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1.
Radiology ; 312(1): e240273, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38980179

RESUMO

Background The diagnostic abilities of multimodal large language models (LLMs) using direct image inputs and the impact of the temperature parameter of LLMs remain unexplored. Purpose To investigate the ability of GPT-4V and Gemini Pro Vision in generating differential diagnoses at different temperatures compared with radiologists using Radiology Diagnosis Please cases. Materials and Methods This retrospective study included Diagnosis Please cases published from January 2008 to October 2023. Input images included original images and captures of the textual patient history and figure legends (without imaging findings) from PDF files of each case. The LLMs were tasked with providing three differential diagnoses, repeated five times at temperatures 0, 0.5, and 1. Eight subspecialty-trained radiologists solved cases. An experienced radiologist compared generated and final diagnoses, considering the result correct if the generated diagnoses included the final diagnosis after five repetitions. Accuracy was assessed across models, temperatures, and radiology subspecialties, with statistical significance set at P < .007 after Bonferroni correction for multiple comparisons across the LLMs at the three temperatures and with radiologists. Results A total of 190 cases were included in neuroradiology (n = 53), multisystem (n = 27), gastrointestinal (n = 25), genitourinary (n = 23), musculoskeletal (n = 17), chest (n = 16), cardiovascular (n = 12), pediatric (n = 12), and breast (n = 5) subspecialties. Overall accuracy improved with increasing temperature settings (0, 0.5, 1) for both GPT-4V (41% [78 of 190 cases], 45% [86 of 190 cases], 49% [93 of 190 cases], respectively) and Gemini Pro Vision (29% [55 of 190 cases], 36% [69 of 190 cases], 39% [74 of 190 cases], respectively), although there was no evidence of a statistically significant difference after Bonferroni adjustment (GPT-4V, P = .12; Gemini Pro Vision, P = .04). The overall accuracy of radiologists (61% [115 of 190 cases]) was higher than that of Gemini Pro Vision at temperature 1 (T1) (P < .001), while no statistically significant difference was observed between radiologists and GPT-4V at T1 after Bonferroni adjustment (P = .02). Radiologists (range, 45%-88%) outperformed the LLMs at T1 (range, 24%-75%) in most subspecialties. Conclusion Using direct radiologic image inputs, GPT-4V and Gemini Pro Vision showed improved diagnostic accuracy with increasing temperature settings. Although GPT-4V slightly underperformed compared with radiologists, it nonetheless demonstrated promising potential as a supportive tool in diagnostic decision-making. © RSNA, 2024 See also the editorial by Nishino and Ballard in this issue.


Assuntos
Radiologistas , Humanos , Estudos Retrospectivos , Diagnóstico Diferencial , Interpretação de Imagem Assistida por Computador/métodos , Feminino
2.
Psychol Sci ; 32(9): 1452-1462, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34410853

RESUMO

Despite the pervasiveness of facial inferences, scholars have debated whether our face reflects valid information regarding how we actually behave. Whereas previous research has largely focused on the accuracy of facial inferences, the present research examined the validity of face-based judgments. Specifically, we tested how accurate face-based judgments are, whether the accuracy of and confidence in face-based judgments are associated, and what mechanisms potentially link facial appearance to behaviors (N = 1,386 American and Korean adults). We found that although face-based judgments could accurately predict someone's behavior (Study 1), participants' confidence about their face-based judgments was not associated with their accuracy (Studies 2a and 2b). Moreover, Study 3 demonstrated that the accuracy of facial inferences is possibly due to self-fulfilling effects of facial inferences. That is, accuracy is largely driven by perceivers' beliefs rather than by the direct association between faces and behaviors.


Assuntos
Face , Julgamento , Adulto , Humanos , Percepção Social
3.
Int J Hyperthermia ; 37(1): 1287-1292, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33198552

