1,053 research outputs found

    Electronically tuned optical filters

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    Electro-optical effect of light modifying type for electronically controlling colo

    Optimal Duration for Continuation of Statin Therapy in Bacteremic Patients

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    Background: Evidence suggests statins may improve survival in patients with bloodstream infections. However, there is no consensus on optimal timing and duration of exposure. Objectives: To quantify statin therapy duration associated with decreased mortality in bacteremic statin users. Methods: We conducted a case-control study using OptumClinformatics™ with matched Premier hospital data (1 October 2009–31 March 2013). Cases who died during the hospitalization were matched 1:1 to survivors on disease risk scores (DRSs). Post-admission statin therapy duration was evaluated in patients with at least 90 days of pre-admission continuous statin use. Classification and regression tree (CART) analysis was conducted to identify the optimal duration of statin continuation which provided the lowest inpatient mortality. Logistic regression was used to calculate the odds of mortality. Results: We included 58 DRS matched pairs of cases and controls: 47 patients (41%) continued statin therapy during the hospital admission, 15 (32%) cases and 32 (68%) controls. The CART analysis partitioned the continuation of statin therapy at ⩾2 days, representing lower mortality for patients who continued statins for 2 days or more and higher mortality for patients who did not continue or remained on statins for only 1 day. Inpatient mortality was 76% lower among those with at least 2 days of continued statin use (odds ratio 0.24, 95% confidence interval 0.11–0.55)

    Benthic Nutrient Flux in a Small Estuary in Northwestern Florida (USA)

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    Benthic nutrient fluxes of ammonium (NH4+), nitrite/nitrate (NO2- + NO3-), phosphate (PO4-3), and dissolved silica (DSi) were measured in Escambia Bay, an estuary within the larger Pensacola Bay system of northwestern Florida (USA). Our study occurred during a severe drought which reduced riverine inputs to Escambia Bay. Laboratory incubations of field-collected cores were conducted on 8 dates between June and October 2000 to estimate nutrient flux, and cores were collected from locations exhibiting a range of sediment organic matter content. NH4+ flux ranged from – 48.1 to 110.4 μmol m-2 h-1, but the mean flux was 14.6 μmol m-2 h-1. Dissolved silica (DSi) fluxes were also variable (-109. 3 to 145.3 μmol m-2 h-1), but the mean net flux (9.3 μmol m-2 h-1) was from the sediment to the water column. Bay sediment fluxes for NO2-+ NO3- and PO4-3 were less variable during this period (– 7.93 to 28.73 and – 1.74 to 3.29 μmol m-2 h-1 for NO2-+ NO3- and PO4-3, respectively). Low NH4+ fluxes were similar to published estimates from lagoonal Gulf of Mexico (GOM) estuaries, possibly due to the reduced freshwater input. Diminished regeneration of phosphate relative to inorganic nitrogen observed during the study period was consistent with previous research in Pensacola Bay suggesting phytoplankton phosphorus limitation. Finally, the estimated residence time of Escambia Bay and the mean turnover times for NH4+ and NO2-+ NO3- suggested that benthic flux significantly influenced nitrogen concentrations in overlying water

    Sophomores Reign On!: A Sophomore Student Success Model for Old Dominion University

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    The Division of Student Engagement and Enrollment Services at Old Dominion University (ODU) submitted a Request for Assistance to examine the challenges sophomore students face that can lead to attrition. A doctoral research team conducted an exploratory, sequential, mixed-methods study consisting of a literature review, focus groups and interviews with current ODU juniors and seniors, surveys of current ODU sophomores, staff, and faculty, and interviews with benchmark institutions that have successful sophomore student programming at their schools. The team explained the commonly found needs and barriers that sophomore students face, and specifically examined the expressed sophomore student challenges as revealed by ODU students, staff, and faculty. Findings indicated that there is a lack of transitional support, sophomore student development training, and a defined sophomore student experience at ODU. In response to these findings, the team created a sophomore student success model that recommends developing a sophomore orientation program, training staff and faculty on sophomore needs and development, creating a streamlined mentoring program, evaluating current academic advising models, and designing a Sophomore Year Experience (SYE)

