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Air dispersal of multi-drug-resistant organisms including meticillin-resistant Staphylococcus aureus, carbapenem-resistant Acinetobacter baumannii and carbapenemase-producing Enterobacterales in general wards: surveillance culture of air grilles. J Hosp Infect 2024; 149:26-35. [PMID: 38705476 DOI: 10.1016/j.jhin.2024.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 04/07/2024] [Accepted: 04/08/2024] [Indexed: 05/07/2024]
Abstract
BACKGROUND The environmental surveillance of air grilles in clinical areas has not been systematically analysed. METHODS Samples were collected from frequently touched items (N = 529), air supply (N = 295) and exhaust (N = 184) grilles in six medical and 11 surgical wards for the cultures of multi-drug-resistant organisms (MDROs): meticillin-resistant Staphylococcus aureus (MRSA), carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenemase-producing Enterobacterales (CPE), and isolates were selected for whole-genome sequencing (WGS). The contamination rates were correlated with the colonization pressures of the respective MDROs. RESULTS From 3rd October to 21st November 2023, 9.8% (99/1008) of the samples tested positive, with MRSA (24.2%, 24/99), CRAB (59.6%, 59/99) and CPE (2.0%, 2/99), being the only detected MDROs. The contamination rate in air exhaust grilles (26.6%, 49/184) was significantly higher than in air supply grilles (5.8%, 17/295; P<0.001). The contamination rate of air exhaust grilles with any MDRO in acute medical wards (73.7%, 14/19) was significantly higher than in surgical wards (12.5%, 4/32; P<0.001). However, there was no difference in the contamination rate of air exhaust grilles between those located inside and outside the cohort cubicles for MDROs (27.1%, 13/48 vs 28.8%, 30/104; P=0.823). Nevertheless, the weekly CRAB colonization pressure showed a significant correlation with the overall environmental contamination rate (r = 0.878; 95% confidence interval (CI): 0.136-0.986; P=0.004), as well as with the contamination rate in air supply grilles (r = 0.960; 95% CI: 0.375-0.999; P<0.001) and air exhaust grilles (r = 0.850; 95% CI: 0.401-0.980; P=0.008). WGS demonstrated clonal relatedness of isolates collected from patients and air exhaust grilles. CONCLUSIONS Air grilles may serve as MDRO reservoirs. Cohort nursing in open cubicles may not completely prevent MDRO transmission through air dispersal, prompting the consideration of future hospital design.
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[Clinical outcome of posterior lumbar interbody fusion combined with Ponte osteotomy for reconstruction of coronal sagittal plane balance in degenerative scoliosis]. ZHONGHUA YI XUE ZA ZHI 2024; 104:1043-1049. [PMID: 38561299 DOI: 10.3760/cma.j.cn112137-20231015-00753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Objective: To evaluate the clinical efficacy of posterior lumbar interbody fusion combined with Ponte osteotomy in the treatment of patients with degenerative scoliosis. Methods: The medical records and imaging data of degenerative scoliosis in department of orthopedics, Peking Union Medical College Hospital from 2013 to 2022 were retrospectively collected, and the shortest follow-up time was 1 year. A total of 38 patients were included, including 13 males and 25 females, aged 50-87(65.6±10.9) years old.The follow-up was12-119(43±20) months. Standing position full spine anteroposterior lateral X-ray examinations were performed on all patients preoperatively, postoperatively, and at latest follow-up. The length of hospital stay, complications, operation time, blood loss, instrumented segment, fusion segmen were recorded. The clinical scores and coronasagittal imaging indicators at three time points were compared. Results: The operation time was (274.5±70.5)min, and intraoperative blood loss was (619.2±93.5)ml. The coronal vertical axis was improved from (2.9±1.8)cm preoperatively to (1.2±1.0)cm postoperatively. The preoperative coronal Cobb angle was 16.6°±9.9° and the immediate postoperative correction was 6.4°±4.0°(t=-6.83, P<0.001). The difference was statistically significant (t=-6.12, P<0.001). The coronal Cobb Angle at the last follow-up was 5.7°±3.7°, and there was no significant orthopaedic loss at the last follow-up (t=-6.12, P<0.001).The sagittal vertical axis decreased from (5.6±3.9)cm preoperatively to (3.2±2.5) cm immediately after operation (t=-6.83,P<0.001), and was well maintained at the last follow-up[(2.7±1.8) cm,t=-7.77,P<0.001]. Lumbar lordosis increased from 21.8°±10.2° preoperatively to 35.8°±8.3° postoperatively(t=12.01, P<0.001)and 40.1°±8.6° at last follow-up(t=-10.21, P<0.001). Oswestry disability score (ODI score), visual analogue score (VAS) low back pain score and VAS leg pain score were also lower after surgery than before surgery (all P<0.05). Conclusion: Posterior lumbar interbody fusion combined with Ponte osteotomy can significantly improve the coronal and sagittal plane deformity and postoperative functional score in adult patients with degenerative scoliosis.
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Exploration of clinical and ethical issues in an expanded newborn metabolic screening programme: a qualitative interview study of healthcare professionals in Hong Kong. Hong Kong Med J 2024; 30:120-129. [PMID: 38590159 DOI: 10.12809/hkmj2210234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024] Open
Abstract
INTRODUCTION The Newborn Screening Programme for Inborn Errors of Metabolism (NBSIEM) enables early intervention and prevents premature mortality. Residual dried bloodspots (rDBS) from the heel prick test are a valuable resource for research. However, there is minimal data regarding how stakeholders in Hong Kong view the retention and secondary use of rDBS. This study aimed to explore views of the NBSIEM and the factors associated with retention and secondary use of rDBS among healthcare professionals in Hong Kong. METHODS Between August 2021 and January 2022, semi-structured interviews were conducted with 30 healthcare professionals in obstetrics, paediatrics, and chemical pathology. Key themes were identified through thematic analysis, including views towards the current NBSIEM and the retention and secondary use of rDBS. RESULTS After implementation of the NBSIEM, participants observed fewer patients with acute decompensation due to undiagnosed inborn errors of metabolism. The most frequently cited clinical utilities were early detection and improved health outcomes. Barriers to rDBS storage and its secondary use included uncertain value and benefits, trust concerns, and consent issues. CONCLUSION This study highlighted healthcare professionals' concerns about the NBSIEM and uncertainties regarding the handling or utilisation of rDBS. Policymakers should consider these concerns when establishing new guidelines.
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Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment. PHYSICAL REVIEW LETTERS 2024; 132:065102. [PMID: 38394591 DOI: 10.1103/physrevlett.132.065102] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 01/03/2024] [Indexed: 02/25/2024]
Abstract
On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.
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Experimental Evidence of Plasmoids in High-β Magnetic Reconnection. PHYSICAL REVIEW LETTERS 2024; 132:035101. [PMID: 38307081 DOI: 10.1103/physrevlett.132.035101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 10/27/2023] [Accepted: 12/07/2023] [Indexed: 02/04/2024]
Abstract
Magnetic reconnection is a ubiquitous and fundamental process in plasmas by which magnetic fields change their topology and release magnetic energy. Despite decades of research, the physics governing the reconnection process in many parameter regimes remains controversial. Contemporary reconnection theories predict that long, narrow current sheets are susceptible to the tearing instability and split into isolated magnetic islands (or plasmoids), resulting in an enhanced reconnection rate. While several experimental observations of plasmoids in the regime of low-to-intermediate β (where β is the ratio of plasma thermal pressure to magnetic pressure) have been made, there is a relative lack of experimental evidence for plasmoids in the high-β reconnection environments which are typical in many space and astrophysical contexts. Here, we report strong experimental evidence for plasmoid formation in laser-driven high-β reconnection experiments.
