479 research outputs found
Examination of Signals Involved in Dexamethasone Induced Apoptosis in Nb2 Lymphoma Cells
Consistent with previous studies, we demonstrated that dexamethasone (Dex) caused cytolysis/apoptosis in log phase Nb2 lymphoma cells, while prolactin (Prl) inhibited this effect. The Nb2 model was used to investigate the mechanisms of apoptosis control with the aid of immunocytochemistry (ICC). We established with absorption the specificity of staining due to Fas, Fas Ligand, Bcl-2, and Bax antibodies (the specificity of anti-p53 could not be verified). Dex-induced cytolysis/apoptosis was detected in synchronized (G⁰/G¹) cells after 6 and 8 hours of Dex exposure. A novel, computerized technique was used to quantitate the proportion of cells immunostained for the signals of interest in Nb2 cells in log phase a G⁰/G¹ after up to 8 hours of Dex exposure. We observed Fas, Fas Ligand, Bcl-2, Bax, and p53 in high proportions (72%-86%) of log phase Nb2 cells. Neither synchrony in G⁰/G¹ nor exposure of synchronized cells to Dex for up to 8 hours altered the proportion of immunostained cells. This study has raised provocative issues regarding the resistance of Nb2 cells to Fas mediated apoptosis, the phenotype of the p53 protein in Nb2 cells, and the possible interaction of various signals that modulate apoptosis
Statistical Processing of Subjective Test Data for Sound Quality Evaluation of Automotive Horn
Product sound quality has a significant role in buying decision and customer satisfaction. An often used method to assess the sound quality of any product or equipment is a subjective listening test where the sound is heard by a panel of subjects (jury) who then rate the sound quality. Subjects use a semantic differential rating wherein they evaluate the presented sounds based on a bipolar variable. The two extremes of the rating scale are labeled with an adjective and its antonym respectively. In the present study, a subjective listening test has been conducted to assess sound quality of automotive horns. The data obtained are then analyzed using statistics to gain insights. Twenty two horn sound samples were judged by thirty participants aged 20-40 years who had normal hearing. Binaural head set (BHS) instrument was used to record horn sound samples in open ground (neglecting wind noise effect). Sounds are recorded two meter from horn in front direction and used for subjective test. For the subjective test and subsequent statistical analysis, a four step procedure has been used. In the first step, the participants were asked to rate the sound quality for each horn based on seven bipolar variables. These bipolar variables are soft/loud, calm/frightening, slow/fast, relax/tense, safe/danger, vague/distinct and pleasant/unpleasant. For each bipolar variable, a seven verbal interval scale was used ranging from one extreme to another in degree, for example extremely pleasant to extremely unpleasant
Simulation of aerosol optical properties over a tropical urban site in India using a global model and its comparison with ground measurements
Aerosols have great impacts on atmospheric environment, human health, and
earth's climate. Therefore, information on their spatial and temporal
distribution is of paramount importance. Despite numerous studies have
examined the variation and trends of BC and AOD over India, only very few
have focused on their spatial distribution or even correlating the
observations with model simulations. In the present study, a
three-dimensional aerosol transport-radiation model coupled with a general
circulation model. SPRINTARS, simulated atmospheric aerosol distributions
including BC and aerosol optical properties, i.e., aerosol optical thickness
(AOT), Ångström Exponent (AE), and single scattering albedo (SSA).
The simulated results are compared with both BC measurements by aethalometer
and aerosol optical properties measured by ground-based skyradiometer and by
satellite sensor, MODIS/Terra over Hyderabad, which is a tropical urban area
of India, for the year 2008. The simulated AOT and AE in Hyderabad are found
to be comparable to ground-based measured ones. The simulated SSA tends to
be higher than the ground-based measurements. Both these comparisons of
aerosol optical properties between the simulations with different emission
inventories and the measurements indicate that, firstly the model
uncertainties derived from aerosol emission inventory cannot explain the
gaps between the simulations and the measurements and secondly the vertical
transport of BC and the treatment of BC-containing particles can be the main
issue in the global model to solve the gap
Laser diagnostics for characterization of sprays formed by a collapsing non-equilibrium bubble
In this paper, we investigate the use of laser diagnostic tools for in-plane imaging
of bubble induced spray using a laser sheet and Mie scattering technique. A perspex plate of
thickness 10 mm with a hole of diameter 1 mm in the center is placed in the middle of a glass
tank filled with water such that the top surface of the plate coincides with the water surface.
