A global phylogenomic analysis of the shiitake genus Lentinula.

Lentinula is a broadly distributed group of fungi that contains the cultivated shiitake mushroom, L. edodes. We sequenced 24 genomes representing eight described species and several unnamed lineages of Lentinula from 15 countries on four continents. Lentinula comprises four major clades that arose in the Oligocene, three in the Americas and one in Asia-Australasia. To expand sampling of shiitake mushrooms, we assembled 60 genomes of L. edodes from China that were previously published as raw Illumina reads and added them to our dataset. Lentinula edodes sensu lato (s. lat.) contains three lineages that may warrant recognition as species, one including a single isolate from Nepal that is the sister group to the rest of L. edodes s. lat., a second with 20 cultivars and 12 wild isolates from China, Japan, Korea, and the Russian Far East, and a third with 28 wild isolates from China, Thailand, and Vietnam. Two additional lineages in China have arisen by hybridization among the second and third groups. Genes encoding cysteine sulfoxide lyase (lecsl) and γ-glutamyl transpeptidase (leggt), which are implicated in biosynthesis of the organosulfur flavor compound lenthionine, have diversified in Lentinula. Paralogs of both genes that are unique to Lentinula (lecsl 3 and leggt 5b) are coordinately up-regulated in fruiting bodies of L. edodes. The pangenome of L. edodes s. lat. contains 20,308 groups of orthologous genes, but only 6,438 orthogroups (32%) are shared among all strains, whereas 3,444 orthogroups (17%) are found only in wild populations, which should be targeted for conservation.

The white rot basidiomycete Gelatoporia subvermispora produces fatty aldehydes that enable fungal manganese peroxidases to degrade recalcitrant lignin structures.

The ability of some white rot basidiomycetes to remove lignin selectively from wood indicates that low molecular weight oxidants have a role in ligninolysis. These oxidants are likely free radicals generated by fungal peroxidases from compounds in the biodegrading wood. Past work supports a role for manganese peroxidases (MnPs) in the production of ligninolytic oxidants from fungal membrane lipids. However, the fatty acid alkylperoxyl radicals initially formed during this process are not reactive enough to attack the major structures in lignin. Here, we evaluate the hypothesis that the peroxidation of fatty aldehydes might provide a source of more reactive acylperoxyl radicals. We found that Gelatoporia subvermispora produced trans-2-nonenal, trans-2-octenal, and n-hexanal (a likely metabolite of trans-2,4-decadienal) during the incipient decay of aspen wood. Fungal fatty aldehydes supported the in vitro oxidation by MnPs of a nonphenolic lignin model dimer, and also of the monomeric model veratryl alcohol. Experiments with the latter compound showed that the reactions were partially inhibited by oxalate, the chelator that white rot fungi employ to detach Mn3+ from the MnP active site, but nevertheless proceeded at its physiological concentration of 1 mM. The addition of catalase was inhibitory, which suggests that the standard MnP catalytic cycle is involved in the oxidation of aldehydes. MnP oxidized trans-2-nonenal quantitatively to trans-2-nonenoic acid with the consumption of one O2 equivalent. The data suggest that when Mn3+ remains associated with MnP, it can oxidize aldehydes to their acyl radicals, and the latter subsequently add O2 to become ligninolytic acylperoxyl radicals.IMPORTANCEThe biodegradation of lignin by white rot fungi is essential for the natural recycling of plant biomass and has useful applications in lignocellulose bioprocessing. Although fungal peroxidases have a key role in ligninolysis, past work indicates that biodegradation is initiated by smaller, as yet unidentified oxidants that can infiltrate the substrate. Here, we present evidence that the peroxidase-catalyzed oxidation of naturally occurring fungal aldehydes may provide a source of ligninolytic free radical oxidants.

Three-dimensional blueprinting of molecular patterns in liquid crystalline polymers.

