In this study, some features of molecular dynamics simulation for evaluating the mechanical properties of a Ni/graphene composite and analyzing the effect of incremental and dynamic tensile loading on its deformation are discussed. A new structural type of the composites is considered: graphene network (matrix) with metal nanoparticles inside. Two important factors affecting the process of uniaxial tension are studied: tension strain rate (5  The remarkable properties of crumpled graphene make it an ideal candidate for high-performance structures ,2,3 sincImprovement of the strength of metals is of high importance for the development of structural materials and carbon polymorphs are shown to be a prospective candidates for such enhancement . The firIt was shown that several important factors for superior mechanical properties of metal/graphene composites can be taken into account. For example, if the graphene flakes are agglomerates, it can decrease the mechanical characteristics of the composite ,25,26. TMolecular dynamics (MD) simulation is one of the most widely-used numerical tools in the studies of physical and mechanical properties of nanomaterials since it provides information not readily accessible experimentally. A number of different processes have been explored in carbon-metal systems by MD, including deformation and fracture ,32,33,34Different methods can be used to apply active deformation to the investigated atomic system. One of the key points is to ensure that the applied deformation scheme follows the basic concepts of continuum mechanics such as energy conservation. The chosen deformation scheme can affect the final results, especially when tension and fracture of the sample are considered, and the search for a better deformation technique is the motivation of this paper.In the present work, the methodology for MD simulation of plastic deformation of a Ni/graphene composite is presented. Two deformation schemes  and two very important parameters (strain rate and simulation temperature) are taken into account.In the present work, the CG/Ni composite system comprises 19,136 atoms, including 2 parts: the carbon matrix and metal nanoparticle fillers, which are brought together, as shown in A. Note that in previous studies [A, the precursor structure is not totally random, and very ideal with round nanoparticles and perfectly rolled graphene flakes, which is far from realistic crumpled graphene. However, the further deformation-temperature treatment allows for finding much more real configurations. The dimensions along x, y, and z directions are 100 Å, 101 Å, and 85 Å, respectively. A more detailed description of the formation of the starting configuration of the Ni/graphene composite is presented in [The starting configuration, which is not yet a composite, but just the precursor—a system of graphene flakes with Ni nanoparticles inside each flake—is shown in  studies ,40,41 itented in ,43.B. At first (A), flakes are rotated for the same angle, but after annealing GFs are crumpled in a different way, structural elements (flake with nanoparticle inside) have different shapes and sizes, and the distance between different GFs was changed during temperature treatment as well as the pore size in the structure. This process should provide the fabrication of the composite with low anisotropy. Moreover, it is known that at temperatures lower than 600 K, covalent bonds in the basal plane of graphene are very strong. Thus, even during annealing, only edge atoms of graphene flakes can interact with the edge atoms of neighboring graphene flakes. During energy minimization or annealing, only changes in the shape of graphene flakes can be observed as well as changes in the equilibrium distance between neighboring flakes.After creating the initial configuration, three different treatment routes are applied, as shown in At first , stage Ax, y, and z) is the same and equal to 61 Å. At this stage, the deformation of the structure occurs due to a decrease of the free volume (pores and voids) between the structural elements and also a slight compression of graphene flakes and Ni nanoparticles (see C). However, nickel nanoparticles do not lose their crystal structure during the pre-compression process and remain in the internal cavities of graphene flakes. During pre-compression, the sample was compressed to about 40% in the x and y directions, and to 28 % in the z direction in comparison with the starting configuration.After exposure of the sample at 300 K, an approximation to quasistatic compressive loading in each deformation increment is conducted in two steps, including (i) compression during 27 ps to eliminate the large pores in the structure and (ii) compression to the composite state. The time of compression depends on the porosity of crumpled graphene: pre-compression can be finished when neighboring GFs start to interact and stress in the system becomes non-zero. Compression to the composite state took place before maximum density is achieved in the system. The time of compression depends on the structural peculiarities. The compression rate in the loading process is 5 cles see , stage CD). This temperature is enough to facilitate the formation of new valent bonds between graphene flakes, but not enough to melt Ni nanoparticles [The second step of deformation—high-temperature compression–is applied at 1000 K to obtain the final composite state see , stage Darticles ,41. The After high-temperature compression, the structure is relaxed to minimize the internal elastic stresses that appear during the preparation of the Ni/graphene composite. It should be noted that in early works ,41,42,43To apply the load to the system, boundaries of the simulation cell are moved with the given strain rate, which is the displacement-control method. In this work, two types of a tensile load of a Ni/graphene composite are considered: dynamic and incremental uniaxial tension . For theease see .x-direction is performed to apply two deformation mechanisms. A constant engineering strain rate of two values, 5 n leads to the same increase in the time of deformation of the composite. For example, the incremental deformation time The strain-controlled uniaxial tension in the The simulation model was developed based on the Adaptive Intermolecular Reactive Empirical Bond Order (AIREBO) for the carbon system  and the The functions that describe the interactions between Ni and C atoms are referred to the Morse potential with the parameters C system ,55. The ained in . The potained in ,41,54. Hained in ,58.MD simulations are conducted using the isothermal-isobaric (NPT) ensemble via a Nose–Hoover thermostat. The equations of motion were solved using a velocity-Verlet algorithm with a time step of 1.0 fs. Periodic boundary conditions are applied along all three directions. During uniaxial tension the volume of the simulation cell remains constant, i.e., as the length of the composite increases in the one direction, its size is correspondingly and anisotropically decreased in the other two directions to maintain the total volume of the system.An increase in the exposure time during the creation of the composite (from 20 ps to 200 ps) did not change the obtained results. Stress–strain curves are obtained by carrying out at least two modeling processes for each composite’s deformation mode and structural state. The simulation time for dynamic tension at a strain rate The snapshots of the MD results are processed by the Visual Molecular Dynamics package . This isFirst, the effect of the tension strain rate on the mechanical properties of the fabricated Ni/graphene composite is considered. The system temperature for these simulations is maintained at 0 K. Before uniaxial tension is applied, the structure is relaxed to minimize internal stresses.ates see . For ε>0gher see , but the0.74 see c. At thasite see b,c. HoweIIn εUTS see . The eloture see b,c. The The effect of temperature on the mechanical properties of Ni/graphene composite is studied for both methods of uniaxial tension at a strain rate of In ture see a, while This deformation mechanism is not observed at 0 K, since thermal fluctuations of atoms play a key role in the formation of long carbon chains. At 300 K, the hexagonal graphene lattice is easily transformed to form long covalent carbon chains. Carbon chains are also formed during low-temperature tension of the composite, but chains are shorter than at 300 K see b,c, and aterials ,63,64. NThe ultimate tensile stress and strain of the composite decreased with temperature increase, which is associated with a decrease in the strength of interatomic interaction due to thermal fluctuations of atoms. The resulting carbon chains under uniaxial tension b,c are dgate see b,c.The material properties can considerably depend on the direction in which these properties are measured, which is anisotropy. As it was shown for Ni/graphene composite, fabrication of the composite with a more homogeneous structure enhanced mechanical properties . The strx-axis, however, plasticity under these deformation conditions is the lowest, while when stretched along the y-axis, the composite has the maximum plasticity. At the same time, at the strain x and z-axes, the deformation occurs as a result of the formation of long carbon chains with their subsequent fracture. Such a difference in the strength of the composite is primarily associated with the initial structure of the Ni/graphene composite  of the obtained composite are 219 GPa  give close results on ultimate tensile strength and Young’s modulus. The formation of long carbon chains occurs faster under incremental uniaxial tension, and therefore the composite is broken faster. It can be concluded that the chosen strain rate should be reasonably small to obtain physically correct results, but not too small, which enlarges the simulation time. For such composite material, a strain rate of A simulation approach to study Ni/graphene composite under uniaxial tension at different simulation conditions by means of MD has been presented. Incremental and dynamic tension techniques, strain rate, and simulation temperature are chosen as the key factors in order to obtain a satisfactory simulation methodology for the simulation of metal/graphene composites. It is shown that a decrease in strain rate, as well as simulation at room temperature for such structures, can give lower ultimate tensile strength under uniaxial tension since it allows for slower structural transformations. However, dynamic and incremental mechanisms of tension lead to similar mechanical behavior, though the incremental regime of the simulation is much longer.Overall, the strengthening of the composite with a graphene network composed of graphene flakes is shown. The route for composite fabrication plays a key role in the formation of the composite with low anisotropy. The considerable difference in the composite strength under uniaxial tension along three directions is shown. However, in  it was s


