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Leuco dye-based thermochromic materials offer enormous potential for visible molecular logic due to the appealing reversible color-changing effect. The stable color state is uncontrollable as it depends only on the spontaneous protonation of the leuco dye and color developer. There is still a challenge to propose an effective approach to control bistable color function at required temperature. A family of azobenzenes with various alkyl chains (AZO(n)) is designed for protonation competition with leuco dye. The hydrogen bond and Van der Waals forces are formed between color developer and AZO(n). The color developer can be locked to provide the proton for the leuco dye by Z-AZO(n), while it can be released upon Z-to-E photoisomerization. The locked state can be lasted for more than 16â hours. This optically controlled leuco dye-based system demonstrates a visible sequential logic operation with four-input signals, and provides a new type of protonation-based optical control.
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Optically active polymers are promising multifunctional materials with great application potentials. Herein, environmentally friendly optically active polyurethanes (OPUs) were obtained by introducing rotatory binaphthol monomer to polyurethane. The influence of binaphthol monomer content on the structure, mechanical properties, infrared emissivity, and thermal insulation of OPUs was studied intensively. Structure characterization indicated that the optically active polyurethanes have been successfully synthesized. The OPU synthesized with BIMOL and BDO at the mole ratio of 1:1 presented better thermal resistance. In addition, OPUs showed enhanced tensile strength and stretchability with the increase of BINOL content to a certain extent due to its rigid structural features and high molecular weight. The optically active polyurethanes showed lower infrared emissivity values (8-14 µm) than waterborne polyurethane (WPU), and the infrared emissivity decreased from 0.850 to 0.572 as the content of the BINOL monomer increased. Moreover, OPU4 exhibited the best heat insulation and cooling ability with about a 7 °C temperature difference. The thus-synthesized optically active polyurethanes provide an effective solution for developing highly effective thermal insulation materials.
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Stimuli-responsive supramolecular assemblies controlling macroscopic transformations with high structural fluidity, i.e., foam properties, have attractive prospects for applications in soft materials ranging from biomedical systems to industrial processes, e.g., textile coloring. However, identifying the key processes for the amplification of molecular motion to a macroscopic level response is of fundamental importance for exerting the full potential of macroscopic structural transformations by external stimuli. Herein, we demonstrate the control of dynamic supramolecular assemblies in aqueous media and as a consequence their macroscopic foam properties, e.g., foamability and foam stability, by large geometrical transformations of dual light/heat stimuli-responsive molecular motor amphiphiles. Detailed insight into the reversible photoisomerization and thermal helix inversion at the molecular level, supramolecular assembly transformations at the microscopic level, and the stimuli-responsive foam properties at the macroscopic level, as determined by UV-vis absorption and NMR spectroscopies, electron microscopy, and foamability and in situ surface tension measurements, is presented. By selective use of external stimuli, e.g., light or heat, multiple states and properties of macroscopic foams can be controlled with very dilute aqueous solutions of the motor amphiphiles (0.2 weight%), demonstrating the potential of multiple stimuli-responsive supramolecular systems based on an identical molecular amphiphile and providing opportunities for future soft materials.
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A novel raspberry-shaped thermochromic energy storage nanocapsule (RTESN) is successfully designed and fabricated with switchable sunlight absorption capacity based on color change for temperature regulation. The RTESN is developed by grafting amino-modified silica shell thermochromic nanoparticles (amino-TLD@SiO2 ) on the surface of epoxy-functionalized energy storage nanocapsules (paraffin@PSG), with a total particle size about 450 nm. RTESN exhibits a deep color under low temperatures, which can absorb sunlight for heating. During the continuous thermal energy supply, paraffin@PSG is capable of storing thermal energy owing to its large latent heat capacity of 118.7 J g-1 , thereby maintaining the slow temperature increase. When the temperature is higher than the phase change temperature of paraffin@PSG, the color of amino-TLD@SiO2 turns to white with more reflection of sunlight so that it reduces the absorption of thermal energy and prevents the further increase of temperature. The thermal regulation behavior is confirmed by setting up a wooden house with the surface covered with RTESN. Compared with the blank wooden house, the RTESN covered wooden house (RTESN-H) displays thermal insulation performances during heating and cooling with a maximum temperature difference of 7 °C.
