A series of TiO2/biochar composite catalysts were prepared by the hydrolysis method for the degradation of methyl orange, where biochar was obtained from the pyrolysis of waste walnut shells. The ...catalysts were examined by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), photoluminescence spectroscopy (PL) and X-ray photoelectron spectroscopy (XPS), elemental analysis and ultra violet-visible diffuse reflectance spectroscopy (UV–vis DRS). The photocatalytic activity results showed that the catalysts noted as CT0.1/1, CT0.2/2 and CT 0.5/1 exhibited higher catalytic activity than that of pure TiO2. Besides, catalyst CT0.2/1 exhibited the highest catalytic activity (the decolorization efficiency of 96.88% and the mineralization efficiency of 83.23% were obtained), attributed to the synergistic effect of biochar and TiO2, while CT1/1 possessed the lowest activity due to the shelter of light by the excess biochar. After 5 repeated use, the catalyst CT0.2/1 still exhibited rather high activity toward the degradation of MO, where the decolorization efficiency and mineralization efficiency of MO achieved 92.45% and 76.56%, and the loss of activity was negligible.
•Walnut shell biochar was firstly served as low-cost support for TiO2.•Appropriate amount of biochar can promote the activity of TiO2.•Compared with TiO2, the decolorization and mineralization efficiency of CT0.2/1 increased by 20.84% and 51.00%, respectively.•CT0.2/1 exhibited high stability during repeated use.
One set of biochar-coupled Ag and TiO2 composites were successfully fabricated by mixing, calcination, and photodeposition method to remove methyl orange (MO). It was found that all catalysts ...modified with Ag showed better photocatalytic degradation performance (the highest decolorization efficiency and mineralization efficiency were 97.48% and 85.38%, respectively) than single TiO2 because of the synergy of Ag, TiO2 and biochar. Characterization results indicated that Ag as well as TiO2 acted as electron donor and biochar acted as electron acceptor, which could effectively promote the separation of photogenerated electron hole pairs. In addition, the catalyst exhibited high stability up to 5 cycles and the loss of activity was negligible. And the catalytic degradation process was consistent with the pseudo-first-order kinetic (PFOK) model with the degradation rate constant of 6.29 × 10−2 min−1.
•Ag/TiO2/biochar composite catalyst were successfully synthesized for dye removal.•The synergistic effect of biochar, TiO2 and Ag can promote the activity of TiO2.•The removal efficiency can be significantly increased compared to pure TiO2.•Ag/TiO2/biochar composite catalyst exhibited high stability during repeated use.
•Developed a robust cooperative control strategy (RCC) strategy to improve the performance of CAV platoon against uncertain vehicle dynamics•Designed an efficient and globally convergent solution ...algorithm for the minimax problem.•Analyzed the conditions for robust stability of the RCC strategy
In real-world driving environments, a platoon of connected and autonomous vehicles (CAVs) will be subject to many disturbances (e.g., aerodynamic drag, dynamic road gradients) that can prevent them from achieving desired control accurately. These disturbances can cause uncertainties in the vehicle dynamics, reducing platoon safety and mobility. To address this problem, this study proposes a robust cooperative control (RCC) strategy, developed as a minimax problem, to ensure the safe and efficient maneuvering of a CAV platoon in the worst-case situation due to uncertainties in the vehicle dynamics. The maximization subproblem of the minimax problem determines the inputs of the uncertainties to maximize the cost function (i.e., the platoon performance indicator), while the minimization subproblem seeks to optimize the control decisions for all following vehicles in the platoon to minimize the cost function using inputs of the uncertainties from the maximization subproblem. A novel partition-based method of feasible direction is proposed to solve the minimax problem. It is globally convergent and computationally efficient, enabling the RCC strategy to be deployed in real time. The conditions for robust stability of the CAV platoon are also analyzed. Results from numerical studies show that compared to a control strategy that ignores uncertainties in vehicle dynamics, the RCC strategy can substantially improve the platoon performance under disturbances. Hence, it can be used to enable the safe and efficient maneuvering of CAV platoons in a real-world driving environment.
•The floor field CA model is extended to incorporate the pedestrian group behaviors based on the leader-follower behavioral rule.•The proposed model is calibrated with a few field experiments of ...crowd evacuation conducted in a university building.•The evacuation time significantly increases with the presence of pedestrian groups in the crowd.•The effects of several group behaviors in an evacuation situation are investigated through parameter sensitivity analyses.
