The effects on the CH4 adsorption of ELD graphene when modified by a single Mn atom or two Mn atoms were investigated, respectively. An ELD-42C graphene configuration consisting of 42 C atoms was first constructed. Then, the ELD-42C graphene configuration was used as a substrate, and a Mn-ELD-42C graphene configuration was obtained by modifying it with a single Mn atom. The results showed that the most stable adsorption site for Mn atoms was above the quadrilateral carbon ring. This Mn-ELD-42C graphene configuration could only stably adsorb up to 30 CH4 molecules on each side, with an average adsorption energy of −0.867 eV/CH4 and an adsorption capacity of 46.25 wt%. Three 2Mn-ELD-42C graphene configurations were then obtained by modifying the ELD-42C graphene substrate with two Mn atoms. When the two Mn atoms were located on either side of a 2Mn-ELD-42C graphene configuration and above the two octagonal carbon rings adjacent to the same quadrilateral carbon ring, it was able to adsorb up to 40 CH4 molecules on each side, with an average adsorption energy of −0.862 eV/CH4 and a CH4 adsorption capacity of 51.09 wt%.Extended line defect (ELD) graphene is a two-dimensional (2D) topologically defective graphene with alternate octagonal and quadrilateral carbon rings as basic defective units. This paper reports on the CH It is also a relatively clean fuel, with the lowest rate of CO2 emissions of all carbonaceous fuels [4 adsorption and its storage have important practical significance for energy development and use as well as environmental protection.CHus fuels ,2. It haus fuels ,4. As a 4, with an average adsorption energy of −0.227 eV/CH4. Ghanbari et al. [4. The United States Department of Energy (DOE) established a CH4 storage objective for vehicles in 2012, where the goal was to have a CH4 adsorption capacity of above 50 wt% under standard conditions [4 storage materials still fail to meet this requirement.Graphene is a new kind of two-dimensional (2D) honeycomb-shaped nanomaterial characterized by good mechanical properties, good hydrogen storage and a high sensitivity to as well as adsorption potential for certain types of gases . Zhao eti et al.  used Ti nditions . Unfortu4. Xiong et al. [4 adsorption properties of graphene can be further improved by doping atoms to introduce additional structural modifications. Existing studies on transition metal (TM)-modified ELD graphene have concentrated on the magnetic and electronic properties of the configurations after modification. Cheng et al. [Pristine graphene is composed of a single layer of carbon atoms in the form of sp2 hybrid orbits and has a perfect hexagonal carbon ring structure . During g et al.  construcg et al. . A largeg et al.  found thg et al.  investigg et al.  calculat54s2, with more electrons and empty orbits at the 3d energy level, which helps to enhance chemical bonding between manganese atoms and other molecules, allowing manganese atoms to adsorb gaseous molecules more efficiently [Manganese (Mn) is a transition metal, with reserves of about 570 million tons worldwide, that can be made by aluminothermic reduction of soft manganese ore ,18. Mangiciently ,22. In ticiently ,24.4, working from first principles [4 adsorption properties of ELD graphene modified with a single Mn atom or two Mn atoms and calculates the resulting CH4 adsorption capacity. This study offers theoretical support for the preparation and industrial application of new CH4 storage materials.This paper presents an analysis of the adsorption properties of ELD graphene for CHinciples . It look4 adsorption properties of ELD graphene as well as ELD graphene when modified by a single Mn atom or two Mn atoms at an atomic level by using the Cambridge Sequential Total Energy Package (CASTEP) module in the Materials Studio software [−5 eV/atom; and a self-consistent field (SCF tolerance) convergence threshold of 2.0 × 10−6 eV/atom. To ensure the calculation accuracy and reduce the calculation cost, the truncation energy was set at 450 eV, the K-point sampling was set at 5 × 5 × 1, and the objects of study were integrated in a Brillouin zone with Monkhorst–Pack grids [This paper is based on a first-principles pseudopotential plane-wave (PSPW) method that comes from density functional theory (DFT) ,27. DFT software . Perdew–software , and thesoftware . The conck grids ,35. The An ELD-42C graphene configuration consisting of 42 C atoms was constructed using graphene unit cells, with a main body that was composed of continuous quadrilateral, hexagonal and octagonal carbon rings. Its geometrical configuration after structural optimization is shown in iMn-ELD-42C graphene configurations obtained after modification by the Mn atoms, the binding energy, Mn atoms can be defined as follows:i indicates the number of Mn atoms for modification; iMn-ELD-42C graphene configurations; ELD-42C graphene configurations; and i-free Mn atom(s).For the CH4 molecules in the jCH4iMn-ELD-42C graphene adsorption configurations, the binding energy, j indicates the number of CH4 molecule(s) adsorbed; jCH4iMn-ELD-42C graphene adsorption configurations; j − 1)CH4iMn-ELD-42C graphene adsorption configurations; j-free CH4 molecule(s); and CH4 molecule, each Mn atom and the ELD system, respectively.For the 4 adsorption sites were selected to be studied on account of the symmetry of the geometric structure of the ELD-42C graphene configuration, as shown in 4 molecules adsorbed on the ELD-42C graphene configuration according to the orientations of the four H atoms of the CH4 molecules relative to the plane of the ELD-42C graphene configuration, as shown in 4 molecules on the graphene, not the orientation of H atoms in the CH4 molecules [4 adsorption form with three H atoms orientated to the plane of the ELD-42C graphene configuration . Their adsorption properties for CH4 were then studied.Jia et al.  found thon atoms ,46,47. DWhen the ELD-42C graphene configuration was modified by a single Mn atom, there were six optional adsorption sites for the Mn atoms: the hole sites, H1, H2 and H3; the bridge sites, B1 and B2; and the top site, T1 see . A singlIn the table, 4 molecule was analyzed. It was found that the charge transferred from the Mn atoms to the ELD-42C graphene configuration was 0.69 e, indicating a strong electrostatic effect between the two. The partial density of states (PDOS) for the Mn-ELD-42C graphene configuration is shown in p orbit of the C atoms within the range of −1.958 to −1.381 eV, confirming that there was interaction between the two orbits. As a result, the valence band of the Mn-ELD-42C graphene configuration largely derives from the interaction between the d orbit of the Mn atoms and the p orbit of the C atoms. This is similar to the results obtained by Wu et al. [The Mulliken layout of the Mn-ELD-42C graphene configuration before and after adsorbing a single CHu et al.  and Zhaou et al. , who mod4 adsorption capacity of the Mn-ELD-42C graphene configuration by adding CH4 molecules to one side. A stable CH44 molecule had been optimized. The first CH4 molecule was located above the Mn atom, proving that this was where the adsorption energy was the largest. The adsorption energy of this configuration was −1.717 eV, which is larger than that of the ELD-42C graphene configuration for CH4 molecules (−0.847 eV), of Li-modified carbon nanotubes for CH4 (−0.464 eV) [4 (−0.488 eV) [4 molecules. A 2CH44 molecule had been added . When a 17th CH4 molecule was placed on one side of the configuration, the calculated adsorption energy became positive, indicating that the gas molecule had not been adsorbed. This proved that the Mn-ELD-42C graphene configuration could only stably adsorb up to 16 CH4 molecules on each side. The geometrical configuration is shown in DFT was used to study the CHguration a was obt.464 eV)  and of P.488 eV) . Apparenen added b. Here, Mn atoms c. A four C atoms d, and a  C atoms e. Limiteadsorbed f, and thadsorbed g. Due to44 adsorption configuration for CH4 adsorption on one side and both sides; the distance, 4 molecules and the plane of the Mn-ELD-42C graphene configuration; the distance, 4 molecules and the Mn atoms; and the adsorption capacity (PBW) of the Mn-ELD-42C graphene configuration for CH4 in the jCH44 adsorption configuration. Analysis of these data reveals that the absolute value of the average adsorption energy, 4 gradually decreased as j, the number of CH4 molecules adsorbed, increased. The adsorption energy, 4 molecules adsorbed on one side was compared. When the gas molecules were not stratified (the first–eighth molecules), the first, third, and seventh CH4 molecules presented a higher adsorption energy than the other CH4 molecules because their adsorption sites were close to Mn atoms and their distance from the plane of the graphene configuration was relatively small. When the gas molecules were stratified (the ninth–sixteenth molecules), the interaction between the CH4 and Mn steadily decreased as the distance between them increased, leading to reduced adsorption properties.4 adsorption. The adsorption energy was also affected by the distance between the CH4 molecules and the plane of the graphene configuration. The adsorption distance, 4 molecule and the Mn-ELD-42C graphene configuration was 11.550 Å, which was the largest out of the 16 CH4 molecules. At this point, both the average adsorption energy, 4 and −0.755 eV, respectively).The above results indicate that the adsorption properties of a Mn-ELD-42C graphene configuration are affected by Mn atom modification and that this can play an important role in CH4 molecules could be stably adsorbed on one side of the Mn-ELD-42C graphene configuration, with an average adsorption energy of −0.897 eV/CH4. On this basis, it can be calculated that the Mn-ELD-42C graphene configuration is able to stably adsorb up to 14 CH4 molecules on the other side, making a total of 30 CH4 molecules overall (4 and an adsorption capacity of 46.25 wt%. This is much closer to the proposed DOE standard (50 wt%) [4 molecules can be effectively improved by the modification of Mn atoms.Up to 16 CH overall , with an4 molecule, where H1, H2, H3 and H4 stand for the H atoms and C represents the C atom of the CH4 molecule. For the CH4 molecule adsorbed above the Mn atom, H1, H2 and H3 faced the plane of the Mn-ELD-42C graphene configuration, while H4 faced away from it  peak of the Mn atoms increased from 4.031 eV  after optimization is shown in 4 molecule was adsorbed by the 2Mn-ELD-42C graphene configuration, stratification occurred due to the repulsion between the positively charged surfaces of the CH4 molecules and the limited adsorption space near the Mn atoms  of the 2Mn-ELD-42C graphene configuration. It can be seen that the absolute value of the average adsorption energy decreased with an increase in j, the number of adsorbed CH4 molecules. Comparing the adsorption energy, 4 molecules adsorbed on one side and in a single layer, the first and fourth CH4 molecules were closer to the Mn atoms and had smaller adsorption distances from the plane of the graphene configuration, so there was a higher adsorption energy. The adsorption distance between the 20th CH4 molecule and the 2Mn-ELD-42C graphene configuration was the largest out of the 20 CH4 molecules (11.600 Å), with the average adsorption energy, 4 and −0.726 eV, respectively). Layered adsorption occurred when the CH4 molecules were adsorbed by the 2Mn-ELD-42C graphene configuration, causing the 20th CH4 molecule to be the farthest away from Mn atoms; there was repulsion between the positively charged surfaces of the CH4 molecules, making the adsorption energy the lowest. When a 21st CH4 molecule was placed on one side of the configuration, the calculated adsorption energy became positive, indicating that the gas molecule had not been adsorbed.4 molecules could be stably adsorbed on both sides of the 2Mn-ELD-42C graphene configuration  was close to that of the Mn-ELD-42C graphene configuration (−0.867 eV/CH4), the CH4 adsorption capacity of the 2Mn-ELD-42C graphene configuration (51.09 wt%) was 1.11 times that of the Mn-ELD-42C graphene configuration.Up to 40 CHtion see , with an4 adsorption capacity of the 2Mn-ELD-42C graphene configuration is lower than some references, as tabulated in Although the CH4 adsorption properties of ELD-42C, Mn-ELD-42C and 2Mn-ELD-42C graphene configurations using DFT to work from first principles. The study results showed that the CH4 adsorption of a basic ELD-42C graphene configuration is weak. Here, the average adsorption energy was −0.842 eV/CH4, and the CH4 adsorption capacity was 45.26 wt%. Sixteen CH4 molecules could be stably adsorbed on the Mn-doped side of the Mn-ELD-42C graphene configuration, and fourteen on the other side, with an average adsorption energy of −0.867 eV/CH4 and an adsorption capacity of 46.25 wt%. Thus, the CH4 adsorption capacity of Mn-ELD-42C graphene configurations can be effectively enhanced by modification with a single Mn atom. This configuration further improved the CH4 adsorption and increased the number of adsorption sites, with it being able to stably adsorb up to 40 CH4 molecules across the two sides, with an average adsorption energy of −0.862 eV/CH4 and an adsorption capacity of 51.09 wt%. The adsorption capacity of the 2Mn-ELD-42C graphene configuration was 1.13 times that of the ELD-42C graphene configuration and exceeded the proposed DOE standards (50 wt%). Together, these results indicate that 2Mn-ELD-42C graphene configurations have great potential for the development of industrially viable CH4 storage materials. The DFT calculation results in this paper only illustrate the CH4 adsorption properties of ELD graphene configurations when modified by a single Mn atom or two Mn atoms. In subsequent studies, the effects of environmental factors such as temperature and pressure on the CH4 adsorption properties of ELD-42C, Mn-ELD-42C and 2Mn-ELD-42C graphene configurations will be further investigated using molecular dynamics methods.This paper explored the CH


