Effects of a moving X-line in a time-dependent reconnection model

In the frame of magnetized plasmas, reconnection appears as an essential process for the description of plasma acceleration and changing magnetic field topology. Under the variety of reconnection regions in our solar system, we focus our research onto the Earth's magnetotail. Under certain conditions a Near Earth Neutral Line (NENL) is free to evolve in the current sheet of the magnetotail. Reconnection in this region leads to the formation of Earth- and tailward propagating plasma bulges, which can be detected by the Cluster or Geotail spacecraft. Observations give rise to the assumption that the evolved reconnection line does not provide a steady state behavior, but is propagating towards the tail (e.g., Baker et al., 2002). Based on a time-dependent variant of the Petschek model of magnetic reconnection, we present a method that includes an X-line motion and discuss the effects of such a motion. We focus our main interest on the shock structure and the magnetic field behavior, both for the switch-on and the switch-off phase

ANALYSIS OF THE RESULTS OF SURGICAL PROCEDURES ADVISABLE FOR CHRONIC PANCREATITIS WITH THE PREDOMINANT LESION OF THE PANCREATIC HEAD

Recently, studies comparing various variants of operations to establish the optimal method of surgical treatment for chronic pancreatitis with pancreatic head lesions from the point of view of evidence-based medicine have been carried out in the world. However, these comparative studies do not take into account differences in the clinical and morphological forms of the disease, in particular, chronic pancreatitis with a predominant and isolated lesion of the head. Subtotal resection of the pancreatic head with proximal pancreatojejunostomy, suitable for an isolated lesion of the head, does not solve all the problems of chronic pancreatitis with a predominant lesion of the head. In this case, the violation of the outflow of pancreatic juice along the pathologically changed main pancreatic duct from the left half of the gland is not eliminated. It is impossible to unambiguously support the hypothesis of the feasibility of performing subtotal resection of the pancreatic head with proximal pancreatojejunostomy in chronic pancreatitis with a predominant lesion of the head with a uniformly expanded main pancreatic duct. With this form of chronic pancreatitis, cicatricial strictures can form in the main pancreatic duct, which can lead to ductal hypertension and serve as an indication for reoperation. The feasibility of using Beger operation in chronic pancreatitis with a predominant lesion of the head is doubtful, since the intersection of the isthmus and the need for a T-shaped longitudinal pancreatojejunostomy makes this intervention technically difficult and unsafe. Based on the studies performed, it is impossible to say with certainty about the reliable advantages of one type of operations over another. To obtain reliable results, it’s necessary to conduct evidence-based studies comparing subtotal resection of the pancreatic head with longitudinal pancreatojejunostomy with other types of interventions only for chronic pancreatitis with a predominant head lesion, excluding from the study patients with chronic pancreatitis with isolated head lesion

Хирургическое лечение глаукомы c применением дренажей у пациентов с артифакией

This review summarizes the results of surgical treatment of faradvanced stage glaucoma in the only seeing eye. A literature search performed in the PubMed search engine and aimed at finding publications reporting the clinical outcomes of treatment in patients with glaucoma in the only seeing eye did yield sufficient data related to the topic. A comprehensive analysis of the available data was performed with an emphasis on the choice of treatment tactics and postoperative results at various times following a surgery. Several studies allowed to perform a comparison of the clinical advantages and costeffectiveness of medical treatment versus surgery for advanced glaucoma, as well as to assess potential risks and adverse outcomes such as glaucoma progression, postoperative scarring, hypotension and other complications. The results presented in this review suggest that common success criteria can provide uniformity in academic studies, but in daily clinical practice each glaucoma specialist must make a patientspecific decision in favor of either of these methods of treatment in order to guarantee an optimal result, both for the doctor and, of course, for the patient.Обзор исследований, касающихся особенностей изменений анатомии глаза и гидродинамики внутриглазной жидкости у пациентов с артифакией и с присутствующими в данной группе пациентов возрастными изменениями. Наиболее трудно поддающейся лечению является рефрактерная глаукома, к которой, в том числе, относится глаукома на артифакичном глазу. Наиболее успешным методом лечения данной категории пациентов является дренажная хирургия. Нами проведен анализ отечественных и зарубежных исследований с описанием свойств и оценкой эффективности дренажных устройств от момента их изобретения до сегодняшних дней. Изучены работы, посвященные борьбе с рубцеванием хирургически сформированных путей оттока, в том числе с применением антиметаболитов и стероидов. Однако так как многообразие методов хирургического лечения не обеспечивает стойкого гипотензивного результата у пациентов с артифакией, дальнейший поиск оптимального дренажа остается актуальным

Targeted Disruption of the PME-1 Gene Causes Loss of Demethylated PP2A and Perinatal Lethality in Mice

Phosphoprotein phosphatase 2A (PP2A), a major serine-threonine protein phosphatase in eukaryotes, is an oligomeric protein comprised of structural (A) and catalytic (C) subunits to which a variable regulatory subunit (B) can associate. The C subunit contains a methyl ester post-translational modification on its C-terminal leucine residue, which is removed by a specific methylesterase (PME-1). Methylesterification is thought to control the binding of different B subunits to AC dimers, but little is known about its physiological significance in vivo.Here, we show that targeted disruption of the PME-1 gene causes perinatal lethality in mice, a phenotype that correlates with a virtually complete loss of the demethylated form of PP2A in the nervous system and peripheral tissues. Interestingly, PP2A catalytic activity over a peptide substrate was dramatically reduced in PME-1(-/-) tissues, which also displayed alterations in phosphoproteome content.These findings suggest a role for the demethylated form of PP2A in maintenance of enzyme function and phosphorylation networks in vivo

Energy balance in the course of relativistic magnetic reconnection

Magnetic reconnection plays an important role in space physics, for example, in Earth's magnetosphere, on the Sun, in the magnetospheres of magnetars, pulsars, black holes, etc. Reconnection starts with abrupt drop of plasma conductivity in a small part of a current sheet, so called, diffusion region. As a result electric field is generated and is transferred by relativistic MHD surface wave from the diffusion region to the current sheet which leads to decay of the disturbed part of the current sheet into a system of slow shocks. Plasma is highly accelerated and heated at the shock fronts forming outflow region with relativistic plasma jets and weak magnetic field (Semenov & Bernikov 1991). At some stage the reconnection process has to switch-off, then outflow regions must detach from the site where the electric field was initiated, and propagate along the current sheet as solitary waves (Tolstykh et al. 2005). The energy balance of relativistic reconnection is investigated in details. It is shown that magnetic and thermal energy from the inflow region is spent for acceleration and heating of the plasma in jets. It is interesting that the temperature of the plasma in the wake of the propagating outflow regions drops after each pulse of reconnection. This differ from usual explosion which heats the plasma behind the shock front (Tolstykh et al. 2007).