Short Contacts (short + contact)

Distribution by Scientific Domains

Terms modified by Short Contacts

  • short contact time

  • Selected Abstracts


    Treatment of Inflammatory Facial Acne Vulgaris with Intense Pulsed Light and Short Contact of Topical 5-Aminolevulinic Acid: A Pilot Study

    DERMATOLOGIC SURGERY, Issue 8 2006
    JINDA ROJANAMATIN MD
    BACKGROUND Photodynamic therapy (PDT) with topical 5-aminolevulinic acid (ALA) and red light (550,700 nm) has been introduced for effective treatment of facial acne. Untoward side effects are common, however. OBJECTIVE To evaluate the efficacy and safety of the short contact of topical ALA and intense pulsed light (IPL) in treatment of inflammatory facial acne. METHODS Fourteen patients with inflammatory facial acne were treated with IPL on the left side and combination of IPL and topical ALA on the right side at 3- to 4-week intervals for three sessions. Clinical photographs and lesion counts were obtained for evaluation. RESULTS All patients revealed a reduction in number of acne lesions on both sides. On the ALA-pretreated side, lesion counts decreased 87.7% at 12 weeks after the last treatment (p<.01). Meanwhile, lesion counts on the nonpretreated side decreased 66.8% (p<.01). In addition, a number of lesion counts on the ALA-pretreated side decreased. Mild edema and minimal crust developed on the combined-treatment side. CONCLUSION Short contact of topical ALA and IPL or IPL alone showed some beneficial effect in treatment of inflammatory facial acne; however, degree of improvement was better and remained longer with the combined regimen. Side effects were mild and reversible. [source]


    Transfer of Triazine-iron(II) Chromic Complexes Left by Iron Items on Textile Background and Human Skin

    JOURNAL OF FORENSIC SCIENCES, Issue 4 2010
    Jakub Szumera M.Sc.
    Abstract:, The research is focused on the detection and transfer of iron traces left by iron items on clothing and human skin. The method is based on the formation of colored complexes between ferrous ions and five synthesized, mostly new triazines. Iron traces originally were left by iron rings on slightly wetted (artificial sweat) cotton fabrics and subsequently transferred to a separate textile substrate. Prior to the use of trazines the contact spots were treated with a new inorganic reducing agent (Sn2+) to reduce Fe3+ to Fe2+. The method is sensitive to detect iron traces on wetted canvas after 10 min contact with iron items. More spectacular results were obtained for traces left on human palm even after very short contact (10 sec). The new iron-trace-transfer method eliminated the contact of triazines solutions with human skin. Transmission visible spectra of Fe(II),triazine complexes were determined. [source]


    5-Acetyl-2-amino-6-methyl-4-phenyl-4H -pyran-3-carbonitrile and 2-amino-5-benzoyl-6-methyl-4-phenyl-4H -pyran-3-carbonitrile acetonitrile solvate

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 12 2006
    Vladimir N. Nesterov
    The syntheses, X-ray structural investigations and calculations of the conformational preferences of the carbonyl substituent with respect to the pyran ring have been carried out for the two title compounds, viz. C15H14N2O2, (II), and C20H16N2O2·C2H3N, (III), respectively. In both mol­ecules, the heterocyclic ring adopts a flattened boat conformation. In (II), the carbonyl group and a double bond of the heterocyclic ring are syn, but in (III) they are anti. The carbonyl group forms a short contact with a methyl group H atom in (II). The dihedral angles between the pseudo-axial phenyl substituent and the flat part of the pyran ring are 92.7,(1) and 93.2,(1)° in (II) and (III), respectively. In the crystal structure of (II), inter­molecular N,H,N and N,H,O hydrogen bonds link the mol­ecules into a sheet along the (103) plane, while in (III), they link the mol­ecules into ribbons along the a axis. [source]


    Evaluation of the antimicrobial activity of cationic polyethylenimines on dry surfaces

