led to a discrepancy toward worse evaluator perception, both explaining 65% of the discordance between the PGA and the EGA. Likewise, changes in pain scores and numbers of swollen joints proved to be the main determinants for discrepant perceptions of changes in RA disease activity, explaining 34.6% and 12.5% of the discordance, respectively.

Conclusion

The most significant determinants for the cross‐sectional and longitudinal discrepancy between the PGA and the EGA are pain and joint swelling, respectively. Understanding the reasons for a discordant view of disease activity will help to facilitate the sharing of decision‐making in the management of RA.
CO2‐Activation for γ‐Butyrolactones and Its Application in the Total Synthesis of (±)‐Heteroplexisolide E
Authors: Li Suhua , Ma Shengming
Published: July 2012

An efficient nickel(0)‐catalyzed highly regio‐ and stereoselective hydrocarboxylation of homopropargylic alcohols with ZnEt2 in the presence of CO2 (1 atm, balloon) to synthesize α‐alkylidene‐γ‐butyrolactones is described. The catalyst is highly active and can be applied for the synthesis of (optically active) mono‐ or bicyclic α‐alkylidene‐γ‐butyrolactones with excellent regio‐ and stereoselectivity and good functional group tolerance. The potential of the reaction has been demonstrated in the first synthesis of (±)‐heteroplexisolide E.
Ultrafast relaxation dynamics of solvated electrons in water
Authors: Hertwig A. , Hippler H. , Unterreiner A.N. , Vöhringer P.
Published: July 2012

The relaxation dynamics of excess electrons in a water jet between 5 and 70°C have been investigated on an ultrashort timescale. We have probed the transient absorption of the system immediately after UV multiphoton‐ionization with a 266 nm ultrashort laser pulse and a time resolution of about 50 fs. Probe wavelengths ranging from 450 to 1000 nm have been provided by a generated white‐light continuum. The data suggest a superposition of geminate recombination of the solvated electrons with their original counter‐ions and of relaxation into thermal equilibrium. Relaxation into thermal equilibrium is the much faster process and is completed after about 6 ps while the geminate recombination is much slower, temperature independent, and prevails for at least 100 ps. The here postulated interpretation of the data clearly shows that no other transient states than “hot solvated electrons” are required for an understanding of the observed ultrafast dynamics within our time resolution.
Bromide adsorption on silver in alkaline solution: A surface analytical study
Authors: Lützenkirchen‐Hecht D. , Strehblow H.‐H.
Published: July 2012

The electrochemical double layer on Ag in alkaline NaBr solutions was investigated ex situ with x‐ray photo‐electron spectroscopy (XPS). The specimen were removed from the electrolyte with hydrophobic surfaces and under potential control. Potential dependent surface concentrations of the adsorbed anions, cations and the surface excess charge, as well as the amount of adsorbed water were determined. The results obtained for the double layer on Ag in 1 M NaOH+0.1 M NaBr and 1 M NaOH+10−3 M NaBr were compared with alkaline chloride solutions and pure 1 M NaOH. We found evidence for a specific adsorption of hydroxide ions in the basic electrolyte; i.e. the OH−‐surface concentration has to be considered for a proper determination of the cat‐ionic excess charge and the potential of zero charge. Compared to the alkaline chloride solution and pure NaOH, however, an underpotential Ag‐oxide formation below the Nernst‐potential of oxide formation was not observed for the alkaline NaBr solutions, i.e. adsorbed Br− ions inhibit the electrochemical Ag(I) oxide formation.
Swelling properties of colloidal poly(N‐Isopropylacrylamide) microgels in solution
Authors: Kratz Karl , Eimer Wolfgang
Published: July 2012

The volume phase transition of colloidal poly(N‐isopropylacrylamide) microgels with different cross‐linker density has been investigated by dynamic light scattering and scanning electron microscopy. The surfactant‐free emulsion polymerization provides spherical microgel particles with a very narrow size distribution. The amount of cross‐linker has no significant influence on the final hydrodynamic radius in the swollen state at low temperature, but the uniform shape of the dried particles declines for cross‐linker density below 1%. The volume change increases with decreasing connectivity of the gel which is due to topological constraints of the polymer network. While the critical temperature does not vary significantly, a change in the nature of the transition process from a continuous to a more discontinuous volume change was observed.
Orientational dynamics of hydrogen‐bonded liquids – A comparative study of dielectric and nuclear magnetic relaxation in n‐butanol‐tetrachloromethane mixtures
Authors: Nadolny Holger , Volmari Andreas , Weingärtner Hermann
Published: July 2012

