• Title/Summary/Keyword: Effective Strain

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Mutation of rpsL Gene in Streptomycin-Resistant Pseudomonas syringae pv. actinidiae Biovar 3 Strains Isolated from Korea (국내에서 분리된 Streptomycin 저항성 Pseudomonas syringae pv. actinidiae Biovar 3 균주에서 rpsL 유전자의 돌연변이)

  • Lee, Young Sun;Kim, Gyoung Hee;Koh, Young Jin;Jung, Jae Sung
    • Research in Plant Disease
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    • v.28 no.1
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    • pp.26-31
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    • 2022
  • Pseudomonas syringae pv. actinidiae (Psa) is the causal agent responsible for the bacterial canker disease of kiwifruit plants. Psa strains are divided into five different biovars based on genetic and biochemical characteristics. Among them, biovar 2 and 3 strains of Psa were isolated and have been causing widespread damages in Korea. One of the most effective ways to control Psa is to use an antibiotic such as streptomycin. However, Psa strains resistant to this antibiotic were isolated in Korea, and an earlier study revealed that the resistance in the biovar 2 is associated with strA-strB genes. This study aimed to determine the molecular resistance mechanism of Psa biovar 3 strains to streptomycin. Sequencing the rpsL gene encoding ribosomal protein S12 from three streptomycin-resistant strains screened in the laboratory revealed that a spontaneous mutation occurred either at codon 43 or 88. Meanwhile, in four streptomycin-resistant strains of Psa biovar 3 isolated from two kiwifruit orchards, a single nucleotide in codon 43 of the rpsL, which is AAA in streptomycin-sensitive strain, was substituted for AGA causing an amino acid change from lysine to arginine. The resistant mechanism in all biovar 3 strains obtained in Korea was identified as a mutation of the rpsL gene.

Automated Finite Element Analyses for Structural Integrated Systems (통합 구조 시스템의 유한요소해석 자동화)

  • Chongyul Yoon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.37 no.1
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    • pp.49-56
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    • 2024
  • An automated dynamic structural analysis module stands as a crucial element within a structural integrated mitigation system. This module must deliver prompt real-time responses to enable timely actions, such as evacuation or warnings, in response to the severity posed by the structural system. The finite element method, a widely adopted approximate structural analysis approach globally, owes its popularity in part to its user-friendly nature. However, the computational efficiency and accuracy of results depend on the user-provided finite element mesh, with the number of elements and their quality playing pivotal roles. This paper introduces a computationally efficient adaptive mesh generation scheme that optimally combines the h-method of node movement and the r-method of element division for mesh refinement. Adaptive mesh generation schemes automatically create finite element meshes, and in this case, representative strain values for a given mesh are employed for error estimates. When applied to dynamic problems analyzed in the time domain, meshes need to be modified at each time step, considering a few hundred or thousand steps. The algorithm's specifics are demonstrated through a standard cantilever beam example subjected to a concentrated load at the free end. Additionally, a portal frame example showcases the generation of various robust meshes. These examples illustrate the adaptive algorithm's capability to produce robust meshes, ensuring reasonable accuracy and efficient computing time. Moreover, the study highlights the potential for the scheme's effective application in complex structural dynamic problems, such as those subjected to seismic or erratic wind loads. It also emphasizes its suitability for general nonlinear analysis problems, establishing the versatility and reliability of the proposed adaptive mesh generation scheme.

The Use of the Internal Transcribed Spacer Region for Phylogenetic Analysis of the Microsporidian Parasite Enterocytozoon hepatopenaei Infecting Whiteleg Shrimp (Penaeus vannamei) and for the Development of a Nested PCR as Its Diagnostic Tool

  • Ju Hee Lee;Hye Jin Jeon;Sangsu Seo;Chorong Lee;Bumkeun Kim;Dong-Mi Kwak;Man Hee Rhee;Patharapol Piamsomboon;Yani Lestari Nuraini;Chang Uook Je;Seon Young Park;Ji Hyung Kim;Jee Eun Han
    • Journal of Microbiology and Biotechnology
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    • v.34 no.5
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    • pp.1146-1153
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    • 2024
  • The increasing economic losses associated with growth retardation caused by Enterocytozoon hepatopenaei (EHP), a microsporidian parasite infecting penaeid shrimp, require effective monitoring. The internal transcribed spacer (ITS)-1 region, the non-coding region of ribosomal clusters between 18S and 5.8S rRNA genes, is widely used in phylogenetic studies due to its high variability. In this study, the ITS-1 region sequence (~600-bp) of EHP was first identified, and primers for a polymerase chain reaction (PCR) assay targeting that sequence were designed. A newly developed nested-PCR method successfully detected the EHP in various shrimp (Penaeus vannamei and P. monodon) and related samples, including water and feces collected from Indonesia, Thailand, South Korea, India, and Malaysia. The primers did not cross-react with other hosts and pathogens, and this PCR assay is more sensitive than existing PCR detection methods targeting the small subunit ribosomal RNA (SSU rRNA) and spore wall protein (SWP) genes. Phylogenetic analysis based on the ITS-1 sequences indicated that the Indonesian strain was distinct (86.2% nucleotide sequence identity) from other strains collected from Thailand and South Korea, and also showed the internal diversity among Thailand (N = 7, divided into four branches) and South Korean (N = 5, divided into two branches) samples. The results revealed the ability of the ITS-1 region to determine the genetic diversity of EHP from different geographical origins.

