Neutron sub-micrometre tomography from scattering data

Neutrons are valuable probes for various material samples across many areas of research. Neutron imaging typically has a spatial resolution of larger than 20 µm, whereas neutron scattering is sensitive to smaller features but does not provide a real-space image of the sample. A computed-tomography technique is demonstrated that uses neutron-scattering data to generate an image of a periodic sample with a spatial resolution of ∼300 nm. The achieved resolution is over an order of magnitude smaller than the resolution of other forms of neutron tomography. This method consists of measuring neutron diffraction using a double-crystal diffractometer as a function of sample rotation and then using a phase-retrieval algorithm followed by tomographic reconstruction to generate a map of the sample's scattering-length density. Topological features found in the reconstructions are confirmed with scanning electron micrographs. This technique should be applicable to any sample that generates clear neutron-diffraction patterns, including nanofabricated samples, biological membranes and magnetic materials, such as skyrmion lattices.

Cogeneration of hot electrons from multiple laser-plasma instabilities

Interactions of two-plasmon decay (TPD) and side-stimulated Raman scattering (SSRS) were studied using three-dimensional particle-in-cell simulations under inertial-confinement-fusion-relevant conditions for linearly and circularly polarized lasers. In the linear stage, SSRS took place under n_{e}=0.235n_{c} and TPD dominated near the quarter-critical density surface and their growth rates agreed with theory. In the nonlinear stage, SSRS reduced TPD through pump depletion. Hot electrons were found to be first accelerated by SSRS plasma waves and then by TPD plasma waves through a cogeneration mechanism. Compared to the linearly polarized case with the same laser intensity, both SSRS and TPD were reduced due to the lower laser amplitude in the circularly polarized case. As a result, a 30% decrease in hot electron flux was observed.

Clinical characteristics and radiological features of children infected with the 2019 novel coronavirus

AIM

To identify and summarise the common findings from 2019 novel coronavirus (2019-nCoV) infections in children.

MATERIALS AND METHODS

The clinical characteristics and radiological findings (chest radiography and chest computed tomography [CT]) of nine children infected with the 2019-nCoV were reviewed in this retrospective case series.

RESULTS

Among the children, six had fever (including two children with cough), one had only cough, one had a stuffy nose when initially diagnosed, and one was an asymptomatic carrier. Chest radiographs seemed mostly normal in six cases whereas increased and/or disordered bilateral bronchovascular shadows and dense hilar shadows were seen in three cases. Chest CT exhibited no obvious abnormal signs in four cases. Typical CT findings included patchy, peripheral ground-grass opacities, subpleural lamellar dense shadows, and parenchymal bands. Pleural effusions, mediastinal lymphadenopathy, cavitation, and pleural thickening were absent.

CONCLUSION

The clinical manifestations and radiological findings of the 2019-nCoV-infected children were mild and lacked a typical pattern.

Pump depletion and hot-electron generation in long-density-scale-length plasma with shock-ignition high-intensity laser

Two-dimensional particle-in-cell simulations for laser plasma interaction with laser intensity of 10^{16}W/cm^{2}, plasma density range of 0.01-0.28n_{c}, and scale length of 230-330μm showed significant pump depletion of the laser energy due to stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SBS) in the low-density region (n_{e}=0.01-0.2n_{c}). The simulations identified hot electrons generated by SRS in the low-density region with moderate energy and by two-plasmon-decay near n_{e}=0.25n_{c} with higher energy. The overall hot electron temperature (46 keV) and conversion efficiency (3%) were consistent with the experiment's measurements. The simulations also showed artificially reducing SBS would lead to stronger SRS and a softer hot-electron spectrum.

Are left ventricular muscle area and radiation attenuation associated with overall survival in advanced pancreatic cancer patients treated with chemotherapy?

AIM

To evaluate whether cardiac muscle area and radiation attenuation, determined using pre-chemotherapy computed tomography (CT), are associated with therapeutic response and overall survival (OS) in chemotherapy-treated advanced pancreatic cancer (APC) patients.

