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1.
BMC Public Health ; 23(1): 2334, 2023 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-38001441

RESUMEN

BACKGROUND: Although social housing provides access to safe and affordable housing, recent studies have found that social housing tenants consistently have lower levels of health and well-being compared to other people. Given this, there is a need to examine multimorbidity for social housing tenants. METHODS: Secondary data analysis of the 2017-18 Australian National Health Survey (n = 14,327) compared the health of adults residing in social housing compared to people in other housing types (private rentals, homeowners, and homeowners/mortgagees). RESULTS: Most health factors examined were more prevalent in social housing tenants compared to those living in other housing types. Individual health problems identified as more highly prevalent in social housing tenants compared to all other housing types included mental health issues (43%), arthritis (36%), back problems (32%), hypertension (25%), asthma (22%) and COPD (11%). 24% of social housing tenants reported five or more health factors compared to 3-6% of people in other housing types. CONCLUSIONS: Although these findings are not unexpected, they provide more detailed evidence that social housing providers and policy makers should consider when planning future initiatives.


Asunto(s)
Vivienda , Vivienda Popular , Adulto , Humanos , Australia/epidemiología , Encuestas Epidemiológicas
2.
BMC Public Health ; 22(1): 582, 2022 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-35331186

RESUMEN

BACKGROUND: Social housing provides homes for some of the most vulnerable in society. Those in social housing often have complex issues that may require support. Limited research has examined the unmet needs of those living in social housing from the tenant perspective. This exploratory study aimed to embark on filling this gap. METHODS: A cross-sectional study survey of adult social housing tenants in New South Wales, Australia. Consenting tenants completed a survey asking about their support needs across five domains: transport, employment and financial stress; housing and safety; health and health behaviour; access to services; and control over one's life. Negative binomial regression analysis was used to examine associations between the mean number of support needs and characteristics. RESULTS: Of the 104 tenants invited, 101 agreed to participate (97%) of which 100 completed the survey. Paying unexpected bills' (43%), feeling sad or anxious (40%), feelings of anger or frustration (34%), and memory or concentration problems (33%) were the most prevalent reported needs. Other needs included antisocial behaviour from neighbours (31%) and having control in the direction your life is taking (27%). Seventy-five percent of tenants reported at least one need, with an average of seven needs across the sample (median 5.5, range 0-24). Tenants who identified as Aboriginal or Torres Strait Islander had a higher number of needs compared to other tenants (RR 1.87 95% CI 1.08 to 3.35). CONCLUSIONS: More research describing tenant wellbeing needs is required to guide initiatives improving tenant wellbeing. Development of a standardised tool to measure and prioritise tenant wellbeing needs would be beneficial. There is a need for well-controlled research to establish the potential effectiveness and cost effectiveness of initiatives implemented at the policy or housing provider level. Future research must consider the multifaceted needs of this population. Further, Aboriginal and Torres Strait Islander people are generally overrepresented in social housing in Australia, and in this study Aboriginal and Torres Strait Islander tenants reported a higher number of needs compared to non-Aboriginal and Torres Strait Islander tenants. Given this, future research should ensure measurement tools or strategy initiatives are culturally sensitive and appropriate, and are developed in collaboration with Aboriginal and Torres Strait Islander communities.


Asunto(s)
Servicios de Salud del Indígena , Nativos de Hawái y Otras Islas del Pacífico , Adulto , Estudios Transversales , Conductas Relacionadas con la Salud , Vivienda , Humanos , Encuestas y Cuestionarios
3.
Environ Sci Technol ; 55(1): 313-323, 2021 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-33351591

