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1.
Nature ; 624(7992): 611-620, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37907096

RESUMEN

Ageing is a critical factor in spinal-cord-associated disorders1, yet the ageing-specific mechanisms underlying this relationship remain poorly understood. Here, to address this knowledge gap, we combined single-nucleus RNA-sequencing analysis with behavioural and neurophysiological analysis in non-human primates (NHPs). We identified motor neuron senescence and neuroinflammation with microglial hyperactivation as intertwined hallmarks of spinal cord ageing. As an underlying mechanism, we identified a neurotoxic microglial state demarcated by elevated expression of CHIT1 (a secreted mammalian chitinase) specific to the aged spinal cords in NHP and human biopsies. In the aged spinal cord, CHIT1-positive microglia preferentially localize around motor neurons, and they have the ability to trigger senescence, partly by activating SMAD signalling. We further validated the driving role of secreted CHIT1 on MN senescence using multimodal experiments both in vivo, using the NHP spinal cord as a model, and in vitro, using a sophisticated system modelling the human motor-neuron-microenvironment interplay. Moreover, we demonstrated that ascorbic acid, a geroprotective compound, counteracted the pro-senescent effect of CHIT1 and mitigated motor neuron senescence in aged monkeys. Our findings provide the single-cell resolution cellular and molecular landscape of the aged primate spinal cord and identify a new biomarker and intervention target for spinal cord degeneration.


Asunto(s)
Senescencia Celular , Quitinasas , Microglía , Neuronas Motoras , Primates , Médula Espinal , Animales , Humanos , Biomarcadores/metabolismo , Quitinasas/metabolismo , Microglía/enzimología , Microglía/metabolismo , Microglía/patología , Neuronas Motoras/metabolismo , Enfermedades Neuroinflamatorias/metabolismo , Enfermedades Neuroinflamatorias/patología , Primates/metabolismo , Reproducibilidad de los Resultados , Análisis de Expresión Génica de una Sola Célula , Médula Espinal/metabolismo , Médula Espinal/patología
2.
Methods ; 205: 220-225, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35809769

RESUMEN

U-Net has achieved great success in the task of medical image segmentation. It encodes and extracts information from several convolution blocks, and then decodes the feature maps to get the segmentation results. Our experiments show that in a multi-scale medical segmentation task, excessive downsampling will cause the model to ignore the small segmentation objects and thus fail to complete the segmentation task. In this work, we propose a more complete method Double-branch U-Net (2BUNet) to solve the multi-scale organ segmentation challenge. Our model is divided into four parts: main branch, tributary branch, information exchange module and classification module. The main advantages of the new model consist of: (1) Extracting information to improve model decoding capabilities using the complete encoding structure. (2) The information exchange module is added to the main branch and tributaries to provide regularization for the model, so as to avoid the large gap between the two paths. (3) Main branch structure for extracting major features of large organ. (4) The tributary structure is used to enlarge the image to extract the microscopic characteristics of small organ. (5) A classification assistant module is proposed to increase the class constraint for the output tensor. The comparative experiments show that our method achieves state-of-the-art performances in real scenes.


Asunto(s)
Diagnóstico por Imagen , Procesamiento de Imagen Asistido por Computador , Redes Neurales de la Computación , Diagnóstico por Imagen/métodos , Procesamiento de Imagen Asistido por Computador/métodos
3.
BMC Ophthalmol ; 23(1): 368, 2023 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-37674121

