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Consequences of Non-Uniformity in the Stoichiometry of Component Fractions within One and Two Loops Models of α-Helical Peptides
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作者 Walter F. Schmidt Cathleen J. Hapeman +1 位作者 James Wachira Clayton G. Thomas 《Journal of Biophysical Chemistry》 2014年第4期125-133,共9页
A 3-D electrostatic density map generated using the Wavefront Topology System and Finite Element Method clearly demonstrates the non-uniformity and periodicity present in even a single loop of an α-helix. The four di... A 3-D electrostatic density map generated using the Wavefront Topology System and Finite Element Method clearly demonstrates the non-uniformity and periodicity present in even a single loop of an α-helix. The four dihedral angles (N-C*-C-N, C*-C-N-C*, and C-N-C*-C) fully define a helical shape independent of its length: the three dihedral angles, φ = -33.5°, ω = 177.3°, and Ψ = -69.4°, generate the precise (and identical) redundancy in a one loop (or longer) α-helical shape (pitch = 1.59 /residue;r = 2.25 ). Nevertheless the pattern of dihedral angles within an 11 and a 22-peptide backbone atom sequence cannot be distributed evenly because the stoichiometry in fraction of four atoms never divides evenly into 11 or 22 backbone atoms. Thus, three sequential sets of 11 backbone atoms in an α-helix will have a discretely different chemical formula and correspondingly different combinations of molecular forces depending upon the assigned starting atom in an 11-step sequence. We propose that the unit cell of one loop of an α-helix occurs in the peptide backbone sequence C-(N-C*-C)3-N which contains an odd number of C* plus even number of amide groups. A two-loop pattern (C*-C-N)7-C* contains an even number of C* atoms plus an odd number of amide groups. Dividing the two-loop pattern into two equal lengths, one fraction will have an extra half amide (N-H) and the other fraction will have an extra half amide C=O, i.e., the stoichiometry of each half will be different. Also, since the length of N-C*-C-N, C*-C-N-C*, and C-N-C*-C are unequal, the summation of the number of each in any fraction of n loops of an α-helix in sequence will always have unequal length, depending upon the starting atom (N, C*, or C). 展开更多
关键词 Pattern Recognition Α-HELIX Dihedral Angle Patterns Peptide BACKBONE sequence Molecular Orbital Theory Electrostatic Density gradient Wavefront Topology System Finite Element Method
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Resource Efficient Hardware Implementation for Real-Time Traffic Sign Recognition
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作者 Huai-Mao Weng Ching-Te Chiu 《Journal of Transportation Technologies》 2018年第3期209-231,共23页
Traffic sign recognition (TSR, or Road Sign Recognition, RSR) is one of the Advanced Driver Assistance System (ADAS) devices in modern cars. To concern the most important issues, which are real-time and resource effic... Traffic sign recognition (TSR, or Road Sign Recognition, RSR) is one of the Advanced Driver Assistance System (ADAS) devices in modern cars. To concern the most important issues, which are real-time and resource efficiency, we propose a high efficiency hardware implementation for TSR. We divide the TSR procedure into two stages, detection and recognition. In the detection stage, under the assumption that most German traffic signs have red or blue colors with circle, triangle or rectangle shapes, we use Normalized RGB color transform and Single-Pass Connected Component Labeling (CCL) to find the potential traffic signs efficiently. For Single-Pass CCL, our contribution is to eliminate the “merge-stack” operations by recording