LINC00606 promotes glioblastoma progression through sponge miR-486-3p and interaction with ATP11B.

BACKGROUND: LncRNAs regulate tumorigenesis and development in a variety of cancers. We substantiate for the first time that LINC00606 is considerably expressed in glioblastoma (GBM) patient specimens and is linked with adverse prognosis. This suggests that LINC00606 may have the potential to regulate glioma genesis and progression, and that the biological functions and molecular mechanisms of LINC00606 in GBM remain largely unknown. METHODS: The expression of LINC00606 and ATP11B in glioma and normal brain tissues was evaluated by qPCR, and the biological functions of the LINC00606/miR-486-3p/TCF12/ATP11B axis in GBM were verified through a series of in vitro and in vivo experiments. The molecular mechanism of LINC00606 was elucidated by immunoblotting, FISH, RNA pulldown, CHIP-qPCR, and a dual-luciferase reporter assay. RESULTS: We demonstrated that LINC00606 promotes glioma cell proliferation, clonal expansion and migration, while reducing apoptosis levels. Mechanistically, on the one hand, LINC00606 can sponge miR-486-3p; the target gene TCF12 of miR-486-3p affects the transcriptional initiation of LINC00606, PTEN and KLLN. On the other hand, it can also regulate the PI3K/AKT signaling pathway to mediate glioma cell proliferation, migration and apoptosis by binding to ATP11B protein. CONCLUSIONS: Overall, the LINC00606/miR-486-3p/TCF12/ATP11B axis is involved in the regulation of GBM progression and plays a role in tumor regulation at transcriptional and post-transcriptional levels primarily through LINC00606 sponging miR-486-3p and targeted binding to ATP11B. Therefore, our research on the regulatory network LINC00606 could be a novel therapeutic strategy for the treatment of GBM.

Chemical characterization and source apportionment of PM2.5 in a Northeastern China city during the epidemic period.

To investigate the influence of COVID-19 lockdown measures on PM2.5 and its chemical components in Shenyang, PM2.5 samples were continuously collected from January 1 to May 31, 2020. The samples were then analyzed for water-soluble inorganic ions, metal elements, organic carbon, and elemental carbon. The findings indicated a significant decrease in PM2.5 and its various chemical components during the lockdown period, compared to pre-lockdown levels (p < 0.05), suggesting a substantial improvement in air quality. Water-soluble inorganic ions (WSIIs) were identified as the primary contributors to PM2.5, accounting for 47% before the lockdown, 46% during the lockdown, and 37% after the lockdown. Ionic balance analysis revealed that PM2.5 exhibited neutral, weakly alkaline, and alkaline characteristics before, during, and after the lockdown, respectively. NH4+ was identified as the main balancing cation and was predominantly present in the form of NH4NO3 in the absence of complete neutralization of SO42- and NO3-. Moreover, the higher sulfur oxidation ratio (SOR) and nitrogen oxidation ratio (NOR), along with the significant increase in PM2.5/EC, suggested intense secondary transformation during the lockdown period. The elevated OC/EC ratio during the lockdown period implied higher secondary organic carbon (SOC), and the notable increase in SOC/EC ratio indicated a significant secondary transformation of total carbon. The enrichment factor (EF) results revealed that during the lockdown, 9 metal elements (As, Sn, Pb, Zn, Cu, Sb, Ag, Cd, and Se) were substantially impacted by anthropogenic emissions. Source analysis of PMF was employed to identify the sources of PM2.5 in Shenyang during the study period, and the analysis identified six factors: secondary sulfate and vehicle emissions, catering fume sources, secondary nitrate and coal combustion emissions, dust sources, biomass combustion, and industrial emissions, with secondary sulfate and vehicle emissions and catering fume sources contributing the most to PM2.5.

TIG1 Inhibits the mTOR Signaling Pathway in Malignant Melanoma Through the VAC14 Protein.

