An x-ray optic calibration facility for high energy density diagnostics

A facility to calibrate x-ray imaging optics was built at Lawrence Livermore National Laboratory to support high energy density (HED) and inertial confinement fusion (ICF) diagnostics such as those at the National Ignition Facility and the Sandia Z-Machine. Calibration of the spectral reflectivity and resolution of these x-ray diagnostics enable absolute determination of the x-ray flux and wavelengths generated in the HED and ICF experiments. Measurement of the optic point spread function is used to determine spatial resolution of the optic. This facility was constructed to measure (1) the x-ray reflectivity to ±5% over a spectral range from 5 to 60 keV; (2) point spread functions with a resolution of 50 μm (currently) and 13 μm (future) in the image plane; and (3) optic distance relative to the x-ray source and detector to within ±100 μm in each dimension. This article describes the capabilities of the calibration facility, concept of operations, and initial data from selected x-ray optics.

Delayed Onset of Nonthermal Melting in Single-Crystal Silicon Pumped with Hard X Rays

In this work, we monitor the onset of nonthermal melting in single-crystal silicon by implementing an x-ray pump-x-ray probe scheme. Using the ultrashort pulses provided by the Linac Coherent Light Source (SLAC) and a custom-built split-and-delay line for hard x rays, we achieve the temporal resolution needed to detect the onset of the transition. Our data show no loss of long-range order up to 150±40  fs from photoabsorption, which we interpret as the time needed for the electronic system to equilibrate at or above the critical nonthermal melting temperature. Once such equilibration is reached, the loss of long-range atomic order proceeds inertially and is completed within 315±40  fs from photoabsorption.

Single molecule real-time DNA sequencing of HLA genes at ultra-high resolution from 126 International HLA and Immunogenetics Workshop cell lines

The hyperpolymorphic HLA genes play important roles in disease and transplantation and act as genetic markers of migration and evolution. A panel of 107 B-lymphoblastoid cell lines (B-LCLs) was established in 1987 at the 10th International Histocompatibility Workshop as a resource for the immunogenetics community. These B-LCLs are well characterised and represent diverse ethnicities and HLA haplotypes. Here we have applied Pacific Biosciences' Single Molecule Real-Time (SMRT) DNA sequencing to HLA type 126 B-LCL, including the 107 International HLA and Immunogenetics Workshop (IHIW) cells, to ultra-high resolution. Amplicon sequencing of full-length HLA class I genes (HLA-A, -B and -C) and partial length HLA class II genes (HLA-DRB1, -DQB1 and -DPB1) was performed. We typed a total of 931 HLA alleles, 895 (96%) of which were consistent with the typing in the IPD-IMGT/HLA Database (Release 3.27.0, January 20, 2017), with 595 (64%) typed at a higher resolution. Discrepant types, including novel alleles (n = 10) and changes in zygosity (n = 13), as well as previously unreported types (n = 34) were observed. In addition, patterns of linkage disequilibrium were distinguished by four-field resolution typing of HLA-B and HLA-C. By improving and standardising the HLA typing of these B-LCLs, we have ensured their continued usefulness as a resource for the immunogenetics community in the age of next generation DNA sequencing.

Study of η and η' Photoproduction at MAMI

The reactions γp→ηp and γp→η^{'}p are measured from their thresholds up to the center-of-mass energy W=1.96  GeV with the tagged-photon facilities at the Mainz Microtron, MAMI. Differential cross sections are obtained with unprecedented statistical accuracy, providing fine energy binning and full production-angle coverage. A strong cusp is observed in the total cross section for η photoproduction at the energies in the vicinity of the η^{'} threshold, W=1896  MeV (E_{γ}=1447  MeV). Within the framework of a revised ηMAID isobar model, the cusp, in connection with a steep rise of the η^{'} total cross section from its threshold, can only be explained by a strong coupling of the poorly known N(1895)1/2^{-} state to both ηp and η^{'}p. Including the new high-accuracy results in the ηMAID fit to available η and η^{'} photoproduction data allows the determination of the N(1895)1/2^{-} properties.

Patterns of Multivitamin Use after Colorectal Cancer Diagnosis in Association with Long-term Survival

