• Title/Summary/Keyword: pK$_a$ Values

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THE EFFECT OF INTERNAL IMPLANT-ABUTMENT CONNECTION AND DIAMETER ON SCREW LOOSENING

  • Ha, Chun-Yeo;Kim, Chang-Whe;Lim, Young-Jun;Jang, Kyung-Soo
    • The Journal of Korean Academy of Prosthodontics
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    • v.43 no.3
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    • pp.379-392
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    • 2005
  • Statement of problem. One of the common problems of dental implant prosthesis is the loosening of the screw that connects each component, and this problem is more common in single implant-supported prostheses with external connection, and in molars. Purpose. The purposes of this study were: (1) to compare the initial abutment screw detorque values of the six different implant-abutment interface designs, (2) to compare the detorque values of the six different implant-abutment interface designs after cyclic loading, (3) to compare the detorque values of regular and wide diameter implants and (4) to compare the initial detorque values with the detorque values after cyclic loading. Material and methods. Six different implant-abutment connection systems were used. The cement retained abutment and titanium screw of each system were assembled and tightened to 32Ncm with digital torque gauge. After 10 minutes, initial detorque values were measured. The custom titanium crown were cemented temporarily and a cyclic sine curve load(20 to 320N, 14Hz) was applied. The detorque values were measured after cyclic loading of one million times by loading machine. One-way ANOVA test, scheffe’s test and Mann-Whitney U test were used. Results. The results were as follows : 1. The initial detorque values of six different implant-abutment connections were not significantly different(p>0.05). 2. The detorque values after one million dynamic cyclic loading were significantly different (p<0.05). 3. The SS-II regular and wide implant both recorded the higher detorque values than other groups after cyclic loading(p<0.05). 4. Of the wide implants, the initial detorque values of Avana Self Tapping Implant, MIS and Tapered Screw Vent, and the detorque values of MIS implant after cyclic loading were higher than their regular counterparts(p<0.05). 5. After cyclic loading, SS-II regular and wide implants showed higher detorque values than before(p<0.05).

The Influence of Service Marketing Mix on Eating-out Customers' Perceptions Values(Focused on Family Restaurants in Seoul) (패밀리레스토랑의 서비스마케팅믹스가 외식고객의 가치에 미치는 영향 (서울지역의 패밀리레스토랑을 위주로))

  • Yoon, Tae-Hwan
    • Korean journal of food and cookery science
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    • v.25 no.3
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    • pp.306-316
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    • 2009
  • The purpose of this study was to investigate the influence of service marketing mix on customers' perceptions of values at family restaurants in Seoul. Frequency analysis, ANOVA, reliability analysis, factor analysis, multi-regression analysis were employed to analyze the data. First, perceptions for items such as food (p<.001), price (p<.001), process (p<.001), and employees were significantly different with regard to monthly spending money, and food (p<.001), physical evidence (p<.001), and employees (p<.001) were also significantly different by partner. All of the mixes (food, price, place, employees p<.001; promotion, process, physical evidence p<.05) had positive influences on the customers' monetary and overall values. And the mixes of place p<.001; price and employees p<.01; and food, process and physical evidence p<.05 negatively affected non-monetary values, whereas promotion had a positive influence. As a result, we conclude that the service marketing mix is an efficient marketing tactic to remove intangible factors from restaurant businesses. Likewise it is highly recommended that food-service companies manage the marketing mix in a customerfriendly manner to minimize the negative characteristics of services toward customers, and to promote the customer appreciation of family restaurants.

Synthesis and Characterization of HPMC Derivatives as Novel Duodenum-Specific Coating Agents

  • Huang Yuan;Zheng ling Ii;Liu Jun;Zhang Zhi rong
    • Archives of Pharmacal Research
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    • v.28 no.3
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    • pp.364-369
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    • 2005
  • HPMC (Hydroxypropyl methylcellulose) was chemically modified, using maleic anhydrides, to obtain pH-sensitive HPMCAM (Hydroxypropyl methylcellulose acetate maleate) polymers for use as novel duodenum-specific coating agents. The pharmaceutical properties of HPMCAM, such as film forming, acid values, pH-sensitive values, water vapor permeability, tensile strength and Tg, were investigated, and found to show good film forming properties. The pH­sensitive values were 3.0 to 3.7. In vitro results demonstrate that HPMCAM could completely suppress drug release within 2h in a simulated gastric fluid (pH 1.2) and rapidly release the drug in a simulated pathological duodenal fluid (pH 3.4). These results indicate that HPMCAM might be a useful material for a duodenum-specific drug delivery system.