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Effect of the tyrosine kinase inhibitors on the growth in children with Philadelphia chromosome-positive acute lymphoblastic leukemia: a case-control study. THE LANCET REGIONAL HEALTH. WESTERN PACIFIC 2023; 38:100818. [PMID: 37790080 PMCID: PMC10544282 DOI: 10.1016/j.lanwpc.2023.100818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/10/2023] [Accepted: 05/24/2023] [Indexed: 10/05/2023]
Abstract
Background First-generation ABL-targeted tyrosine kinase inhibitor (TKI) imatinib is known to retard growth in children but it is not known if the second-generation ABL-targeted TKI dasatinib has the same effect. We aimed to determine the impact of the first- or second-generation TKI on the growth of children treated for Philadelphia chromosome-positive (Ph+) childhood acute lymphoblastic leukemia (ALL). Methods We evaluated the longitudinal growth changes in 140 children with Ph+ ALL treated with imatinib or dasatinib in additional to intensive cytotoxic chemotherapy and 280 matched controls treated with the same intensity of cytotoxic chemotherapy without TKI on Chinese Children's Cancer Group ALL-2015 protocol between 2015 and 2019. We retrospectively reviewed the height data obtained during routine clinic visits at 4 time points: at diagnosis, the end of therapy, 1 year and 2 years off therapy. Height z Scores were derived with the aid of WHO Anthro version 3.2.2 and WHO AnthroPlus version 1.0.4, global growth monitoring tool. Findings This study consisted only patients who have completed all treatment in continuous complete remission without major events, including 33 patients randomized to receive imatinib, 43 randomized to receive dasatinib, and 64 assigned to receive dasatinib. Similar degree of loss of height z scores from diagnosis to the end of therapy was observed for the 33 imatinib- and the 107 dasatinib-treated patients (median △ = -0.84 vs. -0.88, P = 0.41). Adjusting for height z score at diagnosis, puberty status, and sex, there was no significant difference in the longitudinal mean height z scores between patients treated with imatinib and those with dasatinib (0.08, 95% CI, -0.22 to 0.38, P = 0.60). The degree of loss of height z scores from diagnosis to end of therapy was significantly greater in the 140 TKI-treated patients than the 280 controls (median △ = -0.88 vs. -0.18, P < 0.001). The longitudinal mean height z scores in the TKI-treated patients were significantly lower than those of the controls (-0.84, 95% CI, -0.98 to -0.69; P < 0.001). Interpretation These data suggest that dasatinib and imatinib have the similar adverse impact on the growth of children with Ph+ ALL. Funding This study was supported by the National Natural Science Foundation of China (grant 81670136 [JCai and JT]), the fourth round of Three-Year Public Health Action Plan (2015-2017; GWIV-25 [SS]), Shanghai Health Commission Clinical Research Project (202140161 [JCai]), the US National Cancer institute (CA21765 [C-H Pui]), and the American Lebanese Syrian Associated Charities (CC, JJY, and C-HP). The content of this paper is solely the responsibility of the authors and does not necessarily represent the official views of the US National Institutes of Health.
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Laser-direct-drive fusion target design with a high-Z gradient-density pusher shell. Phys Rev E 2023; 108:035209. [PMID: 37849111 DOI: 10.1103/physreve.108.035209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/05/2023] [Indexed: 10/19/2023]
Abstract
Laser-direct-drive fusion target designs with solid deuterium-tritium (DT) fuel, a high-Z gradient-density pusher shell (GDPS), and a Au-coated foam layer have been investigated through both 1D and 2D radiation-hydrodynamic simulations. Compared with conventional low-Z ablators and DT-push-on-DT targets, these GDPS targets possess certain advantages of being instability-resistant implosions that can be high adiabat (α≥8) and low hot-spot and pusher-shell convergence (CR_{hs}≈22 and CR_{PS}≈17), and have a low implosion velocity (v_{imp}<3×10^{7}cm/s). Using symmetric drive with laser energies of 1.9 to 2.5MJ, 1D lilac simulations of these GDPS implosions can result in neutron yields corresponding to ≳50-MJ energy, even with reduced laser absorption due to the cross-beam energy transfer (CBET) effect. Two-dimensional draco simulations show that these GDPS targets can still ignite and deliver neutron yields from 4 to ∼10MJ even if CBET is present, while traditional DT-push-on-DT targets normally fail due to the CBET-induced reduction of ablation pressure. If CBET is mitigated, these GDPS targets are expected to produce neutron yields of >20MJ at a driven laser energy of ∼2MJ. The key factors behind the robust ignition and moderate energy gain of such GDPS implosions are as follows: (1) The high initial density of the high-Z pusher shell can be placed at a very high adiabat while the DT fuel is maintained at a relatively low-entropy state; therefore, such implosions can still provide enough compression ρR>1g/cm^{2} for sufficient confinement; (2) the high-Z layer significantly reduces heat-conduction loss from the hot spot since thermal conductivity scales as ∼1/Z; and (3) possible radiation trapping may offer an additional advantage for reducing energy loss from such high-Z targets.
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Current Challenges of Asian National Children's Cancer Study Groups on Behalf of Asian Pediatric Hematology and Oncology Group. JCO Glob Oncol 2023; 9:e2300153. [PMID: 37656946 PMCID: PMC10581612 DOI: 10.1200/go.23.00153] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 07/06/2023] [Accepted: 07/19/2023] [Indexed: 09/03/2023] Open
Abstract
In Asia, a few countries have a long and established history of collaborative clinical trials successfully formed national children's cancer study groups, but many still do not have such groups. The process of forming national children's cancer groups is fraught with many hurdles, which varies among the countries. One of the basic requirements for running clinical trials is an affordable health care system in which most of the children with cancer can receive the proposed treatment. The health insurance coverage for children with cancer varies from <20% to as high as 100% among Asian countries, and the operation of clinical trials must also be adjusted accordingly. Shortage of research personnel is common, including medical, nursing, research coordinators, and data managers. The establishment of the Asian Pediatric Hematology and Oncology Group aims to provide a good platform for promotion of international clinical trials in the Asian countries.
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Determining spectral response of the National Ignition Facility particle time of flight diagnostic to x rays. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:033510. [PMID: 37012781 DOI: 10.1063/5.0101725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 02/28/2023] [Indexed: 06/19/2023]
Abstract
The Particle Time of Flight (PTOF) diagnostic is a chemical vapor deposition diamond detector used for measuring multiple nuclear bang times at the National Ignition Facility. Due to the non-trivial, polycrystalline structure of these detectors, individual characterization and measurement are required to interrogate the sensitivity and behavior of charge carriers. In this paper, a process is developed for determining the x-ray sensitivity of PTOF detectors and relating it to the intrinsic properties of the detector. We demonstrate that the diamond sample measured has a significant non-homogeneity in its properties, with the charge collection well described by a linear model ax + b, where a = 0.63 ± 0.16 V-1 mm-1 and b = 0.00 ± 0.04 V-1. We also use this method to confirm an electron to hole mobility ratio of 1.5 ± 1.0 and an effective bandgap of 1.8 eV rather than the theoretical 5.5 eV, leading to a large sensitivity increase.