In this study, the effects of graphene and design differences on bow-tie microstrip antenna performance and bandwidth improvement were investigated both with simulation and experiments. In addition, the conductivity of graphene can be dynamically tuned by changing its chemical potential. The numerical calculations of the proposed antennas at 2–10 GHz were carried out using the finite integration technique in the CST Microwave Studio program. Thus, three bow-tie microstrip antennas with different antenna parameters were designed. Unlike traditional production techniques, due to its cost-effectiveness and easy production, antennas were produced using 3D printing, and then measurements were conducted. A very good match was observed between the simulation and the measurement results. The performance of each antenna was analyzed, and then, the effects of antenna sizes and different chemical potentials on antenna performance were investigated and discussed. The results show that the bow-tie antenna with a slot, which is one of the new advantages of this study, provides a good match and that it has an ultra-bandwidth of 18 GHz in the frequency range of 2 to 20 GHz for ultra-wideband applications. The obtained return loss of −10 dB throughout the applied frequency shows that the designed antennas are useful. In addition, the proposed antennas have an average gain of 9 dBi. This study will be a guide for microstrip antennas based on the desired applications by changing the size of the slots and chemical potential in the conductive parts in the design. Microstrip patch antennas are used in aviation and satellite communication, biomedical, radio, and wireless applications due to their important features such as reduced size, weight, and cost . HoweverThe compactness of the microstrip antennas is an important feature . Typical2Vm, it has a unique quantum Hall effect, good flexibility, and excellent mechanical resistance, which provides many advantages for different areas such as nanoelectronics, material science, photovoltaics, and engineering. Another important feature is that it has a thermal conductivity of more than ten times copper [Previously, two physicists at the University of Manchester in 2004 discovered that graphene could be obtained by isolating a one-atom-thick layer from graphite. The second one is a simple two-dimensional sheet shaped in a hexagonal pattern consisting of carbon atoms . Since is copper . Additios copper ,19,20.A reconfigurable antenna is defined as an antenna in which at least one of its features can be changed by external intervention after its production is completed. There are many ways of classification of these reconfigurable antennas. Here are a few examples in order: It can be listed as causing the antennas to be changed again , having the elements that allow the change  or changing the geometric structures of the antennas again. Various techniques are used in antenna reconstruction methods. Some researchers use localized active components that allow changing half-point current or impedance lines , others Using graphene provides a great advantage to antenna designs because it has an efficient dynamic tuning ,32. The The frequency-dependent two-dimensional surface conductivity of single-layer graphene is expressed by the Kubo formula (Equation (1)) :(1)σVg=[Inum et al. give the real and imaginary values of the surface conductivity of graphene depending on the frequency for a changing chemical potential and a constant relaxation time at their study . They shIn a study , the antA traditional microstrip patch antenna has a high-quality factor, leading to some disadvantages related to the narrow bandwidth. Many techniques have been developed to increase the impedance bandwidth, including adopting the known stacked patches , parasitMetamaterial-based absorbers and antennas with different fractal structures are being studied to expand the bandwidth ,42. WhilIt is known that all conventional antenna manufacturing techniques have disadvantages such as high tool and equipment cost, small volume prototyping, or long lead times for production ,44,45,46Recently, the expansion of 3D printing offers new chances for low-cost, fast, and on-demand production of millimeter-wave, microwave, and terahertz (THz) antennas and components ,48,49,50There are two widely used 3D-printing techniques ,59,60,61Microstrip antennas have become remarkably interesting in that they can be used in many different application areas owing to their wide operating bandwidth and easy adjustment alternatives ,64,65,66It is well known that the bow-tie antenna designs are application-specific, and the slots are added to increase the bandwidth. Therefore, two parameters need to be well specified for better performance: the location and size of the slot. One of the contributions of this study is that the slot dimensions are chosen especially for the required bandwidth and gain.Graphene-based antenna studies have been carried out intensively, especially for the last five years ,84,85,86In this study, Esun PLA Plus Filament  was preferred for the substrate material of the antenna due to its high surface quality, high layer structure, and ten times more durability than standard PLA filaments. Detailed information on Physical and Print performances is given in Black Magic 3D Conductive Graphene Composite filament is used for the conductive part of the antenna due to its superior conductivity and improved mechanical properties, and its detailed properties are given in The bow-tie microstrip patch antenna design procedure is given in In this section, the parameters affecting the configurability of the graphene-based antenna are evaluated. The first of the two kinds of parameters are related to the geometric structure of the antenna, and it can be optimized with numerical simulations, while the other is related to the graphene model related to the calculation in the previous section. The study aims to understand the behavior of the graphene-based antenna and contribute to future studies of graphene-based antennas.A bow-tie microstrip antenna structure is planned to improve the antenna’s performance in biomedical applications. The design and simulation study of the proposed antenna is carried out in the CST Microwave Studio. The antennas are designed in Tinkercad, which is an online 3D design platform developed by Autodesk Inc.  and built with Creality Ender 3 Pro 3D printer .r = 2.54 and tanδ = 0.015) and Acrylonitrile Butadiene Styrene (ABS) are effective on the antennas’ performance. They are frequently preferred in the production of dielectric parts of antennas and microwave components. On the other hand, graphene is a suitable material for producing the conductive part of Microwave and Radio Frequency (RF) products due to its very good properties such as high charge mobility, zero bandgap, high heat conduction, high surface area, and excellent biocompatibility. Composite Conductive Graphene PLA filaments have recently been introduced, allowing graphene to be used with a 3D printer [Material selection is one of the pivotal problems to be considered in the design process, as it has a significant impact on antenna performance. Polylactic Acid (PLA; ε printer . In this printer . The pro printer ,91,92, aThe radiating patch of the microstrip antenna may be square, rectangular, circular, elliptical, triangular, or any other shape . GeneralIn this study, three different antennas, one without a slot, The three bow-tie antennas produced for use in biomedical applications are shown in An SMA connector is connected to the antenna’s terminals by heating and softening the graphene; see The microwave antennas’ design and dimensions were optimized through the simulations using the CST Microwave Studio software. The CAD design was prepared using Tinkercad, and Ultimaker Cura was used to generate gcode for the 3D printer. A commercial Creality Ender 3 Pro printer was utilized to manufacture a 3D printed substrate part from PLA and a conductor part from graphene. The bed and the nozzle temperatures were adjusted as 60 °C and 205 °C, respectively for the PLA and 50 °C and 220 °C for the graphene. An intermediate printing head speed of 50 mm/s and 30 mm/s was selected for PLA and graphene, respectively. A nozzle with 0.5 mm size is used for the printing. In addition, it was also investigated how the changes to be made in antenna geometries, especially in the graphene patch part, can affect the cross-sectional absorption areas. The physical parameters for all antennas are assumed to be Before interpreting the results, the measurement device and its arrangement mentioned in the previous section are shown in The reflection coefficients of Antenna-1, Antenna-2, and Antenna-3 are given in It has been shown that the polarization and permeability of the antennas can be achieved without making any changes in the antenna dimensions or physical structure only by changing the voltage applied to the graphene layer, which changed the Fermi energy level ,95,96,97Although the results of the simulation and experimental studies are generally compatible, minor inconsistencies may occur. Simulation environments are ideal environments, and the values of materials used in simulation environments are average values. There are slight differences between the values of PLA and graphene material used in the simulation environment and the materials used. In addition, minor faults caused by production, such as scratches or difficulties in soldering the SMA connector, can lead to different results. Another important situation is that this study used a graphene filament for antennas instead of the raw graphene material.The comparison for efficiency and performance of graphene-based bow-tie antennas with previous ultra-wideband antennas are given in In order to demonstrate the effect of graphene in one of the graphene-based antenna studies, the study was carried out by choosing copper as the conductive patch part . From thAdditionally, the comparison of the antenna produced in this article with the previously studied antennas is given in Graphene is preferred in antennas due to its many important potentials, such as reducing antenna sizes, providing good integration with electronic circuits, dynamic adjustment possibility, transparency, and flexibility . The mosGómez-Díaz and Perruisseau-Carrier carried out the first graphene-based patch antenna in their study . They prIn another study, an antenna with a diaphragm connection was produced to be used in the band from 14 to 16 GHz . In thisficiency .In summary, three different bow-tie microstrip antennas that can operate in the 2–20 GHz range for ultra-wideband applications have been designed and experimentally implemented. Numerical analyses were made using the finite integration technique in the CST Microwave Studio simulation program. The designed antennas were selected from the non-slot state, and the radiating part was selected with two different slot sizes and produced from graphene filament. The substrate is produced from PLA material. It has been observed that all three designs perform quite well in ultra-wideband applications. The effect of design differences in antennas is reflected in antenna return losses. Especially for Antenna-1, the return loss seems to be quite good. In addition, copper is generally used for the radiating part in classical methods. This study has also shown that graphene performs better than copper because it is a good conductor, contrary to classical methods.Another critical point is that the production of 3D-printer technology is one of the new aspects of the proposed study, as it is cost-effective and easy to produce, unlike classical production methods. In addition, the voltages applied to graphene changes the chemical potential and cause changes in the permittivity of graphene. In this respect, it has been a critical study to provide the opportunity to create different frequency ranges. It is considered to use one or more of these produced antennas for biomedical UWB applications for future studies.


