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1.
Infect Immun ; 91(12): e0024523, 2023 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-37916806

RESUMEN

Virus-like particles (VLPs) are promising nanotools for the development of subunit vaccines due to high immunogenicity and safety. Herein, we explored the versatile and effective Tag/Catcher-AP205 capsid VLP (cVLP) vaccine platform to address the urgent need for the development of an effective and safe vaccine against gonorrhea. The benefits of this clinically validated cVLP platform include its ability to facilitate unidirectional, high-density display of complex/full-length antigens through an effective split-protein Tag/Catcher conjugation system. To assess this modular approach for making cVLP vaccines, we used a conserved surface lipoprotein, SliC, that contributes to the Neisseria gonorrhoeae defense against human lysozyme, as a model antigen. This protein was genetically fused at the N- or C-terminus to the small peptide Tag enabling their conjugation to AP205 cVLP, displaying the complementary Catcher. We determined that SliC with the N-terminal SpyTag, N-SliC, retained lysozyme-blocking activity and could be displayed at high density on cVLPs without causing aggregation. In mice, the N-SliC-VLP vaccines, adjuvanted with AddaVax or CpG, induced significantly higher antibody titers compared to controls. In contrast, similar vaccine formulations containing monomeric SliC were non-immunogenic. Accordingly, sera from N-SliC-VLP-immunized mice also had significantly higher human complement-dependent serum bactericidal activity. Furthermore, the N-SliC-VLP vaccines administered subcutaneously with an intranasal boost elicited systemic and vaginal IgG and IgA, whereas subcutaneous delivery alone failed to induce vaginal IgA. The N-SliC-VLP with CpG (10 µg/dose) induced the most significant increase in total serum IgG and IgG3 titers, vaginal IgG and IgA, and bactericidal antibodies.


Asunto(s)
Neisseria gonorrhoeae , Vacunas de Partículas Similares a Virus , Animales , Femenino , Humanos , Ratones , Antígenos Bacterianos/genética , Antígenos Bacterianos/inmunología , Cápside , Inmunoglobulina A , Inmunoglobulina G , Ratones Endogámicos BALB C , Muramidasa , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/inmunología , Vacunas de Partículas Similares a Virus/genética , Vacunas de Partículas Similares a Virus/inmunología
2.
Sensors (Basel) ; 19(3)2019 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-30682823

RESUMEN

Hyperspectral Images (HSIs) contain enriched information due to the presence of various bands, which have gained attention for the past few decades. However, explosive growth in HSIs' scale and dimensions causes "Curse of dimensionality" and "Hughes phenomenon". Dimensionality reduction has become an important means to overcome the "Curse of dimensionality". In hyperspectral images, labeled samples are more difficult to collect because they require many labor and material resources. Semi-supervised dimensionality reduction is very important in mining high-dimensional data due to the lack of costly-labeled samples. The promotion of the supervised dimensionality reduction method to the semi-supervised method is mostly done by graph, which is a powerful tool for characterizing data relationships and manifold exploration. To take advantage of the spatial information of data, we put forward a novel graph construction method for semi-supervised learning, called SLIC Superpixel-based l 2 , 1 -norm Robust Principal Component Analysis (SURPCA2,1), which integrates superpixel segmentation method Simple Linear Iterative Clustering (SLIC) into Low-rank Decomposition. First, the SLIC algorithm is adopted to obtain the spatial homogeneous regions of HSI. Then, the l 2 , 1 -norm RPCA is exploited in each superpixel area, which captures the global information of homogeneous regions and preserves spectral subspace segmentation of HSIs very well. Therefore, we have explored the spatial and spectral information of hyperspectral image simultaneously by combining superpixel segmentation with RPCA. Finally, a semi-supervised dimensionality reduction framework based on SURPCA2,1 graph is used for feature extraction task. Extensive experiments on multiple HSIs showed that the proposed spectral-spatial SURPCA2,1 is always comparable to other compared graphs with few labeled samples.

