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1.
Planta ; 259(4): 89, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38467941

RESUMO

MAIN CONCLUSION: Taiwan oil millet has two types of epicuticular wax: platelet wax composed primarily of octacosanol and filament wax constituted essentially by the singular compound of octacosanoic acid. Taiwan oil millet (TOM-Eccoilopus formosanus) is an orphan crop cultivated by the Taiwan indigenous people. It has conspicuous white powder covering its leaf sheath indicating abundant epicuticular waxes, that may contribute to its resilience. Here, we characterized the epicuticular wax secretion in TOM leaf blade and leaf sheath using various microscopy techniques, as well as gas chromatography to determine its composition. Two kinds of waxes, platelet and filaments, were secreted in both the leaf blades and sheaths. The platelet wax is secreted ubiquitously by epidermal cells, whereas the filament wax is secreted by a specific cell called epidermal cork cells. The newly developed filament waxes were markedly re-synthesized by the epidermal cork cells through papillae protrusions on the external periclinal cell wall. Ultrastructural images of cork cell revealed the presence of cortical endoplasmic reticulum (ER) tubules along the periphery of plasma membrane (PM) and ER-PM contact sites (EPCS). The predominant wax component was a C28 primary alcohol in leaf blade, and a C28 free fatty acid in the leaf sheath, pseudopetiole and midrib. The wax morphology present in distinct plant organs corresponds to the specific chemical composition: platelet wax composed of alcohols exists mainly in the leaf blade, whereas filament wax constituted mainly by the singular compound C28 free fatty acids is present abundantly in leaf sheath. Our study clarifies the filament wax composition in relation to a previous study in sorghum. Both platelet and filament waxes comprise a protection barrier for TOM.


Assuntos
Milhetes , Sorghum , Humanos , Taiwan , Microscopia Eletrônica de Varredura , Sorghum/metabolismo , Ceras/metabolismo , Folhas de Planta/metabolismo , Epiderme Vegetal/metabolismo
2.
Sci Rep ; 14(1): 4639, 2024 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-38409316

RESUMO

Knowledge regarding the ligament footprints in the canine stifle is essential for biomechanical modeling of the joint and patient-specific surgical planning for anatomical ligament reconstruction. The present study aimed to establish and evaluate deformable shape templates (DSTs) of the femur and tibia with footprints of the cruciate and collateral ligaments embedded for the noninvasive estimation of ligament footprint positions. To this end, a data set of computed tomography (CT)-derived surface models of the femur and tibia were established and used to build statistical shape models (SSMs). The contours of the stifle ligaments were obtained from CT scans of 27 hindlimb specimens with radio-opaque markings on the ligament footprints. The DST, constructed by embedding averaged footprint contours into the SSM, was used to estimate subject-specific ligament footprints in a leave-one-out cross-validation framework. The DST predictions were compared with those derived from radio-opaque-marked footprints. The results showed that the averaged Euclidean distances between the estimated and reference footprint centroids were less than 1.2 mm for the cruciate ligaments and 2.0 mm for the collateral ligaments. The DST appeared to provide a feasible alternative approach for noninvasively estimating the footprints of the stifle ligaments in vivo.


Assuntos
Articulação do Joelho , Joelho de Quadrúpedes , Animais , Cães , Humanos , Joelho de Quadrúpedes/diagnóstico por imagem , Joelho de Quadrúpedes/cirurgia , Ligamentos Articulares , Tíbia/diagnóstico por imagem , Fêmur/diagnóstico por imagem , Fenômenos Biomecânicos
3.
Int J Med Sci ; 21(1): 107-122, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38164360

