• Journal of the Microelectronics and Packaging Society
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• v.10 no.3
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• pp.19-27
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• 2003

Surface finishes of PCB laminates are important in the solder joint reliability of flip chip package because the types and thicknesses of intermetallic compound(IMC), and compositions and hardness of solders are affected by them. In this study, effects of surface finishes of PCB on the low cycle fatigue resistance of Sn-based lead-free solders; Sn-3.5Ag, Sn-3.5Ag-XCu(X=0.75, 1.5), Sn-3.5Ag-XBi(X=2.5, 7.5) and Sn-0.7Cu were investigated for the Cu and Au/Ni surface finish treatments. Displacement controlled room temperature lap shear fatigue tests showed that fatigue resistance of Sn-3.5Ag-XCu(X=0.75, 1.5), Sn-3.5Ag and Sn-0.7Cu alloys were more or less the same each other but much better than that of Bi containing alloys regardless of the surface finish layer used. In general, solder joints on the Au/Ni finish showed better fatigue resistance than those on the Cu finish. Cross-sectional fractography revealed microcracks nucleation inside of the interfacial IMC near the solder mask edge, more frequently on the Cu than the Au/Ni surface finish. Macro cracks followed the solder/IMC interface in the Bi containing alloys, while they propagated in the solder matrix in other alloys. It was ascribed to the Bi segregation at the solder/IMC interface and the solid solution hardening effect of Bi in the $\beta-Sn$ matrix.

• Clean Technology
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• v.20 no.3
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• pp.306-313
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• 2014

Nanoporous $TiO_2$ films are commonly used as working electrodes in dye-sensitized solar cells (DSSCs). So far, there have been attempts to synthesize films with various $TiO_2$ nanostructures to increase the power-conversion efficiency. In this work, vertically aligned rutile $TiO_2$ nanorods were grown on fluorinated tin oxide (FTO) glass by hydrothermal synthesis, followed by deposition of an anatase $TiO_2$ film. This new method of anatase $TiO_2$ growth avoided the use of a seed layer that is usually required in hydrothermal synthesis of $TiO_2$ electrodes. The dense anatase $TiO_2$ layer was designed to behave as the electron-generating layer, while the less dense rutile nanorods acted as electron-transfer pathwaysto the FTO glass. In order to facilitate the electron transfer, the rutile phase nanorods were treated with a $TiCl_4$ solution so that the nanorods were coated with the anatase $TiO_2$ film after heat treatment. Compared to the electrode consisting of only rutile $TiO_2$, the power-conversion efficiency of the rutile-anatase hybrid $TiO_2$ electrode was found to be much higher. The total thickness of the rutile-anatase hybrid $TiO_2$ structures were around $4.5-5.0{\mu}m$, and the highest power efficiency of the cell assembled with the structured $TiO_2$ electrode was around 3.94%.

• Journal of dental hygiene science
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• v.14 no.1
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• pp.22-28
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• 2014

This research aimed to understand the relevance between irritable bowel syndrome (IBS) and sleep quality for dental hygiene students in certain areas. It was conducted on 344 students from four universities in Jeollabuk-do from May to September 2013 using a structured questionnaire. The following are the results. 57.6% of the IBS bowel movement conditions were mixed type, 10.5% constipation type, 7.6% uncategorized, and 6.1% diarrhea type. For sleep quality based on the subjects' general characteristics, third years were 11.45, second years 10.90, and first years 9.53 (p=0.034). The sleep quality was statistically significantly lower as the years increased, and even for IBS (p=0.026), it was low and showed a significant difference. For difference in sleep quality based on IBS presence, habitual sleep efficiency, sleeping pill dosage (p=0.043), and day time functional disorder (p=0.007) showed statistically significant differences and lower sleep quality than the control group. For difference in sleep quality based on IBS bowel movement condition, mixed type was the highest for sleep disturbance at 6.86, constipation type was 1.00 for habitual sleep efficiency, constipation type was 1.42 for subjective sleep quality, uncategorized type was 0.15 for sleeping pill dosage but not statistically significant. In day time functional disorder, constipation type was the highest at 2.61 and showed a significant difference (p=0.012). The correlation between the sub-factors of sleep quality was positive. Based on the above study results, we learned that for IBS, sleep quality becomes lower as the year increases, and functional disorder was observed during day time due to low sleep quality. Education on IBS symptoms is needed, adequate stress management method to alleviate symptoms and prevention programs for correct diet must be developed to enhance sleep quality.

