Three-dimensional automated nanoparticle tracking using Mie scattering in an optical microscope.

The forward scattering of light in a conventional inverted optical microscope by nanoparticles ranging in diameter from 10 to 50nm has been used to automatically and quantitatively identify and track their location in three-dimensions with a temporal resolution of 200ms. The standard deviation of the location of nominally stationary 50-nm-diameter nanoparticles was found to be about 50nm along the light path and about 5nm in the plane perpendicular to the light path. The method is based on oscillating the microscope objective along the light path using a piezo actuator and acquiring images with the condenser aperture closed to a minimum to enhance the effects of diffraction. Data processing in the time and spatial domains allowed the location of particles to be obtained automatically so that the technique has potential applications both in the processing of nanoparticles and in their use in a variety of fields including nanobiotechnology, pharmaceuticals and food processing where a simple optical microscope maybe preferred for a variety of reasons.

(12)C2H2-Ar van der Waals complex.

New theoretical and experimental results on the acetylene-Ar van der Waals complex are presented and the literature is reviewed. New ab initio calculations at the MP2 level were performed using large basis sets with diffuse functions and taking into account the basis set superposition error. It was found that the structure of acetylene is not significantly altered by the complexation and that its vibrational frequencies are only slightly lowered. Finally, it was observed that the calculated properties of the complex (structure, vibrational spectrum, bond dissociation energy) are not sensitive to the structure imposed on acetylene. Experimentally, acetylene-Ar was produced in a supersonic expansion under experimental conditions corresponding to 9 K rotational temperature. Thanks to the performances of CW-CRDS detection, the K(a) = 0 <-- 1, 1 <-- 0, and 2 <-- 1 sub-bands of the nu(1) + nu(3) band could be recorded and resolved and most of their lines assigned. Upper-state rotational constants were fitted, however not including the upper K(a) = 2 state, which shows K-doubling the opposite of the expected. The Lorentzian width of most line profiles sets the mean lifetime to some 7.5 ns. Local perturbations affecting line positions and/or line widths are demonstrated. Additional series of lines tentatively attributed to acetylene-Ar are discussed.

The social HMOs. Meeting the challenge of integrated team care coordination.

Four social health maintenance organizations (social HMOs) implemented care coordination programs in 1985 to integrate acute and long-term care for aged Medicare beneficiaries. The team approach to care coordination has been the key concept of the model at all four sites. Team members include the primary care physician, the care coordinator, inpatient and medical office staff, geriatric nurse practitioners, home care nurses and social workers, contracted community-based care staff, and, at three of the sites, volunteers. This article describes how care coordinators work with the health care teams in the social HMOs.

Integrating care for the geriatric patient. Examples from the Social HMO (SHMO).

Managing the care of geriatric patients with chronic disease focuses attention on the functional impairments that place these patients at risk in the home environment. Maintaining patients in their preferred home settings requires physicians to coordinate effective discharge planning and long-term community care resources. A service coordinator or case manager can play a key role in coordinating the broad array of services needed, as well as linking the providers involved. A coordinated acute and long-term care service delivery system is described, with examples from the Social HMO (SHMO). Data are presented on SHMO enrollee demographic characteristics, chronic disease conditions and functional levels, as well as data on care plans, utilization and costs. A case example illustrates how ongoing medical and long-term care are integrated. Implications for geriatric care and HMO practice are discussed, with recommendations for improving geriatric care in the next generation of SHMO sites.

Across the great divide. Integrating acute, post-acute and long-term care.

The importance of integrating acute, post-acute and long-term care is underscored by analyses of the extent of medical complexity among the SHMO enrollee population that qualified for a long-term care benefit on functional (not medical) criteria. In the SHMO programs, initiatives to promote integration of services at all levels of care have largely come from the care management units. Integrative practices will vary in different organizational settings. Examples from two very different SHMO sites illustrate how integrative practices are implemented. It is concluded that in order to serve adequately a medically complex and functionally impaired elder population a key function of care management is to develop cooperative relationships, and mechanisms for information exchange, with providers at all system levels, reaching across the great divide between the acute and long-term care systems.

Variations in care planning practice in the social/HMO: an exploratory study.

In this exploratory study, we examined the influence of provider settings, organizational structures, and community climates on long-term care resource allocation. We analyzed care plan decisions at each of the four Social/HMO sites for the same seven clients. Differences by site were found in eligibility determination and allocation of care plans, as well as types and mix of services prescribed. Issues are raised about the influence of provider settings on legitimation of types of needs and clients that are served.

Impedance cardiography. Current status and clinical applications.

Impedance cardiography is a highly reproducible, rapid and safe method for the evaluation of cardiac performance in the clinical setting. Measurements of stroke volume (SV), end diastolic volume (EDV), and end systolic volume (ESV) with calculation of cardiac output (CO) were obtained in normal, healthy people (group 1, n = 21) and in patients with congestive heart failure (group 2, n = 18). Individuals were placed on a tilt table and cardiac profiles (measurements of CO, SV, EDV, and ESV) were performed at 45 degrees head up, 15 degrees head up, and supine. Group 1 responded by increasing CI from 2.9 +/- 0.81 L/min/M2 at 45 degrees to 3.3 +/- 1.0 L/min/M2 at 15 degrees to 3.7 +/- 1.0 L/min/M2 supine. There was no corresponding rise seen in group 2, with CIs of 2.1 +/- 0.83 L/min/M2, 2.0 +/- 0.78 L/min/M2 and 2.0 +/- 0.76 L/min/M2 at each position, respectively. In addition, while the EDV increased at each position in group 1 (45 degrees: 71 +/- 21 cc/M2, 15 degrees: 88 +/- 26 cc/M2, Supine: 102 +/- 29 cc/M2), no such increase was evident in group 2 (45 degrees: 57 +/- 29 cc/M2, 15 degrees: 52 +/- 20 cc/M2, Supine: 60 +/- 24 cc/M2). The inability of group 2 patients to elevate CI and the absence of any discernible change in EDV suggests an insufficiency of cardiac reserve with noncompliant ventricles. This information is currently being used to assess operative risk and to study effects of treatment modalities.