Acute cardiac tamponade after Endostar treatment of non-small cell lung cancer: A case report.

RATIONALE: Recombinant human endostatin (Endostar) is extensively utilized in China for the clinical management of patients with driver gene-negative non-small cell lung cancer (NSCLC) at stage TNM IV. This report describes the case of a lung cancer patient treated exclusively with Endostar maintenance therapy, who experienced a rapid deterioration in respiratory function. PATIENT CONCERNS: The case involved a patient with a pathologically confirmed squamous cell carcinoma of the left lung, treated in our department. Following 1 month of albumin-bound paclitaxel chemotherapy and localized radiotherapy for the left lung lesion, the patient initiated treatment with a single agent, Endostar 30mg, on October 19, 2021. The medication was administered via intravenous infusion over a 7 days. DIAGNOSIS: On October 23, 2021, the patient exhibited symptoms of chest constriction, discomfort, coughing, and sputum production. By October 28, the patient presented with pronounced dyspnea and respiratory distress. An emergency CT scan detected pericardial tamponade and significant deviations in several blood parameters from pretreatment values. INTERVENTIONS: Percardial puncture and catheter drainage were recommended as therapeutic intervention. OUTCOMES: Considering the patient advanced age, the patient and their family opted to refuse this medical procedure, leading to the patient unfortunate demise on November 2, 2021. LESSONS: Medical professionals should remain vigilant for the potential, albeit rare, risk of Endostar inducing acute pericardial tamponade, a severe and potentially fatal complication.

Dual-functional Separators Regulating Ion Transport Enabled by 3D-Reinforced Polyimide Microspheres Protective Layer for Dendrite-Free and High-Temperature Lithium Metal Batteries.

High-energy-density lithium metal batteries (LMBs) are confronted with crucial concerns of security and a short cycle lifespan caused by the uncontrollable formation of lithium (Li) dendrites. The poor thermal stability and heterogeneous Li deposition of conventional polyolefin separators often cause battery short circuiting and thermal runaway in LMBs. Herein, a novel dual-functional PE composite separator (PI-COOH/PE) coated by carboxyl polyimide (PI) microspheres is fabricated by an etching-acidification method. The three-dimensional (3D) high-temp PI microsphere with rich carboxyl groups on the surface improve the security of LMBs at extremely high temperatures and facilitate the formation of a stable and uniform SEI layer, which contributes to accelerating the Li+ transport and stabilizing the formation of the SEI layer. Consequently, the Li symmetric cell assembled with the (PI-COOH)/PE separator exhibits stable overpotential over 3000 h, and the corresponding Li//NCM811 full cells also show a high-level discharge capacity of 146.6 mAh g-1 at 5 C. Meanwhile, it also demonstrates outstanding cycling stability and thermal safety, which can survive continuously over 160 min at 140 °C (vs 21 min for PE). The above results indicate the (PI-COOH)/PE separator constructed by a low-cost and industrial-friendly strategy simultaneously addresses high-temperature stability and dendrite resistance.

Improving Interfacial and Compressive Properties of Polyimide Fiber by Constructing Inorganic Layers on Fiber Surface.

The compressive performance of organic fiber has always been a key problem, limiting its development. In this paper, silicon oxide, alumina, and titanium oxide particles were separately deposited on the surface of high-strength and high-modulus polyimide (PI) fibers to form a structural supporting shell by using a magnetron sputtering method. The theoretical thickness was calculated by thermogravimetric analysis in good agreement with the actual thickness determined from scanning electron microscopy. The mechanics, surface, and interface properties of the measured fibers were analyzed mainly from the aspects of surface energy, interfacial shear strength (IFSS), and compression strength. The results showed that after magnetron sputtering, the inorganic shells were uniformly deposited on the surface of PI fiber, resulting in an increase in the content of inorganic elements as well as the roughness. As a result, the surface energy and IFSS of silica-coated fiber was increased by 174 and 85.6%, respectively, and compression strength was increased by 45.7%. This study provides a new approach for improving the interface property and compression strength of high-strength and high-modulus PI-fiber-reinforced composites.

Gut microbiota and cognitive performance: A bidirectional two-sample Mendelian randomization.

