Preclinical evaluation and first-in-human study of [18F]AlF-FAP-NUR for PET imaging cancer-associated fibroblasts.

BACKGROUND: Fibroblast activation protein (FAP) has gained attention as a promising molecular target with potential utility for cancer diagnosis and therapy. [68Ga]Ga-labeled FAP-targeting peptides have been successfully applied to positron emission tomography (PET) imaging of various tumor types. To meet the applicable demand for peptide-based FAP tracers with high patient throughput, we herein report the radiosynthesis, preclinical evaluation, and the first-in-human imaging of a novel [18F]F-labeled FAP-targeting peptide. RESULTS: [18F]AlF-FAP-NUR was automatedly prepared within 45 min with a non-decay corrected radiochemical yield of 18.73 ± 4.25% (n = 3). Compared to [68Ga]Ga-FAP-2286, the [18F]F-labeled peptide demonstrated more rapid, higher levels of cellular uptake and internalization, and lower levels of cellular efflux in HT1080-FAP cells. Micro-PET imaging and biodistribution studies conducted on xenograft mice models revealed a similar distribution pattern between the two tracers. However, [18F]AlF-FAP-NUR demonstrated significantly higher tumor-specific uptake resulting in improved Tumor-Background Ratios (TBRs). In the patients, a significant accumulation of [18F]AlF-FAP-NUR was found in the primary tumor. High uptake of the tracer within the bladder indicated that its major route of excretion was through urine. CONCLUSIONS: Based on the physical imaging properties and longer half-life of [18F]F, [18F]AlF-FAP-NUR exhibited promising characteristics such as enhanced tumor-specific accumulation and elevated TBRs, which made it a viable candidate for further clinical investigation. TRIAL REGISTRATION: www.Chictr.org.cn , ChiCTR2300076976 Retrospectively registered 25 October 2023. at, URL: https://www.chictr.org.cn/showproj.html?proj=206753 .

Levels of trace elements in the blood of chick gulls from the English Channel: Spatial and trophic implications.

Anthropogenic activity has disturbed the natural distribution and circulation of trace elements in the environment. This has led to increased background levels of numerous elements, causing global pollution. In this context, seabirds are relevant bioindicators of environmental contamination. This study focuses on the ecological factors that influence the concentrations of 14 trace elements in the blood of the chicks of three sympatric gull species from the French coast of the English Channel. Between 2015 and 2017, 174 birds were sampled in the industrialised Seine Estuary (in the city of Le Havre and on Ratier Island) and in the remote Chausey Islands, 200 km to the west. We also considered the Se:Hg molar ratio using Hg concentrations in those birds. Ag and V concentrations were below the quantification limit in all cases, while the fraction of non-quantified samples was higher than 30 % for Cd, Cr and Ni. Among the elements quantified in the samples, the lowest concentrations were noted for Co and the highest for Fe, building the following order: Co < Cd < Ni < Mn ≤ Pb < Cr < Hg < Cu < Se < As < Zn < Fe. No unanimous scheme of concentrations among elements, species and sites existed. Similarly, different models were fitted and different factors were significant for different species and elements. We observed the biomagnification of As and the biodilution of Pb. Pb concentrations were also highest in the industrial site in the city of Le Havre. Despite the high proportion of non-quantified samples for Cd, Cr and Ni, we continued to notice higher concentrations in the marine environment of the Chausey Islands. Concentrations of some elements clearly revealed habitat dependence. In some cases the Se:Hg molar ratio was lower than 4, a threshold for diminishing Hg toxicity by Se.

The anabolic response to a ground beef patty and soy-based meat alternative: a randomized controlled trial.

