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Microscopy techniques using visible photons, x-rays, neutrons, and electrons have made remarkable impact in many scientific disciplines. The microscopic data can often be expressed as the convolution of the spatial distribution of certain properties of the specimens and the inherent response function of the imaging system. The x-ray grating interferometer (XGI), which is sensitive to the deviation angle of the incoming x-rays, has attracted significant attention in the past years due to its capability in achieving x-ray phase contrast imaging with low brilliance source. However, the comprehensive and analytical theoretical framework is yet to be presented. Herein, we propose a theoretical framework termed angular signal radiography (ASR) to describe the imaging process of the XGI system in a classical, comprehensive and analytical manner. We demonstrated, by means of theoretical deduction and synchrotron based experiments, that the spatial distribution of specimens' physical properties, including absorption, refraction and scattering, can be extracted by ASR in XGI. Implementation of ASR in XGI offers advantages such as simplified phase retrieval algorithm, reduced overall radiation dose, and improved image acquisition speed. These advantages, as well as the limitations of the proposed method, are systematically investigated in this paper.
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A description of the rocking curve in diffraction enhanced imaging (DEI) is presented in terms of the angular signal response function and a simple multi-information retrieval algorithm based on the cosine function fitting. A comprehensive analysis of noise properties of DEI is also given considering the noise transfer characteristic of the X-ray source. The validation has been performed with synchrotron radiation experimental data and Monte Carlo simulations based on the Geant4 toolkit combined with the refractive process of X-rays, which show good agreement with each other. Moreover, results indicate that the signal-to-noise ratios of the refraction and scattering images are about one order of magnitude better than that of the absorption image at the edges of low-Z samples. The noise penalty is drastically reduced with the increasing photon flux and visibility. Finally, this work demonstrates that the analytical method can build an interesting connection between DEI and GDPCI (grating-based differential phase contrast imaging) and is widely suitable for a variety of measurement noise in the angular signal response imaging prototype. The analysis significantly contributes to the understanding of noise characteristics of DEI images and may allow improvements to the signal-to-noise ratio in biomedical and material science imaging.
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BACKGROUND: In patients with advanced cancer receiving immune checkpoint inhibitors (ICIs) therapy, there are conflict perspectives about the influence of concomitant use of proton pump inhibitors (PPIs). We are aimed at exploring the influence of concomitant PPIs exposure on clinical outcome among cancer patients receiving ICIs treatment. METHODS: We searched relevant literatures in PubMed, EMBASE, and the Cochrane Library without language restrictions. We extracted the data from selected studies and calculated the pooled hazard ratios (HRs) with 95% CIs through professional software for overall survival and progression-free survival among cancer patients undergoing ICIs therapy exposed to PPIs. RESULTS: Fourteen studies including 6716 advanced cancer patients receiving ICIs treatment were appropriate for analysis judging by pre-set inclusion and exclusion criteria. The result indicated that concomitant PPIs exposure was significantly related to shorter overall survival (HR=1.388; 95% CI: 1.278-1.498, P <0.001) and progression-free survival (HR=1.285; 95% CI: 1.193-1.384, P <0.001) among multiple cancer patients receiving ICIs therapy. CONCLUSIONS: Our meta-analysis showed that concomitant PPIs exposure had an adverse impact on clinical outcome among patients receiving ICIs therapy. Clinical oncologists must be cautious of PPIs delivery during ICIs treatment.
Assuntos
Inibidores de Checkpoint Imunológico , Neoplasias , Humanos , Inibidores de Checkpoint Imunológico/uso terapêutico , Inibidores da Bomba de Prótons/uso terapêutico , Pessoal de Saúde , Neoplasias/tratamento farmacológico , Intervalo Livre de ProgressãoRESUMO
Hepatitis B virus reactivation (HBV-R), which can lead to HBV-related morbidity and mortality, is a common and well-known complication that occurs during the treatment of non-Hodgkin lymphoma (NHL) patients with current or past exposure to HBV infection. HBV-R is thought to be closely associated with chemotherapeutic or immunosuppressive therapies. However, immunosuppressive agents such as anti-CD20 antibodies (e.g., rituximab and ofatumumab), glucocorticoids, and hematopoietic stem cell transplantation (HSCT) administered to NHL patients during treatment can cause deep immunodepression and place them at high risk of HBV-R. In this review, we explore the current evidence, the guidelines of several national and international organizations, and the recommendations of expert panels relating to the definition, risk factors, screening and monitoring strategies, whether to use prophylaxis or pre-emptive therapy, and the optimal antiviral agent and duration of antiviral therapy for HBV-R.
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To predict potential medical value or toxicity of nanoparticles (NPs), it is necessary to understand the chemical transformation during intracellular processes of NPs. However, it is a grand challenge to capture a high-resolution image of metallic NPs in a single cell and the chemical information on intracellular NPs. Here, by integrating synchrotron radiation-beam transmission X-ray microscopy (SR-TXM) and SR-X-ray absorption near edge structure (SR-XANES) spectroscopy, we successfully capture the 3D distribution of silver NPs (AgNPs) inside a single human monocyte (THP-1), associated with the chemical transformation of silver. The results reveal that the cytotoxicity of AgNPs is largely due to the chemical transformation of particulate silver from elemental silver (Ag(0))n, to Ag(+) ions and Ag-O-, then Ag-S- species. These results provide direct evidence in the long-lasting debate on whether the nanoscale or the ionic form dominates the cytotoxicity of silver nanoparticles. Further, the present approach provides an integrated strategy capable of exploring the chemical origins of cytotoxicity in metallic nanoparticles.