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Skull stripping is a crucial preprocessing step in magnetic resonance imaging (MRI), where experts manually create brain masks. This labor-intensive process heavily relies on the annotator's expertise, as automation faces challenges such as low tissue contrast, significant variations in image resolution, and blurred boundaries between the brain and surrounding tissues, particularly in rodents. In this study, we have developed a lightweight framework based on Swin-UNETR to automate the skull stripping process in MRI scans of mice and rats. The primary objective of this framework is to eliminate the need for preprocessing, reduce the workload, and provide an out-of-the-box solution capable of adapting to various MRI image resolutions. By employing a lightweight neural network, we aim to lower the performance requirements of the framework. To validate the effectiveness of our approach, we trained and evaluated the network using publicly available multi-center data, encompassing 1,037 rodents and 1,142 images from 89 centers, resulting in a preliminary mean Dice coefficient of 0.9914. The framework, data, and pre-trained models can be found on the following link: https://github.com/VitoLin21/Rodent-Skull-Stripping.
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Acting as a central hub in regulating brain functions, the thalamus plays a pivotal role in controlling high-order brain functions. Considering the impact of preterm birth on infant brain development, traditional studies focused on the overall development of thalamus other than its subregions. In this study, we compared the volumetric growth and shape development of the thalamic hemispheres between the infants born preterm and full-term (Left volume: P = 0.027, Left normalized volume: P < 0.0001; Right volume: P = 0.070, Right normalized volume: P < 0.0001). The ventral nucleus region, dorsomedial nucleus region, and posterior nucleus region of the thalamus exhibit higher vulnerability to alterations induced by preterm birth. The structural covariance (SC) between the thickness of thalamus and insula in preterm infants (Left: corrected P = 0.0091, Right: corrected P = 0.0119) showed significant increase as compared to full-term controls. Current findings suggest that preterm birth affects the development of the thalamus and has differential effects on its subregions. The ventral nucleus region, dorsomedial nucleus region, and posterior nucleus region of the thalamus are more susceptible to the impacts of preterm birth.
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Recien Nacido Prematuro , Imagen por Resonancia Magnética , Tálamo , Humanos , Tálamo/crecimiento & desarrollo , Tálamo/diagnóstico por imagen , Femenino , Masculino , Recién Nacido , Recien Nacido Prematuro/crecimiento & desarrollo , Nacimiento Prematuro/patologíaRESUMEN
Electroencephalography (EEG) has demonstrated significant value in diagnosing brain diseases. In particular, brain networks have gained prominence as they offer additional valuable insights by establishing connections between EEG signal channels. While brain connections are typically delineated by channel signal similarity, there lacks a consistent and reliable strategy for ascertaining node characteristics. Conventional node features such as temporal and frequency domain properties of EEG signals prove inadequate for capturing the extensive EEG information. In our investigation, we introduce a novel adaptive method for extracting node features from EEG signals utilizing a distinctive task-induced self-supervised learning technique. By amalgamating these extracted node features with fundamental edge features constructed using Pearson correlation coefficients, we showed that the proposed approach can function as a plug-in module that can be integrated to many common GNN networks (e.g., GCN, GraphSAGE, GAT) as a replacement of node feature selections module. Comprehensive experiments are then conducted to demonstrate the consistently superior performance and high generality of the proposed method over other feature selection methods in various of brain disorder prediction tasks, such as depression, schizophrenia, and Parkinson's disease. Furthermore, compared to other node features, our approach unveils profound spatial patterns through graph pooling and structural learning, shedding light on pivotal brain regions influencing various brain disorder prediction based on derived features.
