Silver-doped graphite oxide composites used as antimicrobial agents against Staphylococcus aureus, Escherichia coli and Tatumella terrea evaluated by direct TLC bioautography

Silver-doped graphite oxide composites presented mixed Ag and Ag _2 O crystalline phases accompanied by C/O and I _D /I _G average ratios of 2.13 and 1.16, associated with a good oxidation degree and high structural disorder or defects in the carbon material, respectively. The low-silver-doped GrO composite showed homogenous silver particle dispersion and a low particle size distribution (96 nm). However, high-silver-doped GrO composites generated materials with high relative crystallinity, silver particle agglomeration, and Ag metal phase promotion. At 3 and 5 mg ml ^−1 per chromatographic plate, the silver-doped graphite oxide composites were tested by direct TLC bioautography against Staphylococcus aureus, Escherichia coli, and Tatumella terrea microorganisms, where the minimum inhibitory concentration was 3 mg ml ^−1 per chromatographic plate. At 3.0 mg ml ^−1 per chromatographic plate, high-silver-doped GrO composites exhibited a 39%, 3.2-fold, and 83% higher retention factor ( R _f ) compared with the composites with low-silver-doped GrO composites against S. aureus, E. coli, and T. terra microorganisms, respectively. However, both composites showed similar inhibition capacities at 5.0 mg ml ^−1 per chromatographic plate against the three microorganisms. This behavior may be associated with both composites reaching the threshold limit. In general, the silver acetate amount used in the silver-doped GrO composites influenced the dispersion, crystalline phase promotion, particle size distribution, and the silver particle release capacity, which modified the electrostatic adsorption type between the composites and the bacterial cell walls

Silica-Copper Oxide Composite Thin Films as Solar Selective Coatings Prepared by Dipping Sol Gel

Silica-copper oxide (silica-CuO) composite thin films were prepared by a dipping sol-gel route using ethanolic solutions comprised TEOS and a copper-propionate complex. Sols with different TEOS/Cu-propionate (Si/Cu) molar ratios were prepared and applied on stainless steel substrates using dipping process. During the annealing process, copper-propionate complexes developed into particulate polycrystalline CuO dispersed in a partially crystallized silica matrix, as indicated by the X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses. The gel thermal analysis revealed that the prepared material might be stable up to 400°C. The silica-CuO/stainless steel system was characterized as a selective absorber surface and its solar selectivity parameters, absorptance (α), and emittance (ε) were evaluated from UV-NIR reflectance data. The solar parameters of such a system were mostly affected by the thickness and phase composition of the SiO2-CuO film. Interestingly, the best solar parameters (α = 0.92 and ε = 0.2) were associated to the thinnest films, which comprised a CuO-Cu2O mixture immersed in the silica matrix, as indicated by XPS

Life cycle, feeding and defecation patterns of Rhodnius ecuadoriensis (Lent & León 1958) (Hemiptera: Reduviidae: Triatominae) under laboratory conditions

Rhodnius ecuadoriensis is the second most important vector of Chagas Disease (CD) in Ecuador. The objective of this study was to describe (and compare) the life cycle, the feeding and defecation patterns under laboratory conditions of two populations of this specie [from the provinces of Manabí (Coastal region) and Loja (Andean region)]. Egg-to-adult (n = 57) development took an average of 189.9 ± 20 (Manabí) and 181.3 ± 6.4 days (Loja). Mortality rates were high among Lojan nymphs. Pre-feeding time (from contact with host to feeding initiation) ranged from 4 min 42 s [nymph I (NI)] to 8 min 30 s (male); feeding time ranged from 14 min 45 s (NI)-28 min 25 s (male) (Manabí) and from 15 min 25 s (NI)-28 min 57 s (nymph V) (Loja). The amount of blood ingested increased significantly with instar and was larger for Manabí specimens (p < 0.001). Defecation while feeding was observed in Manabí specimens from stage nymph III and in Lojan bugs from stage nymph IV. There was a gradual, age-related increase in the frequency of this behaviour in both populations. Our results suggest that R. ecuadoriensis has the bionomic traits of an efficient vector of Trypanosoma cruzi. Together with previous data on the capacity of this species to infest rural households, these results indicate that control of synanthropic R. ecuadoriensis populations in the coastal and Andean regions may have a significant impact for CD control in Ecuador and Northern Peru

Thrombolytic therapy and outcome of patients with an acute symptomatic pulmonary embolism

