Curv-Net: Curvilinear structure segmentation network based on selective kernel and multi-Bi-ConvLSTM.

PURPOSE: Accurately segmenting curvilinear structures, for example, retinal blood vessels or nerve fibers, in the medical image is essential to the clinical diagnosis of many diseases. Recently, deep learning has become a popular technology to deal with the image segmentation task, and it has obtained remarkable achievement. However, the existing methods still have many problems when segmenting the curvilinear structures in medical images, such as losing the details of curvilinear structures, producing many false-positive segmentation results. To mitigate these problems, we propose a novel end-to-end curvilinear structure segmentation network called Curv-Net. METHODS: Curv-Net is an effective encoder-decoder architecture constructed based on selective kernel (SK) and multibidirectional convolutional LSTM (multi-Bi-ConvLSTM). To be specific, we first employ the SK module in the convolutional layer to adaptively extract the multi-scale features of the input image, and then we design a multi-Bi-ConvLSTM as the skip concatenation to fuse the information learned in the same stage and propagate the feature information from the deep stages to the shallow stages, which can enable the feature captured by Curv-Net to contain more detail information and high-level semantic information simultaneously to improve the segmentation performance. RESULTS: The effectiveness and reliability of our proposed Curv-Net are verified on three public datasets: two color fundus datasets (DRIVE and CHASE_DB1) and one corneal nerve fiber dataset (CCM-2). We calculate the accuracy (ACC), sensitivity (SE), specificity (SP), Dice similarity coefficient (Dice), and area under the receiver (AUC) for the DRIVE and CHASE_DB1 datasets. The ACC, SE, SP, Dice, and AUC of the DRIVE dataset are 0.9629, 0.8175, 0.9858, 0.8352, and 0.9810, respectively. For the CHASE_DB1 dataset, the values are 0.9810, 0.8564, 0.9899, 0.8143, and 0.9832, respectively. To validate the corneal nerve fiber segmentation performance of the proposed Curv-Net, we test it on the CCM-2 dataset and calculate Dice, SE, and false discovery rate (FDR) metrics. The Dice, SE, and FDR achieved by Curv-Net are 0.8114 ± 0.0062, 0.8903 ± 0.0113, and 0.2547 ± 0.0104, respectively. CONCLUSIONS: Curv-Net is evaluated on three public datasets. Extensive experimental results demonstrate that Curv-Net outperforms the other superior curvilinear structure segmentation methods.

[Evaluating the Significance of Odor Gas Released During the Directly Drying Process of Sludge: Based on the Multi-index Integrated Assessment Method].

Co-processing of sewage sludge using the cement kiln can realize sludge harmless treatment, quantity reduction, stabilization and reutilization. The moisture content should be reduced to below 30% to meet the requirement of combustion. Thermal drying is an effective way for sludge desiccation. Odors and volatile organic compounds are generated and released during the sludge drying process, which could lead to odor pollution. The main odor pollutants were selected by the multi-index integrated assessment method. The concentration, olfactory threshold, threshold limit value, smell security level and saturated vapor pressure were considered as indexes based on the related regulations in China and foreign countries. Taking the pollution potential as the evaluation target, and the risk index and odor emission intensity as evaluation indexes, the odor pollution potential rated evaluation model of the pollutants was built according to the Weber-Fechner law. The aim of the present study is to form the rating evaluation method of odor potential pollution capacity suitable for the directly drying process of sludge.

[Treatment of Flue Gas from Sludge Drying Process by A Thermophilic Biofilter].

A thermophilic biofilter was employed to treat the flue gas generated from sludge drying process, and the performance in both the start period and the stationary phase was studied under the gas flow rate of 2 700-3 100 m3 x h(-1) and retention time of 21.88-25.10 s. The results showed that the thermophilic biofilter could effectively treat gases containing sulfur dioxide, ammonia and volatile organic compounds (VOC). The removal efficiencies could reach 100%, 93.61% and 87.01%, respectively. Microbial analysis indicated that most of the population belonged to thermophilic bacteria. Paenibacillus sp., Chelatococcus sp., Bacillus sp., Clostridium thermosuccinogenes, Pseudoxanthomonas sp. and Geobacillus debilis which were abundant in the thermophilic biofilter, had the abilities of denitrification, desulfurization and degradation of volatile organic compounds.

[Characteristics of odors and VOCs from sludge direct drying process].

