• Horticultural Science & Technology
• /
• v.17 no.3
• /
• pp.337-340
• /
• 1999

In order to evaluate stored apple pollen viability, in vitro germination test was performed on a microscope slide coated with the culture medium containing fluorescein diacetate (FDA). However, the inclusion of FDA to the culture medium declined pollen germination. Alternatively, the fluorochromatic reaction procedure was tested. The procedure involved dusting pollen grains onto drops of 10% sucrose solution containing 0.002% FDA and allowing them to accumulate fluorescein. Within 30 min after the fluorochromatic reaction, viable pollen grains clearly fluoresced under ultraviolet light. Both the in vitro germination test and the fluorochromatic reaction procedure revealed that stored apple pollen viability was not considerably decreased over storage up to at least 39 months. Of the cultivars examined by both methods, 'Fuji' and 'Senshu' pollen viability was highest, 'Tsugaru' was intermediate, and 'Jonagold' was lowest. The fluorescing percentages appeared approximately comparable to the germination percentages except for the 'Senshu' pollens stored for 3 months, although the fluorescing percentages was slightly higher than the germination percentages. Strong and highly significant correlations were found between the two methods. It can thus be concluded that the fluorochromatic reaction procedure provides a convenient and reliable evaluation of stored apple pollen viability.

• Horticultural Science & Technology
• /
• v.17 no.4
• /
• pp.476-480
• /
• 1999

This study was carried out to determine the optimum storage temperatures of six fruit nurseries ('Fuji' apple, 'Niitaka' pear, 'Sheridan' grape, 'Yumyoung' peach, 'Fuyu' persimmon, and 'Hayward' kiwifruit) from 1995 to 1997. Nursery plants were planted in field after storage at -5, 0, and $5^{\circ}C$ for one year. Nurseries stored at $0^{\circ}C$ showed highest survival rate and growth after planting. The survival rate of 'Sheridan' grape and 'Hayward' kiwifruit nursery plants stored at $-5^{\circ}C$ was 0%. Cold resistance of the two fruit nursery plants appeared weaker than others. Also, 'Niitaka' pear nursery plants stored at $5^{\circ}C$ showed significantly high survival rate and growth after planting. The higher storage temperature, the lower mineral and carbohydrate contents of nursery plants. Therefore, $0{\sim}5^{\circ}C$ in 'Niitaka' pear and near $0^{\circ}C$ in other five fruit nursery stocks were found to be the optimum storage temperatures.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.22 no.4
• /
• pp.361-368
• /
• 2002

The aim of this study was to investigate the effect of preprocessing the transmitted energy spectrum data on development of a robust model to predict the sugar content in intact apples. The spectrum data were measured from 120 Fuji apple samples conveying at the speed of 2 apples per second. Computer algorithms of preprocessing methods such as MSC, SNV, first derivative, OSC and their combinations were developed and applied to the raw spectrum data set. The results indicated that correlation coefficients between the transmitted energy values at each wavelength and sugar contents of apples were significantly improved by the preprocessing of MSC and SNV in particular as compared with those of no-preprocessing. SEPs of the prediction models showed great difference depending on the preprocessing method of the raw spectrum data, the largest of 1.265%brix and the smallest of 0.507% brix. Such a result means that an appropriate preprocessing method corresponding to the characteristics of the spectrum data set should be found or developed for minimizing the prediction errors. It was observed that MSC and SNV are closely related to prediction accuracy, OSC is to number of PLS factors and the first derivative resulted in decrease of the prediction accuracy. A robust calibration model could be d3eveloped by the combined preprocessing of MSC and OSC, which showed that SEP=0.507%brix, bias=0.0327 and R2=0.8823.

• Research in Plant Disease
• /
• v.16 no.3
• /
• pp.247-253
• /
• 2010

Apple scar skin viroid (ASSVd) is one of the smallest viral pathogens infecting fruits, especially apple, and causes a significant damage to fruit trees. ASSVd usually induced the skin-dapple ring symptoms, but in 'Fuji' varieties, corked spot were occurred on the fruit skin in 2009. This new symptom will be of great helpful to diagnosis ASSVd in sight. ASSVd was surveyed in apple and pear from 2009 to 2010 in Korea, and ASSVd was identified in 20 out of 1,193 trees. The infection rate was 1.7%. To screen the infectivity of ASSVd among apple cultivars, real-time RT-PCR was applied followed by designing of ASSVd specific primers based on highly conserved regions of several ASSVd isolates including Korean isolate. NADH dehydrogenase subunit 5 (nad 5) gene, which is mRNA of the mitochondrial gene, was used for internal control. In this study, ASSVd infected apples were classified into 12 groups depending on different symptoms and symptom severity (scaring, rusting or malformation). Taken together, this study suggested that real-time PCR analysis was more sensitive to detect the low copy of ASSVd on early viroid infected apple skins than regular RT-PCR method.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
• /
• 2001.06a
• /
• pp.1131-1131
• /
• 2001

