• Title/Summary/Keyword: Acid and base

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Synthesis of Optically Active 1-Aminoalkylphosphonic Acids (光學 活性을 갖는 1-Aminoalkylphosphonic Acid 의 合成)

  • Sung Ki Cho;Yong Joon Kim
    • Journal of the Korean Chemical Society
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    • v.33 no.2
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    • pp.257-262
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    • 1989
  • An efficient asymmetric synthesis of (+)-1-aminoalkyphosphonic acids is achieved by alkylation of Schiff base, prepared from diethylaminomethylphosphonate and (S)-(-)-2-hydroxypinan-3-one as a chiral reagent, and a new method of column chromatographic resolution of (${\pm}$)-1-aminobenzylphosphonic acid via its Schiff base with (S)-(-)-2-hydroxypinan-3-one is described.

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On the reaction of nucleic acid deerivatives with rhodium (II) (isobutyrate)$_4L_2$

  • Yu, Byung-Sul;Kim, Bak-Kwang
    • Archives of Pharmacal Research
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    • v.1 no.1
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    • pp.1-6
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    • 1978
  • Rhodium (II) (isobutyrate)$_{4}L_2$, an antinumor drug, was shown to reactr with nucleic acid base derivatives, A, G, U and C in chloroform solution. When these derivatives were treated with one of novel metal compounds, rhodium carboxylate in chloroform solution, a fairly strong complex formation was observed by spectroscopic techniques. The characteristic of these complex was that binding occured at the two axial positions of rhodium (II) (isobutyrate)$_{4}L_2$ to the NH or )$NH_2$ group of the base in the ligands.

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Effect of surface treatment methods on the shear bond strength of auto-polymerized resin to thermoplastic denture base polymer

  • Koodaryan, Roodabeh;Hafezeqoran, Ali
    • The Journal of Advanced Prosthodontics
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    • v.8 no.6
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    • pp.504-510
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    • 2016
  • PURPOSE. Polyamide polymers do not provide sufficient bond strength to auto-polymerized resins for repairing fractured denture or replacing dislodged denture teeth. Limited treatment methods have been developed to improve the bond strength between auto-polymerized reline resins and polyamide denture base materials. The objective of the present study was to evaluate the effect of surface modification by acetic acid on surface characteristics and bond strength of reline resin to polyamide denture base. MATERIALS AND METHODS. 84 polyamide specimens were divided into three surface treatment groups (n=28): control (N), silica-coated (S), and acid-treated (A). Two different auto-polymerized reline resins GC and Triplex resins were bonded to the samples (subgroups T and G, respectively, n=14). The specimens were subjected to shear bond strength test after they were stored in distilled water for 1 week and thermo-cycled for 5000 cycles. Data were analyzed with independent t-test, two-way analysis of variance (ANOVA), and Tukey's post hoc multiple comparison test (${\alpha}=.05$). RESULTS. The bond strength values of A and S were significantly higher than those of N (P<.001 for both). However, statistically significant difference was not observed between group A and group S. According to the independent Student's t-test, the shear bond strength values of AT were significantly higher than those of AG (P<.001). CONCLUSION. The surface treatment of polyamide denture base materials with acetic acid may be an efficient and cost-effective method for increasing the shear bond strength to auto-polymerized reline resin.

In vitro Arsanilic Acid Induction of Apoptosis in Rat Hepatocytes

  • Yuan, Hui;Gong, Zhi;Yuan, li-Yun;Han, Bo;Han, Hong-Ryul
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.9
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    • pp.1328-1334
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    • 2006
  • This paper aimed to study the toxicity of arsanilic acid on rat primary hepatocytes in vitro by a modification of the perfusion method. The conditions included concentrations of 0, 1.085, 10.85, 108.5, 1,085 and 10,850 mg/kg arsanilic acid in RPMI 1,640 medium at rat hepatocytes plates respectively, each group had five repeats at $37^{\circ}C$ for 48 h. The rat primary hepatocytes survival ratio, DNA Ladder, activities of glutathione peroxidase (GSH-px), superoxide dismutase (SOD) and catalase (CAT) in hepatocytes, activity of SOD in the medium and the expression of gene bax in hepatocytes were measured at 12 h, 24 h and 48 h respectively. The results showed that arsanilic acid decreased the activities of GSH-px and SOD, and increased the activity of CAT in all dosages, and affected as positive DNA ladder. Although the SOD activities of both hepatocytes and medium in 1.085 mg/L arsanilic acid were significantly lower than the base line at 12 h, CAT activity in 10.85 mg/L arsanilic acid was significantly higher than the base line at 48 h, and all of the DNA ladders were positive, which means 1.085 mg/L arsanilic acid induced apoptosis at 24 h. The gene expression of bax was significantly upregulated in 1.085 mg/L arsanilic acid or higher for 24 h.The parameters in 1,085 mg/L and 10,850 mg/L arsanilic acid had more severe changes than the others at any time indicating that these levels of arsanilic acid were toxic hazards for hepatocyte survival. It was concluded that arsanilic acid induced a dosage- and time-dependent gene expression of bax, 1.085 mg/L arsanilic acid could be involved in rat liver cell apoptosis at 24 h. Arsanilic acid as additives in livestock feed could present potential toxic implications for farm animals.

