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A bilateral comparison was conducted between the International Atomic Energy Agency (IAEA) and the Korea Research Institute of Standards and Science (KRISS) to measure the absorbed dose to water in accelerator photon beams. KRISS served as a linking laboratory to compare the IAEA standard with the key comparison reference value (KCRV) of the BIPM.RI(I)–K6 program, in which KRISS participated in 2017.Two ionization chambers from the IAEA were used as transfer instruments for the comparison. Both laboratories measured the calibration coefficients of these instruments and calculated the ratios. The ratio of the KRISS standard to the KCRV was applied to obtain the degree of equivalence of the IAEA, along with its uncertainty. The largest deviation of the IAEA measurement from the KCRV was 3.4 mGy/Gy, significantly smaller than the expanded uncertainty of 10.7 mGy/Gy (k = 2, 95% level of confidence).This study demonstrates the equivalence of IAEA's measurement standard for accelerator photon beams to other primary standard dosimetry laboratories. It provides evidence for the satisfactory operation of IAEA's quality management system and enhances the international credibility of the IAEA SSDL network, particularly in high-energy accelerator photon beams from linear accelerators.

BackgroundPrehospital automated large vessel occlusion (LVO) detection in Mobile Stroke Units (MSUs) could accelerate identification and treatment of patients with LVO acute ischemic stroke. Here, we evaluate the performance of a machine learning (ML) model on CT angiograms (CTAs) obtained from 2 MSUs to detect LVO.MethodsPatients evaluated on MSUs in Houston and Los Angeles with out-of-hospital CTAs were identified. Anterior circulation LVO was defined as an occlusion of the intracranial internal carotid artery, middle cerebral artery (M1 or M2), or anterior cerebral artery vessels and determined by an expert human reader. A ML model to detect LVO was trained and tested on independent data sets consisting of in-hospital CTAs and then tested on MSU CTA images. Model performance was determined using area under the receiver-operator curve statistics.ResultsAmong 68 patients with out-of-hospital MSU CTAs, 40% had an LVO. The most common occlusion location was the middle cerebral artery M1 segment (59%), followed by the internal carotid artery (30%), and middle cerebral artery M2 (11%). Median time from last known well to CTA imaging was 88.0 (interquartile range, 59.5-196.0) minutes. After training on 870 in-hospital CTAs, the ML model performed well in identifying LVO in a separate in-hospital data set of 441 images with area under receiver-operator curve of 0.84 (95% CI, 0.80-0.87). ML algorithm analysis time was under 1 minute. The performance of the ML model on the MSU CTA images was comparable with area under receiver-operator curve 0.80 (95% CI, 0.71-0.89). There was no significant difference in performance between the Houston and Los Angeles MSU CTA cohorts.ConclusionsIn this study of patients evaluated on MSUs in 2 cities, a ML algorithm was able to accurately and rapidly detect LVO using prehospital CTA acquisitions.

Abstract Most of the dams registered on the National Information System on Dam Safety (SNISB of Brazil) do not have enough information to assess whether they fit into the National Dam Safety Policy (PNSB), or to assess their safety conditions. According to the National Agency of Waters (ANA, 2021b), there are currently 122 dams with some important structural problems indicated by their inspectors in 23 states. Therefore, this article proposes a methodology for identifying faults in dam safety activities. The method applies to all types of existing dams. The proposed methodology comprises ten stages that, according to the progress of the steps, are defined by three levels of completeness of the information. Tables were developed with the objective of being a verification guide for these ten stages. This research applied the proposed methodology to two dams in Paraná, Brazil. The first is the Iraí dam, located in the metropolitan region of Curitiba, and the second is the Jordan River Derivation dam, located in Reserva do Iguaçu. The example of the Iraí dam could complete all stages of the proposed methodology. For the Jordan River Derivation dam, stages 1 to 5 of the proposed methodology were carried out. The application of the proposed methodology intends to become a useful tool, especially for inspectors, aiming at a more effective registration process, accelerating the completion of the SNISB.