RESUMEN

Soil and groundwater from an aqueous film-forming foam (AFFF)-impacted site were sampled at high resolution (n = 105 for soil, n = 58 for groundwater) and analyzed for an extensive list of anionic, zwitterionic, and cationic poly- and perfluoroalkyl substances (PFASs). Spatial trends for perfluoroalkyl acids and many precursors enabled a better understanding of PFAS composition, transport, and transformation. All PFASs without analytical standards were semi-quantified. Summed PFAS and individual PFAS concentrations were often higher at depth than near the surface in soil and groundwater. Zwitterionic and cationic compounds composed a majority of the total PFAS mass (up to 97%) in firefighter training area (FTA) soil. Composition of PFAS class, chain length, and structural isomers changed with depth and distance from the FTA, suggesting in situ transformation and differential transport. The percentage of branched perfluorooctane sulfonate increased with depth, consistent with differential isomeric transport. However, linear perfluorooctanoic acid (PFOA) was enriched, suggesting fluorotelomer precursor transformation to linear PFOA. Perfluorohexane sulfonamide, a potential transformation product of sulfonamide-based PFASs, was present at high concentrations (maximum 448 ng/g in soil, 3.4 mg/L in groundwater). Precursor compounds may create long-term sources of perfluoroalkyl acids, although many pathways remain unknown; precursor analysis is critical for PFAS fate and transport understanding.


Asunto(s)
Ácidos Alcanesulfónicos , Fluorocarburos , Agua Subterránea , Contaminantes Químicos del Agua , Fluorocarburos/análisis , Suelo , Agua , Contaminantes Químicos del Agua/análisis
4.
Environ Sci Technol ; 54(8): 4952-4962, 2020 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-32200626

RESUMEN

Poly- and perfluoroalkyl substances (PFASs) derived from aqueous film-forming foam (AFFF) are increasingly recognized as groundwater contaminants, though the composition and distribution of AFFF-derived PFASs associated with soils and subsurface sediments remain largely unknown. This is particularly true for zwitterionic and cationic PFASs, which may be incompletely extracted from subsurface solids by analytical methods developed for anionic PFASs. Therefore, a method involving sequential basic and acidic methanol extractions was developed and evaluated for recovery of anionic, cationic, and zwitterionic PFASs from field-collected, AFFF-impacted soils. The method was validated by spike-recovery experiments with equilibrated soil-water-AFFF and analytical standards. To determine the relative importance of PFASs lacking commercially available analytical standards, their concentrations were estimated by a novel semiquantitation approach. Total PFAS concentrations determined by semiquantitation were compared with concentrations determined by the total oxidizable precursor assay. Finally, the described method was applied to two soil cores from former fire-training areas in which cations and zwitterions were found to contribute up to 97% of the total PFAS mass. This result demonstrates the need for extraction and analysis methods, such as the ones presented here, that are capable of quantifying cationic and zwitterionic PFASs in AFFF-impacted source zone soils.


Asunto(s)
Fluorocarburos/análisis , Agua Subterránea , Contaminantes Químicos del Agua/análisis , Suelo , Agua
5.
Environ Sci Technol ; 54(24): 15768-15777, 2020 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-33270425

RESUMEN

Transport of poly- and perfluoroalkyl substances (PFAS) at aqueous film-forming foam (AFFF)-impacted sites is limited by various processes that can retain PFAS mass within the source area. This study used concentration data obtained via a high-resolution sampling and analytical protocol to estimate the PFAS mass distribution in source and downgradient areas of a former firefighter training area. The total PFAS mass present at the site was approximately 222 kg, with 106 kg as perfluoroalkyl acids (PFAAs) and 116 kg as polyfluorinated precursors. Zwitterionic and cationic PFAS represented 83% of the total precursor mass and were found primarily in the source and up/side-gradient areas (75%), likely due to preferential hydrophobic partitioning, electrostatic interactions, and diffusion into lower-permeability soils. Based on the release history and the high percentage of total PFAS mass represented by precursors (primarily electrochemical fluorination-derived compounds), the estimated conversion rate of precursors to PFAAs was less than 2% annually. Eighty-two percent of the total PFAS mass was encountered in lower-permeability soils, which limited the potential for advection and transformation. This contributed to a 99% decrease in the mass discharge rate at the far-downgradient plume (0.048 kg/yr compared to the near-source area (3.6 kg/yr)). The results provide field-scale evidence of the importance of these PFAS retention processes at sites where AFFF has been released.


