New Spin-Polarized Electron Source Based on Alkali Antimonide Photocathode.

New spin-dependent photoemission properties of alkali antimonide semiconductor cathodes are predicted based on the detected optical spin orientation effect and DFT band structure calculations. Using these results, the Na_{2}KSb/Cs_{3}Sb heterostructure is designed as a spin-polarized electron source in combination with the Al_{0.11}Ga_{0.89}As target as a spin detector with spatial resolution. In the Na_{2}KSb/Cs_{3}Sb photocathode, spin-dependent photoemission properties were established through detection of a high degree of photoluminescence polarization and high polarization of the photoemitted electrons. It was found that the multi-alkali photocathode can provide electron beams with emittance very close to the limits imposed by the electron thermal energy. The vacuum tablet-type sources of spin-polarized electrons have been proposed for accelerators, which can exclude the construction of the photocathode growth chambers for photoinjectors.

[Ultrastructure of neointima of native and artificial elements of the blood circulatory system]. / Ul'trastruktura neointimy nativnykh i iskusstvennykh elementov sistemy krovoobrashcheniya.

OBJECTIVE: To compare the neointima structure in conduits for coronary bypass grafting, bioprosthetic heart valves, tissue-engineered vascular grafts, and metal stents. MATERIAL AND METHODS: The objects of the study were the fragments of the human internal thoracic artery, experimental biodegradable vascular prostheses, leaflets of xenopericardial bioprostheses of heart valves, and fragments of stented vessels. Tissue samples were fixed in formalin and post-fixed in osmium tetroxide. After dehydration and epoxy resin embedding, the samples were ground and polished. Samples were counterstained with uranyl acetate and lead citrate and visualized by means of backscattered scanning electron microscopy. RESULTS: Neointimal pattern in all samples was similar. Neointima was comprised of endothelial cells, smooth muscle cells, fibroblasts, and the extracellular matrix. Endothelial cells showed significant diversity both between different elements of the circulatory system and within the same tissue, having either elongated or polygonal shape. Adhesion of leukocytes testified to the endothelial cell activation. In the absence of inflammation in the superficial layer of the neointima, the arrangement of smooth muscle cells and extracellular matrix fibers was parallel to the endothelium. Clusters of foam cells were frequently detected around the neointimal layers with solid inclusions (metal stents or calcium deposits). Thickening of the neointima was accompanied by the presence of capillaries and capillary-like structures. CONCLUSION: Neointima formation is a typical response to the damage inflicted to the elements of the circulatory system. Neointima underwent a constant remodeling characterized by an altered cellular composition, macrophage invasion, neovascularization, and calcification.

[Modern aspects of the treatment of submacular hemorrhages secondary to macular degeneration]. / Sovremennye aspekty terapii submakulyarnykh krovoizliyanii na fone makulyarnoi degeneratsii.

Age-related macular degeneration complicated by submacular hemorrhage if not treated timely leads to permanent loss of central vision. The basis of effective therapy is its early start, dislocation of blood from central parts of the retina and blockage of neovascularization. This review examines the current methods of treatment of submacular hemorrhages, anatomical and functional outcomes, risks of postoperative complications, as well as trends in the use of combined methods of surgical intervention.

[Peculiarities of diagnosis and emergency surgical care in aorto-oesophageal fistula]. / Osobennosti diagnostiki i neotlozhnoi khirurgicheskoi pomoshchi pri aorto-pishchevodnom svishche.

An aorto-oesophageal fistula is a rare but life-threatening pathological condition developing on the background of diseases of the aorta and oesophagus, as well as after surgical interventions on the aorta. The article deals with a clinical case report regarding management of a patient presenting with an aorto-oesophageal fistula resulting from a thoracic artery aneurysm. The main clinical manifestations of the diseases included dysphagia (due to oesophageal obstruction caused by thrombotic masses of the aneurysm) and the occurring gastrointestinal haemorrhage. Comprehensive instrumental diagnosis was performed using roentgen examination of the oesophagus, oesophagoscopy, and contrast-enhanced computed tomography of the chest. The obtained findings made it possible to objectively assess the patient's state, to carry out timely treatment in conditions of a surgical hospital, and to avoid severe complications.

