Search

Carbon/carbon (C/C) composites have received considerable attention for one of the most promising materials in thermal-structural applications owing to their low density, excellent mechanical strength at high temperature, and superior thermal shock resistance. However, C/C composites are susceptible to destructive oxidation in atmospheric environment at high temperature. Matrix modification by adding ultra-high-temperature ceramics (UHTCs) into carbon substrate has been proved to be a favorable route to achieve the improved ablation resistance of C/C composites. In this work, the main fabrication approaches of UHTCs-modified C/C composites were summarized, including chemical vapor infiltration/deposition, precursor infiltration and pyrolysis, reactive melt infiltration, and slurry infiltration, and the advantages and drawbacks of each process were also briefly analyzed. In addition, anti-ablation properties of UHTCs-modified C/C composites under different ablation tests with different shape specimens were introduced. Finally, some likely future challenges and research directions in the development and application of these materials were presented.

What is known and the objective Our previous studies have shown that saponins of Sanguisorba parviflora (Maxim) Takeda (Sp. T) relieved cyclophosphamide-induced myelosuppression in mice with leukopenia. The hematopoietic cell-specific protein 1-associated protein X-1 (HAX-1) participated in the survival of neutrophils through the regulation of mitochondrial function. This study aimed to comprehensively identify the role of HAX-1 in Sp. T to alleviate leukopenia. Methods HAX-1 expression was examined in the peripheral blood neutrophils using real-time polymerase chain reaction (PCR), Western blot analysis and immunohistochemical staining. Neutrophil apoptosis was measured by flow cytometry. Mitochondrial function was evaluated via reactive oxygen species (ROS) generation and mitochondrial membrane potential (ΔΨm) integrity. Results and discussion Our study indicated that the expression of the HAX-1 gene was significantly decreased in the peripheral blood neutrophils of leukopenia patients compared with healthy donors. The saponins of Sp. T induced HAX-1 expression and promoted myeloid progenitor cell (mEB8-ER cell) viability, while overexpression of HAX-1 reduced the production of reactive oxygen species (ROS) and maintained the integrity of the mitochondrial membrane potential. Cyclophosphamide-induced mitochondrial dysfunction and apoptosis could be abrogated by treatment with Sp. T or the addition of metformin. What is new and our conclusion Our data support a mechanism where Sp. T protects against chemotherapy-induced leukopenia by regulating HAX-1 gene expression in a mitochondrial-dependent manner.

The nonlinear differential equation option pricing formula is invaluable in financial derivatives investment risk assessment. This article applies the theory of nonlinear differential equations to deal with financial risks in commodity and currency markets. Through this condition, we obtain the fair price process of contingent rights under the classic Black-Scholes model and the price process of the optimal growth investment strategy. The results show that the risk measurement under stable distribution is suitable for investors to manage risk.

MiRNA-126 (miR-126) has been shown to be involved in various malignancies as well as other biological processes. However, currently, its role in esophageal squamous cell carcinoma (ESCC) is not well understood. The present study is focused on the mechanisms that underlie the effect of miR-126 on cell survival and death (apoptosis and autophagy) in ESCC cells. MiR-126 expression was found to be enhanced in ESCC cells and tissues. Downregulation of miR-126 suppressed cell survival, and TUNEL staining indicated that miR-126 inhibition promoted ESCC cell death. In addition, the production of LC3B and p62 proteins, two autophagy signals, was reduced following miR-126 inhibition. A dual luciferase reporter assay demonstrated that the STAT3 3’-UTR is a direct target of miR-126. Furthermore, STAT3 knock-down rescued the effects on autophagy and apoptosis caused by miR-126 inhibition in ESCC cells. The results of this study may provide some insight into the molecular and biological mechanisms underlying ESCC generation and contribute to the development of novel therapeutic approaches for ESCC.

