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An Experimental Study on the Biomechanical Effectiveness of Bone Cement-Augmented Pedicle Screw Fixation with Various Types of Fenestrations

  • Yoon, Sang Hoon;Lee, Sang Hyung;Jahng, Tae-Ahn
    • Journal of Korean Neurosurgical Society
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    • v.65 no.6
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    • pp.779-789
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    • 2022
  • Objective : To analyze the effects of the number and shape of fenestrations on the mechanical strength of pedicle screws and the effects of bone cement augmentation (BCA) on the pull-out strength (POS) of screws used in conventional BCA. Methods : For the control group, a conventional screw was defined as C1, a screw with cannulated end-holes was defined as C2, a C2 screw with six pinholes was defined as C3, and the control group type was set. Among the experimental screws, T1 was designed using symmetrically placed thru-hole type fenestrations with an elliptical shape, while T2 was designed with half-moon (HM)-shaped asymmetrical fenestrations. T3 and T4 were designed with single HM-shaped fenestrations covering three pitches and five pitches, respectively. T5 and T6 were designed with 0.6-mm and 1-mm wider fenestrations than T3. BCA was performed by injecting 3 mL of commercial bone cement in the screw, and mechanical strength and POS tests were performed according to ASTM F1717 and ASTM F543 standards. Synthetic bone (model #1522-505) made of polyurethane foam was used as a model of osteoporotic bone, and radiographic examinations were performed using computed tomography and fluoroscopy. Results : In the fatigue test, at 75% ultimate load, fractures occurred 7781 and 9189 times; at 50%, they occurred 36122 and 82067 times; and at 25%, no fractures occurred. The mean ultimate load for each screw type was 219.1±52.39 N for T1, 234.74±15.9 N for T2, 220.70±59.23 N for T3, 216.45±32.4 N for T4, 181.55±54.78 N for T5, and 216.47±29.25 N for T6. In comparison with C1, T1, T2, T3, T4, and T6 showed significantly different ultimate load values (p<0.05). However, when the values for C2 and the fenestrated screws were evaluated with an unpaired t test, the ultimate load value of C2 significantly differed only from that of T2 (p=0.025). The ultimate load value of C3 differed significantly from those of T1 and T2 (C3 vs. T1 : p=0.048; C3 vs. T2 : p<0.001). Linear correlation analysis revealed a significant correlation between the fenestration area and the volume of bone cement (Pearson's correlation coefficient r=0.288, p=0.036). The bone cement volume and ultimate load significantly correlated with each other in linear correlation analysis (r=0.403, p=0.003). Conclusion : Fenestration yielded a superior ultimate load in comparison with standard BCA using a conventional screw. In T2 screws with asymmetrical two-way fenestrations showed the maximal increase in ultimate load. The fenestrated screws can be expected to show a stable position for the formation of the cement mass.

HARDY-LITTLEWOOD MAXIMAL FUNCTIONS IN ORLICZ SPACES

  • Yoo, Yoon-Jae
    • Bulletin of the Korean Mathematical Society
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    • v.36 no.2
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    • pp.225-231
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    • 1999
  • Let Mf(x) be the Hardy-Littlewood maximal function on $\mathbb{R}^n$. Let $\Phi$ and $\Psi$ be functions satisfying $\Phi$(t) = ${\int^t}_0$a(s)ds and $\Psi(t)$ = ${\int^t}_0$b(s)ds, where a(s) and b(s) are positive continuous such that ${\int^\infty}_0\frac{a(s)}{s}ds$ = $\infty$ and b(s) is quasi-increasing. We show that if there exists a constant $c_1$ so that ${\int^s}_0\frac{a(t)}{t}dt\;c_1b(c_1s)$ for all $s\geq0$, then there exists a constant $c_1$ such that(0.1) $\int_{\mathbb{R^{n}}$ $\Phi(Mf(x))dx\;\leq\;c_2$ $\int_\mathbb{R^{n}}$$\Psi(c_2\midf(x)\mid)dx$ for all $f\epsilonL^1(R^n_$. Conversely, if there exists a constant $c_2$ satisfying the condition (0.1), then there exists a constant $c_1$ so that ${\int^s}_\delta\frac{a(t)}{t}dt=;\leq\;c_1b(c_1s$ for all $\delta$ > 0 and $s\geq\delta$.

