The differences in archaeal diversity and community composition in the sediments and waters of the Qinhuangdao coastal aquaculture zone were investigated. Furthermore, the associations between ...dominant archaeal taxa with geographic and environmental variables were evaluated. High-throughput sequencing of archaeal 16S rRNA genes yielded a total of 176,211 quality-filtered reads and 1,178 operational taxonomic units (OTUs) overall. The most abundant phylum and class among all communities were Thaumarchaeota and Nitrososphaeria, respectively. Beta diversity analysis indicated that community composition was divided into two groups according to the habitat type (i.e., sediments or waters). Only 9.8% OTUs were shared by communities from the two habitats, while 73.9% and 16.3% of the OTUs were unique to sediment or water communities, respectively. Furthermore, the relative abundances of the dominant OTUs differed with habitat type. Investigations of relationships between dominant OTUs and environmental variables indicated that some dominant OTUs were more sensitive to variation in environmental factors, which could be due to individual taxonomic differences in lifestyles and biological processes. Overall, the investigation of archaeal community variation within the Qinhuangdao coastal aquaculture zone provides an important baseline understanding of the microbial ecology in this important ecosystem.
Fluorescent nanoprobes show similar fluorescence properties to traditional organic dyes, but the addition of nanotechnology accurately controls the size, shape, chemical composition, and surface ...chemistry of the nanoprobes with unique characteristics and properties, such as bright luminescence, high photostability, and strong biocompatibility. For example, modifying aptamers or antibodies on a fluorescent nanoprobe provides high selectivity and specificity for different objects to be tested. Fluorescence intensity, life, and other parameters of targets can be changed by different sensing mechanisms based on the unique structural and optical characteristics of fluorescent nanoprobes. What's more, the detection of fluorescent nanoprobes is cost-saving, simple, and offers great advantages in rapid food detection. Sensing mechanisms of fluorescent nanoprobes were introduced in this paper, focusing on the application progress in pesticide residues, veterinary drug residues, heavy metals, microbes, mycotoxins, and other substances in food safety detection in recent years. A brief outlook for future development was provided as well.
Background: Tumor metastasis of colorectal cancer (CRC) is the main cause of death in most patients and the major difficulty in comprehensive CRC treatment. Circular RNAs (circRNAs) affect many ...biological functions in solid tumors. However, their mechanisms in CRC metastasis remain unclear. Methods: RNA sequencing (RNA-seq) and quantitative real-time PCR were performed to screen differentially expressed circRNAs between CRC tissues and adjacent normal tissues. CCK-8, cell migration and wound healing assays were performed to determine the functions of circRHOBTB3 in cell proliferation and metastasis. RNA pulldown and RNA immunoprecipitation assays were performed to verify the interaction between circRHOBTB3 and the HuR (ELAVL1) protein. Further RNA-seq and rescue experiments were applied to search for the downstream target. We also conducted a mouse xenograft model to elucidate the effect of circRHOBTB3 on cancer metastasis in vivo. Results: We identified circRHOBTB3 which is markedly downregulated in CRC tissues and cell lines. Furthermore, lower circRHOBTB3 levels were significantly associated with advanced clinical stages and greater risk of metastases. Overexpression of circRHOBTB3 suppresses tumor metastasis in CRC cells. Mechanistically, circRHOBTB3 binds to HuR, which is a ubiquitously expressed and functional RNA-binding protein (RBP) in CRC development, and promotes β-Trcp1-mediated ubiquitination of HuR. Normally, HuR binds to the 3'UTR of target mRNAs to facilitate their stabilization, whereas the interaction between circRHOBTB3 and HuR degrades HuR to reduce the expression level of the downstream target PTBP1. Furthermore, overexpressed circRHOBTB3 suppresses lung metastases in vivo, and this effect can be partly reversed by PTBP1 overexpression. In addition, the transcription of circRHOBTB3 can be improved by both FUS and ADARB2 in CRC cells. Conclusions: Our findings indicate that circRHOBTB3 exerts suppressive effects on CRC aggressiveness through the HuR/PTBP1 axis.
