Weak Selection Research Articles

Do flower-colonizing microbes influence floral evolution? A test with fast-cycling Brassica.

Pollinators are thought to be the main drivers of floral evolution. Flowers are also colonized by abundant communities of microbes that can affect the interaction between plants and their pollinators. Very little is known, however, about how flower-colonizing microbes influence floral evolution. Here we performed a 6-generation experimental evolution study using fast-cycling Brassica rapa, in which we factorially manipulated the presence of pollinators and flower microbes to determine how pollinators and microbes interact in driving floral evolution. We measured the evolution of 6 morphological traits, as well as the plant mating system and flower attractiveness. Only one of the 6 traits (flower number) evolved in response to pollinators, while microbes did not drive the evolution of any trait, nor did they interact with pollinators in driving the evolution of morphological traits. Moreover, we did not find evidence that pollinators or microbes affected the evolution of flower attractiveness to pollinators. However, we found an interactive effect of pollinators and microbes on the evolution of autonomous selfing, a trait that is expected to evolve in response to pollinator limitations. Overall, we found only weak evidence that microbes mediate floral evolution. However, our ability to detect an interactive effect of pollinators and microbes might have been limited by weak pollinator-mediated selection in our experimental setting. Our results contrast with previous (similar) experimental evolution studies, highlighting the susceptibility of such experiments to drift and to experimental artefacts.

Reversions mask the contribution of adaptive evolution in microbiomes.

When examining bacterial genomes for evidence of past selection, the results obtained depend heavily on the mutational distance between chosen genomes. Even within a bacterial species, genomes separated by larger mutational distances exhibit stronger evidence of purifying selection as assessed by , the normalized ratio of nonsynonymous to synonymous mutations. Here, we show that the classical interpretation of this scale-dependence, weak purifying selection, leads to problematic mutation accumulation when applied to available gut microbiome data. We propose an alternative, adaptive reversion model with exactly opposite implications for dynamical intuition and applications of . Reversions that occur and sweep within-host populations are nearly guaranteed in microbiomes due to large population sizes, short generation times, and variable environments. Using analytical and simulation approaches, we show that adaptive reversion can explain the decay given only dozens of locally-fluctuating selective pressures, which is realistic in the context of Bacteroides genomes. The success of the adaptive reversion model argues for interpreting low values of obtained from long-time scales with caution, as they may emerge even when adaptive sweeps are frequent. Our work thus inverts the interpretation of an old observation in bacterial evolution, illustrates the potential of mutational reversions to shape genomic landscapes over time, and highlights the importance of studying bacterial genomic evolution on short time scales.

Two-stage many-objective evolutionary algorithm: enhanced dominance relations and control mechanisms for separated balance

Although the multiobjective evolutionary algorithms (MOEAs) have been proved to bring promising prospects for solving multiobjective optimization problems (MOPs), the performance of the algorithm deteriorates sharply in high-dimensional objective space due to the weak selection pressure and the unregulated balance, which is caused by the increase of objective space dimension. Some current MOEAs with two-stage strategy (TS) strive to address above issues by dividing the evolutionary process into two independent stages, in which convergence and diversity are handled separately within successive generations of different stages. However, TS-MOEAs have some weaknesses, such as sensitivity to stage division, and incomplete separation of convergence and diversity. In this paper, TS/KW-MaOEA is proposed for solving many-objective optimization problems (MaOPs), which keeps TS as the central and equips a perfect control mechanism for separated balance. More specifically, TS/KW-MaOEA can automatically adjust the balance trend and provide appropriate selection pressure for MaOPs according to the Kondratiev wave (KW) search model and the objective space dimension. To verify the effectiveness of the proposed algorithm, a series of experiments are carried out against seven state-of-the-art many-objective optimization algorithms on 15 benchmark problems with up to 30 objectives. Experimental results indicate that the proposed algorithm is highly competitive against peer competitors.

Consequences of partially recessive deleterious genetic variation for the evolution of inversions suppressing recombination between sex chromosomes1.