The impact of the COVID-19 pandemic has highlighted the need to strengthen health communication in times of crisis. This study aims to analyze the media agenda of press conferences on COVID-19 in Mexico during the first two phases of the pandemic, based on journalists’ questions. The study is based on framing theory. The method used was content analysis from a quantitative perspective. This method was explicitly applied to the final section of the conferences, which dealt with “questions from the press.” The results show that at the beginning of the pandemic, the press was more interested in the government’s management of the health crisis than in issues such as the prevention of the disease itself or the economic impact of the crisis on the country. Moreover, the main characteristic of the questions was that they were generally socially relevant. In conclusion, we found that in the media agenda of the Mexican conference, the frame of attribution of responsibility was prominent but in combination with the frames of conflict, human interest, morality, and economic consequences. The imprint of the COVID-19 pandemic has made visible the need to strengthen health communication in times of crisis. According to Silva et al. , what is going to be done?” or “What would be the strategy suggested to the states for people in street situations?” Moreover, finally, there are questions about the impact of the crisis on the economy: “How do the new measures affect the private and public sector?” or “How could companies act, can they lower wages after today’s measures?” The When analyzing the themes of the questions, it was observed that of the total number of questions on the impact of the crisis on the economy, 74.3% were asked in phase 1, and only 25.7% were asked in phase 2. In general, few questions addressed this issue: only 35 out of 738 questions were asked. In contrast, concerns about risk and vulnerability increased as the conferences progressed: only 27.9% were asked in phase 1, while phase 2 accounted for 72.1% of the total number of questions. The rest of the issues identified behaved similarly in both phases, with no significant percentage difference. These percentages are represented in On the other hand, interest in governmental management of the crisis was also prominent in all media. The most notable of these were questions on the statistics of the disease in the following media: Reforma (38.6%), La Jornada (37.9%), Milenio (28.6%), and Grupo Imagen (27.8%); while questions on communication and health education were the most notable in Uno TV (34.6%), La Jornada (29.3%), and Plenilunia (25%). Similarly, questions about the characteristics of the disease stood out among Excelsior (20%) and Plenilunia (18.2%). In contrast, questions about politics and officialdom were more frequent in MVS Noticias (38.9%) and Notimex TV (19.2%).Of the 738 questions registered, more than half (54.5%) had social relevance in that they clarified doubts or dealt with issues of public interest. In turn, almost a quarter of the questions were related to that day’s conference (24%) and an event in the last 24 h (24.1%). An example of the latter was when a journalist asked the Undersecretary of Health, Hugo López-Gatell, to respond to a negative comment about his work: “Yesterday […], a TV host was talking about you, precisely about not paying attention to you as a health authority, can you give us your point of view?”Sensationalist overtones were also found in some questions (18.2%), such as: “Can you give us an estimate of how many deaths there will be, tens, thousands or millions? I mean to reassure people”. In addition, another day, a journalist urgently wanted to know if a patient had died recently, when perhaps not even the family knew: “Now that it is 7:38, […] with all due respect if you can confirm before the end of the conference if the person died?”Some questions became repetitive (21.8%), especially on topics such as the sentinel model adopted by the country and the purchase and management of supplies, or statistics, which could be less comprehensible at the beginning of the pandemic. Questions addressed to other secretariats (8.3%) were the least common because most of the questions were addressed to officials of the Health Secretariat, which was the institution organizing the conference, and whose officials attended the conference daily.In terms of other data on journalistic work, one-third of the questions asked used verified sources (34%) to argue them or give them greater credibility. Very few questions alluded to rumors (4%), either clarifying them or giving them a voice. An illustrative example was when a journalist asked: “Milenio talks about a hospital in fear of the virus. Can you corroborate if it is true that it takes five days for patients to get their test results?” These percentages are represented in When analyzing the characteristics of the questions concerning other variables of the study, we found that at the beginning, questions related to an event in the last 24 h were more frequent: 59.6% of the questions were asked in phase 1, and 40.4% were asked in phase 2. Reiterative questions were also more frequent in the initial phase: 71.4% of the total corresponding to phase 1 and only 28.6% corresponded to phase 2. As time went on, journalists diversified their questions and topics.Among the characteristics of the questions, it has been observed that in all the media, questions with social relevance stood out, except in the cases of repetitive questions, which were more common in Grupo Imagen (77.8%) and those related to some event in the last 24 h in MVS Noticias (55.6%). Following these, the most notable were those related to the theme of that day’s conference, on Uno TV (34.6%), La Jornada (32.8%), and Reforma (30%), while those related to an event in the last 24 h were the second most notable on Canal Once (34.1%), Milenio (33.7%), and Notimex TV (30.8%). Moreover, questions with sensationalist overtones were most common on Excelsior (48%).When we analyzed the themes and characteristics of the questions together, we found that 50% of the questions on politics and officialdom had sensationalist overtones. In addition, 40% of the questions were addressed to other secretariats, and 21% of the questions related to an event in the last 24 h were about politics and officialdom. On the other hand, questions about disease statistics accounted for 31% of those related to the theme of that day’s conference, 30% of those related to an event in the last 24 h, 28% of those that were repetitive, and 24% of those with social relevance. These percentages are represented in At the beginning of the conferences, economic issues were more present in the journalists’ questions, demonstrating the uncertainty about the impact of the health crisis on the economy. In addition, the progressive reduction of questions on the impact of the crisis on the economy and the increase in questions on risk and vulnerability shows the shift of concerns toward the impact of the health and economic crisis on specific groups, such as essential workers, the unemployed, dependents, the homeless, or women.In terms of media performance, it is interesting that La Jornada, Uno TV, Excelsior, Grupo Imagen, and MVS Noticias were among the ten media outlets whose journalists asked the most questions in general; and at the same time, none of their questions were about the impact of the crisis on the economy. In turn, these data are very illustrative of the sensitivity of the mainstream media to the consequences of the health crisis on the most affected sectors of the population. In contrast, Plenilunia, a small, independent media outlet, is among the most interested in questions about the characteristics of the disease itself. Finally, the fact that questions with sensationalist overtones are the most common among Excelsior journalists is a sign of how they construct the media agenda during a health crisis, regardless of the consequences. Let us remember that Excelsior, since its beginnings, has been a newspaper characterized by its conservative stance ).In addition, the fact that at the beginning, the questions were more related to some event in the last 24 h is an example of the spontaneity in the construction of the agenda, as a reflection of the generalized uncertainty and, in this framework, the relevance of any event. The same goes for repetitive questions (which were more frequent at the beginning of the pandemic). As a subject that journalists had little knowledge of, there were more doubts at the beginning and precisely because of its novelty. In addition, the concomitance between questions about politics and officialdom and questions with sensationalist overtones could point to a close relationship between these two types of questions.These results illustrate the role of the press in the management of the coronavirus crisis in Mexico and elsewhere in the world. Heras-Pedrosa et al.  point ouThe thematic classification of the journalists’ questions shows that of the five frames proposed by the framing theory —the attrThe themes favored in the analyzed questions coincide with those prioritized in other media on COVID-19 in other countries. In a reflection on the pandemic, Balog-Way and McComas  identifiThe journalists’ questions also placed the issues of risk and vulnerability associated with COVID-19 in Mexico on the media and public agenda. However, it was a topic that was dealt with to a lesser extent than others, such as government management of the crisis or statistics on the disease. In this regard, a comparative public good communication study between Argentina and Spain highlights that it has not yet been generated the space for the economic, social, and psychological consequences that COVID-19 is causing: increased poverty and gender violence, depression, anxiety, worry, uncertainty .Segura  refers tIn conclusion, the journalists’ questions were more focused on the government’s management of the health crisis, and to a lesser extent, on the disease itself or the political and economic repercussions of the health crisis in the country. Similarly, the press played a significant role at the beginning of the pandemic by putting public, media, and political interest issues on the public agenda. However, the media agenda of the press conferences has reflected the spontaneity with which the situation was handled, which was typical of crisis contexts. These data are also indicators of the lags in health communication compared to other areas of communication.However, the data analysis made it possible to achieve the proposed objective of characterizing the media agenda of the press in the Mexican government’s press conferences on COVID-19 in the first two phases. One of the main contributions of this characterization is that it provides data on the limits and strengths of the Mexican press’ actions in the face of the COVID-19 crisis. These data allow us to understand how the press has contributed to, and at the same time hindered, the overcoming of the crisis. These results also serve to review what has been done, learn from it, and improve future action.This work also helps identify the extent to which the media influence the formation of Mexican public opinion in the face of the COVID-19 crisis, especially in its early stages. The data show that the media did not question the press conference as a space for official communication. Instead, they used it to attack the government, sometimes to misinform and make political noise, rather than help the conference fulfill its objective of informing and debating the disease and its economic impact.The government’s performance at the conferences also contributed to this situation by using it for its legitimization. In other words, both the Mexican government and the journalists used the space to pursue their information interests. In this way, the crucial issues of the disease were not prioritized either by the media or by those in power, thus affecting the processes of communication and health education of the population.An example of this distortion of issues occurred with the debate on the appropriateness of using masks, which was not exclusive to Mexico but occurred internationally. In that case, instead of reporting on the ideas contained in the controversy, the Mexican media defended its use, and others did not attack the opinion of certain politicians or officials. This is the case of the Undersecretary of Health, who argued that “its use was not scientifically proven to be effective.” In general, the media turned to attacking him rather than contradicting him, but at the same time reporting the importance of using it for health care as other specialists were recommending.Instead, in these cases, the focus was on attacking and sensationalizing public officials’ headlines because that attracted more public attention. In this way, the media was more about attacking the politician than verifying or contrasting information and pointing blame rather than reporting or at least questioning or scrutinizing communication and health policies.In turn, this idea justifies the need to develop training plans for media communication professionals on information, education, and communication for health. As this study demonstrates, journalists or communicators play a fundamental role in these cases, as they are the ones who have the possibility of bringing the state’s actions into the debate and at the same time giving voice to the concerns and needs of the population.In addition, the study’s main limitation is that it only covered the first two phases of the pandemic. Thus, phase 3 and the new normal were left out of the study. In this sense, work is recommended to continue the missing phases to complete the conferences’ systematization. This effort would make it possible to identify the regularities that characterize the role of the Mexican press, not only at the beginning of the pandemic but also up to the present day, and even to make a comparison from beginning to end once the crisis has been overcome.


