Local electronic structure rearrangements and strong anharmonicity in YH3 under pressures up to 180 GPa

The authors acknowledge the ESRF program committee (Grenoble, France) for the opportunity to perform XAFS and XRD measurements. We are grateful to Prof. Dr Marek Tkacz from the Institute of Physical Chemistry, PAS Kasprzaka 44/52, 01-224 Warsaw, Poland, for high quality YH3 samples and to Dr. José A. Flores-Livas for a fruitful discussion. A.P.M. and A.A.I. acknowledge the Russian Foundation for the Basic Research (grant No 18-02-40001_mega) for financial support. J.P., A.K., and I.P. would like to thank the support of the Latvian Council of Science project No. lzp-2018/2-0353. ISSP UL acknowledge the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-20l 6-2017-TeamingPhase2, grant agreement No. 739508, project CAMART2.The discovery of superconductivity above 250 K at high pressure in LaH10 and the prediction of overcoming the room temperature threshold for superconductivity in YH10 urge for a better understanding of hydrogen interaction mechanisms with the heavy atom sublattice in metal hydrides under high pressure at the atomic scale. Here we use locally sensitive X-ray absorption fine structure spectroscopy (XAFS) to get insight into the nature of phase transitions and the rearrangements of local electronic and crystal structure in archetypal metal hydride YH3 under pressure up to 180 GPa. The combination of the experimental methods allowed us to implement a multiscale length study of YH3: XAFS (short-range), Raman scattering (medium-range) and XRD (long-range). XANES data evidence a strong effect of hydrogen on the density of 4d yttrium states that increases with pressure and EXAFS data evidence a strong anharmonicity, manifested as yttrium atom vibrations in a double-well potential.--//--This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.Russian Foundation for the Basic Research (grant No 18-02-40001_mega); Latvian Council of Science project No. lzp-2018/2-0353; European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-20l 6-2017-TeamingPhase2, grant agreement No. 739508, project CAMART2

Local electronic structure rearrangements and strong anharmonicity in YH3 under pressures up to 180 GPa

The authors acknowledge the ESRF program committee (Grenoble, France) for the opportunity to perform XAFS and XRD measurements. We are grateful to Prof. Dr Marek Tkacz from the Institute of Physical Chemistry, PAS Kasprzaka 44/52, 01-224 Warsaw, Poland, for high quality YH3 samples and to Dr. José A. Flores-Livas for a fruitful discussion. A.P.M. and A.A.I. acknowledge the Russian Foundation for the Basic Research (grant No 18-02-40001_mega) for financial support. J.P., A.K., and I.P. would like to thank the support of the Latvian Council of Science project No. lzp-2018/2-0353. ISSP UL acknowledge the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-20l 6-2017-TeamingPhase2, grant agreement No. 739508, project CAMART2.The discovery of superconductivity above 250 K at high pressure in LaH10 and the prediction of overcoming the room temperature threshold for superconductivity in YH10 urge for a better understanding of hydrogen interaction mechanisms with the heavy atom sublattice in metal hydrides under high pressure at the atomic scale. Here we use locally sensitive X-ray absorption fine structure spectroscopy (XAFS) to get insight into the nature of phase transitions and the rearrangements of local electronic and crystal structure in archetypal metal hydride YH3 under pressure up to 180 GPa. The combination of the experimental methods allowed us to implement a multiscale length study of YH3: XAFS (short-range), Raman scattering (medium-range) and XRD (long-range). XANES data evidence a strong effect of hydrogen on the density of 4d yttrium states that increases with pressure and EXAFS data evidence a strong anharmonicity, manifested as yttrium atom vibrations in a double-well potential.--//--This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.Russian Foundation for the Basic Research (grant No 18-02-40001_mega); Latvian Council of Science project No. lzp-2018/2-0353; European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-20l 6-2017-TeamingPhase2, grant agreement No. 739508, project CAMART2

