Dual slag filters for enhanced phosphorus removal from domestic waste water: performance and mechanisms

Abstract

The phosphorus (P) removal of five combinations of dual filters consisting of blast furnace slag (BFS), argon oxygen decarburisation slag (AOD) and electric arc furnace slag (EAF) was evaluated in column experiments with domestic waste water. The columns were fed with waste water for 24 days. The column with only EAF had the best P removal performance (above 93% throughout the experiment). The speciation of the bound P was evaluated by P K-edge X-ray absorption near-edge structure (XANES) spectroscopy. In all five columns, the main P species of the slag packed in the outlet chamber was amorphous calcium phosphate (ACP). In samples from the inlet chambers, the contributions from crystalline Ca phosphates, P adsorbed on gibbsite and P adsorbed on ferrihydrite were usually much greater, suggesting a shift of P removal mechanism as the waste water travelled from the inlet to the outlet. The results provide strong evidence that P was predominantly removed by the slags through the formation of ACP. However, as the pH decreased with time due to the progressively lower dissolution of alkaline silicate minerals from the slag, the ACP was rendered unstable and hence redissolved, changing the P speciation. It is suggested that this process strongly affected the lifespan of the slag filters. Of the slags examined, EAF slag had the best P removal characteristics and BFS the worst, which probably reflected different dissolution rates of alkaline silicates in the slags.

Comparing the effects of 3 different pressure ulcer prevention support surfaces on the structure and function of heel and sacral skin: An exploratory cross-over trial

Special support surfaces are key in pressure ulcer prevention. The aim of this study was to measure the effects of 3 different types of mattresses (reactive gel, active alternating air, basic foam) on skin properties of the sacral and heel skin after 2 hours loading. Fifteen healthy females (median age 66 years) were included. Transepidermal water loss, skin surface temperature, erythema, stratum corneum hydration, epidermal hydration, skin extensibility, elastic function, and recovery as well as skin roughness parameters were measured under controlled room conditions before loading, immediately after loading, and 20 minutes post-loading in the supine position on the different mattresses. The highest increases in transepidermal water loss, skin temperature, and erythema were observed for the foam mattress after loading, indicating higher deformation and occlusion. Cutaneous stiffness decreased in all 3 groups, indicating structural changes during loading. There was a substantial decrease of mean roughness at the heel skin in the foam group, leading to a flattening of the skin surface. Study results indicate that the type of support surface influences skin structure and function during loading. The gel and air mattress appeared to be more protective compared with the foam mattress, but the differences between the gel and air were minor.

Predicting delayed healing: The diagnostic accuracy of a venous leg ulcer risk assessment tool

The aim of this study was to validate a newly developed tool that can predict the risk of failure to heal of a venous leg ulcer in 24 weeks. The risk assessment tool was validated, and performance of the tool was assessed using Area Under the Receiver Operating Characteristic Curve (AUC) analysis. Retrospective and prospective validation was conducted through multi-site, longitudinal studies. In the retrospective study (n = 318), 30% of ulcers did not heal within 24 weeks, with the tool demonstrating an AUC of 0.80 (95% CI, 0.68-0.93, P < .001) for the total score. In the prospective study across 10 clinical sites (n = 225), 31% (n = 68) of ulcers did not heal within 24 weeks. Participants were classified with the RAT at enrolment as being at low risk (27%), moderate risk (53%) or high risk (20%) of delayed healing; the proportion of wounds unhealed at 24 weeks was 6%, 29% and 59%, respectively. Validation results of the total score indicated good discrimination and goodness of fit with an AUC of 0.78 (95% CI, 0.71-0.85, P < .001). Validation of this risk assessment tool offers assurance that realistic outcomes can be predicted for patients, and scores can guide early decisions on interventions to address specific risk factors for failing to heal, thus promoting timely healing.

Pseudomonas infection following total contact cast application

Efficacy and safety of fosmidomycin-piperaquine as non-artemisinin-based combination therapy for uncomplicated falciparum malaria - A single-arm, age-de-escalation proof of concept study in Gabon

Abstract

Background

Fosmidomycin-piperaquine is being developed as non-artemisinin-based combination therapy to meet the challenge of emerging artemisinin resistance.

