Attractive Alternative Research Articles

Broadband Photosensitive Medium Based on Amorphous Equichalcogenides

A photosensitive medium based on amorphous equichalcogenide thin films containing germanium and antimony is proposed with characteristics promising for applications in all-chalcogenide photonics, sensors, and photovoltaics. Optical properties, temperature, and exposure wavelength dependence of DC electrical conductivity are shown to be comparable with those for halide perovskites, which potentially makes amorphous equichalcogenides a very attractive alternative. The change in dark resistivity with temperature is found to follow exponential decay, covering 2 orders of magnitude over a 70 K temperature interval. Light exposure leads to several orders of relative changes in a current when compared to its dark value. A strong photocurrent response is observed under low power (milliwatts range) exposure across the entire 400–1000 nm range of the investigated wavelengths. An increase in temperature leads to a decrease in the photoresponse of the developed material, which is found to vanish at temperatures higher than 120 °C when only a few milliwatts of exposure power is used.

MYC regulates a pan-cancer network of co-expressed oncogenic splicing factors.

MYC is dysregulated in >50% of cancers, but direct targeting of MYC has been clinically unsuccessful. Targeting downstream MYC effector pathways represents an attractive alternative. MYC regulates alternative mRNA splicing, but the mechanistic links between MYC and the splicing machinery in cancer remain underexplored. Here, we identify a network of co-expressed splicing factors (SF-modules) in MYC-active breast tumors. Of these, one is a pan-cancer SF-module correlating with MYC activity across 33 tumor types. In mammary cell models, MYC activation leads to co-upregulation of pan-cancer module SFs and to changes in >4,000 splicing events. In breast cancer organoids, co-overexpression of the pan-cancer SF-module induces MYC-regulated splicing events and increases organoid size and invasiveness, while knockdown decreases organoid size. Finally, we uncover a MYC-activity pan-cancer splicing signature correlating with survival across tumor types. Our findings provide insight into the mechanisms of MYC-regulated splicing and for the development of therapeutics for MYC-driven tumors.

An overview of bioreactors and their application in biosorption of heavy metals

Atmospheric toxicants in the form of heavy metals are major threat to human species on earth. Heavy metalions are accumulative in nature and non-biodegradable. There minute amount in human body is verydangerous, henceforth there removal is necessary. Many physical and chemical methods like ion- exchange,ultra filtration, reverse osmosis, electrochemical treatment, chemical precipitation, evaporation, membranetechnologies are employed for remediation of heavy metals from wastewaters but due to some disadvantagesthere is a requirement of such bioremediation technology which should be environmental friendly and a natural method. Biosorption is one such method which is of great attractive alternative of conventionalmethods. Bioremediation technologies are now linked to bioreactors to make removal process more efficientfrom wastewater. Performance of some bioreactors is found to be very good for the removal of heavymetals through biosorption. So, one objective of this paper is to highlight the efficiency ofbiosorptioninvolved in bioreactors. Here we discuss different types of bioreactors fixed bed, fluidized bioreactor, stirredtank, airlift bioreactors which are being used for the biosorption process. This article alsohighlights thesignificance of standard bioreactors and a possible usage of nanoparticles based bioreactorswhich willdefinitely be very useful in near future. Further, green synthesis of nanoparticles is also aninterestingtechnology that will revolutionize the process of biosorption.

Comparability of in-person and web screening: Does mode affect what households report?