Complex dielectric spectra up to 20 GHz are measured at 25°C for n‐butanol tetrachloromethane mixtures. Within this frequency range the spectra can be described by two Debye‐processes. Their relaxation times τ(1)1 and τ(2)1 are compared with the hypothetical single‐particle relaxation time of the dipoles τs1 estimated from deuteron magnetic relaxation rates in these mixtures. The results indicate a collective nature of the primary relaxation time τ(1)1 due to cooperative motion of several molecules. Although not accurate in detail, some theoretical models can reproduce major features of the concentration dependence of τ(1)1. In these models, τ(1)1 is coupled to τs1 via the Kirkwood correlation factor g1 which can be determined independently from the static permittivity. There is no obvious interrelation between τs1 and the secondary relaxation time τ(2)1 the nature of which remains puzzling.
Synthesis and luminescent properties of novel BaGd2O4:Eu3+ scintillating phosphor
Authors: Sun Xin‐Yuan , Wang Wen‐Feng , Sun Shou‐Qiang , Lin Liang‐Wu , Li De‐Yi , Zhou Ling‐Ping
Published: July 2012

BaGd2‐xO4:xEu3+ and Ba1‐yGd1.79‐2yEu0.21Na3yO4 phosphors were synthesized at 1300°C in air by conventional solid‐state reaction method. Phosphors were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence excitation (PLE) spectra, photoluminescence (PL) spectra and thermoluminescence (TL) spectra. Optimal PL intensity for BaGd2‐xO4:xEu3+ and Ba1‐yGd1.79‐2yEu0.21Na3yO4 phosphors at 276 nm excitation were found to be x = 0.24 and y = 0.125, respectively. The PL intensity of Eu3+ emission could only be enhanced by 1.3 times with incorporation of Na+ into the BaGd2O4 host. Enhanced luminescence was attributed to the flux effect of Na+ ions. However, when BaGd2O4:Eu3+ phosphors were codoped with Na+ ions, the induced defects confirmed by TL spectra impaired the emission intensity of Eu3+ ions. Copyright © 2012 John Wiley & Sons, Ltd.
Large multiple transmembrane domain fragments of a G protein‐coupled receptor: Biosynthesis, purification, and biophysical studies
Authors: Potetinova Zhanna , Tantry Subramanyam , Cohen Leah S. , Caroccia Katrina E. , Arshava Boris , Becker Jeffrey M. , Naider Fred
Published: July 2012

To conduct biophysical analyses on large domains of GPCRs, multimilligram quantities of highly homogeneous proteins are necessary. This communication discusses the biosynthesis of four transmembrane and five transmembrane‐containing fragments of Ste2p, a GPCR recognizing the Saccharomyces cerevisiae tridecapeptide pheromone α‐factor. The target fragments contained the predicted four N‐terminal Ste2p[G31‐A198] (4TMN), four C‐terminal Ste2p[T155‐L340] (4TMC), or five C‐terminal Ste2p[I120‐L340] (5TMC) transmembrane segments of Ste2p. 4TMN was expressed as a fusion protein using a modified pMMHa vector in L‐arabinose‐induced Escherichia coli BL21‐AI, and cleaved with cyanogen bromide. 4TMC and 5TMC were obtained by direct expression using a pET21a vector in IPTG‐induced E. coli BL21(DE3) cells. 4TMC and 5TMC were biosynthesized on a preparative scale, isolated in multimilligram amounts, characterized by MS and investigated by biophysical methods. CD spectroscopy indicated the expected highly α‐helical content for 4TMC and 5TMC in membrane mimetic environments. Tryptophan fluorescence showed that 5TMC integrated into the nonpolar region of 1‐stearoyl‐2‐hydroxy‐sn‐glycero‐3‐phospho‐(1′‐rac‐glycerol) micelles. HSQC‐TROSY investigations revealed that [15N]‐labeled 5TMC in 50% trifluoroethanol‐d2/H2O/0.05%–trifluoroacetic acid was stable enough to conduct long multidimensional NMR measurements. The entire Ste2p GPCR was not readily reconstituted from the first two and last five or first three and last four transmembrane domains. © 2012 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 98: 485–500, 2012.
The many facets of MLL1 regulation
Authors: Zhang Pamela , Bergamin Elisa , Couture Jean‐François
Published: July 2012

