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The use of AgNO3-polyvinyl alcohol (PVA) ink and oxygen plasma to form conductive coatings on plastic substrates was studied. It was found that oxygen plasma can decompose silver complexes to form metallic silver without high-temperature heating. The AgNO3-PVA ratio and plasma parameters (time, power) were optimized to obtain uniform conductive coatings. The morphology and electrical characteristics of the coatings were evaluated. Composite coatings with high reflectivity and good adhesion were prepared with a resistivity of 1.66 × 10−6 Ω·m using MOD inks with a silver ion mass fraction of 5%, after 300 W plasma treatment of the PET substrate for 2 min (the chamber temperature was 37.3 °C). These results demonstrate the potential feasibility of silver MOD inks and oxygen plasma treatment for the production of silver connectors, electromagnetic shielding films, and antimicrobial coatings on low-cost plastic substrates. [ABSTRACT FROM AUTHOR]

Although hydrazine (N2H4) is a versatile chemical used in many applications, it is toxic, and its leakage may pose a threat to both human health and environments. Consequently, the monitoring of N2H4 is significant. This study reports a one-step synthesis for coumarin-based ratiometric fluorescent probe (FP) CHAC, with acetyl as the recognition group. Selected deprotection of the acetyl group via N2H4 released the coumarin fluorophore, which recovered the intramolecular charge transfer process, which caused a prominent fluorescent, ratiometric response. CHAC demonstrated the advantages of high selectivity, a strong capacity for anti-interference, a low limit of detection (LOD) (0.16 μM), a large linear detection range (0–500 μM), and a wide effective pH interval (6–12) in N2H4 detection. Furthermore, the probe enabled quantitative N2H4 verifications in environmental water specimens in addition to qualitative detection of N2H4 in various soils and of gaseous N2H4. Finally, the probe ratiometrically monitored N2H4 in living cells having low cytotoxicity. [ABSTRACT FROM AUTHOR]

A correction algorithm based on analyzing the steam condensation locations is proposed to address the problem of large errors when calculating the heat transfer of the air-cooling condenser (ACC) in Fluent. By building a detailed geometric model of the ACC and using radiator boundary conditions to simplify the heat-sinking tube bundle, Fluent software was used to calculate the heat transfer of the ACC under four winter operating conditions, and then, the calculation results were further corrected by applying the correction algorithm. The results show that after using the correction algorithm, the errors between calculation results and experiment data are reduced from 4.20~36.98% to 0.01~1.79%. When the electric load of the air-cooling generator set or the ambient temperature was low, the condensation velocity increased, for which there would be a local steam-free area in the heat-sinking tube bundle of the ACC, leading to large errors when using the radiator model. At this point, the correction algorithm based on the analysis of steam condensation position can serve to improve the degree of accuracy. Meanwhile, this correction algorithm can be further expanded to use in the simulating calculation of an indirect air-cooling generator set, and it is able to correct the heat transfer calculation result of the air-cooling tower by analyzing the heat transfer condition of circulating water in the heat-sinking tube bundle, so that reliable data can be provided to guide the anti-freezing of the indirect air-cooling generator set. [ABSTRACT FROM AUTHOR]

Electrodeless plasmoid electromagnetic propulsion was recently proposed for robotic and crewed space missions. This electrodeless construction has the potential to solve the existing limitations, such as duration and low efficiency. The rotating magnetic field (RMF) excitation and Lorentz Force acceleration mechanism of the plasmoid has the advantage of producing a highly variable thrust and a discrete impulse. In this article, the plume performance of the proposed propulsion primer was presented for the first time and evaluated by varying the RMF input power, bias magnetic field, and flow rate, while the power of the preionization source and discharge propellant are held constant. The RMF excitation and Lorentz Force acceleration mechanism of the plasmoid were confirmed by the plume performance and discharge characteristics. The stable discharge in Ar, N2, and Xe demonstrated the potential application of this electrodeless technology in future multipropellant high-power propulsion applications. The phase angle of 90° in the RMF coil was essential for the higher performance of the plasma plume. The propulsion thrust and specific impulse were estimated to be 16.1 mN and 1600 N $\cdot $ s, respectively, at 1.2 kW from the initial test conducted using the Langmuir probe, assuming a complete penetration of RMF in the plasma. [ABSTRACT FROM AUTHOR]