Methods

The study was a phase 2 single arm open label proof of concept study of the efficacy, tolerability and safety of fosmidomycin-piperaquine for the treatment of uncomplicated Plasmodium falciparum mono-infection in Gabon. Adults and children of both sexes with initial parasite counts between 1,000 and 150,000/µL were eligible for oral treatment with fosmidomycin (twice daily doses of 30mg/kg), and piperaquine (once daily dose of 16mg/kg) for three days and followed-up for 63 days. The primary efficacy endpoint was the per protocol PCR-corrected Day 28 adequate clinical and parasitological response (ACPR).

Results

100 patients were enrolled. The PCR-corrected Day 28 ACPR rate was 83/83 or 100% (95% CI: 96-100). Fourteen patients had asexual parasitaemia between Day 28 and Day 63; all were typed by PCR as new infections. Fosmidomycin-piperaquine therapy led to rapid parasite clearance (median: 36h; IQR: 6-60) and fever clearance time (median: 12h; IQR: 6-48). The electrocardiogram assessments showed two subjects with QT corrected from the formula of Bazett (QTcB) >500msec following study drug administration. The majority of adverse events affected the gastrointestinal and respiratory tracts and were transient and mild to moderate in severity.

Conclusions

This is the first report of the use of the combination fosmidomycin-piperaquine, a non-artemisinin-based combination therapy in clinical development. The combination appeared to have high efficacy, to be safe and well tolerated despite observed transient changes in electrocardiogram with prolongation of the QT interval.

A Simple Symptom Score for Acute HIV Infection in a San Diego Community Based Screening Program

Abstract

Background

Treatment of acute HIV infection (AHI) decreases transmission and preserves immune function, but AHI diagnosis remains resource-intensive. Risk-based scores predictive for AHI have been described for high-risk groups, however symptom-based scores could be more generalizable across populations.

Methods

Adults who tested either positive for AHI (antibody-negative, HIV nucleic acid test [NAT]-positive) or HIV NAT-negative with the community-based Early Test HIV screening program in San Diego were retrospectively randomized 2:1 into a derivation and validation set. In the former, symptoms significant for AHI in a multivariate logistic regression model were assigned a score value (the odds ratio rounded to the nearest integer). The score was assessed in the validation set using receiver operating characteristics and areas under the curve (AUC). An optimal cut-off score was found using Youden's index.

Results

Of 998 participants (including 737 men who have sex with men (MSM), 149 non-MSM men, 109 ciswomen and 3 trans women), 113 had AHI (including 109 MSM). Compared to HIV-negative cases, AHI cases reported more symptoms (median 4 vs 0, p<0.01). Fever, myalgia and weight loss were significantly associated with AHI in the multivariate model and corresponded to 11, 8 and 4 score points, respectively. The summed score yielded AUC of 0.85 (95%CI 0.77-0.93). A score of ≥11 was 72% sensitive, 96% specific with diagnostic odds ratio of 70.27 (95%CI 28.14-175.93).

Conclusions

A 3-symptom score accurately predicted AHI in a community based screening program and may inform allocation of resources in settings that do not routinely screen for AHI.

Atypical Skeletal Muscle Profiles in HIV+ Asymptomatic Middle-Aged Adults

Abstract

Background

Human immunodeficiency virus (HIV)-infected individuals are at increased risk of age-associated functional impairment, even with effective antiretroviral therapy (ART). A concurrent characterization of skeletal muscle, physical function, and immune phenotype in aviremic middle-aged HIV+ adults represents a knowledge gap in prognostic biomarker discovery.

Methods

We undertook a prospective observational study of 170 middle-aged, HIV-infected ambulatory men and women with CD4+ T-cell counts of at least 350 per microliter and undetectable plasma viremia while on effective antiretroviral therapy, and uninfected control participants. We measured biomarkers for inflammation and immune activation, fatigue, the Veterans Aging Cohort Study (VACS) mortality index, and physical function. A subset also received a skeletal muscle biopsy and computerized tomography scan.

