Evaluation of installation timing of initial ground support for large-span tunnel in hard rock

In conventional drill and blast tunnelling, initial ground support is placed immediately after the current round is shot before excavation of the next round (i.e. one-round installation method). When tunnelling in hard rock, one-round installation of initial ground support conservatively ensures tunnel integrity, but meanwhile brings up other problems such as over-break at tunnel face, slow excavation rate and so forth. In this study, a large-span tunnel in Class III hard rock was monitored by a network of sensors to investigate tunnel internal forces in three construction scenarios where initial ground supports were placed in different timing and sequence: (1) initial ground support installed immediately after current round (2) support installed after two rounds (3) support installed after three consecutive rounds. The collected field measurements together with construction records were evaluated from three aspects: structural stability, constructability and cost-effectiveness. Results show that the installation of initial ground support after two rounds generally led to the most regular and minimum tunnel internal forces of the three construction scenarios, whilst it managed to minimize under & over-break and allow more space for construction convenience. In the meanwhile, this installation sequence significantly accelerated tunnel advance rate at lower material cost

Kir6.1- and SUR2-dependent KATP over-activity disrupts intestinal motility in murine models of Cantu Syndrome

Cantύ Syndrome (CS), caused by gain-of-function (GOF) mutations in pore-forming (Kir6.1, KCNJ8) and accessory (SUR2, ABCC9) ATP-sensitive potassium (KATP) channel subunit genes, is frequently accompanied by gastrointestinal (GI) dysmotility, and we describe one CS patient who required an implanted intestinal irrigation system for successful stooling. We used gene-modified mice to assess the underlying KATP channel subunits in gut smooth muscle, and to model the consequences of altered KATP channels in CS gut. We show that Kir6.1/SUR2 subunits underlie smooth muscle KATP channels throughout the small intestine and colon. Knock-in mice, carrying human KCNJ8 and ABCC9 CS mutations in the endogenous loci, exhibit reduced intrinsic contractility throughout the intestine, resulting in death when weaned onto solid food in the most severely affected animals. Death is avoided by weaning onto a liquid gel diet, implicating intestinal insufficiency and bowel impaction as the underlying cause, and GI transit is normalized by treatment with the KATP inhibitor glibenclamide. We thus define the molecular basis of intestinal KATP channel activity, the mechanism by which overactivity results in GI insufficiency, and a viable approach to therapy

DeepFacePencil: Creating Face Images from Freehand Sketches

In this paper, we explore the task of generating photo-realistic face images from hand-drawn sketches. Existing image-to-image translation methods require a large-scale dataset of paired sketches and images for supervision. They typically utilize synthesized edge maps of face images as training data. However, these synthesized edge maps strictly align with the edges of the corresponding face images, which limit their generalization ability to real hand-drawn sketches with vast stroke diversity. To address this problem, we propose DeepFacePencil, an effective tool that is able to generate photo-realistic face images from hand-drawn sketches, based on a novel dual generator image translation network during training. A novel spatial attention pooling (SAP) is designed to adaptively handle stroke distortions which are spatially varying to support various stroke styles and different levels of details. We conduct extensive experiments and the results demonstrate the superiority of our model over existing methods on both image quality and model generalization to hand-drawn sketches.Comment: ACM MM 2020 (oral

Mineralization of organic matter in microbialites and implications for microbialite reservoirs in Member IV of the Leikoupo Formation, Sichuan Basin, China

Microbialites are important reservoirs for oil and gas. The mineralization of organic matter in microbialites during early diagenesis can produce acidic fluids that dissolve carbonate grains, and can also result in an alkaline pore water that precipitates cement. The mineralization of organic matter in microbialites and its effect on microbialite reservoirs have not yet been studied in detail. In this study, quantitative statistical analysis of the two-dimensional spatial occurrence of pores and microbial fabrics, in situ geochemical analysis of specific components (microbial, transitional zone, and fine spar fabrics), and qualitative evaluation of the implications for microbialite reservoirs were undertaken on microbialites from Member IV of the Leikoupo Formation, Sichuan Basin, China. The quantitative statistical analysis shows that pores are spatially associated with microbial fabrics, but porosity has a poor correlation with microbial fabric content. In situ geochemical data indicate that microbialites with different porosities experienced different processes of organic matter mineralization. The processes of organic matter mineralization such as oxidation and nitrate reduction can provide more dissolution micropores than the process related with sulfate reduction, whereas the process of organic matter mineralization related with Fe–Mn oxide reduction results in cementation. Micropores created by organic matter mineralization can act as fluid channels for later dissolution and are important in the development of microbialite reservoirs

