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1.
Braz. j. biol ; 83: e247237, 2023. tab, graf
Article in English | MEDLINE, LILACS, VETINDEX | ID: biblio-1339386

ABSTRACT

Abstract Novel coronavirus (nCoV) namely "SARS-CoV-2" is being found responsible for current PANDEMIC commenced from Wuhan (China) since December 2019 and has been described with epidemiological linkage to China in about 221 countries and territories until now. In this study we have characterized the genetic lineage of SARS-CoV-2 and report the recombination within the genus and subgenus of coronaviruses. Phylogenetic relationship of thirty nine coronaviruses belonging to its four genera and five subgenera was analyzed by using the Neighbor-joining method using MEGA 6.0. Phylogenetic trees of full length genome, various proteins (spike, envelope, membrane and nucleocapsid) nucleotide sequences were constructed separately. Putative recombination was probed via RDP4. Our analysis describes that the "SARS-CoV-2" although shows great similarity to Bat-SARS-CoVs sequences through whole genome (giving sequence similarity 89%), exhibits conflicting grouping with the Bat-SARS-like coronavirus sequences (MG772933 and MG772934). Furthermore, seven recombination events were observed in SARS-CoV-2 (NC_045512) by RDP4. But not a single recombination event fulfills the high level of certainty. Recombination mostly housed in spike protein genes than rest of the genome indicating breakpoint cluster arises beyond the 95% and 99% breakpoint density intervals. Genetic similarity levels observed among "SARS-CoV-2" and Bat-SARS-CoVs advocated that the latter did not exhibit the specific variant that cause outbreak in humans, proposing a suggestion that "SARS-CoV-2" has originated possibly from bats. These genomic features and their probable association with virus characteristics along with virulence in humans require further consideration.


Resumo O novo coronavírus (nCoV), nomeadamente "SARS-CoV-2", foi considerado responsável pela pandemia atual iniciada em Wuhan (China) desde dezembro de 2019 e foi descrito com ligação epidemiológica à China em cerca de 221 países e territórios até agora. Neste estudo, caracterizamos a linhagem genética do SARS-CoV-2 e relatamos a recombinação dentro do gênero e subgênero dos coronavírus. A relação filogenética de 39 coronavírus pertencentes a seus quatro gêneros e cinco subgêneros foi analisada usando o método de Neighbour-joining usando MEGA 6.0. Árvores filogenéticas do genoma de comprimento total, várias proteínas (espícula, envelope, membrana e nucleocapsídeo), sequências de nucleotídeos foram construídas separadamente. A recombinação putativa foi testada via RDP4. Nossa análise descreve que o "SARS-CoV-2", embora mostre grande semelhança com as sequências de Bat-SARS-CoVs em todo o genoma (dando semelhança de sequência de 89%), exibe agrupamento conflitante com as sequências de coronavírus do tipo Bat-SARS (MG772933 e MG772934) Além disso, sete eventos de recombinação foram observados em SARS-CoV-2 (NC045512) por RDP4. Mas nem um único evento de recombinação preenche o alto nível de certeza. A recombinação está alojada mais em genes de proteína de pico, principalmente, do que no resto do genoma, indicando que o cluster de ponto de interrupção surge além dos intervalos de densidade de ponto de interrupção de 95% e 99%. Os níveis de similaridade genética observados entre "SARS-CoV-2" e Bat-SARS-CoVs defendem que o último não exibe a variante específica que causa surto em humanos, sugerindo que "SARS-CoV-2" tenha se originado possivelmente de morcegos. Essas características genômicas e sua provável associação com as características do vírus, juntamente com a virulência em humanos, requerem uma consideração mais aprofundada.


