RESUMO
Rechargeable aqueous Zn - MnOx batteries show great potential for grid - scale storage due to cost - effectiveness and high safety. However, most of MnOx cathodes suffer from irreversible phase transformation into spinel ZnMn2O4 with reduced electrochemical activity after repeated charge/discharge cycles, leading to severe capacity decay. Herein, we reveal a strategic design utilizing glucose as the mediating agent to prepare nanostructured MnO/Mn3O4 material, which can be then transformed into lattice - expanded ZnxMn2O4 nanoparticles by electrochemical activation. The expanded structure of ZnxMn2O4 allows better accommodation of Zn2+ and H+ ions and undergoes reversible lattice expansion/contraction during charge/discharge process. Therefore, the lattice - expanded ZnxMn2O4 retains 121 mAh g-1 after 2000 cycles at 1 A g-1, exhibiting stable cycle performance in comparison with the parent MnO2 (63 mAh g-1) and well - crystalline ZnMn2O4 (58 mAh g-1). Moreover, through the comparison of MnO/Mn3O4, Mn3O4/MnO2, and pure Mn3O4 samples, MnO is found to play an important role in forming lattice - expanded spinel structure during the activation process.
Assuntos
Compostos de Manganês , Óxidos , Óxido de Alumínio , Glucose , Íons/química , Óxido de Magnésio , Compostos de Manganês/química , Óxidos/química , ZincoRESUMO
Fatigue is a common complaint in older people. Laboratory-induced muscle fatigue has been found to affect physical functions in older populations but these protocols are rigorous and are unlikely to accurately reflect daily activities. This study used an ecological approach to determine the effects of a busy day on self-reported fatigue and fall-related measures of physical and cognitive function in older people. Fifty community-dwelling adult volunteers, aged 60-88 (mean 73) years participated in this randomised crossover trial. Participants undertook assessments of balance, strength, gait, mobility, cognitive function and self-reported fatigue, before and after a planned rest day and a planned busy day (randomly allocated) at least one week apart. Participants wore an activity monitor on both the rest and busy days. On average, participants undertook twice as many steps and 2.5 times more minutes of activity on the busy, compared with the rest day. Participants had a significant increase in self-reported fatigue on the afternoon of the busy day and no change on the rest day. Repeated measures ANOVAs found no significant day (rest/busy)â¯×â¯time (am/pm) interaction effects, except for the timed up and go test of mobility, resulting from relatively improved mobility performance over the rest day, compared with the busy day. This study showed few effects of a busy day on physical and cognitive performance tests associated with falls in older people.
Assuntos
Acidentes por Quedas/estatística & dados numéricos , Fadiga , Marcha/fisiologia , Idoso , Idoso de 80 Anos ou mais , Austrália , Cognição , Estudos Cross-Over , Avaliação Momentânea Ecológica , Feminino , Humanos , Vida Independente , Masculino , Pessoa de Meia-Idade , Desempenho Físico Funcional , Equilíbrio Postural/fisiologia , Medição de Risco , Autorrelato , Método Simples-CegoRESUMO
Percutaneous coronary intervention (PCI) of unprotected left main disease (ULM) with drug-eluting stents (DES) is hampered by lack of information on long-term (≥10 years) safety data. All patients treated with PCI on ULM in 9 international centers with at least 10 years follow-up were enrolled. Baseline and procedural features were recorded. Repeat PCI (re-PCI) on ULM at 10 years was the primary end point. Secondary end points included major adverse cardiac events and its components (cardiac and noncardiac death, myocardial infarction, re-PCI not on ULM, and stent thrombosis). Sensitivity analysis was performed according to the presence of isolated ULM disease: 284 patients were enrolled. A total of 70 patients (21%) performed a re-PCI on ULM, 39 in the first year, and 31 between 1 and 10 years (only 5 overall performed for acute coronary syndrome). Patients with re-PCI on ULM did not show differences in baseline and procedural features, or experience higher rates of cardiovascular death (12% vs 11%, p 0.65), myocardial infarction (11% vs 6%, p 0.56), or of re-PCI on non-ULM disease (31% vs 27%, p 0.76) compared with those without re-PCI on ULM. At Kaplan-Meier analysis, patients with PCI in other coronary vessels were at higher risk of major adverse cardiac events, driven by target vessel revascularization (20.4% vs 32.9%, p 0.009), as confirmed at multivariate analysis (stenosis other than LM; hazard ratio 2, 1.4 to 2.7, all CI 95%). In conclusion, despite of using first-generation stents, PCI on ULM is safe, with low rates of recurrent events due to index revascularization. Progression of atherosclerotic lesions on other coronary vessels represents the only independent predictive factor for prognosis.
