The presence of antibiotics and their metabolites in natural waters has raised some concern among scientists around the world because it can lead to bacterial resistance and other unknown ...consequences to mankind and wildlife. Persulfate (PS)-driven oxidation is a new technology that has been used successfully to remediate contaminated sites, but its use to treat wastewater, especially sewage treatment plant (STP) effluent, is still scarce. This paper describes the effect of several persulfate activation methods for degrading sulfathiazole (STZ) in Milli-Q water and in STP effluent. Some parameters, such as pH, persulfate concentration, presence of Mn
2+
, Zn
2+
, Cu
2+
, Fe
2+
, and Fe
3+
, as well as copper and iron organic complexes, were studied in STZ degradation. Raising the pH from 5 to 9, as well as the persulfate concentration, resulted in increased STZ degradation. Among the transition metals evaluated, only Fe
2+
and Cu
2+
were able to activate persulfate molecules. Copper was a better activator than iron since its effect lasts longer. Citrate was the best ligand evaluated increasing Fe(II) activation capacity at pH 7. Hydroxylamine addition to Fe(II) on persulfate system extended the Fe(II) effect. The presence of bicarbonate or humic acid did not affect PS-driven degradation of STZ. Finally, the degradation of STZ in STP effluent promoted by PS-driven oxidation (25 °C) was as fast as in Milli-Q water, proving to be successful.
The ability to integrate echocardiographic for rheumatic heart disease (RHD) into RHD prevention programs is limited because of lack of financial and expert human resources in endemic areas. Task ...shifting to nonexperts is promising; but investigations into workforce composition and training schemes are needed. The objective of this study was to test nonexperts' ability to interpret RHD screening echocardiograms after a brief, standardized, computer-based training course. Six nonexperts completed a 3-week curriculum on image interpretation. Participant performance was tested in a school-screening environment in comparison to the reference approach (cardiologists, standard portable echocardiography machines, and 2012 World Heart Federation criteria). All participants successfully completed the curriculum, and feedback was universally positive. Screening was performed in 1,381 children (5 to 18 years, 60% female), with 397 (47 borderline RHD, 6 definite RHD, 336 normal, and 8 other) referred for handheld echo. Overall sensitivity of the simplified approach was 83% (95% CI 76% to 89%), with an overall specificity of 85% (95% CI 82% to 87%). The most common reasons for false-negative screens (n = 16) were missed mitral regurgitation (MR; 44%) and MR ≤1.5 cm (29%). The most common reasons for false-positive screens (n = 179) included identification of erroneous color jets (25%), incorrect MR measurement (24%), and appropriate application of simplified guidelines (39.4%). In conclusion, a short, independent computer-based curriculum can be successfully used to train a heterogeneous group of nonexperts to interpret RHD screening echocardiograms. This approach helps address prohibitive financial and workforce barriers to widespread RHD screening.
Linear algebra operations on private distributed data are frequently required in several practical scenarios (e.g., statistical analysis and privacy preserving databases). We present universally ...composable two-party protocols to compute inner products, determinants, eigenvalues, and eigenvectors. These protocols are built for a two-party scenario where the inputs are provided by mutually distrustful parties. After execution, the protocols yield the results of the intended operation while preserving the privacy of their inputs. Universal composability is obtained in the trusted initializer model, ensuring information theoretical security under arbitrary protocol composition in complex environments. Furthermore, our protocols are computationally efficient since they only require field multiplication and addition operations.
Information-theoretically secure string oblivious transfer (OT) can be constructed based on discrete memoryless channel (DMC). The oblivious transfer capacity of a channel characterizes - similarly ...to the (standard) information capacity - how efficiently it can be exploited for secure oblivious transfer of strings. The OT capacity of a generalized erasure channel (GEC) - which is a combination of a (general) DMC with the erasure channel - has been established by Ahlswede and Csizar at ISIT'07 in the case of passive adversaries. In this paper, we present the protocol that achieves this capacity against malicious adversaries for GEC with erasure probability at least 1/2. Our construction is based on the protocol of Crepeau and Savvides from Eurocrypt'06 which uses interactive hashing (IH). We solve an open question posed by the above paper, by basing it upon a constant round IH scheme (previously proposed by Ding et al. at TCC'04). As a side result, we show that the Ding et al. IH protocol can deal with transmission errors.
The 2012 World Heart Federation Criteria are the current gold standard for the diagnosis of latent rheumatic heart disease (RHD). Because data and experience using these criteria have grown, there is ...opportunity to simplify and develop outcome prediction tools. We aimed to develop a simple echocardiographic score applicable for RHD screening with potential to predict disease progression.