Asunto(s)
Fluorocarburos , Contaminantes Químicos del Agua , Cationes , Fluorocarburos/análisis , Suelo , Agua , Contaminantes Químicos del Agua/análisis
6.
J Environ Manage ; 206: 60-64, 2018 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-29059571

RESUMEN

1,4-Dioxane (dioxane) is a groundwater contaminant of emerging concern for which bioremediation may become a practical remediation strategy. Therefore, it is important to advance our heuristic understanding of geochemical parameters that are most influential on the potential success of intrinsic bioremediation of dioxane-impacted sites. Here, Pearson's and Spearman's correlation and linear regression analyses were conducted to discern associations between 1,4-dioxane biodegradation activity measured in aerobic microcosms and groundwater geochemical parameters at four different contaminated sites. Dissolved oxygen, which is known to limit dioxane biodegradation, was excluded as a limiting factor in this analysis. Biodegradation activity was positively associated with dioxane concentrations (p < 0.01; R < 0.70) as well as the number of catabolic thmA gene copies (p < 0.01; R = 0.80) encoding dioxane monooxygenase. Thus, whereas environmental factors such as pH, temperature, and nutrients may influence dioxane biodegradation, these parameters did not exert as strong of an influence on potential biodegradation activity as the in situ concentration of substrate dioxane at the time of sampling. This analysis infers that aerobic sites with higher dioxane concentrations are more likely to select and sustain a thriving population of dioxane degraders, while sites with relatively low dioxane concentrations would be more difficult to attenuate naturally and may require alternative remediation strategies.


Asunto(s)
Biodegradación Ambiental , Dioxanos , Contaminantes Químicos del Agua , Agua Subterránea
7.
Proc Natl Acad Sci U S A ; 110(32): 13120-5, 2013 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-23878244

RESUMEN

Bacterial survival requires the rapid propagation of signals through gene networks during stress, but how this is achieved is not well understood. This study systematically characterizes the signaling dynamics of a cascade of RNA-protein interactions in the CsrA system, which regulates stress responses and biofilm formation in Escherichia coli. Noncoding RNAs are at the center of the CsrA system; target mRNAs are bound by CsrA proteins that inhibit their translation, CsrA proteins are sequestered by CsrB noncoding RNAs, and the degradation of CsrB RNAs is increased by CsrD proteins. Here, we show using in vivo experiments and quantitative modeling that the CsrA system integrates three strategies to achieve rapid and robust signaling. These strategies include: (i) the sequestration of stable proteins by noncoding RNAs, which rapidly inactivates protein activity; (ii) the degradation of stable noncoding RNAs, which enables their rapid removal; and (iii) a negative-feedback loop created by CsrA repression of CsrD production, which reduces the time for the system to achieve steady state. We also demonstrate that sequestration in the CsrA system results in signaling that is robust to growth rates because it does not rely on the slow dilution of molecules via cell division; therefore, signaling can occur even during growth arrest induced by starvation or antibiotic treatment.


Asunto(s)
Proteínas de Escherichia coli/genética , ARN Bacteriano/genética , Proteínas de Unión al ARN/genética , Proteínas Represoras/genética , Transducción de Señal/genética , Algoritmos , Biopelículas/crecimiento & desarrollo , Escherichia coli/genética , Escherichia coli/metabolismo , Escherichia coli/fisiología , Proteínas de Escherichia coli/metabolismo , Retroalimentación Fisiológica , Regulación Bacteriana de la Expresión Génica , Glucosa-1-Fosfato Adenililtransferasa/genética , Glucosa-1-Fosfato Adenililtransferasa/metabolismo , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Modelos Genéticos , Unión Proteica , ARN Bacteriano/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/metabolismo , Proteínas Represoras/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
8.
Environ Sci Technol ; 49(11): 6510-8, 2015 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-25970261