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The controllability of foam stability is a vital feature that allows for practical applications of foam systems. Light, as an external stimulus, offers unique opportunities to tune the foam stability in a non-invasive manner with high spatiotemporal precision. However, most of the reported photoresposive foams were generated from ionic type surfactants, limiting their applications in industrial complex systems with multiple components. Herein, we design and synthesize a series of nonionic azobenzene surfactants with different polyoxyethylene glycol (EO) chain lengths (BEO-n-Azo, n, referring to the EO chain length, is 14, 19 and 23, respectively) to prepare photoresponsive foams. Detailed insights into the effects of EO chain length on photoisomerization properties, surface tension, as well as foamability and controllable stability of photoresponsive foams are presented. The results demonstrate that photoresposive foams are generated not only from single-component solutions of BEO-n-Azo, but also from multiple-component complex systems doped with BEO-n-Azo, providing a promising strategy to broaden applications of photoresponsive foams in industrial processes.
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Thermochromic dyes (TCDs) based on a three-component color change system suffer from solid rigidity and liquid leakage issues because of the intrinsic solid-liquid phase change performance, resulting in difficulty in temperature visualization applications for smart wearable fields. Despite considerable efforts in microencapsulation of thermochromic dyes, designing and fabricating essentially flexible thermochromic phase change films still need to be explored. Herein, a one-sided adhesive gradient-crosslinked thermochromic film is reported to address these issues to make a trade-off between stability and flexibility, excellent thermochromic performance, and temperature visualization. The thermochromic wearable films have been fabricated exploiting tea polyphenol thermochromic dyes, vinyl dimethylsiloxane, and hydrosilicone oil via the salt-template-assisted method and gradient crosslinking strategy, which have porous structures with an average pore size of 12.8 µm and a porosity of 28 %. Due to the spatial limiting threshold effect of the porosity structure, interconnected 3D polysiloxane porous networks can provide ample support for tea polyphenol thermochromic dyes and effectively prevent liquid leakage. Upon heating, the thermochromic film changes from blue to white with the K/S value decreasing from 7.69 to 0.78 and the ΔE* increasing from 2.7 to 16.1 at 610 nm, and the color-changing temperature is 42 °C. Gradient crosslinked thermochromic films exhibit excellent temperature-responsive color change properties, desirable one-side adhesion, and thermal energy storage, enabling multicolor temperature displays and temperature-controlled multilevel information transfer.
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Photonic crystals (PCs) possess unique photonic band gap properties that can be used in the field of sensors and smart displays if modulated on the micronano structure. Both nonclose-packed (NCP) structure and high refractive index (RI) contrast of PC play important roles in response sensitivity during stretching. Herein, we constructed an NCP-structured PC strain sensor with high RI by a novel coating-etching strategy. Stretch-induced changes in structural color correspond to the strength of the force, enabling the detection of the strength of the acting force by the naked eye. The flexible 3D cross-linked network constructed by poly(ethylene glycol) phenyl ether acrylate and pentaerythritol tetrakis(3-mercaptopropionate) endows the sensor with excellent elasticity and robustness. The designed PC strain sensor achieves high mechanochromic sensitivity (â¼8.3 nm/%, 0.02 to 4.21 MPa) and a substantial reflection peak shift (Δλ = 249 nm). More importantly, the high RI contrast (Δn = 0.43) between CdS and polymers imparts isotropic optical properties, ensuring a broad viewing angle while avoiding misleading signals. The research provides a novel fabrication strategy to construct sensitive PC strain sensors, expanding the prospective applicability to human movement monitoring and secure message encryption.
