In this paper, we report a cost-effective and scalable approach to produce highly homogeneous graphene and CNT-based silicone composites with potential applications in diverse fields of research, including biosensors and wearable electronics. This approach includes the fabrication of hybrid fillers based on few-layer graphene and CNTs by water solution blending and manufacturing of graphene/CNT/PDMS composites through calendering in a three-roll mill. The influence of processing parameters, the graphene/CNT ratio, and hybrid filler loading was thoroughly investigated, and the optimal parameters for producing hybrid composites with superior electrical and mechanical properties were found. It was also confirmed that the graphene/CNT hybrid system exhibits a synergistic effect of non-covalent interactions between graphene sheets and CNT sidewalls. This synergistic effect prevents the aggregation of graphene sheets, facilitates the dispersion of graphene and CNTs in the silicone matrix, and contributes to the superior properties of hybrid composites compared to composites with either of these fillers alone. In recent decades, a great deal of attention has been paid to the development of biomaterials for application in various fields, such as health monitoring, clinical surgery, tissue engineering, and drug delivery ,2,3. MosThe stretchable and conductive polymer composites are of particular interest for use in bioelectronics, especially for the manufacturing of biosensors, and bioimplants . The sufDuring the last decade, graphene and CNT-based elastomeric composites have attracted much attention of researchers and have been considered as the most promising for biomedical applications ,10. A unVarious methods have been proposed to enhance the dispersion of graphene or CNTs in a polymer matrix, including ultrasonic treatment, stirring, ball milling, shear mixing, solution blending, use of surfactants, and chemical functionalization ,14. Neve2-hybridized graphene sheets and CNT sidewalls, which prevent the aggregation of individual graphene sheets and promote their dispersion in polymer composites.Recently, three-dimensional G/CNT hybrid materials have been proposed for the manufacturing of highly homogeneous composites with potential applications in diverse fields of research, including supercapacitors, batteries, and biosensors . The mosAlthough many researchers have studied the polydimethylsiloxane (PDMS) composites with either CNTs or graphene fillers, there have been few studies on properties of silicone composites containing CNT–graphene hybrid materials ,24,25,26Overall, the discussed studies have demonstrated that the synergistic effect of CNT and graphene interactions facilitates their dispersion in the silicone matrix and contributes to superior properties of hybrid composites compared to composites with either of these fillers alone. However, the composite fabrication techniques employed in these studies have some significant drawbacks for biomedical applications. In particular, the production of G/CNT hybrid fillers has been carried out mainly through a solution blending method involving the use of solvents  and water suspension of few-layer graphene (FLG)  were supplied by NanoTechCenter, Ltd., Tambov, Russia. The Sylgard 184 silicone elastomer kit (10:1 mix ratio) was supplied by Dow Corning, Midland, MI, USA.®, Manassas, VA, USA. Eagle’s Minimum Essential Medium (EMEM) and 1% penicillin-streptomycin solution were purchased from PanEco, Moscow, Russia. 10% fetal bovine serum (FBS) was supplied by BioSera, Ringmer, UK. 1 µM retinoic acid was purchased from Sigma, St. Louis, MO, USA. 3--2,5-diphenyl tetrazolium bromide (MTT) reagent was supplied by Dia-M, Moscow, Russia. Dimethyl sulfoxide (DMSO) was supplied by Applichem, Omaha, NE, USA.A human neuroblastoma SH-SY5Y cell culture for cytotoxicity research was supplied by ATCCThe water suspension of FLG was divided into six parts, and five of them were filled with a proper amount of CNTs to produce G/CNT  hybrids. All mixtures were intensively stirred in an ultrasonic bath  for 20 min, and then all samples (including a pristine graphene sample) were dried in a vacuum oven at 110 °C until constant weight was achieved. Finally, the dried samples were processed in a disintegrator for 4 min to obtain a fine, homogeneous and non-agglomerated product.bρ) of fillers. The upper concentration limit of 10 wt.% was reached for low-density fillers such as CNTs (bρ = 0.025 g/cm3) and hybrids with G/CNT mass ratios of 2:8 (bρ = 0.086 g/cm3) and 4:6 (bρ = 0.131 g/cm3). The upper concentration limit of 20 wt.% was reached for high-density fillers such as graphene (bρ = 0.29 g/cm3) and hybrid with the G/CNT mass ratio of 9:1 (bρ = 0.184 g/cm3). For the middle-density fillers such as hybris with G/CNT mass ratios of 6:4 (bρ = 0.150 g/cm3) and 8:2 (bρ = 0.168 g/cm3), the upper concentration limit was found to be 15 wt.%.Further, the upper concentration limits of graphene, CNTs, and G/CNT hybrid fillers in silicone composites were studied. The upper concentration limit is the maximum amount of filler that can be incorporated in the silicone matrix while maintaining a visible uniformity of filler distribution. Apparently, these values directly depend on the bulk density (A three-roll mill (TRM)  was then used for fabrication of silicone composites based on graphene, CNT, or hybrid fillers with various G/CNT mass ratios and concentrations. In order to optimize the TRM processing parameters, several mixing trials were carried out using composite samples with 10% wt. of G/CNT (8:2) hybrid filler. Each trial was performed in either 3 or 6 steps and with varied gaps  between the rolls. The speed of rolls was fixed at 100 rpm. The quality of the obtained samples was compared through the measurement of their electrical conductivity and mechanical strength . In thisAt the next stage, composite samples loaded with 10, 15 and/or 20 wt.% of carbon filler  were fabricated by initial hand mixing and subsequent calendering with TRM processing parameters chosen at the previous step. The obtained mixtures were poured into molds and cured in an oven at 100 °C for 35 min.For illustration, the complete fabrication scheme is presented in The microstructure and morphology of G/CNT hybrid fillers and their silicone composites were observed using scanning electron microscopy (SEM) . For statistical purposes, 5 different areas were analyzed on each composite sample.The mechanical properties of G/CNT/PDMS composites were studied by using a computerized universal testing machine . The test samples (5 specimens of each composite type) were prepared according to the ASTM D638-Standard Test Method for Tensile Properties of Plastics. The relative measurement error did not exceed 5%.A Keithley 2400 digital multimeter  was used for high-precision resistance measurements by the four-point probe method. The dynamic electromechanical properties of the conductive composites were obtained by the electromechanical coupling test system, including a self-made stretching device and Keithley 2400 digital multimeter controlled by LabVIEW. In the electromechanical test, the gauge length was 16 mm with a loading speed of 40 mm/min. All electrical measurements were performed for 5 samples of each type, and the relative measurement error did not exceed 3%.2 for 10 days. Further, the cells with the culture medium were distributed over 24-well plates  with or without CNT/G/PDMS samples. After 4 days, the viability evaluation was performed through the MTT test. A 0.5 mg/mL solution of the MTT reagent in a cultural medium was added to the cells. After a 2 h incubation of cells with the MTT reagent, the medium was removed from the wells and replaced with 500 µl of DMSO. Afterwards, the plates were placed into a Synergy H1 Microplate Reader . The absorbance of samples was measured at the wavelengths λ = 570 nm and λ = 660 nm. Then, the absorbance value at 660 nm was subtracted from the absorbance value at 570 nm. The data were presented as percentages of the absorbance values in the control wells, which were taken as 100%. Data analysis was performed using GraphPad prism 7 software. Difference between groups was evaluated using Shapiro–Wilk normality test and t-test. Images of the culture were taken using a Nikon TS-100  microscope.In order to evaluate the biocompatibility of CNT/G/PDMS composites, a human neuroblastoma SH-SY5Y cell culture was used. Cells were cultured on 10.5 cm plates  in EMEM with the addition of 1% penicillin-streptomycin solution, 10% FBS, and 1 µM retinoic acid to induce neuronal differentiation. The cell culture was kept in an incubator  at 37 °C, 90% relative humidity, and 5% COw/w) fillers indicate a high uniformity of composite surfaces  demonstrated that the most uniform dispersion and homogeneity of carbon allotropes were achieved for the G/CNT mass ratio of 8:2. As can be seen from micrographs a, carbonsurfaces c, which surfaces d.The electrical and mechanical properties of the composite samples with various achievable concentrations  and G/CNT ratios were investigated. The obtained results are presented in As can be seen from the graph in To evaluate the durability and electrical stability of these composites under cyclic loadings, we also performed a series of stretching/releasing tests at 30% strain. According to the obtained results, the resistance of composite samples increased slightly during the initial cycles a and thep = 0.56)  b. Visual = 0.56) c. Thus, The present work aimed to produce biocompatible G/CNT/PDMS hybrid composites characterized by high stretchability and electrical conductivity. To achieve this aim, we developed a cost-effective, easy handling, non-toxic, and scalable technique based on aqueous solution blending and calendering processes. A key feature of the proposed approach is the use of a synergistic effect of non-covalent π-π stacking interactions in the G/CNT hybrid system. Our experimental studies of G/CNT/PDMS composites with various component ratios demonstrated that the synergistic effect of CNT and graphene interactions significantly improves their dispersion in the silicone matrix and contributes to the superior electrical and mechanical properties of hybrid composites compared to composites with either of these fillers alone. Moreover, the strongest synergistic effect was observed in silicone composites with the G/CNT ratio of 8:2. These composites at a filler concentration of 15 wt.% exhibited a low level of resistivity (1.61 Ohm·cm), a high level of elasticity , good durability (>1000 strain cycles), and prominent electrical stability under cyclic loading at 30% strain. The cytotoxicity studies also confirmed the good biocompatibility of G/CNT hybrid silicone composites, which demonstrates their vast potential for applications as stretchable conductors in wearable electronics and biomedical electronic devices.


