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Off-Hugoniot loading methods for dynamic compression have been a topic of interest for many years as a means of accessing high pressures without melting a material. Simulations and an initial test experiment of a three-layer gas-gun impactor suitable for use in measuring dynamic material strength at multi-megabar pressures are described. As shown through ARES hydrocode simulations, an impactor consisting of a low-, medium-, and high-impedance material, such as TPX, Al, and Ta or Pt, can produce a quasi-isentropic loading path up to 4.6 Mbar pressure with a low homologous temperature (T/Tmelt= 0.1–0.25). These impactors can also be tailored to create a pressure drive suitable for a Lagrangian sound speed experiment. Simulated in-situ velocities were analyzed to determine the change in calculated strength due to non-uniformity in the impactor, which provides a measure of error sensitivity. An initial test of a three-layer projectile onto a flat target at 4.4 km/s impact velocity is reported. While the impactor incurred some delamination during firing, the measured sample/window interface velocity generally agrees with the simulated peak velocity and subsequent release, indicating the feasibility of this approach for measuring material strength.

Investigating how solid matter behaves at enormous pressures, such as those found in the deep interiors of giant planets, is a great experimental challenge. Over the past decade, computational predictions have revealed that compression to terapascal pressures may bring about counter-intuitive changes in the structure and bonding of solids as quantum mechanical forces grow in influence1–6. Although this behaviour has been observed at modest pressures in the highly compressible light alkali metals7,8, it has not been established whether it is commonplace among high-pressure solids more broadly. We used shaped laser pulses at the National Ignition Facility to compress elemental Mg up to 1.3 TPa, which is approximately four times the pressure at the Earth’s core. By directly probing the crystal structure using nanosecond-duration X-ray diffraction, we found that Mg changes its crystal structure several times with non-close-packed phases emerging at the highest pressures. Our results demonstrate that phase transformations of extremely condensed matter, previously only accessible through theoretical calculations, can now be experimentally explored.

The phase behaviour of warm dense hydrogen−helium (H−He) mixtures affects our understanding of the evolution of Jupiter and Saturn and their interior structures1,2. For example, precipitation of He from a H−He atmosphere at about 1−10 megabar and a few thousand kelvin has been invoked to explain both the excess luminosity of Saturn1,3, and the depletion of He and neon (Ne) in Jupiter’s atmosphere as observed by the Galileo probe4,5. But despite its importance, H−He phase behaviour under relevant planetary conditions remains poorly constrained because it is challenging to determine computationally and because the extremes of temperature and pressure are difficult to reach experimentally. Here we report that appropriate temperatures and pressures can be reached through laser-driven shock compression of H2−He samples that have been pre-compressed in diamond-anvil cells. This allows us to probe the properties of H−He mixtures under Jovian interior conditions, revealing a region of immiscibility along the Hugoniot. A clear discontinuous change in sample reflectivity indicates that this region ends above 150 gigapascals at 10,200 kelvin and that a more subtle reflectivity change occurs above 93 gigapascals at 4,700 kelvin. Considering pressure–temperature profiles for Jupiter, these experimental immiscibility constraints for a near-protosolar mixture suggest that H−He phase separation affects a large fraction—we estimate about 15 per cent of the radius—of Jupiter’s interior. This finding provides microphysical support for Jupiter models that invoke a layered interior to explain Juno and Galileo spacecraft observations1,4,6–8.

The discovery of an extraordinary number of extrasolar planets, characterized by an unexpected variety of sizes, masses and orbits, challenges our understanding of the formation and evolution of the planets in the Solar System and the perception of the Earth as the prototypical habitable world. Many exoplanets appear to be rocky and yet more massive than the Earth, with expected pressures and temperatures of hundreds of gigapascal and thousands of Kelvin in their deep interiors. At these conditions, the properties of bridgmanite and ferropericlase, expected to dominate their mantles, are largely unconstrained, limiting our knowledge of their interior structure. Here we used nano-second X-ray diffraction and dynamic compression to experimentally investigate the atomic structure and density of iron oxide (FeO), one of the end-members of the (Mg,Fe)O ferropericlase solid solution, up to 700 GPa, a pressure exceeding the core–mantle boundary of a 5 Earth masses planet. Our data document the stability of the high-pressure cesium-chloride B2 structure above 300 GPa, well below the pressure required for magnesium oxide (MgO) to adopt the same phase. These observations, complemented by the calculation of the binary MgO–FeO phase diagram, reveal complex stratification and rheology inside large terrestrial exoplanets.

