The CALorimetric Electron Telescope CALET is a space instrument designed to carry out precision measurements of high energy cosmic-rays on the JEM-EF external platform on the International Space ...Station, where it has been collecting science data continuously since mid October 2015. In addition to its primary goal of identifying nearby sources of high-energy electrons and possible signatures of dark matter in the electron spectrum, CALET is carrying out extensive measurements of the energy spectra, relative abundances and secondary-to-primary ratios of elements from proton to iron, and even above (up to Z = 40), studying the details of galactic particle propagation and acceleration. An overview of CALET based on the data taken during the first three years of observations is presented, including a direct measurement of the electron+positron energy spectrum from 11 GeV to 4.8 TeV. The proton spectrum has been measured from 50 GeV to 10 TeV covering, for the first time with a single space-borne instrument, the whole energy interval previously investigated in separate sub-ranges by magnetic spectrometers and calorimetric instruments. Preliminary spectra of cosmic-ray nuclei are also presented, together with gamma-ray observations and searches for an e.m. counterpart of LIGO/Virgo GW events.
The aim of this study was to determine the frequency of p16 and hMLH1 genes simultaneous methylation in colorectal cancer patients with Microsatellite Instability (MSI) tumors. We also wanted to ...analyze the relationship with other clinical features, with BRAF gene V600E mutation and with prognosis. Samples from fifty one patients with MSI positive sporadic colorectal cancer were included. DNA was extracted from tumor samples. Promoter methylation was analyzed using bisulfite modification and was detected by quantitative methylation-specific PCR. BRAF gene was amplified using specific primers and mutations were detected by real time PCR. Simultaneous methylation was transformed in a new variable called CMETH2. Frequency of CMETH2 was analyzed and compared with other clinicopathological variables. 33.3 % of patients were positive for CMETH2 and 25 % had BRAF V600E mutation. CMETH2 was related with proximal location, with poorly differentiated tumors and with BRAF V600E mutation. CMETH2 only showed influence in the overall survival (OS) in patients with distal tumors. However, with regard to the disease free survival (DFS) measure, CMETH2 was independent prognostic factor. We were able to discriminate tumors with high methylation features using a transformation analysis of variables into a new computed one (CMETH2). CMETH2 has demonstrated to be a useful prognostic factor in MSI tumors. The prognostic value of CMETH2 in DFS was independent of other clinicopathological variables. The use of CMETH2 could help in the election of the best therapeutic alternative for CCR patients with MSI tumors.
The aim of the present study was to determine the relation of EPH tyrosine kinase receptor B2 (EPHB2) A9 region mutation and microsatellite instability (MSI); and to analyze their influence in ...prognosis of patients with sporadic colorectal cancer (CRC).
A total of 481 patients with CRC were examined. MSI (NCI criteria) and EPHB2 were analyzed using PCR and fragment analysis software.
EPHB2 mutation was detected in 3.1% of patients. Mutation of EPHB2 was associated with location and with MSI status. We considered low instability (L-MSI) when only one marker showed instability, high instability (H-MSI) when two or more markers were positive and microsatelllite stable (MSS) when no instability was detected. The stratified analysis of overall survival (OS) and disease-free survival (DFS) in MSI according to EPHB2 status revealed no statistically significant differences. However, the risk of recurrence of H-MSI tumors with EPHB2 mutation carriers was 3.6-times higher than in non-mutation carriers.
The frequency of EPHB2 mutation is higher in patients with H-MSI than MSS tumors. Promising results were found regarding the prognostic influence of EPHB2 in H-MSI.
The CALET (CALorimetric Electron Telescope) space experiment, which is currently conducting direct cosmic-ray observations onboard the International Space Station (ISS), is an all-calorimetric ...instrument optimized for cosmic-ray electron measurements with capability to measure hadrons and gamma-rays. Since the start of observation in October 2015, smooth and continuous operations have taken place. In this paper, we will give a brief summary of the CALET observations ranging from charged cosmic rays, gamma-rays, to space weather, while focusing on the energy spectra of electrons and protons.
The technological development of quantum dots has ushered in a new era in fluorescence bioimaging, which was propelled with the advent of novel multiphoton fluorescence microscopes. Here, the ...potential use of CdSe quantum dots has been evaluated as fluorescent nanothermometers for two-photon fluorescence microscopy. In addition to the enhancement in spatial resolution inherent to any multiphoton excitation processes, two-photon (near-infrared) excitation leads to a temperature sensitivity of the emission intensity much higher than that achieved under one-photon (visible) excitation. The peak emission wavelength is also temperature sensitive, providing an additional approach for thermal imaging, which is particularly interesting for systems where nanoparticles are not homogeneously dispersed. On the basis of these superior thermal sensitivity properties of the two-photon excited fluorescence, we have demonstrated the ability of CdSe quantum dots to image a temperature gradient artificially created in a biocompatible fluid (phosphate-buffered saline) and also their ability to measure an intracellular temperature increase externally induced in a single living cell.
