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2.
Sci Rep ; 13(1): 12643, 2023 Aug 04.
Article in English | MEDLINE | ID: mdl-37542113

ABSTRACT

The Indian summer monsoon rainfall (ISMR) exhibits significant variability, affecting the food and water security of the densely populated Indian subcontinent. The two dominant spatial modes of ISMR variability are associated with the El Niño Southern Oscillation (ENSO) and the strength of the semi-permanent monsoon trough along with related variability in monsoon depressions, respectively. Although the robust teleconnection between ENSO and ISMR has been well established for several decades, the major drivers leading to the time-varying relationship between ENSO and ISMR patterns across different regions of the country are not well understood. Our analysis shows a consistent increase from a moderate to substantially strong teleconnection strength between ENSO and ISMR from 1901 to 1940. This strengthened relationship remained stable and strong between 1941 and 1980. However, in the recent period from 1981 to 2018 the teleconnection decreased consistently again to a moderate strength. We find that the ENSO-ISMR relationship exhibits distinct regional variability with time-varying relationship over the north, central, and south India. Specifically, the teleconnection displays an increasing relationship for north India, a decreasing relationship for central India and a consistent relationship for south India. Warm SST anomalies over the eastern Pacific Ocean correspond to an overall decrease in the ISMR, while warm SST anomalies over the Indian Ocean corresponds to a decrease in rainfall over the north and increase over the south of India. The central Indian region experienced the most substantial variation in the ENSO-ISMR relationship. This variation corresponds to the variability of the monsoon trough and depressions, strongly influenced by the Pacific Decadal Oscillation and North Atlantic Oscillation, which regulate the relative dominance of the two spatial modes of ISMR. By applying the PCA-Biplot technique, our study highlights the significant impacts of various climate drivers on the two dominant spatial modes of ISMR which account for the evolving nature of the ENSO-ISMR relationship.

3.
Biomedicines ; 11(2)2023 Feb 12.
Article in English | MEDLINE | ID: mdl-36831067

ABSTRACT

In the present study, we used a simple ultrasonic approach to develop a Cerium oxide/Graphene oxide hybrid (CeO2/GO hybrid) nanocomposite system. Particle size analysis, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and X-ray Diffraction (XRD) have been used to analyze the physio-chemical characteristics of the developed nanocomposite. The synthesized hybrid system has also been examined to assess its anticancer capability against MCF-7 cell lines and normal cell lines at different sample concentrations, pH values, and incubation intervals using an antiproliferative assay test. The test results demonstrate that as sample concentration rises, the apoptotic behavior of the CeO2/GO hybrid in the MCF-7 cell line also rises. The IC50 was 62.5 µg/mL after 72 h of incubation. Cytotoxicity of cisplatin bound CeO2/GO hybrid was also tested in MCF-7 cell lines. To identify apoptosis-associated alterations of cell membranes during the process of apoptosis, a dual acridine orange/ethidium bromide (AO/EB) fluorescence staining was carried out at three specified doses (i.e., 1000 µg/mL, 250 µg/mL, and 62.5 µg/mL of CeO2/GO hybrid). The color variations from both live (green) and dead (red) cells were examined using fluorescence microscopy under in vitro conditions. The quantitative analysis was performed using flow cytometry to identify the cell cycle at which the maximum number of MCF-7 cells had been destroyed as a result of interaction with the developed CeO2/GO hybrid (FACS study). According to the results of the FACS investigation, the majority of cancer cells were inhibited at the R3 (G2/M) phase. Therefore, the CeO2/GO hybrid has successfully showed enhanced anticancer efficacy against the MCF-7 cell line at the IC50 concentration. According to the current study, the CeO2/GO platform can be used as a therapeutic platform for breast cancer. The synergetic effects of the developed CeO2/GO hybrid with the MCF-7 cell line are presented.

4.
Chem Biol Interact ; 278: 32-39, 2017 Dec 25.
Article in English | MEDLINE | ID: mdl-28987329

ABSTRACT

A newly synthesised zerumbone pendant derivative (ZPD) was studied in human cervical cancer cells (HeLa) for its anticancer properties. ZPD significantly inhibited the growth of human cervical cancer cells with a GI50 value of 6.35 ± 1.30 µM, which also induced morphological changes and apoptosis in a dose-dependent manner. Our data indicated that ZPD actively encouraged programmed cell death in HeLa cells which were confirmed by DNA fragmentation, phosphatidylserine translocation, increased activity of caspase 3, upregulation of the expression of the pro-apoptotic protein Bax, cleaved PARP, cleaved caspase 3 and downregulation of anti-apoptotic protein Bcl-2. ZPD also inhibited cell migration of HeLa cells, decreasing the production of MMP-2,-9 and downregulation of expression of MMPs and pro-angiogenic factor VEGF. Also it is nontoxic to normal rat cardiac myoblasts. Overall, ZPD is a promising candidate for inducing cytotoxicity, apoptosis and anti-migratory effects in cervical cancer cells.


Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Sesquiterpenes/pharmacology , Antineoplastic Agents/chemistry , Caspase 3/metabolism , Cell Movement/drug effects , DNA Fragmentation/drug effects , Down-Regulation/drug effects , Female , HeLa Cells , Humans , Microscopy, Fluorescence , Paclitaxel/toxicity , Phosphatidylserines/metabolism , Poly(ADP-ribose) Polymerases/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , Sesquiterpenes/chemistry , Up-Regulation/drug effects , Uterine Cervical Neoplasms/metabolism , Uterine Cervical Neoplasms/pathology , bcl-2-Associated X Protein/metabolism
5.
Ecotoxicol Environ Saf ; 134(Pt 2): 319-326, 2016 Dec.
Article in English | MEDLINE | ID: mdl-26318918

ABSTRACT

The use of natural fibers as reinforcing materials in thermoplastics and thermoset matrix composites provide optimistic environmental profits with regard to ultimate disposability and better use of raw materials. The present work is focused on the corrosion inhibition property of a polymer matrix composite produced by the use of groundnut shell (GNS) waste. Polyester (PE) was synthesized by condensation polymerization of symmetrical 1,3,4-oxadiazole and pimelic acid using sodium lauryl sulfate as surfactant. The polyester-groundnut shell composite (PEGNS) was prepared by ultrasonication method. The synthesized polyester-groundnut shell composite was characterized by FT-IR, TGA and XRD analysis. The corrosion inhibitory effect of PEGNS on mild steel in 1M H2SO4 was investigated using gravimetric method, electrochemical impedance spectroscopy, potentiodynamic polarization, atomic absorption spectroscopy and scanning electron microscopy. The results showed that PEGNS inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiency increased with increasing inhibitor concentration and decrease with increasing temperature. The composite inhibited the corrosion of mild steel through adsorption following the Langmuir adsorption isotherm. Changes in the impedance parameters Rt, Cdl, Icorr, Ecorr, ba and bc suggested the adsorption of PEGNS onto the mild steel surface, leading to the formation of protective film.


Subject(s)
Nuts/chemistry , Polyesters/chemistry , Steel/chemistry , Surface-Active Agents/chemistry , Corrosion , Dielectric Spectroscopy , Microscopy, Electron, Scanning , Oxadiazoles , Polymers/chemistry , Spectrophotometry, Atomic , Spectroscopy, Fourier Transform Infrared , Temperature
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