51 research outputs found

    Three-dimensional array of microbubbles sonoporation of cells in microfluidics

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    Sonoporation is a popular membrane disruption technique widely applicable in various fields, including cell therapy, drug delivery, and biomanufacturing. In recent years, there has been significant progress in achieving controlled, high-viability, and high-efficiency cell sonoporation in microfluidics. If the microchannels are too small, especially when scaled down to the cellular level, it still remains a challenge to overcome microchannel clogging, and low throughput. Here, we presented a microfluidic device capable of modulating membrane permeability through oscillating three-dimensional array of microbubbles. Simulations were performed to analyze the effective range of action of the oscillating microbubbles to obtain the optimal microchannel size. Utilizing a high-precision light curing 3D printer to fabricate uniformly sized microstructures in a one-step on both the side walls and the top surface for the generation of microbubbles. These microbubbles oscillated with nearly identical amplitudes and frequencies, ensuring efficient and stable sonoporation within the system. Cells were captured and trapped on the bubble surface by the acoustic streaming and secondary acoustic radiation forces induced by the oscillating microbubbles. At a driving voltage of 30 Vpp, the sonoporation efficiency of cells reached 93.9% ± 2.4%

    Applying slicing in an extended visual C++ environment

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    In recent years, a large amount of software has been developed. The need for maintaining and improving software systems has risen dramatically. How to reuse software becomes a very important problem. However, by using the existing technologies, it is difficult to identify the section of codes that implement functionality to help programmers in maintaining or reusing existing systems. To address this problem, Tan [22] proposed a novel representation, Data Flow Net, which can directly trace the functionalities to implementation artifacts.Master of Science (Communication and Network Systems

    Comparative Study on Microstructure and Properties of Electroless Ni - P and Ni - W - P Coatings

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    In order to better understand the advantages and disadvantages of electroless Ni - P and Ni - W - P coatings,X - ray diffractometer, optical microscope , electrochemical station, Vickers hardness tester and other test and analysis methods were used for the comparative study on the microstructure, adhesion, hardness and the corrosion resistance in particular working conditions of electroless Ni - P and Ni - W - P coatings in as - plated and heat - treated statuses. Results showed that the adhesion of two coatings with the substrate was good and both coatings had uniform thickness. The coatings showed well packed homogenous cells on their surfaces with a certain directionality and low porosity. The Ni - W - P coating started to crystallize at a lower heat treatment temperature than Ni - P coating. Besides, the Ni - W - P coating presented better ductility than Ni - P coating when the hardness of the coatings was higher than 800 HV3N. Meanwhile, the Ni - W - P coating had better anticorrosion property under certain corrosive service conditions

    Comprehensive single-cell transcriptomic and proteomic analysis reveals NK cell exhaustion and unique tumor cell evolutionary trajectory in non-keratinizing nasopharyngeal carcinoma

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    Abstract Background Nonkeratinizing nasopharyngeal carcinoma (NK-NPC) has a strong association with Epstein-Barr virus (EBV) infection. The role of NK cells and the tumor cell evolutionary trajectory in NK-NPC remain unclear. In this study, we aim to investigate the function of NK cell and the evolutionary trajectory of tumor cells in NK-NPC by single-cell transcriptomic analysis, proteomics and immunohistochemistry. Methods NK-NPC (n = 3) and normal nasopharyngeal mucosa cases (n = 3) were collected for proteomic analysis. Single-cell transcriptomic data of NK-NPC (n = 10) and nasopharyngeal lymphatic hyperplasia (NLH, n = 3) were obtained from Gene Expression Omnibus (GSE162025 and GSE150825). Quality control, dimension reduction and clustering were based on Seurat software (v4.0.2) process and batch effects were removed by harmony (v0.1.1) software. Normal cells of nasopharyngeal mucosa and tumor cells of NK-NPC were identified using copykat software (v1.0.8). Cell-cell interactions were explored using CellChat software (v1.4.0). Tumor cell evolutionary trajectory analysis was performed using SCORPIUS software (v1.0.8). Protein and gene function enrichment analyses were performed using clusterProfiler software (v4.2.2). Results A total of 161 differentially expressed proteins were obtained between NK-NPC (n = 3) and normal nasopharyngeal mucosa (n = 3) by proteomics (log2 fold change > 0.5 and P value < 0.05). Most of proteins associated with the nature killer cell mediated cytotoxicity pathway were downregulated in the NK-NPC group. In single cell transcriptomics, we identified three NK cell subsets (NK1-3), among which NK cell exhaustion was identified in the NK3 subset with high ZNF683 expression (a signature of tissue-resident NK cell) in NK-NPC. We demonstrated the presence of this ZNF683 + NK cell subset in NK-NPC but not in NLH. We also performed immunohistochemical experiments with TIGIT and LAG3 to confirm NK cell exhaustion in NK-NPC. Moreover, the trajectory analysis revealed that the evolutionary trajectory of NK-NPC tumor cells was associated with the status of EBV infection (active or latent). The analysis of cell-cell interactions uncovered a complex network of cellular interactions in NK-NPC. Conclusions This study revealed that the NK cell exhaustion might be induced by upregulation of inhibitory receptors on the surface of NK cells in NK-NPC. Treatments for the reversal of NK cell exhaustion may be a promising strategy for NK-NPC. Meanwhile, we identified a unique evolutionary trajectory of tumor cells with active status of EBV-infection in NK-NPC for the first time. Our study may provide new immunotherapeutic targets and new sight of evolutionary trajectory involving tumor genesis, development and metastasis in NK-NPC

