bluuebunny/crossref_metadata_2025_split huggingface dataset:
Short noncoding DNA fragment improve efficiencies of in vivo electroporation‐mediated gene transfer
Authors: Peng Jinliang , Zhao Yonggang , Mai Junhua , Guo Wei , Xu Yuhong 
Published: August 2012

AbstractBackgroundA major obstacle to the application of gene therapy methods in experimental and clinical practice is the lack of safe and efficient gene delivery systems. Electroporation has been shown to an effective physical delivery method. A variety of factors have been shown to affect the electroporation‐mediated gene delivery efficiency. In the present study, we assessed the usefulness of noncoding short‐fragment DNA (sf‐DNA) for facilitating electroporation‐mediated gene transfer.MethodsThe plasmid pGL3‐control encoding firefly luciferase was injected into tissues together with or without sf‐DNA. Immediately after injection, the tissues were electroporated and the level of luciferase activity was assessed 24 h later. Different types of DNA fragments with different molecular weights, structures and doses were compared. The transfection efficiencies of sf‐DNA‐mediated electroporation in different tissues or with different electric field strengths were examined.ResultsPlasmid DNA formulated with 300‐bp sf‐DNA resulted in a significant improvement in electroporation‐mediated gene transfer efficiency. The effect is dose‐dependent and is also affected by DNA fragment length and structure. It was useful for intramuscular electroporation application, as well as intratumoral application with various pulse voltage parameters.ConclusionsThe data obtained in the present study indicate that sf‐DNA can be used as a helper molecule to improve electroporation‐mediated gene transfection efficiency. Copyright © 2012 John Wiley & Sons, Ltd.
The male copulatory system of european pea crabs (crustacea, brachyura, pinnotheridae)
Authors: Becker Carola , Türkay Michael , Brandis Dirk 
Published: August 2012

AbstractThe male copulatory system of the European pinnotherid species Pinnotheres pisum, Pinnotheres pectunculi, and Nepinnotheres pinnotheres was investigated by gross morphology, scanning electron microscopy, histological methods, and confocal laser scanning microscopy. The brachyuran copulatory system is consistently formed by paired penes and two pairs of abdominal appendages, the gonopods, functioning in sperm transfer. In pinnotherids, the long first gonopods transfer the sperm mass into the female ducts. The first gonopod has the ejaculatory canal inside that opens both basally and distally. The second gonopod is solid, short, and conical. During copulation, the penis and the second gonopod are inserted into the basal lumen of the first gonopod. While the penis injects the sperm mass, the second gonopod functions in the transport of spermatozoa inside the ejaculatory canal toward its distal opening. The second gonopod is adapted for the sealing of the tubular system in the first gonopod by its specific shape and the ability to swell. Longitudinal cuticle foldings of the second gonopod hook into structures inside the first gonopod. The second gonopod can interact with the penis during copulation by a flexible flap separating the lumina in which the second gonopod and the penis are inserted. J. Morphol., 2012. © 2012 Wiley Periodicals, Inc.
Dose–response effect of an intra‐tendon application of recombinant human platelet‐derived growth factor‐BB (rhPDGF‐BB) in a rat Achilles tendinopathy model
Authors: Shah Vivek , Bendele Alison , Dines Joshua S. , Kestler Hans K. , Hollinger Jeffrey O. , Chahine Nadeen O. , Hee Christopher K. 
Published: August 2012

