166 research outputs found

    Interactive shape design using volumetric implicit PDEs

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    ABSTRACT Solid modeling based on Partial Differential Equations (PDEs) can potentially unify both geometric constraints and functional requirements within a single design framework to model real-world objects via its explicit, direct integration with parametric geometry. In contrast, implicit functions indirectly define geometric objects as the level-set of underlying scalar fields. To maximize the modeling potential of PDEbased methodology, in this paper we tightly couple PDEs with volumetric implicit functions in order to achieve interactive, intuitive shape representation, manipulation, and deformation. In particular, the unified approach can reconstruct the PDE geometry of arbitrary topology from scattered data points or a set of sketch curves. We make use of a fourth-order elliptic PDE to define the volumetric implicit function. The proposed implicit PDE model has the capability to reconstruct a complete solid model from partial information and facilitates the direct manipulation of underlying volumetric datasets via sketch curves, iso-surface sculpting, deformation of arbitrary interior regions, as well as a set of CSG operations inside the working space. The prototype system that we have developed allows designers to interactively sketch the curve outlines of the object, define intensity values and gradient directions, and specify interpolatory points in the 3D working space. The governing implicit PDE treats these constraints as generalized boundary conditions to determine the unknown scalar intensity values over the entire working space. The implicit shape is reconstructed with specified intensity value accordingly and can be deformed using a set of sculpting toolkits. We use the finite-difference discretization and variational interpolating approach with the localized iterative solver for the numerical integration of our PDEs in order to accommodate the diversity of generalized boundary constraints

    Efficacy and safety of Danhong injection for treating myocardial infarction: a systematic review and meta-analysis of randomized controlled trials

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    ObjectiveDanhong injection (DHI) is widely used in the treatment of myocardial infarction (MI). We aimed to systematically review the efficacy and safety of DHI in a randomized controlled experiment on MI.MethodsWe searched the randomized controlled trials (RCTs) of DHI for MI published before 2 April 2023 in China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (CBM), Wanfang database, China Science and Technology Journal Database (VIP), PubMed, Web of Science, Cochrance Library, and Embase databases. The methodological quality of the included studies was evaluated using the Cochrane Handbook 5.3 criteria using the RevMan software, and meta-analysis was performed and a forest map was drawn.ResultsA total of 38 trials included 3877 patients, including 2022 cases in the DHI treatment group and 1855 cases in the control group. Meta-analysis showed that the total effective rate (RR = 1.18%, 95% CI [1.14–1.12]) during treatment with DHI was higher than that of the control group. The prevalence of cardiac arrhythmia (RR = 0.55%, 95% CI [0.46–0.65]) was lower than that of the control group. The incidence of heart rate failure (RR = 0.45%, 95% CI [0.30–0.70]) was lower than that of the control group. The prevalence of cardiogenic shock (RR = 0.33%, 95% CI [0.11–1.04]) was p > 0.05, and the difference was not statistically significant. There was no statistically significant difference in LVEF between the two groups (MD = 0.00%, 95% CI [0.00–0.00]). CK-MB (MD = −0.81%, 95% CI [−0.92∼ −0.69]) was lower than the control group. hs-CRP (MD = −1.09, 95% CI [−1.22∼ −0.97]) was lower than the control group. The incidence of adverse reactions (RR = 0.37, The 95% CI [0.17–0.82]) was lower than that in the control group.ConclusionBasing on our study, the use of DHI in the treatment of myocardial infarction patients is effective, can improve cardiac function, reduce the incidence of adverse reactions, and improve the overall quality of life.Systematic Review Registrationhttps://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023390973

    Recruitment of beneficial cucumber rhizosphere microbes mediated by amino acid secretion induced by biocontrol Bacillus subtilis isolate 1JN2

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    IntroductionAt present, the use of beneficial microorganisms to control cucumber Fusarium wilt is a widely used method, and the rhizosphere microecological reset is one of the mechanisms involved. However, how biocontrol strains reshape cucumber rhizosphere microecology remains to be further studied.MethodsThe composition changes of cucumber root exudates induced by biocontrol strain 1JN2, the microbial ecology of cucumber rhizosphere and the colonization ability of biocontrol strain 1JN2 in cucumber rhizosphere were analyzed through UHPLC-MS/MS analysis, Illumina high-throughput sequencing and SEM, respectively.ResultsFirst, cucumber plants treated with biocontrol Bacillus 1JN2 reduced the disease severity of Fusarium wilt by 60%. Significant changes in cucumber root exudates were found after 1JN2 inoculation and the contents of four amino acids including glutamine, tryptophan, glycine and glutamic acid were significantly increased. Second, It was found that the bacterial diversity in the rhizosphere of cucumber was significantly increased in both the strain treatment group and the amino acid mixture treatment group, The number of Bacillus was the largest in all dominant populations, exceeded 20% in all treatment groups. The bacteria of Hydrogenispora and Vicinamibacteria were significantly increased after treatment.DiscussionOverall, the results demonstrated that amino acid substances in cucumber root exudates induced by biocontrol strain 1JN2 can shift the cucumber root microenvironment and prevent the occurrence of Fusarium wilt disease

    Comparison of out-of-plane short axis with in-plane long axis for ultrasound-guided radial arterial cannulation: A systematic review with trial sequential analysis of randomised controlled trials

