pollution sources into the water, the necessity of qualitative studies of water resources is one of the most important new challenges for mankind in almost every parts of the world. dissolved oxygen (do) and biochemical oxygen demand (bod) are among parameters of water quality indexes which are considered as water pollution indexes. in the present research, do and bod of dez river basin water (...

the idea of systems analysis and mathematical modeling for formulating and resolving river pollution issues is of relatively recent vintage and has been applied widely in the last 3 decades. the present study illustrates the utility of beck-modified khanna–bhutiani model (bmkb) to determine the pollution load due to the presence of organic matter in river ganga from its course from devprayag to...

A single-stranded shuttle vector has been developed for the purpose of investigating translesional events in mammalian cells. The vector is designed to permit site-specific introduction of defined DNA lesions between a gene for neomycin resistance and its promoter. Efficiencies of translesional synthesis in simian kidney cells (COS) and Escherichia coli are established by determining the number...

8-Hydroxyguanine (8-OH-G) was discovered in 1983 in our laboratory at the National Cancer Center Research Institute, Tokyo. Since it could be formed in DNA not only in vitro but also in vivo by oxygen radical forming agents, we immediately hypothesized the importance of this discovery in connection with its biological consequence. Further intensive efforts by us from 1983 to 1990 confirmed that...

An enzyme from Pseudomonas aeruginosa, Pa0142 (gi|9945972), that is able to catalyze the deamination of 8-oxoguanine (8-oxoG) to uric acid has been identified for the first time. 8-Oxoguanine is formed by the oxidation of guanine residues within DNA by reactive oxygen species, and this lesion results in G:C to T:A transversions. The value of k(cat)/K(m) for the deamination of 8-oxoG by Pa0142 a...

Oxidative stress represents a deregulation of the homeostasis between the reactive oxygen species and the mechanisms of detoxification and repair. By analyzing the level of oxidatively damaged DNA bases and nucleosides in urine we can assess the extent of DNA repair within the whole body. High levels of markers of oxidative DNA damage excreted in the urine indicate elevated levels of oxidative ...

The build up of reactive oxygen species (ROS) is known to contribute to a reduction in the lifespan of a cell and to their degeneration in diseases such as Alzheimer's and tissue ischaemia. It is therefore important to elucidate pathways that regulate cellular oxidative stress. We have previously shown that actin dynamics can affect the oxidative-stress burden on a yeast cell and thereby its po...

Human embryonic stem (hES) cells have enormous potential for clinical applications. However, one major challenge is to achieve high cell recovery rate after cryopreservation. Understanding how the conventional cryopreservation protocol fails to protect the cells is a prerequisite for developing efficient and successful cryopreservation methods for hES cell lines and banks. We investigated how t...

Vanadium dioxide is widely known for its metal-insulator transition (MIT), in which drastic changes resistivity and IR-transparency occur. This makes VO 2 thin films promising materials high-frequency optoelectronic devices. To get the most MIT sharpness, should not contain impurities of hyper-oxygen or hypo-oxygen phases arising during synthesis. ascertain conditions single-phase existence, eq...

Oligodeoxyribonucleotides containing 8-hydroxyguanine and 2-hydroxyadenine, purine lesions produced in cells by reactive oxygen species, were synthesized and inserted into vector DNAs to introduce each lesion at a predetermined site. The manipulated DNAs were transfected into living cells, and the mutants induced by each DNA lesion were collected and analyzed. In addition, the mutations induced...