Simulations of solar cell absorption enhancement using resonant modes of a nanosphere array

We propose an approach for enhancing the absorption of thin-film amorphous silicon solar cells using periodic arrangements of resonant dielectric nanospheres deposited as a continuous film on top of a thin planar cell. We numerically demonstrate this enhancement using 3D full field finite difference time domain simulations and 3D finite element device physics simulations of a nanosphere array above a thin-film amorphous silicon solar cell structure featuring back reflector and anti-reflection coating. In addition, we use the full field finite difference time domain results as input to finite element device physics simulations to demonstrate that the enhanced absorption contributes to the current extracted from the device. We study the influence of a multi-sized array of spheres, compare spheres and domes and propose an analytical model based on the temporal coupled mode theory

Image patterned molecular delivery into live cells using gold particle coated substrates.

An image-patterned molecular delivery system for mammalian cells is demonstrated by pulsed laser irradiation of gold particles immobilized on a substrate below a cell monolayer. Patterned cavitation bubble nucleation was captured using a time-resolved imaging system and molecular delivery verified by observing the uptake of a membrane-impermeable fluorescent dye, calcein. Delivery efficiency as high as 90% was observed and multiplexed, patterned dye delivery was demonstrated

Integrated Circuit (IC) Chip with a Self-Contained Fluid Sensor and Method of Making the Chip

An integrated circuit (IC) chip with a self-contained fluid sensor and method of making the chip. The sensor is in a conduit formed between a semiconductor substrate and a non-conductive cap with fluid entry and exit points through the cap. The conduit may be entirely in the cap, in the substrate or in both. The conduit includes encased temperature sensors at both ends and a central encased heater. The temperature sensors may each include multiple encased diodes and the heater may include multiple encased resistors

Redesigning Systems of Care for Older Adults with Alzheimer' Disease

Best-practice models of dementia care have evolved from strategies focused on family caregivers to guidelines predicated on supporting the patient-caregiver dyad along the care continuum. These models have grown in complexity to encompass medical and team-based care that is designed to coordinate dementia care across settings and providers for a defined population of patients. Although there is evidence that the models can improve outcomes, they have not been widely adopted. Barriers to the models' increased adoption include workforce limitations, the cost of necessary practice redesign, and limited evidence of their potential cost-effectiveness. We summarize the origins, evidence base, and common components of best-practice models of dementia care, and we discuss barriers to their implementation. We conclude by describing two current efforts to implement such models on a broad scale, supported by the Center for Medicare and Medicaid Innovation. Taken together, these models seek to demonstrate improved dementia care quality and outcomes, accompanied by cost savings, in both community-based and institutional care settings

ExO: An Ontology for Exposure Science

An ontology is a formal representation of knowledge within a domain and typically consists of classes, the properties of those classes, and the relationships between them. Ontologies are critically important for specifying data of interest in a consistent manner, thereby enabling data aggregation, analysis and exchange. An exposure ontology, consistent with those being used in toxicology and other health sciences, is required to formally represent exposure concepts, the relationships between these concepts and most important, the relationships between exposure, susceptibility, and toxicology information. A successful exposure ontology must facilitate the semantic retrieval of exposure data in the context of environmental health science, medical surveillance, disease control, health tracking, risk assessment, and other public health and environmental science endeavors. To address this need, an Exposure Ontology, ExO, was designed and a prototype developed to provide the foundation for exposure data centralization and integration. The root classes forming the basis for the ontology are 'exposure event’ ‘exposure stressor', 'exposure receptor', and 'exposure outcome'. Although the initial development of ExO was focused on human exposure to chemicals, the ultimate intent is to provide domains that can be extended to address exposures to the full suite of environmental stressors

Emergency Department Use Among Older Adults With Dementia

Although persons with dementia are frequently hospitalized, relatively little is known about the health profile, patterns of health care use, and mortality rates for patients with dementia who access care in the emergency department (ED). We linked data from our hospital system with Medicare and Medicaid claims, Minimum Data Set, and Outcome and Assessment Information Set data to evaluate 175,652 ED visits made by 10,354 individuals with dementia and 15,020 individuals without dementia over 11 years. Survival rates after ED visits and associated charges were examined. Patients with dementia visited the ED more frequently, were hospitalized more often than patients without dementia, and had an increased odds of returning to the ED within 30 days of an index ED visit compared with persons who never had a dementia diagnosis (odds ratio, 2.29; P<0.001). Survival rates differed significantly between patients by dementia status (P<0.001). Mean Medicare payments for ED services were significantly higher among patients with dementia. These results show that older adults with dementia are frequent ED visitors who have greater comorbidity, incur higher charges, are admitted to hospitals at higher rates, return to EDs at higher rates, and have higher mortality after an ED visit than patients without dementia