This study included 3 cohorts used for score derivation (n=9501), score validation (n=7312), and assessment of outcomes prediction (n=227). In the derivation cohort, variables independently associated with definite RHD were assigned point values proportional to their regression coefficients. The sum of these values was stratified into low (0-6), intermediate (7-9), and high (≥10) risk.
Five components were selected for score development, including mitral valve anterior leaflet thickening, excessive leaflet tip motion, and regurgitation jet length ≥2 cm, and aortic valve focal thickening and any regurgitation. The score showed optimal discrimination and calibration for RHD diagnosis in the derivation and validation cohorts (C statistic, 0.998 and 0.994, respectively), with good discrimination for predicting disease progression (C statistic, 0.811). Progression-free survival rate in the low-risk children at 1-, 2-, and 3-year follow-up was 100%, 100%, and 93%, respectively, compared with 90%, 60%, and 47% in high-risk group. The point-based score was strongly associated with disease progression (hazard ratio, 1.270; 95% CI, 1.188-1.358; P<0.001).
This simplified score, based on components of the World Heart Federation criteria, is highly accurate to recognize definite RHD and provides the first tool for risk stratification, assigning children with latent RHD to low, intermediate, or high risk based on echocardiographic features at diagnosis.
Rhodnius prolixus expresses nitric oxide synthase (NOS) in the cytosol of the salivary gland (SG) cells. The NO produced is stored in the SG lumen bound to NO-carrier haemeproteins called ...nitrophorins (NPs). NPs bind tightly to NO in the acidic SG lumen, but release NO when the pH becomes high, e.g., at the host skin (pH~7.4). NO elicits potent and transient relaxation of vascular smooth muscle. Here, we investigated the role of salivary NO in the R. prolixus feeding behaviour and the salivary vasodilator activity of the host microcirculation. NOS knockdown in R. prolixus changed the SG colour, decreased the number of NO-loaded NPs and caused impairment of feeding performance. When salivary gland extracts (SGEs) were obtained from NOS- and NPs-knockdown insects and prepared in pH 5.0 solution and injected (i.v.) into mice via the tail vein, no vasodilation was observed, whereas SGEs from control insects caused long-term venodilation in the mouse skin. SGs disrupted directly in PBS (pH 7.4) containing BSA produced long-term vasodilation compared to the controls without BSA due to the possible formation of nitroso-albumin, suggesting that host serum albumin extends the NO half-life when NO is injected into the host skin by triatomine during their blood-feeding.
IntroductionHeart disease (HD) accounts for high morbidity and mortality in Brazil. Underserved populations often suffer long delays in diagnosis. We aimed to evaluate the feasibility of integrating ...screening echocardiography (echo) with remote interpretation in the established primary care system (PC) in Brazil and to assess HD prevalence.MethodsOver 11 months, 20 healthcare workers (four physicians, four nurses, and 12 technicians) at 16 PC centres were trained on simplified handheld echo protocols. Three screening (SC) groups, including all consented patients aged 17–20, 35–40 and 60–65 years, and patients referred (RF) for clinical indications underwent focused echo. Studies were remotely interpreted through telemedicine. Significant HD was defined as moderate/severe valve disease, ventricular dysfunction/hypertrophy, pericardial effusion, wall-motion abnormalities and congenital heart disease.ResultsTotal 1004 patients underwent echo; 299 (29.8%) in the SC group. Median age was 51±18 years, 63.9% females; 42.7% had cardiovascular symptoms. Significant HD was found in 354 (35.3%) patients (23.4% in SC vs 40.3% in RF group, p<0.001). Prevalence was higher in patients in the SC group aged >60 years (29.2%), compared with 35–40 (14.9%) and under 20 (16.5%), p=0.012. Comparing SC to RF groups, moderate/severe left ventricular dysfunction was observed in 4.1% vs 8.1%, p=0.03, mitral regurgitation in 8.9% vs 20.3%, p<0.001 and aortic stenosis in 5.4% vs 4.3%, p=0.51.ConclusionsIntegration focused echo into PC is feasible in Brazil as a strategy to deliver cardiovascular care to low-resourced areas through task shifting. The burden of HD observed suggests this tool may improve early diagnosis and referral.
