519 research outputs found
Fixed twist dynamics of SO(3) gauge theory
We perform a throughout study of 3+1 dim. SO(3) LGT for any fixed-twist
background. We concentrate in particular on the physically significant trivial
and 1-twist sectors. Introducing a Z(2) monopole chemical potential the 1st
order bulk transition is moved down in the strong coupling region and weakened
to 2nd order in the 4-dim Ising model universality class. In this extended
phase diagram we gain access to a confined phase in every fixed twist sector of
the theory. The Pisa disorder operator is employed together with the Polyakov
loop to study the confinement-deconfinement transition in each sector. Due to
the specific properties of both operators, most results can be used to gain
insight in the ergodic theory, where all twist sectors should be summed upon.
An explicit mapping of each fixed twist theory to effective positive plaquette
models with fixed twisted boundary conditions is applied to better establish
their properties in the different phases.Comment: 20 pages, 11 Figures. Minor changes in text and figures, to appear in
Eur.Phys.J.
Spray freeze-drying as a solution to continuous manufacturing of pharmaceutical products in bulk
Pharmaceutical manufacturing is evolving from traditional batch processes to continuous ones. The new global competition focused on throughput and quality of drug products is certainly the driving force behind this transition which, thus, represents the new challenge of pharmaceutical manufacturing and hence of lyophilization as a downstream operation. In this direction, the present review deals with the most recent technologies, based on spray freeze-drying, that can achieve this objective. It provides a comprehensive overview of the physics behind this process and of the most recent equipment design
Effect of mixing in the preparation of doxorubicin-loaded cyanoacrylate nanoparticles via solvent displacement
Universality, vortices and confinement: modified SO(3) lattice gauge theory at non-zero temperature
We investigate the adjoint SU(2) lattice gauge theory in 3+1 dimensions with
the Wilson plaquette action modified by a Z(2) monopole suppression term. For
the zero-twist sector we report indications for the existence of a finite
temperature effect decoupled from the unphysical bulk transitions.Comment: 17 pages, 10 figures. Some figures and text added. To appear on Phys.
Rev.
SO(3) versus SU(2) lattice gauge theory
We consider the SO(3) lattice gauge theory at weak coupling, in the Villain
action. We exhibit an analytic path in coupling space showing the equivalence
of the SO(3) theory with SU(2) summed over all twist sectors. This clarifies
the ``mysterious phase'' of SO(3). As order parameter, we consider the dual
string tension or center vortex free energy, which we measure in SO(3) using
multicanonical Monte Carlo. This allows us to set the scale, indicating that
lattices are necessary to probe the confined phase. We
consider the relevance of our findings for confinement in other gauge groups
with trivial center.Comment: 12 pages, 6 figures, to appear in the Proceedings of the NATO
workshop on "Confinement, Topology, and other Non-Perturbative Aspects of
QCD", Stara Lesna, Feb. 200
Catalytic abatement of fugitive gaseous pollutants from iron-making processes (ENV4-CT97-0599)
A water-filled garment to protect astronauts during interplanetary missions tested on board the ISS
Abstract As manned spaceflights beyond low Earth orbit are in the agenda of Space Agencies, the concerns related to space radiation exposure of the crew are still without conclusive solutions. The risk of long-term detrimental health effects needs to be kept below acceptable limits, and emergency countermeasures must be planned to avoid the short-term consequences of exposure to high particle fluxes during hardly predictable solar events. Space habitat shielding cannot be the ultimate solution: the increasing complexity of future missions will require astronauts to protect themselves in low-shielded areas, e.g. during emergency operations. Personal radiation shielding is promising, particularly if using available resources for multi-functional shielding devices. In this work we report on all steps from the conception, design, manufacturing, to the final test on board the International Space Station (ISS) of the first prototype of a water-filled garment for emergency radiation shielding against solar particle events. The garment has a good shielding potential and comfort level. On-board water is used for filling and then recycled without waste. The successful outcome of this experiment represents an important breakthrough in space radiation shielding, opening to the development of similarly conceived devices and their use in interplanetary missions as the one to Mars
