• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2295-2298
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• 2012

We describe herein a three-dimensionally diverse micropatterning of poly(lactic acid), as a biopolymer, using 1-butyl-3-methylimidazolium-based room-temperature ionic liquids (bmim-based RTILs), [bmim]X (X = $SbF_6$, $PF_6$, $NTf_2$, Cl). Utilizing the hydrophobic bmim-based RTILs, [bmim]X (X = $SbF_6$, $PF_6$, $NTf_2$) and a phase separation technique, we were able to produce white and opaque membranes with a three-dimensional structure closely packed with particles ($10-50{\mu}m$ in diameter). The particlulate structure, made by the assistance of [bmim]$NTf_2$ and DCM, interestingly transformed to a fibrous structure by using a cosolvent, e.g., DCM/$CF_3CH_2OH$. When we used an increased amount of [bmim]$NTf_2$, the particles were effectively detached and macrosized ($100-500{\mu}m$ in diameter) and the oval-shaped beads were obtained in a powder form. By varying the counter-anion type of the imidazolium-based RTIL, for example from $NTf_2^-$ to $Cl^-$, the particulate 3D-morphology was once more transformed to a porous structure. These reserch results could be potentially useful, as a method to fabricate particulate scaffolds, fibrous or porous scaffolds, and beads as a biopolymer device in diverse fields including drug delivery, tissue regeneration, and biomedical engineering.

• Journal of Forest and Environmental Science
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• v.8 no.1
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• pp.51-66
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• 1992

This study was carried out to investigate the micromorphology of vessel wall sculpture such as shape of perforation plate, perforation rim, steepness of perforation plate, occurrence of vestured pit, warty layer and ray-vessel pitting on 13 species of Fagaceae in Korea. The results were summarized as follows ; 1. In the species examined, all sample species except Fagus crenata var. multinervis have simple perforation plate. But Fagus crenata var. multinervis has simple and scalariform perforation plate (it was called to combination perforation plate) in a tree stem. 2. The shapes of perforation rim could be classified into five types; Type A without tail, Type B with small tail on both sides, Type C with long tail on both sides, Type D with tail only one side and Type E with the very short interval between perforations. Among five types, Type Band C have higer frequency of distribution than the others. 3. The steepness of perforation plate measured was about 20 degree on pore zone and 43 degree on outside parts of pore zone. 4. Species with vestured pit were Q. aliena, Q, dentata, Q. variabilis, Fagus crenata var. multinervis, Castanopsis cuspidata var sieboldii, Q. acuta, Q. stenophylla, and Q. glauca. But the extent of vesturing was very slight and vestured pits were observed mainly in ray-vessel pit of some vessel elements. 5. Species with warty layer on the inner surface wall of all vessel elements were Q. acuta, Q. stenophylla, Q. glauca, Fagus crenata var. multinervis and species with warty layer of some vessel elements were Q. aliena, Q, dentata, Q. variabilis, Castanopsis cuspidata var. sieboldii. 6. Species with palisade ray-vessel pit were Q. acuta, Q. stenophylla, Q. glauca, Castanea crenata, Castanea bungeana, Q. aliena, Q. serrata, Q. mongolica, and species with scalariform ray-vessel pit was Fagus crenata var. multinervis and species with oval ray-vessel pit were Q, dentata, Castanopsis cuspidata var sieboldii.

• Korean Journal of Plant Taxonomy
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• v.38 no.4
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• pp.509-522
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• 2008

한국산 가막사리속(Bidens L.)에 포함된 10분류군(8종 2변종)의 수과형태를 연구하기 위하여 입체현미경과 주사전자현미경을 이용하여 관찰하였다. 연구된 가막사리속에서 까끄라기를 제외한 수과의 크기는 $3.0-19.5{\times}0.7-2.6 mm$이다. 관모는2-4개의 까끄라기로 구성되어 있고, 까끄라기의 길이는 2.2-5.6 mm이다. 강모의 배열은 1-3열이었다. 수과의 다형화가 6개의 분류군(B. bipinnata, B. biternata, B. frondosa, B. parviflora, B. pilosa var. pilosa, B. tripartita var. tripartita)에서 확인되었다. 수과의 형태와 까끄라기의 수에 의해 4가지 유형으로 구분되었다. - Type A: 장타원형이고, 까끄라기 수는 2개(B. parviflora); Type B: 장타원형이고, 까끄라기 수는 3개 이상(B. bipinnata, B. biternata, B. pilosa var. pilosa, B. pilosa var. minor) Type C: 도란형이고, 까끄라기의 수는 2개(B. frondosa, B. radiata var. radiata, B. radiata var. pinnatifida, B. tripartita var. tripartita); Type D: 도란형이고, 까끄라기의 수는 3개 이상(B. cernua). 까끄라기의 강모 표면무늬는 3가지 즉 나선상, 평활상, 불규칙한 직선형으로 나타났다. 수과의 표면은 각피층이 발달한 다각형, 평활상 그리고 굴곡형으로 나타났다. 수과형질의 분류학적 적용에 대하여 간략하게 토의하였다. 수과형질을 바탕으로 한국산 가막사리속 분류군에 대한 검색표를 제시하였다.