The evolution of suppressed recombination between sex chromosomes is widely hypothesized to be driven by sexually antagonistic selection (SA), where tighter linkage between the sex-determining gene(s) and nearby SA loci is favored when it couples male-beneficial alleles to the proto-Y chromosome, and female-beneficial alleles to the proto-X. Although difficult to test empirically, the SA selection hypothesis overshadows several alternatives, including an incomplete but often-repeated "sheltering" hypothesis which suggests that expansion of the sex-linked region (SLR) reduces the homozygous expression of deleterious mutations at selected loci. Here, we use population genetic models to evaluate the consequences of partially recessive deleterious mutational variation for the evolution of otherwise neutral chromosomal inversions expanding the SLR on proto-Y chromosomes. Both autosomal and SLR-expanding inversions face a race against time: lightly-loaded inversions are initially beneficial, but eventually become deleterious as they accumulate new mutations, after which their chances of fixing become negligible. In contrast, initially unloaded inversions eventually become neutral as their deleterious load reaches the same equilibrium as non-inverted haplotypes. Despite the differences in inheritance and indirect selection, SLR-expanding inversions exhibit similar evolutionary dynamics to autosomal inversions over many biologically plausible parameter conditions. Differences emerge when the population average mutation load is quite high; in this case large autosomal inversions that are lucky enough to be mutation-free can rise to intermediate to high frequencies where selection in homozygotes becomes important (Y-linked inversions never appear as homozygous karyotypes); conditions requiring either high mutation rates, highly recessive deleterious mutations, weak selection, or a combination thereof.

Weak purifying selection in allelic diversity of the ADSL gene in indigenous and local chicken breeds and red junglefowl in Thailand

High levels of purine and uric acid, which are associated with health issues such as gout and cardiovascular disease, are found in the meat of fast-growing broiler chickens, which raises concerns about the quality of chicken meat and the health of the consumers who consume it. High genetic homogeneity and uniformity, particularly in genes involved in the synthesis of inosine monophosphate (IMP) and subsequent process of purine synthesis, which are associated with the meat quality, are exhibited in commercial broiler chickens owing to intensive inbreeding programs. Adenosine succinate lyase (ADSL) is a key enzyme involved in de novo purine biosynthetic pathway and its genetic polymorphisms affect IMP metabolism and purine content. In this study, we investigated the polymorphism of the ADSL gene in indigenous and local chicken breeds and red junglefowl in Thailand, using metabarcoding and genetic diversity analyses. Five alleles with 73 single nucleotide polymorphisms in exon 2, including missense and silent mutations, which may act on the synthesis efficiency of IMP and purine. Their protein structures revealed changes in amino acid composition that may affect ADSL enzyme activity. Weak purifying selection in these ADSL alleles was observed in the chicken population studied, implying that the variants have minor fitness impacts and a greater probability of fixation of beneficial mutations than strong purifying selection. A potential selective sweep was observed in Mae Hong Son chickens, whose purine content was lower than that in other breeds. This suggests a potential correlation between variations of the ADSL gene and reduced purine content and an impact of ADSL expression on the quality of chicken meat. However, further studies are required to validate its potential availability as a genetic marker for selecting useful traits that are beneficial to human health and well-being.

Does Effective Population Size Govern Evolutionary Differences in Telomere Length?

Lengths of telomeres vary by an order of magnitude across mammalian species. Similarly, age- and sex-standardized telomere lengths differ by up to 1 kb (14%) across human populations. How to explain these differences? Telomeres play a central role in senescence and aging, and genes that affect telomere length are likely under weak selection (i.e. telomere length is a trait that is subject to nearly neutral evolution). Importantly, natural selection is more effective in large populations than in small populations. Here, we propose that observed differences in telomere length across species and populations are largely due to differences in effective population sizes. In this perspective, we present preliminary evolutionary genetic evidence supporting this hypothesis and highlight the need for more data.

Abstract PO2-10-08: Contemporary HER2-Positive MBC Treatment Recommendations Among Community Healthcare Professionals: Analysis of an Online Interactive Decision Support Tool

