77 research outputs found
Conjugated dendrimers: A modular approach to materials for full colour displays
Conjugated dendrimers provide an excellent molecular architecture for tuning material properties for organic light emitting diodes. Here we demonstrate a modular approach allowing highly efficient fluorescent and phosphorescent emissive chromophores to be used to make red, green and blue solution-processed light emitting diodes. The choice of a common dendritic architecture ensures good solubility and film forming properties irrespective of the choice of core unit. In addition, this architecture allows blending of dendrimers with different cores without phase separation. We show that blending provides a simple but powerful way of tuning the colour of dendrimer LEDs from deep blue to blue-green, and from green to red with little impact on the device properties
Multihospital Outbreak of Clostridium difficile Infection, Cleveland, Ohio, USA
To determine whether a multihospital Clostridium difficile outbreak was associated with epidemic strains and whether use of particular fluoroquinolones was associated with increased infection rates, we cultured feces from C. difficile–infected patients. Use of fluoroquionolones with enhanced antianaerobic activity was not associated with increased infection rates
U.S. Physician-Scientist Workforce in the 21st Century: Recommendations to Attract and Sustain the Pipeline
The U.S. physician-scientist (PS) workforce is invaluable to the nation's biomedical research effort. It is through biomedical research that certain diseases have been eliminated, cures for others have been discovered, and medical procedures and therapies that save lives have been developed. Yet, the U.S. PS workforce has both declined and aged over the last several years. The resulting decreased inflow and outflow to the PS pipeline renders the system vulnerable to collapsing suddenly as the senior workforce retires. In November 2015, the Alliance for Academic Internal Medicine hosted a consensus conference on the PS workforce to address issues impacting academic medical schools, with input from early-career PSs based on their individual experiences and concerns. One of the goals of the conference was to identify current impediments in attracting and supporting PSs and to develop a new set of recommendations for sustaining the PS workforce in 2016 and beyond. This Perspective reports on the opportunities and factors identified at the conference and presents five recommendations designed to increase entry into the PS pipeline and nine recommendations designed to decrease attrition from the PS workflow
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Labral Reconstruction with Iliotibial Band Autograft and Semitendinosus Allograft Improves Hip Joint Contact Area and Contact Pressure: An In-Vitro Analysis
Objectives: Labral reconstruction using iliotibial band (ITB) autograft and semitendinosus (Semi-T) allograft have recently been described in cases of labral deficiency. The current study seeks to understand the biomechanical effects of an intact labrum, segmental labral resection, and labral reconstruction on joint contact area, contact pressure, and peak force. Methods: Ten fresh-frozen human cadaver hips were analyzed utilizing thin-film piezoresistive load sensors to measure contact area, contact pressure, and peak force 1) with the native intact labrum, 2) after segmental labral resection and 3) after graft labral reconstruction with either ITB autograft or Semi-T allograft. Each specimen was examined at 20° extension and 60° flexion. Statistical analysis was conducted through one-way ANOVA with post-hoc Games-Howell tests. Results: For the ITB group, labral resection significantly decreased contact area (20°: 73.2%±5.38, P=0.0010; 60°: 78.5%±6.93, P=0.0063) and increased contact pressures (20°: 106.7%±4.15, P=0.0387; 60°: 103.9%±1.15, P=0.0428). ITB reconstruction improved contact area (20°: 87.2%±12.3, P=0.0130; 60°: 90.5%±8.81, P=0.0079) and contact pressures (20°: 98.5%±5.71, P=0.0476; 60°: 96.6%±1.13, P=0.0056) from the resected state. Contact pressure at 60° flexion was significantly lower compared to the native labrum (P = 0.0420). For the Semi-T group, labral resection significantly decreased contact area (20°: 68.1±12.57, P=0.0002; 60°: 67.5%±6.70, P=0.0002) and increased contact pressures (20°: 105.3%±3.73, P=0.0304; 60°: 106.8%±4.04, P=0.0231). Semi-T reconstruction improved contact area (20°: 87.9%±7.95, P=0.0087; 60°: 92.9%±13.2, P=0.0014) and contact pressures (20°: 97.1%±3.18, P=0.0017; 