    Pressure Induced Hydration Dynamics of Membranes

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    Pressure-jump initiated time-resolved x-ray diffraction studies of dynamics of the hydration of the hexagonal phase in biological membranes show that (i) the relaxation of the unit cell spacing is non-exponential in time; (ii) the Bragg peaks shift smoothly to their final positions without significant broadening or loss in crystalline order. This suggests that the hydration is not diffusion limited but occurs via a rather homogeneous swelling of the whole lattice, described by power law kinetics with an exponent β=1.3±0.2 \beta = 1.3 \pm 0.2.Comment: REVTEX 3, 10 pages,3 figures(available on request),#

    The Risk of Hepatotoxicity with Fluoroquinolones: A National Case-Control Safety Study

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    Purpose. Fluoroquinolones are generally considered safe and well-tolerated. However, suspected fluoroquinolone induced hepatotoxicity has been increasingly reported, but data are lacking. Thus, the objective of this study was to assess the risk of hepatotoxicity in patients using fluoroquinolones compared to non-users. Methods. National Veterans Affairs (VA) hospital admissions were assessed between January 1, 2002 and December 31, 2008. Our case-control study matched patients with a primary diagnosis of hepatotoxicity (cases) to those with myocardial infarction (controls) on admission date (matched up to 1:6). Conditional logistic regression was used to compute adjusted odds ratios (OR) and 95% confidence intervals (CI) of hepatotoxicity associated with fluoroquinolone exposure. Results. Our study included 7,862 cases and 45,512 matched controls. The majority of study patients were white (63.4%), males (97.7%), with a mean age of 61 years. After adjusting for confounders, fluoroquinolone use was significantly associated with a 20% increased risk of hepatotoxicity development (OR 1.20, 95% CI 1.04-1.38) compared to non-users. A statistically significant increased risk of hepatotoxicity was associated with ciprofloxacin use individually (OR 1.29, 95% CI 1.05-1.58), but not with levofloxacin or moxifloxacin use. Conclusion. The use of fluoroquinolones was associated with an increased risk of hepatotoxicity relative to non-users in our national VA study population

    Evidence to support continuation of statin therapy in patients with Staphylococcus aureus bacteremia

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    In addition to cholesterol-lowering capabilities, statins possess anti-inflammatory and immunomodulatory effects. We sought to quantify the real-world impact of different statin exposure patterns on clinical outcomes in Staphylococcus aureus bacteremia. We conducted a retrospective cohort study among hospitalized patients with positive S. aureus blood cultures receiving appropriate antibiotics within 48 h of culture collection (Veterans Affairs hospitals, 2002 to 2013). Three statin exposure groups were compared to nonusers: pretreated statin users initiating therapy in the 30 days prior to culture and either (i) continuing statin therapy after culture or (ii) not continuing after culture, and (iii) de novo users initiating at culture. Nonusers included patients without statins in the year prior to culture through discharge. Propensity score-matched Cox proportional hazards regression models were developed. We were able to balance significantly different baseline characteristics using propensity score matching for pretreated without continuation (n = 331), pretreated with continuation (n = 141), and de novo (n = 177) statin users compared to nonusers. We observed a significantly lower 30-day mortality rate (hazard ratio [HR], 0.46; 95% confidence interval [CI], 0.25 to 0.84; number needed to treat [NNT], 10) among pretreated and continued statin users, while protective effects were not observed in de novo (HR, 1.04; 95% CI, 0.60 to 1.82; NNT, undefined) or pretreated but not continued (HR, 0.92; 95% CI, 0.64 to 1.32; NNT, 47) users. In our national cohort study among patients with S. aureus bacteremia, continuation of statin therapy among incident statin users was associated with significant beneficial effects on mortality, including a 54% lower 30-day mortality rate

    Spatial and environmental drivers of macrophyte diversity and community composition in temperate and tropical calcareous rivers