Ninjin'yoeito, a Kampo prescription, was administered to two patients with idiopathic pulmonary fibrosis (IPF) over a period of 12 weeks to improve loss of appetite and lassitude. In Case 1, improvements were observed in appetite, lassitude, and breathlessness, as well as increases or increasing tendencies in body weight, blood albumin level, and hemoglobin (Hb) level. Case 2 showed no changes in appetite but improvements in lassitude and no deterioration of breathlessness. His body weight and his blood albumin and Hb levels increased or showed increasing trends. In both cases, a trend for improvement of respiratory function was observed. In summary, ninjin'yoeito trended to improve the subjective symptoms and nutritional status of a patient with pulmonary fibrosis. Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive disease in which advanced fibrogenesis results in irreversible honeycomb lungs. Antifibrotic agents can be used to treat IPF but the efficacy is limited. The mean lifespan after diagnosis of IPF is 3–5 years; and the mean lifespan after exacerbation of IPF is 2 months or less. IPF is associated with a very high mortality rate . AccompaCase 1 was a 59-year-old male with a history of rhabodomyolysis. The patient was referred to our hospital because of gradually progressive dyspnea on exertion. His height was 155.5 cm, the body weight was 51.8 kg and the percentage of oxygen saturation SpO2) was 95%. His respiratory test results are shown in  was 95%.Case 2, a 59-year-old male was referred to our hospital for respiratory failure and was clinically diagnosed as IPF based on the guidelines [Raghu et al. .His height was 167.5 cm, the body weight was 50.2 kg and the SpO2 was 90%. His respiratory test results are shown in 2 receptors  for the publication of any potentially identifiable images or data included in this article.HK conducted the study and wrote the manuscript. HI and MF instructed the study. All authors contributed to the article and approved the submitted version.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.


In this study, a graphene beam was selected as a sensing element and used to form a graphene resonant gyroscope structure with direct frequency output and ultrahigh sensitivity. The structure of the graphene resonator gyroscope was simulated using the ANSYS finite element software, and the influence of the length, width, and thickness of the graphene resonant beam on the angular velocity sensitivity was studied. The simulation results show that the resonant frequency of the graphene resonant beam decreased with increasing the beam length and thickness, while the width had a negligible effect. The fundamental frequency of the designed graphene resonator gyroscope was more than 20 MHz, and the sensitivity of the angular velocity was able to reach 22,990 Hz/°/h. This work is of great significance for applications in environments that require high sensitivity to extremely weak angular velocity variation. Resonant gyroscopes with direct frequency output can directly convert a weak Coriolis angular velocity into a frequency-modulated wave by frequency modulation and demodulate a frequency-modulated wave to calculate the input angular velocity. Compared with the conventional amplitude modulation detection method, it has the characteristics of high precision, good stability, low power consumption, and small drift. It can also further improve the gyro test accuracy when new materials with excellent structural characteristics are selected. The birth of graphene materials makes it possible to develop a resonant gyroscope with a direct frequency output that is sensitive to ultraweak angular velocity variation.2 insulating layer via intermolecular van der Waals forces to form double-clamped graphene beams. Gold electrodes set at both ends of the SiO2 layer allowed the resonator to vibrate within the MHz range upon electric excitation. The frequency of the single-layer graphene resonator was 70.5 MHz, and the quality factor (Q) was about 78. This experiment provided important support for the subsequent design and experiments using graphene resonators.In 2004, the physicists Konstantin Novoselov and Andre Geim from the University of Manchester successfully peeled single-layer graphene from graphite for the first time . GraphenIn 2009, Chen et al. of Columbia University developed a single-layer graphene resonator with an electrical readout. The research group experimentally tested the variation of the resonant frequency of the graphene resonator with the additional mass, external temperature, and voltage of the silicon electrodes . In 2012In summary, graphene resonators have been developed well in the fields of inertial navigation ,11,12 anOn the basis of the principle of resonant gyroscopes for MEMS with direct frequency output and the model of graphene resonators, a graphene resonant gyroscope was designed. By simulating the influence of the length, width, and thickness of the graphene resonant beam on the resonant frequency of the gyroscope sensor, an optimized finite element simulation structure for the graphene resonant gyroscope was obtained.The concept of resonance has been well applied in the drive and detection modes of resonant gyroscopes with direct output frequencies. Through detecting the change in the resonant frequency of the resonator, the input can be measured, which is an FM (frequency modulation) detection method. Unlike other MEMS sensors that detect weak capacitance analog signals, this FM detection method converts the weak Coriolis force into FM waves and then calculates the angular velocity load by demodulating the FM waves. Compared with the conventional amplitude modulation detection method, this detection method has high accuracy, a large dynamic range, low noise, and low power consumption. In 2002, the University of California, Berkeley, designed the first integrated micromechanical gyroscope with direct output frequency detection ,15; the y-axis direction with its resonant frequency under the action of an external driving force, while the two axisymmetric resonators, DETF (double-end tine fork), vibrate in the reverse direction, with their resonant frequency under the action of the driving force. When the angular velocity along the z-axis is generated, according to the principle of the Coriolis effect, the Coriolis force is generated on the mass along the x-axis of the plane perpendicular to the y-axis of the relative motion direction and the z-axis of the angular velocity direction. The periodic pressure or tension generated by the driving mass acts on both ends of the DETF such that the resonant frequency of the DETF changes. The frequency variation of the DETF is proportional to the Coriolis force; thus, the loading angular velocity can be demodulated. Here, y0 is the maximum amplitude of the mass block, y is the displacement of the mass block in the y-axis direction, dw is the driving frequency of the mass block, M is the mass of the mass block, and Ω is the angular velocity that is set at a constant value. Combining the vector derivative with Newton’s second mechanical equation, the Coriolis force can be expressed as follows:As shown in BV, as the relative velocity of the mass block relative to the frame, can be expressed as follows:cF can be rewritten as the following:Then, the Coriolis Force At present, there is no perfect theoretical model for the study of graphene resonance characteristics. The research methods described in the literature mainly include the traditional continuum model , the sem(a)The central inertia axis of each section of the beam is in the same plane, and the beam moves laterally in this plane.(b)The ratio of the cross-sectional area size of the beam to its length is relatively small, and the influence of shear deformation and the moment of inertia around the central axis of the section can be ignored.(c)The transverse vibration of the beam conforms to the assumption of small deflection plane bending, i.e., the amplitude of the transverse vibration is very small and within the linear range.When analyzing the lateral bending free vibration of the beam, the following assumptions are first introduced:According to the above assumptions, the structural dimensions of the graphene resonance beam designed in this paper are shown in L, b, and h, respectively. The microelement dx was chosen as the object of study; t, and x at time t. The vibration equation of the graphene resonant beam can then be approximated as follows [ρ is the density of graphene, A is the cross-section area of the beam , E is the Young’s modulus of the beam, I is the moment of inertia of the cross-section of the beam to the neutral axis , and T is the axial force acting along the x-direction of the resonant beam in the units N. The solution of the equation is given as follows:ω is the natural frequency of the resonant beam in rad/s. Combining Equation (6) with Equation (5), the mode function becomes the following:The length, width, and thickness of the graphene resonant beam are  follows :(5)EI∂4yT can be derived. The first-order bending vibration frequency is given by the following:f0 represents the first natural frequency when the axial force T = 0, and xε represents the axial strain of the beam as follows:According to the boundary condition of the double-clamped beam, the natural frequencies of double-clamped beams under axial force (a)On the basis of silicon-based materials, single graphene beams are supported by intermolecular van der Waals forces in the etched grooves of the Si transfer beams, as shown in (b)y-axis direction. When the angular velocity in the z-axis direction is generated, as stated in Equation (1), the Coriolis force is generated in the x-axis direction.The mass block is driven to move in a simple and harmonic way in the (c)x-axis direction of the symmetrical Si transfer beam, which causes the Si transfer beam to generate axial strain, which in turn causes an axial stress change in the double-clamped graphene beam on the Si transmission beam, effectively changing the resonant frequency state of the graphene.The Coriolis force passes through the (d)As stated in Equation (4), the magnitude of the angular velocity is demodulated by tuning the direct output frequency.On the basis of the principle of resonant gyroscopes with direct frequency output described in The axially symmetrical graphene beams are stretched and compressed in the working state, and the reciprocating motion realizes differential detection, which reduces the common mode interference. The resonant frequency of graphene is very high, which can respond to changes in the small Coriolis force, thus realizing ultrahigh sensitivity. A graphene resonant beam is the core sensitive element of a resonant sensor, so its dynamic characteristics are very important. Since the thickness of a single graphene layer is only 0.335 nm—much lower than the minimum meshing size in the ANSYS finite element software—it is not possible to directly use the “Solid” module in the software for modeling. In this study, a rectangular graphene resonant beam structure was