Graphene is widely used as the basic materials of nano optical devices and sensors on account of its special structures and excellent photoelectric properties. Graphene is considered as an ideal material for photodetectors because of its ultra-wide absorption spectrum from the ultraviolet to the terahertz band, ultrahigh carrier mobility and ultrafast photoreaction speed. In this study, a photothermal nano-device was made using graphene that was transferred to an electrode using an all-dry viscoelastic stamping method. The nano-device has the advantages of simplicity, high efficiency and instant measurement. This nano-device was used to measure the light absorption of graphene, and the calculated light absorption rate of graphene is basically consistent with previous research results. Experiments on irradiation at different wavelengths and thermal heating at different temperatures show that the nano-device has an excellent response to near-infrared and mid-infrared light. The conclusions provide an experimental basis for the research, design and fabrication of nano-devices, and this device can provide an effective method for detecting light and temperature in areas such as electronic components and solar cells. In recent years, the electronic components industry and the solar cell industry have developed rapidly, which have promoted higher requirements for the detection of light and heat. Graphene has the advantages of a large wavelength range of light detection, fast response speed, excellent thermal conductivity, etc.; therefore, nano-devices made of graphene can be used as sensors to meet the requirements of the future electronic-component industry and solar cell industry ,2. GraphThere have been many reports on the optical and thermal properties of graphene. Nair  used graPrevious researchers focused on the light absorption of graphene, but the experimental methods are relatively complicated, and there is a lack of a simple, effective and real-time nano-device that can monitor light and heat sensing. In this paper, a kind of nanometer device made of graphene, created using an all-dry viscoelastic stamping transfer method, has been applied, which is simple and efficient for doing research on light absorption, light response and thermal heating. This nano-device can provide effective guidance for the application of graphene and other two-dimensional materials in the electronic components industry and solar cell industry.The electrodes were obtained by ultraviolet photolithography and evaporation on a silicon oxide substrate. The manufacturing process of the electrode structure was as follows: (1) Silicon wafer cleaning: the 5-inch silicon wafer was soaked successively in acetone and isopropanol, and then put in deionized water and then blown with a nitrogen gun to remove grease and other impurities from the surface; (2) spin-coating the photoresist: AZ5214E photoresist was uniformly spin-coated on the silicon wafer using a homogenizer; (3) pre-baking: the sample was pre-baked in order to reduce the moisture in the photoresist and avoid the thermal cross-linking effect of the photoresist; (4) pre-exposure: the 5-inch silicon wafer was pre-exposed under a mask by an ultraviolet photoengraving machine; (5) baking: the pre-exposed samples were roasted again to modify the photoresist in the exposed area; (6) exposure: the mask plate was removed before the sample was exposed, and the exposure time was 12 s to ensure that ultraviolet light expose the photoresist thoroughly; (7) development: the sample was transferred to an MIF300 developer for development; (8) metal electrode evaporation and plating: metal electrode evaporation and plating were carried out using high temperature vacuum thermal evaporation equipment. The thickness of the Au deposited layer was 45 nm; and (9) lift off process: the sample was put in acetone solution for 30 min, and the metal was stripped in a heating stage at 75 °C, rinsed with deionized water, and blow-dried to complete the production.Graphene was obtained from graphite by heat-assisted mechanical stripping. The process used was as follows: (1) preparation of adhesive strips: the 3M Scotch tape was cut into rectangular strips, then placed the adhesive surface facing up on a clean and flat dust-free paper; (2) crystalline flake graphite transfer: tweezers were used to grab crystalline flake graphite in the middle of the strip along the width direction, so that the graphite crystals were sequentially transferred in the middle of the strip; (3) flattening of crystalline flake graphite: the tips of tweezers were used to touch the sticky graphite crystals to make sure that they are flat on the surface of the strip; (4) peeling: both ends of the strip were held and folded the strip in half for 10–15 times to ensure that two-thirds of the strip were covered with graphene; (5) preparation of flexible transfer substrate: polydimethylsiloxane (PDMS) was used as the material transfer substrate in the experiment to ensure that the van der Waals force between the material and the flexible transfer substrate was less than the van der Waals force between the material and the silicon substrate; (6) heat-assisted baking: the strip with graphene was adhered to the PDMS substrate and the whole sample was baked on a heating table for 1 min at 100 °C before peeling the strip in order to increase the probability of transferring the graphene to the PDMS; (7) rapid peeling: the strip needed be quickly peeled off after baking; and (8) screening of graphene: the PDMS substrate with graphene was placed on an optical microscope for screening. Samples with a thin thickness, uniform surface and regular shape were preferentially selected and then the position marks are made.Generally, the transfer method of two-dimensional materials depends on the use of polymer layers and wet chemistry, which sacrifices the performance of two-dimensional materials to some extent. The all-dry transfer method relies on a viscoelastic stamp and does not use any wet chemical steps . BecauseThere are two main types of interactions between light and graphene from the perspective of energy band transitions: inter-band transitions and intra-band transitions. The dominant transition mode depends on the energy of the photon. In the near-infrared and visible light bands, the light response is mainly inter-band transitions, and the absorption coefficient is determined by the fine structure constant. In this case, the light absorption of graphene can be regulated by adjusting the position of the Fermi plane due to the vesicle blocking principle. The energy at the K point of the two-dimensional graphene’s Bridgeport region is linearly related to momentum and the effective mass of the carrier is 0, which is a remarkable feature that distinguishes graphene from the electronic structure of conventional materials. This energy band relationship gives graphene unique physical properties, such as the quantum Hall effect and near-ballistic transport of carriers at room temperature. In terms of its optical properties, single-layer graphene has a high light absorption rate due to the linear distribution of Dirac electrons. Graphene absorbs 2.3% of each layer from the visible to the terahertz wide band .A constant pressure of 1 V was applied to both ends of the electrode, the incident light wavelength was 950 nm, the measurement time was 20 s, and the measured photocurrent curve is shown in In this experiment, light-emitting diodes with different wavelengths  were used to irradiate the fabricated device at the distance of 10 mm, as shown in The voltage-current diagram when the device is irradiated with 940 nm wavelength at different distances  is shown in In order to study the effect of light switching on the light absorption of the graphene device, the graphene device is irradiated intermittently with light at a wavelength of 850 nm and 940 nm. The nano-device was placed on a three-dimensional micrometer operating platform, and the relative position between the sample and the incident laser was adjusted through the change of the current over time. The position with the largest current change of the photoelectric device was taken as the laser irradiation position, that is, the area with the most significant photoelectric response. The left terminal was connected to the SMU1 of the semiconductor tester as a drain, and the right terminal was connected to the SMU3 of the semiconductor tester as a source. In the test, the bias voltage of drain terminal was set to 1 V, and the source terminal was grounded. The laser position is adjusted so that the laser focal plane was on the surface of the test device and the laser was approximately 10 cm away from the surface of the device. The light source was turned off during the first 30 seconds of the experiment, then the light source was turned on for 30–150 s, and so on. The resulting curve is shown in A constant voltage of 1 V was applied across the gold electrode, and the graphene device was irradiated with light of different wavelengths  at a distance of 10 mm. The resulting photocurrent relationship is shown in Transistor devices made of single-layer or few-layer of graphene with zero bandgap can be used as ultrafast photoelectric detectors. The graphene surface absorbs photons to produce electron–hole pairs that can be rapidly compounded, and the speed of the composite is dependent on the temperature and the concentration of electrons and holes. When an external electric field is applied, the electrons and voids can be pulled apart to produce a photocurrent, and the same effect can be achieved when there is a built-in electric field at the interface between the electrode and the graphene. Under the working condition of constant voltage, a change of carrier concentration is reflected as a change of current between source and drain, so the detection of light is realized. Graphene as a carrier transmission channel can improve the response speed of a light detection sensor device. By comparing the response time of the graphene nano-device with that of nanowires made by Hyungwoo , it can Since the maximum detection temperature in the field of electronics and solar cells generally does not exceed 100 °C, the graphene device is heated intermittently with a heating source at different temperatures  at a distance of 10 mm as shown in The photocurrent measured at a constant voltage of 1 V is shown in In this study, a photothermal nano-device is made by graphene, which is transferred to the electrode using an all-dry viscoelastic stamping method. This nano-device is simple and efficient for doing research on light absorption, light response and thermal heating. The light absorption rate of graphene measured by this nano-device is 2.216%, which is basically consistent with previous research. The experiment demonstrated that this graphene nano-device is effective and stable as sensors for detecting near-infrared light. It is proved that the graphene device has a faster and more sensitive response when detecting high temperature objects, through the irradiation with different temperatures. The conclusions of this paper provide an experimental basis for the research, design and fabrication of nano-devices, and provide effective guidance for the application of graphene and other two-dimensional materials in the electronic components industry and solar cell industry.


