Abstract
We present a flip-flop dual-component model to treat quantum dynamics of relativistic particles with a rest mass and investigate the matter waves’ phase and amplitude modulations due to ...Heisenberg’s uncertainty principle. Their matter waves behave like a traveling Gaussian-shaped wave packet accompanied by a guiding pilot wave, and the phase modulations result in mass oscillations. These effects are more prominent for light-weighted elementary particles, such as neutrinos and electrons. This mechanism is solely due to the uncertainty principle and has nothing to do with the flavor-mixing of neutrinos. Simulations using neutrinos and electrons are presented, which indicate an oscillation period on the order of ps. This study primarily focuses on the predicted mass oscillations induced by the uncertainty principle. A slit-type interference experiment using neutrinos and electrons from reactors is proposed to test the predicted behaviors.
Aberrant DNA hypermethylation contributes to myelomagenesis by silencing tumor-suppressor genes. Recently, a few reports have suggested that a novel class of small non-coding RNAs, called ...Piwi-interacting RNAs (piRNAs), may be involved in the epigenetic regulation of cancer. In this study, for the first time we provided evidence that the expression of piRNA-823 was upregulated in multiple myeloma (MM) patients and cell lines, and positively correlated with clinical stage. Silencing piRNA-823 in MM cells induced deregulation of cell cycle regulators and apoptosis-related proteins expression, accompanied by inhibition of tumorigenicity in vitro and in vivo. Moreover, piRNA-823 was directly relevant to de novo DNA methyltransferases, DNMT3A and 3B, in primary CD138(+) MM cells. The inhibited expression of piRNA-823 in MM cells resulted in marked reduction of DNMT3A and 3B at both mRNA and protein levels, which in turn led to decrease in global DNA methylation and reexpression of methylation-silenced tumor suppressor, p16(INK4A). In addition, piRNA-823 abrogation in MM cells induced reduction of vascular endothelial growth factor secretion, with consequent decreased proangiogenic activity. Altogether, these data support an oncogenic role of piRNA-823 in the biology of MM, providing a rational for the development of piRNA-targeted therapeutic strategies in MM.
The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray ...observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 10^{5} and 10^{9} GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.
The corrosion behavior of pure titanium was investigated in 0.05 M H sub(2)SO sub(4) solution with fluoride ions using various electrochemical techniques, such as open circuit potential (OCP), ...potentiodynamic polarization, electrochemical impedance measurements (EIS) and surface analyses via X-ray photoelectron spectroscopy (XPS). The results showed that titanium exhibited spontaneous passivation behavior in solutions with 0 M and 0.0005 M fluoride ions, compared with the active-passive behavior with 0.002 M similar to 0.005 M. A critical value of the fluoride concentration was defined between 0.0005 M and 0.002 M. Multiple corrosion potentials were found under the conditions with fluoride ions higher than 0.002 M. The fluoride ion accelerated the corrosion of titanium via changing the structure of the film formed at OCP and destroying the protectiveness of the film, while it had few effects on cathodic hydrogen evolution reaction and passivation process at OCP. A corrosion mechanism associated with the fluoride ion was proposed. The corrosion behavior was well interpreted using the proposed mechanism and a criteria for the critical value of the fluoride concentration was also proposed.
1. Prolactin (PRL) as a polypeptide hormone which plays a crucial role in egg production traits.
2. Polymorphisms of the PRL gene were analysed with DNA sequencing and polymerase chain ...reaction-single-strand conformation polymorphism methods in two Chinese domestic laying duck breeds (Jinding, n = 400, Youxian, n = 400, respectively).
3. The results showed that one polymorphism was detected (A-412G) in intron 1 of the PRL gene, with three genotypes: AA, AG and GG. Association analysis showed that the ducks with the GG genotype had significantly greater egg production and egg weight than those with AG and AA genotype (p < 0.05). Hence, the 412A > G polymorphism of the PRL gene in intron 1 is a potentially valuable genetic marker for laying duck breeding programmes.
Recently, the LHAASO Collaboration published the detection of 12 ultrahigh-energy γ-ray sources above 100 TeV, with the highest energy photon reaching 1.4 PeV. The first detection of PeV γ rays from ...astrophysical sources may provide a very sensitive probe of the effect of the Lorentz invariance violation (LIV), which results in decay of high-energy γ rays in the superluminal scenario and hence a sharp cutoff of the energy spectrum. Two highest energy sources are studied in this work. No signature of the existence of the LIV is found in their energy spectra, and the lower limits on the LIV energy scale are derived. Our results show that the first-order LIV energy scale should be higher than about 10^{5} times the Planck scale M_{Pl} and that the second-order LIV scale is >10^{-3}M_{Pl}. Both limits improve by at least one order of magnitude the previous results.
As a mechanism compensating for obstructive coronary artery disease, coronary collateral circulation (CCC) has attracted cardiologists for a long time to explore its potential impact. In the present ...study, Chinese patients suffering from ≥95% coronary stenosis, as diagnosed by angiography, have been investigated for the correlation between CCC and lipoprotein(a) Lp(a) levels. A cohort of 654 patients was divided into four categories according to Rentrop grades 0, 1, 2, and 3. Lp(a) levels were divided into model 1, discretized with critical values of 33 and 66%, and model 2, discretized with a cutoff value of 30.0 mg/dL. Furthermore, we evaluated the correlation between CCC and serum Lp(a) levels. The four groups had significantly different Lp(a) levels (25.80±24.72, 18.99±17.83, 15.39±15.80, and 8.40±7.75 mg/dL; P<0.001). In model 1, concerning R0, the risk in the third Lp (a) tertile (OR=3.34, 95%CI=2.32-4.83) was greater than that in the first tertile. In model 2, concerning R0, the risk in Lp(a) >30.0 group (OR=6.77, 95%CI=4.44-10.4) was greater than that of Lp(a) <30.0 mg/dL. The worst condition of CCC can be predicted independently by Lp(a) levels. In addition to clinical usage, Lp(a) levels can also be utilized as biological markers.
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