Available online xxxKeywords: Hydrogen storage material Orderedisorder (OD) theory Polytype Scanning transmission electron microscopy Superlattice structure La 2 Ni 7 a b s t r a c tThe new crystal structure of the intermetallic compound (Nd,Mg) 2 (Ni,Al) 7 has been determined by scanning transmission electron microscopy and electron diffraction. This crystal structure is different from that (either 2H or 3R) usually reported for the intermetallic compound R 2 T 7 (R: rare-earth elements and T: transition-metal elements) in the constitution of block layers. While the block layer for the crystal structure usually reported is of the R 2 T 7 stoichiometric composition consisting of one R 2 T 4 unit layer and two RT 5 unit layers, the block layer for the new crystal structure consists of a sub-block layer of the RT 3 stoichiometry (formed with one R 2 T 4 unit layer and one RT 5 unit layer) and a sub-block layer of the R 5 T 19 stoichiometry (formed with one R 2 T 4 unit layer and three RT 5 unit layers), which alternately stack on top of each other. The crystal structure is described based on the orderedisorder (OD) theory and the simplest crystal structures (polytypes) among many other polytypes belonging to the same OD family is deduced to be of the 2H-type with the space group of P6m2 and of the 6R-type with the space group of R3m. The experimentally observed polytype corresponds to the second simplest form of the 6R-type.

Atomic scale characterization of the La2Ni7 hydrides by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) revealed that not only the anisotropic expansion of the La2Ni4 unit layer previously reported but also the shearing on the basal plane of the La2Ni4 unit layers occur during one-cycle of hydrogen absorption/desorption process. Two different types of orthorhombic La2Ni7 hydrides with the same atomic arrangement of La and different atomic arrangement of Ni were observed depending on the maximum hydrogen concentration achieved during one hydrogen absorption/desorption cycle.

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In order to prevent a crisis due to the increasing elderly population in 2025, home medical care should be enforced and promoted. Therefore, pharmacists are expected to play their roles in home medical care. However, pharmacistsʼ involvement in home medical care remains inadequate in Japan. In this study, a nationwide questionnaire survey was conducted on the awareness of visiting nurses about the roles of pharmacists in home medical care, and data were analyzed using the text mining method. A request letter was posted to 47 prefectural branches of the Japanese Nursing Association and 28 prefectural branches of The National Association for Visiting Nurse Service. Only members of these associations who agreed to participate in this survey responded. As a result, a total of 103 visiting nurses completed the questionnaires. "Distribution of medicines to the medication calendar" was one of the main medicine-related jobs performed by visiting nurses during home medical care. The majority of them (95％ of visiting nurses replied "it is necessary") indicated that pharmacistsʼ activity was required for home medical care. According to visiting nurses, the job expected from pharmacists in home medical care was the "centralized unitary management of medicines in collaboration with medical doctors." In summary, our survey results suggest that an active intervention to polypharmacy by pharmacists in collaboration with home medical doctors is important for home medical care.