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      • Identification and quantification of seven volatile n-nitrosamines in cosmetics using gas chromatography/chemical ionization-mass spectrometry coupled with head space-solid phase microextraction

        Choi, N.R.,Kim, Y.P.,Ji, W.H.,Hwang, G.S.,Ahn, Y.G. Pergamon Press ; Elsevier Science Ltd 2016 Talanta Vol.148 No.-

        <P>An analytical method was developed for the identification and quantification of seven volatile n-nitrosamines (n-nitrosodimethylamine [NDMA], n-nitrosoethylmethylamine [NMEA], n-nitrosodiethylamine [NDEA], n-nitrosodipropylamine [NDPA], n-nitrosodibutylamine [NDBA], n-nitrosopiperidine [NPIP], and n-nitrosopyrrolidine [NPYRD]) in water insoluble cream type cosmetics. It was found that the head space-solid phase microextraction (HS-SPME) was suitable for extraction, clean up, and pre-concentration of n-nitrosamines in the cream type samples so its optimal conditions were investigated. Identification and quantification of n-nitrosamines using single quadrupole gas chromatography/mass spectrometry (GC/MS) in chemical ionization (CI) mode were carried out with accurate mass measurements. Their accurate masses of protonated molecular ions were obtained within 10 mDa of the theoretical masses when sufficiently high signal was acquired from the unique calibration method using mass and isotope accuracy. For the method validation of quantification, spiking experiments were carried out to determine the linearity, recovery, and method detection limit (MDL) using three deuterated internal standards. The average recovery was 79% within 20% relative standard deviation (RSD) at the concentration of 50 ng/g. MDLs ranged from 0.46 ng/g to 36.54 ng/g, which was satisfactory for the directive limit of 50 ng/g proposed by the European Commission (EC). As a result, it was concluded that the method could be provided for the accurate mass screening, confirmation, and quantification of n-nitrosamines when applied to cosmetic inspection. (C) 2015 Elsevier B.V. All rights reserved.</P>

      • SCISCIESCOPUS

        Gα<sub>12</sub> gep oncogene deregulation of p53-responsive microRNAs promotes epithelial–mesenchymal transition of hepatocellular carcinoma

        Yang, Y M,Lee, W H,Lee, C G,An, J,Kim, E-S,Kim, S H,Lee, S-K,Lee, C H,Dhanasekaran, D N,Moon, A,Hwang, S,Lee, S J,Park, J-W,Kim, K M,Kim, S G Macmillan Publishers Limited 2015 Oncogene Vol.34 No.22

        Hepatocellular carcinoma (HCC) has a poor prognosis owing to aggressive phenotype. Gα<SUB>12</SUB> gep oncogene product couples to G-protein-coupled receptors, whose ligand levels are frequently increased in tumor microenvironments. Here, we report Gα<SUB>12</SUB> overexpression in human HCC and the resultant induction of zinc-finger E-box-binding homeobox 1 (ZEB1) as mediated by microRNA deregulation. Gα<SUB>12</SUB> expression was higher in HCC than surrounding non-tumorous tissue. Transfection of Huh7 cell with an activated mutant of Gα<SUB>12</SUB> (Gα<SUB>12</SUB>QL) deregulated microRNA (miRNA or miR)-200b/a/429, -194-2/192 and -194-1/215 clusters in the miRNome. cDNA microarray analyses disclosed the targets affected by Gα<SUB>12</SUB> gene knockout. An integrative network of miRNAs and mRNA changes enabled us to predict ZEB1 as a key molecule governed by Gα<SUB>12</SUB>. Decreases of miR-200a/b, -192 and -215 by Gα<SUB>12</SUB> caused ZEB1 induction. The ability of Gα<SUB>12</SUB> to decrease p53 levels, as a result of activating protein-1 (AP-1)/c-Jun-mediated mouse double minute 2 homolog induction, contributed to transcriptional deregulation of the miRNAs. Gα<SUB>12</SUB>QL induced ZEB1 and other epithelial–mesenchymal transition markers with fibroblastoid phenotype change. Consistently, transfection with miR-200b, -192 or -215 mimic prevented the ability of Gα<SUB>12</SUB>QL to increase tumor cell migration/invasion. In xenograft studies, sustained knockdown of Gα<SUB>12</SUB> decreased the overall growth rate and average volume of tumors derived from SK-Hep1 cell (mesenchymal-typed). In HCC patients, miR-192, -215 and/or -200a were deregulated with microvascular invasion or growth advantage. In the HCC samples with higher Gα<SUB>12</SUB> level, a correlation existed in the comparison of relative changes of Gα<SUB>12</SUB> and ZEB1. In conclusion, Gα<SUB>12</SUB> overexpressed in HCC causes ZEB1 induction by deregulating p53-responsive miRNAs, which may facilitate epithelial–mesenchymal transition and growth of liver tumor. These findings highlight the significance of Gα<SUB>12</SUB> upregulation in liver tumor progression, implicating Gα<SUB>12</SUB> as an attractive therapeutic target.

