Nanostructural Deformation Analysis of Calcium Silicate Hydrate in Portland Cement Paste by Atomic Pair Distribution Function

The deformation of nanostructure of calcium silicate hydrate (C-S-H) in Portland cement (PC) paste under compression was characterized by the atomic pair distribution function (PDF), measured using synchrotron X-ray diffraction. The PDF of the PC paste exhibited a unique deformation behavior for a short-range order below 2.0 nm, close to the size of the C-S-H globule, while the deformation for a long-range order was similar to that of a calcium hydroxide phase measured by Bragg peak shift. The compressive deformation of the C-S-H nanostructure was comprised of three stages with different interactions between globules. This behavior would originate from the granular nature of C-S-H, which deforms with increasing packing density by slipping the interfaces between globules, rearranging the overall C-S-H nanostructure. This new approach will lead to increasing applications of the PDF technique to understand the deformation mechanism of C-S-H in PC-based materials

Claw sign predicts first-pass effect in MT

Background: Mechanical thrombectomy (MT) is an effective treatment for acute cerebral large vessel occlusion (LVO). Complete recanalization of vessels in a single procedure is defined as the first-pass effect (FPE) and is associated with good prognosis. In this study, angiographic clot protruding sign termed the “claw sign,” was examined as candidate preoperative imaging factor for predicting the FPE. Methods: We retrospectively analyzed data from 91 consecutive patients treated for acute LVO in the anterior circulation by MT between January 2014 and December 2019. The claw sign was defined as a thrombus that protruded proximally by more than half of the diameter of the parent artery. Radiological findings such as claw sign, clinical and etiological features, and outcomes were compared between groups with and without successful FPE. Multivariate analysis was conducted to evaluate perioperative factors associated with FPE. Results: FPE was achieved in 26 of 91 (28.6%) patients and the claw sign was observed in 34 of 91 (37.4%) patients. The claw sign was significantly more frequent in the successful FPE group than in the failed FPE group (53.8% vs. 30.8%; P = 0.040). After the multivariate analysis, the claw sign was the only pretreatment parameter that could predict FPE (odds ratio, 2.67; 95% confidence interval, 1.01–7.06; P = 0.047). Conclusion: The claw sign is an angiographic imaging factor that might predict FPE after MT for anterior circulation acute ischemic stroke

The predictor of LVO with low NIHSS

Background : Intravenous recombinant tissue plasminogen activator (IV rt-PA) and endovascular treatment have been performed for severe large vessel occlusion (LVO) and the results have been reported at high levels of evidence. However, acute treatment for LVO with mild symptom remains controversial. We retrospectively examined prognostic factors for LVO with mild symptoms. Method : We studied retrospectively the patients within 24 h of onset with large vessel occlusion with NIHSS score ≤ 5. Outcomes were evaluated by modified Rankin Scale (mRS) at 90 days, with 0–2 defined as a good outcome and 3–6 as a poor outcome. Clinical characteristics of each case were examined. Result : Participants comprised 76 patients. Of the 76 patients. ICA occlusion showed good outcome in 17 / 19 cases (90%), whereas MCA occlusion showed good outcome in 36 / 54 cases (67%). Among the 14 cases showing positive results for distal intraarterial signal (d-IAS), outcomes were good in 6 cases (43%). On the other hand, the 32 d-IAS-negative cases showed good outcome in 28 cases (88%). Outcomes were thus significantly poorer for d-IAS-positive cases. Conclusion : MCA occlusion is associated with poor prognosis, even with NIHSS score ≤ 5, and d-IAS may provide a predictor

INVOLVEMENT OF NETS IN CEREBRAL AVM

BACKGROUND: Cerebral arteriovenous malformations (cAVMs) represent tangles of abnormal vasculature without intervening capillaries. High-pressure vascular channels due to abnormal arterial and venous shunts can lead to rupture. Multiple pathways are involved in the pathobiology of cAVMs including inflammation and genetic factors such as KRAS mutations. Neutrophil release of nuclear chromatin, known as neutrophil extracellular traps (NETs), plays a multifunctional role in infection, inflammation, thrombosis, intracranial aneurysms, and tumor progression. However, the relationship between NETs and the pathobiology of cAVMs remains unknown. We tested whether NETs play a role in the pathobiology of cAVMs. METHODS: We analyzed samples from patients who had undergone surgery for cAVM and immunohistochemically investigated expression of citrullinated histone H3 (CitH3) as a marker of NETs. CitH3 expression was compared among samples from cAVM patients, epilepsy patients, and normal human brain tissue. Expressions of thrombotic and inflammatory markers were also examined immunohistochemically in samples from cAVM patients. RESULTS: Expression of CitH3 derived from neutrophils was observed intravascularly in all cAVM samples but not other samples. Nidi of AVMs showed migration of many Iba-I-positive cells adjacent to the endothelium and endothelial COX2 expression, accompanied by expression of IL-6 and IL-8 in the endothelium and intravascular neutrophils. Unexpectedly, expression of CitH3 was not necessarily localized to the vascular wall and thrombus. CONCLUSIONS: Our results offer the first evidence of intravascular expression of NETs, which might be associated with vascular inflammation in cAVMs

Implementing action for acute stroke based on Japanese National Plan for Promotion of Measures Against Cerebrovascular and Cardiovascular Disease in Tokushima

Cerebrovascular and cardiovascular disease are the main causes of death in Japan. The leading causes of the need for long-term care in Japan are also cerebrovascular and cardiovascular disease, which together account for more than one-fourth of the total. The Cerebrovascular and Cardiovascular Disease Control Act, of Japanese national law, was promulgated by a legislative act in 2018. On the basis of the Cerebrovascular and Cardiovascular Disease Control Act, the Ministry of Health, Labour and Welfare, Japan, published the Japanese National Plan for Promotion of Measures Against Cerebrovascular and Cardiovascular Disease （Japanese National Plan） in 2020. By the example of the Japanese National Plan, Tokushima prefecture established a cerebrovascular and cardiovascular disease countermeasure promotion plan to progress cerebrovascular and cardiovascular disease measures according to their own circumstances. One of the important measures of the plan is improving emergency transportation systems. Patients with intracranial large vessel occlusion strokes should be served by direct transfer to endovascular capable centers avoiding delays by misguided transfer to primary stroke centers. Considering the limited availability of endovascular capable centers, accurate identification of patients with high probability of having large vessel occlusion strokes in the prehospital setting is importance. To address this problem, we introduced prehospital scale called Field Assessment Stroke Triage for Emergency Destination （FAST-ED） on emergency transportation systems in Tokushima city

Editing range compensator for sparing normal tissue in treatment planning

When using two-dimensional beam delivery in particle radiotherapy, the location of the spread out Bragg peak can be an issue in terms of the dose to normal tissue in the proximity of the planning target volume. We propose a method for modifying the irradiated volume that keeps a high dose deposit for the target, using an editing for fabrication data of range compensator. This method is effective when the normal tissue to be spared is located upstream of the target volume. A simple software tool was developed to demonstrate the effectiveness and impact of making an alternative treatment plan. The dose delivered to normal tissues could be decreased in the limited volume. This method could be helpful in devising treatment plans that spare critical tissues by the evaluation of dose distributions and dose-area/volume histograms.WORLD CONGRESS 200