Preparation of Thermo-Responsive and Injectable Hydrogels Based on Hyaluronic Acid and Poly(N-isopropylacrylamide) and Their Drug Release Behaviors

Ha Dong In,Lee Sang Bong,Chong Moo Sang,Lee Young Moo,Kim So Yeon,Park Young Hoon The Polymer Society of Korea 2006 Macromolecular Research Vol.14 No.1

Copolymers composed of hyaluronic acid (HA) and poly(N-isopropylacrylamide) (PNIPAAm) were prepared to create temperature-sensitive injectable gels for use in controlled drug delivery applications. Semi-telechelic PNIPAAm, with amino groups at the end of each main chain, was synthesized by radical polymerization using 2-aminoethanethiol hydrochloride (AESH) as the chain transfer agent, and was then grafted onto the carboxyl groups of HA using carbodiimide chemistry. The result of the thermo-optical analysis revealed that the phase transition of the PNIPAAm-grafted HA solution occurred at around 30$\∼$33$^{circ}C$. As the graft yield of PNIPAAm onto the HA backbone increased, the HA-g-PNIPAAm copolymer solution exhibited sharper phase transition. The short chain PNIPAAm-grafted HA ($M_{w}$=6,100) showed a narrower temperature range for optical turbidity changes than the long chain PNIPAAm-grafted HA ($M_{w}$=13,100). PNIPAAm-grafted HA exhibited an increase in viscosity above 35$^{circ}C$, thus allowing the gels to maintain their shape for 24 h after in vivo administration. From the in vitro riboflavin release study, the HA-g-PNIPAAm gel showed a more sustained release behavior when the grafting yield of PNIPAAm onto the HA backbone was increased. In addition, BSA released from the PNIPAAm-g-HA gels showed a maximum concentration in the blood 12 h after being injected into the dorsal surface of a rabbit, followed by a sustained release profile after 60 h.

Ultrasound-Triggered Drug Release of Hydroxyapatite Coated Liposomes

조성근,위태인,하정,조선행,한건,한희동,신병철,Cho, Sung Keun,Wee, Tae In,Ha, Jeung,Cho, Sun Hang,Han, Kun,Han, Hee Dong,Shin, Byung Cheol Korean Chemical Society 2013 대한화학회지 Vol.57 No.4

리포솜은 표적 약물을 봉입하여 병소에 안전하게 전달할 수 있는 약물전달체로서 연구되고 있다. 그러나 일반적인 리포솜은 표적부위에서 약물방출이 제한적인 문제점이 있다. 따라서 본 연구에서는 리포솜의 안정성을 향상시키고 표적부위에서 외부 초음파로부터 약물의 방출을 극대화시키기 위하여 하이드록시아파타이트(hydroxyapatite, HA)가 코팅된 리포솜을 개발하였다. 대조군 리포솜은 인지질과 콜레스테롤을 이용하여 제조하였고, 대조군 리포솜의 표면에 칼슘 아세테이트, 포스포릭에시드, 그리고 25% 암모니아용액을 이용하여 HA를 코팅하였다. 모델 약물로는 독소루비신을 사용하였다. HA코팅 리포솜의 크기는 120 nm 이었고, 약물봉입효율은 95% 이상이었다. 30% 혈장용액 내에서 HA코팅 리포솜의 입자크기는 일정한 상태를 유지하였으며, 대조군 리포솜은 크기가 1.4배 증가하였다. 외부 초음파 자극에 의한 리포솜으로부터 약물 방출을 유도한 후, 방출된 약물의 세포 이입율은 HA 코팅된 리포솜이 3배 이상 대조군 리포솜에 비하여 증가하였다. 본 연구에서는 외부 초음파 자극에 의하여 리포솜으로부터 약물의 방출을 극대화시키기 위한 초음파 민감형 리포솜을 개발하였고, 본 제형은 표적부위에서 약물의 방출을 효과적으로 제어하기 위한 분야에 활용이 가능할 것이다. Liposomes, which can deliver payload at target site, have been studied as drug carrier. However, conventional liposomes have limitation for drug release at target site. Therefore, we developed hydroxyapatite (HA) coated ultrasound sensitive liposomes to increase drug release at target site and to enhance stability in blood stream. Control liposome was prepared using hydrogenated soy phosphatidylcholine (HSPC) and cholesterol, and then we assessed HA coating on the surface of control liposomes using calcium acetate, phosphoric acid, and 25% ammonium solution. Doxorubicin was used as a model drug. Size of HA coated liposomes was 120 nm and encapsulation efficiency of doxorubicin in liposomes was up to 95%. Size of HA coated liposomes are not changed in 30% serum solution, however, the control liposomes was 1.4 fold increased. After ultrasound triggered drug release from liposomes, intracellular efficiency of drug released from HA coated liposomes was 3 fold increased compared to control liposomes. In this study, we developed ultrasound sensitive liposomes to enhance drug release, which will be applied in controlled drug release at disease site.

