Search

An N–H functionalization of O-substituted hydroxamic acid with diazo esters under blue LED irradiation conditions has been developed.

Two prevailing trends in livestock production include increasing farm sizes and higher recycling rates of manure. Using beef cattle farms in China as a case study, we examine the impact of farm size on farmers' choice of manure disposal modes. Three forms of manure disposal modes are identified: (1) selling to neighboring farmers, (2) giving away to neighboring farmers and (3) self-use. Based on primary data from a field survey of beef cattle farmers in China, we estimate the choice of the above-mentioned three disposal modes using the constrained singular Seemingly Unrelated Regression (SUR) model. We find a significant and nonlinear impact of farm size on farmers' choice of manure disposal modes. Specifically, there is a significant and inversed U-shaped relationship between farm size and manure giving away, and a significant U-shaped relationship between farm size and manure selling or self-use. We additionally find several other factors that affect farmers' choice of manure disposal: the educational level of a farmer has a positive impact on manure selling; the better a farmer's physical health condition, the more likely the farmer self uses manure and less likely gives it away; land acquisition, as well as engagement in crop farming, increases manure self-use and reduces manure giving away and selling; the availability of manure treatment facilities reduces manure self-use; and the willingness of nearby crop growers to accept manure significantly decreases manure self-use and increases manure selling and giving away. Policy implications are also discussed.

Sorghum with longer mesocotyls is beneficialfor improving its deep tolerance, which is important for the seedling rates. Here, we perform transcriptome analysis between four different sorghum lines, with the aim of identifying the key genes regulating sorghum mesocotyl elongation. According to the mesocotyl length (ML) data, we constructed four comparison groups for the transcriptome analysis and detected 2705 common DEGs. GO and KEGG enrichment analysis showed that the most common category of DEGs were involved in cell wall, microtubule, cell cycle, phytohormone, and energy metabolism-related pathways. In the cell wall biological processes, the expression of SbEXPA9-1, SbEXPA9-2, SbXTH25, SbXTH8-1, and SbXTH27 are increased in the sorghum lines with long ML. In the plant hormone signaling pathway, five auxin-responsive genes and eight cytokinin/zeatin/abscisic acid/salicylic acid-related genes showed a higher expression level in the long ML sorghum lines. In addition, five ERF genes showed a higher expression level in the sorghum lines with long ML, whereas two ERF genes showed a lower expression level in these lines. Furthermore, the expression levels of these genes were further analyzed using real-time PCR (RT-qPCR), which showed similar results. This work identified the candidate gene regulating ML, which may provide additional evidence to understand the regulatory molecular mechanisms of sorghum mesocotyl elongation.

Pest and disease control outsourcing has become an effective means to restore damaged arable land and guarantee agroecological benefits. However, it is adopted at a relatively low rate in China. The purpose of this study is to explore, from the perspective of government intervention, behavioral logic, and the game relationship among farmers, service organizations and the government in the pest and disease control outsourcing system as well as the endogenous motivation of each subject. The results indicate that when the degree of policy implementation is low, the government’s policy is ineffective, but, after reaching a certain level, the higher the degree of policy implementation is, the stronger the farmers’ willingness to choose outsourcing control and the service organizations’ willingness to provide positive control services are, and the faster the stable state of tripartite joint pest and disease control is formed. In the case of implementing a single policy tool, the convergence rate of each party that implements the regulatory policy alone is fast but may be unstable, while the rate is slow but more stable when a guidance- or incentive-based policy is solely applied. The effect of a combination of policy tools being applied is much better than that of a single policy tool being applied. The simultaneous implementation of the three types of policy tools can form a policy system with both positive and negative mechanisms, which can maximize the complementary and superposition effects.

Background: NEDD8 (neural precursor cell expressed developmentally downregulated protein 8) is one of the ubiquitin-like proteins which is activated by the NEDD8 activating enzyme (NAE). The overexpressed NAE can cause a variety of diseases such as numerous cancer types and inflammatory diseases. The selective inhibition of NAE could mediate the rate of ubiquitination and the subsequent degradation of proteins associated with cancer so as to achieve the purpose of treatment. Objective: In this article, we decided to study the synthesis and screening of coumarin scaffold derivatives against cancer cell lines, specifically the human pancreatic cancer cell line BxPC-3. Methods: Twenty-four targeted compounds were synthesized, and their anti-proliferative activity against three cancer cell lines, cytotoxicity against three normal cell lines through CCK-8 and MTT assay were evaluated to screen out the candidate compound. Then the target was further confirmed by both enzyme and cell-based experiments, as well as cell apoptosis research. Results: Several new 4-position substituted coumarin derivatives (12a~x) were synthesized and most of them exhibit antiproliferative activity in three cancer cell lines. A series of experiments were performed to identify the best candidate compound 12v. This compound displayed the highest potency against BxPC-3 with an IC50 value of 0.28 μM. It can also inhibit NAE activity in enzyme and cellbased assay, and induce CRLs-mediated accumulation of the substrate and apoptosis in BxPC-3 cells. Meanwhile, it exhibited relatively low toxicity in three normal cells. Conclusion: Based on these results, we found that compound 12v inhibited NAE activity in enzyme and cell-based systems and induced apoptosis in BxPC-3 cells. Additionally, it also had a low toxicity. These results suggested that 12v may be promising lead compounds for the development of new anticancer drugs.

