Experimental and simulation results reveal that this ultrahigh scaling-resistance is attributed to the combination of hBN’s atomically-smooth surface, in-plane atomic energy corrugation due to the polar boron-nitrogen bond, and the close match between its interatomic spacing and the size of water molecules. The latter two properties lead to strong polar interactions with water and hence the formation of a dense hydration layer, which strongly hinders the approach of mineral ions and crystals, decreasing both surface heterogeneous nucleation and crystal attachment.Formation of mineral scale on a material surface has profound impact on a wide range of natural processes as well as industrial applications. However, how specific material surface characteristics affect the mineral-surface interactions and subsequent mineral scale formation is not well understood. Here we report the superior resistance of hexagonal boron nitride ( Scale formation may have detrimental effects on the properties and functions of materials’ surfaces. Here the authors report the high scaling resistance of hexagonal boron nitride and relate it to the atomic level structure and interaction with water molecules. It is reported that economical loss due to mineral scaling in boilers, turbines, and heat exchangers accounts for 0.17–0.25% of the gross domestic product (GDP) in industrialized nations5. Understanding mineral scaling behavior is important for the development of next generation materials and technologies that address these critical challenges.Interfacial interactions play a fundamental role in many aqueous processes including adsorption, catalytic reaction, corrosion, filtration, and scale formation. In particular, scale formation, i.e., the development of mineral deposits on a material surface due to precipitation from the bulk solution and/or crystal formation initiated by surface nucleation, has great impacts on interfacial transfer of mass, heat, electrons, and light. It causes profound performance decline in numerous industrial processes, such as impaired heat transfer in heat exchangers and boilers, increased pressure drop in pipes, flow blockage in filtration membranes, corrosion damage of steam turbines, decreased conductivity and activity of electrodes, premature failure of heating and electrochemical components etc.6. Both processes are strongly influenced by material surface properties. Similar to deposition of other particles, material properties affect the attachment of mineral crystals via hydrophobic and electrostatic interactions. Surface-induced heterogeneous nucleation is a more thermodynamically favorable process, but it is poorly understood because it happens on very small time and length scales7. Few previous studies have investigated the different surface properties that influence surface-induced heterogeneous nucleation: roughness, charge, and hydrophobicity6. Surface roughness is directly related to the number of nucleation sites; it is generally recognized that mineral crystallization increases with surface roughness. However, findings on the impact of charge and surface hydrophobicity have been inconsistent. For example, some studies found that surface charge influenced the heterogeneous nucleation via electrostatic interactions or complexation reactions with the mineral ions8, while others reported similar nucleation rates on surfaces of different charges9. Contradictory results have also been reported on the role of surface hydrophobicity in mineral scaling. Hydrophilic coatings such as graphene oxide (GO), graft polymers, and polyethylene glycol, were shown to delay the onset of CaCO3 scaling in some studies12, while other studies showed that hydrophilic surfaces promoted CaCO3 nucleation8, and GO had no anti-scaling effect13. One possible reason for such apparent contradiction is that modification of a surface property  often leads to inevitable changes in other surface properties, which makes it difficult to discern the role of an individual surface property for development of anti-scaling materials.Scale formation can occur through the deposition of mineral crystals formed in the bulk solution, as well as through surface-induced heterogeneous nucleation with crystals growing from nucleation sites on a surface14 and metal oxides15 in nonaqueous phases. Theoretical and experimental research on water-surface interactions21 and related phenomena, such as ultrafast water transport26, de-icing27, and anti-fouling28, also suggest that the atomically smooth morphology plays an important role in preventing adhesion. However, no studies have investigated the scaling behavior, especially heterogeneous nucleation, on the surface of 2D nanomaterials such as graphene and hexagonal boron nitride (hBN) in aqueous solutions. Furthermore, 2D materials vary widely in surface chemistry despite their common feature of atomic-level smoothness: Graphene consists of a single layer of carbon atoms arranged in a honeycomb lattice nanostructure, featuring a small lattice constant, low in-plane polarity, and high hydrophobicity; hBN, another important 2D material with its lattice structure and lattice constant similar to those of graphene30, has high in-plane polarity due to the boron-nitrogen bond and higher hydrophilicity than graphene18. It is unknown how such differences in surface chemistry influence mineral scale formation on these atomically smooth surfaces.Two dimensional (2D) materials possess atomically smooth surfaces, and have attracted tremendous interest for their potential applications in processes where interfacial interactions play a critical role. For example, graphene was shown to effectively inhibit nucleation of metalshBN surface, and compare it to that on metal ) and polymer ) surfaces commonly used for high scaling potential applications  of 3.28) and characterized using a video camera for 220 min  is much shorter than the operation time, both bulk precipitation due to homogeneous nucleation and surface induced heterogeneous nucleation contribute to scale formation. As shown in Fig. 4 crystals were found on the pristine Cu surface after 20 min, and severe scale formation (0.123 ± 0.014 mg mm−2) was observed after 220 min of testing. On the graphene surface, CaSO4 crystals occurred after 40 min, and increased to 0.015 ± 0.008 mg mm−2 at the end of the experiment  during the 220 min experiment, except at its edges where the hBN nanocoating was damaged due to sample cutting  two orders of magnitude lower than CaSO4 (19.10 mmol L−1). It allows using much lower concentration to prepare supersaturated CaCO3 solution with saturation index similar to supersaturated CaSO4, which would generate smaller amount of scalants on the surfaces and is conducive to performing microscopic ex situ or in situ characterizations. As shown in Fig. 3 (SI of 1.18) was introduced to the test surfaces immediately after preparation before homogeneous nucleation occurred , while 55.6 ± 3.3, 13.2 ± 4.7, and 3.6 ± 0.8 vaterite crystals mm−2 were found on Ti, PVDF, and graphene surfaces, respectively  technique  led to an immediate albeit small change in frequency and dissipation, which reached equilibrium in ~1 h. The larger frequency and dissipation changes observed for the Ti and PVDF surfaces suggested more adsorption of Ca2+ and CO32− ions than that on the graphene and hBN surfaces. The similar frequency and dissipation changes on graphene and hBN surface suggested that they had similar ion adsorption, a result of their similar surface charge32. After the initial ion adsorption, greater frequency and dissipation changes occurred, and exhibited two distinct stages. The first stage (stage i) featured relatively slow changes in frequency (dF/dt) and dissipation (dD/dt), signaling the formation of vaterite nuclei, i.e., the induction process. This was followed by a much faster frequency shift (stage ii), which signaled crystal growth from the nuclei previously formed on the surface , which are atomically smooth with no observable sags, crests, or other surface irregularities. During the nucleation and crystal growth stages, the nanoscale rough features on Ti and PVDF serve as heterogeneous nucleation sites, provide cratered surface for nuclei attachment, and increases friction that may hinder local flow velocity33, all conducive to vaterite nucleation and crystal growth, resulting in a shorter induction stage and faster vaterite growth  > PVDF (27.6 ± 3.4 μN μm−2) > hBN (12.1 ± 4.3 μN μm−2) ≈ graphene (11.1 ± 6.1 μN μm−2), correlating well with the surface roughness  and moderate carbon atom electronegativity (2.55)  is therefore notably higher than B (2.04), leading to corrugated charge distribution on hBN surface with a dipole moment of 0.047 D  Fig. . In hBN,7 D Fig. . The highBN surface has an important influence on its interaction with polar water molecules. The alternating negative and positive charge regions on hBN attract H and O atoms in water, respectively, leading to stronger interaction with water molecules than on graphene surface, where the charge is more uniform. As a result, water molecules are more closely packed and located closer to the hBN surface: the average distance between water molecules is 2.45 Å, and the closest distance between water molecule and the hBN surface is around 2.92 Å  is required for a Ca2+ ion to penetrate the hydration layer to reach the hBN surface than the graphene surface  is smaller on hBN than on graphene  are smaller than those reported for conventional material surfaces, such as NaCl(001) (~3.0 Å51), Cu(110) (2.8 ± 0.2 Å52), and Au(111) (2.71–2.88 Å53), as well as the calculated intermolecular distance between water molecules in bulk water (2.81 Å). The denser interfacial water layer formed on the 2D ultra-smooth graphene and hBN surfaces may be related to their small atom size and lattice constant that closely matches the size of water molecule. Most conventional materials have lattice constants larger than 3.0 Å (Supplementary Table hBN (2.50 Å) match the water molecule size better, with hBN’s lattice constant being the closest to a water molecule size. The close match between the distribution of hBN surface energy corrugation (charge nonuniformity) and the di-pole of water molecules leads to strong polar interactions between the hBN surface and polar water molecules, and hence compact packing of water molecules on hBN surface. Combining an atomically smooth surface, large in-plane polarity, and a lattice constant matching best with the size of water molecules  pipes using the chemical vapor deposition (CVD) method . These coatings can protect substrate materials from scaling or corrosion62, as well as ensure energetically efficient fluid flow, high heat transfer rate, and long material lifetime.Overall, the unprecedented scaling resistance of hBN possibly the most anti-scaling material known, with notable advantages over graphene. The atomic smoothness of both hBN and graphene surfaces reduces the number of surface heterogeneous nucleation sites as well as the binding force between the mineral crystal and the surface, resulting in much greater resistance to mineral scaling compared to conventional scale-resistant materials. Interestingly, hBN exhibits even greater resistance to surface-induced heterogeneous nucleation than graphene, which stems from the in-plane dipole of the boron-nitrogen bond at a scale closely matching that of water molecules, leading to in-plane atomic energy corrugation that favors interaction with water. Direct