scholarly journals Natural toxins: environmental contaminants calling for attention

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Hans Christian Bruun Hansen ◽  
Klara Hilscherova ◽  
Thomas D. Bucheli
Keyword(s):  
Environmental Fate ◽  
Current Knowledge ◽  
Wide Spectrum ◽  
Chemical Properties ◽  
Transport Modelling ◽  
Water Contaminants ◽  
Natural Toxin ◽  
Natural Toxins ◽  
Plant Densities ◽  
Current Knowledge Base

AbstractBiosynthetic toxic compounds from plants and cyanobacteria constitute a chemically diverse family of at least 20,000 compounds. Recent work with natural toxin databases and toxin characterization shows that the majority of natural toxins are polar and mobile, with toxicity ranging from low to very high, while persistence is highly variable. Natural toxins may be produced in high quantities—some exceeding 10 g/m2/year—resulting in high environmental loads. Recent phytotoxin monitoring indicates that one or more natural toxin is always present in a surface water sample, but that concentrations are highly variable often with pulses during rain events. Phytotoxins belong to many classes, but often with flavonoids and alkaloids dominating. Likewise, advanced monitoring discovers a wide spectrum of cyanobacterial metabolites that are released directly into surface waters during water blooms. Except of the few known cyanobacterial toxins, we have very limited info regarding their environmental fate and toxicity.The 16 papers in this article collection present examples of natural toxin occurrence, properties, fate and toxicity. The overarching conclusion is that natural toxins should be monitored and characterized regarding their risk potential, and that natural toxins of greatest expected risk should be evaluated as thoroughly as industrial xenobiotics. Cyanotoxins are well known water contaminants that should be removed for producing drinking water, while for phytotoxins the current knowledge base is very limited. We advocate to intensify research on natural toxins, and to address the evident knowledge gaps on natural toxin analysis/monitoring, physical–chemical properties and degradation/pathways, transport modelling, and toxicity. The complex and dynamic interplays between biotic and site conditions such as vegetation, toxic plant densities, climate, soil types, nutrients and radiation, play decisive roles for both biotoxin formation and fate. Environmental and toxicological research in biosynthesized compounds extends beyond natural toxins, with important perspectives for risk assessment of biopesticides, growth regulators and biomedicine (or biologicals collectively) produced by plants and microorganisms.

scholarly journals Factors Influencing the Private Involvement in Urban Rail Public-Private Partnership Projects in China

2017 ◽  
Vol 17 (1) ◽  
pp. 90-106 ◽  
Author(s):  
Yongjian Ke ◽  
Weiya Hao ◽  
Huiping Ding ◽  
Yingying Wang
Keyword(s):  
Influencing Factors ◽  
Current Knowledge ◽  
Group Discussion ◽  
Risk Allocation ◽  
Financial Model ◽  
Urban Rail ◽  
Current Knowledge Base ◽  
Private Investors ◽  
Fiscal Pressure

Private investors have been encouraged to participate in the development and operation of urban rail projects in China through Public-Private Partnerships (PPPs), given the fact that subnational governments are suffering from urgent development demands and severe fiscal pressure. However, there is no formal assessment to determine the private involvement in a PPP project. This problem is particularly critical in the sector of urban rail, in which the huge investment cannot rely on the private sector alone. This study hence aimed to uncover and identify the influencing factors. Multiple research methods, including content analysis, case study and focus group discussion were adopted to achieve the research purpose. Seven types of influencing factors were identified, including project financial model, government fiscal commitment, risk allocation, public accountability, efficiency considerations, policy and regulations, and organisational marketing strategies. The findings add to the current knowledge base by uncovering the drivers behind private involvement in a PPP project. They are also beneficial for industry practitioners as a basis/checklist to determine the private involvement.

scholarly journals Evolution of the Reaction and Alteration of Mudstone with Ordinary Portland Cement Leachates: Sequential Flow Experiments and Reactive-Transport Modelling

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1026
Author(s):  
Keith Bateman ◽  
Shota Murayama ◽  
Yuji Hanamachi ◽  
James Wilson ◽  
Takamasa Seta ◽  
...  
Keyword(s):  
Reactive Transport ◽  
Chemical Properties ◽  
Reactive Transport Modelling ◽  
Transport Modelling ◽  
General Sequence ◽  
Long Term Performance ◽  
Term Performance ◽  
Physical And Chemical ◽  
Flow Experiments

