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In order to establish a rapid detection method for Aeromonas hydrophila utilizing recombinase polymerase amplification (RPA) technology, we designed specific RPA primers based on the conserved sequence of the gyrB gene of Aeromonas hydrophila. The research included the optimization of reaction conditions and an assessment of specificity and sensitivity by both agarose gel electrophoresis (AGE) and lateral flow dipstick (LFD) chromatography. The experimental results showed that the established rapid detection for Aeromonas hydrophila could detect Aeromonas hydrophila within 30min at the optimal temperature of 38°C. The minimum limit of detection (LOD) for Aeromonas hydrophila pure culture and genomic DNA using the RPA-LFD method was determined to be 10³ cfu/mL and 100 pg/μL, respectively. Furthermore, the simultaneous detection of clinical samples from hybridized sturgeon, treated using our established RPA-LFD method, exhibited consistent results when compared to conventional PCR. In conclusion, the recombinase polymerase amplification combined with lateral flow test strip (RPA-LFD) method of Aeromonas hydrophila was successfully established by exploring and optimizing RPA reaction conditions. The method was characterized by its simplicity, rapid reaction time, and lack of reliance on expensive instrumenttion compared with conventional PCR. Importantly, this method provides effective technical support for the early diagnosis of sturgeon suffering from bacterial diseases caused by Aeromonas hydrophila in the future. [ABSTRACT FROM AUTHOR]

As a new industry, donkey industry plays an important role in rural economic development. Scholars at home and abroad have conducted relevant research on the nutritional requirements and feed of donkeys, but there are still some data on nutritional requirements that are vacant. The article mainly reviews the current status of donkey breeding and the needs of donkeys for water, energy, protein, amino acids, fats, fatty acids, minerals and vitamins, as well as functional feed additives, and coarse and refined grain applications, to provide reference for efficient donkey feeding, compound feed development and healthy development of donkey breeding industry. [ABSTRACT FROM AUTHOR]

This article reviews various oxidants and catalysts commonly used in catalytic oxidation desulfurization processes,evaluates them,and prospects for the future. The production of green fuel oil is of great significance for reducing environmental pollution and protecting the ecological environment. In order to fully meet the new requirements of sulfur content standards, sulfur-containing compounds ( such as thio-phene and its derivatives) must be effectively removed from fuel oil. Compared with high investment costs and harsh reaction conditions, hydrodesulfurization (HDS) and oxidative desulfurization (ODS) have the advantages of mild reaction conditions, mild operating conditions, and high desulfurization efficiency. [ABSTRACT FROM AUTHOR]

To analyze and compare the volatile components in raw Crataegus pinnatifida and its processed products (i.e., its fried and charred products), headspace solid phase microextraction together with gas chromatography-mass spectrometry was used. Area normalization was used to calculate the relative contents of volatile components as percentages. In addition, principal component analysis (PCA) was performed. In total, 76 components were detected, among which 72 components were identified. Thirty-four peaks were detected and 29 components were identified from raw C. pinnatifida, accounting for 98.35% of the volatile components present. In the fried products, 41 peaks were detected and 33 components were identified. These accounted for 97.15% of the volatile components present. Lastly, 48 peaks were detected and 36 components were identified from the charred products, accounting for 84.78% of the volatile components present. There are five common volatile components in the three products, but the contents of these components are different in the products. Meanwhile, the PCA comprehensive scores of the three products varied significantly. Raw and fried products scored higher than charred products. The composition and content of volatile components in C. pinnatifida have changed considerably after processing, and the medicinal value of fried C. pinnatifida is relatively high. [ABSTRACT FROM AUTHOR]

