Green (vegetated) roofs are emerging as practical strategies to improve the environmental quality of cities. However, the impact of green roofs on the storm water quality remains a topic of concern ...to city planners and environmental policy makers. This study investigated whether green roofs act as a source or a sink of various metals (Na, K, Ca, Mg, Al, Fe, Cu, Cd, Pb, Zn, Mn, Cr, Ni, Li and Co), inorganic anions (
NO
3
−
,
NO
2
−
,
PO
4
3
−
,
SO
4
2
−
, Cl
−, F
− and Br
−) and cation (
NH
4
+
). A series of green roof assemblies were constructed. Four different real rain events and several artificial rain events were considered for the study. Results showed that concentrations of most of the chemical components in runoff were highest during the beginning of rain events and subsided in the subsequent rain events. Some of the important components present in the runoff include Na, K, Ca, Mg, Li, Fe, Al, Cu,
NO
3
−
,
PO
4
3
−
and
SO
4
2
−
. However, the concentration of these chemical components in the roof runoff strongly depends on the nature of substrates used in the green roof and the volume of rain. Based on the USEPA standards for freshwater quality, we conclude that the green roof used in this study is reasonably effective except that the runoff contains significant amounts of
NO
3
−
and
PO
4
3
−
.
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► This study investigated the quality of runoff from green roofs. ► Several rain events were used for the field-based investigation. ► Different physico-chemical parameters along with metals and nutrients were assessed for green roof runoff quality. ► Runoffs from green roofs were found to comprise high concentrations of nitrate and phosphate.
In neurodegenerative diseases, debris of dead neurons are thought to trigger glia-mediated neuroinflammation, thus increasing neuronal death. Here we show that the expression of neurotoxic proteins ...associated with these diseases in microglia alone is sufficient to directly trigger death of naive neurons and to propagate neuronal death through activation of naive astrocytes to the A1 state. Injury propagation is mediated, in great part, by the release of fragmented and dysfunctional microglial mitochondria into the neuronal milieu. The amount of damaged mitochondria released from microglia relative to functional mitochondria and the consequent neuronal injury are determined by Fis1-mediated mitochondrial fragmentation within the glial cells. The propagation of the inflammatory response and neuronal cell death by extracellular dysfunctional mitochondria suggests a potential new intervention for neurodegeneration-one that inhibits mitochondrial fragmentation in microglia, thus inhibiting the release of dysfunctional mitochondria into the extracellular milieu of the brain, without affecting the release of healthy neuroprotective mitochondria.
Out of the myriad of complications associated with septic shock, septic-associated encephalopathy (SAE) carries a significant risk of morbidity and mortality. Blood-brain-barrier (BBB) impairment, ...which subsequently leads to increased vascular permeability, has been associated with neuronal injury in sepsis. Thus, preventing BBB damage is an attractive therapeutic target. Mitochondrial dysfunction is an important contributor of sepsis-induced multi-organ system failure. More recently, mitochondrial dysfunction in endothelial cells has been implicated in mediating BBB failure in stroke, multiple sclerosis and in other neuroinflammatory disorders. Here, we focused on Drp1-mediated mitochondrial dysfunction in endothelial cells as a potential target to prevent BBB failure in sepsis.
We used lipopolysaccharide (LPS) to induce inflammation and BBB disruption in a cell culture as well as in murine model of sepsis. BBB disruption was assessed by measuring levels of key tight-junction proteins. Brain cytokines levels, oxidative stress markers, and activity of mitochondrial complexes were measured using biochemical assays. Astrocyte and microglial activation were measured using immunoblotting and qPCR. Transwell cultures of brain microvascular endothelial cells co-cultured with astrocytes were used to assess the effect of LPS on expression of tight-junction proteins, mitochondrial function, and permeability to fluorescein isothiocyanate (FITC) dextran. Finally, primary neuronal cultures exposed to LPS were assessed for mitochondrial dysfunction.
LPS induced a strong brain inflammatory response and oxidative stress in mice which was associated with increased Drp1 activation and mitochondrial localization. Particularly, Drp1-(Fission 1) Fis1-mediated oxidative stress also led to an increase in expression of vascular permeability regulators in the septic mice. Similarly, mitochondrial defects mediated via Drp1-Fis1 interaction in primary microvascular endothelial cells were associated with increased BBB permeability and loss of tight-junctions after acute LPS injury. P110, an inhibitor of Drp1-Fis1 interaction, abrogated these defects, thus indicating a critical role for this interaction in mediating sepsis-induced brain dysfunction. Finally, LPS mediated a direct toxic effect on primary cortical neurons, which was abolished by P110 treatment.
LPS-induced impairment of BBB appears to be dependent on Drp1-Fis1-mediated mitochondrial dysfunction. Inhibition of mitochondrial dysfunction with P110 may have potential therapeutic significance in septic encephalopathy.
Mitochondrial dynamics, involving a balance between fusion and fission, regulates mitochondrial quality and number. Increasing evidence suggests that dysfunctional mitochondria play a role in ...Alzheimer's disease (AD). We observed that Drp1 interaction with one of the adaptors, Fis1, is significantly increased in Aβ-treated neurons and AD patient-derived fibroblasts. P110, a seven-amino acid peptide, which specifically inhibits Drp1/Fis1 interaction without affecting the interaction of Drp1 with its other adaptors, attenuated Aβ
-induced mitochondrial recruitment of Drp1 and prevented mitochondrial structural and functional dysfunction in cultured neurons, in cells expressing mutant amyloid precursor protein (KM670/671NL), and in five different AD patient-derived fibroblasts. Importantly, sustained P110 treatment significantly improved behavioral deficits, and reduced Aβ accumulation, energetic failure and oxidative stress in the brain of the AD mouse model, 5XFAD. This suggests that Drp1/Fis1 interaction and excessive mitochondrial fission greatly contribute to Aβ-mediated and AD-related neuropathology and cognitive decline. Therefore, inhibiting excessive Drp1/Fis1-mediated mitochondrial fission may benefit AD patients.
