Isochrony in barks of Cape fur seal (Arctocephalus pusillus pusillus) pups and adults

Animal vocal communication often relies on call sequences. The temporal patterns of such sequences can be adjusted to other callers, follow complex rhythmic structures or exhibit a metronome-like pattern (i.e., isochronous). How regular are the temporal patterns in animal signals, and what influences their precision? If present, are rhythms already there early in ontogeny? Here, we describe an exploratory study of Cape fur seal (Arctocephalus pusillus pusillus) barks-a vocalisation type produced across many pinniped species in rhythmic, percussive bouts. This study is the first quantitative description of barking in Cape fur seal pups. We analysed the rhythmic structures of spontaneous barking bouts of pups and adult females from the breeding colony in Cape Cross, Namibia. Barks of adult females exhibited isochrony, that is they were produced at fairly regular points in time. Instead, intervals between pup barks were more variable, that is skipping a bark in the isochronous series occasionally. In both age classes, beat precision, that is how well the barks followed a perfect template, was worse when barking at higher rates. Differences could be explained by physiological factors, such as respiration or arousal. Whether, and how, isochrony develops in this species remains an open question. This study provides evidence towards a rhythmic production of barks in Cape fur seal pups and lays the groundwork for future studies to investigate the development of rhythm using multidimensional metrics.

Observation of the Anomalous Hall Effect in a Layered Polar Semiconductor

Progress in magnetoelectric materials is hindered by apparently contradictory requirements for time-reversal symmetry broken and polar ferroelectric electronic structure in common ferromagnets and antiferromagnets. Alternative routes can be provided by recent discoveries of a time-reversal symmetry breaking anomalous Hall effect (AHE) in noncollinear magnets and altermagnets, but hitherto reported bulk materials are not polar. Here, the authors report the observation of a spontaneous AHE in doped AgCrSe2 , a layered polar semiconductor with an antiferromagnetic coupling between Cr spins in adjacent layers. The anomalous Hall resistivity 3μ Ω c m $\mu \Omega \, \textnormal {cm}$ is comparable to the largest observed in compensated magnetic systems to date, and is rapidly switched off when the angle of an applied magnetic field is rotated to ≈80° from the crystalline c-axis. The ionic gating experiments show that the anomalous Hall conductivity magnitude can be enhanced by modulating the p-type carrier density. They also present theoretical results that suggest the AHE is driven by Berry curvature due to noncollinear antiferromagnetic correlations among Cr spins, which are consistent with the previously suggested magnetic ordering in AgCrSe2 . The results open the possibility to study the interplay of magnetic and ferroelectric-like responses in this fascinating class of materials.

Genotyping blastoderms of avian eggs

Undeveloped eggs occur frequently in birds and are often considered infertile, and discarded. However, the majority of undeveloped eggs may in fact have been fertilised and embryos might have died at an early stage. Such eggs contain valuable information, for example about offspring sex and paternity, and level of inbreeding. Obtaining such information may also give insight into the patterns and causes of early embryo mortality. Here we describe a simple technique for removing embryo cells from the blastoderm to obtain DNA to genotype the offspring and unequivocally ascertain fertilisation status, while retaining the overlying perivitelline layer (PVL) for sperm counts over the entire membrane. We tested this method on freshly collected eggs (high-quality material), as well as on eggs from abandoned clutches and unhatched eggs (potentially deteriorated material) of blue tits (Cyanistes caeruleus). We sampled a total of 707 eggs from a wild population of blue tits, extracted DNA from the eggs' blastoderm using a Qiagen kit, and genotyped the samples with 14 polymorphic microsatellite markers, plus one sexing marker. Overall, we successfully genotyped 97% of all eggs. Our study is the most extensive dataset of genotyped undeveloped eggs to date and demonstrates that one can reliably genotype undeveloped fertile eggs as well as retain the PVL for observations of sperm and embryo cells.

Quantitative multiorgan proteomics of fatal COVID-19 uncovers tissue-specific effects beyond inflammation

SARS-CoV-2 may directly and indirectly damage lung tissue and other host organs, but there are few system-wide, untargeted studies of these effects on the human body. Here, we developed a parallelized mass spectrometry (MS) proteomics workflow enabling the rapid, quantitative analysis of hundreds of virus-infected FFPE tissues. The first layer of response to SARS-CoV-2 in all tissues was dominated by circulating inflammatory molecules. Beyond systemic inflammation, we differentiated between systemic and true tissue-specific effects to reflect distinct COVID-19-associated damage patterns. Proteomic changes in the lungs resembled those of diffuse alveolar damage (DAD) in non-COVID-19 patients. Extensive organ-specific changes were also evident in the kidneys, liver, and lymphatic and vascular systems. Secondary inflammatory effects in the brain were related to rearrangements in neurotransmitter receptors and myelin degradation. These MS-proteomics-derived results contribute substantially to our understanding of COVID-19 pathomechanisms and suggest strategies for organ-specific therapeutic interventions.