The construction of a repository for geological disposal of radioactive waste will include the use of cement-based materials. Following closure, groundwater will saturate the repository and the extensive use of cement will result in the development of a highly alkaline porewater, pH > 12.5; this fluid will migrate into and react with the host rock. The chemistry of the fluid will evolve over time, initially high [Na] and [K], evolving to a Ca-rich fluid, and finally returning to the groundwater composition. This evolving chemistry will affect the long-term performance of the repository, altering the physical and chemical properties, including radionuclide behaviour. Understanding these changes forms the basis for predicting the long-term evolution of the repository. This study focused on the determination of the nature and extent of the chemical reaction, as well as the formation and persistence of secondary mineral phases within a mudstone, comparing data from sequential flow experiments with the results of reactive transport modelling. The reaction of the mudstone with the cement leachates resulted in small changes in pH with the precipitation of calcium aluminium silicate hydrate (C-(A-)S-H) phases of varying compositions. As the system evolves, secondary C-(A-)S-H phases re-dissolve and are replaced by secondary carbonates. This general sequence was successfully simulated using reactive transport modelling.

scholarly journals Two-faced Janus: the dual role of macrophages in atherosclerotic calcification

2021 ◽  
Author(s):  
Olivia J Waring ◽  
Nikolaos T Skenteris ◽  
Erik A L Biessen ◽  
Marjo M P C Donners
Keyword(s):  
Current Knowledge ◽  
Wide Spectrum ◽  
Inflammatory Cells ◽  
Cell Types ◽  
Macrophage Phenotype ◽  
Phenotypic Changes ◽  
Direct Exposure ◽  
Stable Plaque ◽  
Mechanisms Of Development ◽  
The One

Abstract Calcification is an independent predictor of atherosclerosis-related cardiovascular events. Microcalcification is linked to inflamed, unstable lesions, in comparison to the fibrotic stable plaque phenotype generally associated with advanced calcification. This paradox relates to recognition that calcification presents in a wide spectrum of manifestations that differentially impact plaque’s fate. Macrophages, the main inflammatory cells in atherosclerotic plaque, have a multifaceted role in disease progression. They crucially control the mineralization process, from microcalcification to the osteoid metaplasia of bone-like tissue. It is a bilateral interaction that weighs heavily on the overall plaque fate but remains rather unexplored. This review highlights current knowledge about macrophage phenotypic changes in relation to and interaction with the calcifying environment. On the one hand, macrophage-led inflammation kickstarts microcalcification through a multitude of interlinked mechanisms, which in turn stimulates phenotypic changes in vascular cell types to drive microcalcification. Macrophages may also modulate the expression/activity of calcification inhibitors and inducers, or eliminate hydroxyapatite nucleation points. Contrarily, direct exposure of macrophages to an early calcifying milieu impacts macrophage phenotype, with repercussions for plaque progression and/or stability. Macrophages surrounding macrocalcification deposits show a more reparative phenotype, modulating extracellular matrix, and expressing osteoclast genes. This phenotypic shift favours gradual displacement of the pro-inflammatory hubs; the lipid necrotic core, by macrocalcification. Parallels to bone metabolism may explain many of these changes to macrophage phenotype, with advanced calcification able to show homeostatic osteoid metaplasia. As the targeted treatment of vascular calcification developing in atherosclerosis is thus far severely lacking, it is crucial to better understand its mechanisms of development.

A quantitative speciation model for the adsorption of organic pollutants on activated carbon

2013 ◽  
Vol 68 (6) ◽  
pp. 1370-1376 ◽  
Author(s):  
M. Grivé ◽  
D. García ◽  
C. Domènech ◽  
L. Richard ◽  
I. Rojo ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Organic Pollutants ◽  
Current Knowledge ◽  
Quantitative Description ◽  
High Capacity ◽  
Chemical Properties ◽  
Quantitative Model ◽  
Surface Groups ◽  
Potentiometric Titrations ◽  
Chemical Groups

Granular activated carbon (GAC) is commonly used as adsorbent in water treatment plants given its high capacity for retaining organic pollutants in aqueous phase. The current knowledge on GAC behaviour is essentially empirical, and no quantitative description of the chemical relationships between GAC surface groups and pollutants has been proposed. In this paper, we describe a quantitative model for the adsorption of atrazine onto GAC surface. The model is based on results of potentiometric titrations and three types of adsorption experiments which have been carried out in order to determine the nature and distribution of the functional groups on the GAC surface, and evaluate the adsorption characteristics of GAC towards atrazine. Potentiometric titrations have indicated the existence of at least two different families of chemical groups on the GAC surface, including phenolic- and benzoic-type surface groups. Adsorption experiments with atrazine have been satisfactorily modelled with the geochemical code PhreeqC, assuming that atrazine is sorbed onto the GAC surface in equilibrium (log Ks = 5.1 ± 0.5). Independent thermodynamic calculations suggest a possible adsorption of atrazine on a benzoic derivative. The present work opens a new approach for improving the adsorption capabilities of GAC towards organic pollutants by modifying its chemical properties.

