•CO gas sensing response studies of the rf magnetron sputtered ZnO thin films have been performed using SPR.•The effect of deposition temperature on the structural, surface morphological, and gas ...sensing properties of ZnO thin film have been studied.•The developed sensor shows a quick response (1s) and high sensitivity (0.091°/ppm) towards CO gas.
Optical gas sensors provide an alternative over the conventional conductometric gas sensors. Carbon monoxide (CO) gas is generally regarded as one of the most dangerous air pollutants, hence, a room temperature operated CO gas sensor using ZnO sensing film deposited on Au coated prisms has been developed using an indigenously developed surface plasmon resonance (SPR) measurement setup. This system is found to be highly sensitive with very fast response towards a wide concentration range (0.5–100ppm) of CO gas at room temperature and hence pave way for commercial application of an efficient optical CO gas sensor.
As a year 9 student on a school trip to the Melbourne Magistrates' Court, sitting in the last row and half-listening to a traffic offence case, I would have been wondering where to have lunch with ...friends once the teacher let us off on break, or trying to remember if I'd put enough money on my Myki to get home. Thinking about what it must be like to face off with the law would have only fleetingly, if ever, crossed my mind. Just over three years later, if I could describe in one word how it feels to be embroiled in a two-year legal sparring match with one of Australia’s most powerful politicians, that word would be ‘small’. In my time spent walking the endless halls of the Federal Court, trailing behind my suit-clad, briefcase-wielding legal team, trying to digest hours and hours of legal jargon, I felt small.
•SO2 gas sensor prepared by integrating of MWCNTs/RGO with SnO2.•Low sensing response of 1.2 is obtained for bare SnO2 sensor at 220°C.•Sensing response ∼5 obtained for MWCNT-SnO2 sensor at ...60°C.•Enhanced sensing response of ∼22 observed for the RGO-SnO2 sensor at 60°C.
An attempt has been made in the present work to develop a hybrid nanocomposite sensor by exploiting the novel properties of Tin oxide (SnO2), MWCNTs (Carbon nanotubes) and reduced graphene oxide (RGO) for the efficient detection of SO2 gas. MWCNT-SnO2 and RGO-SnO2 hybrid nanocomposite sensors have been prepared by incorporating MWCNTs and RGO into SnO2 nanoparticle colloidal solution respectively by chemical route. Low sensing response of 1.2 is obtained for bare SnO2 sensor at 220°C towards 500ppm SO2 gas. However, enhanced sensing response of ∼22 has been observed for the RGO-SnO2 sensor compared to ∼5 obtained for MWCNT-SnO2 sensor at a lower operating temperature of 60°C towards the same concentration of SO2 gas. Modulation of space charge region at the interface of n-SnO2 and p-RGO on interaction with the target SO2 gas is responsible for the enhanced response.
To address current complex health problems, there has been an increasing demand for smart nanocarriers that could perform multiple complimentary biological tasks with high efficacy. This has provoked ...the design of tailor made nanocarriers, and the scientific community has made tremendous effort in meeting daunting challenges associated with synthetically articulating multiple functions into a single scaffold. Branched and hyper-branched macromolecular architectures have offered opportunities in enabling carriers with capabilities including location, delivery, imaging etc. Development of simple and versatile synthetic methodologies for these nanomaterials has been the key in diversifying macromolecule based medical therapy and treatment. This review highlights the advancement from conventional "only one function" to multifunctional nanomedicine. It is achieved by synthetic elaboration of multivalent platforms in miktoarm polymers and dendrimers by physical encapsulation, covalent linking and combinations thereof.
Biological Signatures of Alzheimer's Disease Sharma, Poornima; Sharma, Anjali; Fayaz, Faizana ...