In recent years, numerous studies have reported the development or exacerbation of sarcoidosis due to interferon therapy. However, ocular lesions rarely present as initial symptoms. Herein, we describe a rare case of interferon-α-induced sarcoidosis with uveitis as the initial symptom, and present a review of the relevant literature.This case involved a 62-year-old-Japanese woman with a history of a combination treatment of pegylated interferon-α-2a, ribavirin, and simeprevir, after which she developed granulomatous panuveitis. She was subsequently diagnosed with sarcoidosis following histological examination of skin biopsy specimens. In addition to reporting this case, we performed a literature review of 27 cases (24 case reports) of histopathologically diagnosed interferon-α-induced sarcoidosis published between January 2009 and November 2018.Among the reviewed cases, 23 (85.1%) cases developed skin lesions and 19 (70.1%) had lung lesions. Only three cases (11.1%) had accompanying eye lesions. Interferon-α therapy was discontinued in 16 cases (52.9%), and the majority exhibited improvement after systemic corticosteroid treatment. There are few reported cases of interferon-α-induced sarcoidosis with uveitis as the initial symptom. However, if uveitis develops during or after interferon-α treatment, it might represent an initial symptom of interferon-α-induced sarcoidosis, as observed in the present case. Interferon (IFN) is an important therapeutic agent for treating chronic hepatitis C. There have been an increasing number of reports on the development or exacerbation of sarcoidosis lesions in recent years due to IFN therapy. It is well established that cell-mediated immunity by T-helper type-1 (Th1) cells is involved in the development of sarcoidosis . HoweverHerein, we describe a case of IFN-α-induced sarcoidosis with uveitis as the initial symptom, and present a review of IFN-α and IFN-β-related case reports published between January 2009 and August 2018.The patient described in this report provided written consent for the publication of her data.A 62-year-old-Japanese woman presented with a 20-year history of hepatitis C. She did not report any significant family or psychosocial history. From October 2014 to March 2015, she was on the following three-drug combination regimen: pegylated IFN-α-2a (180 μg/week for 24 weeks), ribavirin, and simeprevir. Subsequently, combination therapy with sofosbuvir and ledipasvir was administered from July 2016 to September 2016. In November 2016, she presented with blurred vision in the right eye and was diagnosed with anterior uveitis. Her condition improved after the topical administration of corticosteroids at a nearby eye clinic. In January 2017, she developed panuveitis in the left eye. She was treated with topical corticosteroids but without any relief. Hence, she was referred to our hospital for the treatment of blurred vision. At her first visit, her best-corrected visual acuity was 20/20 in both eyes and her intraocular pressure was 16/15 mmHg. There was no inflammation in the anterior chamber, although a tent-like peripheral anterior synechia was observed in both eyes. Chorioretinal exudates and optic disc hyperemia were observed in the right eye, whereas vitreous opacity, retinal periphlebitis, chorioretinal exudates, and retinal hemorrhages were observed in the left eye ]; however, her soluble interleukin (IL)-2 receptor level was high [1214 U/mL ]. The patient tested positive for hepatitis C virus antibody, whereas she was negative for anti-human T-cell leukemia virus type 1 antibody; she also had a negative syphilis test and IFN-γ release assay (for tuberculosis). On chest computed tomography, swelling of the hilar and mediastinal lymph nodes, and numerous nodular lesions in the bilateral middle lung lobes and from the middle lung regions to the pleural surface were detected  of IFN-α-induced sarcoidosis Table  5–28] a–28 a5–28p = 0.094; t-test).The primary diseases of IFN-α-induced sarcoidosis were chronic hepatitis C in 24 cases, melanoma in 2, and erythrocytosis in 1 case. The male-to-female ratio was 4:5. The mean age at sarcoidosis onset was 51.4 ± 10.8 years . Twenty-three cases (85.1%) developed skin lesions and 19 70.1%) had lung lesions. Only three cases (11.1%) presented with accompanying eye lesions [0.1% had Our patient developed uveitis 25 months after initiating combination therapy with IFN-α and ribavirin to treat chronic hepatitis C. After 5 months, she was histologically diagnosed with sarcoidosis following a skin biopsy of the eruption on the right thigh. Uveitis was controlled with topical corticosteroid treatment.Sarcoidosis is a multisystemic granulomatous disease. In Japan, the frequency of pulmonary, eye, skin, or heart lesions is high . Th1 celIn contrast, ribavirin may suppress the Th2 immune response and activate the Th1 immune response. Although ribavirin-induced sarcoidosis has not been reported, combination therapy with IFN-α and ribavirin could increase sarcoidosis susceptibility. In addition, sarcoidosis has been reported to develop in patients with chronic hepatitis C without IFN-α treatment . Therefoet al. [While the most common symptom of IFN-α-induced sarcoidosis was skin lesion Table , there het al. . In otheet al. , 7, skinet al. [Few reports have outlined the treatment of IFN-induced sarcoid uveitis. One reported case of IFN-α-induced sarcoid uveitis with papillitis and macular edema showed improvement following sub-Tenon’s injection of methylprednisolone . Doychevet al.  reportedet al. . In our Our literature review has some limitations. First, we only verified articles that could be searched and read; thus, the actual number of articles may be greater. Second, we only included cases of histopathologically confirmed IFN-induced sarcoidosis and did not consider clinically diagnosed cases. Thus, the number of cases might have been underestimated.When using IFN treatment, it is necessary to monitor the onset of symptoms of sarcoidosis and systemic side effects of IFNs. If uveitis develops during or after IFN treatment, it may be the initial symptom of IFN-induced sarcoidosis. Ophthalmologists should suspect the development of sarcoidosis and conduct systemic investigations to diagnose sarcoidosis.


High frequent chromosome variations were also observed in the F2 hybrids and most of the analyzed recombinant inbred lines (RILs) at F14, derived from the cross of SHW-L1 with common wheat variety Chuanmai 32. Chromosome instability was associated with frequent univalency during meiotic metaphase I. The experiment on reciprocal crosses between SHW-L1 and Chuanmai 32 indicated that cytoplasm has not obvious effects on chromosome instability. An analysis on 48 F14 RILs revealed chromosome variation frequency was not associated with the Ph1 alleles from either SHW-L1 or Chuanmai 32, rejecting the hypothesis that chromosome instability was due to the Ph1 role of synthetic wheat. In the analyzed RILs, chromosome instability influences the phenotype uniformity, showing as obvious trait differences among plants within a RIL. However, the analyzed commercial varieties only containing ∼12.5% genomic components of synthetic wheat were chromosomally stable, indicating that chromosome instability caused by synthetic wheat can be effectively overcome by increasing the genetic background of common wheat.Primary allopolyploids are not only ideal materials to study species evolution, but also important bridges in incorporating genetic diversity of wild species into crops. Primary allopolyploids typically exhibit chromosome instability that a disadvantage trait in crop breeding. Newly synthesized hexaploid wheat has been widely used in wheat genetics and breeding studies. To better understand the cytological and genetic basis of chromosome instability, this study investigated the chromosomes of a large number of seeds derived from the synthetic wheat SHW-L1 and its hybrids with natural wheat. SHW-L1 exhibited persistent chromosome instability since we observed a high frequent chromosome variation  Allopolyploids are common in natural ecosystems . They arPrimary allopolyploids  often exhibit a high degree of genetic instability , globallTriticum aestivum L. AABBDD, 2n = 6x = 42) is an allohexaploid that arose from a polyploidization event involving tetraploid Triticum turgidum  and diploid Aegilops tauschii   . Modern  14, DD) . Howevertauschii . In a sytauschii . Despitetauschii  and the tauschii . SHWs hatauschii .SHW-L1 and hybrids with current wheat genotypes to systematically observe chromosome variation, examine the role of cytoplasm in reciprocal hybrids, and evaluate the effect of Ph1 (Pairing homoeologous 1) on chromosome stability. Although the present results did not offer clear answers, they provide new information in regard to adverse effects for genetic and breeding studies.However, chromosome instability in SHWs has attracted little attention compared to other breeding traits with previous investigations limited to studies chromosome numbers. Some genetic questions on chromosome instability remain to be answered. For example, what are the underlying cytological and genetic mechanisms and how such effects can be overcome in genetic and breeding studies? In this study, we used the synthetic wheat accession T. turgidum L. ssp. turgidum landrace AS2255  and Iranian A. tauschii ssp. tauschii accession AS60  derived from cross SHW-L1 × CM32. SHW-L1 was produced in 2001 (1) with 21 pairs of chromosomes was used as female in a cross with CM32. One hybrid plant was used to develop the F14 RILs and the SHW-L1 S1 plant was selfed to S14. The SHW-L1/CM32 RIL population was genotyped using wheat 660K SNP array  were determined as described by in situ hybridization (FISH) and genomic in situ hybridization (GISH) as previously described (10 (Triticum urartu), PI330488 (Aegilops speltoides), and AS2388 (A. tauschii), by a modified CTAB method  and Texas Red-5-dCTP , respectively. Genomic DNA of A. speltoides was used as a blocker. The latter steps, including hybridization, image gathering, image processing and re-hybridization were described in Slides were prepared for fluorescence escribed . Probes escribed , oligo-pibed .n = 42, 10 (14.3%) were not true euploids   had 2n ≠ 42, higher than the frequency observed in the SHW-L1 parent (48.6%) . Among these plants, 175 were examined by FISH and similarly, higher frequencies of structural variations were present among F2 seedlings of SHW-L1/CM32  and CM32/SHW-L1  compared to that in SHW-L1 (20.4%) (Six F21 pairs  were sel = 0.23) , indicat (48.6%)   . This in (20.4%) , and it In both SHW-L1 (A:B:D = 4:21:4) and its hybrids chromosome structural variations were biased toward the B genome  . Althoug14 SHW-L1/CM32 RILs was then analyzed. Since FISH data was not obtained the frequencies of “hidden aneuploids” (2n = 42) were undetermined and all plants with 2n = 42 were treated as euploids. Compared to SHW-L1 and F2 hybrids, chromosome instability was lower in the RILs  (Chromosome number variation in 48 Fthe RILs . Among 137 to 49 . The fre < 0.01) . Of them < 0.01)  and chro < 0.01) .The commercial derivatives Shumai 969 and Shumai 830 selected from second generation crosses of SHW-L1 with common wheat genotypes  were chrn = 42 plants of SHW-L1 , respectively. However, there was no difference in univalent number between the two hybrids . The univalents had a tendency to divide mitotically as laggards in anaphase/telophase I  was shown to be a candidate gene for Ph1 (Ph1 (inherited from its tetraploid wheat parent AS2255), we re-analyzed the 660 K SNP genotyping data of SHW-L1/CM32 RILs . Therefore, the result did not support that Ph1 solely promoted aneuploid formation in SHW-L1 and its hybrids. for Ph1 . To testM32 RILs . Accordiof 17.7% . HoweverTo check if the aneuploidy has an effect on phenotypic uniformity, we calculated the standard deviations of several traits in 48 SHW-L1/CM32 RILs and analyzed the relationship between the standard deviations and aneuploid frequencies. We found aneuploid frequencies were positively correlated with spike length at both Wenjiang 2016 and Beijing 2017, spikelet number at Wenjiang 2017, and plant height and rate of seed-setting at Beijing 2017 . These rPolyploids have a high tolerance to aneuploidy compared to diploids. This is well exemplified by the production of extensive series of aneuploids such as monosomics, trisomics, tetrasomics, and nullisomics in common wheat . HoweverObservations on univalent behavior in this study demonstrated that the wide variation in number between plants was associated with frequent univalency in meiosis. Univalents divide abnormally in meiosis and their derivative chromosomes are often not equally transmitted to daughter nuclei or lost in the formation of micronuclei. Univalents also have a tendency to break, especially at the centromeres . Chromos2 population derived from a cross between synthetic and natural Arabidopsis lines . In crosses our analyzed F14 lines with common wheat aneuploidy continued to influence the phenotype uniformity, showing as obvious trait differences among plants within a RIL. The phenotypic variation was correlated with the frequencies of aneuploids. These results indicated that PCI was the cause of “long-term segregation” in hybrids between synthetic and natural wheat.The achievement of varietal uniformity is an often-encountered problem in distant hybridization breeding compared to classical breeding. Such a phenomenon is described as “long-term segregation” although the underlying genetic mechanism remains poorly understood. In this study, we observed that a high frequency of The simple cross is a popular method to generate breeding and research populations such as RILs and DHs. Standard wheat varieties usually produce 1–3% aneuploid individuals . We usedThe original contributions presented in the study are included in the article/LBZ, DL, and MH conceived and designed the study. LBZ, DX, CF, SZ, and LH performed the experiments. SN, BJ, LQZ, and ZY supervised the study. LBZ prepared the manuscript. DL and MH edited the manuscript. All authors read and approved the final manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Multilayered graphene nanoplatelets (MLGs) were prepared from thermally expanded graphite flakes using an electrochemical technique. Morphological characterization of MLGs was performed using scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), Raman spectroscopy (RS), and