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1.
J Multidiscip Healthc ; 17: 3743-3751, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39104383

RESUMEN

Objective: Sarcopenia is more common in maintenance hemodialysis (MHD) patients, and the aim of this study is to analyze the risk factors associated with sarcopenia in MHD patients, along with its correlation to emotional status and quality of life. Methods: This is a cross-sectional cohort study. A total of 111 MHD patients who were treated in the Department of Nephrology of our hospital were selected as the study subjects by convenience sampling. The quality of life and emotional status were evaluated by health survey scale (SF-36), self-rating anxiety scale (SAS) and self-rating depression scale (SDS). Regression analysis was used to explore the influencing factors of sarcopenia. Correlation analysis was used to investigate the correlation between sarcopenia and quality of life and emotional status. Results: The prevalence of sarcopenia was 59.8%. The results showed that age, gender, body mass index (BMI), dialysis time, economic status, marital status and pre-dialysis creatinine were significant factors affecting the development of sarcopenia in hemodialysis patients (p<0.05). The SF-36 total score was significantly lower in the sarcopenia group (72.05±12.28 vs 78.03±10.55) than in the non-sarcopenia group, but the anxiety scale score (52.97±4.67 vs 36.2±3.36) and depression scale score (57.67±4.58 vs 38.71±3.77) were significantly higher than those in the non-sarcopenia group (p< 0.001). Correlation analysis showed that sarcopenia was positively correlated with SAS and SDS scores and negatively correlated with SF-36 total score (p < 0.05). Conclusion: The risk of sarcopenia was higher among MHD patients who were older, male, single, with a longer MHD duration, lower economic status, lower BMI, comorbid diabetes and lower levels of creatinine.

2.
Mol Ecol ; : e17504, 2024 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-39166453

RESUMEN

The Venus flytrap sea anemone Actinoscyphia liui inhabits the nutrient-limited deep ocean in the tropical western Pacific. Compared with most other sea anemones, it has undergone a distinct modification of body shape similar to that of the botanic flytrap. However, the molecular mechanism by which such a peculiar sea anemone adapts to a deep-sea oligotrophic environment is unknown. Here, we report the chromosomal-level genome of A. liui constructed from PacBio and Hi-C data. The assembled genome is 522 Mb in size and exhibits a continuous scaffold N50 of 58.4 Mb. Different from most other sea anemones, which typically possess 14-18 chromosomes per haplotype, A. liui has only 11. The reduced number of chromosomes is associated with chromosome fusion, which likely represents an adaptive strategy to economize energy in oligotrophic deep-sea environments. Comparative analysis with other deep-sea sea anemones revealed adaptive evolution in genes related to cellular autophagy (TMBIM6, SESN1, SCOCB and RPTOR) and mitochondrial energy metabolism (MDH1B and KAD2), which may aid in A. liui coping with severe food scarcity. Meanwhile, the genome has undergone at least two rounds of expansion in gene families associated with fast synaptic transmission, facilitating rapid responses to water currents and prey. Positive selection was detected on putative phosphorylation sites of muscle contraction-related proteins, possibly further improving feeding efficiency. Overall, the present study provides insights into the molecular adaptation to deep-sea oligotrophic environments and sheds light upon potential effects of a novel morphology on the evolution of Cnidaria.