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Flavobacterium jocheonensis sp. nov., Isolated from Marine Green Alga Ulva pertusa

  • Choi, Ha Ri;Park, So Hyun;Heo, Moon Soo
    • Journal of Microbiology and Biotechnology
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    • v.29 no.8
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    • pp.1266-1272
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    • 2019
  • A bacterial strain, labeled $UR11^T$, was isolated from green alga Ulva pertusa collected from Jeju Island, Korea. $UR11^T$ was identified as a gram-negative, rod-shaped, motile by gliding and aerobic bacterial strain with yellow colonies on R2A plates. The strain $UR11^T$ grew over at a temperature range of $10^{\circ}C$ to $30^{\circ}C$ (optimally at $25^{\circ}C$), a pH range of 6.0-11 (optimally at pH 7.0) and a Nacl range of 0.5-5% Nacl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain $UR11^T$ was a member of the genus Flavobacterium. Strain $UR11^T$ shared close similarity with F. jejuensis $EC11^T$ (98.0%) F. jumunjinense $HME7102^T$ (96.1%), F. haoranii $LQY-7^T$ (95.3%), F. dongtanense $LW30^T$ (95.1%), and F. ahnfeltiae 10Alg $130^T$(94.9%). The major fatty acids (>5%) were $iso-C_{15:0}$ (33.9%), $iso-C_{15:1}$ G (12.4%), $iso-C_{17:0}$ 3-OH (9.0%), $isoC_{16:0}$ (7.0%) and $iso-C_{15:0}$ 3-OH (6.3%). The major polar lipids were phosphatidylethanolamine, seven unknown aminolipids, two unknown aminopolarlipids and two unknown lipids. DNA-DNA hybridization value was 58% at strain $UR11^T$ with F. jejuensis $EC11^T$. Based on phenotypic, chemotaxonomic and phylogenetic evidence, strain $UR11^T$ represents a novel species of the genus Flavobacterium, for which the name Flavobacterium jocheonensis sp. nov. is proposed. The type strain is Flavobacterium jocheonensis is $UR11^T$ (=KCTC $52377^T$ =JCM $31512^T$).

An existence of solutions for an infinte diffusion constant

  • Ham, Yoon-Mee
    • Bulletin of the Korean Mathematical Society
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    • v.33 no.4
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    • pp.631-638
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    • 1996
  • The parabolic free boundary problem with Puschino dynamics is given by (see in [3]) $$ (1) { \upsilon_t = D\upsilon_{xx} - (c_1 + b)\upsilon + c_1 H(x - s(t)) for (x,t) \in \Omega^- \cup \Omega^+, { \upsilon_x(0,t) = 0 = \upsilon_x(1,t) for t > 0, { \upsilon(x,0) = \upsilon_0(x) for 0 \leq x \leq 1, { \tau\frac{dt}{ds} = C)\upsilon(s(t),t)) for t > 0, { s(0) = s_0, 0 < s_0 < 1, $$ where $\upsilon(x,t)$ and $\upsilon_x(x,t)$ are assumed continuous in $\Omega = (0,1) \times (0, \infty)$.

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Effect of the Cultivation Method and Cutting Time on the Growth Characteristics, Dry Matter Yield and Voluntary Intake in Sorghum X Sudangrass Hybrid (재배방식과 예취시기가 수수 X 수단그라스 교잡종의 생육특성, 건물수량 및 사일리지 채식성에 미치는 영향)