PURPOSE: Previous studies have suggested a potential association between gut microbiota and neurological and psychiatric disorders. However, the causal relationship between gut microbiota and cognitive performance remains uncertain. METHODS: A two-sample Mendelian randomization (MR) study used SNPs linked to gut microbiota (n = 18,340) and cognitive performance (n = 257,841) from recent GWAS data. Inverse-variance weighted (IVW), MR Egger, weighted median, simple mode, and weighted mode were employed. Heterogeneity was assessed via Cochran's Q test for IVW. Results were shown with funnel plots. Outliers were detected through leave-one-out method. MR-PRESSO and MR-Egger intercept tests were conducted to address horizontal pleiotropy influence. LIMITATIONS: Limited to European populations, generic level, and potential confounding factors. RESULTS: IVW analysis revealed detrimental effects on cognitive perfmance associated with the presence of genus Blautia (P = 0.013, 0.966[0.940-0.993]), Catenibacterium (P = 0.035, 0.977[0.956-0.998]), Oxalobacter (P = 0.043, 0.979[0.960-0.999]). Roseburia (P < 0.001, 0.935[0.906-0.965]), in particular, remained strongly negatively associated with cognitive performance after Bonferroni correction. Conversely, families including Bacteroidaceae (P = 0.043, 1.040[1.001-1.081]), Rikenellaceae (P = 0.047, 1.026[1.000-1.053]), along with genera including Paraprevotella (P = 0.044, 1.020[1.001-1.039]), Ruminococcus torques group (P = 0.016, 1.062[1.011-1.115]), Bacteroides (P = 0.043, 1.040[1.001-1.081]), Dialister (P = 0.027, 1.039[1.004-1.074]), Paraprevotella (P = 0.044, 1.020[1.001-1.039]) and Ruminococcaceae UCG003 (P = 0.007, 1.040[1.011-1.070]) had a protective effect on cognitive performance. CONCLUSIONS: Our results suggest that interventions targeting specific gut microbiota may offer a promising avenue for improving cognitive function in diseased populations. The practical application of these findings has the potential to enhance cognitive performance, thereby improving overall quality of life.

Sudden aortic dissection: A cautionary tale for the unexplained back pain during bevacizumab treatment.

Bevacizumab is widely used in the treatment of colorectal cancer, liver cancer, and other advanced solid tumors because of its multiple targets, no genetic testing and better safety. Globally, the use of bevacizumab in the clinic has been climbing year by year based on several large-scale, multicenter prospective studies. While bevacizumab undeniably has a good clinical safety profile, it has also been associated with adverse effects such as drug-related hypertension and anaphylaxis. In our recent clinical work, we met a female patient with acute aortic coarctation previously treated with multiple cycles of bevacizumab, who was admitted with sudden onset of back pain. Because the patient had just had an enhanced CT of the chest and abdomen a month earlier, no abnormal lesions apparently associated with low back pain were found. So when the patient was seen on this occasion, our clinical diagnosis was first considered to be neuropathic pain, but a further multiphase enhancement CT was done again for further exclusion and the final diagnosis was acute aortic dissection. The patient later died within 1 hour after the chest pain had worsened again while waiting for a surgical blood supply within 72 hours of presentation. The risk of fatal acute aortic dissection is not sufficiently emphasized in the revised instructions for bevacizumab, although the adverse effects associated with aortic dissection and aneurysm are mentioned. Our report is of high practical value in raising clinicians' vigilance and safe management of patients using bevacizumab worldwide.

Preparation and Interfacial Properties of Hydroxyl-Containing Polyimide Fibers.

Developing polyimide (PI) fibers with excellent interfacial adhesion and high mechanical properties for the PI fiber-reinforced polymer matrix composites (PFRPs) industry has been challenging. In this work, 4,4'-diamino-(1,1'-biphenyl)-3,3'-diol (HAB) diamine was introduced into the rigid molecular chains, and the high-performance PI fibers, presenting an interfacial shear strength (IFSS) value of 46.33 MPa, tensile strength of 2.62 GPa, and modulus of 100.15 GPa, were successfully manufactured when the content of HAB in mixed diamines was 30 mol %. Fourier transform infrared (FTIR) spectroscopy identified the presence of intermolecular H-bonding interactions, and 2D small-angle X-ray scattering indicated that the introduction of HAB moiety contributed to reducing the radii of microvoids in the fibers, which were considered to be the key factors leading to a significant enhancement in the mechanical properties of the fibers. X-ray photoelectron spectroscopy (XPS) and the static contact angle intuitively illustrated that the synthetic fiber surface contained active hydroxyl groups. The IFSS value of PI fiber/epoxy resin composites (PI/EPs) was 56.47 MPa when the content of HAB reached 70 mol %. Failure morphologies confirmed that the interfacial adhesion of PI/EPs was enhanced owing to the surface activity of PI fibers. Consequently, this study provides an effective strategy to the long-standing problems of high mechanical performances and poor surface activity for traditional PI fibers used in the PFRPs industry.

