Biomedical subjects

J Valls

Publications and source records attributed to J Valls.

At least 19 recordsLinked to original sources

PubMed2005

Influence of ethanol concentration on the extraction of color and phenolic compounds from the skin and seeds of Tempranillo grapes at different stages of ripening.

The aim of this paper is to study how grape ripeness and ethanol concentration affect the extraction of color and phenolic compounds from skins and seeds during the maceration/fermentation process. Simulated maceration assays were carried out with the grapes at three stages of berry development (vitis vinifera cv. Tempranillo) and different percentages of ethanol in the maceration media. Both ripeness and ethanol content have a considerable effect on the extraction of color and phenolic compounds. Of these two factors, ripeness increases the extractability most. The presence of ethanol in the medium facilitates anthocyanin and especially proanthocyanidin extraction, but it also decreases copigmentation phenomena, which can decrease the color intensity. The higher the ethanol concentration is in the maceration media, the higher the astringency of proanthocyanidins.

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PubMed2002

[Results of using botulism toxin in the treatment of spasmodic dysphonia].

Spasmodic Dysphonia (SD) is a dystonia involving laryngeal musculature thus causing a characteristic voice disorder. Two main types of SD have been described. The adductor type is the commonest and it is characterized by a strain-strangle, choked voice. The abductor type can be distinguished from the previous one by episodes of a blown and whispering voice, interrupting speech. Botulism toxin (BTX) has demonstrated to be the most effective treatment for this condition. Thirty patients diagnosed of SD (twenty-nine adductor type/one abductor type) were included. Their degree of dysphonia was evaluated using both functional and visual-analogue scales. They were treated with BTX vocal cord injections using a percutaneous technique under EMG guidance. Improvements up to a 100% of the normal vocal function were obtained, with an average of 82% in the adductor type. The adverse effects were mild and transient. Hypophonia affected 61.3% of patients lasting an average of 11.3 days. Dysphagia was reported in 44.1% of cases lasting an average of 5.8 days.

Adult↗

PubMed2002

Simulation modelling of bacterial growth in yoghurt.

INDISIM, an individual-based simulator, was used to specifically study the influence of the shape and size of Streptococcus salivarius subsp. thermophilus and Lactobacillus delbrueckii subsp. bulgaricus in yoghurt processing. To this effect, two different sets of simulations were carried out. In the first set of simulations, it was assumed that the initial acidity of the medium has the same value as the acidity of the cytoplasm of the microorganisms. Hence, the differences in bacterial growth by the two species are only attributable to differences in their geometry. It was found that, in an optimum culture, the growth in biomass of S. salivarius subsp. thermophilus is larger than that of L. delbrueckii subsp. bulgaricus. An important factor for understanding this difference might be the larger mass-to-surface ratio of the former. In the second set of simulations, a simplified model of yoghurt, the parametrisation differs both in the geometry and the metabolism of the two species. The results of these simulations are in very good qualitative agreement with the experimental data of [Lait 69 (1989) 519]. Finally, by inhibiting the uptake of amino acids by S. salivarius subsp. thermophilus, the large relative importance of lactic acid in yoghurt processing was highlighted.

Biomass↗

PubMed2001

Dramatic improvement of POEMS syndrome following autologous haematopoietic cell transplantation.

POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, serum monoclonal protein and skin changes) is a rare plasma cell disorder of unknown pathogenesis and is diagnosed by the demonstration of a plasma cell proliferation at the biopsy of an osteoesclerotic lesion. When the lesions are in a limited area, radiation therapy is usually highly effective. Patients with disseminated disease require systemic chemotherapy, which is not effective in most cases. A patient with severe widespread POEMS syndrome resistant to melphalan who experienced a dramatic improvement after high-dose melphalan followed by autologous haematopoietic cell transplantation (AHCT) is reported. We believe that this is the first reported case of POEMS syndrome treated with AHCT, a procedure that could be considered in similarly affected patients.

Adult↗

PubMed2000

Measurement of the decay amplitudes of B0 --> J/psiK*0 and B(s)(0) --> J/psistraight phi decays

An angular analysis of B0-->J/psiK(*0) and B(0)(s)-->J/psistraight phi has been used to determine the decay amplitudes with parity-even longitudinal ( A0) and transverse ( A( parallel)) polarization and parity-odd transverse ( A( perpendicular)) polarization. The measurements are based on 190 B0 and 40 B(0)(s) candidates obtained from 89 pb(-1) of &pmacr;p collisions at the Fermilab Tevatron. The longitudinal decay amplitude dominates with |A0|(2) = 0.59+/-0. 06+/-0.01 for B0 and |A0|(2) = 0.61+/-0.14+/-0.02 for B(0)(s) decays. The parity-odd amplitude is found to be small with |A( perpendicular)|(2) = 0.13(+0.12)(-0.09)+/-0.06 for B0 and |A( perpendicular)|(2) = 0.23+/-0.19+/-0.04 for B(0)(s) decays.

