44 research outputs found
Использование растровых графических редакторов для обработки археологических материалов
В данной работе предлагается к рассмотрению компьютерная графика в качестве инструмента для создания стратиграфических чертежей и приводится краткое описание технологии, которая сегодня широко используется при составлении отчетов многих археологических экспедиций в Крыму
В портфеле редакции
OBJECTIVE Our aim is to compare the effect of type 2 diabetes on recurrent major cardiovascular events (MCVE) for patients with symptomatic vascular disease at different locations. RESEARCH DESIGN AND METHODS A total of 6,841 patients from the single-center, prospective Second Manifestations of ARTerial disease (SMART) cohort study from Utrecht, the Netherlands, with clinically manifest vascular disease with (n = 1,155) and without (n = 5,686) type 2 diabetes were monitored between 1996 and 2013. The effect of type 2 diabetes on recurrent MCVE was analyzed with Cox proportional hazards models, stratified for disease location (cerebrovascular disease, peripheral artery disease, abdominal aortic aneurysm, coronary artery disease, or polyvascular disease, defined as >= 2 vascular locations). RESULTS Five-year risks for recurrent MCVE were 9% in cerebrovascular disease, 9% in peripheral artery disease, 20% in those with an abdominal aortic aneurysm, 7% in coronary artery disease, and 21% in polyvascular disease. Type 2 diabetes increased the risk of recurrent MCVE in coronary artery disease (hazard ratio [HR] 1.67; 95% CI 1.25-2.21) and seemed to increase the risk in cerebrovascular disease (HR 1.36; 95% CI 0.90-2.07), while being no risk factor in polyvascular disease (HR 1.12; 95% CI 0.83-1.50). Results for patients with peripheral artery disease (HR 1.42; 95% CI 0.79-2.56) or an abdominal aortic aneurysm (HR 0.93; 95% CI 0.23-3.68) were inconclusive. CONCLUSIONS Type 2 diabetes increased the risk of recurrent MCVE in patients with coronary artery disease, but there is no convincing evidence that it is a major risk factor for subsequent MCVE in all patients with symptomatic vascular disease
Достаточные условия стойкости рандомизированных блочных cистем шифрования относительно метода криптоанализа на основе коммутативных диаграмм
Получены достаточные условия отсутствия определенных нетривиальных конгруэнций многоосновных алгебр, описывающих рандомизированные блочные системы шифрования, соответствующие SPN-подобным шифрам или шифрам Фейстеля. Указанные условия исключают возможность применения к таким системам шифрования метода криптоанализа на основе коммутативных диаграмм.Отримано достатні умови відсутності певних нетривіальних конгруенцій багатоосновних універсальних алгебр, що описують рандомізовані блокові системи шифрування, які відповідають SPN-подібним шифрам або шифрам Фейстеля. Зазначені умови виключають можливість застосування до таких систем шифрування методу криптоаналізу на основі комутативних діаграм.Sufficient conditions for the non-existence of certain nontrivial congruences of many-sorted universal algebras, that describe randomized block cipher systems based on the SPN-like ciphers or on Feistel ciphers, are obtained. These conditions guarantee that such cipher systems are secure against commutative diagram attacks
Factors Associated with D-Dimer Levels in HIV-Infected Individuals
Matti A Ristola on työryhmän jäsen.Peer reviewe
Association of white matter hyperintensity markers on MRI and long-term risk of mortality and ischemic stroke the SMART-MR study
ObjectiveTo determine whether white matter hyperintensity (WMH) markers on MRI are associated with long-term risk of mortality and ischemic stroke.MethodsWe included consecutive patients with manifest arterial disease enrolled in the Second Manifestations of Arterial Disease-Magnetic Resonance (SMART-MR) study. We obtained WMH markers (volume, type, and shape) from brain MRI scans performed at baseline using an automated algorithm. During follow-up, occurrence of death and ischemic stroke was recorded. Using Cox regression, we investigated associations of WMH markers with risk of mortality and ischemic stroke, adjusting for demographics, cardiovascular risk factors, and cerebrovascular disease.ResultsWe included 999 patients (59 +/- 10 years; 79% male) with a median follow-up of 12.5 years (range 0.2-16.0 years). A greater periventricular or confluent WMH volume was independently associated with a greater risk of vascular death (hazard ratio [HR] 1.29, 95% confidence interval [CI] 1.13-1.47) for a 1-unit increase in natural log-transformed WMH volume and ischemic stroke (HR 1.53, 95% CI 1.26-1.86). A confluent WMH type was independently associated with a greater risk of vascular (HR 1.89, 95% CI 1.15-3.11) and nonvascular death (HR 1.65, 95% CI 1.01-2.73) and ischemic stroke (HR 2.83, 95% CI 1.36-5.87). A more irregular shape of periventricular or confluent WMH, as expressed by an increase in concavity index, was independently associated with a greater risk of vascular (HR 1.20, 95% CI 1.05-1.38 per SD increase) and nonvascular death (HR 1.21, 95% CI 1.03-1.42) and ischemic stroke (HR 1.28, 95% CI 1.05-1.55).ConclusionsWMH volume, type, and shape are associated with long-term risk of mortality and ischemic stroke in patients with manifest arterial disease.Neuro Imaging Researc