experimental measurements and DFT calculations show that such chemical structure results in the formation of a dense hydration layer on the hBN surface, which strongly hinders mineral ions from approaching the surface and hence suppresses the heterogenous nucleation process. The hBN nanocoating grown on a stainless-steel tube exhibits outstanding anti-scaling properties in real oil & gas produced water, demonstrating its potential application in practical engineering systems. The results of the study provide important insights for future development of novel functional materials by manipulating their interactions with surrounding media. On the other hand, the scalability, durability, and long-term scaling resistance of the hBN coating as well as the specific roles of substrate materials and defects in large scale coatings need to be evaluated before practical applications can be possible.In summary, we discover that the unique combination of atomically smooth surface, high in-plane polarity, and proper interatomic spacing (lattice constant) makes hBN coatings were formed on Cu foil . Before coating, the Cu substrate was electrochemically polished. Ti films of 40 nm in thickness were formed on the Cu substrate using a sputter coater  at a current of 30 mA. PVDF was coated on the Cu substrate via spin coating. A 1wt % PVDF in DMF solution was applied at a rotation speed of 2000 rpm for 1 min, followed by overnight drying at 60 °C before use.Ti, PVDF, graphene and hBN films were formed on Cu substrate by chemical vapor deposition (CVD). During growth, the electrochemically polished Cu foil was first loaded into a tube furnace and heated to 1000 °C, followed by annealing at 1 Torr 15% H2/Ar for 20 min. The graphene growth was then carried out by feeding 15% H2/Ar (flow rate of 100 sccm) and methane (flow rate of 10 sccm) to the furnace for 20 min. For hBN growth, ammonia borane was used as the precursor. After Cu foil annealing, ammonia borane was heated to ~85 °C for evaporation upstream of the tube furnace, and was carried by H2 gas to the Cu substrate to grow hBN at 1000 °C for 30 min. After growth with graphene or hBN, the Cu foil was rapidly cooled down to room temperature for further use.Graphene and hBN were characterized by Raman spectroscopy  and X-ray photoelectron spectroscopy (XPS)   and atomic force microscopy (AFM) . The chemical property of the graphene and hBN nanocoatings were formed on flat Cu substrates, and their scaling resistance was evaluated in a solution supersaturated with CaSO4, a common scalant in ground water that was very difficult to remove. The supersaturated CaSO4 solution (50 mmol L−1) was prepared by mixing 100 mmol L−1 CaCl2 with 100 mmol L−1 Na2SO4 at a 1:1 volume ratio. The prepared solution had a pH of 7.0 and a saturation index (SI) of 3.28. SI is defined as the ratio between the chemical activity product of the mineral ions and their solubility product63. During the experiments, the pristine Cu foil, hBN- and graphene- grown Cu foils were immersed in the CaSO4 solution. Scale formation was monitored using a video camera for 220 min : Ca2+ and CO32− activity are 1.23 × 10−4 and 1.24 × 10−4 mol L−1, respectively; pH is 8.84, ionic strength is 5.56 × 10−3, and calcite, aragonite, and vaterite saturation indexes ({Ca2+}{CO32−}/Ksp) are 4.45, 3.18, and 1.18 respectively. The induction time for homogeneous nucleation was determined by dynamic light scattering (DLS) measurements using a NanoBrook Omni    technique , which has a mass sensitivity and a dissipation sensitivity of 1.8 ng cm−2 and 0.1 × 10−6 in liquid, respectively64. To perform the QCMD experiments, the four test materials were first coated on QCMD sensors. Ti and PVDF were coated on QCMD sensors using the same methods as those used for coating the Cu substrate. Graphene and hBN were first grown on Cu substrate, and then transferred onto QCMD sensors using a PMMA-assisted method. In this method, a PMMA film was spin-coated on the graphene- or hBN- grown on the Cu foil. The sample was then immersed in a FeCl3 solution to dissolve the Cu substrate. The graphene or hBN layer immobilized on the PMMA film was then transferred to DI water, and subsequently collected onto the QCMD sensor surface with the graphene or hBN side attaching to the sensor surface. Finally, acetone and IPA were used to dissolve the PMMA layer, exposing the graphene or hBN surface. The coated sensors were then mounted in 4 parallel QCMD cells, and characterized for CaCO3 nucleation and growth at a temperature of 22 °C using the same supersaturated solution and flow rates as the offline scaling experiments described above. The frequency and dissipation data were continuously monitored for each coated sensor.The heterogeneous nucleation and crystal formation of CaCO−2) on the sensors was calculated from the frequency change using the Sauerbrey equation:−2 Hz−1 in this study. Δf is the frequency change (Hz). n is the harmonic number.The increase of adsorbed or precipitated mass  the interaction between water molecules and hBN or graphene surface, (iii) the interaction of Ca2+, CO32−, and CaCO3 with bare hBN and graphene, and (iv) the interaction between Ca2+, CO32−, and CaCO3 and hydrated hBN or graphene. Detailed calculation and simulation methods can be found in the Supplementary Note In this study, we used density function theory (DFT) to evaluate (i) the charge distribution on graphene and hBN surfaces utilizing N2/H2O mixed gas at different humidity levels. In these experiments, a customized humidity control device was installed between a N2 gas tank and the QCMD analyzer  concentration of 108 mg L−1 and conductivity of 148 mS cm−1. Detailed water quality data are shown in Supplementary Table 2 or Na2SO4 to prepare the respective Ca2+- or SO42−- rich solutions. During the experiment, the two solutions were continuously fed into an inline mixer at 0.1 mL min−1 and then flowed through the pristine and hBN coated SS tubes at a combined flow rate of 0.2 mL min−1. Scale formation was monitored using a camera during 14 days of operation.We also grew a Supplementary InformationPeer Review FileSupplementary Movie 1Supplementary Movie 2Supplementary Movie 3


To help advance exchanges between science and policy, a useful first step is to examine the questions which policymakers pose to scientists. The style of a question indicates what the asker is motivated to know, and how they might use that knowledge. Therefore, the aggregate pattern of typical policy inquires can help scientists anticipate what types of information policy audiences desire. A dataset (n = 2972) of questions from policymakers collected over 10 years (2011–2021)—by the Centre for Science and Policy at the University of Cambridge—was classified into one of seven classes. In the main, the most popular questions posed by policymakers—within the public and private sectors—were those whose answers inform how to achieve specific outcomes—whether directly, or by providing a causal analysis which is instrumental to this process. Moreover, this seems to be a general aspect of policymakers’ inquiries, given that it is preserved regardless of the policy issue considered . Thus, maximizing the usefulness of the information that policymakers receive when engaging with scientists requires informing how to achieve specific outcomes—directly, or by providing a useful causal analysis. Several studies have highlighted barriers to effective translation from scientific evidence to policy3. In particular, scientists and policymakers often have different motivations and goals, which limit their collaboration4. Whilst the prospects for bringing these two communities’ motivations and goals into complete alignment are poor, scientists might reasonably gain a greater understanding of the motivations and goals of policymakers—and how the evidence they generate feeds into, or helps to achieve, them. Examining the questions which policymakers pose to scientists is instrumental to achieving this greater understanding. The ‘style’ of a question—the structure of the information sought (see below)—provides valuable indicators of what the asker is motivated to know, and what they might use that knowledge for6. Indeed, science-policy exchanges can often involve framing policy issues through a particular style of inquiry that articulates policymakers’ goals and the means of achieving them7. In light of this, the aim of this study is to examine the styles—and subject matters—of questions which policymakers pose to scientists, in order to expose any underlying patterns in these evidence requests. An understanding of these underlying patterns can potentially aid the integration of scientific evidence into policymaking through co-production8. Co-production requires a mutual understanding between scientists and policymakers9, which, in turn, requires clarity regarding any subject matter under discussion and the structure of the information sought. Furthermore, the integration of scientific evidence into policymaking is aided by tailoring evidence to the structure of the information sought by policymakers. To this end, the discussion will contain some advice for evidence tailoring.Knowledge exchange activities between science and policy are driven by a need to address practical issues5 uses the term ‘content’ to refer solely to the subject matter that a question/answer concerns. By contrast—as noted by Pomerantz5—Graesser, McMahen, and Johnson10 use the term ‘content’ to refer both to a question’s subject matter and its style. When using antecedent studies to evidence the arguments in this paper, such terminological issues are disregarded in favour of the underlying point being made.Before considering the substantive lessons to be drawn from the literature on questions, a terminological confusion must be addressed. Within this domain, a universal agreement regarding the meanings of certain relevant terms has not yet been reached. This might cause confusion, as the same term can be deployed to refer to distinct features of questions and/or answers. For example, Pomerantz5. For example, sincerely asking “what is net zero?” implies that one wants to know about the net-zero emissions goal. The style of a question—the structure of the information sought—indicates the understanding of the inquirer11, and what kind of answer is expected13. Asking a sincere question implies that the inquirer has enough of an understanding of the issue from which to build the question and interpret the answer, but does not know enough to make seeking the answer superfluous11. For instance, sincerely asking “what is net-zero?” requires that the inquirer has at least heard of the term ‘net-zero’ but does not have a complete understanding of its referent. Furthermore, the style of this question indicates that sincere answers should be structured as definitions. By contrast, sincerely asking “what do we need to do to achieve net-zero?” requires that the inquirer has a basic understanding of what net-zero is but not a complete understanding of how to bring it about. Moreover, the style of this question indicates that sincere answers should outline the procedure(s) which will bring about net-zero.To begin, it is useful to consider two contrasting features of questions: subject matter and style. The subject matter of a sincere question indicates the information that the inquirer is interested in attaining, thereby indicating the kind of content which would be appropriate for a sincere answer15, linguistics14, and information science5 provided the foundation for the types of analyzes that have been used to develop taxonomies of questions. Importantly, question stems—such as “why…?”, “how…?”, “when…?”, and “what…?”