58 research outputs found
The infrared radiation and vacuum assisted drying kinetics of flue-cured tobacco leaf and its drying quality analysis
[EN] Dehydration is widely involved in tobacco processing such as tobacco leaf curing, tobacco trip redrying and cut tobacco drying, which plays a key role due to its effect on the physical and chemical quality of tobacco. The current drying methods in tobacco processing mainly use heat conduction, heat convection or their combination to dehydrate tobacco materials. However, radiation heat transfer as one of basic heat transferways has not been investigated in the tobacco drying. In the present work, infrared radiation dryer was designed to explore the tobacco infrared radiation drying characteristics. The effect of radiation heat transfer conditions and vacuum on the drying kinetics and temperature of tobacco leaves was investigated. Diffusion coefficient of middle tobacco leaves C2F is between 0.848×10-10 ~ 1.597×10-10 m2/s. At the same time, the pore structure andpetroleum ether tobacco extracts in dried tobacco were also analyzed in order to explore the different effects of infrared radiation drying and traditional drying technology on tobacco quality.Zhu, W.; Guo, G.; Liu, C.; Cheng, L.; Wang, L. (2018). The infrared radiation and vacuum assisted drying kinetics of flue-cured tobacco leaf and its drying quality analysis. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 919-925. https://doi.org/10.4995/IDS2018.2018.7612OCS91992
Alterations of Gut Microbiota in Cholestatic Infants and Their Correlation With Hepatic Function
Cholestasis is a major hepatic disease in infants, with increasing morbidity in recent years. Accumulating evidence has revealed that the gut microbiota (GM) is associated with liver diseases, such as non-alcoholic steatohepatitis, cirrhosis, and hepatocellular carcinoma. However, GM alterations in cholestatic infants and the correlation between the GM and hepatic functions remain uninvestigated. In this study, 43 cholestatic infants (IC group) and 37 healthy infants (H group) were enrolled to detect GM discrepancies using 16S rDNA analysis. The diversity in the bacterial community was significantly lower in the IC group than that in the H group (P = 0.013). After determining the top 10 abundant genera of microbes in the IC and H groups, we found that 13 of them were differentially enriched, including Bifidobacterium, Bacteroides, Streptococcus, Enterococcus, and Staphylococcus. As compared with the H group, the IC group had a more complex GM co-occurrence network featured by three core nodes: Phyllobacterium, Ruminococcus, and Anaerostipes. In addition, the positive correlation between Faecalibacterium and Erysipelatoclostridium (r = 0.689, P = 0.000, FDR = 0.009) was not observed in the IC patients. Using the GM composition, the cholestatic patients can be distinguished from healthy infants with high accuracy [areas under receiver operating curve (AUC) > 0.97], wherein Rothia, Eggerthella, Phyllobacterium, and Blautia are identified as valuable biomarkers. Using KEGG annotation, we identified 32 functional categories with significant difference in enrichment of the GM of IC patients, including IC-enriched functional categories that were related to lipid metabolism, biodegradation and metabolism of xenobiotics, and various diseases. In contrast, the number of functions associated with amino acid metabolism, nucleotide metabolism, and vitamins metabolism was reduced in the IC patients. We also identified significant correlation between GM composition and indicators of hepatic function. Megasphaera positively correlated with total bilirubin (r = 0.455, P = 0.002) and direct bilirubin (r = 0.441, P = 0.003), whereas γ-glutamyl transpeptidase was positively associated with Parasutterella (r = 0.466, P = 0.002) and negatively related to Streptococcus (r = -0.450, P = 0.003). This study describes the GM characteristics in the cholestatic infants, illustrates the association between the GM components and the hepatic function, and provides a solid theoretical basis for GM intervention for the treatment of infantile cholestasis
Evaluation of PCR on Bronchoalveolar Lavage Fluid for Diagnosis of Invasive Aspergillosis: A Bivariate Metaanalysis and Systematic Review