Household screening is common when information about characteristics of household members is needed for selection of survey respondents. When key characteristics have a low prevalence, or are oversampled, this can result in a large number of sampled households screened, many of which have no persons selected. For in-person surveys this can be inefficient and costly, especially in an environment of declining response. A multimode design using a mail, push-to-web approach is an attractive alternative due to lower cost and high internet penetration. However, little is known about the comparable data quality properties between in-person and web modes. While in-person screening is considered a gold standard approach, respondents may fail to report household members and interviewers may unintentionally screen out reluctant respondents. Similarly, those self-responding sometimes fail to report unrelated household members or young children. In this study we compared in-person and web screening in the National Health and Nutrition Examination Survey. Households were randomly selected to complete a self-administered web screener and subsequently be screened by an interviewer during an in-person visit. We report on the comparability of household characteristics between modes to determine if web screening provides data equivalent to in-person screening. We examine time between the web and in-person screening to see if true change can account for differences. In the presence of conflicting data, we examine selection criteria based on the screening responses to see how inaccuracies affect selection status, or if inaccuracies or person omissions are systematically related to a specific mode. Approximately 93% (80/86) of households agreed on selection status between the web and in-person modes. Household composition matched fully for 84% (72/86) of households. These results indicate that web screening is a viable option enumerating households in population surveys.

Orthodoxy and Socialism at the Beginning of the Twentieth Century: Struggle, Enthusiasm, Adaptation, Understanding

At the beginning of the twentieth century, industrialization led to a sharp increase in the number of industrial workers, which created problems for the Russian Church. The workers fundamentally differed in their mentality from the patriarchal flock familiar to the church and were influenced by socialist agitation, which was antigovernment and partly anti-church in nature. The main opponents for the church were the Social Democrats as an atheistic party based on European ideologues. Under these conditions, the struggle against social democracy became the mainstream course for the church, but this course proved ineffective due to the lack of attractive alternatives and the close connection of the church with the state. All other options — attempts to adapt to socialist agitation, sincere Christian socialism and the desire to differentiate socialism and socialists into unacceptable and relatively acceptable (without identification with them) — were peripheral to the church at that time. However, it is the latter option, which provided for the possibility of «coexistence» with socialists who have abandoned active atheism, that has now become the main one and is fixed in the «Fundamentals of the Social Concept» of the Russian Orthodox Church.

A cowpea severe mosaic virus-based vector simplifies virus-induced gene silencing and foreign protein expression in soybean

BackgroundSoybean gene functions cannot be easily interrogated through transgenic disruption (knock-out) of genes-of-interest, or transgenic overexpression of proteins-of-interest, because soybean transformation is time-consuming and technically challenging. An attractive alternative is to administer transient gene silencing or overexpression with a plant virus-based vector. However, existing virus-induced gene silencing (VIGS) and/or overexpression vectors suitable for soybean have various drawbacks that hinder their widespread adoption.ResultsWe describe the development of a new vector based on cowpea severe mosaic virus (CPSMV), a plus-strand RNA virus with its genome divided into two RNA segments, RNA1 and RNA2. This vector, designated FZ, incorporates a cloning site in the RNA2 cDNA, permitting insertion of nonviral sequences. When paired with an optimized RNA1 construct, FZ readily infects both Nicotiana benthamiana and soybean. As a result, FZ constructs destined for soybean can be first delivered to N. benthamiana in order to propagate the modified viruses to high titers. FZ-based silencing constructs induced robust silencing of phytoene desaturase genes in N. benthamiana, multiple soybean accessions, and cowpea. Meanwhile, FZ supported systemic expression of fluorescent proteins mNeonGreen and mCherry in N. benthamiana and soybean. Finally, FZ-mediated expression of the Arabidopsis transcription factor MYB75 caused N. benthamiana to bear brown leaves and purple, twisted flowers, indicating that MYB75 retained the function of activating anthocyanin synthesis pathways in a different plant.ConclusionsThe new CPSMV-derived FZ vector provides a convenient and versatile soybean functional genomics tool that is expected to accelerate the characterization of soybean genes controlling crucial productivity traits.

Poly(ε-caprolactone)-Based Graft Copolymers: Synthesis Methods and Applications in the Biomedical Field: A Review.