BACKGROUND: While the primary therapy for most patients with a pulmonary embolism (PE) consists of anticoagulation, the efficacy of thrombolysis relative to standard therapy remains unclear. METHODS: In this retrospective cohort study of 15,944 patients with an objectively confirmed symptomatic acute PE, identified from the multicenter, international, prospective, Registro Informatizado de la Enfermedad TromboEmb\uf3lica (RIETE registry), we aimed to assess the association between thrombolytic therapy and all-cause mortality during the first 3 months after the diagnosis of a PE. After creating two subgroups, stratified by systolic blood pressure (SBP) (< 100 mm Hg vs. other), we used propensity score-matching for a comparison of patients who received thrombolysis to those who did not in each subgroup. RESULTS: Patients who received thrombolysis were younger, had fewer comorbid diseases and more signs of clinical severity compared with those who did not receive it. In the subgroup with systolic hypotension, analysis of propensity score-matched pairs (n = 94 pairs) showed a non-statistically significant but clinically relevant lower risk of death for thrombolysis compared with no thrombolysis (odds ratio [OR] 0.72; 95% confidence interval [CI], 0.36-1.46; P = 0.37). In the normotensive subgroup, analysis of propensity score-matched pairs (n = 217 pairs) showed a statistically significant and clinically meaningful increased risk of death for thrombolysis compared with no thrombolysis (OR 2.32; 95% CI, 1.15-4.68; P = 0.018). When we imputed data for missing values for echocardiography and troponin tests in the group of normotensive patients, we no longer detected the increased risk of death associated with thrombolytic therapy. CONCLUSIONS: In normotensive patients with acute symptomatic PE, thrombolytic therapy is associated with a higher risk of death than no thrombolytic therapy. In hemodynamically unstable patients, thrombolytic therapy is possibly associated with a lower risk of death than no thrombolytic therapy. However, study design limitations do not imply a causal relationship between thrombolytics and outcome

A clinical prognostic model for the identification of low-risk patients with acute symptomatic pulmonary embolism and active cancer.

BACKGROUND: Physicians need a specific risk-stratification tool to facilitate safe and cost-effective approaches to the management of patients with cancer and acute pulmonary embolism (PE). The objective of this study was to develop a simple risk score for predicting 30-day mortality in patients with PE and cancer by using measures readily obtained at the time of PE diagnosis. METHODS: Investigators randomly allocated 1,556 consecutive patients with cancer and acute PE from the international multicenter Registro Informatizado de la Enfermedad TromboEmb\uf3lica to derivation (67%) and internal validation (33%) samples. The external validation cohort for this study consisted of 261 patients with cancer and acute PE. Investigators compared 30-day all-cause mortality and nonfatal adverse medical outcomes across the derivation and two validation samples. RESULTS: In the derivation sample, multivariable analyses produced the risk score, which contained six variables: age > 80 years, heart rate 65 110/min, systolic BP < 100 mm Hg, body weight < 60 kg, recent immobility, and presence of metastases. In the internal validation cohort (n = 508), the 22.2% of patients (113 of 508) classified as low risk by the prognostic model had a 30-day mortality of 4.4% (95% CI, 0.6%-8.2%) compared with 29.9% (95% CI, 25.4%-34.4%) in the high-risk group. In the external validation cohort, the 18% of patients (47 of 261) classified as low risk by the prognostic model had a 30-day mortality of 0%, compared with 19.6% (95% CI, 14.3%-25.0%) in the high-risk group. CONCLUSIONS: The developed clinical prediction rule accurately identifies low-risk patients with cancer and acute PE

Factors Associated with elevated Pulmonary Arterial Pressure Levels on the Echocardiographic Assessment in Patients with Prior Pulmonary Embolism

BACKGROUND: Factors associated with the detection of raised systolic pulmonary artery pressure (sPAP) levels in patients with a prior episode of pulmonary embolism (PE) are not well known. METHODS: We used the RIETE Registry database to identify factors associated with the finding of sPAP levels 6550 mm Hg on trans-thoracic echocardiography, in 557 patients with a prior episode of acute, symptomatic PE. RESULTS: Sixty-two patients (11.1%; 95% CI: 8.72-14.1) had sPAP levels 6550 mm Hg. These patients were more likely women, older, and more likely had chronic lung disease, heart failure, renal insufficiency or leg varicosities than those with PAP levels <50mm Hg. During the index PE event, they more likely had recent immobility, and more likely presented with hypoxemia, increased sPAP levels, atrial fibrillation, or right bundle branch block. On multivariate analysis, women aged 6570 years (hazard ratio [HR]: 2.0; 95% CI: 1.0-3.7), chronic heart or chronic lung disease (HR: 2.4; 95% CI: 1.3-4.4), atrial fibrillation at PE presentation (HR: 2.8; 95% CI: 1.3-6.1) or varicose veins (HR: 1.8; 95% CI: 1.0-3.3) were all associated with an increased risk to have raised sPAP levels. Chronic heart disease, varicose veins, and atrial fibrillation were independent predictors in women, while chronic heart disease, atrial fibrillation, a right bundle branch block or an S1Q3T3 pattern on the electrocardiogram were independent predictors in men. CONCLUSIONS: Women aged 6570 years more likely had raised sPAP levels than men after a PE episode. Additional variables influencing this risk seem to differ according to gender