Abstract Pure titanium and various alloys, such as Ti-6Al-4V, are widely used as biomaterials. In this application, surface finish conditions, topography, and surface reactivity determine excellent ...cellular adhesion and osseointegration characteristics. The study evaluated the influence of four surface finishing treatments (sanding #120, 600, 1200, and polished with 3 µm alumina paste) and three shapes (concave, convex, and flat) on the corrosion resistance of Ti-6Al-4V at 37 °C in simulated body fluid (SBF) through potentiodynamic polarization and electrochemical impedance spectroscopy. The SBF's ionic composition allowed the formation of a stable passive layer with a low presence of pores on the surface. In addition, the combination of polished surface and convex shape showed the best electrochemical passive behavior.
Background and aims
Gene
p53
alteration is a genetic event described in the progression from adenoma to colorectal carcinoma. Most of the
p53
mutations occur in exons 5 to 8 in highly preserved ...regions and in the three main structural domains of the p53 protein. It is possible that mutations affecting different structural regions may present different effects on the p53 protein function and, due to this, they may have different prognostic meaning.
Materials and methods
The study population consisted of 353 patients diagnosed with sporadic colorectal cancer. Mutations in 5–8 exons of
p53
gene were detected by means of single strand conformation polymorphism (SSCP). All samples that showed different migration bands in SSCP were confirmed by sequencing.
Results
A total of 69 patients (19.7%) showed alterations of the gene
p53
. It was observed that mutation in codon 175 in exon 5 was related to tumors located in the colon (
p
= 0.01) and the mutation in the codon 288 in exon 8 was related to rectal tumors (
p
= 0.02).
In the study of overall survival, mutation in codon 175 of exon 5 conferred a better prognosis and alterations of exon 8 were related to a worse prognosis in different population subgroups: in men, in patients younger than 71 years old, in the tumors located in the proximal colon, the ones moderately differentiated, and those that are mucinous.
Conclusion
According to this study, mutations in different exons of
p53
are related to different phenotypes in colorectal cancer. These phenotypes could mean differences in the clinical evolution of the patients.
We present the observation of a charge-sign dependent solar modulation of galactic cosmic rays (GCRs) with the Calorimetric Electron Telescope onboard the International Space Station over 6 yr, ...corresponding to the positive polarity of the solar magnetic field. The observed variation of proton count rate is consistent with the neutron monitor count rate, validating our methods for determining the proton count rate. It is observed by the Calorimetric Electron Telescope that both GCR electron and proton count rates at the same average rigidity vary in anticorrelation with the tilt angle of the heliospheric current sheet, while the amplitude of the variation is significantly larger in the electron count rate than in the proton count rate. We show that this observed charge-sign dependence is reproduced by a numerical “drift model” of the GCR transport in the heliosphere. This is a clear signature of the drift effect on the long-term solar modulation observed with a single detector.
The CALorimetric Electron Telescope (CALET) is a space experiment, currently under development by Japan in collaboration with Italy and the United States, which will measure the flux of cosmic-ray ...electrons (and positrons) up to 20 TeV energy, of gamma rays up to 10 TeV, of nuclei with Z from 1 to 40 up to 1 PeV energy, and will detect gamma-ray bursts in the 7 keV to 20 MeV energy range during a 5 year mission. These measurements are essential to investigate possible nearby astrophysical sources of high energy electrons, study the details of galactic particle propagation and search for dark matter signatures. The main detector of CALET, the Calorimeter, consists of a module to identify the particle charge, followed by a thin imaging calorimeter (3 radiation lengths) with tungsten plates interleaving scintillating fibre planes, and a thick energy measuring calorimeter (27 radiation lengths) composed of lead tungstate logs. The Calorimeter has the depth, imaging capabilities and energy resolution necessary for excellent separation between hadrons, electrons and gamma rays. The instrument is currently being prepared for launch (expected in 2015) to the International Space Station ISS, for installation on the Japanese Experiment Module - Exposure Facility (JEM-EF).
The CALorimetric Electron Telescope (CALET)on the International Space Station consists of a high-energy cosmic-ray CALorimeter (CAL)and a lower-energy CALET Gamma-ray Burst Monitor (CGBM). CAL is ...sensitive to electrons up to 20 TeV, cosmic-ray nuclei from Z=1 throughZ∼40, and gamma rays over the range1 GeV–10 TeV. CGBM observes gamma rays from 7 keV to 20 MeV. The combined CAL-CGBM instrument has conducted a search for gamma-ray bursts (GRBs)since 2015 October. We report here on the results of a search for X-ray/gamma-ray counterparts to gravitational-wave events reported during the LIGO/Virgo observing run O3. No events have been detected that pass all acceptance criteria. We describe the components, performance, and triggering algorithms of the CGBM—the two Hard X-ray Monitors consisting of LaBr3(Ce)scintillators sensitive to 7 keV–1 MeV gamma rays and a Soft Gamma-ray Monitor BGO scintillator sensitive to 40 keV–20 MeV—and the high-energy CAL consisting of a charge detection module, imaging calorimeter, and the fully active total absorption calorimeter. The analysis procedure is described and upper limits to the time-averaged fluxes are presented.
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