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1.
Anal Chem ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38916969

RESUMO

The integration of electrochemistry with nuclear magnetic resonance (NMR) spectroscopy recently offers a powerful approach to understanding oxidative metabolism, detecting reactive intermediates, and predicting biological activities. This combination is particularly effective as electrochemical methods provide excellent mimics of metabolic processes, while NMR spectroscopy offers precise chemical analysis. NMR is already widely utilized in the quality control of pharmaceuticals, foods, and additives and in metabolomic studies. However, the introduction of additional and external connections into the magnet has posed challenges, leading to signal deterioration and limitations in routine measurements. Herein, we report an anti-interference compact in situ electrochemical NMR system (AICISENS). Through a wireless strategy, the compact design allows for the independent and stable operation of electrochemical NMR components with effective interference isolation. Thus, it opens an avenue toward easy integration into in situ platforms, applicable not only to laboratory settings but also to fieldwork. The operability, reliability, and versatility were validated with a series of biomimetic assessments, including measurements of microbial electrochemical systems, functional foods, and simulated drug metabolisms. The robust performance of AICISENS demonstrates its high potential as a powerful analytical tool across diverse applications.

2.
BMC Med Imaging ; 24(1): 113, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38760778

RESUMO

BACKGROUND: Recent Convolutional Neural Networks (CNNs) perform low-error reconstruction in fast Magnetic Resonance Imaging (MRI). Most of them convolve the image with kernels and successfully explore the local information. Nonetheless, the non-local image information, which is embedded among image patches relatively far from each other, may be lost due to the limitation of the receptive field of the convolution kernel. We aim to incorporate a graph to represent non-local information and improve the reconstructed images by using the Graph Convolutional Enhanced Self-Similarity (GCESS) network. METHODS: First, the image is reconstructed into the graph to extract the non-local self-similarity in the image. Second, GCESS uses spatial convolution and graph convolution to process the information in the image, so that local and non-local information can be effectively utilized. The network strengthens the non-local similarity between similar image patches while reconstructing images, making the reconstruction of structure more reliable. RESULTS: Experimental results on in vivo knee and brain data demonstrate that the proposed method achieves better artifact suppression and detail preservation than state-of-the-art methods, both visually and quantitatively. Under 1D Cartesian sampling with 4 × acceleration (AF = 4), the PSNR of knee data reached 34.19 dB, 1.05 dB higher than that of the compared methods; the SSIM achieved 0.8994, 2% higher than the compared methods. Similar results were obtained for the reconstructed images under other sampling templates as demonstrated in our experiment. CONCLUSIONS: The proposed method successfully constructs a hybrid graph convolution and spatial convolution network to reconstruct images. This method, through its training process, amplifies the non-local self-similarities, significantly benefiting the structural integrity of the reconstructed images. Experiments demonstrate that the proposed method outperforms the state-of-the-art reconstruction method in suppressing artifacts, as well as in preserving image details.


Assuntos
Encéfalo , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Redes Neurais de Computação , Imageamento por Ressonância Magnética/métodos , Humanos , Encéfalo/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Joelho/diagnóstico por imagem , Algoritmos , Artefatos
3.
Molecules ; 29(7)2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38611845

RESUMO

In this paper, berberine hydrochloride-loaded liposomes-in-gel were designed and developed to investigate their antioxidant properties and therapeutic effects on the eczema model of the mouse. Berberine hydrochloride-liposomes (BBH-L) as the nanoparticles were prepared by the thin-film hydration method and then dispersed BBH-L evenly in the gel matrix to prepare the berberine hydrochloride liposomes-gel (BBH-L-Gel) by the natural swelling method. Their antioxidant capacity was investigated by the free radical scavenging ability on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and H2O2 and the inhibition of lipid peroxides malondialdehyde (MDA). An eczema model was established, and the efficacy of the eczema treatment was preliminarily evaluated using ear swelling, the spleen index, and pathological sections as indicators. The results indicate that the entrapment efficiency of BBH-L prepared by the thin-film hydration method was 78.56% ± 0.7%, with a particle size of 155.4 ± 9.3 nm. For BBH-L-Gel, the viscosity and pH were 18.16 ± 6.34 m Pas and 7.32 ± 0.08, respectively. The cumulative release in the unit area of the in vitro transdermal study was 85.01 ± 4.53 µg/cm2. BBH-L-Gel had a good scavenging capacity on DPPH and H2O2, and it could effectively inhibit the production of hepatic lipid peroxides MDA in the concentration range of 0.4-2.0 mg/mL. The topical application of BBH-L-Gel could effectively alleviate eczema symptoms and reduce oxidative stress injury in mice. This study demonstrates that BBH-L-Gel has good skin permeability, excellent sustained release, and antioxidant capabilities. They can effectively alleviate the itching, inflammation, and allergic symptoms caused by eczema, providing a new strategy for clinical applications in eczema treatment.


