Ideal Source Research Articles

Artificial Tertiary Lymphoid Structures: Exploring Mesenchymal Stromal Cells as a Platform for Immune Niche Formation

Constructing artificial tertiary lymphoid structures (TLSs) opens new avenues for advancing cancer immunotherapy and personalized medicine by creating controllable immune niches. Mesenchymal stromal cells (MSCs) offer an ideal stromal source for such constructs, given their potent immunomodulatory abilities and accessibility. In this study, we explored the potential of adipose-derived MSCs to adopt TLS-supportive phenotypes and facilitate lymphocyte organization. Single-cell RNA sequencing revealed a distinct subpopulation of MSCs expressing key fibroblastic reticular cell (FRC)-associated markers, including IL-7, PDPN, and IL-15, though lacking follicular dendritic cell (FDC) markers. TNF-α stimulation, but not LTα2β1, further enhanced FRC marker expression (IL-7, PDPN, and ICAM1). Notably, in 3D spheroid co-culture with lymphocytes, MSCs upregulated additional FRC markers, specifically CCL21. Upon implantation into adipose tissue, MSC-lymphocyte organoids maintained structural integrity and showed extensive T-cell infiltration and partial vascularization after 15 days in vivo, although organized B-cell follicles and FDC markers were still lacking. These findings highlight MSCs’ intrinsic ability to adopt an FRC-like phenotype that supports T-cell and HEV organization, suggesting that further optimization, including genetic modification, may be needed to achieve an FDC phenotype and replicate the full architectural and functional complexity of TLSs.

HoloGaussian Digital Twin: Reconstructing 3D Scenes with Gaussian Splatting for Tabletop Hologram Visualization of Real Environments

Several studies have explored the use of hologram technology in architecture and urban design, demonstrating its feasibility. Holograms can represent 3D spatial data and offer an immersive experience, potentially replacing traditional methods such as physical 3D and offering a promising alternative to mixed-reality display technologies. Holograms can visualize realistic scenes such as buildings, cityscapes, and landscapes using the novel view synthesis technique. This study examines the suitability of spatial data collected through the Gaussian splatting method for tabletop hologram visualization. Recent advancements in Gaussian splatting algorithms allow for real-time spatial data collection of a higher quality compared to photogrammetry and neural radiance fields. Both hologram visualization and Gaussian splatting share similarities in that they recreate 3D scenes without the need for mesh reconstruction. In this research, unmanned aerial vehicle-acquired primary image data were processed for 3D reconstruction using Gaussian splatting techniques and subsequently visualized through holographic displays. Two experimental environments were used, namely, a building and a university campus. As a result, 3D Gaussian data have proven to be an ideal spatial data source for hologram visualization, offering new possibilities for real-time motion holograms of real environments and digital twins.

Characterization of novel bio-plasticizer from Cissus quadrangularis linn. stem: A sustainable and cleaner material for futuristic applications

There is also an increase in demand for plasticizers derived from natural resources, which are biodegradable. In search of novel bio-plasticizers, Cissus quadrangularis linn. (CQL) plant identified serves as an ideal source for plasticizer from natural sources. In this context, plasticizer is extracted from Cissus quandrangularis linn. stem that are biodegradable and biocompatible. This research paper presents the extraction and characterization of plasticizers derived from Cissus quadrangularis linn. (CQL) stem as a substitute for synthetic plasticizers. Bio-Plasticizers from CQL stem are extracted through chemical processes: amination, alkalization, filtration and surface catalysis. Further to identify its plastic nature, different characterization techniques such as FTIR, Thermal analysis, XRD, density, micrographs from SEM, chemical composition from EDX surface texture from AFM are conducted. TGA results convey that the Cissus quadrangularis linn. plasticizers (CQLP) are thermally stable upto 2230 C and displays a lower glass transition temperature of 58.170 C and these results accomplish the desired thermal properties. Crystalline properties of CQLP are found to be good with values of Crystalline Index 72.95 % and Crystalline Size 2.32 nm and these results displays the crystalline nature of isolated plasticizers. Surface texture of CQLP identified from AFM is smooth and uniform with lower roughness values across horizontal and vertical directions. Results of characterization studies accomplishes that novel CQLP are biodegradable, compatible and possess good plasticizing effect. This research investigation shows that these novel CQLP proves as a reliable alternative to synthetic plasticizers.

Conditional Immortalization Using SV40 Large T Antigen and Its Effects on Induced Pluripotent Stem Cell Differentiation Toward Retinal Progenitor Cells.