Due to the double layer airgap configuration, the even-order harmonic components exist in the phase back electromotive force (EMF) of flux-modulation electrically-excitation double-stator synchronous machine (FMEE-DSM), thus resulting in relatively high torque ripples. To promptly and effectively suppress these torque ripples, this paper proposes and implements a second-order iterative learning control (ILC) strategy to minimize the main harmonic torque components based on the periodically repetitive characteristic of torque ripples in the FMEE-DSM. Via harmonic analysis on the torque ripples caused by the cogging torque and the non-sinusoidal induced EMFs, the dominative harmonic component, namely, the 7th order component, can be precisely identified and then involved in the proposed ILC for torque ripple suppression. To verify the feasibility of proposed control strategy, a test bench of the FMEE-DSM control system was built based on dSPACE 1103. Accordingly, both the static and dynamic performances of the FMEE-DSM were investigated under the conditions of no-load and rated load. The theoretical analysis, computer simulation and hardware experimentation are given to verify the proposed second-order ILC.

The kinetics of the Beckmann rearrangement of cyclohexanone oxime (CHO) catalyzed by trifluoroacetic anhydride (TFAA) and trifluoroacetic acid (TFA) is proposed in this work. The effects of experimental parameters on the reaction rate are studied in microreactors, including CHO concentration, TFAA concentration, temperature, and caprolactam (CPL) concentration. The reaction is verified as first-order and the reaction rate shows a linear relationship with TFAA concentration and decreases with the increasing of CPL concentration. The in-situ FTIR is adopted to study the reaction mechanism and quantitative equilibrium relationship of CPL with TFAA. Based on the experimental results, a reaction mechanism is proposed and a kinetics model is established, which is in good agreement with the experimental data. The TFAA/TFA catalytic system allows high conversion and reaction rate compared with other organic acids.

The purpose of this study is to explore, from the perspective of government interven-tion, behavioral logic and game relationship among farmers, service organizations and the gov-ernment in the pest and disease control outsourcing system, as well as the endogenous motiva-tion of each subject. The results indicate that the stronger the willingness of each subject, the faster the stable state of joint pest and disease control among the three parties can be formed; In the case of implementing a single policy tool, the convergence rate of each party that imple-ments the regulatory policy alone is fast but may be unstable, while the rate is slow but more stable when a guidance- or incentive-based policy is solely applied; The effect of policy tool combination is much better than that of a single policy tool applied. The simultaneous imple-mentation of the three types of policy tools can form a policy system with both positive and negative mechanisms, which can maximize complementary and superposition effect.

The low thermal conductivity of gypsum-based composites containing phase change materials (PCMs) has limited their application in construction materials. In this study, the mechanical and thermal properties and microstructures of paraffin (PA)/gypsum composites containing iron powder, copper powder, and expanded graphite were characterized by a universal testing machine, thermogravimetry, differential scanning calorimetry, and scanning electron microscopy. The PA/gypsum composites had optimal mechanical properties when the PA content was 20 wt.%. The compressive and flexural strengths were 9.46 MPa and 3.57 MPa, respectively. When the copper powder content increased, the densities and porosities of the PA/gypsum composites containing the copper powder did not largely change. The average density and porosity of the composites were 1.17 g/cm3 and 46%, respectively. The compressive and flexural strengths of the PA/gypsum composite containing 8 wt.% copper powder were optimal. A phase change temperature of 48.8 °C was obtained when 8 wt.% copper powder was added to the PA/gypsum composite. The thermal conductivities of the PA/gypsum composites were lower than those of PA/gypsum composites with 8 wt.% iron powder, 8 wt.% copper powder, or 8 wt.% expanded graphite. Parts of coarse calcium sulfate dihydrate crystals were present at the interfaces between the gypsum and PA, which indicated that the growth of calcium sulfate dihydrate crystals was affected by the copper powder.

Background: The single-leg landing is one of the maneuvers that has been linked to non-contact ACL injuries, and knee braces have been shown to reduce ACL injury incidence. The purpose of this study was to determine whether a knee brace has an effect on muscle force during single-leg landings at two heights through musculoskeletal simulation.Methods: 11 healthy male participants were recruited to complete single-leg landings at 30 cm and 45 cm between the braced and non-braced. We recorded trajectories and ground reaction force using an 8-camera motion capture system and a force platform. The captured data was imported into the generic musculoskeletal model (Gait2392) in OpenSim. Static optimization was used to calculate muscle forces. Results: The gluteus minimus, rectus femoris, vastus medialis, vastus lateralis, vastus medialis medial gastrocnemius, lateral gartrocnemius, and soles muscle forces all showed statistically significant differences between the braced and non-braced. Simultaneously, increasing landing height significantly affected gluteus maximums, vastus medialis, and vastus intermedia muscle forces. Conclusions: Our findings imply that the knee brace may be able to alter muscle forces in single-leg landings to prevent anterior cruciate ligament injury. Additionally, research demonstrates that people should avoid landing from heights due to the increased risk of knee injuries.