Assuntos
Berberina , Eczema , Animais , Camundongos , Antioxidantes/farmacologia , Berberina/farmacologia , Lipossomos , Peróxido de Hidrogênio , Peróxidos Lipídicos
4.
BMC Med Imaging ; 23(1): 185, 2023 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-37964218

RESUMO

BACKGROUND: 1H magnetic resonance spectroscopy (1H-MRS) can be used to study neurological disorders because it can be utilized to examine the concentrations of related metabolites. However, the diagnostic utility of different field strengths for temporal lobe epilepsy (TLE) remains unclear. The purpose of this study is to make quantitative comparisons of metabolites of TLE at 1.5T and 3.0T and evaluate their efficacy. METHODS: Our retrospective collections included the single-voxel 1H-MRS of 23 TLE patients and 17 healthy control volunteers (HCs) with a 1.5T scanner, as well as 29 TLE patients and 17 HCs with a 3.0T scanner. Particularly, HCs were involved both the scans with 1.5T and 3.0T scanners, respectively. The metabolites, including the N-acetylaspartate (NAA), creatine (Cr), and choline (Cho), were measured in the left or right temporal pole of brain. To analyze the ratio of brain metabolites, including NAA/Cr, NAA/Cho, NAA/(Cho + Cr) and Cho/Cr, four controlled experiments were designed to evaluate the diagnostic utility of TLE on 1.5T and 3.0T MRS, included: (1) 1.5T TLE group vs. 1.5T HCs by the Mann-Whitney U Test, (2) 3.0T TLE group vs. 3.0T HCs by the Mann-Whitney U Test, (3) the power analysis for the 1.5T and 3.0T scanner, and (4) 3.0T HCs vs. 1.5T HCs by Paired T-Test. RESULTS: Three metabolite ratios (NAA/Cr, NAA/Cho, and NAA/(Cho + Cr) showed the same statistical difference (p < 0.05) in distinguishing the TLE from HCs in the bilateral temporal poles when using 1.5T or 3.0T scanners. Similarly, the power analysis demonstrated that four metabolite ratios (NAA/Cr, NAA/Cho, NAA/(Cho + Cr), Cho/Cr) had similar distinction abilities between 1.5T and 3.0T scanner, denoting both 1.5T and 3.0T scanners were provided with similar sensitivities and reproducibilities for metabolites detection. Moreover, the metabolite ratios of the same healthy volunteers were not statistically different between 1.5T and 3.0T scanners, except for NAA/Cho (p < 0.05). CONCLUSIONS: 1.5T and 3.0T scanners may have comparable diagnostic potential when 1H-MRS was used to diagnose patients with TLE.


Assuntos
Epilepsia do Lobo Temporal , Humanos , Epilepsia do Lobo Temporal/diagnóstico por imagem , Epilepsia do Lobo Temporal/metabolismo , Imageamento por Ressonância Magnética , Estudos Retrospectivos , Espectroscopia de Ressonância Magnética/métodos , Lobo Temporal/metabolismo , Creatina/metabolismo , Colina
5.
BMC Med Imaging ; 21(1): 195, 2021 12 24.
Artigo em Inglês | MEDLINE | ID: mdl-34952572

RESUMO

BACKGROUND: Magnetic resonance imaging (MRI) is an effective auxiliary diagnostic method in clinical medicine, but it has always suffered from the problem of long acquisition time. Compressed sensing and parallel imaging are two common techniques to accelerate MRI reconstruction. Recently, deep learning provides a new direction for MRI, while most of them require a large number of data pairs for training. However, there are many scenarios where fully sampled k-space data cannot be obtained, which will seriously hinder the application of supervised learning. Therefore, deep learning without fully sampled data is indispensable. MAIN TEXT: In this review, we first introduce the forward model of MRI as a classic inverse problem, and briefly discuss the connection of traditional iterative methods to deep learning. Next, we will explain how to train reconstruction network without fully sampled data from the perspective of obtaining prior information. CONCLUSION: Although the reviewed methods are used for MRI reconstruction, they can also be extended to other areas where ground-truth is not available. Furthermore, we may anticipate that the combination of traditional methods and deep learning will produce better reconstruction results.