Language and reading impairments are associated with increased prevalence of non-right-handedness

Handedness has been studied for association with language-related disorders because of its link with language hemispheric dominance. No clear pattern has emerged, possibly because of small samples, publication bias, and heterogeneous criteria across studies. Non-right-handedness (NRH) frequency was assessed in N = 2503 cases with reading and/or language impairment and N = 4316 sex-matched controls identified from 10 distinct cohorts (age range 6-19 years old; European ethnicity) using a priori set criteria. A meta-analysis (Ncases  = 1994) showed elevated NRH % in individuals with language/reading impairment compared with controls (OR = 1.21, CI = 1.06-1.39, p = .01). The association between reading/language impairments and NRH could result from shared pathways underlying brain lateralization, handedness, and cognitive functions.

Transgene insertion into the plastid genome alters expression of adjacent native chloroplast genes at the transcriptional and translational levels

In plant biotechnology and basic research, chloroplasts have been used as chassis for the expression of various transgenes. However, potential unintended side effects of transgene insertion and high-level transgene expression on the expression of native chloroplast genes are often ignored and have not been studied comprehensively. Here, we examined expression of the chloroplast genome at both the transcriptional and translational levels in five transplastomic tobacco (Nicotiana tabacum) lines carrying the identical aadA resistance marker cassette in diverse genomic positions. Although none of the lines exhibits a pronounced visible phenotype, the analysis of three lines that contain the aadA insertion in different locations within the petL-petG-psaJ-rpl33-rps18 transcription unit demonstrates that transcriptional read-through from the aadA resistance marker is unavoidable, and regularly causes overexpression of downstream sense-oriented chloroplast genes at the transcriptional and translational levels. Investigation of additional lines that harbour the aadA intergenically and outside of chloroplast transcription units revealed that expression of the resistance marker can also cause antisense effects by interference with transcription/transcript accumulation and/or translation of downstream antisense-oriented genes. In addition, we provide evidence for a previously suggested role of genomically encoded tRNAs in chloroplast transcription termination and/or transcript processing. Together, our data uncover principles of neighbouring effects of chloroplast transgenes and suggest general strategies for the choice of transgene insertion sites and expression elements to minimize unintended consequences of transgene expression on the transcription and translation of native chloroplast genes.

A progeroid syndrome caused by a deep intronic variant in TAPT1 is revealed by RNA/SI-NET sequencing

Exome sequencing has introduced a paradigm shift for the identification of germline variations responsible for Mendelian diseases. However, non-coding regions, which make up 98% of the genome, cannot be captured. The lack of functional annotation for intronic and intergenic variants makes RNA-seq a powerful companion diagnostic. Here, we illustrate this point by identifying six patients with a recessive Osteogenesis Imperfecta (OI) and neonatal progeria syndrome. By integrating homozygosity mapping and RNA-seq, we delineated a deep intronic TAPT1 mutation (c.1237-52 G>A) that segregated with the disease. Using SI-NET-seq, we document that TAPT1's nascent transcription was not affected in patients' fibroblasts, indicating instead that this variant leads to an alteration of pre-mRNA processing. Predicted to serve as an alternative splicing branchpoint, this mutation enhances TAPT1 exon 12 skipping, creating a protein-null allele. Additionally, our study reveals dysregulation of pathways involved in collagen and extracellular matrix biology in disease-relevant cells. Overall, our work highlights the power of transcriptomic approaches in deciphering the repercussions of non-coding variants, as well as in illuminating the molecular mechanisms of human diseases.

