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.

Resumption of menstruation and pituitary response to gonadotropin-releasing hormone in functional hypothalamic amenorrhea subjects undertaking estrogen replacement therapy

BACKGROUND

Functional hypothalamic amenorrhea (FHA) refers to a functional menstrual disorder with various causes and presentations. Recovery of menstrual cyclicity is common in long-term follow-up but the affecting factors remain unknown.

AIM

To explore factors affecting the menstrual resumption and to evaluate the pituitary response to gonadotropin-releasing hormone (GnRH) in FHA.

MATERIALS AND METHODS

Thirty cases with FHA were recruited. All subjects were put on continuous 1 mg/day estradiol valerate orally and followed up monthly. Recovery was defined as the occurrence of at least three consecutive regular cycles. Responder referred to those who recovered within two years of therapy. Gonadotropin response to the 50 μg GnRH challenge was tested every three months.

RESULTS

Nineteen (63.3%) subjects recovered with a mean time to recovery of 26.8 months. Time to recovery was negatively correlated with body mass index (BMI) before and by amenorrhea. Twentyone cases had undertaken therapy for more than two years and 10 of them recovered. BMI before and by amenorrhea were negatively correlated with the recovery. Significant increase of serum luteinizing hormone (LH) and LH response to GnRH were noted after recovery.

CONCLUSIONS

Menstrual resumption was common in FHA undertaking estrogen replacement therapy (ERT). The likelihood of recovery was affected by their BMI before and by amenorrhea but not by the weight gain during therapy. Low serum LH and attenuated LH response to GnRH were the main features of pituitary deficiency in FHA. The menstrual resumption in FHA was accompanied by the recovery of serum LH and the LH response to GnRH.

Effects of copper-aspirin complex on plasma 6-keto-prostaglandin F1αlevel and platelet cytosolic calcium in rabbits

Effects of copper-aspirin complex on washed platelet aggregation, thromboxane B(2) formation and 6-ketoprostaglandin F(1alpha) level were monitored by Born's and Terashita's methods, respectively. The influence of copper-aspirin complex on cytosolic free calcium was examined using the fluorescent indicator, Fura 2-AM. Copper-aspirin complex significantly inhibited arachidonic acid-induced aggregation in washed platelets. The IC(50) value was 9.6 micromol L(-1). Copper-aspirin complex significantly decreased arachidonic acid-induced thromboxane B(2) formation by 87.1% in washed platelets. Ten mg kg(-1) of copper-aspirin complex given intragastrically markedly increased the plasma level of 6-keto-prostaglandin F(1alpha). Aspirin, however, reduced both thromboxane B(2) formation and 6-keto-prostaglandin F(1alpha) level. In the presence of CaCl2 1 mmol L(-1), copper-aspirin complex (20, 40 and 80 micromol L(-1)) markedly lowered arachidonic acid-induced increase in platelet calcium from the resting level (270+/-36 nmol L(-1)) to 213+/-14, 170+/-20 and 135+/-17 nmol L(-1), respectively. In the presence of ethylene glycol-bis (beta-aminoethyl ether) N,N,N',N'-tetraacetic acid 1 mmol L(-1), copper-aspirin complex (20, 40 and 80 micromol l L(-1)) significantly suppressed the release of intracellular calcium induced by arachidonic acid from 127+/-23 nmol L-1 to 108+/-17, 93+/-12 and 70+/-13 nmol L(-1).

A novel flocculant of Al(OH)3–polyacrylamide ionic hybrid

A novel flocculant based on hybrid Al(OH)(3)-polyacrylamide (HAPAM) has been synthesized using a redox initiation system ((NH(4))(2)S(2)O(8)-NaHSO(3)) at 40 degrees C in aqueous medium. The HAPAM was characterized by viscometry, IR spectroscopy, TEM, conductivity, and TGA. The flocculation behavior for 0.25 wt% kaolin suspension was evaluated by spectrophotometry and phase contrast microscopy. It was found that an ionic bond exists between Al(OH)(3) colloid and polyacrylamide (PAM) chains in the HAPAM and the flocculation efficiency of HAPAM is much better than that of commercial polyacrylamide (PAM) and PAM/AlCl(3) blend.

Effect of copper aspirinate on contraction of isolated rabbit aortic strips

AIM

To investigate the effect of copper aspirinate on contraction of vascular smooth muscle.

METHODS

Isolated rabbit aortic strips, including intact endothelium strips and endothelial cell-denuded aortic strips, were suspended in modified Krebs'solution to determine effects of copper aspirinate on the contraction induced by norepinephrine (NE), KCl, and CaCl2, while CuSO4, aspirin, and vehicle were used as controls.

RESULTS

Copper aspirinate possessed antagonistic effect on contraction of rabbit aortic strips induced by NE with an IC50 value of 31 nmol/L, while CuSO4 had much l ess antagonistic effect with an IC50 value of 0.29 micromol/L, and aspirin did not work in the same preparation. No effect of copper aspirinate were found on the contraction induced by KCl and CaCl2. Effects on endothelial cell denuded aortic strips were similar to those in the normal aortic strips.

CONCLUSION

Copper aspirinate possessed different effects from aspirin and CuSO4 on vascular smooth muscles. It inhibited contraction induced by NE with an activity stronger than CuSO4 at the same Cu2+ concentration, this action might be due to blockade of the receptor-operated Ca2+ channels, and it might not be linked to the endothelium.

