We present detailed Raman studies of graphene deposited on gallium nitride nanowires with different variations in height. Our results indicate that different density and height of nanowires impact graphene properties such as roughness, strain, and carrier concentration as well as density and type of induced defects. Tracing the manifestation of those interactions is important for the application of novel heterostructures. A detailed analysis of Raman spectra of graphene deposited on different nanowire substrates shows that bigger differences in nanowires height increase graphene strain, while a higher number of nanowires in contact with graphene locally reduces the strain. Moreover, the value of graphene carrier concentration is found to be correlated with the density of nanowires in contact with graphene. The lowest concentration of defects is observed for graphene deposited on nanowires with the lowest density. The contact between graphene and densely arranged nanowires leads to a large density of vacancies. On the other hand, grain boundaries are the main type of defects in graphene on rarely distributed nanowires. Our results also show modification of graphene carrier concentration and strain by different types of defects present in graphene. Therefore, the nanowire substrate is promising not only for strain and carrier concentration engineering but also for defect engineering. The combination of excellent electrical and mechanical properties with interesting physical phenomena occurring in two-dimensional structures makes graphene an interesting experimental material to study –3. ImporA novel approach of graphene-based nanostructures are van der Waals heterostructures in which graphene is transferred onto another material with a different morphology and electronic properties . HoweverSystems containing graphene on nanowires have been used in solar cells to increase their efficiency. In particular, it has been shown that the application of nanowires in solar cells decreases light reflection by scattering of light in between nanowires –8. NanowOne of the most common experimental techniques for studying properties of graphene is Raman spectroscopy . Non-invIn this paper, we present detailed statistical studies of Raman spectra of graphene deposited on gallium nitride nanowires (GaN NWs) with different variations in height. The electric field induced in GaN predicted by theoretical calculations could reach 5 MV/cm . This is−2. However, they formed clusters containing several merged NWs. In the second sample (N100) the height of the NWs varied by approx.100 nm, from 300–400 nm, and the density of NWs was approx. 400 NWs·µm−2. In the third sample (N500) the average density of NWs was similar to that in the first sample – approx. 120 NWs·µm−2. However, in this sample, two distinct groups of NWs were observed – approx. 80% of them were 1 μm in height while approx. 20% reached 1.5 μm.Monolayer graphene was grown by chemical vapour deposition (CVD) on a copper foil with methane gas as the precursor . Next, gThe samples were studied by scanning electron microscopy (SEM) using a SU8230 Hitachi microscope equipped with an in-lens secondary electron detector at 5 kV electron beam voltage. The Raman spectra were collected by using a T64000 Horiba Jobin-Yvon spectrometer with a Nd:YAG laser operating at 532 nm wavelength as the excitation source, and with an objective with a magnification of 100× that allowed to obtain a spatial resolution of approx. 300 nm. The laser power was reduced to 3 mW in order to reduce the heating effect. The micro-Raman maps were collected with 100 nm steps with a few square micrometres of mapping area for each sample. The spectra were calibrated by using a reference sample of high-quality silicon.The morphology of graphene deposited on NWs with different variations in height is presented in The large cracks visible in the graphene layer are caused by the transfer process. Graphene on NWs with equal height is smooth . Small w−1 and 2D band at 2680 cm−1) and both defect bands (D band at 1345 cm−1 and D’ band at 1620 cm−1) are observed . The dependence of graphene strain on the 2D band energy shift is described by 2D is the Grüneisen parameter, Δε is a value of strain, and the value of 2D band energy for unstrained graphene  was reported to be 2677.6 cm−1 [where γ7.6 cm−1 . Positiv7.6 cm−1 ,36–39. T7.6 cm−1 –41. Ther7.6 cm−1 ,42.−1) is observed for the N500 sample, while the highest standard deviation of 2D band energy (2.7 cm−1) is observed for the N100 sample  and the lowest for the N500 sample (1.7). Surprisingly, the value of R2DG suggests that the carrier concentration in the N500 sample is the highest of all the investigated samples, which disagrees with the conclusions obtained from the analysis of the G and 2D band energy values and FWHM.The intensity ratio of 2D and G graphene bands in monolayer graphene has been reported to be negatively correlated with carrier concentration . A higheR2DG on the strain and carrier concentration was performed by the analysis of 2D and G band FWHM. As discussed before, 2D band FWHM is positively correlated with the graphene strain, while G band FWHM is negatively correlated with the carrier concentration [R2DG ratio and 2D band FWHM is observed  and described by The G band is generated by the scattering on iTO or iLO phonons near the Γ point of the Brillouin zone. For the presence of D band, the resonant scattering on the iTO phonon near the K point of the Brillouin zone and the defect are necessary. Consequently, the intensity of the G band is proportional to the laser spot area while the intensity of the D band depends on the number of defects in the excited area. Therefore, the density of defects l is the excitation light wavelength. In order to visualize the distribution of defect density on the graphene surface, we performed spatial and statistical analysis of the intensity ratios of the G and D bands  is correlated with the low density of defects. However, a similar number of defects in the N0 and N100 samples remains unclear. Although the density of defects is similar for N0 and N100 samples, a different distribution of the RGD ratio, which reflects defect density on the surface, is observed  depends on defect density and parameters describing the perturbation introduced by the defects in the crystal lattice. These perturbation parameters depend on the type of defect and are different for the D and D’ bands. Thus, the intensity ratio between D and D’ bands characterize the type of defects in graphene [RDD’ ratio equals to 3.5 is characteristic of grain boundaries, five is characteristic of multiple vacancies, seven corresponds to single vacancies, while 13 is observed for sp3 hybridisation defects [RGD ratio, a strong modulation of RDD’ by the NW substrate is observed on the 2D maps  while the grain boundaries are the main defects in the N500 sample . At least 98% of all types of defects in the N500 sample are grain boundaries, which is a higher value than the obtained for vacancy contribution in N0 and N100 samples . The standard deviation of the RDD’ ratio for the main maximum in the N500 sample is equal to 0.6, which is lower than that for N0 and N100 samples . Therefore, the interaction between graphene and rarely distributed NWs is more homogenous than that with densely arranged NWs. The largest number of different types of defects  are observed in the N100 sample, which confirms that graphene interacts with densely distributed NWs in a variety of ways.The intensity of both defect bands D and D’  in these two samples is unclear. From the discussion above, the dependence between the density of NWs supporting graphene and the types of defects is nontrivial. Our results suggest that in graphene deposited on rarely arranged NWs, the grain boundaries are the most dominant type of defects. Densely arranged nanowire substrates introduce vacancies in the graphene deposited on them. Furthermore, the presence of a large number of vacancies in the N0 and N100 samples together with gating by the nanowire substrate could be responsible for increasing