77 research outputs found

    Vertical stress and stability of interburden over an abandoned pillar working before upward mining: a case study

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    Upward mining of the residual coal seam over an abandoned pillar working is one of the effective measures to alleviate the contradiction between limited resources and increased consumption. Interburden stability over an abandoned pillar working plays a significant role in guaranteeing the safety of upward mining; however, it has not yet been extensively studied and understood. In this study, the vertical stress of the interburden over an abandoned pillar working was first investigated. The mechanical model of the interburden was established and the damage conditions were analysed. Then, the stability of the interburden over 38502 abandoned workings in Baijiazhuang coal mine was determined by mechanical analysis and field monitoring. The results show that: (i) Vertical stress of the interburden over abandoned mining zones is clearly lower than the initial stress, indicating the existence of a de-stressed effect. Moreover, vertical stress of the interburden over residual coal pillars is greater than the initial stress, which is the evidence of a stress 2 concentration effect. (ii) The interburden over an abandoned pillar working should be regarded as an elastic rectangular plate supported by generalized Kelvin bodies in mechanical modelling. (iii) The interburden over abandoned mining zones may experience two damage stages. In the first stage, initial plastic damage appears at the central region of interburden. In the second stage, the plastic damage evolves from the central point to the surrounding areas. (iv) The mechanical analysis and field monitoring both indicate the initial damage occurred at the central region over 38502 abandoned workings in Baijiazhuang coal mine before upward mining. Related rock control measures should be implemented in that region to guarantee the safe mining of the residual coal seam

    Gujin Dan is a Chinese medicine formulation that stimulates cell proliferation and differentiation by controlling multiple genes involved in MC3T3-E1 cells

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    Background: With the development of Traditional Chinese medicine (TCM) in recent years, the use of TCM in the treatment of osteoporosis has received much attention and research. Gujin Dan (GJD) is one of the representative Chinese medicine formulations that work synergistically with 19 herbs and has been used for decades to treat cervical spondylosis, lumbar disc herniation, osteoarthritis and osteoporosis. However, the exact molecular mechanism by which GJD is used to strengthen bones in the treatment of osteoporosis remains largely unknown. / Methods: In this study, an aqueous extract of GJD was prepared and its components were identified by high-performance liquid chromatography (HPLC). The effect of GJD aqueous extract on MC3T3-E1 cells was determined by Cell Counting Kit-8 (CCK-8) assay, alkaline phosphatase (ALP), and alizarin red S staining (ARS), combined with RNA sequencing (RNA-seq) and qRT-PCR. / Results: Our study showed that GJD significantly promoted the proliferation of MC3T3-E1 cells, as well as the synthesis and mineralisation of the extracellular matrix. GJD significantly increased the expression levels of genes that promote cell proliferation such as Adamts1, Mcam, Cyr61, Fos, Cebpd, Fosl2, Sirt1, Nipbl, Sema3c and Kcnq1ot1, up-regulated genes that inhibit apoptosis such as Gadd45a, Birc3, up-regulated genes that inhibit osteoclastogenesis such as Bcl6, Nfkbiz, Clcf1, Bcl3, Lgals3, Wisp1, Dusp1 and Fblim1, up-regulated genes that promote MC3T3-E1 cell differentiation such as Junb, Egr1, Klf10, Atf6, Malat1, Btg2, Sertad4, Zfyve16, Tet2, Creb5, Snai2, Fam46a, Calcrl and Pdzrn3. In addition, GJD mildly upregulated the expression levels of gene markers such as Atf4, Fn1, Usp7, Sox4, Col16a1, Spp1, Bmp1, Runx2, Bglap, Col12a1, and Alpl in osteoblasts. / Conclusions: Our results show that GJD promotes the differentiation and proliferation of MC3T3-E1 cells, inhibits osteoclast formation, and prevents osteoblast apoptosis. The present study significantly improves the current understanding of the molecular effects of GJD on MC3T3-E1 cells. This study also provides a new strategy for the further use of Chinese medicinal preparations against bone metabolism-related diseases

