With the development of nuclear energy, large amounts of radionuclides are inevitably released into the natural environment. It is necessary to eliminate radionuclides from wastewater for the protection of environment...With the development of nuclear energy, large amounts of radionuclides are inevitably released into the natural environment. It is necessary to eliminate radionuclides from wastewater for the protection of environment. Nanomaterials have been considered as the potential candidates for the effective and selective removal of radionuclides from aqueous solutions under complicated conditions because of their high specific surface area, large amounts of binding sites, abundant functional groups, pore-size controllable and easily surface modification. This review mainly summarized the recent studies for the synthesis, fabrication and surface modification of novel nanomaterials and their applications in the efficient elimination and solidification of radionuclides,and discussed the interaction mechanisms from batch experiments, spectroscopy analysis and theoretical calculations. The sorption capacities with other materials, advantages and disadvantages of different nanomaterials are compared, and at last the perspective of the novel nanomaterials is summarized.展开更多
The 18 kDa translocator protein(TSPO),previously known as the peripheral benzodiazepine receptor,is predominately localized to the outer mitochondrial membrane in steroidogenic cells.Brain TSPO expression is relativel...The 18 kDa translocator protein(TSPO),previously known as the peripheral benzodiazepine receptor,is predominately localized to the outer mitochondrial membrane in steroidogenic cells.Brain TSPO expression is relatively low under physiological conditions,but is upregulated in response to glial cell activation.As the primary index of neuroinflammation,TSPO is implicated in the pathogenesis and progression of numerous neuropsychiatric disorders and neurodegenerative diseases,including Alzheimer’s disease(AD),amyotrophic lateral sclerosis(ALS),Parkinson’s disease(PD),multiple sclerosis(MS),major depressive disorder(MDD)and obsessive compulsive disorder(OCD).In this context,numerous TSPO-targeted positron emission tomography(PET)tracers have been developed.Among them,several radioligands have advanced to clinical research studies.In this review,we will overview the recent development of TSPO PET tracers,focusing on the radioligand design,radioisotope labeling,pharmacokinetics,and PET imaging evaluation.Additionally,we will consider current limitations,as well as translational potential for future application of TSPO radiopharmaceuticals.This review aims to not only present the challenges in current TSPO PET imaging,but to also provide a new perspective on TSPO targeted PET tracer discovery efforts.Addressing these challenges will facilitate the translation of TSPO in clinical studies of neuroinflammation associated with central nervous system diseases.展开更多
Local hypoxia in solid tumors often results in resistance to radiotherapy （RT）, in which oxygen is an essential element for enhancing DNA damage caused by ionizing radiation. Herein, we developed gold@manganese diox...Local hypoxia in solid tumors often results in resistance to radiotherapy （RT）, in which oxygen is an essential element for enhancing DNA damage caused by ionizing radiation. Herein, we developed gold@manganese dioxide （Au@MnO2） core-shell nanoparticles with a polyethylene glycol （PEG） coating as a novel radiosensitizing agent to improve RT efficacy during cancer treatment. In this Au@MnO2 nanostructure, while the gold core is a well-known RT sensitizer that interacts with X-rays to produce charged particles for improved cancer killing under RT, the MnO2 shell may trigger the decomposition of endogenous H2O2 in the tumor microenvironment to generate oxygen and overcome hypoxiaassociated RT resistance. As demonstrated by both in vitro and in vivo experiments, Au@MnO2-PEG nanoparticles acted as effective radiosensitizers to remarkably enhance cancer treatment efficacy during RT. Moreover, no obvious side effects of Au@MnO2-PEG were observed in mice. Therefore, our work presents a new type of radiosensitizer with potential for enhanced RT treatment of hypoxic tumors.展开更多
Bacterial infections may lead to diverse acute or chronic diseases （e.g., inflammation, sepsis and cancer）. New antibiotics against bacteria are rarely discovered in recent years, which necessitates the exploration ...Bacterial infections may lead to diverse acute or chronic diseases （e.g., inflammation, sepsis and cancer）. New antibiotics against bacteria are rarely discovered in recent years, which necessitates the exploration of new antibacterial agents. Engineered nanomatetials {ENMs） have been extensively studied for antibacterial use because of their long lasting killing effects in wide spectra of bacteria. Graphene oxide （GO） is one of the most widely studied ENMs and exhibit strong bactericidal effects. The physicochemical properties of GO play important roles in bacterial killing by triggering a cascade of toxic events. Many studies have explored the signaling pathways of GO in bacteria. Although molecular initiating events （MIEs） of GO in bacteria dominate its killing efficiency as well as toxicity mechanisms, they have been rarely reviewed. In this report, we discussed the structure-activity relationships （SARs） involved in GOinduced bacterial killing and the MIEs including redox reaction with biomolecules, mechanical destruction of membranes and catalysis of extracellular metabolites. Furthermore, we summarized the clinical or commercial applications of GO-based antibacterial products and discussed their biosafety in mammal. Finally, we reviewed the remaining challenges in GO for antibacterial applications, which may offer new insights for the development of nano antibacterial studies.展开更多
Peptide-based materials that have diverse structures and functionalities are an important type of biomaterials.In former times,peptide-based nanomaterials with excellent stability were constructed through self-assembl...Peptide-based materials that have diverse structures and functionalities are an important type of biomaterials.In former times,peptide-based nanomaterials with excellent stability were constructed through self-assembly.Compared with individual peptides,peptide-based self-assembly nanomaterials that form well-ordered superstructures possess many advantages such as good thermo-and mechanical stability,semiconductivity,piezoelectricity and optical properties.Moreover,due to their excellent biocompatibility and biological activity,peptide-based self-assembly nanomaterials have been vastly used in different fields.In this review,we provide the advances of peptide-based self-assembly nanostructures,focusing on the driving forces that dominate peptide self-assembly and assembly mechanisms of peptides.After that,we outline the synthesis and properties of peptide-based nanomaterials,followed by the applications of functional peptide nanomaterials.Finally,we provide perspectives on the challenges and future of peptide-based nanomaterials.展开更多
