Microwave-assisted Acid-catalyzed Hydrolysis of Hemicelluloses in Rice Husk into Xylose

The development of an environmentally benign process for the hydrolysis of hemicelluloses into xylose could be one of the key technologies for making full use of biomass in the future. This paper studies dilute acid hydrolysis of hemicelluloses in rice husk (RH) into xylose using microwave radiation. Fourier transform infrared-attenuated total reflection spectroscopy was employed to quantitatively analyze xylose. The influences of hydrolysis parameters such as temperature, time, acid concentration, and ratio of RH to sulfuric acid on the yield of xylose in acid hydrolysis of RH were also investigated. The optimum hydrolysis conditions of hemicelluloses in RH to xylose are as follows: 4 wt% of H2SO4 concentration, 150 °C hydrolysis temperature, 25 min reaction time, and 1:7 ratio of RH (g) to H2SO4 (mL). Under optimum hydrolysis conditions, a yield of 32.96% xylose is obtained

Pretreatment of lignocellulosic wheat straw in ethanolwater co-solvents

Pretreatment is the key process for lignocellulosic biomass conversion, which is necessary to alter the structure of biomass to make cellulose and hemicellulose more accessible to the enzymes that convert the carbohydrate polymers into fermentable sugars. The present study reports the use of 15 ml ethanol-water co-solvents (1:1, v/v) for the pretreatment of lignocellulosic biomass (1.5 g) to produce cellulosic residual solid under varying conditions of temperature (220-310 °C) and time (20-100 min). Kinetic analysis was performed to examine the decomposition behavior of biomass in the co-solvents. The results showed that the optimal conditions for the pretreatment were 250 °C and 40 min. The maximum yield of residual solid under the optimized pretreatment conditions was 49.6% (0.744 g), which consisted of 91.4% holocellulose (cellulose and hemicellulose). Microstructure analysis showed that the compact monolithic structure of biomass had decomposed into a loose filamentous structure

Does high-speed railway affect the cost behavior of tourism firms? Evidence from China

Cost stickiness, which is also termed cost asymmetry, describes the asymmetric relationship between revenue and cost. In this study, we examine whether high-speed railway (HSR) connection affects the cost stickiness of tourism firms. Employing a sample of 324 Chinese tourism firms from 2003 to 2018 and applying a difference-in-difference (DID) method, we find that the cost stickiness of tourism firms increases after HSR connection. Our results also reveal that the relationship between HSR connection and cost stickiness is more pronounced in firms with higher free cash flow (FCF), higher labor costs, and in state-owned enterprises (SOEs). Our research advances an indepth understanding of the cost behavior in tourism firms and sheds light on the policy effect of HSR connection

FCP-Net: A Feature-Compression-Pyramid Network Guided by Game-Theoretic Interactions for Medical Image Segmentation

Medical image segmentation is a crucial step in diagnosis and analysis of diseases for clinical applications. Deep neural network methods such as DeepLabv3+ have successfully been applied for medical image segmentation, but multi-level features are seldom integrated seamlessly into different attention mechanisms, and few studies have explored the interactions between medical image segmentation and classification tasks. Herein, we propose a feature-compression-pyramid network (FCP-Net) guided by game-theoretic interactions with a hybrid loss function (HLF) for the medical image segmentation. The proposed approach consists of segmentation branch, classification branch and interaction branch. In the encoding stage, a new strategy is developed for the segmentation branch by applying three modules, e.g., embedded feature ensemble, dilated spatial mapping and channel attention (DSMCA), and branch layer fusion. These modules allow effective extraction of spatial information, efficient identification of spatial correlation among various features, and fully integration of multireceptive field features from different branches. In the decoding stage, a DSMCA module and a multi-scale feature fusion module are used to establish multiple skip connections for enhancing fusion features. Classification and interaction branches are introduced to explore the potential benefits of the classification information task to the segmentation task. We further explore the interactions of segmentation and classification branches from a game theoretic view, and design an HLF. Based on this HLF, the segmentation, classification and interaction branches can collaboratively learn and teach each other throughout the training process, thus applying the conjoint information between the segmentation and classification tasks and improving the generalization performance. The proposed model has been evaluated using several datasets, including ISIC2017, ISIC2018, REFUGE, Kvasir-SEG, BUSI, and PH2, and the results prove its competitiveness compared with other state-of-the-art techniques

