196 research outputs found

    (23)Na magnetic resonance imaging of the lower leg of acute heart failure patients during diuretic treatment

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    OBJECTIVE: Na+ can be stored in muscle and skin without commensurate water accumulation. The aim of this study was to assess Na+ and H2O in muscle and skin with MRI in acute heart failure patients before and after diuretic treatment and in a healthy cohort. METHODS: Nine patients (mean age 78 years; range 58-87) and nine age and gender-matched controls were studied. They underwent 23Na/1H-MRI at the calf with a custom-made knee coil. Patients were studied before and after diuretic therapy. 23Na-MRI gray-scale measurements of Na+-phantoms served to quantify Na+-concentrations. A fat-suppressed inversion recovery sequence was used to quantify H2O content. RESULTS: Plasma Na+-levels did not change during therapy. Mean Na+-concentrations in muscle and skin decreased after furosemide therapy (before therapy: 30.7+/-6.4 and 43.5+/-14.5 mmol/L; after therapy: 24.2+/-6.1 and 32.2+/-12.0 mmol/L; p<0.05 and p<0.01). Water content measurements did not differ significantly before and after furosemide therapy in muscle (p = 0.17) and only tended to be reduced in skin (p = 0.06). Na+-concentrations in calf muscle and skin of patients before and after diuretic therapy were significantly higher than in healthy subjects (18.3+/-2.5 and 21.1+/-2.3 mmol/L). CONCLUSIONS: 23Na-MRI shows accumulation of Na+ in muscle and skin in patients with acute heart failure. Diuretic treatment can mobilize this Na+-deposition; however, contrary to expectations, water and Na+-mobilization are poorly correlated

    Independent work of students as a means of optimizing the learning process of students of the non-linguistic institutes

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    The notion "self-study" is carried out from methods of teaching foreign languages, Russian language and physiology point of view in the article. The main principles of such education are considered. The author focuses on the advantages or positive things of the application of independent learning activities and considers other methods of such education in works of Russian and foreign scientists. The purpose of the work - to establish the significance of self-study application of students of nonlinguistic high school, on the example of learning English and Russian languages, where the language is a major incentive to disclose the identity of the student.Статья раскрывает понятие "самостоятельная работа" с точки зрения методики обучения иностранным языкам, русскому языку и психологии. Указываются основные принципы такого обучения. Основное внимание в работе автор акцентирует на достоинствах применения самостоятельной учебной деятельности и рассматривает иные методы такого обучения в трудах отечественных и зарубежных ученых. Цель работы - определение значимости применения самостоятельной работы студентов неязыкового вуза, на примере обучения английскому и русскому языкам, где язык выступает главным стимулом раскрытия личности студента

    3T vs. 7T fMRI: capturing early human memory consolidation after motor task utilizing the observed higher functional specificity of 7T

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    ObjectiveFunctional magnetic resonance imaging (fMRI) visualizes brain structures at increasingly higher resolution and better signal-to-noise ratio (SNR) as field strength increases. Yet, mapping the blood oxygen level dependent (BOLD) response to distinct neuronal processes continues to be challenging. Here, we investigated the characteristics of 7 T-fMRI compared to 3 T-fMRI in the human brain beyond the effect of increased SNR and verified the benefits of 7 T-fMRI in the detection of tiny, highly specific modulations of functional connectivity in the resting state following a motor task.Methods18 healthy volunteers underwent two resting state and a stimulus driven measurement using a finger tapping motor task at 3 and 7 T, respectively. The SNR for each field strength was adjusted by targeted voxel size variation to minimize the effect of SNR on the field strength specific outcome. Spatial and temporal characteristics of resting state ICA, network graphs, and motor task related activated areas were compared. Finally, a graph theoretical approach was used to detect resting state modulation subsequent to a simple motor task.ResultsSpatial extensions of resting state ICA and motor task related activated areas were consistent between field strengths, but temporal characteristics varied, indicating that 7 T achieved a higher functional specificity of the BOLD response than 3 T-fMRI. Following the motor task, only 7 T-fMRI enabled the detection of highly specific connectivity modulations representing an “offline replay” of previous motor activation. Modulated connections of the motor cortex were directly linked to brain regions associated with memory consolidation.ConclusionThese findings reveal how memory processing is initiated even after simple motor tasks, and that it begins earlier than previously shown. Thus, the superior capability of 7 T-fMRI to detect subtle functional dynamics promises to improve diagnostics and therapeutic assessment of neurological diseases

    Reduction of tissue Na(+) accumulation after renal transplantation

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    INTRODUCTION: Chronic kidney disease (CKD) engenders salt-sensitive hypertension. Whether or not tissue Na(+) accumulation is increased in CKD patients remains uncertain. How tissue Na(+) is affected after renal transplantation has not been assessed. METHODS: We measured tissue Na(+) amount in 31 CKD patients (stage 5) and prospectively evaluated tissue Na(+) content at 3 and 6 months, following living-donor kidney transplantation. Additionally, pre- and post-transplantation data were compared to 31 age- and sex-matched control subjects. (23)Na–magnetic resonance imaging ((23)Na-MRI) was used to quantify muscle and skin Na(+) of the lower leg and water distribution was assessed by bioimpedance spectroscopy. RESULTS: Compared to control subjects, CKD patients showed increased muscle (20.7 ± 5.0 vs. 15.5 ± 1.8 arbitrary units [a.u.], P < 0.001) and skin Na+ content (21.4 ± 7.7 vs. 15.0 ± 2.3 a.u., P < 0.001), whereas plasma Na(+) concentration did not differ between groups. Restoration of kidney function by successful renal transplantation was accompanied by mobilization of tissue Na(+) from muscle (20.7 ± 5.0 vs. 16.8 ± 2.8 a.u., P < 0.001) and skin tissue (21.4 ± 7.7 vs. 16.8 ± 5.2 a.u., P < 0.001). The reduction of tissue Na(+) after transplantation was associated with improved renal function, normalization of blood pressure as well as an increase in lymphatic growth-factor concentration (vascular endothelial growth factor C [VEGF-C] 4.5 ± 1.8 vs. 6.7 ± 2.7 ng/ml, P < 0.01). CONCLUSIONS: Tissue Na+ accumulation in predialysis patients with CKD was almost completely reversed to the level of healthy controls after successful kidney transplantation

    Germany's journey toward 14 Tesla human magnetic resonance

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    Multiple sites within Germany operate human MRI systems with magnetic fields either at 7 Tesla or 9.4 Tesla. In 2013, these sites formed a network to facilitate and harmonize the research being conducted at the different sites and make this technology available to a larger community of researchers and clinicians not only within Germany, but also worldwide. The German Ultrahigh Field Imaging (GUFI) network has defined a strategic goal to establish a 14 Tesla whole-body human MRI system as a national research resource in Germany as the next progression in magnetic field strength. This paper summarizes the history of this initiative, the current status, the motivation for pursuing MR imaging and spectroscopy at such a high magnetic field strength, and the technical and funding challenges involved. It focuses on the scientific and science policy process from the perspective in Germany, and is not intended to be a comprehensive systematic review of the benefits and technical challenges of higher field strengths

    Röntgen-Thorax im Skills Lab: Vom Hörsaal in den Dienst

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