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Solitary fibrous tumor of the lacrimal sac: A case report and review of the literature. J Fr Ophtalmol 2023; 46:e21-e24. [PMID: 36496292 DOI: 10.1016/j.jfo.2022.06.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 06/20/2022] [Indexed: 12/12/2022]
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Blinatumomab with donor lymphocyte infusions post haploidentical hematopoietic stem cell transplantation as salvage therapy for relapsed refractory acute lymphoblastic leukemia post chimeric antigen receptor T-cell therapy. Pediatr Blood Cancer 2023; 70:e29852. [PMID: 35727716 DOI: 10.1002/pbc.29852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/24/2022] [Accepted: 06/05/2022] [Indexed: 12/25/2022]
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Paediatric high-grade osteosarcoma and its prognostic factors: a 10-year retrospective study. Hong Kong Med J 2022; 28:447-456. [PMID: 36423912 DOI: 10.12809/hkmj209210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
INTRODUCTION This retrospective study was conducted to identify the characteristics of paediatric high-grade osteosarcoma and define its prognostic factors. METHODS We identified paediatric patients (aged <19 years at diagnosis) diagnosed with high-grade osteosarcoma from 1 January 2009 to 31 December 2018 in two hospitals in Hong Kong, then retrospectively evaluated their medical records to identify prognostic factors. RESULTS In total, 52 patients were included in this study (22 girls, 42.3%). Femoral tumour was the most common form of osteosarcoma. Most patients (78.8%) had localised disease at diagnosis. The lung was the most common site of metastasis. Almost half (n=23, 46.9%) of the patients showed a good response to chemotherapy (ie, chemonecrosis >90%). Most patients (n=40, 80%) underwent limb-salvage surgery. The event-free survival and overall survival rates were 55.8% and 71.2%, respectively. Prognostic factors independently associated with poor event-free survival and poor overall survival were the presence of metastasis at diagnosis, poor tumour chemonecrosis, and the need for amputation. CONCLUSION This multicentre review of paediatric high-grade osteosarcoma showed that the baseline patient demographics, event-free survival, and overall survival in Hong Kong were similar to previous findings in other countries. Patients with metastatic disease at diagnosis and poor chemonecrosis had worse survival outcomes. Molecular analyses of genetic abnormalities may help to identify targeted therapies in future studies.
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Pharmacogenomic Profiling of Pediatric Acute Myeloid Leukemia to Identify Therapeutic Vulnerabilities and Inform Functional Precision Medicine. Blood Cancer Discov 2022; 3:516-535. [PMID: 35960210 PMCID: PMC9894568 DOI: 10.1158/2643-3230.bcd-22-0011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 05/31/2022] [Accepted: 08/09/2022] [Indexed: 11/16/2022] Open
Abstract
Despite the expanding portfolio of targeted therapies for adults with acute myeloid leukemia (AML), direct implementation in children is challenging due to inherent differences in underlying genetics. Here we established the pharmacologic profile of pediatric AML by screening myeloblast sensitivity to approved and investigational agents, revealing candidates of immediate clinical relevance. Drug responses ex vivo correlated with patient characteristics, exhibited age-specific alterations, and concorded with activities in xenograft models. Integration with genomic data uncovered new gene-drug associations, suggesting actionable therapeutic vulnerabilities. Transcriptome profiling further identified gene-expression signatures associated with on- and off-target drug responses. We also demonstrated the feasibility of drug screening-guided treatment for children with high-risk AML, with two evaluable cases achieving remission. Collectively, this study offers a high-dimensional gene-drug clinical data set that could be leveraged to research the unique biology of pediatric AML and sets the stage for realizing functional precision medicine for the clinical management of the disease. SIGNIFICANCE We conducted integrated drug and genomic profiling of patient biopsies to build the functional genomic landscape of pediatric AML. Age-specific differences in drug response and new gene-drug interactions were identified. The feasibility of functional precision medicine-guided management of children with high-risk AML was successfully demonstrated in two evaluable clinical cases. This article is highlighted in the In This Issue feature, p. 476.
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X-ray-imaging spectrometer (XRIS) for studies of residual kinetic energy and low-mode asymmetries in inertial confinement fusion implosions at OMEGA (invited). THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:113540. [PMID: 36461452 DOI: 10.1063/5.0101655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 09/05/2022] [Indexed: 06/17/2023]
Abstract
A system of x-ray imaging spectrometer (XRIS) has been implemented at the OMEGA Laser Facility and is capable of spatially and spectrally resolving x-ray self-emission from 5 to 40 keV. The system consists of three independent imagers with nearly orthogonal lines of sight for 3D reconstructions of the x-ray emission region. The distinct advantage of the XRIS system is its large dynamic range, which is enabled by the use of tantalum apertures with radii ranging from 50 μm to 1 mm, magnifications of 4 to 35×, and image plates with any filtration level. In addition, XRIS is capable of recording 1-100's images along a single line of sight, facilitating advanced statistical inference on the detailed structure of the x-ray emitting regions. Properties such as P0 and P2 of an implosion are measured to 1% and 10% precision, respectively. Furthermore, Te can be determined with 5% accuracy.
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Measurements of ion-electron energy-transfer cross section in high-energy-density plasmas. Phys Rev E 2022; 106:L053201. [PMID: 36559377 DOI: 10.1103/physreve.106.l053201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 09/02/2022] [Indexed: 06/17/2023]
Abstract
We report on measurements of the ion-electron energy-transfer cross section utilizing low-velocity ion stopping in high-energy-density plasmas at the OMEGA laser facility. These measurements utilize a technique that leverages the close relationship between low-velocity ion stopping and ion-electron equilibration. Shock-driven implosions of capsules filled with D^{3}He gas doped with a trace amount of argon are used to generate densities and temperatures in ranges from 1×10^{23} to 2×10^{24} cm^{-3} and from 1.4 to 2.5 keV, respectively. The energy loss of 1-MeV DD tritons and 3.7-MeV D^{3}He alphas that have velocities lower than the average velocity of the thermal electrons is measured. The energy loss of these ions is used to determine the ion-electron energy-transfer cross section, which is found to be in excellent agreement with quantum-mechanical calculations in the first Born approximation. This result provides an experimental constraint on ion-electron energy transfer in high-energy-density plasmas, which impacts the modeling of alpha heating in inertial confinement fusion implosions, magnetic-field advection in stellar atmospheres, and energy balance in supernova shocks.
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In situ calibration of charged particle spectrometers on the OMEGA Laser Facility using 241Am and 226Ra sources. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:113534. [PMID: 36461490 DOI: 10.1063/5.0099752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 09/06/2022] [Indexed: 06/17/2023]
Abstract
Charged particle spectrometry is a critical diagnostic to study inertial-confinement-fusion plasmas and high energy density plasmas. The OMEGA Laser Facility has two fixed magnetic charged particle spectrometers (CPSs) to measure MeV-ions. In situ calibration of these spectrometers was carried out using 241Am and 226Ra alpha emitters. The alpha emission spectrum from the sources was measured independently using surface-barrier detectors (SBDs). The energy dispersion and broadening of the CPS systems were determined by comparing the CPS measured alpha spectrum to that of the SBD. The calibration method significantly constrains the energy dispersion, which was previously obtained through the measurement of charged particle fusion products. Overall, a small shift of 100 keV was observed between previous and the calibration done in this work.
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Extended vincristine and dexamethasone pulse therapy may not be necessary for children with TCF3-PBX1 positive acute lymphoblastic leukaemia. Br J Haematol 2022; 199:587-596. [PMID: 36114009 PMCID: PMC9649883 DOI: 10.1111/bjh.18437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/17/2022] [Accepted: 08/17/2022] [Indexed: 11/30/2022]
Abstract
The effect of prolonged pulse therapy with vincristine and dexamethasone (VD) during maintenance therapy on the outcome of paediatric patients with TCF3-PBX1 positive acute lymphoblastic leukaemia (ALL) remains uncertain. We conducted non-inferiority analysis of 263 newly diagnosed TCF3-PBX1 positive ALL children who were stratified and randomly assigned (1:1) to receive seven additional VD pulses (the control group) or not (the experimental group) in the CCCG-ALL-2015 clinical trial from January 2015 to December 2019 (ChiCTR-IPR-14005706). There was no significant difference in baseline characteristics between the two groups. With a median follow-up of 4.2 years, the 5-year event-free survival (EFS) and 5-year overall survival (OS) in the control group were 90.1% (95% confidence interval [CI] 85.1-95.4) and 94.7% (95% CI, 90.9-98.6) comparable to those in the experimental group 89.2% (95% CI 84.1-94.7) and 95.6% (95% CI 91.8-99.6), respectively. Non-inferiority was established as a one-sided 95% upper confidence bound for the difference in probability of 5-year EFS was 0.003, and that for 5-year OS was 0.01 by as-treated analysis. Thus, omission of pulse therapy with VD beyond one year of treatment did not affect the outcome of children with TCF3-PBX1 positive ALL.
