Studying of hadron production in forward direction at the LHC energy has a great interest both for understanding of the fundamental QCD processes and also in applied areas such as the description of ...ultra-high energy cosmic particle interactions. The energies of secondary hadrons in such studies almost reach the maximum energy available at the LHC of ~6 TeV, which corresponds to a Lorentz γ-factor up to 104 and above. The only effective technique able to identify particles in this range is based on the transition radiation detectors (TRD). Prototypes of such kind of detector were built and tested at the CERN SPS accelerator. Some experimental results obtained in these tests are briefly presented here and compared with Monte Carlo (MC) simulations. MC model demonstrates a good agreement with the experiment. On this basis a concept of a full-scale TRD optimized for the hadron identification in the TeV energy region is proposed. Different particle identification techniques were considered and examined. The expected detector performance to reconstruct secondary hadrons produced in forward direction at the LHC is presented.
Increased expression of epidermal growth factor receptors (EGFR) in breast cancer (BC) is often associated with trastuzumab (Herceptin)-resistant forms of the disease and represents an attractive ...target for novel therapies. Nimotuzumab is a humanized IgG(1) monoclonal antibody that is in clinical trials for treatment of EGFR-overexpressing malignancies. We show here that nimotuzumab derivatized with benzylisothiocyanate diethylenetriaminepentaacetic acid for labelling with the subcellular range Auger electron-emitter, (111)In and modified with nuclear translocation sequence (NLS) peptides ((111)In-NLS-Bn-DTPA-nimotuzumab) was bound, internalized and transported to the nucleus of EGFR-positive BC cells. Emission of Auger electrons in close proximity to the nucleus caused multiple DNA double-strand breaks which diminished the clonogenic survival (CS) of MDA-MB-468 cells that have high EGFR density (2.4 × 10(6) receptors/cell) to less than 3 %. (111)In-Bn-DTPA-nimotuzumab without NLS peptide modification was sevenfold less effective for killing MDA-MB-468 cells. (111)In-Bn-DTPA-nimotuzumab with/without NLS peptide modification were equivalently cytotoxic to MDA-MB-231 and TrR1 BC cells that have moderate EGFR density (5.4 × 10(5) or 4.2 × 10(5) receptors/cell, respectively) reducing their CS by twofold. MDA-MB-231 cells have intrinsic trastuzumab resistance due to low HER2 density, whereas TrR1 cells have acquired resistance despite HER2 overexpression. Biodistribution and microSPECT/CT imaging revealed that (111)In-NLS-Bn-DTPA-nimotuzumab exhibited more rapid elimination from the blood and lower tumour uptake than (111)In-Bn-DTPA-nimotuzumab. Tumour uptake of the radioimmunoconjugates in mice with MDA-MB-468 xenografts was high (8-16 % injected dose/g) and was blocked by administration of an excess of unlabelled nimotuzumab, demonstrating EGFR specificity. We conclude that (111)In-Bn-DTPA-nimotuzumab with/without NLS peptide modification are promising Auger electron-emitting radioimmunotherapeutic agents for EGFR-positive BC, but (111)In-Bn-DTPA-nimotuzumab may be preferred due to its higher tumour uptake in vivo.
Ways are considered for the indirect ultrasonic measuring of elastomer figures of merit (fracture strength and Mooney viscosity), using a procedure developed for minimizing the measuring error. An ...ultrasonic technique is used to study SKS-30 rubber samples. The optimum temperature and frequency conditions for measuring indicators are determined.
Cross-section measurements of top-quark pair production where the hadronically decaying top quark has transverse momentum greater than 355 GeV and the other top quark decays into ℓνb are presented ...using 139 fb–1 of data collected by the ATLAS experiment during proton-proton collisions at the LHC. The fiducial cross-section at √s = 13 TeV is measured to be σ = 1.267 ± 0.005 ± 0.053 pb, where the uncertainties reflect the limited number of data events and the systematic uncertainties, giving a total uncertainty of 4.2%. The cross-section is measured differentially as a function of variables characterizing the tt¯ system and additional radiation in the events. The results are compared with various Monte Carlo generators, including comparisons where the generators are reweighted to match a parton-level calculation at next-to-next-to-leading order. The reweighting improves the agreement between data and theory. The measured distribution of the top-quark transverse momentum is used to search for new physics in the context of the effective field theory framework. No significant deviation from the Standard Model is observed and limits are set on the Wilson coefficients of the dimension-six operators OtG and $O$ $^{(8)}_{tq}$, where the limits on the latter are the most stringent to date.
We plan to develop an advanced Transition Radiation Detector (TRD) for hadron identification in the TeV momentum range, based on the simultaneous measurement of the energies and of the emission ...angles of the Transition Radiation (TR) X-rays with respect to the radiating particles. To study the feasibility of this project, we have carried out a beam test campaign at the CERN SPS facility with 20 GeV/c electrons and muons up to 300 GeV/c. To detect the TR X-rays and the radiating particles, we used a 300 μm thick double-sided silicon strip detector, with a strip readout pitch of 50 μm. A 2 m long helium pipe was placed between the radiators and the detector, in order to ensure adequate separation between the TR X-rays and the radiating particle on the detector plane and to limit the X-ray absorption before the detector. We measured the double-differential (in energy and angle) spectra of the TR emitted by several radiators. The results are in good agreement with the predictions obtained from the TR theory.