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    BackgroundIt is controversial whether the short-axis out-of-plane or long-axis in-plane approach is a better needling technique for ultrasound-guidance radial artery cannulation. We aimed to compare the efficacy and safety of the two approaches for ultrasound-guided radial artery cannulation.MethodsA systematic search of Medline, Embase, the Cochrane Library, and Web of Science for relevant articles published until 1 May 2021 was conducted. Randomised controlled trials comparing the long-axis in-plane with short-axis out-of-plane approaches were included. Review Manager software version 5.4, STATA version 14.2, and trial sequential analysis (TSA) version 0.9.5.10 Beta were used for statistical analysis. Risk of bias and methodological quality of all studies included in this review were assessed according to the Cochrane Collaboration tool for the risk of bias. Subgroup analyses and meta-regression were performed to explore sources of heterogeneity.ResultsThe rate of cannula insertion success on the first attempt was similar between the short-axis out-of-plane and long-axis in-plane approaches (RR = 1.03; 95% CI: 0.83 to 1.28; P = 0.79; I2 = 83.0%). No significant differences were observed in total time to successful cannulation between the two approaches (MD = –3.9; 95% CI:-18.30 to 10.49; P = 0.6; I2 = 97%). However, the required information size for the success rate of the first attempt and total time to successful cannulation was not reached.ConclusionIt remains inconclusive whether short-axis out-of-plane is a better choice for radial arterial cannulation than the long-axis in-plane approach. Inexperienced operators may need more attempts and longer ultrasound location time with the short-axis out-of-plane technique.Systematic review registration[https://www.crd.york.ac.uk/prospero/], identifier [CRD42021236098]

    The Changes in Maternal Mortality in 1000 Counties in Mid-Western China by a Government-Initiated Intervention

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    BACKGROUND: Since 2000, the Chinese government has implemented an intervention program to reduce maternal mortality and eliminate neonatal tetanus in accordance with the Millennium Development Goals 5. To assess the effectiveness of this intervention program, we analyzed the level, trend and reasons defining the maternal mortality ratio (MMR) in the 1,000 priority counties before and after implementation of the intervention between 1999 and 2007. METHODOLOGY/PRINCIPAL FINDINGS: The data was obtained from the National Maternal and Child Health Routine Reporting System. The intervention included providing basic and emergency obstetric equipment and supplies to local medical hospitals, and also included providing professional training to local obstetric doctors, development of obstetric emergency centers and "green channel" express referral networks, reducing or waiving the cost of hospital delivery, and conducting community health education. Based on the initiation time of the intervention and the level of poverty, 1,000 counties, containing a total population of 300 million, were categorized into three groups. MMR significantly decreased by about 50%, with an average reduction rate of 9.24%, 16.06%, and 18.61% per year in the three county groups, respectively. The hospital delivery rate significantly increased. Obstetric hemorrhage was the leading cause of maternal deaths and significantly declined, with an average decrease in the MMR of 11.25%, 18.03%, and 24.90% per year, respectively. The magnitude of the MMR, the average reduction rate of the MMR, and the occurrence of the leading causes of death were closely associated with the percentage of poverty. CONCLUSIONS/SIGNIFICANCE: The intervention program implemented by the Chinese government has significantly reduced the MMR in mid-western China, suggesting that well-targeted interventions could be an efficient strategy to reducing MMR in resource-poor areas. Reduction of the MMR not only depends on conducting proven interventions, but also relies on economic development in rural areas with a high burden of maternal death

    Polysaccharides from the root of Angelica sinensis promotes hematopoiesis and thrombopoiesis through the PI3K/AKT pathway

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    <p>Abstract</p> <p>Background</p> <p>Dozens of Traditional Chinese Medicine (TCM) formulas have been used for promotion of "blood production" for centuries, and we are interested in developing novel thrombopoietic medicines from these TCMs. Our previous studies have demonstrated the hematopoietic effects of DangGui BuXue Tong (DBT), a formula composed of <it>Radix Angelicae Sinensis </it>and <it>Radix Astragali </it>in animal and cellular models. As a step further to identify and characterize the active chemical components of DBT, we tested the hematopoietic and particularly, thrombopoietic effects of polysaccharide-enriched fractions from the root of <it>Radix Angelicae Sinensis </it>(APS) in this study.</p> <p>Methods</p> <p>A myelosuppression mouse model was treated with APS (10 mg/kg/day). Peripheral blood cells from APS, thrombopoietin and vehicle-treated samples were then counted at different time-points. Using the colony-forming unit (CFU) assays, we determined the effects of APS on the proliferation and differentiation of hematopoietic stem/progenitor cells and megakaryocytic lineages. Using a megakaryocytic cell line M-07e as model, we analyzed the cellular apoptosis progression with and without APS treatment by Annexin V, Mitochondrial Membrane Potential and Caspase 3 assays. Last, the anti-apoptotic effect of APS on cells treated with Ly294002, a Phosphatidylinositol 3-Kinse inhibitor (PI3K) was also tested.</p> <p>Results</p> <p>In animal models, APS significantly enhanced not only the recovery of platelets, other blood cells and their progenitor cells, but also the formation of Colony Forming Unit (CFU). In M-07e cells, we observed the anti-apoptotic effect of APS. Treatment by Ly294002 alone increased the percentage of cells undergoing apoptosis. However, addition of APS to Ly294002-treated cells significantly reduced the percentage of cells undergoing apoptosis.</p> <p>Conclusions</p> <p>APS promotes hematopoiesis and thrombopoiesis in the mouse model. This effect likely resulted from the anti-apoptosis activity of APS and is likely to involve the PI3K/AKT pathway.</p
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