91 research outputs found
Comparison of balance assessment modalities in emergency department elders: a pilot cross-sectional observational study
<p>Abstract</p> <p>Background</p> <p>More than one-third of US adults 65 and over fall every year. These falls may cause serious injury including substantial long-term morbidity (due declines in activities of daily living) and death. The emergency department (ED) visit represents an opportunity for identifying high risk elders and potentially instituting falls-related interventions. The unique characteristic of the ED environment and patient population necessitate that risk-assessment modalities be validated in this specific setting. In order to better identify elders at risk of falls, we examined the relationship between patient-provided history of falling and two testing modalities (a balance plate system and the timed up-and-go [TUG] test) in elder emergency department (ED) patients.</p> <p>Methods</p> <p>We conducted a cross-sectional observational study of patients ≥ 60 years old being discharged from the ED. Patient history of falls in the past week, month, 6 months, and year was obtained. Balance plate center of pressure excursion (COP) measurements and TUG testing times were recorded. COP was recorded under four conditions: normal stability eyes open (NSEO) and closed (NSEC), and perturbed stability eyes open and closed. Correlation between TUG and COP scores was measured. Univariate logistic regression was used to identify the relationship between patient-provided falls history and the two testing modalities. Proportions, likelihood ratios, and receiver-operating-characteristic (ROC) curves for prediction of previous falls were reported.</p> <p>Results</p> <p>Fifty-three subjects were enrolled, 11% had fallen in the previous week and 42% in the previous year. There was no correlation between TUG and any balance plate measurements. In logistic regression, neither testing modality was associated with prior history of falls (<it>p </it>> 0.05 for all time periods). Balance plate NSEO and NSEC testing cutoffs could be identified which were 83% sensitive and had a negative likelihood ratio (LR-) of 0.3 for falls in the past week. TUG testing was not useful for falls in the past week, but performed best for more distant falls in the past month, 6 months, or year. TUG cutoffs with sensitivity over 80% and LR(-) of 0.17-0.32 could be identified for these time periods.</p> <p>Conclusion</p> <p>Over 40% of community-dwelling elder ED patients report a fall within the past year. Balance plate and TUG testing were feasibly conducted in an ED setting. There is no relationship between scores on balance plate and TUG testing in these patients. In regression analysis, neither modality was significantly associated with patient provided history of falls. These modalities should not be adopted for screening purposes in elders in the ED setting without validation in future studies or as part of multi-factorial risk assessment.</p
Branching and bounding improvements for global optimization algorithms with Lipschitz continuity properties
Global report on preterm birth and stillbirth (2 of 7): discovery science
<p>Abstract</p> <p>Background</p> <p>Normal and abnormal processes of pregnancy and childbirth are poorly understood. This second article in a global report explains what is known about the etiologies of preterm births and stillbirths and identifies critical gaps in knowledge. Two important concepts emerge: the continuum of pregnancy, beginning at implantation and ending with uterine involution following birth; and the multifactorial etiologies of preterm birth and stillbirth. Improved tools and data will enable discovery scientists to identify causal pathways and cost-effective interventions.</p> <p>Pregnancy and parturition continuum</p> <p>The biological process of pregnancy and childbirth begins with implantation and, after birth, ends with the return of the uterus to its previous state. The majority of pregnancy is characterized by rapid uterine and fetal growth without contractions. Yet most research has addressed only uterine stimulation (labor) that accounts for <0.5% of pregnancy.</p> <p>Etiologies</p> <p>The etiologies of preterm birth and stillbirth differ by gestational age, genetics, and environmental factors. Approximately 30% of all preterm births are indicated for either maternal or fetal complications, such as maternal illness or fetal growth restriction. Commonly recognized pathways leading to preterm birth occur most often during the gestational ages indicated: (1) inflammation caused by infection (22-32 weeks); (2) decidual hemorrhage caused by uteroplacental thrombosis (early or late preterm birth); (3) stress (32-36 weeks); and (4) uterine overdistention, often caused by multiple fetuses (32-36 weeks). Other contributors include cervical insufficiency, smoking, and systemic infections. Many stillbirths have similar causes and mechanisms. About two-thirds of late fetal deaths occur during the antepartum period; the other third occur during childbirth. Intrapartum asphyxia is a leading cause of stillbirths in low- and middle-income countries.</p> <p>Recommendations</p> <p>Utilizing new systems biology tools, opportunities now exist for researchers to investigate various pathways important to normal and abnormal pregnancies. Improved access to quality data and biological specimens are critical to advancing discovery science. Phenotypes, standardized definitions, and uniform criteria for assessing preterm birth and stillbirth outcomes are other immediate research needs.</p> <p>Conclusion</p> <p>Preterm birth and stillbirth have multifactorial etiologies. More resources must be directed toward accelerating our understanding of these complex processes, and identifying upstream and cost-effective solutions that will improve these pregnancy outcomes.</p
