A systematic approach has been developed to estimate the relationship between the permeability and connectivity of two‐dimensional fracture networks, in which the network connectivity is evaluated ...with the concept of geological entropy as informative index of spatial disorder. The geological entropy is quantified by the entropic scale, a metric developed by Bianchi and Pedretti (2018), which is here applied to integrate multiple properties of two‐dimensional fracture networks, including aperture, spacing, length, orientation. Through the comparisons among several existing connectivity indicators including the entropic scale in an illustrative example, only the entropic scale is positively correlated with the permeability concerning aperture and can be successfully used to quantify the network connectivity. In order to understand connectivity characteristics dependence of the permeability, a computational method combining fracture network generation and steady‐state flow simulation is developed. Based on the results of detailed numerical simulations considering hydraulic behavior and connectivity characteristic in various fracture networks, the entropic scale and permeability are simultaneously inversely proportional to length and proportional to spacing with the same global entropy, but exhibit weak dependence on the orientation variation. A simple closed‐form empirical expression in terms of quadratic polynomial model between the permeability and entropic scale is proposed. The results indicated that geological entropy is valid and appropriate to quantify the connectivity and predict the permeability of two‐dimensional fracture networks.
Key Points
The entropic scale as informative index of spatial disorder of fracture networks is applied
The relationships between permeability, geological entropy, and structure of fracture networks are presented
An empirical quadratic polynomial model between the permeability and entropic scale is developed
•Geological-entropy-based hydraulic properties of DFN are investigated.•A unified relation between anisotropic permeability and entropy index is proposed.•There is a power-law relationship of ...hydraulic REV size versus entropy scale.
To investigate the intrinsic association between geometrical properties and permeability of anisotropic fractured media, a methodology of geological entropy is applied to anisotropic fracture networks for the evaluation of seepage fields. By integrating the synthetic effect of fracture geometrical parameters (e.g., trace length, spacing, dip angle, and aperture), the global connectivity of fracture networks is quantified by the entropy scale (Hs), while the directional entropy scale (Hs,α) is used to characterize the local geometrical anisotropy in arbitrary orientations. A series of hydraulic representative elementary volumes (REVs) of fracture patterns with various geometrical properties are acquired based on continuum analysis. The permeability in the continuum scale is obtained from steady-state flow simulations. Sensitivity analyses are performed to understand the geometrical dependence of permeability parameters regarding entropy indices. It is found that a systematic increase in trace length, spacing, and dip angle is correlated with an increase, decrease, and equilibrium in entropy, respectively, which corresponds to a change in hydraulic REV sizes that can be expressed as a power-law function related to the Hs. Moreover, Hs,α can well explain the permeability anisotropy resulting from the spatial order of fracture networks, and a unified mathematical relationship for the effective permeability coefficients in arbitrary orientations versus the Hs,α is proposed, independent of variations in fracture patterns and scales. The results indicate that geological entropy, related to the geometrical properties and spatial distribution of fractures, is appropriate to characterize the permeability of anisotropic systems.
With an extension of the geological entropy concept in porous media, the approach called directional entrogram is applied to link hydraulic behavior to the anisotropy of the 3D fracture networks. A ...metric called directional entropic scale is used to measure the anisotropy of spatial order in different directions. Compared with the traditional connectivity indexes based on the statistics of fracture geometry, the directional entropic scale is capable to quantify the anisotropy of connectivity and hydraulic conductivity in heterogeneous 3D fracture networks. According to the numerical analysis of directional entrogram and fluid flow in a number of the 3D fracture networks, the hydraulic conductivities and entropic scales in different directions both increase with spatial order (i.e., trace length decreasing and spacing increasing) and are independent of the dip angle. As a result, the nonlinear correlation between the hydraulic conductivities and entropic scales from different directions can be unified as quadratic polynomial function, which can shed light on the anisotropic effect of spatial order and global entropy on the heterogeneous hydraulic behaviors.
Glypican-3 (GPC3) has been widely recognized in the progression of liver tumors for several years. The relationship between overexpression of GPC3 and the poorer prognosis of patients with ...hepatocellular carcinoma (HCC) was performed by 2 meta-analyses. However, there were also some latest literatures that indicated different conclusions distinctly. It is necessary for us to carry out a meta-analysis by adding the latest data from current studies to explore the correlation between GPC3 and prognostic value in HCC.
We conducted a meta-analysis including a total of 14 studies to assess the potential prognostic significance of GPC3 expression for overall survival (OS) and disease-free survival (DFS). The expression of GPC3 was assessed by immunohistochemistry.