In view of the good adsorption properties of graphene and carbon foam, they were combined to achieve the optimal matching of microstructures. Taking mesophase pitch as a raw material, pitch-based carbon foam was prepared by the self-foaming method. Graphene gel was prepared as the second phase to composite with the carbon foam matrix; graphene-modified, pitch-based carbon foam composites were finally obtained. Graphene gel was dispersed in the rich pore structure of carbon foam to improve its agglomeration and the porosity, and the active sites of the composite were further increased; the adsorption properties and mechanical properties of the composites were also significantly improved. The microstructure and morphology of the composites were studied by SEM, XRD and Raman spectroscopy; the compressive property and porosity were also tested. Methylene blue (MB) solution was used to simulate a dye solution for the adsorption test, and the influence of the composite properties and MB solution on the adsorption property was studied. Results showed that the compressive strength of the composite was 13.5 MPa, increased by 53.41%, and the porosity was 58.14%, increased by 24.15%, when compared to raw carbon foam. When the mass of the adsorbent was 150 mg, the initial concentration of the MB solution was 5 mg/L, and the pH value of the MB solution was 11; the graphene-modified carbon foam composites showed the best adsorption effect, with an adsorption rate of 96.3% and an adsorption capacity of 144.45 mg/g. Compared with the raw carbon foam, the adsorption rate and adsorption capacity of the composites were increased by 158.18% and 93.50%, respectively. With the continuous maturity of industrialization and economic development, the pollution of air, water and soil waste has become increasingly serious, especially water pollution, which has caused great impact on the human living environment and has become a key problem to be solved . Accordi2/g, and the carbon dioxide adsorption capacity is 12 mol/kg. Feng et al. [Graphene is an excellent adsorption material due to its large specific surface area and unique, two-dimensional lamellar structure ,25. The g et al.  preparedg et al.  preparedBased on the broad application potential of graphene and carbon foam in the adsorption field, and taking full advantage of their adsorption properties, graphene-modified, pitch-based carbon foam composites were synthesized in this study. Using mesophase pitch as a raw material, the self-foaming method was adopted to prepare carbon foam, and graphene gel was prepared as the second phase to composite with the carbon foam matrix. On the basis of the good adsorption performance of carbon foam, by increasing the material porosity and the number of surface active sites, graphene gel was dispersed in the rich pore structure of carbon foam to improve its agglomeration, which significantly improved the adsorption performance and mechanical properties of the composite and formed an optimized adsorption system. Test results showed that, when the adsorbent mass was 150 mg, the initial methylene blue (MB) concentration was 5 mg/L, and the pH value of MB solution was 11; the prepared graphene-modified, pitch-based carbon foam composite showed an adsorption rate of 96.32% and an adsorption capacity of 144.45 mg/g for MB, which reveals a wide application prospect in the field of water pollution treatment.Coal tar pitch as carbon foam precursor was purchased from Koppers Carbon & Chemical Co., Ltd. ; flake graphite as the raw material of graphene was purchased from Nanjing XFNANO Materials Tech Co., Ltd. .3, added 50 mL of concentrated sulfuric acid into a beaker containing a mixture of flake graphite and NaNO3 and stirred it magnetically in a water bath for 30 min. Then, we added 6 g of KMnO4 slowly into the beaker, put the solution in water bath at 35 °C for 1 h, added 80 mL of distilled water slowly and heated and stirred continually at 95 °C for 0.5 h. Then, we added 80 mL of distilled water when the water bath decreased to room temperature and added 6 mL of H2O2 after stirring for 15 min; the solution turned bright yellow, and we adjusted the pH value of the solution to 7. Then, graphene oxide solution was obtained. We added L-cysteine to the graphene oxide solution and treated it ultrasonically for 2 h; the mass ratio of graphene to L-cysteine varied from 0.5 to 2.0 and then we put the solution in a water bath at 95 °C for 1 h to obtain graphene gel.Graphene oxide (GO) was obtained by modified Hummers’ methods. First, we took 1 g of flake graphite and 1 g of NaNOCarbon foam was prepared from coal tar pitch by self-foaming method. First, coal tar pitch was thermally condensed to prepare mesophase pitch. An 8 g amount of ball-milled mesophase pitch was placed in a high-pressure reactor vessel, filled with nitrogen to 1.5 MPa, heated to 300 °C for 1 h and then the temperature was raised to 480 °C for 4 h. After that, the sample was taken out for carbonization. We placed the sample in the tubular furnace, with argon as the protective gas with ventilation rate 0.2 L/min, heated it to 600 °C for 1 h and then raised the temperature to 900 °C for 2 h. After this program was finished, the tubular furnace was cooled naturally to room temperature to obtain carbon foam material.Carbon foam was cut into 50 mg, 75 mg, 100 mg, 125 mg and 150 mg samples; after ultrasonic cleaning, these samples were immersed into graphene gel for 48 h and then put in a vacuum drying oven at 70 °C for 48 h to obtain graphene-modified carbon foam composites.Scanning electron microscopy  was used to analyze the morphology and microstructure of the composite. The crystal structure of the samples was characterized by X-ray diffractometer with Cu target . A Raman spectrometer  was used to characterize the microstructure and defects of samples.The universal testing machine  was used to test the mechanical properties of graphene-modified carbon foam composites. First, the composite materials were cut into small samples with the dimension 10 mm × 10 mm × 10 mm; these samples were compressed between two stainless platens with a loading rate of 0.5 mm/min, which is widely adopted in the compression strength testing of carbon foam ,33, and The bulk density of graphene-modified carbon foam composites was measured according to the Archimedes method. The porosity was calculated as follows:2 = 0.98228.In this paper, MB solution was taken as the target pollutant to test the adsorption performance of the graphene-modified carbon foam composites. First, the standard concentration curve of the MB solution needed to be calibrated. According to the measurement results of a double-beam ultraviolet–visible photometer, the maximum absorption wavelength of MB is 666 nm. MB solution with concentration 1–5 mg/L and concentration gradient 1 mg/L was prepared, and the corresponding absorbance was measured, respectively. The standard working curve of MB solution with MB concentration as the abscissa and absorbance as the ordinate was drawn, as shown in t (tq), the final adsorption capacity (eq) and the removal rate (R) of composite were calculated as follows:V is the volume of MB solution (L) and m is the mass of the adsorbent (mg).Then, we measured the absorbance of MB with graphene-modified carbon foam composites as adsorbent and calculated the concentration of MB according to the standard working curve of the MB solution; the change of dye concentration was obtained and then the adsorption capacity at time The SEM images of graphene-modified carbon foam composites are shown in Crystallographic analysis was carried out on the raw carbon foam and graphene-modified carbon foam composites, respectively, and the results are shown in 2 hybrid plane. The 2D peak also represents the degree of atomic confusion. The stacking degree of graphene can be determined by the height of the 2D peak. In addition, the strength ratio of the D peak and G peak, R = ID/IG, represents the defect degree and graphitization degree of the material. The larger the R value, the more defects of the material and the worse the structural order.The Raman spectrum of raw carbon foam and graphene-modified carbon foam composites is shown in −1, 1570 cm−1 and 2700 cm−1. The D and G peaks of the composite were significantly higher than those of raw carbon foam, while the 2D peak of composites showed a broad peak shape, indicating that the graphene prepared was multilayer. In addition, the R value of the raw carbon foam was 0.98, while the R value of the composite reached 1.15, indicating that the prepared graphene-modified carbon foam composite had more defects, because the graphene had not been fully reduced, and the carbon foam had not been graphitized. These large numbers of defects provided more adsorption active sites, which were conducive to improving the adsorption performance of the composites. It can be seen from It should be emphasized that the adsorption rate and adsorption capacity of raw carbon foam were 37.33% and 74.65 mg/g, respectively, so the addition of graphene gel effectively improved the adsorption performance of the composites. Compared with raw carbon foam, when the graphene-to-L-cysteine ratio was 0.5, the maximum adsorption rate and adsorption capacity of the modified composites reached 93.71% and 93.47 mg/g, increased by 151% and 25%, respectively. This is because, at the stage when the ratio was 0.5–0.6, the specific surface area of carbon foam was significantly increased by adding graphene gel, and there were many surface active sites of graphene gel which provided more adsorption sites for MB molecules, so the adsorption rate and adsorption capacity were significantly improved. When the ratio reached 0.6, the graphene gel content reached saturation. In the second stage, with the increase in the graphene content, the graphene folds covered each other due to the stacking of multiple layers of graphene. Moreover, too much graphene gel covered the through-hole of carbon foam, which was not conducive to the increase in the specific surface area of the composites, thus, gradually reducing the adsorption rate and adsorption capacity. The samples of graphene-modified carbon foam composites with masses of 50 mg, 75 mg, 100 mg, 125 mg and 150 mg were used for the adsorption test on the MB solution with concentration of 5 mg/L; the adsorption rate and adsorption capacity of the samples were calculated subsequently. The testing results are shown in We immersed 150 mg of composites in MB solution with different initial concentrations ; after the adsorption equilibrium state was achieved, the relationship between MB solution concentration and adsorption rate/adsorption capacity was calculated, as shown in It can be inferred that the higher the concentration of MB solution, the more MB molecules. Hence, more MB molecules can contact the sample surface and be captured. Finally, on the premise of the same sample mass, the higher the concentration of MB solution, the more MB molecules are adsorbed on the sample surface, so the adsorption capacity increases. On the other hand, although the number of adsorbed MB molecular increases, the MB solution concentration also increases in a larger amount, so the adsorption rate of the composite to MB solution is reduced.+ in the solution was ionized and attached to the surface of the composites, which made the sample have positive electricity. Because MB is a cationic dye, there was a competitive adsorption phenomenon between ionized H+ and MB molecules in the solution. Therefore, the adsorption of the MB molecules on the composites was reduced, and the stronger the acidity, the lower the adsorption of the MB molecules. On the contrary, when the solution was alkaline, a large number of OH− ions in the solution were ionized, which attached to the sample surface to make the composites have negative electricity. OH− ions on the sample surface adsorbed cationic dyes to the surface of the sample through electrostatic action. With the increase in pH value in the MB solution, more OH− ions were ionized from the solution; thus, more OH− ions attached to the surface of the composites. As a result, more MB molecules were adsorbed by the composites, which led to the improvement of the adsorption performance. Compared with raw carbon foam, when the pH value of the MB solution was 11, the maximum adsorption rate and adsorption capacity of the modified composites increased by 158.18% and 93.50%, respectively.We immersed 150 mg of composites in MB solution with concentration of 5 mg/L and pH values of 3, 5, 7, 9 and 11, respectively. The relationship between the pH value of the MB solution and the adsorption rate/adsorption capacity is shown in In this paper, graphene-gel-modified, pitch-based carbon foam composites were synthesized. The microstructure and morphology of the composites were studied by SEM, XRD and Raman spectroscopy; the compressive property and porosity were also tested. The adsorption test was carried out using MB solution to simulate a dye solution. The influence of the composite properties and MB solution on the adsorption performance was investigated. Through the microstructure characterization of the composites, it was found that the surface of the carbon foam was fully covered by graphene, and some graphene oxide was not completely reduced. Raman spectroscopy showed that the graphene gel on the surface of the composite had a multilayer graphene structure with many edge defects, which provided sufficient active adsorption sites and helped to increase the adsorption performance of the composites. With the increase in the mass ratio of graphene to L-cysteine, the compressive properties of the composites also increased. When the mass ratio of graphene to L-cysteine was 2.0, the compressive strength of the composites reached 13.5 MPa, increased by 53.41%. Results showed that the porosity of the composite after graphene modification was 58.14%, which was 24.15% higher than that of raw carbon foam. According to the analysis of the adsorption performance, when the mass of the adsorbent was 150 mg, the initial concentration of the MB solution was 5 mg/L, and the pH value of the MB solution was 11; the composites showed the best adsorption effect. In this case, the adsorption rate was 96.3%, increased by 158.18%, and the adsorption capacity was 144.45 mg/g, increased by 93.50%.


