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2021 ◽  
pp. 1-9
Author(s):  
Marie Luby ◽  
José G. Merino ◽  
Rachel Davis ◽  
Saeed Ansari ◽  
Marc Fisher ◽  
...  

<b><i>Introduction:</i></b> Despite complete recanalization by mechanical thrombectomy, abnormal perfusion can be detected on MRI obtained post-endovascular therapy (EVT). The presence of residual perfusion abnormalities post-EVT may be associated with blood-brain barrier breakdown in response to mechanical disruption of the endothelium from multiple-pass thrombectomy. We hypothesize that multiple-pass versus single-pass thrombectomy is associated with a higher rate of residual hypoperfusion and increased lesion growth at 24 h. <b><i>Materials and Methods:</i></b> For this analysis, we included patients presenting to one of two stroke centers between January 2015 and February 2018 with an acute ischemic stroke within 12 h from symptom onset if they had a large vessel occlusion of the anterior circulation documented on magnetic resonance angiography or CTA, baseline MRI pre-EVT with imaging evidence of hypoperfusion, underwent EVT, and had a post-EVT MRI with qualitatively interpretable perfusion-weighted imaging data at 24 h. MRI <i>T</i><sub>max</sub> maps using a time delay threshold of &#x3e;6 s were used to quantitate hypoperfusion volumes. Residual hypoperfusion at 24 h was solely defined as <i>T</i><sub>max</sub> volume &#x3e;10 mL with &#x3e;6 s delay. Complete recanalization was defined as modified treatment in cerebral infarction visualized on angiography at EVT completion. Hyperintense acute reperfusion injury marker was assessed on post-EVT pre-contrast fluid-attenuated inversion recovery at 24 h. Major early neurological improvement was defined as a reduction of the admission National Institutes of Health Stroke Scale by ≥8 points or a score of 0–1 at 24 h. Good functional outcome was defined as 0–2 on the modified Rankin Scale on day 30 or 90. <b><i>Results:</i></b> Fifty-five patients were included with median age 67 years, 58% female, 45% Black/African American, 36% White/Caucasian, median admission National Institutes of Health Stroke Scale 19, large vessel occlusion locations: 71% M1, 14.5% iICA, 14.5% M2, 69% treated with intravenous recombinant tissue plasminogen activator. Of these, 58% had multiple-pass thrombectomy, 39% had residual perfusion abnormalities at 24 h, and 64% had severe hyperintense acute reperfusion injury marker at 24 h. After adjusting for complete recanalization, only multiple-pass thrombectomy (odds ratio, 4.3 95% CI, 1.07–17.2; <i>p</i> = 0.04) was an independent predictor of residual hypoperfusion at 24 h. Patients with residual hypoperfusion had larger lesion growth on diffusion-weighted imaging (59 mL vs. 8 mL, <i>p</i> &#x3c; 0.001), lower rate of major early neurological improvement (24% vs. 70%, <i>p</i> = 0.002) at 24 h, and worse long-term outcome based on the modified Rankin Scale at 30 or 90 days, 5 versus 2 (<i>p</i> &#x3c; 0.001). <b><i>Conclusions:</i></b> Our findings suggest that incomplete reperfusion on post-EVT MRI is present even in some patients with successful recanalization at the time of EVT and is associated with multiple-pass thrombectomy, lesion growth, and worse outcome. Future studies are needed to investigate whether patients with residual hypoperfusion may benefit from immediate adjunctive therapy to limit lesion growth and improve clinical outcome.


Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1506
Author(s):  
Yu Chen ◽  
Zhihui Cai ◽  
Hua Ding ◽  
Fenghe Zhang

AA6061 and AA7075 aluminum alloys were successfully joined by using single-pass and multiple-pass friction stir welding techniques after which the effects on the nugget zone evolution from a second overlapping pass and its welding direction, were investigated. In comparison to single-pass friction stir welding, the application of a second overlapping pass prolonged the dynamic recrystallization time, and the grains of the nugget zone became finer with increased high angle grain boundaries. Moreover, reversing the welding direction of the second overlapping pass enhanced the vertical flow of materials, increasing the strain of the friction stir welding in the nugget zone. As a result, the efficiency of the grain refinement and mixture of dissimilar materials during the second overlapping pass were significantly elevated. The tensile strength of the nugget zone was improved after the second overlapping pass due to both the grain refinement and mechanical interlocking of the AA6061/AA7075 alloys. The nugget zone, which was fabricated via the multiple-pass friction stir welding technique using an opposite welding direction, exhibited a 23% increase in yield strength as compared to the sample using the single-pass friction stir welding technique.