Effect of Non-animal-Derived Nitrogen Sources on the Production of Hyaluronic Acid by Streptococcus sp. KL0188

Lee, Gil-Yong,Ha, Suk-Jin,Jung, Jong-Hyun,Seo, Dong-Ho,Park, Jong-Yul,Kim, Su-Rin,Park, Nam-Woo,Kweon, Dong-Keon,Park, Sang-Hoo,Park, Cheon-Seok The Korean Society for Applied Biological Chemistr 2009 Applied Biological Chemistry (Appl Biol Chem) Vol.52 No.3

Hyaluronic acid (HA) is a linear high-molecular-weight polysaccharide with useful biomedical applications. Streptococcus zooepidemicus, a typical HA-producing bacterium, requires an animal-derived nitrogen source such as tryptone, peptone or sheep blood as a nutrient. Sixteen non-animal-derived (NAD) nitrogen sources were tested as a replacement for the expensive animal-derived nitrogen sources, which may have safety issues. Among the sixteen tested NAD nitrogen sources, a yeast-derived nitrogen source (YE 0251) showed the highest HA productivity, which was equivalent to the control HA production medium containing tryptone in a 5-L jar and in 3,000-L industrial fermentations. In the 3,000-L fermentation, YE 0251 increased cell mass (dry cell weight) and HA production by 11% and 8%, respectively, compared with the control HA production medium. The fmal specific volumetric productivity (0.41 g/L h) was improved by about 70% after reducing the fermentation time from 20 h to 12 h, compared to the conventional production medium.

연구논문 : 만성 바이러스간질환에서 간섬유화의 다양한 비침습 혈청표지자검사의 비교

김선민 ( Sun Min Kim ),손주현 ( Joo Hyun Sohn ),김태엽 ( Tae Yeob Kim ),노영욱 ( Young Wook Roh ),은창수 ( Chang Soo Eun ),전용철 ( Yong Cheol Jeon ),한동수 ( Dong Soo Han ),오영하 ( Young Ha Oh ) 대한간학회 2009 Clinical and Molecular Hepatology(대한간학회지) Vol.15 No.4

