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Four new leucine-derived cytochalasans, possessing a 5,6,5,8-ring (

Background:The safe closure of atrial septal defect with deficient posterior-inferior or inferior vena cava rim is a controversial issue. Few studies have been conducted on the closure of atrial septal defect with deficient posterior-inferior or inferior vena cava rim without fluoroscopy. This study evaluated the feasibility and safety of echocardiography-guided transcatheter closure of atrial septal defect with deficient posterior-inferior or inferior vena cava rim.Methods:The data of 136 patients who underwent transcatheter atrial septal defect closure without fluoroscopy from March 2017 to March 2020 were retrospectively analysed. The patients were classified into the deficient (n = 45) and sufficient (n = 91) posterior-inferior or inferior vena cava rim groups. Procedure and the follow-up results were compared between the two groups.Results:Atrial septal defect indexed diameter and the device indexed diameter in the deficient rim group were both larger than that in the sufficient rim group (22.12 versus 17.38 mm/m2, p < 0.001; 24.77 versus 21.21 mm/m2, p = 0.003, respectively). There was no significant difference in the success rate of occlusion between two groups (97.78% in the deficient rim group versus 98.90% in the sufficient rim group, p = 1.000). During follow-up, the incidence of severe adverse cardiac events was not statistically significant (p = 0.551).Conclusions:Atrial septal defect with deficient posterior-inferior or inferior vena cava rim can safely undergo transcatheter closure under echocardiography alone if precisely evaluated with transesophageal or transthoracic echocardiography and the size of the occluder is appropriate. The mid-term results after closure are similar to that for an atrial septal defect with sufficient rim.

Colorectal cancer is a common malignancy with the third highest incidence and second highest mortality rate among all cancers in the world. Chemotherapy resistance in colorectal cancer is an essential factor leading to the high mortality rate. The ATP-binding cassette (ABC) superfamily G member 2 (ABCG2) confers multidrug resistance (MDR) to a range of chemotherapeutic agents by decreasing their intracellular content. The development of novel ABCG2 inhibitors has emerged as a tractable strategy to circumvent drug resistance. In this study, an ABCG2-knockout colorectal cancer cell line was established to assist inhibitor screening. Additionally, we found that ataxia-telangiectasia mutated (ATM) kinase inhibitor AZ32 could sensitize ABCG2-overexpressing colorectal cancer cells to ABCG2 substrate chemotherapeutic drugs mitoxantrone and doxorubicin by retaining them inside cells. Western blot assay showed that AZ32 did not alter the expression of ABCG2. Moreover, molecule docking analysis predicted that AZ32 stably located in the transmembrane domain of ABCG2. In conclusion, our result demonstrated that AZ32 could potently reverse ABCG2-mediated MDR in colorectal cancer.

Background: α-Aryl substituted nitroalkanes are important synthetic intermediates for the preparation of pharmaceutical molecules, natural products, and functional materials. Due to their scare existence in Nature, synthesis of these compounds has attracted the attention of synthetic and medicinal chemists, rendering α-arylation of nitroalkanes of an important research topic. This article summarizes the important advances of α- arylation of nitroalkanes since 1963. Results: After a brief introduction of the synthetic application and the reactions of nitroalkanes, this article reviewed the synthetic methods for the α-arylated aliphatic nitro compound. The amount of research on α-arylation of nitroalkanes using various arylation reagents and the discovery of elegant synthetic approaches towards such skeleton have been discussed. This review described these advances in two sections. One is the arylation of non-activated nitroalkanes, with an emphasis on the application of diverse arylation reagents; the other focuses on the arylation of activated nitroalkanes, including dinitroalkanes, trinitroalkanes, α-nitrosulfones, α-nitroesters, α-nitrotoluenes, and α-nitroketones. The synthetic application of these methods has also been presented in some cases. Conclusion: In this review, we described the progress of α-arylation of nitroalkanes. Although the immense amount of research on α-arylation of aliphatic nitro compounds has been achieved, many potential issues still need to be addressed, especially the asymmetric transformation and its wide application in organic synthesis.

