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The study aimed to investigate the changes of metabolites and related flavors in the muscle of fresh mandarin fish (Siniperca chuatsi) during 24 h of postmortem refrigeration at 4 ℃ by ultra performance liquid chromatography coupled with high resolution mass spectrometry (UPLC-HR-MS). Non-targeted metabolomics was applied for multivariate statistical analysis, metabolic pathway analysis and related flavor calculation of the differential metabolites after 0 versus 2, 4, 6, 9, 12 and 24 h. The results showed that 33 differential metabolites were identified, including 3 organic acids and derivatives (amino acids and organic acids); 8 organic heterocyclic compounds (purines, purine derivatives and lactones); 7 nucleosides, nucleotides and analogues (purine nucleosides, purine nucleotides and pyrimidine nucleotides); 9 organic oxygen compounds (carbohydrates and their conjugates, as well as a small amount of alcohols); 4 lipid and lipid molecules (fatty alcohols and fatty acid esters); 1 flavonoid glycoside; and 1 alkaloid or its derivatives. Through metabolomic pathway analysis (MetPA) and Kyoto Encyclopedia of Genes and Genomes analysis, 9 key differential metabolites were identified including succinic acid, L-aspartic acid, 5’-adenosine monophosphate (AMP), inosine, adenyl succinic acid, xanthine, 5’-guanosine monophosphate (GMP), ribose 5-phosphate, and hypoxanthine. The major metabolic pathway involving these key differential metabolites was purine metabolism, followed by L-aspartic acid metabolism, glutamic acid metabolism and the tricarboxylic acid (TCA) cycle. By calculating the relative taste activity value (RTAV) and relative equivalent umami concentration (REUC), it was found that umami amino acids such as L-aspartic acid together with AMP and GMP mainly contributed to the taste of fresh mandarin fish, while the major taste compounds were AMP and GMP after 2–6 h of refrigeration and GMP after 9–24 h. Overall, the taste of fresh mandarin fish was best. During 24 h of storage at 4 ℃, the umami of mandarin fish decreased due to a decrease in L-aspartic acid content, but it increased between 9 and 24 h due to the accumulation of GMP.

Oblivious transfer protocol, an important technology in secure multi-party computation, is the research hotspot on network and information security.Based on the bilinear pairs and the difficult problems on elliptic curves, an efficient 1-out-of-N oblivious transfer protocol in the semi-honest model and in the standard malicious model were proposed respectively.The protocol in semi-honest model was designed.It only needed two rounds of interaction.The receiver needed two times of bilinear pair arithmetic and one time of multi point arithmetic, and the sender needed n times of multi point arithmetic and n times of modular exponentiation.The security of the protocol was based on the discrete logarithm problem on elliptic curves.A zero-knowledge proof protocol and the oblivious transfer protocol in the standard malicious model were proposed respectively.The oblivious transfer protocol only needed four rounds of interaction.The receiver needed three times of bilinear pair arithmetic and three times of multi point arithmetic, and the sender needed n+1 times of multi point arithmetic and n+1 times of modular exponentiation.Besides, it can resist malicious behaviors of the party.The results show that the average running time of the protocol in the semi-honest model and in the standard malicious model were 0.787 9 s and 1.205 6 s respectively, which can further demonstrate the efficiency of the protocol.

