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Park, J. H., R. M. Iqbal, A. A. M. El-Aty, T. W. Na, J. H. Choi, M. W. Ghafar, W. J. Choi, K.S.Kim, S. D. Kim, and J. H. Shim, "Simultaneous multiresidue determination of 48 pesticides in Yeongsan and Sumjin River water using GC-NPD and confirmation via GC-MS", Biomedical Chromatography, vol. 25, pp. 155-163, 2011.
Park, W. S., N. Kim, J. B. Youm, M. Warda, J. - H. Ko, S. J. Kim, Y. E. Earm, and J. Han, "Angiotensin II inhibits inward rectifier K+ channels in rabbit coronary arterial smooth muscle cells through protein kinase Calpha.", Biochemical and biophysical research communications, vol. 341, issue 3, pp. 728-35, 2006 Mar 17. Abstract

We investigated the effects of the vasoconstrictor angiotensin (Ang) II on the whole cell inward rectifier K(+) (Kir) current enzymatically isolated from small-diameter (<100 microm) coronary arterial smooth muscle cells (CASMCs). Ang II inhibited the Kir current in a dose-dependent manner (half inhibition value: 154 nM). Pretreatment with phospholipase C inhibitor and protein kinase C (PKC) inhibitors prevented the Ang II-induced inhibition of the Kir current. The PKC activator reduced the Kir currents. The inhibitory effect of Ang II was reduced by intracellular and extracellular Ca(2+) free condition and by Gö6976, which inhibits Ca(2+)-dependent PKC isoforms alpha and beta. However, the inhibitory effect of Ang II was unaffected by a peptide that selectively inhibits the translocation of the epsilon isoform of PKC. Western blot analysis confirmed that PKCalpha, and not PKCbeta, was expressed in small-diameter CASMCs. The Ang II type 1 (AT(1))-receptor antagonist CV-11974 prevented the Ang II-induced inhibition of the Kir current. From these results, we conclude that Ang II inhibits Kir channels through AT(1) receptors by the activation of PKCalpha.

Park, L. P., V. H. Chu, Gail Peterson, Athanasios Skoutelis, T. Lejko-Zupa, E. Bouza, P. Tattevin, G. Habib, R. Tan, J. Gonzalez, et al., "Validated Risk Score for Predicting 6-Month Mortality in Infective Endocarditis", Journal of the American Heart Association, vol. 5, no. 4: American Heart Association, Inc., pp. e003016, 2016. Abstract
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Park, W. S., Y. K. Son, N. Kim, J. - H. Ko, S. H. Kang, M. Warda, Y. E. Earm, I. D. Jung, Y. - M. Park, and J. Han, "Acute hypoxia induces vasodilation and increases coronary blood flow by activating inward rectifier K(+) channels.", Pflugers Archiv : European journal of physiology, vol. 454, issue 6, pp. 1023-30, 2007 Sep. Abstract

We examined the effects of acute hypoxia on vascular tone and coronary blood flow (CBF) in rabbit coronary arteries. In the pressurized arterial preparation of small arteries (<100 mum) and the Langendorff-perfused rabbit hearts, hypoxia induced coronary vasodilation and increased CBF in the presence of glibenclamide (K(ATP) channel blocker), Rp-8-Br-PET-cGMPs [cyclic guanosine monophosphate (cGMP)-dependent protein kinase inhibitor, Rp-cGMPs], and methionyl transfer RNA synthetase (MRS) 1334 (adenosine A(3) receptor inhibitor); these increases were inhibited by the inward rectifier K(+) (Kir) channel inhibitor, Ba(2+). These effects were blocked by the adenylyl cyclase inhibitor SQ 22536 and by the cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) inhibitors Rp-8-CPT-cAMPs (Rp-cAMPs) and KT 5720. However, cGMP-dependent protein kinase was not involved in the hypoxia-induced increases of the vascular diameter and CBF. In summary, our results suggest that acute hypoxia can induce the opening of Kir channels in coronary artery that has small diameter (<100 mum) by activating the cAMP and PKA signalling pathway, which could contribute to vasodilation and, therefore, increased CBF.

