Novel Route (novel + route)

Distribution by Scientific Domains

Selected Abstracts

A Novel Route to Thermosensitive Polymeric Core,Shell Aggregates and Hollow Spheres in Aqueous Media,

Y. Zhang
Abstract Poly(,-caprolactone)/poly(N -isopropylacrylamide) (PCL/PNIPAM) core,shell particles are obtained by localizing the polymerization of NIPAM and crosslinker methylene bisacrylamide around the surface of PCL nanoparticles. The resultant particles are converted to hollow PNIPAM spheres by simply degrading the PCL core with an enzyme. The hollow spheres are thermosensitive and display a reversible swelling and de-swelling at ,,32,C. [source]

A Novel Route to Multiphase Polymer Systems Containing Nano-Droplets: Radical Polymerization of Vinylic Monomers in Gelled Water-in-Oil Miniemulsions

Christian Holtze
Abstract Summary: A new strategy for the synthesis of composite polymers with larger volume fraction of aqueous inclusions less than 1 m in diameter is presented. A water-in-oil miniemulsion of aqueous droplets in a continuous, cross-linkable monomer phase is prepared. The addition of an organo-gelator allows the immobilization of the droplets in a solid gel, thus avoiding the usual demixing upon polymerization of the continuous phase. This pregelled system is then converted into a composite polymer by photoinitiated free radical polymerization. Such coatings may be used for an improved climate control of buildings or as a deposit for the controlled release of actives from polar nano-droplets. SEM image of a cross-linked composite polymer showing controlled droplet inclusions with a maximal diameter of 500 nm. [source]

A Novel Route for Fabricating Metal-Polymer Composite Nanoparticles with Phase-Separated Structures

Hiroshi Yabu
Abstract Au nanoparticles (NPs) and polymer composite particles with phase-separation structures were prepared based on phase separation structures. Au NPs were successfully synthesized in amphiphilic block-copolymer micelles, and then composite particles were formed by a simple solvent evaporation process from Au NPs and polymer solution. The phase separated structures (Janus and Core-shell) were controlled by changing the combination of polymers having differing hydrophobicity. [source]

A Novel Route to Organic,Inorganic Hybrid Nanomaterials

Bindushree Radhakrishnan
Abstract The in situ formation of functionalized silica nanoparticles is reported. The reactive stabilizers used in the study, [3-(2-bromoisobutyryl)propyl]triethoxysilane and [3-(2-bromoisobutyryl)propyl]ethoxydimethylsilane, have an atom transfer radical polymerization (ATRP) initiator at the noncondensable end. Condensation with tetraethoxysilane yields silica nanoparticles with a surface-immobilized initiator. The size of these functionalized silica nanoparticles can be controlled by varying the time of initiator addition and initiator concentration. The silica particle sizes ranged from 10 to 300 nm. With the initiator functionalized silica nanoparticles, ATRP synthesis was performed with styrene, tert -butyl acrylate, and methyl acrylate to produce organic,inorganic nanomaterials. [source]

Dynamic Chemical Instabilities in Living Cells May Provide a Novel Route in Drug Development

CHEMBIOCHEM, Issue 10 2004
Howard R. Petty Dr.
Chemical waves, such as the NAD(P)H (green) and Ca2+(white-orange) waves of neutrophils, are emergent properties of living cells that represent the collective behavior of proteins that constitute intracellular subsystems. Studies of these waves suggest novel approaches in drug development and fresh insights into several clinical issues. [source]

ChemInform Abstract: Transition Metal Catalyzed Cross-Coupling of 1,4-Diiodobutadienes with Thiols , A Novel Route to 1,4-Bis(sulfanyl)buta-1,3-dienes.

CHEMINFORM, Issue 52 2008
I. G. Trostyanskaya
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

ChemInform Abstract: A Simple and Novel Route for the Preparation of Chiral Sodium Zincophosphate.

CHEMINFORM, Issue 17 2008
Sen Liao
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Asymmetric Alkylation of N-Acylisoindolin-1-ones via ,-Bromoimides: A Novel Route to 1-Substituted Isoindolines.