We performed molecular dynamics simulations of the high voltage pulse explosion of single aluminum wires with the energy ratio of 0.6 in vacuum and studied the role of wire radial dimension. Simulation results show that large-diameter wires having a large material depth and a small specific surface can maintain a higher deposition energy density and effectively reduce the influence of the radial difference in thermodynamic parameters, leading to higher explosion velocity and a lower vaporization rate in the large-diameter wire. The most significant effect is that the larger diameter wire has a longer explosion development time. In addition, the propagation and reflection of the rarefaction waves in the wire result in two explosion regimes: the spinodal decomposition propagating inward from the surface and the cavitation boiling from the center to the surface. Increasing the diameter will increase the domination range of the spinodal decomposition mechanism. [ABSTRACT FROM AUTHOR]

This study aimed at discussing the laws of the design parameters of a radio frequency (RF) ion thruster that influence the thruster performance, guide the performance optimization-oriented design of the thruster, and realize the high-accuracy continuous adjustment of the thrust performance. The key influencing parameters of the thrust performance were analyzed by the numerical simulation method. The influencing laws of RF parameters on key plasma parameters, as well as the thermal characteristics of the thruster under the rated parameters, were explored. Moreover, a LRIT-30 RF ion thruster was developed and subjected to the performance adjustment test. The research results demonstrated that the simulation model can describe the plasma parameter distribution of the discharge chamber and the thermal distribution of key components. The 3 cm RF ion thruster performs well under 2 MHz operational frequency. The RF power and gas flow rate are the key influencing factors of beam extraction and are appropriate for the accurate adjustment of parameters. The wide-range adjustment of thrust (0.5–2.3 mN) and specific impulse (869–2564 s) can be realized when the screen-grid voltage, decelerating screen voltage, RF power, and gas flow rate are 1500 V, −200 V, 40–65 W, and 0.4–0.8 SCCM, respectively. The performance indices of the proposed RF ion thruster are close to the international advanced level. [ABSTRACT FROM AUTHOR]

To optimize thrust performance, the expression of space‐charge‐limited current for vacuum arc thruster is derived from Poisson's equation. The commonly used ring‐type and coaxial‐type vacuum arc thrusters are simplified to the equivalent current sheet in planar geometry and cylindrical capacitor, respectively, for this calculation. Both the spatial distribution and peak magnitude of space‐charge‐limited current are given explicitly, together with their dependences on gap distance, applied voltage, charge number, and ion mass. For typical experimental parameters of the vacuum arc thruster, it is shown that the maximum current density drops significantly when the gap distance becomes large and grows when the applied voltage increases; moreover, a cathode material of lower atomic weight yields a higher current density. The expressions of total current for these two types of vacuum arc thruster are also presented. This work, to our best knowledge, is the first application of space‐charge‐limited current to the vacuum arc thruster and practically very interesting for engineering design. [ABSTRACT FROM AUTHOR]

Large volume helicon plasma sources are of particular interest for large scale semiconductor processing, high power plasma propulsion and recently plasma-material interaction under fusion conditions. This work is devoted to studying the coupling of four typical RF antennas to helicon plasma with infinite length and diameter of 0.5 m, and exploring its frequency dependence in the range of 13.56-70 MHz for coupling optimization. It is found that loop antenna is more efficient than half helix, Boswell and Nagoya III antennas for power absorption; radially parabolic density profile overwhelms Gaussian density profile in terms of antenna coupling for low-density plasma, but the superiority reverses for high-density plasma. Increasing the driving frequency results in power absorption more near plasma edge, but the overall power absorption increases with frequency. Perpendicular stream plots of wave magnetic field, wave electric field and perturbed current are also presented. This work can serve as an important reference for the experimental design of large volume helicon plasma source with high RF power. [ABSTRACT FROM AUTHOR]

