Diverse Substrates Research Articles

Photoinitiated chemical vapor deposition (piCVD) of composition tunable, ionically conductive hydrogels on diverse substrates

Ionically conductive hydrogels are finding prominence in a wide range of emerging devices and applications, including biopotential sensors, organic field effect transistors, biomedicine, and soft robotics. Traditionally, these gels are synthesized through solution-phase polymerization or solvent based swelling of a polymer network and then cast in place or adhered to an intended substrate after synthesis. These fabrication approaches place artificial limitations on the accessible chemical composition and ionic conductivity of the gels, and limit deployment of ionically conductive hydrogels in complex platforms. Here we present a modular method to create ionically conductive hydrogels on a variety of rigid, flexible, or filamentary substrates through a photoinitiated chemical vapor deposition (piCVD) process. First, a viscosity tunable precursor mixture of desired ionic composition and strength is created and coated onto a target substrate. Next, an acrylate film is grown directly on these coated substrates via piCVD. Since both the monomer and photoinitiator used during the piCVD process are miscible in the aqueous precursor mixture, polymerization occurs at both the surface of and within the precursor layer. Using this two-step strategy, we isolate a robust composite hydrogel with independently tunable ionic properties and physical structure. This method is compatible with most substrates and results in a conformal, persistent gel coating with excellent rehydration properties. Gels containing a variety of biocompatible salts can be accessed, without concomitant changes in physical structure and morphology. Ionic conductivities can be tuned between 1 × 10−5–0.03 S cm−1 by changing the ionic strength of the precursor mixture. Additionally, we show that the material retains its ion concentration and conductivity after washing. Finally, we deploy this material onto several different substrates and show that through this method the same gel can be manufactured in-place regardless of the intended substrate.

Diastereoselective Spirocyclization: Entry to Spirocyclic Diketopiperazines.

We report a novel approach to access spirocyclic compounds containing a diketopiperazine (DKP) motif fused on a pyrrolidine ring. The shared spirocyclic carbon is at the ketone oxidation state, bearing two carbon-nitrogen bonds, one of which is introduced stereoselectively during the cyclization event. The reaction proceeds through an acid-catalyzed cyclization of a pendent chiral aminoamide unit onto a 2,3-dehydroproline amide moiety with up to >98:2 diastereoselectivity. We have demonstrated the generality of this methodology and its applicability to access chemically diverse DKP-containing structures. The extent of stereoinduction and how it varies according to the bulkiness of the substituent on the pendent aminoamide is demonstrated through a diverse substrate set. This methodology gives access to an underexplored spirocyclic diketopiperazine motif that may be useful in identifying new bioactive molecules.

Anabolic and Catabolic Microbial Activity in Hydrocarbon-rich Sediments of Guaymas Basin

Guaymas Basin, located in the Gulf of California, Mexico, is a young marginal ocean basin with high sedimentation rates of >1 mm/year, active seafloor spreading, and steep geothermal gradients in its sediment. It hosts a unique microbial subseafloor biosphere as these conditions lead to thermal cracking of sedimentary organic matter and the production of bioavailable organic carbon compounds and hydrocarbons already at shallow depths. The abundance and diversity of potential microbial substrates raise the question of which substrates are being used for catabolic and anabolic microbial metabolism. We thus analyzed the microbial uptake of hydrocarbons and inorganic nitrogen using nanoscale secondary ion mass spectrometry (NanoSIMS) analysis after incubation with stable-isotope labeled substrates. Incubations were carried out with samples from two International Ocean Discovery Program (IODP) Exp. 385 drill sites. Site U1545 is characterized by undisturbed sedimentary strata and a temperature gradient of 225°C/km, whereas Site U1546 has experienced a sill intrusion at greater depth, below the cored interval. The intrusion led to temporary heating of the sediment, but a temperature gradient of 221°C/km indicates thermal equilibration with the surrounding sediment since sill emplacement. Incubations were carried out with 13C-benzene + 2H-hexadecane + 15NH4Cl or 13C-methane + 15NH4Cl at in-situ temperature (4-62°C) and pressure (25 MPa) for 42 days. Additionally, sulfate reduction rates (SRR) were measured by incubating the samples with four aliphatic hydrocarbons + four aromatic hydrocarbons or methane and radioisotope-labeled 35SO42- for 10 days, also at in-situ temperature and pressure. The NanoSIMS analyses reveal that a few samples showed detectable microbial assimilation of hydrocarbons. Nitrogen was significantly assimilated in some samples incubated with methane. The assimilation mostly occurred in samples from near the seafloor (2 and 44 meter below seafloor (mbsf)). Our results indicate that anaerobic microorganisms in Guaymas Basin take up measurable amounts of hydrocarbons and inorganic nitrogen even in the relatively short incubation time of 42 days. The results of the SRR measurements indicate that a mixture of hydrocarbons and methane increases the SRR in samples from near the seafloor (2 mbsf) and around the sulfate-methane transition zone (44 and 55 mbsf) but not in samples from greater depths. Our results show that anaerobic microorganisms in Guaymas Basin can use hydrocarbons for anabolic and catabolic metabolism in this extreme environment. Given the high abundance of various carbon compounds, nitrogen appears to be a limiting factor for cellular growth.