A randomized, open-label, parallel-controlled study was conducted to compare the efficacy of two kind of three-drug Regimens containing olanzapine/dexamethasone for the prevention of CINV induced by hyperemetic chemotherapy. The results showed that there was no significant difference in the complete response rates of nausea and vomiting between the two groups. However, the anxiety, depression and sleep quality of the patients in the olanzapine group were improved. It was concluded that the three-drug antiemetic regimen of "olanzapine +palonosetron+fosaprepitant" could effectively prevent CINV caused by hyperemetic chemotherapy, and its effect was similar to that of the antiemetic regimen containing dexamethasone. In addition, the anxiety, depression and sleep disorders of patients in the olanzapine group were all improved to different degrees.Our study has provided a theoretical basis for the clinical application of the three-drug regimen of "dexamethasone removal".

Two novel, Gram-stain-positive, non-motile, facultatively anaerobic, rod-shaped bacteria (strains 2129T and 2119) were isolated from the faeces of Tibetan antelopes (Pantholops hodgsonii) on the Qinghai-Tibet Plateau, PR China. The 16S rRNA gene sequences of the strains showed highest similarity values to Actinomyces timonensis DSM 23838T (92.9 and 92.8 %, respectively), and phylogenetic analysis based on 16S rRNA gene and genomic sequences indicated that strains 2129T and 2119 represent a new lineage. Strains 2129T and 2119 could ferment d-adonitol and d-xylose, but were unable to utilize d-mannose and d-melibiose nor produce esterase (C4) and proline arylamidase. The G+C contents of the two strains were both 69.0 mol%. Their genomes exhibited less than 40.4 % relatedness in DNA-DNA hybridization tests (below 70 % as the recommended threshold for new species) with all available genomes of the genus Actinomyces in the NCBI database. The major fatty acids of the two strains were C18 : 1ω9c and C16 : 0, and the major polar lipids were diphosphatidylglycerol, glycolipid, phosphatidylinositol, phosphatidyl inositol mannoside and phosphoglycolipid. Based on the results of genotypic, phenotypic and biochemical analyses, it is proposed that the two unidentified bacteria be classified as representing a novel species, Actinomyces lilanjuaniae sp. nov. The type strain is 2129T (=CGMCC 4.7483T=DSM 106426T).

This research aims to investigate the ameliorative potential of baicalin on lipopolysaccharide-induced acute lung injury by the suppression of oxidative stress and inflammation via the activation of the nuclear erythroid factor 2 (Nrf2)-mediated heme oxygenase-1 (HO-1) signaling pathway. Specific pathogen-free male mice, weighing between 25 and 30 g, were divided into the following four groups of 10 mice each: the control group, LPS group, LPS + baicalin group, and baicalin group. Bronchoalveolar lavage fluid (BALF), blood, and tissue were collected on the 16th day and used for hematological (total leukocyte, macrophage, neutrophil, and lymphocyte counts in both blood and BALF, biochemical (antioxidant enzymes, MDA, Nrf2, and HO-1), and histological analyses. The protective effect of baicalin on lipopolysaccharide-induced acute lung injury is based on its antioxidative stress capabilities that are mediated partly by the Nrf2/HO-1 signaling pathway. Baicalin pretreatment significantly decreased the rise in the lung injury score; total leukocyte, neutrophil, lymphocyte, and macrophage counts; pro-inflammatory mediators, tumor necrosis factor (TNF-α), interleukins (IL-6 and IL-1β); biosynthesis of oxidative products, e.g., malondialdehyde (MDA); and restoration of antioxidative enzyme (superoxide dismutase and catalase) activities by improving the expression of nuclear Nrf2 and cytosolic HO-1 in lipopolysaccharide-induced acute lung injury. The protective effects of baicalin are partly due to its antioxidant and anti-inflammatory effects. Our findings indicate that baicalin protects against lipopolysaccharide-induced severe lung injury by enhancing antioxidant systems and significantly reducing both inflammatory cells and mediators via the Nrf2-mediated HO-1 signaling pathway.

