Effect of transition metal cations on the local structure and lithium transport in disordered rock-salt oxides.

Lithium-excess oxides Li1.2Ti0.4Mn0.4O2 and Li1.3Nb0.3Mn0.4O2 with a disordered rock-salt structure and Mn3+/Mn4+ as a redox couple were compared to analyze the effect of different d0 metal ions on the local structure and Li+ ion migration. These cathode materials were obtained by mechanochemically assisted solid-state synthesis. Using XRD, 7Li NMR and EPR spectroscopy and transmission electron microscopy it was shown that the Mn ions are prone to form clusters, while d0 metal ions are evenly distributed in the crystal lattice. The presence of Nb5+ ions contributes to the formation of noticeably larger Mn clusters and larger gaps in the Li+ migration maps as compared to Ti4+. These results were confirmed by the geometrical-topological method, BVSE simulation and DFT calculations, and are in good agreement with the Li diffusion coefficient determined by GITT, which is 1.5 orders of magnitude higher in Li1.2Ti0.4Mn0.4O2 than that in Li1.3Nb0.3Mn0.4O2.

Crystal structure and migration paths of alkaline ions in NaVPO4F.

A sample with a nominal composition 'NaVPO4F' is prepared by mechanochemically assisted solid-state synthesis using quenching. A detailed study of its crystal and local structure is conducted by means of XRD and FTIR and solid-state 31P NMR spectroscopies in comparison with Na3V2(PO4)2F3. It is shown that the as-prepared 'NaVPO4F' has a multiphase composition, including NaVPO4F as the main phase and Na3V2(PO4)2F3 and Na2.57V4P4O17F as the side products. The crystal structure of NaVPO4F is described in the monoclinic C2/c space group. It is characterized by negligible V3+/V4+ oxidation with the corresponding F-/O2- substitution and the presence of structural disordering. Using the Voronoi-Dirichlet partition (VDP) method, the Na+ and Li+ migration pathways in Tavorite-like NaVPO4F and closely related LiVPO4F (with the triclinic structure, P1[combining macron] S.G.) are analyzed. While the Na+ migration is suppressed in both cases, the Na+/Li+ ion exchange in NaVPO4F with the formation of monoclinic LiVPO4F could occur, but is difficult due to the sodium immobility rather than the instability of the lithium derivatives as was concluded from the DFT calculations.

[B vitamins and diseases of the peripheral nervous system]. / Vitaminy gruppy B i zabolevaniya perifericheskoi nervnoi sistemy.

Various diseases of the peripheral nervous system are associated with metabolic disorders of B vitamins. A lack of neurotropic vitamins, which began in the early stages of the development of a bacterial disease, led to its more rapid development. The article analyzes data on B vitamin deficiency in the pathogenesis of the most dangerous diseases of the peripheral nervous system. Information is provided about the dangers of the clinical use of the drug Combilipen for the treatment of such patients.

[Risk factors and adherence to treatment of patients with cerebrovascular diseases]. / Faktory riska i priverzhennost' lecheniyu patsientov s tserebrovaskulyarnymi zabolevaniyami.

OBJECTIVE: To assess the representation of risk factors and treatment adherence in patients with cerebrovascular diseases. MATERIAL AND METHODS: A single-stage cross-sectional non-comparable study was conducted, which included 492 patients, of whom 133 had an ischemic stroke/transient ischemic attack (main group, MG), 344 had chronic cerebrovascular pathology (comparison group, CG). The representation of risk factors, the state of cognitive functions, the severity of anxiety and depression were evaluated. RESULTS: MG respondents visit specialized specialists more often than CG (p<0.001), are more committed to taking antiplatelet agents (p<0.003), statins (p<0.005), antihypertensive drugs (p<0.005). Regular intake of antithrombotic drugs was associated with the history of ischemic stroke (r=0.483; p<0.01), type 2 diabetes (r=0.637; p<0.011), atrial fibrillation (r=0.481; p<0.001), living in a family (r=0.493; p<0.03). An inverse correlation was established between the systematic intake of antiplatelet drugs and the age of the respondents (r=-0.637; p<0.002), cognitive impairment (r=-0.433; p<0.05), the history of the gastrointestinal tract diseases (gastric ulcer and duodenal ulcer) (r=-0.563; p<0.001). Irregular medication intake was observed in patients aged over 60 years compared with younger (17.3% and 6.4%, respectively, p=0.001), patients living in a family compared with single (85.6% and 65.1%, p=0.032). The history of ischemic stroke or myocardial infarction is associated with increased adherence to regular medication. CONCLUSION: The study of risk factors and the assessment of treatment adherence can ensure the formation of an effective strategy for primary and secondary prevention of cerebrovascular diseases.