Effect of External Magnetic Field on Bulk Heterojunction Polymer Solar Cells.

Polymer solar cells (PSCs) with a bulk heterojunction (BHJ) device structure have incredible advantages, such as low-cost fabrication and flexibility. However, the power conversion efficiency (PCE) of BHJ PSCs needs to be further improved to realize their practical applications. In this study, boosted PCEs from PSCs based on BHJ composites incorporated with Fe3 O4 magnetic nanoparticles (MNPs), aligned by an external magnetic field (EMF), are reported. It is found that the coercive electric field within the Fe3 O4 MNPs generated by the EMF has a strong and positive influence on the charge generation, which results in a more than 10% increase in free charge carriers. Moreover, the coercive electric field speeds up the charge carrier transport and suppresses charge carrier recombination within PSCs. In addition, a shortened extraction time makes charge carriers more likely to make it to the electrodes. As a result, more than 15% enhancement in PCE is observed from the PSCs based on the BHJ composite incorporated with the Fe3 O4 MNPs and the EMF as compared with that based on the BHJ composite thin film. This work indicates that the incorporation of MNPs and the EMF is a facile way to enhance the PCEs of PSCs.

Thermostable and nonflammable polyimide/zirconia compound separator for lithium-ion batteries with superior electrochemical and safe properties.

Separators are applied to segregate cathode and anode, and provide ion transport channels in lithium-ion batteries (LIBs). Nevertheless, present commercial polyolefin separators represent high thermal shrinkage and inferior electrolyte wettability, seriously limiting wider development of LIBs. In this work, we prepared zirconia (ZrO2) nanolayer encapsulated polyimide (PI) nanofiber compound separator through in-situ polar adsorption and hydrolysis strategy. The obtained PI/ZrO2 compound separator has superior thermal stability, electrolyte wettability and flame retardance in comparison with polypropylene (PP) separator. The shrinkage ratio of prepared PI/ZrO2 compound separator is 0 even at 300 °C, while the PP separator significantly shrank at 160 °C. Furthermore, the ionic conductivity of PI/ZrO2 separator reaches up to 1.32 mS cm-1, far higher than 0.34 mS cm-1 of PP separator. Besides, the coin batteries of LiNi0.8Co0.1Mn0.1O2 (NCM811)/electrolyte-separator/lithium (Li) assembled with PI/ZrO2 compound separator exhibit enhanced rate performance, high discharge capacity retention rate of 88.3% after 100 cycles at 1C and excellent battery safety performance even at 140 °C. Thus, combined with its advantages, such as preparation, thermostability, electrolyte wettability, electrochemical property and safety, the PI/ZrO2 compound separator exhibits promising prospect in the application of commercial LIBs.

Construction of a miRNA-mRNA Network Related to Exosomes in Colon Cancer.

Background: The competing endogenous RNA (CeRNA) network plays important roles in the occurrence and development of colon cancer. This research is aimed at constructing a miRNA-mRNA network associated with exosomes in colon cancer. Methods: We explored the GEO database and then analyzed the RNAs of 722 samples to obtain differentially expressed miRNAs (DEMs) and mRNAs (DEGs) alongside the progress of colon cancer. Next, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of DEM target genes and DEGs were performed. In addition, a miRNA-mRNA network related to exosomes in colon cancer was constructed based on DEMs and DEGs. Finally, the expression of miRNA and mRNA in the network was verified by GEPIA2 on the base of TCGA database. Results: Through our analysis, 19 DEMs (17 up and 2 down) and 1672 DEGs (954 up and 718 down) were screened. The GO and KEGG results show that these DEGs were mainly enriched in ribonucleoprotein complex biogenesis, noncoding RNA metabolic process, cell-substrate junction, cadherin binding, transcription coregulator activity, and regulation of the human T-cell leukemia virus 1 infection-related pathway. Besides, a miRNA-mRNA network, including 4 miRNAs (hsa-miR-623, hsa-miR-320c, hsa-miR-486-5p, and hsa-miR-1290) and 7 mRNAs (GNAI1, CADM1, PGRMC2, etc.), was constructed. Three of these seven mRNAs were downregulated in colon cancer. Ultimately, the GNAI1, CADM1, and PGRMC2 expression levels were verified by TCGA database. Conclusions: This study reveals the network relationship between colon cancer exosome-derived miRNA and targeted mRNA. It deepens our understanding of new molecular mechanisms and pathways that may play a role in the occurrence and metastasis of colon cancer.

