Physical and numerical investigations of target stratum selection for ground hydraulic fracturing of multiple hard roofs

Ground hydraulic fracturing plays a crucial role in controlling the far-field hard roof,making it imperative to identify the most suitable target stratum for effective control.Physical experiments are conducted based on engineering properties to simulate the gradual collapse of the roof during longwall top coal caving(LTCC).A numerical model is established using the material point method(MPM)and the strain-softening damage constitutive model according to the structure of the physical model.Numerical simulations are conducted to analyze the LTCC process under different hard roofs for ground hydraulic fracturing.The results show that ground hydraulic fracturing releases the energy and stress of the target stratum,resulting in a substantial lag in the fracturing of the overburden before collapse occurs in the hydraulic fracturing stratum.Ground hydraulic fracturing of a low hard roof reduces the lag effect of hydraulic fractures,dissipates the energy consumed by the fracture of the hard roof,and reduces the abutment stress.Therefore,it is advisable to prioritize the selection of the lower hard roof as the target stratum.

Novel flavin-containing monooxygenase protein FMO1 interacts with CAT2 to negatively regulate drought tolerance through ROS homeostasis and ABA signaling pathway in tomato

Drought stress is themajor abiotic factor that can seriously affect plant growth and crop production.The functions of flavin-containing monooxygenases(FMOs)are known in animals.They addmolecular oxygen to lipophilic compounds or produce reactive oxygen species(ROS).However,little information on FMOs in plants is available.Here,we characterized a tomato drought-responsive gene that showed homology to FMO,and it was designated as FMO1.FMO1 was downregulated promptly by drought and ABA treatments.Transgenic functional analysis indicated that RNAi suppression of the expression of FMO1(FMO1-Ri)improved drought tolerance relative to wild-type(WT)plants,whereas overexpression of FMO1(FMO1-OE)reduced drought tolerance.The FMO1-Ri plants exhibited lower ABA accumulation,higher levels of antioxidant enzyme activities,and less ROS generation comparedwith theWTand FMO1-OE plants under drought stress.RNA-seq transcriptional analysis revealed the differential expression levels of many drought-responsive genes thatwere co-expressed with FMO1,including PP2Cs,PYLs,WRKY,and LEA.Using Y2H screening,we found that FMO1 physically interacted with catalase 2(CAT2),which is an antioxidant enzyme and confers drought resistance.Our findings suggest that tomato FMO1 negatively regulates tomato drought tolerance in the ABA-dependent pathway and modulates ROS homeostasis by directly binding to SlCAT2.

Genome-wide investigation of defensin genes in peanut(Arachis hypogaea L.)reveals AhDef2.2 conferring resistance to bacterial wilt

Peanut(Arachis hypogea L.)bacterial wilt(BW)is a devastating disease caused by Ralstonia solanacearum that results in severe yield and quality losses.Plant defensins are short cysteine-rich peptides with antimicrobial activity.The role of defensin genes(Ah Def)in peanut is unclear.A genome-wide investigation of Ah Def genes was undertaken,and 12 identified Ah Def genes were classified into two groups containing the gamma-thionin domain formed by four disulfide pairs:Cys1-Cys8,Cys2-Cys5,Cys3-Cys6,and Cys4-Cys7.In silico analysis revealed that Ah Def genes showed highly conserved architectural features and contained cis-elements associated with phytohormone signaling and defense responses.A highly resistant cultivar,H108(R)and a susceptible accession,H107(S)were tested by R.solanacearum inoculation.H108(R)showed fewer symptoms than H107(S)owing to inhibition of bacterial reproduction and spread in the vascular bundles of roots and stems.In a transcriptomic expression profile,Ah Def genes,particularly Ah Def1.6 and Ah Def2.2,were up-regulated in H108(R)compared with H107(S)under R.solanacearum infection and phytohormone treatment.Subcellular localization showed that the Ah Def1.6 and Ah Def2.2 proteins were both expressed specifically on the plasma membrane.Overexpression of protein fusion Ah Def2.2-YFP in Nicotiana benthamiana and peanut leaves increased resistance to R.solanacearum,suggesting its role in response to BW infection.Ah Def2.2 may be valuable for peanut resistance breeding.

