18 research outputs found
Tratamiento quirúrgico vs terapia periodontal básica: estudios longitudinales en periodoncia clínica
Las enfermedades periodontales son unas graves infecciones bacterianas que destruyen las fibras de inserción y el hueso de soporte que mantienen los dientes en la boca. Sin tratar, esta enfermedad puede llevar a la pérdida dental (Medical Dictionary). Los estudios longitudinales han centrado su atención hacia la periodontitis crónica. Se ha documentado el decisivo papel de la placa bacteriana en la iniciación y en el mantenimiento de la gingivitis, y que, los efectos dañinos sobre los tejidos y la gravedad de estos efectos están regulados por una compleja interacción entre el parásito y huésped. El tratamiento de la lesión periodontal cumple, para el tratamiento periodontal básico, con el propósito de eliminar y prevenir la recurrencia de los depósitos bacterianos localizados en las superficies dentarias supragingivales y subgingivales y, para el tratamiento quirúrgico con el objetivo de crear acceso para el desbridamiento profesional correcto de las superficies radiculares infectadas y establecer una morfología gingival adecuada que facilite el autocontrol de la placa por parte del paciente. Diferentes técnicas se han utilizado para alcanzar el objetivo de mejorar el pronóstico de los dientes a largo plazo. Desafortunadamente no son muchos los estudios que consiguen demostrar la efectividad de las técnicas utilizadas, con una evolución a lo largo del tiempo dejando entonces algunas incertidumbres. Periodontal diseases are bacterial infections that destroy the attachment fibres and supporting bone that hold the teeth in the mouth. Left untreated, these diseases can lead to tooth loss (Medical Dictionary). Longitudinal studies centred their attention on chronic periodontitis. It has been documented the decisive role played by microbiological plaque in the initiation of gingivitis and that, the harmful effect on the tissues and its severity, are controlled by the complex host-parasite interaction. Treatment of periodontal lesion can be carried out either by non-surgical treatment, to eliminate and prevent the recurrence of bacterial deposits, or by surgical treatment, to create access for professional debridment of infected root surface and establish adequate gingival morphology to facilitate self plaque control. Different techniques are used to achieve the objective to improve teeth long term prognosis. Unfortunately no many studies have been able to demonstrate the effectiveness of the used technique in a long term intervals leaving unclear some questions
Actualización en radiología dental: Radiología convencional Vs digital
Desde su incorporación a la práctica odontológica la radiología digital ha experimentado un importante desarrollo. El continuo avance de las tecnologías en las que se sustenta ha dotado a estos sistemas de interesantes prestaciones que pueden facilitar el diagnóstico y manejo de imágenes radiográficas. Con estos avances la radiología digital ha despertado un interés creciente entre los profesionales de la odontología, especialmente durante los últimos años, en los que ha aumentado notoriamente tanto la cantidad de sistemas comercializados como el número de odontólogos que han decidido sustituir la radiología convencional por un sistema digital en sus clínicas. En esta revisión de la literatura se tratará de ofrecer una visión actualizada de los distintos sistemas disponibles en la actualidad, así como una comparativa entre ellos basada en estudios publicados recientemente. Since its appearance in dentistry, digital radiology has experienced a notorious development. A constant advance in the corresponding technologies has enhanced these digital systems with interesting features which may facilitate radiological diagnosis and image management. Due to these advances digital radiology has elicited a growing interest in dentistry. Specially during the last years there has been an increase both in the amount of available systems and in the number of dentists who have incorporated a digital system in their offices. This literature review aims to offer an updated view of the available systems and a comparison of them based in recent studies
Hadronic Annihilation Decay Rates of P-wave Heavy Quarkonia with Both Relativistic and QCD Radiative Corrections
Hadronic annihilation decay rates of P-wave heavy quarkonia are given to
next-to-leading order in both and . They include ten
nonperturbative parameters, which can be rigorously defined as the matrix
elements of color-singlet and color-octet operators in NRQCD. We expect these
papameters will be determined from lattice calculations in future.Comment: 5 Pages RevTex. The paper is withdraw
Calculation of P-Wave Charmonium Decay Rates Using Dimensional Regularization
Contributions to the decay rates of P-wave charmonium states that are
proportional to , where is the number of flavors of light
quarks, are calculated in the framework of nonrelativistic QCD using the
threshold expansion method. Dimensional regularization is used to regularize
the infrared divergences that arise from the emission of a soft gluon. Our
results are consistent with the original calculations of Barbieri et al.Comment: 29 pages, LaTex, 5 fige
Colour-Octet Effects in Radiative Decays
We investigate the effects of colour-octet contributions to the radiative
decay within the Bodwin, Braaten and Lepage NRQCD factorization
framework. Photons coming both from the coupling to hard processes (`direct')
and by collinear emission from light quarks (`fragmentation') are consistently
included at next-to-leading order (NLO) in . An estimate for the
non-perturbative matrix elements which enter in the final result is then
obtained. By comparing the NRQCD prediction at NLO for total decay rates with
the experimental data, it is found that the non-perturbative parameters must be
smaller than expected from the na\"\i ve scaling rules of NRQCD. Nevertheless,
colour-octet contributions to the shape of the photon spectrum turn out to be
significant.Comment: 25 pages, Latex, 8 figure
QCD corrections to plus -boson production at the LHC
The associated production at the LHC is an important process in
investigating the color-octet mechanism of non-relativistic QCD in describing
