Concept: Conversion of units
In patients with cutaneous melanoma, mitotic rate (MR) historically has been reported as the number of mitoses per high-power field (hpf) or per 10 hpf. The most recent revision of the American Joint Committee on Cancer melanoma staging system now incorporates MR and specifies that MR should be reported as mitoses per mm(2), with a conversion factor of 1 mm(2) equaling 4 hpf. However, because many pathologists continue to report MR in hpf units, we sought to compare the 2 conventions for reporting MR; this is important now that MR is used for staging and prognostic information.
Abstract Objectives. Because of its good matching performance the VITA 3D-Master shade guide (3D) is frequently used for determination of tooth color. Numerous composites/ceramics are, however, available in VITA Classical (VC) shades only. The objective of this study was to investigate the possibility of performing a shade match with 3D Master and converting this result via a table in a VC shade (indirect method) without this resulting in an apparent inferior shade matching in comparison with direct shade matching with the VC. Methods. Experiments were performed with an artificial, computer-generated tooth color space. Conversion tables were generated by calculating the color difference (ΔE) between a 3D shade and the closest VC shade (simple conversion table) and with the aid of optimization procedures. Statistical differences between the direct and indirect methods and between the indirect methods were assessed by use of a U-test. Results. Median ΔE was 2.38 for direct matching with the VC and 2.86 for indirect matching by use of a simple conversion table (p < 0.01). Optimized tables performed slightly better (median ΔE = 2.81). Conclusions. Within the limitations of the study, it is usually possible to determine tooth color with the 3D and convert it, via a table, into a VC shade without adding a clinically apparent error to the direct shade match with the VC.
While several thousand square kilometers of land area have been subject to surface mining in the Central Appalachians, no reliable estimate exists for how much coal is produced per unit landscape disturbance. We provide this estimate using regional satellite-derived mine delineations and historical county-level coal production data for the period 1985-2005, and further relate the aerial extent of mining disturbance to stream impairment and loss of ecosystem carbon sequestration potential. To meet current US coal demands, an area the size of Washington DC would need to be mined every 81 days. A one-year supply of coal would result in ∼2,300 km of stream impairment and a loss of ecosystem carbon sequestration capacity comparable to the global warming potential of >33,000 US homes. For the first time, the environmental impacts of surface coal mining can be directly scaled with coal production rates.
Two new D-π-A sensitizers ( and ) incorporating 5H-[1,2,5]thiadiazolo [3,4-f]isoindole-5,7(6H)-dione and 6H-pyrrolo[3,4-g]quinoxaline-6,8(7H)-dione core structures were synthesized and tested in liquid dye-sensitized solar cells (DSCs). achieved a promising power conversion efficiency (PCE) of 6.2% (AM 1.5, 100 mW cm(-2)).
Relative-value units (RVUs) were developed in 1988 as a method of accounting for physicians' work effort and hospital or clinic expenses. Because RVUs provided a uniform, formulaic metric for myriad clinical services, they quickly became the prevailing method for setting fee-for-service payments for Medicare and private insurance. However, the dominance of the fee-for-service model has created strong structural impediments to physicians' participation in value-focused health care.(1) The success of new models of care will require not only changes in the way that health systems are organized and paid but also vigorous engagement by generalists and specialists, yet RVU formulas for . . .
Medication overdoses are a common, but preventable, problem among children. Volumetric dosing errors and the use of incorrect dosing delivery devices are 2 common sources of these preventable errors for orally administered liquid medications. To reduce errors and increase precision of drug administration, milliliter-based dosing should be used exclusively when prescribing and administering liquid medications. Teaspoon- and tablespoon-based dosing should not be used. Devices that allow for precise dose administration (preferably syringes with metric markings) should be used instead of household spoons and should be distributed with the medication.
Recently, a growing number of Item-Response Theory (IRT) models has been published, which allow estimation of a common latent variable from data derived by different Patient Reported Outcomes (PROs). When using data from different PROs, direct estimation of the latent variable has some advantages over the use of sum score conversion tables. It requires substantial proficiency in the field of psychometrics to fit such models using contemporary IRT software. We developed a web application ( http://www.common-metrics.org ), which allows estimation of latent variable scores more easily using IRT models calibrating different measures on instrument independent scales.
Light irradiance through novel CAD-CAM block materials and degree of conversion of composite cements
- Dental materials : official publication of the Academy of Dental Materials
- Published 18 days ago
To assess light irradiance (LI) delivered by two light-curing units (LCU’s) and to measure the degree of conversion (DC) of three composite cements, when cured through different thicknesses of two novel CAD-CAM block materials.
Prevention of neonatal unplanned extubations in the neonatal intensive care unit: a best practice implementation project
- JBI database of systematic reviews and implementation reports
- Published 28 days ago
Adverse events of mechanically ventilated neonates such as unplanned extubations may be associated with serious negative outcomes. Unplanned extubation rates have been monitored by many neonatal intensive care units as a quality of care metric.
To investigate the relationship in dental Cone-Beam CT (CBCT) between the manufacturer-reported image pixel data and a modified conversion to CT number densities in Hounsfield Units (HU).