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1.
Samo Lasi
Filip Szczepankiewicz Erica Dall'Armellina Arka Das Christopher Kelly Sven Plein Jürgen E. Schneider Markus Nilsson Irvin Teh 《NMR in biomedicine》2020,33(2)
Motion is a major confound in diffusion‐weighted imaging (DWI) in the body, and it is a common cause of image artefacts. The effects are particularly severe in cardiac applications, due to the nonrigid cyclical deformation of the myocardium. Spin echo‐based DWI commonly employs gradient moment‐nulling techniques to desensitise the acquisition to velocity and acceleration, ie, nulling gradient moments up to the 2nd order (M2‐nulled). However, current M2‐nulled DWI scans are limited to encode diffusion along a single direction at a time. We propose a method for designing b‐tensors of arbitrary shapes, including planar, spherical, prolate and oblate tensors, while nulling gradient moments up to the 2nd order and beyond. The design strategy comprises initialising the diffusion encoding gradients in two encoding blocks about the refocusing pulse, followed by appropriate scaling and rotation, which further enables nulling undesired effects of concomitant gradients. Proof‐of‐concept assessment of in vivo mean diffusivity (MD) was performed using linear and spherical tensor encoding (LTE and STE, respectively) in the hearts of five healthy volunteers. The results of the M2‐nulled STE showed that (a) the sequence was robust to cardiac motion, and (b) MD was higher than that acquired using standard M2‐nulled LTE, where diffusion‐weighting was applied in three orthogonal directions, which may be attributed to the presence of restricted diffusion and microscopic diffusion anisotropy. Provided adequate signal‐to‐noise ratio, STE could significantly shorten estimation of MD compared with the conventional LTE approach. Importantly, our theoretical analysis and the proposed gradient waveform design may be useful in microstructure imaging beyond diffusion tensor imaging where the effects of motion must be suppressed. 相似文献
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Resistance of pathogenic bacteria to antibiotics leads scientists to discover new antibacterial drugs. Ninety samples of wood-colonizing fungi were cultivated on agar plates, and their extracts tested for antibacterial activity using the Vibrio fischeri bioluminescence test. Two fungi species, Serpula lacrymans and Nectria vilior, were found to be a potential new source of thermostable antibiotics. Vibrio fischeri bioluminescence test was found to be a useful method for antibacterial activity screening from the samples of natural origin. 相似文献
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Shpynov SN Parola P Rudakov NV Samoĭlenko IE Tankibaev MA Tarasevich IV Raoult D Kovalev NG Chubirko MI Gavrilov AP 《Meditsinskaia parazitologiia i parazitarnye bolezni》2003,(3):20-24
R. slovaca was first detected in the ticks D. marginatus gathered in the Stavropol Territory and the Voronezh Region (European Russia). The recently discovered rickettsial genotype DnS14 was first found in the ticks D. silvarum from Buryatia and D. niveus from the Karaganda Region (Central Kazakhstan). The rickettsial genotype RpA4 was most common in the ticks of the genus Dermacentor in Russia and Central Kazakhstan. An analysis of the spread of rickettsias of the STF group shows their close ecological relation to definite types of Ixodes. The rickettsias R. slovaca and RpA4 co-exist in the ticks D. marginatus and D. reticulatus (the western part of a Dermacentor area in Eurasia) and DnS14 and R. sibirica do in D. nuttalli and D. silvarum (the eastern part of the area). D. marginatus and D. reticulatus in the areas characterized by the most specific saturation of a Dermacentor area (the south of West Siberia) are carriers and reservoir of R. sibirica. The rickettsial genotype DnS28 may be now considered to be environmentally associated with one species of ticks--D. nuttalli. At least 6 genotypes of STF rickettsias--R. sibirica, R. astrahan fever (R. conorii), R. slovaca, RpA4, DnS14, DnS28--has been currently identified in Russia and Kazakhstan. 相似文献
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Gregor Nosan Sara Bertok Samo Vesel Helger G. Yntema Darja Paro-Panjan 《Croatian medical journal》2013,54(6):574-578
