At the same time, electrical resistivity of microcapsules/bitumen samples had a decrease with more graphene in bitumen.Self-healing bituminous material has been a hot research topic in self-healing materials, and this smart self-healing approach is a promising a revolution in pavement material technology. Bitumen has a self-healing naturality relating to temperature, healing time, and aging degree. To date, heat induction and microencapsulation rejuvenator are two feasible approaches, which have been put into real applications. However, both methods have disadvantages limiting their practical results and efficiency. It will be an ideal method combining the advantages and avoiding the disadvantages of the above two methods at the same time. The aim of this work was to synthesize and characterize electrothermal self-healing microcapsules containing bituminous rejuvenator with graphene/organic nanohybrid structure shells. The microcapsules owned electric conductivity capability because of the advent of graphene, and realized the self-healing through the two approaches of heat induction and rejuvenation. The microcapsule shells were fabricated using a strength hexamethoxymethylmelamine (HMMM) resin and graphene by two-step hybrid polymerization. Experimental tests were carried out to character the morphology, integrity, and shell structure. It was found that the electric charge balance determined the graphene/HMMM microstructure. The graphene content in shells could not be greatly increased under an electrostatic balance in emulsion. X-ray photoelectron spectroscopy (XPS), Energy dispersive spectrometer (EDS), Transmission electron microscope (TEM) and Atomic force microscopy (AFM) results indicated that the graphene had deposited on shells. TGA/DTG tests implied that the thermal decomposition temperature of microcapsules with graphene had increased to about 350 °C. The thermal conductivity of microcapsules had been sharply increased to about 8.0 W/m The function of self-healing is one of the most basic characteristics of nature ,2,3. SelIn recent years, self-healing concept was introduced into the field of engineering materials and construction materials, such as composites, biomaterials, concrete, and asphalt . It is wIn general, the self-healing capability of asphalt pavement can be promoted depending on the supplementary role of external materials. In order to obtain the above goal, these additives must survive and prevail in the harsh conditions during treatment process and service life in asphalt . To dateInspired by the above analysis, it will be an ideal method to combine the advantages of the above two methods. We can image that the microcapsules containing rejuvenator with electric conductivity capability will realize the self-healing through two approaches: heat induction and rejuvenation. The advent of graphene provides the possibility for the realization of this assumption. Graphene is the first two-dimensional (2D) atomic crystal exhibiting special properties, such as high stiffness, high electrical conductivity, high thermal conductivity, and high barrier property ,20. ThesFrom the first reported mention of self-healing composites in the literature, a conventional method was obtained and extensively investigated by mixing microcapsules containing healing agents or chemical materials in polymer materials . To dateThe aim of this work was to conduct a preliminary investigation of electrothermal self-healing bituminous composite material using microcapsules containing rejuvenator. These microcapsules were fabricated with a graphene/HMMM hybrid structure by a two-step self-assembly method with the help of macromolecules entanglement and electrostatic adsorption. HMMM carried more positive charges and graphene was negatively charged in an alkaline environment. Graphene was successfully introduced into the microcapsule shells, which greatly improved the electrical conductivity and thermal conductivity of the shells. Morphology, chemical structure, heat properties, and electric conductivity had been systemically investigated based on microcapsule samples with different components of graphene. In a microcapsules/bitumen composite system, the self-healing occurred when a low voltage was added to the material forming a closed loop to generate heat. The heat greatly enhanced the self-healing capability of materials.3, 4.24 Pa·s, Tianjin Sinogo. Co., Ltd., Tianjing, China). Prepolymer hexamethoxymethylmelamine (HMMM) was used as the polymeric shell material supplied by Tianjin Sinogo. Co., Ltd. . A copolymer of styrene maleic anhydride (SMA) was purchased as a dispersant . Bitumen was supplied by Qilu Petrochemical of China. A 40/50 (penetration grade) bitumen sample was artificially manufactured with a 80/100 (penetration grade) bitumen sample using a thin film oven process.Graphene was commercial product supplied by Tuling Co., Ltd. . Oily rejuvenator was used as the self-healing agent  to 20 °C g. It wastructure . MeanwhiThe state of the materials in emulsion was observed by a biological microscope . A SEM  was used to analyze the surface morphologies of dried microcapsules. The mean size of microcapsule samples were tested by a particle size distribution instrument . In order to measure the shell thickness, an ultramicrotomy was applied. About 10 g of microcapsules was blended with gelatin solution (30 wt %) forming a composite sample. The dried sample was carefully cut to obtain the cross-section slides by an ultramicrotome . The thickness values of various shells were measured under a microscope with an average value of fifty microcapsules. Fourier transform infrared spectra were used to analyze the chemical structures of microcapsule samples .The carbon structures of microcapsules were characterized by an X-ray photoelectron spectroscopy . The elements ratios  were measure using an energy dispersive spectrometer . Transmission electron microscope (TEM) was utilized to analyze the graphene state in shells . Atomic force microscopy  examination was carried out at room temperature using silicon cantilevers.−1 under a N2 protection [The thermal resistance characteristics of microcapsules were tested using thermogravimetric analysis  with a scanning rate of 5 °C·minotection .−1. The electric conductivity of the composite samples was tested using a four-point probe electrical resistivity instrument . The test method met the criterion of ASTM F84. The instrument had an accuracy of 0.01 μΩ∙mm.The electric conductivity of microcapsule powder was measured by a powder electrical resistivity instrument . The test method met the criterion of ISO 11713-2000. The instrument had an accuracy of 0.01 μΩ∙mm. The bitumen (40/50) was blended with various contents of microcapsules at 160 °C stirring with a speed of 300 r·minT1 and T2 are temperature values of two plates, A is the heat transition area, s is the thickness of sample, λ is the thermal conductivity, H is the heat flux.The thermal conductivity measurement was carried out by using an instrument  was used to test the thermal conductivity of samples according to measurement standard of ASTM E-1530. A sample was put between two polished aluminum (Al) plates holding with a constant compress stress. The Al plates were controlled at two different temperatures and the lower one was part of a transducer for calibrated heat flow. Because of the temperature differential, the heat flowed from one to another plate forming an axial temperature gradient. Temperature sensors monitored the temperature drop through the sample. The various temperatures of sample were recorded along with the output from the heat flow transducer after reaching a temperature equilibrium state. The thermal conductivity then was calculated by utilizing these temperature data and the sample thickness values. Thermal conductivity values are calculated by Equation (1),In this study, microcapsules were fabricated using HMMM prepolymer as the shell material through a two-step polymerization. In previous works, it had been found that both of melamine-formaldehyde (MF) resin and MMF resin were successfully applied to fabricate microcapsules with a compact shell structure ,41. Core−1. The weight ratio of core/shell was 1/1. In Based on previous works, a novel two-step polymerization method was applied in this study to prepare microcapsules with graphene. SMA was similarly selected as an emulsifier. −1. Six types of microcapsules are prepared with different graphene/shell weight percentage of 0%, 2%, 4%, 6%, 8% and 10%, which are noted as MG-0, MG-2, MG-4, MG-6, MG-8 and MG-10, respectively. With the same stirring rate, the microcapsule samples nearly have the same mean size values in a range of 22.4–25.4 μm. Moreover, the microcapsules have the shell thickness value between 2.5 μm and 2.7 μm without a large change. It has reported that the shell thickness is mainly determined by the core/shell weight ratio [3/polymer shells [3 particles were embedded into polymers to form a stable composite shell structure. Because of the same fabrication mechanism, it may be deduced that graphene has adhered to the core droplets with HMMM to form inorganic/organic composite shells.In order to measure the shell thickness, microcapsules were mixed in gelatin gel to form composite samples. The dried composites were cut to obtain the cross-section by an ultramicrotome. ht ratio . To simpht ratio . With thr shells . It was 3) groups. The further cross-linking reactions of the oligomer form the stable shells of microcapsules  of rejuvenator, self-healing microcapsules without graphene (MG-0) and self-healing microcapsules with 2% and 10% graphene (MG-2 and MG-10). The spectrum of rejuvenator (d1) exhibits the characteristic absorption bands at around 1461cm−1 and 2924 cm−1 attributed to –CH3 asymmetric bending vibration and alkyl −CH2 stretching vibration. The spectra of all self-healing microcapsules  exhibit three absorption bands at around 1653 cm−1 (C–C), 3115 cm−1 (N–H), and 3618 cm−1 (O–H). The characteristic peaks of the rejuvenator no longer exist, which indicates that the rejuvenator has been microencapsulated. The spectra (d3) and (d4) are microcapsules with different graphene contents in shells. It is found that both samples have O−H bonds, which may belong to the residual water. More graphene in shells does not change the chemical structure of HMMM/graphene composites. In other words, the graphene has a physical bond with cross-linked HMMM networks.XPS can be used to analyze the surface chemistry of a material in its as-received state. XPS is routinely applied to determine the types and the quantity of elements that are present within the top 1–12 nm of the sample surface. Chemical-state analysis is widely used for the element carbon. Chemical-state analysis of the surface of carbon-containing polymers readily reveals the presence or absence of the chemical states of carbon shown in bold, in approximate order of increasing binding energy. For example, the nominal binding energy of the C1s electron is 284.6 eV, subtle but reproducible shifts in the actual binding energy, the so-called chemical shift, provide the chemical state information. In order to further verify the existence of graphene in shells, XPS spectra were analyzed to give more details about the carbon element in microcapsule shells. The ability to produce chemical state information from the topmost few nm of any surface makes XPS a unique and valuable tool for understanding the chemistry of any surface. The local bonding environment of a material is affected by its formal oxidation state, the identity of its nearest-neighbor atom, its bonding hybridization to that