3.
Neurosurg Focus ; 43(5): E19, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29088951

RESUMEN

Traumatic spinal cord injury (SCI) often occurs in patients with concurrent traumatic injuries in other body systems. These patients with polytrauma pose unique challenges to clinicians. The current review evaluates existing guidelines and updates the evidence for prehospital transport, immobilization, initial resuscitation, critical care, hemodynamic stability, diagnostic imaging, surgical techniques, and timing appropriate for the patient with SCI who has multisystem trauma. Initial management should be systematic, with focus on spinal immobilization, timely transport, and optimizing perfusion to the spinal cord. There is general evidence for the maintenance of mean arterial pressure of > 85 mm Hg during immediate and acute care to optimize neurological outcome; however, the selection of vasopressor type and duration should be judicious, with considerations for level of injury and risks of increased cardiogenic complications in the elderly. Level II recommendations exist for early decompression, and additional time points of neurological assessment within the first 24 hours and during acute care are warranted to determine the temporality of benefits attributable to early surgery. Venous thromboembolism prophylaxis using low-molecular-weight heparin is recommended by current guidelines for SCI. For these patients, titration of tidal volumes is important to balance the association of earlier weaning off the ventilator, with its risk of atelectasis, against the risk for lung damage from mechanical overinflation that can occur with prolonged ventilation. Careful evaluation of infection risk is a priority following multisystem trauma for patients with relative immunosuppression or compromise. Although patients with polytrauma may experience longer rehabilitation courses, long-term neurological recovery is generally comparable to that in patients with isolated SCI after controlling for demographics. Bowel and bladder disorders are common following SCI, significantly reduce quality of life, and constitute a focus of targeted therapies. Emerging biomarkers including glial fibrillary acidic protein, S100ß, and microRNAs for traumatic SCIs are presented. Systematic management approaches to minimize sources of secondary injury are discussed, and areas requiring further research, implementation, and validation are identified.


Asunto(s)
Cuidados Críticos , Traumatismo Múltiple/cirugía , Traumatismos de la Médula Espinal/cirugía , Médula Espinal/cirugía , Descompresión Quirúrgica/métodos , Humanos , Calidad de Vida
4.
AJR Am J Roentgenol ; 206(6): 1292-7, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27043893

RESUMEN

OBJECTIVE: The aim of our blinded retrospective study was to evaluate the diagnostic performance of the Subaxial Cervical Spine Injury Classification (SLIC) System in predicting the need for surgical intervention after subaxial cervical spine injury; SLIC scores were determined using CT alone or both CT and MRI. MATERIALS AND METHODS: Patients were included if they had injuries that were subaxial (C3-C7), if they had undergone CT and MRI within 48 hours of admission, if they were either treated surgically or had sufficient clinical documentation describing nonsurgical management (halo device or hard collar), and if the SLIC neurologic score could be determined from a documented neurologic examination. Two hundred two consecutive patients (139 surgical patients and 63 nonsurgical control subjects) from January 2010 through December 2013 met all criteria and were included in the study. Additionally, 40 patients were randomly selected from this group for the purpose of determining interrater agreement. Initially, readers gave a SLIC score (< 4 for nonsurgical, 4 = indeterminate, > 4 for surgical) based on neurologic status and CT only. After waiting 4 weeks to minimize recall bias, the readers repeated scoring with the addition of MRI. Diagnostic performance values-that is, sensitivity, specificity, AUC under the ROC curve, and interrater agreement (Cohen kappa)-for both trials were determined. RESULTS: Using a SLIC score of 4 as the cutoff value for surgical intervention, we found that SLIC scoring based on CT and MRI had a sensitivity of 94.6%, specificity of 71.0%, and AUC of 0.87 with a kappa value of 0.28. SLIC scoring based on CT alone had a sensitivity of 86.2%, specificity of 77.3%, and AUC of 0.88 with a kappa value of 0.52. CONCLUSION: SLIC scoring based on CT alone performs similarly to SLIC scoring based on CT and MRI but with improved interobserver agreement. Although MRI is useful for surgical planning, these results indicate that MRI may have limited added value in the initial triage of patients with subaxial cervical spine injury for conservative versus surgical management.