the Brunauer–Emmett–Teller (BET) method. DGEBA-epoxy-based nanocomposites filled with synthesized MLGs were studied using Static Mechanical Loading (SML), Thermal Desorption Mass Spectroscopy (TDMS), Broad-Band Dielectric Spectroscopy (BDS), and Positron Annihilation Lifetime Spectroscopy (PALS). The mass loading of the MLGs in the nanocomposites was varied between 0.0, 0.1, 0.2, 0.5, and 1% in the case of the SML study and 0.0, 1.0, 2, and 5% for the other measurements. Enhancements in the compression strength and the Young’s modulus were obtained at extremely low loadings ( Since the discovery of graphene, significant progress has been achieved in the synthesis, research, and practical application of nanographene structures. Thus, graphene, which possesses unique properties required for commercial applications, such as high heat conductivity and electron conductivity, mechanical strength, chemical stability, and optical transparency, may be the most promising material for advanced nanoelectronics and optoelectronics ,2,3,4. TIt should be noted that the properties of graphene itself and its derivatives essentially depend on the synthesis technique used, the dimensions and number of the graphene’s atomic layers, and the concentration of vacancy, edge and other structural defects, which impact the device’s performance considerably. The basic properties of 2D graphene, multilayered graphene, and 3D graphene-based composites are essentially different; therefore, studying the physical and chemical properties of graphenic materials creates a firm basis of scientific knowledge for achieving controlled changes in the wide spectrum of parameters of nanostructured carbonic materials.Along with graphene-based composites filled with single- or double-layer particles, the functional properties of materials with multilayered graphene nanoparticles (MLGs) and their prospective applications have been studied intensively. In multilayer particles, the weak interaction of neighboring monoatomic graphene layers leads to a weak three-dimensionalization of physical properties. Electron scattering increases, while both heat and electrical conductivities decrease. Some parameters of polymer composites filled with highly purified thermally expanded graphite can exceed those of graphene-based composites ; howeverMLGs can possess basal surfaces of large size, whereas their lateral surface is of nano-sized thickness. The number of graphene layers can exceed one hundred. In MLG-filled polymer composites, the contacts between the neighboring particles significantly distort both the physical and chemical properties. Therefore, in order to prevent the aggregation of particles and their coming into contact within the host polymer matrix, it is most efficient to use particles with a basal plane size of no more than several tens of μm as a filler ,18. Due d values ,26,27,28 studied ,29,30.MLGs, along with high mechanical strength, possess a basic surface with high reactivity as well as a nanoscale lateral one, making them promising for applications as fillers in polymer composites to improve their thermal stability ,27,31,32The atomic composition of the thermal destruction products of epoxy composites at low MLG loadings has been determined previously using thermal desorption mass spectrometry. It was established that loading polymer with MLGs has no effect on the atomic composition of volatile destruction products, but it changes both the desorption intensity and the outputs of the products .It should be noted that both the mechanical parameters and the thermal stability of polymer composites are dependent on the surface reactivity of the filling particles, their spatial ordering in a host polymer matrix, and peculiarities of the interphase interaction. Hence, a character of the interface interaction and the molecular structure are key factors determining the performance of various polymer composites. The influence of the interface interaction on the polymer molecular structure has been studied using dielectric spectroscopy in many works. The frequency and concentration dependences of the dielectric permittivity  DGEBA-epoxy resin, with epoxy group content 5.21–5.50 mol/kg, Epoxy Equivalent Weight 182–192 g/mol was used as the host resin. Polyethylene-polyamine , Ukraine) was used as a curing agent. The structural formulas of the epoxy resin and hardeners can be found elsewhere .MLGs were obtained from thermal-expanded graphite flakes of Ukrainian production using the electrochemical technique described by Xia et al. .The SEM study shows the so-prepared low-dimension particles to be multilayered graphene nanoplatelets with in-plane dimensions of about 5 × 5 μm and 50 nm in thickness. Both surfaces of graphene particles have a complicated morphology. There are edge defects, surface curvatures, waviness, and mesovoids on the basal surfaces. The lateral surface contains about a hundred graphene layers and is characterized by a disordered structure and roughness .2/g was determined for neat MLGs by measuring the amount of physically adsorbed gaseous nitrogen from adsorption–desorption isotherms according to the standard Brunauer, Emmett, and Teller (BET) method [The specific surface value of ) method .The X-ray diffraction analysis shows that MLGs contain graphene sheets .−1, which belongs to the double degenerate mode −1. At the same time, analysis of the 2D band at ~2700 cm−1 in the Raman spectra is the most effective method to distinguish between graphene and graphite. The 2D band is due to scattering near the K-point of the Brillouin zone involving two phonons activated due to a double electronic resonance. The shape, position, and relative intensity of the 2D band in graphene differs significantly from the corresponding parameters of the 2D band in graphite. Analysis of both frequency position and shape of the 2D band in our Raman spectra  with the spectral resolution of 2 cm−1. The TE-cooled (−60 °C) CCD detector  was used to detect the spectra. The spectra were measured in so-called “backscattering” geometry.Raman spectra were excited with 457 nm single-longitudinal-mode solid-state lasers , with a power density on the samples of less than 105 W/cmMechanical parameters, namely the compressive strength An influence of MLGs filler on the composite’s thermal stability has been determined using a programmable thermal desorption technique combined with a mass spectroscopic detection via the single-pole mass-analyzer MX 7304A . Mass spectrometric analysis of positive charged atomic products was performed in the lsewhere .2 and a thickness of about (1–2) × 1 and the dielectric loss factor Dielectric properties of the neat resin and its composites filled with MLGs were obtained by measuring the complex relative dielectric permittivity found in ,65.2 scintillators  operated as the detectors of two different γ-quanta attributed to start (1274.6 keV) and stop (511.0 keV) of a positron lifetime. A 0.1 MBq 22Na positron source sealed by kapton foils (12.5 μm in thickness) was placed between two plates of the same sample. The time resolution of the device was determined to be 230 ps from the prompt curve of a 60Co source, at the temperature The positron annihilation spectra for investigated materials were obtained using the “Ortec”  positron lifetime system. “Scionix” modules equipped with two XP 2020Q photomultiplier tubes optically coupled with cylindrical BaF program .The static compression-loading stress , and 94 (C6H5OH) originate from epoxy chains. formula . Among tThe embedding of MLGs into epoxy does not vary the total number of lines. However, the interaction of polymer atoms with the graphene’s ASSs significantly affects the thermal decomposition intensity of the epoxy matrix and its thermal stability. The loading of epoxy with MLGs enhances the thermal stability of the composites. The latter is clearly manifested upon –7 times .Peculiarities of the MLG–epoxy interaction are clearly visible in the thermal desorption curves  calculatNormalized concentration dependences 2COH and C6H5COH Ed=RTCalculations of the activation energy for neat epoxy polymer provide It can be seen from thors of ,70 notedIt is known  that theA phenomenological model of heat-transfer processes at the interface is presented in the following. The heat flux In MLG–epoxy composites, the heat is transported through chains attached to ASSs. The phonon heat flux At high temperatures Hence, there is a temperature decrement ith moiety fixed on ASSs decreases, and its decomposition intensity As a result, the vibration energy of the vibrations of the surface site’s atoms is decreased by Since different The Here, the temperature ectively . One canThus, the thermal destruction data evidence that loading epoxy resin with multilayered graphene nanoparticles results in an increase in the composite’s thermal stability in the mass-concentration range of The frequency dependences of the real part .The concentration effect, which is clearly visible in both the frequency and temperature dependences of The concentration behavior of the composite dielectric permittivity can be described by the following relation:Frequency dependences of the dielectric loss factor tructure . Additio6 Hz, 6 Hz. It is remarkable that 6 Hz, the frequency behavior of In the wide frequency range of 12 % to 5%. b. On theironment ,72. 6 Hz, which is followed by a steep growth with increasing frequency in the range of 6 Hz for all the materials studied. Additionally, the 6 Hz. The identical behavior of the Another peculiarity of the dielectric losses is the minimum of r chains ,72,73.As temperature increases, several broad relaxation peaks become visible in the temperature dependences of At low temperatures −130 ≤ 500 Hz a,b. Bothlaxators ,74,75. B= 5% see d.The r chains ,75. The 6 Hz. These The most intensive relaxation losses in the neat epoxy and its MLG composites occurs at higher temperatures moieties ,75. The ases see , as predIt is remarkable that the dependence of requency . For freen C> 1% a. In coninterval b.The nonmonotonous Thus, the presence of unbound fragments of polymer chains and their attachment to the active surface sites of MLG particles, as well as the change of MLG content in the polymer matrix are the key factors affecting the degree of disorder in the polymer structure and the energy distribution of molecular dipoles.Using a set of e theory , at the pression :(11)ωβτavng C see . Since τDespite increasing The structural variations at The concentration dependence of free volume  formula :(15)fv=0equation :(16)τ3−1arameter .The free volume was found to decrease with increasing at C> 5% . Such beHowever, the structure’s constituents, such as epoxy chains, crosslinks, and nanosized defects (such as pores), are characterized by nonmonotonous alteration with MLG loading. In the concentration range 0 In the concentration range 1 vely see . The eleIn the concentration range 2  too see . The dieThus, the peculiarity observed in the macromolecular structure of the 2%-nanocomposite, which is related to the intensive formation of nanopores, reveals itself in overall physical characteristics such as thermal stability, destruction activation energy, and dielectric permittivity.The effect of low concentration loading of multilayered graphene particles on thermal stability, compressive strength and Young’s modulus, dielectric permittivity, dielectric losses, and the free volume of the epoxy composites were studied.At The compressive strength and the Young’s modulus are increased at extremely low loadings of At At Structural alteration in the 2% nanocomposite is related to a spontaneous increase in the density of nanovoids, which enhances the dielectric response of the nanocomposites to the external electric field.At 0%


The aim of this project was to develop an experiential programme which encouraged trainees to develop their own processes for mental resilience acting to mitigate difficult work and life environments.Doctors are at considerable risk of work-related stress, burnout and mental health problems, particularly trainees, many of whom are experiencing symptoms earlier in their career. The Thriving at Work Review, the British Medical Association and HEE all call for cultural and organizational change that works to prioritise, promote and enhance wellbeing by providing good working conditions and an atmosphere that encourages open discussion about mental health with access to appropriate support that destigmatises mental health.Across HEE-TV we identified that there were no regular wellbeing initiatives for trainees, and specifically no psychologist-facilitated Cognitive Behavioural Therapy-style sessions to enhance resilience. Six schools identified a specific need for HETV-targeted resources focused on enhancing trainee mental wellbeing.The current course has morning sessions that cover self-awareness, and afternoons are psychologist-facilitated sessions. The initial pilot was run for the School of Anaesthetics, and later offered to specialties with a General Medical Council-survey identified need. Multiple improved iterations of the course have been driven by detailed trainee feedback, including adding the psychology sessions to give trainees tools for self-help.We triangulated feedback from attendees at the sessions, nominated trainee representatives from all specialties across Thames Valley via the Trainee Advisory Committee (TAC), and HEE-TV quality assessors. Feedback from trainees who attended was almost universally positive. The Quality Committee noted improvement of trainee morale in Anaesthetics and direct improvement in aspects of the learner environment that would not have happened without this intervention. The TAC endorsed this as one of the measures to support trainees in difficult learner environments. They also recommended it be rolled out for all as a preventative measure as there can be a time lag before items appear on the Risk Registers and are officially recognized as requiring support. The biggest measure of success is that HEE-TV have agreed to fund these sessions ongoing.We learned that an iterative response to trainee feedback and careful co-ordination is key to successful engagement via the training programme directors who arrange regional training programmes. This, and making the SAT course free at the point of use, makes it easier for trainees to access this programme. In addition we will be including the trainee voice is shaping bespoke aspects of the day for each specialty.