RESUMO

PURPOSE: To evaluate whether the additive needle tract ablation (TA) can reduce adherent cells on the needle tract after radiofrequency ablation (RFA) in a preclinical HCC mouse model. METHODS: Hep3B-Luc cells were engrafted in the Balb/c-nude mice. Nineteen mice were randomly assigned into three groups: the needle only group (needle placement only without performing RFA), the RFA only group (needle placement with active RFA treatment), and the RFA-TA group (needle placement with active RFA treatment and additive tract ablation). The 17-gauge needle with a 10-mm active tip was used. After RFA and TA, the viability of adherent tumor cells on the RFA needle was evaluated with bioluminescence imaging (BLI) and live-cell counting. RESULTS: We observed that RFA-TA group had the lowest BLI values compared with other groups (needle only group, 11.2 ± 6.4 million; RFA only group, 13.6 ± 9.1 million; RFA-TA group, 1.11 ± 0.8 million, p = 0.001). Live cell counting with acridine orange/propidium iodide staining also confirmed that the counted viable cell numbers in RFA-TA group were lowest compared to the other groups (needle only group, 14.8 ± 4.5; RFA only group, 643.8 ± 131.9; RFA-TA group, 1.5 ± 0.9, p < 0.001). CONCLUSIONS: The additive tract ablation can significantly reduce the number of viable tumor cells adherent to the RFA needle, which can prevent needle tract seeding after RFA procedure.


Assuntos
Carcinoma Hepatocelular , Ablação por Cateter , Neoplasias Hepáticas , Ablação por Radiofrequência , Animais , Carcinoma Hepatocelular/cirurgia , Adesão Celular , Eletrodos , Neoplasias Hepáticas/cirurgia , Camundongos , Camundongos Nus
4.
J Nanosci Nanotechnol ; 19(8): 4651-4656, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30913763

RESUMO

We suggest a facile method to reduce the surface roughness of the ferroelectric polymer insulator to enhance the electrical performance of the ferroelectric field effect memory transistors (FeFET). Ferroelectric-dielectric mixed buffer layer was used to reduce the high surface roughness of the single layer ferroelectric polymer insulator. The FeFET with mixed buffer bilayer (BL-FeFET) showed more than 25 times higher on-current (3.40 µA) compared with single layer FeFET (130 nA). The BL-FeFET showed enhanced memory retention, higher memory on-off ratio than the conventional single layer FeFET (SL-FeFET). The enhancement of the electrical performance of the BL-FeFET can be attributed to the smoothening of the rough needle-like grain surface morphology of the ferroelectric polymer insulator in the SL-FeFET. This process of mixed buffer polymer insulator may provide a technological method for production of high-performance nonvolatile FeFET memory devices.

5.
BMC Med Imaging ; 19(1): 89, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31729971

RESUMO

BACKGROUND: To facilitate translational drug development for liver fibrosis, preclinical trials need to be run in parallel with clinical research. Liver function estimation by gadoxetate-enhanced dynamic contrast-enhanced MRI (DCE-MRI) is being established in clinical research, but still rarely used in preclinical trials. We aimed to evaluate feasibility of DCE-MRI indices as translatable biomarkers in a liver fibrosis animal model. METHODS: Liver fibrosis was induced in Sprague-Dawley rats by thioacetamide (200 mg, 150 mg, and saline for the high-dose, low-dose, and control groups, respectively). Subsequently, DCE-MRI was performed to measure: relative liver enhancement at 3-min (RLE-3), RLE-15, initial area-under-the-curve until 3-min (iAUC-3), iAUC-15, and maximum-enhancement (Emax). The correlation coefficients between these MRI indices and the histologic collagen area, indocyanine green retention at 15-min (ICG-R15), and shear wave elastography (SWE) were calculated. Diagnostic performance to diagnose liver fibrosis was also evaluated by receiver-operating-characteristic (ROC) analysis. RESULTS: Animal model was successful in that the collagen area of the liver was the largest in the high-dose group, followed by the low-dose group and control group. The correlation between the DCE-MRI indices and collagen area was high for iAUC-15, Emax, iAUC-3, and RLE-3 but moderate for RLE-15 (r, - 0.81, - 0.81, - 0.78, - 0.80, and - 0.51, respectively). The DCE-MRI indices showed moderate correlation with ICG-R15: the highest for iAUC-15, followed by iAUC-3, RLE-3, Emax, and RLE-15 (r, - 0.65, - 0.63, - 0.62, - 0.58, and - 0.56, respectively). The correlation coefficients between DCE-MRI indices and SWE ranged from - 0.59 to - 0.28. The diagnostic accuracy of RLE-3, iAUC-3, iAUC-15, and Emax was 100% (AUROC 1.000), whereas those of RLE-15 and SWE were relatively low (AUROC 0.777, 0.848, respectively). CONCLUSION: Among the gadoxetate-enhanced DCE-MRI indices, iAUC-15 and iAUC-3 might be bidirectional translatable biomarkers between preclinical and clinical research for evaluating histopathologic liver fibrosis and physiologic liver functions in a non-invasive manner.