RESUMO

NF-κB activation is pivotal for the excess inflammation causing the critical condition and mortality of respiratory viral infection patients. This study was aimed to evaluate the effect of a banana plant extract (BPE) on suppressing NF-κB activity and acute lung inflammatory responses in mice induced by a synthetic double-stranded RNA viral mimetic, polyinosinic-polycytidylic acid (poly (I:C)). The inflammatory responses were analyzed by immunohistochemistry and HE stains and ELISA. The NF-κB activities were detected by immunohistochemistry in vivo and immunofluorescence and Western blot in vitro. Results showed that BPE significantly decreased influx of immune cells (neutrophils, lymphocytes, and total WBC), markedly suppressed the elevation of pro-inflammatory cytokines and chemokines (IL-6, RANTES, IFN-γ, MCP-1, keratinocyte-derived chemokine, and IL-17), and restored the diminished anti-inflammatory IL-10 in the bronchoalveolar lavage fluid (BALF) of poly (I:C)-stimulated mice. Accordingly, HE staining revealed that BPE treatment alleviated poly (I:C)-induced inflammatory cell infiltration and histopathologic changes in mice lungs. Moreover, immunohistochemical analysis showed that BPE reduced the pulmonary IL-6, CD11b (macrophage marker), and nuclear NF-κB p65 staining intensities, whilst restored that of IL-10 in poly (I:C)-stimulated mice. In vitro, BPE antagonized poly(I:C)-induced elevation of IL-6, nitric oxide, reactive oxygen species, NF-κB p65 signaling, and transient activation of p38 MAPK in human lung epithelial-like A549 cells. Taken together, BPE ameliorated viral mimic poly(I:C)-induced acute pulmonary inflammation in mice, evidenced by reduced inflammatory cell infiltration and regulation of both pro- and anti-inflammatory cytokines. The mechanism of action might closely associate with NF-κB signaling inhibition.


Assuntos
Musa , Pneumonia , Camundongos , Humanos , Animais , NF-kappa B , Poli I-C/farmacologia , Poli I-C/uso terapêutico , Interleucina-10 , Interleucina-6 , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Citocinas , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Quimiocinas , Anti-Inflamatórios/uso terapêutico
4.
Pest Manag Sci ; 80(3): 1533-1546, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37964702

RESUMO

BACKGROUND: Spodoptera frugiperda, a global agricultural pest, can be effectively controlled through the sterile insect technique. However, exposure to low-dose radiation below the sterilization threshold may induce hormetic effects. Here, the biphasic aspects of the fertile progeny population of S. frugiperda were analyzed using an age-stage, two-sex life table after dosing male and female pupae with 10-350 Gy gamma radiation. RESULTS: The parental sterilizing dose for 6-day-old female and male pupae was 200 and 350 Gy, respectively. The total longevity, pre-adult survival rate, net reproduction rate, and intrinsic growth rate of the offspring population increased with decreasing radiation doses from 250 to 10 Gy. Offspring population of parents treated with low doses of 10-100 Gy showed better life table parameters compared to non-irradiated controls. Females and males fecundity irradiated with 10, 50, and 100 Gy and 10 Gy, respectively, exceeded controls, producing 2339.4, 2726.4, 2311, and 2369 eggs, as opposed to 1802.9 eggs produced by the controls. Males irradiated with 10 Gy displayed the highest intrinsic rates of increase and net reproduction rate, at 0.1709 and 682.3, respectively. Projections from the survival rate and fecundity indicated that female and male S. frugiperda populations after 10 Gy irradiation may grow considerably faster than the controls. CONCLUSION: This study explores the hormetic effects of low-dose radiation on S. frugiperda through life table analysis, while providing enhancements for utilizing substerilizing gamma dose in a modified F1 sterility technique. © 2023 Society of Chemical Industry.


Assuntos
Infertilidade , Mariposas , Animais , Masculino , Feminino , Spodoptera , Tábuas de Vida , Fertilidade
5.
Int J Mol Sci ; 24(8)2023 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-37108239

RESUMO

Osteoarthritis (OA) is a degenerative disease that causes pain, cartilage deformation, and joint inflammation. Mesenchymal stem cells (MSCs) are potential therapeutic agents for OA treatment. However, the 2D culture of MSCs could potentially affect their characteristics and functionality. In this study, calcium-alginate (Ca-Ag) scaffolds were prepared for human adipose-derived stem cell (hADSC) proliferation with a homemade functionally closed process bioreactor system; the feasibility of cultured hADSC spheres in heterologous stem cell therapy for OA treatment was then evaluated. hADSC spheres were collected from Ca-Ag scaffolds by removing calcium ions via ethylenediaminetetraacetic acid (EDTA) chelation. In this study, 2D-cultured individual hADSCs or hADSC spheres were evaluated for treatment efficacy in a monosodium iodoacetate (MIA)-induced OA rat model. The results of gait analysis and histological sectioning showed that hADSC spheres were more effective at relieving arthritis degeneration. The results of serological and blood element analyses of hADSC-treated rats indicated that the hADSC spheres were a safe treatment in vivo. This study demonstrates that hADSC spheres are a promising treatment for OA and can be applied to other stem cell therapies or regenerative medical treatments.


