A foundation of the modern technology that uses single-crystal silicon has been the growth of high- quality single-crystal Si ingots with diameters up to 12 inches or larger. For many applications of ...graphene, large-area high-quality （ideally of single-crystal） material will be enabling. Since the first growth on copper foil a decade ago, inch-sized single-crystal graphene has been achieved. We present here the growth, in 20 min, of a graphene film of （5 × 50） cm^2 dimension with 〉99% ultra-highly oriented grains. This growth was achieved by： （1） synthesis of metre-sized single-crystal Cu（111） foil as substrate; （2） epitaxial growth of graphene islands on the Cu（1 1 1） surface; （3） seamless merging of such graphene islands into a graphene film with high single crystallinity and （4） the ultrafast growth of graphene film. These achievements were realized by a temperature-gradient-driven annealing technique to produce single-crystal Cu（1 1 1） from industrial polycrystalline Cu foil and the marvellous effects of a continuous oxygen supply from an adjacent oxide. The as-synthesized graphene film, with very few misoriented grains （if any）, has a mobility up to ～23,000 cm^2 V^-1 s^-1 at 4 K and room temperature sheet resistance of ～230 Ω/□. It is very likely that this approach can be scaled up to achieve exceptionally large and high-quality graphene films with single crystallinity, and thus realize various industrial-level applications at a low cost.
Microglia/macrophages (M/Ms) with multiple functions derived from distinct activation states are key surveillants maintaining brain homeostasis. However, their activation status and role during the ...brain metastasis of malignant tumors have been poorly characterized.
Heterozygous CX3CR1-GFP transgenic mice were used to visualize the dynamic changes of M/Ms during the development of experimental brain metastasis through long-term intravital imaging equipped with redesigned bilateral cranial windows. The occurrence of experimental brain metastasis was evaluated after M/Ms were depleted with PLX3397, a CSF-1R inhibitor. The possible mediators of M/Ms in facilitating the brain metastasis were determined using reverse transcription-PCR, immunofluorescence, correlational analysis, and MMP inhibition.
Here, we showed that M/Ms were persistently activated and facilitated the formation of melanoma brain metastasis in vivo. We observed that M/Ms gradually and massively accumulated in the metastasis, with a 2.89-fold increase. To precisely depict the dynamic changes in the activation state of M/Ms, we defined the branching parameter to quantify their morphological alterations. The quantitative data showed that the extent of activation of M/Ms in metastatic foci was enhanced, with a 2.27-fold increase from day 1 to day 21. Along with the activation, the M/Ms increased their moving velocity (4.15-fold) and established a rapid, confined, and discontinuous motility behavior. The occurrence of melanoma brain metastasis was significantly hindered under M/M elimination, indicating the key role of M/Ms in the experimental brain metastasis. Interestingly, we found that M/Ms highly expressed matrix metalloproteinase 3 (MMP3), which were strongly correlated with M/M activation and the decrease of tight junction protein zonula occludens-1 (ZO-1). An MMP inhibitor moderately decreased the occurrence of melanoma brain metastasis, suggesting that MMP3 secreted by M/Ms may facilitate melanoma cell growth.
Our results indicated that the activated M/Ms were essential in the development of melanoma brain metastasis, suggesting that M/Ms are a potential therapeutic target for tumor brain metastasis.
The strength reduction method (SRM) is becoming more and more popular in the stability analysis of slopes. Nevertheless, the criterion for slope failure associated with SRM is controversial, and ...divergence exists while approaching to the limit equilibrium state of slopes. In this study, the slip body is discretized with constant boundary elements. Since at least one element on the slip surface, referred to as the critical element, should keep still till the slope reaches the limit equilibrium state, the critical element is forced to be fixed throughout while other elements on the slip surface are specified to be contact elements during the strength reduction. In this way, convergence is always assured in the open-close iteration of contact between the slip body and the slip bed, no matter how much the strength of the slip surface is reduced. The limit equilibrium state is defined to be the moment at which the strength redundancy of the critical element vanishes. The method of bisection is applied to find out the factor of safety (FOS). The proposed method is applied to those benchmark examples and the comparison is made with the limit equilibrium methods (LEM).
A series of bismuth sulfide (Bi2S3) nanorods and amine-functionalized Ti-based metal–organic framework heterojunctions denoted by Bi2S3@NH2-MIL-125(Ti) were constructed and explored as bifunctional ...photocatalysts for Cr(vi) reduction and rhodamine B (RhB) degradation under visible light illumination. Compared with the individual NH2-MIL-125(Ti) and Bi2S3, the as-synthesized Bi2S3@NH2-MIL-125(Ti) photocatalyst exhibited an enhanced photocatalytic activity toward Cr(vi) and RhB owning to the synergetic effect between Bi2S3 and NH2-MIL-125(Ti). Moreover, the Bi2S3@NH2-MIL-125(Ti) heterojunctions showed increased Cr(vi) removal efficiency by adding RhB in the system. The photocatalytic mechanism was proposed based on the analysis of different scavenger for active species and electron spin resonance spectrometry. The introduction of Bi2S3 into NH2-MIL-125(Ti) can extend the light adsorption and improve the transfer and separation of photogenerated charge carriers through the Bi2S3@NH2-MIL-125(Ti) heterojunction with unique band gap structure. The synthesized Bi2S3@NH2-MIL-125(Ti) photocatalyst also exhibited good reusability and stability.