Assuntos
Meios de Contraste/administração & dosagem , Gadolínio DTPA/administração & dosagem , Cirrose Hepática/diagnóstico por imagem , Fígado/fisiopatologia , Animais , Área Sob a Curva , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Estudos de Viabilidade , Humanos , Fígado/diagnóstico por imagem , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/fisiopatologia , Testes de Função Hepática , Imageamento por Ressonância Magnética , Masculino , Ratos , Ratos Sprague-Dawley , Tioacetamida/efeitos adversos
6.
Sensors (Basel) ; 19(19)2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31623381

RESUMO

Rapid industrialization has significantly influenced people's lifestyles in the recent decades, and the influence of traditional culture is diminishing. Recently, several studies attempted to simultaneously utilize various sensors to record delicate and sophisticated performances of intangible cultural heritage (ICH). Although painting is one of the most common ICH of human history, few research studies have recorded traditional painting work. In this paper, we aim to lay the groundwork for reviving Korean painting, even if there would be no painters to produce these traditional Korean paintings in the future. We propose a novel multisensor-based acquisition system that records traditional Korean painting work while minimizing interference in the work. The proposed system captures real-time data originating from the painter, brushes, pigments, and canvas, which are the essential components of the painting work. We utilized the proposed system to capture the painting work by two experts, and we visualize the captured data. We showed the various results of statistical analysis, and also discussed the usability.

7.
Asian-Australas J Anim Sci ; 31(5): 763-772, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29268574

RESUMO

OBJECTIVE: Swine manure in Korea is separated into solid and liquid phases which are composted separately and then applied on land. The nutrient accumulation in soil has been a big issue in Korea but the basic investigation about nutrient input on arable land has not been achieved in detail. Within the nutrient production from livestock at the national level, most values are calculated by multiplication of the number of animals with the excreta unit per animal. However, the actual amount of nutrients from swine manure may be totally different with the nutrients applied to soil since livestock breeding systems are not the same with each country. METHODS: This study investigated 15 farms producing solid compost and 14 farms producing liquid compost. Composting for solid phase used the Turning+Aeration (TA) or Turning (T) only methods, while liquid phase aeration composting was achieved by continuous (CA), intermittent (IA), or no aeration (NA). Three scenarios were constructed for investigating solid compost: i) farm investigation, ii) reference study, and iii) theoretical P changes (ΔP = 0), whereas an experiment for water evaporation was conducted for analyzing liquid compost. RESULTS: In farm investigation, weight loss rates of 62% and 63% were obtained for TA and T, respectively, while evaporation rates for liquid compost were 8.75, 7.27, and 5.14 L/m2·d for CA, IA, and NA, respectively. Farm investigation provided with the combined nutrient load (solid+liquid) of VS, N, and P of 117.6, 7.2, and 2.7 kg/head·yr. Nutrient load calculated from farm investigation is about two times higher than the calculated with reference documents. CONCLUSION: The nutrient loading coefficients from one swine (solid+liquid) were (volatile solids, 0.79; nitrogen, 0.53; phosphorus, 0.71) with nutrient loss of 21%, 47%, and 29%, respectively. The nutrient count from livestock manure using the excretion unit has probably been overestimated without consideration of the nutrient loss.

