Direct interspecies electron transfer for environmental treatment and chemical electrosynthesis: A review

Microbial electric syntrophy, involving direct electron transfer between electron-donating strains and electron-accepting strains, could reduce more than 50% of methane emissions and remove 90% of nitrate pollution in some wastewaters. Microbial electric syntrophy is also a key natural process allowing the survival of bacteria in harsh environmental conditions. Here we review natural and artificial cases of interspecies electron transfer in microbial syntrophy, with emphasis on methane production, electroactive bacteria, methanogens, anaerobic methane-oxidizing consortia, Geobacter species, phototrophic bacteria, co-cultures, anaerobic digestion, environmental remediation and microbial electrosynthesis. Environmental remediation includes nitrogen removal, reductive dechlorination and pollutant degradation. Microbial electrosynthesis can be used for carbon dioxide reduction. Conductive proteins and materials, and light-assisted electron transfer contribute to the direct interspecies electron transfer

Triterpene Glycosides from the Viscera of Sea Cucumber <i>Apostichopus japonicus</i> with Embryotoxicity

Sea cucumbers release chemical repellents from their guts when they are in danger from predators or a hostile environment. To investigate the chemical structure of the repellent, we collected and chemically analyzed the viscera of stressed sea cucumbers (Apostichopus japonicus) in the Yellow Sea of China. Two undescribed triterpene glycosides (1 and 2), together with a known cladoloside A (3), were identified and elucidated as 3 beta-O-{2-O-[beta-d-quinovopyranosyl]-4-O-[3-O-methyl-beta-d-glucopyranosyl-(1 -> 3)-beta-d-glucopyranosyl]-beta-d-xylopyranosyl}-holosta-9(11),25(26)-dien-16-one (1), 3 beta-O-{2-O-[beta-d-glucopyranosyl]-4-O-[3-O-methyl-beta-d-glucopyranosyl-(1 -> 3)-beta-d-glucopyranosyl]-beta-d-xylopyranosyl}-holosta-9(11),25(26)-dien-16-one (2), 3 beta-O-{2-O-[3-O-methyl-beta-d-glucopyranosyl-(1 -> 3)-beta-d-xylopyranosyl-(1 -> 4)-beta-d-quinovopyranosyl]-beta-d-xylopyranosyl}-holosta-9(11),25(26)-dien-16-one (3) by spectroscopic analysis, including HR-ESI-MS and NMR spectra. Compounds 1, 2, and 3 display embryonic toxicity, as indicated by their 96-hour post-fertilization lethal concentration (96 hpf-LC50) values of 0.289, 0.536, and 0.091 mu M, respectively. Our study discovered a class of triterpene glycoside compounds consisting of an oligosaccharide with four sugar units and a holostane aglycone. These compounds possess embryotoxicity and may serve as chemical defense molecules in marine benthic ecosystems

Synthesis and characterization of novel carboxymethyl inulin derivatives bearing cationic Schiff bases with antioxidant potential

This study aimed to enhance the antioxidant activity of carboxymethyl inulin (CMI) by chemical modification. Therefore, a series of cationic Schiff bases bearing heteroatoms were synthesized and incorporated into CMI via ion exchange reactions, ultimately preparing 10 novel CMI derivatives (CMID). Their structures were confirmed by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy. The radical scavenging activities and reducing power of inulin, CMI, and CMID were studied. The results revealed a significant enhancement in antioxidant activity upon the introduction of cationic Schiff bases into CMI. Compared to commercially available antioxidant Vc, CMID demonstrated a broader range of antioxidant activities across the four antioxidant systems analyzed in this research. In particular, CMID containing quinoline (6QSCMI) exhibited the strongest hydroxyl radical scavenging activity, with a scavenging rate of 93.60 % at 1.6 mg mL- 1. The CMID bearing imidazole (2MSCMI) was able to scavenge 100 % of the DPPH radical at 1.60 mg mL- 1. Furthermore, cytotoxicity experiments showed that the products had good biocompatibility. These results are helpful for evaluating the feasibility of exploiting these products in the food, biomedical, and cosmetics industries

Novel Insight into the Synergistic Mechanism for Pd and Rh Promoting the Hydro-Defluorination of 4-Fluorophenol over Bimetallic Rh-Pd/C Catalysts