Polydopamine-Modified MXene-Integrated Poly(N-isopropylacrylamide) to Construct Ultrafast Photoresponsive Bilayer Hydrogel Actuators with Smart Adhesion.

In nature, living organisms, such as octopuses, cabrito, and frogs, have already evolved admirable adhesive abilities for better movement and predation in response to the surroundings. Inspired by biological structures, researchers have made enormous efforts in developing actuators that can respond to external stimuli, while such adhesive property is very desired, yet there is still limited research in responsive hydrogel actuators. Here, a bilayer actuator with high stretchability and robust interface bonding is presented, which has a smart adhesion and thermoreception function. The system consists of an adhesive passive layer copolymerized of amphoteric ([2-(methacryloyloxy) ethyl] dimethyl-(3-sulfopropyl), SBMA) and acrylic acid (AA), and an active layer hydrogel composed of poly(N-isopropylacrylamide) (PNIPAm) containing polydopamine-modified MXene (P-MXene) and calcium chloride (CaCl2). The coordination of carboxylate and Ca2+ at the interface of the two layers enhances the interfacial bonding from 14 to 30 N m-1, which facilitates withstanding large strain and preventing stratification. The resulting hydrogel actuator can bend approximately 360° in a mere 10 s, exhibiting excellent photothermal effect, a large angle bending deformation, and ultrafast photoresponsive ability. As a proof of concept, the photothermal actuators are programmed to present various shapes and grab objects. Importantly, the hydrogel actuator exhibits remarkable adhesion capabilities toward diverse substrates, with a maximum peel force of up to 280 N m-1. Relying on their own adhesion and the photoresponse properties, these flexible adhesion actuators show outstanding gripping capability, enabling them to grip and release objects of different shapes and weights. More interestingly, the hydrogel exhibits a smart adjustable adhesion capability at different temperatures, which enables it as a gripper to recognize temperature signals through real-time different feedback actions based on its own adhesion. This study presents innovative insights into biomimetic hydrogel actuators, providing new opportunities for developing intelligent soft robots with multiple functions.

Triple-defense design of multifunctional superhydrophilic surface with outstanding underwater superoleophobicity, anti-oil-fouling properties, and high transparency

Superhydrophilic surfaces with underwater superoleophobicity have attracted widely attention in various fields, especially in the frequent ocean oil-spill accidents and increasing industrial oil leakage environments. However, controlling the oil fouling properties on these superhydrophilic surfaces is challenging since the potential solutions to prevent oil fouling tend to interfere with optical transparency. To reconcile the conflict between anti-oil-fouling properties and transparency, a triple-defense designed strategy by integrating mussel-inspired polycation coating, colorless hydrogel, and mineralized amorphous inorganic materials is introduced to a surface guaranteed superhydrophilicity/underwater superoleophobicity, superior active anti-oil-fouling properties, and high transparency. Thanks to the triple-defense design strategy, a synergistic effect originating from the cooperation of third defense layer of polycation coating, second defense layer of hydrogel, and first defense layer of amorphous inorganic materials gives rise to the superior active anti-oil-fouling properties to this superhydrophilic surface, regardless of oils. Independent of the environment, the surface enables to be aggressively infused by water, thus active de-wetting of diverse oils from the surfaces upon water action. The colorless organic coating and amorphous inorganic materials gives rise to the high underwater transparency. This substrate-independent multifunctional coating can be decorated on diverse substrates, allowing it used in various fields, such as oily wastewater treatment, anti-fogging, and underwater optical devices.