Synthetic biopolymers are attractive alternatives to biobased polymers, especially because they rarely induce an immune response in a living organism. Poly ε-caprolactone (PCL) is a well-known synthetic aliphatic polyester universally used for many applications, including biomedical and environmental ones. Unlike poly lactic acid (PLA), PCL has no chiral atoms, and it is impossible to play with the stereochemistry to modify its properties. To expand the range of applications for PCL, researchers have investigated the possibility of grafting polymer chains onto the PCL backbone. As the PCL backbone is not functionalized, it must be first functionalized in order to be able to graft reactive groups onto the PCL chain. These reactive groups will then allow the grafting of new reagents and especially new polymer chains. Grafting of polymer chains is mainly carried out by "grafting from" or "grafting onto" methods. In this review we describe the main structures of the graft copolymers produced, their different synthesis methods, and their main characteristics and applications, mainly in the biomedical field.

Modulating the Surface and Photophysical Properties of Carbon Dots to Access Colloidal Photocatalysts for Cross-Couplings

Photoredox-mediated Ni-catalyzed cross-couplings are powerful transformations to form carbon–heteroatom bonds and are generally photocatalyzed by noble metal complexes. Low-cost and easy-to-prepare carbon dots (CDs) are attractive quasi-homogeneous photocatalyst alternatives, but their applicability is limited by their short photoluminescence (PL) lifetimes. By tuning the surface and PL properties of CDs, we designed colloidal CD nano-photocatalysts for a broad range of Ni-mediated cross-couplings between aryl halides and nucleophiles. In particular, a CD decorated with amino groups permitted coupling to a wide range of aryl halides and thiols under mild, base-free conditions. Mechanistic studies suggested dynamic quenching of the CD excited state by the Ni co-catalyst and identified that pyridinium iodide (pyHI), a previously used additive in metallaphotocatalyzed cross-couplings, can also act as a photocatalyst in such transformations.

Disulfiram loaded calcium phosphate nanoparticles for enhanced cancer immunotherapy

Considering the huge cost and long test periods required for new drug development, repurposing drugs that have already been applied in the clinic as new cancer treatment candidates represents an attractive alternative. Disulfiram (DSF) was originally used to treat alcoholism and has proven to have anticancer effects with the coadministration of copper ions (Cu2+). However, the limited water-solubility of DSF and systemic toxicity induced by exogenous Cu2+ hinder its practical application. Herein, we constructed pH-responsive lipid-coated calcium phosphate nanoparticles (LCP NPs) co-loaded with Cu2+ and DSF. After intravenous injection, those nanoparticles with long blood half-life preferentially accumulate in tumors, followed by the degradation of nanoparticles in response to the acidic tumor microenvironment, subsequently releasing Cu2+ and DSF to generate cytotoxic metabolite DTC−Copper complex, bis(diethyldithiocarbamate)–copper (CuET) for tumor treatment. In addition to direct cytotoxicity, the active metabolite CuET could effectively induce immunogenic cell death (ICD) of cancer cells to regulate the immunosuppressive tumor microenvironment, contributing to enhanced immune checkpoint blockade (ICB) therapy in triggering systemic immune responses. This work thus demonstrates the great promises of repurposing the old drug DSF as a new ICD inducer with nano-formulation, to achieve improved synergetic tumor-responsive therapy with low side effects.

Improved interfacial performance of bamboo fibers/polylactic acid composites enabled by a self-supplied bio-coupling agent strategy

Natural fibers reinforced biopolymer composites (NFRBC) are attractive alternatives to petroleum-based plastics due to their renewability, carbon neutrality, and degradability. However, the incompatibility between the fibers and the polymer matrix has long been considered a challenging issue that prevents NFRBC from being widely used. The most common approach to overcome this problem is through surface modification of natural fibers, which always involve toxic or unsustainable reagents. Here, we focused on a cleaner and more sustainable strategy to address this issue. By using the deep eutectic solvent system, we successfully deposited a layer of lignin on the surface of the bamboo fibers to serve as a bio-coupling agent, self-supplied from the bamboo fibers rather than using exogenous lignin, petroleum-based coupling agents, or toxic reagents, which is more resource and energy efficient. The obtained bamboo fibers could simultaneously achieve interface compatibility enhancement and polylactic acid (PLA) matrix toughening. The PLA-based composites exhibited clearly better performance, including mechanical strength (the bending strength, tensile strength, impact strength, and elongation-at-break increased by 33.10%, 72.29%, 44.38%, and 40.80%, respectively), thermal stability (the Tonset increased from 290.6 °C to 331.9 °C), and water resistance (the water absorption decreased from 12% to 8%). Overall, with the self-supplied bio-coupling agent applied, this work suggests a new way toward developing more sustainable, stronger, and cleaner bio-composites.

