High-energy gamma-ray radiography has exceptional penetration ability and has become an indispensable nondestructive testing(NDT)tool in various fields.For high-energy photons,point projection radiography is almost th...High-energy gamma-ray radiography has exceptional penetration ability and has become an indispensable nondestructive testing(NDT)tool in various fields.For high-energy photons,point projection radiography is almost the only feasible imaging method,and its spatial resolution is primarily constrained by the size of the gamma-ray source.In conventional industrial applications,gamma-ray sources are commonly based on electron beams driven by accelerators,utilizing the process of bremsstrahlung radiation.The size of the gamma-ray source is dependent on the dimensional characteristics of the electron beam.Extensive research has been conducted on various advanced accelerator technologies that have the potential to greatly improve spatial resolution in NDT.In our investigation of laser-driven gamma-ray sources,a spatial resolution of about 90μm is achieved when the areal density of the penetrated object is 120 g/cm^(2).A virtual source approach is proposed to optimize the size of the gamma-ray source used for imaging,with the aim of maximizing spatial resolution.In this virtual source approach,the gamma ray can be considered as being emitted from a virtual source within the convertor,where the equivalent gamma-ray source size in imaging is much smaller than the actual emission area.On the basis of Monte Carlo simulations,we derive a set of evaluation formulas for virtual source scale and gamma-ray emission angle.Under optimal conditions,the virtual source size can be as small as 15μm,which can significantly improve the spatial resolution of high-penetration imaging to less than 50μm.展开更多
Lung cancer is a highly heterogeneous malignancy with a complex pathogenesis, involving a series of endogenous alterations such as genetic mutations, epigenetic modifications, and oxidative stress. Recent advancements...Lung cancer is a highly heterogeneous malignancy with a complex pathogenesis, involving a series of endogenous alterations such as genetic mutations, epigenetic modifications, and oxidative stress. Recent advancements in lung cancer research, especially at the genomic and molecular biology levels, have continuously provided new potential targets and perspectives for the diagnosis and treatment of lung cancer. Therefore, this article summarizes the recent progress in the study of endogenous factors related to the pathogenesis of lung cancer, aiming to enhance the understanding of intrinsic factors in lung cancer and to organize ideas for subsequent related research.展开更多
Forward radiative transfer(RT)models are essential for atmospheric applications such as remote sensing and weather and climate models,where computational efficiency becomes equally as important as accuracy for high-re...Forward radiative transfer(RT)models are essential for atmospheric applications such as remote sensing and weather and climate models,where computational efficiency becomes equally as important as accuracy for high-resolution hyperspectral measurements that need rigorous RT simulations for thousands of channels.This study introduces a fast and accurate RT model for the hyperspectral infrared(HIR)sounder based on principal component analysis(PCA)or machine learning(i.e.,neural network,NN).The Geosynchronous Interferometric Infrared Sounder(GIIRS),the first HIR sounder onboard the geostationary Fengyun-4 satellites,is considered to be a candidate example for model development and validation.Our method uses either PCA or NN(PCA/NN)twice for the atmospheric transmittance and radiance,respectively,to reduce the number of independent but similar simulations to accelerate RT simulations;thereby,it is referred to as a multi-domain compression model.The first PCA/NN gives monochromatic gas transmittance in both spectral and atmospheric pressure domains for each gas independently.The second PCA/NN is performed in the traditional spectral radiance domain.Meanwhile,a new method is introduced to choose representative variables for the PCA/NN scheme developments.The model is three orders of magnitude faster than the standard line-by-line-based simulations with averaged brightness temperature difference(BTD)less than 0.1 K,and the compressions based on PCA or NN methods result in comparable efficiency and accuracy.Our fast model not only avoids an excessively complicated transmittance scheme by using PCA/NN but is also highly flexible for hyperspectral instruments with similar spectral ranges simply by updating the corresponding spectral response functions.展开更多
Tissue engineering chambers (TECs) represent a new and attractive in vivo tissue engineering model that can successfully generate mature adipose tissue. However, the newly formed adipose tissue is not able to fill the...Tissue engineering chambers (TECs) represent a new and attractive in vivo tissue engineering model that can successfully generate mature adipose tissue. However, the newly formed adipose tissue is not able to fill the volume of the chamber as expected. To investigate whether the capsule surrounding the newly formed adipose tissue limits the adipose tissue volume in the chamber, we detected fibrotic parameters two months after these chambers were implanted into rats. The results showed that the newly formed adipose tissue was surrounded by a thick layer of capsule, and the protein levels of transforming growth factor-<em>β</em>1 (TGF-<em>β</em>1), phosphorylated Smad2 (p-Smad2), connective tissue growth factor (CTGF), collagen type I (COL-I) and α-smooth muscle actin (<em>α</em>-SMA) in the capsule were increased. The levels of these proteins decreased following systemic administration of P144 (a peptide inhibitor of TGF-<em>β</em>1). Furthermore, the capsule thickness was significantly reduced, and the adipose tissue volume was markedly greater when using P144. These findings indicate that capsule formation, which is mediated through a TGF-<em>β</em>1 signaling pathway, restricted the volume of the engineered adipose tissue that was formed. This study may provide a new approach to regenerate amounts of adipose tissue for the reconstruction of large soft tissue defects.展开更多
