Negative Template Research Articles

Why are some individuals better at using negative attentional templates to suppress distractors? Exploration of interindividual differences in cognitive control efficiency.

Negative templates are based on foreknowledge of distractor features and can lead to more efficient visual search at the group level. However, large individual differences exist in the size of benefits induced by negative cues. The cognitive factors underlying these interindividual differences remain unknown. Previous research has suggested higher engagement of proactive control for negative templates compared to positive templates. We thus hypothesized that interindividual differences in proactive control efficiency may explain the large variability in negative cue benefits. A large data set made up of data from two previously published studies was reanalyzed (N = 139), with eye movements recorded in 36 participants. Individual proactive control efficiency was measured through reaction time (RT) variability. Participants with higher proactive control efficiency exhibited larger benefits after negative cues across two critical measures: Individuals with higher proactive control showed larger RT benefits following negative compared to neutral cues; similarly, individuals with higher proactive control exhibited lower first saccades to cued distractor items. No such relationship was observed for positive cues. Our results confirmed the existence of large interindividual differences in the benefits induced by negative attentional templates. Critically, we show that proactive control drives these interindividual differences in negative template use. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Superhydrophobic surface of biomass carbon-based PANI composite coatings with the biomimetic structure of goose feather for anticorrosion/antibiofilm applications

Biomass carbon (BMC)-based polyaniline (PANI) composite coatings with superhydrophobic biomimetic surfaces were fabricated through nanocasting to transfer the surface of natural goose feather (GF) to the polymer surface for anticorrosion and antibiofilm applications. First, the as-synthesized PANI powder without/with 1 wt% BMC was dissolved/dispersed in N-methyl-2-pyrrolidone and then dropwise added onto the negative soft template of polydimethylsiloxane, successfully transferring the pattern of natural GF surface to a series of biomimetic PANI coating surfaces (denoted by Bio-PANI and Bio-PANI-1). Scanning electron microscopy (SEM) investigated the surface morphology of biomimetic coatings and revealed the presence of micron-sized rachis decorated with many nanoscaled barbules. Compared with that for non-Bio-PANI coating, the contact angle (CA) increased from 92.88° ± 0.81° to 144.94° ± 0.87° for Bio-PANI and 152.46° ± 1.95°for Bio-PANI-1. For anticorrosion application, the electrochemical corrosion potential (Ecorr)/impedance (Z’) of PANI coating increased significantly (from −633.62 mV/7.41 × 105 Ω to −319.87 mV/1.05 × 107 Ω) compared with that of Bio-PANI-1 coating, indicating that the Bio-PANI composite superhydrophobic coating exhibited the best anticorrosion performance. For antibiofilm application, three types of bacteria (i.e., Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) were used to study long-term antibiofilm formation. The findings revealed that the superhydrophobic Bio-PANI-1 coated surface inhibited bacterial growth and hindered biofilm development. Furthermore, the inherent hydrophobicity of this surface played a crucial role in warding off bacterial adhesion, ensuring impressive sustained antibiofilm efficacy.

Effects and considerations of multiplexing ForenSeq Kintelligence libraries with a negative control.

The negative template control or negative amplification control has been an essential component of the forensic DNA analysis workflow that helps monitor contamination. As such, the inclusion of a negative control in forensic DNA analysis has been a requirement for all laboratories audited under the FBI's Quality Assurance Standards. As massively parallel sequencing (MPS) becomes more conventional in forensic laboratories, considerations for the inclusion of a negative control in every sequencing run can be evaluated. Although the inclusion of a negative control in library preparation and the first sequencing run has a practical function, there is less utility for its inclusion in all subsequent sequencing runs for that library preparation. Although this is universal to all MPS assays, it is most relevant for an assay that has a low sample multiplexing capacity, such as the ForenSeq Kintelligence Kit (Qiagen/Verogen, Inc.). The ForenSeq Kintelligence Kit is an investigative genetic genealogy (IGG) sequencing-based assay that targets 10,230 forensically relevant single-nucleotide polymorphisms. The manufacturer recommends multiplexing 3 libraries per sequencing run, which includes controls. The purpose of this study was to investigate the effect of the inclusion of a negative control in every Kintelligence sequencing run. We observed that the library generated from a negative amplification control will take 7%-14% of the run output. The loss of sequencing space taken by a negative control decreased the available output for DNA-containing samples, leading in some cases to allele or locus dropout and accompanying higher numbers of sixth to seventh order unknown associations in GEDmatch PRO.