Hemostatic and Anti-inflammatory Activities and High Performance Liquid Chromatography Analysis of Rotala rotundifolia and Its Preparations

[Objectives] To evaluate the hemostatic and anti-inflammatory activities of water extract and ethanol extract of Rotala rotundifolia and Shuijia Zhixue capsule. [Methods]The hemostatic activity of the extracts was evaluated by the changes of the bleeding time( BT),coagulation time( CT) and coagulation parameters including prothrombin time( PT),activated partial thromboplastin time( APTT) and thrombin time( TT) in mice or rats. The anti-inflammatory activity of the extracts was evaluated by carrageenan-induced foot edema,arachidonic acidinduced ear edema and xylene-induced ear edema models in rats. The content of gallic acid in ethanol extracts of R. rotundifolia and Shuijia Zhixue capsule was studied by HPLC to explore the correlation between gallic acid and anti-inflammatory activity. [Results]In hemostasis experiment,the ethanol extracts of R. rotundifolia and Shuijia Zhixue capsules showed significant shortening effects on BT,CT,PT and TT( P <0. 01-0. 05). The water extracts of R. rotundifolia and Shuijia Zhixue capsules had significant shortening effects on CT,PT and TT( P <0. 05),while the water extracts of R. rotundifolia had no hemostasis effect. In anti-inflammatory experiment in vivo,the two ethanol extracts showed significant shortening effects on CT,PT and TT and in the induction test of carrageenan,arachidonic acid and xylene,the inhibitory effects were significant( P < 0. 01-0. 05). The water extract from Shuijia Zhixue capsules had significant inhibitory effects on carrageenan-induced foot edema in rats( P < 0. 05),but the anti-inflammatory effects of water extract from R. rotundifolia were not significant. The content of gallic acid in R. rotundifolia and Shuijia Zhixue capsules were( 0. 318 62 ± 0. 009 8) and( 6. 295 2 ± 0. 162 6) mg/g,respectively.Among them,the content of gallic acid in Shuijia Zhixue capsule was significantly correlated with the anti-inflammatory activity of carrageenaninduced foot edema model. [Conclusions] Ethanol extract of R. rotundifolia and Shuijia Zhixue capsules has strong hemostatic and anti-inflammatory activities,and can be used in the treatment of traditional diseases such as bleeding and inflammation.

Effects of Biological Fertilizer and Paclobutrazol on Total Flavonoids in Ophiopogon japonicus

[Objectives] The research aimed to study the effects of applying biofertilizer instead of paclobutrazol on the content of flavonoids in Ophiopogon japonicas and determine its quality characteristics,in order to provide the scientific basis for the quality control of GAP and the comprehensive utilization of resources. [Methods] O. japonicas collected in Lingxing Town and Huayuan Town of Sichuan Province was divided into three groups: blank control group,paclobutrazol group and biofertilizer group. Root tuber of O. japonicas was obtained,and the enzyme was killed by the microwave,and then it was dried in 60℃. The content of flavonoids in root tuber of O. japonicus was determined by ultraviolet spectrophotometry. Then,SPSS19. 0 was used to analyze the results. [Results]The average contents of flavonoids in different treatments were as follows: 0. 184%-0. 198% in control group; 0. 283%-0. 330% in the paclobutrazol group; 0. 404%-0. 428% in the biofertilizer group. Biological bacterial fertilizer had a significant role in promoting the synthetic accumulation of homoisoflavonoids in O. japonicus( P <0. 001**). [Conclusions]The application of biological fertilizer can not only significantly improve the content of homoisoflavonoids in root ruber of O. japonicus,but also significantly optimize the micro ecological environment of soil. Therefore,biofertilizer should be widely used to gradually replace paclobutrazol in the main production areas of O. japonicas.

Determination of Gallic Acid in Rotala rotundifolia and Shuijia Zhixue Capsule by HPLC

[Objectives] To establish a method for the determination of gallic acid in Shuijia Zhixue capsule and Rotala rotundifolia .[Methods] High performance liquid chromatography (HPLC) and Phenomenex C 18 column were used, the mobile phase was 0.1% phosphoric acid∶ methanol=85∶ 15, the flow rate was 0.5 mL/min, and the detection wavelength was 270 nm.[Results] In the range of (2-25)μg/mL , the concentration of gallic acid had a good linear relationship with the peak area, r =0.990 8;the average recovery was 96.88%.[Conclusions] The method was simple, sensitive and reproducible. It provided a basis for the analysis of gallic acid in Rotala rotundifolia and Shuijia Zhixue capsule and the establishment of quality detection methods in the future.