Most hepatocellular carcinomas (HCCs) are associated with hepatitis B virus infection (HBV) in China. Early detection of HCC can significantly improve prognosis but is not yet fully clinically feasible. This study aims to develop methods for detecting HCC and studying the carcinogenesis of HBV using plasma cell-free DNA (cfDNA) whole-genome sequencing (WGS) data. Low coverage WGS was performed for 452 participants, including healthy individuals, hepatitis B patients, cirrhosis patients, and HCC patients. Then the sequencing data were processed using various machine learning models based on cfDNA fragmentation profiles for cancer detection. Our best model achieved a sensitivity of 87.10% and a specificity of 88.37%, and it showed an increased sensitivity with higher BCLC stages of HCC. Overall, this study proves the potential of a non-invasive assay based on cfDNA fragmentation profiles for the detection and prognosis of HCC and provides preliminary data on the carcinogenic mechanism of HBV. • Each of four cohorts harbours unique cfDNA fragmentation profile, indicating potential biomarker for cancer early detection. • cfDNA fragmentation profiles vary between relapse and non-relapse groups of HCC patients. • HBV integration cause specific cfDNA epigenomic alterations to host genome, which can be eased after antiviral therapy. • cfDNA fragmentation profiles predict significant portion of hepatitis B and cirrhosis patient have early signs of HCC. [ABSTRACT FROM AUTHOR]

Liver cancer is a highly lethal malignancy. Despite considerable efforts made in recent years, the prognosis of patients with liver cancer remains poor. Curcuma zedoaria (known as Ezhu in Chinese) is widely prescribed in traditional Chinese medicine. Germacrone (GM) is a sesquiterpene constituent derived from the essential oil of Ezhu, and exerts anti-carcinogenic effects by inducing apoptosis in various cancer cells. The present study investigated the potential mechanism of GM in HepG2 cells. Cell Counting Kit-8, colony-formation and lactate dehydrogenase-release assays, as well as cell death assays using flow cytometry, were performed to evaluate HepG2 cell proliferation following GM treatment. HepG2 cells were transfected with caspase-3 small interfering RNA and then treated with GM. Caspase-3 expression levels were determined by reverse transcription-quantitative PCR and western blotting. The present study showed that GM inhibited the growth of HepG2 cells and induced the proteolytic cleavage of caspase 3, with concomitant cleavage of gasdermin E (GSDME), by markedly increasing the production of reactive oxygen species (ROS). This led to caspase 3-dependent cleavage of GSDME, thereby promoting pyroptosis in HepG2 cells. However, these changes were rescued by ROS scavengers, such as N-acetylcysteine. Furthermore, GM inhibited tumor growth by promoting the cleavage of caspase 3 and GSDME in HepG2 cell xenograft models. These results indicated that GM induced GSDME-dependent pyroptosis through caspase 3 activation, at least in part, by damaging the mitochondria and enhancing ROS production, thereby supporting the possible development of GM as a candidate for the prevention and treatment of liver cancer. [ABSTRACT FROM AUTHOR]

Circular RNAs (circRNAs) are differentially expressed in various cancer types. The present study aimed to investigate the expression and clinical implication of circRNAs in hepatocellular carcinoma (HCC) and to evaluate the potential of circRNAs as diagnostic biomarkers for HCC. CircRNA expression was profiled in 19 patients with HCC and 19 normal controls using ribosomal RNA-depleted RNAs. Differentially expressed circRNAs (DE-circRNAs) between HCC and controls were identified using CIRI2 and distinct circRNA expression signatures were screened. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes were used to predict the potential functions of these DE-circRNAs and the circRNA-miRNA-mRNA regulatory networks were then constructed. Several DE-circRNAs were selected and confirmed by RT-qPCR. A total of 40 DE-circRNAs (27 upregulated and 13 downregulated) were identified between patients with HCC and controls. Functional annotation indicated that these DE-circRNAs were involved in cellular components, molecular functions and cancer-associated pathways related to HCC. These included pathways in cancer, TNF signaling pathway, hepatitis B, hepatitis C and hepatocyte differentiation. The circRNA-miRNA-mRNA regulatory network was generated based on 11 candidate circRNAs. Receiver operating characteristic curve analysis indicated that Homo sapiens (hsa)_circ_0073239, hsa_circ_007090, hsa_circ_0008304, hsa_circ_0017586, hsa_circ_0000369 and hsa_circ_0001181 may serve as potential biomarkers for HCC. Results from Cell Counting Kit-8 assay suggested that small interfering RNA targeting hsa_circ_0001181 reduced the proliferation of HepG2 cells, which implicated it as a potential therapeutic target for HCC. Therefore, in the present study, the differential expression pattern and important role of circRNAs in HCC were determined. The present results highlight the diagnostic potential of circRNAs in HCC and provide novel insight into the development of and treatment approaches for HCC. [ABSTRACT FROM AUTHOR]

