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61.
From the yellow flowers of Chrysanthemum indicum, a new flavone glycoside, acacetin 7-O-β-d-galactopyranoside was isolated and its structure established from spectral evidence and synthesis. 相似文献
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63.
Atanu Sarkar 《EcoHealth》2010,7(1):114-126
Millions of people living in India are at risk by consuming arsenic contaminated groundwater. Several technological solutions
have failed to address the problem due to segmental approaches, resulting in human suffering for a period of three decades.
The article is based on an analysis of arsenic-related health problems from an ecosystem perspective through a primary survey
conducted in five arsenic affected villages in the state of West Bengal and review of existing research and policy documents.
Although modern agricultural practices and drinking water policies have resulted in arsenic contamination of groundwater,
current mitigation policy is essentially confined to biomedical approaches, which includes potable water supply and medical
care. The study also shows that existing disparity, difficulty in coping, inaccessibility to health service and potable water
supply and lack of participation in decision making have resulted in more suffering among the poor. On the other hand, spreading
of arsenic contamination in the ecosystem remains unabated. Foods grown in the affected area have emerged as additional sources
of exposure to humans. There is lack of evidence of any perceivable benefits due to sustainable agriculture, as present nature
of agriculture practice is essentially driven by crop yield only. Further research is needed to generate credible evidence
of alternative agriculture paradigms that may eventually reduce body burden of arsenic through reduced dependency on groundwater. 相似文献
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65.
A messenger ribonucleoprotein (mRNP) particle containing the mRNA coding for the myosin heavy chain (MHC mRNA) has been isolated from the postpolysomal fraction of homogenates of 14-day-old chick embryonic muscles. The mRNP sediments in sucrose gradient as 120 S and has a characteristic buoyant density of 1.415 g/cm3, which corresponds to an RNA:protein ratio of 1:3.8. The RNA isolated from the 120 S particle behaved like authentic MHC mRNA purified from chick embryonic muscles with respect to electrophoretic mobility and ability to program the synthesis of myosin heavy chain in a rabbit reticulocyte lysate system as judged by multi-step co-purification of the in vitro products with chick embryonic leg muscle myosin added as carrier. The RNA obtained from the 120 S particle was as effective as purified MHC mRNA in stimulating the synthesis of the complete myosin heavy chains in rabbit reticulocyte lysate under conditions where non-muscle mRNAs had no such effect. Analysis of the protein moieties of the 120 S particle by sodium dodecyl sulfate-polyacrylamide gel electrophoresis shows the presence of seven distinct polypeptides with apparent molecular weights of 44,000, 49,000, 53,000, 81,000, 83,000, and 98,000, whereas typical ribosomal proteins are absent. These results indicate that the 120 S particles are distinct cellular entities unrelated to ribosomes or initiation complexes. The presence of muscle-specific mRNAs as cytoplasmic mRNPs suggests that these particles may be involved in translational control during myogenesis in embryonic muscles. 相似文献
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Rakesh Sarkar Upayan Patra Mahadeb Lo Arpita Mukherjee Asim Biswas Mamta Chawla‐Sarkar 《Cellular microbiology》2020,22(3)
Surveillance for maintaining genomic pristineness, a protective safeguard of great onco‐preventive significance, has been dedicated in eukaryotic cells to a highly conserved and synchronised signalling cascade called DNA damage response (DDR). Not surprisingly, foreign genetic elements like those of viruses are often potential targets of DDR. Viruses have evolved novel ways to subvert this genome vigilance by twisting canonical DDR to a skewed, noncanonical response through selective hijacking of some DDR components while antagonising the others. Though reported for many DNA and a few RNA viruses, potential implications of DDR have not been addressed yet in case of infection with rotavirus (RV), a double‐stranded RNA virus. In the present study, we aimed at the modulation of ataxia telangiectasia mutated (ATM)‐checkpoint kinase 2 (Chk2) branch of DDR in response to RV infection in vitro. We found activation of the transducer kinase ATM and its downstream effector Chk2 in RV‐SA11‐infected cells, the activation response being maximal at 6‐hr post infection. Moreover, ATM activation was found to be dependent on induction of the upstream sensor Mre11‐Rad50‐Nbs1 (MRN) complex. Interestingly, RV‐SA11‐mediated maximal induction of ATM‐Chk2 pathway was revealed to be neither preceded by occurrence of nuclear DNA damage nor transduced to formation of damage‐induced canonical nuclear foci. Subsequent investigations affirmed sequestration of MRN components as well as ATM‐Chk2 proteins away from nucleus into cytosolic RV replication factories (viroplasms). Chemical intervention targeting ATM and Chk2 significantly inhibited fusion and maturation of viroplasms leading to attenuated viral propagation. Cumulatively, the current study describes RV‐mediated activation of a noncanonical ATM‐Chk2 branch of DDR skewed in favour of facilitated viroplasm fusion and productive viral perpetuation. 相似文献
70.
One of the most promising applications of nanomaterials is that of nanobiosensors, using biomolecules such as nucleic acids as receptors. This study aimed to synthesize nickel oxide nanoparticles (NiO NPs) by an environmentally friendly green synthesis, using the extract of the herb Coriandrum sativum (coriander). The synthesized NPs were characterized using UV–Visible spectroscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, X‐ray photon spectroscopy, field emission scanning electron microscopy coupled with energy dispersive spectroscopy, dynamic light scattering, zeta potential and transmission electron microscopy. All results confirmed the synthesis of pure, spherical, positively charged NiO NPs of around 95 nm in diameter with prominent hydroxyl groups attached to the surface. Furthermore, interaction studies of synthesized NiO NPs with calf thymus DNA (CT DNA) were performed using UV–Visible spectroscopy, UV–thermal melting, circular dichroism, and fluorescence spectroscopy. CT DNA served as a substitute for nucleic acid biosensors. All experimental studies indicated that the NiO NPs bound electrostatically with CT DNA. These studies may facilitate exploring the potential of NiO NP–nucleic acid conjugated materials to be used as nanobiosensors for various applications, especially in pharmacological, epidemiological, and environmental diagnostic applications, and in detection. 相似文献