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1.
Biofouling ; 40(7): 431-445, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38973173

RESUMEN

Candida albicans is often implicated in nosocomial infections with fatal consequences. Its virulence is contributed to hydrolytic enzymes and biofilm formation. Previous research focused on studying these virulence factors individually. Therefore, this study aimed to investigate the impact of biofilm formation on the hydrolytic activity using an adapted low-cost method. Eleven strains of C. albicans were used. The biofilms were formed on pre-treated silicone discs using 24-well plates and then deposited on the appropriate agar to test each enzyme, while the planktonic cells were conventionally seeded. Biofilms were analysed using Raman spectroscopy, fluorescent and scanning electron microscopy. The adapted method provided an evaluation of hydrolytic enzymes activity in C. albicans biofilm and showed that sessile cells had a higher phospholipase and proteinase activities compared with planktonic cells. These findings were supported by spectroscopic and microscopic analyses, which provided valuable insights into the virulence mechanisms of C. albicans during biofilm formation.


Asunto(s)
Biopelículas , Candida albicans , Plancton , Candida albicans/fisiología , Biopelículas/crecimiento & desarrollo , Hidrólisis , Microscopía Electrónica de Rastreo , Fosfolipasas/metabolismo , Espectrometría Raman/métodos , Péptido Hidrolasas/metabolismo
2.
J Mycol Med ; 34(3): 101493, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38945044

RESUMEN

BACKGROUND & AIM: Pathogenic fungi are a major threat to public health, and fungal infections are becoming increasingly common and treatment resistant. Chitin, a component of the fungal cell wall, modifies host immunity and contributes to antifungal resistance. Moreover, chitin content is regulated by chitin synthases and chitinases. However, the specific roles and mechanisms remain unclear. In this study, we developed a cytometric imaging assay to quantify chitin content and identify the distribution of chitin in the yeast cell wall. METHODS: The Candida albicans SC5314 and Nakaseomyces glabratus (ex. C. glabrata) ATCC2001 reference strains, as well as 106 clinical isolates, were used. Chitin content, distribution, and morphological parameters were analysed in 12 yeast species. Moreover, machine learning statistical software was used to evaluate the ability of the cytometric imaging assay to predict yeast species using the values obtained for these parameters. RESULTS: Our imaging-cytometry assay was repeatable, reproducible, and sensitive to variations in chitin content in C. albicans mutants or after antifungal stimulation. The evaluated parameters classified the yeast species into the correct clade with an accuracy of 85 %. CONCLUSION: Our findings demonstrate that this easy-to-use assay is an effective tool for the exploration of chitin content in yeast species.

3.
Int J Mol Sci ; 25(12)2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38928103

RESUMEN

The maturation of HIV-1 virions is a crucial process in viral replication. Although T-cells are a primary source of virus production, much of our understanding of virion maturation comes from studies using the HEK293T human embryonic kidney cell line. Notably, there is a lack of comparative analyses between T-cells and HEK293T cells in terms of virion maturation efficiency in existing literature. We previously developed an advanced virion visualization system based on the FRET principle, enabling the effective distinction between immature and mature virions via fluorescence microscopy. In this study, we utilized pseudotyped, single-round infectious viruses tagged with FRET labels (HIV-1 Gag-iFRET∆Env) derived from Jurkat (a human T-lymphocyte cell line) and HEK293T cells to evaluate their virion maturation rates. HEK293T-derived virions demonstrated a maturity rate of 81.79%, consistent with other studies and our previous findings. However, virions originating from Jurkat cells demonstrated a significantly reduced maturation rate of 68.67% (p < 0.0001). Correspondingly, viruses produced from Jurkat cells exhibited significantly reduced infectivity compared to those derived from HEK293T cells, with the relative infectivity measured at 65.3%. This finding is consistent with the observed relative maturation rate of viruses produced by Jurkat cells. These findings suggest that initiation of virion maturation directly correlates with viral infectivity. Our observation highlights the dynamic nature of virus-host interactions and their implications for virion production and infectivity.