• Journal of the Korean Magnetics Society
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• v.10 no.2
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• pp.67-73
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• 2000

Top spin valve samples with a structure Ta/NiFe/CoFe/Cu/CoFe/FeMn/Ta were deposited on a Si(100) substrate by changing d.c. magnetron sputtering conditions and the exchange-bias and magnetic properties of samples were investigated. The Exchange field, H$\_$ex/ increased with increase of sputtering power of FeMn from 30 to 150 W and CoFe from 30 to 100 W deposited on the Cu, the increase of H$\_$ex/ was found due to the improvement of preferred orientation of (111) FeMn phase from XRD results. In the case of Cu, H$\_$ex/ decreased with the increase of sputtering pressure ranging from 1 to 5 mTorr. The relationship between exchange field and resistance was investigated, spin valve samples with a large exchange field showed the lower resistance, which was strongly dependent on the good crystallinity and grain size increase as well as lower scattering effects. The Cu thickness was changed from 22 to 38 $\AA$ for Si/Ta/NiFe/CoFe/Cu(t), 30 W/CoFe, 100 W/FeMn, 100 W/Ta spin valve structures, MR ratio of 6.5 % and exchange field of about 190 Oe were obtained for the sample with Cu of 22 $\AA$ thickness. The increase of exchange field with decrease of Cu thickness was explained by FM/AFM spin-spin interaction.

• Development and Reproduction
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• v.5 no.2
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• pp.115-122
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• 2001

Production of a mature oocyte is a complex process that requires the close association between oocyte and follicular cells. The present study was conducted to investigate the difference between oocytes with and without close junctional communication with cumulus cells and the involvement of two connexins(CXs) in the interactions. Follicles at different sizes(small: 200～400 ㎛; large:>450 ㎛) were mechanically isolated from PMSG-primed mouse ovaries, and punctured to get cumulus-oocyte complex(COC). Oocytes were released themselves(denuded), with partially attached(partial), or with tightly attached(intact) cumulus cells. Maturation and fertilization capacity of the COCs were measured. Expression of CX 37 and CX 43 was examined by RT-PCR and in situ hybridization. The ratio between intact COC and denude/partial oocytes was 30％(SI) and 70％(SPD) in small follicles, while 55％(LI) and 45％(LPD) in large follicles, respectively. Maturation and fertilization rates of the released oocytes were similar among SI, LPD, LI groups, but those were significantly lower in SPD oocytes. In oocytes, CX 37 was the major CX and CX 43 was not expressed, whereas in the cumulus cells, CX 43 was the major, and CX 37 was the next. Results of the present study suggest that 1) immature oocytes from small follicles with intact cell-to-cell communication with cumulus have the similar quality to that of the oocytes from larger follicles, 2) gap junction between oocyte and cumulus cells may be the heterotypic channel, and 3) we could not explain the difference in the cell-to-cell communication between intact and partial/denuded COCs through the expression of the two CXs.

• Journal of Hospice and Palliative Care
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• v.18 no.2
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• pp.85-96
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• 2015