Exploiting the interplay of anisotropic diamagnetic susceptibility of liquid crystalline monomers and site selective photopolymerization enables the fabrication of 3D freeforms with highly refined microstructures. Utilizing chain transfer agents in the mesogenic inks presents a pathway for broadly tuning the mechanical properties of liquid crystalline polymers and their response to stimuli. In particular, the combination of 1,4-benzenedimethanethiol and tetrabromomethane is shown to enable voxelated blueprinting of molecular order, while allowing for a modulation of the crosslink density and the mechanical properties. The formulation of these monomers allows for the resolution of the voxels to approach the limits set by the coherence lengths defined by the anchoring from surfaces. These compositions demonstrate the expected thermotropic responses while allowing for their functionalization with photochromic switches to elicit photomechanical responses. Actuation strains are shown to outstrip that accomplished with prior systems that did not access chain transfer agents to modulate the structure of the macromolecular network. Test cases of this system are shown to create freeform actuators that exploit the refined director patterns during high-resolution printing. These include topological defects, hierarchically-structured light responsive grippers, and biomimetic flyers whose flight dynamics can be actively modulated via irradiation with light.

Development of an International Virtual Multidisciplinary Tumor Board for Breast Cancer in Mongolia.

INTRODUCTION: Breast cancer is the most diagnosed cancer among Mongolian women and mortality rates are high. We describe a virtual multi-institutional and multidisciplinary tumor board (MTB) for breast cancer created to assist the National Cancer Center of Mongolia. MATERIALS AND METHODS: A virtual MTB for breast cancer was conducted with participation of two United States and 1 Mongolian cancer centers. A standardized template for presentations was developed. Recommendations were summarized and shared with participants. Collected data included patient demographics, tumor characteristics, stage, imaging and treatments performed, and recommendations. Questions were categorized as treatment, diagnosis, or palliative questions. RESULTS: Fifteen patients were evaluated. Median age was 39 y. 86.7% of breast cancers were invasive ductal cancers and 13.3% were metaplastic carcinomas. 53.3% were estrogen and progesterone receptor positive (ER+/PR+), 60% were HER2+, 13.3% were triple negative, and 26.7% were recurrent. 40% of patients were evaluated with mammography. 6% received positron emission tomography scans for metastatic evaluation. 66.7% of surgical patients received neoadjuvant chemotherapy. Herceptin was administered to 55.6% of patients with Her2+ cancers. Modified radical mastectomy was most commonly performed and reconstruction was rare. Sentinel lymph node biopsy was not performed. 66.7% of ER+/PR+ patients received endocrine therapy. 6.7% of patients received radiation. 75% of MTB questions pertained to treatment. Recommendations were related to systemic therapy (40%), surgical management (33.3%), pathology (13.3%), and imaging (13.3%). CONCLUSIONS: This study illustrates the development of an international, virtual, multi-institutional breast cancer MTB and provides insight into challenges and potential interventions to improve breast cancer care in Mongolia.

The Impact of Sibling Relationships on Behavioral and Sexual Health among Latino Sexual Minority Men.

Pre-exposure prophylaxis (PrEP) is a highly effective method for preventing HIV acquisition and plays a crucial role in the Ending the HIV Epidemic in the US initiative. However, there are various barriers that hinder the access and uptake of PrEP among Latino sexual minority men (SMM) at individual, interpersonal, and cultural levels. While the significance of cultural factors in designing and implementing HIV prevention programs for Latino populations has been consistently emphasized in the literature and prioritized by the Centers for Disease Control and Prevention, few studies have directly integrated these cultural factors into their programs. Our study aimed to investigate the potential influence of siblings in promoting the utilization of PrEP for HIV prevention, an area that has received limited attention. We conducted interviews with 31 pairs of siblings between December 2020 and January 2021, which were held in either English or Spanish and lasted approximately 45-60 min. The data were analyzed using a deductive thematic content analysis approach. The interviews revealed several key themes and categories, including: (1) Sibling support for coming out; (2) Types of support that siblings provide to each other for behavior change; (3) Sibling support for PrEP; and (4) The impact of the study interview on the quality of the sibling relationships. Our findings indicated that siblings were willing to provide support for PrEP in various ways, ranging from emotional support for brothers who may be concerned about potential rejection to practical support such as transportation or financial assistance. These results have significant implications for the design of HIV prevention interventions for Latinos. Incorporating siblings or other extended family members into these interventions can facilitate communication between siblings and their brothers, ultimately encouraging the use of PrEP or similar prevention methods. By considering the unique dynamics and support systems within Latino communities, researchers can develop more effective strategies to promote HIV prevention and support the well-being of Latino SMM.

Weakened sympathetic response and lower parasympathetic activity in intimate partner violence perpetrators when empathizing: Influence of autonomous activation in affective approach and prosocial behavior.