Park, W. S., J. - H. Ko, N. Kim, Y. K. Son, S. H. Kang, M. Warda, I. D. Jung, Y. - M. Park, and J. Han, "Increased inhibition of inward rectifier K+ channels by angiotensin II in small-diameter coronary artery of isoproterenol-induced hypertrophied model.", Arteriosclerosis, thrombosis, and vascular biology, vol. 27, issue 8, pp. 1768-75, 2007 Aug. Abstract

OBJECTIVE: We investigated the effects of angiotensin II (Ang II) on inward rectifier K+ (Kir) channels in small-diameter coronary arterial smooth muscle cells (SCASMCs) of control and isoproterenol (Iso)-induced hypertrophied rabbits.

METHODS AND RESULTS: Kir current amplitude and Kir channel protein expression were definitely lower in the Iso-induced hypertrophied model than in the control. In a pressurized arterial experiment, 15 mmol/L K+-induced vasodilation was greater in the control arteries than in the arteries of Iso-induced hypertrophied model. Ang II reduced the Kir current in a concentration-dependent manner, and this inhibition was greater in SCASMCs from Iso-induced hypertrophied model than from control. Although, there was no difference in the expression of Ang II type 2 (AT2) receptor between SCASMCs of control and Iso-induced hypertrophied model, the expression of Ang II type 1 (AT1) receptor and phosphorylated PKC alpha were greater in SCASMCs of Iso-induced hypertrophied model than of control.

CONCLUSION: Ang II inhibits Kir channels more prominently in SCASMCs of Iso-induced hypertrophied model owing to increases in the expression of AT1 receptor and the activation of PKC alpha. Our findings about the differential expression of Kir channels and different modulation of Kir channels by a vasoconstrictor (Ang II) in a hypertrophy model are important for better understanding the responsiveness of small-diameter arteries during hypertrophy.

Park, K., J. Huber, M. G. Kolta, F. K. R. Stino, S. S. Samaan, and K. F. A. Soliman, "Behavioral Responses to Repeated Cocaine Exposure in Mice Selectively Bred for Differential Sensitivity to Pentobarbital", Annals of the New York Academy of Sciences, vol. 914, issue 1: Blackwell Publishing Ltd, pp. 323-335, 2000. Abstract
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Park, J. - H., N. Bakheet, H. K. Na, J. Y. Jeon, S. H. Yoon, K. Y. Kim, W. Zhe, D. H. Kim, H. - Y. Jung, and H. - Y. Song, "A Novel Full Sense Device to Treat Obesity in a Porcine Model: Preliminary Results.", Obesity surgery, vol. 29, issue 5, pp. 1521-1527, 2019. Abstract

PURPOSE: To evaluate the technical feasibility, safety, and efficacy of a novel full sense device (FSD) for the treatment of obesity in a porcine model.

MATERIALS AND METHODS: The novel FSD comprised a self-expanding metallic esophageal stent connected to a star-shaped nitinol disk. Three types of FSD were used: fully covered (type A), fully covered with barbs (type B), and uncovered with barbs (type C). Nine juvenile pigs were divided into two groups: FSD (n = 6) and control (n = 3). FSD type A was placed in the FSD group. In case of migration, either FSD type B or type C was then randomly placed. Food intake was monitored daily. Weight changes and ghrelin hormone levels were monitored weekly for 12 weeks.

RESULTS: FSD placement was technically successful in all pigs. All FSDs except one migrated to the stomach within 1 week after placement. The pig in which the FSD was retained showed decreased food intake in the first week after FSD placement, and there was a difference in the final weight between the FSD pig and control pigs. The percentage of weight gain was 116.6% in the control group and 105.3% in the FSD pig.

CONCLUSION: FSD placement under fluoroscopic and endoscopic guidance is technically feasible and safe in a porcine model. The uncovered FSD appears to decrease food intake and reduce the rate of weight gain. However, the high FSD migration rate is not encouraging.