Idiopathic pulmonary fibrosis (IPF) is a rare, progressive interstitial lung disease (ILD) with a poor prognosis . The treDuring the last years, an increasing number of IPF disease registries have emerged in order to obtain real-world, long-term data in a broader patient population, complementary to clinical trials. In Europe alone, there are over 90 individual IPF registries by now; a minority also collects data about other ILDs . PatientHoltze and colleagues recently addressed a few of these questions, by publishing a detailed characterization of IPF treatment patterns in the United States (US), using the Pulmonary Fibrosis Foundation Patient Registry (PFF-PR) . The PFFThis study yielded some interesting findings regarding real-world diagnosis and management of IPF in the US . Less thFactors associated with anti-fibrotic use in the PFF-PR registry were recent clinical trial participation, lower diffusion capacity of the lung, oxygen use, and increased time since diagnosis, suggesting that anti-fibrotic drugs are mainly initiated in patients with more severe disease . Data frIn this study, Holtze et al. reported on the baseline data of patients enrolled in the PFF-PR registry . Future Even though this recently published study emphasizes the added value of disease registries in capturing real-life data about diagnosis, treatment and follow-up of IPF patients, it also shows that the use of registry data poses a number of challenges , 24, 29.A group of ILD experts have recently proposed an idea to create a Europe-wide meta-registry for IPF, consisting of multiple individual registries (ARIANE-IPF) . The avaOther factors that should be taken into account in the design of registry studies are legal, ethical, privacy, and methodological issues, such as the handling of missing data. Because of the real-world nature, missing data are usually more common in registries than in clinical trials . New tecIdeas about the added value of registry data, current challenges, opportunities, and future directions are summarized in Fig. In conclusion, we believe that current challenges can be overcome by increasing multi-stakeholder collaboration in the next years. In that way, registry data will continue to provide answers on clinically relevant questions and improve our knowledge about IPF. Recent phase III trials have also demonstrated the efficacy of anti-fibrotic medication in non-IPF fibrotic ILDs, which will importantly change care for this group of patients , 37. Obv


Aluminum composites reinforced by graphene nanoplates(GNP) with a mass fraction of 0.5% (0.5 wt.% GNP/Al) were fabricated using cold pressing and hot pressing. An orthogonal test was used to optimize the fabrication parameters. Ball milling time, ball milling speed, and ultrasonic time have the largest influence on the uniformity of the graphene in the composites. Afterwards, the microstructure, interfacial properties, and fracture morphology of the composites obtained with different parameters were further analyzed. The results show that ball milling time and ball milling speed have obvious influences on the mechanical properties of the composite. In this paper, when the ball milling speed is 300 r/min and the ball milling time is 6 h, the dispersion uniformity of graphene in the 0.5 wt.% GNP/Al composite is the best, the agglomeration is the lowest, and the mechanical properties of the composites are the best, among which the tensile strength is 156.8 MPa, 56.6% higher than that of pure aluminum fabricated by the same process (100.1 MPa), and the elongation is 19.9%, 39.8% lower than that of pure aluminum (33.1%). Aluminum is a structural material used commonly in aerospace, automobile, machinery, electronics, and other fields because of its light weight, high strength, good ductility, easy processing, and so on ,2,3. TheIn recent years, research on graphene-reinforced Al composites has gradually increased. Yan et al.  used balAt present, there are still some problems in the fabrication of graphene-reinforced Al composites, such as how to disperse the graphene uniformly in the Al matrix ,25, how In this study, graphene nanoplates with a mass fraction of 0.5 were mixed with Al powder using ultrasonic dispersal in ethanol solution and ball milling, and the graphene-reinforced aluminum composites (0.5 wt.% GNP/Al) were prepared via cold pressing and vacuum hot pressing. To maximize the uniform dispersal of graphene in the Al matrix while retaining the integrity of the GNP to the greatest extent, the optimal fabrication parameter combination needs to be determined. Therefore, in this paper, the fabrication parameters were grouped by orthogonal testing, the effects of the five fabrication parameters on the dispersion uniformity of graphene were studied, and the main influential parameters were obtained. The effects of ultrasonication time, ball milling time, and ball milling speed on the mechanical properties or microstructures of the composites were studied, and the optimal parameters that ensure the largest strength of the 0.5 wt.% GNP/Al composites fabricated by the cold pressing and vacuum hot pressing were obtained.2/g and approximately 3–5 layers with a particle size of 0.1–5.0 μm. The pure Al powder produced by Shandong Sitaili Metal Materials Co., Ltd.  was used as the matrix whose particle size is approximately 30 μm; graphene was purchased from Qingdao Huagao Diluted Energy Co., Ltd.  with a specific surface area of approximately 400 mFirst, the pre-weighed graphene is mixed with an appropriate amount of industrial ethanol and placed in an ultrasonic cleaner  to reduce the agglomeration of graphene and increase its dispersibility. The ultrasonication time was set to 60 min or 90 min. Then, the alcoholic solution of graphene and Al powder prepared in the ethanol solution dispersion is packaged into a tank of a planetary ball mill  for ball milling. Stearic acid is used as the process control agent, which can increase the dispersibility and prevent cold welding. Nitrogen is used as a shielding gas to prevent Al powder from being oxidized.1, X2, X3, X4, and X5. As shown in 1 has 4 levels, while X2, X3, X4, and X5 have 2 levels.In this paper, ball milling speed, ball milling time, B-P ratio, ultrasonication time, and stearic acid content were selected as the factors to study. To simplify the experimental process, this paper uses the orthogonal test method to distribute the five fabrication parameters reasonably, and the orthogonal distribution table of parameters (L8 (4 × 24)) is shown in A particle size analyzer (Hydro-2000 Mu (A), Malvern instruments Ltd., Malvern, UK) was used to test the particle size distribution of the composite powders after ball milling. The purpose of ball milling is to achieve uniform dispersion of the graphene and uniform particle size of the composite powder. In the initial stage of this paper, the standard deviation value (SDV) of the particle size of the composite powder samples after ball milling, as shown in 1), the average value of SDV first changed from 0.39 (2 h) to a maximum of 2.0 (4 h), decreased to 0.055 (6 h), with a decrease ratio of 97.25%, and then increased to 1.775 (8 h). This shows that the ball milling time has a very obvious effect on the particle size homogenization of the composite powder, and the particle size of the powder is the most uniform when the ball milling time is 6 h. In addition, with the increase in ball milling speed (X2), the average value of SDV decreased from 3.52 (200 r/min) to 2.065 (300 r/min), with a decrease of 36.5%, indicating that the ball milling speed had a significant effect on the particle size homogenization of the composite powder, and the speed of 300 r/min could make the particle size more uniform. When the B-P ratio (X3) changed, the average value of SDV decreased from 2.90 to 2.675, a decrease of 7.8%, indicating that the ball-to-powder weight ratio has little impact on the particle size homogenization of the composite powder. When the ultrasonication time (X4) changed, the average value of SDV increased from 2.19 to 3.4, an increase of 35.6%, which indicates that the ultrasonication time has an obvious effect on the particle size homogenization of the composite powder. When the stearic acid content (X5) changed, the average value of SDV increased from 2.5825 to 2.755, an increase of 6.3%, indicating that the stearic acid content has little effect on the particle size homogenization of the composite powder. In summary, ball milling time (X1), ball milling speed (X2), and ultrasonication time (X4) are the three main factors affecting the particle size of the composites. In the following section, the effects of ultrasonication time (X4), ball milling time (X1), and ball milling speed (X2) on the properties of the composites and the mechanisms are further analyzed.The average SDV value of each factor at different levels is calculated to study the influence of the parameters on the dispersal of the composite, as shown in The composite powders with different parameters set by the orthogonal test were cold-pressed in a mold with a size of φ50 mm × 3 mm by a hydraulic press machine  at atmospheric temperature. The pressure was 500 MPa, the compression rate was 2 KN/min, and the holding time was 5 min. And then, the cold-pressed billets were hot-pressed in a vacuum thermocompressor  at 600 °C for 1 h with a pressure of 30 MPa supplied by another mould with the diameter of φ50 mm and then cooled in the furnace. Pure aluminium billet was also fabricated by the same processes.Samples were wire electrode cut from the hot-pressed billets of the composite and the pure Al billets for tensile testing, optical microscopy (OM), and SEM scanning. The size of the tensile samples ,29 is shA field emission SEM  was used to observe the morphology of the composite powder after milling and the tensile fracture morphology of the hot-pressed billets and to analyze the element of the composite (EDS). A Raman spectrometer  was used to test the components of the graphene, composite powders, cold-pressed, and the hot-pressed composite billets. X-ray diffraction  was used to analyze the components of the composite after vacuum hot pressing.The effects of the three major fabrication parameters on the properties of the 0.5 wt.% GNP/Al composites were studied via comparison of the macroscopic mechanical properties or microscopic characterization.−1, the G peak around 1580 cm−1, and the 2D peak around 2670 cm−1. It is known that the smaller the intensity ratio of the D peak to the G peak (ID/IG), the more complete the graphene, and the lower the intensity ratio of the 2D band to the G band(I2D/IG), the larger the number of layers. In this study, as shown in D/IG value of the original graphene in 2D/IG value is 0.269; the graphene ID/IG value is 1.19, and the I2D/IG value is 0.283 after ultrasound for 60 min, while the ID/IG value is 1.06 and the I2D/IG value is 0.622 after ultrasound for 90 min. The ID/IG value of graphene decreases while the I2D/IG value increases after ultrasound for 60 and 90 min, indicating that the graphene unfolded and the layer number decreased because of the ultrasonic action, and the longer the ultrasonic time is, the better the dispersion of graphene.Graphene has many surface atoms and dangling bonds and tends to agglomerate together to reduce the surface activity, which has a negative impact on the mechanical properties of the composites. In addition, due to the large density difference and poor wettability of the Al matrix and graphene, it is more difficult for graphene to uniformly disperse in the Al matrix. The polarity of ethanol is similar to that of graphene, and the van der Waals force between ethanol and graphene is greater than that between the graphene’s own layers. So, under the ultrasonic shaking, graphene in ethanol solution can unfold more easily, dispersing and extending without structural destruction. During high-energy ball milling, the deformation of powder is generally divided into three stages: from spherical to flattened, cold-welded to form larger plate-like particles, and broken to form smaller particles. Meanwhile, graphene was first dispersed on the surface of the flake Al powder and then cold welded into the Al particles. 1) when the ball milling speeds (X2) are 200 r/min and 300 r/min, respectively. D/IG value for 0.5 wt.% GNP composite powders with ball milling times. It can be seen from D/IG gradually increases, indicating that the graphene structure is gradually destroyed. At the same ball milling time, the Raman ratio ID/IG with 300 r/min is slightly higher than that at 200 r/min. This is because the high speed will cause a strong impact and a certain degree of damage to the graphene structure. However, the damage degree is limited, and when the ball milling speed is 200 r/min, the coating and bonding between the graphene and the matrix are worse than at 300 r/min, as shown in 3. The compactness can reach 99.6%. The density of the billet obtained using vacuum hot pressing is approximately 2.69 g/mm4C3 are detected, which may be due to the low content of graphene and the limited resolution of elements of the X-ray diffraction instrument [strument .p in v in To analyze the role of the graphene in the reinforcement of the composite, its distributions on the tensile fracture surface are compared in (1)4C3 were found in the composite. Graphene distributed on the grain boundaries can effectively hinder the growth of the grain during the vacuum hot-pressing sintering and play a role in grain refinements.The density of 0.5 wt.% GNP/Al prepared by cold pressing + vacuum hot pressing is high, and the interface bonding is perfect. No obvious oxidation phenomenon and Al(2)Ball milling time, ball milling speed, and ultrasonic time have great influences on the performance of 0.5 wt.% GNP/Al composites.(3)Adding 0.5% percentage of graphene in weight can obviously increase the strength of the Al matrix. When the ball milling speed was 300 r/min, the ball milling time was 6 h, the B-P ratio was 5:1, the graphene ultrasonic time was 90 min, and the stearic acid content was 1.5%, the graphene nanoplates were uniformly distributed in the Al matrix without being destroyed. The composite had the best comprehensive mechanical properties, with a tensile strength of 156.8 MPa, which is 56.6% higher than that of pure aluminum fabricated by the same process (100.1MPa), while the elongation is 19.9%, which is 39.8% lower than that of pure aluminum (33.1%).In this paper, 0.5 wt.% GNP/Al composites were prepared using ultrasonication + ball milling + cold pressing + vacuum hot pressing. The microstructure of 0.5 wt.% GNP/Al created by different fabrication parameters was systematically studied. The main conclusions are as follows:


