528 research outputs found
Ключевые принципы менеджмента качества в зерновом производстве
Целью исследования является построение усовершенствованной системы ключевых принципов менеджмента качества зерна, как базиса управления конкурентоспособностью продукции национальных производителей. Достижению указанной цели способствует решение следующих задач: систематизировать принципы, используемые для приведения качества продукции в соответствие динамично изменяющимся требованиям заинтересованных сторон; исследовать современные требования к менеджменту качества пищевых продуктов и тенденции их изменения
Current and future role of echocardiography in arrhythmogenic right ventricular dysplasia/cardiomyopathy
Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is an inherited progressive cardiomyopathy, clinically characterized by ventricular arrhythmias and increased risk of sudden cardiac death. Echocardiography has a role in the diagnosis and prognosis of ARVD/C. However, in the current era of magnetic resonance imaging (MRI), the role of echocardiography in ARVD/C patients and family member screening is subject to debate. Relatively novel echocardiographic techniques, such as three-dimensional right ventricular (3D-RV) imaging and tissue deformation imaging, may improve the diagnostic and prognostic performance of echocardiography in these patients. 3D-RV imaging provides more insights on RV anatomy and global function compared to conventional echocardiography. Subtle RV regional wall motion abnormalities, and mechanical dyssynchrony, are accurately measured by tissue deformation imaging. Several studies suggest an incremental value of novel echocardiographic parameters in addition to conventional measurements. Moreover, new parameters indicating subtle RV dysfunction, and mechanical dyssynchrony, are of predictive value and could help in risk stratification of ARVD/C patients. New robust parameters, derived from 3D-RV echocardiography and RV tissue deformation imaging, in combination with established conventional parameters, suggest that there is a current and future role for echocardiography in ARVD/C supplementing MRI
Расчет электромагнитного поля в электронных модулях с использованием интеграла Зоммерфельда
Излагается подход с использованием интеграла Зоммерфельда. Метод позволяет избежать интегрирования в комплексной области и снизить объем вычислений по сравнению с известными методами
Higher functionality of extracellular vesicles isolated using size-exclusion chromatography compared to ultracentrifugation
Extracellular vesicles (EVs) are nano-sized, lipid bilayer-enclosed particles involved in intercellular communication. EVs are increasingly being considered as drug delivery vehicles or as cell-free approach to regenerative medicine. However, one of the major challenges for their clinical application is finding a scalable EV isolation method that yields functional EVs. Although the golden standard for EV isolation is ultracentrifugation (UC), a recent study suggested that isolation using size-exclusion chromatography (SEC) yielded EVs with more intact biophysical properties. Whether this also leads to differences in functionality remained to be investigated. Therefore, we investigated possible differences in functionality of cardiomyocyte progenitor cell-derived EVs isolated using UC and SEC. Western blot analysis showed higher pERK/ERK ratios in endothelial cells after stimulation with SEC-EVs compared to UC-EVs, indicating that SEC-EVs bear higher functionality. Therefore, we propose to use SEC-EVs for further investigation of EVs' therapeutic potential. Further optimization of isolation protocols may accelerate clinical adoption of therapeutic EVs.Therapeutic cell differentiatio
Некоторые проблемы добычи полезных ископаемых на глубоких горизонтах недр
Cardiovascular screening may benefit middle-aged sportsmen, as coronary artery disease (CAD) is the main cause of exercise-related sudden cardiac death. Arterial stiffness, as measured by pulse wave velocity (PWV), may help identify sportsmen with subclinical CAD. We examined the additional value of PWV measurements to traditional CAD risk factors for identifying CAD.From the Measuring Athlete's Risk of Cardiovascular events (MARC) cohort of asymptomatic, middle-aged sportsmen who underwent low-dose Cardiac CT (CCT) after routine sports medical examination (SME), 193 consecutive sportsmen (aged 55 ± 6.6 years) were included with additional PWV measurements before CCT. Sensitivity, specificity and predictive values of PWV values (>8.3 and >7.5 m/s) assessed by Arteriograph were used to identify CAD (coronary artery calcium scoring ≥ 100 Agatston Units or coronary CT angiography luminal stenosis ≥ 50%) and to assess the additional diagnostic value of PWV to established cardiovascular risk factors.Forty-seven sportsmen (24%) had CAD on CCT. They were older (58.9 vs. 53.8 years, p<0.001), had more hypertension (17 vs. 4%, p=0.003), higher cholesterol levels (5.7 vs. 5.4 mmol/l) p=0.048), and more often were (ever) smokers (55 vs. 34%, p=0.008). Mean PWV was higher in those with CAD (8.9 vs. 8.0 m/s, p=0.017). For PWV >8.3m/s respectively >7.5 m/s sensitivity to detect CAD on CT was 43% and 74%, specificity 69% and 45%, positive predictive value 31% and 30%, and negative predictive value 79% and 84%. Adding PWV to traditional risk factor models did not change the area under the curve (from 0.78 (95% CI = 0.709-0.848)) to AUC 0.78 (95% CI 0.710-0.848, p = 0.99)) for prediction of CAD on CCT.Limited additional value was found for PWV on top of established risk factors to identify CAD. PWV might still have a role to identify CAD in middle-aged sportsmen if risk factors such as cholesterol are unknown