the carrier concentration, which is also confirmed by other studies [As discussed before, the analysis of the 2D band energy and  studies ,48. In tTherefore, high differences in NW height and low density of supporting points decrease the observed density of defects and highlight grain boundary defects omnipresent in the graphene layers. The contact with NWs of lower differences in height and higher density of supporting points creates more vacancies and increases their density on the surface. Moreover, graphene strain and carrier concentration can be locally modified by the different density of defects and their types. Thus, further studies on the influence of NWs supporting graphene and graphene strain, carrier concentration, and defects performed with higher resolution are essential.RGD and RDD’ ratios showed that the density of defects in graphene was affected by the nanowire substrate. Our results suggest that NWs supporting graphene with low differences in height introduce vacancies in the graphene. Increasing distances between NWs decreased the density of defects and exposed a larger number of grain boundaries omnipresent in any graphene layer. Furthermore, the vacancies could locally increase the graphene carrier concentration and tensile strain in the N0 and N100 samples together with the nanowire substrate. Thus, the density of NWs supporting graphene substrate and their differences in height impacted graphene carrier concentration and strain. It is, therefore, possible to consider the use of NW substrates for defect engineering in graphene and probably in other 2D materials.We transferred graphene onto GaN NWs with 0, 100, and 500 nm variations in height and studied their properties by SEM and Raman spectroscopy. Graphene on NWs with variations in height was rippled and pierced by the highest NWs. A detailed analysis of the Raman spectra showed that differences in NW height as well as NW density strongly impact graphene strain and carrier concentration. The highest strain value was observed for the sample with the highest differences in height . Unexpectedly, the strain in the graphene on NWs with equal height had a tensile character while the strain in the graphene on NWs with non-equal height had a compressive character. Analyses of G band energy and G band FWHM showed a positive correlation between the density of NWs under graphene and the value of its carrier concentration. In contradiction to previous reports, we found that the intensity ratio between 2D and G bands is correlated with the graphene strain rather than with its carrier concentration. Furthermore, analyses of


Industrial preparation of graphene has been a research hotspot in recent years. Finding an economical and practical carbon source and reducing the cost of production and instrument is significant in industrial graphene production. Coal is a common carbon source. Efficient improvement and utilization in the cleaning of coal has recently been a popular research area. In this study, we developed a set of graphene preparation methods based on Anhui Huainan’s low-rank gas coal (HNGC). Using self-built experimental equipment, benzene precursor was prepared from HNGC and used as carbon source to realize graphene growth. The quality of the graphene was characterized by a high-resolution microscope and Raman spectrometer. This study provides a new idea and method for the preparation of low-rank coal-based graphene. Coal mining destroys groundwater resources and exacerbates water shortage in water-deficient areas. Coal mining leads to the emission of waste gas , which harms the atmospheric environment. In addition, there are few inorganic substances in coal, mainly water and minerals, which reduce the quality and utilization value of coal. Therefore, the development of converting coal into clean and efficient materials enhances the utilization value of coal and provides new ideas for tapping the potential industrial value in materials. Among them, the preparation of graphene from coal is a popular research area in this field in recent years [Graphene, as a new type of two-dimensional material, has attracted wide attention from the scientific research community because of its unique crystal structure and electronic properties, which make it have unique electrical, mechanical and thermal properties. Graphene has a good application prospect in various physical and engineering fields. Therefore, obtaining cheap and controllable technology for the industrial preparation of graphene has been widely pursued by the scientific research community. In this area, obtaining a clean and pure carbon source from cheap and common matter to realize graphene is one of the most popular research areas in recent years. Coal is a kind of carbon-containing organic matter with polycyclic aromatic hydrocarbon as the main structural unit, which exists widely in nature. As a big coal country, China is rich in coal resources. Anhui, as a big coal province, has huge coal reserves, and Huainan gas coal is the main coal resource. However, the conversion efficiency of coal is low because the coal is still limited in practical applications of burning. Nowadays, coal, as the main fossil energy in China, will inevitably pollute the environment during processing and utilization. When coal is burned, most sulfur is oxidized to sulfur dioxide , gasification and liquefaction of coal ,8. The uGenerally, from the basic principle of chemical vapor deposition (CVD) growth of graphene, polycrystalline copper foil is applied as an economical and efficient catalyst to reduce the decomposition barrier of carbon precursors, and the most common carbon precursor is gaseous methane ,12,13,14However, methane is a flammable and explosive gas produced during the coal mining process, which makes the current process complicated and increases the cost of fabrication. In recent years, in order to realize the large-scale industrial production of graphene, more and more new precursor carbon sources have appeared. It is found that graphene can be prepared via some solid and liquid precursor molecules ,16,17. TOur study will explore the technology of producing graphene from gas coal to graphene based on the technical route process: from gas coal to coal tar to benzene. That is,Pyrolyzing gas coal in high temperature and oxygen-free environment to produce coal tar;Separating crude benzene and other fractions by distillation;Refining industrial-grade benzene as carbon source to grow graphene.In view of the mature industrial foundation of the preparation of refined benzene, we focused on the CVD growth of monolayer graphene with benzene as carbon source. For the graphene samples obtained, we used an optical microscope, a scanning electron microscope and Raman spectroscopy to characterize the graphene. In addition, we examined the number of layers and the morphology features of graphene grown under different growth conditions, such as benzene flow rates and growth temperature, in order to explore the possibility of the low-temperature preparation of the graphene in the future.Coal tar is pyrolyzed from collected gas coal at high temperature under oxygen-free conditions, and then crude benzene is obtained by distillation, and refined benzene with high concentration is obtained by refining. The method of producing graphene with refined benzene as carbon source is as follows: introduce 50 sccm hydrogen gas and keep the tube furnace at 1060 °C for three hours. The main purpose of heating for 3 h with added hydrogen is to remove the oxide on the surface of copper foil, and to make the surface smooth by the reconstruction of atoms within the annealing process. After that, reduce the temperature to 500 °C and reduce the flow rate of hydrogen to 30 sccm , meanwhile introduce benzene for 40 min. The flow rate of benzene can be controlled by adjusting the trimming valve in order to avoid the influence and waste caused by volatilization of benzene when the substrate is heated up. Generally, after reaching the growth temperature, the needle valve should be adjusted properly to make benzene fill in the furnace