Selective incorporation of 5-hydroxytryptophan blocks long range electron transfer in oxalate decarboxylase

Oxalate decarboxylase from Bacillus subtilis is a binuclear Mn-dependent acid stress response enzyme that converts the mono-anion of oxalic acid into formate and carbon dioxide in a redox neutral unimolecular disproportionation reaction. A π-stacked tryptophan dimer, W96 and W274, at the interface between two monomer subunits facilitates long-range electron transfer between the two Mn ions and plays an important role in the catalytic mechanism. Substitution of W96 with the unnatural amino acid 5-hydroxytryptophan leads to a persistent EPR signal which can be traced back to the neutral radical of 5-hydroxytryptophan with its hydroxyl proton removed. 5-Hydroxytryptophan acts as a hole sink preventing the formation of Mn(III) at the N-terminal active site and strongly suppresses enzymatic activity. The lower boundary of the standard reduction potential for the active site Mn(II)/Mn(III) couple can therefore be estimated as 740 mV against the normal hydrogen electrode at pH 4, the pH of maximum catalytic efficiency. Our results support the catalytic importance of long-range electron transfer in oxalate decarboxylase while at the same time highlighting the utility of unnatural amino acid incorporation and specifically the use of 5-hydroxytryptophan as an energetic sink for hole hopping to probe electron transfer in redox proteins.

Dewetting-Assisted Interface Templating: Complex Emulsions to Multicavity Particles

Interfacial tension-driven formation of intricate microparticle geometries from complex emulsions is presented in this work. Emulsion-templating is a reliable platform for the generation of a diverse set of microparticles. Here, water-in-styrene-in-water complex emulsions undergo reproducible metamorphosis, i.e., from liquid state emulsions to solid structured microparticles are employed. In contrast to the traditional usage of glass-based microfluidics, polydimethylsiloxane (PDMS) swelling behavior is employed to generate complex emulsions with multiple inner cores. In the presence of block copolymer surfactant, these emulsions undergo gravity-driven dewetting of styrene, to transform into membranous structures with compartments. Further polymerization of styrene skeletal remains resulted in microparticles with interesting geometries and intact membranes. Mechanical and confocal microscopic studies prove the absence of polystyrene within these membranes. Using osmotic pressure, membrane rupture and release of encapsulated gold nanoparticles from such polymerized emulsions leading up to applications in cargo delivery and membrane transport are promoted. Even after membrane rupture, the structured microparticles have shown interesting light-scattering behavior for applications in structural coloring and biosensing. Thereby, proving PDMS-based swelling as a potential methodology for reproducible production of complex emulsions with a potential to be transformed into membranous emulsions or solid microparticles with intricate structures and multiple applications.

Small Size, Big Impact: Recent Progress in Bottom-Up Synthesized Nanographenes for Optoelectronic and Energy Applications

Bottom-up synthesized graphene nanostructures, including 0D graphene quantum dots and 1D graphene nanoribbons, have recently emerged as promising candidates for efficient, green optoelectronic, and energy storage applications. The versatility in their molecular structures offers a large and novel library of nanographenes with excellent and adjustable optical, electronic, and catalytic properties. In this minireview, recent progress on the fundamental understanding of the properties of different graphene nanostructures, and their state-of-the-art applications in optoelectronics and energy storage are summarized. The properties of pristine nanographenes, including high emissivity and intriguing blinking effect in graphene quantum dots, superior charge transport properties in graphene nanoribbons, and edge-specific electrochemistry in various graphene nanostructures, are highlighted. Furthermore, it is shown that emerging nanographene-2D material-based van der Waals heterostructures provide an exciting opportunity for efficient green optoelectronics with tunable characteristics. Finally, challenges and opportunities of the field are highlighted by offering guidelines for future combined efforts in the synthesis, assembly, spectroscopic, and electrical studies as well as (nano)fabrication to boost the progress toward advanced device applications.

Synthesis and Characterizations of 5,5'-Bibenzo[rst]pentaphene with Axial Chirality and Symmetry-Breaking Charge Transfer

Exploration of novel biaryls consisting of two polycyclic aromatic hydrocarbon (PAH) units can be an important strategy toward further developments of organic materials with unique properties. In this study, 5,5'-bibenzo[rst]pentaphene (BBPP) with two benzo[rst]pentaphene (BPP) units is synthesized in an efficient and versatile approach, and its structure is unambiguously elucidated by X-ray crystallography. BBPP exhibits axial chirality, and the (M)- and (P)-enantiomers are resolved by chiral high-performance liquid chromatography and studied by circular dichroism spectroscopy. These enantiomers have a relatively high isomerization barrier of 43.6 kcal mol^-1 calculated by density functional theory. The monomer BPP and dimer BBPP are characterized by UV-vis absorption and fluorescence spectroscopy, cyclic voltammetry, and femtosecond transient absorption spectroscopy. The results indicate that both BPP and BBPP fluoresce from a formally dark S₁ electronic state that is enabled by Herzberg-Teller intensity borrowing from a neighboring bright S₂ state. While BPP exhibits a relatively low photoluminescence quantum yield (PLQY), BBPP exhibits a significantly enhanced PLQY due to a greater S₂ intensity borrowing. Moreover, symmetry-breaking charge transfer in BBPP is demonstrated by spectroscopic investigations in solvents of different polarity. This suggests high potential for singlet fission in such π-extended biaryls through appropriate molecular design.