    BIOTECHNOLOGY PROGRESS, Issue 5 2008
    Stephen A. Koplin
    Abstract The antimicrobial activity of cationic N -dodecyl- N -methylpolyethylenimine (PEI+) against S. aureus, A. baumannii, and E. coli was evaluated when the polymer was applied as a coating to various surfaces using a paint-like procedure. Antimicrobial activity of PEI+ as a function of time was determined using an assay for long-term survival involving placement of single drops of various bacterial concentrations on dry surfaces. These data were compared with an assay method where bacteria were applied by spraying and surfaces were incubated overnight under agar. PEI+-coated surfaces were found to be highly bactericidal after 30 min when bacteria were sprayed onto surfaces. However, when bacteria were applied as single drops, PEI+-coated surfaces were less biocidal at short contact times particularly for A. baumannii and E. coli. The observations are explained in the context of the difference in drying time between drops deposited on uncoated surfaces and PEI+-coated surfaces and the sensitivity of bacterial survival to dehydration. These results demonstrate that PEI+-coated surfaces are not effectively biocidal for some types of bacteria under certain conditions and that the method of assaying bactericidal efficiency can greatly affect the results obtained. [source]


    New Insights on Near-Infrared Emitters Based on Er-quinolinolate Complexes: Synthesis, Characterization, Structural, and Photophysical Properties,

    ADVANCED FUNCTIONAL MATERIALS, Issue 14 2007
    F. Artizzu
    Abstract Erbium quinolinolates, commonly assumed to be mononuclear species with octahedral co-ordination geometry, have been proposed as promising materials for photonic devices but difficulties in obtaining well defined products have so far limited their use. We report here the conditions to obtain in high yields three different kinds of pure neutral erbium quinolinolates by mixing an erbium salt with 8-quinolinol (HQ) and 5,7-dihalo-8-quinolinol (H5,7XQ: X,=,Cl and Br): i),the trinuclear complex Er3Q9 (1) which is obtained with HQ deprotonated by NH3 in water or ethanol/water mixtures; ii),the already known dimeric complexes based on the unit [Er(5,7XQ)3(H2O)2] [X,=,Cl (2) and Br (3)]; iii) the mononuclear [Er(5,7XQ)2(H5,7XQ)2Cl] [X,=,Cl (4) and Br (5)] complexes, obtained in organic solvents without base addition, where the ion results coordinated to four ligands, two deprotonated chelating, and two as zwitterionic monodentate oxygen donors. These results represent a further progress with respect to a recent reinvestigation on this reaction, which has shown that obtaining pure and anhydrous octahedral ErQ3, the expected reaction product, is virtually impossible, but failed in the isolation of 1 and of the neutral tetrakis species based on H5,7XQ ligands. Structural data provide a detailed description of the molecules and of their packing which involves short contacts between quinoxaline ligands, due to ,,, interactions. Electronic and vibrational studies allow to select the fingerprints to distinguish the different products and to identify the presence of water. The structure/property relationship furnishes a satisfactory interpretation of the photo-physical properties. Experimental evidence confirms that the most important quenchers for the erbium emission are the coordinated water molecules and shows that the ligand emission is significantly affected by the ,,, interactions. [source]


    Characterization of CD4+ T-cell,dendritic cell interactions during secondary antigen exposure in tolerance and priming

    IMMUNOLOGY, Issue 4 2009
    Catherine M. Rush
    Summary Despite the recent advances in our understanding of the dynamics of the cellular interactions associated with the induction of immune responses, comparatively little is known about the in vivo behaviour of antigen-experienced T cells upon secondary antigen exposure in either priming or tolerance. Such information would provide an insight into the functional mechanisms employed by memory T cells of distinct phenotypes and provide invaluable knowledge of how a specific tolerogenic or immunogenic state is maintained. Using real-time imaging to follow the in vivo motility of naďve, primed and tolerized CD4+ T cells and their interactions with dendritic cells (DCs), we demonstrate that each of these distinct functional phenotypes is associated with specific patterns of behaviour. We show that antigen-experienced CD4+ T cells, whether primed or tolerized, display inherently slower migration, making many short contacts with DCs in the absence of antigen. Following secondary exposure to antigen, primed T cells increase their intensity or area of interaction with DCs whereas contacts between DCs and tolerized T cells are reduced. Importantly, this was not associated with alterations in the contact time between DCs and T cells, suggesting that T cells that have previously encountered antigen are more effective at surveying DCs. Thus, our studies are the first to demonstrate that naďve, primed and tolerized T cells show distinct behaviours before and after secondary antigen-encounter, providing a novel mechanism for the increased immune surveillance associated with memory T cells. These findings have important consequences for many immunotherapeutics, which aim to manipulate secondary immune responses. [source]