In order to explore the bacterial community composition of mung bean sour pulp, the core element of Luoyang traditional and special pulp noodles, the bacteria 16S rDNA of mung bean sour pulp from six pulp workshops in Lu-oyang was sequenced using Illumina MiSeq high-throughput sequencing technology. The results showed that 8 bacterial phyla were identified from 6 samples of mung bean sour pulp, involving 75 genera and 106 species; and Firmicutes is the dominant phylum (78.57%-97.17%), Lactobacillus (20.95%-90.36%) and Lactococcus (3.26%-62.68%) are the dominant genus, Lactobacillus oligofermentans, unclassified_Lactococcus are the corresponding dominant species, while Lactobacillus plantarum, Lactobacillus curvatus and Lactobacillus manihotivorans are common sub dominant bacteria. These dominant bacteria are all lactic acid bacteria, which have extensive prebiotic effects. The functional prediction of the bacterial community in mung bean sour pulp showed that the carbohydrate metabolism and amino acid metabolism abundance of the bacterial community are high, especially the abundance of flavor amino acid metabolic pathway and L-lactate dehydrogenase are relatively high. It was inferred that the unique acid and flavor of mung bean sour pulp was related to the bacterial amino acid metabolism and lactic acid synthesis. The results of this study provided a theoretical basis for further study on the fermentation mechanism of mung bean sour pulp and development of corresponding starter. [ABSTRACT FROM AUTHOR]

After a hundred years of development, college Chinese has accumulated a large number of teaching materials which can be divided into four categories : literary language, cultural language, writing language and combined language. Regardless of the type, cultivating students' "one ability and two consciousnesses" should be regarded as the core concept followed in the construction of textbooks for this course. Facing the requirements of the construction of new liberal arts in the new era, aiming at the college students trained by the new curriculum standard of Chinese in middle school, it is believed that writing is the embodiment of the high-order function of Chinese teaching, so we should pay special attention to the cultivation of students' creative writing ability and advocate the creation and compilation of new interdisciplinary integrated and systematic textbooks : one is the integration of reading and creative writing, and the other is the integration of communication, etiquette, eloquence and applied writing. A good textbook should make great efforts to stimulate students ' "expressive internal drive". [ABSTRACT FROM AUTHOR]

In order to study the development mode and realization way of smart agriculture, the technical route of agricultural information fusion of agricultural machinery in different production stages before, during and after wheat production was designed. Pre-production: 1) using Beidou precision navigation technology and motion planning optimization method to realize the full area coverage path planning of the field operation of the automatic navigation tractor; 2) combining the laser leveling equipment to realize the accurate and standardized land leveling and laser leveling; 3) realizing the accurate and standardized operation of the land. On this basis, the spatial interpolation technology was used to make the variable fertilization prescription map and combining variable rate fertilizer machine and realize variable rate precise application of fertilizer and precise seeding. At the same time, combining with the optimal design of planting scheme, based on the prenatal database and knowledge base, it optimized the decision-making of variety configuration and sowing time and seeding amount were optimized, and the software intelligent decision-making technology was used to recommend the varieties and sowing time and seeding amount suitable for planting at the decision-making point, and the wheat and maize prenatal information service recommendation system based on web geographic information systems(WebGIS) was constructed. In production: based on the image technology of automatic segmentation and color feature extraction of wheat image in the field environment, a remote monitoring model of wheat nutritional status with the function of wheat population image segmentation and nutritional estimation was established to realize the non-destructive monitoring of wheat nutritional status in the field environment. After production: the integrated measurement sensor, speed sensor, header height sensor and global positioning system(GPS) were adopted, and controller area network bus was adopted with wireless communication technology, a real-time wheat yield measurement system, which was installed on a large-scale combine harvester to carry out the real-time prediction service of wheat yield was developed to realize the synchronous process of wheat harvest and yield measurement, with the error less than 5%. The intelligent transformation of common agricultural machinery equipment and the research and development of sowing and harvesting equipment adapted to agricultural production were completed and realized, and the small scale with high-efficiency utilization of light and heat resources, increase of output and green development were studied. The model of wheat planting production was optimized. A real time measurement and prediction system for postpartum yield was developed, which included the selection of sowing date, fertilization recommendation, seedling growth and nutrition diagnosis. The experimental results showed that the adoption of agricultural information fusion technology could increase wheat yield by 18.4%, input-output ratio by 16.6% and 7.9%, which shows that the intelligent agriculture of Henan province is effective and feasible.