BACKGROUND: Nucleic acid detection by polymerase chain reaction (PCR) is emerging as a sensitive and rapid diagnostic tool. PCR assays on serum have the potential to be a practical diagnostic tool. However, PCR on bronchoalveolar lavage fluid (BALF) has not been well established. We performed a systematic review of published studies to evaluate the diagnostic accuracy of PCR assays on BALF for invasive aspergillosis (IA). METHODS: Relevant published studies were shortlisted to evaluate the quality of their methodologies. A bivariate regression approach was used to calculate pooled values of the method sensitivity, specificity, and positive and negative likelihood ratios. Hierarchical summary receiver operating characteristic curves were used to summarize overall performance. We calculated the post-test probability to evaluate clinical usefulness. Potential heterogeneity among studies was explored by subgroup analyses. RESULTS: Seventeen studies comprising 1191 at-risk patients were selected. The summary estimates of the BALF-PCR assay for proven and probable IA were as follows: sensitivity, 0.91 (95% confidence interval (CI), 0.79-0.96); specificity, 0.92 (95% CI, 0.87-0.96); positive likelihood ratio, 11.90 (95% CI, 6.80-20.80); and negative likelihood ratio, 0.10 (95% CI, 0.04-0.24). Subgroup analyses showed that the performance of the PCR assay was influenced by PCR assay methodology, primer design and the methods of cell wall disruption and DNA extraction. CONCLUSIONS: PCR assay on BALF is highly accurate for diagnosing IA in immunocompromised patients and is likely to be a useful diagnostic tool. However, further efforts towards devising a standard protocol are needed to enable formal validation of BALF-PCR
The Genome of Ganderma lucidum Provide Insights into Triterpense Biosynthesis and Wood Degradation
BACKGROUND: Ganoderma lucidum (Reishi or Ling Zhi) is one of the most famous Traditional Chinese Medicines and has been widely used in the treatment of various human diseases in Asia countries. It is also a fungus with strong wood degradation ability with potential in bioenergy production. However, genes, pathways and mechanisms of these functions are still unknown. METHODOLOGY/PRINCIPAL FINDINGS: The genome of G. lucidum was sequenced and assembled into a 39.9 megabases (Mb) draft genome, which encoded 12,080 protein-coding genes and ∼83% of them were similar to public sequences. We performed comprehensive annotation for G. lucidum genes and made comparisons with genes in other fungi genomes. Genes in the biosynthesis of the main G. lucidum active ingredients, ganoderic acids (GAs), were characterized. Among the GAs synthases, we identified a fusion gene, the N and C terminal of which are homologous to two different enzymes. Moreover, the fusion gene was only found in basidiomycetes. As a white rot fungus with wood degradation ability, abundant carbohydrate-active enzymes and ligninolytic enzymes were identified in the G. lucidum genome and were compared with other fungi. CONCLUSIONS/SIGNIFICANCE: The genome sequence and well annotation of G. lucidum will provide new insights in function analyses including its medicinal mechanism. The characterization of genes in the triterpene biosynthesis and wood degradation will facilitate bio-engineering research in the production of its active ingredients and bioenergy
The complete chloroplast genome sequence of Rubus peltatus Maxim. (Rosaceae)
Rubus peltatus Maxim. (Bull. Acad. Imp. 1871) is a wild species endemic to East and Southeast China. However, genetic resources were unavailable for this species. It holds great potential for domestication or other breeding purposes with the extraordinary large yellow fruits. The complete chloroplast genome sequence of R. peltatus, assembled with Illumina Hiseq X Ten platform sequencing data, was reported. The chloroplast genome was 155,582 bp in length. The large single-copy (LSC) and small single-copy (SSC) of 85,329 bp and 18,779 bp were separated by two inverted repeats (IRs) of 25,737 bp. The chloroplast genome of R. peltatus contains 130 genes, including eight transfer RNA genes, 36 ribosomal RNA genes, and 86 protein-coding genes. Phylogenetic analysis supports R. peltatus has a close relationship with the R. cochinchinensis and R. takesimensis
Development of piezoresistive cement-based sensor using recycled waste glass cullets coated with carbon nanotubes
Different from widely exploring the application of waste glass to replace natural aggregate or cement powder, this study firstly utilized waste glass cullets coated with carbon nanotubes (CNTs) as conductive fillers to develop
novel self-sensing cement-based sensors. The coating efficiency of CNTs and self-sensing properties were also investigated in terms of workability, water absorption, mechanical properties, electrical resistivity and microstructure. The results show that CNTs are attached to the surfaces of waste glass particles, especially the smallsize waste glass particles with high roughness. Workability decreased significantly with the increased waste glass.