The autonomic nervous system (ANS) functioning has been proposed as a relevant method to characterize the therapeutic needs of intimate partner violence (IPV) perpetrators. Nevertheless, research has neglected the influence of the ANS on socio-affective functions in this population. The aim of the present study was to analyze the psychophysiological activity of IPV perpetrators (n = 52) compared to controls (n = 46) following an empathic induction task, performed through negative emotion-eliciting videos. We employed two general ANS markers (heart rate [HR] and respiratory rate [RR]), two sympathetic-related indexes (pre-ejection period [PEP] and skin conductance level [SCL]) and a parasympathetic biomarker (respiratory sinus arrhythmia [RSA]). Additionally, we explored the impact of psychophysiological activity on prosocial behavior using Hare's donation procedure. Compared to controls, IPV perpetrators reported lower HR and SCL following the task, as well as longer PEP, suggesting an attenuated sympathetic response to others' distress. No differences in the RSA response pattern were found, however, IPV perpetrators displayed lower overall RSA levels throughout the protocol, indicative of reduced parasympathetic activity. Besides, while no differences in prosocial performance were observed, greater sympathetic responses and overall parasympathetic activity predicted increased donations across the sample. Thus, a high sympathetic and parasympathetic activity might influence the occurrence of prosocial behavior. The present study provides further evidence supporting that IPV perpetrators cope differently with others' negative emotions. In line with this biopsychosocial perspective, insights are gained on the emotional processing of IPV perpetrators which, in turn, could contribute to improve IPV psychotherapeutic programs.

Exploring Psychosocial Distress in Caregivers of Children and Youth With Special Health Care Needs.

PURPOSE: Caring for a child or youth with special health care needs (CYSHCN) can be overwhelming. Parents and caregivers may experience psychosocial distress, such as depression, frustration, and hopelessness. The purpose of the current study was to gain further insight into families' perspectives on the psychosocial impacts of caring for CYSHCN to identify gaps in health care systems and strengthen systems of support. METHOD: A qualitative descriptive design was used in 16 parents and caregivers. Colaizzi's method of analysis and semi-structured interviews were used. RESULTS: Six themes emerged from this study: (1) Stigma and Isolation, (2) Religion as a Coping Mechanism, (3) Financial Challenges, (4) Bearing the Burden, (5) Familial Denial, and (6) System-Related Concerns. CONCLUSION: Psychiatric-mental health nurses (PMHNs) are in a pivotal position to use their knowledge, skills, and experiences to guide families. PMHNs can also engage communities and enhance mental health promotion to break the stigma associated with having a CYSHCN. [Journal of Psychosocial Nursing and Mental Health Services, xx(xx), xx-xx.].

Expanding the Physiological Role of Aryl-Alcohol Flavooxidases as Quinone Reductases.

Aryl-alcohol oxidases (AAOs) are members of the glucose-methanol-choline oxidase/dehydrogenase (GMC) superfamily. These extracellular flavoproteins have been described as auxiliary enzymes in the degradation of lignin by several white-rot basidiomycetes. In this context, they oxidize fungal secondary metabolites and lignin-derived compounds using O2 as an electron acceptor, and supply H2O2 to ligninolytic peroxidases. Their substrate specificity, including mechanistic aspects of the oxidation reaction, has been characterized in Pleurotus eryngii AAO, taken as a model enzyme of this GMC superfamily. AAOs show broad reducing-substrate specificity in agreement with their role in lignin degradation, being able to oxidize both nonphenolic and phenolic aryl alcohols (and hydrated aldehydes). In the present work, the AAOs from Pleurotus ostreatus and Bjerkandera adusta were heterologously expressed in Escherichia coli, and their physicochemical properties and oxidizing abilities were compared with those of the well-known recombinant AAO from P. eryngii. In addition, electron acceptors different from O2, such as p-benzoquinone and the artificial redox dye 2,6-Dichlorophenolindophenol, were also studied. Differences in reducing-substrate specificity were found between the AAO enzymes from B. adusta and the two Pleurotus species. Moreover, the three AAOs oxidized aryl alcohols concomitantly with the reduction of p-benzoquinone, with similar or even higher efficiencies than when using their preferred oxidizing-substrate, O2. IMPORTANCE In this work, quinone reductase activity is analyzed in three AAO flavooxidases, whose preferred oxidizing-substrate is O2. The results presented, including reactions in the presence of both oxidizing substrates-benzoquinone and molecular oxygen-suggest that such aryl-alcohol dehydrogenase activity, although less important than its oxidase activity in terms of maximal turnover, may have a physiological role during fungal decay of lignocellulose by the reduction of quinones (and phenoxy radicals) from lignin degradation, preventing repolymerization. Moreover, the resulting hydroquinones would participate in redox-cycling reactions for the production of hydroxyl free radical involved in the oxidative attack of the plant cell-wall. Hydroquinones can also act as mediators for laccases and peroxidases in lignin degradation in the form of semiquinone radicals, as well as activators of lytic polysaccharide monooxygenases in the attack of crystalline cellulose. Moreover, reduction of these, and other phenoxy radicals produced by laccases and peroxidases, promotes lignin degradation by limiting repolymerization reactions. These findings expand the role of AAO in lignin biodegradation.