      • KCI우수등재

        N₂/ CH₄가스비에 따른 Hydrogenated Amorphous Carbon Nitride 박막의 특성

        장홍규(H. K. Jang),김근식(G. S. Kim),황보상우(S. W. Whangbo),이연승(Y. S. Lee),황정남(C. N. Whang),유영조(Y. Z. Yoo),김효근(H. G. Kim) 한국진공학회(ASCT) 1998 Applied Science and Convergence Technology Vol.7 No.3

        DC saddle-field-plasma-enhanced chemical-vapor deposition(PECVD) 장치를 이용하여 상온에서 p-type Si (100) 기판위에 hydrogenated amorphous carbon nitride [a-C:H(N)]박막을 증착하였다. 원료가스인 CH₄과 N₂의 전체압력은 90 mTorr로 고정하고 N₂/CH₄비를 0에서 4까지 변화하면서 제작한 a-C:H(N) 박막의 미세 구조의 변화를 연구하였다. 진공조의 도달 진공도는 1×10^(-6) Torr이고, 본 실험시 CH₄+N₂가스의 유량은 5 sc㎝으로 고정하고 배기량을 조절하여 진공조의 가스 압력을 90 mTorr로 고정하였으며 기판에 200 V의 직류 bias 전압을 인가하였다. α-step과 X-ray photoelectron spectroscopy(XPS)를 이용한 분석결과 N₂/CH₄비가 0에서 0.5로 증가함에 따라 박막 두께는 4840 Å에서 2600 Å으로 급격히 감소하였으며, 박막내의 탄소에 대한 질소함유량(N/C비)는 N₂/CH₄비가 4일때 최대 0.25로 증가하는 것을 확인하였다. 또한 XPS 스펙트럼의 fitting 결과 N₂/CH₄비가 증가할수록 CN결합이 증가하였다. Fourier Transformation Infrared (FT-IR) 분석결과 N₂/CH₄비가 증가함에 따라 박막내의 C-H 결합은 감소하고, N-H, C≡N 결합은 증가하였다. Optical bandgap 측정 결 과 N₂/CH₄비가 0에서 4로 증가함에 따라 a-C:H(N)박막의 bandgap 에너지는 2.53 eV에서 2.3 eV로 감소하는 것을 확인하였다. Hydrogenated amorphous carbon nitride[a-C:H(N)] films were deposited on p-type Si(100) at room temperature with substrate bias voltage of 200 V by DC saddle-field plasma-enhanced chemical vapor deposition. Effects of the ratio of N₂to CH₄(N₂/CH₄), in the range of 0 and 4 on such properties as optical properties, microstucture, relative fraction of nitrogen and carbon, etc. of the films have been investigated. The thickness of the a-C:H(N) film was abruptly decreased with the addition of nitrogen, but at N₂/CH₄> 0.5, the thickness of the film gradually decreased with the increase of the N₂/CH₄. The ratio of N to C(N/C) of the films was saturated at 0.25 with the increase of N₂/CH₄. N-H, C≡N bonds of the films increased but C-H bond decreased with the increase of N₂/CH₄. Optical band gap energy of the film decreased from 2.53 eV deposited with pure methane to 2.3 eV at the ratio of N₂/CH₄=4.

