EDTA-Induced Self-Assembly of 3D Graphene and Its Superior Adsorption Ability for Paraquat Using a Teabag

In the past two years, three-dimensional graphene (3DG) was introduced to the environmental treatment area as a promising new material. Despite much progress in its synthesis and applications, 3DG is still limited in terms of green large-scale synthesis and practical environmental applications. In this work, a 3DG synthetic method was developed at 95 °C in an EDTA-induced self-assembly process. Because little EDTA was found to be consumed during synthesis, which might be due to its great stability and poor reducibility, 3DG with complete structure can be successively obtained by reusing the EDTA solution more than 10 times. Furthermore, 3DG was found to possess a superior adsorption capacity of 119 mg g^–1 (pH 6.0) for paraquat, a highly toxic herbicide with positive charges and a conjugated system of π bonds in its molecular structure. The adsorption capacity was much higher than those in classic paraquat adsorbents, such as clay and activated carbon. To address the problem of 3DG damage by stirring, a pyramid-shaped nylon teabag was adopted to protect the soft hydrogel during the repeated adsorption–desorption processes. After five cycles, the 3DG teabag still maintained 88% of the initial adsorption capacity. This facile method may be easily applied in other environmental treatment conditions

Transformation of Biofilm to Carbon Sinks after Prolonged Droughts Linked with Algal Biodiversity Change

Global climate change significantly increased the duration of droughts in intermittent rivers, impacting benthic microbial-mediated biogeochemical processes. However, the impact of prolonged droughts on the carbon contribution of intermittent rivers remains poorly understood. In this study, we investigated the potential effects of varying drought gradients (ranging from 20 to 130 days) on benthic biofilms community structure (algae, bacteria, and fungi) and their carbon metabolism functions (ecosystem metabolism and carbon dioxide (CO2) emission fluxes) using mesocosm experiments. Our findings indicate that longer drought durations lead to reduced alpha diversity and community heterogeneity, tighter interdomain networks, and an increased role of stochastic processes in community assembly, with a discernible threshold at around 60 days. Concurrently, the biofilm transforms into a carbon sink following a drought period of 60 days, as evidenced by the transformation of CO2 emission fluxes from 633.25 ± 194.69 to −349.61 ± 277.79 mg m–2 h–1. Additionally, the partial least-squares path model revealed that the resilience of algal communities and network stability may drive biofilm’s transformation into a carbon sink, primarily through the heightened resilience of autotrophic metabolism. This study underscores the significance of the carbon contribution from intermittent rivers, as the shift in carbon metabolism functions with increasing droughts could lead to skewed estimations of current riverine carbon fluxes

Tuning the Deoxygenation of Bulk-Dissolved Oxygen in Copper

Using synchrotron-based ambient-pressure X-ray photoelectron spectroscopy, we report the tuning of the deoxygenation process of bulk dissolved oxygen in copper via a combination of H₂ gas flow and elevated temperature. We show that a critical temperature of ∼580 °C exists for driving segregation of bulk dissolved oxygen to form chemisorbed oxygen on the Cu surface, which subsequently reacts with hydrogen to form OH species and then H₂O molecules that desorb from the surface. This deoxygenation process is tunable by a progressive stepwise increase of temperature that results in surface segregation of oxygen from deeper regions of bulk Cu. Using atomistic simulations, we show that the bulk-dissolved oxygen occupies octahedral sites of the Cu lattice and the deoxygenation process involves oxygen migration between octahedral and tetrahedral sites with a diffusion barrier of ∼0.5 eV

In Situ Monitoring of H₂‑Induced Nonstoichiometry in Cu₂O

Using ambient-pressure X-ray photoelectron spectroscopy and Auger electron spectroscopy to monitor the reduction of Cu2O in H2, we identify the formation of an intermediate, oxygen-deficient Cu2O phase and its progressive inward growth into the deeper region of the oxide. Complemented by atomistic modeling, we show that the oxygen-deficient Cu2O formation occurs via molecular H2 adsorption at the Cu2O surface, which results in the loss of lattice oxygen from the formation of H2O molecules that desorb spontaneously from the oxide surface. The resulting oxygen-deficient Cu2O is a stable intermediate that persists before the Cu2O is fully reduced to metallic Cu. The oxygen vacancy-induced charge of the coordinating Cu atoms results in a satellite feature in Cu LMM, which can be used as a fingerprint to identify nonstoichiometry in oxides and local charge transfer induced by the nonstoichiometry

DataSheet1_ACP-DRL: an anticancer peptides recognition method based on deep representation learning.PDF

Cancer, a significant global public health issue, resulted in about 10 million deaths in 2022. Anticancer peptides (ACPs), as a category of bioactive peptides, have emerged as a focal point in clinical cancer research due to their potential to inhibit tumor cell proliferation with minimal side effects. However, the recognition of ACPs through wet-lab experiments still faces challenges of low efficiency and high cost. Our work proposes a recognition method for ACPs named ACP-DRL based on deep representation learning, to address the challenges associated with the recognition of ACPs in wet-lab experiments. ACP-DRL marks initial exploration of integrating protein language models into ACPs recognition, employing in-domain further pre-training to enhance the development of deep representation learning. Simultaneously, it employs bidirectional long short-term memory networks to extract amino acid features from sequences. Consequently, ACP-DRL eliminates constraints on sequence length and the dependence on manual features, showcasing remarkable competitiveness in comparison with existing methods.</p