connected relations of region in the scan phase and updating the labels in the iterating phase. In the recognition stage, the Histogram of Oriented Gradient (HOG) is used to generate the descriptor of the signs, and we classify the signs with Support Vector Machine (SVM). In the HOG module, we analyze the required minimum bits under different recognition rate. The proposed method achieves 96.61% detection rate and 90.85% recognition rate while testing with the GTSDB dataset. Our hardware implementation reduces the storage of CCL and simplifies the HOG computation. Main CCL storage size is reduced by 20% comparing to the most advanced design under typical condition. By using TSMC 90 nm technology, the proposed design operates at 105 MHz clock rate and processes in 135 fps with the image size of 1360 × 800. The chip size is about 1 mm2 and the power consumption is close to 8 mW. Therefore, this work is resource efficient and achieves real-time requirement. 展开更多
关键词 TRAFFIC SIGN Recognition Advanced Driver ASSISTANCE System REAL-TIME Processing Color Segmentation Connected Component Analysis Histo-gram of Oriented gradient Support Vector Machine German TRAFFIC SIGN Detection BENCHMARK CMOS ASIC VLSI
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用电子散斑法对纯镍薄片弯曲变形的测量 被引量:11
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作者 郭香华 方岱宁 李喜德 《力学与实践》 CSCD 北大核心 2005年第2期22-25,21,共5页
由于建立的电子散斑法有位移测量精度高、量程大的特点,且自制的力传感器灵敏度高、量程相 对较大,从而保证了本实验中镍片在三点弯中的反应被全程、精确地记录下来.基于时间序列的电子散斑法, 测出了10-100μm不同厚度的纯镍薄片在三... 由于建立的电子散斑法有位移测量精度高、量程大的特点,且自制的力传感器灵敏度高、量程相 对较大,从而保证了本实验中镍片在三点弯中的反应被全程、精确地记录下来.基于时间序列的电子散斑法, 测出了10-100μm不同厚度的纯镍薄片在三点弯下的载荷-位移曲线,其中包括弹性部分以及进入塑性屈服 两个阶段,据此可以推出不同厚度镍片的三点弯刚度.实验表明镍片的抗弯刚度受其厚度的影响很大,尤其在 薄片厚度较小时表现得更为明显,即表现出明显的尺度效应. 展开更多
关键词 -线
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基于UML面向方面动态行为建模 被引量:2
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作者 展先俊 吴海涛 《计算机与数字工程》 2010年第12期70-73,共4页
面向方面动态行为建模在设计阶段实现了横切关注点的分离,能更好的解决编程阶段代码的纠缠和散射问题,从而提高了软件的可重用性,可维护性,可跟踪性。由于面向对象的动态行为建模通常由标准的面向对象建模语言UML表示,所以文章在UML的... 面向方面动态行为建模在设计阶段实现了横切关注点的分离,能更好的解决编程阶段代码的纠缠和散射问题,从而提高了软件的可重用性,可维护性,可跟踪性。由于面向对象的动态行为建模通常由标准的面向对象建模语言UML表示,所以文章在UML的基础上,建立面向方面横切关注点的动态模型。 展开更多
关键词 UML Behavior Modeling
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A Hybrid Conjugate Gradient Algorithm for Solving Relative Orientation of Big Rotation Angle Stereo Pair 被引量:3
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作者 Jiatian LI Congcong WANG +5 位作者 Chenglin JIA Yiru NIU Yu WANG Wenjing ZHANG Huajing WU Jian LI 《Journal of Geodesy and Geoinformation Science》 2020年第2期62-70,共9页
The fast convergence without initial value dependence is the key to solving large angle relative orientation.Therefore,a hybrid conjugate gradient algorithm is proposed in this paper.The concrete process is:①stochast... The fast convergence without initial value dependence is the key to solving large angle relative orientation.Therefore,a hybrid conjugate gradient algorithm is proposed in this paper.The concrete process is:①stochastic hill climbing(SHC)algorithm is used to make a random disturbance to the given initial value of the relative orientation element,and the new value to guarantee the optimization direction is generated.②In local optimization,a super-linear convergent conjugate gradient method is used to replace the steepest descent method in relative orientation to improve its convergence rate.③The global convergence condition is that the calculation error is less than the prescribed limit error.The comparison experiment shows that the method proposed in this paper is independent of the initial value,and has higher accuracy and fewer iterations. 展开更多
关键词 relative orientation big rotation angle global convergence stochastic hill climbing conjugate gradient algorithm
