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).

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
Piling on the pressures to ecosystems
by Manning, P.
14 Nov 2019 at 7:40pm
The role of multiple global change factors in driving soil functions and microbial biodiversity
by Rillig, M. C., Ryo, M., Lehmann, A., Aguilar-Trigueros, C. A., Buchert, S., Wulf, A., Iwasaki, A., Roy, J., Yang, G.

Soils underpin terrestrial ecosystem functions, but they face numerous anthropogenic pressures. Despite their crucial ecological role, we know little about how soils react to more than two environmental factors at a time. Here, we show experimentally that increasing the number of simultaneous global change factors (up to 10) caused increasing directional changes in soil properties, soil processes, and microbial communities, though there was greater uncertainty in predicting the magnitude of change. Our study provides a blueprint for addressing multifactor change with an efficient, broadly applicable experimental design for studying the impacts of global environmental change.

14 Nov 2019 at 7:40pm
A global-level assessment of the effectiveness of protected areas at resisting anthropogenic pressures [Environmental Sciences]
by Jonas Geldmann, Andrea Manica, Neil D. Burgess, Lauren Coad, Andrew Balmford
One-sixth of the global terrestrial surface now falls within protected areas (PAs), making it essential to understand how far they mitigate the increasing pressures on nature which characterize the Anthropocene. In by far the largest analysis of this question to date and not restricted to forested PAs, we compiled data...
12 Nov 2019 at 6:01pm
Is CH3NC isomerization an intrinsic non-RRKM unimolecular reaction?
by Bhumika Jayee
The Journal of Chemical Physics, Volume 151, Issue 18, November 2019.
Direct dynamics simulations, using B3LYP/6-311++G(2d,2p) theory, were used to study the unimolecular and intramolecular dynamics of vibrationally excited CH3NC. Microcanonical ensembles of CH3NC, excited with 150, 120, and 100 kcal/mol of vibrational energy, isomerized to CH3CN nonexponentially, indicative of intrinsic non-Rice-Ramsperger-Kassel-Marcus (RRKM) dynamics. The distribution of surviving CH3NC molecules vs time, i.e., N(t)/N(0), was described by two separate functions, valid above and below a time limit, a single exponential for the former and a biexponential for the latter. The dynamics for the short-time component are consistent with a separable phase space model. The importance of this component decreases with vibrational energy and may be unimportant for energies relevant to experimental studies of CH3NC isomerization. Classical power spectra calculated for vibrationally excited CH3NC, at the experimental average energy of isomerizing molecules, show that the intramolecular dynamics of CH3NC are not chaotic and the C—N≡C and CH3 units are weakly coupled. The biexponential N(t)/N(0) at 100 kcal/mol is used as a model to study CH3NC → CH3CN isomerization with biexponential dynamics. The Hinshelwood-Lindemann rate constant kuni(ω,E) found from the biexponential N(t)/N(0) agrees with the Hinshelwood-Lindemann-RRKM kuni(ω,E) at the high and low pressure limits, but is lower at intermediate pressures. As found from previous work [S. Malpathak and W. L. Hase, J. Phys. Chem. A 123, 1923 (2019)], the two kuni(ω,E) curves may be brought into agreement by scaling ω in the Hinshelwood-Lindemann-RRKM kuni(ω,E) by a collisional energy transfer efficiency factor βc. The interplay between the value of βc, for the actual intermolecular energy transfer, and the ways the treatment of the rotational quantum number K and nonexponential unimolecular dynamics affect βc suggests that the ability to fit an experimental kuni(ω,T) with Hinshelwood-Lindemann-RRKM theory does not identify a unimolecular reactant as an intrinsic RRKM molecule.
14 Nov 2019 at 2:58am
Pressure densified 1,3,5-tri(1-naphthyl)benzene glass. I. Volume recovery and physical aging
by A. P. Holt
The Journal of Chemical Physics, Volume 151, Issue 18, November 2019.
The effects of pressure densification on 1,3,5-tri(1-naphthyl)benzene (TNB) are assessed from volumetric and calorimetric measurements. The pressure densified glass (PDG) has higher density than conventional glass (CG), but unlike ultrastable TNB glass prepared using vapor deposition which also has elevated density, TNB PDG exhibits higher enthalpy and lower thermal stability than when formed at ambient pressure. PDG also exhibits anomalous physical aging. Rather than evolving monotonically toward the equilibrium density, there is an overshoot to a lower density state. Only when the density of the PDG becomes equivalent to the corresponding CG does the density begin a slow approach toward equilibrium.
11 Nov 2019 at 3:28am
Low temperature protein refolding suggested by molecular simulation
by Daniel J. Kozuch
The Journal of Chemical Physics, Volume 151, Issue 18, November 2019.
The function of critical biological materials, such as proteins, is intrinsically tied to their structure, and this structure is in turn heavily dependent on the properties of the solvent, most commonly water or dilute aqueous solutions. As water is known to exhibit anomalous properties, especially at supercooled temperatures, it is natural to ask how these properties might impact the thermodynamics of protein folding. To investigate this question, we use molecular simulation to explore the behavior of a model miniprotein, Trp-cage, as low as 70 K below the freezing point of the solvent at ambient pressure. Surprisingly, we find that while the expected cold denaturation of the protein is observed at moderate supercooling, further cooling to more than 55 K below the freezing point leads to cold refolding of the protein. Structural and hydrogen bonding analysis suggests that this refolding is driven by the desolvation of the protein’s hydrophobic core, likely related to the pronounced decrease in density at this temperature. Beyond their intrinsic fundamental interest, these results have implications for cryomicroscopy and cryopreservation, where biological materials are often transiently subjected to these extreme conditions.
11 Nov 2019 at 3:28am
Resymmetrizing Broken Symmetry with Hydraulic Pressure
by Ke Huang, Pengjie Wang, L. N. Pfeiffer, K. W. West, K. W. Baldwin, Yang Liu, and Xi Lin
Author(s): Ke Huang, Pengjie Wang, L. N. Pfeiffer, K. W. West, K. W. Baldwin, Yang Liu, and Xi Lin