Background:Colorectal cancer is harmful to the patient’s life.The treatment of patients is determined by accurate preoperative staging.Magnetic resonance imaging(MRI)played an important role in the preoperative exami...Background:Colorectal cancer is harmful to the patient’s life.The treatment of patients is determined by accurate preoperative staging.Magnetic resonance imaging(MRI)played an important role in the preoperative examination of patients with rectal cancer,and artificial intelligence(AI)in the learning of images made significant achievements in recent years.Introducing AI into MRI recognition,a stable platform for image recognition and judgment can be established in a short period.This study aimed to establish an automatic diagnostic platform for predicting preoperative T staging of rectal cancer through a deep neural network.Methods:A total of 183 rectal cancer patients’data were collected retrospectively as research objects.Faster region-based convolutional neural networks(Faster R-CNN)were used to build the platform.And the platform was evaluated according to the receiver operating characteristic(ROC)curve.Results:An automatic diagnosis platform for T staging of rectal cancer was established through the study of MRI.The areas under the ROC curve(AUC)were 0.99 in the horizontal plane,0.97 in the sagittal plane,and 0.98 in the coronal plane.In the horizontal plane,the AUC of T1 stage was 1,AUC of T2 stage was 1,AUC of T3 stage was 1,AUC of T4 stage was 1.In the coronal plane,AUC of T1 stage was 0.96,AUC of T2 stage was 0.97,AUC of T3 stage was 0.97,AUC of T4 stage was 0.97.In the sagittal plane,AUC of T1 stage was 0.95,AUC of T2 stage was 0.99,AUC of T3 stage was 0.96,and AUC of T4 stage was 1.00.Conclusion:Faster R-CNN AI might be an effective and objective method to build the platform for predicting rectal cancer T-staging.Trial registration:chictr.org.cn:ChiCTR1900023575;http://www.chictr.org.cn/showproj.aspx?proj=39665.展开更多
In recent years, semiconductor survey meters have been developed and are in increasing demand worldwide. This study determined if it is possible to use the X-ray system installed in each medical facility to calculate ...In recent years, semiconductor survey meters have been developed and are in increasing demand worldwide. This study determined if it is possible to use the X-ray system installed in each medical facility to calculate the time constant of a semiconductor survey meter and confirm the meter’s function. An additional filter was attached to the medical X-ray system to satisfy the standards of N-60 to N-120, more copper plates were added as needed, and the first and second half-value layers were calculated to enable comparisons of the facility’s X-ray system quality with the N-60 to N-120 quality values. Next, we used a medical X-ray system to measure the leakage dose and calculate the time constant of the survey meter. The functionality of the meter was then checked and compared with the energy characteristics of the meter. The experimental results showed that it was possible to use a medical X-ray system to reproduce the N-60 to N-120 radiation quality values and to calculate the time constant from the measured results, assuming actual leakage dosimetry for that radiation quality. We also found that the calibration factor was equivalent to that of the energy characteristics of the survey meter.展开更多
AIM To investigate near-infrared photoimmunotherapeutic effect mediated by an anti-tissue factor(TF) antibody conjugated to indocyanine green(ICG) in a pancreatic cancer model.METHODS Near-infrared photoimmunotherapy(...AIM To investigate near-infrared photoimmunotherapeutic effect mediated by an anti-tissue factor(TF) antibody conjugated to indocyanine green(ICG) in a pancreatic cancer model.METHODS Near-infrared photoimmunotherapy(NIR-PIT) is a highly selective tumor treatment that utilizes an antibody-photosensitizer conjugate administration, followed by NIR light exposure. Anti-TF antibody 1849-ICG conjugate was synthesized by labeling of rat IgG2 b anti-TF monoclonal antibody 1849(anti-TF 1849) to a NIR photosensitizer,ICG. The expression levels of TF in two human pancreatic cancer cell lines were examined by western blotting. Specific binding of the 1849-ICG to TF-expressing BxPC-3 cells was examined by fluorescence microscopy. NIR-PITinduced cell death was determined by cell viability imaging assay. In vivo longitudinal fluorescence imaging was used to explore the accumulation of 1849-ICG conjugate in xenograft tumors. To examine the effect of NIRPIT, tumor-bearing mice were separated into 5 groups:(1) 100 μg of 1849-ICG i.v. administration followed by NIR light exposure(50 J/cm2) on two consecutive days(Days 1 and 2);(2) NIR light exposure(50 J/cm2) only on two consecutive days(Days 1 and 2);(3) 100 μg of 1849-ICG i.v. administration;(4) 100 μg of unlabeled antiTF 1849 i.v. administration; and(5) the untreated control. Semiweekly tumor volume measurements, accompanied with histological and immunohistochemical(IHC) analyses of tumors, were performed 3 d after the 2nd irradiation with NIR light to monitor the effect of treatments. RESULTS High TF expression in BxPC-3 cells was observed via western blot analysis, concordant with the observed preferential binding with intracellular localization of 1849-ICG via fluorescence microscopy. NIR-PIT-induced cell death was observed by performing cell viability imaging assay. In contrast to the other test groups, tumor growth was significantly inhibited by NIR-PIT with a statistically significant difference in relative tumor volumes for 27 d after the treatment start date [2.83 ±展开更多
Objectives: Hydrogel spacer (HS) was developed to reduce rectal toxicities caused by radiotherapy, but has been reported to cause major adverse events. Our institute has attempted to introduce a hyaluronic acid (HA) a...Objectives: Hydrogel spacer (HS) was developed to reduce rectal toxicities caused by radiotherapy, but has been reported to cause major adverse events. Our institute has attempted to introduce a hyaluronic acid (HA) as an alternative spacer. This study aimed to compare rectal doses and geometric distributions between the HS and HA implantation in prostate cancer.Methods: HS and HA were inserted in 20 and 18 patients undergoing high-dose brachytherapy, respectively. The rectum spacer volumes injected were 10 mL and 22 mL, respectively. In the treatment planning system, 13.5 Gy was administered with common catheter positions. The rectal dose indices were assessed between the spacer groups for dosimetry evaluation. Distances between the prostate and rectum and configurations of the spacers were compared.Results: The mean doses irradiated to 0.1 and 2 mL of the rectum were 10.45 Gy and 6.71 Gy for HS, and 6.73 Gy and 4.90 Gy for HA (p<0.001). The mean minimum distances between the prostate and rectum were 1.23 cm and 1.79 cm for HS and HA, respectively (p<0.05). Geometrical configuration comparisons revealed that HA has a higher ability to expand the space than HS.Conclusion: The rectal dose reduction ability of HA is significantly greater than that of HS, suggesting its potential as a new spacer.展开更多
Cross entropy is a measure in machine learning and deep learning that assesses the difference between predicted and actual probability distributions. In this study, we propose cross entropy as a performance evaluation...Cross entropy is a measure in machine learning and deep learning that assesses the difference between predicted and actual probability distributions. In this study, we propose cross entropy as a performance evaluation metric for image classifier models and apply it to the CT image classification of lung cancer. A convolutional neural network is employed as the deep neural network (DNN) image classifier, with the residual network (ResNet) 50 chosen as the DNN archi-tecture. The image data used comprise a lung CT image set. Two classification models are built from datasets with varying amounts of data, and lung cancer is categorized into four classes using 10-fold cross-validation. Furthermore, we employ t-distributed stochastic neighbor embedding to visually explain the data distribution after classification. Experimental results demonstrate that cross en-tropy is a highly useful metric for evaluating the reliability of image classifier models. It is noted that for a more comprehensive evaluation of model perfor-mance, combining with other evaluation metrics is considered essential. .展开更多