Multivitamin use has been related to a modest reduced risk of colorectal cancer (CRC), but evidence on its use after diagnosis in relation to survival has been limited. Incident, invasive CRC cases were identified through cancer registries from 1997–2008 and enrolled in four population-based sites of the Colon Cancer Family Registry (Fred Hutchinson Cancer Research Center, Cancer Care Ontario, Mayo Clinic, and the Universities of Queensland and Melbourne). At enrollment, a standardized interview ascertained multivitamin use in the year prior to diagnosis. A follow-up questionnaire was administered approximately 5 years after baseline, with 2,586 participants providing information on their multivitamin use at both time points. Survival outcomes were identified through linkage to national death registries. Delayed-entry Cox regression was used to estimate the association between patterns of multivitamin use and overall or CRC-specific survival (Hazard Ratio (HR) and 95% Confidence Interval (CI)), with survival time beginning at the 5-year follow-up survey. Models were adjusted for age at diagnosis, sex, body mass index, smoking history, stage, study center, and number of days from diagnosis to baseline survey. Over a median 4.8 years after the follow-up survey, 397 participants died (103 from CRC). Multivitamin use was common: at the 5-year follow-up, 37% reported continued use since before diagnosis, 12% had initiated use, 17% had discontinued use, and only 34% participants reported never using multivitamins. Compared to never use of multivitamins, continued use was significantly associated with increased subsequent overall survival (HR = 0.71, 95% CI: 0.55–0.91). However, this association did not reach statistical significance for CRC-specific survival (HR = 0.76, 95% CI: 0.47–1.24). No significant association was observed for discontinuing (HR = 0.92, 95% CI: 0.68–1.25) or initiating (HR = 0.80, 95% CI: 0.55–1.13) multivitamin use from baseline to follow-up, compared to never users, though initiating use trended towards increased survival. These findings suggest that continuing multivitamin use after a CRC diagnosis may increase survival; replication and details on the specific micronutrients included are needed.

Carotid Doppler flowmetry correlates poorly with thermodilution cardiac output following cardiac surgery

BACKGROUND

It remains unclear whether measuring carotid arterial flow by the time velocity integral using vascular Doppler ultrasound can be used to monitor cardiac output and volume responsiveness.

METHODS

The carotid Doppler flow (time velocity integral and peak flow velocity variation) was assessed in triplicate by an intensivist with formal vascular ultrasound training. Thirty-three patients admitted following coronary by-pass surgery were studied before and after a passive leg-raising manoeuvre to investigate volume responsiveness (more than 10% increase in cardiac output) along with indices of arterial load measuring cardiac output by thermodilution. Pearson's correlation coefficient and area under the curve (AUC) by receiver operating characteristics were calculated.

RESULTS

A significant correlation between carotid Doppler flow and cardiac output was demonstrated in post-operative cardiac surgery patients (r = 0.80 [95%CI 0.61-0.89]), including relative changes following passive leg raising (r = 0.79 [95%CI 0.60-0.89]) that showed a mean difference of 2% with wide limits of agreements (-19% to 16%). Changes in carotid Doppler flow following passive leg raising correlated with the baseline arterial resistance but not with compliance or effective elastance. A peak flow variation > 10% before passive leg raising discriminated responders to the manoeuvre with an AUC of 0.81 [95% CI 0.55-0.95].

CONCLUSIONS

Weak correlations between common carotid Doppler flow and cardiac output mean that the methods cannot be used interchangeably in post-operative cardiac surgery patients.

CrossFitter’s knee: patellofemoral chondral injury following high-intensity functional training

We present a case series of patients with patellofemoral joint (PFJ) chondral injuries presenting as anterior knee pain secondary to participation in high-intensity functional training programmes. We aim to highlight PFJ chondral injuries as a potential complication of military servicemen engaging in high-intensity functional training programmes. This may allow medical staff to identify the injuries early, and highlight this possible injury mechanism to Physical Training staff to help educate participants and mitigate the risk of injury.

Self-Referenced Coherent Diffraction X-Ray Movie of Ångstrom- and Femtosecond-Scale Atomic Motion

Time-resolved femtosecond x-ray diffraction patterns from laser-excited molecular iodine are used to create a movie of intramolecular motion with a temporal and spatial resolution of 30 fs and 0.3 Å. This high fidelity is due to interference between the nonstationary excitation and the stationary initial charge distribution. The initial state is used as the local oscillator for heterodyne amplification of the excited charge distribution to retrieve real-space movies of atomic motion on ångstrom and femtosecond scales. This x-ray interference has not been employed to image internal motion in molecules before. Coherent vibrational motion and dispersion, dissociation, and rotational dephasing are all clearly visible in the data, thereby demonstrating the stunning sensitivity of heterodyne methods.

A linear random growth model

Points start to form on an ‘uncovered' unit interval according to a Poisson process with parameter λ. From newly formed points a covering region grows in both directions at velocity v, while new points continue to form on uncovered parts of the interval. Eventually the whole interval will be covered. Let N ≧ 1 denote the total number of points formed. We derive integral expressions for E(N) and Var(N) and give precise asymptotic expressions for these moments as ρ = λ/v →∞. Asymptotic normality of N is also established.