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Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment. PHYSICAL REVIEW LETTERS 2022; 129:075001. [PMID: 36018710 DOI: 10.1103/physrevlett.129.075001] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 06/24/2022] [Accepted: 07/06/2022] [Indexed: 06/15/2023]
Abstract
For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.
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Outcomes of adolescents with acute lymphoblastic leukaemia. Hong Kong Med J 2022; 28:204-214. [PMID: 35697524 DOI: 10.12809/hkmj208914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023] Open
Abstract
INTRODUCTION Compared with young children who have acute lymphoblastic leukaemia (ALL), adolescents with ALL have unfavourable disease profiles and worse survival. However, limited data are available regarding the characteristics and outcomes of adolescents with ALL who underwent treatment in clinical trials. The aim of this study was to investigate the causes of treatment failure in adolescents with ALL. METHODS We retrospectively analysed the outcomes of 711 children with ALL, aged 1-18 years, who were enrolled in five clinical trials of paediatric ALL treatment between 1993 and 2015. RESULTS Among the 711 children with ALL, 530 were young children (1-9 years at diagnosis) and 181 were adolescents (including 136 younger adolescents [10-14 years] and 45 older adolescents [15-18 years]). Compared with young children who had ALL, adolescents with ALL were less likely to have favourable genetic features and more likely to demonstrate poor early response to treatment. The 10-year overall survival and event-free survival rates were significantly lower among adolescents than among young children (77.9% vs 87.6%, P=0.0003; 69.7% vs 76.5%, P=0.0117). There were no significant differences in the 10-year cumulative incidence of relapse, but the 10-year cumulative incidence of treatment-related death (TRD) was significantly greater among adolescents (7.2%) than among young children (2.3%; P=0.002). Multivariable analysis showed that both younger and older adolescents (vs young children) had worse survival and greater incidence of TRD. CONCLUSION Adolescents with ALL had worse survival because they experienced a greater incidence of TRD. There is a need to investigate optimal treatment adjustments and novel targeted agents to achieve better survival rates (without excessive toxicity) among adolescents with ALL.
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Experiments on the dynamics and scaling of spontaneous-magnetic-field saturation in laser-produced plasmas. Phys Rev E 2022; 105:L063202. [PMID: 35854613 DOI: 10.1103/physreve.105.l063202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 05/16/2022] [Indexed: 06/15/2023]
Abstract
In laser-produced high-energy-density plasmas, large-scale strong magnetic fields are spontaneously generated by the Biermann battery effects when temperature and density gradients are misaligned. Saturation of the magnetic field takes place when convection and dissipation balance field generation. While theoretical and numerical modeling provide useful insight into the saturation mechanisms, experimental demonstration remains elusive. In this letter, we report an experiment on the saturation dynamics and scaling of Biermann battery magnetic field in the regime where plasma convection dominates. With time-gated charged-particle radiography and time-resolved Thomson scattering, the field structure and evolution as well as corresponding plasma conditions are measured. In these conditions, the spatially resolved magnetic fields are reconstructed, leading to a picture of field saturation with a scaling of B∼1/L_{T} for a convectively dominated plasma, a regime where the temperature gradient scale (L_{T}) exceeds the ion skin depth.
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Effect of Strongly Magnetized Electrons and Ions on Heat Flow and Symmetry of Inertial Fusion Implosions. PHYSICAL REVIEW LETTERS 2022; 128:195002. [PMID: 35622051 DOI: 10.1103/physrevlett.128.195002] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 02/24/2022] [Accepted: 03/31/2022] [Indexed: 06/15/2023]
Abstract
This Letter presents the first observation on how a strong, 500 kG, externally applied B field increases the mode-two asymmetry in shock-heated inertial fusion implosions. Using a direct-drive implosion with polar illumination and imposed field, we observed that magnetization produces a significant increase in the implosion oblateness (a 2.5× larger P2 amplitude in x-ray self-emission images) compared with reference experiments with identical drive but with no field applied. The implosions produce strongly magnetized electrons (ω_{e}τ_{e}≫1) and ions (ω_{i}τ_{i}>1) that, as shown using simulations, restrict the cross field heat flow necessary for lateral distribution of the laser and shock heating from the implosion pole to the waist, causing the enhanced mode-two shape.
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Health behaviour practices and expectations for a local cancer survivorship programme: a cross-sectional study of survivors of childhood cancer in Hong Kong. Hong Kong Med J 2022; 28:33-44. [DOI: 10.12809/hkmj209112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Thermal decoupling of deuterium and tritium during the inertial confinement fusion shock-convergence phase. Phys Rev E 2021; 104:L013201. [PMID: 34412205 DOI: 10.1103/physreve.104.l013201] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 06/23/2021] [Indexed: 11/07/2022]
Abstract
A series of thin glass-shell shock-driven DT gas-filled capsule implosions was conducted at the OMEGA laser facility. These experiments generate conditions relevant to the central plasma during the shock-convergence phase of ablatively driven inertial confinement fusion (ICF) implosions. The spectral temperatures inferred from the DTn and DDn spectra are most consistent with a two-ion-temperature plasma, where the initial apparent temperature ratio, T_{T}/T_{D}, is 1.5. This is an experimental confirmation of the long-standing conjecture that plasma shocks couple energy directly proportional to the species mass in multi-ion plasmas. The apparent temperature ratio trend with equilibration time matches expected thermal equilibration described by hydrodynamic theory. This indicates that deuterium and tritium ions have different energy distributions for the time period surrounding shock convergence in ignition-relevant ICF implosions.
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[Study of influence of birth weight on risk of chronic diseases and blood uric acid in adulthood]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 2021; 42:1213-1217. [PMID: 34814533 DOI: 10.3760/cma.j.cn112338-20200831-01112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To understand the influence of birth weight on the risk of chronic diseases, such as hypertension and diabetes, and the relationship between birth weight and serum uric acid in adulthood. Methods: According to the Chinese Adult Chronic Disease and Nutrition Surveillance Program, a total of 1 131 residents aged 18 years and above were enrolled from Hexi, Nankai, Hongqiao, Wuqing, Jinnan, Baodi and Jizhou districts of Tianjin. The data of birth weight and blood pressure of the residents were collected, and fasting venous blood samples were collected from them to detect uric acid, blood glucose and blood lipids levels. The distribution of birth weight of the surveyed population was described, and the relationship between birth weight and chronic diseases, such as hypertension and diabetes, and the blood uric acid level in adulthood were analyzed. Results: The average birth weight of the surveyed population in Tianjin was 3.37 kg, which was higher in males than in females. No matter overweight/obesity, hypertension or diabetes, the prevalence rate of normal birth weight was the lowest in adulthood. After univariate logistic regression analysis and adjusting for age, sex, smoking and drinking status, it was found that compared with normal birth weight, low birth weight had a stronger correlation with diabetes (OR=2.91,95%CI:1.46-5.76) and dyslipidemia (OR=1.79,95%CI:1.01-3.19) in adulthood. Macrosomia was strongly associated with overweight/obesity in adulthood (OR=1.47, 95%CI:1.08-2.01). There was no significant difference in serum uric acid level among the residents with different birth weights. Conclusions: The low birth weight of the surveyed population in Tianjin was closely related to the risk of diabetes and dyslipidemia in adulthood, and the macrosomia was closely related to the risk of overweight/obesity in adulthood.
