An Automatic Approach for Individual HU-Based Characterization of Lungs in COVID-19 Patients

The ongoing COVID-19 pandemic currently involves millions of people worldwide. Radiology plays an important role in the diagnosis and management of patients, and chest computed tomography (CT) is the most widely used imaging modality. An automatic method to characterize the lungs of COVID-19 patients based on individually optimized Hounsfield unit (HU) thresholds was developed and implemented. Lungs were considered as composed of three components—aerated, intermediate, and consolidated. Three methods based on analytic fit (Gaussian) and maximum gradient search (using polynomial and original data fits) were implemented. The methods were applied to a population of 166 patients scanned during the first wave of the pandemic. Preliminarily, the impact of the inter-scanner variability of the HU-density calibration curve was investigated. Results showed that inter-scanner variability was negligible. The median values of individual thresholds th1 (between aerated and intermediate components) were −768, −780, and −798 HU for the three methods, respectively. A significantly lower median value for th2 (between intermediate and consolidated components) was found for the maximum gradient on the data (−34 HU) compared to the other two methods (−114 and −87 HU). The maximum gradient on the data method was applied to quantify the three components in our population—the aerated, intermediate, and consolidation components showed median values of 793 ± 499 cc, 914 ± 291 cc, and 126 ± 111 cc, respectively, while the median value of the first peak was −853 ± 56 HU.

Climatology and annual displacement of the upper-level frontal zones in the middle troposphere of the Northern Hemisphere

An updated climatology of upper level frontal zones (UFZ) of the Northern Hemisphere is presented, based on a numerical analysis of geopotential gradients and the allocation of maximum gradient zones. Differences in the position of the UFZ during the development of meridional and zonal processes are revealed. Based on the analysis of years with the predominance of various forms of circulation, it is shown that the position of high-altitude frontal zones is an objective diagnostic tool for studying modern climate variability.

Anesthetic management during endocardial radiofrequency ablation of septal hypertrophy – a case report

Background: Hypertrophic cardiomyopathy (HCM) is a genetic disorder present in up to 1/500 individuals, about 20–30% of them presenting with hypertrophic obstructive cardiomyopathy (HOCM) due to left ventricle outflow tract obstruction. This is an important cause of sudden cardiac death. Endocardial radiofrequency ablation of septal hypertrophy (ERASH) might be an attractive treatment for HOCM, particularly in patients who do not respond to transcoronary alcohol septal ablation (TASA).Aim: To describe technical aspects related to the procedure and anesthetic management of an ERASH case.Case report: A 64-year-old woman with HOCM was scheduled for ERASH. She had worsening of dyspnea on exertion and generalized fatigue for the previous weeks after previous surgical myomectomy about 6 months ago. The anatomy was unfavorable for TASA and the patient was not willing to undergo another surgery. Preoperative transthoracic echocardiography (TTE) showed asymmetric mid-septal hypertrophy, systolic anterior motion with septal contact and left ventricular outflow tract maximum gradient of 68 mmHg at rest and 105 mmHg after the Valsalva maneuver. General anesthesia was performed. Pulse pressure variation, echocardiography parameters and passive leg raising test where used to guide fluid therapy. At the end of the procedure, analgesia was provided together with prophylaxis of nausea and vomiting. Extubation was uneventful and the patient was transported to the intensive care unit eupneic and hemodynamically stable. On the fourth postoperative day, TTE showed septal hypocontractility and maximum gradient reduction of 33% at rest (68 mmHg to 45 mmHg) and 31% after the Valsalva maneuver (105 mmHg to 73 mmHg). The patient was discharged from hospital at the sixth postoperative day. One month later, she reported progressive improvement of symptoms and expressed satisfaction with the results.Conclusion: Better understanding of the pathophysiology and natural history of HCM has enabled earlier diagnosis, as well as a more adequate therapeutic approach. Anesthesiologists should be aware of the pathophysiology of HOCM and must be prepared to anticipate the hemodynamic changes and cardiovascular instability that such patients may show perioperatively. ERASH is a promising therapeutic modality increasingly used for HOCM and anesthesiologists should become more familiar with it.

Research on Distinguishing Fish Meal Quality Using Different Characteristic Parameters Based on Electronic Nose Technology

In this paper, a portable electronic nose, that was independently developed, was employed to detect and classify a fish meal of different qualities. SPME-GC-MS (solid phase microextraction gas chromatography mass spectrometry) analysis of fish meal was presented. Due to the large amount of data of the original features detected by the electronic nose, a reasonable selection of the original features was necessary before processing, so as to reduce the dimension. The integral value, wavelet energy value, maximum gradient value, average differential value, relation steady-state response average value and variance value were selected as six different characteristic parameters, to study fish meal samples with different storage time grades. Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA), and five recognition modes, which included the multilayer perceptron neural network classification method, random forest classification method, k nearest neighbor algorithm, support vector machine algorithm, and Bayesian classification method, were employed for the classification. The result showed that the RF classification method had the highest accuracy rate for the classification algorithm. The highest accuracy rate for distinguishing fish meal samples with different qualities was achieved using the integral value, stable value, and average differential value. The lowest accuracy rate for distinguishing fish meal samples with different qualities was achieved using the maximum gradient value. This finding shows that the electronic nose can identify fish meal samples with different storage times.