Carbon is the fourth-most prevalent element in the Universe and essential for all known life. In the elemental form it is found in multiple allotropes, including graphite, diamond and fullerenes, and it has long been predicted that even more structures can exist at pressures greater than those at Earth’s core1–3. Several phases have been predicted to exist in the multi-terapascal regime, which is important for accurate modelling of the interiors of carbon-rich exoplanets4,5. By compressing solid carbon to 2 terapascals (20 million atmospheres; more than five times the pressure at Earth’s core) using ramp-shaped laser pulses and simultaneously measuring nanosecond-duration time-resolved X-ray diffraction, we found that solid carbon retains the diamond structure far beyond its regime of predicted stability. The results confirm predictions that the strength of the tetrahedral molecular orbital bonds in diamond persists under enormous pressure, resulting in large energy barriers that hinder conversion to more-stable high-pressure allotropes1,2, just as graphite formation from metastable diamond is kinetically hindered at atmospheric pressure. This work nearly doubles the highest pressure at which X-ray diffraction has been recorded on any material.

We demonstrate the recently developed technique of laser driven isentropic compression (ICE) for dynamically compressing Al samples at high laoding rates close to the room temperature isentrope and up to peak stresses above 100 GPa. Upon analysis of the unloading profiles from a multi-stepped Al/LiF target a continuous path through Stress-Density space may be calculated. For materials with phase transformations ramp compression techniques reveals the location of equilibrium phase boundaries and provide information on the kinetics of the lattice re-ordering.

The objective of this study was to evaluate the effect of sire line on wean-to-finish performance, carcass characteristics, and meat pricing variables. Pigs used for this study were the progeny of a commercial Landrace x Large White female mated to one of the following sire lines: a purebred Duroc line (Line S1), or a synthetic (Line S2) or purebred Duroc line (Line S3) originating from a different genetic source. An equivalent number of pigs (n =144) were used per group, for 432 pigs placed on test. Average initial weights per line were 6.67 ± 0.24, 6.67 ± 0.24, and 6.60 ± 0.24 for lines S1, S2, and S3, respectively. At placement, 8 pigs were assigned to each pen (split sex) and blocked by line and initial BW, with 18 replicates per line. Data were analyzed at the pen level using the PROC MIXED procedure of SAS, where the effects of line, sex, and line*sex were fitted as fixed effects and replicate was fitted as a random effect. Overall, piglets from line S2 (0.403 vs 0.381; P ≤ 0.0004) and line S3 (0.402 vs 0.381; P ≤ 0.001) had improved GF compared with piglets from line S1. The ADFI was greater in piglets from line S1 relative to piglets from line S2 (2.264 vs 2.117 kg; P ≤ 0.0001) and line S3 (2.264 vs 2.159 kg; P ≤ 0.004). The ADG, HCW, dressing yield, and loin depth were not different among treatment (P > 1.00). Piglets from line S3 had greater percent lean (57.12 vs 56.29 %; P ≤ 0.0001) and better carcass grade premium ($7.07 vs 6.60; P ≤ 0.0291) relative to piglets from line S1. In conclusion, line S1 piglets had greatest ADFI, but line S2 pigs and line S3 piglets had better feed efficiency. Line S3 pigs were leaner and had better carcass grade premium.