Asunto(s)
Transferencia Resonante de Energía de Fluorescencia , VIH-1 , Virión , Humanos , VIH-1/fisiología , VIH-1/patogenicidad , Células HEK293 , Virión/metabolismo , Células Jurkat , Transferencia Resonante de Energía de Fluorescencia/métodos , Replicación Viral , Ensamble de Virus , Infecciones por VIH/virología
4.
Ann Med Surg (Lond) ; 86(4): 2032-2048, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38576920

RESUMEN

This review delves into the strategies for early detection and characterization of Naegleria fowleri infections leading to primary amoebic meningoencephalitis (PAM). The study provides an in-depth analysis of current diagnostic approaches, including cerebrospinal fluid analysis, brain tissue examination, immunostaining techniques, and culture methods, elucidating their strengths and limitations. It explores the geographical distribution of N. fowleri, with a focus on regions near the equator, and environmental factors contributing to its prevalence. The review emphasizes the crucial role of early detection in PAM management, discussing the benefits of timely identification in treatment, personalized care, and prevention strategies. Genomic profiling techniques, such as conventional PCR, nested PCR, multiplex PCR, and real-time PCR, are thoroughly examined as essential tools for accurate and prompt diagnosis. Additionally, the study explores advanced microscopic imaging techniques to characterize N. fowleri's morphology and behavior at different infection stages, enhancing our understanding of its life cycle and pathogenic mechanisms. In conclusion, this review underscores the potential of these strategies to improve our ability to detect, understand, and combat N. fowleri infections, ultimately leading to better patient outcomes and enhanced public health protection.

5.
J Biophotonics ; 17(6): e202300513, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38531615

RESUMEN

Cystic echinococcosis (CE) is a global health concern caused by cestodes, posing diagnostic challenges due to nonspecific symptoms and inconclusive radiographic results. Diagnosis relies on histopathological evaluation of affected tissue, demanding comprehensive tools. In this retrospective case study, Fourier transform infrared microscopy was explored for detecting and identifying CE through biochemical changes in human tissue sections. Tissue samples from 11 confirmed CE patients were analyzed. Archived FFPE blocks were cut and stained, and then CE-positive unstained sections were examined using Fourier transform infrared microscopy post-deparaffinization. Results revealed the method's ability to distinguish echinococcus elements from human tissue, irrespective of organ type. This research showcases the potential of mid-infrared microscopy as a valuable diagnostic tool for CE, offering promise in enhancing diagnostic precision in the face of the disease's complexities.


Asunto(s)
Equinococosis , Humanos , Equinococosis/diagnóstico por imagen , Equinococosis/patología , Espectroscopía Infrarroja por Transformada de Fourier , Microscopía , Estudios Retrospectivos , Femenino
6.
Comput Med Imaging Graph ; 114: 102367, 2024 06.
Artículo en Inglés | MEDLINE | ID: mdl-38522221

RESUMEN

Whole Slide Imaging and Hyperspectral Microscopic Imaging provide great quality data with high spatial and spectral resolution for histopathology. Existing Hyperspectral Whole Slide Imaging systems combine the advantages of the techniques above, thus providing rich information for pathological diagnosis. However, it cannot avoid the problems of slow acquisition speed and mass data storage demand. Inspired by the spectral reconstruction task in computer vision and remote sensing, the Swin-Spectral Transformer U-Net (SSTU) has been developed to reconstruct Hyperspectral Whole Slide images (HWSis) from multiple Hyperspectral Microscopic images (HMis) of small Field of View and Whole Slide images (WSis). The Swin-Spectral Transformer (SST) module in SSTU takes full advantage of Transformer in extracting global attention. Firstly, Swin Transformer is exploited in space domain, which overcomes the high computation cost in Vision Transformer structures, while it maintains the spatial features extracted from WSis. Furthermore, Spectral Transformer is exploited to collect the long-range spectral features in HMis. Combined with the multi-scale encoder-bottleneck-decoder structure of U-Net, SSTU network is formed by sequential and symmetric residual connections of SSTs, which reconstructs a selected area of HWSi from coarse to fine. Qualitative and quantitative experiments prove the performance of SSTU in HWSi reconstruction task superior to other state-of-the-art spectral reconstruction methods.


