43 research outputs found
Quark contribution to the reggeon-reggeon-gluon vertex in QCD
The quark loop contribution to the reggeon-reggeon-gluon vertex is calculated
in QCD, where the reggeon is the reggeized gluon. Compared with the vertex in
the Born approximation, this contribution exhibits a new spin structure as well
as the gluon loop one. A remarkable but not complete cancellation between gluon
and quark contributions to this new spin structure takes place for the case of
three massless quark flavours.Comment: 19 pages + 2 figures(appended as a postscript file), Late
La progettazione psicosociale nei progetti del Sistema di Accoglienza e Integrazione/SAIUn modello di intervento
The authors, psychologists, social workers, educators, care workers of the "Don Vincenzo Matrangolo" Association, aware that in the field of Reception and Inte-gration there is no shared methodology to define in detail the process of psychosocial planning, present the validation of an accurate and meticulous proposal in which they define the "phases, tools and timing" of a professional work that faces the complex emergency of migration
Effect of primary care physicians' use of estimated glomerular filtration rate on the timing of their subspecialty referral decisions
<p>Abstract</p> <p>Background</p> <p>Primary care providers' suboptimal recognition of the severity of chronic kidney disease (CKD) may contribute to untimely referrals of patients with CKD to subspecialty care. It is unknown whether U.S. primary care physicians' use of estimated glomerular filtration rate (eGFR) rather than serum creatinine to estimate CKD severity could improve the timeliness of their subspecialty referral decisions.</p> <p>Methods</p> <p>We conducted a cross-sectional study of 154 United States primary care physicians to assess the effect of use of eGFR (versus creatinine) on the timing of their subspecialty referrals. Primary care physicians completed a questionnaire featuring questions regarding a hypothetical White or African American patient with progressing CKD. We asked primary care physicians to identify the serum creatinine and eGFR levels at which they would recommend patients like the hypothetical patient be referred for subspecialty evaluation. We assessed significant improvement in the timing [from eGFR < 30 to ≥ 30 mL/min/1.73m<sup>2</sup>) of their recommended referrals based on their use of creatinine versus eGFR.</p> <p>Results</p> <p>Primary care physicians recommended subspecialty referrals later (CKD more advanced) when using creatinine versus eGFR to assess kidney function [median eGFR 32 versus 55 mL/min/1.73m<sup>2</sup>, p < 0.001]. Forty percent of primary care physicians significantly improved the timing of their referrals when basing their recommendations on eGFR. Improved timing occurred more frequently among primary care physicians practicing in academic (versus non-academic) practices or presented with White (versus African American) hypothetical patients [adjusted percentage(95% CI): 70% (45-87) versus 37% (reference) and 57% (39-73) versus 25% (reference), respectively, both p ≤ 0.01).</p> <p>Conclusions</p> <p>Primary care physicians recommended subspecialty referrals earlier when using eGFR (versus creatinine) to assess kidney function. Enhanced use of eGFR by primary care physicians' could lead to more timely subspecialty care and improved clinical outcomes for patients with CKD.</p
Reggeization of quark-quark scattering amplitude in QCD
s-channel discontinuity of quark-quark scattering amplitude with gluon quantum numbers in the t channel and negative signature is calculated in the Regge kinematical region in the two-loop approximation. Using this discontinuity and assuming that the Regge asymptotic behaviour is given by the Reggeized gluon contribution, we calculate the gluon trajectory in the two-loop approximation. Remarkable cancellations lead to the independence of the trajectory on properties of the scattered quarks, confirming the gluon Reggeization
Absorption Spectra of the Potential Photodynamic Therapy Photosensitizers Texaphyrins Complexes: A Theoretical Analysis
A systematic study of a class of divalent transition-metal texaphyrin complexes (M-Tex+, M = Mn, Fe, Co, Ni, Cu, Zn), recently proposed as active photosensitizers in photodynamic therapy (PDT), was undertaken for the ground and excited electronic states. Geometry optimizations were performed by using the PBE0 exchange-correlation functional coupled with the 6-31G(d) basis set, while electronic excitations energies were evaluated by means of time-dependent density functional response theory (TD-DFT) at the PBE0/6-31+G(d) // PBE0/6-31G(d) level of theory. Solvent effects on excitation energies were taken into account in two ways:  by considering solvent molecules explicitly coordinated to the metal center and as bulk effects, within the conductor-like polarizable continuum model (C-PCM). The influence of the metal cation on the so-called Q-band, localized in the near-red visible region of the spectrum, was carefully examined since it plays a basic role in the drug design of new photodynamic therapy photosensitizers. The differences between experimental and computed excitation energies were found to be within 0.3 eV