Search

Laser-driven dynamic compression experiments of plastic materials have found surprisingly fast formation of nanodiamonds (ND) via X-ray probing. This mechanism is relevant for planetary models, but could also open efficient synthesis routes for tailored NDs. We investigate the release mechanics of compressed NDs by molecular dynamics simulation of the isotropic expansion of finite size diamond from different P-T states. Analysing the structural integrity along different release paths via molecular dynamic simulations, we found substantial disintegration rates upon shock release, increasing with the on-Hugnoiot shock temperature. We also find that recrystallization can occur after the expansion and hence during the release, depending on subsequent cooling mechanisms. Our study suggests higher ND recovery rates from off-Hugoniot states, e.g., via double-shocks, due to faster cooling. Laser-driven shock compression experiments of polyethylene terephthalate (PET) samples with in situ X-ray probing at the simulated conditions found diamond signal that persists up to 11 ns after breakout. In the diffraction pattern, we observed peak shifts, which we attribute to thermal expansion of the NDs and thus a total release of pressure, which indicates the stability of the released NDs. [ABSTRACT FROM AUTHOR]

Meteorites from interplanetary space often include high-pressure polymorphs of their constituent minerals, which provide records of past hypervelocity collisions. These collisions were expected to occur between kilometre-sized asteroids, generating transient high-pressure states lasting for several seconds to facilitate mineral transformations across the relevant phase boundaries. However, their mechanisms in such a short timescale were never experimentally evaluated and remained speculative. Here, we show a nanosecond transformation mechanism yielding ringwoodite, which is the most typical high-pressure mineral in meteorites. An olivine crystal was shock-compressed by a focused high-power laser pulse, and the transformation was time-resolved by femtosecond diffractometry using an X-ray free electron laser. Our results show the formation of ringwoodite through a faster, diffusionless process, suggesting that ringwoodite can form from collisions between much smaller bodies, such as metre to submetre-sized asteroids, at common relative velocities. Even nominally unshocked meteorites could therefore contain signatures of high-pressure states from past collisions. Meteorites from space often include denser polymorphs of their minerals, providing records of past hypervelocity collisions. An olivine mineral crystal was shock-compressed by a high-power laser, and its transformation into denser ringwoodite was time-resolved using an X-ray free electron laser. [ABSTRACT FROM AUTHOR]

We present structure and equation of state (EOS) measurements of biaxially orientated polyethylene terephthalate (PET, (C 10 H 8 O 4) n , also called mylar) shock-compressed to ( 155 ± 20 ) GPa and ( 6000 ± 1000 ) K using in situ X-ray diffraction, Doppler velocimetry, and optical pyrometry. Comparing to density functional theory molecular dynamics (DFT-MD) simulations, we find a highly correlated liquid at conditions differing from predictions by some equations of state tables, which underlines the influence of complex chemical interactions in this regime. EOS calculations from ab initio DFT-MD simulations and shock Hugoniot measurements of density, pressure and temperature confirm the discrepancy to these tables and present an experimentally benchmarked correction to the description of PET as an exemplary material to represent the mixture of light elements at planetary interior conditions. [ABSTRACT FROM AUTHOR]

The maximum value of the first derivative of the invasively measured left ventricular (LV) pressure (+ dP/dtmax or P′) is often used to quantify LV contractility, which in mice is limited to a single terminal study. Thus, determination of P′ in mouse longitudinal/serial studies requires a group of mice at each desired time point resulting in "pseudo" serial measurements. Alternatively, a noninvasive surrogate for P′ will allow for repeated measurements on the same group of mice, thereby minimizing physiological variability and requiring fewer animals. In this study we evaluated aortic acceleration and other parameters of aortic flow velocity as noninvasive indices of LV contractility in mice. We simultaneously measured LV pressure invasively with an intravascular pressure catheter and aortic flow velocity noninvasively with a pulsed Doppler probe in mice, at baseline and after the administration of the positive inotrope, dobutamine. Regression analysis of P′ versus peak aortic velocity (vp), peak velocity squared/rise time (vp2/T), peak (+ dvp/dt or v′p) and mean (+ dvm/dt or v′m) aortic acceleration showed a high degree of association (P′ versus: vp, r2 = 0.77; vp2/T, r2 = 0.86; v′p, r2 = 0.80; and v′m, r2 = 0.89). The results suggest that mean or peak aortic acceleration or the other parameters may be used as a noninvasive index of LV contractility. [ABSTRACT FROM AUTHOR]

