The Role of Plant–Microbe Interactions and Their Exploitation for Phytoremediation of Air Pollutants

Since air pollution has been linked to a plethora of human health problems, strategies to improve air quality are indispensable. Despite the complexity in composition of air pollution, phytoremediation was shown to be effective in cleaning air. Plants are known to scavenge significant amounts of air pollutants on their aboveground plant parts. Leaf fall and runoff lead to transfer of (part of) the adsorbed pollutants to the soil and rhizosphere below. After uptake in the roots and leaves, plants can metabolize, sequestrate and/or excrete air pollutants. In addition, plant-associated microorganisms play an important role by degrading, detoxifying or sequestrating the pollutants and by promoting plant growth. In this review, an overview of the available knowledge about the role and potential of plant–microbe interactions to improve indoor and outdoor air quality is provided. Most importantly, common air pollutants (particulate matter, volatile organic compounds and inorganic air pollutants) and their toxicity are described. For each of these pollutant types, a concise overview of the specific contributions of the plant and its microbiome is presented. To conclude, the state of the art and its related future challenges are presented.     

Physical and electrochemical characteristics of supercapacitors based on carbide derived carbon electrodes in aqueous electrolytes

FIB-SEM, XPS and gas adsorption methods have been used for the characterisation of physical properties of microporous carbide derived carbon electrodes prepared from Mo₂C at 600 °C (noted as CDC-Mo₂C). Cyclic voltammetry, constant current charge/discharge, and electrochemical impedance spectroscopy have been applied to establish the electrochemical characteristics for supercapacitors consisting of the 1 M Na₂SO₄, KOH, tetraethyl ammonium iodide or 6 M KOH aqueous electrolyte and CDC-Mo₂C electrodes. The N₂ sorption values obtained have been correlated with electrochemical characteristics for supercapacitors in various aqueous electrolytes. The maximum gravimetric energy, E_max, and gravimetric power, P_max, for supercapacitors (taking into consideration the active material weight) have been obtained at cell voltage 0.9 V for 6 M KOH aqueous supercapacitor (E_max = 5.7 Wh kg⁻¹ and P_max = 43 kW kg⁻¹). For 1 M TEAI based SC somewhat higher E_max (6.2 Wh kg⁻¹) and comparatively low P_max (7.0 kW kg⁻¹) have been calculated.     

Specificity of P3 event-related potential reactivity to alcohol cues in individuals low in alcohol sensitivity.

Recent research using event-related potentials (ERPs) has shown that individuals low in alcohol sensitivity show increased P3 reactivity to alcohol cues (Bartholow, Henry, & Lust, 2007). The current research sought to test the specificity of this effect by including other arousing cues in addition to alcohol, and by controlling for individual differences in trait impulsivity. Forty-seven participants varying in self-reported alcohol sensitivity completed a visual oddball task including neutral, arousing (erotic and adventure-related), and beverage-related images while ERPs were recorded. Low-sensitivity participants showed increased P3 reactivity to alcohol cues relative to their high-sensitivity peers. However, P3 amplitude elicited by all other targets did not differ as a function of alcohol sensitivity levels. Differences in impulsivity and recent alcohol consumption did not account for sensitivity group differences in alcohol cue reactivity. These results point to the specific motivational salience of alcohol cues to individuals at risk for alcohol problems because of low alcohol sensitivity and suggest that P3 reactivity to alcohol cues could be a new endophenotype for alcohol use disorder risk. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optically stimulated luminescence of some thermoluminescent detectors as an indicator of absorbed radiation dose

Stimulation spectra of several TLD materials in the short-wave spectral region are measured using the optically stimulated afterglow (OSA) method for determination of absorbed dose. Optical stimulation spectra are studied in the region of wavelengths lower than those of emission spectra. The effective optical stimulation hands have been found for examined materials in the regions of wavelengths which overlap with fluorescence excitation bands. Application of short-wave OSA bands for determination of absorbed dose is analysed.     

Endothelial Contribution to Warfarin-Induced Arterial Media Calcification in Mice

Arterial media calcification (AMC) is predominantly regulated by vascular smooth muscle cells (VSMCs), which transdifferentiate into pro-calcifying cells. In contrast, there is little evidence for endothelial cells playing a role in the disease. The current study investigates cellular functioning and molecular pathways underlying AMC, respectively by, an ex vivo isometric organ bath set-up to explore the interaction between VSMCs and ECs and quantitative proteomics followed by functional pathway interpretation. AMC development, which was induced in mice by dietary warfarin administration, was proved by positive Von Kossa staining and a significantly increased calcium content in the aorta compared to that of control mice. The ex vivo organ bath set-up showed calcified aortic segments to be significantly more sensitive to phenylephrine induced contraction, compared to control segments. This, together with the fact that calcified segments as compared to control segments, showed a significantly smaller contraction in the absence of extracellular calcium, argues for a reduced basal NO production in the calcified segments. Moreover, proteomic data revealed a reduced eNOS activation to be part of the vascular calcification process. In summary, this study identifies a poor endothelial function, next to classic pro-calcifying stimuli, as a possible initiator of arterial calcification.     