Assuntos
Aprendizado Profundo , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética , Humanos
6.
Magn Reson Chem ; 59(3): 324-345, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32797694

RESUMO

Nuclear magnetic resonance (NMR) spectroscopy is an important analytical tool in chemistry, biology, and life science, but it suffers from relatively low sensitivity and long acquisition time. Thus, improving the apparent signal-to-noise ratio and accelerating data acquisition became indispensable. In this review, we summarize the recent progress on low-rank Hankel matrix and tensor methods, which exploit the exponential property of free-induction decay signals, to enable effective denoising and spectra reconstruction. We also outline future developments that are likely to make NMR spectroscopy a far more powerful technique.

7.
Molecules ; 26(13)2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34202302

RESUMO

Magnetic resonance spectroscopy (MRS), as a noninvasive method for molecular structure determination and metabolite detection, has grown into a significant tool in clinical applications. However, the relatively low signal-to-noise ratio (SNR) limits its further development. Although the multichannel coil and repeated sampling are commonly used to alleviate this problem, there is still potential room for promotion. One possible improvement way is combining these two acquisition methods so that the complementary of them can be well utilized. In this paper, a novel coil-combination method, average smoothing singular value decomposition, is proposed to further improve the SNR by introducing repeatedly sampled signals into multichannel coil combination. Specifically, the sensitivity matrix of each sampling was pretreated by whitened singular value decomposition (WSVD), then the smoothing was performed along the repeated samplings' dimension. By comparing with three existing popular methods, Brown, WSVD, and generalized least squares, the proposed method showed better performance in one phantom and 20 in vivo spectra.

8.
Chemistry ; 26(46): 10391-10401, 2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32251549

RESUMO

Since the concept of deep learning (DL) was formally proposed in 2006, it has had a major impact on academic research and industry. Nowadays, DL provides an unprecedented way to analyze and process data with demonstrated great results in computer vision, medical imaging, natural language processing, and so forth. Herein, applications of DL in NMR spectroscopy are summarized, and a perspective for DL as an entirely new approach that is likely to transform NMR spectroscopy into a much more efficient and powerful technique in chemistry and life sciences is outlined.


Assuntos
Aprendizado Profundo , Espectroscopia de Ressonância Magnética
9.
BMC Med Imaging ; 20(1): 4, 2020 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-31931731

RESUMO

BACKGROUND: Lung cancer brain metastases are very common and one of the common causes of treatment failure. We aimed to examine the clinical use of chemical exchange saturation transfer (CEST) technology in the evaluation of brain metastases for lung cancer diagnosis and prognosis. METHODS: We included26 cases of lung cancer brain metastases, 15 cases of gliomas, and 20 cases with normal tests. The magnetization transfer ratio (MTR;3.5 ppm) image from the GRE-EPI-CEST sequence was analyzed using the ASSET technique and APT technology. The MTR values were measured in the lesion-parenchymal, edema, and non-focus regions, and the MTR image was compared with the conventional MRI. ANOVA and t-test were used for statistical analysis. RESULTS: The lesion-parenchymal, edema, and non-focus areas in the metastatic-tumor-group were red-yellow, yellow-green, and green-blue, and the MTR values were 3.29 ± 1.14%,1.28 ± 0.36%,and 1.26 ± 0.31%, respectively. However, in the glioma-group, the corresponding areas were red, red-yellow, and green-blue, and the MTR values were 6.29 ± 1.58%, 2.87 ± 0.65%, and 1.03 ± 0.30%, respectively. The MTR values of the corresponding areas in the normal-group were 1.07 ± 0.22%,1.04 ± 0.23%, and 1.06 ± 0.24%, respectively. Traditional MR images are in black-white contrast and no metabolic information is displayed. The MTRvalues of the three regions were significantly different among the three groups. The values were also significantly different between the parenchymal and edema areas in the metastatic-tumor-group. There were significant differences in the MTR values between the non-lesion and edema regions, but there was no significant difference between the edema and non-focus areas. In the glioma-group, there were significant differences in the MTR values between the parenchymal and edema areas, between the parenchymal and non-focus areas, and between the edema and non-focus areas. CONCLUSIONS: CEST reflects the protein metabolism; therefore, early diagnosis of brain metastases and assessment of the prognosis can be achieved using molecular imaging.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/secundário , Glioma/diagnóstico por imagem , Glioma/secundário , Neoplasias Pulmonares/diagnóstico por imagem , Adulto , Idoso , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Interpretação de Imagem Radiográfica Assistida por Computador
10.
J Integr Neurosci ; 19(3): 469-477, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-33070526