Abstract Background: The management of HER2-positive (HER2+) metastatic breast cancer (MBC) has continued to evolve, with multiple FDA approvals of novel HER2-targeted agents since late 2019. Considering the growing HER2+ MBC treatment armamentarium, we sought to identify current practice patterns among community healthcare professionals (HCPs) for HER2+ MBC by comparing HCP and key opinion leader (KOL) treatment recommendations using an online decision support tool. Methods: An online decision support tool was developed with input from 5 KOLs to provide therapy recommendations for 630 HER2+ MBC patient case scenarios based on conventional considerations including distribution of metastatic disease, treatment history, duration of response, and specific comorbidities. HCP tool users entered specific patient criteria to define a case along with their intended management for each case. The tool then showed 5 KOL recommendations for the user-entered patient case, and the users were asked to indicate if the expert recommendations confirmed or changed their intended approach. An analysis of expert recommendations and user-selected therapy was performed. Results: Between November 2022 and July 2023, 313 patient cases were entered by 242 participating HCPs. HCP and KOL treatment recommendations were frequently discordant (Table). For patients with de novo HER2+ MBC (n = 55), there was strong concordance (63%; P = .0001) between HCP and KOL recommendations. However, weak treatment selection concordance (53%; P < .0001) was observed for patients with disease progression after standard neoadjuvant/adjuvant therapy with chemotherapy plus HER2-targeted agents (n = 57). In the second-line setting, 43% concordance was observed for patients with non‒central nervous system (CNS) disease progression without CNS progression after first-line therapy with THP (n = 67; P < .0001), whereas 61% concordance was observed for patients with non-CNS and CNS disease progression after first-line therapy with THP (n = 61; P < .0001). In the third-line setting, 31% concordance was observed for patients with non-CNS disease progression without CNS progression (n = 32; P < .0001), and 47% concordance was observed for patients with non-CNS and CNS disease progression (n = 19; P = .0009). For HCPs whose treatment plan did not match KOL recommendations in these scenarios, 62% indicated that KOL recommendations confirmed or changed their intended therapy, but 19% indicated that there were barriers to implementing those recommendations. Conclusions: These data suggest ongoing challenges to optimally incorporate novel HER2-targeted therapies in the care of patients with HER2+ MBC, particularly in the second line and beyond, but an online tool providing KOL advice on specific patient scenarios confirmed or changed the clinical approach for a majority of HCPs. Thus, continued development of resources for HCPs, including online decision support tools, may be increasingly important given the rapidly evolving treatment landscape. Table. Summary of Treatment Choices by KOLs or HCPs for Select Patient Scenarios Citation Format: Kristen Rosenthal, Sara Hurvitz, Komal Jhaveri, Heather McArthur, Sara Tolaney, Timothy Quill. Contemporary HER2-Positive MBC Treatment Recommendations Among Community Healthcare Professionals: Analysis of an Online Interactive Decision Support Tool [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-10-08.

Deterministic theory of evolutionary games on temporal networks.

Recent empirical studies have revealed that social interactions among agents in realistic networks merely exist intermittently and occur in a particular sequential order. However, it remains unexplored how to theoretically describe evolutionary dynamics of multiple strategies on temporal networks. Herein, we develop a deterministic theory for studying evolutionary dynamics of any [Formula: see text] pairwise games in structured populations where individuals are connected and organized by temporally activated edges. In the limit of weak selection, we derive replicator-like equations with a transformed payoff matrix characterizing how the mean frequency of each strategy varies over time, and then obtain critical conditions for any strategy to be evolutionarily stable on temporal networks. Interestingly, the re-scaled payoff matrix is a linear combination of the original payoff matrix with an additional one describing local competitions between any pair of different strategies, whose weights are solely determined by network topology and selection intensity. As a particular example, we apply the deterministic theory to analysing the impacts of temporal networks in the mini-ultimatum game, and find that temporally networked population structures result in the emergence of fairness. Our work offers theoretical insights into the subtle effects of network temporality on evolutionary game dynamics.

Cu-based nano-material catalysts for electrochemical carbon dioxide reduction reaction (CO2RR)

With the emergence of the global energy crisis and global climate change, renewable energy systems, such as fuel cells that turn off energetic oxygen and carbon cycles, are becoming increasingly important. Carbon dioxide reduction reaction (CO_2 RR) is an important electrocatalytic process on the gas diffusion electrode of CO_2 electrolyzer, which has been paid more and more attention by researchers. The problems of high cost, low efficiency, weak selectivity and stability of the carbon dioxide reduction reaction (CO_2 RR) also continue to be solved. Catalysts are considered a viable way to solve these problems. The Cu-based nanomaterial catalyst has been proven to have a good positive effect on the reaction. In this paper, the current research results of Cu-based nanomaterials on CO_2 RR were reviewed, and the catalytic effects of several different Cu-based nanomaterials on CO_2 RR reactions were compared. This paper collected the researches on the catalytic effect of copper-based nanomaterials on carbon dioxide reduction reactions in the past ten years, and found that most copper-based nanomaterials can improve the efficiency of the reactions and show good selectivity. The aim of this paper is to provide a possible catalytic direction for the improvement of carbon dioxide reduction reactions in industry

Independent transitions to freshwater environments promote phenotypic divergence, not convergence, in stingrays.