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Encefalopatías , Electroencefalografía , Redes Neurales de la Computación , Aprendizaje Automático Supervisado , Humanos , Electroencefalografía/métodos , Encefalopatías/diagnóstico por imagen , Encefalopatías/fisiopatología , Procesamiento de Señales Asistido por Computador , Adulto , Encéfalo/diagnóstico por imagen , Encéfalo/fisiopatología , Masculino , FemeninoRESUMEN
The component analysis of raw meal is critical to the quality of cement. In recent years, near-infrared (NIR) has been emerged as an innovative and efficient analytical method to determine the oxide content of cement raw meal. This study aims to utilize NIR spectroscopy combined with machine learning and chemometrics to improve the prediction of oxide content in cement raw meal. The Savitzky-Golay convolution smoothing method is applied to eliminate noise interference for the analysis of calcium carbonate ( C a C O 3 ), silicon dioxide ( S i O 2 ), aluminum oxide ( A l 2 O 3 ), and ferric oxide ( F e 2 O 3 ) in cement raw materials. Different wavelength selection techniques are used to perform a comprehensive analysis of the model, comparing the performance of several wavelength selection techniques. The back-propagation neural network regression model based on particle swarm optimization algorithm was also applied to optimize the extracted and screened feature wavelengths, and the model prediction performance was checked and evaluated using R p and RMSE. In conclusion, the results indicate that NIR spectroscopy in combination with ML and chemometrics has great potential to effectively improve the prediction performance of oxide content in raw materials and highlight the importance of modeling and wavelength selection techniques. By enabling more accurate and efficient determination of oxide content in raw materials, NIR spectroscopy coupled with meta-modeling has the potential to revolutionize quality assurance practices in cement manufacturing.
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In pursuit of cultivating automated models for magnetic resonance imaging (MRI) to aid in diagnostics, an escalating demand for extensive, multisite, and heterogeneous brain imaging datasets has emerged. This potentially introduces biased outcomes when directly applied for subsequent analysis. Researchers have endeavored to address this issue by pursuing the harmonization of MRIs. However, most existing image-based harmonization methods for MRI are tailored for 2D slices, which may introduce inter-slice variations when they are combined into a 3D volume. In this study, we aim to resolve inconsistencies between slices by introducing a pseudo-warping field. This field is created randomly and utilized to transform a slice into an artificially warped subsequent slice. The objective of this pseudo-warping field is to ensure that generators can consistently harmonize adjacent slices to another domain, without being affected by the varying content present in different slices. Furthermore, we construct unsupervised spatial and recycle loss to enhance the spatial accuracy and slice-wise consistency across the 3D images. The results demonstrate that our model effectively mitigates inter-slice variations and successfully preserves the anatomical details of the images during the harmonization process. Compared to generative harmonization models that employ 3D operators, our model exhibits greater computational efficiency and flexibility.
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Encéfalo , Imagenología Tridimensional , Imagen por Resonancia Magnética , Imagen por Resonancia Magnética/métodos , Imagen por Resonancia Magnética/normas , Humanos , Imagenología Tridimensional/métodos , Encéfalo/diagnóstico por imagen , Algoritmos , Neuroimagen/métodos , Neuroimagen/normasRESUMEN
OBJECTIVES: This study aimed to investigate the in vitro effects of root canal filling and repair paste (nRoot BP) on human dental pulp stem cells (hDPSCs). METHODS: The effects of nRoot BP and iRoot BP Plus on the adhesion, proliferation, migration, and differentiation of hDPSCs were examined in vitro for 72 hours. The adhesion of cells was observed using immunofluorescence rhodamine ghost pen cyclic peptide staining and scanning electron microscopy (SEM). Cell density and changes in migration area were measured under a fluorescence inverted microscope. Fluorescent quantitative PCR was performed to detect genes related to odontogenesis and osteogenesis. RESULTS: Cells adhering to the surfaces of nRoot BP and iRoot BP Plus exhibited similar irregular polygonal morphologies, with cells extending irregular pseudopods to adhere to the materials. CCK-8 results indicated that the density of living cells for nRoot BP and iRoot BP Plus was lower than that of the blank control group at 3 and 5 days of culture. There was no significant difference in cell migration between the groups (P > .05). The migration ability of iRoot BP Plus and nRoot BP was similar to that of the control group. Both nRoot BP and iRoot BP Plus increased the expression of the RUNX2 gene, but there was no significant difference between the groups (P < .05). Furthermore, both nRoot BP and iRoot BP Plus downregulated the expression of the DSPP gene, with no significant difference between them (P > .05). CONCLUSIONS: nRoot BP exhibited a slight inhibition of hDPSC proliferation but did not affect the adhesion and migration of hDPSCs. The impact of nRoot BP on the osteogenic and odontogenic differentiation of hDPSCs was similar to that of iRoot BP Plus.