РЕЗУЛЬТАТЫ РЕНTГЕНЭНДОВАСКУЛЯРНЫХ МЕТОДОВ ЛЕЧЕНИЯ ОПУХОЛЕВЫХ ПОРАЖЕНИЙ ПЕЧЕНИ В ЮЖНОМ КАЗАХСТАНЕ

In clause results endovascular methods of treatment of 70 patients with tumoral defeats of a liver of men 47 (67,1 %), women 23 (32,9 %), from them are presented: a primary cancer of a liver 42 (60 %) cases, metastatic defeats of a liver 28 (40 %). Chemo-infusions a hepatic artery it is executed at 50 patients, from them at a primary cancer of a liver at 32 (45,7 %) by patients, at metastatic defeats of a liver at 18 (25,7 %) patients. At 20 patients it is lead chemo-embolisations a hepatic artery, from them at a primary cancer of a liver 10 (17,1 %) by patients, at metastatic defeats of a liver 8 (11,4 %) patients. Data obtained by us have shown efficiency chemo-infusions a hepatic artery at a primary cancer of a liver at 19 (45,2 %) to patients with high quality of a life that enables wider application of a technique for rendering special treatment of this complex category of patients. Results chemo-embolisations a hepatic artery at a primary cancer of a liver also encourage, as after 1 procedure gives stabilization of process and improves quality of a life of patients. Цель: изучить непосредственные результаты химиоинфузии в печеночную артерию и химиоэмболизации печеночной артерии при опухолевых поражениях печени, выполненных за период 2004-2008 гг. по данным Южно-Казахстанского областного онкологического диспансера. Проанализированы результаты эндоваскулярных методов лечения 70 больных с опухолевыми поражениями печени, из них мужчин 47 (67,1%), женщин 23 (32,9%), первичный рак печени в 42 (60%) случаях, метастатические поражения печени в 28 (40%) случаях. Химиоинфузия печеночной артерии выполнена у 50 больных, из них при первичном раке печени у 32 (45,7%) больных, при метастатических поражениях печени у 18 (25,7%) больных. У 20 больных проведена химиоэмболизация печеночной артерии, из них при первичном раке печени 10 (17,1%) больным, при метастатических поражениях печени 8 (11,4%) больным. При первичном раке печени значительная регрессия отмечена у 2 (4,76%) больных, они наблюдаются в течение 3-х лет без признаков прогрессирования процесса, частичная регрессия отмечена у 6 (14,3%) больных, стабилизация процесса у 16 (38%) и прогрессирование процесса у 8 (19%) больных. После лечения до года со стабилизацией процесса живут 14 (33,3%) больных, 1,5 года живут 3 (7,14%) больных, в сроки от 4 до 8 месяцев после лечения умерло 13 (30,9%) больных. После химиоэмболизации печеночной артерии (ХЭПА) у 8 из 10 больных отмечена частичная регрессия процесса, которая наблюдается в течение 3-5 месяцев, в настоящее время этим больным в плановом порядке проводится 2 и 3 сеансы ХЭПА. Отмечена эффективность ХИПА при первичном раке печени у 19 (45,2%) больных с хорошим качеством жизни, что дает возможность более широкого применения методики для оказания специального лечения этой сложной категории пациентов. Результаты ХЭПА при первичном раке печени также обнадеживают, так как после одной процедуры наступает стабилизация процесса и улучшается качество жизни пациентов

Особенности экстраорганной вариантной анатомии чревного ствола и печеночной артерии у больных раком печени

Introduction. Knowledge of the different variants of the structure of the celiac trunk and the hepatic artery is of great importance in the planning, treatment and choice of approaches for transcatheter vascular interventions.Objective: to study features of variant hematopoietic anatomy from direct and multispiral computed tomography angiography (MSCTA) data in order to determine its significance in routine clinical practice.Materials and methods. We analysed the most common variants of branching of the celiac trunk and anatomy of the hepatic artery according to direct angiography and MSCTA data in 112 patients with primary liver cancer. The sample comprised 71 men (63.3 %) and 41 women (36.7 %).Results and discussion. It was found that the most frequent aberration was the passage of the replacement right hepatic artery from the superior mesenteric artery — type 3 according to N. Michels. The second aberration in terms of frequency was Michels type 2. We describe two unusual celiac trunk and hepatic anatomy variants: the first of these comprising a celiac trunk 22 cm long extending from the superior mesenteric artery; the second consisting in a complete absence of the celiac trunk, with all its elements (left gastric artery, common hepatic artery and splenic artery) departing independently from the abdominal aorta.Conclusions. A typical anatomy of the celiac trunk and hepatic artery was found in 60 % of cases, the most frequent aberration being the Michels type 3, noted in 14.2 % of patients, and type 2 noted in 9.8 % of patients. Knowledge of individual blood supply features largely determines the procedure for conducting operations, permitting purposeful intraoperative revision and the selection of the optimal vascular reconstruction variant, and avoiding damage to aberrant arteries. Введение. Знание различных вариантов строения чревного ствола и печеночной артерии имеет большое значение в планировании, лечении и выборе тактики проведения транскатетерных сосудистых вмешательств.Цель исследования: изучить особенности вариантной анатомии печеночной артерии по данным прямой и мультиспиральной компьютерно-томографической ангиографии, определить ее значение в рутинной клинической практике.Материалы и методы. Нами был проведен анализ наиболее часто встречаемых вариантов ветвления чревного ствола и анатомии печеночной артерии по данным прямой ангиографии и МСКТ ангиографии печени у 112 пациентов с первичным раком печени. Мужчин было 71 (63,3 %), женщин 41 (36,7 %).Результаты и обсуждение. Установлено, что самой частой аберрацией было отхождение замещающей правой печеночной артерии от верхней брыжеечной артерии — 3 тип по N. Michels. Вторым по частоте встречаемости оказался 2 тип по N. Michels. Нами описаны два варианта редкой анатомии чревного ствола и печеночной артерии: первая — чревный ствол длиной 22 см отходит от верхней брыжеечной артерии; вторая — полное отсутствие чревного ствола, все ее элементы (левая желудочная артерия, общая печеночная артерия и селезеночная артерия) отходят самостоятельно от брюшной аорты.Выводы. Типичная анатомия чревного ствола и печеночной артерии встречалась в 60 % случаев, самой частой аберрацией был третий тип по N. Michels, отмечен в 14,2 %, и тип 2 по N. Michels, отмечен в 9,8 %. Знание индивидуальных особенностей кровоснабжения во многом определяет методику проведения операций, позволяет целенаправленно проводить интраоперационную ревизию, выбирать оптимальный вариант сосудистой реконструкции, избежать повреждения аберрантных артерий