Ultrafast energy- and momentum-resolved dynamics of magnetic correlations in the photo-doped Mott insulator Sr2IrO4

Measuring how the magnetic correlations evolve in doped Mott insulators has greatly improved our understanding of the pseudogap, non-Fermi liquids and high-temperature superconductivity. Recently, photo-excitation has been used to induce similarly exotic states transiently. However, the lack of available probes of magnetic correlations in the time domain hinders our understanding of these photo-induced states and how they could be controlled. Here, we implement magnetic resonant inelastic X-ray scattering at a free-electron laser to directly determine the magnetic dynamics after photo-doping the Mott insulator Sr2IrO4. We find that the non-equilibrium state, 2 ps after the excitation, exhibits strongly suppressed long-range magnetic order, but hosts photo-carriers that induce strong, non-thermal magnetic correlations. These two-dimensional (2D) in-plane Néel correlations recover within a few picoseconds, whereas the three-dimensional (3D) long-range magnetic order restores on a fluence-dependent timescale of a few hundred picoseconds. The marked difference in these two timescales implies that the dimensionality of magnetic correlations is vital for our understanding of ultrafast magnetic dynamics.

A comparative reference study for the validation of HLA-matching algorithms in the search for allogeneic hematopoietic stem cell donors and cord blood units

The accuracy of human leukocyte antigen (HLA)‐matching algorithms is a prerequisite for the correct and efficient identification of optimal unrelated donors for patients requiring hematopoietic stem cell transplantation. The goal of this World Marrow Donor Association study was to validate established matching algorithms from different international donor registries by challenging them with simulated input data and subsequently comparing the output. This experiment addressed three specific aspects of HLA matching using different data sets for tasks of increasing complexity. The first two tasks targeted the traditional matching approach identifying discrepancies between patient and donor HLA genotypes by counting antigen and allele differences. Contemporary matching procedures predicting the probability for HLA identity using haplotype frequencies were addressed by the third task. In each task, the identified disparities between the results of the participating computer programs were analyzed, classified and quantified. This study led to a deep understanding of the algorithms participating and finally produced virtually identical results. The unresolved discrepancies total to less than 1%, 4% and 2% for the three tasks and are mostly because of individual decisions in the design of the programs. Based on these findings, reference results for the three input data sets were compiled that can be used to validate future matching algorithms and thus improve the quality of the global donor search process.

Systemic inflammation and liver damage in HIV/hepatitis C virus coinfection

OBJECTIVES

Chronic hepatitis C virus (HCV) and HIV viral infections are characterized by systemic inflammation. Yet the relative levels, drivers and correlates of inflammation in these settings are not well defined.

METHODS

Seventy-nine HIV-infected patients who had been receiving antiretroviral therapy (ART) for more than 2 years and who had suppressed plasma HIV levels (< 50 HIV-1 RNA copies/mL) were included in the study. Two patient groups, HCV-positive/HIV-positive and HCV-negative/HIV-positive, and a control group comprised of healthy volunteers (n = 20) were examined. Markers of systemic inflammation [interleukin (IL)-6, interferon gamma-induced protein (IP)-10, soluble tumour necrosis factor receptor-I (sTNF-RI) and sTNF-RII], monocyte/macrophage activation [soluble CD163 (sCD163), soluble CD14 and neopterin], intestinal epithelial barrier loss [intestinal fatty acid binding protein (I-FABP) and lipopolysaccharide (LPS)] and coagulation (d-dimers) were analysed. CD4 naïve T cells and CD4 recent thymic emigrants (RTEs) were enumerated.

RESULTS

Plasma levels of IP-10, neopterin and sCD163 were higher in HCV/HIV coinfection than in HIV monoinfection and were positively correlated with indices of hepatic damage [aspartate aminotransferase (AST), alanine aminotransferase (ALT) and the AST to platelet ratio index (APRI)]. Levels of I-FABP were comparably increased in HIV monoinfection and HIV/HCV coinfection but LPS concentrations were highest in HCV/HIV coinfection, suggesting impaired hepatic clearance of LPS. Plasma HCV levels were not related to any inflammatory indices except sCD163. In coinfected subjects, a previously recognized relationship of CD4 naïve T-cell and RTE counts to hepatocellular injury was defined more mechanistically by an inverse relationship to sCD163.

CONCLUSIONS

Hepatocellular injury in HCV/HIV coinfection is linked to elevated levels of certain inflammatory cytokines and an apparent failure to clear systemically translocated microbial products. A related decrease in CD4 naïve T cells and RTEs also merits further exploration.