Non-thermal plasma-assisted rapid hydrogenolysis of polystyrene to high yield ethylene.

The evergrowing plastic production and the caused concerns of plastic waste accumulation have stimulated the need for waste plastic chemical recycling/valorization. Current methods suffer from harsh reaction conditions and long reaction time. Herein we demonstrate a non-thermal plasma-assisted method for rapid hydrogenolysis of polystyrene (PS) at ambient temperature and atmospheric pressure, generating high yield (>40 wt%) of C1-C3 hydrocarbons and ethylene being the dominant gas product (Selectivity of ethylene, SC2H4 > 70%) within ~10 min. The fast reaction kinetics is attributed to highly active hydrogen plasma, which can effectively break bonds in polymer and initiate hydrogenolysis under mild condition. Efficient hydrogenolysis of post-consumer PS materials using this method is also demonstrated, suggesting a promising approach for fast retrieval of small molecular hydrocarbon modules from plastic materials as well as a good capability to process waste plastics in complicated conditions.

Configuration of Multifunctional Polyimide/Graphene/Fe3O4 Hybrid Aerogel-Based Phase-Change Composite Films for Electromagnetic and Infrared Bi-Stealth.

Electromagnetic (EM) and infrared (IR) stealth play an important role in the development of military technology and the defense industry. This study focused on developing a new type of multifunctional composite film based on polyimide (PI)/graphene/Fe3O4 hybrid aerogel and polyethylene glycol (PEG) as a phase change material (PCM) for EM and IR bi-stealth applications. The composite films were successfully fabricated by constructing a series of PI-based hybrid aerogels containing different contents of graphene nanosheets and Fe3O4 nanoparticles through prepolymerizaton, film casting, freeze-drying, and thermal imidization, followed by loading molten PEG through vacuum impregnation. The construction of PI/graphene/Fe3O4 hybrid aerogel films provides a robust, flexible, and microwave-absorption-functionalized support material for PEG. The resultant multifunctional composite films not only exhibit high microwave absorption effectiveness across a broad frequency range, but also show a good ability to implement thermal management and temperature regulation under a high latent-heat capacity of over 158 J/g. Most of all, the multifunctional composite films present a wideband absorption capability at 7.0-16.5 GHz and a minimum reflection loss of -38.5 dB. This results in excellent EM and IR bi-stealth performance through the effective wideband microwave absorption of graphene/Fe3O4 component and the thermal buffer of PEG. This study offers a new strategy for the design and development of high-performance and lightweight EM-IR bi-stealth materials to meet the requirement of stealth and camouflage applications in military equipment and defense engineering.

An Electrochemical Ethylamine/Acetonitrile Redox Method for Ambient Hydrogen Storage.

Hydrogen storage presents a major difficulty in the development of hydrogen economy. Herein, we report a new electrochemical ethylamine/acetonitrile redox method for hydrogen storage with an 8.9 wt % theoretical storage capacity under ambient conditions. This method exhibits low onset overpotentials of 0.19 V in CH3CH2NH2 dehydrogenation to CH3CN and 0.09 V in CH3CN hydrogenation to CH3CH2NH2 using commercial Pt black catalyst. By assembling a full cell that couples CH3CH2NH2/CH3CN redox reactions with hydrogen evolution and oxidation reactions, we demonstrate a complete hydrogen storage cycle at fast rates, with only 52.5 kJ/mol energy consumption for H2 uptake and release at a rate of 1 L/m2·h. This method provides a viable hydrogen storage strategy that meets the 2025 Department of Energy onboard hydrogen storage target.

High-Temperature-Induced Shape Memory Copolyimide.

A series of polyimide (PI) films with a high-temperature-induced shape memory effect and tunable properties were prepared via the facile random copolymerization of 4,4'-oxydianiline (ODA) with 4,4'-(hexafluoroisopropyl)diphthalic anhydride (6FDA) and 4,4'-oxydiphthalic anhydride (ODPA). The trigger temperature can be controlled from 294 to 326 °C by adjusting the ratio of monomers. The effects of monomer rigidity on the chain mobility, physical properties, and shape memory performance of as-prepared copolyimide were systematically investigated. The introduction of ODPA could enhance the mobility of PI macromolecular chains, which made chain entanglement more likely to occur and increased the physical crosslinking density, thereby improving the PI's shape recovery up to 97%. Meanwhile, the existence of 6FDA enabled PI films to set quickly at low temperatures with a shape fixation of 98%. The shape memory cycling characteristics of the polyimide films are also studied, and the relationship between the PI chemical structure and the film properties are further discussed.