The gas and ice giants in our solar system can be seen as a natural laboratory for the physics of highly compressed matter at temperatures up to thousands of kelvins. In turn, our understanding of their structure and evolution depends critically on our ability to model such matter. One key aspect is the miscibility of the elements in their interiors. Here, we demonstrate the feasibility of X-ray Thomson scattering to quantify the degree of species separation in a 1:1 carbon–hydrogen mixture at a pressure of ~150 GPa and a temperature of ~5000 K. Our measurements provide absolute values of the structure factor that encodes the microscopic arrangement of the particles. From these data, we find a lower limit of 2 4 − 7 + 6 % of the carbon atoms forming isolated carbon clusters. In principle, this procedure can be employed for investigating the miscibility behaviour of any binary mixture at the high-pressure environment of planetary interiors, in particular, for non-crystalline samples where it is difficult to obtain conclusive results from X-ray diffraction. Moreover, this method will enable unprecedented measurements of mixing/demixing kinetics in dense plasma environments, e.g., induced by chemistry or hydrodynamic instabilities. It is challenging to reliably probe the miscibility behavior of elements in extreme conditions. Here, the authors use X-ray Thomson scattering and compare to the X-ray diffraction method in order to determine mixing of different atomic species in warm dense matter conditions. [ABSTRACT FROM AUTHOR]

Purpose: To describe disorders that can masquerade as multiple evanescent white dot syndrome (MEWDS). Design: Retrospective, multicenter case series. Participants: Patients who presented with clinical findings compatible with a diagnosis of MEWDS but were ultimately diagnosed with an alternative inflammatory, infectious, or neoplastic disorder. Methods: Clinical records and multimodal imaging findings including fundus photography, fundus autofluorescence (FAF), fluorescein angiography (FA), indocyanine green angiography (ICGA), optical coherence tomography (OCT), and OCT angiography (OCTA) were analyzed. Main outcome measures: Inclusion criteria to be defined as a masquerade syndrome for MEWDS included the presence of disseminated grayish-white outer retinal spots that were hyperautofluorescent on FAF and associated with ellipsoid zone (EZ) disruption on OCT. Results: Twenty-two eyes of 13 patients were identified. All patients presented with the classic findings of MEWDS listed above. A MEWDS-like presentation was bilateral in nine of 13 patients (69%). Final diagnosis was determined on the basis of additional investigations including serologies and biopsy. These diagnoses included syphilis (three patients), lymphoma (three patients), idiopathic multifocal choroiditis (two patients), idiopathic retinal phlebitis (one patient), idiopathic acute zonal occult outer retinopathy (one patient), sarcoidosis (one patient), tuberculosis (one patient), and cancer-associated retinopathy (one patient). The outer retinal lesions and imaging findings resolved with treatment for the associated systemic disorders. Conclusions: Widespread grayish-white outer retinal spots associated with hyperautofluorescence on FAF and disruption of the EZ on OCT are not pathognomonic for MEWDS. A high index of suspicion must be maintained for masqueraders of MEWDS, which can include serious inflammatory, infectious, and neoplastic disorders. [ABSTRACT FROM AUTHOR]