Developing efficient adsorbents for radon(Rn)capture from the ambient environment is of paramount importance for public health.However,it poses a great challenge due to the chemical inertness and extremely low molar c...Developing efficient adsorbents for radon(Rn)capture from the ambient environment is of paramount importance for public health.However,it poses a great challenge due to the chemical inertness and extremely low molar concentration of Rn in air.Herein,we report a zeolite imidazolate frameworkderived metallic carbon adsorbent(Zn@NPC)with record high Rn removal performance under ambient conditions.Upon one-step pyrolysis,the prepared Zn@NPC possesses pores with a preference for Rn and atomically dispersed Zn sites,achieving a high Rn removal efficiency that doubles in adsorption coefficient(9.47 L·g^(−1))and triples in adsorption kinetic coefficient(20.25 mL·g^(−1)·min^(−1))over the benchmark Rn adsorbent coconut activated charcoal.Density functional theory calculations elucidate the important role of the metal polarization effect,which cooperates with the pore size confinement effect to boost the overall Rn adsorption performance.This work launches a promising alternative for practical Rn capture.展开更多
Dual-layer spectral detector CT is a new spectrum CT imaging technology based on detector being able to obtain both images similar to true plain and spectral images in one time scanning.The reconstructed multi-paramet...Dual-layer spectral detector CT is a new spectrum CT imaging technology based on detector being able to obtain both images similar to true plain and spectral images in one time scanning.The reconstructed multi-parameter spectral images can not only improve image quality,enhance tissue contrast,increase the visualization and detection ability of occult lesions,but also provide qualitative and quantitative analysis of the lesions,so as to provide more imaging information and multi-dimensional diagnostic basis.The research progresses of dual-layer spectral detector CT for preoperative evaluation on colorectal cancer were reviewed in this article.展开更多
BACKGROUND Intrapancreatic fat deposition(IPFD)exerts a significant negative impact on patients with type 2 diabetes mellitus(T2DM),accelerates disease deterioration,and may lead to impairedβ-cell quality and functio...BACKGROUND Intrapancreatic fat deposition(IPFD)exerts a significant negative impact on patients with type 2 diabetes mellitus(T2DM),accelerates disease deterioration,and may lead to impairedβ-cell quality and function.AIM To investigate the correlation between T2DM remission and IPFD.METHODS We enrolled 80 abdominally obese patients with T2DM admitted to our institution from January 2019 to October 2023,including 40 patients with weight lossinduced T2DM remission(research group)and 40 patients with short-term intensive insulin therapy-induced T2DM remission(control group).We comparatively analyzed improvements in IPFD[differential computed tomography(CT)values of the spleen and pancreas and average CT value of the pancreas];levels of fasting blood glucose(FBG),2-h postprandial blood glucose(2hPBG),and insulin;and homeostasis model assessment of insulin resistance(HOMA-IR)scores.Correlation analysis was performed to explore the association between T2DM remission and IPFD.RESULTS After treatment,the differential CT values of the spleen and pancreas,FBG,2hPBG,and HOMA-IR in the research group were significantly lower than those before treatment and in the control group,and the average CT value of the pancreas and insulin levels were significantly higher.Correlation analysis revealed that the greater the T2DM remission,the lower the amount of IPFD.展开更多
As a new generation of artificial enzymes,nanozymes show outstanding advantages such as high stability,low cost,and facile synthesis,which endow them with promising applications in biomedical and environmental fields....As a new generation of artificial enzymes,nanozymes show outstanding advantages such as high stability,low cost,and facile synthesis,which endow them with promising applications in biomedical and environmental fields.Among the various reported nanozymes,metal-organic frameworks(MOFs)could mimic the active center of natural enzymes and provide a hydrophobic environment,which makes MOFs attractive alternatives to natural enzymes.Owing to the highly structural diversity and tailorability of MOFs,rational design will contribute to improve the activity of MOF-based nanozymes and promote their potential applications in both biomedical and environmental fields.Therefore,a comprehensiye suminary of activity regulatory strategies of MOF-based nanozymes is urgently needed.Firstly,we summarized the activity regulatory strategies of MOFs with intrinsic enzyme-like activities via modulation of metal nodes,ligands,structures and morphologies.Then the applications of MOF-based nanozymes in biosensing,hazardous degradation,antibacterial,and cancer therapy were also introduced.Finally,the current challenges and future perspectives were discussed in depth.It is highly expected that this review will provide a better understanding on the rational design of novel high-performance MOF-based nanozymes.展开更多
Objectives: This study aimed to determine whether errors in vascular measurements would affect device selection in endovascular aortic repair (EVAR) by comparing measurements obtained using non-contrast computed tomog...Objectives: This study aimed to determine whether errors in vascular measurements would affect device selection in endovascular aortic repair (EVAR) by comparing measurements obtained using non-contrast computed tomography (NCT) with those obtained using contrast-enhanced CT (CECT). Materials and Methods: This single-center, retrospective study included 25 patients who underwent EVAR for abdominal aortic aneurysm at our institution. A 1-mm horizontal cross-sectional slice of NCT and CECT from each patient was retrospectively reviewed. The area from the abdominal aorta to the common iliac artery was divided into four zones. A centerline was created using the NCT by manually plotting the center points. Subsequently, the centerlines were automatically extracted and manually corrected during the arterial phase of CECT. The diameter and length of each zone were measured for each modality. The mean diameters and lengths of the target vessels were compared between NCT and CECT. Results: The measurements obtained using both methods were reproducible and demonstrated good agreement. The mean differences in vessel length and diameter measurements for each segment between NCT and CECT were not statistically significant, indicating good consistency. Conclusion: NCT may be useful for preoperative EVAR evaluation in patients with renal dysfunction or allergies to contrast agents.展开更多
This study evaluates the performance and reliability of a vision transformer (ViT) compared to convolutional neural networks (CNNs) using the ResNet50 model in classifying lung cancer from CT images into four categori...This study evaluates the performance and reliability of a vision transformer (ViT) compared to convolutional neural networks (CNNs) using the ResNet50 model in classifying lung cancer from CT images into four categories: lung adenocarcinoma (LUAD), lung squamous cell carcinoma (LUSC), large cell carcinoma (LULC), and normal. Although CNNs have made significant advancements in medical imaging, their limited capacity to capture long-range dependencies has led to the exploration of ViTs, which leverage self-attention mechanisms for a more comprehensive global understanding of images. The study utilized a dataset of 748 lung CT images to train both models with standardized input sizes, assessing their performance through conventional metrics—accuracy, precision, recall, F1 score, specificity, and AUC—as well as cross entropy, a novel metric for evaluating prediction uncertainty. Both models achieved similar accuracy rates (95%), with ViT demonstrating a slight edge over ResNet50 in precision and F1 scores for specific classes. However, ResNet50 exhibited higher recall for LULC, indicating fewer missed cases. Cross entropy analysis showed that the ViT model had lower average uncertainty, particularly in the LUAD, Normal, and LUSC classes, compared to ResNet50. This finding suggests that ViT predictions are generally more reliable, though ResNet50 performed better for LULC. The study underscores that accuracy alone is insufficient for model comparison, as cross entropy offers deeper insights into the reliability and confidence of model predictions. The results highlight the importance of incorporating cross entropy alongside traditional metrics for a more comprehensive evaluation of deep learning models in medical image classification, providing a nuanced understanding of their performance and reliability. While the ViT outperformed the CNN-based ResNet50 in lung cancer classification based on cross-entropy values, the performance differences were minor and may not hold clinical significance. Therefore, it may be p展开更多