8.
Asian-Australas J Anim Sci ; 30(1): 125-132, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27492346

RESUMO

OBJECTIVE: Along with increasing livestock products via intensive rearing, the accumulation of livestock manure has become a serious issue due to the fact that there is finite land for livestock manure recycling via composting. The nutrients from livestock manure accumulate on agricultural land and the excess disembogues into streams causing eutrophication. In order to systematically manage nutrient loading on agricultural land, quantifying the amount of nutrients according to their respective sources is very important. However, there is a lack of research concerning nutrient loss from livestock manure during composting or storage on farms. Therefore, in the present study we quantified the nutrients from dairy cattle manure that were imparted onto agricultural land. METHODS: Through investigation of 41 dairy farms, weight reduction and volatile solids (VS), total nitrogen (TN), and total phosphorus (TP) changes of dairy cattle manure during the storage and composting periods were analyzed. In order to support the direct investigation and survey on site, the three cases of weight reduction during the storing and composting periods were developed according to i) experiment, ii) reference, and iii) theoretical changes in phosphorus content (ΔP = 0). RESULTS: The data revealed the nutrient loading coefficients (NLCs) of VS, TN, and TP on agricultural land were 1.48, 0.60, and 0.66, respectively. These values indicated that the loss of nitrogen and phosphorus was 40% and 34%, respectively, and that there was an increase of VS since bedding materials were mixed with excretion in the barn. CONCLUSION: As result of nutrient-footprint analyses, the amounts of TN and TP particularly entered on arable land have been overestimated if applying the nutrient amount in fresh manure. The NLCs obtained in this study may assist in the development of a database to assess the accurate level of manure nutrient loading on soil and facilitate systematic nutrient management.

9.
J Magn Reson Imaging ; 44(2): 251-64, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-26854494

RESUMO

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a promising tool for evaluating tumor vascularity, as it can provide vasculature-derived, functional, and quantitative parameters. To implement DCE-MRI parameters as biomarkers for monitoring the effect of antiangiogenic or vascular-disrupting treatment, two crucial elements of surrogate endpoint, ie, validation and qualification, should be satisfied. Although early studies have shown the accuracy and reliability of DCE-MRI parameters for evaluating treatment-driven vascular alterations, there have been an increasing number of studies demonstrating the limitations of DCE-MRI parameters as surrogate endpoints. Therefore, in order to improve the application of DCE-MRI parameters in drug development, it is necessary to establish a standardized evaluation method and to determine the correct therapeutics-oriented meaning of individual DCE-MRI parameter. In this regard, this article describes the biophysical background and data acquisition/analysis techniques of DCE-MRI while focusing on the validation and qualification issues. Specifically, the causes of disagreement and confusion encountered in the preclinical and clinical trials using DCE-MRI are presented in detail. Finally, considering these limitations, we present potential strategies to optimize implementation of DCE-MRI. J. Magn. Reson. Imaging 2016;44:251-264.


Assuntos
Meios de Contraste , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Neovascularização Patológica/diagnóstico por imagem , Neovascularização Patológica/tratamento farmacológico , Animais , Antineoplásicos/uso terapêutico , Descoberta de Drogas/métodos , Avaliação Pré-Clínica de Medicamentos/métodos , Monitoramento de Medicamentos/métodos , Humanos , Neoplasias/patologia , Neovascularização Patológica/patologia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
10.
J Neurooncol ; 128(2): 185-94, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27108275

RESUMO

This study aims to evaluate the value of perfusion MRI as a predictive/prognostic biomarker and a pharmacodynamic biomarker in patients with recurrent glioma treated with a bevacizumab-based regimen. We identified thirteen literature reports that investigated dynamic susceptibility-contrast (DSC) MRI or dynamic contrast-enhanced (DCE) MRI for predicting the patient outcome and analyzing the anti-angiogenic effect of bevacizumab by performing a systematic search of MEDLINE and EMBASE. The relative cerebral volume (rCBV) of DSC-MRI is currently the most common perfusion MRI parameter used as a predictive/prognostic biomarker. Pooled hazard ratios between responders and non-responders, as determined by rCBV, were 0.46 (95 % CI 0.28-0.76) for progression-free survival from five articles with a total 226 patients and 0.47 (95 % CI 0.29-0.76) for overall survival from six articles with a total 247 patients, and thus indicating that rCBV is helpful for predicting disease progression and the eventual outcome after treatment. Regarding the pharmacodynamic value of perfusion MRI parameters derived from either DSC-MRI or DCE-MRI, most perfusion MRI parameters (rCBV, Ktrans, CBVmax, Kpsmax, fpv, Ve and Kep) demonstrated a consistent decrease on the follow-up MRI after treatment, indicating that perfusion MRI may be helpful for evaluating the anti-angiogenic effect of a bevacizumab-based treatment regimen. However, the lack of standardization of imaging acquisition and analysis techniques for various perfusion MRI parameters needs to be resolved in the future. Despite these unsolved issues, the current evidence favoring the use of perfusion MRI as a predictive/prognostic or pharmacodynamic biomarker should be considered in patients with glioma treated using a bevacizumab-based regimen.