Asunto(s)
Procesamiento de Imagen Asistido por Computador
7.
Polymers (Basel) ; 16(3)2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38337292

RESUMEN

Knee orthoses assist patients with impaired gait through the amendment of knee abnormalities, restoration of mobility, alleviation of pain, shielding, and immobilization. The inevitable issues with laborious traditional plaster molding procedures for orthoses can be resolved with 3D printing. However, a number of challenges have limited the adoption of 3D printing, the most significant of which is the proper material selection for orthoses. This is so because the material used to make an orthosis affects its strength, adaptability, longevity, weight, moisture response, etc. This study intends to examine the mechanical, physical, and dimensional characteristics of three-dimensional (3D) printing materials (PLA, ABS, PETG, TPU, and PP). The aim of this investigation is to gain knowledge about these materials' potential for usage as knee orthosis materials. Tensile testing, Olympus microscope imaging, water absorption studies, and coordinate measuring machine-based dimension analysis are used to characterize the various 3D printing materials. Based on the investigation, PLA outperforms all other materials in terms of yield strength (25.98 MPa), tensile strength (30.89 MPa), and shrinkage (0.46%). PP is the least water absorbent (0.15%) and most flexible (407.99%); however, it is the most difficult to fabricate using 3D printing. When producing knee orthoses with 3D printing, PLA can be used for the orthosis frame and other structural elements, PLA or ABS for moving parts like hinges, PP for padding, and TPU or PP for the straps. This study provides useful information for scientists and medical professionals who are intrigued about various polymer materials for 3D printing and their effective utilization to fabricate knee orthoses.

8.
Microsc Res Tech ; 87(5): 999-1008, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38189103

RESUMEN

This study employs scanning electron microscopy (SEM) to delve into the intricate pollen morphology of Cucurbitaceae (Gourd Family) species, unraveling the nuanced details of their structural features. Concurrently, the research investigates the antimicrobial potentials encoded within these pollen grains, shedding light on their possible applications in the realm of natural antimicrobial agents. Cucurbitaceae plants showcases significant antibacterial and antifungal potentials, underscoring its potential as a source for novel antimicrobial compounds. This research endeavors to provide a comprehensive analysis of pollen morphometry in 12 Cucurbitaceous species, with the primary goal of identifying pollen morpho-types to enrich the taxonomic understanding of the Cucurbitaceae. Following the Erdtman protocol, the study involved processing, measuring, and capturing pollen grains using SEM techniques. Qualitative data were analyzed to evaluate the variations in pollen types, size, and exine stratified sculptured layering. The pollen grains exhibit characteristics of being monads, ranging in size from medium to very large, with the prevailing shape being prolate-spheroidal in six species. Notably, the maximum polar axis diameter was recorded for Cucurbita pepo (106.3 µm), while the minimum was observed in Zehneria anomala (32.6 µm). The grains of Cucurbitaceae exhibit diverse surface patterns, including reticulate columellae, reticulate, verrucate-scabrate, verrucate-gemmate, echinate baculate, reticulate-perforate, and micro-reticulate. This SEM investigation illuminates the intricacies of Cucurbitaceae pollen morphology while concurrently highlighting their noteworthy antimicrobial potentials. HIGHLIGHTS: High-resolution imaging reveals complex pollen morphology. Identification of unique antimicrobial structures on Cucurbitaceae pollen (gourd family). Exploring medicinal potential: Antimicrobial properties of cucurbitaceae species.


Asunto(s)
Antiinfecciosos , Cucurbitaceae , Microscopía Electrónica de Rastreo , Electrones , Polen/ultraestructura
9.
J Biol Chem ; 300(1): 105511, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38042491