Clinical Management of Obsessive-Compulsive and Related Disorders

2017 ◽  
Author(s):  
Samuel R Chamberlain
Keyword(s):  
Body Dysmorphic Disorder ◽  
Current Knowledge ◽  
Assessment Tools ◽  
Future Research ◽  
Obsessive Compulsive ◽  
Compulsive Disorder ◽  
Medical Issues ◽  
Evidence Based Treatments ◽  
Current Knowledge Base ◽  
Hair Pulling Disorder

Obsessive-compulsive and related disorders (OCRDs) now have their own category in the Diagnostic and Statistical Manual of Mental Disorders, fifth edition. Disorders currently classified as OCRDs are obsessive-compulsive disorder, trichotillomania (hair pulling disorder), excoriation (skin picking) disorder, hoarding disorder, and body dysmorphic disorder. Collectively, the OCRDs are prevalent, cause considerable functional impairment, and are often overlooked by clinicians. This review surveys current definitions and diagnosis of OCRDs, highlighting recommended assessment tools, differential diagnoses, and medical issues. The heritability of OCRDs is examined, based on available twin data, along with implicated genetic factors. Neurobiological understanding of OCRDs is outlined, focusing on dysregulation of habit generation and top-down response control corticostriatal pathways. The review then highlights evidence-based treatments for OCRDs, which differ considerably between individual disorders. Treatment guidance includes descriptions of target medication doses and therapy content. Lastly, limitations in the current knowledge base for OCRDs are reviewed, with implications for future research directions. This review contains 1 figure, 7 tables, and 40 references. Key words: compulsivity, dopamine, glutamate, impulsivity, screening for OCD, serotonin 

Recruiting and Engaging Men as Fathers in Social Work Practice

2014 ◽  
pp. 235-260
Author(s):  
Joseph Fleming ◽  
Andrew King ◽  
Tara Hunt
Keyword(s):  
Social Work ◽  
Social Workers ◽  
Child Protection ◽  
Current Knowledge ◽  
Social Work Students ◽  
Work Practice ◽  
Social Work Practice ◽  
Research Literature ◽  
Engaging Men ◽  
Current Knowledge Base

Evidence in the research literature suggests that men are usually not engaged by social workers, particularly in child welfare and child protection settings. Mothers also tend to become the focus of intervention, even when there is growing evidence that men can take an active and important role in a child's development in addition to providing support to the mother and family. Whilst there have been some promising developments in including men in social work practice internationally, there remains a gap in the research regarding the engagement of men as fathers in Australia. Given the growing relevance of the topic of fathers, the purpose of this chapter is to add to the current knowledge base, to support social work students and practitioners to engage with men in their role as fathers, and to offer an evidence-based practice model that may assist social workers in their work with men as fathers.

The Important Role of Lipids in Cognitive Impairment

2011 ◽  
pp. 206-211
Author(s):  
Yu Jia ◽  
Zheng Chen ◽  
Jiangyang Lu ◽  
Liu Tingting ◽  
Zhou Liang ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Memory Function ◽  
Pyramidal Cells ◽  
Cholesterol Homeostasis ◽  
Neonatal Lethality ◽  
Somatic Gene ◽  
Current Knowledge Base ◽  
Somatic Gene Transfer ◽  
The Brain

The current knowledge base on circulating serum and plasma risk factors of the cognitive decline of degenerative Alzheimer’s Disease is linked to cholesterol homeostasis and lipoprotein disturbances (i.e., total cholesterol, 24S-hydroxy-cholesterol, lipoprotein(a), or apolipoprotein E. Lipoprotein lipase (LPL) is also expressed in the brain, with the highest levels found in the pyramidal cells of the hippocampus, suggesting a possible role for LPL in the regulation of cognitive function. Little is currently known, however, about the specific role of LPL in the brain. The authors of this chapter have generated an LPL-deficient mouse model that was rescued from neonatal lethality by somatic gene transfer. The levels of the presynaptic marker synaptophysin were reduced in the hippocampus while the levels of the post-synaptic marker PSD-95 remained unchanged in the LPL-deficient mice. The decreased frequency of mEPSC in LPL-deficient neurons indicated that the number of presynaptic vesicles was decreased, which was consistent with the decreases observed in the numbers of total vesicles and docking vesicles. These findings indicate that LPL plays an important role in learning and memory function, possibly by influencing presynaptic function.

