Sandovalwentworth0578

From DigitalMaine Transcription Project
Jump to: navigation, search

Addition of 1 wt% GAC to the soil successfully reduced the PUF by up to 99.4%, with values of 0.006 (PFOA) and 0.005 (PFOS) in 2.6 wt% SOM-treated soil and 0.079 (PFOA) and 0.023 (PFOS) in 4.0 wt% SOM-treated soil. Although the PUF in the GAC-treated soil was drastically decreased, the PUF of the soil with 4.0 wt% SOM was at least four times higher than that with 2.6 wt% SOM. Therefore, SOM content is an important consideration in the remediation of PFOA- and PFOS-contaminated farmland soil using carbonaceous adsorbent.This work investigated the concentrations and health risks of polycyclic aromatic hydrocarbons (PAHs) found in Chilean soils for the first time. The urban and suburban soils were collected from 28 sampling sites in three regions of Chile Magallanes (in Punta Arenas commune), Valparaíso and the Santiago metropolitan area. The PAH concentrations, fractions and their potential sources were studied. Statistical analyses using t tests (p  less then  0.01) showed that (a) PAH concentrations in the urban sites were higher than those in the suburban sites; (b) the presence of anthracene and chrysene was significantly greater in the urban sites than the suburban sites; and (c) the fraction of four-ring PAHs to total PAHs was larger in the urban sites than the suburban sites. The primary PAH source in urban soils was determined to be the combustion of gasoline, grass, wood and coal. In contrast, PAHs in suburban soils were possibly derived from pyrogenic sources (e.g. incomplete combustions). The total cancer risks (TCRs) and the total hazard index (HI) were quantified from 12 PAHs in both urban and suburban soils in terms of cancer and non-cancer risks, respectively. The average TCR of all sites was within an acceptable level (TCR  less then  10-6), and none of the HIs from any locations were deemed harmful (HI  less then  1).The bioremoval potential of Pseudomonas plecoglossicida toward mixed contaminants was explored through the coupled biostimulation and bioaugmentation in soil microcosm. Response surface methodology was employed to optimize nutrients and innoculum size for the cometabolic removal of two representative chloroethylenes, trichloroethylene (TCE) and cis-1,2-dichloroethylene (cis-DCE), mixed with benzene, toluene, ethylbenzene, and xylenes (BTEX). The interactive effects of nutrients [nitrogen (N) and phosphorus (P)] and inoculum size toward the bioremoval of mixture of BTEX (600 mg kg-1), cis-DCE (10 mg kg-1), and TCE (10 mg kg-1) were estimated using principal component analysis and two-dimensional hierarchical cluster analysis. The optimal condition was confirmed with CNP ratio of 10026.71.8-4.8 and higher inoculum size (≥25%), where 97.7% of benzene, 98.3% of toluene, 91.2% of ethylbenzene, 45.6% of m,p-xylene, 31.2% of o-xylene, 26.9% of cis-DCE, and 33.5% of TCE were bioremoved.Dissimilatory nitrate reduction to ammonia (DNRA) process, competing with denitrification and anaerobic ammonia oxidation (anammox) for nitrate, is an important nitrogen retention pathway in the environment. Previous studies on DNRA bacterial diversity and composition focused on the surface sediments in estuaries, but studies on the deep sediments are limited, and the linkage between DNRA community structure and complex estuarine environment remains unclear. In this study, through high-throughput sequencing of nrfA gene followed by high-resolution sample inference, we examined spatially and temporally the composition and diversity of DNRA bacteria along a salinity gradient in five sediment cores of the Pearl River Estuary (PRE). We found a higher diversity and richness of DNRA bacteria in sediments with lower organic carbon, where sea water intersects fresh water. Moreover, the DNRA bacterial communities had the specific spatially distribution coupling with their metabolic difference along the salinity gradient of the Pearl River Estuary, but no obvious difference along the sediment depth. The distribution of DNRA bacteria in the PRE was largely driven by various environmental factors, including salinity, Oxidation-Reduction Potential (ORP), ammonium, nitrate and Corg/NO3-. Furthermore, dominant DNRA bacteria were found to be the key populations of DNRA communities in the PRE sediments by network analysis. Collectively, our results showed that niche difference of DNRA bacteria indeed occurs in the Pearl River Estuary.Assessing pulmonary lesions using computed tomography (CT) images is of great significance to the severity diagnosis and treatment of coronavirus disease 2019 (COVID-19)-infected patients. Such assessment mainly depends on radiologists' subjective judgment, which is inefficient and presents difficulty for those with low levels of experience, especially in rural areas. This work focuses on developing a radiomics signature to quantitatively analyze whether COVID-19-infected pulmonary lesions are mild (Grade I) or moderate/severe (Grade II). We retrospectively analyzed 1160 COVID-19-infected pulmonary lesions from 16 hospitals. First, texture features were extracted from the pulmonary lesion regions of CT images. Then, feature preselection was performed and a radiomics signature was built using a stepwise logistic regression. The stepwise logistic regression also calculated the correlation between the radiomics signature and the grade of a pulmonary lesion. Finally, a logistic regression model was trained to clar clinical use.

Due to growing expenditures, health systems have been pushed to improve decision-making practices on resource allocation. see more This study aimed to identify which practices of priority setting and resource allocation (PSRA) have been used in healthcare systems of high-income countries.

A scoping literature review (2007-2019) was conducted to map empirical PSRA activities. A two-stage screening process was utilized to identify existing approaches and cluster similar frameworks. That was complemented with a gray literature and horizontal scanning. A narrative synthesis was carried out to make sense of the existing literature and current state of PSRA practices in healthcare.

One thousand five hundred eighty five references were found in the peer-reviewed literature and 25 papers were selected for full-review. We identified three major types of decision-making framework in PSRA 1) Program Budgeting and Marginal Analysis (PBMA); 2) Health Technology Assessment (HTA); and 3) Multiple-criteria value assessment. Our narrative synthesis indicates these formal frameworks of priority setting and resource allocation have been mostly implemented in episodic exercises with poor follow-up and evaluation.