High-speed laser cladding technology can significantly improve the efficiency of coating preparation and effectively widen the application range of laser cladding. In this study, the Ni45 powders ...were deposited on steel substrate by traditional low speed laser cladding and high-speed laser cladding process, respectively. The cladding efficiency, surface forming, cross-sectional microstructure, microhardness, wear and corrosion resistance properties of the traditional and high-speed laser cladded Ni45 alloy coatings were compared. It can be seen that the thickness of the high-speed laser cladding coating was much thinner than that of the traditional laser cladding coating. Compared with traditional laser cladding, high-speed laser cladding could achieve a cladding speed of 76.86 m/min and a cladding efficiency of 156.79 cm2/min. The microstructure of the two kinds of coatings shows the same growth law, but the microstructure in high-speed laser cladding was smaller and denser, and the columnar crystal interval was narrower, only about 6 μm. It is found that the cooling rate of the traditional laser cladding coating was smaller than that of the high-speed laser cladding, and as the cladding speed increased, the cooling rate became higher and higher. The cross-section microhardness of the traditional laser cladding coating was relatively uniform of 337 HV0.2, while the microhardness of high-speed laser cladding surface increased to about 543 HV0.2. In addition, the wear and corrosion resistance of high-speed laser cladded coatings were better than that of traditional laser cladded coatings. As the cladding speed increased, the wear and corrosion resistance of the cladded coatings became better.
•High-speed laser cladding coating had low roughness and thin coating.•The cooling rate increased exponentially with a decrease of secondary dendrite arm.•The wear and corrosion resistance increased with the increase of cladding speed.•The microstructure was refined continuously with the increase of cladding speed.
A simple, one-step facile route for preparation of water soluble and fluorescent Cu nanoclusters (NCs) stabilized by tannic acid (TA) is described. The as-prepared TA capped Cu NCs (TA-Cu NCs) are ...characterized by UV–vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, luminescence, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The TA-Cu NCs show luminescence properties having excitation and emission maxima at 360nm and 430nm, respectively, with a quantum yield of about 14%. The TA-Cu NCs are very stable even in 0.3M NaCl, and their luminescent properties show pH independent. The fluorescence (FL) of Cu NCs is strongly quenched by Fe3+ through an electron transfer mechanism, but not by other metal ions. Furthermore, the FL of the TA-Cu NCs shows no changes with the addition of Fe2+ or H2O2 individually. On this basis, a facile chemosensor was developed for rapid, reliable, sensitive, and selective sensing of Fe3+ ions with detection limit as low as 10nM and a dynamic range from 10nM to 10μM. The proposed sensor was successfully used for the determination of iron contents in serum samples. Importantly, the Cu NCs-based FL probe showed long-term stability, good biocompatibility and very low cytotoxicity. It was successfully used for imaging ferric ions in living cells, suggesting the potential application of Cu NCs fluorescent probe in clinical analysis and cell imaging.
•A simple and facile strategy for the synthesis of fluorescent Cu NCs was developed.•The obtained Cu NCs were water soluble, stable and highly quantum efficient.•The Cu NCs were used as the favorable probe for Fe3+ ion over other common cations.•The Cu NCs show low cytotoxicity and are suitable for cell imaging.•The obtained Cu NCs can be used for imaging ferric ions in living cells.
Although substantial progress has been made in cancer biology and treatment, clinical outcomes of bladder carcinoma (BC) patients are still not satisfactory. The tumor microenvironment (TME) is a ...potential target. Here, by single-cell RNA sequencing on 8 BC tumor samples and 3 para tumor samples, we identify 19 different cell types in the BC microenvironment, indicating high intra-tumoral heterogeneity. We find that tumor cells down regulated MHC-II molecules, suggesting that the downregulated immunogenicity of cancer cells may contribute to the formation of an immunosuppressive microenvironment. We also find that monocytes undergo M2 polarization in the tumor region and differentiate. Furthermore, the LAMP3 + DC subgroup may be able to recruit regulatory T cells, potentially taking part in the formation of an immunosuppressive TME. Through correlation analysis using public datasets containing over 3000 BC samples, we identify a role for inflammatory cancer-associated fibroblasts (iCAFs) in tumor progression, which is significantly related to poor prognosis. Additionally, we characterize a regulatory network depending on iCAFs. These results could help elucidate the protumor mechanisms of iCAFs. Our results provide deep insight into cancer immunology and provide an essential resource for drug discovery in the future.