N-acetylglucosamine kinase (NAGK), an enzyme of amino sugar metabolism, interacts with dynein light chain roadblock type 1 (DYNLRB1) and promotes the functions of dynein motor. Here, we report that NAGK interacts with nuclear distribution protein C (NudC) and lissencephaly 1 (Lis1) in the dynein complex. Yeast two-hybrid assays, pull-down assays, immunocytochemistry, and proximity ligation assays revealed NAGK–NudC–Lis1–dynein complexes around nuclei, at the leading poles of migrating HEK293T cells, and at the tips of migratory processes of cultured rat neuroblast cells. The exogenous expression of red fluorescent protein (RFP)-tagged NAGK accelerated HEK293T cell migration during in vitro wound-healing assays and of neurons during in vitro neurosphere migration and in utero electroporation assays, whereas NAGK knockdown by short hairpin RNA (shRNA) delayed migration. Finally, a small NAGK peptide derived from the NudC interacting domain in in silico molecular docking analysis retarded the migrations of HEK293T and SH-SY5Y cells. These data indicate a functional interaction between NAGK and dynein–NudC–Lis1 complex at the nuclear envelope is required for the regulation of cell migration.Recently, we showed that  Cell migration takes place during diverse developmental and pathogenic processes in multicellular organisms. Neuron migration during embryonic brain development essentially guides the complex layering of many structural and functional compartments. Neuronal progenitor cells (NPCs) are generated in spatially restricted ventricular zones (VZs) and undergo long-distance migration to reach their final destinations, e.g., the cortical plate (CP), to establish functional integrated neural circuitry ,2. NPCs Dynein complexed with lissencephaly 1 (Lis1) and doublecortin (DCX) mediates N–C coupling during neuronal migration, and dynein heavy chain generates nuclear movement , while LRecently, we identified a novel dynein interacting protein N-acetylglucosamine (GlcNAc) kinase . This enzyme phosphorylates GlcNAc to produce GlcNAc-6-phosphate, which is a component that is utilized in uridine diphosphate N-acetylglucosamine (UDP–GlcNAc) biosynthesis or energy metabolism in the GlcNAc recycling/salvage pathway. Human NAGK monomer is 37 kDa sized, composed of N-terminal  and C-terminal (large) domains , belongsDuring cell division, NAGK interacts with the perinuclear Dynein–Lis1–NudE1 complex during prophase nuclear invagination and with kinetochores during metaphase chromosome separation . These fThe yeast two-hybrid selection assay showed that NAGK strongly interacted with the C-terminal of NudC  interacted potently with the NudC CS domain. To improve understanding, free energy landscape analysis was conducted on the resultant trajectories to identify the most stable complex structure with the lowest energy minimum  maintained strong interactions with NudC during simulation, especially the Leu211 to Ile218 region, which indicated the presence of a major protein-binding interface in NudC. To achieve insight of the interaction between NAGK and NudC, we considered protein–protein docking simulation, which predicts complex structures from individual proteins. Accordingly, a full blind docking simulation was carried out to detect a putative binding site for NAGK in NudC. The docked complex obtained revealed a binding energy of −8.79 kcal/mol with a docking score of −29.35 kcal/mol . The com minimum Cc. Then,ith NudC Cd. As reinset, right panel, arrowheads). These findings indicate NAGK–NudC interacted at the leading edges of cell cortices during migration. NudC has a well-established role in migration, and thus, we examined the in situ colocalization of NAGK and NudC in migrating cells. First, semi-confluent (more than 95%) HEK293T cells were scratched as mentioned in Material and Methods, and then, cells were allowed to migrate toward “wounds” on coverslips. Then, immunocytochemistry (ICC) was performed using anti-NAGK and anti-β-tubulin primary antibodies to determine the migratory morphology of cells and the distribution of NAGK. Intracellularly, centrosomes were located in front of the nuclei with respect to the migration direction B. At theOur laboratory previously reported NAGK interacted with DYNLRB1 at neuronal dendrites , whereasinset 1, red arrowheads) and at cell cortices , and these were found to colocalize with DYNLRB1 ICC signals (green arrowheads). These results show NAGK interacted with NudC and dynein around nuclei and at cell cortices during cell migration. Next, NAGK–DYNLRB1 PLA was performed, followed by NudC ICC and DAPI counter-staining  using NAGK and NudC primary antibodies. To visualize NAGK–NudC–DYNLRB1 interactions, PLA was followed by ICC using anti-DYNLRB1 antibody, and nuclei were counter-stained with DAPI. NAGK–NudC interactions  due to PLA reactions were observed around nuclei  and near nuclear membranes , which suggested that NAGK participated in the neuronal migration in association with the NudC–Dynein complex. NAGK–DYNLRB1 PLA signals (red) also colocalized with NudC ICC signals (green) in leading neurites  were colocalized with DYNLRB1 ICC signals (green) in leading dendritic projections  and around nuclei . NAGK–Lis1 interactions were also observed in dendritic projections  and at nuclear peripheries  colocalized with NudC signals in migrating neurons . Together, these results show the colocalization of NAGK–Lis1–NudC at nuclear peripheries, in cell cortices, and in leading projections of migrating neurons.As NudC has been reported to interact with Lis1 during cell migration , we inveNeuronal migration has been reported to be compromised by dynein ,35 or NuNext, we used in utero electroporation to study the role of NAGK in neuronal migration in vivo during embryonic brain development. We introduced pDsRed2-NAGK Ba, pDsReIt was reported that NudC depletion significantly inhibited collective cell migration in a wound-healing experiment . To inve157WIAHQAVKIVFDSI171, and L198GILTHLYRDF208, we initially considered both regions for peptide design in order to confirm possible interactions with NudC binding domain   on cell migration, we performed two different types of wound-healing assays. First, we performed wound-healing assays after transfecting HEK293T cells with pDsRed2 or pDsRed2-NAGK and then further transfecting cells with the peptide. Percentages of migrating cells were calculated (defined as the percentages of transfected cells that migrated at migration fronts) after 48 h of incubation (p < 0.0001) greater than that of DsRed2 transfected cells. Transfection with peptide Y157WIAHQAVKIVFDSI171 significantly reduced the portion of percentage of pDsRed2–NAGK transfected cells (pDsRed2-NAGK + pep), but this was still higher than that of pDsRed2-transfected cells, which implied incomplete inhibition. Next, we performed similar assays by adding Y157WIAHQAVKIVFDSI171 peptide (25 µM) directly to the culture medium. As shown in 157WIAHQAVKIVFDSI171 specifically inhibited the NAGK–NudC interaction, thus affecting migration. Based on considerations of all observations, we propose that NAGK interacts with NudC and Lis1 on the dynein complex and promotes neuronal and non-neuronal cell migration.To examine the effects of the selected peptide . The “nuclear distribution” gene s fungus . NudC ge sapiens , and con sapiens ,39. The  sapiens , and its sapiens . This ev mutants ,43. HoweWe also present biological evidence regarding the colocalization of and the interaction between NAGK and the NudC–Lis1–dynein complex. First, we found that NAGK colocalized with NudC at the leading projections of cultured migratory neurons HEK293T cells) and in NPCs of the developing mouse cortex. A migratory phase of a neuron is characterized by a rostral position of the centrosome with respect to the nucleus in the migratory direction. In such migratory cells, we found MTs formed perinuclear cage-like structure at the rear and projecting into leading processes during migration, presumably to translocate nuclear MT structures to leading processes. The migratory phase was confirmed by DCX expression (a marker for migratory neurons) , and not3T cells Drosophila oocytes [Morris et al.  also rep oocytes . In acco oocytes ,34,49. A oocytes  proposed oocytes , which s oocytes ,29 and i oocytes . TherefoThe present study shows the functional significance of the interaction between NAGK with NudC and Lis1 in the dynein complex during cell migration. To verify these effects, we employed four different experimental migration models. First, we performed wound-healing assays , which sRing) and the other to dynein’s stalk, more specifically coiled-coil 1 (CC1) , the latter of which is required for the Lis1-induced weak MT-binding state. DeSantis et al. (2017) proposed that a single β-propeller binds at SiteRing and maintains dynein in a high-MT-affinity state by keeping the motor tightly bound to MT in preparation for cargo loading [Then, how does NAGK regulate dynein motor during cell migration? Dynein plays a central role in cell migration by pulling centrosomes and nuclei toward the (-) end of MT. Pulling a large cargo such as a nucleus at the molecular level probably requires the coordination of multiple dynein complexes. To date, Lis1 is the only dynein regulator known to interact directly with its motor domain. Lis1 may regulate dynein in two ways. First, at the motor and MT-binding side of the dynein complex, Lis1 may play a role in the loading of large cargoes, as multiple dyneins must be bound tightly to MT (+) ends. Lis1 has two quite different methods of regulating dynein because it can induce low or high affinity for MT . These d loading . This coSecond, on the tail side of the dynein heavy chain, NAGK would help transform the dynein complex to prepare it for cargo loading. The activation of dynein is accompanied by a structural change from the phi to the open form and light chain (LC)—heavy chain (HC) tail separation . The phiThe plasmids, including pDsRed2 vector, NAGK short hairpin (sh) RNAs and pDsRed2–NAGK, were used for transfection, as described previously ,27. AntiThe Institutional Animal Care and Use Committee of the College of Medicine, Dongguk University, approved all animal experiments  beforehand . On the The protein data bank (PDB) server was used for retrieving NudC (PDB id: 3QOR) and NAGK (PDB id: 2CH6) three-dimensional structures. The structures were fixed by adding hydrogen and correcting pH. The force field, Optimized Potential for Liquid Simulations (OPLS), was applied to minimize the energy of the structures ,60, usinYASARA Biosciences GmBH, Vienna, Austria) [+ and Cl− ions [Molecular dynamics simulation was conducted via YASARA dynamic software (Austria) , and theAustria) ,66,67, aAustria) ,68,69. WCl− ions . Energy Cl− ions ,72 and pCl− ions  and YASA157WIAHQAVKIVFDSI171 and L198GILTHLYRDF208) and NudC complexes were constructed from the lowest energy structures by free energy landscape analysis using Maestro Version 11.1.012. Peptide–protein complexes were also subjected to an additional 55 ns simulation using YASARA dynamic software following similar protocols. To select the peptide with better binding affinity, binding energy calculation was performed using the built-in MM-PBSA calculation. The mathematical details