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891.
Background
The Brain Computer Interfaces (BCI) are devices allowing direct communication between the brain of a user and a machine. This technology can be used by disabled people in order to improve their independence and maximize their capabilities such as finding an object in the environment. Such devices can be realized by the non-invasive measurement of information from the cortex by electroencephalography (EEG).Methods
Our work proposes a novel BCI system that consists of controlling a robot arm based on the user's thought. Four subjects (1 female and 3 males) aged between 20 and 29 years have participated to our experiment. They have been instructed to imagine the execution of movements of the right hand, the left hand, both right and left hands or the movement of the feet depending on the protocol established.EMOTIV EPOC headset was used to record neuronal electrical activities from the subject's scalp, these activities were then sent to the computer for analysis. Feature extraction was performed using the Principal Component Analysis (PCA) method combined with the Fast Fourier transform (FFT) spectrum within the frequency band responsible for sensorimotor rhythms (8 Hz–22 Hz).These features were then fed into a Support Vector Machine (SVM) classifier based on a Radial Base Function (RBF) whose outputs were translated into commands to control the robot arm.Results
The proposed BCI enabled the control of the robot arm in the four directions: right, left, up and down, achieving an averaged accuracy of 85.45% across all the subjects.Conclusion
The results obtained would encourage, with further developments, the use of the proposed BCI to perform more complex tasks such as execution of successive movements or stopping the execution once a searched object is detected. This would provide a useful assistance means for people with motor impairment. 相似文献892.
Present research work investigated the impact of hexane extract of Lantana camara leaves on the survival, survival duration, growth and development of the Dysdercus koenigii. Newly emerged fifth instar nymphs were exposed to nine concentrations viz. 10%, 5%, 2.5%, 1.25% 0.1%, 0.05%, 0.025%, 0.0125% and 0.00625% of the extract by ‘dry film residual method’ for 24 h. The results indicated that the survival and the growth of the nymphs decreased with increasing concentrations of the L. camara extract. The nymphs presented developmental malformation including incomplete moulting followed by death of the moulting nymphs, supernumerary nymphal instars, adults with wing deformities, and adults with exuviae attached to the body. The GC–MS analysis of the extract indicated presence of phytoconstituents with insecticidal activities, and intermediates of the juvenile hormone biosynthetic pathway. It was surmised that these intermediates individually or synergistically influence JH biosynthesis. L. camara extract causes mortality, inhibits growth and development and results in developmental anomalies in the D. koenigii thus indicated its potentials in the ‘integrated pest management’. 相似文献
893.
Mahdi Jalili Tom Gebhardt Olaf Wolkenhauer Ali Salehzadeh-Yazdi 《生物化学与生物物理学报:疾病的分子基础》2018,1864(6):2349-2359
Decoding health and disease phenotypes is one of the fundamental objectives in biomedicine. Whereas high-throughput omics approaches are available, it is evident that any single omics approach might not be adequate to capture the complexity of phenotypes. Therefore, integrated multi-omics approaches have been used to unravel genotype–phenotype relationships such as global regulatory mechanisms and complex metabolic networks in different eukaryotic organisms. Some of the progress and challenges associated with integrated omics studies have been reviewed previously in comprehensive studies. In this work, we highlight and review the progress, challenges and advantages associated with emerging approaches, integrating gene expression and protein-protein interaction networks to unravel network-based functional features. This includes identifying disease related genes, gene prioritization, clustering protein interactions, developing the modules, extract active subnetworks and static protein complexes or dynamic/temporal protein complexes. We also discuss how these approaches contribute to our understanding of the biology of complex traits and diseases. This article is part of a Special Issue entitled: Cardiac adaptations to obesity, diabetes and insulin resistance, edited by Professors Jan F.C. Glatz, Jason R.B. Dyck and Christine Des Rosiers. 相似文献
894.
895.
Fataneh Jafari Setareh Samadi Amin Nowroozi Komail Sadrjavadi Sajad Moradi Mohammad Reza Ashrafi-Kooshk 《Journal of biomolecular structure & dynamics》2018,36(6):1490-1510
In the present research, the binding properties of diazinon (DZN), as an organophosphorus herbicide, to human serum albumin (HSA) were investigated using combination of spectroscopic, electrochemistry, and molecular modeling techniques. Changes in the UV–Vis and FT-IR spectra were observed upon ligand binding along with a significant degree of tryptophan fluorescence quenching on complex formation. The obtained results from spectroscopic and electrochemistry experiments along with the computational studies suggest that DZN binds to residues located in subdomains IIA of HSA with binding constant about 1410.9 M?1 at 300 K. From the thermodynamic parameters calculated according to the van’t Hoff equation, the enthalpy change ΔH° and entropy change ΔS° were found to be ?16.695 and 0.116 KJ/mol K, respectively. The primary binding pattern is determined by hydrophobic interaction and hydrogen binding occurring in so-called site I of HSA. DZN could slightly alter the secondary structure of HSA. All of experimental results are supported by computational techniques such as docking and molecular dynamics simulation using a HSA crystal model. 相似文献
896.
Varsha Bhavnani Swarnendu Kaviraj Priyabrata Panigrahi C.G. Suresh SuneelShekar Yapara 《Journal of biomolecular structure & dynamics》2018,36(11):2845-2861
The eIF2α kinase activity of the heme-regulated inhibitor (HRI) is regulated by heme which makes it a unique member of the family of eIF2α kinases. Since heme concentrations create an equilibrium for the kinase to be active/inactive, it becomes important to study the heme binding effects upon the kinase and understanding its mechanism of functionality. In the present study, we report the thermostability achieved by the catalytic kinase domain of HRI (HRI.CKD) upon ligand (heme) binding. Our CD data demonstrates that the HRI.CKD retains its secondary structure at higher temperatures when it is in ligand bound state. HRI.CKD when incubated with hemin loses its monomeric state and attains a higher order oligomeric form resulting in its stability. The HRI.CKD fails to refold into its native conformation upon mutation of H377A/H381A, thereby confirming the necessity of these His residues for correct folding, stability, and activity of the kinase. Though our in silico study demonstrated these His being the ligand binding sites in the kinase insert region, the spectra-based study did not show significant difference in heme affinity for the wild type and His mutant HRI.CKD. 相似文献
897.