Studies on the Production of Alcohol from Woods (목재(木材)를 이용(利用)한 Alcohol 생산(生産)에 관(關)한 연구(硏究))

  • Cheong, Jin Cheol
    • Journal of Korean Society of Forest Science
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    • v.59 no.1
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    • pp.67-91
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    • 1983
  • In order to examine the alcohol production from softwoods (Pinus densiflora Sieb. et Zucc., Pinus rigida Miller, Larix leptolepis Gordon) and hardwoods (Alnus japonica Steud., Castanea crenata Sieb. et Zucc. Populus euramericana CV 214), chemical compositions were analyzed and conditions of acid hydrolysis with wood meals were established. Also strains which could remarkably decompose the cellulose were identified, and conditions of cellulase production of strains, characteristics of cellulase, and alcohol fermentation were examined. The results were summarized as follows. 1) In acid hydrolysis of wood, the high yield of reducing sugars was shown from 1.0% to 2.0% of hydrochloric acid and 2.0% of sulfuric acid. The highest yield was produced 23.4% at wood meals of Alnus japonica treated with 1.0% of hydrochloric acid. 2) The effect of raising the hydrolysis was good at $1.5kg/cm^2$, 30 times (acid/wood meal), and 45 min in treating hydrochloric acid and 30 min in treating sulfuric acid. 3) The pretreatments with concentrated sulfuric acid were more effective concentration ranged from 50% to 60% than that with hydrochloric acid and its concentration ranged from 50% to 60%. 4) The quantative analysis of sugar composition of acid hydrolysates revealed that glucose and arabinose were assayed 137.78mg and 68.24mg with Pinus densiflora, and 102.22mg and 65.89mg with Alnus janonica, respectively. Also xylose and galactose were derived. 5) The two strains of yeast which showed remarkably high alcohol productivity were Saccharomyces cerevisiae JAFM 101 and Sacch. cerevisiae var. ellipsoldeus JAFM 125. 6) The production of alcohol and the growth of yeasts were effective with the neutralization of acid hydrolysates by $CaCO_3$ and NaOH. Production of alcohol was excellent in being fermented between pH 4.5-5.5 at $30^{\circ}C$ and growth of yeasts between pH 5.0-6.0 at $24^{\circ}C$. 7) The production of alcohol was effective with the addition of 0.02% $(NH_2)_2CO$ and $(NH_4)_2SO_4$, 0.1% $KH_2PO_4$, 0.05% $MgSO_4$, 0.025% $CaCl_2$, 0.02% $MnCl_2$. Growth of yeasts was effective with 0.04-0.06% $(NH_2)_2CO$ and $(NH_4)_2SO_4$, 0.2% $K_2HPO_4$ and $K_3PO_4$, 0.05% $MgSO_4$, 0.025% $CaCl_2$, and 0.002% NaCl. 8) Among various vitamins, the production of alcohol was effective with the addition to pyridoxine and riboflavin, and the growth of yeasts with the addition to thiamin, Ca-pantothenate, and biotin. The production of aocohol was increased in 0.1% concentration of tannin and furfural, but mas decreased in above concentration. 9) In 100ml of fermented solution, alcohol and yeast were produced 2.201-2.275ml and 84-114mg for wood meals of Pinus densiflora, and 2.075-2.125ml and 104-128mg for that of Alnus japonica. Residual sugars were 0.55-0.60g and 0.60-0.65g for wood meals of Pinus densiflora and Alnus japonica, respectively, and pH varied from 3.3 to 3.6. 10) A strain of Trichoderma viride JJK. 107 was selected and identified as its having the highest activity of decomposing cellulose. 11) The highest cellulase production was good when CMCase incubated for 5 days at pH 6.0, $30^{\circ}C$ and xylanase at pH 5.0, $35^{\circ}C$. The optimum conditions of cellulase activity were proper in case of CMCase at pH 4.5, $50^{\circ}C$ and xylanase at pH 4.5, $40^{\circ}C$. 12) In fermentation with enzymatic hydrolysates, the peracetic acid treatment for delignification showed the best yields of alcohol and its ratio was effective with the addition of about 10 times. 13) The production of alcohol was excellent when wood meals and Koji of wheat bran was mixed with 10 to 8 and the 10g of wood meals of Pinus densiflora produced 2.01-2.14ml of alcohol and Alnus japonica 2.11-2.20ml.