Wildlife is a reservoir of emerging infectious diseases of humans and domestic animals. Marmota himalayana mainly resides 2800–4000 m above sea level in the Qinghai-Tibetan Plateau, and is the primary animal reservoir of plague pathogen Yersinia pestis. Recently we isolated a new species, Escherichia marmotae from the faeces of M. himalayana. In this study we characterised E. marmotae by genomic analysis and in vitro virulence testing to determine its potential as a human pathogen. We sequenced the genomes of the seven E. marmotae strains and found that they contained a plasmid that carried a Shigella-like type III secretion system (T3SS) and their effectors, and shared the same O antigen gene cluster as Shigella dysenterae 8 and E. coli O38. We also showed that E. marmotae was invasive to HEp-2 cells although it was much less invasive than Shigella. Thus E. marmotae is likely to be an invasive pathogen. However, E. marmotae has a truncated IpaA invasin, and lacks the environmental response regulator VirF and the IcsA-actin based intracellular motility, rendering it far less invasive in comparison to Shigella. E. marmotae also carried a diverse set of virulence factors in addition to the T3SS, including an IS1414 encoded enterotoxin gene astA with 37 copies, E. coli virulence genes lifA/efa, cif, and epeA, and the sfp gene cluster, Yersinia T3SS effector yopJ, one Type II secretion system and two Type VI secretion systems. Therefore, E. marmotae is a potential invasive pathogen.

Hyperspectral imaging has the ability for characteristic identification because of its rich physical and chemical information. To develop online or portable devices for industrial applications, informative spectral bands relevant to the specific objects are needed to be selected. The neighborhood rough set (NRS) theory is an effective tool for selecting bands. The hyperspectral datasets gathered from practical applications often contain noise. The performance of band selection algorithm is adversely influenced by noise. In this paper, the performance of the band selection algorithm in the presence of class noise was assessed, which based on consistency measure, dependency measure and information measure of the NRS theory. The robustness and classification performance of algorithms for soybean and maize classification using hyperspectral imaging were compared systematically under different levels of noise. The results demonstrate that the robustness and classifying ability of all algorithms decreases in general when the number of mislabeled samples increases in training dataset and testing datasets. Compared with other algorithms based on the NRS theory and some classic algorithms (uninformative variable elimination and successive projections algorithm), the variable precision neighborhood rough set algorithm is proven to be superior. It is more robust and more accurate when class noise occurs in training dataset or testing datasets. This research not only highlights the strong and weak characteristics of the different approaches for different levels of noise, but also provides effective solutions in handling class noise.

Background: Non-small cell lung cancer (NSCLC) has a significant impact on human health. The aim of this study was to explore the role of long non-coding RNA DLX6-AS1 in the proliferation, migration, and invasion of NSCLC cells. Methods: The expression of DLX6-AS1 in NSCLC tumor tissues and cell lines was examined by qRT-PCR. The effects of DLX6-AS1 knockdown on cell proliferation, migration, and invasion were assessed by Cell Counting Kit-8, wound healing, and transwell assays, respectively. Bioinformatics analyses, luciferase reporter assays, and RNA pull-down assays were employed to examine the mechanism by which DLX6-AS1 exerted its oncogenesis effects in NSCLC. The anti-tumor effect of silencing DLX6-AS1 in vivo was also evaluated. Results: DLX6-AS1 was over-expressed in NSCLC tumor tissues and cell lines and its level of expression was found to be associated with tumor size and advanced clinical stage in patients with NSCLC. Downregulation of DLX6-AS1 inhibited cell proliferation, cell clone formation, migration, and invasion of NSCLC cells. DLX6-AS1 was found to interact with miR-27b-3p/GSPT1. DLX6-AS1 expression was negatively correlated with miR-27b-3p expression, but positively correlated with GSPT1 expression in NSCLC samples. DLX6-AS1 knockdown also effectively suppressed tumor growth in an in vivo xenograft model. Conclusion: DLX6-AS1 regulated NSCLC progression by targeting the miR-27b-3p/GSPT1 axis, which may provide novel insights for NSCLC prognosis and therapy.

