879 research outputs found
Sex assignment in conditions affecting sex development
The newborn infant with atypical genitalia presents a challenging clinical scenario and requires expert input. There have been appreciable advances in our knowledge of the underlying causes that may lead to a mere difference or a more serious disorder of sex development (DSD), the natural history of conditions, as well as the short and long-term complications of these conditions themselves, together with the clinical interventions that are associated with these conditions. With this information, the DSD expert can be more confident when discussing options with the parents of the newborn infant. By working within a multidisciplinary team, the expert should be able to support the family whilst individualising the management plan so that it is also cognizant of the shifts in societal attitudes and expectations around concepts of diversity and openness. It is, therefore, likely that the practice of assigning sex, especially in those cases where sex assignment is unclear on expert assessment, will continue to show temporal, social and geographical variations. It is imperative that clinical data for rare conditions such as these are collected in a standardized format and shared through a common registry so that any evidence that is used for future shifts in practice has a stronger foundation than that which is currently available
High order fluid model for streamer discharges. II. Numerical solution and investigation of planar fronts
The high order fluid model developed in the preceding paper is employed here
to study the propagation of negative planar streamer fronts in pure nitrogen.
The model consists of the balance equations for electron density, average
electron velocity, average electron energy and average electron energy flux.
These balance equations have been obtained as velocity moments of Boltzmann's
equation and are here coupled to the Poisson equation for the space charge
electric field. Here the results of simulations with the high order model, with
a PIC/MC (Particle in cell/Monte Carlo) model and with the first order fluid
model based on the hydrodynamic drift-diffusion approximation are presented and
compared. The comparison with the MC model clearly validates our high order
fluid model, thus supporting its correct theoretical derivation and numerical
implementation. The results of the first order fluid model with local field
approximation, as usually used for streamer discharges, show considerable
deviations. Furthermore, we study the inaccuracies of simulation results caused
