Shift Of Emission Research Articles

Biphasic lipid extraction from microalgae after PEF-treatment reduces the energy demand of the downstream process

BackgroundThe gradual extrusion of water-soluble intracellular components (such as proteins) from microalgae after pulsed electric field (PEF) treatment is a well-documented phenomenon. This could be utilized in biorefinery applications with lipid extraction taking place after such an ‘incubation’ period, i.e., a post-PEF-treatment step during which the biomass is left undisturbed before any further processing. The goal of this work was to further explore how this incubation could improve lipid extraction.ResultsExperiments were conducted on wet, freshly harvested Auxenochlorella protothecoides, treated with 0.25 or 1.5 MJ/kgDW and incubated for 24 h. Lipid extraction took place with a monophasic ethanol:hexane:water, 1:0.41:0.04 vol/vol/vol mixture with a 75.6 mL solvent per 1 g of dry biomass ratio. The kinetics of the extraction were studied with samples taken between 10 and 1080 min from fresh and incubated biomass. The yields at 10 min were significantly increased with incubation compared to without (31.2% dry weight compared to 1.81%, respectively). The experimental data were fitted with the Patricelli model where extraction occurs in two steps, a rapid washing of immediate available lipids and a slower diffusion one. During Nile-Red staining of microalgae and microscopy imaging, a shift of emission from both GFP and RFP channels to mostly RFP was observed indicating an increase in the polarity of the environment of Nile-Red. These led to an adaption of a biphasic ethanol:hexane:water 1:6:0.4 vol/vol/vol solvent with 37 mL solvent per 1 g of dry biomass ratio which while ineffective on fresh biomass, achieved a 27% dry weight yield from incubated microalgae. The extraction efficiency in the biphasic route was lower compared to the monophasic (i.e., 69% and 95%, respectively). It was compensated however, by the significant solvent reduction (37 mL to 75.6 mL respectively), in particular the ethanol minimization. For the extraction of 1 L lipids, it was estimated that the energy consumption ratio for the biphasic process was 1.6 compared to 9.9 for monophasic, making clearly the most preferential one.ConclusionsThis biphasic approach significantly reduces solvent consumption and the respective energy requirement for solvent recovery. Incubation thus could majorly improve the commercialization prospects of the process.Graphical abstract

Molecular Interactions of the Antimicrobial Peptide Tritrpticin with Mixed Nanoaggregates: A Fluorescence Spectroscopy Study.

Tritrpticin (TRP3) is a peptide belonging to the cathelicidin family and has a broad spectrum of antimicrobial activity. However, this class of biomolecules can be easily degraded in the body, making it necessary to use an efficient transport system. The ability to form stable nanostructures from the interaction of glycyrrhizin saponin with the pluronic polymer F127 was demonstrated, forming mixed biopolymeric micelles, highly promising as drug carriers. The present work sought to understand the physicochemical interaction of the antimicrobial peptide TRP3 with the mixed polymeric micelle made from pluronic F127 and the saponin glycyrrhizin. The interaction of tritrpticin with mixed nanostructured micelles was evaluated through fluorescence spectroscopy and fluorescence quenching with acrylamide. The experiments were performed at room temperature (25 ± 1°C), adopting an excitation wavelength set to 280 nm and emission between 300 and 500 nm, with a slit of 5 nm. The interaction of the cationic peptide tritrpticin with the mixed biopolymeric micelles was observed through the blue shift of the fluorescence emission to shorter wavelengths, proving the change of tryptophan to a more hydrophobic environment. Through the fluorescence suppression technique, it was possible to indicate the location of the peptide in the mixed micelles, proving tritrpticin to be partially inserted inside them. It was concluded that tritrpticin interacted with mixed nanostructured micelles, forming a promising system for biotechnological applications.

A Study of Halide Ion Exchange-Induced Phase Transition in CsPbBr3 Perovskite Quantum Dots for Detecting Chlorinated Volatile Compounds.