constructed using the “beam” or “shell” provided in the software. Its thickness value was directly set in the setup window, which simplified the geometric modeling process and meshing, in addition to improving the efficiency of solving. The thickness of all silicon structures is 3um. The geometric parameters and material properties of the silicon base and graphene resonator beams are shown in Residual stress is generated during the preparation of graphene materials and the transfer of graphene materials to the Si substrate. Such residual stress has a great influence on the detection of the resonant frequency of the graphene material; hence, it is necessary to optimize the process during the preparation and transfer process to reduce the influence of the residual stress. At the same time, due to the influence of the processing technology, the residual stress of the graphene materials produced by each batch of processing is not completely identical, and the influence of the residual stress can be reduced but cannot be completely eliminated. In this study, we minimized the effect of residual stress on the resonant frequency of graphene, and we simulated and analyzed the situation where the most ideal stress was 0. To verify the validity of this method, experimental data from published papers were compared, as shown in Using the above model, the influence of the structure parameters of graphene resonator beams on the angular velocity sensitivity was studied. In Through the simulation analysis of the angular velocity sensitivity of the geometric size of the graphene resonator beam, it was found that the length change in the graphene resonator beam had a greater influence on the angular velocity sensitivity. When the angular velocity was converted to the Coriolis force acting on the graphene resonator beam, with In this study, a graphene resonant gyroscope structure with a graphene beam resonator was designed. Theoretical analyses and finite element simulations of the graphene resonant beam structure and the graphene resonant gyroscope were carried out. The fundamental frequency of the graphene resonant gyroscope was determined to be more than 20 MHz, and the sensitivity of the angular velocity was able to reach 22,990 Hz/°/h. It was found that the length and thickness of the graphene resonant beam both affected the sensitivity of the sensor. The sensitivity decreased upon increasing both the length and the thickness of the graphene resonant beam. This work provides a theoretical basis for the design of an ultrahigh-sensitivity graphene resonator gyroscope that is sensitive to very weak angular velocity variation.


Nano-graphene-based energetic materials, as a new type of composite energetic materials such as desensitizer and combustion catalyst, have attracted extensive attention from energetic researchers. In this paper, the preparation of nano-graphene-based energetic materials, the desensitization effect of nano-graphene-based on energetic compounds, the thermal decomposition and combustion behavior of the materials are reviewed. Meanwhile, the existing problems and future development of nano-graphene-based energetic compounds are discussed. In modern war, the increasingly harsh battlefield environment brings unprecedented challenges to the battlefield survivability of combatants and weapon platforms. It is urgent to improve the storage and use of the safety of weapons and ammunition, as well as the ability of anti-attack and anti-explosion, which makes insensitive high-energy materials become one of the research hotspots in the field of energetic materials ,2. The tIn recent years, nano-graphene-based energetic materials, as a new type of composite energetic materials such as desensitizer ,4,5 and In this paper, in order to provide a reference for the application research of nano-graphene-based energetic compounds, the preparation, desensitization, thermal decomposition and combustion properties of nano-graphene-based energetic compounds were reviewed.The preparation of nano-graphene-based energetic compounds is the basis of the research of this compound. Researchers have carried out a lot of research on the preparation of nano-graphene-based energetic compounds.At present, there are various graphene-based materials, and different uses have different requirements for graphene. The typical materials mainly include graphene-based ammonium nitrate compound, graphene-based metallic compound , graphen2/g, and a large number of ammonium perchlorate particles (average particle size 69.4 nm) were attached to the graphene skeleton. As the main component of high-energy composite propellant, Ammonium perchlorate (AP) also needs to be further improved in order to make it safer. Wang  et al. p2O3/ammonium perchlorate nanostructured energetic material by sol–gel method and supercritical carbon dioxide drying technology based on ammonium perchlorate/graphene nanocomposites. The experimental results showed that Fe2O3 and ammonium perchlorate were evenly dispersed in the nano-graphene aerogel layer. The porosity (SSA) of graphene and graphene/Fe2O3/ammonium perchlorate nanocomposites are 717 m2 g−1 and 123 m2 g−1, respectively. The total pore volumes (Vtot) of graphene and graphene/Fe2O3/ammonium perchlorate were 3.37 cm2 g−1 and 0.46 cm2 g−1, respectively.Lan et al.  preparedYe et al.  developeThe particle size of composites prepared by this method is generally about 7–8 microns. However, the energetic material may generate local hot spots during the ball milling process. 2Cl2 (in which graphene is insoluble) was added to the mixture. After filtration, washing and drying at 40 °C, the HMX/graphene complex was obtained. The specific operation process is shown in In a typical preparation process, HMX is dissolved in dimethyl sulfoxide at 40 °C and then graphene (about 2%) is added. Graphene was completely dispersed in a dimethyl sulfoxide solution of HMX by ultrasound, and CH2O3 particles on functionalized graphene sheets (FGS). The self-assembly process and the formation of chemical bonds are shown in Thiruvengadathan et al.  independ3)2 in an aqueous solution to obtain graphene-Cu (II) complex, and if the reaction temperature is controlled above 60 °C, the yield will be higher.Gozin et al.  used 5,5According to the explosive hot spot theory, the process of explosive reaction causing an explosion is divided into three steps. Firstly, the hot spot is generated under the action of an external stimulus. Then the hot spot as the core causes the reaction to diffuse to the surrounding explosives, and gradually changes to low-speed combustion. After that, the low-speed combustion slowly grows to stable detonation and further produces an explosion. It can be seen that explosive explosion must meet two conditions, hot spot generation and propagation. As long as the two conditions of explosive explosion can be inhibited, that is, reduce the occurrence of a hot spot or cut off its transmission path. In this situation, explosives can be insensitive and prevent the further occurrence of explosions.With the development of carbon nanomaterials, fullerenes, carbon nanotubes, nanocrystalline diamond and graphene have been used to reduce the sensitivity of explosives. Compared with fullerenes, carbon nanotubes and nano-diamonds, the application advantages of graphene oxide-based materials in the desensitization of energetic materials are more obvious. There are abundant oxygen-containing functional groups such as hydroxyl group, carboxyl group, epoxy group and carbonyl group on the surface and edge of graphene, which weakens the van der Waals force between graphene layers and makes it easy to slide between the layers, thus reducing the probability of hot spots. In addition, graphene has similar properties to polymers, gels and films, with high flexibility. Therefore, when the energetic material is stimulated by external stimuli, graphene can act as a buffer to prevent the formation and development of hot spots.Li Rui et al.  preparedHu Fei et al.  selected50) of CL-20 is about 17.3 cm, while the characteristic drop height of composite materials containing 5% GO has increased to more than 150 cm [50 was increased from 25.1 cm to 32.5 cm, the friction sensitivity is reduced from 100% to 72%. Song Xiaomin [Baoyun Ye et al.  peeled gn 150 cm . Jin Zhen 150 cm  used the Xiaomin  proposedThermal decomposition and combustion behavior are important characteristics of energetic materials when the materials are used in the propellant. The theoretical calculation, thermal decomposition and combustion behavior are reviewed as follows.Since ReaxFF (a commonly used molecular dynamics simulation method) was used to simulate molecular dynamics (MD) ,36,37,382O, CO2 and N2. The initial decomposition process is shown in The molecular dynamics method was used to study the improvement of the combustion rate of nitromethane by functionalized graphene sheets . The res−1, indicating that the hydroxyl groups on the GO surface were easily detached.In order to evaluate the effect of GO on the thermal decomposition of 4,4′-azo-1,2, 4-triazole. Fu Xiaolong et al.  studied 2 and H2O at temperatures lower than 2500 K, and the C=O bond at the edge of GO breaks at 3000 K to form CO2 and CO. During the decomposition process, small sheets of GO tend to aggregate into large carbon clusters. The main decomposition products of triaminoguanidine are NH3, N2 and H2. The decomposition process of GO triaminoguanidine is similar to go, forming carbon clusters. The decomposition products are H2O, NH3, N2 and H2. During the decomposition process of triaminoguanidine, HN2, H2N and H radicals are generated. The initial decomposition activation energy of triaminoguanidine was 94.0 kJ∙mol−1, and that of triaminoguanidine in GO triaminoguanidine was 78.6 kJ∙mol−1. In other words, GO reduced the activation energy of triaminoguanidine by 15.4 kJ∙mol−1. By analyzing the initial decomposition process of triaminoguanidine and GO triaminoguanidine, it was found that the initial decomposition of triaminoguanidine was mainly due to intramolecular hydrogen transfer. The catalytic effect of GO on the initial decomposition of triaminoguanidine was mainly reflected in the carbon atoms at the edge of GO, which promoted the decomposition of triaminoguanidine molecules. Zhang Chongmin  calculatGraphene has good combustion properties. At the same time, graphene can be evenly dispersed in water and organic solvents, which is conducive to full recombination with energetic materials. Therefore, graphene has a significant advantage in accelerating the reaction rate and energy release of energetic materials compared to other carbon materials. First of all, graphene has good electrical and thermal conductivity, which can effectively catalyze the thermal decomposition of energetic materials. Secondly, the energetic material forms nano-sized particles in the porous structure, which promotes the mass and heat transfer process of the material and greatly improves the energy release rate of the system. Thirdly, graphene, as a carbon material, is able to react with oxidants to contribute more heat without creating residual particles.4− to NH4+, and the speed control step of the high-temperature decomposition is transferred from O2 to the superoxide O2−), which can improve the rate of reaction rate [Wang  studied ion rate .2 technology and then immersed RDX in graphene aerogel solution to prepare graphene aerogel/RDX nano-energy-containing composites. Due to the unique nano-porous structure of graphene aerogel, the growth of RDX is limited, which makes the nanoscale RDX evenly dispersed into the graphene aerogel. Graphene aerogels can significantly accelerate the decomposition of RDX, reduce the thermal decomposition temperature and accelerate the decomposition rate, which contributes to the full reaction of RDX.LAN Yuanfei et al.  preparedZhang et al.  used the2O3 composites by hydrothermal and solvothermal methods. Reduced graphene/Fe2O3 had a significant promoting effect on the thermal decomposition of 5,5′-ditetrazole-1,1′-dioxy-dihydroxylammonium (TKX-50), reducing the low-temperature decomposition peak temperature of TKX-50 and increasing the apparent decomposition heat. This is because nano Fe2O3 particles are loaded on graphene, and the dispersibility is significantly improved, which can provide more active sites during the catalytic process and promote the decomposition of TKX-50.Zhao Fengqi et al.  prepared2 generated by NC self-decomposition, and the addition of nitrographene could provide NO2 for the reaction, thus increasing the reaction rate and the apparent heat of decomposition greatly.Yuan Shen et al.  studied 4− to NH4+. 