BACKGROUND/AIM: Currently, there are few drug options available to treat malignant melanoma. Tazarotene-inducible gene 1 (TIG1) was originally isolated from skin tissue, but its function in skin tissue has not been clarified. The aim of this study was to elucidate the effect of TIG1 and mTOR signaling pathways associated with VAC14 on melanoma. MATERIALS AND METHODS: The expression of TIG1 and VAC14 in melanoma tissue was analyzed using a melanoma tissue cDNA array. The interaction between TIG1 and VAC14 was analyzed using immunoprecipitation and immunostaining. Western blot was used to investigate the molecular targets of TIG1 and VAC14 in melanoma cells. RESULTS: TIG1 was highly expressed in normal skin tissue but was low in malignant melanoma, while VAC14 showed the opposite trend. TIG1 inhibited insulin-induced cell proliferation and insulin-activated mammalian target of rapamycin complex 1 (mTORC1)-p70 S6 kinase but did not affect the level of phospho-AKT in A2058 melanoma cells. This suggests that the main target of TIG1 regulating cell growth is phosphatidylinositol 3,5-bisphosphate [PI(3,5)P2] rather than the PI(4,5)P2 signaling pathway. Additional TIG1 showed no additive effect on the inhibition of mTOR signaling in the absence of VAC14 expression, suggesting that TIG1 inhibited the activation of mTOR mainly by inhibiting VAC14. CONCLUSION: TIG1 may play an important role in preventing malignant melanoma through retinoic acid via VAC14.

Single-Atom and Hierarchical-Pore Aerogel Confinement Strategy for Low-Platinum Fuel Cells.

Achieving high catalytic performance through the lowest possible content of platinum (Pt) is the key to cost reduction of proton-exchange-membrane fuel cells (PEMFCs). However, lowering the Pt loading in PEMFCs leads to the high mass-transport resistance of oxygen originating from the limited active sites, and causes less stability of the catalysts due to Pt size growth after long-time operation. Herein, Pt-metal/metal-N-C aerogel catalysts are designed that substantially reduce oxygen-related mass transport resistance and have long-term durability. The tailoring of the Fe-N-C aerogel support with hierarchical and interconnecting pores enable a low local oxygen transport resistance (0.18 s cm-1 ) for PEMFCs with ultralow Pt loading (50 ± 5 µgPt cm- 2 ). Chemical confinement of Fe─N sites ensures high stability of the loaded-Pt both in the processes of synthesis up to 1000 °C and practical application in PEMFCs. The ultralow Pt PEMFC displays a low voltage loss of 8 mV at 0.80 A cm- 2 and unchanged electrochemical surface area after 60 000 cycles of accelerated durability testing. The allying of the hierarchical pores, the aerogel, and the single atoms can fully reflect their structural advantages and expand the understanding for the synthesis of advanced fuel cell PEMFCs catalysts.

Gold Nanoparticles Enhancing Generation of ROS for Cs-137 Radiotherapy.

Radiotherapy is an important modality for the treatment of cancer, e.g., X-ray, Cs-137 γ-ray (peak energy: 662 keV). An important therapy pathway of radiation is to generate the double strand breaks of DNA to prohibit the proliferation of cancer cells. In addition, the excessive amount of reactive oxygen species (ROS) is induced to damage the organelles, which can cause cellular apoptosis or necrosis. Gold nanoparticles (GNPs) have been proven potential as a radiosensitizer due to the high biocompatibility, the low cytotoxicity and the high-Z property (Z = 79) of gold. The latter property may allow GNPs to induce more secondary electrons for generating ROS in cells as irradiated by high-energy photons. In this paper, the radiobiological effects on A431 cells with uptake of 55-nm GNPs were studied to investigate the GNPs-enhanced production of ROS on these cells as irradiated by Cs-137 γ-ray. The fluorescence-labeling image of laser scanning confocal microscopy (LSCM) shows the excessive expression of ROS in these GNPs-uptake cells after irradiation. And then, the follow-up disruption of cytoskeletons and dysfunction of mitochondria caused by the induced ROS are observed. From the curves of cell survival fraction versus the radiation dose, the radiosensitization enhancement factor of GNPs is 1.29 at a survival fraction of 30%. This demonstrates that the tumoricidal efficacy of Cs-137 radiation can be significantly raised by GNPs. Because of facilitating the production of excessive ROS to damage tumor cells, GNPs are proven to be a prospective radiosensitizer for radiotherapy, particularly for the treatment of certain radioresistant tumor cells. Through this pathway, the tumoricidal efficacy of radiotherapy can be raised.