A Developmental-Genetic Analysis of Continuity and Change in the Bayley Mental Development Index from 14 to 24 Months: The MacArthur Longitudinal Twin Study

A developmental-genetic model was fitted to Bayley Mental Development Index (MDI) data to address questions concerning the origins of individual differences in MDI performance and the origins of change and continuity during infancy More than 350 pairs of identical and same-sex fraternal twins were studied longitudinally at 14, 20, and 24 months of age There was substantial genetic continuity of general cognitive ability from 14 to 24 months, but significant new genetic variation also appeared at 24 months Shared family environmental influences were global across all three ages and not time-specific Finally, nonshared environmental influences did not contribute to the observed continuity of general cognitive ability, only to change

Multicentre study of short-course radiotherapy and transanal endoscopic microsurgery for early rectal cancer

Background

Organ-preserving treatment for early-stage rectal cancer may avoid the substantial perioperative morbidity and functional sequelae associated with total mesorectal excision (TME). The initial results of an organ-preserving approach using preoperative short-course radiotherapy (SCRT) and transanal endoscopic microsurgery (TEMS) are presented.

Methods

Patients with cT1–2N0 rectal cancers staged using high-quality MRI and endorectal ultrasonography received SCRT, with TEMS 8–10 weeks later, at four regional referral centres between 2007 and 2013. Patients were generally considered high risk for TME surgery (a small number refused TME).

Results

Following SCRT and TEMS, 60 (97 per cent) of 62 patients had an R0 resection. Histopathological staging identified 20 ypT0 tumours, 23 ypT1, 18 ypT2 and one ypT3. Preoperative uT category was significantly associated with a complete pathological response, which was achieved in 13 of 27 patients with uT0/uT1 disease and in five of 29 with uT2 (P = 0·010). Acute complications affected 19 patients, the majority following TEMS. No fistulas occurred and no stomas were formed. Surveillance detected four intraluminal local recurrences at a median follow-up of 13 months, all in patients with tumours staged as ypT2. Salvage TME achieved R0 resection in three patients and a stent was placed in one patient owing to co-morbidities.

Conclusion

SCRT with TEMS was effective in the majority of patients considered high risk for (or who refused) TME surgery.

Pre- and Post-Natal Stress Programming: Developmental Exposure to Glucocorticoids Causes Long-Term Brain-Region Specific Changes to Transcriptome in the Precocial Japanese Quail

Exposure to stress during early development can permanently influence an individual's physiology and behaviour, and affect its subsequent health. The extent to which elevated glucocorticoids cause such long-term 'programming' remains largely untested. In the present study, using the Japanese quail as our study species, we independently manipulated exposure to corticosterone during pre- and/or post-natal development and investigated the subsequent effects on global gene expression profiles within the hippocampus and hypothalamus upon achieving adulthood. Our results showed that the changes in transcriptome profiles in response to corticosterone exposure clearly differed between the hippocampus and the hypothalamus. We also showed that these effects depended on the developmental timing of exposure and identified brain-region specific gene expression patterns that were either: (i) similarly altered by corticosterone regardless of the developmental stage in which hormonal exposure occurred or (ii) specifically and uniquely altered by either pre-natal or post-natal exposure to corticosterone. Corticosterone-treated birds showed alterations in networks of genes that included known markers of the programming actions of early-life adversity (e.g. brain-derived neurotrophic factor and mineralocorticoid receptor within the hippocampus; corticotrophin-releasing hormone and serotonin receptors in the hypothalamus). Altogether, for the first time, these findings provide experimental support for the hypothesis that exposure to elevated glucocorticoids during development may be a key hormonal signalling pathway through which the long-term phenotypic effects associated with early-life adversity emerge and potentially persist throughout the lifespan. These data also highlight that stressors might have different long-lasting impacts on the brain transcriptome depending on the developmental stage in which they are experienced; more work is now required to relate these mechanisms to organismal phenotypic differences.

Patterns of adaptation to children's food allergies

BACKGROUND

Families with food allergy (FA) are at risk of reduced quality of life and elevated anxiety. A moderate level of anxiety may be beneficial to sustain vigilance for food avoidance; however, excessive anxiety may increase risk for burden and maladjustment. The current study presents a framework for understanding the patterns of adaptation to FA across families and to identify typologies of families that would benefit from intervention.

METHODS

Participants included 57 children, 6-12 years old with documented FA, and their mothers. Families were assessed using the Food Allergy Management and Adaptation Scale. Families also completed measures of quality of life, anxiety, FA management, and psychosocial impairment.

RESULTS

A hierarchical cluster analysis revealed that 56 of the 57 families of food-allergic children were categorized into four groups that differed on their adequacy of family FA management, levels of anxiety, and balanced psychosocial functioning: balanced responders (n = 23; 41%), high responders (n = 25; 45%), and low responders (n = 3; 5%). The fourth group, anxious high responders (n = 5; 9%), was characterized by extremely high maternal FA anxiety scores and low scores for balanced integration of FA management and psychosocial functioning. Families in clusters differed across illness and psychosocial outcome variables.

CONCLUSION

Families with FA were characterized by patterns of FA management, anxiety, and ability to integrate FA demands into daily life. Identified adaptation patterns correspond with clinical impressions and provide a framework for identifying families in need of intervention.