The Experts below are selected from a list of 135 Experts worldwide ranked by ideXlab platform
Stephan Held - One of the best experts on this subject based on the ideXlab platform.
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Merbromin mercurochrome and other xanthene dyes quantum yields of triplet sensitizer generation and singlet oxygen formation in alcoholic solutions
Journal of Photochemistry and Photobiology B-biology, 1992Co-Authors: Klaus Gollnick, Theodor Franken, Mohamed F R Fouda, Hanns R Paur, Stephan HeldAbstract:Abstract Absorption, fluorescence and phosphorescence maxima, singlet and triplet energies, and quantum yields of fluorescence φ F and intersystem crossing φ T of highly purified disodium salts of fluorescein dyes in alcoholic solutions are reported. The method of φ T determination by “external heavy atom enhanced photo-oxygenation” is described. Oxygen exerts no measurable effect on the short-lived excited singlet states but quenches the triplet states quantitatively in O 2 -saturated solutions, mainly by energy transfer yielding singlet oxygen, 1 O 2 ( 1 Δ g ). By increasing the number and atomic weight of halogen substituents in the fluorescein molecule, the quantum yields of triplet formation φ T and 1 O 2 generation φ Δ are enhanced, whereas the efficiency S Δ , with which interactions of the triplet excited dye with 3 O 2 yield singlet oxygen, seems to decrease. Within experimental error, φ F +φ T is equal to unity for the xanthene dianions. For the cationic sensitizer rhodamine B, however, this sum equals about 0.7, indicating that deactivation of the singlet excited state by internal conversion plays an appreciable role. Merbromin, a HgOH-substituted dibromofluorescein used world-wide as an inexpensive antiseptic (mercuchrome TM , mercurochrome TM ), shows quantum yields of 0.16±0.04 for triplet formation and 0.14±0.02 for 1 O 2 generation in alcoholic solution. Why mercury does not exhibit the expected internal heavy atom effect on the intersystem crossing process, remains to be elucidated.
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Merbromin mercurochrome a photosensitizer for singlet oxygen reactions
Journal of Photochemistry and Photobiology B-biology, 1990Co-Authors: Klaus Gollnick, Stephan HeldAbstract:Abstract Merbromin, produced in many countries and used world wide as an antiseptic under the trademark “mercurochrome”, is shown to be an efficient sensitizer for type II (singlet oxygen) photo-oxygenations by using 2-methyl-2-butene, (+)-limonene, (+)-α-pinene, α,α′-dimethylstilbenes and (—)- l -methionine as oxygen acceptors. Type I photo-oxygenations are negligible. An estimate of the quantum yield of singlet oxygen formation by Merbromin in methanol gives a value of about 0.1.
Zhongcheng Wang - One of the best experts on this subject based on the ideXlab platform.
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a new chemiluminescence method for determination of dicyandiamide based on the n bromosuccinimide Merbromin cetyltrimethylammonium bromide system
Journal of Luminescence, 2015Co-Authors: Hua Yu, Yuhai Tang, Guangbin Zhang, Zhongcheng WangAbstract:Abstract A novel and highly sensitive chemiluminescence (CL) method for the determination of dicyandiamide (DCD) has been developed based on the new CL system of N-bromosuccinimide–Merbromin–cetyltrimethylammonium bromide in alkaline solution. Experiment conditions were optimized using central composite design-response surface methodology. Under the optimal conditions, the relative CL intensity was linear with the concentration of DCD ranging from 5.0×10−8 g mL−1 to 3.0×10−6 g mL−1. The detection limit, at the signal-to-noise ratio of 3, was 3.0×10−9 g mL−1. The relative standard deviation was 1.9% for 11 repeated determinations of 1.0×10−6 g mL−1 DCD. The proposed method was successfully applied to the analyses of DCD in tap water and milk products. And the recoveries were in the range of 87.0–102.3% with relative standard deviation values of 1.2–2.9%. Moreover, the minimum sampling rate was 120 samples h−1. The possible mechanism of the CL reaction was also discussed.
