Analysis of Market Reaction on Company’s Information Disclosure and Investor’s Trading Behavior. Based on KOSDAQ Market Within Three IPO Years

Anzhela Tsoy,Ki-Dong Lee 한국지능정보시스템학회 2013 한국지능정보시스템학회 학술대회논문집 Vol.2013 No.11

In this paper we investigate market reaction on various corporate announcements and main motives causing investors to trade around them within three years of IPO dates. Our research based on IPO companies listed on KOSDAQ market from January 2000 to September 2012 and concentrates on three disclosures – bonus issue, seasoned equity offer and new investment in facilities announcements. We find that market positively react on bonus issues and seasoned equity offers, but negatively on new investment announcements. Trading volume increases before the positive events and all investor groups actively buy shares in these periods. For the negative events only institution traders show active selling. Overall, institutions act as momentum traders and individuals with foreigners as contrarian traders.

Intellectual Reaction Differences among Market Participants to a Company’s Information Disclosureand Trading Behaviors on IPO KOSDAQ

Anzhela Tsoy,Ki-Dong Lee(이기동) 한국지능정보시스템학회 2014 지능정보연구 Vol.20 No.1

본 논문은 주식 시장 참가자들의 여러 기업 공시에 대한 다양한 지능적인 반응의 차이점과 거래 행동에 영향을 미치는 주요 정보를 분석하였다. 본 연구는 2000년01월부터 2012년 09월까지 코스닥 시장에 신규 상장을 된 기업과 3가지 공시를(무상증자, 유상증자, 신규 시설 투자) 한 기업들을 대상으로 하였다. 시장 참가자들이 무상증자와 유상증자 공시일 경우에 긍정적으로 반응하고 신규 시설 투자일 경우에 부정적으로 반응하다는 연구 결과가 나왔다. 시장 거래량은 긍정적인 사건 전에 급격히 증가하며 모든 그룹의 참가자들의 매수가 활발히 이루어진다. 부정적인 사건일 경우에 기관 참가자들만 활발한 매수 행동을 보여준다. 종합적으로, 기관들은 모멘텀 전략을 보여주며, 개인과 외국인들은 반대투자전략을 보여준다. 본 논문의 합축성도 논의했다. In this paper, we investigate intellectual reaction differences among market participants to various corporate information announcements and the main information prompting investors to trade. Our research is based on IPO companies listed on the KOSDAQ exchange from January 2000 to September 2012 and concentrates on three information disclosures – bonus issue, seasoned equity offer, and new investment in facilities announcements. We find that intellectual market participants react positively to bonus issues and seasoned equity offers, but negatively to new investment announcements. Market trading volume increases before the positive events and all cgroups actively buy shares during these periods. For the negative events, only institution participants show active selling. Overall, institutions act as momentum traders, and individuals and foreigners as contrarian traders. We also discuss the implications of this study.

On the possibility of obtaining soft dosage forms based on polyanionic polysaccharides with prolonged yield of drugs

Anzhela Shurshina,Mariya Afanasyeva,Valentina Chernova,Mariya Lazdina,Elena Kulish 한국고분자학회 2024 Macromolecular Research Vol.32 No.3

The work is devoted to the creation of liquid and soft gel dosage forms of prolonged action. The main task to be solved in the work was to give certain rheological characteristics (namely, pseudoplastic behaviour and pronounced yield strength) to dosage forms based on solutions of pectin, sodium salt of carboxymethylcellulose and sodium salt of chitosan succinate, namely. The study has found that the effect of prolonging the release of the medicinal substance cefazolin from liquid and soft dosage forms based on polysaccharides is directly related to the rheological characteristics of the system and can manifest itself in two cases. First, it is possible for liquid dosage forms in the area of polymer concentrations in solution lower than the concentration at which the cell of meshes C < Ce is formed. In this case, with an increase in the polymer concentration, there is a decrease in the rate of the drug substance release, due to an increase in the adduct of the polymer-drug reaction Secondly, it is possible for soft gel forms in the region of concentrations greater than the concentration at which the cell of meshes C < Ce is formed, when using additives capable of ionotropic gel formation. Calcium and zinc salts were used as such additives in the work. It is in the case when the modifying additive is capable of forming a “bridging” bond between macromolecules and the gel formation is not accompanied by a decrease in the amount of the complex adduct of the reaction, there is a prolongation effect. If the gel is only formed by increasing the polymer content in the solution without the use of an additive, the compression of macromolecular tangles and the strengthening of intramolecular interaction between the polymer units in a concentrated solution results in a significant decrease in the amount of the polymer-drug reaction adduct and accelerated the drug release from the soft dosage form.