Journal Article↗

PubMed2000

Dijet production by double pomeron exchange at the fermilab tevatron

We report the first observation of dijet events with a double Pomeron exchange topology produced in &pmacr;p collisions at sqrt[s] = 1800 GeV. The events are characterized by a leading antiproton, two jets in the central pseudorapidity region, and a large rapidity gap on the outgoing proton side. We present results on jet kinematics and production rates, compare them with corresponding results from single diffractive and inclusive dijet production, and test factorization.

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PubMed2000

Direct measurement of the W boson width in p&pmacr; collisions at radicals = 1.8 TeV

This Letter describes a direct measurement of the W boson total decay width, gamma(W), using the Collider Detector at Fermilab. The measurement uses an integrated luminosity of 90 pb(-1), collected during the 1994-1995 run of the Fermilab Tevatron p&pmacr; collider. The width is determined by normalizing predicted signal and background distributions to 49 844 W-->enu candidates and 21 806 W-->&mgr;nu candidates in the transverse-mass region M(T)<200 GeV and then fitting the predicted shape to the 438 electron events and 196 muon events in the high- M(T) region, 100<M(T)<200 GeV. The result is gamma(W) = 2.04+/-0.11(stat)+/-0.09(syst) GeV.

Journal Article↗

PubMed2000

Search for second and third generation leptoquarks including production via technicolor interactions in p&pmacr; collisions at radicals = 1.8 TeV

We report the results of a search for second and third generation leptoquarks using 88 pb(-1) of data recorded by the Collider Detector at Fermilab. Color triplet technipions, which play the role of scalar leptoquarks, are investigated due to their potential production in decays of strongly coupled color octet technirhos. Events with a signature of two heavy flavor jets and missing energy may indicate the decay of a second (third) generation leptoquark to a charm (bottom) quark and a neutrino. As the data are found to be consistent with standard model expectations, mass limits are determined.

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PubMed2000

Search for new particles decaying to t&tmacr; in p&pmacr; collisions at radicals = 1.8 TeV

We use 106 pb (-1) of data collected with the Collider Detector at Fermilab to search for narrow-width, vector particles decaying to a top and an antitop quark. Model independent upper limits on the cross section for narrow, vector resonances decaying to t&tmacr; are presented. At the 95% confidence level, we exclude the existence of a leptophobic Z' boson in a model of top-color-assisted technicolor with mass M(Z')<480 GeV/c(2) for natural width gamma = 0.012M(Z'), and M(Z')<780 GeV/c(2) for gamma = 0.04M(Z').

Journal Article↗

PubMed2000

Limits on light gravitino production and new processes with large missing transverse energy in p&pmacr; collisions at sqrt

Events collected by the Collider Detector at Fermilab (CDF) with an energetic jet plus large missing transverse energy can be used to search for physics beyond the standard model. We see no deviations from the expected backgrounds and set upper limits on the production of new processes. We consider in addition the production of light gravitinos and set a limit at 95% confidence level on the breaking scale sqrt[F]>/=217 GeV, which excludes gravitino masses smaller than 1.1x10(-5) eV/c(2).

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PubMed2000

Search for scalar top quark production in p&pmacr; collisions at sqrt

We have searched for direct production of scalar top quarks at the Collider Detector at Fermilab in 88 pb(-1) of p&pmacr; collisions at sqrt[s] = 1.8 TeV. We assume the scalar top quark decays into either a bottom quark and a chargino or a bottom quark, a lepton, and a scalar neutrino. The event signature for both decay scenarios is a lepton, missing transverse energy, and at least two b-quark jets. For a chargino mass of 90 GeV/c(2) and scalar neutrino masses of at least 40 GeV/c(2), we find no evidence for scalar top production and present upper limits on the production cross section in both decay scenarios.

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PubMed2000

Diffractive dijets with a leading antiproton in &pmacr;p collisions at sqrt

We report results from a study of events with a leading antiproton of beam momentum fraction 0.905 7 GeV. Using the dijet events, we evaluate the diffractive structure function of the antiproton and compare it with expectations based on results obtained in diffractive deep inelastic scattering experiments at the DESY ep collider HERA.