BACKGROUND: Soy-based meat alternatives (SBMA) are becoming increasingly popular, but it is unclear if they have the same anabolic effect on skeletal muscle as animal meat. OBJECTIVES: We aimed to compare the stimulation of skeletal muscle protein synthesis by consumption of 1 or two 4 oz patties of SBMA with 4 oz (80% protein/20% fat) beef. METHODS: The study design was a randomized controlled trial. Participants were aged 18-40 y of age and in good general health with a body mass index (kg/m2) between 20 and 32. Stable isotope tracer methods were used (L-[ring-2H5] phenylalanine, [U-13C9-15N]- tyrosine, and L-[ring-2H4] tyrosine) to quantify the response of muscle protein fractional synthetic rate (FSR) to consumption of a single beef (4 oz), single SBMA (4 oz), or two 4 oz SBMA patties (8 oz). Whole-body rates of protein synthesis, breakdown, and net balance, as well as plasma essential amino acid concentrations, were also measured. RESULTS: The increase above basal in muscle protein FSR following consumption of the 4 oz beef patty (0.020 ± 0.016%/h) was significantly greater than the increase following consumption of 4 oz SBMA (P = 0.021; 0.003 ± 0.010%/h) but not 8 oz SBMA (P = 0.454; 0.013 ± 0.016%/h). The maximal essential amino acid concentration was significantly correlated (P = 0.046; r = 0.411) with the change in muscle FSR from the basal to the postprandial period. In addition, the change in muscle FSR from the basal to postprandial period was significantly correlated (P = 0.046; r = 0.412) with the corresponding change in whole-body protein synthesis. CONCLUSIONS: Consumption of a 4 oz beef patty stimulates muscle and whole-body protein synthesis >4 oz SBMA patty and similarly to 8 oz of SBMA. This trial was registered at clinicaltrials.gov as NCT05197140.

Radiotracers for in situ infection imaging: Experimental considerations for in vitro microbial uptake of gallium-68-labeled siderophores.

In vitro screening of gallium-68(68Ga)-siderophores in pathogens relevant to infections is valuable for determining species specificity, their effect on cell viability, and potential clinical applications. As the recognition and internalization of siderophores relies on the presence of receptor- and/or siderophore-binding proteins, the level of uptake can vary between species. Here, we report in vitro uptake validation in Escherichia coli with its native siderophore, enterobactin (ENT) ([68Ga]Ga-ENT), considering different experimental factors. Compared with other reporting methods of uptake, '% Added dose/109 CFU/mL (% AD/109 CFU/mL),' considering the total viable count, showed a better comparison among microbial species. Later, in vitro screening with [68Ga]Ga-desferrioxamine B (DFO-B) showed high uptake by Staphylococcus aureus and S. epidermidis; moderate uptake by Pseudomonas aeruginosa; poor uptake by E. coli, Candida albicans, and Aspergillus fumigatus; and no uptake by Enterococcus faecalis and C. glabrata. Except for S. epidermidis, [68Ga]Ga-DFO-B did not reduce the cell viability.

Recent advancements in new tracers from first-in-human studies.

Recent advancements in the development of positron emission tomography (PET) tracers have significantly enhanced our ability to image neuroinflammatory processes and neurotransmitter systems, which are vital for understanding and treating neurodegenerative and psychiatric disorders. Similarly, innovative tracers in oncology provide detailed images of the metabolic and molecular characteristics of tumors, which are crucial for tailoring targeted therapies and monitoring responses, including radiotherapy. Notable advancements include programmed death ligand 1 (PD-L1)-targeting agents for lung cancer, prostate-specific membrane antigen-based tracers for prostate cancer, chemokine receptor-targeting agents for hematological malignancies, human epidermal growth factor receptor 2 (HER2)-targeting tracers for various cancers, Claudin 18 based tracers for epithelial tumors, glutamine tracers for colorectal cancer, and ascorbic acid analogs for assessing cancer metabolism and therapy efficacy. Additionally, novel tracers have been developed for non-neurological and non-oncological applications, including adrenal imaging, amyloidosis, and human immunodeficiency virus (HIV) infection. This overview focuses on the newly developed tracers, particularly those used in neurology and oncology.