Recent progress in condensed matter physics, such as for graphene, topological insulators, and Weyl semimetals, often originate from the specific topological symmetries of their lattice structures. Quantum states with different degrees of freedom, e.g., spin, valley, layer, etc., arise from these sy...

[Phys. Rev. Lett. 123, 206602] Published Fri Nov 15, 2019
15 Nov 2019 at 11:00am
Extreme Hardening of Pb at High Pressure and Strain Rate
by A. Krygier, P. D. Powell, J. M. McNaney, C. M. Huntington, S. T. Prisbrey, B. A. Remington, R. E. Rudd, D. C. Swift, C. E. Wehrenberg, A. Arsenlis, H.-S. Park, P. Graham, E. Gumbrell, M. P. Hill, A. J. Comley, and S. D. Rothman
Author(s): A. Krygier, P. D. Powell, J. M. McNaney, C. M. Huntington, S. T. Prisbrey, B. A. Remington, R. E. Rudd, D. C. Swift, C. E. Wehrenberg, A. Arsenlis, H.-S. Park, P. Graham, E. Gumbrell, M. P. Hill, A. J. Comley, and S. D. Rothman

When rapidly compressed to planetary-core pressures, lead—a soft metal—becomes 10 times stronger than high-grade steel.

[Phys. Rev. Lett. 123, 205701] Published Mon Nov 11, 2019
11 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
Author(s): 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.

[Phys. Rev. X 9, 031008] Published Wed Jul 17, 2019
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
Author(s): 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.

[Rev. Mod. Phys. 90, 015007] Published Tue Mar 20, 2018
20 Mar 2018 at 11:00am
Colloquium: High pressure and road to room temperature superconductivity
by Lev P. Gor’kov and Vladimir Z. Kresin
Author(s): 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.

[Rev. Mod. Phys. 90, 011001] Published Tue Jan 09, 2018
9 Jan 2018 at 11:00am
Superconductivity in tin selenide under pressure
by Giovanni Marini, Paolo Barone, Antonio Sanna, Cesare Tresca, Lara Benfatto, and Gianni Profeta
Author(s): 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...