IntroductionA novel handheld dual-electrode stick is a portable atrial fibrillation (AF) screening device (AFSD). We evaluated AFSD performance in primary care patients referred for echocardiogram ...(echo).MethodsThe AFSD has a light indication of irregular rhythm and single-lead ECG recording. Patients were instructed to hold the device for 1 min, and AF indication was recorded. A 12-lead ECG was performed for all AFSD-positive patients and 250 patients with negative AFSD screen. Echos were performed based on a clinical risk score: all high-risk patients and a sampling of low-risk patients underwent complete echo. Intermediate risk patients first had a screening echocardiogram, with a follow-up complete study if abnormality was suspected.ResultsIn 5 days, 1518 patients underwent clinical evaluation and cardiovascular risk stratification: mean age 58±16 years, 66% women. The AFSD was positive in 6.4%: 12.6% high risk, 6.1% intermediate risk and 2.2% low risk. Older age was a risk factor (9.3% vs 4.8% in those more than and less than 65 years, p=0.001). AFSD positive was independently associated with heart disease in echo (OR=3.9, 95% CI 2.1 to 7.2, p<0.001). Compared with 12-lead ECG, the AFSD had sensitivity of 90.2% (95% CI 77.0% to 97.3%) and specificity of 84.0% (95% CI 79.3% to 88.0%) for AF detection.ConclusionAFSD demonstrated high sensitivity for AF detection in primary care patients referred for echo. AF prevalence was substantial and independently associated with structural or functional heart disease, suggesting that AFSD screening could be a useful primary care tool to stratify risk and prioritise echo.
Background
Considering the limited accuracy of clinical examination for early diagnosis of rheumatic heart disease (RHD), echocardiography has emerged as an important epidemiological tool. The ideal ...setting for screening is yet to be defined. We aimed to evaluate the prevalence and pattern of latent RHD in schoolchildren (aged 5–18 years) and to compare effectiveness of screening between public schools, private schools, and primary care centers in Minas Gerais, Brazil.
Methods and Results
The PROVAR (Rheumatic Valve Disease Screening Program) study uses nonexperts and portable and handheld devices for RHD echocardiographic screening, with remote interpretation by telemedicine, according to the 2012 World Heart Federation criteria. Compliance with study consent and prevalence were compared between different screening settings, and variables associated with RHD were analyzed. In 26 months, 12 048 students were screened in 52 public schools (n=10 901), 2 private schools (n=589), and 3 primary care centers (n=558). Median age was 12.9 years, and 55.4% were girls. Overall RHD prevalence was 4.0% borderline (n=486) and 0.5% definite (n=63), with statistically similar rates between public schools (4.6%), private schools (3.5%), and primary care centers (4.8%) (P=0.24). The percentage of informed consents signed was higher in primary care centers (84.4%) and private schools (66.9%) compared with public schools (38.7%) (P<0.001). Prevalence was higher in children ≥12 years (5.3% versus 3.1%; P<0.001) and girls (4.9% versus 4.0%; P=0.02). Only age (odds ratio, 1.12; 95% confidence interval, 1.09–1.17; P<0.001) was independently associated with RHD.
Conclusions
RHD screening in primary care centers seems to achieve higher coverage rates. Prevalence among schoolchildren is significantly high, with rates higher than expected in private schools of high‐income areas. These data are important for the formulation of public policies to confront RHD.
Abstract Background Accurate estimates of Rheumatic Heart Disease (RHD) burden are needed to justify improved integration of RHD prevention and screening into the public health systems, but data from ...Latin America are still sparse. Objective To determine the prevalence of RHD among socioeconomically disadvantaged youth (5–18 years) in Brazil and examine risk factors for the disease. Methods The PROVAR program utilizes non-expert screeners, telemedicine, and handheld and standard portable echocardiography to conduct echocardiographic screening in socioeconomically disadvantaged schools in Minas Gerais, Brazil. Cardiologists in the US and Brazil provide expert interpretation according to the 2012 World Heart Federation Guidelines. Here we report prevalence data from the first 14 months of screening, and examine risk factors for RHD. Results 5996 students were screened across 21 schools. Median age was 11.9 9.0/15.0 years, 59% females. RHD prevalence was 42/1000 (n = 251): 37/1000 borderline (n = 221) and 5/1000 definite (n = 30). Pathologic mitral regurgitation was observed in 203 (80.9%), pathologic aortic regurgitation in 38 (15.1%), and mixed mitral/aortic valve disease in 10 (4.0%) children. Older children had higher prevalence (50/1000 vs. 28/1000, p < 0.001), but no difference was observed between northern (lower resourced) and central areas (34/1000 vs. 44/1000, p = 0.31). Females had higher prevalence (48/1000 vs. 35/1000, p = 0.016). Age (OR = 1.15, 95% CI:1.10–1.21, p < 0.001) was the only variable independently associated with RHD findings. Conclusions RHD continues to be an important and under recognized condition among socioeconomically disadvantaged Brazilian schoolchildren. Our data adds to the compelling case for renewed investment in RHD prevention and early detection in Latin America.
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