  • Lee Sang Moo
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.25 no.1
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    • pp.7-16
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    • 2005
  • This experiments were carried out to determine growth characteristics, dry matter yield and voluntary intake of silage according to growth stage of Sorghum$\times$sudangrass(SSH) hybrid in mono-cropping and inter-cropping(C; com, T1; cutting of SSH at milk stage. T2; cutting of SSH at dough stage, T3; cutting of SSH at yellow ripe stage, T4; cutting of SSH and soybean at milk stage, T5; cutting of SSH and soybean at dough stage, T6: cutting of SSH and soybean at yellow ripe stage). Results obtained from these experiments are as follows; Plant length and leaf length of SSH(T2, T3, T4. T5 and T6)) were higher than C. T1 treatment was lower than it. C showed $2.3\~2.9$ times higher stem diameter as 29.5mm compare to SSH(T1, T2, T3, T4, T5 and T6). soybean(T4, T5 and T6) was lower in $4.3\~5.4$ times. But SSH of inter-cropping treatment(T4, T5 and T6) showed highly comparing with mono-cropping(T1, T2 and T3) at the same maturity. Leaf rate and stem hardness of SSH(T1, T2, T3, T4, T5 and T6) were lower than C. The fresh yield was high line with T2(72,320kg/ha), T1(69,103kg/ha), T3(68,333kg/ha) and C(57,988kg/ha), dry matter yield was high in line with T3(22.413kg/ha), T2(21,479kg/ha), C(19,252kg/ha) and T6(18,175kg/ha), (P<0.05). Protein dry matter yield was higher in T3(1,434kg/ha), C(1,386kg/ha)T5 and T6(1,345kg/ha) it was lower in T1(872kg/ha), (P<0.05). Crude protein of silage of T4 and T5 was higher than C, T2 and T3 were lower than it(P<0.05), while NDF content was not different. ADF content of T6 was higher than those of the other treatment. The highest hemi-cellulose among treatments was shown in T1 whereas T6 showed the lowest. Fresh intake of silge was 160.4, 155.8, 168.7, 172.9, 132.9, 158.7 and 185.2 g/BW for C, T1, T2, T3, T4, T5 and T6, respectively. Dry matter intake was high in line with T6(60.3g), C(153.8g), T3(53.6g), T5(47.8g), T2(46.8g), T4(35.2g) and T1(34.48g/BW), (P<0.05). Crude protein intake was high in line with T6(3.9g), T5(3.4g), C(3.4g), T2(2.9g), T3(2.9g), T4(2.6g) and T1(2.3g/BW), (P<0.05). As mentioned above the results, mono-cropping(T3) and inter-cropping(T5 and T6) could be recommended as increasing method of sorghum $\times$ sudangrass hybrid silage utilization when silage intake of dry matter and crude protein were considered.

EVALUATION OF CONDYLAR POSITION USING COMPUTED TOMOGRAPH FOLLOWING BILATERAL SAGITTAL SPLIT RAMUS OSTEOTOMY (전산화단층촬영법을 이용한 하악 전돌증 환자의 하악지 시상 골절단술후 하악과두 위치변화 분석)

  • Chol, Kang-Young;Lee, Sang-Han
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.18 no.4
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    • pp.570-593
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    • 1996
  • This study was intended to perform the influence of condyle positional change after surgical correction of skeletal Class III malocclusion after BSSRO in 20 patients(males 9, females 11) using computed tomogram that were taken in centric occlusion before, immediate, and long term after surgery and lateral cephalogram that were taken in centric occlusion before, 7 days within the period intermaxillary fixation, 24hour after removing intermaxillary fixation and long term after surgery. 1. Mean intercondylar distance was $84.45{\pm}4.01mm$ and horizontal long axis of condylar angle was $11.89{\pm}5.19^{\circ}$on right, $11.65{\pm}2.09^{\circ}$on left side and condylar lateral poles were located about 12mm and medial poles about 7mm from reference line(AA') on the axial tomograph. Mean intercondylar distance was $84.43{\pm}3.96mm$ and vertical axis angle of condylar angle was $78.72{\pm}3.43^{\circ}$on right, $78.09{\pm}6.12^{\circ}$on left. 2. No statistical significance was found on the condylar change(T2C-T1C) but it had definitive increasing tendency. There was significant decreasing of the distance between both condylar pole and the AA'(p<0.05) during the long term(TLC-T2C). 3. On the lateral cephalogram, no statistical significance was found between immediate after surgery and 24 hours after the removing of intermaxillary fixation but only the lower incisor tip moved forward about 0.33mm(p<0.05). Considering individual relapse rate, mean relapse rate was 1.2% on L1, 5.0% on B, 2.0% on Pog, 9.1% on Gn, 10.3% on Me(p<0.05). 4. There was statistical significance on the influence of the mandibular set-back to the total mandibular relapse(p<0.05). 5. There was no statistical significance on the influence of the mandibular set-back(T2-T1) to the condylar change(T2C-T1C), the condylar change(T2C-T1C, TLC-T2C) to the mandibular total relapse, the pre-operative condylar position to the condylar change(T2C-T1C, TLC-T2C), the pre-operative mandibular posture to the condylar change(T2C-T1C, TLC-T2C)(p>0.05). 6. The result of multiple regression analysis on the influence of the pre-operative condylar position to the total mandibular relapse revealed that the more increasing of intercondylar distance and condylar vertical axis angle and decreasing of condyalr head long axis angle, the more increasing of mandibular horizontal relapse(L1,B,Pog,Gn,Me) on the right side condyle. The same result was founded in the case of horizontal relapse(L1,Me) on the left side condyle.(p<0.05). 7. The result of multiple regression analysis on the influence of the pre-operative condylar position to the pre-operative mandibular posture revealed that the more increasing of intercondylar distance and condylar vertical axis angle and decreasing of condylar head long axis angle, the more increasing of mandibular vertical length on the right side condyle. and increasing of vertical lengh & prognathism on the left side condyle(p<0.05). 8. The result of simple regression analysis on the influence of the pre-operative mandibular posture to the mandibular total relapse revealed that the more increasing of prognathism, the more increasing of mandibular total relapse in B and the more increasing of over-jet the more increasing of mandibular total relapse(p<0.05). Consequently, surgical mandibular repositioning was not significantly influenced to the change of condylar position with condylar reposition method.