Neural substrate for the engagement of the ventral visual stream in motor control in the macaque monkey.

The present study aimed to describe the cortical connectivity of a sector located in the ventral bank of the superior temporal sulcus in the macaque (intermediate area TEa and TEm [TEa/m]), which appears to represent the major source of output of the ventral visual stream outside the temporal lobe. The retrograde tracer wheat germ agglutinin was injected in the intermediate TEa/m in four macaque monkeys. The results showed that 58-78% of labeled cells were located within ventral visual stream areas other than the TE complex. Outside the ventral visual stream, there were connections with the memory-related medial temporal area 36 and the parahippocampal cortex, orbitofrontal areas involved in encoding subjective values of stimuli for action selection, and eye- or hand-movement related parietal (LIP, AIP, and SII), prefrontal (12r, 45A, and 45B) areas, and a hand-related dysgranular insula field. Altogether these data provide a solid substrate for the engagement of the ventral visual stream in large scale cortical networks for skeletomotor or oculomotor control. Accordingly, the role of the ventral visual stream could go beyond pure perceptual processes and could be also finalized to the neural mechanisms underlying the control of voluntary motor behavior.

Tower-based profiles of wintertime secondary organic aerosols in the urban boundary layer over Guangzhou.

Secondary organic aerosol (SOA) accounts for a large fraction of fine particulate matter (PM2.5), but the lack of vertical observations of SOA in the urban boundary layer (UBL) limits a comprehensive understanding of its sources and formation mechanisms. In this study, PM2.5 samples were simultaneously collected at 3 m, 118 m, and 488 m on the Canton Tower in Guangzhou during winter. Typical SOA tracers, including oxidation products of isoprene (SOAI), monoterpene (SOAM), sesquiterpene (SOAS), and toluene (ASOA), were investigated alongside meteorological parameters and gaseous/particulate pollutants. Total concentrations of SOA tracers showed an increasing trend with height, with daytime levels exceeding nighttime levels. C5-alkene triols and 2-methylglyceric acid displayed a significant increase with height, potentially affected by nighttime chemistry in the residual layer, determining the overall vertical trend of SOAI tracers. Concentrations of later-generation SOAM (SOAM_S) tracers also increased with height, while those of first-generation SOAM (SOAM_F) tracers decreased, indicating relatively aged SOAM in the upper layers. SOAS and ASOA tracers exhibited higher enhancement under polluted conditions, likely impacted by biomass burning and anthropogenic emissions. The yields of SOAI tracers varied with temperature in the vertical profile. The formation of SOAM_F tracers was negatively correlated with relative humidity, liquid water content, and pH, affecting their vertical distributions. The effect of O3 on SOA formation enhanced significantly with height, influenced by air mass transport, and likely contributed to the higher yields of SOA in the upper layer. However, at ground level, SOA formation was primarily driven by high local emissions of both NOx and volatile organic compounds. We also observed the roles of SO2 in SOA generation, particularly at 118 m. This study demonstrates the vertical diurnal characteristics of SOA tracers in the UBL, highlighting the varying effects of meteorological conditions and anthropogenic pollutants on SOA formation at different heights.

Tracing macroplastics redistribution and fragmentation by tillage translocation.

Soil is polluted with plastic waste from macro to submicron level. Our understanding of macroplastics (> 5 mm) occurrence and behavior has remained comparatively elusive, mainly due to a lack of a tracing mechanism. This study set up a methodology to trace macroplastic displacement, which combined magnetic iron oxide-tagged soil and macroplastic pieces tagged by an adhesive passive radiofrequency identification transponder. By utilizing these techniques, a field study was carried out to analyze the effect of tillage implement and plastic sizes on plastic displacement, to understand the fate of macroplastics in arable land. Results indicated that the displacement of macroplastics did not depend upon plastic sizes but did depend upon the tillage implement used. The mean macroplastics displacement per tillage pass was 0.36 ± 0.25 m with non-inversion chisel tillage and 0.15 ± 0.13 m with inversion disk tillage, which was similar to bulk soil displacement. However, only inversion disk tillage caused fragmentation (41 %) of macroplastics and generated microplastics (< 5 mm). In contrast, both tillage implements drove to similar burial of surface macroplastics into the tilled layer (74 % on average). These results highlight that tillage is a major process for macroplastics fate in arable soils, being one of the first studies to investigate it.