A bubble is created just below the hole using a low-voltage spark circuit such that it expands
against the hole. This leads to the formation of two jets which impact leading to a spray and
break-up into droplets. The spray evolution is observed using a laser sheet directed in a plane
through the center of the hole. The illuminated plane is imaged using a high-speed camera
based on the Mie scattering from glass beads suspended in the liquid. Results show that Mie
scattering technique has potential in studying bubble-induced sprays with applications such as
in fuel sprays, drug-delivery etc, and also for validation of numerical codes. We present results
from our ongoing experiments in this paper
Aerosol climatology: on the discrimination of aerosol types over four AERONET sites
International audienceAerosols have a significant regional and global effect on climate, which is about equal in magnitude but opposite in sign to that of greenhouse gases. Nevertheless, the aerosol climatic effect changes strongly with space and time because of the large variability of aerosol physical and optical properties, which is due to the variety of their sources, which are natural, and anthropogenic, and their dependence on the prevailing meteorological and atmospheric conditions. Characterization of aerosol properties is of major importance for the assessment of their role for climate. In the present study, 3-year AErosol RObotic NETwork (AERONET) data from ground-based sunphotometer measurements are used to establish climatologies of aerosol optical depth (AOD) and Ångström exponent ? in several key locations of the world, characteristic of different atmospheric environments. Using daily mean values of AOD at 500 nm (AOD500) and Ångström exponent at the pair of wavelengths 440 and 870 nm (? 440?870), a discrimination of the different aerosol types occurring in each location is achieved. For this discrimination, appropriate thresholds for AOD500 and ? 440?870 are applied. The discrimination of aerosol types in each location is made on an annual and seasonal basis. It is shown that a single aerosol type in a given location can exist only under specific conditions (e.g. intense forest fires or dust outbreaks), while the presence of well-mixed aerosols is the accustomed situation. Background clean aerosol conditions (AOD500<0.06) are mostly found over remote oceanic surfaces occurring on average in ~56.7% of total cases, while this situation is quite rare over land (occurrence of 3.8?13.7%). Our analysis indicates that these percentages change significantly from season to season. The spectral dependence of AOD exhibits large differences between the examined locations, while it exhibits a strong annual cycle
Influence of continental advection on aerosol characteristics over Bay of Bengal (BoB) in winter: results from W-ICARB cruise experiment
The transport of aerosols and pollutants from continental India to the
adjoining oceanic areas is a major topic of concern and several experimental
campaigns have been conducted over the region focusing on aerosol
characteristics and their climate implications. The present study analyzes
the spectral aerosol optical depth (AOD) variations over Bay of Bengal (BoB)
during Winter-Integrated Campaign for Aerosols, gases and Radiation Budget
(W-ICARB) from 27 December 2008 to 30 January 2009 and
investigates the influence of the adjoining landmass to the marine aerosol
field. High AOD<sub>500</sub> values (>0.7) occurred over northern BoB due to
outflow of aerosols and pollutants from the densely populated Indo-Gangetic
Plains (IGP); low AOD<sub>500</sub> (0.1–0.2) was observed in central and southern
BoB, far away from the mainland. The Angstrom exponent "α" was observed
to be high (>1.2) near coastal waters, indicating relative abundance of
accumulation-mode continental aerosols. On the other hand, over southern BoB
its values dropped below ~0.7. National Center for Environmental
Prediction (NCEP) reanalysis data on winds at 850 and 700 hPa, along with
air-mass trajectories calculated using Hybrid Single Particle Lagrangian
Integrated Trajectory (HYSPLIT) model, suggested transport of continental
aerosols from central and northern India over the BoB. On the other
hand, when the ship was crossing the eastern BoB, the aerosol loading was
strongly affected by air-masses originating from Southeast Asia, causing an
increase in AOD and α. Biomass-burning episodes over the region
played an important role in the observed aerosol properties. Terra/Aqua
Moderate Resolution Imaging Spectroradiometer (MODIS) AOD<sub>550</sub> and cruise
measured AOD<sub>550</sub> showed good agreement (<I>R</I><sup>2</sup> = 0.86 and 0.77,
respectively) over BoB, exhibiting similar AOD and α spatio-temporal
variation
Extremely large anthropogenic-aerosol contribution to total aerosol load over the Bay of Bengal during winter season