In the last 20 years, we have witnessed an exponential number of evidences linking the human mixed lineage leukemia‐1 (MLL1) gene to several acute and myelogenous leukemias. MLL1 is one of the founding members of the SET1 family of lysine methyltransferases and is key for the proper control of developmentally regulated gene expression. MLL1 is a structurally complex protein composed of several functional domains. These domains play pivotal roles for the recruitment of regulatory proteins. These MLL1 regulatory proteins (MRPs) dynamically interact with MLL1 and consequently control gene expression. In this review, we summarize recent structural and functional studies of MRPs and discuss emergent structural paradigms for the control of MLL1 activity. © 2012 Wiley Periodicals, Inc. Biopolymers 99: 136–145, 2013.
New biocomposites based on bioplastic flax fibers and biodegradable polymers
Authors: Wróbel‐Kwiatkowska Magdalena , Czemplik Magdalena , Kulma Anna , Żuk Magdalena , Kaczmar Jacek , Dymińska Lucyna , Hanuza Jerzy , Ptak Maciej , Szopa Jan
Published: July 2012

A new generation of entirely biodegradable and bioactive composites with polylactic acid (PLA) or poly‐ε‐caprolactone (PCL) as the matrix and bioplastic flax fibers as reinforcement were analyzed. Bioplastic fibers contain polyhydroxybutyrate and were obtained from transgenic flax. Biochemical analysis of fibers revealed presence of several antioxidative compounds of hydrophilic (phenolics) and hydrophobic [cannabidiol (CBD), lutein] nature, indicating their high antioxidant potential. The presence of CBD and lutein in flax fibers is reported for the first time. FTIR analysis showed intermolecular hydrogen bonds between the constituents in composite PLA+flax fibers which were not detected in PCL‐based composite. Mechanical analysis of prepared composites revealed improved stiffness and a decrease in tensile strength. The viability of human dermal fibroblasts on the surface of composites made of PLA and transgenic flax fibers was the same as for cells cultured without composites and only slightly lower (to 9%) for PCL‐based composites. The amount of platelets and Escherichia coli cells aggregated on the surface of the PLA based composites was significantly lower than for pure polymer. Thus, composites made of PLA and transgenic flax fibers seem to have bacteriostatic, platelet anti‐aggregated, and non‐cytotoxic effect. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Cardiotoxin‐I: An Unexpectedly Potent Insulinotropic Agent
Authors: Nguyen Thi Tuyet Nhung , Folch Benjamin , Létourneau Myriam , Vaudry David , Truong Nam Hai , Doucet Nicolas , Chatenet David , Fournier Alain
Published: July 2012

Insulin secretion from pancreatic β‐cells is a complex process, involving the integration and interaction of multiple external and internal stimuli, in which glucose plays a major role. Understanding the physiology leading to insulin release is a crucial step toward the identification of new targets. In this study, we evaluated the presence of insulinotropic metabolites in Naja kaouthia snake venom. Only one fraction, identified as cardiotoxin‐I (CTX‐I) was able to induce insulin secretion from INS‐1E cells without affecting cell viability and integrity, as assessed by MTT and LDH assays. Interestingly, CTX‐I was also able to stimulate insulin secretion from INS‐1E cells even in the absence of glucose. Although cardiotoxins have been characterized as potent hemolytic agents and vasoconstrictors, CTX‐I was unable to induce direct hemolysis of human erythrocytes or to induce potent vasoconstriction. As such, this newly identified insulin‐releasing toxin will surely enrich the pool of existing tools to study β‐cell physiology or even open a new therapeutic avenue.
Sulfur‐Containing Secondary Metabolites from Arabidopsis thaliana and other Brassicaceae with Function in Plant Immunity
Authors: Bednarek Paweł
Published: July 2012