60°: 97.4%±4.39, P=0.0027) from the resected state. Comparative analysis demonstrated no statistically significant differences between either graft reconstruction in relation to contact area, contact pressure, or peak forces. (Figure 1). Conclusion: Segmental anterosuperior labral resection results in significantly decreased contact area and increased contact pressures, while labral reconstruction partially restores time-zero acetabular contact areas and pressures as compared to the resected state. Although labral reconstruction improved the measured biomechanical properties as compared to the resected state, some of these properties remained significantly different compared to the native intact labrum
HIV-1 protease inhibitors and clinical malaria: A secondary analysis of the AIDS Clinical Trials Group A5208 study
HIV-1 protease inhibitors (PIs) have antimalarial activity in vitro and in murine models. The potential beneficial effect of HIV-1 PIs on malaria has not been studied in clinical settings. We used data from Adult AIDS Clinical Trials Group A5208 sites where malaria is endemic to compare the incidence of clinically diagnosed malaria among HIV-infected adult women randomized to either lopinavir/ritonavir (LPV/r)-based antiretroviral therapy (ART) or to nevirapine (NVP)-based ART. We calculated hazard ratios and 95% confidence intervals. We conducted a recurrent events analysis that included both first and second clinical malarial episodes and also conducted analyses to assess the sensitivity of results to outcome misclassification. Among the 445 women in this analysis, 137 (31%) received a clinical diagnosis of malaria at least once during follow-up. Of these 137, 72 (53%) were randomized to LPV/r-based ART. Assignment to the LPV/r treatment group (n = 226) was not consistent with a large decrease in the hazard of first clinical malarial episode (hazard ratio = 1.11 [0.79 to 1.56]). The results were similar in the recurrent events analysis. Sensitivity analyses indicated the results were robust to reasonable levels of outcome misclassification. In this study, the treatment with LPV/r compared to NVP had no apparent beneficial effect on the incidence of clinical malaria among HIV-infected adult women. Additional research concerning the effects of PI-based therapy on the incidence of malaria diagnosed by more specific criteria and among groups at a higher risk for severe disease is warranted. Copyrigh
Global Epidemiology and Clinical Outcomes of Carbapenem-Resistant Pseudomonas aeruginosa and Associated Carbapenemases (POP): A Prospective Cohort Study
BACKGROUND: Carbapenem-resistant Pseudomonas aeruginosa (CRPA) is a global threat, but the distribution and clinical significance of carbapenemases are unclear. The aim of this study was to define characteristics and outcomes of CRPA infections and the global frequency and clinical impact of carbapenemases harboured by CRPA.
METHODS: We conducted an observational, prospective cohort study of CRPA isolated from bloodstream, respiratory, urine, or wound cultures of patients at 44 hospitals (10 countries) between Dec 1, 2018, and Nov 30, 2019. Clinical data were abstracted from health records and CRPA isolates were whole-genome sequenced. The primary outcome was 30-day mortality from the day the index culture was collected. We compared outcomes of patients with CRPA infections by infection type and across geographic regions and performed an inverse probability weighted analysis to assess the association between carbapenemase production and 30-day mortality.
FINDINGS: We enrolled 972 patients (USA n=527, China n=171, south and central America n=127, Middle East n=91, Australia and Singapore n=56), of whom 581 (60%) had CRPA infections. 30-day mortality differed by infection type (bloodstream 21 [30%] of 69, respiratory 69 [19%] of 358, wound nine [14%] of 66, urine six [7%] of 88; p=0·0012) and geographical region (Middle East 15 [29%] of 52, south and central America 20 [27%] of 73, USA 60 [19%] of 308, Australia and Singapore three [11%] of 28, China seven [6%] of 120; p=0·0002). Prevalence of carbapenemase genes among CRPA isolates also varied by region (south and central America 88 [69%] of 127, Australia and Singapore 32 [57%] of 56, China 54 [32%] of 171, Middle East 27 [30%] of 91, USA ten [2%] of 527; p
INTERPRETATION: The emergence of different carbapenemases among CRPA isolates in different geographical regions and the increased mortality associated with carbapenemase-producing CRPA infections highlight the therapeutic challenges posed by these organisms.