Impaired KIN10 function restores developmental defects in the Arabidopsis trehalose 6-phosphate synthase1 (tps1) mutant

Sensing carbohydrate availability is essential for plants to coordinate their growth and development. In Arabidopsis thaliana, TREHALOSE 6-PHOSPHATE SYNTHASE 1 (TPS1) and its product, trehalose 6-phosphate (T6P), are important for the metabolic control of development. tps1 mutants are embryo-lethal and unable to flower when embryogenesis is rescued. T6P regulates development in part through inhibition of SUCROSE NON-FERMENTING1 RELATED KINASE1 (SnRK1). Here, we explored the role of SnRK1 in T6P-mediated plant growth and development using a combination of a mutant suppressor screen and genetic, cellular and transcriptomic approaches. We report nonsynonymous amino acid substitutions in the catalytic KIN10 and regulatory SNF4 subunits of SnRK1 that can restore both embryogenesis and flowering of tps1 mutant plants. The identified SNF4 point mutations disrupt the interaction with the catalytic subunit KIN10. Contrary to the common view that the two A. thaliana SnRK1 catalytic subunits act redundantly, we found that loss-of-function mutations in KIN11 are unable to restore embryogenesis and flowering, highlighting the important role of KIN10 in T6P signalling.

Multimodal Enzyme-Carrying Suprastructures for Rapid and Sensitive Biocatalytic Cascade Reactions

Colloidal assemblies of mesoporous suprastructures provide effective catalysis in an advantageous volume-confined environment. However, typical fabrication methods of colloidal suprastructures are carried out under toxic or harmful conditions for unstable biomolecules, such as, biocatalytic enzymes. For this reason, biocatalytic enzymes have rarely been used with suprastructures, even though biocatalytic cascade reactions in confined environments are more efficient than in open conditions. Here, multimodal enzyme- and photocatalyst-carrying superstructures with efficient cascade reactions for colorimetric glucose detection are demonstrated. The suprastructures consisting of various functional nanoparticles, including enzyme-carrying nanoparticles, are fabricated by surface-templated evaporation driven suprastructure synthesis on polydimethylsiloxane-grafted surfaces at ambient conditions. For the fabrication of suprastructures, no additional chemicals and reactions are required, which allows maintaining the enzyme activities. The multimodal enzymes (glucose oxidase and peroxidase)-carrying suprastructures exhibit rapid and highly sensitive glucose detection via two enzyme cascade reactions in confined geometry. Moreover, the combination of enzymatic and photocatalytic cascade reactions of glucose oxidase to titanium dioxide nanoparticles is successfully realized for the same assay. These results show promising abilities of multiple colloidal mixtures carrying suprastructures for effective enzymatic reactions and open a new door for advanced biological reactions and enzyme-related works.

Heat-Mitigated Design and Lorentz Force-Based Steering of an MRI-Driven Microcatheter toward Minimally Invasive Surgery

Catheters integrated with microcoils for electromagnetic steering under the high, uniform magnetic field within magnetic resonance (MR) scanners (3-7 Tesla) have enabled an alternative approach for active catheter operations. Achieving larger ranges of tip motion for Lorentz force-based steering have previously been dependent on using high power coupled with active cooling, bulkier catheter designs, or introducing additional microcoil sets along the catheter. This work proposes an alternative approach using a heat-mitigated design and actuation strategy for a magnetic resonance imaging (MRI)-driven microcatheter. A quad-configuration microcoil (QCM) design is introduced, allowing miniaturization of existing MRI-driven, Lorentz force-based catheters down to 1-mm diameters with minimal power consumption (0.44 W). Heating concerns are experimentally validated using noninvasive MRI thermometry. The Cosserat model is implemented within an MR scanner and results demonstrate a desired tip range up to 110° with 4° error. The QCM is used to validate the proposed model and power-optimized steering algorithm using an MRI-compatible neurovascular phantom and ex vivo kidney tissue. The power-optimized tip orientation controller conserves as much as 25% power regardless of the catheter's initial orientation. These results demonstrate the implementation of an MRI-driven, electromagnetic catheter steering platform for minimally invasive surgical applications without the need for camera feedback or manual advancement via guidewires. The incorporation of such system in clinics using the proposed design and actuation strategy can further improve the safety and reliability of future MRI-driven active catheter operations.