3.
Crit Care Med ; 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38940646

RESUMEN

OBJECTIVES: The objective of this study was to investigate the dynamic profiles of myocardial injury biomarkers and their association with mortality in patients with severe fever with thrombocytopenia syndrome (SFTS). DESIGN: A retrospective cohort study. SETTINGS: Union Hospital in Wuhan, China. PATIENTS: A total of 580 patients with SFTS, observed between May 2014 and December 2021, were included in the final analysis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: In total, 580 patients with SFTS were enrolled in the study, comprised of 469 survivors and 111 nonsurvivors, with a 21-day fatality rate of 19.1%. The elevation of troponin I (TnI) was observed in 61.6% patients (357/580) with SFTS upon admission, and 68.4% patients (397/580) developed an abnormal TnI level during hospitalization. Multivariate logistic regression identified age, viral load, platelet count, creatinine level, and TnI level as potential risk factors for mortality in patients with SFTS. The results of restricted cubic splines revealed that when the TnI level (baseline TnI: 1.55 [lg (ng/L+1)], peak value: TnI 1.90 [lg (ng/L+1)]) exceeded a certain threshold, the predicted mortality of patients with SFTS increased alongside the rise in TnI levels. Mortality rate surpassed 40% among patients with SFTS with TnI greater than or equal to 10 times the upper limit of normal at admission (43.8%) or during hospitalization (41.7%). Older age, a history of cardiovascular disease, and higher d-dimer levels were potential risk factors for elevated TnI levels in patients with SFTS. CONCLUSIONS: Elevated TnI levels were prevalent among patients with SFTS and were strongly associated with an increased risk of mortality.

4.
Heliyon ; 10(8): e29224, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38655308

RESUMEN

Introduction: Antiphospholipid syndrome (APS) is an autoimmune disorder associated with thrombosis and adverse obstetric outcomes. Early diagnosis and intervention can improve pregnancy outcomes to some extent, but current results are unsatisfactory. Exosomes, containing biomacromolecules relevant to reproduction, play essential roles in pregnancy. However, research progress on their involvement in APS remains limited. Objectives: This study aims to investigate protein profile changes in plasma exosomes and identify potential biomarkers for obstetric APS. Methods: We employed tandem mass tag (TMT) markers to analyze exosome protein profiles from 6 healthy early pregnant women and 6 early-stage APS patients. Quantitative proteomics analysis was conducted using the Maxquant search engine. Results: Differential expression analysis identified 51 upregulated and 22 downregulated proteins in plasma exosomes from early pregnant women with APS, such as serpin peptidase inhibitor C1/A1/A7, apolipoprotein 1/2, orosomucoid 1/2 and apolipoprotein H. Kyoto Encyclopedia of Genes and Genomes analysis shows that differentially expressed proteins are enriched in the PPAR signaling pathway and staphylococcus aureus infection pathway. Enrichment analysis indicated associations with glycerolipid biosynthesis, vitamin transport, and negative regulation of very-low-density lipoprotein particle remodeling. Conclusion: Our study highlights alterations in the protein profiles of plasma exosomes in APS pregnant patients and proposes potential biomarkers, offering insights for early diagnosis and treatment and improving reproductive outcomes.

5.
Gene ; 908: 148231, 2024 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-38309316

RESUMEN

Recurrent miscarriages (RM) generally refer to two or more consecutive pregnancy losses. The risk of miscarriages grows with its frequency of occurrences, so as the future obstetric complications or longer-term health problems for patients. Most previous researches sought to discover the etiology of RM by making comparisons between patients with RM and fertile women. Our study collected decidua tissues from patients with RM and single miscarriage (SM) for transcriptome sequencing analysis and aimed at identifying vital factors contributing to additional miscarriages after previous miscarriage. Between the RM and SM group, a total of 122 differentially expressed genes (DEGs) were detected and pathways associated with cell adhesion and ECM remodeling were particularly enriched in the RM group, which indicated abnormally activated fibrogenesis process. Particularly, the enhancement of ITGB6, EGFLAM and COL3A1 in the RM group were validated by RT-qPCR. Our study discovered that fibrogenesis, which might be caused by intrauterine manipulation, could lead to recurrent miscarriages after a previous miscarriage. Therefore, we encourage higher attention to thorough prevention and prompt remedies towards fibrotic disorders related diseases.


Asunto(s)
Aborto Habitual , Embarazo , Humanos , Femenino , Aborto Habitual/genética , Perfilación de la Expresión Génica
6.
Mitochondrial DNA B Resour ; 8(9): 977-980, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37727835

RESUMEN

Paracondylactis sinensis Carlgren, 1934 (Actiniidae, Actiniaria) is an edible sea anemone in China. Their wild population has intensively decreased in recent years due to overharvesting. In this study, the complete mitochondrial genome of this economic species collected in the coast of Zhejiang, China is sequenced and obtained using high throughput methods. The total length of this circular molecule is 20,786 bp. Thirteen protein coding genes, two ribosomal RNA genes, two transfer RNA (tRNATrp, tRNAMet) genes and a putative ORF are annotated in it. Phylogenetic analysis based on the amino acids of mitochondrial genomes indicates that this species belongs to the family of Actiniidae. This result is consistent with the previous work that identified the edible sea anemone as Paracondylactis sinensis although it has always been recognized as Calliactis sinensis (of family Hormathiidae) in most Chinese reports. Overall, the mitochondrial genome produced in this study assists in clarifying the phylogenetic status of this sea anemone and provides a molecular foundation for future protection and breeding work.