Magnesium oxide is an important component of the Earth’s mantle and has been extensively studied at pressures and temperatures relevant to Earth. However, much less is known about the behaviour of this oxide under conditions likely to occur in extrasolar planets with masses up to 10 times that of Earth, termed super-Earths, where pressures can exceed 1,000?GPa (10 million atmospheres). Magnesium oxide is expected to change from a rocksalt crystal structure (B1) to a caesium chloride (B2) structure at pressures of about 400–600?GPa (refs , ). Whereas no structural transformation was observed in static compression experiments up to 250?GPa (ref. ), evidence for a solid–solid phase transition was obtained in shockwave experiments above 400?GPa and 9,000?K (ref. ), albeit no structural measurements were made. As a result, the properties and the structure of MgO under conditions relevant to super-Earths and large planets are unknown. Here we present dynamic X-ray diffraction measurements of ramp-compressed magnesium oxide. We show that a solid–solid phase transition, consistent with a transformation to the B2 structure, occurs near 600?GPa. On further compression, this structure remains stable to 900?GPa. Our results provide an experimental benchmark to the equations of state and transition pressure of magnesium oxide, and may help constrain mantle viscosity and convection in the deep mantle of extrasolar super-Earths.

A first set of shock propagation, laser-plasma interaction, hohlraum energetics and hydrodynamic experiments have been performed using the first 4 beams of the National Ignition Facility (NIF), in support of indirect drive Inertial Confinement Fusion (ICF) and High Energy Density Physics.

We demonstrate the recently developed technique of laser driven isentropic compression (ICE) for dynamically compressing Al samples at high laoding rates close to the room temperature isentrope and up to peak stresses above 100?GPa. Upon analysis of the unloading profiles from a multi-stepped Al/LiF target a continuous path through Stress-Density space may be calculated. For materials with phase transformations ramp compression techniques reveals the location of equilibrium phase boundaries and provide information on the kinetics of the lattice re-ordering.

When analysing patterns, our goals are (i) to find structure in the presence of noise, (ii) to decompose the observed structure into sub-components, and (iii) to use the components for pattern completion. Here, a novel loop architecture is introduced to perform these tasks in an unsupervised manner. The architecture combines sparse code shrinkage with non-negative matrix factorisation, and blends their favourable properties: sparse code shrinkage aims to remove Gaussian noise in a robust fashion; non-negative matrix factorisation extracts substructures from the noise filtered inputs. The loop architecture performs robust pattern completion when organised into a two-layered hierarchy. We demonstrate the power of the proposed architecture on the so-called ‘bar-problem’ and on the FERETfacial database.

A study of the effects of conjugated linoleic acid (CLA) on the belly firmness and fatty acid composition of genetically lean pigs was conducted. From 75 to 120 kg live weight, 30 gilts were allowed ad libitum access to a corn-soybean meal diet supplemented with either 1% CLA oil (CLA-60) or 1% sunflower oil (SFO) or were fed the sunflower oil-supplemented diet restricted to the amount consumed by pigs fed the CLA-60 diet (RSFO). Conjugated linoleic acid oil consists of 60% positional and geometric isomers of CLA. Pigs fed SFO exhibited higher average daily gains (0.98 vs 0.80 kg/d, P< 0.01) than RSFO-fed pigs, but there were no effects of dietary treatment on feed intake or feed efficiency. Dietary treatment did not affect (P> 0.05) backfat thickness or longissimus muscle area. Bellies of gilts fed CLA-60 were subjectively evaluated to be firmer (2.91 vs 2.43 or 2.07 ± 0.13, P< 0.01) than those of SFO- or RSFO-fed gilts, respectively. The longissimus muscle of gilts fed CLA-60 contained more saturated fatty acids (39.77 vs. 36.04 or 36.73 ± 0.74%, P< 0.001) and less unsaturated fatty acids (60.23 vs 63.96 or 63.27 ± 0.74%, P< 0.001) than that of gilts fed SFO or RSFO, respectively. The belly fat of gilts fed CLA-60 contained more saturated fatty acids (44.45 vs. 37.50 or 36.60 ± 0.46%, P< 0.001) and less unsaturated fatty acids (54.78 vs. 61.75 or 62.47 ± 0.46%, P< 0.001), resulting in lower iodine values (57.69 vs 66.37 or 65.62 ± 0.91, P< 0.001) than that of gilts fed SFO or RSFO, respectively. Gilts fed CLA-60 accumulated more CLA in the longissimus muscle (0.55 vs 0.09 or 0.09 ± 0.03%, P< 0.01) and belly fat (1.56 vs. 0.13 or 0.13 ± 0.15%, P< 0.001) than did gilts fed SFO or RSFO, respectively. Dietary treatment did not affect (P> 0.05) 24-h pH, drip loss or subjective quality evaluations of the longissimus muscle. The effect of supplemental CLA to improve belly firmness is of practical significance and may provide a nutritional solution to carcass fat and belly firmness problems, thereby enhancing the overall value of extremely lean carcasses.

