1,723,714 research outputs found
Differential regulation of intracellular factors mediating cell cycle, DNA repair and inflammation following exposure to silver nanoparticles in human cells
No full text10.1186/2041-9414-3-2Genome Integrity3
Inhibition of poly (ADP-Ribose) polymerase-1 in telomerase deficient mouse embryonic fibroblasts increases arsenite-induced genome instability
No full text10.1186/2041-9414-1-5Genome Integrity1
UHRF1 is a genome caretaker that facilitates the DNA damage response to γ-irradiation
No full text10.1186/2041-9414-1-7Genome Integrity1
Stable expression of promyelocytic leukaemia (PML) protein in telomerase positive MCF7 cells results in alternative lengthening of telomeres phenotype
No full text10.1186/2041-9414-3-5Genome Integrity3
Effects of BRCA2 deficiency on telomere recombination in non-ALT and ALT cells
No full textThis article has been made available through the Brunel Open Access Publishing Fund - Copyright @ 2011 Sapir et al.Background: Recent studies suggest that BRCA2 affects telomere maintenance. Interestingly, anti cancer treatments that involve BRCA2 and telomerase individually are currently being explored. In the light of the above recent studies their combinatorial targeting may be justified in the development of future treatments. In order to investigate effects of BRCA2 that can be explored for this combinatorial targeting we focused on the analysis of recombination rates at telomeres by monitoring T-SCEs (Telomere Sister Chromatid Exchanges). Results: We observed a significant increase in T-SCE frequencies in four BRCA2 defective human cell lines thus suggesting that BRCA2 suppresses recombination at telomeres. To test this hypothesis further we analyzed T-SCE frequencies in a set of Chinese hamster cell lines with or without functional BRCA2. Our results indicate that introduction of functional BRCA2 normalizes frequencies of T-SCEs thus supporting the notion that BRCA2 suppresses recombination at telomeres. Given that ALT (Alternative Lengthening of Telomeres) positive cells maintain telomeres by recombination we investigated the effect of BRCA2 depletion in these cells. Our results show that this depletion causes a dramatic reduction in T-SCE frequencies in ALT positive cells, but not in non-ALT cells. Conclusion: BRCA2 suppresses recombination at telomeres in cells that maintain them by conventional mechanisms. Furthermore, BRCA2 depletion in ALT positive cells reduces high levels of T-SCEs normally found in these cells. Our results could be potentially important for refining telomerase-based anti-cancer therapies.This work is supported in part by grants from European Commission RISC-RAD contract FI6RCT2003-508842 and British Counci
Kinetika fermentasi selulosa murni oleh Trichoderma reesei QM 9414 menjadi glukosa dan penerapannya pada jerami pad1 bebas lignin = Kinetics of Pure Cellulose Fermentation by Trichoderma Reesei QM 9414 to Glucose and the
Get PDFABSTRACT
The objectives of this research were: 1) to determine aeration rate and substrate concentration of pure cellulose to produce maximum glucose by Trichoderma reesei QM 9414 at 30 °C, and agitation at 150 rpm2) to study the kinetics of pure cellulose fermentation by Trichoderma reesei QM 9414 to glucose and its implication upon fermentation of the lignin free rice straw. The experiment was arranged in factorial randomized complete design consisted of three levels of aeration (1,00 vvm1,5 vvm2,0 vvm) and three levels of substrate concentration (0,75 %1,00 %1,25 % w/v).
The results showed that at the exponential phase that the average specific growth of Trichoderma reesei QM 9414 was 0,05374 hour-I, the maximum glucose product concentration of pure cellulose was 0.1644 gri ,and the oxygen transfer was 0,0328 mg L-1 hour-i.
According to t-test, the kinetics of pure cellulose fermentation model just the same as the lignin \u27free rice straw fermentation.
The enzymes produced by Trichoderma reesei QM 9414 in pure cellulose fermentation media followed the Michaelis-Menten model. The enzyme kinetic parameters were the maximum growth Michaelis-Menten constant
hour rate was 37x10-3 hour-1 and
was 1/2 maximum p 17,5x10.3
The volumetric oxyfen transfer (K,) using rice straw was 0,0337 mg. hour . The value of KIA, could be used for conversion from bioreactor at laboratory scale to commercial scale design.
Key Words: Kinetics, fermentation, Trichoderma reesei, cellulose, lignin, rice stra
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Kinetika Fermentasi Selulosa Murni oleh Trichoderma reesei QM 9414 Menjadi Glukosa dan Penerapannya pada Jerami Padi Bebas Lignin
No full textThe objectives of this research were: 1) to determine aeration rate and substrate concentration of pure cellulose to produce maximum glucose by Trichoderma reesei QM 9414 at 30 °C, and agitation at 150 rpm; 2) to study the kinetics of pure cellulose fermentation by Trichoderma reesei QM 9414 to glucose and its implication upon fermentation of the lignin free rice straw. The experiment was arranged in factorial randomized complete design consisted of three levels of aeration (1,00 vvm; 1,5 vvm; 2,0 vvm) and three levels of substrate concentration (0,75 %; 1,00 %; 1,25 % w/v). The results showed that at the exponential phase that the average specific growth of Trichoderma reesei QM 9414 was 0,05374 hour-I, the maximum glucose product concentration of pure cellulose was 0.1644 gri ,and the oxygen transfer was 0,0328 mg L-1 hour-i. According to t-test, the kinetics of pure cellulose fermentation model just the same as the lignin 'free rice straw fermentation. The enzymes produced by Trichoderma reesei QM 9414 in pure cellulose fermentation media followed the Michaelis-Menten model. The enzyme kinetic parameters were the maximum growth Michaelis-Menten constant hour rate was 37x10-3 hour-1 and was 1/2 maximum p 17,5x10.3. The volumetric oxyfen transfer (K,) using rice straw was 0,0337 mg. hour . The value of KIA, could be used for conversion from bioreactor at laboratory scale to commercial scale design
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