Hydrogen Clathrate Structures in Uranium Hydrides at High Pressures.

Room-temperature superconductivity has always been an area of intensive research. Recent findings of clathrate metal hydrides structures have opened up the doors for achieving room-temperature superconductivity in these materials. Here, we report first-principles calculations for stable H-rich clathrate structures of uranium hydrides at high pressures. The clathrate uranium hydrides contain H cages with stoichiometries of H24, H29, and H32, in which H atoms are bonded covalently to other H atoms, and U atoms occupy the centers of the cages. Especially, a UH10 clathrate structure containing H32 cages is predicted to have an estimated T c higher than 77 K at high pressures.

Clinical Features of Pituitary Stalk Interruption Syndrome in 114 Cases.

Objective To analyze the clinical characteristics of pituitary stalk interruption syndrome(PSIS). Methods The clinical data including clinical manifestations,laboratory tests,and imaging findings of 114 PSIS patients in our hospital were retrospectively analyzed. Results Of these 114 PSIS patients,102 cases (89.4%) were male. The average age was 21.1?6.1 years. A history of breech delivery was documented in 91 cases (91.9%). Short stature was found in 89 cases (71.8%) and bone age delayed (6.1?5.1) years. Secondary sex characteristics were poor or undeveloped in most patients. The prevalence of deficiencies in growth hormone,gonadotropins,corticotropin,and thyrotropin were 100.0%,94.0%,84.2%,and 74.6%,respectively. Hyperprolactinemia was found in 28.1% of patients. Three or more pituitary hormone abnormalities were found in 105 cases(92.1%). Compared with the 5 cases with history of cephalic delivery,no difference were found in the aspects of height(t=0.297,P=0.634),penile length(t=1.205,P=0.882),testicular volume (U=99.000,P=0.348),growth hormone peak (U=89.000,P=0.186),adrenocorticotropic hormone peak(U=131.000,P=0.967),luteinizing hormone peak(U=98.500,P=0.582),thyroid-stimulating hormone (U=82.000,P=0.162),and the height of anterior pituitary (t=1.676,P=0.107) in the 53 cases with history of breech delivery. Conclusions The clinical manifestations,symptoms,hormone deficiencies were severe in our series. The condition severities were not remarkably different in patients with different delivery ways.

Experimental and numerical study of shock-accelerated elliptic heavy gas cylinders.

We studied the evolution of elliptic heavy SF6 gas cylinder surrounded by air when accelerated by a planar Mach 1.25 shock. A multiple dynamics imaging technology has been used to obtain one image of the experimental initial conditions and five images of the time evolution of elliptic cylinder. We compared the width and height of the circular and two kinds of elliptic gas cylinders and analyzed the vortex strength of the elliptic ones. Simulations are in very good agreement with the experiments, but due to the different initial gas cylinder shapes, a certain difference of the initial density peak and distribution exists between the circular and elliptic gas cylinders, and the latter initial state is more sensitive and more inenarrable.