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Clinical Outcome of Acquired Post-Immunosuppressive-Therapy Aplastic Anemia in Pediatric Patients: A 13-Year Experience in Two Southern China Tertiary Care Centers. Int J Gen Med 2021; 14:3133-3144. [PMID: 34239322 PMCID: PMC8259937 DOI: 10.2147/ijgm.s313898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 06/14/2021] [Indexed: 11/23/2022] Open
Abstract
Objective The aim of the present study is to evaluate the efficacy, complications, and contributing factors of immunosuppressive therapy (IST) response in children with acquired aplastic anemia (AA) and to explore optimal therapeutic methods for different clinical AA types. Methods A total of 130 children diagnosed with acquired AA underwent IST in the Department of Pediatrics at Sun Yat-sen Memorial Hospital and the Department of Pediatrics at Seventh Affiliated Hospital, Sun Yat-sen University, between January 1, 2006, and July 15, 2020. The overall survival (OS), response rates, complications, and response predictors were analyzed. The response rates were compared according to clinical AA type. Results All 130 children with AA were followed up with for a median of 50.6 months. Among the patients, 25 had non-severe AA (NSAA), 64 had severe AA (SAA), and 41 had very severe AA (VSAA). All patients initially received IST. In 13 patients, the IST failed; these patients received an allo-hematopoietic stem cell transplant as a salvage regimen. The OS rate was 90.3% ± 2.8%, and the response rates at 3, 6, 9, and 12 months were 34.19%, 39.32%, 49.57%, and 66.67%, respectively. The prolonged follow-up period might have led to higher response rates, especially in patients with SAA and VSAA. A multivariate logistic regression analysis of prognostic factors was conducted; the results showed that high red blood cell (RBC) and platelet (PLT) counts were associated with a high overall response rate and that the RBC count at diagnosis is a major contributing factor. Conclusion With the use of rabbit anti-thymocyte globulin, proper cyclosporine management, and a prolonged IST follow-up period, a higher number of patients with acquired AA than normal achieved response. Proportionally, the number of patients who achieved remission within 12 months was higher in the SAA group (38.18%→63.64%) and VSAA group (28.95%→65.79%) than in the NSAA group (58.33%→75%). Higher RBC and PLT counts at diagnosis can predict a favorable outcome.
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[Study on the diet balance index and its relationship with blood uric acid of smoking adults in Tianjin]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 2021; 42:1076-1079. [PMID: 34814510 DOI: 10.3760/cma.j.cn112338-20200806-01029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: Diet balance index (DBI_16) was used to evaluate the dietary status of smoking adults in Tianjin, and the relationship between DBI_16 and serum uric acid was analyzed. Methods: A total of 1 478 inhabitants aged 18 and above were enrolled. The dietary status was obtained with a 3-day dietary recall and condiment weighing method. And their fasting venous blood was collected to detect uric acid. Food intake and DBI_16 scores of smokers and non-smokers were described, and the relationship among smoking, diet quality distance (DQD-DBI), and serum uric acid was analyzed. Results: The intake of vegetables, fruits, and milk of smokers in Tianjin was lower than while the salt, oil, cereals, and aquatic products were higher than that of non-smokers. The DBI_16 scores of vegetables and fruits, food types, milk, and beans of smokers were lower than those of non-smokers in Tianjin, and the scores of pure energy foods and condiments were higher than those of the non-smokers. The DQD-DBI, high bound score and low bound score of smokers in Tianjin were 42.0, 14.0, and 29.0 respectively, which were all higher than those of non-smokers. The main problems appeared as moderately inadequate intake (accounting for 67.0%), low, excessive intake (accounting for 70.9%), and moderate imbalance of intake (accounting for 67.2%). The serum uric acid of smokers was higher than in the non-smokers, and there the same result appeared under the conditions of "not suitable" in DQD-DBI. Conclusions: In Tianjin, the dietary imbalance was more evident in smokers than the non-smokers, and the serum uric acid was significantly higher than the non-smokers. Strategies as strengthening the nutrition education and intervention targeted for smokers were in urgent need.
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Characterizing x-ray transmission through filters used in high energy density physics diagnostics. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:063502. [PMID: 34243553 DOI: 10.1063/5.0043770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 05/13/2021] [Indexed: 06/13/2023]
Abstract
We report on the design and implementation of a new system used to characterize the energy-dependent x-ray transmission curve, Θ(E), through filters used in high-energy density physics diagnostics. Using an Amptek X-123-CdTe x-ray spectrometer together with a partially depleted silicon surface barrier detector, both the energy spectrum and total emission of an x-ray source have been accurately measured. By coupling these detectors with a custom PROTO-XRD x-ray source with interchangeable cathodes, accurate characterizations of Θ(E) for filters of varying materials and thicknesses have been obtained. The validity of the technique has been confirmed by accurately reproducing areal densities for high-purity filters with known x-ray transmission properties. In this paper, the experimental setup is described and the results of absorption calibrations performed on a variety of different filters are presented.
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Management of Malignancies Developing in AYA. CLINICAL PEDIATRIC HEMATOLOGY-ONCOLOGY 2021. [DOI: 10.15264/cpho.2021.28.1.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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An x-ray penumbral imager for measurements of electron-temperature profiles in inertial confinement fusion implosions at OMEGA. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:043548. [PMID: 34243391 DOI: 10.1063/5.0041038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 04/03/2021] [Indexed: 06/13/2023]
Abstract
Hot-spot shape and electron temperature (Te) are key performance metrics used to assess the efficiency of converting shell kinetic energy into hot-spot thermal energy in inertial confinement fusion implosions. X-ray penumbral imaging offers a means to diagnose hot-spot shape and Te, where the latter can be used as a surrogate measure of the ion temperature (Ti) in sufficiently equilibrated hot spots. We have implemented a new x-ray penumbral imager on OMEGA. We demonstrate minimal line-of-sight variations in the inferred Te for a set of implosions. Furthermore, we demonstrate spatially resolved Te measurements with an average uncertainty of 10% with 6 μm spatial resolution.
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Yield degradation due to laser drive asymmetry in D 3He backlit proton radiography experiments at OMEGA. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:043551. [PMID: 34243410 DOI: 10.1063/5.0043004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/31/2021] [Indexed: 06/13/2023]
Abstract
Mono-energetic proton radiography is a vital diagnostic for numerous high-energy-density-physics, inertial-confinement-fusion, and laboratory-astrophysics experiments at OMEGA. With a large number of campaigns executing hundreds of shots, general trends in D3He backlighter performance are statistically observed. Each experimental configuration uses a different number of beams and drive symmetry, causing the backlighter to perform differently. Here, we analyze the impact of these variables on the overall performance of the D3He backlighter for proton-radiography studies. This study finds that increasing laser drive asymmetry can degrade the performance of the D3He backlighter. The results of this study can be used to help experimental designs that use proton radiography.
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Identifying Priorities for Harmonizing Guidelines for the Long-Term Surveillance of Childhood Cancer Survivors in the Chinese Children Cancer Group (CCCG). JCO Glob Oncol 2021; 7:261-276. [PMID: 33591820 PMCID: PMC8081494 DOI: 10.1200/go.20.00534] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/24/2020] [Accepted: 12/16/2020] [Indexed: 12/11/2022] Open
Abstract
PURPOSE Survivors of childhood cancer often experience treatment-related chronic health conditions. Given its vast population, China shares a large proportion of the global childhood cancer burden. Yet, screening and treatment of late effects in survivors of childhood cancer remain underaddressed in most regions of China. This study aimed to identify high-priority late effects for harmonizing screening guidelines within the Chinese Children's Cancer Group (CCCG), as well as barriers and enablers of the implementation of surveillance recommendations in local practice. METHODS To establish clinical consensus, 12 expert panelists who represent major institutions within the CCCG completed a Delphi survey and participated in a focus group discussion. The survey solicited ratings of the prevalence, severity, and priority for screening of 45 late effects. Major themes identified from the focus group were analyzed using thematic analysis. RESULTS The Delphi survey identified eight high-priority late effects for harmonization within CCCG: osteonecrosis, osteoporosis, left ventricular dysfunction, secondary brain tumors, treatment-related myeloid leukemia, gonadal dysfunction, growth hormone deficiency, and neurocognitive deficits. The common barriers to implementing survivorship programs include lack of support and resources for clinicians to provide follow-up care. Patients were also concerned about privacy issues and lacked awareness of late effects. Many institutions also lacked rehabilitation expertise and referral pathways. CONCLUSION By identifying obstacles related to the professional setting, patient behavior, and organization of care, our study identified resources and a framework for establishing collaborative strategies to facilitate follow-up care of childhood cancer survivors in China.