nearest-neighbor atom, and in some cases even the bonding hybridization between the atom in question and the next-nearest-neighbor atom. 1–d1 show the EDS results of microcapsule samples  with different graphene in shells. Furthermore, the tables list the weight ratios and atom ratios of elements of C, N and O on the shell surfaces. It has been confirmed that the element measurement points were all on the shells of single microcapsule as the SEM morphologies shown in 2–d2. The presented elements  on the shell were measured. Firstly, it is obvious that the surface carbon contents of the self-healing microcapsules added with graphene are larger values identifying from the C peaks. The characteristic peaks of C indicate the existence of graphene in shells. Secondly, it is found that the weight ratio and atom ratio of N and O both have decreased with the increasing of graphene in shells. For example, the N weight ratios are 31.15%, 29.36%, 21.02% and 18.40% for MG-2, MG-4, MG-6 and MG-8, respectively. In the cross-linking structure of HMMM network, the atom ratio of N/C can be approximated as 1/1 as shown in EDS is an analytical technique used for the elemental analysis or chemical characterization of a material. It relies on an interaction of some source of X-ray excitation and a sample. Its characterization capabilities are due in large part to the fundamental principle that each element has a unique atomic structure allowing a unique set of peaks on its electromagnetic emission spectrum. Based on this main principle of spectroscopy, the number and energy of the X-rays emitted from a microcapsule can be measured by an energy-dispersive spectrometer. As the energies of the X-rays are characteristic of the difference in energy between the two shells and of the atomic structure of the emitting element, EDS allows the elemental composition of the microcapsules to be measured. Besides the determination of graphene deposition in shells, the microstructure of graphene/organic hybrid shells needs to be investigated. The knowledge is helpful to understand the relationship between the graphene states in shells and the physical properties of shells. For example, the thermal properties and mechanical properties of microcapsules may be greatly influenced by the graphene/organic hybrid structure shells. Comparing to MG-0, the beginning weight loss rate of MG-2 has obvious decreased as shown in Thermal conductivity is an important parameter reflecting the thermal transmission efficiency of materials. A higher thermal conductivity value means that a material has a relative faster heat absorbing or releasing capability during temperature changes. In Electrical resistivity is an intrinsic property that quantifies how strongly a given material opposes the flow of electric current. A high electrical resistivity value means a material that not allows the flow of electric current. Most of polymers have a high electrical resistivity, which are considered as insulators. Bituminous materials also are insulators without conductivity. It is crucial in this study that bitumen samples have certain conductivity, and they can convert electric energy into heat energy. A literature review shows that the conductivity of organic materials can be enhanced by the addition of graphene with several orders of magnitude ,46. For 13 Ω·m. Even mixing with microcapsules (1.51 × 1013 Ω·m), the bitumen/microcapsule composite sample still has an electrical resistivity value of 1.25 × 1013 Ω·m. As its components are polymeric materials, it still can be considered as a insulator without conductivity. −2 Ω∙m and MG-10 has the minimum value of 3.8 × 10−2 Ω·m. With the increasing of the weight content of graphene in shells, the microcapsule samples has a sharp decrease in electrical resistivity. Comparing to pure microcapsules without graphene, the microcapsules with graphene has reduced the electrical resistivity of about fifteen orders of magnitude. Pure graphene has a electrical resistivity value about 9.0 × 10−8 Ω·m [10−8 Ω·m . As a po(1)Morphology observations showed that the microcapsules with graphene had a global shape with a compact shell structure. The microcapsules with 2.0–6.0% graphene had a very smooth surface without attachment. The polymer molecules tangled with graphene during the polymerization, so the unconsumed polymer made the tangled graphene to be left in emulsion or only adhere incompactly on shells.(2)Chemical structure analysis confirmed that the HMMM prepolymer had a cross-linked chemical reaction in emulsion state to yield a compactable shell structure. Graphene did not change the chemical structure of HMMM/graphene composites, it only had a physical bond with cross-linked HMMM networks.(3)The results proved that the graphene had deposited on the microcapsules surface. The graphene addition had an optimal amount to balance both two actions of charge adsorption and chain entanglement. It was found that the microcapsules had an increasing trend of graphene contents on shells with the increasing of graphene addition during preparation process of microcapsules.(4)The graphene/HMMM composites structure enhanced the thermal stability of microcapsules. Moreover, the graphene had a good heat transfer performance and made the heat distribution in the microcapsules more uniform, thereby improving the thermal stability of microcapsules.(5)2·K with only 2.0 wt % graphene in shells. At the same time, electrical resistivity of microcapsules/bitumen samples had a decreased trend with more graphene in bitumen.The thermal conductivity of microcapsules sharply increased to about 8.0 W/mAn electrothermal self-healing method had been reported in this study by using microcapsules containing rejuvenator with graphene/organic hybrid structure shells. These microcapsules had been fabricated by a two-step self-assembly polymerization process. With the help of emulsified SMA molecules, prepolymer HMMM and graphene deposited on oily rejuvenator droplets forming compact shells. Electric charges were the driving force of the deposition. These microcapsules combined the advantages and avoiding the disadvantages of the heat induction and rejuvenator self-healing for asphalt material. The microcapsules had electric conductivity capability because of the advent of graphene. Experimental tests were carried out to characterize the physicochemical properties of microcapsule samples and microcapsules/bitumen composite samples. The following conclusions can be drawn:


Controlling thermal radiation is central in a range of applications including sensing, energy harvesting, and lighting. The thermal emission spectrum can be strongly modified through the electromagnetic local density of states (EM LDOS) in nanoscale-patterned metals and semiconductors. However, these materials become unstable at high temperature, preventing improvements in radiative efficiency and applications such as thermophotovoltaics. Here, we report stable high-temperature thermal emission based on hot electrons (>2000 K) in graphene coupled to a photonic crystal nanocavity, which strongly modifies the EM LDOS. The electron bath in graphene is highly decoupled from lattice phonons, allowing a comparatively cool temperature (700 K) of the photonic crystal nanocavity. This thermal decoupling of hot electrons from the LDOS-engineered substrate opens a broad design space for thermal emission control that would be challenging or impossible with heated nanoscale-patterned metals or semiconductor materials. Efficient control of thermal radiation is at the core of device design for a variety of applications. Here, the authors demonstrate a high-temperature thermal emitter with selective emission from a graphene-silicon photonic crystal nanocavity. The desire to control the thermal emission spectrum has a long history, notably including the 1885 invention by Carl Auer von Welsbach of the Actinophor gas mantle, which dramatically improved gas-lamp radiative efficiency, and in modern times the development of spectrally selective thermal emitters to boost the efficiencies of solar energy harvesting4, the spectral energy density of a blackbody follows u = E(ω)nD(ω), where E(ω) and n are the mode energy and the mode photon occupation, respectively, and D(ω) is the electromagnetic local density of states (EM LDOS). By controlling the LDOS in a sub-wavelength optical structure, it is possible to strongly modify the thermal emission spectrum. A variety of structures have been developed to tailor thermal radiation in this way, including optical gratings5, photonic crystals7, photonic cavities9, nano-antenna10, and metamaterials13. These demonstrations highlight the control of thermal emission by control of the LDOS, but face challenges in high-temperature stability as melting, evaporation, chemical reactions, surface diffusion, and delamination become severe for these nanoscale-patterned metallic and semiconducting materials. Thus, although high-temperature thermal emitters could greatly increase radiative efficiency for high-temperature thermophotovoltaics (TPVs) and light sources, it remains difficult to tailor thermal emission at elevated temperatures beyond about 1000 K by engineering LDOS.In the modern formulation of blackbody radiation19 and carbon nanotubes22, have emerged as intriguing thermal emitters alternative to metal and semiconductor-based materials. Previous demonstrations show that they can support high saturation current density19, ultrafast heating (cooling) modulation22, and flexible integration with existing electronic and photonic technology21. Here, the graphene–photonic crystal structure thermal emitter system addresses the challenges of high-temperature thermal radiation control by (i) direct heating of the electron gas in monolayer graphene, and (ii) coupling of this thermal emitter to a silicon planar photonic crystal (PPC) nanocavity. This approach has two key advantages: (i) the thermal emission that arises from the graphene electron gas, whose temperature is highly decoupled from graphene’s atomic lattice, can exceed 2000 K, while the surrounding Si cavity itself stays at only 700 K. (ii) The PPC cavity strongly modifies the LDOS, producing a sharp redistribution of the hot electrons’ thermal emission into the desired spectral regions.Nanocarbon-based materials, including graphene14. Because hot electrons in graphene thermalize much faster via electron–electron and optical phonon scattering than acoustic phonon scattering26, the heated electrons first reach equilibrium with optical phonons in graphene and hBN, coupling more slowly to the acoustic phonon bath by thermal conductance γe. The heat eventually dissipates to the silicon substrate (via γ0), which can remain at a much lower temperature than the electron gas of graphene, as depicted in Fig. As shown in Fig. 27. An air-slot along the center of the PPC confines light longitudinally and extends the optical modes above and below the silicon membrane28. Finite-difference time-domain (FDTD) simulations indicate strongly confined optical modes in the air-slot cavity, as seen in the |E|2 in Fig. E is the electric field. This air-slot cavity increases the coupling rate with a 2D material on the PPC surface by almost a factor of three compared with a linear three-hole defect (L3) cavity29. We further etched the hBN/graphene/hBN stack into a bowtie shape and aligned the central narrow strip to the PPC cavity area. This bowtie-shaped graphene facilitates a heated hot-electron spot in the graphene device to achieve optimal coupling of the hot-electron radiation to the cavity resonant field. Figure We created the wavelength-scale PPC cavity by introducing a