[Dynamic of cerebrovascular disorders in patients with carotid stenosis]. / Techenie tserebrovaskuliarnoi patologii u bol'nykh so stenoziruiushchim porazheniem sonnykh arterii.

AIM: To study the state of cerebral hemodynamics and platelet hemostasis in patients with carotid stenosis (CS). MATERIAL AND METHODS: The prospective study included 123 patients with atherosclerotic CS. The 1st group included 53 patients (mean age 52±12.5 yrs) who underwent carotid endarterectomy (CEA); the 2nd group - 70 patients who were treated conservatively (mean age 58.5±15.9 yrs). The state of blood flow through the main arteries of the head (Doppler flowmetry), platelet aggregation induced by adrenaline, the frequency of acute cardiovascular events that occurred during 12 months were evaluated. RESULTS AND CONCLUSION: The severity of neurological deficits and cognitive impairment increased with increasing of the degree of CS. CEA leads to an improvement of cerebral hemodynamics and stabilization of cognitive functions. The adverse course of the disease occurred in 23.6% of patients (stroke/heart attack during the year in 5.7%, progression of cerebral ischemia in 20%, restenosis within 5 years after CEA in 15%). Hyperaggregation of platelets induced by ADP and epinephrine and decreased aggregation of platelets induced by collagen in patients receiving ASA were identified in 53% of the operated and in 60% of non-operated patients. The use of combined antiplatelet therapy normalize the platelet hemostasis and reduce the frequency of acute cardiovascular events.

Regulation of the catalytic activity and oligomeric composition of enzymes in reversed micelles of surfactants in organic solvents.

The phenomenon of regulation of the catalytic activity of enzymes via changing their oligomeric composition in the system of reversed micelles of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) in octane was studied using alpha-chymotrypsin (CT) from bovine brain and alkaline phosphatase (AP) from calf intestinal mucosa. The dependences of the enzyme catalytic activity on the AOT hydration degree (Wo = [H2O]/[AOT]), the parameter determining the radius (rc) of the inner cavity of micelles, usually represent the bell-shaped curves. The maximal catalytic activity is observed at such Wo when rc is equal to the size of the enzyme molecule. The position of this maximum strictly correlates with the enzyme oligomeric composition. Thus, in the case of CT this is observed at Wo = 12 when rc is equal to the radius (rp) of the CT globule. In the case of artificially produced conjugate containing six cross-linked CT molecules, this is observed at Wo = 43 when rc is equal to the radius of the sphere surrounding the absolute octahedron composed of six CT globules. The dependence of the catalytic activity of AP on Wo represents a curve with two maxima that are observed when rc is equal to rp of either AP monomer (Wo = 17) or AP dimer (Wo = 25). Ultracentrifugation experiments revealed that variation of Wo causes a change in the oligomeric composition of AP - its transition from monomeric (Wo less than 20) to dimeric form (Wo greater than 20). Hence, the observed maxima correspond to functioning of different oligomeric forms of AP.

[Status of central and cerebral hemodynamics in patients with occlusive lesions of major arteries of the head in the acute period of ischemic stroke]. / Sostoianie tsentral'noi i tserebral'noi gemodinamiki u bol'nykh s okkliuziruiushchimi porazheniiami magistral'nykh arterii golovy v ostrom periode ishemicheskogo insul'ta.

A study was made of the central and cerebral hemodynamics in 65 patients with occlusive lesions of the main arteries of the head in the acute period of ischemic brain stroke (on days 1, 7 and 21). Ultrasound dopplerography of the extracranial part of the main arteries of the head and unidimensional echocardiography were employed. Analysis of the linear velocity of the blood flow in the internal carotid and vertebral arteries, of their diameter and volumetric blood flow, and of the central hemodynamics allowed a conclusion that the presence of cardial pathology in ischemic brain stroke promotes a progressive decrease of contractile and pump function of the left ventricular myocardium toward the end of the acute period of ischemic brain stroke.

[Ultrasonic diagnosis of patients with circulatory encephalopathy]. / Ul'trazvukovaia diagnostika u bol'nykh s distsirkuliatornoi éntsefalopatiei.

The paper describes the results of examining intracerebral blood flow in patient with different stages of dyscirculatory encephalopathies. Transcranial Doppler was applied. Ultrasound examination of the great arteries of the head was made by determining the linear and volumetric velocities of blood flow. Progressive cerebral atherosclerosis was found to result in an earlier decrease in cerebrovascular blood flow.

