Imaging Strategies Research Articles

Rationale and design of the multicentric randomized EVAOLD trial: evaluation of a strategy guided by imaging versus routine invasive strategy in elderly patients with ischemia

BackgroundThe management of myocardial infarction without ST segment elevation (NSTEMI) in elderly patients remains challenging, in particular the benefit/risk balance of routine revascularization remains uncertain. Study designEVAOLD is s a multicenter, prospective, open-label trial with 2 parallel arms in NSTEMI patients ≥ 80 years of age. The aim of the trial is to test whether a strategy of selective invasive management guided by ischemia stress imaging (IMG group) will be non-inferior in preventing Major Adverse Cardiac and Cerebrovascular Events (MACCE, ie all-cause death, non-fatal myocardial infarction, non-fatal stroke) rates at 1 year compared with a routine invasive strategy (INV Group). Geriatric assessment and cost- effectiveness analysis will also be performed. A sample size of 1756 patients (assuming a 10% rate of patients lost to follow-up) is needed to show non-inferiority with 80% power. Non-inferiority based on exponential survival curves will be declared if the upper limit of the one-sided 97.5% confidence interval for the hazard ratio is lower than 1.24, corresponding to a non-inferiority margin of 7% in absolute difference and an event rate of 40% in the INV group. ConclusionEVAOLD is a nationwide, prospective, open-label trial testing the non-inferiority of a strategy of selective invasive management guided by ischemia stress imaging versus routine invasive strategy in elderly NSTEMI patients. ClinicalTrials.gov Identifier: NCT03289728

Innovative optical imaging strategies for monitoring immunotherapy in the tumor microenvironments.

The tumor microenvironment (TME) plays a critical role in cancer progression and response to immunotherapy. Immunotherapy targeting the immune system has emerged as a promising treatment modality, but challenges in understanding the TME limit its efficacy. Optical imaging strategies offer noninvasive, real-time insights into the interactions between immune cells and the TME. This review assesses the progress of optical imaging technologies in monitoring immunotherapy within the TME and explores their potential applications in clinical trials and personalized cancer treatment. This is a comprehensive literature review based on the advances in optical imaging modalities including fluorescence imaging (FLI), bioluminescence imaging (BLI), and photoacoustic imaging (PAI). These modalities were analyzed for their capacity to provide high-resolution, real-time imaging of immune cell dynamics, tumor vasculature, and other critical components of the TME. Optical imaging techniques have shown significant potential in tracking immune cell infiltration, assessing immune checkpoint inhibitors, and visualizing drug delivery within the TME. Technologies like FLI and BLI are pivotal in tracking immune responses in preclinical models, while PAI provides functional imaging with deeper tissue penetration. The integration of these modalities with immunotherapy holds promise for improving treatment monitoring and outcomes. Optical imaging is a powerful tool for understanding the complexities of the TME and optimizing immunotherapy. Further advancements in imaging technologies, combined with nanomaterial-based approaches, could pave the way for enhanced diagnostic accuracy and therapeutic efficacy in cancer treatment.

Reply to “Enhancing breast imaging strategies: The role of ChatGPT in optimizing screening pathways”

Reply to “Enhancing breast imaging strategies: The role of ChatGPT in optimizing screening pathways”

In vivo imaging of alkaline phosphatase in lipid metabolic diseases with a photoacoustic probe

Lipid metabolic diseases have become an important challenge to global public health. Along with lifestyle changes, the incidence of obesity, diabetes and other metabolic syndromes is on the rise, and the number of patients with fatty liver disease is also increasing. Therefore, it is particularly important to develop effective lipid imaging strategies to monitor and manage fatty liver disease. Herein, based on the essential role of alkaline phosphatase (ALP) in both AS and OB, in vivo imaging of ALP was achieved in two lipid metabolic diseases models with a photoacoustic (PA) probe phosphorylated hemicyanine (P-Hcy). After being triggered by ALP, P-Hcy responded in different modalities including absorbance, fluorescence and, most significantly, PA-reporting. Notably, the PA signal showed the reliable linear correlation to the ALP level within the range of 0–800 U/L. The probe P-Hcy exhibited the advantages including high sensitivity, high selectivity, and steadiness in required biological conditions. The intracellular imaging results ensured that P-Hcy could visualize the ALP level in the foam cells induced from mouse mononuclear macrophages. In the healthy and lipid metabolic diseases models, P-Hcy was able to distinguish well between a lipid metabolic disease model and a healthy mouse model by photoacoustic imaging. By combining the ALP detection with P-Hcy in PA/fluorescence modality and traditional techniques such as blood biochemical testing and immunohistochemically staining, more potential strategy to accurately diagnose lipid metabolic diseases in the pre-clinical trials might be developed in future.