Functional Characterization of Pharmcogenetic Variants of Human Cytochrome P450 2C9 in Korean Populations

  • Cho, Myung-A;Yoon, Jihoon G.;Kim, Vitchan;Kim, Harim;Lee, Rowoon;Lee, Min Goo;Kim, Donghak
    • Biomolecules & Therapeutics
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    • v.27 no.6
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    • pp.577-583
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    • 2019
  • Human cytochrome P450 2C9 is a highly polymorphic enzyme that is required for drug and xenobiotic metabolism. Here, we studied eleven P450 2C9 genetic variants-including three novel variants F69S, L310V, and Q324X-that were clinically identified in Korean patients. P450 2C9 variant enzymes were expressed in Escherichia coli and their bicistronic membrane fractions were prepared The CO-binding spectra were obtained for nine enzyme variants, indicating P450 holoenzymes, but not for the M02 (L90P) variant. The M11 (Q324X) variant could not be expressed due to an early nonsense mutation. LC-MS/MS analysis was performed to measure the catalytic activities of the P450 2C9 variants, using diclofenac as a substrate. Steady-state kinetic analysis revealed that the catalytic efficiency of all nine P450 2C9 variants was lower than that of the wild type P450 2C9 enzyme. The M05 (R150L) and M06 (P279T) variants showed high $k_{cat}$ values; however, their $K_m$ values were also high. As the M01 (F69S), M03 (R124Q), M04 (R125H), M08 (I359L), M09 (I359T), and M10 (A477T) variants exhibited higher $K_m$ and lower $k_{cat}$ values than that of the wild type enzyme, their catalytic efficiency decreased by approximately 50-fold compared to the wild type enzyme. Furthermore, the novel variant M07 (L310V) showed lower $k_{cat}$ and $K_m$ values than the wild type enzyme, which resulted in its decreased (80%) catalytic efficiency. The X-ray crystal structure of P450 2C9 revealed the presence of mutations in the residues surrounding the substrate-binding cavity. Functional characterization of these genetic variants can help understand the pharmacogenetic outcomes.

The Effect of Electroacupuncture at the PC6(Naegwan) and TE5 (Oegwan) on the EEG (내관, 외관 전침 자극이 뇌파변화에 미치는 영향)

  • Yim, Jin-Teck;Kim, Su-Hyun;Lee, Sang-Ryong
    • Journal of Pharmacopuncture
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    • v.6 no.3
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    • pp.91-106
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    • 2003
  • Objectives : The aim of this study was to examine the effects of electroacupuncture(EA) at the PC6(Naegwan) and the TE5 (Oegwan) on nounal humans using power spectral analysis. Methods : EEG power spectrum exhibit site-specific and state-related differences in specific frequency bands. In this study, power spectrum was used as a measure of complexity. 30 channel EEG study was carried out in 30 subjects(30 males ; age=23.7 years). Results : In ${\alpha}$(alpha) band, the power values at F7 channels(p<0.05) during the PC6-acupoint treatment were significantly were decreased. In ${\beta}$(beta) band, the power values at Fp1, Fz, TT1, T5, P3, P4, Po1, P02, O1, Oz, O2 channels(p<0.05) during the non-acupoint treatment and at Fp1, F4, F8 channels(p<0.05) during the TE5-acupoint treatment significantly were increased. In ${\theta}$(theta) band, the power values at Fp1 channels(p<0.05) during the non-acupoint treatment and at Oz channels(p<0.05) the TE5-acupoint treatment significantly were increased. but, the power values at F7 channels(p<0.05) during the non-acupoint treatment were significantly were decreased. In ${\delta}$(delta) band, the power values at TCP1, TCP2, CP1, T5 channels(p<0.05) during PC6-acupoint treatment were increased and the power values at F7, TT2 channels(p<0.05) during non-acupoint treatment were increased. but, the power values at the TE5-acupoint treatment significantly was decreased than the before-acupuncture treatment.

pH and Colour Characteristics of Carcasses of Broilers Fed with Dietary Probiotics and Slaughtered at Different Ages