RESUMEN

BACKGROUND: Maresin-1 plays an important role in diabetic illnesses and ferroptosis is associated with pathogenic processes of diabetic retinopathy (DR). The goal of this study is to explore the influence of maresin-1 on ferroptosis and its molecular mechanism in DR. METHODS: ARPE-19 cells were exposed to high glucose (HG) condition for developing a cellular model of DR. The CCK-8 assay and flow cytometry were used to assess ARPE-19 cell proliferation and apoptosis, respectively. Furthermore, the GSH content, MDA content, ROS level, and Fe2+ level were measured by using a colorimetric GSH test kit, a Lipid Peroxidation MDA Assay Kit, a DCFH-DA assay and the phirozine technique, respectively. Immunofluorescence labelling was used to detect protein levels of ACSL4 and PTGS2. Messenger RNA and protein expression of HO-1, GPX4 and Nrf2 was evaluated through western blotting and quantitative real time-polymerase chain reaction (qRT-PCR). To establish a diabetic mouse model, mice were intraperitoneally injected 150 mg/kg streptozotocin. The MDA content, ROS level and the iron level were detected by using corresponding commercial kits. RESULTS: Maresin-1 promoted cell proliferation while reducing the apoptotic process in HG-induced ARPE-19 cells. Maresin-1 significantly reduced ferroptosis induced by HG in ARPE-19 cells, as demonstrated as a result of decreased MDA content, ROS level, Fe2+ level, PTGS2 expression, ACSL4 expression and increased GSH content. With respect to mechanisms, maresin-1 treatment up-regulated the mRNA expression and protein expression of HO-1, GPX4 and Nrf2 in HG-induced ARPE-19 cells. Nrf2 inhibitor reversed the inhibitory effects of maresin-1 on ferroptosis in HG-induced ARPE-19 cells. In vivo experiments, we found that Maresin-1 evidently repressed ferroptosis a mouse model of DR, as evidenced by the decreased MDA content, ROS level and iron level in retinal tissues of mice. CONCLUSION: Maresin-1 protects ARPE cells from HG-induced ferroptosis via activating the Nrf2/HO-1/GPX4 pathway, suggesting that maresin-1 prevents DR development.


Asunto(s)
Retinopatía Diabética , Ferroptosis , Animales , Ratones , Factor 2 Relacionado con NF-E2 , Ciclooxigenasa 2 , Especies Reactivas de Oxígeno , Modelos Animales de Enfermedad , Glucosa/farmacología , Hierro
4.
Eur Neurol ; 86(4): 229-241, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37068471

RESUMEN

INTRODUCTION: Currently, it is still controversial to treat stroke with ticagrelor alone. The purpose of our study was to systematically review and analyze the efficacy and safety of ticagrelor on cerebrovascular outcomes in patients with vascular risk factors. METHODS: The PubMed, Cochrane Library, and Embase databases were systematically searched using the keywords stroke, ticagrelor, clopidogrel, and aspirin to identify randomized controlled trials (RCTs). Primary outcomes included reported stroke, ischemic stroke, and complex events; the secondary outcome was hemorrhagic stroke. The safety outcomes included major bleeding events, major or minor bleeding, and intracranial bleeding. The pooled odds ratio (OR), hazard ratios (HRs), and 95% confidence interval (CI) were calculated. We used I2 statistics to assess statistical heterogeneity. RESULTS: This meta-analysis included 15 RCTs involving 63,865 patients. Compared to the control group, ticagrelor reduced the risk of stroke (OR: 0.90; 95% CI: 0.81-0.99, p = 0.03; I2 = 3%), ischemic stroke (OR: 0.81; 95% CI: 0.74-0.90, p < 0.0001; I2 = 0%). Ticagrelor was not associated with an increased risk of all-cause mortality (OR: 0.94; 95% CI: 0.84-1.06, p = 0.31; I2 = 62%), major bleeding (OR: 1.06; 95% CI: 0.97-1.15, p = 0.20; I2 = 17%), hemorrhagic strokes (OR: 1.22, 95% CI: 0.76-1.96, p = 0.41; I2 = 0%), and intracranial hemorrhage (OR: 1.06; 95% CI: 0.78-1.43, p = 0.71; I2 = 12%). There was an increased risk of major or minor bleeding with ticagrelor compared to the control group (OR: 1.40; 95% CI: 1.19-1.66, p < 0.0001; I2 = 56%). Additional analyses demonstrated that ticagrelor reduced the risk of incident recurrent stroke (HR: 0.83; 95% CI: 0.75-0.93, p = 0.0009; I2 = 0%), recurrent ischemic stroke (HR: 0.79; 95% CI: 0.71-0.89, p < 0.0001; I2 = 0%) among patients with a history of acute ischemic stroke (AIS) or transient ischemic attack (TIA). There were no significant differences in safety outcomes. CONCLUSION: Ticagrelor is slightly better than clopidogrel and aspirin in preventing stroke, especially ischemic stroke, with significant safety risks. For patients with a history of AIS/TIA, the use of ticagrelor was superior to the use of clopidogrel or aspirin in reducing the risk of subsequent stroke. We believe that ticagrelor is a potential alternative to aspirin or clopidogrel in some cases, especially for patients with CYP2C19 deficiency.