Comprehensive risk management and safety strategies in radiation use in medical imaging

Radiation use in medical imaging, while essential for accurate diagnosis and treatment planning, poses inherent risks that require comprehensive risk management and safety strategies. This review discusses the critical aspects of managing these risks in clinical settings, focusing on patient safety, staff protection, and environmental considerations. A major challenge in medical imaging is balancing the diagnostic benefits of radiation against potential harms, particularly in sensitive populations such as children and pregnant women. Comprehensive risk management involves implementing dose optimization techniques, such as using low-dose imaging protocols and advanced technologies like iterative reconstruction and artificial intelligence (AI) algorithms, which enhance image quality while minimizing exposure. Additionally, ensuring the safety of healthcare staff is paramount. This requires adherence to strict safety protocols, including the use of personal protective equipment (PPE), regular monitoring of radiation levels, and continuous education on safe radiation practices. Institutional policies must also address the proper maintenance and calibration of imaging equipment to prevent unnecessary exposure due to equipment malfunction or improper use. Environmental safety is another critical component, necessitating the safe disposal of radioactive materials and the adoption of energy-efficient technologies to reduce the environmental footprint of medical imaging. Regulatory compliance with international safety standards, such as those set by the International Commission on Radiological Protection (ICRP) and national bodies, is essential for ensuring consistent safety practices across healthcare institutions. Future directions in radiation safety include the integration of digital health technologies to monitor and manage radiation exposure more effectively, and ongoing research into novel imaging techniques that could further reduce radiation risks. Collaboration between healthcare providers, researchers, and policymakers is crucial to advancing safety standards and improving risk management strategies in medical imaging. This review highlights the importance of a comprehensive approach to managing radiation risks in medical imaging, emphasizing the need for continuous innovation, education, and policy support to protect patients, healthcare workers, and the environment.

The Influence of Brand Image, Price Perception, and Local Wisdom-Based Promotional on Buyer's Decision

This study analyzes the influence of brand image, price perception, and local wisdom-based promotional strategies on the purchasing decisions for Tebo Riski Danang batik in Tebo Regency, Jambi Province. Tebo batik is unique, and Rumah Batik Riski Danang stands out by producing and marketing it, highlighting the region's history and distinctiveness. The research employed a quantitative method with questionnaires distributed to 255 respondents in Tebo Tengah District. The analysis included validity, reliability, correlation, and multiple linear regression. The findings revealed that brand image negatively impacts purchasing decisions, while price perception has a positive influence. However, the promotional strategy does not significantly affect purchasing decisions. Simultaneously, the three variables together significantly influence purchasing decisions. Brand image, price perception, and promotional strategy explain 41.4% of the variation in purchasing decisions, with other factors accounting for the remaining 58.6%. In conclusion, brand image and price perception are crucial in shaping purchasing decisions for Tebo Riski Danang batik, while the promotional strategy has no significant impact.

Development of mKate3/HaloTag7 (JFX650) and CFP/YFP Dual-Fluorescence (or Förster) Resonance Energy Transfer Pairs for Visualizing Dual-Molecular Activity.

Although several imaging strategies for dual fluorescence (or Förster) resonance energy transfer (FRET) biosensors have been reported, their implementation is challenging because of the limited performance of fluorescent proteins and the spectral overlap of FRET biosensors. These processes often require additional data calibration to eliminate artifacts. Many CFP/YFP FRET biosensors have been developed. In this study, we introduced the mKate3/HT7(JFX650) FRET pair, which effectively formed two pairs of FRET pairs for dual-FRET imaging when combined with the CFP/YFP FRET pair. The FRET donor mKate3 exhibited higher brightness than its predecessor mKate. The FRET acceptor, HT7(JFX650), is a HaloTag7 protein covalently conjugated with a far-red JFX650-THL ligand. The pair comprising mKate3 and HT7(JFX650) represents an excellent FRET dyad, exhibiting a high FRET efficiency ratio. To use the FRET pair for dual FRET biosensor imaging, we constructed PKA and K+ biosensors based on the mKate3/HT7(JFX650) FRET pair. These biosensors can be used along with CFP/YFP biosensors to simultaneously detect the responses of intracellular PKA/Src, PKA/Ca2+, and K+/Ca2+ under different stimuli. The findings revealed that dual FRET biosensors, which are based on the combination of CFP/YFP and mKate3/HT7 (JFX650), exhibit adequate compatibility and can be used to visualize multiple molecular activities in a live cell.