CHEMINFORM, Issue 40 2007
Andreas Mueller
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

Ruthenium-Catalyzed Cycloisomerization,6,-Cyclization: A Novel Route to Pyridines.

CHEMINFORM, Issue 35 2007
Barry M. Trost
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

Novel Route to Azobenzenes via Pd-Catalyzed Coupling Reactions of Aryl Hydrazides with Aryl Halides, Followed by Direct Oxidations.

CHEMINFORM, Issue 31 2003
Young-Kwan Lim
No abstract is available for this article. [source]

Methyl 3,3-Difluoro-2-trimethylsilyoxyacrylate: Preparation and Mukaiyama-Type Aldol Condensation as a Novel Route to ,,,-Difluoro-,-keto Ester Derivatives.

CHEMINFORM, Issue 48 2002
Biao Jiang
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

ChemInform Abstract: A Novel Route for Synthesis of ,-Butyrolactone Through the Coupling of Hydrogenation and Dehydrogenation.

CHEMINFORM, Issue 20 2002
Yu-Lei Zhu
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

ChemInform Abstract: Studies on Intramolecular Alkylation of an ,-Sulfinyl Vinylic Carbanion: A Novel Route to Chiral 1-Cycloalkenyl Sulfoxides.

CHEMINFORM, Issue 5 2001
Naoyoshi Maezaki
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Novel Routes for the Generation of Structurally Diverse Labdane Diterpenes from Andrographolide.

CHEMINFORM, Issue 40 2004
Srinivas Nanduri
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

Novel Routes to Chiral 2-Alkoxy-5-/6-methoxycarbonylmethylidenepyrrolidines/-piperidines.

CHEMINFORM, Issue 33 2004
Olivier David
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

Ring-Closing Metathesis: Novel Routes to Aromatic Heterocycles

Abstract Olefin metathesis has been established as an important and general reaction in synthetic organic chemistry. Recently, it has attracted interest as a powerful tool for the construction of aromatic heterocycles. The importance of heteroaromatic motifs in medicinal chemistry and biology, as well as the efficiency and wealth of metathesis transformations, have resulted in significant success in this rapidly developing area. [source]

Novel routes to aminophosphonic acids: Interaction of dimethyl H-phosphonate with hydroxyalkyl carbamates

K. Troev
It was found that the reaction of dimethyl H-phosphonate (1) with 2-hydroxyalkyl- N -2,-hydroxyalkyl carbamates at 135C includes several chemical reaction steps: (i) chemical transformations of 1-methyl-2-hydroxyethyl- N -2,-hydroxyethyl carbamate (2) and 2-methyl-2-hydroxyethyl- N -2,-hydroxyethyl carbamate (3); (ii) transesterification of dimethyl H -phosphonate with 2 and 3, and with secondary hydroxyl-containing compounds that are formed during the course of the chemical transformation of 2-hydroxyalkyl- N -2,-hydroxyalkyl carbamates; (iii) hydrolysis of 1 and dialkyl H-phosphonates, formed via transesterification of 1 with secondary hydroxyl-containing compounds. The interaction was studied by means of 1H, 13C, 31P NMR, and FAB mass spectroscopy. 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:119,124, 2008; Published online in Wiley InterScience ( DOI 10.1002/hc.20404 [source]

Generation of a Hydroperoxidochromium Complex from Nitratochromium(III) Ions and Hydrogen Peroxide

Mingming Cheng
Abstract Accelerated substitution at chromium(III) in CraqONO22+ provides the basis for a novel route to the corresponding hydroperoxidochromium complex in aqueous solutions. Despite the great concentration advantage of water, the reaction of CraqONO22+ with 10,100 mM H2O2 generates >50,% yields of CraqOOH2+, which makes this reaction useful for preparative purposes, and may also represent a potential source of high-valent chromium in biological environments. In a minor, parallel path, small concentrations of a superoxidochromium(III) complex, CraqOO2+, are also produced. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