A Meta-analysis of Cognitive Functioning in Intimate Partner Violence Perpetrators.

Numerous psychologists have shown interest in applying neuropsychological tests to study intimate partner violence (IPV) perpetrators and gain a further understanding of the underlying nature of this type of violence. However, up until now, no meta-analysis has drawn on all the available scientific literature to calculate whether consistent differences exist between the neuropsychological performance of IPV perpetrators and other samples of men (non-violent men, IPV perpetrators with drug misuse, and other men with criminal history). The aim of this study was to carry out this calculation and also measure whether neuropsychological performance explained IPV perpetration. We conducted a meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. After initially identifying 7243 sources, we eventually included a total of 25 publications. The number of studies included for effect size calculation in each cognitive domain ranged from two to nine. Taking solely into account studies comparing IPV perpetrators with non-violent men, our findings indicate that both IPV perpetrators who misuse drugs and those who do not exhibit worse neuropsychological functioning compared to non-violent men. These differences range from moderate to large for working memory, switching attention, cognitive flexibility, planning abilities, and phonemic fluency. However, while low functioning in response IQ was only observed in IPV perpetrators without drug misuse, continuous attention performance only differed in IPV perpetrators with drug misuse. It should be noted that most conclusions were consistent. In addition, the comparison between IPV perpetrator subsamples and other types of criminal convictions only revealed differences in switching attention, with IPV perpetrators presenting worse abilities than the rest of the subsamples. Finally, we also found some support for significant associations between neuropsychological performance and both physical and psychological IPV perpetration. This meta-analysis is a significant contribution that will help inform future clinical strategies for the early detection of cognitive needs. It will also guide the implementation of new or complementary intervention programs.

Dropout and recidivism are partly explained by emotional decoding and perspective taking deficits of intimate partner violence perpetrators.

Professionals and researchers have dedicated important efforts to understanding the underlying factors that explain the failure to complete interventions (dropout) and the recidivism of men convicted of intimate partner violence (IPV) against their female partners. There is a growing interest in measuring emotional decoding and empathic deficits in IPV perpetrators to better understand dropout and recidivism proneness, due to their direct impact on behavioral regulation. In the current study, we first aimed to examine whether the emotional decoding abilities of facial expressions and empathic abilities (cognitive and emotional), as well as their interrelationships in IPV perpetrators (n = 561), would explain dropout, treatment attendance, and recidivism (risk and official) once treatment ended. Our results allowed us to conclude that emotional decoding abilities and perspective taking (cognitive empathy) were significantly and negatively associated with dropout and recidivism. Two moderation models were significant. On the one hand, participants with low emotional decoding abilities presented lower intervention doses the lower their perspective taking. Furthermore, the percentage of participants that reoffended was higher among individuals with low and moderate perspective taking who dropped out. Therefore, our study highlights the importance of conducting emotional decoding and empathic assessments during the initial stages of intervention programs to clearly outline the therapeutic needs of IPV perpetrators. This would allow designing coadjuvant and complementary training programs that can support the main interventions by increasing treatment adherence and, in turn, reducing the risk of recidivism.

Biopsychosocial Factors of Depression Among Hispanic Women Aged ≥50 Years.