Coumarin Derivatives Inhibit ADP-Induced Platelet Activation and Aggregation.

Coumarin was first discovered in Tonka bean and then widely in other plants. Coumarin has an anticoagulant effect, and its derivative, warfarin, is a vitamin K analogue that inhibits the synthesis of clotting factors and is more widely used in the clinical treatment of endovascular embolism. At present, many artificial chemical synthesis methods can be used to modify the structure of coumarin to develop many effective drugs with low toxicity. In this study, we investigated the effects of six coumarin derivatives on the platelet aggregation induced by adenosine diphosphate (ADP). We found that the six coumarin derivatives inhibited the active form of GPIIb/IIIa on platelets and hence inhibit platelet aggregation. We found that 7-hydroxy-3-phenyl 4H-chromen-4-one (7-hydroxyflavone) had the most severe effect. In addition, we further analyzed the downstream signal transduction of the ADP receptor, including the release of calcium ions and the regulation of cAMP, which were inhibited by the six coumarin derivatives selected in this study. These results suggest that coumarin derivatives inhibit coagulation by inhibiting the synthesis of coagulation factors and they may also inhibit platelet aggregation.

Versatile Thermal-Solidifying Direct-Write Assembly towards Heat-Resistant 3D-Printed Ceramic Aerogels for Thermal Insulation.

Ceramic aerogels have great potential in the areas of thermal insulation, catalysis, filtration, environmental remediation, energy storage, etc. However, the conventional shaping and post-processing of ceramic aerogels are plagued by their brittleness due to the inefficient neck connection of oxide ceramic nanoparticles. Here a versatile thermal-solidifying direct-ink-writing has been proposed for fabricating heat-resistant ceramic aerogels. The versatility lies in the good compatibility and designability of ceramic inks, which makes it possible to print silica aerogels, alumina-silica aerogels, and titania-silica aerogels. 3D-printed ceramic aerogels show excellent high-temperature stability up to 1000 °C in air (linear shrinkage less than 5%) when compared to conventional silica aerogels. This improved heat resistance is attributed to the existence of a refractory fumed silica phase, which restrains the microstructure destruction of ceramic aerogels in high-temperature environments. Benefiting from low density (0.21 g cm-3 ), high surface area (284 m2 g-1 ), and well-distributed mesopores, 3D-printed ceramic aerogels possess a low thermal conductivity (30.87 mW m-1 K-1 ) and are considered as ideal thermal insulators. The combination of ceramic aerogels with 3D printing technology would open up new opportunities to tailor the geometry of porous materials for specific applications.

Research on the Consumption Trend, Nutritional Value, Biological Activity Evaluation, and Sensory Properties of Mini Fruits and Vegetables.

