15 research outputs found
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Neutrophil-Mediated Experimental Metastasis Is Enhanced by VEGFR Inhibition in a Zebrafish Xenograft Model
Inhibition of VEGF signalling effectively suppresses localized tumour growth but accelerates tumour invasiveness and micrometastasis by unknown mechanisms. To study the dynamic and reciprocal interactions between tumour cells and their microenvironment during these processes, we established a xenograft model by injecting tumour cells into the blood circulation of transparent zebrafish embryos. This reproducibly results in rapid simultaneous formation of a localized tumour and experimental micrometastasis, allowing time-resolved imaging of both processes at single-cell resolution within 1 week. The tumour vasculature was initiated de novo by remodelling of primitive endothelial cells into a functional network. Roles of myeloid cells in critical tumourigenesis steps such as vascularization and invasion were revealed by genetic and pharmaceutical approaches. We discovered that the physiological migration of neutrophils controlled tumour invasion by conditioning the collagen matrix and forming the metastatic niche, as detected by two-photon confocal microscopy and second harmonic generation. Administration of VEGFR inhibitors blocked tumour vascularization and a localized tumour growth but enhanced migration of neutrophils, which in turn promoted tumour invasion and formation of micrometastasis. This demonstrates the in vivo cooperation between VEGF signalling and myeloid cells in metastasis and provides a new mechanism underlying the recent findings that VEGFR targeting can promote tumour invasiveness
Antagonistic effects of Talaromyces muroii TM28 against Fusarium crown rot of wheat caused by Fusarium pseudograminearum
Fusarium crown rot (FCR) caused by Fusarium pseudograminearum is a serious threat to wheat production worldwide. This study aimed to assess the effects of Talaromyces muroii strain TM28 isolated from root of Panax quinquefolius against F. pseudograminearum. The strain of TM28 inhibited mycelial growth of F. pseudograminearum by 87.8% at 72 h, its cell free fermentation filtrate had a strong antagonistic effect on mycelial growth and conidial germination of F. pseudograminearum by destroying the integrity of the cell membrane. In the greenhouse, TM28 significantly increased wheat fresh weight and height in the presence of pathogen Fp, it enhanced the antioxidant defense activity and ameliorated the negative effects of F. pseudograminearum, including disease severity and pathogen abundance in the rhizosphere soil, root and stem base of wheat. RNA-seq of F. pseudograminearum under TM28 antagonistic revealed 2,823 differentially expressed genes (DEGs). Most DEGs related to cell wall and cell membrane synthesis were significantly downregulated, the culture filtrate of TM28 affected the pathways of fatty acid synthesis, steroid synthesis, glycolysis, and the citrate acid cycle. T. muroii TM28 appears to have significant potential in controlling wheat Fusarium crown rot caused by F. pseudograminearum
The rise of social media in China seen through the prism of societal transformations : analysis of the birth and development of Chinese cyber-space between 1998 and 2016
Dans un pays comme la Chine, où fonctionne un régime politique de front unique du Parti communiste, le système médiatique est caractérisé par la propagande, la concordance des points de vue et le secret. Au fur et à mesure du développement d’Internet et des réseaux sociaux, les citoyens chinois, en particulier les jeunes, se sont saisis de cet espace public numérique pour échanger des opinions en tâchant de contourner les médias de masse dominants officiels. La mobilisation en ligne des citoyens suscite un nouveau phénomène socio-politique en Chine. Notre recherche porte sur les usages du Web par la génération post-80 et les représentations qui sous-tendent ses expressions et actions en ligne. En analysant soixante-neuf entretiens semi-directifs réalisés avec des internautes répartis en quatre catégories, nous avons observé leurs réactions vis-à -vis d’affaires publiques controversées. Nous avons particulièrement interrogé ces jeunes cyber-citoyens sur les quatre réactions possibles à la censure d’Internet : l’indifférence, le silence, l’autocensure, et surtout la résistance. Aujourd’hui, le cyberespace n’est pas seulement une plate-forme de propagande pour restaurer et maintenir l’autorité du Parti communiste, mais aussi un espace où les citoyens s’accordent ou s’opposent dans des conversations interminables en ligne et hors ligne. Cela peut pousser certaines organisations officielles ou non-gouvernementales à résoudre des problèmes sociaux et/ou politiques. Dans ce contexte, nous cherchons à analyser le rôle socio-politique de l’espace public numérique et à vérifier s’il pourrait être une variante de la sphère publique habermassienne et exercer une influence sur la démocratie électronique dans la Chine contemporaine.In China, the political regime is the united front, which supports, reinforces the leadership of the Communist Party and makes a media system characterised by secret, propaganda and unanimity of viewpoints. With the development of the Internet, Chinese citizens, especially the younger demographic, take advantage of the online public escape to express themselves and exchange ideas, by bypassing dominant mass media. The online mobilisation of Chinese citizens raises a new and interesting socio-political phenomenon. Therefore, our research will examine the web habits of the post-80's generation and to explore the representations that underly their online behaviour. From the analysis of semi-structured interviews carried out with 69 cyber citizens, which are classified by four categories, we observed their reactions to controversial public affairs. The analysis aims to identify four possible reactions to online censorship: indifferent attitudes, silence, self-censorship, and the resistance. It is noticeable that today cyberspace is not just a propaganda platform aimed at restoring and maintaining the Communist party’s authority, but also a wide-open space where citizens agree or disagree in endless controversies online and below the line. This may push some official or non-governmental organisations to solve social and/or political problems. In this context, we seek to analyse the socio-political role of the digital public space and to verify if it could be a variant of the Habermasian public sphere and influence e-democracy in contemporary China