Urethral tissue characterization using multiparametric ultrasound imaging

A decrease in urethral closure pressure is one of the primary causes of stress urinary incontinence in women. Atrophy of the urethral muscles is a primary factor in the 15 % age-related decline in urethral closure pressure per decade. Incontinence not only affects the well-being of women but is also a leading cause of nursing home admission. The objective of this research was to develop a noninvasive test to assess urethral tissue microenvironmental changes using multiparametric ultrasound (mpUS) imaging technique. Transperineal B-scan ultrasound (US) data were captured using clinical scanners equipped with curvilinear or linear transducers. Imaging was performed on volunteers from our institution medical center (n = 15, 22 to 76 y.o.) during Valsalva maneuvers. After expert delineation of the region of interest in each frame, the central axis of the urethra was automatically defined to determine the angle between the urethra and the US beam for further analysis. By integrating angle-dependent backscatter with radiomic texture feature analysis, a mpUS technique was developed to identify biomarkers that reflect subtle microstructural changes expected within the urethral tissue. The process was repeated when the urethra and US beam were at a fixed angle. Texture selection was conducted for both angle-dependent and angle-independent results to remove redundancies. Ultimately, a distinct biomarker was derived using a random forest regression model to compute the urethra score based on features selected from both processes. Angle-dependent backscatter analysis shows that the calculated slope of US mean image intensity decreased by 0.89 (±0.31) % annually, consistent with the expected atrophic disorganization of urethral tissue structure and the associated reduction in urethral closure pressure with age. Additionally, textural analysis performed at a specific angle (i.e., 40 degrees) revealed changes in gray level nonuniformity, skewness, and correlation by 0.08 (±0.04) %, −2.16 (±1.14) %, and −0.32 (±0.35) % per year, respectively. The urethra score was ultimately determined by combining data selected from both angle-dependent and angle-independent analysis strategies using a random forest regression model with age, yielding an R2 value of 0.96 and a p-value less than 0.001. The proposed mpUS tissue characterization technique not only holds promise for guiding future urethral tissue characterization studies without the need for tissue biopsies or invasive functional testing but also aims to minimize observer-induced variability. By leveraging mpUS imaging strategies that account for angle dependence, it provides more accurate assessments. Notably, the urethra score, calculated from US images that reflect tissue microstructural changes, serves as a potential biomarker providing clinicians with deeper insight into urethral tissue function and may aid in diagnosing and managing related conditions while helping to determine the causes of incontinence.

Abstract C016: Optical Techniques to Democratize Intravital Quantification of Metabolic Heterogeneity

Abstract Since metabolic and vascular adaptations are essential for tumor cell survival, a technique capable of tracking metabolic heterogeneity at both the bulk tumor and cellular scales over extended timelines is necessary. To address this technological need, we have developed a multi-scale optical microscope relying on exogenous fluorescent reporters for dynamic spatiotemporal imaging of major metabolic pathways in vivo. This microscope utilizes a low-cost CMOS detector and LEDs for excitation to enable fluorescence microscopy in resource-limited settings. Here, we implement our system to assess changes in bulk tumor and cellular metabolic heterogeneity as vasculature is perturbed. 4T1 breast tumor-bearing mice were treated with combretastatin A-1 (a vascular disruptor), implanted with window chambers, and temporally imaged (n=5/group). Fluorescence imaging and Gabor filter/Djikstra segmentation approaches enabled metabolic and vascular analyses, respectively. We demonstrated the system’s ability to acquire co-registered images of vasculature, morphology, and distinct metabolic endpoints reporting on glucose uptake, fatty acid uptake, and mitochondrial metabolism at both wide-field and high resolutions. At 12 hours post-treatment, the tumors’ metabolism shifted from mitochondrial respiration to glycolysis in avascular regions. Further, we report a higher average vascular density in untreated versus treated mice at 108 hours post-treatment (p<0.05, Kolmogorov-Smirnov test). On exploring the relationship between metabolic activity and vasculature, regions with high local tortuosity in the untreated group exhibited a higher reliance on fatty acid uptake than high tortuosity regions in the treatment group, indicating these cells’ reliance on fatty acids within a complex vascular network. Our multiplexed imaging strategy enables the quantification of tumor metabolism and vasculature over multiple length scales, which could be leveraged to study adaptations following clinical therapies. Citation Format: Enakshi Sunassee. Optical Techniques to Democratize Intravital Quantification of Metabolic Heterogeneity [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C016.