Cladonia grayi into all nuclear rDNA copies of Saccharomyces cerevisiae, which lacks rDNA introns. Three intron-bearing yeast mutants were constructed with the intron inserted either in the 18S rRNA genes, the 25S rRNA genes, or in both. The mutants removed the introns correctly but had half the rDNA genes of the wildtype, grew 4.4–6 times slower, and were 40–1700 times more desiccation tolerant depending on intron position and number. Intracellular trehalose, a disaccharide implicated in desiccation tolerance, was detected at low concentration. Our data suggest that the interference of the splicing machinery with ribosome assembly leads to fewer ribosomes and proteins and to slow growth and increased desiccation tolerance in the yeast mutants. The relevance of these findings for slow growth and desiccation tolerance in lichens is discussed.We connect ribosome biogenesis to desiccation tolerance in lichens, widespread symbioses between specialized fungi (mycobionts) and unicellular phototrophs. We test whether the introns present in the nuclear ribosomal DNA of lichen mycobionts contribute to their anhydrobiosis. Self-splicing introns are found in the rDNA of several eukaryotic microorganisms, but most introns populating lichen rDNA are unable to self-splice, being either catalytically impaired group I introns, or spliceosomal introns ectopically present in rDNA. Although the mycobiont’s splicing machinery removes all introns from rRNA, Northern analysis indicates delayed post-transcriptional removal during rRNA processing, suggesting interference with ribosome assembly. To study the effects of lichen introns in a model system, we used CRISPR to introduce a spliceosomal rDNA intron from the lichen fungus  Cladonia grayi  that can cause direct damage to DNA, proteins, and lipids. Antioxidants and ROS-processing enzymes, common defenses against stress, are thought to protect also lichens from desiccation damage  may provin vitro . Plasmid pCAS (8.7 Kb) is a kanamycin/G418 shuttle vector carrying the gene for Cas9 and a generic guide RNA expression cassette  was used for transformations. E. coli was grown in LB medium  was added to the LB medium to 100 mg/L. The yeast strain used was S. cerevisiae YJ0  (The lichen mycobiont used for the Northern is the A2myc/ss . DH5α E.B medium  at 37°C.de2–101) , and wasde2–101)  at 30°C.C. grayi mycobiont liquid culture were seeded onto 47-mm diameter, 20 µm pore size Nylon filters. Filters were placed on MY plates and the mycobiont was grown for 1 month at room temperature. Dry weight of mycelia per filter was determined separately, two fresh filters  were removed from plates, wetted in RNAlater (Ambion), mycelia were scraped off, pooled, and total genomic RNA was extracted as described in C. grayi DNA a 109 bp fragment internal to group I intron-3  was transformed with each of the three plasmids and plated on LB-kanamycin medium. Colony PCR was first used to screen 10-20 transformants for the presence of the correct guide sequence. The primers used for colony PCR  sequence, or CgSSint1_LS7F and CgSSint1_LS7R for insertion into the 25S (LSU) sequence . RNA was quantified by NanoDrop (ThermoFisher Scientific) and quality was assessed by agarose gel electrophoresis. Using Superscript III RT (ThermoFisher Scientific), reverse transcription was performed at 50°C for 120 min in a 25 µl volume with 100 ng RNA and the reverse primer YrDNA18R  of four technical replicates on two adjacent columns of a 96-round-bottom well plate. To generate growth curves, an automatic plate reader (Tecan) was used to record the OD600 at 30°C every 15 min over a period of 96 h. The plate was shaken for 60 s before each measurement.Growth assays were done on YJ0, MSS2, MLS7, and Md. For each strain, a fresh agar plate culture was used to prepare a liquid suspension in YEPD with a concentration between 10600 between 0.1 and 0.25 and grown to 0.5 OD600. For each strain, duplicate 1 ml aliquots were pelleted in microfuge tubes. Pellets were resuspended in 1 ml of H2O, re-pelleted, and all the water was carefully removed with a pipette. One of the duplicate aliquots (designated as “undesiccated”) was immediately resuspended in 100 μl medium, serially diluted 10x, and three 5 μl replicates from each dilution were spotted on an agar plate. The other duplicate aliquot (“desiccated”) was laid against the sterile air flow in a laminar flow hood to dry for 24 h, resuspended in 100 µl medium, serially diluted and plated the same way as the undesiccated replicate. The number of survivors in each case was estimated by counting colonies at the highest countable dilutions and extrapolating to the number of viable cells in the starting suspension. Desiccation resistance was defined as the fraction of viable cells in the desiccated vs undesiccated sample. Three to six biological repeats were performed with each strain. P-values were calculated with a two-sided Student’s t-test.We modified in two ways the method by Budding frequency was measured in a hemocytometer with samples from mid-log phase cultures in YEPD liquid medium. For photography, diluted cell suspensions were plated on YEPD and incubated at 30°C. The YJ0 wildtype was photographed after overnight growth, the mutants after 48–72 h. A 1.5 × 1.5 square of agar was cut out of the plate, placed onto a microscope slide, and 10 µl water was placed on the surface followed by a cover slip.600 between 0.3 and 0.5. A volume containing 107 cells was harvested, cells were pelleted, resuspended in 2 ml ice-cold water and re-pelleted. Each pellet was resuspended in 250 µl of 0.25 M sodium carbonate, and the suspension was transferred to a 2-ml screwcap tube and stored a −80°C until trehalose extraction. Trehalose was extracted from cells by incubating the tightly sealed samples at 98°C for 4 h, with occasional mixing. Samples were stored at −20°C. For trehalase treatment, each 250 µl sample was mixed with 150 µl of 1M acetic acid and 600 µl 0.2 M sodium acetate, cell debris were pelleted, and 250 µl were removed from the top of the sample and stored at −20°C (untreated control). To the remaining 750 µl, 0.35 µl trehalase  were added for a final concentration of 2 units/ml, and reactions were incubated overnight at 37°C on a rotating wheel. After pelleting cell debris, the supernatant (750 µl) was transferred to a new tube to be assayed for glucose either immediately or, if convenient, after storage at −20°C, using the Glucose (GO) assay kit from Sigma Aldrich. For each assay, 220 µl of sample were mixed with 440 µl kit reagent in a 15-ml glass test tube, capped and incubated at 37°C for 30 min, and 440 µl of 6M sulfuric acid were added in a fume hood with a 1-ml glass pipette. Absorbance at 540 nm was measured in 1-ml plastic cuvettes. The untreated controls were used to measure background glucose, water samples were used as blanks and glucose standards to determine concentration.The method was essentially as described by in vivo splicing pattern of intron-3, a group I intron located in the 18S gene of the C. grayi lichen fungus  gene, of the 25S (LSU) gene, or both. The selected yeast insertion sites corresponded to two equences . Intron equences . The douequences  and sequequences . In addiequences  with a mhttps://people.biochem.umass.edu/fournierlab/snornadb/main.php). Although we do not demonstrate this directly here, the likelihood that snR38 inhibited Cas9 by binding to LS7 is supported (i) by the fact that the complementarity is in the snoRNA region that is meant to bind directly to rRNA to methylate it, (ii) by the successful insertion of the intron at the same position when using the LS7nc guide which is not complementary to snR38  failed. It was, however, successful when we used the LS7nc guide sequence (matching the template strand at the same location). This made us suspect that an endogenous yeast sequence serendipitously complementary to the LS7 guide RNA could have inhibited LS7-Cas9. A small nucleolar RNA (snoRNA) was considered a likely culprit. During yeast rRNA synthesis and ribosome assembly, a number of specific ∼100- to 1000-nucleotide long snoRNAs bind as ribonucleoprotein complexes to complementary sequences on the rRNA, leading to post-synthetic nucleotide modifications in those sequences  is in fato snR38 , and (iivs wildtype. Copy numbers in each of the single-intron mutants MSS2 and MLS7 decreased to about 53% of the YJ0 wildtype (Supplementary File S1). The qPCR data from the double-intron mutant Md were uninterpretable for unclear reasons. The intron-bearing mutants produced small, slow-growing colonies and their growth rates in liquid culture were 4–6 times slower than that of YJ0  survival ratios for MSS2, MLS7, and Md were 6.3 × 10−4 (42), 4.5 × 10−3 (300), and 2.6 × 10−2 (1700). The position and number of introns affects desiccation resistance, paralleling their effect on growth  observed when yeast grows slowly due to mutational or nutritional stress  mRNAs and RP synthesis. Competition between the highly expressed intron-rich RP genes, which use the most splicing factors (In yeast, ribosomal synthesis during unstressed growth is enabled by the activity of the TOR and PKA signal