Current topics in medicinal chemistry,
01/2020, Volume:
20, Issue:
9
Journal Article
Peer reviewed
Alzheimer's disease (AD) is the most prevalent and severe neurodegenerative disease affecting more than 0.024 billion people globally, more common in women as compared to men. Senile plaques and ...amyloid deposition are among the main causes of AD. Amyloid deposition is considered as a central event which induces the link between the production of β amyloid and vascular changes. Presence of numerous biomarkers such as cerebral amyloid angiopathy, microvascular changes, senile plaques, changes in white matter, granulovascular degeneration specifies the manifestation of AD while an aggregation of tau protein is considered as a primary marker of AD. Likewise, microvascular changes, activation of microglia (immune defense system of CNS), amyloid-beta aggregation, senile plaque and many more biomarkers are nearly found in all Alzheimer's patients. It was seen that 70% of Alzheimer's cases occur due to genetic factors. It has been reported in various studies that apolipoprotein E(APOE) mainly APOE4 is one of the major risk factors for the later onset of AD. Several pathological changes also occur in the white matter which include dilation of the perivascular space, loss of axons, reactive astrocytosis, oligodendrocytes and failure to drain interstitial fluid. In this review, we aim to highlight the various biological signatures associated with the AD which may further help in discovering multitargeting drug therapy.
•Crop failure temperatures (CFT) are temperatures above which plant growth stop.•CFT is estimated from 21 CMIP5 climate models during 1950–2100 in Florida.•Developed causal chains/loops using DPSIR ...for improved planning and decision making.
Crop failure temperatures (CFTs) are critical upper threshold temperatures above which plant growth and development stop. Climate variability with CFTs has an essential impact on agriculture, which leads to a decrease in plant yield to nearly zero. This study innovatively combines data analysis and analysis of published literature to develop causal chains/loops using Driver-Pressure-State-Impact-Responses (DPSIR) framework. In data analysis, CFTs trends were estimated from 21 models participating in the Coupled Model Inter-comparison Project Phase 5 (CMIP5) for the historical (1950–2005) and future scenarios (RCP 8.5, 2006–2100) at a spatial resolution of 0.125°x0.125° over Florida region. From the scenario funnel plots, it is evident that the frequency of number days above CFTs was found to be increasing at the rate of 2 days/year, and maximum mean temperature intensity was found in the range of 0.02 to 0.04 °C/year till 21st century. The causal chain and loop help to understand the complex structure and feedback mechanism for CFTs. This also helps in bridging the gap between climate and crop to address the adaptation strategies if the impacts are known. Adaptation strategies from the effects of the crops found to be promising to mitigate the effects of climate on crop and which can be used by the stakeholders and managers for their own use.
Ionic complexation of azobenzene-containing surfactants with any type of oppositely charged soft objects allows for making them photo-responsive in terms of their size, shape and surface energy. ...Investigation of the photo-isomerization kinetic and isomer composition at a photo-stationary state of the photo-sensitive surfactant conjugated with charged objects is a necessary prerequisite for understanding the structural response of photo-sensitive complexes. Here, we report on photo-isomerization kinetics of a photo-sensitive surfactant in the presence of poly(acrylic acid, sodium salt). We show that the photo-isomerization of the azobenzene-containing cationic surfactant is slower in a polymer complex compared to being purely dissolved in aqueous solution. In a photo-stationary state, the ratio between the
and
isomers is shifted to a higher
-isomer concentration for all irradiation wavelengths. This is explained by the formation of surfactant aggregates near the polyelectrolyte chains at concentrations much lower than the bulk critical micelle concentration and inhibition of the photo-isomerization kinetics due to steric hindrance within the densely packed aggregates.
