Automatic mapping of atoms across both simple and complex chemical reactions

Mapping atoms across chemical reactions is important for substructure searches, automatic extraction of reaction rules, identification of metabolic pathways, and more. Unfortunately, the existing mapping algorithms can deal adequately only with relatively simple reactions but not those in which expert chemists would benefit from computer's help. Here we report how a combination of algorithmics and expert chemical knowledge significantly improves the performance of atom mapping, allowing the machine to deal with even the most mechanistically complex chemical and biochemical transformations. The key feature of our approach is the use of few but judiciously chosen reaction templates that are used to generate plausible "intermediate" atom assignments which then guide a graph-theoretical algorithm towards the chemically correct isomorphic mappings. The algorithm performs significantly better than the available state-of-the-art reaction mappers, suggesting its uses in database curation, mechanism assignments, and - above all - machine extraction of reaction rules underlying modern synthesis-planning programs

Interhospital Transfer Before Thrombectomy Is Associated With Delayed Treatment and Worse Outcome in the STRATIS Registry (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke).

BACKGROUND: Endovascular treatment with mechanical thrombectomy (MT) is beneficial for patients with acute stroke suffering a large-vessel occlusion, although treatment efficacy is highly time-dependent. We hypothesized that interhospital transfer to endovascular-capable centers would result in treatment delays and worse clinical outcomes compared with direct presentation. METHODS: STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) was a prospective, multicenter, observational, single-arm study of real-world MT for acute stroke because of anterior-circulation large-vessel occlusion performed at 55 sites over 2 years, including 1000 patients with severe stroke and treated within 8 hours. Patients underwent MT with or without intravenous tissue plasminogen activator and were admitted to endovascular-capable centers via either interhospital transfer or direct presentation. The primary clinical outcome was functional independence (modified Rankin Score 0-2) at 90 days. We assessed (1) real-world time metrics of stroke care delivery, (2) outcome differences between direct and transfer patients undergoing MT, and (3) the potential impact of local hospital bypass. RESULTS: A total of 984 patients were analyzed. Median onset-to-revascularization time was 202.0 minutes for direct versus 311.5 minutes for transfer patients ( CONCLUSIONS: In this large, real-world study, interhospital transfer was associated with significant treatment delays and lower chance of good outcome. Strategies to facilitate more rapid identification of large-vessel occlusion and direct routing to endovascular-capable centers for patients with severe stroke may improve outcomes. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02239640

Machine learning for molecular and materials science

Here we summarize recent progress in machine learning for the chemical sciences. We outline machine-learning techniques that are suitable for addressing research questions in this domain, as well as future directions for the field. We envisage a future in which the design, synthesis, characterization and application of molecules and materials is accelerated by artificial intelligence.</p

Praca regulatora generatora w warunkach sprzyjających powstawaniu lawiny napięcia - wybrane problemy

W artykule zwrócono uwagę na wybrane zagadnienia związane z pracą wieloparametrowego regulatora generatora w warunkach awarii napięciowej. Przedstawiono wyniki analizy wpływu, tak często pomijanego elementu układu regulatora generatora, jakim jest stabilizator systemowy. Zwrócono uwagę na celowość automatyzacji procesu zaniżania mocy czynnej, dla zwiększenia możliwości generacji mocy biernej. Ponadto, wskazano błędy w strukturze toru głównego regulacji napięcia w przypadku układu z tzw. przejmowaniem sygnałów przez bramki LV i HV

Wykorzystanie przebiegów rejestracji szybkozmiennych do weryfikacji modeli dynamicznych KSE

W artykule przedstawiono koncepcję narzędzia pozwalającego na weryfikowanie parametrów modeli dynamicznych elementów KSE. Narzędzie wykorzystuje program obliczeniowy PSLF, stosowany powszechnie przez operatora systemu przesyłowego. Nowatorstwo polega na wykorzystaniu dodatkowej aplikacji (programu w systemie MS Windows), która steruje pracą programu obliczeniowego. Powstaje w ten sposób tandem wygodnego interfejsu użytkownika, umożliwiającego sterowanie i analizowanie uzyskiwanych wyników, oraz programu obliczeniowego – silnika pozwalającego na symulowanie stanów pracy systemu elektroenergetycznego. Algorytmy optymalizacyjne zawarte w aplikacji dopasowują odpowiedź uzyskiwaną z symulacji do rzeczywistego przebiegu, zarejestrowanego na podlegającym weryfikacji obiekcie, oceniając poprawność danego modelu