This study fabricated flexible radar-absorbing knitted compound materials by weft knitting and blending ferromagnetic nickel micron-fibers and cotton fiber into structures with a concave–convex surface, including rhombic, mat, wavy, and leno stitches. The electromagnetic wave-absorbing capability and mechanical properties of the flexible radar-absorbing knitted compound materials were evaluated. The results showed that the rhombic, mat, and wavy stitches displayed high mechanical properties with high bursting strength and there were no significant differences among them. The rhombic stitch flexible radar-absorbing knitted compound material with a ferromagnetic nickel micron-fiber content of 14% had a maximum bandwidth of 13 GHz and achieved a minimum reflectance of −20 dB at 7 GHz, which was 150% that of mat fabric, and 200% that of wavy fabric and leno fabric. This was ascribed to the fact that the concave–convex surface with regular diamond-shaped block improved the dispersion of the electromagnetic wave, weakened the wave strength, and increased the interference. Therefore, the rhombic stitch flexible radar-absorbing knitted compound material was the most suitable for flexible radar-absorbing material in this study. The development of flexible radar-absorbing materials, by combining aerospace technology, military technology and textile technology, is important for the application in stealth of aircraft and weapons.

The structure of intestinal microbiota of black rockfish Sebastes schlegelii in five early development stages were determined in high throughput sequencing with Illumina MiSeq PE300 system. The relationship between intestinal microbial community and the environmental (including culture water and feed) microbiota and the abundance variation trends of core microbiota were investigated, based on which the source of some core microbiota was analyzed in this study. The results show that Proteobacteria and Firmicutes are the most dominant phyla in guts. At the genus level, there are obvious differences between the artificial breeding fish and wild adults in the intestinal microflora structure. The compositions of dominant genera are similar, although the structure of intestinal microbiota gradually changes with the growth of larvae and juveniles. The core microbiota including Bacillus, Acinetobacter, Pseudomonas, Lactobacillus, Lactococcus, Glaciecola, Vibrio, Pseudoalteromonas, Acidovorax, and Aliivibrio were determined in the analysis of dominant and shared species. Compared with the water, the effect of feed microbiota on the structure of the gut microbial community is more obvious. Moreover, the trends of Bacillus, Acinetobacter, Pseudomonas, Lactobacillus, Lactococcus, and Glaciecola were opposite to Vibrio and Pseudoalteromonas in the gut. The correlation analysis suggested that Acidovorax, Glaciecola, Pseudomonas, Lactobacillus, and Acinetobacter might transited from mainly the parents and/or came from the fertilization process. The relative results may provide a theoretical reference for selecting the native probiotics, and supply the basic data for artificially regulating the intestinal microbiota with probiotic during early developmental stage of black rockfish.

Four unprecedented yellow alkaloids named as taberbovines A-D (1-4) were isolated from stems of Tabernaemontana bovina Lour. Their structures were elucidated by the comprehensive spectroscopic data, computational chemistry, and X-ray crystal diffraction. Alkaloids 1-4 possessed a unique 6/6/5/6/5 ring system and were assigned to monoterpenoid quinolines. Biosynthetically, the isolated alkaloids may be derived from Aspidosperma-type alkaloid by oxidation and rearrangements. Taberbovines A-D exhibited the good inhibitory activities of formation NO in LPS induced RAW264.7 macrophages.

Both gonadotropin-inhibitory hormone (GnIH) and kisspeptin play a critical role in the control of reproduction in vertebrates. However, the spatial–temporal expression patterns and possible roles of these two peptides during development are poorly understood. To this end, we evaluated dynamic expression profiles of lpxrfa, the piscine ortholog of gnih, kisspeptin (kiss2) and their receptor mRNAs during embryogenesis and early larval development in a flatfish, Cynoglossus semilaevis. Quantitative RT-PCR analysis indicated that both ligand (lpxrfa and kiss2) and receptor (lpxrfa-r and kiss2r) mRNAs were detected in unfertilized eggs and during embryogenesis, but with different expression profiles. In addition, lpxrfa-r, kiss2 and kiss2r transcripts increased significantly at 6 days post-hatching (dph), while lpxrfa mRNAs did not vary significantly during all larval development. Taken together, these results of the present study suggest that both LPXRFa and kisspeptin systems could be functional and play differential roles during embryogenesis and early larval development in tongue sole.