Antibacterial peptide encapsulation and sustained release from chitosan-based delivery system

Antimicrobial peptides (AMPs) are a class of short polypeptides that are considered to be attractive future alternatives to traditional antibiotics for their wide sources, excellent antimicrobial properties and low drug resistance. However, AMPs are easily degraded, causing unstable antibacterial properties and a short effective time. Nanocarriers with good biocompatibility can improve the stability of AMPs, achieve sustained and stable release, and improve the bioavailability of AMPs. Herein, composite nanoparticles (NPs) prepared by ionic interaction between chitosan quaternary ammonium salt (HACC) and sodium dodecyl sulfate (SDS) were used as carriers for AMPs. The loading rate of NPs to AMP was over 80%. The AMP loaded in the particles had a longer antibacterial activity than the free AMP, and the NPs had good cell compatibility. The preparation method of particles is simple, pollution-free, and compound green chemistry concept. Moreover, it is convenient to load into various forms of biomedical materials, which is a promising carrier.

Probing patterning in microbial consortia with a cellular automaton for spatial organisation

Microbial consortia exhibit spatial patterning across diverse environments. Since probing the self-organization of natural microbial communities is limited by their inherent complexity, synthetic models have emerged as attractive alternatives. In this study, we develop novel frameworks of bacterial communication and explore the emergent spatiotemporal organization of microbes. Specifically, we built quorum sensing-mediated models of microbial growth that are utilized to characterize the dynamics of communities from arbitrary initial configurations and establish the effectiveness of our communication strategies in coupling the growth rates of microbes. Our simulations indicate that the behavior of quorum sensing-coupled consortia can be most effectively modulated by the rates of secretion of acyl homoserine lactones. Such a mechanism of control enables the construction of desired relative populations of constituent species in spatially organized populations. Our models accurately recapitulate previous experiments that have investigated pattern formation in synthetic multi-cellular systems. Additionally, our software tool enables the easy implementation and analysis of our frameworks for a variety of initial configurations and simplifies the development of sophisticated gene circuits facilitating distributed computing. Overall, we demonstrate the potential of spatial organization as a tunable parameter in synthetic biology by introducing a communication paradigm based on the location and strength of coupling of microbial strains.

In Vitro Efficacy Test on a Food Supplement for the Treatment of Urinary Tract Infections (UTIs)

Urinary tract infections (UTIs) are among the most common bacterial infections, representing a massive burden on healthcare systems and accounting for significant morbidity and healthcare expenditure. As bacteria generally cause UTIs, the primary therapy is defined by antibiotics, whose wide use can cause antibiotic resistance. In this scenario, using nutraceuticals to manage UTIs is an attractive alternative. This study aims to test the in vitro efficacy of a new food supplement for treating UTIs containing D-mannose, palmitoylethanolamide, HibCyn® (hibiscus extract), N-acetylcysteine and microencapsulated Lactobacillus rhamnosus LR04. The activity of the product was evaluated in terms of antimicrobial, antibiofilm, cytotoxic, antiinflammatory, and synergic activity with fosfomycin with respect to the main microorganisms responsible for UTIs, specifically Klebsiella pneumoniae, Enterococcus faecium, and Escherichia coli. “UTIVAL” food supplement has an action on both the inhibition and eradication of the biofilms formed by all the microorganisms. In the in vitro tests performed in this study, the activity of the product was effective at a concentration of 0.78 g/l. It was also possible to affirm that the product has an inhibiting effect on inflammation mediated by tumor necrosis factor αlfa (TNFα) in a concentration range of 0.04 to 0.625 mg/ml.