[Phys. Rev. Materials 3, 114803] Published Thu Nov 14, 2019
14 Nov 2019 at 11:00am
Effect of Ge substitution on magnetic properties in the itinerant chiral magnet MnSi
by Seno Aji, Hidesato Ishida, Daisuke Okuyama, Kazuhiro Nawa, Tao Hong, and Taku J. Sato
Author(s): Seno Aji, Hidesato Ishida, Daisuke Okuyama, Kazuhiro Nawa, Tao Hong, and Taku J. Sato

We have investigated the effect of Ge substitution on the magnetic ordering in the B20 itinerant chiral magnet MnSi prepared by melting and annealing under ambient pressure. From a metallurgical survey, the solubility limit of Ge was found to be $x=0.144(5)$ with annealing temperature ${T}_{\mathrm{... [Phys. Rev. Materials 3, 104408] Published Mon Oct 14, 2019 14 Oct 2019 at 12:00pm Determining surface phase diagrams including anharmonic effects by Yuanyuan Zhou, Matthias Scheffler, and Luca M. Ghiringhelli Author(s): Yuanyuan Zhou, Matthias Scheffler, and Luca M. Ghiringhelli A prerequisite for analyzing and understanding the electronic properties and the function of surfaces is the detailed knowledge of their structure under realistic conditions. The authors have developed a replica-exchange grand-canonical algorithm, enabling the unbiased calculation of pressure-temperature phase diagrams of surfaces or clusters in reactive atmospheres including anharmonic effects. Moreover, the multicanonical sampling yields the p-T dependence (map) of all equilibrium observables, such as the radial distribution function, which can be measured within the given model Hamiltonian. [Phys. Rev. B 100, 174106] Published Thu Nov 14, 2019 14 Nov 2019 at 11:00am Ab initio study of metallic aluminum hydrides at high pressures by Kazutaka Abe Author(s): Kazutaka Abe Metallic phases of${\mathrm{Al}}_{2}\mathrm{H}$and AlH at megabar pressures are predicted to be possible by using ab initio density functional calculations. The${\mathrm{Al}}_{2}\mathrm{H}$phase is stabilized above 155 GPa, where several candidate structures are quite competitive; the structural... [Phys. Rev. B 100, 174105] Published Wed Nov 13, 2019 13 Nov 2019 at 11:00am High-pressure melting line of helium from ab initio calculations by Martin Preising and Ronald Redmer Author(s): Martin Preising and Ronald Redmer We applied two-phase simulations to directly calculate the high-pressure melting line of helium from 425 to 10 000 K and from 15 GPa to 35 TPa by using molecular dynamics based on density-functional theory. The implementation of the two-phase simulation method and the relaxation of the simulation to... [Phys. Rev. B 100, 184107] Published Wed Nov 13, 2019 13 Nov 2019 at 11:00am Praseodymium polyhydrides synthesized at high temperatures and pressures by Miriam Peña-Alvarez, Jack Binns, Andreas Hermann, Liam C. Kelsall, Philip Dalladay-Simpson, Eugene Gregoryanz, and Ross T. Howie Author(s): Miriam Peña-Alvarez, Jack Binns, Andreas Hermann, Liam C. Kelsall, Philip Dalladay-Simpson, Eugene Gregoryanz, and Ross T. Howie Rare earth element polyhydrides have been predicted to exhibit high-${T}_{c}$superconductivity at extreme compressions. Through a series of in situ high-pressure high-temperature x-ray powder diffraction experiments combined with density functional theory calculations, we report the emergence of po... [Phys. Rev. B 100, 184109] Published Wed Nov 13, 2019 13 Nov 2019 at 11:00am Compression of liquid Ni and Co under extreme conditions explored by x-ray absorption spectroscopy by Silvia Boccato, Raffaella Torchio, Paola D'Angelo, Angela Trapananti, Innokenty Kantor, Vanina Recoules, Simone Anzellini, Guillaume Morard, Tetsuo Irifune, and Sakura Pascarelli Author(s): Silvia Boccato, Raffaella Torchio, Paola D'Angelo, Angela Trapananti, Innokenty Kantor, Vanina Recoules, Simone Anzellini, Guillaume Morard, Tetsuo Irifune, and Sakura Pascarelli The compression of liquid nickel and cobalt has been investigated up to 102 and 83 GPa, respectively, by x-ray absorption spectroscopy at the Ni and Co$K$edges, using laser-heated diamond anvil cell. A shortening of about 8%–10% of the metal bond distances is observed in the pressure range conside... [Phys. Rev. B 100, 180101(R)] Published Fri Nov 08, 2019 8 Nov 2019 at 11:00am Contrasting pressure evolution of$f$-electron hybridized states in${\mathrm{CeRhIn}}_{5}$and${\mathrm{YbNi}}_{3}{\mathrm{Ga}}_{9}$: An optical conductivity study by H. Okamura, A. Takigawa, T. Yamasaki, E. D. Bauer, S. Ohara, Y. Ikemoto, and T. Moriwaki Author(s): H. Okamura, A. Takigawa, T. Yamasaki, E. D. Bauer, S. Ohara, Y. Ikemoto, and T. Moriwaki Optical conductivity$[σ(ω)]$of${\mathrm{CeRhIn}}_{5}$and${\mathrm{YbNi}}_{3}{\mathrm{Ga}}_{9}$have been measured at external pressures to 10 GPa and at low temperatures to 6 K. Regarding${\mathrm{CeRhIn}}_{5}$, at ambient pressure the main feature in$σ(ω)\$ is a Drude peak due to free carrier...

