Background Nematodes are the most abundant metazoans in marine sediments, many of which are bacterivores;however, how habitat bacteria affect physiological outcomes in marine nematodes remains largely unknown. Results...
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Background Nematodes are the most abundant metazoans in marine sediments, many of which are bacterivores;however, how habitat bacteria affect physiological outcomes in marine nematodes remains largely unknown. Results Here, we used a Litoditis marina inbred line to assess how native bacteria modulate host nematode physiology. We characterized seasonal dynamic bacterial compositions in L. marina habitats and examined the impacts of 448 habitat bacteria isolates on L. marina development, then focused on HQbiome with 73 native bacteria, of which we generated 72 whole genomes sequences. Unexpectedly, we found that the effects of marine native bacteria on the development of L. marina and its terrestrial relative Caenorhabditis elegans were significantly positively correlated. Next, we reconstructed bacterial metabolic networks and identified several bacterial metabolic pathways positively correlated with L. marina development (e.g., ubiquinol and heme b biosynthesis), while pyridoxal 5'-phosphate biosynthesis pathway was negatively associated. Through single metabolite supplementation, we verified CoQ10, heme b, acetyl-CoA, and acetaldehyde promoted L. marina development, while vitamin B6 attenuated growth. Notably, we found that only four development correlated metabolic pathways were shared between L. marina and C. elegans. Furthermore, we identified two bacterial metabolic pathways correlated with L. marina lifespan, while a distinct one in C. elegans. Strikingly, we found that glycerol supplementation significantly extended L. marina but not C. elegans longevity. Moreover, we comparatively demonstrated the distinct gut microbiota characteristics and their effects on L. marina and C. elegans physiology. Conclusions Given that both bacteria and marine nematodes are dominant taxa in sedimentary ecosystems, the resource presented here will provide novel insights to identify mechanisms underpinning how habitat bacteria affect nematode biology in a more natural context. Ou
Compared with natural enzymes, nanozymes have the advantages of high stability and low cost;however,selectivity and sensitivity are key issues that prevent their further development. In this study, we report a cascade...
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Compared with natural enzymes, nanozymes have the advantages of high stability and low cost;however,selectivity and sensitivity are key issues that prevent their further development. In this study, we report a cascade nanozymatic system with significantly improved selectivity and sensitivity that combines more substrate-specific reactions and sensitive fiuorescence detection. Taking detection of ascorbic acid(AA)as an example, a cascade catalytic reaction system consisting of oxidase-like N-doped carbon nanocages(NC) and peroxidase-like copper oxide(Cu O) improved the reaction selectivity in transforming the substrate into the target product by more than 1200 times against the interference of uric acid. The cascade catalytic reaction system was also applicable for transfer from open reactors into a spatially confined microfiuidic device, increasing the slope of the calibration curves by approximately 1000-fold with a linear detection range of 2.5 nmol/L to 100 nmol/L and a low limit of detection of 0.77 nmol/L. This work offers a new strategy that achieves significant improvements in selectivity and sensitivity.
Ascorbate (H(2)A) is a well-known antioxidant to protect cellular components from free radical damage and has also emerged as a pro-oxidant in cancer therapies. However, such "contradictory" mechanisms under...
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Ascorbate (H(2)A) is a well-known antioxidant to protect cellular components from free radical damage and has also emerged as a pro-oxidant in cancer therapies. However, such "contradictory" mechanisms underlying H(2)A oxidation are not well understood. Herein, we report Fe leaching during catalytic H(2)A oxidation using an Fe-N-C nanozyme as a ferritin mimic and its influence on the selectivity of the oxygen reduction reaction (ORR). Owing to the heterogeneity, the Fe-N-x sites in Fe-N-C primarily catalyzed H(2)A oxidation and 4 e(-) ORR via an iron-oxo intermediate. Nonetheless, trace O-2(center dot-) produced by marginal N-C sites through 2 e(-) ORR accumulated and attacked Fe-N-x sites, leading to the linear leakage of unstable Fe ions up to 420 ppb when the H(2)A concentration increased to 2 mM. As a result, a substantial fraction (ca. 40 %) of the N-C sites on Fe-N-C were activated, and a new 2+2 e(-) ORR path was finally enabled, along with Fenton-type H(2)A oxidation. Consequently, after Fe ions diffused into the bulk solution, the ORR at the N-C sites stopped at H2O2 production, which was the origin of the pro-oxidant effect of H(2)A.
The development of electrochemiluminescence (ECL) emitters of different colors with high ECL efficiency (0ECL) is appealing yet challenging for ultrasensitive multiplexed bioassays. Herein, we report the synthesis of ...