Mini fruits and vegetables (MFV) are pocket fruits and vegetables whose shape and volume are significantly smaller than those widely sold and well-known normal fruits and vegetables (NFV) on the market. Through the research on the market status and consumption trends of MFV, it was found that MFV have recently become a new market favorite. However, compared with NFV, there was found to be no relevant data on sensory quality, nutritional value, safety, etc. of MFV; this could indicate low consumer awareness of MFV, which in turn affects their planting and sales choices, as well as the market scale remaining small. In this context, six MFV with high degree of marketization were selected and compared with their corresponding NFV to evaluate the nutritional value, biological activity, and sensory properties. The results showed the nutritional value of MFV to be mainly related to their species. The nutritional value of MFV derived from immature, tender vegetables was generally lower than that of mature NFV. For example, the content of zeaxanthin in normal maize was 0.43 mg/kg, which was about 2.87 times that of mini maize (0.15 mg/kg). For newly cultivated mini varieties, their nutritional value often had different trends and rules compared with NFV. The nutritional value obtained by consuming MFV is not equal to that obtained by consuming the corresponding NFV of the same weight.

Tournefortia sarmentosa Inhibits the Hydrogen Peroxide-Induced Death of H9c2 Cardiomyocytes.

Tournefortia sarmentosa is a traditional Chinese medicine used to reduce tissue swelling, to exert the antioxidant effect, and to detoxify tissue. T. sarmentosa is also used to promote development in children and treat heart dysfunction. However, many of the mechanisms underlying the effects of T. sarmentosa in the treatment of disease remain unexplored. In this study, we investigated the antioxidant effect of T. sarmentosa on rat H9c2 cardiomyocytes treated with hydrogen peroxide (H2O2). T. sarmentosa reduced the cell death induced by H2O2. T. sarmentosa inhibited H2O2-induced changes in cell morphology, activation of cell death-related caspases, and production of reactive oxygen species. In addition, we further analyzed the potential active components of T. sarmentosa and found that the compounds present in the T. sarmentosa extract, including caffeic acid, rosmarinic acid, salvianolic acid A, and salvianolic acid B, exert effects similar to those of the T. sarmentosa extract in inhibiting H2O2-induced H9c2 cell death. Therefore, according to the results of this study, the ability of the T. sarmentosa extract to treat heart disease may be related to its antioxidant activity and its ability to reduce the cellular damage caused by free radicals.

Three-Dimensional-Printed Silica Aerogels for Thermal Insulation by Directly Writing Temperature-Induced Solidifiable Inks.

Silica aerogels are attractive materials for various applications due to their exceptional performances and open porous structure. Especially in thermal management, silica aerogels with low thermal conductivity need to be processed into customized structures and shapes for accurate installation on protected parts, which plays an important role in high-efficiency insulation. However, traditional subtractive manufacturing of silica aerogels with complex geometric architectures and high-precision shapes has remained challenging since the intrinsic ceramic brittleness of silica aerogels. Comparatively, additive manufacturing (3D printing) provides an alternative route to obtain custom-designed silica aerogels. Herein, we demonstrate a thermal-solidifying 3D printing strategy to fabricate silica aerogels with complex architectures via directly writing a temperature-induced solidifiable silica ink in an ambient environment. The solidification of silica inks is facilely realized, coupling with the continuous ammonia catalysis by the thermolysis of urea. Based on our proposed thermal-solidifying 3D printing strategy, printed objects show excellent shape retention and have a capacity to subsequently undergo the processes of in situ hydrophobic modification, solvent replacement, and supercritical drying. 3D-printed silica aerogels with hydrophobic modification show a super-high water contact angle of 157°. Benefiting from the low density (0.25 g·cm-3) and mesoporous silica network, optimized 3D-printed specimens with a high specific surface area of 272 m2·g-1 possess a low thermal conductivity of 32.43 mW·m-1·K-1. These outstanding performances of 3D-printed silica aerogels are comparable to those of traditional aerogels. More importantly, the thermal-solidifying 3D printing strategy brings hope to the custom design and industrial production of silica aerogel insulation materials.

Tazarotene-induced gene 1 interacts with Polo-like kinase 2 and inhibits cell proliferation in HCT116 colorectal cancer cells.