7.
Environ Sci Technol ; 57(26): 9884-9893, 2023 07 04.
Artículo en Inglés | MEDLINE | ID: mdl-37319319

RESUMEN

Transition metal sulfides have exhibited remarkable advantages in gaseous elemental mercury (Hg0) capture under high SO2 atmosphere, whereas the weak thermal stability significantly inhibits their practical application. Herein, a novel N,N-dimethylformamide (DMF) insertion strategy via crystal growth engineering was developed to successfully enhance the Hg0 capture ability of MoS2 at an elevated temperature for the first time. The DMF-inserted MoS2 possesses an edge-enriched structure and an expanded interlayer spacing (9.8 Å) and can maintain structural stability at a temperature as high as 272 °C. The saturated Hg0 adsorption capacities of the DMF-inserted MoS2 were measured to be 46.91 mg·g-1 at 80 °C and 27.40 mg·g-1 at 160 °C under high SO2 atmosphere. The inserted DMF molecules chemically bond with MoS2, which prevents possible structural collapse at a high temperature. The strong interaction of DMF with MoS2 nanosheets facilitates the growth of abundant defects and edge sites and enhances the formation of Mo5+/Mo6+ and S22- species, thereby improving the Hg0 capture activity at a wide temperature range. Particularly, Mo atoms on the (100) plane represent the strongest active sites for Hg0 oxidation and adsorption. The molecule insertion strategy developed in this work provides new insights into the engineering of advanced environmental materials.


Asunto(s)
Mercurio , Molibdeno , Disulfuros , Sulfuros
8.
Iran J Basic Med Sci ; 26(3): 351-358, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36865047

RESUMEN

Objectives: To explore the ability and underlying molecular mechanisms involved in the protective effects of Baicalin (BA) against L-Glutamate-induced mouse hippocampal neuron cell line HT-22. Materials and Methods: The cell injury model of HT-22 cells was induced by L-glutamate, and cell viability and damage were detected by CCK-8 and LDH assays. Generation of intracellular reactive oxygen species (ROS) was measured by DCFH-DA in situ fluorescence method. The SOD activity and MDA concentration in the supernatants were determined by WST-8 and colorimetric method, respectively. Furthermore, Western blot and real-time qPCR analysis were utilized to detect the expression levels of the Nrf2/HO-1 signaling pathway and NLRP3 inflammasome proteins and genes. Results: L-Glutamate exposure induced cell injuries in HT-22 cells, and the concentration of 5 mM L-Glutamate was chosen to be the modeling condition. Co-treatment with BA significantly promoted cell viability and reduced LDH release in a dose-dependent manner. In addition, BA attenuated the L-Glutamate-induced injuries by decreasing the ROS production and MDA concentration, while increasing the SOD activity. Moreover, we also found that BA treatment up-regulated the gene and protein expression of Nrf2 and HO-1, and then inhibited the expression of NLRP3. Conclusion: Our study found that BA could relieve oxidative stress damage of HT-22 cells induced by L-Glutamate, and the mechanism might be related to the activation of Nrf2/HO-1 and inhibition of NLRP3 inflammasome.