Assuntos
Células-Tronco Mesenquimais , Osteoartrite , Ratos , Humanos , Animais , Cálcio/efeitos adversos , Alginatos/efeitos adversos , Osteoartrite/induzido quimicamente , Osteoartrite/terapia , Osteoartrite/patologia , Adipócitos/patologia , Modelos Animais de Doenças
6.
Radiat Prot Dosimetry ; 199(4): 325-336, 2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36588461

RESUMO

The Oak Ridge National Laboratory (ORNL) phantoms based on data of Caucasians have been widely used for fetal dosimetry. However, there are differences in body size during pregnancy among Taiwanese and Caucasians. In this study, the uterine dose conversion coefficients (DCCs) of Taiwanese pregnant women were evaluated to facilitate the use of it to estimate the possible uterine dose (usually regarded as fetal dose) of pregnant Taiwanese women during radiation practice or medical exposures. The uterine DCCs in this study were calculated based on the established Taiwanese pregnancy voxel phantoms, and were compared with the uterine DCCs of the International Commission on Radiological Protection. The applicability of evaluating uterine DCCs with different phantoms was also discussed. Results showed that if the ORNL phantoms are used to evaluate the uterine dose of Taiwanese pregnant women, the uterine dose may be underestimated. This study provides the uterine DCCs assessed with the Taiwanese pregnancy phantoms for future dose assessment of Taiwanese.


Assuntos
Gestantes , Proteção Radiológica , Humanos , Feminino , Gravidez , Fótons , Método de Monte Carlo , Radiometria/métodos , Proteção Radiológica/métodos , Imagens de Fantasmas , Doses de Radiação
7.
Mater Today Bio ; 15: 100266, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35517579

RESUMO

Several studies have focused on using cell carriers to solve the problem of mesenchymal stem cell expansion on regenerative medicine. However, the disadvantages of using prolonged enzymatic treatment and low cell harvest efficiency still trouble researchers. In this study, PNIPAAm-immobilized gelatin microspheres (abbreviated as GNMS) were synthesized using a simple power-driven flow-focusing microinjection system. The developed thermosensitive GNMS can allow easier harvesting of cells from the microspheres, requiring only 10 â€‹min of low-temperature treatment and 5 â€‹min of trypsin treatment. The developed GNMS was characterized by Fourier-transform infrared spectroscopy, optical microscopy, and scanning electron microscopy. Further, live/dead staining, F-actin staining, and PrestoBlue cell viability assays were used to evaluate cytotoxicity, cell morphology, cell proliferation, and harvest efficiency. The gene expression of stem cell markers was determined by real-time quantitative PCR (Q-PCR) analysis to investigate the stemness and phenotypic changes in Wharton's jelly-derived mesenchymal stem cells. The results showed that the engineered cell-laden thermosensitive GNMS could significantly increase the cell harvest rate with over 99% cell survival rate and no change in the cell phenotype. Thus, the described strategy GNMS could be the suitable 3D cell carriers in the therapeutic application and opens new avenues for regenerative medicine.