Peculiarities of Extra-Organic Variant Anatomy of the Celiac Trunk and Hepatic Artery in Patients with Liver Cancer

Introduction. Knowledge of the different variants of the structure of the celiac trunk and the hepatic artery is of great importance in the planning, treatment and choice of approaches for transcatheter vascular interventions.Objective: to study features of variant hematopoietic anatomy from direct and multispiral computed tomography angiography (MSCTA) data in order to determine its significance in routine clinical practice.Materials and methods. We analysed the most common variants of branching of the celiac trunk and anatomy of the hepatic artery according to direct angiography and MSCTA data in 112 patients with primary liver cancer. The sample comprised 71 men (63.3 %) and 41 women (36.7 %).Results and discussion. It was found that the most frequent aberration was the passage of the replacement right hepatic artery from the superior mesenteric artery — type 3 according to N. Michels. The second aberration in terms of frequency was Michels type 2. We describe two unusual celiac trunk and hepatic anatomy variants: the first of these comprising a celiac trunk 22 cm long extending from the superior mesenteric artery; the second consisting in a complete absence of the celiac trunk, with all its elements (left gastric artery, common hepatic artery and splenic artery) departing independently from the abdominal aorta.Conclusions. A typical anatomy of the celiac trunk and hepatic artery was found in 60 % of cases, the most frequent aberration being the Michels type 3, noted in 14.2 % of patients, and type 2 noted in 9.8 % of patients. Knowledge of individual blood supply features largely determines the procedure for conducting operations, permitting purposeful intraoperative revision and the selection of the optimal vascular reconstruction variant, and avoiding damage to aberrant arteries

Superconductivity at 215 K in lanthanum hydride at high pressures

We synthesized lanthanum hydride (LaHx) by laser heating of lanthanum in hydrogen atmosphere at pressure P = 170 GPa. The sample shows a superconducting step at 209 K and 170 GPa and temperature dependence of resistance. By releasing the pressure to 150 GPa, the superconducting transition temperature Tc increases to 215 K - the record Tc. This finding supports a way of achieving Tc higher than the one in H3S (203 K) in hydrides with sodalite-like structures, first proposed for CaH6 (Tc=245 K) and later for yttrium and lanthanum hydrides where higher, room temperature superconductivity is expected

Superconductivity at 250 K in lanthanum hydride under high pressures

With the discovery of superconductivity at 203 kelvin in H3S, attention returned to conventional superconductors with properties that can be described by the Bardeen–Cooper–Schrieffer and the Migdal–Eliashberg theories. Although these theories predict the possibility of room-temperature superconductivity in metals that have certain favourable properties—such as lattice vibrations at high frequencies—they are not sufficient to guide the design or predict the properties of new superconducting materials. First-principles calculations based on density functional theory have enabled such predictions, and have suggested a new family of superconducting hydrides that possess a clathrate-like structure in which the host atom (calcium, yttrium, lanthanum) is at the centre of a cage formed by hydrogen atoms2,3,4. For LaH10 and YH10, the onset of superconductivity is predicted to occur at critical temperatures between 240 and 320 kelvin at megabar pressures3,4,5,6. Here we report superconductivity with a critical temperature of around 250 kelvin within the Fm3¯m structure of LaH10 at a pressure of about 170 gigapascals. This is, to our knowledge, the highest critical temperature that has been confirmed so far in a superconducting material. Superconductivity was evidenced by the observation of zero resistance, an isotope effect, and a decrease in critical temperature under an external magnetic field, which suggested an upper critical magnetic field of about 136 tesla at zero temperature. The increase of around 50 kelvin compared with the previous highest critical temperature1 is an encouraging step towards the goal of achieving room-temperature superconductivity in the near future