Vox Sanguinis ◽  
2021 ◽  
Author(s):  
Nadine Schossee ◽  
Gabriele Veit ◽  
Julia Gittel ◽  
Johannes Viebahn ◽  
Marius Niklaus ◽  
...  
Keyword(s):  

2021 ◽  
Vol 295 ◽  
pp. 117149 ◽  
Author(s):  
Hao Nan Li ◽  
Yong Jie Zhao ◽  
Shiyu Cao ◽  
Hao Chen ◽  
Chaoqun Wu ◽  
...  

2021 ◽  
Vol 8 ◽  
Author(s):  
Ismael A. Contreras-Guillén ◽  
Sara Leeson ◽  
Rocio V. Gili ◽  
Belén Carlino ◽  
Daniel Xutuc ◽  
...  

Background: Latin American countries show a fast-growing rate of non-communicable diseases (NCDs) and diet is a critical risk factor that must be properly assessed. Automated dietary assessment tools to collect 24-h dietary recalls (24HR) are lacking in Argentina.Objective: This study aimed to develop an open-access automated tool (MAR24) for collecting 24HR using a multiple pass method and a database containing foods and recipes commonly consumed in Argentina.Methods: MAR24 was developed based on data from 1,285 24HR provided by male and female participants aged 18 to 68 years from the six Argentinian geographical regions. The main structure and interface of the tool were designed using Visual Basic for Applications programming language in Excel Microsoft Office 365, integrating the five steps of the United States Department of Agriculture (USDA) Automated Multiple-Pass Method (AMPM) for the application of 24HR in Spanish. The tool underwent alpha testing and expert assessment to address structural and usability issues. Critical feedback and face validation from researchers and experienced dietitians, and repeated testing to collect 24HR were used to adjust and improve the tool.Results: A total of 968 food items and 100 standard Argentinian recipes were added to its database. MAR24 allows the estimation of the nutrient profile of dietary intake. The analytic food composition includes energy and 50 nutrients including water, macronutrients, total dietary fiber, total sugar, 10 minerals, 19 vitamins, eight fatty acids, cholesterol, ethyl alcohol, caffeine, and theobromine. MAR24 includes a user manual and technical manual to guide users to apply changes (e.g., add foods or recipes, or change food designation according to local terms) to fit different research and clinical applications.Conclusions: MAR24 is the first tool that uses the AMPM methodology for 24HR applications in Argentina. The tool may be used in clinical practice and clinical trials for monitoring purposes, and in validation of food frequency questionnaires (FFQ) for nutritional epidemiology studies addressing dietary-associated risk factors for NCDs.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 847
Author(s):  
Yu-Lun Chuang ◽  
Chu-Chun Wang ◽  
Tai-Cheng Chen ◽  
Ren-Kae Shiue ◽  
Leu-Wen Tsay

9CrMoW steel tubes were welded in multiple passes by gas-tungsten arc welding. The reheated microstructures in the Gr. 92 weld metal (WM) of a multiple-pass weld were simulated with an infrared heating system. Simulated specimens after tempering at 760 °C/2 h were subjected to constant load creep tests either at 630 °C/120 MPa or 660 °C/80 MPa. The simulated specimens were designated as the over-tempered (OT, below AC1, i.e., WT-820T) and partially transformed (PT, below AC3, i.e., WT-890T) samples. The transmission electron microscope (TEM) micrographs demonstrated that the tempered WM (WT) displayed coarse martensite packets with carbides along the lath and grain boundaries. Cellular subgrains and coarse carbides were observed in the WT-820T sample. A degraded lath morphology and numerous carbides in various dimensions were found in the WT-890T sample. The grain boundary map showed that the WT-820T sample had the same coarse-grained structure as the WT sample, but the WT-890T sample consisted of refined grains. The WT-890T samples with a fine-grained structure were more prone to creep fracture than the WT and WT-820T samples were. Intergranular cracking was more likely to occur at the corners of the crept samples, which suffered from high strain and stress concentration. As compared to the Gr. 91 steel or Gr. 91 WM, the Gr. 92 WM was more stable in maintaining its original microstructures under the same creep condition. Undegraded microstructures of the Gr. 92 WM strained at elevated temperatures were responsible for its higher resistance to creep failure during the practical service.


Author(s):  
Laura DiGrande ◽  
Sue Pedrazzani ◽  
Elizabeth Kinyara ◽  
Melanie Hymes ◽  
Shawn Karns ◽  
...  