Design and Evaluation of Passenger Ferry Routes

This article introduces a planning framework for improving and best utilizing existing water and ferry resources. It presents an analysis framework and formulation for designing and evaluating passenger ferry routes. The motivation for this work emanates from problems encountered by the ferry service in Hong Kong, including the continuous loss in ferry patronage. This loss is believed to be caused by the ferry’s relatively poor level of service and intense competition from more attractive alternatives. The article reports on an evaluation and design methodology for the entire passenger ferry network, consisting of a framework with operational objective functions that takes into account passengers, operator, and community interests. This framework considers both the evaluation of existing ferry routes and the design of new ones. The methodology presented combines the philosophy of mathematical programming approaches and decision-making techniques, allowing the user to select an efficient solution from a number of alternatives. The evaluation procedure established provides practical and measurable criteria for evaluating the “goodness” of each route and for comparison between sets of routes at the network level.

Theoretical Study of Oxygen Reduction Reaction Mechanism in Metal-Free Carbon Materials: Defects, Structural Flexibility, and Chemical Reaction.

Metal-free carbon materials are attractive Pt-based catalyst alternatives. However, despite efforts, the reaction mechanism remains elusive. Thus, we investigated the role of defects (dopant nitrogen and carbon vacancy) on the catalytic oxygen reduction reaction in a metal-free carbon material focusing on the effect of structural flexibility. Crucially, defects lower the energy barrier for the sp2/sp3 transition of the carbon-centered O2-adsorption sites by releasing structural strain during the reaction. In particular, low-coordinated pyridinic-N displaces from the carbon plane to release the strain, whereas weak C-C bonds around the carbon vacancy change the bond lengths to release the strain. Defects indirectly promote the adsorption of oxygen by enhancing structural flexibility. Thus, the nonlocal structural environment is as critical as the direct interaction between adsorption sites and adsorbate in the chemical reaction. Molecular dynamics simulations reveal that pyridinic-N doping is a facile route to introduce stable catalytic active sites. Overall, our results provide a deeper understanding of chemical processes on defective carbon materials.

Accelerated dual dynamic integer programming applied to short-term power generation scheduling

The short-term generation scheduling (STGS) problem defines which units must operate and how much power they must deliver to satisfy the system demand over a planning horizon of up to two weeks. The problem is typically formulated as a large-scale mixed-integer linear programming problem, where off-the-shelf commercial solvers generally struggle to efficiently solve realistic instances of the STGS, mainly due to the large-scale of these models. Thus, decomposition approaches that break the model into smaller instances that are more easily handled are attractive alternatives to directly employing these solvers. This paper proposes a dual dynamic integer programming (DDiP) framework for solving the STGS problem efficiently. As in the standard DDiP approach, we use a nested Benders decomposition over the time horizon but introduce multiperiod stages and overlap strategies to accelerate the method. Simulations performed on the IEEE-118 system show that the proposed approach is significantly faster than standard DDiP and can deliver near-optimal solutions.

Current status and outlook of potential applications of biodegradable materials in cerebral vascular stents.

The treatment of intracranial aneurysms (IAs) has undergone a very significant transformation in recent decades, and endovascular interventions have gradually become one of the most common treatments. As permanent metal stents can cause some degree of long-term damage to patients, biodegradable stent materials are emerging as attractive potential alternatives. By reviewing the current research status and the advantages and disadvantages of existing biodegradable biomaterials, this review expects to provide a valuable reference for subsequent research on biodegradable biomaterials.