RESUMO

We investigated the effects of velvet antler polypeptide on cognitive impairment and the underlying mechanisms. Hydrogen peroxide-induced cell injury was used to establish an in vitro model of SH-SY5Y cells. In addition, we established an in vivo mouse model of cognitive impairment using intraperitoneal injections of scopolamine hydrobromide in strain mice. We administered three different doses of velvet antler polypeptide in this mouse model and assessed the influence of velvet antler polypeptide on the morphology of hippocampal neurons, hippocampal neuronal apoptosis, adrenocorticotropic hormone, and corticosterone activities in brain tissue samples, and the molecular and biochemical regulation of B-cell lymphoma-2, B-cell lymphoma-2 Associated X-protein, Cysteine-aspartic acid protease-3, glucocorticoid receptor, mineralocorticoid receptor, and corticotropin-releasing hormone in murine hippocampal neurons. Our data suggest that velvet antler polypeptide decreases glucocorticoid receptor, mineralocorticoid receptor, and corticotropin-releasing hormone levels and regulates the hormones released by the hypothalamic-pituitary-adrenal axis, thus suppressing neuronal apoptosis.


Assuntos
Chifres de Veado/química , Apoptose/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/administração & dosagem , Peptídeos/administração & dosagem , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Cervos , Feminino , Humanos , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipotálamo-Hipofisário/patologia , Masculino , Camundongos Endogâmicos ICR , Neurônios/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo
11.
Angew Chem Int Ed Engl ; 59(26): 10297-10300, 2020 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-31490596

RESUMO

Nuclear magnetic resonance (NMR) spectroscopy serves as an indispensable tool in chemistry and biology but often suffers from long experimental times. We present a proof-of-concept of the application of deep learning and neural networks for high-quality, reliable, and very fast NMR spectra reconstruction from limited experimental data. We show that the neural network training can be achieved using solely synthetic NMR signals, which lifts the prohibiting demand for a large volume of realistic training data usually required for a deep learning approach.

12.
Mol Biol Rep ; 46(5): 5323-5332, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31364016

RESUMO

Energy metabolism disorders have been shown to exert detrimental effects on the pathology of Alzheimer's disease (AD). The ginsenoside compound K (CK), a major intestinal metabolite underlying the pharmacological actions of orally administered ginseng, has an ameliorating effect against AD, but the relevant molecular mechanism remains unclear. We hypothesized that the improvement of AD by CK is mediated by the energy metabolism signaling pathway induced by amyloid ß peptide (Aß) and tested this hypothesis in HT22 cells. HT22 cells were incubated with CK and exposed to Aß. Cell viability was analyzed using the MTT assay. Cell growth curves were derived from real-time cell analysis. Apoptosis was determined by flow cytometry, Aß localization and expression by immunofluorescence, and ATP content by a specific assay kit. The expression of proteins related to the energy metabolism signaling pathway was analyzed using Western blotting. CK treatment improved cell viability, cell growth, and apoptosis induced by Aß, and the cellular localization and expression of Aß. Moreover, CK increased ATP content by promoting the activity of glucose transporters (GLUTs). Therefore, the neuroprotective effect of CK against Aß injury was mainly realized through the activation of the energy metabolism signaling pathway. CK treatment inhibits neuronal damage caused by Aß through the activation of the energy metabolism signaling pathway, revealing that CK might be one of the key bioactive ingredients of ginseng in the treatment of Alzheimer's disease and may serve as a preventive or therapeutic agent for Alzheimer's disease.