Subject(s)
Humans , Animals , Chiroptera , COVID-19 , Phylogeny , Computer Simulation , Genome, Viral/genetics , SARS-CoV-2
2.
Braz. j. biol ; 83: e244127, 2023. tab, graf
Article in English | MEDLINE, LILACS, VETINDEX | ID: biblio-1278526

ABSTRACT

Abstract Tiliroside is a glycosidic flavonoid present in many plants species including Helicteres velutina K. Schum (Malvaceae sensu lato), commonly known in Brazil as "pitó". This molecule has been shown to have many biological activities, however no study has been carried out to investigate the toxicity of this substance. The present work aimed to evaluate the possible cellular toxicity in silico, in vitro and ex-vivo of the kaempferol-3-O-β-D-(6"-E-p-coumaroyl) glucopyranoside (tiliroside), through chemical structure analysis, toxicity assessment and predictive bioactive properties, using human samples for in vitro and ex-vivo tests. The in silico analysis suggests that tiliroside exhibited great absorption index when penetrating biological membranes. In addition, it also displayed considerable potential for cellular protection against free radicals, and anticarcinogenic, antioxidant, antineoplastic, anti-inflammatory, anti-hemorrhagic and antithrombotic activities. The assessment of the hemolytic and genotoxic effects of tiliroside showed low hemolysis rates in red blood cells and absence of cellular toxicity in the oral mucosa cells. The data obtained indicate that this molecule could be a promising therapeutic approach as a possible new drug with biotechnological potential.


Resumo O tilirosídeo é um flavonóide glicosídico presente em muitas espécies de plantas, incluindo Helicteres velutina K. Schum (Malvaceae sensu lato), conhecida no Brasil como "pitó". Esta molécula mostrou ter muitas atividades biológicas, porém nenhum estudo foi realizado para investigar a toxicidade dessa substância. O presente trabalho teve como objetivo avaliar a possível toxicidade celular in silico, in vitro e ex-vivo do kaempferol-3-O-β-D- (6 "-Ep-coumaroil) glucopiranosídeo (tilirosídeo), por meio de análises de estrutura química, toxicidade avaliação e propriedades bioativas preditivas, utilizando amostras humanas para testes in vitro e ex-vivo. A análise in silico sugere que o tilirosídeo exibe bom índice de absorção para penetrar nas membranas biológicas. Além disso, apresentou considerável potencial de proteção celular contra os radicais livres e com atividades anticarcinogênica, antioxidante, antineoplásica, antiinflamatória, anti-hemorrágica e antitrombótica. A avaliação dos efeitos hemolíticos e genotóxicos do tilirosídeo mostrou baixas taxas de hemólise nas hemácias e ausência de toxicidade em células da mucosa oral. Os dados obtidos indicam que esta molécula pode possuir uma abordagem terapêutica promissora como uma possível nova droga com potencial biotecnológico.


Subject(s)
Humans , Plant Extracts , Kaempferols/toxicity , Flavonoids , Computer Simulation , Brazil
3.
Rev. Ciênc. Méd. Biol. (Impr.) ; 20(3): 375-386, dez 20, 2021. tab, fig
Article in Portuguese | LILACS | ID: biblio-1354189

ABSTRACT

Introdução: o sistema RANKL (receptor-ativador do fator nuclear-ligante κB)/RANK (receptor ativador do NF-kB)/OPG (osteoprotegrina) Introdução: o sistema OPG (osteoprotegrina)/RANK (receptor ativador do NF-kB)/RANKL (receptor-ativador do fator nuclear-ligante κB) regula os processos fisiológicos e patológicos da remodelação óssea. Polimorfismos genéticos nos genes OPG, RANK e RANKL têm sido associados a doenças, em diferentes populações. Objetivo: Descrever a frequência e o potencial regulatório dos polimorfismos do sistema OPG, RANK e RANKL em uma população brasileira; avaliar o seu potencial como marcadores genéticos informativos de ancestralidade; comparar com patologias associadas em outras populações. Metodologia: neste estudo, 506 indivíduos adultos, participantes de uma coorte acometidos de asma e periodontite, tiveram o DNA genômico extraído e genotipado, utilizando-se a plataforma Illumina. As plataformas NCBI, RegulomeDB, Haploview 4.2 e rSNPBase foram consultadas e utilizadas para análises. Resultados e Discussão: os polimorfismos mais frequentes na população estudada foram o rs3102724 no gene OPG, com frequência de menor alelo (MAF) de 46%; o rs4941129 em RANK, MAF 50%; e o rs9525641 em RANKL, MAF 46%. Os rs3134063 (1f) em OPG, rs17069898 (1f) em RANK e rs2200287 (1d) em RANKL apresentaram maior impacto funcional. Em OPG e RANK, nove polimorfismos se caracterizaram como marcadores genéticos informativos de ancestralidade, com predomínio nas populações YRI (africanos) e CEU (europeus). Os nove polimorfismos, com função intrônica, apresentaram MAF entre 2 a 46% na população-alvo e foram associados a patologias do metabolismo ósseo em outras populações. Conclusão: polimorfismos dos genes estudados se mostraram frequentes na população estudada e tiveram seus alelos mais frequentes associados a doenças em populações ancestrais. Sugere-se que sejam realizados mais estudos.