Chitosan stabilized silver nanoparticles (Ch-Ag NPs) were successfully synthesized by a one-step method and were found to possess intrinsic peroxidase-like activity, could catalytically oxidize ...substrates, such as TMB, and OPD, by H(2)O(2) to produce a typical colour reaction such as from colorless to blue for TMB and from colorless to red for OPD. Our results demonstrate that the Ch-Ag NPs exhibit higher thermal and pH durance than HRP, thus could be suitable in a wider range of harsh conditions. Results of electron paramagnetic resonance (ESR) suggest that the catalyse-mimic activity of the Ch-Ag nanostructures effectively catalyzed the decomposition of H(2)O(2) into ˙OH radicals. Based on this finding, a simple, sensitive and selective visual and colorimetric method with TMB as substrate has been designed for glucose detection when combined with glucose oxidase (GOx). This colorimetric method can be used for detection of glucose in biological samples with a detection limit as low as 100 nM and a dynamic range from 5.0 × 10(-6) to 2.0 × 10(-4) M.
Accumulating evidence supports that Sirtuin 6 (SIRT6) may play a vital role in the pathogenesis of spinal cord injury. The current study was designed to investigate the specific effects of SIRT6 on ...spinal cord injury (SCI). HE and Nissl staining were performed for pathological analysis in SCI rats. SIRT6 expression was detected by RT-qPCR. CCK8 assay was applied for the detection of cell viability of LPS-injured PC12 cells. TNF-a, IL-1β, IL-6, MCP-1 levels and ROS, MPO, SOD levels were assessed to evaluate inflammation and oxidative stress in spinal cord injury. Cell apoptosis were evaluated by morphological examination using AO/EB fluorescent staining methods and key proteins related to apoptosis were explored
via
western blot. HE staining revealed increased cavity involving the dorsal white matter and central gray matter, and Nissl staining discovered the loss of motor neurons in the ventral horn in SCI rats. SIRT6 had lower expression in SCI rats. Lipopolysaccharide (LPS) exposure induced cell apoptosis and reduced the expression of SIRT6. Mechanistically, we revealed that up-regulation of SIRT6 alleviated inflammation and oxidative stress and inhibited cell apoptosis in spinal cord injury. Together, our findings indicated that SIRT6 attenuated spinal cord injury by suppressing inflammation, oxidative stress, and cell apoptosis. This study demonstrates that SIRT6 may represent a protective effect against spinal cord injury.
The cool skin effect refers to the phenomenon where the surface skin temperature of the ocean is always slightly cooler than the temperature of the water directly underneath due to the ubiquitous ...cooling processes at the ocean surface, especially in the absence of solar radiation. The cool skin effect plays a critical role in the estimation of heat, momentum, and gas exchange between the air and the sea. However, the scarcity of observational data greatly hinders the accurate assessment of the cool skin effect. Here, the matchup data from the new generation geostationary satellite Himawari-8 and in situ sea surface temperature (SST) observations are used to evaluate the performance and dependence on the cool skin effect in the low/mid-latitude oceans. Results show that the intensity of the cool skin effect as revealed by Himawari-8 (−0.16 K) is found to be relatively weaker than previously published cool skin models based on in situ concurrent observations. A considerable amount of warm skin signals has been detected in the high-latitude oceans (e.g., Southern Ocean) under the circumstances of positive air–sea temperature difference and high wind, which may be the main cause of discrepancies with previous thoughts on the cool skin effect.
Clear-cell renal cell carcinoma (ccRCC) is the most common histological type of RCC. To investigate the intratumoral heterogeneity of ccRCC, we analyzed single-cell RNA-sequencing data and identified ...15 major cell types, along with 39 subgroups of cells derived from tumor or non-malignant tissues, and confirmed their presence by immunofluorescence staining in tissue chips. In this study, we verified that T cell exhaustion was the key factor responsible for the immunosuppressive property of ccRCC tissues, which was significantly related to poor prognosis. We also found that abnormal metabolic patterns occurred not only in cancer cells, but also in tumor-infiltrating stromal cells. Based on the fraction of each cell cluster detected by CIBERSORTx, 533 patients from The Cancer Genome Atlas (TCGA) KIRC dataset were divided into three groups. One group, which showed a lesser proportion of activated CD8+ cells and greater proportion of exhausted CD8+ cells, was associated with a poor prognosis. Hence, the blockade of immunosuppressive checkpoints, not only PD-1, but also LAG3, TIM-3, and other inhibitory checkpoints, could serve as a potential target for ccRCC immunotherapy. Our work will further the understanding of the heterogeneity among ccRCC tissues and provide novel strategies for treating ccRCC.