Asunto(s)
Ataque Isquémico Transitorio , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Aspirina/efectos adversos , Clopidogrel/uso terapéutico , Ticagrelor/uso terapéutico , Ataque Isquémico Transitorio/complicaciones , Inhibidores de Agregación Plaquetaria/efectos adversos , Quimioterapia Combinada , Accidente Cerebrovascular/complicaciones , Hemorragia/inducido químicamente , Hemorragia/complicaciones , Hemorragia/tratamiento farmacológico , Hemorragias Intracraneales/complicaciones , Resultado del Tratamiento
5.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 40(2): 257-264, 2023 Apr 25.
Artículo en Zh | MEDLINE | ID: mdl-37139756

RESUMEN

Macaque is a common animal model in drug safety assessment. Its behavior reflects its health condition before and after drug administration, which can effectively reveal the side effects of drugs. At present, researchers usually rely on artificial methods to observe the behavior of macaque, which cannot achieve uninterrupted 24-hour monitoring. Therefore, it is urgent to develop a system to realize 24-hour observation and recognition of macaque behavior. In order to solve this problem, this paper constructs a video dataset containing nine kinds of macaque behaviors (MBVD-9), and proposes a network called Transformer-augmented SlowFast for macaque behavior recognition (TAS-MBR) based on this dataset. Specifically, the TAS-MBR network converts the red, green and blue (RGB) color mode frame input by its fast branches into residual frames on the basis of SlowFast network and introduces the Transformer module after the convolution operation to obtain sports information more effectively. The results show that the average classification accuracy of TAS-MBR network for macaque behavior is 94.53%, which is significantly improved compared with the original SlowFast network, proving the effectiveness and superiority of the proposed method in macaque behavior recognition. This work provides a new idea for the continuous observation and recognition of the behavior of macaque, and lays the technical foundation for the calculation of monkey behaviors before and after medication in drug safety evaluation.


Asunto(s)
Suministros de Energía Eléctrica , Macaca , Animales , Reconocimiento en Psicología
6.
Bioconjug Chem ; 26(12): 2530-41, 2015 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-26554699

RESUMEN

Theranostic tantalum oxide nanoparticles (TaOxNPs) of about 40 nm were successfully developed by conjugating functional molecules including polyethylene glycol (PEG), near-infrared (NIR) fluorescent dye, doxorubicin (DOX), and hyaluronic acid (HA) onto the surface of the nanoparticles (TaOx@Cy7-DOX-PEG-HA NPs) for actively targeting delivery, pH-responsive drug release, and NIR fluorescence/X-ray CT bimodal imaging. The obtained nanoagent exhibits good biocompatibility, high cumulative release rate in the acidic microenvironments, long blood circulation time, and superior tumor-targeting ability. Both in vitro and in vivo experiments show that it can serve as an excellent contrast agent to simultaneously enhance fluorescence imaging and CT imaging greatly. Most importantly, such a nanoagent could enhance the therapeutic efficacy of the tumor greatly and the tumor growth inhibition was evaluated to be 87.5%. In a word, multifunctional TaOx@Cy7-DOX-PEG-HA NPs can serve as a theranostic nanomedicine for fluorescence/X-ray CT bimodal imaging, remote-controlled therapeutics, enabling personalized detection, and treatment of cancer with high efficacy.


Asunto(s)
Antibióticos Antineoplásicos/administración & dosificación , Doxorrubicina/administración & dosificación , Ácido Hialurónico/química , Nanopartículas/química , Neoplasias/diagnóstico , Neoplasias/tratamiento farmacológico , Óxidos/química , Tantalio/química , Animales , Antibióticos Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Doxorrubicina/uso terapéutico , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos , Humanos , Ratones , Imagen Óptica , Nanomedicina Teranóstica
7.
Cyborg Bionic Syst ; 5: 0089, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38550252

RESUMEN

Over time, the utilization of the Underwater Vehicle-Manipulator System (UVMS) has steadily increased in exploring and harnessing marine resources. However, the underwater environment poses big challenges for controlling, navigating, and communicating with UVMS. These challenges have not only spurred the continuous advancement of related technologies, but also made the development of the UVMS even more captivating. This article firstly provides a review of development status of the UVMS and discusses the current limitations and future directions, and then reviews in detail the dynamic and hydrodynamic modeling methods, and analyzes the principles, advantages, and disadvantages of various approaches. Then, we try to review 2 key technologies of operation control methods, including underwater positioning and navigation technologies and vehicle-manipulator coordinated control approaches. Finally, a reasonable prospect for the future development of UVMS is given.