Assuntos
Bevacizumab/uso terapêutico , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/tratamento farmacológico , Glioma/diagnóstico por imagem , Glioma/tratamento farmacológico , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagem , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Neoplasias Encefálicas/metabolismo , Meios de Contraste , Glioma/metabolismo , Humanos , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/metabolismo , Prognóstico
11.
Eur Radiol ; 26(11): 3949-3956, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26809293

RESUMO

OBJECTIVES: To evaluate the feasibility of test-bolus dynamic contrast-enhanced (DCE) MRI with CAIPIRINHA-VIBE for pancreatic malignancies. METHODS: Thirty-two patients underwent DCE-MRI with CAIPIRINHA-VIBE after injection of 2 mL gadolinium. From the resulting time-intensity curve (TIC), we estimated the arterial (AP) and portal venous phase (PVP) scan timing for subsequent multiphasic MRI. DCE-MRI perfusion maps were generated, and perfusion parameters were calculated. The image quality was rated on a 5-point scale (1: poor, 5: excellent). Goodness-of-fit of the TIC was evaluated by Pearson's χ2 test. RESULTS: Test-bolus DCE-MRIs with high temporal (3 s) and spatial resolution (1 × 1 × 4 mm3) were acquired with good-quality perfusion maps of Ktrans and iAUC (mean score 4.313 ± 0.535 and 4.125 ± 0.554, respectively). The mean χ2 values for fitted TICs were 0.115 ± 0.082 for the pancreatic parenchyma and 0.784 ± 0.074 for pancreatic malignancies, indicating an acceptable goodness-of-fit. Test-bolus DCE-MRI was highly accurate in estimating the proper timing of AP (90.6 %) and PVP (100 %) of subsequent multiphasic MRI. Between pancreatic adenocarcinomas and neuroendocrine tumours, there were significant differences in the Ktrans (0.073 ± 0.058 vs. 0.308 ± 0.062, respectively; p = 0.007) and iAUC (1.501 ± 0.828 vs. 3.378 ± 0.378, respectively; p = 0.045). CONCLUSIONS: Test-bolus DCE-MRI using CAIPIRINHA-VIBE is feasible for incorporating perfusion analysis of pancreatic tumours into routine multiphasic MRI. KEY POINTS: • Test-bolus DCE-MRI using CAIPIRINHA-VIBE is feasible for perfusion analysis of pancreatic tumours. • CAIPIRINHA-VIBE enables DCE-MRI with high temporal and spatial resolution. • Test-bolus DCE-MRI is highly accurate in estimating the proper timing of multiphasic MRI.


Assuntos
Imageamento por Ressonância Magnética/métodos , Neoplasias Pancreáticas/diagnóstico por imagem , Adulto , Idoso , Meios de Contraste , Estudos de Viabilidade , Feminino , Gadolínio , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Radioisótopos
12.
NMR Biomed ; 28(2): 168-79, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25448225

RESUMO

Molecular imaging can be a breakthrough tool for the investigation of the behavior and ultimate feasibility of transplanted human mesenchymal stem cells (hMSCs) inside the body, and for the development of guidelines and recommendations based on the treatment and evaluation of stem cell therapy for patients. The goals of this study were to evaluate the multilineage differentiation ability of hMSCs expressing an MRI reporter, human ferritin heavy chain (FTH) and to investigate the feasibility of using FTH-based MRI to provide noninvasive imaging of transplanted hMSCs. The transduction of FTH and green fluorescence protein (GFP) did not influence the expression of the mesenchymal stem cell surface markers (CD29+/CD105+/CD34-/CD45-) or the self-renewal marker genes [octamer-binding transcription factor 4 (OCT-4) and SRY (sex determining region Y)-box 2 (Sox-2)], cell viability, migration ability and the release of cytokines [interleukin-5 (IL-5), IL-10, IL-12p70, tumor necrosis factor-α (TNF-α)]. FTH-hMSCs retained the capacity to differentiate into adipogenic, chondrogenic, osteogenic and neurogenic lineages. The transduction of FTH led to a significant enhancement in cellular iron storage capacity and caused hypointensity and a significant increase in R2 * values of FTH-hMSC-collected phantoms and FTH-hMSC-transplanted sites of the brain, as shown by in vitro and in vivo MRI performed at 9.4 T, compared with control hMSCs. This study revealed no differences in biological characteristics between hMSCs and FTH-hMSCs and, therefore, these cells could be used for noninvasive monitoring with MRI during stem cell therapy for brain injury. Our study suggests the use of FTH for in vivo long-term tracking and ultimate fate of hMSCs without alteration of their characteristics and multidifferentiation potential.