BackgroundVariable temperature condition is the most extensive requirement in many scattering experiments. Automatic sample shifting technology based on the variable temperature condition can significantly improve the detection efficiency of samples.PurposeThis study aims to develop a varied temperature automatic sample shifting device for synchrotron radiation small angle X-ray scattering (SAXS) experiment.MethodsThe device was designed to accommodate up to 100 samples, covering a wide temperature range of 25~280 °C with temperature control accuracy of ±1 °C. Two-dimensional mobile platform was used to control sample switching, and the temperature controller and heating element were used to control the sample temperature of experiment. In addition, the temperature-stroke coupling control software suitable for this device was implemented to realize the remote control of sample switching and temperature changing. The structure and the temperature distribution of the sample rack were analyzed by numerical simulation and compared with that of experiment to finalize the appropriate structure for this device.Results & ConclusionsThe maximum error between the simulated temperature and the measured temperature is less than 2% and the structure design is reasonable, satisfying multi-sample variable temperature test requirements for SAXS experiment.

The signal acquisition is a prerequisite for fault analysis and diagnosis,but also the necessary condition in the fault diagnosis of wind turbine gearbox. At present,the most mature method is vibration signal analysis method,however,because the internal structure of the gearbox can not be destroyed,it can only lead to vibration sensor installed on the external wall of the gearbox. The sensors arrangement of gearbox will directly influence the quality of diagnostic accuracy. By using the immune algorithm to solve the problem of sensor arrangement in fault diagnosis of wind turbine,the gearbox vibration source coordinates is constructed,the optimal acquisition path of vibration transmission is calculated,the best measuring point is determined. The placement optimization of the measuring point for sensor is realized,an effective method for sensor arrangement is provided.

Electrochemical machining (ECM) was conducted on TC17 titanium alloy followed by vibration finishing (VF). The surface integrity of TC17 titanium alloy treated after ECM and VF were analyzed by using scanning electron microscope, three-dimensional white light interferometer, and residual stress analyzer. The tensile and vibration fatigue properties of TC17 titanium alloy treated by different methods was also tested at room temperature. The results showed that the surface of TC17 titanium alloy was smooth with a much lower roughness and a relatively high compressive residual stress after ECM and VF. The grain orientation of TC17 titanium alloy was almost unaffected due to the slight plastic deformation of its surface. The TC17 titanium alloy treated by ECM and VF showed an equivalent tensile strength at room temperature to the one treated by ECM, while the vibration fatigue property of the former at room temperature was better than that of the later. [ABSTRACT FROM AUTHOR]

The maneuvering parameter identification of non-cooperative atrcraft is studied when the known information is sparse orbit elements. In this paper, a maneuver parameter identification method based on orbit inveryion and its corresponding solution algorithm are proposed. Firstly, the orbit invertion model and the maneuvering parameier identification optimization model are established. Then, a double optimization algorithm of "global optimization plus local correction" is proposed. Finally, the maneuvering parameter identification method proposed is verified by simulation. The results show that the double optimization method can effectively solve the optimization model, and the proposed method can effectively identify maneuvering parameiers within an acceptable error range. The research provides an idea for maneuvering identification of non-cooperative aircraft with lifted information, and ensures the on-orbit safety of spacecraft to a certain extent. [ABSTRACT FROM AUTHOR]

The three-impuise trajectories are optimally designed for the emergency return problem in the runned lunar landing mission. The motion equations of lunar return trajectories are adopted in the spherical frame based on the model of the restricted three body problem. The Moon-Earth emergency return trajectories concerning the constraints of circular orbit plane, minimum safe distance wtth respect to the Moon and terminal perigee height are optimized globally by using the multistart algorithm. The effectiveness and responsibility of the proposed approach are demonstrated by the simulation tests finally, according to a great deal of simulation results by the method, the effects of different orbit parameters on optimization objective are analyzed. The research conclusions can provide references for the design of emergency return trajectory scheme in the manned lunar landing mission in the future. [ABSTRACT FROM AUTHOR]