Comparison of Surface Characteristics and Adsorption Characteristics of Activated Carbons Changed by Acid and Base Modification (산과 염기의 개질에 의해 변화된 활성탄의 표면특성과 흡착특성 비교)

  • Lee, Song-Woo;Lee, Min-Gyu;Park, Sang-Bo
    • Journal of Environmental Science International
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    • v.17 no.5
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    • pp.565-571
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    • 2008
  • The surface properties of activated carbon modified by acids and base were studied. The influence of the surface chemistry on the adsorption of benzene and acetone vapor on modified activated carbons has been investigated The modified activated carbons were obtained by treatment with acetic acid ($CH_3COOH$), nitric acid ($HNO_3$) and sodium hydroxide (NaOH). The modified activated carbons had similar porosity but different surface chemistry and adsorption characteristics. The total surface acidity (sum of functional groups) of activated carbon (AC-AN) treated by nitric acid was 2.6 times larger than that of activated carbon (AC) before the acid treatment. Especially, carboxyl group was much developed by nitric acid treatment. The benzene equilibrium adsorption capacity of AC-AN decreased 20% more than that of AC. However, the acetone equilibrium adsorption capacity of AC-AN increased 20% more than that of AC because of the large increase of carboxyl group and acidity.

A comparison of the Effects of Intravenous Fluid Warming and Skin Surface Warming on Peri-operative Body Temperature and Acid Base Balance of Elderly Patients with Abdominal Surgery (수액가온요법과 피부가온요법이 개복술 환자의 저체온 예방에 미치는 효과 비교)

  • Park, Hyo-Sun;Yoon, Hae-Sang
    • Journal of Korean Academy of Nursing
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    • v.37 no.7
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    • pp.1061-1072
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    • 2007
  • Purpose: The purpose of this study was to compare the effects of intravenous fluid warming and skin surface warming on peri-operative body temperature and acid base balance of abdominal surgical patients under general anesthesia. Method: Data collection was performed from January 4th, to May 31, 2004. The intravenous fluid warming(IFW) group(30 elderly patients) was warmed through an IV line by an Animec set to $37^{\circ}C$. The skin surface warming(SSW) group(30 elderly patients) was warmed by a circulating-water blanket set to $38^{\circ}C$ under the back and a 60W heating lamp 40 cm above the chest. The warming continued from induction of general anesthesia to two hours after completion of surgery. Collected data was analyzed using Repeated Measures ANOVA, and Bonferroni methods. Results: SSW was more effective than IFW in preventing hypothermia(p= .043), preventing a decrease of $HCO_3{^-}$(p= .000) and preventing base excess(p= .000) respectively. However, there was no difference in pH between the SSW and IFW(p= .401) groups. Conclusion: We conclude that skin surface warming is more effective in preventing hypothermia, and $HCO_3{^-}$ and base excess during general anesthesia, and returning to normal body temperature after surgery than intravenous fluid warming; however, skin surface warming wasn't able to sustain a normal body temperature in elderly patients undergoing abdominal surgery under general anesthesia.