Assuntos
Diferenciação Celular , Linhagem da Célula , Ferritinas/metabolismo , Imageamento por Ressonância Magnética/métodos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Transdução Genética , Animais , Biomarcadores/metabolismo , Encéfalo/metabolismo , Genes Reporter , Proteínas de Fluorescência Verde/metabolismo , Humanos , Ferro/metabolismo , Masculino , Transplante de Células-Tronco Mesenquimais , Camundongos Endogâmicos BALB C , Camundongos Nus , Neurônios/citologia , Imagens de Fantasmas
13.
Proc Natl Acad Sci U S A ; 108(7): 2662-7, 2011 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-21282616

RESUMO

For ultrasensitive magnetic resonance imaging (MRI), magnetic nanoparticles with extremely high r2 relaxivity are strongly desired. Magnetosome-like nanoparticles were prepared by coating polyethylene glycol-phospholipid (PEG-phospholipid) onto ferrimagnetic iron oxide nanocubes (FIONs). FIONs exhibited a very high relaxivity (r2) of 324 mM(-1) s(-1), allowing efficient labeling of various kinds of cells. The magnetic resonance (MR) imaging of single cells labeled with FIONs is demonstrated not only in vitro but also in vivo. Pancreatic islet grafts and their rejection could be imaged using FIONs on a 1.5 T clinical MRI scanner. The strong contrast effect of FIONs enabled MR imaging of transplanted islets in small rodents as well as in large animals. Therefore, we expect that MR imaging of pancreatic islet grafts using FIONs has the potentials for clinical applications. Furthermore, FIONs will enable highly sensitive noninvasive assessment after cell transplantation.


Assuntos
Transplante das Ilhotas Pancreáticas/patologia , Ilhotas Pancreáticas/ultraestrutura , Imageamento por Ressonância Magnética/métodos , Nanopartículas de Magnetita/química , Monitorização Fisiológica/métodos , Polietilenoglicóis/química , Compostos Férricos/química , Fosfolipídeos/química , Coloração e Rotulagem/métodos
14.
Int J Biol Macromol ; : 134013, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39032883

RESUMO

Lipase with unique regioselectivity is an attractive biocatalyst for elaborate lipid modification. However, the excavation of novel sn-2 regioselective lipases is difficult due to their scarcity in nature, with Candida antarctica lipase A (CALA) being the pronouncedly reported one. Here, we identified a novel CALA-like lipase from Cordyceps militaris (CACML7) via in silico mining. Through chiral-phase high-performance liquid chromatography, we determined that CACML7 displays sn-2 regioselectivity (>68 %) as does CALA, but exhibits distinctive chain length selectivity and bias against unsaturated fats. Notably, the curvature of the acyl-binding tunnel was expected to contribute to the 2.2-fold higher preference for cis-fatty acid (C18:1, cis-Δ9) over trans-fatty acid (C18:1, trans-Δ9) unlike trans-active CALA. Random pose docking of trioleoylglycerol (TOG) into the active site of a lid-truncated mutant of CACML7 revealed that TOG accepts a tuning fork conformation, of which the precise positioning of the reactive ester group towards the catalytic center was only favorable via sn-2 binding mode. The unique active site morphology, which we refer to as an "acyl-binding tunnel with a narrow entrance," may contribute to the sn-2 regioselectivity of CACML7. Our data provide an attractive model to better understand the mechanism underlying sn-2 regioselectivity.