<b>Objectives:</b> Allogeneic myoblast transplantation (AMT), cyclosporine immunosuppression and coronary artery bypass grafting (CABG) were used to treat end-stage heart failure (HF) subjects without hope...<b>Objectives:</b> Allogeneic myoblast transplantation (AMT), cyclosporine immunosuppression and coronary artery bypass grafting (CABG) were used to treat end-stage heart failure (HF) subjects without hope of obtaining a heart transplant. <b>Background:</b> Severe myocardial infarction conveys serious complications such as ventricular aneurysm, wall thinning and rupture with fatal consequences. <b>Methods: </b>After meeting Inclusion/Exclusion criteria and signing Patient Informed Consents, 10 HF subjects having mean thinnest wall thickness of 2.21 ± 0.55 mm and ventricular aneurysms were admitted under intensive care. Each subject took daily cyclosporine for three weeks. On the third day of cyclosporine administration, approximately 1 billion myoblasts were implanted <span>through 20 injections into the infarcted myocardium following CABG. <b>Results: </b><u>Safety</u> No subject suffered death, viral infection, malignant arrhythmia, reduction in cardiac output, immune rejection, or aneurysm growth. No significant difference was found before versus after treatment in the mean levels of blood routine, liver and kidney enzymes, electrolytes and fibrinogen. <u>Efficacy</u> Emission computed tomography (ECT) and magnetic resonance (MR) demonstrated significant increases in viability and perfusion. Mean left ventricular ejection fraction (LVEF) significantly increased (P < 0.05) by 20.1% and 19.3% at 6 months and at 2 years postoperatively. New York Heart Association (NYHA) class improved by 2 grades, including 6-minute walk test (6 MWT) distance increase, and reductions in the number of episodes of angina pectoris, chest tightness, shortness of breath after exercise, and nighttime sit-up breathing. <b>Conclusions: </b>For the first time, AMT in adjunct use with CABG and cyclosporine demonstrated that cell survived and engrafted in patients with ischemic cardiomyopathy;in this small study the cell transplant was safe. The improvement in heart function and quality of life could be secondary to combined effect of bypass and cell transplant. A larger randomized clinical trial is required to confirm the efficacy.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.12175212,11991071,12004353,11975214,and 11905202)the National Key R&D Program of China(Grant No.2022YFA1603300)+1 种基金the Science Challenge Project(Project No.TZ2018005)the Sciences and Technology on Plasma Physics Laboratory at CAEP(Grant No.6142A04200103).
文摘High-energy gamma-ray radiography has exceptional penetration ability and has become an indispensable nondestructive testing(NDT)tool in various fields.For high-energy photons,point projection radiography is almost the only feasible imaging method,and its spatial resolution is primarily constrained by the size of the gamma-ray source.In conventional industrial applications,gamma-ray sources are commonly based on electron beams driven by accelerators,utilizing the process of bremsstrahlung radiation.The size of the gamma-ray source is dependent on the dimensional characteristics of the electron beam.Extensive research has been conducted on various advanced accelerator technologies that have the potential to greatly improve spatial resolution in NDT.In our investigation of laser-driven gamma-ray sources,a spatial resolution of about 90μm is achieved when the areal density of the penetrated object is 120 g/cm^(2).A virtual source approach is proposed to optimize the size of the gamma-ray source used for imaging,with the aim of maximizing spatial resolution.In this virtual source approach,the gamma ray can be considered as being emitted from a virtual source within the convertor,where the equivalent gamma-ray source size in imaging is much smaller than the actual emission area.On the basis of Monte Carlo simulations,we derive a set of evaluation formulas for virtual source scale and gamma-ray emission angle.Under optimal conditions,the virtual source size can be as small as 15μm,which can significantly improve the spatial resolution of high-penetration imaging to less than 50μm.
文摘Lung cancer is a highly heterogeneous malignancy with a complex pathogenesis, involving a series of endogenous alterations such as genetic mutations, epigenetic modifications, and oxidative stress. Recent advancements in lung cancer research, especially at the genomic and molecular biology levels, have continuously provided new potential targets and perspectives for the diagnosis and treatment of lung cancer. Therefore, this article summarizes the recent progress in the study of endogenous factors related to the pathogenesis of lung cancer, aiming to enhance the understanding of intrinsic factors in lung cancer and to organize ideas for subsequent related research.
