Search

To investigate the risk factors of left atrial appendage thrombus (LAAT) in patients with non-valvular atrial fibrillation (AF).

Reusable nanoporous polyimide (PI) aerogels are rather promising for highly efficient thermal insulation of future thermal protection systems demanded in aerospace and domestic applications. However, the development of high-performance PI aerogels is limited by their unsatisfactory high-temperature resistance and poor reusability. Herein, an Al2O3-hybridization strategy toward PI aerogels is demonstrated, and the formed aerogels exhibit a nanoporous structure, unusual reusability, and exceptional high-temperature resistance. Furthermore, the aerogels retain their high-level properties such as the very small changing rates of mass (≤0.3%), shrinkage (≤2.53%), thermal conductivity (≤3%), and bulk density (near-zero difference) even after five cycles of high-temperature assessment (250 °C for 2400 s). The conventional huge heat-induced shrinkage of PI aerogels could be substantially restrained even bearing a high-temperature environment, realizing near-zero thermally insulating degradation, which has an outstanding practical application value. The high-temperature resistance of the aerogel is greatly improved by the Al–O network constructed inside the PI aerogels, and this resistance is retained even after multiple cycles under harsh conditions, ultimately affording superior reusability to PI aerogels for the first time. The high-temperature resistance and ultralow heat-induced shrinkage properties of aerogels, as well as their reusability, make them favorable candidates as thermal protection materials for the future development of aircraft and military. [ABSTRACT FROM AUTHOR]

Polyimide aerogels (PIAs) are thermally insulating materials that possess various advantages, such as exceptionally high temperature resistance and low thermal conductivity, which make them great potential candidate materials to be applied in the area of thermal protection. However, under harsh mechanical stresses, the macro- and microscopic structural stability of PIAs may be compromised due to shrinkage/collapse, leading to performance degradation. Herein, we propose a homogeneous organic/inorganic hybrid formation strategy for constructing nanoporous polyimide/silica aerogels (PIAs-A) with exceptional mechanical strength and ultralow thermal conductivity. The results obtained indicate that PIAs-A have an optimal three-dimensional nanoporous network structure with a pore size distribution mainly within the range of 10–20 nm. Monitoring the temperature evolution of the material's cold surface showed that it remained at a low temperature of 37.5 °C even when the material was placed against a hot surface of 150 °C. The residual mechanical strengths of the aerogels remained at a superior level (with strength degradation being less than 9%) after exposure to ultralow and high-temperature atmospheres. Furthermore, compressive stress values at 3% strain exceeded previously reported values for PIAs by 625 and 733% at −50 and 100 °C, respectively. Meanwhile, our aerogels displayed flame resistance even when exposed to a heat source of approximately 1200 °C, possessed favorable hydrophobic properties, and maintained dimensional stability up to 504 °C. The robust mechanical and thermal insulation properties of PIAs-A make them a promising substitute material for thermal superinsulation in aircraft. [ABSTRACT FROM AUTHOR]

Macropinocytosis is an effective strategy to mitigate nutrient starvation. It can fuel cancer cell growth in nutrient‐limited conditions. However, whether and how macropinocytosis contributes to the rapid proliferation of hepatocellular carcinoma cells, which frequently experience an inadequate nutrient supply, remains unclear. Here, we demonstrated that nutrient starvation strongly induced macropinocytosis in some hepatocellular carcinoma cells. It allowed the cells to acquire extracellular nutrients and supported their energy supply to maintain rapid proliferation. Furthermore, we found that the phospholipid flippase ATP9A was critical for regulating macropinocytosis in hepatocellular carcinoma cells and that high ATP9A levels predicted a poor outcome for patients with hepatocellular carcinoma. ATP9A interacted with ATP6V1A and facilitated its transport to the plasma membrane, which promoted plasma membrane cholesterol accumulation and drove RAC1‐dependent macropinocytosis. Macropinocytosis inhibitors significantly suppressed the energy supply and proliferation of hepatocellular carcinoma cells characterised by high ATP9A expression under nutrient‐limited conditions. These results have revealed a novel mechanism that overcomes nutrient starvation in hepatocellular carcinoma cells and have identified the key regulator of macropinocytosis in hepatocellular carcinoma. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland. [ABSTRACT FROM AUTHOR]