목적: 만성 바이러스간질환에서 병의 경과와 예후를 평가하고 치료반응을 예측함에 있어 간섬유화의 진단은 중요하다. 최근 간섬유화 평가에 표준방법이지만 침습적 간생검을 대신하여 여러 가지 비침습적 진단법이 이용되고 있고, 또한 새로운 검사법들이 개발되고 있다. 저자들은 만성 B형 및 C형간염 환자를 대상으로 임상에서 광범위하게 흔히 시행하는 혈액검사와 임상 소견을 이용한 아래와 같은 진단법들만으로 간섬유화를 얼마나 정확하게 평가할 수 있는지 알아보고, 단일 검사로 간섬유화를 평가하는 데 유용하다고 알려져 있는 hyaluronic acid(HA)와 IV형 콜라겐 농도와 비교하여 그 임상적 유용성을 평가하였다. 대상과 방법: 2002년 3월부터 2007년 2월까지 만성 바이러스간 질환으로 간생검을 시행받은 225명의 환자(HBV 180명, HCV 43명, HBV+HCV 2명)를 대상으로 분석하였다. 간생검을 시행하는 날에 말초혈액검사, 혈액응고검사, 혈청생화학검사를 시행하고, 혈중 HA, IV형 콜라겐 농도를 측정하였다. 간섬유화의 정도는 F0(섬유화가 없음), F1(문맥역 섬유화), F2(문맥주변부 섬유화), F3(섬유성 격막) 및 F4(간경변증)의 4단계로 구분하였다. 대상 환자를 F0-1, F2-4 혹은 F0-2, F3-4의 두 집단으로 분류하여 두 집단을 구분하고자 할 때 AAR(AST/ALT ratio), API(age-platelet index), APRI(AST to platelet index), CDS(cirrhosis discriminant score), platelet count, HA, IV형 콜라겐의 예측능을 area under the receiver operating characteristic curve (AUROC)값을 이용하여 비교하였다. 결과: 대상환자의 섬유화의 단계는 F0 집단은 17명, F1 집단은 40명, F2 집단은 61명, F3 집단은 74명, F4 집단은 33명이었다. 의미 있는 간섬유화를 F2 이상으로 판단할 때, 의미 있는 섬유화의 예측에 대한 AUROC 값은 APRI=0.822, CDS=0.776, platelet count=0.773, API=0.756, HA=0.749, IV형 콜라겐=0.718, AAR=0.642 순이었고, F3 이상의 광범위한 섬유화 예측에 대한 AUROC값은 CDS=0.835, platelet count=0.795, API=0.794, HA=0.766, AAR=0.711, IV형 콜라겐=0.697, APRI=0.691 순으로 관찰되었다. 결론: 만성 바이러스간질환에서 간섬유화를 평가하는 데 임상 소견 및 혈액검사를 이용한 방법들이 비침습적 진단법 중 단독 검사로도 유용한 것으로 알려져 있는 혈중 HA와 IV형 콜라겐 농도와 비교하여 우월하거나 대등하였다. 특히 APRI는 다른 인자들에 비해 F2 이상의 의미 있는 섬유화를 예측하는 데 가장 유용하였고, CDS는 F3 이상의 광범위한 섬유화를 예측하는 데 가장 유용하였다. Background/Aims: The aim of this study was to determine the clinical performances of noninvasive serum markers for the prediction of liver fibrosis in chronic viral liver diseases. Methods: We analyzed a total of 225 patients with chronic viral liver diseases (180 with hepatitis B virus, 43 with hepatitis C virus, and 2 with hepatitis B+C virus) who underwent a liver biopsy procedure at the Hanyang University Guri Hospital between March 2002 and February 2007. Serum was also obtained at the time of liver biopsy. Liver fibrosis was staged according to the scoring system proposed by the Korean Study Group for the Pathology of Digestive Diseases. Various noninvasive serum markers were evaluated, including the aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio (AAR), age-platelet (AP) index, AST/platelet ratio index (APRI), cirrhosis discriminant score (CDS), platelet count, hyaluronic acid (HA), and type IV collagen. Results: There were 17, 40, 61, 74, and 33 patients at stages F0, F1, F2, F3, and F4, respectively. The overall diagnostic accuracies of each marker, as determined by the area under receiver operating characteristics curves, were APRI=0.822, CDS=0.776, platelet count=0.773, AP index=0.756, HA=0.749, type IV collagen=0.718, and AAR=0.642 for predicting significant fibrosis (≥F2); and CDS=0.835, platelet count=0.795, AP index=0.794, HA=0.766, AAR=0.711, type IV collagen=0.697, and APRI=0.691 for predicting extensive fibrosis (≥F3). Conclusions: Conclusions: All noninvasive serum markers evaluated in this study were useful for predicting significant or extensive liver fibrosis in chronic viral liver diseases. In particular, APRI was most useful for the prediction of significant fibrosis, and CDS was most useful for the prediction of extensive fibrosis. (Korean J Hepatol 2009;15:454-463)

A Systematic Review and Meta-Analysis of Arthroscopic Meniscus Repair in Young Patients: Comparison of All-Inside and Inside-Out Suture Techniques

Dong­Geun Kang,Young­Jin Park,Jae­Ha Yu,Jong­Byung Oh,Dong-Yeong Lee 대한슬관절학회 2019 대한슬관절학회지 Vol.31 No.1

Purpose: The purposes of the present study were to review published studies that investigated arthroscopic meniscus repair to treat meniscus injury in young patients and to compare all­inside and inside­out suture techniques.Methods: Various electronic databases were queried for published articles, and this search was updated in August 2017 for evaluating the outcomes of arthroscopic meniscus surgery in young patients. Data search, extraction, analysis, and quality assessment were performed according to the Cochrane Collaboration guidelines, and the clinical outcomes were evaluated using various outcome values in young patients according to suture techniques.Results: Three randomized controlled trials and three prospective comparative studies were included in this systematic review and meta­analysis. There were no significant differences in clinical outcomes such as meniscus healing rate (risk ratio [RR], 1.11; 95% confidence interval [CI], 0.90 to 1.37; I2=39%) and perioperative complications (RR, 0.62; 95% CI, 0.23 to 1.72; I2=43%) between all­inside and inside­out techniques for meniscus repair.Conclusions: The present study shows favorable results for clinical outcomes such as meniscus healing rate and perioperative complications in young patients. Furthermore, based on our results, both all­inside and inside­out meniscal suture techniques are equally effective in these patients.