Spectral detection of spin-polarized ultra low-energy electrons in semiconductor heterostructures.

The circularly polarized cathodoluminescence (CL) technique has been used to study the free spin-polarized electron injection in semiconductor heterostructures with quantum wells (QWs). A polarized electron beam was created by the emission of optically oriented electrons from the p-GaAs(Cs,O) negative electron affinity (NEA) photocathode. The prepared beam was injected in a semiconductor QW target, which was activated by cesium and oxygen to reduce the work function. To study the spin-dependent injection, we developed a spin-detector prototype, which consists of a compact proximity focused vacuum tube with the source and target placed parallel to each other on the opposite ends of the vacuum tube (photodiode). The injection of polarized low-energy electrons into the target by varying the kinetic energy in the range of 0.5-5.0 eV and temperature in the range of 90-300 K was studied. The CL was polarized to 2 % by the injection of 20 % spin-polarized electron beam with the energy of 0.5 eV at room temperature. The asymmetry (Sherman function) of spin detection was estimated. It was shown that the dependence of the CL polarization degree on the injected electron energy is satisfactory described by the model that considers the electron spin relaxation in the heterostructure matrix and QWs. The results demonstrate that semiconductor detectors are promising for the spin-polarimetry applications based on the optical detection of free-electron spin polarization.

[Surgical treatment of a patient with saccular arterial aneurysm of the cavernous-ophthalmic segment]. / Khirurgicheskoe lechenie bol'nogo s meshotchatoi arterial'noi anevrizmoi kavernozno-oftal'micheskogo segmenta.

Presented in the article are the results of surgical management of a patient with an extremely rare pathology - a saccular arterial aneurysm of the cavernous-ophthalmic segment of the left internal carotid artery. We performed multistage open surgical intervention in the following scope: osteoplastic pterional craniotomy on the left, creation of a wide-lumen anastomosis between the left external carotid artery and M2 segment of the left middle cerebral artery with the use of the radial artery, ligation of the cervical portion of the left internal carotid artery and clipping of its supraclinoid portion. The chosen surgical policy made it possible to create sufficient volumetric blood flow through the shunt, comparable to the blood flow through the internal carotid artery, which helped avoid ischaemic stroke after exclusion of the aneurysm from circulation. A conclusion was drawn on efficacy of this method of treatment.

[Predictors of long-term complications after carotid endarterectomy]. / Prediktory oslozhnenii v otdalennom periode posle karotidnoi éndarteréktomii.

AIM: To analyze the predictors of complications within 3 years after carotid endarterectomy (CEE). MATERIAL AND METHODS: The study included 1035 patients after CEE for the period 2011-2016. Long-term follow-up period was 42.4±18.6 months (≈ 3.5 years). The endpoints were such unfavorable cardiovascular events as death, myocardial infarction, stroke/transient ischemic attack, redo revascularization. Statistical analysis was carried out by using of Statistica for Windows 8.0 software package (StatSoft Inc., USA). Stepwise logistic regression was applied to identify risk factors of adverse outcomes and death in long-term postoperative period. RESULTS: Comprehensive analysis of numerous factors (anamnestic, instrumental-diagnostic, surgical) allowed us to identify predictors of long-term unfavorable outcomes in patients with occlusive-stenotic lesions of carotid arteries. Risk factors of long-term complications were SYNTAX score ≥33 (high risk), unstable plaque in the contralateral ICA, occlusion of contralateral ICA, LVEF <39%, ICA cross-clamping >40 min, previous CABG. CONCLUSION: These data are extremely important and can be used to create prognostic models. The last ones are necessary to determine optimal treatment strategy in patients with occlusive-stenotic lesions of supra-aortic vessels.