Current treatments for retinal degenerative diseases are limited and cell replacement therapies, in tandem with a supportive biomaterial scaffold, serve as a promising emerging option. However, the development and in vitro testing of these therapies require large quantities of human retinal progenitor cells (RPCs) to thoroughly assess the impact of material properties, culture conditions, and surgical parameters on cell survival and fate to refine and optimize this approach. Although induced pluripotent stem cells (iPSCs) are an ideal cell source for human RPC derivation, large-scale production is resource-intensive and requires specialized expertise. In this study, our objective was to address this barrier by creating conditional, Tet-On SV40-T immortalized RPCs derived from human iPSCs. In our approach, we employ the Tet-On system to conditionally immortalize RPCs by inducing a SV40 large T (SV40-T) antigen, a gene known to influence cell cycle regulation and differentiation. We transduced human iPSCs with the Tet-On SV40-T system and analyzed their proliferation and RPC differentiation capabilities in the presence and absence of doxycycline (a tetracycline class of antibiotics). Our results revealed that while SV40-T immortalization increased cell proliferation, it adversely impacted the expression of crucial RPC markers (PAX6, SOX2, CHX10), leading to a significant loss of RPC identity and multipotency. This de-differentiation was irreversible, even after removing doxycycline, indicating permanent alterations in differentiation potential. Overall, this study highlights the challenges associated with generating and maintaining an immortal human RPC cell line, particularly with respect to balancing proliferation and differentiation. Our findings prompt further research into optimizing conditional immortalization techniques, culture conditions, and proliferation timing to maintain the integrity and functional characteristics of RPCs. Such advancements are crucial for reducing labor and costs associated with in vitro testing of therapeutics as we work toward the development of improved stem cell-based interventions for retinal disease.

Application of a sEMG hand motion recognition method based on variational mode decomposition and ReliefF algorithm in rehabilitation medicine.

Hand motion intention recognition has been considered as one of the crucial research fields for prosthetic control and rehabilitation medicine. In recent years, surface electromyogram (sEMG) signals that directly reflect human motion information are ideal input sources for prosthetic control and rehabilitation. However, how to effectively extract components from sEMG signals containing abundant limb movement information to improve the accuracy of hand recognition still is a difficult problem. To achieve this goal, this paper proposes a novel hand motion recognition method based on variational mode decomposition (VMD) and ReliefF. First, VMD is used to decompose the sEMG signal into multiple variational mode functions (VMFs). To efficiently extract the intrinsic components of the sEMG, the recognition performance of different numbers of VMFs is evaluated. Then, four features representing hand motion intentions are extracted from the VMFs to form the initial feature space. Next, the ReliefF algorithm is used to remove redundant features from the feature space. In order to select a feature space that can effectively reflect the intention of hand movements, the hand movement recognition performance of 8 low-dimensional feature spaces is evaluated. Finally, three machine learning methods are used to recognize hand movements. The proposed method was tested on the sEMG for Basic Hand movements Data Set and achieved an average accuracy of 99.14%. Compared with existing research, the proposed method achieves better hand motion recognition performance, indicating the potential for healthcare and rehabilitation applications.

Genotyping <em> Escherichia coli </em> O157:H7 strains isolated from cattle and small ruminants in Fars province (Iran) using Enterobacterial Repetitive Intergenic Consensus PCR Analysis

Genotyping <em> Escherichia coli </em> O157:H7 strains isolated from cattle and small ruminants in Fars province (Iran) using Enterobacterial Repetitive Intergenic Consensus PCR Analysis

Targeted Treatment of Myocardial Infarction by Macrophage Membrane Coated with Resveratrol Nanoparticles.

Myocardial infarction (MI) is characterized by rapid onset and high mortality. Due to the complexity of its pathological process, targeted therapy for MI has been a long-standing challenge. Macrophages, as immune cells, selectively accumulate in the infarct area after MI. This inherent targeting ability, coupled with excellent immune evasion capabilities, makes macrophages an ideal source for targeted delivery to damaged myocardium as a biomimetic delivery carrier. Therefore, in this work, we aimed to develop biomimetic nanoparticles for specific targeted drug delivery to efficiently treat MI. Using cell membrane-coated nanotechnology, we prepared resveratrol-loaded nanoparticles (RESNPs) using poly(lactic-co-glycolic acid) (PLGA) nanoparticles, and then coated the surface of RESNPs with macrophage membranes to prepare biomimetic nanoparticles MM/RESNPs. We then described the physical properties of MM/RESNPs, and their targeting, therapeutic effects, and safety were evaluated in a MI mouse model. The results show that MM/RESNPs exhibited good biocompatibility and could effectively target damaged myocardial sites. MM/RESNPs were found to considerably improve cardiac function and reduce the infarct size in MI mice. Furthermore, MM/RESNPs demonstrated good biosafety after long-term administration. Macrophage membrane-coated biomimetic nanoparticles (MM/RESNPs) exhibit excellent nanoperformance and biosafety, enabling targeted drug delivery and achieving safe and effective treatment for MI.