The distribution and migration characteristics of weak gel in the core were observed by combining nuclear magnetic resonance (NMR) imaging technology with the core displacement experiment, and the ...oil displacement features of different polymer-weak gel combinations were examined with visualization experiments. Three combination patterns of polymer and weak gel were designed: waterflooding + polymer flooding (pattern 1), waterflooding + polymer flooding + weak gel flooding (pattern 2), and waterflooding + weak gel flooding + polymer flooding (pattern 3). The pressure variations, T2 spectra, nuclear magnetic resonance images, oil displacement efficiencies under the different patterns were analyzed. The results show that the nuclear magnetic images can not only provide the direct information of weak gel distribution and migration characteristics inside the core, but also reflect the distribution characteristics of remaining oil; the T2 spectrum characteristics indicate that both polymer and weak gel have the function of profile control and oil displacement, and the pattern 2 has the best profile control effect; of the three patterns, pattern 2 has the highest oil displacement efficiency of 78.84%, which is 18.33% higher than the displacement efficiency of water flooding in the initial stage.
The air transport system can be considered to be a complex network with airports as vertices and direct flights as edges. Research in this area contributes to the optimisation of the airline network ...and the sustainable development in transportation. This study chose Air China as an example to discover the dynamics of the airline network topologically. Serving as a critical agent of social and economic connections between cities, the airline network structure evolves over time. However, Air China maintains its multicentric and hierarchical structure and forms a mature point-to-point network with codeshare partners. This research also extracts key players at the airport level and investigates the topological structure of highly connected cliques. The results show that the combination of airports in the cliques may be affected by the airline capacity, traffic rights and interline cooperation. Meanwhile, smaller airports appear more often in cliques than hub airports, which can be interpreted and justified with slot limits at mega-airports. The weighted clique percolation method provides new insights to detecting overlapping communities, which can be characterized by geographical constraints. The shared vertices in the combined codeshare network indicate the possible hub shifting in the constantly changing aviation sector.
All stellar-mass black holes have hitherto been identified by X-rays emitted from gas that is accreting onto the black hole from a companion star. These systems are all binaries with a black-hole ...mass that is less than 30 times that of the Sun
. Theory predicts, however, that X-ray-emitting systems form a minority of the total population of star-black-hole binaries
. When the black hole is not accreting gas, it can be found through radial-velocity measurements of the motion of the companion star. Here we report radial-velocity measurements taken over two years of the Galactic B-type star, LB-1. We find that the motion of the B star and an accompanying Hα emission line require the presence of a dark companion with a mass of Formula: see text solar masses, which can only be a black hole. The long orbital period of 78.9 days shows that this is a wide binary system. Gravitational-wave experiments have detected black holes of similar mass, but the formation of such massive ones in a high-metallicity environment would be extremely challenging within current stellar evolution theories.
•Theoretical proof that deconvolution filter LES modeling fixes backflow instabilities.•Numerical benchmarks on idealized and patient-specific geometries corroborating the theory.•New shades on LES ...modeling as a backflow stabilizing method.•Relevance for hemodynamics simulations in the aorta.
In the numerical simulations of incompressible fluids, the occurrence of incoming flows through outlet boundaries where Neumann conditions are prescribed may introduce the numerical instability known as the backflow instability. This backflow instability is related to the nonlinear convective term and is often challenging the numerical simulation of the blood flow in large vessels. In fact, the alternation of systole and diastole induces backflows at the outlets, which are usually Neumann boundaries since the lack of velocity data requires the prescription of traction/pressure conditions. The Reynolds numbers that trigger the backflow instability are generally moderate (in the range of a few hundreds and above).
In this work, we prove that a particular Large Eddy Simulation (LES) model implicitly stabilizes the backflow instability. This LES model uses deconvolution filters and is the basis of the so-called Evolve-Filter-Relax scheme recently introduced by Layton, Rebholz and their collaborators as an effective alternative to Direct Numerical Simulations for the moderate or large Reynolds number flow. With a judicious selection of the parameters of this LES scheme, it is possible to suppress the term that triggers the numerical backflow instability, so to obtain reliable and efficient numerical simulations. This is particularly attractive in computational clinical studies, where many cases need to be studied in a relatively short time.
We provide a rigorous proof of our statement and numerical evidence that corroborates the theory on both idealized and realistic cases. For the latter, we consider a patient-specific aortic aneurysm geometry. Aortic simulations feature Reynolds numbers and flow regimes that particularly benefit from this serendipity (aka ‘two-birds-one-stone’) circumstance, where a LES modeling is stabilizing a numerical artifact.