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Composition and Diversity of Soil Bacterial Communities along an Environmental Gradient in the Sudano-Sahelian Region of Senegal
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作者 Souleymane B. D. Diatta Laure N. Tall +2 位作者 Yacine B. Ndour Mbacke Sembene Komi Assigbetsé 《Open Journal of Soil Science》 2020年第2期58-89,共32页
The soils of the semi-arid Sudano-Sahelian region of West Africa have been identified as being highly vulnerable to soil degradation with impacts on their capacity to provide goods and services in which soil microorga... The soils of the semi-arid Sudano-Sahelian region of West Africa have been identified as being highly vulnerable to soil degradation with impacts on their capacity to provide goods and services in which soil microorganisms participate. Unfortunately, soil microbial diversity from this semi-arid region with high rainfall variability remains largely unexplored. The aim of the present study was to characterize the diversity and composition of the soil bacterial communities and to identify factors involved in their spatial distribution along an environmental gradient in Senegal. Samples were collected from non-anthropogenic sites across four pedoclimatic zones. Bacterial communities were characterized using next-generation sequencing and soil physico-chemical parameters were determined. Our results showed that Firmicutes, Actinobacteria, Proteobacteria, Chloroflexi, Gemmatimonadetes, Acidobacteria, and Verrucomicrobia phyla were predominant in the soils of the region. Bacterial α-diversity was stable along the environmental gradient whereas β-diversity highlighted significant changes in the composition of the soil bacterial community. Changes were driven by shifts in the relative abundance of OTUs belonging mainly to the genus Bacillus, Conexibacter, Kaistobacter, Solirubrobacter, Ktedonobacter, Sphingomonas, Microvirga, Rubrobacter and Pelobacter. Soil properties like pH, soil moisture and clay content were the environmental parameters identified as drivers of the composition of the bacterial communities in the semi-arid Sudano-Sahelian region of Senegal (West Africa). 展开更多
关键词 SOIL BACTERIAL DIVERSITY Sudano-Sahelian Pedoclimatic gradient Next-Generation SEQUENCING
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Near-surface Geothermal Gradient Observation and Geothermal Analyses in the Xianshuihe Fault Zone,Eastern Tibetan Plateau 被引量:8
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作者 LIU Qianqian SHI Yanan +4 位作者 WEI Dongping HAN Peng CHEN Shunyun LIU Peixun LIU Liqiang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第2期414-428,共15页
The Xianshuihe fault(XSHF) zone, characterized by intense tectonic activity, is located at the southwest boundary of the Bayan Har block, where several major earthquakes have occurred, including the 2008 Wenchuan an... The Xianshuihe fault(XSHF) zone, characterized by intense tectonic activity, is located at the southwest boundary of the Bayan Har block, where several major earthquakes have occurred, including the 2008 Wenchuan and the 2013 Lushan earthquakes. This study analysed underground temperature sequence data for four years at seven measuring points at different depths(maximum depth: 18.9 m) in the southeastern section of the XSHF zone. High-frequency atmospheric noise was removed from the temperature sequences to obtain relatively stable temperature fields and heat fluxes near the measurement points. Our measurements show that the surrounding bedrock at(the seven stations distributed in the fault zone) had heat flux values range from-41.0 to 206 m W/m^2, with a median value of 54.3 m W/m^2. The results indicate a low heat flux in the northern section of DaofuKangting and a relatively high heat flux in the southern section of Kangting, which is consistent with the temperature distributions of the hot springs near the fault. Furthermore, our results suggest that the heat transfer in this field results primarily from stable underground heat conduction. In addition, the underground hydrothermal activity is also an obvious factor controlling the geothermal gradient. 展开更多