Background The impact of mobile stroke units (MSUs) on outcomes in patients with large vessel occlusions eligible for endovascular thrombectomy (EVT) has yet to be characterized. Methods We completed a prespecified substudy of patients with EVT‐eligible stroke with anterior and posterior circulation large vessel occlusions on computed tomography and/or computed tomography angiography who were enrolled in BEST‐MSU (Benefits of Stroke Treatment using a Mobile Stroke Unit). Primary outcome was 90‐day utility‐weighted modified Rankin scale. Groups were compared using chi‐square or Fisher's exact tests for categorical variables, and 2‐sample t‐tests for continuous variables. Multiple logistic regression was used to assess the effect of MSU on binary outcomes after adjusting for other baseline factors. Results Of 1515 trial patients, 293 had large vessel occlusions eligible for EVT: 168 in the MSU group and 125 in the emergency medical services group. Baseline characteristics were comparable, with the exception of baseline National Institutes of Health Stroke Scale score (MSU median 19 [interquartile range 13, 23] versus emergency medical services 16 [11, 20], P = 0.002) and study site. The mean (±SD) score on the utility‐weighted modified Rankin scale at 90 days was 0.63±0.39 in MSU group and 0.51±0.41 in emergency medical services group (mean difference 0.13, 95% CI [0.03–0.22]). After adjustment, MSU had significantly higher odds of functional independence (odds ratio 2.60 [95% CI, 1.45–4.77], P = 0.002). Secondary outcomes also favored MSU: early neurologic recovery (30% improvement in National Institutes of Health Stroke Scale score at 24 hours) 68% versus 52%; adjusted odds ratio 1.98 [95% CI, 1.19–3.33]; time of tissue plasminogen activator bolus from symptom onset 65.0 minutes [50.5–92.0] versus 96.0 [79.3–130.0], P≤0.001. The groups had similar onset to arterial puncture (169.0 minutes [133.5, 210.0] versus 162.0 [135.0–207.0], P = 0.83). Conclusions In patients with EVT‐eligible large vessel occlusion stroke, MSU management was associated with better clinical outcomes compared with standard emergency medical services management. MSU management sped thrombolysis but did not expedite EVT treatment times. Future MSU processes should include efforts to capitalize on the potential of MSUs to provide earlier EVT.

Abstract Background Intracerebral hemorrhage (ICH) is a devastating disease that carries a 30 day mortality of approximately 45%. Only 20% of survivors return to independent function at 6 months. The role of inflammation in the pathophysiology of ICH is increasingly recognized. Several clinical studies have demonstrated an association between inflammatory markers and outcomes after ICH; however the relationship between serum biomarkers and functional outcomes amongst survivors has not been previously evaluated. Activation of the inflammatory response as measured by change in peripheral leukocyte count was examined and assessment of mortality and functional outcomes after ICH was determined. Findings Patients with spontaneous ICH admitted to a tertiary care center between January 2005 and April 2010 were included. The change in leukocyte count was measured as the difference between the maximum leukocyte count in the first 72 hours and the leukocyte count on admission. Mortality was the primary outcome. Secondary outcomes were mortality at 1 year, discharge disposition and the modified Barthel index (MBI) at 3 months compared to pre-admission MBI. 423 cases were included. The in-hospital mortality was 30.4%. The change in leukocyte count predicted worse discharge disposition (OR = 1.258, p = 0.009). The change in leukocyte count was also significantly correlated with a decline in the MBI at 3 months. These relationships remained even after removal of all patients with evidence of infection. Conclusions Greater changes in leukocyte count over the first 72 hours after admission predicted both worse short term and long term functional outcomes after ICH.

In Brazil, there is a shortage of approximately 5.80 million residences, a challenge that intensified during the pandemic. Since 2013, there has been a mandate to implement specific performance criteria in residential constructions. However, many construction firms face difficulties in meeting these standards, especially concerning sound insulation in partition elements. This work aims to assess the airborne sound insulation performance and compliance with legal standards in new residential buildings through measurements and simulations. In particular, subsidized housing units for low-income populations are studied, which are eligible for reduced taxes on building loans. These buildings are typically made of hollow ceramic blocks with vertical perforations as separating walls, a commonly used national building material. Three buildings located in Guarapuava, a southern city in Brazil with a population of approximately 183,000 residents, were selected for this purpose. Measurements were conducted following ISO 16283-1 guidelines, whereas simulations were performed using ISO 12354-1, initially assuming a uniform plate but also exploring an alternative model that considers orthotropic behavior with analytical expressions. The calculations considered both static and dynamic moduli of elasticity. The results indicated that all the units failed to meet the specified standards. The measured DnT,w values were below the required thresholds, obtaining 42 < 45 dB for Building B1, 40 < 45 dB for Building B2, and 38 < 40 dB for Building B3. The predicted DnT,w values agreed well with the measured values when considering orthotropy with a dynamic elastic modulus. However, discrepancies were observed in the spectral analysis, especially at lower and higher frequencies. The findings suggest refraining from employing single-leaf partition walls made of vertical hollow ceramic blocks in such buildings. Improving sound insulation necessitates embracing a comprehensive strategy that takes into account the separating element, flanking paths, and the room geometries.

