A
bstract
The higher-order quantum electrodynamics (QED) effect for vacuum pair production has been searched without success since 1954. In this paper, we show that the combined world-wide data of ...lepton pair vacuum production is about 20% smaller than the latest lowest order QED calculation with a 5.2 sigma-level of significance and is consistent with the corresponding higher-order QED result. We claim the discovery of higher-order effect for the QED pair production, which settles the dust of previous debates for several decades. The verification of higher-order QED effect is a fundamental scientific problem, which is an important milestone towards the nonperturbative and nonlinear regime of QED vacuum.
Ultra-relativistic heavy-ion collisions are expected to produce the strongest electromagnetic fields in the known Universe. These highly-Lorentz contracted fields can manifest themselves as linearly ...polarized quasi-real photons that can interact via the Breit-Wheeler process to produce lepton anti-lepton pairs. The energy and momentum distribution of the produced dileptons carry information about the strength and spatial distribution of the colliding fields. Recently it has been demonstrated that photons from these fields can interact even in heavy-ion collisions with hadronic overlap, providing a purely electromagnetic probe of the produced medium. In this review we discuss the recent theoretical progress and experimental advances for mapping the ultra-strong electromagnetic fields produced in heavy-ion collisions via measurement of the Breit-Wheeler process.
Full text
Available for:
DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Recently, significant enhancements of e+e− pair production at very low transverse momentum (pT<0.15 GeV/c) were observed by the STAR collaboration in peripheral hadronic A+A collisions. This excesses ...can not be described by the QGP thermal radiation and ρ in-medium broadening calculations. This is a sign of coherent photon–photon interactions, which were conventionally studied only in ultra-peripheral collisions. In this article, we present calculations of lepton pair (e+e− and μ+μ−) production from coherent photon–photon interactions in hadronic A+A collisions at RHIC and LHC energies within the STAR and ALICE acceptance.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Recently, significant enhancements of J/ψ and e+e− pair production at very low transverse momenta were observed by the STAR and ALICE collaborations in peripheral hadronic A + A collisions. The ...anomalous excesses point to evidence of coherent photon–nucleus and photon–photon interactions in violent hadronic heavy-ion collisions, which were conventionally studied only in ultra-peripheral collisions. The isobaric collisions performed at RHIC provides a unique opportunity to test the existence of coherent photon products in hadronic heavy-ion collisions. The idea is that the possible production of coherent photon products is significantly different in different collision systems due to the variations in their charge and nuclear density distributions. In this letter, we focus on the peripheral collisions and provide theoretical predictions for coherent production of J/ψ and dielectron in isobaric collisions. We show that the expected yields differ significantly to perform the experimental test.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
To explore the role of microRNA-217 in non-small cell lung cancer (NSCLC) and its underlying mechanism.
MicroRNA-217 expression in 48 NSCLC tissues and paracancerous tissues were detected by qRT-PCR ...(quantitative Real-time polymerase chain reaction). The relationship between microRNA-217 expression and prognosis of NSCLC patients was analyzed. Target gene of microRNA-217 was predicted by bioinformatics method and further verified by luciferase reporter gene assay. Cell proliferation, cell cycle and apoptosis were detected after altering microRNA-217 expression in NSCLC cells. The effect of microRNA-217 on regulating PI3K pathway was detected by Western blot.
MicroRNA-217 was downregulated in NSCLC tissues than that of paracancerous tissues. Shorter overall survival (OS) was observed in NSCLC patients with lower expression of microRNA-217 than those with higher expression. Overexpressed microRNA-217 remarkably inhibited proliferation and cell cycle, whereas induced apoptosis of NSCLC cells. AKT3 was screened out to be the target gene of microRNA-217. Western blot results demonstrated that microRNA-217 upregulated AKT3 and PI3K pathway-related genes.
Downregulated microRNA-217 promotes the occurrence and progression of NSCLC through upregulating AKT3 via PI3K pathway.
Summary
To elucidate the association of coffee and bone health would help fracture risk reduction via dietary intervention. Although those who had higher coffee consumption were less likely to have ...osteoporosis, the associations between coffee consumption and fracture risk need further investigations with better study designs.
Introduction
The associations between coffee consumption and the risk of osteoporosis and fracture remain inconclusive. We aimed to better quantify these associations by conducting meta-analyses of observational studies.
Methods
Relevant studies were systematically searched on PubMed, Web of Science, Cochrane library, and Embase Database up to November 25, 2021. The odds ratio (OR) or relative risk (RR) with 95% confidence intervals (CI) was pooled and a dose–response analysis was performed.