基金supported by the National Natural Science Foundation of China(Grant No.42122038)。
文摘Forward radiative transfer(RT)models are essential for atmospheric applications such as remote sensing and weather and climate models,where computational efficiency becomes equally as important as accuracy for high-resolution hyperspectral measurements that need rigorous RT simulations for thousands of channels.This study introduces a fast and accurate RT model for the hyperspectral infrared(HIR)sounder based on principal component analysis(PCA)or machine learning(i.e.,neural network,NN).The Geosynchronous Interferometric Infrared Sounder(GIIRS),the first HIR sounder onboard the geostationary Fengyun-4 satellites,is considered to be a candidate example for model development and validation.Our method uses either PCA or NN(PCA/NN)twice for the atmospheric transmittance and radiance,respectively,to reduce the number of independent but similar simulations to accelerate RT simulations;thereby,it is referred to as a multi-domain compression model.The first PCA/NN gives monochromatic gas transmittance in both spectral and atmospheric pressure domains for each gas independently.The second PCA/NN is performed in the traditional spectral radiance domain.Meanwhile,a new method is introduced to choose representative variables for the PCA/NN scheme developments.The model is three orders of magnitude faster than the standard line-by-line-based simulations with averaged brightness temperature difference(BTD)less than 0.1 K,and the compressions based on PCA or NN methods result in comparable efficiency and accuracy.Our fast model not only avoids an excessively complicated transmittance scheme by using PCA/NN but is also highly flexible for hyperspectral instruments with similar spectral ranges simply by updating the corresponding spectral response functions.
文摘Tissue engineering chambers (TECs) represent a new and attractive in vivo tissue engineering model that can successfully generate mature adipose tissue. However, the newly formed adipose tissue is not able to fill the volume of the chamber as expected. To investigate whether the capsule surrounding the newly formed adipose tissue limits the adipose tissue volume in the chamber, we detected fibrotic parameters two months after these chambers were implanted into rats. The results showed that the newly formed adipose tissue was surrounded by a thick layer of capsule, and the protein levels of transforming growth factor-<em>β</em>1 (TGF-<em>β</em>1), phosphorylated Smad2 (p-Smad2), connective tissue growth factor (CTGF), collagen type I (COL-I) and α-smooth muscle actin (<em>α</em>-SMA) in the capsule were increased. The levels of these proteins decreased following systemic administration of P144 (a peptide inhibitor of TGF-<em>β</em>1). Furthermore, the capsule thickness was significantly reduced, and the adipose tissue volume was markedly greater when using P144. These findings indicate that capsule formation, which is mediated through a TGF-<em>β</em>1 signaling pathway, restricted the volume of the engineered adipose tissue that was formed. This study may provide a new approach to regenerate amounts of adipose tissue for the reconstruction of large soft tissue defects.
基金supported by the National Natural Science Foundation of China(Nos.52171073,51801031,51775117)the Foshan Science and Technology Innovation Project,China(No.2018IT100112)+1 种基金the Research Fund of Key Laboratory of High Performance Manufacturing for Aero Engine(Northwestern Polytechnical University),Ministry of Industry and Information Technology,China(No.HPM-2020-06)the Fund of the State Key Laboratory of Solidification Processing in Northwestern Polytechnical University,China(No.SKLSP202014).
文摘<b>Objectives:</b> Allogeneic myoblast transplantation (AMT), cyclosporine immunosuppression and coronary artery bypass grafting (CABG) were used to treat end-stage heart failure (HF) subjects without hope of obtaining a heart transplant. <b>Background:</b> Severe myocardial infarction conveys serious complications such as ventricular aneurysm, wall thinning and rupture with fatal consequences. <b>Methods: </b>After meeting Inclusion/Exclusion criteria and signing Patient Informed Consents, 10 HF subjects having mean thinnest wall thickness of 2.21 ± 0.55 mm and ventricular aneurysms were admitted under intensive care. Each subject took daily cyclosporine for three weeks. On the third day of cyclosporine administration, approximately 1 billion myoblasts were implanted <span>through 20 injections into the infarcted myocardium following CABG. <b>Results: </b><u>Safety</u> No subject suffered death, viral infection, malignant arrhythmia, reduction in cardiac output, immune rejection, or aneurysm growth. No significant difference was found before versus after treatment in the mean levels of blood routine, liver and kidney enzymes, electrolytes and fibrinogen. <u>Efficacy</u> Emission computed tomography (ECT) and magnetic resonance (MR) demonstrated significant increases in viability and perfusion. Mean left ventricular ejection fraction (LVEF) significantly increased (P < 0.05) by 20.1% and 19.3% at 6 months and at 2 years postoperatively. New York Heart Association (NYHA) class improved by 2 grades, including 6-minute walk test (6 MWT) distance increase, and reductions in the number of episodes of angina pectoris, chest tightness, shortness of breath after exercise, and nighttime sit-up breathing. <b>Conclusions: </b>For the first time, AMT in adjunct use with CABG and cyclosporine demonstrated that cell survived and engrafted in patients with ischemic cardiomyopathy;in this small study the cell transplant was safe. The improvement in heart function and quality of life could be secondary to combined effect of bypass and cell transplant. A larger randomized clinical trial is required to confirm the efficacy.
