583 research outputs found
Biological synthesis and characterization of lead sulphide nanoparticles using bacterial isolates from heavy metal rich sites
ABSTRACT Lead is highly poisonous heavy metal (regardless if inhaled or swallowed), affecting almost every organ and system in the body. The main target for lead toxicity is the nervous system. Lead poisoning typically results from ingestion of food or water contaminated with lead; but may also occur after accidental ingestion of contaminated soil, dust, or lead-based paint. Bioremediation of lead by bacteria could be an effective measure to remove lead. This study involves the synthesis of lead sulphide nanoparticle using lead chloride and calcium sulphate salts utilizing bacterial strains isolated from the industrial sites of Allahabad and Kanpur. For synthesis, bacterial cell mass was centrifuged to separate supernatant from pellet. Both supernatant and cell pellet were challenged with lead chloride and calcium sulphate salts and lead sulphide nanoparticles were effectively synthesized. These extracellularly synthesized nanoparticles exhibited an absorbance maximum at 330 nm and were characterized using UV Visible spectrophotometer and Transmission Electron Microscope. The use of these strains seems to be promising and advantageous as it is serving dual purposes of (i) bioremediation and (ii) nanoparticle synthesis. These biologically synthesized nanoparticles could be used in various applications
Low-Energy Nuclear Astrophysics - the Fascinating Region of A=7
We discuss results and future plans for low-energy reactions that play an
important role in current nuclear astrophysics research and that happen to
concentrate around the region of A=7. The 7Be(p,gamma)8B and the
3He(4He,gamma)7Be reactions are crucial for understanding the solar-neutrino
oscillations phenomenon and the latter one plays a central role in the issue of
cosmic 7Li abundance and Big-Bang Nucleosynthesis. We also present results
regarding the host dependence of the half life of the electron-capture 7Be
radio-nuclide.Comment: 8 pages, 6 figures. Proceedings of the Erice School on Nuclear
Physics, 2006. To appear in: "Prog. Part. Nucl. Phys.
Evaluation of Ferritin and Nitric Oxide Levels in Breast Cancer
Breast carcinoma is one of the commonest malignancies in females. It is curable, if detected, at an early stage. Levels of serum ferritin and nitric oxide are found raised in various cancers including breast carcinoma. These parameters are sufficiently interlinked to be used as markers for breast cancer. In this study, the levels of ferritin and nitric oxide were estimated in 30 patients of early stage (stage I and II) and 30 patients of advanced breast cancer (stge III and IV). These levels were compared with 30 healthy females as controls. Serum ferritin and nitric oxide were found to be raised (p0.001) in all breast cancer patients as compared to controls. The rise in their levels was significantly more in advanced stage as compared to early stage carcinoma (p0.001). Treatment had a curative effect on these parameters also as shown by a decrease in their levels in both the groups. Thus, estimation of ferritin and nitric oxide may aid in diagnosis, assessment of severity and monitoring of breast cancer patients though results will be highly reliable in conjunction with other tumor markers
A New Precision Measurement of the 3He(4He,gamma)7Be Cross section
The 3He(4He,gamma)7Be reaction plays an important role in determining the
high energy solar neutrino flux and in understanding the abundances of
primordial 7Li. The present paper reports a new precision measurement of the
cross sections of this direct capture reaction, determined by measuring the
ensuing 7Be activity in the region of Ec.m.=400 keV to 950 keV. Various recent
theoretical fits to our data result in a consistent extrapolated value of
S34(0)=0.53(2)(1).Comment: 10 pages 3 figure
Solar Hydrogen Burning and Neutrinos
We summarize the current status of laboratory measurements of nuclear cross
sections of the pp chain and CN cycle. We discuss the connections between such
measurements, predictions of solar neutrino fluxes, and the conclusion that
solar neutrinos oscillate before reaching earth.Comment: 34 pages, 6 figure
Ultrasound-assisted extraction of polyphenols from potato peels: profiling and kinetic modelling
peer-reviewedUltrasoundâassisted extraction (UAE) at 33 and 42 kHz has been investigated in the extraction of polyphenols from peels of two potato varieties, creamâskinned Lady Claire (LC) and pinkâskinned Lady Rosetta (LR), commonly used in snack food production. Extraction efficacy between the UAEâuntreated (control) and the UAEâtreated extracts was assessed on the total phenolic content and antioxidant capacities (DPPH and FRAP). Application of UAE showed significantly higher recovery of phenolic compounds compared to solidâliquid extraction process alone. Lower ultrasonic frequency (33 kHz) was more effective in recovering polyphenols compared to 42 kHz ultrasonic treatment. The liquid chromatographyâtandem mass spectrometry revealed that chlorogenic acid and caffeic acid were the most prevalent phenolics in LR peels, whereas caffeic acid was dominant in LC peels. Peleg's equation showed a good correlation (R2 > 0.92) between the experimental values and the predicted values on the kinetics of UAE of phenolic compounds.The authors acknowledge financial support from the âNovTechIngâ project funded under the Food Institutional Research Measure (Project No. FIRM/11/F/050) by the Irish Department of Agriculture, Food and Marine
The (2j-1) rule with other interactions
We recently formulated a rule for isomeric states for a system of 4 nucleons
with isospin T=1, namely that if the nucleons are in a single j shell then
states with angular momenta J=2 and J=(2j-1) are either isomeric or ground
states [ze12]. To show that this is a robust result, we here consider a new
interaction from the literature that was used to discuss even-even and odd-even
nuclei. We here apply it to an odd-odd nucleus.Comment: arXiv admin note: substantial text overlap with arXiv:1107.4068,
arXiv:1112.480
Cross section measurements of the 3He(alpha, gamma) 7Be reaction using DRAGON at TRIUMF.
4 pags., 2 figs. -- Nuclear Physics in Astrophysics V 3â8 April 2011, Eilat, IsraelWe present our initial efforts with the DRAGON separator at TRIUMF facility towards obtaining the energy dependence of the astrophysical S-factor for 3He(Âż, Âż)7Be reaction in the energy range of Ecm = 2 to 3 MeV that was recommended by the recent evaluations. A comparison between the existing data and our new complementary Madrid data, together with the recent theoretical calculations, is also given in the context of our ongoing work.This work has been supported by the UK STFC
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