9.
Artículo en Inglés | MEDLINE | ID: mdl-36320561

RESUMEN

The rapid development of deep-learning methods in medical imaging has called for an analysis method suitable for non-linear and data-dependent algorithms. In this work, we investigate a local linearity analysis where a complex neural network can be represented as piecewise linear systems. We recognize that a large number of neural networks consists of alternating linear layers and rectified linear unit (ReLU) activations, and are therefore strictly piecewise linear. We investigated the extent of these locally linear regions by gradually adding perturbations to an operating point. For this work, we explored perturbations based on image features of interest, including lesion contrast, background, and additive noise. We then developed strategies to extend these strictly locally linear regions to include neighboring linear regions with similar gradients. Using these approximately linear regions, we applied singular value decomposition (SVD) analysis to each local linear system to investigate and explain the overall nonlinear and data-dependent behaviors of neural networks. The analysis was applied to an example CT denoising algorithm trained on thorax CT scans. We observed that the strictly local linear regions are highly sensitive to small signal perturbations. Over a range of lesion contrast from 0.007 to 0.04 mm-1, there is a total of 33992 linear regions. The Jacobians are also shift-variant. However, the Jacobians of neighboring linear regions are very similar. By combining linear regions with similar Jacobians, we narrowed down the number of approximately linear regions to four over lesion contrast from 0.001 to 0.08 mm-1. The SVD analysis to different linear regions revealed denoising behavior that is highly dependent on the background intensity. Analysis further identified greater amount of noise reduction in uniform regions compared to lesion edges. In summary, the local linearity analysis framework we proposed has the potential for us to better characterize and interpret the non-linear and data-dependent behaviors of neural networks.

10.
J Clin Transl Hepatol ; 10(5): 825-834, 2022 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-36304508

RESUMEN

Background and Aims: Patients with severe fever with thrombocytopenia syndrome (SFTS) commonly show liver function impairment. This study aimed to characterize the liver function indices in SFTS patients and investigate their association with mortality. Methods: Clinical information and laboratory results of 459 laboratory-confirmed SFTS patients, including 78 deceased and 381 surviving patients, were retrospectively analyzed. To explore the infectivity of SFTS caused by novel Bunyavirus (SFTSV) in hepatocytes, Huh7 human hepatoma cells were infected with various concentrations of SFTSV in vitro. Results: The proportion of SFTS patients developing liver injury during hospitalization was 73.2% (336/459); the hepatocellular injury was the predominant type. The median time to occurrence of liver injury from disease onset was 8 d. Liver injury in the deceased group occurred earlier than that in the surviving group. Alanine aminotransferase (ALT) level between 2-5 times upper limit of normal (ULN) at 4-6 d and between 5-15 ULN at 7-12 d of disease course were independent predictors of mortality. Alkaline phosphatase (ALP) >2 ULN at 7-9 d and elevated ALP at 10-12 days after disease onset were risk factors for death. ALT and aspartate transaminase (AST) levels were correlated with lymphocyte count and platelet-to-lymphocyte ratio (PLR). Total bilirubin (TB), ALT, AST levels showed positive correlation with viral load. In the in vitro experiment, SFTSV infected and replicated inside Huh7 cells. Conclusions: Liver injury is common in SFTS patients. ALT and ALP were independent predictors of SFTS-related mortality. Frequent monitoring and evaluation of liver function indices are needed for SFTS patients.

11.
Environ Sci Technol ; 56(19): 13664-13674, 2022 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-36154115

RESUMEN

Copper sulfide (CuS) has received increasing attention as a promising material in gaseous elemental mercury (Hg0) capture, yet how to enhance its activity at elevated temperature remains a great challenge for practical application. Herein, simultaneous improvement in the activity and thermal stability of CuS toward Hg0 capture was successfully achieved for the first time by controlling the crystal growth. CuS with a moderate crystallinity degree of 68.8% showed a disordered structure yet high thermal stability up to 180 °C. Such disordered CuS can maintain its Hg0 capture activity stable during longtime test at a wide temperature range from 60 to 180 °C and displayed strong resistance to SO2 (6%) and H2O (8%). The significant improvement can be attributed to the synergistic effect of a moderately crystalline nature and a unique sulfur-rich interface. Moderate crystallinity guarantees the thermal stability of CuS and the presence of abundant defects, in which copper vacancy enhances significantly the Hg0 capture activity. The sulfur-rich interface enables CuS to provide plentiful highly active Sx2- sites for Hg0 adsorption. The interrelation between structure, reactivity, and thermal stability clarified in this work broadens the understanding toward Hg0 oxidation and adsorption over CuS and provides new insights into the rational design and engineering of advanced environmental materials.