described previously [The NAGK peptides  was used for cells transfection with indicated plasmids by following the manufacturer’s guidelines.HEK293T and SH-SY5Y cells were grown on coverslips (coated by polylysine) in Dulbecco’s Modified Eagle Medium (DMEM) (Invitrogen) supplemented with Penicillin Streptokinase (1%) and fetal bovine serum (10%). LipofectamineFor pull-down assay, His-tagged NudC plasmid  was transiently transfected in HEK293T cells. The cells were lysed and collected after 48 h of incubation by using lysis buffer , 1% NP-40, 5% glycerol; pH 7.4) containing protease inhibitor cocktail , followed by washing with cold PBS. MagListo™ Ni-NTA magnetic silica resin  was allowed to bind with supernatant, which was then pulled down by following manufacturer’s instructions, as described earlier .The interested proteins were detected from the elution by using immunoblotting with respective antibodies, anti-NAGK , anti-DYNC1LI1 , or anti-DYNLRB1 , anti-Lis1  followed by 15% Tricine-SDS-PAGE separation and polyvinylidene difluoride (PVDF) membrane blotting. The blots were detected using an enhanced chemiluminescence (ECL) detection kit . To strip membranes, stripping buffer was used , and hybridization was performed with different primary and secondary antibodies.A wound-healing assay was conducted on 80% confluent cells, grown in 12-mm diameter coverslip (coated with polylysine), as mentioned earlier . A steri® 2000 with pDsRed2 or pDsRed2–NAGK plasmids at 50% of cell confluency. Then, transfected cells are incubated for 48 h until confluent. Then, a linear scratch was made by using a pipette tip, and cells were washed and transfected with 1 μg Y157WIAHQAVKIVFDSI171 peptide  via Pierce protein transfection reagent , as mentioned previously [For peptide inhibition assays, cells were transfected by lipofectamineeviously . Migration activity was quantified as the percentage of migrating cells moving with the migratory front. When peptide was added directly to the medium, cells were incubated in a serum-free medium for 4 h. A linear scratch was made by using a pipette tip and washed. Cells were incubated with either peptide (25 μM) or DMSO containing low serum (1% FBS) medium. Cell migration rates were quantified by expressing recovered areas as percentages to total damaged areas.2 flasks [® 2000 reagent (Invitrogen). Geltrex® matrix (Gibco) was used for transfection and live-cell imaging. The plated neurospheres were further grown for 48 h to attain differentiated cortical neurons in the medium containing 2% B27 supplement, 500 mM L-glutamine, and 1% penicillin–streptomycin with no growth factors. After culturing for 48–60 h, differentiated cortical neurons cultures were used for live-cell imaging and ICC.NPCs were cultured, as mentioned earlier . In brie2 flasks . For ICCIn utero electroporation (IUE) was conducted following the previously described method . After aCells were fixed by sequential fixed in paraformaldehyde/methanol, and ICC was carried out as previously described . AccordiAn Olympus microscope BX53 was used to take the fluorescence images containing DAPI staining. A Leica research microscope (DM IRE2)  was used for taking fluorescence images in n = 20) in three different experiments were measured. For the in utero electroporation study, numbers of transfected neurons in cortical plates and intermediate and ventricular zones were calculated and described as total neurons percentages. Counting was done in a blinded way, which was carried out by independent experienced investigators. Within each cohort, the animal selection was made from random cages at a random time and season. By using natural intelligence, the sample size was chosen depending on the data variability; however, not less than n = 5. In order to compare two groups, the Student’s t-test was used, while multi-group comparisons were made by one-way ANOVA with Duncan’s multiple comparison post hoc test. The use of parametric tests was verified by the normality test. The predictions were considered statistically significant when the p values were <0.05. p values of <0.0001 indicated a highly significant prediction. Statiscal Software, GraphPad Prism v 8.0  and SPSS 19.0  were used for statistical calculations, where the data are presented as means ± SDs.Three different experiments were considered for wound-healing assays. For counting, cells not more than 500 were considered from the various positions of each coverslip after transfecting for 48 h and 72 h, respectively. For in vitro migration assays, distances migrated by neurons (In summary, the present study shows NAGK interacts with NudC and Lis1 in the dynein complex and thus promotes cell migration. Our data suggest the possibility that NAGK recruits NudC and Lis1 to make a NudC–NAGK–Lis1 tripartite interaction in the dynein complex. Based on these findings, we propose a dynein activation model involving “bivalent” NAGK, where the small domain of NAGK interacts with DYNRB1 to transform the NDD of dynein HC from the phi to the open state, “pushing up” the LCs tailing. Alternatively, the large domain of NAGK recruits NudC and binds Lis1 to coordinate motor power at high loads, such as pulling a nucleus in N-C coupling during migration.


N theoretical model of carrier transport, capture, and escape processes. The combined experimental and theoretical results clearly indicate that those LEDs with graphene transparent conductive electrodes at p-junctions will have a shorter hole transport time along the lateral direction and thus a more efficient current spreading and a larger luminescence area. In addition, a shorter hole transport time will also expedite hole capture processes and result in a shorter capture time and better light emitting efficiency. Furthermore, as more carrier injected into the active regions of LEDs, thanks to graphene transparent conductive electrodes, excessive carriers need more time to proceed carrier recombination processes in QWs and result in a longer carrier recombination time. In short, the LED samples, with the help of graphene electrodes, are shown to have a better carrier transport efficiency, better carrier capture efficiency, and more electron-hole recombination. These research results provide important information for the carrier transport, carrier capture, and recombination processes in InGaN/GaN MQW LEDs with graphene transparent conductive electrodes.In this work, InGaN/GaN multiple-quantum-wells light-emitting diodes with and without graphene transparent conductive electrodes are studied with current-voltage, electroluminescence, and time-resolved electroluminescence (TREL) measurements. The results demonstrate that the applications of graphene electrodes on LED devices will spread injection carriers more uniformly into the active region and therefore result in a larger current density, broader luminescence area, and stronger EL intensity. In addition, the TREL data will be further analyzed by employing a 2- Low resistance and transparent Ohmic contact to p-type GaN are crucial to improve current injection and light extraction efficiency of GaN-based LEDs10. Although device performance can be improved by using Indium Tin Oxide (ITO) used as a transparent conducting layer (TCL), the exclusive use of these oxides becomes problems such as cost, rarity supply of indium, and low optical transmittance in the ultraviolet wavelength regions10. One the other hand, graphene has been considered a promising material to replace ITO in GaN-based LEDs as a transparent conductive electrode17, because of its high transmittance in the UV region, carrier mobility, and conductivity. It has been demonstrated that the transparent 3D graphene foam was very effective in current spreading to enhance the performance of blue LEDs11. However, due to high sheet resistance and the large work function difference between graphene and p-GaN, the use of graphene as a TCL adversely increases the operating voltage of LEDs14. In addition, the poor adhesion of graphene on the devices also problematically results in a low current injection into LEDs7.III-nitrides have become the key material for light emitting diodes (LEDs), laser diodes, and solar cellsI-V) relationship, and quantum efficiency are the common measurements to characterize the device performance of GaN-based LEDs. Although device performance of GaN-based LEDs with graphene transparent conductive electrodes has been shown to be improved, these measurements cannot quantitatively describe carrier dynamic behaviors. Time-resolved electroluminescence (TREL) measurement under electrical fast pulse excitation is a power tool to explore the dynamic EL behaviors of carrier injection, carrier transport, carrier relaxation into active region, and carrier recombination at the excited states in active region of LEDs19. From the results of TREL measurements, nitrogen-polar InGaN/GaN LEDs with the opposite polarity and nonpolar m-plane InGaN/GaN LEDs with a low polarization effect were shown to provide the advantages of more carrier injection, transport, relaxation, and recombination19. However, the effects of graphene transparent conductive electrodes on the carrier dynamic behaviors of carrier injection, carrier transport, carrier capture into active region, and carrier recombination of InGaN/GaN LEDs with graphene transparent conductive electrodes are not well understood, and many important issues are yet to be studied.Electroluminescence (EL), output power, current-voltage , spectrometer , calibrated integrating sphere, and power meter. Without an ohmic Ni/Au contact, an indium dot melting on the sample surface was used as a n-type contact for the probe station. For TREL measurement, a pulse generator (Tektronix AFG3152C) was used to generate 2.0–5.0 V, 0.5 μs pulse width, and 1 kHz repetition rate voltage pulses to the LEDs. The light output was focused and detected by a photosensor module containing a metal package PMT and a high-voltage power supply circuit (Hamamatsu H10721-210) operating directly on the surface of each LED. The same PMT voltages of the TREL measurement were applied for the LEDs. The parasitic capacitance in the test circuit would introduce the same RC delay for the two LEDs. The transit EL signals were recorded by a digital oscilloscope (Agilent DSO 6052 A) with a 500 MHz bandwidth. The overall resolution of TREL system is less than 2 ns. The detailed measurement was described in our previous study19.1, LED2, and LED3 in this work) were prepared for the studies of device characteristics and carrier transport properties by using EL images, EL spectra, I-V, output power, and TREL measurements. Subsequently, graphene was transferred onto the p-GaN layer of these three InGaN/GaN MQW LEDs . The same measurements were conducted on the LED1G, LED2G, and LED3G samples. Device characteristics and carrier transport properties of InGaN/GaN MQW LEDs without and with multilayer graphene were compared and analyzed.Three InGaN/GaN MQW LEDs without graphene electrodes (denoted as LEDp-GaN layer: (a) Graphene was grown on a copper sheet by a chemical vapor deposition (CVD). (b) Poly (methyl methacrylate) (PMMA) was spin-coated on the graphene/copper sheet. (c) The copper sheet was etched in a 1 wt. % (NH4)2S2O8 solution11. (d) The graphene with PMMA was transferred onto the p-GaN layer of the InGaN/GaN LEDs. (e) The PMMA layer was removed by acetone solution.Fig. 1, LED2, and LED3) and their counterparts with grapheme electrodes . Each inset in Fig. 1, LED2, and LED3 samples are brighter near the upper positive electrode. For nitride semiconductors, the electron mobility is fast than hole mobility2. With a higher electron mobility, the electrons transport more quickly into the MQWs near the positive electrode and wait for holes to recombine. Once the slow-moving holes transport and are captured into MQWs, electron-hole pairs will recombine and generate luminescence. In addition, stronger EL intensities and larger luminescence area of the LED1G, LED2G, and LED3G samples show that graphene exhibits a good current spreading characteristic to distribute the injection current more uniformly.Figure 1G, LED2G, and LED3G samples are all red-shifted. Because of indium aggregation or phase separation in InGaN alloys, the EL emissions come from the recombination of localized excitons in In-rich InGaN clusters which formed spatial potential fluctuations and localized states for trapping carriers6. As shown later, the current density of the LED1G, LED2G, and LED3G samples are all larger than those of the LED1, LED2, and LED3 samples, respectively. With a good spreading characteristic of graphene, more carriers can more efficiently transport into spatially distributed potential minimums  for recombination22. Hence, the red-shifted EL peak positions of the LED1G, LED2G, and LED3G samples are observed.Figure I) and output power as functions of applied voltage V for the LED1 versus(vs.) LED1G, LED2 vs. LED2G, and LED3 vs. LED3G samples, respectively. The currents of the LED1G, LED2G, and