8.
J Chemother ; 34(1): 55-66, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34286671

RESUMO

The miRNA-302 family plays a critical role in carcinogenesis. As an enzyme that regulates the N6-methyladenosine modification, methyltransferase-like 3 (METTL3) plays important roles in the development and progression of various tumours. However, the upstream regulatory mechanisms of METTL3 in melanoma have not yet been fully investigated. Herein, we investigated the functions of miR-302a-3p and its target RNA METTL3 on proliferation, apoptosis, and invasion of melanoma. Quantitative real-time PCR and immunofluorescence staining were used to measure the expression of METTL3 mRNA and protein level after transfection. miR-302a-3p expression was determined by quantitative reverse transcription-PCR. The cell proliferation, cell cycle progression, apoptosis, colony formation, migration, and cell invasion ability were determined using MTT assay, propidium iodide (PI) staining, Annexin V/PI flow cytometry, plate clone assay, and Transwell migration and invasion assays, respectively. Melanoma cell metastasis was also evaluated using an in vivo model. The effect of METTL3 on the phosphorylation of PI3K and AKT was measured with western blot analysis. Our results showed that miR-302a-3p was significantly downregulated in melanoma and exerted a tumour suppressive role against melanoma progression. We identified METTL3 as a direct target of miR-302a-3p in melanoma cells using bioinformatics analysis and luciferase assay. Furthermore, the enforced overexpression of METTL3 promoted the proliferation, cell cycle progression, cell invasion, migration, expression of epithelial-to-mesenchymal transition markers, and the PI3K-AKT signalling pathway as well as suppressed the apoptosis of melanoma cells. Meanwhile, silencing the expression of METTL3 with specific shRNA demonstrated reverse outcomes of the above phenotypes in melanoma cells. By rescue experiments, we found that the restoration of METTL3 expression in miR-302a-3p-overexpressing melanoma cells successfully recovered the miR-302a-3p-mediated melanoma suppression. The in vivo results also showed that miR-302a-3p substantially inhibited melanoma cell growth and metastasis. In summary, this study demonstrated that miR-302a-3p targets METTL3 and plays tumour suppressive roles in the proliferation, apoptosis, invasion, and migration of melanoma cells.


Assuntos
Melanoma/patologia , Metiltransferases/efeitos dos fármacos , MicroRNAs/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Camundongos , Camundongos Nus , Fosfatidilinositol 3-Quinase/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , RNA Mensageiro , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Front Bioeng Biotechnol ; 9: 765630, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34869278

RESUMO

Body sculpture is a common method to remove excessive fat. The diet and exercise are the first suggestion to keep body shape; however, those are difficult to keep adherence. Ultrasound has been developed for fat ablation; however, it could only serve as the side treatment along with liposuction. In the study, a sonosensitizer of europium-doped calcium carbonate (CaCO3: Eu) would be synthesized by an eco-method and combined with low-intensity ultrasound for lipolysis. The crystal structure of CaCO3: Eu was identified by x-ray diffractometer (XRD). The morphology of CaCO3: Eu was analyzed by scanning electron microscope (SEM). The chemical composition of CaCO3: Eu was evaluated by energy-dispersed spectrophotometer (EDS) and inductively coupled plasma mass spectrometer (ICP-MS). The electronic diffraction pattern was to further check crystal structure of the synthesized individual grain by transmission electron microscope (TEM). The particle size was determined by Zeta-sizer. Water-soluble tetrazolium salt (WST-1) were used to evaluate the cell viability. Chloromethyl-2',7'-dichlorofluorescein diacetate (CM-H2DCFDA) and live/dead stain were used to evaluate feasibility in vitro. SD-rat was used to evaluate the safety and efficacy in vivo. The results showed that CaCO3: Eu had good biocompatibility and could produce reactive oxygen species (ROS) after treated with low-intensity ultrasound. After 4-weeks, the CaCO3: Eu exposed to ultrasound irradiation on SD rats could significantly decrease body weight, waistline, and subcutaneous adipose tissue. We believe that ROS from sonoluminescence, CO2-bomb and locally increasing Ca2+ level would be three major mechanisms to remove away adipo-tissue and inhibit adipogenesis. We could say that the combination of the CaCO3: Eu and low-intensity ultrasound would be a non-invasive treatment for the body sculpture.