In order to solve the problems of the iterative soft thresholding algorithm (ISTA) that convergence rate is slow and the obtained optimal solution is not enough sparse, an improved algorithm called SFISTA based on the gradient algorithm is proposed. The algorithm modifies the gradient operator in the ISTA iterative method, so that the solution of the iterative point xn+1 depends on the iteration of the first two steps. Applying SFISTA to sparse signal processing and sparse principal component analysis, the experimental results show that the new algorithm not only can improve the convergence rate of ISTA, but can also promote the sparsity of the optimal solution. [ABSTRACT FROM AUTHOR]

One of the most abundant biological volatile organic compounds (BVOCs) in the atmosphere, monoterpene, is characterized by its short lifetime, low concentration, fast temporal and spatial variations, and wide variety of isomers. In this study, a multi-capillary column (MCC) was combined with high-pressure photoionization time-of-flight mass spectrometry (HPPI-TOF MS) and employed to develop an MCC-HPPI-TOF MS combination instrument as an online two-dimensional gas chromatography-mass spectrometry (GC-MS) method for the rapid qualitative and quantitative analysis of monoterpene isomers. As a result, six monoterpene isomers, α -pinene, β -pinene, α -terpinene, γ -terpinene, 3-carene, and limonene, were successfully isolated in 180 s with limits of detection (LODs) as low as 6 μg/m 3 without sample pre-enrichment. This method was successfully applied to the rapid online analysis of monoterpenes released from the branches and leaves of Cedrus atlantica and Sabina chinensis , which shows the capability and potential application of the method for the online detection of complex sample mixtures in environmental monitoring, process analysis, and other fields.

Objective: To investigate the expression of miR-29b in cholangiocarcinoma and explore its effects on cell proliferation and apoptosis of cholangiocarcinoma cells., Methods: Real-time PCR was used to detect the expression of miR-29b in cholangiocarcinoma cells line QBC939 and cholangiocarcinoma tissues. The lentiviral vector LV-hsa-miR-29b and blank vector were constructed to infect QBC939 cells. MTT assay and cell clone formation assay were performed to assess the changes in the cell proliferation and clone formation, respectively; flow cytometry was employed to evaluate the effect of miR-29b overexpression on cell cycle and apoptosis., Results: The expression of miR-29b was significantly down-regulated in QBC939 cells and cholangiocarcinoma tissues as compared with H-69 cells and normal tissues ( P < 0.01). Compared with the blank vector, the lentiviral vector LV-hsa-miR-29b caused significantly increased expression of miR-29b in QBC939 cells ( P < 0.01), which exhibited suppressed cell proliferation and clone formation ( P < 0.01 or 0.05), cell cycle arrest at the S phase ( P < 0.05), and significantly increased cell apoptosis ( P < 0.01)., Conclusions: As a tumor-suppressing miRNA, miR-29b is down-regulated in cholangiocarcinoma, and its overexpression can suppress the proliferation and induce apoptosis of cholangiocarcinoma cells.

A novel analytical method coupling gas chromatography (GC) with single photon ionization time-of-flight mass spectrometry (SPI-TOF MS) has been developed. First of all, a double-wall-tube transfer line was built to combine GC with SPI-TOF MS, which realized seamless connection between GC and SPI ion source. Based on this, standard n-pentadecane and benzene/toluene/xylene standard gas mixtures were used to study important voltage parameters of the ion source. After the optimization of the ion source voltages, pure molecular ion peaks of the analytes were obtained in the mass spectra and qualitative analysis of different kinds of organic compounds were eventually realized rapidly and accurately. At last, GC/SPI-TOF MS was applied to the characterization of volatile and semvolatile organic compounds in diesel and two-dimensional spectra of GC×SPI-TOF MS were obtained. Without complicated spectra interpretation and data processing, volatile and semi-volatile organic compounds in diesel have been classified qualitatively by ion mass-to-charge ratio (m/z) in SPI mass spectra, including aliphatic compounds, aromatic compounds and nitrogen-containing compounds with low concentration such as benzopyrroles. Isomeric compounds in diesel were separated and identified by retention times of chromatographic peaks. The results indicate that the proposed analytical method of GC/SPI-TOF MS is suitable for the characterization of complicated samples such as diesel and environmental pollutants with easy operation and high efficiency.

