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Background Sugarcane is the most important sugar crop, contributing > 80% of global sugar production. High sucrose content is a key target of sugarcane breeding, yet sucrose improvement in sugarcane remains extremely slow for decades. Molecular breeding has the potential to break through the genetic bottleneck of sucrose improvement. Dissecting the molecular mechanism(s) and identifying the key genetic elements controlling sucrose accumulation will accelerate sucrose improvement by molecular breeding. In our previous work, a proteomics dataset based on 12 independent samples from high- and low-sugar genotypes treated with ethephon or water was established. However, in that study, employing conventional analysis, only 25 proteins involved in sugar metabolism were identified . Results In this work, the proteomics dataset used in our previous study was reanalyzed by three different statistical approaches, which include a logistic marginal regression, a penalized multiple logistic regression named Elastic net, as well as a Bayesian multiple logistic regression method named Stochastic search variable selection (SSVS) to identify more sugar metabolism-associated proteins. A total of 507 differentially abundant proteins (DAPs) were identified from this dataset, with 5 of them were validated by western blot. Among the DAPs, 49 proteins were found to participate in sugar metabolism-related processes including photosynthesis, carbon fixation as well as carbon, amino sugar, nucleotide sugar, starch and sucrose metabolism. Based on our studies, a putative network of key proteins regulating sucrose accumulation in sugarcane is proposed, with glucose-6-phosphate isomerase, 2-phospho-D-glycerate hydrolyase, malate dehydrogenase and phospho-glycerate kinase, as hub proteins. Conclusions The sugar metabolism-related proteins identified in this work are potential candidates for sucrose improvement by molecular breeding. Further, this work provides an alternative solution for omics data processing.

In this review, we have summarized the research progress on stability of solid acid catalysts. Three reasons for the deactivation of solid acids and corresponding catalytic activity improvement are discussed by taking several examples, giving a good inspiration for the study and development of stable solid acid catalysts in the future.

Silkworm silk fiber is an attractive material owing to its remarkable mechanical characteristics, excellent optical properties, and good biocompatibility and biodegradability. However, nano-processing of the silk fiber is still a challenge limiting its applications in nanoengineering and related fields. Herein, we report localized near-field enhancement-assisted ablation with an ultrafast laser to break this bottleneck. Localized processing of silk fiber, including nano-holing, nano-grooving, and cutting could retain the key molecular structure building blocks and the pristine functionality of the silk fiber. An extremely narrow nanohole with a width of ~64 nm was successfully achieved. The processed silk fiber can be used to transfer micro/nanoparticles and drugs, showing potential for biomedical engineering. The processing strategy developed in this study can also be extended to other materials, paving a new way for fabricating functional nanostructures with precisely controlled size and morphology.

To enhance ergot alkaloid production of Claviceps purpurea Cp-1 strain by epigenetic modification approach. The chemical epigenetic modifiers were screened to promote ergot alkaloid production of the Cp-1 strain. The histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) was found to significantly enhance the alkaloid productivity of the strain. Particularly, the titers of total ergot alkaloids were gradually increased with the increase of SAHA concentration in the fermentation medium, and the highest production of ergot alkaloids could be achieved at the concentration of 500 μM SAHA. Specially, the titers of ergometrine and total ergot alkaloids were as high as 95.4 mg/L and 179.7 mg/L, respectively, which were twice of those of the control. Furthermore, the mRNA expression levels of the most functional genes in the ergot alkaloid synthesis (EAS) gene cluster were up-regulated under SAHA treatment. It was proposed that SAHA might increase histone acetylation in the EAS gene cluster region in the chromosome, which would loosen the chromosome structure, and subsequently up-regulate the mRNA expression levels of genes involved in the biosynthesis of ergot alkaloids, thereby resulting in the markedly increase in the production of ergot alkaloids. The ergot alkaloid production by the C. purpurea Cp-1 strain can be effectively increased by the application of histone deacetylase inhibitor. Our work provides a reference for using the chemical epigenetic modifiers to improve SM production in other fungi.