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Mechanoluminescent (ML) materials can emit visible light by utilizing mechanical energy, which shows unique advantages in visual mechanical sensing, displays, and biomechanical monitoring due to the correlation between force stimulation and luminescence intensity. Most organic ML materials exhibit luminescence intensity attenuation, disappearing completely with force stimulation and failing to recover. Here, organic luminogens (Cz-alkyl6) can be synthesized by introducing a soft alkyl chain into the carbazole, which exhibits ML emission with self-assembly units. Furthermore, organic luminogens can be generated repeatedly by simply recrystallizing the fracture crystal in situ after a short thermal treatment (70 °C) within 14 s. More importantly, the quantitative correlation between force pressure and ML intensity has been established by a sandwich-type ML device based on a novel carbazole derivative (Cz-alkyl6). The ML device presents a capacity for detecting mechanical signals up to 13 N according to its ML intensity (≤275 a.u.), exhibiting potential application value in engineering damage detection, anticounterfeiting, and advanced visual mechanical sensing.
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Molecular solar thermal (MOST) materials, which can efficiently capture solar energy and release it as heat on demand, are promising candidates for future personal thermal management (PTM) applications, preferably in the form of fabrics. However, developing MOST fabrics with high energy-storage capacity and stable working performance remains a significant challenge because of the low energy density of the molecular materials and their leakage from the fabric. Here, an efficient and robust MOST fabric for PTM using azopyrazole-containing microcapsules with a deep-UV-filter shell is reported. The MOST fabric, which can co-harvest solar and thermal energy, achieves efficient photocharging and photo-discharging (>90% photoconversion), a high energy density of 2.5 kJ m-2 , and long-term storage sustainability at month scale. Moreover, it can undergo multiple cycles of washing, rubbing, and recharging without significant loss of energy-storage capacity. This MOST microcapsule strategy is easily used for the scalable production of a MOST fabric for solar thermal moxibustion. This achievement offers a promising route for the application of wearable MOST materials with high energy-storage performance and robustness in PTM.
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The development of wearable devices has stimulated significant engineering and technologies of textile electronics (TEs). Improving sensing, energy-storing, and electro-heating capabilities of TEs is still challenging but crucial for their practical applications. Herein, a drip-coating method that constructs a dense ß-FeOOH scaffold on a nylon strip for enhancing polypyrrole loading is proposed, which facilitates the fabrication of highly conductive and hydrophobic PFCNS (polypyrrole/ß-FeOOH/nylon strip). The space provided by the ß-FeOOH scaffold increases the mass of polypyrrole on fibers from 1.1 (polypyrrole/nylon strip) to 3.0 mg cm-2 (polypyrrole/ß-FeOOH/nylon strip), which decreases the resistance from 104.96 to 34.29 Ω cm-1. The PFCNS exhibits a linear elastic modulus of 0.758 MPa within 150% strain, performs a unique resistance variation mechanism, and enables great sensing capability with rapid response time (140 ms), long durability (10,000 stretching-recovering), and effective movement monitoring (e.g., breathing, back bending, jumping). The sensing signals for knee bending have been analyzed in detail by combining with both stretching and pressing response mechanisms. The PFCNS electrode attains a diffusion-controlled capacitance of 574 mF cm-2 and discharging-capacitance of 916 mF cm-2. Furthermore, an interdigitally parallel connection is proposed, which assists the PFCNS heater in achieving high temperature (84 °C) at a low voltage (4 V). This work provides a simple route for nylon-based TEs and promises satisfactory application in wearable sensors, power sources, and heaters.
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By designing and preparing multifunctional materials exhibiting self-healing ability, problems related to their durability outdoors can be solved. This study, inspired by the self-healing mechanism of natural creatures, successfully prepared a dual self-healing multifunctional coating using temperature stimuli-responsive multicompartment microcapsules. Phase change materials (PCMs) were employed to load multicompartment microcapsules that were produced through Pickering emulsion polymerization by applying hydrophobic materials encapsulated by titanium dioxide (TiO2) nanocapsules as Pickering emulsifiers. The multifunctional coating produced using microcapsules and self-healing waterborne polyurethane (WPU) exhibited thermal insulation and antireflection properties, which was attributed to the application of PCMs and TiO2, and it also achieved remarkable superhydrophobicity. Moreover, this coating exhibited the intrinsic and superficial dual self-healing ability, which was attributed to the release of hydrophobic materials from microcapsules and the self-healing ability of WPU. This study can be referenced to guide the fabrication of high-performance self-healing materials, and it can contribute to the long-term use of multifunctional coatings.