Within-Subject manipulations of proactive control do not change negative templates benefits: Exploring the effect of reward on negative and positive cues

ABSTRACT Negative templates come from foreknowledge of distractor-features and improve visual search performance. Recent studies characterizing the mechanisms underlying these benefits, show a critical role of proactive control mechanisms in negative template use. The goal of this study was to test if state-based fluctuations of proactive control play a role in negative template use. We used motivation (e.g., rewards) to induce within-individual fluctuations of proactive control efficiency during visual search. We replicated previous findings for the positive templates, with faster RT to find the target during periods of high- compared to low-reward conditions. Interestingly, we found no effect of motivation on the use of negative templates, even when a motivation condition led to faster RTs. Taken together, these results bring new evidence that using negative templates is not modulated by within-individual fluctuations of proactive engagement and is likely more related to trait-based aspects of an individual's proactive control ability.

Nanocasting technique for imprinting a natural leaf pattern on biomimetic polyaniline to yield an artificial hierarchical surface structure for gas sensing

Hydrogen sulfide (H2S) posed substantial safety risks in industrial settings due to its odorless and toxic nature and necessitated vigilant detection. With the burgeoning importance of H2S gas sensing applications, this study focused on the synthesis and utilization of a novel biomimetic material aimed at advancing gas sensing capabilities. Biomimetic polyaniline (Bio-PANI) with an artificial hierarchical surface structure was fabricated through the innovative nanocasting technique. This technique involved the replication of the surface pattern of a natural Xanthosoma sagittifolium leaf (XSL) onto a PANI coating, achieved using a negative template. In comparison to PANI, Bio-PANI showcased higher specific surface area (160 m2/g versus 41 m2/g of PANI) and exhibited significantly amplified reversible redox and doping–dedoping capacities. The application of Bio-PANI and PANI coatings on interdigitated electrodes (IDEs) allowed for gas-sensing assessments. These evaluations encompassed as-prepared IDE sensor’s responsivity, selectivity, repeatability, and stability. Notably, the Bio-PANI-coated IDE sensor showed larger response (185% versus 27% of PANI toward a 10 ppm concentration of H2S), a consequence of their substantially larger specific surface area and greater electrochemical performances when contrasted with PANI-coated IDE sensor. In addition, Bio-PANI-coated IDE sensor exhibited better selectivity, repeatability, long-term stability, and moisture resistance.

CO2 Electrolysis: From Model Metal Foams to Gas Diffusion Electrodes Using Dynamic Hydrogen Bubble Templation

