363 research outputs found
Asymptotic Abelianness and Braided Tensor C*-Categories
By introducing the concepts of asymptopia and bi-asymptopia, we show how
braided tensor C*-categories arise in a natural way. This generalizes
constructions in algebraic quantum field theory by replacing local
commutativity by suitable forms of asymptotic Abelianness.Comment: 20 pages, no figures. Final version, as to appear in "Rigorous
Quantum Field Theory", Progress in Mathematics, Volume 25
Localization and symmetries
The violation of the Noether relation between symmetries and charges is
reduced to the time dependence of the charge associated to a conserved current.
For the U(1) gauge symmetry a non-perturbative control of the charge
commutators is obtained by an analysis of the Coulomb charged fields. From
this, in the unbroken case we obtain a correct expression for the electric
charge on the Coulomb states, its superselection and the presence of massless
vector bosons; in the broken case, we obtain a general non-perturbative version
of the Higgs phenomenon, i.e. the absence of massless Goldstone bosons and of
massless vector bosons. The conservation of the (gauge dependent) current
associated to the U(1) axial symmetry in QCD is shown to be compatible with the
time dependence of the corresponding charge commutators and a non-vanishing
eta' mass, as a consequence of the non locality of the (conserved) current.Comment: Invited contribution to ``The Quantum Universe'', dedicated to G.
Ghirardi for his 70th birthda
On Macroscopic Energy Gap for -Quantum Mechanical Systems
The q-deformed harmonic oscillator within the framework of the recently
introduced Schwenk-Wess -Heisenberg algebra is considered. It is shown, that
for "physical" values , the gap between the energy levels decreases
with growing energy. Comparing with the other (real) -deformations of the
harmonic oscillator, where the gap instead increases, indicates that the
formation of the macroscopic energy gap in the Schwenk-Wess -Quantum
Mechanics may be avoided.Comment: 6 pages, TeX, PRA-HEP-92/1
A prospective evaluation of persistence on antihypertensive treatment with different antihypertensive drugs in clinical practice
Persistence on treatment affects the efficacy of antihypertensive treatment. We prospectively investigated the persistence on therapy and the extent of blood pressure (BP) control in 347 hypertensive patients (age 59.4 +/- 6 years) randomly allocated to a first-line treatment with: angiotensin-converting enzyme (ACE) inhibitors, calcium-channel blockers (CCBs), beta-blockers, angiotensin-II receptor blockers (ARBs), or diuretics and followed-up for 24-months. Persistence on treatment was higher in patients treated with ARBs (68.5%) and ACE inhibitors (64.5%) vs CCBs (51.6%; p < 0.05), beta-blockers (44.8%, p < 0.05), and diuretics (34.4%, p < 0.01). No ARB, ACE inhibitor, beta-blocker, or diuretic was associated with a higher persistence in therapy compared with the other molecules used in each therapeutic class. The rate of persistence was significantly higher in patients treated with lercanidipine vs others CCBs (59.3% vs 46.6%, p < 0.05). Systolic and diastolic BP was decreased more successfully in patients treated with ARBs (-11.2/-5.8 mmHg), ACE inhibitors (-10.5/-5.1 mmHg), and CCBs (-8.5/-4.6 mmHg) compared with beta-blockers (-4.0/-2.3 mmHg p < 0.05) and diuretics (-2.3/-2.1 mmHg, p < 0.05). No ARB, ACE inhibitor, beta-blocker, or diuretic was associated with a higher BP control compared with the other molecules used in each therapeutic class. A trend toward a better BP control was observed in response to lercanidipine vs other CCBs (p = 0.059). The present results confirm the importance of persistence on treatment for the management of hypertension in clinical practice
Synthesis of novel structural hybrids between aza-heterocycles and azelaic acid moiety with a specific activity on osteosarcoma cells
Nine compounds bearing pyridinyl (or piperidinyl, benzimidazolyl, benzotriazolyl) groups bound to an azelayl moiety through an amide bond were synthesized. The structural analogy with some histone deacetylase inhibitors inspired their syntheses, seeking new selective histone deacetylase inhibitors (HDACi). The azelayl moiety recalls part of 9-hydroxystearic acid, a cellular lipid showing antiproliferative activity toward cancer cells with HDAC as a molecular target. Azelayl derivatives bound to a benzothiazolyl moiety further proved to be active as HDACi. The novel compounds were tested on a panel of both normal and tumor cell lines. Non-specific induction of cytotoxicity was observed in the normal cell line, while three of them induced a biological effect only on the osteosarcoma (U2OS) cell line. One of them induced a change in nuclear shape and size. Cell-cycle alterations are associated with post-transcriptional modification of both H2/H3 and H4 histones. In line with recent studies, revealing unexpected HDAC7 function in osteoclasts, molecular docking studies on the active molecules predicted their proneness to interact with HDAC7. By reducing side effects associated with the action of the first-generation inhibitors, the herein reported compounds, thus, sound promising as selective HDACi
Quantum delocalization of the electric charge
The classical Maxwell-Dirac and Maxwell-Klein-Gordon theories admit solutions
of the field equations where the corresponding electric current vanishes in the
causal complement of some bounded region of Minkowski space. This poses the
interesting question of whether states with a similarly well localized charge
density also exist in quantum electrodynamics. For a large family of charged
states, the dominant quantum corrections at spacelike infinity to the
expectation values of local observables are computed. It turns out that certain
moments of the charge density decrease no faster than the Coulomb field in
spacelike directions. In contrast to the classical theory, it is therefore
impossible to define the electric charge support of these states in a
meaningful way.Comment: 17 page
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