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The spherical momentum distribution of the protons in ice is extracted from a high resolution deep inelastic neutron scattering experiment. Following a recent path integral Car-Parrinello molecular dynamics study, data were successfully interpreted in terms of an anisotropic Gaussian model, with a statistical accuracy comparable to that of the model independent scheme used previously, but providing more detailed information on the three dimensional potential energy surface experienced by the proton. A recently proposed theoretical concept is also employed to directly calculate the mean force from the experimental neutron Compton profile, and to evaluate the accuracy required to unambiguously resolve and extract the effective proton potential from the experimental data. [ABSTRACT FROM AUTHOR]

We show how a knot in a ring located upon a lattice may be characterized by two different measures of the perimeter length and by the mean square radius of gyration. This characterization is performed after the knot in a well-extended form has been reduced in size by a process that involves bead elimination and bead movement, movements being governed alternately by two criteria, the need to reduce the total length of the perimeter (or at least not to increase it) and the need to move a bead closer to the center of gravity of the object, so that elimination may subsequently take place. During contractions the beads must occupy different sites upon the lattice and bonds between pairs of beads are not permitted to pass through each other, so their topology is maintained. For the first few knots of the knot table the number of bonds, Nb (or the number of beads) is useful in discriminating, though unique values are found only for the 31 and 41 knots. The mean number of bonds within a contracted knot is a good measure of the crossing number, as also are the second and third measures of knot size, the mean perimeter length, and the radius of gyration. None of these measures are capable of readily distinguishing between different knots with the same number of crossings. Compacted knots themselves have a number of configurations upon the lattice that have interesting properties. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A decade of British experience in assessing and reporting higher orderlearning using a scale of national standards has important lessons for countriescurrently embarking on programmes of standards-based education reform. Thearchitects of the British National Curriculum envisaged that the reliabilityof measures of higher order learning could be assured through a comprehensiveauditing programme involving expert teachers. However, plans for a nationalauditing programme in Britain were never realised for financial reasons. Thisarticle argues that, in the absence of orthodox auditing procedures, moderninformation handling techniques have an important role to play in enhancingthe technical fidelity of instruments for measuring higher order learning,by making the combined professional wisdom of experienced teachers availableto the assessor at the time of marking. The higher order skill of creativewriting is used to illustrate the calibration of a systemically valid computerisedassessment tool, applicable to any standards-based assessment framework. [ABSTRACT FROM AUTHOR]