On the road to a clean and sustainable energy production, reducing our greenhouse gas emissions is of utmost importance. It is already well known that the electrochemical reduction reaction of carbon dioxide (CO2RR) to valuable products can contribute to this goal by power-to-X technology1, 2. Hereby, amongst other factors, the choice of the electrocatalyst material defines the final product spectrum. For instance, the noble metal Ag shows very high selectivities in the conversion of carbon dioxide to carbon monoxide and achieves faradaic conversion efficiencies close to 100 %. High conversion rates and the efficiency of the reduction process itself are necessary to make the process industrially viable. To enhance the conversion, highly catalytically active porous electrodes with increased surface area are required. A fast and simple way to produce these electrodes without the use of solvents is the hydrogen bubble templating (DHBT) method3, 4. This technique takes advantage of the hydrogen evolution reaction (HER). By applying sufficiently high overpotentials, metal ions are reduced and electrochemically deposited, while simultaneously the bubbles originating from HER work as a dissolving negative template for the metal to grow around, thereby forming macro-porous layers and nanoscale interconnecting foam walls.To find out the optimal manufacturing parameters, the activity of electrochemically deposited metal foams for the CO2RR is determined in model systems using an H-cell first. Combining the characterization of such intricate foam electrodes using physicochemical and microscopic techniques in conjunction with electrochemical analyses provides us with an in-depth insight into the structure of the carefully tailored electrodes. By elucidating the morphology, we were able to link the electrochemical deposition at higher current densities to a more homogenous and denser structure, which in turn achieved better performances in the conversion of CO2 to valuable products.Although catalyst design and its effects on the CO2RR performance can be studied in H-cells very easily, the transfer of these model foam electrodes towards gas-fed electrodes is necessary to take the next development step towards industrial application and to approach higher TRLs. By avoiding solvation limits of CO2 in aqueous electrolytes and thereby decreasing its diffusion length, gas diffusion electrodes can accomplish industrially required current densities by intense contact between the liquid and the gas phase with the catalytically active surfaces within the metallic electrodes. Herein, we will demonstrate how the DHBT method can be used to produce gas diffusion electrodes for application in the CO2RR within minutes. A. Bagger, W. Ju, A. S. Varela, P. Strasser and J. Rossmeisl, Chemphyschem : a European journal of chemical physics and physical chemistry, 18(22), 3266–3273 (2017).S. Vesztergom, A. Dutta, M. Rahaman, K. Kiran, I. Zelocualtecatl Montiel and P. Broekmann, ChemCatChem, 13(4), 1039–1058 (2021).K. Klingan, T. Kottakkat, Z. P. Jovanov, S. Jiang, C. Pasquini, F. Scholten, P. Kubella, A. Bergmann, B. Roldan Cuenya, C. Roth and H. Dau, ChemSusChem, 11(19), 3449–3459 (2018).T. Kottakkat, K. Klingan, S. Jiang, Z. P. Jovanov, V. H. Davies, G. A. M. El-Nagar, H. Dau and C. Roth, ACS applied materials & interfaces, 11(16), 14734–14744 (2019).

Neurophysiological Measures of Proactive and Reactive Control in Negative Template Use.

In a visual search task, knowing features of distractors in advance leads to a more efficient visual search. Although previous studies suggested that the benefits of these negative cues rely on attentional control, it is unclear whether proactive or reactive control is involved. In this study, we analyzed the EEG data of participants performing a visual search task (n = 14). Participants searched for a shape-defined target after receiving a positive cue (target color), negative cue (distractor color), or neutral cue (non-informative). To examine proactive control, we measured EEG after the cue onset but before visual search. Our time-frequency analysis revealed a higher power of theta oscillations over frontoparietal regions after the negative cues compared with the positive and neutral cues, as well as higher theta phase synchronization within the prefrontal region, demonstrating negative cues rely more heavily on proactive control compared with other cue types. To examine reactive control, we measured EEG after the search onset. We found a lateralization of posterior alpha power toward the target side in both positive and negative cues conditions, with a later lateralization observed after negative cues. Interestingly, we observed a significant relationship between the increase of proactive theta power after negative cues and the decrease of reactive alpha power after the search. This suggests the coordination of proactive and reactive mechanisms lead to the most efficient search.

Genetic characterization of infectious spleen and kidney necrosis virus in Banggai cardinalfish Pterapogon kauderni identified from eight separate cases between 2000 and 2017

The authors declare that there are no conflicts of interest associated with this publication. The data that support the findings of this study are openly available in National Center for Biotechnology Information at https://www.ncbi.nlm.nih.gov/, reference number MN432490, MT926123. Figure S1 Histologic appearance of a typical infected Banggai cardinalfish from the BCIV-2010 case. (a) and (b) Spleen: Basophilic inclusion bodies in megalocytic cells whose morphology is often obscured. Foci of necrosis within intervening pulp areas. (c) and (d) Kidney: Basophilic inclusion bodies in megalocytic cells within foci of interstitial haematopoietic necrosis. (e) and (f) Intestine: Basophilic inclusion bodies in megalocytic perivascular cells but minimal mucosal reaction. Pigmentation within normal limits. Original magnifications: (a, c) 100×, (d, e) 200×, (b, f) 400×; H&E stain. Figure S2 Conventional PCR results of the Banggai cardinalfish case from 2000 (BCIV-2000) using the MCV-F/R primers (Koda et al., 2018) and a 100 bp ladder. (a) a single positive band for BCIV-2000 at the 173 bp position. Samples (b) and (c) are negative and correspond to the extraction control and negative template control, respectively. (d) a single bright band at the 173 bp position, representing the positive control for the MCV assay. Table S1 Genome annotation of the Banggai cardinalfish iridovirus from 2012 (BCIV-2012). Table S2 Genome annotation of the Banggai cardinalfish iridovirus from 2017 (BCIV-2017). Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Biomimetic PMMA coating surface and its application on inhibition of bacterial attachment and anti-biofilm performance