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Adhesión Celular , Diferenciación Celular , Movimiento Celular , Proliferación Celular , Cerámica , Pulpa Dental , Materiales de Obturación del Conducto Radicular , Células Madre , Humanos , Pulpa Dental/citología , Pulpa Dental/efectos de los fármacos , Células Madre/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Adhesión Celular/efectos de los fármacos , Materiales de Obturación del Conducto Radicular/farmacología , Nanopartículas , Osteogénesis/efectos de los fármacos , Microscopía Electrónica de Rastreo , Células Cultivadas , Combinación de Medicamentos , Subunidad alfa 1 del Factor de Unión al Sitio Principal , Técnicas In Vitro , Odontogénesis/efectos de los fármacos , Materiales Biocompatibles/farmacología , SilicatosRESUMEN
Alzheimer's disease (AD) is a prevalent neurodegenerative disorder characterized by the progressive cognitive decline. Among the various clinical symptoms, neuropsychiatric symptoms (NPS) commonly occur during the course of AD. Previous researches have demonstrated a strong association between NPS and severity of AD, while the research methods are not sufficiently intuitive. Here, we report a hybrid deep learning framework for AD diagnosis using multimodal inputs such as structural MRI, behavioral scores, age, and gender information. The framework uses a 3D convolutional neural network to automatically extract features from MRI. The imaging features are passed to the Principal Component Analysis for dimensionality reduction, which fuse with non-imaging information to improve the diagnosis of AD. According to the experimental results, our model achieves an accuracy of 0.91 and an area under the curve of 0.97 in the task of classifying AD and cognitively normal individuals. SHapley Additive exPlanations are used to visually exhibit the contribution of specific NPS in the proposed model. Among all behavioral symptoms, apathy plays a particularly important role in the diagnosis of AD, which can be considered a valuable factor in further studies, as well as clinical trials.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Aprendizaje Profundo , Humanos , Enfermedad de Alzheimer/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Redes Neurales de la Computación , Disfunción Cognitiva/diagnóstico por imagen , Neuroimagen/métodosRESUMEN
BACKGROUND: Cerebellopontine angle lipoma is a rare tumor that composes less than 1% of all CPA tumors. There has been no recorded case of unilateral CPA/IAC lipoma with sudden contralateral deafness yet. CASE PRESENTATION: We report a 52-year-old man diagnosed with right cerebellopontine angle lipoma and combined left total deafness. Pure-tone audiometry revealed total sensorineural deafness in his left ear and moderate sensorineural deafness in the right ear. The patient was treated with glucocorticoids, batroxobin, and other symptomatic treatments. There was no substantial improvement in hearing after 14 days' treatment. DISCUSSION: We chose conservative treatment for him. It is advised to wear hearing aids in the right ear and to undergo regular imaging monitoring. CONCLUSION: Treatment options for such patients should be chosen by taking into account the degree of bilateral hearing loss, the size and location of the tumor, the possibility of preserving hearing during surgery, the functional level of the patient's facial nerve, and other factors.
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Fruit detection and recognition has an important impact on fruit and vegetable harvesting, yield prediction and growth information monitoring in the automation process of modern agriculture, and the actual complex environment of orchards poses some challenges for accurate fruit detection. In order to achieve accurate detection of green fruits in complex orchard environments, this paper proposes an accurate object detection method for green fruits based on optimized YOLOX_m. First, the model extracts features from the input image using the CSPDarkNet backbone network to obtain three effective feature layers at different scales. Then, these effective feature layers are fed into the feature fusion pyramid network for enhanced feature extraction, which combines feature information from different scales, and in this process, the Atrous spatial pyramid pooling (ASPP) module is used to increase the receptive field and enhance the network's ability to obtain multi-scale contextual information. Finally, the fused features are fed into the head prediction network for classification prediction and regression prediction. In addition, Varifocal loss is used to mitigate the negative impact of unbalanced distribution of positive and negative samples to obtain higher precision. The experimental results show that the model in this paper has improved on both apple and persimmon datasets, with the average precision (AP) reaching 64.3% and 74.7%, respectively. Compared with other models commonly used for detection, the model approach in this study has a higher average precision and has improved in other performance metrics, which can provide a reference for the detection of other fruits and vegetables.