Fourteen studies with 2364 patients were incorporated in the meta-analysis. The combined hazard ratios (HRs) revealed that the overexpression of GPC3 could forecast a poor OS n = 2233 in 12 studies, HR = 1.40, 95% confidence interval (95% CI): 1.07-1.85, Z = 2.42, P = .02 and DFS (n = 1308 in 10 studies, HR = 1.61, 95% CI: 1.13-2.30, Z = 2.63, P = .008) in HCC patients. Subgroup treated by hepatectomy indicated that the pooled HR of OS was 1.43 (95% CI: 1.01-2.01, P = .04) and the combined HR of DFS was 1.59 (95% CI: 1.09-2.31, P = .02). The pooled odds ratios (ORs) showed that high GPC3 expression was also extensively associated with worse tumor differentiation, later tumor stage, presence of vascular invasion, and hepatitis B virus (HBV) infection. Subgroup analyses for GPC3 on HCC OS based on the studies categorized by regions, follow-up period, and sample size were also conducted.
The meta-analysis indicated that overexpression of GPC3 was significantly associated with poor prognosis in patients with HCC.
Phosphodiesterase 4D interacting protein (PDE4DIP) is a centrosome/Golgi protein associated with cyclic nucleotide phosphodiesterases. PDE4DIP is commonly mutated in human cancers, and its alteration ...in mice leads to a predisposition to intestinal cancer. However, the biological function of PDE4DIP in human cancer remains obscure. Here, we report for the first time the oncogenic role of PDE4DIP in colorectal cancer (CRC) growth and adaptive MEK inhibitor (MEKi) resistance. We show that the expression of PDE4DIP is upregulated in CRC tissues and associated with the clinical characteristics and poor prognosis of CRC patients. Knockdown of PDE4DIP impairs the growth of KRAS-mutant CRC cells by inhibiting the core RAS signaling pathway. PDE4DIP plays an essential role in the full activation of oncogenic RAS/ERK signaling by suppressing the expression of the RAS GTPase-activating protein (RasGAP) neurofibromin (NF1). Mechanistically, PDE4DIP promotes the recruitment of PLCγ/PKCε to the Golgi apparatus, leading to constitutive activation of PKCε, which triggers the degradation of NF1. Upregulation of PDE4DIP results in adaptive MEKi resistance in KRAS-mutant CRC by reactivating the RAS/ERK pathway. Our work reveals a novel functional link between PDE4DIP and NF1/RAS signal transduction and suggests that targeting PDE4DIP is a promising therapeutic strategy for KRAS-mutant CRC.
Strategy management alludes to the organizational and environmental factors that shape firms’ propensities to make research and development (R&D) investments. We complement this literature by ...building on vicarious learning to explain how a firm determines its own R&D investment level based on the R&D investment patterns of partners and competitors. Using panel data on firms publicly traded in China, we show an inverted U-shaped relationship between a firm’s R&D investment pattern and the R&D investment patterns of its partners and competitors. Convergence is driven by imitation and legitimation while divergence is explained by risk perception. We conclude that competitors represent a more valuable reference than partners. Our findings advance research on vicarious learning and the antecedents of R&D investments, underscoring the role of interdependence in influencing firms’ R&D investment decisions.
•Achieving CoFe alloy & Co + Fe2C in Co-Fe bimetallic catalysts by a strategic precursor addition.•Ensuring consistent metal size and support properties for each catalyst.•Investigating the ...performance mechanism of three active phases in FTS.•Leveraging Co-Fe interaction in CoFe alloy to optimize CO/H2 adsorption behaviors.•Enhancing FTS performance through increased strongly adsorbed CO and improved CO/H2 ratio.
In the realm of Fischer-Tropsch synthesis (FTS), the escalating cost of cobalt has spurred interest in Co-Fe bimetallic catalysts as substitutes for monometallic Co catalysts. Unfortunately, it is difficult to clarify specific functions and interactions of the two phases, as investigating catalysts in a unified dimension of both metal and support is still a challenge. Herein, we realize precise control over synthesizing nitrogen-doped carbon materials supported bimetallic catalysts containing CoFe alloy and Co + Fe2C dual active phases. The catalysts are comprehensively characterized to address the above problem by excluding the influence of metal sizes and support properties. Our findings reveal that compared to metallic Co alone and Co + Fe2C dual active phases, the Co-Fe interaction in CoFe alloy with electron transfer from Fe to Co optimizes reactant adsorption behaviors through achieving a larger number of strongly adsorbed CO per active site to increase the density of C* adsorbates and a higher surface CO/H2 ratio to inhibit the hydrogenation of CHx* intermediates for chain termination, as well as an appropriate ability for CO adsorption/ dissociation. These advantages collectively enhance both CO activation and C-C coupling, and consequently, the CoFe/NC (CoFe alloy) catalyst exhibits the superior catalytic performance in the cobalt space–time yield in C5+ products (3011.2 gC5+ kgCo−1h−1), which surpasses the Co/NC (monometallic Co) and Co + Fe/NC (Co + Fe2C dual active phases) by 2.2 times and 2.4 times, respectively. This study serves as a promising route for the development of efficient and low-cost bimetallic catalysts through the strategic arrangement of multiple active phases for various reactions.