LED3G samples are all larger than those of the LED1, LED2, and LED3 samples, respectively. Although the graphene/GaN contact resistance and work function difference are both large, the current spreading characteristic of graphene distributes more current to inject into active region and would not degrade the electrical characteristics. The largest current density of the LED3G sample implies that the LED3G has the best graphene transparent conductive electrode as well as the best sample quality. Also, when the injected current is increased and the carriers are over populated. Hence, a blue-shift EL peak was observed in Fig. 1G, LED2G, and LED3G samples contribute to more output power. This characteristics shows that graphene acting as transparent conductive electrodes in InGaN/GaN MQW LEDs can improve device performance. From the better performance of LED1G, LED2G, and LED3G samples, the bonding between LED and graphene should be good.Figure 1, LED2, LED3, LED1G, LED2G, and LED3G samples, respectively. A stronger intensity, shorter response time, and steeply rising of the LED1G, LED2G, and LED3G samples imply a better carrier transport and carrier capture efficiency23. In the TREL results, the response time  states to the confined (quantum) states in the quantum-well region. A more detailed discussion on the physical meanings of 23.It should be noted that the rec as a function of applied pulse voltage for the LED1 vs. LED1G, LED2 vs. LED2G, and LED3 vs. LED3G samples, respectively. The effects of graphene transparent conductive electrodes on the carrier transport, capture, and recombination dynamics of InGaN/GaN MQW LEDs can be well revealed from these results. With the graphene transparent conductive electrodes, the transport times 1G and LED2G samples are slightly shorter in comparison with those of the samples without graphene. Meanwhile, the transport times 3G sample, due to its superior graphene quality, is much shorter than that of its without-graphene counterpart. In addition, a short transport time 1G, LED2G, and LED3G samples. In other word, due to the graphene electrode, more carriers transport in a larger luminescence area and consequently are captured more efficiently into the QWs. It should be noted that the response time obtained from the TREL and the transport time defined in the 2 N model roughly characterize the time span for carriers moving from the contact to the quantum-well region. Therefore, the injection efficiency is inversely proportional to the transport time23. As more carriers transport and are captured into QWs, more carriers will recombine in the QWs and have a longer recombination time 3G sample.Figure 2. When the holes and electrons were injected into the MQWs, due to their higher electron mobility, electrons will transport and be captured more efficiently into to the MQWs than holes. As a result, the p-junction becomes the dominant factor in determining the overall carrier injection and recombination efficiency.Based on the above observations, carrier injection, carrier transport, carrier capture, and recombination dynamic schemes were proposed in Fig. p-junction will expedite the transport processes of holes along the lateral direction and thus resulting a broader current spreading and a larger luminescence area. As schematically illustrated in Fig. 1G, LED2G, and LED3G samples have shorter transport and capture times, but longer recombination time than the LED1, LED2, and LED3 samples. The graphene transparent conductive electrodes can expedite carrier transport processes, shorten the transport time N theoretical model.As shown in Fig. N theoretical model of carrier transport, capture, and escape processes. The combined experimental and theoretical results clearly indicate that those LEDs with graphene transparent conductive electrodes at p-junctions will have a shorter hole transport time along the lateral direction and thus a more efficient current spreading and thus a larger luminescence area. A shorter hole transport time will also expedite hole capture processes and thus result in a short capture time. Furthermore, as more carrier injected into the active regions of LEDs, thanks to graphene transparent conductive electrodes, excessive carriers need more time to proceed carrier recombination processes in QWs and thus result in a longer carrier recombination time. The research results provide important information for the carrier transport, carrier capture, and recombination processes in InGaN/GaN MQW LEDs with graphene transparent conductive electrodes.In this work, InGaN/GaN MQW LEDs with and without graphene transparent conductive electrodes are studied with I-V, EL, and TREL measurements. The results demonstrate that the applications of graphene electrodes on LED devices will spread injection carriers more uniformly into the active region and therefore result in a larger current density, broader luminescence area, and stronger EL intensity. In addition, the TREL data will be further analyzed by employing a 2-Supplementary information.


The way an athlete focuses their attention when lifting a weight has the potential to influence strength development during training and performance outcomes during competition. The effects of attentional focus strategies during weightlifting tasks was investigated through a systematic review. Major databases  were searched using key terms relevant to attentional focus and weightlifting and reference lists of identified articles were also searched. Following screening, 16 articles were retained for analysis. The review showed that researchers have recruited experienced and novice weightlifters of both genders in their studies, although male experienced weightlifters are the most commonly studied demographic. Weightlifting tasks have varied from bench press, biceps curls, squats, and leg extensions with some studies using measures of force production against a force plate. The predominant manipulations have been between internal-associative and external-associative foci. An external attentional focus has shown to be beneficial in terms of movement economy as reflected in a variety of outcome measures. The results are interpreted within the framework provided by the Constrained Action Hypothesis and more generally the advantages of an external attentional focus for motor skill learning. An external focus of attention promotes automatic control of actions, thus preventing the motor system being constrained by conscious cognitive control. Implications for informing training programs for athletes and for advising athletes to maximize performance during competition are discussed. The action of lifting a weighted apparatus is ubiquitus in sport and exercise. It is used during training to develop muscle strength, muscle mass, and joint strength. It is is also a competitive sport in its own right, as reflected in its Olympic Games status and the formation of national and international governing bodies. The sport of weightlifting requires lifts of the snatch and the clean and jerk with athletes aiming to lift the heavest weight for their division during competition. Other competitive events, often referred to as powerlifting, require the deadlift, squat, and bench press. Weightlifting is also a key component of training for other sports and as part of a physical exercise program. In these situations, there are a multitude of different types of lifts according to the muscles required, equipment used, and the speed, duration, and complexity of the movements.The physical nature of weightlifting has naturally led to research on physical factors, such as physiology, biomechanics, diet, and injury. Comparatively less work has been conducted on the psychological processes associated with weightlifting. The psychology of weightlifting has been examined from various perspectives, including self-efficacy, intention, and self-regulation behaviors  and direction dimensions of Stevinson and Biddle . WiningeAttentional focus in weightlifting has been largely investigated from the attentional focus strategies of internal association and external association . This approach stems from the influential work by Wulf et al. demonstrating the performance benefits of an external attentional focus over an internal attentional focus in ski-simulator and balancing tasks  guidelines were followed for the literature search , the mean journal h-index was 86.33 , and seven journals were Q1 ranked. These citation metrics suggest that the journals that published this research were of moderate to high quality. The articles were coded by study characteristics , participant characteristics , and task characteristics (exercise/movement completed and equipment used).Following this selection process, a total of 12 articles from the database search, with a further four articles identified following the examiniation of the selected articles reference lists were obtained. As such, a total of 16 articles were included in the systematic review. The types of weightlifting tasks and equipment used in research on attentional focus strategies are shown in Lohse et al. , Lohse , and LohThe characteristics of the participants who have been studied in research are shown in Participants have tended to be experienced in weightlifting, although a sizeable portion of studies did not specify the participant experience level. Experienced participants are more likely to be well-practiced and to have develop automaticity in movements. Given the notion that an external focus of attention facilitates automatic motor processes  condition and that this is evidence for a beneficial effect of an external focus rather than a relative detrimental effect of an internal focus Wulf, . SimilarFurthermore, research has not always shown performance benefits with an external focus of attention. No differences between internal and external foci have been observed for time to failure or ratings of perceived exertion for a long duration force production task  can be achieved in practical terms. The first step in developing effective strategies is to identify what are the key elements that athletes should direct their attention to . For an internal focus, EMG recordings of muscles or movement sensors attached to the body can be used provide visual or auditory feedback to athletes. In addition, athletes should be aware that their own use of “psyching up” or self-talk might need to be modified to ensure that the appropriate attentional focus is used. For example, cue words like “strong” and “powerful” might inadvertently direct the athlete to focus their attention internally and should be modified accordingly during competition.The third consideration is how to tailor the approach to the specific context. In simple lifts, like the biceps curl, attentional focus instructions are relatively simple because the movement is constrained. However, compound lifts will involve multiple muscles and limbs. In addition, multiple component lifts like the clean and jerk involve discrete movements performed in sequence. Internal focus instructions might need to be varied according to the stage of the lift. Whether external focus instructions need to be varied across the lift remains to be determined. Based on the notion that external attentional focus benefits might result from both intramuscular efficiency and intermuscular efficiency . Research in our laboratory has shown that an external attentional focus has benefits to physical and psychological states during cardiovascular exercise tasks  attentional focus. Importantly, the studies conducted to date have typically been conducted in single-session designs. Thus, the long-term benefits of an external attentional focus remain to be determined. Similarly, transfer effects need to be established to determine whether beneficial attentional focus instructions practiced with one type of lifting exercise in the laboratory will transfer to real world training or competition or to other types of lifting exercises. In addition, it would be worthwhile to examine whether transfer occurs to similar sporting tasks. For example, some sports like shot put and discus, require a short-term maximal muscular effort. It would be informative to examine whether training in an external focus of attention transfers to these tasks  has emerged as a technology applied to sport (for reviews see Neumann, Weightlifting for physical conditioning or sport depends on many physical and psychological factors. Research examining cognitive strategies has shown that performance at the neuromuscular and behavioral level are influenced by the attentional foci that an athlete adopts. To maximize muscular efficiency, an external focus of attention is more optimal than an internal focus of attention or no specific focus in most cases. The challenge remains for researchers to further explore this effect and determine under which conditions it may be magnified. This information will assist in translational research that can allow athletes to reach a higher level of