Insights into the Electrochemical Hydrogenation of Phenol

Traditional thermochemical hydrogenation (TCH) methods that are used in the U.S. chemical and petroleum industries to produce value-added fuels are highly energy intensive. To achieve hydrogenation, they require high temperature and pressure, along with an external source of hydrogen that usually comes from methane reformation. Electrochemical hydrogenation (ECH) is an attractive alternative that replaces the thermal driving force with an applied electrical potential, allowing ECH to operate near ambient conditions. The participating hydrogen comes from the aqueous electrolyte solution rather than externally produced hydrogen. These features of ECH lower its energy demand compared to TCH and result in less greenhouse gas emissions. ECH is also promising for the utilization of biomass feedstocks and could be powered directly by renewable energy, further minimizing its environmental impact.Aromatic hydrocarbons are of interest as model compounds for lignocellulosic bio-oil [1]. The ECH of aromatic hydrocarbons proceeds with high faradaic efficiency (FE) at low overpotentials, however, the ECH turnover rate remains low at these potentials. There is no simple fix to this because any increase in overpotential to increase ECH rate will reduce the reaction FE due to competition with the hydrogen evolution reaction (HER). In this work we address the need for a more fundamental understanding of ECH systems to promote high turnover rates at low overpotentials. In phenol TCH, it is well known that the hydrogenation is limited by the formation/addition of surface adsorbed hydrogen. The current ECH literature draws on these TCH studies and assumes that phenol ECH is also limited by surface adsorbed hydrogen [2]. Thus, most ECH work is done is acidic media, where the kinetics of surface adsorbed hydrogen formation are fastest on platinum [3]. HER, however, is also faster on platinum in acidic media [4], making it more difficult to achieve high FE.Because of this limited scope of investigation, the impact of electrolyte chemistry, i.e. pH, on ECH kinetics has only been sparingly investigated. In this work, we investigate a new pathway for enhanced rates at low overpotentials, driven by the acid-base chemistry of reactants and using electrolyte pH to promote dissociative adsorption. By tailoring the electrolyte pH based on the pKa of the reactant molecule, we can lower the barrier associated with the first hydrogenation step, improving overall reaction kinetics. We demonstrate this effect with phenol ECH at various pH electrolyte on low-index single crystal electrodes using rotating disk electrode voltammetry and chrono-amperometry with product analysis. We report on the structural sensitivity, influence of pH and resulting electric field effects, and present new mechanistic insights for phenol ECH. With these insights we propose methods to promote higher ECH rates at lower overpotentials.

The Influence of Polar Functional Groups in Melt-Blended Polymers Used As New Solid Electrolytes for Lithium Batteries.