10.
Micromachines (Basel) ; 12(3)2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33809131

RESUMO

A magnetic field measurement system based on an array of Hall sensors is proposed. The sensors are fabricated using conventional microelectromechanical systems (MEMS) techniques and consist of a P-type silicon substrate, a silicon dioxide isolation layer, a phosphide-doped cross-shaped detection zone, and gold signal leads. When placed within a magnetic field, the interaction between the local magnetic field produced by the working current and the external magnetic field generates a measurable Hall voltage from which the strength of the external magnetic field is then derived. Four Hall sensors are fabricated incorporating cross-shaped detection zones with an identical aspect ratio (2.625) but different sizes (S, M, L, and XL). For a given working current, the sensitivities and response times of the four devices are found to be almost the same. However, the offset voltage increases with the increasing size of the detection zone. A 3 × 3 array of sensors is assembled into a 3D-printed frame and used to determine the magnetic field distributions of a single magnet and a group of three magnets, respectively. The results show that the constructed 2D magnetic field contour maps accurately reproduce both the locations of the individual magnets and the distributions of the magnetic fields around them.

11.
Bioresour Technol ; 319: 124145, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32979598

RESUMO

To explore the catalytic effect of potassium on pyrolysis characteristics of biomass, the rubberwood is pyrolyzed by a thermogravimetric analyzer. The samples are impregnated by three concentrations of potassium carbonate (0.004 M, 0.008 M, and 0.012 M). The pyrolysis kinetics is analyzed by an independent parallel reaction (IPR) model to describe the catalytic effect on the four-pseudo components model in the rubberwood. The particle swarm optimization (PSO) is adopted to optimize the fit quality between the established kinetic models and experimental data. It is found that the pyrolysis of rubberwood impregnated with 0.012 M concentration of K2CO3 can reduce the activation energy of cellulose from 223.86 to 204.14 kJ mol-1, whereas there is no obvious effect on the activation energies of hemicelluloses and lignin. The starting temperature and ending temperature of cellulose thermodegradation also move toward lower temperatures, indicating that the addition of potassium enhances the degradation of cellulose.


Assuntos
Lignina , Pirólise , Biomassa , Cinética , Potássio , Termogravimetria
12.
Omega (Westport) ; 83(4): 777-801, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31387461

RESUMO

This qualitative study examined the language of women who were child sexual abuse survivors (N = 16) to gain insight into their grief experiences following the death of their abusers. Participants ranged in age from 22 to 62 years (M = 47.4) and the majority were White, had been abused by a family member, and had sought child sexual abuse-related counseling. Five primary themes emerged during analysis: (a) grief reflecting a complex relationship; (b) loss of opportunity for confrontation, clarity, and connection; (c) funeral as liability, not benefit; (d) others' lack of understanding of multilayered grief; and (e) coping through transformation. Discussion illuminates sense-making and connections between themes and existing thanatological concepts and research.


Assuntos
Abuso Sexual na Infância , Adulto , Criança , Feminino , Pesar , Humanos , Pessoa de Meia-Idade , Pesquisa Qualitativa , Inquéritos e Questionários , Sobreviventes , Adulto Jovem
14.
J Econ Entomol ; 113(6): 2986-2996, 2020 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-33128452

RESUMO

The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera, Noctuidae), is a polyphagous and highly destructive agricultural pest that invaded mainland China in 2019. To facilitate research on this pest, it is important to formulate and formalize a suitable artificial diet based on local ingredients. In this study, the life histories of fall armyworm reared on corn leaves and four artificial diets were recorded. The four artificial diets used were: soybean and sucrose-based (SS), soybean and wheat germ-based (SW), chickpea and wheat germ-based (CPW), and corn and soybean-based (CNS). The intrinsic rates of increase were 0.1957, 0.1981, 0.1816, 0.1748, and 0.1464 per day in the fall armyworm populations fed corn leaves, CNS, SW, CPW, and SS, respectively. The highest fecundity (F = 1225.4 eggs per female) and net reproduction rate (R0 = 544.7 offspring per individual) were observed for the fall armyworm reared on the CNS diet. Moreover, the developmental rate, survival rate, and fecundity were used to calculate the projection of the population growth. Projection results showed that the fall armyworm populations can increase considerably faster when fed the CNS diet compared with the other diets. In addition, the mass-rearing system showed that the most efficient and economical strategy would be to rear the fall armyworm on the CNS diet. The results indicated that the CNS diet was the most suitable diet for the fall armyworm mass rearing.