Objective To summarize the treatment methods and effects of pediatric germ cell tumors in pineal region. Methods and Results Clinical data of 28 children with primary intracranial pineal region germ cell tumors from March 2012 to December 2019 were analyzed retrospectively. The clinical manifestations include high intracranial pressure symptoms, parinaud symptoms and precocious puberty. Seven patients were diagnosed as germinoma indirectly by diagnostic radiotherapy/chemotherapy, the rest patients were confirmed by pathological examination: 15 mixed germ cell tumors, 3 mature teratomas, 2 malignant teratomas and 1 choriocarcinoma. Managements: 7 cases were continued to complete chemotherapy after being confirmed effective by diagnostic chemotherapy or radiotherapy. Three cases were underwent chemotherapy before operation, ineffectively, and were underwent operation after the tumor progressed, and 18 cases were directly resected. The operative approach was via longitudinal fissure-corpus callosum-fornix in 15 cases and infratentorial supracerebellar approach in 6 cases. Total resection was performed in 16 cases, subtotal resection in 3 cases and partial resection in 2 cases. The serum tumor markers of all children decreased significantly after surgery, with an average of 69.55% . The average hospital stay was 19.35 d for all. At the time of discharge from hospital, one patient abandoned treatment due to coma, the remaining 27 patients with headache, nausea and vomiting, and other symptoms of high intracranial pressure significantly relieved. There were 10 cases of secondary hydrocephalus, and symptoms of high intracranial pressure recurred. The symptoms disappeared after the shunt. The cases in this group were followed up for an average of 2.53 years, and 7 cases of germinoma had no recurrence. Fifteen cases with mixed germ cell tumors had a complete remission of 8/15; one patient gave up treatment after surgery; 5/15 of relapses, of which 2 recurred in situ, 2 recurred in ventricular dissemination, one recurred in spinal cord disseminated; and one case (1/15) died of tumor progression 23 months after surgery. There were no recurrences in 5 cases with teratoma. One case with choriocarcinoma died of tumor progression 4 months after surgery. Conclusions There are various types of germ cell tumors in the pineal gland in children. Mixed germ cell tumors are more common. Serological tumor markers are of great significance in diagnosis and treatment. Surgery combined with standardized chemoradiotherapy is an important treatment method. The use of multi-disciplinary diagnosis and treatment mode and individualized precise treatment can significantly extend the survival of patients. [ABSTRACT FROM AUTHOR]

For satellite navigation and positioning receiver is easy to be interferenced by the multipath, this paper presented an accurate tracking method which was based on maximum likelihood estimation and Kalman filtering for multipath BOC (n,n) signal. Firstly, the method made coherent integral accumulation for the receiving signal, and then estimated amplitude and delay of the signal by the method of maximum likelihood, next estimated the estimated result again by Kalman filtering, so got the more accurate multipath amplitude and delay under the low carrier-to-noise ratio. Finally, it used multipath estimation delay lock loop to analyze the phase curves and showed its validity by a simulation experiment. Theory and simulation results show that the method can track multipath BOC (n,n) signal accurately under the low carrier-to-noise ratio. [ABSTRACT FROM AUTHOR]

The blind periodic estimation of the PN sequence in variable-spreading-length(VSL) multirate direct-sequence code division multiple access(DS / CDMA) systems is considered. The method of the reprocessing of the power spectrum which is used to estimate the period of general DS-SS signal is extended to multirate DS / CDMA model. Firstly, the received signal is sampled and its power spectrum is estimated, then Fourier transform is directly used to the power spectrum to modulo and square the value,and so repro? cessing of the power spectrum is obtained. The derivation proves that the power spectrum reprocessing of the multirate DS / CDMA signal will arise varied amplitude sharp pulse with interval equal to the period of these different rates users' PN sequence, accordingly, the periods of the different rates users' PN sequence can be acquired. The computer simulation results show that the method can work well under the lower signal-to-noise ratio(SNR) input signals and it is able to estimate many rates by taking advantage of less data at the same time at -15 dB SNR. [ABSTRACT FROM AUTHOR]