Objective: To analyze the pregnancy outcomes of patients with cervical lesions treated by cold-knife conization (CKC). Methods: Clinical data of healthy pregnant women and pregnant women who underwent CKC in Dalian Women and Children's Medical Group from March 2010 to December 2019 were retrospectively analyzed. These patients were divided into a CKC group and a control group according to inclusion and exclusion criteria. Statistical methods were used to compare pregnancy and delivery outcomes between the two groups. Results: There were 400 patients in CKC group and control group, with 200 patients in each. There was no significant difference in the mode of delivery, abortion, ectopic pregnancy, in-hospital perinatal management, and cervical cerclage between the CKC group and the control group (P>0.05). The rates of preterm delivery, premature rupture of membranes, cesarean section, and neonatal admission in the CKC group were higher than those in the control group (P<0.05). In the CKC group, the incidence of premature rupture of membranes within six months postoperatively was higher than that after six months (P<0.05). The incidences of preterm delivery and premature rupture of membranes were not completely consistent in different conization ranges (P<0.05). Conclusion: CKC increases the incidence of preterm delivery, premature rupture of membranes, and neonatal adverse outcomes. Conization height can predict the occurrence of preterm delivery. Delaying pregnancy after surgery can reduce the incidence of adverse outcomes during the perinatal period. [ABSTRACT FROM AUTHOR]

As naturally derived material, cellulose aerogels have excellent thermal insulation properties due to their unique high porosity and three-dimensional mesoporous structure. However, its hydrophilic properties limit its application in the field of building insulation. Here, we propose a method to prepare high hydrophobicity by adopting the sol-gel method and chemical vapor reaction strategy using cellulose acetate type II as raw material and 2,4-toluene diisocyanate as the cross-linking agent. Thermal properties of cellulose acetate aerogels (CAAs) were measured, where pyridine was the catalyst, acetone was the solvent, and perfluorodecyltriethoxysilane (PFDS), hexamethyldisilazane (HMDS), and methyltriethoxysilane (MTES) were used as hydrophobic agents (by process hydrophobic test). Compared with MTES-modified cellulose acetate aerogels (M-CAAs) and HMDS (H-CAAs)-modified cellulose acetate aerogels, PFDS-modified (P-CAAs) cellulose acetate aerogels are the most hydrophobic. By implementing hydrophobic modification of PFDS both inside and outside the structure of cellulose acetate aerogels, the water contact angle can reach up to 136°, strongly demonstrating the potential of PFDS as a hydrophobic agent. The results show that the thermal conductivity and compressive strength of cellulose acetate aerogel with the best hydrophobic properties are 0.035 W m−1 K−1 at normal pressure and 0.39 MPa at 3% strain, respectively. This work shows that the highly hydrophobic cellulose acetate aerogel has potential as a waterproof material in the field of building thermal-insulation materials. [ABSTRACT FROM AUTHOR]

High‐performance thermal protective composites with lightweight, micro‐ ablation and high‐efficient thermal insulation are urgently required for thermal protection systems in advanced hypersonic speed vehicles. However, the practical applications of thermal protective composites have long been hampered by the main issues such as low mass residual rate and poor long‐term antioxidation of the matrix in high‐temperature aerobic environments. Here, we report a novel silica‐polybenz oxazine (SiO2‐PBO) aerogels with interpenetrated networks, possessing the ability to antioxidation, thermal insulation, and flame‐retardant properties. The resulting SiO2‐PBO aerogels exhibit low density (0.25 g/cm3), low thermal conductivity (0.035 W/(m·K)), and superior peak heat release rate value (15.3 W/g). Moreover, the mass residual rate is up to 70.46 wt% in the N2 atmosphere and remains 57.83 wt% despite existing in the air atmosphere and experiencing the highest temperature of 800°C. Briefly, SiO2‐PBO aerogels as‐prepared could be a potential matrix for a new gene ration of high‐performance thermal protective composites in the future. [ABSTRACT FROM AUTHOR]

