69 research outputs found

    Reductions and symmetries for a generalized Fisher equation with a diffusion term dependent on density and space

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    In this work, a generalized Fisher equation with a space–density diffusion term is analyzed by applying the theory of symmetry reductions for partial differential equations. The study of this equation is relevant in terms of its applicability in cell dynamics and tumor invasion. Therefore, classical Lie symmetries admitted by the equation are determined. In addition, by using the multipliers method, we derive some nontrivial conservation laws for this equation. Finally we obtain a direct reduction of order of the ordinary differential equations associated and a particular solution

    Exact solutions through symmetry reductions for a high-grade brain tumor model with response to hypoxia.

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    Mathematical biology models can simulate cell behavior scenarios, specifically for tumor proliferation. In this paper, we study a continuous model describing the evolution of high-grade gliomas from the point of view of the theory of symmetry reductions in partial differential equations (PDEs). Malignant gliomas are the most frequent and deadly type of brain tumor. Over the last few years, complex mathematical models of cancerous growths have been developed increasingly, especially on solid tumors, in which growth primarily comes from abnormal cellular proliferation. The presented PDE system includes two different cellular phenotypes, depending on their oxygenation level. Furthermore, this mathematical model assumes that both phenotypes differ in migration and proliferation rates. Specifically, it includes the possibility of hypoxic cells diffusing into well-oxygenated areas of a tumor. Our main findings are obtained through the classical symmetries admitted by the proposed system, and transformation groups are used to reduce the PDE system to ordinary differential equations. By these means, we provide not only exact solutions but also capture a 3-dimensional representation of the biological phenomenon. The simulations provided show the relationship between normoxic and hypoxic phenotypes in high-grade gliomas

    Boundary objects : sustainability reporting and the production of organizational stability

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    Purpose The study investigates how sustainability reporting constructs a narrative about an organization that provides its members with a reality they can accept, with the consequence of producing organizational stability. Design/methodology/approach The article reports a research engagement concerning the “backstage” of sustainability reporting in one Spanish savings bank, which the researchers engaged with for more than three years. Findings The article describes how sustainability reporting operates as a boundary object occupying the space between the organization’s loosely coupled systems and facilitating the cooperation of members with different interpretations of the organization. Different translations of discourses and actions ensure that the sustainability report conveys a ductile narrative that can be tailored to specific interpretations. At the same time, the editing inherent in sustainability reporting ensures that any narrative that may challenge the organization’s dominant perspective is ignored and marginalized. In this way, sustainability reporting produces a discourse that inscribes a narrative of the organization and eventually ensures organizational inertia. Research limitations/implications The article highlights the relevance of investigating sustainability reports by exploring the backstage of their production rather than solely the final document. Originality/value In contrast to prior research that has been concerned with exploring the extent to which sustainability reporting is associated with organizational change, this study applies different lenses to show how and why sustainability reporting is implicated in the construction of the organization and the maintenance of its stability and inertia

    Gentiopicroside Ameliorates Diabetic Peripheral Neuropathy by Modulating PPAR- Γ/AMPK/ACC Signaling Pathway

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    Background/Aims: Gentiopicroside is promising as an important secoiridoid compound against pain. The present study aimed to investigate the analgesic effect and the probable mechanism of Gentiopicroside on Diabetic Peripheral Neuropathy (DPN), and to figure out the association among Gentiopicroside, dyslipidemia and PPAR- γ/AMPK/ACC signaling pathway. Methods: DPN rat models were established by streptozotocin and RSC96 cells were cultured. Hot, cold and mechanical tactile allodynia were conducted. Blood lipids, nerve blood flow, Motor Nerve Conduction Velocity (MNCV) and Sensory Nerve Conduction Velocity (SNCV) were detected. Gene and protein expression of PPAR- γ/AMPK/ACC pathway was analyzed by reverse transcription-quan titative polymerase chain reaction (RT-qPCR) and Westernblot. Besides, PPAR-γ antagonist GW9662 and agonist rosiglitazone, AMPK antagonist compound C and activator AICAR as well as ACC inhibitor TOFA were used to further confirm the relationship between PPAR-γ and AMPK. Results: The results demonstrated that Gentiopicroside markedly ameliorated hyperalgesia with prolonged paw withdrawal latency to heat and cold stimuli and fewer responses to mechanical allodynia compared with DPN model group. Gentiopicroside regulated dyslipidemia, enhanced nerve blood flow and improved MNCV as well as SNCV. Gentiopicroside suppressed ACC expression through the activation of AMPK and PPAR-γ mediated the activation of AMPK and subsequent inhibition of ACC expression. Conclusion: In conclusion, the present study demon strated that Gentiopicroside exerted nerve-protective effect and attenuated experimental DPN by restoring dyslipidmia and improved nerve blood flow through regulating PPAR-γ/AMPK/ACC signal pathway. These results provided a promising potential treatment of DPN

    CAR T cell therapy in B-cell acute lymphoblastic leukaemia: Insights from mathematical models