It is aructures . FurtherDan and Rick). The minimum electron dose for reducing the high-resolution limit determined by SPA was tenfold higher than that measured by MicroED. The authors also propose strategies for collecting high-resolution data using SPA and MicroED.Radiation damage is one factor that limits the resolution of three-dimensional structures of biological specimens when using cryo-EM. In their contribution to the collection, Shi and Huang thoroughly compare radiation damage assessments using single particle analysis (SPA) and micro-crystal electron diffraction (MicroED) (Hongcheng and Fei).Cryo-EM specimen preparation is the current bottleneck that impedes the broader use of cryo-EM, and many groups have been working hard to improve this. Common issues with the vitrification process include poor/non-uniform distribution of protein molecules (particles), preferred orientation, protein denaturation/degradation at the water-air interface, and high background noise from thick ice. One of the techniques developed to improve cryo-EM specimen preparation is the use of support films made of graphene and its derivatives. In their review, Fan and Sun discuss the advantages of graphene grids over conventional holey carbon film grids, the functionalization of graphene support films, how to make graphene grids, and the origins of pristine graphene contamination (Ilyes and Slavica), referred to as DeepHEMNMA, that speeds up the original method by combining it with a residual neural network (ResNet)-based deep-learning approach. The authors demonstrate the performance of DeepHEMNMA using synthetic and experimental data. Two-dimensional classification has played an important role in getting rid of junk particles from large datasets, and in sorting out the conformational heterogeneity of proteins/protein complexes in a dataset. However, the process can take a long time to complete if only central processing units (CPU) are used, especially for large datasets or large box sizes, which are common in today’s cryo-EM environment. Fabian et al. presented a graphics processing unit (GPU)-accelerated version of iterative stable alignment and clustering (ISAC) .Conformational heterogeneity of a biological molecule is a prerequisite for it to be able to perform its functions. In cryo-EM, specimen heterogeneity not only presents the challenge of obtaining high-resolution structure but also provides the opportunity to determine multiple structures of the same molecule/complex, with different conformations, from the same dataset, allowing investigation of the conformational changes associated with its biological functions. Hybrid electron microscopy normal mode analysis (HEMNMA) was first developed in 2014  to analyg (ISAC)  that enaPaula).Cryo-electron tomography (cryo-ET) has drawn much attention in recent years, and people believe it has great potential in the fields of cellular and structural biology. In this regard, Paula Navarro has provided an overview of current hardware and software developments that allow quantitative cryo-ET studies, and discussed the limitations of cryo-ET and how to overcome them to unleash its full power .Despite the wide applications of cryo-EM, which are due, especially, to its potential to revolutionize structural biology and new drug development, the high monetary and human resource costs involved with establishing and maintaining a high-end cryo-EM facility limit its accessibility. As a result, governments, universities, research institutes, and pharmaceutical companies around the globe have established high-end cryo-EM centers that provide access to researchers for free or at a reduced cost . How the


Contextual mobile advertising, with the advantages of high interactivity and immersive experience, is the mainstream trend of future Internet advertising. Current studies have explored the benefits of contextual mobile advertising while lacking the analysis of contextual mobile advertising factors on consumer purchase intentions. This study investigates the mechanisms by which the characteristics of contextual mobile advertising evoke consumers' purchase intentions through advertising attitudes to reveal how extroversion and neuroticism in personal traits moderate the relationship between characteristics of contextual mobile advertising and advertising attitudes. Based on a sample of 543 community residents with mobile shopping experience in China, this study uses structural equation modeling to validate the relationships between the variables and draws conclusions. The findings help advertisers to grasp the important characteristics of contextual mobile advertising, improve consumers' attitudes toward advertising, and enhance purchase intentions. Furthermore, it is possible to expand perceptions of the effectiveness of contextual mobile advertising among consumers with different personality traits. With the rapid development of the Chinese mobile Internet, the size of mobile Internet advertising continues to climb in the percentage of overall Internet advertising. As reported by iResearch in 2020, in China, mobile advertising accounted for 87.7% of all Internet advertisingIt is worth noting that if companies want to change consumers' advertising attitudes through the presentation of contextual mobile advertising, to arouse more purchase intention and promote the sales of their products or services, they should study what characteristics of contextual mobile advertising have such an effect. At present, scholars do not give a clear definition of contextual mobile advertising. Yuan and Tsao  first meIn addition, a potential factor that cannot be ignored in the process of the important characteristics of contextual mobile advertising influencing advertising attitudes is personality traits. The previous studies of personality traits can help us deeply understand the differences in consumers' attitudes. Different consumers have different advertising preferences, two people will not have the same emotional reactions and attitudes toward advertising; they often respond most positively when advertising matches their personality traits, developing positive advertising attitudes  were recruited from Chinese community residents with a mobile shopping experience. In this study, the answer to the questionnaire with missing data was not submitted successfully, so there were no missing data. In addition, we screened out the data of extroverts and neurotics from 1,473 respondents through the personality traits test, which was used in the final analysis of this study. The final valid sample (n = 543) consisted of 262 females (48.25%) and 281 males (51.75%). The sample had a mean age of 24.72 years (range 18–45). Education was assessed through four options, and participants were asked to check a box to make a choice: 11.42% selected “High school or below,” 9.39% selected “Associate degree,” 46.78% selected “Bachelor degree,” 32.41% selected “Graduate degree or above,” and no one left the question blank. In addition, among the final valid sample (n = 543), 295 samples were extroverts and 248 samples were neurotics after the personality traits test. Among them, 152 samples were high extroverts based on 1sd above the mean, and 116 samples were high neurotics based on 1sd above the mean  purchase intention of products shown in Facebook advertising  were significantly poorer than those of the four-factor model  suggesting that common method bias is not a serious concern in our data set.The existence of common method bias in the data set was tested by using the Harman's one-factor test. The items of all four factors  were combined into a single factor and compared with that of the four-factor model. The goodness of fit indices of the one-factor model , advertising attitudes, purchase intention, and personality traits (extroversion and neuroticism) were collected at one time, therefore, it was necessary to conduct Confirmatory Factor Analysis (CFA) to compare different models. The Cronbach's alpha and CFA of the scales were calculated by Mplus 7.0.2 = 436, df = 203, CFI = 0.93, GFI = 0.92, IFI = 0.94, RMSEA = 0.05, SRMR = 0.04) as compared to the alternative models  was estimated in this study. Another model (three-factor) was also estimated, in which contextual mobile advertising characteristics were combined on one-factor, advertising attitudes and purchase intention were combined on one-factor, extroversion and neuroticism were combined on another factor. The fit indices of these alternative models were weak compared to the six-factor model, providing support for the distinctiveness of the model used in this study. The CFA results revealed that the six-factor structure provided a better fit , thus supporting H1. Content accuracy also positively influenced advertising attitudes , supporting H2. Advertising attitudes were shown to have positive effects on purchase intention , supporting H3. In conclusion, this study identified contextual interaction and content accuracy as important characteristics that motivate consumers to be attracted by contextual mobile advertising. In addition, these two characteristics of contextual mobile advertising are stimulated by positive advertising attitudes, which also effectively increase purchase intention.The model fit indices revealed that the model had a good fit with the Comparative Fit Index (CFI) = 0.91, Incremental Fit Index (IFI) = 0.91, and Standard Root Mean Square Residual (SRMR) = 0.04, and Root Mean Square Error of Approximation (RMSEA) = 0.05. The results of the structural model are presented in To test moderation hypotheses, a two-way moderated regression was selected , and the direct effect of content accuracy was significant on advertising attitudes . Step 3 shows the result of adding the interaction term . As shown in p < 0.01; β = 0.203, p < 0.01). This analysis produced a significant main effect and a significant interaction effect ; when high extroversion (High EX) (above one standard deviation), the positive relationship between contextual interaction (CI) and advertising attitudes (AA) is significant , that is, high extroversion is more sensitive to the changes of contextual interaction. Thus, those high in extroversion will show more positive advertising attitudes toward contextual mobile advertisements with high contextual interaction. Hypothesis 4a is supported.To further reveal the interaction effect, a simple slope test was performed. As shown in ns.); when low extroversion (Low EX) (below one standard deviation), the positive relationship between content accuracy (CA) and advertising attitudes (AA) is significant , that is, low extroversion is more sensitive to the changes of content accuracy. Hypothesis 4b is not supported.As shown in p < 0.01), and the direct effect of content accuracy was significant on advertising attitudes . Step 3 shows the result of adding the interaction term . As shown in p < 0.01; β = 0.221, p < 0.01). This analysis produced a significant main effect and a significant interaction effect . When there is high neuroticism (High NE) (above one standard deviation), the positive relationship between contextual interaction (CI) and advertising attitudes (AA) is significant , that is, high neuroticism is more sensitive to the changes of contextual interaction. Thus, those high in neuroticism will show more positive advertising attitudes toward contextual mobile advertisements with high contextual interaction. Hypothesis 5a is supported.To further reveal the interaction effect, a simple slope test was performed. As shown in p < 0.001); when there is high neuroticism (High NE) (above one standard deviation), the positive relationship between content accuracy (CA) and advertising attitudes (AA) is also significant , that is, high neuroticism can promote the relationship of