[Surgical treatment of protoplasmic astrocytoma of sylvian aqueduct involving posterior part of the third ventricle]. / Khirurgicheskoe lechenie protoplazmaticheskoi astrotsitomy sil'vieva vodoprovoda s rasprostraneniem na zadnii otdel tret'ego zheludochka.

It is presented case report of extremely rare pathology - protoplasmic astrocytoma of sylvian aqueduct involving posterior section of the third ventricle. The main principles of treatment were considered. Dynamics of neurological status was demonstrated. An effectiveness of treatment strategy was assessed.

[In-hospital outcomes of carotid endarterectomy depending on severity of contralateral lesion]. / Gospital'nye rezul'taty karotidnoi éndarteréktomii v zavisimosti ot razlichnoi vyrazhennosti kontralateral'nogo porazheniia.

AIM: To compare in-hospital outcomes of carotid endarterectomy (CEE) in patients with different lesion of contralateral internal carotid artery (ICA). MATERIAL AND METHODS: There were 730 CEE procedures in patients with bilateral ICA lesion for the period 2011-2016. All patients were divided into 4 groups depending on contralateral ICA stenosis grade: group 1 - stenosis up to 60% (42.6%, n=311); group 2 - 60-90% (18.7%, n=137); group 3 - 90-99% (25.9%, n=189); group 4 - occlusion (12.7%, n=93). Endpoints were unfavorable cardiovascular events including death, myocardial infarction (MI), stroke/TIA, significant hemorrhage by BARC scale (Bleeding Academic Research Consortium). RESULTS: In-hospital mortality and incidence of MI, stroke/TIA were similar in all groups. However, there were no cardiovascular complications in patients with critical contralateral stenosis or occlusion. Bleeding followed by redo surgery was the most frequent complication. Overall incidence of adverse cardiovascular events did not exceed 1.23%. CONCLUSION: There was no correlation between contralateral ICA stenosis and incidence of in-hospital adverse events including death, MI, stroke/TIA. Currently, technique of CEE is well developed that is associated with low incidence of postoperative complications.

[Carotid endarterectomy: three-year results of follow up within the framework of a single-centre register]. / Karotidnaia éndarteréktomiia: trekhletnie rezul'taty nabliudeniia v ramkakh odnotsentrovogo registra.

The purpose of the study was to determine the incidence rate and structure of cardiovascular complications in patients presenting with lesions of the carotid arteries and multifocal atherosclerosis, having endured carotid endarterectomy (CEA), during a three-year period within the framework of a single-centre register. The study included a total of 1,035 patients subjected to CEA over the period from 2011 to 2016. The duration of the long-term follow up averagely amounted to 42.4±18.6 months. The outcome measures assessed were as follows: death, myocardial infarction (MI), acute cerebral circulation impairment (transitory ischaemic attack) [ACCI (TIA)], clinically significant haemorrhage according to the BARC scale, unplanned repeat revascularization. In the remote period of follow up, the mortality rate did not exceed 2.3%. Of the unfavourable outcomes, most frequently observed turned out to be ACCI (TIA), with less often observed being MI. Two times a year, all patients underwent duplex scanning of the carotid arteries, whose findings revealed haemodynamically significant restenosis in 3.28% of cases. The average period of formation of restenosis amounted to 14.0±3.1 months after the operation. Three patients underwent repeat CEA and a further 16 patients endured stenting of the internal carotid artery (with 2 patients having developed intraoperative TIA). In the remote period, no cases of secondary restenosis were revealed this group of patients. It was determined that restenosis more often developed in patients having sustained classical.

Endothelialization of Polycaprolactone Vascular Graft under the Action of Locally Applied Vascular Endothelial Growth Factor.