FUNDING: National Institutes of Health
Global epidemiology and clinical outcomes of carbapenem-resistant Pseudomonas aeruginosa and associated carbapenemases (POP): a prospective cohort study
BACKGROUND: Carbapenem-resistant Pseudomonas aeruginosa (CRPA) is a global threat, but the distribution and clinical significance of carbapenemases are unclear. The aim of this study was to define characteristics and outcomes of CRPA infections and the global frequency and clinical impact of carbapenemases harboured by CRPA.
METHODS: We conducted an observational, prospective cohort study of CRPA isolated from bloodstream, respiratory, urine, or wound cultures of patients at 44 hospitals (10 countries) between Dec 1, 2018, and Nov 30, 2019. Clinical data were abstracted from health records and CRPA isolates were whole-genome sequenced. The primary outcome was 30-day mortality from the day the index culture was collected. We compared outcomes of patients with CRPA infections by infection type and across geographic regions and performed an inverse probability weighted analysis to assess the association between carbapenemase production and 30-day mortality.
FINDINGS: We enrolled 972 patients (USA n=527, China n=171, south and central America n=127, Middle East n=91, Australia and Singapore n=56), of whom 581 (60%) had CRPA infections. 30-day mortality differed by infection type (bloodstream 21 [30%] of 69, respiratory 69 [19%] of 358, wound nine [14%] of 66, urine six [7%] of 88; p=0·0012) and geographical region (Middle East 15 [29%] of 52, south and central America 20 [27%] of 73, USA 60 [19%] of 308, Australia and Singapore three [11%] of 28, China seven [6%] of 120; p=0·0002). Prevalence of carbapenemase genes among CRPA isolates also varied by region (south and central America 88 [69%] of 127, Australia and Singapore 32 [57%] of 56, China 54 [32%] of 171, Middle East 27 [30%] of 91, USA ten [2%] of 527; p\u3c0·0001). KPC-2 (n=103 [49%]) and VIM-2 (n=75 [36%]) were the most common carbapenemases in 211 carbapenemase-producing isolates. After excluding USA patients, because few US isolates had carbapenemases, patients with carbapenemase-producing CRPA infections had higher 30-day mortality than those with non-carbapenemase-producing CRPA infections in both unadjusted (26 [22%] of 120 vs 19 [12%] of 153; difference 9%, 95% CI 3-16) and adjusted (difference 7%, 95% CI 1-14) analyses.
INTERPRETATION: The emergence of different carbapenemases among CRPA isolates in different geographical regions and the increased mortality associated with carbapenemase-producing CRPA infections highlight the therapeutic challenges posed by these organisms.
FUNDING: National Institutes of Health
Epidemiología mundial y resultados clínicos de Pseudomonas aeruginosa resistente a carbapenemes y carbapenemasas asociadas (POP): un estudio prospectivo de cohortes
Antecedentes: La Pseudomonas aeruginosa resistente a los carbapenemes (CRPA) es una amenaza mundial, pero la distribución y la importancia clínica de las carbapenemasas no están claras. El objetivo de este estudio fue definir las características y los resultados de las infecciones por CRPA, así como la frecuencia global y el impacto clínico de las carbapenemasas albergadas por CRPA. Métodos: Llevamos a cabo un estudio de cohortes observacional y prospectivo de CRPA aislados de cultivos de torrente sanguíneo, respiratorio, orina o heridas de pacientes en 44 hospitales (10 países) entre el 1 de diciembre de 2018 y el 30 de noviembre de 2019. Los datos clínicos se extrajeron de los registros de salud y los aislados de CRPA se secuenciaron en todo el genoma. El resultado primario fue la mortalidad a 30 días a partir del día en que se recolectó el cultivo índice. Se compararon los resultados de los pacientes con infecciones por CRPA por tipo de infección y entre regiones geográficas y se realizó un análisis ponderado de probabilidad inversa para evaluar la asociación entre la producción de carbapenemasas y la mortalidad a 30 días. Resultados: Se incluyeron 972 pacientes (EE.UU. n=527, China n=171, América del Sur y Central n=127, Oriente Medio n=91, Australia y Singapur