Interactive effects of microbial functional diversity and carbon availability on decomposition – A theoretical exploration

Microbial functional diversity in litter and soil has been hypothesized to affect the rate of decomposition of organic matter and other soil ecosystem functions. However, there are no clear theoretical expectations on how these effects might change with substrate availability, heterogeneity in the substrate chemistry, and different aspects of functional diversity itself (number of microbial groups vs. distribution of functional traits). To explore how these factors shape the decomposition-diversity relation, we carry out numerical experiments using a flexible reaction network comprising microbial processes and interactions with bioavailable carbon (extracellular degradation, uptake, respiration, growth, and mortality), and ecological processes (competition among the different groups). We also considered diverse carbon substrates, in terms of varying nominal oxidation state of carbon (NOSC). The reaction network was used to test the effects of (i) number of microbial groups, (ii) number of carbon pools, (iii) microbial functional diversity, and (iv) amount of bioavailable carbon. We found that the decomposition rate constant increases with increasing substrate concentration and heterogeneity, as well as with increasing microbial functional diversity or variance of microbial traits, albeit these biological factors are less important. The multivariate dependence of the decomposition rate constant (and other decomposition and microbial growth metrics) on substrate and microbial factors can be described using power laws with exponents lower than one, indicating that diversity effects on decomposition and microbial growth are reduced at high substrate concentration and heterogeneity, or at high microbial diversity.

Synthesis of α-Seleno Boronates via Diboration of Carbonyl Compounds.

A method has been described for accessing α-seleno alkyl boronates. The selenoboration was achieved via the diboration of carbonyl compounds to give α-oxyl boronates, which then undergo 1,2-metalate rearrangement in the presence of lithium selenolates and trifluoroacetic anhydride (TFAA). A variety of structurally diverse substrates were compatible with this protocol and efficiently provides difunctionalized products from simple starting materials. The presence of the boronic ester in the resulting organoselenium compounds serves as a versatile synthetic handle for various functionalizations. Mechanistic studies revealed that the binding of selenium nucleophile to both the boron centers in α-oxyl boronate esters.

Prostate Cancer Progression Relies on the Mitotic Kinase Citron Kinase.

The poorly characterized protein kinase citron kinase is a therapeutic target in prostate cancer that drives tumor growth by regulating diverse substrates, which control several hallmarks of aggressive prostate cancer progression. See related commentary by Mishra et al., p. 4008.

Facile Synthesis of Electrically Conductive Membranes.

A facile and effective strategy that can be used to fabricate electrically conductive membranes (ECMs) of diverse filtration performance (i.e., water productivity and solute rejection) is not available yet. Herein, we report a facile method that enables the fabrication of ECMs of a broad performance range. The method is based on the use of polyethylenimine (PEI), glutaraldehyde, and any of a diverse set of conductive materials to cast an electrically conductive layer atop any of a diverse set of substrates (i.e., from microfiltration to reverse osmosis membranes). We developed the reported ECM fabrication method using graphite as the conductive material and PVDF membranes as substrates. We demonstrate that graphite-PVDF ECMs were stable and electrically conductive and could be successfully used for solute filtration and electrochemical degradation. We also confirmed that the PEI/glutaraldehyde-based ECM fabrication method is suitable for conductive materials other than graphite, including carbon nanotubes, reduced graphene oxide, activated charcoal, and silver nanoparticles. Compared with the substrates used for their fabrication, ECMs showed low electrical sheet resistances that varied with conductive material, increased solute rejection, and reduced water permeance. Taken together, this work presents a promising general strategy for the fabrication of ECMs for environmental applications from diverse substrates and conductive materials.