tube at a required rate continuously, which makes the pressure in the tube maintain at the required vacuum condition. After finished the sequence, the ball valve and trimming valve are required to be closed, then the temperature of the tube is cooled down to room temperature naturally. After that, graphene is transferred to silicon oxide by standard wet transfer process.We found that the growth condition of preparing monolayer and multilayer graphene from benzene at high temperature generally has a large range. Since benzene is liquid, it is hard to control the content of benzene with a traditional flow controller process, so the amount of benzene used is supposed to be accurately adjusted by using a trimming valve. The content of benzene can be controlled and monitored by a vacuum gauge. We control the carbon flux in the growth process by different benzene partial pressures in order to study the graphene quality at different benzene partial pressure. We found that at the partial pressure of benzene of 1.1 Pa, the optical microscopic results show the nearly completely monolayer graphene with a regular and uniform surface. From the image of optical microscopy a, the hiIn order to examine the details of the graphene quality, we used the scanning electron microscope (SEM) to show the detailed morphology and the material quality of graphene, as shown in In order to realize the possibility of growing graphene at a low temperature in future, we examined the number of layers and the morphologic features of graphene grown with different growth conditions, such as benzene flow rates and growth temperature. In our experiment, while the partial pressure of hydrogen with a flow rate of 30 sccm was 55.6 Pa, the partial pressure of benzene ranged from 17.3 Pa to 1.1 Pa, and the growth temperature ranged from 1060 °C to 500 °C. When the partial pressure of benzene is 17.3 Pa but the growth temperature is still kept at 1060 °C, it is observed under an optical microscope a that thWhile in order to decrease the amount of benzene, when the partial pressure of benzene is reduced to 4.4 Pa, the quality of the material is obviously decreased and there are some bi-layer/multi-layer graphene structures with the obvious brightness at the edge because of the large thickness from the SEM image e althougThe way to grow graphene at high temperature is to break the benzene ring into carbon atoms and obtain a large area of graphene through the catalytic reaction at copper substrate. However, the benzene ring can directly remove hydrogen atoms and then re-bonds each other to generate monolayer graphene at a low temperature. Following this process, industrial production costs can be greatly reduced. We also prepared graphene at a temperature of 500 °C and the partial pressure of benzene of 1.1 Pa. Under the optical microscope, it was observed that the prepared graphene was very regular g but theIn this study, the coal samples analyzed were from the No. 13-1 coal seam of the Upper Shihezi Formation in Huainan coalfield, northern China. In order to ensure the freshness of the samples, groove sampling was carried out in the underground working face. In the laboratory, vitrified coal strips (removing gangue) were obtained by a manual separation method and they were ground and sieved until the particle size reached 200 mesh. The ground powder sample was then dried and stored in a sealed bag for testing.daf, %), hydrogen , nitrogen , and sulfur  were the average of two parallel samples, and the oxygen  content was obtained by difference subtraction. According to the GB/T212-2008 standard, the moisture , ash  and volatile matter  of HNGC samples were determined. The experimental results are presented in The ultimate analysis of Huainan gas coal (HNGC) samples was carried out on a Vario EL element analyzer, German EA Company . The contents of carbon , D peak (1350 cm−1) and 2D peak (2680 cm−1) are caused by defects or disorders that can be used to preliminarily determine the number of graphene layers, the stacking order between layers and the defect and impurity density, respectively. The light transmittance of the optical microscope and the interference of the substrate can be used to directly characterize the graphene layers transferred to the silicon oxide substrate. In addition, the overall roughness and uniformity of graphene can be preliminarily characterized. The scanning electron microscope can be used to characterize the surface morphology details of graphene [The method of obtaining high-temperature dry distillation coal tar by high-temperature pyrolysis of coal annealing 200 g HNGC to 1000 °C by using a high-temperature pyrolysis program analyzer. The instrument for the preparing of graphene using the CVD method from coal consists of three parts: a tubular furnace of HF-Kejing with a vacuum gauge monitoring the pressure inside, connected to a liquid/gas flow rate control system and a vacuum pump unit  by chemical vapor deposition with different benzene flow rates; the relatively uniform monolayer graphene structure was also obtained by low temperature CVD. Our results show that in future industrial applications, replacing the traditional gas carbon source of methane gas from the Huainan coal with the liquid benzene can produce high-quality monolayer graphene with an economic preparation cost, and has the characteristics of high efficiency and good safety.Our results also found that the layers and structure of graphene made with CVD process are highly related to the flow rate of benzene. We are working on quantifying the relationship and trying to control the structure and layers. We believe, in future, this method can be used for convenient, flexible and economic growth control of monolayer/multi-layer graphene, which can lay a foundation for the exploration and development of new functions of coal.


DCTN1 encodes the largest subunit of the dynactin complex. Dynactin associates with the microtubule-based motor cytoplasmic dynein and is required for dynein-mediated long-distance retrograde transport. Perry disease-linked missense mutations  reside within the CAP-Gly domain and impair the microtubule-binding abilities of DCTN1. However, molecular mechanisms by which such DCTN1 mutations cause TDP-43 proteinopathy remain unclear. We found that DCTN1 bound to TDP-43. Biochemical analysis using a panel of truncated mutants revealed that the DCTN1 CAP-Gly-basic supradomain, dynactin domain, and C-terminal region interacted with TDP-43, preferentially through its C-terminal region. Remarkably, the p.G71A mutation affected the TDP-43-interacting ability of DCTN1. Overexpression of DCTN1G71A, the dynactin-domain fragment, or C-terminal fragment, but not the CAP-Gly-basic fragment, induced cytoplasmic mislocalization and aggregation of TDP-43, suggesting functional modularity among TDP-43-interacting domains of DCTN1. We thus identified DCTN1 as a new player in TDP-43 cytoplasmic-nuclear transport, and showed that dysregulation of DCTN1-TDP-43 interactions triggers mislocalization and aggregation of TDP-43, thus providing insights into the pathological mechanisms of Perry disease and other TDP-43 proteinopathies.A common pathological hallmark of several neurodegenerative diseases, including amyotrophic lateral sclerosis, is cytoplasmic mislocalization and aggregation of nuclear RNA-binding protein TDP-43. Perry disease, which displays inherited atypical parkinsonism, is a type of TDP-43 proteinopathy. The causative gene  Glued is the largest component of dynactin [Dynactin, a megadalton-sized multimeric complex, acts as an essential cofactor of the microtubule-based motor cytoplasmic dynein-1  in many eukaryotic cells . Dynactidynactin ,3,4. DCTdynactin ,6. The odynactin ,9,10.Interactions of dynein and dynactin, including those of DCTN1, with various partner proteins have been identified through the efforts of many investigators. DCTN1 directly interacts with microtubules in a dynein-independent manner and accumulates at microtubule plus-ends ,12. DCTNDynein also binds to Huntingtin (HTT), the causative protein for Huntington’s disease (HD), while DCTN1 binds to HTT-associated protein 1 (HAP1) ,23,24. TTARDBP gene, is a ubiquitously expressed RNA-binding protein; it is predominantly nuclear but undergoes nucleocytoplasmic shuttling. Physiologically, TDP-43 coordinates multiple aspects of RNA metabolism, for example, regulating gene transcription and RNA splicing in the nucleus, and RNA transport and protein translation in the cytoplasm and axoplasm [Transactive response DNA-binding protein 43 (TDP-43), encoded by the axoplasm ,29. TDP-axoplasm . Evidencaxoplasm ,32. PrLDaxoplasm . PrLD/IDaxoplasm . Recent ALS10) and sporadic ALS; expression of mutant TDP-43 induces neural apoptosis [In 2006, almost simultaneously, two research groups reported TDP-43 to be a major ubiquitinated protein component of insoluble cytoplasmic aggregates in degenerating neurons found in patients with frontotemporal dementia (FTD) and a fatal motor neuron disease, amyotrophic lateral sclerosis (ALS) ,36. Thespoptosis ,39. The poptosis ,32,39. Tpoptosis ,41. HoweDCTN1, closely apposed mutations in its CAP-Gly domain cause two distinct neurodegenerative diseases  have been identified so far -derived neurons, thereby recapitulating several cellular phenotypes found in the brain neurons of Perry disease patients.The first goal of this study was to characterize the biochemical relationship between DCTN1 and TDP-43. To investigate the molecular basis of Perry disease, we have recently been searching for DCTN1-interacting proteins involved in neurodegeneration. However, no novel, promising candidates for such DCTN1 interactors were found. We thus refocused on the findings that, in our immunohistochemical studies, both TDP-43 proteinopathy and dynactin aggregates were detected in all of the Perry disease post-mortem brains examined ,48,50. Rrevealed . These fTo examine whether DCTN1 interacted with TDP-43, we performed coimmunoprecipitation between endogenous Dctn1 and Tdp-43 proteins in murine brains. We prepared whole brain extracts from embryonic day (E) 16.5 mice. An anti-DCTN1 antibody was used to immunoprecipitate Dctn1 from the brain cell lysates, and an anti-TDP-43 antibody was used to detect Tdp-43 in the immunoprecipitates through Western blotting. Results of our coimmunoprecipitation experiment revealed that the endogenous Dctn1 and Tdp-43 interacted with each other in vivo C.To confirm the potential interactions between DCTN1 and TDP-43, we next performed coimmunoprecipitation between tagged DCTN1 and TDP-43 proteins in cultured cells. cDNAs encoding the full-length human DCTN1 C-terminally tagged with 2× myc epitope (DCTN1-myc) or with monomeric green fluorescent protein (DCTN1-mGFP) and/or full-length human TDP-43 N-terminally tagged with mCherry (monomeric red fluorescent protein (mRFP) derivative; mCherry-TDP-43) were transfected into monkey fibroblast COS-7 cells. DCTN1-myc or DCTN1-mGFP were immunoprecipitated using an anti-myc or anti-GFP antibody, respectively, from the cell lysates D,E. In bWe sought to map the TDP-43-interacting domains of DCTN1. A series of truncated mutants of DCTN1-myc were made and subjected to coimmunoprecipitation assays. Aiming at high-precision domain dissection, bioinformatics analyses were performed on the amino acid sequence of DCTN1 ) using online resources, including SMART-EMBL Heidelberg , MulticoBased on these results, we divided the DCTN1-coding sequence to create expression plasmids encoding seven truncated mutant forms of DCTN1-myc, as illustrated in These truncated mutant DCTN1-myc and mCherry-tagged full-length TDP-43 were cotransfected into COS-7 cells, and their interactions were examined by coimmunoprecipitation. TDP-43 was detected in the anti-myc immunoprecipitates from cells expressing full-length DCTN1 or several mutant forms; the CAP-Gly-basic supradomain-containing fragment (D∆2), dynactin domain (D∆4), CC2-containing region (D∆5), and extreme C-terminal region (D∆6) of DCTN1 interacted with TDP-43  or the PrLD-containing C-terminal fragment  and the TDP-43-CTF were sufficient for interactions between DCTN1 and TDP-43 E. AltogeG71A and DCTN1G59S mutants with TDP-43 was significantly higher than those of wild-type DCTN1 . On the other hand, the interactions of DCTN1F52L with TDP-43 were not significantly different from those of wild-type DCTN1 , which was consistent with clinical observations that symptoms of patients with the DCTN1 p.F52L mutation are less severe than with the other mutation types [Two different groups of missense mutations within the DCTN1 CAP-Gly domain are known to cause Perry disease, accompanying TDP-43 proteinopathy, or HMN7B, with no detectable TDP-43 proteinopathy ,48,50. Won types . Taken tWe next examined interactions between wild-type DCTN1 and a defective NLS-carrying mutant TDP-43 (TDP-43-∆NLS). As previously reported , contrarE. coli and purified using glutathione Sepharose beads (We examined whether DCTN1 bound to TDP-43 in vitro. The DCTN1-coding sequence was divided into two parts: to express the NTF composed of the CAP-Gly-basic and CC1 domains (D∆8), or the CTF composed of the dynactin and CC2 domains and extreme C-terminal region (D∆9) , less severe levels of DCTN1 protein aggregates were found in cells coexpressing DCTN1G59S and TDP-43, as compared with the cells coexpressing DCTN1G71A and TDP-43  prevented the cytoplasmic-nuclear transport of TDP-43, and thereby caused dramatic mislocalization and aggregation of TDP-43, revealing that DCTN1 physiologically regulated TDP-43 localization and aggregation, possibly via multivalent interactions between DCTN1 and TDP-43. The results of expression of truncated DCTN1 (D∆4–6) suggest that the disruption of regulated multivalent DCTN1-TDP-43 interactions drive aberrant aggregation of the two proteins.G71A or D∆4 with TDP-43, significant levels of TDP-43 cytoplasmic mislocalization were induced  [Many researchers, including the current authors, have speculated that a direct relationship between DCTN1 aggregation and TDP-43 aggregation was unlikely, and that TDP-43 proteinopathy might be a secondary event that emerges long after dynactin aggregation, mainly for two reasons. First, colocalizations of dynactin components, DCTN1, DCTN2/p50, and DCTN4/p62, with TDP-43 were detected in only a small number of protein inclusions, according to autopsy studies ,50 and cd below) .G71A or D∆4–6) and wild-type TDP-43, the incidence of aggregation of DCTN1 alone, without TDP-43 aggregation, was unexpectedly low. However, coaggregation (or coexistence within the same cells) of DCTN1 and TDP-43, or less frequently, aggregation of TDP-43 alone, was detected in around 79%–85% of the cells  became localized predominantly in the nucleus D. On theytoplasm . We therDrosophila RNA-binding protein Egalitarian (Egl), although Egl is not thought to be evolutionally conserved [mRNA localization underlies precise spatiotemporal control of protein translation in polarized cells, such as neurons, and especially in axons; the dysfunction of this machinery has been implicated in various neurodegenerative diseases ,86. The onserved . It remaonserved ,6. We foonserved ,11. ThusFurthermore, as well as interacting with dynein, DCTN1 interacts with the anterograde microtubule motor kinesins, to coordinate bidirectional transport ,90. DCTNElectron microscopic studies reveal that the N-terminal region of DCTN1, composed of the CAP-Gly-basic, CC1, dynactin, and CC2 domains form a flexible extension called the projecting arm, while its C-terminal region is buried in the shoulder of the dynactin complex ,91. We hAccording to our bioinformatics analysis, five putative IDRs were found in DCTN1. IDRs have been implicated in protein phase separation-driven aggregation . InteresTaken together, the present study showed that DCTN1 can form aggregates of DCTN1 and TDP-43, preferentially via the dynactin domain and C-terminal region, which act as TDP-43-binding sites. Our results also implicate biophysical mechanisms by which aggregates of DCTN1 and TDP-43 are formed in Perry-diseased neurons. It remains to be clarified whether non-aggregated forms of mutant DCTN1 triggers TDP-43 