关键词 temperature sequence records geothermal gradient heat flow heat flux Xianshuihe fault zone Tibet Plateau Proto-Tethys
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Decision tree and deep learning based probabilistic model for character recognition 被引量:6
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作者 A.K.Sampath Dr.N.Gomathi 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第12期2862-2876,共15页
One of the most important methods that finds usefulness in various applications, such as searching historical manuscripts, forensic search, bank check reading, mail sorting, book and handwritten notes transcription, i... One of the most important methods that finds usefulness in various applications, such as searching historical manuscripts, forensic search, bank check reading, mail sorting, book and handwritten notes transcription, is handwritten character recognition. The common issues in the character recognition are often due to different writing styles, orientation angle, size variation(regarding length and height), etc. This study presents a classification model using a hybrid classifier for the character recognition by combining holoentropy enabled decision tree(HDT) and deep neural network(DNN). In feature extraction, the local gradient features that include histogram oriented gabor feature and grid level feature, and grey level co-occurrence matrix(GLCM) features are extracted. Then, the extracted features are concatenated to encode shape, color, texture, local and statistical information, for the recognition of characters in the image by applying the extracted features to the hybrid classifier. In the experimental analysis, recognition accuracy of 96% is achieved. Thus, it can be suggested that the proposed model intends to provide more accurate character recognition rate compared to that of character recognition techniques used in the literature. 展开更多
关键词 GREY level CO-OCCURRENCE matrix FEATURE HISTOGRAM oriented GABOR gradient FEATURE hybrid CLASSIFIER holoentropy enabled decision tree CLASSIFIER
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Novel Methods in the Study of the Breast Cancer Genome: Towards a Better Understanding of the Disease of Breast Cancer
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作者 Jian Li Xue Lin +2 位作者 Nils Brünner Huanming Yang Lars Bolund 《Journal of Cancer Therapy》 2012年第5期797-809,共13页
Rapidly developing sequencing technologies and bioinformatic approacheshave provided us with an unprecedented instrument allowing for an unbiased and exhaustive characterization of the cancer genome in genetic, epigen... Rapidly developing sequencing technologies and bioinformatic approacheshave provided us with an unprecedented instrument allowing for an unbiased and exhaustive characterization of the cancer genome in genetic, epigenetic and transcriptomic dimensions. This review introduces recent excitingfindings and new methodologies in genomic breast cancer research. With this development, cancer genome research will illuminate new delicate interactionsbetween molecular networks and thereby unravelthe underlying biological mechanisms for cancer initiation and progression. It also holds promise for providing a molecular clock for the estimation of the temporal processes of tumorigenesis. These methods in combination with single cell sequencing will make it possible to construct a family tree elucidating the evolutionary lineage relationships between cell populations at single-cell resolution. The anticipatedrapid progress in genomic breast cancer research should lead to anenhanced understanding of breast cancer biology andguide us towardsnovel ways to ultimatelyprevent and cure breast cancer. 展开更多
