The effects of various additives: poly(D‐lactic acid) (PDLA), talc, fullerene C60, montmorillonite, and various polysaccharides, on the non‐isothermal crystallization behavior of poly(L‐lactic acid) ...(PLLA), during both the heating of melt‐quenched films from room temperature, and the cooling of as‐cast films from the melt, was investigated. When the melt‐quenched PLLA films were heated from room temperature, the overall PLLA crystallization was accelerated upon addition of PDLA or the stereocomplex crystallites formed between PDLA and PLLA, the mixtures containing PDLA, and the mixture of talc and montmorillonite. No significant effects on the overall PLLA crystallization were observed for talc, C60, montmorillonite, and the mixtures containing C60. Such rapid completion of the overall PLLA crystallization upon addition of the aforementioned additives can be ascribed to the increased density (number per unit volume or area) of PLLA spherulites. When the as‐cast PLLA films were cooled from the melt, the overall PLLA crystallization completed rapidly, upon addition of PDLA, talc, C60, montmorillonite, and their mixtures. Such rapid overall PLLA crystallization is attributable to the increased density of the PLLA spherulites and the higher nucleation temperature for PLLA crystallization. In contrast, the addition of various polysaccharides has no significant effect, or only a very small effect, on the overall PLLA crystallization during heating from room temperature or during cooling from the melt. This finding means that the polysaccharides can be utilized as low‐cost fillers for PLLA‐based materials, without disturbing the crystallization of the PLLA. The effect of additives in accelerating the overall PLLA crystallization during cooling from the melt, decreased in the following order: PDLA > talc > C60 > montmorillonite > polysaccharides.
Polarization optical photomicrographs of pure PLLA, and the PLLA‐F film, with the fullerene additive, during cooling from the melt (Process IIB). Both of the photomicrographs were taken at 120 °C.
We have previously shown that cloned rat multidrug resistance-associated protein 3 (Mrp3) has the ability to transport organic anions such as 17β-estradiol 17-β-d-glucuronide (E217βG) and has a ...different substrate specificity from MRP1 and MRP2 in that glutathione conjugates are poor substrates for Mrp3 (Hirohashi, T., Suzuki, H., and Sugiyama, Y. (1999) J. Biol. Chem. 274, 15181–15185). In the present study, the involvement of Mrp3 in the transport of endogenous bile salts was investigated using membrane vesicles from LLC-PK1 cells transfected with rat Mrp3 cDNA. The ATP-dependent uptake of 3Htaurocholate (TC), 14Cglycocholate (GC), 3Htaurochenodeoxycholate-3-sulfate (TCDC-S), and 3Htaurolithocholate-3-sulfate (TLC-S) was markedly stimulated by Mrp3 transfection in LLC-PK1 cells. The extent of Mrp3-mediated transport of bile salts was in the order, TLC-S > TCDC-S > TC > GC. The Km andVmax values for the uptake of TC and TLC-S wereKm = 15.9 ± 4.9 μm andVmax = 50.1 ± 9.3 pmol/min/mg of protein and Km = 3.06 ± 0.57 μm andVmax = 161.9 ± 21.7 pmol/min/mg of protein, respectively. At 55 nm3HE217βG and 1.2 μm3HTC, the apparent Km values for ATP were 1.36 and 0.66 mm, respectively. TC, GC, and TCDC-S inhibited the transport of 3HE217βG and 3HTC to the same extent with an apparent IC50 of ∼10 μm. TLC-S inhibited the uptake of 3HE217βG and 3HTC most potently (IC50 of ∼1 μm) among the bile salts examined, whereas cholate weakly inhibited the uptake (IC50 ∼75 μm). Although TC and GC are transported by bile salt export pump/sister of P-glycoprotein, but not by MRP2, and TCDC-S and TLC-S are transported by MRP2, but not by bile salt export pump/sister of P-glycoprotein, it was found that Mrp3 accepts all these bile salts as substrates. This information, together with the finding that MRP3 is extensively expressed on the basolateral membrane of human cholangiocytes, suggests that MRP3/Mrp3 plays a significant role in the cholehepatic circulation of bile salts.
Thin films of aluminium silicon oxynitride have been deposited on conducting (100) silicon wafers by filtered arc deposition (FAD) under nitrogen and/or oxygen gas flow. The influence of the N
2/O
2 ...flow ratio on the crystal structure, optical and mechanical properties has been investigated. The results of X-ray diffraction showed that the film structure comprised of an AlN crystallite with amorphous Si
3N
4 and SiO
x
. The optical properties over the range of 350–800 nm were measured using spectroscopic ellipsometry and found to be strongly dependent on N
2/O
2 flow ratio. The refractive index values of the films were measured to be in the range of 2.2–1.64 at a wavelength of 670 nm for oxygen flow range of 0–100%. The hardness of the films was found to be strongly dependent on the oxygen content in the film. The hardness range of the films was between 10 and 22 GPa and for the stress between 0.3 and 1.2 GPa.
Radio frequency (rf) inductively coupled thermal plasma (ICTP) was used to fabricate fullerenes (C
60,C
70, etc.) by direct evaporation of carbon powder injected into the plasma. Spectroscopic ...observation of the plasma was made for molecular band spectra of C
2 and atomic lines of C. The formation of fullerenes C
60 and C
70 as well as higher fullerenes were checked and recognized by high performance liquid chromatography (HPLC) and time-of-flight mass spectrometer (TFMS). The suitable conditions for the synthesis of fullerenes within the experimental conditions adopted were 10-kPa plasma pressure, with a considerably higher flow rate of approximately 150 l/min for mixed-gas condition of Ar, He and CO
2, with carbon powder of average diameter 20 μm. The results showed that the productivity of fullerenes has a relation to the intensity of C
2 molecular and C atomic spectra from the induction plasma. Mixing of Si with C particles has a kind of role in enhancing the synthesis rate of fullerenes C
60, as well as the higher order fullerenes.
The radio frequency inductively coupled thermal plasma (RF-ICTP) was used to fabricate fullerenes (C
60,C
70 etc.) by direct evaporation of C or C-Si mixed powder by high enthalpy of the plasma. ...Spectroscopic observation of the plasma was made for molecular band spectra of C
2 and atomic lines of C. The formation of fullerenes C
60 and C
70 as well as higher fullerenes was checked and recognized by TFMS (Time of Flight Mass Spectrometer). The results showed that Si mixing into C powder could increase the radiation intensity of C
2 molecular as well as C atomic spectrums and decrease the plasma temperature, and showed a higher synthesis rate of fullerenes including higher order one, compared to pure C powder case. Discussions were made about the effects of O
2 inclusion (from air leak) as well as Si injection on the concentrations of the C particle system (C, C
2, C
3, C
4 etc.), and the influence of Si injection on the plasma temperature was also involved.
PDF