Revealing the High-Modulus Mechanism of Polyimide Films Prepared with 3,4'-ODA.

To prepare PIs (polyimides) with desirable thermal and mechanical properties is highly demanded due to their widespread applications in flexible optoelectronic devices and printed circuit boards. Here, the PI films of BPDA/4,4'-ODA, BPDA/3,4'-ODA, PMDA/4,4'-ODA, PMDA/3,4'-ODA systems were prepared, and it was found that the PIs with 3,4'-ODA always exhibit a high modulus compared with the PIs with 4,4'-ODA. To disclose the mechanism of high-modulus PI films with 3,4'-ODA, amorphous PI models and uniaxial drawing PI models were established and calculated based on MD simulation. The PI structural deformations at different length scales, i.e., molecular chain cluster scale and repeat unit scale, under the same stress were detailed and analyzed, including the variation of chain conformation, bond length, bond angle, internal rotation energy, and torsion angle. The results indicate that PIs with 3,4-ODA have higher internal rotation energy and smaller deformation with the same stress, consistent with the high modulus.

Enhanced Impact Properties of Hybrid Composites Reinforced by Carbon Fiber and Polyimide Fiber.

A series of hybrid fiber-reinforced composites were prepared with polyimide fiber and carbon fiber as the reinforcement and epoxy resin as the matrix. The influence of stacking sequence on the Charpy impact and flexural properties of the composites as well as the failure modes were studied. The results showed that hybrid fiber-reinforced composites yielded nearly 50% increment in Charpy impact strength compared with the ones reinforced by carbon fiber. The flexural performance was significantly improved compared with those reinforced solely by polyimide fibers and was greatly affected by the stacking sequence. The specimens with compressive sides distributed with carbon fiber possessed higher flexural strength, while those holding a sandwich-like structure with carbon fiber filling between the outer layers displayed a higher flexural modulus.

Three-Dimensional Fluorescent Imaging to Identify Multi-Paths in Polymer Aging.

It is of great significance to disclose the diverse aging pathways for polymers under multiple factors, so as to predict and control the potential aging evolution. However, the current methods fail to distinguish multiple pathways (multi-paths) of polymer aging due to the lack of spatiotemporal resolution. In this work, using polyimide as a model polymer, the hydroxyl, carboxyl, and amino groups from the polyimide aging process were labeled using specific fluorescent probes through boron-oxygen, imine, and thiourea linkages, respectively. When the excitation and emission wavelengths of each fluorescent probe were controlled, the multi-paths in polyimide aging can be visualized individually and simultaneously in three-dimensional fluorescent images. The overall aging process under hydrothermal treatment was destructured into the pyrolysis and hydrolysis pathways. Three-dimensional dynamic studies discovered that the increased humidity, along with the decreased oxygen content, could hamper the pyrolysis reaction and accelerate the hydrolysis reaction, leading to severe degradation of the overall polyimide aging. More importantly, the oxygen showed a higher regulation coefficient in accelerating the pyrolysis reaction, than the water vapor in motivating the hydrolysis reactions. Such a multidimensional identification methodology is able to guide the long-term use of polymers and control their aging process to a harmless direction in advance by tuning the contents of oxygen and water vapor.

Effect of a "Zn Bridge" on the Consecutively Tunable Retention Characteristics of Volatile Random Access Memory Materials.

Polyimide memory materials with a donor-acceptor structure based on a charge-transfer mechanism exhibit great potential for next-generation information storage technology due to their outstanding high-temperature resistance and good dimensional and chemical stability. Precisely controlling memory performance by limited chemical decoration is one of core challenges in this field. Most reported work mainly focuses on designing novel and elaborate electron donors or acceptors for the expected memory behavior of polyimides; this takes a lot of time and is not always efficacious. Herein, we report a series of porphyrinated copolyimides coPI-Znx (x=5, 10, 20, 50, 80), where x represents the mole percentage of Zn ion in the central core of the porphyrin. Experimental and theoretical analysis indicate that the Zn ion could play a vital bridge role in promoting the formation and stabilization of a charge-transfer complex by enhancing the hybridization of local and charge transfer (HLCT) excitations of porphyrinated polyimides, endowing coPI-Znx with volatile random access memory performance and continuously tunable retention time. This work could provide one simple strategy to precisely regulate memory performance merely by altering the metal content in porphyrinated polyimides.