n=56), de los cuales 581 (60%) tenían infecciones por CRPA. La mortalidad a los 30 días difería según el tipo de infección (torrente sanguíneo 21 [30%] de 69, respiratoria 69 [19%] de 358, herida nueve [14%] de 66, orina seis [7%] de 88; p=0-0012) y la región geográfica (Oriente Medio 15 [29%] de 52, América del Sur y Central 20 [27%] de 73, EE.UU. 60 [19%] de 308, Australia y Singapur tres [11%] de 28, China siete [6%] de 120; p=0-0002). La prevalencia de genes carbapenemasa entre los aislados CRPA también varió según la región (América del Sur y Central 88 [69%] de 127, Australia y Singapur 32 [57%] de 56, China 54 [32%] de 171, Oriente Medio 27 [30%] de 91, EE.UU. diez [2%] de 527; p<0-0001). KPC-2 (n=103 [49%]) y VIM-2 (n=75 [36%]) fueron las carbapenemasas más comunes en 211 aislados productores de carbapenemasas. Después de excluir a los pacientes de EE.UU., porque pocos aislados de EE.UU. tenían carbapenemasas, los pacientes con infecciones por CRPA productoras de carbapenemasas tuvieron una mayor mortalidad a los 30 días que aquellos con infecciones por CRPA no productoras de carbapenemasas, tanto en los análisis no ajustados (26 [22%] de 120 frente a 19 [12%] de 153; diferencia 9%, IC 95% 3-16) como ajustados (diferencia 7%, IC 95% 1-14). Interpretación: La aparición de diferentes carbapenemasas entre los aislados de CRPA en diferentes regiones geográficas y el aumento de la mortalidad asociada a las infecciones por CRPA productores de carbapenemasas ponen de manifiesto los retos terapéuticos que plantean estos organismos. Financiación: Institutos Nacionales de Salud.Background: Carbapenem-resistant Pseudomonas aeruginosa (CRPA) is a global threat, but the distribution and clinical significance of carbapenemases are unclear. The aim of this study was to define characteristics and outcomes of CRPA infections and the global frequency and clinical impact of carbapenemases harboured by CRPA. Methods: We conducted an observational, prospective cohort study of CRPA isolated from bloodstream, respiratory, urine, or wound cultures of patients at 44 hospitals (10 countries) between Dec 1, 2018, and Nov 30, 2019. Clinical data were abstracted from health records and CRPA isolates were whole-genome sequenced. The primary outcome was 30-day mortality from the day the index culture was collected. We compared outcomes of patients with CRPA infections by infection type and across geographic regions and performed an inverse probability weighted analysis to assess the association between carbapenemase production and 30-day mortality. Findings: We enrolled 972 patients (USA n=527, China n=171, south and central America n=127, Middle East n=91, Australia and Singapore n=56), of whom 581 (60%) had CRPA infections. 30-day mortality differed by infection type (bloodstream 21 [30%] of 69, respiratory 69 [19%] of 358, wound nine [14%] of 66, urine six [7%] of 88; p=0·0012) and geographical region (Middle East 15 [29%] of 52, south and central America 20 [27%] of 73, USA 60 [19%] of 308, Australia and Singapore three [11%] of 28, China seven [6%] of 120; p=0·0002). Prevalence of carbapenemase genes among CRPA isolates also varied by region (south and central America 88 [69%] of 127, Australia and Singapore 32 [57%] of 56, China 54 [32%] of 171, Middle East 27 [30%] of 91, USA ten [2%] of 527; p<0·0001). KPC-2 (n=103 [49%]) and VIM-2 (n=75 [36%]) were the most common carbapenemases in 211 carbapenemase-producing isolates. After excluding USA patients, because few US isolates had carbapenemases, patients with carbapenemase-producing CRPA infections had higher 30-day mortality than those with non-carbapenemase-producing CRPA infections in both unadjusted (26 [22%] of 120 vs 19 [12%] of 153; difference 9%, 95% CI 3–16) and adjusted (difference 7%, 95% CI 1–14) analyses. Interpretation: The emergence of different carbapenemases among CRPA isolates in different geographical regions and the increased mortality associated with carbapenemase-producing CRPA infections highlight the therapeutic challenges posed by these organisms. Funding: National Institutes of Health
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