Seizure outcome in surgically treated pediatric gangliogliomas and dysembryoplastic neuroepitheliomas according to imaging and resection strategies

PurposeImaging and resection strategies for pediatric gangliogliomas (GG) and dysembryoplastic neuroepitheliomas (DNET) presenting with epilepsy were retrospectively analyzed in a consecutive institutional series of surgically treated patients. MethodsTwenty-two children (median 8 years, 3–18 years) presented with seizures for 30 months median (14–55.2 months) due to a histologically verified GG/DNET. ResultsThere were 20 GG and 2 DNT, 68 % located temporal, 32 % extra-temporal. Seizure history was significantly longer in temporal cases (38 versus 14 months median, p < 0.01). MRI contrast enhancement was present in 50 % and methionine (MET) positron emission tomography (PET) uptake in 70 % (standard uptake values (SUVs) 2.92 mean, from 1.6 to 6.4). 27 % had glucose PET hypometabolism. Primarily, in temporal GG, ECoG (electrocorticography) -guided lesionectomies were performed in 87 % and antero-mesial temporal lobe resections (AMTLR) in 13 %, whereas in extra-temporal GG/DNETs, lesionectomies were performed in 100 %. ILAE Class 1 seizure outcome was primarily achieved in 73 % of the temporal cases, and was increased to 93 % by performing six repeat surgeries using AMTLR. Extratemporal patients experienced ILAE Class 1 seizure outcomes in 86 % without additional surgeries, although harboring significantly more residual tumor (p < 0.005, mean follow-up 28 months). ConclusionIn children, MET PET imaging for suspected GG is proposed preoperatively showing a high diagnostic sensitivity and an option to delineate the lesions for navigated resection, whereas MRI contrast behavior was of no differential diagnostic use. As a surgical strategy we propose primarily lesionectomies for extratemporal but AMTLR for temporal GG respecting eloquent brain areas.

Patellar Sleeve Fracture: An Update of Literature

Patellar sleeve fractures, though relatively rare, present unique challenges in diagnosis and management. This review aims to provide a comprehensive overview of the current understanding of patellar sleeve fractures, focusing on their epidemiology, clinical presentation, imaging, and management strategies. Epidemiologically, these fractures are uncommon, representing approximately 1% of all fractures in pediatric patients, yet they account for 50% of all patella fractures in this population. They predominantly affect adolescents, with a peak incidence around 12.7 years of age, and are more common in boys, occurring at a ratio of 3 to 5:1. Understanding these demographic patterns is crucial for early recognition and appropriate management. Clinically, patellar sleeve fractures typically present with the sudden onset of severe pain, often associated with explosive activities such as jumping. However, diagnosis can be challenging, particularly in cases with minimal displacement or where alternative muscle groups compensate for the injury. Differential diagnosis is essential, and clinicians should be vigilant for signs such as palpable gaps at the lower pole of the patella and patella alta. Imaging modalities play a vital role in diagnosis, with plain X-rays often revealing no bony damage. Ultrasonography may offer a cost-effective alternative, especially in cases where radiographic findings are inconclusive. Advanced imaging techniques such as MRI can assist in characterizing the extent of the injury and assessing for associated complications. Management strategies encompass a spectrum of approaches, ranging from conservative measures such as immobilization and physical therapy to surgical interventions, including open reduction and internal fixation or arthroscopic surgery. The choice of treatment depends on various factors, including the fracture pattern, displacement, patient age, activity level, and associated injuries. Despite advancements in diagnosis and treatment, the optimal management of patellar sleeve fractures remains a clinical challenge. Further research is warranted to elucidate optimal algorithms for diagnosis and treatment, with the ultimate goal of improving outcomes and reducing the risk of long-term complications associated with this rare but clinically significant knee injury.

