Convolutional neural networks predict the onset of paroxysmal atrial fibrillation: Theory and applications

In this study, we aimed to detect paroxysmal atrial fibrillation episodes before they occur so that patients can take precautions before putting their and others' lives in potentially life-threatening danger. We used the atrial fibrillation prediction database, open data from PhysioNet, and assembled our process based on convolutional neural networks. Conventional heart rate variability features are calculated from time-domain measures, frequency-domain measures using power spectral density estimations, time-frequency-domain measures using wavelet transform, and nonlinear Poincaré plot measures. In addition, we also applied an alternative heart rate normalization, which gave promising results only in a few studies, before calculating these heart rate variability features. We used these features directly and their normalized versions using min-max normalization and z-score normalization methods. Thus, heart rate variability features extracted from six different combinations of these normalizations, in addition to no normalization cases, were applied to the convolutional neural network classifier. We tuned the classifiers' hyperparameters using 90% of feature sets and tested the classifiers' performances using 10% of feature sets. The proposed approach resulted in 87.76% accuracy, 91.30% precision, 80.04% recall, and 87.50% f1-score in heart rate variability with z-score feature normalization. When the heart rate normalization was also utilized, the suggested method gave 100% accuracy, 100% precision, 100% recall, and 100% f1-score in heart rate variability with z-score feature normalization. The proposed method with heart rate normalization and z-score normalization methods resulted in better classification performance than similar studies in the literature. By comparing the existing studies, we conclude that our approach provides a much better tool to determine a near-future paroxysmal atrial fibrillation episode. However, although the achieved benchmarks are impressive, we note that the approach needs to be supported by other studies and on other datasets before clinical trials.

Lattice QCD Equation of State at Finite Chemical Potential from an Alternative Expansion Scheme

In this Letter, we introduce a novel scheme for extrapolating the equation of state of QCD to finite chemical potential that features considerably improved convergence properties and allows us to extend its reach to unprecedentedly high baryonic chemical potentials. We present continuum extrapolated lattice results for the new expansion coefficients and show the thermodynamic observables up to μ_{B}/T≤3.5. This novel expansion does not suffer from the shortcomings that characterize the traditional Taylor expansion method, such as difficulties inherent in performing such an expansion with a limited number of coefficients and the poor signal-to-noise ratio that affects Taylor coefficients determined from lattice calculations.

Synthesis and characterization of Mg-doped ZnO thin-films electrochemically grown on FTO substrates for optoelectronic applications

Mg-doped ZnO (MZO) thin films were successfully fabricated on fluorine-doped tin-oxide (FTO)-coated glass substrates by an electrochemical deposition method using aqueous electrolytes of 80 mM Zn(NO₃)₂ with different concentrations of Mg(NO₃)₂. The effects of Mg doping concentration on the electronic, microstructural, morphological, optical and electrical properties of the prepared films were investigated. The results of the Mott–Schottky (M–S) analysis revealed that the charge carrier density of n-type MZO films increases considerably when increasing the amount of Mg. As Mg concentration increased the Fermi level energy was also found to be increased by inclusion of Mg doping, which was confirmed by negative shifting of the flat band potential. XRD analysis showed that both undoped and Mg-doped ZnO thin films have a polycrystalline nature and hexagonal wurtzite structure with preferential orientation along the (002) axis. It is evident that the intensity of the (002) peak decreased with increasing Mg concentration. From scanning electron microscopy (SEM) analysis, it was found that when the amount of Mg concentration was increased in the solution, a decrease in the size of the grains was observed. The optical transmittance was found to be very high (∼85%) in the visible region of the solar spectrum. When the Mg content in the ZnO system was increased, a blue shifting of the absorption edge of the films was observed. The result of I–V measurements showed that the Mg doping was found to lead to an enhancement of the electrical properties of MZO thin films and the design of high-performance transparent conductive oxide (TCO) material.

Mg-doped ZnO (MZO) thin films were successfully fabricated on fluorine-doped tin-oxide (FTO)-coated glass substrates by an electrochemical deposition method using aqueous electrolytes of 80 mM Zn(NO₃)₂ with different concentrations of Mg(NO₃)₂.