Assuntos
Estenose Coronária/terapia , Stents Farmacológicos , Intervenção Coronária Percutânea , Idoso , Estenose Coronária/complicações , Estenose Coronária/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo , Resultado do TratamentoRESUMO
AIMS: There is uncertainty on which stenting approach confers the best long-term outlook for unprotected left main (ULM) bifurcation disease. METHODS AND RESULTS: This is a non-randomized, retrospective study including all consecutive patients with 50% stenosis of the left main involving at least 1 of the arteries stemming from the left main treated with drug-eluting stents (DES) in 9 European centers between 2002 and 2004. Patients were divided into two groups: those treated with provisional stentings vs. those treated with two stent strategy. The outcomes of interest were 10-year rates of target lesion revascularization (TLR), major adverse cardiac events (MACE), and their components (cardiovascular death, myocardial infarction [MI], or repeat revascularization), along with stent thrombosis (ST). A total of 285 patients were included, 178 (62.5%) in the provisional stenting group and 87 (37.5%) in the two stent group. After 10 years, no differences in TLR were found at unadjusted analysis (19% vs 25%, p>0.05) nor after propensity score matching (25% vs 28%, p>0.05). Similar rates of MACE (60% vs 66%, p>0.05), death (34% vs 43%, p>0.05), MI (9% vs 14%, p>0.05) and ST were also disclosed at propensity-based analysis. CONCLUSION: Even after 10 year follow-up, patients treated with provisional stenting on left main showed comparable rates of target lesion revascularization compared to two stent strategy.
Assuntos
Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/terapia , Stents Farmacológicos/tendências , Pontuação de Propensão , Idoso , Estudos de Coortes , Doença da Artéria Coronariana/mortalidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Fatores de Tempo , Resultado do TratamentoRESUMO
A 53-year-old man, who was a heavy smoker, presented with recent severe cough. Radiography demonstrated a large pulmonary mass in the right upper lung. FDG PET/CT demonstrated heterogeneous high-grade activity in the pulmonary mass located in the right upper lung (standardized uptake value of 20), with central necrosis, bilateral upper mediastinal lymphadenopathy, right supraclavicular lymphadenopathy, direct left sternal manubrium invasion, and distal bilateral peripheral lung metastasis. Histology revealed significant malignant cytologic features and CD1a- and S-100-positive cells by immunohistochemistry staining, typical for Langerhans cell sarcoma.
Assuntos
Fluordesoxiglucose F18 , Sarcoma de Células de Langerhans/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Humanos , Sarcoma de Células de Langerhans/patologia , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Imagem Corporal TotalRESUMO
Eradication of Staphylococcus aureus biofilms after rifampin treatment was tested in a mouse model of device-related infection by using biophotonic imaging. Following treatment, the bioluminescent signals decreased to undetectable levels, irrespective of the age of the biofilm. After the final treatment, the signals rebounded in a time-dependent manner and reached those for the untreated mice. Readministration of rifampin was unsuccessful in eradicating reestablished infections, with the rifampin MICs for such bacteria being increased and with the bacteria having point mutations in the rpoB gene.
