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Cold-chain environment could extend the survival duration of SARS-CoV-2 and increases the risk of transmission. However, the effect of clod-chain environmental factors and packaging materials on SARS-CoV-2 stability and the efficacy of intervention measures to inactivate SARS-CoV-2 under cold-chain environment remains uncertain. This study aimed to unravel cold-chain environmental factors that preserved the stability of SARS-CoV-2 and disinfection measures against SARS-CoV-2 under the cold-chain environment. The spike gene of SARS-CoV-2 isolated from Wuhan hu-1 was used to construct the SARS-CoV-2 pseudovirus and used as model of the SARS-CoV-2 virus. The decay rate of SARS-CoV-2 pseudovirus in the cold-chain environment, various types of packaging material surfaces i.e., PE plastic, stainless steel, Teflon and cardboard, and in frozen seawater was investigated. The influence of LED visible light(wavelength 450 nm-780 nm) and airflow movement on the stability of SARS-CoV-2 pseudovirus at -18{degrees} C were subsequently assessed. The results show that SARS-CoV-2 pseudovirus decayed more rapidly on porous cardboard surface compared with the non-porous surfaces including PE plastic, stainless steel and Teflon. Compared with 25{degrees} C, the decay rate of SARS-CoV-2 pseudovirus was significantly lower at low temperature. Seawater preserved viral stability both at -18{degrees} C and repeated freeze-thawing cycles compared with deionized water. LED visible light illumination and airflow movement environment at -18{degrees} C reduced the SARS-CoV-2 pseudovirus stability. In conclusion, our results indicate cold-chain temperature and seawater as risk factors for SARS-CoV-2 transmission and LED visible light illumination and airflow movement as possible disinfection measures of SARS-CoV-2 under the cold-chain environment. ImportanceIt is widely recognized that low temperature is a condition for maintaining virus vitality, and cold-chain transportation spreads the events of the SARS-CoV-2 were reported. This study provides that the decay rate of the SARS-CoV-2 pseudovirus at low temperatures varies on different packaging materials, and salt ions present in frozen foods such as seafood may protect virus survival. These results provide evidence for the possibility of SARS-CoV-2 transmission through cold-chain transport and also suggest the importance for disinfection of items. However, the commonly used disinfection methods of ultraviolet radiation and chemical reagents are generally not suitable for the disinfection of frozen food. Our study shows LED visible light illumination and airflow movement as possible disinfection measures of SARS-CoV-2 under the cold-chain environment. This has implications for reducing the long-distance transmission of the virus through cold-chain transportation.
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Objective To research and develop the mobile platform-oriented echocardiogram data visualization technology for the evaluation of left ventricular diastolic function,and investigate its application value.Methods First,diagnostic algorithms for the evaluation of left ventricular diastolic function (based on recommendations from ASE & EAE guidelines) were programmed into a mobile application software package,using Adobe Flex builder 4.0 as a basic tool for data visualization.Second,the program was installed in the Apple iPad4 tablet computer,then debugged and improved according to feedback information from practical applications.Results The echocardiogram data visualization for the estimation of left ventricular filling pressures in patients with depressed ejection fraction(EF) or normal EF and grading diastolic function can be implemented in mobile platform device,and simultaneously with emergency bedside echocardiography.The evaluation process can be visually presented by using the graphics to show the algorithm framework,the animation to express the analysis step,the axis to indicate the direction of information,and the color to differentiate the degree of the diastolic dysfunction.Conclusions The mobile platform-oriented echocardiogram data visualization technology makes the evaluation of left ventricular diastolic function more convenient,efficient and fast,and shows its potential to become an important adjunct to evaluation of cardiac function in the context of mobile health.