aggregation, and whether mutant DCTN1 aggregation occurs earlier than TDP-43 aggregation, or simultaneously. It also remains to be understood whether coaggregation proceeds at the surface or in an intermingled manner or both; interestingly, as mentioned above, we frequently observed these two modes of coaggregation, colocalization and surface-to-surface contacts of DCTN1 aggregates with TDP-43 aggregates, even in the same cells. In addition, our data indicated that the CAP-Gly-basic domain, dynactin domain, and the C-terminal region of DCTN1 act as distinct functional modules for controlling TDP-43 cytoplasmic-nuclear transport and aggregation.Taken together with the previous studies, our results support the two currently well-discussed aspects of Perry disease-linked mutant DCTN1: loss of function (reduced microtubule-binding and impairment of dynactin recruitment at microtubule plus-ends) and gain of function (induction of TDP-43 aggregation), both of which compromise the cytoplasmic-nuclear transport of TDP-43.Recent studies have revealed that mislocalization of TDP-43 from the nucleus to the cytoplasm and the cytoplasmic aggregation of TDP-43 impairs the machineries for nuclear protein import and RNA export ,63. MoleConsistently, dynein heavy and light chains were found in TDP-43 aggregates purified from transfected neuroblastoma cells . As discG71A, D∆4, or D∆6, nuclear clearance of TDP-43 was observed less frequently (less than 1%) in U2OS cell models coexpressing TDP-43 and mutant DCTN1 (unpublished observations); but significantly (25%–30%) in iPSC-derived neurons coexpressing TDP-43 and mutant DCTN1  at Fukuoka University.cDNA encoding human DCTN1 variant 1 (accession Number: NM_004082) was obtained from Origene  (SC110869). The coding region of DCTN1 was amplified by polymerase chain reaction (PCR) and subcloned into pcDNA3.1/CT-GFP-TOPO plasmid . Following confirmation by DNA sequencing, DCTN1 point mutants  were generated using a QuikChange II XL site-directed mutagenesis kit . The cDNAs encoding wild-type/full-length DCTN1, point mutants or truncated mutants were reamplified by PCR using KOD Plus (Ver. 2) polymerase , and subcloned into SacII/AgeI sites of mEGFP/pRK5 vector , to make DCTN1-mEGFP expression plasmids, or 2× myc/pRK5  to make DCTN1-myc expression plasmids.To clone cDNA encoding human TDP-43, double-stranded Human Liver QUICK-Clone cDNA  was used for reverse transcription-PCR, according to the manufacturer’s instructions. Full-length cDNAs were cloned into XhoI/BamHI sites of mCherry-C1 plasmid  was replaced with the mCherry-coding sequence). mCherry-TDP-43-∆NLS was generated using a QuikChange Lightning site-directed mutagenesis kit (Agilent Technologies), based on the same design as previously described . The codThe nucleotide sequences of DCTN1, TDP-43, their missense mutants and truncated mutants used in this study were confirmed by DNA sequencing .Antibodies against DCTN1 , TDP-43 , and β-tubulin ; Sigma-Aldrich, St. Louis, MO, USA; TUB2.1) were used for immunoprecipitation and/or Western blotting. Antibodies against GFP , RFP , c-Myc , Myc-tag , and horseradish peroxidase (HRP)-conjugated anti-RFP antibody  were also used for the detection of tagged DCTN1 and TDP-43 proteins.HRP-conjugated secondary antibodies used for Western blotting in this study were: goat antimouse IgG , AffiniPure donkey antigoat IgG , Amersham ECL donkey antirabbit IgG , and mouse antirabbit IgG (conformation-specific) mAb .Cercopithecus aethiops) fibroblast COS-7 cells and human osteosarcoma U2OS cells were obtained from ATCC. Cells were maintained in Dulbecco’s modified Eagle’s Medium  supplemented with 10% fetal bovine serum , 1% penicillin/streptomycin (Thermo Fisher Scientific), and 2 mM L-glutamine (Thermo Fisher Scientific). All cells were cultured in a 5% CO2 incubator at 37 °C.African green monkey , without any antibiotic treatment, ~24 h before transfection. Transient transfection was performed using Lipofectamine 3000 (Thermo Fisher Scientific), according to the manufacturer’s instructions. Briefly, cells were transfected in Opti-MEM I reduced serum medium  by adding a mixture of 6 μL of Lipofectamine 3000 reagent in Opti-MEM and combinations of plasmids plus 5 μL of P3000 reagent in Opti-MEM I [4Cl for 10 min at room temperature to reduce autofluorescence, and incubated with Hoechst 33,342 (Molecular Probes/Thermo Fisher Scientific) for nuclear counterstaining. Samples were mounted in Permafluor (Thermo Fisher Scientific), and observed under a confocal microscope.For transfection with plasmids, cells were seeded at 2.0 × 10ti-MEM I . The folNEUROG2-inducible human iPSC (201B7) lines, where NEUROG2 is overexpressed upon treatment with doxycycline, were maintained using a feeder-free culture system  [5 cells/well) were replated onto poly-D-lysine/laminin-coated coverslips  in a 24-well plate or μ-dishes , and directly differentiated into neurons by treatment with 1 μg/mL doxycycline for 7 days and then by stimulation with 20 ng/mL brain-derived neurotrophic factor , 20 ng/mL Glial cell line-derived neurotrophic factor , 1mM dibutyryl cyclic AMP , and 200 nM ascorbic acid  in Neurobasal medium  supplemented with B-27  for 3 days. After a total of 10 days of neuronal differentiation, iPSC-derived neurons were cotransfected with the DCTN1-mGFP  and mCherry-TDP-43 expression plasmids using Lipofectamine 3000, following the same protocol as above. The cells were fixed 48 h after transfection by adding 4% PFA + 10% sucrose in PBS, stained with Hoechst 33,342 and observed under a confocal microscope. In the current experiments, the survival rates of neurons coexpressing D∆5 or D∆6 and TDP-43 were too low for observation, possibly due to their cell death-inducing effects in differentiated neurons. Thus, analyses on these cells were excluded from our present study.; AK02N) ,70. The For coimmunoprecipitation between endogenous Dctn1 and Tdp-43 proteins, cell extracts were prepared from embryonic day 16.5 (E16.5) mouse whole-brain isolated from pregnant ICR mice . The buffer used contained 50 mM Tris-HCl (pH7.4), 150 mM sodium chloride, 1 mM EDTA, 0.5% NP-40, and 0.5% sodium deoxycholate; supplemented with 5 mM sodium orthovanadate, 10 mM sodium fluoride, and cOmplete Mini . The brain cell lysates were preabsorbed with Protein G-conjugated Sepharose (Cytiva), and then incubated with a goat anti- DCTN1 antibody at 4 °C for 17 h. The immunoprecipitates were recovered using SureBeads Protein G magnetic beads  for 2 h. Beads were collected by using DynaMag-2 (Thermo Fisher Scientific) and washed five times with the above buffer. Recovered proteins were eluted by adding 1 × Laemmli buffer to the beads and boiled at 95 °C for 5 min. The proteins were detected by Western blotting with the antibodies indicated in the For coimmunoprecipitation of tagged proteins, COS-7 cells were transfected with different combinations of plasmids encoding the wild-type/full-length, truncated mutant or point mutant protein of DCTN1 or TDP-43. Forty-eight hours after transfection, cell lysates were prepared using the same buffer as above except without sodium deoxycholate, and immunoprecipitated with anti-c-Myc, anti-GFP or anti-RFP antibodies and then with SureBeads Protein G magnetic beads.E.coli BL21-CodonPlus (DE3)-RIL (Agilent Technologies) at 15.5 °C for 16 h upon induction with 100 mM IPTG [To detect the in vitro binding between DCTN1 and TDP-43, recombinant GST-fused full-length TDP-43 proteins were expressed in  mM IPTG . After bImmunoprecipitates, pull-down samples, and cell lysates were resolved on an SDS-PAGE gel  together with Precision plus protein dual color standards (Bio-Rad), transferred onto Immobilon-P PVDF membranes (Millipore), and probed with the primary antibody as indicated and HRP-conjugated secondary antibodies as previously described . ImmunorImages of single optical sections and/or z-stacks of fixed cells were acquired using a laser-scanning confocal LSM710 microscope or super-resolution LSM880Airy microscope  . Quantification of images was performed using ZEN 3.0 SR (black) (Carl Zeiss) and MetaMorph . Images presented in The cells to be quantified were randomly selected on each coverslip. In each experiment shown in 2 atmosphere. Approximately 48–72 h after transfection, cells were live-imaged in CO2-dependent FluoroBrite DMEM media (Thermo Fisher Scientific), supplemented with 10% FBS, 1% penicillin/streptomycin, and 2 mM L-glutamine. Super-resolution images were acquired at intervals between approximately 4 and 6 s, in a single focal plane.Live-cell microscopy was performed using the LSM880Airy microscope (in super-resolution mode) with a 63×/NA 1.40 oil objective lens (Carl Zeiss) and an Incubation System S  at 37 °C and in a 5% COt-test or two-tailed Mann–Whitney test ; p < 0.05 was considered statistically significant.No statistical methods were used to predetermine sample size. Sample sizes were chosen based on previous experience to obtain reproducibility. The experiments were not randomized and the investigators were not blinded to allocation during experiments and outcome assessment. No data points were excluded, and all data collected from each individual experiment were used for analysis. Statistical analysis was performed using the two-tailed paired