line defect with shifted air holes near the centerQ of 1500, 2000, and 2300, respectively. After the hBN/Graphene/hBN deposition, the cavity resonances red-shifted to 1559.1, 1568.2, and 1590.7 nm, respectively, due to higher refractive index of hBN and graphene than air. The Q factors dropped to 520, 430, and 400, respectively, because of the excess absorption of graphene to the cavity field. The degradation of Q due to the 25-nm-thick hBN layers is negligible, as tested in separate PPC cavities without graphene, consistent with simulations  vertically coupled to the cavity. The reflection spectrum of the cavity before graphene deposition  of the graphene device as a function of the applied drain-source voltage VDS. The differential resistance Rdiff = (dIDS/dVDS)−1 increases with VDS, which is a signature of self-heating and strong electron scattering by hot optical phonons in graphene and hBN33. The measured thermal emission spectra, plotted in Fig. VDS voltages from 10 to 13 V, show three pronounced narrowband peaks that match the the cavity resonant modes as obtained from the reflection measurement shown in Fig. Figure 34. The frequency-dependent absorption of graphene can the be expressed asQ0 and Qg are the quality factors of the cavity before and after graphene deposition, respectively, ω0 is the resonant frequency and η ~0.1, as calculated from 3D FDTD simulations. The spectral radiance of the cavity-graphene emitter therefore equals TBB is the blackbody temperature, and TBB = 2000 K, matching the measured peak intensity of the cavity-graphene emitter at VDS = 13 V. From the radiation peak intensity I(ω0) of the graphene emitter at different bias voltages (VDS), it is possible to extract the electron temperatures of graphene with respect to VDS, as the red circles shown in Fig. We can extract the temperature of the hot graphene electrons from thermal emission spectra and the absorption of graphene in the cavity. From Kirchoff’s law, the emissivity of graphene is equal to its absorption, which can be obtained from temporal coupled-mode theory that incorporates the coupling of graphene to the optical modes inside a cavityVDS = 13 V. The red and blue curves represent the emission spectra that are collected at polarization angles parallel (ϕ = 0°) and perpendicular (ϕ = 90°) to the x-axis of the cavity. The intensity of the thermal emission collected at ϕ = 0° shows a strong, 15-fold enhancement compared with that collected at ϕ = 90° at the resonant wavelength of 1585 nm. The polar plot in the inset of Fig. ϕ at the resonant (cyan) and non-resonant (purple) wavelengths. A clear polarization-dependent on-resonant emission spectrum that varies with cos ϕ is consistent with the radiation of the cavity resonant mode and further confirms the coupling of the thermal emission of graphene to the PPC cavity modes.Figure Te) in graphene also affects graphene’s electronic transport properties, providing a second approach to validate Te in graphene. As shown in Fig. G, of the graphene sheet as a function of gate-source voltage (VGS) at different VDS voltages. When VDS is small, the thermally activated free carrier density nth in graphene is less than the gate-source voltage controlled carrier density ng. Thus, ng dominates the conduction of graphene, and G shows a strong gate (VGS)-dependence. At larger VDS, the elevated electron temperature Te results in higher nth that then dominates the conductance of graphene. Therefore, G only shows weak variation as VGS (ng) changes.The elevation of the electron temperature eμ(Te), where e is the electron charge. In our model, we use a temperature-dependent mobility of graphene based on a drift velocity-field relation38, giving μ(Te) = μ0(T0/Te)β, where μ0 = 20,000 cm2 V−1 s−1 is the mobility of graphene at 300 K and β = 2.3 is extracted from the electro-thermal simulation based on the measured current–voltage in Fig. G along the source-drain channel is ξ ~4 is the geometry factor and rc is the temperature-dependent contact resistance of graphene  with λ(TSi) = λ(T0) + α(TSi−T0), where α = 0.1 nm · K−1 and T0 is the ambient temperature (300 K). Figure VDS.The thermal emission in Fig. A striking conclusion is that the electron gas temperature of graphene Fig.  far exceT from 0.1 to 2 ns, we observed that the emission intensity started to saturate for ΔT > 1 ns, corresponding to a saturation temperature of 1550 K, as shown in Supplementary Fig. 15, an optimized graphene device allows an on–off modulation speed of the thermal emission at a rate exceeding 10 GHz—comparable to fast gain-switched lasers.As shown in Fig. 40. We estimate that the cavity-coupled hot-graphene light source demonstrated here would inject 0.2 photons into a waveguide per 100-ps pulse  still thermalize much faster than acoustic phonons in multilayer graphene and graphite44.This chip-integrated, spectrally controlled black-body radiator can serve as a useful light source for optical communications with low-power requirements. For example, many forms of discrete-variable quantum key distribution (QKD) require light sources that can be modulated at several GHz, in which consecutive pulses are phase-randomized , and with <1 photon per pulse45. (2) The fan-out of the graphene layer to the metal contacts produces relatively low contact resistance, approximated to be 65 Ω per contact . Even higher electron gas temperatures up to 2800 K, which were reported for suspended graphene monolayers, could further improve the emitter’s radiative efficiency.We briefly comment on the key features that lead to the high modulation speed and the exceptionally high temperature of the thermal emitter. (1) The bowtie shape of the hBN-encapsulated graphene allows precise spatial coupling of the hot electron gas at its narrowest section with the nanocavity; future work could further improve the mode overlap by a smaller (<100 nm) taper of the graphene layer coupled to slot-mode nanocavities14) and longer wavelength (mid-IR and beyond) spectral regions.In conclusion, we have demonstrated an electrically-driven on-chip thermal emitter based on a hBN/graphene heterostructure. The hBN-encapsulated graphene device achieves a temperature up to 2000 K through Joule heating, producing pronounced thermal radiation in the infrared spectrum. Coupling this hot-electron thermal emitter to a PPC cavity enables spectrally-selective thermal radiation control at a stable emission temperature of 2000 K, while the cavity itself remains cool (700 K) because of mismatched electron-optical photon and electron-acoustic phonon coupling in graphene. This device enabled the strongest modification of the black-body radiation in the near-infrared spectrum. Because of the broadband absorption of graphene and its stable emission temperature of more than 2000 K, this graphene-PPC cavity concept can be extended to shorter 49, plasmonic50, and nonlinear optical devices52. In separate experiments, we have shown that the thermal emitter can be on–off modulated at rates exceeding 10 GHz15, suggesting applications for easy-to-integrate on-chip optical interconnect or QKD light sources. The tailored narrowband thermal emission spectrum and the flexible integration of 2D materials may also find applications in thermophotovoltaics, and on-chip light sources for sensing54 and spectroscopy.Two-dimensional materials and their heterostructures have shown great flexibility for their assembly onto a variety of bulk materials and their photonic systems. These heterogeneously integrated 2D photonic components have emerged as a versatile platform for photodetectorsa = 470 nm and an air hole radius r = 0.29a. A 30-nm-thick hafnium oxide (HfO2) layer deposited on the PPC substrate by atomic layer deposition ensures electrical isolation between Si and the 2D materials.The PPC cavities were fabricated on a silicon-on-insulator (SOI) wafer using a series of electron-beam lithography (EBL), reactive ion etching, and a wet-etch undercut of the insulator to produce free-standing membranes. The silicon membrane has a thickness of 220 nm with a PPC lattice period of 55. The total thickness of the two BN layers is around 25 nm. Patterning the hBN/Graphene/hBN stack with hydrogen-silsesquioxane (HSQ) resist and CHF3 + O2 plasma exposed the edges of graphene, which were subsequently contacted by Cr/Pd/Au (1/20/50 nm) metal leads using electron-beam evaporation. The entire device is then etched again by CHF3 + O2 plasma to form the bowtie geometry.Graphene and hBN were prepared by mechanical exfoliation. We then transferred the exfoliated hBN/graphene/hBN stack onto the PPC using a van der Waals assembly techniqueSupplementary Figure λ is the radiation wavelengths and W0 is the Gaussian beam waist size. The blue dashed line in Supplementary Fig. TBB = 2000 K scaled by 0.072 to compare with the measured cavity-graphene radiation. Figure The throughput of the optical system was calibrated using a calibrated blackbody (BB) source from 373 to 1255 K with an emissivity of 0.99 (OMEGA-BB-4A). For temperature >1255 K, we first normalized the detector response to the BB source measured at moderate temperature (1255 K), and then verified the linear response of the InGaAs detector using the supercontinuum laser at high optical intensity to ensure a valid calibration. Based on the calibrated system response, the blackbody spectral radiance can be obtained considering the collection of a Gaussian spatial mode by the objective with surface area We used a time-correlated single photon counting (TCSPC) method to gauge the temporal response of the cavity-graphene emission in Fig. a/60, and the refractive index of silicon and hBN were 3.47 and 1.8, respectively. The electro-thermal simulation shown in Supplementary Fig. The cavity mode profile and far-field emission pattern shown in Fig. Supplementary InformationPeer Review File


Carbon‐based metal‐free catalysts for the hydrogen evolution reaction (HER) are essential for the development of a sustainable hydrogen society. Identification of the active sites in heterogeneous catalysis is key for the rational design of low‐cost and efficient catalysts. Here, by fabricating holey graphene with chemically dopants, the atomic‐level mechanism for accelerating HER by chemical dopants is unveiled, through elemental mapping with atomistic characterizations, scanning electrochemical cell microscopy (SECCM), and density functional theory (DFT) calculations. It is found that the synergetic effects of two important factors—edge structure of graphene and nitrogen/phosphorous codoping—enhance HER activity. SECCM evidences that graphene edges with chemical dopants are electrochemically very active. Indeed, DFT calculation suggests that the pyridinic nitrogen atom could be the catalytically active sites. The HER activity is enhanced due to phosphorus dopants, because phosphorus dopants promote the charge accumulations on the catalytically active nitrogen atoms. These findings pave a path for engineering the edge structure of graphene in graphene‐based catalysts. Metal‐free catalysts, in particular graphene‐based catalysts, have been utilized in fuel cells,2 nanosheets,Electrochemical measurements have been used for visualizing catalytic activity at the nanoscale.Here, by combining the SECCM technique with atomistic characterizations and density functional theory (DFT) calculations, we unveil the molecular mechanism behind the HER acceleration in edge‐enriched chemically doped graphene. We synthesized edge‐enriched graphene with chemical dopants near the edges created by holes in graphene lattices, and found that nitrogen/phosphorus (NP) codoped graphene provides much better HER activity