The method of detecting trace 1,4-dioxane in water using membrane extraction coupled with gas chromatography/differential mobility spectrometry (GC/DMS) was developed. The parameters including radio frequency voltage, sampling flow rate, permeation time and trapping time were optimized to 1000 V, 50 mL/min, 30 min and 150 s, respectively. The linear range for dioxane was obtained from 2.0 μg/L to 20.0 μg/L. The LOD was found to be 0. 67 μg/L. The specificity towards 1,4-dioxane in the presence of five chlorinated hydrocarbons was improved by using two-dimensional GC separation with optimized DMS compensation voltage. This method paves a way for developing field-deployable sensors for real-time monitoring contaminants in groundwater.

A nano-electrospray ionization-ion mobility spectrometer (nanoESI-IMS) was built up. Firstly, the effects of the parameters such as drift gas flow rate and solvent flow rate on the desolvation capability were studied and optimized. Then, a series of compounds were used to characterize the nanoESI-IMS system. The results showed that, complete desolvation was achieved for nano-electrospray ion droplets with the nanoESI-IMS apparatus. The limit of detection of this instrument for trioctylamine could reach 10 microg/L. Finally, this instrument was coupled to the high performance liquid chromatography (HPLC) as a detector for amines analysis. A test mixture containing triethylamine, diethylamine and butylamine was successfully separated and determined by the HPLC-nanoESI-IMS system. Linear response ranges of about two orders of magnitude were achieved for triethylamine, diethylamine and butylamine with this system.

Objective: To investigate the effect of linear polarized infrared light irradiation on the proliferation of primary cultured rabbit articular chondrocytes irradiation., Methods: Primary cultured rabbit articular chondrocytes were irradiated with linear polarized infrared light irradiation (Super Lizer) at the power intensity of 20% (360 mW) to 100% (1800 mW) for 5 min per day for 5 days, and CCK-8 assay was used to measure the proliferative activity of the chondrocytes after the exposures., Results: The D(450) values of the cells irradiated at the power intensity of 60% (1080 mW) and 80% (1440 mW) (1.88∓0.11 and 1.99∓0.05, respectively) were significantly greater than that of the control cells (0.95∓0.38, P<0.05). The irradiation with Super Lizer at lower (20%, 360 mW and 40%, 720 mW) or higher (100%, 1800 mW) power intensities did not cause significant increases of the D(450) values. Compared with the control group, Super Lizer irradiation at the power intensities of 20%, 40%, 60%, and 80% resulted in increment ratios of chondrocyte viability of (48.75∓15.4 )%, (67.02∓29.61)%, (97.93∓11.57)%, and (108.52∓5.81)%, respectively, but at 100% power intensity (1800 mW), the irradiation caused a lowered chondrocyte viability increment ratio of (62.84∓31.12)%., Conclusion: Linear polarized infrared light irradiation can promote the proliferation of chondrocytes in an intensity-dependent manner, and the strongest effect occurs with the irradiation power intensity of 80% (1440 mW).

Ion mobility spectrometry (IMS) is an attractive detector of gas chromatography (GC) due to its high sensitivity, short response time, and comparatively low cost. The hyphenated GC-IMS instrument can simultaneously provide high separation ability of GC and high sensitivity of IMS. In this paper, one setup of a GC-IMS instrument is introduced. The parameters of IMS as the GC detector were evaluated and studied with respect to the resolution and sensitivity including temperature, total voltage and drift gas flow rate. Under the optimal conditions, GC-IMS was used to detect iodomethane, 1,2-dichloroethane, tetrachloromethane and dibromomethane and the detection limits were 2, 0.02, 1 and 0.1 ng, respectively. And the linear ranges of two orders of magnitude were achieved. As the detector of gas chromatography, IMS can provide more information for compound identification because of its second dimensional separation and can realize selective detection of different compounds.