RESUMO
Smart hydrogels have recently garnered significant attention in the fields of actuators, human-machine interaction, and soft robotics. However, when constructing large-scale actuated systems, they usually exhibit limited actuation forces (≈2 kPa) and actuation speeds. Drawing inspiration from hairspring energy conversion mechanism, an elasticity-plasticity-controllable composite hydrogel (PCTA) with robust contraction capabilities is developed. By precisely manipulating intermolecular and intramolecular hydrogen-bonding interactions, the material's elasticity and plasticity can be programmed to facilitate efficient energy storage and release. The proposed mechanism enables rapid generation of high contraction forces (900 kPa) at ultra-high working densities (0.96 MJ m-3). Molecular dynamics simulations reveal that modifications in the number and nature of hydrogen bonds lead to a distinct elastic-plastic transition in hydrogels. Furthermore, the conductive PCTA hydrogel exhibits multimodal sensing capabilities including stretchable strain sensing with a wide sensing range (1-200%), fast response time (180 ms), and excellent linearity of the output signal. Moreover, it demonstrates exceptional temperature and humidity sensing capabilities with high detection accuracy. The strong actuation power and real-time sensory feedback from the composite hydrogels are expected to inspire novel flexible driving materials and intelligent sensing systems.
RESUMO
OBJECTIVE: The application of transfer learning, specifically pre-training and fine-tuning, in steady-state visual evoked potential (SSVEP)-based brain-computer interfaces (BCIs) has been demonstrated to effectively improve the classification performance of deep learning methods with limited calibration data. However, effectively learning task-related knowledge from source domains during the pre-training phase remains challenging. To address this issue, this study proposes an effective data augmentation method called Reconstruction of Channel Correlation (RCC) to optimize the utilization of the source domain data. METHODS: Concretely, RCC reconstructs training samples using probabilistically mixed eigenvector matrices derived from covariance matrices across source domains. This process manipulates the channel correlation of training samples, implicitly creating novel synthesized domains. By increasing the diversity of source domains, RCC aims to enhance the domain generalizability of the pre-trained model. The effectiveness of RCC is validated through subject-independent and subject-adaptive classification experiments. RESULTS: The results of subject-independent classification demonstrate that RCC significantly improves the classification performance of the pre-trained model on unseen target subjects. Moreover, when compared to the fine-tuning process using the RCC-absent pre-trained model, the fine-tuning process using the RCC-enhanced pre-trained model yields significantly improved performance in the subject-adaptive classification. CONCLUSION: RCC proves to enhance the performance of transfer learning by optimizing the utilization of the source domain data. SIGNIFICANCE: The RCC-enhanced transfer learning has the potential to facilitate the practical implementation of SSVEP-BCIs in real-world scenarios.
RESUMO
Objective.Various artifacts in electroencephalography (EEG) are a big hurdle to prevent brain-computer interfaces from real-life usage. Recently, deep learning-based EEG denoising methods have shown excellent performance. However, existing deep network designs inadequately leverage inter-channel relationships in processing multi-channel EEG signals. Typically, most methods process multi-channel signals in a channel-by-channel way. Considering the correlations among EEG channels during the same brain activity, this paper proposes utilizing channel relationships to enhance denoising performance.Approach.We explicitly model the inter-channel relationships using the self-attention mechanism, hypothesizing that these correlations can support and improve the denoising process. Specifically, we introduce a novel denoising network, named spatial-temporal fusion network (STFNet), which integrates stacked multi-dimension feature extractor to explicitly capture both temporal dependencies and spatial relationships.Main results.The proposed network exhibits superior denoising performance, with a 24.27% reduction in relative root mean squared error compared to other methods on a public benchmark. STFNet proves effective in cross-dataset denoising and downstream classification tasks, improving accuracy by 1.40%, while also offering fast processing on CPU.Significance.The experimental results demonstrate the importance of integrating spatial and temporal characteristics. The computational efficiency of STFNet makes it suitable for real-time applications and a potential tool for deployment in realistic environments.
