Ligand enhanced upconversion of near-infrared photons with nanocrystal light absorbers.

We designed and synthesized a tetracene derivative 4-(tetracen-5-yl)benzoic acid (CPT) as a transmitter ligand used in PbS/PbSe nanocrystal (NC) sensitized upconversion of near infrared (NIR) photons. Under optimal conditions, comparing CPT functionalized NCs with unfunctionalized NCs as sensitizers, the upconversion quantum yield (QY) was enhanced 81 times for 2.9 nm PbS NCs from 0.021% to 1.7%, and 11 times for 2.5 nm PbSe NCs from 0.20% to 2.1%. The surface density of CPT controls the solubility of functionalized NCs and the upconversion QY. By increasing the concentration of CPT in the ligand exchange solution, the number of CPT ligand per NC increases. The upconversion QY is maximized at a transmitter density of 1.2 nm-2 for 2.9 nm PbS, and 0.32 nm-2 for 2.5 nm PbSe. Additional transmitter ligands inhibit photon upconversion due to triplet-triplet annihilation (TTA) between two neighboring CPT molecules on the NC surface. 2.1% is the highest reported QY for TTA-based photon upconversion in the NIR with the use of earth-abundant materials

Combining isotonic regression and EM algorithm to predict genetic risk under monotonicity constraint

In certain genetic studies, clinicians and genetic counselors are interested in estimating the cumulative risk of a disease for individuals with and without a rare deleterious mutation. Estimating the cumulative risk is difficult, however, when the estimates are based on family history data. Often, the genetic mutation status in many family members is unknown; instead, only estimated probabilities of a patient having a certain mutation status are available. Also, ages of disease-onset are subject to right censoring. Existing methods to estimate the cumulative risk using such family-based data only provide estimation at individual time points, and are not guaranteed to be monotonic or nonnegative. In this paper, we develop a novel method that combines Expectation-Maximization and isotonic regression to estimate the cumulative risk across the entire support. Our estimator is monotonic, satisfies self-consistent estimating equations and has high power in detecting differences between the cumulative risks of different populations. Application of our estimator to a Parkinson's disease (PD) study provides the age-at-onset distribution of PD in PARK2 mutation carriers and noncarriers, and reveals a significant difference between the distribution in compound heterozygous carriers compared to noncarriers, but not between heterozygous carriers and noncarriers.Comment: Published in at http://dx.doi.org/10.1214/14-AOAS730 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

Psychological characteristics and nursing intervention of adolescent patients with oral cavity

目的  通过对就诊病例的心理特点分析，总结适时的心理护理干预方法。方法  通过对121例青少年患者的心理定势、期待与满意等方面进行总结。结果与结论  充分了解正畸青少年患者的就诊心态，加强对患者心理护理的干预，以达到最佳治疗效果。Objective: Through the analysis of the psychological characteristics of patients with medical treatment, summarize the timely psychological nursing intervention. Methods: Summarize the mental set, expectation and satisfaction of 121 adolescent patients. Results and Conclusion: To fully understand the orthodontic patients of adolescent mentality，strengthen the psychological nursing of patients of intervention，in order to achieve the best therapeutic effect.

Building Grit : The Longitudinal Pathways between Mindset, Commitment, Grit, and Academic Outcomes

Despite academics' enthusiasm about the concept of grit (defined as consistency of interest and perseverance of effort), its benefit for academic achievement has recently been challenged. Drawing from a longitudinal sample (N=2018; 55.3% female; sixth-nineth grades) from Finland, this study first aimed to investigate and replicate the association between grit and achievement outcomes (i.e., academic achievement and engagement). Further, the present study examined whether growth mindset and goal commitment impacted grit and whether grit acted as a mediator between growth mindset, goal commitment, and achievement outcomes. The results showed that the perseverance facet of grit in the eighth grade was associated with school achievement and engagement in the nineth grade, after controlling for students' conscientiousness, academic persistence, prior achievement and engagement, gender and SES, although the effect on engagement was stronger than on achievement. In addition, grit was predicted by goal commitment in the sixth grade, but not by the growth mindset in the sixth grade. Finally, the perseverance of effort (not the consistency of interest) mediated the effect of goal commitment on engagement. These findings suggest that grit is associated with increased engagement and academic achievement; and practitioners who wish to improve grit of adolescents may encourage goal commitment more than growth mindset.Peer reviewe

Putting the Goal Back into Grit : Academic Goal Commitment, Grit, and Academic Achievement