Synergism of cisplatin-oleanolic acid co-loaded hybrid nanoparticles on gastric carcinoma cells for enhanced apoptosis and reversed multidrug resistance
Combined administration of different drugs is a widely acknowledged approach for effective cancer therapy. However, the limited targeting, as well as inferior drug loading capacities of current drug delivery systems (DDS), are still the bottleneck for better performance in cancer treatment. Herein, we successfully developed a cancer cell membrane (CM) decorated calcium carbonate (CC) hybrid nanoparticles (HN) for the co-delivery of cisplatin (CDDP) and oleanolic acid (OA). The physicochemical property of HN/CDDP/OA was evaluated, which revealed that the as-prepared DDS was core-shell structured and well-dispersed nanoparticles with size around 100 nm. The HN/CDDP/OA showed high stability and biocompatibility with pH-responsive drug release. Moreover, the CM modification in HN also demonstrated highly elevated tumor-homing nature than bare CC. Finally, the feasibility of HN/CDDP/OA in the treatment of gastric cancer (MGC-803 cell line) was assessed. HN/CDDP/OA showed better performance than mono systems with enhanced apoptosis and capable of reversing multidrug resistance (MDR) of cancer cells
Parotid tumors and their postoperative complications: A 5-year experience
Introduction: Understanding the pathophysiology, clinical characteristics, and postoperative complications of parotid tumors is crucial in light of the growing emphasis on the occurrence and development of parotid tumor disease. Materials and methods: The study population consisted of 387 cases of primary parotid tumors treated surgically at our institution between July 2015 and November 2020. We statistically analyzed the gender, age, and pathological findings of patients, 307 of whom underwent postoperative return visits and were included in the study of postoperative complications. Results: The ratio of male to female parotid tumor patients was 1.39:1, and the best possible age range was between 51 and 60 years. The percentage of benign to malignant tumors (342/45) was 7.6:1. Pleomorphic adenoma constituted the majority of benign tumors. Adenoid cystic carcinoma constituted the majority of malignant tumors.The sensory deficit of the auricle, salivary fistula, facial nerve paralysis, and Frey's syndrome were the most prevalent postoperative complications of parotid tumors. Conclusions: Our efforts should focus on active prevention and treating parotid tumor postoperative complications
Genome-Wide Identification of <i>BrCAX</i> Genes and Functional Analysis of <i>BrCAX1</i> Involved in Ca<sup>2+</sup> Transport and Ca<sup>2+</sup> Deficiency-Induced Tip-Burn in Chinese Cabbage (<i>Brassica rapa</i> L. ssp. <i>pekinensis</i>)
Calcium (Ca2+) plays essential roles in plant growth and development. Ca2+ deficiency causes a physiological disorder of tip-burn in Brassiceae crops and is involved in the regulation of cellular Ca2+ homeostasis. Although the functions of Ca2+/H+ exchanger antiporters (CAXs) in mediating transmembrane transport of Ca2+ have been extensively characterized in multiple plant species, the potential roles of BrCAX genes remain unclear in Chinese cabbage. In this study, eight genes of the BrCAX family were genome-widely identified in Chinese cabbage. These BrCAX proteins contained conserved Na_Ca_ex domain and belonged to five members of the CAX family. Molecular evolutionary analysis and sequence alignment revealed the evolutionary conservation of BrCAX family genes. Expression profiling demonstrated that eight BrCAX genes exhibited differential expression in different tissues and under heat stress. Furthermore, Ca2+ deficiency treatment induced the typical symptoms of tip-burn in Chinese cabbage seedlings and a significant decrease in total Ca2+ content in both roots and leaves. The expression changes in BrCAX genes were related to the response to Ca2+ deficiency-induced tip-burn of Chinese cabbage. Specially, BrCAX1-1 and BrCAX1-2 genes were highly expressed gene members of the BrCAX family in the leaves and were significantly differentially expressed under Ca2+ deficiency stress. Moreover, overexpression of BrCAX1-1 and BrCAX1-2 genes in yeast and Chinese cabbage cotyledons exhibited a higher Ca2+ tolerance, indicating the Ca2+ transport capacity of BrCAX1-1 and BrCAX1-2. In addition, suppression expression of BrCAX1-1 and BrCAX1-2 genes reduced cytosolic Ca2+ levels in the root tips of Chinese cabbage. These results provide references for functional studies of BrCAX genes and to investigate the regulatory mechanisms underlying Ca2+ deficiency disorder in Brassiceae vegetables
Design and Testing of an Elastic Comb Reciprocating a Soybean Plant-to-Plant Seedling Avoidance and Weeding Device
