826 research outputs found
Directed and elliptic flow in heavy ion collisions from MeV/nucleon to GeV/nucleon
Recent data from the NA49 experiment on directed and elliptic flow for Pb+Pb
reactions at CERN-SPS are compared to calculations with a hadron-string
transport model, the Ultra-relativistic Quantum Molecular Dynamics (UrQMD)
model.
The rapidity and transverse momentum dependence of the directed and elliptic
flow, i.e. and , are investigated. The flow results are compared to
data at three different centrality bins. Generally, a reasonable agreement
between the data and the calculations is found. Furthermore, the energy
excitation functions of and from MeV to GeV are explored within the UrQMD framework and discussed in the
context of the available data. It is found that, in the energy regime below
GeV, the inclusion of nuclear potentials is necessary to
describe the data. Above GeV beam energy, the UrQMD model starts to
underestimate the elliptic flow. Around the same energy the slope of the
rapidity spectra of the proton directed flow develops negative values. This
effect is known as the third flow component ("antiflow") and cannot be
reproduced by the transport model. These differences can possibly be explained
by assuming a phase transition from hadron gas to quark gluon plasma at about
GeV.Comment: 19 pages, minor changes and modified title as published in PR
Indian monsoon variability on millennial-orbital timescales
The Indian summer monsoon (ISM) monsoon is critical to billions of people living in the region. Yet, significant debates remain on primary ISM drivers on millennial-orbital timescales. Here, we use speleothem oxygen isotope (δ18O) data from Bittoo cave, Northern India to reconstruct ISM variability over the past 280,000 years. We find strong coherence between North Indian and Chinese speleothem δ18O records from the East Asian monsoon domain, suggesting that both Asian monsoon subsystems exhibit a coupled response to changes in Northern Hemisphere summer insolation (NHSI) without significant temporal lags, supporting the view that the tropical-subtropical monsoon variability is driven directly by precession-induced changes in NHSI. Comparisons of the North Indian record with both Antarctic ice core and sea-surface temperature records from the southern Indian Ocean over the last glacial period do not suggest a dominant role of Southern Hemisphere climate processes in regulating the ISM variability on millennial-orbital timescales
Dynamic behaviour of prestressed concrete beams considering moving loads
U ovom se radu ispituje pravilo dinamičkog odziva prednapetih betonskih greda s metalnim i plastičnim valovitim cijevima različitih vrijednosti kompaktnosti injekcijske smjese kanala na pokretna konstantna koncentrirana opterećenja i pokretna jednostavna harmonijska opterećenja. Prednapete betonske grede s metalnim i plastičnim valovitim cijevima analizirane su metodom konačnih elemenata u slučajevima bez pukotina. Rezultati pokazuju da kompaktnost injekcijske smjese kanala i materijal za oblikovanje utječu na karakteristike prirodnih vibracija prednapetih betonskih greda. Pod istom kompaktnošću injekcijske smjese kanala, prednapete betonske grede s metalnim valovitim cijevima pokazuju veće frekvencije u usporedbi s onima koja imaju plastiče valovite cijevi. Dinamički progib prednapetih betonskih greda u sredini raspona smanjuje se s povećanjem kompaktnosti injekcijske smjese kanala, što je neovisno o materijalu za oblikovanje. Razlike u brzini i ubrzanju srednjeg raspona uzrokovane pokretnim opterećenjem između prednapetih betonskih greda metalnih i plastičnih valovitih cijevi su male. To pokazuje da materijal koji stvara pore ima mali učinak na brzinu čvora u sredini raspona i reakciju ubrzanja prednapetih betonskih greda.with different duct grouting compactness values under moving constant concentrated loads and moving simple harmonic loads is studied. Prestressed concrete beams with metal and plastic corrugated pipes are analysed using the finite element method for the case of non-cracking. The results indicate that duct grouting compactness and forming material affect the natural vibration characteristics of prestressed concrete beams. Under identical duct grouting compactness, prestressed concrete beams with metal corrugated pipes exhibit higher frequencies compared with those with plastic corrugated pipes. The mid-span dynamic deflection of the prestressed concrete beams decreases with an increase in duct grouting compactness, which is independent of the forming material. The differences in the midspan speed and acceleration caused by the moving loads between the corrugated duct prestressed concrete beams made of metal and those made of plastic are small; this indicates that the pore-forming material has little effect on the midspan node speed and acceleration response of prestressed concrete beams
Concordance between microsatellite instability and mismatch repair protein expression in colorectal cancer and their clinicopathological characteristics: a retrospective analysis of 502 cases
Microsatellite instability (MSI) is one of the hallmarks of colorectal cancer (CRC). Mismatch repair (MMR) protein expression may reflect MSI status. To analyze the concordance between MSI and MMR expression in CRC and their clinicopathological characteristics, 502 CRC patients were retrospectively collected in this study. Polymerase chain reaction-capillary electrophoresis (PCR-CE) was used to measure MSI, and MMR expression was determined by immunohistochemistry (IHC). The causes of non-concordance were analyzed. Chi-square test was used to find the correlation between MSI and various clinicopathological parameters. PCR-CE results showed 64 (12.7%) patients had high microsatellite instability (MSI-H); low microsatellite instability (MSI-L) and microsatellite stable (MSS) cases were 19 (3.8%)and 419 (83.5%), respectively. With regard to IHC, 430 (85.7%) showed proficient mismatch repair (pMMR) and 72 (14.3%) showed deficient mismatch repair (dMMR). The coincidence rate of MSI and MMR expression in CRC was 98.4% (494/502), with good concordance (Kappa = 0.932). Using PCR-CE as the gold standard, the sensitivity, specificity, positive predictive value, and negative predictive value of IHC were 100%, 98.2%, 88.9%, and 100%, respectively. MSI-H was more common in women, right colon, tumors ≥ 5 cm, ulcerative type, mucinous adenocarcinoma, poor differentiation, T stage I/II, and without lymph node or distant metastasis for CRC patients. In summary, MSI exhibited some typical clinicopathological characteristics. MSI and MMR expression in CRC had good concordance. However, it is still extremely necessary to perform PCR-CE. We recommend that testing packages of different sizes should be developed in clinical practice to create a testing echelon, to facilitate comprehensive selection according to experimental conditions, clinical diagnosis, and treatment needs
Transport model analysis of the transverse momentum and rapidity dependence of pion interferometry at SPS energies
Based on the UrQMD transport model, the transverse momentum and the rapidity
dependence of the Hanbury-Brown-Twiss (HBT) radii , , as well
as the cross term at SPS energies are investigated and compared with
the experimental NA49 and CERES data. The rapidity dependence of the ,
, is weak while the is significantly increased at large
rapidities and small transverse momenta. The HBT "life-time" issue (the
phenomenon that the calculated value is larger than
the correspondingly extracted experimental data) is also present at SPS
energies.Comment: 17 pages, 11 figure
Comparison of regime‐sorted tropical cloud profiles observed by CloudSat with GEOS5 analyses and two general circulation model simulations
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94863/1/jgrd16832.pd
Potent neutralization of SARS-CoV-2 by human antibody heavy-chain variable domains isolated from a large library with a new stable scaffold
Effective therapies are urgently needed for COVID-19. Here we describe the identification of a new stable
human immunoglobulin G1 heavy-chain variable (VH) domain scaffold that was used for the construction
of a large library, lCAT6, of engineered human VHs. This library was panned against the receptor-binding
domain (RBD) of the SARS-CoV-2 spike (S) glycoprotein. Two VH domains (VH ab6 and VH m397) were
selected and fused to Fc for increased half-life in circulation. The VH-Fc ab6 and m397 specifically
neutralized SARS-CoV-2 with high potencies (50% neutralization at 0.35 μg/ml and 1.5 μg/ml, respectively)
as measured by two independent replication-competent virus neutralization assays. Ab6 and m397
competed with ACE2 for binding to RBD, suggesting a competitive mechanism of virus neutralization.
These VH domains may have potential applications for prophylaxis and therapy of COVID-19 alone or in
combination, as well as for diagnosis and as tools for research
Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR
Substantial experimental and theoretical efforts worldwide are devoted to
explore the phase diagram of strongly interacting matter. At LHC and top RHIC
energies, QCD matter is studied at very high temperatures and nearly vanishing
net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was
created at experiments at RHIC and LHC. The transition from the QGP back to the
hadron gas is found to be a smooth cross over. For larger net-baryon densities
and lower temperatures, it is expected that the QCD phase diagram exhibits a
rich structure, such as a first-order phase transition between hadronic and
partonic matter which terminates in a critical point, or exotic phases like
quarkyonic matter. The discovery of these landmarks would be a breakthrough in
our understanding of the strong interaction and is therefore in the focus of
various high-energy heavy-ion research programs. The Compressed Baryonic Matter
(CBM) experiment at FAIR will play a unique role in the exploration of the QCD
phase diagram in the region of high net-baryon densities, because it is
designed to run at unprecedented interaction rates. High-rate operation is the
key prerequisite for high-precision measurements of multi-differential
observables and of rare diagnostic probes which are sensitive to the dense
phase of the nuclear fireball. The goal of the CBM experiment at SIS100
(sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD
matter: the phase structure at large baryon-chemical potentials (mu_B > 500
MeV), effects of chiral symmetry, and the equation-of-state at high density as
it is expected to occur in the core of neutron stars. In this article, we
review the motivation for and the physics programme of CBM, including
activities before the start of data taking in 2022, in the context of the
worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal
High Potency of a Bivalent Human VH Domain in SARS-CoV-2 Animal Models
Novel COVID-19 therapeutics are urgently needed. We generated a phage-displayed human antibody VH
domain library from which we identified a high-affinity VH binder ab8. Bivalent VH, VH-Fc ab8, bound with
high avidity to membrane-associated S glycoprotein and to mutants found in patients. It potently neutralized
mouse-adapted SARS-CoV-2 in wild-type mice at a dose as low as 2 mg/kg and exhibited high prophylactic
and therapeutic efficacy in a hamster model of SARS-CoV-2 infection, possibly enhanced by its relatively
small size. Electron microscopy combined with scanning mutagenesis identified ab8 interactions with all
three S protomers and showed how ab8 neutralized the virus by directly interfering with ACE2 binding. VHFc
ab8 did not aggregate and did not bind to 5,300 human membrane-associated proteins. The potent
neutralization activity of VH-Fc ab8 combined with good developability properties and cross-reactivity to
SARS-CoV-2 mutants provide a strong rationale for its evaluation as a COVID-19 therapeutic
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