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Prognostic Value and Outcome for ETV6/RUNX1-Positive Pediatric Acute Lymphoblastic Leukemia: A Report From the South China Children's Leukemia Group. Front Oncol 2021; 11:797194. [PMID: 34988026 PMCID: PMC8722219 DOI: 10.3389/fonc.2021.797194] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/29/2021] [Indexed: 02/05/2023] Open
Abstract
PURPOSE To analyzed the outcome of ETV6/RUNX1-positive pediatric acute B lymphoblastic leukemia (B-ALL) with the aim of identifying prognostic value. METHOD A total of 2,530 pediatric patients who were diagnosed with B-ALL were classified into two groups based on the ETV6/RUNX1 status by using a retrospective cohort study method from February 28, 2008, to June 30, 2020, at 22 participating ALL centers. RESULTS In total, 461 (18.2%) cases were ETV6/RUNX1-positive. The proportion of patients with risk factors (age <1 year or ≥10 years, WB≥50×109/L) in ETV6/RUNX1-positive group was significantly lower than that in negative group (P<0.001), while the proportion of patients with good early response (good response to prednisone, D15 MRD < 0.1%, and D33 MRD < 0.01%) in ETV6/RUNX1-positive group was higher than that in the negative group (P<0.001, 0.788 and 0.004, respectively). Multivariate analysis of 2,530 patients found that age <1 or ≥10 years, SCCLG-ALL-2016 protocol, and MLL were independent predictor of outcome but not ETV6/RUNX1. The EFS and OS of the ETV6/RUNX1-positive group were significantly higher than those of the negative group (3-year EFS: 90.11 ± 4.21% vs 82 ± 2.36%, P<0.0001, 3-year OS: 91.99 ± 3.92% vs 88.79 ± 1.87%, P=0.017). Subgroup analysis showed that chemotherapy protocol, age, prednisone response, and D15 MRD were important factors affecting the prognosis of ETV6/RUNX1-positive children. CONCLUSIONS ETV6/RUNX1-positive pediatric ALL showed an excellent outcome but lack of independent prognostic significance in South China. However, for older patients who have the ETV6/RUNX1 fusion and slow response to therapy, to opt for more intensive treatment.
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Management of cytokine release syndrome after chimeric antigen T-cell therapy for paediatric relapsed/refractory acute lymphoblastic leukaemia: a case report. Hong Kong Med J 2020; 26:532-534. [PMID: 33350967 DOI: 10.12809/hkmj198348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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No pulsed radio emission during a bursting phase of a Galactic magnetar. Nature 2020; 587:63-65. [PMID: 33149293 DOI: 10.1038/s41586-020-2839-y] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 08/31/2020] [Indexed: 11/10/2022]
Abstract
Fast radio bursts (FRBs) are millisecond-duration radio transients of unknown physical origin observed at extragalactic distances1-3. It has long been speculated that magnetars are the engine powering repeating bursts from FRB sources4-13, but no convincing evidence has been collected so far14. Recently, the Galactic magnetar SRG 1935+2154 entered an active phase by emitting intense soft γ-ray bursts15. One FRB-like event with two peaks (FRB 200428) and a luminosity slightly lower than the faintest extragalactic FRBs was detected from the source, in association with a soft γ-ray/hard-X-ray flare18-21. Here we report an eight-hour targeted radio observational campaign comprising four sessions and assisted by multi-wavelength (optical and hard-X-ray) data. During the third session, 29 soft-γ-ray repeater (SGR) bursts were detected in γ-ray energies. Throughout the observing period, we detected no single dispersed pulsed emission coincident with the arrivals of SGR bursts, but unfortunately we were not observing when the FRB was detected. The non-detection places a fluence upper limit that is eight orders of magnitude lower than the fluence of FRB 200428. Our results suggest that FRB-SGR burst associations are rare. FRBs may be highly relativistic and geometrically beamed, or FRB-like events associated with SGR bursts may have narrow spectra and characteristic frequencies outside the observed band. It is also possible that the physical conditions required to achieve coherent radiation in SGR bursts are difficult to satisfy, and that only under extreme conditions could an FRB be associated with an SGR burst.
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Self-perceived disease control in childhood eczema. J DERMATOL TREAT 2020; 33:1459-1464. [PMID: 32962454 DOI: 10.1080/09546634.2020.1826395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND Atopic eczema (AE) is a common relapsing inflammatory skin disease in children which is often associated with chronicity and poor quality of life. Unlike atopic asthma, control of AE is seldom assessed in therapeutics. AIM To investigate the utility of a Traffic Light Control (TLC) system as a measurement/assessment of self-perceived eczema control. METHODS This is a prospectively study of all Chinese children (aged 6 to 18 years old) with eczema attending the paediatric dermatology clinic of a tertiary hospital from Jan to June 2020. Eczema control, eczema severity, quality of life and biophysical skin condition of consecutive patients at the paediatric dermatology clinic of a teaching hospital were evaluated with the validated Chinese versions of Depressive, Anxiety, Stress Scales (DASS-21), Patient Oriented Eczema Measure (POEM), transepidermal water loss (TEWL), and stratum corneum skin hydration (SH), respectively. With a visual TLC analogy, patients were asked if their eczema is under control (green light), worsening (yellow) or in flare-up (red light). RESULTS Among AE patients (n = 36), self-perceived TLC as green (under control), amber (worsening) and red (flare up) reflected acute and chronic severity (SCORAD, NESS, POEM) and quality of life (CDLQI) (p< 0.0001), but not SH, TEWL or Depression, anxiety and stress. CONCLUSIONS Eczema control can be semi-quantified with a child-friendly TLC self-assessment system. AE patients reporting worse eczema control have worse acute and chronic eczema severity, more impairment of quality of life; but not the psychologic symptoms of depression, anxiety and stress or skin hydration or transepidermal water loss. TLC can be linked to an eczema action plan to guide patient management.
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Brain death in children: a retrospective review of patients at a paediatric intensive care unit. Hong Kong Med J 2020; 26:120-126. [PMID: 32285804 DOI: 10.12809/hkmj198126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
PURPOSE Among patients in paediatric intensive care units (PICUs), death is sometimes inevitable despite advances in treatment. Some PICU patients may have irreversible cessation of all brain function, which is considered as brain death (BD). This study investigated demographic and clinical differences between PICU patients with BD and those with cardiopulmonary death. METHODS All children who died in the PICU at a university-affiliated trauma centre between October 2002 and October 2018 were included in this retrospective study. Demographics and clinical characteristics were compared between patients with BD and patients with cardiopulmonary death. RESULTS Of the 2784 patients admitted to the PICU during the study period, 127 died (4.6%). Of these 127 deaths, 22 (17.3%) were BD and 105 were cardiopulmonary death. Length of PICU stay was shorter for patients with cardiopulmonary death than for patients with BD (2 vs 8.5 days, P=0.0042). The most common mechanisms of injury in patients with BD were hypoxic-ischaemic injury (40.9%), central nervous system infection (18.2%), and traumatic brain injury (13.6%). The combined proportion of accident and trauma-related injury was greater in patients with BD than in patients with cardiopulmonary death (27.3% vs 3.8%, P<0.001). Organ donation was approved by the families of four of the 22 patients with BD (18.2%) and was performed successfully in three of these four patients. CONCLUSIONS These findings emphasise the importance of injury prevention in childhood, as well as the need for education of the public regarding acceptance of BD and support for organ donation.