AbstractThe purpose of this study was to assess whether intra‐tendon delivery of recombinant human platelet‐derived growth factor‐BB (rhPDGF‐BB) would improve Achilles tendon repair in a rat collagenase‐induced tendinopathy model. Seven days following collagenase induction of tendinopathy, one of four intra‐tendinous treatments was administered: (i) Vehicle control (sodium acetate buffer), (ii) 1.02 µg rhPDGF‐BB, (iii) 10.2 µg rhPDGF‐BB, or (iv) 102 µg rhPDGF‐BB. Treated tendons were assessed for histopathological (e.g., proliferation, tendon thickness, collagen fiber density/orientation) and biomechanical (e.g., maximum load‐to‐failure and stiffness) outcomes. By 7 days post‐treatment, there was a significant increase in cell proliferation with the 10.2 and 102 µg rhPDGF‐BB‐treated groups (p = 0.049 and 0.015, respectively) and in thickness at the tendon midsubstance in the 10.2 µg of rhPDGF‐BB group (p = 0.005), compared to controls. All groups had equivalent outcomes by Day 21. There was a dose‐dependent effect on the maximum load‐to‐failure, with no significant difference in the 1.02 and 102 µg rhPDGF‐BB doses but the 10.2 µg rhPDGF‐BB group had a significant increase in load‐to‐failure at 7 (p = 0.003) and 21 days (p = 0.019) compared to controls. The rhPDGF‐BB treatment resulted in a dose‐dependent, transient increase in cell proliferation and sustained improvement in biomechanical properties in a rat Achilles tendinopathy model, demonstrating the potential of rhPDGF‐BB treatment in a tendinopathy application. Consequently, in this model, data suggest that rhPDGF‐BB treatment is an effective therapy and thus, may be an option for clinical applications to treat tendinopathy. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 413–420, 2013
Iceberg‐type problems: Estimating Hidden parts of a continuum from the visible parts
Authors: Barnard Roger W. , Pearce Kent , Solynin Alexander Yu. 
Published: August 2012

AbstractWe consider the complex plane \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\mathbb {C}$\end{document} as a space filled by two different media, separated by the real axis \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\mathbb {R}$\end{document}. We define \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\mathbb {H}_+=\lbrace z: \,\Im \,z>0\rbrace$\end{document} to be the upper half‐plane. For a planar body E in \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\mathbb {C}$\end{document}, we discuss a problem of estimating characteristics of the “invisible” part, \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$E_-=E\setminus \mathbb {H}_+$\end{document}, from characteristics of the whole body E and its “visible” part, \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$E_+=E\cap \mathbb {H}_+$\end{document}. In this paper, we find the maximal draft of E as a function of the logarithmic capacity of E and the area of E+.
Metabolism and permeability of curcumin in cultured Caco‐2 cells
Authors: Dempe Julia S. , Scheerle Romy K. , Pfeiffer Erika , Metzler Manfred 
Published: August 2012

ScopeCurcumin (CUR) and its major metabolite hexahydro‐CUR were studied in Caco‐2 cells and in the Caco‐2 Millicell® system in vitro to simulate their in vivo intestinal metabolism and absorption in humans.Methods and resultsAnalysis of the incubation medium and cell lysate showed that Caco‐2 cells reduce CUR to hexahydro‐CUR and octahydro‐CUR, and conjugate CUR and its reductive metabolites with glucuronic acid and sulfate. Using the Caco‐2 Millicell® system, an efficient transfer of the conjugates into the basolateral, but not the apical, compartment was observed after apical administration. Likewise, hexahydro‐CUR was reduced to octahydro‐CUR, and glucuronide and sulfate conjugates almost exclusively permeated to the basolateral side. The apparent permeability coefficients (Papp values) of CUR, hexahydro‐CUR and their metabolites were determined and found to be extremely low for unchanged CUR, but somewhat higher for hexahydro‐CUR and the conjugated metabolites.ConclusionThe results of this study clearly show that the systemic bioavailability of CUR from the intestine after oral intake must be expected to be virtually zero. Reductive and conjugated metabolites, formed from CUR in the intestine, exhibit moderate absorption. Thus, any biological effects elicited by CUR in tissues other than the gastrointestinal tract are likely due to CUR metabolites.
Curcumin attenuates testicular damage, apoptotic germ cell death, and oxidative stress in streptozotocin‐induced diabetic rats
Authors: Kanter Mehmet , Aktas Cevat , Erboga Mustafa 
Published: August 2012

ScopeThe present study was designed to examine the protective and antioxidative effects of curcumin (Cur) on streptozotocin (STZ) induced testicular damage, apoptotic germ cell death, and oxidative stress.Methods and resultsDiabetes was induced by a single intraperitoneal injection of STZ (50 mg/kg). The rats in the Cur‐treated group were given Cur (100 mg/kg) once a day intragastrik for 8 weeks starting 3 days prior to STZ injection. Cur treatment significantly decreased the elevated tissue malondialdehyde levels and increased the reduced superoxide dismutase, and glutathione peroxidase enzyme activities in testis tissues samples. The Cur‐treated rats in the diabetic group showed an improved histological appearance and serum testosterone levels. Our data indicate a significant reduction in the activity of in situ identification of apoptosis using terminal dUTP nick end‐labeling and there was a rise in the expression of proliferating cell nuclear antigen in testis tissues of Cur‐treated rats in the diabetic group.ConclusionThese results demonstrate that Cur attenuated testicular damage in diabetic rats by decreasing oxidative stress.
Structural analyses of mannose pentasaccharide of high mannose type oligosaccharides by 1D and 2D NMR spectroscopy
Authors: Kubota Yumiko , Hori Hiroshi , Sawa Ryuichi , Seki Hiroko , Uzawa Jun 
Published: August 2012