Background: Nucleophosmin 1 (NPM1) is one of the most commonly mutated genes in acute myeloid leukemia, with mutations observed in approximately 30% of all adult cases. The persistence of NPM1 mutations following chemotherapy is associated with a greater risk of relapse as well as a lower rate of survival, making NPM1 measurable residual disease (MRD) an informative clinical target. Methods: Herein, we have developed a straightforward unique molecular identifier (UMI)-based amplicon next-generation sequencing method for the detection of NPM1-mutated MRD that addresses some of the limitations present in other assays. Results: The NPM1 assay allowed for accurate counting of individual mutant and wild-type molecules down to 0.01% variant allelic frequency. In silico contamination experiments highlighted the ability of this UMI methodology to maximize specificity through dramatic reductions in sequencing/demultiplexing bleed-through error. Conclusion: Performance and clinical utility of the NPM1 MRD assay are established via both validation experiments and analyses of live performance over 1.5 years of routine clinical service. [ABSTRACT FROM AUTHOR]

Species loss caused by anthropogenic disturbance threatens forest ecosystems globally. Until 50 years ago, the major sources of boreal forest disturbance in western Canada were a combination of forest wild fire events, pest insect outbreaks, and forest timber harvesting. However, in the 1960s, when the oil boom started in Alberta, oil and gas development along with oil sands mining quickly became another major forest disturbance agent. In this case study we report the effects of operational oil sands mine reclamation on terrestrial arthropod communities and compare them with nearby burned and mature forest sites as a way to provide a benchmark from which to understand the long-term trajectory of recovery for these groups. During the summer of 2016 over 6700 epigaeic beetles were collected using pitfall traps. A total of 43 species of ground beetles and 118 species of rove beetles were collected. Epigaeic beetle assemblages differed between the reclaimed, burned, and mature forest sites. Partitioning of beta diversity in the reclaimed, burned areas and mature forests indicated that species turnover formed the largest component of diversity. Species richness patterns were similar among sites; however, cluster analysis indicated that epigaeic beetle assemblages were only 20% similar between the reclaimed and natural sites. Although ground beetles of the reclaimed area showed positive spatial autocorrelation among treatments, both ground and rove beetles showed responses to the reclamation treatments. The reclaimed areas were dominated by small- to medium-sized open-habitat eurytopic species, whereas the fire and mature forest sites were dominated by larger forest species. The reclaimed area of this case study constitutes a novel, reconstructed ecosystem that is clearly not equivalent in species assemblage to burnt stands of similar age or to mature forest stands. [ABSTRACT FROM AUTHOR]

In this article, I highlight some core ideas that are important for understanding the parent-child relationship within the framework of political liberalism. I stress that, although some ideal or conception of the family is part of most, if not all, comprehensive doctrines, for political liberals, the state’s interest in the family is as a social-political institution in which certain needs of persons as free and equal citizens are met. I discuss the main needs and interests of children and parents in the parent-child relationship. I consider that many children are cared for by multiple people, and I discuss how the state should address the recognition of multiple legal parents. I discuss some contexts in which conflicts arise between the interests of children and caregivers and address how such conflicts should be resolved in the politically liberal state. Although Rawls failed to offer an acceptable account of the family as part of the basic structure and did not adequately address the role of caring relationships in a just society, I hope that this article helps to show how political liberals can offer a plausible account. [ABSTRACT FROM AUTHOR]

The power of human induced pluripotent stem cell (hiPSC)-based studies to resolve the smaller effects of common variants within the size of cohorts that can be realistically assembled remains uncertain. We identified and accounted for a variety of technical and biological sources of variation in a large case/control schizophrenia (SZ) hiPSC-derived cohort of neural progenitor cells and neurons. Reducing the stochastic effects of the differentiation process by correcting for cell type composition boosted the SZ signal and increased the concordance with post-mortem data sets. We predict a growing convergence between hiPSC and post-mortem studies as both approaches expand to larger cohort sizes. For studies of complex genetic disorders, to maximize the power of hiPSC cohorts currently feasible, in most cases and whenever possible, we recommend expanding the number of individuals even at the expense of the number of replicate hiPSC clones. [ABSTRACT FROM AUTHOR]