Nonswelling and Hydrolytically Stable Hydrogels Uncover Cellular Mechanosensing in 3D

While matrix stiffness regulates cell behavior on 2D substrates, recent studies using synthetic hydrogels have suggested that in 3D environments, cell behavior is primarily impacted by matrix degradability, independent of stiffness. However, these studies did not consider the potential impact of other confounding matrix parameters that typically covary with changes in stiffness, particularly, hydrogel swelling and hydrolytic stability, which may explain the previously observed distinctions in cell response in 2D versus 3D settings. To investigate how cells sense matrix stiffness in 3D environments, a nonswelling, hydrolytically stable, linearly elastic synthetic hydrogel model is developed in which matrix stiffness and degradability can be tuned independently. It is found that matrix degradability regulates cell spreading kinetics, while matrix stiffness dictates the final spread area once cells achieve equilibrium spreading. Importantly, the differentiation of human mesenchymal stromal cells toward adipocytes or osteoblasts is regulated by the spread state of progenitor cells upon initiating differentiation. These studies uncover matrix stiffness as a major regulator of cell function not just in 2D, but also in 3D environments, and identify matrix degradability as a critical microenvironmental feature in 3D that in conjunction with matrix stiffness dictates cell spreading, cytoskeletal state, and stem cell differentiation outcomes.

Sustainable Sorbitol Dehydration to Isosorbide using Solid Acid Catalysts: Transition from Batch Reactor to Continuous-Flow System

Isosorbide is one of the most interesting cellulosic-derived molecules with great potential to be implemented in wide range of products that shaping our daily life. This Review describes the recent developments in the production of isosorbide from sorbitol in batch and continuous-flow systems under hydrothermal conditions using solid acid catalysts. Moreover, the current hurdles and challenges regarding the synthesis of isosorbide from cellulosic biomass in continuous-flow process using solid acid catalysts are summarized, as well as the scaling-up of this process into pilot level, which will lead to an established industrial process with high sustainability metrics.

Incorporation of Cu/Ni in Ordered Mesoporous Co-Based Spinels to Facilitate Oxygen Evolution and Reduction Reactions in Alkaline Media and Aprotic Li-O2 Batteries

Ordered mesoporous CuNiCo oxides were prepared via nanocasting with varied Cu/Ni ratio to establish its impact on the electrochemical performance of the catalysts. Physicochemical properties were determined along with the electrocatalytic activities toward oxygen evolution/reduction reactions (OER/ORR). Combining Cu, Ni, and Co allowed creating active and stable bifunctional electrocatalysts. CuNiCo oxide (Cu/Ni≈1 : 4) exhibited the highest current density of 411 mA cm^-2 at 1.7 V vs. reversible hydrogen electrode (RHE) and required the lowest overpotential of 312 mV to reach 10 mA cm^-2 in 1 m KOH after 200 cyclic voltammograms. OER measurements were also conducted in the purified 1 m KOH, where CuNiCo oxide (Cu/Ni≈1 : 4) also outperformed NiCo oxide and showed excellent chemical and catalytic stability. For ORR, Cu/Ni incorporation provided higher current density, better kinetics, and facilitated the 4e^- pathway of the oxygen reduction reaction. The tests in Li-O₂ cells highlighted that CuNiCo oxide can effectively promote ORR and OER at a lower overpotential.

Molecular Epidemiology and Transmission Dynamics of the HIV-1 Epidemic in Ethiopia: Epidemic Decline Coincided With Behavioral Interventions Before ART Scale-Up

Background

Ethiopia is one of the sub-Saharan countries hit hard by the HIV epidemic. Previous studies have shown that subtype C dominates the Ethiopian HIV-1 epidemic, but the evolutionary and temporal dynamics of HIV-1 in Ethiopia have not been closely scrutinized. Understanding the evolutionary and epidemiological pattern of HIV is vital to monitor the spread, evaluate and implement HIV prevention strategies.

Methods

We analyzed 1,276 Ethiopian HIV-1 subtype C polymerase (pol sequences), including 144 newly generated sequences, collected from different parts of the country from 1986 to 2017. We employed state-of-art maximum likelihood and Bayesian phylodynamic analyses to comprehensively describe the evolutionary dynamics of the HIV-1 epidemic in Ethiopia. We used Bayesian phylodynamic models to estimate the dynamics of the effective population size (Ne) and reproductive numbers (Re) through time for the HIV epidemic in Ethiopia.