Tazarotene-induced gene 1 (TIG1) is considered to be a tumor suppressor gene that is highly expressed in normal or well-differentiated colon tissues, while downregulation of TIG1 expression occurs in poorly differentiated colorectal cancer (CRC) tissues. However, it is still unclear how TIG1 regulates the tumorigenesis of CRC. Polo-like kinases (Plks) are believed to play an important role in regulating the cell cycle. The performance of PLK2 in CRC is negatively correlated with the differentiation status of CRC tissues. Here, we found that PLK2 can induce the growth of CRC cells and that TIG1 can prevent PLK2 from promoting the proliferation of CRC cells. We also found that the expression of PLK2 in CRC cells was associated with low levels of Fbxw7 protein and increased expression of cyclin E1. When TIG1 was coexpressed with PLK2, the changes in Fbxw7/cyclin E1 levels induced by PLK2 were reversed. In contrast, silencing TIG1 promoted the proliferation of CRC, and when PLK2 was also silenced, the proliferation of CRC cells induced by TIG1 silencing was significantly inhibited. The above research results suggest that TIG1 can regulate the tumorigenesis of CRC by regulating the activity of PLK2.

Safflower Extract Inhibits ADP-Induced Human Platelet Aggregation.

Safflower extract is commonly used as a traditional Chinese medicine to promote blood circulation and remove blood stasis. The antioxidant and anticancer properties of safflower extracts have been extensively studied, but their antiaggregative effects have been less analyzed. We found that safflower extract inhibited human platelet aggregation induced by ADP. In addition, we further analyzed several safflower extract compounds, such as hydroxysafflor yellow A, safflower yellow A, and luteolin, which have the same antiaggregative effect. In addition to analyzing the active components of the safflower extract, we also analyzed their roles in the ADP signaling pathways. Safflower extract can affect the activation of downstream conductors of ADP receptors (such as the production of calcium ions and cAMP), thereby affecting the expression of activated glycoproteins on the platelet membrane and inhibiting platelet aggregation. According to the results of this study, the effect of safflower extract on promoting blood circulation and removing blood stasis may be related to its direct inhibition of platelet activation.

Printed aerogels: chemistry, processing, and applications.

As an extraordinarily lightweight and porous functional nanomaterial family, aerogels have attracted considerable interest in academia and industry in recent decades. Despite the application scopes, the modest mechanical durability of aerogels makes their processing and operation challenging, in particular, for situations demanding intricate physical structures. "Bottom-up" additive manufacturing technology has the potential to address this drawback. Indeed, since the first report of 3D printed aerogels in 2015, a new interdisciplinary research area combining aerogel and printing technology has emerged to push the boundaries of structure and performance, further broadening their application scope. This review summarizes the state-of-the-art of printed aerogels and presents a comprehensive view of their developments in the past 5 years, and highlights the key near- and mid-term challenges.

Radiation Induces Pulmonary Fibrosis by Promoting the Fibrogenic Differentiation of Alveolar Stem Cells.

The lung is a radiosensitive organ, which imposes limits on the therapeutic dose in thoracic radiotherapy. Irradiated alveolar epithelial cells promote radiation-related pneumonitis and fibrosis. However, the role of lung stem cells (LSCs) in the development of radiation-induced lung injury is still unclear. In this study, we found that both LSCs and LSC-derived type II alveolar epithelial cells (AECII) can repair radiation-induced DNA double-strand breaks, but the irradiated LSCs underwent growth arrest and cell differentiation faster than the irradiated AECII cells. Moreover, radiation drove LSCs to fibrosis as shown with the elevated levels of markers for epithelial-mesenchymal transition and myofibroblast (α-smooth muscle actin (α-SMA)) differentiation in in vitro and ex vivo studies. Increased gene expressions of connective tissue growth factor and α-SMA were found in both irradiated LSCs and alveolar cells, suggesting that radiation could induce the fibrogenic differentiation of LSCs. Irradiated LSCs showed an increase in the expression of surfactant protein C (SP-C), the AECII cell marker, and α-SMA, and irradiated AECII cells expressed SP-C and α-SMA. These results indicated that radiation induced LSCs to differentiate into myofibroblasts and AECII cells; then, AECII cells differentiated further into either myofibroblasts or type I alveolar epithelial cells (AECI). In conclusion, our results revealed that LSCs are sensitive to radiation-induced cell damage and may be involved in radiation-induced lung fibrosis.