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    Immunotherapies use components of the patient immune system to selectively target cancer cells. The use of CAR T cells to treat B-cell malignancies --leukaemias and lymphomas-- is one of the most successful examples, with many patients experiencing long-lasting complete responses to this therapy. This treatment works by extracting the patient's T cells and adding them the CAR group, which enables them to recognize and target cells carrying the antigen CD19+, that is expressed in these haematological tumors. Here we put forward a mathematical model describing the time response of leukaemias to the injection of CAR T-cells. The model accounts for mature and progenitor B-cells, tumor cells, CAR T cells and side effects by incorporating the main biological processes involved. The model explains the early post-injection dynamics of the different compartments and the fact that the number of CAR T cells injected does not critically affect the treatment outcome. An explicit formula is found that provides the maximum CAR T cell expansion in-vivo and the severity of side effects. Our mathematical model captures other known features of the response to this immunotherapy. It also predicts that CD19+ tumor relapses could be the result of the competition between tumor and CAR T cells analogous to predator-prey dynamics. We discuss this fact on the light of available evidences and the possibility of controlling relapses by early re-challenging of the tumor with stored CAR T cells

    (E)-1-[1-(6-Bromo-2-oxo-2H-chromen-3-yl)ethyl­idene]thio­semicarbazide

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    The title compound, C12H10BrN3O2S, exists in an E configuration with respect to the C=N bond. The approximately planar 2H-chromene ring system [maximum deviation = 0.059 (1) Å] is inclined at a dihedral angle of 17.50 (5)° with respect to the mean plane through the thio­semicarbazide unit and an intra­molecular N—H⋯N hydrogen bond generates an S(5) ring. In the crystal structure, adjacent mol­ecules are linked by N—H⋯S hydrogen bonds, forming [010] chains built up from R 2 2(8) loops, such that each S atom accepts two such bonds. These chains are further inter­connected into sheets parallel to the ab plane via short Br⋯O inter­actions [3.0732 (13) Å] and a π–π aromatic stacking inter­action [3.7870 (8) Å] is also observed

    Association between intraoperative dexmedetomidine and all-cause mortality and recurrence after laparoscopic resection of colorectal cancer: Follow-up analysis of a previous randomized controlled trial

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    BackgroundDexmedetomidine (DEX) has been widely applied in the anesthesia and sedation of patients with oncological diseases. However, the potential effect of DEX on tumor metastasis remains contradictory. This study follows up on patients who received intraoperative DEX during laparoscopic resection of colorectal cancer as part of a previous clinical trial, examining their outcomes 5 years later.MethodsBetween June 2015 and December 2015, 60 patients undergoing laparoscopic colorectal resection were randomly assigned to the DEX and control groups. The DEX group received an initial loading dose of 1μ/kg before surgery, followed by a continuous infusion of 0.3μg/kg/h during the operation and the Control group received an equivalent volume of saline. A 5-year follow-up analysis was conducted to evaluate the overall survival, disease-free survival, and tumor recurrence.ResultsThe follow-up analysis included 55 of the 60 patients. The DEX group included 28 patients, while the control group included 27 patients. Baseline characteristics were comparable between the two groups, except for vascular and/or neural invasion of the tumor in the DEX group (9/28 vs. 0/27, p = 0.002). We did not observe a statistically significant benefit but rather a trend toward an increase in overall survival and disease-free survival in the DEX group, 1-year overall survival (96.4% vs. 88.9%, p = 0.282), 2-year overall survival (89.3% vs. 74.1%, p = 0.144), 3-year overall survival (89.3% vs. 70.4%, p = 0.08), and 5-year overall survival (78.6% vs. 59.3%, p = 0.121). The total rates of mortality and recurrence between the two groups were comparable (8/28 vs. 11/27, p = 0.343).ConclusionAdministration of DEX during laparoscopic resection of colorectal cancer had a nonsignificant trend toward improved overall survival and disease-free survival.Clinical Trial Registrationhttp://www.chictr.org.cn/, identifier ChiCTRIOR-15006518

    Computational flow cytometry immunophenotyping at diagnosis is unable to predict relapse in childhood B-cell Acute Lymphoblastic Leukemia

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    B-cell Acute Lymphoblastic Leukemia is the most prevalent form of childhood cancer, with approximately 15% of patients undergoing relapse after initial treatment. Further advancements depend on novel therapies and more precise risk stratification criteria. In the context of computational flow cytometry and machine learning, this paper aims to explore the potential prognostic value of flow cytometry data at diagnosis, a relatively unexplored direction for relapse prediction in this disease. To this end, we collected a dataset of 252 patients from three hospitals and implemented a comprehensive pipeline for multicenter data integration, feature extraction, and patient classification, comparing the results with existing algorithms from the literature. The analysis revealed no significant differences in immunophenotypic patterns between relapse and non-relapse patients and suggests the need for alternative approaches to handle flow cytometry data in relapse prediction

    Use of anticoagulants and antiplatelet agents in stable outpatients with coronary artery disease and atrial fibrillation. International CLARIFY registry

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    Inter-warp divergence aware execution on GPUs

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