Noonan syndrome is a relatively common and heterogeneous genetic disorder, including congenital heart defect in more than half of the cases. If the defect is not large, life expectancy is normal. Here we report on a case of an infant with Noonan syndrome and rapidly progressive hypertrophic cardiomyopathy with lethal outcome, in whom we identified a novel mutation in the KRAS gene. This heterozygous unclassified missense variant in exon 3: c.179G>T (p.Gly60Val) might be associated with a lethal form of Noonan syndrome. The malignant clinical course of the disease and the lethal outcome in an infant only a few months old might be connected to RAS-mitogen-activated protein kinase pathway hyperactivation, consequently promoting cell growth and proliferation, leading to rapidly progressive hypertrophic cardiomyopathy. Further biochemical and functional studies are needed to confirm this hypothesis.Noonan syndrome (NS; http://www.omim.org/entry/163950?search=163950&highlight=163950) is a relatively common genetic disorder with an incidence of 1 per 1000-2500 live births (1). Clinically it is a very heterogeneous disorder, predominantly characterized by dysmorphic facial features, congenital heart defect (CHD), post-natal short stature, webbed neck, chest deformity, cryptorchidism in men, lymphatic dysplasia, variable bleeding disorders, and intellectual disability. CHD is present in 50 to 80% of affected individuals and it is also very heterogeneous (2). Most commonly found are pulmonary valve stenosis with or without dysplastic pulmonary valve and hypertrophic cardiomyopathy. Providing the CHD is not large, life expectancy is in the normal range (3). NS and CHD are regularly connected with germline KRAS mutations. We describe a patient with NS and rapidly progressive hypertrophic cardiomyopathy with lethal outcome, in whom we identified a novel mutation in the KRAS gene. 相似文献
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The right gastroepiploic artery is most frequently used for direct myocardial revascularization. In this connection, its histological study was performed to reveal the atherosclerosis incidence in persons from different age groups who had apparent signs of coronary atherosclerosis. Twenty one arteries taken from adult cadavers at the age of 35-85 years were examined. The arteries with normal were 28.6%, those with Degree I alterations were 52.4%, those with Degree II alterations were 19%. Degrees III and IV alterations were not detected. Morphological studies indicated that hemodynamically significant right gastroepiploic artery lesions were found in 19% of cases, mainly in subjects above 60 years. The artery may be used in coronary surgery as a shunt with a good prognosis of its performance. 相似文献
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Jalie A. Tucker Jill A. Samo Colleen S. W. Rand Edward R. Woodward 《The International journal of eating disorders》1991,10(6):689-698
Bariatric surgery for extreme obesity requires eating behavior and lifestyle changes that behavioral interventions may facilitate. Surgery patients were randomly assigned to a minimal intervention control group (n = 15) or a behavioral treatment group (n = 17), who participated in monthly behavioral consultations and received biweekly weight management materials for 6 months. Interviews assessed subjects' eating behavior, psychosocial functioning, and physical status for 6 months after surgery. Both groups showed significant weight loss during the first year after surgery, but the groups did not differ significantly. Subjects did not lose additional weight by 2 years following surgery. Treatment subjects reported higher postoperative psychosocial functioning and physical activity and consumed less fat and protein than did control subjects. These findings suggest that behavioral interventions enhance postoperative adjustment in behavioral and lifestyle variables, but do not add to the substantial weight losses produced by surgery alone. 相似文献
10.
Petra Slanc Bojan Doljak Samo Kreft Mojca Lunder Damjan Janeš Borut Štrukelj 《Phytotherapy research : PTR》2009,23(6):874-877
Lipids are important components in human nutrition; however, their increased intake contributes to the development of obesity and can lead to multiple long‐term complications. Pancreatic lipase (triacylglycerol acylhydrolase, EC 3.1.1.3) is a key enzyme for the absorption of dietary triglycerides. Interference with fat hydrolysis results in the reduced utilization of ingested lipids, therefore inhibition of lipases decreases fat absorption. Extracts from 106 species of medicinal plants, vegetables and fruits were screened for potential lipase inhibitory activity. p‐Nitrophenylpalmitate and 5‐bromo‐4‐chloro‐3‐indoxylpalmitate were used as substrates in an in vitro test with crude porcine pancreatic lipase. Bearberry (Arctostaphylos uva‐ursi), garden pea (Pisum sativum), Norway spruce (Picea abies) and large‐leaved lime (Tilia platyphyllos) extracts were the most active. Additionally, the activity of selected extracts with removed polyphenols was measured. Extracts of bearberry, garden pea and large‐leaved lime are a promising source for developing functional foods or isolating active compounds. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献