Asunto(s)
Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/lesiones , Imagen por Resonancia Magnética , Traumatismos Vertebrales/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Puntaje de Gravedad del Traumatismo , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Selección de Paciente , Valor Predictivo de las Pruebas , Curva ROC , Estudios Retrospectivos , Traumatismos Vertebrales/cirugía , Adulto Joven
5.
Eur Spine J ; 25(1): 74-79, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26394857

RESUMEN

PURPOSE: To verify the clinical applicability of a modified classification system in distractive-extension cervical spine injury that reflects the degrees of soft tissue damage and spinal cord injury while complementing previous Allen classification and subaxial cervical spine injury classification (SLIC) system. METHODS: A total of 195 patients with cervical spine distraction-extension (DE) injury were retrospectively classified. We added stages IIIA (with concomitant spinal cord injury without bony abnormalities) and IIIB (with concomitant additional soft tissue swelling) to the existing stages I and II of the Allen classification. We also supplemented the SLIC system by refining and assigning scores to bony morphology and soft tissue damage. The previous and proposed classification systems were compared by analyzing their scoring performances in terms of clinical features and prognosis. RESULTS: The Allen classification yielded 153 and 42 patients with stage 1 and 42 stage 2 injuries, respectively. Patients classified according to the proposed system were stratified as follows: stage I, 58; stage II, 27; stage IIIA, 33; and stage IIIB, 77. Regarding neurological symptoms and prognosis, stages IIIA and IIIB were poorer than stage I but significantly better than stage II (P < 0.05). On the SLIC system, 146 patients scored ≥5; and 37 and 12 patients scored 4 and ≤3 points, respectively, whereas the numbers of patients who scored ≥5, 4, and ≤3 points on the modified SLIC system were 170, 21, and 4, respectively. CONCLUSIONS: The proposed classification and scoring system to complement the Allen classification and SLIC system with respect to the degrees of soft tissue damage and spinal cord injury is considered effective for diagnosing and determining therapeutic directions and prognosis in cases of cervical spine extension injury.


Asunto(s)
Vértebras Cervicales/lesiones , Traumatismos Vertebrales/clasificación , Adulto , Anciano , Edema/clasificación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Traumatismos de los Tejidos Blandos/clasificación , Adulto Joven
6.
J Spinal Cord Med ; 37(4): 420-4, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24090539

RESUMEN

OBJECTIVE: The Subaxial Injury Classification (SLIC) system has been developed to improve injury classification and guide surgical decision making yet clinical validation remains necessary. METHODS: We evaluated the validity and safety of the SLIC system prospectively in patients treated for subaxial cervical spine trauma (SCST) between 2009 and 2012. Patients with four or more points were surgically treated, whereas patients with less than 4 points were conservatively managed. OUTCOME MEASURES: Neurological status was assessed as the primary outcome of successful treatment. RESULTS: Non-surgical group - Twenty-three patients were treated non-surgically, 14 (61%) of them with some follow-up at our institution. Follow-up ranged from 3 to 5 months (mean of 4.42; median 4). The SLIC score ranged from 0 to 6 points (mean and median of 1). One patient with a SLIC of 6 points refused surgery. Surgical group: Twenty-five patients were operated, but follow-up after hospital discharge was obtained in 23 (92%) patients (range from 1 to 24 months, mean of 5.82 months). The SLIC score in this group ranged from 4 to 9 points (mean and median of 7). No patients had neurological worsening. Eight of 13 patients with incomplete deficits had some improvement in American Spinal Injury Association score. CONCLUSIONS: This is the first prospective application of the SLIC system. With regard to our primary outcome, neurological status, the SLIC system was found to be a safe and effective guide in the surgical treatment of SCST.


Asunto(s)
Vértebras Cervicales/lesiones , Vértebras Cervicales/patología , Puntaje de Gravedad del Traumatismo , Traumatismos Vertebrales/diagnóstico , Adulto , Anciano , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Traumatismos Vertebrales/patología , Tomografía Computarizada por Rayos X , Adulto Joven
7.
Med Biol Eng Comput ; 62(8): 2571-2583, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38649629