Results

Our analysis revealed that the Ethiopian HIV-1 epidemic originated from two independent introductions at the beginning of the 1970s and 1980s from eastern and southern African countries, respectively, followed by epidemic growth reaching its maximum in the early 1990s. We identified three large clusters with a majority of Ethiopian sequences. Phylodynamic analyses revealed that all three clusters were characterized by high transmission rates during the early epidemic, followed by a decline in HIV-1 transmissions after 1990. Re was high (4–6) during the earlier time of the epidemic but dropped significantly and remained low (Re < 1) after the mid-1990. Similarly, with an expected shift in time, the effective population size (Ne) steadily increased until the beginning of 2000, followed by a decline and stabilization until recent years. The phylodynamic analyses corroborated the modeled UNAIDS incidence and prevalence estimates.

Conclusion

The rapid decline in the HIV epidemic took place a decade before introducing antiretroviral therapy in Ethiopia and coincided with early behavioral, preventive, and awareness interventions implemented in the country. Our findings highlight the importance of behavioral interventions and antiretroviral therapy scale-up to halt and maintain HIV transmissions at low levels (Re < 1). The phylodynamic analyses provide epidemiological insights not directly available using standard surveillance and may inform the adjustment of public health strategies in HIV prevention in Ethiopia.

An overview of the first 5 years of the ENIGMA obsessive-compulsive disorder working group: The power of worldwide collaboration

Neuroimaging has played an important part in advancing our understanding of the neurobiology of obsessive-compulsive disorder (OCD). At the same time, neuroimaging studies of OCD have had notable limitations, including reliance on relatively small samples. International collaborative efforts to increase statistical power by combining samples from across sites have been bolstered by the ENIGMA consortium; this provides specific technical expertise for conducting multi-site analyses, as well as access to a collaborative community of neuroimaging scientists. In this article, we outline the background to, development of, and initial findings from ENIGMA's OCD working group, which currently consists of 47 samples from 34 institutes in 15 countries on 5 continents, with a total sample of 2,323 OCD patients and 2,325 healthy controls. Initial work has focused on studies of cortical thickness and subcortical volumes, structural connectivity, and brain lateralization in children, adolescents and adults with OCD, also including the study on the commonalities and distinctions across different neurodevelopment disorders. Additional work is ongoing, employing machine learning techniques. Findings to date have contributed to the development of neurobiological models of OCD, have provided an important model of global scientific collaboration, and have had a number of clinical implications. Importantly, our work has shed new light on questions about whether structural and functional alterations found in OCD reflect neurodevelopmental changes, effects of the disease process, or medication impacts. We conclude with a summary of ongoing work by ENIGMA-OCD, and a consideration of future directions for neuroimaging research on OCD within and beyond ENIGMA.

Systematic Evaluation of Fluorination as Modification for Peptide-Based Fusion Inhibitors against HIV-1 Infection

With the emergence of novel viruses, the development of new antivirals is more urgent than ever. A key step in human immunodeficiency virus type 1 (HIV-1) infection is six-helix bundle formation within the envelope protein subunit gp41. Selective disruption of bundle formation by peptides has been shown to be effective; however, these drugs, exemplified by T20, are prone to rapid clearance from the patient. The incorporation of non-natural amino acids is known to improve these pharmacokinetic properties. Here, we evaluate a peptide inhibitor in which a critical Ile residue is replaced by fluorinated analogues. We characterized the influence of the fluorinated analogues on the biophysical properties of the peptide. Furthermore, we show that the fluorinated peptides can block HIV-1 infection of target cells at nanomolar levels. These findings demonstrate that fluorinated amino acids are appropriate tools for the development of novel peptide therapeutics.

Superelasticity of Plasma- and Synthetic Membranes Resulting from Coupling of Membrane Asymmetry, Curvature, and Lipid Sorting

Biological cells are contained by a fluid lipid bilayer (plasma membrane, PM) that allows for large deformations, often exceeding 50% of the apparent initial PM area. Isolated lipids self-organize into membranes, but are prone to rupture at small (<2-4%) area strains, which limits progress for synthetic reconstitution of cellular features. Here, it is shown that by preserving PM structure and composition during isolation from cells, vesicles with cell-like elasticity can be obtained. It is found that these plasma membrane vesicles store significant area in the form of nanotubes in their lumen. These act as lipid reservoirs and are recruited by mechanical tension applied to the outer vesicle membrane. Both in experiment and theory, it is shown that a "superelastic" response emerges from the interplay of lipid domains and membrane curvature. This finding allows for bottom-up engineering of synthetic biomaterials that appear one magnitude softer and with threefold larger deformability than conventional lipid vesicles. These results open a path toward designing superelastic synthetic cells possessing the inherent mechanics of biological cells.