Is It Rational to Assume that Infants Imitate Rationally? A Theoretical Analysis and Critique
It has been suggested that preverbal infants evaluate the efficiency of others' actions (by applying a principle of rational action) and that they imitate others' actions rationally. The present contribution presents a conceptual analysis of the claim that preverbal infants imitate rationally. It shows that this ability rests on at least three assumptions: that infants are able to perceive others' action capabilities, that infants reason about and conceptually represent their own bodies, and that infants are able to think counterfactually. It is argued that none of these three abilities is in place during infancy. Furthermore, it is shown that the idea of a principle of rational action suffers from two fallacies. As a consequence, is it suggested that it is not rational to assume that infants imitate rationally. Copyright (C) 2012 S. Karger AG, Base
Adhesions due to peritoneal carcinomatosis caused by a renal carcinoma leading to mechanical gastric outlet obstruction: a case report
<p>Abstract</p> <p>Introduction</p> <p>Gastric outlet obstruction is a clinical syndrome caused by a variety of mechanical obstructions. Peptic ulcer disease used to be responsible for most gastric outlet obstruction, but in the last 40 years the prevalence of malignant tumors has risen significantly. Adhesive disease is an infrequent and insidious cause of mechanical gastric outlet obstruction.</p> <p>Case presentation</p> <p>We report the case of a 78-year-old Caucasian man who had a clinical history of a right nephrectomy for malignancy three years earlier and who was admitted for a severe gastric outlet obstruction (score of 1) confirmed both by an upper endoscopy and by a fluoroscopic view after contrast injection. A computed tomography scan and a laparotomy, with omental biopsies, showed a peritoneal carcinomatosis with the development of abdominal adhesions that prompted an abnormal gastric rotation around the perpendicular axis of his antrum with a dislocation in the empty space of his right kidney. Symptoms disappeared after surgical bypass through a gastrojejunostomy.</p> <p>Conclusions</p> <p>Our patient experienced a very rare complication characterized by the development of adhesions due to peritoneal carcinomatosis caused by a renal carcinoma treated with nephrectomy. These adhesions prompted an abnormal dislocation of his antrum, as an internal hernia, in the empty space of his right kidney.</p
Retinal vascular impairment in Wolfram syndrome: an optical coherence tomography angiography study
To evaluate differences in macular and optic disc circulation in patients affected by Wolfram Syndrome (WS) employing optical coherence tomography-angiography (OCTA) imaging. In this retrospective study, 18 eyes from 10 WS patients, 16 eyes of 8 patients affected by type I diabetes and 17 eyes from 17 healthy controls were enrolled. All patients were imaged through OCT and OCTA and vascular parameters, as perfusion density (PD) and vessel length density (VLD) were measured. OCTA showed reduced PD in WS patients at the macular superficial capillary plexus (SCP, 27.8 ± 5.3%), deep vascular complex (DVC, 33.2 ± 1.9%) and optic nerve head (ONH, 21.2 ± 9.1%) compared to both diabetic patients (SCP 33.9 ± 1.9%, P < 0.0001; DVC 33.2 ± 0.7%, P = 1.0; ONH 33.9 ± 1.3, P < 0.0001) and healthy controls (SCP 31.6 ± 2.5, P = 0.002; DVC 34.0 ± 0.7%, P = 0.089; ONH 34.6 ± 0.8%, P < 0.0001). Similarly, VLD was lower in WS patients at the SCP (10.9 ± 2.7%) and ONH levels (7.5 ± 4.1%) compared to diabetic patients (SCP 13.8 ± 1.2%, P = 0.001; DVC 13.8 ± 0.2%, P < 0.0001; ONH 13.0 ± 0.7%, P = < 0.0001), but higher in DVC (15.7 ± 1.2%, P < 0.0001). Furthermore, VLD was lower in WS patients in all the vascular parameters compared to controls (SCP 13.8 ± 1.5%, P < 0.0001; DVC 17.3 ± 0.6%, P < 0.0001; ONH 15.7 ± 0.5%, P < 0.0001). A significant microvasculature impairment in the macular SCP and ONH microvasculature was demonstrated in eyes affected by WS. Microvascular impairment may be considered a fundamental component of the neurodegenerative changes in WS
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