Temporal Variation of Methanogenic Microbial Community in Palm Oil Mill Effluent (POME) Anaerobic Digester

Palm Oil Mill Effluents (POME) serve as suitable substrates for methane gas production through anaerobic digestion. This process relies on a complex microbial community that plays a critical role in ensuring stable anaerobic digester operation and efficient biogas production. Among these microorganisms, methanogenic archaea are pivotal in methane generation by utilizing diverse substrates under anoxic conditions. However, the knowledge of the microbial communities, particularly those involved in methane production in POME anaerobic sludge at different time intervals, remains limited. This study aims to uncover temporal variations in microbial communities, including diversity, composition, and structure, within POME anaerobic sludge, specifically focusing on the methanogenic archaea community. The temporal dynamics of microbial communities in the eighteen POME anaerobic sludge samples collected from a palm oil mill were investigated through 16S rRNA amplicon sequencing. The results reveal consistent microbial community diversity in POME anaerobic sludge over the study periods. Then, the sequencing also showed that Bacillota (26.9 ± 3.3%), Bacteroidota (20.2 ± 5.3%), and Chloroflexota (15.0% ± 6.3%) were the dominant bacterial phyla in POME anaerobic sludge across different time frames. Concurrently, Halobacteriota (5.9 ± 2.8%), Methanobacteriota (2.5 ± 0.6%), and Nanoarchaeota (2.3 ± 1.2%) were the primary archaeal phyla identified in anaerobic sludge at various time intervals. Furthermore, amplicon sequencing revealed the presence of two methanogenic archaea genera, Methanothrix and Methanobacterium, associated with acetoclastic and hydrogenotrophic methanogenesis, respectively. These findings suggest that acetoclastic and hydrogenotrophic methanogenesis pathways are the primary contributors to methane production in the POME anaerobic digestion process.

Multifunctional liquid-like magnetic nanofluids mediated coating with anticorrosion and self-healing performance

The long-term protective efficacy of organic coatings against corrosion can be diminished by the presence of micropores/cracks and poor self-healing capabilities. To address these issues, Ti3C2 MXene was subjected to liquefaction-like treatment to maintain a two-dimensional lamellar structure in water and polymer matrix for a long time, as well as improve the dispersion stability and loading capacity of MXene. The inorganic corrosion inhibitor ferroferric oxide (Fe3O4) was then electrostatically loaded onto MXene nanofluids to obtain a hybrid material. Through hydrogen bonding, polyvinyl alcohol (PVA) molecular chains were bridged to the hybrid material, resulting in a self-healing anti-corrosion coating. The coating exhibited excellent corrosion protection, as well as self-healing properties attributed to the labyrinth effect and corrosion inhibition of MXene@Fe3O4 hybrids. Notably, electrochemical testing demonstrated outstanding corrosion resistance of this coating on diverse substrate surfaces. In addition, the anti-corrosion coating will strongly coalesce on the surface of B-NdFeB under magnetic stimulation, realizing the localized corrosion protection of metal materials. The anti-corrosion coating can be quickly repaired under the stimulation of water as well as recovery, the anti-corrosion repair efficiency on the surface of permanent magnets is up to 92%, and the mechanical properties after recovery can be restored to 97% of the original sample. This innovative coating offers a convenient, green synthesis strategy for the construction of self-healing coatings with superior anti-corrosion properties.

The roles of intracellular proteolysis in cardiac ischemia-reperfusion injury.

Ischemic heart disease remains a leading cause of human mortality worldwide. One form of ischemic heart disease is ischemia-reperfusion injury caused by the reintroduction of blood supply to ischemic cardiac muscle. The short and long-term damage that occurs due to ischemia-reperfusion injury is partly due to the proteolysis of diverse protein substrates inside and outside of cardiomyocytes. Ischemia-reperfusion activates several diverse intracellular proteases, including, but not limited to, matrix metalloproteinases, calpains, cathepsins, and caspases. This review will focus on the biological roles, intracellular localization, proteolytic targets, and inhibitors of these proteases in cardiomyocytes following ischemia-reperfusion injury. Recognition of the intracellular function of each of these proteases includes defining their activation, proteolytic targets, and their inhibitors during myocardial ischemia-reperfusion injury. This review is a step toward a better understanding of protease activation and involvement in ischemic heart disease and developing new therapeutic strategies for its treatment.

