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1.
J Endourol ; 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38717951

RESUMO

Purpose The increasing incidence of nephrolithiasis underscores the need for effective, accessible tools to aid urologists in preventing recurrence. Despite dietary modification's crucial role in prevention, targeted dietary counseling using 24-hour urine collections is underutilized. This study evaluates ChatGPT-4, a multimodal large language model, in analyzing urine collection results and providing custom dietary advice, exploring the potential for artificial intelligence-assisted analysis and counseling. Materials and Methods Eleven unique prompts with synthesized 24-hour urine collection results were submitted to ChatGPT-4. The model was instructed to provide five dietary recommendations in response to the results. One prompt contained all "normal" values, with subsequent prompts introducing one abnormality each. Generated responses were assessed for accuracy, completeness, and appropriateness by two urologists, a nephrologist, and a clinical dietitian. Results ChatGPT-4 achieved average scores of 5.2/6 for accuracy, 2.4/3 for completeness, and 2.6/3 for appropriateness. It correctly identified all "normal" values but had difficulty consistently detecting abnormalities and formulating appropriate recommendations. The model performed particularly poorly in response to calcium and citrate abnormalities and failed to address 3/10 abnormalities entirely. Conclusions While ChatGPT-4 shows potential in aiding the dietary management of nephrolithiasis, its current limitations in identifying and addressing abnormal urine values suggests that it is not ready for clinical application. The model's ability to generate accurate and comprehensive advice under normal conditions contrasts sharply with its inadequacy in contexts of abnormalities like those seen among stone-formers. This juxtaposition highlights the need for significant improvement through further training and rigorous validation. If and when ChatGPT is used in clinical settings, it will require precise prompt design and meticulous monitoring by physicians. Despite the hurdles, the model's strengths indicate that, with advances, it could eventually make a valuable contribution to patient care and the efficiency of clinical practices.

2.
Nat Commun ; 10(1): 5289, 2019 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-31754109

RESUMO

Resonant X-ray absorption, where an X-ray photon excites a core electron into an unoccupied valence state, is an essential process in many standard X-ray spectroscopies. With increasing X-ray intensity, the X-ray absorption strength is expected to become nonlinear. Here, we report the onset of such a nonlinearity in the resonant X-ray absorption of magnetic Co/Pd multilayers near the Co L[Formula: see text] edge. The nonlinearity is directly observed through the change of the absorption spectrum, which is modified in less than 40 fs within 2 eV of its threshold. This is interpreted as a redistribution of valence electrons near the Fermi level. For our magnetic sample this also involves mixing of majority and minority spins, due to sample demagnetization. Our findings reveal that nonlinear X-ray responses of materials may already occur at relatively low intensities, where the macroscopic sample is not destroyed, providing insight into ultrafast charge and spin dynamics.

3.
Biol Trace Elem Res ; 191(2): 370-381, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30635848

RESUMO

The negative health impact of zinc deficiency overlaps significantly with arsenic exposure, and is associated with increased risk for chronic diseases. Arsenic contamination in the groundwater often co-exists in regions of the world that are prone to zinc deficiency. Notably, low zinc status shares many hallmarks of arsenic exposure, including increased oxidative stress and inflammation. Despite their common targets and frequent co-distribution in the population, little is known regarding the interaction between zinc deficiency and arsenic exposure. In this study, we tested the effect of arsenic exposure at environmentally relevant doses in combination with a physiologically relevant level of zinc deficiency (marginal zinc deficiency) on zinc status, oxidative damage, and inflammation. In cell culture, zinc-deficient THP-1 monocytes co-exposed with arsenic resulted in further reduction in intracellular zinc, as well as further increase in oxidative stress and inflammatory markers. In an animal study, zinc-deficient mice had further decrease in zinc status when co-exposed to arsenic. Zinc deficiency, but not arsenic exposure, resulted in an increase in baseline transcript abundance of inflammatory markers in the liver. Upon lipopolysaccharide challenge to elicit an acute inflammatory response, arsenic exposure, but not zinc deficiency, resulted in an increase in proinflammatory response. In summary, zinc deficiency and arsenic exposure can function independently or cooperatively to affect zinc status, oxidant stress, and proinflammatory response. The results highlight the need to consider both nutritional status and arsenic exposures together when considering their impact on health outcomes in susceptible populations.