Synthesis and characterisation of nanoporous carbide-derived carbon by chlorination of vanadium carbide

Nanoporous carbide-derived carbon (CDC) was synthesised from vanadium carbide (VC) powder via gas phase chlorination in the temperature range from 500 to 1100 °C. The XRD analysis of nanoporous carbon powder samples was carried out to investigate the structural changes (graphitisation) of nanoporous carbons synthesised. The first-order Raman spectra showed the absorption peak at ∼1582 cm⁻¹ and the disorder-induced (D) peak at ∼1345 cm⁻¹. The low-temperature N₂ adsorption experiments were performed and a specific surface area up to 1305 m² g⁻¹ and total pore volume up to 0.66 cm³ g⁻¹ were obtained.     

Random amplified polymorphic DNA (RAPD) sequences as markers for canine genetic studies

Our knowledge of the concentration of growth factors in growing bone is limited. In the present study, we examined the developmental changes in the concentrations of insulin-like growth factor I (IGF-I) and transforming growth factor beta (TGF-beta) in the rat femur between weanling and maturity. We show that during the rapid growth phase there is a continuous rise in bone matrix IGF-I and TGF-beta in all compartments of the femoral bone. The association between IGF-I and TGF-beta is not only temporal, but with few exceptions is also observed within the animals of each age class. These data support the hypothesis that IGF-I and TGF-beta play an important role in the growth-associated accumulation of bone mass.     

Identification of Codon 146 KRAS Variants in Isolated Epidermal Nevus and Multiple Lesions in Oculoectodermal Syndrome: Confirmation of the Phenotypic Continuum of Mosaic RASopathies

Mosaic RASopathies are a molecularly heterogeneous group of (neuro)cutaneous syndromes with high phenotypical variability. Postzygotic variants in KRAS have been described in oculoectodermal syndrome (OES), encephalocraniocutaneous lipomatosis (ECCL) and epidermal nevus syndrome (ENS). This study confirms the continuum of mosaic neurocutaneous RASopathies showing codon 146 KRAS variants in an individual with OES and, for the first time, in an individual with (isolated) epidermal nevus. The presence of a nevus psiloliparus in individuals with OES indicates that this finding is not specific for ECCL and highlights the phenotypical overlap between ECCL and OES. The presence of the somatic KRAS variant in the nevus psiloliparus resolves the underlying molecular etiology of this fatty-tissue nevus. In addition, this finding refutes the theory of non-allelic twin-spotting as an underlying hypothesis to explain the concurrent presence of two different mosaicisms in one individual. The identification of codon 146 KRAS variants in isolated epidermal nevus introduces a new hot spot for this condition, which is useful for increasing molecular genetic testing using targeted gene sequencing panels.     

Influencing cocoa flavour using Pichia kluyveri and Kluyveromyces marxianus in a defined mixed starter culture for cocoa fermentation

The potential impact of aromatic and pectinolytic yeasts on cocoa flavour was investigated using two defined mixed starter cultures encompassing strains of Pichia kluyveri and Kluyveromyces marxianus for inoculating cocoa beans in small scale tray fermentations. Samples for microbial and metabolite analysis were collected at 12–24 hour intervals during 120 h of fermentation. Yeast isolates were grouped by (GTG)₅-based rep-PCR fingerprinting and identified by sequencing of the D1/D2 region of the 26S rRNA gene and the actin gene. Pulsed Field Gel Electrophoresis (PFGE) was conducted on isolates belonging to the species P. kluyveri and K. marxianus to verify strain level identity with the inoculated strains. Furthermore, Denaturing Gradient Gel Electrophoresis (DGGE) was performed to follow yeast and bacterial dynamics over time including the presence of the bacterial inoculum consisting of Lactobacillus fermentum and Acetobacter pasteurianus. Yeast cell counts peaked after 12 h of fermentation with the predominant species being identified as Hanseniaspora opuntiae and Hanseniaspora thailandica. P. kluyveri and K. marxianus were found to compose 9.3% and 13.5% of the yeast population, respectively, after 12 h of fermentation whilst PFGE showed that ~ 88% of all P. kluyveri isolates and 100% of all K. marxianus isolates were identical to the inoculated strains. Despite never being the dominant yeast species at any stage of fermentation, the un-conched chocolates produced from the two inoculated fermentations were judged by sensory analysis to differ in flavour profile compared to the spontaneously fermented control. This could indicate that yeasts have a greater impact on the sensory qualities of cocoa than previously assumed.