Results
Four studies with 7114 participants for osteoporosis and thirteen studies with 391,956 participants for fracture incidence were included in the meta-analyses. High versus low coffee consumption was associated with a lower risk of osteoporosis pooled OR (95% CI): 0.79 (0.65–0.92), while it was non-significantly associated with fracture incidence pooled OR (95% CI): 0.86 (0.67–1.05) at hip and 0.89 (0.42–1.36) at non-hip. A non-linear association between the level of coffee consumption and hip fracture incidence was shown (
P
= 0.004). The pooled RR (95% CI) of hip fracture risk in those who consumed 1, 2–3, 4, and ≥ 9 cups of coffee per day was 0.92 (0.87–0.97), 0.89 (0.83–0.95), 0.91 (0.85–0.98), and 1.10 (0.76–1.59), respectively. The significance in the association between coffee consumption and the hip fracture incidence decreased in those studies that had larger sample size, higher quality, and more adjustments.
Conclusions
A dose-dependent relationship may exist between coffee consumption and hip fracture incidence. The effect of high versus low coffee consumption was influenced by study designs. Further studies with dedicated designs are needed to confirm the independent effects of coffee consumption on bone health.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Background
There is limited information involving population data about the role of maternal health, fetal growth and neonatal health on children's developmental status at ages 4–7 years. Our aim was ...to determine the contribution of maternal, fetal and neonatal health to developmental status at ages 4–7 years.
Methods
In this 7‐year follow‐up prospective cohort study, a sample of 26 803 mothers participated in the beginning. Among their children, 19 187 voluntarily completed the development screening test or the social life ability survey, which were designed for two different age groups (<6 or ≥6 years old, respectively). Logistic regression analysis was used to link the data with the prenatal outcome card and interview questionnaire applied to pregnant women in previous study, to the analysis of various related factors such as demographic, socio‐economic, disease and menstrual history, marriage and pregnancy care.
Result
Univariate and multivariate logistic regression analysis were used separately in two age groups 4–6 (n = 8439) and 6–7 (n = 10 748) years old to analyse relative factors. Maternal age of 25–30 years, maternal education of high school and greater, family income and not drinking during pregnancy were associated with higher scores in development.
Conclusion
Both preconception and pregnancy health education and health care are the important maternal factors closely associated with children's cognitive and social competence. Public health policies for preconception care and public welfare for high‐quality childcare are essential for improving children's life.
Full text
Available for:
BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
The brown planthopper, Nilaparvata lugens, is a serious pest threatening rice production across the world. To identify the main features of the gene expression and the key components of the midgut of ...N. lugens responsible for nutrition, xenobiotic metabolism and the immune response, we used pyrosequencing to sample the transcriptome. More than 190 000 clean sequences were generated, which led to about 30 000 unique sequences. Sequence analysis indicated that genes with abundant transcripts in the midgut of N. lugens were mainly sugar hydrolyases and transporters, proteases and detoxification‐related proteins. Based on the sequence information, we cloned the candidate sucrase gene; this enzyme is likely to interact with the perimicrovillar membrane through its highly hydrophobic C‐terminal region. Many proteases were identified, which supported the hypothesis that N. lugens uses the proteolysis system for digestion. Scores of detoxification genes were newly identified, including cytochrome P450s, glutathione S‐transferases, caroxylesterases. A wealth of new transcripts possibly participating in the immune response were described as well. The gene encoding a peptidoglycan recognition protein was cloned. Unlike in Acyrthosiphon pisum, the immunodeficiency pathway may be present in N. lugens. This is the first global analysis of midgut transcriptome from N. lugens.
Full text
Available for:
BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
An afterpulse occurs within a short time after the main pulse and cannot be directly distinguished from the true physical signals. In cosmic ray experiments, a large number of photomultiplier tubes ...(PMTs) are used, which means the occurrence of afterpulses leads to a significant background. Therefore, before PMTs are employed, their afterpulse characteristics need to be evaluated to make sure they perform as expected. To evaluate the impact of afterpulses, we investigate the afterpulses for the Hamamatsu PMT R5912 (a candidate of the WCDA and MD for LHAASO) using two different electronic testing systems. First, we measured the characteristics of afterpulses in detail using a frequency-tunable flash analog-to-digital converter (ADC) with a time window of up to 15 mu s after a laser signal. We measured the time delay with respect to the main pulse, the amplitude, and the rate of the afterpulse dependence, on the main signal amplitude and the applied high voltage. Second, we developed a system that uses a multi-hit time-to-digital converter (multi-hit TDC), which allows for much faster measurement of the afterpulse rates, in order to make it possible to test up to 5000 large-sized PMTs.
PDF