In this study, poly(methyl methacrylate) (PMMA) coating with biomimetic hydrophobic surface was fabricated through the nano-casting technique to transfer the surface of natural Xanthosoma sagittifolium leaf (XSL) to polymer surface and apply it in the inhibition of bacterial attachment and the anti-biofilm performance.First, poly(dimethyl siloxane) (PDMS) was used as a negative template to transfer the pattern of natural XSL surface. Subsequently, the commercial PMMA powder was dissolved in toluene and then dropped onto the PDMS template, resulting in the successful pattern transfer of natural XSL surface in producing an artificial biomimetic PMMA coating surface. Next, the surface morphology of biomimetic coating, denoted by Bio-PMMA, was investigated by SEM, containing micron-sized papillae decorated with many nano-scaled creases. Compared with that of non-Bio-PMMA coating, the contact angle(CA) of Bio-PMMA coating was found to increase significantly (increased from 68°±0.8° to 121°±0.6°), reflecting an increase of 53°±0.8° in CA, indicating that the original hydrophilic surface of PMMA can be converted to a hydrophobic surface when replicating the XSL template.In the research of anti-biofilm applications on artificial biomimetic PMMA coating, three types of bacteria (i.e., Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) were observed to study short-term anti-bacterial attachment and conducted long-term anti-biofilm test via SEM. Crystal violet and a Microplate reader were used for bacterial qualitative and quantitative analysis, respectively. The results showed that Bio-PMMA coating surface with micro papillae and folded micro-nanostructures inhibited the growth of bacteria and effectively delayed the formation of biofilm, and the hydrophobicity of the surface also helped to prevent the adhesion of bacteria, thus inhibiting the adhesion of bacteria with good long-term anti-biofilm performance.

Template Synthesis and Characterization of Ni Nanostructures

Nanostructures of a typical ferromagnetic material, nickel are fabricated by electro-deposition (in a DC mode) within the pores of polycarbonate track etched membranes. The cylindrical pores with pore diameter 100 nm have been used for present study. Negative template method via two electrode potentiostatic arrangement in electrochemical cell has been used to synthesize the ordered array of one-dimensional Ni nanostructures. Deposition has been carried out at \(41\pm2\) degree, 1.6 V and so formed one dimensional nanostructure has been obtained at a Copper substrate. The elegant approach of template synthesis has advantage that shape and diameter of one-dimensional nanostructure can be varied as per the requirement, by using the templates of different pore shapes and diameters. Crystalline nature of one-dimensional Ni nanostructures is confirmed by X-ray spectroscopy using Rigaku X-ray diffractometer. I-V characteristics have also been drawn using Keithley source meter, in order to check out the variation in electrical conductivity from bulk to nanoscale.

Guidance of visual search by negative attentional templates depends on task demands.

Visual search for a target is faster when its features are known before the search display appears, but there is an ongoing discussion about whether knowledge of nontarget features has a similar effect. Stored target or nontarget features used to guide visual search are referred to as positive or negative attentional templates, respectively. We suggest that the inconsistent findings concerning negative attentional templates may arise from 2 methodological choices in past research. The activation of negative attentional templates was never directly assessed and the use of negative attentional templates by the participant was optional. We addressed these issues in the contingent capture paradigm, which provides a marker for the activation of attentional templates in conditions where attentional templates are optional or mandatory. If an attentional template for a color is activated, cuing effects are larger for spatial cues in a matching color than for spatial cues in a nonmatching color. The question is whether the activation of negative attentional templates results in a similar difference between matching and nonmatching colors. We found that negative attentional templates were not activated when the target could be located based on its saliency (singleton search) and the use of the negative attentional template was optional. In contrast, when the negative attentional template was necessary to locate the target (feature search), we found the expected difference between matching and nonmatching spatial cues. Thus, the activation of negative attentional templates depends on task demands. In contrast, positive attentional templates were activated irrespective of task demands. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

