Advanced prosthetic valve endocarditis is often associated with substantial destruction of the tissues adjacent to the prosthesis. Removal of the infected prosthesis and débridement of the infected ...tissues make implantation of a new prosthesis challenging. Herein, we discuss successful surgical aortic valve translocation in a 50-year-old man who had advanced acute prosthetic valve endocarditis with destruction of the aortic annulus. One year after being discharged from the hospital, the patient was asymptomatic with good exercise tolerance.
Total cross sections, angular distributions, and invariant-mass distributions have been measured for the photoproduction of \(\pi^0\pi^0\) pairs off free protons and off nucleons bound in the ...deuteron. The experiments were performed at the MAMI accelerator facility in Mainz using the Glasgow photon tagging spectrometer and the Crystal Ball/TAPS detector. The accelerator delivered electron beams of 1508 and 1557~MeV, which produced bremsstrahlung in thin radiator foils. The tagged photon beam covered energies up to 1400~MeV. The data from the free proton target are in good agreement with previous measurements and were only used to test the analysis procedures. The results for differential cross sections (angular distributions and invariant-mass distributions) for free and quasi-free protons are almost identical in shape, but differ in absolute magnitude up to 15\%. Thus, moderate final-state interaction effects are present. The data for quasi-free neutrons are similar to the proton data in the second resonance region (final state invariant masses up to \(\approx\)1550~MeV), where both reactions are dominated by the \(N(1520)3/2^-\rightarrow \Delta(1232)3/2^+\pi\) decay. At higher energies, angular and invariant-mass distributions are different. A simple analysis of the shapes of the invariant-mass distributions in the third resonance region is consistent with strong contributions of an \(N^{\star}\rightarrow N\sigma\) decay for the proton, while the reaction is dominated by a sequential decay via a \(\Delta\pi\) intermediate state for the neutron. The data are compared to predictions from the Two-Pion-MAID model and the Bonn-Gatchina coupled channel analysis.
Phys. Rev. B 107, 144420 (2023) MnSb$_{2}$O$_{6}$ is based on the noncentrosymmetric $P321$ space group with
magnetic Mn$^{2+}$ ($S={5/2}$, $L\approx 0$) spins ordering below
$T_{\mathrm{N}}=12$ K in ...a helicoidal structure. The ground state magnetic
structure, expected to be built and originate from 7 Heisenberg exchange
constants, has been shown to be coupled to the underlying crystallographic
chirality with polar domain switching being reported. We apply neutron
spectroscopy to extract these symmetric exchange constants. Given the high
complexity of the magnetic exchange network, crystallographic structure and
complications fitting linear spin-wave models, we take advantage of multiplexed
neutron instrumentation to use the first moment sum rule of neutron scattering
to estimate the 7 exchange constants. We then use these parameters to calculate
the low-energy spin-waves in the N\'eel state to reproduce the neutron response
without strong antisymmetric coupling. Using Green's response functions, the
stability of long-wavelength excitations in the context of proposed magnetic
structures is then discussed. The results show the presence of strong exchange
constants for the chiral exchange pathways and illustrate an underlying
coupling between crystallographic and magnetic ``chirality" through
predominantely symmetric exchange.
From the Grampian region of Scotland, 198 patients with MS and 128 normal individuals were typed for allotypes of the Gm system which encode for the constant region of IgG heavy chains. No ...significant independent association between a given Gm allotype or phenotype and susceptibility to MS was observed for the group of patients from this region. This was also the case when patients were classified according to sex, clinical course, and disease progression. However, a significant association was found between the Gm phenotype, Gm (3;5, 10, 11, 13, 14), and HLA DQwl in patients with MS. The relative risk of developing MS for individuals who carried both Gm (3;5,10, 11,13,14) and HLA DQwl was nearly five times greater than for individuals with neither determinant. These findings suggest that in the presence of HLA DQwl, genes associated with the Gm (3;5,10,11,13,14) phenotype have an important contributory influence on susceptibility to MS. The additive effects of Gm and HLA on susceptibility to MS would be one possible reason for the lack of a complete association between MS and a single genetic locus.
