The dynamic cell–cell communication is essential for tissue homeostasis in normal physiological circumstances and contributes to a diversified tumor microenvironment. Although exosomes are ...extracellular vesicles that actively participate in cell–cell interaction by shutting cellular components, impacts of tumor exosomes in the context of cancer stemness remain elusive. Here, we expand colorectal cancer stem cells (CRCSCs) as cancer spheroids and demonstrate that the β‐catenin/Tcf‐4‐activated RAB27B expression is required for the secretion of CRCSC exosomes. In an exosomal RNA sequencing analysis, a switch of exosomal RNA species from retrotransposons to microRNAs (miRNAs) is identified upon expanding CRCSCs. miRNA‐146a‐5p (miR‐146a) is the major miRNA in CRCSC exosomes and exosomal miR‐146a promotes stem‐like properties and tumorigenicity by targeting Numb in recipient CRC cells. Among 53 CRC patients, those with abundant exosomal miR‐146a expression in serum exhibits higher miR‐146aHigh/NumbLow CRCSC traits, an increased number of tumor‐filtrating CD66(+) neutrophils and a decreased number of tumor‐infiltrating CD8(+) T cells. Our study elucidates a unique mechanism of tumor exosome‐mediated stemness expansion.
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The tumor microenvironment (TME) is composed of heterogeneous tumor cells and host cells interacting with each other to promote disease progression. However, diagnostic and prognostic biomarkers to monitor the cancer stem cells (CSCs)‐host interplay are lacking. Here, the authors explore the role of tumor exosomes in cancer stemness and demonstrate that RAB27B‐assisted secretion of miRNA‐dominant exosomes is one critical feature of CSCs. Importantly, they show that colorectal cancer stem cells release miR‐146a‐loaded oncogenic exosomes for reprogramming non‐CSC cells and demonstrate the clinical relevance of exosomal miR‐146a in predicting the TME of CRC patients.
We apply the double‐beamforming tomography to a monthlong temporary dense seismic array to obtain high‐resolution images of the San Jacinto Fault's damage zone. We obtain Rayleigh waves between 0.3‐ ...and 0.8‐s periods via vertical‐vertical noise cross correlation, apply double beamforming to obtain phase velocities, and apply a piecewise 1‐D least squares inversion to obtain shear velocities in the top 300 m. We observe a ~200‐m‐wide low‐velocity zone that narrows with depth, which we interpret as the main damage zone in addition to two other ~100‐m‐wide subsidiary zones corresponding to secondary damaged structures, agreeing with the distribution of fault zone trapped waves produced by local earthquakes. The primary damage zone asymmetry indicates that materials on the northeast side of the fault are stiffer at seismogenic depth and suggests that large San Jacinto earthquakes tend to nucleate to the southeast and propagate to the northwest.
Key Points
We present shear wave velocities in the upper 300 m at the San Jacinto Fault, Clark segment
The damage zone is asymmetric, with more damage to the northeast of the fault trace
The damage zone geometry agrees with fault zone trapped waves generated by local earthquakes
Virtual Reality (VR) has been rapidly recognized and implemented in construction engineering education and training (CEET) in recent years due to its benefits of providing an engaging and immersive ...environment. The objective of this review is to critically collect and analyze the VR applications in CEET, aiming at all VR-related journal papers published from 1997 to 2017. The review follows a three-stage analysis on VR technologies, applications and future directions through a systematic analysis. It is found that the VR technologies adopted for CEET evolve over time, from desktop-based VR, immersive VR, 3D game-based VR, to Building Information Modelling (BIM)-enabled VR. A sibling technology, Augmented Reality (AR), for CEET adoptions has also emerged in recent years. These technologies have been applied in architecture and design visualization, construction health and safety training, equipment and operational task training, as well as structural analysis. Future research directions, including the integration of VR with emerging education paradigms and visualization technologies, have also been provided. The findings are useful for both researchers and educators to usefully integrate VR in their education and training programs to improve the training performance.