NMR spectroscopy is a very important and useful method for the structural analysis of oligosaccharides, despite its low sensitivity. We first applied conventional measuring methods, 2D DQF COSY, 1H–13C HSQC, and 1H–13C HMBC, and also the Double Pulsed Field Gradient Spin Echo (DPFGSE)‐TOCSY and DPFGSE‐NOESY/ROESY techniques to analyze a branched mannose pentasaccharide as a model of high mannose type N‐glycans in natural abundance. The NMR spectra of the model compound are very complex and difficult to analyze owing to overlapping signals. The superior selective irradiation capability of the DPFGSE technique is useful for fine structural and conformational analyses of such complex oligosaccharides.We here introduce a novel technique called DPFGSE‐Double‐Selective Population Transfer (SPT)‐Difference and DPFGSE‐NOE/ROE‐SPT‐Difference spectroscopy. The DPFGSE‐Double‐SPT‐Difference method involves irradiation of two peaks from one proton and the subtraction of higher and lower peaks from each spectrum. The DPFGSE‐NOE/ROE‐SPT‐Difference method involves the transfer of the magnetization polarized by NOE/ROE from the nuclei to the spin‐coupled nuclei through scalar spin–spin interaction using the SPT method. Even if the signals in the NMR spectra overlap, each signal can be accurately assigned. In particular, DPFGSE‐NOE/ROE‐SPT‐Difference is very useful for identifying sugar connectivity. Copyright © 2012 John Wiley & Sons, Ltd.
Qualitative and Semi‐quantitative Analysis of Phenolics in Eucalyptus globulus Leaves by High‐performance Liquid Chromatography Coupled with Diode Array Detection and Electrospray Ionisation Mass Spectrometry
Authors: Boulekbache‐Makhlouf Lila , Meudec Emmanuelle , Mazauric Jean‐Paul , Madani Khodir , Cheynier Véronique 
Published: August 2012

ABSTRACTIntroductionEucalyptus species are widely cultivated in Mediterranean regions. Moreover, plants of this family have been utilized for medicinal purposes. A number of studies have been devoted to the identification of eucalypt phenolics, all of them have focused on specific families of compounds, and no exhaustive profiling has been reported in leaves of this plant.ObjectiveTo develop methods that allows the identification and quantification of different classes of phenolics in Eucalyptus globulus leaf.MethodologyAcetonic extract was fractionated by chromatography on a Sephadex LH‐20 column using consecutive elution with ethanol, methanol and aqueous acetone (60%). High‐performance liquid chromatography coupled with diode array detection and electrospray ionization mass spectrometry (HPLC‐DAD‐ESI/MS) were applied to determine the structure of different compounds. Quantities were evaluated from peak areas in the HPLC profile, using external calibration curves.ResultsFractionation of acetonic extract yielded three fractions: F1, F2 and F3. In total 39 phenolic compounds are detected. Among them: 16 hydrolyzable tannins, 3 terpenyl derivatives, 12 ellagic acid derivatives, 5 flavonols, 2 hydroxybenzoic acids and 1 formylated phloroglucinol. 26 compounds described in this study have not previously detected in leaves of this plant and this is the first report of quercetin 3‐O‐β‐galactoside‐6”‐O‐gallate and cypellogin A and B, in E. globulus plant. Quantitatively, ellagic acid derivatives and sideroxylonal A or B are largely predominant.ConclusionFractionation of crude extract by chromatography on Sephadex LH‐20 was efficient to separate different molecular weight compounds. HPLC‐DAD‐ESI/MS enabled detection of gallotannin, ellagitannin and flavonol derivatives, in leaves of E. globulus. Copyright © 2012 John Wiley & Sons, Ltd.
The effect of molecular weight and catalyst concentration on catalytic activity in mechanochemically activated transesterification using silver(I)‐N‐heterocyclic carbene latent catalysts
Authors: Groote Ramon , van Haandel Lennart , Sijbesma Rint P. 
Published: August 2012