transduction pathways. Environmental stress signals repress TOR/PKA, which regulate the two arms of the ESR (S. cerevisiae growing in rich liquid media is ∼10−6. That means that in the bet-hedging process only one in a million cells has serendipitously activated, before desiccation, the ESR defenses needed to survive. In other yeast experiments that uncovered processes or molecules protecting cells from desiccation damage (6 fold relative to normal “unprepared” yeast as increasingly larger fractions of cells expressed their defenses before desiccation was applied.Extreme desiccation stress quickly deprives cells of water, the most basic ingredient for any life-sustaining process. This makes it critical for desiccation-defenses to be in place before the onset of desiccation. Most cells in an unstressed yeast population will not express the ESR and will die when desiccated. However, due to cell-to-cell stochasticity of transcriptional, translational, and post-translational network regulation (The intron-bearing mutants are 40–1700 times more resistant to desiccation than the wild-type strain, depending on intron position and number . The higin vitro and in vivo (While the slow growth of the yeast mutants is likely a direct, even if not linear, consequence of intron-mediated RiBi repression, the connection between the latter and increased desiccation tolerance is less clear. However, viewing the trehalose results within the context of rDNA introns sheds some light on the issue. The disaccharide trehalose is a primary anti-desiccation molecule in several anhydrobiotes . In yeas in vivo . TrehaloIntracellular trehalose concentration, naturally or experimentally induced, is generally proportional to desiccation resistance in intronless yeast . In our This indicates that, whether yeast grows slowly because of rDNA introns or because of depletion of fermentable carbon sources, factors other than inducible defenses like trehalose can elicit desiccation tolerance. We believe that data in the literature strongly suggest that a central component of those “other factors” is the constitutive reduction of cytoplasmic ribosome number. Unlike the fast-growing, single-celled yeast, lichens are slow-growing, differentiated multicellular networks of hyphae interwoven with consortia of different organisms. Their adaptation to extreme and repeated moisture oscillations must ensure survival of all or most component cells, not just of small subsets as is the case with bet hedging in yeast. We view the acquisition of large numbers of nonself-splicing rDNA introns as a powerful constitutive defense suppressing bet hedging across the entire lichen thallus. Such a constitutive defense based on ribosome reduction might also reduce the amounts of inducible defenses needed, like trehalose, polyols, and Hsps. As the introduction of just two nonself-splicing rDNA introns is quite disruptive to yeast, we imagine that the evolutionary insertion of many introns into mycobiont rDNA was gradual, providing time for selection to turn partial disruptions of RiBi and DNA replication into adaptations. The importance of constitutive stress-defenses in lichens has been also recognized by How could the degeneracy of lichen Group I introns have evolved? Despite lacking sequences needed for self-splicing, lichen group I introns appear still able to fold into tertiary structures resembling the original ones (In conclusion, the splicing pattern of a degenerate group I intron in a lichen fungus implies that lichen rDNA introns inhibit ribosome assembly. With yeast, we demonstrate that introduction into its rDNA of a lichen intron requiring spliceosomes for removal strongly enhances desiccation tolerance, also through the likely inhibition of ribosome assembly. We hypothesize that the numerous rDNA introns present in lichen fungi protect the entire mycelium in the thallus essentially by lowering ribosome content and holding the cytoplasm in a permanent state of “molecular frugality” which is less susceptible to desiccation damage. The evolution in lichens of a specific splicing machinery for the degenerate group I introns turned them into repressors of rRNA processing and ribosome assembly, transforming genetic parasites into a new tool against environmental stress; the ectopic rDNA location of spliceosomal introns turned them into repressors of RP synthesis to the same end. We think that evolutionarily, the spreading of special introns into the rDNA of lichen fungi was a watershed moment that helped lichens adapt to their permanent exposure to ever-changing environments. The price they paid was slow growth.Strains are available upon request. All data necessary for confirming the conclusions of the article are present within the article, figures, and tables. Supplementary File S1 describes the elaboration of the qPCR data. Supplementary File S2 describes the rDNA point mutations generated through CRISPR.


Graphene is a versatile compound with several outstanding properties, providing a combination of impressive surface area, high strength, thermal and electrical properties, with a wide array of functionalization possibilities. This review aims to present an introduction of graphene and presents a comprehensive up-to-date review of graphene as an antimicrobial and coating application in medicine and dentistry. Available articles on graphene for biomedical applications were reviewed from January 1957 to August 2020) using MEDLINE/PubMed, Web of Science, and ScienceDirect. The selected articles were included in this study. Extensive research on graphene in several fields exists. However, the available literature on graphene-based coatings in dentistry and medical implant technology is limited. Graphene exhibits high biocompatibility, corrosion prevention, antimicrobial properties to prevent the colonization of bacteria. Graphene coatings enhance adhesion of cells, osteogenic differentiation, and promote antibacterial activity to parts of titanium unaffected by the thermal treatment. Furthermore, the graphene layer can improve the surface properties of implants which can be used for biomedical applications. Hence, graphene and its derivatives may hold the key for the next revolution in dental and medical technology. Th2, h-BN, or quartz, using chemical vapor deposition, which allows direct deposition of high-quality graphene .,66.49,66g matrix .Furthermore, Jeyaseelan et al.  developeTissue engineering has emerged as an important approach to bone regeneration/substitution . FunctioSimilarly, Kang et al.  studied Recently, graphene-based bioactive glass is studied as a potential drug/growth factor carrier, which includes the composition–structure–drug delivery relationship and the functional effect on the tissue-stimulation properties ,88,89. WFinally, biodegradable composites have been used in various regeneration processes applications such as the regeneration of bones, cartilage, and soft tissues. Stepanova et al.  synthesiThe potential application of graphene for various biomedical applications is promising ,9, such There are various applications of metallic materials in medicine and dentistry, such as dental implants, orthopedic fixations, orthodontic, joint replacements, stents, endodontic files, and reamers . However−4 mm/year), whereas for untreated alloy: 45.25 mm/year in 3.5% NaCl solution  can be used to make biodegradable implants; however, its major drawbacks of difficult-to-control corrosion. Catt et al.  produced2+), increases the alkalinity in its surrounding environment, and induces cell differentiation and formation of mineralized tissue. However, the cement tends to possess poor mechanical properties, at risk of fracture due to poor strength and fracture toughness .,55.49,55s aureus  fabricatXanthomonas campestris pv. undulosa and pseudomonas and studied fungus were Fusarium oxysporum and Fusarium graminearum (−1. They mentioned that GO sheets intertwined the bacterial and fungal spores resulting in the local perturbation of their cell membrane, decreasing the bacterial membrane potential, and resulting in the leakage of electrolytes of fungal spores causing cell lysis (Chen et al.  studied minearum . It was ll lysis .The available literature shows that graphene-based coatings can improve the bioactivity of biomaterials, provide microbial- and corrosion-protection of implants, both in vitro and in vivo. Peri-implant infections causing peri-implantitis are among the most common reasons for implant loss and may be prevented by the coating of antimicrobial graphene. These additive properties of graphene can be modified by methods of functionalization. Graphene exhibits high biocompatibility, corrosion prevention, and antimicrobial properties to prevent the colonization of bacteria. Graphene coatings enhance adhesion of cells, osteogenic differentiation, and exhibit antibacterial activity to parts of Ti unaffected by the thermal treatment. Graphene-based materials are promising and may hold the key for the next material-based revolution for antimicrobial and coatings applications in dental and medical technology. More research is urged before clinical utilization will be a widespread reality.


