How weathering might intensify the toxicity of spilled crude oil in marine environments.

Crude oils are highly complex mixtures containing many toxic compounds for organisms. While their level of toxicity in a marine environment depends on many parameters, one of the main factors is their composition. After oil spills, their compositions are significantly changed, so it changes the toxicity.

Marine phytoplankton responses to oil and dispersant exposures: Knowledge gained since the Deepwater Horizon oil spill.

The Deepwater Horizon oil spill of 2010 brought the ecology and health of the Gulf of Mexico to the forefront of the public's and scientific community's attention. Not only did we need a better understanding of how this oil spill impacted the Gulf of Mexico ecosystem, but we also needed to apply this knowledge to help assess impacts from perturbations in the region and guide future response actions. Phytoplankton represent the base of the food web in oceanic systems.

Trimethyl 4,4',4''-(ethene-1,1,2-tri-yl)tribenzoate.

The title compound, CHO, is formed as the major product from the reaction between -1,2-bis-(pinacolatoboron)-1,2-bis-(4-methyl-carb-oxy-phen-yl)ethene and excess methyl 4-iodo-benzoate in basic DMSO using a palladium catalyst at 80°C Suzuki coupling followed by protodeboronation. Crystals were grown by slow evaporation of a hexa-nes solution at room temperature.

Degradation of Bisphenol A in Natural and Artificial Marine and Freshwaters in Turkey.

Bisphenol A (BPA), one of the important synthetic chemicals, has been produced at high volumes since the 1960s. These chemicals are commonly detected in the marine and freshwater environments; however, their transformation in aquatic environments depends on many parameters. This study aims to investigate the degradation of BPA in marine and freshwaters under different conditions in terms of microbial degradation, photodegradation, and temperature effect.

Temporal and Spatial Distributions of Bisphenol A in Marine and Freshwaters in Turkey.

Bisphenol A (BPA), a chemical component used in the manufacture of plastics, is commonly introduced to and detected in aquatic environments. This is the first study conducted to understand the distribution of BPA in the marine and freshwaters of Turkey. The purpose of this study is to report BPA concentrations measured from a time-series conducted in coastal waters of Erdemli and regional rivers located in the northeastern Mediterranean region.

Assessment of trophic status of the northeastern Mediterranean coastal waters: eutrophication classification tools revisited.

The Eastern Mediterranean and its Cilician Basin offshore waters have oligotrophic features with low nutrient concentrations, low primary production, and high water transparency. However, the wide shelf area of the Cilician Basin is subject to contaminated river inflows with enhanced nutrient loads and direct discharges of urban wastewaters of southern Turkey, leading to develop local eutrophic/mesotrophic conditions in the inner sites of Mersin and Iskenderun Bays on the Cilician Basin. For the assessment of changing trophic status of the coastal and the bay water bodies under anthropogenic pressures since the 1980s, five extensive field studies were performed in summer and winter periods of 2014, 2015, and 2016.

Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins.

Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.

Induction of reactive oxygen species in marine phytoplankton under crude oil exposure.

Exposure of phytoplankton to the water-accommodated fraction of crude oil can elicit a number of stress responses, but the mechanisms that drive these responses are unclear. South Louisiana crude oil was selected to investigate its effects on population growth, chlorophyll a (Chl a) content, antioxidative defense, and lipid peroxidation, for the marine diatom, Ditylum brightwellii, and the dinoflagellate, Heterocapsa triquetra, in laboratory-based microcosm experiments. The transcript levels of several possible stress-responsive genes in D.

Responses of sympatric Karenia brevis, Prorocentrum minimum, and Heterosigma akashiwo to the exposure of crude oil.

Impacts of the Deepwater Horizon oil spill on phytoplankton, particularly, the tolerability and changes to the toxin profiles of harmful toxic algal species remain unknown. The degree to which oil-affected sympatric Karenia brevis, Prorocentrum minimum, and Heterosigma akashiwo, all of which are ecologically important species in the Gulf of Mexico, was investigated. Comparison of their tolerability to that of non-toxic species showed that the toxin-production potential of harmful species does not provide a selective advantage.

Relative phytoplankton growth responses to physically and chemically dispersed South Louisiana sweet crude oil.

We conducted controlled laboratory exposure experiments to assess the toxic effects of water-accommodated fractions (WAFs) of South Louisiana sweet crude oil on five phytoplankton species isolated from the Gulf of Mexico. Experiments were conducted with individual and combinations of the five phytoplankton species to determine growth inhibitions to eight total petroleum hydrocarbon (TPH) equivalent concentrations ranging from 461 to 7,205 ppb. The composition and concentration of crude oil were altered by physical and chemical processes and used to help evaluate crude oil toxicity.

Distinct responses of Gulf of Mexico phytoplankton communities to crude oil and the dispersant corexit(®) Ec9500A under different nutrient regimes.

This study examines the potential effects of exposure to South Louisiana sweet crude oil (LSC), Corexit(®) EC9500A, and dispersed oil on enclosed phytoplankton communities under different nutrient regimes. Three distinct microcosm experiments were conducted for 10 days to assess changes to the structure of natural communities from the Gulf of Mexico as quantified by temporal changes in the biomasses of different phytoplankton groups. Concentration of NO3, Si and PO4 were 0.

Can crude oil toxicity on phytoplankton be predicted based on toxicity data on benzo(a)pyrene and naphthalene?

Polycyclic aromatic hydrocarbons (PAHs), which are major components of crude oil, are responsible in large part for the toxicity of crude oil to phytoplankton. This study addressed the following question. Can reliable predictions of the aquatic toxicity of crude oil, a multi-component mixture, be described from toxicity data on individual PAH compounds? Naphthalene, the most abundant PAH compound, and benzo(a)pyrene, a highly toxic PAH compound, were selected as model compounds to quantify toxicity of crude oil on two phytoplankton species, Ditylum brightwellii and Heterocapsa triquetra, by analyzing the effects of different concentrations of these PAHs on growth rate.

Ultra-rapid absorption of recombinant human insulin induced by zinc chelation and surface charge masking.

Background: In order to enhance the absorption of insulin following subcutaneous injection, excipients were selected to hasten the dissociation rate of insulin hexamers and reduce their tendency to reassociate postinjection. A novel formulation of recombinant human insulin containing citrate and disodium ethylenediaminetetraacetic acid (EDTA) has been tested in clinic and has a very rapid onset of action in patients with diabetes. In order to understand the basis for the rapid insulin absorption, in vitro experiments using analytical ultracentrifugation, protein charge assessment, and light scattering have been performed with this novel human insulin formulation and compared with a commercially available insulin formulation [regular human insulin (RHI)].