Background Clinical and radiographic outcomes after mechanical thrombectomy in the setting of COVID‐19 infection remain poorly characterized. We sought to determine how COVID‐19 status affects mechanical thrombectomy outcomes in the real‐world setting in the United States. Methods The prospectively maintained multicenter mechanical thrombectomy registry from the Society of Vascular and Interventional Neurology was queried for baseline clinical characteristics among patients with and without COVID‐19 who underwent mechanical thrombectomy between March 1 and December 31, 2020 at 12 sites. Primary outcome was the likelihood of good neurological outcomes (90 day modified Rankin scale 0–2) among patients with COVID‐19 treated with endovascular thrombectomy, which was assessed using multivariable logistic regression adjusted for age, National Institutes of Health Stroke Scale, Alberta Stroke Program Early CT Score, and substantial reperfusion (modified Thrombolysis in Cerebral Infarction 2b, 2c, and 3). Secondary outcomes included National Institutes of Health Stroke Scale at 24 hours. Results Among 915 patients who underwent mechanical thrombectomy during the study period, 51 patients were positive for COVID‐19 (5.6%). Univariate analysis revealed that compared with patients who were COVID‐19 negative, patients who were positive for COVID‐19 were more likely to be male, nonsmokers, have lower Alberta Stroke Program Early CT Score, and present with intracranial internal carotid artery occlusions (Table 1). They were also less likely to achieve successful reperfusion. Multivariable analysis, however, failed to identify any independent associations with COVID‐19 positive status. Conclusion In our cohort, patients postive for COVID‐19 with acute ischemic stroke who undergo mechanical thrombectomy have similar baseline characteristics, imaging features, procedural, and clinical outcomes compared to patients who are negative for COVID‐19 in multivariate analysis. Further analyses are warranted.

Introduction Mobile Stroke Units (MSUs) speed treatment with tPA, but did not affect time from alert to puncture time for endovascular therapy (EVT) in the Benefits of Stroke Treatment Using a Mobile Stroke Unit (BEST‐MSU), a prospective multicenter controlled trial comparing MSU with standard EMS management. The lack of improvement in EVT treatment time could be because the CTA to identify large vessel occlusions (LVOs), and alerting of the EVT team, were delayed in most MSU patients until after Emergency Department (ED) arrival. The impact of identifying LVOs by imaging on the MSU enabling a direct (from MSU) to angiosuite (DTAS) protocol has yet to be studied. Methods We conducted a pre‐specified substudy of tPA‐eligible stroke patients with LVOs on computed tomography (CT) and/or CT angiography (CTA) who were enrolled into the MSU arm of the BEST‐MSU study. We compared alert to puncture time and other process metrics, mean utility‐weighted modified Rankin Scale (uw‐mRS) and functional independence (mRS 0–2) at 90 days, and rate of early neurologic recovery (30% improvement in NIHSS score) at 24 hours in patients who were managed by DTAS vs post‐ED arrival diagnosis and alerting. Results A total of 169 MSU patients with LVOs were identified; 22 in the DTAS group and 111 in the non DTAS group. Data were not available for 36 LVO patients. Baseline characteristics including age, sex, ethnicity, prestroke mRS, and initial NIHSS were comparable between the groups. 100.0% of patients in the DTAS group vs 90.1% in the non DTAS received tPA (p = 0.264). EVT was performed on 85.0% of patients in the DTAS group vs 77.1% in the non DTAS group (p = 0.634). DTAS group had a faster alert to puncture time (108.00 min [94.75,124.75.] vs 150.50 min [121.25, 179.00], p< 0.001) and door to puncture time (37.00 min [25.50,62.75 vs 86.50 min [62.50,116.00], p< 0.001). The mean score on the uw‐mRS at 90 days was 0.626 ±0.367 in the DTAS group and 0.660 ±0.382 in the non DTAS group and after adjustment for age, baseline NIHSS, premorbid functional status, prior stroke/TIA and site, no significant difference was observed; (p = 0.54). In an unadjusted analysis, early neurologic recovery (72.7% vs 67.6%, (OR = 0.634, 95% CI [0.46,3.82]) and functional independence (50.0% vs 51.4%, p = 1.000) were comparable between DTAS and non DTAS patients. Patients in the DTAS group were less likely to receive general anesthesia (36.4% vs 71.2%, p = 0.004). Rates of recanalization (77.3% vs73,4%, p = 0.947) and post procedural PH‐2 hemorrhage (4.5% vs 0.9%, p = 0.746) were similar in the DTAS and non DTAS group respectively. Conclusions In tPA‐eligible LVO stroke patients, DTAS management resulted in shorter alert to puncture (42 minutes) and door to puncture times (50 minutes) with similar safety and clinical outcomes compared with non DTAS management. MSU DTAS represents an optimized pathway for LVO patients triaged and treated in the field.