Grit has recently been challenged for its weak predictive power and the incompleteness of its measurement. This study addressed these issues by taking a developmental, person-oriented approach to study academic-related goal commitment and grit and their effects on academic achievement. Using longitudinal data among Finnish eighth and ninth graders (n = 549, 59.4% female, age = 14–16), the longitudinal changes in grit and academic goal commitment profiles were investigated through latent profile and latent transition analyses. Four profiles were identified across two grades: High committed-persistent and moderate consistency (~ 17%), Moderate (~ 60%), Low committed-persistent and moderate-low consistency (~ 8%) and Extremely low committed-persistent and moderate-low consistency (~ 12%). The students in the High committed-persistent and moderate consistency profile had the highest academic achievement of all the profiles when controlled for gender, socioeconomic status, conscientiousness, and academic persistence. The results revealed that students’ profiles changed between the eighth and ninth grades, with more than one-third of the High committed-persistent and moderate consistency adolescents dropping from this group. Further analysis showed that the profiles varied by educational aspiration, gender, and socioeconomic status. These findings imply that the combination of grit and academic goal commitment influences academic achievement; however, this combination is less common, unstable, and affected by internal and external factors. The study provided important implications on the weak grit effect and the ways to improve it.Peer reviewe

Parameterization of directional absorption of orographic gravity waves and its impact on the atmospheric general circulation simulated by the Weather Research and Forecasting Model

In this work, a new parameterization scheme is developed to account for the directional absorption of orographic gravity waves (OGWs) using elliptical mountain wave theory. The vertical momentum transport of OGWs is addressed separately for waves with different orientations through decomposition of the total wave momentum flux (WMF) into individual wave components. With the new scheme implemented in the Weather Research and Forecasting (WRF) model, the impact of directional absorption of OGWs on the general circulation in boreal winter is studied for the first time. The results show that directional absorption can change the vertical distribution of OGW forcing, while maintaining the total column-integrated forcing. In general, directional absorption inhibits wave breaking in the lower troposphere, producing weaker orographic gravity wave drag (OGWD) there and transporting more WMF upwards. This is because directional absorption can stabilize OGWs by reducing the local wave amplitude. Owing to the increased WMF from below, the OGWD in the upper troposphere at midlatitudes is enhanced. However, in the stratosphere of mid-to-high latitudes, the OGWD is still weakened due to greater directional absorption occurring there. Changes in the distribution of midlatitude OGW forcing are found to weaken the tropospheric jet locally and enhance the stratospheric polar night jet remotely. The latter occurs as the adiabatic warming (associated with the OGW-induced residual circulation) is increased at midlatitudes and suppressed at high latitudes, giving rise to stronger thermal contrast. Resolved waves are likely to contribute to the enhancement of polar stratospheric winds as well, because their upward propagation into the high-latitude stratosphere is suppressed

In-gap states with nearly free electron characteristics in layered structure trivalent iridates

Iridium oxides (iridates) provide good platform to study the complex interplay of spin-orbit coupling (SOC) interactions, correlation effects, Hund coupling and lattice degree of freedom. However, previous studies primarily focus on tetravalent (Ir4+, 5d5) and pentavalent (Ir5+, 5d4) iridates. Here, we turn our attention to a recently reported unprecedented trivalent (Ir3+, 5d6) iridates, K0.75Na0.25IrO2, crystalizes in a triangular lattice with edge-sharing IrO6 octahedra and alkali ions intercalated [IrO2]- layers. We theoretically determine the preferred occupied positions of the alkali ions from energetic viewpoints, and reproduce the experimentally observed semiconducting behavior and nonmagnetic (NM) properties. The SOC interactions play a critical role in the band dispersion, resulting in NM Jeff = 0 states. More intriguingly, our electronic structure not only confirms the experimental speculation of the presence of in-gap states and explains the abnormal low activation energy in K0.75Na0.25IrO2, but also puts forward the in-gap states featured with nearly free electron characteristics. Our theoretical results provide new insights into the unconventional electronic structures of the trivalent iridates and imply its promising applications in nanoelectronic devices such as ideal electron transport channels.Comment: 14+15pages,6+6figure

Exploring the excess mortality due to depressive symptoms in a community-based sample: The role of Alzheimer's Disease

BACKGROUND: Depression has been associated with increased risk of death. However, there is lack of studies exploring such relationship in the context of dementia. Given the high prevalence of both depression and Alzheimer's Disease (AD), investigating their temporal association with mortality is of public health relevance. METHODS: Longitudinal data from the WHICAP study were analyzed (1958 individuals aged ≥65 years). Depressive symptoms were assessed with the 10-item Center for Epidemiologic Studies Depression Scale (CES-D). Respondents were identified as having AD if they satisfied the criteria of the National Institute on Aging-Alzheimer's Association workgroups on diagnostic guidelines for Alzheimer's disease. Cox regressions analyses were performed to determine the association between depressive symptoms and risk of all-cause mortality using the overall sample, and by AD status. RESULTS: Depressive symptoms were significantly associated with higher mortality risk after adjusting for all potential covariates in the overall sample (HR=1.22; 95% CI=1.02, 1.46) and in individuals with incident AD (HR=1.88; 95% CI=1.12, 3.18). LIMITATIONS: The CES-D does not measure clinical depression but depressive symptomatology. Since those who were exposed to known risk factors for mortality are likely to die prematurely, our results may have been skewed to the individuals with longer survival. CONCLUSIONS: Strategies focusing on prevention and early treatment of depression in the elderly may have a beneficial effect not only on patient quality of life and disability, but may also increase survival in the context of AD