Translocation renal cell carcinoma (tRCC) is an aggressive subtype of kidney cancer driven by TFE3 gene fusions, which act via poorly characterized downstream mechanisms. Here we report that TFE3 fusions transcriptionally rewire tRCCs toward oxidative phosphorylation (OXPHOS), contrasting with the highly glycolytic nature of most other renal cancers. Reliance on this TFE3 fusion-driven OXPHOS programme renders tRCCs vulnerable to NADH reductive stress, a metabolic stress induced by an imbalance of reducing equivalents. Genome-scale CRISPR screening identifies tRCC-selective vulnerabilities linked to this metabolic state, including EGLN1, which hydroxylates HIF-1α and targets it for proteolysis. Inhibition of EGLN1 compromises tRCC cell growth by stabilizing HIF-1α and promoting metabolic reprogramming away from OXPHOS, thus representing a vulnerability for OXPHOS-dependent tRCC cells. Our study defines tRCC as being dependent on a mitochondria-centred metabolic programme driven by TFE3 fusions and nominates EGLN1 inhibition as a therapeutic strategy in this cancer., Competing Interests: Competing interests: S.R.V. has consulted for Jnana Therapeutics within the past 3 years and receives research support from Bayer. L.B.-P. is a co-founder, holds equity in and is a consultant for Scorpion Therapeutics. T.K.C. reports institutional and/or personal paid and/or unpaid support for research, advisory board, consultancy, and/or honoraria past 5 years from Alkermes, Arcus Bio, AstraZeneca, Aravive, Aveo, Bayer, Bristol Myers Squibb, Bicycle Therapeutics, Calithera, Circle Pharma, Deciphera Pharmaceuticals, Eisai, EMD Serono, Exelixis, GSK, Gilead, HiberCell, IQVA, Infinity, Institut Servier, Ipsen, Jansen, Kanaph, Lilly, Merck, Nikang, Neomorph, Nuscan/PrecedeBio, Novartis, Oncohost, Pfizer, Roche, Sanofi/Aventis, Scholar Rock, Surface Oncology, Takeda, Tempest, Up-To-Date, CME and non-CME events (Mashup Media Peerview, OncLive, MJH, CCO and others), outside the submitted work; institutional patents filed on molecular alterations and immunotherapy response/toxicity, and ctDNA; equity from Tempest, Pionyr, Osel, PrecedeBio, CureResponse, InnDura Therapeutics, and Primium, Abalytics; is a committee member for NCCN, the GU Steering Committee, ASCO, ESMO, ACCRU, and KidneyCan; medical writing and editorial assistance support that might have been founded by communications companies in part, no speaker’s bureau; mentored several non-US citizens on research projects with potential funding (in part) from non-US sources/foreign components; the institution (Dana-Farber Cancer Institute) may have received additional independent funding of drug companies or/and royalties potentially involved in research around the subject matter. S.S. reports receiving commercial research grants from Bristol Myers Squibb, AstraZeneca, Exelixis and Novartis; is a consultant/advisory board member for Merck & Co., Rahway, NJ, AstraZeneca, Bristol Myers Squibb, CRISPR Therapeutics AG, AACR and NCI; and receives royalties from Biogenex. The other authors declare no competing interests., (© 2025. The Author(s), under exclusive licence to Springer Nature Limited.)

Introduction: Spinal cord infarction is a rare but often devastating disorder. The pathogenesis of most non-surgical cases involves atherothrombosis and treatment with anticoagulation and antiplatelet agents may be indicated. Functional recovery in most cases is poor. We describe five cases of spinal cord infarction and provide details on their functional outcomes after long-term (>10 years) follow-up., Case Presentation: A 28-year-old female presented at 16 weeks gestation with chest and back pain and paraesthesia in her fingers. Magnetic resonance imaging on admission revealed a spinal cord lesion extending from C5-T8. She was treated with anticoagulation and rehabilitation. Six years following presentation she was able to return to work. A 42-year-old male experiencing central chest pain and leg weakness was initially diagnosed as having acute coronary syndrome. Following discharge, he was re-admitted with urinary retention and leg weakness. Magnetic resonance imaging revealed a spinal cord lesion extending from T4 to T7. He was treated with anticoagulation, and eight months following presentation he regained full muscle strength but required intermittent self-catherisation. Three further cases are described., Discussion: The aetiology of non-surgical spinal cord infarction is not always evident, but is commonly associated with atherothrombosis. There are often delays in making a diagnosis, but early recognition and prompt treatment of spinal cord infarction is essential. Long-term functional outcomes are often poor and typically reflect the severity of initial presentation. This case series is unique as it has one of the longest follow-up periods described in the literature., (© 2024. Crown.)