Correlation between inflammatory marker and lipid metabolism in patients with uterine leiomyomas

IntroductionObesity is a risk factor for the development of uterine leiomyoma (UL), and the inflammatory response plays a key role in the pathogenesis of UL. Our objective was to assess whether there was an independent relationship between inflammatory markers and triglycerides (TG) in patients with UL.Methods1,477 UL participants who were hospitalized at the Jining Medical University between January 2016 and December 2022 were included in this cross-sectional study. The independent and dependent variables measured at baseline were inflammatory markers and TG levels, respectively. The covariates were age, body mass index (BMI), UL and menstrual status. Based on the number of fibroids, the study population was divided into Single-group and Multiple-group.ResultsUnivariate and multiple regression analyses and stratified analyses revealed significant positive correlations between neutrophil-lymphocyte ratio and systemic immune inflammation index and TG, and significant negative correlations between monocyte-lymphocyte ratio and TG.ConclusionThe findings show a significant correlation between the inflammatory response and lipid metabolism levels in UL patients. This provides direction for further research into the pathophysiology of UL and also helps to formulate hypotheses for predictive models of UL

Preparation and characterisation of Al-doped ZnO and PVDF composites

A single organic composite material having high dielectric constant is difficult to meet the needs of the market. Nowadays, polymer matrix-based composites have become a promising option that researchers are focusing on. Al-doped zinc oxide (ZnO) and composites containing ZnO as reinforcement and poly(vinylidene fluoride) (PVDF) as matrix were prepared. The microstructure of composites was analysed by scanning electron microscope and transmission electron microscopy techniques. The chemical structures and crystallisation behaviour of the materials were investigated by the means of FT-IR and X-ray diffractometer. ZnO, having both rod- and sheet-shaped, was evenly distributed within the PVDF material. Additionally, the dielectric properties and breakdown field strength of composite were tested. As the content of the fillers was kept steady, the dielectric constant of the composite material increased proportionally with the Al content. Thus, a composite containing 10% ZnO with 7% Al displayed a dielectric constant of 18.5 at 100 Hz, twice when compared with the pure ZnO/PVDF composites. This phenomenon was attributed to ZnO semiconductor properties which can significantly improve the conductive nature of the materials

Analyzing Indicators Affecting Commercial Property Value in Metro Station Accessible Area Using Walking Time Consumption: Case of Xi’an, China

In studies investigating the property value enhancements along metro lines, study ranges in most cases are measured in Euclidean distance. However, city roads are not always straight, and Euclidean distance sometimes does not equal to actual distance the passenger travels from the public transport station to their home or a commercial spot. To solve this problem, this study analyzed the indicators affecting commercial property value in metro station accessible area in Xi’an, using walking time consumption in measuring the study range. Following a conceptual framework, considering empirical evidences in related studies, information in city structure, and metro distribution, the initial indicator set is built. Using hedonic price model (HPM), spatial autoregressive model (SAR), and error term (SEM), significant indicators affecting commercial property value are investigated. In this study, 14 significant indicators are determined and quantified. Threshold distance equals to 900 m is found to be appropriate in addressing the autocorrelation problem with the weighted decision matrix tool. Compared to HPM and SEM, SAR is found to perform the best in evaluating the significant indicators with the largest R2 (0.415) and the lowest Akaike Info Criterion (AIC) (−395.214). Besides, it is discovered that the value of the commercial property lies in the study range of 20 min walking time and is obviously influenced by the metro station. The results discovered in this study could provide some empirical evidences to commercial property planning in Xi’an