In order to solve the blind recognition problem of the high rate Reed Solomon(RS) codes, this paper presents a blind recognition method based on Galois Field columns Gaussian elimination. Firstly, code length and symbolic number are recognized by using the difference function of the matrix rank. Then the primitive polynomials corresponding to the number of symbol at this time are traversed. And the matrix is eliminated with columns in Galois field. By using the difference of entropy, the primitive polynomial is identified. Finally, as the code word polynomial roots are found, the continuous roots are the roots of the generator polynomial. Code length, the primitive polynomial and the generator polynomial are identified by the method. The tedious process of Galois field Fourier transform is avoided. Simulation results show that the recognition probability is higher than 90% at an error code rate of 3x10-3. [ABSTRACT FROM AUTHOR]

For the blind estimation problem of pseudo code period and combination code(combination of spread spectrum sequence and subcarrier sequence) for BOC(Binary-Offset-Carrier) signals with residual carrier at the low signal-to-noise ratio(SNR), the method which combines the second power spectrum with matrix decomposition is proposed. First, this method calculates the second power spectrum of BOC signals with residual carrier. There are sharp pulses appearing at the integer times period of the pseudo code. Detecting distance of these peaks can estimate the period of the pseudo code. Then the sampling signals are sectioned according to the period of the pseudo code to get the data vector. The correlation matrix of the data vector is calculated and matrix decomposition of the correlation matrix is performed. The combined code sequence can be estimated with the two largest singular values and their vectors. The simulation results show that the method has accurate estimation performance for the signals with larger residual carrier at the lower SNR. The research in this paper has a certain reference value for those engaged in satellite navigation receiver design. [ABSTRACT FROM AUTHOR]

In forging production line, solving the problem of workpiece calibration by the traditional method is low efficiency and poor accuracy, so a visual calibration method is proposed to get the posture relationship between robot and workpiece. To obtain the intrinsic and extrinsic parameters of camera, a calibration toolbox is used to extract grid corners and calibrate the plane calibration template. A teaching workpiece's coordinates experiment is used to test the validity of the method above. The experimental result shows that the robot could finish the workpiece grasping job quickly and accurately, the average error of workpiece coordinate is within 0.3% and the accuracy of the calibration can meet the requirements of the actual production line. [ABSTRACT FROM AUTHOR]

In order to solve the problem of the OFDM broadband signal processing, this paper introduced a algorithm for the direction of arrival (DOA) estimation of OFDM signal based on the wideband signal covariance matrix sparse representation. It averaged the triangle elements in the lower left corner of the main diagonal of the covariance matrix to form a new vector, and wrote the vector in the form of a redundant dictionary. The signal in a redundant dictionary the sparsity constraints formed a second-order cone constrained optimization problems, and then used toolbox SeDuMi to do DOA estimation. Theoretical analysis and simulation results show that the proposed method is an effective wideband signal DOA estimation algorithm and has high resolution in low signal-to-noise ratio and less number of snapshots, it is better than higher order cumulant algorithm and wideband focused matrix algorithm DOA estimation method. [ABSTRACT FROM AUTHOR]

In order to reduce the complexity of ACELP ( algebraic code excited linear prediction), and achieve a better operation in real-time system, this paper proposed an effective algorithm. First, it proposed the discontinuous open-loop pitch estimation in adaptive codebook search, used the time decimation factor in different delays, and then proposed the unified pulse-replacement search algorithm in stochastic codebook search, used the prediction technique and judging mechanism to control the number of codebook search. Finally, it simulated the improved algorithm in G. 729A. The result shows that the proposed algorithm not only acquires complexity reduction but also get a high speech quality. [ABSTRACT FROM AUTHOR]

Aiming at the problem that single man-machine interface is difficult to monitor running state of multiple PLCs in automation system, a feasible and effective approach to network monitoring is proposed. At first, the communication network for PPI between multiple PLCs is built. So each PLC becomes a site in the network. Furthermore, in order to monitor each PLC site in the network by monitoring the entire network, the entire network for PPI is configurated under the MCGS configuration environment. Finally, with the platform for DLMPS-727S2, the experiment based on the above idea is done. And the result shows that the system can simultaneously monitor multiple PLCs, and is high reliability and real-time, and it has good application value. [ABSTRACT FROM AUTHOR]