EHPRG: The European High Pressure Research Group

Welcome

Welcome to the official website of the European High Pressure Research Group (EHPRG).

EHPRG is non-profitable academic association established in 1963 which is devoted to science and technology of matter under high pressure. It organizes an annual meeting which brings together hundreds of scientists of various fields, mainly physics, chemistry, Earth and planetary sciences, bio- and food science and technology.

The reasonable size of the group, low conference fees, and a friendly relationship between the attendants have made EHPRG meetings a major event in the European high-pressure community for more than half a century.

Upcoming EHPRG Meeting

The 57th European High Pressure Research Group Meeting on High Pressure Science and Technology (EHPRG-2019) will be held in Prague, Czech Republic, from 1st to 6th September 2019. The 57th EHPRG Meeting will be chaired by Jiří Prchal (Charles University, Prague, Czech Republic).
For more information, please visit the official webpage of the 57th EHPRG Meeting.

High-pressure in the headlines

Selection of high-pressure related titles from top scientific journals.

Adaptive mutability of colorectal cancers in response to targeted therapies

by Russo, M., Crisafulli, G., Sogari, A., Reilly, N. M., Arena, S., Lamba, S., Bartolini, A., Amodio, V., Magri, A., Novara, L., Sarotto, I., Nagel, Z. D., Piett, C. G., Amatu, A., Sartore-Bianchi, A., Siena, S., Bertotti, A., Trusolino, L., Corigliano, M., Gherardi, M., Lagomarsino, M. C., Di Nicolantonio, F., Bardelli, A.

The emergence of drug resistance limits the efficacy of targeted therapies in human tumors. The prevalent view is that resistance is a fait accompli: when treatment is initiated, cancers already contain drug-resistant mutant cells. Bacteria exposed to antibiotics transiently increase their mutation rates (adaptive mutability), thus improving the likelihood of survival. We investigated whether human colorectal cancer (CRC) cells likewise exploit adaptive mutability to evade therapeutic pressure. We found that epidermal growth factor receptor (EGFR)/BRAF inhibition down-regulates mismatch repair (MMR) and homologous recombination (HR) DNA repair genes, and concomitantly up-regulates error-prone polymerases in drug-tolerant (persister) cells. MMR proteins were also down-regulated in patient-derived xenografts and tumor specimens during therapy. EGFR/BRAF inhibition induced DNA damage, increased mutability and triggered microsatellite instability. Thus, like unicellular organisms, tumor cells evade therapeutic pressures by enhancing mutability.

7 Nov 2019 at 7:48pm

Graduate students under pressure

by McCartney, M.

5 Dec 2019 at 7:41pm

Magma reservoir failure and the onset of caldera collapse at Kilauea Volcano in 2018

by Anderson, K. R., Johanson, I. A., Patrick, M. R., Gu, M., Segall, P., Poland, M. P., Montgomery-Brown, E. K., Miklius, A.

Caldera-forming eruptions are among Earth’s most hazardous natural phenomena, yet the architecture of subcaldera magma reservoirs and the conditions that trigger collapse are poorly understood. Observations from the formation of a 0.8–cubic kilometer basaltic caldera at Kīlauea Volcano in 2018 included the draining of an active lava lake, which provided a window into pressure decrease in the reservoir. We show that failure began after <4% of magma was withdrawn from a shallow reservoir beneath the volcano’s summit, reducing its internal pressure by ~17 megapascals. Several cubic kilometers of magma were stored in the reservoir, and only a fraction was withdrawn before the end of the eruption. Thus, caldera formation may begin after withdrawal of only small amounts of magma and may end before source reservoirs are completely evacuated.

5 Dec 2019 at 7:41pm

Cyclic lava effusion during the 2018 eruption of Kilauea Volcano

by Patrick, M. R., Dietterich, H. R., Lyons, J. J., Diefenbach, A. K., Parcheta, C., Anderson, K. R., Namiki, A., Sumita, I., Shiro, B., Kauahikaua, J. P.