A rare cause of intraabdominal hematoma: rupture of mesenteric artery branch aneurysm

Superior mesenteric artery (SMA) aneurysm is the third most common splanchnic artery aneurysm. Unlike other splanchnic artery aneurysm, isolated aneurysms of the SMA branches are rare. They are usually asymptomatic and difficult to detect until they rupture and cause abdominal pain and hypovolemic shock. Thus, most cases are diagnosed after the occurrence of complications. In this report, we described a 76-year-old woman who had two saccular aneurysms in the superior mesenteric arterial branch(es). One of them was ruptured and partly thrombosed. The patient had acute renal failure secondary to massive intraabdominal hemorrhage.

Can exposure to manganese and extremely low frequency magnetic fields affect some important elements in the rat teeth?

BACKGROUND

Length and level of exposure to electromagnetic fields (EMFs) is increasing in association with the widespread use of electrical and electronic devices and technological progress. The undesirable effects of extremely low frequency magnetic fields (ELF-MFs) on health have attracted considerable interest.

MATERIALS AND METHODS

Sixty-four four-month-old male Wistar rats divided into eight groups of eight rats each were used. Seven groups were exposed to varying dosages of manganese (Mn) and a 50 Hz magnetic field (MF) of approximately 1 mT, while the last group was set aside as the cage control group and not subjected to any procedure. This study was intended to investigate the interactions between the application of MF and Mn and the elements Ca, Zn, Mg, and P thought to be involved in caries, in rat teeth.

RESULTS

Levels of Ca, Mg, Zn, and P in the experimental group rats were different to those in the control group.

CONCLUSIONS

The results demonstrate that ELF-MF and Mn can have significant effects on levels of elements in rat teeth. Further experimental and epidemiological studies of ELF-MF and Mn are needed in order to evaluate their dental effects.

Fibroadenoma of the breast: diagnostic pitfalls of fine-needle aspiration

On fine-needle aspiration (FNA), fibroadenomas have a characteristic cytological appearance, although occasional cases are misinterpreted as carcinomas and vice versa. In a review of 521 breast aspirates correlated with the subsequent histology, six of 87 fibroadenomas (7%) were malignant or suspicious of malignancy on FNA (false positives). Following cytological review, four were still suspicious of malignancy because of cellular dyscohesion and prominent nucleoli, while two were fibroadenomas. On FNA, four of 145 carcinomas (3%) were diagnosed as fibroadenomas (false negatives). On review, three were malignant or suspicious of malignancy, while one was consistent with a fibroadenoma. Three false negative diagnoses were due to underappreciation of single malignant cells present between epithelial groupings typical of a fibroadenoma, while one was due to undersampling of the carcinoma. Cytologically, some fibroadenomas are sufficiently atypical that histological confirmation is necessary to exclude a malignancy. Misinterpreting carcinomas as fibroadenomas could be avoided by careful study of the morphology of isolated cells.

Atherosclerosis precursors in Finnish children and adolescents. VIII. Food consumption and nutrient intakes

A dietary survey was conducted in 1980 in connection with the Multicentre Study on Atherosclerosis Precursors in Finnish Children in five urban and 12 rural communes in various parts of Finland. 1,768 children aged 3, 6, 9, 12, 15 and 18 years were interviewed using the 48 hour recall method. Food consumption, and the intakes of energy and 49 nutrients were calculated. The intakes of energy and most nutrients increased in the successive age groups until the age of 15 years. There were only small differences in the diet of children belonging to different social classes. Protein accounted for 14% of total energy intake, fat for 38%, total carbohydrate for 48%, and sucrose for 10%. The ratio of polyunsaturated and saturated fatty acids in the diet (P/S) was 0.24 for the whole material, which is higher than found in previous studies in Finland. The P/S ratio was higher in urban areas and West Finland than in rural areas and in East Finland. The share of fat of energy intake exceeded the recommendation given by the Ministry of Health and the P/S ratio was lower than recommended. The mean daily intakes of energy and vitamins met the recommendations. Of the mineral elements, the intakes of calcium, phosphorus, potassium, magnesium and manganese were abundant. The intakes of iron, copper, zinc, molybdenum and chromium were lower than recommended in most age groups and the intakes of selenium and fluorine in all age groups. The large share of refined foods in the children's diet was the main reason for the low nutrient densities.

Maternal diet and fatty acid pattern of breast milk

The effect of habitual maternal diet on the fatty acid composition of breast milk was evaluated by conducting a dietary survey of lactating mothers and by analyzing their breast milk samples. The mean energy intake of the mothers was 9.8 MJ during the first survey week (20 mothers, 6-8 weeks post partum) and 8.6 MJ during the second survey week (13 mothers, 17-22 weeks post partum). Protein, fat and carbohydrate intake comprised 16%, 39% and 45% of the total energy intake, respectively. The breast milk samples contained 3.8% fat. Half of the fatty acids of the diets and breast milk were saturated (S), and one third were monoenoic. Polyunsaturated (P) fatty acids comprised 15% in the diets and 13% in the breast milk. The average P/S ratio was 0.3 both in the diets and breast milk samples. Carbohydrate intake correlated negatively (p less than 0.05) with arachidic acid of breast milk, and both protein and fat intakes correlated positively (p less than 0.05) with palmitic acid of breast milk. The maternal diet had no effect on the total fat content of breast milk. A positive correlation was found between the saturated (p less than 0.05) and polyunsaturated (p less than 0.01) fatty acids of maternal diet and breast milk. As to the single fatty acids, the only significant correlation was found with linoleic acid (p less than 0.01). However, the variation of linoleic acid intake explained only about 27% of the variation occurring in the breast milk.

Dietary chromium intake of lactating Finnish mothers: effect on the Cr content of their breast milk

1. The chromium in the diets of lactating Finnish mothers and of their breast milk was determined by graphite furnace atomic absorption. 2. The average maternal diet was estimated to provide approximately 30 micrograms Cr/d. Breast milk samples has a mean Cr content of 0.4 ng/ml, with a range of 0.19-0.69 ng/ml. 3. Cr intake of the lactating mothers did not correlate with the corresponding breast milk Cr concentration. 4. The diets and the breast milk of these Finnish mothers were lower in Cr than those of any other population studied in the world.

The effects of the dietary intakes of copper, iron, manganese, and zinc on the trace element content of human milk

Fifteeen breast-feeding mothers who volunteered for a study of trace elements in human milk, kept two 7-day food records during the course of lactation. The 1st survey week ranged from 6 to 8 weeks and the 2nd survey week from 17 to 22 weeks postpartum. The milk samples submitted for analysis represented a sample of every feed during a period of 24 hr and contained foremilk and hindmilk in equal proportions. The 7-day food records were handled by a computing system to give an average daily food consumption and nutrient intake, but iron was the only trace element given by the system. In order to estimate the trace element intakes of the mothers, mixtures were prepared to represent the average daily food consumption. The trace element concentrations of the mixtures and milk samples were analyzed using the atomic absorption spectrophotometric method. The estimated average daily copper intake was 1.8 mg, the iron intake 16 mg, the manganese intake 5 mg, and the zinc intake 13 mg. The mean copper, iron, manganese, and zinc concentrations of the milk samples were 0.36 +/- 0.07 mg/liter, 0.40 +/- 0.10 mg/liter, 4.5 +/- 1.8 microgram/liter, and 1.89 +/- 0.74 mg/liter for the 1st survey week and 0.21 +/- 0.07 mg/liter, 0.29 +/- 0.09 mg/liter, 4.0 +/- 1.5 microgram/liter, and 0.72 +/- 0.44 mg/liter for the 2nd survey week. A significant positive correlation (P less than 0.01) was observed in the 2nd survey week between maternal manganese intake and the manganese content of human milk. The intake of copper, iron, and zinc, at the present level of intake, did not seem to affect the corresponding trace element levels in human milk.