The importance of DNA polymerases in biology and biotechnology, and their recognition as potential therapeutic targets, drives development of methods for deriving kinetic characteristics of ...polymerases and their propensity to perform polynucleotide synthesis over modified DNA templates. Among various polymerases, translesion synthesis (TLS) polymerases enable cells to avoid the cytotoxic stalling of replicative DNA polymerases at chemotherapy-induced DNA lesions, thereby leading to drug resistance. Identification of TLS inhibitors to overcome drug-resistance necessitates the development of appropriate high-throughput assays. Since polymerase-mediated DNA synthesis involves the release of inorganic pyrophosphate (PPi), we established a universal and fast method for monitoring the progress of DNA polymerases based on the quantification of PPi with a fluorescence-based assay that we coupled to in vitro primer extension reactions. The established assay has a nanomolar detection limit in PPi and enables the evaluation of single nucleotide incorporation and DNA synthesis progression kinetics. The results demonstrated that the developed assay is a reliable method for monitoring TLS and identifying nucleoside and nucleotide-based TLS inhibitors.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Asphalt mastics made up using bottom ash filler (BAF) from Waste-to-Energy plant of A2A Ambiente SpA were investigated, examining both hot and cold mixing processes. Filler-bitumen ratios by weight ...in proportions of 0.2 and 0.7 were examined: eight mastics were prepared, four of which were made using natural limestone filler (LF) and the remainder using BAF. A leaching test and an X-ray fluorescence (XRF) analysis were performed for each filler.
All the asphalt mastics prepared were mainly investigated in terms of their rheological features through an assessment of the shear complex modulus (G*), in addition to the storage modulus (G’), loss modulus (G’’) and phase angle (δ). Resistance to permanent deformations under multiple stress creep and recovery loading was investigated measuring non-recoverable creep compliance (Jnr) and percent recovery (%R) at stress levels of 0.1 and 3.2 kPa and temperatures of 40, 50 and 60 °C. Differential scanning calorimetry (DSC) and Thermogravimetric Analysis (TGA) were also carried out in order to ascertain whether the degradation process of the mastics occurred at higher-temperature mixing conditions or operating temperatures. Degradation temperatures were observed above 200 °C due to the presence of the bitumen.
Rheological testing showed higher G’/G’’ values for cold asphalt mastics made up with BAF for all f/b ratios than for the corresponding solutions made with LF: average increases of 75 % were observed above 10 °C, while they increased by around 99 % above 30 °C, obtaining an 11 % lower phase angle in the latter case. It was also observed that at test temperatures over 40 °C, the mastics made up of BAF showed an overall 90 % decrease of non-recoverable creep compliance compared with the corresponding LF mastics.
Leaching tests and the ecotoxicological approach also confirmed the eco-sustainability of all the mastics when subjected to a daphnia EC50 toxicity analysis and an EC50 algal growth test.
•Bottom Ash (BA) can be used as an alternative filler for making performing hot/cold asphalt mastics.•The addition of BA does not affect the degradation process of the asphalt mastic above 200 °C.•The eco-sustainability of the asphalt mastics was confirmed by the leaching test and ecotoxicological analysis.•The greater elasticity of the mastic with BA at high filler content is confirmed when produced cold.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Introduction Work is a resource of social integration for it favors both personal development in society and brings about other important benefits, but under intense tensions it may produce mental, ...somatic and social disruptions as well as stress. Stress interferes in performance, in social relationships and sleep. The balance between work daily activities and sleep is an essential condition for mental health, and as such deserves proper care chiefly when the worker is in charge of children education as it occurs with teachers. The objective of this research is to investigate the relationship between the development of symptoms of stress and the quality of teachers’ sleep. Materials and methods The population here under scrutiny was the public schools teachers of Poços de Caldas. It was aimed at searching the rates of stress and the latter’s correlation with Brazilian occupational standards. That aim was accomplished in a population of 165 teachers, through the means of ISS-LIPP, PSQI-BR and QFEP, in order to identify and understand the impact of stress in teachers’ health and the quality of their sleep. Results The findings revealed that 59% of the teachers are stressed, being the majority at the resistance phase (39%) and a large amount of them under the prevalence of psychological stress. Moreover, they disclosed that 46.7% of the teachers sleep badly, pointing out undeniable association between sleep and both physical and psychological stress. Women, as the prevailing subgroup of the studied population (88.5%), presented more physical stress than men ( p = 0,015). Conclusion The conclusion of this study also disclosed the call for further developments in the investigation of teachers’ stress as a means for the prevention of social disruptions, disturbances in teacher’s mental health as well as in quality of their lives. Acknowledgement The authors thank Clara Hisae for her kind assistance in recruiting subjects for the study.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Characterization of synthetic oligonucleotides and quantification of primer extension mediated by a human translesion synthesis polymerase η (Pol η) over drug-induced DNA lesions in the presence on ...modified nucleotide analogs is described. Extent of primer extension for each reaction was monitored by denaturing gel electrophoresis. The data was obtained to assess the performance of the fluorescence-based primer extension (PE-PiPer) assay 1 with respect to the established and conventionally used denaturing gel electrophoresis. The obtained data reflects the specific inhibition of translesion synthesis over cisplatin containing DNA with 5-OH-CTP.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
5.