12.
J Environ Sci (China) ; 119: 44-49, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35934464

RESUMEN

The presence of SO2 display significant effect on the mercury (Hg) adsorption ability of carbon-based sorbent. Yet the adsorption and oxidation of SO2 on carbon with oxygen group, as well as the roles of different sulfur oxide groups in Hg adsorption have heretofore been unclear. The formation of sulfur oxide groups by SO2 and their effects on Hg adsorption on carbon was detailed examined by the density functional theory. The results show that SO2 can be oxidized into SO3 by oxygen group on carbon surface. Both C-SO2 and C-SO3 can improve Hg adsorption on carbon site, while the promotive effect of C-SO2 is stronger than C-SO3. Electron density difference analyses reveal that sulfur oxide groups enhance the charge transfer ability of surface unsaturated carbon atom, thereby improving Hg adsorption. The experimental results confirm that surface active groups formed by SO2 adsorption is more active for Hg adsorption than the groups generated by SO3.


Asunto(s)
Mercurio , Adsorción , Carbono , Oxígeno , Óxidos de Azufre
13.
Artículo en Inglés | MEDLINE | ID: mdl-35601024

RESUMEN

Recent years have seen the increasing application of deep learning methods in medical imaging formation, processing, and analysis. These methods take advantage of the flexibility of nonlinear neural network models to encode information and features in ways that can outperform conventional approaches. However, because of the nonlinear nature of this processing, images formed by neural networks have properties that are highly data-dependent and difficult to analyze. In particular, the generalizability and robustness of these approaches can be difficult to ascertain. In this work, we analyze a class of neural networks that use only piece-wise linear activation functions. This class of networks can be represented by locally linear systems where the linear properties are highly data-dependent - allowing, for example, estimation of noise in image output via standard propagation methods. We propose a nonlinearity index metric that quantifies the fidelity of a local linear approximation of trained models based on specific input data. We applied this analysis to three example CT denoising CNNs to analytically predict the noise properties in the output images. We found that the proposed nonlinearity metric highly correlates with the accuracy of noise predictions. The analysis proposed in this work provides theoretical understanding of the nonlinear behavior of neural networks and enables performance prediction and quantitation under certain conditions.

14.
Artículo en Inglés | MEDLINE | ID: mdl-35585939

RESUMEN

The proliferation of deep learning image processing calls for a quantitative image quality assessment framework that is suitable for nonlinear, data-dependent algorithms. In this work, we propose a method to systematically evaluate the system and noise responses such that the nonlinear transfer properties can be mapped out. The method involves sampling of lesion perturbations as a function of size, contrast, as well as clinically relevant features such as shape and texture that may be important for diagnosis. We embed the perturbations in backgrounds of varying attenuation levels, noise magnitude and correlation that are associated with different patient anatomies and imaging protocols. The range of system and noise response are further used to evaluate performance for clinical tasks such as signal detection and classification. We performed the assessment for an example CNN-denoising algorithm for low does lung CT screening. The system response of the CNN-denoising algorithm exhibits highly nonlinear behavior where both contrast and higher order lesion features such as spiculated boundaries are not reliably represented for lesions perturbations with small size and low contrast. The noise properties are potentially highly nonstationary, and should be assumed to be the same between the signal-present and signal-absent images. Furthermore, we observer a high degree dependency of both system and noise response on the background attenuation levels. Inputs around zeros are effectively imposed a non-negativity constraint; transfer properties for higher background levels are highly variable. For a detection task, CNN-denoised images improved detectability index by 16-18% compared to low dose CT inputs. For classification task between spiculated and smooth lesions, CNN-denoised images result in a much larger improvement up to 50%. The performance assessment framework propose in this work can systematically map out the nonlinear transfer functions for deep learning algorithms and can potentially enable robust deployment of such algorithms in medical imaging applications.