Introduction: The OPG (osteoprotegerin)/ RANK (NF-kB activating receptor)/ RANKL (nuclear-binding factor κB receptor-activating system regulates the physiological and pathological processes of bone remodeling. Genetic polymorphisms (SNPs) in OPG, RANK and RANKL genes have been associated with diseases in different populations. Objective: Describe the regulatory frequency and potential of SNPs in OPG, RANK and RANKL in a Brazilian population; assess their potential as informative genetic markers of ancestry; compare with pathologies associated with these polymorphisms in other populations. Methods: in this study, 506 adult individuals, participating in a cohort involving asthma and periodontitis, had genomic DNA extracted and genotyped using the Illumina platform. The NCBI, RegulomeDB, Haploview 4.2 and rSNPBase platforms were consulted and used for analysis. Results and discussion: the most frequent polymorphisms in the studied population were the rs3102724 in the OPG gene, with the lowest allele frequency (MAF) of 46%; rs4941129 in RANK, MAF 50% and rs9525641 in RANKL, MAF 46%. The rs3134063 (1f) in OPG, rs17069898 (1f) in RANK and rs2200287 (1d) in RANKL, had greater functional impact. In OPG and RANK, 9 SNPs were characterized as informative genetic markers of ancestry, predominantly in YRI (African) and CEU (European) populations. These 9 SNPs, with intronic function, presented MAF between 2 and 46% in our population, and were associated with pathologies in bone metabolism in other populations. Conclusion: SNPs of the studied genes were found to be frequent in the studied population and had their most frequent alleles associated with diseases in ancestral populations. It is suggested that further studies be carried out


Subject(s)
Humans , Male , Female , Adult , Polymorphism, Genetic , RANK Ligand , Genes , Periodontitis , Asthma , Computer Simulation
4.
Rev. bras. ginecol. obstet ; 43(6): 457-466, June 2021. tab, graf
Article in English | LILACS | ID: biblio-1341145

ABSTRACT

Abstract Objective Abnormalities in the eutopic endometrium of women with endometriosis may be related to disease-associated infertility. Although previous RNA-sequencing analysis did not show differential expression in endometrial transcripts of endometriosis patients, other molecular alterations could impact protein synthesis and endometrial receptivity. Our aim was to screen for functional mutations in the transcripts of eutopic endometria of infertile women with endometriosis and controls during the implantation window. Methods Data from RNA-Sequencing of endometrial biopsies collected during the implantation window from 17 patients (6 infertile women with endometriosis, 6 infertile controls, 5 fertile controls) were analyzed for variant discovery and identification of functional mutations. A targeted study of the alterations found was performed to understand the data into disease's context. Results None of the variants identified was common to other samples within the same group, and no mutation was repeated among patients with endometriosis, infertile and fertile controls. In the endometriosis group, nine predicted deleterious mutations were identified, but only one was previously associated to a clinical condition with no endometrial impact. When crossing the mutated genes with the descriptors endometriosis and/or endometrium, the gene CMKLR1 was associated either with inflammatory response in endometriosis or with endometrial processes for pregnancy establishment. Conclusion Despite no pattern of mutation having been found, we ponder the small sample size and the analysis on RNA-sequencing data. Considering the purpose of the study of screening and the importance of the CMKLR1 gene on endometrial