    High water uptake ability was associated with root aerenchyma formation in rice: Evidence from local ammonium supply under osmotic stress conditions

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    Root water uptake is strongly influenced by the morphology and anatomical structure of roots, which are regulated by nitrogen forms and environmental stimuli. To further illustrate the roles of different nitrogen forms on root water uptake under osmotic stress, a split-root system was supplied with different nitrogen forms and osmotic stress simulated by adding 10% (w/v) polyethylene glycol (PEG, 6000). The local effects of nitrogen form and osmotic stress on root morphology, anatomical structure, root lignin content, and water uptake rate were investigated. Under osmotic stress conditions, ammonium markedly promoted the formation and elongation of the lateral root, whereas a significant decrease in numbers of lateral roots was observed under local nitrate supply. Under nitrate supply in split-root systems, osmotic stress significantly promoted root cell death and more aerenchyma formation, as well as accelerated the lignification of the root. However, osmotic stress had no negative effect on the root anatomical structure under ammonium supply. The root water uptake rate was significantly higher in split-root supplied with ammonium than nitrate under osmotic stress conditions. In conclusion, the high water uptake ability in local ammonium supply was associated with the more lateral roots development and the lower cell death, aerenchyma formation and lignification under osmotic stress

    FucP promotes the pathogenicity of Edwardsiella piscicida to infect zebrafish

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    Edwardsiella piscicida (E. piscicida) is an important zoonotic pathogen that mostly infects fish by colonizing the intestine. Fucose within the intestine could regulate the pathogenicity of some intestinal pathogens. Here we identified the function of fucose permease in E. piscicida and its physiological influence. The results showed that E. piscicida grew faster in the presence of l-fucose. The fucose permease gene fucP mutant strain ΔfucP significantly decreased penetration and motility in mucin compared with the wild-type strain. The gene expression levels of esaB, esaD, esaL and esaK in ΔfucP had significantly downregulated when compared with the wild-type strain. Most importantly, the survival rate of zebrafish after being infected with ΔfucP was significantly higher than those of the wild type. In a word, fucose promoted the growth and motility of E. piscicida and the fucP gene mutant decreased the pathogenicity of E. piscicida in zebrafish

    Preparation of Monoclinic Pyrrhotite by Thermal Decomposition of Jarosite Residues and Its Heavy Metal Removal Performance

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    Jarosite residues produced by zinc hydrometallurgical processing are hazardous solid wastes. In this study, monoclinic pyrrhotite (M-Po) was prepared by the pyrolysis of jarosite residues in H2S atmosphere. The influence of gas speed, reaction temperature, and time was considered. The mineral phase, microstructure, and elemental valence of the solids before and after pyrolysis were analyzed using X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy, respectively. The performances of the prepared M-Po on the removal of Zn and Pb from aqueous solution were evaluated. The results show M-Po to be the sole product at the reaction temperatures of 550 to 575 °C. Most of the M-Po particles are at the nanometer scale and display xenomorphic morphology. The phase evolution process during pyrolysis is suggested as jarosite → hematite/magnetite → pyrite → pyrite+M-Po → M-Po+hexagonal pyrrhotite (H-Po) → H-Po. The formation rate, crystallinity, and surface microtexture of M-Po are controlled by reaction temperature and time. Incomplete sulfidation may produce coarse particles with core–shell (where the core is oxide and the shell is sulfide) and triple-layer (where the core is sulfate, the interlayer is oxide, and the shell is sulfide) structures. M-Po produced at 575 °C exhibits an excellent heavy metal removal ability, which has adsorption capacities of 25 mg/g for Zn and 100 mg/g for Pb at 25 °C and pH ranges from 5 to 6. This study indicates that high-temperature sulfidation is a novel and efficient method for the treatment and utilization of jarosite residues

    Combined utility of Ki-67 index and tumor grade to stratify patients with pancreatic ductal adenocarcinoma who underwent upfront surgery

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    Abstract Objective To investigate the prognostic prediction of a new indicator, combined by tumor grade and Ki-67, in patients with resected pancreatic ductal adenocarcinoma (PDAC). Methods Data were retrospectively collected from consecutive patients who underwent primary resection of pancreas from December 2012 to December 2017. Tumor grade and Ki-67 were reviewed from routine pathological reports. G-Ki67 was classified as three categories as I (G1/2 and Ki-67 < 40%), II (G1/2 and Ki-67 ≥ 40%), and III(G3/4 and all Ki-67). Results Cox regression analyses revealed that tumor stage (II vs. I: hazard ratio (HR), 3.781; 95% confidence index (CI), 2.844–5.025; P < 0.001; III vs. I: HR, 7.476; 95% CI, 5.481–10.20; P < 0.001) and G-Ki67 (II vs. I: HR, 1.299; 95% CI, 1.038–1.624; P = 0.022; III vs. I: HR, 1.942; 95% CI, 1.477–2.554; P < 0.001) were independent prognostic factors in the developing cohort. The result was rectified in the validation cohort. In subgroups analysis, G-Ki67 (II vs. I: HR, 1.866 ; 95% CI, 1.045–3.334; P = 0.035; III vs. I: HR, 2.333 ; 95% CI, 1.156–4.705; P = 0.018) also had a high differentiation for survival prediction. Conclusion Our findings indicate that three-categories of G-Ki67 in resectable PDAC according to the routine pathological descriptions provided additional prognostic information complementary to the TNM staging system
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