The Effective Potential in Device Modeling: The Good, the Bad and the Ugly

We discuss the use of the effective potential to incorporate quantum effects in device models. While threshold shifts and charge set-back are handled well, tunneling is not well handled by this approach, or by any other local potential approach.     

A Wigner Function Based Ensemble Monte Carlo Approach for Accurate Incorporation of Quantum Effects in Device Simulation

We present results of both Gaussian wave-packet tunneling though a single barrier structure and RTD operation achieved from a particle-based Ensemble Monte Carlo (EMC) simulation that is based on the Wigner distribution function (WDF). Methods of including the Wigner potential into the EMC, to incorporate naturally quantum phenomena, via a particle property we call the affinity are discussed. Results showing tunneling and correlation build-up in both cases are presented.     

Judgments about estrogen replacement therapy: The role of age, cognitive abilities, and beliefs.

This study investigated age, cognitive abilities, health beliefs, and other factors in women's judgments about effective treatments for menopause. Women (N?=?102) ranging in age from 20 to 79 read a vignette about a woman facing a decision about Estrogen Replacement Therapy (ERT) and then made judgments about what should be done. Participants also completed a battery of questions pertaining to ERT and cognitive abilities. Path-analytic techniques were used to determine the role of specific cognitive abilities and the representation of menopause and its treatment in making judgments about ERT treatments. Cognitive abilities had direct effects on treatment decisions. Education affected the number of perceived options for treatment. Age and education indirectly affected treatment decisions, operating through cognitive abilities. Factors related to the mental representation of menopause had no direct effects and few indirect effects on treatment decisions. Potential mechanisms that can help older adults compensate for declines in cognitive abilities in medical decisions are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A 90-nm logic technology featuring strained-silicon

A leading-edge 90-nm technology with 1.2-nm physical gate oxide, 45-nm gate length, strained silicon, NiSi, seven layers of Cu interconnects, and low-/spl kappa/ CDO for high-performance dense logic is presented. Strained silicon is used to increase saturated n-type and p-type metal-oxide-semiconductor field-effect transistors (MOSFETs) drive currents by 10% and 25%, respectively. Using selective epitaxial Si/sub 1-x/Ge/sub x/ in the source and drain regions, longitudinal uniaxial compressive stress is introduced into the p-type MOSEFT to increase hole mobility by >50%. A tensile silicon nitride-capping layer is used to introduce tensile strain into the n-type MOSFET and enhance electron mobility by 20%. Unlike all past strained-Si work, the hole mobility enhancement in this paper is present at large vertical electric fields in nanoscale transistors making this strain technique useful for advanced logic technologies. Furthermore, using piezoresistance coefficients it is shown that significantly less strain (/spl sim/5 /spl times/) is needed for a given PMOS mobility enhancement when applied via longitudinal uniaxial compression versus in-plane biaxial tension using the conventional Si/sub 1-x/Ge/sub x/ substrate approach.     

Personality counts for a lot: predictors of mental and physical health of spouse caregivers in two disease groups

The purpose of this study were to examine the influence of personality on mental and physical health of spouse caregivers and to determine whether there were differences in such influences depending on disease context. The disease contexts compared were Alzheimer's disease (AD) and Parkinson's disease (PD; with no coexisting dementia)--both chronic, degenerative diseases of later life. It was predicted that personality would be related to mental and physical health, directly and indirectly, and that AD caregivers would have higher levels of perceived stress and worse mental and physical health outcomes. Participants in the study were 175 caregivers (88 AD; 87 PD) living at home with their ill spouses. The data provided an excellent fit to the hypothesized model of the relationships between personality, disease group, social support, perceived stress, and mental and physical health. Seventy-eight percent of the variance in mental health was accounted for and 35% of the variance in physical health was explained. Personality had significant direct and indirect effects on mental health and significant indirect effects on physical health. As predicted, AD caregivers had significantly worse mental health than PD caregivers; however, AD caregivers had better physical health than PD caregivers, controlling for other variables in the model. These results are discussed in relation to the existing caregiving and behavioral medicine literature. Future research should include different domains of personality--states and longer term self-regulatory processes in addition to traits--to advance models of caregiving processes further.     

Mental and physical health of spouse caregivers: The role of personality.