than edge‐enriched graphene without any chemical dopants and edge‐enriched graphene with solo nitrogen (N) or phosphorous (P) dopants. The SECCM measurements reveal that the NP‐dopants on the edge of holey graphene significantly enhance the electrochemical current. The DFT calculation suggests that NP‐dopants situated on the edges enhance the contrast of the positively and negatively charges on atom's sites, lowering the Gibbs free energy of the HER process. A unique combination of the synthesis of the edge‐enriched doped graphene, SECCM measurement, and DFT calculation illustrates that chemical dopants located in the edges around the graphene edge structures improve the electrochemical properties, compared with edge‐free chemically doped graphene and edge‐enriched nondoped graphene. The obtained results provide insight into the rational design of metal‐free catalysts.Figure2 nanoparticle level.2 g−1, respectively . Raman spectra were measured in conjunction with the corresponding optical images to reveal the relationship between the edge‐enriched morphology and the graphene lattice. The defect density on the NP‐doped graphene with edge structures was indicated by the ratio of D and G bands in the Raman intensity spectra (ID/IG)  were higher than that in the nondoped sample (ID/IG = 0.72), implying that the dopants affected the defect density of the edge . The number of graphene layers was indicated by the intensity ratio of the 2D and G bands (I2D/IG); the chemically doped graphene samples (I2D/IG = 1.56−3.2) were composed mainly of several‐layer graphene, with high crystallinity of the graphene structures, and without detectable amorphous carbon features . Therefore, we conclude that the curvature and ligament radii of the graphene are insensitive to the presence of edges; the edges only induce the high defect density in the edge regions due to their defective structures.We synthesized N‐doped, P‐doped, NP‐codoped graphene with edge‐enriched structures by porous‐metal‐based chemical vapor deposition (CVD).FigureID/IG values found from Raman mapping . The edge‐enriched chemically doped graphene demonstrates randomly oriented tubular ligaments composed of graphene layers Figure2a. Theg Figure b. Our re3) (132.1–132.9 eV).−1 by inductivity coupled plasma optical emission spectrometer analysis, while they could not be detected by X‐ray diffraction (XRD) . The quantitative XPS measurements are summarized in Table S2 (Supporting Information). To understand the influence of the edges on the chemical binding, we compared the spectra of NP‐doped graphene with and without edges, grown under the same CVD conditions . The existence of edges affected the total dopant level (1.03 at% increase), and the fraction of pyridinic nitrogen showed relatively higher atomic concentrations in the edge‐enriched NP‐doped sample .The chemical binding state and quantitative chemical composition were investigated by X‐ray photoelectron spectroscopy (XPS) . The peaks in the C 1s XPS spectrum of the NP‐doped sample signify high quality graphene without any carbides. Furthermore, the N 1s XPS spectrum reveals that the N‐dopant forms graphitic, pyridinic, and oxide structures, without any nitrides;TableTo confirm the selective chemical doping into the graphene edge, we have performed DFT calculations with nondistorted and distorted (≈6% lattice shrinkage) graphene models to determine total energy of chemically doped graphene at the edge region Figure e,f. The Figurem H2SO4 electrolyte. The overpotentials, η, at a current density of 10 mA cm−2, were 344 mV (NP), 477 mV (N), 522 mV (P), 571 mV (G), and 453 mV (edge‐free NP). Moreover, the approximate turnover frequencies (TOFs)2/s) exhibited a higher TOF than the edge‐free NP sample (0.45 H2 s−1). The NP‐sample exhibits the highest HER activities among the synthesized graphene samples. Electrochemical impedance spectroscopy was employed to investigate the charge transfer properties . By assuming an equivalent circuit consisting of a parallel combination with a charge‐transfer resistances (Rct) and an electrochemical double‐layer capacitance (Cdl), we can fit the half‐circle Nyquist plots to analyze their Rct at an electrode potential of −300 mV (V vs RHE). The Rct values were 21.5 Ω (NP), 73.2 Ω (N), 125 Ω (P), 1017 Ω (G), and 48.1 Ω (edge‐free NP). The NP‐sample clearly exhibits the lowest charge‐transfer resistance, which could accelerate the HER kinetics and increase catalytic activity. Both η and Rct are lowered by the generation of edges on the NP‐sample, manifesting that the edges will enhance HER activities. The electrochemical stability over cycling and durability test at the potential of −0.34 V (V vs RHE) of the NP‐sample was examined in 0.5 m aqueous H2SO4 electrolyte . The sample maintained 85% and 91.6% of its current density after 1000 cycles and 1 day, respectively.We subsequently measured the HER performance of solo N‐doped, solo P‐doped, and NP‐codoped graphene samples with edge‐enriched structures, as well as of nondoped (G) and edge‐free NP‐doped samples, together with the commercial Pt catalyst. Cdl  to generate hydrogen molecules determines the HER rate.Cdl, can be qualitatively compared by evaluating the Cdl values of the graphene samples on the basis of cyclic voltammetry (CV) at various sweep rates , 10.4 mF cm−2 (N), 8.5 mF cm−2 (P), 7.4 mF cm−2 (G), and 5.2 mF cm−2 (edge‐free NP). The hydrophilic character was significantly enhanced by the addition of chemical dopants containing edges as confirmed by contact angles . The chemically doped graphene samples with edge structures had decreased Tafel slopes and increased Cdl values, thus promoting HER. Moreover, we examined the dependence of edge/plane area ratio on hydrodynamic voltammograms to investigate the area balance, by preparing samples with various amounts of SiO2 nanoparticles which disturb graphene growth (1 × 10−4 to 1 × 10−3 wt%), as this correlates with edge and plane area by tuning the amount of edges . Chemically doped graphene , less‐dosed edge graphene , and overdosed hash graphene  all have lower HER performances than that with an optimal amount of SiO2 nanoparticles  under similar CVD conditions . Furthermore, concentration dependences of chemical doping level were compared to examine the influence of chemical dopant level and holes . The NP‐doped graphene  without holes demonstrates that higher chemical doping level shows higher HER performances which is consistent with previous reports.−2 than NP‐doped graphene (2.42 at%) without holes. These indicates that creating an appropriate edge/plane area ratio at the same chemical doping level is important for enhancing the HER.To obtain information about the catalytic activity, Tafel plots Figure b and Cdl Figure c of the Figure2 s−1 and the TOF values for chemically doped graphene were about 100–200 times higher at the edge than the plane regions, and about 10–80 times higher at the edge on the G‐sample than that for the plane regions on the G‐sample. This clearly indicates that the difference of HER current between the edge and plane regions is much larger for the NP‐sample than for the G‐sample. Thus, we can directly prove that combined chemical doping and edge‐engineering can enhance the HER activity drastically.To link the local configurations with the electrochemical HER activity at a nanometer scale, we used operando electrochemical measurements for real‐space electrochemical mapping with SECCM. + + e− to 1/2 H2 via H* adsorption.GH*|, close to zero. The SECCM mapping results displayed in Figure GH*| of the NP‐doped graphene with edges than nondoped graphene with edges. The DFT calculation indeed suggests that |ΔGH*| of the NP‐doped graphene with edges is comparable with the |ΔGH*| of 0.08 eV for Pt. Note that the |ΔGH*| is calculated by choosing the highly active sites near edges . This was followed by N‐doped graphene with edges (ΔGH* = −0.46 eV); however, the other samples have much larger |ΔGH*| values. Such a trend is consistent with the HER activity data . To understand the mechanism behind the lowering of |ΔGH*|, we analyzed the charge distribution. The partial charge distributions of the edge atoms on the NP‐doped graphene with and without the edges  At the edge, the nitrogen and carbon atoms neighboring phosphorous are negatively charged, and phosphorus and carbon atoms neighbouring nitrogen are positively charged. P‐dopants at the edge of graphene enhance the charge on the pyridinic nitrogen, which improves the activity of the pyridinic nitrogen. The edge structure also enhances charge accumulation on the carbon atoms near chemical dopants; in average, the charge is enhanced by 30–50%. This leads to high wettability of the graphenes . Thus, we propose that positively and negatively charged edge regions induced by chemical dopants and defects create additional ECSA‐containing catalytic sites on the edge‐enriched graphene, as reported previously.The lowering of |ΔCatalytic activity in chemically doped graphene with edge structures arises from the inhomogeneous spatial distribution of chemical dopants and their configuration of chemical binding. The edge brings geometrical frustration to the graphene lattice, which accumulates chemical dopants and tailors HER active configurations near the graphene edge, while defect‐less graphene layers in relatively low‐dosed plane regions support electron transfer to the edge regions. Thus, these regions cooperatively work to enhance the reaction kinetics. The DFT‐calculated Gibbs free energy and charge population demonstrate that the graphene edge tunes the H* adsorption and desorption, and creates positively and negatively charged states, thereby benefitting the HER processes.The operando SECCM analysis allowed us to link the electrochemical HER current with graphene structures for visualizing where the catalytically active sites are. Only the chemically codoped edges demonstrate high HER activities by the synergetic effect of nitrogen and phosphorus codopants at edge‐enriched region. Conversely, edge‐free regions, or regions in which the chemical dopant level is relatively low, do not show high catalytic activities. This indicates that both chemical dopants concentrated near the edges Figure d and edgBy combining HER performance measurements, electrochemical current probes through SECCM, atomic conformation obtained by HR‐TEM, and DFT calculations, we studied the electrochemical activity of chemically doped graphene with edge structures. We found that the combination of chemical doping and edge engineering can increase the HER activity drastically. To understand the underlying mechanism, we directly visualized the electrochemical HER current by SECCM, which suggested that chemical dopant‐enriched edge structures can effectively enhance electrochemical hydrogen evolution. The DFT calculation indicates that the contrast of the charge intensities of atoms at an edge is enhanced due to the presence of the edge, improving the activities of the pyridinic nitrogen. As a result, Gibbs free energies for H* adsorption in NP‐doped graphene with edge structures are similar to that of Pt. Such edge engineering approaches provide a good understanding and new design principles to exploit intrinsic metal‐free catalysts. Moreover, graphene‐based electrocatalysts have large space to further improve their catalytic activity when we suitably combine several enhancement factors such as conductivity, chemical dopants, topological defects, configuration of chemical bonding, chemical doping level, surface area, edges, and 3D porous structure.The authors declare no conflict of interest.SupplementaryClick here for additional data file.