Xp11 translocation renal cell carcinoma (tRCC) is a rare, female-predominant cancer driven by a fusion between the transcription factor binding to IGHM enhancer 3 (TFE3) gene on chromosome Xp11.2 and a partner gene on either chromosome X (chrX) or an autosome. It remains unknown what types of rearrangements underlie TFE3 fusions, whether fusions can arise from both the active (chrXa) and inactive X (chrXi) chromosomes, and whether TFE3 fusions from chrXi translocations account for the female predominance of tRCC. To address these questions, we performed haplotype-specific analyses of chrX rearrangements in tRCC whole genomes. We show that TFE3 fusions universally arise as reciprocal translocations and that oncogenic TFE3 fusions can arise from chrXi:autosomal translocations. Female-specific chrXi:autosomal translocations result in a 2:1 female-to-male ratio of TFE3 fusions involving autosomal partner genes and account for the female predominance of tRCC. Our results highlight how X chromosome genetics constrains somatic chrX alterations and underlies cancer sex differences., Competing Interests: Declaration of interests S.R.V. has consulted for Jnana Therapeutics within the past 3 years and receives research support from Bayer. C.-Z.Z. is a co-founder, consultant, and equity holder of Pillar Biosciences, a for-profit company specialized in assay development for targeted DNA sequencing. C.B. is currently an employee of Inocras Inc., a for-profit company specialized in whole-genome sequencing of cancer and rare diseases. T.K.C. reports institutional and/or personal, paid and/or unpaid support for research, advisory boards, consultancy, and/or honoraria past 5 years, ongoing or not, from Alkermes, Arcus Bio, AstraZeneca, Aravive, Aveo, Bayer, Bristol Myers Squibb, Calithera, Circle Pharma, Deciphera Pharmaceuticals, Eisai, EMD Serono, Exelixis, GlaxoSmithKline, Gilead, HiberCell, IQVA, Infinity, Ipsen, Jansen, Kanaph, Lilly, Merck, Nikang, Neomorph, Nuscan/PrecedeBio, Novartis, Oncohost, Pfizer, Roche, Sanofi/Aventis, Scholar Rock, Surface Oncology, Takeda, Tempest, Up-To-Date, CME events (Peerview, OncLive, MJH, CCO, and others), and outside the submitted work; has institutional patents filed on molecular alterations and immunotherapy response/toxicity and ctDNA; holds equity in Tempest, Pionyr, Osel, Precede Bio, CureResponse, InnDura Therapeutics, and Primium; and is on the committees of NCCN, GU Steering Committee, ASCO (BOD 6-2024-, ESMO, ACCRU, and KidneyCan (medical writing and editorial assistance support may have been funded by Communications companies in part); and has mentored several non-US citizens on research projects with potential funding (in part) from non-US sources/Foreign Components. The institution (Dana-Farber Cancer Institute) may have received additional independent funding of drug companies or/and royalties potentially involved in research around the subject matter. D.J.E. received research funding to institution from Bristol-Myers Squibb, Cardiff Oncology, MiNK Therapeutics, Novartis, Sanofi, and Puma. Discounted research sequencing from Foundation Medicine., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Translocation renal cell carcinoma (tRCC) is an aggressive subtype of kidney cancer driven by TFE3 gene fusions, which act via poorly characterized downstream mechanisms. Here we report that TFE3 fusions transcriptionally rewire tRCCs toward oxidative phosphorylation (OXPHOS), contrasting with the highly glycolytic metabolism of most other renal cancers. This TFE3 fusion-driven OXPHOS program, together with heightened glutathione levels found in renal cancers, renders tRCCs sensitive to reductive stress - a metabolic stress state induced by an imbalance of reducing equivalents. Genome-scale CRISPR screening identifies tRCC-selective vulnerabilities linked to this metabolic state, including EGLN1 , which hydroxylates HIF-1α and targets it for proteolysis. Inhibition of EGLN1 compromises tRCC cell growth by stabilizing HIF-1a and promoting metabolic reprogramming away from OXPHOS, thus representing a vulnerability to OXPHOS-dependent tRCC cells. Our study defines a distinctive tRCC-essential metabolic program driven by TFE3 fusions and nominates EGLN1 inhibition as a therapeutic strategy to counteract fusion-induced metabolic rewiring., Competing Interests: Declaration of Interests S.R.V. has consulted for Jnana Therapeutics within the past 3 years and receives research support from Bayer. L.B-P. is a co-founder, holds equity in and is a consultant for Scorpion Therapeutics.