Background: Nosocomial infections have become a major challenge in healthcare facilities as they affect the quality of medical care. Radiological imaging plays a crucial role in medical diagnosis. However, the equipme...Background: Nosocomial infections have become a major challenge in healthcare facilities as they affect the quality of medical care. Radiological imaging plays a crucial role in medical diagnosis. However, the equipment and accessories used increase the risk of transmission of nosocomial bacteria. Objective: This study aims to reveal the extent and nature of microbiological contamination in four hospital diagnostic imaging departments to determine their potential role in the spread of nosocomial bacteria and to evaluate the effectiveness of routine daily disinfection practices in controlling microorganisms in diagnostic imaging departments. Methods & Results: In each department, swabs were taken from the surfaces of selected parts of the equipment and accessories three times a day (early morning, noon, and evening) for five consecutive days. Bacteria were isolated from 65 swabs (36.1% of all samples). The bacteria were isolated 3 times (4.6%) in the morning, 16 times (24.6%) at midday, and 46 times (70.7%) in the evening. The bacteria isolated were Escherichia coli (isolated 34 times;52.3%), Staphylococcus aureus (20 times;30.8%), Staphylococcus epidermidis (6 times;9.3%), and Klebsiella species (5 times;7.7%). Discussion & Conclusion: Findings demonstrated that radiology equipment and accessories are not free of bacteria and further improvements in the sterilization and disinfection of radiology equipment and accessories are needed to protect staff and patients from nosocomial infections.展开更多
Harnessing solar energy by photocatalytically converting oxygen and water into high-value-added H_(2)O_(2)is a promising way of alleviating both environmental and energy issues.It is worth noting that suppressing detr...Harnessing solar energy by photocatalytically converting oxygen and water into high-value-added H_(2)O_(2)is a promising way of alleviating both environmental and energy issues.It is worth noting that suppressing detrimental side reactions,such as the generation of·O_(2)^(-),is a critical approach to enhancing H_(2)O_(2)production.Herein,a 2-fold interpenetrating 3D uranium-organic framework(YTU-W-1)was developed and introduced for photocatalytic H_(2)O_(2)production.The material demonstrates a different photocatalytic mechanism when employing uranyl as an initiator,as compared with the conventional semiconductor photocatalytic pathway involving photo-generated charge carriers.Benefiting from the strong hydrogen abstraction effect of the U≡O·and the direct one-step oxygen reduction pathway,YTU-W-1 exhibits enhanced photocatalytic performance for H_(2)O_(2)production with yield efficiency of 221μmol h^(-1)g^(-1).Furthermore,YTU-W-1 displays a high H_(2)O_(2)selectivity of 68%,confirmed by rotating ring-disk electrode(RRDE)measurement.DFTcalculations were used to elucidate the critical role of uranyl in the photocatalytic oxygen reduction reaction for H_(2)O_(2)production.This research introduces an innovative approach to photo-driven H_(2)O_(2)production,underscoring the potential for heterogeneous catalysts to engage in photocatalytic reactions independently of photogenerated charge carriers.展开更多
This paper addresses the manipulation of structural,morphology,optical and magnetic properties of LiCo0.25Zn0.25Fe2 O4 ferrite via incorporation of different proportions of La^3+at the expense of iron ions using a sol...This paper addresses the manipulation of structural,morphology,optical and magnetic properties of LiCo0.25Zn0.25Fe2 O4 ferrite via incorporation of different proportions of La^3+at the expense of iron ions using a sol-gel method.The samples were characterized using the X-ray diffraction technique(XRD),Fourier transform infrared(FT-IR)spectroscopy,the energy dispersive X-ray spectra(EDX),inductively coupled plasma optical emission spectroscopy(ICP-OES),high resolution scanning electron microscopy(SEM),Brunauer-Emmett-Teller(BET)surface area analysis,ultraviolet-diffuse reflectance spectroscopy(UV-DRS),and vibrating sample magnetometer(VSM)technique.The Rietveld refinements of the samples indicate that at higher concentrations of La^3+,nanostructures with dual phase,i.e.cubic spinel and orthorhombic LaFeO3 perovskite with space group(Pbnm)appear.Optical studies show that the energy band gap(Eg)of the bare LiCo0.25Zn0.25Fe2 O4 ferrite sample(2.18 eV)reaches up to 2.47 eV at x=0.06 and above this concentration,it drops sharply to 2.00 eV.Although the saturation magnetization and the coercivity of LiCo0.25Zn0.25LaxFe2-xO4 are lower than that of LiCo0.25Zn0.25Fe2 O4 NPs.Overall,the superparamagnetic nature and low values of saturation magnetization and coercivity of LiCo0.25Zn0.25LaxFe2-xO4 NPs are suitable to be applied in transformers core.展开更多
In this paper,we propose a novel stacked laser dielectric acceleration structure.This structure is based on the inverse Cherenkov effect and represented by a parametric design formulation.Compared to existing dielectr...In this paper,we propose a novel stacked laser dielectric acceleration structure.This structure is based on the inverse Cherenkov effect and represented by a parametric design formulation.Compared to existing dielectric laser accelerators relying on the inverse Smith–Purcell effect,the proposed structure provides an extended-duration synchronous acceleration field without requiring the pulse front tilting technique.This advantage significantly reduces the required pulse duration.In addition,the easy to integrate layered structure facilitates cascade acceleration,and simulations have shown that low-energy electron beams can be cascaded through high gradients over extended distances.These practical advantages demonstrate the potential of this new structure for future chip accelerators.展开更多
基金supported by the Science Challenge Project (TZ2016004)the National Natural Science Foundation of China (21836001, 21876048)
文摘With the development of nuclear energy, large amounts of radionuclides are inevitably released into the natural environment. It is necessary to eliminate radionuclides from wastewater for the protection of environment. Nanomaterials have been considered as the potential candidates for the effective and selective removal of radionuclides from aqueous solutions under complicated conditions because of their high specific surface area, large amounts of binding sites, abundant functional groups, pore-size controllable and easily surface modification. This review mainly summarized the recent studies for the synthesis, fabrication and surface modification of novel nanomaterials and their applications in the efficient elimination and solidification of radionuclides,and discussed the interaction mechanisms from batch experiments, spectroscopy analysis and theoretical calculations. The sorption capacities with other materials, advantages and disadvantages of different nanomaterials are compared, and at last the perspective of the novel nanomaterials is summarized.