This study explores the synergistic effect between the Rh and Pd of bimetallic Rh-Pd/C catalysts for the catalytic hydro-defluorination (HDF) of 4-fluorophenol (4-FP). It was found that 4-FP could not be efficiently hydro-defluorinated over 6% Pd/C and 6% Rh/C due to the inherent properties of Pd and Rh species in the dissociation of H-2 and the activation of C-F bonds. Compared with 6% Pd/C and 6% Rh/C, bimetallic Rh-Pd/C catalysts, especially 1% Rh-5% Pd/C, exhibited much higher catalytic activity in the HDF of 4-FP, suggesting that the synergistic effect between the Rh and Pd of the catalyst was much more positive. Catalyst characterizations (BET, XRD, TEM, and XPS) were introduced to clarify the mechanism for the synergistic effect between the Rh and Pd of the catalyst in the HDF reaction and revealed that it was mainly attributed to the bifunctional mechanism: Pd species were favorable for the dissociation of H-2, and Rh species were beneficial to the activation of C-F bonds in the HDF reaction. Meanwhile, the interaction between Rh and Pd species enabled Rh and Pd to exhibit a more positive synergistic effect, which promoted the migration of atomic H* from Pd to Rh species and thus enhanced the HDF of 4-FP. Furthermore, 1% Rh-5% Pd/C prepared using 20-40 equiv NaBH4 exhibited the best performance in the catalytic HDF of 4-FP. Catalysis characterizations suggested that appropriate Rh3+/Rh-0 and Pd2+/Pd-0 ratios were beneficial to the dissociation of H-2 and the activation of C-F bonds, which caused the more positive synergistic effect between the Rh and Pd of Rh-Pd/C in the HDF reaction. This work offers a valuable strategy for enhancing the performance of catalytic HDF catalysts via promoting synergistic effects

The influences of Yellow River input and nutrient dynamics on colloidal Fe migration in the Bohai Sea, China

The coupling relationship between the <1 kDa, 1-3 kDa, 3-10 kDa, 10-100 kDa, and 100 kDa-0.45 mu m Fe fractions and the environmental factors in the Bohai Sea (BS) was investigated. The 1-100 kDa Fe in the surface water exhibited a non-conservative phenomenon during the river-sea mixing process, which was related to the removal of colloidal Fe via flocculation during this process. For the bottom water, the ligands released by the sediments may form additions to the <100 kDa Fe. The COC and DOC were mainly closely related to the behavior of the Fe in the bottom water. The <1 and 3-10 kDa Fe was mainly significantly positively correlated with the DOC, while the <100 kDa-0.45 mu m Fe was significantly negatively correlated with the DOC. <100 kDa LMW colloidal Fe exhibited more synergistic behavior with easily absorbed ammonium salts

Carbon fluxes of China's coastal wetlands and impacts of reclamation and restoration

Coastal wetlands play an important role in regulating atmospheric carbon dioxide (CO2) concentrations and contribute significantly to climate change mitigation. However, climate change, reclamation, and restoration have been causing substantial changes in coastal wetland areas and carbon exchange in China during recent decades. Here we compiled a carbon flux database consisting of 15 coastal wetland sites to assess the magnitude, patterns, and drivers of carbon fluxes and to compare fluxes among contrasting natural, disturbed, and restored wetlands. The natural coastal wetlands have the average net ecosystem exchange of CO2 (NEE) of -577 g C m(-2) year(-1), with -821 g C m(-2) year(-1) for mangrove forests and -430 g C m(-2) year(-1) for salt marshes. There are pronounced latitudinal patterns for carbon dioxide exchange of natural coastal wetlands: NEE increased whereas gross primary production (GPP) and respiration of ecosystem decreased with increasing latitude. Distinct environmental factors drive annual variations of GPP between mangroves and salt marshes; temperature was the dominant controlling factor in salt marshes, while temperature, precipitation, and solar radiation were co-dominant in mangroves. Meanwhile, both anthropogenic reclamation and restoration had substantial effects on coastal wetland carbon fluxes, and the effect of the anthropogenic perturbation in mangroves was more extensive than that in salt marshes. Furthermore, from 1980 to 2020, anthropogenic reclamation of China's coastal wetlands caused a carbon loss of similar to 3720 Gg C, while the mangrove restoration project during the period of 2021-2025 may switch restored coastal wetlands from a carbon source to carbon sink with a net carbon gain of 73 Gg C. The comparison of carbon fluxes among these coastal wetlands can improve our understanding of how anthropogenic perturbation can affect the potentials of coastal blue carbon in China, which has implications for informing conservation and restoration strategies and efforts of coastal wetlands