Assuntos
Metabolismo Energético/efeitos dos fármacos , Ginsenosídeos/farmacologia , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , China , Ginsenosídeos/metabolismo , Camundongos , Neurônios/metabolismo , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
13.
Arch Gynecol Obstet ; 299(3): 873-882, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30649603

RESUMO

PURPOSE: It is known that menopausal osteoporosis (MOP) is the most typical form of osteoporosis, which is characterized by low bone mass and microstructure damage of the bone tissue, leading to increased bone fragility and risk of fracture. This study aimed to evaluate the protective effects of Oviductus Ranae protein hydrolyzate (ORPH) on the MOP in vivo. METHODS: Osteoporosis model was induced by ovariectomy, treated with ORPH 150 or 75 mg kg-1. Body weight and bone mineral density (BMD) of rats were measured at the beginning and the end of the experiment, and femoral maximum load was determined immediately after killing. The expression levels of alkaline phosphatase (ALP), Smad4, tartrate acid phosphatase (TRAP), BMP2, Runx2, CPB, ColI and osteocalcin were examined by RT-PCR or western-blotting. HE staining was used to observe the pathological changes in the femurs. Immunohistochemistry was used to detect the expression of ALP and BMP2. All data were analyzed by SPSS 13.0. RESULTS: The results revealed that ORPH had no effect on the weight of normal and osteoporotic rats. ORPH could significantly improve the femur BMD and increase the maximum load of the osteoporotic rats. ORPH could significantly upregulate the expression level of bone formation makers, ALP, osteocalcin, ColI, and Runx2, and downregulate the expression level of bone resorption marker, TRAP. In the ORPH group, the expression levels of BMP2, Smad4, and CPB of key proteins in the TGFß/BMP2 signaling pathway were significantly upregulated. In addition, immunohistochemistry showed that ALP and BMP2 expression in femurs of the ORPH group was stranger. H&E staining showed that ORPH (150 mg kg-1) significantly increased the thickness of trabeculae and decreased fracture risk. CONCLUSION: Collectively, ORPH plays a role in the prevention and treatment of osteoporosis, which may be a potential anti-osteoporosis drug.


Assuntos
Proteína Morfogenética Óssea 2/metabolismo , Materia Medica/uso terapêutico , Osteoporose Pós-Menopausa/tratamento farmacológico , Fator de Crescimento Transformador beta1/metabolismo , Animais , Feminino , Humanos , Materia Medica/farmacologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais
14.
IEEE trans Intell Transp Syst ; 20(7): 2566-2583, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32699534

RESUMO

Although geo-tagged mobility data (e.g., cell phone data and social media data) can be potentially used to estimate individual space-time travel trajectories, they often have low sample rates that only tell travelers' whereabouts at the sparse sample times while leaving the remaining activities to be estimated with interpolation. This study proposes a set of time geography-based measures to quantify the accuracy of the trajectory estimation in a robust manner. A series of measures including activity bandwidth and normalized activity bandwidth are proposed to quantify the possible absolute and relative error ranges between the estimated and the ground truth trajectories that cannot be observed. These measures can be used to evaluate the suitability of the estimated individual trajectories from sparsely sampled geo-tagged mobility data for travel mobility analysis. We suggest cutoff values of these measures to separate useful data with low estimation errors and noisy data with high estimation errors. We conduct theoretical analysis to show that these error measures decrease with sample rates and people's activity ranges. We also propose a lookup table-based interpolation method to expedite the computational time. The proposed measures have been applied to 2013 geo-tagged tweet data in New York City and 2014 cell-phone data in Shenzhen, China. The results illustrate that the proposed measures can provide estimation error ranges for exceptionally large datasets in much shorter times than the benchmark method without using lookup tables. These results also reveal managerial results into the quality of these data for human mobility studies, including their distribution patterns.

15.
J Sep Sci ; 41(2): 560-570, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29098764

RESUMO

To explore the global mechanism of Ermiaowan on hyperuricemia regulation, the holistic function of Ermiaowan for hyperuricemia in rats was firstly assessed by the urinary metabonomics method which was based on ultra-high performance liquid chromatography with electrospray ionization quadrupole time-of-flight mass spectrometry. The urinary targeted metabonomics approach combined with the serum biochemical analysis and histological assay was conducted to verify the research result. As a result, the significant differences in metabolic profiles were observed from Ermiaowan-treated group, model group, and healthy control group by using multivariate statistical approaches. Twenty therapeutic related metabolites were identified in response to the therapeutic effects of Ermiaowan, which were mainly associated with purine metabolism, pyrimidine metabolism, tryptophan metabolism, tricarboxylic acid cycle, and tyrosine metabolism. In addition, the urinary targeted metabonomics study showed that Ermiaowan can better restore the disturbed pathways than Phellodendri cortex and Atractylodis rhizome. The biochemical assay and histopathological assay confirmed that Ermiaowan could significantly reduce uric acid and fibrosis areas of kidney. These results provided new insights into the mechanism of Ermiaowan on hyperuricemia.


Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Hiperuricemia/sangue , Metaboloma , Animais , Biomarcadores/sangue , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Modelos Lineares , Masculino , Metabolômica , Análise Multivariada , Extratos Vegetais/farmacologia , Análise de Componente Principal , Purinas/química , Pirimidinas/química , Controle de Qualidade , Ratos , Ratos Wistar , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização por Electrospray , Triptofano/química
16.
BMC Med Imaging ; 18(1): 7, 2018 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-29724180

RESUMO

BACKGROUND: Multi-contrast images in magnetic resonance imaging (MRI) provide abundant contrast information reflecting the characteristics of the internal tissues of human bodies, and thus have been widely utilized in clinical diagnosis. However, long acquisition time limits the application of multi-contrast MRI. One efficient way to accelerate data acquisition is to under-sample the k-space data and then reconstruct images with sparsity constraint. However, images are compromised at high acceleration factor if images are reconstructed individually. We aim to improve the images with a jointly sparse reconstruction and Graph-based redundant wavelet transform (GBRWT). METHODS: First, a sparsifying transform, GBRWT, is trained to reflect the similarity of tissue structures in multi-contrast images. Second, joint multi-contrast image reconstruction is formulated as a ℓ2, 1 norm optimization problem under GBRWT representations. Third, the optimization problem is numerically solved using a derived alternating direction method. RESULTS: Experimental results in synthetic and in vivo MRI data demonstrate that the proposed joint reconstruction method can achieve lower reconstruction errors and better preserve image structures than the compared joint reconstruction methods. Besides, the proposed method outperforms single image reconstruction with joint sparsity constraint of multi-contrast images. CONCLUSIONS: The proposed method explores the joint sparsity of multi-contrast MRI images under graph-based redundant wavelet transform and realizes joint sparse reconstruction of multi-contrast images. Experiment demonstrate that the proposed method outperforms the compared joint reconstruction methods as well as individual reconstructions. With this high quality image reconstruction method, it is possible to achieve the high acceleration factors by exploring the complementary information provided by multi-contrast MRI.


Assuntos
Encéfalo/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Meios de Contraste , Humanos , Processamento de Sinais Assistido por Computador , Análise de Ondaletas
17.
Sensors (Basel) ; 18(3)2018 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-29509666

RESUMO

Deep convolutional neural networks (CNNs) are successful in single-image super-resolution. Traditional CNNs are limited to exploit multi-scale contextual information for image reconstruction due to the fixed convolutional kernel in their building modules. To restore various scales of image details, we enhance the multi-scale inference capability of CNNs by introducing competition among multi-scale convolutional filters, and build up a shallow network under limited computational resources. The proposed network has the following two advantages: (1) the multi-scale convolutional kernel provides the multi-context for image super-resolution, and (2) the maximum competitive strategy adaptively chooses the optimal scale of information for image reconstruction. Our experimental results on image super-resolution show that the performance of the proposed network outperforms the state-of-the-art methods.

18.
BMC Med Imaging ; 17(1): 6, 2017 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-28095792

RESUMO

BACKGROUND: Low-resolution images may be acquired in magnetic resonance imaging (MRI) due to limited data acquisition time or other physical constraints, and their resolutions can be improved with super-resolution methods. Since MRI can offer images of an object with different contrasts, e.g., T1-weighted or T2-weighted, the shared information between inter-contrast images can be used to benefit super-resolution. METHODS: In this study, an MRI image super-resolution approach to enhance in-plane resolution is proposed by exploring the statistical information estimated from another contrast MRI image that shares similar anatomical structures. We assume some edge structures are shown both in T1-weighted and T2-weighted MRI brain images acquired of the same subject, and the proposed approach aims to recover such kind of structures to generate a high-resolution image from its low-resolution counterpart. RESULTS: The statistical information produces a local weight of image that are found to be nearly invariant to the image contrast and thus this weight can be used to transfer the shared information from one contrast to another. We analyze this property with comprehensive mathematics as well as numerical experiments. CONCLUSION: Experimental results demonstrate that the image quality of low-resolution images can be remarkably improved with the proposed method if this weight is borrowed from a high resolution image with another contrast. Multi-contrast MRI Image Super-resolution with Contrast-invariant Regression Weights.