Assuntos
Artefatos , Eletroencefalografia , Eletroencefalografia/métodos , Humanos , Interfaces Cérebro-Computador , Processamento de Sinais Assistido por Computador , Razão Sinal-Ruído , Aprendizado ProfundoRESUMO
Replicating human somatosensory networks in robots is crucial for dexterous manipulation, ensuring the appropriate grasping force for objects of varying softness and textures. Despite advances in artificial haptic sensing for object recognition, accurately quantifying haptic perceptions to discern softness and texture remains challenging. Here, we report a methodology that uses a bimodal haptic sensor to capture multidimensional static and dynamic stimuli, allowing for the simultaneous quantification of softness and texture features. This method demonstrates synergistic measurements of elastic and frictional coefficients, thereby providing a universal strategy for acquiring the adaptive gripping force necessary for scarless, antislippage interaction with delicate objects. Equipped with this sensor, a robotic manipulator identifies porcine mucosal features with 98.44% accuracy and stably grasps visually indistinguishable mature white strawberries, enabling reliable tissue palpation and intelligent picking. The design concept and comprehensive guidelines presented would provide insights into haptic sensor development, promising benefits for robotics.
Assuntos
Robótica , Animais , Suínos , Humanos , Força da Mão/fisiologia , TatoRESUMO
Cold-induced vasoconstriction is a significant contributor that leads to chilblains and hypothermia in humans. However, current animal models have limitations in replicating cold-induced acral injury due to their low sensitivity to cold. Moreover, existing in vitro vascular chips composed of endothelial cells and perfusion systems lack temperature responsiveness, failing to simulate the vasoconstriction observed under cold stress. This study presents a novel approach where a microfluidic bioreactor of vessel-on-a-chip was developed by grafting the inner microchannel surface of polydimethylsiloxane with a thermosensitive hydrogel skin composed of N-isopropyl acrylamide and gelatin methacrylamide. With a lower critical solution temperature set at 30°C, the gel layer exhibited swelling at low temperatures, reducing the flow rate inside the channel by 10% when the temperature dropped from 37°C to 4°C. This well mimicked the blood stasis observed in capillary vessels in vivo. The vessel-on-a-chip was further constructed by culturing endothelial cells on the surface of the thermosensitive hydrogel layer, and a perfused medium was introduced to the cells to provide a physiological shear stress. Notably, cold stimulation of the vessel-on-a-chip led to cell necrosis, mitochondrial membrane potential (ΔΨm) collapse, cytoskeleton disaggregation, and increased levels of reactive oxygen species. In contrast, the static culture of endothelial cells showed limited response to cold exposure. By faithfully replicating cold-induced endothelial injury, this groundbreaking thermosensitive vessel-on-a-chip technology offers promising advancements in the study of cold-induced cardiovascular diseases, including pathogenesis and therapeutic drug screening.
RESUMO
In addition to the common blood and urine, fresh sweat contains a diverse range of physiological indicators that can effectively reflect changes in the body's state. Wearable sweat sensors are crucial for understanding human physiological health; however, real-time in situ measurement of multiple biomarkers in sweat remains a significant challenge. Here, we propose a wearable microfluidic patch featuring an integrated microfluidic channel and evaporation pump for accelerated and continuous sweat collection, eliminating the need for additional sweat storage cavities that typically impede real-time detection. Capillary forces are harnessed to facilitate the rapid flow of sweat through the detection area, while an evaporation pump based on porous laser-induced graphene enhances sweat evaporation. The synergistic integration of these two components enables an uninterrupted flow of fresh sweat within the patch, ensuring real-time monitoring. The influence of channel size parameters on sweat flow velocity is analyzed, and the optimal width-to-height ratio for achieving the desired flow velocity is determined. By implementing a multi-channel parallel design with chamfering, liquid flow resistance is effectively reduced. Furthermore, the patch integrates sensor modules for sodium ion, chloride ion, glucose, and pH value measurements, ensuring excellent sealing and stability of the assembled system. This work presents a simplified approach to developing wearable sweat sensors that hold the potential for health monitoring and disease diagnosis.
