Dynamic compression of water to conditions in ice giant interiors.

Recent discoveries of water-rich Neptune-like exoplanets require a more detailed understanding of the phase diagram of HO at pressure-temperature conditions relevant to their planetary interiors. The unusual non-dipolar magnetic fields of ice giant planets, produced by convecting liquid ionic water, are influenced by exotic high-pressure states of HO-yet the structure of ice in this state is challenging to determine experimentally. Here we present X-ray diffraction evidence of a body-centered cubic (BCC) structured HO ice at 200 GPa and ~ 5000 K, deemed ice XIX, using the X-ray Free Electron Laser of the Linac Coherent Light Source to probe the structure of the oxygen sub-lattice during dynamic compression.

Femtosecond Visualization of hcp-Iron Strength and Plasticity under Shock Compression.

Iron is a key constituent of planets and an important technological material. Here, we combine in situ ultrafast x-ray diffraction with laser-induced shock compression experiments on Fe up to 187(10) GPa and 4070(285) K at 10^{8}  s^{-1} in strain rate to study the plasticity of hexagonal-close-packed (hcp)-Fe under extreme loading states. {101[over ¯]2} deformation twinning controls the polycrystalline Fe microstructures and occurs within 1 ns, highlighting the fundamental role of twinning in hcp polycrystals deformation at high strain rates.

Leukocyte telomere length is inversely associated with a metabolic risk score in Mesoamerican children.

Objective: Leukocyte telomere length (LTL) may be involved in the etiology of the metabolic syndrome (MetS). We examined the associations of LTL with MetS and its components among Mesoamerican children and their adult parents, in a region where MetS prevalence is high.

Methods: We conducted a cross-sectional study of 151 children aged 7-12 years and 346 parents from the capitals of Belize, Honduras, Nicaragua, Costa Rica, Panama, and Chiapas State, Mexico.

Prebirth Household Challenges To Predict Adverse Childhood Experiences Score by Age 3.

Objectives: With this study, we seek to understand the relationship between prebirth household challenges and the child's adverse childhood experiences (ACEs) score by age 3 in a statewide-representative birth cohort to inform primary prevention strategies.

Methods: We used a longitudinally linked data set from the Alaska 2009-2011 Pregnancy Risk Assessment Monitoring System, its 3-year follow-up survey, and multiple administrative data sources. Using this linked data set, we predicted an expanded ACEs score by age 3 using maternal reported prebirth household challenges.

ATiO (A = Dy, Gd, Er, Yb) at High Pressure.

The structural evolution of lanthanide ATiO (A = Dy, Gd, Yb, Er) at high pressure is investigated using synchrotron X-ray diffraction. The effects of A-site cation size and of the initial structure are systematically examined by varying the composition of the isostructural lanthanide titanates and the structure of dysprosium titanate polymorphs (orthorhombic, hexagonal, and cubic), respectively. All samples undergo irreversible high-pressure phase transformations, but with different onset pressures depending on the initial structure.

Pressure-induced structural modifications of rare-earth hafnate pyrochlore.

Complex oxides with the pyrochlore (ABO) and defect-fluorite ((A,B)O) structure-types undergo structural transformations under high-pressure. Rare-earth hafnates (AHfO) form the pyrochlore structure for A  =  La-Tb and the defect-fluorite structure for A  =  Dy-Lu. High-pressure transformations in AHfO pyrochlore (A  =  Sm, Eu, Gd) and defect-fluorite (A  =  Dy, Y, Yb) were investigated up to ~50 GPa and characterized by in situ Raman spectroscopy and synchrotron x-ray diffraction (XRD).

High pressure synthesis of a hexagonal close-packed phase of the high-entropy alloy CrMnFeCoNi.

High-entropy alloys, near-equiatomic solid solutions of five or more elements, represent a new strategy for the design of materials with properties superior to those of conventional alloys. However, their phase space remains constrained, with transition metal high-entropy alloys exhibiting only face- or body-centered cubic structures. Here, we report the high-pressure synthesis of a hexagonal close-packed phase of the prototypical high-entropy alloy CrMnFeCoNi.

Strain engineered pyrochlore at high pressure.

Strain engineering is a promising method for next-generation materials processing techniques. Here, we use mechanical milling and annealing followed by compression in diamond anvil cell to tailor the intrinsic and extrinsic strain in pyrochlore, DyTiO and DyZrO. Raman spectroscopy, X-ray pair distribution function analysis, and X-ray diffraction were used to characterize atomic order over short-, medium-, and long-range spatial scales, respectively, under ambient conditions.

Changes in skeletal muscle and tendon structure and function following genetic inactivation of myostatin in rats.

Myostatin is a negative regulator of skeletal muscle and tendon mass. Myostatin deficiency has been well studied in mice, but limited data are available on how myostatin regulates the structure and function of muscles and tendons of larger animals. We hypothesized that, in comparison to wild-type (MSTN(+/+) ) rats, rats in which zinc finger nucleases were used to genetically inactivate myostatin (MSTN(Δ/Δ) ) would exhibit an increase in muscle mass and total force production, a reduction in specific force, an accumulation of type II fibres and a decrease and stiffening of connective tissue.

Pulsed quantum cascade laser based hypertemporal real-time headspace measurements.

Optical cavity enhancement is a highly desirable process to make sensitive direct-absorption spectroscopic measurements of unknown substances, such as explosives, illicit material, or other species of interest. This paper reports advancements in the development of real-time cavity ringdown spectroscopy over a wide-bandwidth, with the aim to make headspace measurements of molecules at trace levels. We report results of two pulsed quantum cascade systems operating between (1200 to 1320)cm(-1) and (1316 to 1613)cm(-1) that measure the headspace of nitromethane, acetonitrile, acetone, and nitroglycerin, where the spectra are obtained in less than four seconds and contain at least 150,000 spectral wavelength datapoints.