Medical and Biomedical Researches

[Persistent positive baciloscopy after several months of tuberculosis therapy: Not always it represe

June 28th, 2008
[Persistent positive baciloscopy after several months of tuberculosis therapy: Not always it represents a treatment failure.] International agencies for tuberculosis (TB) control (WHO, IUATLD, KNCV) consider the presence of acid-fast bacilli (AFB) in the sputum smear after completion of TB therapy as treatment failure. We describe ...

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[Pseudoterranovosis and sushi.]

June 28th, 2008
[Pseudoterranovosis and sushi.] A case of accidental ingestión of Pseudoterranova decipiens is reported, on account of this patient we review main concepts related to this emerging pathology in Chile. Consumption of raw fish in different preparations such as sushi or sashimi, cebiche and seafood is becoming ...

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[Guidelines for the Chagas disease: Part II. Chagas disease in adults, infancy and adolescence.]

June 28th, 2008
[Guidelines for the Chagas disease: Part II. Chagas disease in adults, infancy and adolescence.] The different stages of Chagas disease in adults: acute, undetermined or latent and chronic phases are described. This document contains guidelines for etiological diagnosis of Chagas disease and its treatment. In chronic ...

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[Guidelines for the Chagas disease: Part I. Introduction and epidemiology.]

June 28th, 2008
[Guidelines for the Chagas disease: Part I. Introduction and epidemiology.] The natural existence of this vectorial zoonosis and the development since 1991 of initiatives in the American Region in order to control Chagas Disease, did necessary to prepare this document to update the knowledge about the ...

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[Leuconostoc sp in cancer patients: A descriptive study.]

June 28th, 2008
[Leuconostoc sp in cancer patients: A descriptive study.] The species of Leuconostoc are uncommon opportunistic pathogens, which can be isolated in critically ill patients, immunocompromised hosts and in nosocomial infections. They are mostly isolated in bacteremia associated to intravascular devices and to the use of total ...

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[¿Is it necessary to perform a lumbar puncture in the evaluation of the febrile newborn infant with

June 28th, 2008
[¿Is it necessary to perform a lumbar puncture in the evaluation of the febrile newborn infant without source?] Lumbar puncture to detect bacterial meningitis is a recommended screening procedure to be performed in febrile newborn infants at admission to hospital. Objective: To evaluate the usefulness of ...

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[Antimicrobial susceptibility and resistance patterns of Staphylococcus aureus isolated from patient

June 28th, 2008
[Antimicrobial susceptibility and resistance patterns of Staphylococcus aureus isolated from patients and carriers in Valdivia city, Chile.] In vitro susceptibility of nosocomial and community acquired strains of Staphylococcus aureus must be periodically evaluated because of its continuous evolution. Aim: To know the antimicrobial susceptibility of S. ...

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[Epidemiology and laboratory: a different point o view of public health in Chile.]

June 28th, 2008
[Epidemiology and laboratory: a different point o view of public health in Chile.] The authors present an abridged history from their personal point of view of public health dealing with communicable diseases in Chile, in reference to an article previously published in Revista Chilena de Infectología. ...

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[Epidemiology of human immunodeficiency virus infection and AIDS in Chile.]

June 28th, 2008
[Epidemiology of human immunodeficiency virus infection and AIDS in Chile.] In Chile, the first cases of AIDS were reported 23 years ago, and since then, through December 2006, 17.235 persons have been notified with HIV infection or AIDS(1). To the year 2005, there have been 5.288 ...

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[Diagnosis of congenital syphilis at delivery: Maternal serum or cord blood?]

June 28th, 2008
[Diagnosis of congenital syphilis at delivery: Maternal serum or cord blood?] Congenital syphilis (CS) is an important health problem in Chile, with a rate of 0.25/1,000 live newborn (NB) during year 2004. In 2000, the Chilean Ministry of Public Health recommended to perform a screening in ...

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Structural and catalytic studies of lithium complexes bearing pendant aminophenolate ligands.