Full-waveform ultrasonic imaging for bone

Abstract This paper suggests a full-waveform ultrasonic imaging strategy for bone. A novel forward wavefield propagation is performed in the frequency-domain. To improve the efficiency of full-waveform inversion bone imaging, all relative computations are also conducted in the frequency-domain. Additionally, a conjugate gradient algorithm is employed in the inversion procedure to accelerate the reconstruction of the bone acoustic velocity. Eventually, numerical experiments on different bone models are carried out to demonstrate the effectiveness of explored imaging strategy.

Трансформація готельно-ресторанного обслуговування в умовах цифровізації

The article is dedicated to exploring the unique aspects and primary trends in the digital transformation of hotel and restaurant services. It has been demonstrated that the increasing competition, the drive for operational efficiency, and the enhancement of customer service quality are key drivers for the adoption of digital technologies in the hotel and restaurant industry. Understanding and meeting evolving consumer expectations, such as the preference for online ordering, swift transaction processing, and personalized service, is also crucial in this digital shift. It has been established that under the influence of digitalization processes in all spheres of life, modern restaurants are actively implementing digital technologies, which allow the automation and optimization of most operational processes. Despite the growth of digital activity, domestic restaurants have yet to achieve the same pace of digitalization as other industries or similar enterprises in specific global contexts. This is evidenced by the insufficiently high share of electronic sales (about 12%) and the low implementation of BIG DATA technologies (8.9%) in the management and analytics of hotel and restaurant businesses. Research has revealed that several digitalization tools are being rapidly integrated into restaurant services, including digital marketing, the development of digital food delivery platforms (FoodTech), automated management systems, and interactive technologies. The digital transformation of business processes in food service establishments not only enables swift adaptation to market changes but also significantly enhances the competitiveness of the restaurant business. It is argued that the effectiveness of hotel and restaurant service digitalization processes depends on the choice of the most optimal balance between software tools and digital instruments and the authentic characteristics of each restaurant, the target customer base, their tastes and preferences, and the image strategy of positioning in the food service market. Keywords: digitalization, digital tools, hotel and restaurant business, automated management systems, digital transformation of hotel and restaurant services, digital marketing.

Prevalence and characteristics of transthyretin amyloid cardiomyopathy in hypertrophic cardiomyopathy.

Recognition of transthyretin amyloid cardiomyopathy is increasing due to advances in cardiac imaging and diagnostic strategies, but questions remain regarding disease frequency and characteristics. We examined the prevalence and characteristics of transthyretin amyloid cardiomyopathy in older patients with hypertrophic cardiomyopathy of unascertained aetiology. TTRACK was a multicentre, non-interventional, cross-sectional epidemiologic study funded by Pfizer and conducted in 20 hospitals and medical centres in 11 countries (NCT03842163). Eligible patients were aged ≥50years, had hypertrophic cardiomyopathy (maximal end-diastolic left ventricular wall thickness ≥15mm on echocardiogram) without an identified genetic or alternative origin at study enrolment, and underwent 99mTechnetium bone scintigraphy, with or without single photon emission computed tomography (SPECT). Cardiac-versus-bone uptake on scans was visually scored from 0 to 3 (Perugini scoring). Patients with grades 1-3 underwent monoclonal protein and laboratory testing and transthyretin (TTR) gene sequencing. Of 766 eligible patients, 691 (90.2%) had scintigraphy alone and 75 (9.8%) scintigraphy plus SPECT. Two hundred and eight patients (27.2%) had grade 2 or 3 cardiac uptake on scintigraphy; 144 (18.8%) had grade 2 or 3 cardiac uptake and no evidence of plasma cell dyscrasia and were diagnosed with transthyretin amyloid cardiomyopathy. Of patients with transthyretin amyloid cardiomyopathy, 11 (7.6%) had a pathogenic TTR gene variant and 34 (23.8%), 74 (51.7%), and 35 (24.5%) had New York Heart Association class I, II, and III/IV heart failure (HF) symptoms, respectively. Clinical and laboratory diagnostic characteristics were observed in ≥90% of patients with transthyretin amyloid cardiomyopathy. The characteristics most strongly associated with transthyretin amyloid cardiomyopathy on multivariable analysis were carpal tunnel syndrome (odds ratio [OR] 54.3; P<0.0001) and male sex (OR 7.9; P<0.0001). In the TTRACK study, almost one in five patients ≥50years of age with hypertrophic cardiomyopathy had transthyretin amyloid cardiomyopathy. Greater awareness of the frequency and characteristics of transthyretin amyloid cardiomyopathy in older patients with hypertrophic cardiomyopathy are needed to help improve early detection of this debilitating but treatable disease.

