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.

The JAK2/STAT3 and mitochondrial pathways are essential for quercetin nanoliposome-induced C6 glioma cell death

The formulation of quercetin nanoliposomes (QUE-NLs) has been shown to enhance QUE antitumor activity in C6 glioma cells. At high concentrations, QUE-NLs induce necrotic cell death. In this study, we probed the molecular mechanisms of QUE-NL-induced C6 glioma cell death and examined whether QUE-NL-induced programmed cell death involved Bcl-2 family and mitochondrial pathway through STAT3 signal transduction pathway. Downregulation of Bcl-2 and the overexpression of Bax by QUE-NL supported the involvement of Bcl-2 family proteins upstream of C6 glioma cell death. In addition, the activation of JAK2 and STAT3 were altered following exposure to QUE-NLs in C6 glioma cells, suggesting that QUE-NLs downregulated Bcl-2 mRNAs expression and enhanced the expression of mitochondrial mRNAs through STAT3-mediated signaling pathways either via direct or indirect mechanisms. There are several components such as ROS, mitochondrial, and Bcl-2 family shared by the necrotic and apoptotic pathways. Our studies indicate that the signaling cross point of the mitochondrial pathway and the JAK2/STAT3 signaling pathway in C6 glioma cell death is modulated by QUE-NLs. In conclusion, regulation of JAK2/STAT3 and ROS-mediated mitochondrial pathway agonists alone or in combination with treatment by QUE-NLs could be a more effective method of treating chemical-resistant glioma.

Three-dimensional contrast-enhanced magnetic resonance angiography at 3.0T scanner: significance in the classification of peripheral arterial occlusive disease

AIM

Aim of this study was to evaluate the clinical efficacy of three-dimensional contrast-enhanced magnetic resonance angiography (3D CE-MRA); at 3.0T scanner in the classification of peripheral arterial occlusive disease (PAOD).

METHODS

Thirty-five patients diagnosed of PAOD underwent 3D CE-MRA, 30 cases underwent digital subtracted angiography (DSA) successfully, and 12 cases underwent surgery.

RESULTS

The vascular tree from the distal aorta to the lower limbs was well demonstrated. The extent and grade of disease seen in 3D CE-MRA closely matched those seen in DSA and/or surgery. Compared to the results of DSA and/or surgery, the common coincidence of 3D CE-MRA in diagnosing PAOD was 96.89% (780/805), the coincidence in diagnosing mild, moderate, severe stenosis and occlusion was 90.48% (76/84), 87.14% (61/70), 95.77% (68/71), and 98.29% (115/117) respectively, the rate of overestimate in mild, moderate, and severe stenosis was 5.95% (5/84), 10% (7/70), and 2.82% (2/71) respectively, the rate of underestimate in mild, moderate, severe stenosis and occlusion was 3.57% (3/84), 2.86% (2/70), 1.41% (1/71) and 1.74% (2/115) respectively.

CONCLUSION

3D CE-MRA at 3.0T scanner is of great value in the accurate assessment of the classification of PAOD; it is a reliable and promising new technique.

Hydrodynamic conditions in designed spiral photobioreactors

In this work, a series of spiral tube PBRs were introduced. Flow dynamics of microalgae fluid, light intensity histories of tracked cells and swirl numbers within the spiral PBRs were numerically simulated. Results show that strong swirl motions are formed in the cross-sections along axial coordinate of spiral PBRs, but no such vortice is observed for tubular PBR. The light intensity histories identify that the microalgae cells experience the so-called light/dark cycle, which is necessary to their growth. With high swirl numbers ranging from 0.15 to 0.35, the mixing performances of the spiral tube PBRs are much better than that of tubular PBR, indicating such innovative geometries of spiral tube PBRs may be applicable for large scale commercial cultivation of microalgae in the future.

Intramucosal carcinomas of the stomach: phenotypic expression and loss of heterozygosity at microsatellites linked to the APC gene

Evaluation of the role of somatic genetic alterations in cancer development is best performed by examining small tumors in the earlier stages of carcinogenesis. We examined the relationship between allelic deletions of 4 microsatellites linked to the adenomatous polyposis coli (APC) gene and differential histogenetical phenotypes in 34 intramucosal carcinomas of the stomach, of which, structurally, 24 cases were the gland-forming type (so-called "intestinal type") and 10 were the diffuse type. Using mucin and immunohistochemical staining techniques specific for gastric- and intestinal-type mucins, the phenotype of each tumor was histogenetically classified as exclusively gastric, predominantly gastric, predominantly intestinal or exclusively intestinal. There was generally a free combination between structural types and phenotypic mucin expression. Allelic deletions were detected in 6 carcinomas of the exclusively intestinal phenotype. The incidence of allelic deletions was significantly higher in the predominantly and exclusively intestinal phenotypes (6/16, 37.5%) than in the predominantly and exclusively gastric phenotypes (0/18) (p = 0.0060, Fisher's test). Taking the high frequency of allelic deletions in 5q in invasive stomach carcinomas, the present study suggests that genetic alteration in this region is a very early event in stomach carcinomas with intestinal differentiation but a relatively late event in those with gastric differentiation.

[Bronchopulmonary infection due to Branhamella catarrhalis in patients with obstructive lung disease]

During the period from February 1988 to April 1990, 214 sputum samples from COPD patients with bronchopulmonary infection were quantitatively cultured. 17 strains were identified as Branhamella catarrhalis, being present in 7.9% of all sputum cultures and 11.0% of those positive for a pathogen (Quantity = 10(10)/L of Isolated Organism). Half of B. catarrhalis infection was isolated in mixed with other pathogens. Haemophilus influenza was the most frequently associated pathogen. The second was H. influenza plus Streptococcus pneumoniae. Of 17 B. catarrhalis, 2 strains were positive for beta-lactamase. The incidence of B. catarrhalis infection varied with the seasons, being prevalent in late winter and early spring. Many factors contributed to the pathogenicity of B. catarrhalis, such as the rapid increase of positive beta-lactamase strains and the change of seasons. The result showed that B. catarrhalis was the fourth frequent pathogen in COPD patients accompanied with bronchopulmonary infection. Most of the strains were resistant to penicillin, and beta-lactamase strains were discovered. Therefore, B. catarrhalis should be as a potential pathogen to be identified in sputum. A suitable method was recommended to identified B. catarrhalis.