RESUMEN

Diabetic retinopathy disease contains lesions (e.g., exudates, hemorrhages, and microaneurysms) that are minute to the naked eye. Determining the lesions at pixel level poses a challenge as each pixel does not reflect any semantic entities. Furthermore, the computational cost of inspecting each pixel is expensive because the number of pixels is high even at low resolution. In this work, we propose a hybrid image processing method. Simple Linear Iterative Clustering with Gaussian Filter (SLIC-G) for the purpose of overcoming pixel constraints. The SLIC-G image processing method is divided into two stages: (1) simple linear iterative clustering superpixel segmentation and (2) Gaussian smoothing operation. In such a way, a large number of new transformed datasets are generated and then used for model training. Finally, two performance evaluation metrics that are suitable for imbalanced diabetic retinopathy datasets were used to validate the effectiveness of the proposed SLIC-G. The results indicate that, in comparison to prior published works' results, the proposed SLIC-G shows better performance on image classification of class imbalanced diabetic retinopathy datasets. This research reveals the importance of image processing and how it influences the performance of deep learning networks. The proposed SLIC-G enhances pre-trained network performance by eliminating the local redundancy of an image, which preserves local structures, but avoids over-segmented, noisy clips. It closes the research gap by introducing the use of superpixel segmentation and Gaussian smoothing operation as image processing methods in diabetic retinopathy-related tasks.


Asunto(s)
Aprendizaje Profundo , Retinopatía Diabética , Fondo de Ojo , Procesamiento de Imagen Asistido por Computador , Retinopatía Diabética/diagnóstico por imagen , Retinopatía Diabética/patología , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Algoritmos , Redes Neurales de la Computación , Fotograbar/métodos , Interpretación de Imagen Asistida por Computador/métodos , Distribución Normal
8.
J Neurosurg Pediatr ; : 1-8, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38968630

RESUMEN

OBJECTIVE: The Subaxial Cervical Spine Injury Classification (SLIC) score has not been previously validated for a pediatric population. The authors compared the SLIC treatment recommendations for pediatric subaxial cervical spine trauma with real-world pediatric spine surgery practice. METHODS: A retrospective cohort study at a pediatric level 1 trauma center was conducted in patients < 18 years of age evaluated for trauma from 2012 to 2021. An SLIC score was calculated for each patient, and the subsequent recommendations were compared with actual treatment delivered. Percentage misclassification, sensitivity, specificity, positive (PPV) and negative predictive value (NPV), and area under the receiver operating characteristic (ROC) curve (AUC) were calculated. RESULTS: Two hundred forty-three pediatric patients with trauma were included. Twenty-five patients (10.3%) underwent surgery and 218 were managed conservatively. The median SLIC score was 2 (interquartile range = 2). Sixteen patients (6.6%) had an SLIC score of 4, for which either conservative or surgical treatment is recommended; 27 children had an SLIC score ≥ 5, indicating a recommendation for surgical treatment; and 200 children had an SLIC score ≤ 3, indicating a recommendation for conservative treatment. Of the 243 patients, 227 received treatment consistent with SLIC score recommendations (p < 0.001). SLIC sensitivity in determining surgically treated patients was 79.2% and the specificity for accurately determining who underwent conservative treatment was 96.1%. The PPV was 70.3% and the NPV was 97.5%. There was a 5.7% misclassification rate (n = 13) using SLIC. Among patients for whom surgical treatment would be recommended by the SLIC, 29.6% (n = 8) did not undergo surgery; similarly, 2.5% (n = 5) of patients for whom conservative management would be recommended by the SLIC had surgery. The ROC curve for determining treatment received demonstrated excellent discriminative ability, with an AUC of 0.96 (OR 3.12, p < 0.001). Sensitivity decreased when the cohort was split by age (< 10 and ≥ 10 years old) to 0.5 and 0.82, respectively; specificity remained high at 0.98 and 0.94. CONCLUSIONS: The SLIC scoring system recommended similar treatment when compared with the actual treatment delivered for traumatic subaxial cervical spine injuries in children, with a low misclassification rate and a specificity of 96%. These findings demonstrate that the SLIC can be useful in guiding treatment for pediatric patients with subaxial cervical spine injuries. Further investigation into the score in young children (< 10 years) using a multicenter cohort is warranted.

