UNLABELLED: Cyanobacteria are ubiquitous aquatic organisms with a remarkable evolutionary history reaching as far as 1.9 Ga. They play a vital role in ecosystems yet also raise concerns due to their association with harmful algal blooms. Understanding the historical patterns and drivers behind these blooms is crucial for effective ecosystem management. Lake-sediment cores are valuable natural environmental archives, recording the histories of such blooms. Among others, phycocyanin, a pigment specific to cyanobacteria, emerges as a promising biomarker for reconstructing past cyanobacterial bloom events. However, due to the physicochemical properties of phycocyanin, there is no validated method available to extract and measure this pigment from complex sediment matrix. This study explores the applicability of hyperspectral imaging (HSI), a non-destructive technique, as a novel approach for high resolution in-situ detection and quantification of phycocyanin in lake sediments. Our experiments show that phycocyanin can be detected by HSI with an absorption trough at 620 nm (relative absorption band depth, RABD620). We established a semi-quantitative calibration of the spectral index RABD620 by conducting spiking experiments with phycocyanin standard (known phycocyanin mass) on organic-rich and mineral-rich sediments of varying water contents. We also assessed potential interference from chlorophyll a, another photosynthetic pigment, ensuring the reliability of hyperspectral phycocyanin measurements. Our findings demonstrate a significant correlation (R2 ranging from 0.37 to 0.997) between the RABD620 index and associated phycocyanin amounts in organic-rich and minerogenic sediments. This indicates the potential of the spectral index to directly measure in-situ biomarker concentrations on split sediment cores. Although confounding factors such as water and chlorophyll a content can influence the spectral signal, this method offers a rapid and non-destructive approach for studying historical cyanobacterial blooms in sedimentary records. This opens promising grounds for various applications, including ecosystem-health assessment and environmental change monitoring. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10933-024-00350-y.

• Keywords
• Algal blooms, Cyanobacteria, Environmental change, Paleolimnology, Pigments,
• Publication type
• Journal Article MeSH

Tick-borne encephalitis virus (TBEV) is a neurotropic orthoflavivirus that invades the central nervous system, leading to severe neurological manifestations. In this study, we developed a reporter virus comprising TurboGFP-expressing TBEV (tGFP-TBEV) as a versatile tool for advancing TBEV research. The tGFP-TBEV facilitates quantitative measurement of viral replication, enables precise tracking of individual infected cells, and supports high-throughput screening of potential antiviral compounds and virus-neutralization assays. Furthermore, tGFP-TBEV proved effective as a model for studying TBEV infection in rat organotypic cerebellar slices cultured ex vivo and for visualizing TBEV infection in the mouse brain. Using tissue-clearing protocols and light-sheet fluorescence microscopy, we achieved high-resolution, three-dimensional mapping of the TBEV distribution in the mouse brain. This analysis uncovered distinct patterns of TBEV tropism, with infections concentrated in regions associated with neurogenesis, olfactory processing, and specific neuroanatomical pathways. The ability to visualize infection at both the cellular and whole-organ level provides a new tool for detailed investigations into viral tropism, replication, and interactions with host tissues, paving the way for deeper insights into TBEV biology and the pathogenesis of tick-borne encephalitis.

• Keywords
• TBEV, light-sheet microscopy, neurotropism, organotypic cerebellar slices, reporter viruses, tissue clearing,
• MeSH
• Encephalitis, Tick-Borne * virology   MeSH
• Rats MeSH
• Humans MeSH
• Luminescent Proteins genetics   metabolism   MeSH
• Brain * virology   MeSH
• Mice, Inbred C57BL MeSH
• Mice MeSH
• Virus Replication MeSH
• Genes, Reporter MeSH
• Viral Tropism MeSH
• Encephalitis Viruses, Tick-Borne * genetics   physiology   MeSH
• Imaging, Three-Dimensional MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Luminescent Proteins MeSH