      • HCV, Alcoholic : PE-134 ; Hemoglobin decline during peginterferon Alfa-2B (PEG-2B)/ribavirin (RBV) treatment in real-Life is associated with favorable SVR rates in difficult-to-treat patients with HCV genotype 1 (G1) infection

        ( G Teuber ),( S Mauss ),( D Huppe ),( E Zehnter ),( M P Manns ),( T Dahhan6 ),( U Meyer ),( T Witthoft ),( B Moller9,),( N Dikopoulos ),( J Brack ),( B Stade ),( M Bilzer ),( The Bng Hepatitis Study 대한간학회 2012 춘·추계 학술대회 (KASL) Vol.2012 No.-

        Background and Aims: Recently, it has been shown for the overall G1 population that anemia as well as the maximal hemoglobin (Hb) decline during peginterferon/RBV treatment is associated with higher SVR rates. We here investigated whether the maximal Hb decline influences SVR rates in difficult-to-treat patients undergoing Peg2b/RBV therapy for HCV G1 infection in real-life. Methods: Data of patients treated for G1 infection within the German Peg2b/RBV observational study were retrospectively analyzed. In this real-life cohort study G1 infection was treated with Peg2b 1.5 μg/kg/wk + weight-based RBV (800-1200 mg/day) for up to 48 wks at 285 sites. Subjects who discontinued for non-response or for any other reasons were included in the analysis. SVR was defined as undetectable serum HCV-RNA 24 wks after EOT response. Only one patient received erythropoietin treatment for anemia. Results: 1851 patients had baseline and at least one Hb measurement during therapy. Overall SVR rate was 42.6% (789/1851). SVR rates were only slightly higher for subjects with an absolute Hb decline >3 g/dL (44.3%, 493/1114) compared to those with maximum Hb declines <3 g/dL (40.2%, 296/737) (p=0.08). In contrast, a significant (p=0.0004) difference in SVR rates was obtained by comparing subjects with Hb declines >2 g/dL (44.6%, 673/1510) with those who experienced Hb declines <2 g/dL (34.0%, 116/341). Similar SVR rates of 46.1% (164/356) and 44.1% (509/1154) in patients with Hb declines >2 g/dL even if they did/did not become anemic (Hb<10 g/dL) strongly support Hb decline, and not anemia, as primary beneficial mechanism improving SVR. As summarized in the table, Hb declines >2 g/dl were significantly associated with higher SVR rates in difficult-to-treat patients, such as subjects elder than 50 years or subjects with high baseline viral load >600.000 IU/ml. Interestingly no beneficial effect was observed in patients with low platelet count (<150/nL), an indicator of advanced fibrosis/cirrhosis. Patients who first developed a Hb decline >2 g/dL during weeks 0-4 were likely to achieve similar SVR (41.3%, 365/883) than those who developed a Hb decline <2 g/dL (44.9%, 386/859). In contrast, a Hb decline >2 g/dL compared to <2 g/dL during weeks 0-4 was associated with a 2-3 fold higher risk of anemia in female (16.6% vs 40.5%) and male patients (7.3% vs 19.0%) when compared with a Hb decline <2 g/dL. Conclusions: Patients with HCV genotype 1 infection and in particular the subgroup of difficult-to-treat patients elder than 50 years or with HVL, achieve up to 15% higher SVR rates when they develop a Hb decline >2 g/dL during Peg2b/RBV therapy. However, patients with low platelet count <150/nL do not achieve this beneficial virologic effect.