Introduction The recently published CHOICE trial found that intra‐arterial infusion of alteplase improved clinical outcomes in patients undergoing EVT for LVO AIS, an effect that was possibly due to a reduction in reperfusion‐related injury. Here, we examine whether intravenous alteplase, administered after successful endovascular reperfusion, results in improved clinical outcomes. Methods From our prospectively collected multicenter institutional registry drawn from four comprehensive stroke centers in the greater Houston area, we identified cases who underwent EVT with substantial reperfusion (TICI 2b/3) prior to termination of the intravenous alteplase continuous drip. Control patients were then identified as patients who underwent EVT with TICI 2b/3 after completion of intravenous alteplase, matching on age, baseline Modified Rankin Scale (mRS), initial NIH Stroke Scale (NIHSS), and comorbidities. The primary outcome was 90 day disability and was determined by mRS shift analysis, comparing the case and control populations. Results Among 21 cases and 24 matched controls, there were no significant difference between the mean age, gender, race, initial NIHSS, baseline mRS, or ASPECT score. Time from last known well to recanalization was longer in controls (48 min vs 151 min, p< 0.01). Patients who achieved reperfusion prior to termination of the alteplase continuous drip had better 90 day clinical outcomes relative to their presentation mRS when compared to patients who achieved reperfusion after termination of the alteplase. A change in mRS of 1 or less was seen in 71% vs 33% in the continued infusion group vs controls respectively. Conclusions Patients undergoing EVT who continued to be treated with intravenous alteplase following reperfusion had better 90d clinical outcomes relative to those with reperfusion after infusion termination. These findings further support the possible efficacy of thrombolytics following endovascular reperfusion.

Background The COVID‐19 pandemic has disproportionately affected Black and Hispanic communities, whose stroke care has been previously shown to experience existing disparities. We sought to evaluate how these disparities in stroke care and in‐hospital mortality have been affected by the COVID‐19 pandemic. Methods In this retrospective observational cohort study, we evaluated stroke hospitalizations in the Society of Vascular and Interventional Neurology COVID‐19 registry. We compared stroke characteristics between non‐Hispanic White, non‐Hispanic Black, and Hispanic patients pre–COVID‐19 and post–COVID‐19 (March–July 2019 versus March–July 2020) and evaluated whether racial and ethnic differences present before the pandemic were exacerbated during the pandemic. Our primary outcome was in‐hospital mortality/discharge to hospice, and secondary outcomes were acute treatment use. Results Of the 4908 included patients, numerically fewer non‐Hispanic White and Hispanic patients were evaluated during COVID‐19. Non‐Hispanic White and non‐Hispanic Black patients with large‐vessel occlusion were more likely to undergo thrombectomy (P

Let G be a connected plane graph with vertex set V and edge set E. For X ∈ {V, E, V ∪ E}, two elements of X are facially adjacent in G if they are incident elements, adjacent vertices, or facially adjacent edges (edges that are consecutive on the boundary walk of a face of G). A coloring of G is facial with respect to X if there is a coloring of elements of X such that facially adjacent elements of X receive different colors. A facial coloring of G is odd if for every face f and every color c, either no element or an odd number of elements incident with f is colored by c. In this paper we investigate odd facial colorings of trees. The main results of this paper are the following: (i) Every tree admits an odd facial vertex-coloring with at most 4 colors; (ii) Only one tree needs 6 colors, the other trees admit an odd facial edge-coloring with at most 5 colors; and (iii) Every tree admits an odd facial total-coloring with at most 5 colors. Moreover, all these bounds are tight.

