<i>Prorocentrum shikokuense</i> Hada and <i>P. donghaiense</i> Lu are junior synonyms of <i>P. obtusidens</i> Schiller, but not of <i>P. dentatum</i> Stein (Prorocentrales, Dinophyceae)

Shin, Hyeon Ho,Li, Zhun,Mertens, Kenneth Neil,Seo, Min Ho,Gu, Haifeng,Lim, Weol Ae,Yoon, Yang Ho,Soh, Ho Young,Matsuoka, Kazumi Elsevier 2019 Harmful algae Vol.89 No.-

<P><B>Abstract</B></P> <P>In Japanese, Chinese and Korean coastal waters, recurrent blooms of a small, elongate <I>Prorocentrum</I> species have been observed in recent years. In previous studies, this species has been respectively identified as <I>P. shikokuense</I>, <I>P. donghaiense</I> and <I>P. dentatum</I>, despite morphological similarity and identical rDNA sequences. To resolve the confusion, morphological features, including the architectural details of the periflagellar area, were examined and ribosomal DNA (rDNA) sequences were obtained from specimens collected from the East China Sea and Korean coast, and a strain established in the waters off the Canary Islands of Spain. In addition, the descriptions of the three species and allied species were reviewed. Morphological observations and a phylogeny based on the SSU, ITS region and LSU rDNA sequences revealed that the previously confused species and our studied strains are conspecific and that the morphology of strains identified as <I>P. dentatum</I> in the phylogenetic trees does not coincide with <I>P. dentatum sensu stricto</I>. The confusion can be traced back to Dodge (1975, p. 116), who considered <I>P. veloi, P. monacense</I> and <I>P. obtusidens</I> as junior heterotypic synonyms of <I>P. dentatum</I>. However, Dodge’s <I>P. dentatum</I> are closer to <I>P. obtusidens sensu stricto</I>, rather than <I>P. dentatum sensu stricto</I>. <I>P. obtusidens sensu stricto</I> can be distinguished from <I>P. dentatum sensu stricto</I> by its relatively small size, parallel sides towards the anterior and a blunt anterior extension on one side. This indicates that <I>P. obtusidens</I> should not be considered a synonym of <I>P. dentatum sensu stricto</I>. In addition, a comparison of the original descriptions of <I>P. obtusidens</I> and allied species allowed to conclude that small, elongate <I>Prorocentrum</I> from Japanese, Chinese and Korean coastal waters previously identified as <I>P. shikokuense</I>, <I>P. donghaiense</I>, <I>P. dentatum sensu</I> Yoo and Lee (1986) and the specimens studied herein, which share identical rDNA sequences, morphologically coincide with <I>P. obtusidens.</I> Therefore, it is proposed that <I>P. shikokuense</I> and <I>P. donghaiense</I> should be regarded as junior synonyms of <I>P. obtusidens.</I> </P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Prorocentrum shikokuense</I> Hada, <I>P. donghaiense</I> Lu and <I>Prorocentrum obtusidens</I> Schiller are conspecific. </LI> <LI> <I>Prorocentrum obtusidens</I> is a senior to <I>P. shikokuense</I> and <I>P. donghaiense</I>. </LI> <LI> <I>Prorocentrum obtusidens</I> is a separate species from <I>P. dentatum sensu stricto</I>, <I>P. veloi</I> and <I>P. monacense</I>. </LI> <LI> The periflagellar area of <I>Prorocentrum obtusidens</I> consists of seven platelets bearing a wing-like structure and two platelets without a wing-like structure, one flagellar pore and one accessory pore. </LI> </UL> </P>

Seasonal production of dinoflagellate cysts in relation to environmental characteristics in Jinhae-Masan Bay, Korea: One-year sediment trap observation

Shin, Hyeon Ho,Li, Zhun,Lim, Dhongil,Lee, Kyun-Woo,Seo, Min Ho,Lim, Weol Ae Academic Press in association with the Estuarine a 2018 Estuarine, coastal and shelf science Vol.215 No.-