Objective: The purpose of this study was to assess the feasibility of administering the Automated Multiple-Pass Method (AMPM), a widely used tool for collecting 24-hour dietary recalls, in participants’ homes by field interviewers. Design: The design included computer-assisted personal interviews led by either a nutritionist (standard) or field interviewer. Portion estimators tested were a set of three-dimensional food models (standard), a two-dimensional food model booklet, or a tablet with digital images rendered via augmented reality. Setting: Residences in central North Carolina. Participants: English-speaking adults. Pregnant women and individuals who were fasting were excluded. Results: Among 133 interviews, most took place in living rooms (52%) or kitchens (22%). Mean interview time was 40 minutes (range 13–90), with no difference by interviewer type or portion estimator, although timing for nutritionist-led interviews declined significantly over the study period. Forty-five percent of participants referenced items from their homes to facilitate recall and portion estimation. Data entry and post-interview coding was evaluated and determined to be consistent with requirements for the National Health and Nutrition Examination Survey. Values for the number of food items consumed, food groups, energy intake (average of 3,011 kcal for men and 2,105 kcal for women), and key nutrients were determined to be plausible and within reasonably expected ranges regardless of interviewer type or portion estimator used. Conclusions: AMPM dietary recall interviews conducted in the home are feasible and may be preferable to clinical administration because of comfort and the opportunity for participants to access home items for recall. AMPMs administered by field interviewers using the food model booklet produced credible nutrition data that was comparable to AMPMs administered by nutritionists. Training field interviewers in dietary recall and conducting home interviews may be sensible choices for nutrition studies when response rates and cost are concerns.


Author(s):  
Steven M. Martinaitis ◽  
Stephen B. Cocks ◽  
Micheal J. Simpson ◽  
Andrew P. Osborne ◽  
Sebastian S. Harkema ◽  
...  

AbstractThis study describes recent advancements in the Multi-Radar Multi-Sensor (MRMS) automated gauge ingest and quality control (QC) processes. A data latency analysis for the combined multiple gauge collection platforms provided guidance for a multiple-pass generation and delivery of gauge-based precipitation products. Various advancements to the gauge QC logic were evaluated over a 21-month period, resulting in an average of 86% of hourly gauge observations per hour being classified as useful. The fully-automated QC logic was compared to manual human QC for a limited domain, which showed a > 95% agreement in their QC reasoning categories. This study also includes an extensive evaluation of various characteristics related to the gauge observations ingested into the MRMS system. Duplicate observations between gauge collection platforms highlighted differences in site coordinates; moreover, errors in Automated Surface Observing System (ASOS) station site coordinates resulted in > 79% of sites being located in a different MRMS 1-km grid cell. The ASOS coordinate analysis combined with examinations of other limitations regarding gauge observations highlight the need for robust and accurate metadata to further enhance the quality control of gauge data.


2021 ◽  
pp. 1-6
Author(s):  
Christopher Blair ◽  
Leon Edwards ◽  
Cecilia Cappelen-Smith ◽  
Dennis Cordato ◽  
Andrew Cheung ◽  
...  

<b><i>Background and Purpose:</i></b> The benefit of bridging intravenous thrombolysis (IVT) in acute ischaemic stroke patients eligible for endovascular thrombectomy (EVT) is unclear. This may be particularly relevant where reperfusion is achieved with multiple thrombectomy passes. We aimed to determine the benefit of bridging IVT in first and multiple-pass patients undergoing EVT ≤6 h from stroke onset to groin puncture. <b><i>Methods:</i></b> We compared 90-day modified Rankin Scale (mRS) outcomes in 187 consecutive patients with large vessel occlusions (LVOs) of the anterior cerebral circulation who underwent EVT ≤6 h from symptom onset and who achieved modified thrombolysis in cerebral ischaemia (mTICI) 2c/3 reperfusion with the first pass to those patients who required multiple passes to achieve reperfusion. The effect of bridging IVT on outcomes was examined. <b><i>Results:</i></b> Significantly more first-pass patients had favourable (mRS 0–2) 90-day outcomes (68 vs. 42%, <i>p</i> = 0.001). Multivariate analysis showed an association between first-pass reperfusion and favourable outcomes (OR 2.25; 95% CI 1.08–4.68; <i>p</i> = 0.03). IVT provided no additional benefit in first-pass patients (OR 1.17; CI 0.42–3.20; <i>p</i> = 0.76); however, in multiple-pass patients, it reduced the risk of disabling stroke (mRS ≥4) (OR 0.30; CI 0.10–0.88; <i>p</i> = 0.02) and mortality (OR 0.07; CI 0.01–0.36; <i>p</i> = 0.002) at 90 days. <b><i>Conclusion:</i></b> Bridging IVT may benefit patients with anterior circulation stroke with LVO who qualify for EVT and who require multiple passes to achieve reperfusion.


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