AbstractWe have investigated the effect of the concentration and molecular weight on the activity of polymeric silver(I)‐NHC (NHC = N‐heterocyclic carbene) catalyst complexes in ultrasound‐induced mechanochemical catalyst activation. A strong dependence of the turnover number (TON) on initial catalyst concentration was observed in the transesterification of vinyl acetate with benzyl alcohol. The main findings of this study are that the concentration and molecular weight effects on TON are caused by competition between mechanochemical catalyst activation and deactivation, most likely by reactive species produced during the sonication process. Performing the transesterification reaction under radical‐suppressing conditions resulted in a significant increase of TON. This result clearly demonstrates the increased catalyst lifetime when reducing the amount of sonochemical impurities, and it highlights the importance of controlling and suppressing secondary, sonochemical processes when using ultrasound‐induced mechanochemical generation of reactive species such as catalysts. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Synthesis of well‐defined chitosan‐based tricomponent copolymers for constructing multifunctional delivery systems
Authors: Yu Lin , Cao Moyuan , Zhang Haiwen , Xiong Han , Jin Yucun , Lu Yi , Jia Haiyan , Luo Dongsheng , Wang Liqun , Jiang Hongliang 
Published: August 2012

AbstractChitosan‐based tricomponent copolymers, chitosan‐g‐poly(ε‐caprolactone)‐(g‐poly(oligo(ethylene glycol) methacrylate)) (CS‐PCL‐POEGMA, CPP), are synthesized as multifunctional nanocarriers for antitumor therapy. 2‐Bromoisobutyric acid and PCL are first site‐specifically conjugated onto the hydroxy groups of chitosan backbone through conventional coupling chemistry to give CS‐PCL‐Br using sodium dodecyl sulfate–chitosan complex as an organosoluble intermediate. CPP‐PCL‐Br is further used for initiating the single electron transfer‐living radical polymerization of OEGMA in the mixed solvent of dimethyl sulfoxide and lactic acid, yielding CPP. One‐pot reaction of CPP with a small amount of NaN3 under the catalysis of Cu(I)Br/tris‐(2‐dimethylaminoethyl)amine converts the bromo ends of POEGMA grafts to azide functionality, which is used for conjugation of folic acid targeting moiety via azide–alkyne click reactions. The resultant tricomponent copolymers can assemble into spherical micelles with the capacity of coincorporating indocyanine green and Doxorubicin through electrostatic and hydrophobic interactions, respectively. The dual‐agent‐loaded micelles display a combined effect for combating HepG2 cells when irradiated with near‐infrared laser. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
A novel benzimidazole‐containing phthalonitrile monomer with unique polymerization behavior
Authors: Wu Dimeng , Zhao Yongchao , Zeng Ke , Yang Gang 
Published: August 2012

AbstractA novel benzimidazole‐containing phthalonitrile monomer (BIPN) was synthesized. The chemical structure of BIPN was confirmed by various spectroscopic techniques. Differential scanning calorimetry measurement revealed that the self‐promoted polymerization reaction of the BIPN proceeds extremely sluggish and showed low polymerization exothermic effect. Subsequent rheological measurement displayed that the BIPN was able to keep a stable and low melt viscosity for 4 h at 300 °C, 2 h at 310 °C, and 50 min at 330 °C. The derived BIPN polymers showed excellent thermal properties revealed by thermogravimetric analysis, which were better than those of the corresponding polymer derived from phthalonitrile monomer without benzimidazole moiety. IR analysis confirmed the occurrence of the triazine ring within the polymer crosslinking sites. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Effects of Varying Heptylamine and Propionaldehyde Plasma Polymerization Parameters on Mesenchymal Stem Cell Attachment
Authors: Sandstrom Anne M. , Jasieniak Marek , Griesser Hans J. , Grøndahl Lisbeth , Cooper‐White Justin J. 
Published: August 2012