关键词 BREAST Cancer GENOME Massively Parallel SEQUENCING Pathway-Oriented Analysis MITOCHONDRIAL GENOME Temporal Order of ABERRATIONS Single Cell SEQUENCING MICROBIOME
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Product Image Classification Based on Fusion Features
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作者 杨晓慧 刘静静 杨利军 《Chinese Quarterly Journal of Mathematics》 2015年第3期429-441,共13页
Two key challenges raised by a product images classification system are classification precision and classification time. In some categories, classification precision of the latest techniques, in the product images cl... Two key challenges raised by a product images classification system are classification precision and classification time. In some categories, classification precision of the latest techniques, in the product images classification system, is still low. In this paper, we propose a local texture descriptor termed fan refined local binary pattern, which captures more detailed information by integrating the spatial distribution into the local binary pattern feature. We compare our approach with different methods on a subset of product images on Amazon/e Bay and parts of PI100 and experimental results have demonstrated that our proposed approach is superior to the current existing methods. The highest classification precision is increased by 21% and the average classification time is reduced by 2/3. 展开更多
关键词 product image CLASSIFICATION FAN refined local binary pattern(FRLBP) PYRAMID HISTOGRAM of orientated gradients(PHOG) FUSION FEATURES
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Improving the Transmission Security of Vein Images Using a Bezier Curve and Long Short-Term Memory
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作者 Ahmed H.Alhadethi Ikram Smaoui +1 位作者 Ahmed Fakhfakh Saad M.Darwish 《Computers, Materials & Continua》 SCIE EI 2024年第6期4825-4844,共20页
The act of transmitting photos via the Internet has become a routine and significant activity.Enhancing the security measures to safeguard these images from counterfeiting and modifications is a critical domain that c... The act of transmitting photos via the Internet has become a routine and significant activity.Enhancing the security measures to safeguard these images from counterfeiting and modifications is a critical domain that can still be further enhanced.This study presents a system that employs a range of approaches and algorithms to ensure the security of transmitted venous images.The main goal of this work is to create a very effective system for compressing individual biometrics in order to improve the overall accuracy and security of digital photographs by means of image compression.This paper introduces a content-based image authentication mechanism that is suitable for usage across an untrusted network and resistant to data loss during transmission.By employing scale attributes and a key-dependent parametric Long Short-Term Memory(LSTM),it is feasible to improve the resilience of digital signatures against image deterioration and strengthen their security against malicious actions.Furthermore,the successful implementation of transmitting biometric data in a compressed format over a wireless network has been accomplished.For applications involving the transmission and