The unique optical properties of perovskite quantum dots (PQDs), particularly the tunable photoluminescence (PL) across the visible spectrum, make them a promising tool for chlorinated detection. However, the correlation between the fluorescence emission shift behavior and the interface of phase transformation in PQDs has not been thoroughly explored. In this study, we synthesized CsPbBr3 PQDs via the hot-injection method and demonstrated their ability to detect chlorinated volatile compounds such as HCl and NaOCl through a halide exchange process between the PQDs' solid thin film and the chlorinated vapor phase. This exchange process, which occurs alongside chloride (Cl) and bromine (Br) ion exchange and halide atom rearrangement, leads to sequential structural changes: the initial CsPbBr3 cubic Pm3̅m phase transitions to the CsPb2BrxCl5-x tetragonal I4/mcm phase, which subsequently transforms into the CsPbBrxCl3-x orthorhombic Pnma phase. The detailed exploration of this proposed mechanism during chlorinated vapor detection with CsPbBr3 PQDs thin films, supported by X-ray diffraction (XRD) analysis and PL spectrum over time, revealed high sensitivity to HCl vapor. The limit of detection (LOD) for HCl vapor was determined to be 0.02 ppm in visual recognition and 0.005 ppm via PL spectra. Additionally, the LOD for NaOCl was established at 0.50 ppm, facilitated by the photolysis reaction accelerating the conversion of NaOCl to HCl vapor under UV light irradiation. These insights have enriched our understanding of the mechanisms involved and broadened the potential use of CsPbBr3 PQDs as PL detection probes for chloride ions.

Retrieving the Stability and Practical Performance of Activation-Unstable Mesoporous Zr(IV)-MOF for Highly Efficient Self-Calibrating Acidity Sensing.

The practical applications of activation-unstable mesoporous metal-organic frameworks (MOFs) are often constrained by their structural instability. However, enhancing their stability could unlock valuable functionalities. Herein, we stabilized the otherwise unstable, post-activated structure of a novel mesoporous Zr(IV)-MOF, NKM-809, which uses a pyridine-containing amphiprotic linker (PPTB). We applied two strategies: mixed-linker synthesis and linker installation. In the mixed-linker approach, we incorporated an auxiliary linker, TPTB, which resembles PPTB, during synthesis to improve the framework's stability. In the linker installation approach, we introduced a ditopic carboxylate linker (BPDC) into the coordination-unsaturated sites of NKM-809. These strategies produced stabilized derivatives, named NKM-808.X (X = χPPTB) and NKM-809-BPDC, which exhibit pH-responsive dual-wavelength fluorescence at distinct emission wavelengths. Remarkably, these emissions shift oppositely upon protonation and dissociation, distinguishing them as highly sensitive, self-calibrating acidity sensors. In NKM-809-BPDC, an additional quenching of the linker-emission (419 nm) minimizes inherent interference, enabling integrated quality and lifespan self-monitoring. Theoretical calculations identified transitions between (n, π*) and (π, π*) emission states during the sensing process and highlighted the role of a stable mesoporous network in achieving stronger protonation response. These findings showcase the potential of stabilized mesoporous MOFs for practical applications, alongside valuable insights into strategies for optimizing such materials.

Retrieving the Stability and Practical Performance of Activation‐Unstable Mesoporous Zr(IV)‐MOF for Highly Efficient Self‐Calibrating Acidity Sensing

The practical applications of activation‐unstable mesoporous metal‐organic frameworks (MOFs) are often constrained by their structural instability. However, enhancing their stability could unlock valuable functionalities. Herein, we stabilized the otherwise unstable, post‐activated structure of a novel mesoporous Zr(IV)‐MOF, NKM‐809, which uses a pyridine‐containing amphiprotic linker (PPTB). We applied two strategies: mixed‐linker synthesis and linker installation. In the mixed‐linker approach, we incorporated an auxiliary linker, TPTB, which resembles PPTB, during synthesis to improve the framework's stability. In the linker installation approach, we introduced a ditopic carboxylate linker (BPDC) into the coordination‐unsaturated sites of NKM‐809. These strategies produced stabilized derivatives, named NKM‐808.X (X = χPPTB) and NKM‐809‐BPDC, which exhibit pH‐responsive dual‐wavelength fluorescence at distinct emission wavelengths. Remarkably, these emissions shift oppositely upon protonation and dissociation, distinguishing them as highly sensitive, self‐calibrating acidity sensors. In NKM‐809‐BPDC, an additional quenching of the linker‐emission (419 nm) minimizes inherent interference, enabling integrated quality and lifespan self‐monitoring. Theoretical calculations identified transitions between (n, π*) and (π, π*) emission states during the sensing process and highlighted the role of a stable mesoporous network in achieving stronger protonation response. These findings showcase the potential of stabilized mesoporous MOFs for practical applications, alongside valuable insights into strategies for optimizing such materials.