Following the COP26 Summit in November 2021, more than hundred countries pledged to reach zero-emission by 2070 at the latest and the major car manufacturers committed to selling only electric vehicles by 2040. Currently, lithium-ion batteries (LIBs) are among the most widely used storage systems because of their high energy and power densities and long lifespan.1 The early LIBs are composed of intercalation electrodes, electronically isolated by an ion-conducting organic liquid electrolyte. However, the use of liquid electrolytes presents some disadvantages – especially in regard to consumer safety – related to short-circuits and potential leakages of the flammable liquid solvent. Moreover, in the case of lithium metal batteries, the combination of a liquid electrolyte and a high-capacity lithium metal anode leads to the uncontrolled deposition of lithium during the reduction, forming dendrites between the electrodes. A promising way to avoid this instability and improve battery safety is to replace the liquid electrolyte with an ion-conducting solid electrolyte.2 Among them, solid polymer electrolytes (SPEs) represent one of the most attractive alternatives due to their capacity to effectively conduct ions and higher mechanical resistance than their liquid counterparts.3 An important criterion for selecting polymers for use in SPEs is their ability to dissolve lithium salts through polar functional groups. Salt dissolution results in the replacement of ion-ion interactions in the lithium salt, with ion-dipole interactions in the polymer. The transport mechanisms of these ion-conducting materials differ from those of liquid electrolytes. Cation transport in polymer involves two steps which are considered to be dissociated or not, depending on the model chosen (Arrhenius or Vogel-Tamman-Fulcher, respectively). The application of one of these models provides interesting information on the ionic mobility dynamics in SPEs and, in particular, on the interplay between ionic jumps and polymer chain mobility. According to previous studies, higher segmental motions in the amorphous phase of polymers mainly provide ionic transport, which explains the limited ionic conductivity of SPEs at ambient temperature (less than 10-5 S/cm).Another major limitation of SPEs is primarily related to their dual role as electrolyte and binder in composite electrodes, which requires contradictory requirements to be met. Indeed, SPEs must have both sufficient flexibility to allow good interfacial contact between the electrode components and sufficient rigidity to limit short circuits.Polymer blending has emerged as an economic and effective technique to develop new SPEs which may simultaneously combine properties of each polymer and control the intrinsic properties of the resulting blend by adjusting the formulation.4 Moreover, polymer blends can be obtained by a solvent-free processing method, which reduce SPE toxicity and production time and cost. However, polymer blending makes both the salt dissociation processes and the ionic transport more difficult to understand as both polymers can dissolve lithium salts with their polar groups. Each polymer has different ionic transport properties depending on its architecture and thermal properties. Currently, no systematic survey comparing the ability of polymers with various functional groups to dissolve lithium salts in blends has thus far been conducted.In this presentation, we will discuss the salt dissociation ability of polar functional groups in various polymer blend SPEs. These groups are limited to those that are most commonly present in SPEs : ether, nitrile, carbonate, ester, alcohol and amide.5 The blends presented have been obtained by extrusion, which allows the effect of solvents on salt/polymer interactions to be neglected. Coupled FTIR, EDX and 7Li NMR analyses allow the interactions between LiTFSI and the polymer blends to be determined with a good degree of certainty. Our original study combines experimental and theoretical approaches to determine effects of polymers’ lithium salt solvating ability on blend electrolyte properties. Finally, this survey highlights an ideal polymer couple with the most promising and complementary properties, usable as SPE for LIBs. Indeed, this blend presents encouraging properties, compared to single-polymer SPEs, such as higher ionic conductivities over a wide temperature range, as well as improved mechanical and thermal stability properties and cycling performances. References Xie, W., Liu, X., He, R., Li, Y., Gao, X., Li, X., Peng, Z., Feng, S., Feng, X. and Yang, S. Journal of Energy Storage 2020, 32, 101837.Chen, R., Qu, W., Guo, X., Li, L. and Wu, F. Materials Horizons 2016, 3, 487-516.Gray, F. M. Solid polymer electrolytes, VCH New Tork 1991.Caradant, L., Lepage, D., Nicolle, P., Prébé, A., Aymé-Perrot, D. and Dollé, M. ACS Applied Polymer Materials 2020, 4943-4951.Caradant, L., Verdier, N., Foran, G., Lepage, D., Prébé, A., Aymé-Perrot, D. and Dollé, M. ACS Applied Polymer Materials 2021. Figure 1

Influence of Hydrophobic Groups Attached to Amphipathic Polymers on the Solubilization of Membrane Proteins along with Their Lipids.

One of the biggest challenges in membrane protein (MP) research is to secure physiologically relevant structural and functional information after extracting MPs from their native membrane. Amphipathic polymers represent attractive alternatives to detergents for stabilizing MPs in aqueous solutions. The predominant polymers used in MP biochemistry and biophysics are amphipols (APols), one class of which, styrene maleic acid (SMA) copolymers and their derivatives, has proven particularly efficient at MP extraction. In order to examine the relationship between the chemical structure of the polymers and their ability to extract MPs from membranes, we have developed two novel classes of APols bearing either cycloalkane or aryl (aromatic) rings, named CyclAPols and ArylAPols, respectively. The effect on solubilization of such parameters as the density of hydrophobic groups, the number of carbon atoms and their arrangement in the hydrophobic moieties, as well as the charge density of the polymers was evaluated. The membrane-solubilizing efficiency of the SMAs, CyclAPols, and ArylAPols was compared using as models (i) two MPs, BmrA and a GFP-fused version of LacY, overexpressed in the inner membrane of Escherichia coli, and (ii) bacteriorhodopsin, naturally expressed in the purple membrane of Halobacterium salinarum. This analysis shows that, as compared to SMAs, the novel APols feature an improved efficiency at extracting MPs while preserving native protein-lipid interactions.