June 28th, 2008
Structural and catalytic studies of lithium complexes bearing pendant aminophenolate ligands. Lithium complexes bearing mono-anionic aminophenolate ligands are described. Reactions of ligand precursors HON(Me)Ph(OMe), HON(Me)Ph(SMe), HON(Me)C(OMe) or HON(Me)C(NMe2) [HON(Me)Ph(OMe) = (2-OMeC(6)H(4)CH(2))N(Me)(CH(2)-2-HO-3,5-C(6)H(2)((t)Bu)(2)); HON(Me)Ph(SMe)= (2-SMe-C(6)H(4)CH(2))N(Me)(CH(2)-2-HO-3,5-C(6)H(2)((t)Bu)(2)); HON(Me)C(OMe) = (MeOCH(2)CH(2))N(Me)(CH(2)-2-HO-3,5-C(6)H(2)((t)Bu)(2)); HON(Me)C(NMe2) = (Me(2)NCH(2)CH(2))N(Me)(CH(2)-2-HO-3,5-C(6)H(2)((t)Bu)(2))] with 1.1-1.3 molar equivalents of (n)BuLi in ...

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Synthesis and structures of crystalline Li, Al and Sn(ii) 1-azaallyls and beta-diketiminates derived

June 28th, 2008
Synthesis and structures of crystalline Li, Al and Sn(ii) 1-azaallyls and beta-diketiminates derived from [Li{mu,eta(3)-N(SiMe(3))C(Ad)C(H)SiMe(3)}](2) (Ad = 1-adamantyl). The crystalline dimeric 1-azaallyllithium complex [Li{mu,eta(3)-N(SiMe(3))C(Ad)C(H)SiMe(3)}](2) () was prepared from equivalent portions of Li[CH(SiMe(3))(2)] and 1-cyanoadamantane (AdCN). Complex was used as precursor to each of the crystalline complexes ...

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Selenoether macrocyclic chemistry-syntheses and properties of new potentially tridentate and hexaden

June 28th, 2008
Selenoether macrocyclic chemistry-syntheses and properties of new potentially tridentate and hexadentate Se/O-donor macrocycles. Treatment of O(CH(2)CH(2)SeCN)(2) with Na in NH(3)(l), followed by dropwise addition of a thf solution of o-C(6)H(4)(CH(2)Br)(2) at -40 degrees C leads to formation of three mixed Se/O-donor macrocycles which are separable by ...

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Phosphazene vs.diazaphospholene PN-bond cleavage in spirocyclic cyclodiphosphazenes.

June 28th, 2008
Phosphazene vs.diazaphospholene PN-bond cleavage in spirocyclic cyclodiphosphazenes. Thermolysis of 2-azido-1,3,2-diazaphospholenes offers access to novel and rare spirocyclic cyclodiphosphazenes. The spectroscopic data and X-ray structure of one representative of the 2-azido-1,3,2-diazaphospholenes reveals an ionic bonding situation explaining sufficiently its rather high thermal stability. The cyclodiphosphazenes were characterised ...

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Synthesis and characterization of cationic selenium-nitrogen heterocycles from tert-butyl-DAB (DAB =

June 28th, 2008
Synthesis and characterization of cationic selenium-nitrogen heterocycles from tert-butyl-DAB (DAB = 1,4-di-tert-butyl-1,3-diazabutadiene) and SeX(4)via the reductive elimination of X(2) (X = Cl, Br): a distinct contrast with tellurium. The synthesis and comprehensive characterisation of a series of 1,2,5-selenadiazolium salts, which were generated from the direct reaction ...

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N-Heterocyclic phosphenium cations: syntheses and cycloaddition reactions.

June 28th, 2008
N-Heterocyclic phosphenium cations: syntheses and cycloaddition reactions. A series of trifluoromethanesulfonate (OTf) salts of N-heterocyclic phospheniums (NHP) bearing phenyl (), para-methoxyphenyl (), 2,6-diisopropylphenyl () and mesityl () substituents is reported. The compounds are made by a modification to a literature procedure that improves the overall yields ...

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Tuning the electronic properties of cyclopentadienyl analogs with CB(2)N(2) frameworks: 1,2-diphenyl

June 28th, 2008
Tuning the electronic properties of cyclopentadienyl analogs with CB(2)N(2) frameworks: 1,2-diphenyl-1,2-diaza-3,5-diborolyl ligands and their alkali metal salts. Two heterocyclic cyclopentadienyl analogs with a CB(2)N(2) skeleton, 4-methyl-1,2,3,5-tetraphenyl-1,2-diaza-3,5-diborolidine and 4-methyl-3,5-dimethylamino-1,2-diphenyl-1,2-diaza-3,5-diborolidine were prepared through cyclocondensation of the corresponding 1,1-bis(organochloroboryl)ethane with 1,2-diphenylhydrazine. The former diazadiborolidine featured a cyclopentadiene-like structure with ...