RESUMEN

Myosin binding protein-C (MyBP-C) is a multidomain protein that regulates muscle contraction. Mutations in MYBPC3, the gene encoding for the cardiac variant (henceforth called cMyBP-C), are amongst the most frequent causes of hypertrophic cardiomyopathy. Most mutations lead to a truncated version of cMyBP-C, which is most likely unstable. However, missense mutations have also been reported, which tend to cluster in the central domains of the cMyBP-C molecule. This suggests that these central domains are more than just a passive spacer between the better characterized N- and C-terminal domains. Here, we investigated the potential impact of four different missense mutations, E542Q, G596R, N755K, and R820Q, which are spread over the domains C3 to C6, on the function of MyBP-C on both the isolated protein level and in cardiomyocytes in vitro. Effect on domain stability, interaction with thin filaments, binding to myosin, and subcellular localization behavior were assessed. Our studies show that these missense mutations result in slightly different phenotypes at the molecular level, which are mutation specific. The expected functional readout of each mutation provides a valid explanation for why cMyBP-C fails to work as a brake in the regulation of muscle contraction, which eventually results in a hypertrophic cardiomyopathy phenotype. We conclude that missense mutations in cMyBP-C must be evaluated in context of their domain localization, their effect on interaction with thin filaments and myosin, and their effect on protein stability to explain how they lead to disease.


Asunto(s)
Cardiomiopatía Hipertrófica , Proteínas Portadoras , Mutación Missense , Humanos , Cardiomiopatía Hipertrófica/genética , Proteínas Portadoras/genética , Dominios Proteicos/genética , Estabilidad Proteica
10.
Eur Arch Otorhinolaryngol ; 281(3): 1175-1183, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37646794

RESUMEN

INTRODUCTION: Real-time visualization of intraoperative electrocochleography (ECochG) potentials via a digital microscope during cochlear implantation can provide direct feedback during electrode insertion. The aim of this prospective, randomized study of 50 patients was to obtain long-term data with a focus on residual hearing preservation and speech understanding. MATERIAL AND METHODS: Cochlear implantations were performed in 50 patients (26 female, 24 male) with residual hearing using a digital microscope. Patients were randomized into two groups. Intraoperative ECochG potentials were either displayed directly in the surgeon's field of view (picture-in-picture display, PiP) or not directly in the field of view (without picture-in-picture display, without PiP). Residual hearing preservation and speech comprehension were recorded within a 1-year follow-up period, compared between groups (PiP versus without PiP) and to a control group of 26 patients implanted without ECochG. RESULTS: Mean insertion time was significantly longer in the picture-in-picture group (p = 0.025). Residual hearing preservation after 6 weeks at 250 Hz was significantly better in the picture-in-picture group (p = 0.017). After one year, 76% of patients showed residual hearing in the picture-in-picture group (62% without picture-in-picture technique, p = n.s.). Use of the picture-in-picture technique resulted in better long-term pure tone residual hearing preservation at 250, 500, and 1000 Hz. Speech intelligibility improved by 46% in the picture-in-picture group (38% without picture-in-picture). DISCUSSION: This study is the first to describe long-term results in a large cohort of cochlear implant patients in whom digital visualization of intraoperative ECochG was used. Our results show that visualization of intraoperative ECochG has a positive effect on residual hearing preservation.


Asunto(s)
Implantación Coclear , Implantes Cocleares , Humanos , Masculino , Femenino , Implantación Coclear/métodos , Cóclea/cirugía , Audiometría de Respuesta Evocada/métodos , Inteligibilidad del Habla
11.
Chembiochem ; 24(22): e202300460, 2023 11 16.
Artículo en Inglés | MEDLINE | ID: mdl-37675822

RESUMEN

In structural DNA nanotechnology, E-tiling DNA nanotubes are evidenced to be homogeneous in diameter and thus have great potential in biomedical applications such as cellular transport and communication, transmembrane ion/molecule channeling, and drug delivery. However, a precise structural description of chiral DNA nanotubes with chiral parameters was lacking, thus greatly hindering their application breadth and depth, until we recently raised and partly solved this problem. In this perspective, we summarize recent progress in defining the chiral indices and handedness of E-tiling DNA nanotubes by microscopic imaging, especially atomic force microscopy (AFM) imaging. Such a detailed understanding of the chiral structures of E-tiling DNA nanotubes will be very helpful in the future, on the one hand for engineering DNA nanostructures precisely, and, on the other, for realizing specific physicochemical properties and biological functions successfully.