Lava flows present a recurring threat to communities on active volcanoes, and volumetric eruption rate is one of the primary factors controlling flow behavior and hazard. The time scales and driving forces of eruption rate variability, however, remain poorly understood. In 2018, a highly destructive eruption occurred on the lower flank of Kīlauea Volcano, Hawai‘i, where the primary vent exhibited substantial cyclic eruption rates on both short (minutes) and long (tens of hours) time scales. We used multiparameter data to show that the short cycles were driven by shallow outgassing, whereas longer cycles were pressure-driven surges in magma supply triggered by summit caldera collapse events 40 kilometers upslope. The results provide a clear link between eruption rate fluctuations and their driving processes in the magmatic system.

5 Dec 2019 at 7:41pm

Magnesium oxide at extreme temperatures and pressures studied with first-principles simulations

by François Soubiran

7 Dec 2019 at 9:00am

Oxygen Quadclusters in ${\mathrm{SiO}}_{2}$ Glass above Megabar Pressures up to 160 GPa Revealed by X-Ray Raman Scattering

by Sung Keun Lee, Yong-Hyun Kim, Yoo Soo Yi, Paul Chow, Yuming Xiao, Cheng Ji, and Guoyin Shen

X-ray Raman scattering reveals the structure of matter at extreme pressures, and so could be a useful tool for the study of planetary interiors.

5 Dec 2019 at 11:00am

Scaling Relations in Elastic Turbulence

by Victor Steinberg

We report the scaling relations between the exponents of the power-law decays of kinetic and elastic energies, pressure, as well as torque fluctuations in elastic turbulence (ET). The relations are derived by estimating that the divergent part of the elastic stress is much larger than its vortical p...

4 Dec 2019 at 11:00am

Critical Phenomena in the Temperature-Pressure-Crowding Phase Diagram of a Protein

by Andrei G. Gasic, Mayank M. Boob, Maxim B. Prigozhin, Dirar Homouz, Caleb M. Daugherty, Martin Gruebele, and Margaret S. Cheung

Proteins balance contradictory demands of folding tightly yet remaining flexible by tuning where they operate in a temperature-pressure-crowding phase diagram.

18 Nov 2019 at 11:00am

Pressure-Induced Hydrogen-Hydrogen Interaction in Metallic FeH Revealed by NMR

by Thomas Meier, Florian Trybel, Saiana Khandarkhaeva, Gerd Steinle-Neumann, Stella Chariton, Timofey Fedotenko, Sylvain Petitgirard, Michael Hanfland, Konstantin Glazyrin, Natalia Dubrovinskaia, and Leonid Dubrovinsky

Nuclear magnetic resonance experiments reveal how the electronic properties of hydrogen in iron hydride change under extreme pressure, a step toward understanding the onset of high-temperature superconductivity in metal hydrides.

17 Jul 2019 at 12:00pm

Solids, liquids, and gases under high pressure

by Ho-Kwang Mao, Xiao-Jia Chen, Yang Ding, Bing Li, and Lin Wang

The effect of adding high pressure as a control parameter in solids, liquids, and gases expands opportunities to observe unexpected novel phenomena and understand matter in extreme environments. This review on high pressure science highlights subjects ranging from quantum criticality to Earth science. State-of-the-art experimental methods at megabar pressures are also discussed. The proliferation of pressure-induced phases illustrate promising new directions for this field of research.

20 Mar 2018 at 11:00am

Colloquium: High pressure and road to room temperature superconductivity

by Lev P. Gor’kov and Vladimir Z. Kresin

Even after three decades of development, high-temperature superconductivity remains one of the most challenging theoretical and experimental areas in condensed matter physics. In this Colloquium some new discoveries in this area are reviewed and possible routes toward much higher transition temperatures are analyzed.

9 Jan 2018 at 11:00am

Effect of chemical and hydrostatic pressure on the coupled magnetostructural transition of Ni-Mn-In Heusler alloys

by P. Devi, C. Salazar Mejía, L. Caron, Sanjay Singh, M. Nicklas, and C. Felser

Ni-Mn-In magnetic shape-memory Heusler alloys exhibit generally a large thermal hysteresis at their first-order martensitic phase transition which hinders a technological application in magnetic refrigeration. By optimizing the Cu content in ${\mathrm{Ni}}_{2}{\mathrm{Cu}}_{x}{\mathrm{Mn}}_{1.4−x}{\...