9.
Heliyon ; 9(10): e20467, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37810825

RESUMEN

To effectively classify tree species within datasets characterized by limited samples, we introduced a novel approach named DenseNetBL, founded upon the fusion of the DenseNet architecture and a pivotal bottleneck layer. This bottleneck layer, encompassing a compact convolutional component, played a central role in our methodology. The evaluation of DenseNetBL was conducted under varying conditions, encompassing small-sample tree species data, extensive remote sensing datasets, and state-of-the-art classifiers. Furthermore, a quantitative assessment was executed to extract tree species areas. This was achieved by quantifying pixel areas within manually delineated tree species maps and classifier-generated counterparts. The findings of our study indicated that, in scenarios devoid of pre-trained weights, DenseNetBL consistently outperformed its DenseNet counterpart with equivalent layer numbers. In the realm of small-sample situations, both the Swin Transformer and Vision Transformer exhibited inferior performance when juxtaposed with DenseNet and DenseNetBL. Remarkably, among the shallow architectures, DenseNet33BL showcased superior aptitude for small-sample tree species classification, culminating in the most commendable results (Overall Accuracy (OA) = 0.901, Kappa = 0.892). Conversely, the Vision Transformer yielded the least favorable classification outcomes (OA = 0.767, Kappa = 0.708). The amalgamation of DenseNet33BL and simple linear iterative clustering emerged as the optimal strategy for attaining robust tree species area extraction results across two prototypical forests. In contrast, DenseNet121 exhibited suboptimal performance in the same forests, attaining the least satisfactory tree species area extraction results. These comprehensive findings underscore the efficacy of our DenseNetBL approach in addressing the challenges associated with small-sample tree species classification and accurate tree species area extraction.

10.
J Ambient Intell Humaniz Comput ; 14(7): 9217-9232, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36310644

RESUMEN

In computer vision segmentation field, super pixel identity has become an important index in the recently segmentation algorithms especially in medical images. Simple Linear Iterative Clustering (SLIC) algorithm is one of the most popular super pixel methods as it has a great robustness, less sensitive to the image type and benefit to the boundary recall in different kinds of image processing. Recently, COVID-19 severity increased with the lack of an effective treatment or vaccine. As the Corona virus spreads in an unknown manner, th-ere is a strong need for segmenting the lungs infected regions for fast tracking and early detection, no matter how small. This may consider difficult to be achieved with traditional segmentation techniques. From this perspective, this paper presents an efficient modified central force optimization (MCFO)-based SLIC segmentation algorithm to discuss chest CT images for detecting the positive COVID-19 cases. The proposed MCFO-based SLIC segmentation algorithm performance is evaluated and compared with the thresholding segmentation algorithm using different evaluation metrics such as accuracy, boundary recall, F-measure, similarity index, MCC, Dice, and Jaccard. The outcomes demonstrated that the proposed MCFO-based SLIC segmentation algorithm has achieved better detection for the small infected regions in CT lung scans than the thresholding segmentation.

11.
Methods Mol Biol ; 2633: 25-32, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36853453

RESUMEN

Molecular cloning is a routine technique for many laboratories with applications from genetic engineering to recombinant protein expression. While restriction-ligation cloning can be slow and inefficient, ligation-independent cloning uses long single-stranded overhangs generated by T4 DNA polymerase's 3' exonuclease activity to anneal the insert and plasmid vector prior to transformation. This chapter describes a fast, high-efficiency protocol for inserting one or more genes into a vector using sequence- and ligation-independent cloning (SLIC).


Asunto(s)
Ingeniería Genética , Vectores Genéticos , Clonación Molecular , Vectores Genéticos/genética , Laboratorios , Plásmidos/genética
12.
Neurocirugia (Astur : Engl Ed) ; 34(2): 80-86, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36754758

RESUMEN

OBJECTIVES: To compare the teachability of the Allen-Ferguson, Harris, Argenson, AOSpine, Subaxial Cervical Spine Injury Classification (SLIC), Subaxial Cervical Spine Injury Classification (CSISS) and to identify the classification that a group of residents and junior neurosurgeons find easiest to learn. METHODS: We used data from 64 consecutive patients. Answers of nine residents and junior neurosurgeons and four experienced surgeons in two assessment procedures were used. Six raters (workshop group) participated in special seminars between assessments. Three other raters formed the control group. Experienced surgeon's answers were used for comparison. Teachability was measured as the median value of the difference (ΔK) in the interrater agreement on the same patients by the same pairs of subjects. RESULTS: Median Δ K for the Allen-Ferguson, Harris, Argenson and AOSpine classifications were: (1) 0.01, 0.02, 0.29, and 0.39 for the workshop group; (2). 0.09, -0.03, 0.06 and 0.04 for the control group, respectively. Between numerical scales, median ΔK was higher for SLIC but did not exceed 0.16. Interrater consistency with expert's opinion was increased in the workshop group for Allen-Ferguson, Argenson and AOSpine and did not differ in either group for SLIC and CSISS. CONCLUSION: The AOSpine classification was the most teachable. Among numeric scales, SLIC demonstrated better results. The successful application of these classifications by residents and junior neurosurgeons was possible after a short educational course. The use of these scales in educational cycles at the stage of residency can significantly simplify the communication between specialists, especially at the stage of patient admission.