Oxidoreductase enzymes: Characteristics, applications, and challenges as a biocatalyst.

Oxidoreductases are enzymes with distinctive characteristics that favor their use in different areas, such as agriculture, environmental management, medicine, and analytical chemistry. Among these enzymes, oxidases, dehydrogenases, peroxidases, and oxygenases are very interesting. Because their substrate diversity, they can be used in different biocatalytic processes by homogeneous and heterogeneous catalysis. Immobilization of these enzymes has favored their use in the solution of different biotechnological problems, with a notable increase in the study and optimization of this technology in the last years. In this review, the main structural and catalytical features of oxidoreductases, their substrate specificity, immobilization, and usage in biocatalytic processes, such as bioconversion, bioremediation, and biosensors obtainment, are presented.

Water-Induced Phase Separation for Anti-Swelling Hydrogel Adhesives in Underwater Soft Electronics.

The development of hydrogel-based underwater electronics has gained significant attention due to their flexibility and portability compared to conventional rigid devices. However, common hydrogels face challenges such as swelling and poor underwater adhesion, limiting their practicality in water environments. Here, a water-induced phase separation strategy to fabricate hydrogels with enhanced anti-swelling properties and underwater adhesion is presented. By leveraging the contrasting affinity of different polymer chains to water, a phase-separated structure with rich hydrophobic and dilute hydrophilic polymer phases is achieved. This dual-phase structure, meticulously characterized from the macroscopic to the nanoscale, confers the hydrogel network with augmented retractive elastic forces and facilitates efficient water drainage at the gel-substrate interface. As a result, the hydrogel exhibits remarkable swelling resistance and long-lasting adhesion to diverse substrates. Additionally, the integration of carboxylic multiwalled carbon nanotubes into the hydrogel system preserves its anti-swelling and adhesion properties while imparting superior conductivity. The conductive phase-separated hydrogel exhibited great potential in diverse underwater applications, including sensing, communication, and energy harvesting. This study elucidates a facile strategy for designing anti-swelling underwater adhesives by leveraging the ambient solvent effect, which is expected to offer some insights for the development of next-generation adhesive soft materials tailored for aqueous environments.

All‐Screen‐Coatable Photo‐Thermoelectric Imagers for Physical and Thermal Durability Enhancement

AbstractCarbon nanotube (CNT) film photo‐thermoelectric (PTE) imagers are suitable for non‐destructive inspection techniques owing to their functionalities. Simultaneously, their practical application remains a crucial bottleneck due to low yield handling in the device fabrication (e.g., disconnections between photo absorbent channels and readout electrodes). However, studies clarifying the above malfunction mechanism and associated dominant factors in device handling, such as specific fabrication or material selection steps, still need to be completed. To address this issue, this work introduces all‐screen‐coatable fabrication techniques for CNT film PTE imagers to enhance their physical and thermal durabilities. First, this work determined that the transfer of CNT films on supporting substrates dominantly governs the mechanical robustness of the channels and that thermal curing in the subsequent fabrication process is an essential factor in the yields of channel‐electrode connections. The proposed approach ensures a transfer‐free direct coating of the CNT film on diverse substrates and is sufficiently durable against thermal curing‐induced disconnections at the channel‐electrode interfaces. The screen‐coating technique is also available for whole device materials of solution‐processable CNT film PTE imagers, simplifying fabrication processes. All‐screen‐coatable CNT film PTE imagers synergize their inherent functional sensing and high‐yield operations toward versatile applications.

A simple and universal strategy for liquid-like coating suitable for a broad range of liquids on diverse substrates

A simple and universal strategy for liquid-like coating suitable for a broad range of liquids on diverse substrates

Exploring the "misfolding problem" by systematic discovery and analysis of functional-but-degraded proteins.