content accuracy and advertising attitudes. Low neuroticism has a weak moderating effect on the relationship between content accuracy and advertising attitudes. Thus, those high in neuroticism will show more positive advertising attitudes toward contextual mobile advertisements with high content accuracy. Hypothesis 5b is supported.As shown in The main purpose of this study was to investigate which characteristics of contextual mobile advertising evoke consumers' purchase intentions through advertising attitudes among community residents with the online shopping experience in China and to discuss how extroversion and neuroticism in personal traits moderate the relationship between significant characteristics of contextual mobile advertising and advertising attitudes. Through an extensive review of the prior literature and the status and issues in the development of contextual mobile advertising, this study concludes that contextual interaction and content accuracy can serve as stimuli that trigger positive consumer attitudes toward contextual mobile advertising and increase consumers' purchase intentions. Thus, contextual mobile advertising, featuring strong interactivity and high precision, is much easier to evoke consumer emotions and change consumer attitudes. This study further discussed the differences in perceptions and attitudes toward contextual mobile advertising characteristics between groups with extroversion traits and neuroticism traits. The findings showed that high extroversion and high neuroticism are more sensitive to the changes in contextual interaction, and low extroversion is more sensitive to the changes in content accuracy. High neuroticism can promote the relationship between content accuracy and advertising attitudes. Low neuroticism has a weak moderating effect on the relationship between content accuracy and advertising attitudes.From the theoretical perspective, the influence of contextual mobile advertising characteristics on the purchase intention in this study is mainly based on two theories: First, the scene theory. Scene theory combines “scene” and “media,” and believes that the approach of new media will generate new scenes with fresh behaviors. With the booming of mobile Internet, the scene theory has been given new connotations, such as mobile devices, social media, big data, sensors, and location-based systems. These five technologies are closely related to scenario communication, and in turn, promote the communication effect. Based on the scene theory, this paper explored the mechanisms affecting consumers' advertising attitudes from the perspectives of contextual interaction and content accuracy, and then examined the influence of advertising attitudes on the purchase intention. Second, according to the Planned Behavior Theory, attitude is one of the essential factors influencing consumer behavior. Attitude is often considered an indicator in the study of mobile advertising effectiveness. Contextual mobile advertising characteristics not only reduce consumers' aversion and increase positive advertising attitudes but also induce consumers' purchase intentions and purchase behaviors. This study found that contextual mobile advertising characteristics play an important role in the practical application of stimulating advertising attitudes, and how to maximize consumer satisfaction through contextual stimulation would become a hot issue for future research in the domain of contextual mobile advertising. Meanwhile, this study explores how to maximize the communication value of advertising by enhancing contextual interaction and content accuracy. This study not only extends the research on mobile advertising but also further expands the antecedent variables of advertising attitudes. In addition, this study examines the moderating effects of extroversion traits and neuroticism traits on contextual mobile advertising characteristics and advertising attitudes from personality trait theory. From the practical perspective, the application of contextual mobile advertising is conditional and may affect individuals with different personality traits differently.Overall, this study broadens the horizons of future research in exploring and studying the individual differences in contextual mobile advertising audiences. Contextual mobile advertising, rooted in location-based, big data, social media, and other technologies to achieve the accurate delivery of advertising, is changing the traditional bombing advertising patterns to reduce consumer advertising avoidance. Not only can contextual mobile advertising take consumers' current time, space, and psychological state into consideration entirely and cater to consumers' needs, but achieve higher advertising click rate, conversions, and higher ROI index of enterprises. Therefore, these findings can help advertisers improve the delivery efficiency of contextual mobile advertising and provide more personalized advertising recommendations to consumers  Cross-border E-commerce College (No. 2021KXYJ06), Philosophy and Social Science Foundation of Zhejiang Province (21NDJC083YB), National Natural Science Foundation of China (71702164), Natural Science Foundation of Zhejiang Province (LY20G010001), and the Contemporary Business & Trade Research Center of Zhejiang Gongshang University .The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. 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Carbon-based nanomaterials are currently attracting a lot of interest in many fields, ranging from medicine and biotechnology to electronics, energy storage, and sensing applications ,2. They One characteristic of all carbon nanomaterials is the possibility of functionalizing them through non-covalent and covalent methods ,7, whichWith an enlarged global focus on tackling the challenges of environmental pollution, the interest in novel energy devices as an alternative to petroleum-based ones has also increased. In this regard, supercapacitors can be designed for use in environmentally friendly vehicles and new renewable energy; however, the limitation of a low energy density remains a challenge . To furtHierarchical porous activated carbon (HPAC) is another interesting active material for supercapacitors due to its huge specific surface are. Preparing electrodes with high-mass loading is interesting in providing high total capacitances and gravimetric or volumetric energy densities . TherefoIn another study, a novel carbonaceous material was prepared from cellulose carbonized via two-steps—hydrothermal and thermal carbonization, in order—without any chemicals , giving 2+ detection, leading to a linear concentration range of 0–250 nM, with a limit of detection of 3.93 nM, and it was successfully applied to real samples of pond water, leading to recoveries in the range from 99.6% to 101.1%.GO is well known for its outstanding fluorescence quenching capability. Sun et al.  preparedBased on the fluorescence quenching ability of nitrogen- and phosphorous-doped carbon dots, a simple and selective sensor for glutathione detection was also developed . The redNitrogen-doped amino acid-functionalized GQDs show enhanced photoluminescence and photostability and lead to the generation of reactive oxygen species through two-photon photodynamic therapy (PDT) . This amNitrogen oxides (NOx) are amongst the foremost atmospheric pollutants; hence, it is imperative to screen and detect their presence in the atmosphere. For such a purpose, low-dimensional carbon structures have been broadly used as NOx sensors. In particular, CNTs have been applied for sensing toxic gases due to their high specific surface area and excellent mechanical properties. Even though pristine CNTs have shown promising performance for NOx detection, several strategies have been developed such as surface functionalization and defect engineering to expand the NOx-sensing ability of pristine CNT-based sensors. In this regard, the surface modification approaches used in the recent decade to modify the sensitivity and the selectivity of CNTs to NOx have recently been reviewed . 2, CH4, and O3. Canales et al. [30 for the adsorption of these pollutants. They performed computational simulations to investigate their adsorption on graphene-semifullerene (C30) surfaces, considering two C30 geometries—hexagonal and pentagonal bases—and found that it is possible to dope all surfaces with Li, Ti, and Pt, which can be used as effective catalysts.Other atmospheric contaminants that threaten the environment and life include CO, COs et al.  have expOn the other hand, given that the control over radioactive species is currently critical, the development of functional materials for the decontamination of radioactive substances has also become imperative. In this regard, Bae and coworkers  have recStudying acoustic plasmons (APs) in single-layer, double-layer, and multilayer graphene or in metal/dielectric/graphene superstructures is another active field of research. Although the mechanism of the formation of these plasmons in electrostatically biased graphene or at noble metal surfaces is well known, the mechanism of their formation in alkali-doped graphene is not well understood yet. In this regard, Marušic and coworkers have investigated the interplay of the p and s intraband transitions with plasmon resonance . Their wOn the other hand, the interaction between photons and polarization modes can result in the formation of hybrid photon polarization modes, called polaritons. The same authors  have shoAs known, graphene is a versatile compound with many outstanding properties, providing a combination of a huge surface area, a high strength, and thermal and electrical properties, with a wide array of functionalization possibilities. However, the available literature on graphene-based coatings in dentistry and medical implant technology is scarce. Srimaneepong and coworkers  have rec


Sarcoidosis is a complex granulomatous disease of unknown etiology. Due to the heterogeneity of the disease, the diagnosis remains challenging in many cases, often at the physician’s discretion, requiring a thorough and complex investigation. Many other granulomatous diseases have the potential to mimic sarcoidosis, whether infectious, occupational, or autoimmune diseases and starting an unnecessary corticosteroid treatment can worsen the patient’s prognosis, leading to side effects that can be harder to treat than the actual disease. Sarcoidosis is a complex multisystemic granulomatous disease, with unknown etiology and variable clinical manifestations, which frequently manifests with thoracic , ocular, and cutaneous involvement. The diagnosis of sarcoidosis requires the identification of noncaseated epithelioid granulomas in one or more organs along with the exclusion of other pathologies that could cause granulomatous lesions. However, because of the similarities with other pathologies, an incomplete picture of the disease can lead to errors in the diagnosis, which is why in this paper we propose a detailed review of the most common pathologies and their role in a possible misdiagnosis regarding sarcoidosis ,2. The onset age of sarcoidosis shows two peaks of incidence, with the first in the 3rd decade of life and another one in the 5th decade. In terms of geographic distribution, studies have shown higher incidences in the Scandinavian countries, with an incidence in Sweden of 11.5 per 100,000, followed closely by the United States at around 8–11 per 100,000 and Canada at 6.8 per 100,000. Very low incidence was reported in countries in East Asia, such as South Korea with 0.5–1.3 per 100,000. Racial variation is also encountered. For example, the non-Hispanic American black population tends to have a higher incidence; among them, black women have the highest rates.Regarding the variations