8.
Appl Opt ; 52(11): 2374-84, 2013 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-23670769

RESUMEN

Determining an appropriate regularization parameter is often challenging work because it has a narrow range and varies with problems, which is likely to lead to large reconstruction errors. In this contribution, an adaptive regularized method based on homotopy is presented for sparse fluorescence tomography reconstruction. Due to the adaptive regularization strategy, the proposed method is always able to reconstruct sources accurately independent of the estimation of the regularization parameter. Moreover, the proposed method is about two orders of magnitude faster than the two contrasting methods. Numerical and in vivo mouse experiments have been employed to validate the robustness and efficiency of the proposed method.


Asunto(s)
Algoritmos , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Microscopía Fluorescente/métodos , Tomografía Óptica/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
9.
Appl Opt ; 52(15): 3477-83, 2013 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-23736232

RESUMEN

An iterative adaptive weighted filtered backprojection (FBP) approach was applied to our photoacoustic imaging (PAI) of the optical absorption in biological tissues from limited-view data. By using an image-based adaptive weighted PAI reconstruction, we can modify the defect of the artifacts degrading the quality of the image. Results of numerical simulations demonstrated that the proposed algorithm was superior to FBP in terms of both accuracy and robustness to noise. Reconstructed images of biological tissues agreed well with the structures of the samples. The resolution of the PAI system with the proposed method was experimentally demonstrated to be better than 0.14 mm. By using the proposed method, the imaging quality of the PAI system can be improved.


Asunto(s)
Acústica , Hígado/patología , Algoritmos , Animales , Diseño de Equipo , Procesamiento de Imagen Asistido por Computador/métodos , Modelos Teóricos , Óptica y Fotónica , Porcinos
10.
Bioengineering (Basel) ; 10(4)2023 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-37106587

RESUMEN

Cardiovascular disease (CVD) has become a common health problem of mankind, and the prevalence and mortality of CVD are rising on a year-to-year basis. Blood pressure (BP) is an important physiological parameter of the human body and also an important physiological indicator for the prevention and treatment of CVD. Existing intermittent measurement methods do not fully indicate the real BP status of the human body and cannot get rid of the restraining feeling of a cuff. Accordingly, this study proposed a deep learning network based on the ResNet34 framework for continuous prediction of BP using only the promising PPG signal. The high-quality PPG signals were first passed through a multi-scale feature extraction module after a series of pre-processing to expand the perceptive field and enhance the perception ability on features. Subsequently, useful feature information was then extracted by stacking multiple residual modules with channel attention to increase the accuracy of the model. Lastly, in the training stage, the Huber loss function was adopted to stabilize the iterative process and obtain the optimal solution of the model. On a subset of the MIMIC dataset, the errors of both SBP and DBP predicted by the model met the AAMI standards, while the accuracy of DBP reached Grade A of the BHS standard, and the accuracy of SBP almost reached Grade A of the BHS standard. The proposed method verifies the potential and feasibility of PPG signals combined with deep neural networks in the field of continuous BP monitoring. Furthermore, the method is easy to deploy in portable devices, and it is more consistent with the future trend of wearable blood-pressure-monitoring devices (e.g., smartphones and smartwatches).

11.
IEEE Trans Image Process ; 32: 6155-6167, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37938958

RESUMEN

Facial age estimation has received a lot of attention for its diverse application scenarios. Most existing studies treat each sample equally and aim to reduce the average estimation error for the entire dataset, which can be summarized as General Age Estimation. However, due to the long-tailed distribution prevalent in the dataset, treating all samples equally will inevitably bias the model toward the head classes (usually the adult with a majority of samples). Driven by this, some works suggest that each class should be treated equally to improve performance in tail classes (with a minority of samples), which can be summarized as Long-tailed Age Estimation. However, Long-tailed Age Estimation usually faces a performance trade-off, i.e., achieving improvement in tail classes by sacrificing the head classes. In this paper, our goal is to design a unified framework to perform well on both tasks, killing two birds with one stone. To this end, we propose a simple, effective, and flexible training paradigm named GLAE, which is two-fold. First, we propose Feature Rearrangement (FR) and Pixel-level Auxiliary learning (PA) for better feature utilization to improve the overall age estimation performance. Second, we propose Adaptive Routing (AR) for selecting the appropriate classifier to improve performance in the tail classes while maintaining the head classes. Moreover, we introduce a new metric, named Class-wise Mean Absolute Error (CMAE), to equally evaluate the performance of all classes. Our GLAE provides a surprising improvement on Morph II, reaching the lowest MAE and CMAE of 1.14 and 1.27 years, respectively. Compared to the previous best method, MAE dropped by up to 34%, which is an unprecedented improvement, and for the first time, MAE is close to 1 year old. Extensive experiments on other age benchmark datasets, including CACD, MIVIA, and Chalearn LAP 2015, also indicate that GLAE outperforms the state-of-the-art approaches significantly.