Although there are existing interplant weed control devices for soybeans, they mostly rely on image recognition and intelligent navigation platforms. Simultaneously, automated weed control devices are not yet fully mature, resulting in issues such as high seedling injury rates and low weeding rates. This paper proposed a reciprocating interplant weed control device for soybeans based on the idea of intermittent reciprocating opening and closing of weeding execution components. The device consists of a laser ranging sensor, servo motor, Programmable Logic Controller (PLC), and weeding mechanism. Firstly, this paper explained the overall structure and working principle of the weed control device, and discussed the theoretical analysis and structural design of the critical component, elastic comb teeth. This paper also analyzed the working principle of the elastic comb teeth movement trajectory and seedling avoidance action according to soybean agronomic planting requirements. Then, field experiments were conducted, and the experiment was designed by the quadratic regression general rotation combination experimental method. The number of combs, the speed of the field management robot, and the stabbing depth were taken as the test factors to investigate their effects on the test indexes of weeding rate and seedling injury rate. The experiment utilized a response surface analysis method and designed a three-factor, three-level quadratic regression general rotation combination experimental method. The results demonstrate that the number of comb teeth has the most significant impact on the weeding rate, while the forward speed has the most significant impact on the seedling injury rate. The optimal combination of 29.06 mm stabbing depth, five comb teeth, and a forward speed of 0.31 m/s achieves an optimal operational weeding rate of 98.2% and a seedling injury rate of 1.69%. Under the optimal parameter combination conditions, the machine’s performance can meet the requirements of intra-row weeding operations in soybean fields, and the research results can provide a reference for the design and optimization of mechanical weed control devices for soybean fields
Design and Fabrication of a Thermopile-Based Thin Film Heat Flux Sensor, Using a Lead—Substrate Integration Method
An accurate and continuous measurement of heat flux is needed in many long-term operation facilities in order to monitor and improve the life of its machinery. A thin film heat flux sensor is usually fabricated via sputtering, according to different spatial arrangements of thermocouple junctions. A novel thin film heat flux sensor was designed, fabricated, and calibrated, but the connection between the thin film and the leads could not be fixed quickly and steadily. For this purpose, in this paper a method to seamlessly integrate the leads and the thin film has been proposed to improve the sensor output signal. The sensor is capable of simultaneously measuring surface heat flux and temperature magnitude, to address the current situation of the single design of heat flux sensors. The novel thin film heat flux sensor is structured as follows: Thirty pairs of NiCr-NiSi thermocouple junctions are deposited in an annular pattern on a well-designed ceramic substrate. Over the annular thermopile, a 2000 nm-thick thermal insulator layer is deposited to create a temperature gradient across the layers. In addition, in this study a new calibration method was used to evaluate the static and dynamic properties of this novel thin film heat flux sensor. The analysis and experimental results show that the heat flux calculated from the sensor output was in good agreement with the value obtained from the pre-calibrated standard sensor. The sensitivity and response time of the novel sensor were measured at 0.06 mV/(kW/m2) and 475 ms, respectively. The heat flux measurements made with the sensor presented good repeatability. The heat-transfer coefficient of the Al2O3 thin film was 4.477 w/(m∙k) for the novel thin film heat flux sensor described in this paper
LncTUG1 ameliorates renal tubular fibrosis in experimental diabetic nephropathy through the miR-145-5p/dual-specificity phosphatase 6 axis
AbstractThe renal interstitial fibrosis contributes to the progression and deterioration of diabetic nephropathy (DN). Long noncoding RNA taurine-up-regulated gene 1 (TUG1) in kidneys may be down-regulated by hyperglycemia. We aim to explore its role in tubular fibrosis caused by high glucose and the possible target genes of TUG1. In this study, a streptozocin-induced accelerated DN mouse model and a high glucose-stimulated HK-2 cells model was established to evaluate TUG1 expression. Potential targets of TUG1 were analyzed by online tools and confirmed by luciferase assay. A rescue experiment and gene silencing assay were used to investigate whether TUG1 plays its regulation role via miR-145-5p/dual-specificity phosphatase 6 (DUSP6) in HK2 cells. The effects of TUG1 on inflammation and fibrosis in high glucose treated tubular cells were evaluated by in vitro study, as well as in vivo DN mice model through AAV-TUG1 delivery. Results showed TUG1was downregulated in HK2 cells incubated with high glucose while miR-145-5p was upregulated. Overexpression of TUG1 alleviated renal injury by suppressing inflammation and fibrosis in vivo. Overexpression of TUG1 inhibited HK-2 cell fibrosis and relieved the inflammation. A mechanism study demonstrated that TUG1 directly sponged to miR-145-5p, and DUSP6 was identified as a target downstream of miR-145-5p. In addition, miR-145-5 overexpression and DUSP6 inhibition countervailed the impacts of TUG1. Our findings revealed that TUG1 overexpression alleviates kidney injury in DN mice and decreases the inflammatory response and fibrosis of high glucose-stimulated HK-2 cells via miR-145-5p/DUSP6 axis