Adaptive Self-Sealing Suction-Based Soft Robotic Gripper

While suction cups prevail as common gripping tools for a wide range of real-world parts and surfaces, they often fail to seal the contact interface when engaging with irregular shapes and textured surfaces. In this work, the authors propose a suction-based soft robotic gripper where suction is created inside a self-sealing, highly conformable and thin flat elastic membrane contacting a given part surface. Such soft gripper can self-adapt the size of its effective suction area with respect to the applied load. The elastomeric membrane covering edge of the soft gripper can develop an air-tight self-sealing with parts even smaller than the gripper diameter. Such gripper shows 4 times higher adhesion than the one without the membrane on various textured surfaces. The two major advantages, underactuated self-adaptability and enhanced suction performance, allow the membrane-based suction mechanism to grip various three-dimensional (3D) geometries and delicate parts, such as egg, lime, apple, and even hydrogels without noticeable damage, which can have not been gripped with the previous adhesive microstructures-based and active suction-based soft grippers. The structural and material simplicity of the proposed soft gripper design can have a broad use in diverse fields, such as digital manufacturing, robotic manipulation, transfer printing, and medical gripping.

Remote Modular Electronics for Wireless Magnetic Devices

Small-scale wireless magnetic robots and devices offer an effective solution to operations in hard-to-reach and high-risk enclosed places, such as inside the human body, nuclear plants, and vehicle infrastructure. In order to obtain functionalities beyond the capability of magnetic forces and torques exerted on magnetic materials used in these robotic devices, electronics need to be also integrated into them. However, their capabilities and power sources are still very limited compared to their larger-scale counterparts due to their much smaller sizes. Here, groups of milli/centimeter-scale wireless magnetic modules are shown to enable on-site electronic circuit construction and operation of highly demanding wireless electrical devices with no batteries, that is, with wireless power. Moreover, the mobility of the modular components brings remote modification and reconfiguration capabilities. When these small-scale robotic modules are remotely assembled into specific geometries, they can achieve, if not impossible, challenging electrical tasks for individual modules. Using such a method, several wireless and battery-free robotic devices are demonstrated using milli/centimeter-scale robotic modules, such as a wireless circuit to power light-emitting diodes with lower external fields, a device to actuate relatively high force-output shape memory alloy actuators, and a wireless force sensor, all of which can be modified on-site.

Chemical Vapor Deposition of Highly Conjugated, Transparent Boron Carbon Nitride Thin Films

Ternary materials made up only from the lightweight elements boron, carbon, and nitrogen are very attractive due to their tunable properties that can be obtained by changing the relative elemental composition. However, most of the times, the synthesis requires to use up to three different precursor and very high temperatures for the synthesis. Moreover, the low reciprocal solubility of boron nitride and graphene often leads to BN-C composite materials due to phase segregation. Herein, an innovative method is presented to prepare BCN thin films by chemical vapor deposition from a single source precursor, melamine diborate. The deposition occurs homogenously at relatively low temperatures generating very high degree of sp2 conjugation. The as-prepared thin films possess high transparency and refractive index values in the visible range that are of interest for reflective mirrors and lenses. Furthermore, they are wide-bandgap semiconductor with very positive valence band, making these materials very stable against oxidation of interest as protective coating and charge transport layer for solar cells. The simple chemical vapor deposition method that relies on commonly available and low-hazard precursor can open the way for application of BCN thin films in optics, optoelectronics, and beyond.

Plankton respiration in the Atacama Trench region: Implications for particulate organic carbon flux into the hadal realm

Respiration is a key process in the cycling of particulate matter and, therefore, an important control mechanism of carbon export to the ocean's interior. Most of the fixed carbon is lost in the upper ocean, and only a minor amount of organic material sustains life in the deep-sea. Conditions are particularly extreme in hadal trenches, and yet they host active biological communities. The source of organic carbon that supports them and the contribution of these communities to the ocean carbon cycle, however, remain uncertain. Here we report on size-fractionated depth profiles of plankton respiration assessed from the activity of the electron transport system in the Atacama Trench region, and provide estimates of the minimum carbon flux (FC) needed to sustain the respiratory requirements from the ocean surface to hadal waters of the trench and shallower nearby sites. Plankton < 100 μm contributed about 90% to total community respiration, whose magnitude was highly correlated with surface productivity. Remineralization rates were highest in the euphotic zone and declined sharply within intermediate oxygen-depleted waters, remaining fairly constant toward the bottom. Integrated respiration in ultra-deep waters (> 1000 m) was comparable to that found in upper layers, with 1.3 ± 0.4 mmol C m^-2 d^-1 being respired in the hadopelagic. The comparison between our FC models and estimates of sinking particle flux revealed a carbon imbalance through the mesopelagic that was paradoxically reduced at greater depths. We argue that large fast-sinking particles originated in the overlying surface ocean may effectively sustain the respiratory carbon demands in this ultra-deep marine environment.