Fluorescent sensing system based on molecularly imprinted phase-change microcapsules and carbon quantum dots for high-efficient detection of tetracycline.

Aiming at enhancing the detection efficiency and identification accuracy of tetracycline under a high-temperature condition, this study focuses on an innovative fluorescent sensing system (MIP@CQD-PCM) based on molecularly imprinted phase-change microcapsules along with the carbon quantum dots (CQDs) embedded in their shell. This system was fabricated by microencapsulating n-eicosane as a phase change material (PCM) core within a CQDs-embedded SiO2 shell, followed by coating a tetracycline-templated molecularly imprinted polymer (MIP) layer onto the surface of the SiO2 shell. The specific recognition sites to tetracycline molecules were finally achieved by removal of tetracycline template from the MIP layer. Comprehensive characterizations and investigations on the structure and performance of the fluorescent sensing system were given to confirm its successful fabrication in accordance to our design strategy. The resultant MIP@CQD-PCM exhibits a satisfactory thermal storage capacity and phase-change cycle stability for temperature regulation and thermal management applications under a phase-change enthalpy of over 162 J/g. Most of all, a typical fluorescence-quenching effect was obtained from the combination of the CQDs embedded in the SiO2 shell and the tetracycline molecules adsorbed in the MIP layer. This makes the MIP@CQD-PCM achieve an enhanced capability for the fluorescence identification of tetracycline in a high-temperature environment through the in situ thermal management of its PCM core. The MIP@CQD-PCM also displays high selectivity and good reusability for tetracycline detection in industrial applications. This work provides a promising strategy for the design and development of fluorescent sensing systems with high recognition efficiency and identification accuracy in the detection of hazardous substances.

Fabrication of PAMAM antimicrobial monolayer via UV induced grafting on the surface of polyethylene terephthalate.

Poly (amidoamine) (PAMAM) with 3rd and 5th generation was covalently grafted as the contact active biocidal agent on the surface of polyethylene terephthalate (PET) with the help of UV induced carbene chemistry (PAMAM-g-PET). The graft density and the surface roughness were controlled by turning UV irradiation time and the PAMAM generation. The PAMAM graft monolayer was characterized via the contact angle, XPS, nanoIR, SEM and AFM. The antibacterial ability of PAMAM-g-PET was evaluated ex-vivo with the help of laser scanning confocal microscope (CLSM), and the results indicated that the decorated PET was able to kill both S. aureus and E. coli in the aqueous environment. Increasing the surface graft concentration and using the dendrimer with higher generation enhanced the lethality towards the bacterial. The decorated film was still able to kill the contact bacterial strain when the cationic primary amine groups were shielded by acetyl chloride, however, the bacterial in the suspension was hardly affected in this case. The un-selectivity and instantaneity of carbene chemistry endowed this grafting strategy the potential to be extended to other organic substances.

Fabrication of polyimide/graphene nanosheet composite fibers via microwave-assisted imidization strategy.

Here, a rapid and efficient strategy was introduced to prepare polyimide/graphene nanosheet (PI/GN) composite fibers by microwave-assisted imidization. The mechanical properties of the PI/GNs (1 wt%) fibers treated by microwave-assisted imidization were apparently improved with the tensile strength of 1.12 GPa at 350 °C, which was approximately 1.7 times as much as those treated with traditional thermal imidization. The PI/GNs (1 wt%) fibers heated by the microwave-assisted imidization method exhibited excellent thermal stabilities of up to 570.3 °C in nitrogen for a 5% weight loss, and a glass transition temperature above 339 °C. The results of the infrared spectrum and thermal properties indicated that the microwave-assisted treatment could promote the imidization degree of the PI/GN fibers prominently. Meanwhile, as a microwave absorber, graphene nanosheets (GNs) could also promote the imidization process by converting microwave energy into thermal energy. The microwave-polyimide/graphene nanosheet (MW-PI/GN) fibers possessed an optimum tensile strength of 1.38 GPa and modulus of 56.82 GPa at the GN content of 0.25 wt%. The 5% weight loss temperature in nitrogen ranged from 520.9 °C to 570.3 °C, and the glass transition temperature was increased from 305.7 °C to 339.1 °C with increasing the GN content.