UV-cured electroactive polyurethane acrylate coatings with superhydrophobic surface structure of biomimetic peacock feather for anticorrosion application

In this work, UV-cured electroactive polyurethane acrylate (EPU) materials with the superhydrophobic surface structure of biomimetic peacock feather were firstly prepared and applied in anticorrosive coatings. Firstly, amine-capped aniline trimer (ACAT) and vinyl-capped aniline trimer (VCAT) were synthesised and characterised by 1H-nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FTIR) and mass spectroscopy. Polyurethane acrylate (PUA) was synthesised and characterised by 1H NMR and FTIR spectroscopy. EPU was then prepared through the UV curing of PUA with 0, 1, 3 and 5 wt% VCAT (named EPU0, EPU1, EPU3 and EPU5, respectively) and characterised via FTIR. The redox capabilities of the as-prepared EPU series were investigated by cyclic voltammetry studies. EPU with higher VCAT loading (EPU5) exhibited better corrosion protection performance than those with lower VCAT loadings (EPU0, EPU1 and EPU3) based on a series of electrochemical corrosion measurements because of the formation of a dense metal oxide layer as evidenced by Raman spectroscopy. Moreover, EPU5 with the surface structure of biomimetic peacock feather (denoted by BEPU5) was prepared by nanocasting technique with polydimethylsiloxane as the flexible transparent negative template. The surface morphology and wettability of BEPU5 was investigated by scanning electron microscopy and contact angle (CA) analysis. The CA of BEPU5 remarkably increased to 145° compared with that of EPU5 63°. This massive increase in CA indicates efficient superhydrophobic properties, which were induced by the biomimetic peacock feather and produced outstanding corrosion protection performance for short and long terms based on a series of electrochemical corrosion measurements. This study is the first of its type to produce a biomimetic feather with massive increase in superhydrophobic properties, which is expected to revolutionise biomimetic industrial coating technologies towards better corrosion protective coatings.

Natural Polymer-Based Micronanostructured Scaffolds for Bone Tissue Engineering.

Although bone tissue allografts and autografts aremoften used as a regenerative tissue during the bone healing, their availability, donor site morbidity, and immune response to grafted tissue are limiting factors their more common usage. Tissue engineered implants, such as acellular or cellular polymeric structures, can be an alternative solution. A variety of scaffold fabrication techniques including electrospinning, particulate leaching, particle sintering, and more recently 3D printing have been used to create scaffolds with interconnected pores and mechanical properties for tissue regeneration. Simply combining particle sintering and molecular self-assembly to create porous microstructures with imbued nanofibers to produce micronanostructures for tissue regeneration applications. Natural polymers like polysaccharides, proteins and peptides of plant or animal origin have gained significant attention due to their assured biocompatibility in tissue regeneration. However, majority of these polymers are water soluble and structures derived from them are in the form of hydrogels and require additional stabilization via cross-linking. For bone healing applications scaffolds are required to be strong, and support attachment, proliferation and differentiation of osteoprogenitors into osteoblasts. Our ongoing work utilizes plant polysaccharide cellulose derivatives and collagen to create mechanically stable and bioactive micronanostructured scaffold for bone tissue engineering. Scaffold microstructure is essentially solvent sintered cellulose acetate (CA) microspheres in the form of a negative template for trabecular bone with defined pore and mechanical properties. Collagen nanostructures are imbued into the 3D environment of CA scaffolds using collagen molecular self-assembly principles. The resultant CA-collagen micronanostructures provide the benefits of combined polymers and serve as an alternative material platform to many FDA approved polyesters. Our ongoing studies and published work confirm improved osteoprogenitor adhesion, proliferation, migration, differentiation, extracellular matrix (ECM) secretion in promoting bone healing. In this chapter we will provide a detailed protocol on the creation of micronanostructured CA-collagen scaffolds and their characterization for bone tissue engineering using human mesenchymal stem cells.