Radiation damage of polycrystalline diamond exposed to 62 MeV protons Alemanno, E; Caricato, A P; Chiodini, G ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2013, Volume:
730
Journal Article
Peer reviewed
We irradiated two diamond detectors with 62 MeV energy proton beam up to an integrated fluence of about 21015 protons/cm2 at INFN-LNS in Catania (Italy). The detectors were made of two high purity ...poly-crystal diamond sensors. The electric contacts of the two diamond sensors were from different sources and made with different techniques: a proprietary DLC/Pt/Au electric contact and our own novel UV Laser technique. We collected 120 GeV and 62 MeV proton beam data, before and after irradiation, respectively, to extract the radiation damage constant of one poly-crystal diamond sensor by using single crystal diamond detector response as reference.
Full text
Available for:
IJS, IMTLJ, KILJ, KISLJ, NUK, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
(FOCUS collaboration) Preliminary FOCUS results of the Dalitz-plot analysis of Ds+{expression} and D+ to three-pion decays are presented. The K-matrix formalism is applied for the first time to charm ...decays to fully exploit the already existing knowledge coming from the light-meson spectroscopy experiments. In particular, all measured dynamics of S-wave scattering, characterized by broad/overlapping resonances and large non-resonant background, can be properly accounted for. The results are discussed, along with their possible implications on the controversial nature of the meson.
A 4.8 m
3 unsegmented liquid scintillation detector at the underground Laboratori Nazionali del Gran Sasso has shown the feasibility of multi-ton low-background detectors operating to energies as low ...as 250 keV. Detector construction and the handling of large volumes of liquid scintillator to minimize the background are described. The scintillator, 1.5 g PPO/L-pseudocumene, is held in a flexible nylon vessel shielded by 1000 t of purified water. The active detector volume is viewed by 100 photomultipliers, which measure time and charge for each event, from which energy, position and pulse shape are deduced. On-line purification of the scintillator by water extraction, vacuum distillation and nitrogen stripping removed radioactive impurities. Upper limits were established of < 10
−7 Bq/kg-scintillator for events with energies 250 keV <
E < 800 keV, and < 10
−9 Bq/kg-scintillator due to the decay products of uranium and thorium. The isotopic abundance of
14C
12C
in the scintillator was shown to be approximately 10
−18 by extending the energy window of the detector to 25–250 keV. The
14C abundance and uranium and thorium levels in the CTF are compatible with the Borexino Solar Neutrino Experiment.
Full text
Available for:
IJS, IMTLJ, KILJ, KISLJ, NUK, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
8.
The high intensity frontier Bettoni, D.; Bianco, S.; Bossi, F. ...
Physics reports,
11/2006, Volume:
434, Issue:
3
Journal Article
Peer reviewed
Open access
In these last years, there is an unprecedented world-wide consensus on the next steps to be taken in the construction of major “energy frontier” accelerator facilities. The main threads for the ...future of world particle physics seem clear: the first priority is the completion and commissioning of the large hadron collider (LHC), the next priority is the construction of the TeV-energy LC, with a significant period of overlap with LHC running.
If the “energy frontier” for the future activities in particle physics seems to be well defined, it is becoming more and more relevant and urgent to underline the importance of other facilities for particle physics. This Report focuses the importance of a diversified experimental program in flavour physics during the LHC era. In particular this Report presents the great opportunities, offered by flavour physics, on a number of fronts within the quark flavour sector, K and charm physics, as well as within neutral and charged-lepton sector, neutrino physics and physics of lepton flavour violation. Finally it is briefly illustrated how future high intensity facilities may also offer an opportunity to perform frontier experiment in nuclear physics.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Altered protein function due to mutagenesis plays an important role in disease development. This is perhaps most evident in tumorigenesis and the associated loss or gain of function of ...tumor-suppressor genes and oncogenes. The extent to which lesion-induced transcriptional mutagenesis (TM) influences protein function and its contribution to the development of disease is not well understood. In this study, the impact of O⁶-methylguanine on the transcription fidelity of p53 and the subsequent effects on the protein’s function as a regulator of cell death and cell-cycle arrest were examined in human cells. Levels of TM were determined by RNA-sequencing. In cells with active DNA repair, misincorporation of uridine opposite the lesion occurred in 0.14% of the transcripts and increased to 14.7% when repair by alkylguanine–DNA alkyltransferase was compromised. Expression of the dominant-negative p53 R248W mutant due to TM significantly reduced the transactivation of several established p53 target genes that mediate the tumor-suppressor function, including CDKN1A (p21) and BBC3 (PUMA). This resulted in deregulated signaling through the retinoblastoma protein and loss of G1/S cell-cycle checkpoint function. In addition, we observed impaired activation of apoptosis coupled to the reduction of the tumor-suppressor functions of p53. Taking these findings together, this work provides evidence that TM can induce phenotypic changes in mammalian cells that have important implications for the role of TM in tumorigenesis.
Full text
Available for:
BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
PDF