In the study of pedestrian movements, a consideration of group behaviors is important because of their potential impacts on pedestrian flow dynamics. In this paper, we investigate the group behaviors during emergency evacuation, which is a critical case for emergency crowd management but has not been fully explored and understood. It has been well recognized that in evacuation situations, some people within a crowd, especially those who are with families and friends, often move in small groups and act in particular patterns distinct from individuals. As a result, the crowd is a mixture of individuals and groups rather than a pure collection of individuals. To capture and evaluate the influence of group behaviors on crowd evacuation, we propose an extended floor field cellular automaton (CA) model that takes into account such phenomena. Our model is formulated by leveraging the leader-follower behavior rule that is evident in pedestrian group behaviors. To calibrate and validate the proposed model, a few field experiments of crowd evacuation were conducted in a university building. Through a representative case study, it is demonstrated that the proposed extended floor field CA model can replicate the well-known phenomena in crowd evacuation such as collective arch-like clogging at the exit as well as other commonly observed group behaviors in evacuation. Moreover, it is found that the total crowd evacuation time significantly increases with the presence of pedestrian groups in the crowd. The results also show that such negative effects of group behaviors in crowd evacuation intensify when the density of the crowd is higher. Subsequently, sensitivity analyses are performed to further explore how pedestrian group behaviors are influenced by model parameters that reflect the pedestrian flow dynamics in evacuation scenarios. With its capability of realistically replicating the field pedestrian evacuation, the proposed model can serve as a valuable tool for predicting crowd evacuation time and designing guidelines for pedestrian evacuation in emergency situations, in particular when group behaviors are salient.
Multiple cotton genomes (diploid and tetraploid) have been assembled. However, genomic variations between cultivars of allotetraploid upland cotton (Gossypium hirsutum L.), the most widely planted ...cotton species in the world, remain unexplored. Here, we use single-molecule long read and Hi-C sequencing technologies to assemble genomes of the two upland cotton cultivars TM-1 and zhongmiansuo24 (ZM24). Comparisons among TM-1 and ZM24 assemblies and the genomes of the diploid ancestors reveal a large amount of genetic variations. Among them, the top three longest structural variations are located on chromosome A08 of the tetraploid upland cotton, which account for ~30% total length of this chromosome. Haplotype analyses of the mapping population derived from these two cultivars and the germplasm panel show suppressed recombination rates in this region. This study provides additional genomic resources for the community, and the identified genetic variations, especially the reduced meiotic recombination on chromosome A08, will help future breeding.
Recent studies have suggested a crucial role of mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) in ovarian cancer treatment. We, therefore, set out to explore the mechanism through ...which MSC-derived EVs delivered microRNA-424 (miR-424) to influence the development of ovarian cancer.
Bioinformatics analyses were first performed to screen ovarian cancer-related differentially expressed genes and to predict regulatory miRNAs. Then, dual-luciferase reporter gene assay was carried out to verify the relationship between miR-424 and MYB. Subsequently, the characterized MSCs and isolated EVs were co-cultured with ovarian cancer cells, followed by determination of the expression patterns of miR-424, MYB, vascular endothelial growth factor (VEGF), and VEGF receptor (VEGFR), respectively. In addition, the effects of EVs-delivered miR-424 on the proliferation, migration, invasion and tube formation of ovarian cancer cells were assessed using gain- and loss-of-function approaches. Lastly, tumor xenograft was induced in nude mice to illustrate the influence of EVs-loaded miR-424 on ovarian cancer in vivo.
Our data exhibited that MYB was highly-expressed and miR-424 was poorly-expressed in ovarian cancer. More importantly, MYB was identified as a target gene of miR-424. Additionally, the transfer of miR-424 by MSC-derived EVs was found to repress the proliferation, migration, and invasion of ovarian cancer cells, with a reduction in the expressions of VEGF and VEGFR. Furthermore, MSC-derived EVs over-expressing miR-424 could inhibit the proliferation, migration, and tube formation of human umbilical vein endothelial cells, and also suppressed tumorigenesis and angiogenesis of ovarian tumors in vivo.