Trophic importance of meiofauna to polychaetes in a seagrass (Zostera marina) bed as traced by stable isotopes

Ha, Sun-Yong,Min, Won-Ki,Kim, Dong-Sung,Shin, Kyung-Hoon Cambridge University Press [etc.] 2014 Journal of the Marine Biological Association of th Vol.94 No.1

<P> Stable carbon and nitrogen isotope ratios of benthic invertebrates and their potential food sources, such as suspended particulate organic matter (POM), benthic microalgae, attached algae and seagrass, were identified in Dong-dae Bay during the winter. The carbon stable isotope ratios demonstrate that filter feeders, such as oysters (?19.5 ± 1.0‰), use benthic microalgae (?21.2 ± 0.2‰) as a major food, and polychaetes such as Glycera spp. (?14.0 ± 0.6 ‰) preferentially use meiofauna, such as nematodes (?14.0 ± 0.4‰) and copepods (?13.3 ± 1.0‰). These meiofauna may feed on mixed resources (including bacteria) with the isotope ratios between benthic microalgae (?21.2 ± 0.2‰) and seagrass (?9.3 ± 01.0‰). These findings are consistent with the trophic enrichment in the nitrogen isotope ratios (by 3?4‰) between consumers and food sources. Moreover, the results of the MixSIR model based on the observed isotope ratios suggest a large seagrass contribution to the food sources of benthic organisms such as meiofauna (~53.7?62.6%) and macrobenthos (~41.1?68%) through the food web. This model additionally suggests a relatively large contribution of benthic microalgae to the food sources of filter feeders (i.e. 26.4% for oysters). </P>

원자기여법에 근거한 유기 할로겐 화합물의 순연소열 예측

Ha,Dong-Myeong,Lee,Sung-Jin 한국화재소방학회 2003 한국화재소방학회논문지 Vol.17 No.4

연소열은 인화성 물질의 화재<TEX>$.$</TEX>폭발 위험성을 결정하는 주요한 물성치이다. 할로겐화 유기화합물의 순연소열을 예측하기 위해서, 원자기여법에 기반을 둔 경험식들이 개발되어 왔다. 본 연구에 개발된 경험식을 Cardozo와 Hanley의 경험식들과 비교해 보았다. A.A.D.를 보면 알 수 있듯이 본 연구에서 제안된 경험식으로 계산된 값이 실험값에 가장 근접해 있음을 확인하였다. 따라서, 본 연구에서 제안된 경험식은 여타 할로겐화 유기화합물의 연소열을 예측하는데 도움을 줄 것으로 사료된다. The heat of combustion is one of the major physical properties used to determine the fire and explosion hazards of the flammable substances. Empirical equations have been developed to pre-dict the net heats of combustion of organic halogenated compounds based on the atomic contribution method. The method developed in this study was compared with Cardozo's method and Hanley's method. As can be seen from the average absolute deviation(A.A.D.), the proposed equation was found to be best. The proposed equation may serve as an estimation scheme for the heats of combustion of the other organic halogenated compounds.

몬순기후와 복잡지형의 특성을 갖는 광릉 산림유역의 물과 탄소순환에 대한 교차규모 연구로부터의 교훈

이동호 ( Dong Ho Lee ),김준 ( Joon Kim ),김수진 ( Su Jin Kim ),문상기 ( Sang Ki Moon ),이재석 ( Jae Seok Lee ),임종환 ( Jong Hwan Lim ),손요환 ( Yo Whan Son ),강신규 ( Sin Kyu Kang ),김상현 ( Sang Hyun Kim ),김경하 ( Kyong Ha Kim 한국농림기상학회 2007 한국농림기상학회지 Vol.9 No.2