In Korea, modern art therapy was developed in the 1960s and 1970s in the form of supplementary activities for patients in psychiatry. Along with the foundation of the Korean Association for Clinical Art in 1982 by psychiatric doctors, the therapy involved more various arts forms such as music, art, dance, poetry therapy, and psychodrama. More organizations with specific expertise opened such as the Korean Art Therapy Association, Korean Art Therapy Association, etc. in the 1990s and the Korea Arts Therapy Institute in 2001. As of April 2015, the members of the Korean Art Therapy Association total 15,000, including 6,200 regular members. The arts in integrative arts therapy (IAT) is an individual's creative activity which is related to his inner world, and the forms of IAT include music, drawing, dance and poetry therapy. From the aspect of phenomenology, IAT is psychophysical therapy involving the arts that helps patients recognize and perceive their experiences with an aim of at a recovery of the body and creativity from the phenomenological aspect. It is also a therapeutic activity that targets growth and development of the body and mind. Meta-analysis of the effects of art therapy with a focus on that involving music, drawing, dance movement and IAT in recent years in Korea, significant effects were observed in all factors but physical function. The biggest effect was mentality adaptation followed by activity adaptation and physiology. In the run up to the implementation of the daily flat-rate system for the health insurance reimbursement for palliative care in July 2015, the Ministry of Health and Welfare is reviewing the coverage of music therapy, drawing therapy and flower therapy, which are currently practiced by 56 hospice institutes in Korea. This is a meaningful step because the coverage of hospice and palliative care came after that of art therapy for psychiatric patients was approved in 1977. Still, there is a need clarify the therapeutic mechanism by exploring causality among the treatment media, mediation type and treatment effects. To address the issue of indiscriminately issued licenses, more efforts are needed to ensure expertise and identity of the licensed therapists through education, training and supervision.

• Horticultural Science & Technology
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• v.35 no.2
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• pp.178-187
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• 2017

The aim of this study was to investigate the effect of different light sources on the levels of glucosinolates (GSLs) in rocket salad (Eruca sativa L.). The light sources used in the study were: natural light (Control-1 or 2), red light-emitting diodes(LEDs), blue LEDs, mixed red and blue LEDs (R+B LEDs), white LEDs, fluorescent lamps (FL), and fluorescent lamps plus UV-C (FL+UV-C). Two separate experiments were conducted [Experiment I: Control-1, Red LED, Blue LED, Mix (R+B) LED and Experiment II: Control-2, White LED, FL, FL+UV-C] because of the limited number of growth chambers in our laboratory. The rate of increase in the length of rocket salad leaves was the highest under red LEDs and, FL confirming that red LED and, FL affect the growth of rocket salad. We separated and identified seven types of GSLs from the rocket salad:glucoraphanin, diglucothiobeinin, glucoerucin, glucobrassicin, dimeric 4-mercaptobutyl GSL, 4-methoxyglucobrassicin, and gluconasturtiin. The highest total GSL contents in Eexperiment I was found in plants grown under in red LEDs ($4.30{\mu}mol{\cdot}g^{-1}\;dry$ weight, DW), and the lowest under blue LEDs ($0.17{\mu}mol{\cdot}g^{-1}\;DW$). The highest total GSL contents in Experiment II was found in plants grown under FL ($13.45{\mu}mol{\cdot}g^{-1}\;DW$), and the lowest in FL+UV-C ($0.39{\mu}mol{\cdot}g^{-1}\;DW$). Especially in Experiment II, the content of dimeric 4-mercaptobutyl, which has a strong aroma and spicy flavor in rocket salad, was higher under FL and white LEDs than in Control-2, increasing by approximately 14.9 and 3.2-fold respectively. Therefore, light sources such as red LEDs, white LEDs and FL affected the accumulation of GSLs in rocket salad.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.366-373
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• 2000

Toxin production and low digestibility of cyanobacteria are known to cause low exploitability of cyanobacteria by zooplankton. In this study, we compared relative tolerance and compatibility of zooplankton taxa in eight eutrophic lakes, exposed to frequent cyanobacterial blooms, uring the summer season of 1999. Microcystis, Anabaena, Oscillatoria and Phormidium were common cyanobacteria in all lakes. with relatively lower $NO_3-N$ concentration (<0.2 mgN/l) and TN/TP ratio (<20), compared with other lakes where colonial cyanobacteria dominated. Rotifers were dominant zooplankton in most lakes, and among them, Keratella, Polyarthra and Hexathra were common. The laboratory feeding experiment showed that relative copepods that greatly decreased (90%) after 4 day when cyanobacteria were used as the food source of zooplankton, while rotifers gradually increased with the change of dominant taxa from Keratella through Pompholyx to Monostyla. These results suggest that rotifers may be capable of coexisting with cyanobacteria by exploiting them for the food source.

