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Structure and Properties of Polyimide (BTDA-TDI/MDI co-polyimide) Fibers Obtained by Wet-Spinning
Hong Bing Xiang,Zhong Huang,Li Qi Liu,Lei Chen,Jing Zhu,Zu Ming Hu,Jun Rong Yu 한국고분자학회 2011 Macromolecular Research Vol.19 No.7
BTDA-TDI/MDI (P84, synthesized by the condensation of 2,4-diisocyanato-1-methylbenzene and 1,1' -methylenebis(4-isocyanatobenzene) with 5,5'-carbonylbis(l,3-isobenzofurandione)) co-polyimide fibers were prepared by wet-spinning. The basic spinning conditions were found from the studies of dope viscosity, ternary phase diagrams, coagulation value, and precipitation value. The effect of the coagulation bath composition on the morphology of as-spun fibers was investigated and a theoretical approach was used to understand the coagulation phenomena. Scanning electron microscopy (SEM) showed that the cross-sectional shape of the fiber deviated more from an ellipse shape with the increasement of N-methyl-2-pyrrdidinone (NMP) content. The surface and cross section morphology of the as-spun fibers was also analyzed by the rate of diffusion and phase separation. The as-spun fibers were treated in heating tubes without drawing at different temperatures. The gravimetric analysis spectra showed that the BTDA-TDI/MDI co-polyimide fibers, which had been heat treated at 350 and 400 ℃, possessed better thermal properties than the as-spun fibers, a large weight loss was observed only above 550 ℃. Heat treatment of the fibers resulted in relatively high tensile strength and modulus. The fibers spun in Bath C (70/30, NMP/water, wt/wt)and Bath D (80/20, NMP/water, wt/wt) showed better thermal properties and higher tensile strength.
Chen, Zhi Hong,Kim, Chanhoi,Zeng, Xiang-bing,Hwang, Sun Hye,Jang, Jyongsik,Ungar, Goran American Chemical Society 2012 Langmuir Vol.28 No.43
<P>A combination of experimental methods, including transmission and grazing incidence small-angle X-ray scattering (SAXS and GISAXS), small-angle neutron scattering (SANS), transmission electron microscopy (TEM), dynamic light scattering (DLS), and N<SUB>2</SUB> adsorption–desorption isotherms, was used to characterize SiO<SUB>2</SUB>/TiO<SUB>2</SUB> hollow nanoparticles (HNPs) of sizes between 25 and 100 nm. In the analysis of SAXS, SANS, and GISAXS data, the decoupling approximation and the Percus–Yevick structure factor approximation were used. Brunauer–Emmett–Teller, <I>t</I>-plot, and a spherical pore model based on Kelvin equation were applied in the treatment of N<SUB>2</SUB> isotherms. Extracted parameters from the scattering and TEM methods are the average outer and inner diameters and polydispersity. Good agreement was achieved between different methods for these extracted parameters. Merits, advantages, and disadvantages of the different methods are discussed. Furthermore, the combination of these methods provided us with information on the porosity of the shells of HNPs and the size of intrawall pores, which are critical to the applications of HNPs as drug delivery vehicles and catalyst supports.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/langd5/2012/langd5.2012.28.issue-43/la302236u/production/images/medium/la-2012-02236u_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/la302236u'>ACS Electronic Supporting Info</A></P>
( Qi Fan ),( Yuan-bing Wang ),( Guo-dong Zhang ),( De-xiang Tang ),( Hong Yu ) 한국균학회 2021 Mycobiology Vol.49 No.2
A new fungus, Ophiocordyceps alboperitheciata, parasitic on the larva of Noctuidae (Lepidoptera) was identified from a survey of entomopathogenic fungi in Kunming Wild Duck Forest Park, Yunnan Province, China. It can be primarily distinguished from relatives by its longer fertile parts, sterile tips, superficial perithecia, narrower asci, and smaller septa of ascospores. As revealed from phylogenetic analyses inferred from nrSSU, nrLSU, tef-1α, rpb1, and rpb2 sequence data, O. alboperitheciata belongs to the Hirsutella citriformis clade in the genus Ophiocordyceps of Ophiocordycipitaceae, and forms a separated clade from other related species. The uniqueness of the taxon is significantly evidenced by both molecular phylogeny and morphology. Furthermore, the interspecific relationships in the H. citriformis clade are discussed.