  • Karaoglu, Mevulut;Aksu, M.I.;Esenbuga, N.;Macit, M.;Durdag, H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.4
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    • pp.605-610
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    • 2006
  • The objective of the present experiment was to determine the effects of slaughtering at different ages and the use of a commercial probiotic (115-Biogallinox) in broiler diets on the color properties of carcasses, during the first 24 h following slaughter. Ross 308 male broiler chickens obtained from a commercial hatchery were raised to either 35 or 42 days of age. Chickens were fed with different levels of probiotic ($P_0$: 0.0%, $P_1$: 0.1% and $P_2$: 0.2%) containing Saccharomyces cerevisiae during the experimental period. At the end of the trial all birds were slaughtered and then stored at $3^{\circ}C$ for 24 h. The pH and skin colour of carcasses were determined 1, 3, 7, 10, 13, 17 and 24 h after slaughter. Although the use of probiotic and post-mortem ageing time affected the pH (p<0.01), it was not affected by slaughter age (35 and 42 days) (p>0.05). The highest pH values occurred in carcasses of broilers fed 0.2% probiotic. The pH values of carcasses decreased with post-mortem ageing time (p<0.01). Main factors (treatment, slaughter age and post-mortem ageing time) had an effect on colour ($L^*$, $a^*$ and $b^*$) values (p<0.01). $L^*$ values of 42d-old slaughter and $P_2$ group were lower than those of 35d-old slaughter and other probiotic groups. The $a^*$ and $b^*$ values of 35d-old slaughter were lower than those of 42d-old slauhgter. The $a^*$ and $b^*$ values increased during post-mortem ageing (p<0.01). It was determined that changing of the colour traits of broiler carcasses was correlated with probiotic, pH and post-mortem ageing time. Also, it was observed that darkness of carcass colour increased as time progressed.

A comparison of bone bed preparation with laser and conventional drill on the relationship between implant stability quotient (ISQ) values and implant insertion variables

  • Lee, Su-Young;Piao, Chunmei;Heo, Seong-Joo;Koak, Jai-Young;Lee, Joo-Hee;Kim, Tae-Hyung;Kim, Myung-Joo;Kwon, Ho-Beom;Kim, Seong-Kyun
    • The Journal of Advanced Prosthodontics
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    • v.2 no.4
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    • pp.148-153
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    • 2010
  • PURPOSE. The aim of this study was to investigate a comparison of implant bone bed preparation with Er,Cr:YSGG laser and conventional drills on the relationship between implant stability quotient (ISQ) values and implant insertion variables. MATERIALS AND METHODS. Forty implants were inserted into two different types of pig rib bone. One group was prepared with conventional drills and a total of 20 implants were inserted into type I and type II bone. The other group was prepared with a Er,Cr:YSGG laser and a total of 20 implants were inserted into type I and type II bone. ISQ, maximum insertion torque, angular momentum, and insertion torque energy values were measured. RESULTS. The mean values for variables were significantly higher in type I bone than in type II bone (P < .01). In type I bone, the ISQ values in the drill group were significantly higher than in the laser group (P < .05). In type II bone, the ISQ values in the laser group were significantly higher than in the drill group (P < .01). In both type I and type II bone, the maximum insertion torque, total energy, and total angular momentum values between the drill and laser groups did not differ significantly (P ${\geq}$ .05). The ISQ values were correlated with maximum insertion torque (P < .01, r = .731), total energy (P < .01, r = .696), and angular momentum (P < .01, r = .696). CONCLUSION. Within the limitations of this study, the effects of bone bed preparation with Er,Cr:YSGG laser on the relationship between implant stability quotient (ISQ) values and implant insertion variables were comparable to those of drilling.

Hematological and biochemical analysis of Korean indigenous cattle according to the ages (한우의 연령에 따른 혈액 및 혈청 화학치 분석)