      • HCV : PE-134 ; Hemoglobin decline during peginterferon Alfa-2B (PEG-2B)/ribavirin (RBV) treatment in real-life is associated with favorable SVR rates in difficult-to-treat patients with HCV genotype 1 (G1) infection

        ( G Teuber ),( S Mauss ),( D Huppe ),( E Zehnter ),( M P Manns ),( T Dahhan ),( U Meyer ),( T Witthoft ),( B Moller ),( N Dikopoulos ),( J Brack ),( B Stade ),( M Bilzer ),( Bng Hepatitis Study Group 대한간학회 2012 춘·추계 학술대회 (KASL) Vol.2012 No.1

        Background and Aims: Recently, it has been shown for the overall G1 population that anemia as well as the maximal hemoglobin (Hb) decline during peginterferon/RBV treatment is associated with higher SVR rates. We here investigated whether the maximal Hb decline influences SVR rates in difficult-to-treat patients undergoing Peg2b/RBV therapy for HCV G1 infection in real-life. Methods: Data of patients treated for G1 infection within the German Peg2b/RBV observational study were retrospectively analyzed. In this real-life cohort study G1 infection was treated with Peg2b 1.5 μg/kg/wk + weight-based RBV (800-1200 mg/day) for up to 48 wks at 285 sites. Subjects who discontinued for non-response or for any other reasons were included in the analysis. SVR was defined as undetectable serum HCV-RNA 24 wks after EOT response. Only one patient received erythropoietin treatment for anemia. Results: 1851 patients had baseline and at least one Hb measurement during therapy. Overall SVR rate was 42.6% (789/1851). SVR rates were only slightly higher for subjects with an absolute Hb decline >3 g/dL (44.3%, 493/1114) compared to those with maximum Hb declines <3 g/dL (40.2%, 296/737) (p=0.08). In contrast, a significant (p=0.0004) difference in SVR rates was obtained by comparing subjects with Hb declines >2 g/dL (44.6%, 673/1510) with those who experienced Hb declines <2 g/dL (34.0%, 116/341). Similar SVR rates of 46.1% (164/356) and 44.1% (509/1154) in patients with Hb declines >2 g/dL even if they did/did not become anemic (Hb<10 g/dL) strongly support Hb decline, and not anemia, as primary beneficial mechanism improving SVR. As summarized in the table, Hb declines >2 g/dl were significantly associated with higher SVR rates in difficult-to-treat patients, such as subjects elder than 50 years or subjects with high baseline viral load >600.000 IU/ml. Interestingly no beneficial effect was observed in patients with low platelet count (<150/nL), an indicator of advanced fibrosis/cirrhosis. Patients who first developed a Hb decline >2 g/dL during weeks 0-4 were likely to achieve similar SVR (41.3%, 365/883) than those who developed a Hb decline <2 g/dL (44.9%, 386/859). In contrast, a Hb decline >2 g/dL compared to <2 g/dL during weeks 0-4 was associated with a 2-3 fold higher risk of anemia in female (16.6% vs 40.5%) and male patients (7.3% vs 19.0%) when compared with a Hb decline <2 g/dL. Conclusions: Patients with HCV genotype 1 infection and in particular the subgroup of difficult-to-treat patients elder than 50 years or with HVL, achieve up to 15% higher SVR rates when they develop a Hb decline >2 g/dL during Peg2b/RBV therapy. However, patients with low platelet count <150/nL do not achieve this beneficial virologic effect.

      • Harmonic decomposition of two particle angular correlations in Pb-Pb collisions at s<sub>NN</sub>=2.76 TeV

        ALICE Collaboration,Aamodt, K.,Abelev, B.,Abrahantes Quintana, A.,Adamova, D.,Adare, A.M.,Aggarwal, M.M.,Aglieri Rinella, G.,Agocs, A.G.,Agostinelli, A.,Aguilar Salazar, S.,Ahammed, Z.,Ahmad, N.,Ahmad North-Holland Pub. Co 2012 Physics letters: B Vol.708 No.3