Ship-borne observations of spectral aerosol optical depth (AOD) have been carried out over the entire Bay of Bengal (BoB) as part of the W-ICARB cruise campaign during the period 27 December 2008–30 January 2009. The results reveal a pronounced temporal and spatial variability in the optical characteristics of aerosols mainly due to anthropogenic emissions and their dispersion controlled by local meteorology. The highest aerosol amount, with mean AOD<sub>500</sub>>0.4, being even above 1.0 on specific days, is found close to the coastal regions in the western and northern parts of BoB. In these regions the Ångström exponent is also found to be high (~1.2–1.25) indicating transport of strong anthropogenic emissions from continental regions, while very high AOD<sub>500</sub> (0.39&plusmn;0.07) and &alpha;<sub>380–870</sub> values (1.27&plusmn;0.09) are found over the eastern BoB. Except from the large &alpha;<sub>380–870</sub> values, an indication of strong fine-mode dominance is also observed from the AOD curvature, which is negative in the vast majority of the cases, suggesting dominance of an anthropogenic-pollution aerosol type. On the other hand, clean maritime conditions are rather rare over the region, while the aerosol types are further examined through a classification scheme based on the relationship between α and <i>d</i>&alpha;. It was found that even for the same α values the fine-mode dominance is larger for higher AODs showing the strong continental influence over the marine environment of BoB. Furthermore, there is also an evidence of aerosol-size growth under more turbid conditions indicative of coagulation and/or humidification over specific BoB regions. The results obtained using OPAC model show significant fraction of soot aerosols (~6 %–8 %) over the eastern and northwestern BoB, while coarse-mode sea salt particles are found to dominate in the southern parts of BoB
Fluorophore tagged mixed ligand copper(II) complexes: synthesis, structural characterization, protein binding, DNA cleavage and anticancer activity
Two fluorophore tagged copper(II) complexes Cu(phen)(L)(ClO4)(2)] (1) and Cu(bpy)(L)(H2O)(ClO4)](ClO4) (2), (where L=2-amino-1H-benzode]isoquinoline-1,3-(2H)dione (L), phen=1,10-phenanthroline and bpy=2,2 `-bipyridine) have been synthesized and structurally characterized. Structures of the copper complexes 1 and 2 were confirmed by single-crystal X-ray structure determination. The coordination geometry around the copper center of complexes 1 and 2 is distorted octahedral. The plasmid DNA cleavage activity of the complexes has been investigated by agarose gel electrophoresis and the study reveals that both the complexes have high plasmid DNA photo-cleavage activity. The binding interaction ability of the metal complexes with bovine serum albumin (BSA) was investigated using fluorescence spectroscopy. The cytotoxicity of the complexes has been evaluated by MTT (3-4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide) assay against A549 (adenocarcinoma human alveolar basal epithelial cells) and MCF-7 (breast cancer cell line) cell lines in comparison with cis-platin. Complexes 1 and 2 have exhibited better cytotoxic activity than cis-platin against A549 and MCF-7 cell lines. The cellular uptake study and localization of the complexes within the cells have been investigated by fluorescence microscopy. The cell staining and flow cytometry experiments suggest that complexes induce an apoptotic mode of cell death
Growth performance, in vitro antioxidant properties and chemical composition of the halophyte Limonium algarvense Erben are strongly influenced by the irrigation salinity
Limonium algarvense Erben (sea lavender) is a halophyte species with potential to provide natural ingredients with in vitro antioxidant, anti-inflammatory, neuroprotective and antidiabetic properties. This study reports for the first time the 1) cultivation of sea lavender in greenhouse conditions under irrigation with freshwater (approx. 0 mM NaCl) and saline aquaculture wastewater (300 and 600 mM NaCl), and 2) the influence of the irrigation salinity on the plant performance (e.g growth, number of produced leaves and flowers), in vitro antioxidant properties [radical scavenging activity (DPPH and ABTS), ferric reducing antioxidant power (FRAP), metal chelating properties on copper (CCA) and iron (ICA)], toxicity (in vitro on three mammalian cell lines) and chemical composition (determined by LC-ESI-HRMS/MS). The freshwater-irrigated plants had better growth performance than those irrigated with saltwater. Extracts from wild plants, had the highest antioxidant activity, but those from cultivated ones kept high in vitro antioxidant properties and interesting chemical profile. The flowers' extracts of plants irrigated with 300 mM NaCl had the highest antioxidant activities against DPPH, whereas those from freshwater-irrigated plants were more active on ABTS, CCA and FRAP. Most of the extracts showed nil toxicity. The flowers' extracts displayed the highest diversity of compounds, mainly quercetin, apigenin, luteolin, naringenin and their glycoside derivatives. Moreover, their abundance varied with the irrigation salinity. These data indicate that sea lavender plants can be successfully cultivated in greenhouse conditions under fresh- and saltwater irrigation, maintaining interesting biological and chemical properties.Funding Agency
Portuguese Foundation for Science and Technology
Portuguese National Budget
CCMAR/Multi/04326/2019
GreenVet project
ALG-01-0145-FEDER-028876
XtrerneAquaCrops
FA-05-2017-028
Lisboa-01-0145-FEDER-022125-RNEM-IST
ID/QUI/00100/201
Portuguese Foundation for Science and Technology
SFRH/BD/116604/2016
CEECIND/00425/2017info:eu-repo/semantics/publishedVersio
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