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A new chemiluminescence method for determination of dicyandiamide based on the N-bromosuccinimide–Merbromin–cetyltrimethylammonium bromide system
Journal of Luminescence, 2014Co-Authors: Hua Yu, Yuhai Tang, Guangbin Zhang, Zhongcheng WangAbstract:Abstract A novel and highly sensitive chemiluminescence (CL) method for the determination of dicyandiamide (DCD) has been developed based on the new CL system of N-bromosuccinimide–Merbromin–cetyltrimethylammonium bromide in alkaline solution. Experiment conditions were optimized using central composite design-response surface methodology. Under the optimal conditions, the relative CL intensity was linear with the concentration of DCD ranging from 5.0×10−8 g mL−1 to 3.0×10−6 g mL−1. The detection limit, at the signal-to-noise ratio of 3, was 3.0×10−9 g mL−1. The relative standard deviation was 1.9% for 11 repeated determinations of 1.0×10−6 g mL−1 DCD. The proposed method was successfully applied to the analyses of DCD in tap water and milk products. And the recoveries were in the range of 87.0–102.3% with relative standard deviation values of 1.2–2.9%. Moreover, the minimum sampling rate was 120 samples h−1. The possible mechanism of the CL reaction was also discussed.
Klaus Gollnick - One of the best experts on this subject based on the ideXlab platform.
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Merbromin mercurochrome and other xanthene dyes quantum yields of triplet sensitizer generation and singlet oxygen formation in alcoholic solutions
Journal of Photochemistry and Photobiology B-biology, 1992Co-Authors: Klaus Gollnick, Theodor Franken, Mohamed F R Fouda, Hanns R Paur, Stephan HeldAbstract:Abstract Absorption, fluorescence and phosphorescence maxima, singlet and triplet energies, and quantum yields of fluorescence φ F and intersystem crossing φ T of highly purified disodium salts of fluorescein dyes in alcoholic solutions are reported. The method of φ T determination by “external heavy atom enhanced photo-oxygenation” is described. Oxygen exerts no measurable effect on the short-lived excited singlet states but quenches the triplet states quantitatively in O 2 -saturated solutions, mainly by energy transfer yielding singlet oxygen, 1 O 2 ( 1 Δ g ). By increasing the number and atomic weight of halogen substituents in the fluorescein molecule, the quantum yields of triplet formation φ T and 1 O 2 generation φ Δ are enhanced, whereas the efficiency S Δ , with which interactions of the triplet excited dye with 3 O 2 yield singlet oxygen, seems to decrease. Within experimental error, φ F +φ T is equal to unity for the xanthene dianions. For the cationic sensitizer rhodamine B, however, this sum equals about 0.7, indicating that deactivation of the singlet excited state by internal conversion plays an appreciable role. Merbromin, a HgOH-substituted dibromofluorescein used world-wide as an inexpensive antiseptic (mercuchrome TM , mercurochrome TM ), shows quantum yields of 0.16±0.04 for triplet formation and 0.14±0.02 for 1 O 2 generation in alcoholic solution. Why mercury does not exhibit the expected internal heavy atom effect on the intersystem crossing process, remains to be elucidated.
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Merbromin mercurochrome a photosensitizer for singlet oxygen reactions
Journal of Photochemistry and Photobiology B-biology, 1990Co-Authors: Klaus Gollnick, Stephan HeldAbstract:Abstract Merbromin, produced in many countries and used world wide as an antiseptic under the trademark “mercurochrome”, is shown to be an efficient sensitizer for type II (singlet oxygen) photo-oxygenations by using 2-methyl-2-butene, (+)-limonene, (+)-α-pinene, α,α′-dimethylstilbenes and (—)- l -methionine as oxygen acceptors. Type I photo-oxygenations are negligible. An estimate of the quantum yield of singlet oxygen formation by Merbromin in methanol gives a value of about 0.1.
Hua Yu - One of the best experts on this subject based on the ideXlab platform.
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a new chemiluminescence method for determination of dicyandiamide based on the n bromosuccinimide Merbromin cetyltrimethylammonium bromide system
Journal of Luminescence, 2015Co-Authors: Hua Yu, Yuhai Tang, Guangbin Zhang, Zhongcheng WangAbstract:Abstract A novel and highly sensitive chemiluminescence (CL) method for the determination of dicyandiamide (DCD) has been developed based on the new CL system of N-bromosuccinimide–Merbromin–cetyltrimethylammonium bromide in alkaline solution. Experiment conditions were optimized using central composite design-response surface methodology. Under the optimal conditions, the relative CL intensity was linear with the concentration of DCD ranging from 5.0×10−8 g mL−1 to 3.0×10−6 g mL−1. The detection limit, at the signal-to-noise ratio of 3, was 3.0×10−9 g mL−1. The relative standard deviation was 1.9% for 11 repeated determinations of 1.0×10−6 g mL−1 DCD. The proposed method was successfully applied to the analyses of DCD in tap water and milk products. And the recoveries were in the range of 87.0–102.3% with relative standard deviation values of 1.2–2.9%. Moreover, the minimum sampling rate was 120 samples h−1. The possible mechanism of the CL reaction was also discussed.