Large quantities of solid wastes, including gangue (waste rock) have been added to the goafs in China’s coal mines as backfill. In this study, the mineral and chemical compositions of gangue from the No. 12 coal mine of the Pingdingshan Coal Group were investigated to determine potential pollution concerns, and the behaviour of contaminants in the gangue, such as salts, alkali metals, and alkaline earth metals, was explored using static immersion tests. COMSOL Multiphysics was used to study contaminant migration. The concentration and diffusion distance of metal ions were found to increase over time; this was negatively correlated with gangue particle size. Acidic environments promoted the dissolution of Ca, Fe, Mn, Na, Zn, Pb, and Be, while in alkaline environments, Se dissolution was accelerated.

The combination of gold nanoparticles and metal–organic frameworks is one of the new directions of current research. It has applications in many aspects, especially as a catalyst for a variety of reactions. Therefore, this paper describes recent progress of synthesis and application in Au@MOFs hybrid materials.

The oxidation of cyclohexane to cyclohexanone, cyclohexanol, and adipic acid, which are important raw materials in nylon industry, is still being challenged in conventional processes. Microreactors and gold catalysts are both widely researched areas at present, so an effort was made to make use of collaborative properties of both. In this study, stainless steel microcapillary coated with a supported nano-gold catalyst was prepared, characterized, and employed for the oxidation of cyclohexane. Under the temperature of 180 °C, residence time of 4 min, reaction pressure of 3 MPa and molar ratio of oxygen to cyclohexane of 0.3:1, the conversion of cyclohexane was 2.09%, with the selectivity of cyclohexanol, 29.37%; cyclohexanone, 39.89%; cyclohexyl hydroperoxide, 2.46%; and adipic acid, 18.87%. Experiments showed that stainless steel microcapillary coated with a supported nano-gold catalyst in cyclohexane oxidation is a feasible process; the reaction time is very short, and the process operation runs safely.

During the curing process of a composite shell, the temperature field of the composite is influenced by the temperature inside the stove, the heat transfer between the mold and the composite, and the heat released by the curing reaction of the resin matrix. In the case of thick-walled shells, the coefficient of heat conduction and the permeability of the composite along the thickness direction are significantly lower than the corresponding values in the plane. Together with the combined action of the mold and the environment, this effect makes the temperature distribution significantly complex. In this paper, a simulation of the curing process was performed by using the finite element method. The distribution and evolution of the temperature field and degree of cure field were simulated. In particular, we assessed the influence of three different mold materials, namely 45# steel, aluminum, and copper, on the temperature field and degree of cure field. The present research provides the theoretical basis and an analytical method for improving the molding efficiency and quality, as well as the design and optimization, of molds.

Through the 5-channel SWAES digital full waveform AE detector, the paper dealt with the fracture process of coal and rock samples under uniaxial compression. Using wavelet operations of multi-scale discrete analysis the pulses of a particular time period (points) and the space domain signal by numerical method were gotten, and the paper concluded that the signal singularity in load rupture had closely relations with fracture and uniaxial compression. The detected position and the actual breaking point only differed at one sample point, the relative error was 6.82%, and there was no accumulative error. Thus it provided an effective method to solve the problem of instability analysis of the signal singularity detection and coal-rock compression failure in the whole process.

Direct quadrature modulation technology is suitable for wide-band radar signal generation. However, this method has rigorous requirements on amplitude and phase balance of the orthogonal input signals. If the requirements are not satisfied, there would be modulation errors such as image frequency and oscillator leakage that cannot be filtered. The modulation errors will therefore raise the noise floor of the range profile and reduce the dynamic range of the Synthetic Aperture Radar (SAR) image as a whole. In this paper, the wide-band In-phase/Quadrature-phase (I/Q) modulation errors are modeling analyzed, and the influence of wide-band I/Q modulation errors on SAR imaging is discussed. Furthermore, a compensation method of modulation errors is proposed, and the circuit implementation of the radar signal generation and pre-distortion is presented. The experimental results illustrate that the curves of the I/Q amplitude and phase imbalance errors are successfully extracted and the rejection of image frequency improved significantly, thus meets the requirements of the SAR imaging.