We present a detailed experimental and theoretical study of the vibrons in ortho-para mixed crystals of solid hydrogen and deuterium at ambient and high pressure. Experimental results were obtained at ambient pressure and T=6–7 K (e.g., for hydrogen samples having ortho fractions of 19–62%) using high-resolution Fabry-Perot techniques, and at high pressure and T=77 K (e.g., hydrogen 50–50% ortho-para samples) using dispersive spectrographic techniques with diamond-anvil cells. The numerical calculations are based on the James and Van Kranendonk theory, and were performed by exactly diagonalizing the Hamiltonian for a large supercell of randomly placed molecular “species” on a crystalline lattice. Overall, excellent agreement between theory and experiment is obtained. The calculations show that disorder leads to Anderson localized vibrons for many of the pressures and concentrations studied experimentally and that a substantial portion of the Raman intensity is derived from these localized vibrons. We also calculate the species characteristics of the individual Raman peaks, the results of which suggest an explanation for the previously noted disagreement between experimental high-pressure results and the predictions of the van Kranendonk theory. Specifically, our analysis indicates that the higher frequency peak is associated with anisotropic scattering arising from partial alignment of J=1 angular momenta with respect to the crystallographic axes. Finally, our calculations show that the observed doublet structure in the lower frequency Raman peak for deuterium at low para (J=1) concentrations is well represented by added (para-molecule) diagonal terms in the van Kranendonk Hamiltonian that are plausibly associated with electric quadrupole-quadrupole interactions.

Monocyte antibody-dependent cell-mediated cytotoxicity (ADCC) was compared to instrinsic cyclic-adenosine-monophosphate (cAMP) levels in 14 patients with systemic sclerosis. Depressed monocyte cytotoxicity was oberserved. Elevated cAMP levels (2–5 times) in resting monocytes were found in 5 patients; the rest had normal cAMP values. Monocyte ADCC was inversely correlated to cellular cAMP content (r=-0.6659, P<0.02). Scleroderma patients with high basal cAMP levels showed impaired responses to beta-adrenergic stimulation but not to prostaglandin E (PGE1) and histamine. Patients with normal basal cAMP levels showed no defect in beta-adrenergic responses. No close correlation between monocyte abnormality and clinical state was found.

There is still controversy as to what constitutes the optimal therapy for acute and delayed chemotherapy-induced emesis and nausea. We conducted a three-armed randomized multi-centre study in 193 chemotherapy-naive patients receiving highly emetogenic chemotherapy inducing both acute and delayed symptoms (cisplatin ≥50 mg/m2, carboplatin ≥300 mg/m2, cyclophosphamide ≥750 mg/m2, ifosfamide ≥1.5 g/m2on day 1). Group A: 1×5 mg tropisetron i.v. on day 1+2, then 10 mg p.o. (oral dose now recommended: 5 mg); group B: tropisetron as for A+dexamethasone, 20 mg i.v., on days 1+2, then 4 mg i.v./p.o.; group C: tropisetron as for A+metoclopramide, 20 mg i.v.+2×10 mg p.o. on day 1, then 3×10 mg p.o. Treatment was continued for at least 2 days after the end of chemotherapy. Tropisetron+dexamethasone was significantly superior to tropisetron alone both for acute (P=0.0064) and delayed (P=0.0053) emesis. Complete control of acute and delayed emesis (nausea) was achieved in 80% (75%) and 53% (46%) in group A, 97% (90%) and 80% (58%) in group B, and 86% (80%) and 49% (45%) in group C. Patients completely asymptomatic during the whole cycle accounted for 26% of those in group A, 49% in group B and 28% in group C. The most frequent adverse events were constipation (16.6%), headache (7.3%) and tiredness (7.3%). Once-daily tropisetron+dexamethasone over several days is well tolerated and is a simple means of achieving further significant improvement in the efficacy of tropisetron against acute and delayed symptoms.

