14 research outputs found

    Conservation of copy number profiles during engraftment and passaging of patient-derived cancer xenografts

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    Patient-derived xenografts (PDXs) are resected human tumors engrafted into mice for preclinical studies and therapeutic testing. It has been proposed that the mouse host affects tumor evolution during PDX engraftment and propagation, affecting the accuracy of PDX modeling of human cancer. Here, we exhaustively analyze copy number alterations (CNAs) in 1,451 PDX and matched patient tumor (PT) samples from 509 PDX models. CNA inferences based on DNA sequencing and microarray data displayed substantially higher resolution and dynamic range than gene expression-based inferences, and they also showed strong CNA conservation from PTs through late-passage PDXs. CNA recurrence analysis of 130 colorectal and breast PT/PDX-early/PDX-late trios confirmed high-resolution CNA retention. We observed no significant enrichment of cancer-related genes in PDX-specific CNAs across models. Moreover, CNA differences between patient and PDX tumors were comparable to variations in multiregion samples within patients. Our study demonstrates the lack of systematic copy number evolution driven by the PDX mouse host.</p

    Research on the Optimized Operation of Hybrid Wind and Battery Energy Storage System Based on Peak-Valley Electricity Price

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    The combined operation of hybrid wind power and a battery energy storage system can be used to convert cheap valley energy to expensive peak energy, thus improving the economic benefits of wind farms. Considering the peak–valley electricity price, an optimization model of the economic benefits of a combined wind–storage system was developed. A charging/discharging strategy of the battery storage system was proposed to maximize the economic benefits of the combined wind–storage system based on the forecast wind power. The maximal economic benefits were obtained based on scenario analysis, taking into account the wind-power forecast error, and costs associated with the loss of battery life, battery operation, and maintenance. Case simulation results highlight the effectiveness of the proposed model. The results show that the hybrid wind–storage system is not only able to convert cheap electricity in the valley period into expensive electricity in the peak period, thus resulting in higher economic benefits, but can also balance the deviation between actual output and plans for the wind power generator to decrease the loss penalty. The analyzed examples show that, following an increase in the deviation of the forecast wind power, the profit of the combined wind–storage system can increase by up to 45% using the charging/discharging strategy, compared with a wind farm that does not utilize energy storage. In addition, the profit of the combined wind–storage system can increase by up to 16% compared with separate systems, following an increase in the deviation penalty deviation coefficient

    Residual Stress and Distortion Prediction for Laser Directed Energy Deposition Based on Cyclic Heat Transfer Model

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    Predicting the residual stress and distortion caused by inhomogeneous temperature fields in the laser directed energy deposition (LDED) process is a challenging task. This study proposes a novel thermodynamic coupling simulation method based on the cyclic heat transfer model to accurately predict temperature, stress, and distortion evolution during the deposition process. The model effectively calculates the layer-by-layer superposition of thermal effects and cyclic accumulation of thermal stress during the deposition process, leading to improved prediction accuracy for temperature, residual stress, and distortion. Initially, the heat source model, the cyclic heat transfer model, and the thermoelastic matrix are established. The thermoelastic constitutive equation and the equilibrium differential equation are formulated to capture the actual process characteristics of the LDED accurately in order to achieve the thermodynamic coupling solution. Then, numerical simulations are performed on a typical model specimen, with simulation parameters consistent with the actual deposition parameters. Finally, the predicted results are validated through actual deposition experiments, and the temperature, stress, and distortion history are analyzed. The results demonstrate that the cyclic thermodynamic coupling model proposed in this study can effectively predict the deposited components&#x2019; temperature, residual stress, and distortion evolution. This study establishes a crucial foundation for achieving precision and performance control in the deposition process and reducing residual stress and distortion in the components

    Effectiveness and Efficiency of Externally Bonded CFRP Sheets for Shear Strengthening of RC Beam-Column Joints

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    To develop feasible carbon fiber reinforced polymer (CFRP) retrofit schemes for the shear strengthening of real three-dimensional reinforced concrete (RC) beam-column joints, a series of parameters in relation to the contributions of the CFRP sheets externally bonded to joint panels was numerically investigated in this study. The parameters include CFRP reinforcement ratio, CFRP layout, transverse beam-to-joint panel width ratio, transverse beam-to-joint panel height ratio, location of transverse beam, and number of transverse beams. Strengthening efficiency, a new dimensionless index, was introduced to evaluate the residual effect of a CFRP-strengthening system weakened by the presence of transverse beams in comparison with the increase in joint shear capacity in relation to the one-way counterpart. The results obtained from 44 nonlinear finite element models, which were calibrated against experimental observations, confirmed the effectiveness of the CFRP strengthening technique with regard to the relatively wide ranges of the parameters. The significant differences among the roles of the parameters were revealed, and the reasons behind the differences were analyzed. Furthermore, the shear mechanism of the CFRP-retrofitted joint panels was discussed with the proposed strut-and-tie model

    Rational Design of a Unique Ternary Structure for Highly Photocatalytic Nitrobenzene Reduction

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    The rational design and controllable synthesis of TiO<sub>2</sub> and noble metal composite photocatalysts represent an unprecedented challenge for developing the solar-driven reduction of nitrobenzene (NB) to aminobenzene (AB), owing to the recombination over the interface between the noble metals and TiO<sub>2</sub>, which is harmful to the conversion efficiency of NB to AB. Here, we design a unique ternary structure (the high separation of TiO<sub>2</sub> and Pt nanoparticles on the surface of reduced graphene oxide (RGO)) through the sol–gel and microwave-assisted strategies. The substrate of RGO can be used as an “electric wire” to effectively transfer the photogenerated electrons from the isolated TiO<sub>2</sub> nanocrystals to the isolated Pt nanoparticles, which greatly decreases the interface recombination between TiO<sub>2</sub> and Pt and further improves the conversion efficiency of NB to AB under the solar light irradiation. We anticipate our research provides a new way to overcome the interface recombination on the binary photocatalysts in the photocatalytic reaction

    BTF3 sustains cancer stem-like phenotype of prostate cancer via stabilization of BMI1

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    Abstract Background Cancer stem-like traits contribute to prostate cancer (PCa) progression and metastasis. Deciphering the novel molecular mechanisms underlying stem-like traits may provide important insight for developing novel therapeutics. Methods Immunohistochemistry and immunofluorescence assays in prostatic tissues; gain- and loss-of-function analyses using ectopic overexpression and shRNAs in PCa cell lines; measurements of tumorigenic and stemness properties, and transcription in vitro and in vivo; transcriptional analysis in public databases. Results We identified that overexpression of BTF3 in PCa tissues and BTF3 expression highly correlates to stem-like traits. Cancer stem-like characteristics in PCa including self-renewal and metastatic potential were impaired by BTF3 loss and promoted by BTF3 overexpression. Mechanistically, BTF3 could stabilize BMI1, which is a crucial regulator of prostate stem cell self-renewal. More importantly, our data revealed that BTF3 is highly predictive of poor prognosis and may help in risk stratification of PCa patients. Conclusions BTF3 promotes PCa progression though modeling stem-like traits in PCa. BTF3 represents a stratification marker in PCa progression and outcomes
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