In this study, the 16S rRNA gene amplicon sequencing technique was used to explore the microbial diversity and differences in the water environment of the Pearl River Estuary in Nansha District with ...various land use types such as the aquaculture area, industrial area, tourist area, agricultural plantation, and residential area. At the same time, the quantity, type, abundance, and distribution of two types of emerging environmental pollutants, antibiotic resistance genes (ARGs) and microplastics (MPs), are explored in the water samples from different functional areas. The results show that the dominant phyla in the five functional regions are Proteobacteria, Actinobacteria and Bacteroidetes, and the dominant genera are Hydrogenophaga, Synechococcus, Limnohabitans and Polynucleobacter. A total of 248 ARG subtypes were detected in the five regions, belonging to nine classes of ARGs (Aminoglycoside, Beta_Lactamase, Chlor, MGEs, MLSB, Multidrug, Sul, Tet, Van). Blue and white were the dominant MP colors in the five regions; 0.5–2 mm was the dominant MP size, and cellulose, rayon, and polyester comprised the highest proportion of the plastic polymers. This study provides the basis for understanding the environmental microbial distribution in estuaries and the prevention of environmental health risks from ARGs and microplastics.
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•Tides can influence the stability of microorganisms, ARGs and microplastics in the Pearl River.•Hydrogenophaga, Synechococcus, and Limnohabitans were the dominant genera in the Pearl River.•A total of 248 ARGs subtypes and 8 MGEs were detected in five different land use types.•Higher levels of microplastics were found in the water column during spring tides.
Two novel indolo3,2-bcarbazole-based metal-free organic dyes (D1 and D2) have been synthesized. The substituted position on the second donor indolo3,2-bcarbazole plays the important roles in tuning ...the photoelectronic properties and controlling the self-aggregation of dyes on photoanode.
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•Two new indolo3,2-bcarbazole-based metal-free organic dyes were synthesized.•The best power conversion efficiency (PCE) of 6.34% is obtained by the dye D2.•The co-sensitization of D1 and D2 further improves the PCE up to 7.03%.
Two new indolo3,2-bcarbazole-based metal-free organic dyes (D1 and D2) were synthesized by utilizing triphenylamine as the first donor which were connected to the second donor indolo3,2-bcarbazole via 9-position and 8-position, respectively. The dyes were characterized by UV–visible absorption spectra and electrochemical analyses. The both two dyes showed intensive absorption spectra in the wavelength of 300–600 nm and narrow band gap of 2.29 eV for D1 and 2.16 eV for D2. The cyclic voltammetry indicated that the oxidative potentials and reductive potentials of the dyes were well matched with the energy levels of the I−/I3− redox couple and TiO2 conduction band, respectively. The substituted positions on the indolo3,2-bcarbazole played important roles in tuning the photoelectronic properties. The dye D2 with 2, 8-substituted indolo3,2-bcarbazole core shows wider absorption spectrum and lower dye aggregation than D1 with 3,9-substituted isomer. The best power conversion efficiency (PCE) of 6.34% is obtained by the dye D2 due to its wider absorption spectra and strong steric hindrance, which can effectively suppress the undesirable dye aggregation. The co-sensitization of D1 and D2 enhances IPCE response in the visible light region and further improves the PCE up to 7.03%.
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Foam can improve the sweep efficiency and increase the oil displacement efficiency, which plays an important role in the oil exploitation of heterogeneous reservoirs. The ordinary ...core flooding experiments can not reflect the transport characteristics of foam inside the porous. While, experimental research on the foam displacement mechanism is mainly carried out by using a microfluidic visualization model, which is quite different from the actual reservoir conditions. In this study, a new method to visually study the displacement mechanism of foam in a heterogeneous core was established. MR(magnetic resonance) images and T2 (transverse relaxation time) spectrum were obtained for a heterogeneous core during foam injection. The corresponding relationships between the relaxation time region and the fluid signal in the large/medium/small pores of the core were established and then used to describe the migration characteristics of foam in pores of different sizes. The effects of the foam parameters on the apparent viscosity of the foam and the sweep efficiency in high- and low-permeability layers were studied. The results showed that injection rates, gas-liquid ratios, and surfactant concentrations, could obviously influence the ability of foam to block the large pores and enhance the sweep efficiency in the medium and small pores. The injection parameters affected the apparent viscosity of the foam and the water saturation in each layer of heterogeneous core. It was demonstrated that the method could be used to screen the injection parameters of foam and evaluate the adaptability of the foam types in heterogeneous cores.
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