RESUMEN

There is a critical need to develop appropriate management strategies for 1,4-dioxane (dioxane) due to its widespread occurrence and perceived recalcitrance at groundwater sites where chlorinated solvents are present. A comprehensive evaluation of California state (GeoTracker) and Air Force monitoring records was used to provide significant evidence of dioxane attenuation at field sites. Temporal changes in the site-wide maximum concentrations were used to estimate source attenuation rates at the GeoTracker sites (median length of monitoring period = 6.8 years). While attenuation could not be established at all sites, statistically significant positive attenuation rates were confirmed at 22 sites. At sites where dioxane and chlorinated solvents were present, the median value of all statistically significant dioxane source attenuation rates (equivalent half-life = 31 months; n = 34) was lower than 1,1,1-trichloroethane (TCA) but similar to 1,1-dichloroethene (1,1-DCE) and trichloroethene (TCE). Dioxane attenuation rates were positively correlated with rates for 1,1-DCE and TCE but not TCA. At this set of sites, there was little evidence that chlorinated solvent remedial efforts (e.g., chemical oxidation, enhanced bioremediation) impacted dioxane attenuation. Attenuation rates based on well-specific records from the Air Force data set confirmed significant dioxane attenuation (131 out of 441 wells) at a similar frequency and extent (median equivalent half-life = 48 months) as observed at the California sites. Linear discriminant analysis established a positive correlation between dioxane attenuation and increasing concentrations of dissolved oxygen, while the same analysis found a negative correlation with metals and CVOC concentrations. The magnitude and prevalence of dioxane attenuation documented here suggest that natural attenuation may be used to manage some but not necessarily all dioxane-impacted sites.


Asunto(s)
Dioxanos/análisis , Agua Subterránea/química , Halogenación , Solventes/química , Contaminantes Químicos del Agua/análisis , California , Dicloroetilenos/análisis , Dioxanos/química , Análisis Discriminante , Semivida , Cinética , Tricloroetanos/análisis , Tricloroetileno/análisis
9.
Ground Water ; 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38940354

RESUMEN

Understanding fate and transport processes for per- and poly-fluoroalkyl substances (PFAS) is critical for managing impacted sites. "PFAS Salting Out" in groundwater, defined herein, is an understudied process where PFAS in fresh groundwater mixes with saline groundwater near marine shorelines, which increases sorption of PFAS to aquifer solids. While sorption reduces PFAS mass discharge to marine surface water, the fraction that sorbs to beach sediments may be mobilized under future salinity changes. The objective of this study was to conceptually explore the potential for PFAS Salting Out in sandy beach environments and to perform a preliminary broad-scale characterization of sandy shoreline areas in the continental U.S. While no site-specific PFAS data were collected, our conceptual approach involved developing a multivariate regression model that assessed how tidal amplitude and freshwater submarine groundwater discharge affect the mixing of fresh and saline groundwater in sandy coastal aquifers. We then applied this model to 143 U.S. shoreline areas with sandy beaches (21% of total beaches in the USA), indirectly mapping potential salinity increases in shallow freshwater PFAS plumes as low (<10 ppt), medium (10-20 ppt), or high (>20 ppt) along groundwater flow paths before reaching the ocean. Higher potential salinity increases were observed in West Coast bays and the North Atlantic coastline, due to the combination of moderate to large tides and large fresh groundwater discharge rates, while lower increases occurred along the Gulf of Mexico and the southern Florida Atlantic coast. The salinity increases were used to estimate potential perfluorooctane sulfonic acid (PFOS) sorption in groundwater due to salting out processes. Low-category shorelines may see a 1- to 2.5-fold increase in sorption of PFOS, medium-category a 2.0- to 6.4-fold increase, and high-category a 3.8- to 25-fold increase in PFOS sorption. The analysis presented provides a first critical step in developing a large-scale approach to classify the PFAS Salting Out potential along shorelines and the limitations of the approach adopted highlights important areas for further research.