between the sexes, the results are controversial, since some studies reported a higher incidence in women and some studies found no differences at all ,4. Often, in clinical practice, the heterogeneity of the disease can lead to an erroneous diagnosis of sarcoidosis, often with a significant impact on the patient’s life. In the following, we propose to highlight a series of investigations that can help establish a diagnosis as well as the diagnostic errors that may occur.In regards to the symptoms, sarcoidosis can present itself in multiple forms and in various combinations, from asymptomatic or clinically insidious forms to acute forms with multiple organ involvement . The mosConsidering the extremely varied clinical appearance that can lead to confusion and misdiagnosis, the patient suspected of sarcoidosis requires a rigorous evaluation from an anamnestic, clinical, biological, radiological, and histological point of view, often requiring interdisciplinary collaboration between a pulmonologist, cardiologist, dermatologist, ophthalmologist, and neurologist. It is wrong to base the diagnosis on the mere association of some clinical symptoms. A thorough anamnesis is important, as it can identify exposures to respiratory toxins in the work environment  or exposures to various substances or antigens that could cause interstitial lung disease . HighligLaboratory tests are an integral part of the diagnostic process of suspected sarcoidosis. Although there are no standardized or definitive biological markers, a series of tests can guide the diagnosis .ACE levels in patients suspected of sarcoidosis can also be influenced by genetic variations and ACE inhibitor therapy. One study by d’Alessandro et al., who analyzed serum samples from patients diagnosed with sarcoidosis and taking ACE inhibitor therapy, found that serum ACE levels were lower in these patients compared to those not taking ACEIs .Chest radiography has long been, and still is, a key investigation in the diagnosis of sarcoidosis. The Scadding classification made in 1961 divided sarcoidosis into five stages  5]. Thi. Thi5]. On the other hand, the use of HRCT (high-resolution computer tomography) examination can detect abnormalities unidentifiable on a simple chest X-ray, including micronodules or pleural involvement, and can more accurately examine lung parenchyma, lung hilum, and mediastinal lymph node stations . ConsideOne interesting imaging technique that can be useful in the diagnosis of sarcoidosis is 18 fluorodeoxyglucose (FDG) PET/CT. In thoracic sarcoidosis, mediastinal and hilar lymphadenopathy is found to be hypermetabolic on FDG PET/CT, as well as other parenchymal lesions such as nodules or masses. Although it is not recommended as a part of the initial workup, FDG PET/CT can provide essential information regarding the extent of the disease, cardiac and bone involvement, and the response to treatment, and can also guide a convenient biopsy site .Fiberbronchoscopic examination and bronchoalveolar lavage represent an integral part of the diagnosis of sarcoidosis and should be performed in every eligible patient who has no absolute contraindications.Although in most cases the macroscopic endobronchial appearance is normal, the presence of granulations of the bronchial mucosa, secondary to granulomatous inflammation, erythema of the mucosa, and a cobblestone appearance, have been cited ,23.Bronchoalveolar lavage cytology is sometimes used as a biological marker for sarcoidosis, but its exact role is not yet clarified. Although lymphocytosis and normal neutrophil and eosinophil levels are frequent in the lavage of sarcoidosis patients, the diagnostic value of such findings is under debate; a similar situation is reported for CD4/D8 ratio . BronchoOn the other hand, lymphocytosis is not specific to sarcoidosis, being found in many other diseases such as tuberculosis or pulmonary mycosis, especially in the context of a CD4/CD8 ratio below 3.5 .The advantage of the fiberbronchoscopic examination is the performance of biopsies using the different techniques illustrated, alone or combined . The diaThe typical histological pattern is epithelioid granuloma with a compact agglomeration of epithelioid cells and multinucleated histiocytes, with rare lymphocytes, non-necrotizing. In rare cases, granulomas with caseification can also be found. However, highlighting the granuloma without caseification does not establish the diagnosis of sarcoidosis, as it is necessary to integrate clinical–radiological and serological investigations to form a complete picture, in order to attain a diagnosis of increased accuracy ,9,25.Even if the disease in question is pulmonary sarcoidosis, radioclinical manifestations are not sufficient for an accurate diagnosis, and obtaining biopsies from mediastinal/hilar lymphadenopathies or from the lesions expressed in lung parenchyma should represent a priority for the clinician to avoid a false diagnosis of sarcoidosis . If obtaWhenever possible, other organs should be investigated where a less invasive biopsy sample could be obtained, such as a skin lesion or a conjunctival nodule (with the exception of erythema nodosum lesions) .The only form of sarcoidosis considered specific enough to not require a biopsy is Lofgren’s syndrome with the association of bilateral hilar adenopathy, erythema nodosum, fever and joint involvement, lupus pernio and Heerfordt syndrome ,26.The certainty diagnosis of sarcoidosis remains, most of the time, a diagnosis of exclusion, never certain, and often at the discretion of the attending physician. The nonspecific symptomatology, the granulomatous-type inflammation, that is also found in other pathological conditions, the absence of specific and sensitive markers and the lack of a perfect investigation, often make the diagnosis difficult and prone to errors, both through overdiagnosis and also by classifying it as another disease . The resAlthough the differential diagnosis of pulmonary sarcoidosis is exhaustive and includes both rare and frequent diseases, in the following we will discuss the most common pathologies that can mimic pulmonary sarcoidosis: respiratory tuberculosis, malignancy, pneumoconiosis, sarcoid-like reactions induced by drugs (DISR), hypersensitivity pneumonitis vasculitis and connective tissue diseases, and common variable immunodeficiency syndrome (CVID).Infection with Mycobacterium tuberculosis is the most common pulmonary infection of the granulomatous type. Not only in countries with a high incidence, but pulmonary tuberculosis should also represent the main differential diagnosis with sarcoidosis, as its wrong diagnosis can have nefarious consequences for patients and their peers.From a clinical point of view, there is an undeniable similarity between sarcoidosis and pulmonary tuberculosis, which can make them, in the first phase, impossible to differentiate from one another. The insidious onset and nonspecific symptoms such as cough, fever, night sweats, weight loss, and fatigue are present in a large proportion of patients with both pathologies ,26,27.Although the radiological picture in tuberculosis is quite suggestive, with nodules, infiltrates, and a tendency to cavitation predominantly in the apical regions of the lung, there are situations in which the radiological presentation can be prone to confusion, especially in an immunosuppressed patient of whose radiological aspects tend to be nonspecific. On the other hand, the disseminated form of tuberculosis (miliary tuberculosis) can lead to a misdiagnosis of sarcoidosis, especially in the conditions of repeatedly negative bacteriological examination . The preTypical for tuberculosis is the histological evidence of granuloma with caseification necrosis. On the other hand, cases of tuberculosis with the presence of granuloma without caseification are cited in the literature and can occur in up to 20% of cases .The clinical presentation of tuberculosis can be varied and atypical, as suggested by a case study by Chokoeva et al. that raised issues regarding the differential diagnosis in the case of a 35-year-old patient with skin lesions (erythematous plaques with asymmetric distribution on the face), bilateral cervical adenopathy, bilateral hilar adenopathy, and micronodules with bilateral distribution predominantly in the middle-lower lung areas, in which the histopathological exam highlighted sarcoid-like granulomas, but with a positive interferon-gamma release assays (IGRAs) test. A Ziehl–Neelsen staining was performed and found positive, which concluded the diagnosis as tuberculosis . Extrapulmonary involvement should not exclude the diagnosis of tuberculosis, even in the context of the evidence of granulomas without caseification necrosis. Usama et al. reported a case concerning a 37-year-old patient with a history of chronic alcohol consumption, hospitalized for ascites of unknown etiology, in which the histopathological examination of a liver biopsy revealed granulomas without caseification necrosis, establishing the diagnosis of sarcoidosis. The evolution of the patient was unfavorable, which is why the investigations were continued and the CT examination revealed micronodular bilateral lung lesions, and the Ziehl–Neelsen staining from the sputum sample was found to be positive .What the aforementioned suggests is the fact that the histopathological evidence may sometimes not be obvious for tuberculosis, but a complete set of investigations, including specific staining for the samples obtained , should be included in the management of patients in which the differential diagnosis between tuberculosis and sarcoidosis is not clear.Malignant conditions remain a diagnosis that can induce diagnostic errors with sarcoidosis, whether it is malignant solid tumors or lymphomas. Hodgkin’s and non-Hodgkin’s lymphomas can most frequently be confused with sarcoidosis, causing granulomatous reactions . Hilar lMalignancy and sarcoidosis can have many overlapping features, making an accurate diagnosis difficult to establish. However, the association between sarcoidosis and cancer should be taken into account, as illustrated by Serra et al., who reported the case of a 65-year-old woman with a wrist mass, whose histopathological exam revealed epithelioid noncaseating granulomas, establishing the diagnosis of soft tissue sarcoidosis. The patient underwent further examination, which revealed intrathoracic lymphadenopathies and interstitial lung lesions, lesions that were biopsied, and confirmed lung sarcoidosis. Blood tests showed monoclonal IgG kappa gammapathy, and a bone marrow biopsy was performed, showing hypercellularity with 60% plasma cells and plasmocyte infiltration, establishing the diagnosis of multiple myeloma and sarcoidosis. In addition, the authors found another 33 case reports of both sarcoidosis and multiple myeloma .Sarcoid-like reactions (SLRs) can be associated with various malignancies. The problem that such reactions pose is that the PET-CT examination cannot differentiate between sarcoid-like reactions and malignancy, because positive results are found in both situations. Unfortunately, no specific markers and no specific imagistic pattern were found for either of the two entities to be able to distinguish between them. Most of the time, invasive diagnostic methods are required, when obtaining histological material through fiberbronchoscopic methods is not possible ,32.Pneumoconiosis represents an occupational disease that occurs as a result of long and repeated exposure to various particles that induce a granulomatous pulmonary reaction.Silicosis occurs as a result of prolonged exposure and repeated inhalation of silica dust, which causes an immune reaction in the lung parenchyma. The symptomatology is nonspecific and the radiological image can highlight nodular changes with perilymphatic distribution, areas of fibrosis, lymphadenopathies with or without areas of calcification, eggshell-like calcifications, and changes that may have a predilection for the upper lung regions. All these aspects can also be found in sarcoidosis, which makes the patient’s history a key element in identifying a professional exposure to silica dust .Another type of pneumoconiosis that can lead to diagnostic confusion with sarcoidosis is berylliosis, an occupational disease that occurs secondary to prolonged exposure to beryllium and that can be difficult to differentiate radiologically, clinically, and histologically from sarcoidosis. There are many industries in which exposure to beryllium can occur, among the most common being the automobile industry, the biomedical industry, and the telecommunications industry .Berylliosis can be misdiagnosed as sarcoidosis in many cases, either because of an incomplete history or simply because the patient or the clinician is unaware of the chronic exposure to beryllium. The patient’s professional history takes a primary role, and in situations where the clinician is not sure of the exposure, a thorough investigation can be carried out in order to obtain correct exposure information .A study by Fireman et al. evaluated 47 patients reviewing their professional history, who were initially diagnosed with sarcoidosis. 