A petromagnetic and paleomagnetic study of sediments of the Tarkhanian Regional Stage of the Skelya section (Kerch Peninsula, East Paratethys) has been conducted. Titanomagnetite is the main carrier ...of the natural remanent magnetization (NRM) in the Argunian beds of the Tarkhanian Regional Stage; the Terskian and Kuvinian beds contain Fe sulfide (monoclinic pyrrhotite and/or greigite) in addition to titanomagnetite. The paleomagnetic fold test directions of NRM of the Argunian sequences is positive, which indicates a prefolding age of the formation of magnetization. Comparison with the GTS 2020 magnetochronological scale shows that the ranges of normal and reverse polarity in the lower and upper parts of the Argunian sediments can probably be compared with chrons C5Bn and C5ADr, respectively; the age of the С5Bn/C5ADr boundary can be estimated at ~14.7 Ma.
—We present the rock-magnetic and palaeomagnetic results of the Sarmatian-Maeotian (Upper Miocene) sediments of the key sections of Cape Popov Kamen and Cape Panagia from Taman Peninsula (Eastern ...Paratethys) and forming the flanks of a single synclinal fold. A three-component composition of magnetization has been detected. The first is the viscous component
A
, the second is the component B, which is intermediate between the components
A
and the third component C, which tends to zero in the Zijderveld diagram. The directions of component
B
are characterized by northern–northeastern–eastern declinations and positive inclinations in the stratigraphic coordinate system; the fold test for the Popov Kamen and Panagia results is negative, and the magnetization is post-folding. The directions of component
C
have negative inclinations and southern declinations in the stratigraphic coordinate system. Paleomagnetic results for two sections showed the test fold positive, magnetization preliminary and the magnetization is pre-folding. Components
B
and
C
, on the basis of which the polarity of the magnetozones is determined, are of different ages, and the palaeomagnetic record of component
B
is the result of complete or partial remagnetization, which makes it impossible to use magnetostratigraphy for section dating. Our work affects an important question about the reliability of palaeomagnetic data on the Miocene deposits of the Kerch-Taman region (Eastern Paratethys).
Abstract
The article considers the issue of developing a meat and vegetable product from local raw materials. The meat part is sub-products (collagen-rich pig ears and liver with high nutritional ...qualities) – raw materials, usually with low cost, but with proper processing with high taste, technological and nutritional properties. Local plant raw materials are represented by a not yet widespread crop chickpeas, which perfectly forms a crop in arid conditions of the Volgograd region of the Russian Federation, rich in vegetable protein, other macro- and micronutrients, and in addition, because it is a legume, enriches the light brown soils of the region with nitrogen due to symbiotic microorganisms. The developed product has high taste properties, contains an optimal set of macro- and micronutrients and can be called functional because 1 serving of the product contains more than 15% of average daily needs.
Hypothermia for neuroprotection and correction of intracranial hypertension was described in both experimental and clinical studies. Effectiveness of hypothermia for improvement of functional ...outcomes in neurosurgical patients is still unclear despite the previous randomized trials. In available national and foreign literature, we found no trials devoted to hypothermia in patients with ischemia after surgical treatment of complex aneurysms of the middle cerebral artery (MCA).
To analyze the effectiveness of intravascular hypothermia in patients with ischemic cerebrovascular accidents in early postoperative period after microsurgical clipping of complex MCA aneurysms.
We present four patients with cerebral ischemia after microsurgical treatment of complex MCA aneurysms. In all cases, ischemic disorders developed immediately after surgery. We induced intravascular hypothermia 32-34 °C in all patients. CT-based volumetry of ischemia and edema foci was performed to objectively assess the dynamics of ischemic disorders. We carried out volumetry using segmentation of edema and ischemia foci (range 5-33 Hounsfield units).
According to brain CT data, all four patients had enlargement of postoperative ischemic brain damage. Nevertheless, ICP was stable that made it possible to avoid decompressive craniotomy.
Early hypothermia for acute ischemic injury after surgery for complex MCA aneurysms can reduce ischemic perifocal edema. This approach effectively reduces ICP and can exclude the need for decompressive craniotomy in some cases. No side effects of hypothermia justifies further research in this field.
Results are presented from a study of the influence on the startup modes of transformers of sign-constant currents in the windings of power transformers that may be related to geomagnetic ...perturbations in the earth’s magnetosphere and ionosphere and to electromagnetic processes in electric power systems. Magnetization processes in power transformers produced by geoinduced currents (GIC) with hysteresis taken into account are analyzed. Acomputational study is based on a model of a segment of the 500 kV grid using the EMTP-RV program (PowerSys, France) which can be used for calculations of transient processes in nonlinear electrical circuits with hysteresis taken into account. It is argued that GIC must be taken into account in calculations of the thermal and electrodynamic stability of transformers when choosing the settings for relay protections.