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Symbiotic effectiveness and intrinsic antibiotic resistance of Rhizobium meliloti populated in Korean pasture soils (국내(國內) 초지토양(草地土壤)에 분포(分布)한 Rhizobium meliloti의 질소고정력(窒素固定力)과 항균제반응(抗菌劑反應) 특성(特性))

  • Kang, Ui-Gum;Ha, Ho-Sung;Jung, Yeun-Tae
    • Applied Biological Chemistry
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    • v.35 no.3
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    • pp.179-185
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    • 1992
  • Rhizobium meliloti populated in five Korean pasture soils were characterized by symbiotic effectiveness and intrinsic antibiotic resistance using whole-soil inoculum and 11 antibiotics, respectively. Most probable number (MPN) of naturalized rhizobia counted with alfalfa Vernal[Medicago sativa (L.)] as a host ranged $1.7{\times}10^2\;cells/g$. soil(Chunghyo, Kyeongiu)-$1.0{\times}10^5\;cells/g$. soil(Gampo, Kyeongiu) and ended to be positively associated with soil pH. On the whole, the effectiveness of population as compared to TAL mix inoculum (TAL 380+TAL 1372+TAL 1373) was very low. Nevertheless, there were two highly effective strains, YCK 539 and YCK 542, which were not inferior to TAL 1372, from Ogpo, Dalseong among the total of 30 of 6 isolates per each soil. As long as mean $N_2$ fixing ability of each soil isolate, the isolates from Hyeongog, Kyeonju were outstanding and the rest were in order of Ogpo, Dalseong>Chunghyo, Kyeongju>Hwaweon, Dalseong>Gampo, Kyeongiu. Isolates as a whole were resistant to erythromycin(67崙), nalidixic acid(77%), and streptomycin sulfate(8051), which had the concentration of $100\;{\mu}g/ml$, $160\;{\mu}g/ml$, and $10\;{\mu}g/ml$, respectively and divided into 14 patterns of resistance. Association between resistances in each soil was not clear. And there was no relationship of resistance pattern to effectiveness. The best effective strain YCKa 542 exclusively fell into No. X pattern having resistance to erythromycin, nalidixic acid, and neomycin sulfate.

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Biological Activities and Bioactive Compounds in the Extract of Acer tegmentosum Maxim. Stem (산겨릅나무 줄기추출물의 생리활성 및 유효성분 분리)

  • Hong, Bo-Kyong;Eom, Seok-Hyun;Lee, Chan-Ok;Lee, Ji-Won;Jeong, Jong-Hyun;Kim, Jae-Kwang;Cho, Dong-Ha;Yu, Chang-Yeon;Kwon, Yong-Soo;Kim, Myong-Jo
    • Korean Journal of Medicinal Crop Science
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    • v.15 no.4
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    • pp.296-303
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    • 2007
  • Acer tegmentosum (Acereaceae) has been used a source of traditional medicines for the treatment of hepatic disorders in Korea. This research was conducted to determine biofunctional activities of A. tegmentosum stem extract and to identify its bioactive components. Methanolic extract from A. tegmentosum stem was partitioned by using organic solvents, including n-hexane, ethyl acetate, n-butanol, and water. Two compounds were isolated by using an ODS column chromatography from ethyl acetate soluble fraction shown to the strongest antioxidant activity ($RC_{50}=3.15\;{\mu}g/m{\ell}$) among the fractions. The isolated compounds were analyzed by $^1H$ and $^{13}C$ NMR, IR, UV/VIS, MS spectrum data and identified as catechin, ${\rho}-Hydroxyphenethyl$ alcohol $1-O-{\beta}-_D-(6'-O-galloyl)-glucopyranoside$. The compounds have shown strong antioxidant activity, with similar activity to BHA ($RC_{50}=2\;{\mu}g/m{\ell}$). Especially, ${\rho}-Hydroxyphenethyl$ alcohol 1-O-{\beta}-_D-(6'-O-galloyl)-glucopyranoside$ was shown strong anti-lipid peroxidative activity. However, the compounds were not shown antimicrobial activities. In antimicrobial activity assays, ethyl acetate soluble fraction was effective to bacterial inhibition, such as Escherichia coli and Klebsiella pneumonia, with minimum inhibitory concentrations in $125\;{\mu}g/m{\ell}$. Otherwise, antifungal activity against Candida albicans was shown in n-hexane soluble fraction exhibiting $63\;{\mu}g/m{\ell}$ of minimum inhibitory concentration. In anticomplementary activity assays, water soluble fraction was the most effective exhibiting 24% inhibitory activity.