Instances of convergent or parallel evolution provide a potent model system for exploring contingency and determinism in evolutionary biology. Likewise, the multiple, independent habitat transitions from saltwater to freshwater biomes offer opportunity for studying convergent evolution within and among different vertebrate lineages. For example, stingrays have invaded freshwater habitats multiple times across different continents, sometimes even several times within the same clade (e.g., Dasyatidae). We evaluated the frequency of saltwater-freshwater invasions in stingrays, compared ecological and phenotypic diversification among freshwater and saltwater lineages, and assessed the degree of convergence among freshwater species. Despite not being morphologically distinct from saltwater stingrays, freshwater stingrays do expand the margins of stingray morphological diversity. According to our data, trophic specialists occupied non-overlapping regions of morphospace, with piscivores and molluscivores being distinct from other diet guilds. Freshwater stingrays as a group did not strongly converge morphologically, neither did freshwater rays from different lineages which shared similar niches. These findings could be explained by there not being enough time for convergence to occur among more ancient and more recent freshwater lineages. Alternatively, the different ancestral bauplans of various freshwater ray lineages and weak selection on optimal phenotypes could promote contingency in the form of evolution along paths of least resistance.

Dual-Aptamer Recognition of DNA Logic Gate Sensor-Based Specific Exosomal Proteins for Ovarian Cancer Diagnosis.

Clinical diagnosis of ovarian cancer lacks high accuracy due to the weak selection of specific biomarkers along with the circumstance biomarkers localization. Clustering analysis of proteins transported on exosomes enables a more precise screening of effective biomarkers. Herein, through bioinformatics analysis of ovarian cancer and exosome proteomes, two coexpressed proteins, EpCAM and CD24, specifically enriched, were identified, together with the development of an as-derived dual-aptamer targeted exosome-based strategy for ovarian cancer screening. In brief, a DNA ternary polymer with aptamers targeting EpCAM and CD24 was designed to present a logic gate reaction upon recognizing ovarian cancer exosomes, triggering a rolling circle amplification chemiluminescent signal. A dynamic detection range of 6 orders of magnitude was achieved by quantifying exosomes. Moreover, for clinical samples, this strategy could accurately differentiate exosomes from healthy persons, other cancer patients, and ovarian cancer patients, enabling promising in situ detection. By accurately selecting biomarkers and constructing a dual-targeted exosomal protein detection strategy, the limitation of insufficient specificity of traditional protein markers was circumvented. This work contributed to the development of exosome-based prognosis monitoring in ovarian cancer through the identification of disease-specific exosome protein markers.

Pan-genome insights into adaptive evolution of bacterial symbionts in mixed host-microbe symbioses represented by human gut microbiota Bacteroides cellulosilyticus

Animal hosts harbor diverse assemblages of microbial symbionts that play crucial roles in the host's lifestyle. The link between microbial symbiosis and host development remains poorly understood. In particular, little is known about the adaptive evolution of gut bacteria in host–microbe symbioses. Recently, symbiotic relationships have been categorized as open, closed, or mixed, reflecting their modes of inter-host transmission and resulting in distinct genomic features. Members of the genus Bacteroides are the most abundant human gut microbiota and possess both probiotic and pathogenic potential, providing an excellent model for studying pan-genome evolution in symbiotic systems. Here, we determined the complete genome of an novel clinical strain PL2022, which was isolated from a blood sample and performed pan-genome analyses on a representative set of Bacteroides cellulosilyticus strains to quantify the influence of the symbiotic relationship on the evolutionary dynamics. B. cellulosilyticus exhibited correlated genomic features with both open and closed symbioses, suggesting a mixed symbiosis. An open pan-genome is characterized by abundant accessory gene families, potential horizontal gene transfer (HGT), and diverse mobile genetic elements (MGEs), indicating an innovative gene pool, mainly associated with genomic islands and plasmids. However, massive parallel gene loss, weak purifying selection, and accumulation of positively selected mutations were the main drivers of genome reduction in B. cellulosilyticus. Metagenomic read recruitment analyses showed that B. cellulosilyticus members are globally distributed and active in human gut habitats, in line with predominant vertical transmission in the human gut. However, existence and/or high abundance were also detected in non-intestinal tissues, other animal hosts, and non-host environments, indicating occasional horizontal transmission to new niches, thereby creating arenas for the acquisition of novel genes. This case study of adaptive evolution under a mixed host–microbe symbiosis advances our understanding of symbiotic pan-genome evolution. Our results highlight the complexity of genetic evolution in this unusual intestinal symbiont.