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Comparison of Single and Double Combination of Temperature-time in Sous Vide Treated Semitendinosus Muscle from Cattle and Goat

  • Ismail, Ishamri;Hwang, Young-Hwa;Joo, Seon-Tea
    • Food Science of Animal Resources
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    • v.39 no.1
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    • pp.45-53
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    • 2019
  • This study observed the effects of the double combination of temperatures-times (2 temperatures: 2 times combination, 2T2T) in sous vide cooking method on the physicochemical properties and collagen solubility (CS) of semitendinosus muscle from cattle and goat as a comparison to common sous vide treatment (1 temperature: 1 time combination, 1T1T). The new invention of sous vide cooking method (2T2T) cooked at the first temperature at $45^{\circ}C$ for 3 h, and the second temperature at $60^{\circ}C$, $65^{\circ}C$, and $70^{\circ}C$ for 3 h, and labeled as N45-60, N45-65, and N45-70, respectively. While, common sous vide treatment (1T1T) were cooked directly for 6 h at $60^{\circ}C$ (T60), $65^{\circ}C$ (T65), and $70^{\circ}C$ (T70). Results revealed that cooking with 2T2T treatment improved the water-holding capacity and reduced the cooking loss of both beef and goat meat. The $L^*$ values have no apparent changes between treatment in beef and goat meat, while $a^*$ values of N45-60 treated goat presented markedly higher values than other treatments but an only slight increase in beef at the same treatment (p>0.05). Again, 2T2T treatment tended to decrease mean shear force (SF) values for beef and goat meat with the lowest SF values recorded at N45-60, and the CS no or less influenced this value. Therefore, the application of innovative sous vides cooking method (2T2T) presented comparable values in the treated beef and goat meat as compared to common sous vide method (1T1T).

Matrix Metalloproteinase-9 -1562T Allele and its Combination with MMP-2 -735 C Allele are Risk Factors for Breast Cancer

  • Rahimi, Zohreh;Yari, Kheirolah;Rahimi, Ziba
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.3
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    • pp.1175-1179
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    • 2015
  • Background: Expression of matrix metalloproteinases (MMPs) is up-regulated in human cancers. The aim of present study was to investigate the role of MMP-9 C-1562T polymorphism and its interaction with MMP-2 C-735T polymorphism in susceptibility to breast cancer in a population from Western Iran with Kurdish ethnic background. Materials and Methods: The study sample of 205 individuals consisted of 101 breast cancer patients and 104 healthy subjects. MMP-9 C-1562T and MMP-2 C-735T variants were identified using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results: Among 67.4% of studied patients the breast cancer developed in the third and forth decades of the life. The frequency of MMP-9 T allele was 17.3% in patients and 10.1% in controls. The presence of T allele significantly increased the risk of breast cancer by 1.87-fold [OR=1.87 (95% CI 1.05-3.33, p=0.035)]. The frequency of MMP-9 CT+TT genotype tended to be higher in those patients with a family history of cancer in first degree-relatives (36.8%) than those without a family history (28.3%, p=0.37). We observed an interaction between the MMP-9 -1562 T allele with MMP-2 -735 C allele that significantly increased the risk of breast cancer [OR=1.42 (95% CI 1.02-1.98, p=0.036)]. Conclusions: The present study demonstrated that MMP-9 C-1562T polymorphism alone and in combination with MMP-2 C-735T polymorphism increased the risk of breast cancer that might be a useful biomarker in identifying women at risk of developing breast cancer. Also, this study revealed that in most women from Western Iran breast cancer presents in third and fourth decades of life.