Triple‐negative breast cancer (TNBC) is fast‐growing and highly metastatic with the poorest prognosis among the breast cancer subtypes. Inactivation of glycogen synthase kinase 3 beta (GSK3β) plays a vital role in the aggressiveness of TNBC; however, the underlying mechanism for sustained GSK3β inhibition remains largely unknown. Here, we find that protein phosphatase 1 regulatory inhibitor subunit 14C (PPP1R14C) is upregulated in TNBC and relevant to poor prognosis in patients. Overexpression of PPP1R14C facilitates cell proliferation and the aggressive phenotype of TNBC cells, whereas the depletion of PPP1R14C elicits opposite effects. Moreover, PPP1R14C is phosphorylated and activated by protein kinase C iota (PRKCI) at Thr73. p‐PPP1R14C then represses Ser/Thr protein phosphatase type 1 (PP1) to retain GSK3β phosphorylation at high levels. Furthermore, p‐PPP1R14C recruits E3 ligase, TRIM25, toward the ubiquitylation and degradation of non‐phosphorylated GSK3β. Importantly, the blockade of PPP1R14C phosphorylation inhibits xenograft tumorigenesis and lung metastasis of TNBC cells. These findings provide a novel mechanism for sustained GSK3β inactivation in TNBC and suggest that PPP1R14C might be a potential therapeutic target. [ABSTRACT FROM AUTHOR]

Objective: To compare the survival and recurrence outcomes between open and laparoscopic radically hysterectomy (RH) for stage IA2-IIA2 cervical cancer based on Federation International of Gynecology and Obstetrics (FIGO) 2018. Methods: Data of 1,373 early cervical cancer patients undergoing open or laparoscopic radically hysterectomy at ShengJing Hospital of China Medical University between January 1, 2013, and December 31, 2016, were retrospectively reviewed. Propensity score-based inverse probability of treatment weighting (PS-IPTW) was used to balance the covariates between the two groups. Results: A total of 705 cervical cancer patients of FIGO 2009 stage IA2-IIA2 were finally enrolled in this study. After IPTW adjustment, the OS (HR = 2.095, 95% CI: 1.233-3.562, P = 0.006) and PFS (HR = 1.950, 95%CI: 1.194-3.184, P = 0.008) rates were significantly higher in the open RH (ORH) group compared with the laparoscopic RH (LRH) group. Then after re-staging according to the FIGO 2018 staging system, 561 patients still belonged to stage IA2-IIA2, 144 patients were upgraded to stage IIIC1p-IIIC2p. The ORH group had a significantly superior OS (HR = 1.977, 95%CI: 1.077-3.626, P = 0.028) and PFS (HR = 1.811, 95%CI: 1.046-3.134, P = 0.034) compared with the LRH group after PS-IPTW analysis. Furthermore, in patients with no high and intermediate risks, difference of the OS (HR = 1.386, 95%CI: 0.287-6.69, P = 0.684) and PFS (HR = 1.524, 95%CI: 0.363-6.396, P = 0.565) rates between the two groups were with no statistical meaning. Conclusions: Outcomes of this retrospective cohort study were in compliance with indications for ORH recommended by the National Comprehensive Cancer Network guidelines Version 1, 2021. However, LRH showed non-inferiority for patients with no prognostic risk factors compared with ORH. [ABSTRACT FROM AUTHOR]

Materials with high‐performance thermal insulation and excellent flame‐resistance are incredibly desirable for energy conservation and fire safety. In this study, a novel hybrid nanostructure network polybenzoxazine/silica (PBO/SiO2) aerogels were fabricated through facile in situ co‐polymerization sol‐gel methods with ambient pressure drying using benzoxazine (BO) monomers and SiO2 sol as reaction source, N, N‐dimethylformamide (DMF) as the solvent and hydrochloric acid (HCl) as the catalyst. The hybrid nanostructure network was retained by polymerization–induced nanoscale phase separation of PBO and SiO2. The resulting PBO/SiO2 aerogels exhibited finer microstructure, lower density (0.18 g/cm3), thermal conductivity (0.031 W/m·K), and better flame‐resistance in comparison with PBO aerogels. They demonstrated an excellent compressive strength of 0.81 to 1.12 MPa at 10% deformation. The remarkable improvement in thermal insulation and flame‐resistance of PBO/SiO2 aerogels could be attributed to the combined effects of finer microstructure and formation of SiO2 that was "in‐situ" interpenetrated and interacted with silanols (Si‐OH) in the PBO network during the combustion process. The successful synthesis of PBO/SiO2 aerogels highlights the possibility of fabricating a novel high‐performance thermal insulation and excellent flame‐resistance used for energy‐efficient buildings. [ABSTRACT FROM AUTHOR]