10.
Surg Neurol Int ; 14: 252, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37560598

RESUMEN

Background: Hepatocellular carcinoma (HCC) is a common malignant tumor with a 5-year survival rate of 10%, presenting with extrahepatic metastases in 15-17% of patients. HCC-bone metastases represent approximately one-quarter of all HCC metastases, most frequently in the spine, pelvis, ribs, or femur. HCC-skull metastases, however, make up 0.4-1.6% of all HCC- bone metastases. Furthermore, solitary HCC-skull metastasis without known active primary HCC is an unusual presentation warranting further review and consideration. Case Description: Here, the authors report a unique case of a solitary HCC-skull metastasis in a patient without known active cancer but in long-term remission for HCC. The patient is a 69-year-old male with past HCC who presented with a nontender skull mass. A computed tomography scan showed a heterogeneously enhancing mass centered in the high left parietal bone with intracranial extension. There was a noted mass effect on the left posterior frontoparietal region without worrisome midline shift. Pathology ultimately revealed the mass to be metastatic HCC. To aid in the understanding and clinical management of this rare presentation, we reviewed the literature regarding clinical presentation, radiological features, pathology, and outcome. Conclusion: Ultimately, early detection of the primary source of cancer is pivotal to successful treatment and prognosis, and skull lesions such as these must include HCC in the differential diagnosis.

11.
Artículo en Inglés | MEDLINE | ID: mdl-37754612

RESUMEN

BACKGROUND: Social housing tenants have poorer health outcomes than homeowners or those renting privately. Health literacy is associated with access to care and health outcomes. This study aimed to examine the health literacy of Australian adults residing in social housing compared with that of people living in other housing types. METHODS: A secondary analysis of the Australian National Health Survey 2017-2018 dataset was undertaken. A total of 5275 respondents were included in the sample and completed the Health Literacy Questionnaire (HLQ). Respondents were categorised according to their housing tenure: 163 (3.1%) respondents were living in social housing, 873 (17%) were living in private rentals, 2085 (40%) were homeowners, and 2154 (41%) were homeowners/mortgages. Mean scores were calculated for each of the nine health literacy domains in the HLQ and compared across housing tenure using linear regression models. RESULTS: Social housing tenants had lower mean domain scores than either homeowners, owner mortgagees, or private renters on six of the nine health literacy domains. This included 'having sufficient information to manage my health', 'social support for health', 'ability to engage with healthcare providers', 'navigating the healthcare system' 'ability to find good health information', and being able to 'understand health information enough to know what to do'. However, the differences in mean scores were small. CONCLUSIONS: Increasing health literacy may be an important part of multicomponent interventions seeking to improve the health and wellbeing of social housing tenants.

12.
PLoS Comput Biol ; 7(8): e1002138, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21876666

RESUMEN

Bacteria possess networks of small RNAs (sRNAs) that are important for modulating gene expression. At the center of many of these sRNA networks is the Hfq protein. Hfq's role is to quickly match cognate sRNAs and target mRNAs from among a large number of possible combinations and anneal them to form duplexes. Here we show using a kinetic model that Hfq can efficiently and robustly achieve this difficult task by minimizing the sequestration of sRNAs and target mRNAs in Hfq complexes. This sequestration can be reduced by two non-mutually exclusive kinetic mechanisms. The first mechanism involves heterotropic cooperativity (where sRNA and target mRNA binding to Hfq is influenced by other RNAs bound to Hfq); this cooperativity can selectively decrease singly-bound Hfq complexes and ternary complexes with non-cognate sRNA-target mRNA pairs while increasing cognate ternary complexes. The second mechanism relies on frequent RNA dissociation enabling the rapid cycling of sRNAs and target mRNAs among different Hfq complexes; this increases the probability the cognate ternary complex forms before the sRNAs and target mRNAs degrade. We further demonstrate that the performance of sRNAs in isolation is not predictive of their performance within a network. These findings highlight the importance of experimentally characterizing duplex formation in physiologically relevant contexts with multiple RNAs competing for Hfq. The model will provide a valuable framework for guiding and interpreting these experiments.