Ultrasound-Combined Sterilization Technology: An Effective Sterilization Technique Ensuring the Microbial Safety of Grape Juice and Significantly Improving Its Quality.

: The effects of ultrasound (US), thermosonication (TS), ultrasound combined with nisin (USN), TS combined with nisin (TSN), and conventional thermal sterilization (CTS) treatments on the inactivation of microorganisms in grape juice were evaluated. TS, TSN, and CTS treatments provided the desirable bactericidal and enzyme inactivation, and nisin had a synergistic lethal effect on aerobic bacteria in grape juice while not having any obvious effect on the mold and yeast. Compared with CTS, the sensory characteristics of grape juice treated with TS and TSN are closer to that of fresh juice, its microbial safety is ensured, and the physicochemical properties are basically unchanged. More importantly, the total phenolic content and antioxidant capacity of juice treated with TS and TSN were significantly increased, and the total anthocyanin and flavonoid contents were largely retained. Taken together, these findings suggest that TS and TSN has great potential application value and that it can ensure microbial safety and improve the quality of grape juice.

Cathepsin V Mediates the Tazarotene-induced Gene 1-induced Reduction in Invasion in Colorectal Cancer Cells.

Tazarotene-induced gene 1 (TIG1) is a retinoid acid receptor-responsive gene involved in cell differentiation and tumorigenesis. Aberrant methylation of CpG islands in the TIG1 promoter is found in multiple cancers. Currently, the exact mechanism underlying the anticancer effect of TIG1 is unknown. Here, we show that TIG1 interacts with cathepsin V (CTSV), which reduces CTSV stability and subsequently affects the production of activated urokinase-type plasminogen activator (uPA), an epithelial-mesenchymal transition-associated protein. Ectopic expression of CTSV increased the expression of activated uPA and the number of migrated and invaded cells, whereas ectopic TIG1 expression reversed the effects of CTSV on the uPA signaling pathway. Similar patterns in the production of activated uPA and number of migrated and invaded cells were also observed in TIG1-expressing and CTSV-knockdown cells. The results suggest that CTSV may participate in TIG1-regulated uPA activity and the associated downstream signaling pathway.

Tazarotene-Induced Gene 1 (TIG1) Interacts with Serine Protease Inhibitor Kazal-Type 2 (SPINK2) to Inhibit Cellular Invasion of Testicular Carcinoma Cells.

Tazarotene-induced gene 1 (TIG1) encodes a protein that is a retinoid-regulated tumor suppressor. TIG1 is expressed in most normal tissues, and downregulation of TIG1 expression in multiple cancers is caused by promoter hypermethylation. Kazal-type serine protease inhibitor-2 (SPINK2) is a serine protease inhibitor, and the SPINK protein family has been shown to inhibit the expression of urokinase-type plasminogen activator (uPA). In addition, increased levels of uPA and the uPA receptor were observed in testicular cancer tissues. This study demonstrated that TIG1 interacts with SPINK2 in NT2/D1 testicular carcinoma cells. TIG1 and SPINK2 were highly expressed in normal testis tissues, while low expression levels of TIG1 and SPINK2 were found in testicular cancer tissues. TIG1 inhibited cell invasion, migration, and epithelial-mesenchymal transition (EMT) of NT2/D1 cells. SPINK2 enhanced TIG1-regulated uPA activity and EMT suppression, while silencing SPINK2 alleviated TIG1-mediated EMT regulation, cell migration, and invasion. Therefore, the results suggest that the interaction between TIG1 and SPINK2 plays an important role in the inhibition of testicular cancer cell EMT, and suppression is mediated through downregulation of the uPA/uPAR signaling pathway.