Biosynthesis of antimicrobial secondary metabolites in response to microbial infection is one of the features of the plant immune system. Particular classes of plant secondary metabolites involved in plant defence are often produced only by species belonging to certain phylogenetic clades. Brassicaceae plants have evolved the ability to synthesise a wide range of sulfur‐containing secondary metabolites, including glucosinolates and indole‐type phytoalexins. A subset of these compounds is produced by the model plant Arabidopsis thaliana. Genetic tools available for this species enabled verification of immune functions of glucosinolates and camalexin (A. thaliana phytoalexin), as well as characterisation of their respective biosynthetic pathways. Current knowledge of the biosynthesis of Brassicaceae sulfur‐containing metabolites suggests that the key event in the evolution of these compounds is the acquisition of biochemical mechanisms originating from detoxification pathways into secondary metabolite biosynthesis. Moreover, it is likely that glucosinolates and Brassicaceae phytoalexins, traditionally considered as separate groups of compounds, have a common evolutionary origin and are interconnected on the biosynthetic level. This suggests that the diversity of Brassicaceae sulfur‐containing phytochemicals reflect phylogenetic clade‐specific branches of an ancient biosynthetic pathway.
Polycyclic Azoniahetarenes: Assessing the Binding Parameters of Complexes between Unsubstituted Ligands and G‐Quadruplex DNA
Authors: Jäger Katharina , Bats Jan W. , Ihmels Heiko , Granzhan Anton , Uebach Sandra , Patrick Brian O.
Published: July 2012

Polycyclic azoniahetarenes were employed to determine the effect of the structure of unsubstituted polyaromatic ligands on their quadruplex‐DNA binding properties. The interactions of three isomeric diazoniadibenzo[b,k]chrysenes (4 a–c), diazoniapentaphene (5), diazoniaanthra[1,2‐a]anthracene (6), and tetraazoniapentapheno[6,7‐h]pentaphene (3) with quadruplex DNA were examined by DNA melting studies (FRET melting) and fluorimetric titrations. In general, penta‐ and hexacyclic azoniahetarenes bind to quadruplex DNA (Kb≈106 M−1) even in the absence of additional functional side chains. The binding modes of 4 a–c and 3 were studied in more detail by ligand displacement experiments, isothermal titration calorimetry, and CD and NMR spectroscopy. All experimental data indicate that terminal π stacking of the diazoniachrysenes to the quadruplex is the major binding mode; however, because of different electron distributions of the π systems of each isomer, these ligands align differently in the binding site to achieve ideal binding interactions. It is proposed that tetraazonia ligand 3 binds to the quadruplex by terminal stacking with a small portion of its π system, whereas a significant part of the bulky ligand most likely points outside the quadruplex structure, and is thus partially placed in the grooves. Notably, 3 and the known tetracationic porphyrin TMPyP4 exhibit almost the same binding properties towards quadruplex DNA, with 3 being more selective for quadruplex than for duplex DNA. Overall, studies on azonia‐type hetarenes enable understanding of some parameters that govern the quadruplex‐binding properties of parent ligand systems. Since unsubstituted ligands were employed in this study, complementary and cooperative effects of additional substituents, which may interfere with the ligand properties, were eliminated.
Tetrasubstituted Phenanthrolines as Highly Potent, Water‐Soluble, and Selective G‐Quadruplex Ligands
Authors: Larsen Anders Foller , Nielsen Mads Corvinius , Ulven Trond
Published: July 2012

Small molecules capable of stabilizing the G‐quadruplex (G4) structure are of interest for the development of improved anticancer drugs. Novel 4,7‐diamino‐substituted 1,10‐phenanthroline‐2,9‐dicarboxamides that represent hybrid structures of known phenanthroline‐based ligands have been designed. An efficient synthetic route to the compounds has been developed and their interactions with various G4 sequences have been evaluated by Förster resonance energy transfer (FRET) melting assays, fluorescent intercalator displacement (FID), electrospray ionization mass spectrometry (ESI‐MS), and circular dichroism (CD) spectroscopy. The preferred compounds have high aqueous solubility and are strong and potent G4 binders with a high selectivity over duplex DNA; thus, they represent a significant improvement over the lead compounds. Two of the compounds are inhibitors of HeLa and HT1080 cell proliferation.
Viability of Möbius Topologies in [26]‐ and [28]Hexaphyrins
Authors: Alonso Mercedes , Geerlings Paul , de Proft Frank
Published: July 2012