sharing of images across a network.The suggested technique utilizes the scalability of a structural digital signature to attain a satisfactory equilibrium between security and picture transfer.An effective adaptive compression strategy was created to lengthen the overall lifetime of the network by sharing the processing of responsibilities.This scheme ensures a large reduction in computational and energy requirements while minimizing image quality loss.This approach employs multi-scale characteristics to improve the resistance of signatures against image deterioration.The proposed system attained a Gaussian noise value of 98%and a rotation accuracy surpassing 99%. 展开更多
关键词 Image transmission image compression text hiding Bezier curve Histogram of Oriented gradients(HOG) LSTM image enhancement Gaussian noise ROTATION
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改进灰狼算法优化GBDT在PM_(2.5)预测中的应用 被引量:2
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作者 江雨燕 傅杰 +2 位作者 甘如美江 孙雨辰 王付宇 《安全与环境学报》 CAS CSCD 北大核心 2024年第4期1569-1580,共12页
针对灰狼算法易陷入局部最优解和全局搜索能力不足的问题,通过霍尔顿序列(Halton Sequence)搜索算法初始化狼群位置,避免灰狼算法陷入局部最优解和重复运算;引入莱维飞行和随机游动策略对灰狼算法的寻优过程进行优化,以增加算法的全局... 针对灰狼算法易陷入局部最优解和全局搜索能力不足的问题,通过霍尔顿序列(Halton Sequence)搜索算法初始化狼群位置,避免灰狼算法陷入局部最优解和重复运算;引入莱维飞行和随机游动策略对灰狼算法的寻优过程进行优化,以增加算法的全局搜索能力;利用粒子群算法模拟灰狼种群得出的最佳适应度以用于惩罚项改进灰狼算法中的头狼更新策略。使用改进算法优化的梯度提升树(Gradient Boosting Decision Trees,GBDT)模型对北京市大气污染物监测数据中PM_(2.5)质量浓度进行预测,采用3种评估函数对各模型以及混合模型预测效果得分进行评估。结果显示,本文改进的灰狼算法对梯度提升树的优化效果优于其他算法,均方根误差E RMS为6.65μg/m^(3),平均绝对值误差E MA为3.20μg/m^(3),拟合优度(R^(2))为99%,比传统灰狼算法优化结果的均方根误差减少了19.19μg/m^(3),平均绝对值误差降低了10.03μg/m^(3),拟合优度增加了9百分点;与霍尔顿序列和莱维飞行改进的(Levy Flight-Halton Sequence,LHGWO)相比,改进的灰狼算法预测得分的均方根误差降低了10.39μg/m^(3),平均绝对值误差减小了6.71μg/m^(3),拟合优度提高了5百分点。研究表明了预测模型优化的有效性,为未来城市改善空气质量提供了科学依据和技术支持。 展开更多
关键词 PM_(2.5) (GWO) (GBDT) (Levy) (Halton sequence) (PSO)
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Mechanical properties of electroformed copper layers with gradient microstructure 被引量:2
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作者 Qiang Liao Li-qun Zhu Hui-cong Liu Wei-ping Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2010年第1期69-74,共6页
The electroformed copper layer with gradient microstructure was prepared using the ultrasonic technique. The microstructure of the electroformed copper layer was observed by using an optical microscope (OM) and a sc... The electroformed copper layer with gradient microstructure was prepared using the ultrasonic technique. The microstructure of the electroformed copper layer was observed by using an optical microscope (OM) and a scanning electron microscope (SEM). The preferred orientations of the layer were characterized by X-ray diffraction (XRD). The mechanical properties were evaluated with a Vicker's hardness tester and a tensile tester. It is found the gradient microstructure consists of two main parts: the outer part (faraway substrate) with columnar crystals and the inner part (nearby substrate) with equiaxed grains. The Cu-(220) preferred orientation increases with the increasing thickness of the copper layer. The test results show that the microhardness of the electroformed copper layer decreases with increasing grain size along the growth direction and presents a gradient distribution. The tensile strength of the outer part of the electroformed copper layer is higher than that of the inner part but at the cost of ductility. Meanwhile, the integral mechanical properties of the electroformed copper with gradient microstrucmre are significantly improved in comparison with the pure copper deposit. 展开更多
关键词 ELECTROFORMING copper layer gradient rnicrostructure mechanical properties preferred orientation
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强杂波中双波段目标检测新算法 被引量:4