To develop a nondestructive quality evaluation technique of fruits, a K-mean algorism is applied to near infrared (NIR) spectroscopy of apples. The K-mean algorism is one of neural network partition methods and the goal is to partition the set of objects O into K disjoint clusters, where K is assumed to be known a priori. The algorism introduced by Macqueen draws an initial partition of the objects at random. It then computes the cluster centroids, assigns objects to the closest of them and iterates until a local minimum is obtained. The advantage of using neural network is that the spectra at the wavelengths having absorptions against chemical bonds including C-H and O-H types can be selected directly as input data. In conventional multiple regression approaches, the first wavelength is selected manually around the absorbance wavelengths as showing a high correlation coefficient between the NIR $2^{nd}$ derivative spectrum and Brix value with a single regression. After that, the second and following wavelengths are selected statistically as the calibration equation shows a high correlation. Therefore, the second and following wavelengths are selected not in a NIR spectroscopic way but in a statistical way. In this research, the spectra at the six wavelengths including 900, 904, 914, 990, 1000 and 1016nm are selected as input data for K-mean analysis. 904nm is selected because the wavelength shows the highest correlation coefficients and is regarded as the absorbance wavelength. The others are selected because they show relatively high correlation coefficients and are revealed as the absorbance wavelengths against the chemical structures by B. G. Osborne. The experiment was performed with two phases. In first phase, a reflectance was acquired using fiber optics. The reflectance was calculated by comparing near infrared energy reflected from a Teflon sphere as a standard reference, and the $2^{nd}$ derivative spectra were used for K-mean analysis. Samples are intact 67 apples which are called Fuji and cultivated in Aomori prefecture in Japan. In second phase, the Brix values were measured with a commercially available refractometer in order to estimate the result of K-mean approach. The result shows a partition of the spectral data sets of 67 samples into eight clusters, and the apples are classified into samples having high Brix value and low Brix value. Consequently, the K-mean analysis realized the classification of apples on the basis of the Brix values.

• Restorative Dentistry and Endodontics
• /
• v.24 no.1
• /
• pp.136-146
• /
• 1999

The purpose of this study was to estimate the changes of marginal adaptation to the cavity floor of light-cured glass ionomer cement base after application of a composite restoration. Eighty non-carious extracted human molars were used in the present study. Circular cavities were prepared on the center of the exposed dentin surface to 0.5mm, 1.0mm, 1.5mm, 2.0mm in depth and the prepared cavities were pretreated with Dentin conditioner and filled with Fuji II LC(GC Int. Co., Japan). They randomly assigned into 3 groups according to the difference in application of a composite restoration; Group 1(control group): only glass ionomer base, Group 2: The application of a composite restoration surrounded by dentin with class I cavity over glass ionomer base after conventional dentin bonding to the exposed dentin and glass ionomer base, Group 3: The application of composite restoration not-surrounded by dentin over glass ionomer base after conventional dentin bonding to the exposed dentin and glass ionomer base. To examine the interface between cavity floor and light-cured glass ionomer cement base, each groups were sectioned vertically through the center of restorations with diamond saw and the gap size(${\mu}m$) of interface measured by SEM. The results were analyzed by using One Way ANOVA. The results were as follows: 1. Good adaptation between glass ionomer cement base and cavity floor was showed in specimens with 0.5mm, 1.0mm depth base of control group. But in specimens with 1.5mm, 2.0mm depth base of control group, the gap was measured about $15{\mu}m$, $40{\mu}m$ respectively. 2. Gap size in group 2 was significantly higher than that in control group(P<0.05). 3. Gap size in group 3 was significantly higher than that in control group and group 2(P<0.05). 4. It was possible to observe the good adaptation between glass ionomer cement base and dentin which was intermediated with 4-10${\mu}m$ hybrid layer in specimens with 0.5mm, 1.0mm depth base of control group. Cohesive fracture within cement base was observed in all specimens which had the gap between glass ionomer cement base & dentin. 5. It was possible to observe the gap formation between cement base and bonding agent and between composite resin and dentin in all specimens of group 2.

• The Korean Journal of Pesticide Science
• /
• v.12 no.3
• /
• pp.291-294
• /
• 2008

The Streptomyces padanus isolate TH04, isolated from mummified peaches, showed strong antifungal activity to Monilinia fructicola. The inhibition activity of the isolate TH04 to mycelial growth and spore germination at 1% concentration of sub-antifungal powder made from culture suspension (CS) was ranged from 79.8% to 81.0% and from 73.9% to 75.8% to M. fructicola four strains, respectively. In the test of antifungal activity in mixed culture of the isolate and M. fructicola, inhibition rate was 7.5%, 86.8% and 94.0% in 0.01, 0.1, and 1% concentration of CS containing bacterial cell of the isolate, respectively. On apples (cultivar; Fuji), the control values of the isolate TH04 crude filtrates (0.1 and 1%) were 85.9% and 100%, respectively. The results suggest that the isolate TH04 indicate development possibility as biocontrol agent of brown rot caused by M. fructicola with the study on delivery method and fermentation condition to produce an antifungal compound.

