2,489 research outputs found
Parathyroid hormone [1-34] improves articular cartilage surface architecture and integration and subchondral bone reconstitution in osteochondral defects in vivo
SummaryObjectiveThe 1-34 amino acid segment of the parathyroid hormone (PTH [1-34]) mediates anabolic effects in chondrocytes and osteocytes. The aim of this study was to investigate whether systemic application of PTH [1-34] improves the repair of non-osteoarthritic, focal osteochondral defects in vivo.DesignStandardized cylindrical osteochondral defects were bilaterally created in the femoral trochlea of rabbits (n = 8). Daily subcutaneous injections of 10 Όg PTH [1-34]/kg were given to the treatment group (n = 4) for 6 weeks, controls (n = 4) received saline. Articular cartilage repair was evaluated by macroscopic, biochemical, histological and immunohistochemical analyses. Reconstitution of the subchondral bone was assessed by micro-computed tomography. Effects of PTH [1-34] on synovial membrane, apoptosis, and expression of the PTH receptor (PTH1R) were determined.ResultsSystemic PTH [1-34] increased PTH1R expression on both, chondrocytes and osteocytes within the repair tissue. PTH [1-34] ameliorated the macro- and microscopic aspect of the cartilaginous repair tissue. It also enhanced the thickness of the subchondral bone plate and the microarchitecture of the subarticular spongiosa within the defects. No significant correlations were established between these coexistent processes. Apoptotic levels, synovial membrane, biochemical composition of the repair tissue, and type-I/II collagen immunoreactivity remained unaffected.ConclusionsPTH [1-34] emerges as a promising agent in the treatment of focal osteochondral defects as its systemic administration simultaneously stimulates articular cartilage and subchondral bone repair. Importantly, both time-dependent mechanisms of repair did not correlate significantly at this early time point and need to be followed over prolonged observation periods
Inelastic interaction mean free path of negative pions in tungsten
The inelastic interaction mean free paths lambda of 5, 10, and 15 GeV/c pions were measured by determining the distribution of first interaction locations in a modular tungsten-scintillator ionization spectrometer. In addition to commonly used interaction signatures of a few (2-5) particles in two or three consecutive modules, a chi2 distribution is used to calculate the probability that the first interaction occurred at a specific depth in the spectrometer. This latter technique seems to be more reliable than use of the simpler criteria. No significant dependence of lambda on energy was observed. In tungsten, lambda for pions is 206 plus or minus 6 g/sq cm
Minimal-invasive anterior approach to the hip provides a better surgery-related and early postoperative functional outcome than conventional lateral approach after hip hemiarthroplasty following femoral neck fractures
Introduction Femoral neck fractures (FNF) are one of the most frequent fractures among elderly patients and commonly
require surgical treatment. Bipolar hip hemiarthroplasty (BHHA) is mostly performed in these cases.
Material and methods In the present retrospective study geriatric patients with FNF (n=100) treated either by anterior
minimal-invasive surgery (AMIS; n=50) or lateral conventional surgery (LCS; n=50) were characterized (age at the time
of surgery, sex, health status/ASA score, walking distance and need for walking aids before the injury) and intraoperative
parameters (duration of surgery, blood loss, complications), as well as postoperative functional performance early (duration
of in-patient stay, radiological leg length discrepancy, ability to full weight-bearing, mobilization with walking aids) and
12 months (radiological signs of sintering, clinical parameters, complication rate) after surgery were analyzed.
Results Patients in the AMIS group demonstrated a reduced blood loss intraoperatively, while the duration of surgery and
complication rates did not difer between the two groups. Further, more patients in the AMIS group achieved full weightbearing of the injured leg and were able to walk with a rollator or less support during their in-patient stay. Of interest, patients
in the AMIS group achieved this level of mobility earlier than those of the LCS group, although their walking distance before
the acute injury was reduced. Moreover, patients of the AMIS group showed equal leg lengths postoperatively more often
than patients of the LCS group. No signifcant diferences in functional and surgery-related performance could be observed
between AMIS and LCS group at 12 months postoperatively.