To demonstrate the mysterious and still controversial mechanism of high ionization efficiency during helicon discharges, this work focuses particularly on the role of second‐order radial density gradient (SRDG) in helicon power absorption, both analytical and numerical. It was found that the positive or negative sign of SRDG and radial location of vanishing SRDG determine the radial profile of power absorption remarkably. First, by measuring SRDG at two radial locations (near plasma core and edge) where power absorption usually peaks, and varying it as a function of free parameter, we see that: (a) the power absorption from the antenna to plasma increases for positive SRDG and decreases for negative SRDG when viewed in the same x‐coordinate direction of SRDG and (b) the power absorption is maximized near the position where this local SRDG vanishes, consistent with the theory of radially localized helicon mode (B. N. Breizman and A. V. Arefiev, Phys. Rev. Lett., 84:3863, 2000). Second, by choosing the whole radial profiles of typical plasma distribution that have zero‐crossing SRDG, we find that the power absorption redistributes significantly when the location of vanishing SRDG moves radially outwards, and specifically when the radial locations of maximum power absorption and vanishing SRDG move in the same direction near the plasma core but noticeably in the opposite direction near the plasma edge. These findings are very interesting for helicon plasma applications that require certain power distribution or heat flux configuration, for example, material processing, which can be controlled by adjusting the radial profile of SRDG, especially the zero‐crossing SRDG. [ABSTRACT FROM AUTHOR]

Although oral delivery of exenatide has significant advantages, its poor permeability through intestinal epithelial membranes and rapid digestion by pepsin and ereptase in the gastrointestinal tract make effective oral delivery of exenatide a formidable challenge. In this study, we constructed a zinc ion (Zn 2+ ) and exenatide complex functionalized nanoparticle (NP) oral delivery system to overcome the above-mentioned issue. Polyethylene glycol-poly(lactic-co-glycolic acid) (PEG-PLGA) was used as a drug carrier to escape enzymatic degradation in the gastrointestinal tract, and low molecular weight protamine (LMWP) was used as a functional group to increase penetration of NPs into the intestinal epithelium. The functionalized NPs exhibited significantly improved penetration across the intestinal epithelium, as shown by cell uptake and transmembrane transport experiments. Moreover, a significant hypoglycemic effect was observed in diabetic rats. The relative bioavailability of the orally administered functionalized NPs vs. subcutaneous injection was 7.44%, 29-fold that of the exenatide-Zn 2+ solution group. These findings indicate that our modification could effectively improve exenatide treatment. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to evaluate changes in subfoveal choroidal thickness after photodynamic therapy in patients with acute idiopathic central serous chorioretinopathy (ICSCR)., Methods: This was a retrospective observational study conducted in 63 participants. The primary outcome measure was subfoveal choroidal thickness at baseline and 3 days, one week, 4 weeks, and 12 weeks after photodynamic therapy. The secondary outcome measure was indocyanine green angiography at baseline and 4 weeks and 12 weeks after photodynamic therapy., Results: Four weeks after photodynamic therapy, 20 (64.51%) symptomatic eyes showed hypofluorescence corresponding to the area of photodynamic therapy irradiation at the posterior pole. The mean subfoveal choroidal thickness increased significantly from 422±132 μm at baseline to 478±163 μm at day 3 after treatment (P=0.022) and then decreased to 362±113 μm at week 4 (P<0.001) and 339±135 μm at week 12 (P<0.001)., Conclusion: The subfoveal choroid in patients with acute ICSCR is thicker than in the normal population, and in symptomatic eyes is significantly thicker than in fellow eyes. Photodynamic therapy using a one third dose of verteporfin may decrease choroidal vascular hyperpermeability and choroidal thickness in patients with acute ICSCR.