173 research outputs found

    HISTORIOGRAPHY OF SCIENTIFIC COMMUNICATIONS IN THE FIELD OF MEMORY AND BLOOD-BRAIN BARRIER

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    A scientometric study after author's own methods (Tomov, 1986 and 1998) of the publication output in the field ofmemory and blood-brain barrier in MEDLINE on CD-ROM (EBSCO Publ., USA) data base for 1965-2000 was carried out. On this interdisciplinary topic, a total of 126 articles in seven languages, mainly in English, had been published in a total of 93 journals from 21 countries. In 37 review articles there were 5289 references (at an average of 143 references per paper). Authors' institutions belonged to 18 mono- and 7 interdisciplinary thematic profiles while the journals could be assigned to 17 mono- and 8 interdisciplinary profiles. Some 39 journals from 12 countries containing 57 articles belonged to the generalized profile of neurosciences. The authors from the USA had published 37 papers in 30 American journals but 16 ones in 10 journals from 5 countries. Aa a whole, 67 papers had been published in domestic journals but 59 ones in foreign journals. Eight articles by authors from 6 countries had been published in 7 "international" journals from 5 countries. The computerized historiography of science could be successfully applied for scientometric purposes and for perfection of science policy and management at any levels in small countries like Bulgaria

    Effect of hypohydration on peripheral and corticospinal excitability and voluntary activation

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    Open Access journalPMCID: PMC3788753Copyright: © 2013 Bowtell et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.We investigated whether altered peripheral and/or corticospinal excitatory output and voluntary activation are implicated in hypohydration-induced reductions in muscle isometric and isokinetic (90°.s(-1)) strength. Nine male athletes completed two trials (hypohydrated, euhydrated) comprising 90 min cycling at 40°C, with body weight losses replaced in euhydrated trial. Peripheral nerve and transcranial magnetic stimulations were applied during voluntary contractions pre- and 40 min post-exercise to quantify voluntary activation and peripheral (M-wave) and corticospinal (motor evoked potential) evoked responses in m. vastus medialis. Both maximum isometric (-15.3±3.1 vs -5.4±3.5%) and isokinetic eccentric (-24.8±4.6 vs -7.3±7.2%) torque decreased to a greater extent in hypohydrated than euhydrated trials (p<0.05). Half relaxation time of the twitch evoked by peripheral nerve stimulation during maximal contractions increased after exercise in the hypohydrated (21.8±9.3%) but stayed constant in the euhydrated (1.6±10.7%; p = 0.017) condition. M-wave amplitude during maximum voluntary contraction increased after exercise in the heat in hypohydrated (10.7±18.0%) but decreased in euhydrated condition (-17.4±16.9%; p = 0.067). Neither peripheral nor cortical voluntary activation were significantly different between conditions. Motor evoked potential amplitude increased similarly in both conditions (hypohydrated: 25.7±28.5%; euhydrated: 52.9±33.5%) and was accompanied by lengthening of the cortical silent period in euhydrated but not hypohydrated condition (p = 0.019). Different neural strategies seem to be adopted to regulate neural drive in the two conditions, with increases in inhibitory input of either intracortical or corticospinal origin during the euhydrated trial. Such changes were absent in the hypohydrated condition, yet voluntary activation was similar to the euhydrated condition, perhaps due to smaller increases in excitatory drive rather than increased inhibition. Despite this maximal isometric and eccentric strength were impaired in the hypohydrated condition. The increase in peripheral muscle excitability evident in the hypohydrated condition was not sufficient to preserve performance in the face of reduced muscle contractility or impaired excitation-contraction coupling

    VIRTUAL LIBRARY OF THE MEDICAL UNIVERSITY OF VARNA - IDEOGENESIS, PRESENCE, AND FUTURE

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    The Library and Information Service at Prof. Paraskev Stoyanov Medical University of Varna has passed through several stages in its historical development. They results obtained are related with the timely recognition of the necessity of introduction in the Library of the new information technologies. Thus the library staff faces the requirements of the information society of the new millennium. The enthusiastic efforts of the governing body of the library are directed to the permanent improvement of information retrieval in the university medical libraries in Bulgaria, the coordination of their computerization, and the creative enrichment of the forms and methods of information service of the teachers and students. Modern audiovisual means are used along with interactive user's education for independent search in the foreign databases in the library and through Internet. The electronic-mail connections help delivering the documents to the readers in the university departments and clinics after scanning the paper information sources in our library and in other libraries. The electronic library catalogue of books is already accessible through Internet. Our idea of a modern virtual library opened to the future and preserving the rich traditions of our University becomes step-by-step a fascinating reality