2O4 composite.Zu et al.  a composIn order to investigate the effect of graphene on the reaction mechanism of energetic materials, Liu Yingzhe et al.  establisThe application of graphene-based compounds in solid propellants is one of the most concerning issues for researchers. The effect of graphene-based compounds on propellant combustion is the key factor for their application ,50. At pNasir K. Memon  in Purdu2 nanoparticle-based composition compared to the base composition, whereas a significant increase of 50% is achieved in the presence of the GTNC. Hence, the performance is improved significantly for the solid rocket propellant. The specific experimental results of the propellant are shown in Abhijit Dey in Deemed University  synthesi2O3) decorated graphene (GINC) hybrid materials, and further extend this application as a burn rate enhancer in the composite propellant. 2O3 (30% increases) to nano Fe2O3 (37% increase). In the presence of GINC, a significant increase (52%) in burn rate is achieved. In GINC, 20 effective iron content is about 50% as compared to nano and micron size Fe2O3. Hence GINC was found to be an excellent burn rate modifier for advanced AP-based propellant systems. (CP-1: Binder (15%) + Al(17%) + AP(68%) + Burn rate enhancer(Fe2O3)-Nil, CP-2: Binder (15%) + Al(17%) + AP(68%) + Burn rate enhancer(GINC)-1 wt.% over the batch, CP-3: Binder (15%) + Al(17%) + AP(68%) + Burn rate enhancer(nano Fe2O3)-1 wt.% over the batch, CP-4: Binder (15%) + Al(17%) + AP(68%) + Burn rate enhancer(Micron size Fe2O3)-1 wt.% over the batch). The burning rates of the four propellants are shown in Abhijit Dey in Deemed University  also synS. Isert  in PurduIn this paper, we also summarized some commonly used characterization methods of graphene-based energetic compounds in (1)The research on the reaction mechanism and structure design of the preparation of nano-graphene-based energetic compounds is still unclear.(2)The sensitization mechanism of nano-graphene on energetic compounds is still unclear.(3)The engineering application of nano-graphene-based energetic compounds still needs long-term exploration.Nano-graphene-based energetic compounds are a kind of multifunctional component of propellants and explosives with excellent comprehensive properties. At present, researchers have carried out a large number of studies on nano-graphene-based energetic compounds, but the research on nano-graphene-based energetic compounds still has the following problems:In conclusion, the molecular structure of nano-graphene-based energetic compounds is complex and elucidating the relationship between their structure and thermal stability will help to further understand the main effects and mechanisms of graphene-based compounds in propellants. Therefore, the research on the hot point inhibition principle, thermal decomposition characteristics and thermal decomposition mechanism of nano-graphene-based energetic compounds are of great practical significance in guiding the design, preparation and application evaluation of new graphene functional materials.


Hale studies the role of the microbiome in disease susceptibility in animal and human health. In this mSphere of Influence article, she reflects on how the papers “Evolution of mammals and their gut microbes” (R. E. Ley, M. Hamady, C. Lozupone, P. J. Turnbaugh, et al., Science 320:1647–1651, 2008,  What are the ultimate and proximate drivers of host-associated microbial community structure and change? Work across disciplines from medicine to agriculture to anthropology actively seeks to answer this question in part by determining how these communities can be manipulated to promote health and prevent or treat disease. Two papers that set the stage for current work and profoundly shaped my own thinking include Ley et al. 2008), “Evolution of mammals and their gut microbes,” and Desai et al. 2016), “A dietary fiber-deprived gut microbiota degrades the colonic mucus barrier and enhances pathogen susceptibility”  compared the gut microbial communities of 60 animal species, including humans, and evaluated the influence of diet, host taxonomic order, and sample provenance on gut microbial composition and diversity across host species. The authors hypothesized that gut microbiota play a critical role in the acquisition of new dietary niches, which can ultimately lead to speciation. They identified similarities in microbial communities based on host diet and phylogeny, and they made several unexpected observations: foregut and hindgut fermenting herbivores had similar diets but distinct microbial communities; herbivorous pandas, with simple guts, had microbial communities similar to other simple-gutted carnivores despite their dietary differences; and humans had microbial communities similar to other omnivorous species. This work provided a foundation for future studies on the gut microbiome and evolution/coevolution, diet, fiber consumption, and host physiology , 4, and g others , 6, reveThe question at the core of my research is: how do host-associated microbial communities shape disease susceptibility in animals? I study animal models of diseases including clostridial enteritis and bladder cancer that have translational relevance to human health. From a 30,000-foot view, this requires me to consider how similarities or differences in host taxa broadly impact microbial community structure, host-microbe relationships, and disease risks between species. At a finer scale, I evaluate how microbes interact within communities and hosts, and in response to external factors like diet or xenobiotics. Both the Ley and Desai papers expanded my scientific horizons by revealing how we could study microbial communities from ultimate and proximate perspectives. The Ley et al. paper applied recently developed tools (UniFrac) for comparing microbial communities , 8, whil


Thin spin-coated polymer films of amphiphilic copolymer obtained by partial acetalization of poly  are used as humidity-sensitive media. They are deposited on polymer substrate (PET) in order to obtain a flexible humidity sensor. Pre-metallization of substrate is implemented for increasing the optical contrast of the sensor, thus improving the sensitivity. The morphology of the sensors is studied by surface profiling, while the transparency of the sensor is controlled by transmittance measurements. The sensing behavior is evaluated through monitoring of transmittance values at different levels of relative humidity gradually changing in the range 5–95% and the influence of up to 1000 bending deformations is estimated by determining the hysteresis and sensitivity of the flexible sensor after each set of deformations. The successful development of a flexible sensor for optical monitoring of humidity in a wide humidity range is demonstrated and discussed. Transparent and flexible sensing devices are of great interest because of their unique superior characteristics such as conformity, endurance and light weight. Sensors that can display induced color response, exhibit major flexibility and have a contactless method of detection are increasingly desired and studied mostly for monitoring ambient conditions and human health. Their reversibility and stability open the possibility for applications in human activity/health detection via optical humidity sensors. In general, depending on the sensing principle of the humidity sensor, there are different types of devices—capacitive, resistive, surface acoustic wave, those based on a change of color (colorimetric), etc. Among them, optical sensing, which detects alterations in environmental humidity via a color change, are particularly interesting due to the fact that it is not necessary for a specially trained specialist to use it, and its working principle presupposes an intuitive detection method ,2. MoreoDiverse materials have been extensively studied in order to develop such low-cost humidity sensors with high performance and sensitivity, stability, a broad dynamic range and short response time. However, it is not easy to meet these requirements and the development of that kind of sensor faces multiple challenges such as finding compatible materials, suitable substrates and proper manufacturing techniques. A variety of materials can be used for deposition on flexible substrates ,4,5,6 buco-vinyl acetal) (PVA-Ac) thin films with acetal content in the range of 18–28% are suitable for humidity sensing. The optimization of the chemical composition has revealed that thin films of PVA-Ac with 24% acetal content annealed at 60 °C exhibit the best performance. Further, various flexible substrates, including PET, PLA and composite polysiloxane ®Compo-SiL, were employed to fabricate flexible devices for humidity detection :[PVA] = 1:4. The reaction was left to proceed under vigorous stirring at 30 °C for four hours. The product obtained was isolated from the reaction mixture by increasing the temperature to 60 °C, which led to copolymer precipitation due to its lower critical solution temperature (LCST) behavior. Copolymer was further purified by dissolution in deionized water at room temperature followed by precipitation at 60 °C, and finally dried in vacuum.Amphiphilic PVA-Ac copolymer with 24% acetal content was synthesized by hydrophobic modification of PVA  with acetaldehyde  as already described in ,45. Brie6 as solvent. The content of acetal groups was estimated to be 24% from the 1H NMR spectrum of the copolymer .Copolymer solutions of concentration 1 wt. % in mixed water–methanol solvent in a volume