—have not been the standard basis on which taxonomies are developed, because they are typically polysemous17. The ambiguity of question stems makes their application highly context-specific, hence why question classification systems have generally focused on question styles12.Earlier work in psychology13 was the originator of this approach. Graesser, Person, and Huber12 later generated a simpler taxonomy of questions by style (the ‘Taxonomy of Question Styles’)—these questions were later grouped by the length of the expected answer by Graesser, McMahen, and Johnson10  to analytical questions—such as causal consequence-style questions (“why did X occur?”)—to develop deeper understanding.Through an analysis of the frequency of questions generated, this taxonomy has been used to determine what types of questions are most likely to appear in a particular domain. Such information feeds into proposals regarding what improvements are necessary to support an effective evidence exchange process. In the education domain—where the Taxonomy of Question Styles has been used most often—it has aided in identifying the types of inquires made by students, so that they can then be encouraged to formulate different styles of questions which enable a more substantive understanding of a topic12. It proposes that there are three dimensions on which a question should be assessed. Firstly, style (“content”): the structure of the information sought. Secondly, question-generation mechanism: the psychological processes—goals, plans, and knowledge—which bring about a question. The GPH Scheme lists four question-generation mechanisms: reducing, or correcting, a knowledge deficit; monitoring common ground; social coordination of action; and control of conversation and attention. The scheme holds that these categories are orthogonal to the style categories, since—in theory—a style of question might be motivated by any question-generation mechanism. For example, an inquirer might ask “what are the consequences of academic freedom?” to address a deficit in their knowledge. Alternatively, the same question might be asked to monitor the extent to which they share common ground with the responder. The GPH Scheme’s final dimension of assessment is ‘degree of specification’: the extent to which the information sought is made clear. A highly specific question is clear regarding what information is sought. Whereas an under-specified question requires the responder to make inferences about which details are relevant to the inquirer.The theoretical underpinning of work analyzing the quality of questions has largely been informed by the ‘Grasser-Person-Huber (GPH) Scheme’32. Within social psychology, improvement in ability regarding interpersonal exchanges has also been shown to be the result of asking good questions33, that can increase one’s likability35. Many of the efforts to improve cognitive functions , by improving questioning, are based on two factors. Firstly, increasing the specificity of the question to ensure that the responder has the best chance of providing answers that are directly applicable. Secondly, encouraging ‘deep-reasoning questions’: those which direct the inquirer to ask questions that invite a causal analysis6. In essence, this involves considering the cause-effect relationships between variables to start examining the underlying structures that enable inferences to be made about what brings about observable outcomes37.Within cognitive psychology, associations have been made between the effective generation of questions and problem-solving ability, as well as the learning of complex materialTo date, there has been no empirical work examining the styles of questions that policymakers pose to scientific experts—including the types of questions that are asked, and the frequency by which they are asked. Once this is understood, it can be used to improve science-policy exchanges. Improvements can be made to the articulation of policy questions so that the value of the answers provided is maximized. Furthermore, scientists might find it easier to adapt their communication, in order to focus on the evidence that policy audiences want from them. To address this deficit, the present study analyzed policy questions that have been compiled by the Centre for Science and Policy (CSaP), at the University of Cambridge. CSaP is a knowledge brokerage which creates opportunities for public policymakers and academics—primarily scientists—to learn from each other. This is achieved through CSaP’s Policy Fellowships, as well as workshops, seminars, conferences, and professional development activities.Applicants to CSaP’s main ‘Policy Fellowship Programme’ initially submit 3–6 questions which indicate the main policy problems they will explore throughout their Fellowship—along with a justification of their influence on public policy and their aims and objectives concerning the Fellowship. A panel of academics and civil servants review the applications and assess the candidates regarding how influential their role is, their intellectual capacity (to get the most out of 25 one-hour meetings with academics throughout the Fellowship), the extent to which their questions will interest academics, and the relevance of the contributions that might stem from addressing their questions. During an initial meeting with successful applicants, Fellows are provided with any feedback from the judging panel, including any suggested changes to their proposed questions. The Fellows are then asked to submit their finalized questions—if different from those submitted in their applications. Fellows spend five days in Cambridge for one-to-one meetings with academics. In general, Fellows visit Cambridge twice for this purpose, submitting 4–5 questions per trip (though sometimes the same questions are submitted for both trips). As a result of this process, CSaP has accumulated a database of policy questions submitted by over 400 Policy Fellows over 10 years.The database was used to examine two properties of policy questions: (1) what frequent styles of questions are posed to expert scientists? (2) Is there a relationship between the subject matter and style of questions posed to expert scientists? By answering these questions, it is possible to build up a profile of what evidence policymakers invite scientific experts to provide, as well as what that evidence is applied to.At the time the analysis of the questions was conducted there were a total 4319 questions for the period of 05–09–2011 to 23–09–2021. These were generated from a total of 443 different Policy Fellowships taken up at CSAP. The questions were then cleaned. In particular, this involved removing statements and duplicate questions (posed by the same Policy Fellow over consecutive trips to Cambridge). Once this filtering had been applied, there were a total of 2927 questions from 409 Policy Fellows that were submitted for analysis. Each question contained the following details: (1) a unique number to identify it (1–2927), (2) whether the Policy Fellow was from a public or private sector organization , (3) the year that the question was submitted, and (4) the word length of the question.38. First, the Taxonomy of Question Styles was applied to all 2972 questions. This initial attempt to classify the policy questions served two purposes: to identify categories that are applicable to policy questions from the original taxonomy, and to identify new categories where needed. From this, a second taxonomy was developed, which included categories from the Taxonomy of Question Styles as well as some new ones.To ensure an appropriate classification system was applied to the questions, the questions were classified using an iterative approachThe development of this revised taxonomy started from the principle that the question style categories deployed in a policy-specific taxonomy need to be useful to policymakers. This was inferred from each question style’s frequency in the coding of the questions. As shown in Table 39: categories should not be inflated beyond necessity. When taking this into account, along with the related point that some of the categories were broad enough to significantly span the specification of others, the next step was to determine how many of the questions coded revealed matches based on feasible overlaps. This identified an addition 331 matches between coders, which increased the total level of agreement to 74.59%. Categories with superficial differences were merged to achieve mutual exclusivity. The resulting ‘Taxonomy of Policy Questions’ . Trends in subjects over time were not analyzed because the policy interests/positions of the Fellows are not controlled for. Consequently, some years the data is skewed towards different subjects by virtue of the interests/positions of the Fellows at the time.The aim of the content analysis was to examine whether certain subjects lent themselves to particular question styles. This involved looking at the domains of the organizations to which the Policy Fellows belonged, to narrow down the subjects that informed the content analysis. There were seven common types of policy subject: Artificial Intelligence (AI), Economics and Finance, Education, Environment, Defense and Security, Health, and Technology/Manufacturing. From this, several associated topics were identifiedA general point concerning the statistical analysis of the dataset was that—due to the nature of the dataset—the analyzes were ran to gather a general impression of the pattern of findings rather than to develop firm conclusions. Inferential statistics were used with caution, given that in many cases the data violated basic assumptions for running the test (e.g. independence).