Bone marrow transplantation was performed on an 8-month-old boy who was diagnosed as having fucosidosis following the diagnosis of the disease in his older brother. Although he was asymptomatic and ...his development was normal, abnomalities were found on an MRI scan prior to transplant. In the absence of a suitable related donor, an unrelated volunteer donor was used. Conditioning for the transplant consisted of busulphan and cyclophosphamide. Graft-versus-host disease prophylaxis consisted of in vitro T cell-depletion of the bone marrow and in vivo administration of cyclosporin. The post-transplant period was complicated by moderately severe graft-versus-host disease. Engraftment was documented by the presence of donor levels of alpha-fucosidase, donor blood group and tissue type (difference in the DQ antigen), and chromosomal polymorphism pattern of donor origin. Eighteen months after transplant, there is evidence of mild neurodevelopmental delay. By contrast, his elder sibling showed far greater developmental delay at the same age. The patient's MRI scan shows improvement. We believe this to be the first case of human fucosidosis treated by bone marrow transplantation.
Following Tn5 mutagenesis of Rhizobium leguminosarum biovar viciae, two mutants in one complementation group were identified as being unable to fix nitrogen in pea nodules. Spectroscopic analysis ...revealed that the mutants had lowered levels of c-type cytochromes and cytochromes aa3, but increased levels of cytochrome d. Cells of the mutants were greatly reduced in their ability to oxidize the artificial electron donor N,N,N',N'-tetramethyl-p-phenylenediamine but membranes prepared from them had increased levels of succinate- and NADH-dependent respiration. NADH oxidation by the mutants was insensitive to the respiratory inhibitor antimycin A, that targets the cytochrome bc1 complex. Molecular analysis of the mutants revealed that they were affected in the cytochrome bc1 complex. One of the mutants contained Tn5 in a gene homologous to that encoding cytochrome c1, and in the other the Tn5 was in DNA homologous to that encoding the cytochrome b component of the cytochrome bc1 complex. Haem staining revealed that haem proteins of M(r)31,000 and M(r)23,000 were absent from membranes from the mutants whereas an additional soluble c-type cytochrome protein of M(r)23,000 was present. We conclude that the larger of these two haem proteins corresponds to cytochrome c1 and, in its absence, the protein of M(r)23,000 does not remain associated with the membrane. Formation of this M(r)23,000 component was specifically blocked in a third respiratory-defective mutant which contained Tn5 in a region of DNA showing homology to a Bradyrhizobium Japonicum gene previously shown to encode the membrane-bound c-type cytochrome CycM. Although the cytochrome bc1 complex is essential for symbiotic nitrogen fixation, the other membrane-bound c-type cytochrome (CycM) is not.
An experimental study of \(\omega\) photoproduction on the proton was conducted by using the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz ...Microtron MAMI. The \(\gamma p\to\omega p\) differential cross sections are measured from threshold to the incident-photon energy \(E_\gamma=1.40\) GeV (\(W=1.87\) GeV for the center-of-mass energy) with 15-MeV binning in \(E_\gamma\) and full production-angle coverage. The quality of the present data near threshold gives access to a variety of interesting physics aspects. As an example, an estimation of the \(\omega N\) scattering length \(\alpha_{\omega p}\) is provided.
The first data on target and beam-target asymmetries for the \(\gamma p\to\pi^0\eta p\) reaction at photon energies from 1050 up to 1450 MeV are presented. The measurements were performed using the ...Crystal Ball and TAPS detector setup at the Glasgow tagged photon facility of the Mainz Microtron MAMI. The general assumption that the reaction is dominated by the \(\Delta 3/2^-\) amplitude is confirmed. The data are in particular sensitive to small contributions from other partial waves.
A new data set for the helicity-dependent differential cross section of the
single-meson photoproduction reaction $\gamma p \to p \pi^{0}$ was obtained for
the photon energy interval 150-400 MeV. The ...experiment was performed at the A2
tagged photon facility of the Mainz Microtron MAMI using a circularly polarized
photon beam and a longitudinally polarized proton target. The reaction products
were detected with the large acceptance Crystal Ball/TAPS calorimeter covering
97\% of the full solid angle. These new results, obtained with a fine energy
and polar angle binning, greatly increase both the existing quantity and
quality of the data available for this observable. A moment analysis, based on
a finite expansion in Legendre polynomials, was applied to these data by using
a bootstrap-based fitting method to correctly account for their systematic
uncertainties. From the resulting decomposition of the differential cross
sections, the $E2/M1$ ratio for the $N\to \Delta(1232)$ transition was
determined to be $-2.38 \pm 0.16{\hbox{ (stat.+sys.)}} \pm 0.10 {\hbox{
(model)}} \%$. Combining this value with previous results also allowed us to
evaluate the most precise available estimate of the $E2/M1$ ratio to be used
for all further reference and model comparisons.
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