The quest for ambient pressure dried, cost‐effective, and environmentally friendly synthesis technology has been continuously pursued throughout the aerogel research process. Herein, oxalic acid catalyst is used to synthesize a series of polybenzoxazine (PBZ) aerogels through room temperature ring‐opening polymerization and ambient pressure drying technique based on phenol‐4,4′‐diaminodiphenylmethane benzoxazine (PH–mda) monomer. The resultant PBZ aerogels with a microstructure of 3D nanoporous network exhibit a low density of 0.13–0.36 g cm−3 and relatively low thermal conductivities of 0.0323 (105 Pa) and 0.0119 W m−1 K−1 (10 Pa), respectively. Remarkably, PBZ aerogels possess excellent compressibility (the maximum strain can be more than 80%), high compressive modulus, and specific modulus because of their rough skeleton structure. Taking advantage of the simple synthetic route, easily scaled‐up, lightweight, low thermal conductivity, and excellent mechanical property, such PBZ aerogels may have great potential to serve as a new material for energy‐efficient buildings and the other thermal insulating field. [ABSTRACT FROM AUTHOR]

Cell–material interactions and compatibility are important aspects of bioactive materials for bone tissue engineering. Phosphate glass fiber (PGF) is an attractive inorganic filler with fibrous structure and tunable composition, which has been widely investigated as a bioactive filler for bone repair applications. However, the interaction of osteoblasts with PGFs has not been widely investigated to elucidate the osteogenic mechanism of PGFs. In this study, different concentrations of short PGFs with interlaced oriented topography were cocultured with MC3T3‐E1 cells for different periods, and the synergistic effects of fiber topography and ionic product of PGFs on osteoblast responses including cell adhesion, spreading, proliferation, and osteogenic differentiation were investigated. It was found that osteoblasts were more prone to adhere on PGFs through Vinculin protein, leading to enhanced cell proliferation with polygonal cell shape and spreading cellular actin filaments. In addition, osteoblasts incubated on PGF meshes showed enhanced alkaline phosphatase activity, extracellular matrix mineralization, and increased expression of osteogenesis‐related marker genes, which could be attributed to the Wnt/β‐catenin/Runx2 signaling pathway. This study elucidated the possible mechanism of PGF on triggering specific osteoblast behavior, which would be highly beneficial for designing PGF‐based bone graft substitutes with excellent osteogenic functions. [ABSTRACT FROM AUTHOR]

Angiogenesis is a crucial event during cancer progression that regulates tumor growth and metastasis. Activin receptor-like kinase 1 (ALK1), predominantly expressed in endothelial cells, plays a key role in the organization of neo-angiogenic vessels. Therapeutic targeting of ALK1 has been proposed as a promising strategy for cancer treatment, and microRNAs (miRNAs) are increasingly being explored as modulators of angiogenesis. However, the regulation of ALK1 by miRNAs is unclear. In this study, we identified that ALK1 is directly targeted by miR-199b-5p, which was able to inhibit angiogenesis in vitro and in vivo. Moreover, it was found that miR-199b-5p was repressed in breast cancer cells and its expression was decreased during the VEGF-induced angiogenesis process of human umbilical vein endothelial cells (HUVECs). Overexpression of miR-199b-5p inhibited the formation of capillary-like tubular structures and migration of HUVECs. Furthermore, overexpression of miR-199b-5p inhibited the mRNA and protein expression of ALK1 in HUVECs by directly binding to its 3'UTR. Additionally, overexpression of miR-199b-5p attenuated the induction of ALK1/Smad/Id1 pathway by BMP9 in HUVECs. Finally, overexpression of miR-199b-5p reduced tumor growth and angiogenesis in in vivo. Taken together, these findings demonstrate the anti-angiogenic role of miR-199b-5p, which directly targets ALK1, suggesting that miR-199b-5p might be a potential anti-angiogenic target for cancer therapy. [ABSTRACT FROM AUTHOR]

Background/aim: This study aimed to compare neoadjuvant chemotherapy (NAC) followed by interval debulking surgery (IDS) with primary debulking surgery (PDS) followed by chemotherapy in patients with advanced ovarian carcinoma International Federation of Gynecology and Obstetrics (FIGO) stages IIIc and IV.Methods: PubMed, the Cochrane Library, and manual searches were applied to discriminate potentially eligible studies published before June 30, 2016.Results: A total of 12 comparative studies were finally included; 1,372 patients underwent NAC followed by IDS, and 2,680 patients underwent PDS followed by chemotherapy. For overall pooled estimates, significant between-trial differences were found in the optimal debulking rate, grade 3-5 postoperative adverse reactions, and median overall survival (OS), but no difference was found in the median progression-free survival (PFS). Moreover, a significantly higher incidence was identified in major infections, vascular events, and wound complications for patients in the PDS group.Conclusions: This study suggested that NAC followed by IDS could improve the optimal debulking rate and decrease the postoperative adverse reactions for the current studies, but whether it could improve the OS and PFS compared with PDS followed by chemotherapy in patients with ovarian carcinoma FIGO stages IIIc and IV were still needed to be verified by conducting more randomized controlled trials. [ABSTRACT FROM AUTHOR]