RESUMO
OBJECTIVE: To identify the factors associated with the care needs of the older adults aged 65-105 by age groups, and to compare these factors across different age groups. METHODS: A total of 12 244 older adults from the Chinese longitudinal healthy longevity survey (CLHLS) conducted in 2018 were included in the analyses. The participants were categorized into three age groups: young-old (aged 65-79), middle-old (aged 80-89), and oldest-old (aged 90-105). The level of disability was measured by the disability index (DI) in four dimensions, reflecting their care needs. Potential factors associated with care needs were selected based on the health ecological model (HEM), including perspectives of personal characteristics, behavioral characteristics, interpersonal network, living and working conditions, and policy environment. Multifactor analysis was performed using multinomial Logistic regression. RESULTS: Among China ' s 12 244 older adults, 43.4% had medium or high care needs. Factors for higher care needs of older adults included higher age, higher number of chronic diseases, no exercise habit, excessive sleep duration (≥9 h/d), depressive tendency, living with children or spouse, and uneducated (all P < 0.05). In addition, the young-old group who were past smokers (OR=2.009, 95% CI: 1.019-3.959), were past drinkers (OR=2.213, 95% CI: 1.141-4.291), and reported self-perceived poverty (OR=2.051, 95% CI: 1.189-3.540), had higher level of care needs. The middle-old group who were female (OR=1.373, 95% CI: 1.038-1.817), never drank alcohol (OR=1.551, 95% CI: 1.059-2.269), and were lack of medical insurance (OR=1.598, 95% CI: 1.053-2.426), and had higher level of care needs. The oldest-old group who were female (medium care needs vs. low care needs: OR=1.412, 95% CI: 1.062-1.878; high care needs vs. low care needs: OR=1.506, 95% CI: 1.137-1.993), reported self-perceived poverty (OR=2.064, 95% CI: 1.282-3.323), and were lack of medical insurance (OR=1.621, 95% CI: 1.148-2.291), and had higher level of care needs. CONCLUSION: The identical factors associated with care needs across different age groups include age, chronic disease, exercise, sleep, depression, living arrangement, and education. Smoking, alcohol consumption, and economic status are specific factors among the young-old group of the older adults, while gender and medical insurance are specific factors among the middle-old and the oldest-old group of the older adults. We recommend conducting prospective cohort studies and intervention studies among specific age groups on the above factors to provide reliable evidence for policy formulation.
Assuntos
Pessoas com Deficiência , Humanos , Idoso , Feminino , Masculino , Idoso de 80 Anos ou mais , Pessoas com Deficiência/estatística & dados numéricos , China , Fatores Etários , Doença Crônica , Estudos Longitudinais , Necessidades e Demandas de Serviços de Saúde , Depressão/epidemiologiaRESUMO
A microfluidic sweat monitoring patch that collects human sweat for a long time is designed to achieve the effect of detecting the rise and fall of human sweat glucose over a long period of time by increasing the use time of a single patch. Five collection pools, four serpentine channels, and two different valves are provided. Among them, the three-dimensional valve has a large burst pressure as a balance between the internal and external air pressures of the patch. The bursting pressure of the two-dimensional diverter valve is smaller than that of the three-dimensional gas valve, and its role is to control the flow direction of the liquid. Through plasma hydrophilic treatment of different durations, the optimal hydrophilic duration is obtained. The embedded chromogenic disc detects the sweat glucose value at two adjacent time intervals and compares the information of the human body to increase or reduce glucose. The patch has good flexibility and can fit well with human skin, and because polydimethylsiloxane (PDMS) has good light transmission, it reduces the measurement error caused by the color-taking process and makes the detection results more accurate.