Biological Control of the Mushroom Fly, Lycoriella mali, Using Bacillus thuringiensis subsp. israelensis (Bacillus thuringiensis subsp. israelensis를 이용한 느타리 재배에서 버섯파리의 생물학적 방제)

  • Moon, Byung-Ju;Lee, Su-Hee;Lim, Eun-Kyung;Kim, Tae-Sung;Kim, Hyun-Ju;Song, Ju-Hee;Kim, Ik-Soo
    • The Korean Journal of Mycology
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    • v.30 no.1
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    • pp.50-55
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    • 2002
  • Biological control against mushroom fly, Lycoriella mali, was performed by using Bacillus thuringiensis subsp. israelensis Bti-D and Bti-U, isolated from dead mushroom fly in oyster mushroom houses. Control values of the bacterial strains Bti-D and Bti-U against L. mali in bottle culture of oyster mushroom were 74.4% and 64.2%, respectively, and the value in small tray culture were 75.8% and 56.8%, respectively. In the experiment to develop the mass, cheap media for Bti-D and Bti-U isolates, the Biji broth (bean curd residue, called Biji in Korean language) was selected as a culture medium for an inexpensive and mass cultivation by the measurement of optical density of the two bacteria grown in the different media tested. Insecticidal effect of the formulation contained different ingredients that were prepared by using the Bti-D strain cultured in the Biji broth was tested in tray and bottle culture of oyster mushroom. The WCS formulation that contained corn starch as bio-gel (86.4%) was more effective to control the mushroom fly than living cells (69.1%) in bottle culture of oyster mushroom. Moreover, insecticidal effect of the WCS formulation was improved when water of pH 8 was used for dilution of the formulation. Effect of the WCS formulation using water of pH 8 and chemicals, Zuron (dimillin) W.P. on the control of mushroom fly and the productivity of oyster mushroom was investigated in tray culture of oyster mushroom. The Zuron W.P. was more effective to control the mushroom fly than the WCS formulation. However, compared with no treatment, the productivity of the mushroom treated with the WCS formulation was improved than that of the mushroom with Zuron W.P.

Effects of Platycodon grandiflorum Extract on Blood Glucose and Lipid Composition in Alloxan Induced Hyperglycemic Rats (도라지 추출액이 Alloxan 유발 당뇨성 흰쥐의 혈당 및 지질성분에 미치는 영향)

  • 성낙주;이수정;신정혜;이일숙;정영철
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.25 no.6
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    • pp.986-992
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    • 1996
  • This study was designed to observe the effects of the feeding Platycodon grandiflorum(6 or 22 years) extract on the improvement of the blood glucose, lipids in the serum and liver of alloxaninduced hyperglycemic rats(S.D. strain, ♂), alloxan monohydrate 15mg/kg B.W./day I.P. injection) for 3 weeks. Concentrations of blood glucose were significantly higher in the alloxan administration(I.P.) groups(groups 2, 3 and 4) than those in the control group(group 1, basal diet). Blood glucose concentrations were remarkably lower in the group 3(basa1+alloxan+6years Platycodon grandiflorum) and 4(basa1+alloxan+22years Platycodon grandiflorum) than those in the group 2(basal+alloxan), and particularly, lower in the group 4. Concentrations of total cholesterol and LDL-cholesterol in serum were significantly lower in the groups 3, 4 than those in the group 2, and remarkably, lower in the group 4 than those in the group 3. Concentrations of HDL-cholesterol in serum were tile highest in the group 1. Those in the groups 3 and 4 were higher than those in the group 2. Atherosclerotic index were lower in the group 3, 4 than those in the group 2. In the alloxan-induced diabetic groups(groups 2, 3, 4), the serum free cholesterol, cholesterol ester, triglyceride and phospholipid concentrations were significantly lower in the group 3, 4 than those in the group 2. Contents of total cholesterol, triglyceride and phospholipid in liver were remarkably lower in the all experimental groups than those in the group 2. The activities of aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase In serum were the highest in the group 2, but the other groups were rather lower. From the above research, the Platycodon grandiflorum(6 or 22 years) extracts were effective on the improvement of the blood glucose, lipid compositions in serum and liver. And particularly, Platycodon grandiflorum(22 years) was more effective than those in the Platycodon grandiflorum(6 years).