Autophagy and adaptive immunity

IMMUNOLOGY, Issue 1 2010
Victoria L. Crotzer
Summary Autophagy plays an important role in maintaining intracellular homeostasis by promoting the transit of cytoplasmic material, such as proteins, organelles and pathogens, for degradation within acidic organelles. Yet, in immune cells, autophagy pathways serve an additional role in facilitating intracellular surveillance for pathogens and changes in self. Autophagy pathways can modulate key steps in the development of innate and adaptive immunity. In terms of adaptive immunity, autophagy regulates the development and survival of lymphocytes as well as the modulation of antigen processing and presentation. Specialized forms of autophagy may be induced by some viral pathogens, providing a novel route for major histocompatibility complex (MHC) class I antigen presentation and enhanced CD8+ T-cell responses. Autophagy induction in target cells also increases their potential to serve as immunogens for dendritic cell cross-presentation to CD8+ T cells. The requirement for autophagy in MHC class II presentation of cytoplasmic and nuclear antigens is well established, yet recent studies also point to a critical role for autophagy in modulating CD4+ T-cell responses to phagocytosed pathogens. Autophagy pathways can also modulate the selection and survival of some CD4+ T cells in the thymus. However, much still remains to be learned mechanistically with respect to how autophagy and autophagy-linked genes regulate pathogen recognition and antigen presentation, as well as the development and survival of immune cells. [source]

One Nanometer Thin Carbon Nanosheets with Tunable Conductivity and Stiffness

Andrey Turchanin
Atomically thin (,1,nm) carbon films and membranes whose electrical behavior can be tuned from insulating to conducting are fabricated by a novel route. These films present arbitrary size and shape based on molecular self-assembly, electron irradiation, and pyrolysis, and their technical applicability is demonstrated by their incorporation into a microscopic pressure sensor. [source]

Preparation of Machinable Fluoramphibole Glass,Ceramics from Soda-Lime Glass and Fluormica

Weiyi Zhang
A novel route, directly mixing fluormica crystals with recycled soda-lime glass powder and then sintering, is proposed to fabricate machinable fluoramphibole glass,ceramics. The effect of fluormica addition on the sinterability, reactive crystallization behavior, strength, and machinability of the material was investigated. The relative densities of the glass,ceramics decreased with increasing fluormica content. An interaction between fluormica crystals and glass powder occurred during the sintering process. Diopside was formed in the glass,ceramics with 20 wt% fluormica, and fluorrichterite was formed in the glass,ceramics with more than 30 wt% fluormica. Machinability and strength of the glass,ceramics were improved with increasing crystalline phase content. [source]

A novel route for preparation of PVC sheets with high UV irradiation resistance

Xianke Ye
Abstract A novel acrylonitrile acrylate copolymer coating was proposed to improve the UV irradiation resistance of poly(vinyl chloride) (PVC) sheets. Its effect on the photoageing properties of the sheets was evaluated by means of Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), yellowness index test, and the oxygen permeability coefficient and mechanical properties measurement. The experimental results show that the novel acrylonitrile acrylate copolymer coating significantly improves the UV irradiation resistance of PVC sheets. Compared with the PVC sheets without coating, the coated PVC sheets show better mechanical properties, lower yellowness index, and smaller oxygen permeability coefficient after UV irradiation. The analysis on the SEM images of the PVC sheets indicates that the coating acts as a film to prevent the PVC sheets from UV energy and oxygen that can accelerate the photochemical reactions of PVC. The FTIR analysis confirms that the coating can slow down the microstructures development of the PVC sheets, also indicating that the coating impeded the photochemical reactions of PVC. 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

Solvent/non-solvent sintering: A novel route to create porous microsphere scaffolds for tissue regeneration

