A novel flavonol glycoside named caohuoside-B was isolated from the aerial parts of
Epimedium koreanum, along with a known flavonol glycoside, epimedokoreanoside-I. Their structures were established ...by spectroscopic methods. The new compound was elucidated as anhydroicaritin
3-O-β-
d-(4,6-O-
diacetyl)
glucopyranosyl-(1 → 3)α-
l
-(4″-O-
acetylrhamnopyranoside)-7-O-β-
d-glucopyranoside
.
The Large High Altitude Air Shower Observatory (LHAASO) has three sub-arrays, KM2A, WCDA and WFCTA. The flux variations of cosmic ray air showers were studied by analyzing the KM2A data during the ...thunderstorm on 10 June 2021. The number of shower events that meet the trigger conditions increases significantly in atmospheric electric fields, with maximum fractional increase of 20%. The variations of trigger rates (increases or decreases) are found to be strongly dependent on the primary zenith angle. The flux of secondary particles increases significantly, following a similar trend with that of the shower events. To better understand the observed behavior, Monte Carlo simulations are performed with CORSIKA and G4KM2A (a code based on GEANT4). We find that the experimental data (in saturated negative fields) are in good agreement with simulations, assuming the presence of a uniform upward electric field of 700 V/cm with a thickness of 1500 m in the atmosphere above the observation level. Due to the acceleration/deceleration and deflection by the atmospheric electric field, the number of secondary particles with energy above the detector threshold is modified, resulting in the changes in shower detection rate.
For decades, supernova remnants (SNRs) have been considered the prime sources of Galactic Cosmic rays (CRs). But whether SNRs can accelerate CR protons to PeV energies and thus dominate CR flux up to ...the knee is currently under intensive theoretical and phenomenological debate. The direct test of the ability of SNRs to operate as CR PeVatrons can be provided by ultrahigh-energy (UHE; \(E_\gamma \geq 100\)~TeV) \(\gamma\)-rays. In this context, the historical SNR Cassiopeia A (Cas A) is considered one of the most promising target for UHE observations. This paper presents the observation of Cas A and its vicinity by the LHAASO KM2A detector. The exceptional sensitivity of LHAASO KM2A in the UHE band, combined with the young age of Cas A, enabled us to derive stringent model-independent limits on the energy budget of UHE protons and nuclei accelerated by Cas A at any epoch after the explosion. The results challenge the prevailing paradigm that Cas A-type SNRs are major suppliers of PeV CRs in the Milky Way.
The first epidemic of dengue in China associated with significant severe and fatal hemorrhagic disease which met the World Health Organization case definition occurred on Hainan Island in 1985-1986. ...The epidemic began in Zhan County in September 1985, spread throughout the coastal areas, and ultimately involved 13 counties and cities of the island in 1986. The mosquito vector was Aedes aegypti. The morbidity associated with dengue infection on Hainan Island was 1,913 per 100,000 residents, with a case fatality rate of 0.25%. Severe disease was more prevalent in the 10-29-year-old age group. Principal clinical features in laboratory-confirmed cases were fever, osteoarthralgia, hemorrhage and/or shock, and thrombocytopenia. Complications such as acute intravascular hemolysis, diffuse intravascular coagulation, hemoconcentration, pleural effusion, altered mentality, and pneumonia were also observed. One hundred twenty-five isolates of dengue 2 virus were recovered from acute-phase serum samples from 278 patients, and 5 strains of this same virus serotype were isolated from 5 pools of adult Ae. aegypti.
The KM2A is the largest sub-array of the Large High Altitude Air Shower Observatory (LHAASO). It consists of 5216 electromagnetic particle detectors (EDs) and 1188 muon detectors (MDs). The data ...recorded by the EDs and MDs are used to reconstruct primary information of cosmic ray and gamma-ray showers. This information is used for physical analysis in gamma-ray astronomy and cosmic ray physics. To ensure the reliability of the LHAASO-KM2A data, a three-level quality control system has been established. It is used to monitor the status of detector units, stability of reconstructed parameters and the performance of the array based on observations of the Crab Nebula and Moon shadow. This paper will introduce the control system and its application on the LHAASO-KM2A data collected from August 2021 to July 2023. During this period, the pointing and angular resolution of the array were stable. From the observations of the Moon shadow and Crab Nebula, the results achieved using the two methods are consistent with each other. According to the observation of the Crab Nebula at energies from 25 TeV to 100 TeV, the time averaged pointing errors are estimated to be \(-0.003^{\circ} \pm 0.005^{\circ}\) and \(0.001^{\circ} \pm 0.006^{\circ}\) in the R.A. and Dec directions, respectively.
The diffuse Galactic \(\gamma\)-ray emission, mainly produced via interactions between cosmic rays and the interstellar medium and/or radiation field, is a very important probe of the distribution, ...propagation, and interaction of cosmic rays in the Milky Way. In this work we report the measurements of diffuse \(\gamma\)-rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner (\(15^{\circ}<l<125^{\circ}\), \(|b|<5^{\circ}\)) and outer (\(125^{\circ}<l<235^{\circ}\), \(|b|<5^{\circ}\)) Galactic plane are detected with \(29.1\sigma\) and \(12.7\sigma\) significance, respectively. The outer Galactic plane diffuse emission is detected for the first time in the very- to ultra-high-energy domain (\(E>10\)~TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of \(-2.99\pm0.04\), which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of \(\sim3\) than the prediction. A similar spectrum with an index of \(-2.99\pm0.07\) is found in the outer Galaxy region, and the absolute flux for \(10\lesssim E\lesssim60\) TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show clear deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations.
AIM: To investigate the expression of NGF family and their receptors in gastric carcinoma and normal gastric mucosa,and to elucidate their effects on gastdc carcinoma.METHODS: RNA of gastric cancer ...tissues and normal gastric tissues was respectively isolated and mRNA was purified.Probes of both mRNA reverse transcription product cDNAs labled with α-^33p dATP were respectively hybridized with Atlas Array membrane where NGF and their family genes were spotted on. Hybridized signal images were scanned on phosphor screen with ImageQuant 5.1 software after hybridization. Normalized values on spots were analyzed with ArrayVersion 5.0 software. Differential expression of NGF family and their receptors mRNA was confirmed between hybridized Atlas Array membranes of gastric cancer tissues and normal gastric mucosa, then their effects on gastric carcinoma were investigated.RESULTS: Hybridization signal images on Atlas Array membrane appeared in a lower level of nonspecific hybridization. Both of NGF family and their receptors Trk family mRNA were expressed in gastric cancer and normal gastric mucosa. But adversely up-regulated expression in other tissues and organs. NGF, BDGF, NT-3, NT-4/5, NT-6 and TrkA, B and C were down-regulated simultaneously in gastric carcinoma in comparison with normal gastric mucosa. Degrees of down-regulation in NGF family were greater than those in their receptors Trk family. Down-regulation of NT-3 and BDGF was the most significant,and TrkC down-regulation level was the lowest in receptors Trk family. CONCLUSION:Down-regulated expression of NGF family and their receptors Trk family mRNA in gastric cancer is confirned.NGF family and their receptors Trk family probadly play a unique role in gastric cancer cell apoptosis by a novel Ras or Raf signal transduction pathway.Their synchronous effects are closely assoclated with occurrence and development of gastric carcinoma induced by reduction of signal transduction of programmed cell death.
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