基金support of K.C.Wong Education Foundation(China)the Project of Innovative Team for the Guangdong Universities(2018KCXTD001,China)+1 种基金financially supported by the National Natural Science Foundation of China(Nos.81701751 and 81871383)Guangdong Basic and Applied Basic Research Foundation(2020A1515011192,China)
文摘The 18 kDa translocator protein(TSPO),previously known as the peripheral benzodiazepine receptor,is predominately localized to the outer mitochondrial membrane in steroidogenic cells.Brain TSPO expression is relatively low under physiological conditions,but is upregulated in response to glial cell activation.As the primary index of neuroinflammation,TSPO is implicated in the pathogenesis and progression of numerous neuropsychiatric disorders and neurodegenerative diseases,including Alzheimer’s disease(AD),amyotrophic lateral sclerosis(ALS),Parkinson’s disease(PD),multiple sclerosis(MS),major depressive disorder(MDD)and obsessive compulsive disorder(OCD).In this context,numerous TSPO-targeted positron emission tomography(PET)tracers have been developed.Among them,several radioligands have advanced to clinical research studies.In this review,we will overview the recent development of TSPO PET tracers,focusing on the radioligand design,radioisotope labeling,pharmacokinetics,and PET imaging evaluation.Additionally,we will consider current limitations,as well as translational potential for future application of TSPO radiopharmaceuticals.This review aims to not only present the challenges in current TSPO PET imaging,but to also provide a new perspective on TSPO targeted PET tracer discovery efforts.Addressing these challenges will facilitate the translation of TSPO in clinical studies of neuroinflammation associated with central nervous system diseases.
基金This work was partially supported by the National Basic Research Program of China （973 Program, Nos. 2014CB931900 and 2012CB932600）, National Natural Science Foundation of China （Nos. 81471716 and 31400861）, the National Natural Science Foundation of Jiangsu Province （No. BK20140320）, and a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions （PAPD）.
文摘Local hypoxia in solid tumors often results in resistance to radiotherapy （RT）, in which oxygen is an essential element for enhancing DNA damage caused by ionizing radiation. Herein, we developed gold@manganese dioxide （Au@MnO2） core-shell nanoparticles with a polyethylene glycol （PEG） coating as a novel radiosensitizing agent to improve RT efficacy during cancer treatment. In this Au@MnO2 nanostructure, while the gold core is a well-known RT sensitizer that interacts with X-rays to produce charged particles for improved cancer killing under RT, the MnO2 shell may trigger the decomposition of endogenous H2O2 in the tumor microenvironment to generate oxygen and overcome hypoxiaassociated RT resistance. As demonstrated by both in vitro and in vivo experiments, Au@MnO2-PEG nanoparticles acted as effective radiosensitizers to remarkably enhance cancer treatment efficacy during RT. Moreover, no obvious side effects of Au@MnO2-PEG were observed in mice. Therefore, our work presents a new type of radiosensitizer with potential for enhanced RT treatment of hypoxic tumors.
基金supported by the National Natural Science Foundation of China (31671032)Key Project of Natural Science Foundation of the Higher Education Institutions of Jiangsu Province (17KJA310003)+2 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)supported by the Recruitment Program of Global Youth Experts of ChinaStrategic Project for Developing Outstanding Institutes in Suzhou (MCMX201604)
文摘Bacterial infections may lead to diverse acute or chronic diseases （e.g., inflammation, sepsis and cancer）. New antibiotics against bacteria are rarely discovered in recent years, which necessitates the exploration of new antibacterial agents. Engineered nanomatetials {ENMs） have been extensively studied for antibacterial use because of their long lasting killing effects in wide spectra of bacteria. Graphene oxide （GO） is one of the most widely studied ENMs and exhibit strong bactericidal effects. The physicochemical properties of GO play important roles in bacterial killing by triggering a cascade of toxic events. Many studies have explored the signaling pathways of GO in bacteria. Although molecular initiating events （MIEs） of GO in bacteria dominate its killing efficiency as well as toxicity mechanisms, they have been rarely reviewed. In this report, we discussed the structure-activity relationships （SARs） involved in GOinduced bacterial killing and the MIEs including redox reaction with biomolecules, mechanical destruction of membranes and catalysis of extracellular metabolites. Furthermore, we summarized the clinical or commercial applications of GO-based antibacterial products and discussed their biosafety in mammal. Finally, we reviewed the remaining challenges in GO for antibacterial applications, which may offer new insights for the development of nano antibacterial studies.
基金supported by Beijing Natural Science Foundation(JQ20038)the National Natural Science Foundation of China(61875015,T2125003,and 21801019)+1 种基金JSPS KAKENHI(Grant No.21H02873)JSPS International Joint Research Program(JPJSBP120207203).
文摘Peptide-based materials that have diverse structures and functionalities are an important type of biomaterials.In former times,peptide-based nanomaterials with excellent stability were constructed through self-assembly.Compared with individual peptides,peptide-based self-assembly nanomaterials that form well-ordered superstructures possess many advantages such as good thermo-and mechanical stability,semiconductivity,piezoelectricity and optical properties.Moreover,due to their excellent biocompatibility and biological activity,peptide-based self-assembly nanomaterials have been vastly used in different fields.In this review,we provide the advances of peptide-based self-assembly nanostructures,focusing on the driving forces that dominate peptide self-assembly and assembly mechanisms of peptides.After that,we outline the synthesis and properties of peptide-based nanomaterials,followed by the applications of functional peptide nanomaterials.Finally,we provide perspectives on the challenges and future of peptide-based nanomaterials.
