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Improved fission neutron energy discrimination with <sup>4</sup>He detectors through pulse filtering
Zhu, Ting,Liang, Yinong,Rolison, Lucas,Barker, Cathleen,Lewis, Jason,Gokhale, Sasmit,Chandra, Rico,Kiff, Scott,Chung, Heejun,Ray, Heather,Baciak, James E.,Enqvist, Andreas,Jordan, Kelly A. Elsevier 2017 Nuclear Instruments & Methods in Physics Research. Vol.848 No.-
<P><B>Abstract</B></P> <P>This paper presents experimental and computational techniques implemented for <SUP>4</SUP>He gas scintillation detectors for induced fission neutron detection. Fission neutrons are produced when natural uranium samples are actively interrogated by 2.45MeV deuterium-deuterium fusion reaction neutrons. Fission neutrons of energies greater than 2.45MeV can be distinguished by their different scintillation pulse height spectra since <SUP>4</SUP>He detectors retain incident fast neutron energy information. To enable the preferential detection of fast neutrons up to 10MeV and suppress low-energy event counts, the detector photomultiplier gain is lowered and trigger threshold is increased. Pile-up and other unreliable events due to the interrogating neutron flux and background radiation are filtered out prior to the evaluation of pulse height spectra. With these problem-specific calibrations and data processing, the <SUP>4</SUP>He detector's accuracy at discriminating fission neutrons up to 10MeV is improved and verified with <SUP>252</SUP>Cf spontaneous fission neutrons. Given the <SUP>4</SUP>He detector's ability to differentiate fast neutron sources, this proof-of-concept active-interrogation measurement demonstrates the potential of special nuclear materials detection using a <SUP>4</SUP>He fast neutron detection system.</P>
Endoscopic Anterior Lumbar Interbody Fusion: Systematic Review and Meta-Analysis
Brown Nolan J.,Pennington Zach,Kuo Cathleen C.,Lopez Alexander M.,Picton Bryce,Solomon Sean,Nguyen Oanh T.,Yang Chenyi,Tantry Evelyne K.,Shahin Hania,Gendreau Julian,Albano Stephen,Pham Martin H.,Oh M 대한척추외과학회 2023 Asian Spine Journal Vol.17 No.6
Laparoscopic anterior lumbar interbody fusion (L-ALIF), which employs laparoscopic cameras to facilitate a less invasive approach, originally gained traction during the 1990s but has subsequently fallen out of favor. As the envelope for endoscopic approaches continues to be pushed, a recurrence of interest in laparoscopic and/or endoscopic anterior approaches seems possible. Therefore, evaluating the current evidence base in regard to this approach is of much clinical relevance. To this end, a systematic literature search was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using the following keywords: “(laparoscopic OR endoscopic) AND (anterior AND lumbar).” Out of the 441 articles retrieved, 22 were selected for quantitative analysis. The primary outcome of interest was the radiographic fusion rate. The secondary outcome was the incidence of perioperative complications. Meta-analysis was performed using RStudio’s “metafor” package. Of the 1,079 included patients (mean age, 41.8±2.9 years), 481 were males (44.6%). The most common indication for L-ALIF surgery was degenerative disk disease (reported by 18 studies, 81.8%). The mean follow-up duration was 18.8±11.2 months (range, 6–43 months). The pooled fusion rate was 78.9% (95% confidence interval [CI], 68.9–90.4). Complications occurred in 19.2% (95% CI, 13.4–27.4) of L-ALIF cases. Additionally, 7.2% (95% CI, 4.6–11.4) of patients required conversion from L-ALIF to open surgery. Although L-ALIF does not appear to be supported by studies available in the literature, it is important to consider the context from which these results have been obtained. Even if these results are taken at face value, the failure of endoscopy to have a role in the ALIF approach does not mean that it should not be incorporated in posterior approaches.
Pappas, Christopher T.,Mayfield, Rachel M.,Henderson, Christine,Jamilpour, Nima,Cover, Cathleen,Hernandez, Zachary,Hutchinson, Kirk R.,Chu, Miensheng,Nam, Ki-Hwan,Valdez, Jose M.,Wong, Pak Kin,Granzie Proceedings of the National Academy of Sciences 2015 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.112 No.44