Assuntos
Suor , Humanos , Suor/química , Hipoglicemia , Glucose/análise , Técnicas Biossensoriais , Microfluídica , Dimetilpolisiloxanos/química , Glicemia/análiseRESUMO
Sweat analysis is identified as a promising biochemical technique for the non-invasive assessment of human health status. Epidermal microfluidic patches are the predominant sweat sampling and sensing devices. However, the sweat stored inside the patches may suffer from evaporation loss of moisture, which can increase the concentration of biomarkers and cause the biochemical analysis results of sweat to deviate from the actual results. This study focuses on quantitatively analysing the sweat evaporation loss within epidermal microfluidic patches. Analytical models based on the dissolution diffusion mechanism and corresponding partial differential equations for the diffusion process were initially developed. The analytical solution of the equation was derived using the method of separation of variables, and the steady-state concentration distribution of water in the materials of microfluidic patches was calculated when considering the application of epidermal microfluidics. Evaporation losses of sweat through different paths were quantitatively calculated and analysed, including permeation through covers, diffusion along microchannels, and absorption by sidewalls. Then, experiments on the evaporation loss of sweat within microfluidic patches were conducted to validate the theoretical calculations and analytical results. At last, the design of the anti-evaporation structure for microfluidic patches was discussed. This study can provide theoretical and experimental references for the design of water-retention structures in epidermal microfluidic patches, which significantly enhances the overall reliability of sweat biochemical analysis results.
RESUMO
Porcine models are frequently used for burn healing studies; however, factors including anatomic location and lack of standardised wound methods can impact the interpretation of wound data. The objectives of this study are to examine the influence of anatomical locations on the uniformity of burn creation and healing in porcine burn models. To optimise burn parameters on dorsal and ventral surfaces, ex vivo and in situ euthanized animals were first used to examine the location-dependence of the burn depth and contact time relationship. The location-dependent healing in vivo was then examined using burn and excisional wounds at dorsal, ventral, caudal and cranial locations. Lactate dehydrogenase (LDH) and H&E were used to assess burn depth and wound re-epithelialization. We found that burn depth on the ventral skin was significantly deeper than that of the dorsal skin at identical thermal conditions. Compared with burns created ex vivo, burns created in situ immediately post-mortem were significantly deeper in the ventral location. In live animals, 2 out of 12 burn wounds were fully re-epithelialized after 14 days in contrast to complete re-epithelialization of all excisional wounds. Among the burn wounds, those at the cranial-dorsal site exhibited faster healing than at the caudal-dorsal site. This study showed that anatomical location is an important consideration for the consistency of burn depth creation and healing. These data support symmetric localization of treatment and control for comparative assessment of burn healing in porcine models to prevent misinterpretation of results and increase the translatability of findings to humans.
RESUMO
The skin and its microbiome function to protect the host from pathogen colonization and environmental stressors. In this study, using the Wisconsin Miniature Swine™ model, we characterize the porcine skin fungal and bacterial microbiomes, identify bacterial isolates displaying antifungal activity, and use whole-genome sequencing to identify biosynthetic gene clusters encoding for secondary metabolites that may be responsible for the antagonistic effects on fungi. Through this comprehensive approach of paired microbiome sequencing with culturomics, we report the discovery of novel species of Corynebacterium and Rothia. Further, this study represents the first comprehensive evaluation of the porcine skin mycobiome and the evaluation of bacterial-fungal interactions on this surface. Several diverse bacterial isolates exhibit potent antifungal properties against opportunistic fungal pathogens in vitro. Genomic analysis of inhibitory species revealed a diverse repertoire of uncharacterized biosynthetic gene clusters suggesting a reservoir of novel chemical and biological diversity. Collectively, the porcine skin microbiome represents a potential unique source of novel antifungals.