Ohne Zusammenfassung:

Zusammenfassung Die Absorptionsspektren von dünnen Schichten aus mikrokristallinem Silberbromid und Silberchlorid werden nach einer photographischen Methode untersucht, die mit sehr geringen Lichtmengen arbeitet.

Zusammenfassung 1.Die Absorptionsverhältnisse von geschmolzenem und dispersem Bromsilber, von klaren und dispersen Gelatinen, sowie von zwei Trockenplattentypen wurden nach drei verschiedenen Methoden für sechs Spektralbereiche untersucht. Die wahre Bromsilberabsorption wurde unter Berücksichtigung der Eigenschaften von Bromsilber und Gelatine aus diesen Messungen berechnet.2.Es wurde eine an das Volhardsche maßanalytische Silberbestimmungsverfahren anschließende Methode zur Bestimmung des metallischen Silbers in belichteten Bromsilbergelatineschichten ausgearbeitet. Die Silberverluste beim Fixieren einer Platte unter verschiedenen Bedingungen wurden untersucht.3.Bei dem Vergleich der Anzahl absorbierterhv mit der Anzahl analytisch bestimmter Silberatome zeigt sich für die Wellenlängen 436, 405 und 365 mµ, daß pro Quant ein Bromsilbermolekül zerlegt wird.

Zusammenfassung In der nachfolgenden Untersuchung werden frühere Messungen über den gleichen Gegenstand auf einige weitere Emulsionsarten ausgedehnt. Der frühere Befund wird bestätigt und gleichzeitig auf einen Widerspruch unserer Beobachtungen mit denen von March hingewiesen.

Zusammenfassung Die Zersetzung des Bromsilbers photographischer Filme unter der Einwirkung von Röntgenstrahlen wird im Gebiete starker Bestrahlung untersucht. Aus der Energie der Röntgenstrahlung, ihrer Absorption in der Schicht und der gebildeten Silbermenge wird das Quantenäquivalent bestimmt. Im Gebiete kleiner Strahlenmengen (photographisches Gebiet) wird die Anzahl der entwickelbaren Körner mit der Anzahl absorbierter hv Röntgenstrahlung verglichen. Im Anschluß an diese Untersuchungen wird die Fluoreszenzausbeute eines Verstärkerschirmes von Calciumwolframat bei der Umwandlung von Röntgenstrahlen in blaues Licht geschätzt.

Die Versuche beschäftigen sich mit photographischen Emulsionen von Silberazid (AgN3) — oft verglichen mit solchen von AgCl —, weil diese endotherme Substanz keine Rückvereinigung der photolytisch getrennten Komponenten zeigen kann. Es wird berichtet, welches die günstigsten Entwicklungsbedingungen der auf Glas und Papier vergossenen AgN3-Emulsionen sind, und anschließend wird ein Empfindlichkeitsvergleich mit AgCl bei Beobachtung der Korngrößen unter dem Elektronenmikroskop durchgeführt. AgN3-Schichten zeigen bedingt Solarisation; dem Herschel-Effekt überlagert sich eine überraschend weit im Rot gelegene Empfindlichkeit der AgN3-Schichten (Maximum bei 650 mμ), wenn sich in ihnen bereits eine geringe Silbermenge durch thermische Zersetzung gebildet hat. — Die Quantenausbeute der Strahlung von 365 mμ beträgt für AgN3φ = 0,1, für AgCl φ = 0,7 bis 1,02. Der unerwartet niedrige φ-Wert der endothermen Substanz wird diskutiert.