The atomic nucleus and its electrons are often thought of as independent systems that are held together in the atom by their mutual attraction. Their interaction, however, leads to other important effects, such as providing an additional decay mode for excited nuclear states, whereby the nucleus releases energy by ejecting an atomic electron instead of by emitting a γ-ray. This 'internal conversion' has been known for about a hundred years and can be used to study nuclei and their interaction with their electrons. In the inverse process-nuclear excitation by electron capture (NEEC)-a free electron is captured into an atomic vacancy and can excite the nucleus to a higher-energy state, provided that the kinetic energy of the free electron plus the magnitude of its binding energy once captured matches the nuclear energy difference between the two states. NEEC was predicted in 1976 and has not hitherto been observed. Here we report evidence of NEEC in molybdenum-93 and determine the probability and cross-section for the process in a beam-based experimental scenario. Our results provide a standard for the assessment of theoretical models relevant to NEEC, which predict cross-sections that span many orders of magnitude. The greatest practical effect of the NEEC process may be on the survival of nuclei in stellar environments, in which it could excite isomers (that is, long-lived nuclear states) to shorter-lived states. Such excitations may reduce the abundance of the isotope after its production. This is an example of 'isomer depletion', which has been investigated previously through other reactions, but is used here to obtain evidence for NEEC. [ABSTRACT FROM AUTHOR]

Chronic drug abuse, craving, and relapse are thought to be linked to long-lasting changes in neural gene expression arising through transcriptional and chromatin-related mechanisms. The key contributions of midbrain dopamine (DA)-synthesizing neurons throughout the addiction process provide a compelling rationale for determining the drug-induced molecular changes that occur in these cells. Yet our understanding of these processes remains rudimentary. The postmortem human brain constitutes a unique resource that can be exploited to gain insights into the pathophysiology of complex disorders such as drug addiction. In this study, we analyzed the profiles of midbrain gene expression in chronic cocaine abusers and well-matched drug-free control subjects using microarray and quantitative PCR. A small number of genes exhibited robust differential expression; many of these are involved in the regulation of transcription, chromatin, or DA cell phenotype. Transcript abundances for approximately half of these differentially expressed genes were diagnostic for assigning subjects to the cocaine-abusing vs control cohort. Identification of a molecular signature associated with pathophysiological changes occurring in cocaine abusers' midbrains should contribute to the development of biomarkers and novel therapeutic targets for drug addiction. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]

This study examined the impact of victim, offender, and case characteristics on the decision to accept cases of child maltreatment for prosecution. Data were collected over a 2-year period from a large southern Children's Advocacy Center, and the final sample consisted of 467 substantiated cases of child sexual abuse, physical abuse, and neglect. Logistic regression results indicated that sexual abuse cases were significantly more likely to be accepted for prosecution compared to physical abuse and neglect. Additionally, cases involving female victims and male offenders were more likely to be moved forward. When each type of maltreatment was examined separately, logistic regression results indicated that victim and offender age significantly impacted the decision to prosecute sexual abuse cases. Offender gender and age, as well as availability of medical evidence predicted physical abuse case acceptance, and offender gender and frequency of maltreatment significantly impacted prosecutorial decision making for cases of neglect. [ABSTRACT FROM PUBLISHER]