The purpose of the current study was to identify biopsychosocial factors associated with depressive symptoms among Hispanic women aged ≥50 years. Cross-sectional data related to 10 biological, psychological, and social factors were analyzed. Center for Epidemiologic Studies Depression Scale scores suggested that 32% of the sample had depressive symptoms. Self-esteem, self-perception of health status, income, and chronic pain had statistically significant associations with depressive symptoms. A logistic regression analysis showed that increasing self-esteem scores were associated with decreases in the likelihood of having depressive symptoms. Findings underscore that depression is associated with biological, psychological, and social factors. Culturally tailored interventions that aim at targeting these factors may have an impact on Hispanic women's depression and overall well-being. [Journal of Psychosocial Nursing and Mental Health Services, 61(11), 32-42.].

C-H Fluoromethoxylation of Arenes by Photoredox Catalysis.

Redox-active N-(fluoromethoxy)benzotriazoles were made accessible from fluoroacetic acid and hydroxybenzotriazoles via electrodecarboxylative coupling. After alkylation, they become effective monofluoromethoxylation reagents, enabling the photocatalytic C-H functionalization of arenes. Thus, irradiation of 1-(OCH2 F)-3-Me-6-(CF3 )benzotriazolium triflate with blue LED light in the presence of [Ru(bpy)3 (PF6 )2 ] promotes the synthesis of diversely functionalized aryl monofluoromethyl ethers. This method allows the late-stage functionalization of biologically relevant structures without relying on ecologically problematic halofluorocarbons.

Genomic Analysis Enlightens Agaricales Lifestyle Evolution and Increasing Peroxidase Diversity.

As actors of global carbon cycle, Agaricomycetes (Basidiomycota) have developed complex enzymatic machineries that allow them to decompose all plant polymers, including lignin. Among them, saprotrophic Agaricales are characterized by an unparalleled diversity of habitats and lifestyles. Comparative analysis of 52 Agaricomycetes genomes (14 of them sequenced de novo) reveals that Agaricales possess a large diversity of hydrolytic and oxidative enzymes for lignocellulose decay. Based on the gene families with the predicted highest evolutionary rates-namely cellulose-binding CBM1, glycoside hydrolase GH43, lytic polysaccharide monooxygenase AA9, class-II peroxidases, glucose-methanol-choline oxidase/dehydrogenases, laccases, and unspecific peroxygenases-we reconstructed the lifestyles of the ancestors that led to the extant lignocellulose-decomposing Agaricomycetes. The changes in the enzymatic toolkit of ancestral Agaricales are correlated with the evolution of their ability to grow not only on wood but also on leaf litter and decayed wood, with grass-litter decomposers as the most recent eco-physiological group. In this context, the above families were analyzed in detail in connection with lifestyle diversity. Peroxidases appear as a central component of the enzymatic toolkit of saprotrophic Agaricomycetes, consistent with their essential role in lignin degradation and high evolutionary rates. This includes not only expansions/losses in peroxidase genes common to other basidiomycetes but also the widespread presence in Agaricales (and Russulales) of new peroxidases types not found in wood-rotting Polyporales, and other Agaricomycetes orders. Therefore, we analyzed the peroxidase evolution in Agaricomycetes by ancestral-sequence reconstruction revealing several major evolutionary pathways and mapped the appearance of the different enzyme types in a time-calibrated species tree.

Photochemical Sandmeyer-type Halogenation of Arenediazonium Salts.

Trihalide salts were found to efficiently promote photochemical dediazotizing halogenations of diazonium salts. In contrast to classical Sandmeyer reactions, no metal catalysts are required to achieve high yields and outstanding selectivities for halogenation over competing hydridodediazotization. Convenient protocols are disclosed for synthetically meaningful brominations, iodinations, and chlorinations of diversely functionalized derivatives.

Peroxidase evolution in white-rot fungi follows wood lignin evolution in plants.