Reduced parenchymal cerebral blood flow is associated with greater progression of brain atrophy: the SMART-MR study
Global cerebral hypoperfusion may be involved in the aetiology of brain atrophy; however, long-term longitudinal studies on this relationship are lacking. We examined whether reduced cerebral blood flow was associated with greater progression of brain atrophy. Data of 1165 patients (61 +/- 10 years) from the SMART-MR study, a prospective cohort study of patients with arterial disease, were used of whom 689 participated after 4 years and 297 again after 12 years. Attrition was substantial. Total brain volume and total cerebral blood flow were obtained from magnetic resonance imaging scans and expressed as brain parenchymal fraction (BPF) and parenchymal cerebral blood flow (pCBF). Mean decrease in BPF per year was 0.22% total intracranial volume (95% CI: -0.23 to -0.21). Mean decrease in pCBF per year was 0.24 ml/min per 100 ml brain volume (95% CI: -0.29 to -0.20). Using linear mixed models, lower pCBF at baseline was associated with a greater decrease in BPF over time (p = 0.01). Lower baseline BPF, however, was not associated with a greater decrease in pCBF (p = 0.43). These findings indicate that reduced cerebral blood flow is associated with greater progression of brain atrophy and provide further support for a role of cerebral blood flow in the process of neurodegeneration.Neuro Imaging Researc
Detection and characterization of small infarcts in the caudate nucleus on 7 Tesla MRI: the SMART-MR study
Small infarcts are among the key imaging features of cerebral small vessel disease (CSVD), but remain largely undetected on conventional MRI. We aimed to evaluate (1) imaging criteria for the detection of small infarcts in the caudate nucleus on 7T MRI, (2) intra- and inter-rater agreement, (3) frequency and (4) detection rate on 7T versus 1.5T MRI. In 90 patients (68 ± 8 years) with a history of vascular disease from the SMART-MR study, we defined 7T imaging criteria for cavitated and non-cavitated small infarcts in the caudate nucleus. In a separate set of 23 patients from the SMART study, intra-rater and inter-rater agreement was excellent for presence, number, and individual locations (Kappa’s, ICCs, and Dice similarity coefficients ranged from 0.85 to 1.00). In the 90 patients, 21 infarcts (20 cavitated) in 12 patients were detected on 7T (13%) compared to 7 infarcts in 6 patients on 1.5T (7%). In conclusion, we established reproducible imaging criteria for the detection of small infarcts in the caudate nucleus on 7T MRI and showed that 7T MRI allows for a higher detection rate than conventional 1.5T MRI. These imaging criteria can be used in future studies to provide new insights into the pathophysiology of CSVD.</p
Performing a knee arthroscopy among patients with degenerative knee disease: one-third is potentially low value care
Purpose The purpose of this study was to assess in which proportion of patients with degenerative knee disease aged 50+ in whom a knee arthroscopy is performed, no valid surgical indication is reported in medical records, and to explore possible explanatory factors.Methods A retrospective study was conducted using administrative data from January to December 2016 in 13 orthopedic centers in the Netherlands. Medical records were selected from a random sample of 538 patients aged 50+ with degenerative knee disease in whom arthroscopy was performed, and reviewed on reported indications for the performed knee arthroscopy. Valid surgical indications were predefined based on clinical national guidelines and expert opinion (e.g., truly locked knee). A knee arthroscopy without a reported valid indication was considered potentially low value care. Multivariate logistic regression analysis was performed to assess whether age, diagnosis ("Arthrosis" versus "Meniscal lesion"), and type of care trajectory (initial or follow-up) were associated with performing a potentially low value knee arthroscopy.Results Of 26,991 patients with degenerative knee disease, 2556 (9.5%) underwent an arthroscopy in one of the participating orthopedic centers. Of 538 patients in whom an arthroscopy was performed, 65.1% had a valid indication reported in the medical record and 34.9% without a reported valid indication. From the patients without a valid indication, a joint patient-provider decision or patient request was reported as the main reason. Neither age [OR 1.013 (95% CI 0.984-1.043)], diagnosis [OR 0.998 (95% CI 0.886-1.124)] or type of care trajectory [OR 0.989 (95% CI 0.948-1.032)] were significantly associated with performing a potentially low value knee arthroscopy.Conclusions In a random sample of knee arthroscopies performed in 13 orthopedic centers in 2016, 65% had valid indications reported in the medical records but 35% were performed without a reported valid indication and, therefore, potentially low value care. Patient and/or surgeons preference may play a large role in the decision to perform an arthroscopy without a valid indication. Therefore, interventions should be developed to increase adherence to clinical guidelines by surgeons that target invalid indications for a knee arthroscopy to improve care.Orthopaedics, Trauma Surgery and Rehabilitatio
Prothrombotic Gene Variants and Mortality after Cerebral Ischemia of Arterial Origin
Thrombosis and Hemostasi