Effects of the Desiccation Duration on the Dynamic Responses of Biofilm Metabolic Activities to Rewetting

Global climate changes have increased the duration and frequency of river flow interruption, affecting the physical and community structure of benthic biofilms. However, the dynamic responses of biofilm metabolism during the dry–wet transition remain poorly understood. Herein, the dynamic changes in biofilm metabolic activities were investigated through mesocosm experiments under short-term (25 day) and long-term drought (90 day), followed by a 20 day rewetting. The biofilm ecosystem metabolism, as measured by gross primary production and community respiration, was significantly inhibited and turned heterotrophic during the desiccation phase and then recovered, becoming autotrophic during the rewetting period regardless of the desiccation periods due to the high resilience of the autotrophic community. However, long-term drought decreased the recovery rate of the ecosystem metabolism and also caused irreparable damage to the biofilm carbon metabolism, measured using Biolog Eco Plates. Specifically, the recovery of the total carbon metabolic activity is related to the specific carbon source utilized by biofilm microorganisms, such as polymers, carbohydrates, and carboxylic acids. However, the divergent changes of amino acids caused the failure of the total carbon metabolism in long-term drought treatments to recover to the control level even after 20 days of rewetting. This research provides direct evidence that the increased duration of non-flow periods affects biofilm-mediated carbon biogeochemical processes

Eukaryotes contribute more than bacteria to the recovery of freshwater ecosystem functions under different drought durations

Global climate change mostly impacts river ecosystems by affecting microbial biodiversity and ecological functions. Considering the high functional redundancy of microorganisms, the unknown relationship between biodiversity and ecosystem functions obstructs river ecological research, especially under the influence of increasing weather extremes, such as in intermittent rivers and ephemeral streams (IRES). Herein, dry–wet alternation experiments were conducted in artificial stream channels for 25 and 90 days of drought, both followed by 20 days of rewetting. The dynamic recovery of microbial biodiversity and ecosystem functions (represented by ecosystem metabolism and denitrification rate) were determined to analyse biodiversity–ecosystem–function (BEF) relationships after different drought durations. There was a significant difference between bacterial and eukaryotic biodiversity recovery after drought. Eukaryotic biodiversity was more sensitive to drought duration than bacterial, and the eukaryotic network was more stable under dry–wet alternations. Based on the establishment of partial least squares path models, we found that eukaryotic biodiversity has a stronger effect on ecosystem functions than bacteria after long-term drought. Indeed, this work represents a significant step forward for further research on the ecosystem functions of IRES, especially emphasizing the importance of eukaryotic biodiversity in the BEF relationship

Oxidative Cyclization of β‑Aminoacrylamides Mediated by PhIO: Chemoselective Synthesis of Isoxazoles and 2<i>H</i>‑Azirines

Cyclization of a variety of β-aminoacrylamides in the presence of iodosobenzene (PhIO) is described. This process features mild reaction conditions, simple execution, and high chemoselectivity and thereby provides an efficient protocol for the divergent synthesis of substituted isoxazoles and 2H-azirines via switchable N–O and N–C bond formation controlled by simply varying the β-substituent R3 of the readily available substrates

Oxidative Cyclization of β‑Aminoacrylamides Mediated by PhIO: Chemoselective Synthesis of Isoxazoles and 2<i>H</i>‑Azirines

Cyclization of a variety of β-aminoacrylamides in the presence of iodosobenzene (PhIO) is described. This process features mild reaction conditions, simple execution, and high chemoselectivity and thereby provides an efficient protocol for the divergent synthesis of substituted isoxazoles and 2H-azirines via switchable N–O and N–C bond formation controlled by simply varying the β-substituent R3 of the readily available substrates

Non-Photochemical Origin of Selectivity Difference between Light and Dark Catalytic Conditions

The interest in introducing light into heterogeneous catalysis is driven not only by the urgent need of replacing fossil energy but also by the promise of controlling product selectivity by light. The product selectivity differences observed in recent studies between light and dark reactions are often attributed to photochemical effects. Here, we report the discovery of a non-photochemical origin of selectivity difference, at essentially the same CO2 conversion rate, between photothermal and thermal CO2 hydrogenation reactions over a Ru/TiO2–x catalyst. While the presence of the photochemical effect from ultraviolet light is confirmed, it merely enhances the catalytic activity. Systematic investigation reveals that the gradual formation of an adsorbate-mediated strong metal–support interaction under catalytic conditions is responsible for the variation in the catalytic selectivity. We demonstrate that differences in product selectivity under light/dark reactions do not necessarily originate from photochemical effects. Our study refines the basis for determining photochemical effects and highlights the importance of excluding non-photochemical effects in mechanistic studies of light-controlled product selectivity