This paper presents a new class of protocols to solve finite-time consensus for multi-agent systems. The protocols are induced from the classical finite-time consensus algorithm by using the so-called protocol function. Sufficient conditions are established for networked agents to experience finite-time consensus under time-varying undirected and fixed directed topologies. Numerical simulations show that the proposed protocols can provide more flexibility to improve convergence rate.

Hereditary effects of exponentially damped oscillators with past histories are considered in this paper. Nonviscously damped oscillators involve hereditary damping forces which depend on time-histories of vibrating motions via convolution integrals over exponentially decaying functions. As a result, this kind of oscillators are said to have memory. In this work, initialization for nonviscously damped oscillators is firstly proposed. Unlike the classical viscously damped ones, information of the past history of response velocity is necessary to fully determine the dynamic behaviors of nonviscously damped oscillators. Then, initialization response of exponentially damped oscillators is obtained to characterize the hereditary effects on the dynamic response. At last, stability of initialization response is proved and the hereditary effects are shown to gradually recede with increasing of time.

In this study, the complete mitochondrial genomic sequence of southern flounder Paralichthys lethostigma was determined. The circular mitogenome is 16 843 bp in length and encodes 37 typical animal mitochondrial genes and contains a putative D-loop region. Phylogenetic analysis based on the mitochondrial genomes of southern flounder indicated that P. lethostigma and P. olivaceus are the most closely related species, which strongly supports their close phylogenetic affinity.

Cartilage injury of the knee joint is very common. Due to the limited self-healing ability of articular cartilage, osteoarthritis is very likely to occur if left untreated. Bone marrow mesenchymal stem cells (BMMSCs) are widely used in the study of cartilage injury due to their low immunity and good amplification ability, but they still have disadvantages, such as heterogeneous undifferentiated cells. MicroRNAs can regulate the chondrogenic differentiation ability of MSCs by inhibiting or promoting mRNA translation and degradation. In this research, we primarily investigated the effect of microRNA-210-3p (miR-210-3p) on chondrogenic and adipogenic differentiation of BMMSCs in vitro. Our results demonstrate that miR-210-3p promoted chondrogenic differentiation and inhibited adipogenic differentiation of rat BMMSCs, which was related to the HIF-3α signalling pathway. Additionally, miR-210-3p promotes mRNA and protein levels of the chondrogenic expression genes COLII and SOX9 and inhibits mRNA and protein levels of the adipogenic expression genes PPARγ and LPL. Thus, miR-210-3p combined with BMMSCs is a candidate for future clinical applications in cartilage regeneration and could represent a promising new therapeutic target for OA.

In this study, we reported the complete chloroplast genome of Fortunella crassifolia Swingle using the HiSeq-4000 sequencing. The chloroplast genome size is 160,229 bp, which consists of a large single-copy region (87,774 bp), a small single-copy region (18,721 bp), and a pair of IR regions (26,867 bp). The chloroplast genome contains 114 unique genes, including 80 protein-coding genes, 30 tRNAs, and 4 rRNAs. Phylogenetic maximum likelihood analysis showed that F. crassifolia was closest to Hongkong kumquat (F. hindsii). The complete chloroplast genome would be subsequently used for citrus species researches.