Microglia cannibalism and efferocytosis leads to shorter lifespans of developmental microglia.

The overproduction of cells and subsequent production of debris is a universal principle of neurodevelopment. Here we show an additional feature of the developing nervous system that causes neural debris - promoted by the sacrificial nature of embryonic microglia that irreversibly become phagocytic after clearing other neural debris. Described as long-lived, microglia colonize the embryonic brain and persist into adulthood. Using transgenic zebrafish to investigate the microglia debris during brain construction, we identified that unlike other neural cell-types that die in developmental stages after they have expanded, necroptosis-dependent microglial debris is prevalent when microglia are expanding in the zebrafish brain. Time-lapse imaging of microglia demonstrates that this debris is cannibalized by other microglia. To investigate features that promote microglia death and cannibalism, we used time-lapse imaging and fate-mapping strategies to track the lifespan of individual developmental microglia. These approaches revealed that instead of embryonic microglia being long-lived cells that completely digest their phagocytic debris, once most developmental microglia in zebrafish become phagocytic they eventually die, including ones that are cannibalistic. These results establish a paradox -- which we tested by increasing neural debris and manipulating phagocytosis -- that once most microglia in the embryo become phagocytic, they die, create debris and then are cannibalized by other microglia, resulting in more phagocytic microglia that are destined to die.

Adaptive sampling strategy for Fourier single-pixel imaging

Fourier single-pixel imaging is a technique that utilizes Fourier bases as illumination patterns to capture images. While the use of orthogonal bases enhances the imaging quality compared with other methods of single pixel imaging, the slow imaging speed has hindered its broader application. Acquiring only low-frequency Fourier coefficients enables capturing a significant portion of image information at low sampling ratio, thereby enhancing imaging speed. Nevertheless, truncating frequencies results in a loss of image detail and a decrease in picture quality. To address this challenge, this paper introduces an adaptive sampling strategy for Fourier single-pixel imaging, allowing for customized sampling distributions for each specific object. The sampling distribution is dynamically generated based on the acquired Fourier coefficients during the acquisition process, eliminating the need for prior information. Through extensive simulations and experimental analysis, this approach has demonstrated its ability to capture more complex image details at equivalent sampling ratios.

Graph-based cell pattern recognition for merging the multi-modal optical microscopic image of neurons

A deep understanding of neuron structure and function is crucial for elucidating brain mechanisms, diagnosing and treating diseases. Optical microscopy, pivotal in neuroscience, illuminates neuronal shapes, projections, and electrical activities. To explore the projection of specific functional neurons, scientists have been developing optical-based multimodal imaging strategies to simultaneously capture dynamic in vivo signals and static ex vivo structures from the same neuron. However, the original position of neurons is highly susceptible to displacement during ex vivo imaging, presenting a significant challenge for integrating multimodal information at the single-neuron level. This study introduces a graph-model-based approach for cell image matching, facilitating precise and automated pairing of sparsely labeled neurons across different optical microscopic images. It has been shown that utilizing neuron distribution as a matching feature can mitigate modal differences, the high-order graph model can address scale inconsistency, and the nonlinear iteration can resolve discrepancies in neuron density. This strategy was applied to the connectivity study of the mouse visual cortex, performing cell matching between the two-photon calcium image and the HD-fMOST brain-wide anatomical image sets. Experimental results demonstrate 96.67% precision, 85.29% recall rate, and 90.63% F1 Score, comparable to expert technicians. This study builds a bridge between functional and structural imaging, offering crucial technical support for neuron classification and circuitry analysis.

