Arrhythmia Classification Algorithm Based on Multi-Feature and Multi-type Optimized SVM

The electrocardiogram (ECG) signal feature extraction and classification diagnosis algorithm is proposed to address the high incidence of heart disease and difficulty in self-detection. First, the collected ECG signals are preprocessed to remove the noise of the ECG signals. Next, wavelet packet decomposition is used to perform a four-layer transformation on the denoised ECG signal and the 16 obtained wavelet packet coefficients analyzed statistically. Next, the slope threshold method is used to extract the R-peak of the denoised ECG signal. The RR interval can be calculated according to the extracted R peak. The extracted statistical features and time domain RR interval features are combined into a multi-domain feature space. Finally, the particle swarm optimization algorithm (PSO), genetic algorithm (GA), and grid search (GS) algorithms are applied to optimize the support vector machine (SVM). The optimized SVM is utilized to classify the extracted multi-domain features. Classification results show the proposed algorithm can classify six types of ECG beats accurately. The classification efficiency achieved by PSO, GA, and GS are 97.78%, 98.33%, and 98.89%, respectively

Artificial Intelligence-Enabled ECG Algorithm Based on Improved Residual Network for Wearable ECG

Heart disease is the leading cause of death for men and women globally. The residual network (ResNet) evolution of electrocardiogram (ECG) technology has contributed to our understanding of cardiac physiology. We propose an artificial intelligence-enabled ECG algorithm based on an improved ResNet for a wearable ECG. The system hardware consists of a wearable ECG with conductive fabric electrodes, a wireless ECG acquisition module, a mobile terminal App, and a cloud diagnostic platform. The algorithm adopted in this study is based on an improved ResNet for the rapid classification of different types of arrhythmia. First, we visualize ECG data and convert one-dimensional ECG signals into two-dimensional images using Gramian angular fields. Then, we improve the ResNet-50 network model, add multistage shortcut branches to the network, and optimize the residual block. The ReLu activation function is replaced by a scaled exponential linear units (SELUs) activation function to improve the expression ability of the model. Finally, the images are input into the improved ResNet network for classification. The average recognition rate of this classification algorithm against seven types of arrhythmia signals (atrial fibrillation, atrial premature beat, ventricular premature beat, normal beat, ventricular tachycardia, atrial tachycardia, and sinus bradycardia) is 98.3%

Fully Photonic Integrated Wearable Optical Interrogator

Wearable technology constitutes a pioneering and leading innovation and a market development platform worldwide for technologies worn close to the body. Wearable optical fiber sensors have the most value for advanced multiparameter sensing in digital health monitoring systems. We demonstrated the first example of a fully integrated optical interrogator. By integrating all the optical components on a silicon photonic chip, we realized a stable, miniaturized and low-cost optical interrogator for the continuous, dynamic, and long-term acquisition of human physiological signals. The interrogator was integrated in a wristband, enabling the detection of body temperature and heart sounds. Our study paves the way for the development of watch-sized integrated wearable optical interrogators with potential applications in health monitoring and can be directly exploited for the customized design of ultraminiaturized optical interrogator systems.H.L. acknowledges the support from the Tianjin Talent Special Support Program. J.D.P.G. acknowledges the support from the Serra Hunter Program, the ICREA Academia Program, and the Tianjin Distinguished University Professor Program. This work was supported by the National Natural Science Foundation of China (no. 61675154), the Tianjin Key Research and Development Program (no. 19YFZCSY00180), the Tianjin Major Project for Civil-Military Integration of Science and Technology (no. 18ZXJMTG00260), the Tianjin Science and Technology Program (no. 20YDTPJC01380), and the Tianjin Municipal Special Foundation for Key Cultivation of China (no. XB202007)

Development of a growth-coupled selection platform for directed evolution of heme biosynthetic enzymes in Corynebacterium glutamicum

Heme is an important tetrapyrrole compound, and has been widely applied in food and medicine industries. Although microbial production of heme has been developed with metabolic engineering strategies during the past 20 years, the production levels are relatively low due to the multistep enzymatic processes and complicated regulatory mechanisms of microbes. Previous studies mainly adopted the strategies of strengthening precursor supply and product transportation to engineer microbes for improving heme biosynthesis. Few studies focused on the engineering and screening of efficient enzymes involved in heme biosynthesis. Herein, a growth-coupled, high-throughput selection platform based on the detoxification of Zinc-protoporphyrin IX (an analogue of heme) was developed and applied to directed evolution of coproporphyrin ferrochelatase, catalyzing the insertion of metal ions into porphyrin ring to generate heme or other tetrapyrrole compounds. A mutant with 3.03-fold increase in kcat/KM was selected. Finally, growth-coupled directed evolution of another three key enzymes involved in heme biosynthesis was tested by using this selection platform. The growth-coupled selection platform developed here can be a simple and effective strategy for directed evolution of the enzymes involved in the biosynthesis of heme or other tetrapyrrole compounds