CaM and CaBP1 can each bind to the IQ-motif within the C-terminal cytosolic domain of CaV, which promotes increased channel open probability under basal conditions. At elevated cytosolic Ca2+ levels (caused by CaV channel opening), Ca2+-bound CaM binding to CaV is essential for promoting rapid Ca2+-dependent channel inactivation (CDI). By contrast, CaV binding to CaBP1 prevents CDI and promotes Ca2+-induced channel opening . In this review, I provide an overview of the known structures of CaM and CaBP1 and their structural interactions with the IQ-motif to help understand how CaM promotes CDI, whereas CaBP1 prevents CDI and instead promotes CDF. Previous electrophysiology studies suggest that Ca2+-free forms of CaM and CaBP1 may pre-associate with CaV under basal conditions. However, previous Ca2+ binding data suggest that CaM and CaBP1 are both calculated to bind to Ca2+ with an apparent dissociation constant of ~100 nM when CaM or CaBP1 is bound to the IQ-motif. Since the neuronal basal cytosolic Ca2+ concentration is ~100 nM, nearly half of the neuronal CaV channels are suggested to be bound to Ca2+-bound forms of either CaM or CaBP1 under basal conditions. The pre-association of CaV with calcified forms of CaM or CaBP1 are predicted here to have functional implications. The Ca2+-bound form of CaBP1 is proposed to bind to CaV under basal conditions to block CaV binding to CaM, which could explain how CaBP1 might prevent CDI.L-type voltage-gated Ca Thus, CaM acts as both an accelerator and a brake to control CaV channel opening i = 100 nM vs DappK = 100 nM), which may have functional implications (2+ binding to either CaM or CaBP1) are needed to test whether Ca2+ binding to the C-lobe of CaM (or CaBP1) is essential for the increased CaV channel open probability caused by CaM (or CaBP1) under basal conditions.CaV channels are oppositely regulated by CaM and CaBP1: CaM binding to CaV is essential for channel CDI, whereas CaBP1 binding prevents CDI and promotes CDF. A careful analysis of available Caications . Future


Immobilization of uricase on MBs can decouple the functionalization steps from the sensor surface, which allows the sensor to be reusable. Our microsensor platform exhibits a relatively lower detection limit (1 μM), high sensitivity (5.6 mV/decade), a linear range (from 1 μM to 1000 μM), and excellent linearity (R2 = 0.9945). In addition, interference assay and repeatability tests were conducted, and the result suggests that our method is highly stable and not affected by common interfering substances (glucose and urea). The integration of this high-performance and compact biosensor device can create a point-of-care diagnosis system with reduced cost, test time, and reagent volume.In this study, we developed a low-cost, reusable, and highly sensitive analytical platform for the detection of the human metabolite uric acid (UA). This novel analysis platform combines the graphene chemoresistor detection technique with a magnetic bead (MB) system. The heterojunction (single-layer graphene and HfO The detection and quantification of biomarkers are essential for medical diagnostics, environmental monitoring, and bioresearch. Uric acid is a metabolite in whole blood and is crucial in the diagnosis of many clinical diseases , such asGraphene-based nanomaterials are used as transducers of biosensors, which are involved in converting the interactions between the receptor and the target molecules into detectable measurements ,15. The In the past decades, the combination of MBs with conventional biological assay techniques has achieved great success due to the excellent properties of MBs, which include scalable and reusable capabilities, a high specific surface area, less toxicity, powerful magnetism, and high loading of the sensitive matrix . In the Here, we first proposed combining MBs and graphene chemoresistors as a microsensor platform for uric acid detection. This method overcomes the aforementioned drawbacks of the traditional sensor method. First, the proposed uric acid sensor is portable, reusable, and simple and has a low-cost fabrication process. Based on our calculation, the cost was approximately 10 USD. As it is reusable, the cost of each single test could be much lower. Second, the receptor functionalization step is achieved on the MB surface, breaking the main limitation of performance degradation caused by repeated modification of the graphene channel surface. Test results showed that the analysis platform exhibits excellent performance for the detection of uric acid. Miniaturization of the micro-biosensing platform endows itself with a promising prospect of application in a portable real-time instrument for point-of-care diagnostics.− as the pH increases [− make graphene p-doped; n-doped and p-doped graphene is able to modulate the channel conductance by doping holes or electrons, which is consistent with other graphene studies [The mechanism of our graphene-based biosensor detection of uric acid is shown in ncreases . Therefo studies ,24,25.3) and hydrochloric acid (HCl), which corrode copper foil, were purchased from Aladdin Reagent Co, Ltd. . Deionized water used in this work was purified using Milli-Q water purification. Buffer formulation ingredients, sodium sulfate (Na2SO4), sulfuric acid (H2SO4), sodium dihydrogen phosphate (NaH2PO4), sodium hydrogen phosphate (Na2HPO4), sodium bicarbonate (NaHCO3), and sodium carbonate (Na2CO3) included, were bought from Sinopharm Chemical Reagent Co, Ltd. . Dynabeads M-280 Tosylactivated (MBs), bovine serum albumin (BSA), and uricase, which was used to modify MBs, were purchased from Thermo Fisher Scientific. Phosphate-buffered saline (PBS) needed for this assay was purchased from Aladdin Reagent Co, Ltd. .Iron chloride hexahydrate  of the graphene chemoresistor. A Raman spectrometer (RamTracerTM-200 Raman Spectrometer) was performed to obtain Raman spectra to characterize the quality, layer number, and uniformity of graphene.An H-600 Hitachi scanning electron microscope  was used to characterize the scanning electron micrographs of the graphene morphology. Samples were imaged under the high-vacuum mode at magnifications of 800×. A Keysight 34465A digital multimeter was used to measure the source-drain voltage (4) was introduced into the chamber with a flow rate of 35 sccm for 10 min to initiate the growth of graphene; at the same time, 35 sccm of hydrogen gas was added to the chamber .The single-layer graphene films in our experiment were grown on copper foils by low-pressure CVD (LPCVD). First, copper substrates were pretreated by an annealing process, and the surface morphology of the copper substrate significantly improved. Then, copper foils were pre-cleaned in acetic acid at 35 °C for 10 min to remove the surface oxide . Subsequ2 (20 nm) was deposited by atomic layer deposition (ALD).I) of 1 mA at different pH values of the solutions . The pH change of the solutions was regulated by adjusting the proportion of buffer compositions. Respectively, neutral buffers of different pH values (from pH 6.0 to pH 8.0) were prepared by mixing 0.2 mol L−1 of NaH2PO4 and 0.2 mol L−1 of Na2HPO4, while acidic buffers of different pH values (from pH 1.7 to pH 4.1) were prepared by mixing 0.01 mol L−1 of Na2SO4 and 0.01 mol L−1 of H2SO4, and alkaline buffers of different pH values (from pH 9.17 to pH 10.83) were prepared by mixing 0.1 mol L−1 of Na2CO3 and 0.1 mol L−1 of NaHCO3.To study the effect of pH on the performance of the graphene chemoresistor, acquisition of electrical signals was performed through a Keysight 34465A digital multimeter at a constant source and drain current .