Comparison of the Degradation Performance of Seven Different Choline Chloride-Based DES Systems on Alkaline Lignin.

Lignin is a natural polymer second only to cellulose in natural reserves, whose structure is an aromatic macromolecule composed of benzene propane monomers connected by chemical bonds such as carbon-carbon bonds and ether bonds. Degradation is one of the ways to achieve the high-value conversion of lignin, among which the heating degradation of lignin by deep eutectic solvent (DES) can be an excellent green degradation method. In this study, choline chloride (CC) was used as the hydrogen bond acceptor, and urea (UR), ethylene glycol (GC), glycerol (GE), acetic acid (AA), formic and acetic mixed acid (MA), oxalic acid (OX), and p-toluenesulfonic acid (TA) were used as hydrogen bond donors to degrade lignin. NMR hydrogen spectroscopy was used for the simple and rapid determination of phenolic hydroxyl groups in lignin. FT-IR spectroscopy was used to characterize the changes of functional groups of lignin during DES treatment. GPC observed the molecular weight of lignin after degradation and found a significant increase in the homogeneity (1.6-2.0) and a significant decrease in the molecular weight Mw (2478-4330) of the regenerated lignin. It was found that acidic DES was more effective in depolymerizing alkaline lignin, especially for the toluene-choline chloride. Seven DES solutions were recovered, and it was found that the recovery of DES still reached more than 80% at the first recovery.

Automatic Segmentation of Lumbar Spine MRI Images Based on Improved Attention U-Net.

Lumbar spine segmentation is important to help doctors diagnose lumbar disc herniation (LDH) and patients' rehabilitation treatment. In order to accurately segment the lumbar spine, a lumbar spine image segmentation algorithm based on improved Attention U-Net is proposed. The algorithm is based on Attention U-Net, the attention module based on multilevel feature map fusion is adopted, two residual modules are introduced instead of the original convolution blocks. a hybrid loss function is used for prediction during the training process, and finally, the image superposition process is realized. In this experiment, we expanded 420 lumbar MRI images of 180 patients to 1000 images and trained them by different algorithms, respectively, and accuracy, recall, and Dice similarity coefficient metrics were used to analyze these algorithms. The results show that compared with SVM, FCN, R-CNN, U-Net, and Attention U-Net models, the improved model achieved better results in all three evaluations, with 95.50%, 94.53%, and 95.01%, respectively, which proves the better performance of the proposed method for segmentation in lumbar disc and caudal vertebrae.

MRI-Based Medical Image Recognition: Identification and Diagnosis of LDH.

To realize the automatic symptom recognition and classification of MR images and improve the accuracy and efficiency of the diagnosis of lumbar intervertebral disc herniation (LDH), a method for lumbar intervertebral disc recognition and disease classification is proposed in this paper. The method mainly includes three steps: preprocessing, target segmentation, and symptom classification. Preprocessing is performed by noise reduction and interference removal methods for blurred images. The contour poles are used to determine the four points of the tail vertebra in order to reduce the wrong segmentation of the tail vertebra. A classification method based on five judgment indicators is proposed, which effectively improves the stability of disease diagnosis. The example verifies that the algorithm can accurately complete the target segmentation and the accuracy of symptom classification reaches the standard of professional doctors, which proves that the method has good robustness.

The complete mitochondrial genome of snailfish Liparis tanakae Gilbert & Burke, 1912 (Perciformes: Cottioidei: Liparidae).

Mitochondrial genome is maternal inheritance that provides higher resolution in taxonomic and phylogenetic research. The absence of complete mitogenome becomes an obstacle to further research. Here, we reported the complete mitogenome of Liparis tanakae Gilbert & Burke, 1912 (Perciformes: Cottioidei: Liparidae), which has a length of 17,860 bp. It comprised 39 genes, including 13 protein-coding genes (PCGs), 23 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs), and 1 control region (D-loop). The 23 tRNAs in this mitogenome included two tRNA-Ala genes on the light strand. Maximum-likelihood (ML) phylogenetic analysis based on 14 available mitogenomes of 10 species in suborder Cottioidei confirmed L. tanakae as monophyletic with other snailfishes. This study would provide important genetic resources and could be useful for evolutionary analysis.

Review on the preparation of fuels and chemicals based on lignin.