Park, J. H., M. I. R. Mamun, A. A. M. El-Aty, T. W. Na, J. - H. Choi, M. W. Ghafar, W. J. Choi, K. S. Kim, S. D. Kim, and J. - H. Shim, "Simultaneous Multiresidue Determination Of 48 Pesticides in Yeongsan and Sumjin River water using GC-NPD and Confirmation via GC-MS", Biomedical Chromatography, 2011. Abstract

In a continuation of our earlier work, a multiresidual analytical method using 48 frequently used neutral pesticides in a water matrix was developed and validated in this study. The samples were extracted with dichloromethane and the pesticides were analyzed via GC-NPD followed by confirmation with GC-MS. Good linearity was detected over a concentration range of 0.01-1.0 microg/mL with correlation coefficients (r(2) ) in excess of 0.982. The recoveries were measured between 70.7 and 111.4% for the majority of the targeted pesticides with relative standard deviations (RSDs) of less than 20%. The LODs and LOQs were in ranges of 0.1-2 and 0.33-6.6 microg/L, respectively. A total of 66 water samples were collected from different locations in Yeongsan and the Sumjin River, Republic of Korea, and were analyzed in accordance with the developed method. None of the water samples were determined to contain any of the targeted pesticides. The method has been shown to be simpler, faster, and more cost-effective than the method established by the Environmental Protection Agency (EPA).

Park, J. H., R. M. Iqbal, A. A. M. El-Aty, T. W. Na, C. JH, M. W. Ghafar, K. S. Kim, S. D. Kim, and J. H. Shim, "Development and validation of a multiresidue method for determination of 37 pesticides in soil using GC-NPD", Biomedical Chromatography, vol. 25, pp. 1003-1009, 2011. development_and_validation_of_a_multiresidue.pdf
Park, W. S., Y. K. Son, N. Kim, J. B. Youm, H. Joo, M. Warda, J. - H. Ko, Y. E. Earm, and J. Han, "The protein kinase A inhibitor, H-89, directly inhibits KATP and Kir channels in rabbit coronary arterial smooth muscle cells.", Biochemical and biophysical research communications, vol. 340, issue 4, pp. 1104-10, 2006 Feb 24. Abstract

The effects of the protein kinase A (PKA) inhibitor H-89 on ATP-sensitive K+ (KATP) and inward rectifier K+ (Kir) currents were examined in rabbit coronary arterial smooth muscle cells using the patch clamp technique. The H-89, in a dose-dependent manner, inhibited KATP and Kir currents with apparent Kd values of 1.19+/-0.18 and 3.78+/-0.37 microM, respectively. H-85, which is considered as an inactive form of H-89, inhibited KATP and Kir currents, similar to the result of H-89. KATP and Kir currents were not affected by either Rp-8-CPT-cAMPs, which is a membrane-permeable selective PKA inhibitor, or KT 5720, which is also known as a PKA inhibitor. Also, these two drugs did not significantly alter the effects of H-89 on the KATP and Kir currents. These results suggest that H-89 directly inhibits the KATP and Kir currents of rabbit coronary arterial smooth muscle cells independently of PKA inhibition.

Park, W. S., Y. K. Son, N. Kim, J. B. Youm, M. Warda, J. - H. Ko, E. A. Ko, S. H. Kang, E. Kim, Y. E. Earm, et al., "Direct modulation of Ca(2+)-activated K(+) current by H-89 in rabbit coronary arterial smooth muscle cells.", Vascular pharmacology, vol. 46, issue 2, pp. 105-13, 2007 Feb. Abstract

The effects of H-89, a potent and selective inhibitor of protein kinase A (PKA) on Ca(2+)-activated K(+) (BK(Ca)) channels in coronary arterial smooth muscle cells were examined using a patch-clamp technique. In inside-out configuration, H-89 increased the NP(o) of the BK(Ca) channel, but it reduced the dwell time of BK(Ca) currents. In whole-cell configuration, H-89 markedly increased BK(Ca) currents in a concentration-dependent manner. The EC(50) was 0.470+/-0.0741 microM based on dwell time, 0.582+/-0.0691 microM based on the NP(o), and 0.519+/-0.0295 microM based on the whole-cell current, respectively. H-85, which is an inactive form of H-89, increased BK(Ca) currents, similar to the result of H-89. The other PKA inhibitors (Rp-8-CPT-cAMPs and KT 5720) and protein phosphatase inhibitor (okadaic acid, 1 microM) had little effect on BK(Ca) currents and did not significantly alter the stimulatory effects of 1 microM H-89. These findings suggest that H-89 increases the BK(Ca) current independently of PKA.