Characteristics of Infrared Fingerprint of Gastrodia elata Blunme from Sichuan

[Objectives] The infrared fingerprint spectra of Gastrodia elata Blume of different origins and different varieties were studied.[Methods]One-dimensional infrared spectroscopy was used to analyze G. elata of different origins and different varieties. Based on the infrared spectra of 14 batches of G. elata,the common peak ratio and variant peak ratio were calculated,the double index sequences of common peak ratio and variant peak ratio were established to compare the similarities between the samples of G. elata. [Results] Infrared fingerprint spectra of G. elata of different origins and different varieties were obtained,and a total of 14 common peaks were calibrated. The maximum and minimum common peak ratios among the G. elata samples were 100. 00% and 73. 68%,respectively; and the maximum and minimum variant peak ratios were 21. 43% and 0%,respectively. [Conclusions]The combination of Fourier transform infrared spectroscopy and common peak ratio-variant peak ratio double-index analysis can provide scientific basis for the quality standard research of G. elata.

A Preliminary Study on the Infrared Spectra Characteristics of Radix Chuanmingshinis Violacei

[Objectives] To carry out infrared spectroscopic study of different growth years and different parts of the traditional Chinese medicine Radix Chuanmingshinis Violacei. [Methods]Using potassium bromide squash method and Fourier transform infrared spectroscopy on the different growth years and different parts of Radix Chuanmingshinis Violacei for infrared spectrum and second derivative spectrum. [Results]With the increasing growth time,Radix Chuanmingshinis Violacei accumulated in the secondary metabolism substances gradually increased,the characteristic absorption peak appeared in the position such as 3 366,2 927,1 634,1 416,1 516,1 080,1 020,and 928 cm^(-1),the main chemicals as polysaccharide,coumarin,saponins and steroids. The difference of chemical position between root tuber and cauline leaf is obvious. [Conclusions]Infrared spectroscopy was applied in studying different growing periods and different parts of Radix Chuanmingshinis Violacei,of obvious characteristics,identification and quality evaluation method,is simple and suitable for Radix Chuanmingshinis Violacei.

Application of Multivariate Analysis Method in Evaluation of Quality and Traits of Sichuan Ophiopogon japonicus

[Objectives] To study the relationship between the yield and total saponin content of Sichuan Ophiopogon japonicus. [Methods]The multi-indicator function model of Sichuan O. japonicus was established by using the multivariate analysis method and taking the yield of and total saponin content of Sichuan O. japonicus as indicators. [Results] In the multivariate non-linear fitting,the Pearson correlation test was used to reduce the dimension of the model,and the significant correlated variables were rejected,leaving three independent variables: the total fresh weight of the plant( x_1),the fresh weight of the aboveground part(x_2) and the fresh weight of fibrous roots(x_3),established the total saponin( y) function model for Sichuan O. japonicus: y = a_1+a_2x_2+ a_3x_3+ a_4x_1x_2+ a_5x_1x_3+ a_6x_2x_3+ a_7x_1~2+ a_8x_2~2+ a_9x_3~2.[Conclusions]When the total fresh weight of plant,fresh weight of aboveground part and fresh weight of fibrous roots were known in Sichuan O. japonicus root tuber,the total saponin content could be estimated by polynomial of these three variables. The establishment of this functional model system is expected to provide a scientific basis for the scientific prediction of the yield and total saponin content of Sichuan O. japonicus.

Experimental Study on Content of Aqueous Extract and Total Flavonoids in Different Parts of Sichuan Ophiopogon japonicus 1

[Objectives]To study the differences in the content of aqueous extract and total flavonoids in different parts of Sichuan Ophiopogon japonicus 1,and provide a scientific basis for the comprehensive utilization of O. japonicus resources. [Methods] According to Volume I of 2015 Chinese Pharmacopoeia,and with reference to literature methods,taking water as extraction solvent,hot dip method was used to determine the content of aqueous extract; taking ethanol as extraction solvent,the content of total flavonoids was determined using hot dip method,Ultraviolet-Visible Spectrophotometry. [Results]The content of aqueous extract and total flavonoids in the root tubers of Sichuan O. japonicus1 was higher than that of traditional O. japonicas; the content of aqueous extract in the root tubers of Sichuan O. japonicus 1 was higher than that in the leaves of Sichuan O. japonicus 1; the content of total flavonoids in leaves of Sichuan O. japonicus 1 was higher than that in the root tubers; the content of aqueous extract and total flavonoids in Sichuan O. japonicus 1 in the second year was higher than that in the first year.[Conclusions]The quality of new cultivar of Sichuan O. japonicas 1 was significantly higher than the traditional O. japonicus. Nowadays,the main part of drug use in O. japonicas is root,but as to the content of total flavonoids,fibrous roots and leaves are more dominant,it is feasible to develop and utilize the resources of flavonoids in the fibrous roots and leaves. The content of aqueous extract and total flavonoids from the second year O. japonicus was higher than that in the first year O. japonicus,but its increased amount did not meet the requirements of economic benefits.