AbstractThis paper investigated the impacts of two deposition times (30 s, 60 s) and discharge powers (20 W, 50 W) on the resultant chemical and physical properties of plasma polymers (pp) formed using heptylamine (HA) or propionaldehyde (PA) monomers. Pinhole‐free pp films were formed on all surfaces at deposition rates that varied according to both the time and power employed. XPS and ToF‐SIMS analysis showed that power has a more of an effect than time on the chemical properties of the pp, which may be attributed to differences in monomer fragmentation and cross‐linking. Mesenchymal stem cell (MSC) adhesion did not vary on the four different HApp surfaces, whereas a negative correlation between cell attachment and increasing plasma energy was observed on PApp surfaces. This suggests that the presence of oxygenated groups, particularly aldehyde and carboxylic groups, may have a dominant impact on MSC adhesion to these functional polymer substrates. magnified image
Electric‐field‐assisted crystallisation in phase‐change materials
Authors: Kohary Krisztian , Diosdado Jorge A. Vázquez , Ashwin Peter , Wright C. David 
Published: August 2012

AbstractPhase‐change materials are of intense research interest due mainly to their use in phase‐change memory (PCM) devices that are emerging as a promising technology for future non‐volatile, solid‐state, electrical storage. Electrically driven transitions from the amorphous to the crystalline phase in such devices exhibit characteristic threshold switching. Several alternative electronic explanations for the origins of this characteristic behaviour have been put forward, for example Poole–Frenkel effects, delocalisation of tail states, field emission processes and space charge limited currents [for a full discussion, see Radielli et al., J. Appl. Phys. 103, 111101 (2008) and Simon et al., MRS Proc. 1251, H01–H011 (2010)]. However, an alternative to these conventional electronic models of threshold switching is based on electric field induced lowering of the system free energy, leading to the field induced nucleation of conducting crystal filaments. In this paper we investigate this alternative view. We present a detailed kinetics study of crystallisation in the presence of an electric field for the phase‐change material Ge2Sb2Te5. We derive quantitative crystallisation maps to show the effects of both temperature and electric field on crystallisation and we identify field ranges and parameter values where the electric field might play a significant role. Then we carry out physically realistic simulations of the threshold switching process in typical phase‐change device structures, both with and without electric field dependent energy contributions to the system free energy. Our results show that threshold switching can be obtained by a mechanism driven purely by electric field induced nucleation, but the fields so required are large, of the order of 300 MV m−1, and significantly larger than the experimentally measured threshold fields.
Crystal structure and electronic properties of the new structure dinitride–nitride N2MN (M: Cu, Ag)
Authors: Zhuravlev Yuriy , Lisitsyn Viktor , Morozova Yelena 
Published: August 2012

AbstractCopper and nitrogen compounds and silver and nitrogen compounds have been researched with the first‐principle linear combination of the atomic orbitals in full‐screen basis with the local gradient and hybrid potential of the density functional theory (DFT) realized in the CRYSTAL09 program code. We have found the structural N2MN (M: Cu, Ag) dinitride–nitride phase having an orthorhombic structure, the spatial group of the Ibam symmetry and four formula units in the primitive cell that have not been reported before. The structure was found to be layered, the metal atoms are linearly circled by the nitride N atoms, whereas, the other two atoms make a molecule with a small negative charge of ∼0.02 e. The volume elastic modules in N2CuN, N2AgN crystals are equal to 4.3 and 6.6 GPa, respectively, and their pressure derivatives are equal to 6.7 and 5.3, respectively. The electron energy spectrum makes a superposition of weakly interacting molecular states of N2 and metal states of MN. The bandgap width equals ∼0.05 eV. The estimations of the enthalpy energies show that N2MN possess large energy content and in its decomposition into metal and gaseous nitride the energy release can reach 8 eV cell−1, which appears to be higher than that in the known metal azides. Thus, the new structure of the dinitride–nitride N2MN combines the properties of molecular and semiconductor crystals: high compressibility, strong mechanical anisotropy, localized vacant states in the zone spectrum, and small bandgap. The unique physical properties can ensure their application as energy materials, the source of chemically pure nitride, and in semiconductor and optical material science.
Towards a better understanding of intergranular phases in Fe–Nd–B sintered magnets
Authors: Goll Dagmar , Schweizer Stephanie , Wegierski Christian , Schneider Gerhard 
Published: August 2012

AbstractIntergranular phases in Fe–Nd–B sintered magnets, which crystallize out of an under‐sintering liquid phase, form a complex structure below 655 °C and influence the magnetic properties. In model experiments the microstructure has been coarsened to study the thermodynamics and kinetics of the intergranular regions in the as‐sintered and as‐annealed condition. It is found that after sintering eutectic solidification products are present in the grain boundaries which are transformed during annealing at moderate temperatures. Similar results are observed in as‐cast Nd‐rich model samples.magnified image(© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)