Harnessing the Sulfur-for-Oxygen Shift: A Magic Bullet for Dynamic Photophysical and Anticancer Activities of Indole-Barbituric Acid Construct.

The development of small molecule-based drugs emerged as a cornerstone of modern drug discovery. Structural activity relationship (SAR) studies in medicinal chemistry are crucial for lead optimization, where a subtle change in the substituent can significantly alter its binding affinity with the biological target. Herein, a highly efficient single-atom substitution (SAS) approach has been developed, where sulfur for oxygen strategy is utilized as a powerful molecular editing technique to identify N-vinyl Indole-thiobarbituric acid (6a) as a novel small molecule-based scaffold with tunable photophysical and antiproliferative activities. A series of NIR-emitting indole-barbituric/thiobarbituric acid conjugates exhibiting aggregation-induced emission (AIE) were prepared, where the replacement of oxygen for sulfur strategy emerged as a magic bullet. On the evaluation of photophysical properties and chemopreventive efficacies, a significant improvement in the absorption and emission profile, cellular uptake, and antiproliferative activity was noted for sulfur counterparts. From the pool of the molecules, the lead molecule 6a unveils a 55 nm emission shift, 142-fold increased anticancer profile, and ~4-fold elevated cellular uptake. Furthermore, the colocalization experiment unravels the nuclear localization of 6a, where it causes severe DNA damage, arrests the cell cycle in the G2/M phase, and leads to the activation of p53-mediated apoptosis.

Zero-Crosstalk Tumor-Targeting Ratiometric Near-Infrared γ-Glutamyltranspeptidase Probe for Fluorescent-Guided Surgical Resection of Orthotopic Hepatic Tumor.

The challenge of "false positive" signals significantly complicates tumor localization and surgical resection, which are pivotal for successful tumor surgeries. Therefore, the development of a method for preoperative tumor localization and intraoperative margin determination holds considerable promise for improving surgical outcomes. In this study, a zero-crosstalk ratiometric tumor-targeting near-infrared (NIR) fluorescent probe was developed for precise cancer diagnosis and intraoperative navigation via NIR fluorescence imaging. This probe integrates a tumor-targeting moiety that selectively homes in on hepatocellular carcinoma cells and exhibits a highly sensitive ratiometric response to γ-glutamyltranspeptidase (GGT), characterized by a substantial emission shift from 830 to 650 nm. This unique NIR ratiometric emission property significantly enhances its effectiveness in early diagnosis and imaging-guided surgery resection. Furthermore, this zero-crosstalk probe successfully monitors GGT activity in blood, cells, and in vivo, endowing its potential for early cancer diagnosis in the clinic. Due to its efficient targeting and sensitive in situ response to GGT in both subcutaneous tumors and orthotopic hepatic tumors, the probe exhibits accurate detection capability for hepatic tumors. Additionally, by leveraging zero-crosstalk ratiometric NIR fluorescence imaging, this tumor-targeting probe can serve as a sprayable tool for delineating tumor margins with precision, thereby furnishing real-time intraoperative imaging guidance during tumor resection surgery.

Influence pathways of covalent and non-covalent interactions on the stability of deamidated gliadin-tannic acid-based Pickering emulsions.

This study aimed to elucidate the pathways through which covalent and non-covalent interactions between deamidated gliadin (DG) and tannic acid (TA) on influence the stability of Pickering emulsions. The interactions induced protein unfolding, as evidenced by increased ultraviolet absorption and a red shift in fluorescence emission. DG-TA composite nanoparticles effectively stabilized high internal phase emulsions, whereas DG nanoparticles alone did not. Covalent DG-TA nanoparticle stabilized Pickering emulsions (C-DGTAE) retained a consistent mean droplet size after 30 d of storage. Lipid hydroperoxide and malondialdehyde levels in C-DGTAE and N-DGTAE were reduced by 59.1%-69.5% and 38.9%-44.4%, respectively. Furthermore, the retention of β-carotene in the emulsions was significantly enhanced. All emulsions exhibited elastic behavior, characterized by higher G' than G″. Notably, N-DGTAE demonstrated the highest apparent viscosity, G' and G″, attributed to the connected nanoparticles around the droplets. Confocal laser scanning microscopy revealed that C-DGTAE droplets possessed the thickest layer, corroborated by the highest interfacial nanoparticle content of 76% and an interfacial thickness of 441nm. These findings suggest that covalent interactions enhance the interfacial nanoparticle layer, while non-covalent interactions promote nanoparticle networking, providing valuable insights for optimizing the stability of Pickering emulsions.