performance than might otherwise be possible.The author confirms being the sole contributor of this work and has approved it for publication.The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Interlayer coupling in graphene-based van der Waals (vdW) heterostructures plays a key role in determining and modulating their physical properties. Hence, its influence on the optical and electronic properties cannot be overlooked in order to promote various next-generation applications in electronic and opto-electronic devices based on the low-dimensional materials. Herein, the optical and electrical properties of the vertically stacked large area heterostructure of the monolayer graphene transferred onto a monolayer graphene oxide film are investigated. An effective and stable p-doping property of this structure is shown by comparison to that of the graphene device fabricated on a silicon oxide substrate. Through Raman spectroscopy and density functional theory calculations of the charge transport characteristics, it is found that graphene is affected by sustainable p-doping effects induced from underneath graphene oxide even though they have weak interlayer interactions. This finding can facilitate the development of various fascinating graphene-based heterostructures and extend their practical applications in integrated devices with advanced functionalities. Owing to the experimental and theoretical studies on 2D-vdW materials, unprecedented developments in fundamental science as well as the industrial fields have been accomplished. As 2D-vdW material-based components such as transistors, memories, energy harvesters, and sensors have shown immense potential for applications in advanced logic systems, extensive research efforts have been focused on overcoming the performance limits of the single 2D material8. Among the different types of 2D-vdW materials investigated to realize optimal devices, vertically combined structures are promising candidates to achieve high-efficiency logic components and overcome current performance limitations of the individual 2D-vdW materials9.Various two-dimensional (2D) van der Waals (2D-vdW) materials have been investigated for promising applications in futuristic electronic systems10, solar cells11, and light-emitting diodes12 have been introduced to improve and optimize the devices for a wide range of industrial applications. However, in the 2D-vdW heterostructures, interlayer coupling can usually cause unintended phenomena during the operation of the designed device. Therefore, understanding the physical and chemical interactions between the vertically combined vdW heterostructures is key to the design and modulation of device operation based on the requirements. For investigating the interlayer coupling effect in combined structures, graphene and graphene oxide (GO) have an advantage, as the intrinsic properties of both materials can be modulated by an external stimulus and/or chemical adsorption. Therefore, the interlayer interaction between graphene and GO films in a heterostructure can be clearly identified by comparing the experimental results with theoretical expectations.Owing to the atomically flat and well-defined clean interfaces, vertical hetero-structures allow unlimited combinations that can be optimized for various conceptual devices based on the demands. As a result, many devices such as graphene barristors15. Three types of field-effect transistor (FET) devices were fabricated in each area of the graphene, GO and graphene/GO sheets to compare the electrical and optical properties. The experimental strategies employed in this study can be utilized not only to reveal the physical origins of graphene doping effects in vdW hetero structures but also for designing new 2D vdW structures for applications in various conceptual electronic systems as well as their optimization for use in electrical and optical components.In this study, the interlayer coupling effect on the electrical charge transport and Raman spectroscopy measurements is investigated in vertically stacked graphene on GO films. The similarities and differences from the individual materials are carefully identified through experimental and computational studies. Using chemical vapor deposition (CVD) grown monolayer graphene and GO prepared via photochemical treatment, graphene/GO heterostructure was obtained by transferring graphene onto GO2/Si substrate. As shown, GO films are prepared by UV irradiation of the graphene film deposited on the SiO2/Si substrate. Excimer UV irradiation with a wavelength of 172 nm is used for oxidation at room temperature at ambient conditions within 1 min without wet chemical treatment  and Au (90 nm) are sequentially deposited to provide an electrical contact on FET devices. The three types of FET devices with transport channels denoted as graphene, GO, and graphene/GO are prepared as shown in Fig. Figure ent Fig. . Thereafate Fig. . The thiate Fig. . Three t17, the most conventional method does not employ UV-irradiation, but instead involves dispersion using filtered graphite oxide flakes18. In these methods, GO is obtained via several steps of chemical treatment. The process not only requires several hours for completion, but the treated surface is also covered with inhomogeneous functional groups such as hydroxyl (-OH), carboxyl (-COOH), and epoxide (-O-) groups. Because the electrical properties of CVD graphene can be easily modified by charged impurities or chemical components dispersed on the GO surface as well as the substrate, UV-irradiation technique is employed in this study to obtain a clean GO surface , broad G peak (~1595 cm−1), and discernible D + G peak (~2944 cm−1) are observed21. As shown in Fig. −1) of the GO sample is observed in comparison to that (1595.5 cm−1) of the graphene sample. Despite the changes in the Raman spectrum of graphene due to UV irradiation, the optical contrast of the graphene layer on SiO2 substrate did not change significantly, and the graphene was indistinguishable from GO under optical microscopy . The calculated peak positions of G, D′, and D″ peaks obtained by fitting are 1597.1, 1623.3, and 1513.5 cm−1, respectively. These results are intriguing, and several possible explanations have been suggested for the blue shift of G peak in GO. One explanation is based on the double bonds and the other on the D′ band. In theoretical calculations, the alternating pattern of the single-double carbon bonds within the sp2 carbon ribbons yields blue-shifted high-intensity Raman bands24. Other studies have suggested that the merging of D′ band (~1620 cm−1) can also be partially responsible for this blue shift. The presence of D′ band can be explained by the disorder-induced phonon mode above the G band due to crystal defects26.For a detailed analysis of this behavior, the Raman spectrum of GO was fitted with multiple peak functions in the 1500–1700 cm27. However, the typical Raman spectrum for the twisted bilayer graphene is not observed in the graphene/GO structure in the present study31. Thus, it is concluded that the observation of the summation of individual Raman spectra of the two stacked layers is a unique property of the vdW heterostructures of G and GO, without any interlayer interactions32.Next, the Raman spectroscopy results for the graphene/GO region were examined. Interestingly, for graphene/GO, the Raman spectrum appears to be a simple mathematical summation of those for graphene and GO. To confirm this observation, the Raman spectrum of the graphene/GO region was analyzed by comparing it to the mathematical summation of the spectra obtained from graphene and GO regions. As shown in Fig. VDirac), carrier density (n), mobility (µ), and resistance in CNP (RCNP) for each device are listed in Table VDirac, but the current level is significantly different by an order of magnitude. Both graphene and graphene/GO exhibit similar current levels, but wider transfer curve characteristics and higher Dirac point are observed for the graphene/GO device. To confirm the repeatability and reliability of these trends, additional FET devices were fabricated and characterized by back-gate-induced measurements. All devices showed the same tendencies with respect to variations in VDirac, current level, and I–V curve slope . VDirac is the Dirac point estimated at the conductance minimum of the graphene channel during the gate voltage (VG) sweep, n is the carrier density, and μ represents the mobility of graphene FET. A higher carrier density of GO in comparison to that of graphene is due to the functionalities on the surface of GO. Carrier density in graphene/GO is almost equal to the summation of the carrier densities in graphene and GO regions.The resistance of the transport channel is defined as Eq. 331\documRCNP as a function of VDirac distributions for each channel. Although the CNP position increases more than three times for graphene/GO in comparison to that for graphene and the resistance of GO is higher than that of graphene, no significant change is observed in the resistance of graphene/GO compared to graphene. Furthermore, the electrical properties of GO and graphene/GO exhibit excellent stabilities without any noticeable changes in the mobility and resistance for a year even when these are kept at ambient conditions.Figure 34 implemented in the Vienna Ab-initio Simulation Package (VASP) with a projector augmented wave (PAW)35 method, within the generalized gradient approximation (GGA) by Perdew, Burke, and Ernzerhof (PBE)36 theoretical calculations. Geometry optimization of the structures is carried out until the Hellmann–Feynman force acting on each atom is less than 0.01 eV/Å. We use 5 × 5 graphene and 5 × 5 graphene with 2 oxygens in the unit cell. The first Brillouin zone integration is performed using the Monkhorst–Pack scheme, and 5 × 5 × 1 k-point sampling for graphene on graphene oxide is used. Figure 38. Additionally, a Dirac cone-like feature is observed at the K-point with a very small gap (~0.05 eV) as shown in Fig. To explain the high doping effect of G/GO, first-principles calculations were performed for the structure of graphene/GO using density functional theory (DFT)In conclusion, the graphene/GO structure is the thinnest vdW heterostructure known, which enables effective p-doping without chemical bonding. Raman spectroscopy measurements and electrical transport analysis, together with the corresponding simulations of the graphene/GO structure, confirm that there is no chemical bonding between graphene and GO layers. However, the electrons can flow from the graphene sheet owing to the difference in charge density, which is due to the presence of oxygen groups in GO, exhibiting a p-doping effect in the graphene layer. Additionally, these effects are observed for a long time under ambient conditions, affording almost perpetual p-doping effect on the surface of graphene deposited on GO. We suggest that the monolayer GO can be used as the thinnest hole-dopant supplier sheet for graphene without affecting its resistance value. Furthermore, by substituting the oxygen groups of GO by n-type-inducing functionalities, a graphene p-n junction can be obtained in a facile manner. We believe that our work could be stepping-stone for realizing various conceptual devices based on partial doping distributions using the 2D heterostructures and further could be contribute to engineering and modulating the electronic and optoelectronic applications.4 and H2 (1:2) gas mixture for 20 min. The graphene on the Cu film was spin-coated with poly methyl methacrylate . Cu foil was etched by floating on 0.1 M ammonium persulfate ((NH4)2S2O8) aqueous solution. After rinsing several times with deionized water, the graphene film was transferred onto the SiO2/Si substrate. Then, the PMMA layer was removed using acetone, followed by rinsing and drying with isopropyl alcohol (IPA) and N2, respectively.Monolayer graphene was grown on a Cu foil  at 1000 °C via tube-type thermal CVD (T-CVD) with a flow of CH2 was used for oxidation at room temperature at ambient conditions without any wet chemical treatment. Optimized UV irradiation time is determined by Raman analysis.  using a diode laser with a wavelength of 532 nm. The laser power was set to 1 mW to prevent any destructive effects on graphene and GO atomic layers. The laser source was vertically exposed onto the device surface through a ×100 objective lens and the position of the sample was controlled within micrometer accuracy by a piezo stage.−6 Torr. Si and SiO2 in the SiO2/Si substrate act as the gate and gate insulator, respectively. The I-V curves were obtained by measuring the current flow in the channels of the FET devices while controlling the bias voltage and gate voltage sweep.The I-V characteristics of the devices were investigated by electrical transport measurement using a vacuum probe station connected to Keithley 4200-SCS parameter analyzer. All electrical measurements were performed under a high vacuum of below 10Supplementary information.