[Peculiarities of cerebral hemodynamics in angiogenic cochlear vestibulopathy and lipid distress-syndrome (communication 1: ultrasonographic diagnosis]. / Osobennosti gemodinamiki golovnogo mozga pri angiogennykh kokhleovestibulopatiiakh i lipidnom distress-sindrome (soobshchenie 1: ul'trazvukovaia diagnostika]

Arterial and venous blood supply to the brain was studied in 221 patients with angiogenic cochleovestibulopathy and lipid distress-syndrome. Hemodynamic features are described with consideration of cochleovestibular problems and their causes. Alterations in elasticity of arterial wall reflecting systemic processes in atherosclerosis are characterized.

[Combined thoracoscopy in thoracoabdominal wounds using ultrasound, the CO2 laser and the plasma jet]. / Kombinirovannaia torakoskopiia pri torakoabdominal'nykh raneniiakh s ispol'zovaniem ul'trazvuka, CO2 lazers i strui plazmy.

Under analysis is an experience with treatment of 178 patients with thoracoabdominal wounds. The authors have developed a rational curative methods and original thoracoscopic techniques, which allowed to considerably reduce the amount of thoracotomies. Thoracoscopy was performed in 157 (88%) of 178 patients. Indications for thoracotomy were established in 7 patients, in 19 patients only drainage of the pleural cavity was made. Curative thoracoscopy was used in 131 patients, in 60 of them ultrasonic glue hermetization of the lung wound was made, 36 patients had laser photocoagulation of the lung wound, 21 patients had plasma coagulation of pleuro-pulmonary defects, in 14 patients--coagulated hemothorax was removed. Clinical effectiveness of thoracoscopic techniques was more than 90%. Thoracotomy was performed in 28 (15%) patients, in 11 patients it was supplemented with diaphragmotomy. Laparotomy was performed in 167 patients. Lethality was 6.8%.

[Demographic characteristics of risk factors of ischemic stroke in the Dagestan Republic]. / Demograficheskie osobennosti struktury faktorov riska razvitiia ishemicheskogo insul'ta v Respublike Dagestan.

Objective. To study risk factors for ischemic stroke (II) in patients from the Dagestan Republic. Material and methods. We studied 135 patients (57 women and 78 men) with II, aged from 52-82 years (mean age 68.22±8.25 years). Results and conclusion. The main risk factors for II were: arterial hypertension and cerebral atherosclerosis; 58.5% patients had stenocardia, 34.1% fibrillary oscillation, 17.8% diabetes mellitus, 67.4% excessive body mass, 19.3 survived myocardial infarction and 10.4 - II, 35.6% patients smoked. Hemodynamia, dyslipidemia, distress, diabetes mellitus, myocardial infarction were more often noted in patients from flat regions, excessive body mass and smoking were risk factors for patients from sub-mountain areas and arterial hypertension, cerebral atherosclerosis, fibrillary oscillation for patients from mountain regions.

[Surgical prevention of stroke in patients with carotid stenosis]. / Khirurgicheskaia profilaktika ishemicheskogo insul'ta u bol'nykh so stenoziruiushchim porazheniem vnutrennikh sonnykh arterii

Objectives. To study the cerebral and central hemodynamics in patients with stenotic lesions of inner carotid arteries (ICA) before and after reconstructive surgery. Material and methods. Fifty-nine patients, aged from 46 to 78 years, with >50% atherosclerotic stenosis of ICA who underwent preventive carotid endarterectomy (CEAE) were examined. The isolate stenosis of ICA was identified in 13.6% of patients, concomitant lesions of brachiocephalic arteries in 86.4%. Atherosclerotic lesions of coronary arteries were found in 91.1% of patients and those of arteries of lower extremities in 45.8%. In 25.5% of patients, the heart surgery was performed before the current hospitalization. Heterogeneous atherosclerotic plaques with dense or hyperdense components were more frequents in symptomatic stenosis (63.3%). The maximal stenosis was identified in heterogeneous hyperechogenic plaques, the minimal ones in homogenous hypoechogenic plaques. Parameters of central hemodynamics were better in patients with 2nd stage of reconstructive surgeries. The emission fraction decreased proportionally to the degree of stenosis. The parameters of cerebral hemodynamics were significantly decreased in ICA stenosis and improved in the early post-surgery period. Results. CEAE promoted the improvement of cognitive functions and the recovery of motor functions. The best positive dynamics was recorded in asymptomatic ICA stenosis. Poor outcome (transitory ischemic attacks, urgent surgery, restenosis) was found in patients with low levels of central and cerebral hemodynamics 12-24 months after the discharge. Moreover, smoking and the degree of stenosis predicted poor outcome. Conclusions. Surgical treatment in combination with the complex pharmacotherapy (hypotensive drugs, antiaggregants and statins) had the maximal effect, including the remote period.