Asunto(s)
Benchmarking , Aprendizaje , Humanos , Lactante , Adulto
12.
Zool Res ; 44(6): 1026-1038, 2023 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-37804114

RESUMEN

Quantification of behaviors in macaques provides crucial support for various scientific disciplines, including pharmacology, neuroscience, and ethology. Despite recent advancements in the analysis of macaque behavior, research on multi-label behavior detection in socially housed macaques, including consideration of interactions among them, remains scarce. Given the lack of relevant approaches and datasets, we developed the Behavior-Aware Relation Network (BARN) for multi-label behavior detection of socially housed macaques. Our approach models the relationship of behavioral similarity between macaques, guided by a behavior-aware module and novel behavior classifier, which is suitable for multi-label classification. We also constructed a behavior dataset of rhesus macaques using ordinary RGB cameras mounted outside their cages. The dataset included 65 913 labels for 19 behaviors and 60 367 proposals, including identities and locations of the macaques. Experimental results showed that BARN significantly improved the baseline SlowFast network and outperformed existing relation networks. In conclusion, we successfully achieved multi-label behavior detection of socially housed macaques with both economic efficiency and high accuracy.


Asunto(s)
Conducta Animal , Animales , Macaca mulatta
13.
Microsyst Nanoeng ; 9: 1, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36597511

RESUMEN

Flexible wearable sweat sensors allow continuous, real-time, noninvasive detection of sweat analytes, provide insight into human physiology at the molecular level, and have received significant attention for their promising applications in personalized health monitoring. Electrochemical sensors are the best choice for wearable sweat sensors due to their high performance, low cost, miniaturization, and wide applicability. Recent developments in soft microfluidics, multiplexed biosensing, energy harvesting devices, and materials have advanced the compatibility of wearable electrochemical sweat-sensing platforms. In this review, we summarize the potential of sweat for medical detection and methods for sweat stimulation and collection. This paper provides an overview of the components of wearable sweat sensors and recent developments in materials and power supply technologies and highlights some typical sensing platforms for different types of analytes. Finally, the paper ends with a discussion of the challenges and a view of the prospective development of this exciting field.

14.
Cell Rep ; 42(6): 112593, 2023 06 27.
Artículo en Inglés | MEDLINE | ID: mdl-37261950

RESUMEN

The primate frontal lobe (FL) is sensitive to aging-related neurocognitive decline. However, the aging-associated molecular mechanisms remain unclear. Here, using physiologically aged non-human primates (NHPs), we depicted a comprehensive landscape of FL aging with multidimensional profiling encompassing bulk and single-nucleus transcriptomes, quantitative proteome, and DNA methylome. Conjoint analysis across these molecular and neuropathological layers underscores nuclear lamina and heterochromatin erosion, resurrection of endogenous retroviruses (ERVs), activated pro-inflammatory cyclic GMP-AMP synthase (cGAS) signaling, and cellular senescence in post-mitotic neurons of aged NHP and human FL. Using human embryonic stem-cell-derived neurons recapitulating cellular aging in vitro, we verified the loss of B-type lamins inducing resurrection of ERVs as an initiating event of the aging-bound cascade in post-mitotic neurons. Of significance, these aging-related cellular and molecular changes can be alleviated by abacavir, a nucleoside reverse transcriptase inhibitor, either through direct treatment of senescent human neurons in vitro or oral administration to aged mice.


Asunto(s)
Retrovirus Endógenos , Animales , Ratones , Lámina Nuclear , Envejecimiento/fisiología , Senescencia Celular/genética , Neuronas , Primates
15.
J Biomed Biotechnol ; 2012: 741416, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23251081

RESUMEN

Since the 1960s, the stem cells have been extensively studied including embryonic stem cells, neural stem cells, bone marrow hematopoietic stem cells, and mesenchymal stem cells. In the recent years, several stem cells have been initially used in the treatment of diseases, such as in bone marrow transplant. At the same time, isolation and culture experimental technologies for stem cell research have been widely developed in recent years. In addition, molecular imaging technologies including optical molecular imaging, positron emission tomography, single-photon emission computed tomography, and computed tomography have been developed rapidly in recent the 10 years and have also been used in the research on disease mechanism and evaluation of treatment of disease related with stem cells. This paper will focus on recent typical isolation, culture, and observation techniques of stem cells followed by a concise introduction. Finally, the current challenges and the future applications of the new technologies in stem cells are given according to the understanding of the authors, and the paper is then concluded.