We consider the effect of atomic impurities on the energy spectrum and electrical conductance of graphene. As is known, the ordering of atomic impurities at the nodes of a crystal lattice modifies the graphene spectrum of energy, yielding a gap in it. Assuming a Fermi level within the gap domain, the electrical conductance diverges at the ordering of graphene. Hence, we can conclude about the presence of a metal–dielectric transition. On the other hand, for a Fermi level occurring outside of the gap, we see an increase in the electrical conductance as a function of the order parameter. The analytic formulas obtained in the Lifshitz one-electron strong-coupling model, describing the one-electron states of graphene doped with substitutional impurity atoms in the limiting case of weak scattering, are compared to the results of numerical calculations. To determine the dependence of the energy spectrum and electrical conductance on the order parameter, we consider both the limiting case of weak scattering and the case of finite scattering potential. The contributions of the scattering of electrons on a vapor of atoms to the density of states and the electrical conductance of graphene with an admixture of interstitial atoms are studied within numerical methods. It is shown that an increase in the electrical conductance with the order parameter is a result of both the growth of the density of states at the Fermi level and the time of relaxation of electron states. We have demonstrated the presence of a domain of localized extrinsic states on the edges of the energy gap arising at the ordering of atoms of the admixture. If the Fermi level falls in the indicated spectral regions, the electrical conductance of graphene is significantly affected by the scattering of electrons on clusters of two or more atoms, and the approximation of coherent potential fails in this case. Modifications of graphene with impurities, defects, and chemical functional groups are of increasing interest, as they change the physical properties of graphene and make it a basic system, generating a new class of functional materials. Such materials can be supposedly used in nanoelectromechanical systems, systems of accumulation of hydrogen, etc. as competitors of silicon in electronic devices, though the quasirelativistic spectrum of charge carriers in graphene hampers its application, for example, in field transistors due to the absence of a gap in its spectrum. However, it is worth noting that the impurities can induce the appearance of such a gap.Indeed, within the self-consistent meta-gradient approximation and the method of projection of adjoint waves , the numSimilar calculations for graphene with impurities of aluminum, silicon, phosphorus, sulfur, boron, nitrogen, and lithium were executed in works ,4, whereIt is clear that the numerical calculations should be supported by a simple but adequate model presenting the exact analytic solutions. The theory of the modification of the spectrum of graphene caused by an increase in the concentration of point impurities was developed in works ,6,7, wheThe Kubo–Greenwood quantum-mechanical formalism in the Lifshitz one-band model was applied in ,11,12,13We note that, having the Fermi level falling in the gap domain, the velocity of an electron can lower its speed on such a level. This leads to a decrease in the mobility of electrons and in the electrical conductance, which can worsen the functional characteristics of graphene.Introducing the notation  in Ref.  that a gIt is worth indicating the different nature of a gap in the energy spectrum of graphene related to edge effects. Work  presentsIn recent times, several tens of works have been published on the influence of various types of deformations on the electron properties of  graphene . The reThe goal of the present work is to clarify the nature of the influence of the ordering of a substitutional impurity on the appearance of a gap in the energy spectrum and on the electric conductance of graphene.The conclusions in work  were basIn the present work, we will consider the interconnection between a change in the electrical conductance, changes in the energy spectrum, and the decay time for electron states under the ordering of impurity atoms in graphene.The Hamiltonian in the Lifshitz one-electron strong-coupling model describing the one-electron states of graphene doped with substitutional impurity atoms can be presented in the following form :(1)H=∑niLet us add to and subtract the translationally invariant operator The formula for the coherent potential will be given below.z, is defined asThe retarded Green’s function of graphene, which is an analytic function in the upper half-plane of values of the complex energy T-matrix can be presented in the form of an infinite series [I is the identity operator. A Green’s function satisfies the equatione series :(6)T=∑n1The terms of Equation (6) describe the processes of multiple scattering of electrons on clusters comprising one, two, three, etc. scattering centers. In work , it was γiε , as the Neglecting the contributions of the processes of scattering on clusters of three or more atoms, which are small due to the parameter ing form :(9)gε=1T = 0) as [Using the Kubo–Greenwood formula  and negl = 0) as (10)σαβ=The operator of the electron velocity projection integral  and rnj μ is determined from the relationThe Fermi level In Equations (9) and (10), In Equations (9) and (10), The probabilities are determined by the interatomic pair correlations 0iBB via ,28(16)PHere, The coherent potential can be determined from the condition equation (18)σi=〈Setting Solving the system of Equations (11) and (18), we find the values of the coherent potentialIn the limiting case of weak scattering olutions . It was Equation (15) implies that the maximum order parameter At the electron concentration n occurs .At the electron concentration ameter η . As the We recall that the contributions of the processes of the scattering of electrons on clusters to the density of states and to the electrical conductance decrease and are guided by some small parameter γiε , as the The parameter the form (22)γiε=Using formula ained in  in the lThe parameter 0iε/dε→∞ , whereasxxσ·d enters the formula for the electrical resistance of a graphene layerl is the length of a graphene layer along the axis x, and L is the layer width. Here, x is directed from a carbon atom to its nearest neighbor. The values of xxσ·d are given in units of Thus, the processes of scattering on clusters give a significant contribution to the density of states at the energies of electrons lying in interval (Equation (23)). The product η, we consider both the limiting case of weak scattering, To establish the nature of the dependence of the electrical conductivity η tends to its maximum value, If the order parameter For the three-dimensional crystals with a simple lattice in the approximation of effective mass, Equation (25) with the corresponding g(ε) by Equation (9) at the substitutional impurity concentration In It is seen from g(ε) of graphene, which is calculated in the approximation of coherent potential according to the first term in Equation (9). The dotted curve gives the density of states g(ε) calculated with regard to the processes of scattering on the pairs of atoms located in the limits of the first coordinate sphere in the case of the completely disordered arrangement of impurity atoms, g(ε), calculated with regard to the processes of scattering on the pairs of atoms in the limits of three coordinate spheres and in the limits of ten coordinate spheres, practically coincide with the results of calculations that consider the scattering on the pairs in the limits of the first coordinate sphere. Thus, we may conclude that the domain of electron states of an impurity in graphene in the model under study is spatially bounded by the first coordinate sphere. In g(ε) and the electrical conductance xxσ(μ) as functions of the energy ε and the Fermi level μ, respectively; d means the thickness of a graphene layer. The calculations of g(ε) and xxσ(μ) are carried out by Equations (9) and (10). The values of the energy ε and the Fermi level μ are given in units of the energy zone half-width In δ/w=−0.2 , and δ/wδ/w=−0.6 . g(ε) = 0 (xxσ(μ) for the Fermi level located in the gap is equal to zero. For the Fermi level outside the gap, the electrical conductance of graphene is nonzero and increases with the density of states on the Fermi level.g(ε) = 0 a. The elAs distinct from the above-described limiting case of weak scattering ng δ/w≪1 .xxσ on the scattering potential η, we present the dependence of the electrical conductance of graphene xxσ on the order parameter of impurity atoms η for different values of the scattering potential μ(η) calculated by Equation (14) lies to the right of the energy gap. In μ(η) as a function of the order parameter of an impurity η. In ig(μ) at the Fermi level on the order parameter of an impurity η; i = 1, 2 is the number of a sublattice. η. With the purpose to clarify the character of the dependence of the electrical conductance η. It is seen from xxσ agree qualitatively with the formula obtained in the limiting case of weak scattering xxσ on the ordering parameter η. We have considered such values of concentrations and scattering potentials, at which the Fermi level lies in the vicinity of the Dirac point, as well as outside it. The numerical results presented in ng δ/w≪1  and withng δ/w≪1 , on the η tends to the maximum value, As the order parameter g(ε) calculated with regard to the processes of scattering on the pairs of atoms located in the limits of three coordinate spheres and in the limits of ten coordinate spheres practically coincide with the results of calculations involving the scattering on the pairs located in the limits of the first coordinate sphere. Thus, we may conclude that the domain of electron states of the impurity in graphene in the model under consideration is spatially bounded by the first coordinate sphere. We showed the existence of domains with localized extrinsic states on the edges of the energy gap arising at the ordering of atoms of the admixture. If the Fermi level falls in the indicated domains, the processes of the scattering of electrons on clusters consisting of at least two atoms contribute essentially to the electrical conductance of graphene, and the approximation of coherent potential fails in this case.We note that values of the density of states and the electrical conductance of graphene cannot be used, if the Fermi level falls in the interval (Equation (23)) of energies at the gap edges. The values of the density of states η and the difference in the scattering potentials We have established that, at the ordering of impurity atoms, a gap appears in the energy spectrum of graphene. Its width depends on the order parameter In the limiting case of weak scattering At the electron concentration xxσ increases with the order parameter If the Fermi level lies outside the gap, the electrical conductance xxσ of graphene with the order parameter η of impurity atoms is caused by an increase in the density of states at the Fermi level, An increase in the electrical conductance