Study on characterization of flame propagation of spontaneous ignition caused by high-pressure hydrogen leakage

As an ideal energy source, hydrogen is highly susceptible to spontaneous ignition once leaked, which is an urgent issue that needs to be addressed. Based on the shock tube model, this paper investigates flame propagation under various pressures, tube lengths, and diameters by employing the LES approach and a detailed hydrogen/air combustion mechanism. The results indicate that within the tube, the ignition kernels gradually evolve into tulip flames when specific conditions are satisfied. As pressure and tube length increase, the likelihood of forming a complete flame rises significantly; with the increase of tube diameter, the flame front is flatter and the flame intensity is more uniformly distributed. Furthermore, this paper develops a model to predict the formation of a complete flame: Pb/Pa=570.64(L/D)−0.6. Outside the tube, once the intact flame passes out of the tube and evolves into a jet flame, structures such as flame envelopes and jet vortices will appear. Higher release pressures make it more difficult for the flame to propagate steadily, whereas increasing tube length and diameter promotes combustion and sustains the flame outside the tube.

Effects of fish meal replacement with composite proteins source on growth performance, antioxidant capacity and swim bladder quality of chu’s croaker (Nibea coibor)

Collagen, as a commercial functional protein, is widely applied in food, cosmetics, biomedicine and other industries, and swim bladder is regarded as an ideal source of raw materials due to its rich collagen content. Chu’s croaker (Nibea coibor), as an economical fish that can produce high-grade swim bladder, is popularly farmed, however, its high fishmeal demand limits the development of the feed industry. Therefore, it is worth thinking about how to reduce the use of fish meal without affecting the swim bladder quality. Given that, an 8-week feeding trial was conducted to investigate the effects of fish meal partially replaced (0.0%, 5.0%, 10.0%, 15.0%, 20.0%) with composite proteins (CPs, consisted of corn protein meal and hydrolyzed feather meal) on growth, antioxidant capacity and swim bladder quality (texture and collagen deposition) of chu’s croaker. Results showed that although growth performance decrease with the increase of CPs’ replacement level, it did not compromise the swim bladder quality. Specifically, 5% - 10% CPs did not affect the growth significantly, but can improve antioxidant capacity, protein content, collagen synthesis and texture quality of swim bladder. The enhancement of swim bladder texture, including hardness, chewiness, springiness, and adhesiveness may be caused by changes in the expression of related genes, such as colga1t1, col12a1, cyp27a1, etc. These results indicated that appropriate fish meal replaced by CPs could be applied during aquaculture practice after comprehensive consideration of feed cost, growth rate and quality of swim bladder. This study provides support for the development of cost-effective feed formulations that improve the sustainability and economic viability of chu’s croaker culture.

Aluminum Oxide Nanoparticles as a Photocatalyst for Water Splitting

Among various photoinduced hydrogen gas production techniques, photochemical catalytic water splitting is promising and an ideal future energy source because of the low cost, stability, and high sustainability of the reaction system features. Aluminum oxide nanoparticles (Al2O3NPs) as a photocatalyst for the splitting of water into hydrogen gas using solar energy is one of the noble missions of material science. In this work, pure aluminum oxide and L-methionine-capped aluminum oxide NPs have been synthesized using the sol-gel method. The pure Al2O3 and capped Al2O3 NPs with L- methionine were investigated by Fourier transform infrared (FTIR), X-ray diffractometer (XRD), high- resolution transmission electron microscopy (HRTEM), and Zeta potential. It was found that the average particle sizes of Al2O3 NPs and capped Al2O3 NPs with L-methionine were 13 and 20 nm, respectively. L-methionine-capped Al2O3 NPs had a higher negative charge with a potential of - 24.5 mV. The capping agent slightly improved the production of hydrogen from 44 to 60 ml at 75° C after 30 min under illumination.