SERS-based microdevices for use as <i>in vitro</i> diagnostic biosensors

Advances in surface-enhanced Raman scattering (SERS) detection have helped to overcome the limitations of traditional in vitro diagnostic methods, such as fluorescence and chemiluminescence, owing to its high sensitivity and multiplex detection capability. However, for the implementation of SERS detection technology in disease diagnosis, a SERS-based assay platform capable of analyzing clinical samples is essential. Moreover, infectious diseases like COVID-19 require the development of point-of-care (POC) diagnostic technologies that can rapidly and accurately determine infection status. As an effective assay platform, SERS-based bioassays utilize SERS nanotags labeled with protein or DNA receptors on Au or Ag nanoparticles, serving as highly sensitive optical probes. Additionally, a microdevice is necessary as an interface between the target biomolecules and SERS nanotags. This review aims to introduce various microdevices developed for SERS detection, available for POC diagnostics, including LFA strips, microfluidic chips, and microarray chips. Furthermore, the article presents research findings reported in the last 20 years for the SERS-based bioassay of various diseases, such as cancer, cardiovascular diseases, and infectious diseases. Finally, the prospects of SERS bioassays are discussed concerning the integration of SERS-based microdevices and portable Raman readers into POC systems, along with the utilization of artificial intelligence technology

Quantum phase synchronization via exciton-vibrational energy dissipation sustains long-lived coherence in photosynthetic antennas

The lifetime of electronic coherences found in photosynthetic antennas is known to be too short to match the energy transfer time, rendering the coherent energy transfer mechanism inactive. Exciton-vibrational coherence time in excitonic dimers which consist of two chromophores coupled by excitation transfer interaction, can however be much longer. Uncovering the mechanism for sustained coherences in a noisy biological environment is challenging, requiring the use of simpler model systems as proxies. Here, via two-dimensional electronic spectroscopy experiments, we present compelling evidence for longer exciton-vibrational coherence time in the allophycocyanin trimer, containing excitonic dimers, compared to isolated pigments. This is attributed to the quantum phase synchronization of the resonant vibrational collective modes of the dimer, where the anti-symmetric modes, coupled to excitonic states with fast dephasing, are dissipated. The decoupled symmetric counterparts are subject to slower energy dissipation. The resonant modes have a predicted nearly 50% reduction in the vibrational amplitudes, and almost zero amplitude in the corresponding dynamical Stokes shift spectrum compared to the isolated pigments. Our findings provide insights into the mechanisms for protecting coherences against the noisy environment. Photosynthesis in biological systems occurs in a noisy environment that reduces the lifetime of coherences in the excitation energy transfer. Here the author demonstrate that long-lasting coherences are protected by quantum phase synchronization, realized in dimers by exciton-vibrational coupling where energy dissipation occurs predominantly in resonant anti-symmetric collective modes

