182 research outputs found

    Photos of the Titan sub's wreckage support the theory that the carbon-fiber hull failed first, expert says

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    An annotated image of part of the Titan submersible being moved ashore after its catastrophic implosion under the North Atlantic in June 2023. Onlookers caught glimpses of the Titan submersible wreckage as its crews brought its remains ashore. These provide clues to what may have happened while a formal investigation is underway. Though it's difficult to know for sure, an expert said the carbon-fiber hull likely failed firs

    Stochastic Cutoff Method for Long-Range Interacting Systems

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    A new Monte-Carlo method for long-range interacting systems is presented. This method consists of eliminating interactions stochastically with the detailed balance condition satisfied. When a pairwise interaction VijV_{ij} of a NN-particle system decreases with the distance as rijαr_{ij}^{-\alpha}, computational time per one Monte Carlo step is O(N){\cal O}(N) for αd\alpha \ge d and O(N2α/d){\cal O}(N^{2-\alpha/d}) for α<d\alpha < d, where dd is the spatial dimension. We apply the method to a two-dimensional magnetic dipolar system. The method enables us to treat a huge system of 2562256^2 spins with reasonable computational time, and reproduces a circular order originated from long-range dipolar interactions.Comment: 18 pages, 9 figures, 1 figure and 1 reference are adde

    Photoemission time-delay measurements and calculations close to the 3s ionization minimum in Ar

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    We present experimental measurements and theoretical calculations of photoionization time delays from the 3s3s and 3p3p shells in Ar in the photon energy range of 32-42 eV. The experimental measurements are performed by interferometry using attosecond pulse trains and the infrared laser used for their generation. The theoretical approach includes intershell correlation effects between the 3s and 3p shells within the framework of the random phase approximation with exchange (RPAE). The connection between single-photon ionization and the two-color two-photon ionization process used in the measurement is established using the recently developed asymptotic approximation for the complex transition amplitudes of laser-assisted photoionization. We compare and discuss the theoretical and experimental results especially in the region where strong intershell correlations in the 3s to kp channel lead to an induced "Cooper" minimum in the 3s ionization cross-section.Comment: submitted to PR

    Photoemission-time-delay measurements and calculations close to the 3s-ionization-cross-section minimum in Ar

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    We present experimental measurements and theoretical calculations of photoionization time delays from the 3s and 3p shells in Ar in the photon energy range of 32-42 eV. The experimental measurements are performed by interferometry using attosecond pulse trains and the infrared laser used for their generation. The theoretical approach includes intershell correlation effects between the 3s and 3p shells within the framework of the random-phase approximation with exchange. The connection between single-photon ionization and the two-color two-photon ionization process used in the measurement is established using the recently developed asymptotic approximation for the complex transition amplitudes of laser-assisted photoionization. We compare and discuss the theoretical and experimental results, especially in the region where strong intershell correlations in the 3s -> kp channel lead to an induced "Cooper" minimum in the 3s ionization cross section

    Influence of preoperative life satisfaction on recovery and outcomes after colorectal cancer surgery - a prospective pilot study.

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    Colorectal surgery has an important impact on a patient's quality of life, and postoperative rehabilitation shows large variations. To enhance the understanding of recovery after colorectal cancer, health-related quality of life has become a standard outcome measurement for clinical care and research. Therefore, we aimed to correlate the influence of preoperative global life satisfaction on subjective feelings of well-being with clinical outcomes after colorectal surgery. In this pilot study of consecutive colorectal surgery patients, various dimensions of feelings of preoperative life satisfaction were assessed using a self-rated scale, which was validated in French. Both objective (length of stay and complications) and subjective (pain, subjective well-being and quality of sleep) indicators of recovery were evaluated daily during each patient's hospital stay. A total of 112 patients were included. The results showed a negative relationship between life satisfaction and postoperative complications and a significant negative correlation with the length of stay. Moreover, a significant positive correlation between life satisfaction and the combined subjective indicators of recovery was observed. We have shown the importance of positive preoperative mental states and global life satisfaction as characteristics that are associated with an improved recovery after colorectal surgery. Therefore, patients with a good level of life satisfaction may be better able to face the consequences of colorectal surgery, which is a relevant parameter in supportive cancer care

    Hypoxic Environment and Paired Hierarchical 3D and 2D Models of Pediatric H3.3-Mutated Gliomas Recreate the Patient Tumor Complexity.

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    BACKGROUND:Pediatric high-grade gliomas (pHGGs) are facing a very dismal prognosis and representative pre-clinical models are needed for new treatment strategies. Here, we examined the relevance of collecting functional, genomic, and metabolomics data to validate patient-derived models in a hypoxic microenvironment. METHODS:From our biobank of pediatric brain tumor-derived models, we selected 11 pHGGs driven by the histone H3.3K28M mutation. We compared the features of four patient tumors to their paired cell lines and mouse xenografts using NGS (next generation sequencing), aCGH (array comparative genomic hybridization), RNA sequencing, WES (whole exome sequencing), immunocytochemistry, and HRMAS (high resolution magic angle spinning) spectroscopy. We developed a multicellular in vitro model of cell migration to mimic the brain hypoxic microenvironment. The live cell technology Incucyte© was used to assess drug responsiveness in variable oxygen conditions. RESULTS:The concurrent 2D and 3D cultures generated from the same tumor sample exhibited divergent but complementary features, recreating the patient intra-tumor complexity. Genomic and metabolomic data described the metabolic changes during pHGG progression and supported hypoxia as an important key to preserve the tumor metabolism in vitro and cell dissemination present in patients. The neurosphere features preserved tumor development and sensitivity to treatment. CONCLUSION:We proposed a novel multistep work for the development and validation of patient-derived models, considering the immature and differentiated content and the tumor microenvironment of pHGGs
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