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In recent years, deep learning has shown very competitive performance in seizure detection. However, most of the currently used methods either convert electroencephalogram (EEG) signals into spectral images and employ 2D-CNNs, or split the one-dimensional (1D) features of EEG signals into many segments and employ 1D-CNNs. Moreover, these investigations are further constrained by the absence of consideration for temporal links between time series segments or spectrogram images. Therefore, we propose a Dual-Modal Information Bottleneck (Dual-modal IB) network for EEG seizure detection. The network extracts EEG features from both time series and spectrogram dimensions, allowing information from different modalities to pass through the Dual-modal IB, requiring the model to gather and condense the most pertinent information in each modality and only share what is necessary. Specifically, we make full use of the information shared between the two modality representations to obtain key information for seizure detection and to remove irrelevant feature between the two modalities. In addition, to explore the intrinsic temporal dependencies, we further introduce a bidirectional long-short-term memory (BiLSTM) for Dual-modal IB model, which is used to model the temporal relationships between the information after each modality is extracted by convolutional neural network (CNN). For CHB-MIT dataset, the proposed framework can achieve an average segment-based sensitivity of 97.42%, specificity of 99.32%, accuracy of 98.29%, and an average event-based sensitivity of 96.02%, false detection rate (FDR) of 0.70/h. We release our code at https://github.com/LLLL1021/Dual-modal-IB.
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Aprendizaje Profundo , Humanos , Procesamiento de Señales Asistido por Computador , Convulsiones/diagnóstico , Electroencefalografía/métodos , Redes Neurales de la ComputaciónRESUMEN
Fruit and vegetable picking robots are affected by the complex orchard environment, resulting in poor recognition and segmentation of target fruits by the vision system. The orchard environment is complex and changeable. For example, the change of light intensity will lead to the unclear surface characteristics of the target fruit; the target fruits are easy to overlap with each other and blocked by branches and leaves, which makes the shape of the fruits incomplete and difficult to accurately identify and segment one by one. Aiming at various difficulties in complex orchard environment, a two-stage instance segmentation method based on the optimized mask region convolutional neural network (mask RCNN) was proposed. The new model proposed to apply the lightweight backbone network MobileNetv3, which not only speeds up the model but also greatly improves the accuracy of the model and meets the storage resource requirements of the mobile robot. To further improve the segmentation quality of the model, the boundary patch refinement (BPR) post-processing module is added to the new model to optimize the rough mask boundaries of the model output to reduce the error pixels. The new model has a high-precision recognition rate and an efficient segmentation strategy, which improves the robustness and stability of the model. This study validates the effect of the new model using the persimmon dataset. The optimized mask RCNN achieved mean average precision (mAP) and mean average recall (mAR) of 76.3 and 81.1%, respectively, which are 3.1 and 3.7% improvement over the baseline mask RCNN, respectively. The new model is experimentally proven to bring higher accuracy and segmentation quality and can be widely deployed in smart agriculture.
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Epilepsy is a neurological disorder caused by brain dysfunction, which could cause uncontrolled behavior, loss of consciousness and other hazards. Electroencephalography (EEG) is an indispensable auxiliary tool for clinical diagnosis. Great progress has been made by current seizure identification methods. However, the performance of the methods on different patients varies a lot. In order to deal with this problem, we propose an automatic seizure identification method based on brain connectivity learning. The connectivity of different brain regions is modeled by a graph. Different from the manually defined graph structure, our method can extract the optimal graph structure and EEG features in an end-to-end manner. Combined with the popular graph attention neural network (GAT), this method achieves high performance and stability on different patients from the CHB-MIT dataset. The average values of accuracy, sensitivity, specificity, F1-score and AUC of the proposed model are 98.90%, 98.33%, 98.48%, 97.72% and 98.54%, respectively. The standard deviations of the above five indicators are 0.0049, 0.0125, 0.0116 and 0.0094, respectively. Compared with the existing seizure identification methods, the stability of the proposed model is improved by 78-95%.