Dual-selective silver recovery strategy by simultaneous adsorption-reduction boosted by in-situ magnetic field

The mainstream silver recovery has problems such as resource waste, weak silver selectivity, and complicated operation. Here, self-propelled magnetic enhanced capture hydrogel (magnetic NbFeB/MXene/GO, MNMGH) was prepared by self-crosslinking encapsulation method. MNMGH achieved high selectivity (Kd = 23.31 mL/g) in the acidic range, and exhibited ultrahigh silver recovery capacity (1604.8 mg/g), which greatly improved by 66% with the assistance of in-situ magnetic field. The recovered silver crystals could be directly physically exfoliated, without acid/base additions. The selective sieving effect of adsorption, MNMGH preferentially adsorbed Ag(I), and then selectively reduced to Ag(0), realizing dual-selective recovery. The in-situ magnetic field enhanced selective adsorption by enhancing mass transfer, reactivity of oxygen-containing functional groups. Furthermore, density function theory simulations demonstrated that the in-situ magnetic field could lower the silver reduction reaction energy barrier to enhance the selective reduction. Three-drive synergy system (reduction drive, adsorption drive and magnetic drive) achieved ultrahigh silver recovery performance. This study pioneered an in-situ magnetic field assisted enhancement strategy for dual-selective (adsorption/reduction) recovery of precious metal silver, which provided new idea for low-carbon recovery of noble metal from industrial waste liquids.

Nonlinear social evolution and the emergence of collective action.

Organisms from microbes to humans engage in a variety of social behaviors, which affect fitness in complex, often nonlinear ways. The question of how these behaviors evolve has consequences ranging from antibiotic resistance to human origins. However, evolution with nonlinear social interactions is challenging to model mathematically, especially in combination with spatial, group, and/or kin assortment. We derive a mathematical condition for natural selection with synergistic interactions among any number of individuals. This result applies to populations with arbitrary (but fixed) spatial or network structure, group subdivision, and/or mating patterns. In this condition, nonlinear fitness effects are ascribed to collectives, and weighted by a new measure of collective relatedness. For weak selection, this condition can be systematically evaluated by computing branch lengths of ancestral trees. We apply this condition to pairwise games between diploid relatives, and to dilemmas of collective help or harm among siblings and on spatial networks. Our work provides a rigorous basis for extending the notion of "actor", in the study of social evolution, from individuals to collectives.

Resequencing of reindeer genomes provides clues to their docile habits.

Reindeer have long been served as vital subsistence resources for inhabitants of Arctic and subarctic regions owing to their domestication. However, the evolutionary relationships and divergence times among different reindeer populations, genetic traits that distinguish domesticated reindeer, and factors that contribute to their relative docility compared with that of other Cervidae specie, remain unclear. In this study, we sequenced the genomes of 32 individuals from wild and domestic reindeer populations that inhabit Arctic and subarctic regions. We found that reindeer experienced 2 or more independent domestication events characterized by weak artificial selection pressure and limited significant differences in genomic parameters between wild and domestic populations. Alterations in conserved noncoding elements in the reindeer genomes, particularly those associated with nervous system development, may have contributed to their domestication by rendering the nervous system less responsive. Together, our results suggest that inherent species-specific traits, rather than intense artificial selection, may have played a significant role in the relatively docile behavior of reindeer and offer valuable insights into the domestication process of these animals.

When selection pays: Structured public goods game with a generalized interaction mode.

The public goods game is a broadly used paradigm for studying the evolution of cooperation in structured populations. According to the basic assumption, the interaction graph determines the connections of a player where the focal actor forms a common venture with the nearest neighbors. In reality, however, not all of our partners are involved in every game. To elaborate this observation, we propose a model where individuals choose just some selected neighbors from the complete set to form a group for public goods. We explore the potential consequences by using a pair-approximation approach in a weak selection limit. We theoretically analyze how the number of total neighbors and the actual size of the restricted group influence the critical enhancement factor where cooperation becomes dominant over defection. Furthermore, we systematically compare our model with the traditional setup and show that the critical enhancement factor is lower than in the case when all players are present in the social dilemma. Hence, the suggested restricted interaction mode offers a better condition for the evolution of cooperation. Our theoretical findings are supported by numerical calculations.