광릉 슈퍼사이트에서 대기와 식생간의 에너지와 물질교환 규명은 지형과 식생의 복잡성으로 인해 많은 기술적인 어려움에 직면하고 있다. 따라서 KoFlux 연구에서는 상호보완적인 다중 분야의 연구를 통해 이러한 어려움을 극복하기 위한 시도를 해 오고 있다. 본 논문에서는 현재 진행중인 KoFlux 연구의 예비결과 중 특히 광릉사이트에서의 물/탄소수지, 물과 탄소순환의 상호관련성 그리고 몬순기후하의 생태계에서 탄소순환에 미치는 수문학적 요인의 중요성에 대해 중점적으로 논의하고자 한다. 광릉낙엽활엽수림의 순생태생산량 (NEP)은 광범위한 생태학적 연구결과에 따르면 약 ~2.6 t C/ha/y로 예상된다. 이를 미기상 플럭스 관측 결과와 함께 고려할 때 광릉 산림은 탄소의 중요한 육상흡원으로서 기능함을 예상할 수 있다. 다양한 생태수문 관측에 의해 규명된 유역단위 물수지에 의하면 연단위 전체강수량의 약 30-40%가 증발산 (ET)에 해당함을 나타내고 있다. 광릉산림의 대표적인 수종인 졸참과 서어나무의 잎에서 얻어진 탄소 안정동위 원소 조성에 근거하여 계산된 식물 성장기간의 평균 물 이용효율(WUE)은 약 ~12 μmol CO2/mmol H2O에 해당된다. 얻어진 증발산량과 물이용효율은 유역단위의 생태계 생산량을 산출하는데 이용될 수 있다. 나이테 성장량과 토양호흡량의 연단위 변화는 강수량과 강수의 패턴에 의해 크게 영향을 받음을 보이고, 이는 몬순기후에 영향을 받는 동아시아 지역 생태계에서 탄소 순환과정이 수문학적 조건과 밀접한 상관관계를 가짐을 지시한다. 연구지역의 공간적 특성을 정량화하기 위해 관측지의 구조 및 기능적 단위를 규명하기 위한 연구가 진행되고 있고 이를 통해 서로 다른 시공간 규모에서 진행되고 있는 연구의 결과물을 체계적으로 연결 통합하고 나아가 보다 광역적인 규모에서 대표적인 물/탄소 수지를 산출하기 위한 연구가 시도되고 있다. KoFlux Gwangneung Supersite comprises complex topography and diverse vegetation types (and structures), which necessitate complementary multi-disciplinary measurements to understand energy and matter exchange. Here, we report the results of this ongoing research with special focuses on carbon/water budgets in Gwangneung forest, implications of inter-dependency between water and carbon cycles, and the importance of hydrology in carbon cycling under monsoon climate. Comprehensive biometric and chamber measurements indicated the mean annual net ecosystem productivity (NEP) of this forest to be ~2.6 t C ha-1 y-1. In conjunction with the tower flux measurement, the preliminary carbon budget suggests the Gwangneung forest to be an important sink for atmospheric CO2. The catchment scale water budget indicated that 30~40% of annual precipitation was apportioned to evapotranspiration (ET). The growing season average of the water use efficiency (WUE), determined from leaf carbon isotope ratios of representative tree species, was about 12 μmol CO2/mmol H2O with noticeable seasonal variations. Such information on ET and WUE can be used to constrain the catchment scale carbon uptake. Inter-annual variations in tree ring growth and soil respiration rates correlated with the magnitude and the pattern of precipitation during the growing season, which requires further investigation of the effect of a monsoon climate on the catchment carbon cycle. Additionally, we examine whether structural and functional units exist in this catchment by characterizing the spatial heterogeneity of the study site, which will provide the linkage between different spatial and temporal scale measurements.

콩의 동화기관과 수용기관의 능력평가

Suk Ha Lee,Yeul Gue Seung,Seok Dong Kim 韓國作物學會 1995 Korean journal of crop science Vol.40 No.2

