119 research outputs found
Effect of glucose and pyruvate on nuclear and cytoplasmic maturation of porcine oocytes in a chemically defined medium
The objective was to examine potential roles of glucose and pyruvate in nuclear and cytoplasmic maturation of porcine oocytes. Oocyte-cumulus complexes (OCC), derived from 3 to 6 mm follicles, were cultured in a chemically defined medium (pyruvate-free mNCSU37-PVA), with or without 5.55 mM glucose, during in vitro maturation (IVM); in the absence of glucose, germinal vesicle breakdown (GVBD) and nuclear maturation were prevented (P < 0.05). Subsequently, OCC were cultured for IVM in glucose-containing mNCSU37-PVA supplemented with 6-amononicotinamide (6-AN) and diphenyleneiodonium (DPI), inhibitors of the pentose phosphate pathway (PPP); both compounds (>= 10 mu M 6-AN and >= 10 nM DPI) inhibited resumption of meiosis (P < 0.05). Supplementation of glucose-free maturation medium with increasing concentrations of pyruvate induced resumption of meiosis and increased the incidence of oocytes reaching metaphase-II in a concentration-dependent manner (P < 0.05). More mature oocytes were obtained in the presence of pyruvate + glucose (P < 0.05). After culture to allow maturation, glutathione content was higher in oocytes cultured in the presence of pyruvate alone than in those cultured in glucose alone; inclusion of 6-AN abolished responses to pyruvate (P < 0.05). In conclusion, both glucose and pyruvate played a critical role in the release of porcine oocytes from arrest at the GV-I stage, probably through the PPP, whereas supplementation with pyruvate improved cytoplasmic maturation, as determined by oocyte glutathione content.</p
Two-level Quantum Walkers on Directed Graphs II: An Application to qRAM
This is the second paper in a series of two. Using a multi-particle
continuous-time quantum walk with two internal states, which has been
formulated in the first paper (arXiv:2112.08119), we physically implement a
quantum random access memory (qRAM). Data with address information are
dual-rail encoded into quantum walkers. The walkers pass through perfect binary
trees to access the designated memory cells and copy the data stored in the
cells. A roundabout gate allocated at each node serves as a router to move the
walker from the parent node to one of two child nodes, depending on the
internal state of the walker. In this process, the address information is
sequentially encoded into the internal states so that the walkers are
adequately delivered to the target cells. The present qRAM, which processes
-qubit data, is implemented in a quantum circuit of depth
and requires qubit resources. This is more efficient
than the conventional bucket-brigade qRAM that requires steps and
qubit resources for processing. Moreover, since the walkers are
not entangled with any device on the binary trees, the cost of maintaining
coherence could be reduced. Notably, by simply passing quantum walkers through
binary trees, data can be automatically extracted in a quantum superposition
state. In other words, any time-dependent control is not required.Comment: 23 pages. This is the second paper in a series of two. The first
paper is arXiv:2112.0811
Two-level Quantum Walkers on Directed Graphs I: Universal Quantum Computing
We propose a universal quantum computation via a fermionic/bosonic
multi-particle continuous-time quantum walk with two internal states. A
dual-rail encoding is adopted to convert the information: a single-qubit is
represented by the presence of a single quantum walker in either of the two
parallel paths. We develop a roundabout-like gate that moves a walker from one
path to the other, either clockwise or counterclockwise, depending on its
internal state. The roundabout gate can be concretely realized by a
single-particle scattering on a directed weighted graph with the edge weights
and . The universal gates are constructed by appropriately combining
two-particle scatterings on straight paths, several roundabout gates, and some
unitary gates that act on the internal states of quantum walkers. Any ancilla
qubit is not required in our model, and hence the architecture can be
simplified. The computation is done by just passing quantum walkers through
properly designed paths. Namely, there is no need for any time-dependent
control. The implementation of quantum memory is also presented.Comment: 20 pages, 16 figure
Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae
We systematically surveyed period variations of superhumps in SU UMa-type
dwarf novae based on newly obtained data and past publications. In many
systems, the evolution of superhump period are found to be composed of three
distinct stages: early evolutionary stage with a longer superhump period,
middle stage with systematically varying periods, final stage with a shorter,
stable superhump period. During the middle stage, many systems with superhump
periods less than 0.08 d show positive period derivatives. Contrary to the
earlier claim, we found no clear evidence for variation of period derivatives
between superoutburst of the same object. We present an interpretation that the
lengthening of the superhump period is a result of outward propagation of the
eccentricity wave and is limited by the radius near the tidal truncation. We
interpret that late stage superhumps are rejuvenized excitation of 3:1
resonance when the superhumps in the outer disk is effectively quenched. Many
of WZ Sge-type dwarf novae showed long-enduring superhumps during the
post-superoutburst stage having periods longer than those during the main
superoutburst. The period derivatives in WZ Sge-type dwarf novae are found to
be strongly correlated with the fractional superhump excess, or consequently,
mass ratio. WZ Sge-type dwarf novae with a long-lasting rebrightening or with
multiple rebrightenings tend to have smaller period derivatives and are
excellent candidate for the systems around or after the period minimum of
evolution of cataclysmic variables (abridged).Comment: 239 pages, 225 figures, PASJ accepte
Drug retention rates and relevant risk factors for drug discontinuation due to adverse events in rheumatoid arthritis patients receiving anticytokine therapy with different target molecules
Objective: To compare reasons for discontinuation and drug retention rates per reason among anticytokine therapies, infliximab, etanercept and tocilizumab, and the risk of discontinuation of biological agents due to adverse events (AE) in patients with rheumatoid arthritis (RA). Method: This prospective cohort study included Japanese RA patients who started infliximab (n=412, 636.0 patientyears (PY)), etanercept (n=442, 765.3 PY), or tocilizumab (n=168, 206.5 PY) as the first biological therapy after their enrolment in the Registry of Japanese Rheumatoid Arthritis Patients for Long-term Safety (REAL) database. Drug retention rates were calculated using the Kaplan-Meier method. To compare risks of drug discontinuation due to AE for patients treated with these biological agents, the Cox proportional hazard model was applied. Results: The authors found significant differences among the three therapeutic groups in demography, clinical status, comorbidities and usage of concomitant drugs. Development of AE was the most frequent reason for discontinuation of biological agents in the etanercept and tocilizumab groups, and the second most frequent reason in the infliximab group. Discontinuation due to good control was observed most frequently in the infliximab group. Compared with etanercept, the use of infliximab (HR 1.69; 95% CI 1.14 to 2.51) and tocilizumab (HR 1.98; 95% CI 1.04 to 3.76) was significantly associated with a higher risk of discontinuation of biological agents due to AE. Conclusions: Reasons for discontinuation are significantly different among biological agents. The use of infliximab and tocilizumab was significantly associated with treatment discontinuation due to AE compared with etanercept
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