the processes involving heavy quarkonium. We calculate the next-to-leading
order (NLO) QCD corrections to the associated production at the
LHC within the factorization formalism of nonrelativistic QCD, and provide the
theoretical predictions for the distribution of the transverse
momentum. Our results show that the differential cross section at the
leading-order is significantly enhanced by the NLO QCD corrections. We conclude
that the LHC has the potential to verify the color-octet mechanism by measuring
the production events.Comment: 14 page revtex, 5 eps figures, to appear in JHEP. fig5 and the
corresponding analysis are correcte
Heavy quarkonium: progress, puzzles, and opportunities
A golden age for heavy quarkonium physics dawned a decade ago, initiated by
the confluence of exciting advances in quantum chromodynamics (QCD) and an
explosion of related experimental activity. The early years of this period were
chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in
2004, which presented a comprehensive review of the status of the field at that
time and provided specific recommendations for further progress. However, the
broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles
could only be partially anticipated. Since the release of the YR, the BESII
program concluded only to give birth to BESIII; the -factories and CLEO-c
flourished; quarkonium production and polarization measurements at HERA and the
Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the
deconfinement regime. All these experiments leave legacies of quality,
precision, and unsolved mysteries for quarkonium physics, and therefore beg for
continuing investigations. The plethora of newly-found quarkonium-like states
unleashed a flood of theoretical investigations into new forms of matter such
as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the
spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b},
and b\bar{c} bound states have been shown to validate some theoretical
approaches to QCD and highlight lack of quantitative success for others. The
intriguing details of quarkonium suppression in heavy-ion collisions that have
emerged from RHIC have elevated the importance of separating hot- and
cold-nuclear-matter effects in quark-gluon plasma studies. This review
systematically addresses all these matters and concludes by prioritizing
directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K.
Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D.
Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A.
Petrov, P. Robbe, A. Vair
Baseline BMI and BMI variation during first line pembrolizumab in NSCLC patients with a PD-L1 expression >= 50%: a multicenter study with external validation
Background The association between obesity and
outcomes in patients receiving programmed death-1/
programmed death ligand-1 (PD-L1) checkpoint inhibitors
has already been confirmed in pre-treated non-small cell
lung cancer (NSCLC) patients, regardless of PD-L1 tumor
expression.
Methods We present the outcomes analysis according
to baseline body mass index (BMI) and BMI variation in a
large cohort of metastatic NSCLC patients with a PD-L1
expression ≥50%, receiving first line pembrolizumab.
We also evaluated a control cohort of metastatic
NSCLC patients treated with first line platinum-based
chemotherapy. Normal weight was set as control group.
Results 962 patients and 426 patients were included
in the pembrolizumab and chemotherapy cohorts,
respectively. Obese patients had a significantly higher
objective response rate (ORR) (OR=1.61 (95% CI: 1.04–
2.50)) in the pembrolizumab cohort, while overweight
patients had a significantly lower ORR (OR=0.59 (95%
CI: 0.37–0.92)) within the chemotherapy cohort. Obese
patients had a significantly longer progression-free
survival (PFS) (HR=0.61 (95% CI: 0.45–0.82)) in the
pembrolizumab cohort. Conversely, they had a significantly
shorter PFS in the chemotherapy cohort (HR=1.27 (95%
CI: 1.01–1.60)). Obese patients had a significantly longer
overall survival (OS) within the pembrolizumab cohort
(HR=0.70 (95% CI: 0.49–0.99)), while no significant
differences according to baseline BMI were found in the
chemotherapy cohort. BMI variation significantly affected
ORR, PFS and OS in both the pembrolizumab and the
chemotherapy cohorts.
Conclusions Baseline obesity is associated to
significantly improved ORR, PFS and OS in metastatic
NSCLC patients with a PD-L1 expression of ≥50%,
receiving first line pembrolizumab, but not among
patients treated with chemotherapy. BMI variation is also
significantly related to clinical outcomes
Acute Delta Hepatitis in Italy spanning three decades (1991–2019): Evidence for the effectiveness of the hepatitis B vaccination campaign
Updated incidence data of acute Delta virus hepatitis (HDV) are lacking worldwide. Our aim was to evaluate incidence of and risk factors for acute HDV in Italy after the introduction of the compulsory vaccination against hepatitis B virus (HBV) in 1991. Data were obtained from the National Surveillance System of acute viral hepatitis (SEIEVA). Independent predictors of HDV were assessed by logistic-regression analysis. The incidence of acute HDV per 1-million population declined from 3.2 cases in 1987 to 0.04 in 2019, parallel to that of acute HBV per 100,000 from 10.0 to 0.39 cases during the same period. The median age of cases increased from 27 years in the decade 1991-1999 to 44 years in the decade 2010-2019 (p < .001). Over the same period, the male/female ratio decreased from 3.8 to 2.1, the proportion of coinfections increased from 55% to 75% (p = .003) and that of HBsAg positive acute hepatitis tested for by IgM anti-HDV linearly decreased from 50.1% to 34.1% (p < .001). People born abroad accounted for 24.6% of cases in 2004-2010 and 32.1% in 2011-2019. In the period 2010-2019, risky sexual behaviour (O.R. 4.2; 95%CI: 1.4-12.8) was the sole independent predictor of acute HDV; conversely intravenous drug use was no longer associated (O.R. 1.25; 95%CI: 0.15-10.22) with this. In conclusion, HBV vaccination was an effective measure to control acute HDV. Intravenous drug use is no longer an efficient mode of HDV spread. Testing for IgM-anti HDV is a grey area requiring alert. Acute HDV in foreigners should be monitored in the years to come