Resumo Objetivo Anormalidades no endométrio eutópico de mulheres com endometriose podem estar relacionadas à infertilidade associada à doença. Embora a análise prévia de sequenciamento de RNA não tenha evidenciado expressão diferencial em transcritos endometriais de pacientes com endometriose, outras alterações moleculares poderiam afetar a síntese de proteínas e a receptividade endometrial. Nosso objetivo foi rastrear mutações funcionais em transcritos de endométrios eutópicos de mulheres inférteis com endometriose e de controles durante a janela de implantação. Métodos Os dados do sequenciamento de RNA de biópsias endometriais coletados durante a janela de implantação de 17 pacientes (6 mulheres inférteis com endometriose, 6 controles inférteis, 5 controles férteis) foram analisados para a descoberta de variantes e a identificação de mutações funcionais. Um estudo direcionado das alterações encontradas foi realizado para compreender os dados no contexto da doença. Resultados Nenhuma das variantes identificadas foi comuma outras amostras dentro do mesmo grupo, assim como nenhuma mutação se repetiu entre pacientes com endometriose, controles inférteis e férteis. No grupo de endometriose, foram identificadas nove mutações deletérias preditas, mas apenas uma foi previamente associada a uma condição clínica sem impacto endometrial. Ao cruzar os genes mutados com os descritores endometriose e/ou endométrio, o gene CMKLR1 foi associado a resposta inflamatória na endometriose e a processos endometriais para estabelecimento da gravidez. Conclusão Apesar de nenhum padrão de mutação ter sido encontrado, ponderamos o pequeno tamanho da amostra e a análise dos dados de sequenciamento de RNA. Considerando o objetivo do estudo de triagem e a importância do gene CMKLR1 na modulação endometrial, este poderia ser um gene candidato para estudos adicionais que avaliem mutações no endométrio eutópico de pacientes com endometriose.


Subject(s)
Humans , Female , Pregnancy , Embryo Implantation , Sequence Analysis, RNA , Endometriosis/complications , Endometriosis/genetics , Endometrium/metabolism , Infertility, Female/etiology , Mutation , Computer Simulation , Case-Control Studies , Prospective Studies , Receptors, Chemokine/genetics , Infertility, Female/metabolism
5.
Article in Chinese | WPRIM | ID: wpr-880458

ABSTRACT

Accurate CT simulation is the key link of precision radiotherapy, and the performance of the localization couch of CT simulator directly affects the accuracy of radiotherapy. With the rapid development of precision radiotherapy, conventional large aperture radiotherapy special CT simulator is difficult to meet the needs of precision radiotherapy localization, so most radiotherapy centers choose high-end diagnostic CT machines equipped with a flat tabletop for radiotherapy localization. In clinical work, the performance testing of the CT simulator localization couch is easy to be ignored. In addition, there are some problems such as insufficient precision in transforming the cradle-shaped couch top of diagnostic CT into a special flat couch top for radiotherapy. This paper provided an in-depth description of the improved design and performance test of the localization couch of the first special GE Revolution CT simulator for radiotherapy introduced by West China Hospital of Sichuan University. After the improvement, all the acceptance tests of the localization couch are in line with the standard, and the performance meets the high-precision radiotherapy localization needs of patients with different body weight in the center.


Subject(s)
China , Computer Simulation , Humans , Phantoms, Imaging , Radiotherapy Planning, Computer-Assisted , Tomography, X-Ray Computed
6.
Article in Chinese | WPRIM | ID: wpr-880417

ABSTRACT

In order to obtain the three-dimensional pulse information and blood pressure waveform needed in the study, a radial artery simulation platform with programmable controlled injection pump as the core was constructed by using the circulation theory of human cardiovascular system and pulse wave formation mechanism. Gaussian function model was selected to synthesize multi-type pulse wave to program and drive the platform. The three-dimensional pulse information and blood pressure waveform of the simulated radial artery were collected by binocular visual pulse detection system and pressure transmitter respectively, and the platform stability and repeatability were tested by Pearson correlation. The experimental results show that the radial artery simulation platform is stable, reliable and repeatable, and can generate multiple types of three-dimensional pulse information and blood pressure waveform at the simulated radial artery. The platform is simple in structure, low in cost, and produces many types of pulsating flow. It provides an experimental research platform for revealing the relationship between the three-dimensional pulse information of radial artery and the change of pressure inside the vessel, as well as the prediction of blood pressure waveform from the three-dimensional pulse information.