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The development of electrochemiluminescence (ECL) emitters of different colors with high ECL efficiency (0ECL) is appealing yet challenging for ultrasensitive multiplexed bioassays. Herein, we report the synthesis of highly efficient polymeric carbon nitride (CN) films with fine-tuned ECL emission from blue to green (410, 450, 470, and 525 nm) using the precursor crystallization method. More importantly, naked eye observable and significantly enhanced ECL emission was achieved, and the cathodic 0ECL values were ca. 112, 394, 353, and 251 times those of the aqueous Ru(bpy)3Cl2/K2S2O8 reference. Mechanism studies showed that the density of surface-trapped electrons, the associated nonradiative decay pathways, and electron-hole recombination kinetics were crucial factors for the high 0ECL of CN. Based on high 0ECL and different colors of ECL emission, the wavelength-resolved multiplexing ECL biosensor was constructed to simultaneously detect miRNA-21 and miRNA-141 with superior low detection limits of 0.13 fM and 25.17 aM, respectively. This work provides a facile method to synthesize wavelength-resolved ECL emitters based on metal-free CN polymers with high 0ECL for multiplexed bioassays.
Dietary intake and nutrient composition regulate animal growth and development;however, the underlying mechanisms remain elusive. Our previous study has shown that either the mammalian deafness homolog gene tmc-1 or i...
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Dietary intake and nutrient composition regulate animal growth and development;however, the underlying mechanisms remain elusive. Our previous study has shown that either the mammalian deafness homolog gene tmc-1 or its downstream acetylcholine receptor gene eat-2 attenuates Caenorhabditis elegans development in a chemically defined food CeMM (C. elegans maintenance medium) environment, but the underpinning mechanisms are not well-understood. Here, we found that, in CeMM food environment, for both eat-2 and tmc-1 fast-growing mutants, several fatty acid synthesis and elongation genes were highly expressed, while many fatty acid beta-oxidation genes were repressed. Accordingly, dietary supplementation of individual fatty acids, such as monomethyl branch chain fatty acid C17ISO, palmitic acid and stearic acid significantly promoted wild-type animal development on CeMM, and mutations in either C17ISO synthesis gene elo-5 or elo-6 slowed the rapid growth of eat-2 mutant. Tissue-specific rescue experiments showed that elo-6 promoted animal development mainly in the intestine. Furthermore, transcriptome and metabolome analyses revealed that elo-6/C17ISO regulation of C. elegans development may be correlated with up-regulating expression of cuticle synthetic and hedgehog signaling genes, as well as promoting biosynthesis of amino acids, amino acid derivatives and vitamins. Correspondingly, we found that amino acid derivative S-adenosylmethionine and its upstream metabolite methionine sulfoxide significantly promoted C. elegans development on CeMM. This study demonstrated that C17ISO, palmitic acid, stearic acid, S-adenosylmethionine and methionine sulfoxide inhibited or bypassed the TMC-1 and EAT-2-mediated attenuation of development via metabolic remodeling, and allowed the animals to adapt to the new nutritional niche.
Regulation of the reaction pathways is a perennial theme in the field of chemistry. As a typical chromogenic substrate, 3,3 ',5,5 '-tetramethylbenzidine (TMB) generally undertakes one-electron oxidation, but t...
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Regulation of the reaction pathways is a perennial theme in the field of chemistry. As a typical chromogenic substrate, 3,3 ',5,5 '-tetramethylbenzidine (TMB) generally undertakes one-electron oxidation, but the product (TMBox1) is essentially a confused complex and is unstable, which significantly hampers the clinic chromogenic bioassays for more than 50 years. Herein, we report that sodium dodecyl sulfate (SDS)-based micelles could drive the direct two-electron oxidation of TMB to the final stable TMBox2. Rather than activation of H2O2 oxidant in the one-electron TMB oxidation by common natural peroxidase, activation of the TMB substrate by SDS micelles decoupled the thermodynamically favorable complex between TMBox2 with unreacted TMB, leading to an unusual direct two-electron oxidation pathway. Mechanism studies demonstrated that the complementary spatial and electrostatic isolation effects, caused by the confined hydrophobic cavities and negatively charged outer surfaces of SDS micelles, were crucial. Further cascading with glucose oxidase, as a proof-of-concept application, allowed glucose to be more reliably measured, even in a broader range of concentrations without any conventional strong acid termination.
A single stimulus leading to multiple responses is an essential function of many biological networks, which enable complex life activities. However, it is challenging to duplicate a similar chemical reaction network (...
