A recent report has demonstrated a stronger association between the HLA-DQA1*0501 allele and Graves' disease in Caucasian men than in women. Our aim was to confirm this association in a larger series ...of male Caucasian patients.
Polymerase chain reaction/sequence specific oligonucleotide probing (PCR/SSOP).
Fifty men and 70 women with Graves' disease were studied as well as a control group consisting of 57 healthy, unrelated men and women.
Genomic DNA was derived from venous blood samples. Appropriately primed DNA was amplified by PCR and the products were subjected to SSOP. The presence of the allele was demonstrated by enhanced chemiluminescence.
A significant association between HLA-DQA1*0501 and Graves' disease was demonstrated among both the men and women as well as in the combined disease cohort, with HLA-DQA1*0501 conferring a greater relative risk than HLA-DR3 in all three groups. This association persisted when the results from the DR3-negative Graves' patients were analysed in isolation. HLA-DQA1*0501 was heterogeneously distributed between the sexes with significantly more female Graves' patients carrying this allele.
There is a significant association between HLA-DQA1*0501 and Graves' disease which may be unrelated to the inheritance of this allele on an extended haplotype with HLA-DR3. In contrast to a recent report, HLA-DQA1*0501 was significantly more prevalent among women with Graves' disease than men.
Using a sample of 383 x 10;{6} BBover events collected by the BABAR experiment, we measure sums of seven exclusive final states B-->X_{d(s)}gamma, where X_{d}(X_{s}) is a nonstrange (strange) ...charmless hadronic system in the mass range 0.6-1.8 GeV/c;{2}. After correcting for unmeasured decay modes in this mass range, we obtain a branching fraction for b-->dgamma of (7.2+/-2.7(stat)+/-2.3(syst))x10;{-6}. Taking the ratio of X_{d} to X_{s} we find Gamma(b-->dgamma)/Gamma(b-->sgamma)=0.033+/-0.013(stat)+/-0.009(syst), from which we determine |V_{td}/V_{ts}|=0.177+/-0.043.
Purpose : To determine the capacity of ionizing radiation to inhibit proliferation, to suppress c- myc expression and to induce apoptotic cell death in the p53 wild-type MCF-7 cell line and the p53 ...mutated MDA-MB231 cell line. Materials and methods : Growth inhibition and cell killing were determined by cell number and trypan blue exclusion. Apoptosis was assessed through cell morphology and fluorescent endlabelling. c- myc expression was monitored by Northern blotting. Results : Inhibition of cell proliferation by ionizing radiation was similar in both cell lines. MDA-MB231 cells accumulated in G2 while MCF-7 cells accumulated in both the G1 and G2 phases of the cell cycle after irradiation. There was no evidence of apoptosis in either cell line. In MCF-7 cells, growth inhibition correlated closely with an early dose-dependent suppression of c- myc expression; in MDA-MB231 cells, there was no correspondence between growth inhibition and a transient, dose- independent reduction in c- myc message. Conclusions : These findings suggest that in the absence of classical apoptotic cell death, radiosensitivity is not predictably related to the p53 status of the cell. While both p53 and c- myc may be linked to the DNA damage response pathway, neither p53 nor c- myc are essential for growth arrest in response to ionizing radiation.
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Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We present improved measurements of the branching fraction B, the longitudinal polarization fraction f{L}, and the direct CP asymmetry A{CP} in the B meson decay channel B;{+}-->rho;{+}rho;{0}. The ...data sample was collected with the BABAR detector at SLAC. The results are B(B;{+}-->rho;{+}rho;{0})=(23.7+/-1.4+/-1.4) x 10;{-6}, f{L}=0.950+/-0.015+/-0.006, and A{CP}=-0.054+/-0.055+/-0.010, where the uncertainties are statistical and systematic, respectively. Based on these results, we perform an isospin analysis and determine the Cabibbo-Kobayashi-Maskawa phase angle alpha=arg(-V{td}V{tb};/V{ud}V{ub}) to be (92.4{-6.5};{+6.0}) degrees.
Data collected around $\sqrt{s}=91$ GeV by the OPAL experiment at the LEP e super(+)e super(-) collider are used to study the mechanism of baryon formation. As the signature, the fraction of super(-) ...hyperons whose baryon number is compensated by the production of a $\overline{\Sigma,\overline{\Lambda}$ or $\overline{\Xi$ antihyperon is determined. The method relies entirely on quantum number correlations of the baryons, and not rapidity correlations, making it more model independent than previous studies. Within the context of the JETSET implementation of the string hadronization model, the diquark baryon production model without the popcorn mechanism is strongly disfavored with a significance of 3.8 standard deviations including systematic uncertainties. It is shown that previous studies of the popcorn mechanism with $\Lambda \overline{\Lambda}$ and $\mathrm{p}\pi \overline{\mathrm{p}}$ correlations are not conclusive, if parameter uncertainties are considered.