While there is increasing interest in the regulation of PD-L1 expression in cancer and immune cells, the expression and regulation of PD-L1 in other stromal cells, such as PSCs, has not been fully evaluated. Here we show that PSCs in vitro express higher PD-L1 mRNA and protein levels compared to the levels present in PDAC cells. We show that inhibitors targeting bromodomain and extra-terminal (BET) proteins and BRD4 knockdown decrease interferon-γ (IFN-γ)-induced PD-L1 expression in PSCs. We also show that c-MYC, one of the well-established targets of BET inhibitors, does not mediate IFN-γ-regulated PD-L1 expression in PSCs. Instead we show that interferon regulatory factor 1 (IRF1) mediates IFN-γ-induced PD-L1 expression in PSCs. Finally, while we show that BET inhibitors do not regulate IFN-γ-induced IRF1 expression in PSCs, BET inhibitors decrease binding of IRF1 and BRD4 to the PD-L1 promoter. Together, these results demonstrate the interplay between IRF1 and BRD4 in the regulation of PD-L1 in PSCs.The fibrotic reaction is a characteristic feature of human pancreatic ductal adenocarcinoma (PDAC) tumors. It is associated with activation and proliferation of pancreatic stellate cells (PSCs), which are key regulators of fibrosis  For example, increased expression of PD-L1 in non-small cell lung cancers has predictive value for response to antibodies targeting PD-1/PD-L13. However, the predictive value for response to immune checkpoint inhibitors in other tumor types, e.g., bladder cancer4, correlates with PD-L1 expression by infiltrating immune cells and not by cancer cells1. While there is increasing interest in identifying mechanisms regulating PD-L1 expression in cancer and immune cells, the expression and regulation of PD-L1 in other stromal cells, such as fibroblasts, has not been fully evaluated. Importantly, the stroma in some tumors can account for a significant portion of the tumor mass. For example, the stroma in human pancreatic ductal adenocarcinoma (PDAC) tumors, which can account for as much as 80–90% of the tumor mass, is associated with proliferation of pancreatic stellate cells (PSCs)6. The PSCs are the predominant fibroblasts present in human PDAC tumors and the key regulators of fibrosis in vivo5.PD-L1 expression is seen in a number of human cancers, with increased expression of PD-L1 by cancer cells in some tumor types can be associated with responses to antibodies targeting PD-1/PD-L17. The BET proteins, which include BRD2, BRD3, BRD4, and the testis-specific BRDT, regulate transcription of genes involved in several human diseases9. These proteins bind to acetylation motifs present in histones and enable recruitment of transcription factors and other chromatin regulators during RNA transcription9. Importantly, a number of selective and potent small-molecule BET inhibitors are currently being evaluated in clinical trials for solid tumors9. In addition, inhibitors that promote degradation of BET proteins through proteolysis-targeting chimera (PROTAC) are also being developed13. While BET inhibitors were recently shown to repress PD-L1 expression in lymphoma and ovarian cancer cells15, the contribution of BET proteins to the regulation of PD-L1 expression in PSCs has yet to be evaluated.Recently, we showed that inhibitors targeting bromodomain (BRD) and extra-terminal (BET) proteins induce primary PSCs isolated from human PDAC tumors to become quiescent18, does not mediate IFN-γ-mediated PD-L1 expression in PSCs. Instead we show that interferon regulatory factor 1 (IRF1) mediates IFN-γ-induced PD-L1 expression in PSCs. Finally, while we show that BET inhibitors do not regulate IFN-γ-induced IRF1 expression in PSCs, BET inhibitors decrease binding of IRF1 and BRD4 to the PD-L1 promoter. Together, these results demonstrate the interplay between IRF1 and BRD4 in the regulation of PD-L1 in PSCs.In this report, we show that PSCs express higher PD-L1 mRNA and protein levels compared to the levels present in PDAC cells. We show that BET inhibitors, BET PROTAC and BRD4 knockdown decrease interferon-γ (IFN-γ)-induced PD-L1 expression in PSCs. We also show that c-MYC, one of the well-established targets of BET inhibitors5, and the immune cells are very likely to encounter these cells in vivo, we evaluated expression of PD-L1 in an immortalized PSC cell line and in primary PSCs isolated from human PDAC tumors using the outgrowth assay19. Human PSCs express PD-L1 mRNA, which in most cases exceeded the PD-L1 mRNA levels present in human PDAC cell lines  regulated IFN-γ-induced PD-L1 expression in lung, liver and colon cancer cellsSCs Fig.  and in tSCs Fig. .Figure 6IRF1 expression in primary PSCs and the stellate cell line.We next evaluated the effects of JQ1 and I-BET151 on IFN-γ-induced IRF1 expression. While IFN-γ increased IRF1 expression, pre-treatment with JQ1 or I-BET151 had minimal effects on IFN-γ-induced IRF1 expression in primary PSCs and in the stellate cell line Fig. . BET inh15, we initially evaluated the effect of BET inhibitors on the recruitment of BRD4 to the PD-L1 promoter in the stellate cell line. Treatment with IFN-γ increased binding of BRD4 to the PD-L1 promoter in the stellate cell line, which was inhibited in the presence of JQ1 , BRD3 (ab50818), BRD4 (ab128874) and IRF1 (ab26109) antibody for chromatin immunoprecipitation (ChIP) were obtained from Abcam. Antibodies against c-MYC (5605), human PD-L1 , IRF1 (8478) and control IgG (2729) antibody for ChIP were purchased from Cell Signaling Technology. Anti-BRD4 (A301–985A) antibody for ChIP was obtained from Bethyl Laboratories. PE-conjugated human PD-L1  antibody was from Thermo Fisher. The GAPDH (MAB374) antibody was from Millipore, and α-tubulin (sc-8035) antibody and HSP90 (sc-7940) antibody were obtained from Santa Cruz Biotechnology. Secondary anti-mouse IgG (A4416) and anti-rabbit IgG (A6667) antibodies were purchased from Sigma. The BET inhibitors JQ1 and I-BET151 were obtained from Tocris Bioscience, the BET PROTAC ARV-825 was obtained from MedChem Express, and human and mouse IFN-γ was purchased from Thermo Fisher Scientific. The siRNAs against BRD2, BRD3, BRD4, c-MYC, and IRF1 were purchased from Thermo Fisher Scientific.32. KPC22, KPC105, KPC163 and KPC344 – all derived from PDAC tumor developing in the KPC (Kras/p53) mouse model in B6 background – were obtained from Sam Grimaldo . KPC1245 and KPC1199 cells, both derived from KPC tumors developing in B6 background, were provided by David Tuveson 34. Mouse Pan02 cells were purchased from the NCI.Human PDAC cell lines AsPC1, BxPC3, CD18/HPAF-II, MiaPaca2, Panc1 and Panc02–03 were obtained from ATCC. Chemo-resistant CD18 (CD18-CR) cells were generated by treating parental CD18 cells with increasing concentration of 5-fluorouracil (5-FU) over a period of 3 months37, was obtained from Dr. Rosa F. Hwang . The immortalized mouse pancreatic stellate cell lines mPSC#2 and mPSC#3, which were immortalized with SV40 large T antigen38, were obtained from Dr. Raul Urrutia . Primary PSCs were generated from de-identified fresh human PDAC specimens using primary outgrowth cultures, which have been shown to be a reliable source of human pancreatic stellate cells19. The primary PSCs were used within 5–6 passages from isolation.A human pancreatic stellate cell line, which was immortalized with telomerase and SV40 large T antigen32.The human stellate cell line and the primary PSCs were transfected with siRNA against BRD2, BRD3, BRD4, c-MYC, IRF1 or control siRNA (20 nM) using RNAimax (Thermo Fisher Scientific) according to the manufacturer’s instructionsCT method for relative gene expression32.Quantitative gene expression was performed with gene-specific TaqMan probes, TaqMan Universal PCR Master Mix, and the 7500 Fast Real-time PCR System from Applied Biosystems. The data were then quantified with the comparative 15.The human stellate cell line was pre-treated with JQ1 for 30 minutes, treated with IFN-γ for 4 hours, and then treated with formaldehyde to create DNA-protein cross-links. Chromatin fragments were prepared using EZ-Zyme Chromatin Prep kit  and ChIP performed using the EZ-Magna ChIP A/G Chromatin Immunoprecipitation kit  and anti-BRD4 antibody , anti-IRF1 antibody  or control IgG antibody . Purified DNA was then analyzed by PCR using KiCqStart SYBR Green qPCR ReadyMix  and primers specific for the PD-L1 locus: forward 5′-AAGCCATATGGGTCTGCTC-3′ and reverse 5′-TTATCAGAAAGGCGTCCCCC-3′32.Immunoblotting for BRD2, BRD3, BRD4, c-MYC, IRF1, PD-L1, α-tubulin, GAPDH and HSP90 was done as described previously32.PDAC cells and PSCs in suspension were incubated with PE-conjugated anti-PD-L1 antibody and co-stained with DAPI prior to analysis with BD LSR Fortessa 6-Laser flow cytometerPancreatic tissue was obtained from patients with PDAC undergoing resection on a protocol approved by the Institutional Review Board of Northwestern University. Informed consent was obtained from patients prior to resection. The resected specimens were deidentified and subsequently processed for isolation of primary PSCs. All experiments were performed in accordance with relevant guidelines and regulations.t-test analysis. Error bars represent standard deviation.All statistical analyses were done using Microsoft Excel using a two-tailed Supplemental Figures 1-3


Phocoenoides dalli) is one of most common North Pacific porpoise species, for which information on sound-emitting processes is limited. To evaluate the mechanism of click emission in the head of this porpoise, the distribution of acoustic impedance in head tissues was calculated using density and Young’s modulus‘which is a measure of linear resistance to linear compression. Two Dall’s porpoise heads were examined: one for macroscopic dissection, and one for investigating the distribution of acoustic impedance calculated from CT-measured density, and Young’s modulus measured by creep meter. Acoustic impedance increased from the dorsal bursae to the melon’s emitting surface, with impedance matching observed at the boundary between the emitting surface and seawater, and was more similar in distribution to Young’s modulus than it was to density. The distribution of acoustic impedance differed from that of harbor porpoise (Phocoena phocoena), despite similarities in the sound-producing organs in the heads of Dall’s and harbor porpoises. A comparison of the physical properties of Dall’s and harbor porpoise head tissues suggests that hypertrophic vestibular sacs and an oval emitting surface are common characteristics in Phocoenidae.Dall’s porpoise ( Phocoenoides dalli ) is a small toothed whale found in the North Pacific Ocean and adjacent Bering Sea, Okhotsk Sea and Sea of Japan [Phocoena phocoena) and finless (Neophocaena phocaenoides) porpoises use NBHF clicks [Dall’s porpoise li True, 885) is aof Japan –3, thereof Japan , and widF clicks –8.85 is aofAnatomical studies have contributed significantly to our understanding of click-emitting processes. Clicks are produced by trembling of the phonic lips, including two pairs of dorsal bursae –10. PhonTursiops truncatus) are well known comparing to Dall’s porpoise. One contributing factor will be that, to the best of our knowledge, Dall’s porpoises have not been maintained continuously in captivity by any institute or aquarium. With the exception of a conventional study [The click-emitting processes of the harbor porpoise and bottlenose dolphin  imaging, and measurement of physical properties, two adult male Dall’s porpoise carcasses  were procured. Both animals were retrieved dead, having been accidentally caught in set nets at Rausu, Hokkaido, Japan on 25 June 2014. Heads were severed and stored at −20°C for examination: both specimens were examined by CT; SNH14026-2 was used for density measurement and Young’s modulus scanning, and SNH14026-1 was subsequently fixed in 10% formalin for macroscopic dissection.