Measurement of the Cosmic Ray Helium Energy Spectrum from 70 GeV to 80 TeV with the DAMPE Space Mission

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.

Measurement of the cosmic ray proton spectrum from 40 GeV to 100 TeV with the DAMPE satellite

The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 ¹/₂ years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

Mapping quantitative trait loci with additive effects and additive x additive epistatic interactions for biomass yield, grain yield, and straw yield using a doubled haploid population of wheat (Triticum aestivum L.)

Biomass yield is one of the most important traits for wheat (Triticum aestivum L.)-breeding programs. Increasing the yield of the aerial parts of wheat varieties will be an integral component of future wheat improvement; however, little is known regarding the genetic control of aerial part yield. A doubled haploid population, comprising 168 lines derived from a cross between two winter wheat cultivars, 'Huapei 3' (HP3) and 'Yumai 57' (YM57), was investigated. Quantitative trait loci (QTL) for total biomass yield, grain yield, and straw yield were determined for additive effects and additive x additive epistatic interactions using the QTLNetwork 2.0 software based on the mixed-linear model. Thirteen QTL were determined to have significant additive effects for the three yield traits, of which six also exhibited epistatic effects. Eleven significant additive x additive interactions were detected, of which seven occurred between QTL showing epistatic effects only, two occurred between QTL showing epistatic effects and additive effects, and two occurred between QTL with additive effects. These QTL explained 1.20 to 10.87% of the total phenotypic variation. The QTL with an allele originating from YM57 on chromosome 4B and another QTL contributed by HP3 alleles on chromosome 4D were simultaneously detected on the same or adjacent chromosome intervals for the three traits in two environments. Most of the repeatedly detected QTL across environments were not significant (P > 0.05). These results have implications for selection strategies in wheat biomass yield and for increasing the yield of the aerial part of wheat.

Immunodiagnostic value of combined detection of autoantibodies to tumor-associated antigens as biomarkers in pancreatic cancer

Previous studies demonstrated that cancer sera contain antibodies, which react with a unique group of autologous cellular antigens called tumour-associated antigens (TAAs). This study determines whether a panel of TAAs would enhance antibody detection and be a useful approach in pancreatic cancer (PC) detection and diagnosis. The panel of TAAs was composed of six TAAs including p53, p16, p62, survivin, Koc and IMP1 full-length recombinant proteins. Enzyme-linked immunosorbent assay (ELISA) was used to detect antibodies against these six TAAs in 23 sera from patients with PC and also 23 sera from normal individuals. Antibody frequency to any individual TAA in PC was variable and ranged from 14.7% to 30.4%. With the successive addition of TAAs to a final total of six antigens, there was a stepwise increase in positive antibody reactions reaching a sensitivity of 60.9% and a specificity of 87.0% in PC. Positive and negative likelihood ratio were 4.685 and 0.449, respectively. Positive and negative predictive values were, respectively, 82.4% and 69.0%. Agreement rate and Kappa value were 73.9% and 0.478, respectively. The data from this study support our previous hypothesis that using a panel of appropriately selected TAAs can enhance autoantibody detection in immunodiagnosis of PC. In 15 PC sera with carbohydrate antigen 19-9 (CA19-9) negative, 6 (40%) were found to have anti-TAA (anti-tumour associated antigens) antibodies. When CA19-9 and anti-TAAs were used together as markers in PC detection, the diagnostic sensitivity could be raised from 60.9% to 69.6%. Anti-TAA and CA19-9 were independent markers, and the simultaneous use of these two markers could raise the sensitivity of PC detection.

[Dynamic observation of serum magnesium level during treatment of patients with chronic cor pulmonale and respiratory failure]

Serum magnesium (Mg) levels in 48 patients (486 person-time) with chronic cor pulmonale and respiratory failure were observed dynamically during treatment. Results showed a tendency towards hypomagnesemia in patients with acute exacerbation and in the early stage of treatment (1-10 d), but while only a few patients in the convalescence stage. The serum Mg level was found to be positively correlated with PaO2 (r = 0.146, P less than 0.05) and blood chlorine (Cl-) level (r = 0.236, P less than 0.01) and negatively correlated with PaCO2 (r = -0.012, P less than 0.05). All patients with hypomagnesemia had acid-base disorder. We found that the prognosis of patients with chronic cor pulmonale was closely related to hypomagnesemia. We also found that in order to cure patients with hypomagnesemia, combined treatment was necessary for long-term improvement of the general condition.

Development of neutralizing antibodies and group A common antibodies against natural infections with human rotavirus

We determined the levels of group A common and neutralizing antibodies against human rotavirus in paired serum specimens obtained from 38 infants within 12 days of the onset of diarrhea. Thirty of the infants excreted rotavirus in stools, and eight did not. Nine patients (30%) with rotavirus diarrhea and seven patients (88%) with diarrhea due to other causes had detectable levels (greater than or equal to 1: 80) of immunoglobulin (IgG) common antibodies in acute-phase sera. All the patients with rotavirus diarrhea showed at least fourfold rises in titers of IgG or IgM common antibodies or both, while only two control patients showed significant rises in either IgG or IgM common antibodies in their convalescent-phase sera. Of the 19 patients excreting "short" electropherotypes of rotavirus, 18 showed at least fourfold rises in titers of neutralizing antibodies against serotype 2 human rotavirus but not against serotype 1, 3, or 4. Nine of the ten patients excreting "long" electropherotypes showed significant rises in neutralizing antibodies against serotype 3, and the other patient showed a significant rise in neutralizing antibodies against serotype 1. One patient excreted long and short electropherotypes simultaneously, and he also showed a significant rise in neutralizing antibodies against serotype 2 and 3 viruses. The control patients with diarrhea did not show significant changes in titers of antibodies against any of the serotypes. These results demonstrated that the neutralizing antibody response within 2 weeks after clinical onset is specific for the infecting serotype of rotavirus.