Cementitious mortar with sand replaced by CNTs-coated waste glass exhibited the highest flowability when the replacement ratio was 25%. Moreover, the water impermeability continuously increased with the content of waste glass. The compressive strength was higher than that of the control mortar, which reached the highest with 50% waste glass content. Additionally, an excellent piezoresistivity was achieved for cement-based sensors with CNTs-coated waste glass particles for the self-monitoring of stress magnitude and failure. The CNTs are uniformly distributed well in the cement matrix by attaching the surfaces of waste glass particles, thus the conductive passages are formed in cement-based sensors for structural health monitoring
Biochar-cement concrete toward decarbonisation and sustainability for construction: Characteristic, performance and perspective
Biochar has been increasingly used in the production of cementitious materials due to its low cost, low-carbon emission, and environmental benefits. This study provides a comprehensive review on the effect of biochar on the performance of cementitious composites, focusing on mechanical properties, durability properties, and carbon-sequestration capacity. It has been observed that the use of biochar can improve the mechanical strength, thermal, and electromagnetic performance of hardened biochar-cement composites. The optimum cement replacement with biochar is 1–2 wt% (by weight) for enhancing the compressive and flexural strength. Additionally, the addition of biochar can improve the resistance to sulphate attacks, chloride-induced corrosion, shrinkage, and permeability of biochar-cement composites. Biochar also has the potential to reduce the permeability of concrete, and no significant differences were observed in permeability reduction for biochar processed at different pyrolysis temperatures. The positive effect of biochar (up to 5 wt%) on durability improvement is attributed to enhanced hydration and physical filling, resulting in a denser microstructure that prevents the penetration of ions and water. This study also discusses the impact of biochar on carbon sequestration capacity, demonstrating its ability to enhance the carbon-sequestration capacity of biochar-based concrete. In conclusion, while the mechanical properties of concrete with biochar have been extensively investigated, future research is needed to explore the long-term durability properties under different environmental conditions. Moreover, there is a growing demand for low-carbon concrete that utilizes carbon-negative materials to enhance performance and resilience.This accepted article is published as Lin, X., Li, W., Guo, Y., Dong, W., Cstel, A., Wang, K., Biochar-cement concrete toward decarbonisation and sustainability for construction: Characteristic, performance and perspective. Journal of Cleaner Production. 419(Sept 2023);138219.;https://doi.org/10.1016/j.jclepro.2023.138219. Posted with permission
Development of self-sensing ultra-high-performance concrete using hybrid carbon black and carbon nanofibers
The self-sensing ultra-high-performance concrete (UHPC) was developed in this study by incorporating nano carbon black (CB) and carbon nanofiber (CNF) as additives into the UHPC matrix. Single CB and hybrid CB/CNF filled UHPCs were compared in terms of strength, microstructures, percolation threshold, conductivity, and piezoresistive sensing performance. The results indicate that hybrid CB/CNF filled UHPC consistently exhibits superior compressive strength compared to the counterpart with single CB. The percolation threshold begins at approximately 0.5 % CB content, regardless of the inclusion of CNF. The CNF serves to link the surrounding conductive passages contributed by CB nanoparticles, demonstrating the positive effect of hybrid nanofillers with multiple dimensions. AC impedance spectroscopy (ACIS) and equivalent circuit modelling were performed to understand the synergetic effect of CB/CNF on the electrical network in UHPC matrix and to compare the conductive characteristics between single CB and hybrid CB/CNF filled self-sensing UHPC. The insights gained from this analysis contribute to comprehending the conductive behaviours and sensing mechanisms at the microstructural level, providing new insight into the material design strategy to enhance the electrical and sensing performances of UHPC-based cementitious sensors. Regarding piezoresistive performance, the stability of sensing performance in response to dynamic cyclic load improves with an increasing content of conductive fillers; the hybrid fillers of CB/CNF enhance the stability of piezoresistive sensing performance of self-sensing UHPC with less signal noise under monotonic compressive loading. The outcomes can integrate the piezoresistive self-sensing capacity with UHPC to promote the application of cement-based sensors in civil infrastructure, offerring potential benefits for structural health monitoring and maintenance.This article is published as Li, Wengui, Yipu Guo, Xuanrui Zhang, Wenkui Dong, Xiaohu Li, Tao Yu, and Kejin Wang. "Development of self-sensing ultra-high-performance concrete using hybrid carbon black and carbon nanofibers." Cement and Concrete Composites 148 (2024): 105466. doi:10.1016/j.cemconcomp.2024.105466. © 2024 The Author(s).This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Self-sensing cement-based sensors with superhydrophobic and self-cleaning capacities after silane-based surficial treatments
A novel cement-based sensors was developed with integrated self-sensing superhydrophobicity, and self-cleaning functions in this paper. The synthesis was carried out by penetrating precast graphene nanoplate/cement-based sensors with silane/isopropanol solutions. The silane-treated cement-based sensors showed satisfactory stress/strain sensing performance with an average gauge factor of 141.8, and exhibited excellent hydrophobic behaviour with the highest water contact angle of 163° on the intact surface. The contact angle decreased to 148° and 142°, for the surface with scratches and for the inner part of sensors, respectively. The reduction was due to the spalling and less amount of silane particles within the scratches and the harder entry of silane to the inner part of sensor. The self-cleaning properties of silane-treated cement-based sensor were evaluated by the visual observation of removing efficiency of hydrophilic carbon black dust and lipophilic sauces after water rinsing. It was found that the silane-treated cement-based sensor showed excellent self-cleaning performance using hydrophilic carbon dust. Despite the removing efficiency decreased for the lipophilic sauces, the silane-treated cement-based sensors maintained much less stain than that of untreated ones on the surface. The related results will promote the synthesis and practical applications of multifunctional cement-based sensors for the application of intrisic structural health monitoring.This article is published as Guo, Yipu, Wengui Li, Wenkui Dong, Kejin Wang, Xuzhen He, Kirk Vessalas, and Daichao Sheng. "Self-sensing cement-based sensors with superhydrophobic and self-cleaning capacities after silane-based surficial treatments." Case Studies in Construction Materials 17 (2022): e01311. doi:10.1016/j.cscm.2022.e01311. © 2022 The Authors. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
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