Assuntos
Biofilmes/efeitos dos fármacos , Diagnóstico por Imagem , Infecções Estafilocócicas/microbiologia , Animais , Antibióticos Antituberculose/farmacologia , Contagem de Colônia Microbiana , RNA Polimerases Dirigidas por DNA/genética , Medições Luminescentes , Camundongos , Rifampina/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genéticaRESUMO
We have developed a rapid, continuous method for monitoring the effectiveness of several antibacterial agents in real time, noninvasively, by using a recently described mouse model of chronic biofilm infection (J. L. Kadurugamuwa et al., Infect. Immun. 71:882-890, 2003), which relies on biophotonic imaging of bioluminescent bacteria. To facilitate real-time monitoring of infection, we used a Staphylococcus aureus isolate that was made bioluminescent by inserting a modified lux operon into the bacterial chromosome. This bioluminescent reporter bacterium was used to study the antimicrobial effects of several antibiotics belonging to different molecular families. Treatment with rifampin, tobramycin, and ciprofloxacin was started 7 days after subcutaneous implantation of catheters precolonized with 10(4) CFU of S. aureus. Three different doses of antibiotics were administered twice a day for 4 consecutive days. The number of metabolically active bacteria in untreated mice and the tobramycin- and ciprofloxacin-treated groups remained relatively unchanged over the 4-week observation period, indicating poor efficacies for tobramycin and ciprofloxacin. A rapid dose-dependent decline in metabolic activity in rifampin-treated groups was observed, with almost a 90% reduction after two doses and nearly undetectable levels after three doses. The disappearance of light emission correlated with colony counts. After the final treatment, cell numbers rebounded as a function of concentration in a time-dependent manner. The staphylococci isolated from the catheters of mice treated with rifampin were uniformly resistant to rifampin but retained their in vitro susceptibilities to tobramycin and ciprofloxacin. Since the metabolic activities of viable cells and a postantibiotic effect could be detected directly on the support matrix nondestructively and noninvasively, the methodology is specifically appealing for investigating the effects of antibiotics on biofilms in vivo. Moreover, our study points to the possible use of biophotonic imaging for the detection of the development of resistance to therapeutic agents during treatment of chronic infections in vivo.
Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Medições Luminescentes , Animais , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/microbiologia , Biofilmes/crescimento & desenvolvimento , Cateterismo/efeitos adversos , Ciprofloxacina/farmacologia , Contagem de Colônia Microbiana , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Monitoramento de Medicamentos/métodos , Camundongos , Rifampina/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Staphylococcus aureus/crescimento & desenvolvimento , Tobramicina/farmacologiaRESUMO
We have developed a rapid, continuous method for real-time monitoring of biofilms, both in vitro and in a mouse infection model, through noninvasive imaging of bioluminescent bacteria colonized on Teflon catheters. Two important biofilm-forming bacterial pathogens, Staphylococcus aureus and Pseudomonas aeruginosa, were made bioluminescent by insertion of a complete lux operon. These bacteria produced significant bioluminescent signals for both in vitro studies and the development of an in vivo model, allowing effective real-time assessment of the physiological state of the biofilms. In vitro viable counts and light output were parallel and highly correlated (S. aureus r = 0.98; P. aeruginosa r = 0.99) and could be maintained for 10 days or longer, provided that growth medium was replenished every 12 h. In the murine model, subcutaneous implantation of the catheters (precolonized or postimplant infected) was well tolerated. An infecting dose of 10 (3) to 10 (5) CFU/catheter for S. aureus and P. aeruginosa resulted in a reproducible, localized infection surrounding the catheter that persisted until the termination of the experiment on day 20. Recovery of the bacteria from the catheters of infected animals showed that the bioluminescent signal corresponded to the CFU and that the lux constructs were highly stable even after many days in vivo. Since the metabolic activity of viable cells could be detected directly on the support matrix, nondestructively, and noninvasively, this method is especially appealing for the study of chronic biofilm infections and drug efficacy studies in vivo.