A comparison of sequenced Agaricomycotina genomes suggests that efficient degradation of wood lignin was associated with the appearance of secreted peroxidases with a solvent-exposed catalytic tryptophan. This hypothesis is experimentally demonstrated here by resurrecting ancestral fungal peroxidases, after sequence reconstruction from genomes of extant white-rot Polyporales, and evaluating their oxidative attack on the lignin polymer by state-of-the-art analytical techniques. Rapid stopped-flow estimation of the transient-state constants for the 2 successive one-electron transfers from lignin to the peroxide-activated enzyme (k2app and k3app ) showed a progressive increase during peroxidase evolution (up to 50-fold higher values for the rate-limiting k3app ). The above agreed with 2-dimensional NMR analyses during steady-state treatments of hardwood lignin, showing that its degradation (estimated from the normalized aromatic signals of lignin units compared with a control) and syringyl-to-guaiacyl ratio increased with the enzyme evolutionary distance from the first peroxidase ancestor. More interestingly, the stopped-flow estimations of electron transfer rates also showed how the most recent peroxidase ancestors that already incorporated the exposed tryptophan into their molecular structure (as well as the extant lignin peroxidase) were comparatively more efficient at oxidizing hardwood (angiosperm) lignin, while the most ancestral "tryptophanless" enzymes were more efficient at abstracting electrons from softwood (conifer) lignin. A time calibration of the ancestry of Polyporales peroxidases localized the appearance of the first peroxidase with a solvent-exposed catalytic tryptophan to 194 ± 70 Mya, coincident with the diversification of angiosperm plants characterized by the appearance of dimethoxylated syringyl lignin units.

Exploring the Psychosocial Impact of Living With HIV on Minority Older Women.

BACKGROUND: Among older adults, minority older women will account for 60% of the new HIV diagnoses. The psychosocial impact of living with HIV among this vulnerable population narrated by their own voices has been understudied. AIMS: The purpose of this study was to explore the psychosocial impact of living with HIV on minority older women. METHODS: In-depth interviews were conducted with 28 minority older women living with HIV at an Ambulatory Care Center HIV Clinic in South Florida. All interviews were audio-recorded and transcribed verbatim. Conventional content analysis was used to identify and define the major themes that emerged from the interviews. Questions included those concerning description of life after the HIV diagnosis, most challenging aspects of life after the diagnosis, and daily activities since the diagnosis. RESULTS: The analysis of the interview data led to five main themes: (I) Social Impact of HIV, (II) Threats to Health and Well-Being, (III) HIV as a Death Sentence, (IV) Spirituality, and (V) HIV Treatment Adherence. In their narratives, women described a myriad of psychosocial issues such as depressed mood, isolation, economic challenges, stigma, anhedonia of interest, fear of death, among others. CONCLUSIONS: There is a compelling empirical need for rapid implementation of a culturally tailored, holistic, low-cost, multistrategy intervention to early screen and reduce the psychosocial impact of HIV among minority older women.

Gene family expansions and transcriptome signatures uncover fungal adaptations to wood decay.

Because they comprise some of the most efficient wood-decayers, Polyporales fungi impact carbon cycling in forest environment. Despite continuous discoveries on the enzymatic machinery involved in wood decomposition, the vision on their evolutionary adaptation to wood decay and genome diversity remains incomplete. We combined the genome sequence information from 50 Polyporales species, including 26 newly sequenced genomes and sought for genomic and functional adaptations to wood decay through the analysis of genome composition and transcriptome responses to different carbon sources. The genomes of Polyporales from different phylogenetic clades showed poor conservation in macrosynteny, indicative of genome rearrangements. We observed different gene family expansion/contraction histories for plant cell wall degrading enzymes in core polyporoids and phlebioids and captured expansions for genes involved in signalling and regulation in the lineages of white rotters. Furthermore, we identified conserved cupredoxins, thaumatin-like proteins and lytic polysaccharide monooxygenases with a yet uncharacterized appended module as new candidate players in wood decomposition. Given the current need for enzymatic toolkits dedicated to the transformation of renewable carbon sources, the observed genomic diversity among Polyporales strengthens the relevance of mining Polyporales biodiversity to understand the molecular mechanisms of wood decay.

Thermomechanically active electrodes power work-dense soft actuators.

The effect of chain extender structure and composition on the thermomechanical properties of liquid crystal elastomers (LCE) synthesized using thiol-acrylate Michael addition is presented. The intrinsic molecular stiffness of the thiol chain extender and its relative molar ratio to acrylate-based host mesogens determine the magnitudes of the thermomechanical strains, temperatures at which they are realized and the mechanical work-content. A non-linear structure-property relationship emerges, wherein higher concentrations of flexible extenders first magnify the thermomechanical sensitivity, but a continued increase leads to weaker actuation. Understanding this interplay leads to a composite material platform, enabling a peak specific work production of ∼2 J kg-1 using ∼115 mW of electrical power supplied at 2 V. Composites of LCE with eGaIn liquid metal (LM) are prepared, which act as heaters, while being capable of actuation themselves. The thermomechanically active electrodes convert the electrical power into Joule heat, which they efficiently couple with the neat LCE to which they are bound. This system harnesses the nascent responsiveness of the LCE using electrodes that work with them, instead of fighting against them (or passively standing in the way). Specific work generated increases when subjected to increasing levels of load, reaching a peak at loads ∼260× the actuator weight. These ideas are extended to tri-layered actuators, where LCE films with orthogonal molecular orientations sandwich LCE-LM composite heaters. Torsional actuation modes are harnessed to twist under load.