Display omitted
Via single-cell transcriptome analysis, we investigated the intra-tumoral heterogeneity of clear-cell renal cell carcinoma (ccRCC) and identified the composition inside tumor tissues. With a computational pipeline, we revealed the clinical significance of tumor-infiltrating cells and provided novel strategies for treating ccRCC.
The blood-brain barrier (BBB) tightly regulates the entry of solutes from blood into the brain and is disrupted in several neurological diseases. Using Organ-Chip technology, we created an entirely ...human BBB-Chip with induced pluripotent stem cell (iPSC)-derived brain microvascular endothelial-like cells (iBMECs), astrocytes, and neurons. The iBMECs formed a tight monolayer that expressed markers specific to brain vasculature. The BBB-Chip exhibited physiologically relevant transendothelial electrical resistance and accurately predicted blood-to-brain permeability of pharmacologics. Upon perfusing the vascular lumen with whole blood, the microengineered capillary wall protected neural cells from plasma-induced toxicity. Patient-derived iPSCs from individuals with neurological diseases predicted disease-specific lack of transporters and disruption of barrier integrity. By combining Organ-Chip technology and human iPSC-derived tissue, we have created a neurovascular unit that recapitulates complex BBB functions, provides a platform for modeling inheritable neurological disorders, and advances drug screening, as well as personalized medicine.
Display omitted
•iPSC and microfluidic technologies were combined to generate a human BBB-Chip•Flow-induced shear and co-cultures enhance barrier performance•The BBB-Chip exhibits physiologically relevant TEER and can predict CNS penetrance•Personalized BBB-Chips can detect interindividual variability in BBB performance
The blood-brain barrier (BBB) is a multicellular neurovascular unit that tightly regulates brain homeostasis and is disturbed in several neurological diseases. Combining patient-specific stem cells and microfluidic technologies, Vatine et al. have generated a personalized human BBB-Chip, which recapitulates the human BBB and can predict variability between individuals.
Time-delay exists widely in electric power systems, and is found to have significant effect on the performance of operation and control under certain conditions. It is shown that even a very small ...delay may destabilize the power system. Therefore, time-delay is of important concern and should be properly handled, especially in the wide-area measurement and control environment. However, only few results about the controller design for power system considering multiple time-delays are reported. In this paper, a multiple time-delayed power system model is constructed with power system stabilizer (PSS) considering time-delays. By using Lyapunov stability theory and linear matrix inequality (LMI) method, two H ∞ control schemes are developed for time-varying multiple delayed systems. The proposed controllers guarantee the closed-loop system asymptotic stable with H ∞ performance. A two-area four-machine power system and the New England 10-machine 39-bus system are employed to demonstrate the effectiveness of proposed methods. The simulation results verify that the designed controllers can improve the control performance significantly.
Single-cell sequencing technologies have noteworthily improved our understanding of the genetic map and molecular characteristics of bladder cancer (BC). Here we identify CD39 as a potential ...therapeutic target for BC via single-cell transcriptome analysis. In a subcutaneous tumor model and orthotopic bladder cancer model, inhibition of CD39 (CD39i) by sodium polyoxotungstate is able to limit the growth of BC and improve the overall survival of tumor-bearing mice. Via single cell RNA sequencing, we find that CD39i increase the intratumor NK cells, conventional type 1 dendritic cells (cDC1) and CD8 + T cells and decrease the Treg abundance. The antitumor effect and reprogramming of the tumor microenvironment are blockaded in both the NK cells depletion model and the cDC1-deficient Batf3
model. In addition, a significant synergistic effect is observed between CD39i and cisplatin, but the CD39i + anti-PD-L1 (or anti-PD1) strategy does not show any synergistic effects in the BC model. Our results confirm that CD39 is a potential target for the immune therapy of BC.
PDF