Asunto(s)
Internado y Residencia , Traumatismos del Cuello , Traumatismos Vertebrales , Humanos , Vértebras Cervicales/lesiones , Traumatismos Vertebrales/cirugía , Comunicación
13.
Comput Methods Programs Biomed ; 213: 106509, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34800805

RESUMEN

BACKGROUND AND OBJECTIVE: The schizophrenia diagnosis represents a difficult task because of the confusing descriptions of symptoms given by the patient, their similarity among several disorders, the lower familiarity with genetic predisposition, and the probably inadequate response to the treatment. Neuro-biological markers of schizophrenia, as a quantitative relationship between the psychiatrist's reports and the biology of the brain, could be used. Functional Magnetic Resonance Imaging (fMRI) obtain the subject's performance in cognitive tasks and may find significant differences between the patient's data and controls. The input data of classifiers may imply alterations in diagnosis; therefore, it is essential to ensure an adequate representation to describe the entire dataset classified. METHODS: We propose a supervoxels-based representation calculated by two main steps: the short-range connectivity, supervoxels' generation using a Fuzzy Iterative Clustering algorithm, and the long-range connectivity, employing Detrended Cross-Correlation Analysis among supervoxels. The unrelated supervoxels, through a statistical test based on critical points calculated empirically, are removed. The remainder supervoxels are the input for feature selectors to extract the discriminative supervoxels. We implement support vector machine classifiers using the correlation coefficient of the significant supervoxels. The dataset of 1.5 Tesla was downloaded from the SchizConnect site, where the fMRI data, during an auditory oddball task, was acquired. We calculate the performance of the classifiers using a leave-one-out cross-validation and compute the area under the Receiver Operating Characteristic curve and a permutation test to ensure no bias in the classifiers. RESULTS: According to the permutation test, with p-values less than the significance level of 0.05, the classifiers extract discriminative class structure from data where no bias is shown. Our supervoxels-based representation gets the maximum values of sensitivity, specificity, and accuracy of 92.9%, 100%, and 96.4%, respectively. The discriminative brain regions, to discern among patients and controls, are extracted; these regions also are mentioned by the related works. CONCLUSIONS: The proposed representation, based on supervoxels, is a data-driven model that does not use predefined models of the signal nor pre-relocated brain regions of interest. The results are competitive against the related works, and the relevant supervoxels are related to the schizophrenia diagnosis.


Asunto(s)
Imagen por Resonancia Magnética , Esquizofrenia , Encéfalo/diagnóstico por imagen , Mapeo Encefálico , Humanos , Esquizofrenia/diagnóstico por imagen , Máquina de Vectores de Soporte
14.
Front Neurosci ; 16: 1031524, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36408409

RESUMEN

High-precision segmentation of ancient mural images is the foundation of their digital virtual restoration. However, the complexity of the color appearance of ancient murals makes it difficult to achieve high-precision segmentation when using traditional algorithms directly. To address the current challenges in ancient mural image segmentation, an optimized method based on a superpixel algorithm is proposed in this study. First, the simple linear iterative clustering (SLIC) algorithm is applied to the input mural images to obtain superpixels. Then, the density-based spatial clustering of applications with noise (DBSCAN) algorithm is used to cluster the superpixels to obtain the initial clustered images. Subsequently, a series of optimized strategies, including (1) merging the small noise superpixels, (2) segmenting and merging the large noise superpixels, (3) merging initial clusters based on color similarity and positional adjacency to obtain the merged regions, and (4) segmenting and merging the color-mixing noisy superpixels in each of the merged regions, are applied to the initial cluster images sequentially. Finally, the optimized segmentation results are obtained. The proposed method is tested and compared with existing methods based on simulated and real mural images. The results show that the proposed method is effective and outperforms the existing methods.