Xp11 translocation renal cell carcinoma (tRCC) is a female-predominant kidney cancer driven by translocations between the TFE3 gene on chromosome Xp11.2 and partner genes located on either chrX or on autosomes. The rearrangement processes that underlie TFE3 fusions, and whether they are linked to the female sex bias of this cancer, are largely unexplored. Moreover, whether oncogenic TFE3 fusions arise from both the active and inactive X chromosomes in females remains unknown. Here we address these questions by haplotype-specific analyses of whole-genome sequences of 29 tRCC samples from 15 patients and by re-analysis of 145 published tRCC whole-exome sequences. We show that TFE3 fusions universally arise as reciprocal translocations with minimal DNA loss or insertion at paired break ends. Strikingly, we observe a near exact 2:1 female:male ratio in TFE3 fusions arising via X:autosomal translocation (but not via X inversion), which accounts for the female predominance of tRCC. This 2:1 ratio is at least partially attributable to oncogenic fusions involving the inactive X chromosome and is accompanied by partial re-activation of silenced chrX genes on the rearranged chromosome. Our results highlight how somatic alterations involving the X chromosome place unique constraints on tumor initiation and exemplify how genetic rearrangements of the sex chromosomes can underlie cancer sex differences., Competing Interests: Competing Interests: S.R.V. has consulted for Jnana Therapeutics, MPM Capital, and Vida Ventures within the past 3 years; receives research support from Bayer; and his spouse is an employee of and holds equity in Kojin Therapeutics. C.-Z. Zhang is a co-founder, consultant, and equity holder of Pillar Biosciences, a for profit company specialized in assay development for targeted DNA sequencing. T.K.C.: Institutional and/or personal, paid and/or unpaid support for research, advisory boards, consultancy, and/or honoraria past 5 years and ongoing, from: Alkermes, AstraZeneca, Aravive, Aveo, Bayer, Bristol Myers-Squibb, Calithera, Circle Pharma, Deciphera Pharmaceuticals, Eisai, EMD Serono, Exelixis, GlaxoSmithKline, Gilead, IQVA, Infinity, Ipsen, Jansen, Kanaph, Lilly, Merck, Nikang, Nuscan, Novartis, Oncohost, Pfizer, Roche, Sanofi/Aventis, Scholar Rock, Surface Oncology, Takeda, Tempest, Up-To-Date, CME events (Peerview, OncLive, MJH, CCO and others), outside the submitted work. Institutional patents filed on molecular alterations and immunotherapy response/toxicity, and ctDNA. Equity: Tempest, Pionyr, Osel, Precede Bio, CureResponse, InnDura. Committees: NCCN, GU Steering Committee, ASCO/ESMO, ACCRU, KidneyCan. • Medical writing and editorial assistance support may have been funded by Communications companies in part. No speaker’s bureau. Mentored several non-US citizens on research projects with potential funding (in part) from non-US sources/Foreign Components. The institution (Dana-Farber Cancer Institute) may have received additional independent funding of drug companies or/and royalties potentially involved in research around the subject matter. D.J.E.: Research funding to institution from Bristol-Myers Squibb, Cardiff Oncology, MiNK Therapeutics, Novartis, Sanofi, Puma. Discounted research sequencing from Foundation Medicine.

How memory shapes animals' movement paths is a topic of growing interest in ecology, with connections to planning for conservation and climate change. Empirical studies suggest that memory has both temporal and spatial components, and can include both attractive and aversive elements. Here, we introduce reinforced diffusions (the continuous time counterpart of reinforced random walks) as a modelling framework for understanding the role that memory plays in determining animal movements. This framework includes reinforcement via functions of time before present and of distance away from a current location. Focusing on the interplay between memory and central place attraction (a component of home ranging behaviour), we explore patterns of space usage that result from the reinforced diffusion. Our efforts identify three qualitatively different behaviours: bounded wandering behaviour that does not collapse spatially, collapse to a very small area, and, most intriguingly, convergence to a cycle. Subsequent applications show how reinforced diffusion can create movement trajectories emulating the learning of movement routes by homing pigeons and consolidation of ant travel paths. The mathematically explicit manner with which assumptions about the structure of memory can be stated and subsequently explored provides linkages to biological concepts like an animal's 'immediate surroundings' and memory decay.

