A device-level characterization approach to quantify the impacts of different random variation sources in FinFET technology

A simple device-level characterization approach to quantitatively evaluate the impacts of different random variation sources in FinFETs is proposed. The impacts of random dopant fluctuation are negligible for FinFETs with lightly doped channel, leaving metal gate granularity and line-edge roughness as the two major random variation sources. The variations of Vth induced by these two major categories are theoretically decomposed based on the distinction in physical mechanisms and their influences on different electrical characteristics. The effectiveness of the proposed method is confirmed through both TCAD simulations and experimental results. This letter can provide helpful guidelines for variation-aware technology development

Polarization description of successive ferroelectric switching in hafnia

Intertwined ionic conduction and ferroelectric (FE) switching in HfO2 lead to extensive focuses. To describe its fundamental phenomena, we present a free-energy model describing the potential of ferroelectrics with successive FE switching paths, and extend the domain model of ionic conduction to ferroelectric domains. Associate theoretical analyses and first-principles calculations suggest a nesting-domain pattern with opposite piezoelectric loops during the nucleation-and-growth process in displacive FE-HfO2. A collective oxygen ion conduction mechanism is also proposed with a field-dependent ionic conductivity following the Merz's law. We conclude that the ionic conductibility is concomitant with the ferroelectricity in HfO2, and it may provide a new venue for pursuing low temperature fast oxide-ion conductors and artificial synapses.Comment: 26 page

Ultrafast Switching from the Charge Density Wave Phase to a Metastable Metallic State in 1T-TiSe2_2

The ultrafast electronic structures of the charge density wave material 1T-TiSe$_2$ were investigated by high-resolution time- and angle-resolved photoemission spectroscopy. We found that the quasiparticle populations drove ultrafast electronic phase transitions in 1T-TiSe$_2$ within 100 fs after photoexcitation, and a metastable metallic state, which was significantly different from the equilibrium normal phase, was evidenced far below the charge density wave transition temperature. Detailed time- and pump-fluence-dependent experiments revealed that the photoinduced metastable metallic state was a result of the halted motion of the atoms through the coherent electron-phonon coupling process, and the lifetime of this state was prolonged to picoseconds with the highest pump fluence used in this study. Ultrafast electronic dynamics were well captured by the time-dependent Ginzburg-Landau model. Our work demonstrates a mechanism for realizing novel electronic states by photoinducing coherent motion of atoms in the lattice.Comment: 13 Pages, 10 figure

Investigation on the amplitude of random telegraph noise (RTN) in nanoscale MOSFETs: Scaling limit of “Hole in the inversion layer” model

In this paper, the widely adopted “hole in the inversion layer” (HIL) model for predicting the amplitude of random telegraph noise (RTN) in nanoscale MOSFETs, is theoretically revisited with focusing on its scaling limit and validation range. It is found that this simple physical model fail to apply on ultra-scaled devices with L<;20nm and/or W<;10nm, due to the non-negligible impact from source/drain and the failure of assumed equivalence to resistor network in ultra-scaled devices. This work provides a deeper understanding to this model and is helpful for accurate prediction of RTN amplitude in nanoscale devices and circuits

Picturing Electron Capture to the Continuum in the Transfer Ionization of Intermediate-Energy He²⁺ Collisions with Argon

Electron emission occurring in transfer ionization for He2+ collisions with argon has been investigated using cold target recoil ion momentum spectroscopy. The double differential cross sections for electron capture to the continuum of the projectile (cusp-shaped electrons) are presented for collision energies from 17.5 to 75 keV/u. For an energy of 30 keV/u, we find a maximum in the experimental ratio of the cusp-shaped electron yield to the total electron yield. This result is explained in terms of the velocity matching between the projectile ion and the electron initially bound to the target. One of the important issues for double electron transitions is the role of electron-electron correlation. If this correlation is weak, then the transfer-ionization process can be viewed as two separate sequential processes. If this correlation is strong, then the transfer-ionization process would happen simultaneously and not sequentially. Our experimental and theoretical results indicate that correlation is weak and that the first step is target ionization followed by charge capture

Clinical distribution of carbapenem genotypes and resistance to ceftazidime-avibactam in Enterobacteriaceae bacteria