In Vivo Neural Tract Tracing Procedures: Unravelling Neural Hodology Using Fluorescent and Non-fluorescent Neural Tract Tracers, Optogenetic Approach, and Diffusion Tensor Neurotractography Protocols.

Fluorescent and non-fluorescent neural tract tracers enable the investigation of neural pathways in both peripheral and central nervous systems in laboratory animals demonstrating images with high resolution and great anatomic precision. Anterograde and retrograde viral tracers are important cutting-edge tools for neuroanatomical mapping. The optogenetic consists of an advanced alternative for in vivo neural tract tracing procedures, fundamentally considering the possibility to dissect and modulate pathways either exciting or inhibiting neural circuits in laboratory animals. The neurotractography by diffusion tensor imaging in vivo procedures enables the study of neural pathways in humans with reasonable accuracy. Here we describe the procedure of classical anatomic neural tract tracing and modern optogenetic technique performed in anima vili in addition to different diffusion tensor neurotractography performed in anima nobili.

A Novel Luciferase-Based Reporter Gene Technology for Simultaneous Optical and Radionuclide Imaging of Cells.

Multimodality reporter gene imaging combines the sensitivity, resolution and translational potential of two or more signals. The approach has not been widely adopted by the animal imaging community, mainly because its utility in this area is unproven. We developed a new complementation-based reporter gene system where the large component of split NanoLuc luciferase (LgBiT) presented on the surface of cells (TM-LgBiT) interacts with a radiotracer consisting of the high-affinity complementary HiBiT peptide labeled with a radionuclide. Radiotracer uptake could be imaged in mice using SPECT/CT and bioluminescence within two hours of implanting reporter-gene-expressing cells. Imaging data were validated by ex vivo biodistribution studies. Following the demonstration of complementation between the TM-LgBiT protein and HiBiT radiotracer, we validated the use of the technology in the highly specific in vivo multimodal imaging of cells. These findings highlight the potential of this new approach to facilitate the advancement of cell and gene therapies from bench to clinic.

Evaluating Source Complexity in Blended Milk Cheese: Integrated Strontium Isotope and Multi-Elemental Approach to PDO Graviera Naxos.

Graviera Naxos, a renowned cheese with Protected Designation of Origin status, is crafted from a blend of cow, goat, and sheep milk. This study focused on assessing the Sr isotopic and multi-elemental composition of both the processed cheese and its ingredients, as well as the environmental context of Naxos Island, including samples of milk, water, soil, and feed. The objective was to delineate the geochemical signature of Graviera Naxos cheese and to explore the utility of Sr isotopes as indicators of geographic origin. The 87Sr/86Sr values for Graviera Naxos samples ranged from 0.70891 to 0.70952, indicating a relatively narrow range. However, the Sr isotopic signature of milk, heavily influenced by the feed, which originates from geologically distinct areas, does not always accurately reflect the local breeding environment. Multi-elemental analysis revealed variations in milk composition based on type and season; yet, no notable differences were found between raw and pasteurized milk. A mixing model evaluating the contributions of milk, sea salt, and rennet to the cheese's Sr isotopic signature suggested a significant average contribution of 73.1% from sea salt. This study highlights the complexities of linking dairy products with their geographical origins and emphasizes the need for sophisticated geochemical authentication methods.

Delayed and diminished postprandial lactate shuttling in healthy older men and women.