Controlled delivery of gold nanoparticle-coupled miRNA therapeutics via an injectable self-healing hydrogel
Differential expression of microRNAs (miRNAs) plays a role in many diseases, including cancer and cardiovascular diseases. Potentially, miRNAs could be targeted with miRNA-therapeutics. Sustained delivery of these therapeutics remains challenging. This study couples miR-mimics to PEG-peptide gold nanoparticles (AuNP) and loads these AuNP-miRNAs in an injectable, shear thinning, self-assembling polymer nanoparticle (PNP) hydrogel drug delivery platform to improve delivery. Spherical AuNPs coated with fluorescently labelled miR-214 are loaded into an HPMC-PEG-b-PLA PNP hydrogel. Release of AuNP/miRNAs is quantified, AuNP-miR-214 functionality is shown in vitro in HEK293 cells, and AuNP-miRNAs are tracked in a 3D bioprinted human model of calcific aortic valve disease (CAVD). Lastly, biodistribution of PNP-AuNP-miR-67 is assessed after subcutaneous injection in C57BL/6 mice. AuNP-miRNA release from the PNP hydrogel in vitro demonstrates a linear pattern over 5 days up to 20%. AuNP-miR-214 transfection in HEK293 results in 33% decrease of Luciferase reporter activity. In the CAVD model, AuNP-miR-214 are tracked into the cytoplasm of human aortic valve interstitial cells. Lastly, 11 days after subcutaneous injection, AuNP-miR-67 predominantly clears via the liver and kidneys, and fluorescence levels are again comparable to control animals. Thus, the PNP-AuNP-miRNA drug delivery platform provides linear release of functional miRNAs in vitro and has potential for in vivo applications.publishersversionpublishe
Nasopharyngeal Myoepithelial Carcinoma Mimicking Nasopharyngeal Carcinoma
AbstractMyoepithelial carcinoma (malignant myoepithelioma) (MC) is a rare tumor, defined as a malignant salivary neoplasm composed almost exclusively of tumor cells with myoepithelial differentiation. It can arise in unusual location sites, such as the nasopharynx, and may be difficult to approach. Nasopharyngeal MC can sometimes present as a nasopharyngeal mass which may be mistaken for primary nasopharyngeal carcinoma (NPC). The treatment strategy for nasopharyngeal MC is different from NPC, and maximal surgical resection of the main lesion is still considered as the mainstay of therapy. Herein we present a 32-year-old man with a nasopharyngeal mass which was initially mistaken as NPC, and which was later confirmed as MC after a comprehensive review of the pathology
Discovering and Visualizing Disease-Specific Electrocardiogram Features Using Deep Learning: Proof-of-Concept in Phospholamban Gene Mutation Carriers
BACKGROUND: ECG interpretation requires expertise and is mostly based on physician recognition of specific patterns, which may be challenging in rare cardiac diseases. Deep neural networks (DNNs) can discover complex features in ECGs and may facilitate the detection of novel features which possibly play a pathophysiological role in relatively unknown diseases. Using a cohort of PLN (phospholamban) p.Arg14del mutation carriers, we aimed to investigate whether a novel DNN-based approach can identify established ECG features, but moreover, we aimed to expand our knowledge on novel ECG features in these patients. METHODS: A DNN was developed on 12-lead median beat ECGs of 69 patients and 1380 matched controls and independently evaluated on 17 patients and 340 controls. Differentiating features were visualized using Guided Gradient Class Activation Mapping++. Novel ECG features were tested for their diagnostic value by adding them to a logistic regression model including established ECG features. RESULTS: The DNN showed excellent discriminatory performance with a c-statistic of 0.95 (95% CI, 0.91-0.99) and sensitivity and specificity of 0.82 and 0.93, respectively. Visualizations revealed established ECG features (low QRS voltages and T-wave inversions), specified these features (eg, R- and T-wave attenuation in V2/V3) and identified novel PLN-specific ECG features (eg, increased PR-duration). The logistic regression baseline model improved significantly when augmented with the identified features (P<0.001). CONCLUSIONS: A DNN-based feature detection approach was able to discover and visualize disease-specific ECG features in PLN mutation carriers and revealed yet unidentified features. This novel approach may help advance diagnostic capabilities in daily practice
Anti-fibrotic Effects of Cardiac Progenitor Cells in a 3D-Model of Human Cardiac Fibrosis
Cardiac fibroblasts play a key role in chronic heart failure. The conversion from cardiac fibroblast to myofibroblast as a result of cardiac injury, will lead to excessive matrix deposition and a perpetuation of pro-fibrotic signaling. Cardiac cell therapy for chronic heart failure may be able to target fibroblast behavior in a paracrine fashion. However, no reliable human fibrotic tissue model exists to evaluate this potential effect of cardiac cell therapy. Using a gelatin methacryloyl hydrogel and human fetal cardiac fibroblasts (hfCF), we created a 3D in vitro model of human cardiac fibrosis. This model was used to study the possibility to modulate cellular fibrotic responses. Our approach demonstrated paracrine inhibitory effects of cardiac progenitor cells (CPC) on both cardiac fibroblast activation and collagen synthesis in vitro and revealed that continuous cross-talk between hfCF and CPC seems to be indispensable for the observed anti-fibrotic effect
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