Justin L. Brown
Abstract Solvent/non-solvent sintering creates porous polymeric microsphere scaffolds suitable for tissue engineering purposes with control over the resulting porosity, average pore diameter, and mechanical properties. Five different biodegradable biocompatible polyphosphazenes exhibiting glass transition temperatures from ,8 to 41C and poly (lactide- co -glycolide), (PLAGA) a degradable polymer used in a number of biomedical settings, were examined to study the versatility of the process and benchmark the process to heat sintering. Parameters such as: solvent/non-solvent sintering solution composition and submersion time effect the sintering process. PLAGA microsphere scaffolds fabricated with solvent/non-solvent sintering exhibited an interconnected porosity and pore size of 31.9% and 179.1 ,m, respectively which was analogous to that of conventional heat sintered PLAGA microsphere scaffolds. Biodegradable polyphosphazene microsphere scaffolds exhibited a maximum interconnected porosity of 37.6% and a maximum compressive modulus of 94.3 MPa. Solvent/non-solvent sintering is an effective strategy for sintering polymeric microspheres, with a broad spectrum of glass transition temperatures, under ambient conditions making it an excellent fabrication route for developing tissue engineering scaffolds and drug delivery vehicles. 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source]

,2 -Isoxazolines from ,,,-unsaturated oximes

Michael D. Mosher
3,5-Disubstituted ,2 -isoxazolines can be prepared using the palladium-mediated nucleometalation / methoxycarbonylation of ,,,-unsaturated oximes. This novel route to this class of compounds is tolerant of a wide variety of functionality in the starting material, and provides a rapid route to highly functionalized isoxazolines. [source]

A novel route to the 5,6-dihydro-4-H-thieno[3,2-b]pyrrol-5-one ring system involving an intermediate substituted-thiophene synthesis

Shuanghua Hu
A novel route to electron-deficient thienopyrrolones is disclosed. The target heterocycles are concisely constructed by condensation of activated ,- or ,-halo-substituted acrylonitriles, or ortho -substituted halo, cyano heterocycles with mercaptopyruvate, followed by reduction and subsequent lactamization. [source]

Titanium-mediated [CpTiCl2(OEt)] ring-opening polymerization of lactides: A novel route to well-defined polylactide-based complex macromolecular architectures

Nikolaos Petzetakis
Abstract Among three cyclopentadienyl titanium complexes studied, CpTiCl2(OEt), containing a 5% excess CpTiCl3, has proven to be a very efficient catalyst for the ring-opening polymerization (ROP) of L -lactide (LLA) in toluene at 130 C. Kinetic studies revealed that the polymerization yield (up to 100%) and the molecular weight increase linearly with time, leading to well-defined PLLA with narrow molecular weight distributions (Mw/Mn , 1.1). Based on the above results, PS- b -PLLA, PI- b -PLLA, PEO- b -PLLA block copolymers, and a PS- b -PI- b -PLLA triblock terpolymer were synthesized. The synthetic strategy involved: (a) the preparation of OH-end-functionalized homopolymers or diblock copolymers by anionic polymerization, (b) the reaction of the OH-functionalized polymers with CpTiCl3 to give the corresponding Ti-macrocatalyst, and (c) the ROP of LLA to afford the final block copolymers. PMMA- g -PLLA [PMMA: poly(methyl methacrylate)] was also synthesized by: (a) the reaction of CpTiCl3 with 2-hydroxy ethyl methacrylate, HEMA, to give the Ti-HEMA-catalyst, (b) the ROP of LLA to afford a PLLA methacrylic-macromonomer, and (c) the copolymerization (conventional and ATRP) of the macromonomer with MMA to afford the final graft copolymer. Intermediate and final products were characterized by NMR spectroscopy and size exclusion chromatography, equipped with refractive index and two-angle laser light scattering detectors. 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1092,1103, 2010 [source]

A novel route to poly(,-hydroxyacrylic acid) derivatives by the hydrolysis of polymers containing 1,3-dioxolan-4-one moiety