Circular RNA (circRNA) is a class of noncoding RNA whose functions remain mostly unknown. Recent studies indicate circRNA may be involved in disease pathogenesis, but direct evidence is scarce. Here, ...we characterize the functional role of a novel circRNA, circCCDC66, in colorectal cancer. RNA-Seq data from matched normal and tumor colon tissue samples identified numerous circRNAs specifically elevated in cancer cells, several of which were verified by quantitative RT-PCR. CircCCDC66 expression was elevated in polyps and colon cancer and was associated with poor prognosis. Gain-of-function and loss-of-function studies in colorectal cancer cell lines demonstrated that circCCDC66 controlled multiple pathological processes, including cell proliferation, migration, invasion, and anchorage-independent growth. In-depth characterization revealed that circCCDC66 exerts its function via regulation of a subset of oncogenes, and knockdown of circCCDC66 inhibited tumor growth and cancer invasion in xenograft and orthotopic mouse models, respectively. Taken together, these findings highlight a novel oncogenic function of circRNA in cancer progression and metastasis.
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One of the biggest challenges for EFL (English as Foreign Language) students to learn English is the lack of practicing environments. Although language researchers have attempted to conduct flipped ...classrooms to increase the practicing time in class, EFL students generally have difficulties interacting with peers and teachers in English in class. The advancement of Artificial Intelligence (AI) provides an opportunity to address this problem. With AI technologies, computer systems, in particular in the form of AI chatbots, are able to identify the meanings of users' statements and make responses accordingly. In the research design, AI-based chatbots were employed in the in-class and out-of-class activities for facilitating the students' speaking performance and interactions during the learning process in a university flipped English speaking classroom. The experimental results show that the mind map-guided AI chatbot approach (MM-AI) promoted the students' English speaking performances more than did the conventional AI chatbot approach (C-AI). Moreover, the MM-AI also promoted the students' learning performance and organized the interaction between the robots and humans more than the C-AI did. The findings could be a valuable reference for language educators and researchers who intend to conduct AI-supported flipped classrooms in language learning.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A series of new amino (NH)-type hydrogen-bonding (H-bonding) compounds comprising 2-(2′-aminophenyl)benzothiazole and its extensive derivatives were designed and synthesized. Unlike in the hydroxyl ...(OH)-type H-bonding systems, one of the amino hydrogens can be replaced with electron-donating/withdrawing groups. This, together with a versatile capability for modifying the parent moiety, makes feasible the comprehensive spectroscopy and dynamics studies of amino-type excited-state intramolecular proton transfer (ESIPT), which was previously inaccessible in the hydroxyl-type ESIPT systems. Empirical correlations were observed among the hydrogen-bonding strength (the N–H bond distances and proton acidity), ESIPT kinetics, and thermodynamics, demonstrating a trend that the stronger N–H···N hydrogen bond leads to a faster ESIPT, as experimentally observed, and a more exergonic reaction thermodynamics. Accordingly, ESIPT reaction can be harnessed for the first time from a highly endergonic type (i.e., prohibition) toward equilibrium with a measurable ESIPT rate and then to the highly exergonic, ultrafast ESIPT reaction within the same series of amino-type intramolecular H-bond system.
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•Co-pyrolysis or co-gasification can effectively convert waste into hydrogen gas.•Gas yields can be improved while reducing tar using catalysts and pretreatment.•Co-processing can ...solve the conversion issues of feedstock alone.•Plastics and biomass can be utilized as renewable resources using co-processing.
