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Two-photon lithography (TPL) is a high-resolution additive manufacturing (AM) technique capable of producing arbitrarily complex three-dimensional (3D) microstructures with features 2-3 orders of magnitude finer than human hair. This process finds numerous applications as a direct route toward the fabrication of novel optical and mechanical metamaterials, miniaturized optics, microfluidics, biological scaffolds, and various other intricate 3D parts. As TPL matures, metrology and inspection become a crucial step in the manufacturing process to ensure that the geometric form of the end product meets design specifications. X-ray-based computed tomography (CT) is a nondestructive technique that can provide this inspection capability for the evaluation of complex internal 3D structure. However, polymeric photoresists commonly used for TPL, as well as other forms of stereolithography, poorly attenuate X-rays due to the low atomic number (Z) of their constituent elements and therefore appear relatively transparent during imaging. Here, we present the development of optically clear yet radiopaque photoresists for enhanced contrast under X-ray CT. We have synthesized iodinated acrylate monomers to formulate high-Z photoresist materials that are capable of forming 3D microstructures with sub-150 nm features. In addition, we have developed a formulation protocol to match the refractive index of the photoresists to the immersion medium of the objective lens so as to enable dip-in laser lithography, a direct laser writing technique for producing millimeter-tall structures. Our radiopaque photopolymer resists increase X-ray attenuation by a factor of more than 10 times without sacrificing the sub-150 nm feature resolution or the millimeter-scale part height. Thus, our resists can successfully replace existing photopolymers to generate AM parts that are suitable for inspection via X-ray CT. By providing the "feedstock" for radiopaque AM parts, our resist formulation is expected to play a critical role in enabling fabrication of functional polymer parts to tight design tolerances.

Background: Personal control over end-of-life (EOL) care via advance care planning is a key component of high-quality care. Although this desire for control has been well documented in some populations, EOL care issues are not well understood within the disabilities community., Objective: The objective for this study was to describe the relationships between individual demographic characteristics, health-related quality of life, health locus of control, and attitudes toward advance directives (ADs) in individuals who are disabilities activists., Methods: We surveyed 55 participants attending a disability conference. Instruments included a demographic data sheet, the Advance Directive Attitude Survey (ADAS), the Multidimensional Health Locus of Control scale, and the Functional Assessment of Non-Life Threatening Conditions quality of life (QOL) scale., Results: Most participants were Hispanic females with some college education. About 46% had a disability. Group means revealed a high level of QOL (M=75.72, SD=19.09) and a positive attitude about ADs (M=66.49, SD=8.03). On the Opportunities for Treatment Choices subscale of the ADAS, activists without disabilities (M=14.23) were more positive about their control over EOL decisions than were the activists with disabilities (M=12.97) [t(2,52)=2.116, p<0.05]., Conclusions: Although participants were positive about ADs, differences in attitudes about control over opportunities for treatment choices between the nondisabled and disabled groups support previous findings that people with disabilities may have concerns regarding undertreatment for serious health conditions. Further study of EOL care issues for persons with disabilities is warranted.

The aim of this qualitative descriptive study, guided by Antonovsky's salutogenic model, was to explore the manifestations of strength within the interviews of Spanish-speaking Mexican-American women aging with mobility impairments who also experienced intimate partner violence (IPV). IPV events gleaned from 26 audiotaped interviews from 7 Spanish-speaking Mexican-American women, who ranged in age from 55 to 75 years, constituted the sample for this secondary analysis. Five categories were identified: abuse from early on that shaped sense of coherence; violencia tan cruel--threatened sense of coherence; "salutogenic" choices within the context of IPV; a quest for peace; and strength amid struggle.

Real-time measurement of specific biomolecular interactions is critical to many areas of biological research. A number of label-free techniques for directly monitoring biomolecular binding have been developed, but it is still challenging to measure the binding kinetics of very small molecules, to detect low concentrations of analyte molecules, or to detect low affinity interactions. In this study, we report the development of a highly sensitive photonic crystal biosensor for label-free, real-time biomolecular binding analysis. We characterize the performance of this biosensor using a standard streptavidin-biotin binding system. Optimization of the surface functionalization methods for streptavidin immobilization on the silica sensing surface is presented, and the specific binding of biotinylated analyte molecules ranging over 3 orders of magnitude in molecular weight, including very small molecules (<250 Da), DNA oligonucleotides, proteins, and antibodies (>150 000 Da), are detected in real time with a high signal-to-noise ratio. Finally, we document the sensor efficiency for low mass adsorption, as well as multilayered molecular interactions. By all important metrics for sensitivity, we anticipate this photonic crystal biosensor will provide new capabilities for highly sensitive measurements of biomolecular binding.