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PubMed2000

Production of Upsilon(1S) mesons from chi(b) decays in p&pmacr; collisions at sqrt

We have reconstructed the radiative decays chi(b)(1P)-->Upsilon(1S)gamma and chi(b)(2P)-->Upsilon(1S)gamma in p&pmacr; collisions at sqrt[s] = 1.8 TeV, and measured the fraction of Upsilon(1S) mesons that originate from these decays. For Upsilon(1S) mesons with p(Upsilon)(T)>8.0 GeV/c, the fractions that come from chi(b)(1P) and chi(b)(2P) decays are [27.1+/-6.9(stat)+/-4. 4(syst)]% and [10.5+/-4.4(stat)+/-1.4(syst)]%, respectively. We have derived the fraction of directly produced Upsilon(1S) mesons to be [50.9+/-8.2(stat)+/-9.0(syst)]%.

Journal Article↗

PubMed2000

Search for color singlet technicolor particles in p&pmacr; collisions at radicals = 1.8 TeV

We search for color singlet technirho and technipion production in p&pmacr; collisions at sqrt[s] = 1.8 TeV recorded with the Collider Detector at Fermilab. These exotic technimesons are present in a model of walking technicolor. The signatures studied are lepton plus two jets plus E(T) and multijet final states. No excess of events is seen in either final state. We set an upper limit on the technirho production cross section and exclude a region in the technipion mass versus technirho mass plane.

Journal Article↗

PubMed2000

Search for a fourth-generation quark more massive than the Z0 boson in p&pmacr; collisions at radicals = 1.8 TeV

We present the results of a search for pair production of a fourth-generation charge -1 / 3 quark (b(')) in sqrt[s] = 1.8 TeV p&pmacr; collisions using 88 pb(-1) of data obtained with the Collider Detector at Fermilab. We assume that both quarks decay via the flavor-changing neutral current process b(')-->bZ(0) and that the b(') mass is greater than m(Z)+m(b). We studied the decay mode b(')b(');-->Z(0)Z(0)b&bmacr; where one Z0 decays into e(+)e(-) or &mgr;(+)&mgr;(-) and the other decays hadronically, giving a signature of two leptons plus jets. An upper limit on the sigma(p&pmacr;-->b(')b(');)x[B(b(')-->bZ(0))](2) is established as a function of the b(') mass. We exclude at 95% confidence level a b(') quark with mass between 100 and 199 GeV/c(2) for B(b(')-->bZ(0)) = 100%.

Journal Article↗

PubMed2000

Measurement of the helicity of W bosons in top quark decays

We use the transverse momentum spectrum of leptons in the decay chain t-->bW with W-->lnu to measure the helicity of the W bosons in the top quark rest frame. Our measurement uses a t&tmacr; sample isolated in 106+/-4 pb(-1) of data collected in p&pmacr; collisions at sqrt[s] = 1.8 TeV with the CDF detector at the Fermilab Tevatron. Assuming a standard V-A weak decay, we find that the fraction of W's with zero helicity in the top rest frame is F0 = 0.91+/-0. 37(stat)+/-0.13(syst), consistent with the standard model prediction of F0 = 0.70 for a top mass of 175 GeV/c(2).

Journal Article↗

PubMed2000

Observation of diffractive b-quark production at the fermilab tevatron

We report a measurement of the fraction of b quarks produced diffractively in &pmacr;p collisions at sqrt[s] = 1.8 TeV. Diffraction is identified by the absence of particles in a forward pseudorapidity region. From events with an electron of transverse momentum 9.5<p(e)(T)<20 GeV/ c within the pseudorapidity region |eta|<1.1, the ratio of diffractive to total b-quark production rates is found to be R(&bmacr;b) = [0.62+/-0.19(stat)+/-0.16(syst)]%. This result is comparable in magnitude to corresponding ratios for W and dijet production but significantly lower than expectations based on factorization.

Journal Article↗

PubMed2000

Assessment of dysfunctional working models of self and others in schizophrenic patients: a summary of data collected in nine nations. International Research Group.

OBJECTIVE: To investigate the cross-cultural feasibility of a new scale for assessing dysfunctional working models of self and others, and to evaluate its discriminative power. METHOD: Schizophrenic patients (N=351), non-psychotic patients (N= 86) and non-clinical subjects (N= 511) collected in 10 centres completed the DWM-S. Current psychopathology was assessed by means of the BPRS. RESULTS: Alpha coefficients were high in all samples. Mean scores on the DWM-S appeared to be comparable in all countries, suggesting cross-national generalizability. No significant correlation was found with sex, age, levels of psychopathology and duration of illness. Discriminant analyses showed that more than 70% of the schizophrenic patients are correctly classified. CONCLUSION: The DWM-S is an easily administered self-report instrument which allows to pinpoint internal dysfunctional working models of self and others in various types of patients. It is a useful tool for case conceptualization, especially when psychotherapeutic interventions are part of the treatment programme.

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