Biomedical subjects

M Barbero

Publications and source records attributed to M Barbero.

At least 19 recordsLinked to original sources

PubMed2006

Measurement of D0-->pilnu(Klnu) form factors and absolute branching fractions.

Using a 282 fb-1 data sample collected by the Belle experiment at the KEKB e+e- collider, we study D0 decays to K-l+nu and pi-l+nu final states. The D0 flavor and momentum are tagged through a full reconstruction of the recoiling charm meson and additional mesons from fragmentation. The reconstruction method provides very good resolution in neutrino momentum and in q2=(pl+pnu)2. Normalizing to the total number of D0 tags, we measure the absolute branching fractions to be B(D0-->Klnu)=(3.45+/-0.07stat+/-0.20syst)% and B(D0-->pilnu)=(0.255+/-0.019stat+/-0.016syst)% and the semileptonic form factors (within the modified pole model) f+K(0)=0.695+/-0.007stat+/-0.022syst and f+pi(0)=0.624+/-0.020stat+/-0.030syst.

Journal Article↗

PubMed2006

Evidence for B-->eta'pi and improved measurements for B-->eta'K.

We report evidence for the exclusive two-body charmless hadronic B meson decay B-->eta'pi, and improved measurements of B-->eta'K. The results are obtained from a data sample of 386x10(6) BB pairs collected at the Upsilon(4S) resonance, with the Belle detector at the KEKB asymmetric-energy e+e- collider. We measure B(B+-->eta'pi+)=[1.76(-0.62)(+0.67)(stat)(-0.14)(+0.15)(syst)]x10(-6) and B(B0-->eta'pi0)=[2.79(-0.96)(+1.02)(stat)(-0.34)(+0.25)(syst)]x10(-6). We also find the ratio of B(B+-->eta'K+)/B(B0-->eta'K0)=1.17+/-0.08(stat)+/-0.03(syst) and measure the direct CP asymmetries for the charged modes.

Journal Article↗

PubMed2006

Evidence for large direct CP violation in B+/- --> rho(770)0K+/- from analysis of three-body charmless B+/- --> K+/-pi+/-pi+/- decays.

We report results on a Dalitz analysis of three-body charmless B+/- --> K+/-pi+/-pi+/- decay including searches for direct CP violation. We report the first observation of the decay B+/- --> f2(1270)K+/- with a statistical significance above 6sigma. We also observe first evidence for large direct CP violation in the B+/- --> rho(770)0K+/- channel. The results are obtained with a data sample that contains 386 10(6) BB pairs collected at the Y(4s) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider.

Journal Article↗

PubMed2006

Measurement of forward-backward asymmetry and Wilson coefficients in B --> K*l+l-.

We report the first measurement of the forward-backward asymmetry and the ratios of Wilson coefficients and in A9/A7 and A10/A7 in B --> K*l+l-, where l represents an electron or a muon. We find evidence for the forward-backward asymmetry with a significance of 3.4sigma. The results are obtained from a data sample containing 386 x 10(6) BB pairs that were collected on the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider.

Journal Article↗

PubMed2006

Observation of b-->dgamma and determination of /Vtd/Vts/.

We report the observation of the flavor-changing neutral current process b-->dgamma using a sample of 386 x 106 B meson pairs accumulated by the Belle detector at the KEKB e+e- collider. We measure branching fractions for the exclusive modes B--->rho-gamma, B0rho0gamma, and B0omegagamma. Assuming that these three modes are related by isospin, we find B(B-->(rho,gamma)gamma)=[Formula: See Text] with a significance of 5.1sigma. This result is used to determine the ratio of Cabibbo-Kobayashi-Maskawa matrix elements /Vtd/Vts/ to be [Formula: See Text].

Journal Article↗

PubMed2006

Improved constraints on D0-D0 mixing in D0 --> K+ pi- decays from the Belle detector.