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Conversion of Fermented Feed by Basidiomycetes (담자균(擔子菌)을 이용(利用)한 발효(醱酵) 사료(飼料)에 관한 연구(硏究))

  • Hong, Jae-Sik;Kim, Joong-Man;Jeong, Jin-Chul;Lee, Tae-Kyu;Kim, Dong-Han;Kim, Myung-Kon;Lee, Keug-Ro
    • The Korean Journal of Mycology
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    • v.13 no.3
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    • pp.157-168
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    • 1985
  • To investigate nutritive values of a feed fermented with basidiomycetes, among the isolated strains, Lyophyllum decastes (Fr.) Sing. was found with the greatest enzyme productivity and rapid mycelial growth in rice straw medium. Optimum temperature, pH and moisture content for mycelial growth and enzyme production of the strain were $25{\sim}30^{\circ}C,\;pH\;4.0{\sim}7.0\;and\;70{\sim}75\;%$, respectively. Fifteen days of culture were required for the highest enzyme productivity. Among the sub-materials added, $30{\sim}40\;%$ of rice bran and $10{\sim}20\;%$ of defatted perilla seeds were effective for the enzyme production, but caused a reduced mycelial growth. The greatest effect of an addition of inorganic salts was obtained with $0.36{\sim}0.72\;%\;of\;(NH_4)_2HPO_4$. When 40 mesh or smaller rice straw and steam treatment at $0.5\;kg/cm^2$ were used, the mycelial growth decreased, whereas the enzyme production increased. The mycelial growth and enzyme production increased when $Ca(OH)_2$ was used as the alkali treatment, but decreased with increasing concentration of NaOH. As the fermentation proceeded, the amounts of ash, reducing sugar and total nitrogen increased, but cellulose, lignin and pentosan decreased. When the rice straw was treated with alkali, the amounts of ash, total nitrogen and lignin decreased, but reducing sugar and cellulose increased. At higher NaOH concentration, the variation become greater. The in vitro dry matter digestibility of the products increased from 55.03 % at the beginning of the fermentation to 62.72 % at 45 days after fermentation. The most effective alkali treatment on the digestibility of rice straw was KOH followed by NaOH. However, the digestibility increased with increasing concentration of NaOH. The digestibility of pretreated with alkali increased after fermentation as well.

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A Biomechanical Study on a New Surgical Procedure for the Treatment of Intertrochanteric Fractures in relation to Osteoporosis of Varying Degrees (대퇴골 전자간 골절의 새로운 수술기법에 관한 생체역학적 분석)

  • 김봉주;이성재;권순용;탁계래;이권용
    • Journal of Biomedical Engineering Research
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    • v.24 no.5
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    • pp.401-410
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    • 2003
  • This study investigates the biomechanical efficacies of various cement augmentation techniques with or without pressurization for varying degrees of osteoporotic femur. For this study, a biomechanical analysis using a finite element method (FEM) was undertaken to evaluate surgical procedures, Simulated models include the non-cemented(i.e., hip screw only, Type I), the cement-augmented(Type II), and the cemented augmented with pressurization(Type III) models. To simulate the fracture plane and other interfacial regions, 3-D contact elements were used with appropriate friction coefficients. Material properties of the cancellous bone were varied to accommodate varying degrees of osteoporosis(Singh indices, II∼V). For each model. the following items were analyzed to investigate the effect surgical procedures in relation to osteoporosis of varying degrees : (a) von Mises stress distribution within the femoral head in terms of volumetric percentages. (b) Peak von Mises stress(PVMS) within the femoral head and the surgical constructs. (c) Maximum von Mises strain(MVMS) within the femoral head, (d) micromotions at the fracture plane and at the interfacial region between surgical construct and surrounding bone. Type III showed the lowest PVMS and MVMS at the cancellous bone near the bone-construct interface regardless of bone densities. an indication of its least likelihood of construct loosening due to failure of the host bone. Particularly, its efficacy was more prominent when the bone density level was low. Micromotions at the interfacial surgical construct was lowest in Type III. followed by Type I and Type II. They were about 15-20% of other types. which suggested that pressurization was most effective in limiting the interfacial motion. Our results demonstrated the cement augmentation with hip screw could be more effective when used with pressurization technique for the treatment of intertrochanteric fractures. For patients with low bone density. its effectiveness can be more pronounced in limiting construct loosening and promoting bone union.