The quality of ring spun yarns is largely determined by its level of hairiness. The existence of hairiness inevitably affects the quality of ring spun yarns. This paper presents an innovative method on lowering the level of hairiness of ring spun yarns. This can be achieved by shooting compressed air to the yarn, through a swirl nozzle comprising a yarn duct and an airjet nozzle attached to a traditional ring spin frame. When compressed air is applied from the air-jet nozzle to the yarn duct, the swirling air flow tucks surface fibers of the ring spun yarns into its body. Four controllable variable parameters for the process, supplied pressure, nozzle position, twist factor and spindle speed, and their effects on the lowering of yarn hairiness will be clarified. Their impact on the quality of the yarn is statistically analyzed, and the optimum outcome of the combination of parameters for the process, will thus be determined.

This paper focuses on the problem of linear track keeping for marine surface vessels. The influence exerted by sea currents on the kinematic equation of ships is considered first. The input-to-state stability (ISS) theory used to verify the system is input-to-state stable. Combining the Nussbaum gain with backstepping techniques, a robust adaptive fuzzy algorithm is presented by employing fuzzy systems as an approximator for unknown nonlinearities in the system. It is proved that the proposed algorithm that guarantees all signals in the closed-loop system are ultimately bounded. Consequently, a ship’s linear track-keeping control can be implemented. Simulation results using Dalian Maritime University’s ocean-going training ship ‘YULONG’ are presented to validate the effectiveness of the proposed algorithm.

Amorphous silica was modified by doping with titania through a surface sol–gel process and applied as the support for depositing gold. These doped silica-supported gold catalysts were tested in the selective cyclohexane oxidation to cyclohexanone and cyclohexanol using oxygen. Under the oxidation conditions of 150 °C, 1.5 MPa and 3 h, a selectivity of 91.7% for cyclohexanone and cyclohexanol could be reached over the gold catalyst, affording a cyclohexane conversion of 8.4% and a turnover frequency up to 40,133 per hour. Moreover, the catalytic activity and selectivity could be well retained in 4 recycling oxidation reactions, showing a high stability of the gold catalyst supported on titania-doped silica.

The selective oxidation of cyclohexane to cyclohexanone and cyclohexanol has been investigated over Au/Al2O3 catalysts using molecular oxygen in a solvent-free system. The catalysts were prepared by a modified direct anionic exchange method and characterized by AAS, N2 adsorption and TEM. The results showed that the catalytic performance of Au/Al2O3 is very high in terms of turnover frequency. Moreover, the nano-size effect of gold is also reported in the reaction.