Spectraplakins are a family of evolutionarily conserved gigantic proteins and play critical roles in many cytoskeleton-related processes. Microtubule actin crosslinking factor 1 (MACF1) is one of the most versatile spectraplakin with multiple isoforms. As a broadly expressed mammalian spectraplakin, MACF1 is important in maintaining normal functions of many tissues. The loss-of-function studies using knockout mouse models reveal the pivotal roles of MACF1 in embryo development, skin integrity maintenance, neural development, bone formation, and colonic paracellular permeability. Mutation in the human MACF1 gene causes a novel myopathy genetic disease. In addition, abnormal expression of MACF1 is associated with schizophrenia, Parkinson’s disease, cancer and osteoporosis. This demonstrates the crucial roles of MACF1 in physiology and pathology. Here, we review the research advances of MACF1’s roles in specific tissue and in human diseases, providing the perspectives of MACF1 for future studies. [ABSTRACT FROM AUTHOR]

By using a simple solution chemistry approach with polyvinyprrolidone (PVP) as a capping agent, Mn2W(CN)8 · xH2O microcrystals with unique morphologies including rice-like, rod, octahedron, square platelet, and hollow-core square platelet have been successfully synthesized. The influence of experimental parameters such as reaction temperature, feed ratio of Mn2+ to PVP, reaction time, and reactant concentration on the morphology and size of Mn2W(CN)8 · xH2O microcrystals were systematically investigated. The reaction temperature proved to be a key factor for morphological evolution of the products. It was found that 20, 55, and 85 °C were key points of morphological transformation. A possible growth mechanism of the Mn2W(CN)8 · xH2O microcrystals is proposed. [ABSTRACT FROM AUTHOR]

The preparation of novel polymer aerogel materials with enhanced flame-retardancy, superior thermal insulation and mechanical strength is of great practical significance in energy-savings and fire-prevention for buildings. Herein, we reported the fiber-reinforced polybenzoxazine (PBO) aerogel composites with flame retardance and thermal insulation, which were prepared under room temperature and atmospheric pressure, and using 4,4′-diaminodiphenlymethane (MDA) benzoxazine monomer as the raw material and oxalic acid (OA) as the catalyst. Several outstanding attributes were achieved in the aerogel composites, such as relatively low thermal conductivity (0.069 W/m·K at 105 Pa, 0.031 W/m·K at 5 Pa), high limiting oxygen index (LOI) up to 32.5, and enhanced mechanical properties. It can be compressed to more than 80% of the deformation without obvious cracks, and shows high compressive modulus and specific modulus (20.69 MPa and 5.05 × 104 N·m/Kg, respectively). All the excellent comprehensive properties mean that fiber-reinforced PBO aerogel composites have broad application prospects in the fields of flame retardancy and thermal insulation. [ABSTRACT FROM AUTHOR]