The monolayer MoSe2-based PENG was fabricated by atmospheric pressure chemical vapor deposition techniques, which can generate a peak output of 35 mV and a power density of 42 mW m−2. The flexible PENG integrated on polyethylene terephthalate (PET) substrate can harvest energy generated by different parts of human body and exhibit great application prospects in wearable devices. The electrospinned PVA/MXene nanofiber-based humidity sensor with flexible PET substrate under the driven of monolayer MoSe2 PENG, shows high response of ∼40, fast response/recovery time of 0.9/6.3 s, low hysteresis of 1.8% and excellent repeatability. The self-powered flexible humidity sensor yields the capability of detecting human skin moisture and ambient humidity. This work provides a pathway to explore the high-performance humidity sensor integrated with PENG for the self-powered flexible electronic devices.Two-dimensional material has been widely investigated for potential applications in sensor and flexible electronics. In this work, a self-powered flexible humidity sensing device based on poly/TiThe online version contains supplementary material available at(10.1007/s40820-020-00580-5)  Humidity sensor has become increasingly indispensable in many areas such as industrial manufacture, medical health, and air quality monitoring, especially in the Internet of Things and flexible electronics . At pres−2, and the RH can be represented by the brightness of the LEDs driven by the TENG [3 concentration, flow rate, and frequency of exhaled gas [2, MoSe2, WTe2, WSe2, and MoTe2 have been theoretically predicted to exhibit piezoelectric property [2 showed piezoelectric effect and was applied to PENG [The latest technologies for collecting energy mainly include piezoelectricity , 13, trithe TENG . Tai et aled gas . Many neproperty . And it  to PENG , 29.3 and humidity, compared with untreated MXene [In recent years, two-dimensional (2D) nanomaterials such as graphene, metal oxides, transition metal dichalcogenides (TMDs), metal organic frameworks (MOFs), black phosphorus have attracted tremendous interests due to their excellent physical, chemical, and electrical properties. Especially, 2D nanomaterials have been employed in constructing high-performance sensors and flexible electronic devices , 31. In ed MXene . Due to ed MXene .3C2Tx (PVA/MXene) nanofibers film and monolayer molybdenum diselenide (MoSe2) piezoelectric nanogenerator was reported for the first time. The monolayer MoSe2 PENG was fabricated on a flexible polyethylene terephthalate (PET) substrate. The PVA/MXene nanofibers film was prepared on the interdigital electrodes (IDEs) as the humidity-sensitive material through electrospinning technology. The prepared self-powered piezoelectric humidity sensor (PEHS) was driven by the monolayer MoSe2 PENG via converting mechanical energy to electric energy. The self-powered PVA/MXene nanofibers film humidity sensor has a large response, fast response/recovery time, low hysteresis, and excellent repeatability. Furthermore, the humidity sensing mechanism of PVA/MXene sensor was explored.In this work, a self-powered flexible humidity sensor based on electrospinned poly /Ti3AlC2) and poly  (PVA) were from Shanghai Macklin Biochemical Technology.Hydrochloric acid  and lithium fluoride  were purchased from Sinopharm Chemical Reagent. Titanium aluminum carbide powders  was dispersed in a polypropylene plastic bottle with 6 M HCl solution (20 mL) and then was stirred for 5 min to ensure a fully dissolution. One gram of Ti3C2Tx mixed suspensions: Electrospinning is a typical fiber manufacturing process that can produce fibrous nanofilms with larger specific surface area [3C2Tx into PVA solution and magnetic stirring for about 0.5 h.Preparation of PVA/Tiace area , 36. One2 flake was employed for the fabrication of the PENG. Figure 2 prepared by atmospheric pressure chemical vapor deposition (APCVD) method was transferred to flexible PET substrate and exhibits irregular hexagon, followed by packaging with polydimethylsiloxane (PDMS) film. The white dots in the middle are the centers of the crystal nucleus. The monolayer MoSe2 on PET is sealed by PDMS film, which is isolated from the external environment to avoid the influence of environment humidity. Figure 2 flakes connected with Au electrodes along with armchair are performed. And the MoSe2 atomic orientation was identified by optical second harmonic generation (SHG) as in Fig. S1.Monolayer MoSe2, and the thickness is 0.3 mm. Electrospinning is widely used for preparing continuous nanofibers from viscoelastic fluids through electrostatic repulsion force between surface charges. Electrospinning nanofibers have the advantages of small porosity, high porosity, and large specific surface area, and are promising building blocks for the fabrication of sensors. The applied voltage between positive and negative poles was 18 kV, and the needle-to-collector distance was 15 cm. The flow rate is 0.3 mL h−1, and the duration is 0.5 h. Schematic of the experimental platform for humidity sensing measurement is shown in Fig. As shown in Fig. λ = 0.15418 nm) was used to investigate its crystal structure. The MoSe2 atomic layer was characterized by confocal Raman microscopy (Horiba HR–800) with a laser wavelength of 514 nm. Fourier transform infrared spectroscopy (FTIR) spectra were recorded using a PerkinElmer Spectrum Two FTIR spectrometer.The structure and surface morphology of the PVA/MXene nanofibers were characterized using scanning electron microscopy  and transmission electron microscope . The X-ray diffractometer  with CuKα radiation . The piezoelectric output of a MoSe2 PENG is related to the magnitude of the applied strain. Figure h is the thickness of the flexible substrate, R is the radius of curvature when the PENG was stretched. It can be found that the output voltage rises as the degree of the applied strain increases. The output voltage can reach 55 mV at strain of 0.6%, which is much higher than monolayer MoS2 PENG [2 slippage.The thickness of monolayer MoSetructure . Figure ectively . Figure −9 mW at a loading resistance of 9.2 MΩ and a power density of about 42 mW m−2, which is higher than other kinds of PENGs  region of PENG /S (%RH). RA and RD are the sensor resistance in the adsorption and desorption process of water molecules, and S is the sensor sensitivity. We investigated the hysteresis characteristic of PVA/MXene sensor versus RH, which shows the PVA/MXene humidity sensor has low hysteresis of 1.8%. The sensor has excellent humidity sensing performance, which is attributed to the humidity sensitivity of composite material. MXene has strong hydrophilicity and high electrical conductivity. The resistance of MXene film increases with the increase in humidity level, which may be the result of the increase in layer spacing caused by water molecules embedded in the MXene layers [The resistances of MXene, PVA, PVA/MXene sensors at different humidity levels are shown in Fig. e layers , 50. Thee layers , 52.Fig.S=VRH/Vmin, where the VRH is the output voltage of sensor at the target humidity and the Vmin is the minimum output voltage. The PVA sensor has the same voltage output in the humidity range of 11–52% because of its large resistance, and the voltage output of MXene sensor is close to 0 because of its small resistance. The experimental results are consistent with the previous analysis results; neither PVA nor MXene sensor is suitable to combine with PENG to detect humidity. The prepared self-powered PVA/MXene sensor holds high humidity response of ∼40. The corresponding equation is Y = 42.8402−0.4494X, and the regression coefficient (R2) is 0.9769. Figure −1) at a distance from the sensor (6 cm) and then leaves at the same speed. Table Figure 2 PENG has been proposed for the detection of humidity. The piezoelectric properties of monolayer layer MoSe2 were reported at first time. A high peak output of 35 mV can be obtained when the PENG was under 0.36% strain at a frequency of 0.5 Hz. And the flexible PENG can harvest energy and generate different output voltages by attaching to different parts of human body. The self-powered sensor was prepared by PVA/MXene composite nanofibers film and driven by the monolayer MoSe2 PENG to detect humidity by converting mechanical energy to electric energy, which has a larger response (40) and 40-fold higher than pure MXene. And the humidity sensor also shows fast response/recovery time of 0.9/6.3 s, low hysteresis of 1.8%, and stable repeatability. Moreover, the PVA/MXene nanofibers film was also used to prepare flexible humidity sensor on a PET flexible substrate and exhibited excellent performance on detecting human skin surface moisture.In this work, a self-powered humidity sensing device based on monolayer MoSeSupplementary file 1 (DOC 1440 kb)Supplementary file 2 (MP4 11087 kb)Supplementary file 3 (MP4 13225 kb)


Scorias spongiosa, as an edible fungus, has multiple health benefits. However, the effects of S. spongiosa on intestinal health are rarely explored. Hence, our study aims to elaborate on the influences of S. spongiosa polysaccharides (SSPs) on antioxidant, anti-inflammatory, and intestinal microflora in C57BL/6J mice. In the present study, 18 male mice were randomly distributed into three groups: (1) Control group (CON); (2) Low dose SSPs group (LSSP); (3) High dose SSPs group (HSSP). After 14-day administration, the jejunum and serum samples were collected for detection. The results showed that SSPs exert no effects on the growth performance of mice regardless of doses. Meanwhile, SSPs administration reduced the serum pro-inflammatory cytokines and elevated the anti-inflammatory cytokines. Moreover, the antioxidant capacity was elevated by SSPs administration, as evidenced by the increased contents of T-AOC, GSH-Px, and the decreased content of MDA. Mechanistically, the administration of SSPs enhanced the protein abundances of p-Nrf2, Keap1, and HO-1 in mice. The results of 16S rDNA demonstrated that the microbial community and composition were altered by SSPs administration. To summarize, SSPs benefit intestinal health in C57BL/6J mice via a mechanism that involves elevating antioxidant and anti-inflammatory activities and regulating intestinal microbiota. The intestinal microbiota is considered to be a dynamic organ that plays an important role in maintaining host health, which includes Firmicutes, Bacteroidetes, Actinobacteria, Fusobacteria, and so on . The micScorias spongiosa, which belongs to the genus Scorias Fr., (1825), was discovered by He in 2011 and is considered as a new record species after a pure culture experiment and internal transcribed spacer (ITS) sequence analysis (Scorias spongiosa polysaccharides (SSPs), a chemical bioactive compound, were secreted through various stimulating agents, such as surfactants and organic solvents  and were conducted following the academy’s animal experiment guidelines.Male C57BL/6J mice  were purchased from Chengdu Dashuo Laboratory Animal. Animals were housed in groups of six mice with a temperature (22°C ± 3°C), humidity (55% ± 15%), and lighting (12 h light/dark cycle) with via anesthesia using pentobarbital sodium to collect the samples for subsequent determination.In a 14-day experiment, 18 mice were randomly distributed into three treatment groups with six individuals per group: (1) Control group (CON), gavaged with saline once a day; (2) Low dose SSPs group (LSSP), gavaged with 200 uL SSPs once a day; (3) High dose SSPs group (HSSP), gavaged with 400 uL SSPs once a day. At the end of the experiment, all mice were sacrificed The interleukin-1β (IL-1β), IL-6, IL-10, tumor necrosis factor-α (TNF-α), and interferon-gamma (IFN-γ) in serum and glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), malondialdehyde (MDA), and total antioxidant capacity (T-AOC) contents were determined using spectrophotometric kits according to the manufacturer’s instructions .Frozen jejunal samples (approximately 0.1 g) were homogenized using 1 ml RIPA buffer. Following this, ultrasonication was performed to break the cells. The lysates were then centrifuged at 10,000 rcf for 20 min at 4°C. The proteins in the supernatant were diluted with 4× Laemmli sample buffer  and denatured in a 98°C metal bath for 10 min. Equal amounts of samples were then subjected to SDS-PAGE, and the abundances of phospho-nuclear factor-E2-related factor 2 , heme oxygenase-1 , Kelch-like ECH-associated protein 1  and GAPDH  proteins were assessed by western blot using the indicated antibodies. The expression level of GAPDH was assessed to ensure equal protein sample loading.Samples of the mice’s intestinal contents were collected immediately after sacrifice. The cetyltrimethylammonium bromide/sodium dodecyl sulfate