    GEANT4 simulation of the moderating neutrons spectrum

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    The probability and intensity of nuclear reactions involving neutrons are characterized by the corresponding reaction cross-sections which are known to depend strongly on the incident neutron energy. In real applications the neutrons are seldom or never monoenergetic, and are usually characterized by certain continuous energy spectrum. The detailed knowledge of the neutron spectrum is crucial for numerous applications such as the nuclear reactor operation, the traveling wave reactor (TWR) development, including the search of the neutron energy ranges suitable for the wave nuclear burning, the search and prediction of the so-called "blowup modes" in neutron-multiplying media, the verification of neutron moderation theories and so on. In this paper we describe a method of GEANT4-based Monte Carlo calculation of the neutron spectrum evolution as well as the steady-state neutron spectrum in a system containing a persistent neutron source.Comment: 18 pages, 10 figure

    Lower body acceleration and muscular responses to rotational and vertical whole-body vibration of different frequencies and amplitudes

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    This is the final version. Available on open access from SAGE Publications via the DOI in this recordThe aim of this study was to characterise acceleration transmission and neuromuscular responses to rotational (RV) and vertical (VV) vibration of different frequencies and amplitudes. Methods - 12 healthy males completed 2 experimental trials (RV vs. VV) during which vibration was delivered during either squatting (30°; RV vs. VV) or standing (RV only) with 20, 25, 30 Hz, at 1.5 and 3.0 mm peak-to-peak amplitude. Vibration-induced accelerations were assessed with triaxial accelerometers mounted on the platform and bony landmarks at ankle, knee, and lumbar spine. Results At all frequency/amplitude combinations, accelerations at the ankle were greater during RV (all p < 0.03) with the greatest difference observed at 30 Hz 1.5 mm. Transmission of RV was also influenced by body posture (standing vs. squatting, p < 0.03). Irrespective of vibration type vibration transmission to all skeletal sites was generally greater at higher amplitudes but not at higher frequencies, especially above the ankle joint. Acceleration at the lumbar spine increased with greater vibration amplitude but not frequency and was highest with RV during standing. Conclusions/Implications - The transmission of vibration during WBV is dependent on intensity and direction of vibration as well as body posture. For targeted mechanical loading at the lumbar spine, RV of higher amplitude and lower frequency vibration while standing is recommended. These results will assist with the prescription of WBV to achieve desired levels of mechanical loading at specific sites in the human body.London South Bank UniversityAge U

    Muscle metabolic and neuromuscular determinants of fatigue during cycling in different exercise intensity domains.

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    This is the author accepted manuscript. The final version is available from American Physiological Society via the DOI in this record.The lactate or gas exchange threshold (GET) and the critical power (CP) are closely associated with human exercise performance. We tested the hypothesis that the limit of tolerance (Tlim) during cycle exercise performed within the exercise intensity domains demarcated by GET and CP is linked to discrete muscle metabolic and neuromuscular responses. Eleven males performed a ramp incremental exercise test, 4-5 severe-intensity (SEV; >CP) constant-work-rate (CWR) tests until Tlim, a heavy-intensity (HVY; GET) CWR test until Tlim, and a moderate-intensity (MOD; 0.05) muscle metabolic milieu (i.e., low pH and [PCr] and high [lactate]) was attained at Tlim (~2-14 min) for all SEV exercise bouts. The muscle metabolic perturbation was greater at Tlim following SEV compared to HVY, and also following SEV and HVY compared to MOD (all P0.05). Neural drive to the VL increased during SEV (4±4%; P0.05). During SEV and HVY, but not MOD, the rates of change in M-wave amplitude and neural drive were correlated with changes in muscle metabolic ([PCr], [lactate]) and blood ionic/acid-base status ([lactate], [K(+)]) (P<0.05). The results of this study indicate that the metabolic and neuromuscular determinants of fatigue development differ according to the intensity domain in which the exercise is performed

    Infarct size, inflammatory burden, and admission hyperglycemia in diabetic patients with acute myocardial infarction treated with SGLT2-inhibitors: a multicenter international registry