15.
J Imaging ; 8(9)2022 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-36135409

RESUMEN

Fuzzy gray-level aura matrices have been developed from fuzzy set theory and the aura concept to characterize texture images. They have proven to be powerful descriptors for color texture classification. However, using them for color texture segmentation is difficult because of their high memory and computation requirements. To overcome this problem, we propose to extend fuzzy gray-level aura matrices to fuzzy color aura matrices, which would allow us to apply them to color texture image segmentation. Unlike the marginal approach that requires one fuzzy gray-level aura matrix for each color channel, a single fuzzy color aura matrix is required to locally characterize the interactions between colors of neighboring pixels. Furthermore, all works about fuzzy gray-level aura matrices consider the same neighborhood function for each site. Another contribution of this paper is to define an adaptive neighborhood function based on information about neighboring sites provided by a pre-segmentation method. For this purpose, we propose a modified simple linear iterative clustering algorithm that incorporates a regional feature in order to partition the image into superpixels. All in all, the proposed color texture image segmentation boils down to a superpixel classification using a simple supervised classifier, each superpixel being characterized by a fuzzy color aura matrix. Experimental results on the Prague texture segmentation benchmark show that our method outperforms the classical state-of-the-art supervised segmentation methods and is similar to recent methods based on deep learning.

16.
Global Spine J ; 11(1): 99-107, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32875837

RESUMEN

STUDY DESIGN: A multicenter observational survey. OBJECTIVE: To quantify and compare inter- and intraobserver reliability of the subaxial cervical spine injury classification (SLIC) and the cervical spine injury severity score (CSISS) in a multicentric survey of neurosurgeons with different experience levels. METHODS: Data concerning 64 consecutive patients who had undergone cervical spine surgery between 2013 and 2017 was evaluated, and we surveyed 37 neurosurgeons from 7 different clinics. All raters were divided into 3 groups depending on their level of experience. Two assessment procedures were performed. RESULTS: For the SLIC, we observed excellent agreement regarding management among experienced surgeons, whereas agreement among less experienced neurosurgeons was moderate and almost twice as unlikely. The sensitivity of SLIC relating to treatment tactics reached as high as 92.2%. For the CSISS, agreement regarding management ranged from medium to substantial, depending on a neurosurgeon's experience. For less experienced neurosurgeons, the level of agreement concerning surgical management was the same as for the SLIC in not exceeding a moderate level. However, this scale had insufficient sensitivity (slightly exceeding 50%). The reproducibility of both scales was excellent among all raters regardless of their experience level. CONCLUSIONS: Our study demonstrated better management reliability, sensitivity, and reproducibility for the SLIC, which provided moderate interrater agreement with moderate to excellent intraclass correlation coefficient indicators for all raters. The CSISS demonstrated high reproducibility; however, large variability in answers prevented raters from reaching a moderate level of agreement. Magnetic resonance imaging integration may increase sensitivity of CSISS in relation to fracture management.

17.
J Imaging ; 7(10)2021 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-34677288

RESUMEN

Electric Network Frequency (ENF) is embedded in multimedia recordings if the recordings are captured with a device connected to power mains or placed near the power mains. It is exploited as a tool for multimedia authentication. ENF fluctuates stochastically around its nominal frequency at 50/60 Hz. In indoor environments, luminance variations captured by video recordings can also be exploited for ENF estimation. However, the various textures and different levels of shadow and luminance hinder ENF estimation in static and non-static video, making it a non-trivial problem. To address this problem, a novel automated approach is proposed for ENF estimation in static and non-static digital video recordings. The proposed approach is based on the exploitation of areas with similar characteristics in each video frame. These areas, called superpixels, have a mean intensity that exceeds a specific threshold. The performance of the proposed approach is tested on various videos of real-life scenarios that resemble surveillance from security cameras. These videos are of escalating difficulty and span recordings from static ones to recordings, which exhibit continuous motion. The maximum correlation coefficient is employed to measure the accuracy of ENF estimation against the ground truth signal. Experimental results show that the proposed approach improves ENF estimation against the state-of-the-art, yielding statistically significant accuracy improvements.