We have previously developed a polycaprolactone (PCL) vascular graft with incorporated vascular endothelial growth factor (VEGF). Functioning of the PCL/VEGF graft in rat circulatory system over 1, 3 and 6 months after implantation into abdominal aorta was tested. Graft patency and formation of vascular wall elements were assessed histologically and by immunofluorescence staining for von Willebrand factor, CD31, CD34, and collagens I and IV and DAPI staining. Local application of VEGF promoted endothelialization and improved patency of the graft. The wall of the PCL/VEGF graft underwent remodeling due to active cellular infiltration and the extracellular matrix deposition.

[Choice of surgical tactics in patients with acute cholecystitis complicated by cholelithiasis]. / Vybor taktiki khirurgicheskogo lecheniia bol'nykh s ostrym kholetsistitom, oslozhnennym kholedokholitiazom.

PURPOSE OF THE STUDY: Comparison of the methods of surgical treatment of cholelithiasis. MATERIAL AND METHODS: The work is based on the experience of treating 139 patients with acute cholecystitis complicated by choledocholithiasis from 2008 to 2016, who were on treatment of the department of acute surgical diseases of the liver and pancreas, N.V. Sklifosovsky. RESULTS: The use of percutaneous drainage of the gallbladder in an acute period can reduce complications and reduce the number of urgent video-laparoscopic cholecystectomies to 1%.

Solar energy converters based on multi-junction photoemission solar cells.

Multi-junction solar cells with multiple p-n junctions made of different semiconductor materials have multiple bandgaps that allow reducing the relaxation energy loss and substantially increase the power-conversion efficiency. The choice of materials for each sub-cell is very limited due to the difficulties in extracting the current between the layers caused by the requirements for lattice- and current-matching. We propose a new vacuum multi-junction solar cell with multiple p-n junctions separated by vacuum gaps that allow using different semiconductor materials as cathode and anode, both activated to the state of effective negative electron affinity (NEA). In this work, the compact proximity focused vacuum tube with the GaAs(Cs,O) photocathode and AlGaAs/GaAs-(Cs,O) anode with GaAs quantum wells (QWs) is used as a prototype of a vacuum single-junction solar cell. The photodiode with the p-AlGaAs/GaAs anode showed the spectral power-conversion efficiency of about 1% at V bias = 0 in transmission and reflection modes, while, at V bias = 0.5 V, the efficiency increased up to 10%. In terms of energy conservation, we found the condition at which the energy cathode-to-anode transition was close to 1. Considering only the energy conservation part, the NEA-cell power-conversion efficiency can rich a quantum yield value which is measured up to more than 50%.

[Combination therapy for benign prostatic hyperplasia in the light of clinical guidelines].

The article reviews clinical trials on the effectiveness of combination therapy with 5-reductase inhibitors and -blockers in men with benign prostatic hyperplasia (BPH). These trials have demonstrated a significant improvement in the symptoms and quality of life in this group of patients. The authors outline main strategies offered by the Russian clinical guidelines for BPH patients.

[Clinical diagnosis and prognosis of pulmonary thromboembolism].

Pulmonary thromboembolism (PTE) is a nosological entity that complicates the course of many diseases. This circumstance determines difficulties in the diagnosis and determination of further patient management tactics. Bolus-enhanced computed tomography of pulmonary arteries, a method having high resolution and high accuracy, is presently accepted to be the gold standard to verify the diagnosis. At the same time this radiocontrast study cannot be used as a screening tool by economic and other reasoning, which determines the importance of the clinical diagnosis of the disease. This review considers different approaches to diagnosing PTE and a base of elaborated clinical algorithms and comparatively assesses empirical and scoring systems for the diagnosis and prediction of a disease course characterized by the rapidness and unpredictability of an outcome even in correctly made diagnosis.

[How to validate the symptoms of pulmonary thromboembolism: how diagnostic scales help].