Background. Human cytomegalovirus (HCMV) is a ubiquitous viral infection of worldwide distribution. This virus is the most significant infectious cause of congenital disease, an important opportunist ...in the immunocompromised hosts, such as allogeneic hematopoietic stem cells transplantation (allo-HSCT) recipients (Mokarski E.S.,2013). If seropositive recipient develops HCMV infection after allo-HSCT, it is usually unknown whether it is a reactivation of endogenous HCMV or a reinfection by a new exogenous HCMV strain. The impact of genetic diversity of HCMV on its pathogenesis has not been well evaluated by now. However, the emerging data indicate a possible correlation: the viral load and the course of the infection were different in AIDS patients with different HCMV genotypes (Renzette, 2015). The estimation of a possible link between viral genotype and probability of HCMV infection occurrence is relevant. Very little data on difference in HCMV genotypes within one patient before and after allo-HSCT is available.
The aim. The aim of this study was the identification of difference in HCMV UL139 gene sequences before and after the allo-HSCT.
Materials and Methods. Patients: 13 allo-HSCT recipients (5 ALL, 3 AML, 3 CML, 1 AA, 1 lymphoma of the mantle) were enrolled in the study, male/female 6/7; median age was 27 (22-49) years. Patients' blood samples were collected within 6 month before and 6 month after transplantation and tested for the HCMV DNA by PCR. Positive samples were sequenced by Sanger inside the UL139 (putative membrane gp gene) region for genotyping. Sequences within one patient before and after transplantation were compared by BLAST (Basic Local Alignment Search Tool) software.
Results and discussion. Sequencing was successfully completed only in samples of 7 patients (pts), probably due to low concentration of the viral DNA in the samples or other technical issues. The comparison of sequences showed (see table) that 3 out of 7 pts had reactivation of endogenous virus, because sequences exhibited 100% match. Another 2 out of 7 patients' sequences showed about 88% match. This indicates change in genotype to phylogenetically closest one. The rest 2 pts did not show any similarity in sequences at all which definitely points to reinfection after allo-HSCT. Data obtained are similar to a recent study by Zawilinska (Zawilinska B, 2016), which appeals that reinfection occurs slightly more often than reactivation. Data analys showed that reactivation was detected in patients with AML, reinfection in patients with ALL. Average period before reactivation occurrence was 27 days and before reinfection occurrence - 111 days. Statistical reliability cannot be obtained due to patients' number paucity. The genotyping of patients' HCMV by comparison of sequences with known genotypes of the UL139 gene from GenBank® revealed that before transplantation HCMV genotype in 3 patients had a strong resemblance to genotype 2, another 2 patients had genotype close to the genotype 5, and 1 patient had genotype 1. After transplantation genotype 2 became dominant and was identified in 6 out of 7 patients (see table).
Conclusions. The conducted study shows that HCMV infection after allo-HSCT may be the result of both reactivation of endogenous virus and reinfection by exogenous strain. Reactivation was detected in patients with AML only, reinfection - in patients with ALL only. Reactivation developed earlier than reinfection (27 days versus 111 days). The chosen method allowed us to detect several mononucleotide substitutions in sequences, what can be useful in cases when no evident change of genotype happened after allo-HSCT. There are several possible explanations of the occurrence of reinfection: possible transmission from the outer environment or reactivation of a minor genotype if 2 or more HCMV genotypes originally had taken place. Further studies are required for more reliable conclusions.
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No relevant conflicts of interest to declare.
A search for decays of pair-produced neutral long-lived particles (LLPs) is presented using 139 fb-1 of proton-proton collision data collected by the ATLAS detector at the LHC in 2015–2018 at a ...centre-of-mass energy of 13 TeV. Dedicated techniques were developed for the reconstruction of displaced jets produced by LLPs decaying hadronically in the ATLAS hadronic calorimeter. Two search regions are defined for different LLP kinematic regimes. The observed numbers of events are consistent with the expected background, and limits for several benchmark signals are determined. For a SM Higgs boson with a mass of 125 GeV, branching ratios above 10% are excluded at 95% confidence level for values of c times LLP mean proper lifetime in the range between 20 mm and 10 m depending on the model. Upper limits are also set on the cross-section times branching ratio for scalars with a mass of 60 GeV and for masses between 200 GeV and 1 TeV.
The effects of actinic light (AL) intensity on the age dependence of nonphotochemical fluorescence quenching (q
N
) and effective quantum yield in PSII (Φ
PSII
) were studied in continuously ...illuminated wheat leaves of the upper tier. Regular changes were revealed in both age dependence of q
N
at elevated AL intensities and light curves of q
N
. These changes are related to alterations in strategies of redistribution and use of absorbed light energy by the photosynthetic apparatus at different stages of wheat leaf development. Unlike Φ
PSII
, q
N
as a parameter was more sensitive to the differences in the leaf age at a certain range of light intensities. At the same time, the stability of q
N
at moderate light intensities may serve as an indication of leaf maturity.
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