In-Situ Monitoring of Reciprocal Charge Transfer and Losses in Graphene-Silicon CCD Pixels.

Charge-coupled devices (CCD) allow imaging by photodetection, charge integration, and serial transfer of the stored charge packets from multiple pixels to the readout node. The functionality of CCD can be extended to the non-destructive and in-situ readout of the integrated charges by replacing metallic electrodes with graphene in the metal-oxide-semiconductors (MOS) structure of a CCD pixel. The electrostatic capacitive coupling of graphene with the substrate allows the Fermi level tuning that reflects the integrated charge density in the depletion well. This work demonstrates the in-situ monitoring of the serial charge transfer and interpixel transfer losses in a reciprocating manner between two adjacent Gr-Si CCD pixels by benefitting the electrostatic and gate-to-gate couplings. We achieved the maximum charge transfer efficiency (CTE) of 92.4%, which is mainly decided by the inter-pixel distance, phase clock amplitudes, switching slopes, and density of surface defects. The discussion on overcoming transfer losses and improving CTE by realizing a graphene-electron multiplication CCD is also presented. The proof of the concept of the in-situ readout of the out-of-plane avalanche in a single Gr-Si CCD pixel is also demonstrated, which can amplify the photo packet in a pre-transfer manner.

Antibiotic resistance of Helicobacter pylori isolated from patients in Nanjing, China: A cross-section study from 2018 to 2021.

The increasing antibiotic resistance of Helicobacter pylori infection is a globally urging problem. To investigate the H. pylori resistance situation in Nanjing, China, we enrolled patients in Nanjing First Hospital from January 2018 to May 2021. H. pylori strains were isolated from patients who had at least one positive 13C-urea breath or rapid urease result. Subsequently, we performed antibiotic susceptibility tests on the isolated strains to clarithromycin, metronidazole, levofloxacin, amoxicillin, furazolidone and tetracycline. ARMS-PCR was conducted to determine H. pylori clarithromycin resistance gene mutation. Our results demonstrated that the primary resistance rates of metronidazole, clarithromycin, levofloxacin, amoxicillin, furazolidone and tetracycline were 67.19% (1417/2109), 35.99% (759/2109), 24.23% (511/2109), 0.76% (16/2109), 0.28% (6/2109) and 0.09% (2/2109), respectively. The resistance rates of metronidazole, clarithromycin and levofloxacin elevated significantly after treatment and the three antibiotics composed the majority of multi-resistance patterns. However, the resistance rates of amoxicillin, furazolidone and tetracycline were still in low levels after treatment. ARMS-PCR showed a rather good consistency with antibiotic susceptibility test in detecting clarithromycin resistance, with a kappa value of 0.79. Overall, this study revealed the latest complex situation of antibiotic resistance of H. pylori infection in Nanjing and offered suggestions on clinical medication for curing H. pylori.

Construction and Validation of a Novel Pyroptosis-Related Gene Signature to Predict the Prognosis of Uveal Melanoma.

Uveal melanoma is the most common primary intraocular tumor with a poor prognosis. Currently, treatment for UVM is limited, and the development of drug resistance and tumor recurrence are common. Therefore, it is important to identify new prognostic biomarkers of UVM and explore their role in the tumor microenvironment. Pyroptosis is a way of cell programmed death, and related research is in full throttle. However, the role of pyroptosis in UVM is unclear. In this study, we constructed the prognosis model of pyroptosis-related genes of UVM. This model can accurately guide the prognosis of UVM, and different groups differ in immune infiltration. We further verified our results in cell experiments. To some extent, our study can provide new ideas for the diagnosis and treatment of UVM.

Effects of Graphene Nanoplates on the Mechanical Behavior and Strengthening Mechanism of 7075Al Alloy.

7075Al alloy is the preferred material for lightweight automotive applications, but the existing problem is that it is difficult to combine high strength and high toughness. This paper presents our research aimed at obtaining high strength and high toughness materials by adding a nano-phase to realize microstructure refinement. Graphene nanoplates (GNP)/7075Al composites and 7075Al alloy were prepared by a stirring casting method in the present study. In comparison to 7075Al, the tensile strength of GNP/7075Al composites was increased from 572 MPa to 632 MPa while maintaining good uniform elongation of 8% to 10%. The increased strength behavior of GNP/7075Al composites while maintaining the plasticity is discussed in terms of grain refinement and dislocation evolution by analyzing the composite microstructure and quantitatively analyzing the contributions of grain boundary strengthening, solid solution strengthening, precipitation strengthening and dislocation strengthening. GNP's strengthening of GNP/7075Al composites is mainly attributed to the refinement of grain size and the increase of dislocation density.