RESUMEN
The metal-semiconductor interface fabricated by conventional methods often suffers from contamination, degrading transport performance. Herein, we propose a one-pot chemical vapor deposition (CVD) process to create a two-dimensional (2D) MoO2-MoSe2 heterostructure by growing MoO2 seeds under a hydrogen environment, followed by depositing MoSe2 on the surface and periphery. The ultraclean interface is verified by cross-sectional scanning transmission electron microscopy and photoluminescence. Along with the high work function of semimetallic MoO2 (Ef = -5.6 eV), a high-rectification Schottky diode is fabricated based on this heterostructure. Furthermore, the Schottky diode exhibits an excellent photovoltaic effect with a high open-circuit voltage of 0.26 eV and ultrafast photoresponse, owing to the naturally formed metal-semiconductor contact with suppressed pinning effect. Our method paves the way for the fabrication of an ultraclean 2D metal-semiconductor interface, without defects or contamination, offering promising prospects for future nanoelectronics.
RESUMEN
Scalable micro graphene Hall sensors (µGHSs) hold tremendous potential for highly sensitive and label-free biomagnetic sensing in physiological solutions. To enhance the performance of these devices, it is crucial to optimize frequency-dependent flicker noise to reduce the limit of detection (LOD), but it remains a great challenge due to the large contact resistance at the graphene-metal contact. Here we present a surface modification strategy employing persistent carbene on gold electrodes to reduce the contact resistivity by a factor of 25, greatly diminishing µGHS flicker noise by a factor of 1000 to 3.13 × 10-14 V2/Hz while simultaneously lowering the magnetic LOD SB1/2 to 1440 nT/Hz1/2 at 1 kHz under a 100 µA bias current. To the best of our knowledge, this represents the lowest SB1/2 reported for scalable µGHSs fabricated through wafer-scale photolithography. The reduction in contact noise is attributed to the π-π stacking interaction between the graphene and the benzene rings of persistent carbene, as well as the decrease in the work function of gold as confirmed by Kelvin Probe Force Microscopy. By incorporating a microcoil into the µGHS, we have demonstrated the real-time detection of superparamagnetic nanoparticles (SNPs), achieving a remarkable LOD of â¼528 µg/L. This advancement holds great potential for the label-free detection of magnetic biomarkers, e.g., ferritin, for the early diagnosis of diseases associated with iron overload, such as hereditary hemochromatosis (HHC).
RESUMEN
PURPOSE: Catheter displacement is a common complication of peritoneal dialysis. The aim of this study was to explore the correlation between catheter morphology and displacement by analyzing CT data, providing a scientific basis for optimizing catheter morphology within abdominal wall layers. METHODS: We retrospectively analyzed the clinical data of 94 patients. The parameters for analyzing catheter morphology were defined based on six key points identified from CT images. The covariates considered in the analysis included demographics, primary disease, body size, peritoneal dialysis method, and total weekly urea clearance index. RESULTS: During a mean follow-up period of 1056 ± 480 days, only the angle of the intramuscular part (IM angle) of the catheter significantly correlated with the time to first catheter displacement according to the multivariate analysis (hazard ratio [HR]: 1.039, 95% confidence interval [CI] 1.02-1.058, p < 0.01). When the cut-off value of IM angle was 39.4 ∘ , the area under receiver-operating characteristic (ROC) curve for predicting catheter displacement was 0.791 (95% CI 0.701-0.881, p < 0.01), with a sensitivity and specificity of 82.9% and 66.0%, respectively. Kaplan-Meier survival curves showed that the catheter survival rate was significantly higher in the group with an IM angle < 39.4 ∘ than in the group with an IM angle > 39.4 ∘ (log-rank χ 2 =19.479, p < 0.01). None of the catheter morphology parameters were significantly correlated with technique survival in the multivariate analysis. CONCLUSION: There is a correlation between catheter morphology and catheter displacement. An IM angle > 39.4 ∘ is an independent risk factor for catheter displacement, while the position and angle of the subcutaneous part are not correlated with catheter displacement.