Unlike graphene, penta-graphene exhibits a non-zero bandgap, which opens the possibility of its use in optoelectronic applications. However, as the observed bandgap is large, gap tuning strategies such as doping are required. In this work, density functional theory calculations are used to determine the effects of the different number of line defects of substitutional nitrogen or silicon atoms on the penta-graphene electronic behavior. Our results show that this doping can induce semiconductor, semimetallic, or metallic behavior depending on the doping atom and targeted hybridization (sp2 or sp3-like carbons). In particular, we observed that nitrogen doping of sp2-like carbons atoms can produce a bandgap modulation between semimetallic and semiconductor behavior. These results show that engineering line defects can be an effective way to tune penta-graphene electronic behavior.Penta-graphene is a quasi-two-dimensional carbon allotrope consisting of a pentagonal lattice in which both  This carbon allotrope that is composed of a hexagonal lattice was demonstrated to possess several exciting features, such as high electrical and thermal conductivity and large mechanical resistance that are aimed at developing the next generation of organic optoelectronic devices4. However, when it comes to optoelectronic applications, graphene has a zero bandgap, which precludes its use, for instance, as active material in solar cells. To overcome this issue, gap opening strategies have been developed7 including the cutting of graphene sheets into graphene nanoribbons8, the adsorption of H-adatoms9 and the use of dopants12. Recently, the effects of such techniques have also been studied in similar 2D materials such as arsenene14, by means of first principle calculations.Research on 2D materials has gained much attention since the discovery of graphene15. The former makes use of the spin coating of dopant containing solutions so that charge transfer between graphene and dopant may take place. Dry doping strategies, on the other had, include the electrostatic field doping method, which consists on the application of an electric field perpendicular to the graphene sample. This method, however, cannot be applied to single layers of graphene. A more appropriate strategy in the context of this work is the atom substitution method, which can be performed by means of thermal treatment or plasma doping, for instance.When it comes to doping strategies, these are often divided into wet and dry doping methods16, and carbon nanotubes17. Recently, another allotrope was proposed named penta-graphene18  produce significantly different results in terms of electronic behavior. Silicon doping allows us to tune the bandgap when replacing sp3-like carbons and produces metallic behavior when replacing sp2-like ones. Nitrogen doping replacing sp3-like carbons results in a transition from semiconductor to semimetallic to a metallic character. Nitrogen doping replacing sp2-like carbons produces an alternating behavior between semimetallic and semiconductor depending on the number of dopants. These results indicate that engineered line defects can be a very effective way to tune penta-graphene electronic behavior.Herein, we carried out density functional theory (DFT) calculations to address the effects of the systematic substitutional doping of either see Fig. . As to tsp3 or sp2-like carbons forming engineered line defects. The cases of 1 up to 7 line defects were considered. In this sense, Fig. sp3 case, which is similar to the sp2 one. Figure In the present work, we investigated the electronic and structural features of penta-graphene lattices with substitutional doping (N or Si) either at Significant structural differences take place in the morphology of the resulting doped structures. For the nitrogen cases, an overall decrease in bond length values was observed, as presented in Fig. 21. We have obtained a similar value, as shown in Fig. sp3 cases for nitrogen  behavior, as can be seen in Fig. N, semiconducting properties are obtained with almost direct bandgaps that decrease as N grows larger from 2.4 eV for N = 0 to 0.6 eV for N = 6. In contrast, for odd values of N, the valence band maximum (VBM) touches or surpasses the Fermi levels. However, the DOS near the Fermi level is very small, increasing progressively with N. This behavior can be better visualized in the PDOS plots of Fig. N nitrogen-doped penta-graphene lattices display a semimetallic character, with carbon p orbitals being mostly responsible for the DOS in the vicinity of the Fermi level.In terms of electronic structure, nitrogen and silicon doping produce completely different results. Interestingly, for the N values, the structures become fully metallic, as shown in Fig. sp2-like carbons is not as effective as in cases of nitrogen doping regarding decreasing the bandgap value.Silicon doped penta-graphene structures, on the other hand, possess semiconductor properties only for N = 1 or N = 2, with a fast transition to bandgap closing. For larger sp2 doping instead of sp3 one is the effects on the structural stability of the doped structures. In Fig. Ecoh) values for all doping scenarios. The cohesive energy is the difference per atom between the entire system energy and the sum of the individual energies of its constituents. It is, therefore, associated with the stability of the system. Such a quantity is evaluated by the following expression:Etotal is the total energy of the system. ND and NC are the number of dopant and carbon atoms of the system, respectively, and Ntotal = ND + NC. ED and EC are the energies of isolated dopant and and carbon atoms, respectively.An important advantage concerning the sp3 and sp2 results, respectively. It can be seen from this figure that for both sp3 and sp2-like carbon doping, the effects on cohesive energy are similar for N and Si dopants. However, whereas sp3-like carbon doping increases the cohesive energy from −8.0 eV/atom to −6.5 eV/atom, the corresponding increase in the case of sp2-like carbon in less than 1.0 eV/atom.Figure Finally, we present the charge transfer analysis for all the modeled systems studied here. Figure 28 along with the DZP30, basis set. Relativistic pseudopotentials parameterized within the Troullier-Martins formalism were also considered31. These combined approximations can accurately describe the magnetic and electronic properties of materials composed of atoms with many electrons. All the calculations were performed considering spin polarization. For the bands and density of states calculations, Monkhorst pack grid of 21 × 21 × 3 was used32. A mesh cutoff of 200 Ry was chosen as a parameter for our calculations33. The force criteria convergence was 0.001 eV/Å. In order to establish a good compromise between the accuracy of our results and computational costs, the tolerance in the matrix density and total energy was set to 0.0001 and 0.00001 eV, respectively. All calculations were performed with the SIESTA software suite35.DFT calculations were carried out within the Generalized Gradient Approximation (GGA) scheme as proposed for Perdew, Burke, and Ernzerhof (GGA/PBE)sp3 or sp2-like carbons. Regardless of the type doping, for the nitrogen cases, we observed an overall stiffening of the penta-graphene structures. On the other hand, for the silicon doping cases, we observed only the stretching of Si-C bonds and compression of the remaining C–C bonds.In summary, we have carried out DFT calculations to assess the changes in the structural and electronic properties of penta-graphene lattices resulting from selective N and Si doping (engineered line defects) of either sp3-like carbons preserves the penta-graphene semiconductor character. The smallest observed bandgap value was 0.8 eV (2.4 eV for pristine penta-graphene) for the 4 line defect case. For a larger number of line defects, the bandgaps increase again. On the other hand, for Si doping sp2-like carbons, the result is a fast transition to metallic behavior.From an electronic structure perspective, both the doping type and doping atom selection produce significantly different results. Silicon doping of the sp3-like carbons, the doping results in a progressive changes from semiconductor to metallic behavior. For the case of 1 line defects, the doped penta-graphene structure becomes an n-type semiconductor with a 1.5 eV bandgap. For 2 and 3 line defects, the bandgap closes, but the density of states near the Fermi level goes to zero, giving the material a semi-metallic character. From this point on, further doping leads to true metallic behavior.Nitrogen doping produces more interesting results. For the sp2-like carbons, we observed a bandgap modulation behavior . For even numbers of line defects, the bandgap decreases with the number of line defects. In contrast, for odd numbers of line defects, a semi-metallic behavior is observed, combining zero bandgap with near-zero density of states at the vicinity of the Fermi level. Finally, the cohesive energy values indicate that doping the sp2-like carbon affects less the structural stability of the resulting doped structures than sp3-like carbon ones.For the nitrogen doping of 36 have demonstrated the creation of graphene and hexagonal boron nitride (h-BN) in-plane heterostructures with controlled domain sizes by using lithography patterning and sequential CVD growth steps. By employing this approach, the shapes of the graphene and h-BN domains were precisely controlled, and sharp graphene/h-BN interfaces were created. In this way, we believe that such an approach can be employed to yield our proposed model lattices. We hope the present work can stimulate further studies along these lines.These results indicate that selective doping of penta-graphene structures through engineered line defects can be an effective tool to tune their electronic behavior, being possible to create structures that vary from large bandgaps through semiconductors and even metallic or semimetallic ones. Importantly, Liu and coworkersSupplementary information.