Let G be a plane graph. A facial path of G is a subpath of the boundary walk of a face of G. We prove that each plane graph admits a 3-coloring (a 2-coloring) such that every monochromatic facial path has at most 3 vertices (at most 4 vertices). These results are in a contrast with the results of Chartrand, Geller, Hedetniemi (1968) and Axenovich, Ueckerdt, Weiner (2017) which state that for any positive integer t there exists a 4-colorable (a 3-colorable) plane graph Gt such that in any its 3-coloring (2-coloring) there is a monochromatic path of length at least t. We also prove that every plane graph is 2-list-colorable in such a way that every monochromatic facial path has at most 4 vertices.

Background Compared with non‐Hispanic White patients, non‐Hispanic Black (NHB) and Hispanic populations are less likely to receive acute treatment for ischemic stroke, and when they do, it can be delayed. We evaluated the interaction between arrival method and race or ethnicity on door‐to‐arterial puncture (DTAP) time in thrombectomy. Methods We conducted a retrospective observational cohort study of consecutive adults who underwent endovascular thrombectomy from 14 US Comprehensive Stroke Centers (January 1, 2019–July 31, 2020). DTAP was assessed in a linear mixed model including an interaction term for race or ethnicity and arrival method. Results Of the 1908 included patients, 356 of whom were Hispanic, Hispanic and NHB patients experienced significant delays in DTAP compared with non‐Hispanic White patients (adjusted βHisp=0.32, 95% CI, 0.08–0.55; βNHB=0.23; 95% CI, 0.04–0.41). More severe deficits were associated with shorter DTAP (βNIHSS per point −0.03; 95% CI −0.04 to −0.03), and arrival via emergency medical services or private vehicle versus transfer were associated with longer delays (βEMS=0.57; 95% CI, 0.41–0.74; βPV=1.27; 95% CI, 0.85–1.70). There was a significant interaction between Hispanic ethnicity and emergency medical services (P=0.03) or private vehicle arrival (P=0.04) in a direction favoring shorter treatment delays. Sites that treated a minority population of Hispanic patients (

Background The Society of Vascular & Interventional Neurology Guidelines and Practice Standards committee established the “Brief Practice Update” format to provide up‐to‐date recommendations on focused clinical topics with emerging clinical trial results. For our inaugural Brief Practice Update, we review current evidence and provide recommendations for administering intravenous thrombolysis before mechanical thrombectomy; combination therapy (mechanical thrombectomy plus intravenous thrombolysis) versus stand‐alone mechanical thrombectomy approach in acute ischemic stroke secondary to emergent large vessel occlusion. Methods The Society of Vascular & Interventional Neurology Guidelines and Practice Standards committee members formed a writing group to review results of the most recent clinical trials of pre‐mechanical thrombectomy intravenous thrombolysis. The group summarized recent clinical data to provide recommendations for clinical practice. Brief Practice Update recommendations were vetted by the Guidelines and Practice Standards quality committee to ensure adherence to Society of Vascular & Interventional Neurology standard evaluation of evidence and endorsement was obtained following formal review by the Board of Directors. Results We present a focused review of recently published clinical trials and a meta‐analysis of combination intravenous thrombolysis and mechanical thrombectomy versus a stand‐alone direct‐to‐mechanical thrombectomy treatment approach in ischemic stroke patients with emergent large vessel occlusion. Level of evidence and class of recommendation were vetted by the Guidelines and Practice Standards committee. Conclusions We share general recommendations on pre‐mechanical thrombectomy thrombolysis, using analysis of available evidence from recent randomized clinical trial data. Recommendations provided by the Society of Vascular & Interventional Neurology Brief Practice Update are not intended to replace an individualized approach to clinical decision making and patient care.

A cyclic coloring of a plane graph is a vertex coloring such that any two vertices incident with the same face receive distinct colors. This type of coloring was introduced more than fifty years ago, and a lot of research in chromatic graph theory was sparked by it. This paper is a survey on the state of the art concerning the cyclic coloring and relaxations of this graph invariant.