χ2  = 10.16, p = 0.12, Cramer’s V = 0.06. Given this, for the remainder of the analyzes performed, we collapsed across the two groups of policymakers. Generally, there were more questions that invited unbounded answers (76%) than bounded (24%), χ2  = 890.96, p < 0.001. Running a further analysis indicated there were significant differences in the distribution of questions by the seven sub-ordinate categories, χ2  = 110.54, p < 0.001, where the most frequently generated type of question was instrumental/procedural  or public sector (80%) organizations, a simple analysis indicated that there is no significant difference between the two groups by frequency of class of questions, M = 22.53, SD = 15.66) questions are longer than unbounded questions , t (2925) = 3.68, p < 0.001, d = 0.15, BF = 0.05, but the effect sizes and Bayes factor indicate that this is a weak difference. Looking at the average word counts for each of the seven classes of questions, example/explaining class of questions seems to be the outlier . Applying the Bonferroni correction, when compared against the other unbounded answer types, the phrasing of example/explaining questions were significantly shorted than causal analysis questions, t (975) = 8.27, p < 0.005, d = 0.53, BF13 = 1.11, instrumental/procedural, t (1371) = 11.27, p < 0.005, d = 0.65, BF25 = 1.23, and explaining/asserting value judgments, t (753) = 9.08, p < 0.005, d = 0.67, BF16 = 2.41, verification/qualification, t (877) = 8.67, p < 0.005, d = 0.58, BF15 = 5.16, forecasting, t (595) = 6.15, p < 0.005, d = 0.57, BFz = 1.94, comparison, t (535) = 6.04, p < 0.005, d = 0.67, BF7 = 3.45. Overall, the word length of the question doesn’t appear to be indicative of the types of answers it invites.Bounded . Given that a question could contain multiple subjects, when taking this into account , the most commonly occurring subjects—occurring once in each question—were AI  and Technology/Manufacturing . A total of 595 questions had a combination of two subjects present, with the most common pairing being Environment and Economy/Finance . A total of 193 questions had three subjects in combination, with the most common triple being AI, Environment, and Economy/Finance . A total of 42 questions had four subjects in combination, with the most common quadruplet being AI, Technology/Manufacturing, Environment, and Economy/Finance . A total of four questions contained five subjects and one question contained six subjects. None contained all seven subjects.38. Classifying the questions by subject and by style on these two sets provided a basis for determining consistency in any patterns detected. Looking across both classification methods, the most common question-style for all seven main subjects, was instrumental/procedural questions (average 34%). This may not be a surprise given the base rate of this class of question. Where subjects differed was the second most common question class that they appeared in. When classifying all questions coded by subject, the second most common question class for six of the subjects was causal analysis (average 20%), with the exception of AI which was verification/qualification (16.67%). When classifying questions coded by subject appearing only once in a question, then the second most common class was causal analysis (average 21%) for AI, Environment, and Defence/Security. For Economics/Finance, Education, and Technology/Manufacturing the second most common class of question was example/explanation (average 19%), and for Health the second most common class of question was verification/qualification (23.14%). Overall, the indication from the examination of content by question class is that all seven subjects most commonly appeared in instrumental/procedural questions, thereafter the subjects appeared commonly in other unbounded questions-styles  with few appearing commonly in bounded question-styles .The next way in which the content of the questions was examined was how often the various question styles appeared within the set of questions for each subject. Since multiple subjects sometimes appeared within the same question, independence was violated, which prevented any categorical inferential analyzes. Nonetheless, it was possible to determine an overall impression of the most common class of questions which different subjects appeared in. All questions were classified (n = 1786) that were coded by subject into the seven different classes of questions, and this was then repeated for questions where the subject appeared only once in each question (n = 951)From a database of 2927 policy questions, that were classified according to a taxonomy that has its roots in research on the psychology of questions, we find that: (1) the two most frequent question-styles invite answers that address causal-analytic and instrumental/procedural matters; (2) regardless of the policy subject, the most common answer that policymakers invited informed instrumental/procedural questions. This indicates that the common questions that policymakers present in exchanges with scientists are deep-reasoning based questions, that aren’t just for reducing or correcting knowledge deficits, but for presenting knowledge for specific purposes—such as informing what policy interventions could be taken.This has clear prescriptive implications for scientists who wish to participate in the co-production of policy—and specifically the integration of scientific evidence into policymaking. By tailoring their evidence to these most common policy question styles, scientists might reasonably hope to maximize their chances of success. The abstract specifications of these styles can be used for this purpose. For example, scientists might ask themselves: is there an obvious policy goal that this research might help to achieve? However, it might be necessary to update evidence tailoring to meet the specific interests of any policymakers they engage with.37. This aligns closely with work in cognitive psychology that examines causal reasoning, which has shown consistent improvement in the way a causal-analytic representation can impact decision-making41, problem solving43, moral reasoning45, perception47, interpretation of statistical information49, and evidential reasoning51. Recently, the application of causal-analytic approaches has been extended to policymaking56. This work suggests that, in order to interpret the effects of a policy intervention, what is first needed is to decompose the context in which the intervention is introduced into its causal factors (i.e. the variables that will support as well as inhibit the efficacy of the intervention). Achieving this requires formulating questions that concern the mechanisms which can bring about change in a desired direction and what outcomes need to be measured to determine the causal link between the intervention and the outcome. Thus, there is a clear relationship between causal analysis and instrumental/procedural/enablement reasoning: the former is a means to the latter. Scientists wishing to engage with policymakers might keep this framework for interpreting the effects of a policy intervention in mind.The fact that the two most frequently generated classes of questions were causal-analytic (e.g. understanding mechanisms) and instrumental/procedural (e.g. interventions) reveals important information regarding the main motivations and interests of policymakers. Inviting answers that expose cause-effect relationships between variables is also key to examining the underlying structures that enable inferences to be made about what brings about observable outcomesAs the results show, policymakers do invite answers that are causal-analytic in nature, but they are half as popular as questions which invite answers that inform how to achieve specific outcomes . This finding can be contextualized in light of the relationship between causal analysis and procedural reasoning: the most popular questions posed by policymakers—within the public and private sectors—were those whose answers inform how to achieve specific outcomes—whether directly, or by providing a causal analysis which is instrumental to this process. Given the importance of causal analysis in determining the potential success of policy interventions, scientists might consider framing their answers via causal-analytic terms. Furthermore, depending on the reception to their instrumental/procedural questions, policymakers may consider increasing the number of causal analysis-style questions they ask.58. Both characterizations allow some role for policymakers’ preference for instrumental/procedural questions. The result also provides some backing for the claim that the scientific and policy communities are divided. In its weaker form, this simply amounts to the claim that scientists and policymakers have different goals and motivations4. In its stronger form, it amounts to the claim that scientists and policymakers constitute two distinct communities that are poorly connected, motivated by different incentives, operate under different rules, and suffer from communication problems59. In either form, this claim might explain the poor fit between researchers’ assembling and packaging of information and policymakers’ practical needs60. However, the stronger claim (the ‘two communities’ theory) has faced robust criticism. In particular, it is hard to provide a specific characterization of the theory’s titular communities which is consistent with the data62. Thus, perhaps this result might be more fruitfully associated with the weaker claim, as part of a nuanced account of science-policy interaction. Finally, as the previous paragraph indicates, this result could be of use in the policy studies project of developing ‘bridging instruments’: tools which help to bring academics and policymakers closer together61.Policymakers’ preference for asking instrumental/procedural questions is also relevant to several of the academic literatures on policymaking. It is consistent with several characterizations of ‘evidence-based policy’. This concept has been characterized in a strictly means-end way and, more broadly, as the complex interaction of evidence and individual, professional, and political goals6, interviewing28, and health inquiries26. Thus, the fact that more unbounded than bounded question-styles were generated may reflect the properties of the domain in which the questions were asked—the policy domain—rather than the taxonomic structure used to classify the questions. In the main, policymakers tended to ask questions directed towards detailed answers. Often this meant steering away from constraining answers to provide an estimate about a future outcome (forecasting), verifying a particular understanding of an issue , or outlining the strengths/weaknesses costs/benefits of a particular issue (comparison). The lesson for scientists wishing to participate in the co-production of policy is that less constrained answers—regarding forecasting, verification/qualification, and/or comparisons—might be required to address policymakers’ needs.Other insights from the analysis of the questions suggest that more unbounded  questions were generated than bounded  questions. Given that there were fewer classes of bounded question-styles to unbounded question-styles, one might think it inevitable that fewer bounded questions would be identified. However, previous work provides evidence which suggests that, independent of the number of categories of questions corresponding to short vs. long answer types—depending on the domain—more short answer types are generated than long answer types. Domains in which this seems to hold include: education9, understanding the needs and goals of one’s audience is an important barrier which must be surmounted. Splitting this task into understanding the subject matter under discussion and the structure of the information sought might aid its completion. Moreover, treating the process as iterative—whereby the answer sought from the question posed is the first step in a dialogue which establishes mutual grounds on which to then revisit the question and how it can be addressed—is also important. Another potential barrier is that scientists have concerns about the possible blurring of lines between acting in the capacity of providing expertise versus advocating64. The findings from this study suggest that this may be warranted, given that the most common type of answer which policymakers invited from scientists was one that involved suggestions for interventions  that serve particular goals. While addressing questions of this type may lead to more impact for the scientific knowledge provided, it may potentially draw scientists into making recommendations, rather than presenting policymakers with factors to consider.A final point to consider concerns important barriers that limit potential science-policy exchanges, thereby retarding the co-production of policy. Since co-production requires a mutual understanding between scientists and policymakersSupplementary Information 1.Supplementary Information 2.