Asunto(s)
Nanoestructuras , Nanotubos , Lateralidad Funcional , Nanotubos/química , Nanotecnología/métodos , Nanoestructuras/química , ADN/química , Microscopía de Fuerza Atómica/métodos
12.
J Biophotonics ; 16(11): e202300015, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37578837

RESUMEN

The present study presents an alternative analytical workflow that combines mid-infrared (MIR) microscopic imaging and deep learning to diagnose human lymphoma and differentiate between small and large cell lymphoma. We could show that using a deep learning approach to analyze MIR hyperspectral data obtained from benign and malignant lymph node pathology results in high accuracy for correct classification, learning the distinct region of 3900 to 850 cm-1 . The accuracy is above 95% for every pair of malignant lymphoid tissue and still above 90% for the distinction between benign and malignant lymphoid tissue for binary classification. These results demonstrate that a preliminary diagnosis and subtyping of human lymphoma could be streamlined by applying a deep learning approach to analyze MIR spectroscopic data.


Asunto(s)
Aprendizaje Profundo , Linfoma , Humanos , Linfoma/diagnóstico por imagen , Linfoma/patología , Diagnóstico Diferencial , Ganglios Linfáticos , Diagnóstico por Imagen
13.
J Biophotonics ; 16(11): e202300190, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37545092

RESUMEN

The dichroic mirror (DM) is a key component in microscope. We found a ghost in the reflection channel of a dual-channel fluorescence microscope and studied the relationship between the ghost and the incidence angle θ into the DM. The DM emission surface reflection generated ghost if the θ is not 45 ° . We analyzed the distance and intensity relationship between the ghost and the primary image, which is θ -dependent and was demonstrated by imaging live cells and a stage micrometer. The ghost can be eliminated by placing the DM between objective and tube lens, but not between tube lens and detector, ensuring that the incident light into the DM is approximately parallel. Furthermore, the transmitted light of the DM is shifted towards a longer wavelength with increasing θ . Collectively, microscopists must carefully optimize the θ when designing a microscope to avoid the ghost.


Asunto(s)
Microscopía Fluorescente , Microscopía Fluorescente/métodos
14.
Anal Bioanal Chem ; 415(22): 5499-5509, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37382653

RESUMEN

We present a highly integrated point-of-care testing (POCT) device capable of immediately and accurately screening bovine mastitis infection based on somatic cell counting (SCC). The system primarily consists of a homemade cell-counting chamber and a miniature fluorescent microscope. The cell-counting chamber is pre-embedded with acridine orange (AO) in advance, which is simple and practical. And then SCC is directly identified by microscopic imaging analysis to evaluate the bovine mastitis infection. Only 4 µL of raw bovine milk is required for a simple sample testing and accurate SCC. The entire assay process from sampling to result in presentation is completed quickly within 6 min, enabling instant "sample-in and answer-out." Under laboratory conditions, we mixed bovine leukocyte suspension with whole milk and achieved a detection limit as low as 2.12 × 104 cells/mL on the system, which is capable of screening various types of clinical standards of bovine milk. The fitting degrees of the proposed POCT system with manual fluorescence microscopy were generally consistent (R2 > 0.99). As a proof of concept, four fresh milk samples were used in the test. The average accuracy of somatic cell counts was 98.0%, which was able to successfully differentiate diseased cows from healthy ones. The POCT system is user-friendly and low-cost, making it a potential tool for on-site diagnosis of bovine mastitis in resource-limited areas.


Asunto(s)
Mastitis Bovina , Animales , Femenino , Bovinos , Mastitis Bovina/diagnóstico , Leche/metabolismo , Pruebas en el Punto de Atención , Microscopía Fluorescente , Recuento de Células/métodos
15.
Front Bioeng Biotechnol ; 11: 1157852, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37152649

RESUMEN

Hepatic alveolar echinococcosis (HAE) is caused by the metacestode of Echinococcus multilocularis, which shows characteristics of malignant tumors with high mortality. However, traditional diagnostic imaging methods are still not sufficient for the recognition of HAE microlesions in the early stages. Near-infrared-II (900-1700 nm, NIR-II) fluorescence microscopic imaging (NIR-II-FMI) has shown great potential for biomedical detection. A novel type of negative target imaging method based on NIR-II-FMI with the assistance of indocyanine green (ICG) was explored. Then, NIR-II-FMI was applied to the early detection of HAE for the first time. The negative targeting NIR-II fluorescence imaging of HAE-infected mice at different stages with the assistance of ICG under 808 nm of laser irradiation was obtained. Especially, HAE microlesions at the early stage were detected clearly. Moreover, clear intrahepatic angiography was achieved under the same NIR-II-FMI system.