Dominant selectable markers are beneficial for transformation of many fungi, particularly those model species where repeated transformations may be required. A carboxin resistance allele of the Coprinopsis cinerea sdi1 gene, encoding the iron-sulphur protein subunit of succinate dehydrogenase, was developed by introducing a suitable point mutation in the histidine block responsible for binding of the associated iron ion. This modified gene was used successfully to confer carboxin resistance upon transformation of C. cinerea protoplasts. Plasmids previously used to establish hygromycin transformation systems of several basidiomycete species, such as pAN7-1 and phph004, failed to give rise to hygromycin-resistant transformants of C. cinerea, whilst pPHT1 was successful . Sequencing of these constructs showed that the hygromycin resistance gene in pAN7-1 and phph004 had been modified removing the codons encoding two lysine residues following the N-terminal methionine. Replacement of the deleted 6 bp (AAA AAG) in the truncated hph gene led to generation of hygromycin-resistant transformants indicating the importance of these two codons for expression in C. cinerea. Phleomycin-resistant ( ble) transformants were also obtained, but only with the intron-containing construct pblei004, showing that an intron is necessary to obtain phleomycin-resistant C. cinerea. This contrasts with hygromycin-resistance , where introns are not required for expression, emphasising the variability in importance of these elements. [ABSTRACT FROM AUTHOR]

Neutron-rich radioactive ion beams available from the HRIBF allow a variety of measurements around the 132Sn region, including Coulomb excitation and single-nucleon transfer. The B( E2;0+ → 2+) values for first 2+ excited states of even-even neutron-rich 132-136Te and 126-130Sn have been measured by Coulomb excitation in inverse kinematics. Neutron transfer onto a 134Te beam from 9Be and 13C targets, to populate single-particle states in 135Te, has also been studied. Gamma rays from the 13C(134Te, 12C) reaction were used to identify the ν i13/2 state in 135Te, at an energy of 2109 keV. These and other results, and plans for future experiments with these neutron-rich beams, are presented. [ABSTRACT FROM AUTHOR]

Introduction: The transgenic mouse is a popular model for human inherited cardiac disease. Electrophysiology (EP) studies have recently been performed in transgenic mice to characterize the electrical phenotype of the heart. However, little is known regarding the impact of experimental conditions or model selection on the outcome of EP studies in mice.Methods and Results: We investigated the effects of experimental conditions on mouse cardiac EP by (1) comparing the findings of transesophageal pacing with those of invasive intracardiac pacing, (2) elucidating the effects of commonly used anesthetic agents, and (3) determining the impact of changes in body temperature. We also investigated the effects of model selection by (1) studying the dependence on mouse strain, and (2) exploring the effects of age. We found that EP parameters derived by both transesophageal and intracardiac pacing/recordings methods were similar. On the other hand, the anesthetic mixture of ketamine, xylazine, and acepromazine had profound effects on cardiac EP compared to sodium pentobarbital or isoflurane. Meanwhile, compared to normal body temperature (97-99 F), low body temperature (92-94 F) prolonged most cardiac EP parameters, while high body temperature (102-104 F) had little effect. Heart rate was a sensitive indicator of changes in body temperature. Significant differences were observed in specialized conduction system properties among the mouse strains studied (FVB, C57, and DBA). Furthermore, atrial electrical remodeling was evidently associated with age, while ventricular electrical properties were virtually unaltered. In comparison with corresponding invasive EP parameters, we found that the QT interval was not a reliable EP index in the mouse.Conclusions: Cardiac EP variability may result from differences in experimental techniques including anesthesia and body temperature and from differences in mouse selection including strain and age. The influence of these factors should be considered when characterizing the electrical phenotype of transgenic mice in cardiovascular research. [ABSTRACT FROM AUTHOR]