Graphene films made by chemical vapor deposition (CVD) are a popular method to modify sensors by virtue of large-scale and reproducibility, but suffer from various surface contamination and structural defects induced during transfer procedures. In-situ growth of graphene films is proposed in this review article to improve sensing performance. Root causes of the surface contamination and structural defects are revealed with several common transfer methods. In-situ approaches are introduced and compared, growing graphene films with clean surfaces and few defects. This allows graphene film to display superior sensing performance for sensor applications. This work may reasonably be expected to offer a good avenue for synthesis of graphene films applicable for sensing applications. The experimental results are shown in 2, which was much higher than the measurements obtained for the SBDD under the same process (1.6 cm2), and the in-situ graphene modification increased the active area of the electrode by a factor of almost 1.7. The increase in the active area of the electrode is due to the in situ modified graphene film expanding the contact area of the electrode with the electrolyte, which also provides more binding and reaction sites for the redox probe.The electrochemically active area of the electrode is the area of the active site where the probe binds and reacts with the probe ion, and is an important metric for evaluating the sensing performance of the device. In general, the larger the electrochemically active area, the better the sensing performance of the device and the better the modification effect exhibited by graphene. The group measured the electrochemically active area of in situ grown graphene-modified G/SBDD electrodes and unmodified SBDD electrodes, respectively. They used KIn the process of exploring the detection performance of the sensor, it is necessary to focus on the analysis of important indicators such as the standard curve, sensitivity and detection limit of the sensor. The calibration curve shows the linear relationship between the ion concentration and the peak current value of the dissolved ion, and provides a visual representation of the concentration of the detected ion. The degree of change of the dissolved signal with increasing concentration reflects the sensitivity of the detection, and a high sensitivity helps to improve the detection accuracy of the electrode in the low concentration range. The detection limit is the lower limit of detection of the sensor and is an important indicator for determining the effective working range of the sensor .−1 cm−2, while the sensitivity of the SBDD under the same process conditions was only 0.42 μAL μg−1 cm−2 , demonstrating that the in-situ modification of graphene has brought about a significant improvement in detection performance in terms of detection accuracy and detection limits. The enhancement effect of graphene modification on detection performance may be attributed to the superior adsorption capacity and outstanding electronic transmission capacity of graphene. On the one hand, the superior adsorption capacity endows G/SBDD electrode with a stronger enrichment effect on Pb2+, and brings a lower detection concentration than that of SBDD. On the other hand, the outstanding electronic transmission capacity of graphene could significantly facilitate the mass transfer process of the G/SBDD electrode, thus inhibiting the intermediates from participating in the reaction process. The above two facts jointly allow the G/SBDD electrode to acquire a smaller noise and provide a significant improvement on detection limit.As can be seen from shown in b. Furthe2SO4 solution containing 20 ppb Pb2+, and six interfering ions, Ca2+, Mg2+, Zn2+, Fe2+, Cu2+ and Cd2+, were added to the electrolyte to simulate the complex detection environment. The content of the interfering ions was the same as that of Pb2+, all at 20 ppb, and a constant potential of +0.3 V was applied to the electrode at the end of each measurement and held for 100 s to avoid interference with the experiment by residual metal on the electrode surface.Reproducibility and selectivity are important indicators to determine whether the sensor can maintain a stable performance in practical applications. Reproducibility reflects the degree of decay of the detection signal with an increasing number of detections and is an evaluation indicator of the accuracy of the sensor; while selectivity reflects the ability of the sensor to resist interference ions. To investigate the reproducibility of the G/SBDD electrodes, the group performed nine reproducibility experiments. The electrolyte used was a 0.1 M Na2+ remained constant with increasing number of experiments; the peak current values decreased slightly, but the overall decay was low. The relative standard deviation (RSD) of the Pb2+ dissolved peak current values obtained from the nine replicate experiments was calculated and the RSD values were used to represent the accuracy of the electrode. The calculated RSD value of 2.7% for the nine replicate experiments for Pb2+ indicates that the G/SBDD electrode has good reproducibility and reflects the high accuracy of the graphene in situ modified device. From the interference test results shown in 2+ dissolution signal, and the Pb2+ dissolution signal did not change significantly with the addition of Zn2+, Fe2+, Cu2+ and Cd2+. This indicates that the G/SBDD electrodes are more resistant to the above-mentioned heavy metal ions and the inherent metal ions in the water column, demonstrating the good selectivity of the in situ modified Pb2+ sensor.The dissolution curves obtained from the nine replicate experiments are shown in 2+ in 0.1 M Na2SO4 for 60 days for stability testing. The solution was stirred to simulate the flow of water and the Pb2+ content was measured daily using the electrode. In addition, the G/SBDD electrodes were immersed in a solution of 30 ppb PbSystematic analysis and performance comparisons show that the G/SBDD with in situ graphene modification exhibits superior sensing and detection performance compared to the unmodified SBDD electrode. In addition, it has great advantages in terms of device structure, as in-situ graphene modification can significantly improve the device preparation efficiency and device uniformity. It also effectively solves the problem of easy detachment of the sensing layer, which often occurs in transfer graphene modified sensors, and improves the anti-interference capability and service life of the device, which provides a strong guarantee for the normal service of the device in complex detection environments.Earth observation is a description of the current environmental conditions and conditions of human existence, which can provide valuable information to help human beings know the earth’s conditions more clearly. Among them, infrared sensors are commonly used in non-contact temperature measurement, gas composition analysis and nondestructive testing, which are widely used in the field of environmental engineering in earth exploration .Recently, the research team of the Institute of Materials Science of Kaunas University of Technology (KTU) developed a new infrared sensor based on graphene-silicone Schottky contact. This new infrared sensor can help us to observe the Earth and carry out interplanetary missions from space to explore the atmospheres of other planets or look for life on Mars. Dr. Šarūnas Meškinis, the lead researcher of the research team, pointed out that the manufacturing technology for the Schottky contact sensor is much simpler than for other infrared sensors. Multiple arrays of this sensor can be developed on semiconductor boards . Stable structure and simple process are the main advantages of the Schottky contact sensor . However2 lightly doped silicon substrate is selected as the growth substrate, and then the graphene growth window is etched on the surface of the sensor substrate by photolithography. In addition, in order to reduce the diffusion of carbon atoms in the substrate, it is necessary to set the growth temperature to a lower temperature. Finally, the sample is placed on the circuit board of the sensor, the graphene fixed to the electrode by silver glue, the edges of the silver glue and graphene are protected by silica gel to prevent short-circuit leakage of the device, and the device is finished.Based on this, scientists have proposed a Schottky junction photoelectric sensor modified by graphene grown in situ without metal catalysis ,60. DiffThe device structure is shown in The performance and structure of the Schottky photoelectric sensor constructed by in-situ growth of graphene film are compared with those of graphene-silicon photoelectric sensors reported in the previous literature , which is used to improve the current spreading on the surface of the LED. As a rare metal, indium is a non-renewable resource, which leads to the high price of ITO material, and hence, the application range of blue LED sensor is greatly limited. While carbon is abundant in the earth, graphene also has good light transmittance and conductivity, so it is an excellent material to replace ITO. The in-situ growth temperature of graphene on gallium nitride (GaN) surface should not be too high, because this would destroy the epitaxial structure of LED . TherefoThe growth of graphene needs to be catalyzed by cobalt metal. At the same time, graphene also acts as the current spreading layer of p-GaN . Therefore, cobalt can be used as both the etching mask of p-GaN mesa and the catalyst of graphene, which can greatly reduce the process steps. Tang et al.  put forw2 or Ni is usually used as the mask for etching GaN [2/Si substrate was prepared, and graphene was grown in situ under the same conditions to characterize the quality of graphene. Graphene is grown on the surface of cobalt, so from the growth mechanism, the SiO2/Si substrate or GaN substrate should have no influence on the quality of the graphene. In the traditional GaN device process, metal such as SiOhing GaN ,65. GaN The above results demonstrate that in-situ grown graphene has an obvious modification effect, and the performance of LED devices is thus improved. At present, the quality of graphene still needs to be further improved, and its conductivity is still far behind that of traditional ITO. In this way, doping may be considered to improve the conductivity. In addition, how to reduce the contact resistance between graphene and GaN is still an urgent problem. Graphene and GaN have large contact resistance, and limit the improvement of device performance. Intercalation between graphene and GaN may be tried to improve the contact resistance.This paper reviews preparation methods of in-situ grown graphene films and their modification techniques to overcome drawbacks of surface contamination and structural defects that are prevalent in the transfer process. Three in-situ methods are metal-free catalytic growth, metal-assisted growth and plasma-enhanced growth. In-situ growth enables the graphene films to share clean surfaces and few defects. Moreover, this approach may get rid of complex transfer and post-cleaning steps, and facilitates in-situ functional modification of the devices. The application of in-situ graphene films is also explored in the sensing field.There has been much progress in developing in-situ grown graphene films, and some efficient and feasible methods have been made available. Research on the sensing applications is still in the exploratory stage, and the in-situ growth techniques developed so far have a long way to go before the large-scale promotion and application in the sensing field. The output of this work may serve as a good inspiration and reference for the large-scale development of in-situ graphene films for sensing applications.


The transferred graphene flakes demonstrated good adhesion and emission characteristics.A new approach to the fabrication of graphene field emitters on a variety of substrates at room temperature and in an ambient environment is demonstrated. The required shape and orientation of the graphene flakes along the field are created by the blister-based laser-induced forward transfer of CVD high-quality single-layer graphene. The proposed technique allows the formation of emitting crumpled graphene patterns without losing the quality of the initially synthesized graphene, as shown by Raman spectroscopy. The electron field emission properties of crumpled graphene imprints 1 × 1 mm The transition from bulk to low-dimensional materials has opened up new opportunities in the creation of new electronic elements and the modification of existing ones, particularly field emitters, due to their adjustable band gap and promising electronic properties ,2,3,4. TGraphene field emitters can be produced by different techniques, such as micromechanical exfoliation ,19, chemThe method of BB-LIFT consists of local laser surface evaporation of a thin absorbing layer, such as metal, covering a transparent substrate, usually quartz. As a result, a blister is formed at the interface between the quartz and the metal film, which pushes the transferred material lying on the metal from the irradiated substrate (donor) to the receiving substrate (acceptor). The obvious advantages of the proposed approach are the variety of substrates available for the emitters and their arbitrary shape. Here, we report the results of the BB-LIFT technique applied to the printing of pixels of crumpled graphene and of the emission test of the field-emission cathodes fabricated in this way.−5 mbar) on the surface of a polished quartz substrate from a molybdenum boat heated to 900 °C by the current passing through it (resistive heating). The thickness of the aluminum film was measured by the white-light interferometer Zygo NewView 5000 (USA) and amounted to 1900 nm. A single-layer polycrystalline graphene film grown on copper foil by CVD technique was transferred to the metal surface of the donor sample by a standard wet method using poly(methyl methacrylate) as a supporting polymer, which was chemically removed after the transfer [For donor-sample preparation, an aluminum film was deposited in a vacuum chamber . The scheme of irradiation is shown in The quality of graphene on the donor and acceptor substrates was characterized using Raman spectroscopy (Horiba LabRAM HR Evolution spectrometer (Japan) with λ = 532 nm) and scanning electron microscopy (SEM) (TESCAN Mira 3 (Czech)). The surface morphology was also analyzed using an Axiotech 25HD optical microscope (Carl Zeiss (Germany)).