基金National Natural Science Foundation of China(No.81802888)Key Research and Development Project of Shandong Province(No.2018GSF118206+1 种基金No.2018GSF118088)Natural Science Foundation of Shandong Province(No.ZR2019PF017)。
文摘Background:Colorectal cancer is harmful to the patient’s life.The treatment of patients is determined by accurate preoperative staging.Magnetic resonance imaging(MRI)played an important role in the preoperative examination of patients with rectal cancer,and artificial intelligence(AI)in the learning of images made significant achievements in recent years.Introducing AI into MRI recognition,a stable platform for image recognition and judgment can be established in a short period.This study aimed to establish an automatic diagnostic platform for predicting preoperative T staging of rectal cancer through a deep neural network.Methods:A total of 183 rectal cancer patients’data were collected retrospectively as research objects.Faster region-based convolutional neural networks(Faster R-CNN)were used to build the platform.And the platform was evaluated according to the receiver operating characteristic(ROC)curve.Results:An automatic diagnosis platform for T staging of rectal cancer was established through the study of MRI.The areas under the ROC curve(AUC)were 0.99 in the horizontal plane,0.97 in the sagittal plane,and 0.98 in the coronal plane.In the horizontal plane,the AUC of T1 stage was 1,AUC of T2 stage was 1,AUC of T3 stage was 1,AUC of T4 stage was 1.In the coronal plane,AUC of T1 stage was 0.96,AUC of T2 stage was 0.97,AUC of T3 stage was 0.97,AUC of T4 stage was 0.97.In the sagittal plane,AUC of T1 stage was 0.95,AUC of T2 stage was 0.99,AUC of T3 stage was 0.96,and AUC of T4 stage was 1.00.Conclusion:Faster R-CNN AI might be an effective and objective method to build the platform for predicting rectal cancer T-staging.Trial registration:chictr.org.cn:ChiCTR1900023575;http://www.chictr.org.cn/showproj.aspx?proj=39665.
文摘In recent years, semiconductor survey meters have been developed and are in increasing demand worldwide. This study determined if it is possible to use the X-ray system installed in each medical facility to calculate the time constant of a semiconductor survey meter and confirm the meter’s function. An additional filter was attached to the medical X-ray system to satisfy the standards of N-60 to N-120, more copper plates were added as needed, and the first and second half-value layers were calculated to enable comparisons of the facility’s X-ray system quality with the N-60 to N-120 quality values. Next, we used a medical X-ray system to measure the leakage dose and calculate the time constant of the survey meter. The functionality of the meter was then checked and compared with the energy characteristics of the meter. The experimental results showed that it was possible to use a medical X-ray system to reproduce the N-60 to N-120 radiation quality values and to calculate the time constant from the measured results, assuming actual leakage dosimetry for that radiation quality. We also found that the calibration factor was equivalent to that of the energy characteristics of the survey meter.
基金Supported by a Grant-in-Aid for Scientific Research(C)from the Ministry of Education,Culture,Sports,Science,and Technology,Japan,No.17K10460(to Aung W)
文摘AIM To investigate near-infrared photoimmunotherapeutic effect mediated by an anti-tissue factor(TF) antibody conjugated to indocyanine green(ICG) in a pancreatic cancer model.METHODS Near-infrared photoimmunotherapy(NIR-PIT) is a highly selective tumor treatment that utilizes an antibody-photosensitizer conjugate administration, followed by NIR light exposure. Anti-TF antibody 1849-ICG conjugate was synthesized by labeling of rat IgG2 b anti-TF monoclonal antibody 1849(anti-TF 1849) to a NIR photosensitizer,ICG. The expression levels of TF in two human pancreatic cancer cell lines were examined by western blotting. Specific binding of the 1849-ICG to TF-expressing BxPC-3 cells was examined by fluorescence microscopy. NIR-PITinduced cell death was determined by cell viability imaging assay. In vivo longitudinal fluorescence imaging was used to explore the accumulation of 1849-ICG conjugate in xenograft tumors. To examine the effect of NIRPIT, tumor-bearing mice were separated into 5 groups:(1) 100 μg of 1849-ICG i.v. administration followed by NIR light exposure(50 J/cm2) on two consecutive days(Days 1 and 2);(2) NIR light exposure(50 J/cm2) only on two consecutive days(Days 1 and 2);(3) 100 μg of 1849-ICG i.v. administration;(4) 100 μg of unlabeled antiTF 1849 i.v. administration; and(5) the untreated control. Semiweekly tumor volume measurements, accompanied with histological and immunohistochemical(IHC) analyses of tumors, were performed 3 d after the 2nd irradiation with NIR light to monitor the effect of treatments. RESULTS High TF expression in BxPC-3 cells was observed via western blot analysis, concordant with the observed preferential binding with intracellular localization of 1849-ICG via fluorescence microscopy. NIR-PIT-induced cell death was observed by performing cell viability imaging assay. In contrast to the other test groups, tumor growth was significantly inhibited by NIR-PIT with a statistically significant difference in relative tumor volumes for 27 d after the treatment start date [2.83 ±
文摘Objectives: Hydrogel spacer (HS) was developed to reduce rectal toxicities caused by radiotherapy, but has been reported to cause major adverse events. Our institute has attempted to introduce a hyaluronic acid (HA) as an alternative spacer. This study aimed to compare rectal doses and geometric distributions between the HS and HA implantation in prostate cancer.Methods: HS and HA were inserted in 20 and 18 patients undergoing high-dose brachytherapy, respectively. The rectum spacer volumes injected were 10 mL and 22 mL, respectively. In the treatment planning system, 13.5 Gy was administered with common catheter positions. The rectal dose indices were assessed between the spacer groups for dosimetry evaluation. Distances between the prostate and rectum and configurations of the spacers were compared.Results: The mean doses irradiated to 0.1 and 2 mL of the rectum were 10.45 Gy and 6.71 Gy for HS, and 6.73 Gy and 4.90 Gy for HA (p<0.001). The mean minimum distances between the prostate and rectum were 1.23 cm and 1.79 cm for HS and HA, respectively (p<0.05). Geometrical configuration comparisons revealed that HA has a higher ability to expand the space than HS.Conclusion: The rectal dose reduction ability of HA is significantly greater than that of HS, suggesting its potential as a new spacer.
文摘Cross entropy is a measure in machine learning and deep learning that assesses the difference between predicted and actual probability distributions. In this study, we propose cross entropy as a performance evaluation metric for image classifier models and apply it to the CT image classification of lung cancer. A convolutional neural network is employed as the deep neural network (DNN) image classifier, with the residual network (ResNet) 50 chosen as the DNN archi-tecture. The image data used comprise a lung CT image set. Two classification models are built from datasets with varying amounts of data, and lung cancer is categorized into four classes using 10-fold cross-validation. Furthermore, we employ t-distributed stochastic neighbor embedding to visually explain the data distribution after classification. Experimental results demonstrate that cross en-tropy is a highly useful metric for evaluating the reliability of image classifier models. It is noted that for a more comprehensive evaluation of model perfor-mance, combining with other evaluation metrics is considered essential. .