Lignin is by far the most abundant natural renewable aromatic polymer in nature, and its reserves are second only to cellulose. In addition to the rich carbon content, the structure of lignin contains functional groups such as benzene rings, methoxyl groups, and phenolic hydroxyl groups. Lignin degradation has become one of the high value, high quality and high efficiency methods to convert lignin, which is of great significance to alleviating the current energy shortage and environmental crisis. This article introduces the hydrolysis methods of lignin in acidic, alkaline, ionic liquids and supercritical fluids, reviews the heating rate, the source of lignin species and the effects of heating rate on the pyrolysis of lignin, and briefly describes the metal catalysis, oxidation methods such as electrochemical degradation and photocatalytic oxidation, and degradation reduction methods using hydrogen and hydrogen supply reagents. The lignin degradation methods for the preparation of fuels and chemicals are systematically summarized. The advantages and disadvantages of different methods, the selectivity under different conditions and the degradation efficiency of different catalytic combination systems are compared. In this paper, a new approach to improve the degradation efficiency is envisioned in order to contribute to the efficient utilization and high value conversion of lignin.

Assessing the Security of Campus Networks: The Case of Seven Universities.

The network security situation of campus networks on CERNET (China Education and Research Network) has received great concern. However, most network managers have no complete picture of the network security because of its special management and the rapid growth of network assets. In this investigation, the security of campus networks belonging to seven universities in Wuhan was investigated. A tool called "WebHunt" was designed for campus networks, and with its help, the network security risks were found. Differently from existing tools for network probing, WebHunt can adopt the network scale and special rules of the campus network. According to the characteristics of campus websites, a series of functions were integrated into WebHunt, including reverse resolution of domain names, active network detection and fingerprint identification for software assets. Besides, WebHunt builds its vulnerability intelligence database with a knowledge graph structure and locates the vulnerabilities through matching knowledge graph information. Security assessments of seven universities presents WebHunt's applicability for campus networks. Besides, it also shows that many security risks are concealed in campus networks, such as non-compliance IP addresses and domain names, system vulnerabilities and so on. The security reports containing risks have been sent to the relevant universities, and positive feedback was received.

Enhanced transformation of phosphorus (P) in sewage sludge to hydroxyapatite via hydrothermal carbonization and calcium-based additive.

Phosphorus (P) recovery from sewage sludge is one of the promising substitutes to the phosphate ores to alleviate the shortage of P supply in the future. In this study, how hydrothermal carbonization (HTC) temperature functioned in the migration and transformation of P from sewage sludge during HTC process was clarified. The enhancement effect of Ca-based additive on the transformation of P to hydroxyapatite via HTC was systematically studied. Additionally, leaching characteristics of P in the hydrochars with Ca-based additive were analyzed to assess their P-bioavailability. Results indicated that favoring by increased pH in the process water, HTC temperature played a significant role in the migration and transformation of P during HTC. Therefore, higher HTC temperature was beneficial for P enrichment and transformation to apatite phosphorus in the hydrochars. Both alkaline environment and existence of sufficient calcium ions were essential for enhanced formation of apatite phosphorus during HTC. Adding CaO could stimulate almost complete transformation of non-apatite inorganic phosphorus to apatite phosphorus such as hydroxyapatite, causing a maximum increase of apatite phosphorus by 252%. Concurrently, P-bioavailability by 2% (w/w) formic acid extraction of the hydrochars increased by 233% at CaO = 4%. These findings were confirmed by XRD analyses. Ca-associated apatite phosphorus such as Ca5(PO4)3OH and Ca2P2O7 âˆ™ 2H2O, was detected in the hydrochars. With the assistance of thermochemical calculation, transformation pathways of P after CaO addition have been proposed, which coincided with our experimental results well. The stable P-containing minerals of hydroxyapatite (Ca5(PO4)3OH) was calculated at equilibrium state.

A comparative study on droplet characteristics and specific charge of ethanol in two small-scale electrospray systems.

An investigation on the droplet characteristics of ethanol in small-scale combustors with two different systems was conducted experimentally and theoretically. The classical capillary-mesh electrode arrangement was applied in Type A electrospray system, and for Type B, an additional ring electrode is included. The droplet size and velocity were measured by a Phase Doppler Anemometer. The electric filed intensity was theoretically calculated in the two electrospray systems. Compared with Type A, Type B system has smaller droplet size and velocity in the same spraying mode. Meanwhile the electrospray process in Type B system is more stable than that in Type A with its smaller root mean square velocity. By measuring the spraying current, the average specific charge of the droplets for the two systems was obtained in different spraying modes. And it was found that the addition of the ring electrode can help to increase the droplet charge, which is the fundamental reason for Type B electrospray system to perform better. The corona charge of the droplets was theoretically calculated for the two electrospray systems. It was found that the calculated specific charge generated by corona charging was in good agreement with the experimental results.