ABSTRACT
<p><b>OBJECTIVE</b>To quantitatively assess the left ventricular systolic dyssynchrony in patients with chronic heart failure based on the regional systolic dyssynchrony index (R-SDI) derived from real-time three-dimensional echocardiography (RT-3DE), and investigate the relation between R-SDI and the left ventricular systolic function.</p><p><b>METHODS</b>Forty-two patients with chronic heart failure (LVEF<50%) were classified into severe dysfunction group (group A, LVEF<40%) and mild dysfunction group (group B, LVEF≥40%), with 33 healthy subjects as the control group (LVEF>50%). RT-3DE was performed for each subject to obtain the left volume-time curves and the 16, 12, and 6 segment R-SDI. The value of R-SDI in assessing left ventricular systolic dyssynchrony and its correlation with LVEF were analyzed.</p><p><b>RESULTS</b>The 16, 12, and 6R-SDI were significantly higher in the chronic heart failure group than in the control group (P<0.01). The R-SDI of group A was significantly greater than those of group B in the chronic heart failure patients (P<0.01), and 16R-SDI, 12R-SDI, and 6R-SDI were inversely correlated with LVEF of the patients (r=-0.843, -0.840, and -0.841, respectively, P<0.01).</p><p><b>CONCLUSIONS</b>R-SDI can be used to assess the left ventricular mechanic systolic dyssynchrony, and the degree of the dyssynchrony is inversely correlated with LVEF. RT-3DE can serve as a valuable modality for quantitative evaluation of left ventricular dyssynchrony in chronic heart failure patients.</p>
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Case-Control Studies , Chronic Disease , Echocardiography, Three-Dimensional , Methods , Heart Failure , Diagnostic Imaging , Heart Ventricles , Diagnostic Imaging , Systole , Ventricular Dysfunction, Left , Diagnostic Imaging , Ventricular Function, LeftABSTRACT
ObjectiveTo build the computer-aided diagnosis system of left ventricular diastolic function for echocardiography,to make the evaluation process of left ventricular diastolic function for echocardiography more convenient,efficient,standardized and to obtain more accurate,practical,objective and reliable diagnostic results.MethodsFirst,the system was developed by the Macromedia Flash Professional referred to the newest guidelines and suggestions published by the American Society of Echocardiography(ASE) in 2009.Second,the program of left ventricular diastolic function in the computer- aided diagnosis system was designed,debugged and improved according to feedback information frompractical applications.ResultsThe diagnostic system can work simultaneously with echocardiography.If assessment parameters of the newest guidelines and suggestions,published by the American Society of Echocardiography in 2009,are imported to the system,then it can give the diagnosis of the change about the left ventricle filling pressures and score the left ventricular diastolic function quickly and automatically.The system will export standard report with both pictures and text.ConclusionsAccording to our experiment,the computer-aided diagnosis system is able to make the evaluation process of left ventricular diastolic function much more standardized and simplified,which guarantee the objectivity and reliability of the evaluation results.Consequently,it will be able to apply to clinical practice in the future.
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This paper presents a text-independent speaker verification system based on an online Radial Basis Function (RBF) network referred to as Minimal Resource Allocation Network (MRAN). MRAN is a sequential learning RBF, in which hidden neurons are added or removed as training progresses. LP-derived cepstral coefficients are used as feature vectors during training and verification phases. The performance of MRAN is compared with other well-known RBF and Elliptical Basis Function (EBF) based speaker verification methods in terms of error rates and computational complexity on a series of speaker verification experiments. The experiments use data from 258 speakers from the phonetically balancedcontinuous speech corpus TIMIT. The results show that MRAN produces comparable error rates to other methods with much less computational complexity.
Subject(s)
Models, Neurological , Neural Networks, Computer , Neurons/physiology , Speech Recognition Software , Algorithms , Artificial Intelligence , Humans , Sensitivity and SpecificityABSTRACT
Fourteen cases of pheochromocytoma diagnosed by B-tnode ultrasound were reported. All of them the diagnoses were confirmed by operation and pathology. Three tumors crose in right and 5 in left and 4 in bilateral adrenal glands; two were extraadrenal. The ultrasonographic features of pheochromocytoma and its differential diagnosis were discussed. The ultrasonic diagnosis of extra-adrenal pheochromocytoma is objectively assessed; it has significant importance especially in the surgical resection of the tumor.