MATERIALS AND METHODS

Ninety-eight chemotherapy-treated APC patients who underwent pre-chemotherapy CT between 2009 and 2018 were considered. Left ventricular muscle area (LVMA) and left ventricular muscle radiation attenuation (LVMRA) were measured using pre-chemotherapy arterial-phase CT. OS and progression-free survival (PFS) were analysed using Kaplan-Meier curves. Univariate and multivariate Cox regression analyses were performed to analyse potential factors affecting OS and PFS.

RESULTS

Patients with low LVMRA, low LVMA at baseline CT, and multiple metastases had a significantly shorter median OS than patients with high LVMRA, high LVMA, and without multiple metastases (8.8 versus 14 months, p=0.017; 12.2 versus 18.1 months, p=0.038; 7.3 versus 13.5 months, p<0.001, respectively). Patients with low LVMRA and distant metastasis had a shorter median PFS than patients with high LVMRA and those without distant metastasis (4.9 versus 8.3 months, p=0.032; 5.4 versus 9.9 months, p=0.002, respectively). Moreover, the mean LVMRA was the highest in the partial response group (p=0.028).

CONCLUSION

LVMRA could well predict PFS and OS in chemotherapy-treated APC patients.

Three-dimensional particle-in-cell modeling of parametric instabilities near the quarter-critical density in plasmas

The nonlinear regime of laser-plasma interactions including both two-plasmon decay (TPD) and stimulated Raman scattering (SRS) instabilities has been studied in three-dimensional (3D) particle-in-cell simulations with parameters relevant to the inertial confinement fusion (ICF) experiments. SRS and TPD develop in the same region in plasmas, and the generation of fast electrons can be described accurately with only the full model including both SRS and TPD. The growth of instabilities in the linear stage is found to be in good agreement with analytical theories. In the saturation stage the low-frequency density perturbations driven by the daughter waves of the SRS side scattering can saturate the TPD and consequently inhibit the fast-electron generation. The fast-electron flux in 3D modeling is up to an order of magnitude smaller than previously reported in 2D TPD simulations, bringing it close to the results of ICF experiments.

Self-Generated Magnetic and Electric Fields at a Mach-6 Shock Front in a Low Density Helium Gas by Dual-Angle Proton Radiography

Shocks are abundant both in astrophysical and laboratory systems. While the electric fields generated at shock fronts have recently attracted great attention, the associated self-generated magnetic field is rarely studied, despite its ability to significantly affect the shock profile in the nonideal geometry where density and temperature gradients are not parallel. We report here the observation of a magnetic field at the front of a Mach ∼6 shock propagating in a low-density helium gas system. Proton radiography from different projection angles not only confirms the magnetic field's existence, but also provides a quantitative measurement of the field strength in the range ∼5 to 7 T. X-ray spectrometry allowed inference of the density and temperature at the shock front, constraining the plasma conditions under which the magnetic and electric fields are generated. Simulations with the particle-in-cell code lsp attribute the self-generation of the magnetic field to the Biermann battery effect (∇n_{e}×∇T_{e}).

Optical creation of a supercrystal with three-dimensional nanoscale periodicity

Stimulation with ultrafast light pulses can realize and manipulate states of matter with emergent structural, electronic and magnetic phenomena. However, these non-equilibrium phases are often transient and the challenge is to stabilize them as persistent states. Here, we show that atomic-scale PbTiO₃/SrTiO₃ superlattices, counterpoising strain and polarization states in alternate layers, are converted by sub-picosecond optical pulses to a supercrystal phase. This phase persists indefinitely under ambient conditions, has not been created via equilibrium routes, and can be erased by heating. X-ray scattering and microscopy show this unusual phase consists of a coherent three-dimensional structure with polar, strain and charge-ordering periodicities of up to 30 nm. By adjusting only dielectric properties, the phase-field model describes this emergent phase as a photo-induced charge-stabilized supercrystal formed from a two-phase equilibrium state. Our results demonstrate opportunities for light-activated pathways to thermally inaccessible and emergent metastable states.