Improving sensitivity of residual current transformers to high frequency earth fault currents

For protection against electric shock in low voltage systems residual current devices are commonly used. However, their proper operation can be interfered when high frequency earth fault current occurs. Serious hazard of electrocution exists then. In order to detect such a current, it is necessary to modify parameters of residual current devices, especially the operating point of their current transformer. The authors proposed the modification in the structure of residual current devices. This modification improves sensitivity of residual current devices when high frequency earth fault current occurs. The test of the modified residual current device proved that the authors’ proposition is appropriate

O-005 Influence of Balloon, Conventional, or Distal Catheters on Angiographic and Technical Outcomes in STRATIS

Introduction/purposeHigher rates of successful revascularization with the least number of passes correlate with improved clinical outcomes in acute stroke endovascular treatment. Different adjunctive technical approaches such as proximal flow arrest using balloon guide catheter (BGC), large bore conventional guide catheter (CGC), or distal large bore catheter (DLBC) with lesional or regional aspiration, are aimed at improving revascularization rates. We present an interim analysis of adjunctive techniques and angiographic outcomes from the STRATIS Registry.Materials and methodsThe STRATIS registry is a prospective, multicenter study of patients with large vessel occlusion (LVO) treated with the Solitaire Stentriever ≤8 hours of symptoms onset. Technical approaches were grouped based on the first technique implemented: BGC; CGC; and DLBC. Posterior circulation target vessel occlusion and subjects with combined BGC and DLBC approach were excluded. A Core Lab extrapolated the techniques from the procedural reports. Baseline variables were compared between the three groups. The main angiographic and technical outcomes were: 1) First pass effect (FPE) defined as successful recanalization of ≥TICI2b, 2) True FPE defined as TICI 3 after first pass with Solitaire; 3) Number of passes among the cohorts.Results413 anterior circulation subjects were included in this interim analysis. The initial technical approach was 60% BGC, 30% DLBC, and 10% CGC. The groups were well balanced in reference to baseline and demographic factors. The rates of FPE were: 62%, 51%, and 45% (P = 0.0336), while the true FPE rates were: 44% vs. 37% vs. 28% (P = 0.0996) with BGC, DLBC, and CGC, respectively. The mean number of passes were: 1.7 ± 1.09, 2.1 ± 1.42, and 2.2 ± 1.76 (P = 0.0085), with BGC, DLBC, and CGC, respectively. The rates of successful recanalization of ≥TICI2b after all passes were 91.9% BGC, 88.8% DLBC, and 87.5% CGC (P = 0.4945).ConclusionThe STRATIS registry interim analysis demonstrated a higher use of BGC as first approach (60%) compared to previous reports. Consistent with published data, BGC is associated with higher rates of successful revascularization and a trend toward higher rates of complete revascularization from the first pass. Moreover, a lower number of passes is associated with BGC use compared to CGC and DLBC. DLBC with lesional and regional aspiration appears to be superior to CGC only. These results are preliminary, and further analysis with final planned sample size and correlation with central blinded core lab imaging data will provide further evidence on technical and angiographic outcomes with different adjunctive approaches.DisclosuresO. Zaidat: 2; C; Medtronic Neurovascular. D. Liebeskind: 1; C; NIH-NINDS. 2; C; Medtronic Neurovascular, Stryker. R. Jahan: 1; C; Medtronic Neurovascular. 2; C; Medtronic Neurovascular. M. Froehler: 2; C; Medtronic Neurovascular. 6; C; Site PI (Large, Liberty, SCENT, Feat, Barrel, Atlas, Rhapsody, Positive, Sep 3D) payment to institution. M. Aziz-Sultan: 2; C; Medtronic Neurovascular. 6; C; Expert Witness - BMC. R. Klucznik: 3; C; Medtronic Neurovascular. J. Saver: 2; C; Medtronic Neurovascular, Stryker, Neuravia, Cognition Medical, Boehringer Ingelheim (prevention only). D. Yavagal: 2; C; Medtronic Neurovascular. 6; C; ESCAPE trial DSCMB member. N. Mueller-Kronast: 2; C; Medtronic Neurovascular