Light-emitting diode-based absorbance detectors for flow-through analysis in analytical chemistry: A tutorial

The development of light-emitting diodes (LEDs) has played a significant role supporting many recent advances made in chemical analysis. Their small size, low power consumption, and semi-monochromaticity make them ideal light sources for portable photometric devices used in field and on-site analysis, environmental monitoring, and industrial applications, such as process analytical technology (PAT) and continuous real-time analysis. This tutorial provides an overview and critical comparison of the key components in LED-based absorbance detectors, including light sources, optical fibres, flow cells, and photodetectors. Fundamental aspects of LEDs relating to their use in such simple detectors are discussed in detail, along with the development of multi-wavelength detectors that incorporate multiple LEDs. The tutorial also details the different methodologies for assessing and characterising the LED-based absorbance detectors. Finally, this tutorial presents some selected applications of LED based photometric detectors in gas sensing, flow injection analysis (FIA), and coupled with separation techniques such as ion chromatography, liquid chromatography, and capillary zone electrophoresis (CZE).

Influence of GUP corrected Casimir energy on zero tidal force wormholes in modified teleparallel gravity with matter coupling

In recent times, the study of the Casimir effect in quantum field theory has garnered increasing attention because of its potential to be an ideal source of exotic matter needed for stabilizing traversable wormholes. It has been confirmed through experimental evidence that this phenomenon involves fluctuations in the vacuum field, leading to a negative energy density. Motivated by the above, we have investigated Casimir wormholes with corrections from the Generalized Uncertainty Principle (GUP) within the framework of matter-coupled teleparallel gravity. Our analysis includes three well-known GUP models: the Kempf, Mangano, and Mann (KMM) model, the Detournay, Gabriel, and Spindel (DGS) model, and a third model called Model II. For a broader analysis, we have considered two well-known model functions for the teleparallel theory: a linear f(T,T)=αT+βT\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$f(T,\\mathcal {T})=\\alpha T+\\beta \\mathcal {T}$$\\end{document} and a quadratic model f(T,T)=ηT2+χT\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$f(T,\\mathcal {T})=\\eta T^2+\\chi \\mathcal {T}$$\\end{document}. The shape function solutions corresponding to both models are examined in the absence of tidal forces in spacetime. We also demonstrate the crucial role played by the parameters of the f(T,T)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$f(T,\\mathcal {T})$$\\end{document} models in the violation of the energy conditions. With the increasing interest in detecting gravitational waves from astrophysical objects, we have thoroughly discussed the perturbation of the wormhole solutions in the scalar, electromagnetic, axial gravitational, and Dirac field backgrounds. We employ the 3rd order WKB expansion to find the complex frequencies associated with the quasinormal modes of energy dissipation. Additionally, we also calculate the active mass and total gravitational energy for the wormhole geometry. The amount of exotic matter involved in sustaining these wormholes is also found in this paper. Furthermore, the physical stability of such Casimir wormholes is examined using the Tolman–Oppenheimer–Volkoff equation.

High paracrine activity of hADSCs cartilage microtissues inhibits extracellular matrix degradation and promotes cartilage regeneration

Due to its unique structure, articular cartilage has limited self-repair capacity. Microtissues are tiny tissue clusters that can mimic the function of target organs or tissues. Using cells alone for microtissue construction often results in the formation of necrotic cores. However, the extracellular matrix (ECM) of native cartilage can provide structural support and is an ideal source of microcarriers. Autologous adipose-derived mesenchymal stem cells (ADSCs) and bone marrow mesenchymal stem cells (BMSCs) are widely used in cartilage tissue engineering. In this study, we fabricated microcarriers and compared the behavior of two homologous cell types in the microcarrier environment. The microcarrier environment highlighted the advantages of ADSCs and promoted the proliferation and migration of these cells. Then, ADSCs microtissues (ADSCs-MT) and BMSCs microtissues (BMSCs-MT) were fabricated using a three-dimensional dynamic culture system. In vitro and in vivo experiments verified that the cartilage regeneration ability of ADSCs-MT was significantly superior to that of BMSCs-MT. Transcriptomics revealed that ADSCs-MT showed significantly lower expression levels of ECM degradation, osteogenesis, and fibrocartilage markers. Finally, the protective effect of microtissues on inflammatory chondrocytes was validated. Overall, the ADSCs-MT constructed in this study achieved excellent cartilage regeneration and could be promising for the autologous application of cartilage microtissues.