Objective
This study aimed to elucidate the underlying mechanisms of ameloblastoma (AM) through integrated bioinformatics analysis.
Methods
We downloaded two microarrays of AMs from the GEO database ...and identified differentially expressed genes (DEGs) by integrated bioinformatics analysis. The enrichment analysis of DEGs was conducted to characterize GO and KEGG pathways. Protein‐protein interaction (PPI) network and hub genes were screened via STRING and Cytoscape. CIBERSORT algorithm was utilized to analyze immune infiltration in AMs. We also verified the diagnostic and therapeutic value of hub genes.
Results
Overall, 776 DEGs were identified in AMs through bioinformatics analysis. The function enrichment analysis shed light on pathways involved in AMs. Subsequently, we screened six hub genes via PPI network. Furthermore, we evaluated immune infiltration in AMs and found that macrophages may be participating in the progression of AMs. The upregulated expression of FN1 was related to the macrophages M2 polarization. Finally, ROC analysis indicated that six hub genes had high diagnostic value for AMs and 11 drugs interacted with upregulated hub genes were identified by screening the DGIdb database.
Conclusion
This study revealed the underlying mechanisms of pathogenesis and biological behavior of AMs and provided candidate targets for the diagnosis and treatment of AMs.
Experimental studies were carried out to explore the effect of zeolite topology on NOx purification and soot oxidation in ammonia selective catalytic reduction coated diesel particulate filter (SCRF) ...catalysts. The catalytic activity of Cu-exchanged zeolites Cu/SSZ-13 (CHA topology), Cu/ZSM-5 (MFI), and Cu/BEA(BEA) was evaluated in the NH3–SCRF. Experiments with XRD and ICP-SFMS demonstrated that the three types of samples retained their typical structural peaks after Cu modification, and the similar ratios of Cu/Al and Si/Al ensure that the primary cause of different catalytic performances was caused by different framework structures. As determined by laboratory experiments with synthetic gas, Cu/SSZ-13 exhibited an extended activity window and a higher deNOx efficiency at NO2/NOx below 0.5. In addition, Cu/ZSM-5 consistently exhibited superior CO2 selectivity in soot-loading experiments, regardless of the NO2 concentration. When loaded with soot, Cu/BEA exhibited exceptional deNOx performance at NO2/NOx = 0.5. NH3 was observed to have a negative effect on soot oxidation by NO2, while the consumption of NO2 by soot oxidation contributed to the NO2–SCR reaction being aided. Influenced by different zeolite structural features, the degree of diffusion of copper in the zeolite as well as the replacement sites are different, thus forming different ratios of copper species. For instance, the presence of Z2Cu sites, which can adsorb more NH3 molecules than ZCuOH sites as indicated by the in situ DRIFTS results, and the presence of Cu+ with stronger redox properties compared to Cu2+, can be influenced by these structural characteristics. Additionally, soot particles have the ability to act as adsorption sites for the NH3–SCR reaction.
The noncircular synchronous belt drive mechanism has demonstrated certain achievements and has been used in special fields. Research regarding noncircular synchronous belt drive mechanisms has ...focused on optimization design and kinematic analysis in China, whereas two pulley noncircular synchronous belt transmissions have been developed overseas. However, owing to the noncircular characteristics of the belt pulley, the real-time variation in the belt length slack during the transmission of the noncircular synchronous belt is significant, resulting in high probabilities of skipping and vibration. In this study, a noncircular tensioning pulley is added to create a stable three-pulley noncircular synchronous belt driving mechanism and a good synchronous belt tensioning, with no skipping; hence, the non-uniform output characteristic of the driven pulley is consistent with the theoretical value. In the circular noncircular noncircular three-pulley noncircular synchronous belt mechanism, the pitch curve of the driving synchronous belt pulley is circular, whereas those of the driven synchronous belt and tensioning pulleys are noncircular. To minimize the slack of the belt length of the synchronous belt and the constraint of the concavity and circumference of the tensioning pulley, an automatic optimization model of the tensioning pulley pitch curve is established. The motion simulation, analysis, and optimization code for a three-belt-pulley noncircular synchronous belt drive mechanism is written, and the variation in belt length slack under different speed ratios is analyzed based on several examples. The testbed for a circular–noncircular–noncircular three-pulley noncircular synchronous belt transmission mechanism is developed. The test shows that the three-pulley noncircular synchronous belt drives well. This study proposes an automatic optimization algorithm for the tensioning pulley pitch curve of a noncircular synchronous belt transmission mechanism; it yields a stable transmission of the noncircular synchronous belt transmission mechanism as well as non-uniform output characteristics.
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