Common Molecular Etiologies Are Rare in Nonsyndromic Tibetan Chinese Patients with Hearing Impairment

Background: Thirty thousand infants are born every year with congenital hearing impairment in mainland China. Racial and regional factors are important in clinical diagnosis of genetic deafness. However, molecular etiology of hearing impairment in the Tibetan Chinese population living in the Tibetan Plateau has not been investigated. To provide appropriate genetic testing and counseling to Tibetan families, we investigated molecular etiology of nonsyndromic deafness in this population. Methods: A total of 114 unrelated deaf Tibetan children from the Tibet Autonomous Region were enrolled. Five prominent deafness-related genes, GJB2, SLC26A4, GJB6, POU3F4, and mtDNA 12S rRNA, were analyzed. Inner ear development was evaluated by temporal CT. A total of 106 Tibetan hearing normal individuals were included as genetic controls. For radiological comparison, 120 patients, mainly of Han ethnicity, with sensorineural hearing loss were analyzed by temporal CT. Results: None of the Tibetan patients carried diallelic GJB2 or SLC26A4 mutations. Two patients with a history of aminoglycoside usage carried homogeneous mtDNA 12S rRNA A1555G mutation. Two controls were homozygous for 12S rRNA A1555G. There were no mutations in GJB6 or POU3F4. A diagnosis of inner ear malformation was made in 20.18 % of the Tibetan patients and 21.67 % of the Han deaf group. Enlarged vestibular aqueduct, the most common inner ear deformity, was not found in theTibetan patients, but was seen in 18.33 % of the Han patients. Common molecular etiologies

Kinetic and Reactive Distillation for Acrylic Acid Synthesis via Transesterification

Reaction distillation was first used for the process of acrylic acid synthesis through transesterification of methyl acrylate with acetic acid using a strongly acidic cationic exchange resin catalyst (NKC-9). Pseudo-homogeneous (P-H) and Langmuir-Hinshelwood (L-H) heterogeneous kinetic models were presented and fitted with the experimental data obtained from the batch reaction. The key factors of the heterogeneous kinetic model were the four components&#39; adsorption equilibrium constants on the catalyst surface, and they were determined by adsorption experiments. The activity coefficients were calculated using the NRTL method. The catalyst stability was evaluated in a fixed-bed reactor. Catalyst activity showed no obvious decrease after 1000 h of running. A reactive distillation column for acrylic acid synthesis was proposed and designed with process simulation.</p

Ind. Eng. Chem. Res.

Two novel acidic cation-exchange resins, namely, NKC-9 and D072, were first developed to catalyze the esterification of acetic acid with methanol. Kinetics of methyl acetate synthesis are determined by the experiments in a batch reactor at temperatures from 45 to 60 degrees C under atmospheric pressure, with molar ratio of reactants (theta(Bo) = n(methanol):n(acetic acid)) from 0.8 to 1.3. The kinetic data are correlated with the Q-H, E-R, and LHHW and pseudohomogeneous (P-H) models. Then, the reactive distillation process for methyl acetate synthesis is simulated by the Aspen Plus process simulator. Lifetime evaluation of NKC-9 was carried out to study the conversion rate of acetic acid and selectivity of methyl acetate during the long-period running in the fixed-bed reactor. Finally, a series of characterizations such as Fourier transform infrared spectroscopy, X-ray diffraction, and polarizing microscopy were performed to investigate the structure and properties of NKC-9.Two novel acidic cation-exchange resins, namely, NKC-9 and D072, were first developed to catalyze the esterification of acetic acid with methanol. Kinetics of methyl acetate synthesis are determined by the experiments in a batch reactor at temperatures from 45 to 60 degrees C under atmospheric pressure, with molar ratio of reactants (theta(Bo) = n(methanol):n(acetic acid)) from 0.8 to 1.3. The kinetic data are correlated with the Q-H, E-R, and LHHW and pseudohomogeneous (P-H) models. Then, the reactive distillation process for methyl acetate synthesis is simulated by the Aspen Plus process simulator. Lifetime evaluation of NKC-9 was carried out to study the conversion rate of acetic acid and selectivity of methyl acetate during the long-period running in the fixed-bed reactor. Finally, a series of characterizations such as Fourier transform infrared spectroscopy, X-ray diffraction, and polarizing microscopy were performed to investigate the structure and properties of NKC-9