  • Cho, Hyun-Ung;Ko, Won-Seuk;Son, Hyong-Won;Lee, Mi-Jin;Song, Hee-Jong;Park, Jin-Ho
    • Korean Journal of Veterinary Service
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    • v.31 no.1
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    • pp.137-147
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    • 2008
  • Investigations for hematologic and biochemical values and the differential count of WBC for Korean indigenous cattle (KIC)is rarely performed. Therefore, when the index of complete blood counts (CBC) and biochemical analysis of KIC was requested, it had many difficulties to make the results for blood condition since the standard hematologic and biochemical values of KIC are lacking. In the present study, we have investigated the hematologic and biochemical values and the differential count of WBC for blood of total 252 KIC and 17 striped cattle (SC) as a control. As a result, the mean values of RBC and platelet of KIC were significantly decreased by age (P<0.05). The mean values of RBC, HCT, MCV and MCHC between KIC and SC of the same age (2 - 3 years) showed the statistical significance (P<0.05). Also, in the WBC of KIC, the mean values were decreased according to the age from $12.8{\times}10^3/{\mu}l$ under 1 year to $8.5{\times}10^3/{\mu}l$ over 5 years. In the differential count of WBC of KIC, it showed generally the rates of 45% lymphocyte and 35% segmented neutrophil. In the biochemical analysis, the mean values of BUN and globulin were significantly increased according to the age (P<0.05). Additionally, in comparative analysis between pregnant and non-pregnant group of KIC, the mean values of Hg and HCT in pregnant group were significantly decreased (P<0.05). In conclusion, data obtained from this study may be valuable as a standard for interpretation of the results in hematologic and biochemical analysis of KIC.

A study on the ethical values of dental hygiene students (치위생학생의 윤리적 가치관에 관한 연구)

  • Kang, Boo-Wol
    • Journal of Korean society of Dental Hygiene
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    • v.10 no.1
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    • pp.1-18
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    • 2010
  • Objectives : The purpose of this study was to examine the ethical values of dental hygiene students and set up the way of ethic educationin educational course. Methods: The subjects in this study were 948 students in four colleges located in the metropolitan area, on whom a survey was conducted. Results : 1. Regarding values of human life, they got a mean of 3.01, which showed that they sort of took a deontological view. 2. As to values of dental hygiene duties, they got a mean of 3.62, which indicated that they took a deontological view. 3. Concerning values of clients, they got a mean of 3.22, which implied that they took a deontological view. 4. As for values of collaborators, they got a mean of 3.90, which denoted that they took a very deontological view. 5. In regard to correlation among each part of their ethical values, there was a very significant correlation between their views of dental hygiene duties and human life, and between their views of clients and collaborators(p<.001). 6. As to the relationship of general characteristics to ethical values, they took a significantly different view of human life according to academic year(p<.05), religion(p<.001), religious enthusiasm(p<.0010) and attitude to the occupation of dental hygienist(p<.001). Academic year Conclusions : Regardings ethical values of dental hygiene students which showed that they took a deontological view than autilitarianism view in all parts. Accordingly, In order to establish desirable ethical values, it was scrutinized that reinforcement of education on biomedical ethics and professional ethics in curriculum was needed.

Effect of Using Vegetable Powders as Nitrite/Nitrate Sources on the Physicochemical Characteristics of Cooked Pork Products

  • Jeong, Jong Youn;Bae, Su Min;Yoon, Jiye;Jeong, Da Hun;Gwak, Seung Hwa
    • Food Science of Animal Resources
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    • v.40 no.5
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    • pp.831-843
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    • 2020
  • This study investigated the potential for using vegetable powders as a natural replacement for sodium nitrite and their effects on the physicochemical characteristics of alternatively cured pork products. We analyzed pork products subjected to four treatments: control (0.015% sodium nitrite), Chinese cabbabe powder (CCP) treatment (0.4% Chinese cabbage powder), radish powder (RP) treatment (0.4% radish powder), and spinach powder (SP) treatment (0.4% spinach powder). Among the vegetable powders prepared in this study, SP had the highest (p<0.05) nitrate content, while CCP had the lowest (p<0.05). The cooking yields from these treatments were not significantly different from each other. However, the products with vegetable powders had higher (p<0.05) pH and thiobarbituric acid reactive substances values than the control. Pork products with vegetable powders also showed lower CIE L values and higher CIE b values than the nitrite-added control. RP treatment had similar (p>0.05) CIE a values to the control, while SP treatment had the lowest (p<0.05) CIE a values. The residual nitrite content was lower (p<0.05) in the vegetable powder added pork products than in the control, although nitrosyl hemochrome and total pigment contents in the CCP and RP treatments were similar (p>0.05) to those in the control. The control, CCP, and RP treatments showed curing efficiencies greater than 80%, indicating that CCP and RP would be promising potential replacements for sodium nitrite. The results of this study suggest that RP may be a suitable natural replacement for sodium nitrite to produce alternatively cured meat products, compared to other leafy vegetable powders.