Asunto(s)
Fenómenos Fisiológicos Bacterianos , Proteína de Factor 1 del Huésped/metabolismo , Modelos Genéticos , ARN Bacteriano/metabolismo , Regulación Bacteriana de la Expresión Génica , Proteína de Factor 1 del Huésped/genética , Cinética , Unión Proteica , ARN Bacteriano/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transducción de Señal
13.
J Econ Entomol ; 105(4): 1115-29, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22928287

RESUMEN

Since 1993, the annual worldwide cost of diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), control has been routinely quoted to be US$1 billion. This estimate requires updating and incorporation of yield losses to reflect current total costs of the pest to the world economy. We present an analysis that estimates what the present costs are likely to be based on a set of necessary, but reasoned, assumptions. We use an existing climate driven model for diamondback moth distribution and abundance, the Food and Agriculture Organization country Brassica crop production data and various management scenarios to bracket the cost estimates. The "length of the string" is somewhere between US$1.3 billion and US$2.3 billion based on management costs. However, if residual pest damage is included then the cost estimates will be even higher; a conservative estimate of 5% diamondback moth-induced yield loss to all crops adds another US$2.7 billion to the total costs associated with the pest. A conservative estimate of total costs associated with diamondback moth management is thus US$4 billion-US$5 billion. The lower bound represents rational decision making by pest managers based on diamondback moth abundance driven by climate only. The upper estimate is due to the more normal practice of weekly insecticide application to vegetable crops and the assumption that canola (Brassica napus L.) is treated with insecticide at least once during the crop cycle. Readers can decide for themselves what the real cost is likely to be because we provide country data for further interpretation. Our analysis suggests that greater efforts at implementation of even basic integrated pest management would reduce insecticide inputs considerably, reducing negative environmental impacts and saving many hundreds of millions of dollars annually.


Asunto(s)
Brassica/parasitología , Control de Insectos/economía , Mariposas Nocturnas/fisiología , Animales , Brassica/economía , Internacionalidad , Modelos Biológicos
14.
World Neurosurg ; 158: e843-e855, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34838770

RESUMEN

OBJECTIVE: Increasing use of imaging is associated with increasing diagnoses of pituitary incidentalomas (PIs), which often do not require surgical or medical treatment. In this study, we evaluate U.S. incidence, epidemiology, and trends of pituitary adenomas (PAs) and PIs from 2004 to 2018. METHODS: A total of 50,220 PAs were selected from the SEER (Surveillance Epidemiology and End Results) 2020 submission. PIs that do not initially require surgical or medical treatment were filtered from PAs if they were best diagnostically confirmed by radiography, not indicated as prolactinomas in physician reports, not recommended surgery initially, and reported a correct tumor size. Age-adjusted incidence rates, patient demographics, tumor characteristics, trends over time, and differences between PAs and PIs were explored. RESULTS: Between 2004 and 2018, the incidence rates of PAs and PIs were 4.28 ± 0.04 and 1.53 ± 0.02 per 100,000 population, respectively. When observing changes from 2004 to 2018, a nearly 3-fold increase from 0.73 ± 0.05 to 2.00 ± 0.09 per 100,000 was observed for PIs. The proportion of PIs significantly increased from 24.91% of all PA diagnoses in 2004 to 42.07% in 2018 (P < 0.001). When comparing non-PI PAs with PIs, PIs were more commonly diagnosed in females (64.72% vs. 54.27%; P < 0.001) with microadenomas (61.68% vs. 13.37%; P < 0.001). CONCLUSIONS: Reports of increasing PAs in the United States are likely caused by an increase in diagnosing PIs. This result parallels findings from other countries. This national PI estimate may serve as a point of comparison for future studies investigating imaging and PI rates at individual institutions.


