104 research outputs found
Zu den Faktoren Welche die Adhasion Lichtbogengespritzter Schichten Beeinflussen(Welding Physics, Process & Instrument)
Quantum Kernel t-Distributed Stochastic Neighbor Embedding
Data visualization is important in understanding the characteristics of data
that are difficult to see directly. It is used to visualize loss landscapes and
optimization trajectories to analyze optimization performance. Popular
optimization analysis is performed by visualizing a loss landscape around the
reached local or global minimum using principal component analysis. However,
this visualization depends on the variational parameters of a quantum circuit
rather than quantum states, which makes it difficult to understand the
mechanism of optimization process through the property of quantum states. Here,
we propose a quantum data visualization method using quantum kernels, which
enables us to offer fast and highly accurate visualization of quantum states.
In our numerical experiments, we visualize hand-written digits dataset and
apply -nearest neighbor algorithm to the low-dimensional data to
quantitatively evaluate our proposed method compared with a classical kernel
method. As a result, our proposed method achieves comparable accuracy to the
state-of-the-art classical kernel method, meaning that the proposed
visualization method based on quantum machine learning does not degrade the
separability of the input higher dimensional data. Furthermore, we visualize
the optimization trajectories of finding the ground states of transverse field
Ising model and successfully find the trajectory characteristics. Since quantum
states are higher dimensional objects that can only be seen via observables,
our visualization method, which inherits the similarity of quantum data, would
be useful in understanding the behavior of quantum circuits and algorithms.Comment: 10pages, 8 figures, 2 table
A case of Cowden syndrome with a novel mutation in the PTEN gene
Cowden syndrome (CS) is an autosomal dominant inherited disorder characterized by macrocephaly and multiple hamartomas. The responsible gene is PTEN (phosphate and tensin homolog detected on chromosome 10), which negatively regulates cell proliferation and survival. We herein present a 46-year-old woman with the typical clinical features of CS. A DNA sequencing analysis of the coding regions and flanking introns of the PTEN gene revealed a novel heterozygous mutation (c.403A > G, p.Ile135Val) in exon 5 that had not been previously reported in CS. J. Med. Invest
Sterile Abscess in the Myocardium after Direct Intramyocardial Injection Related to Gene Therapy in a Swine Model
Cardiac gene therapy is one of the most promising approaches to cure patients with cardiac dysfunctions. Many ways of efficient gene transfer using viral vectors are tested, and some of them are already used in clinical settings. However, it is always important to be keenly alert to the possible complications when a new therapy is introduced. We present a case of myocardial sterile abscess in a swine model associated with a direct myocardial injection
Multimodality Imaging of Chronic Ischemia
Although ischemic cardiomyopathy is commonly caused by chronic obstructive coronary disease, the mechanism of the cause is still under investigation. We present echocardiographic strain, magnetic resonance, and histology findings in a chronic ischemia model in preclinical study. This case illustrates the features of multimodality imaging in chronic obstructive coronary disease and gives us great insight into understanding the mechanism of ischemic cardiomyopathy
Reversal of Cardiac Dysfunction After Long-Term Expression of SERCA2a by Gene Transfer in a Pre-Clinical Model of Heart Failure
ObjectivesThe aim of this study was to examine the effects of sarcoplasmic reticulum Ca2+ ATPase (SERCA2a) gene transfer in a swine heart failure (HF) model.BackgroundReduced expression and activity of SERCA2a have been documented in HF. Prior studies have reported the beneficial effects of short-term SERCA2a overexpression in rodent models. However, the effects of long-term expression of SERCA2a in pre-clinical large animal models are not known.MethodsYorkshire-Landrace pigs were used (n = 16) to create volume overload by percutaneously severing chordae tendinae of the mitral apparatus with a bioptome to induce mitral regurgitation. At 2 months, pigs underwent intracoronary delivery of either recombinant adeno-associated virus type 1 (rAAV1) carrying SERCA2a under a cytomegalovirus promoter (rAAV1.SERCA2a) (n = 10; group 1) or saline (n = 6; group 2).ResultsAt 2 months, study animals were found to be in a compensated state of volume-overload HF (increased left ventricular internal diastolic and systolic diameters [LVIDd and LVIDs]). At 4 months, gene transfer resulted in: 1) positive left ventricular (LV) inotropic effects (adjusted peak left ventricular pressure rate of rise (dP/dt)max/P, 21.2 ± 3.2 s−1 group 1 vs. 15.5 ± 3.0 s−1 group 2; p < 0.01); 2) improvement in LV remodeling (% change in LVIDs −3.0 ± 10% vs. +15 ± 11%, respectively; p < 0.01). At follow-up, brain natriuretic peptide levels remained stable in group 1 after gene transfer, in contrast to rising levels in group 2. Further, cardiac SERCA2a expression was significantly decreased in group 2 whereas in group 1 it was restored to normal levels. There was no histopathological evidence of acute myocardial inflammation or necrosis.ConclusionsUsing a large-animal, volume-overload model of HF, we report that long-term overexpression of SERCA2a by in vivo rAAV1-mediated intracoronary gene transfer preserved systolic function, potentially prevented diastolic dysfunction, and improved ventricular remodeling
Sub-millimeter Observations of Giant Molecular Clouds in the Large Magellanic Cloud: Temperature and Density as Determined from J=3-2 and J=1-0 transitions of CO
We have carried out sub-mm 12CO(J=3-2) observations of 6 giant molecular
clouds (GMCs) in the Large Magellanic Cloud (LMC) with the ASTE 10m sub-mm
telescope at a spatial resolution of 5 pc and very high sensitivity. We have
identified 32 molecular clumps in the GMCs and revealed significant details of
the warm and dense molecular gas with n(H2) 10 cm and
Tkin 60 K. These data are combined with 12CO(J=1-0) and 13CO(J=1-0)
results and compared with LVG calculations. We found that the ratio of
12CO(J=3-2) to 12CO(J=1-0) emission is sensitive to and is well correlated with
the local Halpha flux. We interpret that differences of clump propeties
represent an evolutionary sequence of GMCs in terms of density increase leading
to star formation.Type I and II GMCs (starless GMCs and GMCs with HII regions
only, respectively) are at the young phase of star formation where density does
not yet become high enough to show active star formation and Type III GMCs
(GMCs with HII regions and young star clusters) represents the later phase
where the average density is increased and the GMCs are forming massive stars.