ρ) from CT value (U) ; for SNH14026-1 and SNH14026-2, helical pitches were 0.5mm and 1mm, and the number of CT images were 709 and 321, respectively. Tube voltage was 120 kV, and tube current 150mA. After scanning, CT values  were obtalue (U)  was propYoung’s modulus, also called as longitudinal elastic modulus is a measure of linear resistance to linear compression and defined as the slope of the linear region of the stress-strain diagram. measurement was performed following our previous study . Young’sZ) was calculated from Young’s modulus (E) and tissue density using (ρ) using:Acoustic impedance  are depicted in 6 Pa s/m from x = 59.47mm to 153.67mm, and increased to 1.454×106 Pa s/m at x = 31.79mm.Average density, Young’s modulus and acoustic impedance relative to distance from the rostrum for melon, dense connective tissue, blubber and air sacs, and distance from the tip of the upper lip to ES and dorsal bursae , the melon acoustic impedance was 1.454×106 Pa s/m . Conventional study [At the ES frontal tip . This r6 Pa s/m –14, 20. al study  suggesteThere was little difference in impedance in Dall’s porpoise melon tissues between 60mm and 120mm from the upper lip tip. This is a personal opinion based on the macroscopic observation of the tissue, but the muscles in the lower part of the melon of Dall’s porpoise was assumed to be richer in lipid than that of harbor porpoise . Dall’s In Dall's porpoise and harbor porpoise, the numerical values of Young’s modulus were particularly different in DCT. However, in this study, it was not possible to clarify why this numerical difference occurred and why such a difference was seen in DCT.It is difficult to relate these differences in acoustic impedance to clicks properties such as source pressure level and / or frequency characteristics. Dall’s and Harbor Porpoise use narrowband and high frequency (NBHF) clicks in common and have similar click spectrograms . However2 and 35.5cm2, respectively) exist. Ours is, as far as we are aware, the first account of such differences in ES size for these species. Similarities in VS structure and differences in ES size might be related to characteristic properties of acoustic clicks [The anatomy of the Dall’s porpoise Figs  and 2 hec clicks , 22. In c clicks .Dall’s porpoise is a fast-swimming coastal-to-offshore species that forms groups of 10 individuals or less, whereas the harbor porpoise lives in coastal areas, and is solitary or typically forms groups of several individuals only. Despite these differences in ecological and social habits, their sound-producing organs are similar in having hypertrophic VS and an oval ES. As a conventional study  also repOur method and results compared the sound-emitting process of Dall’s with harbor porpoises, and considerably improved our understanding of the physical properties of Dall’s porpoise head tissues. We consider the structure of sound propagating organs, and the click-emitting process of Dall’s porpoise to be similar to those of the harbor porpoise. This information improves our understanding of relationships between sound-propagating organs and the acoustic properties of clicks in these small-bodied toothed whales, and perhaps, as a generalization, throughout the family Phocoenidae.S1 FileCT data of SNH14026-1. File format is DICOM (.dcm).(DCM)Click here for additional data file.S2 FileEach CT image data i)—viii) indicates the surface of slice used for Young’s modulus measurement. Additional information for setting of CT scanner was added in the text file, named “S2 Supporting information.txt”.(ZIP)Click here for additional data file.S3 FileAll calculations and graphs were shown in sheet 1.(XLSX)Click here for additional data file.


Programmed cell death protein-1 (PD-1) and programmed cell death ligand 1 (PD-L1) inhibitors have remarkable clinical efficacy in the treatment of non-small cell lung cancer (NSCLC); however, the breakdown of immune escape causes a variety of immune-related adverse events (irAEs). With the increasing use of PD-1/PD-L1 inhibitors alone or in combination with other therapies, awareness and management of irAEs have become more important. We aimed to assess the incidence and nature of irAEs associated with PD-1 and PD-L1 inhibitors for NSCLC.Articles from the MEDLINE, EMBASE, and Cochrane databases were searched through December 2017. The incidence of overall and organ-specific irAEs was investigated in all clinical trials with nivolumab, pembrolizumab, atezolimumab, durvalumab, and avelumab as single agents for treatment of NSCLC. We calculated the pooled incidence using R software with package Meta.Sixteen trials were included in the meta-analysis: 10 trials with PD-1 inhibitors (3734 patients) and 6 trials with PD-L1 inhibitors (2474 patients). The overall incidence of irAEs was 22%  for all grades and 4%  for high-grade irAEs. The frequency of irAEs varied based on drug type and organ, and patients treated with PD-1 inhibitors had an increased rate of any grade and high-grade irAEs compared with patients who received PD-L1 inhibitors. Organ-specific irAEs were most frequently observed in, in decreasing order, the endocrine system, skin, pulmonary tract, and gastrointestinal tract. The total number of patients whose death was attributed to irAEs was 14 (0.34%), and most (79%) of these patients died because of pneumonitis. The median time to the onset of irAEs after the initiation of treatment was 10 weeks  and varied depending on the organ system involved.The specificity of irAEs was closely associated with the mechanism of PD-1/PD-L1 antibodies involved in restarting anticancer immune attacks. Comprehensive understanding, timely detection, and effective management could improve the compliance of patients and guide the interruption of treatment.The online version of this article (10.1186/s12885-019-5701-6) contains supplementary material, which is available to authorized users. Programmed cell death protein-1 (PD-1) is an important immunologic checkpoint inhibitor (ICI) that was discovered after cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4). In 2002, a study using cloned antibodies in a mouse model showed that local immunosuppression can be abolished by blocking the binding of PD-1 and programmed cell death ligand 1 (PD-L1)  and skin [10%  vs. 1% ], although the rates of high-grade irAEs were equivalent in the two groups  patients. Most deaths (79%) were related to pneumonitis.Our research identified 35 patients from 27 case reports with at least one irAE –60. ThreThe most common organ-specific irAEs described in the 27 case reports of 35 patients occurred in the endocrine system. Eleven (31%) cases were recorded and occurred, on average, within 8.5 weeks of anti-PD-1/anti-PD-L1 treatment  cases were diagnosed as acute interstitial nephritis by evidence of kidney biopsy. Immune therapy was withdrawn, and prednisone therapy was initiated from 60 mg/day and tapered over 1 month. The patients showed a prompt return to baseline kidney function .Colitis was the most frequent gastrointestinal irAE in clinical trials. However, possibly because of mostly mild symptoms, we only retrieved one case report describing pancreatitis , which pNeurologic irAEs reported in the literature included one case of cerebral vasculitis/encephalitis  and two Moreover, we retrieved two case reports describing pericardial effusion , 60 and Most studies were open label, single-arm trials and therefore had a high risk of selection bias, performance bias, and detection bias. This problem is mostly unavoidable in clinical studies of oncology owing to ethical considerations. Several researchers used a blinded, independent, central review to assess tumor primary endpoints but not adverse events , 26, 30.The application of immunotherapy, especially PD-1/PD-L1 inhibitors, has provided unprecedented efficacy gains in NSCLC treatment. With the promotion of single and joint application, two existing problems are becoming increasingly evident: unpredictable efficacy and inevitable irAEs. To the best of our knowledge, our study is the first meta-analysis and systematic review of irAEs following treatment of NSCLC with anti-PD-1 or anti-PD-L1. The most significant finding of the current study was that the incidence of any grade irAEs with anti-PD-1 treatment was higher than that with anti-PD-L1 treatment, and the trend was consistent with the incidence of high-grade irAEs. This finding was different from or even the opposite of the results of a previous systematic review that compared PD-1 inhibitors with PD-L1 inhibitors  . This maOrgan-specific irAEs occurred most frequently in the endocrine organs and skin, followed by the gastrointestinal tract and the pulmonary tract. Liver-related and kidney-related adverse reactions were rare. Adverse events affecting the heart, blood, and nerves have also been reported. The most frequent endocrine adverse effect was thyroid dysfunction, which included six cases of hypothyroidism, one case of hyperthyroidism, and one case of thyroiditis. This irAE is usually detected 3–4 weeks after drug intervention, with a trend of quick onset of hyperthyroidism and short lag time to the development of hypothyroidism . The exaSymptoms such as fatigue, weight loss, cold intolerance, and palpitations are common in oncology patients and have a high possibility of being missed or misdiagnosed. Delays in diagnosis and management may lead to worsening symptoms and further complications. Therefore, specialists should be vigilant and rigorously monitor confusing clinical symptoms and changes in laboratory parameters to promptly identify and manage irAEs. For example, thyroid changes are common after treatment with PD-1 inhibitors and require active laboratory monitoring. TSH levels should thus be measured before initiating anti-PD-1/PD-L1 treatment and every 4–6 weeks during treatment because nivolumab is administered intravenously every 2 weeks and pembrolizumab is administered intravenously every 3 weeks . In addiTissue pneumonia should be scrutinized to distinguish between immune-related and non-immune-related disease. Asepticity of the bronchial and alveolar samples, CD8+ lymphocyte-based alveolitis, and the presence of lung immune-reactive processes are important references for the diagnosis of immune-mediated organizing pneumonitis . FortunaIt should be noted that case reports were included in this review to qualitatively complement the quantitative conclusions of the companion meta-analysis, and the ability to draw statistical conclusions from case studies is limited because only novel or rare irAEs tend to be reported in the literature. Despite this limitation, the current body of case studies does show that several serious irAEs have occurred in patients treated with anti-PD-1/PD-L1 agents. However, immune-related