Quantum dot-to-dye-based fluorescent ratiometric immunoassay for GFAP: a biomarker for ischaemic stroke and glioblastoma multiforme.

Ischaemic stroke and glioma, as leading causes of mortality and long-term disability, pose critical challenges to healthcare systems, necessitating innovative approaches to enable early and cost-effective diagnosis for timely intervention. Glial fibrillary acidic protein (GFAP), an astrocyte-produced protein, is highly responsive to both ischaemic stroke and glioblastoma multiforme, with its levels correlating to the extent of brain damage. In this study, we present the development of an immunoassay probe for the ratiometric fluorescent detection of glial fibrillary acidic protein (GFAP), employing a monoclonal GFAP antibody-conjugated silicon quantum dots (Ab@SiQDs) and rhodamine B dye (RhB)-based immunoprobe. The developed probe exhibited a fluorescence emission shift from 580 nm to 530 nm in response to GFAP, demonstrating a linear detection range from 31.15 pg mL-1 to 243 pg mL-1, with a limit of detection of 0.7 pg mL-1. Additionally, the immunoprobe showed high selectivity for GFAP, effectively discriminating it from other potential interfering biomolecules and ions. The probe was also capable of detecting GFAP in spiked serum samples, achieving a recovery rate ranging from 83% to 111%. Notably, a cost-effective paper strip assay was developed, offering significant potential for the visual detection of GFAP under ultraviolet illumination.

Push-pull effect - how to effectively control photoinduced intramolecular charge transfer processes in rhenium(I) chromophores with ligands of D-A or D-π-A structure.

Over the last five decades, diimine rhenium(I) tricarbonyl complexes have been extensively investigated due to their remarkable and widely tuned photophysical properties. These systems are regarded as attractive targets for design functional luminescent materials and performing fundamental studies of photoinduced processes in transition metal complexes. This review summarizes the latest developments concerning Re(I) tricarbonyl complexes bearing donor-acceptor (D-A) and donor-π-acceptor (D-π-A) ligands. Such compounds can be treated as bichromophoric systems with two close-lying excited states, metal-to-ligand charge transfer (MLCT) and intraligand-charge-transfer (ILCT). A role of ILCT transitions in controlling photobehaviour was discussed for Re(I) tricarbonyls with six different diimine cores decorated by various electron-rich amine, sulphur-based and π-conjugated aryl groups. It was evidenced that this approach is an effective tool for enhancement of the visible absorptivity, bathochromic emission shift and significant prolongation of the excited-state, opening up new possibilities in the development of more efficient materials and expand the range of their applications.

First‐principles simulations of the fluorescence modulation of a COX‐2‐specific fluorogenic probe upon protein dimerization for cancer discrimination

AbstractCyclooxygenase‐2 (COX‐2) plays a crucial role in inflammation and has been implicated in cancer development. Understanding the behavior of COX‐2 in different cellular contexts is essential for developing targeted therapeutic strategies. In this study, we investigate the fluorescence spectrum of a fluorogenic probe, NANQ‐IMC6, when bound to the active site of human COX‐2 in both its monomeric and homodimeric forms. We employ a multiscale first‐principles simulation protocol that combines ground state MM‐MD simulations with multiple excited state adiabatic QM/MM Born‐Oppenheimer MD simulations based on linear response TD‐DFT, which allows to account for protein heterogeneity effects on excited‐state properties. Emission is then estimated from polarizable embedding TD‐DFT QM/MMPol calculations. Our findings indicate that the emission shift arises from dimerization of the highly overexpressed COX‐2 in cancer tissues, in contrast to the monomer structure present in inflammatory lesions and in normal cells with constitutive COX‐2. This spectral shift is linked to changes in specific protein–probe interactions upon dimerization due to changes in the environment, whereas steric effects related to modulation of the NANQ geometry by the protein scaffold are found to be minor. This research paves the way for detailed investigations on the impact of environment structural transitions on the spectral properties of fluorogenic probes. Moreover, the fact that COX‐2 exists as homodimer just in cancer tissues, but as monomer elsewhere, gives novel hints for therapeutical avenues to fight cancer and contributes to the development of drugs targeted to COX‐2 dimer in cancer, but without affecting constitutive COX‐2, thus minimizing off‐target effects.