Lactate, a product of glycolysis, is formed under aerobic conditions. Extensive work has shown lactate flux in young and exercising humans; however, the effect of age is not known. We tested the hypothesis that postprandial lactate shuttling (PLS) would be diminished in older adults. We used [3-13C]lactate and [6,6-2H]glucose tracers, an oral glucose tolerance test (OGTT), and arterialized blood sampling to determine postprandial lactate rates of appearance (Ra), disappearance (Rd), and oxidation (Rox) in 15 young (28.1 ± 1.4 yr) and 13 older (70.6 ± 2.4 yr) healthy men and women. In young participants, fasting blood [lactate] (≈0.5 mM) rose after the glucose challenge, peaked at 15 min, dipped to a nadir at 30 min, and rose again peaking at 60 min (≈1.0 mM). Initial responses in lactate Ra of older participants were delayed and diminished until 90 min rising by 0.83 mg·kg-1·min-1. Lactate Rox was higher throughout the entire trial in young participants by a difference of ∼0.5 mg·kg-1·min-1. Initial peaks in lactate Ra and concentration in all volunteers demonstrated the presence of an enteric PLS following an OGTT. Notably, in the systemic, but not enteric, PLS phase, lactate Ra correlated highly with glucose Rd (r2 = 0.92). Correspondence of second peaks in lactate Ra and concentration and glucose Rd shows dependence of lactate Ra on glucose Rd. Although results show both enteric and systemic PLS phases in young and older study cohorts, metabolic responses were delayed and diminished in healthy older individuals.NEW & NOTEWORTHY We used isotope tracers, an oral glucose tolerance test, and arterialized blood sampling to determine postprandial lactate flux rates in healthy young and older men and women. Lactate rates of appearance and oxidation and the lactate-pyruvate exchange were delayed and diminished in both enteric and systemic postprandial lactate shuttle phases in older participants.

Appraisal of amyloidosis imaging practices in the Middle East/North Africa (PYP-MENA).

Aims: Whereas recommendations to optimize performance and yield of cardiac scintigraphy studies with bone-seeking tracers have been published, little is known about real-world adherence to these best practices, especially outside North America and Europe. Accordingly, we described imaging practices with this modality in a sample of nuclear laboratories in the Middle East/North Africa (MENA) region. Methods and results: Laboratories performing radionuclide imaging for cardiac amyloidosis in the MENA region were invited to participate in this study to describe installed camera systems, type and dose of bone-avid tracers used, imaging protocols, and criteria used for study interpretation. Out of 19 invited sites, 10 completed the survey (70% government-run; 90% accredited), sites have been involved with amyloid imaging for a median of 49 months (interquartile range 24-60). The median injected dose was 20 mCi (range 10-25), and PYP was used by 90% of sites in this sample. Planar imaging with single photon emission computed tomography (SPECT) reconstruction was performed at all sites, including seven sites that performed SPECT/CT reconstruction. Lastly, only 50% of sites relied on evidence of myocardial uptake by SPECT to confirm the diagnosis of ATTR cardiomyopathy, while the rest relied on visual assessment and heart/contralateral ratio. Conclusion: This study is the first to describe variation in imaging practices across sites in the MENA region, especially in acquisition protocols and interpretation standards. Eliminating heterogeneities identified by this study will harmonize image interpretation and reporting and will facilitate successful conduct of regional multi-centre studies.

Peptide derived from plant defensins: A promising 68Ga radiolabelled agent for diagnostic of infection foci in PET.