Influence of recent immobilization and recent surgery on mortality in patients with pulmonary embolism

BACKGROUND: The influence of recent immobilization or surgery on mortality in patients with pulmonary embolism (PE) is not well known. METHODS: We used the Registro Informatizado de Enfermedad TromboEmb\uf3lica (RIETE) data to compare the 3-month mortality rate in patients with PE, with patients categorized according to the presence of recent immobilization, recent surgery, or neither. RESULTS: Of 18,028 patients with PE, 4169 (23%) had recent immobilization, 2212 (12%) had recent surgery, and 11,647 (65%) had neither. The all-cause mortality was 10.0% (95% confidence interval [CI] 9.5-10.4), and the PE-related mortality was 2.6% (95% CI 2.4-2.9). One in every two patients who died from PE had recent immobilization (43%) or recent surgery (6.7%). Only 25% of patients with immobilization had received prophylaxis, as compared with 65% of the surgical patients. Fatal PE was more common in patients with recent immobilization (4.9%; 95% CI 4.3-5.6) than in those with surgery (1.4%; 95% CI 1.0-2.0) or those with neither (2.1%; 95% CI 1.8-2.3). On multivariate analysis, patients with immobilization were at increased risk for fatal PE (odds ratio 2.2; 95% CI 1.8-2.7), with no differences being seen between patients immobilized in hospital or in the community. CONCLUSIONS: Forty-three per cent of patients dying from PE had recent immobilization for 654 days. Many of these deaths could have been prevented

Silent pulmonary embolism in patients with proximal deep vein thrombosis in the lower limbs

BACKGROUND: One in every three patients with deep vein thrombosis (DVT) in the lower limbs may have silent pulmonary embolism (PE), but its clinical relevance has not been thoroughly studied. METHODS: We used the RIETE Registry data to study patients with proximal DVT and no PE symptoms, but with a systematic search for PE. We compared the outcome of DVT patients with silent PE and those with no PE. RESULTS: Of 2375 patients with DVT, 842 (35%) had silent PE and 1533 had no PE. During the first 15 days of anticoagulation, patients presenting with silent PE had a higher incidence of symptomatic PE events than those with no PE (0.95% vs. 0.13%; P = 0.015), with a similar incidence of major bleeding (0.95% vs. 1.63%; P = 0.09). In patients with silent PE, the incidence of PE events during the first 15 days was equal to the incidence of major bleeding (eight events each), but in those with no PE the incidence of PE events was eight times lower (3 vs. 25 bleeding events). Multivariate analysis confirmed that DVT patients with silent PE had a higher incidence of symptomatic PE events during the first 15 days than those with no PE (odds ratio, 4.80; 95% CI, 1.27-18.1), with no differences in bleeding. CONCLUSIONS: DVT patients with silent PE at baseline had an increased incidence of symptomatic PE events during the first 15 days of anticoagulant therapy. This effect disappeared after 3 months of anticoagulation

Clinical presentation and outcome of venous thromboembolism in COPD

Chronic obstructive pulmonary disease (COPD) is a moderate risk factor for venous thromboembolism (VTE), but neither the clinical presentation nor the outcome of VTE in COPD patients is well known. The clinical presentation of VTE, namely pulmonary embolism (PE) or deep venous thrombosis (DVT), and the outcome at 3 months (death, recurrent VTE or bleeding) were compared between 2,984 COPD patients and 25,936 non-COPD patients included in the RIETE (Registro Informatizado de la Enfermedad TromboEmb\uf3lica) registry. This ongoing international, multi-centre registry includes patients with proven symptomatic PE or DVT. PE was the more frequent VTE presentation in COPD patients (n = 1,761, 59%). PE presentation was more significantly associated with COPD patients than non-COPD patients (OR 1.64, 95% CI 1.49-1.80). During the 3-month follow-up, mortality (10.8% versus 7.6%), minor bleeding (4.5% versus 2.3%) or first VTE recurrences as PE (1.5% versus 1.1%) were significantly higher in COPD patients than in non-COPD patients. PE was the most common cause of death. COPD patients presented more frequently with PE than DVT. It may explain the worse prognosis of COPD patients, with a higher risk of death, bleeding or VTE recurrences as PE compared with non-COPD patients. Further therapeutic options are needed