10 Dec 2019 at 11:00am

Ab initio exploration of post-PPV transitions in low-pressure analogs of ${\mathrm{MgSiO}}_{3}$

by Koichiro Umemoto and Renata M. Wentzcovitch

Here, we present an ab initio investigation of the pressure-induced behavior of ${\mathrm{MgGeO}}_{3}$ and ${\mathrm{NaMgF}}_{3}$ perovskite (PV), traditional low-pressure analogs (LPAs) of ${\mathrm{MgSiO}}_{3}$ PV. The latter is an exceedingly important system in planetary sciences displaying nove...

3 Dec 2019 at 11:00am

Solubility of deuterium and hydrogen in fcc iron at high pressures and temperatures

by Vladimir E. Antonov, Vladislav M. Gurev, Valery I. Kulakov, Mikhail A. Kuzovnikov, Ilia A. Sholin, and Victoria Y. Zuykova

An isobar $x(T)$ of deuterium solubility in iron is constructed at $P=6.3\phantom{\rule{0.16em}{0ex}}\mathrm{GPa}$ and $100≤T≤800{\phantom{\rule{0.16em}{0ex}}}^{∘}\mathrm{C}$ based on the results of thermal desorption analysis of $\mathrm{Fe}{\mathrm{D}}_{x}$ samples produced by quenching under high...

18 Nov 2019 at 11:00am

Superconductivity in tin selenide under pressure

by Giovanni Marini, Paolo Barone, Antonio Sanna, Cesare Tresca, Lara Benfatto, and Gianni Profeta

Tin selenide is a layered material that captured the interest of the scientific community for its stunning thermoelectric properties and fascinating phase transitions under pressure. Recently, an experimental study revealed the existence of a topological and superconducting phase in its pressure-sta...

14 Nov 2019 at 11:00am

Structure of liquid ammonia at high pressures and temperatures

by Jean-Antoine Queyroux, Sandra Ninet, Gunnar Weck, Gaston Garbarino, Mohamed Mezouar, and Frédéric Datchi

The structure of liquid ammonia (${\mathrm{NH}}_{3}$) is investigated from 1 to 6.3 GPa and up to 800 K by means of synchrotron x-ray diffraction (XRD) and ab initio molecular dynamics (AIMD) simulations. The XRD data are used to extract the molecular structure factor ${S}_{\mathrm{mol}}(Q)$, pair d...

6 Dec 2019 at 11:00am

Resistivity, Seebeck coefficient, and thermal conductivity of platinum at high pressure and temperature

by Hitoshi Gomi (五味斎) and Takashi Yoshino (芳野極)

Platinum (Pt) is one of the most widely used functional materials for high-pressure and high-temperature experiments. Despite the crucial importance of its transport properties, both experimental and theoretical studies are very limited. In this study, we conducted density functional theory calculat...

5 Dec 2019 at 11:00am

Pressure-induced polymorphism in ${\mathrm{SrB}}_{6}$ and deformation mechanisms of covalent networks

by Li Zhu, Gustav M. Borstad, R. E. Cohen, and Timothy A. Strobel

We study the high-pressure structures of ${\mathrm{SrB}}_{6}$ up to 200 GPa using first-principles structure prediction calculations and high-pressure x-ray diffraction experiments. The computations show that the ambient-pressure cubic phase transforms to an orthorhombic structure $(Cmmm)$ at 48 GPa...

4 Dec 2019 at 11:00am

Density of amorphous $\mathrm{Ge}{\mathrm{O}}_{2}$ to 133 GPa with possible pyritelike structure and stiffness at high pressure

by Sylvain Petitgirard, Georg Spiekermann, Konstantin Glazyrin, Jan Garrevoet, and Motohiko Murakami

Germanium oxide is a prototype network-forming oxide with pressure-induced structural changes similar to those found in crystals and amorphous silicate oxides at high pressure. Studying density and coordination changes in amorphous $\mathrm{Ge}{\mathrm{O}}_{2}$ allows for insight into structural cha...

4 Dec 2019 at 11:00am

Development of a technique for high pressure neutron diffraction at 40 GPa with a Paris-Edinburgh press

by T. Hattori

4 Jun 2019 at 6:21am

Modified Bridgman anvils for high pressure synthesis and neutron scattering

by Bianca Haberl

17 Jun 2019 at 8:18am

Ultrahigh pressure equation of state of tantalum to 310 GPa

by Kaleb C. Burrage

11 Jul 2019 at 8:28am

In-situ X-ray diffraction study on β-CrOOH at high pressure and high-temperature

by Chikara Shito