Inverse vulcanization, a sustainable platform, can transform sulfur, an industrial by-product, into polymers with broad promising applications such as heavy metal capture, electrochemistry and antimicrobials. However, the process usually requires high temperatures (≥159 °C), and the crosslinkers needed to stabilize the sulfur are therefore limited to high-boiling-point monomers only. Here, we report an alternative route for inverse vulcanization-mechanochemical synthesis, with advantages of mild conditions (room temperature), short reaction time (3 h), high atom economy, less H 2 S, and broader monomer range. Successful generation of polymers using crosslinkers ranging from aromatic, aliphatic to volatile, including renewable monomers, demonstrates this method is powerful and versatile. Compared with thermal synthesis, the mechanochemically synthesized products show enhanced mercury capture. The resulting polymers show thermal and light induced recycling. The speed, ease, versatility, safety, and green nature of this process offers a more potential future for inverse vulcanization, and enables further unexpected discoveries., (© 2022. The Author(s).)

The generation of hydrogen from water using light is currently one of the most promising alternative energy sources for humankind but faces significant barriers for large-scale applications due to the low efficiency of existing photo-catalysts. In this work we propose a new route to fabricate nano-hybrid materials able to deliver enhanced photo-catalytic hydrogen evolution, combining within the same nanostructure, a plasmonic antenna nanoparticle and semiconductor quantum dots (QDs). For each stage of our fabrication process we probed the chemical composition of the materials with nanometric spatial resolution, allowing us to demonstrate that the final product is composed of a silver nanoparticle (AgNP) plasmonic core, surrounded by satellite Pt decorated CdS QDs (CdS@Pt), separated by a spacer layer of SiO 2 with well-controlled thickness. This new type of photoactive nanomaterial is capable of generating hydrogen when irradiated with visible light, displaying efficiencies 300% higher than the constituting photo-active components. This work may open new avenues for the development of cleaner and more efficient energy sources based on photo-activated hydrogen generation.

Hydration layers play a key role in many technical and biological systems, but our understanding of these structures remains very limited. Here, we investigate the molecular processes driving hydration of a chiral metal-organic surface, bitartrate on Cu(110), which consists of hydrogen-bonded bitartrate rows separated by exposed Cu. Initially water decorates the metal channels, hydrogen bonding to the exposed O ligands that bind bitartrate to Cu, but does not wet the bitartrate rows. At higher temperature, water inserts into the structure, breaks the existing intermolecular hydrogen bonds, and changes the adsorption site and footprint. Calculations show this process is driven by the creation of stable adsorption sites between the carboxylate ligands, to allow hydration of O-Cu ligands within the interior of the structure. This work suggests that hydration of polar metal-adsorbate ligands will be a dominant factor in many systems during surface hydration or self-assembly from solution.

Titanium implants in orthopedic applications can fail due to infection and impaired integration into the host. Most research efforts that facilitate osseointegration of the implant have not considered infection, and vice versa. Moreover, most infection control measures involve the use of conventional antibiotics which contributes to the global epidemic of antimicrobial resistance. Nitric oxide (NO) is a promising alternative to antibiotics, and while researchers have investigated NO releasing coatings, there are few reports on the function/robustness or the mechanism of NO release. Our comprehensive mechanistic study has allowed us to design, characterize, and optimize NO releasing coatings to achieve maximum antimicrobial efficacy toward bacteria with minimum cytotoxicity to human primary osteoblasts in vitro . As the antibiotic era is coming to an end and the future of infection control continues to demand new alternatives, the coatings described herein represent a promising therapeutic strategy for use in orthopedic surgeries.

Making new van der Waals materials with electronic or magnetic functionality is a chemical design challenge for the development of two-dimensional nanoelectronic and energy conversion devices. We present the synthesis and properties of the van der Waals material Bi 4 O 4 SeCl 2 , which is a 1:1 superlattice of the structural units present in the van der Waals insulator BiOCl and the three-dimensionally connected semiconductor Bi 2 O 2 Se. The presence of three anions gives the new structure both the bridging selenide anion sites that connect pairs of Bi 2 O 2 layers in Bi 2 O 2 Se and the terminal chloride sites that produce the van der Waals gap in BiOCl. This retains the electronic properties of Bi 2 O 2 Se while reducing the dimensionality of the bonding network connecting the Bi 2 O 2 Se units to allow exfoliation of Bi 4 O 4 SeCl 2 to 1.4 nm height. The superlattice structure is stabilized by the configurational entropy of anion disorder across the terminal and bridging sites. The reduction in connective dimensionality with retention of electronic functionality stems from the expanded anion compositional diversity.