Collectively, our findings indicate that MSC-derived EVs transfer miR-424 to down-regulate MYB, which ultimately led to the inhibition of the tumorigenesis and angiogenesis of ovarian cancer. Hence, this study offers a potential prognostic marker and a therapeutic target for ovarian cancer.
Background
Gastrointestinal (GI) cancers were responsible for 26.3% of cancer cases and 35.4% of deaths worldwide in 2018. This study aimed to analyze the global incidence, mortality, prevalence, and ...contributing risk factors of the 6 major GI cancer entities esophageal cancer (EC), gastric cancer (GC), liver cancer (LC), pancreatic cancer (PC), colon cancer, and rectal cancer.
Methods
Using the Global Cancer Observatory and the Global Health Observatory databases, we reviewed the current GI cancer incidence, prevalence, and mortality, analyzed the association of GI cancer prevalence with national human development indices (HDIs), identified the contributing risk factors, and estimated developing age‐ and sex‐specific trends in incidence and mortality.
Results
In 2020, the trend in age‐standardized rate of incidence of GI cancers closely mirrored that of mortality, with the highest rates of LC, EC, and GC in Asia and of colorectal cancer (CRC) and PC mainly in Europe. Incidence and mortality were positively, but the mortality‐to‐incidence ratio (MIR) was inversely correlated with the national HDI levels. High MIRs in developing countries likely reflected the lack of preventive strategies and effective treatments. GI cancer prevalence was highest in Europe and was also positively correlated with HDIs and lifestyle‐associated risk factors, such as alcohol consumption, smoking, obesity, insufficient physical activity, and high blood cholesterol level, but negatively correlated with hypertension and diabetes. Incidences of EC were consistently and those of GC mostly decreasing, whereas incidences of CRC were increasing in most countries/regions, especially in the younger populations. Incidences of LC and PC were also increasing in all age‐gender populations except for younger males. Mortalities were decreasing for EC, GC, and CRC in most countries/regions, and age‐specific trends were observed in PC and LC with a decrease in the younger but an increase in the older population.
Conclusions
On the global scale, higher GI cancer burden was accompanied, for the most part, by factors associated with the so‐called Western lifestyle reflected by high and very high national HDI levels. In countries/regions with very high HDI levels, patients survived longer, and increasing GI cancer cases were observed with increasing national HDI levels. Optimizing GI cancer prevention and improving therapies, especially for patients with comorbid metabolic diseases, are thus urgently recommended.
Prevalence of gastrointestinal cancers was positively correlated with national human development index levels, but negatively with hypertension and diabetes rates. Age‐specific trends were observed in stomach cancer and esophagus cancer for incidence and in liver cancer and pancreatic cancer for mortality, as well as sex‐specific trends for stomach cancer and pancreatic cancer in the elder.These findings suggest that future research has to focus on the specific etiology of gastrointestinal cancers behind these epidemiologic transitions and improve therapeutic strategies for patients with comorbid metabolic diseases.
Extracellular vesicles (EVs) secreted from tumor-associated macrophages (TAMs) are known to generate an immune-suppressive environment conducive to the development of ovarian cancer (OC). We tried to ...elucidate the role of TAM-derived exosomal microRNA (miR)-29a-3p in OC. miR-29a-3p, forkhead box protein O3 (FOXO3), and programmed death ligand-1 (PD-L1) expression was determined and their interactions evaluated. EVs were isolated, followed by determination of the uptake of EVs by OC cells, after which the proliferation and immune escape facilities of the OC cells were determined. OC xenograft models were constructed with EVs in correspondence with in vivo experiments. Overexpressed miR-29a-3p was detected in OC, and miR-29a-3p promoted OC cell proliferation and immune escape. EVs derived from TAMs enhanced the proliferation of OC cells. miR-29a-3p was enriched in TAM-EVs, and TAM-EVs delivered miR-29a-3p into OC cells. Downregulated FOXO3 was identified in OC, whereas miR-29a-3p targeted FOXO3 to suppress glycogen synthase kinase 3β (GSK3β) activity via the serine/threonine protein kinase (AKT)/GSK3β pathway. Inhibition of TAM-derived exosomal miR-29a-3p decreased PD-L1 to inhibit OC progression through the FOXO3-AKT/GSK3β pathway in vitro and in vivo. Taken together, the current studies highlight the FOXO3-AKT/GSK3β pathway and the mechanism by which TAM-derived exosomal miR-29a-3p enhances the expression of PD-L1 to facilitate OC cell proliferation and immune escape.