−6 mbar and room temperature. The acceptor substrate (cathode) was installed on a holder parallel to the anode at a distance d = 400 µm under it. A DC voltage was applied between the cathode and anode, causing the emission of electrons from the graphene flakes. As a result, the current–voltage (I/U) dependences were measured.FE properties of the two acceptors were studied in a flat vacuum diode configuration at 102. In this work, we used the fluence of 2.3 J/cm2, which is the most promising value for imprint quality. The lower values did not cause the complete transfer of the graphene from the donor substrate. The higher values could lead to structural damage to the graphene due to its overheating. The result of the BB-LIFT of the single-layer graphene film after one and three passes is shown in 2 with a relatively uniform distribution of graphene flakes on the acceptor substrate. The SEM images (The working range of laser fluence for graphene flake transfer determined in our previous work  is 1.2–2M images  indicateM images  and elecM images  microsco−1) on the flakes was an order of magnitude lower than the G peak (1580 cm−1), but according to the shape of the transferred graphene from the donor to the acceptor, two varieties were highlighted, which were clearly distinguishable in the Raman spectra. The first type was areas that were weakly visible in the optical images, and corresponded to the Raman spectra of the graphene monolayer. The Raman spectra of these areas had a high ratio of 2D (2670 cm−1) to G peak intensities (more than 2) and narrow 2D peaks (less than 35 cm−1). We suppose that in these regions, the graphene monolayer was transferred from the donor to the acceptor without morphological changes, in the form of so-called flat graphene. The main part of the transferred material, which was already clearly visible by optical methods (dark areas), was crumpled graphene, with the ratio of the intensities of the 2D and G peaks  views. Essentially, in the transferred carbon material, there were separate, highly crumpled sections of film, both of which were in strong contact with the substrate and were located at a large angle from the surface of the copper film, rising steeply (up to ~10 μm) and touching it in only a few points . A possi G peaks  correspo 2D peak .thrE at the current density J = 1 mA/cm2 occurred at 4.4 and 4 V/µm for the single- and three-passed patterns, respectively. Due to the higher graphene flake density, the emission current was larger for the three-passed area over the entire range of applied voltage. The observed differences in emission characteristics were previously reported for CNT films with different thicknesses [maxJ for the single- and three-passed patterns were 10.6 and 15.6 mA/cm2, respectively. It should be mentioned that the ratio maxJ1max/J3 = 1.5 correlated with the ratio of the surface coverage densities of the graphene flakes 17.9/10.6 = 1.7. The current–voltage characteristics of the single- and three-passed patterns in the Fowler–Nordheim (FN) coordinates (ln (I/U2) vs 1/U) are presented in β can be calculated from the FN plots using the following equation β = −bϕ3/2FN/k, where b = 6.83 × 103 eV−3/2 V−1 µm, ϕ is the work function of the graphite (5 eV), and FNk is the slope of the FN plot [thrE = 4 V/µm, β = 3300) were comparable with those of other fabrication methods . Furtheβ = 3000  that inc2 in size were tested and demonstrated Fowler–Nordheim behavior. The measured emission characteristics were comparable with those of other fabrication methods, despite the transferred graphene flakes covering only 18% of the entire surface. Further research will be aimed at obtaining the optimal density and uniformity of graphene pattern-emitting electrons.A new approach to the fabrication of graphene-based field emitters was developed. The technology demonstrated in this study is simple and based on the BB-LIFT of CVD high-quality single-layer graphene from the donor substrate to the acceptor, which results in the formation of emitting crumpled graphene pixels. The quality of the transferred graphene was maintained and corresponded to that of the single-layer graphene folded two or three times, as shown by Raman spectroscopy. The electron field emission properties of the crumpled graphene imprints 1 × 1 mm


A metal–graphene metamaterial device exhibiting a tunable, electromagnetically induced transparency (EIT) spectral response at terahertz frequencies is investigated. The metamaterial structure is composed of a strip and a ring resonator, which serve as the bright and dark mode to induce the EIT effect. By employing the variable conductivity of graphene to dampen the dark resonator, the response frequency of the device shifts dynamically over 100 GHz, which satisfies the convenient post-fabrication tunability requirement. The slow-light behavior of the proposed device is also analyzed with the maximum group delay of 1.2 ps. The sensing performance is lastly studied and the sensitivity can reach up to 100 GHz/(RIU), with a figure of merit (FOM) value exceeding 4  Terahertz (THz) radiation has many unique applications in sensing, imaging, spectroscopic analysis, and communications ,2. The dIn recent years, actively controllable graphene-based metamaterials have been widely studied at terahertz frequencies ,27,28,29In order to enlarge the frequency tuning range, we designed a metamaterial structure consisting of a strip and a ring resonator integrated with graphene, which demonstrated a frequency tuning range over 100 GHz based on the electromagnetically induced transparency (EIT) effect. The main advantage of this method is that it exploits the tunable loss of graphene, instead of high carrier mobility, to realize frequency tuning. When THz wave incidents on the device surface, the strip resonator couples strongly with the incident field and supports a bright mode, whereas the ring resonator is indirectly activated by the bright mode through near-field coupling and supports a dark mode. The bright–dark mode coupling induces the electromagnetically induced transparency effect ,32. The j is the imaginary unit, e is electron charge, ħ is the reduced Planck’s constant, and The graphene conductivity consisting of the interband and intraband contributions is derived from Kubo’s formula: nsitions ,38, whicsitions [σintra=jeectively .The Q factors  and a figure of merit (FOM) as the quality factors . The speAs shown in In conclusion, a dynamically controllable terahertz metamaterial consisting of a strip and a ring resonator with graphene integration is investigated. The strip resonator is strongly excited by the incident field and serves as bright mode, while the ring resonator is excited through near-filed capacitive coupling with the bright resonator and serves as dark mode. The bright–dark mode coupling induces the EIT effect. The resonance frequency of the device is tuned over 100 GHz by adjusting the graphene conductivity to dampen the dark resonator. The slow-light behavior of the device is also studied with the maximum group delay of 1.2 ps. Furthermore, the device can be utilized as an effective refractive index sensor with a sensitivity of 100 GHz/RIU and a FOM value above 4


Graphene conductive inks have attracted significant attention in recent years due to their high conductivity, corrosion resistance, and environmentally friendly nature. However, the dispersion of graphene in aqueous solution is still challenging. In this work, we synthesized an amphiphilic graft copolymer, polyvinyl alcohol-g-polyaniline (PVA-g-PANI), and studied the graphene dispersion prepared with the graft copolymer by high-speed shear dispersion. The amphiphilic graft copolymer can be used as a stabilizer and adhesive agent in graphene dispersion. Given the steric hindrance of the graft copolymer, the stability of graphene dispersion is improved by decreasing the probability of π–π stacking. PVA-g-PANI has a better stability on graphene dispersion than carboxymethylcellulose sodium (CMC-Na) and a mixture of PVA and PANI. The graft copolymer has only a slight effect on the conductivity of graphene dispersion due to the existence of conductive PANI, which is beneficial for preparing the graphene dispersion with good conductivity and adhesion. Graphene dispersion is well-adapted to screen printing and is very stable with regard to the sheet resistance bending cycle. With the rapid development of the electronic industry, conductive ink has been applied in various fields, such as flexible printing circuits, film switcsh, and radio frequency identification ,2. GraphGraphene in water can easily agglomerate and hardly obtains a stable aqueous solution due to its unique surface energy . The aggThe synthesis and self assembly of copolymers have been extensively studied ,22,23. S2, which was used as a film electrode in the super capacitor, and the device has a longer cycle life. However, PANI has a low solubility in solvents and poor film-forming properties, which adversely affects its application progress. Polyvinyl alcohol (PVA) is a water-soluble polymer and has good biocompatibility, good film-forming properties, and the strength and flexibility of the film after forming can basically meet the requirements of film applications [Polyaniline (PANI) is one of the earliest conductive polymer materials that has attracted much attention due to its low cost, easy synthesis, unique doping mechanism, high conductivity, and excellent redox property ,28,29,30ications ,33.In this study, we designed and synthesized an amphiphilic graft copolymer and used it as a stabilizer and adhesive to improve the stability of the graphene aqueous solution, the electrical conductivity of graphene dispersion, and the adhesion of graphene film on Biaxially Oriented Polypropylene (BOPP). A stable and highly conductive graphene dispersion was obtained via the high-speed shear method. We studied the stability, screen printing adaptability, and physicochemical and electrical properties of the graphene dispersion. The introduction of PVA-g-PANI into graphene dispersion provides a new, environmentally friendly approach to preparing stable and uniform graphene aqueous dispersions.Graphene (GS-1) was purchased from Ningbo Moxitech Co., Ltd., Ningbo, China. Poly , ammonium persulphate (APS), and CMC-Na  were obtained from Aladdin  and used without further purification. Epichlorohydrin (EPIC), dimethyl sulfoxide (DMSO), triethylamine, and acetone were purchased from J&K chemic Tech Co., Ltd., Tianjin, China. Aniline was purchased from Macklin  and purified before use. Tetrabutyl ammonium chloride  was purchased from Tianjin Biochemical Tech Co., Ltd., Tianjin, China. NaOH and hydrochloric acid solution were purchased from Sinopharm Chemical Reagent Co., Ltd. . BOPP, polyimide, and polyethylene terephthalate film were obtained from the Beijing research institute of the chemical industry. A stable dispersed graphene solution was prepared using the high-speed shear method. Firstly, 2.8 g of graft copolymer was directly dissolved in 105 mL of deionized water to obtain a solution. Then, 3.75 g of graphene was added into the solution, and the mixture was sheared by a high-speed shear dispersing emulsifier  to obtain a graphene dispersion. The experiments were performed for 1 h with a speed of 4000 rpm at room temperature. Furthermore, the prepared dispersions were deposited on substrates by using screen printing.2O) as a solvent. The electrical properties of the films were measured using a four-probe tester  and a multimeter . UV−Vis spectra measurements were carried out on a UV-1800 spectrophotometer, Karlsruhe, Germany. The adhesion test was measured using an adhesion tester (QFH) via the cross-cut test. The viscosity of the graphene dispersion was measured using a digital rotary viscometer . TEM measurements were carried out on a transmission electron microscope . SEM measurements were carried out on a scanning electron microscope . Rheological characterization of the ink was conducted using a rotational rheometer .FTIR spectra were recorded on a Tensor-27 spectrometer . 1H NMR spectra were obtained on a Bruker AV400 spectrometer using deuterium oxide (D−1. The FTIR spectrum of the etherified PVA (−1 and the C–Cl characteristic band at 712 cm−1, indicating that the etherified PVA was successfully prepared. The FTIR spectrum of the N-alkylated product (−1 and the characteristic band of aniline at 693 and 759 cm−1. Moreover, the C–Cl characteristic band disappeared, indicating that the etherified PVA and aniline were successfully connected. The PVA-g-PANI (We developed a simple method to prepare PVA-g-PANI, as displayed in fied PVA a shows t product b shows tA-g-PANI c presentA-g-PANI a. Graphene dispersion prepared with PVA-g-PANI is a viscous paste with a viscosity of 8000 mpa·s , which iThe TEM images of graphene dispersion and graphene dispersion prepared with PVA-g-PANI are shown in The graphene ink prepared with PVA-g-PANI is shown in When the ink has appropriate rheological characteristics, we can obtain the printing pattern that has more smooth edges and a higher resolution through screen-printing technology. Furthermore, the defects and bubbles in the printing patterns must be eliminated, and the conductivity of the printing patterns must be improved. In In The screen printing pattern was cut into 4 mm wide and 10 cm long straight lines. The resistance of the line gradually decreases with the increase in printing cycles. When the printing time is up to eight, the resistance can decrease from the initial 32 KΩ to 9.8 KΩ a. This pThe cross-cut test was used to estimate the adhesion of the graphene/PVA-g-PANI film on the flexible BOPP substrate. The result is shown in We presented a study on the stability, screen printing adaptability, and electrical properties of graphene dispersions using amphiphilic graft copolymers of PVA-g-PANI. The stable graphene dispersion was prepared via high-speed shear. 1H NMR and FTIR were used to characterize the structure of graft copolymers, and their results confirm that amphiphilic PVA-g-PANI was successfully synthesized. The UV–Vis absorption spectral results and the TEM images confirm that PVA-g-PANI can efficiently improve the stability of graphene in the aqueous solution, better than CMC-Na and the mixture of PVA and PANI. Moreover, the PVA-g-PANI is beneficial for preparing the graphene dispersion with good conductivity. The prepared graphene dispersion is very adaptable for screen printing and is very stable regarding the sheet resistance bending cycle. This study offers a simple, scalable, and environmentally friendly approach to produce stable and uniform graphene aqueous dispersions via a high-speed shear dispersing method.