−1, 1590 cm−1, and 2700 cm−1, respectively. The related assignments of spectral peaks to chemical bonds can be found in our previously published works [I2D/IG ratio was about 2, and more than 90% of the graphene film was determined as a single layer. In addition, the relatively weak D peak and the large 2D peak indicated the high quality and low defect density of graphene.Scanning electron microscope (SEM) analysis was used to determine the morphology of graphene. SEM photomicrographs made at 800× magnification of graphene on a glass substrate are shown in ed works ,29,30. BtotalV). Measurements of the source-to-drain voltage as a function of time demonstrated stepwise increase along with the discrete change of the buffer’s pH. The results are shown in −1 for the neutral solution, 81 mVpH−1 for the acidic solution, and 70 mVpH-1 for the alkaline solution. The standard deviations of the test were 2.29% (for pH = 6–8), 4.52% (for pH = 1.7–4.1), and 2.69% (for pH = 9.17–10.83).We evaluated the performance of our biosensor in acidic, neutral, and alkaline solutions . To conclude, our biosensor exhibits good corresponding linearity and sensitivity performance in buffer solution, which suggests that our graphene chemoresistor is a microscale pH sensor. The testing results above also prove the feasibility using the biosensor to detect highly efficient reactions of uric acid and uricase.Uricase is immobilized on beads to specifically catalyze the oxidation of UA. Uricase hydrolyzes free uric acid according to Equation (1) below :(1)Uric totalV) of the graphene sensor decreased to varying degrees with the addition of different concentrations of uric acid. 2 = 0.995) was obtained when the UA concentration was changed from 0 μΜ to 1 mM, as shown in As shown in Selectivity is the ability of a biosensor to generate a positive result only from interactions. p < 0.01, N = 3). The above testing results demonstrated similar behaviors with voltage-time plots, which is similar to what was shown in The graphene biosensor was then subjected to a repeatability test. Compared with the traditional methods for UA detection, our system demonstrated better performance in terms of the detection range and limit of detection. The results are summarized in 2 was deposited on the surface of high-quality graphene to improve the pH response of the graphene sensor. After verifying the feasibility of the graphene biosensor to detect the change in pH in acidic and alkaline environments, it was combined with magnetic beads for the detection of uric acid. The low-cost and scalable analysis platform exhibited excellent performance for detecting uric acid, including a lower detection limit (1 μM), good sensitivity (5.6/dec), and excellent linearity (0.995). The sensor showed good real-time detection performance, good stability, simple operation, and specificity for uric acid. Furthermore, this proposed method can potentially be applied to biological sample detection in whole blood and serum in the future after optimization. All of these features suggest that our platform has the potential to be a competitive method in the field of healthcare monitoring and clinical diagnosis.In summary, by atomic layer deposition, 20 nm of HfO


The process of graphene defect generation was studied through the ball milling process. The effects of defect content and temperature on the graphene repair process were studied separately. The study found that the graphene defect repair process, the decomposition process of oxygen-containing functional groups, and the deposition process of active C atoms existed simultaneously in the CVD process. When the repair temperature was low, the C atom deposition process and the oxygen-containing functional group decomposition process dominated. In addition, when the repair temperature is high, the graphene defect repair process dominated. 3 wt% graphene/Cu composites were prepared by pressure infiltration, and it was found that the bending strength was increased by 48%, the plasticity was also slightly increased, and the thermal conductivity was increased by 10–40%. This research will help reduce graphene defects, improve the intrinsic properties of graphene, and provide theoretical guidance for the regulation of C defects in composites.Graphene has extremely high theoretical strength and electrothermal properties, and its application to Cu-based composites is expected to achieve a breakthrough in the performance of existing composites. As a nano-reinforced body, graphene often needs a long time of ball milling to make it uniformly dispersed, but the ball milling process inevitably brings damage to the graphene, causing the performance of the composite to deviate from expectations. Therefore, this paper uses CH Howeviscovery ,9,10. Griscovery ,12.4C3 is formed, which reduces the strength of the composites [The high performance of graphene is directly related to its intrinsic structure. The unique two-dimensional structure of graphene has delocalized electrons when intact, making it possess extremely high in-plane electrical conductivity, thermal conductivity, and mechanical properties . Howevermposites ,21.In order to solve the problem of graphene damage, researchers have conducted research from two perspectives: avoiding the introduction of defects during material processing and repairing graphene defects. Short-time high-energy ball milling can greatly reduce the damage to graphene caused by the dispersion process. Yue et al.  prepared5 S/m. It is much higher than RGO (7.96 × 103 S/m) which has only undergone chemical reduction. High-temperature graphitization has the best effect, but it is difficult to apply to metal matrix composite systems. Liquid repair and doping repair work by in-situ self-generation or diffusion into the graphene lattice under liquid conditions to prepare carbon atom-filled or heteroatom-doped graphene structures. It is suitable for liquid phase dispersion of graphene while realizing defect control. However, the repair effect is not obvious enough, and the improvement of material performance is small.By reducing the speed of the ball mill and shortening the time of the ball milling, serious damage to the graphene caused by the ball milling process can be avoided. However, short-term ball milling still inevitably introduces a small amount of defects to the graphene. In order to further reduce the defect content of graphene, other methods are used to repair the defects of low-damage ball-milled dispersed graphene. At present, the graphene repair methods reported mainly include high temperature graphitization repair ,24, Chem4 plasma to repair defects in graphene. The study found that the Hall mobility of graphene increases significantly with the increase in the degree of repair, from 1 cm/(V·S) to 52 cm/(V·S), while the resistivity decreases significantly. Grimm et al. [4 S/m, and the agglomeration between graphene layers is avoided, which effectively increases the specific surface area. However, in current research, CVD is mainly used for defect repair of graphene powder. After the graphene and metal powder is dispersed by ball milling, the method and extent of CVD repairing graphene have not been studied.CVD repair mainly uses free radicals generated by the decomposition of carbon-containing gas as a C source at high temperatures to fill and repair graphene defects spontaneously. Zhu et al.  used CH4m et al.  