scholarly journals A Simple and Efficient Method to Isolate LTR Sequences of Plant Retrotransposon

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Da-Long Guo ◽  
Xiao-Gai Hou ◽  
Xi Zhang
Keyword(s):  
Molecular Markers ◽  
Efficient Method ◽  
High Efficiency ◽  
Size Structure ◽  
Restriction Enzymes ◽  
Rnase H ◽  
Plant Genome ◽  
New Method ◽  
Tree Peony ◽  
Time Saving

Retrotransposons (RTNs) have important roles in the formation of plant genome size, structure, and evolution. Ubiquitous distributions, abundant copy numbers, high heterogeneities, and insertional polymorphisms of RTNs have made them as excellent sources for molecular markers development. However, the wide application of RTNs-based molecular markers is restricted by the scarcity of the LTR (long terminal repeat) sequences information. A new, simple, and efficient method to isolate LTR sequences of RTNs was presented based on the degenerate RNase H nested primers and PPT (polypurine tract) primer of RTNs in tree peony. This method combined the characteristics and advantages of high-efficiency thermal asymmetric interlaced PCR (hiTAIL-PCR), annealing control primer (ACP) system, and suppression PCR method. Nineteen LTR sequences were isolated using this new method in tree peony and the applicability of the LTR sequences based markers was validated by further SSAP analysis. The results showed that the new method is simple, of low-cost, and highly efficient, which is just conducted by three rounds of PCR and does not need any restriction enzymes and adapters, much less the hybridizations. This new method is rapid, economical, and cost- and time-saving, which could be easily used to isolate LTR sequences of RTNs.

Electrochemical Oxidative Esterification of Thiophenols: Efficient Access to Sulfinic Esters

2020 ◽  
Vol 17 (7) ◽  
pp. 540-547
Author(s):  
Chun-Hui Yang ◽  
Cheng Wu ◽  
Jun-Ming Zhang ◽  
Xiang-Zhang Tao ◽  
Jun Xu ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Efficient Method ◽  
High Efficiency ◽  
Building Blocks ◽  
Constant Current ◽  
Good Efficiency ◽  
Oxidative Esterification ◽  
Efficient Access ◽  
New Applications ◽  
Sulfinic Esters

Background: The sulfinic esters are important and useful building blocks in organic synthesis. Objective: The aim of this study was to develop a simple and efficient method for the synthesis of sulfinic esters. Materials and Methods: Constant current electrolysis from thiols and alcohols was selected as the method for the synthesis of sulfinic esters. Results and Discussion: A novel electrochemical method for the synthesis of sulfinic esters from thiophenols and alcohols has been developed. Up to 27 examples of sulfinic esters have been synthesized using the current methods. This protocol shows good functional group tolerance as well as high efficiency. In addition, this protocol can be easily scaled up with good efficiency. Notably, heterocycle-containing substrates, including pyridine, thiophene, and benzothiazole, gave the desired products in good yields. A plausible reaction mechanism is proposed. Conclusion: This research not only provides a green and efficient method for the synthesis of sulfinic esters but also shows new applications of electrochemistry in organic synthesis. It is considered that this green and efficient synthetic protocol used to prepare sulfinic esters will have good applications in the future.

An uncoordinatedly tertiary nitrogen based tricarboxylate Calcium network with Lewis acid-base dual catalytic sites for cyanosilylation of aldehydes

2020 ◽  
Author(s):  
Xian-Ming Zhang ◽  
Ying-Xia Wang ◽  
Hui-Min Wang ◽  
Pan Meng ◽  
Dong-Xia Song ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Efficient Method ◽  
High Efficiency ◽  
Acid Base ◽  
Catalytic Sites ◽  
Tertiary Nitrogen

The design and utilization of dual sites for synergistic catalysts has been recognised as an efficient method towards high-efficiency catalysis in the cyanosilylation of aldehydes, which gives the key intermediates...

A New Method for Railway Fastener Detection Using the Symmetrical Image and Its EA-HOG Feature

2019 ◽  
Vol 34 (02) ◽  
pp. 2055006
Author(s):  
Jiajia Liu ◽  
Jianying Yuan ◽  
Yongfang Jia
Keyword(s):  
Computer Vision ◽  
Sparse Representation ◽  
Efficient Method ◽  
Important Task ◽  
New Method ◽  
Automatic Inspection ◽  
Test Image ◽  
Recognition Result ◽  
The Status ◽  
Railway Operation

Railway fastener recognition and detection is an important task for railway operation safety. However, the current automatic inspection methods based on computer vision can effectively detect the intact or completely missing fasteners, but they have weaker ability to recognize the partially worn ones. In our method, we exploit the EA-HOG feature fastener image, generate two symmetrical images of original test image and turn the detection of the original test image into the detection of two symmetrical images, then integrate the two recognition results of symmetrical image to reach exact recognition of original test image. The potential advantages of the proposed method are as follows: First, we propose a simple yet efficient method to extract the fastener edge, as well as the EA-HOG feature of the fastener image. Second, the symmetry images indeed reflect some possible appearance of the fastener image which are not shown in the original images, these changes are helpful for us to judge the status of the symmetry samples based on the improved sparse representation algorithm and then obtain an exact judgment of the original test image by combining the two corresponding judgments of its symmetry images. The experiment results show that the proposed approach achieves a rather high recognition result and meets the demand of railway fastener detection.