Subject(s)
Blood Pressure , Computer Simulation , Heart Rate , Humans , Radial Artery , Vital Signs
7.
Article in Chinese | WPRIM | ID: wpr-880412

ABSTRACT

The ECG signal is susceptible to interference from the external environment during the acquisition process, affecting the analysis and processing of the ECG signal. After the traditional soft-hard threshold function is processed, there is a defect that the signal quality is not high and the continuity at the threshold is poor. An improved threshold function wavelet denoising is proposed, which has better regulation and continuity, and effectively solves the shortcomings of traditional soft and hard threshold functions. The Matlab simulation is carried out through a large amount of data, and various processing methods are compared. The results show that the improved threshold function can improve the denoising effect and is superior to the traditional soft and hard threshold denoising.


Subject(s)
Algorithms , Computer Simulation , Electrocardiography , Signal Processing, Computer-Assisted , Wavelet Analysis
8.
Article in Chinese | WPRIM | ID: wpr-888203

ABSTRACT

The brain-computer interface (BCI) systems used in practical applications require as few electroencephalogram (EEG) acquisition channels as possible. However, when it is reduced to one channel, it is difficult to remove the electrooculogram (EOG) artifacts. Therefore, this paper proposed an EOG artifact removal algorithm based on wavelet transform and ensemble empirical mode decomposition. Firstly, the single channel EEG signal is subjected to wavelet transform, and the wavelet components which involve EOG artifact are decomposed by ensemble empirical mode decomposition. Then the predefined autocorrelation coefficient threshold is used to automatically select and remove the intrinsic modal functions which mainly composed of EOG components. And finally the 'clean' EEG signal is reconstructed. The comparative experiments on the simulation data and the real data show that the algorithm proposed in this paper solves the problem of automatic removal of EOG artifacts in single-channel EEG signals. It can effectively remove the EOG artifacts when causes less EEG distortion and has less algorithm complexity at the same time. It helps to promote the BCI technology out of the laboratory and toward commercial application.


Subject(s)
Algorithms , Artifacts , Computer Simulation , Electroencephalography , Signal Processing, Computer-Assisted , Wavelet Analysis
9.
J. venom. anim. toxins incl. trop. dis ; 27: e20200073, 2021. tab, graf, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1154769

ABSTRACT

he resistance against antimalarial drugs represents a global challenge in the fight and control of malaria. The Brazilian biodiversity can be an important tool for research and development of new medicinal products. In this context, toxinology is a multidisciplinary approach on the development of new drugs, including the isolation, purification, and evaluation of the pharmacological activities of natural toxins. The present study aimed to evaluate the cytotoxicity, as well as the antimalarial activity in silico and in vitro of four compounds isolated from Rhinella marina venom as potential oral drug prototypes. Methods: Four compounds were challenged against 35 target proteins from P. falciparum and screened to evaluate their physicochemical properties using docking assay in Brazilian Malaria Molecular Targets (BraMMT) software and in silico assay in OCTOPUS® software. The in vitro antimalarial activity of the compounds against the 3D7 Plasmodium falciparum clones were assessed using the SYBR Green I based assay (IC50). For the cytotoxic tests, the LD50 was determined in human pulmonary fibroblast cell line using the [3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay. Results: All compounds presented a ligand-receptor interaction with ten Plasmodium falciparum-related protein targets, as well as antimalarial activity against chloroquine resistant strain (IC50 = 3.44 µM to 19.11 µM). Three of them (dehydrobufotenine, marinobufagin, and bufalin) showed adequate conditions for oral drug prototypes, with satisfactory prediction of absorption, permeability, and absence of toxicity. In the cell viability assay, only dehydrobufotenin was selective for the parasite. Conclusions: Dehydrobufotenin revealed to be a potential oral drug prototype presenting adequate antimalarial activity and absence of cytotoxicity, therefore should be subjected to further studies.(AU)


Subject(s)
Bufanolides/administration & dosage , Bufonidae , Biodiversity , Malaria/immunology , Antimalarials , In Vitro Techniques , Computer Simulation
10.
Braz. J. Vet. Res. Anim. Sci. (Online) ; 58(n.esp): e174951, 2021. tab, ilus, graf
Article in English | LILACS, VETINDEX | ID: biblio-1348268