14 of them had exposure to beryllium, and 3 patients out of the 14, in addition to the exposure history, also had a positive BeLTT test, being incorrectly diagnosed with sarcoidosis .A case report that emphasized the importance of professional history is the one reported by Cheva et al., which presented the case of a 71-year-old patient with mediastinal adenopathy and bilateral pleural effusion, in which the histopathological examination of the biopsy sample obtained from the paratracheal adenopathy revealed the presence of epithelioid granulomas without caseification necrosis, with histiocytes and Langhans multinucleated giant cells, suggesting an inflammatory condition. During a detailed anamnesis, exposure to beryllium was identified, as he was a worker in the fertilizer industry and the established diagnosis was that of berylliosis .Drug-induced sarcoid-like reactions—DISRs—refer to the development of a systemic granulomatous reaction, in direct relation to the administration of certain drugs. From a clinical, paraclinical, radiological, and histological point of view, it is similar to sarcoidosis, being almost impossible to differentiate in clinical practice. Bilateral hilar adenopathy, the presence of skin lesions, uveitis, and laboratory tests such as hypercalcemia and increased ACE in the serum represent elements that can be found in the picture of both conditions ,35. FromThe most frequently involved drugs are represented by immune checkpoint inhibitors, TNF-alpha antagonists, interferon, and antiretroviral therapy. In these situations, the patient’s history is very important, since these reactions can appear from 4 to 24 months after the start of the treatment, so each patient must be asked about the associated comorbidities and the treatment they are following. Stopping the treatment leads, in most cases, to the resolution of the syndrome. If DISR does not remit after stopping the offending drug, it can be treated similarly to sarcoidosis [Hypersensitivity pneumonitis represents a group of pathologies that appear as a result of the inhalation of small organic particles and that induces a type 3 allergic reaction, with the formation of antigen–antibody complexes, and a type 4 reaction with a granulomatous reaction. The etiology of hypersensitivity pneumonitis is varied because multiple types of particles can determine the development of hypersensitivity pneumonitis: Farmer’s lung disease—exposure to moldy hay or wheat; Detergent lung disease—exposure to enzymes from the detergent industry; and Bird Fancier’s Lung are only a few suggestive examples .From an imaging point of view, hypersensitivity pneumonitis and sarcoidosis can be similar by the distribution of nodular lesions or fibrotic changes predominantly in the upper lung regions. The nodules in sarcoidosis tend to be distributed perilymphatically, while in HP, the centrilobular distribution and ground-glass density represent the predominant imagistic features. The lack of lymphadenopathies should point the diagnosis toward hypersensitivity pneumonitis . The hisBronchoalveolar lavage can reveal lymphocytosis in both pathologies, but a study by Raghu et al. highlighted a higher lymphocytosis among HP patients. The CD4/CD8 ratio can represent a useful marker in the differential diagnosis, although sometimes the lavage results are unremarkable in both diseases .The patient’s history of exposure to organic particles, and the evidence of specific serum immunoglobulins, in the context of a suggestive radioclinical picture, advocate for the diagnosis of hypersensitivity pneumonitis . HoweverAutoimmune diseases should always be taken into consideration in the differential diagnosis of sarcoidosis. Patients who present with systemic, nonspecific symptoms and usually display a CT pattern of interstitial lung disease should be screened for systemic sclerosis, dermatomyositis, antisynthetase syndrome, and rheumatoid arthritis. The study of specific antibodies should not be skipped as it can add valuable information .In regard to connective tissue diseases, the patient’s clinic may present elements such as nonspecific symptomatology  and extrapulmonary involvement, including skin and eye lesions. The presence of granulomatous lesions in the histological examination can complicate the diagnosis among these patients .Vasculitis belongs to a group of autoimmune diseases characterized by the presence of granulomatous inflammation. They can resemble sarcoidosis from a clinical point of view, leading to diagnostic errors. When patients exhibit nonspecific symptoms, pulmonary involvement in association with renal dysfunction, vasculitis should be considered and the patient should undergo further investigations, as vasculitis can have a poor prognosis if untreated. From a histological point of view, there are differences that can orient the diagnosis toward one of these pathologies. The study of p-ANCA and c-ANCA antibodies represents an important step in the evaluation of the patient when there are diagnostic difficulties ,37.A case report by Thaniyavarn T. showcased the case of a 47-year-old man who was diagnosed with pulmonary sarcoidosis and was under treatment with infliximab. The initial diagnosis was established based on symptoms, with the negative serology for autoimmune diseases, suggestive lung imaging, and a Gallium scan showing uptake in both lungs, despite a biopsy and bronchoalveolar lavage not compatible with sarcoidosis. However, a decision was made to reevaluate the patient and repeat the serological tests, which showed CPK elevation and positive anti-PL-12, changing the diagnosis to antisynthetase syndrome .Common variable immunodeficiency syndrome is a heterogeneous disease that represents the most frequent form of primary immunodeficiency. Its key elements are an increased susceptibility to recurrent infections, as well as the presence of hypogammaglobulinemia .In some cases, CVID can be associated with granulomatous lymphocytic interstitial lung disease, with similar aspects to those encountered in sarcoidosis. Often, the symptoms are nonspecific, which can lead to errors in the diagnosis. However, the presence of splenomegaly and hypogammaglobulinemia, in addition to interstitial lung disease and a history of recurrent infections, should orientate the clinician toward common variable immunodeficiency syndrome, as misdiagnosis and treatment of CVID with corticosteroids can have a negative impact on these patients .A study by Jamal et al. described the case of a 53-year-old patient admitted for supraclavicular adenopathy, weight loss, and asthenia. The laboratory tests showed isolated lymphopenia, slight hypercalcemia, normal serum protein electrophoresis, and elevated ACE and lysozyme. Imaging investigations revealed supraclavicular lymphadenopathy, mediastinal and hilar lymphadenopathy, pulmonary infiltrates, bibasal reticulation, ground-glass opacities, and bronchiectasis. BAL showed a CD4/CD8 ratio of 5.75 and the bronchial biopsies revealed noncaseating epithelioid and giant cellular inflammation. The diagnosis established was systemic sarcoidosis and the patient was placed under corticosteroids with an initial favorable clinical course. The treatment was stopped after a year. The serum protein electrophoresis was performed, and revealed persistent hypogammaglobulinemia with lymphocyte immunophenotyping, confirming the diagnosis of CVID .Not all patients with sarcoidosis require systemic treatment because sarcoidosis can evolve in two different ways: a time-limited one  and a chronic one . Treatment is usually reserved for life-threatening organ involvement  or functional threat  .Sarcoidosis treatment is not an easy task, this disease evolution can vary very much from asymptomatic forms with only radiographic abnormalities found on routine check-ups to more fulminant evolution that can result in pulmonary disability and death. Therefore, some patients are overtreated and others are undertreated. Before the decision to apply treatment, it is necessary to establish the risk versus the benefit of the treatment, so physicians must consider the minimization of the risk of disability and the risk of death due to the loss of lung function or quality of life (QoL) impairment and the risk of the occurrence of adverse effects of glucocorticoids, such as comorbidities or QoL loss . The decBased on ERS clinical practice guidelines published in 2021, treatment with glucocorticosteroids should be implemented for patients that did not receive any treatment and have major involvement from pulmonary sarcoidosis in order to improve and/or preserve FVC and QoL . The recChronic pulmonary sarcoidosis is defined as an active disease for at least two years. Because of the known side effects of GC, the treatment of chronic pulmonary sarcoidosis should include second or third-line medications. The decision to use these lines of therapies should not be based on the duration of GC therapy, but rather on the significant risk of glucocorticoid toxicity or a clinical failure of glucocorticoid therapy. Second-line agents for pulmonary sarcoidosis include methotrexate (MTX), azathioprine, leflunomide, and mycophenolate. Third-line agents for pulmonary sarcoidosis include infliximab and adalimumab .Key consensus points of the Delphi consensus recommendations for a treatment algorithm in pulmonary sarcoidosis stated that glucocorticoids should be used as initial therapy for most patients and that immunomodulators, usual methotrexate, should be considered in severe or extrapulmonary diseases that need a long period of treatment, or that they should be considered in patients with a high risk of steroid toxicity as a steroid-sparing intervention. Regarding biological therapies, the consensus recommendations state that this type of therapy can be added if nonbiologic therapies are insufficiently effective or are not tolerated with initial biologic therapy, usually with a tumor necrosis factor-α inhibitor, typically infliximab .Treatment of extrapulmonary sarcoidosis should rely on three goals: improvement of organ dysfunction risks, mortality reduction, and quality of life improvement. The number of studies conducted in this field is limited. Before applying various treatments, some important points need to be considered: treatment should target the granulomatous process (anti-inflammatory drugs), and organ-directed treatments and supportive