Assuntos
Fungos , Microbiota , Pele , Animais , Pele/microbiologia , Suínos/microbiologia , Microbiota/genética , Fungos/genética , Fungos/efeitos dos fármacos , Antifúngicos/farmacologia , Antibiose , Micobioma/genética , Bactérias/genética , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Bactérias/metabolismo , Corynebacterium/genética , Corynebacterium/efeitos dos fármacos , Porco Miniatura/microbiologia , Família Multigênica , Sequenciamento Completo do Genoma , Metabolismo Secundário/genéticaRESUMO
Solid-state polymer-based electrolytes (SSPEs) exhibit great possibilities in realizing high-energy-density solid-state lithium metal batteries (SSLMBs). However, current SSPEs suffer from low ionic conductivity and unsatisfactory interfacial compatibility with metallic Li because of the high crystallinity of polymers and sluggish Li+ movement in SSPEs. Herein, differing from common strategies of copolymerization, a new strategy of constructing a high-entropy SSPE from multivariant polymeric ligands is proposed. As a protocol, poly(vinylidene fluoride-co-hexafluoropropylene) (PH) chains are grafted to the demoed polyethylene imine (PEI) with abundant -NH2 groups via a click-like reaction (HE-PEIgPHE). Compared to a PH-based SSPE, our HE-PEIgPHE shows a higher modulus (6.75 vs 5.18 MPa), a higher ionic conductivity (2.14 × 10-4 vs 1.03 × 10-4 S cm-1), and a higher Li+ transference number (0.55 vs 0.42). A Li|HE-PEIgPHE|Li cell exhibits a long lifetime (1500 h), and a Li|HE-PEIgPHE|LiFePO4 cell delivers an initial capacity of 160 mAh g-1 and a capacity retention of 98.7%, demonstrating the potential of our HE-PEIgPHE for the SSLMBs.
RESUMO
This study presents two cases of type II mixed cryoglobulinemia. One case is essential, while the other is presumably associated with hepatitis B virus (HBV) infection. Both patients tested positive for monoclonal IgMκ, but negative for MyD88 mutation. They showed resistance to rituximab combined with a glucosteroid regimen, but responded positively to BTK inhibitors. These cases highlight the remarkable effectiveness of BTK inhibitors in treating refractory type II cryoglobulinemia without MyD88 mutation. The first patient achieved rapid complete remission of nephrotic syndrome within one month of starting ibrutinib, along with a significant reduction in cryoglobulin levels and abnormal clonal cells. The second patient had a rapid disappearance of rash within three days and accelerated wound healing within one week of initiating orelabrutinib, accompanied by a reduction in C-reactive protein. However, there was no reduction in cryoglobulin levels during the 12-month follow-up. These findings suggest varied mechanisms of action of BTK inhibitors in type II cryoglobulinemia through different mechanisms.
Assuntos
Tirosina Quinase da Agamaglobulinemia , Crioglobulinemia , Fator 88 de Diferenciação Mieloide , Inibidores de Proteínas Quinases , Humanos , Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Crioglobulinemia/tratamento farmacológico , Crioglobulinemia/etiologia , Fator 88 de Diferenciação Mieloide/genética , Inibidores de Proteínas Quinases/uso terapêutico , Pessoa de Meia-Idade , Masculino , Feminino , Adenina/análogos & derivados , Adenina/uso terapêutico , Idoso , Piperidinas/uso terapêutico , Resultado do TratamentoRESUMO
PURPOSE OF REVIEW: Human brain parcellation based on functional magnetic resonance imaging (fMRI) plays an essential role in neuroscience research. By segmenting vast and intricate fMRI data into functionally similar units, researchers can better decipher the brain's structure in both healthy and diseased states. This article reviews current methodologies and ideas in this field, while also outlining the obstacles and directions for future research. RECENT FINDINGS: Traditional brain parcellation techniques, which often rely on cytoarchitectonic criteria, overlook the functional and temporal information accessible through fMRI. The adoption of machine learning techniques, notably deep learning, offers the potential to harness both spatial and temporal information for more nuanced brain segmentation. However, the search for a one-size-fits-all solution to brain segmentation is impractical, with the choice between group-level or individual-level models and the intended downstream analysis influencing the optimal parcellation strategy. Additionally, evaluating these models is complicated by our incomplete understanding of brain function and the absence of a definitive "ground truth". SUMMARY: While recent methodological advancements have significantly enhanced our grasp of the brain's spatial and temporal dynamics, challenges persist in advancing fMRI-based spatio-temporal representations. Future efforts will likely focus on refining model evaluation and selection as well as developing methods that offer clear interpretability for clinical usage, thereby facilitating further breakthroughs in our comprehension of the brain.
Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Humanos , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Mapeamento Encefálico/métodos , Processamento de Imagem Assistida por Computador/métodosRESUMO
BACKGROUND: Delayed indocyanine green fluorescence imaging is under investigation in various clinical disease processes. Understanding the mechanisms of indocyanine green accumulation and retention is essential to correctly interpreting and analyzing imaging data. The purpose of this scoping review was to synthesize what is known about the mechanism of indocyanine green retention at the cellular level to better understand the clinical nuances of delayed indocyanine green imaging and identify critical gaps in our knowledge to guide future studies. METHODS: We performed a scoping review of 7,087 citations after performing database searches of PubMed, Scopus, the Cochrane Library, and the Web of Science Core Collection electronic databases. Studies were eligible for inclusion if they were peer-reviewed original research discussing the mechanism of indocyanine green retention in the results section in disease processes involving inflammation and/or necrosis, including cancer, and were available in English. Data were extracted using Covidence software. RESULTS: Eighty-nine studies were included in the final analysis. Several features of indocyanine green retention were identified. CONCLUSION: We identified several mechanistic features involved in indocyanine green accumulation in diseased tissue that overall had distinct mechanisms of indocyanine green retention in tumors, nontumor inflammation, and necrosis. Our study also reveals new insights on how inflammatory infiltrate influences indocyanine green fluorescence imaging. These findings are noteworthy because they add to our understanding of how fluorescence-guided surgery may be optimized based on the pathology of interest via specific indocyanine green dosing and timing of image acquisition.
Assuntos
Verde de Indocianina , Imagem Óptica , Humanos , Imagem Óptica/métodos , Inflamação/diagnóstico por imagem , Corantes , Neoplasias/diagnóstico por imagem , Necrose/diagnóstico por imagemRESUMO
Phthalate acid esters (PAEs) and their metabolites, such as di-n-butyl phthalate (DBP) and mono-n-butyl phthalate (MBP), are known to cause male reproductive damage. Lactiplantibacillus plantarum RS20D has demonstrated the ability to remove both DBP and MBP in vitro, suggesting its potential as a detoxifying agent against these compounds. This study aimed to investigate the protective effects of RS20D on DBP or MBP-induced male reproductive toxicity in adolescent rats. Oral administration of RS20D significantly mitigated the histological damage to the testes caused by MBP or DBP, restored sperm concentration, morphological abnormalities, and the proliferation index in MBP-exposed rats, and partially reversed spermatogenic damage in DBP-exposed rats. Furthermore, RS20D restored serum levels of estradiol (E2) and testosterone, and superoxide dismutase (SOD) activity in DBP-exposed rats, significantly increased testosterone levels in MBP-exposed rats, and restored copper (Cu) concentrations in the testes after exposure to DBP or MBP. Additionally, RS20D effectively modulated the intestinal microbiota in DBP-exposed rats and partially ameliorated dysbiosis induced by MBP, which may be associated with the alleviation of reproductive toxic effects induced by DBP or MBP. In conclusion, this study demonstrates that RS20D administration can alleviate male reproductive toxicity and gut dysbacteriosis induced by DBP or MBP exposure, providing a dietary strategy for the bioremediation of PAEs and their metabolites.
RESUMO
The utilization of xylanase in juice clarification is contingent upon its stability within acidic environments. We generated a mutant xynA-1 by substituting the N-terminal segment of the recombinant xylanase xynA to investigate the correlation between the N-terminal region of xylanase and its acid stability. The enzymatic activity of xynA-1 was found to be superior under acidic conditions (pH 5.0). It exhibited enhanced acid stability, surpassing the residual enzyme activity values of xynA at pH 4.0 (53.07 %), pH 4.5 (69.8 %), and pH 5.0 (82.4 %), with values of 60.16 %, 77.74 %, and 87.3 %, respectively. Additionally, the catalytic efficiency of xynA was concurrently improved. Through molecular dynamics simulation, we observed that N-terminal shortening induced a reduction in motility across most regions of the protein structure while enhancing its stability, particularly Lys131-Phe146 and Leu176-Gly206. Furthermore, the application of treated xynA-1 in the process of apple juice clarification led to a significant increase in clarity within a short duration of 20 min at 35 °C while ensuring the quality of the apple juice. This study not only enhances the understanding of the N-terminal region of xylanase but also establishes a theoretical basis for augmenting xylanase resources employed in fruit juice clarification.
