19 research outputs found
Characterization of the complete chloroplast genome of Dioscorea polystachya Turcz.
Dioscorea polystachya Turcz. is an important Chinese herbal medicine and the raw material of the medicine ingrediente (Chinese yam polysaccharide). It belongs to Dioscorea, which has 60 species and distribute in middle and southeast of China. In this study, we sequenced the sample of D. polystachya based on Jiaozuo, Henan and determined its complete chloroplast genome. The length of cp genome was 152,958 bp, includes two invert repeats (IR) regions of 25,492 bp, a large single-copy (LSC) region of 83,152 bp, and a short single-copy (SSC) region of 18,822 bp. There were 131 genes, which included 85 protein coding genes, 8 rRNA, and 38 tRNA, and overall GC content covered by 37.1%. Each of trnK-UUU, rps16, trnG-UCC, atpF, rpoC1, trnL-UAA, trnV-UAC, petB, petD, rpl16, rpl2, ndhB, trnI-GAU, trnA-UGC, and ndhA genes contained an intron, clpP and ycf3 contained 2 introns. The phylogenetic position showed that D. Polystachya had the closest relationship with Dioscorea alata (MG267382) and Dioscorea aspersa (NC039807)
Research on the Coal Seam Permeability-Increasing Technology via High-Pressure Water Jet Reaming and Its Application
Aiming at the problem of coal and gas outburst prevention and control in serious outburst dangerous coal seam under complex geological conditions in Qidong Coal Mine, the water jet drilling and expanding integrated device was used to implement the measures that expand holes and increase permeability by high-pressure water at a 912 working face. The experimental results show that when the pump pressure is between 13 MPa and 15 MPa, the particle size of pulverized coal can be effectively reduced and the discharge of pulverized coal can be increased. The coal output of a single hole is 0.8~2.3 t/m, with an average of 1.1 m/t. The unreamed conventional borehole has a single-hole initial gas drainage rate of 50.74 m3/d and a single-hole cumulative gas drainage rate of 736.12 m3 within 30 days. The initial single-hole gas drainage volume of the reaming borehole is 178.74 m3/d, and the cumulative single-hole gas drainage volume in 30 days is 2227.57 m3. After reaming, the initial gas drainage scalar of a single hole increases 3.52 times of the original unreamed conventional drilling and the average cumulative gas drainage scalar of a single hole reaches 3.03 times of the original unreamed conventional drilling. This technology and equipment have a good promotion and application value in gas treatment of soft, low-permeable coal seams
Stress Distribution and Gas Concentration Evolution during Protective Coal Seam Mining
Coal and gas burst is one of the significant and catastrophic hazards in underground longwall operations. To date, the protective coal seam mining has been recognized as the most effective mining method for minimizing or even avoiding the effect of the coal and gas burst. In this paper, numerical modelling and field test were carried out for the longwall operation in Qidong Coal Mine in order to investigate the induced stress and coal seam gas drainage performance in the protected coal seam after the complete extraction of the protective coal seam. It was found that four stress zones can be classified in the protected coal seam being the original stress zone, stress concentration zone, stress relief zone, and recompaction zone. In addition, the monitoring data of gas concentration and volume change in the field agree well with the numerical modelling results
Aerodynamic Response and Running Posture Analysis When the Train Passes a Crosswind Region on a Bridge
Trains running on a bridge face more significant safety risks. Based on the Unsteady Reynolds-Averaged Navier–Stokes turbulence model, a three-dimensional Computational Fluid Dynamics computational model of the train–bridge–wind barrier was proposed in this study to measure the transient aerodynamic load of the train. The transient aerodynamic load was input into the wind–train–bridge coupling dynamic system to perform dynamic analysis of running safety. Significant fluctuations in the aerodynamic coefficients were found when the train entered and exited the wind barrier due to the dramatic change in flow pattern. The maximum value of the derailment coefficient decreased with the height of wind barriers, which hardly affected the wheel load reduction rate. The 2 m high wind barrier had no evident influence on the running posture of a general high-speed train, while the 4 m high wind barrier was proven to have better protection. Over-protection was found with an even higher wind barrier