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A new chemiluminescence method for determination of dicyandiamide based on the N-bromosuccinimide–Merbromin–cetyltrimethylammonium bromide system
Journal of Luminescence, 2014Co-Authors: Hua Yu, Yuhai Tang, Guangbin Zhang, Zhongcheng WangAbstract:Abstract A novel and highly sensitive chemiluminescence (CL) method for the determination of dicyandiamide (DCD) has been developed based on the new CL system of N-bromosuccinimide–Merbromin–cetyltrimethylammonium bromide in alkaline solution. Experiment conditions were optimized using central composite design-response surface methodology. Under the optimal conditions, the relative CL intensity was linear with the concentration of DCD ranging from 5.0×10−8 g mL−1 to 3.0×10−6 g mL−1. The detection limit, at the signal-to-noise ratio of 3, was 3.0×10−9 g mL−1. The relative standard deviation was 1.9% for 11 repeated determinations of 1.0×10−6 g mL−1 DCD. The proposed method was successfully applied to the analyses of DCD in tap water and milk products. And the recoveries were in the range of 87.0–102.3% with relative standard deviation values of 1.2–2.9%. Moreover, the minimum sampling rate was 120 samples h−1. The possible mechanism of the CL reaction was also discussed.
Lachmandath Tewarie - One of the best experts on this subject based on the ideXlab platform.
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Special Treatment and Wound Care of the Driveline Exit Site after Left Ventricular Assist Device Implantation.
The Thoracic and cardiovascular surgeon, 2015Co-Authors: Ares K Menon, Sophie-k Baranski, Jan Unterkofler, Rüdiger Autschbach, Ajay K Moza, Andreas Goetzenich, Lachmandath TewarieAbstract:Despite good results following implantation of left ventricular assist devices (LVADs), infections of the driveline and device pocket remain a major problem for patients on long-term support. We present the data from heart failure patients treated with a Thoratec HeartMate-II LVAD (Thoratec Corporation, Pleasanton, California, United States). From January 2008 to April 2011, in our institution, 40 heart failure patients (NYHA IV) were supported with a HeartMate-II LVAD. The driveline maintenance of 17 patients consisted of the use of Octenidine for the wound dressing, whereas Merbromin was additionally used for local irrigation in 31 patients. The data concerning driveline infections were analyzed retrospectively. In our study, 95% of the entire cohort was free from infections of the system. Two patients in the conventional group (11.8%) developed a driveline infection at a mean of 130.5 days during 3,416 patient-days (0.21 infection/patient-years). In the Merbromid group (Co. New FaDem SRL Farmaceutici & Chimici, Giugliano, Campania, Italy), all patients were free from any driveline infections during the observation period. In a log-rank comparison, the difference reached statistical significance (p = 0.043). During our observation period, fewer infections were noted with Merbromin treatment. A multicenter setting in a larger cohort should be performed to confirm these findings, although a (double-) blinded setting might be difficult to achieve. Georg Thieme Verlag KG Stuttgart · New York.
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Special Treatment and Wound Care of the Driveline Exit Site after Left Ventricular Assist Device Implantation.
Thoracic and Cardiovascular Surgeon, 2015Co-Authors: Ares K Menon, Sophie-k Baranski, Jan Unterkofler, Rüdiger Autschbach, Ajay K Moza, Andreas Goetzenich, Lachmandath TewarieAbstract:Objective Despite good results following implantation of left ventricular assist devices (LVADs), infections of the driveline and device pocket remain a major problem for patients on long-term support. We present the data from heart failure patients treated with a Thoratec HeartMate-II LVAD (Thoratec Corporation, Pleasanton, California, United States). Methods From January 2008 to April 2011, in our institution, 40 heart failure patients (NYHA IV) were supported with a HeartMate-II LVAD. The driveline maintenance of 17 patients consisted of the use of Octenidine for the wound dressing, whereas Merbromin was additionally used for local irrigation in 31 patients. The data concerning driveline infections were analyzed retrospectively. Results In our study, 95% of the entire cohort was free from infections of the system. Two patients in the conventional group (11.8%) developed a driveline infection at a mean of 130.5 days during 3,416 patient-days (0.21 infection/patient-years). In the Merbromid group (Co. New FaDem SRL Farmaceutici & Chimici, Giugliano, Campania, Italy), all patients were free from any driveline infections during the observation period. In a log-rank comparison, the difference reached statistical significance (p = 0.043). Conclusion During our observation period, fewer infections were noted with Merbromin treatment. A multicenter setting in a larger cohort should be performed to confirm these findings, although a (double-) blinded setting might be difficult to achieve.