by an inconsistent implementation of transport data into our high order fluid
model. We also demonstrate the importance of the energy flux term in the high
order model by comparing with results where this term is neglected. Finally,
results with an approximation for the high order tensor in the energy flux
equation is found to agree well with the PIC/MC results for reduced electric
fields up to 1000 Townsend, as considered in this work.Comment: 26 pages, 11 figure
Derivation and test of high order fluid model for streamer discharges
A high order fluid model for streamer dynamics
is developed by closing the system after the 4th moment
of the Boltzmann equation in local mean energy approximation.
This is done by approximating the high order
pressure tensor in the heat flux equation through the previous
moments. Mathematical characteristics of the system is
studied. Then planar ionization fronts for negative streamers
in Nsub2 are simulated with the classical streamer model,
MC-PIC particle model, and with the present higher order
model
Testicular dermoid cyst in a 14-year-old child
ΠΠΠ ΠΠΠΠΠΠΠ― ΠΠΠ‘Π’Π /ΠΠΠΠΠΠΠΠ ΠΠΠΠ /ΠΠΠΠΠΠ―ΠΠ§ΠΠ /Π£ΠΠ¬Π’Π ΠΠ‘ΠΠΠΠΠ’ΠΠΠΠΠΠΠ§ΠΠ‘ΠΠΠ Π‘ΠΠ£Π§ΠΠΠ ΡΠ°Π±ΠΎΡΠ΅ ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½ ΠΊΠ»ΠΈΠ½ΠΈΡΠ΅ΡΠΊΠΈΠΉ ΡΠ»ΡΡΠ°ΠΉ ΡΠ΅Π±Π΅Π½ΠΊΠ°, 14 Π»Π΅Ρ, Ρ Π΄Π΅ΡΠΌΠΎΠΈΠ΄Π½ΠΎΠΉ ΠΊΠΈΡΡΠΎΠΉ ΠΏΡΠ°Π²ΠΎΠ³ΠΎ ΡΠΈΡΠΊΠ°. ΠΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΠ΅ Π²ΠΏΠ΅ΡΠ²ΡΠ΅ Π±ΡΠ»ΠΎ Π²ΡΡΠ²Π»Π΅Π½ΠΎ ΠΏΡΠΈ ΠΏΡΠΎΡΠΈΠ»Π°ΠΊΡΠΈΡΠ΅ΡΠΊΠΎΠΌ ΠΎΡΠΌΠΎΡΡΠ΅ Π² ΠΏΠΎΠ»ΠΈΠΊΠ»ΠΈΠ½ΠΈΠΊΠ΅. Π ΠΏΠΎΡΠ»Π΅Π΄ΡΡΡΠ΅ΠΌ ΠΏΠ°ΡΠΈΠ΅Π½ΡΡ Π½Π΅ΠΎΠ΄Π½ΠΎΠΊΡΠ°ΡΠ½ΠΎ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠ»ΠΎΡΡ ΡΠ»ΡΡΡΠ°Π·Π²ΡΠΊΠΎΠ²ΠΎΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ Π½Π°ΡΡΠΆΠ½ΡΡ
ΠΏΠΎΠ»ΠΎΠ²ΡΡ
ΠΎΡΠ³Π°Π½ΠΎΠ², ΠΏΡΠΈ ΠΊΠΎΡΠΎΡΠΎΠΌ Π² Π²Π΅ΡΡ
Π½Π΅ΠΌ ΠΏΠΎΠ»ΡΡΠ΅ ΠΏΡΠ°Π²ΠΎΠ³ΠΎ ΡΠΈΡΠΊΠ° Π²ΡΡΠ²Π»ΡΠ»Π°ΡΡ Π½Π΅ΠΎΠ΄Π½ΠΎΡΠΎΠ΄Π½Π°Ρ ΡΡ
ΠΎΡΡΡΡΠΊΡΡΡΠ° ΡΠ°Π·ΠΌΠ΅ΡΠ°ΠΌΠΈ 14 ΠΌΠΌ, 13,7 ΠΌΠΌ ΠΈ 12 ΠΌΠΌ Ρ ΡΠ΅ΡΠΊΠΈΠΌ, ΡΠΎΠ²Π½ΡΠΌ ΠΊΠΎΠ½ΡΡΡΠΎΠΌ. Π Π΅Π·ΡΠ»ΡΡΠ°ΡΡ ΠΈΠΌΠΌΡΠ½ΠΎΡΠ΅ΡΠΌΠ΅Π½ΡΠ½ΠΎΠ³ΠΎ Π°Π½Π°Π»ΠΈΠ·Π° ΠΊΡΠΎΠ²ΠΈ Π½Π΅ ΠΏΠΎΠΊΠ°Π·Π°Π»ΠΈ ΡΠ²Π΅Π»ΠΈΡΠ΅Π½ΠΈΠ΅ ΠΎΡΠ½ΠΎΠ²Π½ΡΡ
ΠΌΠ°ΡΠΊΠ΅ΡΠΎΠ² ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΠΎΠ³ΠΎ ΠΏΡΠΎΡΠ΅ΡΡΠ°. ΠΡΠΈ Π±ΠΈΠΎΡ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΎΠΌ ΡΠ΅ΡΡΠΈΡΠΎΠ²Π°Π½ΠΈΠΈ ΠΊΡΠΎΠ²ΠΈ ΠΎΡΠΌΠ΅ΡΠ°Π»ΠΎΡΡ Π½Π΅Π·Π½Π°ΡΠΈΡΠ΅Π»ΡΠ½ΠΎΠ΅ ΠΏΠΎΠ²ΡΡΠ΅Π½ΠΈΠ΅ ΡΡΠΎΠ²Π½Ρ ΠΏΡΡΠΌΠΎΠ³ΠΎ Π±ΠΈΠ»ΠΈΡΡΠ±ΠΈΠ½Π° ΠΈ ΡΡΠ²ΠΎΡΠΎΡΠΎΡΠ½ΠΎΠ³ΠΎ ΠΆΠ΅Π»Π΅Π·Π°. ΠΠ»Ρ ΡΡΠΎΡΠ½Π΅Π½ΠΈΡ Π΄ΠΈΠ°Π³Π½ΠΎΠ·Π° ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½Π° ΠΌΠ°Π³Π½ΠΈΡΠ½ΠΎ-ΡΠ΅Π·ΠΎΠ½Π°Π½ΡΠ½Π°Ρ ΡΠΎΠΌΠΎΠ³ΡΠ°ΡΠΈΡ ΠΎΡΠ³Π°Π½ΠΎΠ² ΠΌΠ°Π»ΠΎΠ³ΠΎ ΡΠ°Π·Π° Ρ Π²Π½ΡΡΡΠΈΠ²Π΅Π½Π½ΡΠΌ ΠΊΠΎΠ½ΡΡΠ°ΡΡΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ. ΠΠΎΡΠ»Π΅ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΈΡ ΡΠΊΠ°Π·Π°Π½Π½ΠΎΠ³ΠΎ ΠΎΠ±ΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ Π±ΡΠ» Π²ΡΡΡΠ°Π²Π»Π΅Π½ Π΄ΠΈΠ°Π³Π½ΠΎΠ· "ΠΊΠΈΡΡΠΎΠ·Π½ΠΎΠ΅ ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΠ΅ ΠΏΡΠ°Π²ΠΎΠ³ΠΎ ΡΠΈΡΠΊΠ°". ΠΠΎΡΠ»Π΅ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΈΡ Π½Π΅ΠΎΠ±Ρ
ΠΎΠ΄ΠΈΠΌΡΡ
Π΄ΠΎΠΏΠΎΠ»Π½ΠΈΡΠ΅Π»ΡΠ½ΡΡ
Π΄ΠΈΠ°Π³Π½ΠΎΡΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΌΠ΅ΡΠΎΠΏΡΠΈΡΡΠΈΠΉ (Π£ΠΠ ΠΏΠ΅ΡΠΈΡΠ΅ΡΠΈΡΠ΅ΡΠΊΠΈΡ
Π»ΠΈΠΌΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΠ·Π»ΠΎΠ², ΠΎΠ±ΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ Π±ΡΡΡΠ½ΠΎΠΉ ΠΏΠΎΠ»ΠΎΡΡΠΈ Ρ Π²Π½ΡΡΡΠΈΠ²Π΅Π½Π½ΡΠΌ ΠΊΠΎΠ½ΡΡΠ°ΡΡΠ½ΡΠΌ ΡΡΠΈΠ»Π΅Π½ΠΈΠ΅ΠΌ) Π²ΡΠΏΠΎΠ»Π½Π΅Π½Π° ΠΎΠΏΠ΅ΡΠ°ΡΠΈΡ, Π·Π°ΠΊΠ»ΡΡΠ°Π²ΡΠ°ΡΡΡ Π² ΡΠ΅Π²ΠΈΠ·ΠΈΠΈ ΠΏΡΠ°Π²ΠΎΠΉ ΠΏΠΎΠ»ΠΎΠ²ΠΈΠ½Ρ ΠΌΠΎΡΠΎΠ½ΠΊΠΈ ΠΈ ΡΠ΄Π°Π»Π΅Π½ΠΈΠΈ ΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΡ ΠΏΡΠ°Π²ΠΎΠ³ΠΎ ΡΠΈΡΠΊΠ°. ΠΠ½ΡΡΠ°ΠΎΠΏΠ΅ΡΠ°ΡΠΈΠΎΠ½Π½ΠΎ ΠΏΠΎ Π΄Π°Π½Π½ΡΠΌ ΡΠΊΡΠΏΡΠ΅ΡΡ-Π±ΠΈΠΎΠΏΡΠΈΠΈ Π΄ΠΈΠ°Π³Π½ΠΎΡΡΠΈΡΠΎΠ²Π°Π»Π°ΡΡ Π΄Π΅ΡΠΌΠΎΠΈΠ΄Π½Π°Ρ ΠΊΠΈΡΡΠ° ΠΏΡΠ°Π²ΠΎΠ³ΠΎ ΡΠΈΡΠΊΠ°, ΡΡΠΎ ΠΏΠΎΠ΄ΡΠ²Π΅ΡΠ΄ΠΈΠ»ΠΎΡΡ ΠΏΡΠΈ ΠΏΠΎΡΠ»Π΅Π΄ΡΡΡΠ΅ΠΌ Π³ΠΈΡΡΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΎΠΌ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠΈ. ΠΠΎΡΠ»Π΅ΠΎΠΏΠ΅ΡΠ°ΡΠΈΠΎΠ½Π½ΡΠΉ ΠΏΠ΅ΡΠΈΠΎΠ΄ ΠΏΡΠΎΡΠ΅ΠΊΠ°Π» Π³Π»Π°Π΄ΠΊΠΎ. ΠΠ°ΡΠΈΠ΅Π½Ρ Π²ΡΠΏΠΈΡΠ°Π»ΡΡ Π² ΡΠ΄ΠΎΠ²Π»Π΅ΡΠ²ΠΎΡΠΈΡΠ΅Π»ΡΠ½ΠΎΠΌ ΡΠΎΡΡΠΎΡΠ½ΠΈΠΈ. Π’Π°ΠΊΠΈΠΌ ΠΎΠ±ΡΠ°Π·ΠΎΠΌ, ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½Π½ΠΎΠ΅ ΠΊΠ»ΠΈΠ½ΠΈΡΠ΅ΡΠΊΠΎΠ΅ Π½Π°Π±Π»ΡΠ΄Π΅Π½ΠΈΠ΅ ΠΏΠΎΠ΄ΡΠ΅ΡΠΊΠΈΠ²Π°Π΅Ρ Π½Π΅ΠΎΠ±Ρ
ΠΎΠ΄ΠΈΠΌΠΎΡΡΡ ΠΎΠΏΡΠΈΠΌΠΈΠ·Π°ΡΠΈΠΈ ΠΏΡΠΎΡΠΈΠ»Π°ΠΊΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠ°Π±ΠΎΡΡ ΠΌΠ΅Π΄ΠΈΡΠΈΠ½ΡΠΊΠΎΠ³ΠΎ ΠΏΠ΅ΡΡΠΎΠ½Π°Π»Π° ΠΏΠ΅ΡΠ²ΠΈΡΠ½ΠΎΠ³ΠΎ Π·Π²Π΅Π½Π° ΠΏΠΎ ΡΠ²ΠΎΠ΅Π²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠΉ Π΄ΠΈΠ°Π³Π½ΠΎΡΡΠΈΠΊΠ΅ ΠΎΠΏΡΡ
ΠΎΠ»Π΅Π²ΡΡ
ΠΏΡΠΎΡΠ΅ΡΡΠΎΠ² Π½Π°ΡΡΠΆΠ½ΡΡ
ΠΏΠΎΠ»ΠΎΠ²ΡΡ
ΠΎΡΠ³Π°Π½ΠΎΠ², ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎ Ρ Π΄Π΅ΡΠ΅ΠΉ ΠΏΡΠ±Π΅ΡΡΠ°ΡΠ½ΠΎΠ³ΠΎ Π²ΠΎΠ·ΡΠ°ΡΡΠ°.The paper presents a clinical case of a 14-year-old child with a dermoid cyst of the right testicle. The formation was first detected during a routine check-up in the polyclinic. Then the external genitalia ultrasound examination was repeatedly performed to the patient, which revealed an inhomogeneous echostructure with dimensions of 14 mm, 13.7 mm and 12 mm with a clear, even contour in the upper pole of the right testicle. The enzyme-linked