Surface Subsidence Monitoring in Kunming City with Time-Series InSAR and GNSS

Kunming city is located in the middle of Yunnan Province. Due to large-scale groundwater exploitation and urban development in recent years, this area has been affected by surface subsidence. In this paper, Interferometric Synthetic Aperture Radar (InSAR) and Global Navigation Satellite System (GNSS) data are used to monitor the surface subsidence in Kunming city area for better analysis and understanding. The study used data of Sentinel-1A from 2018 to 2020 with atmospheric correction based on GACOS to calculate the average annual subsidence rate in Kunming city area, and the results show that the maximum subsidence rate is 48 mm/year. The subsidence obtained by InSAR is compared with the vertical deformation information obtained by eight GNSS stations in continuous operation in the study area. The subsidence rate trend show by the two methods is consistent, which further verifies the validity of InSAR data to reflect the local deformation. Experimental results shown that the eastern and northeastern Dianchi lake areas were affected by underground resources mining, and the induced surface subsidence characteristics were obvious, with the surface subsidence rate reachde 48 mm/year and 37 mm/year respectively. The Kunyang Phosphate Mine also had different degrees of mining subsidence disaster, with the maximum subsidence rate reached 36 mm/year. The subsidence rate of InSAR and GNSS has the same trend on the whole. However, GNSS sites are generally located in stable areas, the settlement amount obtained in the same time period is somewhat different from that of InSAR

Thermodynamics and Separation Process for Quaternary Acrylic Systems

Vapor-liquid equilibrium (VLE) and liquid-liquid equilibrium (LLE) data of binary and ternary acrylic systems were systematically measured. Subsequently, VLLE phase diagrams of binary systems, tridimensional VLE phase diagrams of methyl acrylate (MA)-methanol (Me)-H2O ternary system, and quaternary LLE phase diagrams of MA-Me-H2O-methyl acetate (MeOAc) system were constructed. These diagrams clearly demonstrated the effects of temperature on phase equilibrium. The experimental data was fitted by the NRTL and UNIQUAC models, and the best-fitted parameters were used to predict interaction properties of ternary and quaternary mixture. Therefore, the phase equilibrium data were provided as reference for the design of acrylic systems rectification or extraction process. Residue curve was mapped out for MA-Me-H2O system through Aspen plus software. Finally, using thermodynamics and residue curve as theoretical basis, two novel separation processes were proposed and applied to the quaternary acrylic systems. (C) 2015 American Institute of Chemical Engineer

Ferrostatin-1 alleviates the damage of C2C12 myoblast and mouse pelvic floor muscle induced by mechanical trauma

Abstract Ferroptosis is a special form of regulated cell death, which is reported to play an important role in a variety of traumatic diseases by promoting lipid peroxidation and devastating cell membrane structure. Pelvic floor dysfunction (PFD) is a kind of disease affecting the quality and health of many women’s lives, which is closely related to the injury of the pelvic floor muscle. Clinical findings have discovered that there is anomalous oxidative damage to the pelvic floor muscle in women with PFD caused by mechanical trauma, but the specific mechanism is still unclear. In this study, we explored the role of ferroptosis-associated oxidative mechanisms in mechanical stretching-induced pelvic floor muscle injury, and whether obesity predisposed pelvic floor muscle to ferroptosis from mechanical injury. Our results, in vitro, showed that mechanical stretch could induce oxidative damage to myoblasts and trigger ferroptosis. In addition, glutathione peroxidase 4 (GPX4) down-regulation and 15-lipoxygenase 1(15LOX-1) up-regulation exhibited the same variational characteristics as ferroptosis, which was much more pronounced in palmitic acid (PA)-treated myoblasts. Furthermore, ferroptosis induced by mechanical stretch could be rescued by ferroptosis inhibitor (ferrostatin-1). More importantly, in vivo, we found that the mitochondria of pelvic floor muscle shrank, which were consistent with the mitochondrial morphology of ferroptosis, and GPX4 and 15LOX-1 showed the same change observed in cells. In conclusion, our data suggest ferroptosis is involved in the injury of the pelvic floor muscle caused by mechanical stretching, and provide a novel insight for PFD therapy