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Electroencefalografía , Epilepsia , Humanos , Electroencefalografía/métodos , Convulsiones/diagnóstico , Encéfalo , Redes Neurales de la Computación , AlgoritmosRESUMEN
Accurate detection and segmentation of the object fruit is the key part of orchard production measurement and automated picking. Affected by light, weather, and operating angle, it brings new challenges to the efficient and accurate detection and segmentation of the green object fruit under complex orchard backgrounds. For the green fruit segmentation, an efficient YOLOF-snake segmentation model is proposed. First, the ResNet101 structure is adopted as the backbone network to achieve feature extraction of the green object fruit. Then, the C5 feature maps are expanded with receptive fields and the decoder is used for classification and regression. Besides, the center point in the regression box is employed to get a diamond-shaped structure and fed into an additional Deep-snake network, which is adjusted to the contours of the target fruit to achieve fast and accurate segmentation of green fruit. The experimental results show that YOLOF-snake is sensitive to the green fruit, and the segmentation accuracy and efficiency are significantly improved. The proposed model can effectively extend the application of agricultural equipment and provide theoretical references for other fruits and vegetable segmentation.
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BACKGROUND: Mild cognitive impairment (MCI) individuals with neuropsychiatric symptoms (NPS) are more likely to develop dementia. OBJECTIVE: We sought to understand the relationship between neuroimaging markers such as tau pathology and cognitive symptoms both with and without the presence of NPS during the prodromal period of Alzheimer's disease. METHODS: A total of 151 MCI subjects with tau positron emission tomographic (PET) scanning with 18F AV-1451, amyloid-ß (Aß) PET scanning with florbetapir or florbetaben, magnetic resonance imaging, and cognitive and behavioral evaluations were selected from the Alzheimer's Disease Neuroimaging Initiative. A 4-group division approach was proposed using amyloid (A-/A+) and behavior (B-/B+) status: A-B-, A-B+, A+B-, and A+B+. Pearson's correlation test was conducted for each group to examine the association between tau deposition and cognitive performance. RESULTS: No statistically significant association between tau deposition and cognitive impairment was found for subjects without behavior symptoms in either the A-B-or A+B-groups after correction for false discovery rate. In contrast, tau deposition was found to be significantly associated with cognitive impairment in entorhinal cortex and temporal pole for the A-B+ group and nearly the whole cerebrum for the A+B+ group. CONCLUSION: Enhanced associations between tauopathy and cognitive impairment are present in MCI subjects with behavior symptoms, which is more prominent in the presence of elevated amyloid pathology. MCI individuals with NPS may thus be at greater risk for further cognitive decline with the increase of tau deposition in comparison to those without NPS.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides , Disfunción Cognitiva/psicología , Humanos , Tomografía de Emisión de Positrones/métodos , Proteínas tauRESUMEN
Premature birth is associated with a high prevalence of neurodevelopmental impairments in surviving infants. The hippocampus is known to be critical for learning and memory, yet the putative effects of hippocampal dysfunction remain poorly understood in preterm neonates. In particular, while asymmetry of the hippocampus has been well noted both structurally and functionally, how preterm birth impairs hippocampal development and to what extent the hippocampus is asymmetrically impaired by preterm birth have not been well delineated. In this study, we compared volumetric growth and shape development in the hippocampal hemispheres and structural covariance (SC) between hippocampal vertices and cortical thickness in cerebral cortex regions between two groups. We found that premature infants had smaller volumes of the right hippocampi only. Lower thickness was observed in the hippocampal head in both hemispheres for preterm neonates compared with full-term peers, though preterm neonates exhibited an accelerated age-related change of hippocampal thickness in the left hippocampi. The SC between the left hippocampi and the limbic lobe of the premature infants was severely impaired compared with the term-born neonates. These findings suggested that the development of the hippocampus during the third trimester may be altered following early extrauterine exposure with a high degree of asymmetry.