Asunto(s)
Técnicas Citológicas/métodos , Investigación con Células Madre , Animales , Técnicas de Cultivo de Célula , Separación Celular , Humanos , Imagen Molecular , Trasplante de Células Madre
16.
Appl Opt ; 51(23): 5676-85, 2012 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-22885581

RESUMEN

Bioluminescence tomography (BLT) can three-dimensionally and quantitatively resolve the molecular processes in small animals in vivo. In this paper, we propose a BLT reconstruction algorithm based on duality and variable splitting. By using duality and variable splitting to obtain a new equivalent constrained optimization problem and updating the primal variable as the Lagrangian multiplier in the dual augmented Lagrangian problem, the proposed method can obtain fast and stable source reconstruction even without the permissible source region and multispectral measurements. Numerical simulations on a mouse atlas and in vivo mouse experiments were conducted to validate the effectiveness and potential of the method.


Asunto(s)
Simulación por Computador , Procesamiento de Imagen Asistido por Computador/métodos , Mediciones Luminiscentes/métodos , Tomografía Óptica/métodos , Algoritmos , Animales , Ratones , Modelos Teóricos , Especificidad de Órganos
17.
Biomed Res Int ; 2022: 8094351, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36217389

RESUMEN

Objective: To review the progress of research on photoplethysmography- (PPG-) based cuffless continuous blood pressure monitoring technologies and prospect the challenges that need to be addressed in the future. Methods: Using Web of Science and PubMed as search engines, the literature on cuffless continuous blood pressure studies using PPG signals in the recent five years were searched. Results: Based on the retrieved literature, this paper describes the available open datasets, commonly used signal preprocessing methods, and model evaluation criteria. Early researches employed multisite PPG signals to calculate pulse wave velocity or time and predicted blood pressure by a simple linear equation. Later, extensive researches were dedicated to mine the features of PPG signals related to blood pressure and regressed blood pressure by machine learning models. Most recently, many researches have emerged to experiment with complex deep learning models for blood pressure prediction with the raw PPG signal as input. Conclusion: This paper summarized the methods in the retrieved literature, provided insight into the artificial intelligence algorithms employed in the literature, and concluded with a discussion of the challenges and opportunities for the development of cuffless continuous blood pressure monitoring technologies.


Asunto(s)
Inteligencia Artificial , Análisis de la Onda del Pulso , Presión Sanguínea , Determinación de la Presión Sanguínea/métodos , Fotopletismografía/métodos , Tecnología
18.
Comput Methods Programs Biomed ; 216: 106651, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35104686

RESUMEN

BACKGROUND AND OBJECTIVE: Craniopharyngioma is a kind of benign brain tumor in histography. However, it might be clinically aggressive and have severe manifestations, such as increased intracranial pressure, hypothalamic-pituitary dysfunction, and visual impairment. It is considered challenging for radiologists to predict the invasiveness of craniopharyngioma through MRI images. Therefore, developing a non-invasive method that can predict the invasiveness and boundary of CP as a reference before surgery is of clinical value for making more appropriate and individualized treatment decisions and reducing the occurrence of inappropriate surgical plan choices. METHODS: The MT-Brain system has consisted of two pathways, a sub-path based on 2D CNN for capturing the features from each slice of MRI images, and a 3D sub-network for capturing additional context information between slices. By introducing the two-path architecture, our system can make full use of the fusion of the above 2D and 3D features for classification. Furthermore, position encoding and mask-guided attention also have been introduced to improve the segmentation and diagnosis performance. To verify the performance of the MT-Brain system, we have enrolled 1032 patients with craniopharyngioma (302 invasion and 730 non-invasion patients), segmented the tumors on postcontrast coronal T1WI and randomized them into a training dataset and a testing dataset at a ratio of 8:2. RESULTS: The MT-Brain system achieved a remarkable performance in diagnosing the invasiveness of craniopharyngioma with the AUC of 83.84%, the accuracy of 77.94%, the sensitivity of 70.97%, and the specificity of 80.99%. In the lesion segmentation task, the predicted boundaries of lesions were similar to those labeled by radiologists with the dice of 66.36%. In addition, some explorations also have been made on the interpretability of deep learning models, illustrating the reliability of the model. CONCLUSIONS: To the best of our knowledge, this study is the first to develop an integrated deep learning model to predict the invasiveness of craniopharyngioma preoperatively and locate the lesion boundary synchronously on MRI. The excellent performances indicate that the MT-Brain system has great potential in real-world clinical applications.