Design of a Retrovirus-Derived Vector for Expression and Transduction of Exogenous Genes in Mammalian Cells

1983 ◽  
Vol 3 (6) ◽  
pp. 1123-1132
Author(s):  
Archibald S. Perkins ◽  
Paul T. Kirschmeier ◽  
Sebastiano Gattoni-Celli ◽  
I. Bernard Weinstein
Keyword(s):  
Mammalian Cells ◽  
High Efficiency ◽  
Leukemia Virus ◽  
Restriction Enzymes ◽  
Virus Genome ◽  
Opposite Polarity ◽  
High Yield ◽  
Animal Cells ◽  
Murine Sarcoma Virus ◽  
Sarcoma Virus

We have developed a transfection vector for animal cells that contains long terminal repeat (LTR) sequences to promote expression. Plasmid p101/101, a derivative of plasmid pBR322 containing the complete Moloney murine sarcoma virus genome, was cut with restriction enzymes and religated so that both the 5′ and 3′ LTRs were retained and all but about 700 base pairs of the intervening viral sequences were removed. To test this vector, the Escherichia coli gene gpt was cloned into a unique Pst I site, between the two LTRs, with guanine and cytosine tailing, a method that can be generalized for insertion of any DNA segment into this vector. When DNA from recombinant plasmids in which the gpt gene was inserted in the same transcriptional polarity as the LTR sequences was transfected onto murine or rat fibroblast cultures, we obtained a high yield of Gpt + colonies. However, plasmid constructs with the gpt gene in the opposite polarity were virtually devoid of activity. With gpt in the proper orientation, restriction enzyme cuts within the LTRs or between the 5′ LTR and the gpt gene reduced transfection by more than 98%, whereas a cut between the gpt gene and the 3′ LTR gave an 80% reduction in activity. Thus, both 5′ and 3′ LTR sequences are essential for optimal gpt expression, although the 5′ LTR appears to play a more important role. When the LTR- gpt plasmid was transfected onto murine leukemia virus-infected mouse fibroblasts, we obtained evidence that RNA copies became pseudotyped into viral particles which could transfer the Gpt + phenotype into rodent cells with extremely high efficiency. This vector should prove useful for high-efficiency transduction of a variety of genes in mammalian cells.

Design of high-efficiency Hybrid Power Amplifier with concurrent F&F−1 class operations for 5G application

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Meisam Tahmasbi ◽  
Farhad Razaghian ◽  
Sobhan Roshani
Keyword(s):  
Power Amplifier ◽  
High Efficiency ◽  
New Method ◽  
Power Added Efficiency ◽  
Hybrid Power ◽  
Novel Structure ◽  
Mode A

Abstract This paper presents a novel structure of Hybrid Power Amplifier (HPA) to operate in two arbitrary classes of operation at two desirable frequencies. The proposed HPA is designed in concurrent F&F−1 classes, simultaneously for 5G application. Presented HPA can solve the harmonics interference problem for concurrent F and F−1 classes and also for any arbitrary class of operation in desired frequencies. The designed HPA operates at 1.5 GHz frequency in the F class mode, while operates at 2.1 GHz frequency in the F−1 class mode. A new method is presented by using two diplexers to provide two paths for signal in different frequencies. Two parallel paths are used at the output of the HPA circuit, so the proposed HPA can operate at two classes. Two diplexers are used in the HPA to make proper isolation between the designed paths. In design of the proposed HPA, according to the utilized diplexers, the amplifier can operate between two arbitrary classes of operation at desired frequencies without any specific switch. The measured drain efficiency (DE) and power added efficiency (PAE) parameters are 57 and 51%, respectively at 2.1 GHz, while measured DE and PAE are 64 and 54%, respectively at 1.5 GHz.