HSP22 suppresses diabetes-induced endothelial injury by inhibiting mitochondrial reactive oxygen species formation
The induction of mitochondrial reactive oxygen species (mtROS) by hyperglycemia is a key event responsible for endothelial activation and injury. Heat shock protein 22 (HSP22) is a stress-inducible protein associated with cytoprotection and apoptosis inhibition. However, whether HSP22 prevents hyperglycemia-induced vascular endothelial injury remains unclear. Here, we investigated whether HSP22 protects the vascular endothelium from hyperglycemia-induced injury by reducing mtROS production. We used a high-fat diet and streptozotocin injection model to induce type 2 diabetes mellitus (T2DM, metabolic syndrome) and exposed human umbilical vein endothelial cells (HUVECs) to high glucose following overexpression or silencing of HSP22 to explore the role of HSP22. We found that HSP22 markedly inhibited endothelial cell activation and vascular lesions by inhibiting endothelial adhesion and decreasing cytokine secretion. We performed confocal microscopy and flow cytometry assays using HUVECs and showed that HSP22 attenuated mtROS and mitochondrial dysfunction in hyperglycemia-stimulated endothelial cells. Mechanistically, using the mtROS inhibitor MitoTEMPO, we demonstrated that HSP22 suppressed endothelial activation and injury by eliminating hyperglycemia-mediated increases in mtROS. Furthermore, we found that HSP22 maintained the balance of mitochondrial fusion and fission by mitigating mtROS in vitro. HSP22 attenuated the development of vascular lesions by suppressing mtROS-mediated endothelial activation in a T2DM mouse model. This study provides evidence that HSP22 may be a promising therapeutic target for vascular complications in T2DM. Keywords: Hyperglycemia, HSP22, Inflammation, mtROS, Oxidative stress, T2D
Phosphine-Catalyzed [4 + 2] Annulation of Allenoate with Sulfamate-Derived Cyclic Imines: A Reaction Mode Involving γ′-Carbon of α‑Substituted Allenoate
A phosphine-catalyzed
[4 + 2] cycloaddition of cyclic α-substituted
allenoates with sulfamate-derived cyclic imines has been reported.
Using dibenzylphenylphosphine as the nucleophilic catalyst, the reaction
worked efficiently to yield various fused multicyclic heterocyclic
compounds in high yields with excellent diastereoselectivities. It
undergoes a new reaction mode involving γ′-carbon of
α-substituted allenoate
Lewis-Base-Catalyzed Asymmetric [3 + 3] Annulation Reaction of Morita–Baylis–Hillman Carbonates: Enantioselective Synthesis of Spirocyclohexenes
A Lewis-base-catalyzed
enantioselective [3 + 3] annulation reaction
of Morita–Baylis–Hillman (MBH) carbonates with α-arylidene
pyrazolinones is described, affording the pyrazolone-fused spirocyclohexenes
bearing an all-carbon quaternary stereocenter in high yields with
good to excellent diastereoselectivities and excellent enantioselectivities
Lewis-Base-Catalyzed Asymmetric [3 + 3] Annulation Reaction of Morita–Baylis–Hillman Carbonates: Enantioselective Synthesis of Spirocyclohexenes
A Lewis-base-catalyzed
enantioselective [3 + 3] annulation reaction
of Morita–Baylis–Hillman (MBH) carbonates with α-arylidene
pyrazolinones is described, affording the pyrazolone-fused spirocyclohexenes
bearing an all-carbon quaternary stereocenter in high yields with
good to excellent diastereoselectivities and excellent enantioselectivities
Lewis-Base-Catalyzed Asymmetric [3 + 3] Annulation Reaction of Morita–Baylis–Hillman Carbonates: Enantioselective Synthesis of Spirocyclohexenes
A Lewis-base-catalyzed
enantioselective [3 + 3] annulation reaction
of Morita–Baylis–Hillman (MBH) carbonates with α-arylidene
pyrazolinones is described, affording the pyrazolone-fused spirocyclohexenes
bearing an all-carbon quaternary stereocenter in high yields with
good to excellent diastereoselectivities and excellent enantioselectivities