79 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
Generalized MICZ-Kepler Problems and Unitary Highest Weight Modules
For each integer , we demonstrate that a -dimensional
generalized MICZ-Kepler problem has an \mr{Spin}(2, 2n+2) dynamical symmetry
which extends the manifest \mr{Spin}(2n+1) symmetry. The Hilbert space of
bound states is shown to form a unitary highest weight \mr{Spin}(2,
2n+2)-module which occurs at the first reduction point in the
Enright-Howe-Wallach classification diagram for the unitary highest weight
modules. As a byproduct, we get a simple geometric realization for such a
unitary highest weight \mr{Spin}(2, 2n+2)-module.Comment: 27 pages, Refs. update
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 âillusionâ, 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
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Biotransformation of rare earth oxide nanoparticles eliciting microbiota imbalance
Background
Disruption of microbiota balance may result in severe diseases in animals and phytotoxicity in plants. While substantial concerns have been raised on engineered nanomaterial (ENM) induced hazard effects (e.g., lung inflammation), exploration of the impacts of ENMs on microbiota balance holds great implications.
Results
This study found that rare earth oxide nanoparticles (REOs) among 19 ENMs showed severe toxicity in Gram-negative (Gâ) bacteria, but negligible effects in Gram-positive (G+) bacteria. This distinct cytotoxicity was disclosed to associate with the different molecular initiating events of REOs in Gâ and G+ strains. La2O3 as a representative REOs was demonstrated to transform into LaPO4 on Gâ cell membranes and induce 8.3% dephosphorylation of phospholipids. Molecular dynamics simulations revealed the dephosphorylation induced more than 2-fold increments of phospholipid diffusion constant and an unordered configuration in membranes, eliciting the increments of membrane fluidity and permeability. Notably, the ratios of Gâ/G+ reduced from 1.56 to 1.10 in bronchoalveolar lavage fluid from the mice with La2O3 exposure. Finally, we demonstrated that both IL-6 and neutrophil cells showed strong correlations with Gâ/G+ ratios, evidenced by their correlation coefficients with 0.83 and 0.92, respectively.
Conclusions
This study deciphered the distinct toxic mechanisms of La2O3 as a representative REO in Gâ and G+ bacteria and disclosed that La2O3-induced membrane damages of Gâ cells cumulated into pulmonary microbiota imbalance exhibiting synergistic pulmonary toxicity. Overall, these findings offered new insights to understand the hazard effects induced by REOs
Multiplatform Analysis of 12 Cancer Types Reveals Molecular Classification within and across Tissues of Origin
Recent genomic analyses of pathologically-defined tumor types identify âwithin-a-tissueâ disease subtypes. However, the extent to which genomic signatures are shared across tissues is still unclear. We performed an integrative analysis using five genome-wide platforms and one proteomic platform on 3,527 specimens from 12 cancer types, revealing a unified classification into 11 major subtypes. Five subtypes were nearly identical to their tissue-of-origin counterparts, but several distinct cancer types were found to converge into common subtypes. Lung squamous, head & neck, and a subset of bladder cancers coalesced into one subtype typified by TP53 alterations, TP63 amplifications, and high expression of immune and proliferation pathway genes. Of note, bladder cancers split into three pan-cancer subtypes. The multi-platform classification, while correlated with tissue-of-origin, provides independent information for predicting clinical outcomes. All datasets are available for data-mining from a unified resource to support further biological discoveries and insights into novel therapeutic strategies
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