Photokatalytische PPh3‐vermittelte Synthese von C3‐funktionalisierten Indolen über radikalische Anellierung von Nitroaromaten und Alkenen

AbstractOxidativ erzeugte Phosphin‐Radikalkationen sind reaktive Intermediate, die über Deoxygenierungsprozesse zur Erzeugung von kohlenstoff‐ und heteroatomzentrierten Radikalen verwendet werden können. Solche P‐Radikalkationen lassen sich leicht durch Ein‐Elektronentransfer‐Oxidation mit einem Redoxkatalysator erzeugen. Günstige und kommerziell erhältliche Nitroaromaten sind ideale Stickstoffquellen zum Aufbau organischer Amine und stickstoffhaltiger Heterozyklen. Die Aktivierung von Nitroaromaten mit Phosphinen wurde bereits in ionischen Prozessen erreicht, die jedoch spezielle Phosphor‐Nukleophile und hohe Temperaturen erfordern. In dieser Arbeit wird über einen alternativen Weg der Nitroaktivierung berichtet, der über einen radikalischen Prozess verläuft. Diese Strategie führt zu offenschaligen Zwischenprodukten, die eine interessante, unerforschte Reaktivität zeigen. Dies wird durch die Entwicklung einer wirtschaftlichen und hoch effizienten Synthese wertvoller Indolderivate durch photokatalytische PPh3‐vermittelte Anellierung von Nitroaromaten mit Alkenen dokumentiert. Die Sequenz weist eine große Toleranz gegenüber funktionellen Gruppen auf. Das Verfahren ermöglicht die Aktivierung von Nitroaromaten bei Raumtemperatur, wobei eine doppelte C−H‐Bindungsfunktionalisierung von Alkenen erreicht wird, um einen schnellen Zugang zu C3‐funktionalisierten Indolen zu bieten, die Schlüsselstrukturkomponenten verschiedener Naturstoffe und Arzneimittel darstellen. Mechanistische Studien, die durch DFT‐Berechnungen weiter unterstützt werden, deuten darauf hin, dass ein Nitrosoaryl‐Radikalkation eine Schlüsselrolle im Anellierungsprozess spielt.

1,3-Difunctionalization of Donor-Acceptor Cyclopropanes Enabled by Copper Nitrate: A Direct Approach to γ-Halonitrates.

1,3-Difunctionalization of donor-acceptor cyclopropanes with copper nitrate and N-halosuccinimide was developed to efficiently afford γ-halonitrates. The pivotal factor of this protocol lies in the dual role of copper nitrate as a Lewis acid and an ideal nitrooxy source. The given approach features easy handling, good functional group compatibility, and wide substrate scope. Furthermore, various transformations of the obtained γ-chloronitrates underscore the remarkable synthetic potential inherent in this method.

Photocatalytic PPh3-Mediated Synthesis of C3-Functionalized Indoles via Radical Annulation of Nitroarenes and Alkenes.

Oxidatively generated phosphine radical cations are reactive intermediates that can be used for the generation of carbon and heteroatom centered radicals via deoxygenation processes. Such P-radical cations can readily be generated via single electron transfer oxidation using a redox catalyst. Cheap and commercially available nitroarenes are ideal nitrogen sources for the construction of organic amines and N-containing heterocycles. Activation of nitroarenes with phosphines has been achieved in the ionic mode, which requires specially designed P-nucleophiles and high temperatures. Herein, we report an alternative mode of nitro activation that proceeds via a radical process. The radical strategy leads to open shell intermediates that show interesting unexplored reactivity. This is documented by the development of an economic and highly efficient synthesis of valuable indole derivatives through photocatalytic PPh3-mediated annulation of nitroarenes with alkenes showing large functional group tolerance. The method allows room-temperature activation of nitroarenes and a double C-H bond functionalization of alkenes is achieved to provide rapid access to C3-functionalized indoles, which are key structural components of diverse natural and drug molecules. Experimental mechanistic studies that are further supported by DFT calculations indicate that a nitrosoarene radical cation plays a key role in the annulation process.

“I’m Not Gonna Let My Daughter Be Ashamed of Who Her Father Is”: Assessing the Complex Relationship Between Fatherhood, Recovery, and Desistance

A growing body of literature assesses the relationship between fatherhood and criminal justice outcomes, including recidivism. Minimal research views this relationship within the context of substance use disorders (SUDs), a common and critical complication to desistance pathways. Using a longitudinal sample, we assess the relationship between fatherhood and desistance both quantitatively ( n = 177) and qualitatively ( n = 60). Finding null results in survival analyses, our analysis focuses primarily on our in-depth interviews, which shed light on the complicated juxtaposition between positive fatherhood identities and barriers to child reunification. We find that fatherhood provides a motivating source of positive identity, but fractured relationships with children and co-parents impact the actualization of parenting goals.