[Phys. Rev. B 100, 195112] Published Fri Nov 08, 2019
8 Nov 2019 at 11:00am
Development of a technique for high pressure neutron diffraction at 40 GPa with a Paris-Edinburgh press
by T. Hattori
Volume 39, Issue 3, September 2019, Page 417-425
.

4 Jun 2019 at 6:21am
Modified Bridgman anvils for high pressure synthesis and neutron scattering
by Bianca Haberl
Volume 39, Issue 3, September 2019, Page 426-437
.

17 Jun 2019 at 8:18am
Ultrahigh pressure equation of state of tantalum to 310 GPa
by Kaleb C. Burrage
Volume 39, Issue 3, September 2019, Page 489-498
.

11 Jul 2019 at 8:28am
In-situ X-ray diffraction study on β-CrOOH at high pressure and high-temperature
by Chikara Shito
Volume 39, Issue 3, September 2019, Page 499-508
.

17 Jul 2019 at 2:46pm
Effects of high hydrostatic pressure on β-glucan content, swelling power, starch damage, and pasting properties of high-β-glucan barley flour
by Shigeaki Ueno
Volume 39, Issue 3, September 2019, Page 509-524
.

29 Mar 2019 at 1:58pm
The usage of high hydrostatic pressure (HHP) to control food-borne pathogens in hummus
by Barbara Sokołowska
Volume 39, Issue 3, September 2019, Page 525-532
.

24 Jun 2019 at 12:09pm
High pressure generation in the Kawai-type multianvil apparatus equipped with sintered diamond anvils
by D. Yamazaki
.

15 Nov 2019 at 5:19am
High pressure influence on the Diels–Alder reaction volume in the solid phase at pressure up to 7000 bar and in solution
by Dmitry A. Kornilov
.

8 Oct 2019 at 10:58am
The application of manganin wire pressure gauges in a large volume press under high-temperature conditions
by Ren Dongsheng
.

8 Oct 2019 at 10:58am
Hydrostaticity of pressure-transmitting media for high pressure infrared spectroscopy
by A. Celeste
.

20 Sep 2019 at 11:59am
Enhancing the pressure limitation in large-volume Bridgman-anvil cell used for in situ neutron diffraction
by Qiwei Hu
.

19 Sep 2019 at 1:28pm
High hydrostatic pressure processing of beetroot juice: effects on nutritional, sensory and microbiological quality
by Marta Ubeira-Iglesias
.

19 Sep 2019 at 1:24pm
Lattice distortion-induced sluggish phase transition in CoCrFeNixAl1-x (x = 0.5, 0.75) high-entropy alloys at high pressures
by Lei Liu
.

16 Aug 2019 at 12:07pm
Flatland magnets are switched under pressure

14 Nov 2019 at 6:59pm