Assuntos
Arsênio/toxicidade , Inflamação/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Zinco/metabolismo , Animais , Quimiocina CCL2/metabolismo , Feminino , Citometria de Fluxo , Humanos , Interleucina-8/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Células THP-1 , Zinco/deficiência
4.
PLoS One ; 12(8): e0183831, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28837703

RESUMO

Zinc deficiency and chronic low level exposures to inorganic arsenic in drinking water are both significant public health concerns that affect millions of people including pregnant women. These two conditions can co-exist in the human population but little is known about their interaction, and in particular, whether zinc deficiency sensitizes individuals to arsenic exposure and toxicity, especially during critical windows of development. To address this, we utilized the Danio rerio (zebrafish) model to test the hypothesis that parental zinc deficiency sensitizes the developing embryo to low-concentration arsenic toxicity, leading to altered developmental outcomes. Adult zebrafish were fed defined zinc deficient and zinc adequate diets and were spawned resulting in zinc adequate and zinc deficient embryos. The embryos were treated with environmentally relevant concentrations of 0, 50, and 500 ppb arsenic. Arsenic exposure significantly reduced the amount of zinc in the developing embryo by ~7%. The combination of zinc deficiency and low-level arsenic exposures did not sensitize the developing embryo to increased developmental malformations or mortality. The combination did cause a 40% decline in physical activity of the embryos, and this decline was significantly greater than what was observed with zinc deficiency or arsenic exposure alone. Significant changes in RNA expression of genes that regulate zinc homeostasis, response to oxidative stress and insulin production (including zip1, znt7, nrf2, ogg1, pax4, and insa) were found in zinc deficient, or zinc deficiency and arsenic exposed embryos. Overall, the data suggests that the combination of zinc deficiency and arsenic exposure has harmful effects on the developing embryo and may increase the risk for developing chronic diseases like diabetes.


Assuntos
Arsênio/toxicidade , Peixe-Zebra/embriologia , Zinco/deficiência , Animais , Relação Dose-Resposta a Droga , Desenvolvimento Embrionário/efeitos dos fármacos , Desenvolvimento Embrionário/genética , Regulação da Expressão Gênica no Desenvolvimento , Homeostase , Insulina/biossíntese , Estresse Fisiológico , Peixe-Zebra/genética
5.
Nano Lett ; 17(4): 2426-2432, 2017 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-28272897

RESUMO

Light-matter interaction at the nanoscale in magnetic materials is a topic of intense research in view of potential applications in next-generation high-density magnetic recording. Laser-assisted switching provides a pathway for overcoming the material constraints of high-anisotropy and high-packing density media, though much about the dynamics of the switching process remains unexplored. We use ultrafast small-angle X-ray scattering at an X-ray free-electron laser to probe the magnetic switching dynamics of FePt nanoparticles embedded in a carbon matrix following excitation by an optical femtosecond laser pulse. We observe that the combination of laser excitation and applied static magnetic field, 1 order of magnitude smaller than the coercive field, can overcome the magnetic anisotropy barrier between "up" and "down" magnetization, enabling magnetization switching. This magnetic switching is found to be inhomogeneous throughout the material with some individual FePt nanoparticles neither switching nor demagnetizing. The origin of this behavior is identified as the near-field modification of the incident laser radiation around FePt nanoparticles. The fraction of not-switching nanoparticles is influenced by the heat flow between FePt and a heat-sink layer.

6.
Nano Lett ; 15(10): 6889-95, 2015 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-26322659

RESUMO

Two-dimensional materials are subject to intrinsic and dynamic rippling that modulates their optoelectronic and electromechanical properties. Here, we directly visualize the dynamics of these processes within monolayer transition metal dichalcogenide MoS2 using femtosecond electron scattering techniques as a real-time probe with atomic-scale resolution. We show that optical excitation induces large-amplitude in-plane displacements and ultrafast wrinkling of the monolayer on nanometer length-scales, developing on picosecond time-scales. These deformations are associated with several percent peak strains that are fully reversible over tens of millions of cycles. Direct measurements of electron-phonon coupling times and the subsequent interfacial thermal heat flow between the monolayer and substrate are also obtained. These measurements, coupled with first-principles modeling, provide a new understanding of the dynamic structural processes that underlie the functionality of two-dimensional materials and open up new opportunities for ultrafast strain engineering using all-optical methods.

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