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Collisionless Shocks Driven by Supersonic Plasma Flows with Self-Generated Magnetic Fields. PHYSICAL REVIEW LETTERS 2019; 123:055002. [PMID: 31491329 DOI: 10.1103/physrevlett.123.055002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 06/07/2019] [Indexed: 06/10/2023]
Abstract
Collisionless shocks are ubiquitous in the Universe as a consequence of supersonic plasma flows sweeping through interstellar and intergalactic media. These shocks are the cause of many observed astrophysical phenomena, but details of shock structure and behavior remain controversial because of the lack of ways to study them experimentally. Laboratory experiments reported here, with astrophysically relevant plasma parameters, demonstrate for the first time the formation of a quasiperpendicular magnetized collisionless shock. In the upstream it is fringed by a filamented turbulent region, a rudiment for a secondary Weibel-driven shock. This turbulent structure is found responsible for electron acceleration to energies exceeding the average energy by two orders of magnitude.
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Direct Observations of Particle Dynamics in Magnetized Collisionless Shock Precursors in Laser-Produced Plasmas. PHYSICAL REVIEW LETTERS 2019; 122:245001. [PMID: 31322368 DOI: 10.1103/physrevlett.122.245001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 05/22/2019] [Indexed: 06/10/2023]
Abstract
We present the first laboratory observations of time-resolved electron and ion velocity distributions in magnetized collisionless shock precursors. Thomson scattering of a probe laser beam was used to observe the interaction of a laser-driven, supersonic piston plasma expanding through an ambient plasma in an external magnetic field. From the Thomson-scattered spectra we measure time-resolved profiles of electron density, temperature, and ion flow speed, as well as spatially resolved magnetic fields from proton radiography. We observe direct evidence of the coupling between piston and ambient plasmas, including the acceleration of ambient ions driven by magnetic and pressure gradient electric fields, and deformation of the piston ion flow, key steps in the formation of magnetized collisionless shocks. Even before a shock has fully formed, we observe strong density compressions and electron heating associated with the pileup of piston ions. The results demonstrate that laboratory experiments can probe particle velocity distributions relevant to collisionless shocks, and can complement, and in some cases overcome, the limitations of similar measurements undertaken by spacecraft missions.
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Interpretation of proton radiography experiments of hohlraums with three-dimensional simulations. Phys Rev E 2019; 99:053207. [PMID: 31212418 DOI: 10.1103/physreve.99.053207] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Indexed: 11/07/2022]
Abstract
Proton radiography experiments of laser-irradiated hohlraums performed at the OMEGA laser facility are analyzed using three-dimensional (3D) hydrodynamic simulations coupled to a proton trajectography package. Experiments with three different laser irradiation patterns were performed, and each produced a distinct proton image. By comparing these results with synthetic proton images obtained by sending protons through plasma profiles in the hohlraum obtained from 3D radiation hydrodynamic simulations, it is found that the simulated images agree favorably with the experimental images when electric fields, due to the electron pressure gradients that arise from 3D structures occurring during plasma expansion, are included. These comparisons provide quantitative estimates of the electric field present inside the hohlraums.
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[Clinical analysis of ankle arthroscopy technique for treatment of tarsal tunnel syndrome]. ZHONGHUA YI XUE ZA ZHI 2019; 98:2995-2998. [PMID: 30392255 DOI: 10.3760/cma.j.issn.0376-2491.2018.37.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To explore the effects of ankle arthroscopy technique in treating the tarsal tunnel syndrome. Methods: From May 2014 to May 2016, the ankle arthroscopy technique was used for surgical treatment of tarsal tunnel syndrome in the Department of Hand and Foot Microsurgery in Xuzhou Central Hospital. Twenty-two patients with 24 feet with tarsal tunnel syndrome were hospitalized for treatment, with 10 left feet and 14 right feet, aged 26-57 years. The disease duration ranged from 4 to 15 months (mean 8.3 months). The dual-portals ankle arthroscopic neurolysis and fiber membrane resection were performed. The Pfeiffer scoring system was used to evaluate the post-operative outcomes. Results: Primarily healing of the wound was achieved in all the patients. No postoperative infection was found during the follow-up. The postoperative hospitalization time was 2 to 5 days (mean 3.7 days). All patients were followed up for 12 to 24 months. At the final follow-up, all the patients had significant improvement in numbness and pain. According to the Pfeiffer scoring system, the results were excellent in 16 feet, good in 8 feet, with an excellent and good rate of 100%. Conclusion: The ankle arthroscopic neurolysis is a safe and easy treatment option for the tarsal tunnel syndrome and provides satisfactory results.
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Tripled yield in direct-drive laser fusion through statistical modelling. Nature 2019; 565:581-586. [PMID: 30700868 DOI: 10.1038/s41586-019-0877-0] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 12/04/2018] [Indexed: 11/09/2022]
Abstract
Focusing laser light onto a very small target can produce the conditions for laboratory-scale nuclear fusion of hydrogen isotopes. The lack of accurate predictive models, which are essential for the design of high-performance laser-fusion experiments, is a major obstacle to achieving thermonuclear ignition. Here we report a statistical approach that was used to design and quantitatively predict the results of implosions of solid deuterium-tritium targets carried out with the 30-kilojoule OMEGA laser system, leading to tripling of the fusion yield to its highest value so far for direct-drive laser fusion. When scaled to the laser energies of the National Ignition Facility (1.9 megajoules), these targets are predicted to produce a fusion energy output of about 500 kilojoules-several times larger than the fusion yields currently achieved at that facility. This approach could guide the exploration of the vast parameter space of thermonuclear ignition conditions and enhance our understanding of laser-fusion physics.
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Observations of Multiple Nuclear Reaction Histories and Fuel-Ion Species Dynamics in Shock-Driven Inertial Confinement Fusion Implosions. PHYSICAL REVIEW LETTERS 2019; 122:035001. [PMID: 30735406 DOI: 10.1103/physrevlett.122.035001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/27/2018] [Indexed: 06/09/2023]
Abstract
Fuel-ion species dynamics in hydrodynamiclike shock-driven DT^{3}He-filled inertial confinement fusion implosion is quantitatively assessed for the first time using simultaneously measured D^{3}He and DT reaction histories. These reaction histories are measured with the particle x-ray temporal diagnostic, which captures the relative timing between different nuclear burns with unprecedented precision (∼10 ps). The observed 50±10 ps earlier D^{3}He reaction history timing (relative to DT) cannot be explained by average-ion hydrodynamic simulations and is attributed to fuel-ion species separation between the D, T, and ^{3}He ions during shock convergence and rebound. At the onset of the shock burn, inferred ^{3}He/T fuel ratio in the burn region using the measured reaction histories is much higher as compared to the initial gas-filled ratio. As T and ^{3}He have the same mass but different charge, these results indicate that the charge-to-mass ratio plays an important role in driving fuel-ion species separation during strong shock propagation even for these hydrodynamiclike plasmas.
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Experimental Validation of Low-Z Ion-Stopping Formalisms around the Bragg Peak in High-Energy-Density Plasmas. PHYSICAL REVIEW LETTERS 2019; 122:015002. [PMID: 31012651 DOI: 10.1103/physrevlett.122.015002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Revised: 10/21/2018] [Indexed: 06/09/2023]
Abstract
We report on the first accurate validation of low-Z ion-stopping formalisms in the regime ranging from low-velocity ion stopping-through the Bragg peak-to high-velocity ion stopping in well-characterized high-energy-density plasmas. These measurements were executed at electron temperatures and number densities in the range of 1.4-2.8 keV and 4×10^{23}-8×10^{23} cm^{-3}, respectively. For these conditions, it is experimentally demonstrated that the Brown-Preston-Singleton formalism provides a better description of the ion stopping than other formalisms around the Bragg peak, except for the ion stopping at v_{i}∼0.3v_{th}, where the Brown-Preston-Singleton formalism significantly underpredicts the observation. It is postulated that the inclusion of nuclear-elastic scattering, and possibly coupled modes of the plasma ions, in the modeling of the ion-ion interaction may explain the discrepancy of ∼20% at this velocity, which would have an impact on our understanding of the alpha energy deposition and heating of the fuel ions, and thus reduce the ignition threshold in an ignition experiment.