Assuntos
Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Intensificação de Imagem Radiográfica/métodos , Algoritmos , Meios de Contraste/metabolismo , Humanos
19.
Pharm Biol ; 55(1): 2196-2204, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29115171

RESUMO

CONTEXT: Sika pilose antler type I collagen (SPC-I) have been reported to promote bone marrow mesenchymal stem cell (BMSC) proliferation and differentiation. However, the underlying mechanism is still unclear. OBJECTIVE: This study investigates the molecular mechanisms of SPC-I on the BMSC proliferation and differentiation of osteoblast (OB) in vitro. MATERIAL AND METHODS: The primary rat BMSC was cultured and exposed to SPC-I at different concentrations (2.5, 5.0 and 10.0 mg/mL) for 20 days. The effect of SPC-I on the differentiation of BMSCs was evaluated through detecting the activity of alkaline phosphatase (ALP), ALP staining, collagen I (Col-I) content, and calcified nodules. The markers of osteoblastic differentiation were evaluated using RT-PCR and Western-blot analysis. RESULTS: SPC-I treatment (2.5 mg/mL) significantly increased the proliferation of BMSCs (p < 0.01), whereas, SPC-I (5.0 and 10.0 mg/mL) significantly inhibited the proliferation of BMSCs (p < 0.01). SPC-I (2.5 mg/mL) significantly increased ALP activity and Col-I content (p < 0.01), and increased positive cells in ALP staining and the formation of calcified nodules. Additionally, the gene expression of ALP, Col-I, Osteocalcin (OC), Runx2, Osterix (Osx), ERK1/2, BMP2 and p38-MAPK, along with the protein expression of ERK1/2, p-ERK1/2, p-p38 MAPK were markedly increased in the SPC-I (5.0 mg/mL) treatment group (p < 0.01) compared to the control group. DISCUSSION AND CONCLUSIONS: SPC-I can induce BMSC differentiation into OBs and enhance the function of osteogenesis through ERK1/2 and p38-MAPK signal transduction pathways and regulating the gene expression of osteogenesis-specific transcription factors.


Assuntos
Chifres de Veado/química , Diferenciação Celular/efeitos dos fármacos , Colágeno Tipo I/farmacologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Animais , Western Blotting , Proliferação de Células/efeitos dos fármacos , Colágeno Tipo I/administração & dosagem , Colágeno Tipo I/isolamento & purificação , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Células-Tronco Mesenquimais/citologia , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Osteoblastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
20.
Zhongguo Zhong Yao Za Zhi ; 42(22): 4408-4413, 2017 Nov.
Artigo em Zh | MEDLINE | ID: mdl-29318843

RESUMO

This paper is aims to clarify the spatial distribution of high quality medicinal materials Schisandrae Chinensis Fructus. Based on investigation and field investigation, the samples and distribution information of Schisandrae Chinensis Fructus were collected. Based on the data of four kinds of lignin chemical constituents, ecological environment factors and spatial distribution data of Schisandrae Chinensis Fructus, using GIS technology, maximum information entropy model and SPSS statistical analysis method for regionalizing the quality of Schisandrae Chinensis Fructus. The results showed that Schisandrae Chinensis Fructus was mainly distributed in the northeast of Liaoning, east of Jilin, east of Heilongjiang. The content of schisandrin was higher in the samples from northeastern part of Jilin province and the northeastern part of Liaoning province, The content of deoxyschizandrin was higher in the samples from middle of Jilin province and northeastern Hebei province, where the content of schisandrin B was higher in the samples from Jilin area, The higher schisantherin A sample were from southeast of Jilin and northeast of Liaoning. Considering the content of four components in Schisandrae Chinensis Fructus, the quality of Schisandrae Chinensis Fructus was concentrated in the southeast of Jilin and the northeastern part of Liaoning.


Assuntos
Medicamentos de Ervas Chinesas/normas , Sistemas de Informação Geográfica , Schisandra/química , China , Frutas/química , Plantas Medicinais/química , Controle de Qualidade
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