15.
Infect Drug Resist ; 15: 1019-1025, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35299849

RESUMEN

Histiocytic necrotizing lymphadenitis (HNL) is a self-limiting inflammatory disease presenting with fever and cervical lymphadenopathy. However, no case of HNL with confirmed bacterial infection has been reported. A 38-year-old man was admitted to our hospital owing to an intermittent fever from 8 days. He was diagnosed with Graves hyperthyroidism 3 months prior and began taking methimazole tablets orally. Physical examination revealed superficial lymphadenopathy and goiter of the thyroid (grade II). Blood routine showed a decrease in peripheral blood cells, including significant reduction in leukocytes and platelets. A bone marrow culture identified a very rare pathogen, Cupriavidus pauculus, but the antibiotic effect of meropenem was unsatisfactory. Biopsy of the left cervical lymph node revealed HNL, and the patient had no fever after using glucocorticoids. This case report indicates that clinicians should be aware of the coexistence of HNL and bacterial infections, especially in patients with Graves hyperthyroidism.

16.
Artículo en Inglés | MEDLINE | ID: mdl-37051612

RESUMEN

Printed phantoms hold great potential as a tool for examining task-based image quality of x-ray imaging systems. Their ability to produce complex shapes rendered in materials with adjustable attenuation coefficients allows a new level of flexibility in the design of tasks for the evaluation of physical imaging systems. We investigate performance in a fine "boundary discrimination" task in which fine features at the margin of a clearly visible "lesion" are used to classify the lesion as malignant or benign. These tasks are appealing because of their relevance to clinical tasks, and because they typically emphasize higher spatial frequencies relative to more common lesion detection tasks. A 3D printed phantom containing cylindrical shells of varying thickness was used to generate lesions profiles that differed in their edge profiles. This was intended to approximate lesions with indistinct margins that are clinically associated with malignancy. Wall thickness in the phantom ranged from 0.4mm to 0.8mm, which allows for task difficulty to be varied by choosing different thicknesses to represent malignant and benign lesions. The phantom was immersed in a tub filled with water and potassium phosphate to approximate the attenuating background, and imaged repeatedly on a benchtop cone-beam CT scanner. After preparing the image data (reconstruction, ROI Selection, sub-pixel registration), we find that the mean frequency of the lesion profile is 0.11 cyc/mm. The mean frequency of the lesion-difference profile, representative of the discrimination task, is approximately 6 times larger. Model observers show appropriate dose performance in these tasks as well.

17.
Artículo en Inglés | MEDLINE | ID: mdl-38187806

RESUMEN

Non-circular orbits in cone-beam CT (CBCT) imaging are increasingly being studied for potential benefits in field-of-view, dose reduction, improved image quality, minimal interference in guided procedures, metal artifact reduction, and more. While modern imaging systems such as robotic C-arms are enabling more freedom in potential orbit designs, practical implementation on such clinical systems remains challenging due to obstacles in critical stages of the workflow, including orbit realization, geometric calibration, and reconstruction. In this work, we build upon previous successes in clinical implementation and address key challenges in the geometric calibration stage with a novel calibration method. The resulting workflow eliminates the need for prior patient scans or dedicated calibration phantoms, and can be conducted in clinically relevant processing times.