Assuntos
Grão Comestível , Mariposas , Animais , China , Dieta , Feminino , Spodoptera , Zea mays
15.
Antioxidants (Basel) ; 9(9)2020 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-32957611

RESUMO

Sonodynamic therapy is an effective treatment for eliminating tumor cells by irradiating sonosentitizer in a patient's body with higher penetration ultrasound and inducing the free radicals. Titanium dioxide has attracted the most attention due to its properties among many nanosensitizers. Hence, in this study, carbon doped titanium dioxide, one of inorganic materials, is applied to avoid the foregoing, and furthermore, carbon doped titanium dioxide is used to generate ROS under ultrasound irradiation to eliminate tumor cells. Spherical carbon doped titanium dioxide nanoparticles are synthesized by the sol-gel process. The forming of C-Ti-O bond may also induce defects in lattice which would be beneficial for the phenomenon of sonoluminescence to improve the effectiveness of sonodynamic therapy. By dint of DCFDA, WST-1, LDH and the Live/Dead test, carbon doped titanium dioxide nanoparticles are shown to be a biocompatible material which may induce ROS radicals to suppress the proliferation of 4T1 breast cancer cells under ultrasound treatment. From in vivo study, carbon doped titanium dioxide nanoparticles activated by ultrasound may inhibit the growth of the 4T1 tumor, and it showed a significant difference between sonodynamic therapy (SDT) and the other groups on the seventh day of the treatment.

16.
Bioresour Technol ; 301: 122774, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31954973

RESUMO

The thermal characteristics of Actinobacillus succinogenes (AS) from pyrolysis, torrefaction, and combustion are analyzed to evaluate the potential of this biomass as a renewable fuel. AS pyrolysis can be classified into four stages, and its main decomposition zone is at 200-500 °C. The solid yield of AS after 60 min torrefaction is over 60 wt%, and the torrefaction severity index map indicates that a high torrefaction temperature with a short duration has a more profound influence on its decomposition. The Py-GC/MS analysis of AS suggests that the volatile products from 500 °C pyrolysis are similar to microalgae-derived pyrolysis bio-oils. The combustibility index (S) of AS is 4.07 × 10-7 which is much higher than that of lignite coal (0.39 × 10-7) and bituminous coal (0.18 × 10-7), and close to those of biochar and bio-oil. The obtained results are conducive to the development of microorganisms as fuel to achieve a circular bioeconomy.


Assuntos
Actinobacillus , Microalgas , Biomassa , Temperatura Alta
18.
Eur J Radiol ; 117: 9-14, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31307658

RESUMO

OBJECTIVE: The purpose of this study was to investigate the impact of the new American College of Radiology (ACR) digital mammography (DM) phantom in evaluating phantom image quality (IQ) and average glandular dose (AGD) in a nationwide survey on DM systems. METHODS: On-site surveys of 239 DM units were conducted in 2017 and 2018, and comparisons were made between ACR screen-film mammography (SFM) phantom and DM phantom for accessing phantom IQ and AGD. The phantom IQ was assessed using the weighted phantom score, considering the size of each detail. RESULTS: When switching from SFM phantom to DM phantom, no significant difference was found in AGD (p = 0.06). The mean weighted phantom score was significantly higher for DM phantom than for SFM phantom in terms of fibers and specks, and so was the total weighted phantom score (DM phantom vs. SFM phantom: 8.61 ± 1.04 vs. 8.23 ± 0.77, p < 0.0001). The phantom IQ is thus more precise and can detect small differences when using DM phantom and investigating DM systems, especially for specks and fibers. However, the overall passing rate was lower for DM phantom (84.1%) than for SFM phantom (91.2%). This can be explained by the lower passing rate for mass (84.5%) with the DM phantom. CONCLUSION: The ACR DM phantom provides better discernment to assess specks and fibers in DM systems. This study may serve as a reference for implementing a DM quality control program and when conducting large-scale surveys with the new DM phantom in the digital era.