We report the results of a search for D0-D0 mixing in D0 --> K+ pi- decays based on 400 fb(-1) of data accumulated by the Belle detector at KEKB. Both assuming CP conservation and allowing for CP violation, we fit the decay-time distribution for the mixing parameters x and y, as well as for the parameter R(D), the ratio of doubly Cabibbo-suppressed decays to Cabibbo-favored decays. The 95% confidence level region in the (x'2,y') plane is obtained using a frequentist method. Assuming CP conservation, we find x'2 < 0.72 x 10(-3) and -9.9 x 10(-3) < y' < 6.8 x 10(-3) at the 95% confidence level; these are the most stringent constraints on the mixing parameters to date. The no-mixing point (0,0) has a confidence level of 3.9%. Assuming no mixing, we measure R(D) = (0.377 +/- 0.008 +/- 0.005)%.

Journal Article↗

PubMed2005

Determination of /Vub/ from measurements of the inclusive charmless semileptonic partial rates of B mesons using full reconstruction tags.

We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element /Vub/, based on 253 fb(-1) of data collected by the Belle detector at the KEKB e+ e- asymmetric collider. Events are tagged by fully reconstructing one of the B mesons, produced in pairs from Gamma(4S). The signal for b --> u semileptonic decay is distinguished from the b --> c background using the hadronic mass Mx, the leptonic invariant mass squared q2 and the variable P+ [triple bond] Ex - /px/. The results are obtained for events with p(l)* > or = 1 GeV/c, in three kinematic regions (1) Mx < 1.7 GeV/c2, (2) Mx < 1.7 GeV/c2 combined with q2 > 8 GeV2/c2, and by (3) P+ < 0.66 GeV/c. The matrix element /Vub/ is found to be (4.09 +/- 0.19 +/- 0.20(+0.14) -0.15 +/- 0.18) x 10(-3), where the errors are statistical, systematic including Monte Carlo modeling, theoretical, and from shape function parameter determination, respectively.

Journal Article↗

PubMed2005

Measurements of B decays to two kaons.

We report measurements of B meson decays to two kaons using 253 fb(-1) of data collected with the Belle detector at the KEKB energy-asymmetric e+ e- collider. We find evidence for signals in B+ --> K0 K+ and B0 --> K0 K0 with significances of 3.0sigma and 3.5sigma, respectively. (Charge-conjugate modes are included.) The corresponding branching fractions are measured to be [symbol: see text](B+ --> K0 K+) = (1.0 +/- 0.4 +/- 0.1) x 10(-6) and [symbol: see text](B0 --> K0 K0) = (0.8 +/- 0.3 +/- 0.1) x 10(-6). These decay modes are examples of hadronic bd transitions. No signal is observed in the decay B0 --> K+ K-, and we set an upper limit of 3.7 x 10(-7) at 90% confidence level.

Journal Article↗

PubMed2005

Measurement of the wrong-sign decays D0 --> K+ pi- pi0 and D0 --> K+ pi- pi+ pi-, and search for CP violation.

Using 281 fb-1 of data from the Belle experiment recorded at or near the (4S) resonance, we have measured the rates of the "wrong-sign" decays D0 --> K+ pi- pi0 and D0 --> K+ pi- pi+ pi- relative to those of the Cabibbo-favored decays D0 --> K- pi+ pi0 and D0 --> K- pi+ pi+ pi-. These wrong-sign decays proceed via a doubly Cabibbo-suppressed amplitude or via D0-D0 mixing; the latter has not yet been observed. We obtain R(WS)(K pi pi0) = [0.229 +/- 0.015(stat)(+0.013)(-0.009)(syst)]% and R(WS)(K3pi) = [0.320 +/- 0.018(stat)(+0.018)(0.013)(syst)]%. The CP asymmetries are measured to be -0.006 +/- 0.053 and -0.018 +/- 0.044 for the K+ pi- pi0 and K+ pi- pi+ pi- final states, respectively.

Journal Article↗

PubMed2005

Improved evidence for direct CP violation in B0-->pi+pi- decays and model-independent constraints on phi2.

We present a new measurement of the time-dependent CP-violating parameters in B(0)--> pi(+)pi(-) decays with 275 x 10(6) BB pairs collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider operating at the Gamma(4S) resonance. We find 666 +/- 43 B(0) --> pi(+)pi(-) events and measure the CP-violating parameters: S(pipi) = -0.67 +/- 0.16(stat) +/- 0.06(syst) and A(pipi) = +0.56 +/- 0.12(stat) +/- 0.06(syst). We find evidence for large direct CP violation with a significance greater than 4 standard deviations for any S(pipi) value. Using isospin relations, we obtain 95.4% confidence intervals for the Cabibbo-Kobayashi-Maskawa quark-mixing matrix angle phi(2) of 0 degree < phiv(2) < 19 degrees and 71 degrees < phi(2) < 180 degrees.