Asunto(s)
Adenoma , Neoplasias Hipofisarias , Prolactinoma , Adenoma/complicaciones , Femenino , Humanos , Incidencia , Neoplasias Hipofisarias/complicaciones , Neoplasias Hipofisarias/diagnóstico por imagen , Neoplasias Hipofisarias/epidemiología , Prolactinoma/complicaciones , Estados Unidos/epidemiología
15.
J Contam Hydrol ; 247: 103986, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35279484

RESUMEN

Two of the most important retention processes for per- and polyfluoroalkyl substances (PFAS) in groundwater likely are sorption and matrix diffusion. The objective of this study was to model concentration and mass discharge of one PFAS, perfluorooctane sulfonate (PFOS), with matrix diffusion processes incorporated using data from a highly chemically- and geologically-characterized site. When matrix diffusion is incorporated into the REMChlor-MD model for PFOS at this research site, it easily reproduces the field data for three key metrics (concentration, mass discharge, and total mass). However, the no-matrix diffusion model produced a much poorer match. Additionally, after about 40 years of groundwater transport, field data and the REMChlor-MD model both showed the majority (80%) of the measured PFOS mass that exited the source zones was located in downgradient low permeability zones due to matrix diffusion. As such, most of the PFOS mass is not available to immediately migrate downgradient via advection in the more permeable sands at this site, which has important implications for monitored natural attenuation (MNA). Plume expansion over the next 50 years is forecasted to be limited, from a 350-m plume length in 2017 to 550 m in 2070, as matrix diffusion will attenuate groundwater plumes by slowing their expansion. This phenomenon is important for constituents that do not degrade, such as PFOS, compared to those susceptible to degradation. Overall, this work shows that matrix diffusion is a relevant process in environmental PFAS persistence and slows the rate of plume expansion over time.


Asunto(s)
Ácidos Alcanesulfónicos , Fluorocarburos , Agua Subterránea , Difusión
16.
J Hazard Mater ; 424(Pt C): 127540, 2022 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-34763286

RESUMEN

Monitored Natural Attenuation (MNA) is a preferred remedy for sites contaminated with 1,4-dioxane due to its low cost and limited environmental impacts compared to active remediation. Having a robust estimate of the rate at which biodegradation occurs is an essential component of assessing MNA. In this study, an assay was developed using 14C-labeled 1,4-dioxane to measure rate constants for biodegradation based on accumulation of 14C products. Purification of the 14C-1,4-dioxane stock solution lowered the level of 14C impurities to below 1% of the total 14C activity. This enabled determination of rate constants in groundwater as low as 0.0021 yr-1, equating to a half-life greater than 300 years. Of the 54 groundwater samples collected from 10 sites in the US, statistically significant rate constants were determined with the 14C assay for 24. The median rate constant was 0.0138 yr-1 (half-life = 50 yr); the maximum rate constant was 0.367 yr-1 (half-life = 1.9 yr). The results confirmed that biodegradation of 1,4-dioxane is occurring at 9 of the 10 sites sampled, albeit with considerable variability in the level of activity. The specificity of the assay was confirmed using acetylene and the absence of oxygen to inhibit monooxygenases.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Biodegradación Ambiental , Dioxanos , Contaminantes Químicos del Agua/análisis
17.
J Hazard Mater ; 424(Pt D): 127736, 2022 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-34802822