Abstract P169: Dynamic cell-level modeling of antibody binding and internalization for radiosensitivity assessements in alpha-emitter radiopharmaceutical therapy

Abstract The radiobiological response to alpha-emitter radiopharmaceutical therapy (αRPT) is often studied in cell monolayers. The geometric models which are currently used to estimate the relationship between isotope activity concentration and cell survival probability typically idealize cells as spheres without considering cellular biological processes. This results in inaccurate and non-generalizable results, which could hamper the rigorous study of the underlying radiobiology. The purpose of this study was to create accurate absorbed dose models by combining Monte Carlo simulations with 3D measurements of cell clustering and geometries, as well as dynamic carrier molecule binding and trafficking in individual cells of cell monolayers. This allows for a more accurate way to model cell survival in these αRPT experiments. Experimental conditions of previous cell survival experiments with 212Pb on NT2.5 HER2+ breast cancer cells were replicated. Live cells were imaged on a confocal microscope. Nuclei were stained with Hoechst and the media was stained with labelled dextran, creating a negative template of the cells. A relevant antibody (Ab) was tagged with AF488. 3D time lapses of membrane binding kinetics and internalization were recorded. Photobleaching was modelled and corrected for. All cells were segmented into nuclei, membrane and cytosol compartments using a purpose-build algorithm. The temporal antibody signals were used to fit pharmacokinetic models, which enabled interpolation and validation with experimental binding assays. The segmentations were used in a Monte Carlo code. S-values for every compartment and time frame were calculated using the Ab distribution directly, capturing the effect of Ab trafficking. Absorbed doses were calculated for each cell and were used to model previously obtained cell survival curves. Statistics were calculated for >100 cells. We observed a large range in absorbed doses (coefficient of variation 0.74). Absorbed doses to the nucleus per unit decay on the membrane, which are mainly determined by cellular geometries, agreed with the geometric model (error <6%). S-values for intercellular decays increased >50% over time, which corresponds to perinuclear trafficking of Abs. The dose contribution of neighboring cells was high (46% of total dose; 6x geometric model), highlighting the importance of cell clustering. Applying this to previous cell survival data yielded an estimated radiosensitivity kappa of 7.1 (geometric model: 2.8). Cell clustering has a larger, and cell geometry has a smaller impact than is assumed in current models. Perinuclear trafficking of internalized Ab positively impacts cell nucleus absorbed dose, which is typically ignored. Dose variability should be included in radiosensitivity modeling. We intend to use such rigorous and highly detailed, cell-level analyses to arrive at simplifications that are generalizable and whose accuracy is better understood. For example, based on our findings a better accounting of cell clustering would substantially improve geometric model calculations. Citation Format: Remco Bastiaannet, Ioanna Liatsou, Robert Hobbs, George Sgouros. Dynamic cell-level modeling of antibody binding and internalization for radiosensitivity assessements in alpha-emitter radiopharmaceutical therapy [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P169.

Drag reduction and antifouling properties of non-smooth surfaces modified with ZIF-67

Marine equipment and ships operating in complex environments face high drag consumption and severe surface fouling. Non-smooth biomimetic surfaces with specific microstructures work to reduce surface drag and inhibit fouling. In this work, the biological sharkskin shield scale structure was simplified by the idea of segmented independence to construct a bionic non-smooth surface. Single-crystal lithography was used to create a negative template of the silicon substrate. We created a non-smooth bionic structure on the flexible polydimethylsiloxane (PDMS) surface through die casting and molding. Additionally, the bionic non-smooth surface was modified by decorating zeolitic imidazolate framework-67 (ZIF-67) particles to modulate the antifouling properties. Based on tests performed on a self-designed and processed circulating water bath laboratory bench (CWBLB), results showed the non-smooth surface effectively reduced drag by 7.3% compared to that of smooth surface. The contact angle (CA) measurement and anti-bio-adhesion experiment on the surface showed that PDMS surface CAs increased from 109.78° to 140.71°, and Chlorella vulgaris attachment was decreased by 65.3%. The non-smooth bionic surface effectively reduces drag and antifouling, and the effectiveness of the antifouling can be significantly enhanced by augmenting and regulating the particle surface modification method. Our results provide a feasible solution for ship drag reduction and antifouling, which is critical for industrial applications and sustainable development. • A method for processing single-crystal lithography of non-smooth hydrophobic surfaces has been developed. • A circulating water bath laboratory bench was designed, which can be used to measure axial resistance. • The ZIF-67 particle-modified surface possesses excellent resistance reduction and anti-fouling effects.