extraction method was employed to obtain the total DNA from the intestinal content. The extracted DNA was subjected to 16S amplification using primers designed to incorporate both the Illumina adapters and a sample barcode sequence, allowing directional sequencing that covers the variable region V4 (primers: 515 F [GTGCCAGCMGCCGCGGTAA] and 806 R [GGACTACHVGGGTWTCTAAT]). Phusion® High-Fidelity PCR Master Mix  was used for the PCR reactions.Sequencing libraries were produced using an Ion Plus Fragment Library Kit 48 rxns  according to the manufacturer’s recommendations. Libraries were sequenced on an Ion S5TM XL platform and 400/600 bp single-end reads were generated. The data were based on sequenced reads and operational taxonomic units (OTUs). UPARSE software (v7.0.1001) was used to carry out the analysis. Sequences that have similarities ≥97% are regarded as the same OTUs. The Silva database was employed to annotate the taxonomic information based on the Mothur algorithm .1p < 0.05 was considered to imply statistical difference.All results were analyzed statistically by one-way analysis of variance (ANOVA) tests using IBM SPSS Statistics version 20.0  followed by Tukey’s multiple comparison test. The data are expressed in the form of mean ± standard deviation (SD) and p > 0.05), indicating that the growth performance of mice was not affected by SSPs administration.To determine whether the SSPs administration influences the growth performance of mice, we assessed the body weight (BW) at the beginning and end of the experiment. As shown in p < 0.01). Moreover, the pro-inflammatory cytokines including IL-1β (p < 0.01).To verify the anti-inflammatory capacity of SSPs, some inflammatory cytokines were determined by ELISA. The anti-inflammatory cytokines IL-10  increaseng IL-1β , IL-6  the jejunal protein abundances of Keap1, HO-1, and p-Nrf2 in C57BL/6J mice. Subsequently, we detected the biomarkers of membrane lipid peroxidation and protein oxidative injury. Compared with the control group, SSPs administration decreased the content of MDA and increased the content of GSH-Px and T-AOC.From the results of p < 0.05) the Chao1 index, dominance index and observed_otus index of bacteria in mice. Meanwhile, HSSPs decreased (p < 0.05) the Shannon index, Simpson index and pielou_e index of bacteria in mice. In addition, the PCoA analysis revealed that microbial community was significantly altered by HSSPs administration, with an evident separation (p < 0.05) compared with the control group.As shown in The bacterial composition was analyzed at different taxonomic levels . At the premna microphylla turcz leaves polysaccharides (pPMTLs) showed high anti-inflammation activity via various pathways including antimicrobial peptides (AMPs) expression pathway, immunodeficiency (IMD) pathway, target of rapamycin (TOR) pathway and intestinal autophagy pathway (Morchella importuna polysaccharides (MIPs) attenuate CCl4-induced hepatic inflammatory injury via decreasing pro-inflammatory cytokine production through inhibiting the TLR4/NF-κB signaling pathway  fruiting bodies or sclerotia tissues and can be used for food or medicine . Polysac pathway . Moreove pathway . However pathway , were doMDA, as an indirect indicator of the degree of tissue peroxidation, can promote the infiltration of inflammatory cells and even promote the expression of myeloperoxidase (MPO), while SOD, as an antioxidant enzyme, has the opposite effect . GSH-Px via regulating the antioxidant factor production through activating the Keap1-Nrf2-ARE signaling pathway.Oxidative stress refers to that when the body is stimulated, the content of reactive oxygen species (ROS) or reactive nitrogen species (RNS) free radicals exceeds the range that can be cleared by itself, resulting in the imbalance of redox balance and tissue damage, and eventually lead to a series of diseases. In response to oxidative stress, body-self-expression produces a series of endogenous antioxidant factors, including antioxidant molecules and detoxifying enzymes. Among them, the Keap1-Nrf2-ARE signaling pathway plays a crucial role in mediating endogenous antioxidant factors. The results of western blotting indicated that the SSPs administration enhanced the protein level of p-Nrf2, Keap1, and HO-1, implying that SSPs possess a strong anti-oxidant capacity Firmicutes and Bacteroidota which is dominated in the gut microbiota were altered by SSPs administration. These species matter as they play a role in the body’s energy-balance mechanism as they affect energy transformation, nutrient absorption, and glucose metabolism. The Firmicutes/Bacteroidetes ratio is raised in the groups treated with SSPs. These results suggested that SSPs may regulate intestinal diversity and composition to benefit gut health.The human gastrointestinal (GI) tract is a huge and complex micro-ecosystem, hosting trillions of microorganisms including but not limited to bacteria, fungi, and viruses . The intTaken together, our study showed that SSPs are instrumental in intestinal health by enhancing the anti-inflammation and anti-oxidative capacity. Furthermore, the diversity and composition of intestinal microbiota were enriched by SSPs administration. Our findings provided a deep understanding of the benefit of polysaccharides from edible fungi as bioactive materials to intestinal health.The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found at: NCBI BioProject—PRJNA808190.The animal study was reviewed and approved by the Animal Care and Use Committee of the Sichuan Provincial People’s Hospital .YX, WP, and YW conceived and designed the experiments. ZZ, HF, JT, and YX conducted the experiments. YX and YW wrote the paper. YX, YC, and JZ analyzed the data. All authors contributed to the article and approved the submitted version.This work was financially supported by the China Agriculture Research System of MOF and MARA (CARS-20).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Interfacial characteristics of polymer nanocomposites represent a crucial aspect to understand their global properties and to evaluate the interaction between nanofillers and matrix. In this work we used a molecular dynamics (MD) approach to characterize the interfacial region at the atomistic scale of graphene-based polymer nanocomposites. Three different polymer matrixes were considered, polylactic acid (PLA), polypropylene (PP) and epoxy resin (EPO), which were reinforced with three types of graphene fillers: pristine graphene (G), graphene oxide (GO) and reduced graphene oxide (rGO). In particular, the compatibility of the nanofillers in polymer matrixes were evaluated in terms of the interaction energy, while the interfacial thermal resistance (Kapitza resistance) between matrices and fillers was calculated with a nonequilibrium molecular dynamics (NEMD) method. Results showed that the oxidation degree plays an important role on the studied properties of the interfacial region. In particular, it was observed that the Kapitza resistance is decreased in the oxidized graphene (GO and rGO), while interaction energy depended on the polarity of the polymer matrix molecules and the contribution of the Coulombic component. In the last decade, graphene (G) has attracted the attention of both scientists and industry stakeholders for its extraordinary mechanical, electrical and thermal properties ,2,3,4, mk) and graphene–graphene contact resistance. By comparing analytical and experimental results these authors demonstrated that the interfacial thermal properties play a relevant role in the global thermal conductivity of a nanocomposite. Similarly, Bigdeli and Fasano [Molecular dynamics (MD) simulations have given light to the study and knowledge of the interfacial properties between matrix and filler, which represent key aspects to evaluate the dispersibility and binding capacity of nanofillers in polymer matrix and to understand the effective global characteristic of a nanocomposite. Regarding thermal properties, for example, Su et al.  developed Fasano  and Mohad Fasano  demonstrd Fasano  evaluated Fasano  calculatd Fasano  and Mortd Fasano  found thIn this study, molecular models of nanocomposites based on different polymer matrices  and graphene fillers (pristine and oxidized) were developed, with the aim of studying some of their interfacial properties. The interface energy between matrix and filler was first evaluated to obtain an estimation of the compatibility, and then the interfacial thermal resistance across the interface (Kapitza resistance) was calculated to quantify the effect of the oxidation degree on interfacial thermal transport. iK, iH, iV, and iF are constants; r is the distance between atoms; b is the bond length; θ and φ are the bond angles of bending and torsion; iq is the partial charge of a given atom; and iA and iB are the van de Waals parameters. The value of these parameters were taken as defined in the COMPASS force field according to the work developed by Sun [Three types of nanocomposites were modeled with atomistic detail by considering three different polymer matrices: two thermoplastic polymers, Polylactic acid (PLA) and Polypropylene (PP), and a variety of an epoxy thermoset resin (EPO). The chemical structure of generic PLA and PP chains are shown in d by Sun .Three types of graphene fillers  were employed to assess the effect of different surface functionalization of the graphene on the interfacial properties (interaction energy and Kapitza resistance) of polymer nanocomposites. In The nanocomposite full atom models  were geniE) can be calculated considering the energy of the composite and the energy of the isolated components:totE, polymerE and fillerE are the potential energies of the composite, polymer and filler, respectively. The potential energy has contributions of bonds, angles, dihedrals, van der Waals and Coulombic interactions (short- and long-range), but not kinetic energy contribution. Indeed, E could represent the total energy or even only a component of the energy . After the system equilibration in the isothermal–isobaric (NPT) ensemble, the model is finally minimized with the conjugate gradient method using convergence criterions of 0.0 kcal/mol and 1 × 10−10 kcal/mol·Å for energy and force. Then, the energy of the composite (totE), filler (fillerE) and matrix (matrixE) were evaluated, pointing out the electrostatic and dispersive contributions. Each partial contribution was calculated, deleting alternatively the filler and the matrix, which allows for extracting the partial potential energy of each phase at its configurational equilibrium with the other phase, neglecting the interaction contribution between them. The interaction energy defines the energy of the system  implied in the interaction between the polymer matrix and the graphene filler. The interaction energy (ΔKR), is a measure of the resistance of the interface to thermal flow. This property is measured from the atomistic models using a transient approach or nonequilibrium molecular dynamics (NEMD). Initially, the simulation box was entirely equilibrated to the equilibrium temperature of 300 K. Once the whole system (polymer + filler) was equilibrated at this temperature, the filler (graphene) was heated to 400 K . During the heating process of the graphene filler, the temperature of the polymer was kept constant at 300 K using a second thermostat. Finally, when the filler reached the temperature of 400 K, the thermostats were switched off and the system was allowed to relax in the microcanonical NVE ensemble. During this relaxation process, the temperature of the filler and polymer were monitored, from which the temperature difference over time (ΔT(t)) was calculated and plotted ) can be fitted using an exponential decay:The temperature difference (ΔThis expression can be linearized by taking logarithms as follows:KR) is associated with the relaxation time constant τ as stated in the next expression: A is the filler surface area and C the filler heat capacity, which were assumed constant for all the models at ambient conditions [The Kapitza resistance  and v(t) are the velocities of each atom at initial time and time t, respectively, and ω is the frequency. The DOS spectra of graphene fillers and polymers were obtained by monitoring the velocity autocorrelation function of the corresponding atoms. The velocity autocorrelation functions were acquired along 5 ps of trajectory with ten repetitions for statistical average.The phonon density of states (DOS) of a system describes the proportion of states that are occupied by the system at each energy in the range of modes of vibrations of elastic arrangements of atoms or molecules. The phonons play an important role in the thermal conductivity across the interface between two phases