The study of Ervatamia yunnanensis Tsiang, growing in Yunnan and Guangxi provinces of China, has focused on the isolation of alkaloids [1–6], which are demonstrated to have significant anti-addictive, anti-malarial, anti-reproductive, and anticancer activities [7, 8]. About 30 indole alkaloids have been isolated from E. yunnanensis Tsiang. Continuing our investigations into the biologically active constituents of nonalkaloid parts of Ervatamia yunnanensis by chromatographic and spectroscopic methods, we have isolated two lignans (1 and 2), five flavonoids (6, 9, 11, 13, and 14), two triterpenoids (7 and 8), three organic or fatty acids and derivatives (3, 4, and 12), vanillin (10), and one aromatic ketone (5). The plant material was collected in May 2003 at Xishuangbanna, Yunnan province and identified as the stems of Ervatamia yunnanensis Tsiang by Senior Engineer Wang Hong, Xishuanbanna Tropical Plant Garden of the Chinese Academy of Sciences. The air-dried and powdered stems and branches (5 kg) were extracted with 95% EtOH (10 L) by reflux. The percolate was evaporated in vacuum to yield the EtOH extract (425 g), which was suspended in 2% HCl solution. The precipitate in the lower layer after centrifugation, which was deplete of alkaloids, was dissolved in distilled water; then the solution was chromatographed over macroporous adsorptive resin AB-8, eluting with a gradient mixture of water and alcohol. The compositions of fractions were analyzed by TLC. Similar fractions were combined to afford fraction A, 60.0 g (30% alcohol); fraction B, 40.0 g (60% alcohol), and fraction C, 15.0 g (90% alcohol). Fractions A, B, and C were subjected to repeated chromatography on silica-gel columns eluting with a gradient mixture of petroleum ether–ethyl acetate or chloroform–methanol, Sephadex LH-20 eluting with chloroform–methanol, methanol, or a gradient mixture of methanol–water, and C-18 reverse silica-gel columns eluting with a gradient mixture of methanol–water. A total of fourteen compounds (1–14) was isolated and identified based on NMR and mass spectrum, and by direct comparison with authentic samples and the literature. All the identified compounds are known compounds and are reported for the first time from Ervatamia yunnanensis. (+)-Isolariciresinol-9-O-D-glucopyranoside (1), white crystalline powder, C26H34O11, ESI-MS: m/z 521 [M – H]–, 545 [M + Na]+. 1H NMR (300 MHz, CD3OH, , ppm, J/Hz): 3.81, 3.80 (each 3H, OCH3 2), 4.10 (1H, d, J = 7.8, H-Glu-1), 6.17 (1H, s, H-5 ), 6.63 (1H, dd, J = 8.1, 1.8, H-6), 6.64 (1H, s, H-2 ), 6.73 (1H, d, J = 8.1, H-5), 6.79 (1H, d, J = 1.8, H-2). 13C NMR (75 MHz, CD3OH, ): 148.9 (C-3), 147.2 (C-3 ), 145.9 (C-4), 145.2 (C-4 ), 38.7 (C-1), 134.4 (C-6 ), 129.2 (C-1 ), 123.2 (C-6), 117.4 (C-5 ), 116.1 (C-5), 114.4 (C-2), 112.4 (C-2 ), 69.5 (C-9), 65.2 (C-9 ), 48.4 (C-7), 45.9 (C-8), 39.6 (C-8 ), 33.9 (C-7 ), 105.2 (Glc-1), 78.2 (Glc-5), 77.9 (Glc-3), 75.2 (Glc-2), 71.7 (Glc-4), 62.8 (Glc-6) [9]. Isolariciresinol (2), white powder, C17H26O10, ESI-MS: m/z 383 [M + Na] +. 1H NMR (600 MHz, CD3OD, , ppm, J/Hz): 1.78 (1H, m, H-2), 2.00 (1H, m, H-3), 2.75 (2H, d, J = 8.0, H-4), 3.39 (1H, dd, J = 4.0, 12.0, H-9b), 3.63–3.84 (10H, m, H-1, 10, H-9a, 2 OCH3), 6.20 (1H, s, H-8), 6.61 (1H, dd, J = 9.0, 2.4, H-6 ), 6.63 (1H, s, H-5), 6.68 (1H, d, J = 2.4, H-2 ), 6.75 (1H, d, J = 9.0, H-5 ). 13C NMR (150 MHz, CD3OD, ): 112.2 (C-5), 128.7 (C-5 ), 115.8 (C-5 ), 148.7 (C-6), 123.1 (C-6 ), 145.7 (C-7), 134.0 (C-1 ), 117.3 (C-8), 138.5 (C-8 ), 113.8 (C-2 ), 147.2 (C-3 ), 145.3 (C-4 ), 65.6 (C-10), 61.8 (C-9), 56.2, 56.2 (2 OCH3), 48.1 (C-2), 47.7 (C-1), 39.7 (C-3), 33.5 (C-4) [10]. Berchemolide (3), white powder, C28H32O16, ESI-MS: m/z 647 [M + Na] +, 1271 [2M + Na]+. 1H NMR (600 MHz, DMSO-d6, , ppm, J/Hz): 3.20–4.50 (H-Glu), 3.78 (6H, s, OCH3 2), 5.29 (2H, d, J = 7.2, H-1 , 1 ), 7.36 (2H, d, J = 8.4, H-5, 5 ), 7.40 (2H, d, J = 1.8, H-2, 2 ), 7.74 (2H, dd, J = 1.8, 8.4, H-6, 6 ).