Fe-Doped 4-Aminophenylacetylene-Derived Red Emissive Polymer Carbon Dots: Synthesis and Anti-Counterfeiting Applications.

Phenylacetylene derivatives serve as typical monomers for polyaddition reactions. In this study, we present a straightforward one-step protocol for synthesizing polyacetylene P0 (undoped), P0.09 (doped with 0.09 mg/mL Fe3+), and carbonized polymer dots CPDs-Fe (doped with 0.13 mg/mL Fe3+) using 4-aminophenylacetylene and varying concentrations of Fe3+ via solvothermal addition and carbonization (EtOH, 200 °C, 6 h, high-pressure reactor). The resulting P0, P0.09, and CPDs-Fe exhibit green, light red, and red luminescence with maxima at 514 nm (quantum yield, QY = 20.08%), 623 nm (QY = 8.17%), and 645 nm (QY = 9.03%), respectively. Structural and morphological analyses indicate that altering the doping concentration of Fe3+ and the reaction temperature results in a transformation from the amorphous, short-conjugated structure of P0 to the low-crystallinity, fibrous, and longer-conjugated structure of P0.09, and finally to the highly crystalline, elliptical, and largest-conjugated structure of CPDs-Fe, respectively. These structural and morphological changes lead to a shift in emission from green in P0 to red in CPDs-Fe. Density functional theory (DFT) calculations on the CPDs-Fe substructures reveal that coordination with Fe3+/Fe2+ and the elongation of the alkene chain enhances conjugation interactions, reduces the band gap, and consequently induces a red shift in emission. CPDs-Fe can be incorporated into poly(vinyl alcohol) (PVA) to form a CPDs-Fe@PVA composite film, which exhibits dual-mode fluorescence and room-temperature phosphorescence with tunable lifetimes, making it suitable for anti-counterfeiting applications based on phosphorescence. This study provides a strategy for converting 4-aminophenylacetylene into tunable CPDs with tailored structural and photonic properties, offering potential applications in fluorescence and phosphorescence-based technologies.

Pressure‐Engineered Through‐Space Conjugation for Precise Control of Clusteroluminescence

AbstractClusteroluminogens (CLgens) represent an innovative class of nonconjugated luminophores that address the limitations of conventional π‐conjugated molecules. Different from the through‐bond conjugation mechanism in π‐conjugated luminophores, through‐space conjugation (TSC) plays dominant roles in CLgens. However, precisely controlling TSC to customize the optical properties of CLgens remains a significant challenge. This work proposes a novel strategy of high pressure to engineer TSC within tetraphenylalkanes (TPAs)‐based CLgens at molecular level. High‐pressure exploration enables accurate manipulation of clusteroluminescence and elucidates the intrinsic structure–property relationships involved. Upon initial compression, the predominant molecular distortions marked by increased interfacial angles between benzene rings diminish TSC, resulting in anomalous hypochromatic shift in emission. Subsequently, considerable structural contraction enhances TSC and suppresses molecular motion, resulting in a pronouncedly enhanced and bathochromic‐shifted emission. Notably, a series of TPAs‐based CLgens exhibit intense white‐light emission upon pressure release, attributed to irreversible structural distortion and destruction. This study not only advances the understanding of CLgens, but also underscores the crucial structural factors for effective TSC control, paving the way for establishing new photophysical theories for aggregate science.

Achieving Thermally Stable YAl3-xGax(BO3)4:Cr3+ Near-Infrared Emitting Phosphors via Chemical Substitution for Plant Growth LEDs.