콩의 수량에 대한 광합성 기관(source)과 광합성생물 수용기관(sink)이 미치는 영향을 살펴 보고자, 꼬투리의 크기에 비하여 종실 건물면적이 불량한 수집검정콩인 강릉재래 밀 금릉재래, 꼬투리의 비대가 충실한 백운콩 및 수원 168호를 공시하였다. 두 수준의 재식밀도(ha당 55,000, 110,000 개체)와 개화기 이후 등숙 기간 중 차광막을 설치하여 광합성 능력에 관여하는 환경요인을 변화시킴으로써 나타나는 건물중분배 및 개체수량 반응을 분석한 결과를 요약하면 다음과 같다. 1. 지상부 및 종실건물중의 품종간 광합성능력 변화를 위한 재식밀도 및 차광시 처리간 유의적인 차이가 인정되었고 품종 및 처리간 유의적인 상호작용 효과도 있었다. 2. 지상부 총건물중에 대한 종실건물중 비율은 품종간 차이가 인정되어, 수원 168호가 가장 높았으며, 광합성 능력을 변화시키기 위한 처리 가운데 극히 광이 부족한S2 를 제외한 나머지 세 처리간 차이는 없었다. 3. 등숙기간중에수량을 위한 source와 sink 능력을 광합성 기관 제한정도(source limitation value)에 의하여 품종간 비교하여 보면, 꼬투리에 종실이 충분히 면적되는 수원 168호는 source가, 수집검정콩인 강릉재래나 금릉재래는 sink의 기능이 수량에 있어서 제한요인으로 작용하였다

흰물떼새(Charadrius alexandrinus)의 번식 성공에 대한 환경 요인의 영향

이동윤 ( Dong-yun Lee ),이주현 ( Ju-hyun Lee ),성하철 ( Ha-cheol Sung ) 한국환경생태학회 2021 한국환경생태학회 학술대회지 Vol.2021 No.2

The nest fate of plovers have been affected from around environmental factors such as vegetation, sediment grain size and others, because these factors correlate with the camouflage and consistent temperature of nest. The Kentish plover (Charadrius alexandrinus) is known to select nest site where vegetation cover is low to easily detect predators. However, recent studies show that their nest successes positively correlate with vegetation cover rate, because vegetation can hide incubating parents from predators. Therefore, in this study, we investigated the relationships between vegetation cover and nest fate, and between breeding success and other environmental factors (such as, sand, shell etc.). This study was carried out from early March to late July in 2020 at Saemangeum, specifically (1) Mangyeong estuary, Gunsan, Jellabuk-do; (2) Dongjin estuary, Buan, Jellabuk-do. The study area is reclaimed land with sandy coastal environment, and the size of Mangyeong estuary was about 1,011 ha, Dongjin estuary was about 893 ha. Sedges (family Cyperaceae) were the major vegetation in these locations. We analyzed the effect of environmental factors on the breeding success of Kentish plovers. First, we measured five variables in field: nest diameter (cm), nest height (cm), nest slope (°), distance from nest to the nearest vegetation (m), and the height of the nearest vegetation (cm). Then, we obtained the coordinate of each nest with a GPS and measured distance from nest to water resource (m) using satellite map (Kakao map). We also estimated the cover of environmental factors using 1m² quadrat. The quadrat photos were taken by two ways for each nest: 1) centered on the nest within a 1m²; 2) randomly selected two points in 10m distance from a nest. On the analysis of variables in quadrat photo, we measured the 11 variables. First, we measured the cover of nest area (mm²) and the cover of five environmental factors (dry vegetation, vegetation, sand (grain size < 2 mm), shell and other object; mm²) on the quadrat photos of centered on the nest within a 1m². Second, we also measured the cover of five environmental factors in each photo and calculated the average of two photos on the each factor on the quadrat photos of randomly selected two points in 10m distance from a nest. For statistical analysis, we translated variables using “X = log10 (x + 1); X = translated value; x = origin value” before modelling and analyzed using Generalized Linear Model (GLM). The model criteria was Akaike Criteria Information (AIC). Then, we used Mann-Whitney U test to compared variables between successful and failed nests in the best model. All statistical analysis had a significant effect at p < 0.05. We analyzed 285 quadrat photos (95 photos within a 1m² quadrat centered on each nest; 190 photos on the randomly selected points within 10m area from each nest) from 95 nests: 60 nests in Mangyeong (35 successful nests and 25 failed nests); 35 nests in Dongjin (28 successful nests and 7 failed nests). As the results of GLM, the best model was composed not environmental factors, but three nest factors: nest area, nest diameter and nest slope. In this model, nest area and nest diameter were significant (p < 0.05). However, according to Mann-Whitney test, these factors did not differ between successful and failed nests (p > 0.05). Therefore, when researchers studied the effect of nest factors on the breeding success, nest area and nest diameter should be considered together. On the effect of environmental factors, all factors, which included vegetation and dry vegetation cover, did not affect breeding success. Thus, the other environmental factors should be studied to reveal which one affects the breeding success of Kentish plovers.