ratio of 20:80 were prepared and used for thin film deposition on PET substrates. Prior to the deposition, PET substrates were covered with a gold/palladium layer (Au/Pd ratio of 80:20 and thickness of 30 nm) through cathode sputtering for 60 s under vacuum 4 × 10A spin-coating method was used to deposit thin polymer films on a flexible substrate. An amount of 0.250 mL of the solution was dropped on PET substrate and then spun stepwise. In the first step, the substrate was rotated for 1.5 s at 2500 rpm, and then in the second stage the rotations and duration were increased to 4000 rpm and 60 s, respectively. In both steps, the acceleration speed was 2500 rpm/s. Post-annealing of the samples was performed in air for 30 min at 60 °C. The schematic sequence of the film deposition method of the individual elements of the sensor is shown in The surface morphology of the films was characterized by a Philips 515 scanning electron microscope.Reflectance spectra of the films deposited on Si substrate were measured with a UV–Vis–NIR spectrophotometer . In order to calculate refractive index (n), extinction coefficient (k) and thickness (d) of the films, nonlinear curve-fitting algorithms were used for minimization of the discrepancies between measured and calculated reflectance spectra .The bending test was performed by a computerized homemade bending setup, with ESP301 control platform. During the bending test, the flexible substrate was fixed between two clamps horizontally and then was bent by pushing the two clamps together up to a bending radius of 4.37 mm. After each set of bends, the surface roughness and the optical quality of the deposited films were examined with a 3D optical profiler .maxT = |T95RH–T5RH|. The percentage of hysteresis (H) was calculated from the following equation:upT and downT are transmittance values measured when humidity increases and decreases, respectively; ∆maxT is the maximum transmittance change in the studied humidity range (RH2-RH1) and ∆hystRH is the humidity range where hysteresis is observed. The sensitivity of the sensor S was calculated according to the following equation:T is the change in the film’s transmittance in % for humidity variation from RH1 to RH2.All humidity experiments were conducted by using a homemade bubbler system that generates vapors from liquids and samples were placed in a cell with a reference humidity sensor integrated into it . SensingRH) of detection depends on the sensitivity and measurement accuracy in the signal and was calculated as:errT = 0.1% is the experimental error (accuracy) of T and S is the sensitivity, calculated by Equation (2). Accuracy and sensitivity are calculated for two different humidity ranges: 5–75% and 75–95%.The accuracy/resolution , optical images of the surface of the PET/polymer sensor were taken using an optical profiler. The effect of bending on surface morphology was established after each set of bending deformations . Figure It is clearly seen that after 1000 bending deformations, the surface of the sample is still smooth and free from cracks and defects. Based on the pictures in All humidity sensing experiments were conducted by using a homemade bubbler system that generates vapors from liquids. The tested samples were placed in a cell with a reference humidity sensor integrated into it. The first transmittance measurement was performed in air. Then, dry argon was purged in the cell. As a result, the relative humidity in the cell gradually changed from the RH of the air usually 45–55% RH) to 5% RH  and the transmittance spectrum at low humidity was measured . In the –55% RH tT, accuracy/resolution ΔRH and sensitivity S of the sensor before and after all sets of bending deformations. In order to continue the detailed study of the impact of bending on the humidity-sensing ability of the samples, transmittance values (T) were monitored as a function of relative humidity (RH) that gradually changed in the range from 5 to 95% RH. The plots of T versus RH were further used to evaluate the hysteresis values H, transmittance changes ∆maxT = T95% − T5%  with acetal content of 24% and a thickness of 80 nm. The metallization of PET substrate provides sufficient optical contrast between the humidity-sensitive film and PET substrate while the small thickness assures a fast response. A small increase of 1.5% of transmittance of the sensor is obtained after 1000 bending deformations, mostly due to the fine network of cracks appearing in the metal film as a result of bending. However, it is demonstrated that the influence of up to 1000 bending deformations on the surface morphology and optical quality of the sensor is negligible. Moreover, an enhancement of sensitivity of more than 40% is observed after bending for relative humidity higher than 75%, resulting in an improvement in resolution from 0.6% RH to 0.4% RH. It is assumed that the weakening of adhesion due to bending is the most probable reason, thus facilitating polymer swelling. The results obtained open up new opportunities for the use of PET/Au:Pd/polymer structures as in situ optical flexible sensors for humidity detection.The development of a flexible and transparent polymer-based optical humidity sensor is demonstrated. The sensor consists of pre-metallized PET substrate covered with a spin-coated thin film of poly(vinyl alcohol-


Due to its unique electronic and optical properties, graphene has been used to design tunable optical absorbers. In this paper, we propose a plasmonic absorber consisting of non-concentric graphene nanodisk arrays, which is designed to operate in the mid-infrared spectral range and is capable of achieving nearly perfect absorption. Two perfect absorption peaks are produced due to the impedance of the structure, which matches that of the free space. The influences of the thicknesses of the dielectric layer, the size of graphene nanodisk, and the incident conditions on the absorption are studied. Moreover, the absorption intensity can be independently tuned by varying the Fermi levels of two graphene nanodisks. Furthermore, the polarization-independent absorbance of the absorber exceeds 95% under oblique incidence, and remains very high over a wide angle. This proposed absorber has potential applications in optical detectors, tunable sensors, and band-pass filters. Perfect absorbers have a lot of important applications in the domain of photodetectors, filters, etc. ,2. PlasmA variety of graphene absorbers, such as ribbons, disks, and rings, have been investigated. For example, Meng et al. reported a periodically cross-shaped graphene ribbon array, where two absorber peak wavelengths can be simultaneously adjusted by tuning the Fermi energy of the graphene . Li et aHerein, a simple graphene-based plasmonic absorber has been designed. The absorber consists of a gold mirror, dielectric layers, and dual-layer non-concentric graphene nanodisks. Through accurate simulations, we demonstrate two perfect absorption peaks due to the impedance of the structure matching that of the free space. The two absorption peaks originate from dipole resonances by the upper and lower nanodisks through the analysis of the electric field diagram, and can be independently controlled by varying the Fermi level and geometrical factor of the corresponding graphene layer. We further show that the absorber has the characteristic of polarization-insensitive absorption and maintains a high absorption over a wide range of incidence angles. This proposed absorber has potential applications in optical detectors, tunable sensors, and band-pass filters.1 = 150 nm and D2 = 180 nm are placed on the top surface of two dielectric layers with thicknesses of H1 = 60 nm and H2 = 1.5 μm, respectively. The periodicity P of the structure is 400 nm.The two dielectric layers are regarded as lossless, and the permittivity is 1.96 . The per1014 s−1 . The con1014 s−1 ,21,22 based on the finite element method . The absmpedance .A = 10.4 μm and λB = 13.6 μm. It can be seen the whole absorption spectra arises from the spectral superposition of the upper and lower graphene nanodisks, evidenced by the dashed line overlapping completely with the solid line. The physics of the structural perfect absorption can be understood by analyzing the normalized surface impedance [The absorption spectra of the graphene structure with the non-concentric bilayer are shown in mpedance :(3) Z=, as follows:In addition, the influence of the geometric parameters of the proposed absorber is analyzed carefully. tionship ,29(4)ℏωEvidently, the resonant wavelength has a positive correlation with the diameter of the graphene disk. Therefore, absorption peaks A and B will red-shift with the increase of the diameter of the corresponding graphene nanolayers, which is in good agreement with the simulation in 1 from 50 nm to 70 nm. The main reason for this is that the thickness of dielectric H1 is far less than the operation wavelength of the structure, and the Fabry–Pérot effect related to the top dielectric layer can be effectively prevented.As seen from 2 [L1 is increased as the ratio of the inner diameter to outer diameter of the ring decreases [L1 increases, thus absorption peak B blue-shifts.2 . Accordiecreases . AccordiF1. Peak A experiences a blue-shift from 11.04 μm to 9.83 μm as the Fermi level EF1 varies from 0.47 eV to 0.59 eV, while peak B remains unchanged. F2. Contrary to F2 from 0.44 eV to 0.56 eV, whereas peak A remains constant. The absorption peaks shift to blue with the increase in the Fermi levels of the corresponding graphene nanodisk, which can be explained as follows: The shift of resonance frequency is determined by the imaginary part of graphene conductivity. When the Fermi level increases, the imaginary part of graphene conductivity increases [F1 = 0.56 eV and EF2 = 0.53 eV, respectively, where the impedance of the absorber is perfectly matched with the impedance of the free space [It is known that the absorption peaks of the designed absorber can be independently tuned by varying the Fermi level of the corresponding graphene layer. ncreases , resultiee space . CompareThe case of different polarized light incident obliquely is discussed in A simple structure for an independently tunable dual-band perfect infrared absorber based on non-concentric graphene nanodisk has been demonstrated. The two absorption peaks originate from the dipole resonance mode formed by the corresponding graphene nanodisk. Moreover, the near-unity absorption is because the impedance of the structure matches the impedance of the free space at the wavelength corresponding to the absorption peak. We analyzed the influence of the structural parameters on the absorption spectra. It is shown that the absorption strength can be independently tuned by varying the Fermi levels of graphene in the corresponding nanodisks. Furthermore, two perfect absorption peaks can be obtained over a wide incident angle span, and are insensitive to the incident angle for TE and TM polarizations. This proposed infrared absorber has potential applications in optical detectors, tunable sensors, and band-pass filters.