deaths are rare (0.34%), which is consistent with a review of ICIs that reported that less than 1% of all patients had fatal events associated with ICI . NonetheThe leading cause of death in the studies we reviewed was pneumonitis, presumably because organ-specific irAEs are related to tumor type. However, systematic reviews of other tumor types will be required to verify this finding.An increasing number of lung cancer patients receive first- or second-line immunotherapy; therefore, early identification and management of irAEs is critical. Several guidelines and reports on patient care have thus been released. The European Society for Medical Oncology Guidelines Committee has developed clinical practice guidelines for the use of five PD-1/PD-L1 inhibitors alone, the use of ipilimumab alone, and the use of combined ipilimumab and nivolumab . FurtherWe did not examine differences in the incidence of irAEs at different treatment doses because most reported data only focus on trAEs, which do not exactly match the definition of irAEs. However, the only RCT that has evaluated the efficacy of pembrolizumab in patients with previously treated PD-L1-positive NSCLC and advanced NSCLC reported that adverse events of special interest based on immune etiology occurred in 69 of 339 patients (20%) in the 2 mg/kg group and 64 of 343 patients (19%) in the 10 mg/kg group . A meta-Our analysis showed that the incidence of irAEs is higher with PD-1 inhibitors than with PD-L1 inhibitors. PD-L1 inhibitors prevent PD-L1 from binding to PD-1, but they do not prevent programmed cell death ligand 2 (PD-L2) from binding to PD-1, which may allow potential immune-related toxicity attributed to PD-L2 blockade to be avoided .Another meta-analysis compared the efficacy of PD-1 and PD-L1 inhibitors in treating NSCLC and concluded that the tumor response rate was higher in the anti-PD-1 group than in the anti-PD-L1 group . The mecIndeed, it should be noted that the role of PD-1/PD-L1 inhibitors and agonists in predicting response rates and improving efficacy also affects the incidence of irAEs. For example, the main factors affecting the pembrolizumab response rate fall into two categories: those associated with tumor neoepitope burden, such as high tumor mutational burden, and those related to T cell-inflamed tumor microenvironment, such as PD-L1 . A combiCTLA-4 inhibitors are a class of ICIs that were discovered before PD-1/PD-L1 inhibitors. The overall incidence of irAEs with these ICIs has been reported to be 72% for all-grade malignant tumors and 24% for high-grade malignant tumors . This inThe irAEs reported after the deadline of the literature search tended to be high-grade and fatal and include hypophysitis , type I Our research had the following strengths. Firstly, our study is the first meta-analysis and systematic evaluation of irAEs after treatment of NSCLC with anti-PD-1 or anti-PD-L1 and reconciled previous contradictory results. Secondly, the use of the Common Terminology Criteria as an outcome metric for irAEs is clinically relevant and readily interpretable by practicing oncologists. Furthermore, the utilization of case reports in studies of this nature is relatively novel, and a comprehensive review of the treatment and prognosis status of irAEs compensated for the weakness related to publication bias to some extent. In addition, the integration of the Cochrane risk of bias tool allowed us to highlight that clinical studies of immunotherapy are often not randomized studies, but single-arm trials. Finally, the imputation of event counts of zero with 0.5 allowed trials that did not observe any adverse events to be included in the meta-analysis and contribute valuable data. These advantages increased the relevance and improved the quality of our results, and strengthened the validity of the conclusions.On the other hand, several limitations should be noted. First of all, only 16 studies that specifically reported irAEs were included in this report, and the remaining 10 studies only reported trAEs or did not further clarify the incidence of any grade and high-grade irAEs. This low proportion may be due to the need for a clear definition of irAE and the corresponding difficulty in diagnosing irAEs. Indeed, certain adverse events, such as colitis, can occur because of a non-immune drug response. Therefore, there is an urgent need to publish a standardized method that specifies quantifiable criteria for irAEs and non-irAEs. The irAEs described in this study include those that were directly described in the included clinical trials as well as select adverse events and adverse events of special interest based on a prespecified list of terms from the Medical Dictionary for Regulatory Activities . SecondlWider applications of an increasing number of new irAEs are being recognized. A thorough understanding of the pathogenesis and pathologic features of these adverse reactions can help to clarify the definition of irAEs and to establish a predictive system to reduce morbidity. At present, management guidelines for irAEs are gradually being established. Timely and effective treatment of irAEs is necessary to improve patient compliance and guide decision-making for interruption of immunotherapy. More in-depth clinical studies are required to identify biomarkers that are useful predictors of both treatment efficacy and adverse effects and thereby allow specialists to determine the optimal balance for effective oncology treatment.Additional file 1:Table S1. Search strategy for PubMed. (DOCX 18 kb)Additional file 2:Reference list of all excluded studies. (DOCX 81 kb)Additional file 3:Figure S1. to Figure S2. Global irAEs  associated with anti-PD-1 and anti-PD-L1 drugs. Figure S3. to Figure S4. Global irAEs  associated with pembrolizumab and durvalumab. Figure S5 to Figure S43. Organ-specific  irAEs  associated with anti-PD-1 and anti-PD-L1, anti-PD-1, nivolumab, pembrolizumab, anti-PD-L1, atezolizumab, and durvalumab at all dosages. Figure S44. Death related to irAEs. (DOCX 9781 kb)Additional file 4:Table S2. General characteristics of patients receiving anti-PD-1/anti-PD-L1 antibodies, as described in case reports (n = 35). Table S3. Organ-specific immune-related adverse events. (DOCX 32 kb)Additional file 5:Table S4. The Cochrane Collaboration’s tool for assessing risk of bias of RCTs. Table S5. Newcastle–Ottawa Scale (NOS) for quality assessment of non-RCTs. (DOCX 43 kb)Additional file 6:Figure S45. Qualitative and quantitative assessment of small-study effects on incidence of global irAEs with anti-PD-1 and anti-PD-L1. (DOCX 93 kb)


Streptococcus, Pseudobutyrivibrio, and Anaerorhabdus. The translocation of lung microbiome was shown that 32.84% of them were from oral. After analysis of gene function, ABC transporter systems, biofilm formation, and two-component regulatory system were enriched in IPF patients' microbiome. Here we shown the microbiology characteristics in IPF patients. The microbiome may participate in altering internal conditions and involving in generating antibiotic resistance in IPF patients.Lung microbiome ecosystem homeostasis in idiopathic pulmonary fibrosis (IPF) remains uncharacterized. The aims of this study were to identify unique microbial signatures of the lung microbiome and analyze microbial gene function in IPF patients. DNA isolated from BALF samples was obtained for high-throughput gene sequencing. Microbial metagenomic data were used for principal component analysis (PCA) and analyzed at different taxonomic levels. Shotgun metagenomic data were annotated using the KEGG database and were analyzed for functional and metabolic pathways. In this study, 17 IPF patients and 38 healthy subjects (smokers and non-smokers) were recruited. For the PCA, the first and the second principal component explained 16.3 and 13.4% of the overall variability, respectively. The β diversity of microbiome was reduced in the IPF group. Signature of IPF's microbes was enriched of  Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal disease without a known cause  samples obtained from the lower respiratory tract are used for routine diagnostic procedures. BALF sampling is suitable for the identification of a distinct microbiome in the lower respiratory tract  and gut. We attempted to assess the usefulness of shotgun metagenomics applied directly to DNA extracted from BALF samples to characterize the lung microbiomes in IPF and healthy patients and to reveal the role of the microbiome in IPF pathophysiology.A diagnosis of IPF was made after multidisciplinary consultations. Only individuals diagnosed according to the international guidelines of the American Thoracic Society (ATS) and the European Respiratory Society (ERS) were subsequently included in this study  were performed according to ATS guidelines via the oropharyngeal route in accordance with a standard operating procedure, during which 20 ml of normal saline was instilled into a designated segment of the lobe showed in DNA was extracted from 3.0 ml of each original BALF sample using a QIAamp DNA Microbiome Kit  in strict accordance with the manufacturer's instructions. The DNA concentration was measured using a Qubit® 2.0 Fluorimeter .Q < 13). This produced an average of 8.5 gigabases (Gb) of high-quality sequences for each sample, resulting in a total of 470 Gb of sequence data  or single-end sequencing on 100 bp. The base-calling pipeline was used to process raw fluorescent images and to call sequences. Reads that mapped to the human genome (hg19) were removed from each sample with BWA MEM using the default parameter , and if it potentially aligned with U unique reads and M multiple reads, the following formulae were used:pi denoting the proportion in group k.Shannon diversity index (H) at the species level was calculated as the following, with i, the number of read pairs that aligned to it divided by the length of the gene was calculated as Num_Gi, and the relative abundance, RNum_Gi, of each gene in each sample (n genes) was computed using the following formula:Gene abundance was determined using a method similar to RPKM (reads per kilobases per million reads) used to quantify gene expression based on RNA sequencing data. In brief, high-quality original Illumina reads from each sample were aligned with a reference gene set using BWA. For each gene, Ge-value 1e-5.” Genes that had alignments with a score slightly higher than 60 were assigned into one or more eggnog or KEGG ortholog groups. We used the methods introduced in previous study . Then, antibiotic resistance gene abundance was determined as mentioned above. We used the Wilcoxon rank sum test to determine significantly different abundances between conditions. Virulence factors (VFs) were analyzed using a similar strategy. In brief, all VFs were identified using the VFDB database . Gene abundances and related statistical analysis were followed the ARGs' method.Antibiotic resistance genes (ARGs) were annotated using the ARDB . Pairwise comparisons were performed in ANOSIM, and pairwise P-values were corrected for multiple testing with the Benjamin & Hochberg method using R software Version 3.1.1 (http://www.r-project.org/).PCA was analyzed using QIIME (Version 1.9.1)  and 38 healthy control subjects  were included according to the inclusion criteria. The demographic data for these