Although personal resources of caregivers, such as coping skills and social support, have been shown to be important in understanding caregiver stress and health outcomes, personality traits have not previously been considered. The purpose of this study was to examine the association between the personality traits of neuroticism and dispositional optimism and mental and physical health outcomes. It was predicted that personality would have direct effects, and indirect effects through perceived stress, on health outcomes. Participants were spouse caregivers of patients diagnosed with Alzheimer's disease (AD). Results show that neuroticism and optimism were significantly related to mental and physical health. Furthermore, neuroticism had significant direct effects on all of the health outcomes, and substantial indirect effects, through perceived stress, on mental health outcomes. Optimism showed stronger indirect than direct effects on all health outcomes. These findings demonstrate the importance of including personality of the caregiver in theoretical and empirical models of the caregiving process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of band warping and wafer orientation on NMOS mobility under arbitrary applied stress

We have developed a novel simulation approach to model electron mobility in the inversion layer which encompasses all the important effects of arbitrary wafer and applied stress orientations, such as carrier re-population, band warping, and scattering, going beyond the separate treatments of band warping and inversion anisotropy that have been demonstrated. Our model predicts an important consequence of electron band warping in retaining the increase of stress gain at high stress levels in the presence of shear stress at strong inversion.     

A logic nanotechnology featuring strained-silicon

Strained-silicon (Si) is incorporated into a leading edge 90-nm logic technology . Strained-Si increases saturated n-type and p-type metal-oxide-semiconductor field-effect transistors (MOSFETs) drive currents by 10 and 25%, respectively. The process flow consists of selective epitaxial Si/sub 1-x/Ge/sub x/ in the source/drain regions to create longitudinal uniaxial compressive strain in the p-type MOSFET. A tensile Si nitride-capping layer is used to introduce tensile uniaxial strain into the n-type MOSFET and enhance electron mobility. Unlike past strained-Si work: 1) the amount of strain for the n-type and p-type MOSFET can be controlled independently on the same wafer and 2) the hole mobility enhancement in this letter is present at large vertical electric fields, thus, making this flow useful for nanoscale transistors in advanced logic technologies.     

Ovarian steroid regulation of vascular endothelial growth factor in the human endometrium: implications for angiogenesis during the menstrual cycle and in the pathogenesis of endometriosis

The human endometrium undergoes a complex process of vascular and glandular proliferation, differentiation, and regeneration with each menstrual cycle in preparation for implantation. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific angiogenic protein that appears to play an important role in both physiological and pathological neovascularization. To investigate whether VEGF may regulate human endometrial angiogenesis, we examined VEGF messenger ribonucleic acid (mRNA) and protein throughout the menstrual cycle and studied the regulation of VEGF by reproductive steroids in isolated human endometrial cells. By ribonuclease protection analysis, VEGF mRNA increased relative to early proliferative phase expression by 1.6-,2.0-, and 3.6-fold in midproliferative, late proliferative, and secretory endometrium, respectively. In histological sections, VEGF mRNA and protein were localized focally in glandular epithelial cells and more diffusely in surrounding stroma, with greatest VEGF expression in secretory endometrium. Consistent with these in vivo results, the treatment of isolated human endometrial cells with estradiol (E2), medroxyprogesterone acetate (MPA), or E2 plus MPA significantly increased VEGF mRNA expression over the control value by 3.1-, 2.8-, and 4.7-fold, respectively. The VEGF response to E2 was rapid, with steady state levels of VEGF mRNA reaching 85% maximum 1 h after the addition of steroid. E2 also caused a 46% increase in secreted VEGF protein, and the combination of E2 and MPA caused an 18% increase. VEGF expression in endometriosis, an angiogenesis-dependent, estrogen-sensitive disease was similar to that seen in eutopic endometrium. Peritoneal fluid concentrations of VEGF were significantly higher in women with moderate to severe endometriosis than in women with minimal to mild endometriosis or no disease. VEGF, therefore, may be important in both physiological and pathological angiogenesis of human endometrium, as it is an estrogen-responsive angiogenic factor that varies throughout the menstrual cycle and is elevated in women with endometriosis.     

The dual crisis: Mental illness and substance abuse: Present and future directions.

Describes recent federal initiatives to focus attention on the needs of young adults (aged 18–40 yrs) with concurrent mental health and substance abuse problems, summarizes research findings on persons with these dual disabilities, and presents an agenda for future epidemiological, clinical, and basic research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)