Three Phase-Grating Moiré Neutron Interferometer for Large Interferometer Area Applications

We demonstrate a three phase-grating moiré neutron interferometer in a highly intense neutron beam as a robust candidate for large area interferometry applications and for the characterization of materials. This novel far-field moiré technique allows for broad wavelength acceptance and relaxed requirements related to fabrication and alignment, thus circumventing the main obstacles associated with perfect crystal neutron interferometry. We observed interference fringes with an interferometer length of 4 m and examined the effects of an aluminum 6061 alloy sample on the coherence of the system. Experiments to measure the autocorrelation length of samples and the universal gravitational constant are proposed and discussed.

Abstract PD1-15: The landscape of somatic genetic alterations in breast cancers from ATM germline mutation carriers

Introduction:Pathogenic and/or founder germline variants in the ataxia-telangiectasia mutated (ATM) gene confer an increased breast cancer (BC) risk. The protein kinase ATM plays a central role inDNA double-strand break-repair and in the activation of downstream targets such as p53 and BRCA1. We sought to define the repertoire of somatic genetic alterations of BCs from patients with pathogenic germline ATM mutations and whether somatic loss of heterozygosity (LOH) of ATM would be present in these cancers.

Methods: 21 BCs from ATM germline mutation carriers were microdissected. Tumor and normal DNA samples were subjected to whole-exome sequencing (WES, n=12) or massively parallel sequencing targeting all coding regions and selected intronic and regulatory regions of 410 key cancer genes (n=9). Somatic mutations, copy number alterations, cancer cell fractions, large-scale state transitions (LSTs) and mutational signatures were defined using state-of-the-art bioinformatics algorithms. ABSOLUTE and FACETS were employed to assess LOH of the wild-type allele of ATM.

Results: Of the patients included in this study, 71%, 24% and 5% of cases harbored ATM missense (all but one p.V2424G), frame-shift and nonsense germline mutations, respectively. All tumors were ER-positive and four (19%) were HER2-positive. The median age of the patients was 46 years (32–79 years). Our analyses revealed biallelic inactivation of ATM through LOH of the wild-type allele in 16 of 21 cases (76%), and second somatic ATM mutations were not found. The median number of non-synonymous somatic mutations was 38 (range 15-113) and 2 (range 0-8)in tumors subjected to WES and targeted sequencing, respectively. The repertoire of somatic genetic alterations of ATM-associated BCs was found to be heterogeneous, including clonal PIK3CA mutations (24%), GATA3 mutations (19%), FANCI amplifications (19%) and CCND1 amplifications (14%). Importantly, however, no somatic mutations affecting TP53 were found. Analysis of the WES data revealed that 5 (42%) ATM-associated BCs displayed high LST scores, all of which harbored bi-allelic ATM inactivation. In contrast to BRCA1- and BRCA2-associated BCs, which frequently display the mutational signature 3 associated with defective homologous recombination DNA repair, the ATM-associated BCs studied displayed the ageing mutational signature (i.e. signature 1). Comparison of the mutational profiles of the ATM--associated BCs subjected to WES (n=12) with those of BRCA1- (n=11) and BRCA2-associated (n=10) BCs from The Cancer Genome Atlas revealed that TP53 was more frequently mutated in BCs from BRCA1 germline mutation carriers (0% vs 72%, P&lt;0.001), while no differences with BRCA2-associated BCs were found.

Conclusion: ATM-associated BCs frequently display bi-allelic ATM inactivation through LOH of the wild-type allele and a subset of these cases displayed high levels of LSTs. These findings suggest that at least in a subset of ATM-associated BCs, biallelic inactivation of ATM rather than a dominant negative effect of the germline mutation may be the mechanism of inactivation of this tumor suppressor gene. The repertoire of somatic genetic alterations of ATM-associated BCs is heterogeneous, with a noticeable lack of TP53 somatic mutations.

Citation Format: Weigelt B, Bi R, Kumar R, James PA, Thorne H, Couch FJ, Eccles DM, Blows F, Geyer FC, Li A, Selenica P, Lim RS, Blecua P, Shen R, Wen H, Robson ME, Reis-Filho JS, Chenevix-Trench G. The landscape of somatic genetic alterations in breast cancers from ATM germline mutation carriers [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD1-15.

