Here we describe the synthesis of polyurethane (PU)-based energetic nanocomposites loaded with nano-aluminum (n-Al) particles. The energetic nanocomposite was prepared by polyurethane reaction of poly(glycidyl azide-co-tetramethylene glycol) (PGT) prepolymers and IPDI/N-100 isocyanates with simultaneous catalyst-free azide-alkyne Click reaction in the presence of n-Al. Initial study carried out with various n-Al/fluorinated PGT blends and demonstrated the potential of fluorinated PGT prepolymer for an energetic PU matrix.
View Article and Find Full Text PDFPolyurethane (PU) foams with controlled porosity and pore structure are prepared via judicious study on expanding process parameters for thermoplastic expandable microspheres which are compatible with PU synthetic process. Thermal and mechanical properties of PU foams are found to be generally governed by amount of the porosity. Thermal conductivity of PU foams with controlled porosity is measured at 30 °C with transient hot bridge method.
View Article and Find Full Text PDFThis paper presents a comparative study on thermal conductivity of PU composites containing open-cell nano-porous silica aerogel and closed-cell hollow silica microsphere, respectively. The thermal conductivity of PU composites is measured at 30 degrees C with transient hot bridge method. The insertion of polymer in pores of silica aerogel creates mixed interfaces, increasing the thermal conductivity of resulting composites.
View Article and Find Full Text PDFAlthough CpG methylation is thought to be a negative regulator of gene transcription, its relationship with cytokine expression remains unclear. Interleukin (IL)-4 and interferon (IFN)-gamma are major cytokines that affect the differentiation of naïve CD4+ T lymphocytes into the Th1 and Th2 lineage. We used bisulfite deoxyribonucleic acid modification and sequencing to examine the relationship between CpG methylation and IL-4 and IFN-gamma gene expression before and after allergen stimulation in human CD4+ T lymphocytes from sensitized hosts.
View Article and Find Full Text PDFBackground: Despite many reports about the involvement of DNA methyltransferases (DNMTs) in human cancers, including nonsmall cell lung cancer (NSCLC), the clinicopathologic significance of DNMTs in primary NSCLC remains to be elucidated.
Methods: The relation between the mRNA levels of DNMTs (1 and 3b) and the promoter methylation of the p16, RARbeta2, H-cadherin, GSTP1, RIZ, and FHIT genes and the clinicopathologic features in 102 fresh-frozen tissues and paraffin blocks were retrospectively studied. The mRNA levels of the DNMTs were assessed via semiquantitative reverse-transcription polymerase chain reaction (RT-PCR), and the methylation status of the CpG islands were determined by methylation-specific PCR.
Despite advances in the detection and treatment of lung cancer, the prognosis for patients with lung cancer is poor, partly as a result of recurrences. We retrospectively analyzed the relationship between recurrence and survival in patients with non-small cell lung cancers (NSCLC), and the promoter methylation of p16, GSTP1, FHIT, H-cadherin, and RARbeta2 genes to identify a prognostic molecular marker associated with the recurrence of NSCLC. Methylation status from 335 paraffin blocks was determined by methylation-specific PCR.
View Article and Find Full Text PDFBackground: Abnormalities in the H-cadherin gene have been reported in several human malignancies, including nonsmall cell lung carcinoma (NSCLC). Aberrant methylation of the H-cadherin promoter also has been reported in NSCLC, but its clinical significance remains to be elucidated.
Methods: The authors studied H-cadherin methylation in 305 patients with NSCLC to gain a further understanding of the clinicopathologic and prognostic significance of H-cadherin methylation in patients with NSCLC.
Purpose: To investigate whether the promoter hypermethylation of retinoic acid receptor beta 2 (RARbeta2) is associated with the development of second primary lung cancers (SPLCs) differentially according to smoking status in primary non-small-cell lung cancer (NSCLC).
Patients And Methods: We retrospectively analyzed the relationship between RARbeta2 methylation and the SPLC development in a total of 342 NSCLCs. The methylation status of RARbeta2 was determined by using methylation-specific polymerase chain reaction.
Fragile histidine triad (FHIT) gene plays an important role in the pathogenesis of lung cancer. However, the clinicopathological significance of CpG island hypermethylation of FHIT gene in non-small cell lung cancer (NSCLC) remains to be elucidated. We studied FHIT methylation in 254 NSCLCs in order to further understand the clinicopathological and prognostic significance of FHIT methylation in NSCLC.