Multivariate Constrained GNSS Real-time Full Attitude Determination Based on Attitude Domain Search

2018 ◽  
Vol 72 (2) ◽  
pp. 483-502
Author(s):  
Hongtao Wu ◽  
Xiubin Zhao ◽  
Chunlei Pang ◽  
Liang Zhang ◽  
Bo Feng
Keyword(s):  
Objective Function ◽  
Success Rate ◽  
High Efficiency ◽  
Attitude Determination ◽  
A Priori ◽  
Three Dimensional ◽  
Satellite System ◽  
New Method ◽  
Lambda Method ◽  
Attitude Angle

A priori attitude information can improve the success rate and reliability of Global Navigation Satellite System (GNSS) multi-antennae attitude determination. However, a priori attitude information is nonlinear, and integrating a priori information into the objective function rigorously will increase the complexity of an ambiguity domain search, such as the Multivariate Constrained-Least-squares Ambiguity Decorrelation Adjustment (MC-LAMBDA) method. In this paper, a new method based on attitude domain search is presented to make use of the a priori attitude angle information with high efficiency. First, the a priori information of pitch and roll is integrated into the search process to derive the analytic search step for attitude angle, and the integer candidates are determined by traversal search in the three-dimensional attitude domain. Then, the objective function is parameterised with Euler angles, and a non-iterative approximate method is utilised to simplify the iterative computation in calculating objective function values. Experimental results reveal that compared to the MC-LAMBDA method, our new method has the same success rate and reliability, but higher efficiency in making use of a priori attitude information.

The Group Keyword Management Method of the Heterogeneous WSN Based on Topology

2013 ◽  
Vol 798-799 ◽  
pp. 480-483
Author(s):  
Tao Ma ◽  
Juan Chen
Keyword(s):  
Wireless Sensor Network ◽  
Sensor Network ◽  
High Efficiency ◽  
New Method ◽  
Wireless Sensor ◽  
Batch Method ◽  
Heterogeneous Wireless Sensor Network ◽  
Management Method

The new method used the node to make up the keyword management tree. The keyword management tree was optimized with renewing the group keyword. In the meanwhile, the use of father nodes and the processing batch method improved the keyword renewing efficiency. The analysis result of theory shows that the method is a high efficiency and extendible group keyword management method which used in the heterogeneous wireless sensor network.

scholarly journals A Power Amplifier with Large High-Efficiency Range for 5G Communication

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5581
Author(s):  
Zhiwei Zhang ◽  
Zhiqun Cheng ◽  
Guohua Liu
Keyword(s):  
Output Power ◽  
Design Process ◽  
Power Amplifier ◽  
High Efficiency ◽  
New Method ◽  
Saturated Output Power ◽  
Doherty Power Amplifier ◽  
5G Communication

This paper presents a new method to design a Doherty power amplifier (DPA) with a large, high-efficiency range for 5G communication. This is through analyzing the drain-to-source capacitance (CDS) of DPAs, and adopting appropriate impedance of the peak device. A closed design process is proposed, to design the extended efficiency range DPA based on derived theories. For validation, a DPA with large efficiency range was designed and fabricated by using two equal devices. The measured results showed that the saturated output power was between 43.4 dBm and 43.7 dBm in the target band. Around 70% saturated drain efficiency is obtained with a gain of greater than 11 dB. Moreover, the obtained drain efficiency is larger than 50% at the 10 dB power back-off, when operating at 3.5 GHz. These superior performances illustrate that the implemented DPA can be applied well in 5G communication.

scholarly journals Bagged Tree Based Frame-Wise Beforehand Prediction Approach for HEVC Intra-Coding Unit Partitioning

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1523
Author(s):  
Yixiao Li ◽  
Lixiang Li ◽  
Yuan Fang ◽  
Haipeng Peng ◽  
Yixian Yang
Keyword(s):  
High Efficiency ◽  
High Efficiency Video Coding ◽  
Time Saving ◽  
Intra Coding ◽  
Fast Approach ◽  
Brute Force Approach ◽  
Adaptive Threshold Determination ◽  
Rate Loss ◽  
Prediction Approach ◽  
Coding Unit

High Efficiency Video Coding (HEVC) has achieved about 50% bit-rates saving compared with its predecessor H.264 standard, while the encoding complexity increases dramatically. Due to the introduction of more flexible partition structures and more optional prediction directions, HEVC takes a brute force approach to find the optimal partitioning result which is much more time consuming. Therefore, this paper proposes a bagged trees based fast approach (BTFA) and focuses on the coding unit (CU) size decision for HEVC intra-coding. First, several key features of a target CU are extracted for three-output classifiers. Then, to avoid feature extraction and prediction time over head, our approach is designed frame-wisely, and the procedure is applied parallel with the encoding process. Using the adaptive threshold determination algorithm, our approach achieves 42.04% time saving with negligible 0.92% Bit-Distortion (BD)-rate loss. Furthermore, in order to calculate the optimal thresholds to balance BD-rate loss and complexity reduction, the neural network based mathematical fitting is added to BTFA, which is called the advanced bagged trees based fast approach (ABTFA). Finally, experimental results show that ABTFA achieves 47.87% time saving with only 0.96% BD-rate loss, which outperforms other state-of-the-art approaches.

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