Assuntos
Mama/efeitos da radiação , Mamografia , Intensificação de Imagem Radiográfica , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Mamografia/instrumentação , Variações Dependentes do Observador , Imagens de Fantasmas , Doses de Radiação , Intensificação de Imagem Radiográfica/instrumentação , Intensificação de Imagem Radiográfica/métodos , Padrões de Referência , Taiwan
19.
Eur J Radiol ; 108: 99-106, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30396678

RESUMO

OBJECTIVE: This study investigated the influence of spatial overlap and radiographic length (RL) on the effective dose (ED) and organ dose for pediatric patients undergoing whole spine radiography using an auto-stitching digital radiography (DR) system. METHODS: First, the system parameters were tested on a 10-year-old pediatric anthropomorphic phantom with a Shimadzu DR system, and the effects of the spatial overlap and RL on radiation doses were validated. The ED and organ dose were calculated on the basis of a Monte Carlo simulation program. Subsequently, 82 patients with adolescent idiopathic scoliosis were recruited. The spatial overlap and RL for each patient were modified to further investigate the dose reduction feasibility. RESULTS: RL and ED were appropriately correlated on the basis of patients' height. For a patient measuring 158 cm, the Shimadzu DR system was equipped with a 17-inch detector with a cut-off RL of 75 cm. The phantom simulations indicated that ED was reduced to a minimum value of 0.188 ± 0.001 mSv with a high RL for RL < 75 cm. The minimum value increased to 0.300 ± 0.002 mSv for an RL of 75 cm and dropped to 0.222 ± 0.001 mSv for the maximum RL. By employing optimized RLs for patients, EDs were significantly reduced (p < 0.05). Moreover, ED reductions were higher when longer RLs were employed. CONCLUSION: A decrease in the spatial overlap and number of radiographic acquisitions by adjusting RLs when possible could reduce ED and almost all organ doses. This study emphasized the effects of RL on the radiation dose and provided useful guidance for modifying the RL for patients to reduce the whole spine radiography dose using a modern auto-stitching DR system.


Assuntos
Escoliose/diagnóstico por imagem , Coluna Vertebral/efeitos da radiação , Adolescente , Criança , Feminino , Humanos , Masculino , Método de Monte Carlo , Imagens de Fantasmas , Estudos Prospectivos , Doses de Radiação , Intensificação de Imagem Radiográfica , Radiografia/métodos , Coluna Vertebral/diagnóstico por imagem
20.
BMC Med Imaging ; 18(1): 2, 2018 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-29402236

RESUMO

BACKGROUND: To investigate the organ dose, effective dose (ED), conversion factor, and the C-arm rotation angle effects on dose variations of abdominal C-arm cone-beam computed tomography (CBCT) during transarterial chemoembolization (TACE). METHODS: The organ doses and EDs for abdominal C-arm CBCT were retrospectively calculated according to a Monte Carlo technique for 80 patients. Dose variations from projections, ED to dose-area product (DAP) ratios, and effects of body mass index (BMI) on the ED and ED to DAP ratios were also analyzed. RESULTS: The kidney received the highest dose (14.6 ± 1.2 mSv). Organ dose deviations among C-arm rotation angles was highest for stomach (CV = 0.71). The mean ED of the the CBCT run during TACE was 3.5 ± 0.5 mSv, and decreased with increased BMI (R2 = 0.45, p < 0.001). The mean ED to DAP ratio was 0.27 ± 0.04 mSv·Gy- 1·cm- 2 and tended to decrease with increased BMI (R2 = 0.55, p < 0.001). The mean ED to DAP ratios were 0.29 ± 0.02, 0.26 ± 0.02, and 0.23 ± 0.03 mSv·Gy- 1·cm- 2 for patients with BMI < 25 kg/m2, 25-30 kg/m2, and ≥30 kg/m2, respectively. CONCLUSIONS: Suitable conversion factors for C-arm CBCT facilitate the use of DAPs for estimating the ED. The patient dose can be varied by adjusting the CBCT rotation angle setting, and dose reduction strategies can be further manipulated.


Assuntos
Abdome/diagnóstico por imagem , Quimioembolização Terapêutica/métodos , Tomografia Computadorizada de Feixe Cônico/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Feminino , Humanos , Rim/diagnóstico por imagem , Rim/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Método de Monte Carlo , Imagens de Fantasmas , Estudos Retrospectivos
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