142 research outputs found

    Liouville integrability of a class of integrable spin Calogero-Moser systems and exponents of simple Lie algebras

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    In previous work, we introduced a class of integrable spin Calogero-Moser systems associated with the classical dynamical r-matrices with spectral parameter, as classified by Etingof and Varchenko for simple Lie algebras. Here the main purpose is to establish the Liouville integrability of these systems by a uniform method

    Selective Autophagy of BES1 Mediated by DSK2 Balances Plant Growth and Survival

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    Plants encounter a variety of stresses and must fine-tune their growth and stress-response programs to best suit their environment. BES1 functions as a master regulator in the brassinosteroid (BR) pathway that promotes plant growth. Here, we show that BES1 interacts with the ubiquitin receptor protein DSK2 and is targeted to the autophagy pathway during stress via the interaction of DSK2 with ATG8, a ubiquitin-like protein directing autophagosome formation and cargo recruitment. Additionally, DSK2 is phosphorylated by the GSK3-like kinase BIN2, a negative regulator in the BR pathway. BIN2 phosphorylation of DSK2 flanking its ATG8 interacting motifs (AIMs) promotes DSK2-ATG8 interaction, thereby targeting BES1 for degradation. Accordingly, loss-of-function dsk2 mutants accumulate BES1, have altered global gene expression profiles, and have compromised stress responses. Our results thus reveal that plants coordinate growth and stress responses by integrating BR and autophagy pathways and identify the molecular basis of this crosstalk

    Histone Lysine Methyltransferase SDG8 Is Involved in Brassinosteroid-Regulated Gene Expression in Arabidopsis thaliana

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    Citation: Wang, X., Chen, J., Xie, Z., Liu, S., Nolan, T., Ye, H., et al. (2014). Histone lysine methyltransferase SDG8 is involved in brassinosteroid- regulated gene expression in arabidopsis thaliana.The plant steroid hormones, brassinosteroids (BRs), play important roles in plant growth, development and responses to environmental stresses. BRs signal through receptors localized to the plasma membrane and other signaling components to regulate the BES1/BZR1 family of transcription factors, which modulates the expression of 4,000-5,000 genes. How BES1/BZR1 and their interacting proteins function to regulate the large number of genes are not completely understood. Here we report that histone lysine methyltransferase SDG8, implicated in Histone 3 lysine 36 di- and tri-methylation (H3K36me2 and me3), is involved in BR-regulated gene expression. BES1 interacts with SDG8, directly or indirectly through IWS1, a transcription elongation factor involved in BR-regulated gene expression. The knockout mutant sdg8 displays a reduced growth phenotype with compromised BR responses. Global gene expression studies demonstrated that SDG8 plays a major role in BR-regulated gene expression as more than half of BR-regulated genes are differentially affected in sdg8 mutant. A Chromatin Immunoprecipitation (ChIP) experiment showed that H3K36me3 is reduced in BR-regulated genes in the sdg8 mutant. Based on these results, we propose that SDG8 plays an essential role in mediating BR-regulated gene expression. Our results thus reveal a major mechanism by which histone modifications dictate hormonal regulation of gene expression

    Severe Stroke Patients With Left-Sided Occlusion of the Proximal Anterior Circulation Benefit More From Thrombectomy

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    Background and Purpose: Endovascular thrombectomy improves the functional independence of patients with proximal anterior circulation occlusion. However, a subset of patients fail to benefit from thrombectomy procedures, the reasons for which remain poorly defined. In this study, we investigated whether the effectiveness of thrombectomy was affected by left- or right-sided occlusion among patients with similar stroke severities.Methods: Patients with proximal anterior circulation occlusion (internal carotid or M1 of middle cerebral artery) treated with the Solitaire stent retriever within 8 h of the onset of acute ischemic stroke were enrolled from the Yijishan Hospital of Wannan Medical College. Stroke severity was measured using the National Institutes of Health Stroke Scale (NIHSS) on admission. The functional outcomes were assessed using the modified Rankin scale (mRS) at 90 days.Results: We enrolled 174 patients including 90 left-sided occlusion and 84 right-sided occlusion. The NIHSS scores on admission were higher in the left-sided (median, 19; interquartile range, 16 to 20) compared to the right-sided occlusion group (median, 15, interquartile range, 13 to 18) (P < 0.001). Following adjustment for potential risk factors, patients with left-sided occlusion had higher rates of functional independence (mRS ≤ 2) and lower rates of mortality (mRS = 6) compared to the right-sided occlusion patients (39.5 vs. 19.6% and 28.9 vs. 47.8%, respectively) in the severe stroke group (NIHSS ≥ 15).Conclusions: In severe stroke patients with proximal anterior circulation occlusion, stent retriever thrombectomy within 8 h of the onset of symptoms provides more benefits to left-sided occlusion

    New insights into the interplay between autophagy and cartilage degeneration in osteoarthritis

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    Autophagy is an intracellular degradation system that maintains the stable state of cell energy metabolism. Some recent findings have indicated that autophagy dysfunction is an important driving factor for the occurrence and development of osteoarthritis (OA). The decrease of autophagy leads to the accumulation of damaged organelles and macromolecules in chondrocytes, which affects the survival of chondrocytes and ultimately leads to OA. An appropriate level of autophagic activation may be a new method to prevent articular cartilage degeneration in OA. This minireview discussed the mechanism of autophagy and OA, key autophagy targets regulating OA progression, and evaluated therapeutic applications of drugs targeting autophagy in preclinical and clinical research. Some critical issues worth paying attention to were also raised to guide future research efforts