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    BACKGROUND: The inflammatory response occurring in acute myocardial infarction (AMI) has been proposed as a potential pharmacological target. Sodium-glucose co-transporter 2 inhibitors (SGLT2-I) currently receive intense clinical interest in patients with and without diabetes mellitus (DM) for their pleiotropic beneficial effects. We tested the hypothesis that SGLT2-I have anti-inflammatory effects along with glucose-lowering properties. Therefore, we investigated the link between stress hyperglycemia, inflammatory burden, and infarct size in a cohort of type 2 diabetic patients presenting with AMI treated with SGLT2-I versus other oral anti-diabetic (OAD) agents. METHODS: In this multicenter international observational registry, consecutive diabetic AMI patients undergoing percutaneous coronary intervention (PCI) between 2018 and 2021 were enrolled. Based on the presence of anti-diabetic therapy at the admission, patients were divided into those receiving SGLT2-I (SGLT-I users) versus other OAD agents (non-SGLT2-I users). The following inflammatory markers were evaluated at different time points: white-blood-cell count, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), neutrophil-to-platelet ratio (NPR), and C-reactive protein. Infarct size was assessed by echocardiography and by peak troponin levels. RESULTS: The study population consisted of 583 AMI patients (with or without ST-segment elevation): 98 SGLT2-I users and 485 non-SGLT-I users. Hyperglycemia at admission was less prevalent in the SGLT2-I group. Smaller infarct size was observed in patients treated with SGLT2-I compared to non-SGLT2-I group. On admission and at 24&nbsp;h, inflammatory indices were significantly higher in non-SGLT2-I users compared to SGLT2-I patients, with a significant increase in neutrophil levels at 24&nbsp;h. At multivariable analysis, the use of SGLT2-I was a significant predictor of reduced inflammatory response (OR 0.457, 95% CI 0.275-0.758, p = 0.002), independently of age, admission creatinine values, and admission glycemia. Conversely, peak troponin values and NSTEMI occurrence were independent predictors of a higher inflammatory status. CONCLUSIONS: Type 2 diabetic AMI patients receiving SGLT2-I exhibited significantly reduced inflammatory response and smaller infarct size compared to those receiving other OAD agents, independently of glucose-metabolic control. Our findings are hypothesis generating and provide new insights on the cardioprotective effects of SGLT2-I in the setting of coronary artery disease. TRIAL REGISTRATION: Data are part of the ongoing observational registry: SGLT2-I AMI PROTECT. CLINICALTRIALS: gov Identifier: NCT05261867

    A Dual-Beam Irradiation Facility for a Novel Hybrid Cancer Therapy

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    In this paper we present the main ideas and discuss both the feasibility and the conceptual design of a novel hybrid technique and equipment for an experimental cancer therapy based on the simultaneous and/or sequential application of two beams, namely a beam of neutrons and a CW (continuous wave) or intermittent sub-terahertz wave beam produced by a gyrotron for treatment of cancerous tumors. The main simulation tools for the development of the computer aided design (CAD) of the prospective experimental facility for clinical trials and study of such new medical technology are briefly reviewed. Some tasks for a further continuation of this feasibility analysis are formulated as well.Comment: 18 pages, 3 tables, 8 figures, 50 reference

    Outcomes in diabetic patients treated with SGLT2-Inhibitors with acute myocardial infarction undergoing PCI: The SGLT2-I AMI PROTECT Registry

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    Aims: To investigate in-hospital and long-term prognosis in T2DM patients presenting with acute myocardial infarction (AMI) treated with SGLT2-I versus other oral anti-diabetic agents (non-SGLT2-I users). Methods: In this multicenter international registry all consecutive diabetic AMI patients undergoing percutaneous coronary intervention between 2018 and 2021 were enrolled and, based on the admission anti-diabetic therapy, divided into SGLT-I users versus non-SGLT2-I users. The primary endpoint was defined as a composite of cardiovascular death, recurrent AMI, and hospitalization for HF (MACE). Secondary outcomes included i) in-hospital cardiovascular death, recurrent AMI, occurrence of arrhythmias, and contrast-induced acute kidney injury (CI-AKI); ii) long-term cardiovascular mortality, recurrent AMI, heart failure (HF) hospitalization. Results: The study population consisted of 646 AMI patients (with or without ST-segment elevation): 111 SGLT2-I users and 535 non-SGLT-I users. The use of SGLT2-I was associated with a significantly lower in-hospital cardiovascular death, arrhythmic burden, and occurrence of CI-AKI (all p &lt; 0.05). During a median follow-up of 24 ± 13 months, the primary composite endpoint, as well as cardiovascular mortality and HF hospitalization were lower for SGLT2-I users compared to non-SGLT2-I patients (p &lt; 0.04 for all). After adjusting for confounding factors, the use of SGLT2-I was identified as independent predictor of reduced MACE occurrence (HR=0.57; 95%CI:0.33–0.99; p = 0.039) and HF hospitalization (HR=0.46; 95%CI:0.21–0.98; p = 0.041). Conclusions: In T2DM AMI patients, the use of SGLT2-I was associated with a lower risk of adverse cardiovascular outcomes during index hospitalization and long-term follow-up. Our findings provide new insights into the cardioprotective effects of SGLT2-I in the setting of AMI. Registration: Data are part of the observational international registry: SGLT2-I AMI PROTECT. ClinicalTrials.gov Identifier: NCT05261867
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