Characterization of Human Serum Immunoglobulin G Modified with Singlet Oxygen

Reactive oxygen species, as singlet oxygen (¹O₂), is continuously being generated by aerobic organisms, and react actively with biomolecules. At excessive amounts, ¹O₂ induces oxidative stress and shows carcinogenic and toxic effects due to oxidation of lipids, proteins and nucleic acids. In our study, immunoglobulin G (IgG) was modified by ¹O₂ generated by the ultraviolet (UV) irradiation of methylene blue. The modified IgG was characterized by UV spectroscopy, carbonyl content determination, thermal denaturation and electrophoretic study. Oxidation induced by modification of IgG by ¹O₂ also analyzed by scavenging studies. It was found that ultraviolet absorption spectra of modified IgG shows marked hyperchromicity. The carbonyl content was found to be high in modified IgG as compared to native IgG which confirms its oxidation. Thermal denaturation of modified protein sample shows decrease in Tm value by 3 °C and less intensity banding pattern on polyacrylamide gel electrophoresis. The quenching effect of sodium azide provides clue for modification of IgG by methylene blue, as it is known ¹O₂ scavenger. Hence, the IgG modified with ¹O₂ may be one of the etiological pathogenic factors for rheumatoid arthritis and diabetes.     

Ultra-sensitive hybrid diamond nanothermometer

Nitrogen-vacancy (NV) centers in diamond are promising quantum sensors because of their long spin coherence time under ambient conditions. However, their spin resonances are relatively insensitive to non-magnetic parameters such as temperature. A magnetic-nanoparticle-nanodiamond hybrid thermometer, where the temperature change is converted to the magnetic field variation near the Curie temperature, were demonstrated to have enhanced temperature sensitivity () (Wang N, Liu G-Q and Leong W-H et al. Phys Rev X 2018; 8: 011042), but the sensitivity was limited by the large spectral broadening of ensemble spins in nanodiamonds. To overcome this limitation, here we show an improved design of a hybrid nanothermometer using a single NV center in a diamond nanopillar coupled with a single magnetic nanoparticle of copper-nickel alloy, and demonstrate a temperature sensitivity of . This hybrid design enables detection of 2 mK temperature changes with temporal resolution of 5 ms. The ultra-sensitive nanothermometer offers a new tool to investigate thermal processes in nanoscale systems.     

Atrazine biodegradation efficiency, metabolite detection, and trzD gene expression by enrichment bacterial cultures from agricultural soil

Atrazine is a selective herbicide used in agricultural fields to control the emergence of broadleaf and grassy weeds. The persistence of this herbicide is influenced by the metabolic action of habituated native microorganisms. This study provides information on the occurrence of atrazine mineralizing bacterial strains with faster metabolizing ability. The enrichment cultures were tested for the biodegradation of atrazine by high-performance liquid chromatography(HPLC) and mass spectrometry. Nine cultures JS01.Deg01 to JS09.Deg01 were identified as the degrader of atrazine in the enrichment culture. The three isolates JS04.Deg01, JS07.Deg01, and JS08.Deg01 were identified as efficient atrazine metabolizers. Isolates JS04.Deg01 and JS07.Deg01 produced hydroxyatrazine(HA) N-isopropylammelide and cyanuric acid by dealkylation reaction. The isolate JS08.Deg01 generated deethylatrazine(DEA), deisopropylatrazine(DIA), and cyanuric acid by N-dealkylation in the upper degradation pathway and later it incorporated cyanuric acid in their biomass by the lower degradation pathway. The optimum pH for degrading atrazine by JS08.Deg01 was 7.0 and 16S rDNA phylogenetic typing identified it as Enterobacter cloacae strain JS08.Deg01. The highest atrazine mineralization was observed in case of isolate JS08.Deg01, where an ample amount of trzD mRNA was quantified at 72 h of incubation with atrazine. Atrazine bioremediating isolate E. cloacae strain JS08.Deg01 could be the better environmental remediator of agricultural soils and the crop fields contaminated with atrazine could be the source of the efficient biodegrading microbial strains for the environmental cleanup process.     

Telecommunications Management

DISASTER RECOVERY PLANNING FOR TELECOMMUNICATIONS by Leo A. Wrobel (Boston: Artech House, 1990—price not given, ISBN 0-89006-460-1,112 pp.)

LONG DISTANCE SERVICES: A BUYER'S GUIDE by Daniel D. Briere (Boston: Artech House, 1990—price not given, ISBN 0-89006-439-3,293 pp.)

ADVANCES IN TELECOMMUNICATIONS MANAGEMENT edited by Jagdish Sheth and Garly Frazier (Greenwich, CT: JAI Press, 1990—$63.50 each, ISBN as listed below)

MANAGING THE R&D/MARKETING INTERFACE FOR PRODUCT SUCCESS: THE TELECOMMUNICATIONS FOCUS edited by Massoud Saghafi and Ashok K. Gupta (1990—ISBN 1-55938-144-2,218 pp.)

PURCHASING IN THE 1990S: THE EVOLUTION OF PROCUREMENT IN THE TELECOMMUNICATIONS INDUSTRY edited by Wesley J. Johnston (1990—ISBN 1-55938-145-0,257 pp.)     

Eigentaste: A Constant Time Collaborative Filtering Algorithm

Eigentaste is a collaborative filtering algorithm that uses universal queries to elicit real-valued user ratings on a common set of items and applies principal component analysis (PCA) to the resulting dense subset of the ratings matrix. PCA facilitates dimensionality reduction for offline clustering of users and rapid computation of recommendations. For a database of n users, standard nearest-neighbor techniques require O(n) processing time to compute recommendations, whereas Eigentaste requires O(1) (constant) time. We compare Eigentaste to alternative algorithms using data from Jester, an online joke recommending system.Jester has collected approximately 2,500,000 ratings from 57,000 users. We use the Normalized Mean Absolute Error (NMAE) measure to compare performance of different algorithms. In the Appendix we use Uniform and Normal distribution models to derive analytic estimates of NMAE when predictions are random. On the Jester dataset, Eigentaste computes recommendations two orders of magnitude faster with no loss of accuracy. Jester is online at: http://eigentaste.berkeley.edu     

Prevalence of Vitamin D Deficiency in a Pediatric Hospital of Eastern India

Vitamin D deficiency is highly prevalent in Indian children of northern, western and southern states. Serum 25 hydroxy cholecalferol (ng/ml) was analyzed in 310 children and adolescents of pediatric hospital of Kolkata, India. Serum calcium (mg/dl), phosphorous (mg/dl) and alkaline phosphatase (IU/L) data was obtained. Median 25(OH)D was 19 ng/ml. 19.2 % of population had serum 25(OH)D < 10 ng/ml (severe deficiency), 52.9 % had <20 ng/ml (deficiency), 24.5 % had 20–29 ng/ml (insufficiency) and 22.6 % had >30 ng/ml (optimum). Deficiency was highest in adolescents (86.1 %), followed by school children (61.0 %), lowest in pre-school children (41.6 %). 25(OH)D concentrations was lowest in winters (P = 0.002) and spring (P = 0.03) compared to summer. There was no correlation with calcium (P = 0.99), phosphorous (P = 0.23) and ALP (P = 0.63). There is high prevalence of vitamin D deficiency in children and adolescents of eastern India. Prevalence was lower in younger subjects. 25(OH)D did not correlate with bone mineral markers.