RESUMEN

Options for remediating 1,4-dioxane at groundwater sites are limited due to the physical-chemical properties of this compound. The relevance of natural attenuation processes for 1,4-dioxane was investigated through data from field, lab, and modeling efforts. The objectives were to use multiple lines of evidence for 1,4-dioxane biodegradation to understand the prevalence of this activity and evaluate convergence between lines of evidence. A 14C-1,4-dioxane assay confirmed 1,4-dioxane biodegradation at 9 of 10 sites (median rate constant of 0.0105 yr-1 across wells). Site-wide rate constants were established using a calibrated fate and transport model at 8 sites (median = 0.075 yr-1). The 14C assay constants are likely more conservative, and variability in rates suggested that biodegradation at sites may be localized. Stable isotope fractionation was observed at 7 of 10 sites and served as another direct line of evidence of in situ biodegradation of 1,4-dioxane. This includes sites where indirect lines of evidence, including geochemical conditions or genetic biomarkers for degradation, would not necessarily have been supportive. This highlights the importance of collecting multiple lines of evidence to document 1,4-dioxane natural attenuation, and the widespread prevalence of biodegradation suggests that this process should be part of long-term management decisions.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Biodegradación Ambiental , Dioxanos , Prevalencia , Contaminantes Químicos del Agua/análisis
18.
Biomedicines ; 9(5)2021 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-33946142

RESUMEN

Pituitary adenomas are tumors that arise in the anterior pituitary gland. They are the third most common cause of central nervous system (CNS) tumors among adults. Most adenomas are benign and exert their effect via excess hormone secretion or mass effect. Clinical presentation of pituitary adenoma varies based on their size and hormone secreted. Here, we review some of the most common types of pituitary adenomas, their clinical presentation, and current diagnostic and therapeutic strategies.

19.
Biomedicines ; 9(3)2021 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-33810154

RESUMEN

The standard of care (SOC) for high-grade gliomas (HGG) is maximally safe surgical resection, followed by concurrent radiation therapy (RT) and temozolomide (TMZ) for 6 weeks, then adjuvant TMZ for 6 months. Before this SOC was established, glioblastoma (GBM) patients typically lived for less than one year after diagnosis, and no adjuvant chemotherapy had demonstrated significant survival benefits compared with radiation alone. In 2005, the Stupp et al. randomized controlled trial (RCT) on newly diagnosed GBM patients concluded that RT plus TMZ compared to RT alone significantly improved overall survival (OS) (14.6 vs. 12.1 months) and progression-free survival (PFS) at 6 months (PFS6) (53.9% vs. 36.4%). Outside of TMZ, there are four drugs and one device FDA-approved for the treatment of HGGs: lomustine, intravenous carmustine, carmustine wafer implants, bevacizumab (BVZ), and tumor treatment fields (TTFields). These treatments are now mainly used to treat recurrent HGGs and symptoms. TTFields is the only treatment that has been shown to improve OS (20.5 vs. 15.6 months) and PFS6 (56% vs. 37%) in comparison to the current SOC. TTFields is the newest addition to this list of FDA-approved treatments, but has not been universally accepted yet as part of SOC.

20.
Expert Opin Pharmacother ; 22(15): 1983-1994, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34219576

RESUMEN

Introduction: Despite decades of clinical trials utilizing conventional and novel therapeutics, the effective treatment of glioblastoma remains one of the most formidable challenges in oncology. Current standard of care includes surgery and chemoradiation. Synthetic pharmacotherapies continue to be explored as potential therapeutic options for glioblastoma patients.Areas covered: This study reviews synthetic pharmacotherapies that are currently under investigation in phase I-III clinical trials. The authors of this study highlight the mechanisms of action of the synthetic pharmacotherapy agents under investigation, outline the available evidence for their utility based on the literature, and summarize the current landscape.Expert opinion: Although warranting further investigation, the studies generally highlighted here have not shown remarkable changes in clinical benefits beyond what has already been established with radiochemotherapy. As we develop more synthetics, we will likely need to combine them with other synthetics to target multiple separate molecular pathways. There is considerable potential when this treatment strategy is guided by molecular profiling approaches which seek to stratify patients based on treatments that would be most efficacious for them.


Asunto(s)
Antineoplásicos , Neoplasias Encefálicas , Glioblastoma , Antineoplásicos/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Quimioradioterapia , Glioblastoma/tratamiento farmacológico , Humanos
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