Paeonilide, a novel anti-PAF-active monoterpenoid-derived metabolite from Paeonia delavayi

A novel monoterpenoid-derived metabolite, paeonilide, was isolated from the roots of Paeonia delavayi. Its structure was established by a combination of spectroscopic and X-ray crystallographic analyses. It showed an anti-PAF effect with an IC50 value of ca. 8 microg/ml.

Effect of protopine on cytosolic Ca2+ in rabbit platelets

AIM

To study the influence of protopine (Pro) on the cytoplasmic free Ca2+ concentration ([Ca2+]i) in rabbit platelets.

METHODS

Measurement of [Ca2+]i of platelets in vitro by Fura 2-AM fluorescence technique.

RESULTS

In the presence of CaCl2 1 mmol.L-1, Pro 10, 20, and 40 mumol.L-1 attenuated the rise in [Ca2+]i evoked by ADP from (420 +/- 57) to (320 +/- 26), (264 +/- 21), and (180 +/- 14) nmol.L-1, respectively, by arachidonic acid (AA) from (280 +/- 36) to (210 +/- 17), (184 +/- 21), and (143 +/- 16) nmol.L-1, respectively, and by platelet-activating factor (PAF) from (350 +/- 42) to (282 +/- 31), (223 +/- 30), and (165 +/- 15) nmol.L-1, respectively. In the presence of egtazic acid 1 mmol.L-1, Pro 10, 20, and 40 mumol.L-1 reduced the Ca2+ release induced by ADP, AA, and PAF, respectively. Pro 10, 20, and 40 mumol.L-1 also decreased ADP-, AA-, and PAF-induced Ca2+ influx.

CONCLUSION

Pro inhibited not only Ca2+ release but also the influx of Ca2+.

Effects of copper-aspirin complex on platelet aggregation and thrombosis in rabbits and mice

The effects of intragastric and intraduodenal copper-aspirin complex on rabbit platelet aggregation were observed by Born's method. Myers's method was used to evaluate the antithrombotic effect of copper-aspirin complex in mice. In-vitro copper-aspirin complex selectively inhibited arachidonic acid-induced platelet aggregation with an IC50 value (concentration resulting in 50% inhibition) of 13.2 microM (95% confidence limits 9.1-16.8 microM). Copper-aspirin complex (10 mg kg(-1) given intragastrically or intraduodenally) was more potent than aspirin in inhibiting arachidonic acid-induced platelet aggregation. Copper-aspirin complex (10 mg kg(-1)) had a stronger inhibitory effect and a longer duration of action when given intragastrically than when given intraduodenally. It was shown by radioimmunoassay that copper-aspirin complex significantly reduced the level of thromboxane B2 in plasma while markedly increasing that of 6-ketoprostaglandin F1alpha (6keto-PGF1alpha). Copper-aspirin complex (10 mg kg(-1) given intragastrically for 7 days) significantly reduced mouse mortality caused by intravenous injection of arachidonic acid. The results suggest that both in-vitro and in-vivo copper-aspirin complex is more potent in selectively inhibiting arachidonic acid-induced platelet aggregation than aspirin. When given intragastrically the complex has a more potent antiplatelet effect and a longer duration of action than when given intraduodenally. The antithrombotic effect of the complex was more potent than that of aspirin.

Inhibitory effects of copper-aspirin complex on platelet aggregation

AIM

To study the inhibitory effects of copper-aspirin complex (CuAsp) on platelet aggregation.

METHODS

With adenosine diphosphate the effects of CuAsp on platelet aggregation in vitro or in vivo were investigated. Radioimmunoassay and fluorophotometry were used to measure thromboxane B2 (TXB2) generation from platelets, the levels of TXB2 and of 6-keto-PGF1 alpha in plasma and the platelet serotonin release reaction.

RESULTS

In vitro, CuAsp inhibited arachidonic acid (AA)-induced aggregation (IC50 = 17 mumol.L-1, 95% confidence limits: 9-33 mumol.L-1), the release of 5-HT (IC50 = 19 mumol.L-1, 95% confidence limits: 10-30 mumol.L-1), and TXB2 generation from platelets (P < 0.05). CuAsp 10 mg.kg-1 i.g. selectively inhibited AA-induced aggregation, and increased the 6-keto-PGF1 alpha concentration in plasma while decreased that of TXB2.

CONCLUSION

CuAsp, in vitro or in vivo, shows more potent inhibitory effects on AA-induced aggregation than aspirin (Asp), related to the inhibition of platelet cyclooxygenase and the release of active substances from platelets.

Coordination of copper with aspirin enhances its anti-platelet aggregation activity

Anti-platelet aggregation of copper aspirinate, a copper complex of aspirin, has been studied in vitro and in vivo. The result shows that copper aspirinate is much more effective than aspirin against AA-, ADP- and PAF-induced platelet aggregation. Its mechanism is related to the inhibition of platelet cyclooxygenase and release of active substances from platelets, and to the promotion of PGI(2) level in plasma.

Application of biotin-avidin system, determination of circulating immune complexes, and evaluation of antibody response in different hydatidosis patients

The avidin-biotin-peroxidase complex enzyme-linked immunosorbent assay (ABC-ELISA) and standard ELISA were used for the detection of Echinococcus granulosus antibody in sera of 101 patients operated on for hydatid disease, 40 patients with miscellaneous nonhydatid diseases, and 61 normal subjects. Sensitivity and specificity of the two procedures were comparable and the geometric mean antibody titer detected with ABC-ELISA was higher than with standard ELISA. The ABC-ELISA is a sensitive, specific, simple, and convenient method for diagnosing hydatidosis.