The Ribosomal Protein RPLP0 Mediates PLAAT4-induced Cell Cycle Arrest and Cell Apoptosis.

Phospholipase A and acyltransferase 4 (PLAAT4) is a member of the HREV107 tumor suppressor gene family. The expression of PLAAT4 has been shown to induce cell death; however, the underlying mechanism remains unknown. Here, we found that RPLP0, a ribosomal protein, can interact with PLAAT4, as determined by yeast two-hybrid screening, coimmunoprecipitation, and colocalization. The level of RPLP0 was suppressed in HtTA cervical cancer cells expressing PLAAT4. In PLAAT4-expressing or RPLP0-silenced cells, decreased cell viability and cell proliferation combined with increased cell death were observed. Furthermore, the levels of cell cycle-associated proteins and anti-apoptotic proteins decreased in PLAAT4-expressing or RPLP0-silenced cells. Similar patterns of cell viability and expression levels of cell-cycle-associated proteins and apoptosis-related proteins were observed in PLAAT4-expressing and RPLP0-knockdown cells, indicating that RPLP0 deficiency might be involved in PLAAT4-mediated growth inhibition and cellular apoptosis.

Extracellular Signal-Regulated Kinase Mediates Ebastine-Induced Human Follicle Dermal Papilla Cell Proliferation.

Ebastine is a second-generation histamine H1 receptor antagonist that is used to attenuate allergic inflammation. Ebastine has also shown to affect hair loss; however, the immunoregulatory effect of ebastine cannot completely exclude the possibility of spontaneous hair regrowth in ebastine-treated mice. In this study, we examined the effects of ebastine on the growth of human follicle dermal papilla cells (HFDPC) using a WST-1 cell proliferation assay and a bromodeoxyuridine incorporation assay. Ebastine was shown to significantly increase the proliferation of HFDPC. The expression levels of cell-cycle regulatory proteins and an antiapoptotic protein were increased in ebastine-treated HFDPC. Furthermore, elevated expression levels of phospho-AKT and phospho-p44/42 extracellular signal-regulated kinase (ERK) were observed in ebastine-treated HFDPC. Ebastine-mediated HFDPC growth was completely reversed by blocking ERK kinase. The results from our present study suggest that the regulation of HFDPC proliferation by ebastine might be directly involved in hair regrowth through the ERK signaling pathway.

Elastic methyltrimethoxysilane based silica aerogels reinforced with polyvinylmethyldimethoxysilane.

Native silica aerogels are fragile and brittle, which prevents their wider utility. For designing more durable and stronger silica aerogels, polyvinylmethyldimethoxysilane (PVMDMS) polymers as effective and multifunctional reinforcing agents were used to strengthen methyltrimethoxysilane based silica aerogels (MSAs). The PVMDMS polymer, which was composed of long-chain aliphatic hydrocarbons and organic side-chain methyl and alkoxysilane groups, was integrated into silica networks via a simple sol-gel process. Compared with MSAs, PVMDMS reinforced MSAs (PRMSAs) display many fascinating characteristics. PRMSAs exhibit improved hydrophobic properties (water contact angle of 136.9°) due to abundant methyl groups in the silica networks. Benefiting from the fine integration of PVMDMS polymers into MSAs, PRMSAs show a perfectly elastic recovery property, the compressive strength of which ranges from 0.19 to 1.98 MPa. More importantly, PVMDMS polymers have successfully suppressed the growth of secondary particles. Homogeneous silica networks formed by nanoscale particles give PRMSAs a high surface area of 1039 m2 g-1. Moreover, optimized PRMSAs also exhibit a low thermal conductivity of 0.0228 W m-1 K-1 under ambient conditions, and their thermal stability reaches up to 222.3 °C in air. All the results obtained from this paper will help us to design silica aerogels.