AIM: To detect the most important clinical symptoms suggesting pulmonary thromboembolism (PTE) and to determine the diagnostic value of the scales used to estimate the likelihood of its occurrence. MATERIALS AND METHODS: The prospective study included 130 patients admitted to hospital with a diagnosis of PTE and a referral for a surgery clinic. Scores of the likelihood of PTE were estimated using the Canada and Geneva scales in all the patients on admission. RESULTS: In all the patients with suspected PTE, the Canadian and revised Geneva scores averaged 4.2 +/- 0.48 and 6.21 +/- 0.5, respectively. These scores correspond to the intermediate clinical probability of PTE. In 96 patients whose diagnosis was verified by instrumental studies, the Canadian and Geneva scores were 4.41 +/- 0.57 and 6.17 +/- 0.63, respectively, which was also consistent with the intermediate clinical probability of PTE. In 34 patients, whose diagnosis of PTE was ruled out, the average scores did not virtually differ from those in the patients with the verified diagnosis and were 6.14 +/- 1.3 and 4.18 +/- 0.87, respectively. The area under characteristic curve for the Canadian scale was 0.428 and that for the Geneva scale was 0.512. With the use of a two-level interpretation system, a total of more than 6 Canadian scores and 10 Geneva scores suggested that there was a high probability of PTE. CONCLUSION: The investigation indicated the low value of integral systems for estimating the likelihood of PTE in the total population of patients with this disease. The authors recommend the two-level interpretation system, in which a total of more than 6 Canadian scores and 10 Geneva scores were identified with a high probability (up to 80%) of PTE.

[Emergency fiberoptic bronchoscopy for diagnostics and treatment of lung atelectasis].

The article deals with results of fiberoptic bronchoscopy using during treating of patients suffering atelectasis. According to the research atelectasis is likely to advance in the first three days after serious patients have been admitted to the intensive therapy unit or after operative treatment. Left-sided atelectasis is half as widespread again the right-sided one. The research highlights the effectiveness of atelectasis X-ray diagnosis. Fiberoptic bronchoscopy in almost all the cases allowed diagnosing the degree of tracheobronchial tree obstruction and its causes. Single suction fiberoptic bronchoscopy leads to normalization and encouraged positive dynamics in 76% of all the cases (57 patients). Repeated endoscopic sanation in the first two days was necessary for 25 patients (25.3%) with unresolved or reoccurring atelectasis. The effectiveness of second research was to 84%. It's important to add that mostly patients with serious chest injury were subjected to unresolved or reoccurring atelectasis. And mainly in these cases blood was seen through the tracheobronchial tree lumen.

[Effectiveness of panzytrat--modern physiological enzyme preparation in complex therapy of pancreatic exocrine secretory insufficiency in cholelithiasis].

In the article the analysis of the survey with 102 patients with gallstone disease involved, 68 of whom underwent cholecystectomy and 34 were treated conservatively, is made. The content of fecal elastase 1 in stool was estimated for diagnostics of exocrine enzyme insufficiency of pancreas by immune-enzyme analysis. It was stated that 90% of patients possess secondary exocrine insufficiency of pancreas in case of gallstone disease. It is the result of complex metabolic liver abnormalities, portal and mesenterial haemodynamics, dysbiosis of large intestine which are the components of a syndrom of maldigestion and appear during gallstone disease progressing long time before hospitalization. Cholecystectomy doesn't eliminate enzyme insufficiency of pancreas. The effectiveness of using new physiological enzymatic drug Panzytrat in a complex therapy of a syndrom of maldigestion in case of gallstone disease is shown.

[Preparation of biodegradable porous films for use as wound coverings].

We studied the preparation of polymeric films formed from solutions of poly-3-hydroxybutyrate and poly-epsilon-caprolactone in chloroform and methylene chloride. A morphological study of film chips (electron microscopy) showed that solvent evaporation results in the formation of a heterogeneous structure with interpenetrating pores (1-20 microm). We proposed a new method for introducing the proteolytic enzyme and the aminopolysaccharide chitosan into the composition of polyester films. Composite films possessed necrolytic activity and were characterized by increased hydrophilicity. Properties of enzyme-containing films from a mixture of polymers (proteolytic activity, porous structure, and increased hydrophilicity) account for their use in the preparation of biodegradable wound coverings.