Fu, Qiang,Wang, Bai-Chen,Jin, Xiang,Li, Hong-Bing,Han, Pei,Wei, Kai-Hua,Zhang, Xue-Min,Zhu, Yu-Xian Korean Society for Biochemistry and Molecular Biol 2005 Journal of biochemistry and molecular biology Vol.38 No.6
Proteins accumulated in dry, stratified Arabidopsis seeds or young seedlings, totaled 1100 to 1300 depending on the time of sampling, were analyzed by using immobilized pH gradient 2-DE gel electrophoresis. The molecular identities of 437 polypeptides, encoded by 355 independent genes, were determined by MALDI-TOF or TOF-TOF mass spectrometry. In the sum, 293 were present at all stages and 95 were accumulated during the time of radicle protrusion while another 18 appeared in later stages. Further analysis showed that 226 of the identified polypeptides could be located in different metabolic pathways. Proteins involved in carbohydrate, energy and amino acid metabolism constituted to about 1/4, and those involved in metabolism of vitamins and cofactors constituted for about 3% of the total signal intensity in gels prepared from 72 h seedlings. Enzymes related to genetic information processing increased very quickly during early imbibition and reached highest level around 30 h of germination.
Liu, Yang-Chen,Zhou, Shao-Bing,Gao, Fei,Ye, Hong-Xun,Zhao, Ying,Yi, Xiao-Xiang,Huang, Xin-En,Xiang, Jin Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.4
Objective: To compare the efficacy and complications of chemotherapy and late course three-dimensional conformal radiotherapy (3DCRT) in treating patients with stage III non-small cell lung cancer (NSCLC). Patients and Methods: All patients were divided into two groups: to receive chemotherapy and late course 3DCRT (3DCRT group), or chemotherapy and conventional fraction radiation (control group). In the 3DCRT-group, patients were given 6~15 MV X-rays with a total dose of 40 Gy, followed by 3DCRT, 2.5 Gy~3.0 Gy per fraction, 1 fraction/every day, total 68 Gy~70 Gy; in the control group, with conventional fraction radiation the total dose was 64~66 Gy. The chemotherapy regimen in both cases was EP (VP-16 and DDP). Results: Sixty four patients with stage III NSCLC were divided into two groups: 32 patients into 3DCRT, 32 into the control group. One and 2-year survival rates in 3DCRT and control group were 87.5%, 56.3%mad 65.6%, 34.4%, respectively (P<0.05); local control rates were 90.6%, 81.3% and 65.6%, 53.1%, respectively (P<0.05). Conclusion: Chemotherapy and late course 3DCRT is associated with improved survival rate in patients with stage III NSCLC with good tolerability.
Liao, Linda M,Friesen, Melissa C,Xiang, Yong-Bing,Cai, Hui,Koh, Dong-Hee,Ji, Bu-Tian,Yang, Gong,Li, Hong-Lan,Locke, Sarah J,Rothman, Nathaniel,Zheng, Wei,Gao, Yu-Tang,Shu, Xiao-Ou,Purdue, Mark P BMJ Publishing Group Ltd 2014 Occupational and environmental medicine Vol.71 No.suppl1
<P><B>Objectives</B></P><P>Epidemiologic studies of occupational lead exposure have suggested increased risks of cancers of the brain, kidney, lung, meninges, and stomach; however, the totality of the evidence is inconsistent. To clarify whether lead is a carcinogen, we investigated the relationship between occupational lead exposure and risks of these five cancer sites in two prospective cohort studies in Shanghai, China.</P><P><B>Method</B></P><P>Annual job/industry-specific estimates of lead fume and lead dust exposure were derived from a statistical model that combined expert ratings of lead intensity with inspection measurements collected by the Shanghai Centre for Disease Control and Prevention. The job/industry estimates were applied to the lifetime work histories of subjects from the Shanghai Women’s Health Study (73 363 participants) and the Shanghai Men’s Health Study (61 379 participants) to estimate cumulative exposure to lead dust and lead fume. Cohort-specific relative hazard rate ratios (RRs) and 95% confidence intervals (CI) were estimated using Cox proportional hazards regression models and then pooled using a random effects meta-analysis model.</P><P><B>Results</B></P><P>We observed a statistically significant increased risk of meningioma among individuals with estimated occupational exposure to lead dust or fumes (RR=2.4, 95% CI:1.1–5.0), and in particular among those with an above-median cumulative exposure to dust or fumes (RR=3.1, 95% CI:1.3–7.4). We observed suggestive associations with lead exposure for cancers of the kidney (RR=1.4, 95% CI:0.9–2.3) and brain (RR=1.8, 95% CI:0.7–4.8), and null findings for cancers of the lung and stomach.</P><P><B>Conclusions</B></P><P>Our findings provide additional evidence that occupational lead exposure increases risk of meningioma.</P>