Results 261 to 270 of about 16,681,036 (304)

Electromechanical Properties of Poly-L-Lactic Acid

Japanese Journal of Applied Physics, 1998
The electromechanical coupling coefficient, the piezoelectric constant, the elastic compliance constant and the mechanical quality factor for a poly-L-lactic acid (PLLA) plate elongated to 4 times the original length were determined by a self-resonant method. k 14=0.064, d 14=9.82×10-12 C/N, s
Tsutomu Ochiai, Eiichi Fukada
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Alopecia Induced by Poly-L-Lactic Acid Injection

Cutis
Cosmetic procedures carry inherent risks of adverse events. Though rarely reported, transient and permanent alopecia are potential complications of these procedures. We report the case of a 35-year-old woman who developed pain and patches of nonscarring alopecia with erythema and edema following aesthetic application of poly-L-lactic acid (PLLA) on the
Gabriel Lazzeri, Cortez, Karime Marques, Hassun, Luciana Ribeiro Patrício, Linhares, Maria Valéria Bussamara, Pinheiro, Verena, Florenço, Nilceo Schwery, Michalany, Ediléia, Bagatin, Rita Fernanda Cortez, de Almeida, Daniel Fernandes, Melo, Maurício Mendonça, do Nascimento   +9 more
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Optical activity in poly-l-lactic acid

Ferroelectrics, 1994
Abstract Optical activity of a helical polymer, poly-L-lactic acid, was studied by using x-rays and HAUP methods. Gyrations depend considerably on the drawing actions. From the relation between gyrations and drawing ratios, the gyration tensor components are determined as g1=(-2.7±0.5)x10−4 and g3=(8.3±0.2)x10−2.
Jinzo Kobayashi, Masaaki Ichiki, Taku Watanabe, Toru Asahi, Atsushi Oikawa, Hiro Suzuki   +5 more
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Poly-L-lactic acid: an overview.

Journal of drugs in dermatology : JDD, 2006
In August 2004, the US Food and Drug Administration approved a poly-L-lactic acid (PLLA)-based injectable medical device for restoration and/or correction of the signs of facial fat loss (lipoatrophy) in people with human immunodeficiency virus. As a result, the properties of the PLLA microparticles have received considerable interest from the medical ...
Pahala, Simamora, Wendy, Chern
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Optical activity of poly-l-lactic acid

Ferroelectrics, 1990
Abstract Simultaneous measurements of optical activity and birefringence have been made for the first time on poly-L-lactic acid (PLLA), which is a well-known piezoelectric and biodegradable polymer. Optical gyration of PLLA films, one stretched 2.5 times the other 6 times as long as the original ones, displayed different temperature dependence in the ...
Toru Asahi, Haruko Fukase, Masaaki Ichiki, Jinzo Kobayashi, Eiichi Fukada   +4 more
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Vibrational analysis of poly(L‐lactic acid)

Journal of Raman Spectroscopy, 1995
Abstract The Raman and IR spectra of poly( L ‐lactic acid) in the amorphous and semicrystalline states were recorded from 3600 to 100 cm −1 . Complete vibrational assignments are proposed. In the Raman spectra, the splittings of the
G. Kister, G. Cassanas, M. Vert, B. Pauvert, A. Térol   +4 more
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Crystallization kinetics of poly(l-lactic acid)

Polymer, 1983
Abstract The morphology and crystal growth of poly( l -lactic acid), PLLA have been studied from the melt as a function of undercooling and molecular weight using hot stage microscopy. Attention has been given to the application of growth rate equation on the growth rate data of PLLA and thus various nucleation parameters have been calculated.
Vasanthakumari, R, Pennings, AJ
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Ferroelectric Behavior in Poly-L-Lactic Acid

Japanese Journal of Applied Physics, 1996
Ferroelectric behavior was observed in poly-L-lactic acid (PLLA), though its crystal structure was previously reported to be nonpolar because the molecular chains are helical. The remanent polarization (P r) increased with increasing temperature while the coercive electric field (E c) decreased ...
Qing Yang Pan, Shigeru Tasaka Shigeru Tasaka, Norihiro Inagaki Norihiro Inagaki   +2 more
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Crystallization behavior of poly(l-lactic acid)

Polymer, 2006
Abstract The crystallization behavior of poly( l -lactic acid) was studied in the range of 80–160 °C. The peak crystallization time (τp) was defined and obtained from the crystallization isotherm measured with a differential scanning calorimeter (DSC).
Munehisa Yasuniwa, Shinsuke Tsubakihara, Koji Iura, Yoshinori Ono, Yusuke Dan, Kazuhisa Takahashi   +5 more
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Preparation of Poly (L-lactic Acid) Microsphere

Journal of Macromolecular Science, Part B, 2010
Poly (L-lactic acid) (PLLA) microspheres were prepared by a solvent evaporation method based on an oil/water emulsion. The effect of the mass ratio of PLLA and poly(vinyl alcohol) (PVA) on the formation of the microspheres was discussed, and the influence of extraction speed of dichloromethane on the microsphere morphology was also studied.
Jianpeng Zou, Jianming Ruan, Zhongcheng Zhou, Zhihua Zhou   +3 more
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