The development of new radiopharmaceuticals for the detection of hidden infection foci has great relevance for early detection and the selection of the correct treatment, particularly in immunosuppressed patients. In that sense, the labelling of antimicrobial peptides (AMPs) that are capable of binding specifically to the pathogenic microorganism which causes the infection, should provide a sufficiently specific agent, able to distinguish an infection from a sterile inflammation. Defensins are particularly interesting molecules with antimicrobial activity, the EcgDf1 defensin was identified from the genome of a Uruguayan native plant, Erythrina crista-galli, the 'Ceibo' tree. Our group has previously reported a synthetic biologically active short analogue EcgDf21 (ERFTGGHCRGFRRRCFCTKHC) successfully labelled with 99mTc. Herein we present a shorter analogue which also preserves the γ-core domain, as a pharmacophore for a potential infection detection agent. This peptide was derivatized with the bifunctional chelating agent 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) through a lysine linker in the amino-terminal group (NOTA-KGHCRGFRRRC) and radiolabelled with 68Ga ([68Ga]Ga-NOTA-K-EcgDf1(10)). The [68Ga]Ga-NOTA-K-EcgDf1(10) labelling procedure rendered a product with high radiochemical purity and stability in the labelling milieu. The Log P value indicated that the complex has a hydrophilic behaviour, confirmed by the biodistribution profile. The [68Ga]Ga-NOTA-K-EcgDf1(10) complex demonstrated specific binding to cultures of Candida albicans and Aspergillus niger. Its biodistribution showed renal elimination and low accumulation in the rest of the body. It was possible to successfully differentiate sterile inflammation from infection by PET images in nude mice with a target/non-target ratio of 3.3 for C. albicans and 3.7 for A. niger, respectively.

Labeling of the serotonergic neuronal circuits emerging from the raphe nuclei via some retrograde tracers.

Serotonin (5-hydroxytryptamine, 5-HT) is a very important neurotransmitter emerging from the raphe nuclei to several brain regions. Serotonergic neuronal connectivity has multiple functions in the brain. In this study, several techniques were used to trace serotonergic neurons in the dorsal raphe (DR) and median raphe (MnR) that project toward the arcuate nucleus of the hypothalamus (Arc), dorsomedial hypothalamic nucleus (DM), lateral hypothalamic area (LH), paraventricular hypothalamic nucleus (PVH), ventromedial hypothalamic nucleus (VMH), fasciola cinereum (FC), and medial habenular nucleus (MHb). Cholera toxin subunit B (CTB), retro-adeno-associated virus (rAAV-CMV-mCherry), glycoprotein-deleted rabies virus (RV-ΔG), and simultaneous microinjection of rAAV2-retro-Cre-tagBFP with AAV-dio-mCherry in C57BL/6 mice were used in this study. In addition, rAAV2-retro-Cre-tagBFP was microinjected into Ai9 mice. Serotonin immunohistochemistry was used for the detection of retrogradely traced serotonergic neurons in the raphe nuclei. The results indicated that rAAV2-retro-Cre-tagBFP microinjection in Ai9 mice was the best method for tracing serotonergic neuron circuits. All of the previously listed nuclei exhibited serotonergic neuronal projections from the DR and MnR, with the exception of the FC, which had very few projections from the DR. The serotonergic neuronal projections were directed toward the Arc by the subpeduncular tegmental (SPTg) nuclei. Moreover, the RV-ΔG tracer revealed monosynaptic non-serotonergic neuronal projections from the DR that were directed toward the Arc. Furthermore, rAAV tracers revealed monosynaptic serotonergic neuronal connections from the raphe nuclei toward Arc. These findings validate the variations in neurotropism among several retrograde tracers. The continued discovery of several novel serotonergic neural circuits is crucial for the future discovery of the functions of these circuits. RESEARCH HIGHLIGHTS: Various kinds of retrograde tracers were microinjected into C57BL/6 and Ai9 mice. The optimum method for characterizing serotonergic neuronal circuits is rAAV2-retro-Cre-tagBFP microinjection in Ai9 mice. The DR, MnR, and SPTg nuclei send monosynaptic serotonergic neuronal projections toward the arcuate nucleus of the hypothalamus. Whole-brain quantification analysis of retrograde-labeled neurons in different brain nuclei following rAAV2-retro-Cre-tagBFP microinjection in the Arc, DM, LH, and VMH is shown. Differential quantitative analysis of median and dorsal raphe serotonergic neurons emerging toward the PVH, DM, LH, Arc, VMH, MHb, and FC is shown.