    Gazelle: A Low Latency Framework for Secure Neural Network Inference

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    The growing popularity of cloud-based machine learning raises a natural question about the privacy guarantees that can be provided in such a setting. Our work tackles this problem in the context where a client wishes to classify private images using a convolutional neural network (CNN) trained by a server. Our goal is to build efficient protocols whereby the client can acquire the classification result without revealing their input to the server, while guaranteeing the privacy of the server's neural network. To this end, we design Gazelle, a scalable and low-latency system for secure neural network inference, using an intricate combination of homomorphic encryption and traditional two-party computation techniques (such as garbled circuits). Gazelle makes three contributions. First, we design the Gazelle homomorphic encryption library which provides fast algorithms for basic homomorphic operations such as SIMD (single instruction multiple data) addition, SIMD multiplication and ciphertext permutation. Second, we implement the Gazelle homomorphic linear algebra kernels which map neural network layers to optimized homomorphic matrix-vector multiplication and convolution routines. Third, we design optimized encryption switching protocols which seamlessly convert between homomorphic and garbled circuit encodings to enable implementation of complete neural network inference. We evaluate our protocols on benchmark neural networks trained on the MNIST and CIFAR-10 datasets and show that Gazelle outperforms the best existing systems such as MiniONN (ACM CCS 2017) by 20 times and Chameleon (Crypto Eprint 2017/1164) by 30 times in online runtime. Similarly when compared with fully homomorphic approaches like CryptoNets (ICML 2016) we demonstrate three orders of magnitude faster online run-time

    Characteristics and phylogenetic analysis of the complete chloroplast genome of Rubus quinquefoliolatus T.T.Yu & L.T.Lu (family Rosaceae)

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    Rubus quinquefoliolatus T.T.Yu & L.T.Lu is a climbing shrub belonging to the Rosaceae family. It is widely distributed in the provinces of Yunnan and Guizhou in China. In this study, we sequenced the first complete chloroplast genome (cpDNA) sequence of R. quinquefoliolatus. The results showed a genome length of 156,489 bp, which is composed of a large single-copy (LSC) of 86,103 bp, small single-copy (SSC) of 18,844 bp, and two inverted repeats of 25,771 bp each. The whole chloroplast genome encodes 131 genes, including 86 coding sequences, 37 tRNAs, and eight rRNAs. Phylogenetic analysis revealed that R. quinquefoliolatus is closely related to R. lineatus and R. pentagonus

    Hierarchical Porous Carbon Derived from Sichuan Pepper for High-Performance Symmetric Supercapacitor with Decent Rate Capability and Cycling Stability

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    Hierarchical micro-mesoporous carbon (denoted as HPC-2 in this study) was synthesized by pre-carbonization of biomass Sichuan pepper followed by KOH activation. It possessed well-developed porosity with the specific surface area of 1823.1 m2 g−1 and pore volume of 0.906 cm3 g−1, and exhibited impressive supercapacitive behaviors. For example, the largest specific capacitance of HPC-2 was tested to be ca. 171 F g−1 in a three-electrode setup with outstanding rate capability and stable electrochemical property, whose capacitance retention was near 100% after cycling at rather a high current density of 40 A g−1 for up to 10,000 cycles. Furthermore, a two-electrode symmetric supercapacitor cell of HPC-2//HPC-2 was constructed, which delivered the maximum specific capacitance and energy density of ca. 30 F g−1 and 4.2 Wh kg−1, respectively, had prominent rate performance and cycling stability with negligible capacitance decay after repetitive charge/discharge at a high current density of 10 A g−1 for over 10,000 cycles. Such electrochemical properties of HPC-2 in both three- and two-electrode systems are superior or comparable to those of a great number of porous biomass carbon reported previously, hence making it a promising candidate for the development of high-performance energy storage devices

    Turbulence-Resistant All Optical Relaying Based on Few-Mode EDFA in Free-Space Optical Systems

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