Assuntos
Endo-1,4-beta-Xilanases , Estabilidade Enzimática , Sucos de Frutas e Vegetais , Malus , Proteínas Recombinantes , Endo-1,4-beta-Xilanases/química , Endo-1,4-beta-Xilanases/genética , Endo-1,4-beta-Xilanases/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Concentração de Íons de Hidrogênio , Malus/química , Malus/enzimologia , Simulação de Dinâmica MolecularRESUMO
In the field of medical imaging, the fusion of data from diverse modalities plays a pivotal role in advancing our understanding of pathological conditions. Sparse representation (SR), a robust signal modeling technique, has demonstrated noteworthy success in multi-dimensional (MD) medical image fusion. However, a fundamental limitation appearing in existing SR models is their lack of directionality, restricting their efficacy in extracting anatomical details from different imaging modalities. To tackle this issue, we propose a novel directional SR model, termed complex sparse representation (ComSR), specifically designed for medical image fusion. ComSR independently represents MD signals over directional dictionaries along specific directions, allowing precise analysis of intricate details of MD signals. Besides, current studies in medical image fusion mostly concentrate on addressing either 2D or 3D fusion problems. This work bridges this gap by proposing a MD medical image fusion method based on ComSR, presenting a unified framework for both 2D and 3D fusion tasks. Experimental results across six multi-modal medical image fusion tasks, involving 93 pairs of 2D source images and 20 pairs of 3D source images, substantiate the superiority of our proposed method over 11 state-of-the-art 2D fusion methods and 4 representative 3D fusion methods, in terms of both visual quality and objective evaluation.
Assuntos
Algoritmos , Imageamento Tridimensional , Humanos , Imageamento Tridimensional/métodos , Imagem Multimodal/métodos , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodosRESUMO
Sichuan bacon represents the most prevalent dry-cured meat product across Southwest China, but it is vulnerable to fungal spoilage. In the present study, a total of 47 Sichuan bacons were obtained from different regions of the Sichuan Province and analyzed for the presence of ochratoxin A (OTA), yielding a positive rate of 23.4 % (11/47). All the observed OTA concentrations exceeded the maximum admissible dose in meat products (1 µg/kg) established by some EU countries, with the highest OTA concentration being 250.75 µg/kg, which raises a food safety concern and reveals the need for a standardized scientific processing protocol. Then, an OTA-producing fungus named 21G2-1A was isolated from positive samples and found to be Aspergillus westerdijkiae. Further characterization suggested a positive correlation between fungal growth and OTA production. The optimal temperature for the former was 25 °C, while it was 20 °C for the latter. Although the A. westerdijkiae strain 21G2-1A demonstrated greater mycelium growth in the presence of NaCl, OTA production was significantly dismissed when the salinity was greater than 5 %. Four lactic acid bacteria (LAB) were screened out as antagonists against the ochratoxigenic fungus. In vitro evaluation of the antagonists revealed that live cells inhibited fungal growth, and adsorption also contributed to OTA removal at different levels. This study sheds some light on OTA control in Sichuan bacon through a biological approach.
Assuntos
Ocratoxinas , Carne de Porco , Adsorção , AspergillusRESUMO
As an efficient degradation strain, Sphingobium baderi SC-1 can breakdown 3-phenoxybenzoic acid (3-PBA) with high proficiency. To investigate the internal factors that regulate this process, we conducted whole-genome sequencing and successfully identified the pivotal 3-PBA-degrading gene sca (1,230 bp). After sca was expressed in engineered bacteria, a remarkable degradation efficiency was observed, as 20 mg/L 3-PBA was almost completely decomposed within 24 h. The phenol was formed as one of the degradation products. Notably, in addition to their ability to degrade 3-PBA, the resting cells proficiently degraded 4'-HO-3-PBA and 3'-HO-4-PBA. In conclusion, we successfully identified and validated sca as the pivotal enzyme responsible for the efficient degradation of 3-PBA from Sphingomonas baderi, providing a crucial theoretical foundation for further explorations on the degradation potential of SC-1.