    Advantageous 3D Ordering of ,-Conjugated Systems: A New Approach Towards Efficient Charge Transport in any Direction,

    ADVANCED MATERIALS, Issue 24 2007
    H. Pang
    A new organic semiconductor based on a benzobisthiazole core has been studied as a hole transport material in field effect transistors; remarkably, the material self-assembles in the solid state to give intermolecular short contacts in all three dimensions. [source]


    Conformational polymorphism in aripiprazole: Preparation, stability and structure of five modifications

    JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 6 2009
    Doris E. Braun
    Abstract Five phase-pure modifications of the antipsychotic drug aripiprazole were prepared and characterized by thermal analysis, vibrational spectroscopy and X-ray diffractometry. All modifications can be produced from solvents, form I additionally by heating of form X° to ,120°C (solid,solid transformation) and form III by crystallization from the melt. Thermodynamic relationships between the polymorphs were evaluated on the basis of thermochemical data and visualized in a semi-schematic energy/temperature diagram. At least six of the ten polymorphic pairs are enantiotropically and two monotropically related. Form X° is the thermodynamically stable modification at 20°C, form II is stable in a window from about 62,77°C, and form I above 80°C (high-temperature form). Forms III and IV are triclinic (), I and X° are monoclinic (P21) and form II orthorhombic (Pna21). Each polymorph exhibits a distinct molecular conformation, and there are two fundamental N,HO hydrogen bond synthons (catemers and dimers). Hirshfeld surface analysis was employed to display differences in intermolecular short contacts. A high kinetic stability was observed for three metastable polymorphs which can be categorized as suitable candidates for the development of solid dosage forms. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:2010,2026, 2009 [source]


    Hydrogen bonding and short contacts in [2,4,6-tris(trifluoromethyl)phenyl]phosphinic acid

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2009
    Stéphanie M. Cornet
    In the title compound, C9H4F9O2P, molecules are linked by a single O,H...O hydrogen bond into chains related to those in phenylphosphinic acid. There are short intramolecular F...P contacts. [source]


    5-(4,5-Ethylenedithio-1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapentalen-2-one (EDTO,TTP) and 5-[4,5-(ethene-1,2-diyldithio)-1,3-dithiol-2-ylidene]-1,3,4,6-tetrathiapentalen-2-one (VDTO,TTP)

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2009
    Hong-Feng Chen
    The title sulfur-rich organic molecular crystals, namely EDTO,TTP (C9H4OS8) and VDTO,TTP (C9H2OS8), are characterized by conjugated C,S bonds and S...S intermolecular short contacts. The planar EDTO,TTP molecules are parallel packed and exhibit strong intermolecular interactions, including side-by-side transverse S...S contacts, face-to-face longitudinal ,,, interactions and C,H...O hydrogen bonding. On cooling the EDTO,TTP crystal from 220 to 120,K, the cell dimensions and the intermolecular distances (such as S...S contacts and especially ,,, spacings) become shorter, while the intramolecular bonds become longer. The curved VDTO,TTP molecules are packed in such a way as to make the crystal fully depolarized. The intermolecular interactions of the VDTO,TTP crystal are relatively weak, because of the weak ,,, interactions and the lack of hydrogen bonding. [source]


    A substituted EDOT precursor: diethyl 3,4-di­hydroxy­thio­phene-2,5-di­carboxyl­ate

    ACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2004
    Christophe Faulmann
    The title compound, C10H12O6S, has been obtained as dark-yellow chunk-shaped crystals, together with the expected thin white needles. The structures of the two phases are identical. Two independent mol­ecules compose the asymmetric unit: one mol­ecule is totally planar, whereas a methyl group of the second mol­ecule points out of the plane. Each mol­ecule participates in several intra- and intermolecular hydrogen bonds and short contacts. The overall structure can be regarded as parallel sheets of mol­ecules. Within a sheet, mol­ecules are connected to one another in an infinite network via numerous short intermolecular contacts. Sheets are connected via hydrogen bonds and short contacts, in particular involving the methyl groups. [source]