ABSTRACT

Vehicle-animal collisions represent a serious problem in roadway infrastructure. To avoid these roadway collisions, different mitigation systems have been applied in various regions of the world. In this article, a system for detecting animals on highways is presented using computer vision and machine learning algorithms. The models were trained to classify two groups of animals: capybaras and donkeys. Two variants of the convolutional neural network called Yolo (You only look once) were used, Yolov4 and Yolov4-tiny (a lighter version of the network). The training was carried out using pre-trained models. Detection tests were performed on 147 images. The accuracy results obtained were 84.87% and 79.87% for Yolov4 and Yolov4-tiny, respectively. The proposed system has the potential to improve road safety by reducing or preventing accidents with animals.(AU)


As colisões entre veículos e animais representam um sério problema na infraestrutura rodoviária. Para evitar tais acidentes, medidas mitigatórias têm sido aplicadas em diferentes regiões do mundo. Neste projeto é apresentado um sistema de detecção de animais em rodovias utilizando visão computacional e algoritmo de aprendizado de máquina. Os modelos foram treinados para classificar dois grupos de animais: capivaras e equídeos. Foram utilizadas duas variantes da rede neural convolucional chamada Yolo (você só vê uma vez) ­ Yolov4 e Yolov4-tiny (versão mais leve da rede) ­ e o treinamento foi realizado a partir de modelos pré-treinados. Testes de detecção foram realizados em 147 imagens e os resultados de precisão obtidos foram de 84,87% e 79,87% para Yolov4 e Yolov4-tiny, respectivamente. O sistema proposto tem o potencial de melhorar a segurança rodoviária reduzindo ou prevenindo acidentes com animais.(AU)


Subject(s)
Animals , Computer Simulation , Accidents, Traffic , Animals
11.
Chinese Journal of Biotechnology ; (12): 2836-2844, 2021.
Article in Chinese | WPRIM | ID: wpr-887846

ABSTRACT

It has been reported that ODB genes play an important role in homologous recombination-directed DNA repair, suggesting their potential applications in plant breeding. To analyze the expression characteristics of tobacco NtODB gene, the cDNA sequence of NtODB was obtained using in silico cloning technique. The physicochemical properties, signal peptide, and advanced structures of the predicted protein were analyzed using bioinformatics tools. The results showed that the NtODB gene has a 579-bp open reading frame which encodes a protein with 192 amino acid residues. The protein NtODB is predicted to be alkaline and hydrophilic. Real-time quantitative PCR showed that NtODB was constitutively expressed in different tissues. Subcellular localization showed that NtODB was mainly expressed in cell membrane and chloroplast. These results may help us to better understand and elucidate the roles of ODB genes in the homologous recombination-directed DNA repair.


Subject(s)
Amino Acid Sequence , Base Sequence , Cloning, Molecular , Computational Biology , Computer Simulation , DNA, Complementary , Phylogeny , Plant Breeding , Tobacco/genetics
12.
Article in Chinese | WPRIM | ID: wpr-922063

ABSTRACT

The panoramic perception of medical equipment operation and maintenance status is the basic guarantee for the implementation of smart medical care, the machine learning algorithm-based autonomous perception and active early warning model of medical equipment operation and maintenance status is proposed. Introduce deep learning multi-dimensional perception of medical equipment multi-source heterogeneous fault data training sample characteristics to realize autonomous perception of medical equipment operation and maintenance status, introduce reinforcement learning to realize autonomous decision-making of test sample fault characteristics, and build the active early warning mechanism for medical equipment faults. Taking the equipment department of hospital as the carrier of model effectiveness verification, the effectiveness simulation of the model was carried out, the results show that the model has the advantages of comprehensive fault information perception, strong compatibility of medical equipment, high efficiency of active early warning.


Subject(s)
Algorithms , Computer Simulation , Machine Learning , Self Concept , Surgical Equipment
13.
Article in Chinese | WPRIM | ID: wpr-921901