Condensin I and condensin II are multi-subunit complexes that are known for their individual roles in genome organization and preventing genomic instability. However, interactions between condensin I and condensin II subunits and cooperative roles for condensin I and condensin II, outside of their genome organizing functions, have not been reported. We previously discovered that condensin II cooperates with Gamma Interferon Activated Inhibitor of Translation (GAIT) proteins to associate with Long INterspersed Element-1 (LINE-1 or L1) RNA and repress L1 protein expression and the retrotransposition of engineered L1 retrotransposition in cultured human cells. Here, we report that the L1 3′UTR is required for condensin II and GAIT association with L1 RNA, and deletion of the L1 RNA 3′UTR results in increased L1 protein expression and retrotransposition. Interestingly, like condensin II, we report that condensin I also binds GAIT proteins, associates with the L1 RNA 3′UTR, and represses L1 retrotransposition. We provide evidence that the condensin I protein, NCAPD2, is required for condensin II and GAIT protein association with L1 RNA. Furthermore, condensin I and condensin II subunits interact to form a L1-dependent super condensin complex (SCC) which is located primarily within the cytoplasm of both transformed and primary epithelial cells. These data suggest that increases in L1 expression in epithelial cells promote cytoplasmic condensin protein associations that facilitate a feedback loop in which condensins may cooperate to mediate L1 repression. Condensin I and condensin II are multi-subunit protein complexes that play fundamental roles in chromosome organization and mitotic chromosome segregation  and alsoAlthough the nuclear roles of condensin proteins are well studied, little is known about their cytoplasmic functions. We recently demonstrated that the condensin II complex represses the expression of endogenous Long INterspersed Element-1 (LINE-1 or L1) proteins and the retrotransposition of engineered human L1s in human epithelial cells . L1-deriHere, we report that the L1 RNA 3′UTR is necessary for condensin II and GAIT association with L1 RNA. We further show that Condensin I also associates with the L1 RNA 3′UTR and may mediate condensin II and GAIT association with L1 RNA. Finally, we demonstrate that, in response to L1 expression, subunits of the condensin I and condensin II complexes interact to form a primarily cytoplasmic, L1 3′UTR independent, Super Condensin Complex (SCC) in response to L1 expression. Together, these data uncover potential cooperative roles for cytoplasmic condensin complexes in the inhibition of L1 expression and retrotransposition.2 levels.All mammalian cell culture lines were obtained from the American Type Culture Collection (ATCC). HT-29 cells (HTB-38) were cultured in RPMI 1640 media supplemented with 10% fetal bovine serum  and 1% penicillin/streptomycin (Gibco). The hTERT RPE-1 cells  were cultured in DMEM media supplemented with 10% FBS (Life Technologies) and 1% penicillin/streptomycin (Gibco). Cells were grown in a 37°C incubator with 5% COLentiviral transduction was performed in HT-29 cells using custom viral particles produced with the pLKO-puro-IPTG-3xLacO vector (Sigma-Aldrich). As described previously , in the 2. The following day, growth medium was prepared containing 8μg/ml of polybrene and was added to each well. HT-29 cell lines expressing Non-target (NT) and NCAPD3 shRNAs were previously described , the Epstein Barr Virus Nuclear Antigen-1 gene (EBNA-1), and cis-acting sequences (oriP) required for plasmid replication in human cells.A mammalian expression vector (Life Technologies) used to construct some L1 expression plasmids (indicated below). The plasmid is augmented with a cytomegalovirus (CMV) immediate early promoter and an SV40 polyadenylation signal. The plasmid backbone also contains a hygromycin resistance selectable gene (mneoI retrotransposition indicator cassette in its 3′ UTR (A pCEP4-based plasmid that contains an active human L1 (L1.3) equipped with a s 3′ UTR ,58.A pCEP4-based plasmid that contains a version of pJM101/L1.3 harboring the sequence [5′-ACAATGAGTTTAAACGTATACATATGTAACTAA-3′] in the place of the full-length 3′UTR see .The following primary antibodies were utilized throughout this study for immunoblot analyses, immunoprecipitation experiments, or Proximity Ligation Assays: NCAPD3 , NCAPD2 , NCAPG2 , NCAPG , EPRS , eIF4G , Actin , Normal Rabbit IgG , SMC4 , SMC2 , NCAPH2 , β-tubulin . Purified polyclonal α-ORF1p was generated by OpenBiosystems and characterized in the laboratory of John V. Moran (University of Michigan School of Medicine) ,60.4 per well were seeded into two sets of six-well plates tissue culture plates (Corning). For assays involving shRNA mediated knockdown of condensin proteins, clonally expanded cell lines described above were treated with IPTG for 48 hours to induce shRNA expression. Subsequently (and in experiments that did not involve shRNA induction), cells were transfected with 3 μg of the indicated L1 expression plasmid using 8 μl of the Lipofectamine 2000 transfection reagent (Invitrogen) per well. Seventy-two hours after transfection, cells were collected from one set of plates and the pellets were frozen at -80°C for future analysis. Cells from the other set of plates were treated with 0.05% trypsin/0.53 mM EDTA and resuspended in complete RPMI medium supplemented with G418 (600μg/ml) (Life Technologies). Cells from each well were plated onto three 10-cm tissue culture dishes, generating triplicate cultures. After 10 days of G418 selection, the remaining cells were treated with 5 mL of 10% formaldehyde in PBS at room temperature for 5 min to fix them to tissue culture plates, stained with 0.05% crystal violet in PBS for 30 min, washed twice with PBS, and imaged with a ChemiDoc XRS+ (Bio-Rad). The images were analyzed using ImagePro Plus 7.0 software. For one 10-cm dish, a circular area of interest (AOI), which delimits the population of pixels in the image was made. The same AOI was used as a template for each subsequent image analyzed. The number of drug-resistant foci were determined within the AOI and recorded for statistical analysis.Retrotransposition assays were performed as described previously with minor modifications ,61–63. BImmunoprecipitation and immunoblotting to detect proteins of interest were performed as described previously . Bands w−ΔΔCt) where the Ct values of a reference gene (actin) in each sample are subtracted from the Ct values of the gene of interest to create a ΔCt value for each sample. The ΔCt is compared to a control sample to generate a ΔΔCt value for each sample. Following calculation of 2−ΔΔCt for each sample, triplicates were averaged. Three, independent biological replicates were performed in all experiments, and the results of the three assays were averaged together, and standard deviations were calculated. L1 primer sequences were previously published . The RNAs were then treated with RNase-free DNase in buffer RDD (Qiagen) prior to further purification using a RNeasy Mini Kit (Qiagen). An aliquot of cDNA was generated from 1–2 μg of total RNA using the TaqMan Reverse Transcription Reagents (Applied Biosystems) and an oligo-dT(16) primer (Invitrogen). Quantitative RT-PCR was performed using the Roche Lightcycler 480 to amplify 15 μl reactions containing .5 μl of cDNA, .5 μl of a 10 μM primer mix and 7.5 μl of Fast Start SYBR Green Master Mix (Roche). Each reaction was performed in triplicate. Crossing point (Cp/ Ct) values were determined using the Roche LightCycler 480 Absolute Quantification Second Derivative Analysis software. Relative quantitation of transcript levels was then performed using the delta delta Ct method  were washed twice with cold PBS and then incubated with 6 μg of NCAPD2, NCAPD3, NCAPG, EPRS or eIF4G antibody, overnight, at 4°C, on a rocker, followed by two additional washes with cold PBS. Forty-eight hours post-transfection, cells were harvested and crosslinked in 1% formaldehyde in PBS for 10 minutes at room temperature, with rotation. 