In this paper, we propose an extraction method for landslide topographic features and based on these fine features, we trained a landslide stability classification model. Topographic factors have a huge impact on the stability of landslides, and our new feature extraction methods can provide more accurate portraits of landslides. Considering the factors affected landslide stability, this paper studied the factors used in traditional quantitative stability calculations and analyzed the factors affecting stability based on landslide data. So, the proposed method is a combination of theoretical method and numerical method. Based on support vector classification (SVC), random forest (RF), and extreme gradient boosting (XGBoost) models, this paper compares and analyzes the rationality and reliability of the landslide stability classification results output by three models. After adopting the new fine feature extraction method, the accuracy of the stable classification results has been improved by about 5% on average, and the interpretability of the classification results has also been greatly enhanced.

In landslide disaster prevention project, landslide profile is an important research object, which contains rich geological information of landslide. When we get the profile image of the landslide, if we can recommend several landslide cases with similar geological characteristics by the landslide profile image for research, the landslide disaster prevention project can be carried out quickly. In this paper, we propose a recommendation system based on similarity of landslide geological characteristics. The recommendation system is divided into two steps. Firstly, we construct a classification model to obtain the categories of landslide geological characteristics from the profile image by random forest algorithm and supervised machine learning approach. Then, according to the categories of landslide geological characteristics, the landslide case recommended model is constructed, and 5 landslide cases with similar geological characteristics are recommended for the landslide. According to the evaluation index of the recommendation system, the evaluation results show the effectiveness of the recommendation system.

House prices have received unusual attention in recent years, and evaluation of housing price has also become a research hotpot. Value of a house is considered as a mixture of various features, such as house type, orientation and location. Accurate assessment of houses thus faces a large number of challenges. Several methods have been applied to assess the value of a house, including geographically weighted regression and machine learning. However, every method has some limitations. The accuracy of traditional regression methods needs to be improved. Machine learning methods are weak in interpretability. In this paper, to analyze the housing price, we compared XBGoost, Random Forest, Support vector regression, back-propagation network and geographically weighted regression to model the second-hand housing price dataset, and analyzed the influenced of each feature. The result shows Random Forest reaches a lowest mean absolute error of 1517.29 and best r2 of 0.83. According to the constructed models, the importance values are given, and the area of house shows a strongest influence on housing price in the study area.

Measurement of turbulence intensity interference on the wake flow of a circular cylinder was conducted in the wind tunnel. Different turbulence intensity (3.2%, 8%) with the same mean velocity of incoming flows were created. This is to separate the turbulence intensity variations from the mean flow field. The separation of turbulence intensity from conventional mixing of the mean velocity and turbulence intensity has a merit to get a clear picture of turbulence intensity effect. The Reynolds number composed of the free incoming flow stream velocity and cylinder diameter is about 4,500. Effects of the turbulence intensity of incoming flow on the development of the mean velocity profile of wake flow and the vortex shedding behind the circular cylinder are presented.

Several convex hull manipulation methods have been proposed for tensor product (TP) model transformation, such as CNO, INO, IRNO, minimum volume simplex, and optimized CNO. Among the five ...

In the paper, Googol’s two-wheeled self-balancing robot is used in the controller design, which is introduced based on linear parameter varying technique and variable universe type-II fuzzy method. In the control process, the linear matrix inequality is used to solve the variable universe error and error derivative gain instead of the common linear quadratic regulator technique. In the case of disturbance, the position and yaw are controlled separately, the interval type-II fuzzy logic controller with linear matrix inequality will not stable, and the robot is out of balance when the disturbance increases to a certain degree. The variable universe interval type-II fuzzy logic controller are used to alleviate this problem, two interval type-II fuzzy logic controller are presented to the whole control scheme, and the self-balancing robot could reach the desired position asymptotically, and the body upright balance purpose are kept. It is found that the variable universe interval type-II fuzzy logic controller has better anti-disturbance ability and faster response speed due to the usage of type-II fuzzy sets and linear matrix inequalities.

The flocking problem of multi-agent systems with transmission delay is considered in this paper. We present a distributed flocking protocol and obtain a sufficient condition for the system to experience unconditional flocking by means of Lyapunov functional method. Numerical simulations are carried out to verify our theoretical results and also show that increasing delay may decrease the convergence rate of the system.