112 research outputs found
Analytic Approximations for Three Neutrino Oscillation Parameters and Probabilities in Matter
The corrections to neutrino mixing parameters in the presence of matter of
constant density are calculated systematically as series expansions in terms of
the mass hierarchy \dm{21}/\dm{31}. The parameter mapping obtained is then
used to find simple, but nevertheless accurate formulas for oscillation
probabibilities in matter including CP-effects. Expressions with one to one
correspondence to the vacuum case are derived, which are valid for neutrino
energies above the solar resonance energy. Two applications are given to show
that these results are a useful and powerful tool for analytical studies of
neutrino beams passing through the Earth mantle or core: First, the
``disentanglement problem'' of matter and CP-effects in the CP-asymmetry is
discussed and second, estimations of the statistical sensitivity to the
CP-terms of the oscillation probabilities in neutrino factory experiments are
presented.Comment: 17 pages, 3 figure
Atypical suamous papilloma of the conjunctiva
Papillomas are benign tumors of human skin and mucous membranes caused by human papillomavirus (HPV). The virus causes abnormal epithelial cell growth. The formations vary in shape, size and location. The conjunctival papillomas are one of the most common benign tumors of the squamous epithelium of the conjunctiva. They rarely undergo malignant transformation. Purpose: To present a clinical case with proven atypical squamous papilloma of the conjunctiva. Materials: 58-year-old patient was admitted to the Eye Clinic of University Alexandrovska hospital for the first time. Methods: A complete ophthalmologic examination, ultrasonography, surgery and pathohistological diagnosis were performed. Results: Thorough excision of the tumor lesion in healthy tissue was performed. The pathological diagnosis revealed atypical squamous papilloma of the conjunctiva. Conclusion: The diagnosis can only be confirmed pathohistologically. A good relationship between ophthalmologist and pathologist is necessary for the successful diagnosis and subsequent treatment
Limiting the resectability in locally advanced primary or rec urrent carcinoma of the colon
Purpose: The terms of ‘unresectable`, ‘inoperable` and ‘incurable` cancer/patient are widely used but not clearly defined and thus subject to significant subjectivity. Where is the limit of ‘resectability` of colorectal cancer - the criteria are variable and not precisely defined yet. Locally advanced lesion may vary from visible intimately adhered to the surrounding tissue, i.e. marginal, ‘border` resectable tumour to one that directly macroscopically engages adjacent critical structures. This paper presents the experience of other foreign authors with their results in the determination of the tumour as resectable or unresectable as well as own clinical experience in this field.Material and methods: The study covered the patients with colorectal cancer who were operated in the Clinic of Surgery during a period of 9 years and retrospectively analyzed.Results: Out of a total of 1051 surgeries on the occasion of colorectal cancer, advanced disease constituted 28,6% or 301 patients. Of them, 52,5% were localized in different parts of the colon. Fifty-eight combined resections were performed as in 7 of them (recurrent tumours) R1 was accomplished, i.e. a non-radical result. A total of 117 cases were assessed intraoperatively as non-radical surgery and palliative procedures were performed such as resections (with or without restoration of the intestinal passage, but in the case of M1), bypass anastomoses, or simple interruption of the passage. .Conclusion: Many of the world`s leading surgical centres adopt the tactics of ‘adequate aggressive behaviour` for locally advanced primary and recurrent colorectal cancer. In determining the reasonable balance between aggressive approach and the so-called meaningless ‘surgical exorbitance` there is strive to adhere to the view that failure to achieve R0-resection planed in such an operation as well as leading performance or a combination of factors such as advanced age, severe co-morbidities, presence of complicated forms of colorectal cancer, urgent intervention and data of generalization of the malignant process undermine the performance of aggressive block removal of tumour formation. However, adequate pre- and intraoperative assessment and surgical experience should avoid ‘exaggerated` intraoperative status of locally advanced tumou
Normal tension glaucoma – case report
Normal tension glaucoma (NTG), reffered to also as low-tension glaucoma, represents a glaucomatous optic neuropathy classified as a type of Primary open angle glaucoma (POAG). It is characterized by a higher tendency of damage to the optic nerve at relatively low levels of intraocular pressure (IOP), as well as asymmetric pathological process in both eyes of the same patient. A number of IOP-independent factors play a significant role in the progression of the disease and often lead to difficulties in diagnosis and optimal therapy in these patients. We report a typical clinical case of a patient with NTG
Capillary pressure of van der Waals liquid nanodrops
The dependence of the surface tension on a nanodrop radius is important for
the new-phase formation process. It is demonstrated that the famous Tolman
formula is not unique and the size-dependence of the surface tension can
distinct for different systems. The analysis is based on a relationship between
the surface tension and disjoining pressure in nanodrops. It is shown that the
van der Waals interactions do not affect the new-phase formation thermodynamics
since the effect of the disjoining pressure and size-dependent component of the
surface tension cancel each other.Comment: The paper is dedicated to the 80th anniversary of A.I. Rusano
Magnus Expansion and Three-Neutrino Oscillations in Matter
We present a semi-analytical derivation of the survival probability of solar
neutrinos in the three generation scheme, based on the Magnus approximation of
the evolution operator of a three level system, and assuming a mass hierarchy
among neutrino mass eigenstates. We have used an exponential profile for the
solar electron density in our approximation. The different interesting density
regions that appear throughout the propagation are analyzed. Finally, some
comments on the allowed regions in the solar neutrino parameter space are
addressed.Comment: RevTex4 style, 5 pages including 5 figures. Presented at Mexican
School of Astrophysics 2002, Guanajuato, Mexico, 31 Jul - 7 Aug 2002. Final
version to appear in the Proceedings of IX Mexican Workshop on Particles and
Fields Physics Beyond the Standard Model, Colima Col. Mexico, November 17-22,
200
CP and T violation test in neutrino oscillation
We examine how large violation of CP and T is allowed in long base line
neutrino experiments. When we attribute only the atmospheric neutrino anomaly
to neutrino oscillation we may have large CP violation effect. When we
attribute both the atmospheric neutrino anomaly and the solar neutrino deficit
to neutrino oscillation we may have a sizable T violation effect proportional
to the ratio of two mass differences; it is difficult to see CP violation since
we can't ignore the matter effect. We give a simple expression for T violation
in the presence of matter.Comment: 12 pages + 2 eps figures, Latex, In order to avoid misunderstanding
we have refined our English and rewritten the parts which might be
misleading. Several typographical errors are correcte
CP Violation and Matter Effect in Long Baseline Neutrino Oscillation Experiments
We show simple methods how to separate pure CP violating effect from matter
effect in long baseline neutrino oscillation experiments with three generations
of neutrinos. We give compact formulae for neutrino oscillation probabilities
assuming one of the three neutrino masses (presumably tau-neutrino mass) to be
much larger than the other masses and the effective mass due to matter effect.
Two methods are shown: One is to observe envelopes of the curves of oscillation
probabilities as functions of neutrino energy; a merit of this method is that
only a single detector is enough to determine the presence of CP violation. The
other is to compare experiments with at least two different baseline lengths;
this has a merit that it needs only narrow energy range of oscillation data.Comment: 17 pages + 9 eps figures, LaTeX, errors are correcte
- …