Laser-Induced Breakdown Spectroscopy (LIBS) is a widely used technique for elemental analysis. The analysis of the obtained LIBS spectra generally assumes plasma homogeneity. However, using focused laser beams for interrogation, LIBS probes materials on the microscale and is, thus, prone to artefacts from sample heterogeneities on the micrometre scale. An ablation at a material boundary of two matrices may result in a significant inhomogeneity in the plasma plume, which can severely impact the accuracy of quantitative analysis. Since this propagation of the surface morphology into the plasma plume is driven by the plasma expansion, its final impact is strongly pressure dependent. This study examines the influence of varying ambient pressures (7-1000 mbar) on plasma morphology, spectral characteristics, and key plasma properties such as electron number density at a well-defined Cu-Sn boundary, in comparison with the results obtained using homogeneous alloys. Several approaches of plasma imaging with bandpass filters, spectroscopy, and Radon transform-based 3D reconstruction were employed to analyse elemental distribution, signal-to-noise (SNR) and signal-to-background (SBR) ratios, as well as electron number densities. The 3D reconstructions revealed a pronounced plasma asymmetry for the ablation at the material boundary, in contrast to the near-axial symmetry observed for the ablation of homogeneous alloys. At lower pressures, this distinct elemental separation in plasma persisted, while higher pressures led to an increased collisional mixing and homogenization. SNR and SBR were consistently lower for ablation at the boundary compared to homogeneous samples. These findings highlight how boundary ablation contributes to plasma inhomogeneities in LIBS analysis of heterogeneous materials and emphasize the need to account for these effects when using LIBS for elemental mapping of fine heterogeneous structures.

• Keywords
• Ambient pressure effects, Laser-induced breakdown spectroscopy, Material boundaries, Plasma inhomogeneity, Plasma tomography, Radon transform,
• Publication type
• Journal Article MeSH

During hypoxia, tissues are subjected to an inadequate oxygen supply, disrupting the balance needed to maintain normal function. This deficiency can occur due to reduced oxygen delivery caused by impaired blood flow or a decline in the blood's ability to carry oxygen. In tumors, hypoxia and vascularization play crucial roles, shaping their microenvironments and influencing cancer progression, response to treatment and metastatic potential. This chapter provides guidance on the use of non-invasive imaging methods including Positron Emission Tomography and Magnetic Resonance Imaging to study tumor oxygenation in pre-clinical settings. These imaging techniques offer valuable insights into tumor vascularity and oxygen levels, aiding in understanding tumor behavior and treatment effects. For example, PET imaging uses tracers such as [18F]-fluoromisonidazole (FMISO) to visualize hypoxic areas within tumors, while MRI complements this with anatomical and functional images. Although directly assessing tumor hypoxia with MRI remains challenging, techniques like Blood Oxygen Level Dependent (BOLD) and Dynamic Contrast-Enhanced MRI (DCE-MRI) provide valuable information. BOLD can track changes in oxygen levels during oxygen challenges, while DCE-MRI offers real-time access to perfusion and vessel permeability data. Integrating data from these imaging modalities can help assess oxygen supply, refine treatment strategies, enhance therapeutic effectiveness, and ultimately improve patient outcomes.

• Keywords
• BOLD, DCE-MRI, FMISO, Hypoxia, Magnetic resonance imaging, Positron emission tomography, Preclinical, Tumor oxygenation, Vascularity,
• MeSH
• Hypoxia * diagnostic imaging   MeSH
• Oxygen metabolism   MeSH
• Humans MeSH
• Magnetic Resonance Imaging * methods   MeSH
• Misonidazole analogs & derivatives   MeSH
• Mice MeSH
• Tumor Hypoxia MeSH
• Neoplasms * diagnostic imaging   blood supply   pathology   MeSH
• Neovascularization, Pathologic * diagnostic imaging   MeSH
• Positron-Emission Tomography * methods   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• fluoromisonidazole MeSH Browser
• Oxygen MeSH
• Misonidazole MeSH

Infrared spectroscopy of macroscopic samples can be calibrated against reference analysis, such as lipid profiles acquired by gas chromatography, and serve as a fast, low-cost, quantitative analytical method. Calibration of infrared microspectroscopic images against reference data is in general not feasible, and thus spatially resolved quantitative analysis from infrared spectral data has not been possible so far. In this work, we present a deep learning-based calibration transfer method to adapt regression models established for macroscopic infrared spectroscopic data to apply to microscopic pixel spectra of hyperspectral IR images. The calibration transfer is accomplished by transferring microspectroscopic infrared spectra to the domain of macroscopic spectra, which enables the use of models obtained for bulk measurements. This allows us to perform quantitative chemical analysis in the imaging domain based on infrared microspectroscopic measurements. We validate the suggested microcalibration approach on microspectroscopic data of oleaginous filamentous fungi, which is calibrated toward lipid profiles obtained by gas chromatography and measurements of glucosamine content to perform quantitative infrared microspectroscopy.