Recently, hexaphyrins have emerged as a promising class of π‐conjugated molecules that display a range of interesting electronic, optical, and conformational properties, including the formation of stable Möbius aromatic systems. Besides the Möbius topology, hexaphyrins can adopt a variety of conformations with Hückel and twisted Hückel topologies, which can be interconverted under certain conditions. To determine the optimum conditions for viable Möbius topologies, the conformational preferences of [26]‐ and [28]hexaphyrins and the dynamic interconversion between the Möbius and Hückel topologies were investigated by density functional calculations. In the absence of meso substituents, [26]hexaphyrin prefers a planar dumbbell conformation, strongly aromatic and relatively strain free. The Möbius topology is highly improbable: the most stable tautomer is 33 kcal mol−1 higher in energy than the global minimum. On the other hand, the Möbius conformer of [28]hexaphyrin is only 6.5 kcal mol−1 higher in energy than the most stable dumbbell conformation. This marked difference is due to aromatic stabilization in the Möbius 4n electron macrocycle as opposed to antiaromatic destabilization in the 4n+2 electron system, as revealed by several energetic, magnetic, structural, and reactivity indices of aromaticity. For [28]hexaphyrins, the computed activation barrier for interconversion between the Möbius aromatic and Hückel antiaromatic conformers ranges from 7.2 to 10.2 kcal mol−1, in very good agreement with the available experimental data. The conformation of the hexaphyrin macrocycle is strongly dependent on oxidation state and solvent, and this feature creates a promising platform for the development of molecular switches.
ChemInform Abstract: Synthesis and Tuberculostatic Activity of Novel Diverse Heterocyclic Compounds Derived from Heterocyclic Carbohydrazides and Methyl 2‐Heteroaroylhydrazinecarbodithioates.
Authors: Gobis Katarzyna , Foks Henryk , Augustynowicz‐Kopec Ewa , Napiorkowska Agnieszka
Published: July 2012

Oxadiazoles, thiadiazoles, and triazoles are synthesized by exploiting the high reactivity of methyl heteroaroylhydrazinecarbodithioates such as (IV) which undergo cyclization in alkaline or acidic solution.
ChemInform Abstract: Au‐Catalyzed Asymmetric Formal [3 + 2] Cycloaddition of Isocyanoacetates with Maleimides.
Authors: Padilla Silvia , Adrio Javier , Carretero Juan C.
Published: July 2012

The procedure allows the efficient access to chiral pyrrolopyrrole compounds which can be converted into various derivatives such as (IV) and (VI).
ChemInform Abstract: Efficient Synthesis of 5′‐Fluoroalkoxythiazoles via α‐Bromo‐α‐fluoroalkoxyacetophenones Hantzsch Type Cyclization with Thioureas or Thioamides.
Authors: Sokolenko Taras M. , Davydova Yulia A. , Yagupolskii Yurii L.
Published: July 2012

Addition of dimethoxyphenylethanol (I) to fluoroolefins (II) followed by deprotection of the carbonyl function, α‐bromination, and subsequent treatment of the α‐bromo‐α‐fluoroalkoxyacetophenones (V) with thioureas or thioamides provides access to thiazoles with fluoroalkoxy groups at the 5‐position by means of Hantzsch‐type cyclization.
ChemInform Abstract: Interaction of Quinolines Polyfluorinated on the Benzene Moiety with Sodium and Potassium Amides in Liquid Ammonia.
Authors: Gurskaya Larisa Yu. , Selivanova Galina A. , Shteingarts Vitalij D.
Published: July 2012

Quinolines (I) and (III) react with potassium or sodium amides by adding the NH2‐ ion at the 2‐position of the pyridine fragment to afford the quinolineamines (II) and (IV), resp., upon oxidation of the adducts formed.
ChemInform Abstract: Synthesis of 3‐Substituted 4‐Sulfanyl‐8‐methoxyisoquinolin‐1(2H)‐ones by the Reaction of Ethyl 2‐[Lithio(sulfanyl)methyl]‐6‐methoxybenzoates with Aliphatic and Aromatic Nitriles.
Authors: Kobayashi Kazuhiro , Hashimoto Hiroo , Nakagawa Kazuhiro
Published: July 2012

Intermediates (III), obtained by reaction of ethyl halomethylmethoxybenzoates (I) with sodium thiolates, are deprotonated upon treatment with lithium diisopropylamide to generate the corresponding benzyl anions, which react smoothly with a variety of nitriles to afford satisfactory to very good yields of the desired isoquinolinones (V) and (VII).
ChemInform Abstract: Meerwein′s Reagent Mediated, Significantly Enhanced Nucleophilic Fluorination on Alkoxysilanes.
Authors: Jorapur Yogesh R. , Shimada Toyoshi
Published: July 2012

A novel method is developed to convert alkoxysilanes to the corresponding fluorosilanes in high yields.
ChemInform Abstract: Monoterpene Glucosides from Ziziphora clinopodioides (Labiatae).
Authors: Furukawa Megumi , Oikawa Naoki , Imohata Toru , Makino Mitsuko , Ogawa Shoujiro , Iida Takashi , Fujimoto Yasuo , Kitanaka Susumu
Published: July 2012

