848 research outputs found
UV-finite scalar field theory with unitarity
In this paper we show how to define the UV completion of a scalar field
theory such that it is both UV-finite and perturbatively unitary. In the UV
completed theory, the propagator is an infinite sum of ordinary propagators. To
eliminate the UV divergences, we choose the coefficients and masses in the
propagator to satisfy certain algebraic relations, and define the infinite sums
involved in Feynman diagram calculation by analytic continuation. Unitarity can
be proved relatively easily by Cutkosky's rules. The theory is equivalent to
infinitely many particles with specific masses and interactions. We take the
theory as an example and demonstrate our idea through explicit Feynman
diagram computation.Comment: 14 pages, references adde
Three-body molecules - understanding the nature of , , and
The nature of the three pentaquark states, , and
, discovered by the LHCb Collaboration in 2019, is still under
debate, although the molecular interpretation
seems to be the most popular. In this work, by adding a meson into
the pair, we investigate the mass and decay width of
the three-body molecules and explore the
correlation between the existence of the
molecules with the existence of and
two-body molecules. The latter can be identified with
the doubly charmed tetraquark state recently discovered by the LHCb
Collaboration. Based on the molecular nature of , ,
, and , our results indicate that there exist two
three-body bound states of with
and , and binding energies
MeV and MeV below the mass threshold.
In addition, we find that the mass splitting of these two three-body molecules
are correlated to the mass splitting of and , which
offers a non-trivial way to reveal the molecular nature of these states. The
partial widths of two molecules decaying into
and are found to be several MeV.
We recommend the experimental searches for the
molecules in the and
invariant mass distributions
Automatic Blastomere Recognition from a Single Embryo Image
The number of blastomeres of human day 3 embryos is one of the most important criteria for evaluating embryo viability. However, due to the transparency and overlap of blastomeres, it is a challenge to recognize blastomeres automatically using a single embryo image. This study proposes an approach based on least square curve fitting (LSCF) for automatic blastomere recognition from a single image. First, combining edge detection, deletion of multiple connected points, and dilation and erosion, an effective preprocessing method was designed to obtain part of blastomere edges that were singly connected. Next, an automatic recognition method for blastomeres was proposed using least square circle fitting. This algorithm was tested on 381 embryo microscopic images obtained from the eight-cell period, and the results were compared with those provided by experts. Embryos were recognized with a 0 error rate occupancy of 21.59%, and the ratio of embryos in which the false recognition number was less than or equal to 2 was 83.16%. This experiment demonstrated that our method could efficiently and rapidly recognize the number of blastomeres from a single embryo image without the need to reconstruct the three-dimensional model of the blastomeres first; this method is simple and efficient
The neural correlates of value hierarchies: a prospective typology based on personal value profiles of emerging adults
IntroductionValue hierarchies, as motivational goals anchored in the self-schema, may be correlated with spontaneous activity in the resting brain, especially those involving self-relevance. This study aims to investigate the neural correlates of value hierarchies from the perspective of typology.MethodsA total of 610 Chinese college students (30.31% women), aged 18 to 23, completed the personal values questionnaire and underwent resting-state functional magnetic resonance imaging.ResultsThe latent profile analysis revealed three personal value profiles: traditional social orientation, modernized orientation, and undifferentiated orientation. Neuroimaging results revealed that individuals with modernized orientation prioritized openness to change value, and this personal-focus is related to the higher low-frequency amplitude of the posterior insula; individuals with traditional social orientation prioritized self-transcendence and conservation values, and this social-focus is related to the stronger functional connectivity of the middle insula with the inferior temporal gyrus, temporal gyrus, posterior occipital cortex, and basal ganglia, as well as weaker functional connections within the right middle insula.DiscussionTaken together, these findings potentially indicate the intra-generational differentiation of contemporary Chinese emerging adults’ value hierarchies. At the neural level, these are correlated with brain activities involved in processing self- and other-relevance
Acute Kidney Injury Biomarkers for Patients in a Coronary Care Unit: A Prospective Cohort Study
Background: Renal dysfunction is an established predictor of all-cause mortality in intensive care units. This study analyzed the outcomes of coronary care unit (CCU) patients and evaluated several biomarkers of acute kidney injury (AKI), including neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18) and cystatin C (CysC) on the first day of CCU admission. Methodology/Principal Findings: Serum and urinary samples collected from 150 patients in the coronary care unit of a tertiary care university hospital between September 2009 and August 2010 were tested for NGAL, IL-18 and CysC. Prospective demographic, clinical and laboratory data were evaluated as predictors of survival in this patient group. The most common cause of CCU admission was acute myocardial infarction (80%). According to Acute Kidney Injury Network criteria, 28.7 % (43/150) of CCU patients had AKI of varying severity. Cumulative survival rates at 6-month follow-up following hospital discharge differed significantly (p,0.05) between patients with AKI versus those without AKI. For predicting AKI, serum CysC displayed an excellent areas under the receiver operating characteristic curve (AUROC) (0.89560.031, p,0.001). The overall 180-day survival rate was 88.7 % (133/150). Multiple Cox logistic regression hazard analysis revealed that urinary NGAL, serum IL-18, Acute Physiology, Age and Chronic Health Evaluation II (APACHE II) and sodium on CCU admission day one were independent risk factors for 6-month mortality. In terms of 6-month mortality, urinary NGAL had the best discriminatory power, the best Youden index, and the highest overall correctness of prediction
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