What is known and objective We have previously shown that the saponins of Sanguisorba parviflora (Maxim.) Takeda (Sp. T) relieved cyclophosphamide-induced myelosuppression in leukopenic mice. Haematopoietic cell-specific protein 1-associated protein X-1 (HAX-1) participated in the survival of neutrophils through the regulation of mitochondrial function. The aim of the present study was to comprehensively identify the role of HAX-1 in the mechanism of leukopenia alleviation by Sp. T. Methods HAX-1 gene and protein expression levels in peripheral blood neutrophils were examined using real-time quantitative reverse transcription-polymerase chain reaction, western blot and immunohistochemical assays. Neutrophil apoptosis was measured using flow cytometry. Mitochondrial function was determined via assessments of the reactive oxygen species (ROS) generation and mitochondrial membrane potential (ΔΨm) integrity levels. Results and discussion The HAX-1 gene expression level in the peripheral blood neutrophils was significantly lower in patients with leukopenia than in healthy donors. The saponins of Sp. T induced HAX-1 expression and promoted myeloid progenitor cell (mEB8-ER cell) viability. HAX-1 overexpression reduced the production of ROS and maintained ΔΨm integrity. Cyclophosphamide-induced mitochondrial dysfunction and apoptosis could be abrogated by treatment with Sp. T or metformin. What is new and conclusion Our data suggest a mechanism through which Sp. T protects against chemotherapy-induced leukopenia by regulating HAX-1 gene expression in a mitochondrial-dependent manner.

e21011 Background: EGFR exon 20 mutations are associated with acquired resistance to EGFR tyrosine kinase inhibitors (TKIs). EGFR exon 20 mutations are usually not present alone, suggesting a more complex subtype of exon 20 mutations. Methods: In this study, we retrospectively analyzed the different subtypes and compound mutation profiles of EGFR 20 mutations. A total of 1,233 NSCLC patients’ tumors were collected and the mutations were detected by next-generation sequencing (NGS) from May 2020 to June 2021. Results: A total of 415 NSCLC patients' tumors harbored EGFR exon 20 mutations, accounting for 33.66% of the entire EGFR mutation cohort. Among these 415 patients, most of mutations were single-nucleotide variant (SNV) (379; 91.33%), and a few were indel or insertion mutations (39; 9.40%). The insertions were all in the back of exon 20, which were resistant to EGFR-TKIs. In addition, the subtypes of SNV were concentrated in T790M (270; 71.24%), S768I (48; 12.66%) and C797S (33; 8.71%), and all T790M mutations were accompanied by other mutations. Notably, the compound mutations of exon 20 have also been analyzed in this study. EGFR exon 20 combined with other EGFR mutations were detected in 345 patients. The compound mutations of exon 20-18, exon 20-19, exon 20-20 and exon 20-21 were detected in tumors from 52 (15.07%), 163 (47.25%), 43 (12.46%) and 140 (40.58%) patients respectively. Remarkably, the compound mutation subtype of exon 20-20 was T790M/C797X (29; 67.55%) and exon 20-21 was T790M/L858R (124; 88.57%). Conclusions: Diverse patterns of SNV mutations are seen in EGFR exon 20 mutations tumors. EGFR 20 mutations often accompany other mutations, which are associated with resistance to EGFR-TKIs. These data may help avoid the resistance of future adjuvant targeted therapy.

BACKGROUND Patients with aortic dissection during pregnancy and postpartum period exhibit a high mortality. At present, a complete overview of aortic dissection during pregnancy and postpartum period is lacking. ​Methods: This systematic review included 80 reports published from 2000 to 2020, comprising a total study population of 103 patients with aortic dissection. ​Results: We found that Stanford Type A aortic dissection was more common in prepartum cases, especially in the third trimester, while postpartum cases of aortic dissection were more common in Stanford Type B. The most common risk factor was connective tissue disease, with no other known risk factors. The mode of delivery had no significant effect on the type of postpartum aortic dissection. Reduced maternal and fetal mortality was observed when patients with Stanford Type A aortic dissection occurring after 28 gestational weeks underwent cesarean section followed by aortic replacement. Patients with Stanford Type B aortic dissection were treated mainly with medication and/or endovascular repair. ​Conclusion: Contemporary management of patients during pregnancy and within 12 weeks postpartum requires multidisciplinary cooperation and includes serial, noninvasive imaging, biomarker testing, and genetic risk profiling for aortopathy. Early diagnosis and accurate treatment are essential to reduce maternal and fetal mortality.