16.
Adv Healthc Mater ; 12(24): e2300541, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37118995

RESUMEN

Thanks to deep penetration and high resolution, the second near-infrared window (NIR-II, 1000-1700 nm) fluorescence (FL) imaging is expected to gain favor in clinical applications, including macroscopic imaging for cancer diagnosis and microangiography for vascular-related disease diagnosis. Nevertheless, most NIR-II fluorescent probes, especially cyanine, are highly susceptible to self-quenching in the aggregated state, which severely limits their application in bioimaging. Here, the Br-modified cyanine dye F4 -Br and the amphiphilic polypeptide poly(oligo[ethylene glycol]methacrylate)-b-poly(benzyl-L-aspartic acid) (POEGMA-PBLA) are synthesized. By modulating the self-assembly of F4 -Br and POEGMA-PBLA to effectively inhibit the H-aggregation of F4 -Br in aqueous solutions, nanoprobe F4 -Br@P17 with outstanding antiquenching capability is developed. This prominent feature allows it to perform vascular microscopic imaging with high spatiotemporal resolution and assess hemodynamic characteristics. F4 -Br@P17 nanoparticles (NPs) with good stability and satisfactory biocompatibility also enable high contrast brightness for NIR-II FL imaging of tumors. Given the efficient enrichment at tumor sites and the promising photothermal conversion efficiency (43.5%), F4 -Br@P17 NPs successfully conduct photothermal therapy and exhibit superior antitumor efficiency under 1064 nm laser irradiation. These remarkable performances reveal the tremendous possibility of F4 -Br@P17 NPs for in vivo microscopic imaging and FL imaging-guided photothermal therapy in the NIR-II region.


Asunto(s)
Nanopartículas , Neoplasias , Humanos , Neoplasias/diagnóstico por imagen , Neoplasias/terapia , Polietilenglicoles , Imagen Óptica , Péptidos , Línea Celular Tumoral , Fototerapia
17.
Adv Drug Deliv Rev ; 197: 114841, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37088402

RESUMEN

Neurodegenerative diseases (NDs) are progressive disorders that cause the degeneration of neurons. Mitochondrial dysfunction is a common symptom in NDs and plays a crucial role in neuronal loss. Mitochondrial abnormalities can be observed in the early stages of NDs and evolve throughout disease progression. Visualizing mitochondrial abnormalities can help understand ND progression and develop new therapeutic strategies. Fluorescence microscopy is a powerful tool for dynamically imaging mitochondria due to its high sensitivity and spatiotemporal resolution. This review discusses the relationship between mitochondrial dysfunction and ND progression, potential biomarkers for imaging dysfunctional mitochondria, advances in fluorescence microscopy for detecting organelles, the performance of fluorescence probes in visualizing ND-associated mitochondria, and the challenges and opportunities for developing new generations of fluorescence imaging platforms for monitoring mitochondria in NDs.


Asunto(s)
Enfermedades Neurodegenerativas , Humanos , Enfermedades Neurodegenerativas/diagnóstico por imagen , Enfermedades Neurodegenerativas/terapia , Mitocondrias , Biomarcadores , Neuronas , Microscopía Fluorescente
18.
Cells ; 12(3)2023 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-36766719