Park, W. S., Y. K. Son, N. Kim, J. - H. Ko, S. H. Kang, M. Warda, Y. E. Earm, I. D. Jung, Y. - M. Park, and J. Han, "Acute hypoxia induces vasodilation and increases coronary blood flow by activating inward rectifier K(+) channels.", Pflügers Archiv : European journal of physiology, vol. 454, issue 6, pp. 1023-30, 2007 Sep. Abstract

We examined the effects of acute hypoxia on vascular tone and coronary blood flow (CBF) in rabbit coronary arteries. In the pressurized arterial preparation of small arteries (<100 mum) and the Langendorff-perfused rabbit hearts, hypoxia induced coronary vasodilation and increased CBF in the presence of glibenclamide (K(ATP) channel blocker), Rp-8-Br-PET-cGMPs [cyclic guanosine monophosphate (cGMP)-dependent protein kinase inhibitor, Rp-cGMPs], and methionyl transfer RNA synthetase (MRS) 1334 (adenosine A(3) receptor inhibitor); these increases were inhibited by the inward rectifier K(+) (Kir) channel inhibitor, Ba(2+). These effects were blocked by the adenylyl cyclase inhibitor SQ 22536 and by the cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) inhibitors Rp-8-CPT-cAMPs (Rp-cAMPs) and KT 5720. However, cGMP-dependent protein kinase was not involved in the hypoxia-induced increases of the vascular diameter and CBF. In summary, our results suggest that acute hypoxia can induce the opening of Kir channels in coronary artery that has small diameter (<100 mum) by activating the cAMP and PKA signalling pathway, which could contribute to vasodilation and, therefore, increased CBF.

Park, K., M. Coffee, K. F. A. Soliman, M. G. Kolta, and F. K. R. Stino, "Amphetamine sensitization in mice selected for differential response to pentobarbital sedation times.", FASEB JOURNAL, vol. 12, issue 4: FEDERATION AMER SOC EXP BIOL 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA, pp. A160-A160, 1998. Abstract
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Park, J. - Y., J. - H. Choi, A. A. M. El-Aty, B. M. Kim, J. - H. Park, W. J. Choi, and J. - H. Shim, "Development and Validation of an Analytical Method for Determination of Endocrine Disruptor, 2,4-D, In Paddy Field Water", Biomedical Chromatography, vol. 25, issue 9, pp. 1018–1024, 2011. Abstract

The acidic herbicides are an important class of chemical compounds that are used to control a variety of weeds that threaten many crops. Owing to their low microbial activity levels, the acidic herbicides exhibit a residual activity remaining for periods of up to several months in soils and water. The principal objective of this study was to develop an analytical method based on liquid–liquid and solid-phase extraction followed by HPLC, for the determination of 2,4-D in paddy field water. The residues were verified via tandem mass spectrometry (MS/MS) in negative-ion electrospray ionization (ESI) mode. Linearity was good over a concentration range of 1–100 µg/L with a correlation coefficient (r2) of 0.999. The mean recovery rates of triplicate results ranged from 85.2 to 90.85%. The limits of detection and quantitation were 0.4 and 1.0 µg/L, respectively. The method proposed herein was applied to field samples acquired from Hampyung and Sunchang counties, Republic of Korea. The analyte was detected at a concentration range of 6.8–12.8 and 3.55–24.0 µg/L, respectively.