15.
Adv Mater ; 36(25): e2307286, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38516842

RESUMO

Solid oxide fuel cells that operate at intermediate temperatures require efficient catalysts to enhance the inherently poor electrochemical activity of the composite electrodes. Here, a simple and practical electrochemical deposition method is presented for fabricating a PrOx overlayer on lanthanum strontium manganite-yttria-stabilized zirconia (LSM-YSZ) composite electrodes. The method requires less than four minutes for completion and can be carried out under at ambient temperature and pressure. Crucially, the treatment significantly improves the electrode's performance without requiring heat treatment or other supplementary processes. The PrOx-coated LSM-YSZ electrode exhibits an 89% decrease in polarization resistance at 650 °C (compared to an untreated electrode), maintaining a tenfold reduction after ≈400 h. Transmission line model analysis using impedance spectra confirms how PrOx coating improved the oxygen reduction reaction activity. Further, tests with anode-supported single cells reveal an outstanding peak power density compared to those of other LSM-YSZ-based cathodes (e.g., 418 mW cm-2 at 650 °C). Furthermore, it is demonstrated that multicomponent coating, such as (Pr,Ce)Ox, can also be obtained with this method. Overall, the observations offer a promising route for the development of high-performance solid oxide fuel cells.

16.
Psychol Aging ; 39(1): 1-13, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37883011

RESUMO

Happiness can be experienced differently in young as compared to older adulthood, possibly due to shifts in temporal focus and differences in preferences for high- versus low-arousal affective states. The current project aimed to replicate initial evidence on age-related differences in the experience of happiness by investigating the positive affective correlates of everyday happiness; we further explored the role of thinking about the future in moderating such associations. We used daily life assessments from 257 participants (Mage = 48.3, SDage = 24.6; 68% female; 77% Asian [East Asian, South Asian, and Southeast Asian]; 73% postsecondary educated), combining four data sets collected at two locations (Vancouver, Canada; Hong Kong) with different age samples (older and younger adults). Participants provided up to 30 repeated daily life assessments of momentary affective states and thoughts about the future, over 10 days. Results replicate previous findings by showing that happiness was more strongly associated with low-arousal positive affect and more weakly associated with high-arousal positive affect among older compared to younger adults. Engagement in thinking about the future was higher among younger compared to older adults in general, but its role in moderating the association between happiness and positive affect varying in arousal levels was confounded by the age moderation. Separate analyses conducted for each age group indicate different roles of everyday thinking about the future in shaping happiness experiences for different age groups. Age and future thinking-related contours of happiness are discussed in the context of emotional aging theories. (PsycInfo Database Record (c) 2024 APA, all rights reserved).


Assuntos
Envelhecimento , Felicidade , Idoso , Feminino , Humanos , Masculino , Envelhecimento/psicologia , Nível de Alerta , Povo Asiático , Emoções , Afeto
17.
Appl Psychol Health Well Being ; 16(1): 356-375, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37740540

RESUMO

Older adults spend significant time by themselves, especially since COVID-19. Solitude has been associated with positive and negative outcomes. Partners need to balance social connectedness with time for one's own needs. This project examines how individual and partner solitude are associated with daily affect and relationship quality in dyads of older adults and a close other. One-hundred thirty-six older adults plus a close other rated their relationship quality and reported affect, solitude, and its characteristics (desired and bothersome) every evening for 10 days. Over and above overall associations, individual and partner effects emerged; when individual desired solitude was up, participants reported more positive affect and their partners less negative affect. When bothersome solitude was up, participants and their partners alike reported more negative affect and less positive affect. Desired solitude was associated with more support, whereas bothersome solitude was associated with less partner support. Findings provide further evidence on the potential benefits of solitude, highlighting the importance of considering the social context of what is often believed to be an individual-level phenomenon.


Assuntos
Bem-Estar Psicológico , Meio Social , Idoso , Humanos , Relações Interpessoais
18.
Mol Imaging Biol ; 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38684581