RESUMEN

Identifying infectious pathogens quickly and accurately is significant for patients and doctors. Identifying single bacterial strains is significant in eliminating culture and speeding up diagnosis. We present an advanced optical method for the rapid detection of infectious (including common and uncommon) pathogens by combining hyperspectral microscopic imaging and deep learning. To acquire more information regarding the pathogens, we developed a hyperspectral microscopic imaging system with a wide wavelength range and fine spectral resolution. Furthermore, an end-to-end deep learning network based on feature fusion, called BI-Net, was designed to extract the species-dependent features encoded in cell-level hyperspectral images as the fingerprints for species differentiation. After being trained based on a large-scale dataset that we built to identify common pathogens, BI-Net was used to classify uncommon pathogens via transfer learning. An extensive analysis demonstrated that BI-Net was able to learn species-dependent characteristics, with the classification accuracy and Kappa coefficients being 92% and 0.92, respectively, for both common and uncommon species. Our method outperformed state-of-the-art methods by a large margin and its excellent performance demonstrates its excellent potential in clinical practice.


Asunto(s)
Enfermedades Transmisibles , Aprendizaje Profundo , Humanos , Diferenciación Celular , Imágenes Hiperespectrales
19.
Materials (Basel) ; 16(3)2023 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-36770220

RESUMEN

In this study, two different types of amorphous carbonaceous Precambrian rock, classified as noble elite shungite and black raw shungite, were tested as possible electrode materials of natural origin. Both types were machined into cylindrical shapes to form the corresponding solid electrodes and their physicochemical and electrochemical properties were compared with the standard glassy carbon electrode (GCE). The raw stones were first subjected to microscopic imaging by using scanning electron microscopy and energy-dispersive X-ray spectroscopy, both of which indicated significant differences in their morphology and in the content of impurities. An electrode prototype manufactured from noble elite shungite (EShE) with a carbon content of about 94% (w/w) has offered a very satisfactory electrochemical performance with a nearly identical heterogeneous electron-transfer rate constant of 7.8 × 10-3 cm s-1 for ferro/ferricyanide redox couple, a slightly narrower potential range (~2.1 V) and a relatively low double-layer capacitance (of ca. 50 µF), resulting in low background currents comparable to those at the GCE. In contrast, the second electrode based on black raw shungite (BShE) with a carbon content of ca. 63% (w/w) exhibited markedly worse electrochemical properties and more than four times higher double-layer capacitance, both of which were probably due to the presence of poorly conductive impurities. The whole study has been completed with three different examples of electroanalytical applications, revealing that the first type, EShE, is a more suitable material for the preparation of electrodes and may represent a cheap alternative to commercially marketed products.

20.
Sensors (Basel) ; 23(2)2023 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-36679780

RESUMEN

Aiming at guiding agricultural producers to harvest crops at an appropriate time and ensuring the pesticide residue does not exceed the maximum limit, the present work proposed a method of detecting pesticide residue rapidly by analyzing near-infrared microscopic images of the leaves of Shanghaiqing (Brassica rapa), a type of Chinese cabbage with computer vision technology. After image pre-processing and feature extraction, the pattern recognition methods of K nearest neighbors (KNN), naïve Bayes, support vector machine (SVM), and back propagation artificial neural network (BP-ANN) were applied to assess whether Shanghaiqing is sprayed with pesticides. The SVM method with linear or RBF kernel provides the highest recognition accuracy of 96.96% for the samples sprayed with trichlorfon at a concentration of 1 g/L. The SVM method with RBF kernel has the highest recognition accuracy of 79.16~84.37% for the samples sprayed with cypermethrin at a concentration of 0.1 g/L. The investigation on the SVM classification models built on the samples sprayed with cypermethrin at different concentrations shows that the accuracy of the models increases with the pesticide concentrations. In addition, the relationship between the concentration of the cypermethrin sprayed and the image features was established by multiple regression to estimate the initial pesticide concentration on the Shanghaiqing leaves. A pesticide degradation equation was established on the basis of the first-order kinetic equation. The time for pesticides concentration to decrease to an acceptable level can be calculated on the basis of the degradation equation and the initial pesticide concentration. The present work provides a feasible way to rapidly detect pesticide residue on Shanghaiqing by means of NIR microscopic image technique. The methodology laid out in this research can be used as a reference for the pesticide detection of other types of vegetables.


Asunto(s)
Residuos de Plaguicidas , Plaguicidas , Residuos de Plaguicidas/análisis , Teorema de Bayes , Verduras/química
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