海水低氧和升温背景下纳米塑料对紫贻贝的毒理效应研究

作为一类新兴的环境污染物，纳米塑料对海洋生态系统的影响日益受到关注。相较于微塑料，纳米塑料具有更小的尺寸和更高的比表面积，这些特性可能使得纳米塑料对海洋生态系统构成了更为严重的影响。在全球气候变化背景下，海洋环境中的纳米塑料污染往往与气候变化压力源同时存在，从而对海洋生物和生态系统构成复合胁迫。然而，目前关于气候变化背景下纳米塑料的生态风险评估研究仍然非常有限。因此，亟需阐明纳米塑料和气候变化压力源对海洋生物的复合毒性效应及其作用机制，这是在不断变化的气候条件下进行纳米塑料生态风险评估和制定生态保护策略的重要环节。 紫贻贝（Mytilus galloprovincialis）是沿海生态系统中重要的基础物种，附着的生活习性使其难以逃离不利的生存环境；同时，滤食特性使得它们易于吸收水中的颗粒物，这些特性使得紫贻贝成为了评估纳米塑料污染和气候变化压力源联合毒性效应的理想指示生物。鉴于此，本研究以紫贻贝为研究对象，选取聚苯乙烯纳米塑料（Polystyrene Nanoplastics, PS-NPs）为模式纳米塑料，利用传统生态毒理学、转录组学和代谢组学等技术，从个体、组织、细胞和分子多层面探究了海水低氧和升温条件下PS-NPs对紫贻贝的毒理效应及其潜在作用机制。 主要研究内容和结果如下： （1）采用传统生态毒理学方法，通过测定PS-NPs的生物富集作用、标准代谢率、氧化应激生物标志物和血细胞参数，在个体、组织和细胞层面探究了PS-NPs和不同模式的低氧单独/复合暴露对紫贻贝的影响。结果表明，紫贻贝的鳃和消化腺组织均能富集海水中的PS-NPs，且消化腺中PS-NPs的富集量显著高于鳃组织。持续低氧降低了紫贻贝对PS-NPs的生物富集作用，这可能是由持续低氧条件下紫贻贝的标准代谢率降低所导致；然而，波动性低氧对紫贻贝组织内PS-NPs的富集和标准代谢率无显著影响。PS-NPs暴露和不同模式的低氧处理均能够诱导紫贻贝鳃组织产生氧化损伤现象，且波动性低氧进一步加剧了PS-NPs所导致的氧化损伤。此外，PS-NPs和波动性低氧均能够导致血细胞中活性氧含量的显著升高，而PS-NPs和持续低氧均可抑制血细胞的吞噬活性，且持续低氧能够加剧PS-NPs对吞噬活性的抑制作用。 （2）整合传统生态毒理学方法和靶向代谢组学技术，探究了PS-NPs和持续低氧单独/复合暴露对紫贻贝消化腺组织内中心碳代谢的影响。结果表明，PS-NPs和/或持续低氧处理均可导致紫贻贝消化腺内中心碳代谢物的显著变化；相较于单独暴露组，复合暴露导致了更多的中心碳代谢物含量改变，提示复合暴露对紫贻贝消化腺组织内中心碳代谢造成了更严重的干扰。PS-NPs暴露导致紫贻贝消化腺三羧酸循环速率下降，但为维持细胞能量供应，电子传递链的活性相应增强以补偿三羧酸循环速率的降低。然而，在PS-NPs和持续低氧复合暴露下，尽管机体试图通过提升三羧酸循环速率来维持细胞功能和生存，但由于持续低氧条件下氧气供应受到限制，电子传递链活性降低，最终导致紫贻贝消化腺内能量的缺乏。此外，PS-NPs和持续低氧均对磷酸戊糖途径产生负面影响，磷酸戊糖途径速率的降低导致NADPH供应的减少，进而破坏了消化腺内的氧化还原稳态；其中，PS-NPs和持续低氧复合暴露组中的紫贻贝遭受了最为严重的氧化还原稳态失衡，这种失衡进一步导致了机体的核酸损伤。作为适应性响应，紫贻贝在面临低氧及复合暴露压力时，能够通过调整无氧代谢途径中关键酶的活性以应对不利环境，但这一调整可能不足以完全抵消外部压力所带来的负面影响。 （3）采用传统生态毒理学方法，通过测定紫贻贝体内PS-NPs的生物富集作用、标准代谢率、氧化应激生物标志物和脂质含量，从个体、组织和细胞层面探究了PS-NPs和海水升温单独/复合暴露对紫贻贝的影响。结果表明，海水升温增加了低浓度PS-NPs暴露组消化腺中纳米塑料的积累，但对高浓度PS-NPs暴露组的积累则无显著影响，这可能与紫贻贝标准代谢率的变化策略有关。高浓度PS-NPs暴露可导致紫贻贝标准代谢率的显著降低，表明其对机体生理状态具有抑制作用；而在单独升温条件下，紫贻贝的标准代谢率会增加，以维持足够的能量摄入应对升温导致的生理压力。然而，高浓度PS-NPs与海水升温复合暴露并未导致标准代谢率的显著增加，提示高浓度纳米塑料可能阻碍了紫贻贝在海水温度升高时提高代谢率的能力。此外，在单一暴露情况下，PS-NPs和海水升温均能诱导紫贻贝消化腺中的氧化应激，而机体可通过其抗氧化系统积极响应以减少氧化应激。然而，复合暴露所导致的氧化应激可能超出了紫贻贝抗氧化防御系统可承受的范围，从而导致较高的脂质过氧化。PS-NPs和海水升温均能降低紫贻贝消化腺中甘油三酯的含量，且复合暴露组紫贻贝消化腺中的甘油三酯含量最低。此外，紫贻贝消化腺中胆固醇的含量随海水温度升高而增加，表明机体能够通过调整胆固醇含量来维持细胞膜的流动性和功能稳定。 （4）整合高通量非靶向代谢组学和转录组学技术，探究了PS-NPs和海水升温单独/复合暴露对紫贻贝消化腺组织代谢过程的扰动及其潜在的分子机制。结果发现：PS-NPs处理显著影响了紫贻贝消化腺中的脂肪酸氧化、甘油磷脂代谢，以及精氨酸和脯氨酸的代谢途径。具体而言，PS-NPs能够通过增加棕榈酰肉碱含量促进脂肪酸的β-氧化，以增强能量产生；但PS-NPs也干扰了甘油磷脂代谢途径，进而导致消化腺内膜成分代谢物含量的减少。此外，PS-NPs对紫贻贝消化腺中的精氨酸和脯氨酸代谢路径产生显著影响，干扰了氨排泄和脯氨酸代谢，进而影响三羧酸循环的效率。海水升温则显著影响了紫贻贝消化腺中的多不饱和脂肪酸代谢途径，包括花生四烯酸代谢、甘油磷脂代谢、α-亚麻酸代谢和亚油酸代谢，进而抑制了与免疫和炎症调节相关的生物活性代谢物的合成，表明海水升温可显著影响紫贻贝消化腺细胞膜的功能、氧化应激的敏感性以及炎症反应。在PS-NPs与海水升温复合暴露下，甘油磷脂代谢途径中的磷脂酰胆碱和溶血磷脂酰胆碱含量发生显著改变，表明复合暴露导致了严重的氧化应激，并对细胞吞噬活动和免疫反应产生了潜在的不利影响。此外，复合暴露还抑制了紫贻贝消化腺中与蛋白质合成相关的通路，进而影响了氨基酸的利用效率，导致氨基酸的积累。 综上所述，本研究初步探明了海水低氧和升温背景下PS-NPs对紫贻贝的毒性效应及其潜在作用机制，相关结果可为全球气候变化背景下纳米塑料的生态风险评估提供科学依据和数据支撑