immunosorbent assay (ELISA) did not show an increase in the main tumour markers. The biochemical blood test revealed an insignificant rise in conjugated bilirubin and serum iron. To clarify the diagnosis, magnetic resonance tomography of the pelvic organs with intravenous contrast was recommended. After examination, the cystic lesion of the right testicle was diagnosed. After carrying out the necessary additional diagnostic measures (ultrasound examination of the peripheral lymphatic nodes, the abdominal cavity exploration with intravenous contrast enhancement), the child underwent an operation consisting in revising the right half of the scrotum and removing the formation of the right testicle. Intraoperatively, according to the express biopsy test, the dermoid cyst of the right testicle was diagnosed, which was confirmed by the subsequent histological examination. The postoperative period was uneventful. The patient was discharged in satisfactory state. Thus, the presented clinical observation emphasizes the need to optimize the preventive work of primary care medical personnel for timely diagnosis of tumor processes in the external genital organs, especially in children of puberty
Intense high-order harmonic generation in giant fullerene molecule C
In this work the extreme nonlinear optical response of a giant fullerene
molecule C in strong laser field is studied. The investigation of
high-order harmonic generation in such quantum nanostructure is presented
modeling the C molecule and its interaction with the laser field in the
scope of the tight-binding mean-field approach. Electron-electron interaction
is modeled by the parametrized Ohno potentail, which takes into account
long-range Coulomb interaction. The essential role of many body Coulomb
interaction in determining of harmonics intensities is demonstrated. We also
consider vacancy-deffected molecule C. The presence of a single vacancy
breaks the icosahedral symmetry leading to the emergence of intense even-order
harmonics. We examine the dependence of moderate harmonics on laser frequency
that shows the multiphoton resonant nature of high harmonics generation. The
dependence of cutoff harmonics on both laser intensity and frequency are
examined too.Comment: 9 pages, 10 figure
High order fluid model for streamer discharges
A high order fluid model for streamer discharges is developed and used to investigate propagation of negative streamer fronts in N2 . Mo- mentum transfer theory is employed to evaluate the collision terms and close the system of moment/balance equations. The results of simulations are compared with those obtained by a PIC/MC method and by the classical first order fluid model based on the drif