Integrating In Vitro, Modeling, and In Vivo Approaches to Investigate Warfarin Bioequivalence

We demonstrate the use of modeling and simulation to investigate bioequivalence (BE) concerns raised about generic warfarin products. To test the hypothesis that the loss of isopropyl alcohol and slow dissolution in acidic pH has significant impact on the pharmacokinetics of warfarin sodium tablets, we conducted physiologically based pharmacokinetic absorption modeling and simulation using formulation factors or in vitro dissolution profiles as input parameters. Sensitivity analyses indicated that warfarin pharmacokinetics was not sensitive to solubility, particle size, density, or dissolution rate in pH 4.5, but was affected by dissolution rate in pH 6.8 and potency. Virtual BE studies suggested that stressed warfarin sodium tablets with slow dissolution rate in pH 4.5 but having similar dissolution rate in pH 6.8 would be bioequivalent to the unstressed warfarin sodium tablets. A four‐way, crossover, single‐dose BE study in healthy subjects was conducted to test the same hypothesis and confirmed the simulation conclusion.

[Epidemiological analysis of GJB2,SLC26A4,mtRNA,GJB3 in nonsyndromic hearing loss in Kashi in Xinjiang]

Objective:To investigate the epidemiological analysis of the GJB2,SLC26A4,mtRNA and GJB3 gene in nonsyndromic hearing loss in Kashi in Xinjiang.Method:In this study, we analyzed the mutations of GJB2, SLC26A4, mitochondrial mtRNA and GJB3 gene mutations in 629 cases of patients with nonsyndromic hearing loss in Kashi in Xinjiang by using the gene kit. Result:The proportion of GJB2 gene mutation was 60.29%（41/68）, the SLC26A4 and mtRNA were 8.82%（6/68）and 30.88%（21/68）respectively. Conclusion:GJB2 gene, SLC26A4, mtRNA gene are common cause of nonsyndromic hearing loss in Xinjiang.

Identification of early diagnostic antigens in soluble proteins of Trichinella spiralis adult worms by Western blot

Previous studies showed that crude antigens from Trichinella spiralis adult worms (AW) can be recognized by mouse infection sera at 8 days post infection. The aim of this study was to identify the early diagnostic antigenic bands in soluble proteins from T. spiralis AW by Western blot using early infection sera. The affecting factors of adult recovery were firstly observed in this study, and the results showed that the maximum number of adults was collected from small intestine when the female BALB/c mice were orally infected with 4000 ML and sacrificed at 3 days post infection. The results of Western blot analysis showed that seven protein bands (31, 35.1, 39, 40.6, 41.9, 47 and 50.6 kDa) could be recognized by early infection sera as early as at 8-10 days post infection, and were strongly reacted with mouse infection sera at 11-12 days post infection. Our results suggested that the seven protein bands of T. spiralis AW soluble proteins might be the early expressed antigens during the intestinal stage of Trichinella infection and therefore have potential value for the early diagnosis of trichinellosis.

[Systematic review of feasibility, safety and efficacy of ex situ liver resection and autotransplantation]

OBJECTIVE

To evaluate the feasibility, safety and efficiency of ex situ liver resection (ESLR)technique in patients with hepatocaval region involvement.

METHODS

A systematic research of the data bases CNKI, Wan Fang, CQVIP, PubMed, CENTRAL, Medline, Embase, Cochrane, International Clinical Transplantation Registration Platform and Transplant Library was performed. All the current data regarding the feasibility, safety, and oncological efficiency of ESLR was systematically reviewed. Feasibility, conversion to allo-transplantation rate, complication and 90-day mortality were analyzed.