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作者 宗思光 王江安 马治国 《红外技术》 CSCD 北大核心 2005年第1期57-61,共5页
对海空背景下的电视和3-5μm红外目标提出了一种采用多向梯度表决融合的检测方法:依据 背景图像中点目标的奇异特性,得到图像的多向剃度检测结果,并进行表决融合。通过实测的电视和 红外图像仿真,结果表明,采用"and"判决规则... 对海空背景下的电视和3-5μm红外目标提出了一种采用多向梯度表决融合的检测方法:依据 背景图像中点目标的奇异特性,得到图像的多向剃度检测结果,并进行表决融合。通过实测的电视和 红外图像仿真,结果表明,采用"and"判决规则的多向梯度表决融合的检测算法消除了云层、海浪、 海天线等背景干扰,在实现高检测概率的同时,可以达到较低的虚警概率。该算法特别适用于低帧率 的红外警戒系统,可检测信杂比为1的点目标。 展开更多
关键词 线
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A Service Composition Approach Based on Sequence Mining for Migrating E-learning Legacy System to SOA 被引量:1
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作者 Zhuo Zhang Dong-Dai Zhou +1 位作者 Hong-Ji Yang Shao-Chun Zhong 《International Journal of Automation and computing》 EI 2010年第4期584-595,共12页
With the fast development of business logic and information technology, today's best solutions are tomorrow's legacy systems. In China, the situation in the education domain follows the same path. Currently, there e... With the fast development of business logic and information technology, today's best solutions are tomorrow's legacy systems. In China, the situation in the education domain follows the same path. Currently, there exists a number of e-learning legacy assets with accumulated practical business experience, such as program resource, usage behaviour data resource, and so on. In order to use these legacy assets adequately and efficiently, we should not only utilize the explicit assets but also discover the hidden assets. The usage behaviour data resource is the set of practical operation sequences requested by all users. The hidden patterns in this data resource will provide users' practical experiences, which can benefit the service composition in service-oriented architecture (SOA) migration. Namely, these discovered patterns will be the candidate composite services (coarse-grained) in SOA systems. Although data mining techniques have been used for software engineering tasks, little is known about how they can be used for service composition of migrating an e-learning legacy system (MELS) to SOA. In this paper, we propose a service composition approach based on sequence mining techniques for MELS. Composite services found by this approach will be the complementation of business logic analysis results of MELS. The core of this approach is to develop an appropriate sequence mining algorithm for mining related data collected from an e-learning legacy system. According to the features of execution trace data on usage behaviour from this e-learning legacy system and needs of further pattern analysis, we propose a sequential mining algorithm to mine this kind of data of tile legacy system. For validation, this approach has been applied to the corresponding real data, which was collected from the e-learning legacy system; meanwhile, some investigation questionnaires were set up to collect satisfaction data. The investigation result is 90% the same with the result obtained through our approach. 展开更多
关键词 Service composition E-LEARNING sequence mining algorithm service-oriented architecture SOA legacy system
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磁共振FLAIR序列表现阴性的局灶性皮质发育不良病灶检测的研究进展 被引量:1
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作者 俱京涛 陈楠 《磁共振成像》 CAS CSCD 北大核心 2022年第7期164-166,170,共4页
局灶性皮质发育不良(focal cortical dysplasia,FCD)是导致药物难治性癫痫的常见原因之一,Ⅰ型在FCD中的占比为38.3%,而Ⅱ型占比为61.7%。手术是治疗FCD的有效方式。术前发现病灶并精准定位是决定手术方式及预后的重要因素。目前对于FC... 局灶性皮质发育不良(focal cortical dysplasia,FCD)是导致药物难治性癫痫的常见原因之一,Ⅰ型在FCD中的占比为38.3%,而Ⅱ型占比为61.7%。手术是治疗FCD的有效方式。术前发现病灶并精准定位是决定手术方式及预后的重要因素。目前对于FCD的诊断主要依赖MRI检查,但是,高达40%的Ⅱ型FCD和85%的Ⅰ型FCD病灶在常规MRI上表现为阴性,给诊断和手术带来极大的难度。随着MRI硬件、软件及后处理技术的发展,极大提高了FCD在常规MRI表现为阴性的检出率(综合诊断增益率为31%),对病灶准确定位、指导手术、降低术后癫痫发作具有重要意义。因此本文就提高常规MRI表现为阴性的FCD检出率的方法进行综述。 展开更多