Journal Article↗

PubMed2004

Evidence for direct CP violation in B0-->K+pi- decays.

We report evidence for direct CP violation in the decay B0-->K+pi(-) with 253 fb(-1) of data collected with the Belle detector at the KEKB e(+)e(-) collider. Using 275x10(6) BB pairs we observe a B-->K+/-pi(-/+) signal with 2140+/-53 events. The measured CP violating asymmetry is A(CP)(K+pi(-))=-0.101+/-0.025(stat)+/-0.005(syst), corresponding to a significance of 3.9sigma including systematics. We also search for CP violation in the decays B+-->K+pi(0) and B+-->pi(+)pi(0). The measured CP violating asymmetries are A(CP)(K+pi(0))=0.04+/-0.05(stat)+/-0.02(syst) and A(CP)(pi(+)pi(0))=-0.02+/-0.10(stat)+/-0.01(syst), corresponding to the intervals -0.05<A(CP)(K+pi(0))<0.13 and -0.18<A(CP)(pi(+)pi(0))<0.14 at 90% confidence level.

Journal Article↗

PubMed2001

[Maples at the sub-Alpine vegetation belt: a long history].

Pollen analysis was carried out on lacustrine sediment of a small hollow (15 m x 25 m) at the treeless sub-Alpine belt (202 m) of the inner Maurienne valley in the northern French Alps. A 2,500-year-long maple settlement was demonstrared. Three AMS dates of terrestrial plant macroremains support the chronology. First, Betula and Salix spread prior to 9,000 C14 BP. The first pollen grains of Acer, Abies and Pinus cembra are quoted at 8,600 C14 BP. High frequencies of Alnus glutinosa/incana (20%) and Acer (10%) show that mixed communities of Acer and Alnus persisted above the mountainous Abies forest between 7,490 and 5,850 C14 BP. After 5,850 C14 BP, the decrease in Acer stands could be attributed to fire as suggested by the strong increase in Betula and by the delayed expansion of Pinus cembra.

Altitude↗

PubMed2001

[Day-surgery operative hysteroscopy with loco-regional anesthesia].

BACKGROUND: Nowadays hysteroscopic surgery offers the opportunity of treating in Day Hospital even patients who cannot undergo a traditional surgery because of high anesthesiological risk. The aim of this study is to prove that minimal invasive hysteroscopic procedures in loco-regional anesthesia can replace laparotomic gynecological surgery in many intrauterine lesions with the same effectiveness on pain and outcome. METHODS: From September 1999 to December 2000 at the Obstetric and Gynecological Department in Asti 200 hysteroscopic procedures have been performed. The patients (all i.v. line inserted, ECG and pulsometer monitored, and sublingual BDZ sedated) were divided into two groups: a group of 50 patients who underwent operation on paracervical block alone, and the other one of 150 women on paracervical block plus periorificial infiltration of local anesthetic. RESULTS: Only one woman in the first group paracervical block was totally insufficient and she needed a general anesthesia. In the same group, 44% of paracervical blocks required an additional conscious sedation with Propofol and Fentanyl. In the second group only 16 % of cases required an additional sedation. In all cases outcome was very good with complete recovery of the patients dismissed the same afternoon. CONCLUSIONS: In our experience operative hysteroscopies under loco-regional anesthesia with paracervical block and periorificial infiltration is a very satisfactory alternative to general anesthesia. Moreover the type of intrauterine lesion did not influence the tolerability of the operation.

Adult↗

PubMed2000

Alkyl- and arylthiodediazoniations of dry arenediazonium o-benzenedisulfonimides. Efficient and safe modifications of the stadler and ziegler reactions to prepare alkyl aryl and diaryl sulfides

The reaction between dry arenediazonium o-benzenedisulfonimides 1 and sodium thiolates in anhydrous methanol represents an efficient and safe procedure, of general validity, for the preparation of unfunctionalized or variously functionalized alkyl aryl and diaryl sulfides. As a rule, the reaction temperature was maintained at 0-5 degrees C for the alkylthiodediazoniations and at room temperature (20-25 degrees C) for the arylthiodediazoniations. The sulfide yields are generally high; of the 63 considered examples, 43 gave yields greater than 80% and 13 were between 70% and 80%. Lower yields were obtained only when sterically hindered diazonium salts or thiols were used. A good amount of the o-benzenedisulfonimide (8) was always recovered from the reactions and could be reused to prepare salts 1. The copious experimental data collected in homogeneous conditions have offered several starting points for the study of the mechanism of these reactions.