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Host-guest interactions in a series of self-assembled As(2)L(2)Cl(2) macrocycles.

June 28th, 2008
Host-guest interactions in a series of self-assembled As(2)L(2)Cl(2) macrocycles. The reaction of AsCl(3) with H(2)L (where L = a rigid dithiolate) results in the self-assembly of As(2)L(2)Cl(2) supramolecular macrocycles. For ligands 4,4\'-bis(mercaptomethyl)biphenyl (H(2)), 4,4\'-bis(mercaptomethyl)-trans-stilbene (H(2)), and 1,4-dimethoxy-2,5-bis(mercaptomethyl)benzene (H(2)), the macrocyclic cavities of the resulting assemblies are ...

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Electronic structure of the glyoxalbis(2-hydroxyanil) (gha) ligand in [Co(III)(gha)(PPh(3))(2)](+):

June 28th, 2008
Electronic structure of the glyoxalbis(2-hydroxyanil) (gha) ligand in [Co(III)(gha)(PPh(3))(2)](+): radical vs. non-radical states. The synthesis, structure and spectroscopic properties of a complex salt [Co(III)(gha)(PPh(3))(2)][Co(II)Cl(3)(PPh(3))].C(2)H(5)OH () are reported; gha = glyoxalbis(2-hydroxyanil). This is the first single crystal X-ray structure of a (gha)(2-) complex with a transition element. ...

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Manipulation of molecular aggregation and supramolecular structure using self-assembled lithium mixe

June 28th, 2008
Manipulation of molecular aggregation and supramolecular structure using self-assembled lithium mixed-anion complexes. A set of zero-, one-, two-, and three-dimensional materials have been synthesized by systematically varying the stoichiometry of the two components 2,4,6-Me(3)-C(6)H(2)OLi (ArOLi) and Me(2)N(CH(2))(2)OLi (ROLi) within single aggregates, while using 1,4-dioxane (diox) as ...

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Nucleophilic substitution reactions of the tricyclic triphosphorus cage P(3)(CBu(t))(2): a novel rou

June 28th, 2008
Nucleophilic substitution reactions of the tricyclic triphosphorus cage P(3)(CBu(t))(2): a novel route to polyphosphorus phosphenium complexes. Substitution of Cl(-) in the tricyclic triphosphorus cage Cl(P(1))-P(3)(CBu(t))(2) by a range of both anionic and neutral nucleophiles has been investigated. With anionic nucleophiles, reaction with fluoride and hydride anion ...

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Heteroleptic metal alkoxide “oxoclusters” as molecular models for the sol-gel synthesis of perovsk

June 28th, 2008
Heteroleptic metal alkoxide \"oxoclusters\" as molecular models for the sol-gel synthesis of perovskite nanoparticles for bio-imaging applications. Systematic structural study of the molecules, resulting from microhydrolysis of heterometallic beta-diketonate alkoxides of barium and strontium (single-source precursors of perovskite oxide materials), demonstrates that the structures of these ...

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Toward selective functionalisation of oligosilanes: borane-catalysed dehydrogenative coupling of sil

June 28th, 2008
Toward selective functionalisation of oligosilanes: borane-catalysed dehydrogenative coupling of silanes with thiols. Among established methods for transforming Si-H bonds, carbonyl hydrosilylation and heterodehydrogenative coupling with alcohols catalysed by B(C(6)F(5))(3) are shown to provide exceptionally clean routes to the derivatisation of tetra-substituted disilanes such as [Ph(2)SiH](2), giving ...

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Charge separation by ditopic complexation in the solid state: molecular structure of {Ph(2)(I)SnCH(2

June 28th, 2008
Charge separation by ditopic complexation in the solid state: molecular structure of {Ph(2)(I)SnCH(2)Sn(Ph)(I)CH(2)-[16]-crown-5}.NaF.CH(3)OH. An intramolecular O-HF hydrogen bridge involving a methanol molecule provides communication between the strongly separated sodium cation and fluoride anion in sodium fluoride that is, for the first time and despite its high ...

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Hydride encapsulation by molecular alkali-metal clusters.

June 28th, 2008
Hydride encapsulation by molecular alkali-metal clusters. The sequential treatment of group 12 and 13 Lewis acids with alkali-metal organometallics is well established to yield so-called \'\'ate\' complexes, whereby the Lewis-acid metal undergoes nucleophilic attack to give an anion, at least one group 1 metal acting to ...

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