Conclusions In conclusion, geriatric patients treated by AMIS experience less surgery-related strain and recover faster in
the early postoperative phase compared to LCS after displaced FNF. Hence, AMIS should be recommended for BHHA in
these vulnerable patients
Magnetic crystalline-symmetry-protected axion electrodynamics and field-tunable unpinned Dirac cones in EuIn2As2
Knowledge of magnetic symmetry is vital for exploiting nontrivial surface
states of magnetic topological materials. EuInAs is an excellent
example, as it is predicted to have collinear antiferromagnetic order where the
magnetic moment direction determines either a topological-crystalline-insulator
phase supporting axion electrodynamics or a higher-order-topological-insulator
phase with chiral hinge states. Here, we use neutron diffraction, symmetry
analysis, and density functional theory results to demonstrate that
EuInAs actually exhibits low-symmetry helical antiferromagnetic
order which makes it a stoichiometric magnetic topological-crystalline axion
insulator protected by the combination of a 180 rotation and
time-reversal symmetries: . Surfaces
protected by are expected to have an exotic gapless Dirac cone
which is unpinned to specific crystal momenta. All other surfaces have gapped
Dirac cones and exhibit half-integer quantum anomalous Hall conductivity. We
predict that the direction of a modest applied magnetic field of to
T can tune between gapless and gapped surface states.Comment: 49 pages, 26 figure
The structure of the Shiga toxin 2a A-subunit dictates the interactions of the toxin with blood components
Hemolytic uremic syndrome (eHUS) is a severe complication of human infections with Shiga toxins (Stxs)-producing Escherichia coli. A key step in the pathogenesis of eHUS is the interaction of Stxs with blood components before the targeting of renal endothelial cells. Here, we show that a single proteolytic cleavage in the Stx2a A-subunit, resulting into two fragments (A1 and A2) linked by a disulfide bridge (cleaved Stx2a), dictates different binding abilities. Uncleaved Stx2a was confirmed to bind to human neutrophils and to trigger leukocyte/platelet aggregate formation, whereas cleaved Stx2a was ineffective. Conversely, binding of complement factor H was confirmed for cleaved Stx2a and not for uncleaved Stx2a. It is worth noting that uncleaved and cleaved Stx2a showed no differences in cytotoxicity for Vero cells or Raji cells, structural conformation, and contaminating endotoxin. These results have been obtained by comparing two Stx2a batches, purified in different laboratories by using different protocols, termed Stx2a(cl; cleaved toxin, Innsbruck) and Stx2a(uncl; uncleaved toxin, Bologna). Stx2a(uncl) behaved as Stx2a(cl) after mild trypsin treatment. In this light, previous controversial results obtained with purified Stx2a has to be critically re-evaluated; furthermore, characterisation of the structure of circulating Stx2a is mandatory to understand eHUS-pathogenesis and to develop therapeutic approaches
OC-0441: Genomic amplification of FancA in HNSCC: mechanisms of radioresistance and clinical relevance
Soft capacitor fibers using conductive polymers for electronic textiles
A novel, highly flexible, conductive polymer-based fiber with high electric
capacitance is reported. In its crossection the fiber features a periodic
sequence of hundreds of conductive and isolating plastic layers positioned
around metallic electrodes. The fiber is fabricated using fiber drawing method,
where a multi-material macroscopic preform is drawn into a sub-millimeter
capacitor fiber in a single fabrication step. Several kilometres of fibers can
be obtained from a single preform with fiber diameters ranging between 500um
-1000um. A typical measured capacitance of our fibers is 60-100 nF/m and it is
independent of the fiber diameter. For comparison, a coaxial cable of the
comparable dimensions would have only ~0.06nF/m capacitance. Analysis of the
fiber frequency response shows that in its simplest interrogation mode the
capacitor fiber has a transverse resistance of 5 kOhm/L, which is inversely
proportional to the fiber length L and is independent of the fiber diameter.
Softness of the fiber materials, absence of liquid electrolyte in the fiber
structure, ease of scalability to large production volumes, and high
capacitance of our fibers make them interesting for various smart textile
applications ranging from distributed sensing to energy storage
Tick species from cattle in the Adama Region of Ethiopia and pathogens detected
Ticks will diminish productivity among farm animals and transmit zoonotic diseases. We conducted a study to identify tick species infesting slaughter bulls from Adama City and to screen them for tick-borne pathogens. In 2016, 291 ticks were collected from 37 bulls in Adama, which were ready for slaughter. Ticks were identified morphologically. Total genomic DNA was extracted from ticks and used to test for Rickettsia spp. with real-time PCR. Species identification was done by phylogenetic analysis using sequencing that targeted the 23S-5S intergenic spacer region and ompA genes. Four tick species from two genera, Amblyomma and Rhipicephalus, were identified. Amblyomma cohaerens was the dominant species (n = 241, 82.8%), followed by Amblyomma variegatum (n = 22, 7.5%), Rhipicephalus pulchellus (n = 19, 6.5%), and Rhipicephalus decoloratus (n = 9, 3.0%). Among all ticks, 32 (11%) were positive for Rickettsia spp. and 15 (5.2%) of these were identified as R. africae comprising at least two genetic clades, occurring in A. variegatum (n = 10) and A. cohaerens (n = 5). The remainder of Rickettsia-positive samples could not be amplified due to low DNA yield. Furthermore, another 15 (5.2%) samples carried other pathogenic bacteria: Ehrlichia ruminantium (n = 9; 3.1%) in A. cohaerens, Ehrlichia sp. (n = 3; 1%) in Rh. pulchellus and A. cohaerens, Anaplasma sp. (n = 1; 0.5%) in A. cohaerens, and Neoehrlichia mikurensis (n = 2; 0.7%) in A. cohaerens. All ticks were negative for Bartonella spp., Babesia spp., Theileria spp., and Hepatozoon spp. We reported for the first time E. ruminatium, N. mikurensis, Ehrlichia sp., and Anaplasma sp. in A. cohaerens. Medically and veterinarily important pathogens were mostly detected from A. variegatum and A. cohaerens. These data are relevant for a One-health approach for monitoring and prevention of tick-borne disease transmission
Neutron recognition in the LAND detector for large neutron multiplicity
The performance of the LAND neutron detector is studied. Using an
event-mixing technique based on one-neutron data obtained in the S107
experiment at the GSI laboratory, we test the efficiency of various analytic
tools used to determine the multiplicity and kinematic properties of detected
neutrons. A new algorithm developed recently for recognizing neutron showers
from spectator decays in the ALADIN experiment S254 is described in detail. Its
performance is assessed in comparison with other methods. The properties of the
observed neutron events are used to estimate the detection efficiency of LAND
in this experiment.Comment: 16 pages, 8 figure
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