Park, C., R. I. Nuruddeen, K. K. Ali, L. Muhammad, M. S. Osman, and D. Baleanu, "Novel hyperbolic and exponential ansatz methods to the fractional fifth-order Korteweg–de Vries equations", Advances in Difference Equations, vol. 2020, pp. 627, 2020.
Park, L. P., V. H. Chu, Gail Peterson, Athanasios Skoutelis, T. Lejko-Zupa, E. Bouza, P. Tattevin, G. Habib, R. Tan, J. Gonzalez, et al., "Validated Risk Score for Predicting 6-Month Mortality in Infective Endocarditis", Journal of the American Heart Association, vol. 5, no. 4: American Heart Association, Inc., pp. e003016, 2016. Abstract
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Park, J. Y., J. H. Choi, B. M. Kim, J. H. Park, S. K. Cho, M. W. Ghafar, A. A. M. El-Aty, and J. H. Shim, "Determination of acetamiprid residues in zucchini grown under greenhouse conditions: application to behavioral dynamics", Biomedical Chromatography, vol. 25, pp. 136-146, 2011.
Park, S. I., J. - H. Park, A. - Y. Ko, A. M. Abd El-Aty, A. Goudah, J. Jang, M. M. Rahman, M. R. Kim, and J. - H. Shim, "Optimization of supercritical fluid extraction method for detection of fluquinconazole and tetraconazole in soil using gas chromatography and confirmation using GC-MS: application to dissipation kinetics", Biomedical Chromatography, vol. 28, no. 6, pp. 774–781, 2014. AbstractWebsite
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Park, W. S., Y. K. Son, N. Kim, J. B. Youm, M. Warda, J. - H. Ko, E. A. Ko, S. H. Kang, E. Kim, Y. E. Earm, et al., "Direct modulation of Ca(2+)-activated K(+) current by H-89 in rabbit coronary arterial smooth muscle cells.", Vascular pharmacology, vol. 46, issue 2, pp. 105-13, 2007 Feb. Abstract

The effects of H-89, a potent and selective inhibitor of protein kinase A (PKA) on Ca(2+)-activated K(+) (BK(Ca)) channels in coronary arterial smooth muscle cells were examined using a patch-clamp technique. In inside-out configuration, H-89 increased the NP(o) of the BK(Ca) channel, but it reduced the dwell time of BK(Ca) currents. In whole-cell configuration, H-89 markedly increased BK(Ca) currents in a concentration-dependent manner. The EC(50) was 0.470+/-0.0741 microM based on dwell time, 0.582+/-0.0691 microM based on the NP(o), and 0.519+/-0.0295 microM based on the whole-cell current, respectively. H-85, which is an inactive form of H-89, increased BK(Ca) currents, similar to the result of H-89. The other PKA inhibitors (Rp-8-CPT-cAMPs and KT 5720) and protein phosphatase inhibitor (okadaic acid, 1 microM) had little effect on BK(Ca) currents and did not significantly alter the stimulatory effects of 1 microM H-89. These findings suggest that H-89 increases the BK(Ca) current independently of PKA.

Park, J. - G., F. S. Oladunni, M. A. Rohaim, J. Whittingham-Dowd, J. Tollitt, M. D. J. Hodges, N. Fathallah, M. B. Assas, W. Alhazmi, A. Almilaibary, et al., "Immunogenicity and protective efficacy of an intranasal live-attenuated vaccine against SARS-CoV-2.", iScience, vol. 24, issue 9, pp. 102941, 2021. Abstract

Global deployment of an effective and safe vaccine is necessary to curtail the coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here, we evaluated a Newcastle disease virus (NDV)-based vectored-vaccine in mice and hamsters for its immunogenicity, safety, and protective efficacy against SARS-CoV-2. Intranasal administration of recombinant (r)NDV-S vaccine expressing spike (S) protein of SARS-CoV-2 to mice induced high levels of SARS-CoV-2-specific neutralizing immunoglobulin A (IgA) and IgG2a antibodies and T-cell-mediated immunity. Hamsters immunized with two doses of vaccine showed complete protection from lung infection, inflammation, and pathological lesions following SARS-CoV-2 challenge. Importantly, administration of two doses of intranasal rNDV-S vaccine significantly reduced the SARS-CoV-2 shedding in nasal turbinate and lungs in hamsters. Collectively, intranasal vaccination has the potential to control infection at the site of inoculation, which should prevent both clinical disease and virus transmission to halt the spread of the COVID-19 pandemic.