With the development of hybrid imaging scanners, micro-CT is widely used in locating abnormalities, studying drug metabolism, and providing structural priors to aid image reconstruction in functional ...imaging. Due to the low contrast of soft tissues, segmentation of soft tissue organs from mouse micro-CT images is a challenging problem. In this paper, we propose a mouse segmentation scheme based on dynamic contrast enhanced micro-CT images. With a homemade fast scanning micro-CT scanner, dynamic contrast enhanced images were acquired before and after injection of non-ionic iodinated contrast agents (iohexol). Then the feature vector of each voxel was extracted from the signal intensities at different time points. Based on these features, the heart, liver, spleen, lung, and kidney could be classified into different categories and extracted from separate categories by morphological processing. The bone structure was segmented using a thresholding method. Our method was validated on seven BALB/c mice using two different classifiers: a support vector machine classifier with a radial basis function kernel and a random forest classifier. The results were compared to manual segmentation, and the performance was assessed using the Dice similarity coefficient, false positive ratio, and false negative ratio. The results showed high accuracy with the Dice similarity coefficient ranging from 0.709 ± 0.078 for the spleen to 0.929 ± 0.006 for the kidney.
Transcriptional Co-Activator with PDZ-Binding Motif (TAZ, also known as WWTR1) is a downstream effector of the Hippo pathway, involved in the regulation of organ regeneration and cell differentiation ...in processes such as development and regeneration. TAZ has been shown to play a tumor-promoting role in various cancers. Currently, many studies focus on the role of TAZ in the process of mitophagy. However, the molecular mechanism and biological function of TAZ in renal clear cell carcinoma (KIRC) are still unclear. Therefore, we systematically analyzed the mRNA expression profile and clinical data of KIRC in The Cancer Genome Atlas (TCGA) dataset. We found that TAZ expression was significantly upregulated in KIRC compared with normal kidney tissue and was closely associated with poor prognosis of patients. Combined with the joint analysis of 36 mitophagy genes, it was found that TAZ was significantly negatively correlated with the positive regulators of mitophagy. Finally, our results confirmed that high expression of TAZ in KIRC inhibits mitophagy and promotes KIRC cell proliferation. In conclusion, our findings reveal the important role of TAZ in KIRC and have the potential to be a new target for KIRC therapy.
This research presents a simulation of hydraulic fracturing process in a naturally fractured reservoir based on a discrete fracture network (DFN) model coupling different kinds of pre-existing ...discontinuities. Natural fractures and bedding planes obtained from outcrops and downhole camera in the Ordos Basin of China are used to build a three-dimensional DFN model. The propagation of hydraulic fractures in the layered and naturally-fractured reservoir, and the complex interactions between hydraulic fractures, natural fractures and bedding planes are simulated using the displacement discontinuity method. The results show that strong interactions between hydraulic fractures and pre-existing discontinuities occur during fluid injection, causing complex fracture geometry. When the injection rate is 0.01 m3/min, only one major hydraulic fracture is induced, and crack growth along bedding interface does not occur since the fluid pressure is not high enough. With increasing injection rate (0.1 m3/min and 1.0 m3/min), natural fracture and bedding planes are activated, inducing multiple major hydraulic fractures and reticulated fractures. For each injection scheme, fracture geometry in the horizontal and vertical directions becomes more complex with the injection of fracturing fluid. However, fracture complexity in the horizontal direction is smaller than that in the vertical direction when the injection rate varies from 0.01 m3/min to 1.0 m3/min. Besides, the results show that injection rate has a strong positive influence on the increment of fracture complexity.
•A DFN model coupling different kinds of geological discontinuities is built.•Simulation of hydraulic fracturing in a fractured reservoir is conducted using DDM.•Influence of natural fractures and bedding planes on hydraulic fracturing is studied.