Linking terrestrial biogeochemical processes and water ages to catchment water quality: A new Damköhler analysis based on coupled modeling of isotope tracers and nitrate dynamics.

Catchment-scale nitrate dynamics involve complex coupling of hydrological transport and biogeochemical transformations, imposing challenges for source control of diffuse pollution. The Damköhler number (Da) offers a dimensionless dual-lens concept that integrates the timescales of exposure and processing, but quantifying both timescales in heterogeneous catchments remains methodologically challenging. Here, we propose a novel spatio-temporal framework for catchment-scale quantification of Da based on the ecohydrological modeling platform EcH2O-iso that coupled isotope-aided water age tracking and nitrate modeling. We examined Da variability of soil denitrification in the heterogeneous Selke catchment (456 km2, central Germany). Results showed that warm-season soil denitrification was of catchment-wide significance (Da >1), while its high spatial variations were co-determined by varying exposure times and removal efficiencies (e.g., channel-connected lowland areas are hotspots). Moreover, Da seasonally shifted from processing-dominance to transport-dominance during the wet-spring season (from >1 to <1), implying important linkages between summer terrestrial denitrification and subsequent winter river water quality. Under the prolonged 2018-2019 droughts, denitrification removal generally reduced, resulting in further accumulation in agricultural soils. Moreover, the space-time responses of Da variability indicated important implications for catchment water quality. The older water in lowland areas exhibited extra risks of groundwater contamination, whilst agricultural areas in the hydrologically responsive uplands became sensitive hotspots for export and river water pollution. Importantly, the lowland pixels intersecting river channels exhibited high removal efficiencies, as well as high resilience to the disturbances (wet-spring Da shifted to >1 under drought conditions). The proposed catchment-wide Da framework is implied by mechanistic modeling, which is transferable across various environmental conditions. This could shed light on understanding of catchment N processes, and thus providing site-specific implications of non-point source pollution controls.

Characterization of biomass burning tracers in particulate matter at 12 sites in China: Significant increase of coal combustion emitted levoglucosan in northern China during winter.

Biomass burning (BB) is the largest contributor to carbonaceous aerosols globally. Specific organic tracers can track BB particles and identify BB types. At present, there is limited information on the composition of BB tracers on a continental scale. In this study, we conducted year-round sampling of particulate matter (PM) at 12 sites in China. Nine BB tracers were measured in PM with aerodynamic diameters <1.1 µm (PM<1.1), in the range of 1.1-3.3 µm (PM1.1-3.3), and > 3.3 µm (PM>3.3). The annual average concentration of these nine BB tracers (∑9 BB tracers) in the total PM was 366 ng m-3 with the majority of levoglucosan (66 %). The concentration of ∑9 BB tracers was higher in northern China than in southern China, especially in winter. ∑9 BB tracers were most enriched in PM<1.1 (50-61 % in mass), followed by PM1.1-3.3 and PM>3.3. The highest concentrations of ∑9 BB tracers were observed in winter, while satellite-recorded fire spots were intensive in autumn and spring. The mismatch of seasonal trends between them indicated that the high levels of BB tracers in winter was not due to open BB. The composition of 4-hydroxybenzoic acid, syringic acid and vanillic acid suggested that the burning of crop residues and softwoods were the major BB types in China. The ratio of levoglucosan to mannosan could neither identify the major BB types in China nor distinguish between BB and coal combustion. Correlation analysis and the PMF model demonstrated that non-BB sources contributed 7 %-58 % to levoglucosan at the 12 sites, with coal combustion being the predominant non-BB source in China, especially in northern urban sites during winter. Our findings suggest that caution should be taken in application of these organic tracers to identify BB types and estimate BB aerosols.