Microbial Pigment Isolation, Culturing, and Extraction to Use as Textile Dyes

The textile industry is one of the largest worldwide polluters of clean water due to the heavy use of synthetic dyes. These chemicals negatively affect the environment, especially aquatic life due to their toxic and mutagenic properties. Synthetic dyes cause harm to human health such as skin allergies and respiratory sensitization. Several advantages such as ease of extraction, availability, high yields and no seasonal variation make microbial pigments the most ideal source of natural pigments. This study was done to isolate colour pigment producing bacteria and fungi from soil collected from organic farms from various locations in Sri Lanka. Out of 7 soil samples, 3 yielded pigment producing bacteria and fungi. In total, 9 pigment producing bacteria and 3 pigment producing fungi were isolated. Gause’s synthetic agar yielded the most pigmented isolates. Isolates were inoculated in broths and pigment production was observed. Extracellular pigments produced by 5 of the bacterial isolates were extracted by a water-based method. The antibacterial activity of the pigments in their crude and concentrated forms was tested using the well diffusion method against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538P. Inhibition zone against S. aureus was observed for both crude (12.33±0.58mm) and concentrated pigments (9.67±0.58mm) extracted from purple pigment producing bacterial isolate (BPU). This pigment has the potential to be used in antibacterial textile preparation. Extracted pigments were used to dye scoured cotton fabric with the use of 3% alum as mordant. Pigment from BPU isolate resulted in better coloured fabric.

Taming CO2•- via Synergistic Triple Catalysis in Anti-Markovnikov Hydrocarboxylation of Alkenes.

The direct utilization of carbon dioxide as an ideal one-carbon source in value-added chemical synthesis has garnered significant attention from the standpoint of global sustainability. In this regard, the photo/electrochemical reduction of CO2 into useful fuels and chemical feedstocks could offer a great promise for the transition to a carbon-neutral economy. However, challenges in product selectivity continue to limit the practical application of these systems. A robust and general method for the conversion of CO2 to the polarity-reversed carbon dioxide radical anion, a C1 synthon, is critical for the successful valorization of CO2 to selective carboxylation reactions. We demonstrate herein a hydride and hydrogen atom transfer synergy driven general catalytic platform involving CO2•- for highly selective anti-Markovnikov hydrocarboxylation of alkenes via triple photoredox, hydride, and hydrogen atom transfer catalysis. Mechanistic studies suggest that the synergistic operation of the triple catalytic cycle ensures a low-steady-state concentration of CO2•- in the reaction medium. This method using a renewable light energy source is mild, robust, selective, and capable of accommodating a wide range of activated and unactivated alkenes. The highly selective nature of the transformation has been revealed through the synthesis of hydrocarboxylic acids from the substrates bearing a hydrogen atom available for intramolecular 1,n-HAT process as well as diastereoselective synthesis. This technology represents a general strategy for the merger of in situ formate generation with a synergistic photoredox and HAA catalytic cycle to provide CO2•- for selective chemical transformations.

Identification of umami peptides and mechanism of the interaction with umami receptors T1R1/T1R3 in pigeon meat.

Pigeon meat offer an ideal source for extracting fresh flavor peptides. These peptides not only enhance the taste of food but also have potential health benefits, including providing low-sugar, low-sodium, and low-calorie options for individuals with conditions like diabetes, hypertension, and obesity. Therefore, further research into the pigeon industry holds promise for addressing both economic and nutritional needs. To explore umami peptides and their molecular binding mechanisms with umami receptor type 1 member 1 in pigeon meat, an enzymatic hydrolysate product is isolated, analyzed, and subjected to sensory evaluation. Fifteen peptides with high freshness characteristics are separated and identified by ultrafiltration, gel separation, reverse performance liquid chromatography, and nano-liquid chromatography-tandem mass spectrometry (nano-LC-MS/MS). The molecular docking results show that the amino acid residue Glu128 is a common ligand binding site for all of the fresh-flavored peptides to taste T1R1/T1R3 receptors and it exerts freshness-presenting effects with 15 fresh-flavored peptides through hydrogen bonding, electrostatic interactions, salt bridges, and hydrophobic interactions. This study provides a theoretical basis and technical support for the subsequent development of flavor peptide products in pigeon meat.