Plasma‐oxidized 2D MXenes subnanochannel membrane for high‐performance osmotic energy conversion

AbstractNanofluidic channels inspired by electric eels open a new era of efficient harvesting of clean blue osmotic energy from salinity gradients. Limited by less charge and weak ion selectivity of the raw material itself, energy conversion through nanofluidic channels is still facing considerable challenges. Here, a facile and efficient strategy to enhance osmotic energy harvesting based on drastically increasing surface charge density of MXenes subnanochannels via oxygen plasma is proposed. This plasma could break Ti–C bonds in the MXenes subnanochannels and effectively facilitate the formation of more Ti–O, C═O, O–OH, and rutile with a stronger negative charge and work function, which leads the surface potential of MXenes membrane to increase from 205 to 430 mV. This significant rise of surface charge endows the MXenes membrane with high cation selectivity, which could make the output power density of the MXenes membrane increase by 248.2%, reaching a high value of 5.92 W m−2 in the artificial sea‐river water system. Furthermore, with the assistance of low‐quality heat at 50°C, the osmotic power is enhanced to an ultrahigh value of 9.68 W m−2, which outperforms those of the state‐of‐the‐art two‐dimensional (2D) nanochannel membranes. This exciting breakthrough demonstrates the enormous potential of the facile plasma‐treated 2D membranes for osmotic energy harvesting.

Prevalence of persistent SARS-CoV-2 in a large community surveillance study.

Persistent SARS-CoV-2 infections may act as viral reservoirs that could seed future outbreaks1-5, give rise to highly divergent lineages6-8 and contribute to cases with post-acute COVID-19 sequelae (long COVID)9,10. However, the population prevalence of persistent infections, their viral load kinetics and evolutionary dynamics over the course of infections remain largely unknown. Here, using viral sequence data collected as part of a national infection survey, we identified 381 individuals with SARS-CoV-2 RNA at high titre persisting for at least 30 days, of which 54 had viral RNA persisting at least 60 days. We refer to these as 'persistent infections' as available evidence suggests that they represent ongoing viral replication, although the persistence of non-replicating RNA cannot be ruled out in all. Individuals with persistent infection had more than 50% higher odds of self-reporting long COVID than individuals with non-persistent infection. We estimate that 0.1-0.5% of infections may become persistent with typically rebounding high viral loads and last for at least 60 days. In some individuals, we identified many viral amino acid substitutions, indicating periods of strong positive selection, whereas others had no consensus change in the sequences for prolonged periods, consistent with weak selection. Substitutions included mutations that are lineage defining for SARS-CoV-2 variants, at target sites for monoclonal antibodies and/or are commonly found in immunocompromised people11-14. This work has profound implications for understanding and characterizing SARS-CoV-2 infection, epidemiology and evolution.

Surface ligand-regulated nanointerfaces: Enhancing the catalytic activity and selectivity of platinum nanozymes for biomedical applications

Platinum nanoparticles (Pt NPs) have aroused tremendous attention due to the significant enzyme-like activity, controllable synthesis and biosafety. However, it remains a challenge to properly design the morphology and surface properties of Pt NPs to obtain the desired enzyme-like activity and substrate selectivity. Herein, a surface engineering strategy is employed to adjust the catalytic performance of Pt NPs by modifying different functional groups, thereby promoting its oxidase-like activity and catalytic specificity to substrate. The catalytic performance of Pt NPs with various thiolate ligands was evaluated using TMB, ABTS and OPD as substrates. The kcat/Km values revealed that Pt NPs modified by 6-mercapto-6-deoxybeta-cyclodextrin (Pt@CD) had a strong substrate selectivity for TMB, but a weak selectivity for ABTS and OPD, with a catalytic specificity to TMB nearly 3.4 times that of bare Pt NPs. When uric acid was used as substrate, PtNP_32 showed better environmental stability and uric acid degradation efficiency than uricase. More importantly, the PtNP_32 did not cause hemolysis and had good biocompatibility, making it a promising candidate for the treatment of hyperuricemia-related diseases. This work provides a new strategy to improve the catalytic performance of platinum nanozymes for efficient and selective degradation of uric acid.

The SARS-CoV-2 envelope protein channel displays weak selectivity and heterogeneous oligomerization

The SARS-CoV-2 envelope protein channel displays weak selectivity and heterogeneous oligomerization