Resistance to tamoxifen is a clinically major challenge in breast cancer treatment. Although downregulation of estrogen receptor‐alpha (ERα) is the dominant mechanism of tamoxifen resistance, the reason for ERα decrease during tamoxifen therapy remains elusive. Herein, we reported that Spalt‐like transcription factor 2 (SALL2) expression was significantly reduced during tamoxifen therapy through transcription profiling analysis of 9 paired primary pre‐tamoxifen‐treated and relapsed tamoxifen‐resistant breast cancer tissues. SALL2 transcriptionally upregulated ESR1 and PTEN through directly binding to the DNA promoters. By contrast, silencing SALL2 induced downregulation of ERα and PTEN and activated the Akt/mTOR signaling, resulting in estrogen‐independent growth and tamoxifen resistance in ERα‐positive breast cancer. Furthermore, hypermethylation of SALL2 promoter was found in tamoxifen‐resistant breast cancer. Importantly, in vivo experiments showed that DNA methyltransferase inhibitor‐mediated SALL2 restoration resensitized tamoxifen‐resistant breast cancer to tamoxifen therapy. These findings shed light on the mechanism of SALL2 in regulation of ER and represent a potential clinical signature that can be used to categorize breast cancer patients who may benefit from co‐therapy with tamoxifen and DNMT inhibitor. Synopsis: Resistance to tamoxifen is a clinically important challenge for breast cancer treatment. This study uncovers a mechanism by which the transcription factor SALL2 regulates ERα, and identifies a subset of breast cancer patients who might benefit from tamoxifen/DNMTs inhibitor co‐therapy. ALL2 hypermethylation status was correlated with poorer clinical outcomes in breast cancer patients receiving tamoxifen therapy.Promoter methylation‐mediated SALL2 silencing conferred tamoxifen resistance and estrogen‐independent cell growth in breast cancer.Loss of SALL2 transcriptionally downregulated both ESR1 and PTEN, resulting in inhibition of Erα activity and activation of PI3K/Akt signaling.Restoration of SALL2 using DNMT inhibitor 5‐Aza‐dC re‐sensitized a subset of breast cancer to tamoxifen therapy in vivo. [ABSTRACT FROM AUTHOR]

Osteoclasts are responsible for bone resorption and play essential roles in causing bone diseases such as osteoporosis. Microtubule actin crosslinking factor 1 (MACF1) is a large spectraplakin protein that has been implicated in regulating cytoskeletal distribution, cell migration, cell survival and cell differentiation. However, whether MACF1 regulates the differentiation of osteoclasts has not been elucidated. In this study, we found that the expression of MACF1 was increased in primary bone marrow-derived monocytes (BMMs) of osteoporotic mice and was downregulated during receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclastogenesis of pre-osteoclast cell lines RAW264.7 cells. RAW264.7 cells were transfected with shMACF1 using a lentiviral vector to study the role of MACF1 in osteoclastogenic differentiation. Knockdown of MACF1 in RAW264.7 cells inhibited the formation of multinucleated osteoclasts and decreased the expression of osteoclast-marker genes (Ctsk , Acp5 , Mmp9 and Oscar) during RANKL-induced osteoclastogenesis. Additionally, knockdown of MACF1 disrupted actin ring formation in osteoclasts and further blocked the bone resorption activity of osteoclasts by reducing the area and depth of pits. Knockdown of MACF1 had no effect on the survival of pre-osteoclasts and mature osteoclasts. We further established that knockdown of MACF1 attenuated the phosphorylation of Akt and GSK3β and inhibited the expression of its downstream target NFATc1. Akt activator rescued the inhibition of osteoclast differentiation by MACF1 knockdown. These data demonstrate that MACF1 positively regulates osteoclast differentiation via the Akt/GSK3β/NFATc1 signalling pathway, suggesting that targeting MACF1 may be a novel therapeutic approach against osteoporosis. • MACF1 knockdown inhibited RANKL-induced osteoclast differentiation and activity. • MACF1 knockdown has no effect on the survival of pre-osteoclasts and mature osteoclasts. • MACF1 knockdown attenuated the phosphorylation of Akt and GSK3β induced by RANKL. • MACF1 knockdown attenuated RANKL-induced osteoclast differentiation by regulating the Akt/GSK3β/NFATc1 signalling pathway. [ABSTRACT FROM AUTHOR]

Polybenzoxazine (PBO) aerogels with low densities and low thermal conductivities are prepared from Bisphenol A (BPA) benzoxazine monomers by ring‐opened polymerisation using HCl as a catalyser at 10 °C. The obtained PBO aerogels have cross‐linked and 3D network structures with the densities ranging from 0.084 to 0.526 g cm−3. The thermal conductivities under different pressures (3–105 Pa, air) and different atmospheres (N2, Ar, and CO2, 105 Pa) are investigated. The thermal conductivities are in the range of 0.0335–0.0652 W m K−1 under ambient pressure and 0.0098–0.0571 W m K−1 at 3 Pa. The thermal transfer mechanism under different gas pressures is analyzed with increasing pressure. Under different atmospheres, the thermal conductivities decrease as the molecular weight of the gas increases. Compared with the traditional organic foam insulating materials of phenolic foam, polyurethane and polystyrene, which have similar apparent densities, PBO aerogels exhibit lower thermal conductivity of 0.0335 W m K−1 than that of traditional organic foam at room temperature. [ABSTRACT FROM AUTHOR]