Products of cultured neuroglial cells: II. The production of fibronectin by C6 glioma cells
The possibility of fibronectin production by C6 glioma cells was examined with assays which require protein synthesis. Proteins produced by C6 cells using radiolabeled amino acid precursors were tested for affinity to collagen by binding to immobilized gelatin. The predominant collagen binding protein made by C6 coelectrophoresed with fibronectin synthesized by control fibroblasts and with the larger of the two proteins in unlabeled fibronectin when applied to polyacrylamide gels with sodium dodecyl sulfate (SDS). In addition, C6 produced a larger collagen binding protein of approximately 270,000 molecular weight. Solubilities in urea solutions of the collagen-binding proteins made by C6 cells and fibroblasts were similar. Immunofluorescence showed fibronectin associated with the C6 cell monolayer, but less abundant than the fibronectin associated with fibroblasts. Results provide evidence for the production of fibronectin by the C6 glioma cell line.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45400/1/11064_2004_Article_BF00964399.pd
Strommessungen und Ozeanographische Serien-Beobachtungen der 4-Länder-Unternehmung im Kattegat : 10-17 August 1931
Rotational spectroscopy and three-wave mixing of 4-carvomenthenol: A technical guide to measuring chirality in the microwave regime
We apply chirality sensitive microwave three-wave mixing to 4-carvomenthenol, a molecule previously uncharacterized with rotational spectroscopy. We measure its rotational spectrum in the 2-8.5 GHz range and observe three molecular conformers. We describe our method in detail, from the initial step of spectral acquisition and assignment to the final step of determining absolute configuration and enantiomeric excess. Combining fitted rotational constants with dipole moment components derived from quantum chemical calculations, we identify candidate three-wave mixing cycles which were further tested using a double resonance method. Initial optimization of the three-wave mixing signal is done by varying the duration of the second excitation pulse. With known transition dipole matrix elements, absolute configuration can be directly determined from a single measurement
Syntheses, Structures, and Characterization of Nickel(II) Stibines: Steric and Electronic Rationale for Metal Deposition
Reactions of the
homoleptic and heteroleptic antimony ligands Sb<sup><i>i</i></sup>Pr<sub>3</sub>, Sb<sup><i>i</i></sup>Pr<sub>2</sub>Ph, SbMe<sub>2</sub>Ph, and SbMePh<sub>2</sub> with NiI<sub>2</sub> generate rare Ni<sup>II</sup> stibine complexes in either square
planar or trigonal bipyramidal (TBP) geometries, depending on the
steric size of the ligands. Tolman electronic parameters were calculated
(DFT) for each antimony ligand to provide a tabulated resource for
the relative strengths of simple antimony ligands. The electronic
absorbance spectra of the square planar complexes exhibit characteristic
bands [λ<sub>max</sub> ≈ 560 nm (17 900 cm<sup>–1</sup>), ε ≈ 4330 M<sup>–1</sup> cm<sup>–1</sup>] at lower energies compared to the reported phosphine
complexes, indicating the weak donor strength of the stibine ligands
and resultant low-energy ligand field <i>d</i>→<i>d</i> transitions. The square planar complex Ni(I)<sub>2</sub>(Sb<sup><i>i</i></sup>Pr<sub>3</sub>)<sub>2</sub> reacts with CO to form the TBP complex Ni(I)<sub>2</sub>(Sb<sup><i>i</i></sup>Pr<sub>3</sub>)<sub>2</sub>(CO). Lastly,
the complexes were investigated for nickel metal deposition on Si|Cu(100
nm) substrates. The complexes with the strongest donating ligand,
Sb<sup><i>i</i></sup>Pr<sub>3</sub>, deposited the purest
layer of NiCu alloy according to the balanced reaction Ni(I)<sub>2</sub>(Sb<sup>III<i>i</i></sup>Pr<sub>3</sub>)<sub>2</sub> → Ni<sup>0</sup> + Sb<sup>V</sup>(<sup><i>i</i></sup>Pr<sub>3</sub>)I<sub>2</sub>; the iodinated Sb<sup>V</sup> byproduct
was unambiguously detected in the supernatant by <sup>1</sup>H NMR
and mass spectrometry. Complexes with weaker ligands (poor I<sub>2</sub> acceptors/scavengers) resulted undesired deposition of iodine and
CuI on the surface. This work thus serves as a guide for the design
and synthesis of 3<i>d</i> metal complexes with neutral,
heavy main-group donors that are useful for metal deposition applications
Luminescence spectrum in far wings of the resonance line of cesium atoms approaching a sapphire surface
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