• Publication type
• Journal Article MeSH

BACKGROUND: This case-control study aimed to quantitatively assess the orbicularis oris muscle (OOM) in children with unilateral cleft lip and palate (UCLP) after primary lip repair using high-resolution ultrasonography, and to compare these measurements with children presenting isolated cleft palate (CP) without lip involvement. METHODS: For this, 12 infants with UCLP who had undergone primary lip repair at 4-5 months of age were examined during subsequent palatoplasty at 9-12 months. They were compared to eight age-matched controls with isolated CP. Using a 22 MHz "hockey stick" transducer under general anaesthesia, muscle thickness (MT), height (MH), and cross-sectional area (CSA) of the OOM were measured on both sides of the upper lip. RESULTS: The cleft side of the study group showed a significantly reduced CSA compared to the non-cleft side (p = 0.05), while MT was lower but not statistically significant. When compared with the control group, the cleft side showed significantly smaller CSA (p = 0.02) and MT (p = 0.05). No significant differences were observed between the non-cleft side and the control group, indicating normal muscle development on the unaffected side. CONCLUSIONS: Ultrasound proved to be a safe, reliable, and accessible tool for evaluating perioral muscle morphology in infants. The findings indicate persistent hypoplasia of the OOM on the cleft side post-repair, while the non-cleft side exhibits regular growth. These results may inform surgical technique selection and underline the potential of ultrasound for longitudinal studies. Future research could further enhance our understanding of muscle development and surgical outcomes in cleft patients.

• Keywords
• Case-control study, Cleft lip, Cleft palate, Facial growth, Muscle morphology, Orbicularis oris muscle, Ultrasonography,
• MeSH
• Infant MeSH
• Humans MeSH
• Facial Muscles * diagnostic imaging   MeSH
• Cleft Palate * surgery   diagnostic imaging   MeSH
• Cleft Lip * surgery   diagnostic imaging   MeSH
• Case-Control Studies MeSH
• Ultrasonography MeSH
• Check Tag
• Infant MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

Recently, multifunctional platinum(IV) complexes designed as prodrugs for the anticancer drug carboplatin and the iron chelator deferoxamine (DFO), each featuring a DFO unit at one axial position and either hemisuccinate or acetate at the other, were developed. As these compounds contain DFO, they hold the potential to be radiolabelled with gallium-68 for molecular imaging and to be recognized by microorganisms, which can utilise DFO as a siderophore-based iron source being taken up by specific siderophore transporters (SITs). Combining this recognition mechanism with a cytotoxic carboplatin core, these compounds could potentially lead to specific antimicrobial activity, particularly against Aspergillus fumigatus (AFU), which causes systemic infections and expresses relevant SITs. The two complexes were radiolabelled with gallium-68 and evaluated for radiochemical purity and protein binding, exhibiting quantitative 68Ga-labeling yields with high radiochemical purity and stability in human serum as well as low protein binding. In vitro uptake assays in AFU and AFU mutants lacking SITs were performed as well as MIC assays for assessment of antifungal activity in comparison to DFO and carboplatin alone. Complexes were also evaluated in in vivo assays including stability studies in healthy mice as well as biodistribution studies and PET imaging in a rat pulmonary aspergillosis model, revealing favourable pharmacokinetics with rapid distribution and a renal excretion pattern with pronounced accumulation in AFU infected lung tissue. However, rapid metabolism of the complexes was observed already 5 min p.i. in serum and urine samples. Overall, this study demonstrates the potential of carboplatin-based Pt(IV)-DFO conjugates for application in infection theranostics.

• Keywords
• Aspergillus fumigatus, Carboplatin, Deferoxamine, Fungal theranostics, Gallium-68, Infection imaging, PET, Pt(IV) complexes,
• Publication type
• Journal Article MeSH