In the green pepper harvesting robot, the color of green pepper is similar to that of leaves, which makes it difficult to recognize the green pepper target. In order to solve this problem, a green pepper recognition method based on least-squares support vector machine optimized by the improved particle swarm optimization (IPSO-LSSVM) is proposed in this paper. Firstly, the green pepper images are segmented by K-Means method under the Lab color space, and the segmentation images of the target and background are obtained. The processed green pepper image was divided into training and testing samples. Then, the shape and texture features of green pepper targets are extracted separately from the training sample using the hu invariant moment and Tamura texture feature. Meanwhile, in order to reduce the complexity of data calculations and improve the efficiency, the extracted feature vectors are normalized. The feature vector is used as the input eigenvector of the least-squares support vector machine (LSSVM). The particle swarm optimization algorithm is used to obtain the optimal regularization parameter and the kernel function width. In order to maintain the particle activity, the mutation strategy is introduced to improve the particle swarm optimization algorithm. The experimental results show that the recognition rate of IPSO-LSSVM is higher than that of other methods, and the recognition accuracy is 89.04%. It could meet the requirements of green pepper identification.

The level of teaching management in colleges and universities affects the quality of teaching management in colleges and universities, teaching quality in colleges and universities, and further affects the quality of personnel training in colleges and universities. At present, Southwest Petroleum University is strengthening the management of teaching and improving its management level. There are many factors affecting the teaching management level and quality of Southwest Petroleum University. As one of the main carriers of teaching management of Southwest Petroleum University, students have important theoretical and practical significance in improving the management level by evaluating the teaching management satisfaction and finding out the existing problems and solutions. This study first summarizes the problems existing in the daily teaching management, teaching guarantee management and teaching quality management of Southwest Petroleum University. Secondly, it analyses the causes of the problems. Finally, it puts forward the corresponding solutions to the problems and causes.

A novel, Gram-stain-positive, catalase-positive, non-spore-forming, short rod-shaped strain (VUL4_3T) was isolated from rectal swabs of Old World vultures (Aegypius monachus) from the Tibet–Qinghai Plateau, China. Based on the results of biochemical tests and 16S rRNA gene sequence comparison, strain VUL4_3T was determined to be a member of the genus Actinomyces that is closely related to the type strains of Actinomyces liubingyangii (97.7 % 16S rRNA gene sequence similarity) and Actinomyces marimammalium (96.5 %). Optimal growth occurred at 37 °C, pH 6–7 and with 1 % (w/v) NaCl. The typical major cellular fatty acids of strain VUL4_3T were C18 : 1ω9c, C16 : 0 and C18 : 0. The VUL4_3T genome contained 2 207 832 bp with an average G+C content of 51.9 mol%. DNA–DNA hybridization values between strain VUL4_3T and the above two species of the genus Actinomyces showed less than 32 % DNA–DNA relatedness, supporting a novel species status of strain VUL4_3T. Based on the phenotypic data and phylogenetic inference, the novel species Actinomyces tangfeifanii sp. nov. is proposed. The type strain is VUL4_3T (=CGMCC 4.7369T=DSM 103436T).

Pancreatic cancer is one of the deadliest cancers with rapid disease progression. Further elucidation of its underlying molecular mechanisms and novel biomarkers for early detection is necessary. Exosomes are small extracellular vesicles that are released by multiple cell types acting as message carriers during intercellular communication and are promising biomarker candidates. However, the role of pancreatic cancer cell-derived exosomes in cancer progression and the application of these vesicles as novel diagnostic biomarkers have not been fully studied. In this study, we found that PC-1.0 (a highly malignant pancreatic cell line) cell-derived exosomes could be taken up by and enhance PC-1 (a moderately malignant pancreatic cell line) cell proliferation, migration and invasion abilities. We identified ZIP4 as the most upregulated exosomal protein in PC-1.0 cells from our proteomic analysis. In vitro and in vivo (a subcutaneous BALB/c nude mouse model) studies showed that exosomal ZIP4 can significantly promote pancreatic cancer growth. Using clinical blood samples, we compared the diagnostic values of serum exosomal ZIP4 levels between malignant pancreatic cancer patients (n = 24) and benign pancreatic disease patients (n = 32, AUC = .89), and between biliary disease patients (n = 32, AUC = .8112) and healthy controls (n = 46, AUC = .8931). In conclusion, exosomal ZIP4 promotes cancer growth and is a novel diagnostic biomarker for pancreatic cancer.