In a search for B-->ccover gammaK decays with the BABAR detector, where ccover includes J/psi and psi(2S), and K includes K(+/-), K(S)(0), and K(*)(892), we find evidence for X(3872)-->J/psigamma ...and X(3872)-->psi(2S)gamma with 3.6sigma and 3.5sigma significance, respectively. We measure the product of branching fractions B(B(+/-)-->X(3872)K(+/-))xB(X(3872)-->J/psigamma)=2.8+/-0.8(stat)+/-0.1(syst)x10(-6) and B(B(+/-)-->X(3872)K(+/-))xB(X(3872)-->psi(2S)gamma)=9.5+/-2.7(stat)+/-0.6(syst)x10(-6).
The fundamental building blocks of the proton, quarks and gluons, have been known for decades. However, we still have an incomplete theoretical and experimental understanding of how these particles ...and their dynamics give rise to the quantum bound state of the proton and its physical properties, such as for example its spin. The two up and the single down quarks that comprise the proton in the simplest picture account only for a few percent of the proton mass, the bulk of which is in the form of quark kinetic and potential energy and gluon energy from the strong force. An essential feature of this force, as described by quantum chromodynamics, is its ability to create matter-antimatter quark pairs inside the proton that exist only for a very short time. Their fleeting existence makes the antimatter quarks within protons difficult to study, but their existence is discernible in reactions where a matter-antimatter quark pair annihilates. In this picture of quark-antiquark creation by the strong force, the probability distributions as a function of momentum for the presence of up and down antimatter quarks should be nearly identical, since their masses are quite similar and small compared to the mass of the proton. In the present manuscript, we show evidence from muon pair production measurements that these distributions are significantly different, with more abundant down antimatter quarks than up antimatter quarks over a wide range of momentum. These results revive interest in several proposed mechanisms as the origin of this antimatter asymmetry in the proton that had been disfavored by the previous results and point to the future measurements that can distinguish between these mechanisms.
We present measurements of branching fractions and charge asymmetries for six B -meson decay modes with an η or η ′ meson in the final state. The data sample corresponds to 232 × 10 6 B ¯¯¯ B pairs ...collected with the BABAR detector at the PEP-II asymmetric-energy e + e − B Factory at SLAC. We measure the branching fractions (in units of 10 − 6 ): B ( B + → η π + ) = 5.1 ± 0.6 ± 0.3 , B ( B + → η K + ) = 3.3 ± 0.6 ± 0.3 , B ( B 0 → η K 0 ) = 1.5 ± 0.7 ± 0.1 ( < 2.5 at 90% C.L.), B ( B + → η ρ + ) = 8.4 ± 1.9 ± 1.1 , B ( B 0 → η ω ) = 1.0 ± 0.5 ± 0.2 ( < 1.9 at 90% C.L.), and B ( B + → η ′ π + ) = 4.0 ± 0.8 ± 0.4 , where the first uncertainty is statistical and second systematic. For the charged modes we also determine the charge asymmetries, all found to be compatible with zero.
Two-phase xenon detectors, such as that at the core of the forthcoming LZ dark matter experiment, use photomultiplier tubes to sense the primary (S1) and secondary (S2) scintillation signals ...resulting from particle interactions in their liquid xenon target. This paper describes a simulation study exploring two techniques to lower the energy threshold of LZ to gain sensitivity to low-mass dark matter and astrophysical neutrinos, which will be applicable to other liquid xenon detectors. The energy threshold is determined by the number of detected S1 photons; typically, these must be recorded in three or more photomultiplier channels to avoid dark count coincidences that mimic real signals. To lower this threshold: a) we take advantage of the double photoelectron emission effect, whereby a single vacuum ultraviolet photon has a \(\sim20\%\) probability of ejecting two photoelectrons from a photomultiplier tube photocathode; and b) we drop the requirement of an S1 signal altogether, and use only the ionization signal, which can be detected more efficiently. For both techniques we develop signal and background models for the nominal exposure, and explore accompanying systematic effects, including the dependence on the free electron lifetime in the liquid xenon. When incorporating double photoelectron signals, we predict a factor of \(\sim 4\) sensitivity improvement to the dark matter-nucleon scattering cross-section at \(2.5\) GeV/c\(^2\), and a factor of \(\sim1.6\) increase in the solar \(^8\)B neutrino detection rate. Dropping the S1 requirement may allow sensitivity gains of two orders of magnitude in both cases. Finally, we apply these techniques to even lower masses by taking into account the atomic Migdal effect; this could lower the dark matter particle mass threshold to \(80\) MeV/c\(^2\).
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