IntroductionBacterial resistance is a major threat to public health worldwide. To gain an understanding of the clinical infection distribution, drug resistance information, and genotype of CRE in Dongguan, China, as well as the resistance of relevant genotypes to CAZ-AVI, this research aims to improve drug resistance monitoring information in Dongguan and provide a reliable basis for the clinical control and treatment of CRE infection.MethodsVITEK-2 Compact automatic analyzer was utilized to identify 516 strains of CRE collected from January 2017 to June 2023. To determine drug sensitivity, the K-B method, E-test, and MIC methods were used. From June 2022 to June 2023, 80 CRE strains were selected, and GeneXpert Carba-R was used to detect and identify the genotype of the carbapenemase present in the collected CRE strains. An in-depth analysis was conducted on the CAZ-AVI in vitro drug sensitivity activity of various genotypes of CRE, and the results were statistically evaluated using SPSS 23.0 and WHONET 5.6 software.ResultsThis study identified 516 CRE strains, with the majority (70.16%) being K.pneumoniae, followed by E.coli (18.99%). Respiratory specimens had highest detection rate with 53.77% identified, whereas urine specimens had the second highest detection rate with 17.99%. From June 2022 to June 2023, 95% of the strains tested using the CRE GeneXpert Carba-R assay possessed carbapenemase genes, of which 32.5% were blaNDM strains and 61.25% blaKPC strains. The results showed that CRE strains containing blaKPC had a significantly higher rate of resistance to amikacin, cefepime, and aztreonam than those harboring blaNDM.ConclusionsThe CRE strains isolated from Dongguan region demonstrated a high resistance rate to various antibiotics used in clinical practice but a low resistance rate to tigecycline. These strains produce Class A serine carbapenemases and Class B metals β-lactamases, with the majority of them carrying blaNDM and blaKPC. Notably, CRE strains with blaKPC and blaNDM had significantly lower resistance rates to tigecycline. CAZ-AVI showed a good sensitivity rate with no resistance to CRE strains carrying blaKPC. Therefore, CAZ-AVI and tigecycline should be used as a guide for rational use of antibiotics in clinical practice to effectively treat CRE

Refining the accuracy of validated target identification through coding variant fine-mapping in type 2 diabetes.

We aggregated coding variant data for 81,412 type 2 diabetes cases and 370,832 controls of diverse ancestry, identifying 40 coding variant association signals (P < 2.2 × 10-7); of these, 16 map outside known risk-associated loci. We make two important observations. First, only five of these signals are driven by low-frequency variants: even for these, effect sizes are modest (odds ratio ≤1.29). Second, when we used large-scale genome-wide association data to fine-map the associated variants in their regional context, accounting for the global enrichment of complex trait associations in coding sequence, compelling evidence for coding variant causality was obtained for only 16 signals. At 13 others, the associated coding variants clearly represent 'false leads' with potential to generate erroneous mechanistic inference. Coding variant associations offer a direct route to biological insight for complex diseases and identification of validated therapeutic targets; however, appropriate mechanistic inference requires careful specification of their causal contribution to disease predisposition

The trans-ancestral genomic architecture of glycemic traits

Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 x 10(-8)), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution. A trans-ancestry meta-analysis of GWAS of glycemic traits in up to 281,416 individuals identifies 99 novel loci, of which one quarter was found due to the multi-ancestry approach, which also improves fine-mapping of credible variant sets.Peer reviewe

Implicating genes, pleiotropy, and sexual dimorphism at blood lipid loci through multi-ancestry meta-analysis

Publisher Copyright: © 2022, The Author(s).Background: Genetic variants within nearly 1000 loci are known to contribute to modulation of blood lipid levels. However, the biological pathways underlying these associations are frequently unknown, limiting understanding of these findings and hindering downstream translational efforts such as drug target discovery. Results: To expand our understanding of the underlying biological pathways and mechanisms controlling blood lipid levels, we leverage a large multi-ancestry meta-analysis (N = 1,654,960) of blood lipids to prioritize putative causal genes for 2286 lipid associations using six gene prediction approaches. Using phenome-wide association (PheWAS) scans, we identify relationships of genetically predicted lipid levels to other diseases and conditions. We confirm known pleiotropic associations with cardiovascular phenotypes and determine novel associations, notably with cholelithiasis risk. We perform sex-stratified GWAS meta-analysis of lipid levels and show that 3–5% of autosomal lipid-associated loci demonstrate sex-biased effects. Finally, we report 21 novel lipid loci identified on the X chromosome. Many of the sex-biased autosomal and X chromosome lipid loci show pleiotropic associations with sex hormones, emphasizing the role of hormone regulation in lipid metabolism. Conclusions: Taken together, our findings provide insights into the biological mechanisms through which associated variants lead to altered lipid levels and potentially cardiovascular disease risk.Peer reviewe