Mitochondrial dysfunction is a key contributor to septic cardiomyopathy. Although recent literature implicates dynamin related protein 1 (Drp1) and its mitochondrial adaptor fission 1 (Fis1) in the ...development of pathologic fission and mitochondrial failure in neurodegenerative disease, little is known about the role of Drp1/Fis1 interaction in the context of sepsis-induced cardiomyopathy. Our study tests the hypothesis that Drp1/Fis1 interaction is a major driver of sepsis-mediated pathologic fission, leading to mitochondrial dysfunction in the heart.
H9C2 cardiomyocytes were treated with lipopolysaccharide (LPS) to evaluate changes in mitochondrial membrane potential, oxidative stress, cellular respiration, and mitochondrial morphology. Balb/c mice were treated with LPS, cardiac function was measured by echocardiogaphy, and mitochondrial morphology determined by electron microscopy (EM). Drp1/Fis1 interaction was inhibited by P110 to determine whether limiting mitochondrial fission can reduce LPS-induced oxidative stress and cardiac dysfunction.
LPS-treated H9C2 cardiomyocytes demonstrated a decrease in mitochondrial respiration followed by an increase in mitochondrial oxidative stress and a reduction in membrane potential. Inhibition of Drp1/Fis1 interaction with P110 attenuated LPS-mediated cellular oxidative stress and preserved membrane potential. In vivo, cardiac dysfunction in LPS-treated mice was associated with increased mitochondrial fragmentation. Treatment with P110 reduced cardiac mitochondrial fragmentation, prevented decline in cardiac function, and reduced mortality.
Sepsis decreases cardiac mitochondrial respiration and membrane potential while increasing oxidative stress and inducing pathologic fission. Treatment with P110 was protective in both in vitro and in vivo models of septic cardiomyopathy, suggesting a key role of Drp1/Fis1 interaction, and a potential target to reduce its morbidity and mortality.
Barium - Strontium Titanate (BST), a ternary ceramic with high dielectric tunability has been the centre of attraction due to its proficiency in dynamic random-access memory (DRAM), tunable microwave ...application, etc. Ba
0.6
Sr
0.4
Ni
x
Ti
1-x
O
3
where
x
= 0.00, 0.02 and 0.04 were studied for its structural, optical and magnetodielectric properties. The samples were synthesized by standard solid state reaction method. Structural characterizations of BST performed using X-ray diffraction (XRD) showcase that it has simple cubic perovskite symmetry. Optical properties were studied using diffused reflectance spectroscopy. The optical band gap of
x
= 0.00, 0.02 and 0.04 samples were found to be 2.86 eV, 3.05 eV and 2.98 eV, respectively. Dilute doping of Ni in pristine BST changes the magnetodielectric (MD) behaviour of the sample considerably. The MD response, investigated under a perpendicular uniform magnetic fields of 0.58 T showed noticeable variations in the MD values and are attributed to the magnetostriction effect and the interfacial Maxwell-Wagner polarization. The electrical conduction in Ni doped BST sample has been modelled by the grain boundary resistance and hopping mechanism. The results open up a potential magnetocapacitance device application.
Graphical Abstract
The spatial and temporal distribution of various trace elements in water and suspended solids in urban runoff from residential and industrial sites was studied. 240 sequential urban runoff samples ...from 39 rain/storm events were collected, processed and analyzed for 13 elements (12 metals – Al, Co, Cd, Cr, Cu, Fe, Mn, Pb, Ni, Ti, V, and Zn, and one metalloid – As). The experimental protocol used in this study was validated using standard reference material (NIST 1648, urban particulate matter) and certified rain water samples. Good agreement was obtained between the certified and measured values. Al, Fe and Zn were found to be abundant in both residential and industrial runoffs. Some of the metals demonstrated first flush phenomena. Investigation of dissolved fraction, environmentally mobile fraction and total concentration for the 13 elements revealed that trace elements in industrial runoff were highly enriched as compared to those in the residential runoff. The environmentally mobile fraction was quite significant for most of the trace elements. Statistical correlations among the metals were studied, and principal component analysis (PCA) was used for identification of the major sources of the metals/metalloid in both residential and industrial runoffs. Crustal leaching, paints from building walls, and atmospheric deposition were found to be the main sources of metals/metalloid in runoff from the residential site while emissions from petrochemical and semiconductor industries, metal corrosion and vehicular emissions were the main sources of metals/metalloid in runoff from the industrial site. These results are presented and discussed in this paper.
Both zinc oxide (ZnO) and reduced graphene oxide (rGO) are known for its attractive optical properties in their nano form. Here, ZnO-rGO nanocomposites and rGO were prepared via simple and ...reproducible hydrothermal as well as modified Hummer’s method. Microstructural identification of phase formation and dispersion of ZnO on rGO was confirmed by X-ray diffraction and transmission electron microscopy (TEM) measurements. The reduction of graphene oxide was confirmed by the appearance of D and G band peaks in Raman spectra. Optical bandgap of samples was estimated by UV–Visible diffused reflectance spectroscopy up to IR region. A systematic study of photocatalytic behavior towards the degradation of organic dyes such as methyl orange and rhodamine B under the influence of UV light source is demonstrated. Better than 85% of degradation was measured for both the dyes in the presence of ZnO-rGO composite during 2 h of UV illuminations. The enhanced photocatalytic activity of the composites is attributed to electron–hole charge transfer, which also promises its use in photovoltaics.
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