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A single stimulus leading to multiple responses is an essential function of many biological networks, which enable complex life activities. However, it is challenging to duplicate a similar chemical reaction network (CRN) using non-living chemicals, aiming at the disclosure of the origin of life. Herein, we report a nanozyme-based CRN with feedback and feedforward functions for the first time. It demonstrates multiple responses at different modes and intensities upon a single H2O2 stimulus. In the two-electron cascade oxidation of 3,3 ',5,5 '-tetramethylbenzidine (TMB), the endogenous product H2O2 competitively inhibited substrates in the first one-electron oxidation reaction on a single-atom nanozyme (Co-N-CNTs) and strikingly accelerated the second one-electron oxidation reaction under a micellar nanozyme. As a proof-of-concept, we further confined the nanozymatic network to a microfluidic chip as a simplified artificial cell. It exhibited remarkable selectivity and linearity in the perception of H2O2 stimulus against more than 20 interferences in a wide range of concentrations (0.01-100 mM) and offered an instructive platform for studying primordial life-like processes.
The whitespotted conger (Conger myriaster) is an ecologically and economically significant benthic marine species widely distributed across East Asia's coastal waters. Despite this importance, the genomic resource...
The whitespotted conger (Conger myriaster) is an ecologically and economically significant benthic marine species widely distributed across East Asia's coastal waters. Despite this importance, the genomic resources for this species remain limited, hindering evolutionary and aquaculture research. Here, we present the first high-quality chromosome-level genome assembly of C. myriaster using PacBio CLR, WGS, 10X Genomics and Hi-C data. The resulting 1.09 Gb genome assembly exhibits excellent contiguity, with 97.49% of sequences anchored onto 19 chromosomes. The assembled genome achieved a BUSCO completeness stands at 98.00%, containing 34.80% repetitive sequences and 24,063 predicted protein-coding genes. This foundational genomic resource overcomes a major limitation, providing the essential framework for future investigations into the evolutionary adaptations and for the genetic improvement of C. myriaster in aquaculture.
Electrochemically generated chemiluminescence (ECL) has attracted significant interest over the past decades, ranging from fundamental studies on highly efficient electron-to-photon interconversion to practical bioass...
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Electrochemically generated chemiluminescence (ECL) has attracted significant interest over the past decades, ranging from fundamental studies on highly efficient electron-to-photon interconversion to practical bioassays. Nonetheless, the ECL efficiency (phi(ECL)) of most emitters is low, which significantly hampers further development. Herein, this work reports a highly robust carbon nitride film with unusually enhanced ECL efficiency (2256 times higher than that of the reference Ru(bpy)(3)Cl-2/K2S2O8). Double crystallization, which provides the primary interaction of carbon nitride with the substrate and subsequent growth, plays a crucial role in the preparation. The improved ECL efficiency is ascribed to little pinholes suppressing futile co-reagent reduction, maintenance of more orbit-delocalized heptazine subunits improving ECL kinetics, and high transparency avoiding self-absorption. As a potential application, an ultrasensitive visual DNA biosensor by the naked eye is further successfully developed with a linear detection range of 100 pm to 1 mu m and limit of detection of 27 pm (S/N = 3).
Self-adaptability is highly envisioned for artificial devices such as robots with chemical noses. For this goal, seeking catalysts with multiple and modulable reaction pathways is promising but generally hampered by i...
Self-adaptability is highly envisioned for artificial devices such as robots with chemical noses. For this goal, seeking catalysts with multiple and modulable reaction pathways is promising but generally hampered by inconsistent reaction conditions and negative internal interferences. Herein, we report an adaptable graphitic C6N6-based copper single-atom catalyst. It drives the basic oxidation of peroxidase substrates by a bound copper-oxo pathway, and undertakes a second gain reaction triggered by light via a free hydroxyl radical pathway. Such multiformity of reactive oxygen-related intermediates for the same oxidation reaction makes the reaction conditions capable to be the same. Moreover, the unique topological structure of CuSAC6N6 along with the specialized donor-pi-acceptor linker promotes intramolecular charge separation and migration, thus inhibiting negative interferences of the above two reaction pathways. As a result, a sound basic activity and a superb gain of up to 3.6 times under household lights are observed, superior to that of the controls, including peroxidase-like catalysts, photocatalysts, or their mixtures. CuSAC6N6 is further applied to a glucose biosensor, which can intelligently switch sensitivity and linear detection range in vitro. Catalysts with multiple and modulable reaction pathways are promising but generally hampered by inconsistent reaction conditions and negative internal interferences. Herein, the authors report an adaptable graphitic C6N6-based copper singleatom catalyst
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