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[Analysis on long-term trends of cervical cancer mortality and years of life lost in Tianjin, 1999-2015]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 2019; 40:64-69. [PMID: 30669733 DOI: 10.3760/cma.j.issn.0254-6450.2019.01.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To analyze the mortality and years of life lost (YLL) trends of cervical cancer in Tianjin, and provide references for the research and prevention programs of cervical cancer. Methods: Mortality rate, standard mortality rate, cumulative rate (0-74 years-old) and truncated rate (35-64 years-old) of cervical cancer from 1999 to 2015 were calculated. The annual percentage change of the mortality rate and YLL rate were analyzed by using Joinpoint regression analysis, and the trend in different age-groups were analyzed. Results: From 1999 to 2015, 1 741 cases died of cervical cancer in Tianjin, the average crude mortality rate was 2.15/100 000. The average age-standardized rate of (ASR) China and ASR world were 1.47/100 000 and 1.50/100 000 respectively. The average YLL was 3 347.97 person-years. Deaths occurred in those aged 0-34 years, 35-64 years and 65 years and over accounted for 3.10%, 57.84% and 39.06% of the total, respectively. The mortality rate of cervical cancer in urban area was higher than that in rural area, with a ratio of 1.37∶1 between urban area and rural area. The age-specific mortality rate of cervical cancer during 1999-2015 increased with age. Two peaks of mortality rate were observed in those aged 50 years and aged 75 years, during 2014-2015. From 1999 to 2011, the mortality rate of cervical cancer was stable (APC=-0.2%, P=0.80), but there was a rapid increase from 2011 to 2015 (APC=21.6%, P<0.01). But group aged 20-49 years, it showed an upward trend from 1999 to 2015 (APC=6.9%, P<0.01). For group aged 50-69 years, it showed a downward trend from 1999 to 2007 (APC=-9.2%, P<0.01), and an upward trend from 2007 to 2015 (APC=14.5%, P<0.01). For group aged 70 years and over, it showed a downward trend from 1999 to 2009 (APC=-10.2%, P<0.01), but the difference in the mortality were not significant from 2009 to 2015 (APC=7.8%, P=0.10). Since 2008, the YLL rate of cervical cancer in group aged 50-70 years had exceeded that in group aged >70 years and the gap gradually widened. Conclusions: There had been a rapid increase trend of cervical cancer mortality since 2011 in Tianjin. Women aged 50-70 years were the main group of life loss.
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Implementation of the foil-on-hohlraum technique for the magnetic recoil spectrometer for time-resolved neutron measurements at the National Ignition Facility. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:113508. [PMID: 30501287 DOI: 10.1063/1.5052184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 11/02/2018] [Indexed: 06/09/2023]
Abstract
The next-generation Magnetic Recoil Spectrometer, called MRSt, will provide time-resolved measurements of the deuterium-tritium-neutron spectrum from inertial confinement fusion implosions at the National Ignition Facility. These measurements will provide critical information about the time evolution of the fuel assembly, hot-spot formation, and nuclear burn. The absolute neutron spectrum in the energy range of 12-16 MeV will be measured with high accuracy (∼5%), unprecedented energy resolution (∼100 keV) and, for the first time ever, time resolution (∼20 ps). Crucial to the design of the system is a CD conversion foil for the production of recoil deuterons positioned as close to the implosion as possible. The foil-on-hohlraum technique has been demonstrated by placing a 1-mm-diameter, 40-μm-thick CD foil on the hohlraum diagnostic band along the line-of-sight of the current time-integrated MRS system, which measured the recoil deuterons. In addition to providing validation of the foil-on-hohlraum technique for the MRSt design, substantial improvement of the MRS energy resolution has been demonstrated.
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Measurement of apparent ion temperature using the magnetic recoil spectrometer at the OMEGA laser facility. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:10I129. [PMID: 30399924 DOI: 10.1063/1.5035287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 06/05/2018] [Indexed: 06/08/2023]
Abstract
The Magnetic Recoil neutron Spectrometer (MRS) at the OMEGA laser facility has been routinely used to measure deuterium-tritium (DT) yield and areal density in cryogenically layered implosions since 2008. Recently, operation of the OMEGA MRS in higher-resolution mode with a new smaller, thinner (4 cm2, 57 μm thick) CD2 conversion foil has also enabled inference of the apparent DT ion temperature (T ion) from MRS data. MRS-inferred T ion compares well with T ion as measured using neutron time-of-flight spectrometers, which is important as it demonstrates good understanding of the very different systematics associated with the two independent measurements. The MRS resolution in this configuration, ΔE MRS = 0.91 MeV FWHM, is still higher than that required for a high-precision T ion measurement. We show how fielding a smaller foil closer to the target chamber center and redesigning the MRS detector array could bring the resolution to ΔE MRS = 0.45 MeV, reducing the systematic T ion uncertainty by more than a factor of 4.
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Proton Spectra from ^{3}He+T and ^{3}He+^{3}He Fusion at Low Center-of-Mass Energy, with Potential Implications for Solar Fusion Cross Sections. PHYSICAL REVIEW LETTERS 2017; 119:222701. [PMID: 29286782 DOI: 10.1103/physrevlett.119.222701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Indexed: 06/07/2023]
Abstract
Few-body nuclear physics often relies upon phenomenological models, with new efforts at the ab initio theory reported recently; both need high-quality benchmark data, particularly at low center-of-mass energies. We use high-energy-density plasmas to measure the proton spectra from ^{3}He+T and ^{3}He+^{3}He fusion. The data disagree with R-matrix predictions constrained by neutron spectra from T+T fusion. We present a new analysis of the ^{3}He+^{3}He proton spectrum; these benchmarked spectral shapes should be used for interpreting low-resolution data, such as solar fusion cross-section measurements.
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Transition from Collisional to Collisionless Regimes in Interpenetrating Plasma Flows on the National Ignition Facility. PHYSICAL REVIEW LETTERS 2017; 118:185003. [PMID: 28524679 DOI: 10.1103/physrevlett.118.185003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Indexed: 06/07/2023]
Abstract
A study of the transition from collisional to collisionless plasma flows has been carried out at the National Ignition Facility using high Mach number (M>4) counterstreaming plasmas. In these experiments, CD-CD and CD-CH planar foils separated by 6-10 mm are irradiated with laser energies of 250 kJ per foil, generating ∼1000 km/s plasma flows. Varying the foil separation distance scales the ion density and average bulk velocity and, therefore, the ion-ion Coulomb mean free path, at the interaction region at the midplane. The characteristics of the flow interaction have been inferred from the neutrons and protons generated by deuteron-deuteron interactions and by x-ray emission from the hot, interpenetrating, and interacting plasmas. A localized burst of neutrons and bright x-ray emission near the midpoint of the counterstreaming flows was observed, suggesting strong heating and the initial stages of shock formation. As the separation of the CD-CH foils increases we observe enhanced neutron production compared to particle-in-cell simulations that include Coulomb collisions, but do not include collective collisionless plasma instabilities. The observed plasma heating and enhanced neutron production is consistent with the initial stages of collisionless shock formation, mediated by the Weibel filamentation instability.
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A broadband proton backlighting platform to probe shock propagation in low-density systems. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:013503. [PMID: 28147638 DOI: 10.1063/1.4973893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A proton backlighting platform has been developed for the study of strong shock propagation in low-density systems in planar geometry. Electric fields at the converging shock front in inertial confinement fusion implosions have been previously observed, demonstrating the presence of-and the need to understand-strong electric fields not modeled in standard radiation-hydrodynamic simulations. In this planar configuration, long-pulse ultraviolet lasers are used to drive a strong shock into a gas-cell target, while a short-pulse proton backlighter side-on radiographs the shock propagation. The capabilities of the platform are presented here. Future experiments will vary shock strength and gas fill, to probe shock conditions at different Z and Te.
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