The high kinetic temperature correlated with \Halpha flux suggests that FUV
heating is dominant in the molecular gas of the LMC.Comment: 74 pages, including 41 figures, accepted for publication in ApJ
X-ray harmonic comb from relativistic electron spikes
X-ray devices are far superior to optical ones for providing nanometre
spatial and attosecond temporal resolutions. Such resolution is indispensable
in biology, medicine, physics, material sciences, and their applications. A
bright ultrafast coherent X-ray source is highly desirable, for example, for
the diffractive imaging of individual large molecules, viruses, or cells. Here
we demonstrate experimentally a new compact X-ray source involving high-order
harmonics produced by a relativistic-irradiance femtosecond laser in a gas
target. In our first implementation using a 9 Terawatt laser, coherent soft
X-rays are emitted with a comb-like spectrum reaching the 'water window' range.
The generation mechanism is robust being based on phenomena inherent in
relativistic laser plasmas: self-focusing, nonlinear wave generation
accompanied by electron density singularities, and collective radiation by a
compact electric charge. The formation of singularities (electron density
spikes) is described by the elegant mathematical catastrophe theory, which
explains sudden changes in various complex systems, from physics to social
sciences. The new X-ray source has advantageous scalings, as the maximum
harmonic order is proportional to the cube of the laser amplitude enhanced by
relativistic self-focusing in plasma. This allows straightforward extension of
the coherent X-ray generation to the keV and tens of keV spectral regions. The
implemented X-ray source is remarkably easily accessible: the requirements for
the laser can be met in a university-scale laboratory, the gas jet is a
replenishable debris-free target, and the harmonics emanate directly from the
gas jet without additional devices. Our results open the way to a compact
coherent ultrashort brilliant X-ray source with single shot and high-repetition
rate capabilities, suitable for numerous applications and diagnostics in many
research fields
Multimodality imaging to identify lipid-rich coronary plaques and predict periprocedural myocardial injury: Association between near-infrared spectroscopy and coronary computed tomography angiography
BackgroundThis study compares the efficacy of coronary computed tomography angiography (CCTA) and near-infrared spectroscopy intravascular ultrasound (NIRS–IVUS) in patients with significant coronary stenosis for predicting periprocedural myocardial injury during percutaneous coronary intervention (PCI).MethodsWe prospectively enrolled 107 patients who underwent CCTA before PCI and performed NIRS–IVUS during PCI. Based on the maximal lipid core burden index for any 4-mm longitudinal segments (maxLCBI4mm) in the culprit lesion, we divided the patients into two groups: lipid-rich plaque (LRP) group (maxLCBI4mm ≥ 400; n = 48) and no-LRP group (maxLCBI4mm < 400; n = 59). Periprocedural myocardial injury was a postprocedural cardiac troponin T (cTnT) elevation of ≥5 times the upper limit of normal.ResultsThe LRP group had a significantly higher cTnT (p = 0.026), lower CT density (p < 0.001), larger percentage atheroma volume (PAV) by NIRS–IVUS (p = 0.036), and larger remodeling index measured by both CCTA (p = 0.020) and NIRS–IVUS (p < 0.001). A significant negative linear correlation was found between maxLCBI4mm and CT density (rho = −0.552, p < 0.001). Multivariable logistic regression analysis identified maxLCBI4mm [odds ratio (OR): 1.006, p = 0.003] and PAV (OR: 1.125, p = 0.014) as independent predictors of periprocedural myocardial injury, while CT density was not an independent predictor (OR: 0.991, p = 0.22).ConclusionCCTA and NIRS–IVUS correlated well to identify LRP in culprit lesions. However, NIRS–IVUS was more competent in predicting the risk of periprocedural myocardial injury
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