The possibility of using dibasic acids as regulators of chitosan transport properties

S. Anzhela Shurshina,N. Timur Mukhamedyarov,G. Lyudmila Kuzina,Yu. Mariya Lazdina,Elena Kulish 한국고분자학회 2023 Macromolecular Research Vol.31 No.9

Recently, a significant number of works have appeared devoted to the creation of materials with controlled delivery of drugs. The most promising polymers for these purposes are polysaccharides, in particular chitosan. Unfortunately, film materials obtained from a solution based on chitosan in salt form are soluble in water. In this regard, the purpose of this work was to consider the possibility of modifying the chitosan film materials. Sodium sulfate, phosphoric, succinic, and oxalic acids were chosen as polymer material modifiers. It was shown that the introduction of sodium sulfate, phosphoric, and oxalic acids leads to the loss of solubility of the film materials, changes of the shape of the sorption curve and decrease in the values of the diffusion coefficients of water vapor occurs. The introduction of a weak dibasic succinic acid as a modifier does not lead to a change in the process of sorption regime. The similar regularities are founded in the study of the process of drug release from the polymer material. Thus, fundamentally possible ways of regulating the transport properties of the chitosan film material with respect to the yield of drugs have been found, which consist in the modification of chitosan with anions of strong polybasic acids.

Similarities and differences between 6S RNAs from Bradyrhizobium japonicum and Sinorhizobium meliloti

Olga Y. Burenina,Daria A. Elkina,Anzhela Y. Migur,Tatiana S. Oretskaya,Elena Evguenieva-Hackenberg,Roland K. Hartmann,Elena A. Kubareva 한국미생물학회 2020 The journal of microbiology Vol.58 No.11

6S RNA, a conserved and abundant small non-coding RNA found in most bacteria, regulates gene expression by inhibiting RNA polymerase (RNAP) holoenzyme. 6S RNAs from α-proteobacteria have been studied poorly so far. Here, we present a first in-depth analysis of 6S RNAs from two α-proteobacteria species, Bradyrhizobium japonicum and Sinorhizobium meliloti. Although both belong to the order Rhizobiales and are typical nitrogen-fixing symbionts of legumes, their 6S RNA expression profiles were found to differ: B. japonicum 6S RNA accumulated in the stationary phase, thus being reminiscent of Escherichia coli 6S RNA, whereas S. meliloti 6S RNA level peaked at the transition to the stationary phase, similarly to Rhodobacter sphaeroides 6S RNA. We demonstrated in vitro that both RNAs have hallmarks of 6S RNAs: they bind to the σ70-type RNAP holoenzyme and serve as templates for de novo transcription of so-called product RNAs (pRNAs) ranging in length from ~13 to 24 nucleotides, with further evidence of the synthesis of even longer pRNAs. Likewise, stably bound pRNAs were found to rearrange the 6S RNA structure to induce its dissociation from RNAP. Compared with B. japonicum 6S RNA, considerable conformational heterogeneity was observed for S. meliloti 6S RNA and its complexes with pRNAs, even though the two 6S RNAs share ~75% sequence identity. Overall, our findings suggest that the two rhizobial 6S RNAs have diverged with respect to their regulatory impact on gene expression throughout the bacterial life cycle.