Spatiotemporal variation of land surface temperature and its driving factors in Xinjiang, China

Land surface temperature (LST) directly affects the energy balance of terrestrial surface systems and impacts regional resources, ecosystem evolution, and ecosystem structures. Xinjiang Uygur Autonomous Region is located at the arid Northwest China and is extremely sensitive to climate change. There is an urgent need to understand the distribution patterns of LST in this area and quantitatively measure the nature and intensity of the impacts of the major driving factors from a spatial perspective, as well as elucidate the formation mechanisms. In this study, we used the MOD11C3 LST product developed on the basis of Moderate Resolution Imaging Spectroradiometer (MODIS) to conduct regression analysis and determine the spatiotemporal variation and differentiation pattern of LST in Xinjiang from 2000 to 2020. We analyzed the driving mechanisms of spatial heterogeneity of LST in Xinjiang and the six geomorphic zones (the Altay Mountains, Junggar Basin, Tianshan Mountains, Tarim Basin, Turpan-Hami (Tuha) Basin, and Pakakuna Mountain Group) using geographical detector (Geodetector) and geographically weighted regression (GWR) models. The warming rate of LST in Xinjiang during the study period was 0.24 degrees C/10a, and the spatial distribution pattern of LST had obvious topographic imprints, with 87.20% of the warming zone located in the Gobi desert and areas with frequent human activities, and the cooling zone mainly located in the mountainous areas. The seasonal LST in Xinjiang was at a cooling rate of 0.09 degrees C/10a in autumn, and showed a warming trend in other seasons. Digital elevation model (DEM), latitude, wind speed, precipitation, normalized difference vegetation index (NDVI), and sunshine duration in the single-factor and interactive detections were the key factors driving the LST changes. The direction and intensity of each major driving factor on the spatial variations of LST in the study area were heterogeneous. The negative feedback effect of DEM on the spatial differentiation of LST was the strongest. Lower latitudes, lower vegetation coverage, lower levels of precipitation, and longer sunshine duration increased LST. Unused land was the main heat source landscape, water body was the most important heat sink landscape, grassland and forest land were the land use and land cover (LULC) types with the most prominent heat sink effect, and there were significant differences in different geomorphic zones due to the influences of their vegetation types, climatic conditions, soil types, and human activities. The findings will help to facilitate sustainable climate change management, analyze local climate and environmental patterns, and improve land management strategies in Xinjiang and other arid areas