<P><B>Abstract</B></P> <P>To investigate dinoflagellate cyst production and seasonality in relation to major environmental factors, such as water temperature, salinity, chlorophyll-<I>a</I> (chl-<I>a</I>) and dissolved nutrients, and to propose dinoflagellate cysts as possible biological indicators for the reconstruction of past environmental conditions, a sediment trap study was conducted for one year, from March 2011 to February 2012, in Jinhae-Masan Bay, Korea. Marked increases in dinoflagellate cyst production were documented in Jinhae-Masna Bay during two distinct seasons (summer and late autumn) characterized by different environmental conditions. Summer (July and August) was characterized by relatively high water temperature, dissolved inorganic nitrogen (DIN), and chl-<I>a</I> concentrations and low salinity, whereas late autumn (November and December) exhibited high dissolved inorganic phosphorus, low water temperature and high salinity, compared to those of the summer. Fourteen dinoflagellate cyst taxa were identified. These assemblages were dominated by <I>Brigantedinium</I> species (round brown cyst), cysts of <I>Scrippsiella</I> species, <I>Spiniferites</I> species and cysts of <I>Alexandrium</I> species (ellipsoidal cyst). The total flux of dinoflagellate cysts ranged from 781 cysts m <SUP>−2</SUP> day <SUP>−1</SUP> to 5602 cysts m <SUP>−2</SUP> day <SUP>−1</SUP>, and the production of autotrophic dinoflagellate cysts was mainly restricted to the warmest months (July–September) and autumn. Multivariable analysis revealed that the production of major dinoflagellate cysts, excluding those of <I>Brigantedinium</I> species, can be enhanced by environmental conditions during summer in Jinhae-Masan Bay. In particular, the increased production of cysts of <I>Scrippsiella</I> species was related to increased water temperature, and the increased production of <I>Spiniferites</I> species was associated with lower salinity. Two peaks in cyst production of <I>Alexandrium</I> species in August and November corresponded with significant increases in DIN and DIP; however, no significant relationship was found between the production of <I>Brigantedinium</I> species and environmental factors in Jinhae-Masan Bay. These results suggest that the cysts of <I>Scrippsiella</I> species, <I>Spiniferites</I> species and cysts of <I>Alexandrium</I> species present in sediment samples from Jinhae-Masan Bay can be used as biological indicators to reconstruct past environmental conditions involving relatively high water temperature, low salinity and enhanced nutrient level.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Sediment trap study provides reliable information for dinoflagellate cyst production related to environmental conditions. </LI> <LI> Cysts of <I>Scrippsiella</I> species, <I>Spiniferites</I> species and cysts of <I>Alexandrium</I> species are most abundant in the warmest months. </LI> <LI> Cysts of <I>Scrippsiella</I> species, <I>Spiniferites</I> species and cysts of <I>Alexandrium</I> species can be used as biological indicators. </LI> </UL> </P>

Cyst-motile stage relationship, morphology and phylogeny of a new chain-forming, marine dinoflagellate Grammatodinium tongyeonginum gen. & sp. nov. from Korea

Li, Zhun,Oh, Seok Jin,Park, Jong-Woo,Lim, Weol-Ae,Shin, Hyeon Ho John Wiley Sons Ltd 2017 Phycologia Vol.56 No.4

<P>A new phototrophic dinoflagellate, Grammatodinium tongyeonginum gen. & sp. nov., was established by incubating resting cysts collected from surface sediment samples from Tongyeong coastal area, Korea. The resting cysts were ovoid with a large reddish pigment body and surrounded with a thick mucous layer that incorporated attached detritus particles. The vegetative cells were 24.6-40.9 mu m long and 16.4-27.3 mu m wide. The cell surface was covered with prominent longitudinal equidistant furrows. The cingulum was narrow and descended two to eight times its width. The nucleus was located at the central part of the epicone. The peripheral chloroplasts were usually granular and yellow-green in culture and were distributed along the rim of the cingulum. The horseshoe-shaped apical groove ran from the end of the sulcal extension anticlockwise around the apex. The distal end of the apical groove was located next to the extension of the sulcus and more to the ventral side than the proximal end. Molecular phylogenetic analysis using small subunit ribosomal DNA (SSU rDNA) gene sequences revealed that G. tongyeonginum was allied with the Cucumeridinium species. Large subunit ribosomal DNA (LSU rDNA) sequences revealed that G. tongyeonginum formed a clade distantly related to the other genera of Gymnodiniales. The combination of morphological characteristics with molecular phylogenies distinguished the present species from other genera within Gymnodiniales.</P>

Synthesis and Characterization of Novel Polyimides Derived from 2,2’-Bis[4-(6-amino-3-pyridinoxy) phenyl] Propane

Zhun Li,Yu Zhao,Ying Wang,Shaomin Zhu 한국고분자학회 2020 폴리머 Vol.44 No.2

A novel pyridine-containing aromatic diamine monomer, 2,2′-bis[4-(6-amino-3-pyridinoxy) phenyl] propane, was synthesized through nucleophilic substitution reaction. A series of polyimides (PIs) were obtained by the polycondensation reaction of synthesized monomer with four commercial dianhydrides. The structure and properties of the resulting PIs were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetric analysis, dynamic mechanical thermal analysis, thermogravimetric analysis, and X-ray diffraction. The PIs exhibited good thermal stability with glass transition temperature of 231 to 303℃ by DSC and 205 to 274℃ by DMA. The temperature at 5% weight loss was 478 to 501℃ in nitrogen atmosphere, and the residual mass range at 800℃ was 42-55%. The excellent mechanical properties included tensile strength of 98-102 MPa, elongation at break of 6-18%, and tensile modulus of 2.8- 3.0 GPa. The cut-off wavelength ranged from 391-440 nm, indicating that the resulting PIs had desirable optical performance.