A TRPV4-dependent neuroimmune axis in the spinal cord promotes neuropathic pain

Microglia, resident macrophages of the CNS, are essential to brain development, homeostasis, and disease. Microglial activation and proliferation are hallmarks of many CNS diseases, including neuropathic pain. However, molecular mechanisms that govern the spinal neuroimmune axis in the setting of neuropathic pain remain incompletely understood. Here, we show that genetic ablation or pharmacological blockade of transient receptor potential vanilloid type 4 (TRPV4) markedly attenuated neuropathic pain-like behaviors in a mouse model of spared nerve injury. Mechanistically, microglia-expressed TRPV4 mediated microglial activation and proliferation and promoted functional and structural plasticity of excitatory spinal neurons through release of lipocalin-2. Our results suggest that microglial TRPV4 channels reside at the center of the neuroimmune axis in the spinal cord, which transforms peripheral nerve injury into central sensitization and neuropathic pain, thereby identifying TRPV4 as a potential new target for the treatment of chronic pain

Development of energy plants from hybrids between Miscanthus sacchariflorus and M. lutarioriparius grown on reclaimed mine land in the Loess Plateau of China

Miscanthus, a promising bioenergy plant, has a high biomass yield with high cellulose content suitable for biofuel production. However, harsh climatic and poor soil conditions, such as barren lands or abandoned mines, pose a challenge to the survival and yield of Miscanthus feedstock on the marginal land. The selection from the interspecific hybrids of Miscanthus might combine high survival rates and high yield, which benefits energy crop development in multi-stressful environments. A total of 113 F1 hybrids between Miscanthus sacchariflorus and M. lutarioriparius together with the parents were planted and evaluated for multiple morphological and physiological traits on the mine land of the Loess Plateau of China. The majority of hybrids had higher establishment rates than M. sacchariflorus while M. lutarioriparius failed to survive for the first winter. Nearly all hybrid genotypes outperformed M. lutarioriparius for yield-related traits including plant height, tiller number, tiller diameter, and leaf area. The average biomass of the hybrids was 20 times higher than that of surviving parent, M. sacchariflorus. Furthermore, the photosynthetic rates and water use efficiency of the hybrids were both significantly higher than those of the parents, which might be partly responsible for their higher yield. A total of 29 hybrids with outstanding traits related to yield and stress tolerance were identified as candidates. The study investigated for the first time the hybrids between local individuals of M. sacchariflorus and high-biomass M. lutarioriparius, suggesting that this could be an effective approach for high-yield energy crop development on vast of marginal lands

Improvement of mechanical properties of noil hemp fiber reinforced polypropylene composites by resin modification and fiber treatment

The present study aims to improve the reinforcement of hemp fibre to polypropylene (PP) by simple resin modification and fibre treatment. Maleic anhydride grafted polypropylene (MAPP) was used as resin modifier by direct mixing with PP, and hydrophobically modified hydroxyethyl cellulose (HMHEC) was used as fibre treatment reagent by immersing fibre into its aqueous solution. The influences of fibre content, resin modification, and fibre treatment on the mechanical properties (tensile, flexural, and impact strengths) of composites were investigated. The change of interfacial bonding between fibre and resin in composites caused by MAPP and HMHEC was studied by scanning electron microscopy and dynamic mechanical analysis. Resin modification and fibre treatment were effective to enhance the mechanical properties of the composites. The improvement in interfacial bonding is quantitatively evaluated with adhesion factor