As the current global threat of antimicrobial resistance (AMR) persists, developing alternatives to antibiotics that are less susceptible to resistance is becoming an urgent necessity. Recent advances in biomaterials have allowed for the development and fabrication of materials with discrete surface nanotopographies that can deter bacteria from adhering to their surface. Using binary polymer blends of polystyrene (PS), poly(methyl methacrylate) (PMMA) and polycaprolactone (PCL) and varying their relative concentrations, PS/PCL, PS/PMMA and PCL/PMMA polymer demixed thin films were developed with nanoisland, nanoribbon and nanopit topographies. In the PS/PCL system, PS segregates to the air-polymer interface, with the lower solubility PCL preferring the substrate-polymer interface. In the PS/PMMA and PCL/PMMA systems, PMMA prefers the air-polymer interface due to its greater solubility and lower surface energy. The anti-adhesion efficacy of the demixed films were tested against Pseudomonas aeruginosa (PA14). PS/PCL and PCL/PMMA demixed films showed a significant reduction in cell counts adhered on their surfaces compared to pure polymer control films, while no reduction was observed in the counts adhered on PS/PMMA demixed films. While the specific morphology did not affect the adhesion, a relationship between bacterial cell and topographical surface feature size was apparent. If the surface feature was smaller than the cell, then an anti-adhesion effect was observed; if the surface feature was larger than the cell, then the bacteria preferred to adhere., Competing Interests: The authors declare no conflict of interest.

Smart antimicrobial surfaces are a powerful tool to prevent bacterial colonization at surfaces. In this work, we report a successful strategy for the functionalization of polydimethylsiloxane (PDMS) surfaces, widely used in medical devices, with salicylic acid (SA), a biocide approved for use in humans. Antimicrobial PDMS surfaces were fabricated via a rational design in which bifunctional silane linker molecules were covalently grafted onto the PDMS via one end, while soft intermolecular interactions with SA were generated at the other end to enable reversible load and release of the biocide. A molecular level understanding of the interface was obtained using attenuated total reflectance Fourier transform infrared, Raman, and X-ray photoelectron spectroscopies, alongside density functional theory calculations. These reveal that the linker molecules dock the SA molecules at the surface via a 1:1 complexation interaction. Furthermore, each 1:1 complex acts as a nucleation point onto which multiple stacks of the biocide are subsequently stabilized via a combination of H-bonding and π-π stacking interactions, thus significantly enhancing SA uptake at the interface. The antimicrobial activity of these surfaces against model Gram-negative and Gram-positive bacteria represented by Escherichia coli , Staphylococcus aureus , and Staphylococcus epidermidis is demonstrated by a log 6 reduction of planktonic bacterial populations and an efficient anti-biofilm activity at the surface.

Heterogeneous ice nucleation at solid surfaces impacts many areas of science, from environmental processes, such as precipitation, to microbiological systems and food processing, but the microscopic mechanisms underpinning nucleation remain unclear. Discussion of ice growth has often focused around the role of the surface in templating the structure of water, forcing the first layer to adopt the registry of the underlying substrate rather than that of ice. To grow a thick ice film, water in the first few ice layers must accommodate this strain, but understanding how this occurs requires detailed molecular-scale information that is lacking. Here we combine scanning tunneling microscopy, low-energy electron diffraction, and work-function measurements with electronic structure calculations to investigate the initial stages of ice growth on a Pt alloy surface, having a lattice spacing 6% larger than ice. Although the first layer of water forms a strictly commensurate hexagonal network, this behavior does not extend to the second layer. Instead, water forms a 2D structure containing extended defect rows made from face-sharing pentamer and octamer rings. The defect rows allow the majority of second-layer water to remain commensurate with the solid surface while compensating lateral strain by increasing the water density close to that of an ice surface. The observation of octamer-pentamer rows in ice films formed on several surfaces suggests that the octamer-pentamer defect motif acts as a flexible strain relief mechanism in thin ice films, providing a mechanism that is not available during the growth of strained films in other materials, such as semiconductors.