Asunto(s)
Craneofaringioma , Aprendizaje Profundo , Neoplasias Hipofisarias , Craneofaringioma/diagnóstico por imagen , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Neoplasias Hipofisarias/diagnóstico por imagen , Reproducibilidad de los Resultados
19.
RSC Adv ; 12(43): 28254-28263, 2022 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-36320226

RESUMEN

Controlled fabrication of anisotropic materials has become a hotspot in materials science, particularly biomaterials, since the next generation of tissue engineering is based on the application of heterogeneous structures that can simulate the original biological complexity of the body. The current fabrication method of producing anisotropic materials involves expensive and highly specialized equipment, and not every conventional method can be applied to preparing anisotropic materials for corresponding tissue engineering. Anisotropic materials can be easily applied to a problem in tissue engineering: cartilage injury repairing. The articular cartilage consists of four spatially distinct regions: superficial, transitional, deep, and calcified. Each region has a specific extracellular matrix composition, mechanical properties, and cellular organization; this calls for the application of an anisotropic hydrogel. Controlled diffusion, under the assistance of buoyancy, has been considered a generalized method to prepare materials using a gradient. The diffusion of two solutions can be controlled through the difference in their densities. In addition to providing anisotropy, this method realizes the in situ formation of an anisotropic hydrogel, and simplifies the preparation process, freeing it from the need for expensive equipment such as 3D printing and microfluidics. Herein, an anisotropic hydrogel based on a decellularized extracellular matrix is fabricated and characterized. The as-prepared scaffold possessed specific chemical composition, physical properties, and physiological factor gradient. In vitro experiments ensured its biocompatibility and biological effectiveness; further in vivo experiments confirmed its application in the effective regeneration of cartilage injury.

20.
Phys Med Biol ; 67(10)2022 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-35276686

RESUMEN

Objective.Fluorescence molecular tomography (FMT) is a promising non-invasive optical molecular imaging technology with strong specificity and sensitivity that has great potential for preclinical and clinical studies in tumor diagnosis, drug development and therapeutic evaluation. However, the strong scattering of photons and insufficient surface measurements make it very challenging to improve the quality of FMT image reconstruction and its practical application for early tumor detection. Therefore, continuous efforts have been made to explore more effective approaches or solutions in the pursuit of high-quality FMT reconstructions.Approach.This review takes a comprehensive overview of advances in imaging methodology for FMT, mainly focusing on two critical issues in FMT reconstructions: improving the accuracy of solving the forward physical model and mitigating the ill-posed nature of the inverse problem from a methodological point of view. More importantly, numerous impressive and practical strategies and methods for improving the quality of FMT reconstruction are summarized. Notably, deep learning methods are discussed in detail to illustrate their advantages in promoting the imaging performance of FMT thanks to large datasets, the emergence of optimized algorithms and the application of innovative networks.Main results.The results demonstrate that the imaging quality of FMT can be effectively promoted by improving the accuracy of optical parameter modeling, combined with prior knowledge, and reducing dimensionality. In addition, the traditional regularization-based methods and deep neural network-based methods, especially end-to-end deep networks, can enormously alleviate the ill-posedness of the inverse problem and improve the quality of FMT image reconstruction.Significance.This review aims to illustrate a variety of effective and practical methods for the reconstruction of FMT images that may benefit future research. Furthermore, it may provide some valuable research ideas and directions for FMT in the future, and could promote, to a certain extent, the development of FMT and other methods of optical tomography.


Asunto(s)
Procesamiento de Imagen Asistido por Computador , Tomografía Óptica , Algoritmos , Fluorescencia , Procesamiento de Imagen Asistido por Computador/métodos , Imagen Molecular/métodos , Redes Neurales de la Computación , Fantasmas de Imagen , Tomografía/métodos , Tomografía Computarizada por Rayos X
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