Studies on the Yeast-Like Fungi Associated with Bovine Mastitis 1. Epidemiological Study (유우유방염(乳牛乳房炎)에 관여(關與)하는 효모양진균(酵母樣眞菌)에 관한 연구(硏究) 1. 역학적(疫學的)인 조사(調査))

  • Yeo, Sang-Geon;Choi, Won-Pil
    • Korean Journal of Veterinary Research
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    • v.22 no.2
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    • pp.121-138
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    • 1982
  • The present study was conducted in order to investigate the role of yeast-like fungi in bovine mastitis. Attempts were made to isolate and identify yeast-like fungi from the milk from normal udders and those with clinical or subclinical mastitis and from feces. Also incuded in the study were trials for the pathogenicity of the isolates for laboratory animals and efficacy of an anti-fungal drug for the treatment of mastitis. A total of 133 isolates of yeast-like fungi was made from milk and feces and they were identified as Candida (C.) albicans (5 isolates), C. krusei (63 isolates), C. tropicalis (27 isolates), Torulopsis (T.) glabrata (10 isolates), Rhodotourla sp. (6 isolates), Hansenula sp. (6 isolates) and Pichia sp. (1 isolate). Sixty seven strains of yeast-like fungi were isolated from the milk of 64 quarters (4.3% of quarters examined) of 55 cows (14.3% of cows examined). C. krusei, C. tropicalis, C. pseudotropicalis, C. parapsilosis and T. glabrata were isolated as the causative agents from 20 quarters (1.3% of quarters examined) with clinical mastitis. C. krusei, C. tropicalis, C. albicans, C. pseudotropicalis, T. glabrata, Rhodotorula sp. and Hansenula sp. were isolated as the causative agents from 22 quarters (1.5% quarters examined) with subclinical mastitis. C. tropicalis, C. krusei, T. glabrata and Rhodotorula sp. were isolated as the contaminants from 22 normal quarters (1.5% of quarters examined). C. krusei, C albicans, C. tropicalis, C. pseudotropicalis, C. parapsilosis, T. glabrata, Hansenula sp., Rhodotorula sp. and Pichia sp. were isolated as the contaminants from feces and all of the species except Pichia sp. were isolated from milk of the same cows at the some time. Intramammary infusion of nystatin was effective for the treatment of mastitis caused by C. albicans, C. krusei, C. tropicalis, C. pseudotoropicalis, C. parapsilosis, T. glabrata and Rhodotorula sp. C. albicans, C. krusei, C. tropicalis, C. pseudotropicalis, T. glabrata, Hamsenula sp. and Pichia sp. were pathogenic for rat but C. parapsilosis and Rhodotorula sp. were not.

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Estimation of Carbon Storage in Three Cool-Temperate Broad-Leaved Deciduous Forests at Jirisan National Park, Korea (지리산국립공원 낙엽활엽수림 세 군락의 탄소저장량 평가)

  • Lee, Na-Yeon
    • Korean Journal of Environmental Biology
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    • v.30 no.2
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    • pp.121-127
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    • 2012
  • Cool-temperate broad-leaved deciduous forests are one of dominant forest cover types in Asia monsoon climate regions. However, our understanding of how much storages carbon in these ecosystems is limited. We studied carbon storage in three cool-temperate broad-leaved deciduous forests at Jirisan National Park, Korea. The biomass of trees in the three stands on an average was $112tC\;ha^{-1}$ and ranged from 107 to $119tC\;ha^{-1}$. The total amount of soil organic matter at a depth of 30 cm in the three stands on an average was $66tC\;ha^{-1}$. In addition, the total carbon stocks of biomass and soil was approximately $178tC\;ha^{-1}$, ranged from 167 to $184tC\;ha^{-1}$. Above values among three stands did not show the valuable difference at Jirisan National Park. The amounts of carbon storage in three ecosystems at Jirisan National Park, were higher than those of other studies significantly, except Seoraksan National Park.