The hydrogen evolution reaction (HER) is a crucial step in electrochemical water splitting that demands an efficient, cheap, and stable catalyst to succeed in practical applications. Two-dimensional ...(2D) layered molybdenum disulfide (MoS2), known to contain active edge sites and a chemically inert basal plane, has provided great promise as a non-precious alternative to platinum-based catalysts for electrochemical hydrogen production from water. Here, we directly synthesize fractal-shaped single-layer MoS2 with large tensile strain on fused silica. The as-synthesized MoS2 with a large amount of exposed edge sites is superior to the triangle-shaped MoS2 grown on SiO2 for catalyzing HER. By controlling the MoS2 grain size and coverage, etc., we identify the active sites of the MoS2. Electrocatalytic activity of the MoS2 for the HER correlates linearly with the number of edge sites with an enhanced activity of ~ 2.74 × 10−7 μA μm−1, due to the increased supplying of electrons to the active edge sites caused by the large tensile strain. The optimal HER electrocatalyst of the fractal-shaped single-layer MoS2, which has an edge-to-substrate ratio of about 0.33 µm−1, exhibits superior HER catalytic activities such as a low overpotential of 185 mV at a current density of 10 mA cm−2, a Tafel slope of 45 mV/dec, an exchange current density of 50.9 μA cm−2, and long-term stability. The present study provides new ways to design 2D HER electrocatalysts, including controlling the geometry, strain, and modulating the electrical conductivity.
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•Synthesis of fractal-shaped single-layer MoS2 with large tensile strain on fused silica.•The fractal-shaped MoS2 exhibits a superior electrochemical activity for hydrogen evolution reaction (HER).•Electrocatalytic activity of the MoS2 for the HER correlates linearly with the number of edge sites with an enhanced activity of ~ 2.74 × 10−7 μA μm−1.•The study provides new ways to design 2D HER electrocatalysts, including controlling the geometry, strain, and modulating the electrical conductivity.
Antimony is one of the heavier pnictogens and is widely found in human food chains, water sources, and as an air pollutant. Recent years have seen steadily increasing concentrations of antimony in ...the ecological environment; critically, several studies have indicated that antimony might pose a tumorigenic risk factor in several cancers. Therefore, antimony toxicity has attracted increasing research attention, with the molecular mechanisms underlying suspected antimony-mediated tumor transformation of greatest interest. Our results showed that the serum concentration of antimony was higher in bladder tumor patients relative to levels in non-tumor patients. Moreover, that such high antimony serum concentration were closely associated with poorer outcome in bladder tumor patients. Additionally, we demonstrated that the presence of antimony promoted both in vitro and in vivo bladder tumor cell growth. Our results also indicated that low-dose antimony resulted in significantly decreased mitochondrial membrane potential, mitochondrial respiratory enzyme complex I/II/III/IV activity, ATP/ADP ratio, and ATP concentration relative to the control group. These findings suggested that antimony caused mitochondrial damage. Finally, we found that low-dose antimony(0.8uM) inhibited mitophagy by deregulating expression of PINK1, Parkin, and p(ser65)-Parkin, and activation of PINK1-Parkin pathway by CCCP could inhibit antimony-induced tumor cell growth. Collectively, this inhibited the proliferation of bladder tumor cells. Overall, our study suggested that antimony promoted bladder tumor cell growth by inhibiting PINK1-Parkin-mediated mitophagy. These findings highlight the therapeutic potential in targeting molecules within this antimony induced-PINK1/Parkin signaling pathway and may offer a new approach for the treatment of bladder cancer.
•Low dose of antimony exposure could promote bladder cancer cell proliferation and migration.•Antimony could damage mitochondria through ROS-dependent oxidative stress pathways.•Antimony could inhibit the level of mitophagy by directly decreasing the PINK1/Parkin pathway.•Antimony could promote bladder tumor cell growth by inhibiting PINK1-Parkin-mediated mitophagy.
Simultaneous Localization and Mapping (SLAM), as one of the core technologies in intelligent robotics, has gained substantial attention in recent years. Addressing the limitations of SLAM systems in ...dynamic environments, this research proposes a system specifically designed for plant factory transportation environments, named GY-SLAM. GY-SLAM incorporates a lightweight target detection network, GY, based on YOLOv5, which utilizes GhostNet as the backbone network. This integration is further enhanced with CoordConv coordinate convolution, CARAFE up-sampling operators, and the SE attention mechanism, leading to simultaneous improvements in detection accuracy and model complexity reduction. While mAP@0.5 increased by 0.514% to 95.364, the model simultaneously reduced the number of parameters by 43.976%, computational cost by 46.488%, and model size by 41.752%. Additionally, the system constructs pure static octree maps and grid maps. Tests conducted on the TUM dataset and a proprietary dataset demonstrate that GY-SLAM significantly outperforms ORB-SLAM3 in dynamic scenarios in terms of system localization accuracy and robustness. It shows a remarkable 92.59% improvement in RMSE for Absolute Trajectory Error (ATE), along with a 93.11% improvement in RMSE for the translational drift of Relative Pose Error (RPE) and a 92.89% improvement in RMSE for the rotational drift of RPE. Compared to YOLOv5s, the GY model brings a 41.5944% improvement in detection speed and a 17.7975% increase in SLAM operation speed to the system, indicating strong competitiveness and real-time capabilities. These results validate the effectiveness of GY-SLAM in dynamic environments and provide substantial support for the automation of logistics tasks by robots in specific contexts.
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