treatments should also be used. The treatment of organ dysfunctions can improve the outcome of sarcoidosis and include nonpharmacological therapies  or pharmacological therapies  .Experts in this field seem to agree that the best management of this type of patient should involve disease monitoring, and active treatment should depend on the tolerability of symptoms and risk of serious organ dysfunction. When prescribing the treatment, special attention should be given to patient-specific factors: In patients that are overweight and/or suffer from diabetes, GC should be avoided. Chronic kidney disease is a contraindication for treatment with methotrexate. Thiopurine S-methyltransferase (TPMT) deficiency is a contraindication for the use of azathioprine .The intensity of the inflammation and the affected organ are two factors involved in the type of clinical manifestations of sarcoidosis. Because there are no curative treatments, only suppressive medications can be used, and this type of treatment can cause side effects. Guidelines regarding the treatment of sarcoidosis still recommend the use of systemic corticosteroids as first-line therapy, with a slow reduction in dosage to long-term low-dose administration. This type of dosing is used because of the toxicity of long-term use of systemic steroids and the belief that by using small doses, the impact will be less serious, but data published in the literature seem to show that this type of strategy is not sufficient because side effects are still reported: a 30% increase in hypertension, 20–30% prevalence of fracture or osteoporosis, and an increase of up to 4 times in hyperglycemia and type 2 diabetes. In a retrospective, matched cohort study conducted in 2022, Einarsdottir et al. investigate all-cause and disease-specific mortality in a large group of Swedish oral glucocorticoids (GC) users. The Swedish Prescribed Drug Registry and the Swedish Cause-of-Death Registry were used to obtain information about dispensed prescriptions and the cause of death. The study included patients that received treatment with prednisolone ≥5 mg/day  for ≥21 days between 2007–2014. Patients receiving treatment with prednisolone had significantly higher all-cause mortality compared to controls. The highest adjusted hazard ratio was observed in high-dose users for deaths from sepsis–6.71 (5.12 to 8.81) and pulmonary embolism—7.83 (5.71 to 10.74) .Drent et al. conducted a study with the aim of assessing the prevalence of self-reported gastrointestinal side effects of these drugs. A total of 70% of the participants received one or more drugs, and the most prevalent and important side effect was weight gain caused by increased appetite among prednisone users . In 2021Data in the literature show that treatment with GCs is associated with a decrease in bone mineral density and an increased fracture risk, depending on the daily dose. The fracture risk occurs rapidly and decreases quickly to baseline after treatment discontinuance ,52,53. ACardiovascular risks of corticosteroids need to also be considered in the potential cardiovascular expression of sarcoidosis, and further research is needed to document the optimal dose and duration, or even to explore the benefits of corticosteroids administered via a safer inhalator route, when beneficial .A cohort study that investigated the risk of developing Type 2 diabetes (T2D) in patients suffering from sarcoidosis and the implication of treatment with corticosteroids in increasing the risk was published by Entrop et al. The results show that the risk of T2D was higher for patients suffering from sarcoidosis and receiving corticosteroid treatment in the first 2 years after diagnosis (The HR for T2D was 1.4 (95% CI 1.2–1.8) associated with untreated sarcoidosis and 2.3 (95% CI 2.0–3.0) associated with corticosteroid-treated sarcoidosis) .A group of international physician experts from eleven subspecialties  constructed an instrument that can measure glucocorticoid (GC) toxicity. The aim of the Glucocorticoid Toxicity Index (GTI) is to determine and measure the modifications that can occur in GC toxicity compared to points in time. Some of the domains investigated are body mass index, low-density lipoprotein concentrations, blood pressure, hemoglobin A1c, medication changes, occurrences of infections, assessments of muscle strength, skin toxicity, and the neuropsychiatric effects of glucocorticoids. GTI has been authorized by more than 45 studies, including 12 phase-3 clinical trials. At the present time, GTI can be used in clinical practice and clinical trials with the main aim of assessing the benefits of new medications that become available in treating this type of disease .When a misdiagnosis occurs and treatment with corticosteroids starts, the side effects depend on the misdiagnosed disease. For example, the use of corticosteroids in treating pulmonary TB has been argued over time, and experts in the field have different opinions regarding the outcomes. Studies conducted in this field show that long-term use of corticosteroids can make the patient susceptible to mycobacterial infection and to the development of TB, as well as reactivate latent bacilli within macrophages ,60. The Even though corticosteroids are used in many cancer treatment regimens, side effects appear and complicate their use. Neuropsychiatric toxicity is revealed by symptoms such as insomnia, cognitive impairment and mood symptoms, and severe mental disorders, including mania, psychosis, and severe depression . HyperglAlternatives to corticoids exist. Besides classic immunomodulators (such as methotrexate or mycophenolate), there are data suggesting a role for some of the available TNF inhibitors such as infliximab or adalimumab; furthermore, there is some hope regarding the use of anti-B agents such as rituximab. A more thorough understanding of inflammatory pathways is necessary in order to make use of contradictory reports regarding a plethora of other agents .A complete picture of the disease is required to establish an accurate diagnosis. The clinician should always conduct a thorough investigation of the patient, checking all the points, from simple anamnesis to complex investigations, in order to avoid a misdiagnosis. As demonstrated above, quite a few diseases can be misinterpreted as sarcoidosis, which can lead to inappropriate treatment, poor prognosis, and low quality of life.Despite a long history, sarcoidosis remains a challenge for everyday clinical practice. Initial diagnosis, decision to treat or to stop treating, choosing an immunomodulatory agent, or managing an unresponsive case is still difficult, despite existing management protocols. Corticosteroids are still considered first-line agents despite increasing data on their detrimental side effects. Patient education, comorbidity assessment, and side effect monitoring are paramount to avoid such unfavorable outcomes.


Here we overcome these challenges with a chalcogenide glass-on-CaF2 PIC architecture incorporating split-gate photothermoelectric graphene photodetectors. Our design extends operation to λ = 5.2 μm with a Johnson noise-limited noise-equivalent power of 1.1 nW/Hz1/2, no fall-off in photoresponse up to f = 1 MHz, and a predicted 3-dB bandwidth of f3dB > 1 GHz. This mid-IR PIC platform readily extends to longer wavelengths and opens the door to applications from distributed gas sensing and portable dual comb spectroscopy to weather-resilient free space optical communications.The development of compact and fieldable mid-infrared (mid-IR) spectroscopy devices represents a critical challenge for distributed sensing with applications from gas leak detection to environmental monitoring. Recent work has focused on mid-IR photonic integrated circuit (PIC) sensing platforms and waveguide-integrated mid-IR light sources and detectors based on semiconductors such as PbTe, black phosphorus and tellurene. However, material bandgaps and reliance on SiO μm. Here, the authors report the realization of photothermoelectric graphene photodetectors incorporated in a chalcogenide glass-on-CaF2 PIC operating at 5.2 μm, showing promising results for gas sensing applications.Mid-infrared photonic integrated circuits (PICs) are important for sensing and optical communications, but their operational wavelengths are usually limited below 4  To facilitate sensor deployment for greenhouse gas leak detection and other chemical sensor application areas, there exists a strong need to transition from co-packaged discrete components to compact and chip-integrated sensors.Mid-IR absorption spectroscopy is a critical tool for chemical sensing and analysis, especially for inert gases that evade detection by chemical reaction-based sensors. Many such gases derive their inertness from halogenated chemistries and thus exhibit global warming potential due to carbon-halogen stretching modes resonant in the thermal IR3 and volatile organic compound4 sensing, but required coupling to off-chip sources and detectors. However, integrating the detector on-chip is more compact and can improve sensitivity by reducing the volume of active material able to generate thermal noise. Su et al. achieved integration of a PbTe photoconductor and demonstrated methane sensing at a wavelength of λ = 3.31 μm5, but their platform is limited to λ ≲ 4 μm due to absorption in the SiO2 substrate6 and by PbTe’s absorption cutoff7. Waveguide-integrated detectors based on narrow-gap 2D materials black phosphorus8 and tellurene9 have also been demonstrated, but they too are bandgap-limited to λ ≲ 4 μm.To address this challenge, mid-IR photonic integrated circuit (PIC) platforms have been investigated to reduce optical gas sensors to the size of a chip. Recent work has demonstrated integrated optical methane10, the material’s advantages are magnified further at longer wavelengths due to the thermal nature of the photothermoelectric (PTE) response mechanism12 and due to the impact of optical plasmon scattering at short wavelengths13. Integrated photodetection with graphene has been demonstrated at wavelengths up to 3.8 μm6 and with chalcogenide glass waveguides14, but on SiO2 platforms. To access longer wavelength operation and achieve good sensitivity at zero-bias, we introduce a Ge28Sb12Se60 (GSSe)-on-CaF2 waveguide platform supporting gated PTE-based graphene photodetectors. These key changes allow us to extend operation to a wavelength of λ = 5.2 μm while achieving a Johnson noise-limited noise-equivalent power (NEP) of 1.1 nW/Hz1/2. By comparing the gate voltage maps of our device’s resistance, transmittance, and responsivity with a photothermoelectric model, we extract material quality parameters of the graphene channel, revealing a path to further reduce the device’s NEP by shrinking the optical mode size in tandem with the graphene channel.Here we exceed the wavelength limit of previous demonstrations using graphene-based detectors on an extended-transparency waveguide platform. While graphene integrated detectors have shown promise at telecom wavelengths2 as the gate dielectric and as an airtight capping layer. The device is fabricated on a CaF2 substrate, transparent up to λ = 8 μm. Figure λ = 5.2 μm.Figure λ = 5.2 μm QCL source into our chip’s input facet. Light exiting the chip is focused onto an InAsSb photodetector and amplified for transmission measurement. Supplementary Fig. f noise15. For the following low-frequency measurements we use a lock-in amplifier to measure the photovoltage directly with no preamplification.We use lock-in measurement to characterize our detectors, focusing light from a λ = 5.2 μm QCL source at 3.78 kHz with a guided “on” power of 11 μW at the detector input. From our photovoltage and resistance maps, alongside the power and waveguide loss calibrations described in Supplementary Note 1/2, respectively. The observed photovoltage gate map indicates a PTE response mechanism, evidenced by the six-fold sign change pattern around the graphene channel’s charge neutral point11. Figure 11.Figure 12 to calculate the electronic temperature distribution and Seebeck photovoltage in the graphene channel under illumination. Figure τeph are established a priori from fitting parameters extracted from the device transmittance and resistance maps, with only τeph obtained by matching the scales of the measured and modeled responsivities. The resemblance between Fig. Tel(x), as well as the source term To confirm our understanding of device operation and elucidate the prospects for performance improvement, we apply the formalism introduced in Song et al.