Decompressive craniectomy is used for arresting hypertension-dislocation syndrome developing in seriuos patients in the acute period of subarachnoid hemorrhage. After stabilization of the patient's ...neurological and somatic status, cranioplasty is performed for protective, cosmetic, and therapeutic purposes. The most common surgery in these patients is skull repair using an autologous bone graft. Before cranioplasty, the patient's bone is preserved in two ways: cryopreservation or subcutaneous implantation to the anterior abdominal wall area. Recently, there have been numerous reports of early and delayed complications of cranioplasty with autologous bone grafts. The use of artificial grafts may reduce the risk of postoperative complications compared to an autologous bone graft. Previously, 'freely' or 'manually' simulated biopolymers were used. At present, they are rarely used for repair of extensive defects due to a poor cosmetic result. However, the advent of stereolithographic modeling and computer modeling of artificial grafts has improved the cosmetic result of this surgery. The purpose of this study is to assess the risk of postoperative complications of cranioplasty as well as to define the criteria for choosing a cranioplasty technique.
In recent years, significant attention has been paid to preventive vascular neurosurgery. Treatment of unruptured asymptomatic brain aneurysms is one of the sections of this surgery.
To evaluate ...treatment outcomes in patients with unruptured asymptomatic brain aneurysms who underwent treatment chosen on the basis of criteria adopted at the Burdenko Neurosurgery Center.
There were 2814 unruptured asymptomatic brain aneurysms in 2334 patients for the period from 1995 to 2019.
Microsurgical operations for unruptured asymptomatic brain aneurysms were performed in 64.9% of cases, endovascular procedures - in 35.1% of patients. Endovascular operations were usually performed for ICA aneurysms and posterior aneurysms of circle of Willis. Microsurgical operations were mainly performed in patients with aneurysms of anterior and middle cerebral arteries. Favorable outcomes (GOS grade V-IV) were obtained in most patients (98.3%). Incidence of severe complications was similar in both groups, mortality rate was 0.3% and 0.4%, respectively.
Currently, there is a tendency towards annual increase in the number of surgeries for unruptured brain aneurysms. Anatomical and morphological characteristics of aneurysm should be considered to achieve favorable clinical results. At the same time, comprehensive analysis of each case and identification of individual risk factors will eliminate serious complications of surgical treatment.
Giant cerebral aneurysms are diagnosed more often in children than in adults. Treatment of giant aneurysms is carried out both by endovascular and microsurgical methods. Literature information on ...combination of microsurgical and endovascular operations of cerebral aneurysms at children is little. A clinical case of the combined treatment of a giant bicameral fusiform partially thrombosed aneurysm of the right vertebral artery at a 12-year-old patient and a literature review on this topic are presented. The patient underwent several complex neurosurgical interventions during two operations: 1) microsurgery including revascularization of the right posterior lower cerebellar artery, thrombectomy and trapping of the larger chamber of fusiform aneurysm of the right vertebral artery, and 2) endovascular, which consists in the installation of redirecting stent from the left vertebral artery to main artery. The uniqueness of the case which we presented lies in the fact that the tactics of stage combined treatment for a complex aneurysm at child was originally planned and successfully implemented. The treatment allowed to ensure a complete shutdown of aneurysm and to exclude postoperative cerebral complications.
To develop a classification of the completeness of brain aneurysm exclusion according to CT angiography for determining further diagnostic and curative strategy.
The study included 138 patients who ...had 164 brain aneurysms. Clipping was carried out at the Burdenko Neurosurgery Center in 2013-2017. Titanium clips were used in 111 cases, cobalt clips - in 53 patients.
Completeness of brain aneurysm exclusion was assessed in 149 cases using CT angiography. In 15 cases, artifacts from cobalt clips impaired assessment. Total exclusion was achieved in 136 (91.3%) cases, subtotal (a remainder of residual neck) - in 10 (6.7%) cases, complete exclusion of the body and bottom (patent neck) - 2 (1.3%) patients, partial exclusion (partially patent bottom) - 1 patient (0.7%). In this series, a clip prevented complete contrast enhancement of brain aneurysm bottom in all cases.
CTA is a reliable method for assessing the quality of exclusion of brain aneurysm in patients with implanted titanium clips. In case of cobalt clips, stratification depending on severity of CT artifacts should be performed for data interpretation. In some cases, artifacts impair visualization of the vessels adjacent to the clips. In these patients, direct cerebral angiography or dual-energy computed tomography scanners with metal artifact suppression programs should be recommended.
Follow-up is recommended for patients with remnants of residual cervix. Redo surgery is indicated for completely patent neck, as well as partial or complete contrast enhancement of aneurysm bottom.