The Effects of Supplemental Dietary Chitosan on Broiler Performance and Myopathic Features of White Striping

White striping (WS) is a common myopathy seen in fast-growing broilers. Studies have demonstrated that chitosan is effective as an antioxidant and has antiobesity and fat-absorption reduction properties. We hypothesized that the dietary supplementation of chitosan would have similar effects when fed to fast-growing broilers and would thus lower WS incidence and improve meat quality. One hundred twenty-six broilers were fed corn-soy diets. The grower and finisher diets contained either 0, 0.2, or 0.4% chitosan. After a 6 wk growth period, birds were euthanized, and then WS and gross pathology scores were assessed. Pectoralis major tissues were collected to evaluate cook loss, drip loss, histopathology scores, and the gene expression of CCR7, LECT2, CD36, PPARG, and PTGS2. There were no significant differences between the broiler weights, thus chitosan did not appear to compromise the overall growth of the broilers. Female broilers fed 0.4% chitosan had the lowest WS incidence, while male broiler fed 0.4% chitosan had the least cook loss. However, gene expression analyses did not offer insight into any grossly or histologically visualized differences in the muscles. Thus, while we can postulate that chitosan could have some positive effect in reducing WS incidence and improving meat quality, further studies are required to better scrutinize the mechanisms by which chitosan affects WS and other such myopathies in fast-growing broilers

Extremely broadband ultralight thermally emissive metasurfaces

We report the design, fabrication and characterization of ultralight highly emissive metaphotonic structures with record-low mass/area that emit thermal radiation efficiently over a broad spectral (2 to 35 microns) and angular (0-60 degrees) range. The structures comprise one to three pairs of alternating nanometer-scale metallic and dielectric layers, and have measured effective 300 K hemispherical emissivities of 0.7 to 0.9. To our knowledge, these structures, which are all subwavelength in thickness are the lightest reported metasurfaces with comparable infrared emissivity. The superior optical properties, together with their mechanical flexibility, low outgassing, and low areal mass, suggest that these metasurfaces are candidates for thermal management in applications demanding of ultralight flexible structures, including aerospace applications, ultralight photovoltaics, lightweight flexible electronics, and textiles for thermal insulation

If Cumulative Risk Assessment Is the Answer, What Is the Question?

Cumulative risk refers to the combined threats from exposure via all relevant routes to multiple stressors including biological, chemical, physical, and psychosocial entities. Cumulative risk assessment is a tool for organizing and analyzing information to examine, characterize, and possibly quantify the combined adverse effects on human health or ecologic resources from multiple environmental stressors. The U.S. Environmental Protection Agency (EPA) has initiated a long-term effort to develop future guidelines for cumulative risk assessment, including publication in 2003 of a framework that describes important features of the process and discusses theoretical issues, technical matters, and key definitions. The framework divides the process of cumulative risk assessment into three interrelated phases: a) planning, scoping, and problem formulation; b) analysis; and c) interpretation and risk characterization. It also discusses the additional complexities introduced by attempts to analyze cumulative risks from multiple stressors and describes some of the theoretical approaches that can be used. The development of guidelines for cumulative risk assessment is an essential element in the transition of the U.S. EPA risk assessment methodology from a narrow focus on a single stressor, end point, source, pathway, and exposure route to a broader, more holistic approach involving analysis of combined effects of cumulative exposure to multiple stressors via all relevant sources, pathways, and routes

Transitions in Care in a Nationally Representative Sample of Older Americans with Dementia

OBJECTIVES: To describe transitions in care for older adults with dementia identified from a nationally representative cohort and to describe transition rates in those with more-severe levels of cognitive and functional impairment. DESIGN: Longitudinal cohort study. SETTING: Health and Retirement Study (HRS). PARTICIPANTS: HRS respondents aged 65 and older whose survey data were linked with Medicare claims from 1999 to 2008 (N = 16,186). MEASUREMENTS: Transitions in care between home, home with formal services, hospital, and nursing facility care; cognitive function; activities of daily living; and mortality. RESULTS: The 3,447 (21.3%) HRS subjects who were ever diagnosed with dementia experienced frequent transitions. Of subjects transitioning from a hospital stay, 52.2% returned home without home care services, and 33.8% transitioned to a nursing facility. Of subjects transitioning from a nursing facility, 59.2% transitioned to the hospital, and 25.3% returned home without services. There were 2,139 transitions to death, and 58.7% of HRS subjects with dementia died at home. Even in persons with moderate to severe dementia, multiple transitions in care were documented, including transitions from the hospital to home and back to the hospital. CONCLUSION: In this nationally representative sample of older adults, subjects diagnosed with dementia experience frequent transitions. Persons with dementia who are cared for at home and who transition back to home often have moderate to severe impairments in function and cognition