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柴达木盆地昆特依盐湖可培养嗜盐细菌多样性研究
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作者 马想蓉 马欣 +3 位作者 陈胤勋 龙启福 王嵘 邢江娃 《生物技术通报》 CAS CSCD 北大核心 2024年第7期285-298,共14页
【目的】探究不同富集时间、培养盐度、稀释梯度、培养基等对氯化物型昆特依高盐盐湖可培养嗜盐细菌多样性的影响,确定嗜盐细菌的最佳分离培养条件,挖掘更多的环境嗜盐细菌资源。【方法】从昆特依盐湖中采集水泥混合样本,选取7种培养基... 【目的】探究不同富集时间、培养盐度、稀释梯度、培养基等对氯化物型昆特依高盐盐湖可培养嗜盐细菌多样性的影响,确定嗜盐细菌的最佳分离培养条件,挖掘更多的环境嗜盐细菌资源。【方法】从昆特依盐湖中采集水泥混合样本,选取7种培养基和10%、18% NaCl两个盐度,采用富集培养法、平板稀释涂布法和平板分区划线法分离嗜盐菌;通过16S rRNA基因测序与BLAST序列比对确定菌株系统分类学地位。同时采用免培养Illumina MiSeq高通量测序技术分析昆特依盐湖细菌群落结构多样性特征。【结果】免培养昆特依盐湖样本中共鉴定到细菌39门64纲101目219科703属,其中假单胞菌门(Pseudomonadota)、厚壁菌门(Bacillota)、拟杆菌门(Bacteroidota)和放线菌门(Actinomycetota)为主要的优势菌门。根据菌落的大小、形态、颜色、光泽度、透明度、质地、隆起状态和边缘特征等,共分离出436株嗜盐菌,隶属于3门3纲6目9科28属77种,其中16株可能为潜在新种。3门为厚壁菌门(Bacillota)、假单胞菌门(Pseudomonadota)和放线菌门(Actinomycetota),且均为免培养测序结果中的优势菌门。在属水平上,芽孢杆菌属(Bacillus)、盐单胞菌属(Halomonas)、喜盐芽孢杆菌属(Halobacillus)、枝芽孢菌属(Virgibacillus)和卤水杆菌属(Salicola)为优势菌属。肿块芽孢杆菌属(Tuberibacillus)、越南蔷薇菌属(Rossellomorea)和谷氨酸杆菌属(Glutamicibacter)是首次从盐湖中分离得到。18% NaCl分离得到的菌株数量明显少于10% NaCl,且多样性较低,芽孢乳杆菌科(Sporolactobacillaceae)是该条件下分出的特有菌科。7种培养基中,1/2 RCA培养基分离效果最好。最佳富集培养时间为0、7和60 d,最佳样品稀释梯度为10^(-2)和10^(-3)。【结论】从昆特依盐湖中共分离出嗜盐细菌3门3纲6目9科28属77种。应用多种培养基,设置不同盐度、富集培养时间和稀释梯度等可显著提升可培养嗜盐菌的多样性。 展开更多
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寒地特色薄皮甜瓜转录组测序分析 被引量:1
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作者 金荣荣 曹虹 +1 位作者 刘斯斯 盛慧 《北方园艺》 CAS 北大核心 2024年第11期30-34,共5页
以13份薄皮甜瓜为试材,采用转录组测序方法,研究了白粉病抗性相关基因的表达情况,以期获得薄皮甜瓜白粉病抗性相关候选基因。结果表明:上调表达谱中,有21个基因只出现在抗性较好的品种中;下调表达谱中,有42个基因只出现在低抗品种中。G... 以13份薄皮甜瓜为试材,采用转录组测序方法,研究了白粉病抗性相关基因的表达情况,以期获得薄皮甜瓜白粉病抗性相关候选基因。结果表明:上调表达谱中,有21个基因只出现在抗性较好的品种中;下调表达谱中,有42个基因只出现在低抗品种中。GO分析显示,基因产物的活动主要涉及碳-碳裂解酶活性、ADP焦磷酸水解酶活性、肌氨酸氧化酶活性和β-麦芽糖4-α-葡萄糖转移酶活性等。利用KEGG Pathway分析了解基因的生物学功能发现,上调和下调基因多集中于植物昼夜节律调节、鞘糖脂生物合成通路硫胺素代谢和细胞的包吞作用等。结合前期GWAS的分析结果,选定MELO3C033293.2和MELO3C006706.2等作为寒地薄皮甜瓜白粉病抗性相关候选基因,进行下一步定量表达分析。 展开更多
关键词 GO KEGG
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Object-Oriented Database Connectivity for Hand Held Devices
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作者 Vipin Saxena Santosh Kumar 《Journal of Software Engineering and Applications》 2012年第5期314-320,共7页
Due to the lack of representation of an object-oriented database on hand-held devices, the present work describes an approach to send the information in the form of an object-oriented database on hand-held devices. A ... Due to the lack of representation of an object-oriented database on hand-held devices, the present work describes an approach to send the information in the form of an object-oriented database on hand-held devices. A smart phone is selected as a hand-held device and connectivity between the object-oriented databases has been established by the use of the object-oriented programming language C#.Net. For modeling purpose, Unified Modeling Language (UML) is used to specify a UML Class Model and Sequence diagram. A concept of star schema is also used to represent the object-oriented database. 展开更多
关键词 UML Object orientation Class DIAGRAM sequence DIAGRAM SQL Server Star SCHEMA and C#.NET
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车载序列影像直接相对定向质量 被引量:4
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作者 徐振亮 闫利 +2 位作者 段伟 陈林 刘华 《辽宁工程技术大学学报(自然科学版)》 CAS 北大核心 2013年第3期321-325,共5页
为验证地面大转角、小面幅序列数码影像直接相对定向质量.推导了一套基于SIFT特征匹配的计算机视觉分析方法,解算过程简洁明了.研究结果表明:基于计算机视觉方法能够有效解决大转角影像、特别是车载序列数码影像相对定向中的匹配难题,... 为验证地面大转角、小面幅序列数码影像直接相对定向质量.推导了一套基于SIFT特征匹配的计算机视觉分析方法,解算过程简洁明了.研究结果表明:基于计算机视觉方法能够有效解决大转角影像、特别是车载序列数码影像相对定向中的匹配难题,解算结果比较稳定;从目前的结果来看,直接相对定向质量还不高,但研究方法对室内移动机器人环境感知、无人驾驶等导航领域具有一定的借鉴价值;最后分析了制约其质量的主要原因,为今后分析和提高视觉量测质量提供了一条思路. 展开更多
关键词 姿
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