18.
Methods Mol Biol ; 2247: 17-38, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33301110

RESUMEN

Most cellular processes are mediated by multi-subunit protein complexes which have attracted major interest in both academia and industry. Recombinant production of such entities in quantity and quality sufficient for functional and structural investigations may be extremely challenging and necessitate specific technologies. The baculovirus expression vector system is widely used for the production of eukaryotic multiprotein complexes, and a variety of strategies are available to assemble transfer vectors for the generation of recombinant baculoviruses. Here we detail applications of homology-based cloning techniques for one-step construction of dual promoter baculovirus transfer plasmids and of restriction-free (RF) cloning for the modification of existing constructs.


Asunto(s)
Baculoviridae/genética , Expresión Génica , Vectores Genéticos/genética , Complejos Multiproteicos/biosíntesis , Complejos Multiproteicos/genética , Proteínas Recombinantes , Secuencia de Bases , Línea Celular , Células Cultivadas , Clonación Molecular/métodos , Orden Génico , Complejos Multiproteicos/química , Plásmidos/genética , Regiones Promotoras Genéticas , Proteínas Recombinantes de Fusión
19.
Med Biol Eng Comput ; 57(3): 653-665, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30327998

RESUMEN

The analysis of cell characteristics from high-resolution digital histopathological images is the standard clinical practice for the diagnosis and prognosis of cancer. Yet, it is a rather exhausting process for pathologists to examine the cellular structures manually in this way. Automating this tedious and time-consuming process is an emerging topic of the histopathological image-processing studies in the literature. This paper presents a two-stage segmentation method to obtain cellular structures in high-dimensional histopathological images of renal cell carcinoma. First, the image is segmented to superpixels with simple linear iterative clustering (SLIC) method. Then, the obtained superpixels are clustered by the state-of-the-art clustering-based segmentation algorithms to find similar superpixels that compose the cell nuclei. Furthermore, the comparison of the global clustering-based segmentation methods and local region-based superpixel segmentation algorithms are also compared. The results show that the use of the superpixel segmentation algorithm as a pre-segmentation method improves the performance of the cell segmentation as compared to the simple single clustering-based segmentation algorithm. The true positive ratio (TPR), true negative ratio (TNR), F-measure, precision, and overlap ratio (OR) measures are utilized as segmentation performance evaluation. The computation times of the algorithms are also evaluated and presented in the study. Graphical Abstract The visual flowchart of the proposed automatic cell segmentation in histopathological images via two-staged superpixel-based algorithms.


Asunto(s)
Algoritmos , Carcinoma de Células Renales/patología , Técnicas de Preparación Histocitológica/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Neoplasias Renales/patología , Análisis por Conglomerados , Bases de Datos Factuales , Humanos
20.
Cureus ; 11(12): e6402, 2019 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-31970032

RESUMEN

Background The treatment of traumatic subaxial cervical spine injuries remains controversial. The American Spinal Injury Association (ASIA) impairment scale (AIS) is a widely-used metric to score neurological function after spinal cord injury (SCI). Here, we evaluated the outcomes of patients who underwent treatment of subaxial cervical spine injuries to identify predictors of neurologic function after injury and treatment. Methods We performed a retrospective logistic regression analysis to determine predictors of neurological outcome; 76 patients met the inclusion criteria and presented for a three-month follow-up. The mean age was 50.6±18.7 years old and the majority of patients were male (n=49, 64%). Results The majority of patients had stable AIS scores at three months (n=56, 74%). A subset of patients showed improvement at three months (n=16, 21%), while a small subset of patients had neurological decline at three months (n=4, 5%). In our model, increasing patient age (odds ratio [OR] 1.39, 1.10-2.61 95% confidence interval [CI], P<0.001) and a previous or current diagnosis of cancer (OR 22.4, 1.25-820 95% CI, P=0.04) significantly increased the odds of neurological decline at three months. In patients treated surgically, we found that delay in surgical treatment (>24 hours) was associated with a decreased odds of neurological improvement (OR 0.24, 0.05-0.99 95% CI, P=0.048). Cervical spine injuries are heterogeneous and difficult to manage. Conclusion We found that increasing patient age and an oncologic history were associated with neurological deterioration while a delay in surgical treatment was associated with decreased odds of improvement. These predictors of outcome may be used to guide prognosis and treatment decisions.

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