    SegRap2023: A Benchmark of Organs-at-Risk and Gross Tumor Volume Segmentation for Radiotherapy Planning of Nasopharyngeal Carcinoma

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    Radiation therapy is a primary and effective NasoPharyngeal Carcinoma (NPC) treatment strategy. The precise delineation of Gross Tumor Volumes (GTVs) and Organs-At-Risk (OARs) is crucial in radiation treatment, directly impacting patient prognosis. Previously, the delineation of GTVs and OARs was performed by experienced radiation oncologists. Recently, deep learning has achieved promising results in many medical image segmentation tasks. However, for NPC OARs and GTVs segmentation, few public datasets are available for model development and evaluation. To alleviate this problem, the SegRap2023 challenge was organized in conjunction with MICCAI2023 and presented a large-scale benchmark for OAR and GTV segmentation with 400 Computed Tomography (CT) scans from 200 NPC patients, each with a pair of pre-aligned non-contrast and contrast-enhanced CT scans. The challenge's goal was to segment 45 OARs and 2 GTVs from the paired CT scans. In this paper, we detail the challenge and analyze the solutions of all participants. The average Dice similarity coefficient scores for all submissions ranged from 76.68\% to 86.70\%, and 70.42\% to 73.44\% for OARs and GTVs, respectively. We conclude that the segmentation of large-size OARs is well-addressed, and more efforts are needed for GTVs and small-size or thin-structure OARs. The benchmark will remain publicly available here: https://segrap2023.grand-challenge.orgComment: A challenge report of SegRap2023 (organized in conjunction with MICCAI2023

    Optimizing the Mechanical Performance and Microstructure of Alkali-Activated Soda Residue-Slag Composite Cementing Materials by Various Curing Methods

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    Aiming to promote further the application of alkali-activated soda residue-ground granulated blast furnace slag (SR-GGBS) cementing materials, this study explored the optimal curing method for enhancing mechanical performance. The optimal curing method was determined based on the development of compressive strengths at different curing periods and microstructural examination by XRD, FTIR, SEM, and TG-DTG. The results show that the strength of cementing materials after room-temperature (RT) dry curing was the poorest, with the slow development of mechanical performance. The 7d and 28d compressive strengths were only 14.62 and 20.99 MPa, respectively. Compared with the values after RT dry curing, the samples’ 7d and 28d compressive strengths after RT water curing, standard curing, and RT sealed curing were enhanced by 16.35%/24.06%, 30.98%/23.77%, and 38.24%/37.97%, respectively. High-temperature (HT) curing can significantly improve the early strength of the prepared cementing materials. Curing at 60 °C for 12 h was the optimal HT curing method. Curing at 60 °C for 12 h enhanced the 3d strength by 100.84% compared with standard curing. This is because HT curing promoted the decomposition and aggregation of GGBS, and more C-A-S-H gel and crystal hydration products, including ettringite and calcium chloroaluminate hydrate, were produced and filled the inner pores, thereby enhancing both the overall compactness and mechanical performance. However, curing at too high temperatures for too long can reduce the material’s overall mechanical performance. After excess HT curing, many shrinkage cracks were produced in the sample. Different thermal expansion coefficients of different materials led to a decline in strength. The present study can provide a theoretical foundation for extensive engineering applications of alkali-activated SR-GGBS composite cementing materials

    Mechanical Properties and Microstructure of Alkali-Activated Soda Residue-Blast Furnace Slag Composite Binder

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    This study prepared an alkali-activated soda residue (SR)-blast furnace slag (BFS) composite binder by adding a large amount of SR to the alkali-activated material system. Considering many factors, such as the Na2O content, ratio of SR to BFS and the water-binder ratio, the variation patterns in the new binder’s mechanical properties and its micro-evolution mechanisms were assessed. The results show that the compressive strength first grew and then dropped with the Na2O content, with an optimal level at 3.0%. At this level, the strength values of the 3d and 28d samples were 10.5 and 27.8 MPa, respectively, exceeding those in the control group without Na2O by 337.5 and 69.5%, respectively. As the Na2O admixture increased from 0 to 3%, the fluidity of the mortar decreased from 156 mm to 127 mm due to the high frictional resistance caused by the faster generation of hydration products, and the high water absorption of SR also led to reduced fluidity. The new binder’s hydration process mainly generated C-(A)-S-H gel, ettringite (ET), hydrocalumite (HC), calcium hydroxide (CH), and other crystalline hydrates. A 3% Na2O content inhibited the ET growth but significantly promoted the formation of uniformly distributed C-(A)-S-H gel and HC. Crystals grew in the pores or were interspersed in the gel, filling microcracks and significantly increasing the structure density and strength. Excessive Na2O (>3%) could promote the generation of non-uniformly distributed gel, producing more macropores in the matrix and reducing its strength. Additionally, the increased SR content was not conducive to C-(A)-S-H gel formation, but significantly promoted ET formation, which would inhibit strength development. This study provides a theoretical basis for replacing cement with this new binder in pavement bricks and other unreinforced products
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