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    The hypothesis was examined that sources of variation in macrophyte species richness (alpha-diversity: S) and community composition (“species-set”), attributable to spatial and environmental, variables, may differ in importance between tropical and temperate calcareous rivers (>10 mg CaCO3 L−1). To test this hypothesis geographic, environmental, and aquatic vegetation data was acquired for 1151 sites on calcareous rivers within the British Isles, supporting 106 macrophyte species (mean S: 3.1 species per sample), and 203 sites from Zambian calcareous rivers, supporting 255 macrophyte species (mean S: 8.3 species per sample). The data were analysed using an eigenfunction spatial analysis procedure, Moran’s Eigenvector Maps (MEM), to assess spatial variation of species richness and community composition at large regional scale (>105 km2: British Isles and Zambia); and at medium catchment scale (104–105 km2: British Isles only). Variation-partitioning was undertaken using multiple regression for species richness data, and partial redundancy analysis (pRDA) for community data. For the British Isles, spatial and environmental variables both significantly contributed to explaining variation in both species richness and community composition. In addition, a substantial amount of the variation in community composition, for the British Isles as a whole and for some RBUs, was accounted for by spatially-structured environmental variables. In Zambia, species richness was explained only by pure spatial variables, but environmental and spatially-structured environmental variables also explained a significant part of the variation for community composition. At medium-scale, in the British Isles, species richness was explained by spatial variables, and only for four of the six RBUs

    Clinical and genetic risk factors for biofilm-forming Staphylococcus aureus

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    The molecular and clinical factors associated with biofilm-forming methicillin-resistant Staphylococcus aureus (MRSA) are incompletely understood. Biofilm production for 182 MRSA isolates obtained from clinical culture sites (2004 to 2013) was quantified. Microbiological toxins, pigmentation, and genotypes were evaluated, and patient demographics were collected. Logistic regression was used to quantify the effect of strong biofilm production (versus weak biofilm production) on clinical outcomes and independent predictors of a strong biofilm. Of the isolates evaluated, 25.8% (47/182) produced strong biofilms and 40.7% (74/182) produced weak biofilms. Strong biofilm-producing isolates were more likely to be from multilocus sequence typing (MLST) clonal complex 8 (CC8) (34.0% versus 14.9%; P = 0.01) but less likely to be from MLST CC5 (48.9% versus 73.0%; P = 0.007). Predictors for strong biofilms were spa type t008 (adjusted odds ratio [aOR], 4.54; 95% confidence interval [CI], 1.21 to 17.1) and receipt of chemotherapy or immunosuppressants in the previous 90 days (aOR, 33.6; 95% CI, 1.68 to 673). Conversely, patients with high serum creatinine concentrations (aOR, 0.33; 95% CI, 0.15 to 0.72) or who previously received vancomycin (aOR, 0.03; 95% CI, 0.002 to 0.39) were less likely to harbor strong biofilm-producing MRSA. Beta-toxin-producing isolates (aOR, 0.31; 95% CI, 0.11 to 0.89) and isolates with spa type t895 (aOR, 0.02 95% CI

    Tissue-specific expression of high-voltage-activated dihydropyridine-sensitive L-type calcium channels

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    The cloning of the cDNA for the α1 subunit of L-type calcium channels revealed that at least two genes (CaCh1 and CaCh2) exist which give rise to several splice variants. The expression of mRNA for these α1 subunits and the skeletal muscle α2/δ, β and γ subunits was studied in rabbit tissues and BC3H1 cells. Nucleic-acid-hybridization studies showed that the mRNA of all subunits are expressed in skeletal muscle, brain, heart and aorta. However, the α1-, β- and γ-specific transcripts had different sizes in these tissues. Smooth muscle and heart contain different splice variants of the CaCh2 gene. The α1, β and γ mRNA are expressed together in differentiated but not in proliferating BC3H1 cells. A probe specific for the skeletal muscle α2/δ subunit did not hybridize to poly(A)-rich RNA from BC3H1 cells. These results suggest that different splice variants of the genes for the α1, β and γ subunits exist in tissues containing L-type calcium channels, and that their expression is regulated in a coordinate manner
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