scholarly journals MiT Family Translocation Renal Cell Carcinoma: from the Early Descriptions to the Current Knowledge

Cancers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1110 ◽  
Author(s):  
Anna Caliò ◽  
Diego Segala ◽  
Enrico Munari ◽  
Matteo Brunelli ◽  
Guido Martignoni
Keyword(s):  
Renal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Renal Cell ◽  
Clinical Course ◽  
Current Knowledge ◽  
Wide Spectrum ◽  
Cathepsin K ◽  
World Health ◽  
Epithelioid Angiomyolipoma ◽  
Immunohistochemical Markers

The new category of MiT family translocation renal cell carcinoma has been included into the World Health Organization (WHO) classification in 2016. The MiT family translocation renal cell carcinoma comprises Xp11 translocation renal cell carcinoma harboring TFE3 gene fusions and t(6;11) renal cell carcinoma harboring TFEB gene fusion. At the beginning, they were recognized in childhood; nevertheless, it has been demonstrated that these neoplasms can occur in adults as well. In the nineties, among Xp11 renal cell carcinoma, ASPL, PRCC, and SFPQ (PSF) were the first genes recognized as partners in TFE3 rearrangement. Recently, many other genes have been identified, and a wide spectrum of morphologies has been described. For this reason, the diagnosis may be challenging based on the histology, and the differential diagnosis includes the most common renal cell neoplasms and pure epithelioid PEComa/epithelioid angiomyolipoma of the kidney. During the last decades, many efforts have been made to identify immunohistochemical markers to reach the right diagnosis. To date, staining for PAX8, cathepsin K, and melanogenesis markers are the most useful identifiers. However, the diagnosis requires the demonstration of the chromosomal rearrangement, and fluorescent in situ hybridization (FISH) is considered the gold standard. The outcome of Xp11 translocation renal cell carcinoma is highly variable, with some patients surviving decades with indolent disease and others dying rapidly of progressive disease. Despite most instances of t(6;11) renal cell carcinoma having an indolent clinical course, a few published cases demonstrate aggressive behavior. Recently, renal cell carcinomas with TFEB amplification have been described in connection with t(6;11) renal cell carcinoma. Those tumors appear to be associated with a more aggressive clinical course. For the aggressive cases of MiT family translocation carcinoma, the optimal therapy remains to be determined; however, new target therapies seem to be promising, and the search for predictive markers is mandatory.

scholarly journals Thyroid disorders in subfertility and early pregnancy

2020 ◽  
Vol 11 ◽  
pp. 204201882094585
Author(s):  
Samantha Anandappa ◽  
Mamta Joshi ◽  
Lukasz Polanski ◽  
Paul V. Carroll
Keyword(s):  
Pregnant Women ◽  
Thyroid Function ◽  
Current Knowledge ◽  
Thyroid Autoimmunity ◽  
Thyroid Disorders ◽  
Thyroid Function Tests ◽  
Increased Risk ◽  
Hormone Use ◽  
Current Knowledge Base ◽  
In Pregnancy

Disorders of thyroid function are common in pregnancy and have implications for foetal and maternal health. Thyroid autoimmunity, as evidenced by the presence of elevated levels of anti-thyroid antibodies (anti-TPO and anti-Tg antibodies) is associated with an increased risk of miscarriage, though the mechanism remains poorly understood. There has been considerable focus on the implications and optimal management of pregnant women with thyroid disease, especially those undergoing assisted reproduction. Pregnancy results in significant changes in thyroid physiology and these need to be understood by clinicians involved in the care of pregnant women. Guidelines for the use of thyroxine and target thyroid function tests have been produced by international bodies but it is recognised that these predominantly reflect expert opinion rather than established evidence-based practice. Importantly a number of key clinical trials have been performed to aid understanding, particularly of the consequences of hypothyroidism for mother and baby, and the effectiveness of thyroid hormone use in autoimmune and subclinical hypothyroidism. This review summarises the current knowledge base and guidance for practice relating to thyroid disorders in pregnancy and subfertility.

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