View Article and Find Full Text PDFPurpose: The aim of this study was to identify tumor-specific methylation in bronchial lavage for the early detection of non-small-cell lung cancer (NSCLC) by differentiating the age-related methylation from the tumor-specific methylation in NSCLC.
Patients And Methods: Eighty-five NSCLC patients and 127 cancer-free subjects participated in this study. Aberrant methylation at the promoters of the p16, Ras association domain family 1A (RASSF1A), fragile histidine triad (FHIT), H-cadherin, and retinoic acid receptor beta (RARbeta) genes were evaluated in the resected tumor tissues and bronchial lavage samples of NSCLC patients and in the bronchial lavage samples of cancer-free subjects by methylation-specific polymerase chain reaction.
Lithium has been demonstrated to increase neurogenesis in the dentate gyrus of rodent hippocampus. The present study was undertaken to investigate the effects of lithium on the proliferation and differentiation of rat neural progenitor cells in hippocampus both in vitro and in vivo. Lithium chloride (1-3 mM) produced a significant increase in the number of bromodeoxyuridine (BrdU)-positive cells in high-density cultures, but did not increase clonal size in low-density cultures.
View Article and Find Full Text PDFRecently, several groups have reported that Ras association domain family 1 (RASSF1A) interacts with Ras and mediates Ras-dependent apoptosis. However, the mechanism by which RASSF1A plays a role as a tumor suppressor in human cancer is unclear. In this study, we investigated the relationship between the RASSF1A methylation and K-ras mutation and their effects on patient's survival in 242 primary non-small cell lung cancers (NSCLCs) to understand the role of RASSF1A in Ras-mediated oncogenic transformation.
View Article and Find Full Text PDFCigarette smoking is the most common cause of lung cancer. The greatest risk of lung cancer is among those who started smoking early in life and continued throughout their lives. However, the molecular mechanisms responsible for the susceptibility to lung cancer in the young smoker are not clear.
View Article and Find Full Text PDFWe measured the temporal and spatial profiles of neural precursor cells, hippocampal long-term potentiation (LTP), and signaling molecules in neurogenesis-induced adult rats. Chronic lithium treatment produced a significant 54% and 40% increase in the numbers of bromodeoxyuridine [BrdU(+)] cells after 12 h and 28 days, respectively, after treatment completion in the dentate gyrus (DG). Both LTP obtained from slices perfused with artificial cerebrospinal fluid (ACSF-LTP) and LTP recorded in the presence of bicuculline (bicuculline-LTP) were significantly greater in the lithium group than in the saline controls.
View Article and Find Full Text PDFBiochem Biophys Res Commun
April 2003
We investigated the hippocampal long-term potentiation (LTP), neurogenesis, and the activation of signaling molecules in the 20-month-old aged rats following chronic lithium treatment. Chronic lithium treatment produced a significant 79% increase in the numbers of BrdU(+) cells after treatment completion in the dentate gyrus (DG). Both LTP obtained from slices perfused with artificial cerebrospinal fluid (ACSF-LTP), and LTP recorded in the presence of bicuculline (bicuculline-LTP) were significantly greater in the lithium group than in the saline controls.
View Article and Find Full Text PDFBiochem Biophys Res Commun
October 2002
In an attempt to identify the functions of neural cell adhesion molecule (NCAM) and tissue plasminogen activator (tPA) in hippocampal synaptic plasticity, we investigated the relationship between the two molecules by focusing on mitogen-activated protein kinase (MAPK), an essential enzyme in this process. NCAM clustering in cultured hippocampal neurons transiently induced MAPK within 10min. Moreover, soluble NCAM also induced a Ras-dependent MAPK activation.
View Article and Find Full Text PDFTo investigate if estrogen modulates long-term potentiation (LTP) via mitogen-activated protein kinase (MAPK) activation, in vitro hippocampal slices were used to induce LTP through extracellular field recordings. Slices perfused with 17beta-estradiol exhibited a significant enhancement of LTP (224+/-19%) compared with LTP in control slices (157+/-9%). In the presence of PD098059, 17beta-estradiol still produced a significant magnitude of LTP (131+/-7%), revealing the existence of p-MAPK-independent LTP mediated by 17beta-estradiol.
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