• Restorative Dentistry and Endodontics
• /
• v.33 no.6
• /
• pp.570-579
• /
• 2008

The purpose of this study was to investigate the distribution of tensile stress of canal obturated maxillary second premolar with access cavity and notch-shaped class V cavity restored with composite resin using a 3D finite element analysis. The tested groups were classified as 8 situations by only access cavity or access cavity with notch-shaped class V cavity (S or N), loading condition (L1 or L2), and with or without glass ionomer cement base (R1 or R2). A static load of 500 N was applied at buccal and palatal cusps. Notch-shaped cavity and access cavity were filled microhybrid composite resin (Z100) with or without GIC base (Fuji II LC). The tensile stresses presented in the buccal cervical area, palatal cervical area and occlusal surface were analyzed using ANSYS. Tensile stress distributions were similar regardless of base. When the load was applied on the buccal cusp, excessive high tensile stress was concentrated around the loading point and along the central groove of occlusal surface. The tensile stress values of the tooth with class Ⅴ cavity were slightly higher than that of the tooth without class V cavity. When the load was applied the palatal cusp, excessive high tensile stress was concentrated around the loading point and along the central groove of occlusal surface. The tensile stress values of the tooth without class V cavity were slightly higher than that of the tooth with class V cavity.

• The korean journal of orthodontics
• /
• v.25 no.5 s.52
• /
• pp.605-611
• /
• 1995

The purpose of this study was to evaluate effects of time on shear bond strengths of a light-cured glass ionomer cement and chemically cured resin cement to enamel, and to observe the failure patterns of bracket bondings. Shear bond strength of a light-cured glass ionomer cement were compared with that of a resin cement. Metal brackets were bonded on the extracted human bicuspids. Specimens were subjected to a shear load(in an Instron machine) after storage at room temperature for 5 and 15 minutes; after storage in distilled water at $37^{\circ}C$ for 1 or 35 days. The deboned specimens were measured In respect of adhesive remnant index. The data were evaluated and tested by ANOVA, Duncan's multiple range test, and t-test, and those results were as follows. 1. The shear bond strength of light-cured glass ionomer cement is higher than that of resin cement at 5 and 15 minutes. 2. The shear bond strengths of both light-cured glass ionomer cement and resin cement increase with time. There was no significant difference in those of both 1 day group and 35 day group 3. Light-cured glass ionomer cement is suitable as orthodontic bracket adhesives

• The Journal of Korean Academy of Prosthodontics
• /
• v.38 no.2
• /
• pp.169-177
• /
• 2000

The purpose of this study was to compare the retention of complete cast crown over amalgam ores, composite resin cores, and cast gold cores when cemented with three different luting agents. Eighteen core specimens each of amalgam(Bestaloy, Dong Myung, Seoul, Korea), composite resin (Z100, 3M Dental product, st. Paul, Minn) and type IV gold alloy (Ba-4, Heesung Engelhard Corp., Korea) were made in a customized milling stainless steel die. A wax pattern with a loop attached to occlusal surface was made for each core and a type II gold alloy casting was fabricated. The castings which had clinically acceptable marginal fit were used as test samples. The following luting cements were used to cement cast crowns on each core material : (1) zinc phosphate cement (Confi-dental Products Co., USA) (2) glass-ionomer cement (Fuji Plus, GC Industrial Corp., Tokyo, Japan) (3) resin cement (Panavia 21, Kuraray Co., USA). All cements were mixed according to manufacturers' instructions. A static load of 5kg was then applied for 10 minutes on the crowns. All specimens were stored in saline solution for 24 hours at $37^{\circ}C$ and thermocycled for 500 cycles. After storage and cycling, the tensile bond strengths were measured by using a universal testing machine (Instron Corp., Canton, Mass.) at a crosshead speed of 0.5mm/min. The results were as follows 1. The retentive strength of resin cement was the highest of alt three types of cement for resin core (p<0.05). 2. There was no statistical difference among the retentive strengths of three cements for amalgam core (p>0.05). 3. The retentive strength of resin cement was higher than that of zinc phosphate for cast core, but there was no difference between the retentive strength of glass ionomer cement and those of rein and zinc phosphate cement. 4. The retentive strength of the zinc phosphate cement for amalgam core was the highest of all type of cores.