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We found overexpressed miR-29a-3p in OC and found that miR-29a-3p shuttled by TAM-EVs promoted OC cell proliferation and immune escape. IN addition, miR-29a-3p targeted FOXO3 to suppress GSK3β activity through the AKT/GSK3β pathway. Altogether, our study uncovered a new FOXO3-AKT/GSK3β pathway by which TAM-derived exosomal miR-29a-3p enhanced PD-L1 expression to facilitate OC progression.
Lead contamination is now widespread, and exposure to lead may cause adverse effects on human beings. In this study, a photoelectrochemical sensor based on flower-like ZnO nanostructures was ...developed for Pb2+ detection, using a Pb2+-dependent DNAzyme as the recognition unit and a double-strand DNA intercalator, Ru(bpy)2(dppz)2+ (bpy=2,2'-bipyridine, dppz=dipyrido3,2-a:2',3'-c phenazine) as the photoelectrochemical signal reporter. The ZnO nanoflower was fabricated on an indium tin oxide (ITO) electrode by the convenient hydrothermal decomposition method. The morphology and photoelectrochemical property of the ZnO nanoflowers were characterized by SEM, XRD and photocurrent measurements. DNAzyme-substrate duplex was assembled on an ITO/ZnO electrode through electrostatic adsorption. In the presence of Pb2+, RNA-cleavage activity of the DNAzyme was activated and its substrate strand was cleaved, resulting in the release of Ru(bpy)2(dppz)2+ from the DNA film and the concomitant photocurrent decrease. The detection principle was verified by fluorescence measurements. Under the optimized conditions, a linear relationship between photocurrent and Pb2+ concentration was obtained over the range of 0.5–20nM, with a detection limit of 0.1nM. Interference from other common metal ions was found negligible. Applicability of the sensor was demonstrated by analyzing lead level in human serum and Pb2+ spiked water samples. This facile and economical sensor system showed high sensitivity and selectivity, thus can be potentially applied for on-site monitoring of lead contaminant.
•A novel photoelectrochemical DNAzyme sensor was developed for Pb2+ detection.•Flower-like ZnO nanostructure was employed as the electrode material.•The detection limit of the sensor was 0.1nM.•The sensor allows selective and sensitive detection of Pb2+ in human serum and water samples.
WUSCHEL-related homeobox (WOX) family members play significant roles in plant growth and development, such as in embryo patterning, stem-cell maintenance, and lateral organ formation. The recently ...published cotton genome sequences allow us to perform comprehensive genome-wide analysis and characterization of WOX genes in cotton.
In this study, we identified 21, 20, and 38 WOX genes in Gossypium arboreum (2n = 26, A
), G. raimondii (2n = 26, D
), and G. hirsutum (2n = 4x = 52, (AD)
), respectively. Sequence logos showed that homeobox domains were significantly conserved among the WOX genes in cotton, Arabidopsis, and rice. A total of 168 genes from three typical monocots and six dicots were naturally divided into three clades, which were further classified into nine sub-clades. A good collinearity was observed in the synteny analysis of the orthologs from At and Dt (t represents tetraploid) sub-genomes. Whole genome duplication (WGD) and segmental duplication within At and Dt sub-genomes played significant roles in the expansion of WOX genes, and segmental duplication mainly generated the WUS clade. Copia and Gypsy were the two major types of transposable elements distributed upstream or downstream of WOX genes. Furthermore, through comparison, we found that the exon/intron pattern was highly conserved between Arabidopsis and cotton, and the homeobox domain loci were also conserved between them. In addition, the expression pattern in different tissues indicated that the duplicated genes in cotton might have acquired new functions as a result of sub-functionalization or neo-functionalization. The expression pattern of WOX genes under different stress treatments showed that the different genes were induced by different stresses.
In present work, WOX genes, classified into three clades, were identified in the upland cotton genome. Whole genome and segmental duplication were determined to be the two major impetuses for the expansion of gene numbers during the evolution. Moreover, the expression patterns suggested that the duplicated genes might have experienced a functional divergence. Together, these results shed light on the evolution of the WOX gene family, and would be helpful in future research.
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