While the hydantoin-hydrolysing enzymes from Agrobacterium strains are used as biocatalysts in the commercial production of D-p-hydroxyphenylglycine, they are now mostly produced in heterologous hosts such as Escherichia coli. This is due to the fact that the activity of these enzymes in the native strains is tightly regulated by growth conditions. Hydantoinase and N-carbamoylamino acid amidohydrolase (NCAAH) activities are induced when cells are grown in the presence of hydantoin or an hydantoin analogue, and in complete medium, enzyme activity can be detected only in early stationary growth phase. In this study, the ability of Agrobacterium tumefaciens RU-OR cells to produce active enzymes was found to be dependent upon the choice of nitrogen source and the presence of inducer, 2-thiouracil, in the growth medium. Growth with (NH4)2SO4 as the nitrogen source repressed the production of both enzymes (nitrogen repression) and also resulted in a rapid, but reversible loss of hydantoinase activity in induced cells (ammonia shock). Mutant strains with inducer-independent production of the enzymes and/or altered response to nitrogen control were isolated. Of greatest importance for industrial application was strain RU-ORPN1F9, in which hydantoinase and NCAAH enzyme activity was inducer-independent and no longer sensitive to nitrogen repression or ammonia shock. Such mutants offer the potential for native enzyme production levels equivalent to those achieved by current heterologous expression systems. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Anaesthesia / Journal Canadien d'Anesthésie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Anaesthesia / Journal Canadien d'Anesthésie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The evolution of the π h11/2ν h11/2 and π h11/2ν s1/2 isomeric configurations was studied for the N = 77 isotones near the proton drip line. The decays of metastable levels in 140Eu, 142Tb , and 144Ho were measured by means of X-, gamma- and conversion electron spectroscopy at the Recoil Mass Spectrometer at Oak Ridge. The sequence of isomeric levels in 140Eu was experimentally determined. The half-life of the π h11/2ν h11/2 state in 142Tb was remeasured to be 25(1) μs. The spins and parities of 5- and 8+ for the π h11/2ν s1/2 and π h11/2ν h11/2142Tb isomers, respectively, were established from measured multipolarities. No evidence for the expected 1+ ground state was found in the 144Ho decay data. [ABSTRACT FROM AUTHOR]

Examines a form of radionuclide ventriculography used to quantify right ventricular and left ventricular ejection fraction in man for use in mice. Blood imaging through the detection of tracer radioactivity; Range of ejection fractions; Accuracy and resolution.

The Planning-Programming-Budgeting System (PPBS) is a newly developed concept for using computers to help determine priorities in allocating scarce resources to the ever-expanding demands of public education. It is designed to handle information in a better manner than traditional accounting procedures in planning the cost of immediate and long-range educational goals. Describes the system and says that it is necessary to understand both the advantages and limitations for it to be properly used.

In the originally published version of this Article, the affiliation details for Eric E. Schadt and Radoslav Savic incorrectly omitted ‘Sema4, a Mount Sinai venture, Stamford, Connecticut, USA’. This has been corrected in both the PDF and HTML versions of the Article. [ABSTRACT FROM AUTHOR]

A lack of biologically relevant screening models hinders the discovery of better treatments for schizophrenia (SZ) and other neuropsychiatric disorders. Here we compare the transcriptional responses of 8 commonly used cancer cell lines (CCLs) directly with that of human induced pluripotent stem cell (hiPSC)-derived neural progenitor cells (NPCs) from 12 individuals with SZ and 12 controls across 135 drugs, generating 4320 unique drug-response transcriptional signatures. We identify those drugs that reverse post-mortem SZ-associated transcriptomic signatures, several of which also differentially regulate neuropsychiatric disease-associated genes in a cell type (hiPSC NPC vs. CCL) and/or a diagnosis (SZ vs. control)-dependent manner. Overall, we describe a proof-of-concept application of transcriptomic drug screening to hiPSC-based models, demonstrating that the drug-induced gene expression differences observed with patient-derived hiPSC NPCs are enriched for SZ biology, thereby revealing a major advantage of incorporating cell type and patient-specific platforms in drug discovery. Unbiased large scale screening of small molecules for drug discovery in psychiatric disease is technically challenging and financially costly. Here, Readhead and colleagues integrate in silico and in vitro approaches to design and conduct transcriptomic drug screening in schizophrenia patient-derived neural cells, in order to survey novel pathologies and points of intervention. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented regarding the difference of tyrosine hydroxylase (TH)-positive dopaminergic (DA) neurons from human-induced pluripotent stem cells (hiPSCs) derived from schizophrenia (SZ) patients.