The three new monoterpene glucosides ziziphoroside A (I), B (II) and C (III) exhibit only weak inhibitory activity against nitric oxide production by lipopolysaccharide and interferon‐γ activated macrophages, RAW 264.7.
ChemInform Abstract: Search for New Natural Leads. Part 10. Galactolipids from Bauhinia racemosa as a New Class of Antifilarial Agents Against Human Lymphatic Filarial Parasite, Brugia malayi.
Authors: Sashidhara Koneni V. , Singh Suriya P. , Misra Sweta , Gupta Jyoti , Misra‐Bhattacharya Shailja
Published: July 2012

Among the active galactolipids, compound (I) emerge as lead structure active on both forms of lymphatic filarial parasite, Brugia malayi.
ChemInform Abstract: Surface Chemistry of Ruthenium Dioxide in Heterogeneous Catalysis and Electrocatalysis: From Fundamental to Applied Research
Authors: Over Herbert
Published: July 2012

Review: 868 refs.
ChemInform Abstract: Heterocycles in Drugs and Drug Discovery
Authors: Gomtsyan A.
Published: July 2012

Review: 10 refs.
Antibacterial Behavior of Pyridinecarboxylatesilver(I) Complexes
Authors: Abarca Romina , Gomez Grace , Velasquez Carla , Paez Maritza A. , Gulppi Miguel , Arrieta Abel , Azocar Manuel I.
Published: July 2012

FT‐IR spectroscopy of carboxylic groups and viability tests were useful to understand the antibacterial properties of six highly efficient silver(I) pyridinecarboxylate (nicotinic, picolinic and isonicotinic acids) and bipiridinecarboxylate (pyridine‐2,3‐dicarboxylic, pyridine‐2,4‐dicarboxylic and pyridine‐2,5‐dicarboxylic acids) complexes with AgO and AgN bonds against E. coli (ATCC 25922) and Streptococcus agalactiae (ISP 329‐09). The results show a tendency between the nature of AgX (X=oxygen and nitrogen) bonds and the rate or efficiency of antibacterial behavior.
Terpenoids from a Chinese Gorgonian Anthogorgia sp. and Their Antifouling Activities
Authors: Chen Dawei , Liu Dong , Shen Shi , Cheng Wei , Lin Wenhan
Published: July 2012

Chemical examination of a Chinese gorgonian Anthogorgia sp. resulted in the isolation of seven terpenoids, including two new compounds, an rearranged serrulatane‐type diterpenoid anthogorgiene P (1) and a guaiazuene‐based terpenoid anthogorgiene Q (2). Anthogorgiene P (1) contains an unprecedented cubebane nucleus which is rarely found from nature. The structures of new compounds were elucidated on the basis of extensive spectroscopic methods (IR, UV, MS, CD and NMR). Compound 7 showed potent antifouling activity against the larval settlement of Balanus amphitrite, while 1 and 4 possessed moderate inhibition.
Preparation of Ionic Liquid‐based Vilsmier Reagent from Novel Multi‐purpose Dimethyl Formamide‐like Ionic Liquid and Its Application
Authors: Hullio Ahmed Ali , Mastoi G. M.
Published: July 2012

In continuation of research to explore the applied potential of DMF‐like ionic liquid, the ionic liquid version of N,N‐dimethyliminiumchloride (Vilsmier reagent) has been synthesized from DMF‐like ionic liquid and tested effectively for its capacity to achieve more useful organic transformations. The results show that DMF‐like ionic liquid is world's first task specific ionic liquid which has catalyzed numerous diverse type of reaction and is multipurpose in its application. Thus a new term for this DMF‐like ionic liquid has been coined that is DMF‐like "multipurpose" ionic liquid.
On testing for independence between the innovations of several time series
Authors: Duchesne Pierre , Ghoudi Kilani , Rémillard Bruno
Published: July 2012

