Trends and hotspots of global ultra-processed food research(2010-2023):A scientometric study

Background:Recently,ultra-processed foods(UPFs)have attracted considerable attention,leading to numerous studies worldwide.Scientometrics is currently gaining popularity among scientific communities,offering advantage of providing critical references to scholars of specific fields.Methods:This scientometric study aimed to analyze trends and hotspots of UPF research using English articles or reviews related to UPFs retrieved from the Web of Science Core Collection on March 5,2023.Two independent researchers selected the identified records on titles,abstracts,and author’s keywords,and the data were analyzed using R-bibliometrix,CiteSpace,and VOSviewer.Results:A total of 1018 publications(901 articles and 117 reviews)published from 2010 to 2023 were included.The result showed a significant increase in UPF publications over the past decades.Brazil published the highest number of papers(n=473),with over half of the top 10 active institutions were located in Brazil.The University of São Paulo contributed the most publications(n=206)and the 10 most productive authors belonged to this institution,with Monteiro CA and Levy RB contributing the most publications.The main research foundations included the NOVA system,the definition of UPFs,the prevalence of UPFs,and the impact of UPFs on dietary quality and health status.The main research frontiers included topics such as“systematic review,”“NOVA food classification,”“COVID-19,”“diabetes,”“pregnancy,”“food addiction,”“warning labels,”“plant-based diet,”and“commercial determinants of health”.Conclusions:This study provided a comprehensive overview of development trends and research hotspots of global UPF studies.

Evaluation of the passivation effect and the first-principles calculation on surface termination of germanium detector

The point-contact high-purity germanium detector(HPGe)has the advantages of low background,low energy threshold,and high energy resolution and can be applied in the detection of rare-event physics.However,the performance of HPGe must be further improved to achieve superior energy resolution,low noise,and long-term reliability.In this study,we combine computational simulations and experimental comparisons to deeply understand the passivation mechanism of Ge.The surface passivation effect is calculated and inferred from the band structure and density of interface states,and further con-firmed by the minority carrier lifetime.The first-principles method based on the density functional theory was adopted to systematically study the lattice structure,band structure,and density of state(DOS)of four different systems:Ge–H,Ge–Ge-NH 2,Ge-OH,and Ge-SiO_(x).The electronic char-acteristics of the Ge(100)unit cell with different passi-vation groups and Si/O atomic ratios were compared.This shows that H,N,and O atoms can effectively reduce the surface DOS of the Ge atoms.The passivation effect of the SiO_(x) group varied with increasing O atoms and Si/O atomic ratios.Experimentally,SiO and SiO_(2) passivation films were fabricated by electron beam evaporation on a Ge substrate,and the valence state of Si and resistivity was measured to characterize the film.The minority carrier lifetime of Ge-SiO_(2) is 21.3 ls,which is approximately quadruple that of Ge-SiO.The passivation effect and mechanism are discussed in terms of hopping conduction and surface defect density.This study builds a relationship between the passivation effect and different termination groups,and provides technical support for the potential passivation layer,which can be applied in Ge detectors with ultralow energy thresholds and especially in HPGe for rare-event physics detection experiments in future.