Magnetic Properties of J-J-J' Quantum Heisenberg Chains with Spin S=1/2, 1, 3/2 and 2 in a Magnetic Field
By means of the density matrix renormalization group (DMRG) method, the
magnetic properties of the J-J-J quantum Heisenberg chains with spin
, 1, 3/2 and 2 in the ground states are investigated in the presence of
a magnetic field. Two different cases are considered: (a) when is
antiferromagnetic and is ferromagnetic (i.e. the AF-AF-F chain),
the system is a ferrimagnet. The plateaus of the magnetization are observed. It
is found that the width of the plateaus decreases with increasing the
ferromagnetic coupling, and disappears when passes over a
critical value. The saturated field is observed to be independent of the
ferromagnetic coupling; (b) when is ferromagnetic and is
antiferromagnetic (i.e. the F-F-AF chain), the system becomes an
antiferromagnet. The plateaus of the magnetization are also seen. The width of
the plateaus decreases with decreasing the antiferromagnetic coupling, and
disappears when passes over a critical value. Though the ground
state properties are quite different, the magnetization plateaus in both cases
tend to disappear when the ferromagnetic coupling becomes more dominant.
Besides, no fundamental difference between the systems with spin half-integer
and integer has been found.Comment: 8 pages, 9 figures, to be published in J. Phys.: Condens. Matte
Comparing plasma fluid models of different order for 1D streamer ionization fronts
We evaluate the performance of three plasma fluid models: the first order
reaction-drift-diffusion model based on the local field approximation; the second order
reaction-drift-diffusion model based on the local energy approximation and a recently
developed high order fluid model by Dujko et al (2013 J. Phys. D 46 475202) We first review
the fluid models: we briefly discuss their derivation, their underlying assumptions and the
type of transport data they require. Then we compare these models to a particle-in-cell/Monte
Carlo (PIC/MC) code, using a 1D test problem. The tests are performed in neon and nitrogen
at standard temperature and pressure, over a wide range of reduced electric fields. For the fluid
models, transport data generated by a multi-term Boltzmann solver are used. We analyze the
observed differences in the model predictions and address some of the practical aspects when
using these plasma fluid models
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