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A durable and reversible acid-induced discoloration azobenzene UV-curable lignin-based waterborne polyurethane polymeric dye (EDA-ULPD) is prepared from lignin, azobenzene and pentaerythritol triacrylate(PETA) by chemical modification of waterborne polyurethane. Lignin and PETA are chemically bonded to the polyurethane chain to improve thermal stability, UV resistance and color fastness, while also endow the polymeric dye with UV curing performance, which is a green and environmentally friendly fixing way. The acid-induced discoloration property of EDA-ULPD with azobenzene chromophore side chain is comparable to those of 4-ethyl-4-2,2'-dihydroxy diethylamine azobenzene (EDA). As the pH value decreases from 7 to 1, the maximum absorption peak of EDA-ULPD from 420 nm to 530 nm, and the color change from yellow to pink due to the transformation of EDA molecular structure from diazo to hydrazone. Interestingly, when EDA-ULPD is fixed to the fabric in the way of UV curing, its printed fabric exhibits the performance of high concentration acid-induced discoloration (1 mol·L-1 HCl) due to the cross-linked structure formed by EDA-ULPD. The acid-induced discoloration property of EDA-ULPD printed fabrics also presents outstanding repetitious stability. The stimulus response printed fabric with reversible high concentration acid discoloration possesses a broad application prospect in smart textiles.
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Ácidos/química , Compuestos Azo/química , Colorantes/química , Lignina/química , Polímeros/química , Poliuretanos/química , Rayos Ultravioleta , Agua/química , Compuestos Azo/síntesis química , Rastreo Diferencial de Calorimetría , Color , Colorantes/síntesis química , Reactivos de Enlaces Cruzados/química , Peso Molecular , Polímeros/síntesis química , Espectroscopía de Protones por Resonancia Magnética , Espectrofotometría Infrarroja , TemperaturaRESUMEN
The trends of wearable health monitoring systems have led to growing demands for gait-capturing devices. However, comfortability and durability under repeated stress are still challenging to achieve in existing sensor-enabled footwear. Herein, a flexible textile piezoresistive sensor (TPRS) consisting of a reduced graphene oxide (rGO)-cotton) fabric electrode and an Ag fabric circuit electrode is proposed. Based on the mechanical and electrical properties of the two fabric electrodes, the TPRS exhibits superior sensing performance, with a high sensitivity of 3.96 kPa-1 in the lower pressure range of 0-36 kPa, wide force range (0-100 kPa), fast response time (170 ms), remarkable durability stability (1000 cycles) and detection ability in different pressures ranges. For the prac-tical application of capturing plantar pressure, six TPRSs were mounted on a flexible printed circuit board and integrated into an insole. The dynamic plantar pressure distribution during walking was derived in the form of pressure maps. The proposed fully-textile piezoresistive sensor is a strong candidate for next-generation plantar pressure wearable monitoring devices.
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A sensitive electro-thermochromic Janus fabric driven by voltage is demonstrated via a facial double side coating. The graphene forms a conductive layer that allows Joule heating to supply the thermal resource for the electro-thermochromic behavior of polyester fabric. The thermochromic dye with reversible color-changing property is coated on the opposite side of the graphene layer. The color of electro-thermochromic Janus fabric changes from blue to white with a gradual heating that exceeded 45 °C at the applied voltage of 10 V. The switching rate of color is rapid with the increase of temperature from the room temperature to above 45 °C in 8 s, resulting from the superior resistive heating of the graphene. The electrical conductivity of the electro-thermochromic Janus fabric is not disturbed once undergoing a bending angle range from 30° to 150° and the temperature remains stable after 1000 bending cycles which clearly indicates the excellent flexibility of the fabric. The steady signal in the heating/cooling curve is observed after 500 cycles, pointing out the outstanding durability of the electro-thermochromic Janus fabric under the supplied voltage. It is realizable that the color of electro-thermochromic Janus fabric is triggered accurately by varying the supplied voltage. The simplicity of this design makes it attractive for the application of flexible electro-thermochromic textile, such as active visual camouflage, personal thermal management, and information displays.
