Experimental Details of a Steep-Slope Ferroelectric InGaAs Tunnel-FET With High-Quality PZT and Modeling Insights in the Transient Polarization

The steep-slope ferroelectric tunnel-FET (SS-FeTFET), consisting of an InGaAs TFET with a sub-60 mV/dec subthreshold swing (SS) at room temperature and an externally connected high-quality single-crystalline PZT capacitor, displays improved SS compared to the standalone TFET. In this article, we describe the measurement procedure and measurement results of this SS-FeTFET in great detail. To quantitatively extract the ferroelectric (FE) polarization during voltage sweeps, device simulations of the TFET are combined with the SS-FeTFET measurement results. Finally, qualitative insight in some peculiarities of the experimental observations is given, such as the apparent coercive voltage that is larger in the SS-FeTFET than in the standalone FE, the shape of the polarization during voltage sweeps, and the small polarization hysteresis loop at voltages close to the apparent coercive voltage

Near Hysteresis-Free Negative Capacitance InGaAs Tunnel FETs with Enhanced Digital and Analog Figures of Merit below V-DD=400mV

We report the universal boosting impact of a true negative capacitance (NC) effect on digital and analog performances of Tunnel FETs (TFETs), mirrored for the first time in near hysteresis-free experiments and exploiting the S-shaped polarization characteristics. Well behaved InGaAs TFETs with a minimum swing of 55 mV/dec at room temperature are combined with high-quality single crystalline PZT capacitors, placed in series with the gate. When fully satisfying the exact NC matching conditions by a single crystalline ferroelectric that can perform a mono-domain state, a hysteresis-free (sub-10 mV over 4 decades of current) NC-TFET with a sub-thermionic swing and an SS. of 40 mV/dec is demonstrated. In other devices, improvement in the subthreshold swing, down to 30 mV/dec, and analog current efficiency factor, up to 180 V-1, are achieved in NC-TFETs with a hysteresis as small as 30 mV. Importantly, the I-60 FoM of the TFET is improved up to 2 orders of magnitude. The supply voltage is thereby reduced by 50%, down to 300 mV, providing the same drive current. Our results show that NC can open a new direction as a universal performance booster in the FET design by significantly improving the low I-60 and low overdrive of TFETs

Corrections to “Experimental Details of a Steep-Slope Ferroelectric InGaAs Tunnel-FET With High-Quality PZT and Modeling Insights in the Transient Polarization”

This correspondence highlights that the Gibbs free energy description of a ferroelectric capacitor in series with a paraelectric capacitor, depends on the initial charge on the plates of the ferroelectric capacitor. An incomplete Gibbs free energy description, as in the original manuscript, leads to an incorrect simulation result. Therefore, a fully comprehensive analytical description and a corrected conclusion concerning the particular point of an increase in apparent coercive voltage in the steep-slope ferroelectric tunnel-FET, are presented

Gut hormone profiles in critically ill neonates on extracorporeal membrane oxygenation.

Item does not contain fulltextOBJECTIVES: The objective of this study was to gain insight into the hormonal responses to enteral nutrition in critically ill newborns requiring venoarterial extracorporeal membrane oxygenation (ECMO) by analyzing plasma gut hormone levels of gastrin, cholecystokinin and peptide-YY in relation to enteral nutrition. METHODS: In 24 consecutive neonates treated with venoarterial ECMO intestinal hormone secretions were determined by radioimmunoassay at 2-day intervals. Twelve received parenteral nutrition only. In 12 enteral nutrition was introduced later. The findings in these patients were compared with those of 16 measurements in eight non-ECMO treated age-matched controls. Mixed model analysis of variance was used for statistical analysis. RESULTS: Concentrations of gastrin, cholecystokinin and peptide-YY were significantly higher in ECMO patients receiving enteral nutrition compared with ECMO patients who received parenteral nutrition (62, 3.8 and 59.4 pmol/L versus 46, 3.1 and 34.7 pmol/L, respectively). Overall, plasma hormone levels did not differ from those in age-matched controls. CONCLUSIONS: Intestinal hormone levels showed normal responses after introduction of enteral feeding, comparable with those in age-matched controls without ECMO. These results do not provide an argument for withholding enteral nutrition even in the most severely ill neonates on venoarterial ECMO

Use of health and school-based services in Australia by young people with attention-deficit/hyperactivity disorder

Copyright 2004 (C) American Academy of Child and Adolescent PsychiatryOBJECTIVE: To examine use of health (including psychiatric) and school-based services by children and adolescents who met symptom criteria for attention-deficit/hyperactivity disorder (ADHD), the factors associated with service use, and barriers to service access. METHOD: The relationship between parents’ perceptions of children’s need for professional help, the impact of children’s problems on children and parents, and services used during the previous 6 months were examined in a national sample of 398 children and adolescents with ADHD symptoms aged 6 to 17 years (70% response rate). Information was obtained from parents who completed the Diagnostic Interview Schedule for Children Version IV and standard questionnaires. Data collection took place between February and May 1998. RESULTS: Only 28% of those with ADHD symptomatology had attended health or school-based services. Among these, 41% had attended both health and school-based services, 39% had attended only health services, and 20% had attended only school-based services. Sixty-nine percent of parents attending health services wanted additional help. Parental perceptions that children needed professional help, children’s functional impairment, the impact of problems on parents, and comorbid depressive or conduct disorders had a significant and independent relationship with service use. CONCLUSIONS: A minority of children and adolescents with ADHD symptomatology receives professional help for their problems in Australia. Counseling is the most frequent help provided, with many parents wanting additional help beyond that already provided. Factors other than children’s ADHD symptomatology have a significant relationship with service attendance. Practical issues, including the cost of services and waiting lists are the most common barriers cited by parents as hindering access to services.Michael Gifford Sawyer, Joseph Rey, Fiona Marie Arney, Justine Nikola Whitham, Jennifer Joy Clark and Peter Adrian Baghurs

P-Factor(s) for Youth Psychopathology Across Informants and Models in 24 Societies

Objective: Although the significance of the general factor of psychopathology (p) is being increasingly recognized, it remains unclear how to best operationalize and measure p. To test variations in the operationalizations of p and make practical recommendations for its assessment, we compared p-factor scores derived from four models. Methods: We compared p scores derived from principal axis (Model 1), hierarchical factor (Model 2), and bifactor (Model 3) analyses, plus a Total Problem score (sum of unit-weighted ratings of all problem items; Model 4) for parent- and self-rated youth psychopathology from 24 societies. Separately for each sample, we fitted the models to parent-ratings on the Child Behavior Checklist for Ages 6-18 (CBCL/6-18) and self-ratings on the Youth Self-Report (YSR) for 25,643 11-18-year-olds. Separately for each sample, we computed correlations between p-scores obtained for each pair of models, cross-informant correlations between p-scores for each model, and Q-correlations between mean item x p-score correlations for each pair of models. Results: Results were similar for all models, as indicated by correlations of .973-.994 between p-scores for Models 1-4, plus similar cross-informant correlations between CBCL/6-18 and YSR Model 1-4 p-scores. Item x p correlations had similar rank orders between Models 1-4, as indicated by Q correlations of .957-.993. Conclusions: The similar results obtained for Models 1-4 argue for using the simplest model - the unit-weighted Total Problem score - to measure p for clinical and research assessment of youth psychopathology. Practical methods for measuring p may advance the field toward transdiagnostic patterns of problems