Co-processing sewage sludge by using the high-temperature feature of cement kiln can realize harmless disposal and energy recycling. In this paper, investigation on characteristics of the flue gas from sludge drying process was carried out in Guangzhou Heidelberg Yuexiu Cement Co., LTD. The composition and the main source of odors and volatile organic compounds (VOCs) emitted during the drying process were analyzed, aimed to provide scientific basis for the treatment of sewage sludge. Results showed that there were a large number of malodorous substances and VOCs in the flue gas. Sulfur dioxide and other sulfur-containing compounds were the main components in the malodorous substances, while benzene derivatives were predominant in VOCs. The compositions of odors and VOCs were influenced by the characteristics of the sludge and the heat medium (kiln tail gas). Total organic compounds in the sludge were significantly decreased after drying. Other organic substances such as volatile fatty acid, protein, and polysaccharide were also obviously reduced. The organic matter in sludge was the main source of VOCs in the flue gas. Part of sulfurous substances, such as sulfur dioxide, carbon disulfide, were from sulfur-containing substances in the sludge, and the rest were from the kiln tail gas itself.

Effects of visfatin gene polymorphism RS4730153 on exercise-induced weight loss of obese children and adolescents of Han Chinese.

Visfatin is a recently discovered adipokine that contributes to glucose and obesity-related conditions. This study investigates Visfatin RS4730153 polymorphism from the perspectives of its relations with glucose/lipid metabolism and its influence on the effects of exercise-induced weight loss. Eighty-eight obese Han Chinese children and adolescents were randomly selected from a 2008 Shanghai Weight Loss Summer Camp and were supervised to complete a 4 week aerobic exercise training program. Significant differences were observed in before-exercise TG value and exercise-induced HOMA-ß change, with the AG group having a much higher TG value than the GG group (P ≤ 0.05), and the latter exhibiting a significantly larger before-and-after exercise HOMA-ß change than the former (P ≤ 0.05). However, no significant difference was observed between the two groups in before exercise indices of body shape, function and quality, nor in exercise-induced changes of body shape, function, and quality. Findings suggest that Visfatin RS4730153 homozygous GG genotype may effect adjustment of glucose and lipid metabolism in obese children and adolescents by reducing TG levels and increasing insulin sensitivity to exercise.

[Donor site selection and clinical evaluation].

OBJECTIVE: To explore the principles of donor site selection for defects of the hypopharynx and/or cervical-esophagus based on a novel defect classification system and treatment outcome of this series. METHOD: Thirty-nine patients underwent reconstruction of their defects of the hypopharynx and/or cervical-esophagus from January 2007 to June 2012 were retrospectively studied. 23 hypopharngeal and/or cervical-esophageal defects were circumferential or near circumferential (group A), 16 were partial(group B). 22 patients had compromised neck vascular status, while the other 17 patients had normal neck vascular status. Selection of the donor sites was based on extent of the defects and neck vascular status. Donor sites for reconstruction of the defects of group A included anterolateral thigh flap (n = 8), gastric pull-up (n = 6), radial forearm flap (n = 3), jejunum flap (n = 3), and pectoralis major myocutaneous flap (n = 3). For goup B, Infrahyoid myocutaceous flaps, radial forearm flaps, and pectoralis major myocutaneous flaps were used in 8, 3, and 5 cases, respectively. Flap survival, surgical complications, function outcome, and tumor control were observed. RESULT: Overall complication rate was 12.8% (5/39) in this series. In group A, three flap necroses occurred in jejunum flap (n = 1), anterolateral thigh flap (n = 1), and pectoralis major flap (n = 1). All these flap necroses occurred in the compromised neck vascular status group. One case of pharyngeal fistula without flap necrosis occurred in Group B. All except 2 patients restored oral intake postoperatively; 16 patients with laryngeal preservation had good phonation postoperatively. 2-year and 3-year survival of this series were 72.1% and 65.2%, respectively. CONCLUSION: Selection of an appropriate donor site for reconstruction of the defects of hypopharynx and /or cervical-esophagus should be based on the extent of the defects, neck vascular status, and clinical features of the flap. Individualized donor site selection for hypopharyngeal and cervical esophageal defects reconstruction can result in good clinical outcome.

[Effects of visfatin gene polymorphisms on glycolipid metabolism and exercise-induced weight reduction in obesity].

Visfatin, also named nicotinamide phosphoribosyl transferase (NAMPT), is a cytokine secreted from adipose tissue. Visfatin can regulate immune action and is involved in the NAD+ salvage pathway. In addition, recent researches have shown that visfatin helps the regulation of glucose and lipid metabolism, especially in exercise-induced weight reduction for obesity. The aim of this review is to provide an overview of the contribution of visfatin gene polymorphisms to glucose and lipid metabolism and exercise-induced weight reduction in obesity.