RESUMO

PURPOSE: Gadolinium (Gd)-based contrast agents are primarily used for contrast-enhanced magnetic resonance lymphangiography (MRL). However, overcoming venous contamination issues remains challenging. This study aims to assess the MRL efficacy of the newly developed iron-based contrast agent (INV-001) that is specially designed to mitigate venous contamination issues. The study further explores the optimal dosage, including both injection volume and concentration, required to achieve successful visualization of the popliteal lymph nodes and surrounding lymphatic vessels. PROCEDURES: All animals utilized in this study were male Sprague-Dawley (SD) rats weighing between 250 and 300 g. The contrast agents prepared were injected intradermally in the fourth phalanx of both hind limbs using a 30-gauge syringe in SD rats. MRL was performed every 16 min on a coronal 3D time-of-flight sequence with saturation bands using a 9.4-T animal machine. RESULTS: Contrary to Gd-DOTA, which exhibited venous contamination in most animals irrespective of injection dosages and conditions, INV-001 showed no venous contamination. For Gd-DOTA, the popliteal lymph nodes and lymphatic vessels reached peak enhancement 16 min after injection from the injection site and then rapidly washed out. However, with INV-001, they reached peak enhancement between 16 and 32 min after injection, with prolonged visualization of the popliteal lymph node and lymphatic vessels. INV-001 at 0.45 µmol (15 mM, 30 µL) and 0.75 µmol (15 mM, 50 µL) achieved high scores for qualitative image analysis, providing good visualization of the popliteal lymph nodes and lymphatic vessels without issues of venous contamination, interstitial space enhancement, or lymph node enlargement. CONCLUSION: In MRL, INV-001, a novel T1 contrast agent based on iron, enables prolonged enhancement of popliteal lymph nodes and lymphatic vessels without venous contamination.

19.
Invest New Drugs ; 31(5): 1097-106, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23299389

RESUMO

Vascular disrupting agents (VDAs) are new class of anti-cancer drugs targeting pre-existing tumor vasculature which lead to tumor ischemia and necrosis. An innovative tubulin polymerization inhibitor, CKD-516, was recently developed as a VDA. We attempted to evaluate its tubulin destabilizing effect using immunofluorescence staining on human endothelial cells (HUVECs) and to ascertain its antivascular effect in a rabbit VX2 tumor model using dynamic contrast-enhanced (DCE) MRI by measuring the changes in kinetic parameters such as K-trans and IAUGC. Immunofluorescence staining using anti-tubulin and anti-actin antibodies on HUVECs showed that CKD-516 selectively disrupted tubulin component of the endothelial cytoskeleton. Serial DCE-MRI showed a significant decrease in K-trans and IAUGC parameters from baseline at 4 h (39.9 % in K-trans; -45.0 % in IAUGC) and at 24 h (-32.2 % in K-trans; -36.5 % in IAUGC), and a significant recovery at 48 h (22.9 % in K-trans; 34.8 % in IAUGC) following administration of CKD-516 at a 0.7-mg/kg dose. When the tumors were stratified according to the initial K-trans value of 0.1, tumors with a high K-trans > 0.1 which was indicative of having well-developed pre-existing vessels, showed greater reduction in K-trans and IAUGC values. On histologic examination, the degree of necrosis of treated tumors was significantly greater than that of untreated tumors. In summary, CKD-516 is an effective VDA which results in rapid vascular shutdown by targeting the tubulin component of tumor vessels and thus leads to necrosis.


Assuntos
Antineoplásicos/uso terapêutico , Benzofenonas/uso terapêutico , Neoplasias de Tecido Muscular/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Moduladores de Tubulina/uso terapêutico , Valina/análogos & derivados , Animais , Antineoplásicos/farmacologia , Benzofenonas/farmacologia , Células Cultivadas , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Imageamento por Ressonância Magnética/métodos , Neoplasias de Tecido Muscular/irrigação sanguínea , Neoplasias de Tecido Muscular/metabolismo , Neoplasias de Tecido Muscular/patologia , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Coelhos , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/farmacologia , Valina/farmacologia , Valina/uso terapêutico
20.
Nano Lett ; 12(6): 3127-31, 2012 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-22575047

RESUMO

The theoretically predicted maximum r(2) relaxivity of iron oxide nanoparticles was achieved by optimizing the overall size of ferrimagnetic iron oxide nanocubes. Uniform-sized iron oxide nanocubes with an edge length of 22 nm, encapsulated with PEG-phospholipids (WFION), exhibited high colloidal stability in aqueous media. In addition, WFIONs are biocompatible and did not affect cell viability at concentrations up to 0.75 mg Fe/ml. Owing to the enhanced colloidal stability and the high r(2) relaxivity (761 mM(-1) s(-1)), it was possible to successfully perform in vivo MR imaging of tumors by intravenous injection of 22-nm-sized WFIONs, using a clinical 3-T MR scanner.


Assuntos
Compostos Férricos , Imageamento por Ressonância Magnética/métodos , Nanopartículas de Magnetita , Neoplasias Experimentais/patologia , Água/química , Linhagem Celular Tumoral , Meios de Contraste , Difusão , Humanos
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