Journal Article↗

PubMed1997

[Comparative study of diagnostic hysteroscopy and transvaginal ultrasonography in patients with abnormal uterine hemorrhage during the peri- and post-menopausal period].

BACKGROUND: The aim of this study was to determine the diagnostic value of hysteroscopy and transvaginal ultrasonography in patients with abnormal uterine bleeding (AUB) in the peri and postmenopausal period. METHODS: 302 patients with AUB, underwent hysteroscopy and in 86 cases, also a transvaginal ultrasonography before hysteroscopy was performed. Results were compared with the histological diagnosis. RESULTS: The diagnostic accuracy of hysteroscopy was very high in the cases of endometrial carcinoma (sensibility 100%, specificity 99%), and lower in the cases of endometrial hyperplasia (sensibility 69%, specificity 72%) and endometrial atrophy (sensibility 29% and specificity 97%). Sonography proved to be less reliable in the diagnosis of endometrial pathology (carcinoma: sensibility 57%, specificity 100%, hyperplasia: sensibility 62.5% specificity 63%). The results of this study show that sonography may be used as a first choice diagnostic test in the investigation of women with AUB. CONCLUSIONS: Hysteroscopy represent a second diagnostic step for achieving a proper histologic diagnosis.

Endometrial Hyperplasia↗

PubMed1995

[Terminology and classification problems in relation to vulvar pathology].

The aim of this paper is to update the physicians (gynecologists, dermatologists and pathologists) on the evolution of vulvar disease terminologies. In doing that the authors illustrate briefly the fundamental steps which led to present classifications of the International Society for the Study of Vulvar Disease (ISSVD). The classification of "non neoplastic epithelial disorders" together with that of "intraepithelial alterations" are illustrated and compared with the terminologies previously employed. The last ISSVD definition of "superficially invasive carcinoma" of the vulva is also presented and discussed. The authors concluded that even if all these ISSVD classifications represent an important effort for reaching a common language for a better international exchange of different experiences, nevertheless an improvement of these terminologies is still requested.

Female↗

PubMed1994

Membranous hypertrophy of the posterior fourchette as a cause of dyspareunia and vulvodynia.

Twenty-one women were treated surgically for entry dyspareunia and vulvodynia. The ages of the patients ranged from 18 to 39 years (mean, 24.5). Physical examination showed the presence of membranous hypertrophy of the posterior fourchette with consequent stricture of the vaginal introitus in all the patients. Eighty percent of the patients had erythema and tenderness of the vestibule, particularly in the posterior part. The histologic findings were somewhat enigmatic and quite unimpressive, frequently suggestive of chronic nonspecific inflammation; in only two cases were histologic changes suggestive of human papillomavirus infection observed. All the patients underwent excision of the posterior part of the vestibule with vaginal advancement under general anesthesia. Follow-up showed elimination of the symptoms in 19 patients and an improvement in the symptoms in the remaining 2.

Adolescent↗

PubMed1994

Psychological distress in women with nonneoplastic epithelial disorders of the vulva.

The aim of this study was to evaluate psychological distress in 44 women with vulvar squamous cell hyperplasia and 21 with vulvar lichen sclerosus in order to examine the presence of psychological factors in these dermatologic disorders. Two psychometric tests were used to evaluate depressive status and various aspects of anger. No significant depressive status was diagnosed with the former test either in patients with vulvar squamous cell hyperplasia or in patients with vulvar lichen sclerosus. Patients with squamous cell hyperplasia had two components of anger (state and internal anger) that were significantly higher and three components (trait anger, exteriorization and control of anger) significantly lower than did the controls. In patients with lichen sclerosus all the components of anger were within the normal range. These findings suggest that psychological factors may be associated with vulvar conditions, such as squamous cell hyperplasia, and may have some therapeutic implications in cases resistant to standard treatment.

Adult↗