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Nacimiento Prematuro , Corteza Cerebral , Femenino , Hipocampo/diagnóstico por imagen , Humanos , Lactante , Recién Nacido , Recien Nacido Prematuro , Imagen por Resonancia MagnéticaRESUMEN
RADA16-I is an ion-complementary self-assembled peptide with a regular folded secondary conformation and can be assembled into an ordered nanostructure. Dentonin is an extracellular matrix phosphate glycoprotein functional peptide motif-containing RGD and SGDG motifs. In this experiment, we propose to combine RAD and Dentonin to form a functionalized self-assembled peptide RAD/Dentonin hydrogel scaffold. Furthermore, we expect that the RAD with the addition of functional motif Dentonin can promote pulp regeneration. The study analyzed the physicochemical properties of RAD/Dentonin through circular dichroism, morphology scanning, and rheology. Besides, we examined the scaffold's biocompatibility by immunofluorescent staining, CCK-8 method, Live/Dead fluorescent staining, and 3D reconstruction. Finally, we applied ALP activity assay, RT-qPCR, and Alizarin red S staining to detect the effect of RAD/Dentonin on the odontogenic differentiation of human dental pulp stem cells (hDPSCs). The results showed that RAD/Dentonin spontaneously assembles into a hydrogel with aß-sheet-based nanofiber network structure.In vitro, RAD/Dentonin has superior biocompatibility and enhances adhesive proliferation, migration, odontogenic differentiation, and mineralization deposition of hDPSCs. In conclusion, the novel self-assembled peptide RAD/Dentonin is a new scaffold material suitable for cell culture and has promising applications as a scaffold for endodontic tissue engineering.
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Pulpa Dental , Hidrogeles , Diferenciación Celular , Proliferación Celular , Células Cultivadas , Humanos , Hidrogeles/química , Péptidos/química , Regeneración , Andamios del Tejido/químicaRESUMEN
Objective: To delineate the relationship between clinical symptoms and tauopathy of the hippocampal subfields under different amyloid statuses. Methods: One hundred and forty-three subjects were obtained from the ADNI project, including 87 individuals with normal cognition, 46 with mild cognitive impairment, and 10 with Alzheimer's disease (AD). All subjects underwent the tau PET, amyloid PET, T1W, and high-resolution T2W scans. Clinical symptoms were assessed by the Neuropsychiatric Inventory (NPI) total score and Alzheimer's Disease Assessment Scale cognition 13 (ADAS-cog-13) total score, comprising memory and executive function scores. The hippocampal subfields including Cornu Ammonis (CA1-3), subiculum (Sub), and dentate gyrus (DG), as well as the adjacent para-hippocampus (PHC) and entorhinal cortex (ERC), were segmented automatically using the Automatic Segmentation of Hippocampal Subfields (ASHS) software. The relationship between tauopathy/volume of the hippocampal subfields and assessment scores was calculated using partial correlation analysis under different amyloid status, by controlling age, gender, education, apolipoprotein E (APOE) allele É4 carrier status, and, time interval between the acquisition time of tau PET and amyloid PET scans. Results: Compared with amyloid negative (A-) group, individuals from amyloid positive (A+) group are more impaired based on the Mini-mental State Examination (MMSE; p = 3.82e-05), memory (p = 6.30e-04), executive function (p = 0.0016), and ADAS-cog-13 scores (p = 5.11e-04). Significant decrease of volume (CA1, DG, and Sub) and increase of tau deposition (CA1, Sub, ERC, and PHC) of the hippocampal subfields of both hemispheres were observed for the A+ group compared to the A- group. Tauopathy of ERC is significantly associated with memory score for the A- group, and the associated regions spread into Sub and PHC for the A+ group. The relationship between the impairment of behavior or executive function and tauopathy of the hippocampal subfield was discovered within the A+ group. Leftward asymmetry was observed with the association between assessment scores and tauopathy of the hippocampal subfield, which is more prominent for the NPI score for the A+ group. Conclusion: The associations of tauopathy/volume of the hippocampal subfields with clinical symptoms provide additional insight into the understanding of local changes of the human HF during the AD continuum and can be used as a reference for future studies.