In both health and disease, the ubiquitin-proteasome system (UPS) degrades point mutants that retain partial function but have decreased stability compared with their wild-type counterparts. This class of UPS substrate includes routine translational errors and numerous human disease alleles, such as the most common cause of cystic fibrosis, ΔF508-CFTR. Yet, there is no systematic way to discover novel examples of these "minimally misfolded" substrates. To address that shortcoming, we designed a genetic screen to isolate functional-but-degraded point mutants, and we used the screen to study soluble, monomeric proteins with known structures. These simple parent proteins yielded diverse substrates, allowing us to investigate the structural features, cytotoxicity, and small-molecule regulation of minimal misfolding. Our screen can support numerous lines of inquiry, and it provides broad access to a class of poorly understood but biomedically critical quality-control substrates.

Pd-Catalyzed Regioselective (Markovnikov) Addition of Aryl Boronic Acids to Terminal Alkynes of 1,3-Dicarbonyl Compounds and Cyclization/Debenzoylation of Olefinic Dicarbonyl: Access to Arylated Pyran and (E)-4-Methylene-1,6-diphenylhex-5-en-1-one.

This Letter outlines palladium-catalyzed regioselective (Markovnikov's) addition of aryl boronic acids to propargyl 1,3-dicarbonyl alkyne to accomplish olefinic/diene 1,3-dicarbonyl compounds without the need for water workup. This methodology showcases remarkable performance with wide-ranging substrate diversity, achieving high yields while employing merely 3 mol % [Pd] alongside a mild KOAc base. Moreover, the utility of dicarbonyl olefins is exemplified through their application in intramolecular cyclization and debenzoylation reactions to access valuable trisubstituted pyran building blocks and (E)-4-methylene-1,6-diphenylhex-5-en-1-one synthesis.

Tough Yet Reversible Hydrogel Adhesives with Cooperative Energy Dissipation for Multifunctional Wearable Sensors

AbstractAchieving robust yet reversible adhesion between hydrogels and diverse substrates is of great importance and technically challenging. A family of phase‐segregated hydrogel adhesives with cooperative energy dissipation is reported. The resultant hydrogels display abundant nano‐aggregates comprising hydrophobic clusters and hydrogen‐bonded nanocrystals for efficient dissipation, and accumulated interfacial physical bonding like hydrogen bonding and hydrophobic interactions for intrinsic adhesion work, thus synergistically leading to super tough yet reversible adhesion. Additionally, the size of nano‐aggregates can be well‐tuned by varying time of solvent exchange followed by dry‐annealing and swelling, thus enabling switchable mechanical robustness and water content as well as unprecedented interfacial toughness exceeding 3300 J m−2 on the polyhydric surfaces. Multifunctional stretchable and pressure sensors with high sensitivity and ionic conductivity are also demonstrated.

Population structure and density of a new invasive species Rangia cuneata in the Szczecin Lagoon (Odra/Oder estuary, Poland)

The native North American bivalve species Rangia cuneata was unintentionally introduced into European waters during the first decade of the 21st century. In the Baltic Sea, it is mostly found along the southeastern coast, but in 2018 researchers also discovered the species in the Bay of Pomerania, which indicated that it could eventually inhabit the adjacent Szczecin Lagoon and Odra River. In 2021, the species was discovered for the first time in the Szczecin Lagoon during a sampling campaign, at 5 out of the 12 dispersed study sites with diverse bottom substrates. The goal of this study was to ascertain R. cuneata population density, morphometric parameters, individual growth, and the potential for further expansion in the southern Baltic Sea waters. For the study, 201 individuals of this species were collected. Compared to other sites in the southeast Baltic, the Szczecin Lagoon had a much lower average R. cuneata population density, at 13.2 ± 7.11 individuals m-2 of the bottom area. The highest population density was found at sites with more silt (4–63 µm) and less sand (>63 µm). R. cuneata shells had an average length of 30.9 ± 4.6 mm and an average weight of 6.6 ± 2.8 g. The collected specimens were greater in size than other populations of the species in the Baltic Sea and were comparable in size to populations from the nearby Bay of Pomerania. There were no specimens that were under 10 mm in length, and the population was dominated by specimens in the 25–30 mm and 30–35 mm ranges, as well as the 3+ and 4+ age groups. Given the R. cuneata’s invasive potential and its fast rate of colonization of new areas, it would be prudent to monitor this population and the species migration patterns across the estuary waters of the western Baltic.