基金funding support from the National Key R&D Program of China(grant nos.2021YFB3200400 and 2022YFE0105300)the New Cornerstone Science Foundation through the XPLORER PRIZE,the National Natural Science Foundation of China(grant nos.22276131,21825601,U21A20296,U1967217,12275190,U1932124,and 22206144)+2 种基金the Science Foundation of Jiangsu Province(grant no.BK20220026)the China-Portugal Joint Laboratory of Cultural Heritage Conservation Science(grant no.2021YFE0200100)Soochow University-Western University Centre for Synchrotron Radiation Research.
文摘Developing efficient adsorbents for radon(Rn)capture from the ambient environment is of paramount importance for public health.However,it poses a great challenge due to the chemical inertness and extremely low molar concentration of Rn in air.Herein,we report a zeolite imidazolate frameworkderived metallic carbon adsorbent(Zn@NPC)with record high Rn removal performance under ambient conditions.Upon one-step pyrolysis,the prepared Zn@NPC possesses pores with a preference for Rn and atomically dispersed Zn sites,achieving a high Rn removal efficiency that doubles in adsorption coefficient(9.47 L·g^(−1))and triples in adsorption kinetic coefficient(20.25 mL·g^(−1)·min^(−1))over the benchmark Rn adsorbent coconut activated charcoal.Density functional theory calculations elucidate the important role of the metal polarization effect,which cooperates with the pore size confinement effect to boost the overall Rn adsorption performance.This work launches a promising alternative for practical Rn capture.
文摘Dual-layer spectral detector CT is a new spectrum CT imaging technology based on detector being able to obtain both images similar to true plain and spectral images in one time scanning.The reconstructed multi-parameter spectral images can not only improve image quality,enhance tissue contrast,increase the visualization and detection ability of occult lesions,but also provide qualitative and quantitative analysis of the lesions,so as to provide more imaging information and multi-dimensional diagnostic basis.The research progresses of dual-layer spectral detector CT for preoperative evaluation on colorectal cancer were reviewed in this article.
基金Kunming University of Science and Technology Joint School Medicine Project,No.KUST-WS2022002Zthe Ethic Committee of Wenshan Hospital,Kunming University of Science and Technology(Approval No.WYLS2022005).
文摘BACKGROUND Intrapancreatic fat deposition(IPFD)exerts a significant negative impact on patients with type 2 diabetes mellitus(T2DM),accelerates disease deterioration,and may lead to impairedβ-cell quality and function.AIM To investigate the correlation between T2DM remission and IPFD.METHODS We enrolled 80 abdominally obese patients with T2DM admitted to our institution from January 2019 to October 2023,including 40 patients with weight lossinduced T2DM remission(research group)and 40 patients with short-term intensive insulin therapy-induced T2DM remission(control group).We comparatively analyzed improvements in IPFD[differential computed tomography(CT)values of the spleen and pancreas and average CT value of the pancreas];levels of fasting blood glucose(FBG),2-h postprandial blood glucose(2hPBG),and insulin;and homeostasis model assessment of insulin resistance(HOMA-IR)scores.Correlation analysis was performed to explore the association between T2DM remission and IPFD.RESULTS After treatment,the differential CT values of the spleen and pancreas,FBG,2hPBG,and HOMA-IR in the research group were significantly lower than those before treatment and in the control group,and the average CT value of the pancreas and insulin levels were significantly higher.Correlation analysis revealed that the greater the T2DM remission,the lower the amount of IPFD.
基金financially supported by the National Natural Science Foundation of China(Nos.31901000 and 22022609)the Natural Science Foundation of Jiangsu Higher Education Institutes of China(No.19KJA610003)+1 种基金the Postdoctoral Science Foundation of Jiangsu Province(No.2019K152)the Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions。
文摘As a new generation of artificial enzymes,nanozymes show outstanding advantages such as high stability,low cost,and facile synthesis,which endow them with promising applications in biomedical and environmental fields.Among the various reported nanozymes,metal-organic frameworks(MOFs)could mimic the active center of natural enzymes and provide a hydrophobic environment,which makes MOFs attractive alternatives to natural enzymes.Owing to the highly structural diversity and tailorability of MOFs,rational design will contribute to improve the activity of MOF-based nanozymes and promote their potential applications in both biomedical and environmental fields.Therefore,a comprehensiye suminary of activity regulatory strategies of MOF-based nanozymes is urgently needed.Firstly,we summarized the activity regulatory strategies of MOFs with intrinsic enzyme-like activities via modulation of metal nodes,ligands,structures and morphologies.Then the applications of MOF-based nanozymes in biosensing,hazardous degradation,antibacterial,and cancer therapy were also introduced.Finally,the current challenges and future perspectives were discussed in depth.It is highly expected that this review will provide a better understanding on the rational design of novel high-performance MOF-based nanozymes.
文摘Objectives: This study aimed to determine whether errors in vascular measurements would affect device selection in endovascular aortic repair (EVAR) by comparing measurements obtained using non-contrast computed tomography (NCT) with those obtained using contrast-enhanced CT (CECT). Materials and Methods: This single-center, retrospective study included 25 patients who underwent EVAR for abdominal aortic aneurysm at our institution. A 1-mm horizontal cross-sectional slice of NCT and CECT from each patient was retrospectively reviewed. The area from the abdominal aorta to the common iliac artery was divided into four zones. A centerline was created using the NCT by manually plotting the center points. Subsequently, the centerlines were automatically extracted and manually corrected during the arterial phase of CECT. The diameter and length of each zone were measured for each modality. The mean diameters and lengths of the target vessels were compared between NCT and CECT. Results: The measurements obtained using both methods were reproducible and demonstrated good agreement. The mean differences in vessel length and diameter measurements for each segment between NCT and CECT were not statistically significant, indicating good consistency. Conclusion: NCT may be useful for preoperative EVAR evaluation in patients with renal dysfunction or allergies to contrast agents.