        Angular correlations between unidentified charged trigger (t) and associated (a) particles are measured by the ALICE experiment in Pb-Pb collisions at s<SUB>NN</SUB>=2.76 TeV for transverse momenta 0.25<p<SUB>T</SUB><SUP>t,a</SUP><15 GeV/c, where p<SUB>T</SUB><SUP>t</SUP>>p<SUB>T</SUB><SUP>a</SUP>. The shapes of the pair correlation distributions are studied in a variety of collision centrality classes between 0 and 50% of the total hadronic cross section for particles in the pseudorapidity interval |η|<1.0. Distributions in relative azimuth Δφ=φ<SUP>t</SUP>-φ<SUP>a</SUP> are analyzed for |Δη|=|η<SUP>t</SUP>-η<SUP>a</SUP>|>0.8, and are referred to as ''long-range correlations''. Fourier components V<SUB>nΔ</SUB>≤cos(nΔφ)> are extracted from the long-range azimuthal correlation functions. If particle pairs are correlated to one another through their individual correlation to a common symmetry plane, then the pair anisotropy V<SUB>nΔ</SUB>(p<SUB>T</SUB><SUP>t</SUP>,p<SUB>T</SUB><SUP>a</SUP>) is fully described in terms of single-particle anisotropies v<SUB>n</SUB>(p<SUB>T</SUB>) as V<SUB>nΔ</SUB>(p<SUB>T</SUB><SUP>t</SUP>,p<SUB>T</SUB><SUP>a</SUP>)=v<SUB>n</SUB>(p<SUB>T</SUB><SUP>t</SUP>)v<SUB>n</SUB>(p<SUB>T</SUB><SUP>a</SUP>). This expectation is tested for 1≤n≤5 by applying a global fit of all V<SUB>nΔ</SUB>(p<SUB>T</SUB><SUP>t</SUP>,p<SUB>T</SUB><SUP>a</SUP>) to obtain the best values v<SUB>n</SUB>{GF}(p<SUB>T</SUB>). It is found that for 2≤n≤5, the fit agrees well with data up to p<SUB>T</SUB><SUP>a</SUP>~3-4 GeV/c, with a trend of increasing deviation as p<SUB>T</SUB><SUP>t</SUP> and p<SUB>T</SUB><SUP>a</SUP> are increased or as collisions become more peripheral. This suggests that no pair correlation harmonic can be described over the full 0.25<p<SUB>T</SUB><15 GeV/c range using a single v<SUB>n</SUB>(p<SUB>T</SUB>) curve; such a description is however approximately possible for 2≤n≤5 when p<SUB>T</SUB><SUP>a</SUP><4 GeV/c. For the n=1 harmonic, however, a single v<SUB>1</SUB>(p<SUB>T</SUB>) curve is not obtained even within the reduced range p<SUB>T</SUB><SUP>a</SUP><4 GeV/c.

      • KCI등재

        Effect of controlled O<sub>2</sub> impurities on N<sub>2</sub> afterglows of RF discharges

        Kang, N.,Lee, M.,Ricard, A.,Oh, S.g. Elsevier 2012 Current Applied Physics Vol.12 No.6

        A RF capacitive flowing discharge and post-discharge are experimentally studied in N<SUB>2</SUB> gas and N<SUB>2</SUB>-(10<SUP>-4</SUP>-10<SUP>-2</SUP>)O<SUB>2</SUB> gas mixtures by using the optical emission spectroscopy at a pressure of 8 Torr, a flow rate of 1 slm and a transmitted RF power of 100 W. In these conditions the flowing discharge is distinguished by early and late afterglow. It is shown that the early afterglow is very sensitive to small quantity of O<SUB>2</SUB>. The band emissions from N<SUB>2</SUB><SUP>+</SUP>(B) and N<SUB>2</SUB>(B,υ') decreased sharply in the early afterglow when O<SUB>2</SUB> is introduced before the plasma. By using simple gas kinetics for pseudo-stationary conditions in the afterglows, N<SUB>2</SUB><SUP>+</SUP>+O<SUB>2</SUB> charge transfer and N<SUB>2</SUB>(a') quenching by O<SUB>2</SUB> play key roles in the afterglow. The charge transfers and quenching reactions are amplified when O-atoms are produced in the plasma. It is also observed that the O-atoms are produced in the early afterglow when O<SUB>2</SUB> is introduced after the plasma.