Test statistics for checking the independence between the innovations of several time series are developed. The time series models considered allow for general specifications for the conditional mean and variance functions that could depend on common explanatory variables. In testing for independence between more than two time series, checking pairwise independence does not lead to consistent procedures. Thus a finite family of empirical processes relying on multivariate lagged residuals are constructed, and we derive their asymptotic distributions. In order to obtain simple asymptotic covariance structures, Möbius transformations of the empirical processes are studied, and simplifications occur. Under the null hypothesis of independence, we show that these transformed processes are asymptotically Gaussian, independent, and with tractable covariance functions not depending on the estimated parameters. Various procedures are discussed, including Cramér–von Mises test statistics and tests based on non‐parametric measures. The ranks of the residuals are considered in the new methods, giving test statistics which are asymptotically margin‐free. Generalized cross‐correlations are introduced, extending the concept of cross‐correlation to an arbitrary number of time series; portmanteau procedures based on them are discussed. In order to detect the dependence visually, graphical devices are proposed. Simulations are conducted to explore the finite sample properties of the methodology, which is found to be powerful against various types of alternatives when the independence is tested between two and three time series. An application is considered, using the daily log‐returns of Apple, Intel and Hewlett‐Packard traded on the Nasdaq financial market.The Canadian Journal of Statistics40: 447–479; 2012 © 2012 Statistical Society of Canada
Synthesis and Antimicrobial Activities of Oximes Derived from O‐Benzylhydroxylamine as FabH Inhibitors
Authors: Luo Yin , Zhang Li‐Rong , Hu Yang , Zhang Shuai , Fu Jie , Wang Xiao‐Ming , Zhu Hai‐Liang
Published: July 2012

Forty‐three oxime derivatives were synthesized by allowing O‐benzylhydroxylamines to react with primary benzaldehydes or salicylaldehydes; these products were gauged as potential inhibitors of β‐ketoacyl‐(acyl‐carrier‐protein) synthase III (FabH). Among the 43 compounds, 38 are reported herein for the first time. These compounds were assayed for antimicrobial activities against Escherichia coli, Pseudomonas aeruginosa, Pseudomonas fluorescens, Bacillus subtilis, Staphylococcus aureus, and Enterococcus faecalis. Compounds with prominent antibacterial activities were tested for their E. coli FabH inhibitory activities. 3‐((2,4‐Dichlorobenzyloxyimino)methyl)benzaldehyde O‐2,4‐dichlorobenzyl oxime (44) showed the best antibacterial activity, with minimum inhibitory concentrations of 3.13–6.25 μg mL−1 against the tested bacterial strains, exhibiting the best E. coli FabH inhibitory activity, with an IC50 value of 1.7 mM. Docking simulations were performed to position compound 44 into the E. coli FabH active site in order to determine the most probable binding conformation.
Cellular components of the human medial amygdaloid nucleus
Authors: Dall'Oglio Aline , Xavier Léder L. , Hilbig Arlete , Ferme Denise , Moreira Jorge E. , Achaval Matilde , Rasia‐Filho Alberto A.
Published: July 2012

The medial nucleus (Me) is a superficial component of the amygdaloid complex. Here we assessed the density and morphology of the neurons and glial cells, the glial fibrillary acidic protein (GFAP) immunoreactivity, and the ultrastructure of the synaptic sites in the human Me. The optical fractionator method was applied. The Me presented an estimated mean neuronal density of 1.53 × 105neurons/mm3(greater in the left hemisphere), more glia (72% of all cells) than neurons, and a nonneuronal:neuronal ratio of 2.7. Golgi‐impregnated neurons had round or ovoid, fusiform, angular, and polygonal cell bodies (10–30 μm in diameter). The length of the dendrites varied, and pleomorphic spines were found in sparsely spiny or densely spiny cells (1.5–5.2 spines/dendritic μm). The axons in the Me neuropil were fine or coarsely beaded, and fibers showed simple or notably complex collateral terminations. The protoplasmic astrocytes were either isolated or formed small clusters and showed GFAP‐immunoreactive cell bodies and multiple branches. Furthermore, we identified both asymmetrical (with various small, clear, round, electron‐lucent vesicles and, occasionally, large, dense‐core vesicles) and symmetrical (with small, flattened vesicles) axodendritic contacts, also including multisynaptic spines. The astrocytes surround and may compose tripartite or tetrapartite synapses, the latter including the extracellular matrix between the pre‐ and the postsynaptic elements. Interestingly, the terminal axons exhibited a glomerular‐like structure with various asymmetrical contacts. These new morphological data on the cellular population and synaptic complexity of the human Me can contribute to our knowledge of its role in health and pathological conditions. J. Comp. Neurol. 521:589–611, 2013. © 2012 Wiley Periodicals, Inc.