used isom et al.  used CVDIn this work, pure copper was selected as the matrix and GNPs as the reinforcement. GNPs/Cu composite powder was prepared by high-energy ball milling, and the defects of GNPs during the ball milling process were repaired by the CVD method. The graphene defects were characterized by Raman Spectrum (Raman) and X-ray Photoelectron Spectroscopy (XPS), the repair effect of CVD on graphene defects was studied, and the best defect repair process was explored. The powder is sintered into a composite by Spark Plasma Sintering (SPS). By comparing the mechanical properties, thermal conductivity, and microstructure of the composites with or without repair, the effect of defect repair on the performance is studied, which provides theoretical guidance for the preparation of low-damage GNPs/Cu composites.The pure Cu powder used in this study was purchased from Beijing Xingrongyuan Co., Ltd., Beijing, China, with a purity of 99.9% and an initial particle size of about 3 μm. The characterization results are shown in DI/GI = 0.19, and the value of DI/GI indicates the defect content of graphene. The graphene used in this experiment has fewer defects. The original graphene was subsequently characterized by XPS. The XPS results show that the GNPs C atoms are mainly sp3 C, with a small amount of sp2 C defects and some oxygen-containing functional group defects. The ratio of the peak area of sp3 C atoms to the total area can reflect the content of graphene lattice defects. From the figure, it can be seen that the defect content of the original graphene is about 30%, and the content of functional group defects is about 8%. The TEM characterization of graphene is shown in The graphene  used in this experiment was prepared by the exfoliation method, and its Raman spectrum test results and XPS test results are shown in 2 grinding balls were added to each ball milling jar . In addition, 500 g ethanol was added as a grinding aid. The ball mill selected a speed of 250 r/min, and the ball mill stopped for 25 min every 5 min to prevent the danger of overheating. The graphene and Cu were ball milled for 120 min to make them uniformly dispersed. After ball milling, the graphene-Cu mixed slurry was separated through a screen and dried at 70 °C for 24 h to obtain graphene-Cu mixed powder. The chemical state of graphene after ball milling was characterized by Raman and XPS.High-energy ball milling is a commonly used method to introduce graphene into Cu powders. This method is easy to operate and has a good mixing effect. However, the impact and shear of the graphene during the ball milling process will also destroy the integrity of the graphene structure. In this study, a planetary ball mill  was used to disperse the graphene, and the ball-milling speed of 250 r/min was used to ensure the uniform dispersion. 1.5 g of graphene, 48.5 g of Cu powder and 500 g of ZrO4) was chosen as the carbon source and argon (Ar) was chosen as the shielding gas. The ratio of Ar to CH4 is 10:1. In the experiment, 800 °C, 900 °C and 1000 °C were selected to treat the powder to characterize the evolution behavior of graphene defects at different temperatures. The gas flow rate is 20 sccm (stand mL/min), the pressure is 280 Pa, and the reaction continues for 30 min. After cooling in the furnace, the product was taken out for subsequent characterization and experiments.In order to reduce the damage of graphene, CVD is used to repair graphene defects. The CVD process is carried out in a pipe furnace . Methane  during sintering was 2:1. After the sintering is completed, the sample is cooled to room temperature in the mold with the furnace. Subsequent structural characterization and performance testing of composites.Morphologies of the GNPs/Cu powders and the composites were observed by FEI Quanta 200FEG . Raman analysis was performed on a JY-HR800 laser Raman spectrometer  using a 532 nm solid-state laser as an excitation source. X-ray Photoelectron Spectroscopy was performed on ESCALAB 250Xi  spectrometer with a monochromatic Al Ka radiation source at 15 kV and 150 W. Tensile samples with dimensions represented in our previous work have been tested on Instron 5569 universal electrical tensile testing machine  with a cross-head speed of 0.5 mm/min. All the tensile tests have been performed on at least four samples to improve the statistical significance of the results. The LFA467 laser thermal analyzer  was used to characterize the thermal diffusivity of the GNPs/Cu composites, and the test temperature was 25 °C.To study the ability to which CVD can repair GNPs defects, it is necessary to prepare GNPs with different defect contents. In order to obtain graphene with different defect content, four different ball milling times were designed, namely BM1h, BM2h, BM5h, and BM10h. DI) and the G peak (GI) is generally considered to be an apparent manifestation of the defect content of graphene. This is because when the defect content does not exceed a certain ratio, DI/GI is proportional to the average distance between the two defects on the graphene [DI and GI are the intensity of peak D and peak G in the Raman spectrum, respectively; λC is a constant related to the wavelength of the test laser; dL is the average distance between two defects on the graphene.The degree of damage of GNPs was characterized by Raman. The intensity of the D peak  and ball milled powder repaired by CVD at 1000 °C (1000 °C CVD-BM10h), which have the most defects and the most obvious graphene repair effect. The density and elastic modulus of the composite material were characterized, and the results were shown in Afterward, the composite material was tested for bending performance, and the results are shown in The fracture of the composite is observed as shown in The thermal conductivity of the two composites was characterized, the temperature used in the test was normal, and the results are as shown in In this paper, the evolution and control of defects in graphene processing are studied. Through mechanical ball milling, the damage behavior of graphene during ball milling was studied, and the relationship between ball milling time and graphene defect content was established. The graphene defects were repaired by CVD, and the effects of temperature and initial defect content on the graphene repair process were studied.Studies have found that CVD has a repairing effect on graphene defects, which can be significantly observed before and after the repair of graphene samples after ball milling for 5–10 h. The more the defect content, the more obvious the CVD repair effect. The defects of graphene ball milled for 10 h decreased significantly with the increase of CVD temperature, reflecting the promotion of temperature on the graphene repair process. Combined with Raman and XPS, the evolution mechanism of defects is analyzed. Since CVD repair is a process of carbon source gas cracking to generate active C atoms, which are deposited on the surface of graphene. Simultaneously existing in the CVD process: graphene repair, decomposition of oxygen-containing functional groups, and at the same time, with excess C atoms, new graphene with more defect content is generated in situ on the Cu matrix. When the CVD temperature is low, the deposition of C atoms dominates, and a large amount of new graphene with defects is deposited on the surface of the original GNPs-Cu, which leads to an abnormal increase in the content of defects. Increasing the CVD temperature will greatly increase the diffusion rate of C atoms, and the hole defects will be repaired by C atoms. The evolution of defects in graphene during CVD is the result of the coordination of three functions.On this basis, the mechanical properties and thermal conductivity of composite materials prepared by CVD repaired graphene were studied, and it was found that the bending strength was increased by 48%, and the plasticity was also slightly improved. After the repair, the thermal conductivity also has a significant increase in the in-plane and inter-layer thermal conductivity, which is mainly attributed to the repair of defects by CVD.