τeph-limited frequency response with an assumed 12. We thus predict a 3-dB cutoff frequency of f−3dB ≈ 1.3 GHz, dominated by the capacitance between the graphene back-gates.Current modulation of our QCL source permits frequency response measurements up to its modulation bandwidth of 1 MHz. To account for the modulation response of our laser, we measure the photovoltage of Device A alongside that of a fast InAsSb photodiode. The comparison shown in Fig. To investigate our device’s noise performance, we modulate the QCL current at 30 kHz, amplify the photovoltage with a low-noise preamplifier and inspect using a signal analyzer. As shown in Supplementary Fig. 16:I0 is the source power, αbase is the waveguide attenuation coefficient in the absence of gas, a is the specific attenuation coefficient of the gas, ng is the guided mode group index, ΓE is the confinement factor of electric field energy within the gaseous medium, and λ = 5.24 μm and a specific attenuation of approximately a ≈ 70 m−1atm−1 at low concentrations17, we arrive at 18. Removing the slightly lossy HfO2 dielectric underneath the gas-light interaction waveguide could decrease 19.To demonstrate our device’s utility, we analyze its predicted gas-sensing performance, summarized from Supplementary Note λ = 5.2 μm by light source availability, the optical conductivity of our graphene inferred from the fitting parameters in Table λ = 10 μm and beyond, perhaps requiring a BaF2 substrate for extended transparency, with little reduction in performance owing to the PTE effect’s thermal nature. In Table 20. Additionally, the vacuum requirement of VOx bolometers may complicate co-packaging and introduce coupling losses, and the high cost of HgCdTe may preclude use in broadly deployed sensor networks.Although our demonstration is limited to 1/2 and a bandwidth exceeding f−3dB = 1 MHz. We have modeled the bandwidth to approach 1.3 GHz and we predict similar performance at longer wavelengths for scaled-up devices enabled by the transparency of GSSe beyond λ = 10 μm21. Finally, we have shown that our device and waveguide platform would enable NO detection at concentrations comparable to its REL. Substantial improvements are likely using metal-insulator-metal10 or dielectric slot waveguides to concentrate the optical mode to within a cooling length of the pn-junction, which would also increase the attenuation of the guided mode and thus decrease the device footprint needed to absorb an optical signal. Gapped bilayer graphene may also be investigated as an alternative to monolayer graphene to reduce thermal noise22. The PIC platform further promises to support a full toolkit of mid-IR active devices including on-chip quantum cascade light sources23, and may even leverage the same graphene material platform for devices such as graphene modulators14 and hot-electron-based24 or gapped bilayer graphene light sources. The platform could also be adapted to alternative mid-IR waveguide approaches, such as suspended Ge, as necessary to reach longer wavelength ranges25. Chalcogenide glass could then supplement such a platform by enabling designs where the graphene channel is sandwiched between the Ge and high-index glass to increase overlap with the optical mode. This research represents the first foray into waveguide-integrated detectors operating beyond λ = 4 μm, paving the way towards 2D-material-enabled integrated mid-IR microsystems for gas sensing, spectroscopy20 and free-space optical communications26.In conclusion, we have demonstrated a PTE-based graphene photodetector, integrated in a scalable chalcogenide glass waveguide platform with an NEP of 1.1 nW/Hz2 in a 1-inch-diameter quartz tube furnace under atmospheric pressure. The furnace was heated to 1060 ∘C over 30 min under 500 sccm of Ar flow; afterwards, 15 sccm of H2 and 10 sccm of dilute CH4 (1% in Ar) were introduced as reducing gas and carbon source, respectively, and flowed for 4 h to ensure the continuity of the graphene film. Finally, the furnace was allowed to cool to 100 ∘C without modifying the gas flow before the CVD graphene was removed from the chamber. Our devices were fabricated on a 1" diameter by 1.0 mm thick (111)-cut CaF2 substrate . We first coated our substrate with a PMMA bilayer for liftoff (495 PMMA A6 followed by 950 PMMA A2), which features a slightly re-entrant sidewall profile after developing. We then performed e-beam lithography using an Elionix FLS-125 125 keV electron beam lithography system to pattern alignment marks on our substrate, followed by room-temperature development in 3:1 isopropanol:methyl isobutyl ketone for 90 s and isopropanol rinse for 120 s (“development process”), e-beam evaporation of 5 nm Ti/100 nm Au  , and liftoff using a 4-h room-temperature acetone soak (“liftoff process”). To transfer the first layer of graphene, we first coated one side of the CVD graphene-on-Cu sheet with PMMA and removed the graphene from the other side using 90 s of oxygen RIE . We then etched away the Cu using a FeCl3-based etchant, followed by 2 DI water rinses, a 30-min clean in 5:1 DI water:HCl 37% in water to reduce metal ion contamination, and two more DI water rinses. After letting the graphene film sit overnight in the final evaporating dish of water, we scooped it out with our CaF2 substrate, blew N2 on the film to eliminate most of the trapped water, and then baked the sample at 80∘ for 30 min followed by 160∘ for 2 h (“graphene transfer process”). We then removed the PMMA from the graphene using acetone at room temperature, rinsed it in isopropanol and blew it dry , and baked the sample at 200 ∘C in N2 for 1 h to improve adhesion. To pattern the graphene back-gates, we spun on a layer of 950 PMMA A6, exposed the gates in the Elionix and developed using “development process”, etched away the exposed graphene using “oxygen RIE process” for 45 s, and removed the PMMA using “PMMA removal process”. We then spun on another 495 PMMA A6/950 PMMA A2 bilayer, exposed the metal contacts to the graphene gates using the Elionix FLS-125, and repeated “development process”, “metal evaporation process”, and “liftoff process”, but using a 2 nm Ti adhesion layer in the Ti/Au stack rather than 5 nm. After this, we evaporated 1.5 nm Al  as an ALD seed layer, allowed the thin Al layer to oxidize in ambient, and deposited 300 cycles ≈ 30 nm of HfO2 ALD at 200 ∘C (Cambridge Nanotech Savannah 200). To define the graphene channel, we performed another “graphene transfer process”, “PMMA removal process”, 1 h N2 ambient 200 ∘C bake, 950 PMMA A6 spin-coating, Elionix FLS-125 exposure of graphene channel pattern, “development process”, “oxygen RIE process” for 45 s, and “PMMA removal process”. To define the channel contacts, we spin-coated another 495 PMMA A6/950 PMMA A2 bilayer, exposed the graphene channel contacts using the Elionix FLS-125, and performed another “development process”, “metal evaporation process”, and “liftoff process”, but using a 2 nm Ti adhesion layer in the Ti/Au stack rather than 5 nm. We then evaporated another 1.5 nm Al seed layer using the Temescal VES2550 and 150 cycles of HfO2 ALD at 200 ∘C using the Cambridge Nanotech Savannah 200 to protect the graphene channel. Finally, to pattern the GSSe waveguides, we coated the chip with 495 PMMA A11, used the Elionix FLS-125 to define the waveguides, and developed in room-temperature 3:1 isopropanol:methyl isobutyl ketone for 120 s followed by an isopropanol rinse for 120 s. The longer development time is mandated by the thicker resist film. We then evaporated 750 nm of Ge28Sb12Se60 followed by a quick liftoff in boiling acetone (~20 min), IPA rinse and N2 blow-dry, and cleaving of the chip to expose waveguide facets.A continuous monolayer graphene film was grown on Cu foil  cut to a size of 15 × 2 cmThe maps in Fig. 27 to model graphene’s conductivity at DC and infrared frequencies :e is the elementary charge, kB is Boltzmann’s constant. As I will show below, graphene’s low-frequency conductivity σDC and infrared conductivity σIR affect various intermediate model parameters; σDC and σIR themselves depend strongly on EF, which features spatial variation due to the back-gates. For the graphene channel, we assume a constant Nc = N0,c  +  e−1CgVg in the region above each gate, where Nc is the carrier concentration in the channel , N0,c is the native carrier concentration at zero gate voltage, Cg is the capacitance per area of the gate dielectric, and Vg is the voltage applied to the gate in question  using ω = 2πc/λ instead of 0 and τIR instead of τDC. Finally, we have 28. Cel is obtained by convolving the heat capacity of pristine graphene with a Gaussian of standard deviation σN as in Eqn. , noting of course that σIR,g(x) = 0 for x within the gap between the gates where there is no graphene. Finally, We use a waveguide eigenmode solver to find the mode profile of our waveguide at κ(x), Cel(x), S(x), Π(x), αc, αg and ρΩ as a function of the gate voltages, as well as τDC, τIR, σn, EFc, EFg, τeph, αe, and ρc, we then solve for the increase in electronic temperature per guided power ΔTel(x)/P = (Tel(x) − T0)/P using the equation:κ is the 2D electronic thermal conductivity of the graphene, τeph is the electron-phonon cooling time, η is the conversion efficiency of absorbed optical power to electronic heat after initial electron-phonon scattering12, Jx is the line current density in the x-direction, and Π is the Peltier coefficient. We are approximating the electric field to run exclusively in the x-direction, valid for sufficiently gradual light absorption. We assume η = 1, as has been previously reported in pump-probe experiments at this wavelength range13. The thermal electromotive force (EMF) arising from the Seebeck effect is then given by:W = 5.4 μm is the channel width and S is the Seebeck coefficient. In Eqns.  are all dependent on the local Fermi level EF of the graphene, and thus have a gate-tunable x-dependence, which we account for in our calculations. Combining the equations, the V is the voltage across the contacts, αc is the component of the waveguide power attenuation coefficient arising from absorption in the graphene channel, P(z) is the guided power at a position along the waveguide, and ρΩ, ρΠ, ρc are the Ohmic, Peltier, and contact line resistivities (dimensions of Ω ⋅ m), respectively. Averaging over z along the length of the waveguide we obtain:I is the current produced by the photodetector, thus describing a Thévenin equivalent source. Here, αtot = αc + αg + αe is the total guided power attenuation coefficient within the detector, including contributions not only from the graphene channel but also from the graphene gates (αg), as well as a gate-independent excess loss αe associated with scattering and absorption from organic or metallic impurities attached to or trapped underneath the graphene sheets. Thus, the total device resistance is equal to R = RΩ + RΠ + Rc, and the voltage responsivity is given by:Having thus obtained expressions for mentclass2pt{minimSupplementary Information