subjects are summarized in To identify any differences in the organismal structure of the lung microbiota, principal component anlaysis was performed based on taxonomic profiles at the species level . DiffereFirmicutes  and Fusobacterium  dominated the BALF microbial communities in both groups  but higher levels of Proteobacteria  and Fusobacteria . At the genus level  than the healthy subjects.Sequencing reads  were aligned against 3,096 reference genomes from the National Center for Biotechnology Information and the HMP reference sequence, which contains 131 archaeal strains comprising 97 species, 326 lower eukaryotes comprising 326 species, 3,683 viral strains comprising 1,420 species, and 1,751 bacterial strains comprising 1,253 species . Relativh groups . Compareus level , BacteroP-value = 0.01) in the IPF group compared with that in the smoking/non-smoking groups according to the ADONIS results. A similar grouping pattern was identified based on the Bray-Curtis matrix using hclust2 .To measure the diversity of the BALF communities in IPF patients and healthy subjects (including smokers and non-smokers), we employed various methods, such as Adonis and ANOSIM of QIIME, to evaluate differences (beta-diversity) in the lung microbiota among the groups. BALF biodiversity was significantly reduced  databases. We compared annotated genes with the reference database to determine functional gene sources. According to our results, the majority of genes were shared, 32.84% genes were derived from oral, and 1.32% genes were derived from the gut, as determined by V search (see the Methods section for details) and the results were shown in To explore the origins of the lung microbiome, we constructed a reference gene catalog based on the HOMD and HMP , vitamin biosynthesis, biotin metabolism, and amino sugar and nucleotide sugar metabolism were enriched in the IPF group  and IPF patients, shotgun metagenomics data were annotated using the KEGG and eggNOG database and analyzed for functional and metabolic pathways , 4. A toPF group . Among tPF group . Multidraterials . At the The Human Microbiome Project was launched in 2007 to study the microbial inhabitants of the human body and the microbes that live on human mucosal surfaces with the understanding that human biology may partially depend on interactions with these microorganisms , and the most common pathogenic viruses were microvirus, simplex virus and varicella virus. The same results had been reported with an increased bacterial load and decreased microbial diversity in BAL samples from IPF patients  compared to healthy subjects, which was also proven in our study. The bacterial load affects survival in these patients whereas retrospective analysis of the lung microbiome in BAL samples from the COMET-cohort suggested that presence of specific Streptococcus operational taxonomic units (OTU) or Staphylococcus OTU was associated with worse outcomes of IPF. These studies were showed the differential microbiome and specific microbial genes changes in BALF isolated from IPF patients, which suggested microbiota-targeted biomarkers may be potential tools for disease diagnosis and predicting prognosis. Biodiversity analysis revealed greater microbiome diversity associated with better lung function in the control group; conversely, the IPF group demonstrated decreased microbial diversity in terms of bacterial gene richness. Analysis of BALF microbiome revealed the appearance of common oral and gut inhabitants in BALF. Notably, shifts in the bacterial make-up of the BALF were associated with the human gut and oral microbiotas. In the IPF group, the majority of inhabitants were derived from the oral microbiome, suggesting they shifted from the mouth and throat. Comparison of BALF microbial genes to oral and gut microbiomes demonstrated that majority genes were from oral source, which hint the potential mechanism of oral aspiration as a risk factor in pathogenesis of IPF.In our current study, bacteria and virus microbial genes discriminated between IPF patient BALF and the BALF of healthy individuals with a high specificity; for example, This study provides an opportunity to identify the bacterial functions required for a bacterium to thrive in the context of the BALF from IPF group and healthy subjects. To identify the functions of the BALF genome, gene length and copy number were normalized, and the relative frequencies of different functions were deduced based on the number of genes recruited to different EggNOG clusters. ABC transporter systems, the two-component regulatory system, biofilm formation, amino acid and vitamin biosynthesis, and central carbon metabolism were enriched in the IPF group. Not surprisingly, projection of the range clusters in KEGG metabolic pathways provided highly explicit directions associated with antimicrobial resistance. Antimicrobial resistance is a natural response of bacteria to antibiotic exposure  Co., Ltd, Beijing, the People's Republic of China. The remaining 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.


Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is a severe condition with limited treatment strategies. Although respiratory infection is a major cause of AE-IPF, no reports have indicated pertussis infection as a cause. Here we report two cases of pertussis infection-induced AE-IPF.Both patients presented with a chief complaint of acute respiratory distress and were previously diagnosed with idiopathic pulmonary fibrosis (IPF). Neither patient had received any pertussis vaccination since adolescence. Both patients were diagnosed with AE-IPF accompanying acute pertussis infection based on chest computed tomography and serum pertussis toxin antibody > 100 EU/mL. Both patients were treated with macrolide antibiotics and systemic corticosteroids. Both patients were able to be discharged and return home.The presence of pertussis infection in AE-IPF can present a diagnostic challenge, as coughing accompanying pertussis may be difficult to distinguish from IPF-associated coughing. Pertussis infection should be assayed in AE-IPF patients. Since pertussis can be prevented with vaccination and is expected to be affected by antibiotics, consideration of pertussis infection as a causative virulent factor of AE-IPF may be important for management of subjects with IPF. Idiopathic pulmonary fibrosis (IPF) normally follows a chronic and progressive course. Respiratory failure that occurs during the course of this disease is known as acute exacerbation of IPF (AE-IPF), which may be caused by infection . The majCase 1: The patient was a 69-year-old man who was diagnosed with IPF 5 years prior to the current episode. He complained of respiratory distress during exertion and dry cough without any treatment. Physical examination revealed bilateral fine crackles in the lung. The patient was admitted to our hospital because of a sudden worsening of his respiratory distress and was diagnosed with AE-IPF based on a poor blood oxygen concentration and the observation of new ground-glass opacity findings over a broad range of bilateral lung fields during computed tomography (CT) scanning  were not observed in either patient, no infectious diseases other than pertussis were detected through sputum culture tests or serum markers. No other causative bacteria were detected in urine antigen tests or sputum culture tests. Moreover, heart failure was not observed in either patient. Both patients were treated with macrolides and broad-spectrum β-lactam antibiotics, accompanied by high-dose corticosteroid therapy. Case 1 involved an initial acute exacerbation and Case 2 involved a recurrent acute exacerbation.Neither patient had received any pertussis vaccination since adolescence. As both exhibited a typical usual interstitial pneumonia pattern on high-resolution CT, they were both clinically diagnosed with IPF. No blood test exams or physical findings showed any sign of autoimmune disease. Both patients reported a chronic cough associated with the IPF, but they had been aware of uncontrolled cough deterioration and continuous cough beginning approximately 3 weeks before hospitalization. Neither patient had The current report described cases that demonstrated infection with pertussis as a cause of AE-IPF. Infection is now considered to be a major causative factor leading to AE-IPF . While vThe current case report revealed three major findings. The first finding was that consideration of pertussis infection should be noted as part of the differential diagnosis during AE-IPF. Many physicians mistakenly consider pertussis to solely present as a pediatric infection; however, recent publications have shown that pertussis is now common among adults and is often overlooked by internists . AdditioThe second finding was the anticipated efficacy of treatment with macrolide antibiotics. Although further discussion may be necessary, macrolide antibiotic treatment can sometimes reduce the duration or severity of symptoms in pertussis infection . When a Lastly, most bacterial infections of the respiratory tract are not preventable; however, pertussis is one of the few pathogens that is preventable through vaccination. Pertussis vaccination is now recommended in a wide array of developed countries . VaccinaPertussis infection was diagnosed based on serological testing in our current cases; notably, the serological diagnostic method was validated in multiple previous reports. The major diagnostic criterion of recent or current active pertussis infection is a PT antibody level > 100 EU/mL at any time point; both of our cases met this criterion –11. PrevAlthough widespread adoption of the pertussis vaccine has resulted in a dramatic decrease in the number of affected patients, recent reports of increasing numbers of pertussis cases in various countries around the world are attracting attention . Thus, sBordetella pertussis is known to damage bronchial epithelial cells, thereby inducing inflammatory cytokines and chemokines. PT, adenylate cyclase (ACT), tracheal cytotoxin (TCT), and Bordetella dermonecrotic toxin are involved in the pathogenesis of pertussis through the attachment of the bacteria to bronchial mucosal epithelial cells. The presence of TCT induces the production of tumor necrotizing factor alpha, interleukin-6, and IL-1β from bronchial epithelial cells [B. pertussis produces toxins, PT and ACT, that inhibit the phagocytic activity of macrophages in a manner that is distinct, compared with other bacterial pathogens [The mechanism by which pertussis infection induces AE-IPF is currently unclear. The causative al cells . ACT conal cells ; moreoveathogens , 17.To our knowledge, this is the first report that acute pertussis infection, a vaccine-preventable and often overlooked infection that is treatable with macrolide, could cause AE-IPF. To epidemiologically investigate the extent to which pertussis is involved in AE-IPF, it is necessary to consider serological and culture examination methods, as well as examination by PCR, which shows high sensitivity. This additional method is needed because the specificity of pertussis is high with serological and culture examination methods, but the corresponding detection rates are low. Further research regarding the relationship between pertussis infection and AE-IPF is critical in the future.