Results

Compared to the uninfected, HIV+ participants displayed increased immune activation (P<0·001), inflammation (P=0·001) and fatigue (P=0·010), and in a regression model adjusting for age and sex displayed deficits in stair climb power (P<0.001), gait speed (P=0.036) and predicted metabolic equivalents (P=0.019). Skeletal muscle displayed reduced nuclear PGC-1alphapositive myonuclei (P=0·006) and increased internalized myonuclei (P<0·001) that correlated with immune activation (P=0·003) and leukocyte infiltration (P<0·001). Internalized myonuclei improved a model for HIV discrimination, increasing the C-statistic from 0·84 to 0·90.

Conclusions

Asymptomatic HIV-infected middle-aged adults display atypical skeletal muscle profiles, subclinical deficits in physical function and persistent inflammation and immune activation. Identifying biomarker profiles for muscle dysregulation and risk for future functional decline in the HIV-infected population will be key to developing and monitoring preventative interventions.

Trial Registration

This protocol is registered with ClinicalTrials.gov (NCT03011957).

CDC Yellow Book 2018: Health Information for International Travel

CDC Yellow Book 2018: Health Information for International Travel Edited by BrunetteGary WKozarskyPhyllis. Oxford University Press, 2017. 704 pp. £49.95 (paperback). ISBN: 9780190628611.

Glucose-6-phosphate dehydrogenase inhibition attenuates acute lung injury through reduction in NADPH oxidase derived reactive oxygen species

Abstract

Acute lung injury (ALI) is a heterogeneous disease with the hallmarks of alveolar capillary membrane injury, increased pulmonary edema and pulmonary inflammation. The commonest direct etiological factor for ALI is usually parenchymal lung infection or hemorrhage. Reactive oxygen species (ROS) generated by NADPH oxidase (NOX2) are thought to play an important role in the pathophysiology of ALI. Glucose-6-phosphate dehydrogenase (G6PD) plays an important role both in production of ROS as well as their removal through supply of NADPH. However, how G6PD modulation affects NOX2-mediated ROS in the airway epithelial cells (AECs) during acute lung injury has not been explored earlier. Therefore, we investigated the effect of G6PD inhibitor, 6-aminonicotinamide on G6PD activity, NOX2 expression, ROS production and enzymatic antioxidants in AECs in a mouse model of ALI induced by lipopolysaccharide (LPS). ALI led to increased G6PD activity in the AECs with concomitant elevation of NOX2, ROS, SOD1, and nitrotyrosine. G6PD inhibitor led to reduction of LPS-induced airway inflammation, bronchoalveolar lavage fluid protein concentration as well as NOX2-derived ROS and subsequent oxidative stress. On the other hand, ALI led to decreased glutathione reductase activity in AECs which was normalized by G6PD inhibitor. These data show that activation of G6PD is associated with enhancement of oxidative inflammation in during ALI. Therefore, inhibition of G6PD might be a beneficial strategy during ALI to limit oxidative damage and ameliorate airway inflammation. This article is protected by copyright. All rights reserved.

Carbon Monoxide Off-Gassing From Bags of Wood Pellets

Abstract

Wood pellets are increasingly used for space heating in the United States and globally. Prior work has shown that stored bulk wood pellets produce sufficient carbon monoxide (CO) to represent a health concern and exceed regulatory standards for occupational exposures. However, most of the pellets used for residential heating are sold in 40-pound (18.1 kg) plastic bags. This study measured CO emission factors from fresh, bagged-wood pellets as a function of temperature and relative humidity. CO concentrations increased with increasing temperature and moisture in the container. CO measurements in a pellet mill warehouse with stored pallets of bagged pellets had 8-h average CO concentrations up to 100 ppm exceeding occupational standards for worker exposure. Thus, manufacturers, distributors, and home owners should be aware of the potential for CO in storage areas and design facilities with appropriate ventilation and CO sensors.