Park, W. S., J. - H. Ko, N. Kim, Y. K. Son, S. H. Kang, M. Warda, I. D. Jung, Y. - M. Park, and J. Han, "Increased inhibition of inward rectifier K+ channels by angiotensin II in small-diameter coronary artery of isoproterenol-induced hypertrophied model.", Arteriosclerosis, thrombosis, and vascular biology, vol. 27, issue 8, pp. 1768-75, 2007 Aug. Abstract

OBJECTIVE: We investigated the effects of angiotensin II (Ang II) on inward rectifier K+ (Kir) channels in small-diameter coronary arterial smooth muscle cells (SCASMCs) of control and isoproterenol (Iso)-induced hypertrophied rabbits.

METHODS AND RESULTS: Kir current amplitude and Kir channel protein expression were definitely lower in the Iso-induced hypertrophied model than in the control. In a pressurized arterial experiment, 15 mmol/L K+-induced vasodilation was greater in the control arteries than in the arteries of Iso-induced hypertrophied model. Ang II reduced the Kir current in a concentration-dependent manner, and this inhibition was greater in SCASMCs from Iso-induced hypertrophied model than from control. Although, there was no difference in the expression of Ang II type 2 (AT2) receptor between SCASMCs of control and Iso-induced hypertrophied model, the expression of Ang II type 1 (AT1) receptor and phosphorylated PKC alpha were greater in SCASMCs of Iso-induced hypertrophied model than of control.

CONCLUSION: Ang II inhibits Kir channels more prominently in SCASMCs of Iso-induced hypertrophied model owing to increases in the expression of AT1 receptor and the activation of PKC alpha. Our findings about the differential expression of Kir channels and different modulation of Kir channels by a vasoconstrictor (Ang II) in a hypertrophy model are important for better understanding the responsiveness of small-diameter arteries during hypertrophy.

Park, A. R., S. - I. Jeong, H. W. Jeon, J. Kim, N. Kim, M. T. Ha, M. Mannaa, J. Kim, C. W. Lee, and B. S. MIN, "A Diketopiperazine, Cyclo-(L-Pro-L-Ile), Derived From Bacillus thuringiensis JCK-1233 Controls Pine Wilt Disease by Elicitation of Moderate Hypersensitive Reaction", Frontiers in plant science, vol. 11: Frontiers, pp. 1023, 2020. Abstract
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Park S, Park CS, L. S. J. C. C. Y. A. S. Y. E. A. K. G. S. J. J. S. A. E. - A. A. M. E. - B. H. A. B. Y., "Development and validation of a high-performance liquid chromatography-tandem mass spectrometric method for simultaneous determination of bupropion, quetiapine and escitalopram in human plasma.", Biomedical chromatography, vol. 7, issue 4, pp. 369-384, 2013. Abstract

In the present study, an effective high performance liquid chromatography-tandem mass spectrometric (HPLC/MS/MS) method was developed and validated to simultaneously determine bupropion (BUP), quetiapine (QUE) and escitalopram (ESC) in human plasma using carbidopa as the internal standard. Chromatographic separation was achieved on a Waters Sun Fire C18 column using reversed-phase chromatography. The MS/MS experiment was performed in positive ion multiple reaction monitoring mode to produce product ions of m/z 240.3 → 184.2 for BUP, 384.2 → 253.1 for QUE, 325.3 → 109.3 for ESC and 227.2 → 181.2 for the internal standard. The method showed good linearity (R(2)  ≥ 0.997), precision (relative standard deviation ≤7.5%), satisfactory intra- and interday accuracy (88.4-113.0%) and acceptable extraction recovery (87.2-115.0%), matrix effect (84.5.5-108.7%) and stability (92.3-103.5%). The method was successfully applied to determine the concentrations of BUP, QUE and ESC in human plasma samples. Copyright © 2014 John Wiley & Sons, Ltd.

Parkanyi, C., Abdou O. Abdelhamid, J. C. S. Cheng, and A. S. Shawali., "Convenient Synthesis of Fused Heterocycles from -Ketohydroximoyl Chlorides and Heterocyclic Amines", J. Heterocycl. Chem., vol. 21, pp. 21, 1984.
Parkanyi, C., A. O. Abdelhamid, and A. S. Shawali., "Convenient Synthesis of Arylazo Derivatives of Quinoxaline, 1,4-Benzothiazine, and 1,4-Benzoxazine", J. Heterocycl. Chem., vol. 21, pp. 521 , 1984.