Indoor plant cultivation has been receiving increased attention due to concerns about sustainable agricultural production. Phosphor-converted light-emitting diodes (pc-LEDs) offer substantial promise as lighting solutions for regulating plant growth. However, the quest for high-performance phosphors with precise responsiveness to far-red phytochromes poses a challenge. Our study proposes a chemical substitution strategy to develop near-infrared (NIR) phosphors, YAl3-xGax(BO3)4:Cr3+. Benefiting from Ga3+ replacement of Al3+, a red shift in the NIR emission of YAl3-xGax(BO3)4:Cr3+ is realized to attain a good alignment with far-red phytochrome absorption centering at 730 nm. The optimized YAl2.5Ga0.5(BO3)4:Cr3+ exhibits a favorable quantum yield of 71.8% and robust thermal stability of 101.0%@423 K, owing to local structural distortion and thermal repopulation caused by Ga3+ incorporation. The fabricated pc-LED combined with the phosphor yields an NIR output power of 40.9 mW and a photoelectric conversion efficiency of 15.4% at 100 mA. Plant growth experiments demonstrate that under NIR illumination from the devices, the average lengths of pea roots and stems gain 127 and 225% promotion, respectively, further highlighting the potential of YAl2.5Ga0.5(BO3)4:Cr3+ phosphors for applications in plant cultivation.

Pressure-Engineered Through-Space Conjugation for Precise Control of Clusteroluminescence.

Clusteroluminogens (CLgens) represent an innovative class of nonconjugated luminophores that address the limitations of conventional π-conjugated molecules. Different from the through-bond conjugation mechanism in π-conjugated luminophores, through-space conjugation (TSC) plays dominant roles in CLgens. However, precisely controlling TSC to customize the optical properties of CLgens remains a significant challenge. This work proposes a novel strategy of high pressure to engineer TSC within tetraphenylalkanes (TPAs)-based CLgens at molecular level. High-pressure exploration enables accurate manipulation of clusteroluminescence and elucidates the intrinsic structure-property relationships involved. Upon initial compression, the predominant molecular distortions marked by increased interfacial angles between benzene rings diminish TSC, resulting in anomalous hypochromatic shift in emission. Subsequently, considerable structural contraction enhances TSC and suppresses molecular motion, resulting in a pronouncedly enhanced and bathochromic-shifted emission. Notably, a series of TPAs-based CLgens exhibit intense white-light emission upon pressure release, attributed to irreversible structural distortion and destruction. This study not only advances the understanding of CLgens, but also underscores the crucial structural factors for effective TSC control, paving the way for establishing new photophysical theories for aggregate science.

Encapsulation-induced hypsochromic shift of emission properties from a cationic Ir(III) complex in a hydrogen-bonded organic cage: A theoretical study.

Encapsulation of coordination complexes within the confined spaces of self-assembled hosts is an effective method for creating supramolecular assemblies with distinct chemical and physical properties. Recent studies with calix-resorcin[4]arene hydrogen-bonded hexameric capsules revealed that encapsulated metal complexes exhibit enhanced and blue-shifted photoluminescence compared to their unencapsulated forms. The photophysical change has been hypothetically attributed to encapsulation-induced confinement, which isolates the metal complex from the solvent, suppressing stabilization of the excited state of the guest by solvent reorganization and structural relaxation, and altering the local environment, such as solvent polarity and viscosity, around the guest. In this study, density-functional theory calculations were conducted to explore how encapsulation affects the photophysical properties of a cationic iridium complex within a hydrogen-bonded hexameric capsule. The encapsulation-induced emission shift was analyzed by separating it into three factors: suppression of solvent reorganization, suppression of structural relaxation of the complex, and electronic interactions between the complex and the capsule. The findings indicate that the photoluminescence modulation is driven by the electronic interaction between the host and guest, which affects the energy levels of the molecular orbitals involved in the T1 excited state and the suppression of excited-state structural relaxation of the Ir complex due to the presence of the host. This study advances our understanding of the photophysical dynamics of coordination complexes within the confined spaces of hexameric capsules, providing a valuable approach for tuning the excited state properties of guest molecules.