• Childhood Kidney Diseases
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• v.6 no.2
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• pp.155-168
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• 2002

Purpose; Systemic lupus erythematosus(SLE) is an autoimmune disease with multi-system involvement and renal damage is a major cause of morbidity and mortality in children. Renal involvement is more common and severe in children than in adults. Therefore, renal biopsy plays a crucial role in planning effective therapy. In this study, we investigated the clinical and pathological findings of lupus nephritis in children to aid clinical care of the disease. Methods: The clinical and pathological data of 40 patients who were diagnosed as SLE with renal involvement in Shinchon Severance Hospital from Jan. 1990 to Sep. 2002 were analyzed retrospectively. Results: The ratio of male to female patients was 1:3 and the median age at diagnosis was 12.1(2-18) years old. FANA(95.0%), anti-ds DNA antibody(87.5%), malar rash(80.0%) were the most common findings among the classification criteria by ARA. Microscopic hematuria with proteinuria(75.0%), nephrotic syndrome(55.0%), and microscopic hematuria alone(15.0%) were the most common renal presentations in the respective order at diagnosis. There were 27 cases with WHO class IV lupus nephritis confirmed by renal biopsy and 3 cases with pathological changes of WHO class type. Different treatment modalities were carried out : prednisolone only in 5 cases, prednisol-one+azat-hioprine in 9 cases, prednisolone+azathioprine+intravenous cyclophosphamide in 14 cases, prednisolone+cyclosporine A+intravenous cyclophosphamide in 12 cases, plasma exchange in 9 cases and intravenous gamma-globulin in 2 cases. The average follow-up period was $51.8{\pm}40.5$ months. During $51.8{\pm}40.5$ months. During follow-up, 4 patients expired. The risk factors associated with mortality were male, WHO class IV and acute renal failure at diagnosis. Conclusion: Renal involvement was noted in 63.5% of childhood SLE, and 67.5% of renal lesion was WHO class IV lupus nephritis which is known to be associated with a poor prognosis. Therefore aggressive treatment employing immunosuppressant during the early stages of disease could be helpful in improving long-term prognosis. But careful attention should be given to optimize the treatment due to unique problems associated with growth, psychosocial development and gonadal toxicity, especially in children.

• Childhood Kidney Diseases
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• v.6 no.2
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• pp.209-217
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• 2002

Purpose : Corticosteroid has been used as the mainstay therapy of childhood NS. But SIO is one of the serious complications of long-term steroid therapy, especially in growing children. Recently calcium, calcitonin, PTH, vitamin D and bisphosphonate has been used to treat or prevent SIO in adult, which is rare in children with NS. We studied the effect of $1{\alpha}-(OH)D_3$ and Pamidronate on SIO using dual energy X-ray absorptiometry (DEXA). Patients and methods : We studied thirty patients who admitted in the Dept. of Pediatrics of Kyung Hee Medical Hospital with NS. All patients was received longterm steroid therapy. There was no history of bone, liver, or endocrine disease. The samples, serum protein, albumin, BUN, creatinine, calcium, phosphorus, and BMD were obtained before and the six months after the dose of $1{\alpha}-(OH)D_3$ and Pamidronate, respectively Results : The mean age was $6.9{\pm}3.3\;and\;6.5{\pm}2.5$ years old. The mean duration of steroid therapy was $28.8{\pm}1.8\;and\;27.6{\pm}1.0$ months. The changes of serum protein, albumin, BUN, creatinine, calcium and phosphorus level between pre-treatment and post-treatment did not show statistical significance in both $1{\alpha}-(OH)D_3$ and Pamidronate treatment group. However, BMD was increased in both from $0.472{\pm}0.12\;and\;0.457{\pm}0.10\;g/cm^2\;to\;0.533{\pm}0.12$ and $0.529{\pm}0.09\;g/cm^2$ after treatment. (P<0.05) Conclusion : Both $1{\alpha}-(OH)D_3$ and Pamidronate appears to be effective in treating and preventing SIO in children with nephrotic syndrome requiring long-term steroid therapy.