or materials, so the study of this type of vibration mode gives a deep understanding of the influence of atomistic properties on a property such as this ,27. The E) and van der Waals (VdWE) or Coulomb (CoulE) components. In the case of PLA and EPO composite models, the interaction energy between matrix and filler increased in the order G < rGO < GO (The interaction energy could be considered as an indicator of the compatibility between two components (in this case between the polymer and the graphene fillers). A negative value of interaction energy means that the interaction produces a release of energy and thus a favorable compatibility between the filler and polymer. The results, which are expressed in terms of average and standard deviation values obtained from three replicas for each system studied, are summarized in rGO < GO , or, in KR)  , which aterature ,17. Consterature , the DOSTo explain the results of Kapitza resistance, the phonon DOS spectra of graphene fillers and polymers, either in the composite or the neat state, were obtained from the atomic velocity autocorrelation functions after their Fourier transformation . It can Heat carriers of high frequency are important to thermal transport across interfaces ,30,31. AThe interaction energy of the three different polymer matrices with the graphene fillers depended on the polarity of the polymer, due to the different contribution of the Coulombic component. Thus, it was observed that the interaction energy increases in the order graphene < rGO < GO for polar polymers such as polylactic acid (PLA) and epoxy resin (EPO), whereas in the case of polypropylene, the functionalization did not affect sensibly its interaction with graphene fillers, due to the negligible Coulombic contribution. These results gave a relevant insight about the matrices–filler compatibility and how it is affected by the different functionalizations considered.The Kapitza resistance (RK) exhibited the same behavior/tendency in the three polymers, graphene > rGO ≈ GO. It was observed that the presence of functional groups in the graphene, in the form of oxidation (hydroxyl and oxirane groups) increases the thermal conductivity, which was associated with the appearance of high frequency phonon vibrations in the oxidized graphene fillers, GO and rGO.Molecular dynamics (MD) models were developed in order to study the properties of the polymer–graphene fillers interface considering of three different polymer matrices, polylactic acid (PLA), polypropylene (PP) and epoxy resin (EPO) with different graphene derivatives: pristine graphene (G), graphene oxide (GO) and reduced graphene oxide (rGO). From these models, two types of interfacial properties were calculated: the interaction energy and the interfacial thermal resistance (Kapitza resistance). The main conclusions derived from these analyses follow:


Noticeably, BN-doped graphene supporting a single metal atom  activates the N2 molecule with a red shift in the N–N stretching frequency . This red shift is corroborated by an increase in the N–N bond length (1.23 Å from 1.09 Å) and charge transfer to an N2 molecule from the catalyst.Using the periodic density functional theory–based methodology, we propose a potential catalytic system for dinitrogen activation, viz., single metal atoms  supported on graphene-based sheets. Graphene-based sheets show an excellent potential toward the anchoring of single atoms on them  with adsorption energies ranging between 1.048 and 10.893 eV. Factors such as defects and BN doping are noted to enhance the adsorption energies of single metal atoms on the support. The adsorption of a dinitrogen molecule on metal atom–anchored graphene-based supports is seen to be highly favorable, ranging between 0.620 and 2.278 eV. The adsorption is driven through a direct hybridization between the  Though the availability of dinitrogen (N2) is abundant in air, it requires high energy for fixation and activation owing to its existence of inert triple bonds between nitrogen atoms. Currently, the well-known Haber–Bosch process invented more than a century ago is used for converting dinitrogen (N2) in the atmosphere into NH3 in the presence of the iron catalyst at an extreme temperature (500°C) and pressure (200 atm)  . The eneemission . Neverthrganisms . Researc V atoms , yet the2 activation on potential inorganic metal clusters (2) activation using infrared multiphoton dissociation (IR-MPD) on neutral Ru clusters. Similarly, −1 on solid Lin (2 < n < 8) clusters, particularly the Li8 metal cluster showing an exothermic trend in splitting the N–N bond completely. In the midst of metal clusters for evaluating N2 activation reaction, Al clusters play a remarkable role. Previously, Jarrold et al. observed low energy barriers for N2 activation on Al44 and Al100 clusters at high temperatures using concerted experimental and theoretical techniques  methodology   represents the energy of the optimized single transition-metal cluster  and the designed surface supports. E(M) and E(system) represent the energy of a single metal and surface support, respectively.The ground state geometries of single transition-metal clusters  are adsorbed on the above-mentioned supports and the complexes optimized. The adsorption energy of Mo, V, and Fe on these supports is calculated as follows:2 molecule is adsorbed on these active metal clusters  on graphene-based surface supports. A parallel mode of adsorption  is used as this mode has been found to be more effective as compared to the vertical mode. In the vertical mode, only one N atom in the N2 molecule interacts with the metal leading to weak activation  represents the energy of the dissociated N2 molecule on the catalytic systems. E(N2) and E(M--system) represent the energy of the N2 molecule and metal-adsorbed various surface supports, respectively. Nudged elastic band (NEB) calculations were performed toward prediction of energy barrier of N2 activation on metal-adsorbed BN-doped graphene-based substrates.The dissociated adsorption energy of the NGraphene-based 2D materials which act as an electron reservoir are used as the support for adsorbing the single atom cluster  which increases the catalytic activity of the metal center. The five graphene-based supports are designed, viz., 1) pristine graphene (50 carbon atoms), 2) defective graphene (49 carbon atoms with a single vacancy at the center), 3) BN-doped graphene (4% heteroatom doping in which boron and nitrogen are substituted instead of carbon in the pristine graphene), 4) BNC-ring graphene (8% heteroatom doping), and 5) BN-ring graphene (12% heteroatom doping). All these graphene-based supports are designed and optimized to the local minima as shown in Thus, we have tried to establish the relative reactivity of single atom clusters  chemisorbed on the above-mentioned surfaces. The optimized structure of adsorption of Mo (gray), Fe (red), and V (purple) on various surface supports is shown in 2 activation. The total density of states and projected density of states of a single metal atom  on graphene-based supports are shown in The carbon–metal (C–M) interatomic distance of Mo, Fe, and V on pristine graphene, defective graphene, BN-doped graphene, and BNC-ring graphene is 2.200–2.213, 2.069–2.080, and 2.147–2.170 Å;1.932–1.956, 1.766–1.768, and 1.863–1.873 Å; 2.145–2.261, 2.012–2.473, and 2.079–2.192 Å; and 2.072–2.305, 1.947–2.148, and 2.072–2.306 Å, respectively. The boron–metal (B–M) interatomic distance of Mo, Fe, and V on BN-doped graphene, BNC-ring graphene, and BN-ring graphene is 2.258, 2.303, and 2.215 Å; 2.279–2.28, 2.106–2.218, and 2.279–2.28 Å; and 2.216–2.219, 2.063–2.124, and 2.17–2.227 Å, respectively. The nitrogen–metal (N–M) interatomic distance of Mo, Fe, and V on BN-doped graphene, BNC-ring graphene, and BN-ring graphene is 2.211, 1.861, and 2.172 Å; 2.224–2.226, 2.01–2.225, and 2.224–2.226 Å; and 2.267–2.273, 2.073–2.197, and 2.204–2.226 Å, respectively. The interatomic distances and adsorption energies of Mo, Fe, and V on various graphene-based supports are shown in 2 on a single metal atom  on pristine graphene, defective graphene, BN-doped graphene, BNC-ring graphene, and BN-ring graphene are 1.739, 1.334, and 1.996 eV; 0.887, 0.620, and 0.628 eV; 1.844, 2.278, and 1.988 eV; 1.870, 1.544, and 2.116 eV; and 1.868, 1.510, and 2.258 eV, respectively. Comparatively, the adsorption energies of N2 on a single metal atom  on the defective graphene support are less compared to those on the rest of the support. Moreover, there is an eventual increase in adsorption energies of N2 on V on supports  due to more vacant d orbitals , which is vice versa in Fe  on the same supports. The optimized structure of adsorption of N2 on a single metal atom  on various surface supports is shown in The adsorption energies of N2 on a single metal atom  on pristine graphene, defective graphene, BN-doped graphene, and BNC-ring graphene is 2.228–2.313, 2.077–2.162, and 2.190–2.264 Å; 1.946–2.013, 1.777–1.847, and 1.871–1.925 Å; 2.194–2.257, 2.096–2.144, and 2.133–2.234 Å; and 2.111–2.319, 2.004–2.172, and 2.048–2.241 Å, respectively. The boron–metal (B–M) interatomic distance of N2 on a single metal atom  on BN-doped graphene, BNC-ring graphene, and BN-ring graphene is 2.313, 2.18, and 2.319 Å; 2.316–2.407, 2.219–2.222, and 2.303–2.342 Å; and 2.244–2.41, 2.141–2.216, and 2.256–2.371 Å, respectively. The nitrogen–metal (Ndoped–M) interatomic distance of N2 on a single metal atom  on BN-doped graphene, BNC-ring graphene, and BN-ring graphene is 2.32, 2.202, and 2.223 Å; 2.239–2.328, 2.165–2.173, and 2.23–2.242 Å; and 2.274–2.341, 2.083–2.234, and 2.264–2.297 Å, respectively.The carbon–metal (C–M) interatomic distance of Nad–M) interatomic distance of N2 on a single metal atom  on pristine graphene, defective graphene, BN-doped graphene, BNC-ring graphene, and BN-ring graphene is 2.039–2.117, 1.92–1.923, and 1.911–1.994 Å; 2.22–2.221, 1.964–2.078, and 2.161–2.218 Å; 2.027–2.091, 1.902–1.907, and 1.918–2 Å; 2–2.057, 1.889–1.89, and 1.908–1.979 Å; and 2–2.068, 1.9, and 1.869–1.928 Å, respectively. The interatomic distances and adsorption energy of N2 on a single metal atom  on various substrate systems are shown in 2 on a single metal atom  on the graphene-based support are shown in The nitrogen–metal  on the graphene-based support, we investigated the spectral range of 1,300–2,300 cm−1, which covers the typical frequencies of the different N2 species known to exist on transition-metal surfaces. The stretching frequency of the unbound N2 molecule is attributed to 2,330 cm−1, and the N–N bond length is 1.09 Å  on pristine graphene, defective graphene, BN-doped graphene, BNC-ring graphene, and BN-ring graphene are 1.20 Å (1735 cm−1), 1.18 Å (1823 cm−1), and 1.21 Å ; 1.17 Å (1907 cm−1), 1.16 Å (2009 cm−1), and 1.16 Å (1997 cm−1); 1.20 Å (1701 cm−1), 1.19 Å (1802 cm−1), and 1.20 Å (1711 cm−1); 1.21 Å , 1.19 Å (1777 cm−1), and 1.21 Å ; and 1.21 Å , 1.19 Å (1796 cm−1), and 1.23 Å , respectively.To probe the stretching frequency of the adsorbed Ns 1.09 Å . The N–N2 activation are listed in 2 molecule adsorbed on Mo, Fe, and V on various graphene supports are shown in The Bader charge analysis  and the sp2 orbitals of unsaturated carbon atoms of various designed graphene-based supports. The catalytic performance of a single metal atom  on graphene-supported catalysts is explored for the activation of molecular nitrogen. The adsorption energies of the nitrogen molecule on a graphene-supported single atom cluster  range between 0.620 and 2.278 eV, which is attributed to the interacting environment of the active metal centered on the support and the p orbital of adsorbed molecular nitrogen. Bader charge and density of states analyses corroborate an enhanced hybridization between the d states of the single metal atoms  and adsorbed molecular nitrogen for activation. The N–N stretching frequencies are found which are considerably red-shifted ranging from 2009 cm−1 (1.16 Å) to 1,597 cm−1 (1.23 Å) compared to that of the unbound N2 molecule ). Thus, from the results, we understood that even a single metal atom  with functionalized (BN-doped) graphene supports can highlight the excellent potential for nitrogen activation.In this work, we explore the potential of various graphene-based 2D materials, viz., pristine, defective, BN-doped graphene, etc., as a support for a single atom cluster . These graphene-based supports show excellent potential toward the anchoring of a single atom cluster  with adsorption energies ranging between 1.048 and 10.893 eV. Thus, the adsorption energies vary substantially with respect to the graphene-based supports, viz., pristine, defective, BN doped, etc. This is attributed to the size and nature of hybridization between the