Graphene-based PANI composite coatings with fine-controllable 3D hierarchical structures prepared from bio-inspired photo-/colloidal-lithography technique for flexible supercapacitor application

In this study, various bio-inspired micro-/nano-scaled cylindrical patterns were designed by controlling their width and interspacing over a silicon substrate by using 3D photo/colloidal lithography techniques. The surface morphology and cross-sectional images confirmed the exact fabrication of bio-inspired textures. The as-prepared bio-inspired surface textures were coated with polydimethylsiloxane as a soft negative template and then covered with polyaniline (PANI) to investigate the morphology effect in supercapacitor application. Results showed that the bio-inspired texture with micro-/nano-architectured surface of two different widths and interspacing of 5 µm and 500 nm provided the best PANI capacitance performance of 429 F/g amongst other single and non-patterned (plain) templates with capacitance performances of 364 and 316 F/g, respectively, at 5 mV/s. Moreover, reduced graphene oxide was successfully incorporated into PANI; characterised using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy; and investigated for supercapacitor performance by using the bio-inspired micro/nano-template. A synergistic performance of 614 F/g was observed at 1 A/g with excellent capacitive retention of 85% after 10,000 cycles. Efficient flexibility was also found over long-term cycling without defects in the performance. Thus, these novel bio-inspired electrodes could open the door for developing further portable bio-inspired electronic devices in the future.

Additive Manufacturing Assisted Solvent Casting of 3D Free-Standing Carbonaceous Hydrogels and Aerogels As Electrodes for Supercapacitors

In a quest for renewable and highly efficient energy storage devices, carbonaceous hydrogels obtained from biopolymers have received much attention owing to their multifunctional properties [1]. The ability to fine-tune the structures of these hydrogels and the prospects of fabricating 3D hydrogels-based carbon electrodes with highly porous and interconnected nanostructure is believed to provide efficient migration of electrolyte ions and electrons. Even though additive manufacturing (AM) of hydrogels with 3D structures could simplify the fabrication, the printability of each material varies greatly. Furthermore, the mechanical properties of hydrogels are often too weak to withstand the printing of structures with a certain height [2].Herein, we demonstrate a facile and versatile method for the fabrication of novel and highly porous 3D carbon aerogel electrodes from bio-hydrogels based on additive manufacturing assisted solvent casting process followed by freeze drying and pyrolysis. Firstly, the negative templates with the required resolution and geometry were 3D printed using high-resolution stereolithography (SLA) based AM technology to be used as master molds and the pattern were transferred to the biopolymeric hydrogels during ionic crosslinking induced self-assembly, leading to gelation. After completion of the gelling process, the casted hydrogel was removed from the master mold, washed with deionized water, frozen using solid carbon dioxide (dry ice) and lyophilized (freeze-dried) to preserve the structure. The lyophilized free-standing aerogels were then converted to free-standing 3D pyrolytic carbon aerogels in a high-temperature tubular furnace at 900°C under a nitrogen environment. Different characterization techniques such as FTIR, BET, SEM, Raman, XRD and XPS were employed to access the influence of the process parameters on the final microstructure of the 3D carbon aerogels. The as-prepared 3D free-standing carbon aerogel when used as a binder-free electrode showed outstanding charge storage capability and kinetics arising from interconnected 3D porous channels. The versatility of this approach was further verified by the successful preparation of novel multifunctional 3D free-standing carbon aerogel hybrids using GO, CNT and/or metal oxides and its application as a structured binder-free supercapacitor electrode with improved electrochemical performance.With the advantageous features of synergistically regulating the structure and composition, the proposed method combining AM and casting could be used as a versatile tool to develop structured bio-hydrogels, to be used as precursor material for constructing novel architectured free-standing carbon electrode materials with well-defined geometry and controlled pore size distribution. The final shape of carbon electrode depends on the 3D geometry of the additive manufactured negative template used for the replication during solvent casting. This technique would broaden the library of hydrogels materials that could be constructed freely in three-dimensions for the fabrication of structured and free-standing porous bio-carbon based electrodes for high-performance supercapacitor application.