      • SCIESCOPUSKCI등재

        Restriction of Metabolizable Energy in Broiler Growers and Its Impact on Grower and Breeder Performance

        Sunder, G. Skyam,Kumar, Ch. Vijaya,Panda, A.K.,Raju, M.V.L.N.,Rao, S.V. Rama,Gopinath, N.C.S.,Reddy, M.R. Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.8

        Metabolizable energy (ME) required for basal metabolism, activity and growth was considered as the criterion for targeting specific increases in body weight (100 g/week) of broiler chicks during the grower phase (5-20 weeks) and its impact was evaluated on breeder performance. Broiler female chicks (460) from a synthetic dam line were randomly distributed to 4 test groups with 23 replicates of 5 birds each and housed in cages. The first group (ME-100) was offered a calculated amount of ME by providing a measured quantity of grower diet (160 g protein and 2,600 kcal ME/kg) which increased with age and weight gain (133-294 kcal/bird/day). The other three groups were offered 10 or 20% less ME (ME-90 and ME-80, respectively) and 10% excess ME (ME-110) over the control group (ME-100). From 21 weeks of age, a single breeder diet (170 g protein and 2,600 kcal ME/kg) was uniformly fed to all groups and the impact of grower ME restriction on breeder performance evaluated up to 58 weeks. The targeted body weight gain of 1,600 g in a 16-week period was achieved by pullets of the ME-100 group almost one week earlier by gaining 8.7 g more weight per week. However, pullets in the ME-90 group gained 1,571 g during the same period, which was closer to the targeted weight. At 20 weeks of age, the conversion efficiency of feed (5.21-5.37), ME (13.9-14.1 kcal/g weight gain) and protein (0.847-0.871 g/g weight gain), eviscerated meat yield, giblet and tibia weights were not influenced by ME restriction, but the weights of abdominal fat and liver were higher with increased ME intake. Reduction of ME by 10% in the grower period significantly delayed sexual maturity (169.3 d), but increased egg production (152.5 /bird) with better persistency. Improved conversion efficiency of feed, ME and protein per g egg content were also observed in this group up to 56 weeks. The fertility and hatchability at 58 weeks of age were higher in the ME-90 group compared to the control and 10% excess ME feeding. In conclusion, the present study revealed the possibility of achieving targeted weight gain in broiler growers by feeding measured quantities of ME during the rearing period with consequential benefits in breeder performance.

      • SCISCIESCOPUS

        Direct analysis of site-specific N-glycopeptides of serological proteins in dried blood spot samples

        Choi, N. Y.,Hwang, H.,Ji, E. S.,Park, G. W.,Lee, J. Y.,Lee, H. K.,Kim, J. Y.,Yoo, J. S. Springer Science + Business Media 2017 Analytical and Bioanalytical Chemistry Vol.409 No.21

        <P>Dried blood spot (DBS) samples have a number of advantages, especially with respect to ease of collection, transportation, and storage and to reduce biohazard risk. N-glycosylation is a major post-translational modification of proteins in human blood that is related to a variety of biological functions, including metastasis, cell-cell interactions, inflammation, and immunization. Here, we directly analyzed tryptic N-glycopeptides from glycoproteins in DBS samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS) without centrifugation of blood samples, depletion of major proteins, desalting of tryptic peptides, and enrichment of N-glycopeptides. Using this simple method, we identified a total of 41 site-specific N-glycopeptides from 16 glycoproteins in the DBS samples, from immunoglobulin gamma 1 (IgG-1, 10 mg/mL) down to complement component C7 (50 mu g/mL). Of these, 32 N-glycopeptides from 14 glycoproteins were consistently quantified over 180 days stored at room temperature. The major abundant glycoproteins in the DBS samples were IgG-1 and IgG-2, which contain nine asialo-fucosylated complex types of 16 different N-glycopeptide isoforms. Sialo-non-fucosylated complex types were primarily detected in the other glycoproteins such as alpha-1-acid glycoprotein 1, 2, alpha-1-antitypsin, alpha-2-macroglobulin, haptoglobin, hemopexin, Ig alpha 1, 2 chain C region, kininogen-1, prothrombin, and serotransferrin. We first report the characterization of site-specific N-glycoproteins in DBS samples by LC-MS/MS with minimal sample preparation.</P>