18.
Med Phys ; 48(10): 6375-6387, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34272890

RESUMEN

PURPOSE: Spectral CT uses energy-dependent measurements that enable material discrimination in addition to reconstruction of structural information. Flat-panel detectors (FPDs) have been widely used in dedicated and interventional systems to deliver high spatial resolution, volumetric cone-beam CT (CBCT) in compact and OR-friendly designs. In this work, we derive a model-based method that facilitates high-resolution material decomposition in a spectral CBCT system equipped with a prototype dual-layer FPD. Through high-fidelity modeling of multilayer detector, we seek to avoid resolution loss that is present in more traditional processing and decomposition approaches. METHOD: A physical model for spectral measurements in dual-layer flat-panel CBCT is developed including layer-dependent differences in system geometry, spectral sensitivities, and detector blur (e.g., due to varied scintillator thicknesses). This forward model is integrated into a model-based material decomposition (MBMD) method based on minimization of a penalized weighted least-squared (PWLS) objective function. The noise and resolution performance of this approach was compared with traditional projection-domain decomposition (PDD) and image-domain decomposition (IDD) approaches as well as one-step MBMD with lower-fidelity models that use approximated geometry, projection interpolation, or an idealized system geometry without system blur model. Physical studies using high-resolution three-dimensional (3D)-printed water-iodine phantoms were conducted to demonstrate the high-resolution imaging performance of the compared decomposition methods in iodine basis images and synthetic monoenergetic images. RESULTS: Physical experiments demonstrate that the MBMD methods incorporating an accurate geometry model can yield higher spatial resolution iodine basis images and synthetic monoenergetic images than PDD and IDD results at the same noise level. MBMD with blur modeling can further improve the spatial-resolution compared with the decomposition results obtained with IDD, PDD, and MBMD methods with lower-fidelity models. Using the MBMD without or with blur model can increase the absolute modulation at 1.75 lp/mm by 10% and 22% compared with IDD at the same noise level. CONCLUSION: The proposed model-based material decomposition method for a dual-layer flat-panel CBCT system has demonstrated an ability to extend high-resolution performance through sophisticated detector modeling including the layer-dependent blur. The proposed work has the potential to not only facilitate high-resolution spectral CT in interventional and dedicated CBCT systems, but may also provide the opportunity to evaluate different flat-panel design trade-offs including multilayer FPDs with mismatched geometries, scintillator thicknesses, and spectral sensitivities.


Asunto(s)
Tomografía Computarizada de Haz Cónico Espiral , Tomografía Computarizada de Haz Cónico , Análisis de los Mínimos Cuadrados , Modelos Teóricos , Fantasmas de Imagen
19.
Iperception ; 12(3): 20416695211020768, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34104386

RESUMEN

Previous studies have demonstrated that exogenous attention decreases audiovisual integration (AVI); however, whether the AVI is different when exogenous attention is elicited by bimodal and unimodal cues and its aging effect remain unclear. To clarify this matter, 20 older adults and 20 younger adults were recruited to conduct an auditory/visual discrimination task following bimodal audiovisual cues or unimodal auditory/visual cues. The results showed that the response to all stimulus types was faster in younger adults compared with older adults, and the response was faster when responding to audiovisual stimuli compared with auditory or visual stimuli. Analysis using the race model revealed that the AVI was lower in the exogenous-cue conditions compared with the no-cue condition for both older and younger adults. The AVI was observed in all exogenous-cue conditions for the younger adults (visual cue > auditory cue > audiovisual cue); however, for older adults, the AVI was only found in the visual-cue condition. In addition, the AVI was lower in older adults compared to younger adults under no- and visual-cue conditions. These results suggested that exogenous attention decreased the AVI, and the AVI was lower in exogenous attention elicited by bimodal-cue than by unimodal-cue conditions. In addition, the AVI was reduced for older adults compared with younger adults under exogenous attention.

20.
ACS Omega ; 6(18): 12343-12350, 2021 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-34056386

RESUMEN

The utilization of O2 and NO in flue gas to activate the raw porous carbon with auxiliary plasma contributes to an effective mercury (Hg)-removal strategy. The lack of in-depth knowledge on the Hg adsorption mechanism over the O2-/NO-codoped porous carbon severely limits the development of a more effective Hg removal method and the potential application. Therefore, the generation processes of functional groups on the surface during plasma treatment were investigated and the detailed roles of different groups in Hg adsorption were clarified. The theoretical results suggest that the formation of functional groups is highly exothermic and they preferentially form on a carbon surface, and then affect Hg adsorption. The active groups affect Hg adsorption in a different manner, which depends on their nature. All of these active groups can improve Hg adsorption by enhancing the interaction of Hg with a surface carbon atom. Particularly, the preadsorbed NO2 and O3 groups can react directly with Hg by forming HgO. The experimental results confirm that the active groups cocontribute to the high Hg removal efficiency of O2-/NO-codoped porous carbon. In addition, the mercury temperature-programmed desorption results suggest that there are two forms of mercury present on O2-/NO-codoped porous carbon, including a carbon-bonded Hg atom and HgO.

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