The human microbiome is a complex community of microorganisms, their enzymes, and the molecules they produce or modify. Recent studies show that imbalances in human microbial ecosystems can cause disease. Our microbiome affects our health through the products of biochemical reactions catalyzed by microbial enzymes . Despite their significance, currently, there are no systematic strategies for identifying these chemical reactions, their substrates and molecular products, and their effects on health and disease. We present TransDiscovery, a computational algorithm that integrates molecular networks (connecting related molecules with similar mass spectra), association networks (connecting co-occurring molecules and microbes) and knowledge bases of microbial enzymes to discover microbial biotransformations, their substrates, and their products. After searching the metabolomics and metagenomics data from the American Gut Project and the Global Foodomic Project, TranDiscovery identified 17 potentially novel biotransformations from the human gut microbiome, along with the corresponding microbial species, substrates, and products. The human microbiome consists of over 22 million genes , many ofThe products of microbial biotransformations could be both health-promoting and detrimental . Health-Functional profiling approaches are widely used for annotating the function of microbial enzymes ,14. HoweRecent advances in metagenomics have enabled the collection of sequencing data on tens of thousands of human microbial communities as part of the Human Microbiome Project ,21 and tIn the past, association network methods have been introduced for discovering biotransformations by detecting the cooccurrence of molecular and microbial features across various microbial communities ,27,28. IWhile association networks have revealed several known and novel microbial natural products and biotransformations, these methods suffer from a common shortcoming that makes their application limited: All correlation-based methods report many strong correlations that do not correspond to any biological interactions, e.g., two features affected by a confounding feature could be correlated without any interaction. Therefore, association networks are dense networks with many spurious edges. These spurious edges require researchers to perform extensive computational searches to identify the true biological interactions from the network.In this paper, we develop a culture-independent approach for assigning functions to microbial biotransformation enzymes and specifying their substrates and products based on large metagenomics and tandem mass spectral datasets. We introduce TransDiscovery, a computational framework that integrates molecular networks with association networks and knowledge bases of enzymatic transformations  to systBy applying TransDiscovery to the molecular and microbial features in the AGP and Global Foodomics Project (GFoP) datasets, we discovered 17 unique biotransformations of known substrates from PhenolDB , along wOverview of TransDiscovery. The TransDiscovery pipeline  with m/z 287.11 that was unique to the AGP dataset. Dereplicator+ [p-value threshold of Sutterella wadsworthensis strain SW4. Further genome annotations revealed that this strain had a gene cluster with ribonucleoside hydrolase and ribokinase, which are known to play a role in the degradation of riboflavin in Microbacterium maritypicum [Devosia riboflavina [Sutterella is quite different from those of Microbacterium and Devosia, and its molecular product is also slightly different , suggesting that this riboflavin degradation pathway might be novel.licator+  identifilicator+ . TransDiitypicum  and Devooflavina . The genDecarboxylation of hydroxycinnamic acids byEnterobacteria. The association networks revealed a strong negative correlation between various Enterobacteria species and p-coumaric acid (m/z 165.054), ferulic acid (m/z 175.064), and caffeic acid (m/z 181.094). The same Enterobacteria species showed strong positive correlations with molecular features with m/z 121.065, 137.060, and 151.074. These features matched the masses of p-coumaric, caffeic, and ferulic acid after the loss of COEnterobacteria has been previously reported in the literature [m/z 121.065, 137.060, and 151.074 with phenolic acid decarboxylase (K13727), an enzyme frequently observed in Enterobacteria, Lactobacillus, and Actinomyces.terature . AssociaDihydroxylation of hydroxybenzoic acid byBlautia. In the association network results, a strong negative association between hydroxybenzoic acid (m/z 139.039) and Blautia and a strong positive association between molecular features with m/z 123.044 and Blautia were identified. The mass for this molecular feature matched the loss of an oxygen atom (15.99 Da). It has been previously reported that hydroxybenzoic acid undergoes a dihydroxylation reaction with 4-hydroxybenzyl CoA reductase from the Blautia species [ species ,42.In this paper, we introduce TransDiscovery, a powerful method for systematically identifying microbial biotransformations by combining a molecular network, association network, and knowledge bases of microbial enzymes. Experimental advances in high-throughput sequencing and mass spectrometry technologies have enabled the collection of genomic and tandem mass spectrometry data from tens of thousands of human microbial communities. Tens of thousands of microbial features  and molecular features (molecular substrates and products) from these communities, coupled with increasingly accessible knowledge bases of microbial enzymes, provide great opportunities to dissect the complex biotransformations from the human microbiome. By applying TransDiscovery to the existing database, 17 biotransformations were identified. While some of the biotransformations were validated by a literature search, others are potentially novel biotransformations for further experiments.The Human Microbiome Project (HMP) has provided a comprehensive catalog of microbial genes in human microbiota. While this catalog is a gold mine for future studies of human health and disease, in order to fully utilize the promise of the HMP, we need to have a better understanding of the mechanisms of action for these genes and how they affect the human host.Currently, there are no high-throughput technologies for revealing the activity of microbial enzymes, their substrates’ specificity, their molecular products, and their roles in health and disease. Tandem mass spectrometry is a promising technology for high-throughput identification of the substrates and products of microbial biotransformations. However, in contrast to the computational techniques available for high-throughput analysis of metagenomics data of the microbiome, well-established methods for tandem mass spectrometry data analysis are not available.In the past, association studies have been applied for the detection of molecular products of microbial biotransformations. However, these techniques report many spurious pairs, as they are based on correlation, rather than causation. TransDiscovery improves association networks by integrating them with molecular networks and biotransformation knowledge bases to reliably discover microbial biotransformations.After searching metagenomics and metabolomics data from the American Gut Project and Global Foodomics Project, TransDiscovery reported 17 potential biotransformations. Several of these biotransformations were validated by a literature search. Currently, there is no comprehensive database of microbial biotransformations. By searching against the most extensive databases, such as HMDB  and MetaDiscovery of novel biotransformations is a computationally laborious task, and usually, each paper in this area reports a single novel biotransformation. TransDiscovery enables the discovery of numerous biotransformations in a single study. Validation of the biotransformations predicted by TransDiscovery requires culturing of the predicted microbial strains in media containing the substrate and screening for the presence of the product molecule over time. Validation of the predicted gene clusters further requires knock-out experiments. Wet-lab validation can become a path to the confirmation of the results of TransDiscovery.While so far, we mainly focused on reporting novel biotransformations identified by combining the AGP and GFoP datasets with PhenolDB, TransDiscovery can take any knowledge base of interest as input. Compared to PhneolDB, other knowledge bases, such as HMDB and FooDB, hold hundreds of times more chemical structures of small molecules from the human body. In the analysis between the AGP and GFoP datasets and HMDB, we were able to obtain hundreds of candidate biotransformations with an even more stringent One of the limitations of reliance on marker gene data (16S) for the annotation of microbial features is that it makes it difficult to conduct accurate functional profiling analyses. Currently, TransDiscovery supports the incorporation of shotgun metagenomics data, which enable higher-resolution functional annotation. With shotgun metagenomics data, the identified biotransformations can be linked to the specific enzymes. This will not only help further screen valid biotransformations, but can also provide insight for interpretation and follow-up experiments. However, shotgun metagenomics are more expensive, and currently, there are only a limited number of public samples (a few hundred) with paired shotgun metagenomics and tandem mass spectrometry data. Therefore, it has been impossible to detect any highly significant associations based on shotgun metagenomics data.Another limitation of the existing approaches is that, while extensive genomics data are available from reference microbial isolates, currently, reference metabolomics datasets from microbial isolates are not available. Reference genomics data have made it possible to map a large number of microbial features to their corresponding taxonomies, but currently, the majority of molecular features of the microbiome remain orphans, as it remains unclear whether they are produced by the host or the microbial strains. While TransDiscovery is a step forward toward annotation of the microbiome metabolites in complex datasets, the availability and incorporation of metabolomics data from reference microbial isolates can vastly increase the power of such computational approaches.In conclusion, TransDiscovery provides a culture-free approach for assigning functions to microbial enzymes from complex microbial communities that does not require isolation of the microbes and purification of the enzymes. Applications of this strategy include high-throughput characterization of the biotransformation products of dietary molecules by enzymes from the human microbiota. We believe that with the rapid growth of mass spectrometry/metagenomics datasets and knowledge bases, TransDiscovery can become a crucial tool for better understanding gut microbial mechanisms.Datasets. The AGP dataset [ dataset  contains dataset ,46 conta dataset  was used dataset  was used dataset . The pre dataset . The Phe dataset  is a pub dataset  is a pubLiquid chromatography mass spectrometry. The AGP dataset was collected on an UltiMate 3000 UHPLC system equipped with a reverse-phase C18 column coupled to a Bruker Impact HD quadrupole time-of-flight (qTOF) mass spectrometer [trometer . The GFotrometer .Molecular feature extraction. Molecular features of the LC-MS/MS data were extracted using Optimus [x in sample s. Features present in less than two samples were discarded. Optimus . The resMicrobial feature extraction. Microbial features with taxonomy annotations used in the main analysis were extracted from the 16S rRNA data using QIIME [y in sample s. The strain annotation listed in z in sample s. Enzymatic features from shotgun sequencing data were identified using KofamKOALA [Shotgun-EnzymeMatrix, where Shotgun-EnzymeMatrix represents the presence or absence of KEGG enzyme e in sample s. OTUMatrix, EnzymeMatrix, and Shotgun-EnzymeMatrix were correlated with the molecular features.ng QIIME . The resfamKOALA . This reAssociation network construction. An association network was constructed by calculating a pairwise association test between molecular features and microbial features [x and microbial feature y, the null hypothesis assumed that “the abundance of molecular feature x in samples” and “the count of microbial feature y in samples” were independent. If the probability of null hypothesis features . The staMolecular network construction. A molecular network was constructed using the global natural-product social molecular networking (GNPS) infrastructure [tructure . First, tructure , and idetructure . Edges iIdentifying candidate biotransformations. In the molecular network, if two spectra (nodes) were very similar (high cosine similarity score), they were connected with an edge. Generally, spectral similarity implies structural similarity [milarity . Under tSubstrate identification. The substrate molecular features were identified by searching them against a chemical structure database  using DPhenolDB . PrecursProduct identification. For each identified substrate molecule, we used BioTransformer [nsformer  to ident