Sustainable energy sources are a solution to the increase in energy demand as a result of population growth. Pyrolysis and gasification are thermochemical processing techniques that can be used to convert biomass and plastic waste into energy. Co-processing (co-pyrolysis or co-gasification) has been identified as one of the major thermal techniques, which provides a significant framework for converting waste into fuels with higher hydrogen concentrations. The production of hydrogen from biomass and plastic waste using these techniques is being explored for its high conversion efficiencies and low processing costs. Catalysts and acid pre-treatment are used to improve gas production while reducing tar content. The best gasification agent is steam with oxygen. A thorough review of the literature revealed only a few studies on the co-pyrolysis and co-gasification of plastics and biomass for syngas production, particularly hydrogen-rich syngas. Therefore, this review focuses on H2 production from plastics and biomass by using co-pyrolysis and co-gasification. This critical discussion is aimed at improving the understanding of the subject, its relevant aspects, and its significant perspectives. In addition, it also deals with the mechanism and relevance of these techniques, along with their techno-econome evaluation. Compared to pyrolysis or gasification of plastic waste or biomass alone, co-processing often has significant impacts with improved final products. The reaction of molecules during co-processing and the transition of hydrogen from plastics to biomass derivatives account for these improved properties. H2 concentrations increase with increasing temperature in the presence of different catalysts. Even at lower temperatures, CO2 adsorption increases H2 production and enhances syngas quality while reducing the tar content. Finally, to provide sustainable energy for future generations and enasure an efficient system for sustainable waste management, further research is required to increase efficiency and hydrogen yields.
Seismic structure beneath the contiguous U.S. was imaged with multimode receiver function stacking and inversion of Rayleigh wave dispersion and ellipticity measurements. Crust thickness and ...elevation are weakly correlated across the contiguous U.S., but the correlation is ~3–4 times greater for separate areas east and west of the Rocky Mountain Front (RMF). Greater lower crustal shear velocities east of the RMF, particularly in low‐elevation areas with thick crust, are consistent with deep crustal density as the primary cause of the contrasting crust thickness versus elevation trends. Separate eastern and western trends are best fit by Airy isostasy models that assume lower crust to uppermost mantle density increases of 0.18 g/cm3 and 0.40 g/cm3, respectively. The former value is near the minimum that is plausible for felsic lower crust. Location of the transition at the RMF suggests that Laramide to post‐Laramide processes reduced western U.S. lower crustal density.
Key Points
Distinct crustal isostasy trends identified east and west of the Rocky Mountain Front
East of the RMF mean lower crust to mantle density contrast is about half that in the west
Laramide to post‐Laramide processes likely reduced the density of western U.S. lower crust
Beneš networks are well-known rearrangeable nonblocking (RNB) multistage networks. The so-called conventional Benes networks are based on 2×2 switches. In this paper, Beneš network is a general term ...used to refer to an N × N n -nary Benes network. Such networks, denoted by B( n, t ), where N = n t and t ≥ 2, are based on regular n × n switches, and are RNB as well. A Beneš network is constructed recursively from a 3-stage Clos network. For an N × N RNB Clos network C( n, m, r ), where N = nr and m ≥ n , the maximum allowable number of non-contact faults in each single shell for realizing any permutation has been investigated in an earlier study, where shell k in a network consists of both the k th and the k th-to-last node stages. That study showed that, for a given integer N , an RNB C( n, n, r ) network with larger n × n switches leads to tolerance of more non-contact faults in shell 1. In this paper, for an N × N B( n, t ) network, we study the maximum allowable number, say f k , of non-contact faults for any permutation not only in each single shell k , but also in all shells simultaneously under the fault condition that at most f k non-contact faults are arbitrarily located in the switches in each shell k . We call the former the fault tolerance capability in a single shell, and the latter the fault tolerance capability of the network. We show that a larger switch size, i.e., n × n , in an N × N B( n, t ) network leads to a higher fault tolerance capability of the network and a higher fault tolerance capability in each non-middle shell. An N × N Beneš network B( n, t ) considers only the value of N which is a power of n . To consider a flexible N with N = n s · q , where s ≥ 2, 1 < q < n and q | n , which means that n is divisible by q , we propose in this paper an N × N RNB Beneš-type network using regular n × n switches, which is called an extended Beneš and denoted by B( n, s, q ). Both Beneš and extended Beneš networks are based on regular switches, and they have better scalabilities than a Clos network. We define a network's fault tolerance rate as the ratio of the fault tolerance capability to the total crosspoints in the network. For given integers N and n , we derive that the fault tolerance capability and fault tolerance rate of an N × N Beneš (or extended Beneš) network are higher than or equal to those of an N × N RNB C( n, n, r ) network, and the former outperforms the latter in most cases.
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