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During the early second trimester, the cortical plate, or "the developing cortex", undergoes immensely complex and rapid development to complete its major complement of neurons. However, morphological development of the cortical plate and the precise patterning of brain structural covariance networks during this period remain unexplored. In this study, we used 7.0 T high-resolution magnetic resonance images of brain specimens ranging from 14 to 22 gestational weeks to manually segment the cortical plate. Thickness, area expansion, and curvature (i.e., folding) across the cortical plate regions were computed, and correlations of thickness values among different cortical plate regions were measured to analyze fetal cortico-cortical structural covariance throughout development of the early second trimester. The cortical plate displayed significant increases in thickness and expansions in area throughout all regions but changes of curvature in only certain major sulci. The topological architecture and network properties of fetal brain covariance presented immature and inefficient organizations with low degree of integration and high degree of segregation. Altogether, our results provide novel insight on the developmental patterning of cortical plate thickness and the developmental origin of brain network architecture throughout the early second trimester.
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Corteza Cerebral/anatomía & histología , Corteza Cerebral/embriología , Red Nerviosa/anatomía & histología , Red Nerviosa/embriología , Adulto , Femenino , Desarrollo Fetal , Feto , Humanos , Imagen por Resonancia Magnética , Masculino , Embarazo , Segundo Trimestre del Embarazo , Caracteres SexualesRESUMEN
In this study, a novel intelligent nanoplatform to integrate multiple imaging and therapeutic functions for targeted cancer theranostics. The nanoplatform, DOX@Gd-MFe3O4 NPs, was constructed Gd-doped mesoporous Fe3O4 nanoparticles following with the doxorubicin (DOX) loading in the mesopores of the NPs. The DOX@Gd-MFe3O4 NPs exhibited good properties in colloidal dispersity, photothermal conversion, NIR triggered drug release, and high T1/T2 relaxicity rate (r1=9.64 mM-1s-1, r2= 177.71 mM-1s-1). Benefiting from the high MR contrast, DOX@Gd-MFe3O4 NPs enabled simultaneous T1/T2 dual-modal MR imagining on 4T1 bearing mice in vivo and the MR contrast effect was further strengthened by external magnetic field. In addition, the DOX@Gd-MFe3O4 NPs revealed the strongest inhibition to the growth of 4T1 in vitro and in vivo under NIR irradiation and guidance of external magnetic field. Moreover, biosafety was also validated by in vitro and in vivo tests. Thus, the prepared DOX@Gd-MFe3O4 NPs would provide a promising intelligent nanoplatform for dual-modal MR imagining guided synergistic therapy in cancer theranostics.
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Antibióticos Antineoplásicos/administración & dosificación , Doxorrubicina/administración & dosificación , Nanopartículas Magnéticas de Óxido de Hierro/química , Imagen por Resonancia Magnética Intervencional/métodos , Neoplasias/tratamiento farmacológico , Animales , Antibióticos Antineoplásicos/farmacología , Línea Celular Tumoral , Medios de Contraste/química , Doxorrubicina/farmacología , Portadores de Fármacos , Sistemas de Liberación de Medicamentos , Liberación de Fármacos , Gadolinio/química , RatonesRESUMEN
According to the latest Braak staging of Alzheimer's disease (AD), tau pathology occurs earliest in the brain in the locus coeruleus (LC) of the brainstem, then propagates to the transentorhinal cortex (TEC), and later to other neocortical regions. Recent animal and in vivo human brain imaging research also support the trans-axonal propagation of tau pathology. In addition, neurochemical studies link norepinephrine to behavioral symptoms in AD. It is thus critical to examine the integrity of the LC-TEC pathway in studying the early development of the disease, but there has been limited work in this direction. By leveraging the high-resolution and multi-shell diffusion MRI data from the Human Connectome Project (HCP), in this work we develop a novel method for the reconstruction of the LC-TEC pathway in a cohort of 40 HCP subjects carefully selected based on rigorous quality control of the residual distortion artifacts in the brainstem. A probabilistic atlas of the LC-TEC pathway of both hemispheres is then developed in the MNI152 space and distributed publicly on the NITRC website. To apply our atlas on clinical imaging data, we develop an automated approach to calculate the medial core of the LC-TEC pathway for localized analysis of connectivity changes. In a cohort of 138 subjects from the Alzheimer's Disease Neuroimaging Initiative (ADNI), we demonstrate the detection of the decreased fiber integrity in the LC-TEC pathways with increasing disease severity.