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

ДЕРМОИДНАЯ КИСТА /ДИАГНДЕРМОИД /ДИАГНЯИЧКИ /УЛЬТРАСОНДЕТИКЛИНИЧЕСКИЕ СЛУЧАИВ работе представлен клинический случай ребенка, 14 лет, с дермоидной кистой правого яичка. Образование впервые было выявлено при профилактическом осмотре в поликлинике. В последующем пациенту неоднократно проводилось ультразвуковое исследование наружных половых органов, при котором в верхнем полюсе правого яичка выявлялась неоднородная эхоструктура размерами 14 мм, 13,7 мм и 12 мм с четким, ровным контуром. Результаты иммуноферментного анализа крови не показали увеличение основных маркеров опухолевого процесса. При биохимическом тестировании крови отмечалось незначительное повышение уровня прямого билирубина и сывороточного железа. Для уточнения диагноза проведена магнитно-резонансная томография органов малого таза с внутривенным контрастированием. После проведения указанного обследования был выставлен диагноз "кистозное образование правого яичка". После проведения необходимых дополнительных диагностических мероприятий (УЗИ периферических лимфатических узлов, обследование брюшной полости с внутривенным контрастным усилением) выполнена операция, заключавшаяся в ревизии правой половины мошонки и удалении образования правого яичка. Интраоперационно по данным экспресс-биопсии диагностировалась дермоидная киста правого яичка, что подтвердилось при последующем гистологическом исследовании. Послеоперационный период протекал гладко. Пациент выписался в удовлетворительном состоянии. Таким образом, представленное клиническое наблюдение подчеркивает необходимость оптимизации профилактической работы медицинского персонала первичного звена по своевременной диагностике опухолевых процессов наружных половых органов, особенно у детей пубертатного возраста.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 C240_{240}

In this work the extreme nonlinear optical response of a giant fullerene molecule C$_{240}$ in strong laser field is studied. The investigation of high-order harmonic generation in such quantum nanostructure is presented modeling the C$_{240}$ 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$_{240}$. 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$^{\prime}$ quantum Heisenberg chains with spin $S=1/2$, 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 $J$ is antiferromagnetic and $J^{\prime}$ 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 $J$ is ferromagnetic and $J^{\prime}$ 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 $J^{\prime}/J$ 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