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Objective To evaluate the efficacy of ventriculoperitoneal shunt in patients with secondary normal pressure hydrocephalus by using the diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT). Methods 3.0T MRI was performed on 22 patients before and 1 month after their ventriculoperitoneal shunts, DTI and DTT imaging were performed simultaneously. We recorded the values of fractional anisotropy (FA) and mean diffusivity(MD) around the ventricle, the number of white matter fiber tracts around the lateral ventricle, and the orientation and distribution of neural fiber tracts. Results After ventriculoperitoneal shunts were performed, the values of FA and MD were decreased significantly (P < 0.01), the number of white matter fiber tracts around the lateral ventricle were obviously increased (P < 0.01), and the compression rate of fiber tracts was reduced (P < 0.01). Among the poor rehabilitative patients, the values of FA and MD around the ventricle were decreased significantly (P < 0.01). We calculated the differences of FA value (dFA) and MD value (dMD) and the number of fiber tracts before and after operation, the results suggested that the dFA was higher in the patients of better rehabilitation than those of poor rehabilitative outcomes. The dMD were higher and the number of fiber tracts was increased in the better rehabilitative patients(P < 0.01). Conclusion The relevant items of DTI and DTT are significantly improved in the poor effective patients with normal pressure hydrocephalus after ventriculoperitoneal shunt. The changes of FA value around the lateral ventricle can predict the efficacy of the surgery. DTI and DTT techniques provide certain and valuable guidance for the organic improvement after ventriculoperitoneal shunt.

22Ne(α,n)25Mg is one of the main neutron sources of the s process. 22Ne is produced by the 14N(α, γ)18F(β+)18O(α, γ)22Ne reaction chain in the helium burning, thus, the production rate of 22Ne is dominated by 14N(α,γ)18F and 18O(α,γ)22Ne. At the astrophysical relevant temperatures, the 18O(α,γ)22Ne reaction rates are determined by several low-energy resonances. In this work, the 18O(α,γ)22Ne reaction was measured at the 400 kV accelerator of Jinping Underground Nuclear Astrophysics experiment (JUNA). The γ-ray yields of the resonances between 470 to 770 keV were obtained.

The cosmic 1.809 MeV γ-ray emitted by the radioactive nucleus 26Al in the Galaxy is one of the key observation targets of the γ-ray astronomy. The 26Al is mainly produced by the 25Mg(p,γ)26Al reaction in the stellar Mg-Al reaction cycle. At the astrophysical relevant temperatures, the reaction rates of 25Mg(p,γ)26Al are dominated by several narrow resonances at low energy. This work reports a measurement of the low energy 25Mg(p,γ)26Al resonances at Jinping Underground Nuclear Astrophysics experimental facility (JUNA) in the China Jinping Underground Laboratory (CJPL).

Proposed mechanisms for the production of calcium in the first stars (population III stars)—primordial stars that formed out of the matter of the Big Bang—are at odds with observations1. Advanced nuclear burning and supernovae were thought to be the dominant source of the calcium production seen in all stars2. Here we suggest a qualitatively different path to calcium production through breakout from the ‘warm’ carbon–nitrogen–oxygen (CNO) cycle through a direct experimental measurement of the 19F(p, γ)20Ne breakout reaction down to a very low energy point of 186 kiloelectronvolts, reporting a key resonance at 225 kiloelectronvolts. In the domain of astrophysical interest2, at around 0.1 gigakelvin, this thermonuclear 19F(p, γ)20Ne rate is up to a factor of 7.4 larger than the previous recommended rate3. Our stellar models show a stronger breakout during stellar hydrogen burning than previously thought1,4,5, and may reveal the nature of calcium production in population III stars imprinted on the oldest known ultra-iron-poor star, SMSS0313-67086. Our experimental result was obtained in the China JinPing Underground Laboratory7, which offers an environment with an extremely low cosmic-ray-induced background8. Our rate showcases the effect that faint population III star supernovae can have on the nucleosynthesis observed in the oldest known stars and first galaxies, which are key mission targets of the James Webb Space Telescope9.Observation of a new resonance in the 19-fluorine to 20-neon thermonuclear reaction at the China JinPing Underground Laboratory (over 2 km below ground) may provide clues to observed discrepancies in calcium production in the evolution of the first stars. [ABSTRACT FROM AUTHOR]

The 25 Mg(p, γ) 26 Al reaction plays an important role in the study of cosmic 1.809 MeV γ-ray as a signature of ongoing nucleosynthesis in the Galaxy. At astrophysical temperature around 0.1 GK, the 25 Mg(p, γ) 26 Al reaction rates are dominated by the 92 keV resonance capture process. We report a precise measurement of the 92 keV 25 Mg(p, γ) 26 Al resonance in the day-one experiment at Jinping Underground Nuclear Astrophysics experiment (JUNA) facility in the China Jinping Underground Laboratory (CJPL). The resonance strength and ground state feeding factor are determined to be 3.8±0.3 ×10 -10  eV and 0.66±0.04, respectively. The results are in agreement with those reported in the previous direct underground measurement within uncertainty, but with significantly reduced uncertainties. Consequently, we recommend new 25 Mg(p, γ) 26 Al reaction rates which are by a factor of 2.4 larger than those adopted in REACLIB database at the temperature around 0.1 GK. The new results indicate higher production rates of 26g Al and the cosmic 1.809 MeV γ-ray. The implication of the new rates for the understanding of other astrophysical situations is also discussed., (Copyright © 2021 Science China Press. Published by Elsevier B.V. All rights reserved.)