Optimizing operational parameters for the enzymatic production of furandicarboxylic acid building block.

BACKGROUND: 2,5-Furandicarboxylic acid (FDCA) is a precursor for green plastics due to its structural similarity to terephthalic acid, a common precursor of oil-derived polymers, and its potential production from sugars obtained from plant biomass. Hydroxymethylfurfural oxidase (HMFO) has been reported as a promising biocatalyst for FDCA production since it can convert bio-based 5-hydroxymethylfurfural (HMF) into FDCA building block. This three-step oxidation reaction occurs through the diformylfuran and 2,5-formylfurancarboxylic acid (FFCA) intermediates. Several efforts have been made for the development of HMFO variants that increase FDCA yields by improving their activities over the reaction intermediates. However, there is still limited insight into how operational conditions can influence these enzymatic reactions. The setup of optimal reaction conditions would enable to understand potential problems hampering the effective industrial production of this bioplastic precursor using HMFO as biocatalyst. RESULTS: In this work, several parameters affecting the performance of Methylovorus sp HMFO oxidizing HMF have been analyzed for the wild-type enzyme, and its V367R and W466F single variants, V367R/W466F double variant, and I73V/H74Y/G356H/V367R/T414K/A419Y/A435E/W466F (8BxHMFO) octuple variant. Our results show how the oxidation of HMF by HMFO enzymes is highly influenced by pH, with different optimal pH values for the different improved variants. Moreover, the enzymes are not stable at high hydrogen peroxide concentrations and their activity is inhibited by the FFCA intermediate in a pH-dependent way. These limitations can be efficiently overcome with the addition of catalase to the reaction medium, which removes the hydrogen peroxide formed during the oxidations, and the controlled dosage of the substrate to limit the amount of FFCA accumulated in the reaction. The different behavior of wild-type HMFO and its variants against pH, hydrogen peroxide and FFCA highlights the importance of considering each variant as an individual enzyme with its own operational conditions for an eventual industrial FDCA production. CONCLUSIONS: This work provides information of those parameters that condition a high production of FDCA by HMFO. Unraveling these factors allowed to increase the FDCA yields by using the most stable enzymes at their optimal pH for HMF oxidation, removing the peroxide with catalase, and avoiding FFCA accumulation by controlling substrate and/or enzyme concentration. These above findings will be useful when planning a future scale-up of these conversions and will provide new viewpoints for the design of HMFO variants that render a more effective performance during HMF conversion into FDCA.

Evolutionary convergence in lignin-degrading enzymes.

The resurrection of ancestral enzymes of now-extinct organisms (paleogenetics) is a developing field that allows the study of evolutionary hypotheses otherwise impossible to be tested. In the present study, we target fungal peroxidases that play a key role in lignin degradation, an essential process in the carbon cycle and often a limiting step in biobased industries. Ligninolytic peroxidases are secreted by wood-rotting fungi, the origin of which was recently established in the Carboniferous period associated with the appearance of these enzymes. These first peroxidases were not able to degrade lignin directly and used diffusible metal cations to attack its phenolic moiety. The phylogenetic analysis of the peroxidases of Polyporales, the order in which most extant wood-rotting fungi are included, suggests that later in evolution these enzymes would have acquired the ability to degrade nonphenolic lignin using a tryptophanyl radical interacting with the bulky polymer at the surface of the enzyme. Here, we track this powerful strategy for lignin degradation as a phenotypic trait in fungi and show that it is not an isolated event in the evolution of Polyporales. Using ancestral enzyme resurrection, we study the molecular changes that led to the appearance of the same surface oxidation site in two distant peroxidase lineages. By characterization of the resurrected enzymes, we demonstrate convergent evolution at the amino acid level during the evolution of these fungi and track the different changes leading to phylogenetically distant ligninolytic peroxidases from ancestors lacking the ability to degrade nonphenolic lignin.