TSN을 이용한 도로 감시 카메라 영상의 강우량 인식 방법

Li Zhun,현종환(Jonghwan Hyeon),최호진(Ho-Jin Choi) 한국대기환경학회 2018 한국대기환경학회지 Vol.34 No.5

Morphology and phylogeny of a new woloszynskioid dinoflagellate <i>Tovellia paldangensis</i> sp. nov. (Dinophyceae)

Li, Zhun,Shin, Hyeon Ho,Han, Myung-Soo Informa UK (TaylorFrancis) 2015 Phycologia Vol.54 No.1

Brigantedinium majusculum is the cyst of Protoperidinium sinuosum (Protoperidiniaceae, Dinophyceae)

Li, Zhun,Matsuoka, Kazumi,Shin, Hyeon Ho,Kobayashi, Satori,Shin, Kyungsoon,Lee, TaeHee,Han, Myung-Soo BLACKWELL SCIENTIFIC PUBLICATIONS 2015 Phycologia Vol.54 No.5

북한강 수계 조류대발생 원인종 남조 Anabaena의 분자계통학적 검토

이준 ( Zhun Li ),한명수 ( Myung Soo Han ),황수옥 ( Su Ok Hwang ),변명섭 ( Myeong Seop Byeon ),황순진 ( Soon Jin Hwang ),김백호 ( Baik Ho Kim ) 한국하천호수학회 2013 생태와 환경 Vol.46 No.2

Between May and August 2012, a massive cyanobacterial bloom with Anabaena has been occurred throughout the North Han River. Sampling was conducted at one station on each lake, L. Uham, L. Cheongpyung, and L. Paldang, where occurred a dense bloom, in 13 July. According to the microscopic examination, the blooms was dominated by one specific filamentous cyanobacterium Anabaena and other phytoplankton. Morphologically, previous literature proven that this Anabaena species is A. crassa (Lemmermann) Komark.-Legn. & Cronberg. However, identification of species in a mixed population is complicated due to limited morphological differences. Therefore, with live sample including trichome, akinete and heterocyst, the sequences of 16S rRNA gene of Anabaena isolates were cloned and analyzed, and three 16S rRNA gene sequences of 1188~1520 bp in length were obtained. It was shown from the homologous analysis results that the obtained 16S rRNA sequences were highly homologous to the relevant sequences of A. crassa in GenBank. The 16S rRNA sequences of 63 species were retrieved from GenBank, and the phylogenetic tree was constructed by using these sequences.

Study of Thermal Stability of Ni Silicide using Ni-V Alloy

Zhun Zhong,Soon-Young Oh,Won-Jae Lee,Ying-Ying Zhang,Soon-Yen Jung,Shi-Guang Li,Ga-Won Lee,왕진석,이희덕,Yeong-Cheol Kim 한국전기전자재료학회 2008 Transactions on Electrical and Electronic Material Vol.9 No.2

In this paper, thermal stability of Nickel silicide formed on p-type silicon wafer using Ni-V alloy film was studied. As compared with pure Ni, Ni-V shows better thermal stability. The addition of Vanadium suppresses the phase transition of NiSi to NiSi₂ effectively. Ni-V single structure shows the best thermal stability compared with the other Ni-silicide using TiN and Co/TiN capping layers. To enhance the thermal stability up to 650 ˚C and find out the optimal thickness of Ni silicide, different thickness of Ni-V was also investigated in this work.

Developing homogeneous ion exchange membranes derived from sulfonated polyethersulfone/N-phthaloyl-chitosan for improved hydrophilic and controllable porosity

Zhixue Li,Zhun Ma,Yuting Xu,Xiaomeng Wang,Yongchao Sun,Rong Wang,Jian Wang,Xueli Gao,Jun Gao 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.8

Ion exchange membranes (IEMs) composed of sulfonated poly (ether sulfone) (SPES) and N-phthaloyl chitosan (NPHCs) were synthesized. NPHCs was employed in membrane fabrication to improve the porosity and hydrophilicity of membranes. The effect of blend ratio of sulfonation (DS) and NPHCs content on physico-chemical characteristics of home-made membranes was investigated. The morphology of prepared membranes was investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD) and scanning electron microscopy (SEM). SEM images revealed the formation of a more porous membrane structure and smoother surface. The electrochemical and physical properties of CEMs were characterized comprising water content, contact angle, ion exchange capacity (IEC) and thermal stability. Membrane water content, surface hydrophilicity and IEC were enhanced with increase of DS and NPHCs blend ratios in casting solution. Furthermore, the diffusion coefficient was also improved slightly with increase of DS and NPHCs blend ratios in prepared membranes. Membrane potential, permselectivity, transport number and areal membrane resistance all showed decreasing trends by the increase in NPHCs blend ratio in casting solution. These results indicated that the prepared membrane has good prospective and great potential for desalination in electrodialysis applications.