65 research outputs found
Bottom Quark Cross Sections at Collider and Fixed-Target Energies at the SSC and LHC
Calculations of inclusive cross sections for the production of bottom quarks
in proton-proton collisions are presented as a function of energy, transverse
momentum, and Feynman for values of from GeV to
TeV. In addition, we provide simple parametrizations of our theoretical
results that should facilitate estimates of rates, acceptances, and
efficiencies of proposed new detectors.Comment: 6 pages plus 11 topdraw figures appended as ps-files(uuencoded),
Latex, ANL-HEP-CP-93-63 & CERN-TH.6987/9
Transverse Momentum Distributions for Heavy Quark Pairs
We study the transverse momentum distribution for a of heavy quarks
produced in hadron-hadron interactions. Predictions for the large transverse
momentum region are based on exact order QCD perturbation theory.
For the small transverse momentum region, we use techniques for all orders
resummation of leading logarithmic contributions associated with initial state
soft gluon radiation. The combination provides the transverse momentum
distribution of heavy quark pairs for all transverse momenta. Explicit results
are presented for pair production at the Fermilab Tevatron collider
and for pair production at fixed target energies.Comment: LaTeX (27 pages text, 8 figures not included, but available on
request
Spatial and temporal clonal evolution of intrahepatic cholangiocarcinoma
Background & Aims:
Intrahepatic cholangiocarcinoma (ICC) is the second-most lethal primary liver cancer. Little is known about intratumoral heterogeneity (ITH) and its impact on ICC progression. We aim to investigate its ITH in hope of helping develop new therapeutic strategies.
Methods:
We obtained 69 spatially distinct regions from 6 operable ICCs. Patient-derived primary cancer cells (PDPCs) were established for each region, followed by whole-exome sequencing(WES) and multi-level validation.
Results:
We observed widespread ITH for both somatic mutations and clonal architecture, shaped by multiple mechanisms, like clonal “illusion”, parallel evolution and chromosome instability. A median of 60.3% mutations were heterogeneous mutations, among which 85% of the driver mutations located on the branches of tumor phylogenetic trees. Many truncal and clonal driver mutations occurred in tumor-suppressor genes, such as TP53, SMARCB1 and PBRM1 that involved in DNA repair and chromatin-remodeling. Genome doubling occurred in most cases (5/6) after the accumulation of truncal mutations and was shared by all intratumoral subregions. In all cases, ongoing chromosomal instability is evident throughout the evolutionary trajectory of ICC. The recurrence of ICC1239 provided evidence to support the polyclonal metastatic seeding in ICC. The change of mutation landscape and internal diversity among subclones during metastasis, such as the loss of chemoresistance mediator, may be used for new treatment strategy. Targeted therapy against truncal alterations, such as IDH1, JAK1, and KRAS mutations and EGFR amplification, could be developed in 5/6 patients.
Conclusions:
Integrated investigations of spatial ITH and clonal evolution may provide an important molecular foundation for enhanced understanding of tumorigenesis and progression in ICC.
Lay summary:
We applied multiregional whole exome sequencing to investigate the evolution trajectory of ICC. The results revealed that many fuels, such as parallel evolution and chromosome instability, may participate and promote the branch diversity of ICC. Interestingly, in one patient with primary and recurrent metastatic tumors, we found some clues of polyclonal metastatic seeding, indicating that symbiotic communities of multiple clones existed and were maintained during metastasis. More realistically, some truncal alterations, such as IDH1, JAK1, and KRAS mutations and EGFR amplification, can be promising treatment targets for ICC patients
Preliminary Study of a G-Band Extended Interaction Oscillator Operating in the TM<sub>31</sub>-3Ď€ Mode Driven by Pseudospark-Sourced Multiple Electron Beams
This paper presents the first design that combines pseudospark-sourced (PS) electron beams with a multiple-beam extended interaction oscillator (EIO). The PS electron beam is an excellent choice for driving EIOs because it has high current density and does not require a focusing magnetic field. The EIO with coaxial structure adopts the method of multiple electron beams, which plays a crucial role in improving the average output power. At the same frequency, the EIO operating in the high-order TM31-3π mode has a larger cavity size than the EIO operating in the traditional TM01-2π mode. The high-order TM31-3π mode solves the problem of the EIO’s manufacture at high frequency. In order to verify the above points, a G-band PS multiple-beam EIO operating in TM31-3π mode has been designed. The beam–wave interaction particle-in-cell simulation results show that the EIO’s peak output power is 39.2 kW at 217 GHz, and that its efficiency is around 6.1%. The EIO with six pencil beams operates at a voltage of 43 kV. The total current of the six electron beams is 15 A (equally distributed among the six beams), and the corresponding current density is about 5000 A/cm2. Considering the ohmic loss and the effect of skin depth, the conductivity used in these simulations is 2 × 107 S/m. The design is an excellent way to improve the output power of EIO operating at high frequency
Analysis of Dual-Frequency Radiation From a -Band Extended Interaction Oscillator With Double Sheet Beam
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