The pH value is one of the most frequently measured chemical parameters, yet developing nanometric sensors capable of accurately mapping pH distribution and dynamics with high spatial and temporal resolution remains a significant challenge. Such sensors are vital for advancing our understanding of numerous physiological and pathological processes. Nanoparticle-based sensors, commonly referred to as nanosensors, represent a promising class of optical sensors, with fluorescence lifetime-based probes offering superior sensitivity and quantitative reliability. However, existing pH nanosensors relying on fluorescence lifetime are challenging to synthesize and often suffer from poor biocompatibility, narrow pH response ranges, low stability, and calibration-dependent performance. Here, we overcome these limitations by introducing a water-dispersible pH nanosensor based on fluorescence lifetime of colloidal carbon dots (CDs) derived via a one-step reaction from a single precursor Rhodamine B. These CDs are biocompatible, non-toxic, and stable in highly acidic/basic conditions, which makes them well-suited for intracellular applications. The intrinsic fluorescence lifetime of these CDs exhibits a pseudo-linear, self-referencing response across exceptionally broad pH range (1-11), driven by pH-induced transformations of their electronic structure occurring during protonation and deprotonation of CD surface. By applying micrometer-resolution, quantitative pH imaging via fluorescence lifetime imaging microscopy, we demonstrate how CDs are preferentially sequestered in lysosomes of human skin fibroblasts, enabling precise quantification of inhibitor-induced pH changes within these organelles. Our findings highlight a significant potential of the CD nanosensors for precise monitoring of lysosomal pH in living cells, offering broad utility in biomedical research and potential studies of pH-associated cellular dysfunction.

• Keywords
• Carbon dots, Fluorescence, Fluorescence lifetime imaging microscopy, Intracellular sensing, pH nanosensor,
• Publication type
• Journal Article MeSH

Among the many applications of additive technologies, their use in drug formulation holds a particularly important place. Numerous studies have been conducted on using various 3D printing techniques to produce both immediate- and modified-release dosage forms. However, the drug release mechanism may vary depending on the manufacturing method and formulation composition. This work aimed to analyze the influence of the 3D printing method used on the mechanism of fluconazole release from prolonged-release tablets. We conducted an analysis of tablets containing 50 mg of fluconazole, produced using two 3D printing techniques: Fused Deposition Modeling (FDM) and Liquid Crystal Display (LCD, classified as one of the Vat Photopolymerization (VPP) methods). Because FDM and VPP techniques build objects in fundamentally different ways, a unique set of excipients was used for each of these methods. For the FDM-printed tablets, poly(vinyl alcohol) was used to control drug release and as the filament-forming polymer. The tablet matrix produced using the VPP method was based on the cross-linked polyethylene glycol diacrylate. Both formulations were characterized by prolonged release of API. Employing surface dissolution imaging and kinetic models, we demonstrated that in the case of FDM-printed tablets, the API release is mainly regulated by the relaxation and gradual decay of the water-soluble polymer. In contrast, the relaxation of the water-insoluble matrix of VPP tablets was negligible. Although the diameter of the VPP tablets increased slightly during the dissolution study, the API release was primarily controlled by the diffusion of fluconazole through the cross-linked polymer.

• Keywords
• Drug release, Fluconazole, Fused deposition modeling, Intrinsic dissolution rate, Kinetic Models, Liquid crystal display, Surface dissolution imaging,
• Publication type
• Journal Article MeSH

AIMS: This systematic review aimed to investigate whether quantitative metrics derived from gaze tracking (GT) outputs during visual field (VF) testing with an automated perimeter could enhance the evaluation of test reliability. MATERIALS AND METHODS: A systematic search of PubMed, Cochrane, LILACS, and IBECS databases, from inception to August 31, 2024, was conducted. RESULTS: Eight studies - four cross-sectional and four cohort - met the inclusion criteria, comprising 8,181 visual field tests from 3,687 patients. The studies were categorized based on testing strategy: SITA Standard, Fast, and Faster. In the SITA Standard group, GT parameters were associated with visual field result reproducibility and the structure-function relationship in glaucoma, but were influenced by ocular surface variables. In the SITA Fast and Faster group, results were mixed: some studies suggested GT metrics could complement conventional reliability parameters, while others concluded that GT quantitative metrics did not offer clinically meaningful insights beyond existing methods. CONCLUSION: GT trace quantification shows promise as an objective reliability parameter for VF testing, particularly within the SITA Standard framework. Advanced image analysis techniques, including artificial intelligence, could facilitate automated GT parameter quantification, streamlining processes and supporting further studies to evaluate their impact on VF data reliability and clinical decision-making.

• Keywords
• automated perimetry, gaze tracking, glaucoma, visual field,
• MeSH
• Glaucoma * diagnosis   physiopathology   MeSH
• Humans MeSH
• Reproducibility of Results MeSH
• Eye-Tracking Technology * MeSH
• Visual Field Tests * methods   MeSH
• Visual Fields * physiology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Systematic Review MeSH