Excitation functions of proton-proton elastic cross sections have been measured in narrow momentum steps
Δp = 28 MeV/c in the kinetic energy range from 0.5 to 2.5 GeV and the angular range 35° ≤
Θ
cm
...≤ 90° with a detector providing
ΔΘ
cm
≈ 1.4° resolution and 82% solid angle coverage. Measurements have been performed continuously during projectile acceleration in the Cooler Synchrotron COSY with an internal CH
2 fiber target; background corrections were derived from measurements with a carbon fiber target and from Monte Carlo simulations of inelastic pp contributions. Particular care was taken to monitor the luminosity as a function of beam energy. The results provide excitation functions and angular distributions of unprecedented precision and internal consistency. The measured cross sections are compared to recent phase shift analyses, and their impact on the present solution SM97 1 is discussed.
Superconductive test cavity for the ESS Brautigam, W.; Felden, O.; Glende, M. ...
PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268),
2001, Letnik:
2
Conference Proceeding
Odprti dostop
Measurements at the prototype cavity were performed at the FZJ Julich in order to support the design work of the SC accelerator part for the European Spallation Source (ESS). A shielded test facility ...has been constructed providing 25kW peak RF power operating at 500MHz. The test cavity has been fabricated at ACCEL Instruments and was installed into the shielded area. This 5-cell cavity has been designed to a /spl beta/ value of 0.75 at an accelerating field of E/sub acc/ > 5MV/m with Q/sub 0/ = 2 /spl times/ 10/sup 9/, operating at 4.2K. We have developed a cavity control circuit based on a fast analogue phase-lock loop allowing automated measurements. The first quasi static measurements using a 500W broadband amplifier almost verified the design values of Q/sub 0/ and E/sub acc/. The piezoelectric tuning system was used to record the spectrum of mechanical resonances of the cavity. A comparison of several computer simulations with measured results is presented. Furthermore, we have taken dynamical data of the Lorentz force detuning during pulsed-mode operation at a repetition rate of 50Hz. First results achieved with an active compensation of the Lorentz force detuning using the fast piezo frequency control system are also presented.
Phys.Rev.Lett. 90 (2003) 142301 At the Cooler Synchrotron COSY/J\"ulich spin correlation parameters in
elastic proton-proton (pp) scattering have been measured with a 2.11 GeV
polarized proton beam ...and a polarized hydrogen atomic beam target. We report
results for A$_{NN}$, A$_{SS}$, and A_${SL}$ for c.m. scattering angles between
30$^o$ and 90$^o$. Our data on A$_{SS}$ -- the first measurement of this
observable above 800 MeV -- clearly disagrees with predictions of available of
pp scattering phase shift solutions while A$_{NN}$ and A_${SL}$ are reproduced
reasonably well. We show that in the direct reconstruction of the scattering
amplitudes from the body of available pp elastic scattering data at 2.1 GeV the
number of possible solutions is considerably reduced.
This study analyzed the associations between physical activity (PA) and motor proficiency (MP) to determine what level of moderate PA might help avoid low MP in 8-10-year-old Brazilian children. We ...assessed MP of 98 children using the Bruininks-Oseretsky Motor Proficiency, Second Edition Short Form (BOT-2 SF), and we assessed PA using the GT3X + accelerometer. We analyzed data using means, standard deviations, frequency distribution, spearman correlation coefficients, Mann–Whitney U test, and the Receiver Operating Characteristics curve. There was a difference between groups of children with adequate or better versus low MP in minutes/day of moderate PA (defined as 2,296–4,011 accelerometer counts/minute; U = 666.0, p = .045) such that those with less time engaged in moderate PA had lower MP scores than peers with adequate MP. There was also a positive correlation between moderate PA and the strength and agility MP domain (rs = .226; p = .025). In addition, minutes/day of moderate PA less than or equal to 142.56 minutes showed predictive capacity for low MP (area under the curve = 0.635; p = .027). Thus, objective measures of PA were able to predict low MP in 8-10-year-old Brazilian children, with an approximate guideline of about 2.5 hours per day of moderate PA needed to protect against low MP.
At the Cooler Synchrotron COSY/J\"ulich spin correlation parameters in elastic proton-proton (pp) scattering have been measured with a 2.11 GeV polarized proton beam and a polarized hydrogen atomic ...beam target. We report results for A\(_{NN}\), A\(_{SS}\), and A_\({SL}\) for c.m. scattering angles between 30\(^o\) and 90\(^o\). Our data on A\(_{SS}\) -- the first measurement of this observable above 800 MeV -- clearly disagrees with predictions of available of pp scattering phase shift solutions while A\(_{NN}\) and A_\({SL}\) are reproduced reasonably well. We show that in the direct reconstruction of the scattering amplitudes from the body of available pp elastic scattering data at 2.1 GeV the number of possible solutions is considerably reduced.