ABSTRACT

OBJECTIVE@#To explore safety and accuracy of novel C@*METHODS@#From January 2018 to June 2018, 40 patients who underwent three-dimensional CT of cervical spine were selected, including 21 males and 19 females, heighted from 165 to 180 cm with an average of (172.9±9.5) cm, aged from 38 to 55 years old (51.1±12.8) years old, excluding patients with axis lamina defect and hypoplasia. Two sets of 3D printed specimens were made from the three-dimensional CT data of cervical spine of each patient, and both of than were used for the in vitro nailing experiment. According to different nail placement methods, in vitro experimental part of this experiment was divided into guide nail placement group and hand nail placement group, 40 pieces in each group. At the same time, the three-dimensionalmodel of cervical spine of 40 patients was reconstructed on computer, and the ideal needle point data and inclination angle were obtained by computer simulation of the nail placement. This is 3D simulation nail placement group, 40 pieces. With vitro experiment, the risk level of screw placement, the position of needle exit point and inclination angle were measured in guide nail group and hand nail group. Based on the accuracy of needle point and inclination angle of nail path, the data of guide nail group, the hand nail group and 3D simulation nail group were compared, and the data of each group were statistically analyzed to determine the accuracy.@*RESULTS@#In guide nail group, 75 screws were acceptable and 5 were dangerous. The acceptable rate was 94%, and the double cortical rate was 93%. There were 62 position-acceptable screws in hand nail group, and 18 positions were dangerous, with an acceptable rate of 78% and a double cortical rate of 33%. The difference between two groups was statistically significant (@*CONCLUSION@#The guide is universal, with stable structure, accurate guidance, and easy operation. It could be placed with bilateral lamina screws at the same time, shortening the time of nail placement, avoiding collision of two way cross screws, increase the rate of double cortex. Ultimately, efficiency and security can be improved.


Subject(s)
Adult , Bone Plates , Cervical Vertebrae , Computer Simulation , Female , Humans , Male , Middle Aged , Spinal Fusion , Tomography, X-Ray Computed
14.
Article in English | WPRIM | ID: wpr-921882

ABSTRACT

To get an optimal product of orthopaedic implant or regenerative medicine needs to follow trial-and-error analyses to investigate suitable product's material, structure, mechanical properites etc. The whole process from


Subject(s)
Cell Differentiation , Cell Movement , Cell Proliferation , Computer Simulation , Tissue Engineering
15.
Article in English | WPRIM | ID: wpr-921871

ABSTRACT

Objective We developed a universal lesion detector (ULDor) which showed good performance in in-lab experiments. The study aims to evaluate the performance and its ability to generalize in clinical setting via both external and internal validation. Methods The ULDor system consists of a convolutional neural network (CNN) trained on around 80K lesion annotations from about 12K CT studies in the DeepLesion dataset and 5 other public organ-specific datasets. During the validation process, the test sets include two parts: the external validation dataset which was comprised of 164 sets of non-contrasted chest and upper abdomen CT scans from a comprehensive hospital, and the internal validation dataset which was comprised of 187 sets of low-dose helical CT scans from the National Lung Screening Trial (NLST). We ran the model on the two test sets to output lesion detection. Three board-certified radiologists read the CT scans and verified the detection results of ULDor. We used positive predictive value (PPV) and sensitivity to evaluate the performance of the model in detecting space-occupying lesions at all extra-pulmonary organs visualized on CT images, including liver, kidney, pancreas, adrenal, spleen, esophagus, thyroid, lymph nodes, body wall, thoracic spine,


Subject(s)
Computer Simulation , Computers , Neural Networks, Computer , Tomography, X-Ray Computed
16.
Journal of Biomedical Engineering ; (6): 1097-1102, 2021.
Article in Chinese | WPRIM | ID: wpr-921850

ABSTRACT

Atherosclerotic plaque rupture is the main cause of many cardiovascular diseases, and biomechanical factors play an important role in the process of plaque rupture. In the study of plaque biomechanics, there are relatively few studies based on fatigue fracture failure theory, and most of them mainly focus on the whole fatigue propagation process from crack initiation to plaque rupture, while there are few studies on the influence of crack on plaque rupture at a certain time in the process of fatigue propagation. In this paper, a two-dimensional plaque model with crack was established. Based on the theory of fracture mechanics and combined with the finite element numerical simulation method, the stress intensity factor (SIF) and related influencing factors at the crack tip in the plaque were studied. The SIF was used to measure the influence of crack on plaque rupture. The results show that the existence of crack can lead to local stress concentration, which increases the risk of plaque rupture. The SIF at the crack tip in the plaque was positively correlated with blood pressure, but negatively correlated with fibrous cap thickness and lipid pool stiffness. The effect of the thickness and angle of lipid pool on the SIF at the crack tip in the plaque was less than 4%, which could be ignored. This study provides a theoretical basis for the risk assessment of plaque rupture with cracks.