Abstract
Scaling up electric vehicles (EVs) provides an avenue to mitigate both carbon emissions and air pollution from road transport. The benefits of EV adoption for climate, air quality, and ...health have been widely documented. Yet, evidence on the distribution of these impacts has not been systematically reviewed, despite its central importance to ensure a just and equitable transition. Here, we perform a systematic review of recent EV studies that have examined the spatial distribution of the emissions, air pollution, and health impacts, as an important aspect of the equity implications. Using the Context-Interventions-Mechanisms-Outcome framework with a two-step search strategy, we narrowed down to 47 papers that met our inclusion criteria for detailed review and synthesis. We identified two key factors that have been found to influence spatial distributions. First, the cross-sectoral linkages may result in unintended impacts elsewhere. For instance, the generation of electricity to charge EVs, and the production of batteries and other materials to manufacture EVs could increase the emissions and pollution in locations other than where EVs are adopted. Second, since air pollution and health are local issues, additional location-specific factors may play a role in determining the spatial distribution, such as the wind transport of pollution, and the size and vulnerability of the exposed populations. Based on our synthesis of existing evidence, we highlight two important areas for further research: (1) fine-scale pollution and health impact assessment to better characterize exposure and health disparities across regions and population groups; and (2) a systematic representation of the EV value chain that captures the linkages between the transport, power and manufacturing sectors as well as the regionally-varying activities and impacts.
Anionic (i.e., acidic) phospholipids such as phosphotidylglycerol (PG) and cardiolipin (CL), participate in several cellular functions. Here we review intriguing in vitro and in vivo evidence that ...suggest emergent roles for acidic phospholipids in regulating DnaA protein-mediated initiation of Escherichia coli chromosomal replication. In vitro acidic phospholipids in a fluid bilayer promote the conversion of inactive ADP-DnaA to replicatively proficient ATP-DnaA, yet both PG and CL also can inhibit the DNA-binding activity of DnaA protein. We discuss how cellular acidic phospholipids may positively and negatively influence the initiation activity of DnaA protein to help assure chromosomal replication occurs once, but only once, per cell-cycle. Fluorescence microscopy has revealed that PG and CL exist in domains located at the cell poles and mid-cell, and several studies link membrane curvature with sub-cellular localization of various integral and peripheral membrane proteins. E. coli DnaA itself is found at the cell membrane and forms helical structures along the longitudinal axis of the cell. We propose that there is cross-talk between acidic phospholipids in the bacterial membrane and DnaA protein as a means to help control the spatial and temporal regulation of chromosomal replication in bacteria.
Mitochondrial oxidative stress is associated with many neurodegenerative diseases, such as traumatic brain injury (TBI). Targeted delivery of antioxidants to mitochondria has failed to translate into ...clinical success due to their nonspecific cellular localization, poor transport properties across multiple biological barriers, and associated side effects. These challenges, coupled with the complex function of the mitochondria, create the need for innovative delivery strategies.
Neutral hydroxyl-terminated polyamidoamine (PAMAM) dendrimers have shown significant potential as nanocarriers in multiple brain injury models.
-acetyl cysteine (NAC) is a clinically used antioxidant and anti-inflammatory agent which has shown significant potency when delivered in a targeted manner. Here we present a mitochondrial targeting hydroxyl PAMAM dendrimer-drug construct (TPP-D-NAC) with triphenyl-phosphonium (TPP) for mitochondrial targeting and NAC for targeted delivery to mitochondria in injured glia. Co-localization and mitochondrial content of mitochondria-targeted and unmodified dendrimer were assessed in microglia and macrophages
via immunohistochemistry and fluorescence quantification. Therapeutic improvements of TPP-D-NAC over dendrimer-NAC conjugate (D-NAC) and free NAC were evaluated
in microglia under oxidative stress challenge.
neuroinflammation targeting was confirmed in a rabbit model of TBI.
TPP-conjugated dendrimer co-localized significantly more with mitochondria than unmodified dendrimer without altering overall levels of cellular internalization. This targeting capability translated to significant improvements in the attenuation of oxidative stress by TPP-D-NAC compared to D-NAC and free NAC. Upon systemic administration in a rabbit TBI model, TPP-conjugated dendrimer co-localized specifically with mitochondria in activated microglia and macrophages in the white matter of the ipsilateral/injured hemisphere, confirming its BBB penetration and glial targeting capabilities.
D-NAC has shown promising efficacy in many animal models of neurodegeneration, and this work provides evidence that modification for mitochondrial targeting can further enhance its therapeutic efficacy, particularly in diseases where oxidative stress-induced glial cell death plays a significant role in disease progression.
PDF