Wireless MRI-Powered Reversible Orientation-Locking Capsule Robot

Magnetic resonance imaging (MRI) scanners do not provide only high-resolution medical imaging but also magnetic robot actuation and tracking. However, the rotational motion capabilities of MRI-powered wireless magnetic capsule-type robots have been limited due to the very high axial magnetic field inside the MRI scanner. Medical functionalities of such robots also remain a challenge due to the miniature robot designs. Therefore, a wireless capsule-type reversible orientation-locking robot (REVOLBOT) is proposed that has decoupled translational motion and planar orientation change capability by locking and unlocking the rotation of a spherical ferrous bead inside the robot on demand. Such an on-demand locking/unlocking mechanism is achieved by a phase-changing wax material in which the ferrous bead is embedded inside. Controlled and on-demand hyperthermia and drug delivery using wireless power transfer-based Joule heating induced by external alternating magnetic fields are the additional features of this robot. The experimental feasibility of the REVOLBOT prototype with steerable navigation, medical function, and MRI tracking capabilities with an 1.33 Hz scan rate is demonstrated inside a preclinical 7T small-animal MRI scanner. The proposed robot has the potential for future clinical use in teleoperated minimally invasive treatment procedures with hyperthermia and drug delivery capabilities while being wirelessly powered and monitored inside MRI scanners.

Spider-Inspired Electrohydraulic Actuators for Fast, Soft-Actuated Joints

The impressive locomotion and manipulation capabilities of spiders have led to a host of bioinspired robotic designs aiming to reproduce their functionalities; however, current actuation mechanisms are deficient in either speed, force output, displacement, or efficiency. Here-using inspiration from the hydraulic mechanism used in spider legs-soft-actuated joints are developed that use electrostatic forces to locally pressurize a hydraulic fluid, and cause flexion of a segmented structure. The result is a lightweight, low-profile articulating mechanism capable of fast operation, high forces, and large displacement; these devices are termed spider-inspired electrohydraulic soft-actuated (SES) joints. SES joints with rotation angles up to 70°, blocked torques up to 70 mN m, and specific torques up to 21 N m kg-1 are demonstrated. SES joints demonstrate high speed operation, with measured roll-off frequencies up to 24 Hz and specific power as high as 230 W kg-1 -similar to human muscle. The versatility of these devices is illustrated by combining SES joints to create a bidirectional joint, an artificial limb with independently addressable joints, and a compliant gripper. The lightweight, low-profile design, and high performance of these devices, makes them well-suited toward the development of articulating robotic systems that can rapidly maneuver.

Morphology of obligate ectosymbionts reveals Paralaxus gen. nov.: A new circumtropical genus of marine stilbonematine nematodes

Stilbonematinae are a subfamily of conspicuous marine nematodes, distinguished by a coat of sulphur-oxidizing bacterial ectosymbionts on their cuticle. As most nematodes, the worm hosts have a relatively simple anatomy and few taxonomically informative characters, and this has resulted in numerous taxonomic reassignments and synonymizations. Recent studies using a combination of morphological and molecular traits have helped to improve the taxonomy of Stilbonematinae but also raised questions on the validity of several genera. Here, we describe a new circumtropically distributed genus Paralaxus (Stilbonematinae) with three species: Paralaxus cocos sp. nov., P. bermudensis sp. nov. and P. columbae sp. nov. We used single worm metagenomes to generate host 18S rRNA and cytochrome c oxidase I (COI) as well as symbiont 16S rRNA gene sequences. Intriguingly, COI alignments and primer matching analyses suggest that the COI is not suitable for PCR-based barcoding approaches in Stilbonematinae as the genera have a highly diverse base composition and no conserved primer sites. The phylogenetic analyses of all three gene sets, however, confirm the morphological assignments and support the erection of the new genus Paralaxus as well as corroborate the status of the other stilbonematine genera. Paralaxus most closely resembles the stilbonematine genus Laxus in overlapping sets of diagnostic features but can be distinguished from Laxus by the morphology of the genus-specific symbiont coat. Our re-analyses of key parameters of the symbiont coat morphology as character for all Stilbonematinae genera show that with amended descriptions, including the coat, highly reliable genus assignments can be obtained.