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The synthesis of multifunctional microcapsules using natural polymers has contributed to a broad range of practical applications on fabric coatings. This paper presents a facile and environment-friendly approach for waterborne multifunctional fabric coatings by using cellulose/silica hybrid microcapsules. In this method, lavender fragrance oil-loaded cellulose/silica hybrid microcapsules were one-step synthesized via emulsion solvent diffusion. This microcapsule is core-shell structure with UV absorbers and methacrylic acid grafted silica in the shell and then added into the waterborne polysiloxane resins to form multifunctional fabric coatings. The as-obtained fabric coatings not only exhibited controlled lavender fragrance oil-releasing performance, and it can keep above 30 % fragrance after ninety days due to the slow releasing of lavender fragrance oil in the capsules, but also showed excellent UV resistant property with 159 UPF value.
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Beauveria bassiana, Cordyceps militaris and Ophiocordyceps sinensis (Ascomycotina) are traditional Chinese medicines. Here, mitogenomes of these three Ascomycotina fungi were sequenced and de-novo assembled using single-molecule real-time sequencing. The results showed that their complete mitogenomes were 31,258, 31,854 and 157,584 bp, respectively, with sequencing depth approximately 278,760×, 326,283× and 69,385×. Types of repeat sequences were mainly (AA)n, (AAT)n, (TA)n and (TATT)n. DNA methylation motifs were revealed in DNA modifications of these three fungi. We discovered new models of RNA editing through analysis of transcriptomes from B. bassiana and C. militaris. These data lay a solid foundation for further genetic and biological studies about these three fungi, especially for elucidating the mitogenome evolution and exploring the regulatory mechanism of adapting environment.
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Aclimatación/genética , Beauveria/genética , Cordyceps/genética , Metilación de ADN/genética , Genoma Mitocondrial/genética , Edición de ARN/genética , Aclimatación/fisiología , Perfilación de la Expresión Génica , Variación Genética/genética , Medicina Tradicional China , Transcriptoma/genéticaRESUMEN
High water absorption aerogels with three-dimensional porous structures and high specific surface areas have been fabricated from methoxy polyethylene glycolpolycaprolactone block copolymer (mPEGPCL) via a facile approach by electrospinning, mechanical homogeneous shearing and dispersing short fibers in the water, freeze-drying, and heat crosslinking. The three-dimensional nanofiber aerogels (TNAs) exhibit continuous porous structures which are restructured with crisscrossed and dispersed nanofibers. The aerogel displays a low density (36⯱â¯3â¯mg/cm3), a high specific surface area (230â¯m2/g), a high pore volume (5.9â¯cm3/g), a high porosity of 85% as well as an average pore diameter (1.12⯵m). The as-made mPEG-PCL TNAs deliver a high average water-absorption capacity of 24.11â¯g/g and a good retention ability owing to the three-dimensional porous structures and large micropores population. The water absorption could still reach approximately 25â¯g/g after 10 compression cycles of TNAs. The average dehydration weight loss of 3.1% demonstrates that the materials are hardly soluble in the water, and the structural characteristic would not be changed after water adsorption. The antimicrobial activity against the bacteria Staphylococcus aureus and Escherichia coli are assessed that the TNAs are suitable carriers of antimicrobial agents. Moreover, as showed by cytotoxic tests, the TNAs are neglectable toxic, which are suitable for applications in environmental bioengineering. Based on the high water absorption and biocompatibility, the TNAs could be suitable candidates for health care materials and medical products.