RESULTS

A literature search revealed a total of 46 publications with 191 patients who underwent ex situ liver resection (101 autotransplantation, 90 ante-situm liver resection). The most common indication was hepatocellular carcinoma (49), followed by colorectal liver metastasis (37), hepatic alveolar echinococcosis (33) and cholangiocarcinoma (26). The feasibility rate was 84.5% (CI=76.6%-90.1%), the conversion to allo-transplantation rate was 13.5% (CI=8.5%-21.0%). Overall complication rate was 58.1% (CI=48.5%-67.1%), and complications grade Ⅲa or higher occurred in 43.1% (CI=33.6%-53.1%).90-day mortality was 19.5% (CI=12.7%-28.8%).

CONCLUSION

ESLR and autotransplantation technique is an effective surgical approach for hepatic tumor with hepatocaval region involvement. Strict control of surgical indications, preoperative evaluation and precise surgical technique is essential to success.

Clinical motivation and the surgical safety checklist

Background

Although the surgical safety checklist (SSC) has been adopted worldwide, its efficacy can be diminished by poor clinical motivation. Systematic methods for improving implementation are lacking.

Methods

A multicentre prospective study was conducted in 2015 in four academic/teaching hospitals to investigate changes during revision of the SSC for content, staffing and workflow. All modifications were based on feedback from medical staff. Questionnaires were used to monitor dynamic changes in surgeons', nurses' and anaesthetists' perceptions.

Results

Complete information was obtained from 30 654 operations in which the newly developed SSC system was used. Implementation quality was evaluated in 1852 operations before, and 1822 after the changes. The revised SSC content was simplified from 34 to 22 items. Anaesthetists achieved widespread recommendation as SSC coordinators. Completion rates of all stages reached over 80·0 per cent at all sites (compared with 10·2–59·5 per cent at the sign-out stage in the baseline survey). There was a significant change in doctors who participated (for example, surgeon: from 24·6 to 64·5 per cent at one site). The rates of hasty (15·1–33·7 per cent) or casual (0·4–4·4 per cent) checking decreased to less than 6·0 per cent overall. Perceptions about the SSC were studied from 2211 forms. They improved, with a converging trend among the three different professions, to a uniform 80·0 per cent agreeing on the need for its regular use.

Conclusion

Medical staff members are both the users and owners of the SSC. High-quality SSC implementation can be achieved by clinically motivated adaptation.

[The clinical practice of improvement the "Volume and Quality" of functional liver in autologous liver transplantation for the patients with alveolar echinococcosis]

Objective: To investigate the clinical significance of accurate assessment of "volume and quality" of functional liver in Autologous liver transplantation (ALT) in the treatment of the advanced hepatic alveolar echinococcosis (HAE). Methods: The clinical data of 12 patients with advanced HAE who underwent ALT at the First Affiliated Hospital of Xinjiang Medical University from May 2015 to July 2016 were retrospectively analyzed. Results: The preoperative hepatic functions of 12 patients were 8 Child-Pugh Grade A, 1 Grade B, and 3 Grade C. Three of the patients had moderate or severe jaundice. Three of the patients calculated functional liver graft volume (GV) and standard liver volume (SLV) ratio (GV/SLV) were <30%. After the protection of liver function, anti-infection, percutaneous transhepatic cholangiography drainage (PTCD), selective portal vein embolization (PVE), and staging liver resection, liver function Child-Pugh grade of 11 patients was raised to A grade, and the other patient was B grade, meanwhile the bilirubin was reduced to 2 times the normal value. The GV/SLV ratios of 3 patients with low GV/SLV ratio had reached 44.4%, 47.2% and 56.2% respectively. In this study, the GV/SLV ratios of the 12 patients were between 73.2% and 40.8% with an average of 55.6%. Operation time was 11.5-20.5 h, with an average of 12.3 h. Anhepatic phase time was 193-375 min with median 253.5 min. The red blood cell suspension was 0-6 U during the operation. The average hospitalization was 10-42 d, with the average 22.7 d. Total hospital costs were 121 600-434 800 Yuan, with the median cost of 174 400 Yuan. One patient died of septic shock a week after surgery. Conclusion: (1)ALT may provide feasibility for the advanced HAE. (2)Accurate assessment of functional liver "volume and quality" appeared as the key points to the ALT. (3)Precise surgery and individualized treatment could improve and protect the functional liver "volume and quality" .