The ability of nitric oxide (NO)-releasing polymer coatings to prevent biofilm formation is described. NO-releasing coatings on (poly(ethylene terephthalate) (PET) and silicone elastomer (SE)) were fabricated using aminosilane precursors. Pristine PET and SE were oxygen plasma treated, followed by immobilisation of two aminosilane molecules: N -(3-(trimethoxysilyl)propyl)diethylenetriamine (DET3) and N -(3-trimethoxysilyl)propyl)aniline (PTMSPA). N -diazeniumdiolate nitric oxide donors were formed at the secondary amine sites on the aminosilane molecules producing NO-releasing polymeric coatings. The NO payload and release were controlled by the aminosilane precursor, as DET3 has two secondary amine sites and PTMSPA only one. The antibacterial efficacy of these coatings was tested using a clinical isolate of Pseudomonas aeruginosa (PA14). All NO-releasing coatings in this study were shown to significantly reduce P. aeruginosa adhesion over 24 h with the efficacy being a function of the aminosilane modification and the underlying substrate. These NO-releasing polymers demonstrate the potential and utility of this facile coating technique for preventing biofilms for indwelling medical devices., Competing Interests: The authors declare no conflict of interest.

The linker-free covalent immobilization of polymers on surfaces has the potential to impart new properties and functions to surfaces for a wide range of applications. However, most current methods for the production of these surfaces involve multiple chemical steps and do not have a high degree of control over the chemical functionalities at the surface. A comprehensive study detailing the facile two-step covalent grafting of the antimicrobial peptide nisin onto polystyrene surfaces is reported. Functionalization is achieved using an atmospheric pressure plasma jet, and the reaction is monitored and compared with a standard wet chemical functionalization approach using a variety of analytical techniques. The reactive species produced by the atmospheric pressure plasma jet were analyzed by mass spectrometry and optical emission spectroscopy. The surface chemistry and topography of the functionalized surfaces were determined using contact angle measurements, Fourier infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy and atomic force microscopy respectively. Following surface analysis, the antimicrobial efficacy of the covalently grafted nisin against two major food borne pathogens (Staphylococcus aureus and Listeria monocytogenes) was assessed at two different pHs. The results demonstrated that a post-plasma treatment step after nisin deposition is required to covalently graft the peptide onto the surface. The covalent immobilization of nisin resulted in a significant reduction in bacterial counts within a short 30 minutes contact time. These surfaces were also significantly more antimicrobial compared to those prepared via a more traditional wet chemical approach indicating that the reported method could be a less expensive and less time consuming alternative.

The performance of solar-thermal conversion systems can be improved by incorporation of nanocarbon-stabilized microencapsulated phase change materials (MPCMs). The geometry of MPCMs in the microcapsules plays an important role for improving their heating efficiency and reliability. Yet few efforts have been made to critically examine the formation mechanism of different geometries and their effect on MPCMs-shell interaction. Herein, through changing the cooling rate of original emulsions, we acquire MPCMs within the nanocarbon microcapsules with a hollow structure of MPCMs (h-MPCMs) or solid PCM core particles (s-MPCMs). X-ray photoelectron spectroscopy and atomic force microscopy reveals that the capsule shell of the h-MPCMs is enriched with nanocarbons and has a greater MPCMs-shell interaction compared to s-MPCMs. This results in the h-MPCMs being more stable and having greater heat diffusivity within and above the phase transition range than the s-MPCMs do. The geometry-dependent heating efficiency and system stability may have important and general implications for the fundamental understanding of microencapsulation and wider breadth of heating generating systems.