Comparison of Phenyl Ethylamine and Hyamine Base as an Absorbent of $Carbon^{14}$ Dioxide ($C^{14}O_2$의 흡수제(吸收劑)로서 폐닐에칠아민과 하이아민베이스의 비교(比較))

  • Chiang, Yun-Hwan
    • Applied Biological Chemistry
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    • v.14 no.1
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    • pp.51-57
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    • 1971
  • In order to compare their absorption abilities of carbon dioxide, Hyamine base and phenyl ethylamine were employed in wet combustion experiments. The known content of liver lipid and uniformly mixed palmitic $acid-C^{14}$ were oxidized with sulfuric acid and phosphoric acid. Carbon dioxide produced was trapped by the amines tested through thin tube. The amines absorbed carbon dioxide were mixed with diotal scintillator and counted by liquid scintillation counter. The counting efficiencies and radioactivity recoveries were 50 to 60 % and nearly 100 % for both amines. However, the absorption ability of carbon dioxide by phenyl ethylamine was about two times that of Hyamine base. This technique would not be necessary for the counting of liver lipid of swim, because the efficiencies were not increased and counting accuracies were similar to those of direct counting.

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Effect of Acid-Base Characteristics of Carbon Black Surfaces on Mechanical Behaviors of EPDM Matrix Composites (카본블랙 표면의 산-염기 특성변화가 카본블랙/EPDM 복합재료의 기계적 특성에 미치는 영향)

  • Park Soo-Jin;Kang Jin-Young;Hong Sung-Kwon
    • Polymer(Korea)
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    • v.29 no.2
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    • pp.151-155
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    • 2005
  • The effect of acid-base treatments of carbon blacks (CBs) was investigated in the mechanical properties of CBs/rubber composites. The surface characteristics of the CBs were determined by the pH, acid-base values, and surface energetics. Their mechanical properties of the composites were also evaluated by the crosslink density $(V_e)$ and tearing energy (T). As an experimental result, acidically treated CBs led to the increase of the specific component $({\gamma}s^{sp})$, resulting in decreasing the mechanical properties of the composites. However, basically treated CBs showed a higher value of the dispersive component $({\gamma}s^L)$ than that of the untreated or acidically treated CBs. It was also found that the interaction of the CBs-rubber was improved, resulting in the improvement of the crosslink density and mechanical properties of the composites. It was then remarked that the acid-base characteristics of the CB surfaces made an important role in improving the physical properties of the rubber matrix composites.

A study for Solubilization and Bioavailability of Sewage Sludge Using the Complex Pre-treatment (복합 전처리를 통한 하수슬러지의 가용화 및 생물학적 유용성에 관한 연구)

  • Kang, Jung-Hyun;Lee, Hee-Soo;Lee, Tae-Jin
    • Journal of the Korea Organic Resources Recycling Association
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    • v.19 no.3
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    • pp.35-43
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    • 2011
  • In this study, anaerobic biological decomposition were attempted after solubilization treatment of sewage sludge with the complex pre-treatment (acid/base treatment with ultrasonic radiation). Solubilization ratios were compared for ultrasonic treatment at acid or base condition. Solubilization effect of the complex pre-treatment was more effective at higher pH. Biological decomposition of complex pre-treated sludge was faster than non treated (raw) sludge, showing 10 times higher total gas production. Biological digestion of the sludge shows more biogas production. B/A ratio. which indicates hydrogen production potential, was 50% higher with complex pre-treated sludge than raw sludge but lactic acid or propionic acid were also detected during anaerobic decomposition process.

Interfacial Evaluation of Modified Jute and Hemp Fibers/Polypropylene (PP)-Maleic Anhydride Polypropylene Copolymers (PP-MAPP) Composites Using Micromechanical Test and Nondestructive Acoustic Emission (Micromechanical 시험법과 음향방출을 이용한 Flax 와 Hemp 섬유 강화 에폭시 복합재료의 계명 물성 평가)

  • Son, Tran Quang;Hwang, Byung-Sun;Park, Joung-Man
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2005.11a
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    • pp.157-160
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    • 2005
  • The surface energies and acid-base interaction between the untreated and treated Jute or Hemp fibers and different matrix compositions of polypropylene-maleic anhydride polypropylene copolymers (PP-MAPP) were investigated using dynamic contact angle measurement. The contribution of the acid-base property into the interfacial adhesion of the natural fibers/matrix systems were characterized by calculating the work adhesion coming from the acid-base interaction. On the other hand, microfailure mechanism of both single Jute and Hemp fiber bundles were investigated using the combination of single fiber tensile test and acoustic emission. Distinctly different micro failure modes of the different natural fiber/polypropylene systems wet ε observed using optical microscope and determined indirectly by AE and their FFT analysis.

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