An administrative border might hinder the optimal allocation of a given set of resources by restricting the flow of goods, services, and people. In this paper, we address the question: Do administrative borders lead to poor accessibility to public service? In answering the question, we have examined the case of Sweden and its regional administrative borders and hospital accessibility. We have used detailed data on the Swedish road network, its hospitals, and its geo-coded population. We have assessed the population's spatial accessibility to Swedish hospitals by computing the inhabitants' distance to the nearest hospital. We have also elaborated several scenarios ranging from strongly confining regional borders to no confinements of borders and recomputed the accessibility. Our findings imply that administrative borders are only marginally worsening the accessibility.

Background The role of right atrial (RA) dysfunction in patients with pulmonary hypertension (PH), as evaluated by two-dimensional speckle-tracking echocardiography (2D-STE) remains to be determined. Methods Sixty consecutive PH patients and 30 healthy volunteers were included. RA function was evaluated by 2D-STE, and the following parameters were recorded: an average longitudinal strain (LS) curve that included LSpos during RA filling and LSneg representing RA active contraction (their summation is LStot), the phasic RA volumes, total RA emptying fraction, and the ratio of RA passive and active emptying to total emptying. The associations between these indices and the results of invasive pulmonary hemodynamics, cardiac structure and function, and NT-terminal pro brain natriuretic peptide (NT-proBNP) level were evaluated. Results LStot, total RA emptying fraction, LSpos, passive RA emptying fraction were significantly lower, while the contribution of active RA empting fraction/total RA emptying fraction was higher in PH patients than in controls. Among PH patients, LStot was negatively correlated with greater RA size, RA pressure, and pulmonary vascular resistance, but not pulmonary artery pressure, while LStot was also negatively associated with right ventricular enlargement and higher NT-proBNP. In receiver–operator characteristic analysis, RA LStot was of optimal accuracy for prediction of WHO-function class ≥III in PH patients. Conclusions PH was associated with impaired reservoir and conduit function, but enhanced active contract function of RA, while RA LStot confers an optimal predictive effect of poor WHO-function class in PH patients.

Two strains (pika_113T and pika_114) of a previously undescribed Actinomyces -like bacterium were recovered from the intestinal contents of plateau pika (Ochotona curzoniae) on the Tibet-Qinghai Plateau, China. Results from biochemical characterization indicated that the two strains were phenotypically homogeneous and distinct from other previously described species of the genus Actinomyces . Based on the comparison of 16S rRNA gene sequences and genome analysis, the bacteria were determined to be a hitherto unknown subline within the genus Actinomyces , being most closely related to type strains of Actinomyces denticolens and Actinomyces timonensis with a respective 97.2 and 97.1 % similarity in their 16S rRNA gene sequences. Phylogenetic analyses confirmed that pika_113T was well separated from any other recognized species of the genus Actinomyces and within the cluster with A. denticolens and A. timonensis. The genome of strain pika_113T displayed less than 42 % relatedness in DNA–DNA hybridization with all the available genomes of existing species of the genus Actinomyces in the NCBI database. Collectively, based on the phenotypic characteristics and phylogenetic analyses results, we propose the novel isolates as representatives of Actinomyces gaoshouyii sp. nov. The type strain of Actinomyces gaoshouyii is pika_113T (=CGMCC 4.7372T=DSM 104049T), with a genomic DNA G+C content of 71 mol%.

The present study aimed to evaluate hemodynamics and right ventricular function in patients with pulmonary hypertension (PH) using transthoracic echocardiography and to compare these results with measurements obtained using right-sided heart catheterization (RHC). A total of 75 patients with PH were examined using echocardiography and RHC. Patients were divided into the following two groups according to their difference between SPAPecho and SPAPRHC measurement: The overestimated group and underestimated group. The overestimated group included the subgroups groupover-A (difference