文摘This study evaluates the performance and reliability of a vision transformer (ViT) compared to convolutional neural networks (CNNs) using the ResNet50 model in classifying lung cancer from CT images into four categories: lung adenocarcinoma (LUAD), lung squamous cell carcinoma (LUSC), large cell carcinoma (LULC), and normal. Although CNNs have made significant advancements in medical imaging, their limited capacity to capture long-range dependencies has led to the exploration of ViTs, which leverage self-attention mechanisms for a more comprehensive global understanding of images. The study utilized a dataset of 748 lung CT images to train both models with standardized input sizes, assessing their performance through conventional metrics—accuracy, precision, recall, F1 score, specificity, and AUC—as well as cross entropy, a novel metric for evaluating prediction uncertainty. Both models achieved similar accuracy rates (95%), with ViT demonstrating a slight edge over ResNet50 in precision and F1 scores for specific classes. However, ResNet50 exhibited higher recall for LULC, indicating fewer missed cases. Cross entropy analysis showed that the ViT model had lower average uncertainty, particularly in the LUAD, Normal, and LUSC classes, compared to ResNet50. This finding suggests that ViT predictions are generally more reliable, though ResNet50 performed better for LULC. The study underscores that accuracy alone is insufficient for model comparison, as cross entropy offers deeper insights into the reliability and confidence of model predictions. The results highlight the importance of incorporating cross entropy alongside traditional metrics for a more comprehensive evaluation of deep learning models in medical image classification, providing a nuanced understanding of their performance and reliability. While the ViT outperformed the CNN-based ResNet50 in lung cancer classification based on cross-entropy values, the performance differences were minor and may not hold clinical significance. Therefore, it may be p
文摘Background: Nosocomial infections have become a major challenge in healthcare facilities as they affect the quality of medical care. Radiological imaging plays a crucial role in medical diagnosis. However, the equipment and accessories used increase the risk of transmission of nosocomial bacteria. Objective: This study aims to reveal the extent and nature of microbiological contamination in four hospital diagnostic imaging departments to determine their potential role in the spread of nosocomial bacteria and to evaluate the effectiveness of routine daily disinfection practices in controlling microorganisms in diagnostic imaging departments. Methods & Results: In each department, swabs were taken from the surfaces of selected parts of the equipment and accessories three times a day (early morning, noon, and evening) for five consecutive days. Bacteria were isolated from 65 swabs (36.1% of all samples). The bacteria were isolated 3 times (4.6%) in the morning, 16 times (24.6%) at midday, and 46 times (70.7%) in the evening. The bacteria isolated were Escherichia coli (isolated 34 times;52.3%), Staphylococcus aureus (20 times;30.8%), Staphylococcus epidermidis (6 times;9.3%), and Klebsiella species (5 times;7.7%). Discussion & Conclusion: Findings demonstrated that radiology equipment and accessories are not free of bacteria and further improvements in the sterilization and disinfection of radiology equipment and accessories are needed to protect staff and patients from nosocomial infections.
基金supported by the National Natural Science Foundation of China(22176163,22106117,52200204)the Natural Science Foundation of Shandong Province(ZR2020QB147,ZR2022QE032)+1 种基金the Young Taishan Scholars Program(tsqn201909082)the Interdisciplinary Basic Frontier Innovation Program of Suzhou Medical College of Soochow University(YXY2304031)。
文摘Harnessing solar energy by photocatalytically converting oxygen and water into high-value-added H_(2)O_(2)is a promising way of alleviating both environmental and energy issues.It is worth noting that suppressing detrimental side reactions,such as the generation of·O_(2)^(-),is a critical approach to enhancing H_(2)O_(2)production.Herein,a 2-fold interpenetrating 3D uranium-organic framework(YTU-W-1)was developed and introduced for photocatalytic H_(2)O_(2)production.The material demonstrates a different photocatalytic mechanism when employing uranyl as an initiator,as compared with the conventional semiconductor photocatalytic pathway involving photo-generated charge carriers.Benefiting from the strong hydrogen abstraction effect of the U≡O·and the direct one-step oxygen reduction pathway,YTU-W-1 exhibits enhanced photocatalytic performance for H_(2)O_(2)production with yield efficiency of 221μmol h^(-1)g^(-1).Furthermore,YTU-W-1 displays a high H_(2)O_(2)selectivity of 68%,confirmed by rotating ring-disk electrode(RRDE)measurement.DFTcalculations were used to elucidate the critical role of uranyl in the photocatalytic oxygen reduction reaction for H_(2)O_(2)production.This research introduces an innovative approach to photo-driven H_(2)O_(2)production,underscoring the potential for heterogeneous catalysts to engage in photocatalytic reactions independently of photogenerated charge carriers.
基金the Materials Science Unit,Radiation Physics Department,National Center for Radiation Research and Technology,Egypt,for financing and supporting this study under the project Nanostructured Magnetic Materials。
文摘This paper addresses the manipulation of structural,morphology,optical and magnetic properties of LiCo0.25Zn0.25Fe2 O4 ferrite via incorporation of different proportions of La^3+at the expense of iron ions using a sol-gel method.The samples were characterized using the X-ray diffraction technique(XRD),Fourier transform infrared(FT-IR)spectroscopy,the energy dispersive X-ray spectra(EDX),inductively coupled plasma optical emission spectroscopy(ICP-OES),high resolution scanning electron microscopy(SEM),Brunauer-Emmett-Teller(BET)surface area analysis,ultraviolet-diffuse reflectance spectroscopy(UV-DRS),and vibrating sample magnetometer(VSM)technique.The Rietveld refinements of the samples indicate that at higher concentrations of La^3+,nanostructures with dual phase,i.e.cubic spinel and orthorhombic LaFeO3 perovskite with space group(Pbnm)appear.Optical studies show that the energy band gap(Eg)of the bare LiCo0.25Zn0.25Fe2 O4 ferrite sample(2.18 eV)reaches up to 2.47 eV at x=0.06 and above this concentration,it drops sharply to 2.00 eV.Although the saturation magnetization and the coercivity of LiCo0.25Zn0.25LaxFe2-xO4 are lower than that of LiCo0.25Zn0.25Fe2 O4 NPs.Overall,the superparamagnetic nature and low values of saturation magnetization and coercivity of LiCo0.25Zn0.25LaxFe2-xO4 NPs are suitable to be applied in transformers core.
基金the National Natural Science Foundation of China(Nos.12004353,11975214,11991071,11905202,and 12174350)Key Laboratory Foundation of the Sciences and Technology on Plasma Physics Laboratory(No.6142A04200103)Independent Scientific Research(No.JCKYS2021212011).
文摘In this paper,we propose a novel stacked laser dielectric acceleration structure.This structure is based on the inverse Cherenkov effect and represented by a parametric design formulation.Compared to existing dielectric laser accelerators relying on the inverse Smith–Purcell effect,the proposed structure provides an extended-duration synchronous acceleration field without requiring the pulse front tilting technique.This advantage significantly reduces the required pulse duration.In addition,the easy to integrate layered structure facilitates cascade acceleration,and simulations have shown that low-energy electron beams can be cascaded through high gradients over extended distances.These practical advantages demonstrate the potential of this new structure for future chip accelerators.
