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B Valdés

Publications and source records attributed to B Valdés.

12 recordsLinked to original sources
PubMed2005

Automatic and controlled semantic processing: a masked prime-task effect.

A classical definition of automaticity establishes that automatic processing occurs without attention or consciousness, and cannot be controlled. Previous studies have demonstrated that semantic priming can be reduced if attention is directed to a low-level of analysis. This finding suggests that semantic processing is not automatic since it can be controlled. In this paper, we present two experiments that demonstrate that semantic processing may occur in the absence of attention and consciousness. A negative semantic priming effect was found when a low-level prime-task was required and when a masked lexical decision prime-task was performed (Experiment 1). This paper also discusses the limitations of the inhibitory mechanism involved in negative semantic priming effect.

Adolescent↗
PubMed2001

Improvement of the synthesis of diphenylmethyl 7beta-(o-hydroxy)benzylideneamino-3-hydroxymethyl-3-cephem-4-carboxylate.

The title product (I) is synthesized currently from 7-aminocephalosporanic acid, and diphenyldiazomethane (DDM) is used as a protective reagent of the acid function for further reactions. When DDM was prepared from benzophenone hydrazone by reaction with chloramine T, it was resulted impure by p-toluenesulfonamide, formed as side product, which cannot be removed during the final purification step carried out according to the literature procedure. Two simple methods are proposed here to obtain I with the suitable degree of purity necessary for a drug.

Benzene↗
PubMed2000

Synthesis of (Z)-2-(2-formamido-4-thiazolyl)-2-(substituted alkoxyimino) acetic acids.

(Z)-2-(2-formamido-4-thiazolyl)-2-(substituted alkoxyimino) acetic acids were synthesized by a new method based on the following sequence of reactions: treatment of the tert-butyl acetoacetate with sodium nitrite, alkylation of the oxime formed with an appropriate alkyl halide, halogenation of methyl alpha-keto group and simultaneous cleavage of tert-butyl ester with sulfuryl chloride, protection of the obtained acid function with diphenyldiazomethane, formation of the 2-aminothiazole ring by the Hantzsch method with thiourea, formylation of the amino group and selective final cleavage of the diphenylmethyl ester by treatment with trifluoroacetic acid and anisol. The developed procedure allows the synthesis of (Z)-2-(2-formamido-4-thiazolyl)-2-(substituted alkoxyimino) acetic acids, with an ester function in the alkoxyimino group employing a simple method and obtaining higher yields in comparison with the habitually used classic method.

Acetates↗
PubMed1997

[The association of beta zero-thalassemia and Hb D Punjab in a family of Indian origin. The second case reported in Spain].

The present report described the hematologic and molecular study of the second case of Hb D-Punjab associated with a beta zero-thalassemia found in Spain and the first case in which the mutations have been identified at molecular level. A family from India is studied, which is constituted by mother (I2) and 3 children (II1, II2 and II3). The molecular characterization of the hemoglobinopathy was made by electrophoretic and chromatographic techniques and confirmed by sequencing of the beta-globin gene. The mutation causer of the beta-thalassemia was studied by PCR-ARMS. The mother (I2) and one of her child (II2) are carriers of the gene for beta zero-thalassemia owing to the frameshift CD 8/9 mutation (+ G). Other of them (II1) is heterozygous for Hb D-Punjab without beta-thalassemia association. The third child (II3) knows a double heterozygote state for Hb D-Punjab/beta zero-thalassemia (hemoglobin D-thalassemia). In spite of the patient with hemoglobin D-thalassemia has 94.5% of Hb D, without Hb A, the hematologic picture belongs to thalassemia trait with moderate haemolytic anemia, intense microcytosis and hypochromia and numerous target cells. This hematologic picture discloses the mildness of the Hb D-Punjab, but the reliable responsible for the phenotype is the disbalance in the synthesis of globin chains, because of frameshift CD 8/9 mutation (+ G) beta zero-thalassemia mutation.

Adult↗
PubMedDate not supplied

Ligustrum lucidum Ait. f. leaves as a bioindicator of the air-quality in a Mediterranean city.

The concentration of 11 elements, Ba, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Zn and V, have been determined in leaves of Ligistrum lucidum Ait. f. growing in Palermo, by simultaneous inductively coupled plasma mass spectrometry. A total of 72 samples from six different sites were investigated to deduce the bioindicator ability of this species. Differences were found in the element concentrations in the leaves from the different sites and, in general, anthropogenic pollutant patterns match traffic levels. This paper describes and discusses the spatio-variations of the different elements. Cluster analyses established three different groups giving an idea about the origins of the elements. Results demonstrate that this species is useful as a bioindicator in a Mediterranean climate, especially as it has the added advantage of being an evergreen tree.

Air Pollutants↗
PubMedDate not supplied

[Treatment of status epilepticus with rectally administered diazepam].

Rectal administration of diazepam is a good alternative to intravenous acute treatment in severe epileptic crises, but there is scarce information about its usefulness in status epilepticus. Treatment with rectal diazepam, 0.6 to 0.8 mg x kg of body weight as a single drug, in 10 children with 13 episodes of status epilepticus, defined as epileptic crises lasting 30 or more minutes (ten of these were generalized tonic and clonic, two were unilateral tonic and clonic, and one was of the partial complex type) is described. Nine status epilepticus episodes subsided at an average 4.4 minutes after the drug was given; in 3 cases there were no favourable effects, and one case recurred after initial response. There were no significant complications, with the exception of slight respiratory depression in a patient with encephalitis. In spite of the small size of the sample, these results suggest that rectal diazepam is an effective alternative to intravenous drug administration in the management of status epilepticus whenever venous access is difficult.

Administration, Rectal↗
PubMedDate not supplied

[Urodynamics in children with recurrent urinary infection, enuresis and bladder incontinence].

Clinical and urodynamic findings in 50 children with normal neurologic examination and: enuresis (n = 5), vesical incontinence (n = 2), recurrent urinary tract infection (n = 10) or association of these abnormalities (n = 33) are described. Renal ultrasonography showed bilateral hydronephrosis in a girl with hypotonic bladder. Reflux nephropathy was detected in two children with vesical hyperactivity and in one patient with hypotonic bladder. Vesical residue was evident in 5 patients with hyperactive bladder. Increased bladder capacity occurred in two children with hypotonic response. Vesical neck formation was observed along micturition in 6 patients with hyperactive bladder. Hyperactive bladder response occurred in 5/5 patients with enuresis, in 1/2 children with vesical incontinence (VI), in 8/10 cases of recurrent urinary tract infection (RUTI) and in 23/33 patients with combined symptoms (CS). Hypertonic response was seen in 1/2 VI, 1/10 RUTI and 5/33 CS patients. Finally in 1/10 RUTI and in 5/33 CS cases bladders were hypotonic and 4/33 CS showed normal urodynamic findings.

Adolescent↗