Advancements and challenges in cardiac amyloidosis imaging: A comprehensive review of novel techniques and clinical applications.

Cardiac amyloidosis, characterized by amyloid fibril deposition in the myocardium, leads to restrictive cardiomyopathy and heart failure. This review explores recent advancements in imaging techniques for diagnosing and managing cardiac amyloidosis, highlighting their clinical applications, strengths, and limitations. Echocardiography remains a primary, non-invasive imaging modality but lacks specificity. Cardiac MRI (CMR), with Late Gadolinium Enhancement (LGE) and T1 mapping, offers superior tissue characterization, though at higher costs and limited availability. Scintigraphy with Tc-99m-PYP reliably diagnoses transthyretin (TTR) amyloidosis but is less effective for light chain (AL) amyloidosis, necessitating complementary diagnostics. Amyloid-specific PET tracers, such as florbetapir and flutemetamol, provide precise imaging and quantitative assessment for both TTR and AL amyloidosis. Challenges include differentiating between TTR and AL amyloidosis, early disease detection, and standardizing imaging protocols. Future research should focus on developing novel tracers, integrating multimodality imaging, and leveraging AI to enhance diagnostic accuracy and personalized treatment. Advancements in imaging have improved cardiac amyloidosis management. A multimodal approach, incorporating echocardiography, CMR, scintigraphy, and PET tracers, offers comprehensive assessment. Continued innovation in tracers and AI applications promises further enhancements in diagnosis, early detection, and patient outcomes.

Assessment of soil erosion in the Upper Citarum watershed for sustainability of the Saguling reservoir: unmixing model approach.

The Citarum watershed and the Saguling reservoir are vital natural resources in Indonesia, affecting the livelihood of West Java and the DKI Jakarta population. This study aimed to assess the soil erosion in the Upper Citarum watershed and identify its source. The study used the fallout radionuclide technique, geochemical tracers, and an unmixing model to measure soil erosion and the contribution of suspended sediment sources due to erosion. Soil bulk transects and surface soil were sampled using a coring tool on the Ciwidey and Cisangkuy sub-watersheds. Riverbank and suspended sediment samples were collected from tributaries and rivers. With 137Cs, 40% of the samples had values below the minimum detectable activity, and vice versa for 210Pbex, all samples are detectable. For mitigation, bare land needs to be recovered due to its erosion (25.6 t ha-1 year-1) exceeding the tolerance erosion value (17 t ha-1 year-1). Statistically, Mg and Na were the most appropriate composite tracers for suspended sediment contribution. The unmixing model predicted the sediment contributors from bare land (58%), the riverbank (32.7%), and plantation land (9.3%). Proper land conservation could reduce sediment supply by almost 14.7% and extend the reservoir's life. This is the first study to report the feasibility of the unmixing model in Indonesia.

Fluorescence and tracers in surgery: the coming future.

The revolution that we are seeing in the world of surgery will determine the way we understand surgical approaches in coming years. Since the implementation of minimally invasive surgery, innovations have constantly been developed to allow the laparoscopic approach to go further and be applied to more and more procedures. In recent years, we have been in the middle of another revolutionary era, with robotic surgery, the application of artificial intelligence and image-guided surgery. The latter includes 3D reconstructions for surgical planning, virtual reality, holograms or tracer-guided surgery, where ICG-guided fluorescence has provided a different perspective on surgery. ICG has been used to identify anatomical structures, assess tissue perfusion, and identify tumors or tumor lymphatic drainage. But the most important thing is that this technology has come hand in hand with the potential to develop other types of tracers that will facilitate the identification of tumor cells and ureters, as well as different light beams to identify anatomical structures. These will lead to other types of systems to assess tissue perfusion without the use of tracers, such as hyperspectral imaging. Combined with the upcoming introduction of ICG quantification, these developments represent a real revolution in the surgical world. With the imminent implementation of these technological advances, a review of their clinical application in general surgery is timely, and this review serves that aim.