We report generation of ballistic electric currents in unbiased epitaxial graphene at 300 K via quantum interference between phase-controlled cross-polarized fundamental and second harmonic 220 fs pulses. The transient currents are detected via the emitted terahertz radiation. Because of graphene's special structure symmetry, the injected current direction can be well controlled by the polarization of the pump beam in epitaxial graphene. This all optical injection of current provides not only a noncontact way of injecting directional current in graphene but also new insight into optical and transport process in epitaxial graphene.

The substrate-induced charge-density profile in carbon face epitaxial graphene is determined using nondegenerate ultrafast midinfrared pump-probe spectroscopy. Distinct zero crossings in the differential transmission spectra are used to identify the Fermi levels of layers within the multilayer stack. Probing within the transmission window of the SiC substrate, we find the Fermi levels of the first four heavily doped layers to be, respectively, 360, 215, 140, and 93 meV above the Dirac point. The charge screening length is determined to be one graphene layer, in good agreement with theoretical predictions.

A novel optical biosensor using a one-dimensional photonic crystal structure in a total-internal-reflection geometry (PC-TIR) is presented and investigated for label-free biosensing applications. This simple configuration forms a micro Fabry-Perot resonator in the top layer which provides a narrow optical resonance to enable label-free, highly sensitive measurements for the presence of analytes on the sensing surface or the refractive index change of the surrounding medium in the enhanced evanescent field; and at the same time it employs an open sensing surface for real-time biomolecular binding detection. The high sensitivity of the sensor was experimentally demonstrated by bulk solvent refractive index changes, ultrathin molecular films adsorbed on the sensing surface, and real-time analytes binding, measuring both the spectral shift of the photonic crystal resonance and the change of the intensity ratio in a differential reflectance measurement. Detection limits of 7x10(-8) RIU for bulk solvent refractive index, 6x10(-5) nm for molecular layer thickness and 24 fg/mm(2) for mass density were obtained, which represent a significant improvement relative to state-of-the-art surface-plasmon-resonance (SPR)-based systems. The PC-TIR sensor is thus seen to be a promising technology platform for high sensitivity and accurate biomolecular detection.

We investigate the ultrafast relaxation dynamics of hot Dirac fermionic quasiparticles in multilayer epitaxial graphene using ultrafast optical differential transmission spectroscopy. We observe differential transmission spectra which are well described by interband transitions with no electron-hole interaction. Following the initial thermalization and emission of high-energy phonons, the electron cooling is determined by electron-acoustic phonon scattering, found to occur on the time scale of 1 ps for highly doped layers, and 4-11 ps in undoped layers. The spectra also provide strong evidence for the multilayer structure and doping profile of thermally grown epitaxial graphene on SiC.

A novel optical sensor for label-free biomolecular binding assay using a one-dimensional photonic crystal in a total-internal-reflection geometry is proposed and demonstrated. The simple configuration provides a narrow optical resonance to enable sensitive measurements of molecular binding, and at the same time employs an open interface to enable real-time measurements of binding dynamics. Ultrathin aminopropyltriethoxysilane/ glutaraldehyde films adsorbed on the interface were detected by measuring the spectral shift of the photonic crystal resonance and the intensity ratio change in a differential reflectance measurement. A detection limit of 6 x 10(-5) nm for molecular layer thickness was obtained, which corresponds to a detection limit for analyte adsorption of 0.06 pg/mm(2) or a refractive index resolution of 3 x 10(-8) RIU; this represents a significant improvement relative to state-of-the-art surface-plasmon-resonance-based systems.

This study focused on behavior modification and enhancement of knowledge concerning home asthma management. The intervention focused on asthma awareness, severity assessment, medication use, and development of management plans while building a support group. The quasi-experimental design utilized various tools to evaluate knowledge, behavior modification, and self-care management. A 25% increase in knowledge and a 13% decrease in emergency department visits was identified over the 12-month period of the study.