0.125 M glycine, pH 2.8 was added to quench the reaction; cells were incubated in this solution for 10 min at room temperature, with rotation. Cells were washed in PBS and resuspended in high salt lysis buffer ; 0.5 ml buffer per 6 × 106 cells was used in each experiment). Lysates were then dounce homogenized 10 times and centrifuged at 14 000g for 15 min at 4°C. Each set of transfections was pooled together and re-aliquoted into three tubes per experimental condition. Lysates (0.5 ml) were pre-cleared with 50 μl of a Protein A Dynabead slurry containing 50% cold PBS and 50% Protein A Dynabeads that had been washed 2× with cold PBS. Preclearing was performed on a rocker at 4°C for 1 h. Lysates were then incubated with the Dynabead-antibody mixtures overnight, at 4°C, on a rocker. Beads were then washed once with high salt lysis buffer for 10 minutes, at 4°C, on a rocker, and once with cold PBS for 10 min, at 4°C, on a rocker. One hundred μl of beads were removed and boiled with 25 μl Laemmli buffer for 10 min; these protein samples were used to perform immunoblotting. Eighty μl of 50 mM glycine, pH 2.8, was then added to the remaining beads, and this solution was heated at 70°C for 45 min to reverse crosslinks. Trizol LS  was added to the supernatants, and RNA was isolated according to the manufacturer's protocol. RNA was purified on an RNA-easy column, including an on-column DNAse digestion (Qiagen); cDNA was then generated using the entire sample and TaqMan Reverse Transcription Reagents with random hexamers (Applied Biosystems). The qRT-PCR reactions were performed as described above, using 1 μl of cDNA per reaction. The primers used to detect transfected L1 RNAs were directed against the neomycin resistance cassette present in pJM101/L1.3 and pJM101/L1.3 3′UTRΔ  was used to transfect either Non-Targeting siRNA  or L1 siRNA directed against ORF1p (5′-GAAAUGAAGCGAGAAGGGAAGUUUA-3′)  intoo tested ,67  or NCAPD2 (anti-mouse) were added to each sample and allowed to incubate overnight at 4°C. The next day, the primary antibody was removed, the coverslips were washed in supplied buffers, according to manufacturer's protocol, and the PLA probe solution was applied to each sample. The samples were incubated in a pre-heated humidity chamber for 60 minutes at 37°C. The PLA probe solution was removed and the samples were washed in supplied buffers, according to manufacturer's protocol. The ligation solution was applied according to manufacturer's protocol and the samples were incubated in a pre-heated humidity chamber for 30 min at 37°C.The ligated samples were washed in supplied buffers according to manufacturer's protocol and the amplification solution provided in the kit (containing DNA Polymerase) was applied according to manufacturer's protocol. The samples were again incubated in a pre-heated humidity chamber for 100 min at 37°C. Finally, the samples were washed in supplied buffers, according to manufacturer's protocol and then mounted to a glass slide using a one drop of Duolink® In Situ Mounting Medium with DAPI. At least three independent images were taken from different locations on a coverslip using a Leica SP8 DMI8 inverted confocal microscope (63× objective). One coverslip was considered to be an independent experiment; at least two independent experiments were performed for each condition tested. Nuclear PLA foci were identified and quantified from 3D images of individual focal planes within z-stacks, using Volocity 3D Image Analysis Software v 6.5.1 . Compartmentalization analysis of the PLA foci within the 3D images allowed us to quantify foci that localized within the DAPI-stained nuclear compartment. The remaining PLA foci located outside of the nucleus were also quantified for each image. The total numbers of nuclear foci and cytoplasmic foci were divided by the total number of nuclei present in the image to obtain the average number of nuclear or cytoplasmic PLA foci/cell. Between 50 and 150 nuclei were evaluated per image.The proximity ligation assay was performed using the DuoLink® PLA kit (Sigma Aldrich) according to the protocol provided by the manufacturer. An illustration of the protocol is available at Assays to monitor the potential cytotoxicity of RT inhibitors were performed as previously described . RT inhiThe cell-based retrotransposition assay was conducted as described above. Seventy-two hours after transfection, the cells were trypsinized and plated onto three 10cm plates in RPMI medium containing 600 μg/ml G418 and 50 μM RT inhibitors Didanosine and Zidovudine (Sigma Aldrich). RPMI medium containing 600 μg/ml G418 and 50 μM DMSO was added to the mock treated plates. Two weeks post-transfection, G418 resistant cells were fixed to the plate and stained with 0.1% crystal violet, using the same procedure described above for retrotransposition assays, to calculate the retrotransposition frequency. Three independent assays were performed for each experiment.n = 3 independent experiments performed under identical conditions). Statistical analyses were performed using GraphPad Prism© (GraphPad Software) with an unpaired Student's t-test. A P-value < 0.05 was considered statistically significant.Data are expressed as mean ± SD  or a L1 harboring a deletion of sequences within its 3′UTR (pJM101/L1.3 3′UTRΔ) . RNA-immThe ability of condensin II to repress L1 retrotransposition prompted us to ask whether the other condensin complex present in eukaryotic cells, condensin I, may also act to repress L1 retrotransposition. Thus, we generated HT-29 cells expressing inducible small hairpin RNAs (shRNA) targeting the condensin I subunits NCAPD2 (Sigma TRCN0000115682 as shRNA#1 and Sigma TRCN0000244475 as shRNA #2) and NCAPG (Sigma TRCN0000143554) Figure –C, F, G,We next conducted RNA-IP/qRT-PCR experiments in HT-29 cells transfected with pJM101/L1.3 or pJM101/L1.3 3′UTRΔ to determine whether condensin I protein, NCAPD2, associates with L1 RNA. Immunoprecipitation of NCAPD2 protein, followed by qRT-PCR analyses to detect co-precipitated L1 RNAs, revealed that NCAPD2 significantly associated with full length L1 RNA when compared to negative control RNA-IP reactions without an antibody or with IgG antibody Figure . MoreoveWe next tested whether NCAPD2 could behave similarly to condensin II proteins and associate with EPRS protein. Indeed, immunoprecipitation of EPRS co-precipitated NCAPD2 protein in HT-29 cells Figure . To testBecause condensin I and condensin II modestly repress L1 retrotransposition and NCAPD2 promotes condensin II protein association with L1 mRNA in HT-29 cells, we next tested whether condensin I and condensin II can interact. Reciprocal co-IP/immunoblot experiments demonstrated an association between NCAPD2 and NCAPD3 in whole cell lysates prepared from HT-29 cells Figure . A similin situ detection of endogenous proteins in close proximity to one another (see Methods), revealed that SCC formation primarily occurred in the cytoplasm and that L1 siRNA transfection decreased SCC formation by approximately 3-fold in both the nucleus and cytoplasm when compared to control siRNA treated cells . Transfection of the L1 siRNA led to a ∼2-fold decrease in both L1 RNA and L1 ORF1p levels in cells , but dids Figure –E.per se, may play a role in SCC formation in HT-29 cells.L1 retrotransposition requires L1 ORF2p reverse transcriptase activity ,70 and tTo analyze whether SCC formation also occurred in primary cells, we transfected human RPE-1 cells, which are a hTERT-immortalized, non-transformed, primary cell line, with the pCEP4 empty vector or the pJM101/L1.3 expression vector Figure –D. Quantvs. pJM101/L1.3 3′UTRΔ transfected cells  L1 expression promotes interactions between condensin I and condensin II to form SCCs which are primarily located within the cytoplasm of human epithelial cells; (ii) condensin I and condensin II proteins can associate with GAIT complex proteins and the L1 RNA 3′UTR; (iii) the condensin I subunit, NCAPD2 promotes the association of condensin II and GAIT proteins to RNA sequences and/or structures within the L1 3′UTR and (iv) the condensin I and condensin II proteins can repress L1 ORF1p expression and L1 retrotransposition.The above findings suggest a working model where L1 RNA expression stimulates the SCC formation in a L1 RNA dependent, but L1 RNA 3′UTR independent manner. After its formation, the SCC complex, through the actions of condensin I and condensin II complexes, then can associate with RNA sequences and/or structures within the L1 3′UTR to repress L1 ORF1p translation and L1 retrotransposition Figure .The L1 3′UTR, which contains a putative GAIT element , is requOur data further reveal that L1 expression stimulates SCC formation, but that SCC formation does not strictly require sequences within the L1 RNA 3′UTR Figures  and 5. INotably, previous studies revealed that although the L1 3′UTR is not strictly required for retrotransposition , it contCondensin I and condensin II generally are thought to be independent protein complexes that play roles in similar, yet distinct, cellular functions ,3,86. PrWhether SCCs form in the free cytosolic space or in association with specific cytoplasmic organelles requires further elucidation. Our laboratory recently demonstrated that condensin subunits localize to the outer membrane of mitochondria and within mitochondrial matrices and that condensin II regulates mitochondrial respiration and prevents reactive oxygen species (ROS) accumulation in response to stress . A previThe consequences of SCC formation in cellular homeostasis, if any, also requires elucidation. We only observed a small number of SCCs , Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic.Further information and requests for reagents can be directed to and will be fulfilled by the corresponding author Michelle S. Longworth (gkac802_Supplemental_FileClick here for additional data file.