Understanding the impact of tourist behavior change on travel agencies in developing countries: Strategies for enhancing the tourist experience

The study investigates the impact of tourist behavior change on travel agencies in developing countries, with a focus on strategies for enhancing the tourist experience. The research aims to identify the main factors influencing tourist purchasing behavior and understand their relationship with the customer experience. Data were collected from 368 experienced tourists in Ho Chi Minh City and Hanoi, Vietnam, using a combination of convenience and random sampling. Partial Least Squares Structural Equation modeling (PLS-SEM) is employed to analyze the research model. The findings confirm that product quality, product price, brand image, and marketing strategy significantly influence tourist purchasing behavior. Importantly, the results highlight the indirect effect of these factors on purchasing behavior, mediated through customer experience. It suggests that enhancing the customer experience is a crucial aspect of influencing tourist purchasing decisions. Based on these findings, industry managers and travel agents in developing countries should prioritize enhancing customer experience and building a strong brand through personalized services, digital integration, and active social media engagement. Implementing dynamic pricing strategies and targeted marketing campaigns that address safety concerns and highlight local experiences are crucial for competitiveness and attracting travelers post-crisis. Future research should explore the long-term effects of these strategies on travel agency performance and adapt the model to specific regional contexts. By adopting these multifaceted approaches, travel agencies in developing countries can enhance their competitiveness and better navigate the changing tourist behavior in the post-crisis era.

Analysis of Guangzhou city image perception based on weibo text data (2019–2023)

With the popularization of smart mobile terminals and social media, a large amount of data containing textual information about the city has been generated on social media platforms, covering all areas of the city. This provides a new way for the study of comprehensive perception of city image. In the Internet era, users express their opinions about cities through social media platforms (e.g., Sina Weibo), and mining this information helps to understand the image of cities on mainstream social media and to target positive images to improve the competitiveness of the city's image. In this paper, 370,000 microblog messages related to “Guangzhou City” between 2019 and 2023 are collected using web crawler technology, and three typical text analysis methods are adopted: Term Frequency-Inverse Document Frequency (TF-IDF), Latent Dirichlet Allocation (LDA), and Sentiment Analysis (SnowNLP), to understand the characteristics of Guangzhou city image. gain an in-depth understanding of Guangzhou's urban image characteristics. The study shows that extensive data analysis methods based on text mining can perceive the dynamics and trends of the city in a timely manner, refine the characteristics of Guangzhou's urban image, and propose communication strategies for Guangzhou's image. This study aims to mine Guangzhou's urban image presented on Weibo, provide data support for relevant departments in China and Guangzhou to formulate communication strategies, and provide references for other cities to manage their urban image.

Bioorthogonal Diels-Alder Click Chemistry-Based Pretargeted PET Imaging Strategy for Monitoring Programmed Death-Ligand 1 Expression.

The development of antibody tracers for positron emission tomography (PET) imaging enables real-time monitoring of tumor expression of programmed cell death ligand 1 (PD-L1) in vivo, aiming to facilitate the selection of immunotherapy responders. However, the slow pharmacokinetics of the antibodies in vivo limits their applications in PET imaging with commonly used radionuclides with short half-lives. In this study, we developed a pretargeted PET imaging strategy based on Diels-Alder (IEDDA) click chemistry to overcome these limitations. Atezolizumab and durvalumab, the most commonly used PD-L1 antibodies in cancer immunotherapy, were selected and compared in the development of the pretargeted PET imaging strategy. Fluorine-18-labeled derivatives of methyl tetrazine ([18F]Tz, [18F]PEG6-Tz, and [18F]PEG12-Tz) were tested in biodistribution and PET imaging of A549-PDL1 xenografts (PD-L1 positive) pretargeted with the trans-cyclooctene (TCO)-functionalized atezolizumab/durvalumab. The biodistribution and imaging results indicated that atezolizumab-TCO/[18F]PEG12-Tz was more suitable for pretargeted PET imaging strategy, and the optimal interval time was 48 h after atezolizumab-TCO administration, where the atezolizumab-TCO/[18F]PEG12-Tz pretargeted approach clearly delineated the A549-PDL1 tumor with a tumor-to-muscle ratio of 5.33, while the ratios are 3.39 and 2.39 for durvalumab/[18F]PEG12-Tz and mock-pretargeting controls, respectively. In conclusion, a pretargeted 18F-immuno-PET imaging technology was successfully established on atezolizumab. The high-contrast PET images of the A549-PDL1 tumor models demonstrate that the pretargeting strategy incorporating short-lived fluorine-18 is viable in identifying tumors with high PD-L1 expression, marking this strategy as a potential candidate for further clinical translation.