Toyoharu Miyagawa
Abstract The alkali hydrolysis of poly(2,2-dimethyl-5-methylene-1,3-dioxolan-4-one) and poly(2,2-dimethyl-5-methylene-1,3-dioxolan-4-one- co -styrene) was carried out with a sodium hydroxide solution (40%) in tetrahydrofuran at room temperature to obtain poly(,-hydroxyacrylic acid) or poly(,-hydroxyacrylic acid- co -styrene) with number-average molecular weights of 39,000,73,000 in 41,86% yields. The styrene unit in the hydrolyzed copolymer hindered the formation of a lactone ring. 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1629,1633, 2001 [source]

Organometallic Complexes for Nonlinear Optics, 47 , Synthesis and Cubic Optical Nonlinearity of a Stilbenylethynylruthenium Dendrimer,

Christopher J. Jeffery
Abstract The synthesis of the 1st generation dendrimer 1,3,5-{trans -[Ru(C,C-3,5-(trans -[Ru(C,CPh)(dppe)2(C,CC6H4 -4-(E)-CHCH)])2C6H3)(dppe)2(C,CC6H4 -4-(E)-CHCH)]}3C6H3 proceeds by a novel route that features Emmons-Horner-Wadsworth coupling of 1,3,5-C6H3(CH2PO(OEt)2)3 with trans -[Ru(C,CC6H4 -4-CHO)Cl(dppe)2] and 1-I-C6H3 -3,5-(CH2PO(OEt)2)2 with trans -[Ru(C,CPh)(C,CC6H4 -4-CHO)(dppe)2] as key steps. The stilbenylethynylruthenium dendrimer is much more soluble than its ethynylated analog 1,3,5-{trans -[Ru(C,C-3,5-(trans -[Ru(C,CPh)(dppe)2(C,CC6H4 -4-C,C)])2C6H3)(dppe)2(C,CC6H4 -4-C,C)]}3C6H3 and, in contrast to the ethynylated analog, is a two-photon absorber at telecommunications wavelengths. [source]

Characteristics of polyimide ultrafine fibers prepared through electrospinning

Changwoon Nah
Abstract A novel route for making polyimide sub-micron fibers is described. The ultrafine fibers are prepared by electrospinning a poly(amic acid) solution, a precursor of polyimide, followed by thermal imidization. The fiber diameters, which are much smaller than conventionally spun fibers, range from a few tens of nanometers to several micrometers. A rectangular cross-section is observed in the case of sub-micron fibers with a cross-sectional dimension below ,500,nm. 2003 Society of Chemical Industry [source]

Structure of reactively extruded rigid PVC/PMMA blends

Y. Haba
Abstract A novel route for producing polymer blends by reactive extrusion is described, starting from poly (vinyl chloride)/methyl methacrylate (PVC/MMA) dry blend and successive polymerization of MMA in an extruder. Small angle X-ray scattering (SAXS) measurements were applied to study the monomer's mode of penetration into the PVC particles and to characterize the supermolecular structure of the reactive poly(vinyl chloride)/poly(methyl methacrylate) (PVC/PMMA) blends obtained, as compared to the corresponding physical blends of similar composition. These measurements indicate that the monomer molecules can easily penetrate into the PVC sub-primary particles, separating the PVC chains. Moreover, the increased mobility of the PVC chains enables formation of an ordered lamellar structure, with an average d -spacing of 4.1,nm. The same characteristic lamellar structure is further detected upon compression molding or extrusion of PVC and PVC/PMMA blends. In this case the mobility of the PVC chains is enabled through thermal energy. Dynamic mechanical thermal analysis (DMTA) and SAXS measurements of reactive and physical PVC/PMMA blends indicate that miscibility occurs between the PVC and PMMA chains. The studied reactive PVC/PMMA blends are found to be miscible, while the physical PVC/PMMA blends are only partially miscible. It can be suggested that the miscible PMMA chains weaken dipole,dipole interactions between the PVC chains, leading to high mobility and resulting in an increased PVC crystallinity degree and decreased PVC glass transition temperature (Tg). These phenomena are shown in the physical PVC/PMMA blends and further emphasized in the reactive PVC/PMMA blends. Copyright 2005 John Wiley & Sons, Ltd. [source]