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Electrocardiography (ECG) is the gold standard for monitoring vital signs and for diagnosing, controlling, and preventing cardiovascular diseases (CVDs). However, ECG requires continuous user participation, and cannot be used for continuous cardiac monitoring. In contrast to ECG, photoplethysmography (PPG) devices do not require continued user involvement, and can offer ongoing and long-term detection capabilities. However, from a medical perspective, ECG can provide more information about the heart. Currently, most existing work contains different signals recorded from the same subject in training and test sets. This study proposes a neural network model based on a 1D convolutional neural network (CNN) and a bidirectional long short-term memory (BiLSTM) network. This neural network model can directly reconstruct ECG signals from PPG signals. The learned features are captured from the CNN model and fed into the BiLSTM model. In order to verify the validity of the model, it is evaluated using the MIMIC II dataset in the completely subject-independent model (records are placed in a training set, and a test set appears once, but the test signal belongs to a record that is not in the training set). The Pearson's correlation coefficient between the reconstructed ECG and the reference ECG of the proposed model is 0.963 in the completely subject-independence model. The results of the proposed model are better than those of several cited state-of-the-art models. The results of our trained model indicate that we can obtain reconstructed ECGs that are highly similar to reference ECGs in the completely subject-independent model. [ABSTRACT FROM AUTHOR]

The current high-salinity wastewater treatment technology is complex, costly, and carries the risk of secondary contamination. As a traditional desalination technology, the combined method using frozen technology has broad development prospects in wastewater treatment. This study investigates the desalination effects of waste leachate using three different methods: the frozen–gravity method (FGM), frozen–centrifugal method (FCM), and frozen–blowing methods (FBMs), under various experimental conditions. The results showed that the salt rejection of all three methods could reach more than 75% under the conditions of a freezing time of 12 h, freezing temperature of −15 °C, and ice production rate of 40%; the salt rejection of FGM increased at higher ambient temperatures, but it was not conducive to the removal of organic pollutants; the salt rejection of FCM was sensitive to the centrifugal time and centrifugal speed, with a significant correlation (p < 0.05), the increase in centrifugal time and centrifugal speed can help to improve the salt rejection, and the increase in centrifugal speed in the range of 1000–2000 rpm can accelerate the discharge of concentrated brine more effectively; the frozen–crushed–blowing method (FCBM) in FBM has a salt rejection as high as 93.86% at an ice production rate of 25.80%, which reduces the salinity of the effluent from 4.07% to 0.25%, speeds up the desalination process, and improves the salt rejection compared to the other methods. This study provides a new perspective and reference for the treatment of high-saline wastewater. [ABSTRACT FROM AUTHOR]

In order to probe into the mechanism of solvolysis (alcoholysis/hydrolysis) of propylene oxide (PO), the formation of propylene glycol (PG), 1-methoxy-2-propanol (PPM) and 2-methoxy-1-propanol (SPM) over the TS-1 catalyst with tetrahedral Ti and Ti/defect sites was systematically discussed using an embedded quantum mechanical/molecular mechanics (QM/MM) approach. The results showed that the activity of PO solvolysis is closely related to the ring-opening ability of active substances, and the ring-opening ability is in the following order: Si–O(H)–Ti > Ti–OH > 5MR Ti–OOH > Ti–OCH3 (tetrahedral Ti site); 3MR Ti–OOH > Ti–OH > 5MR Ti–OOH > Ti–OCH3 (Ti/defect site). At the tetrahedral site, the concerted mechanism is the dominant pathway for PO ring opening to form PPM, while a competitive relationship exists between stepwise and concerted mechanisms to form PG and SPM. Si–O(H)–Ti exhibits excellent PO ring-opening activity because of its strong Brønsted acidity, but it is difficult to form. At the Ti/defect site, the stepwise mechanism via PO ring opening with 3MR Ti–OOH and then successive hydrolysis/alcoholysis to form product is the dominant pathway. The overall energy barrier of the optimal route is relatively lower as compared to the tetrahedral Ti site. This work opens up a new path for providing more information on the detailed mechanism in the solvolysis of PO over the TS-1 catalyst from a theoretical point of view. [ABSTRACT FROM AUTHOR]

Propylene glycol methyl ether was directly synthesized from propylene and hydrogen peroxide under mild conditions via aluminum modified titanium silicalite-1 as a bifunctional catalyst. It has both active sites capable of epoxidation and active sites capable of ring opening reactions, thus realizing the one-pot preparation of propylene glycol methyl ether by propylene. The synergistic effect of Ti–Al on the catalytic performance and the distribution of propylene glycol methyl ether isomer were investigated in detail, and the synergistic catalysis between the two active sites was characterized. The gradual introduction of aluminum reduced the activation ability for hydrogen peroxide, but gradually increased the selectivity for propylene glycol methyl ether. Under the optimum conditions, the selectivity for propylene glycol methyl ether reached 91.53%. Combined with Density Functional Theory (DFT) calculations, the synergistic catalytic effect of doped Al and framework Ti in titanium silicalite-1 is discussed in detail from a microscopic perspective. Al increases the Lewis acid strength of Ti active sites and promotes the conversion of propylene to propylene oxide (PO), and simultaneously Ti increases the Brønsted acid strength of Al active sites and promotes the conversion of propylene oxide to propylene glycol ether. [ABSTRACT FROM AUTHOR]

Objective: To study the clinicopathologic features of tuberous sclerosis complex (TSC)., Methods: The clinicopathologic data of the patients diagnosed as TSC with refractory epilepsy and resection of epileptic focus were retrospectively analyzed., Results: Fourteen cases were included, the mean age was (15.8±12.9) years, with a male predominance (male to female ratio=10:4). Frontal lobe was the most common (13/14) site of involvement. MRI showed multiple patchy long T1 and long T2 signals. CT images showed multiple subependymal high density calcified nodules in nine cases. Histology showed mild to severe disruption of the cortical lamination, cortical and subcortical tubers with giant cells and/or dysmorphic neurons. The giant cells showed strong immunoreactivity for vimentin and nestin, while the dysmorphic neurons partially expressed MAP2 and NF. Vimentin also stained strongly the "reactive" astrocytes. Thirteen cases had follow-up information: Engel class I in six cases, Engel class II in six cases, and Engel class III in one case., Conclusions: Diagnosis of TSC relies on combined pathologic, clinical and neuroradiological features. Immunohistochemical staining can be helpful. Resection of epileptic focus is an effective method to treat refractory epilepsy in TSC.