Satellite Data and Machine Learning for Benchmarking Methane Concentrations in the Canadian Dairy Industry

Amid escalating climate change concerns, methane—a greenhouse gas with a global warming potential far exceeding that of carbon dioxide—demands urgent attention. The Canadian dairy industry significantly contributes to methane emissions through cattle enteric fermentation and manure management practices. Precise benchmarking of these emissions is critical for developing effective mitigation strategies. This study ingeniously integrates eight years of Sentinel-5P satellite data with advanced machine learning techniques to establish a methane concentration benchmark and predict future emission trends in the Canadian dairy sector. By meticulously analyzing weekly methane concentration data from 575 dairy farms and 384 dairy processors, we uncovered intriguing patterns: methane levels peak during autumn, and Ontario exhibits the highest concentrations among all provinces. The COVID-19 pandemic introduced unexpected shifts in methane emissions due to altered production methods and disrupted supply chains. Our Long Short-Term Memory (LSTM) neural network model adeptly captures methane concentration trends, providing a powerful tool for planning and reducing emissions from dairy operations. This pioneering approach not only demonstrates the untapped potential of combining satellite data with machine learning for environmental monitoring but also paves the way for informed emission reduction strategies in the dairy industry. Future endeavors will focus on enhancing satellite data accuracy, integrating more granular farm and processor variables, and refining machine learning models to bolster prediction precision.

The influence of coordination mode differences on the structural diversity and fluorescence properties of Zn(II)/Cd(II) Schiff base complexes

Four metal complexes 1 : Zn2Cl2L2, 2 : Zn2(CH3OO)2L2·MeCN, 3 : Zn(NO3)2HL, 4 : CdCl2HL were obtained by coordinating the flexible Schiff‐base ligand 4‐amino‐N'‐(di(pyridin‐2‐yl)methylene)benzohydrazide (abbreviated as HL) with the Zn(II) and Cd(II). X‐ray single crystal diffraction confirms that the four complexes 1‐4 employ two different coordination modes. Moreover, the structures of complexes 1 and 2 are accompanied by deproton behavior, and these structural differences not only increase the fluorescence quantum yield but also produce a red shift in fluorescence emission. TD‐DFT calculations confirm that these performance changes are related to the coordination mode and coordination environment. This work not only construct the four fluorescent complexes, but also further deepen the understanding of the structure‐activity relationship between the structure of the complexes and the fluorescence properties.

Effects of monosaccharides glycation on structural characteristics and functional properties of coconut protein isolate based on molecular docking

The study examined the impact of glycation with five-carbon and six-carbon monosaccharides on the structure and physicochemical properties of coconut protein isolate (CPI). Compared to native CPI, CPI/monosaccharide complexes exhibited higher absorbance ratios (A294/A420) and glycation degrees. Structural analysis revealed an increase in disordered structures (β-turn and random coil), a blue shift in fluorescence emission, and elevated UV absorbance, indicating protein unfolding and exposure of hydrophobic groups. Glycation significantly enhanced CPI's solubility, emulsifying capacity, oil holding capacity, and thermal stability. Molecular docking simulations emphasized the importance of hydrogen bonding in complex formation. These findings provide insights into protein-carbohydrate interactions, offering potential for diverse industrial applications and guiding future research.

A Novel Colon-Targeting Ratiometric Probe with Large Emission Shift for Imaging Peroxynitrite in Ulcerative Colitis.

Ulcerative colitis (UC) is an inflammatory disease that leads to the overexpression of peroxynitrite (ONOO-). Up to now, it has been a challenge to design a colon-targeted fluorescent probe with a large emission shift that can detect and image ONOO- in UC mice. Here, a fluorophore (pyran-coumarin) is linked with cholic acid to develop a colon-targeted fluorescent probe (CPC) for the detection of ONOO-. The fluorescent probe showed strong near-infrared emission at 725 nm. After reacting with ONOO-, it can be observed that the fluorescence intensity at 725 nm decreases obviously, and the signal at 490 nm increases clearly with an obvious emission shift (235 nm). This response mechanism causes the probe to have good sensitivity and selectivity. Additionally, the probe CPC shows good targeting ability for the cells with overexpressingTGR5 receptors and displays good results for detecting exogenous and endogenous ONOO- in the cells. More importantly, the probe CPC can be especially assembled in the colon site to distinguish normal and UC mice and provide significant information for the diagnosis of UC.