Subject(s)
Biomechanical Phenomena , Computer Simulation , Humans , Plaque, Atherosclerotic , Stress, Mechanical
17.
Journal of Biomedical Engineering ; (6): 1081-1086, 2021.
Article in Chinese | WPRIM | ID: wpr-921848

ABSTRACT

In this paper, a new surface electromyography (sEMG) signal decomposition method based on spatial location is proposed for the high-density sEMG signals in dynamic muscle contraction. Firstly, according to the waveform correlation of each muscle motor units (MU) in each channel, the firing times are extracted, and then the firing times are classified by the spatial location of MU. The MU firing trains are finally obtained. The simulation results show that the accuracy rate of a single MU firing train after classification is more than 91.67%. For real sEMG signals, the accuracy rate to find a same MU by the "two source" method is over (88.3 ± 2.1)%. This paper provides a new idea for dynamic sEMG signal decomposition.


Subject(s)
Action Potentials , Computer Simulation , Electromyography , Muscle Contraction , Muscle, Skeletal
18.
Article in Chinese | WPRIM | ID: wpr-921831

ABSTRACT

Craniofacial malformation caused by premature fusion of cranial suture of infants has a serious impact on their growth. The purpose of skull remodeling surgery for infants with craniosynostosis is to expand the skull and allow the brain to grow properly. There are no standardized treatments for skull remodeling surgery at the present, and the postoperative effect can be hardly assessed reasonably. Children with sagittal craniosynostosis were selected as the research objects. By analyzing the morphological characteristics of the patients, the point cloud registration of the skull distortion region with the ideal skull model was performed, and a plan of skull cutting and remodeling surgery was generated. A finite element model of the infant skull was used to predict the growth trend after remodeling surgery. Finally, an experimental study of surgery simulation was carried out with a child with a typical sagittal craniosynostosis. The evaluation results showed that the repositioning and stitching of bone plates effectively improved the morphology of the abnormal parts of the skull and had a normal growth trend. The child's preoperative cephalic index was 65.31%, and became 71.50% after 9 months' growth simulation. The simulation of the skull remodeling provides a reference for surgical plan design. The skull remodeling approach significantly improves postoperative effect, and it could be extended to the generation of cutting and remodeling plans and postoperative evaluations for treatment on other types of craniosynostosis.


Subject(s)
Child , Computer Simulation , Cranial Sutures/surgery , Craniosynostoses/surgery , Humans , Infant , Skull/surgery
19.
Chinese Journal of Biotechnology ; (12): 4439-4445, 2021.
Article in Chinese | WPRIM | ID: wpr-921519

ABSTRACT

Microbial Engineering is a practical and applied course, it is therefore an indispensable part of teaching to let the students practice in the production line of an enterprise. However, lack of internship resources has always been a bottleneck hampering the high-level internship training during teaching the Microbial Engineering course. A virtual production line developed based on information technology enables students to learn the theoretical knowledge of the complex production system. Moreover, it enables students to perform complex virtual operations, thereby improving students' practicing and innovation abilities. In order to let the virtual simulation experiments project play a great role in undergraduate teaching, this article summarizes the progress, characteristics, and value of the virtual simulation experiments for Microbial Engineering. In addition, the main challenges that limit its shared application are also discussed, with potential solutions prospected.


Subject(s)
Computer Simulation , Curriculum , Humans , Learning , Students
20.
Article in Chinese | WPRIM | ID: wpr-888636

ABSTRACT

Thermal ablation surgery can effectively eliminate bone tumors in the spine and meanwhile reduce damage to the human body. To realize the computer modeling and simulation of spine thermal ablation surgery, it is necessary to ensure the accuracy of both spine modeling and simulation temperature. This review summarizes the research progress of this field and analyzes the prospects from two aspects: computer modeling based on spine segmentation from medical images and simulation calculation of temperature field in ablation surgery. The research on spine segmentation has made great progress, but there are still some problems that prevent it from being applied in clinical simulation. Related research has been trying to solve the problems. For the ablation surgery of the spine, some researchers have tried ablation simulation and obtained simulation results that are relatively consistent with the actual temperature value.


Subject(s)
Catheter Ablation , Computer Simulation , Computers , Humans , Hyperthermia, Induced , Spine/surgery
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