Large-Size Honeycomb-Shaped and Iris-Like Liquid Crystal Elastomer Actuators

Large-Size Honeycomb-Shaped and Iris-Like Liquid Crystal Elastomer Actuators

Improved Accuracy of Amyloid PET Quantification with Adaptive Template-Based Anatomic Standardization.

Amyloid PET noninvasively visualizes amyloid-β accumulation in the brain. Visual binary reading is the standard method for interpreting amyloid PET, whereas objective quantitative evaluation is required in research and clinical trials. Anatomic standardization is important for quantitative analysis, and various standard templates are used for this purpose. To address the large differences in radioactivity distribution between amyloid-positive and amyloid-negative participants, an adaptive-template method has been proposed for the anatomic standardization of amyloid PET. In this study, we investigated the difference between the adaptive-template method and the single-template methods (use of a positive or a negative template) in amyloid PET quantitative evaluation, focusing on the accuracy in diagnosing Alzheimer's disease (AD). Methods: In total, 166 participants (58 healthy controls [HCs], 62 patients with mild cognitive impairment [MCI], and 46 patients with AD) who underwent 11C-Pittsburgh compound B (11C-PiB) PET through the Japanese Alzheimer's Disease Neuroimaging Initiative study were examined. For the anatomic standardization of11C-PiB PET images, we applied 3 methods: a positive-template-based method, a negative-template-based method, and an adaptive-template-based method. The positive template was created by averaging the PET images for 4 patients with AD and 7 patients with MCI. Conversely, the negative template was created by averaging the PET images for 8 HCs. In the adaptive-template-based method, either of the templates was used on the basis of the similarity (normalized cross-correlation [NCC]) between the individual standardized image and the corresponding template. An empiric PiB-prone region of interest was used to evaluate specific regions where amyloid-β accumulates. The reference region was the cerebellar cortex, and the evaluated regions were the posterior cingulate gyrus and precuneus and the frontal, lateral temporal, lateral parietal, and occipital lobes. The mean cortical SUV ratio (mcSUVR) was calculated for quantitative evaluation. Results: The NCCs of single-template-based methods (the positive template or negative template) showed a significant difference among the HC, MCI, and AD groups (P < 0.05), whereas the NCC of the adaptive-template-based method did not (P > 0.05). The mcSUVR exhibited significant differences among the HC, MCI, and AD groups with all methods (P < 0.05). The mcSUVR area under the curve by receiver operating characteristic analysis between the positive group (MCI and AD) and the HC group did not significantly differ among templates. With regard to diagnostic accuracy based on mcSUVR, the sensitivity of the negative-template-based and adaptive-template-based methods was superior to that of the positive-template-based method (P < 0.05); however, there was no significant difference in specificity between them. Conclusion: In quantitative evaluation of AD by amyloid PET, the adaptive-template-based anatomic standardization method had greater diagnostic accuracy than the single-template-based methods.

Specific Assay of Negative Strand Template to Quantify Intracellular Levels of Rhinovirus Double-Stranded RNA.

Human rhinovirus infections are a major trigger for acute exacerbations of lower airway diseases, including asthma and chronic obstructive pulmonary disease. Disease exacerbation is thought to be regulated via double-stranded RNA (dsRNA)-mediated signaling of proinflammatory and host defense responses in airway epithelial cells. Despite the central role of dsRNA in regulating host cell responses, no method for the quantitative assessment of dsRNA levels during HRV infections has been developed. Conventional RT-PCR for the negative strand template is not effective as self-priming results in apparent signals, even in the absence of primer during reverse transcription. To avoid these issues, we developed a selective assay for the negative strand template that uses a chimeric primer containing a 5′ non-viral sequence for reverse transcription and a primer using the non-viral sequence during subsequent PCR. We established that this assay avoided issues of self-priming and is strand specific, as it is unaffected even in the presence of a 1000-fold excess of positive strand. Assays in primary human airway epithelial cells showed that negative strand was detectable within 6 h of virus exposure and peaked at 18 h after virus exposure. The temporal pattern of negative strand induction mirrored that of genomic RNA but was always 1000-fold lower than positive strand, indicating that the negative strand levels regulate levels of dsRNA formation. This assay will permit relative quantification of dsRNA during studies of HRV regulation of epithelial cell function.