Identification of new potential inhibitors against Hedgehog pathway activator protein Smoothened (SMO) is considered to be of higher importance to improvise the future cancer therapeutics. Different SMO inhibitors/drugs (e.g. Cyclopamine, Vismodegib, Taladegib) used till date are found to be associated with several drug-related resistivity and toxicity. To explore the ability of new drug/inhibitor molecules, which can show better/similar binding and dynamic stability as compared to known inhibitors, virtual screening against SMO is performed followed by the comparative docking and molecular dynamic studies. ‘ZINC12368305’ is found to be the best molecule among the entire data-set, as it shows the highest binding affinity and stable conformations. Here, an integrative approach using Dynamic Graph Theory is introduced to gain the molecular insights of the structural integrity of these protein complexes at the residue level by analyzing the corresponding Protein Contact Networks along the Molecular Dynamics trajectories. The study further focuses to understand the detailed binding mechanisms of available inhibitor/drug molecules along with the newly predicted molecule. It is observed that a unique big cluster of low fluctuating residues at the vicinity of the drug binding pocket of the SMO in ZINC12368305-bound complex is present and driving it toward a more stable region. A close inspection on this site reveals the presence of a stable Pi–Pi interaction between the pyrazole group-associated phenanthrene ring of ZINC12368305 and aromatic ring of Phe484 of SMO, which could be the potential factor of ZINC12368305 to create a more stable complex with SMO as compared to the other inhibitors. 相似文献
898.
Rune Nygaard Monrad Jens Eklöf Kristian B. R. M. Krogh 《Critical reviews in biotechnology》2018,38(7):1121-1136
Glucuronoyl esterases (GEs) belonging to the carbohydrate esterase family 15 (CE15) are involved in microbial degradation of lignocellulosic plant materials. GEs are capable of degrading complex polymers of lignin and hemicellulose cleaving ester bonds between glucuronic acid residues in xylan and lignin alcohols. GEs promote separation of lignin, hemicellulose and cellulose which is crucial for efficient utilization of biomass as an energy source and feedstock for further processing into products or chemicals. Genes encoding GEs are found in both fungi and bacteria, but, so far, bacterial GEs are essentially unexplored, and despite being discovered >10?years ago, only a limited number of GEs have been characterized. The first laboratory scale example of improved xylose and glucuronic acid release by the synergistic action of GE with cellulolytic enzymes was only reported recently (improved C5 sugar and glucuronic acid yields) and, until now, not much is known about their biotechnology potential. In this review, we discuss the diversity, structure and properties of microbial GEs and consider the status of their action on natural substrates and in biological systems in relation to their future industrial use. 相似文献
899.
Martina Devi 《Journal of biomolecular structure & dynamics》2018,36(4):1029-1049
Alanine is encoded by the four codons of the GC box (GCA, GCG, GCU, and GCC). Known alanine anticodons include the UGC, IGC, and VGC triplets (I = inosine; V = uridine-5-oxyacetic acid). The energy-minimized structures of all possible codon–anticodon combinations involving all the alanine codons GCA, GCG, GCU, and GCC with the alanine anticodons UGC, IGC, and VGC are studied using the AMBER software. Fifteen H-bonded duplex structures arising out of these combinations are studied here, all having Watson–Crick-type base pairs at the first and second codon positions, and a variety of base pairing possibilities at the third (or wobble) position. Structural and stability considerations suggest that some codon–anticodon duplexes would be more favored than others for accommodation during the translation process. The UGC anticodon is predicted to favor the GCA codon for reading, while the GCC codon is least favored. The IGC anticodon would prefer to read the GCC codon, the GCG codon being least favored, while a syn conformer for A in the GCA codon could allow for it to be read. For the VGC anticodon, the GCA codon is predicted to be read most favorably, and the GCC codon least favorably, while a syn conformer for V in the anticodon would allow for the codon GCU to be read through a wobble pair which involves the exocyclic 5-oxyacetate group of V in H-bonding. 相似文献
900.
蜘蛛抱蛋亚族的花粉形态 总被引:6,自引:0,他引:6
本文研究并报道了百合科蜘蛛抱蛋亚族的花粉形态,主要结论如下:1.开口箭属含两种花粉类型即:(1)单槽、椭圆形;(2)无萌发孔、球形。具单槽、椭圆形花粉的种类含单型性核型,花形较小,柱头小而花柱短,雄蕊高于柱头;无萌发孔、球形花粉的种类则为单型性核型,花形较大,柱头常高度膨大,雄蕊常着生在花被筒基部。2.万年青属花粉为椭圆形,具单槽;蜘蛛抱蛋属花粉则为球形,无萌发孔;开口箭属花粉一部分与万年青属相似,另一部分则与蜘蛛抱蛋属雷同。3.蜘蛛抱蛋亚族中最原始的花粉类型为单槽椭圆形,具孔状或网状外壁纹饰。球形,无萌发孔,外壁具皱波状、瘤状或芽孢状纹饰的花粉为派生类型。4.蜘蛛抱蛋亚族种下花粉形状、萌发孔类型和外壁纹饰基本稳定,可作为分种特征。 相似文献