      • SCISCIESCOPUS

        Stepwise selective reaction of two N-cyanoethyl groups attached to C-racemic tetraaza macrocyclic nickel(II) and copper(II) complexes in aqueous solutions

        Kang, S.G.,Kim, N.,Jeong, J.H. Elsevier Sequoia [etc.] 2011 Inorganica chimica acta Vol.366 No.1

        Stepwise hydrolysis of two N-(CH<SUB>2</SUB>)<SUB>2</SUB>CN groups attached to [Ni(C-racemic-L<SUP>2</SUP>)(OAc)]<SUP>+</SUP> and [Cu(C-racemic-L<SUP>2</SUP>)]<SUP>2+</SUP> (L<SUP>2</SUP>=1,8-bis(N-cyanoethyl)-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) has been investigated. The reaction of [Ni(C-meso-L<SUP>2</SUP>)]<SUP>2+</SUP> has also been examined. Interestingly, [Ni(C-racemic-L<SUP>2</SUP>)(OAc)]<SUP>+</SUP> is readily hydrolyzed to [Ni(C-racemic-L<SUP>3</SUP>)]<SUP>2+</SUP> bearing one N-(CH<SUB>2</SUB>)<SUB>2</SUB>CONH<SUB>2</SUB> and one N-(CH<SUB>2</SUB>)<SUB>2</SUB>CN pendant arms at pH @?6, whereas [Cu(C-racemic-L<SUP>2</SUP>)]<SUP>2+</SUP> and [Ni(C-meso-L<SUP>2</SUP>)]<SUP>2+</SUP> are quite inert against hydrolysis under similar acidic conditions. Although [Cu(C-racemic-L<SUP>2</SUP>)]<SUP>2+</SUP> is hydrolyzed to [Cu(C-racemic-L<SUP>3</SUP>)]<SUP>2+</SUP> at pH 9, [Ni(C-meso-L<SUP>2</SUP>)]<SUP>2+</SUP> readily undergoes C-N bond cleavage to yield [Ni(C-meso-L<SUP>1</SUP>)]<SUP>2+</SUP> (L<SUP>1</SUP>=5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) in basic aqueous solutions. The hetero-functionalized complex [Ni(C-racemic-L<SUP>3</SUP>)]<SUP>2+</SUP> undergoes hydrolysis and C-N bond cleavage at pH 9 and 13, respectively; both [Ni(C-racemic-L<SUP>4</SUP>)]<SUP>2+</SUP> bearing two N-(CH<SUB>2</SUB>)<SUB>2</SUB>CONH<SUB>2</SUB> pendant arms and [Ni(C-racemic-L<SUP>5</SUP>)]<SUP>2+</SUP> bearing one N-(CH<SUB>2</SUB>)<SUB>2</SUB>CONH<SUB>2</SUB> group can be prepared selectively by controlling pH of the solution. However, [Cu(C-racemic-L<SUP>3</SUP>)]<SUP>2+</SUP> readily undergoes C-N bond cleavage to produce [Cu(C-racemic-L<SUP>5</SUP>)]<SUP>2+</SUP> even at pH 9. Crystal structure of [Ni(C-racemic-L<SUP>3</SUP>)]<SUP>2+</SUP> shows that the complex has severely distorted trigonal bipyramidal coordination geometry. Electronic absorption spectra of [Cu(C-racemic-L<SUP>3</SUP>)]<SUP>2+</SUP>, [Ni(C-racemic-L<SUP>5</SUP>)]<SUP>2+</SUP>, and [Cu(C-racemic-L<SUP>5</SUP>)]<SUP>2+</SUP> indicate that they also have trigonal bipyramidal coordination geometry.

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