Quality Characteristics and FTIR Research of Amorphophallus konjac K. Koch Cultivated under Forest

[Objectives]This study aimed to evaluate the quality characteristics of Amorphophallus konjac K.Koch and study the tubers of A.konjac K.Koch by infrared spectroscopy and second derivative method.[Methods]Referring to industrial standards of China for agriculture and related documents,the quality characteristics of A.konjac K.Koch were determined;and using potassium bromide tableting method and Fourier transform infrared spectroscopy,the infrared spectrum and second derivative spectrum of A.konjac K.Koch were studied.[Results]The drying rate,total ash content,acid-insoluble ash content,water extract content,ethanol extract content and crude polysaccharide content of A.konjac K.Koch were above 14.00%,4.57%-11.78%,0.04%-4.87%,26.31%-36.98%,2.20%-7.95%and 40.25%-61.18%,respectively.The infrared spectra of A.konjac K.Koch of different origins were relatively close,and the differences were mainly in peak intensity.The peaks at 1642,1322,1241,1154,1022,863,770 and 576 cm-1 were the main specific peaks.The main component was konjac glucomannan.[Conclusions]FTIR technology is simple and quick,and is suitable for quality control and sample identification of A.konjac K.Koch.This provides a scientific basis for the quality control and comprehensive utilization of A.konjac K.Koch cultivated under forest.

Virtual-Reality-Based Training System for the Improvement of the Driver’s Ability to Predict Dangers in Driving Situations

Improving the danger prediction during driving can significantly reduce the risk of accidents.However,previous danger prediction training systems had not been sufficiently effective owing to the lack of realism.In this study,we propose an immersive training system for danger prediction training using virtual reality(VR)technology.This system provides drivers with a highly realistic training environment with 360°videos viewed with VR goggles.Users can practice various dangerous scenarios in an environment that simulates a real-driving situation.In addition,we introduced a system to select dangerous spots with a controller and implement training schemes on a voluntary basis.This setup enables them to train in a highly interactive state.In addition,we proposed a method to express multiple indices numerically so that users can understand the training effect.We tested the effect of the system on the danger prediction abilities of various users with two experiments by using this approach.These results show that our system was more effective in improving the driver’s danger prediction ability than previous systems.

Effects of Spiral Magnetic Field on Structures Transformation and Macrosegregation of Sn-Pb Alloy

The effect of spiral magnetic field （SMF） on the solidification process of Sn-20 wt.%Pb hypoeutectic alloy was studied in this work. The temperature distribution and the macrosegregation together with the eutectic lamellar spacing during solidification were measured under different magnetic fields. The results indicate that the compositions in the top and bottom portions of the sample are nearly the same and the segregation phenomenon is basically eliminated by SMF at an exciting current of 125 A. The morphology of the primary phase transforms from coarse dendrite to rosette or ellipsoidal equiaxed crystal and the spacing of the eutectic lamellar increases from 1.6 to 3.9 μm when the exciting current increases from 0 to 125 A. Moreover, if the exciting current is high enough, the forced fluid flow caused by SMF will enhance the process of transition from lamellar eutectic structure to anomalous rod-like one.

A Rubik’s microfluidic cube

A Rubik’s cube as a reconfigurable microfluidic system is presented in this work.Composed of physically interlocking microfluidic blocks,the microfluidic cube enables the on-site design and configuration of custom microfluidics by twisting the faces of the cube.The reconfiguration of the microfluidics could be done by solving an ordinary Rubik’s cube with the help of Rubik’s cube algorithms and computer programs.An O-ring-aided strategy is used to enable self-sealing and the automatic alignment of the microfluidic cube blocks.Owing to the interlocking mechanics of cube blocks,the proposed microfluidic cube exhibits good reconfigurability and robustness in versatile applications and proves to be a promising candidate for the rapid deployment of microfluidic systems in resource-limited settings.