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Absorción Fisicoquímica , Geles/química , Nanofibras/química , Poliésteres/química , Polietilenglicoles/química , Agua/química , Animales , Antibacterianos/farmacología , Muerte Celular , Línea Celular , Escherichia coli/efectos de los fármacos , Ratones , Pruebas de Sensibilidad Microbiana , Nanofibras/ultraestructura , Espectroscopía Infrarroja por Transformada de Fourier , Staphylococcus aureus/efectos de los fármacos , Temperatura , HumectabilidadRESUMEN
A novel polyurethane elastomer (PUE) that exhibited high tensile strength, large elongation at break, great color strength and supreme color fastness was successfully designed and synthesized. The PUEs were prepared with isophorone diisocyanate (IPDI) as hard segments, polycarbonate diol (PCDL)/polytetrahydrofuran glycol (PTHF) as mixed soft segments, and anthraquinone chromogen as the chain extender agent. The relationships between the mechanical properties/color performance and chromogen addition content were investigated. The chromogen actual access rate of the obtained BPUEs was evaluated by UV-Vis. The clear tortuous surface and entanglements were exhibited in PUEs micromorphology structure, indicating a significant reinforcement of mechanical properties. Elongation-at-break and tensile strength reached the maximum value 2394% at 1% (BPUE1) and 18.29 MPa at 5% (BPUE5), respectively, and then decreased as chromogen addition content increased. Mechanical testing results correlate well with XRD and SEM findings, which proved that anthraquinone chromogen induced an improvement in phase separation. Furthermore, BPUE films displayed high color strength and excellent color fastnesses. The rubbing fastness and washing fastness of BPUE1 and BPUE0.5 reached grade 5, respectively. These inspiring findings suggest that PUE films with superb performance have potential to be directly applied in the textile field.
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Two-dimensional (2D) materials are a rapidly growing area of interest for wearable electronics, due to their flexible and unique electrical properties. All-textile-based wearable electronic components are key to enable future wearable electronics. Single component electrical elements have been demonstrated; however heterostructure-based assemblies, combining electrically conductive and dielectric textiles such as all-textile capacitors are currently missing. Here we demonstrate a superhydrophobic conducting fabric with a sheet resistance Rsâ¼ 2.16 kΩâ¡-1, and a pinhole-free dielectric fabric with a relative permittivity εrâ¼ 2.35 enabled by graphene and hexagonal boron nitride inks, respectively. The different fabrics are then integrated to engineer the first example of an all-textile-based capacitive heterostructure with an effective capacitance C â¼ 26 pF cm-2 and a flexibility of â¼1 cm bending radius. The capacitor sustains 20 cycles of repeated washing and more than 100 cycles of repeated bending. Finally, an AC low-pass filter with a cut-off frequency of â¼15 kHz is integrated by combining the conductive polyester and the capacitor. These results pave the way toward all-textile vertically integrated electronic devices.
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Textiles , Dispositivos Electrónicos Vestibles , Compuestos de Boro/química , Capacidad Eléctrica , Grafito/química , Nanoestructuras/química , Poliésteres/químicaRESUMEN
The complete genome of Cordyceps militaris was sequenced using single-molecule real-time (SMRT) sequencing technology at a coverage over 300×. The genome size was 32.57 Mb, and 14 contigs ranging from 0.35 to 4.58 Mb with an N50 of 2.86 Mb were assembled, including 4 contigs with telomeric sequences on both ends and an additional 8 contigs with telomeric sequences on either the 5' or 3' end. A methylome database of the genome was constructed using SMRT and m4C and m6A methylated nucleotides, and many unknown modification types were identified. The major m6A methylation motif is GA and GGAG, and the major m4C methylation motif is GC or CG/GC. In the C. militaris genome DNA, there were four types of methylated nucleotides that we confirmed using high-resolution LCMS-IT-TOF. Using PacBio Iso-Seq, a total of 31,133 complete cDNA sequences were obtained in the fruiting body. The conserved domains of the nontranscribed regions of the genome include TATA boxes, which are the initial regions of genome replication. There were 406 structural variants between the HN and CM01 strains, and there were 1,114 structural variants between the HN and ATCC strains.