[Neuroprotective treatment with citicoline (ceraxon) in patients with ischemic stroke].

The dynamics of neurological symptoms assessed with the Scandinavian stroke scale, the Barthel index and the modified Rankin scale was studied in 89 patients with moderate ischemic stroke who received citicoline (ceraxone) intravenously and orally. The results were compared to a group of 52 age-, sex- and stroke-matched patients who did not receive citicoline. To the date of discharge from the hospital (days 21-24), the full restoration (p<0.05) was noted in patients of the main group. Efficacy of citicoline was significantly (p<0.05) higher in patients younger than 70 years and when the drug was used in the first hours of disease.

[Changes in cognitive functions in patients with occlusive lesions of brachiocephalic arteries after reconstructive surgery on carotid arteries].

Seventy-six patients after the reconstructive surgery on carotid arteries underwent neuropsychological testing with the MMSE, the FAB, the Clock Drawing Test at baseline and 8-10 days and 3 months after the surgery. Patients were stratified into 3 groups: 20 patients with predominant lesions of one internal carotid artery (group 1), 22 patients with bilateral carotid stenosis (group 2) and 34 patients with the combination of lesions of carotid and vertebrobasilar system (group 3). The association between the rate of spreading of atherosclerotic processes in cerebral vessels and cognitive disorders was shown. The positive effect of reconstructive surgery on cognitive functions of patients was confirmed.

[Patogenetic therapy of patients with diabetes mellitus type 2 and cerebral vascular insufficiency].

Effectiveness of halidor preparation was assessed in a randomized open 8-weeks study in 44 patients with diabetes mellitus type 2 and chronic cerebral blood circulation disorders. A control group included 15 patients with the same pathologies who did not receive halidor. Administration of halidor in doses 100 mg 3 times daily led to the improvement of clinical state in 32 (72,7%) patients that was confirmed by statistically better performance (p<0,05) on the neuropsychological tests: MMSE by 14,7%, clock-drawing test by 16,8%, the Schult test by 23,5%. The blood flow in middle and posterior cerebral arteries was increased by 21 and 23%, respectively (p<0,05), and the vascular tonus was reduced. The possibility of halidor administration to patients with diabetes mellitus with concomitant chronic cerebral blood circulation disorders is discussed.

[Phezam efficacy in patients with chronic cerebral ischemic disease].

The efficacy of combined medication which comprised compounds with nootropic (piracetam) and vasoactive (cinnarisin) effects, was studied in patients with cerebral blood flow insufficiency. The main inclusion criterion was a diagnosis of chronic brain ischemia (CI). The study consisted of two stages: (1) a randomized comparative trial in neurological clinic (60 patients) and (2) estimation of the drug efficacy in routine practice (60 patients). The clinical examination was accompanied by neuropsychological tasks, kinetic tests and ultrasound investigation of brain vessels. At the first stage, a positive neurological and neuropsychological dynamics was found after 8 weeks of phezam treatment. Also a statistically significant positive dynamics was observed for a number of blood flow velocity parameters in the middle brain artery. In routine medical practice, a positive effect of phezam was seen after 2 months of the treatment for all but CI main symptoms and confirmed by the data of kinetic investigation. The patients reported good tolerability and convenience of the drug intake (one capsule instead of two tablets of nootropic and vasoactive drugs).

[The cerebral and central hemodynamics of patients with vertebrobasilar stroke]. / Tserebral'naia i tsentral'naia hemodinamika u bol'nykh vertebral'no-baziliarnym insul'tom.

Cerebral and central hemodynamics were studied in 45 patients acutely affected with vertebrobasilar apoplexy. Noninvasive methods-ultrasonic dopplerography of the extracranial carotid and vertebral arteries, unidirectional echocardiography were employed on post-apoplectic days 1, 7 and 21. The same examinations were performed in two groups of control subjects: healthy persons and patients with dyscirculatory encephalopathy degree I and II. The comparison of relevant data elucidated regularities of interaction existing in the changes of cerebral and central hemodynamics in patients with vertebrobasilar apoplexy of moderate severity. Prognostic significance of the findings is characterized.