PD-1 immune checkpoint inhibitors have produced encouraging results in patients with hepatocellular carcinoma (HCC). However, what determines resistance to anti-PD-1 therapies is unclear. We created ...a novel genetically engineered mouse model of HCC that enables interrogation of how different genetic alterations affect immune surveillance and response to immunotherapies. Expression of exogenous antigens in
HCCs led to T cell-mediated immune surveillance, which was accompanied by decreased tumor formation and increased survival. Some antigen-expressing
HCCs escaped the immune system by upregulating the β-catenin (CTNNB1) pathway. Accordingly, expression of exogenous antigens in
HCCs had no effect, demonstrating that β-catenin promoted immune escape, which involved defective recruitment of dendritic cells and consequently impaired T-cell activity. Expression of chemokine CCL5 in antigen-expressing
HCCs restored immune surveillance. Finally, β-catenin-driven tumors were resistant to anti-PD-1. In summary, β-catenin activation promotes immune escape and resistance to anti-PD-1 and could represent a novel biomarker for HCC patient exclusion. SIGNIFICANCE: Determinants of response to anti-PD-1 immunotherapies in HCC are poorly understood. Using a novel mouse model of HCC, we show that β-catenin activation promotes immune evasion and resistance to anti-PD-1 therapy and could potentially represent a novel biomarker for HCC patient exclusion.
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We report on the neutrino mass measurement result from the first four-week science run of the Karlsruhe Tritium Neutrino experiment KATRIN in spring 2019. Beta-decay electrons from a high-purity ...gaseous molecular tritium source are energy analyzed by a high-resolution MAC-E filter. A fit of the integrated electron spectrum over a narrow interval around the kinematic end point at 18.57 keV gives an effective neutrino mass square value of (-1.0_{-1.1}^{+0.9}) eV^{2}. From this, we derive an upper limit of 1.1 eV (90% confidence level) on the absolute mass scale of neutrinos. This value coincides with the KATRIN sensitivity. It improves upon previous mass limits from kinematic measurements by almost a factor of 2 and provides model-independent input to cosmological studies of structure formation.
Maladaptive remodelling of the arterial wall after mechanical injury (e. g. angioplasty) is characterised by inflammation, neointima formation and media hypertrophy, resulting in narrowing of the ...affected artery. Moreover, mechanical injury of the arterial wall causes loss of the vessel protecting endothelial cell monolayer. Mitogen-activated protein kinase (MAPK)-activated protein kinase 2 (MK2), a major downstream target of p38 MAPK, regulates inflammation, cell migration and proliferation, essential processes for vascular remodelling and re-endothelialisation. Therefore, we investigated the role of MK2 in remodelling and re-endothelialisation after arterial injury in genetically modified mice in vivo. Hypercholesterolaemic low-density-lipoprotein-receptor-deficient mice (ldlr-/-) were subjected to wire injury of the common carotid artery. MK2-deficiency (ldlr-/-/mk2-/-) nearly completely prevented neointima formation, media hypertrophy, and lumen loss after injury. This was accompanied by reduced proliferation and migration of MK2-deficient smooth muscle cells. In addition, MK2-deficiency severely reduced monocyte adhesion to the arterial wall (day 3 after injury, intravital microscopy), which may be attributed to reduced expression of the chemokine ligands CCL2 and CCL5. In line, MK2-deficiency significantly reduced the content of monocytes, neutrophiles and lymphocytes of the arterial wall (day 7 after injury, flow cytometry). In conclusion, in a model of endothelial injury (electric injury), MK2-deficiency strongly increased proliferation of endothelial cells and improved re-endothelialisation of the arterial wall after injury. Deficiency of MK2 prevents adverse remodelling and promotes endothelial healing of the arterial wall after injury, suggesting that MK2-inhibition is a very attractive intervention to prevent restenosis after percutaneous therapeutic angioplasty.
We report on the light sterile neutrino search from the first four-week science run of the KATRIN experiment in 2019. Beta-decay electrons from a high-purity gaseous molecular tritium source are ...analyzed by a high-resolution MAC-E filter down to 40 eV below the endpoint at 18.57 keV. We consider the framework with three active neutrinos and one sterile neutrino. The analysis is sensitive to the mass, m_{4}, of the fourth mass state for m_{4}^{2}≲1000 eV^{2} and to active-to-sterile neutrino mixing down to |U_{e4}|^{2}≳2×10^{-2}. No significant spectral distortion is observed and exclusion bounds on the sterile mass and mixing are reported. These new limits supersede the Mainz results for m_{4}^{2}≲1000 eV^{2} and improve the Troitsk bound for m_{4}^{2}<30 eV^{2}. The reactor and gallium anomalies are constrained for 100<Δm_{41}^{2}<1000 eV^{2}.
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